JP2001278938A - Rigid polyurethane foam and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rigid polyurethane foam having an excellent properties by improving dimensional stability on the foam structure at high temperature and high humidity. SOLUTION: The rigid polyurethane foam is manufactured by using a mixture of a polyether polyol A-1, which has 200-600 mgKOH/g hydroxy value, is obtained from an active hydrogen compound and an alkylene oxide and has the structure derived from the alkylene oxide based on butylene oxide by 20-100 mol.% and a polyether polyol A-2 different from the A-1, which has 200-600 mgKOH/g hydroxy value, and is obtained from an active hydrogen compound having an aromatic substituent and a nitrogen atom and an alkylene oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a rigid polyurethane foam and a method for producing the same. More specifically, the present invention relates to a good rigid polyurethane foam widely used as a heat insulating material or a heat insulating structural material of a refrigerator, a freezer, a heat insulating panel, a ship or a vehicle, and a method for producing the same.

[0002]

2. Description of the Related Art Rigid polyurethane foams are widely used as heat insulating materials and structural materials for buildings, refrigerators, etc. because of their excellent heat insulating properties. The production method also uses a polyol and an organic polyisocyanate as a blowing agent, a catalyst if necessary,
It can be easily produced with a foam stabilizer, other auxiliaries and the like. In particular, it can be formed in a manufacturing plant or on-site as needed, and its application range is very wide.

However, as a foaming agent for a rigid polyurethane foam, freon has been mainly used as a foaming agent, and it has been completely abolished by compounds due to recent efforts to address environmental issues. In some cases, future use regulations are being determined or considered.

Cyclopentane as a substitute for CFCs,
Techniques using a hydrocarbon compound such as n-pentane as a foaming agent have also been proposed, but these foaming agents have flammability, and it is necessary to take strict explosion-proof measures when manufacturing a rigid polyurethane foam, The work becomes complicated and the cost is further increased.

When water, which has been conventionally used as a subfoaming agent, is used alone, it is necessary to increase the finished density (molding density) at the time of molding in order to maintain the dimensional change, particularly the dimensional change at high temperature and high humidity. Therefore, further weight reduction has been desired. As a countermeasure against this, there is known a method of achieving weight reduction by adding polyethylene fine powder and polybutadiene as anti-shrink agents, respectively, but they have a closed cell ratio of about 50% or less. For this reason, it has been desired to further improve the thermal conductivity and impart flame retardancy. These anti-shrinkage agents are mainly composed of polyols, catalysts, foam stabilizers,
It is used by mixing with the A component containing a foaming agent and other auxiliaries. In this case, the A component separates and becomes cloudy and cannot be stored for a long time as a prepared raw material. And the work was complicated.

[0006]

SUMMARY OF THE INVENTION Explosion-proof equipment and the like can be easily manufactured without the need for explosion-proof equipment at the time of manufacture, and even when only water is used as a foaming agent suitable for environmental measures, the closed cell rate is high.
A method for producing a rigid polyurethane foam having extremely excellent dimensional stability and a rigid polyurethane foam without using a special anti-shrinkage agent which deteriorates the storage stability of the component A including a Polio catalyst, a foam stabilizer and a foaming agent are desired. ing.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, by using a specific polyol composition, it is possible to reduce the weight without using fluorocarbons. The present inventors have found that a novel rigid polyurethane foam having a high closed cell ratio and excellent dimensional stability can be produced, and have completed the invention.

That is, the following (1) to (11) are provided. (1) In a method for producing a rigid polyurethane foam from an organic polyisocyanate, a polyol, and water,
(A-1) A polyether polyol obtained from an active hydrogen compound and an alkylene oxide, wherein 20 to 100 mol% of the skeleton derived from the alkylene oxide is derived from butylene oxide.
H / g polyether polyol, (A-2) hydroxyl value obtained from an active hydrogen compound containing an aromatic substituent and a nitrogen atom, and an alkylene oxide of 200 to 600 mg KO
A method for producing a rigid polyurethane foam produced using a mixed polyol composed of a polyether polyol different from H / g (A-1). (2) (A-1) in the mixed polyol is 20 to 8
The method for producing a rigid polyurethane foam according to (1), wherein the amount is 0% by mass. (3) (A-2) in the mixed polyol is 20 to 8
The method for producing a rigid polyurethane foam according to (1), wherein the amount is 0% by mass. (4) The method for producing a rigid polyurethane foam according to any one of (1) to (3), wherein the content of the mixed polyol in the polyol is 40% by mass or more. (5) wherein (A-1) is pentaerythritol, α-
The method for producing a rigid polyurethane foam according to any one of (1) to (4), which is a polyoxyalkylene polyether polyol produced using at least one of methyl glycosides as an active hydrogen compound.

