JP2002069362A - Composition for aqueous coating and aqueous coating liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous coating composition excellent in durability, scratch resistance and stainproofness, and capable of imparting coating film having a ground glass-like tone. SOLUTION: The composition is obtained by compounding (A) 100 pts.mass of an acrylic copolymer having an acid value of 20-200 mg KOH/g and a weight- average molecular weight of 4,000-200,000 with (B) 30-80 pts.mass of a melamine compound and/or an epoxy compound, (C) 3-200 pts.mass of a hydrophilic solvent, (D) ammonia and/or an amine compound corresponding to 0.5-1.1 equivalents of the carboxy group contained in the acrylic copolymer and (E) 30-500 pts.mass of particles having an average particle size of 1-50 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel aqueous coating composition. More specifically, the present invention relates to a novel aqueous coating composition exhibiting excellent properties, such as durability, scratch resistance, excellent stain resistance, and imparting a frosted glass-like coating film. Related to coating liquid.

[0002]

2. Description of the Related Art It has been known for a long time to apply a frosted glass-like surface treatment to a transparent glass surface. A method has been performed in which the surface is chemically etched to provide irregularities by acid treatment, or a method in which both are used in combination.

[0003]

However, in sandblasting, the mechanical strength is reduced due to scratches on the glass, and the wall thickness and weight for obtaining the required strength are increased. On the other hand, in hydrofluoric acid treatment, hydrofluoric acid is used. There are many restrictions on the handling of hydrofluoric acid, and it is necessary to treat the hydrofluoric acid waste liquid after use. An object of the present invention is to solve such a problem.

[0004]

That is, the present invention provides:
(A) 100 parts by mass of an acrylic copolymer having an acid value of 20 to 200 mgKOH / g and a weight average molecular weight of 4,000 to 200,000, and (B) a melamine compound and / or an epoxy compound 30 to 100 parts by mass. 80 parts by mass,
(C) 3 to 200 parts by mass of a hydrophilic solvent, (D) 0.5 to 200 parts by mass of a carboxyl group contained in the acrylic copolymer.
Ammonia and / or amine compound corresponding to 1.1 equivalents, and (E) particles having an average particle size of 1 to 50 μm 30
The present invention relates to a composition for aqueous coating, which comprises from about 500 parts by mass. The present invention also relates to an aqueous coating composition further containing an ultraviolet absorbing compound in the aqueous coating composition. Further, the present invention relates to an aqueous coating liquid obtained by mixing water with the aqueous coating composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The acrylic copolymer used in the present invention has an acid value of 20 to 200 mgKOH / g, preferably 30 to 1 mgKOH / g.
50 mg KOH / g, more preferably 40 to 100 mg
It is in the range of KOH / g. When the acid value is less than 20 mgKOH / g, the solubility of the copolymer in a water-containing solvent is reduced,
If it exceeds 200 mgKOH / g, the water resistance of the resulting coating film will decrease. Here, the acid value means the number of milligrams of potassium hydroxide required to neutralize 1 gram of the acrylic copolymer.

The acrylic copolymer used in the present invention is:
Its weight average molecular weight is in the range of 4,000 to 200,000, and the upper limit is preferably 10
0000, more preferably 60,000, particularly preferably 50,000, even more preferably 30,000
And the lower limit is preferably 6,000.
0, more preferably 8,000. When the weight average molecular weight is less than 4,000, the hardness and durability of the obtained coating film are reduced. When the weight average molecular weight of the copolymer exceeds 200,000, the viscosity of the composition may be excessively increased and the coating film may become brittle. In the present invention, the weight average molecular weight is determined by GPC using styrene as a standard.
Was calculated using.

In the present invention, the acrylic copolymer is a monomer having an acid group (for example, a carboxyl group) (hereinafter, referred to as a monomer having an acid group).
It is called monomer (1). ) Is copolymerized with one or more other monomers copolymerizable with the monomer (1) (hereinafter, referred to as monomer (2)). Can be obtained by: As the monomer (1),
Monocarboxylic acids such as acrylic acid and methacrylic acid; dicarboxylic acids such as maleic acid, maleic anhydride and itaconic acid; and monoesters of these dicarboxylic acids. Of these, acrylic acid and methacrylic acid are most preferred as monomer (1).

Examples of the monomer (2) include alkyl esters of acrylic acid, aralkyl esters of acrylic acid, alkyl esters of methacrylic acid, aralkyl esters of methacrylic acid, amide derivatives of acrylic acid, and amide derivatives of methacrylic acid. No. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate,
t-butyl (meth) acrylate, 2-hexyl (meth) acrylate, stearyl (meth) acrylate,
Cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth)
Acrylate, 1,4-butanediol mono (meth) acrylate, dimethylaminoethyl (meth) acrylate, acrylamide, N-hydroxymethylacrylamide, N-butoxymethylacrylamide, N, N-dimethylacrylamide, methacrylamide, and the like. it can. In this specification, the term acrylic copolymer means a copolymer of monomer (1) and monomer (2), and the designation (meth) acrylate refers to acrylate and methacrylate, respectively. means.

In addition, styrene, α-methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, acrylamide, methacrylamide, methylolacrylamide,
Butoxymethylacrylamide, methylol methacrylamide and the like can also be used as the monomer (2).

As the monomer (2), each of the above-mentioned monomers can be used. Generally, an acrylic monomer and a methacrylic monomer are used in combination, and the monomer (1) is an acrylic monomer. When an acid or methacrylic acid is used, the monomer (2)
The mass ratio of the acrylic monomer to the methacrylic monomer is usually 1: 0.1 to 1: 5, preferably 1: 0.5 to
It is preferable to set the ratio to 1: 3.

