JP3517893B2 - Curable resin composition and coating method using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel and useful curable resin composition and a coating method using the resin composition. More specifically, according to the present invention, a cured coating film can be formed by a curing reaction involving three reactive polar groups (hereinafter, also referred to as functional groups) of a siloxy group, an acid anhydride group and an epoxy group. The present invention relates to a novel curable resin composition and a coating method using the same.

[0002]

2. Description of the Related Art In recent years, paints which are a combination of acrylic resin and melamine resin are generally used in the automobile industry mainly in terms of stability of the paint itself in line painting and coating film performance. Has been.

However, it cannot be said that the appearance of the coating film is necessarily excellent in the melamine curing system which is the mainstream today, and the acid resistance due to this melamine resin is weak. Therefore, there is a drawback that the coating film is deteriorated due to acid rain during exposure.

Further, in recent years, from the viewpoint of environmental protection, paints with low volatile organic substances (low VOC) have been actively developed, but among them, carbon dioxide gas (CO ₂₎ generated during baking of the paints has been developed. ) Is important, and in view of resource saving, it is also necessary to develop a low temperature curable coating that can be cured at about 100 ° C.

On the other hand, in the polyisocyanate curing system, there is a problem of toxicity first, and in addition, the pot life is short, and therefore, it is unsuitable and unsuitable for line coating which is continuously used in a large amount. Is.

Of course, although many proposals have been made to solve the above-mentioned various problems, they are non-isocyanate type and non-melamine type, and have excellent coating film appearance. Not to mention, it can be used as a one-component type, and in addition, it is an epoch-making curable resin composition having acid resistance to the extent that it can be used as an automobile outer panel. The reality is that has not been found yet.

[0007]

As described above, as long as the conventional technique is followed, it is inevitable that it is a low-temperature curable non-isocyanate type one and, in particular, has good acid resistance. It was extremely difficult to obtain a highly curable resin composition, and because of that, 2 coats of a form that matched the line painting of continuous and large quantity use It has been extremely difficult to obtain a curable resin composition that is ideal for so-called layered coating, in a form that matches the two-bake system or the two-coat one-bake system.

However, the inventors of the present invention have made it necessary to solve and eliminate the above-mentioned various drawbacks and problems.
The research was earnestly started.

[0009] Therefore, the problem to be solved by the present invention is, at first, a non-isocyanate type and a non-melamine type, which is excellent in the appearance of a coating film and is excellent in storage stability. Moreover, a curable resin composition of extremely high practicality, which can provide a coating film excellent in low-temperature curability and acid resistance, and a coating method of a form using the curable resin composition are provided. To provide.

[0010]

Therefore, the present inventors have
Focusing on the problem to be solved by the invention as described above, as a result of intensive and repeated studies, resins having both a siloxy group and an epoxy group, and a combination of a compound having an acid anhydride group, In so-called non-isocyanate system,
And, by using a non-melamine specific curable resin composition,

Alternatively, in such a specific resin composition,
Furthermore, by using a specific curable resin composition including a siloxy group dissociation catalyst and / or an epoxy group ring-opening catalyst, it is possible to surprisingly improve the required performances as described above. That is, it is a resin composition that is not toxic and has excellent storage stability, and in addition, it gives a coating film that has excellent low temperature curability and acid resistance. The present invention was completed here by discovering that it was a resin composition.

That is, the present invention is basically based on a vinyl-based copolymer (A) having at least one siloxy group and at least one epoxy group in each molecule [hereinafter, referred to as Also referred to as a vinyl-based copolymer resin (A) having both a siloxy group and an epoxy group. ] And a compound (B) having at least two acid anhydride groups in one molecule [hereinafter, this is also referred to as an acid anhydride group-containing compound (B). ] And

A vinyl-based copolymer (A) having at least one siloxy group and at least one epoxy group in one molecule, and a compound (B) having at least two acid anhydride groups in one molecule. ) And a siloxy group dissociation catalyst and / or an epoxy group ring opening catalyst,

[0014]

[0015]

[0016] The present invention is intended to provide a curable resin composition comprising as an essential component, and at the same time, a coating method using such a specific curable resin composition is It is an object of the present invention to provide a laminated coating method using a two-coat two-bake system or a two-coat one-bake system.

Here, first, the above-mentioned siloxy group / epoxy group-containing vinyl copolymer resin (A), respectively.
And at least 1 selected from the group consisting of vinyl-based copolymers, polyester resins and polyether resins having at least two siloxy groups in the above-mentioned molecule.
Seed resin (C) [hereinafter, these are also collectively referred to as siloxy group-containing resins (C). ], As long as it complies with such a definition, any category can be applied, but if only representative ones among them are exemplified, the side chain is as follows: For example, those having a specific bond represented by the general formula [I].

