JPH10245543A - Two-package sealant composition for siding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-package sealant for siding, which shows excellent adhesiveness even to an unprimed siding material. SOLUTION: This composition comprises a polymer having at least two thiol groups in the molecule and having a number-average molecular weight of 600-200,000, a polyisocyanate compound having at least two isocyanate group in the molecule and having a ratio of the number-average molecular weight to the number of the isocyanate groups of 600 or above and an adhesion promoter being a polyisocyanate compound having at least two isocyanate groups in the molecule and having a ratio of the number-average molecular weight to the number of the isocyanate groups of below 600.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-component siding sealing material, and more particularly to a two-component siding sealing material having excellent adhesion even without the application of a primer to the siding material.

[0002]

2. Description of the Related Art A polymer containing two or more thiol groups in a molecule is easily cured when mixed with an oxidizing agent, and the thiol group is easily reacted with an epoxy group, an isocyanate group and the like to increase the molecular weight. Therefore, it is widely used for sealing materials, paints and adhesives.

Examples of such a thiol group-containing polymer include a polysulfide polymer described in US Pat. No. 2,466,963 and a polysulfide polyether polymer described in JP-A-4-363325.

In Japanese Patent Application Laid-Open No. 52-125563, the above-mentioned polysulfide polymer is used.
No. 121 proposes a curable composition suitable for a sealing material, which is obtained by curing the polysulfide polyether polymer with an isocyanate compound, has less foaming, has good weather resistance, and can easily obtain a white cured product. Was done.

[0005]

However, when these thiol group-containing polymers and compounds having two or more isocyanate groups in the molecule are used as sealing materials for siding materials, without applying a primer, However, there has been a problem that the interface is separated due to expansion and contraction of the siding material.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a two-component siding sealing material having excellent adhesiveness to a siding material without application of a primer.

[0007]

As a result of intensive studies in view of the above-mentioned object, the present inventors have found that when a specific polyisocyanate compound is used as an adhesion-imparting agent, excellent adhesion to a siding material can be obtained without applying a primer. The present inventors have found that a two-component siding sealing material having the same can be obtained, and have reached the present invention.

That is, the present invention relates to (a) a polymer having two or more thiol groups in a molecule, and (b) a polymer having two or more isocyanate groups in a molecule, wherein the ratio between the number average molecular weight and the isocyanate group is A polyisocyanate compound having a molecular weight of at least 600 and a polyisocyanate compound having at least two isocyanate groups in the molecule and having a ratio of the number average molecular weight to the isocyanate group of less than 600 as an adhesion promoter (c). And a two-component sealing material composition for siding.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [1] Polymer having two or more thiol groups in a molecule Polymer having two or more thiol groups in a molecule used in the present invention (hereinafter, simply referred to as thiol group-containing polymer)
The polymer skeleton portion of polyether, polythioether, polyester, acrylic copolymer, urethane copolymer, polyacetal, polybutadiene, polyisoprene, polyolefin, polychloroprene, polysulfide and those having the structure of these copolymers are preferable. . Particularly, a polysulfide polymer having a polysulfide structure and a polysulfide polyether polymer are preferable. The position of the thiol group is not particularly limited, but is preferably located at the end of the molecular skeleton. (1) polysulfide polymer polysulfide polymer, in the main chain, _{(b) - (C 2 H 4 OC} n H 2 n OC 2 H 4 -
S _x )-(where n is an integer of 1 to 2, x is an integer of 1 to 5), and (b) -C ₂ H _{4 OC n H 2 n OC 2} H 4 -S
H (where n is an integer of 1 to 2). Such a polysulfide polymer has fluidity at room temperature and has a number average molecular weight (Mn).
Is usually 100 to 200,000, preferably 4
00 to 50,000. Preferred examples of such polysulfide polymers are described in U.S. Pat. No. 2,466,96.
No. 3. (2) polysulfide polyether polymer polysulfide polyether polymer, in the main chain ^{(c) - (R 1 O) m} - ( where, ^{R 1} is an alkylene group having 2 to 4 carbon atoms, m is 6
Shows an integer of ~ 200. A polyether moiety represented by), _{(d) - (C 2 H 4 OC} n H 2 n OC 2 H 4 -
S _x ) — and — (CH ₂ CH (OH) CH ₂ —S _x ) — (where n is an integer of 1 to 2 and x is an integer of 1 to 5) contains the door and the end, _{(e) -C 2 H 4 OC n H} 2 n OC 2 H 4 -S
H and / or _{-CH 2 CH (OH) CH 2} -SH ( where, n is an integer of 1-2.) Are those having a thiol group represented by.

