JPH11139819A - High strength lightweight silica aerogel molded body and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lightweight molded body excellent in water resistance and heat insulating property by pouring a specified water glass soln. compsn. into a mold, allowing it to stand to form wet gel, releasing the gel from the mold and drying it by dehydration at a specified temp. SOLUTION: A water glass soln. compsn. having a heterogeneous phase structure consisting of sea and island phases is prepd. using alkali water glass, a water-soluble org. polymer which is compatible with water and/or is microscopically dispersed and stabilized in water in any ratio, e.g. a water-soluble polyether polyol, a water glass hardener, e.g. glyoxal and water so that >=60 wt.% of the entire alkali water glass is distributed in the sea phase. The compsn. is poured into a releasable molding vessel and allowed to stand at 5 to <80 deg.C to form wet gel. This gel is released from the vessel and dried by dehydration at <100 deg.C and/or freed of the org. material by firing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength lightweight silica airgel molded article derived from a water glass solution composition containing alkaline water glass as a main component and a method for producing the same. More specifically, a water glass solution composition comprising a quaternary system of alkali water glass, a water glass hardener, a water-soluble organic polymer exhibiting a property of being compatible with and / or stabilizing micro-dispersion in any proportion to water, and water. A water-glass solution composition having a heterogeneous phase structure composed of a sea phase and an island phase
Pour into a mold by one of the following methods: shot, 1.5 shot, or 2 shots, gel and solidify in the range of 5 ° C to less than 80 ° C to form a wet gel, and cure for a certain period of time if necessary. After curing, take out the wet gel,
The present invention relates to a so-called high-strength lightweight silica aerogel molded body characterized by obtaining a high-strength lightweight silica aerogel by dehydrating and drying and / or removing organic substances by baking at a temperature of less than 1000 ° C. and a method for producing the same.

[0002] Here, the high-strength lightweight silica airgel molded body refers to a porous silica airgel molded body that is hardly compressed and deformed and contains closed cells having a bulk density of 0.8 or less at the highest.

[0003] The one-shot method is a method in which a main agent and a curing agent are adjusted and mixed together in advance to form one liquid, and the one liquid is discharged. A method in which the two liquids are separately adjusted, and the two liquids are fed separately from each other, and at the same time, they are mixed by collision near the inlet of the discharge pipe to obtain the mixed liquid and discharge / outflow to a predetermined place. Further, in the two-shot method, the main agent and the curing agent are separately adjusted, and the two liquids are separately supplied in a form that secures a double pipe or a flow path in which two bundles are bundled. Means a method of mixing by collision in a part or a molding container.

[0004]

2. Description of the Related Art In general, an inorganic foamed cured product (also referred to as an inorganic lightweight cured product) is considered to be lightweight and excellent in fire resistance and heat insulation, and is widely used as a construction material. Representative of these known inorganic foam hardened bodies include hydraulic fine particles such as cement, granulated slag, hemihydrate gypsum, quicklime, slaked lime and the like. An inorganic foamed cured product is obtained by preparing a suspension slurry solution containing bubbles and pouring it into a mold as it is to be hydrated and cured, but the cured product for satisfying practical mechanical strength is obtained. The current state of apparent density is about 0.7 to 1.2 g / cm ³ , judging from materials for building materials on the market, which is not necessarily a sufficiently light material. In other words, although the inorganic foamed cured product inherently has properties such as heat resistance, nonflammability, and fire resistance that cannot be obtained from a plastic foamed cured product, as described above, there is still a problem that further weight reduction is strongly desired. doing.

[0005] In addition, known techniques already proposed for the purpose of ultimately reducing the weight of inorganic materials include, for example, N31 in 1931.
atuer, vol. According to the description on pages 127, 741, Kistler, S.M. There is an example in which silica aerogel was first successfully produced by drying a silica wet gel solvent-replaced by S in a supercritical state in an autoclave. In 1968, B
ull. Soc. Chem. Fr. On page 1906 of Nicholson et al. And Teichner et al., A proposal example of a method for producing wet silica gel can be found. I have. According to the aerogel production technology example and the like, it is said that an ultralight silica cured product having a porosity of approximately 85% to 98% can be produced. That is, if a well-known aerogel production technique using an alkyl orthosilicate compound as a starting material is used, it is possible to easily produce an ultralight porous inorganic cured product having an apparent density of 0.01 to 0.3 g / cm ^3. You can see what you can do. However, the ultra-lightweight porous cured product produced by the known aerogel production technique is generally expensive and has a uniaxial compressive strength of 0.5 kg.
It is widely known that the material is a very brittle material less than f / cm ² , and therefore has a problem that it is completely unsuitable as a material requiring high strength, for example, for a noncombustible board material for building materials. Particularly, in the production of a known silica airgel by a sol-gel method using an alkyl orthosilicate as a main raw material, there is a problem that a large amount of an organic solvent is indispensable.

On the other hand, it has long been known that an organic-inorganic composite plastic material can be produced from water glass and a diisocyanate compound. For example, Japanese Patent Publication No. 50-78700, Japanese Patent Publication No. 50-78700
Nos. 87191, 50-87193, 50
Representative technical disclosures can be found in JP-A-67194, JP-A-51-105393, JP-A-51-119095, and JP-A-55-65212. The organic-inorganic composite cured products obtained by those known techniques are said to be able to easily form foams and the like which are excellent in elasticity and heating dimensional stability at the same time as having high flame resistance, but the reason is unknown, but specifically I don't know of any examples that were put to practical use in Japan as construction materials.

In recent years, the above-mentioned organic-inorganic composite composition comprising water glass and various isocyanate compounds has been widely used as a rock-solid cracking filler (also referred to simply as a rock-solidifying agent). Examples of the publicly disclosed technology relating to a rock consolidation agent comprising the composition group include, for example, Japanese Patent Application Laid-Open Nos. 4-283290 and 4-283290.
No. 309616, No. 5-78667, No. 5-
No. 79278, No. 5-320645, No. 6
No. 207174 is a typical example.

Here, the water glass is generally represented by sodium alkali silicate or potassium alkali silicate.
It is widely known that although it is available at low cost and is a highly alkaline substance, it is highly safe for the human body. It is said that water glass becomes a silicate polymer as soon as it mixes with a water glass hardener such as an acid to form a silicate colloid hydrate and basically gives a nonflammable inorganic polymer gel. Water glass is thus one of the important raw material products for industrial use.

[0009] Next, there is a report that studies the production of an inorganic foam using the water glass as a main material. As an example of a water glass foam production report, for example, an article of “Technological development trend of ceramic foam attracting attention as a new industrial material” described in the Chemical Industry Time Report (No. 1785) issued on May 25, 1982. As is evident from the above, a method is known in which a concentrated aqueous solution of water glass is solidified into a foam by vigorously boiling or evaporating the water in a kettle or in a high-frequency oven or the like. The foam density is 0.08 ~
It is said that a product having a maximum usable temperature of 0.24 g / cm ³ and a maximum usable temperature of 870 ° C. can be obtained, but it has no water resistance and has a problem of dissolving or disintegrating in water.

Looking at the above, there is no concrete example of practical use of a lightweight and high-strength silica aerogel derived from sol-gel technology from inexpensive water glass as a material for construction materials.

[0011]

SUMMARY OF THE INVENTION The emergence of a high-strength silica airgel molded article, which has never before been light and has excellent water resistance, heat insulation properties, heat-resistant dimensional stability, etc., has been particularly strongly desired in the field of construction materials. In view of the above, it is an object of the present invention to provide a high-strength, lightweight silica airgel molded body that meets the needs of the market, using alkaline water glass that can be obtained at low cost in the market as a starting material, and a manufacturing technique therefor. More specifically, it is an object of the present invention to provide a high-strength lightweight silica aerogel molded article having a high apparent density of 0.8 g / cm ^{3 at} the highest and a uniaxial compressive strength characteristic of 3 kg / cm ² at the lowest, and a method for producing the same. .

[0012]

Means for Solving the Problems As a means for solving the above-mentioned problems, as a result of intensive studies, an aqueous solution containing an alkaline water glass and an aqueous solution containing a water-soluble organic polymer were phased in the presence of a water glass curing agent. The so-called water-soluble organic polymer phase, which is stabilized in a separated state, is gelled and molded into a heterogeneous solution composition having an island phase and an alkaline water glass liquid phase as a sea phase. The present inventors have found that the object can be achieved by drying and / or baking the gel at a temperature of less than 1000 ° C., thereby achieving the present invention.

That is, the method for producing a high-strength lightweight silica airgel molded article of the present invention comprises the steps of:
A water glass solution composition of the following (A) is poured thereinto, 5 ° C to 8
A high-strength lightweight silica aerogel molded article characterized by being formed into a gel by standing at a temperature of less than 0 ° C. and dehydrating and drying the demolded wet gel at a temperature of less than 1000 ° C. and / or baking off organic substances. It is a manufacturing method of. (B) alkaline water glass as a water glass solution composition,
It contains a water-soluble organic polymer exhibiting compatibility and / or micro-dispersion stabilizing properties in any proportion to water, a water glass hardener, and water, and the solution is composed of a sea phase-island phase. A heterogeneous solution composition having a homogeneous phase structure and at least 60% by weight or more of the total alkali water glass component blended in the solution being distributed to the sea phase.

Preferably, the water glass solution composition (a) is of a two-part type consisting of a base liquid A which is an aqueous solution containing alkaline water glass and a hardener liquid B which is an aqueous solution containing a water glass hardener. The reactive organic polymer is contained in one or both of the liquids in advance, and the base liquid A and the curing liquid B are mixed in a volume mixing ratio represented by the main liquid A: curing liquid B. The method for producing a high-strength, lightweight silica airgel molded article described above, characterized by being mixed in the range of 10: 100 to 100: 10.

The high-strength lightweight silica airgel molded article of the present invention is obtained by the above-mentioned production method and has a thickness of 1 to 200 μm.
This is a high-strength lightweight silica airgel molded body characterized by having a honeycomb-like microstructure containing a large number of closed cells. More preferably, the above-mentioned high-strength lightweight silica airgel molded body having a structure containing closed cells formed of 10 to 18 polyhedrons having rounded corners is provided. Still more preferably, the high-strength lightweight silica aerogel molded article described above, wherein the thickness of the cured film forming the continuous phase is in the range of 0.1 to 5 μm.
The most preferred high-strength lightweight silica airgel molded article of the present invention has an apparent density of 0.1 to 0.5 g / cm ^3.
Is most preferably within the range. The characteristic value relating to the morphology of the high-strength lightweight silica airgel molded body may be obtained by a known analysis method or observation method, and there is no particular limitation. The cross section or the cut cross section may be enlarged and observed with any of an optical microscope, an electron microscope, and a microscope, and may be expressed as a result. There is no restriction on the phase structure or its primary structure in the description.

That is, the present invention provides the following (1) to (2)
8).

(1) A water glass solution composition of the following (A) is poured into a mold container which can be separated from the mold.
Gelled at a temperature less than, the demolded wet gel,
A method for producing a high-strength lightweight silica airgel molded body, comprising dehydration drying and / or baking off organic matter at a temperature of less than 1,000 ° C. (B) alkaline water glass as a water glass solution composition,
It contains a water-soluble organic polymer exhibiting compatibility and / or micro-dispersion stabilizing properties in any proportion to water, a water glass hardener, and water, and the solution is composed of a sea phase-island phase. A heterogeneous solution composition having a homogeneous phase structure and at least 60% by weight or more of the total alkali water glass component blended in the solution being distributed to the sea phase.

(2) (a) The water glass solution composition is of a two-part type consisting of a base liquid A which is an aqueous solution containing alkaline water glass and a hardener liquid B which is an aqueous solution containing a water glass hardener. The polymer is preliminarily contained in one or both of the liquids, and the main liquid A and the hardening liquid B are mixed in a volume mixing ratio represented by the main liquid A: curing liquid B (10 : 100) to (100: 10). A method for producing a high-strength lightweight silica airgel molded article according to (1), characterized by being mixed in the range of (100) to (100: 10).

(3) The high-strength lightweight silica aerogel according to (1) or (2), wherein the whole amount of the water-soluble organic polymer is previously blended with the curing agent liquid B containing a water glass curing agent. Manufacturing method of molded body. (4) The alkali water glass is sodium silicate and / or potassium silicate in a molar ratio represented by SiO ₂ / Na ₂ O and / or SiO ₂ / K ₂ O in the range of 1 to 4.5. The method for producing a high-strength lightweight silica airgel molded article according to any one of (1) to (3). (5) The method for producing a high-strength lightweight silica airgel molded article according to (4), wherein the alkali water glass is a sodium silicate solution according to Japanese Industrial Standards / JIS-3.

(6) An aqueous organic polymer exhibiting the property of being compatible with water and / or stabilizing micro-dispersion at any ratio to water is one selected from the following (a) to (h) and / or
Or (1) to (5) characterized by comprising two or more types
The method for producing a high-strength lightweight silica airgel molded article according to any one of the above. (A) water-soluble polyether polyol (b) water-soluble polyvinyl alcohol (c) water-soluble starch (d) water-soluble cellulose derivative (e) water-soluble polyalkylene oxide (f) water-soluble acryl (g) water-soluble polyepoxide ( h) Water-soluble urethane

(7) A compound of the formula I wherein a water-soluble organic polymer exhibiting a property of being compatible with and / or stabilizing micro-dispersion at any ratio to water is siloxane-crosslinked by hydrolysis.

Formula I; -Si (R ¹ ) _n- (X) _3-n (where R ¹ is one selected from the group consisting of a hydrogen atom, a chlorine atom, a methyl group, an ethyl group and a propyl group) , X is a member selected from the group consisting of an alkoxyl group, an oxime group and an acetoxyl group each having an integer of 1 to 5 carbon atoms, and n represents 0 to 1). One or more selected from the group consisting of acryl, urethane, polyether, polyether polyester and polyester, wherein at least 0.7 or more are introduced in one molecule on average and the main chain excluding the active silyl group is water-soluble. Two or more kinds, having a weight average molecular weight of 2,000 to 5
(1) The active silyl group-containing prepolymer in the range of 000 and / or one of active silanol group-containing prepolymers which are hydrolysis products thereof. The method for producing a high-strength lightweight silica airgel molded body according to the above.

(8) The water-soluble organic polymer having the property of being compatible with water and / or stabilizing micro-dispersion at any ratio is one or more of the above-mentioned (a) and (b) and / or
Used in combination with a so-called alkaline water glass and a non-reactive water-soluble organic polymer represented by at least one kind and the active silyl group-containing prepolymer. : Used in a range of (1: 100) to (100: 1) in a weight ratio represented by an active silyl group-containing prepolymer, wherein A method for producing a strong lightweight silica airgel molded article. (9) The water glass curing agent is at least one selected from the group consisting of a water-soluble organic acid, a water-soluble organic monomeric curing agent that releases a sustained-release acid in alkaline water, an inorganic curing agent, and CO _2, or It is characterized by using two or more types (1) to
(8) The method for producing a high-strength lightweight silica airgel molded article according to any of (8).

(10) A water-soluble organic monomeric curing agent which releases a sustained-release acid in alkaline water is a water-soluble alkylene carbonate, a water-soluble lactone, a water-soluble alkylene glycol diacetate compound and a water-soluble dibasic acid. (9) The method for producing a high-strength lightweight silica airgel molded article according to (9), wherein one or more selected from the group consisting of alkyl esters and the like are used. (11) The composition according to any one of (1) to (10), wherein the water glass solution composition of (1) further contains a polymer surfactant in a range of 0.001 to 5% by weight. The method for producing a high-strength lightweight silica airgel molded article according to the above. (12) When the water glass solution composition of (1) is gelled, organic fibers and / or inorganic fibers that can be more uniformly dispersed are combined in a proportion of 0.1 to 10% by weight in the gel. The method for producing a high-strength lightweight silica airgel molded article according to any one of (1) to (11), characterized in that:

(13) In the water glass solution composition of (1), which is of a two-pack type, the two liquids of the base resin and the curing agent are each approximately 1: 1 in a volume mixing ratio represented by the base liquid: the curing agent liquid. (1)-(1)
The method for producing a high-strength lightweight silica airgel molded article according to any one of 2). (14) The high-strength light weight according to any one of (2) to (13), wherein the alkaline water glass content in the main component liquid A is contained so as to be 5 to 50% by weight in terms of solid content. A method for producing a silica airgel molded body. (15) When mixed with the entire amount of the main solution A, the main solution A
A water glass hardener corresponding to 50 to 250 mol% of an alkali represented by Na ₂ O and / or K ₂ O therein;
An aqueous solution containing 2.5 to 50% by weight of a water-soluble organic polymer exhibiting the property of being compatible with and / or stabilizing micro-dispersion in water at any ratio in the curing agent liquid. The method for producing a high-strength lightweight silica airgel molded article according to any one of (2) to (14), which is used as the curing agent liquid B.

(16) In the water glass solution composition of (a), the main component liquid A comprises the following main component liquid E, and the curing agent liquid B comprises the following curing agent liquid F. (2)-
(15) The method for producing a high-strength lightweight silica airgel molded article according to any of (15). As the main agent liquid E, SiO ₂ / Na ₂
An aqueous solution in which the molar ratio of O is 2.5 to 3.5 and the solid content of alkali water glass is 15 to 40% by weight. When the curing agent liquid F is mixed with the entire amount of the main agent liquid E, the curing liquid E
A water-soluble organic monomeric curing agent that releases a sustained-release organic acid in alkaline water corresponding to 50 to 250 mol% of an alkali represented by Na ₂ O in the water; And / or 80 to 9 of ethylene oxide at a ratio of the amount of addition modification to glycerin being 100.
One kind of polyether diol and / or polyether triol having a weight average molecular weight of 2,000 to 30,000 obtained by random addition or block addition of 9% by weight and 20 to 1% by weight of propylene oxide. Or, an aqueous solution comprising 5 to 35% by weight of the content of two or more curing agents F in the liquid.

(17) The water glass curing agent may be glyoxal alone or in combination with one or more selected from the group consisting of carbonic acid, sulfuric acid and phosphoric acid and / or an alkali metal hydrogencarbonate or an alkali metal hydrogensulfate. And the total amount thereof is (Na) of the alkaline water glass in the system.
₂ O + K ₂ O), characterized in that it is contained in an amount corresponding to 70 to 200 mole% of the total alkali content expressed by (1)
The method for producing a high-strength lightweight silica airgel molded article according to any one of-(16). (18) Either or both of ethylene carbonate and propylene carbonate are used as the water glass curing agent, and the amount thereof is (Na ₂ O) of the alkali water glass in the system.
+ K ₂ O), characterized in that it is contained in an amount corresponding to 55 to 110 mole% of the total alkali content expressed by (1) -
(16) The method for producing a high-strength lightweight silica airgel molded article according to any of (16). (19) The use of γ-butyrolactone alone as a water glass hardener, and the total alkali content of (Na ₂ O + K ₂ O) 110 of the alkali water glass in the mixed system
The method for producing a high-strength, lightweight silica airgel molded article according to any one of (1) to (16), characterized by containing an amount corresponding to ２１０210 mol%. (20) One type of a water-soluble dicarboxylic acid alkyl ester compound in which an alkyl chain length portion is represented by an integer of 1 to 3 carbon atoms as a water glass curing agent, and a mixture of an alkali water glass in a mixed system ( High strength lightweight silica aerogel according to any one of (1) to (16), characterized by containing an amount corresponding to 55 to 110 mol% of the total alkali represented by (Na ₂ O + K ₂ O). Manufacturing method of molded body.