[0018]

[Chemical 1]

[Wherein R ₁ and R ₂ in the formula may be the same or different, and are C _{1 to} C ₁₈
Represents an alkyl group, a phenyl group or an aryl group, or a hydrogen atom, a fluorine atom or a chlorine atom, and R ₃ represents an alkyl group of C _{1 to} C ₁₈ , a phenyl group or an aryl group. ]

Then, at least 2 in each molecule described above.
The vinyl-based copolymer resin having more than one siloxy group,
For example, like triethylamine or pyridine,
In the presence of so-called hydrochloric acid scavengers (hydrogen chloride scavengers), various known and conventional siloxy group-containing compounds such as trialkylchlorosilane, triphenylchlorosilane, dialkylchlorosilane, dialkyldichlorosilane or dialkylhydrosilane. (Hereinafter, also referred to as silylating agent) and a so-called siloxy group-containing monomer, which is obtained by reacting various known and commonly used hydroxyl group-containing vinyl monomers, as an essential component. This refers to the resins used.

As only specific examples of such siloxy group-containing monomers, trimethylsiloxyethyl (meth) acrylate, trimethylsiloxypropyl (meth) acrylate, trimethylsiloxybutyl (meth) acrylate and triethylsiloxy are given. And methyl (meth) acrylate, tributylsiloxypropyl (meth) acrylate or triphenylsiloxyalkyl (meth) acrylate,

On the other hand, if only typical examples of other monomers copolymerizable with such siloxy group-containing monomers are given, C _{1 to} C ₂₂ alkyls having no functional groups will be described. (Meth) acrylates; various aromatic vinyl monomers such as styrene, t-butylstyrene, α-methylstyrene or vinyltoluene;

Various functional group-containing (meth) acrylates such as glycidyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate or cyclohexyl (meth) acrylate; or various nitrogen atom-containing such as (meth) acrylonitrile Starting with vinyl monomers,

[0024] (meth) acrylic acid, maleic acid, such as fumaric acid or itaconic acid, various unsaturated carboxylic acids; such as maleic acid or fumaric acid, and various unsaturated dicarboxylic acids, C ₁ -C ₁₈ becomes 1 Mono- or diesters with polyhydric alcohols (of these, the former monoesters are also called half esters or half esters); N-alkoxymethylated acrylamides;

Various N, N-dialkylaminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate or N, N-diethylaminoethyl (meth) acrylate; acid phosphonooxyethyl mono ( Various phosphorus-containing (meth) acrylates such as (meth) acrylates;

Alternatively, fluorine-containing vinyl-based monomers such as tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene or vinylidene fluoride; or vinyl acetate, vinyl propionate or "Veova" (produced by Shell Co. of the Netherlands, Vinyl esters of branched aliphatic carboxylic acids), and various vinyl esters.

The above-mentioned polyester resin having at least 2 or more siloxy groups in one molecule is, for example, polyester resins having at least 2 or more hydroxyl groups in one molecule (hereinafter referred to as hydroxyl group-containing polyester resin). (Also referred to as a group), or by reacting various known and conventional silylating agents such as trimethylchlorosiloxane,

Alternatively, the following general formula [II]

[0029]

[Chemical 2]

[However, in the formula, R ₄ , R ₅ and R ₆
Each represent the same or different phenyl group or C ₁ -C ₁₆ alkyl group, and R ₇ and R ₈ respectively represent the same or different. May represent a hydrogen atom or a C ₁ -C ₄ alkyl group. ]

It refers to resins in a form obtained by reacting a compound represented by the above with a hydroxyl group-containing polyester resin.

The hydroxyl group-containing polyester resin as the base resin is, for example, various known (anhydrous) compounds such as isophthalic acid, succinic anhydride, adipic acid or trimellitic anhydride as an acid component.
While using polybasic acids; or various known and commonly used monobasic acids such as benzoic acid or pt-butylbenzoic acid,

Various polyols such as ethylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, 1,5-pentanediol, 1,6-hexanediol, glycerin or pentaerythritol as the alcohol component. Is used to refer to a form obtained by reacting by a conventional method.

Furthermore, at least 2 in one molecule described above.
With polyether resins having more than one siloxy group,
For example, various polyalkylene glycols such as polyethylene glycol, polypropylene glycol or polybutylene glycol can be added to various known and commonly used silylating agents such as trimethylchlorosiloxane, as in the case of the siloxy group-containing polyester resin described above. It refers to something that can be obtained by reacting a class.