Also, at least 50% by mass of the monomer used, preferably at least 60% by mass, more preferably at least 70% by mass.
Above, the total of acrylic acid, methacrylic acid, alkyl ester of acrylic acid, aralkyl ester of acrylic acid, alkyl ester of methacrylic acid, aralkyl ester of methacrylic acid, amide derivative of acrylic acid, amide derivative of methacrylic acid may be occupied. Desirably, if the total of these contents is less than 50% by mass, it is difficult to obtain a uniform polymer, and problems tend to occur.

A preferred monomer mixture of the acrylic copolymer of the present invention is a combination of acrylic acid, N-butoxymethylacrylamide, styrene and 2-ethylhexyl acrylate, and the mass ratio of each monomer is as follows. , Acrylic acid: N-butoxymethylacrylamide: styrene: 2-ethylhexyl acrylate = 5 to 15:15
-30: 15-30: 25-40. When copolymerizing the monomer mixture, a known method such as a solution polymerization method or a suspension polymerization method can be arbitrarily adopted.As the polymerization initiator, for example, azobisisobutyronitrile,
Benzoyl peroxide and the like can be used. Also,
As the polymerization solvent, alcohols, ethers, ketones and the like can be used, but it is preferable to select a solvent having a boiling point of 240 ° C. or lower, specifically, diglyme,
Propylene glycol monoacetate, propylene glycol monoacetate monomethyl ether, methoxybutanol, methyl cellosolve, butyl cellosolve,
Examples thereof include methyl ethyl ketone and methyl isobutyl ketone. Of course, these solvents can be used as a mixture. Further, after the completion of the copolymerization reaction, the resulting acrylic copolymer may be isolated and then used as the composition of the present invention. Alternatively, a part or all of the polymerization solvent may be used without isolating the copolymer. It is also possible to provide the composition as it is. It is also possible to carry out the copolymerization in the presence of other components of the composition according to the invention.

Next, the melamine compound and / or epoxy compound (B) constituting the composition of the present invention will be described. Suitable compounds as the melamine compound used in the present invention include compounds represented by the following general formula (1) or (2).

[0014]

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[0015]

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In the general formulas (1) and (2), R ¹ to
R ¹⁶ individually represents hydrogen or an alkyl group having 1 to 4 carbon atoms, and all of R ^{1 to} R ¹⁶ are preferably alkyl groups, and the alkyl group is preferably a methyl group. It should be noted that the melamine compound represented by the general formula (2) is a dimer of the melamine compound represented by the general formula (1), and the compounds represented by the general formulas (1) and (2) are optional. Can be used in a mixture.

The epoxy compound is not particularly limited,
From the viewpoint of storage stability in the case of a coating solution, it is desirable that the epoxy equivalent is usually 500 or more, preferably 800 or more. The upper limit of the epoxy equivalent is not particularly limited, but is usually 2,000 or less, preferably 1,500 or less. . Specific examples of the epoxy compound include a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol novolak type epoxy resin, and an alicyclic epoxy resin. Any of these can be suitably used, and bisphenol A type epoxy resin and bisphenol F type epoxy resin are particularly preferable. The molecular weight of these epoxy compounds is 5,000
The following is preferred.

An epoxy compound having improved dispersibility in water by adding a reaction product of a polyoxyethylene polyol and an acid anhydride in addition to these ordinary epoxy compounds (Japanese Patent Application Laid-Open No. Hei 7-206982). ) Or an epoxy compound in which the affinity for water is improved by adding a reaction product of a phosphorus-containing polyoxyalkylene polyol and an acid anhydride (JP-A-7-304853), or an isocyanate group-containing polyether urethane Emulsifying epoxy compound obtained by reacting an epoxy compound with an alkylphenol ethylene oxide adduct (Japanese Patent Laid-Open No.
An epoxy compound having improved dispersibility in water by mixing a polyglycidyl ether of a polyalkylene polyether polyol (JP-A-6-179801) can also be used.

The mixing ratio of the melamine compound and / or the epoxy compound to the acrylic copolymer is 30 to 80 parts by mass, preferably 40 to 65 parts by mass, based on 100 parts by mass of the acrylic copolymer. It is in the range of parts by mass. If the amount is less than 30 parts by mass, the effect of the present invention may not be exhibited. If the amount exceeds 80 parts by mass, the coating film may be weakened. The amount of the epoxy compound is preferably 0.01 to 3.0 equivalents, more preferably 0.1 to 2.0 equivalents, based on the carboxyl groups contained in the acrylic copolymer. When the melamine compound and the epoxy compound are used in combination, the ratio of both is not particularly limited as long as the object of the present invention is achieved, and the ratio (mass ratio) of the melamine compound to the epoxy compound is usually more than 0: It is less than 100 to less than 100: more than 0, but preferably in the range of 20:80 to 80:20 from the viewpoint of the combined effect.

