JPH11343449A - Coating resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating resin composition with good storage stability and excellent curability at low temperatures by including an acrylic resin having hydroxyl group on the side chain, a specific organoalkoxysilane compound, and an aluminum chelate compound. SOLUTION: This coating resin composition is obtained by incorporating (A) 100 pts.wt. of an acrylic resin having hydroxyl group on the side chain with (B) 0.05-100 pts.wt. of an organoalkoxysilane compound having glycidyl and hydrolyzable alkoxysilane groups in one molecule (e.g. γ-glycidoxypropyl trimethoxysilane) and (C) 0.01-10 pts.wt. of an aluminum chelate compound (e.g. aluminum ethyl acetoacetate diisopropylate); wherein it is preferable that the component A has carboxyl group on the side chain or terminal as the functional group other than hydroxyl group, being a graft copolymer copolymerized with a poly(meth) acrylic alkyl ester macromonomer at 0.5-10 wt.% based on the total comonomer components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a low temperature (80 ° C. or less)
And a coating obtained by using the coating resin.

[0002]

2. Description of the Related Art Conventionally, a one-pack type coating resin excellent in curability at a low temperature (80 ° C. or lower) has been desired, and although the following techniques have been proposed, storage stability and curing have been proposed. No one has a good balance of properties and performance required for many paints.

That is, in the case of a conventionally used curing system of an acrylic polyol having a hydroxyl group in a molecular side chain and a melamine resin or a blocked isocyanate, or an epoxy resin using a latent catalyst (curing agent), 120 ° C.
Curing at the curing temperature lower than this is not enough to obtain a sufficient cross-linking density, and the film performance cannot be expected. For curing at a temperature lower than that, multi-partization is necessary, and many problems remain in workability. In addition, when the polyisocyanate is used, the curability is good, but the toxicity of the isocyanate cannot be ignored.

[0004] As a relatively recent technology, there is a technology in which an alkoxysilane group or an epoxy group is provided on an acrylic resin side chain and an aluminum chelate compound is added thereto (Japanese Patent Publication No. 55-41712, Japanese Patent Publication No. 60-50223). JP, JP-B-60-50225, JP-B-61-2
No. 3816, JP-B-61-23817, JP-A-64-75502, JP-A-4-139281, JP-A-1-259907, JP-A-1-28
No. 7177), this system has difficulty in arranging an alkoxysilane group on the side chain, and has poor storage stability.
This system is 2% for low temperature curing below 80 ° C in the general market.
It is applied as a liquid type.
Curability at low temperature of 0 ° C. or less is insufficient.

[0005] Further, because of having an alkoxysilane group, seeding (aggregation and the like) with a pigment is easily caused.
In addition, only the surface of the coating film is dried and hardened preferentially when applied (therefore, the solvent remains indefinitely inside the coating film, and the expected coating performance cannot be obtained). In some cases, there was a problem that spots were generated on the coating film surface.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a coating composition having excellent storage stability and excellent curability at low temperatures (80 ° C. or lower), especially It is intended to provide a liquid type paint fat composition and a paint composition obtained by using the paint resin, and to provide various properties (adhesion, appearance, weather resistance, chemical resistance) required as a paint resin. Properties, solvent resistance, etc.) and can sufficiently exhibit excellent functions.

[0007]

That is, the present invention relates to an organoalkoxysilane having a glycidyl group and a hydrolyzable alkoxysilane group in one molecule per 100 parts by weight of an acrylic resin (A) having a hydroxyl group in a side chain. A resin composition for a coating, comprising 0.05 to 100 parts by weight of a compound (B) and 0.01 to 10 parts by weight of an aluminum chelate compound (C).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The acrylic resin (A) having a hydroxyl group in a side chain according to the present invention can be prepared by preparing 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxymethacrylate when producing the acrylic resin. Butyl, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, polypropylene glycol monomethacrylate, polytetramethylene glycol monoacrylate, It can be produced by copolymerizing a hydroxyl group-containing unsaturated monomer such as polytetramethylene glycol monomethacrylate. These monomers may be used alone or as a mixture of two or more.