In this polysulfide polyether polymer, the polyether portion of (c) and the structural unit of (d) may be bonded in an arbitrary sequence, and the ratio thereof is-(R ¹ O ) M-component is 2 to 9
5 _{wt%, - (C 2 H 4} OC n H 2 n OC 2 H 4
-S _x )-component is 3 to 70% by weight, and-(CH ₂ CH)
It is preferable that the content of the (OH) CH ₂ —S _x ) — component is 1 to 50% by weight. The content of the polysulfide-bonded _Sx is preferably 1 to 60% by weight.

The number average molecular weight (Mn) of the polysulfide polyether polymer is usually from 600 to 200,0.
00, preferably 800 to 50,000.

Such a polysulfide polyether polymer can be produced, for example, by the method described in JP-A-4-363325. [2] Compound Having Two or More Isocyanate Groups in Molecule A compound having two or more isocyanate groups in a molecule used in the present invention (hereinafter, simply referred to as an isocyanate group-containing compound) includes a number average molecular weight and an isocyanate group. Is a polyisocyanate compound having a ratio of 600 or more, and a urethane prepolymer obtained by reacting an organic polyisocyanate compound with an organic polyisocyanate compound and / or an active hydrogen-containing compound is preferable.

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 a hydroxyl group-terminated polyester, a polyvalent polyalkylene ether, a hydroxyl group-terminated polyurethane polymer, an acrylic polyol obtained by introducing a hydroxyl group into an acrylic copolymer, a hydroxyl group-terminated polybutadiene, a polyvalent polythioether, a polyacetal. Aliphatic polyols, and alkanes including alkylene thiols having two or more SH groups, alkenes and aliphatic thiols, polysulfide polymers having terminal SH groups,
Diamines, including aromatic, aliphatic and heterocyclic diamines, and the like, 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, (b) 2
The molar ratio (isocyanate group (b) / thiol group (a)) of the isocyanate group of the polyisocyanate compound having at least two isocyanate groups to the thiol group in the polymer having the thiol group (a) is 0.3 to 4; 0.0 is preferred. [3] Adhesion-imparting agent The adhesion-imparting agent used in the present invention is a polyisocyanate compound having a number-average molecular weight and an isocyanate group ratio of less than 600, and an organic polyisocyanate compound and / or an active hydrogen-containing compound. Urethane prepolymers obtained by reacting compounds 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-terminated polyesters, polyvalent polyalkylene ethers, hydroxyl-terminated polyurethane polymers, acrylic polyols having hydroxyl groups introduced into acrylic copolymers, hydroxyl-terminated polybutadienes, polyvalent polythioethers, polyacetals, and the like. Aliphatic polyols, and alkanes including alkylene thiols having two or more SH groups, alkenes and aliphatic thiols, polysulfide polymers having terminal SH groups,
Diamines, including aromatic, aliphatic and heterocyclic diamines, and the like, 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 particular, the isocyanate group of the adhesion-imparting agent may be an aliphatic polyisocyanate and / or an alicyclic polyisocyanate and / or an aromatic polyisocyanate represented by the following general formula (provided that R ₁ , R ₂ Has 1 to 1 carbon atoms
3 alkyl groups),

[0021]

Embedded image Obtained by reaction with a compound containing three or more active hydrogens in the molecule and having a number average molecular weight of 1,000 or less,
It is preferable that the polyisocyanate compound has three or more isocyanate groups in the molecule. Specific examples of the polyisocyanate compound having the isocyanate group include xylylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate. Can be

It is particularly preferable that the compound containing three or more active hydrogens in the molecule and having a number average molecular weight of 1,000 or less is polypropylene glycol.

In the present invention, the molar ratio of (c) the isocyanate group of the adhesion-imparting agent to (a) the thiol group in the polymer having a thiol group (isocyanate group (c) / thiol group (a)) Is preferably 0.1 to 1.5. [4] Other Compounds The two-component siding sealing material of the present invention further includes calcium carbonate, talc, clay for the purpose of improving economy, workability when applying the composition, and physical properties after curing. , A filler such as titanium oxide and silica, and a plasticizer.

Further, in order to quickly and surely cure after application, the two-component siding sealing material of the present invention contains a reaction catalyst of thiol group and isocyanate group, and an acidic substance as a curing retarder. can do.

As the reaction catalyst, tertiary amines and organometallic compounds are used.