(21) The water glass solution composition (a) is poured into a steel or plastic releasable molding container and allowed to stand for gelation, and the resulting wet gel has a gel uniaxial compressive strength. At least at the time when it exceeds ² kg / cm ^{2, it} is removed from the mold, and further through any one or more of the following steps (α) to (δ), the apparent density of containing closed cells is 0.05 to It is characterized by producing a silica airgel molded body in a range of 0.8 g / cm ³ (1) to (1).
(20) The method for producing a high-strength lightweight silica airgel molded article according to any of (20). (Α) Dehydration drying process from room temperature to less than 180 ° C (β) Firing process in air or inert gas at less than 1000 ° C (γ) Cooling / cutting process (δ) Sealer / painting process

(22) High strength obtained by any one of the production methods described in (1) to (21), characterized by having a honeycomb-like microstructure including a large number of closed cells of 1 to 200 μm. Lightweight silica airgel molded body. (23) The high-strength lightweight silica aerogel molded article according to (22), wherein a structure is formed in which closed cells formed of 10 to 18 polyhedrons having rounded corners are incorporated. (24) The thickness of the cured film formed of the continuous phase is 0.3
The high-strength lightweight silica airgel molded article according to (22) or (23), which is in a range of from 5 μm to 5 μm. (25) The high-strength lightweight silica airgel molded article according to any of (22) to (24), wherein the apparent density is in the range of 0.1 to 0.5 g / cm ³ . (26) Any one of (22) to (24), characterized in that a sealer composition and / or a paint composition is applied to one surface, and one surface is cosmetically coated and has water-impermeable properties. High-strength lightweight silica airgel molded body.

(27) The sealer composition is at least one selected from the group consisting of a solution or emulsion composition containing a silicon or fluorine compound, an acrylic resin composition, a urethane composition and an epoxy resin composition. The high-strength lightweight silica airgel molded article according to (26), which is characterized in that: (28) The coating composition is characterized by being at least one selected from the group consisting of a solution or emulsion composition containing a silicon or fluorine compound, an acrylic resin composition, a urethane composition and an epoxy resin composition. (26) The high-strength lightweight silica airgel molded article according to (26).

Hereinafter, the present invention will be described in more detail.

The method for producing the high-strength lightweight silica aerogel molded article of the present invention (hereinafter, the high-strength lightweight silica aerogel molded article is simply referred to as silica aerogel) is described in more detail, for example, without limitation. In a releasable molding container represented by steel or reinforced plastic, etc., a one-liquid or two-liquid type (a) water glass solution composition shown below is subjected to a one-shot method, a 1.5-shot method or A special multiphase that mixes by any of the shot methods, gently pours in, and gels by standing at a temperature of 5 ° C to less than 80 ° C to exhibit at least 2 kgf / cm ² or more uniaxial compression characteristics. Demolding and manufacturing a wet gel with a structure
This is a production method characterized by obtaining a high-strength and light-weight molded body of silica airgel by a method of appropriately dehydrating and drying and / or baking off organic matter at a temperature of ° C. In addition, the water glass solution composition of the above (A) is compatible with (I) alkali water glass (in the following description, the alkali water glass may be represented by a symbol W) and (II) water at any ratio. A water-soluble organic polymer exhibiting dissolution and / or micro-dispersion stabilizing properties [hereinafter simply referred to as (II) a water-soluble organic polymer, and may be represented by a symbol 0]; (III) a water glass curing agent; IV) water, and the solution forms a heterogeneous phase structure composed of a sea phase and an island phase, and at the same time, at least 6% of the total alkali water glass component blended in the solution.
An O / W type heterogeneous composition in which 0% by weight or more is distributed to the sea phase. Preferably, at the same time, an O / W-type water glass solution composition in which at least 50% by weight or more of the total water-soluble organic polymer component blended in the solution is individually distributed to the island phase. .

In the water glass solution composition (a), from immediately after preparation to gelation, the solution composition forms an extremely thin cloudy system and is composed of at least two or more so-called sea-island phases. An important point is that it has a multiphase structure (hereinafter simply referred to as a sea-island structure). However, after the liquid composition immediately after its preparation once passes through a homogeneous and transparent liquid system, it is subjected to two or more complex operations as the curing reaction of the water glass proceeds or by gradually lowering the liquid temperature. It includes the case where a phase newly appears.

As a means for confirming that a sea-island structure composed of two or more phases is formed, a known phase structure observation method may be used, and there is no particular limitation. Preferably, the following method is used. It is represented by the result of determination. One of them is that a drop of the mixed solution is collected on the top of a transparent glass slide, and then quickly observed with a biological microscope or a phase contrast optical microscope to indicate the presence of two or more liquid phases. This is when an image is obtained. At that time, a method of observing with the naked eye, taking a still picture, or recording the light transmission image information on a video tape or an optical disk and displaying the image with a cathode ray tube at the same time may be appropriately adopted. As another discrimination method, after a certain amount is collected in a test tube, it does not immediately separate into two upper and lower layers in a still state, but it is not possible to separate the two layers at 100 to 50,000 revolutions per minute.
If two or more liquid layers inside the test tube are observed by centrifugation in a centrifuge for 0 seconds to several hours, it can be determined that the system has a sea-island structure.

Further, in the O / W type sea-island structure of the water glass solution composition or the wet gel of the above (A), particularly, the size (size of the island phase) and the shape of the droplet forming the island phase Is not particularly limited. Preferably, the island phase size is 0.0
1 μm to 1 mm, more preferably 0.1 μm to 5
00 μm range, more preferably 1 μm to 200 μm
It is better to be within the range of m. The preferable shape of the island phase is, for example, a polyhedron having rounded corners, a sphere, a football, an egg, a column, a disk, a donut, a prism, a dango, a thread, a grape bunch, and a drop. Examples include raindrop-like and amoeba-like shapes on the way. It is particularly preferable that they exist in a 10-18 polyhedral shape with rounded corners, in a spherical shape or in a football shape, or in a secondary aggregate thereof.

In the water glass solution composition (a) according to the present invention, when the total amount of the alkali water glass (I) contained in the system is 100, an amount corresponding to 60 to 100% by weight thereof is obtained. More preferably, it is important to provide an O / W type solution in which 80 to 100% equivalent is distributed to the sea phase. Preferably, all (I) contained in the system
I) When the water-soluble organic high molecular weight is 100,
100% by weight, more preferably 80 to 100%
Such a composition that satisfies the above-mentioned fact that a considerable amount is distributed to the island phase at the same time as above is mentioned as a more preferable one.

From the water glass solution composition (A) satisfying the above requirements, the uniaxial compressive strength characteristic is about 2 to 30.
A wet gel having a high strength of kgf / cm ² and high water resistance is produced, which is one of the features of the O / W type (a) water glass solution composition according to the present invention. Still further, silica aerogel derived by appropriately dehydrating and drying the wet gel under specified conditions and / or firing at a high temperature is very light and has a uniaxial compressive strength characteristic of about 3 to 50 kgf / cm.
^It can be made to have a very high strength of about ² and is one of the features of the wet gel.

In the reverse W / O-type (a) water glass solution composition, the wet gel often obtained is soft or paste-like, and it is difficult to form and remove it in a fixed shape. . Therefore, a silica airgel suitable for the purpose of the present invention cannot be produced from the W / O-type (a) water glass solution composition.

Incidentally, whether or not the (a) water glass solution composition containing the essential four components (I) to (IV) is an O / W type solution satisfying the above requirements Although there is no particular limitation on the method of determining in advance, it is preferable that the following method be used. One of the discrimination methods is a phase equilibrium diagram of a three-component system excluding a water glass hardener, that is, a three-component system of (I) alkali water glass- (II) water-soluble organic polymer- (IV) water. Is determined in advance, and the (I) distribution ratio of the alkali water glass to the sea phase is roughly estimated from the phase equilibrium diagram. From the phase equilibrium diagram composed of the three components, it is generally known that a composition region in which a sea phase formed by partitioning and containing alkali water glass at a high rate is stably formed, a composition region in which only a homogeneous system is formed, and the like. I can do it. In preparing a phase equilibrium diagram consisting of a three-component system of (I) alkali water glass- (II) water-soluble organic polymer- (IV) water, the composition is changed and the three-component heterogeneous solution is prepared. Several kinds of the system composition are adjusted at a constant temperature, and the composition is forcibly centrifuged, and the upper and lower layers are separately collected and weighed. From the measurement results of the volume or weight of the upper and lower layers collected separately, the distribution volume ratio or distribution weight ratio of each of the sea phase and the island phase is determined.
Further, it is easy to obtain the (I) alkali water glass concentration, (II) water-soluble organic polymer concentration and (IV) water concentration in each phase (in the layer) by using each sample of the upper layer and the lower layer collected. Can draw.

In general, as the analysis method for determining the alkali water glass concentration of (I), for example, JIS-K-1408
The method according to is good. JIS-K-1408 is a neutralization titration analysis method using a hydrochloric acid solution of a known concentration using so-called methyl orange as an indicator, and (Na ₂ O + K
_It is determined as the content concentration represented by ₂ O). Also JI
SK-1408 also discloses a method for analyzing SiO ₂ , and the measured values of both reveal the alkali water glass concentration in the system (in each separated solution layer). In general, when a commercially available alkaline water glass solution is purchased and used, the molar ratio of SiO ₂ / Na ₂ O, SiO ₂
/ K ₂ O molar ratio, SiO ₂ concentration, Na ₂ O concentration, K ₂ O concentration, etc. have been clarified. For example, the concentration of SiO ₂ , Na ₂ O or K ₂ O in each collected layer
Any one of the concentrations is obtained, and the alkali water glass content (silicate concentration) can be easily calculated based on the obtained value. If the total content of alkaline water glass in the liquid layer occupying the sea phase is determined, the following formula is used: distribution ratio of alkali water glass occupying the sea phase% = (total value of alkali water glass content in sea phase / grout agent) Amount of alkaline water glass blended in composition) × 10
0] is obtained.

In general, as the method for determining the concentration of the water-soluble organic polymer (II), a known quantitative method may be appropriately employed, such as an absorbance quantitative method, an organic carbon analysis conversion method, and a hydrophobic organic solvent extraction method. And the like. As a general method for determining (IV) water concentration, in the case of this system,
For example, the amount of inorganic solid and the amount of evaporated component (concentration) may be obtained by an evaporation to dry weight method, and the (II) water-soluble organic polymer concentration separately obtained may be subtracted from the evaporation loss value (concentration).

From the phase diagram obtained by the method described above, the distribution ratio of (I) the alkali water glass in the sea phase is 60% by weight or more, preferably 100% by weight, assuming that the total amount of the alkali water glass charged is 100. After knowing the three-component composition in the range of 80 to 100% by weight in advance, (III)
Particularly recommended is a method for preparing the (a) water glass solution composition according to the present invention by adding a necessary amount of a water glass hardener.

By the way, the following method is representative of an analysis method for directly determining (I) the distribution ratio of (I) the alkali water glass in the sea phase in the water glass solution composition. For example, in a solution system using a water-soluble organic mono-curing agent having a gel time of 3 minutes or more and having a property of gradually releasing an acid in alkaline water as a water glass curing agent, The composition is semi-forced in a short period of time and separated into two layers by a high-speed centrifugal separator. The incineration heating residue at 500 to 800 ° C. using the weighed sample was taken as [Si ₂ O + Na ₂
O + K ₂ O] content to that the distribution ratio of the total alkali water glass to an alkali water glass distribution phase medium directly know it is possible in.

For example, when the gel time is less than 3 minutes, or when the gel time is 3 minutes or more and (III) an inorganic curing agent is used as a water glass curing agent, Alternatively, the values in the phase equilibrium conceptual diagram of the three-component system may be used instead. Preferably, after obtaining a direct wet gel body composed of the composition, carbon, Si, N
From the elemental analysis pattern focusing on the essential constituent elements derived from the constituent requirements such as a and K, the component constituent ratio constituting each multiple phase may be a value obtained by a quantitative analysis for each phase. That is, if the value of the partition ratio of (I) the alkali water glass to the sea phase obtained by any of the above-described methods or other known compositional analysis and quantification methods falls within the above-described requirements, the description of the present invention is based on ( B) It is preferably included as a water glass solution composition.

Incidentally, in the hardening reaction of a known alkaline water glass solution which is generally used in a homogeneous system, the more the precipitation and aggregation of the formed silicate colloid, the more the occupied gel volume becomes the original solution volume. It is known to decrease much more, a phenomenon often observed with the naked eye in the production of syneresis water. The silicate colloid formed at that time is generally referred to as primary particles having a size of several to several tens of nanometers, and it is known that the primary particles aggregate and / or combine to give a fixed volume of hydrogel. .

The (a) water glass solution composition according to the present invention is extremely characterized in that the hardening behavior of the alkali water glass is mainly generated by being localized in the sea phase. For this reason, the phase structure change accompanying the progress of the curing reaction of the alkali water glass exhibits a curing behavior that proceeds while reducing the occupied volume of the sea phase. Further, a phase structure change in which the island phase expands to increase the occupied volume is observed. Due to such a change in phase structure, (a) of the present invention is described.
The wet gel produced from the water glass solution composition has an apparent honeycomb-like micro O / W type structure. Further, by drying and / or sintering the multi-phase hydrogel, it is possible to produce a lightweight, high-strength, water-resistant silica airgel intended for the present invention.

Incidentally, (a) the water glass solution composition is a one-pack, two-pack or three-pack mixed composition composed of the above-mentioned components (I) to (IV) as essential components. There is no particular limitation. Particularly, a two-pack type is preferable. When the two-pack type is used, for example, (I) and (IV)
Or a liquid containing (I), (II) and (IV), or a liquid containing (I), (II), (IV) and 30
Within minutes, the liquid containing (III) can be handled as the base liquid, respectively, as long as no gel is formed. On the other hand, as the curing agent liquid, for example, (III) and (I
V) or (II), (III) and (I)
V), or even (II) and (III)
The liquid containing (I) can be handled as a curing agent liquid within the range that does not show any gel at all within (30 minutes), (IV) and (IV). Generally, if the gel time is 30 minutes or more, 1
It can be handled as a liquid-type (a) water glass solution composition, in which case it may be handled in a one-shot manner,
It is preferable that all the liquids be supplied and discharged in one shot into the prepared molding container within a time period during which no gelation occurs. In the two-part type (a) water glass solution composition, the base liquid and the curing agent liquid are handled by either the 1.5 shot method or the two shot method, and are fed into a predetermined molding container and mixed and discharged. Is preferably performed.

(A) In the water glass solution composition,
Preferably, an aqueous solution composed of (I) alkali water glass and (IV) water is used as the main component liquid A, while the following water-soluble organic polymer (II), the following water glass hardener (III) and (I)
V) A hardener liquid B consisting of water and two liquids are prepared in advance,
When necessary, the two liquids are mixed in a mixing volume ratio represented by the main agent: the curing agent in the range of (10: 100) to (100: 10),
More preferably, a water glass solution composition (a) obtained by mixing as close as possible to 1: 1 is preferred. The reason is that any gel time and wet gel strength can be easily adjusted arbitrarily according to the mixing ratio of the main agent liquid A and the curing agent liquid B. One of the reasons is that the storage stability of each of the two liquids is excellent.

Next, (A) alkaline water glass, which is one of the essential components for constituting the water glass solution composition, will be described in detail. The alkali water glass (I) according to the present invention is specifically water-soluble and amorphous sodium silicate and / or potassium silicate, and any known materials can be used without any problem. no but specific examples include sodium silicate and / or potassium silicate represented by SiO ₂ / Na ₂ O and / or 1-50 in a molar ratio represented by SiO ₂ / K ₂ O and the like, for example. Still more preferably, those having a molar ratio of SiO ₂ / Na ₂ O and / or SiO ₂ / K ₂ O of 1 to 4.5 can be mentioned.

In the particularly recommended two-part water type (a) water glass solution composition according to the present invention, a solution comprising (I) alkali water glass and (IV) water is used as the main part liquid A. Things are good. The concentration of the alkaline water glass in the main component liquid A is limited to the maximum viscosity that can be sent in an aqueous solution state, and is not particularly limited. It is preferably in the range of 10 to 35% by weight, most economically 10 to 25% by weight. At 5% by weight or less, 3 kgf / cm in uniaxial compressive strength
It should be noted that it may not be possible to induce ^two or more silica airgels with good reproducibility.

Here, the molar ratio of SiO ₂ / Na ₂ O is 1 to
As the sodium silicate-based water glass represented by 4.5, for example, in addition to sodium orthosilicate, Japanese Industrial Standards / JIS K-
No. 1 to No. 4 sodium silicate specified in 1408. In particular, No. 3 sodium silicate is a very preferable example because it is most easily available on the market.

JIS No. 3 sodium silicate has a SiO ₂ content of 28 to 30% by weight and a Na ₂ O content of 9 to 10% by weight.
The molar ratio of SiO ₂ / Na ₂ O calculated from the specified value is 2.8 to 3.33.

Potassium silicate having a SiO ₂ / K ₂ O molar ratio of 1 to 5 is the same as the sodium silicate described above.

Further, SiO ₂ / Na ₂ O and / or Si
Alkaline water glass having a molar ratio of O ₂ / K ₂ O of 5 to 50 is prepared by subjecting the above-mentioned JIS-compatible water glass to a known treatment method, for example, deionization with an ion exchange resin and simultaneously appropriately proceeding a polysilicic acid reaction. Listed weak alkaline colloidal water glass solutions and the like. When a substance having a molar ratio of SiO ₂ / Na ₂ O and / or SiO ₂ / K ₂ O of 1 or less is selected and used, it is necessary to (I) neutralize or coagulate the alkali component of the alkali water glass ( III) The water glass hardener must be used in high concentration and in a large amount, which tends to be economically disadvantageous.

In the above (I) alkaline water glass, Si is used.
When an alkali water glass having a molar ratio of O ₂ / Na ₂ O and / or SiO ₂ / K ₂ O of 50 or more is selected and used, the resulting (a) water glass solution composition tends to be expensive. It is uneconomical.

Next, the water-soluble organic polymer (II), which is one of the essential components for constituting the water glass solution composition of the present invention, will be described in detail. The (II) water-soluble organic polymer has the property of being compatible with and / or stabilizing microdispersion in water at any ratio,
The aqueous solution containing the aqueous solution may be any as long as it has the property of forming a heterogeneous phase without being incompatible when mixed with the alkaline water glass solution. New water-soluble organic polymer substances may be appropriately selected and used without any particular limitation.

Preferably, the (II) water-soluble organic polymer includes, for example, (a) a water-soluble polyether polyol, (b) a water-soluble polyvinyl alcohol, (c) a water-soluble starch, (d) a water-soluble cellulose derivative, (E) a water-soluble polyalkylene oxide, (f) a water-soluble acrylic,
(G) water-soluble polyepoxide, (h) water-soluble urethane polyvinyl alcohol, (i) water-soluble polyvinylpyrrolidone, (j) water-soluble acrylamide, (k) water-soluble poly-N-vinylacetamide, (l) water-soluble amino One type or a mixture of two or more types selected from resins and the like is typical. (A) to (l) are water-soluble organic polymers which are non-reactive with alkali water glass.