The above vinyl-based copolymer resin (A) is
With siloxy group-containing monomers as listed above, for example,
So-called various epoxy group-containing polymerizable unsaturated monomers such as represented by glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, vinylcyclohexene oxide or glycidyl vinyl ether. Epoxy group-containing monomers are used as an essential component, and further, other monomers capable of copolymerizing with these siloxy group-containing monomers and epoxy group-containing monomers, especially other copolymers. It refers to a product obtained by copolymerizing polymerizable vinyl monomers.

That is, to exemplify only the typical vinyl copolymer resin (A), trimethylsiloxyethyl methacrylate or triethylsiloxyethyl methacrylate is used as the siloxy group-containing monomer. On the other hand, it is obtained by using glycidyl methacrylate or glycidyl acrylate as the epoxy group-containing monomers.

Next, the compound (B) containing an acid anhydride group described above.
As just a typical example,
Represented by maleic anhydride, itaconic anhydride, and the like, various acid anhydride group-containing polymerizable unsaturated monomers, as used in the case of the siloxy group-containing vinyl copolymer resin described above, The above-mentioned various copolymerizable monomers and copolymers can be used.

In addition to such copolymers, the compound (B) may be pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, ethylene glycol bis (anhydrotrimellitate) or glycerol tris (anhydrotrimellitate). Of course, various relatively low molecular weight compounds such as tate) can also be used.

Further, as the above-mentioned vinyl copolymer resin (D) having both acid anhydride group and epoxy group, for example,
Polymerizable unsaturated monomers containing various acid anhydride groups, such as maleic anhydride and itaconic anhydride, which are used as the above-mentioned acid anhydride group-containing compound (B), and The various epoxy group-containing monomers as described above can be obtained as an essential component.

The epoxy group-containing monomers copolymerizable with the siloxy group-containing monomers or acid anhydride group-containing polymerizable unsaturated monomers described above include glycidyl (meth) acrylate, 3,4- Various epoxy group-containing polymerizable unsaturated monomers such as epoxycyclohexyl (meth) acrylate, vinylcyclohexene oxide or glycidyl vinyl ether are particularly representative.

Then, the use ratio of the above-mentioned component of the vinyl-based copolymer resin (A) having a siloxy group / epoxy group and the above-mentioned component of the acid anhydride group-containing compound (B), or the above-mentioned siloxy group-containing The ratio of the resin (C) to the acid anhydride group / epoxy group-containing vinyl copolymer resin (D) is

Although it is desirable that the functional groups (reactive polar groups) present in the respective component compounds, that is, the siloxy group, the acid anhydride group or the epoxy group, have the same equivalent ratio, The present invention is by no means limited to this, and deviates from the object of the present invention,
Alternatively, it goes without saying that these ratios should be appropriately selected and determined as long as the effects of the present invention are not impaired.

As an example, to describe the ratio of the resin (A) component to the compound (B) component used, the hydroxyl value and epoxy value are 100 mgKOH / g or 100 g / eq. And the acid anhydride group is 150 mg KO
In the case of H / g, a range of 0.2: 1 to 1: 0.2 is generally suitable,

On the other hand, as an example, to describe the ratio of the resin (C) component to the resin (D) component used, the hydroxyl value is 100 mgKOH / g, and the acid anhydride group and the epoxy value are 100 mgKOH. In the case of / g, a range of 0.5: 1 to 1: 0.2 is generally suitable.

In conclusion, the following is a brief description of the ratio of resin (A) to compound (B) and the ratio of resin (C) to resin (D). Generally, the range of 0.1: 1 to 1: 0.5 is suitable.

As described above, in the present invention, any resin or compound may be arranged in each of the essential components (A) and (B) or in each of the essential components (C) and (D). , Such a siloxy group, an acid anhydride group and an epoxy group, due to the convenience of three functional groups (reactive polar groups), so-called complex curing, especially due to the presence of a small amount of water in the air, first, a siloxy group to a hydroxyl group. Happened,

Next, through the reaction between the hydroxyl group and the acid anhydride group, intermolecular crosslinking occurs, and at the same time, through the reaction between the carboxyl group generated by the reaction of these both groups and the epoxy group, the molecule The present invention deals with composite curing in the form of inter-crosslinking, and therefore the present invention has a basic feature in dealing with such composite curing.

