JP2002167411A - Coating material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low molecular weight vinyl copolymer capable of producing a coating material composition which is low in viscosity, small is solvent content and excellent in the weather resistance and solvent resistance, or the like, and to provide the composition using the copolymer. SOLUTION: The method for producing the copolymer is characterized in that a mixture composed of a hydroxyl group-containing vinyl monomer of 5-50 wt.%, which is represented by the formula CH2=CR1-CO-O-R2-CH2-OH [wherein R1 is hydrogen or methyl group; R2 is a 2-9C hydrocarbon group], and other copolymerizable vinyl monomer of 50-95 wt.% is subjected to the copolymerization using a radical polymerization initiator in a sealed reactor the inside temperature of which is maintained at 140-200 deg.C in the presence of an organic solvent to obtain a vinyl copolymer solution having a number average molecular weight of 500-4,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a vinyl copolymer and a coating composition using the same. More specifically, the present invention relates to a method for producing a novel and useful low-molecular-weight vinyl copolymer which has low viscosity, excellent weather resistance and solvent resistance, and has a low odor, and a coating composition using the same. .

[0002]

2. Description of the Related Art In recent years, low-molecular-weight vinyl copolymers for coatings have been receiving attention for the purpose of reducing solvents as a measure against environmental pollution. Conventionally, a solution polymerization method has been generally used for vinyl copolymers in terms of ease of production, but it is extremely difficult to produce a low molecular weight vinyl copolymer having a number average molecular weight of 4,000 or less. Met. That is, in order to obtain such a low-molecular-weight vinyl copolymer, a method of using a large amount of a radical polymerization initiator or a method of using a mercaptan-based chain transfer agent has been adopted, but in particular, a mercaptan-based chain transfer agent is used. If this is used, it may cause a bad smell of the vinyl copolymer solution, and the weather resistance and the solvent resistance of the finally obtained coating film are lowered, which is not practical.

Therefore, as a method for solving these problems, a method using a closed reaction vessel has been proposed (Japanese Patent Publication No. 63-30334). Although this method can provide a vinyl copolymer solution having a low odor without using a chain transfer agent, the vinyl copolymer disclosed herein can be converted to a high degree of weather resistance and solvent resistance. If it is used as a top coat for automobiles or a top coat for architectural exterior, which is required, there is a problem that the obtained coating film is insufficiently cured and cannot be applied.

In order to obtain sufficient curability in the case of the low-molecular-weight vinyl copolymer, it is conceivable to increase the content of a hydroxyl group as a cured site. When the amount of 2-hydroxyethyl (meth) acrylate, which is a monomer, is increased, the dilutability in an organic solvent is reduced and the viscosity becomes high.

In a low molecular weight vinyl copolymer having a number average molecular weight of 4,000 or less, the degree of molecular weight dispersion (weight average molecular weight / number average molecular weight; the same applies hereinafter) is also important.
The low molecular weight portion lowers the viscosity of the vinyl copolymer solution, but the content of the functional group as a hardened site in one molecule is small and hardening tends to be insufficient, and the high molecular weight portion is hardened in one molecule. The content of the functional group as a large amount increases the viscosity of the vinyl copolymer solution. Accordingly, in the low-molecular-weight vinyl copolymer having a number-average molecular weight of 4,000 or less, control of the low-molecular-weight portion and the high-molecular-weight portion, from the viewpoint of compatibility between low viscosity and excellent weather resistance and solvent resistance, that is, It is a practically important task to reduce the molecular weight dispersity.

Conventionally, the production of vinyl copolymers has been
rt-butyl peroxy-2-ethylhexanoate, tert-butyl peroxybenzoate, di-ter
Tert-butyl peroxide-based radical polymerization initiators such as t-butyl peroxide and tert-butylcumyl peroxide have been used, but these radical polymerization initiators are used when used at 140 to 200 ° C. Is a compound which easily causes a hydrogen abstraction reaction on the produced copolymer to generate a high molecular weight portion, and has an undesirable result of increasing the molecular weight dispersity.

[0007]

In the prior art,
The reality is that a vinyl copolymer having low viscosity and excellent weather resistance and solvent resistance has not yet been developed. Therefore, the problem to be solved by the present invention is a low-molecular-weight vinyl copolymer capable of obtaining a coating composition having a low viscosity, and having a low solvent content and excellent weather resistance and solvent resistance. An object of the present invention is to provide a coating composition using the same.

[0008]

The inventors of the present invention have conducted intensive studies with the aim of solving the problems to be solved by the invention as described above. By copolymerizing a mixture of vinyl monomers containing a specific hydroxyl group-containing vinyl monomer in a closed reaction vessel maintained at ~ 200 ° C, and further using a specific radical polymerization initiator Thus, the present inventors have found that the above-mentioned problems can be solved, and have now completed the present invention.

