JP2021181518A - Matte paint composition - Google Patents

Abstract

To provide a matte paint composition that has matched hue and matte feeling between a repaired matte coating film and old matte coating film, without depending on a coating environment and without substantially containing toluene or xylene, and is suitable for forming a repaired matte coating film without giving a feeling of incompatibility with the old matte coating composition, and a repairing coating method of a coated body.SOLUTION: A matte paint composition includes a main agent (I) and a curing agent (II), in which: the main agent (I) contains a hydroxy group containing acrylic resin (A), a matte agent (B) containing silica particles (b1), and an organic solvent (C); the organic solvent (C) contains an organic solvent (c1) having solubility (20°C) to water in the range of 5 to 50 g/100 g, and having a boiling point of 100 to lower than 190°C; and a content ratio of the silica particles (b1) and the organic solvent contained in the main agent (I) is in the range of 70/30 to 10/90.SELECTED DRAWING: None

Description

The present invention relates to a matte coating composition.

Conventionally, a glossy design has been generally used for the outer panel coating film of a vehicle body of an automobile or the like, but in recent years, a so-called matte design in which gloss is suppressed has been attracting attention as a new design.

As a means for forming a coating film exhibiting a matte design (hereinafter, may be referred to as "matte coating film"), for example, Patent Document 1 describes a low-gloss two-component clear coat containing a urethane resin. Described is a low-gloss two-component clear coat containing a base resin, an isocyanate resin that is combined with the base resin to form a two-component base resin mixture immediately before application of the low-gloss two-component clear coat, and a silica-based matting agent. Has been done.

By the way, in the case of repair painting an object provided with a high-quality coating film such as an automobile body, it is required that the repair coating film formed by the repair coating has a finished appearance equivalent to that of the existing coating film. Further, in order to apply repair coating to the completed automobile body, it is required to dry the repair coating film at a low temperature so that parts such as equipment inside the body are not affected.

Also, in the case of new painting, the painting environment is significantly different depending on each repair painting site compared to the stable industrial painting line within the control range, so it is installed with the repair coating film at all repair painting sites. It is an issue to obtain a finished appearance that does not give a sense of discomfort with the coating film of.

On the other hand, in general, a paint prepared by a paint manufacturer cannot be used as it is due to its high viscosity and the like, and the paint manufacturer ships it to a distributor together with diluted thinner. The painter purchases both products from the distributor and mixes the paint and the diluted thinner for painting in order to adjust the viscosity and painting workability according to the purpose.

In recent years, volatile organic compounds such as toluene and xylene, which have been conventionally blended in the field of paints, have been regarded as regulated substances as environmental pollutants, and the regulations have been further tightened. Both paints and diluted thinners are required to reduce or substantially eliminate these regulated substances.

In particular, in the repair painting of automobile bodies and parts or the painting of objects to be coated that do not enter the drying furnace, the paint film after painting cannot be dried at a high temperature, and paints and thinners that are friendly to the human body and the environment are used. Not only the color of the existing coating film but also the matte feeling and its degree must be reproduced with the repair matte coating film. In the case of new painting, the painting environment is stable within the control range of the industrial painting line, but there are cases where each repair painting site is painted outdoors or in a place where there is no painting booth. Painting conditions, such as humidity conditions, are not constant, and there are many cases where the painting environment differs depending on the summer or winter. Since the painting environment differs greatly depending on each painting site compared to when the entire surface of the target parts and body is painted on an industrial painting line, the degree of matting with the surrounding area is adjusted to the same degree, and there is no discomfort. There was a problem in finishing it.

Patent Document 2 proposes a matte coating repair method. In the present invention, the case where the coating film thickness or the coating environment fluctuates is not taken into consideration, and the gloss of the formed coating film may fluctuate greatly. That is, the gloss stability may be insufficient.

Patent Document 3 proposes a matte coating repair method for repairing coating defects such as lumps generated in a matte coating film. However, in the actual automobile repair site, it is not always possible to paint with the same paint and in the same environment, and the gloss stability may be insufficient and the matte feeling may not match between the old paint film and the repaired part. rice field. In addition, the drying property is often insufficient, and problems such as sagging may occur.

Japanese Unexamined Patent Publication No. 2012-97260 Japanese Unexamined Patent Publication No. 10-286520 Japanese Unexamined Patent Publication No. 2007-84726

The color and matte feeling of the repaired matte coating film and the old matte coating film match, regardless of the painting environment and substantially free of toluene, xylene, etc., to make the old matte coating film. On the other hand, it is an object of the present invention to propose a matte coating composition and a repair coating method for a coated body, which are suitable for forming a repair matte coating film without a sense of discomfort.

As a result of diligent research, the present inventors have found that the above problems can be solved.

The present invention includes embodiments shown below:
Item 1.
A matte coating composition containing a main agent (I) and a curing agent (II).
The main agent (I) contains a hydroxyl group-containing acrylic resin (A), a matting agent (B) containing silica particles (b1), and an organic solvent (C).
The organic solvent (C) contains an organic solvent (c1) having a solubility (20 ° C.) in water in the range of 5 to 50 g / 100 g and a boiling point of less than 100 to 190 ° C., and
The content ratio of the silica particles (b1) and the organic solvent (c1) contained in the main agent (I) is
A matte coating composition characterized by being in the range of 70/30 to 10/90.

Item 2.
Item 2. The matte coating composition according to Item 1, wherein the content of the organic solvent (c1) is in the range of 5 to 55% by mass with respect to the total mass of all the solvents contained in the matte coating composition. ..

Item 3.
Item 2. The matte coating composition according to Item 1 or Item 2, wherein the hydroxyl group-containing acrylic resin (A) contains a resin having a glass transition temperature of 30 ° C. or higher.

Item 4.
Item 6. The matte coating composition according to any one of Items 1 to 3, wherein the silica particles (b1) are organically treated silica particles (b1').

Item 5.
Items 1 to 4 in which the content of the silica particles (b1) is in the range of 5 to 40 parts by mass with respect to 100 parts by mass of the resin solid content of the hydroxyl group-containing resin (A) contained in the main agent (I). The matte coating composition according to any one of the above.

Item 6.
Item 6. The matte coating composition according to any one of Items 1 to 5, wherein the curing agent (II) contains a polyisocyanate compound (D).

Item 7.
Item 6. The matte coating composition according to any one of Items 1 to 6, wherein the main agent (I) further contains a rheology control agent (E).

Item 8.
Item 2. The matte coating composition according to Item 7, wherein the rheology control agent (E) contains crosslinked polymer fine particles (e1).

Item 9.
A coating film forming method for forming a coating film on the outermost surface by applying the matte coating composition according to any one of Items 1 to 8 to an object to be coated.

Item 10.
Step (1) of applying a primer surfacer to a damaged portion of an old coating film or a coated body to form a base-treated coating film (I).
Step (2) of coating the coloring base coating film composition on the undercoat coating film to form the coloring base coating film (II).
The step (3), in which the clear coating composition is applied onto the colored base coating film obtained in the step (2) and dried to form the clear coating film (III).
A method for repairing and painting a painted body, wherein the clear paint composition is the matte paint composition according to any one of Items 1 to 8.

Item 11.
Step (1) of applying a primer surfacer to a damaged portion of an old coating film or a coated body to form a base-treated coating film (I).
Step (2) of coating the coloring base coating film composition on the undercoat coating film to form the coloring base coating film (II).
The step (3), in which the first clear coating film composition (CC1) is coated on the colored base coating film obtained in the step (2) and dried to form the first clear coating film (III).
A coated body comprising a step (4) of coating a second clear coating film composition (CC2) on the first clear coating film obtained in the step (3) to form a second clear coating film (IV). It is a repair painting method of
The repair coating method for a coated body, wherein the second clear coating composition (CC2) is the matte coating composition according to any one of Items 1 to 8.

According to the composition of the present invention, the dryness is excellent regardless of the coating environment, and the color and matte feeling of the repaired matte coating film and the old matte coating film match, and the old matte coating film is used. It is possible to form a repair matte coating film that does not give a sense of discomfort to the film. In addition, the occurrence of glossiness can be suppressed even in the low glossiness range of 60 ° gloss value of 1 to 40, where glossiness is particularly noticeable. Further, it is possible to obtain a coating film having excellent gloss stability and matte property even by normal temperature drying or forced drying under relatively mild temperature conditions, which is often applied in the field of automobile repair or the like.

Hereinafter, the matte coating composition of the present invention (hereinafter, may be abbreviated as “the present coating”) and the method for forming a multi-layer coating film will be described in detail.

The matte coating composition of the present invention contains a main agent (I) and a curing agent (II).
A matte coating composition containing a main agent (I) and a curing agent (II).
The main agent (I) contains a hydroxyl group-containing acrylic resin (A), a matting agent (B) containing silica particles (b1), and an organic solvent (C). The organic solvent (C) contains an organic solvent (c1) having a solubility in water (20 ° C.) within a specific range and a boiling point within a specific range, and is contained in the main agent (I). The content ratio of the particles (b1) and the organic solvent (c1) is in the range of 70/30 to 10/90. This will be described in detail below.

<Main agent (I)>
In the present invention, the hydroxyl group-containing acrylic resin (A) contained in the main agent (I) is a component that reacts with the curing agent (II) described later and both becomes a film-forming component.

Hydroxy group-containing acrylic resin (A)
The hydroxyl group-containing acrylic resin (A) can be produced by copolymerizing a hydroxyl group-containing polymerizable unsaturated monomer (a1) and another polymerizable unsaturated monomer (a2) by a known method.

The hydroxyl group-containing polymerizable unsaturated monomer (a1) is a compound having one or more hydroxyl groups and one or more polymerizable unsaturated groups in one molecule. As the hydroxyl group-containing polymerizable unsaturated monomer (a1), 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. Examples thereof include hydroxyalkyl (meth) acrylates such as (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. Further, as the hydroxyl group-containing polymerizable unsaturated monomer (a1), a ring-opening polymerization adduct of the hydroxyalkyl (meth) acrylate and a lactone compound such as ε-caprolactone can also be mentioned. Specific examples of the ring-opening polymerization adduct include "Plaxel FA-1", "Plaxel FA-2", "Plaxel FA-3", "Plaxel FA-4", and "Plaxel FA-5". "Plaxel FM-1", "Plaxel FM-2", "Plaxel FM-3", "Plaxel FM-4", "Plaxel FM-5" (all of which are manufactured by Daicel Chemical Co., Ltd., trade names) and the like. be able to. These hydroxyl group-containing polymerizable unsaturated monomers (a1) can be used alone or in combination of two or more.

