JP3077221B2 - Curable resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel and useful thermosetting resin composition. More specifically, the present invention provides, as an essential component, 1,3-dioxolan-2-one-4
A carboxyl group, an acid anhydride group, a hydroxyl group, a silyloxy group, and a resin composition comprising a vinyl polymer having a specific reactive polar group (functional group) such as an yl group, an epoxy group and a hydroxyl group, and a compound having an epoxy group. A compound having at least one functional group selected from the group consisting of a group and a hydrolyzable silyl group, a curing agent that reacts with a hydroxyl group, and / or a curing catalyst that promotes a curing reaction of each of these components. Particularly, the present invention relates to a thermosetting resin composition which is extremely useful and can provide a film coating excellent in acid resistance, weather resistance, scratch resistance and the like.

Conventionally, such a thermosetting resin composition of the present invention mainly uses an acrylic polyol / melamine resin-based coating, such as a coating on various metals such as an automobile body. It is used in such fields.

[0003]

2. Description of the Related Art In recent years, there has been a movement, especially in the automotive coatings industry, to place importance on the appearance of coating films. However, for the problem of maintaining the appearance of the coating film, such as the appearance of the coating film, especially, the appearance after painting and baking, as well as the deterioration under exposure, especially the deterioration of the appearance due to acid rain. It is no longer possible to satisfy all of the required performances with a coating material in which a current aminoplast-based curing agent and an acrylic polyol are combined.

[0004] In such a movement, isocyanate
A combination system of a prepolymer and a polyol type resin,
Various coatings such as a combination system of a silanol group-containing resin and an epoxy group-containing resin, a moisture curing system with a trialkoxysilyl group, and a curing system with a combination of a hydroxyl group-containing resin and an acid anhydride group-containing resin, It is being developed and considered.

[0005] Among these various coating systems, however, the combination system of the isocyanate prepolymer and the polyol-type resin has a short working life and has serious drawbacks in workability.

Further, the baking conditions include a combination system of a silanol group-containing resin and an epoxy group-containing resin, a moisture curing system with a trialkoxysilyl group, and a curing system with a combination of a hydroxyl group-containing resin and an acid anhydride group-containing resin. , And the appearance cannot be said to be sufficiently excellent.

[0007] In addition, these paint systems cause scratches on the coating film during car washing, and significantly impair the appearance of the coating film.

[0008]

Therefore, in addition to such long-term storage stability and appearance of the coating film, it is necessary to obtain a coating film that can withstand acid rain mainly in the automobile industry. The development of a new curing type (curing system) that can be performed and is extremely useful is urgently desired.

The inventors of the present invention have sought to eliminate or solve various drawbacks and problems in the prior art as described above, and in addition, in light of the above-mentioned demands, have enthusiastically started research.

[0010] Accordingly, an object of the present invention is to provide a one-pack type coating resin composition having excellent storage stability and having excellent acid resistance, weather resistance, abrasion resistance and smoothness. An object of the present invention is to provide a thermosetting resin composition which can be applied and is extremely useful.

[0011]

As a result, the present inventors have conducted intensive studies with the aim of solving the problems to be solved by the invention as described above. The invention has been completed.

That is, the present invention comprises, as an essential component, a compound represented by the general formula

[0013]

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Wherein R ₁ , R ₂ and R _{3 in the} formula
Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, which may be the same or different. 1,3-dioxolan-2-one-4
Comprising a vinyl polymer (A) having both an yl group, an epoxy group and a hydroxyl group, and an epoxy group-containing compound (B), and further comprising such a 1,3-dioxolan-2- A resin composition comprising basic essential components of a vinyl polymer (A) having an on-4-yl group, an epoxy group and a hydroxyl group and an epoxy group-containing compound (B) has a carboxyl group and an acid anhydride. A compound (D) having at least one functional group selected from the group consisting of a hydroxyl group, a hydroxyl group, a silyloxy group and a hydrolyzable silyl group, a curing agent (E) which reacts with a hydroxyl group, and / or a curing reaction of these components. Accelerated curing catalyst (C) [hereinafter abbreviated as curing catalyst (C). In particular, it is an object of the present invention to provide a thermosetting resin composition which is extremely useful and can provide a film coating excellent in acid resistance, weather resistance, scratch resistance and the like.

