JPH10324811A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable composition having good initial curability, especially initial curability at low temperatures and requiring a short time taken for the properties such as solvent resistance to reach a certain level by including a specified vinyl resin, a compound containing an epoxy group and a hydrolyzable group in the molecule and a curing catalyst. SOLUTION: A monomer containing a hydrolyzable silyl group, 0.1-50 wt.% amino-containing monomer and a vinyl monomer are reacted with each other in the presence of an azoic radical polymerization initiator to obtain a vinyl resin the main chain of which comprises a vinyl polymer and which contains at least one hydrolyzable group and at least one bonded silicon group in the molecule, contains units derived from an amino-containing vinyl monomer as a comonomer and has a number - average molecular weight of 3,000-30,000. This resin is mixed with a compound having an epoxy group and a hydrolyzable silyl group in the molecule and used in an amount of 0.1-5 equivalents per equivalent of the amino groups of the resin and 0.01-20 pts.wt., per 100 pts.wt. resin, curing catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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.

[0002]

2. Description of the Related 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 is a cured product having excellent weather resistance. It has been found to be useful as a coating agent, and a patent application has been filed (JP-A-54-36395, etc.).

[0003]

However, since the composition is cured by moisture in the atmosphere, if the number of hydrolyzable silyl groups in one 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.

[0004]

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

That is, the present invention provides (a) a method wherein the main chain is substantially composed of a vinyl polymer and has at least one silicon group (hydrolyzable silyl group) bonded to a hydrolyzable group per molecule. And a vinyl-based resin further containing a unit derived from a vinyl-based monomer having an amino group as a copolymer component,
(B) a compound having both an epoxy group and a hydrolyzable silyl group in one molecule, and (c) a curing catalyst,
The curable composition wherein the epoxy group in the component (b) is 0.1 to 5 equivalents to 1 equivalent of the amino group in the component (a) (Claim 1) is a copolymer component of the vinyl resin. 2. The composition according to claim 1, wherein the vinyl monomer having an amino group is at least one selected from the group consisting of dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates. 2. The composition according to claim 1, wherein the compound having both an epoxy group and a hydrolyzable silyl group is γ-glycidoxypropyl trialkoxysilane.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The composition of the present invention contains a silicon group (hydrolyzable silyl group) in which the main chain (a) is substantially composed of a vinyl polymer and is bonded to a hydrolyzable group. 1
Contains a vinyl resin having at least one in the molecule and further containing a unit derived from a vinyl monomer having an amino group as a copolymerization component (hereinafter also referred to as a hydrolyzable silyl group-containing vinyl resin). It has been impatient.

The component (a) is a main component of a cured product from the composition of the present invention. Since the main chain is substantially composed of a vinyl polymer, the cured product has weather resistance, chemical resistance and the like. 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, it can be cured at room temperature, and the weather resistance and chemical resistance of the cured product can be improved by the formation of chemically stable siloxane bonds. 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.

[0008] The molecular weight of the hydrolyzable silyl group-containing vinyl resin is not particularly limited, but from the viewpoint of workability, stability, appearance, solvent resistance, chemical resistance and the like, the number average molecular weight is 3,000 to 3,000. Those having a size 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 is obtained as a part of a main chain or a side chain. (As long as the main chain is substantially composed of a vinyl polymer).

The vinyl monomer used for producing the component (a) is not particularly limited, and may be, 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)
Esters of unsaturated polycarboxylic acids such as acrylates, diesters or half esters of polycarboxylic acids (maleic acid, fumaric acid, itaconic acid, etc.) with linear or branched alcohols having 1 to 20 carbon atoms; styrene, α- Aromatic hydrocarbon vinyl compounds such as methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene, and vinyltoluene; vinyl ester and allyl ester compounds such as vinyl acetate, vinyl propionate and diallyl phthalate; and (meth) acrylonitrile Such nitrile group-containing vinyl compounds; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, Alonix 5700 (East Synthesis Co., Ltd.), Placce
l FA-1, Placel FA-4, Placc
hydroxyl-containing vinyl compounds such as el FM-1 and Placel FM-4 (all manufactured by Daicel Chemical Co., Ltd.);
Acids such as (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid, and salts thereof (such as alkali metal salts, ammonium salts, and amine salts); acid anhydrides of unsaturated carboxylic acids such as maleic anhydride; vinyl methyl Other vinyl compounds such as ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, maleimide, N-vinylimidazole, and vinyl sulfonic acid are exemplified.

Specific examples of the hydrolyzable silyl group-containing monomer include, for example,

[0012]

Embedded image

And the like.

Specific examples of the amino group-containing monomer include dialkylaminoalkyl (e.g., dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, and diethylaminopropyl (meth) acrylate). N-dimethylaminoethyl (meth) acrylamide, N-diethylaminoethyl (meth) acrylamide, N-dimethylaminopropyl (meth) acrylamide, N-dialkylaminoalkyl (meth) such as N-diethylaminopropyl (meth) acrylamide ) Acrylamide; t-butylaminoethyl (meth) acrylate, t-butylaminopropyl (meth) acrylate, aziridinylethyl (meth) acrylate, Rorijiniruechiru (meth) acrylate, piperidinylethyl (meth) acrylate, vinyl pyridine, aminoethyl vinyl ether. In particular, dialkylaminoalkyl (meth) acrylate is desirable from the viewpoint of the balance between the stability of the composition and the curability. In addition, the content of the amino group-containing monomer,
0.1 to 50 in the hydrolyzable silyl group-containing vinyl resin
% (% By weight, hereinafter the same), preferably 0.5 to 20%.