That is, the present invention provides: (1) In a closed reaction vessel maintained at a temperature of 140 to 200 ° C. in a vessel in the presence of an organic solvent, the following general formula (1): CH 2 ＝ CR 1 —CO—O—R 2 -CH2 -OH (1) (wherein, R1 is hydrogen or a methyl group, and R2 is a group having 2 carbon atoms.
To 9 hydrocarbon groups. A) a mixture of 5 to 50% by weight of a hydroxyl group-containing vinyl monomer (a) represented by the formula (1) and 50 to 95% by weight of another copolymerizable vinyl monomer (b) using a radical polymerization initiator. And producing a vinyl-based copolymer solution having a number average molecular weight of 500 to 4,000, a method for producing a vinyl-based copolymer,

(2) A radical polymerization initiator represented by the following general formula (2): R 1-(CO) n -OO-C (CH 3) 2 -R 2 (2) (wherein, R 1 is a group having 2 to 10 carbon atoms) An alkyl group, an alkoxy group having 2 to 10 carbon atoms, a phenyl group or a benzyl group, R2 represents an alkyl group having 2 to 5 carbon atoms, and n represents an integer of 0 or 1.) (1) The method for producing a vinyl copolymer according to (1),

(3) The vinyl copolymer according to the above (1) or (2), wherein the weight average molecular weight / number average molecular weight of the vinyl copolymer is 1.0 to 2.5. A method for producing a polymer,

(4) A vinyl copolymer obtained by the production method according to any one of (1) to (3),

(5) a coating composition comprising a vinyl copolymer obtained by the production method according to any one of the above (1) to (3) and a curing agent;

(6) The coating composition according to the above (5), wherein the curing agent is an isocyanate compound and / or an amino resin.

(7) A coated article to which the coating composition according to (5) or (6) is applied.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The following general formula (1), which is an essential vinyl monomer used in the present invention, CH2 = CR1-CO-OR2-CH2-OH (1) (wherein R1 is hydrogen or a methyl group, R2 Has 2 to 2 carbon atoms
Hydrocarbon group-containing vinyl monomer (a) represented by the following formula (3): 3-hydroxypropyl (meth) acrylate, 2-methyl-3-hydroxy Propyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-methyl-4-hydroxybutyl (meth) acrylate, 3-methyl-4-hydroxybutyl (meth) acrylate, 2-methyl-5-hydroxypentyl ( (Meth) acrylate, 6-hydroxyhexyl (meth) acrylate, (4-hydroxymethylcyclohexyl)
-Methyl (meth) acrylate and the like, and the amount thereof is preferably 5 to 50% by weight from the viewpoints of various properties such as solvent resistance of the cured coating film and non-volatile components of the coating. These hydroxyl group-containing vinyl monomers may be used alone or in combination of two or more.

Further, if only particularly typical examples of other copolymerizable vinyl monomers (b) of the present invention are given, only

Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate , Sec-
Butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, "acrylester SL"
[Methacrylate mixtures having 12 and 13 carbon atoms, manufactured by Mitsubishi Rayon Co., Ltd.], various esters of alkyl alcohols having 1 to 22 carbon atoms and (meth) acrylic acid such as stearyl (meth) acrylate (Alkyl (meth) acrylates);

Various ω-alkoxyalkyl (meth) acrylates such as 2-methoxyethyl (meth) acrylate and 4-methoxybutyl (meth) acrylate;

Cyclohexyl (meth) acrylate, 4
Various cycloalkyl (meth) acrylates such as -tert-butylcyclohexyl (meth) acrylate, isobornyl (meth) acrylate and the like;

Various aromatic-containing alkyl (meth) acrylates such as benzyl (meth) acrylate, 2-phenylethyl (meth) acrylate and the like;

Styrene, α-methylstyrene, p-te
various aromatic vinyl monomers such as rt-butylstyrene, vinyltoluene and the like;

Vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, "Veoba 9, Veoba 1
0 "[Vinyl esters of branched (branched) aliphatic monocarboxylic acids manufactured by Shell, The Netherlands] and the like;

Various halogenated olefins such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride and the like;

"Biscoat 3F, Biscoat 3FM, Biscoat 8FM, Biscoat 17FM" (all are fluorinated (meth) acrylic monomers manufactured by Osaka Organic Chemical Industry Co., Ltd.), perfluorocyclohexyl (meth) acrylate, Various fluorine-containing (meth) acrylates containing (per) fluoroalkyl group, vinyl esters containing (per) fluoroalkyl group, vinyl ethers containing (per) fluoroalkyl group, such as di-perfluorocyclohexyl fumarate ;

Various dialkyl esters of unsaturated dibasic acids, such as dimethyl malate, di-n-butyl malate, dimethyl fumarate, dimethyl itaconate and the like;

Ethylene, propylene, isobutylene, 1
Various α-olefins, such as butene;

Various alkyl vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, cyclohexyl vinyl ether and the like;

Various cyano group-containing monomers such as (meth) acrylonitrile;

Various unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, itaconic acid and maleic acid;

