JPH0673336A - Production of resin for automotive repair coating material - Google Patents

Abstract

PURPOSE:To obtain the subject resin which can give a coating film excellent in gloss, driability, build, etc. by effecting the addition reaction of an epoxy vinyl copolymer of a specified composition with a specified amount of a drying oil fatty acid of a specified iodine value. CONSTITUTION:5-25wt.% epoxy vinyl monomer (e.g. glycidyl acrylate) is copolymerized with 1-60wt.% aromatic vinyl monomer (e.g. styrene), 0.1-10wt.% alkyd resin containing a copolymerizable unsaturation and 5-93.9wt.% (the total being 100wt.%) other vinyl monomers (e.g. methyl acrylate) copolymerizable therewith. The addition reaction of 100 pts.wt. obtained epoxy vinyl copolymer with 5-60 pts.wt. drying oil fatty acid of an iodine value of 100-200 (e.g. cotton seed oil) is effected to obtain the objective resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel and useful process for producing a resin for automobile repair paint. More particularly, the present invention relates to a process for making vinyl copolymers modified with certain drying oil fatty acids.

[0002]

2. Description of the Related Art At present, paints for repairing automobiles include lacquer-based paints that do not contribute to crosslinking and urethane-based paints that contribute to crosslinking. Of these, urethane-based paints are curable. Therefore, the demand for coatings is increasing, regardless of whether they are for topcoats or undercoats because of their excellent coating performance.

However, contrary to the good coating performance, this urethane type is not generally quick-drying,
In addition, depending on the solvent used, the old paint film (existing paint film) that has already been applied, or the top coat and the base coat, when used in a certain combination, provides a lacquer-based primer surfacer. When the car repair coating is performed, it is an important know-how to prevent the repair coating from failing because it may erode and cause blemishes and lifting, and what kind of old coating film it is. There is.

Therefore, the advent of coating materials for automobile repair coatings, which are less likely to cause blemishes and lifting in old coating films, has become an urgent need in the industry. By the way, lacquer-based paints have long been used as automotive repair paints, and although they are quick-drying and easy to use, coating performance, gloss or appearance are inferior to urethane-based paints, and they are not suitable for crosslinking. As a result, the coating film performance is inferior to that of the urethane type one.

Therefore, it is desired to develop a coating system capable of compensating for the defects of both the lacquer system and the urethane system. Apart from this, a method of adding a drying oil fatty acid to an epoxy group-containing acrylic copolymer to obtain an air-curable resin has already been disclosed in British Patent No. 767476.
JP-A Nos. 53-51232 and 53-53, which are disclosed in Japanese Patent No. 53-51232 and have been proposed to solve the drawback that the resin obtained by such a method has insufficient gloss due to insufficient wetting of the pigment. It can be said that this is an improved method as described in Japanese Patent Publication No. 99231.

However, each of the above-mentioned respective improvement methods is a method in which a drying oil fatty acid is added to a glycidyl group in an acrylic resin and then esterified with a dicarboxylic acid anhydride such as tetrahydrophthalic acid anhydride. From the process, (1) production of an acrylic copolymer,
(2) extension of the total reaction time comprising three steps of modification by addition of a drying oil fatty acid to the copolymer, and (3) esterification of the fatty acid modified copolymer with dicarboxylic acid anhydride, It is not a preferable method because it complicates the reaction control and increases the production cost.

[0007]

However, in view of the above-mentioned circumstances, the present inventors have proposed a simpler method,
In order to obtain a drying oil fatty acid-modified vinyl copolymer that has good wettability for pigments and excellent gloss, in addition, by using the modified copolymer, it is fast-drying and has a glossy feel. In addition, it has been earnestly studied and sought for a method for preparing a drying oil fatty acid vinyl copolymer for an automobile repair coating which is hard to attack a base coating or an old coating, and has completed the present invention. .

[0008]

That is, the present invention basically comprises 5 to 25% by weight of an epoxy group-containing vinyl monomer, 1 to 60% by weight of an aromatic vinyl monomer, and a copolymerizable unsaturated monomer. Alkyd resin having a bond of 0.1 to
10% by weight and 5 to 93.9% by weight of vinyl monomers copolymerizable therewith are copolymerized, and then 100% of the epoxy group-containing vinyl copolymer thus obtained.
A method for producing a dry oil fatty acid-modified vinyl copolymer for automobile repair paint, which comprises subjecting a dry oil aliphatic having an iodine value of 100 to 200 to a weight ratio of 5 to 60 parts by weight for addition reaction. It is the one we are trying to provide.

Here, the iodine value is 100.
Typical examples of the dry oil fatty acid of ~ 200 are fatty acids of natural oils and fats such as cottonseed oil, soybean oil, rice sugar oil, dehydrated castor oil, linseed oil, tall oil or Chinese tung oil, and "heidiene", " Heidien H ”,“ Higen S ”,“ S
"K-conjugated fatty acid # 20" [above, product of Soken Chemical Industry Co., Ltd.] or "PAMOLYN 200, 300"
Synthetic dry oil fatty acids such as (product of Hercules, Inc. in the United States) can be used alone or in admixture at an arbitrary ratio, and in order to adjust the iodine value of the fatty acid system, it may be used depending on the case. Is a fatty acid having an iodine value of less than 100, such as coconut oil fatty acid, castor oil fatty acid, octylic acid, lauric acid, "versatic acid" (synthetic drying oil fatty acid manufactured by Ciel Co., Netherlands), stearic acid or hydroxystearic acid. It is needless to say that the saturated fatty acid can be used as a mixture with the drying oil fatty acid as described above, as long as it is within the range that does not impair the air drying property of the resulting modified vinyl copolymer (A). .

The amount of the dry oil fatty acid as described above is 5 to 60 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the epoxy group-containing vinyl copolymer. is there. If the amount used is less than 5 parts by weight, the target modified copolymer (A) will be poor in air-curing property, and the coating film will not have a sufficient three-dimensional structure. On the other hand, when the amount exceeds 60 parts by weight, yellowing is likely to occur and the weather resistance is also deteriorated, and as a result, crosslinking of the resulting coating film proceeds too much. Flexibility is impaired, resulting in a brittle coating film, which cannot be put to practical use.

