JPH0457819A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition having acid resistance and scuffing resistance by using a vinyl resin as either a hydroxy resin or a carboxylic resin as a base resin, a polyester resin as the other component, and a specified curing agent component. CONSTITUTION:A resin composition consisting of a hydroxy resin and a carboxylic resin as essential base resins and an epoxy compound and an amino resin as essential curing agent components, wherein a vinyl resin is used as either the hydroxyl resin or the carboxylic resin, and a polyester resin is used as the other component. A resin composition which excels in properties such as acid resistance and scuffing resistance without detriment to other properties such as gloss and weathering resistance can be obtained. This resin composition is suitable as a top clear coating material in lamination coating such as two- coat-one-bake or three-coat-two-bake coating and is very useful for coating especially an automobile body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel and useful resin composition. More specifically, it consists of using a vinyl resin for either a hydroxyl group-containing resin or a carboxyl group-containing resin, each of which is an essential base resin component, and using a polyester resin for the other. In particular, the two-coat one-bake system and the three-coat two-coat system consist of using an epoxy group-containing compound and an amino resin as essential hardener components for both essential base resin components
The present invention relates to an extremely useful resin composition suitable for top clear coatings for so-called laminated coatings such as bake methods.

The resin composition of the present invention is particularly useful for coating automobile bodies.

[Conventional technology]

Up until now, these top clear paints have been
Generally, acrylic resin/melamine resin (acrylic melamine) type resins have been used.

Such acrylic melamine paints are frequently used as top clear paints for automobiles because their coating films have excellent physical properties such as gloss, weather resistance, and scratch resistance.

However, acid rain has become increasingly important in recent years, and problems such as the tendency to cause stains have come into focus.

This is due to the fact that melamine resin, which is weak against acids, is used as a curing agent component.

Although studies are being carried out at a rapid pace on curing agent components to replace melamine resin, they are currently facing a new unresolved problem: only resin compositions with insufficient scratch resistance can be obtained. is the actual situation.

[Problem to be solved by the invention]

As described above, the reality is that it is extremely difficult to obtain a resin composition that can simultaneously satisfy acid resistance and scratch resistance as long as the above-mentioned conventional techniques are followed.

To this end, the present inventors sought an extremely useful composition for laminated coatings that would maintain properties such as gloss and weather resistance while also ensuring unique properties such as acid resistance and scratch resistance. So, I earnestly began research.

Therefore, the problem to be solved by the present invention is to provide a novel resin composition that has excellent properties such as acid resistance and scratch resistance while maintaining properties such as gloss and weather resistance. It is to provide.

[Means to solve the problem]

Therefore, the present inventors focused on the problems to be solved by the invention as described above, and as a result of intensive studies, we found that a resin with a specific polar functional group called a hydroxyl group and a specific polar functional group called a carboxyl group. A resin composition comprising a resin having a functional group as an essential base resin component and an epoxy group-containing compound and an amino resin as essential curing agent components is particularly suitable for use with such hydroxyl group-containing resins or carboxyl group-containing resins. A resin composition that uses vinyl resin for one of the resins and polyester resin for the other has not only excellent gloss and weather resistance, but also
The present invention was completed by discovering that it is extremely valuable as it has excellent acid resistance and scratch resistance.

That is, the present invention uses, as essential components, a base resin component in which a vinyl resin is used for either a hydroxyl group-containing resin or a carboxyl group-containing resin, and a polyester resin is used for the other, and an epoxy group-containing compound. and a curing agent component that essentially includes an amino resin.
It aims to provide a thermosetting resin composition,
In particular, the resin composition of the present invention is suitable for so-called 2-coat
It is particularly suitable for laminated coating such as a bake method or a 3-coat, 2-bake method.

In other words, in the present invention, first, a crosslinkable base coat paint containing a brightening agent and/or a coloring pigment is applied onto the object to be coated (substrate), and then a thermosetting clear coat is applied on the surface coated with the base coat. A so-called two-coat one-bake coating method in which a paint (clear paint I) is applied and crosslinked, or a thermosetting clear coat If material (clear paint ■) The gloss, weather resistance, acid resistance, and The objective is to provide an extremely useful resin composition that has excellent and well-balanced properties such as scratch resistance.