(6) A polyoxyalkylene polyether polyol characterized in that the active hydrogen compound (A-2) is produced using at least one of tolylenediamine and polyphenylmethane polyamine. (4) The method for producing a rigid polyurethane foam according to (4). (7) The method for producing a rigid polyurethane foam according to (1) to (6), wherein 3.0 to 10 parts by weight of water is used per 100 parts by weight of the total polyol. (8) A rigid polyurethane foam having a closed cell ratio of 70% or more produced by the production method according to (1) to (7). (9) A rigid polyurethane foam having a closed cell ratio of 70% or more and a wet heat dimensional change within a range of 3% to -3%, which can be produced by the production method according to any one of (1) to (7). (10) The closed cell rate exceeds 80%, the dimensional change in wet heat is in the range of 3% to -3%, and the ratio of urea bond to urethane bond (urea bond / urethane bond) is 0.16 or more. A rigid polyurethane foam having a range of 56 or less. (11) The rigid polyurethane foam according to (10), wherein the molding density is 30 or more and 60 kg / m ³ or less.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The rigid polyurethane foam of the present invention can be produced from an organic polyisocyanate and a polyol, if necessary, from a blowing agent, a catalyst, a foam stabilizer, and other auxiliaries. Excellent in nature. In particular, by using a specific mixed polyol, a rigid polyurethane foam having a high closed cell ratio and excellent dimensional stability can be produced. Hereinafter, first, each component used in the production will be described in detail.

[Polyol] The polyol used in the present invention contains at least a specific polyol mixture. All of the polyols may be mixed polyols described below or may contain other polyol compounds. When other polyols are contained, the specific mixed polyol in the polyol is preferably contained in an amount of 40% by mass or more, more preferably 50% by mass or more, and particularly preferably 60% by mass or more. These preferably have a functional group number of 2 or more and 8 or less, more preferably 3 or more and 6 or less, and more preferably 3.5 or more and 5 or less.

The specific mixed polyol is (A-1) a polyether polyol obtained from an active hydrogen compound and an alkylene oxide, wherein 20 to 100 mol% of the skeleton derived from the alkylene oxide is derived from butylene oxide. (A-2) a polyether polyol having a hydroxyl value of 200 to 600 mg KOH / g obtained from an active hydrogen compound containing an aromatic substituent and a nitrogen atom and an alkylene oxide;
This is a polyol composition comprising a polyether polyol different from 1).

(A-1) is 20 to 80 in the polyol.
% By mass, more preferably from 30 to 80% by mass, and particularly preferably from 40 to 80% by mass. By setting (A-1) to be 20% by mass or more of the total polyol, the dimensional stability at high temperature and high humidity of the rigid polyurethane foam is further improved. (A-1) in all polyols is 80%.
When the content is not more than mass%, compatibility with the polyisocyanate is improved, which is preferable.

(A-2) is 20 to 8 in the polyol.
It is preferably 0% by mass, more preferably 30 to 80% by mass, and particularly preferably 40 to 80% by mass. By setting (A-2) to 20% by mass or more, the dimensional stability at high temperature and high humidity is further improved, and by setting it to 80% by mass or less, the reactivity with the polyisocyanate can be set to a suitable range. The resulting foam properties are improved.

<(A-1) Polyether polyol> The polyether polyol (A-1) used in the mixed polyol of the present invention (sometimes referred to as polyoxyalkylene polyether polyol or polyoxyalkylene polyol). Is a polyether polyol obtained from an active hydrogen compound and an alkylene oxide, wherein 20 to 100 mol% of the skeleton derived from alkylene oxide is a skeleton derived from butylene oxide.
It is a polyether polyol of 00 to 600 mgKOH / g.