Next, the above-mentioned epoxy group-containing vinyl copolymer will be described. First, typical examples of the epoxy group-containing vinyl monomer are glycidyl (meth) acrylate and β-methylglycidyl (meth).
Acrylic or (meth) allyl glycidyl ether, unsaturated mono- or dicarboxylic acids such as (meth) acrylic acid, fumaric acid, maleic acid or itaconic acid, or monoesters of such unsaturated dicarboxylic acids and monohydric alcohols Α, β-ethylenically unsaturated carboxylic acids such as “HOA-MP” or “HO
A-HS "[above, a carboxyl group-containing acrylic monomer manufactured by Osaka Organic Chemical Co., Ltd.], or a carboxyl group-containing compound, or mono-2- (meth) acryloyloxyethyl phthalate or 2-hydroxyethyl (meth)
Hydroxyl group-containing vinyl monomers such as acrylate, 2-hydroxypropyl (meth) acrylate or di-2-hydroxyethyl fumarate, and maleic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, benzenetricarboxylic acid, "hymic acid" [ Hitachi Chemical Co., Ltd.], polycarboxylic acid (anhydride) such as todecynyl succinic acid, succinic acid or tetrachlorophthalic acid
A variety of unsaturated carboxylic acids such as adducts obtained by equimolar addition reaction with "Epichlorohydrin 20
0, 400, 441, 850 Mokushi 1050 "[epoxy resin manufactured by Dainippon Ink and Chemicals, Inc.]," Epicoat 828, 1001 or 1004 "(epoxy resin manufactured by Ciel)," Araldite 6071 or 6 "
084 "(epoxy resin manufactured by Ciba-Geigy in Switzerland)," Chissonox 221 "[epoxy compound manufactured by Chisso Corporation] or" Denacol EX-810 "[epoxy compound manufactured by Nagase & Co., Ltd.]. , An epoxy group-containing polymerizable compound obtained by addition-reacting various polyepoxy compounds having at least two epoxy groups in one molecule at an equimolar ratio, and these may be used alone or in combination of two or more. Although they can be used as a mixture, they have relatively low molecular weights such as glycidyl (meth) acrylate and β-methylglycidyl (meth) acrylate in consideration of reactivity, number of reaction steps, viscosity or price of final product. Type of monomer is the easiest to use.

The epoxy group-containing vinyl monomer is 5 to
It is used in an amount of 25% by weight, but since the epoxy group in the monomer is involved in the reaction with the drying oil fatty acid as described above, the amount of the monomer used is mainly the amount of the drying oil fatty acid used. Needless to say, it should be determined depending on the reaction amount, and it is usually used in such a ratio that the epoxy group is in the range of 1.0 to 1.25 equivalents per equivalent of the drying oil fatty acid carboxyl group. It is preferable from the viewpoint of speed and the point that the adverse effect of the residual carboxyl groups on the coating film can be prevented.

The above-mentioned alkyd resin having a copolymerizable unsaturated bond is not limited to titanium oxide and pigments having a small oil absorption, such as sesame, and is particularly quinacridone-based.
It is used when it is desired to improve the dispersibility of an organic pigment such as a phthalocyanine-based or azo-based pigment or a pigment having a relatively large oil absorption amount such as carbon black, which has a poor dispersibility. It can be said that the alkyd resin does not contribute much to the coating performance itself.

As the alkyd resin, any of oil- or fatty-acid-modified resins and so-called oil-free alkyd resins which are not modified by these are used. In the present invention, among these alkyd resins, In particular, the type having an unsaturated bond copolymerizable with each vinyl monomer is suitable in the present invention.

Examples of the alkyd resin include octyl acid,
Saturated fatty acids such as lauric acid, stearic acid or "versatidic acid"; unsaturated fatty acids such as oleic acid, linoleic acid, linoleic acid, eleostearic acid or ricinoleic acid; "Pamoleen 200, 300", Chinese tung oil (fatty acid) , Linseed oil (fatty acid), dehydrated castor oil (fatty acid), tall oil (fatty acid), cottonseed oil (fatty acid),
(Semi) drying oil (fatty acid) such as soybean oil (fatty acid), olive oil (fatty acid), safflower oil (fatty acid), castor oil (fatty acid) or rice sugar oil (fatty acid) or hydrogenated coconut oil (fatty acid), or Ethylene glycol, propylene glycol, with or without one or a mixture of two or more oils or fatty acids such as non-drying oils (fatty acids) such as coconut oil (fatty acids) or palm oil (fatty acids)
One or more polyhydric alcohols such as glycerin, trimethylolethane, trimethylolpropane, neopentyl glycol, 1,6-hexanediol, 1,2,6-hexanetriol, pentaerythritol or sorbitol, and benzoin Acid, pt-butylbenzoic acid, (anhydrous) phthalic acid, hexahydro (anhydrous)
Phthalic acid, tetrahydro (anhydrous) phthalic acid, phthalic acid,
Tetrachloro (anhydrous) phthalic acid, hexachloro (anhydrous)
Phthalic acid, tetrabromo (anhydrous) phthalic acid, trimellitic acid, "hymic acid", (anhydrous) succinic acid, (anhydrous)
One or more carboxylic acids such as maleic acid, (anhydrous) itaconic acid, fumaric acid, adipic acid, sebacic acid or oxalic acid may be added by a conventional method and, if necessary,
Monoepoxy compounds such as glycidyl esters of fatty acids such as "Cardura E" (product of Ciel), "Epiclon 200, 400", "Epicote 828, 100"
1 "or a polyepoxy compound, or a diisocyanate such as tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or 4,4'-methylenebis (cyclohexyl isocyanate), each of these diisocyanates and the above polyhydric alcohols and water. Of polyisocyanates or diisocyanates obtained by the addition reaction of (co)
It is suitable to use one or more polyisocyanates having an isocyanuric ring obtained by polymerization, which are obtained by substituting a part of the above-mentioned polyhydric alcohols and carboxylic acids and reacting by a conventional method.

At this time, as the alkyd resin, a saturated fatty acid or a non-drying oil (fatty acid) modified type having no or less copolymerizable unsaturated bonds, or an oil-free alkyd resin not modified with an oil or a fatty acid is used. For those types, the copolymerizable unsaturated bond to be the grafting point of each other vinyl monomer,
Needless to say, it is necessary to introduce the unsaturated carboxylic acid such as (anhydrous) maleic acid or fumaric acid into the alkyd resin.