In addition, in this specification, "(meth) acrylate" means "acrylate or methacrylate". "(Meta) acrylic acid" means "acrylic acid or methacrylic acid". Further, "(meth) acrylamide" means "acrylamide or methacrylamide".

Examples of the other polymerizable unsaturated monomer (a2) include the following monomers (a2-1) to (a2-8).

(A2-1) Acid group-containing polymerizable unsaturated monomer:
A compound having one or more acid groups and one polymerizable unsaturated group in one molecule, for example, a carboxyl group such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid and maleic anhydride. Containing polymerizable unsaturated monomer; sulfonic acid group-containing polymerizable unsaturated monomer such as vinyl sulfonic acid and sulfoethyl (meth) acrylate; 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxypropyl acid phosphate. , 2- (meth) acryloyloxy-3-chloropropyl acid phosphate, 2-metacroyloxyethylphenyl phosphate and the like, acid phosphate ester-based polymerizable unsaturated monomers and the like are included.

(A2-2) A 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, manufactured by Osaka Organic Chemical Industry Co., Ltd.), lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, etc. Is included.

(A2-3) Polymerizable unsaturated monomer having an alicyclic hydrocarbon group:
Cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, adamantyl (meth) acrylate, 3,5-dimethyladamantyl (meth) acrylate, 3-tetracyclododecylmethacrylate, 4-methylcyclohexyl Methyl (meth) acrylate, 4-ethylcyclohexylmethyl (meth) acrylate, 4-methoxycyclohexylmethyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, cyclooctyl (meth) acrylate, cyclododecyl (meth) acrylate, tetrahydro Includes full frill (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.

The polymerizable unsaturated monomer having both an alicyclic hydrocarbon group and a hydroxyl group is included in the hydroxyl group-containing polymerizable unsaturated monomer (a1).

(A2-4) Aromatic polymerizable unsaturated monomer:
For example, styrene, α-methylstyrene, vinyltoluene and the like are included.

(A2-5) Glycidyl group-containing polymerizable unsaturated monomer:
A compound having one glycidyl group and one polymerizable unsaturated group in one molecule, and specifically, glycidyl acrylate, glycidyl methacrylate and the like are included.

(A2-6) Nitrogen-containing polymerizable unsaturated monomer:
For example, (meth) acrylamide, dimethylacrylamide, N, N-dimethylpropylacrylamide, N-butoxymethylacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, diacetoneacrylamide, N, N-dimethylaminoethyl (meth) acrylate. , Vinyl pyridine, vinyl imidazole and the like.

(A2-7) Other vinyl compounds:
For example, vinyl acetate, vinyl propionate, vinyl chloride, "Beova 9" and "Beova 10" (trade name, manufactured by HEXION), which are versatic vinyl esters, and the like are included.

(A2-8) Polymerizable unsaturated group-containing nitrile compound:
For example, acrylonitrile, methacrylonitrile and the like are included.

The above-mentioned other copolymerizable polymerizable unsaturated monomers can be used alone or in combination of two or more.

The amount of the hydroxyl group-containing polymerizable unsaturated monomer (a1) used is 5 to 50 parts by mass, preferably 10 to 50 parts by mass, with the amount of the polymerizable unsaturated monomer used for producing the hydroxyl group-containing acrylic resin (A) being 100 parts by mass. It is preferably 45 parts by mass, more preferably 15 to 40 parts by mass.

When the amount of the hydroxyl group-containing polymerizable unsaturated monomer (a1) used is 15 parts by mass or more, it is preferable because a predetermined alkali resistance can be easily obtained by crosslinking in the cured coating film. On the other hand, when the content is 50 parts by mass or less, the compatibility with the other polymerizable unsaturated monomer (a2) and / or the copolymerization reactivity is improved, and the compatibility with other components in the coating material is further improved. This is preferable because the finished appearance of the coating film is improved.

Further, from the viewpoint of weather resistance, alkali resistance, etc. of the formed coating film, an acid group-containing polymerizable unsaturated monomer (a2-1) is used as at least one of the other polymerizable unsaturated monomers (a2). Is preferable.

In this case, the amount of the acid group-containing polymerizable unsaturated monomer (a2-1) used is 0.05 to 5 with the amount of the polymerizable unsaturated monomer used for producing the hydroxyl group-containing acrylic resin (A) as 100 parts by mass. It is preferably 0.1 to 3 parts by mass, more preferably 0.5 to 2 parts by mass.

Further, from the viewpoint of alkali resistance of the formed coating film, appearance of the coating film, etc., the polymerizable unsaturated monomer (a2) having an alicyclic hydrocarbon group is used as at least one of the other polymerizable unsaturated monomers (a2). It is preferable to use -3).

In this case, the amount of the polymerizable unsaturated monomer (a2-3) having an alicyclic hydrocarbon group is 100 parts by mass with the amount of the polymerizable unsaturated monomer used for producing the hydroxyl group-containing acrylic resin (A) as 100 parts by mass. It is preferably 1 to 40 parts by mass, preferably 10 to 40 parts by mass, and more preferably 20 to 40 parts by mass.

Further, from the viewpoint of alkali resistance of the formed coating film, it is preferable to use an aromatic polymerizable unsaturated monomer (a2-4) as at least one of the other polymerizable unsaturated monomers (a2). ..

In this case, the amount of the aromatic polymerizable unsaturated monomer (a2-4) used is 5 to 50 parts by mass, where 100 parts by mass is the amount of the polymerizable unsaturated monomer used for producing the hydroxyl group-containing acrylic resin (A). It is preferably 5 to 40 parts by mass, more preferably 5 to 30 parts by mass.

The copolymerization method for copolymerizing the above-mentioned polymerizable unsaturated monomer to obtain the hydroxyl group-containing acrylic resin (A) is not particularly limited, and a copolymerization method known per se can be used. However, a solution polymerization method in which polymerization is carried out in an organic solvent in the presence of a polymerization initiator can be preferably used.

Examples of the organic solvent used in the above solution polymerization method include aromatic solvents such as toluene, xylene, and "Swazole 1000" (manufactured by Cosmo Petroleum Co., Ltd., trade name, high boiling point petroleum solvent); ethyl acetate, butyl acetate. , 3-methoxybutyl acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propyl propionate, butyl propionate, ethoxyethyl propionate and other ester solvents; methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone and the like. Examples include the ketone solvent of.

These organic solvents can be used alone or in combination of two or more. In the present invention, the use of an ester solvent or a ketone solvent having a medium to high boiling point of about 100 ° C. to 200 ° C. dissolves the hydroxyl group-containing acrylic resin (A) used in the matte coating composition of the present invention. Butyl acetate is particularly preferable from the viewpoint of sex. Further, in addition to these organic solvents, a high boiling point aromatic solvent can be used in a suitable combination, but in consideration of the influence on the environment and the human body, toluene and xylene may not be substantially contained. preferable. It is preferable that toluene or xylene is not used as an organic solvent at all during the synthesis, or the solvent is substituted after the synthesis to make it less than 0.1% by mass.

Examples of the polymerization initiator that can be used for the copolymerization of the hydroxyl group-containing acrylic resin (A) include 2,2'-azobisisobutyronitrile, benzoyl peroxide, di-t-butyl peroxide, and di-t-amyl. Examples thereof include radical polymerization initiators known per se, such as peroxide, t-butylperoctate, and 2,2'-azobis (2-methylbutyronitrile).

The hydroxyl value of the hydroxyl group-containing acrylic resin (A) is preferably in the range of 80 to 200 mgKOH / g, and more preferably in the range of 100 to 170 mgKOH / g. When the hydroxyl value is 80 mgKOH / g or more, the desired weather resistance, alkali resistance, and coating film appearance can be easily obtained because the crosslink density is high. Further, when it is 200 mgKOH / g or less, the water resistance of the coating film is improved, which is preferable.

The weight average molecular weight of the hydroxyl group-containing acrylic resin (A) is preferably in the range of 2500 to 40,000, and more preferably in the range of 4000 to 30000 from the viewpoint of high solid differentiation and finishability of the coating material. Is. A weight average molecular weight of 2500 or more is preferable because it is easy to obtain coating film performance such as desired weather resistance, alkali resistance, and coating film appearance. Further, when the weight average molecular weight is 40,000 or less, the smoothness of the coating film is improved, so that the finishability is improved, which is preferable.

In the present specification, the weight average molecular weight is a value obtained by converting the weight average molecular weight measured by a gel permeation chromatograph (manufactured by Tosoh Corporation, “HLC8120GPC”) based on the weight average molecular weight of polystyrene. The columns are "TSKgel G-4000H x L", "TSKgel G-3000H x L", "TSKgel G-2500H x L", "TSKgel G-2000H x L" (all manufactured by Tosoh Corporation, trade name). ), Mobile phase; tetrahydrofuran, measurement temperature; 40 ° C., flow rate; 1 mL / min, detector; RI conditions. The number average molecular weight is also a value measured under the same conditions as above.

The glass transition temperature of the hydroxyl group-containing acrylic resin (A) is usually adjustable in the range of -40 ° C to 85 ° C, but from the viewpoint of dryness, it is preferably 30 ° C or higher, preferably in the range of 40 ° C to 85 ° C. be. When the glass transition temperature is 30 ° C. or higher, the drying property of the coating film is good and a desired coating film hardness can be obtained, and when it is 85 ° C. or lower, the coating surface smoothness of the coating film is improved, which is preferable.

In order to obtain such an acrylic resin having a high glass transition temperature, among other polymerizable unsaturated monomers, a monomer having a homopolymer glass transition temperature of 30 ° C. or higher as a part of its copolymerization component is preferably 40. It is desirable to contain a monomer in the range of about 130 ° C. from the viewpoint of improving the drying property.

The content of the monomer having a glass transition temperature of 30 ° C. or higher in the homopolymer is 10 parts by mass or more, preferably 10 parts by mass or more, with the amount of the polymerizable unsaturated monomer used for producing the hydroxyl group-containing acrylic resin (A) being 100 parts by mass. It is preferably 30 to 80 parts by mass, more preferably 40 to 70 parts by mass.

Here, the glass transition temperature of the monomer in the present specification is the glass transition temperature of the homopolymer of each monomer in Polymer Handbook (4th Edition, J. Brandup E. H. Immunogut). The glass transition temperature of a monomer not described in the document is when a homopolymer of the monomer is synthesized so that the weight average molecular weight is about 50,000, and the glass transition temperature is measured by differential scanning calorimetry. Use the value.