Next, the hydrophilic solvent (C) used in the present invention will be described. In the present invention, the hydrophilic solvent is a solvent that can be mixed with water at an arbitrary ratio, and is not particularly limited as long as the object of the present invention is achieved. For example, oxygen-containing organic solvents such as alcohols, ethers, and ketones such as 4-methoxybutanol, propylene glycol monomethyl ether, butyl cellosolve, ethyl cellosolve, cellosolve acetate, 2-propanol (isopropanol), diglyme, and methyl ethyl ketone are preferably used. can do. of course,
These may be used in combination of two or more. In addition,
When a hydrophilic solvent is used as the polymerization solvent when producing the acrylic copolymer, the polymerization solvent used for the polymerization can be used as it is as the hydrophilic solvent in the composition. The amount of the hydrophilic solvent to be used is preferably 3 to 200 parts by mass, more preferably 10 to 100 parts by mass, based on 100 parts by mass of the acrylic copolymer. If the amount of the hydrophilic solvent is less than 3 parts by mass, the appearance of the coating film is likely to be uneven, which is not preferable. On the other hand, if the amount exceeds 200 parts by mass, it may be difficult to defoam the coating liquid when the coating liquid is used, which is not preferable.

Next, the (D) ammonia and / or amine compound used in the present invention will be described.
The amine compound used in the present invention is not particularly limited, but it is preferable to use an amine compound having a molecular weight of 300 or less, particularly, a molecular weight of 200 or less, from the viewpoint of drying properties after forming a coating film. Specifically, hexylamine,
Aliphatic primary, secondary or tertiary amines such as diisopropylamine, triethylamine; N, N
Aromatic amines such as dimethylaniline and benzylamine; heterocyclic amines such as 2,6-lutidine can be suitably used, and N, N-dimethylmonoethanolamine containing a hydroxyl group in the molecule or having an ether bond. Ethyl-2-aminoethyl ether and the like can also be used. Further, two or more amine compounds can be used in combination. As the ammonia, ammonia gas can be used, but a normal aqueous ammonia solution can be used as it is, and the aqueous coating composition can be more easily prepared. The total amount of the ammonia and / or amine compound used in the present invention is usually 1.1 equivalent or less, preferably 0.95 equivalent or less of the carboxyl group contained in the acrylic copolymer, and the lower limit is usually 0.5 equivalent or more, preferably 0.65 equivalent or more is desirable.

Next, (E) particles having an average particle diameter of 1 to 50 μm used in the present invention will be described. The particles used in the present invention have an average particle diameter of 1 to 50 μm, preferably 30 μm, more preferably 15 μm as the upper limit, and preferably 2 μm, preferably 3 μm as the lower limit. The measurement of the average particle diameter can be performed by a distribution diagram method using a crush gauge specified in JIS K-5400.
When the average particle size is smaller than 1 μm, it is not preferable because a frosted glass tone is not exhibited, and when the average particle size is larger than 50 μm, the coating film is roughened. The bulk density (apparent specific gravity) of the particles is not particularly limited, but is usually 0.15 from the viewpoint of the strength of the coating film and the dispersibility in the coating liquid.
It is desirably about 0.70 g / cm ³ .

The material of the particles is not particularly limited, and any material can be used. For example, inorganic particles such as silica, alumina, and quartz, acryl, polyethylene, poly (propylene carbonate), polystyrene, polyurethane, and the like. Organic polymer-based particles such as a crosslinked resin may be used. In the case where a frosted coating film is used for the coating application, the refractive index (n) in the wavelength range of 400 nm to 780 nm is selected as the material of the particles from the viewpoints of frost tone development, light transmittance of the coating film, and color tone.
²⁵ _D) is usually 1.3 to 2.0, preferably 1.4 to
A value of 1.8 is desirable. The refractive index of the particles is
Performed using an Abbe refractometer (liquid: mixture of ethanol and carbon disulfide). Further, from the total light transmittance and coloring of the coating film, for the same purpose, 400 nm to 780 nm.
It is desirable that the extinction coefficient is usually 0.1 / μm or less, preferably 0.05 / μm or less in the above wavelength range. The shape of the particles is not particularly limited, and may be any of irregular, oblong, and spherical, but is preferably spherical.

The amount of the particles used in the present invention is 10 to 30 parts by weight based on 100 parts by mass of the acrylic copolymer.
It is 0 parts by mass, and the upper limit is preferably 200 parts by mass, more preferably 150 parts by mass, and the lower limit is preferably 20 parts by mass, more preferably 30 parts by mass. If the amount of the particles is less than 10 parts by mass, a sufficient haze effect may not be exhibited as a coating film, and if the amount of the particles exceeds 300 parts by mass, sufficient strength as a coating film cannot be obtained. In some cases, this is not preferable.

The aqueous coating composition of the present invention includes:
Optional components can be added as needed. Such optional components include, for example, ultraviolet absorbing compounds. The ultraviolet absorbing compound is not particularly limited, but an organic ultraviolet absorbing material is preferable, for example,
Examples include benzotriazole-based compounds, benzophenone-based compounds, triazine-based compounds, salicylate-based compounds, cyanoacrylate-based compounds, and oxalic anilide-based compounds. Among these, benzotriazole-based compounds and benzophenone-based compounds can be particularly preferably used.

As the benzotriazole compound, for example, a compound represented by the following general formula (3) is preferably exemplified.