Various monoesters (half esters) of unsaturated dicarboxylic acids and saturated monohydric alcohols such as monomethyl itaconate, monomethyl maleate, mono-n-butyl maleate and the like;

Monovinyl esters of various saturated dicarboxylic acids, such as monovinyl adipate and monovinyl succinate;

Saturated polycarboxylic acid anhydrides such as succinic anhydride, glutaric anhydride, phthalic anhydride and trimellitic anhydride, and various hydroxyl group-containing vinyl monomers such as 2-hydroxyethyl (meth) acrylate. Various addition reaction products with the dimers;

Carboxyl group-containing monomers (unsaturated carboxylic acids, unsaturated dicarboxylic acids and saturated
Monoesters with polyhydric alcohols, monovinyl esters of saturated dicarboxylic acids, addition reaction products of anhydrides of saturated polycarboxylic acids with hydroxyl-containing vinyl monomers) and ε-caprolactone. Various addition reaction products with lactones such as

Various unsaturated polycarboxylic anhydrides such as maleic anhydride, itaconic anhydride and the like;

Various unsaturated monocarboxylic anhydrides such as acrylic acid anhydride and methacrylic anhydride;

Various mixed acid anhydrides of various unsaturated carboxylic acids such as (meth) acrylic acid and various saturated carboxylic acids such as acetic acid, propionic acid and benzoic acid;

Various isocyanate group-containing vinyl monomers such as 2-isocyanatoethyl (meth) acrylate;

2,3-carbonatepropyl (meth) acrylate, 3,4-carbonatebutyl (meth) acrylate, 4,5-carbonatepentyl (meth) acrylate, 5,6-carbonatehexyl (meth) acrylate, 2,3 -Cyclocarbonate group-containing monomers such as carbonate propyl vinyl ether;

Such as glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, glycidyl vinyl ether, allyl glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth) acrylate;
Various epoxy group-containing vinyl monomers;

Various hydrolyzable silyl group-containing groups such as 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, etc. Meth) acrylates;

Various hydrolyzable silyl group-containing vinyl monomers such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, allyltrimethoxysilane, 2- (trimethoxysilyl) ethyl vinyl ether and the like. ;

2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-di-n-propylaminoethyl (meth) acrylate, 3-dimethylaminopropyl (meth) acrylate, 4-dimethyl Various tertiary amino group-containing (meth) acrylates such as aminobutyl (meth) acrylate;

2-dimethylaminoethyl vinyl ether, 3-dimethylaminopropyl vinyl ether, 4-
Various tertiary amino group-containing vinyl ethers such as dimethylaminobutyl vinyl ether;

(Meth) acrylamide, N-methyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, Nn-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide,
Various (meth) acrylamides such as diacetone acrylamide;

N- [2- (dimethylamino) ethyl]
(Meth) acrylamide, N- [2- (di-n-propylamino) ethyl] (meth) acrylamide, N- [3
Various (tertiary) amino group-containing (meth) acrylamides such as-(dimethylamino) propyl] (meth) acrylamide, N- [4- (dimethylamino) butyl] (meth) acrylamide;

Various (meth) acryloyloxyalkyl acid phosphates such as 2- (meth) acryloyloxyethyl acid phosphate and diphenyl-2- (meth) acryloyloxyethyl phosphate, and dialkyl [(meth) acryloyloxyalkyl] Phosphates, and further, various phosphorus atom-containing vinyl monomers such as various (meth) acryloyloxyalkyl acid phosphites and dialkyl [(meth) acryloyloxyalkyl] phosphites.

The above-mentioned various tertiary amino group-containing alkyl (meth) acrylates and various phosphorus atom-containing vinyl monomers all impart an internal catalytic function to the vinyl copolymer. It is used in the case or when improving the adhesion to a material or a substrate, the dispersibility of a pigment, and the like, and these may be used alone or in combination of two or more.

For the purpose of further improving the weather resistance of the coating film performance, various benzotriazole-based acrylic monomers such as "RUVA-93" (manufactured by Otsuka Chemical Co., Ltd.); Various polymerizable light stabilizers such as various hindered amine-based acrylic monomers such as "LA-82 and ADK STAB LA-87" (both manufactured by Asahi Denka Kogyo Co., Ltd.) can be used. Yes, and furthermore, "AA-6, AS-6, AN-
6, AB-6, AA-714S "(all manufactured by Toagosei Chemical Industry Co., Ltd.) and other high molecular weight monomers (macromones or macromers having a functional group terminal capable of being copolymerized. ) Can also be used.

There is no problem to use a hydroxyl group-containing vinyl monomer other than the above-mentioned hydroxyl group-containing vinyl monomer (a) together to the extent that the effects of the present invention are not impaired. As the hydroxyl group-containing vinyl monomer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth)
Examples thereof include acrylate and 3-hydroxybutyl (meth) acrylate, and also include block-hydroxyl-containing vinyl monomers such as trimethylsiloxyethyl (meth) acrylate and triethylsiloxyethyl (meth) acrylate.