Specific examples of the monomer having a glass transition temperature of 30 ° C. or higher of the homopolymer include styrene, methyl methacrylate, ethyl methacrylate, and methacrylate having a branched alkyl group having 3 to 4 carbon atoms, for example, i-propyl methacrylate. (Meta) acrylate having a cyclic alkyl structure such as cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, etc., cetyl acrylate (also known as hexadecyl acrylate), benzyl methacrylate, etc., such as i-butyl methacrylate and tert-butyl methacrylate. , Other examples include isostearyl acrylate, stearyl methacrylate and the like.

The hydroxyl group-containing acrylic resin (A) can be used alone or in combination of two or more.

The content of the hydroxyl group-containing acrylic resin (A) contained in the main agent (I) is 50 to 100% by mass with respect to the total resin solid content contained in the main agent (I) from the viewpoint of weather resistance and drying property. Further, it is preferably in the range of 70 to 100% by mass.

Matte (B)
As the matting agent (B), silica particles (b1) are essentially contained.

By containing the silica particles (b1) in a specific ratio with the organic solvent (c1) described later, it is possible to obtain a coating film having very good matting property and excellent drying property regardless of the painting environment.

The shape of the silica particles (b1) is not particularly limited, and spherical, hollow, porous, rod-shaped, plate-shaped, fibrous, or indefinite shapes can be used.

The silica particles (b1) may be untreated particles, or may be surface-treated particles with an organic compound or an inorganic compound. Among them, organically treated silica particles (b1') are particularly preferable from the viewpoint of alkali resistance, gloss stability and the like. Examples of the treatment with the organic compound include polyethylene treatment, polyethylene wax treatment, hydrophobic surface treatment and the like.

Examples of commercially available products that can be used as the silica particles (b1) include the Siricia series manufactured by Fuji Silysia Chemical Ltd. ("Siricia 350", "Siricia 430", "Siricia 435", "Siricia 436", "Siricia 450", etc. ), Silohobic series ("Silohobic 100", "Silohobic 200", "Silohobic 702", "Silohobic 4004", etc.), Silos Fair series ("Silos Fair 1504", "Silos Fair") 1510 ", etc.), Grace Japan's SYLOID series ("Siloid W300", "Siloid W500", etc.), Evonik Degussa Japan's ACEMATT series ("ACEMATT HK460", "ACEMATT HK400", "ACEMATT OK412", "ACEMATT OK412" ACEMATT OK520, ACEMATT OK607, ACEMATT TS100, ACEMATT 3200, ACEMATT 3300, ACEMATT 3600, etc. "NIPSIL E-200A", "NIPSIL SS-50B", "NIPSIL SS-178B", etc.), Mizusawa Chemical's Mizukasil series ("Mizukasil P-73", "Mizukasil P-526", etc.), Shionogi Carplex series manufactured by Pharmaceutical Co., Ltd. ("Carplex CS-8", etc.), AEROSIL series manufactured by Nippon Aerosil ("AEROSIL 200", "AEROSIL R805", "AEROSIL R972", etc.), Radio manufactured by Showa Chemical Industries, Ltd. Light series ("Radio Light 100", "Radio Light 200", "Radio Light 500", "Radio Light 500R", "Radio Light 500RS", etc.), etc. may be mentioned.

The content of the silica particles (b1) is preferably in the range of 5 to 40 parts by mass based on 100 parts by mass of the resin solid content of the hydroxyl group-containing acrylic resin (A) contained in the main agent (I). , 7 to 30 parts by mass, more preferably 9 to 25 parts by mass.

As the other matting agent, a matting agent known per se can be used, which has been conventionally used for paints. Examples of other types of matting agents include inorganic fine particles other than silica particles, resin beads, and the like.

Examples of other inorganic fine particles include alumina particles, titania particles, zirconia particles, zircon particles, tin oxide particles, magnesia particles, or a mixture thereof.

Examples of the resin beads include PMMA (polymethylmethacrylate) resin beads, MMA-EGDM (ethylene glycol dimethacrylate) copolymer resin beads, nylon resin beads, polytetrafluoroethylene resin beads, polycarbonate resin beads and the like. Be done.

Commercially available products that can be used as the above resin beads include, for example, "Tech Polymer Series (trade name)" manufactured by Sekisui Plastics Co., Ltd., "Dynion Series (trade name)" manufactured by Sumitomo 3M, and "Micro" manufactured by Koyo Chemical Co., Ltd. Flat MA series, (trade name) "and the like.

As for the total content of the matting agent (B), the total mass of the silica particles (b1) and other matting agents is 100 parts by mass of the hydroxyl group-containing acrylic resin (A) resin solid content contained in the main agent (I). As a reference, it can be appropriately adjusted within the range of 5 to 40 parts by mass, and from the viewpoint of the balance between mattness and smoothness, it is more preferably within the range of 7 to 30 parts by mass, and 10 to 25 parts by mass. It is more preferably within the range of the part.

When the content of the matting agent (B) is 5 parts by mass or more, a coating film having suppressed gloss can be formed. Further, when the content of the matting agent (B) is 40 parts by mass or less, a coating film having excellent alkali resistance can be formed.

Further, the matting agent (B) may contain a matting agent other than the silica particles (b1), but in that case, the silica particles (b1) and others may be contained from the viewpoint of gloss stability and alkali resistance. The content ratio of the matting agent is preferably in the range of 60/40 to 100/0, preferably 70/30 to 99/1, and further preferably in the range of 75/25 to 95/5 in terms of mass ratio.

When a matting agent other than the silica particles (b1) is contained, the content is, for example, 20 parts by mass or less based on 100 parts by mass of the total resin solid content of the hydroxyl group-containing acrylic resin (A) contained in the main agent (I). , 1 to 15 parts by mass, more preferably.

From the viewpoint of the balance between matteness and smoothness, the matting agent (B) preferably has an average particle size of 1 to 20 μm, more preferably 2 to 15 μm, and more preferably 3 to 10 μm. More preferred.

In the present specification, the average particle size of the matting agent refers to the D50 value of the particle size distribution measured by the laser scattering method. The D50 value is a particle size in 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 matting agent was measured using a laser diffraction / scattering type particle size distribution measuring device “Microtrack MT3300” (trade name, manufactured by Nikkiso Co., Ltd.). At that time, as a pretreatment, the matting agent is added to a mixed solvent of acetone and isopropyl alcohol and dispersed by applying ultrasonic waves for 1 minute, and the matting agent concentration is a concentration within a predetermined transmittance range set in the apparatus. Adjusted to.

The oil absorption amount of the matting agent (B) is preferably 100 to 400 mL / 100 g, more preferably 100 to 380 mL / 100 g, and further preferably 100 to 360 mL / 100 g from the viewpoint of matting ability.

Here, in the present specification, the oil absorption amount of the matting agent is a value measured according to JIS K5101-13-2: 2004.

Organic solvent (C)
In the present invention, the organic solvent (C) is preferably an organic solvent that does not adversely affect the drying property of the formed coating film and the coating environment, and the resin in the coating composition of the present invention, particularly the matting agent (B). ) Is an organic solvent that can stably disperse and make each resin compatible with each other, and has a solubility in water (20 ° C.) in the range of 5 to 50 g / 100 g and a boiling point of less than 100 to 190 ° C. Contains the organic solvent (c1) of.

In particular, in the present invention, the organic solvent (C) contained in the main agent (I) is the silica particles (b1) from the viewpoint of obtaining the dispersibility of the silica particles and a good matte appearance. ) And the organic solvent (c1) are contained in the range of 70/30 to 10/90. Within the above range, a matte coating composition having very excellent gloss stability can be obtained regardless of the coating environment.

When the organic solvent (c1) is contained within the above range, a matte coating film having excellent drying properties and gloss stability can be obtained.

In the present invention, "solubility in water" means the mass (g) of a solvent that can be dissolved in 100 g of water at a measurement temperature of 20 ° C. Therefore, the value is the same as the mass% of the solvent that can be dissolved in 100% by mass of water.

The type of the organic solvent (c1) is, within the above range, an aliphatic hydrocarbon solvent and / or an alicyclic hydrocarbon solvent, an aromatic hydrocarbon solvent having 9 or more carbon atoms, an ester solvent, and a ketone solvent. , Ether solvent, alcohol solvent, glycol ester solvent and the like can be appropriately selected. In consideration of the influence on the environment and the human body, the total content of toluene and xylene is preferably less than 1% by mass in the total solvent contained in the matte coating composition.

Organic solvent (c1)
Specifically, as such a preferable organic solvent (c1),
Cyclohexanone (also known as anon, boiling point 156 ° C., [8.7 g / 100 g], without hydroxyl group), methoxypropyl acetate (also known as propylene glycol monomethyl ether acetate, boiling point 146 ° C., [19.8 g / 100 g], without hydroxyl group), Ethylene glycol monomethyl ether propionate (boiling point 160 ° C., [18.5g / 100g], no hydroxyl group), ethoxypropyl acetate (boiling point 154 ° C., [9.5g / 100g], no hydroxyl group), 3-methoxybutyl acetate (both boiling point 154 ° C., [9.5g / 100g], no hydroxyl group) Alias: methoxybutyl acetate, boiling point 171.3 ° C, [6.5 g / 100 g], no hydroxyl group), 3-methyl-3-methoxybutyl acetate (also known as 3-methoxy-3-methylbutyl acetate, boiling point 188 ° C,, [6.8 g / 100 g], no hydroxyl group), dipropylene glycol dimethyl ether (also known as dimethylpropylene diglycol, boiling point 171 ° C., [37 g / 100 g], no hydroxyl group), propylene glycol mono-t-butyl ether (boiling point 151 ° C., [ 14.5 g / 100 g], with a hydroxyl group), propylene glycol monobutyl ether (boiling point: 170.2 ° C., [6.4 g / 100 g] with a hydroxyl group) and the like. Of these, ester-based organic solvents are preferable, and 3-methoxybutyl acetate and / or 3-methyl-3-methoxybutyl acetate are particularly preferable.

Here, the numerical value of [] indicates the solubility in water (20 ° C.), and the presence / absence of a hydroxyl group in the molecule of the organic solvent indicates the presence / absence of a hydroxyl group in the () without a hydroxyl group or with a hydroxyl group.

The content of the organic solvent (c1) is in the range of 5 to 55% by mass with respect to the total mass of all the solvents contained in the matte coating composition from the viewpoint of drying property and gloss stability. From the viewpoint of the balance of sagging and drying properties, it is preferably contained in the range of 10 to 30% by mass.