The method for producing the copolymer of the hydrolyzable silyl group-containing monomer, amino group-containing monomer and vinyl monomer is not particularly limited.
395, 57-36109, 58-1
No. 57810, etc., 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-SS-Si (OCH ₃ ) ₃ , (CH ₃ O) ₃
By using a chain transfer agent such as _{Si-S 8 -Si (OCH 3} ) 3, it is possible to adjust the molecular weight. 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.

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

In the composition of the present invention, component (b) 1
A compound having both an epoxy group and a hydrolyzable silyl group in the molecule is contained. The component (b) is a component used to react and crosslink with an amino group in a hydrolyzable silyl group-containing vinyl resin, and includes an epoxy group which functions to react with an amino group in one molecule, and a vinyl type resin. By using a compound having a silyl group in the resin or a hydrolyzable silyl group that functions to crosslink with silyl groups in the epoxy compound due to moisture, an effect of improving initial curability is achieved.

Representative compounds having both an epoxy group and a hydrolyzable silyl group in one molecule as the component (b) include a vinyl polymer having both functional groups and a silane having an epoxy group. Coupling agents and the like. 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 1,000 to 3,000.
A value of 0 is desirable from the viewpoint of workability.

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

Representative examples of the silane coupling agent having an epoxy group include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, adducts of γ-glycidoxypropyltriisopropenyloxysilane, γ-glycidoxypropyltriiminooxysilane, γ-isocyanatopropyltriisopropenyloxysilane, γ-isocyanatopropyltrimethoxysilane and the like with glycidol; -Adducts of aminopropyltrimethoxysilane and diepoxy compounds. From the viewpoint of economy and the like, γ-glycidoxypropyl trialkoxysilane such as γ-glycidoxypropyltrimethoxysilane is desirable.

The component (b) is such that the epoxy group is 0.1 to 5 equivalents to 1 equivalent of the amino group in the hydrolyzable silyl group-containing vinyl resin which is the component (a) from the viewpoint of curability. Add in appropriate proportions. When two or more types of the component (b) are used, the total amount of the epoxy groups is set in 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, tin octylate, and the like. Phosphoric acid or phosphate such as monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, didecyl phosphate; alkyl titanate; organic Aluminum; maleic acid, p
-Acidic compounds such as toluenesulfonic acid; alkaline compounds such as sodium hydroxide and potassium hydroxide. These curing catalysts may be used alone,
More than one species may be used in combination.

The amount of the curing catalyst added to 100 parts of the hydrolyzable silyl group-containing vinyl resin is generally from 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. However, in order to ensure long-term stability and stability that does not cause any problem even when repeatedly used, dehydrating agents are required. It is preferable to use an agent.

Specific examples of the dehydrating agent include, for example, methyl orthoformate, ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate, methyltrimethoxysilane, γ
-Hydrolysable ester compounds such as methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, methyl silicate and ethyl silicate. 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 may further contain additives such as various pigments, dyes, ultraviolet absorbers, anti-settling agents, and leveling agents, depending on the intended use; cellulose resins such as nitrocellulose and cellulose acetate butyrate; Alkyd resin,
Resins such as an acrylic resin, a vinyl chloride resin, a chlorinated propylene resin, a chloride rubber, and polyvinyl butyral can be added.

[0028]

EXAMPLES 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.
Heated to 0 ° C. In this reactor, butyl acrylate 4
A solution consisting of 80 g, 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 the monomer addition, a separately prepared solution of 0.5 g of azobisisobutyronitrile and 200 g of toluene was added over 1 hour, and after 1 hour, polymerization was carried out to obtain a hydrolyzable silyl group-containing vinyl resin (a −
I got 1).

The obtained resin solution has a nonvolatile content of 60%.
And adjusted to 50% by diluting with xylene. Also,
The number average molecular weight by GPC was about 25,000.

Synthesis Examples 2-5 Hydrolyzable silyl group-containing vinyl resins (a-2) to (a-2) were prepared 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-3), a 50% solution of a hydrolyzable silyl group-containing vinyl resin having no amino group (a-4) and a vinyl resin having no hydrolyzable silyl group (a-5) were obtained. Each of the obtained resins had a number average molecular weight of about 25,000.

[0032]

[Table 1]

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 stored at 23 ° C. and 5 ° C. for one day. Thereafter, the initial curability was examined by measuring the gel fraction.

The gel fraction was such that about 0.2 g of the coating film was peeled off from the polyethylene film, wrapped with a 200-mesh wire net, weighed, immersed in acetone at room temperature for 24 hours, and then heated to 50 ° C.
For 2 hours, weighed, and evaluated by calculating the ratio to the original weight. Table 2 shows the results. The higher the gel fraction value, the better the initial curability.

[0035]

[Table 2]

[0036]

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.

Claims (3)

[Claims] (A) The main chain is substantially composed of a vinyl polymer and has at least one silicon group (hydrolyzable silyl group) bonded to a hydrolyzable group in one molecule. A vinyl resin containing a unit derived from a vinyl monomer having an amino group as a polymerization component, (b) a compound having an epoxy group and a hydrolyzable silyl group in one molecule,
And (c) a curing catalyst, wherein the epoxy group in the component (b) is 0.1 to 0.1 equivalent to 1 equivalent of the amino group in the component (a).
A curable composition having 5 equivalents. 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.