JP2001302968A - Flat coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat coating which is capable of lowering the baking temperature without degrading the storage stability of the coating as well as without reducing the critical film thickness to foaming. SOLUTION: The flat coating composition contains [A] a polyortho ester formed by reacting (a) an ortho ester, (b) a glycol compound and (c) a hydroxyl group-containing compound having in one molecule at least two hydroxyl groups, [B] a compound which has in one molecule at least two groups having the reactivity with a hydroxyl group and [C] a flatting agent. The coated metal plate has a cured coating film of the above flat coating composition formed on a metal plate which may have the surface subjected to formation, by way of or not by way of a primer coating film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matte paint composition and a coated metal sheet formed by forming a coating film of the paint composition.

[0002]

2. Description of the Related Art Conventionally, a metal plate in which paint is applied on a long metal plate, that is, a so-called pre-coated metal plate is formed and processed, and is used for building roofs, outer walls, shutters, kitchen appliances, It is used for electrical products. As a pre-coated metal plate, usually, after forming a primer coating, to improve corrosion resistance, adhesion and the like on the metal plate,
A top coat is formed on the primer coat by coating and baking to form a top coat. Matting paints using silica-based matting agents or organic resin-based aggregates are often used as the top coating.

In general, baking is performed at a high temperature for a short time on a precoated metal plate. However, it is required to lower the baking temperature from the viewpoints of energy saving and matte stability of a matte coating film. In order to lower the baking temperature of the topcoat paint, if the topcoat paint is highly reactive at a low temperature between the base resin and the curing agent, the storage stability of the paint will deteriorate, and the viscosity of the paint will increase during storage, and in some cases, gelation may occur. There was a problem of becoming. In addition, in baking at high temperature for a short time, the orientation of the matting agent is not constant during the coating film forming process, and the surface of the organic aggregate swells and the gloss of the formed coating film is not stable. There was such a problem.

In addition, alcohol is often added to polyester-melamine resin-based top coatings in order to improve storage stability. However, there was a problem that the size became smaller.

It is a primary object of the present invention to provide a coating material which does not degrade the storage stability of the coating material, does not reduce the limit film thickness of the coating, can lower the baking temperature, and has good gloss stability. An object of the present invention is to provide a matte paint capable of forming a film.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, the use of a polyorthoester as a part of a resin component in a matting coating composition has resulted in the above object. And found that the present invention was completed.

Accordingly, the present invention provides a method of [A] (a)

[0008]

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In the formula, R ¹ is a hydrogen atom or a group having 1 to 1 carbon atoms.
Orthoesters represented by (b) α-glycol and β, wherein R ³ is the same or different and each represents an alkyl group having 1 to 4 carbon atoms.
A polyorthoester obtained by reacting at least one glycol compound selected from glycols, and (c) a hydroxyl group-containing compound having at least two hydroxyl groups in one molecule other than the above (b), [B] a hydroxyl group The present invention provides a matte coating composition containing a compound having at least two groups reactive with a compound in one molecule and [C] a matting agent.

The present invention also provides a matte coating composition cured film formed on a metal plate, the surface of which may be subjected to a chemical conversion treatment, with or without a primer film. A coated metal plate is provided.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the matte coating composition of the present invention will be described. The matte coating composition of the present invention comprises the following polyorthoester [A], a compound [B] having at least two groups reactive with a hydroxyl group in one molecule, and a matting agent [C].

Polyorthoester [A] : The polyorthoester which is the component [A] in the composition of the present invention is a reaction product of an orthoester (a), a glycol compound (b) and a hydroxyl group-containing compound (c) described below. Things.

Orthoester (a) : The orthoester (a) is represented by the following formula (1)

[0014]

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In the formula, R ¹ is a hydrogen atom or a group having 1 to 1 carbon atoms.
And R ³ is the same or different and each represents an alkyl group having 1 to 4 carbon atoms.

In the above formula (1), the alkyl group having 1 to 4 carbon atoms represented by R ¹ or R ² is linear or branched, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-
A butyl group and the like can be mentioned.

Specific examples of the orthoester (a) include:
For example, methyl orthoformate, ethyl orthoformate, propyl orthoformate, butyl orthoformate, methyl orthoacetate,
Examples thereof include ethyl orthoacetate, methyl orthopropionate, ethyl orthopropionate, methyl orthobutyrate, and ethyl orthobutyrate. Of these, methyl orthoformate, ethyl orthoformate, methyl orthoacetate, and ethyl orthoacetate are preferred. . These can be used alone or in combination of two or more.

Glycol compound (b) : The glycol compound as the component (b) is at least one glycol compound selected from α-glycol and β-glycol having two hydroxyl groups in one molecule.

As the α-glycol, particularly, the following formula (2)

[0020]

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In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ are the same or different and are each a hydrogen atom or a carbon atom having 1 to 24 carbon atoms.
An alkyl group, an aralkyl group having 7 to 24 carbon atoms or a phenyl group, or a group in which a part of these groups is substituted with an oxygen atom, and represented by R ³ , R ⁴ , R ⁵ and R ⁶ . The total number of carbon atoms of the group to be formed is in the range of 0 to 24, preferably 0 to 10, and R ⁴ and R ⁵ together with the carbon atom to which they are directly bonded form a cyclic structure. The compound represented by may be suitably used.

In the above formula (2), R ³ , R ⁴ , R ⁵
Or an alkyl group having 1 to 24 carbon atoms which can be represented by R ⁶ is linear, branched or cyclic, and methyl,
Ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, hexyl, n-octyl, 2-ethylhexyl, decyl, dodecyl, octadecyl, cyclohexyl, methylcyclohexyl, cyclohexylmethyl, cyclohexylethyl and the like be able to.

In the above formula (2), R ³ , R ⁴ , R ⁵
Alternatively, as the aralkyl group having 7 to 24 carbon atoms that can be represented by R ⁶ , a phenyl-substituted alkyl group is preferable, and specific examples include a benzyl and phenethyl group.