The organic solvent (C) can include an organic solvent other than the organic solvent (c1).
Examples thereof include an organic solvent (c2) having a boiling point of 190 ° C. or higher, and an organic solvent (c3) other than the organic solvent (c1) and the organic solvent (c2).

The organic solvent (c2) is an organic solvent having a boiling point of 190 ° C. or higher. The gloss stability may be improved by using an organic solvent (c2) having a relatively high boiling point in combination.

Specifically, propylene glycol diacetate (boiling point 190 ° C.), 1,4-butanediol diacetate (boiling point 232 ° C.), 1,3-butylene glycol diacetate (boiling point 232 ° C.), diethylene glycol monoethyl ether acetate (boiling point). 217 ° C.), Dipropylene glycol methyl ether (boiling point 190 ° C.), Diethylene glycol monoethyl ether (boiling point 202 ° C.), Dipropylene glycol n-propyl ether (boiling point 212 ° C.), Dipropylene glycol n-butyl ether (boiling point 229 ° C.), Tripropylene glycol methyl ether (boiling point 242 ° C.), diethylene glycol monobutyl ether (boiling point 231 ° C.), "DBE" (mixed solvent of dimethyl glutarate, dimethyl succinate and dimethyl adipate, manufactured by DowDuPont) (boiling point 196-225 ° C.) , Solvent # 150 (boiling point 190-210 ° C., manufactured by Sankyo Chemical Co., Ltd.), "Swazole 1500" (boiling point, 190-210 ° C. [initial distillation 180-185 ° C.] manufactured by Cosmo Oil Co., Ltd.) and the like can be mentioned.

The organic solvent (c2) is less than 30% by mass, preferably 0.5 to 20% by mass, based on the total mass of all the solvents contained in the matte coating composition, from the viewpoint of drying property and gloss stability. It is within the range, particularly preferably within the range of 1 to 10% by mass.

Other organic solvents (c3)
Examples of the organic solvent other than the organic solvent (c1) and the organic solvent (c2) include aliphatic hydrocarbon solvents such as hexane and heptane; methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, and the like. Ester solvents such as ethyl acetate, ethyl-3-ethoxypropionate, cyclohexyl acetate, normal butyl propionate (also known as normal butyl propionate), ethylene glycol monoisobutyl ether acetate; ethylene glycol monoethyl ether (also known as cellosolve). ), Isopropyl glycol (also known as ethylene glycol monoisopropyl ether), ethylene glycol monobutyl ether, propylene glycol-n-propyl ether and other ether solvents; ethanol, propanol, 2-ethylhexyl alcohol, 3-methoxy-3-methylbutanol, etc. Alcohol-based solvents; Ketone-based solvents such as methyl ethyl ketone, methyl pentyl ketone, and methyl isopentyl ketone; aromatic hydrocarbon-based solvents such as "Swazole 310" and "Swazole 1000" (both manufactured by Cosmo Petroleum Co., Ltd.); Examples thereof include group hydrocarbon solvents and amide solvents.

Among them, it is preferable to contain at least one selected from butyl acetate, isobutyl acetate, ethyl acetate and ethyl-3-ethoxypropionate from the viewpoint of improving gloss stability and compatibility with other components at low cost.

The organic solvent (c3) is contained in an amount of 95% by mass or less, preferably 50 to 90% by mass, based on the total mass of all the solvents contained in the matte coating composition from the viewpoint of drying property and gloss stability. Is preferable.

Generally, an organic solvent having a boiling point of less than 100 ° C. under normal pressure is called a low boiling point solvent, a solvent having a boiling point of 100 ° C. to 150 ° C. is called a medium boiling point solvent, and a solvent having a boiling point of more than 150 ° C. is called a high boiling point solvent.

The present invention comprises the organic solvent (c1) and silica particles (b1) having a medium to high boiling point and a solubility (20 ° C.) in water within a specific range in the main agent (I) in a specific ratio. Excellent compatibility with other components, less variation in the coated solid content on the entire coated surface during film formation, and contributing to the dispersibility of silica particles (b1), resulting in gloss variation depending on the coating conditions. It is considered that a coating film having a good and stable matte appearance can be obtained.

Further, by containing a specific amount of an organic solvent (c1) having a medium to high boiling point and a solubility (20 ° C.) in water within a specific range, dryness and gloss stability are particularly suitable in the field of automobile repair applications and the like. A coating film having excellent properties can be obtained.

The main agent (I) may be a resin other than the hydroxyl group-containing acrylic resin (A), a diluent, a curing catalyst, a coloring pigment, a brilliant pigment, an extender pigment, a pigment dispersant, and a rheology control agent (E), if necessary. ), UV absorbers, light stabilizers, plasticizers and other paint additives commonly used in the field of paints.

Examples of the resin other than the hydroxyl group-containing acrylic resin (A) include silicone resin, urethane resin, fluororesin, epoxy resin, polyester resin, alkyd resin and the like, mixed resins or modified resins thereof, for example, acrylic modified polyester resin and acrylic silicone. Examples thereof include resins, acrylic-modified epoxy resins and epoxy ester resins. Further, these may have a hydroxyl group. Further, an acrylic resin containing no hydroxyl group can also be mentioned. These may be used alone or in combination of two or more.

When the main agent (I) contains other resin, the content thereof is, for example, 30 parts by mass based on 100 parts by mass of the total resin solid content of the hydroxyl group-containing acrylic resin (A) contained in the main agent (I). Less than, preferably in the range of 1 to 10 parts by mass, and more preferably in the range of 1.5 to 8 parts by mass.

Rheology control agent (E)
By blending the rheology control agent (E), thixotropy can be imparted to the matte paint composition, and as a result, when high shear stress is applied such as during spray painting, the viscosity is sufficiently sufficient. On the other hand, when low shear stress is applied after coating on the surface to be coated, it is possible to increase the apparent viscosity. It becomes. As a result, it is possible to prevent the occurrence of coating film defects such as sagging and repelling when painting on a vertical surface to be coated or when baking on that portion, and a coating film having a good matte appearance is formed. The effect of being able to do it is obtained. Examples of such rheology control agent (E) include crosslinked polymer fine particles and polyurea compounds.

The crosslinked polymer fine particles are internally crosslinked particulate polymers that are hardly or completely soluble in organic solvents and the like and can be stably dispersed in the present composition.

As the crosslinked polymer fine particles, an aqueous emulsion or an intramolecularly crosslinked fine particle polymer obtained by an aqueous suspension polymerization method or a non-aqueous dispersion polymerization method, which is known per se, can be used.

Of these, the aqueous emulsion or the fine particle polymer having an intramolecular crosslinked structure obtained by the aqueous suspension polymerization method is separated by physical or chemical means such as evaporation or co-boiling of water or precipitation or aggregation of the polymer (particles). By doing so, it can be formed into a solid substance, or when such physical or chemical means are applied, the medium of the target crosslinked polymer fine particles is directly replaced from water with another resin, an organic solvent or the like. You may do so.

Examples of the crosslinked polymer fine particles include a polymerizable monomer having at least two radically polymerizable unsaturated groups in the molecule and other radically polymerizable non-polymerizable monomers as disclosed in JP-A-3-66770. Crosslinked polymer fine particles obtained by emulsion polymerization of a saturated monomer in the presence of a reactive emulsifier containing an allyl radical in the molecule can be preferably used.

These crosslinkable polymer fine particles are substantially non-swellable and non-fusing even in an organic solvent having a high crosslink density and a large polymer dissolving power such as toluene and ethyl acetate, and contain an organic solvent. When added to the present coating composition, a solution (dispersion liquid) having a high resin content, that is, a high solid content can be obtained without increasing the viscosity of the present coating composition.

The crosslinked polymer fine particles generally have an average particle size in the range of about 0.01 to about 2 μm, particularly preferably 0.05 to 0.5 μm, and fine particles having a particle size in this range prevent sagging. Provided is a coating film having an effect and a stable matte appearance. Here, the average particle size of the crosslinked polymer fine particles is appropriately determined by a conventional method using a [submicron particle size distribution measuring device "COOLTER N4 type" (manufactured by Beckman Coulter)] (hereinafter, the same). It is a volume-based value obtained by measuring at 20 ° C. after diluting with, and performing monodisperse mode analysis.

Further, as the rheology control agent (E), for example, 3 to 20, preferably 5 to 14, and more preferably 8 to 12 carbon atoms as described in JP-A-7-81099 are used. It is also possible to use a polyurea compound in the form of solid particles composed of a reaction product of an isocyanurate trimer obtained from a diisocyanate compound having an amine compound having at least one primary amino group.

When the rheology control agent (E) is contained in the main agent (I), the content thereof is, for example, based on 100 parts by mass of the total resin solid content of the hydroxyl group-containing acrylic resin (A) contained in the main agent (I). It is preferably in the range of 1 to 10 parts by mass, and more preferably in the range of 1.5 to 8 parts by mass.

Curing catalyst Examples of the curing catalyst include tin octylate, dibutyltin diacetate, dibutyltin di (2-ethylhexanoate), dibutyltin dilaurate, dioctyltin diacetate, and dioctyltindi (2-ethylhexanoate). ), Dibutyltin oxide, dibutyltin sulfate, dioctyltin oxide, dibutyltin fatty acid salt, lead 2-ethylhexanoate, zinc octylate, zinc naphthenate, zinc fatty acids, bismuth octanate, bismuth 2-ethylhexanoate, olein Organic metal compounds such as bismuth acid, bismuth neodecanoate, bismuth versaticate, bismuth naphthenate, cobalt naphthenate, calcium octylate, copper naphthenate, tetra (2-ethylhexyl) titanate; tertiary amines and the like 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 content of the curing catalyst ranges from 0.05 to 10 parts by mass based on 100 parts by mass of the resin solid content in the matte coating composition. It is preferably in the range of 0.1 to 5 parts by mass, more preferably in the range of 0.2 to 3 parts by mass.

Examples of the coloring pigment include titanium oxide, zinc oxide, carbon black, molybdenum red, prusian blue, cobalt blue, azo pigment, phthalocyanine pigment, quinacridone pigment, isoindolin pigment, slene pigment, perylene pigment, and the like. Examples thereof include dioxazine pigments and diketopyrrolopyrrole pigments.