Further, various types of hydroxyl group-containing monomers (hydroxyl group-containing alkyl (meth) acrylates, hydroxyl group-containing vinyl monomers) and lactones represented by ε-caprolactone and the like can be used. Addition reaction products, for example,
"Placcel FA-1, Placcel FA-2, Placcel FM-1, Placcel FM-2, Placcel FM-4
X "(all of which are caprolactone-added monomers manufactured by Daicel Chemical Industries, Ltd.), and various hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids.

Further, the pigment dispersibility of the obtained vinyl copolymer is further improved, the content of nonvolatile components in coating is increased, or the solubility in organic solvents described later is improved. For the main purpose of causing the reaction to occur, resins containing a polymerizable unsaturated group can also be used.

Particularly typical examples of such polymerizable unsaturated group-containing resins include polyester resins, vinyl copolymers, and petroleum resins each containing a polymerizable unsaturated group. , Rosin esters, polyether polyols and the like. Among them, polyester resins (including oil-modified type) and vinyl copolymers are suitable.

The polyester resins and vinyl copolymers may be used alone or in combination of two or more, or one or more of these resins may be used in combination. Of course.

Further, if only particularly typical organic solvents used in the present invention are exemplified,

Toluene, xylene, ethylbenzene,
Various aromatic hydrocarbon solvents such as "Solvesso 100" (aromatic hydrocarbon solvent manufactured by Exxon Chemical Co., USA);

Various alcohol solvents such as isopropyl alcohol, 1-butanol, isobutanol and the like;

Various ester solvents such as ethyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate and the like;

Various cellosolve solvents such as ethyl cellosolve, butyl cellosolve and the like;

Various ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclohexanone and the like;

Such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-butyl ether acetate, and ethyl ethoxypropionate;
Various alkoxy group-containing esters;

"LAWS, HAWS" (both products of Shell, Netherlands), "Shellsol 70, Shellsol 71, Shellsol D-40, Shellsol D-7
0 "(all manufactured by Shell, The Netherlands)," IP Solvent 1016, IP Solvent 1620 "(all manufactured by Idemitsu Petrochemical Co., Ltd.)," A Solvent, K Solvent, LA Solvent "[all manufactured in Japan Petroleum Corporation products], “Exxon Naphtha No. 3, Exxon Naphtha No. 5, Exxon Naphtha No. 6” [all
Exxon Chemical, USA), "Exole D
30, Exol D40, Exol D60, Exol D70 "(all manufactured by Exxon Chemical Company, USA)," Isoper E, Isopar G, Isopar H "(all manufactured by Exxon Chemical Company, USA)
Aliphatic hydrocarbon solvents containing aliphatic hydrocarbons as a main component, or mixed aliphatic / aromatic hydrocarbon solvents;

Examples thereof include aliphatic hydrocarbon solvents such as n-hexane and n-heptane. These organic solvents can be used alone or in combination of two or more.

However, the use of alcohol-based solvents is limited to the aforementioned (meth) acrylate-based monomers, hydroxyl-containing vinyl-based monomers, glycidyl-group-containing monomers, and vinyl esters of monocarboxylic acids. When using dimers,
Since transesterification occurs between each of these monomers and the alcohol-based solvent and a desired copolymer cannot be obtained, use of only the alcohol-based solvent should be avoided.

In the radical polymerization of the vinyl monomer mixture in the method for producing a vinyl copolymer of the present invention, from the viewpoint of making it possible to further reduce the molecular weight dispersity of the resulting vinyl copolymer, The initiator represented by the following general formula (2) is preferable. R1-(CO) n -OO-C (CH3) 2 -R2 (2) wherein R1 is an alkyl group having 2 to 10 carbon atoms, an alkoxy group having 2 to 10 carbon atoms, a phenyl group or a benzyl group. R2 is an alkyl group having 2 to 5 carbon atoms, and n is 0
Or an integer of 1. )

Specific examples of the radical polymerization initiator represented by the general formula (2) include tert-amyl peroxy neodecanoate, tert-amyl peroxy-2-ethylhexanoate, and tert-amyl peroxy- n
Octoate, tert-amyl peroxy isononanoate, tert-amyl peroxybenzoate,
tert-hexyl peroxy neodecanoate, te
rt-hexylperoxy-2-ethylhexanoate, tert-hexylperoxy-n-octoate, tert-hexylperoxyisononanoate,
tert-hexyl peroxybenzoate, tert
-Heptyl peroxy neodecanoate, tert-heptyl peroxy-2-ethylhexanoate, t-heptyl peroxy-n-octoate, tert-heptyl peroxy isononanoate, tert-heptyl peroxy benzoate, di- Tert-amyl peroxide and the like can be mentioned. These radical polymerization initiators can be used alone or in combination of two or more.