The water-soluble polyether polyol (a) may be a known one, and is not particularly limited. Generally referred to as a water-soluble polyalkylene glycol or a water-soluble polyol. Any compatible polyol is preferably included, and preferably a polyether diol or a polyether triol. (B) The water-soluble polyvinyl alcohol may be a known one, and there is no particular limitation. Micro-dispersion should be stable. (C) The water-soluble starch may be a known one, and is not particularly limited, and may be a cationized starch or an oxidized starch. (D) The water-soluble cellulose derivative may be a known one, and is not particularly limited, and may be, for example, methylcellulose, carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose and the like. (E) The water-soluble polyalkylene oxide may be a known one, and is not particularly limited, and is represented by, for example, polyethylene oxide.

(F) Water-soluble polyacrylic Any known one may be used without particular limitation, for example, water-soluble polyhydroxyacrylate, water-soluble polyhydroxymethacrylate, hydroxyacrylate and / or hydroxymethacrylate and acrylic acid and / or methacrylic. It is represented by a water-soluble terpolymer such as an acid or a water-soluble terpolymer with other copolymerizable acrylates. (G) The water-soluble polyepoxide may be a known one, and is not particularly limited, and is represented by the polyvalent epoxide compound including the above-described polyalkylene glycol monoepoxide. (H) The water-soluble polyurethane may be a known one, and is not particularly limited, and a typical example is a water-soluble resin derived from the above-described polyalkylene glycol and diisocyanate compound, or an emulsified resin solution thereof. . (I) The water-soluble polyvinylpyrrolidone may be a known one, and is not particularly limited, and is represented by, for example, a high molecular weight N-vinylpyrrolidone or a water-soluble binary copolymer resin thereof.

(J) The water-soluble acrylamide may be a known one, and is not particularly limited. Examples thereof include acrylamide, methacrylamide, N-dimethylacrylamide,
(Meth) represented by N-dimethylmethacrylamide, etc.
Acrylamide monomer homopolymers and copolymers,
Alternatively, a water-soluble copolymer of the monomer and a copolymerizable vinyl compound is typical. (K) The water-soluble poly-N-vinylacetamide may be a known one, and is not particularly limited, and a homopolymer or a water-soluble copolymer using an N-vinylacetamide monomer is typical.

(L) The water-soluble amino resin may be a known one, and is not particularly limited, and is a water-soluble or self-emulsifying polyamine resin (water-soluble polyalkylene ether monoamine) used as a room temperature curing agent for an epoxy resin. ,
It is meant to include water-soluble polyalkylene ether diamine, water-soluble polyalkylene ether triamine and the like. )
Alternatively, for example, urea-formalin resin, urea-melamine-formalin resin, or the like may be used.

As the particularly preferred (II) water glass organic polymer, one or a mixture of two or more selected from the above (a) to (h) is preferable. Still more preferably, the average weight average molecular weight is in the range of 2,000 to 50,000, and is selected from (a) a water-soluble polyether polyol, (e) a water-soluble polyalkylene oxide, and (h) a water-soluble urethane. In addition, it is preferable to use one or a mixture of two or more.

In addition to the above, specific examples of the (II) water-glass organic polymer of the present invention which can be used include:
Formula I exhibiting siloxane crosslinkability by hydrolysis

Formula I; -Si (R ¹ ) _n- (X) _{3 -n} (where R ¹ is ^one selected from a hydrogen atom, a chlorine atom, a methyl group, an ethyl group, and a propyl group, and X is Carbon number is 1
N is a kind selected from an alkoxyl group, an oxime group, and an acetoxyl group represented by an integer of 5; The active silyl group terminal represented by the formula (1) is introduced in an average of at least 0.7 or more in one molecule, and the main chain excluding the active silyl group is water-soluble, from acrylic, urethane, polyether, polyether polyester, polyester. One or more selected compounds having a weight average molecular weight of 2,
Active silyl group-containing prepolymer (II-1) in the range of 000 to 50,000 and / or an active silanol group-containing prepolymer (II-
2) and the like are preferred.

The active silyl group-containing prepolymer (II-
1) may be obtained by a known method, and there is no restriction on the manufacturing method and the like. A typical known production method for a method for producing a polymer having an active silyl group at a molecular terminal is described in, for example,
For producing a silyl-modified composition having a polyether skeleton represented by JP-A-156599;
A method for producing a silyl-modified composition having a polyester skeleton represented by No. 9695 is well known. The active silyl group-containing prepolymer according to the present invention can be easily produced by a method according to the known method.

The active silyl group-containing prepolymer (II-
A more specific example of 1) will be described. For example, selected from glycerin, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, trimethylolpropane, pentaerythritol, and aliphatic and / or aromatic or alicyclic monoalcohols represented by an integer having 1 to 8 carbon atoms. The addition of 60 to 100% by weight of ethylene oxide and 40 to 0% by weight of propylene oxide and / or butylene oxide calculated on the basis of the total addition modification amount as 100 to the one kind of the active hydrogen group-containing low molecular weight compound. Polyalkylene glycol skeleton which is a modified derivative (hereinafter also referred to as polyether skeleton)
And / or a polyether prepolymer modified with a terminal silyl group represented by the above general formula I and / or a polyethylene glycol having a molecular weight of at least 1,000 or more and an aliphatic such as succinic acid, maleic acid, adipic acid and the like. A terminal silyl group-modified polyether polyester-based prepolymer represented by the above formula I, which forms a water-soluble polyether polyester skeleton derived from dibasic acid, and / or
For example, glycols having a weight average molecular weight of at most 1,000 such as ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol, and aliphatic dibasic acids such as succinic acid, maleic acid, and adipic acid. The above-mentioned general formula I which forms a so-called polyester skeleton obtained by esterifying a seed or two or more kinds
Water-soluble derived from a polyester prepolymer modified with a terminal silyl group or a polyethylene glycol having a weight average molecular weight of 400 to 3,000 and an aliphatic diisocyanate compound represented by hexamethylene diisocyanate or norbornane diisocyanate. Examples thereof include a terminal silyl group-modified polyurethane-based prepolymer represented by the general formula I, which forms a polyurethane polyol skeleton. It is particularly preferable to use either a water-soluble terminal silyl group-modified polyether-based prepolymer or polyurethane-based prepolymer from the viewpoint of economy.

In the active silyl group-containing prepolymer (II-1) according to the present invention, R ^{1 in the} above formula I is ^one selected from a methyl group, an ethyl group and a propyl group, and X is a group having 1 to 1 carbon atoms.
An average of at least 1.2 to 6 active silyl groups at one end of an active silyl group selected from an alkoxyl group and an acetoxyl group represented by an integer represented by 5 are introduced into one molecule, and the main chain excluding the active silyl group is water-soluble. It is more preferable to use an active silyl group-containing prepolymer having a weight average molecular weight in the range of 2,000 to 20,000. Most preferably, the terminal of the active silyl group is 1
Those having at least 2 to 3 molecules introduced into the molecule on average.

Next, an active silanol group-containing prepolymer (II-2) is represented by the following formula-III

Embedded image —Si (R ¹ ) _n — (Y) _3-n Formula III (where R ¹ is ^one selected from a chlorine atom, a hydrogen atom, a methyl group, an ethyl group, and a propyl group, and Y is -O ^over · H ^over group,
-O ^{chromatography} · Na ^over group, -O ^{chromatography} · K ^over group, one selected from -O ^over · Li ^{chromatography} radical, n represents each 0-1. ) Of the active silanol group at least 0.7 per molecule on average.
And the weight average molecular weight of the main chain organic polymer excluding the active silanol group-introduced portion is from 2,000 to 5
It is a composition comprising one or more kinds in the range of 0000, and there is no limitation on the production method and the like. Preferably a methyl group as R ^1, is either an ethyl group, also preferably -O ^over · H ^over groups and / or -O ^over the Y group
· Na ^over group.

An active silanol group-containing prepolymer (II)
In the method of obtaining -2) in advance, for example, the active silyl group-containing prepolymer (II-1) can be easily obtained by hydrolyzing it with water. In this case, it is particularly preferable to remove and purify the hydrolyzed free volatile components which are liberated to the outside of the system as appropriate.

As one type of the water-soluble organic polymer (II) according to the present invention, in particular, an active silanol group-containing prepolymer (I)
Advantages of using I-2) include the following. The active silyl group-containing prepolymer (II-1) which is basically incompatible with water cannot be used as a component (II) as it is, but the active silyl group-containing prepolymer which is basically incompatible with water When the compound (II-1) is hydrolyzed and modified into the above-mentioned formula-III, there is an advantage that the compound itself can be made compatible with water and / or microsuspended. That is, a precursor of an active silyl group-containing prepolymer (II-1) having a polymer skeleton of an incompatible organic polyol which is hardly soluble in water or immediately separates into two layers is formed as one component of (II). However, the active silanol group-containing prepolymer (II-2) produced by further hydrolyzing the precursor has an advantage that it can be effectively used as a preferable one of (II).

The active silanol group-containing prepolymer (II)
-2) is preferably a compound having preferably 2 to 6 active silanol group terminals in one molecule, particularly preferably 2 to 3
It is que. Its weight average molecular weight is 2,000-3.
It can be said that the range of 000 is more preferable. In order to stably handle the active silanol group-containing prepolymer (II-2) in a liquid state, it is highly preferable to handle it in the form of a diluted solution of alkaline water. The alkalinity is 9 at pH value.
To 14, more preferably 10 to 13.8. As a means for achieving the above-mentioned pH value, it is preferable to achieve this by dissolving one selected from sodium hydroxide, potassium hydroxide, lithium hydroxide and the like. On the other hand, the active silanol group-containing prepolymer (II-2) may be prepared as a diluted solution of acidic water having a pH value of 0.1 to 6 without any particular limitation. For example, a small amount of a known inorganic acid or water-soluble organic acid may coexist to form a water-diluted solution in the pH range.

In the (II) water-soluble organic polymer, a water-soluble organic polymer that is non-reactive with so-called alkaline water glass represented by one and / or two or more of the above (a) to (h) is used. The active silyl group-containing prepolymer (II-
It is used without any problem when used in combination with 1), and its compounding ratio is from (1: 100) to the weight ratio represented by non-reactive water-soluble organic polymer: active silyl group-containing prepolymer.
(100: 1).

As the water-soluble organic polymer component (II), the active silyl group-containing prepolymer (II-1) is more preferable than the active silanol group-containing prepolymer (II-2) because of the stability of the aqueous solution itself. Is more advantageous in the non-reactive water-soluble organic polymer than in the active silyl group-containing prepolymer (II-1).

(II) The minimum compounding amount of the water-soluble organic polymer is as follows.
It is expressed by the amount (range) that forms the mold multiphase solution, while it is important to use the maximum blending amount so that the viscosity of the system does not exceed 50 poise as measured by a Brookfield viscometer. Although not particularly limited, (a) when the water glass solution composition is made into a two-part main component type, the content of the main component liquid A and / or the curing agent liquid B is approximately 2.5 to 50% by weight. %, More preferably 5 to 35% by weight. The reason is that when the content is 2.5% by weight or less, it is difficult to form a heterogeneous phase, and when the content is 50% by weight or more, it tends to be economically disadvantageous. The content of (II) in the range of 2.5 to 50% by weight does not particularly limit the present invention.

Next, the water glass hardener (III), which is one of the essential components of the water glass solution composition according to the present invention, will be described in detail. The (III) water glass curing agent is preferably included as long as it is a known alkali water glass curing agent or a water-soluble substance having the function, and there is no particular limitation. Representative examples are listed below. I do. For example, inorganic acids represented by hydrochloric acid, nitric acid, sulfuric acid, boric acid, phosphoric acid, etc., inorganic acids represented by water-soluble bisulfates, water-soluble bicarbonates, water-soluble acid sulfates, water-soluble acid phosphates Examples thereof include salts, water-soluble organic acids, and a water-soluble organic monomeric curing agent that releases a sustained-release acid in alkaline water. A preferable example is one obtained by combining one or more of these.

The above sulfuric acid may be any commercially available one, and may be crude sulfuric acid, purified sulfuric acid, concentrated sulfuric acid, dilute sulfuric acid solution, sulfuric anhydride, or the like. Similarly, the phosphoric acid may be crude phosphoric acid or purified phosphoric acid derived from phosphate rock, sulfuric acid, and water and produced through a decalcification and defluorination step, or a dilute solution thereof. Specific examples of water-soluble bisulfates include, for example, sodium bisulfate,
Examples thereof include potassium bisulfate and lithium bisulfate. Examples of the water-soluble bicarbonate include sodium bicarbonate, potassium bicarbonate, lithium bicarbonate and the like. Specific examples of the water-soluble acidic sulfates include, for example, magnesium sulfate. Examples of the water-soluble acidic phosphate include sodium dihydrogen phosphate, potassium dihydrogen phosphate, sodium acid pyrophosphate, potassium acid pyrophosphate, sodium metaphosphate and potassium metaphosphate.

Examples of the water-soluble organic acids include formic acid, acetic anhydride or acetic acid, glycolic acid, glyoxylic acid, lactic acid, malic acid, sorbic acid, phytic acid, abietic acid and the like, and water-soluble acidic salts thereof. Examples of the most preferable water-soluble organic acids include acetic anhydride or acetic acid, phytic acid and acid salts thereof.

Examples of the water-soluble organic monomeric curing agent which releases a sustained-release acid in alkaline water include water-soluble aldehyde compounds represented by glyoxal, and alkylene carbonate compounds such as ethylene carbonate and propylene carbonate. , Cyclic lactones represented by γ-butyrolactone, acetate compounds of low molecular weight glycols represented by ethylene diacetate (hereinafter also referred to as ethylene glycol diacetate), dimethyl succinate, diethyl succinate, Dipropyl succinate, dimethyl adipic ester,
Diethyl adipate, dipropyl adipate, dimethyl maleate, diethyl maleate, dipropyl maleate, dimethyl itaconate, diethyl itaconate,
Examples include alkyl esters of dibasic acid represented by dipropyl ester of itaconic acid (also referred to as alkyl esters of dicarboxylic acids in the following description).

(III) More preferably, as a water glass curing agent, a water-soluble organic monomeric curing agent which releases a sustained-release acid in alkaline water is a water-soluble alkylene carbonate, a water-soluble lactone, or a water-soluble alkylene glycol diene. An embodiment in which one or more selected from an acetate compound, a water-soluble dicarboxylic acid alkyl ester and the like, and a water-soluble organic compound which releases a slow-release acid in alkaline water with one of the above-mentioned inorganic acids An embodiment in which one kind of curing agent is always used in combination, and one kind selected from hydrochloric acid, water-soluble bicarbonates, sulfuric acid, water-soluble bisulfates, phosphoric acid and / or water-soluble acid salts thereof Or an embodiment comprising two or more kinds, an embodiment using high-pressure carbon dioxide or liquefied carbonated water, one kind selected from water-soluble acidic salts, and a water-soluble organic monomer which releases a sustained-release acid in alkaline water Always combination aspect examples and the like formed by the one agent may be mentioned as it preferable, respectively.

Here, when glyoxal is used alone for (III), gelation generally has a characteristic that it progresses slowly in proportion to its use ratio. In other words, it is easy to give a gel time characteristic of a medium to ultra-long type. On the other hand, (II
I) is a water-soluble alkylene glycol diacetate compound, among which mono- and / or diacetylated alkylene glycol represented by an integer of 2 to 4 carbon atoms or di- and / or tri-acetate of glycerin. When at least one kind is used, the gel time is relatively fast for its use ratio. In other words, (A) (II) contained in the water glass solution composition
In the comparison in which the molar concentration of I) is constant, glyoxal is mentioned as (III) whose action and effect are relatively moderate, and a water-soluble alkylene glycol diacetate compound is shown as (III) whose action and effect are strong. Examples thereof include alkylene carbonates and dicarboxylic acid alkyl esters. Cyclic lactones are positioned between them.

Examples of the water-soluble alkylene glycol diacetate compounds other than ethylene diacetate include, for example, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol and the like. Preferred examples include mono- and / or di-acetylated products.

Further, as the more preferable substance (III) according to the present invention, it is more preferable to use a single system of ethylene carbonate or propylene carbonate or a single system of γ-butyrolactone. One of the reasons
One of the advantages is that a product having a high purity can be easily obtained, and the storage stability of the curing agent liquid B according to the present invention can be further secured. The second reason is that it can be said that in the water glass solution composition, the liquid phase containing a large amount of the above (I) alkali water glass is a component (III) suitable for a sea phase.

The mixing ratio of the (III) water glass curing agent in the (a) water glass solution composition described in the present invention is the total alkali content of the (I) alkali water glass present in the composition, ie, ( Na ₂ O + K ₂ O), corresponding to 5 to 400 mol% of the total molar equivalent of the total alkali content,
Preferably, it is blended in a molar equivalent of 10 to 300 mol%, and even more preferably 50 to 250 mol%.

In particular, in the case of the embodiment in which the (a) water glass solution composition described in the present invention is of a two-component type, the main component solution A
When mixed with the total amount of the above, the above ratio, preferably 50 to 250 mol%, relative to the total molar equivalent of the alkali component represented by (Na ₂ O + K ₂ O) contained in the solution A A corresponding amount can be described as a preferred embodiment. When the content is 5 mol% or less, a strong wet gel tends to be hardly generated, and a large amount of a hardening agent is required for a certain amount of the base material, and the performance and the price tend to be unbalanced. In the case of 400 mol% or more,
This tends to be disadvantageous in that it cannot bring out any more significant advantages in the strength and durability of the gel to be produced, and in terms of cost.

Next, (IV) the water component is not particularly limited.
For example, groundwater, spring water, rainwater, river water, lake water, ion exchange water, pure water, tap water, seawater, etc. can be preferably used.

The method for producing a high-strength lightweight silica airgel molded article of the present invention comprises, as (1), pouring the water glass solution composition (a) into a moldable mold container;
The gel is allowed to stand for gelation at a temperature of less than 80 ° C., and a wet gel having a gel strength of at least 2 kgf / cm ² or more is obtained by demolding the wet gel. This is a manufacturing method for obtaining a high-strength and lightweight silica airgel molded body by a method of drying and / or removing organic substances by sintering.

The mold container that can be released is not particularly limited.
Generally, it is preferable to use a material having high dimensional stability, such as a steel container or a hard plastic container. By applying a known release agent in advance to the inner surface of the container during molding, a high-strength wet gel derived from the (a) water glass solution composition according to the present invention can be easily removed from the container. It is preferable to use a material that has been surface-treated as described above.

In the method for producing a high-strength lightweight silica airgel of the present invention, it is important that (a) the water glass solution composition is poured into the mold and gelled by standing. It is important to keep the gelation temperature in the range of 5 ° C. to 80 ° C.
At a low temperature of less than 5 ° C., the gelation time is remarkably prolonged, and productivity and economy tend to be lacking. On the other hand, when the temperature exceeds 80 ° C., on the contrary, the gelation becomes extremely fast, and the uniform O /
This is because it tends to be difficult to obtain a large molded body made of a wet gel having a W-type multiphase structure. A more preferable gelling aging temperature is in the range of 10 to 50 ° C, and most preferably in the range of 15 to 35 ° C, from the viewpoint of reproducibility.