If the amount of the alkyd resin thus obtained to be used is within the range of not more than 10% by weight, that is the lower limit of the trace amount of 0.1% by weight. The amount may be, and preferably within the range of 1 to 5% by weight, but anyway, 10
When it is used in an excessively large amount exceeding the weight percentage, the solvent resistance and stain resistance are inferior. Moreover,
At the time of polymerization, the carboxyl group in the alkyd resin and the epoxy group in the epoxy group-containing vinyl monomer react with each other to cause gelation. If it is less than the above, the effect of improving the dispersibility of the pigment having a relatively large oil absorption, that is, the effect of improving the pigment dispersibility cannot be expected.

Therefore, the amount of the alkyd resin used is within the above-mentioned range, and is usually 0.1 to prevent gelation due to reaction between these groups.
Within the range of 10% by weight, preferably within the range of 1 to 5% by weight, it is appropriate that the amount of oxidation, oil length, amount of copolymerizable unsaturated bond and molecular weight of the alkyd resin are within the range. It is preferable to determine the molecular weight of the resulting modified copolymer (A) in consideration.

Next, styrene, α-methylstyrene, pt-butylstyrene, vinyltoluene and the like are typical examples of the above-mentioned aromatic vinyl monomer. Among them, styrene is more expensive. Is most preferable.
When the aromatic vinyl monomer is used in a large amount exceeding 60% by weight, the resulting coating film has poor weather resistance and is unsuitable as an outdoor coating resin. When it is used, it should be appropriately determined within 60% by weight, preferably within a range of 1 to 60% by weight, depending on the required performance such as gloss, feeling of feeling and weather resistance. From the viewpoint of the balance of gloss, texture, leveling property, weather resistance, etc., it is preferably in the range of 10 to 50% by weight.

Further, typical examples of the above-mentioned epoxy group-containing vinyl monomer, aromatic vinyl monomer and other vinyl monomer copolymerizable with the alkyd resin having a copolymerizable unsaturated bond will be given. , Methyl (meth) acrylate, ethyl (meth) acrylate,
n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate,
i-Butyl (meth) acrylate, t-butyl (meth)
Of acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, dibromopropyl (meth) acrylate, tribromophenyl (meth) acrylate or alkoxyalkyl (meth) acrylate Various (meth) acrylates such as; diesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid or itaconic acid with monohydric alcohols; vinyl acetate, vinyl benzoate or "veova"
Vinyl esters such as (vinyl ester manufactured by Ciel); "Biscoat BF, BFM, 3F or 3FM"
[Fluorine-containing acrylic monomer manufactured by Osaka Organic Chemical Co., Ltd.], perfluorocyclohexyl (meth) acrylate, diperfluorocyclohexyl fumarate or N
-(Propyl) fluoroalkyl group-containing vinyl esters such as i-propyl perfluorooctane sulfonamide ethyl (meth) acrylate, vinyl ethers,
Fluorine-containing compounds such as (meth) acrylates or unsaturated carboxylic acid esters; or olefins such as (meth) acrylonitrile, vinyl chloride, vinylidene chloride, vinyl fluoride or vinylidene fluoride.

Typical examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, di Hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids such as 2-hydroxyethyl fumarate, mono-2-hydroxyethyl-monobutyl fumarate or polyethylene glycol mono (meth) acrylate; (meth) acrylic acid Unsaturated monomers such as crotonic acid, maleic acid, fumaric acid, itaconic acid or citraconic acid or dicarboxylic acids, and α, β-ethylenically unsaturated carboxylic acids such as monoesters of these dicarboxylic acids and monohydric alcohols. Acid; α above Adducts of .beta.-unsaturated carboxylic acid hydroalkyl esters with various polycarboxylic acids (anhydrides) as described above, and monovalent compounds such as "Cardura E", coconut oil fatty acid glycidyl ester or octyl acid glycidyl ester. Monoglycidyl esters of carboxylic acids or monoepoxy compounds and adducts such as butyl glycidyl ether, ethylene oxide or propylene oxide; or methylol group-containing compounds such as N-methylol acrylamide or hydroxyethyl vinyl ether can also be used, For monomers containing a functional group such as a vinyl monomer, it is of course necessary to determine the amount used so as not to cause gelation, and the hydroxyl group in the hydroxyl group-containing vinyl monomer and the (β- Methyl) glycidyl ( The amount should be determined so that gelation due to reaction with the (β-methyl) glycidyl groups in the (meth) acrylate does not occur.

The drying oil fatty acid-modified vinyl copolymer thus obtained may be blended with various components such as the cellulose derivative (B), which is usually used for paints, as shown below. However, nitrocellulose, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, methyl cellulose, ethyl cellulose, benzyl cellulose or the like can be used as the cellulose derivative.

The cellulose derivative may be used when it is necessary to further improve the drying property, the gasoline resistance and the adhesion property, and the amount used is 40% by weight or less, preferably 30% by weight. The following are suitable and do not prevent the combined use of known and commonly used plasticizers such as dibutyl phthalate or dioctyl phthalate, if desired. This usage is 40% by weight
If it exceeds, the stain resistance, water resistance, moisture resistance and the like will be conspicuously deteriorated, which is not preferable.

The above-mentioned ultraviolet absorber (C) is a component used when it is necessary to further improve the durability of the above-mentioned drying oil fatty acid-modified resin, and if added and mixed each time. However, in that case, it may be used within a range of 0 to 10% based on the total weight of the modified copolymer (A) and the cellulose derivative (B). If the amount used exceeds 10% and is used in a large amount, the effect is great, but on the other hand, the water resistance is lowered and the cost is often disadvantageous.

Typical examples of the ultraviolet absorber (C) are benzophenone, 2,4-dihydrobenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone and 2-hydroxy-4-methoxybenzophenone. , 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxybenzophenone, 2-hydroxy-4-octoxybenzophenone,
2-hydroxy-4-dodecyloxybenzophenone, 2
-Hydroxy-4-methoxy-5-sulfobenzophenone, 5-chloro-2-hydroxybenzophenone, 2,
2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2-hydroxy-4-methoxy-
2'-carboxybenzophenone, 2-hydroxy-4
-(2-hydroxy-3-methyl-acryloxyisopropoxybenzophenone; 2- (2'-hydroxy-
5'-methyl-phenyl) -benzotriazole, 2-
(2-Hydroxy-3,5-di-t-amyl-phenyl) -2H-benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-amyl-phenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-
Di-t-butyl-5'-methyl-phenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-
t-butyl-phenyl) -5-chloro-benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-
Isoamyl-phenyl) benzotriazole, (2-hydroxy-5-t-butylphenyl) benzotriazole; phenyl salicylate, 4-t-butyl-phenyl salicylate, p-octyl-phenyl salicylate;
Ethyl-2-cyano-3,3'-diphenyl-acrylate, 2-ethylhexyl-2-cyano-3,3'-diphenyl-acrylate; hydroxy-5-methoxy-
Acetophenone, 2-hydroxy-naphthophenone; 2
-Ethoxyethyl-p-methoxycinnamate; nickel-bisoctylphenyl sulfide; 4-benzoyloxy-2,2,6,6-tetramethylpiperidine,
Examples thereof include bis- (2,2,6,6-tetramethyl-4-piperidyl) sebacate and “Tinuvin 292” (manufactured by Ciba Geigy), and these may be used alone or in combination of two or more kinds.

