JPH09310043A - Curable resin composition for topcoat - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] A curable resin composition for a top coating which has curability at room temperature, is excellent in appearance, stain resistance, weather resistance and adhesion, and can form a coating film having a small contact angle. Providing things. SOLUTION: A specific silicon-containing compound and / or a partial hydrolysis-condensation product (B) thereof is added to 100 parts by weight of an acrylic copolymer (A) containing a specific reactive silyl group bonded to a carbon atom. 2 to 70 parts by weight, a curing catalyst (C) of 0.1 to 20 parts by weight, and an aromatic silane coupling agent (D) of 0.1 to 20 parts by weight of a curable resin composition for top coating composition. .

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a curable resin composition for a topcoat paint. More specifically, for example, metal,
The present invention relates to a curable resin composition for a topcoat paint which can be suitably used for coating buildings, home appliances, industrial equipment, etc. made of ceramics, glass, cement, ceramic moldings, plastics, wood, paper, fibers and the like.

[0002]

2. Description of the Related Art Conventionally, the surface of industrial products such as ceramic moldings, concrete, steel and other constructions, building materials, etc. can be coated with, for example, fluororesin paints, acrylic urethane resin paints, acrylic silicone resin paints, etc. By coating with the paint of, you can give a design effect to buildings,
Its weather resistance is also improved.

However, in recent years, with the deterioration of the environment mainly in the urban areas, it has been required to further improve the stain resistance of the paint.

Therefore, the inventors of the present invention have conducted earnest studies to obtain a composition capable of forming a coating film having excellent stain resistance in addition to the above-mentioned weather resistance, and as a result, a specific reactive silyl group has been obtained. A resin composition comprising an acrylic copolymer containing styrene, a silicon compound, a curing catalyst, and an aliphatic hydrocarbon-based adhesiveness improving component has been found (JP-A-7-48).
No. 540).

The coating film formed from the above resin composition has not only excellent weather resistance and stain resistance, but also good adhesion, and such a resin composition is used for various top coats. It can be suitably used.

However, as a result of subsequent research, for example, when an organic solvent-based paint is used as the undercoat paint,
Undercoating film formed from such an organic solvent-based paint, the adhesion between the topcoating film formed from the resin composition,
Compared with the case of an undercoating film formed from a paint other than an organic solvent-based paint, it was found that it may slightly decrease, forming a film that exhibits extremely excellent adhesion to various types of substrates. The development of a curable resin composition for a top coating, which can be performed, has been awaited.

[0007]

DISCLOSURE OF THE INVENTION The present invention is aimed at further improvement of the above resin composition and has curability at room temperature, and is similar to a coating film formed from, for example, an acrylic silicone resin-based paint. In addition to having excellent weather resistance, it also has excellent stain resistance, and has excellent adhesion to a wide variety of substrates, and it forms a coating film with improved appearance such as surface gloss. It is an object of the present invention to provide a curable resin composition for a top coat, which can be used.

[0008]

According to the present invention, there is provided a compound represented by the general formula (I):

[0009]

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(Wherein R ¹ is a hydrogen atom or a group having 1 to 1 carbon atoms)
10 alkyl groups, R ² is a hydrogen atom or a carbon number of 1 to 1
0 is a monovalent hydrocarbon group selected from an alkyl group, an aryl group and an aralkyl group, and a is 0, 1 or 2.
With respect to 100 parts by weight of the resin solid content of the acrylic copolymer (A) containing a reactive silyl group bonded to a carbon atom represented by the general formula (II):

[0011]

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(Wherein R ³ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, and R ⁴ is an alkyl group having 1 to 10 carbon atoms, an aryl group and A monovalent hydrocarbon group or an alkoxy group selected from aralkyl groups, b is 0 or 1) and a silicon-containing compound and / or a partial hydrolysis-condensation product (B) of 2 to 70 parts by weight, a curing catalyst (C) 0.
1 to 20 parts by weight, and a silane coupling agent (D) selected from an aromatic amine, a reaction product of an aromatic amine and an epoxysilane compound, and a reaction product of an aromatic carboxylic acid and an amino group-containing silane compound. The present invention relates to a curable resin composition for topcoat paint, which comprises 1 to 20 parts by weight.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the curable resin composition for top coating composition of the present invention (hereinafter, also referred to as curable resin composition) has the general formula (I):

[0014]

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(Wherein R ¹ is a hydrogen atom or a group having 1 to 1 carbon atoms)
10 alkyl groups, R ² is a hydrogen atom or a carbon number of 1 to 1
0 is a monovalent hydrocarbon group selected from an alkyl group, an aryl group and an aralkyl group, and a is 0, 1 or 2.
With respect to 100 parts (parts by weight, the same applies hereinafter) of the resin solid content of the acrylic copolymer (A) containing a reactive silyl group bonded to a carbon atom represented by the general formula (II):

[0016]

[Chemical 6]

(Wherein R ³ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, and R ⁴ is an alkyl group having 1 to 10 carbon atoms, an aryl group and A silicon-containing compound represented by a monovalent hydrocarbon group or an alkoxy group selected from aralkyl groups, b is 0 or 1, and 2 to 70 parts of a partial hydrolysis-condensation product (B) thereof, a curing catalyst ( C) 0.1
20 parts, and a silane coupling agent (D) 0.1 to 20 selected from an aromatic amine, a reaction product of an aromatic amine and an epoxysilane compound, and a reaction product of an aromatic carboxylic acid and an amino group-containing silane compound. It is obtained by mixing parts.

The acrylic copolymer (A) used in the curable resin composition for a top coat of the present invention is a base resin which is curable at room temperature in the presence of moisture, and its main chain is substantially A curable resin composition for a topcoat paint of the present invention, since it is a copolymer in which the acrylic monomer is a copolymerized main chain (hereinafter, the main chain is also substantially composed of an acrylic copolymer chain). The coating film formed from is excellent in weather resistance and chemical resistance.

The main chain of the acrylic copolymer (A) being substantially composed of the acrylic copolymer chain means that 50% by weight of the units constituting the main chain of the acrylic copolymer (A). The above means that preferably 70% by weight or more is formed from the acrylic monomer unit.

Further, since the acrylic copolymer (A) contains a reactive silyl group in a form in which a carbon atom is bonded, the water resistance, alkali resistance, acid resistance and the like of the coating film formed are improved. It will be excellent.

In the acrylic copolymer (A), the number of reactive silyl groups bonded to the carbon atom represented by the general formula (I) should be 1 or more per one molecule of the acrylic copolymer (A). However, it is preferable that the number is 2 or more, especially 3 or more, from the viewpoint that the coating film formed from the curable resin composition of the present invention is more excellent in durability such as weather resistance and solvent resistance.

The reactive silyl group represented by the above general formula (I) may be bonded to the terminal of the main chain of the acrylic copolymer (A) or may be bonded to the side chain thereof. It may be attached to the chain ends and side chains.

In the above general formula (I), R ¹ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, It is an alkyl group having 1 to 4 carbon atoms such as i-butyl group. When the number of carbon atoms in the alkyl group exceeds 10, the reactivity of the reactive silyl group is reduced. Also, when R ¹ is a group other than an alkyl group such as a phenyl group and a benzyl group, the reactivity of the reactive silyl group is lowered.

In the general formula (I), R
² represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably 1 to 1 carbon atoms exemplified in the above R ¹ .
It is a monovalent hydrocarbon group selected from an alkyl group having 4 to 4 carbon atoms, preferably an aryl group having 6 to 25 carbon atoms such as phenyl group, and an aralkyl group having preferably 7 to 12 carbon atoms such as benzyl group. Among these, an alkyl group having 1 to 4 carbon atoms is preferable because the curable resin composition of the present invention is excellent in curability.