In this case, only typical examples of the above-mentioned vinyl polymer (A) are exemplified, and acrylic polymer, vinyl ester polymer, α
-Olefin polymers, fluoroolefin polymers or chlorinated olefin polymers.

First, 3-dioxolan-2-one-4-
As a method for introducing an yl group, for example, one ethylenically unsaturated double bond in one molecule and at least one of the above-mentioned general formula

[0017]

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Wherein R ₁ , R ₂ and R ₃ are as described above. And a compound (a-1) having a 1,3-dioxolan-2-one-4-yl group in combination with another unsaturated monomer copolymerizable therewith. Alternatively, a known and commonly used hydroxyl group-containing vinyl polymer may be subjected to an addition reaction with a polyisocyanate compound such as hexamethylene diisocyanate, and further may be subjected to an addition reaction with a carbonate monoalcohol such as glyceryl carbonate,

It is also possible to employ a method in which a carbonate monoalcohol is added to a known and commonly used isocyanate group-containing copolymer such as an isocyanate ethyl (meth) acrylate copolymer, or a known and commonly used acid chloride group is used. The copolymer containing may be subjected to a method such as an addition reaction of carbonate monoalcohols,

In particular, one ethylenically unsaturated double bond and at least one 1,3-dioxolan-2 in one molecule
Compound (a-1) having a combined -on-4-yl group
And copolymerization with other polymerizable unsaturated monomers (a-2) are particularly recommended because of their simplicity.

One ethylenically unsaturated group and at least one 1,3-dioxolan-2-one per molecule used in preparing the vinyl polymer (A).
If only typical examples of the compound (a-1) having an on-4-yl group are given, the general formula

[0022]

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Wherein R ₁ , R ₂ and R ₃ in the formula are as described above, R represents a hydrogen atom or a methyl group, and n is an integer of 1 to 6. I do. 2,3-carbonatepropyl (meth) acrylate, 2-methyl-2,3-carbonatepropyl (meth) acrylate, 4-methyl-3,4-
Carbonate butyl (meth) acrylate, 3-methyl-3,4-carbonate butyl (meth) acrylate,
In addition to (meth) acrylates such as 5-ethyl-5,6-carbonatehexyl (meth) acrylate or 7,8-carbonateoctyl (meth) acrylate, 2,3-carbonatepropylvinylether, methyl-2,3- Compounds such as carbonate propyl malate or methyl-2,3-carbonate propyl crotonate.

Next, as a method for introducing an epoxy group,
According to a method of copolymerizing various epoxy group-containing vinyl monomers such as glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate or allyl glycidyl ether, The easiest.

Further, as a method for introducing a hydroxyl group, mono (meth) acrylates or monocrotonates of various polyhydric alcohols such as ethylene glycol, propylene glycol or trimethylolpropane; A lactone such as ε-caprolactone is added to the body in a range of 1 to 10 mol,
It is easiest to copolymerize vinyl monomers and the like in the form obtained by addition.

Also, 1,3-dioxolan-2-one-
Other polymerizable unsaturated monomers copolymerizable with unsaturated monomers having a 4-yl group (cyclocarbonate group), hydroxyl-containing unsaturated monomers, and epoxy-containing unsaturated monomers The class (a-2) is not particularly limited, but among them, particularly representative ones include alkyl (meth) having an alkyl group having 1 to 22 carbon atoms. Acrylates, 2-ethoxyethyl (meth) acrylate or cyclohexyl (meth)
Various (meth) acrylates such as acrylates; dialkyl fumarate having an alkyl group having 1 to 22 carbon atoms, dialkyl maleate having an alkyl group having 1 to 22 carbon atoms, or carbon number Dialkyl itaconates having an alkyl group of 1 to 22;

Aromatic vinyl monomers such as styrene, t-butylstyrene, α-methylstyrene or vinyltoluene; various (meth) acrylamides such as (meth) acrylamide or N-alkoxymethylated (meth) acrylamide Or various kinds of fluorine-containing vinyl monomers such as tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene or vinylidene fluoride, as well as vinyl acetate, vinyl propionate, vinyl pivalate or vinyl versatate. Various carboxylic acid vinyl esters such as;

Vinyl ethers such as ethyl vinyl ether, isobutyl vinyl ether or cyclohexyl vinyl ether; various cyano group-containing vinyl monomers such as (meth) acrylonitrile; and phosphoric acid group-containing (meth) acrylates.