When painting the body of a car, for example, using the various laminated coating methods described above, it is almost never the case that base coat paint, clear coat paint, etc. are applied directly to the object to be painted. Usually, several steps are involved, such as film formation of the object to be coated, electrodeposition coating, and/or intermediate coating, but it goes without saying that the conventional methods up to this point can be applied as they are.

Next, as a base coat paint, a paint using a commonly used acrylic resin and an amino resin, particularly a melamine resin, as a crosslinking agent is used.

In some cases, polyester resins can also be used, and it is also possible to combine these base resin components with cellulose derivatives.

Moreover, as a crosslinking agent, of course, isocyanate resin (isocyanate prepolymer) can also be used.

Furthermore, as a base coat paint, of course, one containing a brightening agent or a coloring pigment is used, but among these, only the most representative brightening agents will be exemplified. , metal powder such as aluminum powder, or mica, or titanium oxide coated mica.

Next, to exemplify only particularly representative coloring pigments, various inorganic pigments such as titanium oxide or carbon black, or phthalocyanine blue,
These include various organic pigments such as phthalocyanine green or quinacridone red.

Furthermore, 2 coats 1 in 3 coats 2 bake painting
As the bake clear paint, a thermosetting paint such as an ordinary acrylic resin or melamine resin is generally used. Therefore, the resin composition of the present invention is used in such a three-coat, two-bake painting process. , 3 coats 2
It is effective to use it as a bake clearer, that is, a top clearer.

Here, the vinyl resin as the above-mentioned hydroxyl group-containing resin or carboxyl group-containing resin, which is one of the essential components constituting the resin composition of the present invention, that is, the hydroxyl group-containing vinyl resin or the carboxyl group-containing vinyl resin, By a conventional method, using monomers containing a hydroxyl group or monomers containing a carboxyl group as essential, and using other monomers copolymerizable with each of these monomers containing a polar functional group, It refers to a so-called vinyl copolymer resin obtained by copolymerization.

Among them, only the most representative hydroxyl group-containing monomers are listed: 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-2-hydroxyethyl fumarate or polypropylene glycol or polyethylene glycol mono
(meth)acrylates, hydroxyalkyl esters of α,β-ethylenically unsaturated carboxylic acids, such as “Plaxel FM, FA monomer” [caprolactone addition monomer manufactured by Daicel Chemical ■], or adducts of these with ε~caprolactone Examples of carboxyl group-containing monomers include (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, and monoethyl maleate. , mono-n-butyl fumarate or mono-n-butyl itaconate, as well as various α, β as mentioned above.
-Ethylenically unsaturated carboxylic acid hydroxyalkyl esters, maleic acid, succinic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, benzenetricarboxylic acid, benzenetetracarboxylic acid, "Himic acid" [Hitachi Chemical ■Products] ], adducts of various polycarboxylic acids with anhydrides, such as tetrachlorophthalic acid or dodecynylsuccinic acid, and the like.

Next, only representative examples of other monomers copolymerizable with these hydroxyl group-containing monomers or carboxyl group-containing monomers include styrene, α-methylstyrene, , p-tert-7'tylstyrene or vinyltoluene; methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, 1so
-Propyl (meth)acrylate, n-butyl (meth)
acrylate, 1so-butyl (meth)acrylate,
tert-Butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl acrylate, benzyl (meth)acrylate, dibromopropyl (meth)acrylate or alkoxyalkyl (meth)acrylate ( Meth)acrylates: Amino group-containing amides such as N-dimethylaminoethyl (meth)acrylamide, N-diethylaminoethyl (meth)acrylamide, N-dimethylaminopropyl (meth)acrylamide or N-diethylaminopropyl (meth)acrylamide Monomers; dialkylaminoalkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate or diethylaminoethyl (meth)acrylate; tert-butylaminoethyl (meth)acrylate, tert-butylaminopropyl (meth)acrylate, Basic nitrogen atom-containing monomers such as tert-butylaminobutyl (meth)acrylate, aziridinylethyl (meth)acrylate, pyrrolidinylethyl (meth)acrylate or piperidinylethyl (meth)acrylate; Dialkyl ((meth)acryloyloxyalkyl) phosphates or (meth)acryloyloxyalkyl acid phosphates; represented by the general formula (R, R, and R8 and A are as described above); Dialkyl ((meth)acryloyloxyalkyl) phosphites; (meth)acryloyloxyalkyl acid phosphites, and alkylene oxide adducts of the above (meth)acryloyloxyalkyl acid phosphates or acid phosphites. , esterified products of epoxy group-containing vinyl monomers such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate with phosphoric acid or phosphorous acid or acidic esters thereof, 3-chloro-2-acid phosphoxy Phosphorus atom-containing monomers such as propyl (meth)acrylate; 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-2-hydroxyethyl fumarate, mono-2-hydroxyethyl-monobutyl fumarate or polyethylene glycol mono(
α,β-unsaturated carboxylic acid hydroalkyl esters such as meth)acrylates, maleic acid, succinic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, benzenetricarboxylic acid, benzenetetracarboxylic acid, “himic acid” [Hitachi Chemical ■products], adducts of polycarboxylic acids such as tetrachlorophthalic acid or dodecynylsuccinic acid with anhydrides, silicon monomers such as vinylethoxysilane, α-methacryloxypropyltrimethoxysilane; glycidyl (meth)acrylate, (β-methyl)glycidyl (meth)acrylate, (
Epoxy group-containing monomers such as meta)allyl glycidyl ether; acid anhydride group-containing monomers such as vinyl esters of maleic anhydride, itaconic anhydride, and trimellitic anhydride; Diesters of saturated dicarboxylic acids and monohydric alcohols; Vinyl acetate, vinyl benzoate, "Beova" (vinyl ester manufactured by Shell), etc. Vinyl esters; [Visco-) 88
F.

