JPH11279528A - Polysulfide-based sealant composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polysulfide-based sealant composition having a sufficiently long pot life and having a viscosity suitable for handling. SOLUTION: This composition comprises (a) a polysulfide polymer, (b) a compound having at least two isocyanate groups in the molecule, (c) a curing catalyst comprising a tertiary amine and/or an organometallic compound, and (d) surface-treated calcium carbonate prepared by surface-treating calcium carbonate having a nitrogen adsorption specific surface area of 15-30 m<2> /g as measured by the BET method with a surface-treating agent comprising an alkylbenzenesulfonic acid and/or a metal salt thereof and a fatty acid and/or a metal salt thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for a polysulfide-based sealant, and more particularly to a composition having a sufficient pot life and thixotropic content when a curing agent is mixed by using a specific surface-treated calcium carbonate as a filler. The present invention relates to a curable composition capable of giving an object.

[0002]

2. Description of the Related Art A polysulfide-based sealant is composed of a liquid polysulfide as a base polymer, an inorganic filler,
A composition containing a curing agent, a plasticizer, and the like, and exhibits excellent adhesion to all adherends such as aluminum, glass, and concrete due to the strong adhesive force developed by the curing reaction of the polysulfide polymer.

Such polysulfide polymers include, for example, those described in US Pat. No. 2,466,963,
And polysulfide polyether polymers described in JP-A-4-363325.

Further, by curing the polysulfide polymer in JP-A-52-125563 and in JP-A-4-366121, the polysulfide polyether polymer is cured with an isocyanate compound, so that foaming is reduced and good weather resistance is obtained. There has been proposed a composition suitable as a sealant from which a white cured product can be easily obtained.

[0005]

SUMMARY OF THE INVENTION A preparation for a curable composition for curing these polysulfide polymers with an isocyanate compound using a tertiary amine and / or an organometallic catalyst as a catalyst is prepared. In this case, sedimentable calcium carbonate can be used as a filler, but depending on the type, the pot life is often shortened, or thixotropic (thixotropic) is reduced, resulting in poor workability during construction. there were. When the pot life is short, the improvement can be achieved by adding a curing retarder, and when the thixotropy decreases, the improvement can be achieved by adding a viscosity modifier. However, when producing a composition for a sealant, it is not preferable to mix various kinds of additives in addition to a solid filler, since the production process becomes complicated and particularly when the process is carried out on a large scale.

Accordingly, an object of the present invention is to provide a composition for a polysulfide-based sealant which has a sufficient pot life and has a viscosity suitable for handling.

[0007]

Means for Solving the Problems The present inventors have studied to solve the above-mentioned problems, and have found that a polysulfide polymer can be incorporated into a molecule by using a tertiary amine and / or an organometallic catalyst. When preparing a composition for a sealant cured with a compound having two or more isocyanate groups, when calcium carbonate surface-treated with a surface treatment agent is used as a filler, the specific surface area (particle diameter) of calcium carbonate is adjusted. By doing so, it was found that the properties as a composition for a sealant, for example, initial viscosity, thixotropy, and pot life (curing time) could be controlled, and the present invention was completed.

That is, the curable composition of the present invention comprises:
(A) a polysulfide polymer and (b) 2
A compound having at least two isocyanate groups, and (c)
A curing catalyst comprising (1) a tertiary amine and / or (2) an organic metal has a nitrogen adsorption specific surface area of (d) BET method of 15%.
A surface-treated calcium carbonate obtained by subjecting calcium carbonate of up to 30 m ² / g to a surface treatment agent comprising (3) an alkylbenzenesulfonic acid and / or a metal salt thereof and (4) a fatty acid and / or a metal salt thereof; It is a composition for a polysulfide-based sealant characterized by being contained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The sealant composition of the present invention contains a surface-treated calcium carbonate as a filler. 5 parts by weight or more, preferably 10 parts by weight or more, more preferably 50 parts by weight or more, per 100 parts by weight of the polysulfide prepolymer.
0 parts by weight or less, preferably 200 parts by weight or less, more preferably 150 parts by weight or less of surface-treated calcium carbonate is used.