In the above formula (2), R ³ , R ⁴ , R ⁵
Or a group in which part of an alkyl group, an aralkyl group or a phenyl group represented by R ⁶ is substituted with an oxygen atom, includes an alkoxyalkyl group such as methoxymethyl, ethoxymethyl, propoxymethyl and butoxymethyl; And alkanoyloxyalkyl groups such as acetoxyethyl; phenoxymethyl and phenoxyethyl groups. Equation (2) above
In the above, R ³ , R ⁴ , R ⁵ or R ⁶ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Thus, typical examples of the above α-glycol include, for example, ethylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 2,3
-Butylene glycol, 1,2-hexanediol,
Hydrolysis products of 1,2-dihydroxycyclohexane, pinacol, and long-chain alkyl monoepoxide; fatty acid monoglycerides (α-form) such as glycerin monoacetate (α-form) and glycerin monostearate (α-form); 3-ethoxypropane-1 , 2-diol, 3-phenoxypropane-1,2-diol, and the like.
Of these, ethylene glycol, 1,2
-Propylene glycol, 1,2-hexanediol are preferred.

On the other hand, as β-glycol, among others, the following formula (3)

[0027]

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In the formula, R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are the same or different and are each a hydrogen atom or an alkyl group having 1 to 24 carbon atoms, or an alkyl group having 7 to 24 carbon atoms. An aralkyl group or a phenyl group, or a group in which a part of these groups is substituted with an oxygen atom, and R ⁷ , R ⁸ , R
^9, R ^10, a total of the number of carbon atoms of the groups represented by R ¹¹ and R ¹² in the range of 0-24, also R ⁷ and R ^9, or R ^7, R ⁹ and R ^11, these Which may form a cyclic structure together with the carbon atom directly bonded thereto, can be suitably used.

In the above formula (3), R ⁷ , R ⁸ , R ⁹
As the alkyl group having 1 to 24 carbon atoms represented by R ¹⁰ , R ¹⁰ , R ¹¹ or R ¹² , an alkyl group represented by R ³ , R ⁴ , R ⁵ or R ⁶ in the formula (2) can be used. Can be similarly mentioned.

In the above formula (3), R ⁷ , R ⁸ , R ⁹
The aralkyl group having 1 to 24 carbon atoms which can be represented by R ¹⁰ , R ¹¹ or R ¹² is preferably a phenyl-substituted alkyl group, and specifically includes, for example, benzyl, phenethyl and the like. Can be.

In the above formula (3), R ⁷ , R ⁸ , R ⁹
Examples of the group in which a part of the alkyl group, aralkyl group or phenyl group represented by R ¹⁰ , R ¹¹ or R ¹² is substituted with an oxygen atom include, for example, methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl Alkoxyalkyl groups such as acetoxymethyl and acetoxyethyl; and phenoxymethyl and phenoxyethyl groups.

In the above formula (3), R ⁷ and R ⁹ , or R ⁷ , R ⁹ and R ¹¹ or R ¹² represent a cyclic structure which can be formed together with a carbon atom to which they are directly bonded. Represents a cyclohexyl group, a cyclopentyl group, or the like.

In the above formula (3), R ⁷ , R ⁸ , R
^9, R ^10, R ¹¹ or R ¹² include, among others, is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Thus, typical examples of β-glycol include, for example, neopentyl glycol, 2-methyl-
1,3-propanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol,
2-ethyl-1,3-hexanediol, 2,2-diethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-butyl-2-ethyl-1,3 -Propanediol, 2-phenoxypropane-1,3-diol, 2-methyl-2-phenylpropane-1,3-diol, 1,3-propylene glycol, 1,3-butylene glycol, dimethylolpropionic acid, Methylolbutanoic acid, 2-ethyl-1,3
-Octanediol, 1,3-dihydroxycyclohexane; and fatty acid monoglycerides (β-form) such as glycerin monoacetate (β-form) and glycerin monostearate (β-form). Among these, neopentyl glycol, 2-methyl-1,3
-Propanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol, 2-ethyl-1,3-hexanediol, 2,2-diethyl-
1,3-propanediol, 2,2,4-trimethyl-
1,3-pentanediol, 2-butyl-2-ethyl-
1,3-propanediol is preferred.

(C) Hydroxyl-containing compound : The hydroxyl-containing compound as the component (c) is a compound other than the glycol compound (b) having two or more hydroxyl groups in one molecule.

Examples of the hydroxyl group-containing compound (c) include compounds having two hydroxyl groups other than α-glycol and β-glycol or compounds having three or more hydroxyl groups in one molecule.

Compounds having two hydroxyl groups other than α-glycol and β-glycol include, for example, 1,4
-Butanediol, 1,4-dihydroxycyclohexane, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 3-methyl-1,5
-Pentanediol, 1,4-dimethylolcyclohexane, tricyclodecanedimethanol, 2,2-dimethyl-3-hydroxypropyl-2,2-dimethyl-3-
Hydroxypropionate [this corresponds to the ester of hydroxypivalic acid and neopentyl glycol], bisphenol A, bisphenol F, bis (4
-Hydroxyhexyl) -2,2-propane, bis (4
-Hydroxyhexyl) methane, 3,9-bis (1,1
-Dimethyl-2-hydroxyethyl) -2,4,8,1
0-tetraoxaspiro [5,5] undecane, diethylene glycol, triethylene glycol, polyethylene glycol of tetra or higher, dipropylene glycol,
Tripropylene glycol, tetra- or more polypropylene glycol, copolymers having hydroxyl groups at both ends obtained by copolymerizing ethylene oxide and propylene oxide, linear polyesters having hydroxyl groups at both ends such as polycaprolactone diol, polycarbonate diol And a carboxylic acid adduct of diepoxide.

Examples of the compound having three or more hydroxyl groups include glycerin, diglycerin, triglycerin, pentaerythritol, dipentaerythritol, sorbitol, mannitol, trimethylolethane, trimethylolpropane, and ditrimethylolpropane. , Tris (2-hydroxyethyl) isocyanurate, gluconic acid, polymers containing three or more hydroxyl groups (polyesters containing three or more hydroxyl groups, polyethers, acrylic polymers, ketone resins, phenolic resins, epoxy resins, urethanes Resins, polyvinyl alcohol which is a saponified product of polyvinyl acetate, natural saccharides such as glucose, etc.).

The hydroxyl group-containing compound (c) has a hydroxyl value of 20 to 1850 mgKOH / g, particularly preferably 40 to 165 mgKOH / g.
Those in the range of 0 mgKOH / g can be suitably used.

Production of polyorthoester [A] : In producing the polyorthoester which is the component [A] in the composition of the present invention, the orthoester (a), the glycol compound (b) and the hydroxyl group-containing compound (c) The mixing ratio of is not particularly limited, but the amount of the orthoester (a) is 0.01 to 10 mol, preferably 0.05 to 1 equivalent of the hydroxyl group in the hydroxyl group-containing compound (c).
To 5 mol, more preferably 0.1 to 2 mol, and the amount of the glycol compound (b) is 0.01 to 1 mol.
0 mole, preferably 0.05 to 5 mole, more preferably 0.1 to 2 mole,
It is appropriate from the viewpoint of easy control of the molecular weight.