In the skeleton derived from the alkylene oxide (A-1), the content of the skeleton derived from butylene oxide is preferably from 40 to 100 mol%, particularly preferably from 60 to 100 mol%. When the amount of the added butylene oxide is 20 mol% or more of the total added alkylene oxide, the dimensional stability at high temperature and high humidity of the obtained rigid polyurethane foam is further improved.

By setting the hydroxyl value of the polyether polyol (A-1) to 200 mgKOH / g or more, the rigid polyurethane foam can remarkably improve the dimensional stability. Also, by setting the hydroxyl value to 600 mgKOH / g or less,
The amount of expensive polyisocyanate used can be reduced. In addition, since the amount of the polyisocyanate used can be reduced, for example, a foaming machine of a current production line can be used as it is. Hydroxyl value is 250 to 550
mgKOH / g is more preferable, and 300 to 500 mgKOH / g is particularly preferable.

<Method for Producing (A-1) Polyether Polyol> The synthesis of (A-1) is not particularly limited, as long as it is a synthesis condition of a polyether polyol that can be used for polyurethane.

As a specific synthesis example, a polyether polyol which is an oligomer or a polymer is synthesized by ring-opening polymerization of an alkylene oxide. At least 2 per molecule
A method of ring-opening polymerizing an alkylene oxide using an active hydrogen compound having one active hydrogen as an initiator has been widely used, and is produced in the presence of a catalyst or the like as necessary. In producing the polyoxyalkylene polyol, the initiator and the alkylene oxide may be used alone or in combination of two or more.

As a catalyst for producing a polyether polyol, an alkali metal catalyst is widely used. When producing using an alkali metal catalyst, the reaction temperature is usually 60 to 160 ° C., and the reaction pressure is 0.5 to 6 kg / cm.
Is a ² G.

Although any method may be used as long as the skeleton derived from butylene oxide in (A-1) can be adjusted to a predetermined amount, the content of butylene oxide in the alkylene oxide usually used in the synthesis of polyether polyols may be used. It can be produced by adjusting the amount to 20 to 100 mol%, preferably 40 to 100 mol%, particularly preferably 60 to 100 mol%.

(Alkali metal catalyst) As the alkali metal catalyst, potassium hydroxide, sodium hydroxide, cesium hydroxide and the like can be used.

(Alkylene oxide) Examples of the alkylene oxide used in combination with butylene oxide include propylene oxide, ethylene oxide, and styrene oxide. Among them, it is preferable to use propylene oxide in combination.

(Initiator: Active Hydrogen Compound) The initiator used in the present invention is a compound having two active hydrogen groups in one molecule and a compound to which an alkylene oxide can be added. There is no limitation and any can be used.

Generally, active hydrogen compounds include an active hydrogen compound having an active hydrogen atom on an oxygen atom, an active hydrogen compound having an active hydrogen atom on a nitrogen atom, and an active hydrogen compound having an active hydrogen atom on a sulfur atom. And the like.

(Active hydrogen compound having an active hydrogen atom on an oxygen atom) Examples of the active hydrogen compound having an active hydrogen atom on an oxygen atom include aliphatic polyols, alicyclic polyols, aromatic polyols, and aliphatic polyols. As polyols, ethylene glycol, propylene glycol,
Examples thereof include 1,4-butanediol, 1,6-hexane glycol, glycerin, trimethylolpropane, pentaerythritol, and sorbitol.

The alicyclic polyols include α-methyl glycoside, sucrose and the like. Examples of the aromatic polyols include bisphenol A and bisphenol F.

(Active hydrogen compound having an active hydrogen atom on a nitrogen atom) Any active hydrogen compound having an active hydrogen atom on a nitrogen atom may be used, but a compound having a primary or secondary amino group is preferable. Specific examples include aliphatic amines, cyclic amines, aromatic amines, and alkanolamines. Examples of the aliphatic amine include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

Examples of cyclic amines include piperazine. Examples of the aromatic amines include toluenediamine, phenylenediamine, diaminodiphenylmethane and the like.

Examples of the alkanolamines include monoethanolamine, diethanolamine, triethanolamine, and isopropanolamine.

(Active Hydrogen Compound Having Active Hydrogen Atom on Sulfur Atom) An active hydrogen compound containing an SH group such as thioglycol is exemplified.