Further, in order to increase the effectiveness, or "Sumilyzer BHT" (a product of Sumitomo Chemical Co., Ltd.),
"Seanox BCS" [Product of Shiraishi Calcium Co., Ltd.], "Irganox 1010 or 1076"
(Product of Ciba-Geigy), "Noclizer TNP"
[Ouchi Shinko Co., Ltd. product] or "Antioxidant K"
It is also possible to use well-known conventional antioxidants such as "B" (product of Bayer, West Germany).

Next, the above-mentioned dryer (D) may be any of those commonly used for paints. Among them, particularly typical ones are cobalt, vanadium, manganese, cerium, lead,
Iron, calcium, zinc, zirconium, cerium, naphthenates such as nickel or tin, octylates or resinates are used. It may be appropriately determined according to the combination or the required performance.

In this case, a small amount of organic peroxide such as benzoyl peroxide, methyl ethyl ketone peroxide or t-butyl perbenzoate may be used in combination to enhance the effect of using the dryer. Further, known and commonly used additives for coating materials such as pigment dispersants or leveling agents can also be used in combination.

Further, typical examples of the above-mentioned polyisocyanate (E) include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate or diphenylmethane diisocyanate; tetramethylene diisocyanate, hexamethylene diisocyanate or trimethylhexamethylene diisocyanate. Aliphatic diisocyanate; or isophorone diisocyanate, methylcyclohexane-
2,4- (or 2,6-) diisocyanate, 4,
4'-methylenebis (cyclohexyl isocyanate)
Alternatively, diisocyanates such as alicyclic diisocyanates such as 1,3-di (isocyanatomethyl) cyclohexane, or each of these diisocyanates and the above polyhydric alcohols, and low molecular weight polyesters having a functional group that reacts with an isocyanate group Resins (including oil-modified types), acrylic copolymers (including those containing styrene as a comonomer component) or adducts with water, and further burettes or the above-mentioned diisocyanates (copolymers). ) Polymers (including oligomers).

By the way, in using the polyisocyanate, use of aromatic diisocyanates or their derivatives, which are yellowed or cracked by ultraviolet rays, is unsuitable for topcoating, and the weather resistance is exclusively used. It is suitable for primer surfacer, chassis black, or undercoating such as chipping resistant paint that does not require much. Therefore, in such a case, an aliphatic diisocyanate or an alicyclic diisocyanate having good weather resistance, and various derivatives thereof may be used for the top coat. As the amount of the polyisocyanate used, an equivalent ratio of OH / NCO = 1 / 0.1 to 1 / 1.2 is suitable.

In carrying out the method of the present invention, first, the epoxy group-containing vinyl copolymer is usually prepared by solution polymerization, and then the drying oil fatty acid is added to the copolymer. Although at least the intended fatty acid-modified vinyl copolymer (A) is obtained, in the copolymerization reaction which should be called the first stage reaction, the polymer conversion ratio of the epoxy group-containing vinyl copolymer is Normally, after 95% or more has been secured, the drying oil fatty acid can be added to proceed with the addition reaction, which should be called the second step reaction, without waiting for the completion of the copolymerization reaction. Therefore, it is advantageous.

Also, the reaction temperature is not particularly limited, and during the copolymerization reaction, the temperature suitable for the polymerization of each component compound as described above, that is, the generally adopted 50 to 1 is used.
The temperature may be within the range of 40 ° C., on the other hand, at the time of the addition reaction, the temperature suitable for addition of each reaction component as described above, that is, the temperature within the range of 110 to 180 ° C.,
In particular, during the addition reaction, the temperature can be raised to promote this reaction, which is also advantageous.

Further, in order to accelerate the addition reaction, an epoxy group ring-opening catalyst may be used, and in this case, any known and commonly used catalyst can be used. Of these, particularly representative one is triethylamine, These include tertiary amines such as diethylenetriamine or imidazole, BF ₃ complex or acids such as phosphoric acid or sulfuric acid. Also,
As a polymerization initiator used in carrying out the polymerization, any known one can be used, and of these, particularly typical ones are azobisisobutyronitrile, benzoyl peroxide, t -Butyl perbenzoate, t-butyl per octate, di-t-
Butyl peroxide and the like.

As the solvent, known and conventional solvents can be used. Among them, particularly representative ones are aromatic solvents such as toluene or xylene, ester solvents such as ethyl acetate, butyl acetate or cellosolve acetate, and methanol or butanol. Such as alcohol-based, or ketone-based such as methyl ethyl ketone or methyl isobutyl ketone, and further hexane, heptane,
Aliphatic or cycloaliphatic solvents such as cyclohexane, methylcyclohexane, petroleum naphtha or mineral spirits can also be used, especially aliphatic or cycloaliphatic solvents in order to obtain paints that are difficult to attack old coatings. Is indispensable.

The kind, combination, and amount of the solvent used are appropriately determined in consideration of the amount of the drying oil fatty acid used and the amount of the vinyl moiety in the epoxy group-containing vinyl copolymer. be able to. The drying oil fatty acid-modified vinyl copolymer thus obtained has a form in which it is in the form of a drying oil fatty acid-modified vinyl copolymer grafted with an alkyd resin. It has excellent luster, and because of such a characteristic structure, it has an advantage that it can be air-cured by incorporating a dryer.