The viscosity of the base material (1 rpm / 25 ° C.) of the composition for a sealant containing the surface-treated calcium carbonate and the polysulfide polymer is 3,000,000 cp or more, preferably 4,000,000 cp.
p or more, more preferably 500000cp or more, 900000cp or less, preferably 800000cp or less, more preferably 700000cp
cp or less, and the initial viscosity (1 rp) after mixing with a compound having two or more isocyanate groups in a molecule as a curing agent.
m / 25 ° C.) is 1,000,000 cp or more, preferably 2,000,000 cp or more, 1,000,000 cp or less, preferably 8,000,000 cp or less, more preferably 6,000,000 cp or less, and the TI value (1 rpm viscosity /
10 rpm viscosity ratio) is 5 or more, preferably 6 or more, and more preferably 6.7 or more, and the workable time at 20 ° C. for 1 hour or more, preferably 2 hours or more, and more preferably 3 hours or more.
By adjusting so as to be not less than time, not more than 6 hours, preferably not more than 5 hours, more preferably not more than 4 hours,
A composition for a sealant that is easy to work as a sealant and has good properties after curing can be obtained.

[1] Surface-treated calcium carbonate Surface-treated calcium carbonate can be produced by mixing calcium carbonate and a surface treatment agent. The calcium carbonate, the nitrogen adsorption specific surface area by BET method of 15 m ² / g or more, 30 m ² / g or less, preferably 25 m ² /
g or less, more preferably 20 m ² / g or less. If calcium carbonate having too large a specific surface area is used, the pot life (curing time) of the composition for a sealant tends to be short, and if too small calcium carbonate is used, the viscosity characteristics (initial viscosity and thixotropic properties) of the composition for a sealant Tends to decrease.

As calcium carbonate, natural products or synthetic products, preferably synthetic products, can be used, for example, as powders. As calcium carbonate, calcium carbonate powder used as a filler for various resins (for example,
Natural raw materials mechanically pulverized or precipitated from an aqueous solution) can be used. In a preferred embodiment, the primary particle size is 10 μm or less, preferably 3 μm or less,
More preferably 0.10μm or less, 0.03μm or more, preferably
Those having a thickness of 0.04 μm or more, more preferably 0.06 μm or more can be used.

The shape of calcium carbonate is cubic,
A spindle shape, a plate shape, a column shape, a whisker shape, a spherical shape and the like are applied.

[2] Surface treatment agent As a surface treatment agent for calcium carbonate, various resin products, for example, various organic compounds used as additives of conventional polysulfide-based sealants, for example, organic compounds having a polar group, Specifically, a sulfonic acid (particularly, a sulfonic acid having 1 to 30 carbon atoms, preferably 10 to 20 carbon atoms) and / or a salt thereof, and a carboxylic acid (particularly, 1 to 30 carbon atoms, preferably
10-20 carboxylic acids) and / or salts thereof.

Alkylbenzenesulfonic acid (for example, alkylbenzenesulfonic acid having 1 to 30 carbon atoms, preferably 10 to 20 carbon atoms, specifically dodecylbenzenesulfonic acid) and / or its salt (for example, alkali metal salt) By using a surface-treated calcium carbonate using an alkaline earth metal salt as a filler, the pot life of the composition for a sealant can be extended, that is, workability can be improved. More preferably, by using an alkylbenzenesulfonic acid and / or a salt thereof in combination with a viscosity modifier as a surface treatment agent, the viscosity characteristics (particularly, the initial viscosity , Thixotropic properties) can be improved to a range where handling is easy.