Further, to the extent that the effects of the present invention are not impaired,
Other known and commonly used radical polymerization initiators can be used in combination. If only typical examples of the radical polymerization initiator are given,

Azobisisobutyronitrile, benzoyl peroxide, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyacetate, tert-butylperoxybenzoate, te
rt-butyl cumyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, ter
t-butyl hydroperoxide, 1,1-bis (te
rt-butylperoxy) cyclohexane and the like.

The reaction vessel used for producing such a vinyl copolymer is described in JP-B-63-30334.
The same ones as those used in the bulletin can be used. For example, an autoclave-type reaction vessel having a pressure-resistant structure (gauge pressure: 1.0 to 1.2 MPa) can be used. An autoclave having a mixture of the vinyl-based monomer and the radical polymerization initiator from the receiving tank for the mixture of the vinyl-based monomer and the receiving tank for the radical polymerization initiator in a predetermined time via a metering pump. It is intended to be supplied.

A method for producing a vinyl copolymer using such a reaction vessel may be the method described in JP-B-63-30334. For example, a well-prepared reaction vessel is replaced with nitrogen gas, and nitrogen gas is further discharged by a vacuum pump to maintain the degree of vacuum at 5 kPa to 10 kPa.
Next, a predetermined solvent or a mixture of the solvent and the vinyl monomer is supplied, and the temperature in the container is maintained at 140 to 200 ° C, preferably 150 to 180 ° C. The remaining vinyl monomer and the above-mentioned radical polymerization initiator are supplied to the reaction vessel in such a state for solution polymerization. In this case, the supply of the vinyl monomer and the radical polymerization initiator is performed for 2 to 10 hours. It takes place gradually. By maintaining the solution polymerization at a predetermined temperature for 1 to 10 hours after the completion of the supply to terminate the solution polymerization, the desired low-molecular-weight vinyl copolymer can be easily and safely produced.

The vinyl copolymer thus obtained has an extremely low number average molecular weight of 500 to 4,000 and a molecular weight dispersity expressed by weight average molecular weight / number average molecular weight of 1.0 to 2. .5 and small. Further, the copolymer solution obtained by the above-described method can be used as it is, but the organic solvent is removed by distillation under reduced pressure, and the copolymer solvent can be used as a resin for powder coating or a resin for toner as a copolymer solid. .

The vinyl copolymer obtained as described above is usually used in combination with a curing agent, but the vinyl copolymer can be self-cured.

As the curing agent, any one can be used as long as it reacts with the hydroxyl group contained in the vinyl copolymer. Typical examples of the curing agent that reacts with a hydroxyl group include an isocyanate compound, an amino resin, a polycarboxylic anhydride, an alkoxide of a polyvalent metal or a complex compound of a polyvalent metal. Is preferred from the viewpoints of weather resistance and solvent resistance of the coating film.

Among these isocyanate compounds, particularly representative ones include tolylene diisocyanate and diphenylmethane diisocyanate.
Various aromatic diisocyanates; various aliphatic diisocyanates such as hexamethylene diisocyanate or trimethylhexamethylene diisocyanate; various alicyclic diisocyanates such as isophorone diisocyanate;

The above-mentioned various diisocyanates, various polyhydric alcohols such as ethylene glycol, trimethylolethane or trimethylolpropane, and various polyether polyols such as polyethylene glycol or polypropylene glycol, etc. Adducts with polycaprolactone polyols having a functional group that reacts with isocyanate groups, relatively low molecular weight polyester resins (including oil-modified types), acrylic copolymers, and the like;

Alternatively, there are isocyanates having a burette structure; isocyanurate ring-containing isocyanates obtained by cyclizing diisocyanates; and isocyanates obtained by blocking isocyanates with a known and commonly used blocking agent.

Examples of typical commercially available isocyanates include "Varnock DN-950, Varnock DN-950"
980, Burnock DN-981, Burnock DN-9
92, Barnock D-550 "(all manufactured by Dainippon Ink and Chemicals, Inc.)," Duranate 24A-10
0, duranate THA-100, duranate TPA
-B80X "[all products manufactured by Asahi Kasei Corporation],
"Coronate HK, Coronate 2507"
Products of Nippon Polyurethane Urethane Industry Co., Ltd.] and "Takenate D-140N" [products of Takeda Pharmaceutical Co., Ltd.].

As described above, the amount of the isocyanate compound to be used is preferably 1 equivalent of the hydroxyl group of the vinyl copolymer according to the present invention in consideration of the curability of the obtained coating composition and the price of the coating. In the range where the isocyanate group becomes 0.2 to 1.5 equivalents, that is, OH /
The range where the equivalent ratio of NCO is 1 / 0.2 to 1 / 1.5 is preferable.

Particularly typical amino resins include, for example, an amino group-containing compound component such as melamine, urea, acetoguanamine or spiroguanamine, and an aldehyde compound component such as formaldehyde, paraformaldehyde or glyoxal. There are condensates obtained by reacting by a known and common method, or those obtained by etherifying each of these condensates with alcohol. Among them, those partially or completely etherified with alcohols having 1 to 4 carbon atoms are preferable.