Further, in the present invention, during the preparation of the epoxy group-containing vinyl copolymer, that is, during the radical polymerization, the alkyd resin is not only radically polymerized but also the carboxyl group in the alkyd resin within the above-mentioned specific amount range. Also undergoes an addition reaction with the epoxy group in the epoxy group-containing vinyl monomer, and as a result, the resulting modified copolymer (A) has a wide molecular weight distribution and thus has excellent pigment dispersibility. Also, there is an advantage that a product having a feature of being excellent in a feeling of fleshness and adhesion to the base material can be obtained.

The so-called drying oil fatty acid-modified vinyl copolymer obtained by the method of the present invention meets and meets various demands in the art as described above. That is, the resin composition for an automobile repair paint thus prepared may be said to be a third type of automobile repair paint,
Crosslinking reaction due to oxidative polymerization based on a drying oil fatty acid residue contained in the modified copolymer (A), or a hydroxyl group slightly present in the modified copolymer (A), and a polyisocyanate blended therewith Crosslinking reaction with (E), and further, three types of crosslinking reactions, both of which are crosslinking reactions, can be adopted as desired for one type of modified vinyl copolymer (A), and It can be said that the composition is unique in that a coating having excellent performance can be obtained through the reaction.

Since the above-mentioned modified vinyl copolymer (A) obtained according to the method of the present invention has the drying oil fatty acid introduced therein, it has a higher dissolving power than the solvent for the acrylic polyol used in the urethane system. Since it is likely to be dissolved in a weak solvent (weak solvent), there is an advantage that a large amount of a weak solvent can be used, and therefore, a repair paint which does not easily attack the old coating film can be obtained.

Furthermore, the modified copolymer (A) has a hydroxyl group by the unique method of subjecting the epoxy group-containing vinyl copolymer to the addition reaction of the drying oil fatty acid, and in addition, in the present invention, If necessary, in addition to the epoxy group-containing vinyl monomer, a hydroxyl group-containing vinyl monomer can also be used in combination, and thus, it is possible to further contain a hydroxyl group, and as a result, polyisocyanate ( By blending E), there is an advantage that a urethane crosslinking curing method can be adopted, and further, an oxidative polymerization crosslinking curing by a dryer (D) and a curing method by two crosslinking reactions of the urethane crosslinking curing can be adopted. .

[0040]

EXAMPLES Next, the present invention will be described in detail with reference to examples, application examples and comparative application examples. In the following, all parts and% are based on weight unless otherwise specified.

Example 1 In a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer and a nitrogen gas inlet, 800 parts of xylene and "Beckozol P-470-70" (Dainippon Ink and Chemicals, Inc.) were used. Part of long oil alkyd resin manufactured by
Butyl peroxide (hereinafter abbreviated as DTBPO)
Of 2 parts of styrene (St), 300 parts of methyl methacrylate (MMA), 55 parts of acrylonitrile (AN), and glycidyl methacrylate (GMA). ) Of 125
Parts, 70 parts of ethyl acrylate (EA), 10 parts of azobisisobutyronitrile (AIBN), 7 parts of t-butyl peroctate (TBPO) and 4 parts of t-butyl perbenzoate (TBPB). The mixture was added dropwise over 5 hours, and after the completion of the addition, the temperature was kept at the same temperature for 5 hours, and when the nonvolatile content (NV) reached 53.9%, 50 parts of linseed oil fatty acid and 150 parts of soybean oil fatty acid were added. And 0.2 part of 2-methylimidazole (2MIZ) are added to carry out the addition reaction of the glycidyl group and the carboxyl group at the same temperature, the NV is 60.3% and the viscosity (Gardner; Similarly, a solution of a fatty acid-modified vinyl copolymer having Z ₆ and an acid value of 2.6 was obtained, and 400 parts of xylene was added to this solution to adjust the NV to 50%.

The resin solution thus obtained had an NV of 50.
At 1%, the viscosity is YZ, the color number (Gardner; the same applies below) is 5 to 6, and the number average molecular weight (hereinafter abbreviated as Mn) by gel permeation chromatography (GPC) is 8. , 300 transparent solution. Hereinafter, this is abbreviated as modified copolymer (A-1).

Example 2 A flask similar to that used in Example 1 was charged with "Beckozole 134".
3 "(medium oil alkyd resin manufactured by the same company), 1,300 parts of turpentine and 3 parts of DTBPO were charged and heated to 120 ° C, and at the same temperature, 300 parts of St, 300 parts of MMA, GMA. 200 parts, n-butyl acrylate (BA) 100 parts, AIBN 15 parts, TBPO 1
A mixture consisting of 0 part and 2 parts of TBPB was added dropwise over 5 hours, and the polymerization was continued by maintaining the same temperature for 12 hours to obtain NV of 42.0%. At this stage, white wax not dissolved in turpentine A vinyl copolymer in the form of a solid was obtained.

Next, 1% of the cottonseed oil fatty acid was added to this copolymer.
15 parts by adding 00 parts and 300 parts of dehydrated castor oil fatty acid
When the reaction was carried out at 0 ° C. until the acid value became about 1, NV was 0.8%, the viscosity was ZZ ₁ , the acid value was 1.1, the color number was 1-2, and A transparent resin solution having an Mn of 7,200 was obtained. Hereinafter, this is abbreviated as a modified copolymer (A-2).

Example 3 A flask similar to that used in Example 1 was charged with 1,200 xylene.
Part, 29 parts of "Beccosol P-470-70", DT
When 4 parts of BPO were charged and the temperature was raised to 125 ° C. and reached the same temperature, 200 parts of St, 230 parts of MMA, 125 parts of GMA, 100 parts of BA, 225 parts of n-butyl methacrylate (BMA). Parts, 100 parts of 2-hydroxyethyl methacrylate (2-HEMA), 5 parts of AIBN,
A mixture consisting of 3 parts of TBPO and 5 parts of TBPB was added dropwise over 5 hours, and the polymerization was continued at the same temperature to obtain NV.
When the ratio reached 44%, 100 parts of linseed oil fatty acid, 100 parts of safflower oil fatty acid and 0.02 part of BF ₃ etherate were added and reacted to an acid value of about 1, N
V is 50.5%, viscosity is Z ₄ , color number is 2, acid value is 1.8, hydroxyl value is 35, and Mn is 14,000.
A transparent resin solution was obtained. Hereinafter, this is abbreviated as modified copolymer (A-3).