In order to obtain sufficient curability, storage stability and coating film performance, the monomer is preferably copolymerized as a component constituting the acrylic resin by 2 to 50% by weight. 2
If the amount is less than 50% by weight, sufficient curability may not be obtained. If the amount exceeds 50% by weight, the storage stability of the composition may be deteriorated and the form as a one-pack type composition may not be maintained. . However, when used as a two-pack type, it can exceed 50% by weight, and this is preferred because the curability is improved.

Although it depends on the application, the weight average molecular weight of the acrylic resin measured by GPC in terms of standard polystyrene is preferably 5,000 to 200,000. Those having a small molecular weight are suitable for use in automotive plastics as high solid and high appearance types, and those having a large molecular weight are suitable for use in high quality building material coatings. However, when the molecular weight is too small, the curability tends to deteriorate, and when the molecular weight is too large, the storage stability tends to deteriorate.

The acrylic resin is produced as a solvent solution or an aqueous dispersion by ordinary radical copolymerization. In the case of the present invention, toluene, xylene, butyl acetate, ethyl acetate, isopropyl alcohol, n-butyl alcohol,
Using an organic solvent such as ethylene glycol monobutyl ether, α, α′-azobisisobutyronitrile, α, α
An organic azo polymerization initiator such as' -azobis valeronitrile, and an organic peroxide such as benzoyl peroxide and t-butylperoxy-2-ethylhexanoate are used as polymerization initiators, and the polymerization temperature is 40 to 150. It is preferably produced by solution polymerization of the monomer having an epoxy group and other copolymerizable monomers at a temperature of ° C.

Here, other copolymerizable monomers refer to styrene and (meth) acrylates,
For example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, i-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, lauryl methacrylate, Stearyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate,
T-butyl acrylate, i-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate,
Lauryl acrylate, lauryl acrylate, stearyl acrylate and the like. The monomers may be used alone or as a mixture of two or more. Further, if necessary, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-acryloyloxypropyl Unsaturated monomers having a hydrolyzable alkoxysilane group, such as trimethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane, 3-acryloyloxypropyltriethoxysilane, 3-acryloyloxypropylmethyldiethoxysilane, 3-mercapto Propyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldiethyl It is also possible to copolymerize a chain transfer agent (polymerization degree modifier) having a hydrolyzable alkoxysilane group such Shishiran. These monomers may be used alone or as a mixture of two or more.

The use of a chain transfer agent such as 3-mercaptopropyltrimethoxysilane makes the composition high solid (reduction of the amount of solvent discharged during coating, that is, low pollution and resource saving), and appearance of the coating film ( It is an effective means for improving gloss and leveling properties (smoothness and sharpness of a coating film). In particular, it is effective as a top coat for paints for plastics. For the above purpose, the chain transfer agent is preferably used in an amount of 0.05 to 50 parts by weight based on 100 parts by weight of the epoxy group-containing unsaturated monomer. If less than 0.05 parts by weight,
In some cases, it is difficult to achieve the desired high solidification. If the amount exceeds 50 parts by weight, it is difficult to increase the polymerization rate during the production of the acrylic resin (A), and unreacted monomers tend to remain.

The acrylic resin (A) preferably has a carboxyl group on the side chain or terminal of the polymer. Thereby, the solvent resistance of the cured coating film (solvent rubbing property (resistance of the coating film to the solvent when the coating film is rubbed with the solvent),
Gasohol properties (coating gasoline / methyl alcohol = 1
/ L (volume ratio) of the coating film when dipped in a solution), and the like. Therefore, if a paint using the composition of the present invention is used, lifting (coating is eroded by solvent and swells and shrinks) at the time of touch-up (repainting to correct the defect of the paint defect portion). It does not wake up and improves workability. Also, for the same reason, lifting does not occur during recoating (repainting of defective parts or painting on old coatings), and the coating properties such as adhesion, coating appearance, weather resistance, etc. are excellent. .

Acrylic resin (A) having a carboxyl group as a functional group other than a hydroxyl group on the side chain or terminal of the polymer
When producing an acrylic resin, it may be produced by copolymerizing a carboxyl group-containing unsaturated monomer such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid together with the hydroxyl group-containing unsaturated monomer. it can. These monomers may be used alone or as a mixture of two or more.