Examples of typical commercially available amino resins include "Super Beckamine L-117-60 and Super Beckamine L-127-60" (both are products of Dainippon Ink and Chemicals, Inc.), Various butyl etherified melamine resins such as "Uban 120" (product of Mitsui Chemicals, Inc.); "Super Beckamine L-105-60"
[Products of Dainippon Ink and Chemicals, Inc.], "Symel 30
And various methyl etherified melamine resins, such as “0, Cymel 303” (product of Mitsui Cytec Co., Ltd.);
There are various methyl / butyl mixed etherified melamine resins.

The amino resin is used in an amount of 5 to 1 based on 100 parts by weight of the vinyl copolymer.
The amount is preferably in the range of 00 parts by weight, more preferably in the range of 10 to 60 parts.

Further, when the coating composition according to the present invention is used, room temperature drying, forced drying, heat drying (baking), and when an isocyanate compound is used,
The method can be applied to any curing means or curing conditions such as a method of curing in an amine stream, that is, a vapor cure system or a VIC system.

Also, the coating composition of the present invention generally contains a pigment dispersing agent, a leveling agent, an ultraviolet absorber, a light stabilizer or a curing accelerator other than those described above. Various paint additives, such as those commonly known and used, can be used.

As long as it is soluble in organic solvents used in the coating composition of the present invention, other resins such as plasticizers can be used for the purpose of improving the performance. For example, appropriately using acrylic copolymers, cellulose compounds, organic silicate compounds, acrylated alkyd resins, alkyd resins, silicone resins, fluororesins or epoxy resins, as appropriate. However, at this time, they can be used within a range not to deviate from the object of the present invention or within a range that does not impair the effects of the present invention.

The coating composition of the present invention can be used as a so-called enamel coating by mixing with pigments and kneading the mixture, or by mixing dispersed pigments or processed pigments. Or without using such pigments,
It can also be used as a so-called clear paint.

The coating composition of the present invention obtained as described above is formed into a coating material by a conventional method, and is mainly applied to the following objects to be coated (substrates).

That is, if only typical examples of the above-mentioned base materials are given as examples, aluminum,
There are various metal materials or metal products such as stainless steel, chrome plating, galvanized sheet, tin plate, etc .; roof tiles; glass; various inorganic base materials and the like. In addition to automobile parts, motorcycles or motorcycle parts, various building materials such as gates and fences; various building interior and exterior materials such as aluminum sash; ceramic inorganic building materials; various types of aluminum wheels Materials or products of ferrous or non-ferrous metals.

For the coating at that time, various known and commonly used means such as spray, brush or roller can be used.

[0089]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference examples, examples and comparative examples.
The invention is in no way limited to these examples only. In the following, all parts and percentages are by weight unless otherwise specified.

Reference Example 1 A 5-liter autoclave having a pressure-resistant structure constituted by a stirrer, a thermometer, a nitrogen gas inlet tube, a heating and cooling jacket, and a cooling coil was used as a main reaction vessel. Using a metering pump for quantitatively supplying the monomer mixture and a metering pump for quantitatively supplying the radical polymerization initiator mixture, and a device having a vacuum pump for removing gas remaining in the container as an auxiliary equipment, First, 250 parts of xylene is charged into an autoclave as an initial reaction charge, and heated from a jacket to set the temperature in the reaction vessel to 160 ° C. and to maintain the temperature.

Next, 150 parts of styrene, 100 parts of methyl methacrylate, ter
484 parts of t-butyl methacrylate, 6 parts of n-butyl acrylate, 255 of 4-hydroxybutyl acrylate
Of xylene, 85 parts of xylene, 50 parts of di-tert-amyl peroxide and tert-amyl peroxy-2
After continuously supplying a mixed solution of a radical polymerization initiator consisting of 20 parts of ethylhexanoate by a metering pump for 5 hours, the temperature in the reaction vessel is kept at 160 ° C., and the reaction is continued for 3 hours to complete the reaction.

As described above, the solid content concentration is 75%, the Gardner viscosity (25 ° C .; the same applies hereinafter), the number average molecular weight is 1,600, the weight average molecular weight is 3,300, and the molecular weight dispersity (weight average) (Molecular weight / number average molecular weight; the same applies hereinafter)) to obtain a vinyl copolymer solution having a molecular weight of 2.06. This vinyl copolymer solution is abbreviated as (A-1).

REFERENCE EXAMPLE 2 Using the same reaction vessel and accessory equipment as in Reference Example 1, 150 parts of styrene, 100 parts of methyl methacrylate and 100 parts of tert-butyl methacrylate
02 parts, 192 parts of n-butyl acrylate, (4-hydroxymethylcyclohexyl) -methyl acrylate 3
By performing the same operation as in Reference Example 1 except that the mixture was changed to a mixture of 51 parts and 5 parts of methacrylic acid, the solid content concentration was 75%, the Gardner viscosity was X, and the number average molecular weight was 1,
A vinyl copolymer solution having a weight average molecular weight of 3,200 and a molecular weight dispersity of 2.13 was obtained. This vinyl copolymer solution is abbreviated as (A-2).