In the method for producing a high-strength lightweight silica airgel molded article of the present invention, the strength of the wet gel at the time of demolding is at least 2 kgf / cm ² or more, preferably 5 kgf / cm ^2.
It is important that the final strength is in the range of not less than ² cm ² , most preferably 7 kgf / cm ² , that is, curing within a certain period of time until the strength of the generated wet gel reaches the above value. The next important point is going through the training course. This is because a wet gel that does not reach ² kgf / cm ² is often undesirably cracked or chipped during demolding.

The curing or aging step (hereinafter referred to collectively as the curing step) is not particularly limited.
II) Curing step of the wet gel produced from the (a) water glass solution composition according to the present invention, which comprises a water-soluble organic monomeric curing agent that releases a sustained-release acid in alkaline water to the water glass curing agent. Although it is not particularly limited, for example, at room temperature for about 3 hours to 28 days,
Typically, it is about 0 minute to 10 days. In addition, for example, it is produced from the (a) water glass solution composition according to the present invention comprising a combined system of (III) a water glass curing agent and an inorganic acid and a water-soluble organic monomeric curing agent which releases a sustained release acid in alkaline water. Although there is no particular limitation in the curing step of the wet gel, the time is preferably, for example, about 1 hour to 120 hours at room temperature. As a curing method, a method of promoting heat curing under high pressure in an autoclave container, a method of promoting curing by immersing in a hot water bath, a method of immersing in an organic solvent warm bath for a certain time, and the like are appropriately adopted. Are also preferably included in the method for producing a high-strength lightweight silica airgel molded article of the present invention.

Examples of the more preferable high-strength lightweight silica airgel molded article (1) include the following (2) to (2).
(21), which is a more preferable production method in the order of description. (2) (a) The water glass solution composition is of a two-part type consisting of an aqueous solution containing alkaline water glass and a base liquid A and an aqueous solution containing a water glass hardener as a hardener liquid B. One or both of the liquids are contained in advance, and the main liquid A and the hardener liquid B are mixed with the main liquid A:
(10: 100) ~ by volume mixing ratio represented by hardener liquid B
The method for producing a high-strength lightweight silica airgel molded article according to (1), wherein the molded article is mixed in the range of (100: 10).

(3) The high-strength lightweight silica aerogel according to (1) or (2), wherein the entire amount of the water-soluble organic polymer is previously blended with the curing agent liquid B containing a water glass curing agent. Manufacturing method of molded body. (4) The alkali water glass is sodium silicate and / or potassium silicate in a molar ratio represented by SiO ₂ / Na ₂ O and / or SiO ₂ / K ₂ O in the range of 1 to 4.5. The method for producing a high-strength lightweight silica airgel molded article according to any one of (1) to (3). (5) The method for producing a high-strength lightweight silica airgel molded article according to (4), wherein the alkali water glass is a sodium silicate solution according to Japanese Industrial Standards, JIS-3.

(6) An aqueous organic polymer exhibiting the property of being compatible with water and / or stabilizing microdispersion at any ratio with water is one selected from the following (a) to (h) and / or
Or (1) to (5) characterized by comprising two or more types
The method for producing a high-strength lightweight silica airgel molded article according to any one of the above. (A) water-soluble polyether polyol (b) water-soluble polyvinyl alcohol (c) water-soluble starch (d) water-soluble cellulose derivative (e) water-soluble polyalkylene oxide (f) water-soluble acryl (g) water-soluble polyepoxide ( h) Water-soluble urethane

(7) A compound of the formula I wherein a water-soluble organic polymer exhibiting a property of being compatible with and / or stabilizing the micro-dispersion in water at any ratio is crosslinked with siloxane by hydrolysis.

Formula I; -Si (R ¹ ) _n- (X) _3-n (where R ¹ is ^one selected from a hydrogen atom, a chlorine atom, a methyl group, an ethyl group, and a propyl group, and X is Carbon number is 1
N is a kind selected from an alkoxyl group, an oxime group, and an acetoxyl group represented by an integer of 5; The active silyl group terminal represented by the formula (1) is introduced in an average of at least 0.7 or more in one molecule, and the main chain excluding the active silyl group is water-soluble, from acrylic, urethane, polyether, polyether polyester, polyester. One or more selected compounds having a weight average molecular weight of 2,
Any one of (1) to (6), wherein the active silyl group-containing prepolymer in the range of 000 to 50,000 and / or an active silanol group-containing prepolymer which is a hydrolysis product thereof is used. A method for producing a high-strength lightweight silica airgel molded body according to the above-described item.

(8) The water-soluble organic polymer exhibiting a property of being compatible with and / or stabilizing micro-dispersion with water at any ratio is one of the above-mentioned (a) and (b) and / or
Used in combination with a so-called alkaline water glass and a non-reactive water-soluble organic polymer represented by at least one kind and the active silyl group-containing prepolymer. : Used in a range of (1: 100) to (100: 1) in a weight ratio represented by an active silyl group-containing prepolymer, wherein A method for producing a strong lightweight silica airgel molded article. (9) The water glass curing agent is at least one or two selected from a water-soluble organic acid, a water-soluble organic monocuring agent that releases a sustained-release acid in alkaline water, an inorganic curing agent, CO _{2, and the} like. The method for producing a high-strength lightweight silica airgel molded article according to any one of (1) to (8), characterized by using the above.

(10) Water-soluble organic monomeric hardeners that release a sustained-release acid in alkaline water include water-soluble alkylene carbonates, water-soluble lactones, water-soluble alkylene glycol diacetate compounds, and water-soluble dibasic acids. (9) The method for producing a high-strength lightweight silica airgel molded article according to (9), wherein one or more selected from alkyl esters and the like are used. (11) (1) The method according to any one of (1) to (10), wherein the water glass solution composition further contains a polymer surfactant in a range of 0.001 to 5% by weight. The method for producing a high-strength lightweight silica airgel molded article according to the above. (12) (1) When the water glass solution composition is gelled, organic fibers and / or inorganic fibers that can be more uniformly dispersed are compounded in a proportion of 0.1 to 10% by weight in the gel. The method for producing a high-strength lightweight silica airgel molded article according to any one of (1) to (11), which is characterized in that:

(13) In the (1) water glass solution composition of the two-liquid type, the two liquids of the main agent and the curing agent are each reduced to approximately 1: 1 in a volume mixing ratio represented by the main agent liquid: the curing agent liquid. (1)-(12) characterized by being mixed and adjusted by approximation.
The method for producing a high-strength lightweight silica airgel molded article according to any one of the above. (14) The high-strength light weight according to any one of (2) to (13), wherein the alkaline water glass content in the main component liquid A is contained so as to be 5 to 50% by weight in terms of solid content. A method for producing a silica airgel molded body. (15) When mixed with the entire amount of the main solution A, the main solution A
A water glass hardener corresponding to 50 to 250 mol% of an alkali represented by Na ₂ O and / or K ₂ O therein;
An aqueous solution containing 2.5 to 50% by weight of a water-soluble organic polymer exhibiting the property of being compatible with and / or stabilizing micro-dispersion in water at any ratio in the curing agent liquid. The method for producing a high-strength lightweight silica airgel molded article according to any one of (2) to (14), which is used as the curing agent liquid B.

(16) (a) In the water glass solution composition, the main agent liquid A comprises the following main agent liquid E and the curing agent liquid B comprises the following curing agent liquid F ( 2) ~
(15) The method for producing a high-strength lightweight silica airgel molded article according to any of (15). As the main agent liquid E, SiO ₂ / Na ₂
An aqueous solution in which the molar ratio of O is 2.5 to 3.5 and the solid content of alkali water glass is 15 to 40% by weight. When the curing agent liquid F is mixed with the entire amount of the main agent liquid E, the curing liquid E
A water-soluble organic monomeric curing agent that releases a sustained-release organic acid in alkaline water corresponding to 50 to 250 mol% of an alkali component represented by Na ₂ O in the water; And / or 80 to 9 of ethylene oxide at a ratio of the amount of addition modification to glycerin being 100.
One kind of polyether diol and / or polyether triol having a weight average molecular weight of 2,000 to 30,000 obtained by random addition or block addition of 9% by weight and 20 to 1% by weight of propylene oxide. Or, an aqueous solution comprising 5 to 35% by weight of the content of two or more curing agents F in the liquid.

(17) The water glass hardener comprises glyoxal alone or in combination with one or more selected from carbonic acid, sulfuric acid and phosphoric acid and / or an alkali metal hydrogencarbonate or an alkali metal hydrogensulfate, (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (3) that the total amount thereof contains 70 to 200 mol% of the total alkali represented by (Na ₂ O + K ₂ O) of the alkali water glass in the system. 16) The method for producing a high-strength lightweight silica airgel molded article according to any one of the above items 16). (18) Either ethylene carbonate or propylene carbonate alone as a water glass curing agent, and the total amount is 55 to 110 mol% of the total alkali represented by (Na ₂ O + K ₂ O) of the alkali water glass in the system. The method for producing a high-strength, lightweight, porous molded article according to any one of (1) to (16), characterized by containing an amount corresponding to the amount of the molded product. (19) The use of γ-butyrolactone alone as a water glass hardener, and the total alkali content of (Na ₂ O + K ₂ O) 110 of the alkali water glass in the mixed system
The method for producing a high-strength, lightweight silica airgel molded article according to any one of (1) to (16), characterized by containing an amount corresponding to ２１０210 mol%. (20) One type of a water-soluble dicarboxylic acid alkyl ester compound in which an alkyl chain length portion is represented by an integer of 1 to 3 carbon atoms as a water glass curing agent, and a mixture of an alkali water glass in a mixed system ( High strength lightweight silica aerogel according to any one of (1) to (16), characterized by containing an amount corresponding to 55 to 110 mol% of the total alkali represented by (Na ₂ O + K ₂ O). Manufacturing method of molded body.

(21) A water glass solution composition is poured into a steel or plastic releasable mold container and allowed to stand for gelation, and the resulting wet gel has low gel uniaxial compressive strength. When both of them exceed ² kg / cm ^2, they are removed from the mold and further subjected to at least one of the following steps (α) to (δ) to have an apparent density of 0.05 to 0 containing closed cells. (1) to producing a silica airgel molded body in the range of 0.8 g / cm ^3.
(20) The method for producing a high-strength lightweight silica airgel molded article according to any of (20). (Α) Dehydration drying process from room temperature to less than 180 ° C (β) Firing process in air or inert gas at less than 1000 ° C (γ) Cooling / cutting process (δ) Sealer / painting process

The (α) dehydration and drying step from room temperature to less than 180 ° C. is not particularly limited, but may be performed, for example, at 40 ° C. for about 30 days to 1 day, and at 100 to 120 ° C. for about 10 days to 30 minutes. It is preferable that the dewatering and drying be performed until the content of free water in the silica airgel reaches 30% by weight or less, preferably 15% by weight or less, and most preferably 0.01 to 5%. . Further, a known drying method may be adopted as the drying method, for example, solar drying,
Electrothermal heating drying, infrared heating drying, hot air heating drying, electron beam irradiation heating drying, and the like may be used.

In the (β) sintering step in air or inert gas at a temperature lower than 1,000 ° C., known sintering methods and sintering methods may be adopted. A firing method using copying heat can be preferably employed.
Preferably, a low-temperature baking method of less than 800 ° C. is used, and most preferably, a low-temperature baking method in which the temperature is gradually increased from room temperature or a drying temperature of 120 ° C. to 800 ° C. The temperature during firing may be raised or lowered arbitrarily. Most preferably, the method for producing the silica airgel of the present invention through the step (β) after the step (α) is particularly preferable. Still more preferably, in the method for producing silica airgel, which is produced through the step (α) and subsequently through the step (β),
The temperature of the firing step (β) is gradually increased from 120 ° C. to 80
A method for producing silica airgel through a firing method in which the temperature is set to 0 ° C. and the temperature is maintained at the same temperature for 1 to 48 hours is a highly preferable method.

The cooling and cutting step (γ) is not particularly limited, and may be any method such as a room temperature cooling method, a forced cooling method using cold air, and a immersion cooling method using a Freon bath or the like.

In the (ε) sealer / coating step, a known sealer composition or a coating composition comprising an organic polymer and / or an inorganic polymer, which has been used for various known cured inorganic foams, is used as it is. It may be used to achieve the purpose, and there is no particular limitation. Preferred examples include a moisture-curable and / or thermosetting polyester urethane resin composition, a moisture-curable and / or thermosetting acrylic resin composition, a moisture-curable and / or thermosetting silicone resin composition. Object, moisture-curable and / or thermosetting fluororesin composition, thermosetting epoxy resin composition,
Thermosetting melamine resin composition, thermosetting phenol resin composition, thermosetting urea resin composition, hydration-hardening cement composition, hydration-setting plaster composition, hydration-setting slag composition , Their composite sealer compositions and / or coating compositions can be used. There are no restrictions on the application, and brush coating, spray coating, roll coater coating, bar coater coating, or the like may be used. In addition, although there is no particular limitation, a coating amount of, for example, 0.01 to 5 kg / m ² is preferably used.

The high-strength lightweight silica airgel molded article of the present invention is obtained by the production method according to any one of the above (1) to (21), and has a fractured or cut cross section of an optical microscope or an electron microscope. Observed and measured with one of the microscopes, and the number of closed cells built in
A silica airgel molded product comprising a porous structure in a range of 1 μm to less than 1 mm, preferably 1 to 250 μm.

[0104] More preferably, the high-strength lightweight silica airgel molded article of the present invention includes the above (1) to (2).
1) obtained by the method according to any one of 1) and
It is a highly preferred embodiment to incorporate a large number of closed cells having a size of 10 μm and have the closed cells having a 10-18 polyhedral structure with rounded corners. Furthermore, it is a more preferable embodiment of a high-strength lightweight silica airgel molded article in the order shown in the following (24) to (28). (24) The thickness of the cured film forming the continuous phase is 0.1
The high-strength lightweight silica airgel molded article according to (22) or (23), which is in a range of from μm to 5 μm. (25) The high-strength lightweight silica airgel molded article according to any of (22) to (24), wherein the apparent density is in the range of 0.1 to 0.5 g / cm ³ . (26) Any one of (22) to (24), characterized in that a sealer composition and / or a paint composition is applied to one surface, and one surface is cosmetically coated and has water-impermeable properties. High-strength lightweight silica airgel molded body.

(27) A solution or emulsion composition, an acrylic resin composition, a urethane composition, wherein the sealer composition contains the following silicon or fluorine compound:
The high-strength lightweight silica airgel molded article according to (26), wherein the molded article is at least one selected from an epoxy resin composition and the like. (28) The coating composition is characterized by being at least one selected from a solution or emulsion composition containing a silicon or fluorine compound, an acrylic resin composition, a urethane composition, and an epoxy resin composition ( 26) The molded article of high-strength lightweight silica airgel according to the above.

Although the present invention is not particularly limited hereto, (a) a preferable solution viscosity of the water glass solution composition at room temperature is 6 using a No. 4 rotor by a BL viscometer.
Those that exceed 200 ps at zero rotation measurements are not very optimal. This is because a material having a viscosity exceeding 200 ps is too high in viscous resistance and tends to have a remarkable lack of flowability and molding reproducibility at the time of injection of a mold. Good to do.

The use of the high-strength lightweight silica airgel molded article of the present invention is not particularly limited. For example, use as a panel reinforcing core for construction materials, use as a heat insulating panel core, use as a sound insulation material, It may be used in various applications utilizing the characteristics of a porous inorganic molded product, such as the use as an immobilizing material for agricultural and pharmaceutical products.

[0108]

EXAMPLES Examples and comparative examples of the present invention will be shown below, but the parts or percentages described herein mean parts by weight and weight%, respectively, and the present invention is not particularly limited by the examples described. In the examples, O is used as a symbol representing the phase structure.
The symbol / W indicates that the liquid phase containing a large amount of alkali water glass formed a continuous phase, ie, a sea phase, while the liquid phase containing a large amount of a water-soluble organic polymer formed a discontinuous droplet separation phase, ie, an island phase. A phase structure in a state where a heterogeneous and stable mixed solution is formed in the state. The symbol W / O indicates that the liquid phase containing a large amount of water glass forms a discontinuous phase, ie, an island phase, while the liquid phase containing a water-soluble organic polymer forms a continuous phase, ie, a sea phase. This means a phase structure in a state where a stable mixed solution is formed.

The following alkaline water glass components used in Examples and Comparative Examples were used. That is, commercially available JIS-2 sodium silicate water glass (displayed as No.2 water glass), JIS-3 sodium silicate water glass (displayed as No.3 water glass), and JIS-4 sodium silicate water glass (Indicated as No. 4 water glass).

Next, the components represented by the following symbols were used as the water-soluble organic polymer components used in Examples and Comparative Examples. (Symbols and Description of Water-Soluble Organic Polymers) PEG-2,000 Polyethylene glycol having a weight average molecular weight of 1,980 in terms of polystyrene measured by GPC. Soluble in water. PEG-3,000 Polyethylene glycol having a weight average molecular weight of 3,060 expressed in terms of polystyrene by GPC measurement. Soluble in water. PEG-20,000 Polyethylene glycol having a weight average molecular weight of 20,000 expressed in terms of polystyrene by GPC measurement. Soluble in water.

Triol 1 Using glycerin as a starting material, ethylene oxide (EO)
And propylene oxide (PO) are added at a random addition weight ratio of 75:25 to give a hydroxyl value of 5
5 mg KOH / g polyether triol. The molecular weight calculated from the OH value is 3,060, and it is soluble in water. Triol 2 A polyether triol having a hydroxyl value of 57 mgKOH / g obtained by adding and modifying ethylene oxide (EO) and propylene oxide (PO) at a random addition molar ratio of 80:20 using triethanolamine as a starting material. However, the molecular weight calculated from the OH value is 2,950 and is soluble in water. PEO It is a polyalkylene oxide resin, and a trade name of a product of Kurokin Kasei Co., Ltd .: "Alcox R-150" was used.
The weight average molecular weight of the resin is about 130,000 as measured by GPC. Soluble in water. Starch Cationized starch (reagent product), soluble in water. Hydroxyethyl cellulose having a weight average molecular weight of about 80 to 90,000 as measured by HEC GPC. Soluble in water.

PVA Polyvinyl alcohol, trade name "DENKA POVAL K-17" manufactured by Denki Kagaku was used. The resin has a weight average molecular weight of about 75,000 as measured by GPC and a degree of saponification of 99 mol%. Soluble in water. A solution at 80 ° C. consisting of 30 parts of an acrylic monomer consisting of 8: 2 by weight of water-soluble acrylic hydroxy methacrylate and methacrylic acid and 67 parts of ion-exchanged water was adjusted to pH 9-1.
While maintaining at 1, 3 parts of potassium persulfate was added and a polymerization reaction was carried out for 5 hours. Finally, an aqueous solution composed of 30% by weight of an acrylic resin having a weight average molecular weight of 3,640 by GPC was obtained. It was used as hydrophilic acrylic. Water-soluble urethane 1.83 parts of hexamethylene diisocyanate was added to 100 parts of polyethylene glycol having a weight average molecular weight of 9,200 determined from the OH value at 120 ° C. in a nitrogen stream.
For 60 minutes to obtain a water-compatible urethane resin having a weight average molecular weight of 290,000 as measured by GPC.

Emulgen 840S A product of Kao Corporation: trade name "Emulgen 840S" is used as one kind of water-soluble polymer surfactant (nonionic surfactant). Emulgen 840S is a type of polyoxyethylene alkyl ether polymer surfactant, and
(Hydrophie Lipophile Bal
ance) value 17.9.