These monomers are preferably copolymerized so that the acid value of the acrylic resin (A) is 0.05 to 50 mgKOH. If the acid value is less than 0.05, the expected solvent resistance may not be obtained, and if it exceeds 50, the viscosity of the composition may be high and the storage stability may be low.

The acrylic resin (A) contains a polyalkyl (meth) acrylate macromonomer in an amount of 0.1% in all copolymerized components.
It is preferable that the graft copolymer is obtained by copolymerizing 5 to 10% by weight. This improves the leveling properties of the paint (smoothness, glossiness, sharpness, concealment of scratches on the substrate after drying), surface drying (skinning; applying the paint to the substrate, drying and curing) In this case, it refers to a phenomenon in which only the surface of the coating film is dried and cured preferentially and wrinkles are generated on the surface of the coating film. This phenomenon is remarkable when applied in a state of high humidity (70% or more), which is extremely effective in preventing the problem.

The polyalkyl (meth) acrylate-based macromonomer referred to in the present application is a homopolymer such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate or the like. An acryloyl group at the terminal of the polymer main chain of a copolymer, or a homopolymer or copolymer such as methyl acrylate, ethyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, or , Methacryloyl group.

The polyalkyl (meth) acrylate macromonomer preferably has a weight average molecular weight of 2,000 to 100,000 as measured by the method described above. If the molecular weight is less than 2,000, the effect of improving leveling properties and preventing surface drying may not be sufficiently obtained. If the molecular weight exceeds 100,000, the viscosity of the composition increases and the gloss of the coating film tends to decrease. It is in.

When the poly (alkyl methacrylate) macromonomer is used, it is preferably used in an amount of 0.5 to 10% by weight based on all monomers to be copolymerized. 0.5
If the amount is less than 10% by weight, the expected effect cannot be obtained.
If it exceeds, turbidity may occur in the coating film. Also, 1
When the content exceeds 0% by weight, for example, when used as a base coat, a metal swim (when a metallic paint is applied and a top coat is applied thereon), the metal (aluminum pigment) as a pigment moves, and (Phenomenon such as deterioration or irregular reflection of light such as irregular reflection of light) or bleeding (when the base coat is attacked by the solvent of the top coat and the color (pigment) of the base coat is the top coat) Bleeding) and color separation (for similar reasons, the color of the coating film differs from the designed coating color)
Easily occur.

The organoalkoxysilane compound (B) having a glycidyl group and a hydrolyzable alkoxysilane group in one molecule includes γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxy. Silane, γ-glycidoxypropyltriisopropoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyldimethoxysilane, and the like. These compounds can be used alone or It may be a mixture of two or more. Further, partial condensates of these compounds may be used.

Organoalkoxysilane compound (B)
Is 0.05 with respect to 100 parts by weight of the acrylic resin (A).
-100 parts by weight, whereby a paint having excellent properties such as curability, storage stability and weather resistance can be obtained. 0.05
If the amount is less than 100 parts by weight, the curability will be reduced.

The aluminum chelate compound (C) of the present invention includes aluminum ethyl acetoacetate diisopropylate, aluminum tris (ethyl acetoacetate), aluminum tris (acetyl acetate), aluminum bisethyl acetoacetate monoacetylacetonate and the like. These may be used alone or as a mixture of two or more. The compound is
The curable resin composition of the present application functions as a starter for curing.

It is well known that during storage, a corresponding chelating agent is added as a stabilizer so that it does not inadvertently perform its function, and the present invention is suitably carried out. That is, in order to improve storage stability, acetylacetone,
It is preferable to add methyl acetoacetate, ethyl acetoacetate and the like.

The aluminum chelate compound (C) is used in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic resin (A).
Use parts by weight. If the amount is less than 0.01 part by weight, the curability of the coating material deteriorates, the crosslinking is delayed, and the solvent resistance and weather resistance of the coating film are reduced. If it exceeds 10 parts by weight, it will not be able to be sufficiently dissolved in the acrylic resin, and conversely, the curability will be deteriorated, and there will be bumps on the coating film, and the appearance of the coating film will deteriorate.