As the viscosity modifier, a fatty acid (particularly, a fatty acid having 1 to 30 carbon atoms, preferably 10 to 20 carbon atoms) and / or a metal salt thereof is used. As the fatty acid, a saturated or unsaturated fatty acid such as stearic acid, oleic acid and lauric acid can be used. As the metal salt of the fatty acid, an alkali metal salt, an alkaline earth metal salt, an aluminum salt, or the like of the fatty acid can be used. In particular, the viscosity modifier is preferably a fatty acid having a saturated fatty acid content of 80% by weight or more and / or a metal salt thereof. More preferably, the content of stearic acid is 40
% By weight or more of fatty acids and / or metal salts thereof.

The content of the alkylbenzenesulfonic acid and / or a salt thereof is 0.05% by weight or more, preferably 0.1% by weight or more, more preferably 0.5% by weight or more and 5% by weight or less, and more preferably 2% by weight or less. Is 1% by weight
Hereinafter, the content of the fatty acid and / or metal salt thereof as a viscosity modifier is 0.05% by weight or more, preferably 0.1% by weight or more, more preferably 2% by weight or more, 10% by weight or less, preferably 5% by weight or less, More preferably 3% by weight or less, usually the total content of both is 0.1% by weight or more, preferably 1% by weight or more, more preferably 2% by weight or more, 10% by weight or less, preferably 6% by weight or less, More preferably, by using 4% by weight or less of surface-treated calcium carbonate as a filler, a composition for a sealant having excellent properties can be obtained.

[2] Polysulfide Polymer The polysulfide polymer used in the present invention has a reactive mercaptan group (—SH) at the terminal of the molecule.
As the polymer skeleton, a liquid polysulfide polymer having fluidity at room temperature represented by the general formula (A) or (A) and (B) can be used.

-(-R ¹ -S _X- ) _n -R ¹ -S _x (a)-(-R ² -S _X- ) _n -(-R ³ -O-) _n -S _x- (b (X is an integer of 1 to 5, n and m are integers of 2 to 200. R ¹ , R ² and R ³ are divalent organic groups (alkylene group,
Alkylene ether group, hydroxyalkylene group, etc.)
Is shown. Such a polysulfide polymer has fluidity at room temperature and has a number average molecular weight (Mn) of usually 100 to 200,000, preferably 800 to 50,000. Preferred examples of such polysulfide polymers are described in U.S. Pat. No. 2,466,963 and JP-A-4-363325.

[3] Compound Having Two or More Isocyanate Groups in the Molecule The compound used in the present invention containing two or more isocyanate groups in the molecule (hereinafter, simply referred to as an isocyanate group-containing compound) is an organic polyisocyanate compound. Urethane prepolymers obtained by reacting an organic polyisocyanate compound with an active hydrogen-containing compound and / or an active hydrogen-containing compound are preferred.

Specific examples of the organic polyisocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate (crude MDI), xylylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate.

Examples of the active hydrogen-containing compound include hydroxyl group-terminated polyesters, polyvalent polyalkylene ethers, hydroxyl group-terminated polyurethane polymers, and mixtures thereof.

As the urethane prepolymer, those obtained by reacting the above-mentioned active hydrogen-containing compound with an organic polyisocyanate compound under the condition of an excess of isocyanate compound can be used.

In the present invention, the molar ratio (isocyanate group / thiol group) of the isocyanate group in the isocyanate group-containing compound to the thiol group in the thiol group-containing compound is 0.5 to 4.0, preferably 0.7 to 3.0. To mix. If the molar ratio is less than 0.5, the composition does not have a sufficiently high molecular weight, while if it exceeds 4.0, the cured product becomes hard and brittle, which is not preferable.

[4] Tertiary amine, organometallic compound (1) Tertiary amine The tertiary amine in the present invention includes monoamines, diamines, triamines, polyamines, cyclic amines, alcohol amines, ether amines. And so on,
Specific examples include triethylamine, N, N-dimethylcyclohexylamine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethylpropane-
Examples thereof include 1,3-diamine, tetramethylguanidine, N, N-dipolyoxyethylene stearylamine, N, N-dipolyoxyethylene tallowalkylamine, and triethylenediamine. Two or more of these tertiary amines may be used.

