JP2014177598A - Delustering coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a delustering coating composition which can form a delustering coating film which is excellent in alkali resistance, scratching resistance, weather resistance and appearance of a coating film.SOLUTION: A delustering coating composition comprises (A) an acrylic resin-coated silica particle dispersion and (B) a crosslinking agent or (A) an acrylic resin-coated silica particle dispersion, (B) a crosslinking agent and (C) a film-forming resin. The acrylic resin-coated silica particle dispersion (A) is obtained by reacting together (a1) a silica particle, (a2) an alkoxysilyl-containing polymerizable unsaturated monomer and (a3) other polymerizable unsaturated monomers.

Description

  The present invention relates to a matte coating composition capable of forming a matte coating film excellent in alkali resistance, scratch resistance, weather resistance, and coating film appearance.

  Conventionally, a glossy design is generally used for a coating film on a body of an automobile or the like, but recently, a so-called matte design, which has been suppressed as a new design, has attracted attention.

  As a means for forming a coating film exhibiting a matte design (hereinafter sometimes referred to as “matte coating film”), a paint containing silica powder is known. It is said that the reason why the coating film obtained by applying paint containing silica powder exhibits a matte design is that the silica powder forms minute irregularities on the coating surface and light is scattered. ing.

  For example, Patent Document 1 discloses a base resin including a urethane resin, an isocyanate resin and a silica-based matting agent that are combined with the base resin to form a two-component base resin mixture immediately before application of the low-gloss two-component clear coat. Low gloss two-component clear coats containing specific amounts of each are described.

JP 2012-97260 A

  On the other hand, a coating material to be coated on an object such as an automobile body is required to have excellent coating performance such as alkali resistance, scratch resistance, weather resistance and coating appearance.

  However, the matte coating film formed by the low-gloss two-component clear coat described in Patent Document 1 has insufficient alkali resistance, scratch resistance, weather resistance, and coating film appearance.

  Accordingly, an object of the present invention is to provide a matte coating composition capable of forming a matte coating film excellent in alkali resistance, scratch resistance, weather resistance, and coating film appearance.

  The present inventors have intensively studied to solve the above problems. As a result, a matte coating composition characterized by containing an acrylic resin-coated silica particle dispersion, a cross-linking agent, and a film-forming resin has a gloss excellent in alkali resistance, scratch resistance, weather resistance, and coating film appearance. The present inventors have found that an erase coating can be formed and have completed the present invention.

  That is, the present invention contains (A) an acrylic resin-coated silica particle dispersion and (B) a crosslinking agent, or (A) an acrylic resin-coated silica particle dispersion, (B) a crosslinking agent, and (C) a film-forming resin. The present invention provides a matte coating composition characterized by the above.

  Furthermore, this invention provides the articles | goods containing the coating film obtained by apply | coating said mat | matte coating composition.

  Still further, the present invention is a method for forming a multilayer coating film by coating at least one layer of a colored base coat paint and at least one layer of a clear coat paint on an object to be coated. The present invention provides a method for forming a multilayer coating film comprising coating the matte coating composition.

  The matte coating composition of the present invention can form a matte coating film excellent in alkali resistance, scratch resistance, weather resistance and coating film appearance.

Hereinafter, the matte coating composition of the present invention will be described in detail. The matte coating composition of the present invention (hereinafter sometimes abbreviated as “the present coating”) includes (A) an acrylic resin-coated silica particle dispersion and (B) a crosslinking agent, or (A) an acrylic resin-coated silica. A matte paint composition comprising a particle dispersion, (B) a crosslinking agent, and (C) a film-forming resin.

Acrylic resin-coated silica particle dispersion (A)
The acrylic resin-coated silica particle dispersion (A) is a dispersion in which silica particles coated with an acrylic resin are dispersed in a dispersion medium.

  Examples of the dispersion medium include water; alcohol solvents such as methanol, ethanol, isopropanol, n-propanol, isobutanol and n-butanol; polyhydric alcohol solvents such as ethylene glycol; 3-methoxybutyl acetate, butyl pro Esters such as pionate, ethyl-3-ethoxypropionate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, isoamyl acetate, methyl amyl acetate, ethylene glycol monobutyl ether Solvents such as ethylene glycol monoethyl ether and ethylene glycol monobutyl ether; methyl ethyl ketone, methyl isobutyl ketone, methyl pentylke Emissions, ketone solvents such as diacetone alcohol; and the like; toluene, xylene, "SWASOL 1000" (manufactured by Maruzen Petrochemical Co., Ltd., trade name, high-boiling petroleum solvent) aromatic solvents such as. These can be used alone or in combination of two or more. As the dispersion medium, an ester solvent is preferable from the viewpoint of obtaining a coating film having good compatibility with other components contained in the matting coating composition of the present invention and excellent in alkali resistance and the like. -3-Ethoxypropionate is preferred.

  The silica dispersion (A) coated with an acrylic resin is obtained, for example, by reacting silica particles (a1), an alkoxysilyl group-containing polymerizable unsaturated monomer (a2), and other polymerizable unsaturated monomers (a3). Can do.

Silica particles (a1)
The silica particle (a1) is a silica that can be applied to matte purposes by forming a covalent bond by reaction with an alkoxysilyl group-containing polymerizable unsaturated monomer (a2), which will be described later, and capable of surface modification with a polymerizable unsaturated group. Any particle can be used. Examples of such silica particles (a1) include dry silica, wet silica, silica gel, calcium ion exchanged silica fine particles, and colloidal silica.

  In particular, dry silica and wet silica are preferable from the viewpoint of matteness. Among these, wet silica is preferable from the viewpoint of being difficult to absorb the solvent and easy to prepare acrylic resin-coated silica particles. Further, dry silica is also preferable from the viewpoint of exhibiting matting performance in a small amount.

  In the present specification, the polymerizable unsaturated group means an unsaturated group capable of radical polymerization. Examples of the polymerizable unsaturated group include a vinyl group and a (meth) acryloyl group. “(Meth) acryloyl” means “acryloyl or methacryloyl”.

  In the present specification, “(meth) acrylate” means “acrylate or methacrylate”. “(Meth) acrylic acid” means “acrylic acid or methacrylic acid”. “(Meth) acrylamide” means “acrylamide or methacrylamide”.

  1.0-50 micrometers is preferable and, as for the average primary particle diameter of a silica particle (a1), 4.0-40 micrometers is more preferable. If the average primary particle size is less than 1 μm, the matte effect may be inferior. When the average primary particle diameter is 50 μm or more, the appearance of the coating film may be impaired.

  In the present specification, the average primary particle size of the silica particles (a1) refers to the D50 value of the particle size distribution measured using the laser scattering method. The D50 value is a particle size at which the integrated particle size distribution from the small particle size side is 50% from the volume-based particle size distribution. In the present specification, the volume-based particle size distribution of the silica particles was measured using a laser diffraction / scattering particle size distribution measuring device “Microtrack NT3300” (trade name, manufactured by Nikkiso Co., Ltd.). At that time, as a pretreatment, silica particles were added to a mixed solvent of acetone and isopropyl alcohol and dispersed by applying ultrasonic waves for 1 minute, and the silica particle concentration was adjusted to a concentration within a predetermined transmittance range set in the apparatus. .

Examples of commercially available products that can be used as the silica particles (a1) include:
Siricia series (Silicia 350, Siricia 430, Siricia 435, Sirisia 436, Sirisia 450, etc.), Silo Hovic series (Silo Hovic 100, Silo Hovic 200, Silo Hovic 702, Silo Hovic 100) , 4004, etc.), Cyros Sphere series (Cyros Sphere 1504, Cyros Sphere 1510, etc.),
SYLOID series made by Grace Japan (Syloid W300, Syloid W500, etc.)
ACEMATT series (ACEMATT HK460, ACEMATT HK400, ACEMATT OK412, ACEMATT TS100, ACEMATT 3200, ACEMATT 3300, ACEMATT 3600, etc.) manufactured by Evonik Degussa Japan
NIPGEL series (NIPGEL AZ-200 etc.) manufactured by Nippon Silica Kogyo Co., Ltd., NIPSIL series (NIPSIL E-200A etc.),
Mizukasil series (Mizukasil P-73, P-526, etc.) manufactured by Mizusawa Chemical Co., Ltd.
Carplex series (Carplex CS-8 etc.) manufactured by Shionogi & Co., Ltd.
AEROSIL series (AEROSIL 200, AEROSIL R805, AEROSIL R972, etc.) manufactured by Nippon Aerosil Co., Ltd.
Radiolite series (Radiolite 100, Radiolite 200, Radiolite 500, Radiolite 500R, Radiolite 500RS, etc.) manufactured by Showa Chemical Industry Co., Ltd.
Etc.

Alkoxysilyl group-containing polymerizable unsaturated monomer (a2)
Examples of the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) (hereinafter sometimes abbreviated as “monomer component (a2)”) include 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meta ) Acryloyloxypropyltriethoxysilane, 2- (meth) acryloyloxyethyltrimethoxysilane, 2- (meth) acryloyloxyethyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 2- (meth) acryloyl Functional groups other than hydrolyzable silyl groups and unsaturated groups of unsaturated compounds possessed by oxyethylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, various silane coupling agents Except Alkoxysilyl group-containing polymerizable unsaturated monomers obtained by a reaction between the functional groups can be exemplified.

Other polymerizable unsaturated monomers (a3)
As the other polymerizable unsaturated monomer (a3) (hereinafter sometimes abbreviated as “monomer component (a3)”), any polymerizable unsaturated monomer copolymerizable with the monomer component (a2) may be used. Can be used.