Example 4 A flask similar to that used in Example 1 was charged with 1,075 xylene.
, 125 parts of "Beckozol J-571" (long oil alkyd resin manufactured by Dojo Co., Ltd.) and 4 parts of DTBPO were charged and heated to 125 ° C.
0 parts, 200 parts of BMA, 50 parts of GMA, 2-HEM
100 parts of A, 50 parts of AN, 100 parts of BA, TBP
A mixture consisting of 18 parts of O and 4 parts of TBPB was added dropwise over 4 hours, the polymerization was continued for 12 hours, then the temperature was raised to 150 ° C., and 100 parts of dehydrated castor oil fatty acid was added to add to an acid value of around 1. When the reaction was continued, NV was 49.3%, viscosity was Z ₁ , acid value was 1.2, hydroxyl group was 30, color number was 5
A transparent resin solution having a Mn of 11,000 was obtained. Hereinafter, this is abbreviated as modified copolymer (A-4).

Example 5 A flask similar to that of Example 1 except that a water separator was used instead of the reflux condenser was added to 545 parts of isophthalic acid, 248 parts of adipic acid, and 362 parts of neopentyl glycol. , 276 parts of trimethylolpropane and 18 parts of fumaric acid were charged and reacted at 180 ° C. for 3 hours in an N ₂ stream, and then the temperature was raised to 220 ° C. over 2 hours to continue the reaction. After the temperature was lowered to a value of about 6, xylene / butyl acetate = 50 /
Oil-free containing a polymerizable unsaturated bond having a viscosity of HI, an acid value of 3.8, a hydroxyl value of 81, and a color number of 2 by diluting NV to 60% with a mixed solvent of 50 (weight ratio). -An alkyd resin solution was obtained.

Next, 34 parts of this resin solution, 1,200 parts of xylene, and 5 parts of DTBPO were charged into the same flask as in Example 1, heated to 125 ° C., and when the temperature reached the same, St300. Parts, MMA 30 parts, t-butyl methacrylate (t-BMA) 100 parts, GMA125
Part, BMA285 part, 2-HEMA 40 part, BA100
Part, AIBN 8 parts, TBPO 3 parts, and TBPB 5 parts were added dropwise over 5 hours, and the polymerization was continued at the same temperature until the NV reached 44%, and 100 parts of linseed oil fatty acid and safflower were added. When 100 parts of oil fatty acid and 0.04 part of BF ₃ etherate were added and reacted to an acid value of about 1, NV was 50.1%, viscosity was YZ,
The acid value is 1.9, the number of colors is 2, the hydroxyl value is 25, and M
A transparent resin solution with n = 12,000 was obtained. Hereinafter, this is abbreviated as modified copolymer (A-5).

Example 6 NV was 50.6 in the same manner as in Example 2 except that the same amount of t-BMA was used instead of St.
%, Viscosity Y, color number 2, acid value 1.5, and Mn
A transparent resin solution of 7,100 was obtained. Hereinafter, this is abbreviated as modified copolymer (A-6).

Example 7 Instead of 200 parts of St, 100 parts of t-BMA, 5
Example 3 except that 0 parts of N-i-propylperfluorooctanesulfonamide ethyl acrylate and 50 parts of "Biscoat 8F" [Octafluorobutyl methacrylate manufactured by Osaka Organic Chemical Co., Ltd.] were used. In the same manner as above, a transparent resin solution having an NV of 49.8%, a viscosity of Z ₃ , a color number of 2, an acid value of 1.7, a hydroxyl value of 35, and an Mn of 14,000 was obtained. Hereinafter, this is abbreviated as modified copolymer (A-7).

Example 8 A flask similar to that of Example 1 was charged with 818 parts of xylene and D.
2 parts of TBPO were charged and the temperature was raised to 125 ° C., and after reaching the same temperature, the same procedure as in Example 1 was carried out except that the amount of BA was changed to 120 parts, and NV was 54.1%. Then, 50 parts of linseed oil fatty acid and 15 parts of soybean oil fatty acid
0 part and 0.2 part of 2-MIZ were added and the addition reaction was continued until the acid value was around 2.5. Then, 400 parts of xylene was added thereto to adjust the NV to 50%.
9.8%, viscosity Y, color number 5-6, acid value 2.2,
Moreover, a transparent resin solution having Mn of 8,000 was obtained. Hereinafter, this is abbreviated as a modified copolymer (A-8).

Example 9 The use of "Beckozole 1343" was completely absent, the amount of terpen used was 1,400 parts, and the NV was 41.8%.
NV was obtained in the same manner as in Example 2 except that a white waxy vinyl copolymer was obtained.
Is 50.1%, the viscosity is YZ, the acid value is 1.0, and the number of colors is 1.
A transparent resin solution having a Mn of 7,000 and a Mn of 7,000 was obtained. Hereinafter, this is abbreviated as modified copolymer (A-9).

Example 10 Instead of 3.4 parts of an oil-free alkyd resin solution containing a polymerizable unsaturated bond, 20 parts of BMA and 14 parts of xylene were used, and the initial amount charged to the flask was 1 part. , 2
With the exception of changing from 00 parts to 1,214 parts and the amount of BMA to be dropped from 285 parts to 305 parts, NV was 49.9% and viscosity was XY ₂ , in the same manner as in Example 5. A transparent resin solution having an acid value of 1.8, a color number of 1, a hydroxyl value of 25, and an Mn of 12,000 was obtained. Hereinafter, this is abbreviated as modified copolymer (A-10).

Example 11 The same amount of t-BMA was used instead of 200 parts of St, and 20 parts of BMA and 9 parts of xylene were used instead of 29 parts of "Beccozole P-470-70", respectively. In the same manner as in Example 3, except that the vinyl monomer and the solvent were used not as an initial charge but as a drop.
NV is 50.0%, viscosity is Z ₂ , color number is 1, and acid value is 1.
A transparent resin solution having a hydroxyl value of 35 and a Mn of 14,000 was obtained. Hereinafter, the modified copolymer (1-
It is abbreviated as 11).

Application Examples 1 to 23 and Comparative Application Examples 1 and 2 Modified copolymers (A-1) to (A) obtained in Examples 1 to 8
-8) and "Taipec CR-93" [Rutile titanium oxide manufactured by Ishihara Sangyo Co., Ltd.] as shown in Tables 1 and 2, 6% cobalt naphthenate / 24% lead naphthenate = 50/50 (weight ratio), a white enamel coating material was also prepared by using a dryer, a cellulose derivative, an ultraviolet absorber and / or a polyisocyanate. However, Comparative Application Examples 1 and 2 are examples in which commercially available acrylic urethane-based automotive repair paints were used.