The thus obtained basic form curable resin composition of the present invention is first exposed to the atmosphere (in air) to react with moisture in air to
The siloxy group is hydrolyzed to generate or generate a hydroxyl group capable of reacting with an acid anhydride group, and therefore, catalysts for promoting such hydrolysis (that is,
Siloxy group dissociation catalysts) are required.

As the catalysts, only typical ones are exemplified, and various acidic catalysts such as phosphoric acid esters or phosphorous acid esters or p-toluenesulfonic acid or salts thereof; lithium hydroxide. Or various alkaline catalysts such as potassium hydroxide; or metal salts of various carboxylic acids such as alkyl titanates, octylates or lead octylates;

Alternatively, various siloxy compounds such as various sulfide- or mercaptide-type organic compounds such as monobutyltin sulfide or dioctyltin mercaptide; or various fluorine ion-generating compounds such as tetraethylammonium fluoride are first prepared. Group dissociation catalysts.

The amount of the siloxy group dissociation catalysts used is such that each of the siloxy group-containing resins described above, that is, the siloxy group / epoxy group-containing vinyl copolymer resin (A) or the siloxy group described above is used. With respect to the contained resins (C), 0.001 to 10% by weight, preferably 0.005 to 8% by weight,
Even more preferably, the range of 0.01 to 5% by weight is suitable.

On the other hand, if only typical examples of the above-mentioned epoxy group ring-opening catalysts are given, various enamines such as acetylacetonate or 1-morpholine-1-cyclohexene; benzyltrimethylammonium Including chloride, triethanolamine borate, quaternary phosphonium salts, tin octylate, quaternary ammonium salts, boron trifluoride or amine complexes (complexes),

Further, there are various amine compounds, and various imidazoles such as 1-methylimidazole. Among them, various compounds such as tetrabutylphosphonium bromide are typical. It is desirable to use a quaternary phosphonium salt, or various imidazoles typified by the above 1-methylimidazole.

The amount of such epoxy group ring-opening catalysts used is such that each of the above epoxy group-containing resins, that is, the siloxy group / epoxy group-containing vinyl copolymer resin (A) or the above acid. 0.01-based on the vinyl-based copolymer resins (D) having both anhydrous groups and epoxy groups
Within the range of 5% by weight, preferably within the range of 0.05 to 3% by weight, and more preferably within the range of 0.1 to 1% by weight.
It is appropriate that

By the way, the curable resin composition of the present invention is
Produces (generates) hydroxyl groups that can react with intramolecular or intermolecular acid anhydride groups unless exposed to the atmosphere (in air)
It goes without saying that the curable resin composition of the present invention itself is basically a one-pack type and has very good stability.

However, in order to further secure the storage stability for a long period of time, it is sufficient to always trap the invading water for some reason. That is, by adding a so-called water-binding agent that is reactive with water, the storage stability can be secured for a longer period of time.

In addition, such water binders are used in advance when the above-mentioned respective siloxy group-containing resins are prepared, that is, the above-mentioned siloxy group / epoxy group-containing vinyl copolymer resins (A) or When the siloxy group-containing resins (C) and the like described above are prepared, they can be used in the form of being mixed in at the initial stage, and there is no problem even if they are used.

As only specific examples of the water-binding agent, various trialkyl orthoformates such as trimethyl orthoformate or tributyl orthoformate; trimethyl orthoacetate and orthoacetic acid are listed. Various trialkyl orthoacetates such as triethyl or tributyl orthoacetate;

Various trialkyl orthoborates such as trimethyl orthoborate or tributyl orthoborate; tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, tetra (2-methoxyethyl) silicate or tetra (2-chloroethyl)
Various tetra (substituted) alkyl silicates such as silicate simple substance;

Various equipotential substances of the above-mentioned tetra (substituted) alkyl silicates such as tetraphenyl silicate or tetrabenzyl silicate (hereinafter abbreviated as equipotent simple substance); or tetramethyl silicate dimer, trimer, tetramer or Including hexamers,

Each of the above-mentioned tetra (substituted) alkyl silicates such as "Ethyl silicate 40" (a mixture of tetramethyl silicate dimer, trimer, tetramer pentamer and hexamer manufactured by Colcoat Co., Ltd.) and the silicates. Various hydrolyzed ester compounds, such as condensates of the same class of substances;

Alternatively, phenyl isocyanate, p-
Various isocyanate group-containing compounds such as chlorophenyl isocyanate, benzenesulfonyl isocyanate or p-toluenesulfonyl isocyanate, or isocyanate ethyl (meth) acrylate.