  Listed below are preferred monomers as other polymerizable unsaturated monomers (a3).

  (A3-1) Hydroxyl-containing polymerizable unsaturated monomer: The hydroxyl-containing polymerizable unsaturated monomer (a3-1) is a compound having at least one hydroxyl group and one polymerizable unsaturated group in one molecule. As the hydroxyl group-containing polymerizable unsaturated monomer, specifically, a monoesterified product of acrylic acid or methacrylic acid and a dihydric alcohol having 2 to 10 carbon atoms is suitable. For example, 2-hydroxyethyl (meth) Examples thereof include hydroxyalkyl (meth) acrylates such as acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. Furthermore, examples of the hydroxyl group-containing polymerizable unsaturated monomer include ring-opening polymerization adducts of the above hydroxyalkyl (meth) acrylate and lactones such as ε-caprolactone. Specifically, for example, “Plaxel FA-1”, “Plaxel FA-2”, “Plaxel FA-3”, “Plaxel FA-4”, “Plaxel FA-5”, “Plaxel FM-1”, “ “Placcel FM-2”, “Plaxel FM-3”, “Plaxel FM-4”, “Plaxel FM-5” (all are trade names manufactured by Daicel Chemical Industries, Ltd.) and the like.

  (A3-2) Acid group-containing polymerizable unsaturated monomer: a compound having one or more acid groups and one unsaturated bond in one molecule, for example, (meth) acrylic acid, crotonic acid, itaconic acid Carboxyl group-containing polymerizable unsaturated monomers such as maleic acid and maleic anhydride; sulfonic acid group-containing polymerizable unsaturated monomers such as vinyl sulfonic acid and sulfoethyl (meth) acrylate; 2- (meth) acryloyloxyethyl acid Acid phosphate ester polymerizable unsaturated monomers such as phosphate, 2- (meth) acryloyloxypropyl acid phosphate, 2- (meth) acryloyloxy-3-chloropropyl acid phosphate, 2-methacryloyloxyethylphenyl phosphate, etc. .

(A3-3) Monoesterified product of (meth) acrylic acid and a monohydric alcohol having 1 to 20 carbon atoms: for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl ( (Meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isomyristyl (meth) acrylate, isostearyl acrylate (trade name, Osaka Organic (Manufactured by Chemical Industry Co., Ltd.), lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, etc. (a3-4) polymerizable unsaturated monomer having an alicyclic hydrocarbon group: cyclohexyl (meth) acrylate, isobornyl (Meta) ak Relate, tricyclodecanyl (meth) acrylate, adamantyl (meth) acrylate, 3,5-dimethyladamantyl (meth) acrylate, 3-tetracyclododecyl methacrylate, 4-methylcyclohexylmethyl (meth) acrylate, 4-ethylcyclohexyl Methyl (meth) acrylate, 4-methoxycyclohexylmethyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, cyclooctyl (meth) acrylate, cyclododecyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and the like. Of these, cyclohexyl (meth) acrylate and isobornyl (meth) acrylate are preferable from the viewpoint of acid resistance and stain resistance.

  In addition, the polymerizable unsaturated monomer which has both an alicyclic hydrocarbon group and a hydroxyl group shall be contained in a hydroxyl-containing polymerizable unsaturated monomer (a3-1).

  (A3-5) Aromatic polymerizable unsaturated monomer: for example, styrene, α-methylstyrene, vinyltoluene and the like.

  (A3-6) Glycidyl group-containing polymerizable unsaturated monomer: A compound having one glycidyl group and one unsaturated bond in one molecule, specifically glycidyl acrylate, glycidyl methacrylate, and the like.

  (A3-7) Nitrogen-containing polymerizable unsaturated monomer: for example, (meth) acrylamide, dimethylacrylamide, N, N-dimethylpropylacrylamide, N-butoxymethylacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, diacetone Acrylamide, N, N-dimethylaminoethyl (meth) acrylate, vinylpyridine, vinylimidazole and the like.

  (A3-8) Other vinyl compounds: For example, vinyl acetate, vinyl propionate, vinyl chloride, versatic acid vinyl ester “Veoba 9”, “Veoba 10” (trade name, manufactured by Japan Chemtech Co., Ltd.) and the like.

  (A3-9) Unsaturated bond-containing nitrile compound: For example, acrylonitrile, methacrylonitrile and the like.

  The said other copolymerizable polymerizable unsaturated monomer can be used individually or in combination of 2 or more types.

  Especially, it reacts with the crosslinking agent mentioned later, forms a crosslinked coating film, and a hydroxyl-containing polymerizable unsaturated as at least 1 sort of other polymerizable unsaturated monomers (a3) from a viewpoint of improving alkali resistance and weather resistance. It is preferable to use the monomer (a3-1).

  In such a case, the amount of the hydroxyl group-containing polymerizable unsaturated monomer (a3-1) used is 15 to 50 parts by mass, preferably 20 to 45 parts by mass with respect to 100 parts by mass of the other polymerizable unsaturated monomer (a3). More preferably, the content is 25 to 40 parts by mass.

  In addition, from the viewpoint of alkali resistance and weather resistance of the formed coating film, the acid group-containing polymerizable unsaturated monomer (a3-2) may be used as at least one other polymerizable unsaturated monomer (a3). preferable.

  In such a case, the acid group-containing polymerizable unsaturated monomer (a3-2) is used in an amount of 0.05 to 5 parts by mass, preferably 0.005 parts, based on 100 parts by mass of the other polymerizable unsaturated monomer (a3). It is suitable that it is 1-3 mass parts, More preferably, it is 0.5-2 mass parts.

  In addition, from the viewpoints of alkali resistance, scratch resistance, weather resistance, coating film appearance, and the like of the coating film to be formed, polymerization having an alicyclic hydrocarbon group as at least one other polymerizable unsaturated monomer (a3) It is preferable to use a polymerizable unsaturated monomer (a3-4).

  In such a case, the use amount of the polymerizable unsaturated monomer (a3-4) having an alicyclic hydrocarbon group is preferably 1 to 40 parts by mass, preferably 100 parts by mass of the other polymerizable unsaturated monomer (a3). Is preferably 5 to 30 parts by mass, more preferably 10 to 25 parts by mass.

  In addition, from the viewpoint of scratch resistance of the coating film to be formed, it is preferable to use the aromatic polymerizable unsaturated monomer (a3-5) as at least one other polymerizable unsaturated monomer (a3). .

  In this case, the amount of the aromatic polymerizable unsaturated monomer (a3-5) used is 5 to 50 parts by mass, preferably 10 to 40 parts by mass, with 100 parts by mass of the other polymerizable unsaturated monomer (a3). Part, more preferably 15 to 35 parts by weight.

  The hydroxyl value of the acrylic resin of the acrylic resin-coated silica particle dispersion (A) is from 0 to 200 mgKOH / g, particularly from 50 to 180 mgKOH / g, more particularly from 70 to 170 mgKOH / g, from the viewpoint of scratch resistance of the coating film to be formed. It is preferable to be within the range of g.

  The glass transition temperature Tg of the resin covering the acrylic resin-coated silica particle dispersion (A) is in the range of −40 to 40 ° C. from the viewpoint of scratch resistance of the formed coating film. Is preferable, and it is more preferable to be within the range of -30 to 30 ° C.

  In the present invention, the glass transition temperature Tg is a value calculated by the following formula.

1 / Tg (K) = W ₁ / T ₁ + W ₂ / T ₂ +... W _n / T _n
Tg (° C.) = Tg (K) -273
In the formula, W ₁ , W ₂ ,... W _n are mass fractions of each monomer, and T ₁ , T _2, ... T _n are glass transition temperatures Tg (K) of homopolymers of each monomer. .
In addition, the glass transition temperature of the homopolymer of each monomer is POLYMER HANDBOOK Fourth Edition, J. MoI. Brandrup, E .; h. Immergut, E .; A. The glass transition temperature of a monomer not described in the literature, which is a value according to Grulk ed. (1999), was synthesized such that a homopolymer of the monomer had a weight average molecular weight of about 50,000, and its glass transition temperature. Is a value measured by Seiko Electronics Industry DSC220U (differential scanning calorimeter). For measurement, a predetermined amount of 50 mg of sample is weighed on a dedicated sample pan, dried at 130 ° C. for 3 hours, then heated in an inert gas from −50 ° C. to 150 ° C. at a speed of 10 ° C./min, This was carried out by reading the temperature at the inflection point of the obtained heat quantity change curve.

  The weight average molecular weight of the resin coating the acrylic resin-coated silica particle dispersion (A) is within the range of 5000 to 100,000 from the viewpoint of weather resistance, alkali resistance, scratch resistance, coating film appearance, and the like. And more preferably within the range of 8000 to 80000.

  The weight average molecular weight of the resin coating the acrylic resin-coated silica particle dispersion (A) refers to a value obtained by measuring a polymer prepared from the monomer component (a2) and the monomer component (a3) by gel permeation chromatography.

  In addition, in this specification, a weight average molecular weight is the value which converted the weight average molecular weight measured with the gel permeation chromatograph (The Tosoh company make, "HLC8120GPC") on the basis of the weight average molecular weight of polystyrene. Columns are “TSKgel G-4000H × L”, “TSKgel G-3000H × L”, “TSKgel G-2500H × L”, “TSKgel G-2000H × L” (both manufactured by Tosoh Corporation, trade names) ), Mobile phase: tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 cc / min, detector: RI. The number average molecular weight is also a value measured under the same conditions as described above.

Method for Producing Acrylic Resin-Coated Silica Particle Dispersion (A) Examples of a method for obtaining silica particles coated with acrylic resin include silica particles (a1), alkoxysilyl group-containing polymerizable unsaturated monomers (a2), and other polymerizations. And a method of reacting the polymerizable unsaturated monomer (a3).