The tertiary amines include monoamines, diamines, triamines, polyamines, cyclic amines,
There are alcohol amines, ether amines and the like, and specific examples are triethylamine, N, N-dimethylcyclohexylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-. Tetramethylpropane-1,3-diamine, N, N, N ′, N′-tetramethylhexane-1,6-diamine, N, N,
N ', N ", N" -pentamethyldiethylenetriamine, N, N, N', N ", N" -pentamethyldipropylenetriamine, tetramethylguanidine, N, N-dipolyoxyethylenestearylamine, N, N -Dipolyoxyethylene tallow alkylamine, triethylenediamine, N, N'-dimethylpiperazine, N-methyl-
N '-(2 dimethylamino) -ethylpiperazine, N-
Methyl morpholine, N-ethyl morpholine, N- (
N ′, N′-dimethylaminoethyl) -morpholine,
1,2-dimethylimidazole, dimethylaminoethanol, dimethylaminoethoxyethanol, N, N,
N'-trimethylaminoethylethanolamine, N-
Methyl-N ′-(2-hydroxyethyl) -piperazine,
N- (2hydroxyethyl) -morpholine, bis- (2
Dimethylaminoethyl) ether, ethylene glycol bis- (3dimethyl) -aminopropyl ether, and the like. Two or more of these tertiary amines may be used.

The organometallic compound includes an organic tin compound, an organic mercury compound, an organic lead compound and the like. Specifically, tin octylate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate Rate, dibutyltin maleate, dioctyltin mercaptide, dioctyltin thiocarboxylate, phenylmercuric propionate, lead octenoate and the like. Two or more of these organometallic compounds may be used.

As the acidic substance, organic acids such as citric acid, stearic acid and 2-ethylhexanoic acid are preferable.

[0029]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. [Synthesis Example 1] 1,000 g of bifunctional polypropylene glycol (OH value: 56.4 mgKOH / g) obtained by adding propylene oxide to propylene glycol
And 107 g of epichlorohydrin and 1.25 g of stannic chloride pentahydrate were charged into a reaction vessel and stirred at 80 to 90 ° C. for 3 hours. Furthermore, a polysulfide polymer (trade name “Tiocoll LP5” manufactured by Toray Thiokol Co., Ltd.)
5 ″) After adding and mixing 1,110 g, 89.9 g of sodium bisulfide (purity: 72.3%) was added, and the mixture was stirred at 80 ° C. for 2 hours. Thereafter, the salt was removed, and the mercaptan content was changed to 2.10 g.
A pale yellow, transparent polymer having 0% by weight and a viscosity of 80 poise (25 ° C.) was obtained. Example 1 A plasticizer and a filler were added to the polymer of Synthesis Example 1 in the proportions shown in Table 1 to obtain a main ingredient. In 390 parts of the main ingredient,
Polymer obtained by adding xylylene diisocyanate to polypropylene glycol (isocyanate content 4.2%, ratio of number average molecular weight to isocyanate group 1,0
00) 44 parts (isocyanate group (b) / thiol group (a) = 0.73) and a polymer obtained by adding xylylene diisocyanate to trifunctional polypropylene glycol having a molecular weight of 1,000 (isocyanate content 7.
8%, ratio of number average molecular weight to isocyanate group 540) 1
1 part (isocyanate group (c) / thiol group (a) =
0.34).

Using the resulting mixture, a fiber-mixed cement-based siding material was used as an adherend, and a test piece shown in FIG. 1 was prepared using the cut edge surface as a test surface.
A tensile adhesion test was performed on the test specimen after curing for 3 days. The tensile adhesion test was performed in a room at 20 ° C.
The results are shown in Table 2. In addition, it was cohesively broken without applying a primer. Example 2 59 parts of a polymer obtained by adding xylylene diisocyanate to polypropylene glycol (isocyanate content: 4.2%, ratio of number average molecular weight to isocyanate group: 1,000) (isocyanate group (b) / thiol group) (A) = 0.97) and 3 having a molecular weight of 1,000
A polymer obtained by adding xylylene diisocyanate to a functional polypropylene glycol (isocyanate content: 7.8%, ratio of number average molecular weight to isocyanate group: 5)
40) 3 parts (isocyanate group (c) / thiol group (a) = 0.09) were mixed together with the main ingredient blended in the ratio shown in Table 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 2. In this case, 50% cohesive failure and 50% interfacial peeling were performed without applying a primer. Example 3 55 parts of a polymer obtained by adding hexamethylene diisocyanate to polypropylene glycol (isocyanate content: 2.4%, ratio of number average molecular weight to isocyanate group: 1,750) (isocyanate group (b))
/ Thiol group (a) = 0.52) and a molecular weight of 1,000
14 parts of a polymer obtained by adding hexamethylene diisocyanate to trifunctional polypropylene glycol (isocyanate content: 9.4%, ratio of number average molecular weight to isocyanate group: 450) (isocyanate group (c) / thiol group (a)) = 0.52) was mixed with the main ingredient blended in the ratio shown in Table 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 2. In addition, it was cohesively broken without applying a primer. Comparative Example 65 parts of a polymer obtained by adding xylylene diisocyanate to polypropylene glycol (isocyanate content: 4.2%, ratio of number average molecular weight to isocyanate group: 1,000) (isocyanate group (b) / thiol group ( a) = 1.07) was mixed together with the main ingredient blended in the ratio shown in Table 1, and the same evaluation as in Example 1 was performed.
The results are shown in Table 2. In addition, this product was subjected to interfacial peeling without the application of the primer and cohesive failure with the application of the primer.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