The amount of the water binder used is such that each of the siloxy group-containing resins described above, that is, the siloxy group-epoxy group-containing vinyl copolymer resin (A) or the siloxy group-containing resin described above. Within the range of 0.1 to 30% by weight with respect to the resins (C), preferably,
Within the range of 0.5 to 20% by weight, more preferably,
A range of 1 to 10% by weight is suitable.

The curable resin composition of the present invention thus obtained can be used as it is as a clear paint, or can be used as a so-called enamel paint by adding and mixing pigments. .

If necessary, various paint additives such as leveling agents, ultraviolet absorbers or pigment dispersants may be added and mixed. Further, similarly, it is also possible to mix well known and commonly used additives for paints, such as cellulosic compounds, plasticizers or polyester resins.

Thus, the resin composition prepared as described above is coated on the base coat paint, and, for example,
With a 2 coat 2 bake system or a 2 coat 1 bake system in which baking is performed for about 20 minutes at a desired temperature,

Furthermore, a so-called laminated structure is used in which after coating with a two-coat one-bake system, a coating film is formed with a three-coat two-bake system in which the over-top clear paint is applied. It can be used as a top clear coat for painting.

The above-mentioned base coat coating compositions are not limited to the typical ones. Of course, various compositions used in the coating method of the present invention, as well as a hydroxyl group-containing acrylic resin, are used. And a melamine resin; a composition of a hydroxyl group-containing alkyd resin and a melamine resin; a composition of each of the above hydroxyl group-containing resins and a polyisocyanate compound; or a composition of a carboxyl group-containing resin and an epoxy group-containing resin object;

Alternatively, a hydrolyzable silyl group-containing resin or the like, or a combination of two or more kinds of these and a combination of at least one organic-, inorganic- or metal pigment may be used. However, the coating composition for the base coat in this case is not particularly limited.

The curable resin composition of the present invention is mainly intended for automobiles, but it is not limited to this, but it is also intended for home electric appliances.

As a material to be applied, for example, as a bumper for automobiles, not only metal materials and metal products but also plastics can be widely spread. From this, it can be said that the use of the curable resin composition of the present invention is truly wide-ranging.

[0072]

EXAMPLES Next, the present invention will be described more concretely by reference examples, examples, comparative examples, application examples and comparative application examples. In the following, all parts and% are based on weight unless otherwise specified.

Reference Example 1 (Preparation Example of Vinyl Copolymer Containing Trimethylsiloxy Group / Epoxy Group) 500 parts of xylene was placed in a reaction vessel equipped with a thermometer, a reflux condenser, a stirrer, a dropping funnel and a nitrogen gas inlet tube. And 300 parts of n-butyl acetate were charged, and the temperature was raised to 110 ° C. under aeration of nitrogen gas.

Then, at the same temperature, 360 parts of triethylsiloxyethyl methacrylate, 75 parts of styrene, n
-168 parts of butyl methacrylate, 143 parts of n-butyl acrylate and 2 parts of glycidyl methacrylate
A mixture of 53 parts, 200 parts of xylene, 5 parts of t-butyl peroxide (TBO) and 20 parts of t-butyl peroxybenzoate (TBB) was added dropwise over 4 hours.

After the completion of dropping, the solution was kept at the same temperature for 15 hours to obtain a solution of the target copolymer having a nonvolatile content (N.V.) of 60%. Hereinafter, this is abbreviated as resin (A-1).

Reference Example 2 (Same as above) As a monomer for copolymerization, 360 parts of triethylsiloxyethyl methacrylate, 65 parts of styrene, 53 parts of n-butyl methacrylate, 1 part of n-butyl acrylate were used.
22 parts, 127 parts of glycidyl methacrylate and 27 parts of 3,4-epoxycyclohexyl methacrylate.
In the same manner as in Reference Example 1, except that 3 parts were used. V. To obtain a solution of the target copolymer having a content of 50.0%. Hereinafter, this is abbreviated as resin (A-2).

Reference Example 3 (same as above) As a monomer for copolymerization, 269 parts of triethylsiloxyethyl methacrylate and 373 of methyl methacrylate were used.
Parts, 102 parts of n-butyl acrylate and 3,4-
In the same manner as in Reference Example 1 except that 256 parts of epoxycyclohexyl methacrylate was used,
N. V. To obtain 51.1% of the target copolymer solution.
Hereinafter, this is abbreviated as resin (A-3).

Reference Example 4 (Preparation Example of Vinyl Copolymer Containing Acid Anhydride Group) A reaction vessel similar to Reference Example 1 was charged with 500 parts of xylene and 300 parts of n-butyl acetate and charged with nitrogen gas. The temperature was raised to 110 ° C under aeration.