As a method of reacting the components (a1) to (a3),
Method I: Method of reacting components (a1) to (a3) simultaneously,
Method II: A method of preparing silica particles having a polymerizable unsaturated group from component (a1) and component (a2), and reacting the silica particles with component (a3),
Method III: A method of preparing a polymer having an alkoxylsilyl group from component (a2) and component (a3) and reacting the polymer with component (a1) can be mentioned.

  The blending ratio of each component when producing the acrylic resin-coated silica particle dispersion (A) is the total amount of the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) and the other polymerizable unsaturated monomer (a3) being 100. As a mass part, it is suitable that a silica particle (a1) is 14-700 mass parts, Preferably it is 30-400 mass parts, More preferably, it is 50-300 mass parts.

  When the blending ratio of the silica particles (a1) is less than 14 parts by mass, the resulting coating film may be inferior in matte properties, and when it is more than 700 parts by mass, the resulting acrylic resin-coated silica particle dispersion (A) Since the viscosity of the resin becomes high, handling may be difficult.

  Moreover, the compounding ratio of the silica particles (a1) and the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) is 100 parts by mass of the silica particles (a1) from the viewpoints of the appearance and alkali resistance of the obtained coating film. It is suitable that the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) is 0.2 to 95 parts by mass, preferably 0.5 to 50 parts by mass, and more preferably 1.0 to 10 parts by mass. .

Furthermore, the mixing ratio of the above-mentioned polymerizable unsaturated group-containing silica particles and other polymerizable unsaturated monomer (a3) is [silica particle (a1) and alkoxysilyl group-containing] from the viewpoint of the appearance of the coating film to be formed. The total amount with the polymerizable unsaturated monomer (a2)]: [Other polymerizable unsaturated monomer (a3)] is 20:80 to 90:10, preferably 30:70 to 90, in terms of solid content. It is preferable to be within the range of 70:30.
Method I
The acrylic resin-coated silica particle dispersion (A) polymerizes silica particles (a1), alkoxysilyl group-containing polymerizable unsaturated monomers (a2) and other polymerizable unsaturated monomers (a3) in the presence of a solvent. Can be obtained. Hereinafter, the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) and the other polymerizable unsaturated monomer (a3) may be collectively referred to as “monomer component”.

  The polymerization method is not particularly limited, and a known polymerization method can be used. In particular, a solution for performing polymerization in an organic solvent in the presence of a catalyst, a polymerization initiator, or the like as appropriate. A polymerization method can be suitably used.

  Examples of the organic solvent used in the solution polymerization method include benzene, toluene, xylene, ethylbenzene, “Swazole 1000”, “Swazole 1500” (trade name, manufactured by Maruzen Petrochemical Co., Ltd., high boiling point petroleum solvent), and the like. Hydrocarbon solvents such as aromatic compounds, pentane, hexane, heptane, octane, cyclohexane, cycloheptane, mineral spirits; halogenated hydrocarbons such as trichloroethylene, tetrachloroethylene; ethyl acetate, n-butyl acetate, isobutyl acetate Ester solvents such as ethyl propionate, methyl cellosolve acetate, butyl carbitol acetate, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, ethyl-3-ethoxypropionate; Ketone solvents such as tilethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone; methanol, ethanol, isopropanol, n-butanol, sec-butanol, isobutanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene Examples include alcohol solvents such as glycol monobutyl ether; ether solvents such as n-butyl ether, dioxane, dibutyl ether, and ethylene glycol dimethyl ether; dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, and the like.

  These organic solvents can be used alone or in combination of two or more. Of these, aromatic solvents and ester solvents are preferable from the viewpoint of the appearance of the formed coating film, and ester solvents are more preferable.

  The polymerization initiator that can be used in the polymerization is not particularly limited, and examples thereof include benzoyl peroxide, paramentane hydroperoxide, cumene hydroperoxide, lauroyl peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone. Peroxide, methylcyclohexanone peroxide, tert-butyl peroxypivalate, 1,1′-bis (tert-butylperoxy) cyclohexane, 1,1-bis (tert-butylperoxy) -3,3,5- Trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, 2,2′-di (tert-butylperoxy) butane, tert-butylhydroxyperoxide, 2,5-dimethyl Ruhexane-2,5-dihydroperoxide, di-tert-butyl peroxide, di-n-propyl peroxydicarbonate, tert-hexylperoxy-2-ethylhexanoate, 1,3-bis (tert- Butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, diisopropylbenzene peroxide, tert-butylcumyl peroxide, decanoyl peroxide, lauroyl peroxide Benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, bis (tert-butylcyclohexyl) peroxydicarbonate, tert-butylperoxybenzoate, 2,5-dimethyl-2,5-di (benzoyl peroxide) ) Peroxide polymerization initiators such as hexane and hydrogen peroxide; 1,1-azobis (cyclohexane-1-carbonitrile), azocumene, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2 , 2'-azobis (2-methylbutyronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile, dimethyl 2,2 '-Azobis (2-methylpropionate), 2,2'-di (2-hydroxyethyl) azobisisobutyronitrile, 4,4'-azobis (4-cyanovaleric acid), 2- (tert- Butylazo) -2-cyanopropane, 2,2'-azobis (2,4,4-trimethylpentane), 2,2'-azobis (2-methylpropane), dimethyl 2,2'-azobis (2-mes Til propionate), 2,2′-azobis- (N-butyl-2-methylpropionamide) and other azo polymerization initiators, potassium persulfate, sodium persulfate and other persulfate initiators, peroxides Examples thereof include radical polymerization initiators known per se such as a redox type initiator composed of a reducing agent.

  Further, the acrylic resin-coated silica particle dispersion (A) may contain an unreacted monomer component or a component that has reacted with the monomers without being reacted with the silica particles (a1) to become a polymer. Absent.

  The reaction is preferably carried out with stirring while substituting the gas phase in the reaction vessel with an inert gas from the viewpoint of suppressing polymerization reaction inhibition by oxygen and improving the reaction rate. The reaction temperature and reaction time can be appropriately selected depending on the type of monomer component, etc., but the reaction temperature is preferably in the range of about 0 ° C. to about 250 ° C., and the reaction time is in the range of 1 to 72 hours. Is preferred. The reaction can usually be performed under normal pressure, but can also be performed under pressure or reduced pressure.

The polymerization rate of the monomer component in the above reaction is preferably about 95% or more from the viewpoint of coating film performance such as alkali resistance, scratch resistance and weather resistance. The amount of unreacted monomer component can be reduced by extending the reaction time. Moreover, the amount of unreacted monomer components can also be reduced by adding a radical polymerization initiator and further carrying out the polymerization reaction. Moreover, in the obtained acrylic resin-coated silica particle dispersion (A), the solvent may be replaced with another solvent such as water, if desired.
Method II
The acrylic resin-coated silica particle dispersion (A) is prepared by preparing silica particles having a polymerizable unsaturated group from the silica particles (a1) and the alkoxysilyl group-containing polymerizable unsaturated monomer (a2). The polymerizable unsaturated monomer (a3) can be obtained by a polymerization reaction in the presence of a solvent.

  The method for reacting the silica particles (a1) with the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) is not particularly limited. For example, [i] a method in which silica particles (a1) and an alkoxysilyl group-containing polymerizable unsaturated monomer (a2) are mixed in the presence of an organic solvent containing water and hydrolytic condensation is performed, [ii] water is included. Examples include a method of condensing the hydrolyzate obtained after hydrolyzing the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) in the presence of an organic solvent and the silica particles (a1).

  Here, the water used in these production methods may be water contained in the raw material, for example, water that is a dispersion medium of silica particles.

  By these production methods, the silicon atom on the surface of the silica particle (a1) and the silicon atom of the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) are bonded via an oxygen atom, whereby a siloxane bond is formed. Silica particles having a polymerizable unsaturated group in which the particles (a1) and the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) are chemically bonded can be obtained.

  The acrylic resin-coated silica particle dispersion (A) is obtained by polymerizing the silica particles having a polymerizable unsaturated group obtained above and another polymerizable unsaturated monomer (a3) in the presence of a solvent. Can be obtained. The polymerization method is not particularly limited, and a known polymerization method can be used. In particular, a solution for performing polymerization in an organic solvent in the presence of a catalyst, a polymerization initiator and the like as appropriate. A polymerization method can be suitably used. The solution polymerization method is the same as the method described in Method I.

Further, the acrylic resin-coated silica particle dispersion (A) may contain an unreacted monomer component or a component that has reacted with the monomers without being reacted with the silica particles (a1) to become a polymer. Absent.
Method III
The acrylic resin-coated silica particle dispersion (A) is prepared by preparing a polymer having an alkoxysilyl group from the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) and the other polymerizable unsaturated monomer (a3). The particles (a1) can be obtained by reacting in the presence of a solvent.

  The polymer having an alkoxysilyl group can be obtained by polymerizing an alkoxysilyl group-containing polymerizable unsaturated monomer (a2) and another polymerizable unsaturated monomer (a3) in the presence of a solvent. The polymerization method is not particularly limited, and a known polymerization method can be used. In particular, a solution for performing polymerization in an organic solvent in the presence of a catalyst, a polymerization initiator and the like as appropriate. A polymerization method can be suitably used. The solution polymerization method is the same as the method described in Method I.