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In the formula, R ¹⁷ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 10, preferably 1 to 6, carbon atoms. Examples of the halogen atom include fluorine, chlorine, bromine and iodine, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a t-butyl group and a cyclohexyl group. And a chlorine atom are preferred. The substitution position of R ¹⁷ is the 4-position or 5-position of the benzotriazole skeleton, but in the case of a halogen atom and an alkyl group, it is usually located at the 5-position. R
¹⁸ is a hydrogen atom or a carbon number of 1 to 10, preferably 1 to
6 represents a hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a t-butyl group, a t-amyl group, a cyclohexyl group,
Examples thereof include a 1,1-dimethylbenzyl group, and particularly preferred are a t-butyl group, a t-amyl group, and a 1,1-dimethylbenzyl group. R ¹⁹ has 2 to 10 carbon atoms, preferably 2 carbon atoms.
An alkyl group having 4 to 4, an arylalkyl group having 7 to 15, preferably 7 to 10 carbon atoms, or an alkoxycarbonylalkyl group represented by the following general formula. ^{-R 23 -COO-R 24 (R} 23 is a divalent saturated hydrocarbon group having 1 to 4 carbon atoms (typically, methylene group, ethylene group, trimethylene group, alkylene groups such as tetramethylene group, etc.), R ²⁴ is a hydrogen atom or a saturated hydrocarbon group having 1 to 18 carbon atoms (typically,
Methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, amyl, t-amyl, neoamyl, 2-methylbutyl, cyclohexyl, hexyl, Neohexyl group, heptyl group, octyl group, ethylhexyl group,
An alkyl group such as a decyl group, a dodecyl group, a t-dodecyl group, a hexadecanyl group, an octadecanyl group, etc.) As the alkyl group for R ¹⁹ , a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a t- Butyl group, t
-Amyl group, cyclohexyl group, octyl group, 2-ethylhexyl group, decyl group, and the like. Examples of the arylalkyl group include 1,1-dimethylbenzyl group, 2-phenylethyl group, benzyl group, β-naphthylethyl group and the like can be exemplified. Examples of the alkoxycarbonylalkyl group include a 2- (octyloxycarbonyl) ethyl group, a 2- (2-ethylhexyloxycarbonyl) ethyl group, a 2- (methoxycarbonyl) ethyl group, and a 4- (butoxycarbonyl) butyl group. Etc. can be exemplified as preferable ones.

Specific examples of such a benzotriazole compound include 3- (5-chloro-2H-benzotriazol-2-yl) -5- (1,1-dimethylethyl) -4-hydroxy-benzenepropane. Acid, 3- (2
H-benzotriazol-2-yl) -5- (1,1-
Dimethylethyl) -4-hydroxy-benzeneethanic acid, 3- (2H-benzotriazol-2-yl) -4
-Hydroxybenzene ethane acid, 3- (5-methyl-2
H-benzotriazol-2-yl) -5- (1-methylethyl) -4-hydroxybenzenepropanoic acid, iso-octyl-3- (3- (2H-benzotriazole-
2-yl) -5-tert-butyl-4-hydroxyphenylpropionate, methyl-3- [3-tert-butyl-5-
(2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate, 2- (5'-methyl-
2′-hydroxyphenyl) benzotriazole, 2-
[2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (2′-hydroxy-5′-t-butylphenyl) benzotriazole, 2- (3 ′, 5′-di-t-
Butyl-2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, 2- (3'-dodecyl-
5'-methyl-2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-
t-amyl-phenyl) -2H-benzotriazole,
2- (2′-hydroxy-3 ′-(3 ″, 4 ″,
5 ″, 6 ″ -tetrahydrophthalimidomethyl)-
5-methylphenyl) benzotriazole, 2- (3 ′
-T-butyl-5'-methyl-2'-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3 ',
5'-di-t-butyl-2'-hydroxyphenyl)-
5-chlorobenzotriazole, 2- [2-hydroxy-3,5-di (1,1-dimethylbenzyl) phenyl]
-2H-benzotriazole, 2- [2-hydroxy-
3-dimethylbenzyl-5- (1,1,3,3-tetramethylbutyl) phenyl] -2H-benzotriazole, 3- (5-chloro-2H-benzotriazole-2
-Yl) -5-tert-butyl-4-hydroxyphenylpropanoic acid octyl ester, 3- (5-chloro-2H-
Benzotriazol-2-yl) -5-t-butyl-4
-Hydroxyphenyl-n-propanol; among these, octyl 3- (5-chloro-2H-benzotriazol-2-yl) -5-t-butyl-4-hydroxyphenylpropanoate, 3- ( 5-
Chloro-2H-benzotriazol-2-yl) -5
t-Butyl-4-hydroxyphenyl-n-propanol is particularly preferably used.

Examples of the benzophenone compound include compounds represented by the following general formulas (4) to (7).

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In the formula, R ²⁰ is a covalent bond, hydrogen, and has 1 to 1 carbon atoms.
10, preferably 1 to 3 alkylene groups or alkylidene groups. Examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, and a propylene group. Examples of the alkylidene group include an ethylidene group and a propylidene group. When R ²⁰ is hydrogen, -R ²⁰ -CO
It means that the OH group is -H. R ²¹ and R
²² is the same or different and represents a hydroxyl group, an alkyl group or an alkoxy group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a t-butyl group, and a cyclohexyl group.Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group.
Examples thereof include an i-propoxy group and a butoxy group. Also,
m and n each represent an integer in the range of 0 ≦ m ≦ 3 and 0 ≦ n ≦ 3.

Specific examples of the benzophenone compound include 2-hydroxy-4-methoxybenzophenone-5
-Carboxylic acid, 2,2'-dihydroxy-4-methoxybenzophenone-5-carboxylic acid, 4- (2-hydroxybenzoyl) -3-hydroxybenzenepropanoic acid,
2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-
Methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2′-
Dihydroxy-4-methoxybenzophenone, 2,2 ′
-Dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5
-Sulfobenzophenone and the like are preferable, and among them, 2,2 ', 4,4'-tetrahydroxybenzophenone is preferably used.

As the triazine compound, 2- (4,6
-Diphenyl-1,3,5-triazin-2-yl)-
5-[(hexyl) oxy] -phenol, 2- [4-
[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[( 2-hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl]-
4,6-bis (2,4-dimethylphenyl) -1,3
5-triazine and the like can be mentioned.