(Preferred Active Hydrogen Compound) (A-1) It is preferable to use pentaerythritol and α-methyl glycoside from the viewpoint of the performance of polyether polyol and the ease of handling such as viscosity.

<(A-2) Polyether polyol> As the (A-2) polyether polyol used in the present invention, a hydroxyl value obtained from an active hydrogen compound containing an aromatic substituent, a nitrogen atom, and an alkylene oxide is used. 2
It is a polyether polyol of 00 to 600 mgKOH / g, which is different from (A-1). The hydroxyl value of (A-2) is 3
More preferred is from 00 to 500 mg KOH / g.

<Production Method of (A-2) Polyether Polyol> The synthesis of (A-2) essentially requires an active hydrogen compound containing an aromatic substituent and a nitrogen atom, and can be used for polyurethane. Any conditions may be used for the synthesis of the ether polyol, and there is no particular limitation. The method for synthesizing them is not particularly limited, and (A-1) and (A-2) may be carried out by different methods, for example, using different catalysts, production conditions and the like, or may be carried out in the same manner. .

As a specific synthesis example, a polyether polyol which is an oligomer or a polymer is synthesized by ring-opening polymerization of an alkylene oxide. BACKGROUND ART A method for ring-opening polymerization of an alkylene oxide using an active hydrogen compound having at least two active hydrogens in one molecule as an initiator has been widely used, and is produced in the presence of a catalyst or the like as necessary. An active hydrogen compound containing an aromatic substituent and a nitrogen atom is essential as an initiator. In addition, as the initiator, in addition to the active hydrogen compound containing an aromatic substituent and a nitrogen atom, other active hydrogen compounds, such as the active hydrogen compound described as the initiator of (A-1), can be used in combination. In producing the polyoxyalkylene polyol, the initiator and the alkylene oxide may be used alone or in combination.

As a catalyst for producing a polyether polyol, an alkali metal catalyst is widely used. When producing using an alkali metal catalyst, the reaction temperature is usually 60 to 160 ° C., and the reaction pressure is 0.5 to 6 kg / cm.
Is a ² G.

(Initiator: Active hydrogen compound containing an aromatic substituent and a nitrogen atom) The active hydrogen compound containing an aromatic substituent and a nitrogen atom used in the production of (A-2) includes aromatic N , N- and N, N'-dialkyl-substituted diamines such as 2,3-, 3,4-, 2,4-, 2,6
-Tolylenediamine, 4,4'-, 2,4'-, 2,
At least one selected from 2'-diaminodiphenylmethane and polyphenylmethanepolyamine is used. These may be used in combination. Of these, tolylenediamine and polyphenylmethanepolyamine are preferred.

(Alkylene oxide) Examples of the alkylene oxide used in the production of (A-2) include ethylene oxide, propylene oxide, butylene oxide, and styrene oxide. Among them, it is preferable to use propylene oxide in combination.

<Other Polyols> Polyols other than the above-mentioned specific polyether polyols, that is, polyols other than (A-1) and (A-2) can be used as needed as long as the effects of the present invention are not impaired. Other polyols are not particularly limited as long as they are different from (A-1) and (A-2), but have a hydroxyl value of 200 to 60.
Preferably, it is 0 mgKOH / g.

In the present invention, a polyester polyol comprising an aliphatic polybasic acid, an aromatic polybasic acid or an anhydride thereof and a polyhydric alcohol can also be used. Examples of the aliphatic polybasic acids and anhydrides thereof include oxalic acid, malonic acid, adipic acid, succinic acid, and succinic anhydride. Examples of the aromatic polybasic acid and its anhydride include terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, and pyromellitic anhydride. The polyhydric alcohols are bifunctional to octafunctional and include, for example, ethylene glycol, propylene glycol, butanediol,
Examples thereof include propanediol, diethylene glycol, trimethylpentaneditol, glycerin, pentaneddiol, sorbitol, and sucrose. Alkylene oxide adducts of these alcohols can also be used.

A product obtained by thermally decomposing polyalkylene terephthalate or its residue in a polyol or polycaprolactone copolyester polyol can also be used.
The proportion used is 0 to 60 parts by weight in the polyol (here, the total of the components (A-1) and (A-2) and the other polyol compounds is 100 parts by weight). It is preferably from 0 to 50 parts by weight, particularly preferably from 0 to 4 parts by weight.
0 parts by weight.