The polyorthoester [A] can be obtained by subjecting the three components (a), (b) and (c) to a condensation reaction. For example, the above three components are optionally subjected to a condensation reaction in the presence of an organic solvent and an acid catalyst, usually at room temperature to 250 ° C, preferably at a temperature in the range of 70 to 200 ° C for about 1 to 20 hours. Thereby, it can be suitably manufactured.

In the production of the polyorthoester [A], the alkoxyl group of the orthoester (a) undergoes an exchange reaction with the alcohol part of the glycol compound (b) and the hydroxyl group-containing compound (c). At that time, the orthoester (a) usually reacts preferentially with α-glycol or β-glycol, which is a glycol compound (b) having an adjacent hydroxyl group, to form a cyclic structure. That is, the glycol compound (b) is preferentially reacted with the two functional groups (alkoxyl groups) of the trifunctional orthoester (a) to cyclize. The remaining one alkoxy group of the orthoester (a) can react with the hydroxyl group-containing compound (c). Thus, since the polyorthoester [A] does not involve a bridge between molecules in the production thereof, the molecular weight and the viscosity can be suppressed. On the other hand, when the orthoester (a) is directly reacted with the hydroxyl group-containing compound (c) without the presence of the glycol compound (b), a cross-linking reaction occurs between the molecules, and the molecular weight and viscosity of the product increase steadily. . The polyorthoester [A] in the composition of the present invention is obtained by adding the glycol compound (b) to the orthoester (a) and the hydroxyl group-containing compound (c) and reacting them, thereby suppressing an increase in molecular weight or viscosity. It is.

The polyorthoester [A] produced as described above is, for example, an orthoester of the above formula (1), an α-glycol of the above formula (2) and two hydroxyl groups in one molecule. When the compound having the above formula is used as a raw material, the following formula (4)

[0044]

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In the formula, Y ¹ represents a residue obtained by removing two hydroxyl groups from a compound having two hydroxyl groups in one molecule;
¹ , R ³ , R ⁴ , R ⁵ and R ⁶ are as defined above,
In addition, when the orthoester of the formula (1), the β-glycol of the formula (3) and a compound having four hydroxyl groups in one molecule are used as a raw material, The following equation (5)

[0046]

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In the formula, Y ² represents a residue obtained by removing four hydroxyl groups from a compound having four hydroxyl groups in one molecule;
¹ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² can have a structure as defined above.

A group reactive with a hydroxyl group is contained in one molecule.
Compound [B] having at least two compounds [B] : a compound having at least two groups having reactivity with a hydroxyl group as a component [B] in the composition of the present invention (may be abbreviated as “compound [B]”). Is a compound having reactivity with a hydroxyl group, which is capable of forming a cured product by reacting with a hydroxyl group generated by hydrolysis of an orthoester group of the polyorthoester [A] in the composition of the present invention. .

Representative examples of the compound [B] include, for example,
Examples thereof include a polyisocyanate compound, an amino resin, an epoxy group-containing compound, an alkoxysilyl group-containing compound, and a compound having two or more carboxylic acid anhydride groups.

The above-mentioned polyisocyanate compounds include those in which isocyanato groups (NCO groups) are not blocked (hereinafter, may be abbreviated as “non-blocked polyisocyanate compounds”) and those in which isocyanato groups are blocked. (Hereinafter, may be abbreviated as “blocked polyisocyanate compound”).

Examples of the non-blocked polyisocyanate compound include aliphatic diisocyanates such as lysine diisocyanate, hexamethylene diisocyanate, and trimethylhexane diisocyanate; hydrogenated xylylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4 (or 6)-
Cycloaliphatic diisocyanates such as diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate) and 1,3- (isocyanatomethyl) cyclohexane; aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate and diphenylmethane diisocyanate An organic polyisocyanate itself such as a trivalent or higher polyisocyanate such as lysine triisocyanate, or an adduct of each of these organic polyisocyanates with a polyhydric alcohol, a low molecular weight polyester resin or water; Examples of such a cyclized polymer of each organic diisocyanate (for example, isocyanurate), a biuret-type adduct, and the like.

The blocked polyisocyanate compound is
The non-blocked polyisocyanate compound is obtained by blocking an isocyanato group with a blocking agent. Examples of the blocking agent include phenols such as phenol, cresol and xylenol; ε-caprolactam; lactams such as δ-valerolactam, γ-butyrolactam, β-propiolactam; methanol, ethanol, n- or i-propyl. Alcohol, n
Alcohols such as-, i- or t-butyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, benzyl alcohol; formamidoxime; Oximes such as acetoaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzophenone oxime, and cyclohexane oxime; blocking agents such as active methylenes such as dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, and acetylacetone It can be suitably used. By mixing the non-blocked polyisocyanate with the blocking agent, the isocyanate group of the polyisocyanate can be easily blocked.

These polyisocyanate compounds can be used alone or in combination of two or more.

Examples of the amino resin usable as the compound (B) include methylolated amino resins obtained by reacting an amino component such as melamine, urea, benzoguanamine, acetoguanamine, steroganamin, spiroguanamine and dicyandiamide with an aldehyde. Can be
Examples of the aldehyde include formaldehyde, paraformaldehyde, acetaldehyde, and benzaldehyde. Further, those obtained by etherifying the methylolated melamine resin with one or more alcohols are also included in the amino resin. Examples of the alcohol used for etherification include monohydric alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, 2-ethylbutanol, and 2-ethylhexanol. . Among them, a melamine resin obtained by etherifying at least a part of the methylol group of the methylolated melamine resin with a C1-4 monohydric alcohol is preferable.