REFERENCE EXAMPLE 3 Using the same reaction vessel and accessory equipment as in Reference Example 1, 150 parts of styrene, 100 parts of methyl methacrylate and 100 parts of tert-butyl methacrylate
33 parts, n-butyl acrylate 62 parts, 4-hydroxybutyl acrylate 204 parts, β-hydroxyethyl methacrylate 46 parts and methacrylic acid 5 parts Solids concentration 75%, Gardner viscosity WX,
The number average molecular weight is 1,700 and the weight average molecular weight is 3,40
A vinyl copolymer solution having a molecular weight dispersity of 0 and a molecular weight dispersity of 2.00 was obtained. This vinyl copolymer solution is abbreviated as (A-3).

REFERENCE EXAMPLE 4 Using the same reaction vessel and auxiliary equipment as in Reference Example 1, 200 parts of styrene, 150 parts of methyl methacrylate, 398 n-butyl methacrylate were added to a mixture of vinyl monomers.
Parts, a mixture of 82 parts of 2-ethylhexyl acrylate, 155 parts of 4-hydroxybutyl acrylate and 15 parts of methacrylic acid, the same operation as in Reference Example 1 was carried out to obtain a solid concentration of 75% and a Gardner viscosity. Was U, the number average molecular weight was 1,700, the weight average molecular weight was 3,500, and the vinyl copolymer solution having a molecular weight dispersity of 2.06 was obtained. This vinyl copolymer solution was (A-
Abbreviated as 4).

Reference Example 5 Using the same reaction vessel and auxiliary equipment as in Reference Example 1, 150 parts of styrene, 100 parts of methyl methacrylate, and tert-butyl methacrylate 2
The same operation as in Reference Example 1 was carried out except that the mixture was changed to a mixture of 29 parts, 286 parts of n-butyl acrylate, 230 parts of β-hydroxyethyl methacrylate and 5 parts of methacrylic acid. A vinyl copolymer solution having a viscosity of Z1, a number average molecular weight of 1,500, a weight average molecular weight of 3,300 and a molecular weight dispersity of 2.20 was obtained. This vinyl copolymer solution was (A-
Abbreviated as 5).

Reference Example 6 Using the same reaction vessel and auxiliary equipment as in Reference Example 1, 85 parts of a mixture solution of a radical polymerization initiator was mixed with 85 parts of xylene and di-t
tert-butyl peroxide 50 parts and tert-
The same operation as in Reference Example 1 was carried out except that the mixture solution was changed to a mixture solution of butyl peroxy-2-ethylhexanoate 20 parts, whereby the solid content concentration was 75%, the Gardner viscosity was ZZ1, and the number average molecular weight was Was 1,600, the weight average molecular weight was 5,200, and the molecular weight dispersity was 3.25. Thus, a vinyl copolymer solution was obtained. This vinyl copolymer solution was (A-
Abbreviated as 6).

REFERENCE EXAMPLE 7 Using the same reaction vessel and accessory equipment as in Reference Example 1, 150 parts of styrene, 100 parts of methyl methacrylate, and tert-butyl methacrylate 2
29 parts, 286 parts of n-butyl acrylate, 230 parts of β-hydroxyethyl methacrylate and 5 parts of methacrylic acid, and a mixture solution of a radical polymerization initiator, 85 parts of xylene, 50 parts of di-tert-butyl peroxide and A solid content concentration of 75%, a Gardner viscosity of Z3, and a number average molecular weight were obtained by performing the same operation as in Reference Example 1 except that the mixture solution was changed to a mixture solution of 20 parts of tert-butylperoxy-2-ethylhexanoate. Was 1,500, the weight average molecular weight was 5,000, and the molecular weight dispersity was 3.33. This vinyl copolymer solution is abbreviated as (A-7).

REFERENCE EXAMPLE 8 Using the same reaction vessel and auxiliary equipment as in Reference Example 1, 200 parts of styrene, 150 parts of methyl methacrylate, and 199 parts of n-butyl methacrylate were mixed with a vinyl monomer mixture.
Parts, a mixture of 296 parts of 2-ethylhexyl acrylate, 140 parts of β-hydroxyethyl methacrylate and 15 parts of methacrylic acid, and a mixed solution of a radical polymerization initiator in 85 parts of xylene, 50 parts of di-tert-butyl peroxide and tert. -Butyl peroxy-
A solid content concentration of 75%, a Gardner viscosity of Y, a number average molecular weight of 1,600, and a weight were obtained by performing the same operation as in Reference Example 1 except that the mixture solution was changed to a mixture solution of 20 parts of 2-ethylhexanoate. A vinyl copolymer solution having an average molecular weight of 5,100 and a molecular weight dispersity of 3.19 was obtained. This vinyl copolymer solution is abbreviated as (A-8).