Examples of salicylate compounds include phenyl salicylate, pt-butylphenyl salicylate,
-Octylphenyl salicylate. Examples of the cyanoacrylate-based compound include 2-ethylhexyl-2-cyano-3,3 ^, diphenylacrylate, and ethyl-2-cyano-3,3 ^, -diphenylacrylate. Examples of the oxalic acid anilide-based compound include 2-ethoxy-2′-ethyl-oxalic acid bisanilide.

The amount of the UV-absorbing compound used is not particularly limited, but when imparting UV-blocking ability to the coating film, the UV-absorbing compound is usually 20 parts by mass with respect to 100 parts by mass of the acrylic copolymer. The amount is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and the lower limit is usually 0.1 part by mass or more, preferably 1 part by mass or more.

As other optional components, water, an antifoaming agent, a leveling agent, a surface slip agent, and other additives can be added. As the defoaming agent, both mineral oil-based and silicone-based defoaming agents can be suitably used. The addition amount of the defoaming agent can be arbitrarily selected within a range of about 1% by mass or less of the composition as long as the surface of the coating film is not roughened. As the leveling agent, for example, anionic, nonionic,
And various leveling agents such as acetylenic diols. The addition amount is selected within a range of about 1% by mass or less of the composition. Excessive addition is not preferable because it causes bubbles. As the surface slip agent, both reactive and non-reactive silicon compounds can be suitably used. The use of the reactive surface slip agent has an advantage that the coating film can be provided with a slip property with little change over time, and the addition amount is usually 0.0% of the composition.
It is selected in the range of 5 to 1.0% by mass, preferably 0.1 to 0.5% by mass. On the other hand, the non-reactive surface slip agent is usually 0.01 to 0.2% by mass of the composition, preferably 0.02 to 0.2% by mass.
It can be added in the range of 0.1% by mass. The coating composition of the present invention can be obtained by appropriately mixing these components by a known method.

The aqueous coating composition of the present invention does not precipitate an acrylic copolymer, a melamine compound and / or an epoxy compound even when diluted by adding water. It can be a coating liquid. The amount of water is not particularly limited,
100 parts by mass to 1,0 parts per 100 parts by mass of the acrylic copolymer, based on the acrylic copolymer in the composition.
00 parts by mass, preferably about 200 parts by mass to 800 parts by mass.

The aqueous coating solution of the present invention is prepared by applying the coating solution to an object and then applying the coating solution at room temperature (about 25 ° C.)
Alternatively, a coating film (coating film) can be formed by heating. In the present invention, it is more preferable that the coating liquid is kept under heating after application, and the temperature range in this case can be arbitrarily selected within a range in which moisture in the coating film is substantially eliminated, and is usually 200 ° C. or lower. ,
Preferably it is about 70 to 180 ° C. The curing time can also be appropriately selected, and is usually from 10 minutes to 3 hours.
Of course, the film thickness is appropriately selected depending on its use and the like, and is not particularly limited. For example, when a frosted glass-like coating film is to be obtained, it is usually about 1 to 100 μm, preferably 1 to 100 μm.
50 μm. The coating method is not particularly limited, and any ordinary method such as flow coating, dip coating, spray coating, and curtain coating can be suitably used.

[0038]

By using the coating composition and the coating liquid of the present invention, sand blast,
A coating film having a cloudy glass-like appearance excellent in appearance, surface hardness, and durability can be easily obtained by coating without using a technique such as hydrofluoric acid etching. Further, by further blending an ultraviolet absorbing compound with the present coating composition, it is possible to simultaneously impart an ultraviolet blocking function. The present invention
Because it is an aqueous coating composition that uses an acrylic copolymer that can be made water-soluble by neutralization, it features features such as ensuring safety to the human body during use, reducing the risk of fire, and reducing the burden on the environment Also have.

[0039]

The present invention will be specifically described below.
The present invention is not limited to these examples. The GPC measurement performed in the examples was performed under the following conditions. Solvent: tetrahydrofuran Concentration: 1% by mass Column: GMH 6 × 2 Temperature: 23 ° C. Flow rate: 1 mL / min Amount injected: 150 μL Detector: Refractive index Calibration curve: Polystyrene The polymer concentration in the polymerization solution or its concentrated solution is 0 .
4 to 0.6 g is precisely weighed on an aluminum petri dish made constant at 150 ° C., added with 5 g of acetone, spread evenly to a diameter of 7 cm, dried at room temperature for 5 hours, and then dried by heating at 125 ° C. for 4 hours and weighed. I asked by doing. The amount of carboxylic acid residues in the polymer required for the addition of the neutralizing agent is determined by dissolving the polymerization solution or a concentrated solution thereof in propylene glycol monomethyl ether, and adding 0.05 mol / L of propylene glycol monomethyl ether of KOH. Determined by titration with the solution.