  The method for reacting the alkoxysilyl group-containing polymer with the silica particles (a1) is not particularly limited. For example, [i] a method of performing hydrolysis condensation by mixing the hydrolyzable alkoxysilyl group-containing polymer and silica particles (a1) in the presence of an organic solvent containing water, [ii] including water. The method of condensing the hydrolyzate obtained after hydrolyzing the polymer which has the said alkoxy silyl group in presence of an organic solvent, and a silica particle (a1) is mentioned.

  Here, the water used in these production methods may be water contained in the raw material, for example, water that is a dispersion medium of silica particles.

  Further, the acrylic resin-coated silica particle dispersion (A) may contain an unreacted monomer component or a component that has reacted with the monomers without being reacted with the silica particles (a1) to become a polymer. Absent.

  The acrylic resin-coated silica particle dispersion (A) generally has a structure in which the silica particles (a1) are completely covered with the acrylic resin, but the silica particles (a1) and the acrylic resin are generally used. Depending on the mass ratio, the acrylic resin may be insufficient to completely cover the silica particles (a1). In such a case, the acrylic resin-coated silica particle dispersion (A) may have a structure in which a part of the silica particles (a1) is coated with an acrylic resin.

Cross-linking agent (B)
The crosslinking agent (B) is a compound that can react with a functional group such as a hydroxyl group, a carboxyl group, and an epoxy group in the acrylic resin-coated silica particle dispersion (A) to cure the matte coating composition of the present invention. . Examples of the crosslinking agent (B) include polyisocyanate compounds, blocked polyisocyanate compounds, amino resins, epoxy group-containing compounds, carbodiimide group-containing compounds, and the like. Of these, polyisocyanate compounds and amino resins are preferred, and among them, polyisocyanate compounds are preferred. A crosslinking agent (B) can be used individually or in combination of 2 or more types.

Polyisocyanate compound Polyisocyanate compound is a compound having at least two isocyanate groups in one molecule, and includes, for example, aliphatic polyisocyanate, alicyclic polyisocyanate, araliphatic polyisocyanate, aromatic polyisocyanate, And polyisocyanate derivatives.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3. -Aliphatic diisocyanates such as butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, dimer acid diisocyanate, methyl 2,6-diisocyanatohexanoate (common name: lysine diisocyanate); 2 , 6-Diisocyanatohexanoic acid 2-isocyanatoethyl, 1,6-diisocyanato-3-isocyanatomethylhexane, 1,4,8-triisocyanatooctane, 1,6,6 1-triisocyanatoundecane, 1,8-diisocyanato-4-isocyanatomethyloctane, 1,3,6-triisocyanatohexane, 2,5,7-trimethyl-1,8-diisocyanato-5-isocyanatomethyl Examples thereof include aliphatic triisocyanates such as octane.

  Examples of the alicyclic polyisocyanate include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (common name) : Isophorone diisocyanate), 4-methyl-1,3-cyclohexylene diisocyanate (common name: hydrogenated TDI), 2-methyl-1,3-cyclohexylene diisocyanate, 1,3- or 1,4-bis (isocyanato) Methyl) cyclohexane (common name: hydrogenated xylylene diisocyanate) or a mixture thereof, methylenebis (4,1-cyclohexanediyl) diisocyanate (common name: hydrogenated MDI), alicyclic diisocyanate such as norbornane diisocyanate 1,3,5-triisocyanatocyclohexane, 1,3,5-trimethylisocyanatocyclohexane, 2- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2.2 .1) Heptane, 2- (3-isocyanatopropyl) -2,6-di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 3- (3-isocyanatopropyl) -2,5- Di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo (2.2.1) ) Heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, 5- (2-isocyanate) Toethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl) -bicyclo (2.2.1) -heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3 An alicyclic triisocyanate such as -isocyanatopropyl) -bicyclo (2.2.1) heptane can be used.

  Examples of the araliphatic polyisocyanate include methylene bis (4,1-phenylene) diisocyanate (common name: MDI), 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω, ω′-diisocyanato- Aromatic aliphatic diisocyanates such as 1,4-diethylbenzene, 1,3- or 1,4-bis (1-isocyanato-1-methylethyl) benzene (common name: tetramethylxylylene diisocyanate) or mixtures thereof; 1,3 And araliphatic triisocyanates such as 5-triisocyanatomethylbenzene.

  Examples of the aromatic polyisocyanate include m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 2,4-tolylene diisocyanate (common name: 2,4- TDI), 2,6-tolylene diisocyanate (common name: 2,6-TDI) or mixtures thereof, aromatic diisocyanates such as 4,4′-toluidine diisocyanate, 4,4′-diphenyl ether diisocyanate; triphenylmethane-4 , 4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene and the like; 4,4′-diphenylmethane-2,2 ′ , 5,5'-tetraisocyanate and other aromatics Mention may be made of the tiger isocyanate.

  Examples of the polyisocyanate derivatives include dimer, trimer, biuret, allophanate, uretdione, uretoimine, isocyanurate, oxadiazine trione, polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI). And Crude TDI.

  The above polyisocyanates and derivatives thereof may be used alone or in combination of two or more. Of these polyisocyanates, aliphatic diisocyanates and derivatives thereof can be suitably used from the viewpoint of scratch resistance, weather resistance, and the like.

  Further, as the polyisocyanate compound, the polyisocyanate and derivatives thereof and a compound capable of reacting with the polyisocyanate, for example, a compound having an active hydrogen group such as a hydroxyl group or an amino group, are reacted under an excess of isocyanate groups. A prepolymer may be used. Examples of the compound that can react with the polyisocyanate include polyhydric alcohols, low molecular weight polyester resins, amines, and water.

  Moreover, the said polyisocyanate compound can also use the blocked polyisocyanate compound which is a compound which blocked the isocyanate group in the said polyisocyanate and its derivative with the blocking agent.

  Examples of the blocking agent include phenols such as phenol, cresol, xylenol, nitrophenol, ethylphenol, hydroxydiphenyl, butylphenol, isopropylphenol, nonylphenol, octylphenol, and hydroxybenzoic acid methyl; ε-caprolactam, δ-valerolactam, lactams such as γ-butyrolactam, β-propiolactam; aliphatic alcohols such as methanol, ethanol, propyl alcohol, butyl alcohol, amyl alcohol, lauryl alcohol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono Butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene Ethers such as glycol monomethyl ether and methoxymethanol; benzyl alcohol, glycolic acid, methyl glycolate, ethyl glycolate, butyl glycolate, lactic acid, methyl lactate, ethyl lactate, butyl lactate, methylol urea, methylol melamine, diacetone alcohol Alcohols such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate; oximes such as formamide oxime, acetamide oxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzophenone oxime, cyclohexane oxime; dimethyl malonate, diethyl malonate , Active methylenes such as ethyl acetoacetate, methyl acetoacetate, acetylacetone; butyl mercaptan, t-butyl mercapta , Hexyl mercaptan, t-dodecyl mercaptan, 2-mercaptobenzothiazole, thiophenol, methylthiophenol, ethylthiophenol, and other mercaptans; acetanilide, acetanisid, acetolide, acrylamide, methacrylamide, acetic acid amide, stearamide, benzamide, etc. Acid amides; succinimides, phthalic imides, maleic imides and other imides; diphenylamine, phenylnaphthylamine, xylidine, N-phenylxylidine, carbazole, aniline, naphthylamine, butylamine, dibutylamine, butylphenylamine, etc. Amines; Imidazoles such as imidazole and 2-ethylimidazole; Urea, thiourea, ethylene urea, ethylene thiourea, diphenyl urine N- phenylcarbamate ester of carbamic acid such as phenyl; ethyleneimine, imine and propylene imine; urea equal sodium bisulfite, sulfite, such as bisulfite potassium; compounds such azole systems. Examples of the azole compounds include pyrazole, 3,5-dimethylpyrazole, 3-methylpyrazole, 4-benzyl-3,5-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, 4-bromo-3, Pyrazole or pyrazole derivatives such as 5-dimethylpyrazole and 3-methyl-5-phenylpyrazole; Imidazole or imidazole derivatives such as imidazole, benzimidazole, 2-methylimidazole, 2-ethylimidazole and 2-phenylimidazole; 2-methylimidazoline And imidazoline derivatives such as 2-phenylimidazoline.

  In making the block (reacting the blocking agent), a solvent can be added if necessary. As the solvent used for the blocking reaction, those which are not reactive with isocyanate groups are preferable. For example, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, N-methyl-2-pyrrolidone (NMP) Can be mentioned.

  The said polyisocyanate compound can be used individually or in combination of 2 or more types, respectively.

  When a polyisocyanate compound is used as the crosslinking agent (B) in the matte coating composition of the present invention, from the viewpoint of scratch resistance, acid resistance, stain resistance and appearance of the coating film formed, (NCO / OH) between the number of moles of the isocyanate group and the total number of moles of hydroxyl groups in the acrylic resin-coated silica particle dispersion (A) and the film-forming resin (C) to be blended as necessary Is preferably in the range of 0.5 to 2.0, and more preferably in the range of 0.8 to 1.5.

As the amino resin amino resin, a partially methylolated amino resin or a completely methylolated amino resin obtained by a reaction between an amino component and an aldehyde component can be used. Examples of the amino component include melamine, urea, benzoguanamine, acetoguanamine, steroguanamine, spiroguanamine, dicyandiamide and the like. Examples of the aldehyde component include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like.

  Moreover, what methylated the methylol group of the said methylolated amino resin partially or completely with suitable alcohol can also be used. Examples of the alcohol used for etherification include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, 2-ethylbutanol, and 2-ethylhexanol.

  As said amino resin, a melamine resin is preferable. Specific examples of the melamine resin include methylol melamines such as dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, and hexamethylol melamine; alkyl etherified products or condensates of these methylol melamines; Examples thereof include condensates of alkyl ethers. The alkyl etherification of methylolmelamine can be carried out by a known method using monoalcohol such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, 2-ethylhexyl alcohol and the like.