Specific examples of the melamine resin include Cymel 300, 303, 325, 327, 350, 730, 736, and 738 (all of which are manufactured by Mitsui Cytec Co., Ltd.), and melan. 522, 523
[These are all manufactured by Hitachi Chemical Co., Ltd.], Nicaraq MS
001, MX430, and MX650 (all manufactured by Sanwa Chemical Co., Ltd.), Sumimar M-55, and M-M
100 and M-40S [all of which are Sumitomo Chemical Co., Ltd.]
Methyl etherified melamine resins such as Resin 740 and 747 (all manufactured by Monsanto); Uban 20SE and 225 (all manufactured by Mitsui Toatsu Co., Ltd.), Super Beckamine J820-60 , L
-117-60, L-109-65, 47-508
Butyl etherified melamine resins such as -60, L-118-60, and G821-60 (all manufactured by Dainippon Ink and Chemicals, Ltd.); Cymel 232, 26
6, XV-514 and 1130 (all of which are manufactured by Mitsui Cytec Co., Ltd.), Nikarac MX500, and MX
600, MS35, MS95 [all, all manufactured by Sanwa Chemical Co., Ltd.], Regimin 753, 755 [all, manufactured by Monsanto Co., Ltd.], Sumimar M-66B
Mixed etherified melamine resin of methyl ether and butyl ether such as [manufactured by Sumitomo Chemical Co., Ltd.]. These melamine resins can be used alone or in combination of two or more.

The epoxy group-containing compound which can be used as the compound (B) is a compound having two or more epoxy groups in one molecule, and typical examples thereof include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, Propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-
Hexanediol diglycidyl ether, glycerin diglycidyl ether, diglycerin tetraglycidyl ether, trimethylolpropane triglycidyl ether, 2,6-diglycidylphenyl ether, sorbitol triglycidyl ether, triglycidyl isocyanurate, diglycidylamine, diglycidylbenzyl Amine, diglycidyl phthalate, bisphenol A diglycidyl ether, butadiene dioxide,
Dicyclopentadienedioxide, diester of 3,4-epoxycyclohexenecarboxylic acid and ethylene glycol, 3,4-epoxycyclohexylmethyl-
3,4-epoxycyclohexanecarboxylate,
3,4-epoxy-6-methylcyclohexylmethyl-
3,4-epoxy-6-methylcyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, dicyclopentadiene epoxide glycidyl ether, dipentenedionoxide, adduct of bisphenol A type epoxy resin with ethylene oxide, EPOLID GT300 (trifunctional alicyclic epoxy compound manufactured by Daicel Chemical Industries, Ltd.), EPOLID GT400 (tetrafunctional alicyclic epoxy compound manufactured by Daicel Chemical Industries, Ltd.); EPOLID GT301, GT30
2, GT303 (all of which are manufactured by Daicel Chemical Industries, Ltd., and trifunctional alicyclic epoxy compounds containing a ring-opened ε-caprolactone chain); Eporide GT401, GT40
2, GT403 (all of which are manufactured by Daicel Chemical Industries, Ltd., tetrafunctional alicyclic epoxy compounds having a ring-opened ε-caprolactone chain); Epicoat 828, 834, and 1
001, (all of which are Yuka Shell Epoxy Co., Ltd.)
Bisphenol A type epoxy resin); Epicoat 1
54 (Cresol novolak type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.), celloxides 2081, 2082, and 2083 represented by the following formula (6) (all of which are manufactured by Daicel Chemical Industries, Ltd .; In (6), k = 1 is celoxide 2081, k = 2 is celoxide 2082, and k = 3 is celoxide 2083); Denacol EX represented by the following formula (7):
-411 (manufactured by Nagase Kasei Co., Ltd.) and the like.

[0057]

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In the formula (6), k represents an integer of 1 to 3.

The epoxy group-containing compounds include epoxy group-containing polymerizable unsaturated monomers such as glycidyl (meth) acrylate, allyl glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth) acrylate, and other polymerizable unsaturated monomers. Copolymers with saturated monomers can also be mentioned. Examples of the other polymerizable unsaturated monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. A) C1-24 alkyl (meth) such as acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, and stearyl (meth) acrylate Acrylate; 2-hydroxyethyl (meth) acrylate,
Monoesters of polyhydric alcohols with acrylic acid or methacrylic acid, such as hydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and polyethylene glycol mono (meth) acrylate Compound obtained by ring-opening polymerization of ε-caprolactone to a monoester of the above polyhydric alcohol and acrylic acid or methacrylic acid; Vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, γ -(Meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropylmethyldiethoxysilane, γ
-Polymerizable unsaturated compounds containing an alkoxysilyl group such as (meth) acryloyloxypropyltriethoxysilane, β- (meth) acryloyloxyethyltrimethoxysilane, and γ- (meth) acryloyloxybutylphenyldimethoxysilane; acrylonitrile, methacryloyl Examples thereof include nitrile, tricyclodecanyl (meth) acrylate, isobornyl (meth) acrylate, vinyl acetate, veoba monomer (manufactured by Shell Chemical Co., Ltd.), styrene, vinyltoluene, and α-methylstyrene.

The above epoxy group-containing compounds can be used alone or in combination of two or more. The epoxy group-containing compound is not particularly limited in the concentration of the epoxy group, but usually has an epoxy equivalent of 100 to 3.0.
It is suitably within the range of 00, preferably 100 to 1,500.

The compound containing an alkoxysilyl group which can be used as the compound (B) is a compound containing two or more alkoxysilyl groups in one molecule, for example, dimethoxydimethylsilane, dimethoxydiethylsilane, dimethoxydiphenylsilane, dimethoxydiphenylsilane, Has a polymerizable unsaturated group such as ethoxydimethylsilane, trimethoxymethylsilane, trimethoxyethylsilane, trimethoxypropylsilane, trimethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane, etc. No alkoxylan; vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- ( (Meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropylmethyldiethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, β-
(Meth) acryloyloxyethyltrimethoxysilane, γ- (meth) acryloyloxybutylphenyldimethoxysilane and other polymerizable unsaturated group-containing alkoxysilanes; the above-mentioned alkoxylanes having no polymerizable unsaturated group and / or polymerizable Partial condensate of an unsaturated group-containing alkoxysilane; a copolymer of the above-mentioned polymerizable unsaturated group-containing alkoxysilane and a polymerizable unsaturated monomer copolymerizable with the alkoxysilane, and the like.

The polymerizable unsaturated monomer copolymerizable with the alkoxysilane, which is a monomer component of the copolymer, includes an epoxy group-containing polymerizable unsaturated monomer when the epoxy group-containing compound is a copolymer. And monomers other than the alkoxysilyl group-containing polymerizable unsaturated compound that can be used as the “other polymerizable unsaturated monomer” copolymerized with the monomer.