8FM, 17FM, 3F or 3FMJ (fluorine-containing acrylic monomer manufactured by Osaka Organic Chemical ■), perfluorocyclohexyl (meth)acrylate, di-perfluorocyclohexyl fumarate or N-1so-propyl perfluorooctane sulfonamide Fluorine-containing polymerizable compounds such as (per)fluoroalkyl group-containing vinyl esters, vinyl ethers, (meth)acrylates, or unsaturated polycarboxylic acid esters such as ethyl (meth)acrylate; or (meth)acrylonitrile; Vinyl monomers without polar functional groups such as olefins such as vinyl chloride or vinylidene chloride.

Furthermore, if necessary, as a copolymerizable unsaturated bond-containing resin, a resin modified with oil or fatty acid that contains an unsaturated bond and is copolymerizable with the various monomers listed above. So-called alkyd resins, unsaturated bond-containing polyester resins, unsaturated bond-containing vinyl resins, etc. can also be added to the copolymerizable monomers in the form of so-called macromonomers.

The hydroxyl group-containing or carboxyl group-containing vinyl copolymer may be prepared by a conventional method, for example, by radical copolymerization using a polymerization initiator such as a peroxide or an azo compound in an organic solvent.

The hydroxyl value of the hydroxyl group-containing vinyl copolymer is 3.
Within the range of 0 to 200 KOR7g, preferably 6
A range of 0 to 150 mgKOH/g is appropriate.

30■KO1'i/g (hereinafter, this unit will be omitted.

), as a composite curing system,
It becomes difficult to obtain a coating film with good scratch resistance (scratch resistance), and on the other hand, if it exceeds 200, the viscosity of the paint tends to increase, and as a result, workability becomes poor. In addition, the appearance of the coating film may be impaired, so either case is undesirable.

The acid value of the carboxyl group-containing vinyl copolymer is suitably in the range of 30 to 150, preferably 50 to 120.

If it is less than 30, it becomes difficult to obtain a coating film with excellent acid resistance and scratch resistance. On the other hand, if it exceeds 150, the viscosity of the paint tends to increase significantly, and as a result, Either case is unfavorable because workability deteriorates.

Particularly preferred as the above-mentioned hydroxyl group-containing vinyl resin or carboxyl group-containing vinyl resin are (meth)acryloyloxy group-containing vinyl copolymer resins, that is, a class of resins commonly called acrylic resins.

On the other hand, as the acid component used in preparing the hydroxyl group-containing or carboxyl group-containing polyester resin, it is desirable to use so-called alicyclic carboxylic acids having a cyclohexane ring in consideration of the weather resistance of the coating film. To exemplify only particularly representative alicyclic carboxylic acids, Ll-cyclohexanedicarboxylic acid, hexahydrophthalic acid (anhydride), 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, or methyl. cyclohexahydrophthalic anhydride, etc., and optionally cyclohexane-based mono- or polycarboxylic acids such as 4-tert-butylcyclohexane monocarboxylic acid, hexahydrobenzoic acid or hydrogenated trimerintic acid. , and even their methyl esters can also be used.