Using various monomers as described above,
In order to prepare the vinyl polymer (A), any known and commonly used polymerization method such as a solution polymerization method or a non-aqueous dispersion polymerization method can be applied, but the solution radical polymerization method is the simplest. It is.

As the organic solvents used here, only typical ones are exemplified. Hydrocarbon solvents such as toluene, xylene, cyclohexane, n-hexane or octane; methyl acetate, ethyl acetate, acetic acid ester solvents such as n-butyl or amyl acetate;
Or a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone or cyclohexanone, etc., which may be used alone or in combination of two or more.

Further, if only typical radical polymerization initiators are mentioned, azo compounds represented by azobisisobutyronitrile; peroxides represented by benzoyl peroxide; It is a conventional one, such as a system.

Further, if necessary, lauryl mercaptan, octyl mercaptan, 2
-Mercaptoethanol, octyl thioglycolate,
Various known and commonly used chain transfer agents such as 3-mercaptopropionic acid or α-methylstyrene dimer can also be used.

The vinyl polymer (A) thus obtained has a number average molecular weight of 800 to 50,000.
A range within is appropriate. If it is less than 800,
In any case, it is difficult to obtain a product having the required performance. On the other hand, if it exceeds 50,000, it will inevitably adversely affect workability and the like.

Then, the concentration of the cyclocarbonate group in the vinyl polymer (A), that is, the polymer (A)
The amount of the cyclocarbonate group in 100 parts by weight of is in the range of 0.01 to 0.5 mol, preferably,
A range of 0.05 to 0.25 mol is appropriate.

When the amount is less than 0.01 mol, the effect of the compound having the specific group is exerted and it is difficult to achieve the effect. On the other hand, when the amount exceeds 0.5 mol and the amount is too large, the residual In any case, only a hard and brittle coating film can be obtained due to the resulting cyclocarbonate group.

Further, 100% of the vinyl polymer (A)
The amount of the epoxy group in the parts by weight is in the range of 0.01 to 0.5 mol, preferably in the range of 0.05 to 0.25 mol.

When the amount is less than 0.01 mol, the effect of the compound having the specific group is hardly exerted. On the other hand, when the amount exceeds 0.5 mol, the remaining epoxy compound is not used. Either case is not preferable because acid resistance and water resistance are likely to be poor depending on the group.

Further, 10% of the vinyl polymer (A)
The amount of hydroxyl group in 0 parts by weight is suitably in the range of 0.01 to 0.5 mol, preferably in the range of 0.05 to 0.25 mol.

When the amount is less than 0.01 mol, the effect of the compound having the specific group is hardly exhibited,
If it is used in excess of 5 moles, the remaining hydroxyl groups tend to result in poor water resistance and the like.

Next, if only the above-mentioned epoxy group-containing compound (B), which is also referred to as the second component of the composition of the present invention, is specifically exemplified, one molecule per molecule may be used.
(B-1) having at least one ethylenically unsaturated group and at least one epoxy group, and another polymerizable unsaturated monomer (b-2) copolymerizable therewith. Or a polyisocyanate compound such as hexamethylene diisocyanate added to various known and commonly used hydroxyl-containing vinyl polymers, and further added with a glycidyl monoalcohol such as glycidol. It may be something you can get at least,

Glycidyl monoalcohols may be added to various known and commonly used isocyanate group-containing copolymers, such as isocyanate ethyl (meth) acrylate copolymers, or may be obtained. It may be obtained by subjecting various known and commonly used acid chloride group-containing copolymers to an addition reaction of glycidyl monoalcohols,

In particular, the copolymerization of a compound having one ethylenically unsaturated group and at least one epoxy group in one molecule with another polymerizable unsaturated monomer, It is particularly recommended because it is simple.