[Organic polyisocyanate] The polyisocyanate in the present invention is a compound having at least two isocyanate groups. As the polyisocyanate used in the present invention, any polyisocyanate that can be used as a rigid polyurethane foam can be used. Specifically, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI),
2,4-toluene diisocyanate (2,4-TD
I), 2,6-toluene diisocyanate (2,6-T
DI) and their dimers, trimers or multimers, or mixtures thereof, referred to as crude TDI, crude MDI, and mixtures thereof. Further, an isocyanate prepolymer which is a reaction product of the above isocyanate and an active hydrogen compound is also included.

The amount of the polyisocyanate to be used with respect to the polyol is almost the same as in the case of ordinary rigid polyurethane foam, and the NCO / OH (molar ratio) is preferably 0.8 to 1.6, more preferably 0.9. To 1.5,
Particularly preferably, it is 1.0 to 1.4.

[Blowing agent] Any blowing agent other than chlorofluorocarbon can be used in the present invention. Physical foaming agents, which can be used in combination of multiple foaming agents,
Any of the chemical blowing agents can be used. Water and carbon dioxide are preferred, and water is particularly preferred.

Water as a foaming agent is usually ion-exchanged water,
Distilled water is used, but in some cases, industrial water can be used as it is. The amount of water depends on the total polyol component 1
3.0 to 10 parts by weight can be used per 100 parts by weight, more preferably 4.0 to 10.0, particularly preferably 5.0 to 10.0.

[Urethanization catalyst] Examples of the catalyst used in the present invention include amines, quaternary ammonium compounds, alkali metal salts, tin compounds, phenolate compounds, metal halides, metal complex compounds and the like which are usually used for urethane foaming. Any catalyst that can be used for the urethane can be used.

As amines, trimethylaminoethylpiperazine, triethylamine, tripropylamine,
N-methylmorpholine, N-ethylmorpholine, triethylenediamine, tetramethylhexamethylenediamine, dimethylcyclohexylamine, diazobicycloundecene, 1,3,5-tris (dimethylaminopropyl) hexahydro-s-triazine, and the like. be able to.

As the aziridine, 2-ethylaziridine and the like can be mentioned. Examples of the quaternary ammonium compound include carboxylic acid salts of tertiary amines. As alkali metal salts, potassium octylate,
Sodium acetate and the like can be exemplified. Examples of the lead compound include lead naphthenate and lead octylate.

Examples of the tin compound include dibutyltin diacetate, dibutyltin dilaurate and the like.
Examples of the alcoholate compound include sodium methoxide and sodium ethoxide. Examples of the phenolate compound include potassium phenoxide, lithium phenoxide, and sodium phenoxide.

Examples of the metal halide include iron chloride, zinc chloride, zinc bromide, tin chloride and the like. Examples of the metal complex compound include metal complex compounds such as acetylacetone metal salt. These catalysts can be used alone or in combination of two or more kinds, and the use amount thereof is suitably 0.001 to 15.0 parts by weight based on 100 parts by weight of the polyol.

[Foam stabilizer] As the foam stabilizer, conventionally known silicon-containing organic surfactants are used. A silicone derivative (alkylene oxide-modified polydimethylsiloxane having an alkoxy group or an active OH group at the terminal) is used. Also, so-called nonionic surfactants such as polyoxyethylene octadecylamine and long-chain fatty acid alkylol amide can be used as the foam stabilizer.
For example, SZ-1127, SZ manufactured by Nihon Unica Ltd.
-1142, SZ-1605, SZ-1642, SZ-
1649, SZ-1655, L-580, L-574
0, L-5420, L-5421, etc., SF-2935F, SF- manufactured by Dow Corning Silicone Toray Co., Ltd.
2938F, SF-2940F, SF-2945F, S
F-2908, SRX-294A, SH-190, SH
-192, SH-193, etc., manufactured by Shin-Etsu Chemical Co., Ltd.
-327, F-345, F-305 and the like are suitable.

[Other Additives] In addition, various additives can be added according to the use and purpose. Examples of such additives include a flame retardant, an antioxidant, a colorant, and a viscosity reducing agent.