Glittering pigments include aluminum (including vaporized aluminum), copper, zinc, brass, nickel, glass flakes, aluminum oxide, mica, titanium oxide and / or aluminum oxide coated with iron oxide, titanium oxide and / or oxidation. Examples thereof include a mica covered with iron.

Examples of the extender pigment include talc, clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, alumina white and the like.

The pigments 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 content of the pigment may be an amount that does not impair the transparency of the obtained coating film. Preferably, for example, it is usually in the range of 0.1 to 20 parts by mass, preferably in the range of 0.3 to 10 parts by mass, based on 100 parts by mass of the resin solid content in the matte coating composition. It is more preferable, and it is further preferable that it is in the range of 0.5 to 5 parts by mass.

When the matte coating composition of the present invention is used as a coloring paint and contains a pigment, the content of the pigment is based on 100 parts by mass of the resin solid content in the matte coating composition. Usually, it is preferably in the range of 1 to 200 parts by mass, more preferably in the range of 2 to 100 parts by mass, and further preferably in 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-based absorbents, triazine-based absorbents, salicylic acid derivative-based absorbents, and benzophenone-based absorbents. 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 content of the ultraviolet absorber is 0.1 to 10% by mass based on 100 parts by mass of the resin solid content in the matte coating composition. It is preferably in the range of parts, more preferably in the range of 0.2 to 5 parts by mass, and even more preferably in the range of 0.3 to 2 parts by mass.

As the light stabilizer, conventionally known ones can be used, and examples thereof include hindered amine-based light stabilizers.

When the matte coating composition of the present invention contains a light stabilizer, the content of the light stabilizer is 0.1 to 10% by mass based on 100 parts by mass of the resin solid content in the matte coating composition. It is preferably in the range of parts, more preferably in the range of 0.2 to 5 parts by mass, and even more preferably in the range of 0.3 to 2 parts by mass.
Hardener (II)
The curing agent (II) used in the present invention contains a curing agent component, and the curing agent component contains a polyisocyanate compound (D).

Polyisocyanate compound (D)
The polyisocyanate compound (D) is a compound having at least two isocyanate groups in one molecule, and is, for example, an aliphatic polyisocyanate, an alicyclic polyisocyanate, an aromatic aliphatic polyisocyanate, an aromatic polyisocyanate, or the like. Examples thereof include derivatives of polyisocyanate.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylenediocyanate, 2,3-butylenediocyanate, and 1,3. An aliphatic diisocyanate such as butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, diimmerate diisocyanate, methyl 2,6-diisocyanatohexanoate (common name: lysine diisocyanate); 2 , 6-Diisocyanatohexanoic acid 2-isocyanatoethyl, 1,6-diisocyanato-3-isocyanatomethylhexane, 1,4,8-triisocyanatooctane, 1,6,11-triisocyanatoundecane, 1, , 8-Diisocyanato-4-isocyanatomethyloctane, 1,3,6-triisocyanatohexane, 2,5,7-trimethyl-1,8-diisocyanato-5-isocyanatomethyloctane and other aliphatic triisocyanates, etc. Can be mentioned.

Examples of the alicyclic polyisocyanate include 1,3-cyclopentenediisocyanate, 1,4-cyclohexanediisocyanate, 1,3-cyclohexanediisocyanate, and 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate (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) Alicyclic diisocyanates such as methyl) cyclohexane (conventional name: hydrogenated xylylene diisocyanate) or a mixture thereof, methylenebis (4,1-cyclohexanediyl) diisocyanate (conventional name: hydrogenated MDI), norbornan 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-isocyanatoethyl) -2-isocyanatomethyl-2- (3-Isocyanatopropyl) -bicyclo (2.2.1) -heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl) -bicyclo (2.2) . 1) An alicyclic triisocyanate such as heptane can be mentioned.

Examples of the aromatic aliphatic polyisocyanate include methylenebis (4,1-phenylene) diisocyanate (trivial 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 (trivial name: tetramethylxylylene diisocyanate) or a mixture thereof; 1,3 , 5-Aromatic aliphatic triisocyanate such as triisocyanatomethylbenzene and the like can be mentioned.

Examples of the aromatic polyisocyanate include m-phenylenedi isocyanate, p-phenylenedi isocyanate, 4,4'-diphenyldiisocyanate, 1,5-naphthalenedi isocyanate, and 2,4-tolylene diisocyanate (common name: 2,4-). TDI) or 2,6-tolylene diisocyanate (common name: 2,6-TDI) or a mixture 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 other aromatic triisocyanates; 4,4'-diphenylmethane-2,2' , 5,5'-Aromatic tetraisocyanate such as tetraisocyanate and the like can be mentioned.

Examples of the polyisocyanate derivative include the above-mentioned polyisocyanate dimer, trimmer, biuret, allophanate, uretdione, uretoimine, isocyanurate, oxadiazine trione, and polymethylene polyphenyl polyisocyanate (crude MDI, polypeptide MDI). , Crude TDI and the like.

The polyisocyanate and its derivatives may be used alone or in combination of two or more. Further, among these polyisocyanates, aliphatic diisocyanates and their derivatives can be preferably used from the viewpoint of weather resistance and the like.
Further, as the polyisocyanate compound (D), the polyisocyanate compound and its derivative 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 mixed with an excess of isocyanate groups. Prepolymers that have been reacted under conditions may be used. Examples of the compound capable of reacting with the polyisocyanate include polyhydric alcohols, low molecular weight polyester resins, amines, water and the like.

The polyisocyanate compound (D) can be used alone or in combination of two or more.

When two or more polyisocyanate compounds are used for the curing agent (II), the isocyanate group content in the curing agent (II) is 5% by mass or more on average, and further 8 to 8 to 8 in terms of storage stability and weather resistance. It is preferable that the blending amount is adjusted so as to be within the range of 25% by mass.

The content of the polyisocyanate compound (D) in the matte coating composition is the equivalent ratio (NCO / OH) of the isocyanate group of the polyisocyanate compound (D) to the hydroxyl group of the hydroxyl group-containing acrylic resin (A). Generally, the amount can be appropriately adjusted in the range of 0.5 to 5.0, but from the viewpoint of curability and weather resistance, the range is preferably in the range of 1.1 to 3.0, and further 1 It is more preferable that the amount is in the range of 2 to 2.0. When the equivalent ratio (NCO / OH) is in the above preferable range, there is an advantage that the curing reactivity of the matte coating composition can be ensured in a good range. The above equivalent ratios are all converted into solid content.

The curing agent (II) used in the present invention may contain an organic solvent (C).

As the organic solvent (C), those listed in the above-mentioned organic solvent (C) section can be preferably used.

The organic solvent contained in the curing agent (II) is preferably an organic solvent having no hydroxyl group, and is mixed with the main agent (I) from the viewpoint of adjusting the finish such as drying property and obtaining a desired matte appearance. From the viewpoint of properties, at least one organic solvent selected from ester-based, glycol-based, ketone-based and hydrocarbon-based solvents having no hydroxyl group is preferable. Since the curing agent is adjusted with the organic solvent having no hydroxyl group, the balance between the storage stability and the miscibility between the hydroxyl group-containing acrylic resin (A) and the curing agent is excellent, which is particularly preferable.

The solid content of the curing agent (II) can be appropriately adjusted in the range of 10 to 100% by mass, preferably in the range of 30 to 99% by mass.

Further, the curing agent (II) includes additives for paints, for example, surface conditioners, defoaming agents, curing catalysts, ultraviolet absorbers, to the extent that the storability and drying property of the curing agent (II) are not impaired. A light stabilizer, a desiccant, and the like can be added as needed. As the curing component, other cross-linking components capable of cross-linking with the hydroxyl group of the hydroxyl group-containing acrylic resin (A) other than the polyisocyanate compound may be contained, but from the viewpoint of low temperature curability, the polyisocyanate compound (D) may be contained. Is preferably 70 parts by mass or more, and particularly preferably 80 to 100 parts by mass with respect to 100 parts by mass of the resin solid content in the curing agent.

Adjustment of Matte Paint Composition The coating film obtained by applying the matte paint composition of the present invention has a matte property.

As used herein, the term "matte" means that the 60 ° mirror surface gloss value of the formed coating film measured based on JIS K 5600-4-7: 1999 is less than 75, preferably less than 70, and more preferably 65. It means that it is less than.

The matte coating composition of the present invention is preferably an organic solvent type coating composition. In the present specification, the organic solvent type coating composition is a coating material that does not substantially contain water as a solvent.

The matte coating composition of the present invention uses a diluent as necessary at the time of coating, and has a solid content of 15% by mass or more, particularly preferably in the range of 35 to 60% by mass, and a viscosity of 5 to 30. It is preferable to adjust the temperature within the range of seconds / Ford cup # 4/20 ° C. from the viewpoint of painting workability and reduction of the amount of organic solvent discharged.

As the diluent, the organic solvent mentioned in the item of the organic solvent (C) can be mentioned, and the solubility (20 ° C.) of the organic solvent in water is in the range of 5 to 50 g / 100 g and the boiling point is 100 to 190. It contains an organic solvent (c1) below ° C., and the content of the organic solvent (c1) is within the range of 5 to 55% by mass with respect to the total mass of all the solvents contained in the matte coating composition. It is desirable to adjust so that

In the matte coating composition of the present invention, from the viewpoint of storage stability, the main agent (I) containing the hydroxyl group-containing acrylic resin (A) and the matting agent (B) and the curing agent (II) are separated. It is a two-component paint, and it is preferable to mix and use both immediately before use.

Method for Forming a Coating Film The object to be coated to which the matte coating composition of the present invention is applied includes, but is not limited to, an object to be coated using a metal, plastic or the like as a base material. The object may be painted. Further, the object to be coated may be a molded product containing the above-mentioned base material. Examples of the use of these objects to be coated include automobile vehicles such as automobiles and motorcycles or their parts, large vehicles such as trucks, buses, construction machinery or railway vehicles or their parts, and the like.

Further, the surface of the above-mentioned metal base material, a base material such as plastic, or a molded product thereof may be degreased and / or surface-treated.

Further, the object to be coated may be a coating film (old coating film) already formed on the surface to be coated or a damaged portion of the coated body.

The coating method of the matte coating composition of the present invention is not particularly limited, and examples thereof include coating methods such as air spray coating, airless spray coating, rotary atomization coating, and curtain coat coating. A wet coating can be formed by the method. In these painting methods, electrostatic electricity may be applied if necessary. Of these, air spray coating or rotary atomization coating is particularly preferable.