The cellulose derivatives are 1/4 second nitrocellulose (1/4 "NC), respectively.
"EAB-551-0.2" [Eastman, USA
Kodak Cellulose Acetate Butyrate (CAB)], and a mixture of "Tinuvin 292" / "Tinuvin 900" = 50/50 (weight ratio) as an ultraviolet absorber (both "Tinuvin" are West Germany Ciba
As a polyisocyanate, a "Bernock DN-950" (a hexamethylene diisocyanate-based polyisocyanate manufactured by Dainippon Ink and Chemicals, Inc.) and a "Coronate EH" (manufactured by Nippon Polyurethane Industry Co., Ltd.) Hexamethylene diisocyanate-based polyisocyanate] of Application Examples 2 and 2
In Example 2, 2 parts of butylbenzyl phthalate was also used as a plasticizer, and all of the cellulose derivatives were used as 40% methyl ethyl ketone solutions.

Then, the white enamel was made into a paint by adding 100 parts of the modified copolymer (A), which is the main ingredient of the paint varnish, and a predetermined amount of "Taipaque CR-93", and further adding 30 parts of xylene and 200 parts. 35% by adding glass beads and kneading in a sand mill for 90 minutes
However, a mixed solvent of xylene / i-butyl acetate = 90/10 (weight ratio) was used as the thinner for dilution. Next, the coating was carried out by a spray coating method, but using “Bondellite # 144” treated dull steel plate and glass plate as the base material, and curing conditions of 60 ° C.
Forced drying for 20 minutes was adopted, and each coating film performance test was carried out after leaving for 7 days after such forced drying.

Among the test items, the "adhesion" test was a test in which the cellophane tape was peeled off after cutting the edges, that is, the cross cut was inserted, and the "gasoline resistance" test was a regular test. The degree of softening and discoloration of the coating film after soaking in gasoline for 2 hours, and the visual judgment of the presence or absence of blisters were comprehensively evaluated. The "weather resistance" test was conducted with a sunshine weather meter. , 500 hours of exposure, and 2 years of outdoor exposure in Miyazaki City, the gloss retention rate (%) is shown. The "dryness" test is dry to the touch (unit: minutes). ) And 4 layers of gauze were placed on the surface of the coating film, and 100 g of weight was further placed thereon for 1 minute, and the gauze trace was visually determined.
The evaluation criteria of the drying property are as follows.

◎ …… No gauze traces at all ○ …… Slight gauze traces △ △ …… Gauze traces are considerable × …… Remarkably gauze traces

The "lifting property" is one which has been tested and evaluated by the following method. That is, the A type test method is "Bondelight # 144"
First, a commercially available lacquer-type primer / surfacer [Isam Paint Co., Ltd. One coat "
use. ], Forcibly dried at 60 ° C. for 40 minutes, allowed to stand for a whole day and night, then polished with # 400 waterproof paper, dried, and then degreased, and further, Application Examples 1 to 23 and Comparative Application Examples 1 and 2 In this case, the lifting appears in the portion of the primer / surfacer coating film.

Next, the B-type test method is a nitrocellulose lacquer already coated on the treated steel plate as described above.
First, a commercially available urethane-based primer / surfacer (using the same Hyprasurf 2C manufactured by Dojo Co., Ltd.) is used for lacquer type old coatings such as modified acrylic lacquer, straight acrylic lacquer or high solid lacquer. ]
Is applied, and the film is forcibly dried at 60 ° C. for 40 minutes, left standing for a whole day and night, and then polished with # 400 waterproof paper, dried, and then degreased. Further, Application Examples 1 to 23 and Comparative Application Example 1 and In this case, the lifting appears in the part of the old paint film.

The results of each application example and comparative application example are separately shown in Table 1 for application examples 1 to 20 and in Table 2 for application examples 21 to 23 and comparative application examples 1 and 2. Only Comparative Applications 1 and 2 are shown in their respective tables.

[0063]

[Table 1]

<< Footnote in Table 1 >> N ... "1/4 second Nitrorose (1/4" N
C) ”abbreviation E …………“ EAB-551-0.2 ”abbreviation B …………“ Barnock DN-950 ”abbreviation C …………“ Coronate EH ”abbreviation

Gloss: 60 degree specular reflectance (%) Erichsen value: Unit: mm Impact resistance: 1/2 inch notch, 500 g
(Load), concave type Unit: mm

[0066]

[Table 2]

[0067]

[Table 3]

<< Footnote in Table 1 >>"Gloss","pencilhardness","adhesion","Erichsenvalue","impactresistance" and "gasoline resistance" are collectively referred to as "physical properties of coating film". ". Also, "combination A type" and "combination B type" are
Each of them refers to a combination of an overcoat paint and an undercoat paint, and these two performances are collectively referred to as "lifting property". "100" ......... means "100/100".

In the pencil hardness display, "~ H", "~"
"2H" and "~ 3H" are sequentially "F ~", respectively.
"H", "H-2H" and "2H-3H".

[0070]

[Table 4]

<< Footnotes in Table 1 >> "Ratio 1" ......... Abbreviation of Comparative Application Example 1 "Ratio 2" ......... Abbreviation of Comparative Application Example 2

[0072]

[Table 5]

<< Footnote in Table 1 >>"Combination A type" and "Combination B type" refer to a combination of a top coating material and a base coating material, respectively, and the combination of both performances thereof "Lifting property". “1”, “3”, “5” and “7” in the above table are respectively
"Leaving time (hrs.)" Is represented, and each of these data indicates "dryability".

[0074]

[Table 6]

[0075]

[Table 7]

<< Footnote of Table 2 >> N ......... "1/4 second nitrocellulose (1/4" N
C) ”

Gloss: 60 degree specular reflectance (%) Erichsen value: Unit: mm Impact resistance: 1/2 inch notch, 500 g
(Load), concave type Unit: mm

[0078]

[Table 8]

<< Footnote in Table 2 >>"Glossiness","Pencilhardness","Adhesion","Erichsenvalue","Impactresistance" and "Gasoline resistance" are collectively called "physical properties of coating film". ". Also, "combination A type" and "combination B type" are
Each of them refers to a combination of an overcoat paint and an undercoat paint, and these two performances are collectively referred to as "lifting property". "100" ......... means "100/100".

In the display of pencil hardness, "... H", "...
"2H" and "~ 3H" are sequentially "F ~", respectively.
"H", "H-2H" and "2H-3H".