[Production Method of Rigid Polyurethane Foam] The production method of the rigid polyurethane foam of the present invention comprises the above-mentioned specific mixed polyol or a polyol containing the mixed polyol and an organic polyisocyanate, and if necessary, a foaming agent, a catalyst, and a foam stabilizer. And other additives. As the blowing agent, any of a chemical blowing agent and a physical blowing agent can be produced. Foaming may be carried out in any state, but a method of carrying out foaming inside a mold having a shape or a shape similar to that of a molded product is widely used.

It is preferable that the polyisocyanate and the polyol are mixed immediately before foaming. The other components are generally preliminarily mixed with a polyisocyanate or a polyol in advance, if necessary. The mixture may be used immediately after mixing, or may be stored and used in an appropriate amount. As for the mixing of other components, the combination of the mixing, the mixing order, the storage time after the mixing, and the like can be determined as appropriate.

Among such mixtures, a mixture of a polyol and other components, that is, a polyol and a chemical foaming agent, a foaming agent, a catalyst, and the like, if necessary, a crosslinking agent, a surfactant, a catalyst,
A mixture of a foam stabilizer and other additives may be referred to as a resin premix. These compositions can be appropriately set depending on the required quality of the flexible polyurethane mold foam. This resin premix is reacted with a polyisocyanate.

The polyisocyanate may be unmodified or modified, or a mixture thereof. The viscosity of the resin premix to be used is preferably 2500 mPa · s / 25 ° C. or less from the viewpoints of mixability in a foaming machine and moldability of a foam.

The mixing method may be either dynamic mixing or static mixing, or both may be used in combination. As a mixing method by dynamic mixing, a method of mixing with a stirring blade or the like can be used. Examples of the mixing method by static mixing include a method of mixing in a machine head mixing chamber of a foaming machine, and a method of mixing in a liquid feed pipe using a static mixer or the like. Mixing performed immediately before foaming and mixing of a gaseous component and a liquid component such as a physical foaming agent are performed by static mixing, and mixing of storable components is performed by dynamic mixing. The mixing temperature and pressure can be arbitrarily set according to the quality of the target flexible polyurethane foam, the type and composition of the raw material, and heating can be performed as needed prior to mixing.

Each of the starting components is stirred and mixed at a liquid temperature of 15 to 80 ° C., preferably 20 to 30 ° C., and introduced into an open mold or, optionally, under high pressure, into a temperature-controlled closed mold as required. By doing so, a rigid polyurethane foam can be obtained. Mold temperature is 20 to 110 ° C, preferably 30 to 60 ° C.
C., particularly preferably 45 to 55.degree.

[Rigid polyurethane foam] The rigid polyurethane foam obtained by the present invention has a closed cell ratio of 70%.
That is all. Further, the closed cell ratio can be 70% or more, and the dimensional stability under wet heat can be in the range of 3% to -3%. Further, the closed cell ratio exceeds 80%, and the dimensional stability under wet heat is 3% or more.
It is within the range of 3%, and the ratio of urea bond to urethane bond (urea bond / urethane bond) can be in the range of 0.16 or more and 1.56 or less, more preferably 0.17 or more and 1.25 or less. And particularly preferably 0.19.
The range is not less than 1.04 and not more than 1.04.

There is no particular limitation on how to determine the ratio of the urea bond to the urethane bond (urea bond / urethane bond), but if the weight of each raw material is known, it is convenient to obtain it by the following method. .

[0061]

(Equation 1) (Wherein X ₁ is the weight of the charged polyol (g), X ₁ molecular weight is the average molecular weight of the polyol used, X ₁ is the number of functional groups of the polyol is the average number of functional groups of the polyol used, and X ₂ is the weight of the charged water (g ), X ₂ molecular weight is the molecular weight of water.)

The X ₁ molecular weight can be determined by the number of functional groups of 56.1 * 1000 * X ₁ * hydroxyl value of X ₁ . The unit of the hydroxyl value is mgKOH / g. Satisfies the above physical properties,
A low-density rigid polyurethane foam having a molding density of 30 kg / m ³ or more and 60 kg / m ³ or less can also be used.

The closed cell rate defined in the present invention is
Using a measurement method commonly used for rigid polyurethane foams, namely, an `` pneumatic apparent volume meter ''
It is an apparent volume ratio (%) measured by the method described in ASTM D-2856.