Further, in the case of performing air spray coating, airless spray coating and rotary atomization coating, the viscosity of the coating composition of the present invention is set to a viscosity range suitable for the coating, usually Ford Cup No. It is preferable to appropriately adjust the viscosity of the four viscometers at 20 ° C. for about 15 to 60 seconds using a solvent.

The drying method of the matte coating composition of the present invention is not particularly limited, and a coating film can be obtained by normal temperature drying as a drying method, but heat drying or forced drying is performed depending on the coating environment and the like. However, there is no particular problem. In the case of heat drying, it can be dried under relatively mild drying conditions, in the range of 25 to 80 ° C., preferably 40 to 60 ° C. The heat-drying time is not particularly limited, and is preferably in the range of, for example, 10 to 60 minutes, preferably 15 to 30 minutes.

If necessary, air drying may be used using a blower or the like. In normal temperature drying, a coating film can be obtained by drying in an environment of, for example, 5 to 45 ° C. The relative humidity (hereinafter sometimes abbreviated as RH) at the time of painting is preferably 80% or less, particularly 70% or less.

In the case of the forced drying, from the viewpoint of finishability, it may be set (standing) at room temperature for 2 to 30 minutes in advance before heating and drying.

The film thickness can be appropriately adjusted according to the condition of the surface to be coated, but generally, the dry film thickness is preferably in the range of 5 to 150 μm, 10 to 100 μm, and particularly 7 to 60 μm.

Since the matte coating composition of the present invention is extremely excellent in drying property and gloss stability, for example,
By applying the matte coating composition of the present invention to the object to be coated to form a coating film on the outermost surface, the design of the object to be coated can be utilized to give a matte appearance. In particular, since this paint is a paint composition that is excellent in drying property, does not contain toluene or xylene, and is friendly to the human body and the environment, it can be particularly preferably used as a paint for repairing automobiles.

Further, since it can be dried even at room temperature or mild drying conditions, it can be suitably used as a paint for large vehicles.
Repair Painting Method for Painted Body This paint can be applied particularly to the old paint film or the damaged part of the painted body with the matte paint composition, and can be suitably applied as a repair painting method for the painted body.

For example, the following methods I and II can be preferably used.

Method I
Step (1) of applying a primer surfacer to a damaged portion of an old coating film or a coated body to form a base-treated coating film (I).
Step (2) of coating the coloring base coating film composition on the undercoat coating film to form the coloring base coating film (II).
The step (3), in which the clear coating composition is applied onto the colored base coating film obtained in the step (2) and dried to form the clear coating film (III).
A method for repairing and painting a painted body, wherein the clear paint composition is the matte paint composition of the present invention.

Method II
A step (1) of applying a primer surfacer to a damaged portion of a coated body to form a base-treated coating film (I).
Step (2) of coating the coloring base coating film composition on the undercoat coating film to form the coloring base coating film (II).
The step (3), in which the first clear coating film composition (CC1) is coated on the colored base coating film obtained in the step (2) and dried to form the first clear coating film (III).
A coated body comprising a step (4) of coating a second clear coating film composition (CC2) on the first clear coating film obtained in the step (3) to form a second clear coating film (IV). It is a repair painting method of
A repair coating method for a coated body, wherein the second clear coating composition (CC2) is the matte coating composition of the present invention.

In the method I or the method II, the old coating film or the coated body can be a multi-layer coating film containing a known matte coating film, preferably a matte clear coating film.

In the above methods I and II, the old coating material or the coating body as the object to be coated is a coating film or a coated body in which a cured undercoat coating film is formed by an electrodeposition paint on a metal substrate; the cured undercoating material. A coating or a coating body on which a cured intermediate coating film is formed on a film; a coating film or a coating body on which an uncured intermediate coating film is formed on the cured undercoat coating film; a polyolefin on a plastic substrate. A coating film or a coating body on which a cured undercoat coating film is formed by a primer paint containing a resin; a coating film or a coating body on which an uncured undercoat coating film is formed by a primer paint containing a polyolefin resin on a plastic substrate. And so on.

In addition, the area around the damaged part of the old paint film or painted body to be painted is cleaned and sanded in advance with sandpaper, and if necessary, the surface to be coated is preliminarily grounded with a putty composition or the like. Can be processed.

By applying a primer surfacer or other surface treatment agent to form a surface treatment film, it is possible to protect the exposed or uneven surface of the damaged part of the coated body and improve the adhesion to the colored base coating film described later. can.

As a method for painting the primer surfacer, a conventionally known method such as spray painting can be used for painting. Further, when the putty composition is applied, it can be applied using, for example, a spatula or the like. Before painting or filling the surface treatment agent, cleaning, sanding with sandpaper, or the like may be performed in advance around the damaged portion of the coated body.

The putty or primer surfacer may be dried, and examples of the drying method include room temperature drying or forced drying, and the inside of the coating film can be cured by this drying step. In the case of room temperature drying, specifically, it can be allowed to stand at room temperature for 5 hours or more, or in the case of forced drying, it can be heated at 40 to 120 ° C. for 5 to 60 minutes. In the case of the forced drying, from the viewpoint of finishability, it can be set (standing) at room temperature for 2 to 30 minutes in advance before heat curing. For drying, for example, a blower or the like may be used.

The film thickness of the obtained primer surfacer is usually preferably 8 to 500 μm and further 10 to 150 μm in terms of dry film thickness, considering that polishing will be performed later.

As a polishing method, for example, water resistant paper, sandpaper, or the like can be used. Further, water-resistant paper may be used for water polishing, and a compound for rough polishing and a compound for finish polishing may be sequentially polished.

Further, in the above methods I and II, one or more kinds of coating compositions may be used as the coloring base coating composition, and one or more layers of the coloring base coating film may be formed. Further, after coating the coloring base coating composition, in order to promote the volatilization of the solvent in the coloring base coating composition without curing the coating film, for example, preheating at 40 to 90 ° C. for about 3 to 30 minutes. May be done.

Coloring-based paint composition As the coloring-based paint composition, for example, a water-based paint or an organic solvent-based paint can be used. Of these, water-based paints are preferable from the viewpoint of reducing the environmental load.

In the present specification, the water-based paint generally means a paint in which a coating film-forming resin, a pigment or the like is dispersed and / or dissolved in water or a medium containing water as a main component (water-based medium).

As the coloring base coating composition, for example, when the object to be coated is an automobile body, a known one that is usually used in painting an automobile body can be used.

Specifically, the coloring base coating composition includes a substrate resin such as an acrylic resin, a polyester resin, an alkyd resin, a urethane resin, and an epoxy resin having a crosslinkable functional group such as a carboxyl group and a hydroxyl group, and a melamine resin and a urea resin. Amino resin such as, a cross-linking agent such as a polyisocyanate compound which may be blocked, and a paint made by dissolving or dispersing in water or an organic solvent together with a pigment, a thickener and other optional components. Can be used. Among them, at least one selected from the group consisting of a hydroxyl group-containing polyester resin and a hydroxyl group-containing acrylic resin is used as the substrate resin, and the curing agent is selected from the group consisting of a melamine resin and a polyisocyanate compound which may be blocked. A thermosetting water-based paint using at least one of these can be preferably used.

As the above-mentioned pigment, a coloring pigment, an extender pigment, and a brilliant pigment can be used alone or in combination of two or more.

Examples of the coloring pigments include titanium oxide, zinc flower, carbon black (including conductive carbon black), molybdenum red, prusian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, and isoindolin pigments. Examples thereof include slene-based pigments, perylene-based pigments, dioxazine-based pigments, and diketopyrrolopyrrole-based pigments.

Examples of the extender pigment include talc, clay, kaolin, barita, barium sulfate, barium carbonate, calcium carbonate, silica, alumina white and the like.

Glittering pigments include, for example, non-leafing or leaving type aluminum (including vaporized aluminum), copper, zinc, brass, nickel, glass flakes, graphite flakes, aluminum oxide, mica, titanium oxide or iron oxide. Examples thereof include a mica coated with aluminum oxide, titanium oxide or iron oxide. Among them, it is preferable to use at least one bright pigment selected from aluminum, mica, aluminum oxide coated with titanium oxide or iron oxide, and mica coated with titanium oxide or iron oxide. These may be used alone or in combination of two or more.

The solid content of the coloring base coating composition can be usually 60% by mass or less, and the solid content at the time of coating can be usually 10 to 50% by mass.

Additives that can be added to the colored base paint composition include UV absorbers, light stabilizers, antioxidants, surface modifiers, defoamers, etc., including those exemplified for the paint composition of the present invention. Common paint additives can be used.

The method of applying the coloring base coating composition is not particularly limited, and for example, air spray, airless spray, rotary atomization, brush, roller, hand gun, universal gun, immersion, roll coater, curtain flow coater, roller curtain coater, etc. Examples thereof include a die coater, which can be appropriately selected depending on the intended use of the object to be coated, and may be applied a plurality of times.

The colored base coating composition may be dried after being coated, and examples thereof include normal temperature drying and forced drying. In the case of normal temperature drying, specifically, it can be allowed to stand at room temperature (for example, less than 10 to 40 ° C.) for 5 hours or more, or in the case of forced drying, it can be heated at 40 to 120 ° C. for 5 to 60 minutes. .. In the case of the forced drying, from the viewpoint of finishability, it can be set (standing) at room temperature for 2 to 30 minutes in advance before heat curing. For drying, for example, a blower or the like may be used.

From the viewpoint of shortening the process, it is preferable to apply the clear coating composition (CC1) and / or the matte coating composition of the present invention in an uncured state.

Clear paint composition (CC1)
As the clear paint composition (CC1), for example, when the object to be coated is an automobile body, a known one that is usually used in painting an automobile body can be used.

Specifically, the clear paint composition (CC1) contains a base resin such as an acrylic resin, a polyester resin and a urethane resin having a crosslinkable functional group such as a carboxyl group and a hydroxyl group, and an amino resin such as a melamine resin and a urea resin. , A cross-linking agent such as a polyisocyanate compound which may be blocked can be used as a paint by dissolving or dispersing it in an organic solvent together with other components of the option. Among them, at least one selected from the group consisting of a hydroxyl group-containing polyester resin and a hydroxyl group-containing acrylic resin is used as the substrate resin, and the curing agent is selected from the group consisting of a melamine resin and a polyisocyanate compound which may be blocked. A thermosetting solvent paint using at least one of these can be preferably used.

The solid content of the clear coating composition (CC1) can be usually 60% by mass or less, and the solid content at the time of coating can be usually 30 to 50% by mass.