Then, at the same temperature, 123 parts of styrene,
538 parts of n-butyl methacrylate and 339 parts of itaconic anhydride, 20 parts of TBB and 20 parts of xylene.
A mixture of 0 parts was added dropwise over 6 hours.

After completion of dropping, the temperature was maintained at 110 ° C. for 15 hours to obtain N.C. V. To obtain a solution of the target copolymer having a content of 50.2%. Hereinafter, this is abbreviated as resin (B-1).

Reference Example 5 (Same as above) Except that 100 parts of styrene, 583 parts of n-butyl acrylate, 177 parts of itaconic anhydride and 140 parts of maleic anhydride were used as the monomers for copolymerization. In the same manner as in Reference Example 4. V. Is 51.0
To obtain a solution of the target copolymer in the amount of 100%. Hereinafter, this is abbreviated as resin (B-2).

Reference Example 6 (Preparation Example of Siloxy Group-Containing Vinyl Copolymer) A reaction vessel similar to that of Reference Example 1 was charged with 500 parts of xylene and 300 parts of n-butyl acetate, and aerated with nitrogen gas. Below, it heated up to 110 degreeC.

Then, at the same temperature, 360 parts of trimethylsiloxyethyl methacrylate, 200 parts of styrene,
172 parts of n-butyl methacrylate and 268 parts of n-butyl acrylate, 5 parts of TBO and TBB
20 parts of xylene and 200 parts of xylene,
Dropwise over 6 hours.

After completion of dropping, the mixture was kept at 110 ° C. for 15 hours to give N. V. To obtain a solution of the target copolymer having a content of 51.2%. Hereinafter, this is abbreviated as resin (C-1).

Reference Example 7 (Preparation Example of Siloxy Group-Containing Polyester Resin) A reaction vessel similar to Reference Example 1 was charged with “Beckol EZ-
3530-80 "[manufactured by Dainippon Ink and Chemicals, Inc.,
Branched aliphatic monocarboxylic acid / glycidyl-modified polyester resin; V. = 80%] of 1,000 parts, and 400 parts of xylene were further charged and uniformly dissolved, and the container was cooled at room temperature with 220 parts of xylene and 200 parts of trimethylchlorosilane. While
It was added dropwise over 2 hours.

Then, in order to remove the salt produced as a by-product to the outside of the system, it was centrifuged and filtered to remove N. V. To obtain a solution of the target resin having a content of 50.5%. Hereinafter, this is abbreviated as resin (C-2).

Reference Example 8 (Preparation Example of Siloxy Group-Containing Polyether Resin) The same reaction vessel as in Reference Example 1 was charged with 1,000 parts of polypropylene glycol having a molecular weight of 500, and the temperature was adjusted to 80 ° C.
After the temperature was raised to 330 parts, 330 parts of silazane and 100 parts of toluene were added dropwise over 2 hours, and then at the same temperature,
The reaction was continued for 5 hours to continue the reaction.

Then, under reduced pressure, ammonia was removed outside the system. Thus, N. V. To obtain a solution of the target resin having a content of 70.5%. Hereinafter, this is a resin (C-3)
Is abbreviated.

Reference Example 9 (Preparation Example of Vinyl Copolymer Containing Acid Anhydride Group / Epoxy Group) A reaction vessel similar to Reference Example 1 was charged with 500 parts of xylene and 300 parts of n-butyl acetate, The temperature was raised to 110 ° C. under aeration of nitrogen gas.

Then, at the same temperature, 100 parts of styrene,
A mixture of 308 parts of n-butyl acrylate, 339 parts of itaconic anhydride and 253 parts of glycidyl methacrylate, 5 parts of TBO and 20 parts of TBB and 200 parts of xylene was added dropwise over 6 hours. .

After completion of dropping, the mixture was kept at 110 ° C. for 15 hours to obtain N. V. To obtain a solution of the target copolymer having a content of 51.0%. Hereinafter, this is abbreviated as resin (D-1).

Reference Example 10 (Same as above) As comonomers, 100 parts of styrene, 330 parts of n-butyl acrylate, 177 parts of itaconic anhydride, 140 parts of maleic anhydride and 253 parts of glycidyl methacrylate are used. Except that it was changed to the same as in Reference Example 1. V. To obtain a solution of the target copolymer having a content of 50.5%. Hereinafter, this is abbreviated as resin (D-2).