The resin composition for coatings of the present invention may further contain an epoxy resin. The main purpose of this is
The purpose of the present invention is to obtain a coating composition particularly suitable for metals that are easily corroded, but the substrate to be coated is not necessarily limited to metals.

The epoxy resin can be arbitrarily selected and used from many commercially available ones. That is, these include a polyphenol type, a polyglycidylamine type, an alcohol type, an ester type, an alicyclic type, and others (reference: 13197, a chemical product, Kagaku Kogyo Nippo, published in 1997, P923-P931). These epoxy resins may be used alone or as a mixture of two or more. In order to obtain sufficient curability, storage stability, and coating film performance, the epoxy equivalent of the epoxy resin is 100 to
2000. If the epoxy equivalent is less than 100, the coating film becomes hard and brittle, and if it exceeds 2,000, sufficient curability and corrosion resistance cannot be obtained.

The epoxy resin is blended in an amount of 5 to 50 parts by weight based on 100 parts by weight of the resin composition for coating. If the amount is less than 5 parts by weight, sufficient corrosion resistance cannot be obtained. If the amount exceeds 50 parts by weight, the curability deteriorates, and cracks (cracking of the coating film, undercoating, and overcoating) occur in tests such as weather resistance. Peeling) easily occurs.

The composition of the present invention can be prepared by any means as long as the acrylic resin (A) having an epoxy group in the side chain, the organoalkoxysilane compound (B) and the aluminum chelate compound (C) are uniformly mixed. Even if it is manufactured, the object can be achieved.

Briefly, while stirring the acrylic resin (A), the aluminum chelate compound (C) is charged little by little and dissolved. Next, the organoalkoxysilane compound (B) is added, and stirring is continued until the mixture becomes uniform. Heating may be used if necessary during this manufacturing process, but sufficient manufacturing is possible at room temperature, and stability of the manufacturing (because the curing reaction proceeds during the manufacturing and no gel is formed), storage From the viewpoint of stability, it is preferable to manufacture at 20 to 50 ° C.

Furthermore, by adding a diluent containing a hydrophilic organic solvent to the composition and stirring and mixing until the composition becomes uniform, the curability at low temperatures can be further improved.

Another effective method is to produce the organoalkoxysilane compound (B) as described below, and then blend it with other raw materials to similarly improve the curability at low temperatures.

That is, a predetermined amount of the organoalkoxysilane compound (B) is measured in a container equipped with a stirrer, and while stirring, a diluting solution containing a hydrophilic organic solvent is added to dilute the organoalkoxysilane compound (B). This is a method of preparing a liquid in advance.

The term "hydrophilic organic solvent" as used herein refers to an organic solvent which is soluble in water at 20 ° C. in a volume ratio of 10% or more, such as alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and n-butyl alcohol; Examples include glycol ethers such as glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol butyl ether. These solvents may be used alone or as a mixture of two or more.

By blending a diluent containing a hydrophilic organic solvent, the curability and storage stability of the composition are improved, and the finished appearance (leveling property, Sharpness, gloss, etc.) are improved. The diluting solution containing a hydrophilic organic solvent is preferably used in an amount of 100 parts by weight or less based on 100 parts by weight of the organoalkoxysilane compound (B) in order to prevent only drying of the surface of the paint.

Further, 100 parts by weight or less of water based on 100 parts by weight of the hydrophilic organic solvent (the pH at 25 ° C. is preferably 6.8 in order to improve the storage stability of the composition).
By containing the following ion-exchanged water, the curability at low temperatures is further improved.

The composition of the present invention can be used as it is or as a paint, that is, if necessary, a pigment such as titanium dioxide, carbon black or aluminum paste, or a well-known paint additive (leveling). Agents, pigment dispersants, anti-settling agents, UV absorbers, light stabilizers (HAL
S), an antifoaming agent, etc.) and a solvent for dilution, and then used as a base coat (undercoat) or a topcoat (overcoat). Further, other paints such as acrylic urethane resin paint, urethane resin paint, alkyd resin paint, epoxy resin paint, fluororesin paint, silicone resin paint, acrylic silicone resin paint, etc. (Reference: 13197 Chemical Products, Chemical Daily Inc.) (1
997))). That is, to give an example, it is also possible to apply a paint prepared using the composition of the present application as a base coat and then use an acrylic urethane resin paint as a top coat.

Base materials that can be coated include plastics such as ABS, polystyrene, polycarbonate, and nylon;
Metals such as iron, aluminum, galvanized iron and tin; and
These include those subjected to chemical conversion treatment, those subjected to cationic or anionic electrodeposition coating, and building materials such as mortar, cement, asbestos cement, asbestos cement perlite, bricks, tiles, and slate.

The coating method used is a coating prepared using the composition of the present invention, such as spray coating, brush coating, roller coating, coating with a roll coater, curtain coating, anionic electrodeposition coating, and cationic electrodeposition coating. The methods commonly used in the industry can be applied.

Painted articles can be used in a wide variety of industries. That is, for example, plastic parts and metal materials of automobiles and motorcycles (from small to large), plastic parts and metal members of household appliances,
There are outer wall materials (sizing boards, curtain walls, aluminum sashes), roof tiles, and the like.

Hereinafter, the present invention will be described in detail with reference to embodiments.

Unless otherwise specified, parts are by weight and composition ratios are by weight.

[0043]

Example 1 Methyl methacrylate solution-polymerized using α, α′-azobisisobutyronitrile as a polymerization initiator and toluene / isobutanol (= 80/20) as a solvent at a polymerization temperature of 93 ° C. (MMA) / n-butyl methacrylate (BM
A) / n-butyl acrylate (BA) / methacrylic acid 2
-Hydroxyethyl (HEMA) (= 40/30/20
/ 10) acrylic copolymer (= 50% solids,
Weight average molecular weight 35,000) is charged in a stainless beaker equipped with a stirrer (1000 g), and while stirring, aluminum chelate AW (aluminum chelate compound (aluminum tris (acetylacetate)); product of Kawaken Fine Chemical Co., Ltd.) Charge 10 g and stir until homogeneously dissolved (about 10 minutes).

To this was added 200 g of a diluting solution of the organoalkoxysilane compound (= SH-6040 / isopropyl alcohol / ion-exchanged water (= 90/9/1)) which had been previously mixed to form a uniform solution, Then, the mixture was stirred and mixed to obtain a coating resin composition of Example 1.

Example 2 The acrylic copolymer composition was changed to MMA / BMA / BA / HEM.
A coating resin composition of Example 2 was obtained in the same manner as in Example 1, except that A (= 20/20/58/2) (= solid content 50%, weight average molecular weight 35,000). .

Example 3 The acrylic copolymer composition was changed to MMA / BMA / BA / HEM.
A coating resin composition of Example 3 was obtained in the same manner as in Example 1 except that A (= 10/20/20/50) (= solid content 50%, weight average molecular weight 35,000). .

Example 4 The acrylic copolymer composition was changed to MMA / BMA / BA / HEM.
A / methacrylic acid (MAA) (= 49/20/20/1
0/1) (= 50% solids, weight average molecular weight 35,000,
A coating resin composition of Example 4 was obtained in the same manner as in Example 1 except that the acid value was changed to 6.5).

Example 5 The acrylic copolymer composition was changed to MMA / BMA / BA / HEM.
A / MAA / SZ-6030 (hydrolyzable alkoxysilyl group-containing unsaturated monomer (3-methacryloyloxypropyltrimethoxysilane); product of Dow Corning Toray Silicone Co., Ltd.) (= 37.5 / 25/20
/15/0.5/2) (= solid content: 50%, weight average molecular weight: 420,000, acid value: 3.3), except that the resin composition for the coating material of Example 5 was prepared in the same manner as in Example 1. I got something.

Example 6 The acrylic copolymer composition was changed to MMA / BMA / BA / HEM.
A / SH-6062 (Hydrolysable alkoxysilyl group-containing chain transfer agent (3-mercaptopropyltrimethoxysilane); product of Dow Corning Toray Silicone Co., Ltd.) (= 38/20/20/10/10) / 2) (= 50% solids, weight average molecular weight 188,000)
In the same manner as in Example 1, a coating resin composition of Example 6 was obtained.

Example 7 MMA prepared by solution polymerization using α, α'-azobisisobutyronitrile as a polymerization initiator at a polymerization temperature of 80 ° C. and toluene / isobutanol (= 80/20) as a solvent.
BMA / BA / HEMA (= 20/20/50/10)
Of acrylic copolymer (= 50% solids, weight average molecular weight: 80,000) in a stainless beaker equipped with a stirrer, and stirring the mixture, the aluminum chelate AW (aluminum chelate compound (aluminum tris (acetyl acetate)) )); A product of Kawaken Fine Chemical Co., Ltd.) 10 g is charged and stirred until it is uniformly dissolved (about 10 minutes). To this, mix in advance,
200 g of a diluted solution of the organoalkoxysilane compound (= SH-6040 / isopropyl alcohol / ion-exchanged water (= 90/9/1)) as a homogeneous solution was added, and the mixture was stirred and mixed until it became uniform. 7 was obtained.

Example 8 Except that the addition amount of aluminum chelate AW was 0.5 g,
In the same manner as in Example 1, a resin for coating of Example 8 was obtained.

Example 9 A paint resin for Example 9 was obtained in the same manner as in Example 1 except that the amount of the aluminum chelate AW was changed to 50 g.

Example 10 A diluted solution of an organoalkoxysilane compound (= SH-6040 / isopropyl alcohol / ion-exchanged water (= 90/9 /
A coating resin composition of Example 10 was obtained in the same manner as in Example 1 except that the addition amount of 1)) was changed to 5 g.

Example 11 A dilute solution of an organoalkoxysilane compound (= SH-6040 / isopropyl alcohol / ion-exchanged water (= 90/9 /
A coating resin composition of Example 11 was obtained in the same manner as in Example 1 except that the addition amount of 1)) was changed to 500 g.

Example 12 The composition of a diluent of an organoalkoxysilane compound previously mixed to form a uniform solution was adjusted to SH-6040 /
A coating resin composition of Example 12 was obtained in the same manner as in Example 1 except that isopropyl alcohol was 90/10.

Example 13 The acrylic copolymer composition was changed to MMA / BMA / BA / HEM.
A / MAA / AA-6 (macromonomer (polymethyl methacrylate macromonomer); product of Toagosei Co., Ltd.)
(= 39/20/20 / 19.5 / 0.5 / 1) (= solid content 50%, weight average molecular weight 35,000, acid value 3.3) Thus, a coating resin composition of Example 13 was obtained.

Example 14 The acrylic copolymer composition was changed to MMA / BMA / BA / HEM.
A / MAA / AA-6 (= 30/20/24/20/1
/ 5) (= solid content 50%, weight average molecular weight 35,000, acid value 6.5), in the same manner as in Example 1 to obtain a coating resin composition of Example 14.

Example 15 In addition to the composition of Example 1, Epicoat # 828 (bisphenol A type epoxy resin; Ciba Geigy Co., Ltd.)
Was added to obtain a coating resin composition of Example 15.

Example 16 In addition to the composition of Example 4, Epicoat # 828 (epoxy resin of bisphenol A type; Ciba-Geigy Co., Ltd.)
Was added to obtain a coating resin composition of Example 16.

Comparative Example 1 The acrylic copolymer composition was changed to MMA / BMA / BA / HEM.
A / MAA / SZ-6030 (= 38/20/19/2)
0/1/2) (= 50% solids, weight average molecular weight 4.2)
In the same manner as in Example 1 except that the acid value was 6.5) and the diluent of the organoalkoxysilane compound was not used, a coating resin composition of Comparative Example 1 was obtained.

Comparative Example 2 The acrylic copolymer composition was changed to MMA / BMA / BA / HEM.
A / MAA / SH-6062 (= 37/20/20/2
0/1/2) (= 50% solids, weight average molecular weight 1.8)
In the same manner as in Example 1 except that the acid value was 6.5) and the diluent of the organoalkoxysilane compound was not blended, a coating resin composition of Comparative Example 2 was obtained.

Comparative Example 3 A diluent of an organoalkoxysilane compound (= SH-6040 / isopropyl alcohol / ion-exchanged water (= 90/9 /
A coating resin composition of Comparative Example 3 was obtained in the same manner as in Example 1 except that the addition amount of 1)) was changed to 0.2 g.

Comparative Example 4 A diluent of an organoalkoxysilane compound (= SH-6040 / isopropyl alcohol / ion-exchanged water (= 90/9 /
A coating resin composition of Comparative Example 4 was obtained in the same manner as in Example 5, except that the amount of 1)) was changed to 0.2 g.

Comparative Example 5 A diluent of an organoalkoxysilane compound (= SH-6040 / isopropyl alcohol / ion-exchanged water (= 90/9 /
A coating resin composition of Comparative Example 5 was obtained in the same manner as in Example 6, except that the amount of 1)) was changed to 0.2 g.

Using the compositions obtained in Examples and Comparative Examples, tests and evaluations as coatings were performed. Table 1 shows the results. The evaluation method is as follows.

(1) Solvent resistance ABS obtained by defatting the composition with isopropanol (IPA)
It was applied to a plate and dried by heating at 80 ° C. for 30 minutes. The coated surface was rubbed 20 times with a felt impregnated with toluene (TOL), and the degree of attack of the coating film by the solvent was determined. ○ Good solvent resistance with no abnormalities. Pass.

X A part or the whole of the coating film is dissolved in the solvent. failure.

(2) Gel Fraction The composition was applied to a polypropylene plate and dried by heating at 80 ° C. for 30 minutes. The coating film was peeled off from the polypropylene plate, and the solvent insoluble matter (gel fraction) was measured using a Soxhlet extractor using acetone / methanol (50/50 vol%) as a solvent. The higher the gel fraction (the larger the numerical value), the better the crosslinkability. Pass if 70% or more.

(3) Internal curability The composition was applied to an IPA-degreased ABS plate with a 20 mil applicator, and the dried and cured state of the coating film was examined.

○ The coating is uniformly cured to the inside of the coating film, and the surface condition is good.

Δ: The surface hardens slightly, but the appearance is good. (Passed or more) × Only the surface is dried and cured preferentially, and wrinkles are generated on the coating film surface. (failure)

(4) Corrosion Protection The composition was applied to a degreased polished steel plate so that the coating thickness became 50 μm, and a salt spray test was carried out for 500 hours in accordance with JIS K 5400.

○ Good without any abnormality (pass) △ Rust is observed at the cut part (pass) × Rust is observed on the entire coated surface (fail)

[Table 1]

[0074]

The resin composition for coating of the present invention is formed into a coating by a usual coating preparation method, then applied to various substrates and dried at room temperature, or dried by heating to obtain adhesion, A coating film excellent in many coating performances such as weather resistance, chemical resistance, and solvent resistance can be obtained.

Claims (4)

[Claims] 1. An acrylic resin having a hydroxyl group in a side chain (A)
For 100 parts by weight, 0.05 to 100 parts by weight of an organoalkoxysilane compound (B) having a glycidyl group and a hydrolyzable alkoxysilane group in one molecule, and 0.01 to 10 parts by weight of an aluminum chelate compound (C) A resin composition for a paint, wherein the resin composition is blended in parts. 2. The coating resin composition according to claim 1, wherein the acrylic resin (A) has a carboxyl group as a functional group other than a hydroxyl group at a polymer side chain or at a terminal. 3. The acrylic resin (A) is a graft copolymer obtained by copolymerizing a polyalkyl (meth) acrylate-based macromonomer in an amount of 0.5 to 10% by weight based on all copolymerized components. The resin composition for a paint according to claim 1. 4. An epoxy equivalent of 10 parts by weight based on 100 parts by weight of the resin composition for a coating material according to claim 1.
A resin composition for a paint, which comprises 5 to 50 parts by weight of an epoxy resin of 0 to 2000.