(Example 1) Propyl acrylate 500 g Methyl methacrylate 250 g Methacrylic acid 100 g 2-hydroxyethyl acrylate 150 g Azobisisobutyronitrile 30 g The above mixture was refluxed in 2,000 ml of isopropanol.
Was added dropwise over 3 hours, and reflux was further continued for 3 hours to obtain an acrylic copolymer having an acid value of 65.1 and a weight average molecular weight of 16,000. This polymerization solution was concentrated by heating to obtain a solution having a polymer concentration of 50% by mass. Gas chromatography confirmed that this solution contained 50% by mass of isopropanol. To 200 g of this solution, 50 g of a methylated full ether type melamine compound (Cymel 350 manufactured by Mitsui Cytec Co., Ltd.), 0.8 equivalent of triethylamine with respect to the acid value, and 100 g of pure water were added and mixed to prepare a uniform solution. did. Silica particles (Fuji Silysia Chemical Ltd. Silosphere C-1504,
Spherical silica particles, average particle size 4.5 μm, apparent specific gravity 0.
38, and 40 g of refractive index (n ²⁵ _D ) 1.45), and the mixture was stirred with a homomixer at 2,000 rpm for 10 minutes to disperse the particles. To this, water was added to make the whole 1 kg to prepare an aqueous coating solution. The aqueous coating solution was applied to a glass plate with an applicator, dried at 80 ° C. for 30 minutes, and then heated and cured at 150 ° C. for 20 minutes to obtain a cloudy glass-like coating film. The pencil hardness of this coating film was 2H, and the total light transmittance at a wavelength of 589 nm was 73%. A similar coating film was formed on a black plate, and the specular gloss (JIS K5400) at 60 ° was measured.
%, Indicating a good frosted glass appearance.

Example 2 400 g of butyl acrylate 200 g of methyl methacrylate 200 g of benzyl acrylate 100 g of 25 g of methacrylic acid 273 g of 2-hydroxyethyl acrylate 50 g of azobisisobutyronitrile 50 g of the above mixture was added to 2,000 ml of refluxing propanol.
The mixture was added dropwise over a period of time, and reflux was continued for 3 hours to obtain an acid value of 4
An acrylic copolymer having 5.6 and a weight average molecular weight of 1,3000 was obtained. The polymerization solution was concentrated by heating to obtain a solution having a polymer concentration of 35% by mass. Gas chromatography confirmed that this solution contained 65% by mass of propanol. To 285.7 g of this solution, 30 g of a methylated full ether type melamine compound (Cymel 350 manufactured by Mitsui Cytec Co., Ltd.) was added in an amount of 0.3 to the acid value.
9 equivalents of dimethylbenzylamine and 80 g of pure water were added and mixed to prepare a homogeneous solution. Micro acrylic beads (Lab Koror D03 manufactured by Dainichi Seika Kogyo Co., Ltd.)
0, average particle diameter 9 μm, apparent specific gravity 0.51, refractive index (n
²⁵ _D) 1.51) 80g was added 2,0 homomixer
The mixture was stirred at 00 rpm for 10 minutes to disperse the particles. Water was added thereto to make the whole 800 g to prepare an aqueous coating solution. The aqueous coating solution was applied to a glass plate with an applicator, dried at 80 ° C. for 30 minutes, and then heated and cured at 150 ° C. for 20 minutes to obtain a cloudy glass-like coating film. The pencil hardness of this coating film was H, and the total light transmittance at a wavelength of 589 nm was 68%. A similar coating film was formed on a black plate, and the specular gloss at 60 degrees (JIS)
K5400) was 7.3%, indicating a good frosted glass appearance.

Example 3 50 g of acrylic acid 200 g of butyl acrylate 200 g of 2-ethylhexyl acrylate 300 g of vinyltoluene 200 g of benzyl methacrylate 200 g of azobisisobutyronitrile 20 g of diglyme kept at 65 ° C.
Was added dropwise over 3 hours, and the reaction was further performed at 65 ° C. for 3 hours. Then, the temperature was raised to 85 ° C over 1 hour,
For 3 hours to obtain an acrylic copolymer having an acid value of 40.0 and a weight average molecular weight of 60,000. This polymerization solution was concentrated by heating under reduced pressure of 5,000 Pa to obtain a solution having a polymer concentration of 60% by mass. In addition, it was confirmed by gas chromatography that this solution contained 40% by mass of diglymele. To 166.7 g of this solution,
Aqueous epoxy resin (HUX-HW manufactured by Asahi Denka Kogyo Co., Ltd.)
3) 30 g of ethylcellosolve was added to and dissolved in 30 g, and triethanolamine equivalent to 0.8 equivalent to the acid value was added and mixed. To this, 150 g of water was added, and microacrylic beads (MB20 manufactured by Sekisui Chemical Co., Ltd.) were added.
X, average particle diameter 5 μm, apparent specific gravity 0.55, refractive index (n
Added ²⁵ _D) 1.52) 80g, 5 minutes at 1,000 rpm, and stirred for 10 minutes The particles were dispersed in 2,500 rpm, finally the whole 1,500g added water aqueous coating solution Prepared. This aqueous coating solution was applied to a glass plate with a wire bar, dried at 80 ° C. for 10 minutes, and then heated and cured at 160 ° C. for 10 minutes to obtain a cloudy glass-like coating film. This coating has a pencil hardness of H and a wavelength of 589 nm.
Was 74%. A similar coating film was formed on a black plate, and the specular gloss at 60 ° (J
ISK5400) was 4.8%, indicating a good frosted glass appearance.

