JP2002088267A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition which prevents the uncured state of a thin layer particularly when used as the construction sealing medium to effect the thin layer application, i.e., which has excellent curability of thin layer portions. SOLUTION: The curable composition comprises a hydrolyzable silyl group- containing polymer as the major compound and at least one combination of curable catalysts each to be selected from at least two different groups out of the three groups of divalent organotin compounds, tetravalent organotin compounds, and organobismuth compounds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable composition, and more particularly, to a curable composition containing a hydrolyzable silyl group-containing polymer as a main component and a curing catalyst comprising a specific combination. The present invention relates to a curable composition having excellent curability of a thin layer portion even when a thin layer is formed.

[0002]

2. Description of the Related Art Curable compositions containing a hydrolyzable silyl group-containing polymer as a main component form a cured product by moisture-curing the main component polymer. Used for wood. Thus, when this kind of composition is applied to a building sealing material requiring particularly high durability, for example, a divalent organotin compound is used as a curing catalyst, and if necessary, a basic substance is used as a promoter. Attempts have generally been made to improve the elastic recovery rate and impart toughness by using a combination of these (for example, see JP-B-61-60867). However, it is 60-9 on the sunlit wall in summer.
When it is applied to a high-temperature coated object (such as a metal panel) which has a temperature of 0 ° C. or higher and has thus accumulated heat, it has a thickness of 0.
It was found that a phenomenon referred to as so-called thin-layer uncured occurred at a casting portion (thin-layer portion) of 1 mm or less.

According to the knowledge of the present inventors, such a phenomenon is caused by the fact that the metal panel has reached a high temperature, and as a result, the sealing material in the thin layer portion is exposed to a high temperature. Divalent organotin compounds are susceptible to oxidation and the like, causing self-condensation in the process of conversion to the more stable tin (IV), which causes catalyst deactivation; This is presumed to be caused by the loss of the cocatalyst function due to the easy formation of a carbonate by the neutralization reaction with. For example, a thin layer uncured often occurs at an application site such as a joint seal of a metal panel or a seal around a glass window. On the other hand, in a relatively thick portion, the inside that does not come into contact with the high-temperature portion is free from the above-mentioned catalyst deactivation, so that the catalyst is sequentially supplied from the inside, so that the uncured phenomenon may not occur. . As described above, when a thin layer is constructed at a high temperature in the summer, uncured phenomena occur frequently, so that dust adheres to the uncured portion on the outer wall of the building, and the dust flows out due to rainfall or the uncured portion itself. There was a problem that the outside wall of the building was contaminated by the outflow of water.

[0004]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and found that a divalent organotin compound and a tetravalent organotin compound and / or an organic bismuth compound were used in combination. Or the combination of a tetravalent organic compound and an organic bismuth compound can prevent the above-described uncured thin layer portion without impairing the elastic recovery rate and toughness, and completed the present invention. It led to.

That is, the present invention provides a curable composition containing a hydrolyzable silyl group-containing polymer as a main component.
And a curing catalyst comprising a combination of at least one selected from at least two of at least two groups among three groups of a trivalent organotin compound, a tetravalent organotin compound, and an organic bismuth compound. An object of the present invention is to provide a curable composition having excellent curability of a layer portion.

The hydrolyzable silyl group-containing polymer used in the present invention includes so-called modified silicone polymers, alkoxysilyl group-containing isobutylene polymers, hydrolyzable silyl group-containing polyesters, and alkoxysilyl group-containing acrylic polymers. . The modified silicone polymer is a liquid polymer having a polyoxyalkylene ether as a main chain skeleton and having a silyl group having a hydrolyzable group (for example, a hydroxyl group, a halogen group, an alkoxy group, or a mercapto group) at a terminal or a side chain. It is preferable to use those having a main chain of polyoxypropylene ether and a molecular weight of 8,000 to 30,000.

The above-mentioned alkoxysilyl group-containing isobutylene-based polymer (hereinafter simply referred to as isobutylene-based polymer) has a main chain skeleton composed of at least an isobutylene unit [if necessary, other than an isobutylene unit, a monomer which can be copolymerized with isobutylene]. Units (e.g., olefins having 4 to 12 carbon atoms, vinyl ethers, aromatic vinyl compounds, vinyl silanes, allyl silanes, and the like).