  The melamine resin preferably has a weight average molecular weight in the range of 600 to 6000, more preferably in the range of 800 to 5000, and still more preferably in the range of 1000 to 4000.

  A commercial item can be used as said melamine resin. Commercially available product names include, for example, Cymel 303, Cymel 323, Cymel 325, Cymel 327, Cymel 350, Cymel 370, Cymel 380, Cymel 385, Cymel 212, Cymel 251, Cymel 254, Mymel manufactured by Nippon Cytec Industries, Inc. Coat 776; Resimin 735, Resimin 740, Resimin 741, Resimin 745, Resimin 746, Resimin 747 manufactured by Monsanto; Summar M55, Summar M30W, Summar M50W manufactured by Sumitomo Chemical; Uban 20SB, Uban 20SE- manufactured by Mitsui Chemicals, Inc. 60, Yuban 28-60, and the like.

  The melamine resins can be used alone or in combination of two or more.

Film-forming resin (C)
As the film-forming resin (C), a resin known per se that has been conventionally used in paints can be used. As a kind of resin, an acrylic resin, a polyester resin, an alkyd resin, a polyurethane resin etc. are mentioned, for example.

  The film-forming resin (C) preferably has a crosslinkable functional group in order to react with the crosslinking agent (B) to form a crosslinked coating film. Examples of the crosslinkable functional group include a hydroxyl group, an epoxy group, a carbodiimide group, a carbonyl group, a hydrazide group, and a semicarbazide group, among which a hydroxyl group is preferable.

  Examples of the film-forming resin (C) include a hydroxyl group-containing acrylic resin, a hydroxyl group-containing polyester resin, a hydroxyl group-containing polyurethane resin, and a hydroxyl group-containing epoxy resin. These can be used alone or in combination of two or more.

  Above all, from the point that it is excellent in compatibility with the acrylic resin-coated silica particle dispersion (A), and is excellent in matting properties, weather resistance, alkali resistance, scratch resistance, coating film appearance, and the like of the obtained coating film. The film-forming resin (C) is preferably a hydroxyl group-containing acrylic resin.

  Among these, the film-forming resin (C) has a hydroxyl value of 80 to 200 mgKOH / g and a weight average molecular weight from the viewpoint of excellent weather resistance, alkali resistance, scratch resistance, coating film appearance, and the like of the obtained coating film. It is preferable that it is a hydroxyl-containing acrylic resin which is 2500-40000.

The hydroxyl group-containing acrylic resin can be produced by copolymerizing a hydroxyl group-containing polymerizable unsaturated monomer and other polymerizable unsaturated monomers by a conventional method.
As the hydroxyl group-containing polymerizable unsaturated monomer, the hydroxyl group-containing polymerizable unsaturated monomer (a3-1) described in the column of the component (A) can be used. These monomers can be used alone or in combination of two or more.

  As said other polymerizable unsaturated monomer, the monomer of (a3-2)-(a3-9) described in the column of the component (A) can be used. These monomers can be used alone or in combination of two or more.

  The amount of the hydroxyl group-containing polymerizable unsaturated monomer used is 15 to 50 parts by mass, preferably 20 to 45 parts by mass, more preferably 100 parts by mass based on the amount of the polymerizable unsaturated monomer used for the production of the hydroxyl group-containing acrylic resin. Is preferably 25 to 40 parts by mass.

  When the amount of the hydroxyl group-containing polymerizable unsaturated monomer used is less than 15 parts by mass, the cured coating film may be insufficiently crosslinked, and it may be difficult to obtain predetermined alkali resistance and scratch resistance. On the other hand, when it exceeds 50 parts by mass, the compatibility with other polymerizable unsaturated monomers and the copolymerization reactivity are lowered, and the compatibility with other components in the coating is further lowered, so that the finished appearance of the coating film May decrease.

  In addition, from the viewpoint of excellent weather resistance, alkali resistance, scratch resistance, and the like of the formed coating film, it is preferable to use an acid group-containing polymerizable unsaturated monomer as at least one other polymerizable unsaturated monomer.

  In this case, the amount of the acid group-containing polymerizable unsaturated monomer used is 0.05 to 5 parts by mass, preferably 0.1, based on 100 parts by mass of the polymerizable unsaturated monomer used for producing the hydroxyl group-containing acrylic resin. It is suitable that it is -3 mass parts, More preferably, it is 0.5-2 mass parts.

  Further, from the viewpoint of the alkali resistance of the coating film to be formed, the coating film appearance, etc., it is preferable to use a polymerizable unsaturated monomer having an alicyclic hydrocarbon group as at least one other polymerizable unsaturated monomer. .

  In this case, the amount of the polymerizable unsaturated monomer having an alicyclic hydrocarbon group is 1 to 40 parts by weight, preferably 100 parts by weight of the polymerizable unsaturated monomer used for the production of the hydroxyl group-containing acrylic resin, preferably It is suitable that it is 5-30 mass parts, More preferably, it is 10-25 mass parts.

  Further, from the viewpoint of alkali resistance, scratch resistance, etc. of the coating film to be formed, it is preferable to use an aromatic polymerizable unsaturated monomer as at least one other polymerizable unsaturated monomer.

  In such a case, the amount of the aromatic polymerizable unsaturated monomer used is 5 to 50 parts by mass, preferably 10 to 40 parts by mass, based on 100 parts by mass of the polymerizable unsaturated monomer used for producing the hydroxyl group-containing acrylic resin. More preferably, it is 15 to 35 parts by mass.

  The copolymerization method for copolymerizing the above polymerizable unsaturated monomers to obtain a hydroxyl group-containing acrylic resin is not particularly limited, and a copolymerization method known per se can be used. Among them, a solution polymerization method in which polymerization is performed in the presence of a polymerization initiator can be preferably used.

  Examples of the organic solvent used in the solution polymerization method include aromatic solvents such as toluene, xylene, and swazole 1000 (trade name, high-boiling petroleum solvent) manufactured by Cosmo Oil; ethyl acetate, 3-methoxybutyl Ester solvents such as acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, propyl propionate, butyl propionate, ethoxy ethyl propionate, etc. Can be mentioned.

  These organic solvents can be used alone or in combination of two or more. From the viewpoint of the solubility of the hydroxyl group-containing acrylic resin used in the paint, high boiling ester solvents and ketone solvents can be used. It is preferable to use it. In addition, aromatic solvents having higher boiling points can be suitably used in combination.

  Examples of the polymerization initiator that can be used for copolymerization of the hydroxyl group-containing acrylic resin include 2,2′-azobisisobutyronitrile, benzoyl peroxide, di-t-butyl peroxide, di-t-amyl peroxide, Mention may be made of radical polymerization initiators known per se, such as t-butyl peroctoate and 2,2′-azobis (2-methylbutyronitrile).

  The hydroxyl value of the hydroxyl group-containing acrylic resin is in the range of 80 to 200 mgKOH / g, more preferably in the range of 100 to 170 mgKOH / g. When the hydroxyl value is less than 80 mgKOH / g, the weather resistance, alkali resistance, scratch resistance, and coating film appearance may be insufficient due to low crosslinking density. On the other hand, if it exceeds 200 mgKOH / g, the water resistance of the coating film may decrease.

  The weight average molecular weight of the hydroxyl group-containing acrylic resin is in the range of 2500 to 40000, more preferably in the range of 5000 to 30000. If the weight average molecular weight is less than 2500, the coating performance such as weather resistance, alkali resistance, scratch resistance, and coating appearance may be reduced, and if it exceeds 40000, the smoothness of the coating will be reduced. The finish may be reduced.

  In addition, in this specification, a weight average molecular weight is the value which converted the weight average molecular weight measured with the gel permeation chromatograph (The Tosoh company make, "HLC8120GPC") on the basis of the weight average molecular weight of polystyrene. Columns are “TSKgel G-4000H × L”, “TSKgel G-3000H × L”, “TSKgel G-2500H × L”, “TSKgel G-2000H × L” (both manufactured by Tosoh Corporation, trade names) ), Mobile phase: tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 cc / min, detector: RI. The number average molecular weight is also a value measured under the same conditions as described above.

  The glass transition temperature of the hydroxyl group-containing acrylic resin is usually in the range of −40 ° C. to 85 ° C., particularly preferably in the range of −30 ° C. to 80 ° C. When the glass transition temperature is less than −40 ° C., the coating film hardness may be insufficient, and when it exceeds 85 ° C., the coated surface smoothness of the coating film may be deteriorated.

  The hydroxyl group-containing polyester resin that can be used as the film-forming resin (C) can be produced by a conventional method, for example, by an esterification reaction between a polybasic acid and a polyhydric alcohol. The polybasic acid is a compound having two or more carboxyl groups in one molecule. For example, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, tetrahydrophthalic acid, hexa And hydrophthalic acid, maleic acid, fumaric acid, itaconic acid, trimellitic acid, pyromellitic acid and their anhydrides. The polyhydric alcohol contains two or more hydroxyl groups in one molecule. For example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-diethyl-1,3 -Propanediol, neopentyl glycol, 1,9-nonanediol, 1,4-cyclohexanediol, hydroxy Diols such as valinic acid neopentyl glycol ester, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethylpentanediol, hydrogenated bisphenol A, etc. , And trivalent or higher polyol components such as trimethylolpropane, trimethylolethane, glycerin, pentaerythritol, and the like, and 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylol Examples thereof include hydroxycarboxylic acids such as pentanoic acid, 2,2-dimethylolhexanoic acid, and 2,2-dimethyloloctanoic acid.