Example 4 Acrylic acid 100 g N-butoxymethylacrylamide 200 g 2-ethylhexyl acrylate 300 g Styrene 200 g 3-phenoxy-2-hydroxypropyl methacrylate 200 g Azobisisobutyronitrile 60 g Isopropanol kept at 5 ° C
The mixture was dropped into a mixture of 00 g and 500 g of butyl cellosolve over 2 hours, and further reacted at 70 ° C. for 3 hours. Thereafter, the temperature was raised to 85 ° C. over 1 hour, and the reaction was further carried out at 85 ° C. for 3 hours to obtain an acid value of 80.0, a weight average molecular weight of 7,
000 acrylic copolymer was obtained. The polymerization solution was concentrated by heating to obtain a solution having a polymer concentration of 65% by mass. According to gas chromatography, this solution was 30% by mass.
Butyl cellosolve and 5% by mass of isopropanol. 153.8 g of this solution
Water-based epoxy resin (HUX-X manufactured by Asahi Denka Kogyo Co., Ltd.)
W-5) 60 g, and 0.8 equivalent of N,
N-dimethylethanolamine was added and mixed uniformly. 100 g of pure water and 25.6 g of polyethylene beads (Ceraflour902, manufactured by BYK-Chemie, average particle size 5 μm, apparent specific gravity 0.17, refractive index (n ²⁵ _D ) 1.48) were added, and the mixture was stirred at 2,000 rpm for 10 minutes. The particles were dispersed by water, and finally, water was added to make the whole 700 g to prepare an aqueous coating solution. This aqueous coating solution was applied to a glass plate with a wire bar, dried at 80 ° C. for 10 minutes,
The film was cured by heating at 160 ° C. for 10 minutes to obtain a cloudy glass-like coating film. The pencil hardness of this coating film was 3H, and the total light transmittance at a wavelength of 589 nm was 77%. A similar coating film was formed on a black plate, and the specular gloss at 60 degrees (JIS)
K5400) was 6.7%, indicating a good frosted glass appearance.

(Example 5) 65 g of acrylic acid 200 g of butyl acrylate 200 g of 2-ethylhexyl acrylate 335 g of vinyl toluene 200 g of hydroxyethyl methacrylate 200 g of azobisisobutyronitrile 10 g of butyl cellosolve 2,0 kept at 65 ° C.
The mixture was added dropwise to 00 ml over 3 hours, and further reacted at 65 ° C. for 3 hours. Thereafter, the temperature was raised to 85 ° C. over 1 hour, and the reaction was further performed at 85 ° C. for 3 hours.
An acrylic copolymer having a weight average molecular weight of 120,000 was obtained. The polymerization solution was heated and concentrated under reduced pressure of 5,000 Pa to obtain a solution having a polymer concentration of 80% by mass. Gas chromatography confirmed that the solution contained 20% by mass of butyl cellosolve. To 125 g of this solution, 20 g of an aqueous melamine compound (Nikarac SM653 manufactured by Sanwa Chemical Co., Ltd.), 5 g of a triazine-based ultraviolet absorber (Tinuvin 400 manufactured by Ciba Specialty Chemicals, Inc.), and 0.8 to the acid value An equal volume of triethanolamine was added and mixed. Water 18
0 g, and add amorphous silica particles (Nippon Silica Industry Co., Ltd.)
Nippon Silica Nipsil AY460, average particle size 3.7μ
m, apparent specific gravity 0.35, refractive index (n ²⁵ _D ) 1.45)
Add 78 g, 2,000 rpm for 5 minutes, 2,500
The particles were dispersed by stirring at rpm for 10 minutes, and finally, water was added to make the whole to 850 g to prepare an aqueous coating solution. This aqueous coating solution was applied to a glass plate with a wire bar, dried at 80 ° C. for 10 minutes, and then dried at 160 ° C. for 10 minutes.
It was cured by heating for 1 minute to obtain a cloudy glass-like coating film. The pencil hardness of this coating film was F, and the total light transmittance at a wavelength of 589 nm was 68%. In addition, a similar coating film was formed on a black plate,
The specular gloss (JIS K5400) measured at 60 degrees was 8%, indicating a good frosted glass appearance.

Example 6 Acrylic acid 150 g N-butoxymethylacrylamide 200 g 2-hydroxyethyl acrylate 250 g Styrene 200 g 200 g of 3-phenoxy-2-hydroxypropyl methacrylate 60 g Azobisisobutyronitrile 60 g The mixture was added dropwise over 2 hours to a mixture of 1,000 g of isopropanol and 1,000 g of butyl cellosolve kept at 70 ° C., and further reacted at 70 ° C. for 3 hours. Thereafter, the temperature was raised to 85 ° C. over one hour,
The reaction was further performed at 3 ° C. for 3 hours to obtain an acrylic copolymer having an acid value of 8,120 and a weight average molecular weight of 5,000. This polymerization solution was concentrated by heating to obtain a solution having a polymer concentration of 50% by mass. In addition, it was confirmed by gas chromatography that this solution contained 5% by mass of isopropanol and 45% by mass of butyl cellosolve. This solution 200
g, 60 g of a melamine compound (Cymel 327 manufactured by Mitsui Cytec Co., Ltd.), 10 g of a benzotriazole-based ultraviolet absorber (Tinuvin 109 manufactured by Ciba Specialty Chemicals Co., Ltd.), 50 g of butyl cellosolve, and 0 to the acid value. 0.8 equivalent of N, N-dimethylethanolamine was added and mixed uniformly. 80 g of pure water, amorphous silica particles (SS50A manufactured by Nippon Silica Kogyo Co., Ltd., average particle diameter 3 μm, apparent specific gravity 0.15, refractive index (n ²⁵ _D )
1.45) Add 47 g, stir at 2,000 rpm for 10 minutes to disperse the particles, and finally add water to bring the whole to 85.
The aqueous coating solution was prepared at 0 g. This aqueous coating solution was applied to a glass plate with a wire bar,
After drying at ℃ for 10 minutes, it was cured by heating at 160 ℃ for 10 minutes to obtain a cloudy glass-like coating. The pencil hardness of this coating is 3H,
The total light transmittance at a wavelength of 589 nm was 69%. Further, a similar coating film was formed on a black plate, and the specular gloss at 60 ° (JIS K5400) was measured. As a result, it was 4.5%, showing a good frosted glass appearance.