Embedded image [Wherein R and R ′ are the same or different and each have 1 to 1 carbon atoms.
A lower alkyl of 5; and c is an integer of 1 to 3], preferably having a molecular weight of 100
A wax having a viscosity of from 0 to 40,000 at room temperature or a high-viscosity liquid is generally referred to, and can be produced by using an all-terminal functional isobutylene-based polymer obtained by a cationic polymerization method generally called an inifer method (Japanese Patent Laid-Open No. 8-108).
No. 231758). As typical commercial products,
formula

Embedded image [Wherein n is 5-400 and m is 5-400]
The "Epion" series manufactured by Kanegafuchi Chemical Industry Co., Ltd. having the chemical structure of

As the above-mentioned polyester containing a hydrolyzable silyl group, a polyester skeleton containing a hydrolyzable silyl group at the terminal or side chain similar to the above-mentioned modified silicone polymer and obtained by condensation of an acid component and an alcohol component (for example, A liquid polymer having a main chain of a condensate of adipic acid and propylene glycol) and usually having a molecular weight of about 300 to 15,000 is exemplified.

The above-mentioned alkoxysilyl group-containing acrylic polymer includes, for example, (a) an alkyl acrylate (preferably having 2 to 4 alkyl carbon atoms) (for example, ethyl) disclosed in Japanese Patent Publication No. 3-80829. Acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, n-octyl acrylate, etc.)
(B) vinylalkoxysilanes (eg, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinyldimethylmethoxysilane, etc.) and (meth) acryloxyalkoxysilanes (eg, γ-methacryloxypropyltrimethoxysilane, γ- Methacryloxypropylmethyldimethoxysilane) or one or a mixture of two or more selected from the group consisting of mercaptoalkoxylan (c) as a chain transfer agent.
(For example, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, etc.)
Radical copolymerization [usually using a polymerization initiator such as α, α′-azobisisobutyronitrile (AIBN), α, α′-azobisisovaleronitrile, benzoyl peroxide, methyl ethyl ketone peroxide] Known methods such as bulk polymerization and solution polymerization; or a redox catalyst such as a redox polymerization method in which a transition metal salt, an amine, or the like is combined with a peroxide initiator]. Molecular weight 3000-10
0000, average number of alkoxysilyl groups in one molecule of 1.5
(Ii) acrylates such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, propyl acrylate, pentyl acrylate, and stearyl acrylate; methyl methacrylate Methacrylates such as, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, benzyl methacrylate, cyclohexyl methacrylate; styrene or its derivatives (α-methylstyrene, chloromethylstyrene, etc.);
Fumaric acid diesters such as diethyl fumarate, dibutyl fumarate and dipropyl fumarate; vinyl halides such as vinyl chloride, vinylidene chloride, ethylene fluoride, vinylidene fluoride, vinylene fluoride, etc.] 100 parts (parts by weight, hereinafter the same) ) Includes an alkoxysilyl group-containing disulfide compound [eg, bis (trimethoxysilylmethyl) disulfide, bis (triethoxysilylmethyl)
Disulfide, bis (trimethoxysilylpropyl) disulfide, bis (triethoxysilylpropyl) disulfide, bis (methyldimethoxysilylmethyl) disulfide, bis (methyldiethoxysilylmethyl) disulfide, bis (propyldimethoxysilylmethyl) disulfide, bis ( Propyldiethoxysilylmethyl)
Disulfide, bis (dimethylmethoxysilylpropyl) disulfide, bis (dimethylethoxysilylpropyl) disulfide, etc.] in an amount of 0.05 to 50 parts (parts by weight, hereinafter the same) and, if necessary, an organic solvent (toluene, xylene, hexane, Photopolymerization (normal temperature to 50 to 60 ° C, 4 to 30) in ethyl acetate, dioctyl phthalate, etc.
(Light irradiation for time).

[0010] The curing catalyst used in the present invention is, specifically,
(I) a combination of a divalent organic tin compound and a tetravalent organic tin compound and / or an organic bismuth compound; or (ii) a combination of a tetravalent organic tin compound and an organic bismuth compound, which will be described in Examples below. As shown, it is recognized that the uncured thin layer is clearly improved as compared with the use of the divalent organotin compound alone.

Examples of the divalent organotin compound include tin octylate, tin stearate, tin naphthenate and the like, and at least one of them is used. Examples of the tetravalent organic tin compound include dibutyltin laurate, dibutyltin dilaurate, dibutyltin dioctoate, dibutyltin acetate, dioctyltin stearate, dioctyltin laurate, dioctyltin diversate, dibutyltin bistriethoxysilicate, dibutyltin bisisononyl. 3-mercaptopropionate, dibutyltin bisacetylacetonate, dibutyltin bis (o-phenylphenoxide), dibutyltin bisisooctylthioglycolate, dibutyltin oxide, dioctyltin oxide and the like. The seed is ready for use. Examples of the organic bismuth compound include compounds of the formula: Bi (COOR ") ₃ [wherein, R" is alkyl ", for example, bismuth trioctylate, bismuth trineodecanoate, etc., and at least one of these is used. To serve.

In the combination (i), for example, the weight ratio of the divalent organotin compound to the tetravalent organotin compound is usually in the range of 10: 1 to 1: 1. The weight ratio of the compound, the tetravalent organic tin compound and the organic bismuth compound may be usually selected in the range of 9: 190 to 45: 50: 5. In the combination (ii), the weight ratio of the tetravalent organic tin compound to the organic bismuth compound may be usually selected in the range of 1:20 to 1: 1. The amount of the curing catalyst composed of such a combination is usually the same for both combinations (i) and (ii).
0.001 to 10 parts, preferably 0.1 to 10 parts per 0 parts
What is necessary is just to select in the range of 10 parts. If the amount is less than 0.001 part, the curing catalyst function cannot be sufficiently performed, and if the amount exceeds 10 parts, the adhesiveness tends to deteriorate.

If necessary, conventional basic substances such as butylamine, octylamine, and the like may be used as cocatalysts.
Laurylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminoisopropylamine, xylylenediamine,
Triethylenediamine, guanidine, diphenylguanidine, 2,4,6-tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5.4.0) An appropriate amount of an organic amine compound such as undecene-7 may be blended. By the addition of the co-catalyst, the elastic resilience and durability can be improved and toughness can be imparted.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The curable composition according to the present invention is prepared by blending a predetermined ratio of a curing catalyst and, if necessary, a cocatalyst with the above-mentioned polymer containing a hydrolyzable silyl group as a main component. Agents (for example, heavy calcium carbonate, fatty acid-treated calcium carbonate, porous calcium carbonate, calcium silicate, fume silica, precipitated silica, carbon black, talc, titanium oxide, asbestos, glass fiber, mica, graphite, diatomaceous earth, clay, Silicic anhydride, clay, magnesium carbonate, quartz, aluminum fine powder, flint powder, zinc powder, etc.); plasticizer [for example, hydrocarbon oil, paraffinic process oil, dialkyl phthalate (dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, etc.) , Α-olefin oxide C ₆ -C ₁₂ alkyl esters of trimellitic acid, dibasic acid esters (dioctyl adipate, dioctyl sebacate, etc.), fatty acid esters, esters of polyalkylene glycol (diethylene glycol dibenzoate, triethylene glycol dibenzoate), Phosphate esters (tricresyl phosphate, tributyl phosphate, etc.) and the like];
Adhesives (eg, epoxy compounds, silane coupling agents, etc.); Anti-aging agents (eg, hindered phenols, mercaptans, sulfides, dithiocarboxylates, thioureas, thiophosphates, thioaldehydes, etc.); Stopping agents (for example, hydrogenated castor oil derivatives; metal soaps such as calcium stearate, aluminum stearate, and barium stearate); photocurable resins; physical property modifiers (various silane coupling agents);
Thixotropic agents; UV absorbers (eg, hindered amines,
(Benzotriazoles, etc.); an ozone deterioration inhibitor; a light stabilizer and the like are appropriately selected and blended. In addition,
In the composition of the present invention, these components may be used collectively as a one-component form, and from these components, a curing catalyst (and a co-catalyst, if necessary, hereinafter the same), or a curing catalyst and a plasticizer Or a part of the curing catalyst, the plasticizer, and the filler (which may contain other additives) may be separately cut and blended, and used as a two-component form to be mixed at the time of use. When an isobutylene-based polymer is used as the main component, it is preferably formed in a two-component form, and water may be blended on the main component side.

[0015]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Examples 1 and 2 and Comparative Examples 1 and 2 (1) Main agent The following components are blended to form a main agent. Component part Isobutylene polymer (Note 1) 150 Fatty acid-treated calcium carbonate 80 Heavy calcium carbonate 60 Paraffin-based process oil 60 Epoxy-based adhesive 5 Photocurable resin 3 Hindered phenol-based antioxidant 1 Benzotriazole-based light stabilizer 1 Hindered amine light stabilizer 1 Water 5 total 366 Note 1: "Epion EP505S" manufactured by Kanegafuchi Chemical Industry Co., Ltd. (molecular weight: about 20000, polymer content / hydrocarbon oil = 100/50)

(2) Curing agent Each component having the number of parts shown in Table 1 below is blended to obtain a uniform paste-like curing agent. Table 1 also shows the appearance color of the curing agent.

[Table 1]

(3) Curable composition and performance test To 100 parts of the above main agent, 10 parts of a curing agent was added, mixed by stirring, and then defoamed in vacuo to obtain a curable composition, which was subjected to the following performance tests. . Table 2 shows the results. i) Pot life At 10 ° C., 23 ° C. or 30 ° C., the maximum time (h) in which the state where spatula finishing is possible is maintained is measured. ii) Internal curability At 5 ° C., 10 ° C. or 20 ° C., the consistency after 24 hours is measured and visually judged. ：: no uncured portion is found inside ×: uncured portion is present inside iii) thin layer curability 0.05 mm, 0.1 mm thick on an aluminum plate
Apply at 0.2mm or 0.4mm, 24h at 60 ° C
The cured state is later determined by touch. ：: Completely cured Δ: Slightly uncured ×: Whole uncured iv) Measurement of physical properties For the curable compositions of Example 1 and Comparative Example 1, each physical property value is measured by H-type. In addition, the durability of both compositions was also examined, and both of them corresponded to the durability category 10030, and there was no difference in the durability.

[0018]

[Table 2]

[0019]

From the results in Table 2, it can be seen that the combination use of the curing catalyst according to the present invention (Examples 1 and 2) is substantially more effective in internal curability and physical properties than the single use (Comparative Examples 1 and 2). Although there is no significant difference in terms of durability (in other words, it does not affect the internal curability and durability, etc.), the pot life is extended to some extent, and the thin-layer curability is the same as the conventional two-layer curability. A remarkable effect is recognized as compared with the valence tin compound (Comparative Example 1).
The curable composition of the present invention is useful for architectural sealing materials, and particularly in application sites such as joints between metal panels and seal portions around glass windows, a thin layer applied portion occurs, and the thin layer uncured. It is suitable for sites that are likely to occur. In addition, the curable composition of the present invention is mainly used for building sealing materials, but in addition to this, automobiles, electric appliances, civil engineering sealing materials and other adhesives, paints, coating materials,
It can be applied to potting materials, molded products, and the like.

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Claims (7)

[Claims] 1. A curable composition comprising a hydrolyzable silyl group-containing polymer as a main component and at least two of three groups of a divalent organic tin compound, a tetravalent organic tin compound and an organic bismuth compound. A curable composition excellent in curability of a thin layer portion, wherein a curable catalyst comprising a combination of at least one member selected from each group is blended. 2. The amount of the curing catalyst is 0.001 to 10 parts by weight per 100 parts by weight of the hydrolyzable silyl group-containing polymer.
The curable composition according to claim 1, which is in parts by weight. 3. The curable composition according to claim 1, further comprising a basic substance as a promoter. 4. The curable composition according to claim 1, wherein the curing catalyst is a combination of a divalent organic tin compound and a tetravalent organic tin compound. 5. The weight ratio of the divalent organotin compound to the tetravalent organotin compound is from 10: 1 to 1: 1 and the amount of the curing catalyst composed of the combination of the two compounds is determined to be hydrolyzable silyl. The curable composition according to claim 4, wherein the amount is 0.1 to 10 parts by weight based on 100 parts by weight of the group-containing polymer. 6. The curable composition according to claim 1, wherein the curing catalyst is a combination of a tetravalent organic tin compound and an organic bismuth compound. 7. The weight ratio of the tetravalent organotin compound to the organic bismuth compound is from 1:20 to 1: 1 and the amount of the curing catalyst comprising the combination of the two compounds is the amount of the hydrolyzable silyl group-containing polymer. The curable composition according to claim 6, wherein the amount is 0.1 to 10 parts by weight based on 100 parts by weight.