Optional components that can be added to the clear paint composition (CC1) include pigments such as color pigments, extender pigments, and brilliant pigments, including those exemplified for the paint composition of the present invention, and ultraviolet absorbers. , Light stabilizers, antioxidants, surface conditioners, defoamers, and other general paint additives can be used.

Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples. However,
The present invention is not limited thereto. In each example, "part" and "%" are
Unless otherwise specified, it is based on mass. The film thickness of the coating film is based on the cured coating film. Furthermore, the blending amount in the table is the solid content mass.
Production Example 1 of Production of Hydroxyl Group-Containing Acrylic Resin (A)
45 parts of butyl acetate [boiling point 126 ° C, water solubility (20 ° C) 0.7 g / 100 g] as an organic solvent during production in a four-necked flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet. Was charged, and the temperature was raised to 120 ° C. under ventilation of nitrogen gas. After reaching 120 ° C., the aeration of nitrogen gas was stopped, and a monomer mixture having a composition of the monomers and the polymerization initiator shown in Table 1 below was added dropwise over 4 hours.
Then, after aging at 120 ° C. with aeration of nitrogen gas for 1 hour, a mixture of 0.5 part of 2,2'-azobisisobutyronitrile and 5 parts of butyl acetate was added dropwise over 1 hour, and then The mixture was aged at about 120 ° C. for 1 hour to obtain a hydroxyl group-containing acrylic resin (A1-1) solution diluted to a solid content of 50% with the same organic solvent as in the production. The hydroxyl value based on the solid content of the obtained acrylic resin was 82 mgKOH / g, the weight average molecular weight was about 17,000, and the glass transition temperature was 62 ° C.

Production Examples 2-4
Hydroxyl group-containing acrylic resins (A1-2) to (A1-4) were produced in the same manner as in Production Example 1 except that the monomer composition and the organic solvent at the time of production are shown in Table 1 below. Table 1 shows the hydroxyl value, weight average molecular weight, and glass transition temperature of each of the obtained hydroxyl group-containing acrylic resins based on the solid content.

Production Example 5 Production of crosslinked polymer fine particles In a reaction vessel equipped with a thermostat, a thermostat, a stirrer, a reflux condenser and a dropping device, 355 parts of deionized water and "Latemuru S-120A" (trade name, manufactured by Kao Co., Ltd.) , A sulfosuccinic acid-based allyl group-containing anionic reactive emulsifier, 50% aqueous solution), and the temperature was raised to 90 ° C. with stirring. In addition to this, "VA-086", which is a water-soluble azoamide polymerization initiator (trade name, manufactured by Wako Pure Chemical Industries, Ltd., 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) -propionamide) ]) 20% of the aqueous solution prepared by dissolving 1.25 parts in 50 parts of deionized water was added. After 15 minutes, 5% of the monomer mixture consisting of 30 parts of styrene, 40 parts of methyl methacrylate, 15 parts of n-butyl acrylate, 5 parts of 2-hydroxyethyl acrylate and 10 parts of 1,6-hexanediol diacrylate was added. Then, after further stirring for 30 minutes, the remaining monomer mixture and the polymerization initiator aqueous solution were started to be added dropwise. The dropping of the monomer mixture was carried out over 3 hours, and the dropping of the aqueous polymerization initiator solution was carried out over 3.5 hours, during which the polymerization temperature was maintained at 90 ° C. After the completion of dropping the polymerization initiator aqueous solution, the mixture was heated for 30 minutes, kept at 90 ° C., cooled to room temperature, and taken out using a filter cloth to obtain an aqueous dispersion of polymer fine particles having a solid content of 20%. This aqueous dispersion was dried on a stainless steel vat in an electric hot air dryer at 60 ° C. to obtain crosslinked polymer fine particles (P1) as a solid resin. The average particle size of the obtained crosslinked polymer fine particles (P1) was 90 nm, the acid value was less than 0.5 mgKOH / g, and the hydroxyl value was 24 mgKOH / g.

Production Example 6 Curing agent (II-1)
100 parts of "Sumijour N3300" (trade name, manufactured by Sumika Covestro Urethane, isocyanurate of hexamethylene diisocyanate, solid content 100%, NCO content 21.8% by mass), especially containing organic solvent Those that did not were used as they were as the curing agent (II-1).

Production Examples 7 and 8
The organic solvent of Production Example 4 was shown in Table 2, and the mixture was stirred for 30 minutes to prepare a curing agent (II-2) and a curing agent (II-3) having a solid content of 40%.

(Example 1) Matte paint composition No. Preparation of No. 1 As the main agent (I), 200 parts (solid content 100 parts) of the hydroxyl group-containing acrylic resin (A-1) obtained in Production Example 1 and 20 parts (solid content 20 parts) of the matting agent (B-1) were used. , Organic solvent (c1) -1 35 parts, organic solvent (c3) -1 15 parts and other components shown in Table 3-1 are stirred and mixed using a rotary blade type stirrer to adjust the main agent (I). bottom. Then, the curing agent (II-1) was mixed with the main agent in an amount of NCO / OH of 1.3 and mixed to prepare a matte coating composition (1). At this time, the Ford Cup No. at 20 ° C. The viscosity according to 4 was 15 seconds.

(Making a painted plate)
The central part of the object to be coated 1 is polished with # 240 paper, and the "COODE filler dark gray (L20) base" (trade name, manufactured by Kansai Paint Co., Ltd., acrylic) is used as a primer surfacer on a painted plate with a partially exposed steel plate. A polyol and a polyisocyanate-based environmentally friendly organic solvent high solid primer surfacer paint) were spray-coated so as to have a dry film thickness of 60 to 70 μm, dried at 60 ° C. for 30 minutes, and then water-polished with # 400 paper. On top of that, "Retan WB Eco EV 400 Deep Black" (Kansai Paint Co., Ltd., colored base coat paint for water-based repair) is spray-painted so that the dry film thickness is 15 μm, and after standing at room temperature for 10 minutes, it is 60 ° C. Then, the matte coating composition (1) obtained in Example 1 was coated with the coating conditions and film thicknesses shown in Tables 4-1 and 4-2 and Table 4-3 at 60 ° C. It was heated and dried for 30 minutes to prepare a coated plate for gloss stability and alkali resistance test.

The "painting conditions" in Tables 4-1 and 4-2 and 4-3 are as follows. Painting condition 1 is room temperature 23 ° C. and relative humidity (RH) 60%.
The painting condition 2 is a room temperature of 30 ° C. and RH 75% (assuming summer), and the painting condition 3 is a room temperature of 5 ° C. and RH 50% (assuming winter).

(Preparation of test plate for sagging resistance evaluation)
"Electron GT-10" (manufactured by Kansai Paint Co., Ltd., trade name, thermosetting epoxy resin-based cation) on a dull steel plate with a size of 11 cm x 45 cm and a thickness of 0.8 mm that has been subjected to zinc phosphate chemical conversion treatment. (Epoxy coating) is electrodeposited so that the cured film thickness is 20 μm, heated at 170 ° C for 30 minutes to cure, and then "TP-65-2" (manufactured by Kansai Paint Co., Ltd., trade name, polyester) is cured. (Melamine resin-based automobile intermediate coating paint) was air-spray coated so as to have a cured film thickness of 35 μm, and heat-cured at 140 ° C. for 30 minutes to obtain a test object to be coated. Next, 21 punch holes having a diameter of 5 mm were provided in a row at 2 cm intervals in a portion 3 cm from the long end of the test object, and then the temperature was applied to the test object. Under coating booth conditions (booth condition 3) at 19 ° C and 51% relative humidity, the water-based base coat paint composition "Retan WB Eco EV 400 Deep Black" (trade name, manufactured by Kansai Paint Co., Ltd., acrylic urethane resin-based water-based repair coloring base A coating composition (black coating color) was applied to a film thickness of 15 μm, left at room temperature for 10 minutes, preheated at 60 ° C. for 3 minutes, and then on the uncured coating film, Example. The coating composition (1) obtained in 1 was coated with a film thickness gradient so as to obtain a film thickness of approximately 30 μm to 60 μm in the long direction, left at room temperature for 10 minutes, and then 20 at 60 ° C. By heating for a minute and curing both of these coatings together, a test plate for evaluating sagging resistance was obtained.

(Applied material)
The object to be coated 1 assuming a newly installed coated plate was manufactured as follows.

Object to be coated 1: 30 cm x 45 cm size epoxy resin-based electrodeposition paint is applied on the electrodeposition coating plate, intermediate coating paint ("TP-65-2", trade name, manufactured by Kansai Paint Co., Ltd., polyester. The melamine resin-based automobile intermediate coating paint) was air-spray coated so as to have a cured film thickness of 35 μm, and heat-cured at 140 ° C. for 30 minutes. Next, under coating conditions of a temperature of 23 ° C. and a relative humidity of 68%, a water-based base coat paint composition (“WBC-713T NO.202” (trade name, manufactured by Kansai Paint Co., Ltd., water-based for acrylic melamine resin-based automobiles) was applied onto the coating film. The top coat base coat paint (black paint color) is applied to a film thickness of 15 μm, left at room temperature for 5 minutes, preheated at 80 ° C. for 3 minutes, and then applied onto the uncured colored base coating film. As a new matte paint, the matte paint composition (15) shown in Table 3-3 described later is coated so that the cured film thickness is 35 μm, left at room temperature for 10 minutes, and then heated at 140 ° C. for 20 minutes. The object to be coated 1 was produced by curing the object to be coated. The 60-degree gloss value of the object to be coated 1 was 18.

(Examples 2 to 14 and Comparative Examples 1 to 6)
In Example 1, the Ford Cup No. 1 at 20 ° C. was the same as in Example 1 except that the compounding composition was as shown in Tables 3-1 and 3-2 and 3-3 below. Matte paint compositions (2) to (20) having a viscosity according to No. 4 of 15 seconds were obtained. Using each matte coating composition, each coated plate for gloss stability and alkali resistance test and each test plate for sagging resistance evaluation were produced in the same manner as in Example 1.

(Example 15)
In Example 1, a coated plate for gloss stability and alkali resistance test was produced in the same manner except that the object to be coated was the following object 2, and the gloss stability was A and the alkali resistance was S. there were.

Subject 2 (thin film): In the method for producing the object to be coated 1, the method for producing the object to be coated 1 except that the dry film thickness of the matte coating composition (15) shown in Table 3-3 described later is 25 μm. The object to be coated 2 was produced in the same manner as in the above. The 60-degree gloss value of the object to be coated 2 was 14.