In the above general formula (I), the general formula: (R
^The site represented by ¹ O) _3-a is selected so that 3-a is 1 or more and 3 or less, that is, a is 0, 1 or 2, and the obtained curable resin composition is From the standpoint that the curability is improved, a is preferably 0 or 1. Therefore, the number of bonds of R ² is preferably 0 or 1.

When the number of R ¹ O or R ² present in the general formula (I) is 2 or more, the R ¹ O or R ² contained in 2 or more may be the same, It may be different.

Specific examples of the reactive silyl group bonded to the carbon atom represented by the general formula (I) include, for example, the general formula (III):

[0028]

[Chemical 7]

(Wherein R ¹ , R ² and a are the same as those described above, R ⁵ is a hydrogen atom or a methyl group, R ⁶ is a hydrogen atom or --CH _2- ) Examples thereof include a reactive silyl group contained in a monomer having a polymerizable double bond and a reactive silyl group bonded to a carbon atom.

Further, the acrylic copolymer (A) contains a reactive silyl group bonded to a carbon atom represented by the general formula (I) in its molecule from the viewpoint of easy synthesis. Those containing a monomer unit are preferable. The content of the monomer unit in the acrylic copolymer (A) is such that the coating film formed from the curable resin composition of the present invention has excellent durability and high mechanical strength. From the viewpoint, it is desirable that the amount is 3 to 90% by weight, preferably 5 to 70% by weight, and more preferably 10 to 50% by weight.

Examples of the monomer unit other than the monomer unit containing the reactive silyl group bonded to the carbon atom represented by the general formula (I) contained in the acrylic copolymer (A) include, for example, Examples thereof include a unit derived from a (meth) acrylic acid derivative described below and a unit derived from another monomer used as necessary, which will be described later.

The number average molecular weight of the acrylic copolymer (A) is 1000 because the coating film formed from the curable resin composition of the present invention has excellent physical properties such as durability.
It is preferable that it is -30000, especially 3000-25000.

In the present invention, the acrylic copolymer (A) may be used alone or in admixture of two or more.

The method for producing the acrylic copolymer (A) is not particularly limited, and the acrylic copolymer (A) is not particularly limited.
Is, for example, a monomer containing a polymerizable double bond and a reactive silyl group bonded to a carbon atom (hereinafter referred to as monomer (A-
1)), a (meth) acrylic acid derivative (hereinafter referred to as a monomer (A-2)) and, if necessary, another monomer (hereinafter referred to as a monomer (A-3)) are polymerized. Can be manufactured.

Specific examples of the monomer (A-1) include, for example,

[0036]

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Formula (IV) such as:

[0038]

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A compound represented by the formula (wherein R ¹ , R ² , R ⁵ and a are the same as defined above);

[0040]

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General formula (V) such as:

[0042]

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A compound represented by the formula: wherein R ¹ , R ² , R ⁵ and a are the same as defined above, and n is an integer of 1 to 12;

[0044]

[Chemical 12]

General formula (VI) such as:

[0046]

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A compound represented by the formula (wherein R ¹ , R ² , R ⁵ , a and n are the same as defined above);

[0048]

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General formula (VII) such as:

[0050]

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A compound represented by the formula: wherein R ¹ , R ² , R ⁵ and a are the same as defined above, and m is an integer of 1 to 14;

[0052]

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(Wherein p is 0 or an integer of 1 to 20) such as general formula (VIII):

[0054]

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(Wherein R ¹ , R ² , R ⁵ and a are the same as above, q is 0 or an integer of 1 to 22) and a reactive silyl group bonded to a carbon atom. Examples thereof include (meth) acrylate having a terminal via a urethane bond or a siloxane bond, and these can be used alone or in admixture of two or more. Among these, the compound represented by the general formula (V) is preferable from the viewpoint of excellent copolymerizability and polymerization stability, and curability and storage stability of the obtained curable resin composition.

The monomer (A-1) is as described above,
The resulting acrylic copolymer (A) contains 3 to 90% by weight, preferably 5 to 70% by weight, of a monomer unit containing a reactive silyl group bonded to a carbon atom represented by the general formula (I). It is preferable to adjust the content in the polymerization component so that the content is more preferably 10 to 50% by weight.

Specific examples of the monomer (A-2) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate,
i-butyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate,
2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, (Meth) acrylonitrile, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth)
Acrylate, (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth)
Acrylamide, N, N-dimethyl (meth) acrylamide, N-methyl (meth) acrylamide, (meth) acryloylmorpholine, 2-hydroxyethyl (meth)
Acrylate, 2-hydroxypropyl (meth) acrylate, N-methylol (meth) acrylamide, Aronix M-5700, AS-6 which is a macromonomer,
Compounds such as AN-6, AA-6, AB-6, AK-5 (above, Toa Gosei Chemical Industry Co., Ltd.), Placcel
FA-1, Placcel FA-4, Placce
l FM-1, Placcel FM-4 (above, manufactured by Daicel Chemical Industries, Ltd.), phosphate ester groups such as condensation products of hydroxyalkyl esters of (meth) acrylic acid and phosphoric acid or phosphate esters Inclusion (meta)
Examples thereof include acrylic compounds, urethane bond- or siloxane bond-containing (meth) acrylates, and these can be used alone or in admixture of two or more. Among these, the acrylic copolymer (A) obtained is excellent in compatibility with the silicon-containing compound represented by the general formula (II) described below and / or its partially hydrolyzed condensate (B). , N-butyl methacrylate is preferable, and a copolymer obtained by polymerizing the polymerization component containing such n-butyl methacrylate is preferably used as the acrylic copolymer (A).

Polymerization in which the acrylic copolymer (A) contains a monomer containing a reactive silyl group bonded to a carbon atom represented by the general formula (I) and n-butyl methacrylate in the molecule. 3 to 90% by weight of the monomer unit containing the reactive silyl group obtained by polymerizing the components
In the case of the contained copolymer, it is excellent in compatibility with the silicon-containing compound represented by the general formula (II) and / or its partial hydrolysis-condensation product (B), and is obtained from the curable resin composition obtained. Any effect that the formed coating film has excellent durability and its mechanical strength becomes large can be exhibited.

The amount of the monomer (A-2) used may be appropriately adjusted according to the type of the monomer (A-1) to be used and the amount thereof used, and is not particularly limited, but it may be 5 of the total amount of the polymerization components usually used. -93% by weight, preferably 30-90
It is desirable that the amount is, by weight, more preferably 50 to 85% by weight. When n-butyl methacrylate is used as the monomer (A-2), the amount used is 20 to 50% by weight of the total amount of the polymerization components used, which is represented by the general formula (II) described below. It is preferable because the compatibility with the contained compound and / or its partial hydrolysis-condensation product (B) and the balance of various properties of the coating film formed from the curable resin composition obtained are excellent.

Specific examples of the monomer (A-3) include styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene,
Aromatic hydrocarbon vinyl compounds such as vinyltoluene; unsaturated carboxylic acids such as maleic acid, fumaric acid, itaconic acid and (meth) acrylic acid, alkali metal salts of these unsaturated carboxylic acids, ammonium salts, amine salts, etc. An acid anhydride of an unsaturated carboxylic acid such as maleic anhydride, an unsaturated carboxylic acid such as a diester or a half ester of an acid anhydride with a linear or branched alcohol or amine having 1 to 20 carbon atoms. Acid esters;
Vinyl esters such as vinyl acetate and vinyl propionate; allyl compounds such as diallyl phthalate; vinyl group-containing vinyl compounds such as vinyl pyridine and aminoethyl vinyl ether; itaconic acid diamide, crotonic acid amide, maleic acid diamide, fumaric acid diamide, N An amide group-containing vinyl compound such as vinylpyrrolidone; 2
-Hydroxyethyl vinyl ether, methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, fluoroolefin maleimide, N-
Other vinyl compounds such as vinyl imidazole and vinyl sulfonic acid may be mentioned, and these may be used alone or in admixture of two or more.