Other acid components include (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, benzoic acid, p-tert-butylbenzoic acid or p-methylbenzoic acid, or (
Various aromatic carboxylic acids such as (anhydrous) trimellitic acid or (anhydrous) pyromellitic acid are used, as well as adipic acid, azelaic acid, sebacic acid, tetrahydro (anhydrous) phthalic acid, and tetrachloro (anhydrous) phthalic acid. Acids such as het acid (anhydride), "hymic acid (anhydride)", maleic acid (anhydride), fumaric acid or itaconic acid are also used.

Typical examples of polyhydric alcohol components used together with these acid components include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexane glycol, diethylene glycol, and dipropylene glycol. , neopentyl glycol, triethylene glycol, cyclohexane dimetatool, hydrogenated bisphenol A1 glycerin,
These include trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol or sorbitol.

As part of the acid component in preparing the hydroxyl group-containing or carboxyl group-containing polyester resin, an oil component can also be used within a range where the oil length is less than 30%, but there are some issues such as weather resistance. It is preferable to use coconut oil, hydrogenated coconut oil, Cardura EJ (branched aliphatic monocarboxylic acid manufactured by Shell in the Netherlands), octenoic acid or isononanoic acid, and if necessary, rice bran. Oil fatty acids, tall oil fatty acids, soybean oil, castor oil or dehydrated castor oil can also be used as appropriate.

The hydroxyl value of each of the hydroxyl group-containing polyester resins thus obtained is 30 to 200 mgKOH/
g, preferably within the range of 60 to 150 gKOH/g, while the acid value of the carboxyl group-containing polyester resin is preferably within the range of 30 to 150, preferably 50 to 120 mgKOR/g. It is.

The mixing ratio of each of the hydroxyl group-containing resin and carboxyl group-containing resin mentioned above is the solid content weight ratio: carboxyl group-containing resin/hydroxyl group-containing resin = 50/
100-200/100, preferably 80/100-
A range of 150/100 is appropriate.

On the other hand, the above-mentioned epoxy group-containing compound, which is one of the essential components of the resin composition of the present invention, substantially contains 2 in one molecule.
This refers to a compound having more than one epoxy group (including a glycidyl group), so of course any compound can be used as long as it follows this definition. It is desirable to use a compound having both a decomposable silyl group, a compound having both an epoxy group and a hydroxyl group in one molecule, or a compound having both an epoxy group, a hydrolyzable silyl group, and a hydroxyl group in one molecule.

Examples of the epoxy group-containing compound include compounds having at least two epoxy groups in one molecule, such as ethylene glycol cyphlicidyl ether, neopentyl glycol diglycidyl ether, and L6.
- polyglycidyl ethers of polyhydric alcohols such as hexanesiol diglycidyl ether, diglycidyl ether of bisphenol A or triglycidyl ether of glycerin; diglycidyl ester of phthalic acid;
Polyglycidyl esters of polyvalent carboxylic acids such as diglycidyl ester of isophthalic acid or diglycidyl ester of adipic acid; or diglycidyl ether type epoxy resin of bisphenol A or bisphenol F, novola 2 type epoxy resin or hydantoin ring-containing epoxy resin Examples include polyepoxy compounds such as various epoxy resins such as resins, and even p-
Also included are glycidyl ester ether of oxybenzoic acid, and various alicyclic epoxy group-containing compounds as described below.

That is, as the epoxy resin, the use of a copolymer resin of an epoxy group-containing vinyl monomer having an epoxy group in the side chain and another monomer that can be copolymerized is particularly effective for improving scratch resistance, etc. desirable in terms of physical properties of the coating film.

Typical examples of such epoxy group-containing vinyl monomers include alicyclic epoxy group-containing vinyl monomers with the general formula [% formula %], or vinyl monomers with the above general formula. A divalent hydrocarbon group having 1 to 10 carbon atoms (R5
) include so-called aliphatic epoxy group-containing vinyl monomers such as methylene, ethylene, propylene, tetramethylene, ethylethylene, pentamethylene, hexamethylene, and polymethylene.