  In addition, α-olefin epoxides such as propylene oxide and butylene oxide, monoepoxy compounds such as Cardura E10 (manufactured by Japan Epoxy Resin Co., Ltd., trade name, glycidyl ester of synthetic hyperbranched saturated fatty acid) and the like are reacted with acids, and these are reacted. A compound may be introduced into the polyester resin.

  When introducing a carboxyl group into a polyester resin, for example, it can be introduced by adding an acid anhydride to a hydroxyl group-containing polyester and half-esterifying it.

  The hydroxyl value of the hydroxyl group-containing polyester resin is in the range of 80 to 200 mgKOH / g, more preferably in the range of 100 to 170 mgKOH / g. When the hydroxyl value is less than 80 mgKOH / g, the weather resistance, alkali resistance, scratch resistance, coating film appearance, etc. may be insufficient, and when it exceeds 200 mgKOH / g, the water resistance of the coating film decreases. There is.

  The weight average molecular weight of the hydroxyl group-containing polyester resin is in the range of 2500 to 40000, more preferably in the range of 5000 to 30000. When the weight average molecular weight is less than 2500, the coating performance such as weather resistance, alkali resistance, scratch resistance and coating appearance may be deteriorated. When the weight average molecular weight exceeds 40000, the coating surface smoothness of the coating decreases. There is a case.

  The glass transition temperature of the hydroxyl group-containing polyester resin is usually in the range of −40 ° C. to 85 ° C., particularly preferably in the range of −30 ° C. to 80 ° C. When the glass transition temperature is less than −40 ° C., the coating film hardness may be insufficient, and when it exceeds 85 ° C., the coated surface smoothness of the coating film may be deteriorated.

  The film-forming resin (C) also includes so-called urethane-modified acrylic resins and urethane-modified polyester resins.

  Examples of the hydroxyl group-containing polyurethane resin that can be used as the film-forming resin (C) include a hydroxyl group-containing polyurethane resin obtained by reacting a polyol and a polyisocyanate.

  Examples of the polyol include dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, and hexamethylene glycol, and trihydric alcohols such as trimethylolpropane, glycerin, and pentaerythritol. Can do. Examples of the high molecular weight material include polyether polyol, polyester polyol, acrylic polyol, and epoxy polyol. Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples of the polyester polyol include alcohols such as the above divalent alcohols, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol, and dibasic acids such as adipic acid, azelaic acid, and sebacic acid. Lactone-based ring-opening polymer polyol such as polycaprolactone, polycarbonate diol, and the like. Moreover, for example, carboxyl group-containing polyols such as 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid can also be used.

  Examples of the polyisocyanate to be reacted with the above polyol include aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and lysine diisocyanate; and burette type addition of these polyisocyanates. Product, isocyanurate cycloadduct; isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4- (or-2,6-) diisocyanate, 1,3- (or 1,4-) Alicyclic diisocyanates such as di (isocyanatomethyl) cyclohexane, 1,4-cyclohexane diisocyanate, 1,3-cyclopentane diisocyanate, 1,2-cyclohexane diisocyanate And burette type adducts, isocyanurate cycloadducts of these polyisocyanates; xylylene diisocyanate, metaxylylene diisocyanate, tetramethyl xylylene diisocyanate, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5- Naphthalene diisocyanate, 1,4-naphthalene diisocyanate, 4,4-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, (m- or p-) phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethyl- Aromatic diisos such as 4,4'-biphenylene diisocyanate, bis (4-isocyanatophenyl) sulfone, isopropylidenebis (4-phenylisocyanate) And burette-type adducts, isocyanurate cycloadducts of these polyisocyanates; triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatobenzene, 2, Polyisocyanates having three or more isocyanate groups in one molecule such as 4,6-triisocyanatotoluene, 4,4′-dimethyldiphenylmethane-2,2 ′, 5,5′-tetraisocyanate; and And polyisocyanate burette type adducts, isocyanurate ring adducts, and the like.

  The hydroxyl value of the hydroxyl group-containing polyurethane resin is in the range of 80 to 200 mgKOH / g, more preferably in the range of 100 to 170 mgKOH / g. When the hydroxyl value is less than 80 mgKOH / g, the weather resistance, alkali resistance, scratch resistance, coating film appearance, etc. may be insufficient, and when it exceeds 200 mgKOH / g, the water resistance of the coating film decreases. There is.

  The weight average molecular weight of the hydroxyl group-containing polyurethane resin is in the range of 2500 to 40000, more preferably in the range of 5000 to 30000. When the weight average molecular weight is less than 2500, the coating performance such as weather resistance, alkali resistance, scratch resistance and coating appearance may be deteriorated. When the weight average molecular weight exceeds 40000, the coating surface smoothness of the coating decreases. There is a case.

  The glass transition temperature of the hydroxyl group-containing polyurethane resin is usually in the range of −40 ° C. to 85 ° C., particularly preferably in the range of −30 ° C. to 80 ° C. When the glass transition temperature is less than −40 ° C., the coating film hardness may be insufficient, and when it exceeds 85 ° C., the coated surface smoothness of the coating film may be deteriorated.

Matte paint composition The matte paint composition of the present invention comprises the acrylic resin-coated silica particle dispersion (A) and the crosslinking agent (B),
Alternatively, it is a matte coating composition comprising the acrylic resin-coated silica particle dispersion (A), the crosslinking agent (B), and the film-forming resin (C).

  In the present specification, the matte coating composition refers to a composition having a 60 ° specular reflectance value of less than 40 when the formed coating film is measured according to JIS K 5600-4-7: 1999.

  Further, in the matte coating composition of the present invention, the blending ratio (solid content mass) of each component is the matteness, weather resistance, alkali resistance, scratch resistance, coating film appearance, etc. of the matte coating film to be formed. In view of the above, it is preferably within the following range.

The total amount of the alkoxysilyl group-containing polymerizable unsaturated monomer (a2), other polymerizable unsaturated monomer (a3), crosslinking agent (B) and film-forming resin (C) is 100 parts by mass,
Silica particles (a1): 4 to 100 parts by mass, preferably 5 to 50 parts by mass, more preferably 6 to 15 parts by mass,
Total amount of alkoxysilyl group-containing polymerizable unsaturated monomer (a2) and other polymerizable unsaturated monomer (a3): 1 to 80 parts by mass, preferably 2 to 74 parts by mass, more preferably 5 to 60 parts by mass,
Crosslinking agent (B): 20 to 60 parts by mass, preferably 25 to 50 parts by mass, more preferably 30 to 45 parts by mass,
Film-forming resin (C): 0 to 79 parts by mass, preferably 1 to 65 parts by mass, more preferably 10 to 60 parts by mass.

  In addition, the matting coating composition of the present invention may further include a matting agent other than the acrylic-coated silica particle dispersion (A), an organic solvent, a curing catalyst, a pigment, a pigment dispersant, a leveling agent, and an ultraviolet absorber as necessary. Additives for paints that are usually used in the field of paints such as additives, light stabilizers, and plasticizers can be contained.

  As the matting agent other than the acrylic-coated silica particle dispersion (A), a known matting agent can be used as long as it does not impair the alkali resistance, scratch resistance, weather resistance and coating appearance of the resulting coating film. For example, glass, silica, resin beads and the like can be mentioned. When silica is used as the matting agent, it may be untreated or treated, but when treated silica is used, the treatment is performed according to the acrylic coating of the present invention. It is different from processing.

Examples of the curing catalyst include tin octylate, dibutyltin di (2-ethylhexanoate), dioctyltin di (2-ethylhexanoate), dioctyltin diacetate, dibutyltin dilaurate, dibutyltin oxide, and dioctyl. Organometallic catalysts such as tin oxide and lead 2-ethylhexanoate, tertiary amines, sulfonic acids such as paratoluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, salts of these acids with amines, etc. Can be mentioned. These can be used alone or in combination of two or more.
When the matte coating composition of the present invention contains a curing catalyst, the blending amount of the curing catalyst is in the range of 0.05 to 10 parts by mass based on 100 parts by mass of the solid content in the matte coating composition. It is preferable that it is in the range of 0.1 to 5 parts by mass, and more preferably in the range of 0.2 to 3 parts by mass.

  Examples of the pigment include titanium oxide, zinc white, carbon black, cadmium red, molybdenum red, chromium yellow, chromium oxide, Prussian blue, cobalt blue, azo pigment, phthalocyanine pigment, quinacridone pigment, isoindoline pigment, selenium pigment, and perylene. Colored pigments such as pigments; body pigments such as talc, clay, kaolin, barita, barium sulfate, barium carbonate, calcium carbonate, and alumina white; metallic pigments such as aluminum powder, mica powder, and mica powder coated with titanium oxide be able to. These can be used alone or in combination of two or more.

  When the matte paint composition of the present invention is used as a clear paint and contains a pigment, the amount of the pigment is preferably an amount that does not hinder the transparency of the resulting coating film. For example, it is usually preferably in the range of 0.1 to 20 parts by mass, more preferably in the range of 0.3 to 10 parts by mass based on 100 parts by mass of the solid content in the matte coating composition. Preferably, it is in the range of 0.5 to 5 parts by mass.

  Further, when the matte paint composition of the present invention is used as a colored paint and contains a pigment, the blending amount of the pigment is based on 100 parts by mass of the solid content in the matte paint composition. Usually, it is preferably within the range of 1 to 200 parts by mass, more preferably within the range of 2 to 100 parts by mass, and even more preferably within the range of 5 to 50 parts by mass.