"Ratio 1" ......... Abbreviation of Comparative Application Example 1 "Ratio 2" .... Abbreviation of Comparative Application Example 2

[0082]

[Table 9]

<< Footnote in Table 2 >>"Combination A type" and "Combination B type" refer to a combination of a top coating and a bottom coating, respectively. "Lifting property".

"1", "3", "5" and "7" in the above table each represent "standing time (hrs.)", And each of these data indicates "dryability". Is.

Application Examples 24 to 33 and Comparative Application Examples 3 to 6 First, "Acridic 44-198" [acrylic polyol manufactured by Dainippon Ink and Chemicals, Inc.] and "Bernock DN-950" (produced by the same company). Isocyanate compound)
Are colored blue with cyanine blue so that the equivalent ratio becomes OH / NCO = 1/1, and Alpaste 1109MA ”(aluminum paste manufactured by Toyo Aluminum Co., Ltd.) is also added. A base paint was prepared with 10% PWC, and then a metallic base coat was applied by air spray onto a "Bondellite # 144" treated die steel plate, and then top coating was carried out at the compounding ratio shown in Table 3. A clear was prepared (however, xylene / i-butyl acetate = 90/10 (weight ratio) was used as the diluted thinner. ] Then, a clear coating was performed by air spraying, setting was carried out for 1 hour, and then forced drying was carried out at 60 ° C. for 20 minutes to obtain a cured coating film.

That is, each application example and comparative application example of this series are for a so-called "two coat / one bake system". Then, after the forced drying, the film was allowed to stand for 7 days, and then the performance of each coating film was evaluated.

Among the test items, the gloss, hardness, Erichsen, impact resistance, gasoline resistance and weather resistance are the same as the existing ones, but the phase peeling property and the weather resistance are the same as the existing ones. The strippability and the finished appearance are as described below.

That is, the "phase separation property" is determined by checking the inter-layer adhesion between the top coat and the base coat after cutting the edges, that is, after inserting the cross cut, and peeling with the cellophane tape. It was based on the following evaluation criteria. ◎ ………… No abnormalities × ………… Peeling off

On the other hand, the "finished appearance" is a total visual judgment of unevenness of metal on the coated surface, front surface gloss, see-through gloss and feeling of flesh, and is based on the following evaluation criteria. ◎ ……… Excellent ○ ……… Good △ ……… Normal × ……… Poor

The above results are summarized in Table 3. Comparative Application Examples 3, 4, 5 and 6 are examples in which commercially available acrylic urethane-based automotive repair paints were used.

[0091]

[Table 10]

<< Footnote of Table 3 >> E ......... abbreviation of "EAB-551-0.2" B ......... abbreviation of "Barnock DN-950" C ......... abbreviation of "Coronate EH"

Gloss: 60 degree specular reflectance (%) Erichsen value: Unit: mm Impact resistance: 1/2 inch notch, 500 g
(Load), concave type Unit: mm

[0094]

[Table 11]

[0095]

[Table 12]

[0096]

[Table 13]

Application Examples 34 to 40 and Comparative Application Examples 7 to 10 Each application example and comparative application example in this series are for investigating pigment dispersibility. First, all enamel bases are as follows. 10 of the modified copolymers (A-1) to (A-11) so that a predetermined PWC such as
0 parts of each pigment was weighed, 30 parts of xylene and 200 parts of glass beads were separately added and kneaded in a sand mill for 2 hours to prepare, and then, each of the ground meat enamel base, 4%, 6% cobalt naphthenate / 24% based on the solid content of the modified copolymer used therein
Various paints were prepared by adding a mixture of lead naphthenate = 50/50 (weight ratio).

White: “Taipaque CR-93”, PWC: 35% Black: “Royal Spectra Mark II” (carbon black manufactured by Columbia Carbon Co., USA), PW
C: 30% red ... "Fastgen Super Red BN" [quinacridone pigment manufactured by Dainippon Ink and Chemicals, Inc.], P
WC: 10% Green …… “First Gen Green S” (Cyanine Green manufactured by the same company), PWC: 10%

Next, the pigment dispersibility of each paint was examined. Among them, the evaluation criteria for the thixotropy of the paint and the presence / absence of pigment aggregation are as follows. ◎ …… No abnormalities × …… Defective dispersibility due to thixotropy or aggregation

Next, the color difference (ΔE) of the spray / flow coating of the four color mixture system is white / black / red / green = 100/5/5/5.
A four-color mixture prepared by mixing the above-mentioned enamel varnish of each color in a ratio (weight ratio) and further adding a mixture of 6% cobalt naphthenate / 24% lead naphthenate = 50/50 (weight ratio). First of all, each paint on the tin plate,
It is carried out by measuring the color difference (ΔE) of a coated plate which has been spray-coated, then dried by touch and then flow-coated. The smaller this value, the smaller the color difference.
Therefore, it can be said that the pigment dispersibility is good.

The above results are summarized in Table 4 below.
The thixotropy and pigment agglomeration when titanium oxide (“Taipaque CR-93”) was used were not observed in each application example and comparative application example, and thus are not shown in the table.

[0102]

[Table 14]

[0103]

[Table 15]

[0104]

[Table 16]

[0105]

Industrial Applicability The resin for automobile repair paint obtained by the method of the present invention, that is, the drying oil fatty acid-modified vinyl copolymer for automobile repair paint, is particularly excellent in gloss, drying property and feeling of flesh. It is extremely practical because it does not easily attack the underlying coating film or the existing coating film.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08G 59/16 NHF 8416-4J C09D 125/08 PFB 9166-4J 133/00 PGC 7921-4J 151 / 08 PGX 7142-4J // B60S 5/00 7140-3D

Claims (1)

[Claims] 1. A vinyl monomer having an epoxy group of 5 to 2
5% by weight, 1 to 60% by weight of the aromatic vinyl monomer,
The alkyd resin having an unsaturated bond capable of being copolymerized has a .0.
1 to 10% by weight, and 5 to 93.9% by weight of other vinyl monomers copolymerizable therewith are selected so that the total amount becomes 100% by weight, and then copolymerized. A method for producing a resin for automobile repair paint, which comprises subjecting a drying oil fatty acid having an iodine value of 100 to 200 to an addition reaction of 5 to 60 parts by weight with respect to 100 parts by weight of a vinyl copolymer.