Reference Example 11 (Preparation Example of Hydroxyl Group-Containing Vinyl Copolymer) A reaction vessel similar to that of Reference Example 1 was charged with 500 parts of xylene and 300 parts of n-butyl acetate under a nitrogen gas atmosphere. Then, the temperature was raised to 110 ° C., and at this temperature, 100 parts of styrene, 500 parts of n-butyl methacrylate,
240 parts of n-butyl acrylate, 150 parts of 2-hydroxyethyl methacrylate and 10 parts of acrylic acid.
Part, 5 parts of TBO and 20 parts of TBB, and 200 parts of xylene were added dropwise over 4 hours.

After completion of dropping, the mixture was kept at 110 ° C. for 15 hours to obtain N. V. To obtain a solution of the target copolymer having a content of 50.4%. Hereinafter, this is referred to as resin (Ref-1)
Is abbreviated.

Examples 1 to 11 Vinyl copolymer resin (A) having both siloxy groups and epoxy groups
And an acid anhydride group-containing compound (B) and thinners, or selected from the group consisting of vinyl-based copolymers, polyester resins and polyether resins having at least two siloxy groups in one molecule. , At least one resin (C), an acid anhydride group / epoxy group-containing vinyl copolymer resin (D), and thinners in a ratio as shown in Table 1 by a conventional method. , N. V. Various clear paints having a content of 46.5% were obtained.

Then, each curable resin composition thus obtained was used as a top coat to form a so-called laminated coating film in the following manner. Various performances were evaluated for each coating film.
The results are collectively shown in Table 2.

That is, as a coating method at this time, a metallic base paint is applied to a treated coating plate after a predetermined treatment, that is, after a suitable treatment such as electrodeposition intermediate coating. Wet on
A two-coat, one-bake system was adopted in which a clear coating was applied by a wet system and then baked at a predetermined temperature for a predetermined time to obtain a cured coating film.

The base coating composition was 100 parts of the resin (A-3) obtained in Reference Example 3, 240 parts of the resin (B-1) obtained in Reference Example 4, and "Aluminum paste 7160".
It is a so-called metallic base coating containing a proper amount of "NS" [aluminum paste manufactured by Toyo Aluminum Co., Ltd.], or

800 of "Acridic 47-712" [hydroxyl group-containing resin manufactured by Dainippon Ink and Chemicals, Inc.]
And “Super Beckamine L-117-60” [Butyl etherified melamine resin manufactured by Dainippon Ink and Chemicals, Inc .; V. = 60%] and an appropriate amount of "aluminum paste 7160NS", a so-called metallic base coating, both of which are P
WC (pigment weight concentration) was set to 12%.

After that, the respective coating films thus obtained were subjected to a comparative examination of various characteristics and various performances. The results are summarized in Table 2 here.

Comparative Example 1 A control hydroxyl group-containing vinyl copolymer (Ref-1) obtained in Reference Example 1 and "Super Beckamine L-1" were used.
17-60 "and thinner in a ratio as shown in Table 1 by a conventional method to obtain N.I. V. As a result, a clear coating composition for control having a content of 46.5% was obtained.

Thereafter, in the same manner as in Examples 1 to 11, a cured coating film was formed and various characteristics and various performances were compared and examined. The results are summarized in Table 2.

Comparative Example 2 The hydroxyl group-containing vinyl copolymer (Ref-1) for control obtained in Reference Example 1 and "Bernock DN-901" were used.
S "[polyisocyanate resin manufactured by Dainippon Ink and Chemicals, Inc .; V. = 100%] and thinner in a ratio as shown in Table 1 by a conventional method. V. As a result, a clear coating composition for control having a content of 46.5% was obtained.

Thereafter, in the same manner as in Examples 1 to 11, a cured coating film was formed and various characteristics and various performances were compared and examined. The results are summarized in Table 2.

Comparative Example 3 In the same manner as in Comparative Example 1, resin (Ref-1), "Super Beckamine L-117-60", and thinner were used in the proportions shown in Table 1. By blending, a clear paint for control which was completely the same as that of Comparative Example 1 was obtained.

Here, the only difference between this example and Comparative Example 1 is the curing conditions. In this case as well, a comparative study of various characteristics and various properties of the coating film was performed.
The results are summarized in Table 2.

The evaluation criteria for various characteristics and various performances at that time are as follows.

"Impact resistance" ............ Displayed by the height (cm) that can withstand a load of 500 g in a DuPont impact tester

"Xylene rubbing" ... Visually judging the state of the coating film after rubbing 10 times back and forth on the coating film film with a felt impregnated with xylene.