Examples of the compound having two or more carboxylic anhydride groups (hereinafter sometimes abbreviated as “polyanhydride”) usable as compound (B) include, for example, pyromellitic anhydride, ethylene glycol Condensate of 1 mol and 2 mol of trimellitic anhydride [ethylene bis (anhydrotrimellitate)], Condensate of 1 mol of glycerin and 3 mol of trimellitic anhydride [glycerin tris (anhydrotrimellitate)] Etc .; succinic acid, adipic acid, azelaic acid, sebacic acid, dodecane diacid, dimer acid,
Linear or cyclic polyanhydrides obtained by intermolecular condensation of polybasic acids such as ethyl-octadecandioic acid, phenyl-hexadecandioic acid, and 1,4-cyclohexanedicarboxylic acid; maleic anhydride, tetrahydrophthalic anhydride, etc. And a polymer containing the polymerizable unsaturated acid anhydride as one monomer component. Examples of monomers other than the polymerizable unsaturated acid anhydride that can form the polymer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and isopropyl (meth) acrylate. , N-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate,
Stearyl (meth) C _{1 ~ 24} alkyl acrylates such as (meth) acrylate; acrylonitrile, methacrylonitrile, tricyclodecanyl (meth) acrylate,
Examples include isobornyl (meth) acrylate, vinyl acetate, veoba monomer (manufactured by Shell Chemical Co., Ltd.), styrene, vinyltoluene, α-methylstyrene, and the like.

The concentration of the acid anhydride groups of the above-mentioned polyanhydrides is not particularly limited, but usually the total acid value based on the acid anhydride groups is 50 to 1,100 mgKOH / g, preferably 80 to 800 mgKOH / g. Preferably, it is within the range. Each of the above compounds [B] can be used alone or in combination of two or more.

Matting agent [C] : The matting agent, which is the component [C] in the composition of the present invention, is blended in order to reduce the gloss of the resulting coating film. Any of inorganic matting agents may be used, and these may be used alone or in combination of two or more.

Examples of the organic matting agent include fine organic resin particles that are not completely melted by baking during the formation of a coating film. The average particle diameter of the organic resin fine particles is usually in the range of 3 to 80 μm, preferably 5 to 60 μm, from the viewpoint of the appearance of the coating film and the workability of coating. As the resin type of the organic matting agent, for example, a fluorine resin such as polyvinylidene fluoride or polytetrafluoroethylene, a polyamide, an acrylic resin, a polyurethane, a phenol resin, a silicone resin, a polypropylene,
And polyamides such as nylon 11 and nylon 12.

Examples of the inorganic matting agent include silica, mica, alumina, talc, clay, calcium carbonate, barium sulfate and the like.

The top coat used in the method of the present invention includes the polyorthoester [A] and the compound [B].
And the above-mentioned matting agent [C] as an essential component, and if necessary, the following hydroxyl-containing polymer [D].

Hydroxyl-containing polymer [D] The hydroxyl-containing polymer [D] is a polymer having a hydroxyl group capable of reacting with the compound [B]. The hydroxyl group-containing polymer [C] is not particularly limited as long as it has a hydroxyl group and can be cured by reacting with the compound [B].

Representative examples of the hydroxyl group-containing polymer [C] include, for example, a hydroxyl value in the range of 10 to 250 mgKOH / g, preferably 20 to 200 mgKOH / g, and a number average molecular weight of 1,000 to 30, 000, preferably in the range of 1,500 to 25,000. Typical examples of the resin type of the hydroxyl group-containing polymer [C] include an acrylic resin, a polyester resin, a silicone polyester resin, a silicone acrylic resin, a fluororesin, and an epoxy resin. Among them, acrylic resin and polyester resin can be preferably used.

In the top coat used in the method of the present invention, the polyorthoester [A] and the compound [B]
And the matting agent [C] and the hydroxyl-containing polymer [D]
Is not particularly limited,
Usually, based on 100 parts by weight of the total solid content of the components [A], [B] and [D], it is usually appropriate that the solid content of each component is within the following range. [A] component: 1 to 95 parts by weight, preferably 25 to 90 parts by weight, [B] component: 5 to 40 parts by weight, preferably 10 to 30 parts by weight, [C] component: 1 to 40 parts by weight, preferably Is 5 to 20 parts by weight, [D] component: 0 to 89 parts by weight, preferably 0 to 65 parts by weight.

The matte coating composition of the present invention comprises the above components [A], [B], [C] and, if necessary, component [D]. Organic solvents, curing catalysts, pigments; UV absorbers, coating surface conditioners,
An antioxidant, a fluidity-controlling agent, a wax and the like can be appropriately contained.

The acid catalyst is a catalyst for promoting a reaction of deblocking an orthoester group to regenerate a hydroxyl group, and is not particularly limited.
Sulfuric acid, nitric acid; methanesulfonic acid, ethanesulfonic acid, paratoluenesulfonic acid, dodecylbenzenesulfonic acid,
Sulfonic acid compounds such as dinonylnaphthalenesulfonic acid and dinonylnaphthalenedisulfonic acid; neutralized products of the above sulfonic acid compounds with bases such as amines; the above sulfonic acid compound and n-propanol, n-butanol, n-hexanol, n -Octanol, isopropanol, 2
-Butanol, 2-hexanol, 2-octanol,
No. 1 such as cyclohexanol and tert-butanol
Esterified products with primary, secondary or tertiary alcohols;
Β-hydroxyalkylsulfonic acid esters obtained by reacting the above sulfonic acid compound with an oxirane group-containing compound such as glycidyl acetate or butyl glycidyl ether; formic acid, acetic acid, propionic acid, butyric acid, 2-ethylhexanoic acid, octanoic acid Carboxylic acids such as monobutyl phosphate, dibutyl phosphate, monoisopropyl phosphate,
Diisopropyl phosphate, monooctyl phosphate, dioctyl phosphate, monodecyl phosphate, didecyl phosphate, metaphosphoric acid, orthophosphoric acid, pyrophosphoric acid, trimethyl phosphate,
Organic phosphoric acid compounds such as triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, tris-chloroethyl phosphate, triphenyl phosphate, tricresyl phosphate; Cyracure UVI-6970, UVI-6974; Same UVI
-6990 (all, manufactured by Union Carbide, USA), Irgacure 261 and 264 (all, manufactured by Ciba Specialty Chemicals), CIT-16
82 (manufactured by Nippon Soda Co., Ltd.), BBI-102 (manufactured by Midori Kagaku), Adeka Optomer SP-150, SP-17
And a photo-latent acid generator that generates an acid upon irradiation with ultraviolet light such as 0 (both manufactured by Asahi Denka Co., Ltd.); and a Lewis acid.