The following water-soluble organic polymers containing active silyl groups were used. Prepolymer 1 A 1-liter four-necked reaction flask equipped with a reflux condenser was prepared. As a polyether polyol, 500 parts (0.0833 mol) of polyethylene glycol having a weight average molecular weight of 6,000 and γ-isocyanate were used. 35 parts of propyltrimethoxysilane (0.167 mol / active NC
O equivalent) and 0.1 part of an acetylacetone aluminum complex as a catalyst, reacted at 110 ° C. for 5 hours in a nitrogen stream, cooled, and cooled with NCO by a dibutylamine solution method.
0% was confirmed by the group-containing quantitative analysis result, and as a result, an active silyl group-containing prepolymer 1 having an average of two hydrolytically active silyl groups introduced into the terminal of the polyether main chain having a molecular weight of 6,000 was obtained. The active silyl group-containing prepolymer 1
Is a water-soluble solution type resin, and a water-diluted solution containing 5 to 30% by weight thereof is stable for several hours, but has the property of giving a hydrogel in a few minutes when 1% by weight of an inorganic acid catalyst such as phosphoric acid is present. It was the indicated resin.

Prepolymer 2 A 1-liter four-necked reaction flask equipped with a reflux condenser was prepared, and 500 parts (0.163 mol) of triol 1 was prepared.
And γ-isocyanatopropyltriethoxysilane
22.5 parts (0.490 mol / active NCO equivalent) and 0.01 part of dibutyltin oxide as a catalyst were charged, reacted in a nitrogen stream at 80 ° C. for 2 hours, and then cooled.
Almost quantitatively, an active silyl group-containing prepolymer 2 having a molecular weight of 3,060 / polyether main chain having three hydrolytically active silyl group terminals was obtained. The active silyl group-containing prepolymer 2 is a water-soluble solution-type resin, and a water-diluted solution containing 5 to 30% by weight thereof is stable for several hours. It was a resin showing the property of giving a hydrogel in a few minutes.

Prepolymer 3 In the same manner as in the above prepolymer 2, except that the amount of γ-isocyanatopropyltriethoxysilane was changed to 147 parts, the molecular weight was almost quantitatively 3,060 / polyether main chain. To obtain a prepolymer solution 3 containing 96.2% of a resin precursor having three hydrolytically active silyl group terminals and 3.8% of unreacted γ-isocyanatopropyltriethoxysilane. One of the water-soluble organic polymers containing a terminal silyl group
The seed prepolymer 3 showed water solubility, and the 5 to 30% by weight aqueous solution could be handled stably for a long time. Further, the 5 to 30% by weight aqueous solution had a property of producing a transparent hydrogel within several minutes when 1% by weight of an inorganic strong acid solution such as phosphoric acid or sulfuric acid was added.

Prepolymer 4 In the same manner as in the above prepolymer 1, except that 0.167 mol of γ-isocyanatopropyltrimethoxysilane was replaced with the same molar amount of γ-isocyanatopropyltriacetoxysilane. Polymer 4 was obtained. The prepolymer 4, which is one of the terminal silyl group-containing water-soluble organic polymers, exhibited water solubility, and a 5 to 30% by weight aqueous solution could be stably handled for a long time. 5-30% by weight
The aqueous solution had a property of forming a transparent hydrogel within several minutes when 1% by weight of an inorganic strong acid solution such as phosphoric acid or sulfuric acid was added.

Prepolymer 5 In the same manner as in Prepolymer 1 except that 31 parts of γ-isocyanatopropyltrimethoxysilane were used, an average of 1.8 active trimethylsilane groups in one molecule of the prepolymer was obtained. The prepolymer 5 introduced at the molecular terminal was obtained. Prepolymer 5, one of the water-soluble organic polymers containing a terminal silyl group, showed water solubility, and a 5 to 30% by weight aqueous solution could be handled stably for a long time. Also 5
The 30 wt% aqueous solution had a property of forming a transparent hydrogel within 10 minutes when 1 wt% of an inorganic strong acid solution such as phosphoric acid or sulfuric acid was added.

The various test methods in the examples are as follows.

Gel time The time required for the liquidity of the water glass solution composition to completely disappear at a constant temperature. The time within 59 seconds is indicated as [flashing], and 1 to 5 minutes. Within 30 minutes is displayed as [medium], within 5 to 30 minutes is displayed as [medium long], 30 minutes or more and 1
Those that were shorter than the time were designated as [long-lasting]. In addition, an item that takes one hour to one day and night is indicated as [ultra long-lasting].

Wet Gel Strength The water glass solution composition was allowed to stand for gelation, and was 15 mm thick.
After obtaining a 50 mm × 50 mm plate-shaped wet gel molded cured product, it was subjected to a uniaxial compressive strength tester to determine a strength value per unit area leading to breakage, and the value was defined as wet gel strength. The uniaxial compression test was performed by a method in accordance with JIS-A-1216, and the measuring equipment used was SG-20 manufactured by Maruto Seisakusho.
Using a 33B electric single-axis compression tester, compression speed 1 mm
/ Min.

In measuring the volumetric shrinkage during gelation, 180 ml of the water glass solution composition was poured into a cylindrical mold having a diameter of 50 mm and a height of 100 mm, gelled at room temperature, and gelated within 24 hours. The volume was determined, and the value obtained by subtracting the gel volume value from the volume of 180 ml of the water glass solution composition was divided by 180 ml to obtain 10
The value multiplied by 0 was defined as the volume shrinkage.

The appearance, the same density, and the same strength of the airgel 1 were measured using the wet gel cured product molded into a plate having a thickness of 15 mm × 50 mm × 50 mm obtained in each example, under the conditions described in the examples. The unfired silica aerogel 1 obtained by dehydration and drying under the conditions is referred to as aerogel 1, and the appearance of the silica aerogel 1 is visually observed. Also, there is no remarkable crack, but there is a very small warpage within 1 mm, and a symbol of △ is shown. If there is more than 1 mm of warpage and a lot of micro cracks are observed or cracked, it is shown with a symbol of x. did. The apparent density measurement result of the silica airgel 1 is simply indicated as the density of the airgel 1 in each table. Further, the results of the uniaxial compressive strength test of the silica airgel 1 are simply indicated as the airgel 1 strength in each table.

The appearance, the same density and the same strength of the aerogel 2 were measured using the cured wet gel obtained in each example and molded into a plate having a size of 15 mm × 50 mm × 50 mm. The silica aerogel 2 produced by baking and removing the organic material below is simply referred to as aerogel 2, and the appearance of the silica aerogel 2 is visually observed. ,
In addition, there is no remarkable crack, but the case where there is a very small warpage within 1 mm is indicated by the symbol △, and the case where the warp exceeding 1 mm and generation and cracks of many micro cracks are observed are indicated by x.
The symbol was used. The apparent density measurement result of the silica airgel 2 is simply indicated as the density of the airgel 2 in each table. Further, the results of the uniaxial compressive strength test of the silica airgel 2 are simply indicated as the airgel 2 strength in each table.

Water resistance of aerogel The silica aerogel 3 obtained by calcining and removing organic substances by heating the plate-like wet gel having a thickness of 15 mm × 50 mm × 50 mm obtained in each example from room temperature to 800 ° C. Cool and take out, thickness 15mm x 25mm x 50mm
And cut in half. The compressive strength value before the test is measured from one of them, and the value is set as the reference value 100 before the water resistance test.
On the other hand, another sample piece was immersed in warm water at 40 ° C. for 30 days, then taken out, and dried again at 40 ° C. for 3 days.
When the axial compression test was carried out and the change in appearance and the strength retention after water immersion were secured by 90% or more, the symbol 記号 showed almost no change in appearance and the strength retention was 70 to 8
When it is at 9.9%, the symbol “O” indicates that the strength retention rate is 50%.
If it is within the range of ７９79.9%, it is represented by the symbol △, and if it is less than that, it is represented by the symbol x.

Sample 20 adjusted to 20 ° C. in a beaker of 300 ml capacity
Take 0 ml and display with the value measured using a BL or BM viscometer.

[0127] Na ₂ contained in the base material liquid A fluid when theoretical neutralization rate for Na2O described in theoretical neutralization ratio Incidentally tables for Na ₂ O (%) and is that together with the entire amount of the base material liquid A solution It means the theoretical neutralization rate when it is assumed that the water glass curing agent in the curing agent B liquid has acted 100% with respect to the alkali represented by O.

Examples 1 to 5 As main agent liquid A, 50 to 65 ml of JIS-3 sodium silicate water glass having a specific gravity of 1.41 and remaining tap water were prepared as shown in Table 1, respectively. On the other hand, as the curing agent liquid B, PEG-3, which is one of water-soluble organic polymers,
000, PEG-20,000, Polyol 1 and water glass hardener as purified phosphoric acid having a purity of 75%, a glyoxal solution having a purity of 40%, γ-butyrolactone, ethylene carbonate, and ethylene acetic acid. Each hardener liquid B was prepared. In addition, in the curing agent B liquid of Table 1, the relationship between the total volume and the blending part of each component is as follows. First, each component other than water is placed in a measuring cylinder as a method of adjusting the curing agent B liquid in each embodiment. It indicates that the sample was collected and the remaining water was added to adjust the total volume.

The main agent liquid A and the curing agent liquid B were heated at 23 ° C.
Under an atmosphere, they were mixed in a two-shot system according to the volume ratio described in Table 1 and poured into a molding container, and each was mixed with a water glass solution composition number GU1 (Example 1), a water glass solution composition number GU2 (Example 2), Water glass solution composition number G
U3 (Example 3), water glass solution composition number GU4 (Example 4), water glass solution composition number GU5 (Example 5)
And the resulting solution was allowed to stand for gelation and left for about 24 hours to prepare a wet gel molded body of each example.

A drop of each water glass solution composition was placed on a slide glass, a cover glass was placed on the slide glass, and the mixture was examined with a phase-contrast optical microscope to determine whether or not the admixture had a non-uniform sea-island structure. Was observed. The results are shown in the column of the observation results of the mixture in Table 1. The microscopic observation is continued until the gelation of the water glass solution composition, and the opaque silicate colloid gel that precipitates is observed in which phase, and the sea phase becomes dense and opaque (forming a gelled network structure). In the case where it is determined from the observation result that the composition has the property of giving a wet gel in which the alkali water glass-containing phase forms a sea phase, the composition is determined to have an O / W type phase structure, and is shown in Table 1. It was indicated as O / W type.

Table 1 shows the solution viscosity results of the water glass solution compositions and the gel physical properties of the wet gels taken out 24 hours after gelation. In addition, for the measurement of the physical properties of the silica aerogel 1 along with the measurement of the physical properties of the wet gel, similarly to the measurement of the physical properties of the wet gel, the respective water glass solution compositions of Examples 1 to 5 were heated at a temperature of 20 ± 2 ° C. A plurality of gels were gelled into a plate having a thickness of 15 mm x 50 mm x 50 mm. After curing at room temperature for 3 days, each of the removed wet gel bodies was subjected to the following dehydration and drying test and the baking and removing test of organic substances.

Using one of the wet gel molded bodies of Examples 1 to 5 (a hydrogel molded body taken out from a plate mold having a thickness of 15 mm × 50 mm × 50 mm), the mixture was placed in a drier at 40 ° C. Subjected to a dehydration drying test left for 3-5 days,
The appearance, apparent density, and uniaxial compressive strength characteristics of the resulting silica airgel-1 were measured and described according to the physical properties of the airgel-1 in Table 1. Each of the wet gel molded bodies of Examples 1 to 5 (water-containing gel molded bodies taken out from a plate-shaped mold having a thickness of 15 mm × 50 mm × 50 mm) prepared in Examples 1 to 5 was separately prepared, and each minute was used. 3
The temperature is raised to 800 ° C. in an electric furnace capable of raising the temperature at a constant rate of 800 ° C., and then the firing is continued at a constant temperature of 800 ° C. for about 2 to 3 hours. A firing removal test was performed. The appearance, apparent density, and uniaxial compressive strength of the silica airgel-2 obtained after the test were measured, and the results were described in accordance with the physical properties of the airgel-2 in Table 1.

In the water glass solution composition described in Example 1, the content of the alkali water glass and the water-soluble organic polymer was the same except that the alkali glass and the water-soluble organic polymer were excluded except for the water glass hardener. A composition consisting of a molecule-water ternary system was prepared separately. The composition had almost the same sea-island structure as in Example 1. Then, 200 minutes of the composition was taken into a test tube, and the two layers were forcibly separated for 1 hour by a centrifuge at 5,000 rpm, and each upper layer and lower layer were separated and collected, and the occupied volume was measured. , Upper layer is 35
% By volume and 65% by volume in the lower layer. In addition, 1 g of the upper layer or lower layer was weighed and collected, and JIS-K-1408 was obtained.
(1966) In the presence of a methyl orange indicator, a neutralization titration was performed with a hydrochloric acid solution having a known concentration of about 0.1 mol / liter to determine the alkali amount (Na ₂ O) concentration in the sample. Alkaline water glass concentration in the upper layer liquid is 6.5
%, And the alkaline water glass concentration in the lower layer solution was calculated to be about 21%. That is, the total alkali water glass in the system is reduced to 100
It turned out that 33% of the water was distributed to the upper layer and 67% to the lower layer. The results of alkali analysis of each layer, the results of the distribution equilibrium of each layer collected, and the observation of the microphase structure by optical microscopy were comprehensively determined. The water glass solution composition of Example 1 was of the O / W type without any questions. It was a biphasic solution.

Further, when the water glass curing agent used in the water glass solution composition of Example 1 (20 mpa · sec measured by a B-type viscometer) was taken as 100, except that an amount equivalent to 25 mol% thereof was added. A water glass solution composition (a system that does not gel for several hours) prepared in the same manner was prepared, and the composition was forcibly separated into two layers by a centrifugal separator at 5,000 rpm for 1 hour. The island phase) was 35% by volume as described above, and the lower layer (sea phase) was 65% by volume, and the distribution ratio was the composition comprising the basic three-component system shown in Example 1 above.
That is, alkaline water glass-water-soluble organic polymer-water 3
It turned out that there was no great difference from the result of the component system.

Further, in the image analysis of the sea island using a phase contrast optical microscope observation photograph about 30 seconds after mixing of the composition of Example 1, the occupied area of the sea phase is 66 to 68%, and the occupied area of the island phase is 34 to 68%.
It turned out to be 32%. Based on the above overall results, the water glass solution composition of Example 1 had a continuous phase (sea phase) occupying about 67% by volume at the time of preparation, and the sea phase contained 6% alkali water glass.
It was found that it consisted of a liquid phase distributed more than 7%. In addition, a small piece of the wet gel of Example 1 was partially collected, and 50 to 100 of an optical microscope or a microscope.
Observation of the gel cross section of the cured product magnified to 0 times revealed that the cured product had a biphasic structure having a honeycomb structure. Further, from the image analysis values, it was found that the organic-inorganic composite multiphase gel occupied approximately 77% by volume of the island phase portion and approximately 23% by volume of the continuous phase portion.

Example 1 (Glass solution composition number GU)
A small piece of silica airgel 1 after the dehydration and drying test of 1) is
As a result of observation at an arbitrary magnification of 100 to 50,000 times with a scanning electron microscope, the silicic colloid coagulated phase forms a honeycomb-like continuous phase, mainly having a size of 10 to 100 microns and an average size of 38 microns. Dodecahedron with roundness to 16
A large number of independent bubbles consisting of facepieces were observed to have a structure including the inside. Also, from the same image observation results, it can be seen that the structure near the interface in contact with the cell surface of the continuous inorganic solidified phase is approximately 2 to 2.
The ultrafine siliceous colloidal particles in the range of 5 nm consisted of a cured product having a high-density aggregation. The colloidal particles in the center of the consolidation layer are slightly larger 20 to 30 n.
The cured structure was found to consist of m-size siliceous colloidal particles which were strongly coagulated at high density.

That is, the core layer of the hardened layer, which is three-dimensionally continuous and spreads like a honeycomb, mainly has an aggregated structure of inorganic colloid particles of 20 to 30 nm in size, and the structure of the hardened layer toward the closed cell boundary surface is as follows: Inorganic colloid particle size 2-5
The silica airgel 1 was miniaturized to nm and had a higher density.

A small piece of silica airgel 2 after the baking removal test of the organic matter in Example 1 was observed at an arbitrary magnification of 100 to 50,000 times with a scanning electron microscope in the same manner as described above. It was found that the silica airgel 2 had a void cell occupation volume ratio of about 77% containing closed cells. Moreover, the shape of the fracture surface of the continuous phase is almost like a honeycomb silica aerogel 2.
The thickness of the cured film enclosing the closed-cell film was 0.7 μm at a thin portion, 6 μm at a thick portion, and 4 μm on average. The heat insulating performance of the silica airgel 2 was a high-strength, lightweight silica airgel molded body exhibiting high heat insulation properties comparable to (almost the same as) hard urethane foam used for electric cooling.

Further, the gelation behavior of the water glass solution composition (GU1 composition) shown in Example 1 is not to give a wet gel body having the phase structure immediately after preparation as it is, but to use an alkali water glass. As the curing progressed, the phase structure changed as follows. About 6 continuous phases immediately after preparation
7% by volume and about 33% by volume of the island phase, but when the curing is completed, the ratio is almost 22% by volume of the continuous phase and 78% by the island phase.
The change greatly decreased to% by volume. (Continuous observation of the process from compounding to gelation by optical microscopy resulted in similar results.)

Also, in the water glass solution compositions of Examples 2 to 6, as in the case of Example 1, the sea / island volume occupancy ratio immediately after the preparation and the stiffness after forming the cured product were obtained. Sea/
The change behavior phenomenon of the volume composition ratio of the islands was reduced, and all of the gels produced a wet gel having an apparent honeycomb structure and silica airgel 1 or silica airgel 2.

Next, in the water glass solution composition described in Example 2, droplets immediately after preparation were collected, and the images observed by a phase contrast optical microscope were analyzed.
The O / W type solution in which the island phase is 17% by volume, and in the generated wet gel, the occupied volume ratio of the sea phase containing the 5-20 micron size droplet island phase is about 20%, and the island phase is occupied. The O / W type hydrogel was about 80% by volume. In addition, the silica airgel 2 obtained by firing and removing the organic substance has about 20% of the area occupied by the inorganic hardened phase and about 80% of the area occupied by the closed cells, which are almost the same values as those of the wet gel body. It was a lightweight silica airgel molded body.

The water glass solution composition described in Example 3 was separately prepared, and immediately, the volume distribution of the sea phase was 68% and the volume distribution of the island phase was 32% by image photograph analysis using a phase contrast optical microscope. It turns out. Also, using the 200 volume parts, 3
5 to 10 g of the upper layer and the lower layer, which were forcibly separated into two layers by a centrifugal separator of 000 rpm for 1 to 2 minutes, were weighed, and concentrated hydrochloric acid 10 to 10 g according to JIS-K-1408 (1966). 20 ml was added to evaporate to dryness, and the precipitated solid was washed with pure water, filtered and dried, and quantified as SiO ₂ . From the SiO ₂ concentration, it was calculated that the concentration of alkaline water glass in the upper layer liquid was about 5% and the concentration of alkaline water glass in the lower layer liquid was about 17%. That is, from the results of the phase-contrast optical microscope image analysis and the results of the alkali water glass concentration distribution analysis, assuming that the total alkali water glass in the system is 100, less than 12% is distributed to the upper layer and more than 88% is distributed to the lower layer. It was found that the distribution ratio of alkaline water glass to the sea phase was 88%.