Here, the divalent aliphatic saturated hydrocarbon group (R5) having 1 to 6 carbon atoms is a linear or branched alkylene group, such as methylene, ethylene, propylene, tetramethylene, ethylethylene, Examples include pentamethylene methylene group, he-t-t methylene group, and other particularly representative monomers that can be copolymerized with these various epoxy group-containing vinyl monomers. To give an example only, the various monomers listed above, except for the carboxyl group-containing vinyl monomers, which are used in preparing the above-mentioned hydroxyl group-containing vinyl copolymer, can be used. , applied as is.

Next, examples of compounds having both an epoxy group and a hydrolyzable silyl group in one molecule include vinyl polymers having both of these types of reactive groups, silane coupling agents having epoxy groups, etc. is a typical example.

Here, the hydrolyzable silyl group refers to a reaction group that is easily hydrolyzed, such as a halosilyl group, an alkoxysilyl group, an acyloxysilyl group, a phenoxysilyl group, an iminooxysilyl group, or an alkenyloxysilyl group represented by the general formula. shall refer to the sexual group.

Any known method can be used to prepare a vinyl copolymer having specific bireactive groups such as those mentioned above. Acryloyloxypropylmethyldimethoxysilane, r-(meth)acryloyloxypropyltriisopropenyloxysilane, r-(
Vinyl monomers having a hydrolyzable silyl group such as meth)acryloyloxypropyltriiminooxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl(tris-β-methoxyethoxy)silane, vinyltriacetoxysilane or vinyltrichlorosilane and vinyl monomers having an epoxy group such as (β-methyl)glycidyl (meth)acrylate, allyl glycidyl ether, di(β-methyl)glycidyl maleate or di(β-methyl)glycidyl fumarate. and,
Furthermore, if necessary, solution radical copolymerization may be performed using various other copolymerizable monomers such as those listed above, or ■γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, Ethoxysilane, γ-mercaptopropylmethyldimethoxysilane,
In the presence of a chain transfer agent such as γ-mercaptopropyltriisopropenyloxysilane or γ-mercaptopropyltriiminooxysilane, a monomer mixture containing the above-mentioned epoxy group-containing vinyl monomers as an essential component is prepared. A simple method includes solution radical (co)polymerization.

Representative examples of the epoxy group-containing silane coupling agents mentioned above include T-glycidoxypropyltrimethoxysilane, T-glycidoxypropyltriethoxysilane, and γ-glycidoxypropylmethyljethoxy. Silane, γ-glycidoxypropyltriisobrobenyloxysilane, γ-glycidoxypropyltriiminooxysilane, γ-isocyanatepropyltriisopropenyloxysilane or γ-isocyanatepropyltrimethoxysilane, etc. with glycidol. Addenda:
Alternatively, it may be an adduct of T-aminopropyltrimethoxysilane or the like and a jepoxy compound.

In addition, compounds having both an epoxy group and a hydroxyl group in one molecule are also effective for increasing the curability, and to exemplify only particularly desirable compounds as such compounds, the above-mentioned side chain An epoxy group-containing vinyl monomer having an epoxy group and a hydroxyl group-containing vinyl monomer are copolymerized, and if necessary, other copolymerizable monomers are also copolymerized. It is something.

Furthermore, as one of the epoxy group-containing vinyl copolymers,
Compounds having an epoxy group, a hydrolyzable silyl group, and a hydroxyl group in one molecule can also be used, for example, compounds obtained by copolymerizing monomers having each of these various polar functional groups. .

The amount of the epoxy group-containing compound used is as follows:
The four essential components of the composition of the present invention are hydroxyl group-containing resin;
10 to 40 weight percent, preferably 15 to 3 percent, based on the total solid content of the carboxyl group-containing resin, epoxy group-containing compound, and melamine resin (hereinafter referred to as the total resin amount).
A range of 0% overlap is appropriate.

Next, the melamine resin, which is one of the essential components of the thermosetting laminated coating composition of the present invention, is only particularly representative, including alkyl etherified melamine resins, etc. To exemplify only particularly representative alkyl etherified melamine resins, [Super Beckamine L-117-60J (Dainippon Ink & Chemicals ■ product)] and [Kneepan 225]
Butoxymethylmelamine resin such as ``Cymel #300 or #303 J [Mitsui Suiana Mint product] or [Sumimar M-1]
Methoxymethyl melamine resin such as 00J (Sumitomo Chemical Co., Ltd. product); or methoxy-butoxy mixed etherified methyl melamine resin such as Cymel #1130J or Sumimal M-66BJ.