The top coat used in the method of the present invention is usually a solvent-free or organic solvent type composition. When the organic solvent type composition is used, the organic solvent is prepared by dissolving each component of the top coat. Or a dispersible one, for example, hydrocarbon solvents such as heptane, toluene, xylene, octane and mineral spirit; ethyl acetate, n-acetic acid
Ester solvents such as -butyl, isobutyl acetate, ethylene glycol monomethyl ether acetate and diethylene glycol monobutyl ether acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and cyclohexanone; methanol, ethanol, isopropanol, n-butanol,
alcohol-based solvents such as sec-butanol and isobutanol; ether-based solvents such as n-butyl ether, dioxane, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether; swazol 310, swazol 1000, swazol 1500 (all manufactured by Cosmo Oil Co., Ltd.) ) And SHELLSOL A (Shellsol A, manufactured by Shell Chemical Co., Ltd.). These organic solvents can be used alone or in combination of two or more.

The above curing catalyst optionally blended is
For promoting the curing reaction of the composition of the present invention, for example, when the compound [B] is a blocked polyisocyanate compound, curing for promoting the dissociation of the blocking agent of the blocked polyisocyanate compound as a curing agent Catalysts are preferred, and suitable curing catalysts include, for example, tin octylate, dibutyltin di (2-ethylhexanoate),
Organic metal catalysts such as dioctyltin di (2-ethylhexanoate), dioctyltin diacetate, dibutyltin dilaurate, dibutyltin oxide, dioctyltin oxide, and lead 2-ethylhexanoate can be mentioned.

When the compound [B] is an amino resin such as a melamine resin, particularly when it is a low molecular weight melamine resin of methyl etherification or a mixed etherification of methyl ether and butyl ether, phosphoric acid is used as a curing catalyst. A sulfonic acid compound or an amine neutralized sulfonic acid compound is preferably used. Representative examples of the sulfonic acid compound include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, and dinonylnaphthalenedisulfonic acid. As the amine in the amine neutralized product of the sulfonic acid compound,
Any of primary amine, secondary amine and tertiary amine may be used.

When the compound [B] is an epoxy group-containing compound, examples of the curing catalyst include tetrakis (acetylacetonato) zirconium, cobalt acetylacetonato, tris (acetylacetonato) aluminum,
Chelating compounds such as manganese acetylacetonate; β
-Compound having hydroxyamino structure and lead (II) oxide
Metal carboxylate such as lead 2-ethylhexanoate, lead secanoic, lead naphthenate, lead octylate, lead acetate, lead lactate, zirconium octylate; imidazole, 2-methylimidazole, 2-isopropylimidazole , 2-undecylimidazole,
And imidazole compounds such as 2-phenylimidazole.

When the compound [B] is an alkoxysilyl group-containing compound, examples of the curing catalyst include organic sulfonic acid compounds such as dodecylbenzenesulfonic acid, paratoluenesulfonic acid, dinonylnaphthalenesulfonic acid, and trifluorosulfonic acid. Amine neutralized products of these organic sulfonic acid compounds; monobutyl phosphate, dibutyl phosphate, monoisopropyl phosphate, diisopropyl phosphate,
Monooctyl phosphate, dioctyl phosphate, monodecyl phosphate, didecyl phosphate, metaphosphoric acid, orthophosphoric acid, pyrophosphoric acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, tris Phosphoric compounds such as chloroethyl phosphate, triphenyl phosphate and tricresyl phosphate can be exemplified.

When the compound [B] is a polyacid anhydride, examples of the curing catalyst include tetraethylammonium bromide, tetrabutylammonium bromide, tetraethylammonium chloride, tetrabutylammonium fluoride, tetrabutylphosphonium bromide, and tributylammonium chloride. Examples include quaternary salt catalysts such as phenylbenzylphosphonium chloride; amines such as triethylamine and tributylamine.

In the method of the present invention, pigments which are optionally added to the top coat include inorganic color pigments such as titanium white, carbon black, red iron oxide and titanium yellow; quinacridone red, azo red, phthalocyanine blue, and the like.
Organic coloring pigments such as phthalocyanine green and organic yellow pigments; coloring pigments such as glittering pigments such as aluminum powder and glittering mica powder: extender pigments such as silica powder, calcium carbonate, barium sulfate, mica, clay and talc; calcium ions Examples include rust preventive pigments such as exchanged silica, phosphate rust preventive pigments, and chromate pigments.

Production of a coated metal plate : In the method of the present invention, a coated metal plate is produced by applying and baking the above-mentioned top coat on a cured primer coating film formed on the long metal plate. I do.

The above top coat is applied by a known coating method such as a roll coating method, a spray coating method, a brush coating method, an electrostatic coating method, an immersion method, an electrodeposition coating method, a curtain coating method and a roller coating method. By drying, the coated metal sheet of the present invention can be obtained. Among the above coating methods, a roll coating method and a curtain coating method can be suitably used. The thickness of the top coat is not particularly limited, but is usually 5 to 30 μm, preferably 10 to 22 μm.
The range of μm is preferred. The drying of the coating film may be appropriately set according to the type of the resin to be used and the like, but when continuously coated by a coil coating method or the like, the maximum material arrival temperature is usually 160 to 25.
0 ° C., preferably 15-150 ° C. under the condition of 180-230 ° C.
Bake for 60 seconds. When baking in batch mode,
For example, baking can be performed at an ambient temperature of 80 to 140 ° C. for 10 to 30 minutes.

The coated metal sheet of the present invention, on which the above-mentioned overcoat film is formed, can exhibit excellent film performance such as excellent film appearance, adhesion and solvent resistance.

The coated metal sheet of the present invention can be suitably used, for example, for building materials such as house roofs, walls, shutters, and garages; home appliances, automobiles, steel furniture, kitchen appliances, and the like.

[0085]

The present invention will be described more specifically with reference to the following examples.

Hereinafter, "parts" and "%" are based on weight.