The silica aerogel 1 after the dehydration and drying test using the formed wet gel is a silica aerogel 1 having an apparently honeycomb-like inorganic hardened phase, and is a value analyzed from an image photograph after gelation by an optical microscope. The molded article was a high-strength lightweight silica airgel molded article in which the area occupied by the inorganic hardened continuous phase occupied 17 to 19% by volume and contained therein a large number of closed cells having a bubble size in the range of about 10 to 150 μm, on average 40 μm. Further, the inorganic cured film was a high-strength lightweight silica airgel molded article having a characteristic in a range of about 0.5 to 5 μm and an average film thickness of about 2.8 μm. The wet gel of Example 3 was O / W
It was a gel of the type, with the sea phase occupying about 22% by volume and the island phase occupying about 78% by volume.

The water glass solution composition described in Example 4 was separately prepared and immediately analyzed by image photograph analysis using a phase-contrast optical microscope or distribution volume ratio measurement by centrifugation, whereby the sea phase distribution ratio was 80% by volume and the island It turned out to be an O / W type solution composition having a phase distribution of 20% by volume. Also, using 200 parts by volume, a two-layer separation was forcibly performed for 1 to 2 minutes by a centrifuge at 30,000 rpm, and 5 to 10 g of the upper or lower layer was weighed and collected to JIS-K-1408 ( According to 1966), 10 to 15 ml of concentrated hydrochloric acid was added, and the mixture was evaporated to dryness by heating. The precipitated solid was washed and filtered with pure water and quantified as SiO ₂ . From the SiO ₂ concentration, it was found that the alkaline water glass content in the upper layer solution was about 6.4% and the alkaline water glass concentration in the lower layer solution was about 16.5%. That is, assuming that the total alkali water glass in the system is 100, slightly less than 10% was distributed to the upper layer (island phase) and more than 90% was distributed to the lower layer (continuous phase / sea phase).

[0145] Five days after curing and curing of the water glass solution composition of Example 4, a small piece of the wet gel broken into about 5 mm in size was washed with pure water, and further dried using a sample of silica aerogel at 40 ° C. As a result of observation with a scanning electron microscope at 100 times or 50,000 times, the existence of closed cells in which the siliceous continuous phase was relatively uniform with an average of 70 μm was observed,
The shape of the closed cell was a dodecahedron having a rounded corner. The continuous phase was silica airgel 1 with a honeycomb matrix structure. Further, the morphology of the silica airgel 1 after the dehydration and drying test was found to be a high-strength lightweight silica airgel having a honeycomb-like structure in which ultrafine siliceous colloidal particles having a size of about 1.5 to 8 nm were closely packed. . In addition, the silicic colloidal particles in the central layer of the cross-sectional film are slightly large 10 to 30 n
A network structure in which the m-size colloidal particles were closely and strongly aggregated was observed. In addition, ethylene carbonate, which is one kind of water-soluble organic monomeric curing agent (water glass curing agent) used in Example 4, is generally appropriately hydrolyzed in alkaline water to obtain CO ₂ (carbonic acid) capable of curing alkaline water glass. Is known as a substance that gradually releases into the system. Therefore, the composition of Example 4 (water glass solution composition No. GU-4) is regarded as a system in which the alkali water glass is hardened by substantial carbon dioxide gas. Can be done.

In the observation image of the silica airgel 1 of Example 4 at a magnification of 100 times by the same scanning electron microscope, the fracture surface of the dried gel was described as a honeycomb shape. Was a dodecahedral to octahedral spherical polyhedron with rounded corners or an elliptical polyhedron. The thickness of the continuous phase forming phase of the silica airgel 1 is 0.7 μm at a thin place, 5 μm at a thick place,
On average, it is 3 μm. According to the structure observation of the Y-shaped cross section, the microphase containing finer closed cells of about 0.1 to 5 μm, which are clearly different from the surrounding core (island) size in some places, Structure was observed.

In the O / W type water glass solution composition described in Example 4, the sea phase was about 80% by volume and the island phase was about 20% by volume.
% Of the solution composition, the ratio is almost reversed at the stage after gelation, and the continuous hardening phase occupancy is about 18% by volume.
A wet gel having an island phase (droplet phase) of about 82% by volume was produced.

The water glass solution composition described in Example 5 was separately prepared, and immediately the result of image photograph analysis using a phase-contrast optical microscope showed that the distribution of the island phase was 18 to 2 as in Example 4.
It was 3% by volume and the sea phase distribution was 77 to 82% by volume. From this result, it was found that even if the type of the water glass hardener was changed, there was no significant difference in the sea-island distribution ratio when the solution was adjusted. Also, using 200 parts by volume, a two-layer separation was forcibly performed for 1 to 2 minutes by a centrifuge at 30,000 revolutions per minute, and 5 to 10 g of the upper or lower layer was weighed and collected to JIS-K-140.
8 (1966), 10 to 15 ml of concentrated hydrochloric acid was added, and the mixture was evaporated to dryness by heating, and the precipitated solid was washed with pure water, filtered, and quantified as SiO ₂ . From the SiO ₂ concentration, it was calculated that the concentration of alkaline water glass in the upper layer liquid was about 6.4%, and the concentration of alkaline water glass in the lower layer liquid was about 16.5%. That is, assuming that the total alkali water glass in the system is 100, slightly less than 10% was distributed to the upper layer (island phase) and more than 90% was distributed to the lower layer (continuous phase / sea phase). It was also found that the cured wet gel had a honeycomb microstructure. Similarly, silica aerogel derived through its drying test or sintering test also has a micro honeycomb-like structure similar to a wet gel, and is a lightweight silica aerogel containing a large number of relatively uniform closed cells with an average of 70 microns. Met.

[0149]

[Table 1]

Examples 6 to 10 50 ml of JIS-2 sodium silicate water glass having a specific gravity of 1.6 or 50 ml of JIS-3 sodium silicate water glass having a specific gravity of 1.41 or a specific gravity of 1 was used as the main component liquid A. A liquid consisting of 50 ml of JIS-4 sodium silicate based water glass of No. 27 and the remaining tap water was prepared as shown in Table 2, while the hardener liquid B was prepared as the water-soluble organic polymer shown in Table 2 and Each curing agent liquid B shown in Table 2 using a water-soluble organic monomeric curing agent which releases a sustained-release acid component in alkaline water
Was prepared. In addition, in the curing agent B liquid in Table 2, the relationship between the total volume and the blending part of each component is as follows. First, each component other than water is placed in a measuring cylinder as a method of adjusting the curing agent B liquid in each example. It indicates that the sample was collected and the remaining water was added to adjust the total volume. After adjusting the liquid temperatures of the main agent liquid A and the curing agent liquid B to about 18 ° C., respectively, the water glass solution composition No. GU6 (Example 6) and the water glass solution composition No. GU7 (Example 6) in accordance with the volume ratios shown in Table 2. Example 7) A water glass solution composition number GU8 (Example 8), a water glass solution composition number GU9 (Example 9), and a water glass solution composition number GU10 (Example 10) were prepared.

Mixing was carried out quickly for 30 seconds, and one drop of the mixture was placed on a slide glass, placed on a cover glass, and viewed with a phase-contrast optical microscope to determine whether or not the mixture was a liquid having an uneven sea-island structure. Observations were made. The results are shown in the column of the observation result of the mixture in Table 2. In addition, the observation of the microscope was continued until the grouting agent gelled, and the opaque silicate colloid gel precipitated was observed in which phase, and the sea phase was thickened and opaque (the phase forming the gelled network structure). )
From the observation result, it was judged that the alkaline water glass-containing phase was a chemical composition having a property of forming a sea phase to give an organic-inorganic composite double-phase gel. did. Table 2 shows the solution properties and silica airgel properties of each water glass solution composition. In addition, the island: sea distribution ratio described in Table 2 means that droplets approximately 30 seconds after the mixing of each water glass solution composition are collected, observed with a phase-contrast optical microscope, and the images are collected, analyzed and calculated. It shows the result of calculating the volume ratio between sea and island phases. For the measurement of the physical properties of each silica airgel, each of the water glass solution compositions of Examples 6 to 10 was liquefied and poured into a quickly releasable container, and allowed to stand for gelation at a temperature of 18 ° C. A plurality of gels were formed into a plate having a thickness of 15 mm x 50 mm x 50 mm. Further, after curing at room temperature for 3 days, each of the removed wet gel bodies was subjected to the following drying test and sintering test.

Using one of the wet gel molded bodies of Examples 6 to 10 (a hydrogel molded body taken out from a plate mold having a thickness of 15 mm × 50 mm × 50 mm), the mixture was placed in a dryer at 80 ° C. After 24 hours, it was subjected to a dehydration drying test.
The appearance, apparent density, and uniaxial compressive strength characteristics of the resulting silica airgel 1 were measured and described according to the physical properties of silica airgel-1 in Table 2. Each of the separately prepared wet gel molded bodies of Examples 6 to 10 (a hydrogel molded body taken out from a plate-shaped mold having a thickness of 15 mm × 50 mm × 50 mm) was prepared at 40 ° C. And then dehydrated and dried for 3 days in an electric furnace capable of raising the temperature at a constant rate of 1 ° C. per minute. Was. Silica airgel obtained in the firing test
The appearance, apparent density, and uniaxial compressive strength characteristics of Sample No. 2 were measured and described in accordance with the physical properties of silica airgel-2 in Table 2.

The water glass solution compositions of Examples 1 to 10 have characteristics of flash-setting type to long-setting type. It is clear that airgel can be produced. In addition, propylene carbonate, which is a kind of water-soluble organic monomeric curing agent (water glass curing agent) used in Example 8, is generally appropriately hydrolyzed in alkaline water to obtain CO ₂ (carbonic acid) capable of curing alkaline water glass. Is known as a substance which gradually releases into the system. Therefore, the composition of Example 8 (water glass solution composition number: GU-8) is regarded as a system in which the alkali water glass is hardened by substantial carbon dioxide gas. I can do things.

[0154]

[Table 2]

Example 11 In the water glass solution compositions of Table 1 and Example 3, 12.6 parts of γ-butyrolactone (corresponding to 140 mol% in the charged molar ratio to the total Na ₂ O in the base solution A) Or N
instead of a 70% equivalent amount of a theoretical neutralization rate for ₂ O), corresponding to 70 mol% in molar ratio to the total Na ₂ O of 7.5 parts of propylene carbonate (in base material liquid A, or Na ₂ Water glass solution composition No. GU-11 obtained in exactly the same manner as in Example 3 except that the theoretical neutralization ratio with respect to O was 70%) was 10 to 10 as in GU-3.
Low viscosity of 12 mpa · sec, the phase structure of the admixture is O
/ W type, a gel composition measured at room temperature of about 1 to 1.5 minutes. The uniaxial compressive strength characteristic of the wet gel cured for one day is 6.3 kgf.
/ Cm ² and an ultrahigh strength characteristic. The silica airgel 1 obtained by drying the wet gel at 50 ° C. for 2 days has a closed cell size of 35 to 150 μm by observation with an optical microscope.
It is a high-strength, lightweight, porous compact with an average density of 75 microns, a micro-honeycomb continuous hardened phase, an apparent density of 0.33 g / cm ³ , and a uniaxial compressive strength of about 10 kgf / cm ^2. Was. In addition, according to the scanning electron microscope observation of the silica airgel 1, the siliceous cured film was thicker by about 0.15 to 0.2 μm than the thickness of the silica airgel 1 obtained in Example 3. Still further, the wet gel is cooled from room temperature to 8
The uniaxial compressive strength of the silica airgel 2 obtained by raising the temperature to 00 ° C. and sintering at 800 ° C. for 5 hours is 18.5 kgf / cm.
² and the external appearance was 、, and the apparent density was 0.15 g / cm ^3, which was a lightweight and high-strength porous compact.

Example 12 In the water glass solution compositions of Table 1 and Example 3, 12.6 parts of γ-butyrolactone (corresponding to 140 mol% in the charged molar ratio to the total Na ₂ O in the main solution A) Or N
6.5 parts of ethylene carbonate (equivalent to 70 mol% in terms of the charged molar ratio to the total Na ₂ O in the main solution A, instead of the theoretical neutralization ratio for a ₂ O of 70%) Equivalent to 70% in terms of the theoretical neutralization ratio to ₂ O). Further, of 10 parts of PEG-20,000, half of the 5 parts were replaced with prepolymer 1 having active trialkoxysilyl group terminals at both terminals. A water glass solution composition obtained in exactly the same manner as in Example 3 except that
As in the above, the viscosity was as low as 10 to 11 mpa · sec, and the phase structure of the admixture was O / W type. The gel time measured at room temperature was about 1.5 to 2 minutes. The uniaxial compressive strength characteristics of the wet gel cured for one day were as high as 8.5 kgf / cm ² . The silica aerogel 1 obtained by drying the wet gel at 50 ° C. for 2 days has an average closed cell size of 65 μm by observation with an optical microscope, has a microscopic honeycomb-like continuous hardened phase, and has an apparent density of 0.32 g. / Cm ² , and the uniaxial compressive strength was about 13 kgf / cm ² , indicating a high-strength lightweight porous compact. Further, the uniaxial compressive strength of the silica airgel 2 obtained by raising the temperature of the wet gel from room temperature to 800 ° C. and sintering at 800 ° C. for 5 hours is about 20 kgf / c.
indicates m ^2, appearance ○, apparent density of 0.15 g / cm ³
And a lightweight and high-strength porous compact.

Example 13 In the water glass solution compositions of Table 1 and Example 5, 75% sulfuric acid 2% was replaced by 2.75 parts of 75% purified phosphoric acid blended in the curing agent liquid B. The water glass solution composition obtained in the same manner as in Example 5 except that the amount was 0.8 parts, had a viscosity of 20 mp.
When it was less than a · sec, it exhibited low-viscosity medium-cured gel characteristics. The wet gel having a strength of 6 kgf / cm ² was obtained, and was almost the same as the GU-5 wet gel of Example 5 with almost no difference in physical properties. In addition, 50 parts of the wet gel
The silica airgel 1 obtained by drying at 2 ° C. for 2 days has a continuous inorganic hardened phase like a micro honeycomb and has an apparent density of 0.2.
It was 9 g / cm ³ and the uniaxial compressive strength was about 12 kgf / cm ² , indicating a high-strength, lightweight, porous compact.

Example 14 A water glass solution composition obtained in the same manner as in Example 5 of Table 1 except that 75% purified phosphoric acid was used in place of 75% purified phosphoric acid and acetic acid was used in an amount equivalent to twice the molar equivalent thereof. The silica aerogel 1 obtained by drying the wet gel at 50 ° C. for 2 days has a continuous hardened phase like a micro honeycomb and has an apparent density of 0.30.
g / cm ³ , and the uniaxial compressive strength was about 12 kgf / cm ² , indicating that it was a high-strength, lightweight, porous compact, which was not much different from the silica airgel 1 obtained in Example 5.

Example 15 Bicarbonate obtained by mixing sodium bicarbonate and potassium bicarbonate in a weight ratio of 1: 1 equivalent to twice the molar equivalent thereof in Example 5 of Table 1 in place of 75% purified phosphoric acid The silica aerogel 1 obtained in exactly the same manner except that the salt was used, had almost the same properties as the silica aerogel 1 obtained in Example 5, such as gel strength, density and water resistance.

Example 16 Bisulfate prepared by mixing sodium hydrogen sulfate and potassium hydrogen sulfate in a weight ratio of 1: 1 corresponding to twice the molar equivalent in Example 5 of Table 1 in place of 75% purified phosphoric acid The silica aerogel 1 obtained in exactly the same manner except that the silica aerogel 1 obtained in Example 5 had almost no change in properties such as gel strength, density and water resistance.

Example 17 A water glass solution composition obtained in exactly the same manner as in Example 5 of Table 1 except that a 75% purified phosphoric acid was replaced by a 2N molar equivalent of a 1N hydrochloric acid solution was used. Gel time 2 minutes 55
Except for slightly faster seconds, the properties of the solution, the wet gel strength properties, and the properties of silica aerogel 1, such as strength, density and water resistance, were almost the same as in Example 5.

Example 18 In the water glass solution composition of Example 6 in Table 2, 15 parts of triol 1 were used instead of 15 parts of triol 3 used.
The water glass solution composition obtained in exactly the same manner as in Example 6 except that it was used as a part was a low-viscosity O / W-type double phase having a solution viscosity of less than 20 mpa · sec, almost in the same manner as in Example 6. The composition was a solution that gave a gel time of 2 minutes and 10 seconds and a uniaxial compressive strength of a wet gel of 13.8 kgf / cm ² . The silica aerogel 1 obtained by dehydrating and drying the obtained wet gel at 40 ° C. for 8 hours and 120 ° C. for 8 hours has an apparent density of 0.44 g / cm ³ ,
It was a lightweight porous compact having a high compressive strength of 16.5 kg / cm ² . From the elemental analysis map analysis of the silica airgel 1, the water glass solution composition of Example 18 was found to be a solution composition in which about 88% or more of the alkali water glass was distributed to the sea phase in terms of the distribution ratio of alkali water glass. It turns out. It was found that the properties of the wet gel and silica airgel of Example 18 were almost the same as the wet gel and silica airgel 1 obtained in Example 6, and a high-strength lightweight silica airgel molded article was produced.

Example 19 The water glass solution composition of Example 7 in Table 2 was obtained in exactly the same manner as in Example 7, except that 2 parts of HEC were used instead of 3 parts of PEO used. The water glass solution composition had a solution viscosity of 30 mpa · s
Low viscosity viscosity less than c, gel time of 5
Min. 40 seconds, wet gel strength is 1.8 kgf / cm ² ,
It was found that the composition was a water glass solution composition having an O / W type double-phase structure, and its wet gel properties were almost the same as those of Example 7.
Were the same as the physical properties of the wet gel obtained in the above. Example 7
Strength of silica airgel 1 produced under the same conditions as
Properties such as density and water resistance were almost the same as those of the silica airgel 1 obtained in Example 7.

Comparative Examples 1 to 5 As shown in Table 3, two liquids of the main liquid A and the hardening liquid B were prepared, and the main liquid A and the hardening liquid B were mixed in the proportions shown in Table 3. Comparative water glass solution composition E-1 (Comparative Example 1), comparative water glass solution composition E-2 (Comparative Example 2), comparative water glass solution composition E-3 (Comparative Example 3), and Water glass solution composition E-4 (Comparative Example 3) and Comparative water glass solution composition E-5 (Comparative Example 5) were each prepared.
In addition, in the curing agent B liquid of Table 3, the relationship between the total volume and the blending part of each component is as follows. First, each component other than water is collected in a measuring cylinder as a method of adjusting each curing agent B liquid. It indicates that the remaining water is added to adjust the total volume.
Each of the water glass solution compositions of Comparative Examples 1 to 5 was subjected to a solution property test, and the results are shown in Table 3. The suitability test for silica aerogel production using the water glass solution compositions of Comparative Examples 1 to 5 was performed as follows, and the suitability results are shown in Table 3.