(2) Organometallic compounds The organometallic compounds in the present invention include organotin compounds, organomercury compounds, organolead compounds and the like. Specifically, tin octylate, dibutyltin diacetate, dibutyltin dilaurate, Examples thereof include dibutyltin mercaptide, dibutyltin maleate, dioctyltin mercaptide, phenylmercury propionate, and lead octenoate.

Among them, organotin compounds which are less affected by discoloration and the like are preferable. Two or more of these organometallic compounds may be used.

The content of the curing catalyst (c) in the curable composition is preferably from 0.001 to 5 parts by weight, more preferably from 0.005 to 3 parts by weight, per 100 parts by weight of the polymer (a) having a thiol group. Department. If the content is less than 0.001 part by weight, curing does not proceed, and if it exceeds 5 parts by weight, the pot life becomes short, which is not preferable.

[5] Other Compounds The composition for the sealant may contain other additives as necessary. As the additives, for example, fillers other than surface-treated calcium carbonate, plasticizers, pigments, rubber vulcanizing agents, reinforcing agents, adhesion-imparting agents, ultraviolet and ozone deterioration inhibitors and the like, and the like can be used. it can. As the filler other than the surface-treated calcium carbonate, for example, calcium carbonate powder (untreated), calcium bicarbonate powder, quartz powder, alumina, calcium oxide, talc, glass powder, various aggregates and the like can be used. .

[0031]

EXAMPLES Example 1 [Preparation of surface-treated calcium carbonate] Precipitated calcium carbonate powder having a specific surface area of nitrogen of 18 m ² / g by the BET method (particle diameter: 0.1
A surface-treated calcium carbonate having a dodecylbenzenesulfonic acid content of 0.8% by weight and a sodium stearate content of 3.0% by mixing 100 parts by weight of dodecylbenzenesulfonic acid and sodium stearate for surface treatment. A powder was prepared.

[Preparation of composition (base agent) for sealant] Using a planetary mixer, a polysulfide polymer (trade name "thiocol LP-282", manufactured by Toray Thiokol Co., Ltd., mercaptan content 2.0% by weight, viscosity 9100 cp / 25)
100 ° C), 0.5 parts by weight of tin catalyst (trade name “SCAT-4A” manufactured by Sankyoki Gosei Co., Ltd.), 1.5 parts by weight of oleyl alcohol (trade name “Angecol 90N” manufactured by Nippon Rika Co., Ltd.) 2 parts by weight of phosphate ester (trade name "JP-33E" manufactured by Johoku Chemical Co., Ltd.), 13 parts by weight of xylene resin-based plasticizer (trade name "Nicanol LLL" manufactured by Mitsubishi Gas Chemical Industry),
A mixture of 38.7 parts by weight of a phthalic acid-based plasticizer (trade name “DHP” manufactured by Daihachi Chemical Industry Co., Ltd.) was added to a mixture of stearic acid powder and 0.1 parts by weight.
After adding and mixing 5 parts by weight, 128 parts by weight of the surface-treated calcium carbonate powder prepared above, 0.4 part by weight of a vulcanization accelerator (trade name “Noxeller TET” manufactured by Ouchi Shinko Chemical Co., Ltd.) and bicarbonate 105.4 parts by weight of calcium was added, mixed, and defoamed for 10 minutes to prepare a composition for sealant (main agent).

The viscosity of the base material for the sealant is 6400000cp (1r
pm, 25 ° C.), and TI value (viscosity at 1 rpm / 10 viscosity at 10 rpm) is 6.
84.

[Preparation of a cured sealant] 390 parts by weight of a sealant composition (main ingredient) was mixed with an isocyanate curing agent (trade name "CP-132" manufactured by Toray Thiokol Co., Ltd., NCO content: 4.1% by weight, viscosity: 13,000 cp / 25 ° C) 66 parts by weight and colorant 10
It was mixed with parts by weight. Initial viscosity after mixing (1 rpm and 10 rpm
Viscosity / 25 ° C.), and the TI value [1 rpm viscosity / 10 rpm
Was calculated.