Synthesis of Polyester Synthesis Example 1 31 parts of ethylene glycol, 27 parts of 1,3-butanediol, 19.4 parts of trimellitic anhydride, 49 parts of isophthalic acid were placed in a reaction vessel equipped with a stirrer, a rectification tower and a thermometer. .8
Parts, 29.5 parts of terephthalic acid and 0.2 parts of dibutyltin dioxide, and the esterification reaction was carried out while blowing the inert gas so that the rectification column temperature did not exceed 110 ° C. When 2/3 was distilled, it was cooled once. Then, after adding 33.2 parts of isophthalic acid and 36.9 parts of terephthalic acid, the temperature was raised to 250 ° C. and an esterification reaction was performed to obtain a polyester a. Polyester a had a hydroxyl value of 141 mgKOH / g and a number average molecular weight of 1,600.

Synthesis Examples 2 to 4 Synthesis was performed in the same manner as in Synthesis Example 1 except that the composition was changed as shown in Table 1 below to obtain each polyester. The hydroxyl value and number average molecular weight of each of the obtained polyesters are shown in Table 1 below.

[0089]

[Table 1]

[0090] Preparation Example polyorthoesters 1 stirrer, condenser, reactor having a temperature control device and a solvent recovery apparatus, 424 parts of methyl orthoformate, 2-butyl-2-ethyl-1,3-propane 640 parts of a diol, 136 parts of pentaerythritol and 4 parts of a 90% formic acid aqueous solution were charged, and the mixture was maintained at about 85 ° C. for 1 hour while distilling off methanol produced by the alcohol exchange reaction. afterwards,
The temperature was raised to 190 ° C. over 2 hours to recover 365 parts of methanol, and the colorless and transparent liquid polyorthoester (A
-1) was obtained. The resulting polyorthoester had a Gardner viscosity X ⁺ and a weight average molecular weight of 1,540.

Production Examples 2 to 5 Reactions were carried out in the same manner as in Production Example 1 except that the raw material compositions to be blended were as shown in Table 2 below, and polyorthoesters were obtained.

[0092]

[Table 2]

Preparation of matte paint Example 1 30 parts of polyorthoester (A-1) obtained in Production Example 1,
“Beccolite M-6301-45” (manufactured by Dainippon Ink and Chemicals, Inc., an oil-free polyester solution having a solid content of about 45%, a resin having a number average molecular weight of about 5,000, and a resin having a hydroxyl value of about 45 mgKOH / g) 122.2 parts (55 parts by solid content), 15 parts of "CYMER 303" (Methyl Etherified Melamine Resin, manufactured by Mitsui Cytec Co., Ltd.)
"Catalyst 600" (Mitsui Cytec Co., Ltd., 7
1.0 part of 0% aromatic sulfonic acid solution (active ingredient amount 0.7
Parts) and 100 parts of titanium white, and a mixed solvent [Swazol 1500 (Note 1) / cyclohexanone / 3-methoxybutyl acetate = 50/25/25] was added, mixed and dispersed, and then “Syloid 308” ( Gra
ce Davison [Grace Davison], 15 parts of amorphous silica powder, average particle size of about 7 μm) and the above-mentioned mixed solvent were added and mixed uniformly, and the viscosity was about 100 seconds (Ford cup # 4/25 ° C .; the same applies hereinafter). ) Was obtained. (Note 1) Swazol 1500: a high-boiling aromatic hydrocarbon solvent manufactured by Cosmo Oil Co., Ltd.

Examples 2 to 11 and Comparative Examples 1 to 5 In the same manner as in Example 1, except that the composition was changed as shown in Table 3 below, each overcoat having a viscosity of about 100 seconds was obtained. Was. The blending amounts in Table 3 are indicated by the solid content or the amount of the active ingredient excluding the solvent. The top coats obtained in Preparation Examples 8 to 10 are for Comparative Examples.

In Table 3 below, (note) has the following meanings, respectively. (* 1) Desmodur BL3175: a solution of hexamethylene diisocyanate isocyanurate, manufactured by Sumitomo Bayer Urethane Co., having a solid content of about 75%. (* 2) Nail cure 5225: manufactured by King Industries, USA, amine neutralized solution of dodecylbenzenesulfonic acid, the active ingredient content is 25%. (* 3) Takenate TK-1: manufactured by Takeda Pharmaceutical Co., Ltd.
Organotin curing catalyst, solid content 10%. (* 4) Love Color 030 (F) Clear: Acrylic copolymer particles, manufactured by Dainichi Seika Co., Ltd., average particle size of about 20 μm
m. (* 5) Tospearl 3120: Toshiba Silicone Co., Ltd.
Made, silicone resin fine particles, average particle size about 20 μm. (* 6) VESTOSINT 2158: “Vestsint 2158”, manufactured by Daicel Huls, nylon powder, average particle size about 20 μm. (* 7) Techpolymer MBX-15: Sekisui Chemical Co., Ltd.
Methyl methacrylate polymer particles, average particle size about 15
μm.

The matte paints obtained in Examples 1 to 11 and Comparative Examples 1 to 5 were subjected to the following pot life tests. The test results are shown in Table 3 below.

Pot life: 30 coats of each top coat whose viscosity was adjusted to about 100 seconds (Ford cup # 4/25 ° C.)
The sample was stored in a room at 30 ° C. for 30 days, and evaluated based on the following criteria from the change rate (%) of the viscosity after storage to the viscosity before storage. ：: The rate of change is 20% or less, Δ: The rate of change exceeds 20% and 50% or less, ×: The rate of change exceeds 50%.

[0098]

[Table 3]

[0099]

[Table 4]

Production Example 12 of Painted Metal Plate A hot-dip galvanized steel plate having a thickness of 0.35 mm was coated on an epoxy resin-based primer paint “K” manufactured by Kansai Paint Co., Ltd.
P Color 8416 Primer "is applied so that the dry film thickness is about 5 μm, and the material reaching temperature (PMT) is 200 ° C.
It was baked for 30 seconds under the following conditions. Then, after cooling, the top coat obtained in Preparation Example 1 was applied on the primer coating so that the dry film thickness was about 18 μm.
(MT) was 160 ° C. for 50 seconds to obtain a coated metal plate.

Examples 13 to 27 and Comparative Examples 6 to 15 The same procedures as in Example 12 were carried out except that the materials used, the type of matte paint and the baking conditions were as shown in Table 4 below. A coated metal plate was obtained.

In Table 4 below, the abbreviations for each material type have the following meanings.

5% AL-Zn: 0.35 mm thick aluminum-zinc alloy plated steel sheet having an aluminum content of about 5% 55% AL-Zn: 0.35 mm thick aluminum having an aluminum content of about 55% Zinc alloy plated steel sheet, AL plated steel sheet: 0.5 mm thick aluminum plated steel sheet, AL board: 0.5 mm thick aluminum plate.