  As the ultraviolet absorber, conventionally known ones can be used, and examples thereof include ultraviolet absorbers such as benzotriazole absorbers, triazine absorbers, salicylic acid derivative absorbers, and benzophenone absorbers. These can be used alone or in combination of two or more.

  When the matte coating composition of the present invention contains an ultraviolet absorber, the blending amount of the ultraviolet absorber is 0.1 to 10 parts by mass based on 100 parts by mass of the solid content in the matte coating composition. It is preferably within the range, more preferably within the range of 0.2 to 5 parts by mass, and even more preferably within the range of 0.3 to 2 parts by mass.

  A conventionally well-known thing can be used as a light stabilizer, for example, a hindered amine light stabilizer can be mentioned.

  When the matte coating composition of the present invention contains a light stabilizer, the blending amount of the light stabilizer is 0.1 to 10 parts by mass based on 100 parts by mass of the solid content in the matte coating composition. It is preferably within the range, more preferably within the range of 0.2 to 5 parts by mass, and even more preferably within the range of 0.3 to 2 parts by mass.

  The matte paint composition of the present invention may be a one-component paint or a multi-component paint such as a two-component paint. In the matte coating composition of the present invention, when a non-blocked polyisocyanate compound is used as the crosslinking agent (B), the acrylic resin-coated silica particle dispersion (A ) And the film-forming resin (C) and a cross-linking agent containing the non-blocked polyisocyanate compound, and the two can be mixed and used immediately before use. preferable.

Coating method The coating material to which the matte coating composition of the present invention (hereinafter may be abbreviated as “the present coating”) is not particularly limited, but includes, for example, cold-rolled steel sheet, zinc Examples thereof include steel plates such as plated steel plates, zinc alloy plated steel plates, stainless steel plates, and tin plated steel plates, metal substrates such as aluminum plates and aluminum alloy plates, and various plastic materials. Moreover, the vehicle body of various vehicles, such as a motor vehicle, a two-wheeled vehicle, and a container formed of these, may be sufficient.

  Moreover, as a to-be-coated object, surface treatments, such as a phosphate process, a chromate process, complex oxide process, may be given to the metal surface of the said metal base material or a vehicle body. Further, as the object to be coated, an undercoat film such as various electrodeposition paints may be formed on the metal substrate or the vehicle body, and the undercoat film and the intermediate coat film are formed. It may be an undercoating film, an intermediate coating film, and a base coating film, and an undercoating film, an intermediate coating film, a base coating film, and a clear coating film are formed. It may be.

  The coating method of the paint is not particularly limited, and examples thereof include air spray coating, airless spray coating, rotary atomization coating, curtain coat coating, and the like. Can be formed. In these coating methods, electrostatic application may be performed as necessary. Of these, air spray coating or rotary atomization coating is particularly preferred. In general, the coating amount of the paint is preferably set to an amount of about 10 to 50 μm as a cured film thickness.

  When air spray coating, airless spray coating, and rotary atomization coating are performed, the viscosity of the coating is adjusted to a viscosity range suitable for the coating, usually Ford Cup No. In a 4-viscosity meter, it is preferable to adjust appropriately using a solvent such as an organic solvent so that the viscosity is within a range of about 15 to 60 seconds at 20 ° C.

  Curing of the wet coating film formed by applying the coating material to the object to be coated is performed by heating, and the heating can be performed by a known heating means, such as a hot air furnace, an electric furnace, an infrared induction heating furnace, etc. Any drying oven can be used. The heating temperature is not particularly limited, and is preferably in the range of 60 to 180 ° C, preferably 90 to 150 ° C, for example. The heating time is not particularly limited, and for example, 10 to 60 minutes, preferably 15 to 30 minutes is suitable.

  Since this coating material can obtain a cured coating film excellent in all of scratch resistance, acid resistance, stain resistance, and coating film appearance, it can be suitably used as a top-coat top clear coat coating material. This paint can be particularly suitably used as an automobile paint.

Multi-layer coating film forming method As a multi-layer coating film forming method in which this paint is applied as a top-top clear coat paint, at least one colored base coat paint and at least one clear coat paint are sequentially applied to an object to be coated. It is a method of forming a multilayer coating film by doing, Comprising: The multilayer coating-film formation method including apply | coating the mat paint composition of this invention as a clear coat coating of the uppermost layer can be mentioned.

  Specifically, for example, a base coat paint is applied on an object to which electrodeposition coating and / or intermediate coating is applied, and the solvent in the base coat paint is cured as necessary without curing the coating film. In order to promote volatilization, for example, preheating is performed at 40 to 90 ° C. for about 3 to 30 minutes, and after applying this paint as a clear coat paint on the uncured base coat film, the base coat and the clear coat are applied. An example of the method is a two-coat one-bake type multi-layer coating method in which the coats are cured together.

  Moreover, this paint can also be suitably used as a top clear coat paint in the top coat of the 3-coat 2-bake method or the 3-coat 1-bake method.

  As the base coat paint used in the above, a conventionally known normal thermosetting base coat paint can be used. Specifically, for example, a base resin such as an acrylic resin, a polyester resin, an alkyd resin, a urethane resin type, or the like. In addition, a coating material obtained by appropriately combining a reactive functional group contained in the base resin with a crosslinking agent such as an amino resin, a polyisocyanate compound, or a block polyisocyanate compound can be used.

  As the base coat paint, for example, an aqueous paint, an organic solvent-based paint, and a powder paint can be used. Of these, water-based paints are preferable from the viewpoint of reducing environmental burden.

  In the multilayer coating film forming method, when two or more clear coats are applied, a conventionally known normal thermosetting clear coat paint can be used as the clear coat paint other than the uppermost layer.

  In the matte coating composition of the present invention, the silica particles of the acrylic resin-coated silica particle dispersion (A) ensure abrasion resistance and matte properties, and the acrylic resin part is crosslinked with the crosslinking agent (B) to be resistant to alkali. It is considered that it contributes to the formation of a coating film excellent in scratch resistance, weather resistance and coating film appearance.

  When the matte coating composition of the present invention further contains a film-forming resin (C), an acrylic resin-coated silica particle dispersion (A), a crosslinking agent (B), and a film-forming resin (C) Is considered to be excellent in alkali resistance, scratch resistance, weather resistance and coating film appearance. In particular, when a hydroxyl group-containing acrylic resin is used as the film-forming resin (C), the compatibility with the acrylic resin-coated silica particle dispersion (A) is excellent. Conceivable.

  Hereinafter, the present invention will be described more specifically with reference to production examples, examples and comparative examples. However, the present invention is not limited to these. In each example, “parts” and “%” are based on mass unless otherwise specified. Moreover, the film thickness of a coating film is based on a cured coating film. Furthermore, the compounding quantity in a table | surface is solid content mass.

Production and production example 1 of acrylic resin-coated silica particle dispersion (A)
A separable flask equipped with a reflux condenser, a thermometer, a stirrer and a nitrogen introduction tube was charged with 30 parts of ethoxyethyl propionate, stirred, heated to 95 ° C. while introducing nitrogen, and styrene 15 Parts, isobornyl acrylate 23 parts, 2-ethylhexyl acrylate 23 parts, 4-hydroxybutyl acrylate 1 part, hydroxyethyl acrylate 37 parts, acrylic acid 1 part, 3-methacryloyloxypropyltrimethoxysilane 5 parts, V-59 ( A solution obtained by stirring and mixing 6 parts of a trade name, an azo radical polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd.) and 5 parts of ethoxyethyl propionate was dropped over 4 hours. Next, after aging for 0.5 hour, a mixed solution of 1 part of V-59 and 4 parts of ethoxyethyl propionate was added, and further aging was performed for 0.5 hour to obtain an acrylic resin solution.

  Subsequently, 105 parts of “ACEMATT TS100” (trade name, manufactured by Evonik Degussa Japan, silica powder, average primary particle size of 10 μm) are attached to a separable flask equipped with a reflux condenser, a thermometer, a stirrer, and a nitrogen introduction tube. Then, 105 parts of the above acrylic resin solution as a solid content, 1 part of deionized water, 70 parts of propylene glycol monomethyl ether, and 1820 parts of ethoxyethyl propionate are charged, stirred, and heated to 110 ° C. while introducing nitrogen. The reaction was carried out for 1 hour. Subsequently, it concentrated by carrying out the azeotropic distillation in a pressure-reduced state, and obtained acrylic resin coating silica particle dispersion (A-1) (nonvolatile content 20%).

Production Examples 2-6, 8-29
Acrylic resin-coated silica particle dispersions (A-2) to (A-6), in the same manner as in Production Example 1, except that each component and blending amount were changed to the respective components and blending amounts shown in Table 1. (A-8) to (A-29) were obtained.

  In addition, the method of obtaining the acrylic resin-coated silica particles of Production Examples 1 to 5 and 8 to 29 is based on Method III of the present specification. Production Example 6 is according to Method II.

  Moreover, the detail of each silica particle brand name in Table 1 is as follows.

“Silysia 350”: trade name, manufactured by Fuji Silysia, silica powder, average primary particle size 3.7 μm
“Silysia 450”: trade name, manufactured by Fuji Silysia, silica powder, average primary particle size 8.0 μm
“Radiolite 500RS”: trade name, manufactured by Showa Chemical Co., Ltd., silica powder, average primary particle size 47 μm
“AEROSIL R972”: trade name, manufactured by Nippon Aerosil Co., Ltd., silica powder, average primary particle size 63 μm
“ACEMATT 3600”: trade name, manufactured by Evonik Degussa Japan, modified silica powder with unsaturated groups introduced, average primary particle size 5 μm
Production Example 7 (Method I)
In a separable flask equipped with a reflux condenser, a thermometer, a stirrer and a nitrogen introduction tube, 105 parts of “ACEMATT TS100”, 1 part of deionized water, 70 parts of propylene glycol monomethyl ether, 1820 parts of ethoxyethyl propionate Charge, stir, and raise temperature to 95 ° C. while introducing nitrogen, to which 15 parts of styrene, 23 parts of isobornyl acrylate, 23 parts of 2-ethylhexyl acrylate, 1 part of 4-hydroxybutyl acrylate, 37 parts of hydroxyethyl acrylate A solution prepared by stirring 1 part of acrylic acid, 5 parts of 3-methacryloyloxypropyltrimethoxysilane, 6 parts of V-59, and 5 parts of ethoxyethyl propionate was added dropwise over 4 hours. Next, after aging for 0.5 hour, a mixed solution of 1 part of V-59 and 4 parts of ethoxyethyl propionate was added, and further aging was performed for 0.5 hour. Subsequently, it concentrated by carrying out the azeotropic distillation in a pressure-reduced state, and obtained the acrylic resin coating silica particle dispersion (A-7) (nonvolatile content 20%).

Production and production example 30 of film-forming resin (C)
31 parts of ethoxyethyl propionate was charged into a four-necked flask equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet, and the temperature was raised to 120 ° C. under nitrogen gas flow. After reaching 120 ° C., nitrogen gas aeration was stopped, and a monomer mixture composed of the following monomer and polymerization initiator was added dropwise over 4 hours.
Styrene 15 parts Isobornyl acrylate 23 parts 2-ethylhexyl acrylate 23 parts 4-hydroxybutyl acrylate 1 part 2-hydroxyethyl acrylate 37 parts acrylic acid 1 part di-t-amyl peroxide 1.75 parts After aging for 1 hour while venting the gas, a mixture of 0.5 parts of t-butylperoxy-2-ethylhexanoate and 5 parts of ethoxyethyl propionate was added dropwise over 1 hour, and then about 120 parts. By aging at 2 ° C. for 1 hour and diluting with 27.5 parts of ethoxyethyl propionate, a film-forming resin (C-1) solution which is a hydroxyl group-containing acrylic resin having a solid content of 60% was obtained. The hydroxyl value based on the solid content of the obtained film-forming resin was 161 mgKOH / g, and the weight average molecular weight was 13,000.

Production Examples 31-38
Film-forming resins (C-2) to (C-9) were obtained in the same manner as in Production Example 30, except that the respective components and amounts were changed to the respective components and amounts described in Table 2.

Production Example 1 of Matte Coating Composition
15 parts by weight of the acrylic resin-coated silica particle dispersion (A-1) obtained in Production Example 1, “Duranate TLA-100” (trade name, manufactured by Asahi Kasei Chemicals Corporation, isocyanurate of hexamethylene diisocyanate, 40 parts of solid content 100%, isocyanate group content 23.5%) and 57 parts of the film-forming resin (C-1) obtained in Production Example 30 were mixed uniformly in solid content.

  Next, butyl acetate was added to the resulting mixture, and Ford Cup No. A matte coating composition (X-1) having a viscosity of 25 and having a viscosity of 25 seconds was obtained.

Examples 2 to 43 and Comparative Example 1
Matte paint compositions (X-2) to (X-44) were obtained in the same manner as in Example 1 except that the respective components and amounts were changed to the respective components and amounts described in Table 3. .

  The details of the crosslinking agent (B) shown in Table 3 are as follows.

“Sumijour BL3175”: trade name, manufactured by Sumika Bayer Urethane Co., Ltd., hexamethylene diisocyanurate oxime blocked, solid content 75%, isocyanate group content 11.2%
Melamine resin A: Methylol group and imino group-containing butyl etherified melamine resin, weight average molecular weight 4000, per triazine nucleus, 1.0 imino group, 0.4 methylol group, 4.6 butyl ether group Synthesized melamine resin, solid content 50%

Preparation of test plate "ELECRON GT-10" (trade name, thermosetting epoxy resin-based cationic electrodeposition paint, manufactured by Kansai Paint Co., Ltd.) on a 0.8 mm thick dull steel plate subjected to zinc phosphate conversion treatment Electrodeposited to a cured film thickness of 20 μm, cured by heating at 170 ° C. for 30 minutes, and “TP-65-2” (trade name, manufactured by Kansai Paint Co., Ltd., polyester / melamine resin-based automobile) The intermediate coating was applied by air spray so that the cured film thickness was 35 μm, and was cured by heating at 140 ° C. for 30 minutes. “WBC-713T No. 202” (manufactured by Kansai Paint Co., Ltd., acrylic / melamine resin water-based base coat for automobiles, black coating color) was applied on the coating film so as to have a film thickness of 15 μm and allowed to stand at room temperature for 5 minutes. After allowing to stand and preheating at 80 ° C. for 10 minutes, the matte coating compositions (X-1) to (X-44) shown in Table 3 are cured to 35 μm on the uncured coating film. The coating was left to stand at room temperature for 10 minutes and then heated at 140 ° C. for 20 minutes to cure both coating films together to obtain a test plate. The performance test results of the obtained coating film are also shown in Table 3.

Performance test method Matting property: Evaluated based on the value of 60 ° specular reflectance measured based on JIS K 5600-4-7: 1999. Evaluation was made according to the following criteria. ○ and Δ are acceptable.

○: 60 ° specular reflectance value is less than 20 Δ: 60 ° specular reflectance value is 20-40
×: 60 ° specular reflectance value of 40 or more Alkali resistance:
After dropping 0.5 mL of 1% sodium hydroxide aqueous solution on the coating film surface of the test plate and leaving it in an atmosphere at a temperature of 20 ° C. and a relative humidity of 65% for 24 hours, the coated surface is wiped with gauze and the appearance is visually observed. The evaluation was based on the following criteria. ○ and Δ are acceptable.

○: No abnormalities on the coating film surface △: Discoloration (whitening) of the coating film surface is observed ×: Discoloration (whitening) on the coating film surface is remarkable Coating film appearance: It was evaluated with. ○ and Δ are acceptable.

○: There is no unevenness on the coating film surface. Δ: Unevenness is observed on the coating film surface. ×: Unevenness on the coating film surface is remarkable.
An automobile with a test plate attached to the roof with a water-resistant tape manufactured by Nichiban Co., Ltd. was visually evaluated according to the following criteria for the appearance of the coated surface after being washed 15 times with a car wash machine at 20 ° C. . ○ and Δ are acceptable.

○: No scratch on the coating film surface Δ: Scratch is observed on the coating film surface ×: Scratch on the coating film surface is remarkable Weather resistance:
Each test coated plate was irradiated for 1000 hours in accordance with the accelerated weather resistance test of JIS K 5600-7-7 (xenon lamp method), and then each coated plate surface was evaluated by the degree of chalking according to JIS K 5600-8-6. did. ○ and Δ are acceptable.

○: No abnormalities on the coating film surface △: Discoloration (chalking) on the coating film surface is observed ×: Discoloration (chalking) on the coating film surface is remarkable

Claims (11)

(A) acrylic resin-coated silica particle dispersion and (B) a crosslinking agent,
Or
A matte paint composition comprising (A) an acrylic resin-coated silica particle dispersion, (B) a crosslinking agent, and (C) a film-forming resin.   An acrylic resin-coated silica particle dispersion (A) obtained by reacting (a1) silica particles, (a2) an alkoxysilyl group-containing polymerizable unsaturated monomer, and (a3) other polymerizable unsaturated monomer The matte coating composition according to claim 1, which is a silica particle dispersion.   The matte coating composition according to claim 1 or 2, wherein the silica particles (a1) have an average primary particle size of 1.0 to 50 µm. Acrylic resin-coated silica particle dispersion (A)
The total amount of the alkoxysilyl group-containing polymerizable unsaturated monomer (a2) and the other polymerizable unsaturated monomer (a3) is 100 parts by mass,
The matte paint composition according to any one of claims 1 to 3, which is an acrylic resin-coated silica particle dispersion obtained by reacting 14 to 700 parts by mass of silica particles (a1). The content of silica particles (a1) is
The total solid content of the alkoxysilyl group-containing polymerizable unsaturated monomer (a2), the other polymerizable unsaturated monomer (a3), the crosslinking agent (B), and the film-forming resin (C) is 4 to 100, based on 100 parts by mass. The matte coating composition according to any one of claims 1 to 4, wherein the matte coating composition is in the range of parts by mass.   The matte coating composition according to any one of claims 1 to 5, wherein the other polymerizable unsaturated monomer (a3) contains a hydroxyl group-containing polymerizable unsaturated monomer (a3-1).   The total amount of other polymerizable unsaturated monomers (a3) is 100 parts by mass, and the hydroxyl group-containing polymerizable unsaturated monomer (a3-1) is contained in an amount of 15 to 50 parts by mass. The matte paint composition as described.   The matte coating composition according to any one of claims 1 to 7, wherein the crosslinking agent (B) is a polyisocyanate compound or a melamine resin.   The film-forming resin (C) is a hydroxyl group-containing acrylic resin (C1) having a hydroxyl value of 80 to 200 mgKOH / g and a weight average molecular weight of 2500 to 40000, according to any one of claims 1 to 8. Matte paint composition.   An article comprising a coating film obtained by applying the matte coating composition according to any one of claims 1 to 9.   A method for forming a multi-layer coating film by coating at least one layer of a colored base coat paint and at least one layer of a clear coat paint on an object to be coated, the top layer being a clear coat paint. A method for forming a multilayer coating film comprising applying the matte coating composition according to any one of the above.