The above-mentioned monomer (A-3) may be contained in the polymerization component, if necessary, for the purpose of further improving the weather resistance of the coating film formed from the obtained curable resin composition. The content of the monomer (A-3) in the polymerization component is adjusted so that the segment derived from the monomer (A-3) is introduced into the acrylic copolymer (A) in a range not exceeding 50% by weight. It is desirable to do.

In the present invention, similar to the monomer (A-3), for the purpose of further improving the weather resistance of the coating film formed from the curable resin composition obtained, for example, a urethane bond or a siloxane bond is used. The segment incorporated in the molecular chain formed by may be introduced into the main chain of the acrylic copolymer (A) within a range not exceeding 50% by weight.

The acrylic copolymer (A) may contain a group such as a carboxyl group or an amino group. In that case, the curability and the formation of the curable resin composition obtained are obtained. The adhesion of the coating film is improved, but when a carboxyl group or amino group is bonded to its main chain,
It has weak activity, and when these groups are used in place of a curing catalyst to cure a curable resin composition, a siloxane crosslinked structure cannot be formed sufficiently and it has good properties such as weather resistance. Since it may be difficult to obtain a coating film, these groups are preferably bonded to the side chain.

Further, in the acrylic copolymer (A),
A non-aqueous polymer particle (hereinafter referred to as NAD) obtained by non-aqueous dispersion polymerization can be mixed by using an alkoxysilyl group-containing copolymer as a dispersion stabilizer. The use of such an NAD in an extremely small amount has the advantage that the curable resin composition obtained can have a low viscosity and a high solidity, and the impact resistance of the coating film formed can be improved. is there.

When producing the NAD, it is used when producing the acrylic copolymer (A).
For example, polymerization components such as the monomer (A-1), the monomer (A-2), and the monomer (A-3) can be appropriately used.

The method for producing the acrylic copolymer (A) is not particularly limited as described above, and such an acrylic copolymer (A) is disclosed in, for example, JP-A-54-36395.
And a hydrosilylation method described in JP-A-57-55954, for example, a solution polymerization method using a monomer having a reactive silyl group such as monomer (A-1). You can In the present invention,
From the viewpoint of easy synthesis, for example, the monomer (A-
Polymerization of a polymerization component containing a monomer having a reactive silyl group such as 1) by a solution polymerization method using an azo radical polymerization initiator such as azobisisobutyronitrile or azobisdimethylvaleronitrile. It is particularly preferable to manufacture it.

The solvent used in the above solution polymerization method is not particularly limited as long as it is non-reactive, but for example, hydrocarbons such as toluene, xylene, n-hexane and cyclohexane; ethyl acetate, butyl acetate. Acetate esters such as; Cellosolves such as ethyl cellosolve and butyl cellosolve; Ether esters such as cellosolve acetate; Ketones such as methyl ethyl ketone, ethyl acetoacetate, acetylacetone, methyl isobutyl ketone, acetone; methanol, i-propanol, n-butanol , Alcohols such as i-butanol, hexanol, and octanol.

When the solution polymerization method is adopted,
If necessary, for example, n-dodecyl mercaptan, t-
Dodecyl mercaptan, n-butyl mercaptan, γ-
Mercaptopropyltrimethoxysilane, .gamma.-mercaptopropyl triethoxysilane, .gamma.-mercaptopropyl methyl dimethoxy silane, .gamma.-mercaptopropyl methyl diethoxy _{silane, (CH 3 O) 3 Si} -S-S-
_{Si (OCH 3) 3, (} CH 3 O) 3 Si-S 8 -Si
A chain transfer agent such as (OCH ₃ ) ₃ may be used alone or in combination of two or more to adjust the molecular weight of the resulting acrylic copolymer (A). In particular, for example, γ-
It is preferable to use a chain transfer agent having an alkoxysilyl group such as mercaptopropyltrimethoxysilane in the molecule because a reactive silyl group can be introduced into the terminal of the acrylic copolymer (A). The amount of the chain transfer agent used is 0.05 to 10% by weight, preferably 0.1 to 8% by weight, based on the total amount of the polymerization components used.

The silicon-containing compound and / or its partially hydrolyzed condensate (B) (hereinafter, also referred to as silicon-containing compound (B)) used in the present invention, together with the acrylic copolymer (A), While improving the stain resistance of the coating film formed from the curable resin composition of the invention,
It is a component for improving the adhesion between the coating film and the article to be coated.

When the silicon-containing compounds (B) and the acrylic copolymer (A) are mixed, a composition having a room temperature curability is obtained, and a coating film formed from the composition has excellent stain resistance. To have sex.

In the above general formula (II), R ³ is an alkyl group having 1 to 10 carbon atoms, preferably, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl. An alkyl group having 1 to 4 carbon atoms such as a group, an aryl group having preferably 6 to 9 carbon atoms such as a phenyl group, and preferably having 7 carbon atoms such as a benzyl group.
A monovalent hydrocarbon group selected from aralkyl groups of 1 to 9; When the alkyl group has more than 10 carbon atoms,
The reactivity of the silicon-containing compounds (B) is reduced. Also, when R ³ is a group other than the alkyl group, aryl group and aralkyl group, the reactivity of the silicon-containing compound (B) is lowered.

In the general formula (II), R ⁴ is an alkyl group having 1 to 10 carbon atoms, preferably R ⁴
Exemplified alkyl group having 1 to 4 carbon atoms in the ^3, such as, preferably, preferably exemplified in R ³ is exemplified in the aryl group and, for example, R ³ 6-9 carbon aralkyl group having a carbon number of 7 to 9 It is a monovalent hydrocarbon group selected, or preferably an alkoxy group having 1 to 4 carbon atoms such as methoxy group, ethoxy group and propoxy group.

In the general formula (II), the general formula: (R
^The site represented by ³ O) _4-b is selected such that 4-b is 3 or 4, that is, b is 0 or 1, but the curability of the obtained curable resin composition is higher. From the viewpoint of improvement, b is preferably 0.

When the number of R ³ O present in the general formula (II) is 2 or more, the R ³ O contained in 2 or more may be the same or different.

Specific examples of the silicon-containing compound include tetramethyl silicate, tetraethyl silicate, tetra-n-propyl silicate and tetra-i.
-Tetraalkyl silicates such as propyl silicate, tetra-n-butyl silicate, and tetra-i-butyl silicate; methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, octadecyltriethoxysilane, 3- Trialkoxysilanes such as glycidoxypropyltrimethoxysilane, methyltri-sec-octyloxysilane, methyltriisopropoxysilane, and methyltributoxysilane; triaryloxysilanes such as methyltriphenoxysilane.

Specific examples of the partially hydrolyzed condensate of the silicon-containing compound include, for example, those obtained by adding water to the tetraalkyl silicate or trialkoxysilane and condensing the same by a usual method. For example, MSI51, ESI28, ESI40, HA
Partial hydrolysis condensates of tetraalkyl silicates such as S-1 and HAS-10 (all manufactured by Colcoat Co., Ltd.) and partial hydrolysis of trialkoxysilanes such as AFP-1 (manufactured by Shin-Etsu Chemical Co., Ltd.). Examples include decomposition and condensation products.

In the present invention, the silicon-containing compounds (B) may be used alone or in combination of two or more.

Among the silicon-containing compounds (B), the compatibility with the acrylic copolymer (A) and the curability of the resulting curable resin composition are good. A partially hydrolyzed condensate of a tetraalkyl silicate such as MSI51 (a partially hydrolyzed condensate of tetramethyl silicate) or ESI40 (a partially hydrolyzed condensate of tetraethyl silicate) is preferable from the viewpoint that the formed coating film has a high hardness. .