Examples 12 to 27 and Comparative Examples 6 to 15
Various tests were performed on each of the coated metal plates obtained in the above, based on the following test methods. The test results are shown in Table 4 below.

Test Method Appearance of painted surface: The appearance of the painted surface (30 cm × 30 cm) was visually observed. The coated surface was free from any abnormalities such as cissing and dents and showed a good matte coating appearance.

Gloss: JIS K-5400 7.6 (1
990), the 60-degree specular reflectance was measured according to the prescribed 60-degree specular gloss.

Pencil hardness: JIS
A pencil scratch test specified in K-5400 8.4.2 (1990) was performed, and evaluation by scratches was performed.

Adhesion: JIS K-5400 8.5.
2 (1990) According to the crosscut-tape method, 11 parallel vertical and horizontal straight lines are drawn at 1 mm intervals on the surface of the coating film of the test plate so as to reach the substrate with a cutter knife, and the distance is 1 mm. 100 × 1 mm squares were created. A cellophane adhesive tape was adhered to the surface, and the degree of peeling of the squares when the tape was abruptly peeled was observed and evaluated according to the following criteria. ：: No peeling of the coating film was observed at all. Δ: The coating film was peeled, but 60 or more squares remained. ×: The coating film was considerably peeled, and the number of remaining squares was less than 60.

Impact resistance: JIS K-5400
According to 3.2 (1990) Dupont impact resistance test,
An impact was applied to the painted surface of the coated plate under the conditions of a drop weight of 500 g, a tip diameter of the hammer of 1/2 inch and a drop weight height of 50 cm.
Then, a cellophane adhesive tape was adhered to the portion where the impact was applied, and the degree of peeling of the coating film when the tape was instantaneously peeled was evaluated according to the following criteria. ：: No peeling was observed on the coated surface. ：: Slight peeling was observed on the coated surface. X: Considerable peeling was observed on the coated surface.

Solvent resistance: Approximately 4 kg / g on the coated surface with gauze impregnated with methyl ethyl ketone in a room at 20 ° C.
It was reciprocated between approximately 5 cm lengths with a load of cm ² . Evaluation was made based on the following criteria by the number of reciprocations until the primer-coating film was seen. ：: The number of reciprocations is 50 or more △: The number of reciprocations is 30 or more and less than 50 times ×: The number of reciprocations is less than 30 times.

Corrosion resistance: Each coated plate was cut into a size of 70 × 150 mm, and the back surface and the cut surface were sealed with a rust preventive paint. A cross-cut reaching the base was placed almost at the center of the sealed painted plate and subjected to a salt spray test. The salt spray test was performed according to JIS Z-2371, and the salt spray test time was set to 500 hours, and the average blister width of the cross cut portion was visually evaluated according to the following criteria. ：: No blisters are observed in the cross cut portion. ○: Average blister width on one side from the cut is less than 1 mm. Δ: Average blister width on one side from the cut is 1 mm or more and less than 5 mm. The average blister width on one side from is 5 mm or more.

[0112]

[Table 5]

[0113]

[Table 6]

[0114]

[Table 7]

[0115]

The matte paint of the present invention has good storage stability, can form a good coating film, and can lower the baking temperature, so that energy saving in a coating line can be achieved. It is possible to obtain a matte steel plate having a stable gloss. In addition, since it is not necessary to add alcohol to improve the storage stability of the top coat, it is possible to eliminate the problem of reduced resistance to baking when a paint film is baked.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 161/20 C09D 161/20 163/00 163/00 173/02 173/02 175/04 175/04 183 / 10 183/10 (72) Inventor Hirohiko Aida 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa F Kansai Paint Co., Ltd. F-term (reference) 4D075 BB73X CA13 CA33 CA44 CB02 DA03 DB01 DC01 DC10 DC11 DC18 DC38 EA07 EB20 EB22 EB32. HA216 HA286 HA376 HA446 HA526 HA536 HA546 JA74 JA75 JC32 KA03 KA07 MA14

Claims (9)

[Claims] [A] (a) (a) The following formula (1) In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and three R ^{2 s} are the same or different and each represent an alkyl group having 1 to 4 carbon atoms. (B) reacting at least one glycol compound selected from α-glycol and β-glycol, and (c) a hydroxyl group-containing compound other than (b) having at least two hydroxyl groups in one molecule. A matte coating composition comprising: a polyorthoester, [B] a compound having at least two groups reactive with a hydroxyl group in one molecule, and [C] a matting agent. 2. The coating composition according to claim 1, wherein the orthoester (a) is at least one compound selected from methyl orthoformate, ethyl orthoformate, methyl orthoacetate and ethyl orthoacetate. . 3. The compound (c) having a molecular weight of 90
~ 3,000, and the hydroxyl value is 60 ~
The coating composition according to claim 1, wherein the coating composition is in the range of 1,850 mgKOH / g. 4. The method according to claim 1, wherein the hydroxyl group in the hydroxyl group-containing compound (c) is
The paint according to any one of claims 1 to 3, wherein the paint is blocked by a 5- or 6-membered orthoester composed of an orthoester (a) and a glycol compound (b). Composition. 5. The method according to claim 1, wherein the curing agent [B] is at least one compound selected from a polyisocyanate compound, an amino resin, an epoxy group-containing compound and a polyacid compound. Paint composition. 6. A hydroxyl group-containing polymer [D] having a hydroxyl value in the range of 10 to 250 mg KOH / g and a number average molecular weight in the range of 1,000 to 30,000. Item 6. The coating composition according to any one of Items 1 to 5. 7. The coating composition according to claim 6, wherein the hydroxyl group-containing polymer [D] is at least one polymer selected from a polyester resin, a silicone polyester resin and an acrylic resin. 8. A polyorthoester [A], a curing agent [B], a matting agent [C], and a hydroxyl group-containing polymer [D].
The compounding ratio of (A), based on 100 parts by weight of the total solid content of (B) and (D) component, component (A) 1 to 95 parts by weight, (B) component 5 to 40 parts by weight, [C] Component is 1-4
The coating composition according to any one of claims 1 to 7, wherein 0 parts by weight and [D] component are within a range of 0 to 89 parts by weight. 9. The curing of the coating composition according to any one of claims 1 to 8, with or without a primer coating on a metal plate whose surface may be subjected to a chemical conversion treatment. A coated metal plate characterized by having a coating film formed thereon.