(Example 16)
In Example 1, a coated plate for gloss stability and alkali resistance test was produced in the same manner except that the object to be coated was the following object 3, and the gloss stability was A and the alkali resistance was S. there were.

Object to be coated 3 (thick film): The object to be coated 3 was prepared in the same manner as the method for producing the object to be coated 1 except that the dry film thickness of the coating composition (15) shown in Table 3-3 described later was 45 μm. .. The 60-degree gloss value of the object to be coated 3 was 22.

なお、表２〜表４に記載の各成分は下記のとおり。

The components shown in Tables 2 to 4 are as follows.

Main agent (I)
Matte B-1: ACEMATT OK-607, trade name, manufactured by Ebonic Industries, Inc., silica particles surface-treated with an organic compound, precipitated silica treated with wax, particle size (d50) 4.4 μm, specific surface area 130 m2 / G, solid content 100% by mass,
B-2: ACEMATT OK-520, trade name, manufactured by Ebonic Industries, Inc., silica particles surface-treated with an organic compound, precipitated silica treated with wax, particle size (d50) 6.5 μm, specific surface area 220 m 2 / g, Solid content 100% by mass,
B-3: Microflat MA-106, trade name, manufactured by Koyo Kagaku Co., Ltd., polycarbonate resin beads, particle size (d50) 5.8 μm, solid content 7% by mass, cyclohexanone / butyl acetate (20/73) mixed solvent In Example 13, the amounts of cyclohexanone and butyl acetate were calculated, and the amount of the organic solvent as the organic solvent β is shown in Tables 3-1 and 3-2 and 3-3.

Organic solvent Organic solvent (c1) -1: 3-methoxybutyl acetate, also known as methoxybutyl acetate, boiling point 171.3 ° C, water solubility 6.5 g / 100 g, no hydroxyl group,
Organic solvent (c1) -2: 3-methyl-3-methoxybutyl acetate, also known as: 3-methoxy-3-methylbutyl acetate, boiling point 188 ° C, water solubility 6.8 g / 100 g, no hydroxyl group,
Organic solvent (c1) -3: cyclohexanone, also known as anon, boiling point 156 ° C., [8.7 g / 100 g], no hydroxyl group), solvent for the matting agent B-3,
Organic solvent (c2) -1: "DBE": trade name, manufactured by DowDuPont, mixed solvent of dimethyl glutarate, dimethyl succinate and dimethyl adipate, boiling point 196 to 225 ° C., water solubility 5.3 g / 100 g,
Organic solvent (c2) -2: Aromatic hydrocarbon-based high boiling point solvent (containing non-toluene xylene), boiling point 190 ° C or higher, insoluble in water.
Organic solvent (c3) -1: Butyl acetate, boiling point 126 ° C, water solubility 0.7 g / 100 g,
Organic solvent (c3) -2: isobutyl acetate, boiling point 118 ° C, water solubility 1.6 g / 100 g
Organic solvent (c3) -3: Ethyl acetate, boiling point 77.1 ° C., water solubility 8.0 g / 100 g or more.

Additives Surface conditioner: BYK-337, trade name, manufactured by Big Chemie Japan Co., Ltd., silicon-based surface conditioner, polyether-modified polydimethylsiloxane, active ingredient 15% by mass,
Curing catalyst: SCAT2R, trade name, manufactured by Sanko Machinery Co., Ltd., organic metal catalyst mixture (di-n-butyltin bis fatty acid salt and 50% solvent naphtha solution of fatty acid zincs,
Ultraviolet absorber: Tinuvin (registered trademark) 1130, manufactured by BASF Japan, benzotriazole (BTZ) -based ultraviolet absorber,
Light stabilizer: Tinuvin® 292, manufactured by BASF Japan, Ltd.
Rheology control agent: Crosslinked polymer fine particles (P1) obtained in Production Example 5, average particle size 90 nm, acid value less than 0.5 mgKOH / g, hydroxyl value 24 mgKOH / g.

Performance test method In the present invention, it is important that all the performances are excellent, and if any one of them has a rating of "D" or "B", it fails.

Test item 1: Drying property Under coating condition 1, a steel sheet having a size of 30 cm × 45 cm is coated with a drying film thickness of 35 μm, and then left at room temperature (20 ° C.) for 30 minutes, and then the surface drying property of each test coated plate is obtained. Was examined by finger touch. As for the evaluation, A, B, and C pass, and D fails.

The time required for the coating film state to reach the curing and drying state is shown, and the shorter the coating film state, the better the drying property and the quick-drying property.

A: After 15 minutes, there is no tack on the surface and it is good.
B: After 20 minutes, there is no tack on the surface and it is good.
C: After 25 minutes, there was no tack on the surface and it was good.
D: After 25 minutes, there is a tack on the surface.

Test item 2: Matte property Under painting condition 1, a steel plate having a size of 30 cm × 45 cm is coated with each matte paint composition so as to have a dry film thickness of 35 μm, and then dried at 60 ° C. for 30 minutes. The 60 ° mirror surface gloss of the test plate was measured and evaluated. Less than 75 is a pass.

Test item 3: Gloss stability (gloss difference due to film thickness fluctuation)
In Example 1, each matte paint composition was coated in the same manner as the coating plate produced by painting each matte paint composition except that the film thickness was 25 μm, and the film thickness was 24 μm in the same manner. The 60 ° mirror surface gloss was measured with the coated plate produced in the above process, and the difference was evaluated according to the following criteria.

Gloss stability (gloss difference due to changes in painting booth conditions):
60 ° of a coated plate in which each matte coating composition is coated with a film thickness of 35 μm under coating condition 2 and a coated plate coated with a film thickness of 35 μm under coating condition 3 with the object to be coated 1 as an object to be coated. The mirror gloss was measured and the difference was evaluated according to the following criteria.

Gloss stability (comprehensive evaluation):
Gloss stability [Gloss difference due to film thickness variation: may be abbreviated as gloss difference (film thickness)] and Gloss stability [Gloss difference due to coating condition variation: may be abbreviated as gloss difference (coating condition)]. Based on the results, evaluation was made according to the following criteria. S and A pass and D fails.
S: Gloss stability [gloss difference (film thickness)] and gloss stability [gloss difference (painting condition)] are both less than 5.
A: Of the gloss stability [gloss difference (film thickness)] and the gloss stability [gloss difference (painting condition)], the difference is 5 or more and less than 10, and the difference is not 10 or more.
D: Among the gloss stability [gloss difference (film thickness)] and the gloss stability [gloss difference (painting condition)], the difference is 10 or more.

Test item 4: Sauce resistance Check the position where sagging of the coating film of 3 mm is observed from the lower end of the punch hole of each test plate for sagging resistance evaluation, and the film thickness at that position (sauce limit film thickness (μm)). ) Was measured to evaluate the sagging resistance. The larger the sagging limit film thickness, the better the sagging resistance.
Alternatively, S and A pass and D fails.
S: Sauce limit film thickness is 35 μm or more,
A: Sauce limit film thickness is 25 μm or more and less than 35 μm,
D: The sagging limit film thickness is less than 25 μm.

Test item 5: Alkali resistance 0.5 mL of 1% sodium hydroxide aqueous solution was dropped onto the coating film surface of the coated plate when coated with a film thickness of 35 μm prepared in each example and comparative example, and the temperature was 20 ° C. and the relative humidity was relative humidity. After being left in a 65% atmosphere for 24 hours, the coated surface was wiped off with gauze, and the appearance was visually evaluated according to the following criteria. S and A pass and D fails.
S: There is no abnormality on the coating film surface,
A: Discoloration (whitening) of the coating film surface is observed.
D: The discoloration (whitening) of the coating film surface is remarkable.

Claims (11)

A matte coating composition containing a main agent (I) and a curing agent (II).
The main agent (I) contains a hydroxyl group-containing acrylic resin (A), a matting agent (B) containing silica particles (b1), and an organic solvent (C).
The organic solvent (C) contains an organic solvent (c1) having a solubility (20 ° C.) in water in the range of 5 to 50 g / 100 g and a boiling point of less than 100 to 190 ° C., and
The content ratio of the silica particles (b1) and the organic solvent (c1) contained in the main agent (I) is
A matte coating composition characterized by being in the range of 70/30 to 10/90. The matte coating composition according to claim 1, wherein the content of the organic solvent (c1) is in the range of 5 to 55% by mass with respect to the total mass of all the solvents contained in the matte coating composition. thing. The matte coating composition according to claim 1 or 2, wherein the hydroxyl group-containing acrylic resin (A) has a glass transition temperature of 30 ° C. or higher. The matte coating composition according to any one of claims 1 to 3, wherein the silica particles (b1) are organically treated silica particles (b1'). Claims 1 to claim that the content of the silica particles (b1) is in the range of 5 to 40 parts by mass with respect to 100 parts by mass of the resin solid content of the hydroxyl group-containing resin (A) contained in the main agent (I). Item 3. The matte coating composition according to any one of Item 4. The matte coating composition according to any one of claims 1 to 5, wherein the curing agent (II) contains a polyisocyanate compound (D). The matte coating composition according to any one of claims 1 to 6, wherein the main agent (I) further contains a rheology control agent (E). The matte coating composition according to claim 7, wherein the rheology control agent (E) contains crosslinked polymer fine particles (e1). A coating film forming method for forming a coating film on the outermost surface by coating an object to be coated with the matte coating composition according to any one of claims 1 to 8. Step (1) of applying a primer surfacer to a damaged portion of an old coating film or a coated body to form a base-treated coating film (I).
Step (2) of coating the coloring base coating film composition on the undercoat coating film to form the coloring base coating film (II).
The step (3), in which the clear coating composition is applied onto the colored base coating film obtained in the step (2) and dried to form the clear coating film (III).
A method for repairing and painting a painted body, wherein the clear paint composition is the matte paint composition according to any one of claims 1 to 8. Step (1) of applying a primer surfacer to a damaged portion of an old coating film or a coated body to form a base-treated coating film (I).
Step (2) of coating the coloring base coating film composition on the undercoat coating film to form the coloring base coating film (II).
The step (3), in which the first clear coating film composition (CC1) is coated on the colored base coating film obtained in the step (2) and dried to form the first clear coating film (III).
A coated body comprising a step (4) of coating a second clear coating film composition (CC2) on the first clear coating film obtained in the step (3) to form a second clear coating film (IV). It is a repair painting method of
The repair coating method for a coated body, wherein the second clear coating composition (CC2) is the matte coating composition according to any one of claims 1 to 8.