[0064]

The present invention is a rigid polyurethane foam having good dimensional stability at high temperature and high humidity, and can be used at higher temperature and high humidity. Further, by manufacturing using a specific polyol composition, a rigid polyurethane foam having good dimensional stability at high temperature and high humidity can be easily manufactured.

[0065]

EXAMPLES Examples of the present invention will be shown below to clarify aspects of the present invention, but the present invention is not limited to these examples.

(Raw materials used) Polyol A-1-1: pentaerythritol is added with butylene oxide at a reaction temperature of 110 ° C. using potassium hydroxide as a catalyst and has a hydroxyl value of 350 mg KOH.
/ G polyol. Polyol A-1-2: a polyol having a hydroxyl value of 350 mgKOH / g obtained by adding butylene oxide and propylene oxide in a 1: 1 molar ratio at a reaction temperature of 110 ° C. with pentaerythritol using potassium hydroxide as a catalyst. Polyol A-1-3: a polyol having a hydroxyl value of 350 mgKOH / g obtained by adding butylene oxide and propylene oxide at a reaction temperature of 110 ° C. and a molar ratio of 25:75 to pentaerythritol using potassium hydroxide as a catalyst. Polyol A-1-4; having a hydroxyl value of 350 mg KOH obtained by adding butylene oxide at a reaction temperature of 110 ° C. with potassium hydroxide as a catalyst to α-methyl glycoside.
/ G polyol.

Polyol A-2-1: A hydroxyl value of 350 m obtained by adding propylene oxide to a mixture of tolylenediamine and triethanolamine in a 70:30 weight ratio at a reaction temperature of 110 ° C. using potassium hydroxide as a catalyst.
gKOH / g polyol. Polyol A-2-2: A mixture of 4,4'-diaminodiphenylmethane and triethanolamine at a 70:30 weight ratio was reacted with potassium hydroxide as a catalyst at a reaction temperature of 110.
Hydroxyl value obtained by adding propylene oxide at ℃ 3
50 mg KOH / g polyol.

Polyol A-3-1: Reaction temperature of 110 ° C. with pentaerythritol using potassium hydroxide as a catalyst
The hydroxyl value obtained by adding propylene oxide at 3
50 mg KOH / g polyol. Polyol A-3-2; hydroxyl value obtained by adding propylene oxide to α-methyl glycoside at a reaction temperature of 110 ° C. using potassium hydroxide as a catalyst has a hydroxyl value of 350 mg KOH
/ G polyol.

Isocyanate; Cosmonate M-20
0 (Crude polyisocyanate manufactured by Mitsui Chemicals, Inc.)
DI. NCO% = 31.3). Catalyst; 1 (N, made by Kao Corporation)
N, N ', N'-tetramethylhexamethylenediamine). Silicone foam stabilizer; L-5421 (a polydimethylsiloxane derivative manufactured by Nippon Unicar Co., Ltd.). Flame retardant: Filol PCF (Trichlorochlorophosphate TCPP manufactured by Akzo Kashima Co., Ltd.).

(Example 1) The evaluation of foaming was performed as follows. To 100 parts by weight of the polyol, 2 parts by weight of the silicone foam stabilizer, a predetermined amount of water, and a required amount of the catalyst to have a gel time of 85 ± 5 seconds are added to a mixed solution of isocyanate so that the index becomes 110. (Prescription is in gram units in Table 1), and mixed at 6000 rpm for about 6 seconds using a high-speed rotating lab stirrer at a liquid temperature of 25 ° C.
It was quickly placed in a wooden box of cm × 20 cm × 20 cm and foamed. 15 minutes after the injection, the resin was taken out to obtain a rigid polyurethane foam.

The resulting rigid polyurethane foam was cut into 100 × 100 × 100 mm by a slitter the next day, and the free density (apparent density) inside the foam was measured. Aluminum horizontal panels (size: 50 ° C)
Panel foaming was performed using 15 * 60 * 9 cm). At this time, the mixture was injected to a molding density of 35 kg / m ^3, and was taken out 12 minutes after the injection to obtain a panel foam.