Examples 1 to 4 and Comparative Examples 1 to 4 The vinyl copolymer solutions obtained in Reference Examples 1 to 8 were blended according to the blending composition shown in Table 1 and further they were mixed with Solvesso 100 Cup / No. / n-butyl acetate = 50/50 mixed solvent. 4 for 20 seconds (2
(5 ° C.) was spray-coated on a zinc phosphate-treated dull steel sheet so as to have a dry film thickness of 30 μm.

[0101]

[Table 1]

[Footnotes to Table 1] All the numerical values of the composition in the tables represent parts (by weight). * 1) "Barnock DN-980": [isocyanate compound manufactured by Dainippon Ink and Chemicals, Inc.] * 2) "Super Beckamine L-117-60": [melamine manufactured by Dainippon Ink and Chemicals, Inc.] * 3) Chemisorb 74: [Ultraviolet absorber manufactured by Chemipro Kasei Co., Ltd.] * 4) Sanol LS-765: Light stabilizer manufactured by Sankyo Co., Ltd.

Next, in the case of Examples 1 to 3 and Comparative Examples 1 to 3, the cured coating film obtained by being left to dry at room temperature for 2 weeks was used. In the case of Example 4, various properties of the cured coating film obtained by baking and drying at 140 ° C. for 30 minutes were evaluated (Table 2). Also,
Table 2 also shows the coating non-volatile content of various paints.

[0104]

[Table 2]

[Evaluation Tests of Various Properties of Various Coating Films and Various Coating Materials] (1) Accelerated weathering resistance: (Sunshine weatherometer test: 2000-hour test (60 ° mirror reflectance / 60 ° mirror reflectance before test) ) × 100 gloss retention (%)

(2) Solvent resistance Visual evaluation of the coating film appearance by a rubbing tester (felt contains xylene as a solvent and 30 reciprocations under a load of 1,500 g) ：: No change in coating film △: Slight whitening of coating film × : Coating whitening

(3) Non-volatile content of paint 4 for 20 seconds (25 ° C)
Solids concentration (%) when diluted so that

[0108]

Industrial Applicability The method for producing a vinyl copolymer of the present invention and its coating composition are extremely practical, having low viscosity and excellent weather resistance and solvent resistance.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4J011 AA05 AB02 DA04 DB12 HA03 HB02 HB14 HB22 4J038 CB001 CC001 CD001 CE001 CF001 CG141 CG171 CL001 DA112 DA142 DA162 DA172 DG191 DG271 DG281 DG291 DG301 GA03 KA03 LA02 MA14 NA15 NA03 NA04 PC02 PC03 PC04 4J100 AA02P AA03P AA04P AA06P AB02P AB03P AB04P AC03P AC04P AC23P AC24P AE02P AE04P AE09P AE18P AG02P AG04P AG08P AJ01P AJ02P AJ08P AJ09P AK31P AL03P AL04P AL05P AL08P AL08Q AL09Q AL10P AL34P AL36P AL44P AM02P AM17P AM19P AM21P AP16P BA03Q BA04P BA05P BA16P BA22P BA31P BA42P BA65P BA66P BA77P BB07P BC04P BC04Q BC07P BC43P BC54P CA03 CA04 CA05 CA06 DA01 DA04 FA03 FA19 FA28 JA01

Claims (7)

[Claims] 1. In a closed reaction vessel maintained at a temperature of 140 to 200 ° C. in a vessel, in the presence of an organic solvent, the following general formula (1): CH 2 ＣＲCR 1 —CO—O—R 2 —CH 2 —OH (1) (Wherein, R1 is hydrogen or a methyl group, and R2 is
To 9 hydrocarbon groups. A) a mixture of 5 to 50% by weight of a hydroxyl group-containing vinyl monomer (a) represented by the formula (1) and 50 to 95% by weight of another copolymerizable vinyl monomer (b) using a radical polymerization initiator. And producing a vinyl copolymer solution having a number average molecular weight of 500 to 4,000 by copolymerization. 2. A radical polymerization initiator represented by the following general formula (2): R 1-(CO) n -OO-C (CH 3) 2 -R 2 (2) wherein R 1 is an alkyl having 2 to 10 carbon atoms. R2 is an alkyl group having 2 to 5 carbon atoms, and n is an integer of 0 or 1). A method for producing the vinyl copolymer according to claim 1. 3. The weight average molecular weight / number average molecular weight of the vinyl copolymer is from 1.0 to 2.5.
A method for producing the vinyl copolymer according to claim 1. 4. A vinyl copolymer obtained by the production method according to claim 1. 5. A coating composition comprising a vinyl copolymer obtained by the production method according to claim 1 and a curing agent. 6. The coating composition according to claim 5, wherein the curing agent is an isocyanate compound and / or an amino resin. 7. A coated article to which the coating composition according to claim 5 is applied.