(Example 7) 230 g of acrylic acid 200 g of butyl acrylate 200 g of 2-ethylhexyl acrylate 170 g of vinyl toluene 200 g of benzyl methacrylate 200 g of azobisisobutyronitrile 25 g of isopropanol 2,0 kept at 65 ° C.
The mixture was added dropwise to 00 ml over 3 hours, and further reacted at 65 ° C. for 3 hours. Thereafter, the temperature was raised to 85 ° C. over 1 hour, and the reaction was further performed at 85 ° C. for 3 hours.
An acrylic copolymer having a weight average molecular weight of 30,000 was obtained. The polymerization solution was concentrated by heating to a polymer concentration of 40.
% Solution was obtained. Further, it was confirmed by gas chromatography that this solution contained 60% by mass of isopropanol. To 250 g of this solution, 50 g of an aqueous epoxy resin (HUX-HW5 manufactured by Asahi Denka Kogyo KK),
3 g of a benzophenone-based ultraviolet absorber (uvinul 3035 manufactured by BASF Japan K.K.) and triethanolamine equivalent to 0.8 equivalent to the acid value were further added and mixed. 120 g of water was added thereto, and 80 g of polystyrene beads (SGP50 manufactured by Soken Chemical Co., Ltd., average particle diameter 7 μm, apparent specific gravity 0.59, refractive index (n ²⁵ _D ) 1.58) were added, and the mixture was cooled at 1,000 rpm. Min, 10 at 2,500 rpm
The particles were dispersed by stirring, and finally water was added to make the whole 1,200 g to prepare an aqueous coating solution. This aqueous coating solution was applied to a glass plate with a wire bar, dried at 80 ° C. for 10 minutes, and then heated and cured at 160 ° C. for 10 minutes to obtain a cloudy glass-like coating film. This coating has a pencil hardness of 2H and a total light transmittance of 71% at a wavelength of 589 nm.
Met. A similar coating film was formed on a black plate, and the specular gloss at 60 ° (JIS K5400) was measured. As a result, it was 5.5%, showing a good cloudy glass appearance.

Example 8 135 g of acrylic acid 200 g of N-butoxymethylacrylamide 200 g of 2-ethylhexyl acrylate 200 g of vinyl toluene 200 g of 3-phenoxy-2-hydroxypropyl methacrylate 200 g 25 g of azobisisobutyronitrile Isopropanol 5 maintained at 70 ° C
The mixture was dropped into a mixture of 00 g and 500 g of butyl cellosolve over 2 hours, and further reacted at 70 ° C. for 3 hours. Thereafter, the temperature was raised to 85 ° C. over 1 hour, and the reaction was further carried out at 85 ° C. for 3 hours to obtain an acid value of 105, a weight average molecular weight of 75,
000 acrylic copolymer was obtained. This polymerization solution is
Concentration by heating under reduced pressure of 000 Pa, polymer concentration of 70
% Solution was obtained. In addition, it was confirmed by gas chromatography that this solution contained 1% by mass of isopropanol and 29% by mass of butyl cellosolve. To 142.9 g of this solution, 20 g of an aqueous epoxy resin (HUX-XW-3 manufactured by Asahi Denka Kogyo Co., Ltd.) and N, N-dimethylethanolamine equivalent to 0.8 to the acid value were further added and uniformly added. Mixed. 100 g of pure water and polyurethane beads (CFB200W manufactured by Dainippon Ink and Chemicals, Inc.
Average particle size 10 μm, apparent specific gravity 0.58, refractive index (n ²⁵
_D ) 1.52) Add 72 g and add 10 at 2,000 rpm.
To disperse the particles, and finally add 1,000 parts with water.
g of an aqueous coating solution was prepared. This aqueous coating solution is applied to a glass plate with a wire bar,
After drying for 10 minutes at 160 ° C., the mixture was cured by heating at 160 ° C. for 10 minutes to obtain a cloudy glass-like coating film. The pencil hardness of this coating film was 2H, and the total light transmittance at a wavelength of 589 nm was 63%.
5. A similar coating film was formed on a black plate, and the specular glossiness at 60 ° (JIS K5400) was measured.
2%, showing a good frosted glass appearance.

Continued on the front page F term (reference) 4G059 AA01 AC02 AC07 AC22 FA15 FA28 FA29 FB05 4J038 CB022 CC032 CG002 CG031 CG141 CJ031 CJ101 CJ141 DB042 DB062 DB072 DG002 GA06 GA09 HA216 HA446 JA18 JA26 JA33 J56 JB01 J03 J06 JB01 J03 KA20 MA08 MA10 NA05 NA11 PA19 PC03

Claims (3)

[Claims] (A) an acid value of 20 to 200 mg KOH /
g and a weight average molecular weight of 4,000 to 200,000.
(B) a melamine compound and / or an epoxy compound, based on 100 parts by mass of the acrylic copolymer
30 to 80 parts by mass, (C) a hydrophilic solvent 3 to 200 parts by mass, (D) an ammonia and / or amine compound corresponding to 0.5 to 1.1 equivalents of a carboxyl group contained in the acrylic copolymer. And (E) an aqueous coating composition comprising 30 to 500 parts by mass of particles having an average particle size of 1 to 50 µm. 2. The aqueous coating composition according to claim 1, further comprising an ultraviolet absorbing compound. 3. An aqueous coating solution obtained by mixing water with the aqueous coating composition according to claim 1.