The rigid polyurethane foam obtained was cut into a core of 90 × 90 × 40 mm by a slitter the next day, and the cut foam was subjected to a temperature of 70 ° C. and a humidity of 9 mm.
The sample was allowed to stand for 48 hours in an oven set at 5% RH to measure the dimensional change in wet heat (maximum%). The humid heat dimensional change rate was expressed by the maximum value of the total of three places, that is, both ends and the center part, in%.

Further, panel foaming was performed using an aluminum horizontal panel (size: 33 × 33 × 8 cm) adjusted to 50 ° C. At this time, the molding density was 35 kg / m ³
, And taken out 12 minutes after the injection to obtain a panel foam. The core part of the obtained rigid polyurethane foam was slit in the next day to 200 × 200 × 25 mm.
And cut these cut forms into Anacon,
The thermal conductivity was measured with a model TCA-8. The results are shown in Table 1.

(Examples 2 to 8) Free foam and panel foam were evaluated in the same manner as in Example 1 except that the formulations were as shown in Table 1. Table 1 shows the results.

[0075]

[Table 1]

(Comparative Examples 1 to 3) Free foam and panel foam were evaluated in the same manner as in Example 1 except that the formulations were as shown in Table 2. Table 2 shows the results.

[0077]

[Table 2]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadashi Yamamoto 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Chemical Co., Ltd. (72) Inventor Seiji 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Chemicals Inc. (72) Inventor Masaaki Shibata 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside of Mitsui Chemicals Co., Ltd. (72) Inventor Hiroshi Fujino 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture F-term in Mitsui Chemicals, Inc. AA14 4J034 BA03 BA07 DA01 DB03 DG05 DG22 HA01 HA07 HC12 HC61 HC64 HC67 HC71 NA03 QC01

Claims (11)

[Claims] An organic polyisocyanate, a polyol,
A method for producing a rigid polyurethane foam from water, wherein (A-1) a polyether polyol obtained from an active hydrogen compound and an alkylene oxide, wherein 20 to 100 mol% of the skeleton derived from the alkylene oxide is derived from butylene oxide. Price 200 to 600
mgKOH / g polyether polyol, (A-2) hydroxyl value obtained from an active hydrogen compound containing an aromatic substituent and a nitrogen atom, and an alkylene oxide of 200 to 600.
A method for producing a rigid polyurethane foam, which is produced using a mixed polyol composed of a polyether polyol different from (A-1) in mgKOH / g. 2. The method according to claim 2, wherein (A-1) in the mixed polyol is 20 or more.
The method for producing a rigid polyurethane foam according to claim 1, wherein the amount is from 80 to 80% by mass. 3. The method according to claim 1, wherein (A-2) in the mixed polyol is 20 or more.
The method for producing a rigid polyurethane foam according to claim 1, wherein the amount is from 80 to 80% by mass. 4. The method according to claim 1, wherein the content of the mixed polyol in the polyol is 40% by mass or more.
4. The method for producing a rigid polyurethane foam according to any one of items 3 to 3. 5. The method according to claim 1, wherein (A-1) is a polyoxyalkylene polyether polyol produced using at least one of pentaerythritol and α-methyl glycoside as an active hydrogen compound.
5. The method for producing a rigid polyurethane foam according to any one of items 4 to 4. 6. The polyoxyalkylene polyether polyol according to claim 1, wherein the active hydrogen compound (A-2) is produced using at least one of tolylenediamine and polyphenylmethanepolyamine. 5. The method for producing a rigid polyurethane foam according to 4. 7. The process for producing a rigid polyurethane foam according to claim 1, wherein 3.0 to 10 parts by weight of water is used per 100 parts by weight of the total polyol. 8. A rigid polyurethane foam having a closed cell ratio of 70% or more, produced by the production method according to claim 1. 9. A rigid polyurethane foam characterized by having a closed cell ratio of at least 70% and a dimensional change of wet heat within a range of 3% to -3%, which can be produced by the production method according to claim 1. . 10. The closed-cell rate exceeds 80%, the dimensional change in wet heat is in the range of 3% to -3%, and the ratio of urea bonds to urethane bonds (urea bonds / urethane bonds) is 0.1.
A rigid polyurethane foam having a range of 6 to 1.56. 11. The rigid polyurethane foam according to claim 10, wherein the molding density is 30 or more and 60 kg / m ³ or less.