Suitability test for silica aerogel production suitability Each of the solution compositions, which had been liquefied immediately before being fully filled in a molding container having a height of 15 mm × 50 mm × 50 mm, were quickly poured, and allowed to stand to gel. Thereafter, only the demoldable wet gel molded product obtained by curing for 2 days was placed in a 50 ° C. drier for 3 days, and then a production test of silica airgel 1 was attempted. . In addition, when the generation of cracks leading to a large number of collapses during drying, or the so-called dry collapse phenomenon typified by miniaturization accompanied by severe sun cracking is remarkably observed, it is determined that the production of the silica airgel 1 is impossible, The production was judged to be possible when a silica airgel body having very small microcracks but maintaining the overall shape as it was was determined to be possible, and is shown in Table 3.

Comparative Examples 1 and 2 are compositions comprising an alkali water glass, a water glass hardener, a water-soluble organic polymer and water, like the water glass solution composition according to the present invention.
The system exhibited a homogeneous admixture and gelled without formation of a heterogeneous solution recognizable at the level of optical microscopy until gelling. Observation with a phase-contrast transmission optical microscope revealed that the siliceous colloidal gel was uniformly formed throughout. Therefore, the water glass solution compositions of Comparative Examples 1 and 2 produce only a low-strength wet gel, and have a larger volume shrinkage than those of Examples 2 and 10 and lack dimensional stability at the time of molding. It turns out that there is an issue. In addition, in the aerogel production suitability test, it was found that vigorous drying collapse was observed, so that silica aerogel production was not possible.

Comparative Examples 3 and 4 are compositions comprising alkaline water glass, a water glass hardener, a water-soluble organic polymer and water, as in the water glass solution composition according to the present invention. Since the system presents a W / O-type admixture in which the system is heterogeneous, and the droplet phase containing a large amount of alkali water glass as a main component leads to gelation immediately after preparation while forming a stable island phase, Even if the curing reaction further proceeds as if it were apparently white and cloudy and the viscosity was solidified, the system merely turned into a paste and could not be removed. The behavior of the siliceous colloidal gel precipitated as a solid coagulated island phase having an apparent size of 200 to 400 microns was also observed by phase-contrast transmission optical microscope observation. Therefore, subsequent tests of the physical properties of the wet gel and the suitability of the silica aerogel were not performed. That is, as shown in Comparative Examples 3 and 4, a W / O containing alkali water glass, a water glass hardener, a water-soluble organic polymer, and water.
With the water glass solution composition of the mold type, a porous inorganic molded article having high strength, high water resistance, and excellent heat insulating properties, which is the object of the present invention, could not be produced.

Comparative Example 5 is a water glass solution composition comprising an alkali water glass, a water glass hardener, and water.
Since the water-soluble organic polymer was naturally not contained, the solution almost became a uniform solution at the time of preparation in a system from mixing to gelling.
The wet gel strength derived from the water glass solution composition of Comparative Example 5 was a low-strength water-containing gel of less than 0.7 kgf / cm ² , and was subjected to a silica aerogel production suitability test. The results are shown in Table 3. Thus, it was determined that production suitability was not possible. Incidentally, in the silica aerogel production suitability test, many collapses leading to cracks were observed, and it was not possible to obtain a lightweight silica aerogel 1 maintaining a molded shape.

Further, the wet gel of Comparative Example 5, which was sealed at room temperature and cured for 5 days, was freeze-dried with liquid nitrogen.
A small piece of powder having a size of mm
As a result of observing the morphology of the silica airgel at a magnification of 000, an analytical image was obtained in which siliceous colloids of about 20 to 30 nm were secondarily aggregated in a coarse and dense state. Accordingly, the microstructure of the wet gel body containing water of Comparative Example 5 having a nonameter size was found to be a hydrous silicic acid colloidal gel in which silicate colloid particles of about 20 to 30 nm were cohesively bonded in a dense state.

[0170]

[Table 3]

Example 20 A main solution consisting of 100 ml of No. 3 water glass and 100 ml of tap water was heated to 45 ° C. and prepared. On the other hand, as a curing agent liquid, one of water-soluble organic polymers was used to determine the OH value. A chemically stoichiometric amount of epichlorohydrin is allowed to act on both terminal hydroxyl groups of polyethylene glycol having a calculated molecular weight of about 9,000, followed by dehydrochlorination and purification to obtain polyethylene glycol diglycidyl having a molecular weight of about 9,140. Ether (also known as a modified epoxide of PEG) 2
2 parts and 49.5 ml of 40% glyoxal (210 in molar equivalent ratio of alkaline water glass to Na ₂ O)
%) And 128 ml of water and heated to 45 ° C. to prepare a solution. A water glass solution composition GU-20 was prepared by mixing and discharging the main agent liquid and the hardener liquid in a two-shot system at a volume ratio of 1: 1.

Alkaline water glass was previously distributed in a solution composed of 100 ml of No. 3 water glass, 22 parts of polyethylene glycol diglycidyl ether having a molecular weight of about 9,140, and 288 parts of water. The relationship between equilibrium and phase structure was investigated. As a result, it was found that the three-component water glass solution composition exhibited a non-uniform and stable sea-island double-phase solution, and the volume distribution of the sea phase was 66% and the volume distribution of the island phase was 34%. Further, from the result of collecting the upper or lower layer separated by centrifugation and conducting component analysis, it was found that the liquid forming the sea phase had an alkaline water glass content of 16.8 to 17% and water of 82 to 82.5
% And the remaining 0.5-0.7% was found to consist of polyethylene glycol diglycidyl ether. The solution forming the island phase has an alkaline water glass concentration of about 4.8 to 5%.
82 to 81.5% of water, remaining 16.5 to 16.
It was found that 7% was a composition of polyethylene glycol diglycidyl ether.

Therefore, in the water glass solution composition composed of the three-component system, the ratio of the alkali water glass distributed to the sea phase was determined to be 87 to 89%. Similarly, the proportion of polyethylene glycol diglycidyl ether distributed to the island phase is required to be 96 to 97%. In addition, the GU-29 water glass solution composition was mixed at an extremely low temperature of 2 ° C. as a temperature at the time of mixing and blending, and the gel time was greatly delayed, and the centrifugation was performed at tens of thousands of revolutions per minute for 5 minutes. The capacity ratio of the upper layer to the lower layer is about 31: 6 for the upper layer: the lower layer.
9, which was almost the same as the distribution capacity ratio of the three-component system (the upper layer: the lower layer: 34:66). The alkali water glass content calculated based on the silica content analysis value in the separated lower layer sample was also determined to be 17%, and as a result, the quaternary water glass solution composition GU-2 was obtained.
At 0, the proportion of alkaline water glass distributed to the sea phase is 87
８９89%, which was almost the same as the partition ratio in the case of the three components.

The gel time at 45 ° C. of the water glass solution composition GU-20 was as early as 3 minutes or less, and showed a sintering property at the temperature. On the other hand, the gel time at 25 ° C. is 12 to 1
As long as 5 minutes, it has been found that it has medium-to-long-form characteristics at room temperature.
The wet gel induced to gel at 45 ° C. has an apparent honeycomb-like silicate colloid polymer aggregate layer as a continuous layer and occupies 17 to 18% in volume ratio. One of the wet gels after curing at 45 ° C./day. Axial compressive strength is 14.5Kgf / cm ²
And those with ultra-high strength properties were produced. The volume shrinkage after the curing was as low as 2% or less. GU with this property
The silica airgel 1 produced by further placing the -20 wet gel molded body in a dryer at 50 ° C. for 2 days has an O appearance, an apparent density of 0.22 g / cm ³ , and a uniaxial compressive strength of 1
It turned out to be 9 kg / cm ^2, which proved that the silica airgel 1 having a light weight and an ultra-high strength was produced.

Further, the wet gel molded body of GU-20 having the above characteristics is further subjected to a drying and removing test of organic substances, which is fired in air from room temperature to 800 ° C. at a rate of 3 ° C./minute at a constant speed. As a result, the appearance was Δ, but the apparent density was about 0.15 g / cm ³ , and the maximum uniaxial compressive strength was 27 kg.
/ Cm ² , and a silica airgel 2 having a heat insulating property comparable to that of a known hard urethane foam for electric cooling.

Comparative Example 6 200 ml of a base solution composed of 100 ml of No. 3 water glass and 100 ml of tap water was heated to 25 ° C. and prepared.
200 ml of a curing agent solution prepared by heating at 25 ° C., comprising 49.5 ml of 40% glyoxal (210% in molar equivalent ratio of alkali water glass to Na ₂ O) and 150.5 ml of water, were prepared. A comparative water glass solution composition E- composed of a uniform system formed by mixing and discharging the main agent liquid and the hardener liquid in a two-shot system at a volume ratio of 1: 1.
6 was obtained. The comparative water glass solution composition E-6 heated to 25 ° C. had solution properties such that the gel time was 23 minutes and 11 seconds (medium-long sintering) and the solution viscosity was 5 mpa · sec. The uniaxial compressive strength of the wet gel obtained by sealing and curing for one day after gelation of E-6 is 0.62 kg.
f / cm ² (fracture strain 2%), and only a very fragile hydrogel was produced. The gel strength of the manufactured E-6 wet gel obtained by extending the curing up to 10 days is at most about 1 kgf / cm ² , and it is difficult to improve the fragility at all even if the curing time is increased. Was. As a result of a silica aerogel production suitability test in which the wet gel molded body of E-6 having the above properties was further placed in a 50 ° C. drier for 3 days, self-disintegration (cracking) was remarkably observed during drying, so that silica Airgel production proved impossible.

Examples 21 to 25 A liquid consisting of 50 ml of JIS-3 sodium silicate-based water glass having a specific gravity of 1.41 and the remaining tap water was prepared as the main agent liquid A as shown in Table 4, and was cured. Each of the curing agents having the composition shown in Table 4 prepared by using a water-soluble organic polymer containing a terminal silyl group, a water-soluble organic monomeric curing agent, and, if necessary, a water-soluble organic surfactant as the solution B. Liquid B was prepared. In addition, the total capacity (m
The relationship between l) and the compounding part of each component is such that the water-soluble organic polymer having a terminal silyl group and the water-soluble organic monomeric curing agent, and if necessary, the organic surfactant and the like are in the compounding ratio shown in Table 4. Each sample was weighed and collected in a measuring cylinder, and tap water was added thereto to adjust the total volume of the curing agent B liquid shown in Table 4 to indicate that the composition was obtained.

The main component liquid A and the curing agent liquid B were quickly mixed at 20 ° C. in the mixing ratio shown in Table 4, and the water glass solution composition No. GU-21 (Example 21) and the water glass solution composition No. GU -22 (Example 22), water glass solution composition number GU-23 (Example 23), water glass solution composition number GU-24 (Example 24), water glass solution composition number G
200 ml of each of U-25 (Example 25) was prepared. Mixing is carried out quickly for 30 seconds to liquefy, and one drop is placed on a slide glass, the cover glass is gently placed, and the mixture solution has a nonuniform sea-island structure when viewed with a phase-contrast transmission optical microscope. As a result of observing whether or not it was a system having a non-uniform sea-island structure in all the systems of Examples 21 to 25, Table 4 describes only the characteristics of the phase structure, and the results are shown in Table 4. Judgment was made by the symbol of O / W type (a system in which an alkaline water glass solution forms a continuous phase) or W / O type (a system in which an alkaline water glass solution forms an island phase) and described. In addition, each water glass solution composition of Examples 21 to 25, which was quickly mixed for 30 seconds to be liquefied, was gently poured into a predetermined wet gel production mold container, allowed to stand, and gelled. Cured a day. Thereafter, the mold was removed, and each silica airgel 1 was manufactured for each example by the following dehydration and drying methods using the wet gel molded body. Further, using the silica airgel 1, each silica airgel 2 was produced through each of the following firing methods, and the physical properties were evaluated and examined. In addition, the observation result regarding the dimensional stability at the time of the production of the silica airgel 1 or the silica airgel 2 is indicated by the symbol ◎ when the volume change rate is less than 1%, and the symbol ○ when the change is 1.1 to 5%. The symbols are shown in Table 4 below, and those below are indicated by the symbol x.

A three-component mixed solution prepared in exactly the same manner as in the curing agent liquid B of Example 21 except that ethylene carbonate and γ-butyrolactone, which are water glass curing agents, were replaced with tap water. 200 parts were adjusted separately. The solution was collected in a test tube and centrifuged at 500 rpm for 1 hour to separate the two layers. As a result, it was found that the upper layer was 40% by volume and the lower layer was 60% by volume. In addition, about 1 g of each of the upper and lower layers is collected and weighed, and is measured according to JIS-K-14.
As a result of measuring the alkali concentration represented by Na ₂ O in accordance with 08, it was found to be 5.5% in the upper layer and 17.8% in the lower layer.
That is, it was found that, when the alkali water glass charged was 100 in the separately prepared ternary composition, 18% of the alkali water glass had a distribution equilibrium in the upper layer and 82% had a distribution equilibrium in the lower layer. Therefore, the water glass solution composition number GU-
Under the solution immediately after the preparation of No. 21, it was found that the composition had an O / W type sea-island structure. In addition, according to the continuous observation of the sea-island structure and the gelation process of the water glass solution composition No. GU-21 of Example 21 by phase contrast transmission optical microscopy, the phase inversion was achieved while reducing the volume occupied by the sea phase. It gelled without performing, and it was clear that it was an O / W type solution composition.

The results of an examination of the wet gel properties of the water glass solution composition No. GU-21 of Example 21 one day after gelation and curing are shown in Table 4, and the production of silica aerogel 1 derived from the wet gel is shown in Table 4. As a method, 50 ℃
Silica airgel 1 produced by drying for 2 days in
As a result of observation with a scanning electron microscope at 100 times and 50,000 times, a large number of 12 to 18-hedral closed cells with rounded corners having a size of about 40 to 100 μm are included.
So-called silica aerogels 1 having a so-called broken surface in a honeycomb shape are produced, and their apparent densities and strengths are as shown in Table 4.
It was a very lightweight and ultra-high strength silica airgel 1. It is manufactured in Example 21 and has a height of 15 m in advance.
A silica aerogel 2 manufactured by raising the temperature from room temperature to 800 ° C. at 2 ° C. per minute and sintering at 800 ° C. for 12 hours using a wet gel molded body cut to mx 50 mm wide and 50 mm long. Table 5 also shows the results of the density, the same strength, and the water resistance.

The silica airgel 1 produced in Example 21 is an organic-inorganic hybrid type porous double-phase xerogel containing closed cells of 40 to 100 μm, and particularly 20,000 to 50,000 by a scanning electron microscope. The observation result at × 2 shows that the ultra-microstructure (see FIG. 4) near the closed cell membrane of the molded article of the double-phase silica airgel was about 2 to 5 n.
m was formed into a cured film structure in which minute particles were densely cohesively bonded. Further, the ultramicrostructure near the deep layer of the hardened phase had a porous hardened film structure in which ultrafine particles of about 10 to 45 nm in size were finely cohesively bonded. In other words, a localized high-density ultramicrostructure of colloid particles having a smaller size was observed at the surface boundary portion in contact with the bubbles. The thickness of the cured film is 0.5μ
m, a thickness of 3 μm at a thick place, and an average thickness of 1.5 μm. It was found that a silica airgel 1 having a special and fine porous molded body structure was produced.

As described above, 8 of the charged alkaline water glass was used.
Water glass solution composition No. GU- of Example 21 in which the O / W type in which 2% or more is distributed and the sea phase is 60% by volume.
The wet gel derived from No. 21 was a multiphase gel in which the volume distribution ratio represented by the sea phase: the island phase was changed to 19:81. O / W-type multi-phase wet gel can be produced despite the extremely low sea phase volume occupancy of 19% by volume, so that the void gel occupies as closed cells from the wet gel molded body. The ratio was 80% or more, the silica airgel 1 was lightweight, and the uniaxial compressive strength characteristic value of the silica airgel 1 was about 17 to 19 kgf / cm ^2, which was surprisingly high. The uniaxial compressive strength characteristic value of the homogel is 12 kgf
A surprisingly high strength value of / cm ² was obtained.

[0183]

[Table 4]

Next, the water glass solution composition GU of Example 22 was used.
The solution immediately after the preparation of -22 has a sea phase of approximately 77% by volume and an island phase of 23 based on the image observed with a phase contrast optical microscope.
The micro-multiphase solution occupied a volume% and stably contained a droplet phase composed of an island phase having an island phase of 15 to 25 μm.
On the other hand, silica aerogel 1 produced by drying a GU-22 molded gel of GU-22 which has sufficiently gelled at 40 ° C. for 5 days contains closed cells of about 30 to 125 μm, averaging 80 μm. The thickness of the continuous cured film (thickness of the closed-cell shell film) rich in natural mineral is 0.4 to 4
The silica aerogel 1 was composed of an organic-inorganic hybrid biphasic gel having a thickness of 3.5 μm and an average thickness of about 3.5 μm. In the GU-22 water glass solution composition, less than 17% of the total alkali water glass component is distributed to the island phase forming liquid, and more than 83% of the total alkali water glass component is distributed to the sea phase forming liquid. The GU-22 solution composition
The above results were found from the results of the compositional analysis of each liquid separated by centrifugation at a low temperature of ℃. Table 4 shows the physical properties of the silica airgel 2 produced by baking the GU-22 molded wet gel at 80 ° C. for 5 hours and then at 450 ° C. for 20 hours.
As shown in Fig. 5, a silica airgel 2 which is lightweight, rich in ultra-high strength properties and excellent in water resistance was produced. It was also found that the heat insulating performance of the silica airgel 2 had high heat insulating properties comparable to those of rigid urethane foam used for electric cooling. Further, the microstructure of the fractured surface of both the silica airgel 1 and the silica airgel 2 showed an apparent honeycomb shape, and the volume occupied by the closed cells was found to be about 80% by volume.

As a result of separately preparing the water glass solution composition GU-23 of Example 23 shown in Table 4 and measuring the sea-island distribution ratio, it was an O / W type solution. The phase volume distribution was found to be 22%. Using 200 parts by volume cooled to 5 ° C., 5 to 10 g of the upper layer and 5 to 10 g of the lower layer, which were forcibly separated into two layers by a centrifuge at 30,000 rpm for 1 to 2 minutes, were weighed and collected. JIS-K-1
According to 408 (1966), 10 to 20 ml of concentrated hydrochloric acid was added to evaporate to dryness, and the precipitated solid was washed with pure water, filtered and dried, and quantified as SiO ₂ . From the SiO ₂ concentration, it was calculated that the concentration of alkaline water glass in the upper layer liquid was about 7% and the concentration of alkaline water glass in the lower layer liquid was about 13.7%. That is, from the results of the phase-contrast optical microscope image analysis and the results of the alkali water glass concentration distribution analysis, in the solution of the water glass solution composition No. GU-23, when the total alkali water glass amount is 100, less than 17% of the total amount of the alkali water glass is in the upper layer (island phase). )
And more than 83% of the solution was a heterogeneous solution composition distributed to the lower layer (sea phase). Table 4 shows various physical properties of the silica airgel 1 and the silica airgel 2 produced in the same manner as in Example 22. The microstructure of the fracture surface of each of the silica airgel 1 and the silica airgel 2 has an apparent honeycomb shape, and the volume occupied by the closed cells is found to be about 75% by volume. It has been found that the heat insulating performance of the silica airgel 2 has high heat insulating properties comparable to those of rigid urethane foam used for electric cooling.