As described above, in the present invention, a polymer having two or more thiol groups in a molecule and a polymer having two or more isocyanate groups in a molecule and having a number average molecular weight to isocyanate group ratio of 600 Along with the polyisocyanate compound described above, as an adhesion-imparting agent, a polyisocyanate compound having two or more isocyanate groups in a molecule and having a number average molecular weight and a ratio of isocyanate group of less than 600 contains a polyisocyanate compound. A two-component siding sealing material composition having excellent adhesion can be obtained without the application of a primer.

[Brief description of the drawings]

FIG. 1 shows a test specimen for a tensile adhesion test.

Claims (8)

[Claims] 1. A polymer having (a) a polymer having two or more thiol groups in a molecule and (b) a polymer having two or more isocyanate groups in a molecule and having a number average molecular weight to isocyanate group ratio of 6
And (c) a polyisocyanate compound having two or more isocyanate groups in the molecule and having a number average molecular weight and a ratio of isocyanate group of less than 600 as an adhesion-imparting agent. Siding sealing composition for siding. 2. The two-component siding sealing material composition according to claim 1, wherein the (a) polymer having two or more thiol groups in the molecule has a number average molecular weight of 60.
A sealant composition for two-component siding, which is 0 to 200,000. 3. The sealing material composition for a two-component siding according to claim 1 or 2, wherein the polymer (a) having two or more thiol groups in a molecule is represented by the following formula: _{b) - (C 2 H 4 OC} n H 2 n OC 2 H 4 -
S _x )-(where n is an integer of 1 to 2, x is an integer of 1 to 5), and (b) -C ₂ H _{4 at the terminal OC n H 2 n OC 2 H} 4 -S
A two-component siding sealing material composition, which is a polysulfide polymer having a thiol group represented by H (where n is an integer of 1 to 2). 4. The sealing material composition for a two-component siding according to claim 1 or 2, wherein the polymer (a) having two or more thiol groups in a molecule is represented by the following formula: _{^{c) - (R 1 O) m}} - ( where, ^{R 1} is an alkylene group having 2 to 4 carbon atoms, m is 6
Shows an integer of ~ 200. A polyether moiety represented by), _{(d) - (C 2 H 4 OC} n H 2 n OC 2 H 4 -
S _x ) — and — (CH ₂ CH (OH) CH ₂ —S _x ) — (where n is an integer of 1 to 2 and x is an integer of 1 to 5). containing the unit, and the terminal, _{(e) -C 2 H 4 OC n H} 2 n OC 2 H 4 -S
H and / or a polysulfide polyether polymer having a thiol group represented by —CH ₂ CH (OH) CH ₂ —SH (where n is an integer of 1 to 2). Component type sealing material composition for siding. 5. The sealing material composition for a two-component siding according to claim 1, wherein the isocyanate group of the adhesion promoter (c) is an aliphatic polyisocyanate and / or an alicyclic polyisocyanate. Isocyanate,
And / or an aromatic polyisocyanate represented by the following general formula (where R ₁ and R ₂ are alkyl groups having 1 to 3 carbon atoms)
And Obtained by reaction with a compound containing three or more active hydrogens in the molecule and having a number average molecular weight of 1,000 or less,
A two-component siding sealing material composition comprising a polyisocyanate compound having three or more isocyanate groups in a molecule. 6. The sealant composition for a two-component siding according to claim 5, wherein the number average molecular weight of the (c) adhesion-imparting agent containing three or more active hydrogens in the molecule is 1,000. A sealant composition for a two-component siding, wherein the following compound is polypropylene glycol. 7. The two-component siding sealing material composition according to claim 1, wherein the (b) isocyanate group of a polyisocyanate compound having two or more isocyanate groups in a molecule; Molar ratio to thiol group in polymer having two or more thiol groups in the molecule (isocyanate group (b) / thiol group (a))
Is 0.3 to 4.0, a sealing material composition for two-component siding. 8. The sealing material composition for a two-component siding according to claim 1, wherein (c) an isocyanate group of a polyisocyanate compound of an adhesion-imparting agent;
(A) The molar ratio (isocyanate group (c) / thiol group (a)) to the thiol group in the polymer having two or more thiol groups in the molecule is 0.1 to 1.5. Siding sealing composition for siding.