The compound (b-1) which is used in preparing the epoxy group-containing compound (B) and has one ethylenically unsaturated group and at least one epoxy group in one molecule is particularly typical. Examples include compounds such as glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, allyl glycidyl ether or 3,4-epoxy-cyclohexylmethyl (meth) acrylate.

Further, another vinyl monomer (b) copolymerizable with the epoxy group-containing unsaturated monomer (b-1)
Particularly typical examples of -2) include those already listed as copolymerizable vinyl monomers (a-2) as they are.

Representative examples of the copolymerizable hydroxyl-containing vinyl monomers include ethylene glycol,
Lactones such as ε-caprolactone may be added to mono (meth) acrylates or monocrotonates of various polyhydric alcohols such as propylene glycol or trimethylolpropane, or to the above-mentioned various hydroxyl-containing vinyl monomers. In the range of 1 to 10 mol, there may be mentioned those subjected to an addition reaction.

The method for preparing the epoxy group-containing compound (B) is the same as that for the vinyl polymer (A) having a 1,3-dioxolan-2-one-4-yl group (cyclocarbonate group). .

The number average molecular weight of the compound (B) thus obtained is suitably in the range of 800 to 50,000. If it is less than 800,
It is difficult to obtain the required performance, while 5
If it exceeds 000, workability and the like will be adversely affected.

Other examples of the epoxy group-containing compound (B) include glycidyl ethers of alcohols, glycidyl esters of carboxylic acids, and aliphatic cyclic epoxy compounds (alicyclic epoxy). Compounds) or epoxy resins such as "Epiclon 1050 or 4050" (bisphenol A type epoxy resins manufactured by Dainippon Ink and Chemicals, Inc.).

The epoxy group-containing compound (B)
The concentration of the epoxy group in the solution, that is, the amount of the epoxy group in 100 parts by weight of the compound (B) is in the range of 0.01 to 0.5 mol, preferably
A range of 0.05 to 0.25 mol is appropriate.

When the amount is less than 0.01 mol, the effect of the compound having a specific group such as an epoxy group is exhibited and it is difficult to exhibit the effect. On the other hand, when the amount is more than 0.5 mol and used too much, Is unfavorable in any case because the remaining epoxy group tends to result in only a coating film having poor acid resistance and water resistance.

Further, the epoxy group-containing compound (B)
By introducing a hydroxyl group therein, the crosslink density of the cured coating film is increased, and as a result, the various physical properties of the coating film can be further improved.

In this case, the amount of the hydroxyl group to be introduced is suitably 0.5 mol or less, preferably 0.3 mol or less, per 100 parts by weight of the epoxy group-containing compound (B). is there.

If it is used in excess of 0.5 mol, the residual hydroxyl groups tend to cause poor water resistance and the like, which is not preferable. The mixing ratio of the vinyl polymer (A) having both the 1,3-dioxolan-2-one-4-yl group, the epoxy group and the hydroxyl group and the epoxy group-containing compound (B) is as follows. ) / The latter compound (B) has a weight ratio of 10/90 to 9 in terms of solid content.
A ratio of 0/10, preferably 30/70 to 80/20 is appropriate.

When the mixing ratio is less than 10/90 or 90
When the ratio exceeds / 10, the cyclocarbonate group or the epoxy group tends to remain in the cured coating film, and the coating film performance is adversely affected.

Next, if only typical examples of the above-mentioned curing catalyst (C) are given, only tetramethylammonium fluoride, trimethylbenzylammonium hydroxide, 2-hydroxypyridine or trimethylbenzylammonium methoxide may be used. Various quaternary ammonium salts; acid catalysts such as phosphoric acid, p-toluenesulfonic acid or dimethyl sulfate; and carbonates such as calcium carbonate.

The amount of the curing catalyst (C) used is based on 100 parts by weight of the total solid content of the vinyl polymer (A) and the epoxy group-containing compound (B).
An appropriate range is 60 mmol or less, and more preferably 40 mmol or less.