The amount of the silicon-containing compounds (B) used is set so that the acrylic copolymer (A) is used in order to sufficiently improve the stain resistance of the coating film formed from the obtained curable resin composition. Is adjusted to 2 parts or more, preferably 5 parts or more, and more preferably 10 parts or more with respect to 100 parts of the resin solid content, and the appearance such as surface gloss of the coating film is deteriorated or cracks are generated. In order to eliminate the possibility of occurrence, the amount is adjusted to 70 parts or less, preferably 60 parts or less, and more preferably 50 parts or less with respect to 100 parts of the resin solid content of the acrylic copolymer (A).

The curing catalyst (C) used in the present invention is a component for promoting the curing of the mixture of the acrylic copolymer (A) and the silicon-containing compounds (B).
When the curing catalyst (C) is mixed with the acrylic copolymer (A) and the silicon-containing compounds (B), a resin composition having excellent curability is obtained, and a coating film formed from the resin composition. The reason why the composition has excellent stain resistance is not clear, but it is probably due to the relative condensation reaction rate of the acrylic copolymer (A) and the silicon-containing compounds (B), and the formed coating film. It is believed that this is due to the improved surface condition of the.

The curing catalyst (C) may be any as long as it can accelerate the curing of the mixture of the acrylic copolymer (A) and the silicon-containing compounds (B). For example, a silanol condensation catalyst or the like. Is preferably used.

Among the above silanol condensation catalysts, the curability and pot life of the curable resin composition obtained, and
From the viewpoint that the formed coating film has excellent stain resistance, a combination of an organic carboxylic acid or an organic phosphoric acid ester and an organic amine (hereinafter referred to as component (C-1)), an organic metal compound (hereinafter referred to as component) (Referred to as (C-2)) and the component (C-
A combination of 1) and component (C-2) is preferred.

The component (C-1) refers to a mixture or reaction product of the above organic carboxylic acids and organic amines, or a mixture or reaction product of the above organic phosphates and organic amines. .

Examples of the organic carboxylic acids used as the component (C-1) include saturated monovalent carboxylic acids such as butanoic acid, pentanoic acid, hexanoic acid and 2-ethylhexanoic acid; unsaturated monovalent carboxylic acids such as benzoic acid. Carboxylic acid; Saturated polycarboxylic acid such as adipic acid, azelaic acid, sebacic acid, citric acid and succinic acid; Unsaturated polycarboxylic acid such as maleic acid, itaconic acid, phthalic acid, trimellitic acid and pyromellitic acid; Examples thereof include acid anhydrides of these saturated or unsaturated monovalent or polyvalent carboxylic acids; metal salts of saturated or unsaturated monovalent or polyvalent carboxylic acids, etc., which may be used alone or in admixture of two or more. You can

Examples of the organic phosphoric acid ester used as the component (C-1) include monomethyl phosphates such as monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate and monodecyl phosphate; dimethyl phosphate and diethyl. Phosphate, dibutyl phosphate,
Examples thereof include dialkyl phosphates such as dioctyl phosphate and didodecyl phosphate, which may be used alone or in combination of two or more.

Examples of the organic amines used as the component (C-1) include primary amines such as hexylamine, myristylamine and dodecylamine; secondary amines such as distearylamine and di (2-ethylhexyl) amine. Dimethyloctylamine, dimethyldecylamine,
Tertiary amines such as dimethylmyristylamine, dimethylpalmitylamine, dimethylstearylamine, dimethyldodecylamine, triethylamine, trioctylamine; hexamethylenediamine, tetramethylhexamethylenediamine, tetramethylpropylenediamine,
Polyamines such as triethyldiamine; piperazine, N
-Methylmorpholine, N-ethylmorpholine, N,
N ', N "-tris (3-dimethylaminopropyl)
Cyclic amines such as hexahydro S-triazine, trimethylaminoethylpiperazine, N-trioxyethylene-N, N-dimethylenediamine and triethylenediamine, aminoethylaminopropyltrimethoxysilane,
Aminosilane compounds such as γ-aminopropyltrimethoxysilane, γ-aminopropyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyldiethoxysilane; for example, γ-glycidoxypropyltrimethoxysilane, oiled shell epoxy Examples thereof include reaction products of an epoxy compound and an aminosilane compound such as Epicoat 828 and Epicoat 1001 manufactured by Co., Ltd. These may be used alone or in combination of two or more.

Specific examples of the combination of the above-mentioned organic carboxylic acids and organic amines include, for example, propionic acid / laurylamine, butyric acid / monomethyllaurylamine, hexanoic acid / triethylamine, octylic acid / dimethyllaurylamine, 2-ethylhexane. Acid / triethylamine, hexenoic acid / dimethylstearylamine, 2-ethylhexanoic acid / dimethyldodecylamine and the like, a combination of a saturated or unsaturated monovalent carboxylic acid and a primary to tertiary amine; for example, propionic acid / hexamethylenediamine, Butyric acid / N,
A combination of a saturated or unsaturated monovalent carboxylic acid such as N, N ', N'-tetramethylpropylenediamine and hexenoic acid / N, N, N', N'-tetramethylhexamethylenediamine and a polyvalent amine; For example, 2-ethylhexanoic acid / pyridine, hexanoic acid / pyridine, 2-ethylhexanoic acid / piperazine, hexanoic acid / piperazine, propionic acid / N-methylmorpholine, octylic acid / triethylenediamine, lauric acid / trimethylaminoethylpiperazine, hexene. Acid / a combination of a saturated or unsaturated monovalent carboxylic acid such as N-ethylmorpholine and a cyclic amine;
For example, propionic acid / 3-aminopropyltriethoxysilane, butyric acid / 3- (2-aminoethyl) aminopropyltrimethoxysilane, hexanoic acid / 3-ureidopropyltriethoxysilane (NH ₂ CONHC ₃ H ₆ Si
(OC ₂ H ₅ ) ₃ ), 2-ethylhexanoic acid / γ-aminopropyltriethoxysilane, hexenoic acid / 3- (2
A combination of a saturated or unsaturated monovalent carboxylic acid such as -aminoethyl) aminopropyltrimethoxysilane and an aminosilane compound; 2-ethylhexanoic acid / 3-aminopropyltriethoxysilane and a diglycidyl ether of bisphenol A 2 1 (molar ratio), condensate of hexenoic acid / 3- (2-aminoethyl) aminopropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane 1: 2.2 (molar ratio) A combination of a saturated or unsaturated monovalent carboxylic acid such as and a reaction product of an aminosilane compound and an epoxy compound; for example, maleic acid / laurylamine, maleic acid / monomethyllaurylamine, maleic acid / dimethyllaurylamine, fumaric acid / laurylamine , Fumaric acid / monomethyllaurylamine, fumaric acid / di Chill laurylamine, succinic acid / laurylamine, succinic acid / monomethyl laurylamine,
Saturated or unsaturated polycarboxylic acid such as succinic acid / dimethyllaurylamine, phthalic acid / laurylamine, phthalic acid / monomethyllaurylamine, phthalic acid / dimethyllaurylamine, trimellitic acid / laurylamine and 1
Combination with primary to tertiary amines; eg maleic acid / hexamethylenediamine, fumaric acid / hexamethylenediamine, phthalic acid / hexamethylenediamine, trimellitic acid / hexamethylenediamine, itaconic acid / propylenediamine, succinic acid / hydrazine A combination of a saturated or unsaturated polycarboxylic acid with a polyamine, such as maleic acid / piperazine, fumaric acid / N-methylmorpholine, phthalic acid / triethylenediamine, trimellitic acid / trimethylaminoethylpiperazine, succinic acid / N-
A combination of a saturated or unsaturated polycarboxylic acid such as ethylmorpholine and a cyclic amine; for example, maleic acid / 3-aminopropyltriethoxysilane, maleic acid / 3-
(2-Aminoethyl) aminopropyltrimethoxysilane, phthalic acid / 3-ureidopropyltrimethoxysilane, trimellitic acid / γ-aminopropyltriethoxysilane, succinic acid / 3- (2-aminoethyl) aminopropyltrimethoxysilane A combination of a saturated or unsaturated polycarboxylic acid such as silane and an aminosilane compound; for example, a 2: 1 (molar ratio) condensate of maleic acid / γ-aminopropyltriethoxysilane and a diglycidyl ether of bisphenol A, 2: 1 (molar ratio) condensate of phthalic acid / γ-aminopropyltriethoxysilane and diglycidyl ether of bisphenol A, trimellitic acid / 3
A saturated or unsaturated polyvalent carboxylic acid such as a condensate of-(2-aminoethyl) aminopropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane in a molar ratio of 1: 2.2, and an aminosilane compound, and Examples thereof include a combination product of an epoxy compound with a reaction product, and these can be used alone or in combination of two or more kinds.

Specific examples of the combination of the above-mentioned organic phosphates and organic amines include, for example, monomethyl phosphate / hexyl amine, monoethyl phosphate / dodecyl amine, monobutyl phosphate / distearyl amine, monooctyl phosphate / diamine. (2-ethylhexyl) amine, dodecyl phosphate / dimethyl dodecyl amine, dimethyl phosphate / hexyl amine,
Examples include monoalkyl phosphates such as dibutyl phosphate / di (2-ethylhexyl) amine, dioctyl phosphate / dimethyloctyl amine, dioctyl phosphate / dimethyl dodecylamine, and combinations of dialkyl phosphate and primary to tertiary amines.
These may be used alone or in combination of two or more.

The component (C-1) may be further mixed with the aminosilane compounds exemplified as the organic amines.

Among the above-mentioned components (C-1), among the combination of organic carboxylic acids and organic amines, a combination of saturated or unsaturated monovalent carboxylic acid and tertiary amine is a curable product. It is preferable from the viewpoint of excellent balance between curability and usable time of the resin composition, and also a combination of an organic carboxylic acid and an aminosilane compound, a combination of an organic carboxylic acid and a reaction product of an aminosilane compound and an epoxy compound, It is preferable because the curability of the curable resin composition and the adhesion of the coating film formed are excellent. In particular, a combination of a saturated or unsaturated monovalent carboxylic acid and an aminosilane compound, and a combination of a saturated or unsaturated monovalent carboxylic acid and a reaction product of an aminosilane compound and an epoxy compound are preferable for the curability and usable time. In addition to the balance with
It is more preferable in terms of excellent curability and adhesion.

In the combination of organic carboxylic acids and organic amines, it is preferable to use 2-ethylhexanoic acid, hexanoic acid or the like as the organic carboxylic acids and dimethyldodecylamine, dodecylamine or the like as the organic amines. It is preferable because the compatibility with the system copolymer (A) and the silicon-containing compounds (B) is good, and the water resistance of the coating film formed is improved.

In the combination of the organic carboxylic acid and the organic amine, the molar ratio of the carboxyl group of the organic carboxylic acid and the amino group of the organic amine (amino group /
With respect to the value of (carboxyl group), the curing rate of the acrylic copolymer (A) and the silicon-containing compounds (B) decreases, the curability of the curable resin composition decreases, and the usable time decreases. In order to eliminate the fear, it is desirable that it is 0.2 or more, preferably 0.5 or more, and 3 or less, preferably 2.5 or less. Since the possibility that the curing rate is lowered to lower the curability or the usable time is shortened may occur in any combination of organic carboxylic acids and organic amines, In the invention, when a combination product of an organic carboxylic acid and an organic amine is used as the curing catalyst (C), a combination product in which the molar ratio of the carboxyl group and the amino group is within the above range is preferably used. More preferable.

Among the above-mentioned components (C-1), among the combination of organic phosphates and organic amines, dioctyl phosphate and dimethyldodecylamine are preferred from the viewpoint of the balance between curing activity and usable time. Particularly preferred is a combination of a dialkyl phosphate with a tertiary amine, such as a combination with.

The organic carboxylic acids or organic phosphoric acid esters and organic amines in the above component (C-1) are
It is preferable to mix them in advance and then add them to the acrylic copolymer (A) and the silicon-containing compounds (B) from the viewpoint of exhibiting curing activity and low stain resistance. Even when the acrylic copolymer (A) contains a carboxyl group or an amino group, if the organic carboxylic acid or the organic phosphoric acid ester and the organic amine are mixed in advance and then added, the acrylic It is prevented that the curing activity and the low stain resistance are less likely to be exhibited due to the influence of these carboxyl groups and amino groups in the copolymer (A).

In the present invention, when the component (C-1) is used as the curing catalyst (C), a dehydrating agent and an alcohol such as an alkyl alcohol, which will be described later, may be added to the component (C-1) for a long time. A curable resin composition exhibiting extremely excellent storage stability can be obtained.

The component (C-2) is an organometallic compound used as a silanol condensation catalyst, and typical examples thereof include organotin compounds, organotitanium compounds, organozirconium compounds and organoaluminum compounds. .

Specific examples of the organotin compound include, for example, dibutyltin bisethylmalate, dibutyltin bisbutylmalate, dibutyltin bisoctylmalate, dibutyltin bisoleyl maleate, dibutyltin dimaleate, dibutyltin dilaurate, dibutyltin fatty acid salt, dibutyltin bismalate. Acetyl acetate, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin oxide, dibutyltin bistriethoxysilicate, dibutyltin alkyl esters such as these reaction products; dioctyltin dilaurate, dioctyltin dimaleate, tin octylate and the like.

Specific examples of the organic titanium compound include:
For example, isopropyl triisostearoyl titanate,
Isopropyl tris (dioctyl pyrophosphate)
Organic titanate compounds such as titanate and bis (dioctyl pyrophosphate) oxyacetate titanate can be used.

Specific examples of the organic zirconium compound include tetrabutyl zirconate, tetrakis (acetylacetonato) zirconium, tetraisobutylzirconate, butoxytris (acetylacetonato) zirconium and the like.

Specific examples of the organic aluminum compound include tris (ethylacetoacetate) aluminum and tris (acetylacetonato) aluminum.

Among the above components (C-2), dibutyltin alkyl ester is formed because the curable resin composition obtained has good curability and the usable time and curability are well balanced. It is preferable in that the contact angle of the coating film becomes small.

In the present invention, the curing catalyst (C) may be used alone, or two or more different types or the same type may be mixed and used.

The amount of the above-mentioned curing catalyst (C) used is in order to impart sufficient curability to the obtained curable resin composition.
The curable resin is adjusted so as to be 0.1 part or more, preferably 0.2 part or more, and more preferably 0.5 part or more with respect to 100 parts of the resin solid content of the acrylic copolymer (A). In order to eliminate the possibility of deterioration in appearance such as surface gloss of the coating film formed from the composition, 20 parts or less, preferably 10 parts, relative to 100 parts of the resin solid content of the acrylic copolymer (A). Hereafter, it is more preferably adjusted to 5 parts or less.

The silane coupling agent (D) used in the present invention is a component for improving the adhesion between the coating film formed from the obtained curable resin composition and the article to be coated.

In the present invention, one of the major characteristics is that the silane coupling agent (D) is used. For example, on a coating film formed from an organic solvent-based paint used as an undercoat paint, particularly an epoxy resin-based paint that is generally used as an intermediate paint for construction,
For example, a resin composition comprising an acrylic copolymer (A), silicon-containing compounds (B) and a curing catalyst (C),
When an attempt is made to form a coating film by coating the resin composition obtained by further mixing the resin composition with an aliphatic hydrocarbon-based adhesion improving component, the adhesion between the coating films is extremely excellent. There are things I can't say. However, the curable resin composition of the present invention can form a coating film having remarkably excellent adhesion to a wide variety of objects to be coated by the action of the silane coupling agent (D). It is effective.

The silane coupling agent (D) is selected from an aromatic amine, a reaction product of an aromatic amine and an epoxysilane compound, and a reaction product of an aromatic carboxylic acid and an amino group-containing silane compound. The silane coupling agent (D) contains an aromatic hydrocarbon group such as a phenyl group, a toluyl group, a tosyl group, a benzyl group and a benzoyl group. The silane coupling agent (D) has an alkoxysilyl group such as a methoxysilyl group or an ethoxysilyl group as an inorganic functional group, and a halogen group, a vinyl group, a methacryloxy group, a cyclic epoxy group as an organic functional group, Those having both a glycidoxy group, a mercapto group, an amino group, a diamino group and a ureido group are preferably used. Among them, the use of one having an alkoxysilyl group and an amino group or a glycidoxy group is particularly preferable because the coating film formed from the obtained curable resin composition has excellent adhesion.

The silane coupling agent (D) used in the present invention is, as described above, an aromatic amine, a reaction product of an aromatic amine and an epoxysilane compound, and an aromatic carboxylic acid and an amino group-containing silane compound. It is selected from the reactants.

Examples of the aromatic amines include aniline, benzylamine, benzoylamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, and the like. These are used alone or in combination of two or more. be able to.

Examples of the epoxysilane compound include γ-glycidoxypropyltrimethoxysilane and γ-
Examples thereof include glycidoxypropyltriethoxysilane and β-epoxycyclohexylethyltriethoxysilane. These can be used alone or in admixture of two or more.

The method for obtaining the reaction product of the aromatic amine and the epoxysilane compound is not particularly limited, and for example, using an organic solvent such as xylene, methanol, organic esters, etc., at about 50 to 90 ° C. for about 1 to 5 hours. A reaction method or the like can be adopted. The ratio of the aromatic amine and the epoxysilane compound when obtaining such a reaction product is in consideration of the ratio of functional groups (the amino group in the aromatic amine and the epoxy group in the epoxysilane compound) capable of reacting. The aromatic amine: epoxysilane compound (molar ratio) is preferably about 1: 0.5 to 1: 1.

Examples of the aromatic carboxylic acids include benzoic acid, salicylic acid, isophthalic acid, terephthalic acid,
Examples thereof include aromatic carboxylic acids such as trimellitic acid, and anhydrides of the aromatic carboxylic acids. These can be used alone or in admixture of two or more.

In the aromatic carboxylic acids, the valence of the carboxylic acid is preferably as large as possible in consideration of the adhesion of the coating film formed from the curable resin composition obtained, but the silane coupling agent (D) and other Considering the compatibility and the adhesiveness with the component (1), it is preferably 1 to 4, especially 1 to 2. Among the above aromatic carboxylic acids, the anhydrides of the above aromatic carboxylic acids are preferable from the viewpoint of reactivity with the above amino group-containing silane compound.

As the amino group-containing silane compound,
For example, aminoethylaminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyldimethoxysilane, γ-aminopropyldiethoxysilane, 3- (2-aminoethyl) aminopropyl Trimethoxysilane, formula: H ₂ NCONHCH ₃ Si (OC ₂ H
₅ ) ₃ -ureidopropyltriethoxysilane represented by 3 can be used, and these can be used alone or in combination of two or more kinds.

The method for obtaining the reaction product of the aromatic carboxylic acid and the amino group-containing silane compound is not particularly limited, and for example, a method of using an organic solvent such as xylene and reacting at about 50 to 90 ° C. for about 1 to 5 hours. Can be adopted. In addition, the ratio of the aromatic carboxylic acid and the amino group-containing silane compound in obtaining such a reaction product is a functional group capable of reacting (the carboxyl group in the aromatic carboxylic acid and the amino group in the amino group-containing silane compound). In consideration of the ratio of 1), it is preferable that the aromatic carboxylic acid: amino group-containing silane compound (molar ratio) is about 1: 1 to 1: 3.

The amount of the silane coupling agent (D) used is adjusted so that the coating film formed from the obtained curable resin composition has sufficient adhesion to the acrylic copolymer (A). The resin solid content is adjusted to 0.1 part or more, preferably 0.2 part or more, and more preferably 0.5 part or more with respect to 100 parts, and the appearance such as surface gloss of the coating film is deteriorated. In order to eliminate the fear, 20 parts or less relative to 100 parts of the resin solid content of the acrylic copolymer (A),
It is adjusted to preferably 10 parts or less, more preferably 5 parts or less.

In the present invention, a part of the silane coupling agent (D) may be replaced with another silane coupling agent (hereinafter referred to as silane coupling agent (D ′)) within a range not impairing the object of the present invention. It may be mixed instead of).

The silane coupling agent (D ') can further improve the adhesion of the coating film formed from the curable resin composition obtained, especially when used in combination with the silane coupling agent (D). It is preferable that it is possible.

Examples of the silane coupling agent (D ') include γ-anilidepropyltrimethoxysilane,
Anilide compounds such as γ-anilidepropyltriethoxysilane, γ-anilidepropyldimethoxysilane and γ-anilidepropyldiethoxysilane; a reaction product of the anilide compound and the epoxysilane compound; and the anilide compound, for example, 1,2- Epoxy cyclohexane,
1,2-epoxy-4-glycidylcyclohexane,
1,2-epoxy-4-vinylcyclohexane, 1,2
A reaction product of an epoxy group-containing alicyclic compound such as epoxycyclohexane such as epoxy-3-methylolsilokuhexane; and the anilide compound, for example, 1,2-diglycidyl phthalate, 1,3-diglycidyl phthalate, 1, Reaction product of epoxy group-containing aromatic carboxylic acid ester such as 4-diglycidyl phthalate and glycidyl benzoate; Reaction product of the epoxy group-containing aromatic carboxylic acid ester and the amino group-containing silane compound; Epoxy group-containing alicyclic group A reaction product of a compound and an amino group-containing silane compound; an amino group-containing silane compound; an epoxy silane compound; a reaction product of the amino group-containing silane compound and an epoxy silane compound, and the like, which may be used alone or in combination of two or more. It can be mixed and used.

Among these, a good balance of compatibility with the acrylic copolymer (A) and the silicon-containing compounds (B) is obtained, and a coating film formed from the curable resin composition obtained is obtained. In terms of good adhesion,
A reaction product of an anilide compound and an epoxy group-containing alicyclic compound and a reaction product of an epoxy group-containing aromatic carboxylic acid ester and an amino group-containing silane compound are preferable. In addition,
In the epoxy group-containing alicyclic compound and epoxy group-containing aromatic carboxylic acid ester used in these reactants, the number of epoxy groups is preferably as large as possible in consideration of the adhesiveness of the coating film formed, but the silane cup Considering the compatibility and adhesiveness between the ring agent (D ′) and the other components as well, it is preferably 1 to 4, especially 1 or 2.

When the silane coupling agent (D ') is used, the silane coupling agent is taken into consideration in consideration of the adhesiveness and surface gloss of the coating film formed from the curable resin composition obtained. It is desirable to adjust so that 10 to 90% by weight, preferably 15 to 85% by weight of (D) can be replaced.

The method for producing the curable resin composition for a topcoat of the present invention is not particularly limited, and such a curable resin composition can be prepared, for example, by using a resin solid content of 1% of the acrylic copolymer (A).
2 to 7 of silicon-containing compounds (B) with respect to 00 parts
The amount of each component is adjusted so that 0 part, the curing catalyst (C) is 0.1 to 20 parts, and the silane coupling agent (D) is 0.1 to 20 parts, and these components are mixed, for example, with a stirrer or the like. It can be obtained by stirring and mixing so as to obtain a uniform composition. In the present invention, the acrylic copolymer (A) and the silicon-containing compounds (B) are further combined with a dehydrating agent or an alkyl alcohol. By blending, the storage stability of the obtained curable resin composition can be further improved over a long period of time.

Specific examples of the dehydrating agent include methyl orthoformate, ethyl orthoformate, methyl orthoacetate,
Examples thereof include hydrolyzable ester compounds such as ethyl orthoacetate, methyl silicate, and ethyl silicate. These can be used alone or in admixture of two or more.

Specific examples of the alkyl alcohol include, for example, methanol, ethanol and the like having 1 carbon atom.
To lower alcohols, etc., which may be used alone or in admixture of two or more.

The dehydrating agent and alkyl alcohol may be added to the polymerization component before the polymerization for obtaining the acrylic copolymer (A), or may be added during the polymerization of the acrylic copolymer (A). It may be added at the time of mixing the obtained acrylic copolymer (A) with other components such as the silicon-containing compounds (B), and there is no particular limitation.

The blending amount of the dehydrating agent and the alkyl alcohol is not particularly limited, but usually, the total amount of the dehydrating agent and the alkyl alcohol is 0.1 part with respect to 100 parts of the resin solid content of the acrylic copolymer (A). It is desirable to adjust the amount to about 5 to 20 parts, preferably about 2 to 10 parts.

The curable resin composition for top coat of the present invention is usually used in paints such as titanium oxide, ultramarine blue, navy blue, zinc white, red iron oxide, yellow lead, lead white, carbon black, transparent. Pigments such as inorganic pigments such as iron oxide and aluminum powder, azo pigments, triphenylmethane pigments, quinoline pigments, anthraquinone pigments, phthalocyanine pigments and other organic pigments; diluents, ultraviolet absorbers,
Additives such as light stabilizers, anti-sagging agents, and leveling agents; fibrin such as nitrocellulose and cellulose acetate butyrate; epoxy resins, melamine resins, vinyl chloride resins, fluororesins, chlorinated polypropylene, chlorinated rubber, polyvinyl butyral, A resin such as polysiloxane may be appropriately blended by adjusting the amount used within a range that does not impair the object of the present invention.

The curable resin composition for top-coat paint of the present invention is applied to an object to be coated by a conventional method such as dipping, spraying, coating using a brush, etc., and is usually kept at room temperature or at about 30 ° C. Above, it is baked and hardened. In addition, the solid content concentration of the curable resin composition is 30 to 6 in consideration of workability when applied to an object to be coated.
It is preferably about 0% by weight.

The curable resin composition for top coating composition of the present invention has curability at room temperature, has excellent weather resistance and stain resistance, and has excellent adhesion to a wide variety of objects to be coated. Since it is possible to form a coating film that has excellent properties and also has an improved appearance such as surface gloss, for example, metal, ceramics, glass, cement, ceramic moldings, plastics, wood, paper, fibers, etc. It is suitable for use as a top coat paint for buildings, home appliances, industrial equipment, etc.

[0129]

Next, the curable resin composition for a top coating composition of the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to only these Examples.

Production Example 1 (Production of Acrylic Copolymer (A)) 40 parts of xylene was charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introducing tube and a dropping funnel, and nitrogen was added. The temperature was raised to 110 ° C. while introducing gas. After this, 10 parts of γ-methacryloxypropyltrimethoxysilane and 3 parts of methyl methacrylate were placed in this reaction vessel.
0 part, n-butyl methacrylate 45 parts, n-butyl acrylate 14 parts, acrylamide 1 part, xylene 18
Part and 1,2'-azobisisobutyronitrile (1 part) were added dropwise at a constant rate through a dropping funnel over 5 hours.

After the dropping was completed, 0.5 parts of 2,2'-azobisisobutyronitrile and 8 parts of toluene were added dropwise at a constant rate over 1 hour, and then the mixture was aged at 110 ° C for 2 hours and then cooled. Xylene was added to the obtained resin solution, the resin solid content concentration was 50% by weight, and the amount of the monomer unit containing the reactive silyl group bonded to the carbon atom represented by the general formula (I) (hereinafter, referred to as the reactivity An acrylic copolymer (hereinafter referred to as (A) -1) having a silyl group unit amount of 10% by weight was obtained.

The number average molecular weight of the obtained acrylic copolymer (A) -1 was 15,000.

Production Example 2 (Production of Acrylic Copolymer (A)) In Production Example 1, 10 parts of γ-methacryloxypropyltrimethoxysilane was added to 12 parts, 30 parts of methyl methacrylate was added to 55 parts, and n-butyl was added. 14 parts of acrylate 3
Acrylic copolymer (resin solid content concentration of 50% by weight and reactive silyl group unit amount of 12% by weight) was used in the same manner as in Production Example 1 except that the amount was changed to 2 parts and n-butylmethacrylate was not used. Hereinafter, (A) -2) was obtained.

The number average molecular weight of the obtained acrylic copolymer (A) -2 was 15,000.

Production Example 3 (Production of Acrylic Copolymer (A)) In Production Example 1, 10 parts of γ-methacryloxypropyltrimethoxysilane was added to 50 parts, 30 parts of methyl methacrylate was added to 15 parts, and n-butyl was added. 1 part with 14 parts acrylate
5 parts, 45 parts of n-butyl methacrylate to 20 parts,
Resin solid content concentration was 50 in the same manner as in Production Example 1 except that 1 part of azobisisobutyronitrile was changed to 4 parts.
An acrylic copolymer (hereinafter, referred to as (A) -3) containing 50% by weight of reactive silyl group units was obtained.

The number average molecular weight of the obtained acrylic copolymer (A) -3 was 7,000.

Production Example 4 (Production of Silane Coupling Agent (D)) A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube was charged with 69 parts of γ-glycidoxypropyltrimethoxysilane. 100 parts of xylene was charged, and the mixture was stirred while introducing nitrogen gas. Further, 31 parts of benzylamine was added and mixed at room temperature for 1 hour (γ-glycidoxypropyltrimethoxysilane: benzylamine (molar ratio) = 1: 1). After this, the mixture was heated to 70 ° C. and reacted at 70 ° C. for 4 hours. After cooling, infrared spectrum analysis was performed to confirm that absorption by the epoxy group had disappeared, and a reaction product (hereinafter referred to as (D) -1) having a solid content concentration of about 40% by weight was obtained.

Example 1 100 parts of the resin solid content of the acrylic copolymer (A) -1 obtained in Production Example 1 was used as the silicon-containing compounds (B) MSI51 (Tetra Co., Ltd.). 40 parts of titanium oxide (CR-90, manufactured by Ishihara Sangyo Co., Ltd.) was added as a pigment to a mixed solution containing 40 parts of methyl silicate partially hydrolyzed condensate, and 2 hours with a paint conditioner using glass beads. Dispersion gave white enamel with a solids content of 60% by weight.

On the obtained white enamel, dioctyl phosphate (hereinafter referred to as (C) -1), dimethyldodecylamine (hereinafter referred to as (C) -3) and dibutyltin bisoleyl maleate (hereinafter referred to as curing catalyst (C)) were used. ,
(C) -4) is mixed in advance, and then 0.15 parts of (C) -1 and (C) -3 are added to 100 parts of the resin solid content of the acrylic copolymer (A) -1. 0.1
5 parts and (C) -4 were 0.25 parts, and the silane coupling agent (D) -1 obtained in Production Example 4 was added to the resin solid content of the acrylic copolymer (A) -1. It was added so as to be 2 parts per 100 parts. Further, add thinner and stir for 5 minutes using a stirrer to obtain a solid concentration of 4
A 5% by weight curable resin composition was obtained.

The obtained curable resin composition was coated with an epoxy resin intermediate coating (using an amine adduct curing agent, Hypon 30 Mastic intermediate coating, manufactured by Nippon Paint Co., Ltd.) one day in advance. (A505
2P) is coated with air spray so that the dry film thickness is about 30 μm, and the temperature is 23 ° C. (55% relative humidity).
It was cured (cured) for a day to form a coating film.

The epoxy resin-based intermediate coating composition is
A silane other than the acrylic copolymer (A), the silicon-containing compound (B), the curing catalyst (C) and the silane coupling agent (D) used in the present invention is formed on the coating film formed from the intermediate coating composition. It is recognized that when a composition obtained from a coupling agent is applied, the adhesion is poor.

Next, the appearance, stain resistance, weather resistance, contact angle and adhesion of the obtained coating film were examined according to the following methods. Table 1 shows the results.

(A) Appearance (i) Surface condition The coating film surface was visually observed and evaluated based on the following evaluation criteria.

(Evaluation Criteria) A: No cracks were observed and the surface condition was good. B: Partial or minute cracks are recognized. C: Cracks are observed on the whole.

(Ii) Surface gloss The gloss of the coating film surface (60 ° gloss) is measured according to JIS K540.
According to the method described in No. 0, it was measured using a GM268 gloss meter (manufactured by Minolta Co., Ltd.).

(B) Contamination resistance (ΔL value) The color of the coating film surface immediately after formation and the coating film surface after being left outdoors (outdoor exposure) in Settsu City, Osaka Prefecture for 3 months were CR-30.
Each was measured using a 0 color difference meter (manufactured by Minolta Co., Ltd.), and the difference (ΔL value) was determined from the obtained L value (brightness).

(C) Weather resistance (gloss retention) Sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.)
And the gloss (Lu ₀ ) of the coating film surface immediately after formation and 2
The gloss (Lu ₁ ) on the surface of the coating film after 000 hours was measured, and the gloss retention rate (%) after 2000 hours was calculated based on the following formula.

Gloss retention (%) = (Lu ₁ / Lu ₀ ) × 100 (d) Contact angle The static contact angle of the coating film surface immediately after formation with water was measured by a contact angle measuring device (Kyowa Interface Science Co., Ltd. ) CA-S150 type manufactured by).

(E) Adhesiveness: The cross-cut adhesiveness was measured according to the method described in JIS K 5400 and evaluated according to the following evaluation criteria.

(Evaluation Criteria) 10: Each cut is thin, both sides are smooth, and there is no peeling at the intersection of cuts and each square eye. 8: There is a slight peeling at the intersection of cuts, but a square 1
There is no peeling for each eye, and the area of the defective portion is less than 5% of the area of the entire square. 6: There is peeling at the intersection with both sides of the cut, and the area of the defective portion is 5% or more and less than 15% of the area of the entire square. 4: The width of peeling due to cuts is wide, and the area of the defective portion is 15% or more and less than 35% of the area of the entire square. 2: The width of peeling due to cuts is wider than in the case of evaluation 4, and the area of the defective portion is 35% or more of the area of the entire square,
It is less than 65%. 0: The area of the defective portion is 65% or more of the area of the entire square.

Examples 2 to 4 and Comparative Examples 1 to 2 White enamel having a solid content concentration of 60% by weight was prepared in the same manner as in Example 1 except that the composition was changed as shown in Table 1.
A curable resin composition having a solid content concentration of 45% by weight was obtained from this white enamel.

The obtained curable resin composition was applied onto the same aluminum plate as used in Example 1 by air spraying so that the dry coating film would be about 30 μm, and the curing conditions shown in Table 1 were used. It was cured (cured) to form a coating film.

Then, the characteristics of the obtained coating film were examined in the same manner as in Example 1. Table 1 shows the results.

The abbreviations in Table 1 mean the following.

(Acrylic Copolymer (A)) (A) -1: Copolymer Obtained in Production Example 1 (A) -2: Copolymer Obtained in Production Example 2 (A) -3 : Copolymer Obtained in Production Example 3 (Silicon-Containing Compounds (B)) MSI51: Partial Hydrolyzed Condensate of Tetramethylsilicate manufactured by Colcoat Co., Ltd. ESI40: Partial Hydrolysis of Tetraethylsilicate manufactured by Colcoat Co., Ltd. Decomposition condensate (Curing catalyst (C)) (C) -1: dioctyl phosphate (C) -2: 2-ethylhexanoic acid (C) -3: dimethyldodecylamine (C) -4: dibutyltin bisoleyl maleate (C) Silane coupling agent (D)) (D) -1: Reaction product obtained in Production Example 4 (Silane coupling agent (D ′)) (D ′)-1: γ-aminopropyltrimethoxysilane (D ′) ) -2: -Reaction product of glycidoxypropyltrimethoxysilane and aminoethylaminopropyltrimethoxysilane In addition, in Table 1, when a combination product of an organic carboxylic acid and an organic amine is blended as a curing catalyst (C). The values of the molar ratio (amino group / carboxyl group) between the carboxyl groups of the organic carboxylic acids and the amino groups of the organic amines are also shown.

The silicon-containing compounds (B), curing catalyst (C), silane coupling agent (D) in Table 1 were used.
The amounts of the silane coupling agent (D ′) and the silane coupling agent (D ′) are based on 100 parts of the resin solid content of the acrylic copolymer (A).

[0157]

[Table 1]

From the results shown in Table 1, the curable resin compositions obtained in Examples 1 to 4 are those that cure at room temperature, and the coating films formed from the curable resin compositions are Since it has no cracks and has a good surface gloss, it not only has an excellent appearance and excellent weather resistance, but it also has excellent stain resistance and adhesion, and a small contact angle. I understand.

[0159]

The curable resin composition for top coating composition of the present invention has curability at room temperature and excellent weather resistance.
In addition to having excellent stain resistance, it has excellent adhesion to a wide variety of objects and has a small contact angle.
Further, it is possible to form a coating film excellent in appearance such as surface gloss.

Therefore, the curable resin composition for a top coating composition of the present invention is, for example, a building made of metal, ceramics, glass, cement, ceramic molding, plastic, wood, paper, fiber, etc., household appliances, industrial equipment. It can be suitably used for coating such as.

Claims (6)

[Claims] 1. A compound of the general formula (I): (In the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ² is a hydrogen atom or a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, a represents 0, 1, or 2), based on 100 parts by weight of the resin solid content of the acrylic copolymer (A) containing a reactive silyl group bonded to a carbon atom.
General formula (II): (In the formula, R ³ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group,
R ⁴ is a monovalent hydrocarbon group or an alkoxy group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, and b is 0 or 1) and a silicon-containing compound and / or a portion thereof. Hydrolysis condensate (B) 2 to 70 parts by weight, curing catalyst (C) 0.1 to 20 parts by weight, aromatic amine, reaction product of aromatic amine and epoxysilane compound, and aromatic carboxylic acid and amino group A curable resin composition for topcoat paint, comprising 0.1 to 20 parts by weight of a silane coupling agent (D) selected from a reaction product with a contained silane compound. 2. A copolymer in which the acrylic copolymer (A) contains 3 to 90% by weight of a monomer unit containing a reactive silyl group bonded to a carbon atom represented by the general formula (I) in the molecule. The curable resin composition for a topcoat paint according to claim 1, which is a polymer. 3. The curable resin composition for a topcoat paint according to claim 1, wherein the acrylic copolymer (A) is a copolymer obtained by polymerizing a polymerization component containing n-butyl methacrylate. 4. The curable composition for topcoat paint according to claim 1, 2 or 3, wherein the curing catalyst (C) is a combination of an organic carboxylic acid or an organic phosphoric acid ester and an organic amine and / or an organic metal compound. Resin composition. 5. The molar ratio of the carboxyl group of the organic carboxylic acid to the amino group of the organic amine (amino group / carboxyl group) in the combination of the organic carboxylic acid and the organic amine.
5. The curable resin composition for top coating composition according to claim 4, which has a value of 0.2 to 3. 6. The curable resin composition for a topcoat paint according to claim 4, wherein the organometallic compound is dibutyltin alkyl ester.