"Acid resistance": Dropping a 5% aqueous solution of sulfuric acid on the coating film and opening it at 60 ° C.
Visually judge the state of the coating film after leaving it in the dryer for 30 minutes

"Alkali resistance": A water drop of a 5% aqueous solution of sodium hydroxide was dropped on the coating film, and after standing at room temperature for 24 hours at a closed spot, the state of the coating film was visually inspected. Judgment

"Scratch resistance" .........................................................................................................................................................
Indicated by the gloss retention rate (%) of the coating film after rubbing 10 times under a load of g

“Weather resistance” ……………… With the accelerated weather resistance tester (QUV), the gloss retention (%) at 20 degrees of the coating film after exposure for 2,000 hours was measured. Display

“Appearance” ………………………………………………………………………………………………………………………………………………………………………………
It is an index showing the sharpness or smoothness of the coating film, and the larger this value, the better the sharpness or smoothness.

"Stability of clear composition" ... Shows a value obtained by dividing the viscosity of each formulation after keeping it at 40 ° C for 20 days by the initial viscosity. The smaller this value is,
It means good stability.

[0116]

[Table 1]

<< Footnote of Table 1 >>"DP-8R" ... [Dioctylphosphoric acid manufactured by Daihachi Chemical Industry Co., Ltd.] "1-MeImi" ... 1-Methylimidazole "TBuPBr" ... Tetrabutylphosphor Nium bromide

[0118]

[Table 2]

<< Footnote in Table 1 >>"Curingconditions" are shown in the form of "temperature (° C) / hour (minute)". The unit of "Erichsen value" is "mm".

"Storage stability" is an abbreviation for "storage stability of clear paint". "Gloss" was indicated by a 20 degree specular reflectance (%).

[0121]

[Table 3]

[0122]

[Table 4]

[0123]

[Table 5]

[0124]

[Table 6]

[0125]

[Table 7]

<< Footnote in Table 1 >>"L-117" ... "L-117-60" is an abbreviation for "DN-901S" ... "Barnock DN-901S"
Abbreviation

[0127]

[Table 8]

<< Footnote of Table 1 >>"Ac / L" ... "Acridic 47-712"
/ Abbreviation of “Super Beckamine L-117-60” “14/2” ………… Abbreviation of “140/20”

[0129]

[Table 9]

As described above in detail, the curable resin composition of the present invention contains, as an active ingredient, a siloxy group / an acid anhydride group / an acid anhydride group /
By forming a cured coating film capable of exhibiting excellent effects such as low-temperature curing property and acid resistance by complex curing through three kinds of functional groups (reactive polar groups) called epoxy groups. I know that there is

In addition, it is also known that by using a dissociation catalyst, a ring-opening catalyst and / or a water-binding agent, it has extremely good storage stability as a one-pack type. Therefore, it can be said that the curable resin composition of the present invention has extremely high practicality.

Further, the coating method of the present invention, in particular, the layer coating method is performed by using such a curable resin composition. Therefore, the coating method for the car body of automobiles, metal materials or metal products is used. It is widely used for business.

[0133]

EFFECT OF THE INVENTION The curable resin composition of the present invention is particularly effective as a composite curing through three functional groups (reactive polar groups) of siloxy group / acid anhydride group / epoxy group as an active ingredient. , A cured coating film capable of exhibiting excellent effects such as low-temperature curing property and acid resistance, and in combination with a dissociation catalyst, ring-opening catalyst and / or water-binding agent As a mold, it has extremely good storage stability.

Therefore, it can be said that the curable resin composition of the present invention is extremely practical in that it can be used and applied where it can be used as a one-pack type.

Further, the coating method of the present invention, in particular, the laminated coating method is carried out by using such a curable resin composition. Therefore, the coating method for the car body of automobiles, metal materials or metal products is used. It is widely used for business.

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 59/00-59/72 C08L ⁷ /00-101/16 C09D 163/00-163/10

Claims (4)

(57) [Claims] 1. A vinyl-based copolymer (A) having at least one siloxy group and at least one epoxy group in one molecule, and a compound having at least two acid anhydride groups in one molecule. (B) is contained as an essential component, The curable resin composition characterized by the above-mentioned. 2. A vinyl-based copolymer (A) having at least one siloxy group and at least one epoxy group in one molecule, and a compound having at least two acid anhydride groups in one molecule. A curable resin composition comprising (B) and a siloxy group dissociation catalyst and / or an epoxy group ring-opening catalyst as essential components. 3. A colored film-forming composition is applied onto a substrate to form a base coat, and then the curable resin composition according to claim 1 or 2 is applied onto the base coat. A method for laminating coating, which comprises applying a clear film-forming composition to form a top coat. 4. The coating method according to claim 3, wherein the laminated coating is a two-coat one-bake method.