If the amount used exceeds 60 mmol and becomes too large, the storage stability of the curable resin composition will be extremely reduced, and the water resistance of the coating film will also decrease.
This is not preferable because it significantly decreases.

Next, only typical compounds (D) having specific functional groups such as the above-mentioned carboxyl group, acid anhydride group, hydroxyl group, silyloxy group and / or hydrolyzable silyl group will be described. For example, a compound having one ethylenically unsaturated group and a specific functional group such as a carboxyl group, an acid anhydride group, a hydroxyl group, a silyloxy group and / or a hydrolyzable silyl group in one molecule (d
-1) may be obtained by copolymerization with another unsaturated monomer (d-2) having copolymerizability with them.

Polyester resins, alkyd resins, polyether resins or polyurethane resins, polyols or polycarboxylic acids used in the synthesis of such alkyd resins, halosilyl compounds, alkoxysilane compounds, acyloxysilanes It may be a compound, a phenoxysilane compound, an iminosilane compound or a siloxane oligomer.

The carboxyl group, acid anhydride group,
The amount of the compound (D) having a specific functional group such as a hydroxyl group, a silyloxy group, and / or a hydrolyzable silyl group may be used in the solid content of the above-mentioned vinyl polymer (A) and the epoxy group-containing compound (B). The appropriate amount is within a range of 100 parts by weight or less, preferably 60 parts by weight or less with respect to the total amount: 100 parts by weight.

If the amount of use exceeds 100 parts by weight and becomes too large, the specific unreacted carboxyl group, acid anhydride group, hydroxyl group, silyloxy group and / or hydrolyzable silyl group unreacted in the cured coating film. The compound (D) having a functional group remains, which eventually leads to a decrease in physical properties of the coating film, which is not preferable.

As the hardening agent (E) which reacts with the hydroxyl group, only typical ones are exemplified, and known hardening agents such as amino resins, isocyanate prepolymers or blocked isocyanates can be used. One.

Among them, melamine resins, benzoguanamine resins, urea resins, and the like, specifically, only typical amino resins are exemplified, and specifically, melamine, benzoguanamine, urea, and the like. As a main component, which is obtained by addition condensation of formaldehyde and aliphatic alcohols.

At that time, particularly typical aliphatic alcohols used for etherification include methanol, ethanol, n-butanol and i-butanol, which may be used alone or in combination of two or more. Good.

Next, only typical representative isocyanate prepolymers will be exemplified.
Diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or methylcyclohexane diisocyanate; or various diisocyanates thereof and various polyhydric alcohols such as ethylene glycol, propylene glycol or trimethylolpropane, Various isocyanate groups such as polyester resins having functional groups capable of reacting with isocyanate groups, acrylic polymers, polyether polyols or adducts with water, etc. Copolymers containing vinyl monomers having a functional unsaturated group; or C2-C8 alkylene- or cycloalkylene- And various isocyanurate ring-containing polyisocyanates obtained by reacting an aralkylenediisocyanate with a diol of C10 to C40 in the presence of an isocyanuration catalyst.

Further, if only typical examples of the above-mentioned blocked isocyanates are given as examples, various polyisocyanates or isocyanate prepolymers as described above may be blocked by a conventional method. Examples of such blocking agents include various phenolic compounds such as phenol or cresol; various alcoholic compounds such as methanol, ethanol or benzyl alcohol. Various active methylene group-containing compounds such as dimethyl malonate or ethyl acetoacetate; various oxime compounds such as acetoaldoxime or methyl ethyl ketone oxime; various lactam compounds such as ε-caprolactam;
Or various imidazole compounds such as 2-methylimidazole.

The amount of the curing agent (E) that reacts with the hydroxyl group is determined based on the total solid content of the vinyl polymer (A) and the epoxy group-containing compound (B):
A suitable range is 100 parts by weight or less, preferably 60 parts by weight or less based on 100 parts by weight.

If the amount is more than 100 parts by weight, the storage stability of the curable resin composition may be lowered, or the cured coating film may not have sufficient acid rain resistance. Absent.

The curable resin composition of the present invention thus obtained can be used as a clear coating as it is, or can be used as an enamel coating by incorporating a pigment.