Water glass solution composition GU-2 of Example 24
4 was prepared separately, and immediately subjected to image photograph analysis using a phase-contrast optical microscope. As a result, it was determined that the solution was an O / W solution, with a sea phase distribution volume ratio of 78% and an island phase volume distribution ratio of 22%. Further, using 200 parts by volume cooled to 3 ° C.,
5 to 10 g of the upper layer and the lower layer which were forcibly separated into two layers by a centrifuge of 2,000 rpm for 1 to 2 minutes were respectively weighed, and 10 to 20 ml of concentrated hydrochloric acid was collected according to JIS-K-1408 (1966). In addition, the mixture was evaporated to dryness, and the precipitated solid was washed with pure water, filtered and dried, and quantified as SiO ₂ .
The concentration of alkali water glass in the upper layer liquid was found to be about 6.9%, and the concentration of alkaline water glass in the lower layer liquid was about 13.6% from the SiO ₂ concentration. That is, from the results of the phase-contrast optical microscope image analysis and the alkali water glass concentration distribution analysis, if the total alkali water glass in the GU-23 solution composition is 100, about 16% of the total alkali water glass is in the upper layer (island phase).
About 84% of the solution was a heterogeneous solution system which was distributed to the lower layer (sea phase). Table 5 shows various physical properties of the silica airgel 1 and the silica airgel 2 produced by the same method as in Example 22. The microstructure of the fracture surface of each of the silica airgel 1 and the silica airgel 2 has an apparent honeycomb shape, and the volume occupied by the closed cells is found to be about 70% by volume. It has been found that the heat insulating performance of the silica airgel 2 has high heat insulating properties comparable to those of rigid urethane foam used for electric cooling.

Water glass solution composition GU-2 of Example 25
No. 5, using 200 parts by volume at 3 ° C., and 30,000 / min
Forcibly separate the two layers with a rotating centrifuge for 1-2 minutes,
5 to 10 g of the upper or lower layer is weighed and collected and JIS
Concentrated hydrochloric acid 10-1 according to -K-1408 (1966)
5 ml was added, and the mixture was heated and evaporated to dryness, and the precipitated solid was washed and filtered with pure water and quantified as SiO ₂ . From the SiO ₂ concentration, it was found that the concentration of the alkali water glass in the upper layer solution was about 5.6%, and the concentration of the alkali water glass in the lower layer solution was about 16%. That is, assuming that the total alkali water glass in the system was 100, an O / W solution composition in which slightly less than 12% was distributed to the upper layer (island phase) and more than 88% was distributed to the lower layer (sea phase). . Table 4 shows various physical properties of the silica airgel 1 and the silica airgel 2 produced in the same manner as in Example 22. The silica aerogel 1 and the silica aerogel 2 both have a microstructure of a fractured surface having an average size of 100 μm and an apparent honeycomb structure containing a large number of 12 to 18-hedral closed cells having relatively rounded corners. It is a gel molded product with a structure, and the closed cell occupies about 70% by volume.
It turns out to be a degree. It has been found that the heat insulating performance of the silica airgel 2 has high heat insulating properties comparable to those of rigid urethane foam used for electric cooling.

From the observation of the produced silica airgel 2 of Example 22 by scanning electron microscopy, the thickness of the continuous hardened phase surrounding the bubbles was 3 μm at a small thickness of 0.3 μm and 3 μm at an average thickness of about 1. It turned out to be 5 microns. It was also found that microscopic irregular bubbles of about 0.5 to 3 microns, which are clearly different from the surrounding bubble size, were incorporated in the inside of the Y-shaped cured cross section.

Comparative Example 7 In the water glass solution composition GU-22 of Example 22 in Table 4, the prepolymer 2 blended in the curing agent solution B was not used at all, and the portion was replaced with tap water. The comparative water glass solution composition E-7, which was prepared in exactly the same manner except that it was water, exhibited a transparent and uniform system, and was not a solution having a micro-sea-island phase structure until gelation. The comparative water glass solution composition E-7 heated to 25 ° C has a solution viscosity of 5 mpa ·
In sec, the gel time was 4 minutes and 40 seconds (medium-long knot type). Further, the uniaxial compressive strength characteristic of the wet gel produced from E-7 was as low as 0.7 kgf / cm ² (the breaking strain was 3%), and only an extremely brittle wet gel molded product was produced. The gel strength of the E-7 wet gel manufactured by extending the curing up to 10 days also has a maximum gel strength of 0.9.
It was about Kgf / cm ² , and it was difficult to improve any fragility even if the curing time was increased. E-7 with this property
As a result of the silica aerogel production suitability test in which the wet gel molded product was further placed in a dryer at 50 ° C. for 3 days, a self-disintegration (cracking) phenomenon, which is considered to be caused by vibration during drying and accumulation of internal stress, was remarkable. Was observed. Therefore, it was concluded that it was impossible to produce a high-strength and lightweight silica aerogel using the fragile wet gel of E-7.

Examples 26 to 30 Five silica airgel 1 moldings obtained in the same manner as the silica airgel 1 produced in Example 6 were prepared, and the following sealant was applied to one side of each of them. And / or a coating composition was applied so as to have a total application amount of 10 kg / cm ² , and was dried and baked at room temperature for 30 minutes and then at 80 ° C. for 30 minutes. -A silica airgel molded body formed by sealing each one side of Example 30 was produced. The properties of the coated surface of the coated silica airgel 1 obtained as a result are also shown in Table 5.

[0191]

[Table 5]

Explanation of symbols Em1; # SH82 manufactured by Dow Corning Toray Co., Ltd.
00 (silicon emulsion). Em2: "Uban", a product of Mitsui Toatsu Chemicals, an aqueous urethane resin, is used. AE Almatex: Uses "Almatex", a product of Mitsui Toatsu Chemicals, a solvent-based acrylic lacquer coating composition. Polycleat: Uses "Polycleat", a product of Mitsui Toatsu Chemicals, a two-part epoxy coating composition. MT Era Style: Uses "MT Era Style" manufactured by Mitsui Toatsu Chemicals, a special acrylic rubber-based emulsion coating composition. Quick-curing urethane; “Rim Spray” is a product of Mitsui Toatsu Chemicals Co., Ltd., which is a two-part, quick-curing urethane coating composition. Criteria for judging the adhesion of the coating film;
゜ The symbol ◎ indicates that there was no peeling with a peel, the symbol 塗膜 indicates that the coating film was very slightly adhered to the cellophane tape, and the symbol x indicates that the undercoat appeared. Judgment of water permeation resistance imparting effect; water permeability coefficient is 1 × 10 ⁻⁶ cc /
sec. or less and a non-permeable material is indicated by a symbol ○, and a symbol in a range of 1 × 10 ^{−4 to} 0.9 × 10 ⁻⁶ cc / sec is indicated by a symbol Δ, and 0.9 × 10 ^{− When} it was bad as ⁴ or more, it was represented by the symbol x.

[0193]

As is evident from the comparison between Examples 1 to 25 and Comparative Examples 1 to 7, a liquid having a non-uniform and stable micro-sea-island structure and containing alkaline water glass as a main component is provided. O according to the present invention, wherein the phase is contained in the sea phase at a high partition ratio.
Using a / W-type water glass solution composition, the O / W-type solution is poured into a mold container that can be removed under a low temperature range, gelled, and cured as necessary. The wet gel to be made is rich in high dimensional stability and high strength compression properties, etc. Also, after manufacturing the wet gel molded body,
Silica airgel produced by a method of heating, dehydrating, drying and / or sintering at a temperature of less than 800 ° C. has a novel structure, and its microstructure can be said to be characterized by a more honeycomb-like microstructure. In addition, the silica airgel body produced by the method for producing a high-strength lightweight porous molded body of the present invention has an ultra-lightweight with an apparent density of less than 0.5 g / cm ³ and an ultra-high strength compressive strength, It has been found that it has excellent dimensional stability when immersed in water and has excellent performance such as having the same heat insulation properties as urethane foam. On the other hand, from each comparative example, in the conventionally known alkaline water glass-containing composition and the water glass solution composition comprising a homogeneous solution system, the purpose of the present invention is to achieve a very light and high compressive strength property and a remarkably improved water resistance. It is clear that it is difficult to produce a high-strength lightweight porous molded body.

[Brief description of the drawings]

FIG. 1 is a scanning electron microscope observation image of a silica airgel 1 produced in Example 2 at a magnification of 100 times.

FIG. 2 is a scanning electron microscope observation image of the silica airgel 2 produced in Example 21 at a magnification of 100 times.

Claims (28)

[Claims] 1. A water glass solution composition of the following (A) is poured into a mold container capable of being separated from the mold and allowed to stand for gelation at a temperature of 5 ° C. to less than 80 ° C.
A method for producing a high-strength lightweight silica airgel molded body, comprising dehydration drying and / or baking off organic matter at a temperature of less than 0 ° C. (B) alkaline water glass as a water glass solution composition,
It contains a water-soluble organic polymer exhibiting compatibility and / or micro-dispersion stabilizing properties in any proportion to water, a water glass hardener, and water, and the solution is composed of a sea phase-island phase. A heterogeneous solution composition having a homogeneous phase structure and at least 60% by weight or more of the total alkali water glass component blended in the solution being distributed to the sea phase. 2. The water glass solution composition of (a) comprises a two-component type of a base liquid A which is an aqueous solution containing alkaline water glass and a hardener liquid B which is an aqueous solution containing a water glass hardener. The polymer is preliminarily contained in one or both of the liquids, and the main agent liquid A and the curing agent liquid B are mixed at a volume mixing ratio represented by main agent liquid A: curing agent liquid B of (10 The method for producing a high-strength lightweight silica airgel molded body according to claim 1, wherein the mixture is mixed in the range of (100) to (100: 10). 3. The high-strength lightweight silica airgel molded article according to claim 1 or 2, wherein the whole amount of the water-soluble organic polymer is previously blended with the curing agent liquid B containing a water glass curing agent. Production method. 4. A method according to claim 1, wherein the alkaline water glass has a molar ratio represented by SiO ₂ / Na ₂ O and / or SiO ₂ / K ₂ O of 1 to 1.
The method for producing a high-strength, lightweight silica airgel molded body according to any one of claims 1 to 3, wherein sodium silicate and / or potassium silicate in the range of 4.5 are used. 5. The alkaline water glass is made of Japanese Industrial Standard / JI
The method for producing a high-strength lightweight silica airgel molded body according to claim 4, wherein the sodium silicate solution of S-3 is used. 6. Compatible with water in any proportion and / or
Alternatively, the water-soluble organic polymer having the property of stabilizing microdispersion is one selected from the following (a) to (h) and / or
The method for producing a high-strength lightweight silica airgel molded article according to any one of claims 1 to 5, wherein the molded article comprises two or more kinds. (A) water-soluble polyether polyol (b) water-soluble polyvinyl alcohol (c) water-soluble starch (d) water-soluble cellulose derivative (e) water-soluble polyalkylene oxide (f) water-soluble acryl (g) water-soluble polyepoxide ( h) Water-soluble urethane 7. Compatible with water in any proportion and / or
Alternatively, a water-soluble organic polymer having the property of stabilizing micro-dispersion is converted into a siloxane by hydrolysis. Formula I: Formula I; -Si (R ¹ ) _n- (X) _3-n (provided that , R ¹ is ^one selected from the group consisting of a hydrogen atom, a chlorine atom, a methyl group, an ethyl group and a propyl group;
Is a kind selected from the group consisting of an alkoxyl group, an oxime group and an acetoxyl group each having an integer of 1 to 5 carbon atoms, and n represents 0 to 1, respectively. The active silyl group terminal represented by the formula (1) is introduced in an average of at least 0.7 or more per molecule, and the main chain excluding the active silyl group is water-soluble, and is made of acrylic, urethane, polyether, polyether polyester or polyester. One or more selected from the group consisting of an active silyl group-containing prepolymer having a weight average molecular weight in the range of 2,000 to 50,000 and / or an active silanol group-containing hydrolysis product thereof; The method for producing a high-strength lightweight silica airgel molded article according to any one of claims 1 to 6, wherein the method is one of prepolymers. 8. Compatible with water in any proportion and / or
Alternatively, the water-soluble organic polymer exhibiting the property of stabilizing micro-dispersion is a water-soluble organic polymer that is non-reactive with alkali water glass represented by one and / or two or more of the above (a) to (h) And the active silyl group-containing prepolymer are used in combination, and the compounding ratio is from (1: 100) to the weight ratio represented by the non-reactive water-soluble organic polymer: active silyl group-containing prepolymer. The method for producing a high-strength lightweight silica airgel molded article according to any one of claims 1 to 7, wherein the molded article is used in the range of (100: 1). 9. The water glass curing agent is at least one selected from the group consisting of a water-soluble organic acid, a water-soluble organic monomeric curing agent which releases a slow-release acid in alkaline water, an inorganic curing agent, and CO _2. The method for producing a high-strength lightweight silica airgel molded article according to any one of claims 1 to 8, wherein one or more kinds are used. 10. The water-soluble organic monomeric curing agent which releases a sustained-release acid in alkaline water is a water-soluble alkylene carbonate, a water-soluble lactone, a water-soluble alkylene glycol diacetate compound and a water-soluble alkyl dibasic acid. The method for producing a high-strength lightweight silica airgel molded body according to claim 9, wherein one or more kinds selected from the group consisting of esters are used. 11. The method according to claim 1, wherein the water glass solution composition of (1) further contains a polymer surfactant in a range of 0.001 to 5% by weight. The method for producing a high-strength lightweight silica airgel molded article according to the above. 12. When the water glass solution composition of (1) is gelled, it is preferable that organic fibers and / or inorganic fibers be further compounded in a proportion of 0.1 to 10% by weight in the gel. A method for producing a high-strength, lightweight silica airgel molded article according to any one of claims 1 to 11. 13. In the water glass solution composition of (1), which is a two-pack type, the two liquids of the base resin and the curing agent are approximately 1: 1 in a volume mixing ratio represented by the base liquid: the curing agent liquid, respectively. The method for producing a high-strength lightweight silica airgel molded article according to any one of claims 1 to 12, wherein the mixture is adjusted by approximation. 14. The high-strength light weight according to any one of claims 2 to 13, wherein the content of the alkaline water glass in the base liquid A is 5 to 50% by weight in terms of solid content. A method for producing a silica airgel molded body. 15. Hardening of water glass corresponding to 50 to 250 mol% of an alkali represented by Na ₂ O and / or K ₂ O in the base liquid A when mixed with the whole amount of the base liquid A. And 2.5 to 50% by weight of a water-soluble organic polymer exhibiting the property of being compatible with and / or stabilizing micro-dispersion in water at any ratio in the curing agent liquid. The method for producing a high-strength lightweight silica airgel molded article according to any one of claims 2 to 14, wherein the aqueous solution is used as the curing agent liquid B. 16. The water-glass solution composition according to (a), wherein the main liquid A comprises the following main liquid E and the curing liquid B comprises the following liquid F. Item 2-1
5. The method for producing a high-strength lightweight silica airgel molded article according to any one of 5. An aqueous solution in which the molar ratio of SiO ₂ / Na ₂ O is 2.5 to 3.5 and the solid content of alkali water glass is 15 to 40% by weight as the main agent liquid E. As the curing agent liquid F,
When mixed with the entire amount of the base liquid E, the N
a water-soluble organic monomeric curing agent that releases a sustained-release organic acid in alkaline water corresponding to 50 to 250 mol% of an alkali component represented by a ₂ O; Alternatively, add 1 denaturation amount to glycerin.
Polyether having a weight average molecular weight in the range of 2,000 to 30,000 obtained by random addition or block addition of 80 to 99% by weight of ethylene oxide and 20 to 1% by weight of propylene oxide at a ratio of 00 One or more diols and / or polyether triols in the curing agent F liquid have a concentration of 5 to 5%.
An aqueous solution containing 35% by weight. 17. The water glass curing agent may be glyoxal alone or in combination with one or more selected from the group consisting of carbonic acid, sulfuric acid and phosphoric acid and / or in combination with an alkali metal hydrogencarbonate or an alkali metal hydrogensulfate. Become
And the total amount of (Na ₂ O) of the alkaline water glass in the system
+ K ₂ O) according to claim, characterized in that to contain the amount corresponding to 70 to 200 mole% of the total alkali content expressed by 1
17. The method for producing a high-strength lightweight silica airgel molded article according to any one of items 16 to 16. 18. Either or both of ethylene carbonate and propylene carbonate are used as a water glass curing agent, and the amount thereof is 55% of the total alkali content represented by (Na ₂ O + K ₂ O) of the alkali water glass in the system. ~ 1
The method for producing a high-strength lightweight silica airgel molded article according to any one of claims 1 to 16, wherein an amount corresponding to 10 mol% is contained. 19. The use of γ-butyrolactone alone as a water glass curing agent and 110 to 210 mol% of the total alkali represented by (Na ₂ O + K ₂ O) of the alkali water glass in the mixed system. The method for producing a high-strength lightweight silica airgel molded article according to any one of claims 1 to 16, wherein an amount corresponding to the amount is contained. 20. Alkaline water glass in a system obtained by mixing and mixing a water-soluble dicarboxylic acid alkyl ester compound having an alkyl chain length represented by an integer of 1 to 3 as a water glass curing agent. of _{(Na 2 O + K 2 O} ) in a high strength light weight silica airgel as claimed in any one of claims 1 to 16, characterized in that to contain the amount corresponding to 55 to 110 mole% of the total alkali content expressed Manufacturing method of molded body. 21. A wet gel gel 1 formed by pouring the water glass solution composition (a) into a steel or plastic releasable molding container and allowing it to stand for gelation.
When the axial compression strength exceeds ² kg / cm ² at least,
After being removed from the mold, silica aerogel molding having an apparent density of 0.05 to 0.8 g / cm ³ containing closed cells through one or more of the following steps (α) to (δ): 21. A body is manufactured.
The method for producing a high-strength lightweight silica airgel molded article according to any one of the above. (Α) Dehydration drying process from room temperature to less than 180 ° C (β) Firing process in air or inert gas at less than 1000 ° C (γ) Cooling / cutting process (δ) Sealer / painting process 22. A high-strength lightweight silica aerogel obtained by any one of the production methods according to claim 1 and having a honeycomb-like microstructure including a large number of closed cells of 1 to 200 μm. Molded body. 23. The high-strength, lightweight silica airgel molded article according to claim 22, wherein a structure is formed in which closed cells made of 10 to 18 polyhedrons with rounded corners are incorporated. 24. The molded article of high-strength lightweight silica airgel according to claim 22, wherein the thickness of the cured film formed by forming the continuous phase is in the range of 0.1 to 10 μm. 25. An apparent density of 0.1 to 0.5 g / c.
high strength lightweight silica airgel molded body according to any one of claims 22 to 24, characterized in that the range of m ^3. 26. The non-permeable material according to any one of claims 22 to 24, wherein a sealer composition and / or a coating composition is applied to one surface, and one surface is decoratively coated and has a water-impermeable property. High-strength lightweight silica airgel molded body. 27. The sealer composition is at least one selected from the group consisting of a solution or emulsion composition containing a silicon or fluorine compound, an acrylic resin composition, a urethane composition and an epoxy resin composition. The high-strength lightweight silica airgel molded body according to claim 26, characterized in that: 28. A coating composition comprising at least one selected from the group consisting of a solution or emulsion composition containing a silicon or fluorine compound, an acrylic resin composition, a urethane composition and an epoxy resin composition. The high-strength lightweight silica airgel molded body according to claim 26, characterized in that: