JP2862898B2 - Curable composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a curable composition comprising a specific hydrolyzable silyl group-containing vinyl resin, a specific epoxy group-containing compound and a curing catalyst. Particularly, it relates to a curable composition useful as a coating agent.

[Prior art] A vinyl polymer containing a hydrolyzable silyl group has room-temperature curability, has good adhesion to inorganic substances such as concrete, glass, steel plate and aluminum, and becomes a cured product having excellent weather resistance. Have been found to be useful as coating agents, and a patent application has been filed (JP-A-54-36395).
Issue publication).

[Problems to be Solved by the Invention] However, since it is cured by moisture in the atmosphere, it is difficult to cure by
When the number of hydrolyzable silyl groups in the molecule is small, the initial curability is poor. Particularly at low temperatures, it takes time for physical properties such as hardness and solvent resistance to reach a certain level.

[Means for Solving the Problems] The present inventors have conducted intensive studies to solve the above problems, and as a result, completed the present invention.

That is, the present invention provides: (a) a silicon group (hydrolyzable silyl group) having a main chain substantially consisting of a vinyl polymer and bonded to a hydrolyzable group;
A vinyl resin having at least one unit in the molecule and further containing a unit derived from a vinyl monomer having an amino group as a copolymer component, (b) a compound having two or more epoxy groups in one molecule, or The present invention relates to a compound having two or more epoxy groups in one molecule, a compound having an epoxy group and a hydrolyzable silyl group in one molecule, and a curable composition comprising (c) a curing catalyst.

[Examples] In the composition of the present invention, the main chain as the component (a) is substantially composed of a vinyl polymer, and one molecule of a silicon group (hydrolyzable silyl group) bonded to a hydrolyzable group. A vinyl-based resin having at least one of them and further containing a unit derived from a vinyl-based monomer having an amino group as a copolymerization component (hereinafter also referred to as a hydrolyzable silyl group-containing vinyl-based resin). Have been.

The component (a) is a component that is a main component of a cured product from the composition of the present invention. Since the main chain thereof is substantially composed of a vinyl polymer, the cured product is excellent in weather resistance, chemical resistance, and the like, Further, by changing the copolymer composition, a wide range of resin designs from soft to hard can be designed. In addition, since there is at least one, and preferably two or more hydrolyzable silyl groups in a molecule which hydrolyze into silanol groups in the presence of moisture and further form and cure siloxane bonds, the presence of moisture In addition to being able to cure at room temperature, the formation of chemically stable siloxane bonds, the weather resistance of the cured product,
Chemical resistance can be improved. Further, since a unit derived from a vinyl monomer having an amino group (amino group-containing monomer) is contained as a copolymer component, preferably two or more units are contained in one molecule. Crosslinking with the compound becomes possible.

Although there is no particular limitation on the molecular weight and the like of the hydrolyzable silyl group-containing vinyl resin, workability, stability, appearance,
From the viewpoint of solvent resistance, chemical resistance, etc., the number average molecular weight is 3000-
Those of about 30,000 are generally used.

The hydrolyzable silyl group-containing vinyl resin is obtained, for example, by copolymerizing a vinyl monomer with a hydrolyzable silyl group-containing monomer and an amino group-containing monomer, and as a part of the main chain or side chain (where the main chain is It may contain a urethane bond, a siloxane bond, etc. (in a range substantially consisting of a vinyl polymer).

The vinyl monomer used for producing the component (a) is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, tert-butyl (meth) acrylate, iso-
Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate,
Benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, polycarboxylic acid (maleic acid, fumaric acid, itaconic acid, etc.) having 1 to 20 carbon atoms Esters of unsaturated carboxylic acids such as diesters or half esters with chain or branched alcohols; styrene, α-methylstyrene,
Aromatic hydrocarbon vinyl compounds such as chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene, and vinyltoluene; vinyl ester and acryl ester compounds such as vinyl acetate, vinyl propionate and diallyl phthalate; nitriles such as (meth) acrylonitrile Group-containing vinyl compound; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2
-Hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, Alonix 5700 (manufactured by Toagosei Co., Ltd.), Placcel FA-1, Placcel FA-4, Placce
l FM-1, Placcel FM-4 (Daicel Chemical Co., Ltd.)
(Meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, etc., salts thereof (alkali metal salts, ammonium salts, amine salts, etc.); unsaturated acids such as maleic anhydride Acid anhydrides of carboxylic acids; and other vinyl compounds such as vinyl methyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, maleimide, N-vinylimidazole, and vinyl sulfonic acid.

Specific examples of the hydrolyzable silyl group-containing monomer include, for example, CH ₂ CHCHSi (CH ₃ ) Cl ₂ , CH ₂ CHCHSi (OCH ₃ ) ₃ , CH ₂ CHCHSiCl ₃ , _{CH 2 = CHCOO (CH 2)} 3 Si (OCH 3) 3, CH 2 = CHCOO (CH 2) 3 Si (CH 3) Cl 2, CH 2 = CHCOO (CH 2) 3 SiCl 3, _{CH 2 = C (CH 3)} COO (CH 2) 3 Si (OCH 3) 3, CH 2 = C (CH 3) COO (CH 2) 3 Si (CH 3) Cl 2, CH 2 = C (CH 3 ) COO (CH ₂ ) ₃ SiCl ₃ , And so on.

Specific examples of the amino group-containing monomer include, for example, dialkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate, diethylaminoester (meth) acrylate, dimethylaminopropyl (meth) acrylate, and diethylaminopropyl (meth) acrylate. N-dialkylaminoalkyl (meth) acrylamides such as N-dimethylaminoethyl (meth) acrylamide, N-dimethylaminoethyl (meth) allylamide, N-dimethylaminopropyl (meth) allylamide, N-diethylaminopropyl (meth) acrylamide t-butylaminoethyl (meth) acrylate, t-butylaminopropyl (meth) acrylate, aziridinylethyl (meth) acrylate, pyrrolidinyles Ter (meth) acrylate,
Examples include piperidinylethyl (meth) acrylate, vinylpyridine, aminoethyl vinyl ether and the like.
In particular, dialkylaminoalkyl (meth) acrylate is desirable from the viewpoint of the balance between the stability of the composition and the curability. The content of the amino group-containing monomer in the hydrolyzable silyl group-containing vinyl resin is 0.1 to 50% (% by weight,
The same applies hereinafter), and preferably 0.5 to 20%.

The method for producing the copolymer of these hydrolyzable silyl group-containing monomer, amino group-containing monomer and vinyl monomer is not particularly limited, and examples thereof include JP-A-54-36395 and JP-A-54-36395.
Nos. 7,36,109 and 58,157,810 may be used, and a solution polymerization method using an azo radical initiator such as azobisisobutyronitrile is particularly preferable.

If necessary, for example, n-dodecyl mercaptan, t-dodecyl mercaptan, n-butyl mercaptan, γ-mercaptopropyltrimethoxysilane, γ-
Mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, (CH ₃ O) ₃ Si—S—S—Si (OCH ₃ ) ₃ , (CH ₃ O) ₃ Si— S ₈
By using a chain transfer agent such as -Si (OCH _{3) 3,}
The molecular weight can be adjusted. In particular, when a chain transfer agent having a hydrolyzable silyl group in the molecule, for example, γ-mercaptopropyltrimethoxysilane, the hydrolyzable silyl group can be introduced into the terminal of the vinyl polymer.

Polymerization solvents include, for example, hydrocarbons such as toluene, xylene, n-hexane and cyclohexane;
Acetates such as butyl acetate; alcohols such as methanol, ethanol, isopropanol and n-butanol; ethers such as ethyl cellosolve, butyl cellosolve, cellosolve acetate; methyl ethyl ketone, ethyl acetoacetate, acetylacetone, diacetone alcohol, methyl isobutyl ketone There is no particular limitation as long as it is a non-reactive solvent such as a ketone such as acetone.

The composition of the present invention includes a component (b), a compound having two or more epoxy groups in one molecule (hereinafter, also referred to as a component (b-1)) or a compound having two or more epoxy groups in one molecule. And a compound having both an epoxy group and a hydrolyzable silyl group in one molecule (hereinafter also referred to as a component (b-2)). The component (b) is a component used to react and crosslink with an amino group in the hydrolyzable silyl group-containing vinyl resin, and has two or more epoxy groups that function to react with the amino group in one molecule. Compound (b-1) component) or an epoxy group that functions to react with an amino group in one molecule and a silyl group in a vinyl resin or a silyl group in an epoxy compound, which functions to crosslink with moisture. By using the compound (b-2) having a hydrolyzable silyl group, the effect of improving the initial curability is achieved.

Representative compounds having both an epoxy group and a hydrolyzable silyl group in one molecule include a vinyl polymer having both functional groups and a silane coupling agent having an epoxy group. It is necessary that at least one of both functional groups in the vinyl polymer is contained in one molecule, and the molecular weight of the vinyl polymer is preferably from 1,000 to 30,000 from the viewpoint of workability.

As a method for preparing the vinyl polymer having both functional groups, the above-mentioned hydrolyzable silyl group-containing monomer and (β-methyl) glycidyl (meth) acrylate,
A vinyl monomer having an epoxy group such as allyl glycidyl ether, di (β-methyl) glycidyl malate and di (β-methyl) glycidyl fumarate, together with the above-mentioned other vinyl monomers copolymerizable therewith, if necessary. For example, solution radical copolymerization or solution radical (co) polymerization using an epoxy group-containing vinyl monomer as an essential component in the presence of a hydrolyzable silyl group-containing chain transfer agent such as γ-mercaptopropyltrimethoxysilane Method.

Representative examples of the silane coupling agent having an epoxy group include, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, Adducts of sidoxypropyltriisopropenyloxysilane, γ-glycidoxypropyltriiminooxysilane, γ-isocyanatopropyltriisopropenyloxysilane, γ-isocyanatopropyltrimethoxysilane and the like with glycidol;
An adduct of aminopropyltrimethoxysilane and the like with a diepoxy compound may be mentioned. Γ such as γ-glycidoxypropyltrimethoxysilane from the viewpoint of economy, etc.
Glycidoxypropyl trialkoxysilane is preferred.

Specific examples of the compound having two or more epoxy groups per molecule (component (b-1)) include ethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether. Polyglycidyl ethers of polyhydric alcohols (polyols), such as diglycidyl ether of bisphenol A and triglycidyl ether of glycerin; diglycidyl esters of phthalic acid, diglycidyl esters of isophthalic acid, and diglycidyl esters of adipic acid Polycarboxylic acid (polycarboxylic acid)
Polyglycidyl esters of: diglycidyl ether type epoxy resin from bisphenol A or bisphenol F, novolak type epoxy resin, epoxy resin containing a hydantoin ring, diglycidyl ether of polyglycol such as polyethylene glycol and polypropylene glycol, or urethane-modified epoxy resin Polyepoxy compounds such as various epoxy resins such as epoxy urethane resins, glycidyl ester ether of p-oxybenzoic acid, various vinyl (co) polymers having an epoxy group in a side chain, and epoxy-modified silicone oil. can give.

The curability of the component (b) is such that the epoxy group is added in an amount of 0.01 to 10 equivalents to 1 equivalent of the amino group in the hydrolyzable silyl group-containing vinyl resin as the component (a). From the viewpoint, it is preferably 0.1 to 5 equivalents. When two or more components (b) are used, the total amount of the epoxy groups is preferably within the above range.

Specific examples of the curing catalyst which is the component (c) used in the present invention include organic tin compounds such as dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, and tin octylate; phosphoric acid, monomethyl phosphate Phosphoric acid or a phosphoric acid ester such as monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, didecyl phosphate; alkyl titanate; organoaluminum; Acidic compounds such as maleic acid and p-toluenesulfonic acid; and alkaline compounds such as sodium hydroxide and potassium hydroxide. These curing catalysts may be used alone or in combination of two or more.

The amount of the curing catalyst added to 100 parts of the hydrolyzable silyl group-containing vinyl resin is generally 0.01 to 20 parts, preferably
0.01 to 10 parts.

A dehydrating agent may or may not be used in the room-temperature-curable composition of the present invention, but in order to ensure long-term stability and stability without any problem even when used repeatedly, a dehydrating agent is used. Is more preferred.

Specific examples of the dehydrating agent include, for example, methyl orthoformate, ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate, methyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, methosilicate, ethylsilicate And the like. These hydrolyzable ester compounds may be added before the polymerization of the silyl group-containing vinyl copolymer, may be added during the polymerization, or may be added after the polymerization.

The composition of the present invention further includes various pigments depending on the application,
Additives such as dyes, ultraviolet absorbers, anti-settling agents, leveling agents; fibrous resins such as nitrocellulose and cellulose acetate butyrate; alkyd resins, acrylic resins, vinyl chloride resins, chlorinated propylene resins, and chlorinated rubber And a resin such as polyvinyl butyral.

 Next, the composition of the present invention will be described based on examples.

Synthesis Example 1 A reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube, a dropping funnel and a cooling tube was charged with 360 g of xylene, and heated at 110 ° C.
Heated. In this reactor, 480 g of butyl acrylate,
A solution consisting of 380 g of methyl methacrylate, 48 g of γ-methacryloxypropyltrimethoxysilane, 100 g of dimethylaminoethyl methacrylate and 3 g of azobisisobutyronitrile was continuously added over 3 hours. After completion of monomer addition, separately prepared azobisisobutyronitrile 0.5 g
Then, a solution of 200 g of toluene was added over 1 hour, and the polymerization was further performed for 1 hour to obtain a hydrolyzable silyl group-containing vinyl resin (a-1).

The obtained resin solution had a nonvolatile content of 60%, and was diluted with xylene to be adjusted to 50%. The number average molecular weight determined by the GPC method was about 25,000.

Synthesis Examples 2 to 5 Hydrolyzable silyl group-containing vinyl resins (a-2) to (a-3) in the same manner as in Synthesis Example 1 except that the proportions of the monomers used were changed as shown in Table 1. ), A hydrolyzable silyl group-containing vinyl resin having no amino group (a-4) and a vinyl resin having no hydrolyzable silyl group (a-5)
To give a 50% solution. Each of the obtained resins had a number average molecular weight of about 25,000.

Examples 1 to 3, Reference Examples 1 to 3 and Comparative Examples 1 to 3 The compositions prepared so as to have the compositions shown in Table 2 were coated on a polyethylene film, and were applied under the conditions of 23 ° C and 5 ° C, respectively. After storage for one day, the initial curability was determined by measuring the gel fraction.

The gel fraction was determined by peeling about 0.2 g of the coating film from the polyethylene film, wrapping it with a 200-mesh wire net, weighing it, immersing it in acetone at room temperature for 24 hours, drying it at 50 ° C for 2 hours, weighing it, and weighing it. The evaluation was made by obtaining the ratio with respect to. The results are shown in Table 2. The higher the gel fraction value, the better the initial curability.

[Effects of the Invention] The composition of the present invention has good initial curability, especially at low temperatures, and has a short time until physical properties such as solvent resistance reach a certain level.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08L 1/00-101/14 C09D 1/00-201/10 C08K 3/00-13/08

Claims (4)

(57) [Claims] (A) a main chain consisting essentially of a vinyl polymer, having at least one silicon group (hydrolyzable silyl group) bonded to a hydrolyzable group per molecule; A vinyl resin containing a unit derived from a vinyl monomer having an amino group as a polymerization component, (b) a compound having two or more epoxy groups in one molecule, or a compound having two or more epoxy groups in one molecule A curable composition comprising a compound, a compound having an epoxy group and a hydrolyzable silyl group in one molecule, and (c) a curing catalyst. 2. The vinyl-based monomer having an amino group, which is a copolymer component of the vinyl-based resin, is at least one selected from the group consisting of dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates. A composition as described. 3. The composition according to claim 1, wherein the compound having both an epoxy group and a hydrolyzable silyl group in one molecule is γ-glycidoxypropyl trialkoxysilane. 4. The composition according to claim 1, wherein the compound having two or more epoxy groups in one molecule is a bisphenol A type epoxy resin.