The composition of the present invention may contain, if necessary, various known and commonly used additives such as a leveling agent, an ultraviolet absorber or a pigment dispersant, a rheology control agent or a microgel (internal part). (Including crosslinked fine particles).

Further, the composition of the present invention may be added with known and commonly used cellulosic compounds or plasticizers. The curable resin composition of the present invention, for example, as a coating method when used as a coating composition, such as brush coating, spray coating or roll coating,
A well-known and commonly used method can be employed.
It may range from so-called forced drying to bake hardening within a wide range from 0 to 180 ° C., and thus the 1,3-dioxolan-2-one-4-one which is a film-forming component of the composition of the present invention. A vinyl polymer (A) having an yl group (cyclocarbonate group), an epoxy group and a hydroxyl group, an epoxy group-containing compound (B), a carboxyl group, an acid anhydride group, a hydroxyl group, a silyloxy group and / or a hydrolyzable group Considering the combination of the compound (D) having a specific functional group of a silyl group, the hydroxyl group-reactive curing agent (E), and the curing catalyst (C), and the ratio of the amounts thereof, the optimum compounding ratio is determined. Can be designed.

The curable resin composition of the present invention can be used mainly for automobile top coats or various metal materials. In particular, remarkable effects can be expected in fields such as acrylic resin / melamine resin paint systems which have not yet reached the required levels in terms of acid resistance, weather resistance, and appearance of the coating film.

[0073]

Next, the present invention will be described more specifically with reference examples, examples, comparative examples, applied examples and comparative examples. In the following, all parts and percentages are by weight unless otherwise specified.

Reference Example 1 [Example of Preparation of Vinyl Polymer (A) Having Cyclocarbonate Group, Epoxy Group and Hydroxyl Group in Molecule] A thermometer, a cooling pipe, a stirrer, and a nitrogen gas inlet pipe were provided. In a four-necked flask, a mixture consisting of 300 parts of 2,3-carbonatepropyl methacrylate, 200 parts of styrene, 100 parts of glycidyl methacrylate, 100 parts of β-hydroxyethyl methacrylate, and 300 parts of n-butyl methacrylate, 500 xylene in advance
Parts and 300 parts of n-butanol were charged at 120 ° C.
5 hours at the same temperature with a mixture of 200 parts of xylene, 10 parts of azobisisobutyronitrile and 20 parts of t-butylperoxy-2-ethylhexanoate. After completion of the dropwise addition, the mixture was kept at the same temperature for 7 hours to continue the reaction. The nonvolatile content was 50.4%, and the Gardner viscosity at 25 ° C. (hereinafter abbreviated as viscosity) was U. A solution of the target resin at -V and having a number average molecular weight of 10,200 was obtained.

Hereinafter, this is abbreviated as resin A-1. Reference Example 2 [Preparation Example of Vinyl-Based Polymers Having Epoxy Group in the Molecule (B)] As a monomer mixture, 30% of glycidyl methacrylate was used.
The non-volatile content was 50.6 in the same manner as in Reference Example 1, except that a mixture consisting of 0 parts, 200 parts of styrene and 500 parts of n-butyl methacrylate was changed.
% And a solution of the target resin having a viscosity of DE was obtained.

Hereinafter, this is abbreviated as resin B-1. Reference Example 3 [Preparation Example of Vinyl Polymers (B) Having Both Epoxy and Hydroxyl Groups in the Molecule] As a monomer mixture, glycidyl methacrylate 30
0 parts, 100 parts of β-hydroxyethyl methacrylate,
Non-volatile content was 50.9% in the same manner as in Reference Example 1 except that a mixture consisting of 200 parts of styrene and 400 parts of n-butyl methacrylate was used.
And a solution of the target resin having a viscosity of LM was obtained.

Hereinafter, this is abbreviated as resin B-2. Reference Example 4 [Preparation example of vinyl polymer (D) having both a hydroxyl group and a carboxyl group in the molecule] As a monomer mixture, 100 parts of methacrylic acid, 200 parts of β-hydroxyethyl methacrylate, and 200 parts of styrene In the same manner as in Reference Example 1, except that a mixture of a target resin having a nonvolatile content of 51.0% and a viscosity of Z was used, except that the mixture was changed to use a mixture consisting of 500 parts of n-butyl methacrylate and n-butyl methacrylate. Obtained.

Hereinafter, this is abbreviated as Resin D-1. Examples 1 to 9 The respective resin solutions obtained in each Reference Example and the curing catalyst (C) and / or the hydroxyl-reactive curing agent (E) were
The desired curable resin composition was obtained by mixing according to the compounding composition ratio as shown in Table 1.

Comparative Example 1 "Acrydic 52-748" (acrylic resin manufactured by Dainippon Ink and Chemicals, Inc.) and "Super Beckamine L-117-60" (melamine resin manufactured by the same company) were used. A control paint in the form of 70/30 (weight ratio of solid content) was prepared.

Application Examples 1 to 9 and Comparative Application Example 1 Each of the curable resin compositions was spray-coated on a zinc phosphate-treated steel sheet and baked at 140 ° C. for 20 minutes. And various coating film performances were evaluated.

The results are shown again in the same table.

[0082]

[Table 1]

[0083]

[Table 2]

[0084]

The curable resin composition of the present invention has excellent storage stability as a one-pack type paint, and therefore has good workability as well as acid resistance,
It is also excellent in weather resistance and coating appearance.

Therefore, it can be said that the coating composition of the present invention opens up a new field as a baking coating.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) C08G 59/40 C08L 33/14 C08L 63/00-63/10 C09D 163/00-163/10 C09D 133 / 14

Claims (9)

(57) [Claims] 1. A vinyl polymer (A) having a 1,3-dioxolan-2-one-4-yl group, an epoxy group and a hydroxyl group as essential components, and a compound (B) having an epoxy group. A curable resin composition comprising: 2. A vinyl polymer (A) having a 1,3-dioxolan-2-one-4-yl group, an epoxy group and a hydroxyl group as essential components, and a compound (B) having an epoxy group. And a curing catalyst (C) for accelerating the curing reaction of each of these components . 3. A vinyl polymer (A) having a 1,3-dioxolan-2-one-4-yl group, an epoxy group and a hydroxyl group as essential components, and a compound (B) having an epoxy group. And a compound (D) having at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a silyloxy group and a hydrolyzable silyl group. Stuff. As wherein essential components, 1,3-dioxolan-2-one-4-yl group, a vinyl polymer having both an epoxy group and a hydroxyl group and (A), a compound having an epoxy group and (B) (D) having at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a silyloxy group and a hydrolyzable silyl group, and a curing catalyst for accelerating the curing reaction of these components
(C) and a curable resin composition. 5. A vinyl polymer (A) having a 1,3-dioxolan-2-one-4-yl group, an epoxy group and a hydroxyl group as essential components, and a compound (B) having an epoxy group. And a curing agent (E) that reacts with a hydroxyl group. As 6. essential component, 1,3-dioxolan-2-one-4-yl group, a vinyl polymer having both an epoxy group and a hydroxyl group and (A), a compound having an epoxy group and (B) A curing agent (E) that reacts with a hydroxyl group ,
A curable resin composition comprising a curing catalyst (C) for promoting a curing reaction of each of these components . 7. A vinyl polymer (A) having a 1,3-dioxolan-2-one-4-yl group, an epoxy group and a hydroxyl group as essential components, and a compound (B) having an epoxy group. A compound (D) having at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a silyloxy group and a hydrolyzable silyl group, and a curing agent (E) that reacts with a hydroxyl group. A curable resin composition, comprising: As 8. essential component, 1,3-dioxolan-2-one-4-yl group, a vinyl polymer having both an epoxy group and a hydroxyl group and (A), a compound having an epoxy group and (B) A compound (D) having at least one functional group selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group, a silyloxy group and a hydrolyzable silyl group, a curing agent (E) reacting with a hydroxyl group , each
A curable resin composition comprising a curing catalyst (C) for promoting a curing reaction of a component . 9. The compound (B) having an epoxy group also has a hydroxyl group.
The curable resin composition according to any one of the above.