The obtained mixture was 35 mm in height and 20 mm in inner diameter.
After pouring into an ethylene cup and smoothing the surface,
While storing in a temperature of 60 ℃ and humidity of 60RH%, measure the penetration every hour using a penetration tester used in JIS K-2207,
The time required to reach 350 was taken as the pot life.

Further, an H-type test piece was prepared by using a mixture according to JIS A-5758 as an adherend using an aluminum plate treated with sulfuric acid alumite using this mixture, and a 50% tensile stress (50% M kgf / cm ² ), 150% tensile stress (150% Mkgf
/ Cm ^2), the maximum tensile stress ^{_{(T m ax kgf / cm 2}} ) and elongation (E
b%) was performed indoors at 20 ° C. Table 1 shows the results.

Example 2 The procedure of Example 1 was repeated except that sodium laurate was used instead of sodium stearate as a surface treatment agent for calcium carbonate. Table 1 shows the results.

Example 3 The procedure of Example 1 was repeated, except that sodium oleate was used instead of sodium stearate as a surface treatment agent for calcium carbonate. Table 1 shows the results.

Comparative Example 1 The procedure of Example 1 was repeated except that the precipitated calcium carbonate powder having a nitrogen adsorption specific surface area of 35 m ² / g by the BET method was used. Table 1 shows the results.

Comparative Example 2 The procedure of Example 1 was repeated except that a precipitated calcium carbonate powder having a nitrogen adsorption specific surface area of 10 m ² / g by the BET method was used. Table 1 shows the results.

Comparative Example 3 The procedure of Example 1 was repeated except that a precipitated calcium carbonate powder having a nitrogen adsorption specific surface area of 18 m ² / g by the BET method was used without surface treatment. Table 1 shows the results.

[0042]

Table 1 Initial viscosity TI value Pot life 50% M 150% M Tmax Eb Break 1 rpm (cp) 1/10 rpm (hour) Situation Example 1 33000 8.3 3.5 14 26 48 590 CF CF Example 2 42000 6.7 1.8 14 25 45 500 CF Example 3 32000 6.0 3.0 16 26 42 460 CF Comparative Example 1 60000 8.6 <1.0 6 10 24 810 AF Comparative Example 2 6000 4.6 3 0.0 19 16 50 710 AF Comparative Example 3 3000 2.0 <1.025 30 60 700 AF 50% M, 150% M, _Tmax : N / cm ² Breaking condition CF: cohesive failure, AF: adhesion failure

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 81/04 C08L 81/04 // C08G 18/16 C08G 18/16 18/52 18/52 (72) Inventor Kazuyuki Hosoi Hyogo 4-78, Motohama-cho, Amagasaki City, Shiroishi Industry Co., Ltd. (72) Inventor Sonosuke Kawasaki 1212 Nakanosato, Fujikawa-cho, Anbara-gun, Shizuoka Prefecture Shiroishi Industry Co., Ltd.

Claims (3)

[Claims] 1. A polysulfide polymer comprising: (a) a polysulfide polymer;
(B) a compound having two or more isocyanate groups in a molecule, and (c) a curing catalyst comprising (1) a tertiary amine and / or (2) an organic metal, and (d) a nitrogen adsorption specific surface area by a BET method. Surface-treated calcium carbonate obtained by subjecting calcium carbonate having a particle size of 15 to 30 m ² / g to a surface treatment agent comprising (3) an alkylbenzenesulfonic acid and / or a metal salt thereof and (4) a fatty acid and / or a metal salt thereof. To
A composition for a polysulfide-based sealant. 2. The polysulfide-based sealant composition according to claim 1, wherein the fatty acid and / or the metal salt thereof has a saturated fatty acid content of at least 80% by weight. Composition for sealant. 3. The composition for a polysulfide-based sealant according to claim 1, wherein said (4) fatty acid and / or
Or the metal salt thereof has a stearic acid content of 40% by weight.
A composition for a polysulfide-based sealant, characterized in that: