JPH10183052A - Curable composition for top coating and substrate coated therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable composition which can form a top coating film improved in acid resistance, scratch resistance, appearance and heat curability by mixing a specified vinyl copolymer with a hydrolyzable-silyl-free hydroxyl- containing compound and a solvent. SOLUTION: This composition is obtained by mixing 100 pts.wt. total of 100-30 pts.wt. vinyl copolymer in which the main chain comprises a vinyl copolymer chain, at least one member of each type selected among hydrolyzable silyl groups of formula I (wherein R<1> and R<2> are each H or a monovalent hydrocarbon group selected from among a 1-10C alkyl, an aryl and an aralkyl: and (a) is 0-2), alcoholic hydroxyl groups and phenolic hydroxyl groups are present as terminals and/or side chains, and the main chain and/or side chains have carbonate groups of formula II and which has a hydrolyzable silyl equivalent of 400-10,000g/mol and 0.001-70 pts.wt. hydrolyzable-silyl-free hydroxyl-containing compound having a hydroxyl equivalent of 160g/mol or above and a number- average molecular weight of 1,000-25,000, with at most 250 pts.wt. of a solvent per 100 pts.wt. of the vinyl copolymer, solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an automobile,
Industrial machinery, steel furniture, building interior and exterior, home appliances,
The present invention relates to a curable composition for a top coat suitably used for a plastic product and the like, and a coated article coated with a top coat clear paint containing the composition as a main component. More specifically, a curable composition for a topcoat paint exhibiting excellent acid resistance, scratch resistance, appearance properties, thermosetting properties and the like, and particularly suitable for use as a topcoat paint for automobiles, and a coated article using the composition. About.

[0002]

2. Description of the Related Art Conventionally, melamine resins such as alkyd melamine and acrylic melamine are used for coating automobiles, industrial machines, steel furniture, interior and exterior of buildings, home appliances and plastic products. The main paint is used.

[0003] However, in the case of such a coating material mainly composed of a melamine resin, there is a problem that harmful formalin is generated at the time of curing, and the cured coating film has poor acid resistance, so that it is susceptible to acid rain. In particular, the problem of acid rain caused by air pollution in recent years has become serious, and phenomena such as etching, whitening, and spots appearing on coating films have been observed.

In order to solve the above problems, a blend of a vinyl copolymer having a hydrolyzable silyl group and an acrylic polyol, a vinyl monomer having a hydrolyzable silyl group and a vinyl monomer having an alcoholic hydroxyl group are used. It has been proposed to use a copolymer with a monomer or the like as a coating material (see JP-A-63-132977).

[0005] A blend of a vinyl copolymer having a hydrolyzable silyl group and an acrylic polyol or a copolymer of a vinyl monomer having a hydrolyzable silyl group and a vinyl monomer having an alcoholic hydroxyl group. One of the characteristics of the use of coalescing is that since the hydrolyzable silyl group and alcoholic hydroxyl group form stable siloxane bonds or siloxy bonds and cure, they are used mainly for melamine resins such as acrylic melamine and alkyd melamine. As compared with the case of the soaking, it is possible to form a coating film having excellent acid resistance and weather resistance.

However, a blend of a vinyl copolymer having a hydrolyzable silyl group and an acrylic polyol, or a copolymer of a vinyl monomer having a hydrolyzable silyl group and a vinyl monomer having an alcoholic hydroxyl group. When a copolymer is used, the scratch resistance may not always be sufficient. Although a method of introducing a flexible component having a polyester structure to impart abrasion resistance has been proposed, there is a case where the acid resistance and hardness are rather lowered, and this point is not sufficiently satisfactory.

For example, in the case of a top coat finish of an automobile, there are generally two types, a metallic color finish and a solid color finish. Among them, in the case of solid color finish, alkyd melamine resin paint is used, and a method of heating and curing by one coat and one bake method has been generally adopted, but recently, the finish appearance,
With the demands on various properties such as weather resistance, acid resistance, and scratch resistance becoming stricter, for example, on a solid color finish, an acrylic melamine resin paint, a vinyl copolymer having the hydrolyzable silyl group There has been proposed a method of applying a clear paint such as a paint composed of a blend of styrene and an acrylic polyol, or a paint composed of a vinyl copolymer having a hydrolyzable silyl group and an alcoholic hydroxyl group in the same molecule. In this case, it has been proposed to introduce a flexible component having a polyester structure into the clear coating resin in order to increase the scratch resistance, but it has been found that acid resistance and hardness are not always sufficient.

[0008]

In view of the above circumstances, the present invention not only exhibits excellent acid resistance and abrasion resistance but also balances the properties of a coating film such as weather resistance, appearance and hardness. It has been made to provide an excellent curable composition for a topcoat paint, and a coated article using the same,
(A) The main chain is substantially composed of a vinyl copolymer chain, and the main formula is represented by the general formula (I):

[0009]

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(Wherein R ¹ and R ² are a hydrogen atom or a monovalent hydrocarbon group selected from the group consisting of alkyl, aryl and aralkyl groups having 1 to 10 carbon atoms;
Or 2) having at least one hydrolyzable silyl group and at least one of an alcoholic hydroxyl group and a phenolic hydroxyl group in the molecule, respectively, and in the main chain and / or the side chain. General formula (II):

[0011]

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100 to 30 parts (parts by weight, hereinafter the same) of a vinyl copolymer having a carbonate structure represented by
(B) 0.001 to 70 parts of a hydroxyl group-containing compound not containing a hydrolyzable silyl group and (C) a solvent,
The curable composition for a top coating composition in which the total of the components (A) and (B) is 100 parts (claim 1), wherein the hydrolyzable silyl group of the component (A) is represented by the general formula (III):

[0013]

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Wherein R ¹ and R ² are the same as described above, and R ³ is a hydrogen atom, a methyl group or an ethyl group, and is a group bonded to a carbon atom represented by the formula: The curable composition for a topcoat paint according to claim 1 or 2, wherein the curable composition (Claim 2) and the component (B) are a copolymer of a hydroxyl group-containing vinyl monomer and a hydroxyl group-free vinyl monomer. (Claim 3) The component (B) is composed of at least 5 to 30 parts of at least one kind of hydroxyl group-containing vinyl monomer and at least 70 to 95 parts of at least one kind of vinyl monomer containing no hydroxyl group, for a total of 100 parts. In an organic solvent solution containing an organic solvent-soluble polymer having a number average molecular weight of 1,000 to 25,000, at least one hydroxyl group-containing vinyl monomer and a hydroxyl group-free vinyl monomer The curable composition for a topcoat paint according to claim 1, wherein the curable composition is a non-aqueous-dispersed polymer insoluble in the organic solvent, obtained by dispersion-polymerizing at least one of the following: , (D) a compound containing at least two carboxyl groups in one molecule,
3. The composition according to claim 1, wherein the component (A) and the component (B) are combined in a proportion of 40 parts or less based on 100 parts (solid content) in total.
The curable composition for a topcoat paint according to 3 or 4 (Claim 5), and further comprising (E) a curing catalyst comprising the component (A) and the component (B).
The curable composition for a topcoat paint according to claim 1, 2, 3, 4, or 5, which is blended at a ratio of 10 parts or less based on 100 parts (solid content) in total with the components. The component (E) is a sulfonic acid compound blocked with a nitrogen-containing compound, and the nitrogen-containing compound is composed of a primary or secondary amine compound having at least one hydroxyl group in one molecule, morpholine, and oxazolidine. The curable composition for a topcoat paint according to claim 6, which is at least one member selected from the group (claim 7), and a coating surface on which a paint containing a metallic powder and / or a color pigment is applied. The present invention relates to a coated article (Claim 8) to which a topcoat clear coating composition containing the curable composition for a topcoat coating composition according to Item 1, 2, 3, 4, 5, 6, or 7 as a main component is applied.

In the present specification, the term "vinyl-based" is a word indicating that the compound is derived from a compound having a polymerizable C = C bond, such as a vinyl group and a vinylidene group.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(A) Component In the present invention, the main chain is substantially composed of a vinyl copolymer chain, and the terminal of the main chain and / or the side chain has the general formula (I):

[0017]

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(In the formula, R ¹ and R ² represent a hydrogen atom or a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, and R ¹ or R ² represents When a plurality of groups are present, they may be the same or different; a represents 0, 1 or 2) and a hydrolyzable silyl group (a concept including a silanol group) and an alcoholic hydroxyl group And at least one of phenolic hydroxyl groups (hereinafter also referred to as alcoholic hydroxyl group, etc.) in the molecule, and the main chain and / or the side chain have the general formula (II):

[0019]

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The vinyl copolymer (A) having the carbonate structure represented by the formula (A) (component (A)) is used. Since the main chain of the vinyl copolymer (A) is substantially composed of the vinyl copolymer chain, the weather resistance and chemical resistance of the coating film formed using the obtained curable composition are excellent. In addition, the compound has at least one hydrolyzable silyl group represented by the general formula (I) in the molecule, has curability, and further has a hydrolyzable silyl group represented by the general formula (I). Since it has at least one alcoholic hydroxyl group and the like in the molecule, it has excellent curability under heat-curing conditions, increases the cross-linking density of the cured product, and has a carbonate structure, without reducing acid resistance. Scratch resistance is imparted.

In the vinyl copolymer (A), the number of hydrolyzable silyl groups represented by the general formula (I) may be one or more in the molecule. It is preferable in that the solvent resistance of the coating film formed using the composition is excellent.

As described above, R ¹ in the general formula (I) is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (preferably, for example, a methyl group, an ethyl group, an n-propyl group,
an alkyl group having 1 to 4 carbon atoms such as i-propyl group, n-butyl group, i-butyl group, t-butyl group), an aryl group (for example, a group having 6 to 25 carbon atoms such as phenyl group), an aralkyl group (For example, a benzyl group or the like having 7 to 12 carbon atoms
A monovalent hydrocarbon group selected from Of these, an alkyl group having 1 to 10 carbon atoms, particularly an alkyl group having 1 to 4 carbon atoms, is preferable because the reactivity of the hydrolyzable silyl group is superior when the reactivity is an aryl group or an aralkyl group. . When the carbon number of the alkyl group exceeds 10, the reactivity of the hydrolyzable silyl group tends to decrease.

R ² in the formula (I) is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (preferably R 2
Alkyl group) having 1 to 4 carbon atoms which shows a specific example in ^1, group having 6 to 25 carbon atoms of an aryl group (phenyl group), 7 to 12 carbon atoms such as an aralkyl group (benzyl group
A) a monovalent hydrocarbon group selected from the group consisting of alkyl groups having 1 to 10 carbon atoms and further having 1 to 4 carbon atoms in view of excellent curability of the resulting composition. preferable.

The hydrolyzable silyl group has a general formula (II)
I):

[0025]

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(Wherein R ¹ and R ² are the same as above, and R ³ represents a hydrogen atom, a methyl group or an ethyl group). It is preferable in terms of water resistance, alkali resistance, and acid resistance.

Further, a in formula (I) is 0, 1,
Or 2, from the viewpoint of curability, a is preferably 0 or 1, and particularly preferably 0.

The amount of the hydrolyzable silyl group contained in the vinyl copolymer (A) is determined so that a curable composition exhibiting excellent thermosetting properties, acid resistance, weather resistance and the like can be obtained. A hydrolyzable silyl group equivalent (amount (g) of the vinyl copolymer (A) containing 1 mol of the hydrolyzable silyl group represented by the general formula (I)) of 400 to 10,000 g / mol;
Furthermore, 410 to 7,000 g / mol, especially 450
Preferably it is ５，5,000 g / mol. When the equivalent of the hydrolyzable silyl group is less than 400 g / mol, the internal stress of the cured product becomes large and 10,000 g / mol.
If the molar ratio is exceeded, the curability tends to decrease.

The carbonate structure represented by the general formula (II) contained in the vinyl copolymer (A) is obtained by, for example, radically copolymerizing a vinyl monomer having a carbonate structure as shown in [Chemical Formula 18]. It is a group introduced into the vinyl copolymer (A) by, for example, the vinyl copolymer (A) has a carbonate structure, so that the scratch resistance can be improved without lowering the acid resistance. it can. Further, it is superior in terms of curability, weather resistance, and the like as compared with a case where a compound having a carbonate structure is simply blended with a vinyl polymer. As the amount of the carbonate structure contained in the vinyl copolymer (A), the carbonate structure equivalent (the amount (g) of the vinyl copolymer (A) containing 1 mol of the carbonate structure) is 400 to 5,000 g / mol. Further, it is preferable that the amount is included so as to be 600 to 3,500 g / mol, from the viewpoint of the balance between scratch resistance, acid resistance, curability, and the like.

The vinyl copolymer (A) contains at least one alcoholic hydroxyl group in the main chain and / or the side chain in order to further improve the curability. At least one alcoholic hydroxyl group or the like at the end of the main chain and / or the side chain
When it has 2 to 10, preferably 2 to 10, it has excellent curability under heat-curing conditions.

Equivalent amount of alcoholic hydroxyl groups in the vinyl copolymer (A) (Amount (g) of vinyl copolymer (A) containing at least one mole of at least one of alcoholic hydroxyl groups and phenolic hydroxyl groups) ) Is 400-5,000
g / mol, preferably from 400 to 3,000 g / mol, more preferably from 500 to 2,000 g / mol. If the equivalent weight of the alcoholic hydroxyl group is less than 400 g / mol, the weather resistance of the coating film formed using the obtained curable composition will be reduced,
When the amount is more than 00 g / mol, the thermosetting property of the composition and the scratch resistance and impact resistance of the coating film tend to decrease.

Further, the molar ratio between the alcoholic hydroxyl group and the like and the hydrolyzable silyl group (the alcoholic hydroxyl group and the like / hydrolyzable silyl group) in the vinyl copolymer (A) is excellent in thermosetting and acid resistance. From the viewpoint that a curable composition exhibiting water resistance, weather resistance, water resistance and the like can be obtained.
0, more preferably 0.5 to 7.5, particularly preferably 0.7 to 6.0.

In order to make the molar ratio fall within the above range, for example, a hydrolyzable silyl group-containing vinyl monomer and an alcoholic hydroxyl group used in the production of the vinyl copolymer (A) are used. What is necessary is just to adjust the usage-amount of a vinyl monomer etc. containing.

With regard to the number average molecular weight of the vinyl copolymer (A), the curable composition obtained has excellent thermosetting properties, and the coating film formed using the composition has excellent properties such as durability. From this point, it is preferably 1,000 to 20,000, more preferably 2,000 to 15,000, and especially 3,000 to 10,000.

The vinyl copolymer (A) may be used alone or in combination of two or more.

The vinyl copolymer (A) can be produced, for example, by polymerizing a copolymer component containing the following monomers.

Hydrolyzable silyl group-containing vinyl monomer (monomer (A-1)) Carbonate structure-containing vinyl monomer (monomer (A
-2)) Vinyl monomers containing alcoholic hydroxyl groups (monomer (A-3)) Other copolymerizable monomers (monomer (A-
4)).

However, when the monomer (A-2) has an alcoholic hydroxyl group, etc., the monomer (A-3)
May or may not be used.

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

[0040]

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General formula (IV) such as:

[0042]

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[0043] (wherein, R ^1, R ^2, a is as defined above, R ⁴
Represents a hydrogen atom or a methyl group).

[0044]

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General formula (V) such as:

[0046]

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Wherein R ¹ , R ² , R ⁴ and a are the same as above, and n is an integer of 1 to 12;

[0048]

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General formula (VI) such as:

[0050]

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Wherein R ¹ , R ² , R ⁴ , a and n are the same as defined above,

[0052]

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(Wherein p is an integer of 0 to 20):

[0054]

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Wherein R ¹ , R ² , R ⁴ and a are the same as above, and p is an integer of 0 to 22;
(Meth) acrylates having a hydrolyzable silyl group represented by the general formula (I) at the terminal via a urethane bond or a siloxane bond, and the like. These may be used alone or in combination of two or more. Among these,
The compound represented by the above general formula (V) is preferable because it is easy to handle, inexpensive, and does not generate a reaction by-product.

The amount of the monomer (A-1) used is preferably 5 to 60% (% by weight, hereinafter the same) of the total amount of the copolymer components.
Furthermore, it is 10 to 50%. When the amount of the monomer (A-1) is less than 5%, the acid resistance of a coating film formed using the obtained curable composition tends to be insufficient. Meanwhile, the storage stability of the curable composition tends to decrease.

Examples of the monomer (A-2) include, for example,

[0058]

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(Wherein, r represents an integer of 1 to 10). As a representative example, HEAC-1

[0060]

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(Manufactured by Daicel Chemical Industries, Ltd.). The monomer (A-2) may be used alone.
More than one species may be used in combination.

The amount of the monomer (A-2) used is preferably 5 to 60%, more preferably 7 to 40% of the total amount of the copolymer components. When the use amount of the monomer (A-2) is less than 5%, the scratch resistance of a coating film formed using the obtained composition tends to be insufficient, and when the amount exceeds 50%. Has a tendency that the acid resistance and hardness of the coating film decrease.

Examples of the monomer (A-3) include, for example, 2-hydroxyethyl (meth) acrylate, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate , 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, Alonix 5700 (manufactured by Toa Gosei Chemical Industry Co., Ltd.), 4-hydroxystyrene, HE-10, HE-20, HP-1, H
Acrylic ester oligomer having a hydroxyl group at the terminal such as P-20 (all manufactured by Nippon Shokubai Chemical Industry Co., Ltd.), Blemmer PP series (polypropylene glycol monomethacrylate), Blemmer PE series (polyethylene glycol monomethacrylate), Blemmer PE
P series (polyethylene glycol polypropylene glycol monomethacrylate), Blemmer AP-40
0 (polypropylene glycol monoacrylate), Blemmer AE-350 (polyethylene glycol monoacrylate), UNIOX PKA series, Unisafe PKA series (allylated polyether),
Blemmer GLM (glycerol monomethacrylate)
(Above, manufactured by NOF Corporation) and ε-caprolactone-modified hydroxyalkylvinyl-based copolymerizable compounds obtained by reacting a hydroxyl-containing vinyl compound with ε-caprolactone.

Representative examples of the ε-caprolactone-modified hydroxyalkylvinyl copolymerizable compound include, for example, those represented by the following general formula (VIII):

[0065]

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(Wherein R ⁴ is the same as above, and q is an integer of 1 to 4). Specific examples thereof include Placel FA-1 (when R ⁴ is a hydrogen atom and q is 1), Placel FA-
4 (when R ⁴ is a hydrogen atom and q is 4), Plac
el FM-1 (when R ⁴ is a methyl group and q is 1), Placel FM-4 (when R ⁴ is a methyl group,
(If q is 4) (These are Daicel Chemical Industries, Ltd.)
TONE M-100 (when R ⁴ is a hydrogen atom and q is 2), TONE M-201 (when R ⁴ is a methyl group and q is 1) (all made by UCC), etc. Is raised.

The monomers (A-3) may be used alone or in combination of two or more.

Among the monomers (A-3), 2-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and the like are excellent in acid resistance and water resistance of a coating film formed using the obtained curable composition. -Hydroxyethyl (meth)
Acrylate, 4-hydroxybutyl (meth) acrylate and ε-caprolactone-modified hydroxyalkyl vinyl copolymerizable compound are preferred, and 2-hydroxyethyl (meth) acrylate is particularly preferred.

The amount of the monomer (A-3) used is preferably 5 to 60%, more preferably 7 to 40% of the total amount of the copolymer components. However, as described above, when the monomer (A-2) has an alcoholic hydroxyl group or the like, the monomer (A-3) may not be used. Monomer (A-3)
When the amount used exceeds 60%, the acid resistance and appearance of a coating film formed using the obtained composition tend to be insufficient. In order to obtain the effect of using the monomer (A-3), it is preferable to use 5% or more.

Examples of the monomer (A-4) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, -Ethylhexyl (meth) acrylate, isobornyl (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, methyl glycidyl (meth) acrylate, cyclomer M-100, cyclomer A-20
0 (all manufactured by Daicel Chemical Industries, Ltd.), dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylamide, α
-Ethyl (meth) acrylamide, N-methyl (meth)
Acrylamide, N, N-dimethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, AS-6, AN-6, AA-6, A which are macromonomers
Compounds such as B-6 and AK-5 (all manufactured by Toa Gosei Chemical Industry Co., Ltd.), and hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids such as hydroxyalkyl esters of (meth) acrylic acid -Based compounds containing phosphoric acid ester such as condensation products of phenol and phosphoric acid or phosphoric acid esters, (meth) acrylic acid derivatives such as (meth) acrylate containing urethane bond or siloxane bond, styrene, α-methyl Aromatic hydrocarbon vinyl compounds such as styrene, chlorostyrene, styrene sulfonic acid, and vinyl toluene; unsaturated carboxylic acids such as maleic acid, fumaric acid, and itaconic acid; and salts thereof such as alkali metal salts, ammonium salts, and amine salts Acid anhydrides of unsaturated carboxylic acids such as maleic anhydride; Esters of unsaturated carboxylic acids such as diesters and half esters with alcohols having a branched chain; vinyl esters and allyl esters such as vinyl acetate, vinyl propionate and diallyl phthalate; vinyl groups containing amino groups such as vinyl pyridine and aminoethyl vinyl ether Compound; itaconic acid diamide,
Amide group-containing vinyl compounds such as crotonamide, maleic diamide, fumaric diamide, N-vinylpyrrolidone; methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, fluoroolefin maleimide, N- And other vinyl compounds such as vinylimidazole and vinylsulfonic acid. These may be used alone or in combination of two or more.

In particular, glycidyl methacrylate, methyl glycidyl methacrylate, Cyclomer M-100,
Curability can be further improved by using an epoxy group-containing monomer such as Cyclomer A-200. In this case, the amount used is 50% of the total amount of the copolymer components.
% Or less, more preferably 35% or less. When the amount of such an epoxy group-containing monomer is 5
If it exceeds 0%, the water resistance and acid resistance of the coating film formed using the curable composition tend to decrease.

When a polar monomer having an amine, a carboxylic acid, a sulfonic acid or a phosphoric acid group is used as the monomer (A-4), the amount of the monomer used in order to suppress the crosslinking reaction at the time of polymerization is limited. Is preferably 5% or less of the total amount of the copolymer components.

In the present invention, in order to improve the weather resistance, solvent resistance, impact resistance and the like of the coating film formed using the obtained curable composition, the vinyl copolymer (A)
Within the range not exceeding 0%, a segment formed by a urethane bond or a siloxane bond may be included in the main chain of the vinyl copolymer.

The vinyl copolymer (A) used in the present invention comprises a monomer (A-1), a monomer (A-2),
From copolymer components containing the monomer (A-3) and the like, see, for example, JP-A-54-36395 and JP-A-57-5-5.
Although it can be produced by the method described in No. 5954, it is preferably produced by a solution polymerization method using an azo radical polymerization initiator such as azobisisobutyronitrile from the viewpoint of ease of synthesis. .

The polymerization solvent used in the solution polymerization method is as follows:
Non-reactive ones may be used, and there is no particular limitation. For example, hydrocarbons such as toluene, xylene, n-hexane and cyclohexane; acetates such as ethyl acetate and butyl acetate; methanol, ethanol, isopropanol, n Alcohols such as butanol; ethers such as ethyl cellosolve, butyl cellosolve, and cellosolve acetate; ketones such as methyl ethyl ketone, ethyl acetoacetate, acetylacetone, diacetone alcohol, methyl isobutyl ketone, and acetone.

The polymerization solvent may be used alone or in combination of two or more. If the amount of the alcohol such as methanol or butanol in the polymerization solvent is less than 1 part with respect to 100 parts of the copolymerization component, the polymerization solvent may be used. In the meantime, since there is a possibility of gelling during polymerization, it is preferable that the polymerization solvent contains 1 to 30 parts of alcohols per 100 parts of the copolymerization component.

The molecular weight of the obtained vinyl copolymer (A) may be adjusted by using a chain transfer agent during the solution polymerization.

Specific examples of the chain transfer agent include, for example, n-dodecyl mercaptan, tert-dodecyl mercaptan, n-butyl mercaptan, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyl Dimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, (CH ₃ O) ₃ Si—S—S—Si (OC
H _{3) 3,} and _{(CH 3 O) 3 Si-} S 8 -Si (OCH 3) 3 and the like. These may be used alone or in combination of two or more.

For example, when a chain transfer agent having a hydrolyzable silyl group in the molecule, such as γ-mercaptopropyltrimethoxysilane, is used, a hydrolyzable silyl group is added to the terminal of the main chain of the vinyl copolymer (A). It is preferable because a group can be introduced.

The use amount of such a chain transfer agent is preferably about 0.1 to 10% with respect to the copolymer component.

Component (B) The hydroxyl-containing compound containing no hydrolyzable silyl group (component (B), hereinafter also referred to as hydroxyl-containing compound (B)) may or may not be a vinyl (co) polymer. The hydroxyl equivalent (g / mol) is preferably 160 or more, more preferably 240 or more, particularly 400 or more, but 5,000 or less, further preferably 4,000 or less, and particularly preferably 3,500 or less. When the hydroxyl equivalent is less than 160, the water resistance tends to decrease. On the other hand, when the hydroxyl group equivalent exceeds 5,000, it tends to be difficult to react with the vinyl copolymer (A). The hydroxyl-containing compound (B) is preferably a copolymer of a hydroxyl-containing vinyl monomer and a hydroxyl-free vinyl monomer (hereinafter referred to as a copolymer) in view of the durability of a film (layer) obtained from the composition of the present invention. Acryl polyol).

The amount of the hydroxyl group-containing vinyl monomer used in the acrylic polyol is 5 to 60 times the total amount of the copolymer components.
% Is preferred, and more preferably 7 to 50%. If the amount exceeds 60%, the water resistance of the coating film tends to decrease.

The hydroxyl group-containing vinyl monomer contained as a copolymer component of the acrylic polyol is not particularly limited. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) ) Acrylate, 4-
Hydroxybutyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, 4-hydroxystyrene vinyl toluene,
Alonix 5700, 4- manufactured by Toa Gosei Chemical Industry Co., Ltd.
Hydroxystyrene, HE manufactured by Nippon Shokubai Chemical Industry Co., Ltd.
-10, HE-20, HP-1 and HP-20 (all of which are acrylate oligomers having a hydroxyl group at the terminal), Blenmer PP series (polypropylene glycol methacrylate), Blenmer PE series (manufactured by NOF Corporation) Polyethylene glycol monomethacrylate), Blemmer PEP series (polyethylene glycol polypropylene glycol methacrylate), Blemmer AP-400 (polypropylene glycol monoacrylate), Blemmer AE-350 (polyethylene glycol monoacrylate), UNIOX PKA series, Unisafe PKA series (all Allylated polyether), Blemmer GLM (glycerol monomethacrylate), hydroxyl-containing vinyl compound and ε-capro It is example by reaction of the lactone ε
-Caprolactone-modified hydroxyalkylvinyl copolymerizable compounds. These hydroxyl group-containing vinyl monomers may be used alone or in combination of two or more. Among these hydroxyl group-containing vinyl monomers, particularly, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
-Hydroxybutyl (meth) acrylate is preferred from the viewpoint of acid resistance and compatibility.

The vinyl monomer having no hydroxyl group copolymerizable with these hydroxyl group-containing vinyl monomers is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl ( Meth) acrylate, tert
-Butyl (meth) acrylate, cyclohexyl (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) Acrylate, cyclohexyl (meth) acrylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, (meth) acrylonitrile, unsaturated polycarboxylic acids (maleic acid, fumaric acid, itacone Acid) and a linear or branched alcohol having 1 to 20 carbon atoms, such as diester or half ester; unsaturated polycarboxylic acid esters; styrene, α-methylstyrene, chlorostyrene , Styrene sulfonic acid, 4
Aromatic vinyl compounds such as hydroxystyrene, vinyltoluene and sodium styrenesulfonate; unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid and fumaric acid, alkali metal salts, ammonium salts and amine salts thereof Acid anhydrides of unsaturated carboxylic acids such as maleic anhydride; esters of unsaturated carboxylic acids such as diesters or half esters thereof with alcohols having a linear or branched chain having 1 to 20 carbon atoms; Vinyl acetate and vinyl compounds such as vinyl acetate and vinyl diallyl phthalate propionate; vinyl compounds containing a nitrile group such as (meth) acrylonitrile; vinyl compounds containing an epoxy group such as glycidyl (meth) acrylate; dimethylaminoethyl (meth) acrylate and diethylamino Etch Vinyl compounds containing a basic nitrogen atom such as (meth) acrylate, vinylpyridine and aminoethyl vinyl ether; (meth) acrylamide, itaconic diamide, α-ethyl (meth) acrylamide, crotonamide, maleic diamide, fumaric diamide, Amide group-containing vinyl compounds such as N-vinylpyrrolidone, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloylmorpholine; methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene; Propylene, butadiene, isoprene, fluoroolefin maleimide,
Other vinyl compounds such as N-vinylimidazole and vinylsulfonic acid are exemplified. Among these monomers, it is preferable to be selected from the group consisting of acrylic acid, methacrylic acid, their ester compounds, and styrene for reasons such as copolymerizability and chemical resistance of the resulting cured composition. These vinyl monomers containing no hydroxyl group copolymerizable with the hydroxyl group-containing vinyl monomer may be used alone or in combination of two or more.

The obtained acrylic polyol may contain less than 50% of a segment formed by a urethane bond or a siloxane bond in its main chain.

The acrylic polyol is preferably prepared by solution polymerization using a radical initiator from the viewpoint of easy adjustment of the degree of polymerization.

In solution polymerization, a chain transfer agent such as n-dodecyl mercaptan is used, if necessary, to control the molecular weight.

As the polymerization solvent, a non-reactive solvent is usually used, but it is not particularly limited.

Specific examples of the acrylic polyol include, for example, Armatex 748- manufactured by Mitsui Toatsu Chemicals, Inc.
5M, 748-16AE; Sumitomo Bayer Urethane Co., Ltd.
Desmophen A series manufactured by Dainippon Ink and Chemicals, Inc .;

The acrylic polyols may be used alone or in combination of two or more.

The acrylic polyol is preferably a non-aqueous dispersion polymer from the viewpoint of breaking stress and elongation of the film, and from the viewpoint of adjusting the rheology of the paint.

The non-aqueous dispersion polymer is described in the literature (KE
J. Barrett, Dispersion Polymerization in Organic Med
ia, Jhon Wiley & Sons. London. (1975)), which is a polymer that is stably dispersed in an organic medium. The polymer comprises (1) a core portion and (2)
And an arm portion, wherein the core portion (1) is insoluble in the solvent, while the arm portion (2) is soluble in the solvent. Both can be covalently bonded, for example, by a reaction between a carboxylic acid and an epoxy group.

As the organic solvent, a low-polarity hydrocarbon solvent such as cyclohexane, heptane, mineral spirit and xylene is mainly used. However, alcohols such as methanol and 1-butanol and ketones such as acetone and cyclohexanone may be used in combination as long as the above-mentioned solubility is satisfied.

The core consists of a polymer dispersed in an organic medium. The arm portion (2) itself is a polymer that is soluble in an organic medium, and acts as a stabilizer that forms a steric barrier by binding to the core portion (1).

The core part (1) has a number average molecular weight of 15,0
From 100 to 300,000 macromolecular polymers,
The arm part (2) acts as a stabilizer to form a steric barrier, and is a macromer chain bonded to the core part (1).

The core part (1) comprises a copolymer of a vinyl monomer. Examples of the monomer are not particularly limited, and include, for example, acrylic acid and methacrylic acid, and their alkyl esters, hydroxyalkyl esters, allyl esters, glycidyl esters; styrene; acrylonitrile. These may be used alone or in combination of two or more.

The core portion (1) is composed of at least 10 to 50 parts of at least one vinyl monomer having a hydroxyl group, and more preferably at least 15 to 40 parts of at least one vinyl monomer having no hydroxyl group.
90 parts, and more preferably 60 to 85 parts, for a total of 100 parts. 10 vinyl monomers with hydroxyl groups
When the amount is less than 50 parts, the difference in polarity from the arm portion (2) becomes small, and the dispersed polymer tends to be unstable, and tends to be easily aggregated. The water resistance of the resulting coating film tends to decrease.

In synthesizing the non-aqueous dispersion polymer, first, an arm portion (2), which is a polymer soluble in an organic solvent, is synthesized. There is no problem in adding other additives.

Next, polymerization is carried out by adding a monomer forming the core portion (1), but it is also possible to add a polymer or a solvent corresponding to the arm portion (2) during the polymerization. A monomer used to form the core portion (1),
The method of adding the polymer (2) corresponding to the arm portion, the solvent, or other additives such as a polymerization initiator and a chain transfer agent is not particularly limited. For example, the polymerization may be carried out by adding the entire amount of the core-forming monomer at the beginning of the polymerization of the formation of the core, or may be added at an early stage and then added as the polymerization proceeds. Alternatively, the total amount may be added according to the progress of the polymerization. Also, any components such as a core portion forming monomer, a polymer corresponding to an arm portion, a solvent, and other additives may be mixed and added to the polymerization system, and the remaining components may be separately added at the same time or at different times. May be added. When adding according to the progress of polymerization, it may be added intermittently or continuously, and as long as a desired non-aqueous dispersion polymer having a core portion and an arm portion bonded can be obtained, when to add a monomer or the like There is no particular limitation on the method of addition, the amount at that time, and the like.

The obtained non-aqueous dispersion has a solid content of 50 to 50%.
70%, preferably adjusted to about 60-70%,
It is preferable in terms of stability during synthesis, handling after synthesis, and storage, but is not limited to this range.

The average particle size of the obtained dispersed particles is 100 to
2000 nm is preferred, and more preferably 150-1.
000 nm, especially 200-600 nm. If the average particle size is less than 100 nm, the rheological adjustment of the coating becomes insufficient, and if it is larger than 2000 nm, the storage stability tends to be poor. However, if the rheological adjustment and storage stability are good, the average particle size of the dispersed particles and There is no particular limitation on the average molecular weight.

The arm part (2) bonded to the core part (1) accounts for 10 to 90%, preferably 20 to 50% of the non-aqueous dispersion polymer. When the ratio of the arm portion (2) exceeds 90% of the non-aqueous dispersion polymer, it becomes difficult to obtain a durable cured product. Conversely, when the ratio is less than 10%, the viscosity of the non-aqueous dispersion polymer increases. In some cases, the stability of the non-aqueous dispersion polymer is deteriorated to cause precipitation.

The organic solvent-soluble polymer of the arm portion (2) is at least one of hydroxyl group-containing vinyl monomers.
It comprises 30 parts, preferably 5 to 25 parts, and 70 to 95 parts, preferably 75 to 95 parts, of at least one vinyl monomer not containing a hydroxyl group, for a total of 100 parts. If the amount of the hydroxyl group-containing vinyl monomer is less than 5 parts, the curability tends to decrease. Conversely, if the amount exceeds 30 parts, the solubility in an organic solvent decreases or the stability of the non-aqueous dispersion polymer is insufficient. Tends to be.

The number average molecular weight of the organic solvent soluble polymer is preferably from 1,000 to 25,000, more preferably from 1,000 to 15,000. When the number average molecular weight is less than 1,000, the stability of the non-aqueous dispersion polymer tends to be insufficient. Conversely, 25.0
When it exceeds 00, the polymer of the arm portion becomes difficult to dissolve in the organic medium.

When the hydroxyl group-containing compound (B) is not a non-aqueous dispersion polymer, the number of alcoholic hydroxyl groups in the component (B) is less than 0.1 per R ¹ O—Si group in the component (A). It is preferable to mix the component (A) and the component (B) so that the number is 0.001 or more. When the number is 0.1 or more, the water resistance may decrease, and when the number is less than 0.001, the effect may not be sufficiently exhibited.

When the hydroxyl group-containing compound (B) is a non-aqueous dispersion polymer, the alcoholic content in the arm portion (2) of the component (B) per one R ¹ O—Si group in the component (A) The number of hydroxyl groups is less than 0.2, further less than 0.1.
It is preferable to mix the component (A) and the component (B) so that the number is 001 or more. When the number is 0.2 or more, the water resistance may be reduced, and when the number is less than 0.001, the effect may not be sufficiently exhibited.

In any case, when the number of alcoholic hydroxyl groups increases, acid resistance and water resistance may decrease.

When the hydroxyl group-containing compound (B) is not a vinyl (co) polymer, the hydroxyl equivalent (g / mol)
Is 160 or more, and preferably 240 or more. When the hydroxyl equivalent is less than 160, the water resistance tends to decrease. The upper limit is 5000 or less, more preferably 4000 or less, and particularly 3500 or less.

When the hydroxyl group-containing compound (B) is a vinyl (co)
Specific examples of non-polymers include organic polyols such as polycaprolactone polyol, polyvalerolactone polyol, and polyhexamethylene carbonate polyol. Commercially available products include the PLACCEL series (L2) manufactured by Daicel Chemical Industries, Ltd.
05AL, 305, L312AL, 405D, CD20
5 etc.) can be used.

The component (B) may be used alone or in combination of two or more.

When the component (B) is not a non-aqueous dispersion polymer, the number average molecular weight is preferably from 1,000 to 25,000, more preferably from 1,000 to 15,000. When the number average molecular weight is less than 1,000,
There is a case where the weather resistance and the water resistance are reduced.
If it exceeds 000, the compatibility of the blend may be reduced.

Component (B) is added in an amount of 0.001 to 70 based on a total of 100 parts of components (A) and (B).
Department. When the amount of the component (B) exceeds 70 parts, acid resistance and water resistance may be reduced. A preferred range is 50 parts or less, and a more preferred range is 4 parts.
0 parts or less. In addition, it is preferable to use 0.1 part or more from a point that a clear effect by using component (B) is obtained.

Component (C) Solvents (C) used in the curable composition of the present invention include:
Any organic solvent can be used as long as it can dissolve or stably disperse both the component (A) and the component (B).

Representative examples of the solvents (C) include hydrocarbon solvents such as toluene, xylene, cyclohexane, n-hexane and octane, methanol, ethanol, and the like.
i-propanol, n-butanol, i-butanol,
alcohol solvents such as sec-butanol, t-butanol, ethylene glycol monoalkyl ether,
Ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and solvents such as those used in preparing the vinyl copolymer (A). Is raised. Of these,
Alcohol solvents are preferred in that they give good results in stability, and are more preferably used in combination with a dehydrating agent.

As the solvent (C), the solvent used at the time of polymerization of the component (A) may be used as it is.

The amount of the solvent (C) to be used is not particularly limited. However, if the amount is too large, defects such as wrinkles (foaming phenomenon) may occur in a coating film formed using the obtained curable composition. Vinyl copolymer (A)
Usually 250 parts or less, preferably 20 parts per 100 parts
0 parts or less, more preferably 150 parts or less;
Parts or more, preferably 25 parts or more.

Examples of the dehydrating agent include methyl orthoformate, ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate, trimethyl orthopropionate, triethyl orthopropionate, trimethyl orthoisopropionate, triethyl orthoisopropionate, orthoethyl butyrate. Trimethyl, triethyl orthobutyrate, trimethyl orthoisobutyrate, triethyl orthoisobutyrate; or dimethoxymethane, 1,1-dimethoxyethane, 1,1-dimethoxypropane, 1,1-dimethoxybutane; or
Ethyl silicate (tetraethoxysilane), methyl silicate (tetramethoxysilane), methyltrimethoxysilane and the like can be mentioned. Of these, methyl orthoacetate is preferred from the viewpoint of dehydration effect. These may be used alone or in combination of two or more.

The dehydrating agent may be added at the time of polymerization of the vinyl copolymer (A) or may be added after the polymerization. If the amount of such a dehydrating agent is too large, defects such as pinholes tend to easily occur in a coating film formed using the obtained curable composition,
70 parts or less per 100 parts of the vinyl copolymer (A),
Further, it is desirable to use 50 parts or less, especially 20 parts or less. From the viewpoint of obtaining a clear effect by using a dehydrating agent, it is preferable to use one or more parts, and more preferably two or more parts.

Component (D) The component (D) is a compound containing at least 2, preferably 2 to 6 carboxyl groups in one molecule (carboxyl group-containing compound (D)). It is a component used to improve curability.

The component (D) has a component (D-
1) Half-esterification of a polyol compound and an acid anhydride compound, (D-2) copolymerization of a carboxyl group-containing monomer, and the like. From the viewpoint of the recoat adhesion of the coating film obtained from the composition of the present invention,
The component (D) is preferably the component (D-1).

The amount of component (D) is 40 parts or less, preferably 30 parts or less, and more preferably 25 parts or less, based on 100 parts in total of components (A) and (B). In addition, it is preferable to use 2 parts or more, more preferably 5 parts or more, from the viewpoint that a clear effect can be obtained by using the component (D). If the amount of the component (D) exceeds 40 parts, water resistance and storage stability during coating may be reduced.

Component (D-1): A polyol compound having 2 or more, preferably 2 to 10, hydroxyl groups per molecule, and particularly having 3 to 6 hydroxyl groups in terms of the balance between appearance and curability, and an acid anhydride compound. A half ester (D-1) is obtained by a half esterification reaction.

Examples of the polyol having two or more hydroxyl groups per molecule for synthesizing the component (D-1) include ethylene glycol, 1,2- and 1,3-
Propylene glycol, 1,3-butanediol, 1,
4-butanediol, 2,3-butanediol, 1,6
-Hexanediol, diethylene glycol, pentanediol, dimethylbutanediol, hydrogenated bisphenol A, glycerin, sorbitol, neopentyl glycol, 1,3-octanediol, 1,4-cyclohexanedimethanol, 2-methyl-1,3-propane Diol, 1,2,6-hexanetriol, 1,2,4-
Butanetriol, trimethylolethane, trimethylolpropane, pentaerythritol, quinitol, mannitol, trishydroxyethyl isocyanurate,
Polyhydric alcohols such as dipentaerythritol and trishydroxymethylethane; ring-opened adducts of these polyhydric alcohols with lactone compounds such as γ-butyrolactone and ε-caprolactone; the polyhydric alcohols and tolylene diisocyanate; Adducts of isocyanate compounds such as diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate in excess of alcohol; the polyhydric alcohols and ethylene glycol divinyl ether, polyethylene glycol divinyl ether, butanediol divinyl ether;
Adducts of vinyl ether compounds such as pentanediol divinyl ether, hexanediol divinyl ether and 1,4-cyclohexane dimethanol divinyl ether in excess of alcohol, and polyhydric alcohols and alkoxysilicone compounds such as KR-213;
Condensates with KR-217 and KR-9218 (both trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) in excess of alcohol, and the like. These may be used alone or in combination of two or more.

On the other hand, preferred acid anhydride compounds to be reacted with the polyol compound include hexahydrophthalic anhydride, phthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride and trimellitic anhydride. These may be used alone or in combination of two or more.

The hydroxyl group-containing carboxylic acid oligomer can be obtained by adjusting the ratio of the polyol compound to the acid anhydride compound to be reacted.

The number average molecular weight of the component (D-1) is 2,000
0 or less, and preferably 100 to 1,800.

Component (D-2): at least one carboxyl group-containing monomer, monomer (A-3) and monomer (A
The carboxyl group-containing copolymer (D-2) is obtained by copolymerizing the monomers exemplified in -4) except for the carboxyl group-containing monomer. Examples of the carboxyl group-containing monomer include (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid.

The content of the carboxyl group-containing monomer is as follows:
It is preferably at most 30%. When the content of the carboxyl group-containing monomer exceeds 30%, the compatibility of the compound with the component (A) or the component (B) tends to decrease, or the water resistance of the obtained coating film tends to decrease. .

The carboxyl group-containing copolymer (D-2) has a number average molecular weight of 1,500 to 10,000,
It is preferably from 000 to 7,000.

Component (E) The composition of the present invention may further comprise a curing catalyst as component (E).

The amount of the curing catalyst (E) used is (A)
The amount is 10 parts or less, and more preferably 5 parts or less, based on 100 parts in total of the component and the component (B). By using in this range, curability can be improved. From the viewpoint that a clear effect is obtained by using the component (E), 0.
It is preferable to use 001 parts or more, more preferably 0.1 parts or more. If the amount of the component (E) exceeds 10 parts, the appearance and weather resistance of the coating film tend to decrease.

The component (E) can be used without any particular limitation as long as it is used as a curing catalyst for a compound containing a hydrolyzable silyl group. Specific examples of such component (E) include, for example, dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate,
Organotin compounds such as dioctyltin dimaleate and tin octylate; phosphoric acid, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, dioctyl phosphate Phosphoric acid or phosphate such as decyl phosphate; propylene oxide, butylene oxide, cyclohexene oxide, glycidyl methacrylate, glycidol, acrylic glycidyl ether, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ -Glycidoxypropylmethyldimethoxysilane, Yuka Shell Epoxy Co., Ltd. Cardura E, Yuka Shell Epoxy (Ltd.) of Epikote 828,
Addition reaction product of an epoxy compound such as Epicoat 1001 with phosphoric acid and / or monophosphate; organic titanate compound; organic aluminum compound; organic zinc compound; maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid Acid, succinic acid, phthalic acid,
Carboxylic acid compounds (organic carboxylic acid compounds) such as trimellitic acid and pyromellitic acid, and their acid anhydrides; dodecylbenzenesulfonic acid, p-toluenesulfonic acid,
Sulfonic acid compounds (organic sulfonic acid compounds) such as -naphthalenesulfonic acid and 2-naphthalenesulfonic acid; and nitrogen-containing compounds containing the sulfonic acid compounds (eg, 1-amino-2-propanol, monoethanolamine, diethanolamine, 2- ( Methylamino) ethanol, 2-
Dimethylethanolamine, 2-amino-2-methyl-
Blocked with 1-propanol, diisopropanolamine, 3-aminopropanol, 2-methylamino-2-methylpropanol, morpholine, oxazolidine, 4,4-dimethyloxazolidine, 3,4,4-trimethyloxazolidine, etc. Reacting with amines) (for example, King Industry (KING)
INDUSTRIES) NACURE522
5, NACURE5543, NACURE5925, etc.); amines such as hexylamine, di-2-ethylhexylamine, N, N-dimethyldodecylamine, dodecylamine, DABCO, DBU, morpholine, diisopropanolamine; these amines and acidic phosphate esters And a quaternary ammonium salt such as benzyltriethylammonium chloride or bromide, tetrabutylammonium chloride or bromide, or a phosphonium salt. The curing catalysts may be used alone or in combination of two or more.

Among the above curing catalysts, a sulfonic acid compound blocked with a nitrogen-containing compound is preferred because it has a good balance between curability during baking and storage stability at room temperature. Further, the nitrogen-containing compound is a primary or secondary amine compound having at least one, preferably two or less hydroxyl groups in one molecule (for example, 2-amino-2-amine).
Methyl-1-propanol, diisopropanolamine, etc.), morpholine and oxazolidine. Further, the preferred curing catalyst may be used in combination with the organotin compound, phosphoric acid or phosphoric ester.

The equivalent ratio of the nitrogen-containing compound to the sulfonic acid compound is preferably from 1: 0.75 to 3.0, and more preferably from 1: 1.0 to 2.0. When the amount of the sulfonic acid compound with respect to the nitrogen-containing compound is less than the above range, storage stability at normal temperature and appearance tend to be deteriorated, and when the amount is more than the above range, curability during baking becomes poor. Or the yellowing of the coating film tends to increase.

Others In addition to the components (A) to (E), an amino resin may be added to the composition of the present invention in order to improve curability and appearance.
It is preferable to use 30 parts or less, more preferably 15 parts or less, and especially 5 parts or less, based on 100 parts in total of the component and the component (B). It is preferable to use at least one part, and more preferably at least two parts, from the viewpoint of obtaining a clear effect by using an amino resin. If the amount of the amino resin exceeds 30 parts, the acid resistance tends to decrease.

Specific examples of the amino resin include amino components such as melamine, urea, benzoguanamine, glycol urea, acetoguanamine and dicyandiamide.
Examples include amino resins (methylolated amino resins such as melamine resin, urea resin and guanamine resin) obtained by reaction with aldehydes such as formaldehyde, paraformaldehyde, acetaldehyde and benzaldehyde. Among these, melamine resins are preferred from the viewpoint of improving the finished appearance and having good curability. In addition, the amino resin (for example, a methylolated amino resin) is converted into methyl alcohol, ethyl alcohol, n
-Propyl alcohol, i-propyl alcohol, n-
Those further etherified with an alcohol such as butyl alcohol, i-butyl alcohol, 2-ethylbutanol or 2-ethylhexanol may be used.

Other specific examples of the amino resin include Uvan 20SE and 20SE-60 manufactured by Mitsui Toatsu Chemicals, Inc.
U-Van 128, U-Van 220, U-Van 225, U-Van 20SB, U-Van 20SE-60, U-Van 2
1R, U-Van 22R, U-Van 122, U-Van 28
N-butylated melamine resins such as -60, U-Van 20HS, U-Van 2028, U-Van 202, U-Van 120, U-Van 62, U-Van 69-1, and U-Van 16
9, isobutylated melamine resin such as Uban 2061, butylated urea resin such as Uban 10S-60 and Uban 10R, Cymel 30 manufactured by Mitsui Cytec Co., Ltd.
3, Cymel 232, Cymel 370, Cymel 32
5, Cymel 236, Cymel 738, Cymel 77
1, Cymel 327, Cymel 703, Cymel 70
1, Cymel 266, Cymel 267, Cymel 28
5, Cymel 235, Cymel 238, Cymel 114
1, Cymel 272, Cymel 254, Cymel 20
2, Cymel 1156, Cymel 1158, Cymel 3
00, Cymel 301, Cymel 350, Cymel 73
6 and the like. Of these, Cymel 235, Cymel 238, Cymel 115
An alkyl etherified melamine resin such as 8 is preferred from the viewpoint of curability.

The composition of the present invention contains, in addition to the components (A) to (E), an organopolysiloxane silanol, tetraalkoxysilane, alkyltrialkoxysilane, or a partially hydrolyzed product thereof for further lowering the viscosity. ,
You may add 50 parts or less, and also 30 parts or less with respect to 100 parts (solid content) of total of (A) component and (B) component. If more than 50 parts of the organopolysiloxane silanol is added, the film becomes brittle. Also,
If more than 50 parts of tetraalkoxysilane, alkyltrialkoxysilane, or a partial hydrolyzate thereof is added, the compatibility is reduced or the internal stress is increased.

The weather resistance of the composition of the present invention can be further improved by incorporating a weather resistance improver such as an ultraviolet absorber and a light stabilizer. In particular, by using these together, the weather resistance can be more effectively improved.

Examples of the ultraviolet absorber include benzophenone-based, triazole-based, phenyl salicylate-based, diphenylacrylate-based, and acetophenone-based ones. These may be used alone or in combination of two or more.

Examples of the light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and bis (1,2,2,6,6-pentamethyl-).
4-piperidyl) sebacate, 2- (3,5-tert)
Bis (1,2,2,6,6-pentamethyl-4) -butyl-4-hydroxybenzyl) -2-n-butylmalonate
-Piperidyl) tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6)
-Pentamethyl-4-piperidyl) -1,2,3,4-
Butanetetracarboxylate and the like. These may be used alone or in combination of two or more.

The amount of the ultraviolet absorber used is usually 0.1 to 10 based on 100 parts of the resin solid content of the composition of the present invention.
Parts, more preferably 1 to 5 parts, and the amount of the light stabilizer is usually 0.1 to 10 parts, more preferably 1 to 5 parts, based on 100 parts of the resin solid content of the composition of the present invention. preferable.

The composition of the present invention is useful for coatings for automobiles, industrial machines, steel furniture, interior and exterior of buildings, home appliances, plastics, etc., and is particularly useful as a top coating for automobiles.

As the composition of the present invention, the component (A)
When the composition according to claim 1 comprising the component (C) is used, it not only exhibits acid resistance and abrasion resistance, but also has a good balance of coating film properties such as weather resistance, appearance, and hardness. The effect is obtained.

(A) in the composition according to claim 1
3. In the case of the composition according to claim 2, wherein the hydrolyzable silyl group of the component is a group bonded to a carbon atom represented by the general formula (III), an effect of further improving water resistance and alkali resistance is obtained. Can be obtained.

The composition according to claim 3, wherein the component (B) in the composition according to claim 1 or 2 is a copolymer of a vinyl monomer having a hydroxyl group and a vinyl monomer having no hydroxyl group. Has the effect of further improving the durability of the formed coating film.

The component (B) in the composition according to claim 1, 2 or 3, wherein 5 to 30 parts of at least one kind of hydroxyl group-containing vinyl monomer and 70 to 95 parts of at least one kind of vinyl group monomer not containing hydroxyl group. Total of 100
Number average molecular weight of 1,000 to 25,000
0 in an organic solution containing an organic solvent-soluble polymer, at least one of a hydroxyl group-containing vinyl monomer and at least one of a hydroxyl group-free vinyl monomer.
In the case of the composition according to claim 4, wherein the composition is a non-aqueous polymer insoluble in the organic solution, which is obtained by dispersion polymerization of a seed and the like. And the effect of improving the rheology of the paint is improved.

The composition according to claim 1, 2, 3 or 4, further comprising: (D) a compound containing at least two carboxyl groups in one molecule, wherein the compound (A) and the component (B) are combined. When the composition according to claim 5 is blended in a proportion of 40 parts or less with respect to 100 parts (solid content), the effect of further improving recoat adhesion and hardness can be obtained.

The composition according to claim 1, 2, 3, 4 or 5, wherein 10 parts by weight of the curing catalyst (E) is added to 100 parts (solid content) of the total of the components (A) and (B). When the composition according to claim 6 is blended in the following ratio, the effect of further improving the curability can be obtained.

(E) in the composition according to claim 6
The component is a sulfonic acid compound blocked with a nitrogen-containing compound, wherein the nitrogen-containing compound is selected from the group consisting of a primary or secondary amine compound having at least one hydroxyl group in one molecule, morpholine and oxazolidine. In the case of at least one selected from the composition of claim 7, the effect of further improving the balance between curability at the time of baking and storage stability at room temperature can be obtained.

Next, an example when the composition of the present invention is applied will be described.

First, a coating material containing a metallic powder and / or a coloring pigment is applied to an object to be coated (substrate), and then a topcoat clear coating material containing the composition of the present invention as a main component is applied to the coated surface. I do.

The coating (base coat) containing the metallic powder and / or the coloring pigment is not particularly limited, and examples thereof include amino alkyd resins, oil-free alkyd resins, thermosetting acrylic resins, thermosetting urethane resins, nitrified cotton lacquers, and the like. Modified acrylic lacquer, slate acrylic lacquer, room temperature curing urethane resin, acrylic enamel resin, oxidation curing alkyd resin, oxidation curing modified (CAB etc.) alkyd resin, room temperature or heat curing type fluorine resin, resin containing hydrolyzable silyl group, the present invention The composition and the mixture of these as the main component,
Specific examples include those containing a metallic powder and a coloring pigment.

The coating containing the metallic powder and / or the coloring pigment may be, for example, a solution type coating using an organic solvent as a medium, a non-aqueous dispersion coating, a multi-component type coating, a powder coating, a slurry coating, an aqueous coating and the like. Any type of paint may be used.

The metallic powder and the coloring pigment are not particularly limited, and those conventionally used can be used. Specific examples of the metallic powder include, for example, aluminum powder, copper powder, mica powder,
Specific examples of the coloring pigment include, for example, organic pigments such as phthalocyanine blue, toluidine red, and benzidine yellow; and inorganic pigments such as titanium oxide, carbon black, and red iron oxide. These metallic powders and color pigments may be used alone or in combination of two or more.

When the above-mentioned ultraviolet absorber and light stabilizer are added to the base coat, the weather resistance of the coated product can be further improved.

Further, in order to improve the adhesion between the paint film containing the metallic powder and / or the color pigment and the top coat clear paint film, tetraalkoxy silane, alkyl trialkoxy silane, and a part thereof are used. A silicon compound such as a hydrolyzate, an aminosilane-based compound, or an epoxysilane-based compound, and preferably an aminosilane-based compound may be added. In this case, the amount of the silicon compound is usually 20 parts with respect to 100 parts of the paint containing the metallic powder and / or the color pigment.
Parts or less, preferably 10 parts or less and 0.5 parts or more.

The coated article of the present invention is obtained by further applying a top coat clear coating on the surface to which the base coat has been applied. For example, a coating containing the above-mentioned metallic powder and / or coloring pigment is coated on the coated article. After applying and setting for a few minutes, apply a top coat clear paint in a wet-on-wet method and apply heat-cured two-coat one-bake method, or apply a paint containing metallic powder and / or color pigment. It can be manufactured by a method such as a two-coat two-bake method in which a top coat clear paint is applied after heating and curing, followed by heating and curing.

The above-mentioned top coat clear paint is a paint containing the composition of the present invention as a main component, that is, a paint containing 50% or more, and more preferably 75% or more and 100% or less. Examples thereof include an ultraviolet absorber, a light stabilizer, a rheology control agent, a leveling agent and the like.

The application of the top coat clear paint can be carried out by various conventional methods such as dipping, spraying, brushing, using a roll coater or a flow coater. After that, 30 ° C. or more, preferably 55 to 350 ° C., and more preferably 60 to 220 ° C.
It can be cured by heating to ° C.

The thickness of the coating film of the coated product cannot be specified unconditionally because it differs depending on the application. However, the thickness of the coating film containing the metallic powder and / or the coloring pigment is preferably 10 to 30 μm from the viewpoint of concealability and the like. The thickness is preferably in the range, and the thickness of the top coat clear coating film is preferably in the range of 20 to 60 μm from the viewpoint of durability and the like.

The coated product of the present invention thus obtained exhibits excellent acid resistance, stain resistance, scratch resistance, weather resistance, appearance, hardness and the like.

[0163]

EXAMPLES Next, the curable composition for a top coating composition of the present invention and the coated product using the same will be described in more detail with reference to Examples. However, the present invention is not limited to only these Examples. Absent.

Synthesis Example 1 (Components (A-1) to (A-5)
(Synthesis of component (B-1), components (a-6) to (a-10) and component (D-2)) Reaction provided with stirrer, thermometer, refluxer, nitrogen gas inlet tube and dropping funnel [Part 2] in Tables 1 and 2 was charged into a vessel, and while the temperature was raised to 115 ° C. while introducing nitrogen gas, the mixed solution of [Part 1] was dropped at a constant speed over 4 hours.

Next, the mixed solution of [Part 3] was dropped therein at a constant speed over 0.5 hour. After that, 115 ° C
And then cooled to room temperature. Finally,
The mixed solution of [Part 4] was added and stirred.

The solids concentration of the obtained solution, the number average molecular weight of the copolymer (measured by gel permeation chromatography (GPC)), the silyl group equivalent, the alcoholic hydroxyl group equivalent, and the epoxy group equivalent are shown in Tables 1 and 2. It was also described in.

In Tables 1 and 2, A-17
4 is γ-trimethoxysilylpropyl methacrylate (manufactured by Nippon Unicar Co., Ltd.), AIBN is 2,2′-azobisisobutyronitrile, V-59 is 2,2′-azobis (2-methylbutyronitrile) (Wako Pure Chemical Industries, Ltd.
Solvesso 100 is an aromatic hydrocarbon (manufactured by Exxon Chemical Co., Ltd.) and Y-9936 is γ-triethoxysilylpropyl methacrylate (manufactured by Nippon Unicar Co., Ltd.)
It is.

[0168]

[Table 1]

[0169]

[Table 2]

Synthesis Example 2 (Synthesis of Non-Aqueous Dispersion Polymer (B-2) Component)

[0171]

[Table 3]

[Part 1] shown in Table 3 was charged into a reaction vessel and heated to reflux temperature (97 ° C.). Next, after [Part 2] was added, [Part 3] and [Part 4] were added at a constant speed over 225 minutes.

Initially, it was transparent, but soon after adding [part 3] and [part 4], it became pale blue and became cloudy white after 40 minutes.

Thereafter, [Part 5] was added at a constant speed over 30 minutes, and kept at the reflux temperature for another 90 minutes.

Finally, the excess solvent was removed to give a solid content of 63.
Although 4% cloudy, a stable dispersion without layer separation was obtained.

The resulting dispersion had a Stormer viscosity of 76 KU and an average particle size of 300 nm.

The polymer in the solution containing the organic solvent-soluble polymer (Mw = 3500) in [Part 1] forms the arm portion (2).

Further, the methacrylic acid, 2-
Hydroxyethyl acrylate, methyl methacrylate,
A polymer of methyl acrylate, styrene and glycidyl methacrylate forms the core (1).

Synthesis Example 3 (Carboxylic acid oligomer (D-
Synthesis of 1)) 110 g of propylene glycol monomethyl ether acetate, 35 g of pentaerythritol and 0.07 g of triethylamine were charged into a reactor equipped with a stirrer, thermometer, reflux machine, nitrogen gas inlet tube and dropping funnel, and nitrogen gas was charged. After stirring at 120 ° C. for 15 minutes while introducing, 169 g of methylhexahydrophthalic anhydride was added over 15 minutes. Thereafter, the reaction was carried out at 120 ° C. for 3 hours, and it was confirmed by IR that the absorption of the acid anhydride group (1,785 cm ⁻¹ ) disappeared.

The solid content was 65%, and the number average molecular weight was 80.
It was 8.

Examples 1 to 5 and Comparative Examples 1 to 6 Components obtained in Synthesis Examples 1 to 3 and (D-2) described later
The component and the component (E-1) were blended at the ratio (solid content ratio) shown in Table 4.

In each Example or Comparative Example, 0.4% of a leveling agent (L-1984-50 manufactured by Kusumoto Kasei Co., Ltd.) and an ultraviolet absorber (Ciba Geigy) were used based on the total resin solid content of the obtained mixture. 2% of Tinuvin 384) and 1% of a light stabilizer (Tinuvin 123 manufactured by Ciba-Geigy) were added.

The mixture was diluted with Solvesso 100 (a petroleum aromatic solvent manufactured by Exxon Chemical Co., Ltd.) and adjusted to a viscosity of about 20 to 25 seconds with a Ford cup to obtain a top coat clear coating.

A coated steel plate coated with an epoxyamide-based cationic electrodeposition primer for automobiles and an intermediate coating surfacer was used as a test piece on a mild steel plate which had been degreased and phosphorylated, and a commercially available acrylic melamine resin paint (black Mica base coat).

Next, the top coat clear paint was applied wet-on-wet, set for 20 minutes, and baked at 140 ° C. for 30 minutes.

The dry film thickness was approximately 15 μm for the base coat,
The top coat clear was about 50 μm.

About the obtained coating film, acid resistance, scratch resistance,
The pencil hardness was evaluated by the following method. Table 4 shows the results.

(Acid resistance) 0.5% of a 10% aqueous sulfuric acid solution
c. Drop on a test plate using a pipette,
After heating at 0 ° C. for 30 minutes, the aqueous solution of sulfuric acid was washed off with water, and the state of change on the surface of the coating film was observed and evaluated according to the following criteria.

10 points: No change from before test 9 points: Slight change is observed 8 points: Remains after the circle 7 points: Discoloration or swelling is slightly recognized 5 points: Decrease in gloss or discoloration Recognized 1 point: Film dissolution is recognized

(Scratch Resistance (Gloss Retention)) A test piece (150 mm × 100 mm) on which a coating film was formed was leveled, and an abrasive (JIS 8 type Rohm 1.2%, JIS
11 kinds of loam 1.2%, kaolin 0.6%, neutral detergent 1
% And a mixture of water and 96%) were applied at about 0.05 g / cm ^2, and then the weight covered with kraft paper (diameter of contact surface: 5)
cm, load: 22 g / cm ² ) on the surface.

Before the weight was stroked and after 20 strokes, the gloss of the coating film at 20 ° was measured using a gloss meter (manufactured by Murakami Color Research Laboratory Co., Ltd.). The gloss retention (%) after 20 strokes was determined based on (gloss value after stroke / gloss value before stroke) × 100.

The greater the gloss retention, the better the scratch resistance.

(Pencil hardness) Evaluated according to JIS K 5400.

[0194]

[Table 4]

From the results shown in Table 4, the coating films formed using the coating materials obtained in Examples 1 to 5 were all excellent in acid resistance, scratch resistance, and hardness. It can be seen that the material has an excellent balance of physical properties.

[0196]

According to the present invention, the curable composition for a topcoat paint comprises:
While exhibiting excellent thermosetting properties, the coating film formed therefrom has good acid resistance, scratch resistance, good hardness, and a good balance of coating film physical properties, such as automobiles, industrial machinery, steel furniture, It can be suitably used as an overcoat paint used for interior and exterior of buildings, home appliances, plastic products and the like.

[0197] A coated article obtained by applying the curable composition for a top coat of the present invention has the above-mentioned properties.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiro Nambu 7172-22-20 Tsutsujigaoka, Tarumizu-ku, Kobe-shi, Hyogo

Claims (8)

[Claims] (A) The main chain is substantially composed of a vinyl copolymer chain, and the terminal of the main chain and / or the side chain has the general formula (I): (Wherein, R ¹ and R ² are a hydrogen atom or a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, and a represents 0, 1 or 2. ), At least one of an alcoholic hydroxyl group and at least one of a phenolic hydroxyl group in the molecule, and a compound represented by the general formula (II) in the main chain and / or the side chain. ): (B) 100 to 30 parts by weight of a vinyl copolymer having a carbonate structure represented by the formula, (B) 0.001 to 70 parts by weight of a hydroxyl group-containing compound not containing a hydrolyzable silyl group, and (C) solvents, A curable composition for a top coating composition, wherein the total of the component (A) and the component (B) is 100 parts by weight. 2. The hydrolyzable silyl group of the component (A) has a general formula (III): The curable composition for a topcoat paint according to claim ¹ , wherein R ¹ and R ² are the same as above, and R ³ is a hydrogen atom, a methyl group or an ethyl group. Stuff. 3. The curable composition for a top coat according to claim 1, wherein the component (B) is a copolymer of a hydroxyl group-containing vinyl monomer and a hydroxyl group-free vinyl monomer. 4. The component (B) comprises a total of 100 parts by weight of 5 to 30 parts by weight of at least one kind of a vinyl monomer having a hydroxyl group and 70 to 95 parts by weight of at least one kind of a vinyl monomer having no hydroxyl group. At least one kind of hydroxyl group-containing vinyl monomer and at least one kind of hydroxyl group-free vinyl monomer in an organic solvent solution containing an organic solvent-soluble polymer having a number average molecular weight of 1,000 to 25,000. 4. The curable composition for a topcoat paint according to claim 1, which is a non-aqueous polymer insoluble in the organic solvent obtained by dispersion polymerization of 5. The method according to claim 1, wherein (D) at least 2
The compound having one carboxyl group is added to a total of 100 parts by weight (solid content) of the component (A) and the component (B),
5. The curable composition for a top coat according to claim 1, wherein the curable composition is blended in a proportion of 0 part by weight or less. 6. The composition according to claim 1, further comprising (E) a curing catalyst in an amount of 10 parts by weight or less based on 100 parts by weight (solid content) of the total of the components (A) and (B). 2,
3. The curable composition for a top coat according to 3, 4 or 5. 7. The component (E) is a sulfonic acid compound blocked with a nitrogen-containing compound, wherein the nitrogen-containing compound is a primary or secondary amine compound having at least one hydroxyl group in one molecule. 7. The curable composition for a top coat according to claim 6, which is at least one member selected from the group consisting of morpholine and oxazolidine. 8. The method according to claim 1, wherein the coating surface on which the paint containing the metallic powder and / or the color pigment is applied is applied.
A coated article to which a topcoat clear coating composition containing the curable composition for topcoat coating composition described in 2, 3, 4, 5, 6, or 7 as a main component is applied.