The appropriate amount of the melamine resin used is 5 to 30% by weight, preferably 10 to 25% by weight based on the total amount of resin.

In order to accelerate the curing of the composition of the present invention, curing catalysts can be used, but typical examples of such curing catalysts include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, Acid catalysts such as dinonylnaphthalenedisulfonic acid or amine-blocked products thereof, half esters of tetrachlorophthalic anhydride and monohydric alcohol, organic acids such as trichloroacetic acid; tetraisopropyl titanate, dibutyltin laurate, dibutyltin acetate, dibutyl metal-containing compounds such as tin dioctate and cobalt naphthenate; or phosphorus acidic compounds such as monoalkyl phosphoric acid, dialkyl phosphoric acid, monoalkyl phosphorous acid, dialkyl phosphoric acid or triphenylphosphine.

The appropriate amount of the curing catalyst to be used is within the range of 0.01 to 10% by weight based on the total amount of resin.

The thus obtained thermosetting laminated coating composition of the present invention, which is useful as a top clear coating, does not usually contain pigments, but it contains pigments to the extent that the transparency of the coating film is maintained.
In other words, without departing from the purpose of the present invention and without impairing the effects of the present invention, the above-mentioned brighteners and/or
Alternatively, there is no problem in adding a coloring pigment.

The composition of the present invention may further contain various resins, solvents, flow regulators, color separation inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, or silane coupling agents, as necessary. It is a matter of heat theory that various known and commonly used additives such as the following can be added.

Typical examples of the various resins include cellulose resins such as nitrocellulose or cellulose acetate butyrate, vinyl chloride/vinyl acetate copolymer resins,
Examples include ketone resin, petroleum resin, polyester resin, and fluororesin.

The solvents may be hydrocarbons such as toluene, xylene, cyclohexane, n-hexane or octane; esters such as methyl acetate, ethyl acetate, butyl acetate or ethylene glycol monoethyl ether acetate; acetone, methyl ethyl ketone, methyl Ketones such as isobutylketone, methyl amyl ketone or cyclohexanone, amides such as dimethylformamide, dimethylacetamide or N-methylpyrrolidone; or methanol, ethanol, n-probanol, 1SO-propanol, n-butanol, 1s
Typical examples include alcoholic solvents such as o-butanol, 5ec-butanol, tert-butanol, or ethylene glycol monoalkyl ether, or mixtures thereof.

In order to use the thus obtained thermosetting laminated coating composition of the present invention, particularly as a top clear coating, to form a coating film with high desired practical effects, for example, surface treatment or First, if necessary, the base coat paint is diluted with a diluting solvent on the surface of the substrate to be coated, which has been coated with brimer, surf acer, etc. in advance, so that the dry film thickness is 10 to 508 m. Then, in the case of two-coat, one-bake coating, the composition of the present invention is applied in a conventional manner to a dry film thickness of 5 to 40 μm. , may be cross-linked under predetermined conditions, or in the case of 3-coat, 2-bake painting, cross-linking is carried out in the same manner as the above-mentioned 2-coat, 1-bake painting, and then the composition of the present invention is added thereon. The material may be laminated and coated in a conventional manner to a dry film thickness of 5 to 40 .mu.m, and then crosslinked under predetermined conditions.

Usually, the conditions for each of the above-mentioned crosslinking are 110
~170'C for 15-40 minutes, preferably 130
~150°C for 20-30 minutes is suitable.

Thus, the so-called top coat film (top clear film) obtained using the thermosetting laminated coating composition of the present invention has excellent gloss and leveling properties, as well as acid resistance and scratch resistance. It has excellent properties such as image clarity and image clarity, and also has good painting workability.

[Example] Next, the present invention will be specifically explained using reference examples, examples, comparative examples, applied examples, and comparative applied examples. In the following, parts and percentages are based on weight unless otherwise specified.

Reference Example 1 (Example of Preparation of Vinyl Copolymer Resin Containing Polar Functional Groups) In a Yotsuro flask equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet tube, an aromatic hydrocarbon solution of "Turupetz 100J" (manufactured by Exxon, USA) was placed. mixture of solvents)
120 parts by charging 0 parts and 200 parts of n-butanol.
The temperature was raised to ℃.

Then, 250 parts of styrene, 300 parts of n-butyl methacrylate, 120 parts of n-butyl acrylate, 320 parts of 2-hydroxyethyl methacrylate, and 10 parts of acrylic acid, and tert-butylperoxy-2- 30 parts of ethylhexanoate, 10 parts of azobisisobutyronitrile and 10 parts of di-tert-butyl peroxybenzoate and
200 parts of ``00'' and 100 parts of n-butanol were added dropwise over 5 hours.

After completion of the dropwise addition, the reaction was continued by maintaining the same temperature for 6 hours to obtain a solution of a hydroxyl group-containing vinyl copolymer resin with a nonvolatile content of 50.2% and a hydroxyl value of 140. Hereinafter, this will be abbreviated as resin (A-1).

Reference Examples 2 to 4 (same as above) A hydroxyl group-containing vinyl copolymer resin or a carboxyl group-containing vinyl copolymer resin was prepared in the same manner as in Reference Example 1, except that the raw material charging ratio was changed as shown in Table 1. A solution of was obtained. The respective property values are summarized in the same table.

Reference Examples 5 to 9 (Preparation Examples of Epoxy Group-Containing Compounds) Solutions of various target compounds were obtained in the same manner as Reference Example 1, except that the raw material charging ratios were changed as shown in Table 2. . The property values for the solutions of each compound are summarized in the same table.

Reference Example 10 (Preparation example of carboxyl group-containing polyester resin) 136 parts of trimethylolpropane and 53 parts of neopentyl glycol were placed in a four-way flask equipped with a stirrer, a thermometer, a reflux condenser with a dehydration trap, and a nitrogen gas introduction tube.
and 208 parts of 1,6-hexanediol were charged, and the temperature was raised to 150°C.

Next, 289 parts of hexahydrophthalic acid, 410 parts of adipic acid, and 0.85 parts of lithium hydroxide were added, the temperature was raised to 220°C, and a dehydration condensation reaction was further performed at this temperature to reduce the solid content. The process was continued until the acid value reached 70.

After the reaction is complete, cool and add 428 parts of xylene.
A solution of the target resin with a nonvolatile content of 70% and an acid value of solid content of 70 was obtained. Hereinafter, this will be abbreviated as resin (P-1).

Reference Examples 11 and 12 (Same as above) A solution of the target resin was obtained in the same manner as Reference Example 1O, except that the raw material charging ratio was changed as shown in Table 3 (1).

The respective property values are summarized in the same table.

The abbreviations in the table have the following meanings.

HHPA...Hexahydrophthalic acid IPA...Isophthalic acid AA...Adipic acid TMP...Trimethylolpropane NPC...Neopentyl glycol 1.6HD...1,6-hexanediol/Star-main Table 1-m A solution of the target resin was obtained in the same manner as in Reference Example 10 except for the following changes.

Reference Examples 13 and 14 (Preparation example of hydroxyl group-containing polyester resin) Table 3 (2)
Changing the raw material preparation ratio as shown in Example 15 (Example of preparation of base coat paint) According to the composition ratio shown below, the mixture prepared by the usual paint preparation method was mixed with Ford Cup N114 using a diluting solvent. 12-1
The viscosity was adjusted to 3 seconds to obtain the intended paint.

Hereinafter, this will be abbreviated as paint (BC-1).

(BC-2) It is abbreviated as

"Super Beckamine L-117-60J" Al Paste 1860YL J 33〃 23〃 Reference Example 17 (Same as above) The same procedure as Reference Example I3 was carried out except that the composition ratio was changed as shown below. A paint was obtained. Hereinafter, this will be abbreviated as paint (BC-3).

Total 177 Reference example 16
(Same as above) Same as Reference Example 13 except that the composition ratio was changed as shown below and the adjusted viscosity was changed to 13 to 14 seconds on Ford cup floor 4. Got the paint. Hereinafter, this will be described as Paint Needle 17B#. was adjusted to obtain a clear coat paint. Below, this is a paint (C
It is abbreviated as C-1).

Resin (A-1) 100 parts resin (
P-1) 70〃Resin (E-2
) 50 ``Super Beckamine L-117-60J 60 ``Various clear coat paints were obtained.

"Tinuvin 440J 1.3
(Radical scavenger manufactured by the same company) "Nacure 5225J"
4.5 (Curing catalyst manufactured by King, USA) Triphenylphosphine D Dibutyltin dioctate L Example 2~
14 and Comparative Examples 1 to 4 Application Examples 1 to 17 were carried out in the same manner as in Example 1, except that the combinations of various resins were changed as shown in Table 4.
and Comparative Application Examples 1 to 5 Using various base coat paints obtained in Reference Examples 15 to 17 and various clear coat paints obtained in Examples 1 to 10 and Comparative Examples 1 and 2, Table 5 shows In the case of two-coat one-bake painting, respectively, on the coated plate obtained by applying electrodeposited automotive braimer and intermediate coat surfer to a mild steel plate that has been subjected to phosphorization treatment according to the conditions shown in ,first,
After applying the base coat paint by air spray to a dry film thickness of 15 to 20 μm, let it set for 3 minutes, then apply the top clear coat paint wet-on-wet to a dry film thickness of 25 to 30 μm. After painting with and leaving for 20 minutes, put it in an electric hot air dryer.
Drying was performed at 140°C for 20 minutes.

On the other hand, in the case of 3-coat, 2-bake painting, after the above-mentioned 2-coat, 1-bake painting, an overcoat clear paint is applied 1 hour later to a dry film thickness of 25 to 30 μm, and left for 10 minutes. 1 in an electric hot air dryer.
Drying was performed at 40°C for 20 minutes.

The coating film performance of each of the thus obtained laminated coatings was evaluated.

The results are summarized in the same table.

The evaluation of coating film performance was roughly conducted in the following manner.

Gloss: This is the value obtained by measuring the 60 degree specular reflectance (%) using a Murakami gloss meter.

Acid resistance: Changes in the coated surface after being immersed in a 5% sulfuric acid aqueous solution for 24 hours were visually determined.

◎... No abnormality ○... Fairly good ×... Significant discoloration and scratch resistance... After cleaning the painted surface with 5% polishing powder ice solution 50 times at a load of 300 g/rrr. The gloss retention rate (%) of the painted surface is displayed.

Weather resistance: Changes in the painted surface after 24 months of actual exposure in the suburbs of Pangkok city were visually determined.

◎...No abnormalities O...Slight discoloration ×...Significant discoloration and chipping resistance...50g of No. 7 crushed stone at 4kg/cf
The coating was applied to the coated surface under the following conditions, and the degree of peeling of the coating was visually determined.

◎...When the peeled diameter is less than 1 mm ×...When the peeled diameter is in the range of 1 to 5IIIn [Effects of the Invention] The thermosetting laminated coating composition of the present invention obtained as described above is as follows: The composition of the present invention is extremely useful as a so-called composite curing system of a carboxyl group-containing resin-epoxy group-containing compound curing system and a hydroxyl group-containing resin-melamine resin curing system. By using it as an overcoat clear paint, it has excellent acid resistance and scratch resistance.In other words, it has excellent and well-balanced properties such as gloss, weather resistance, acid resistance, and scratch resistance. It is of extremely high practical value.

Agent: Patent Attorney Katsutoshi Takahashi

Claims (1)

[Scope of Claims] 1. A resin composition comprising a hydroxyl group-containing resin and a carboxyl group-containing resin as essential base resin components, and an epoxy group-containing compound and an amino resin as essential curing agent components, . A resin composition characterized in that, as the base resin component described above, a vinyl resin is used for either a hydroxyl group-containing resin or a carboxyl group-containing resin, and a polyester resin is used for the other one. 2. The above-mentioned hydroxyl group-containing resin is 30 to 200 mg KOH
The resin composition according to claim 1, which has a hydroxyl value of /g. 3. The carboxyl group-containing resin described above is 30 to 150 m
The resin composition according to claim 1, which has an acid value of gKOH/g. 4. The resin composition according to claim 1, wherein the epoxy compound has both an epoxy group and a hydrolyzable silyl group in one molecule. 5. The resin composition according to claim 1, wherein the epoxy group-containing compound has both an epoxy group and a hydroxyl group in one molecule. 6. The resin composition according to claims 1 to 5, which is used as the clear paint in laminated painting in which a base paint containing a brightening agent and/or a color pigment is coated, and then a clear paint is further laminated and crosslinked. 7. A base paint containing a brightening agent and/or a colored pigment is laminated, and a clear paint is applied on top of the base paint to cause crosslinking.
The resin composition according to any one of claims 1 to 5, which is used as each of the above-mentioned clear paints in laminated painting in which a clear paint is then further laminated and crosslinked thereon.