JP3034619B2 - Matte paint and its painting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a matte paint which forms a coating film having particularly good acid resistance, matte resistance and scratch resistance, and also having good curability, water resistance, yellowing resistance and solvent resistance. Regarding the coating method.

[0002]

BACKGROUND OF THE INVENTION In automotive top coatings,
Acid rain (pH 2-5) based on air pollutants such as sulfur oxides and nitrogen oxides, which have recently become a global problem
There is a strong demand for the development of a paint that forms a coating film that can withstand such conditions.

Conventionally, urethane paints using a polyisocyanate compound as a cross-linking agent show excellent acid resistance, but are difficult to handle because they are of a two-pack type, and the polyisocyanate compound has a strong toxicity. There are drawbacks.
The use of a blocked polyisocyanate compound can solve these disadvantages, but the dissociation temperature is high and the coating is not sufficiently cured at the current line baking temperature (140-150 ° C). There is a problem that heat yellowing easily occurs.

Further, a composition comprising a carboxyl group-containing resin and an epoxy group-containing resin has excellent acid resistance, but has poor solvent resistance. Furthermore, a composition comprising a carboxyl group-containing resin, an epoxy group-containing resin and a melamine resin (JP-A-63-113087, JP-A-1-1
JP-A-39655) has a disadvantage that when a large number of functional groups are introduced in order to improve acid resistance and solvent resistance, compatibility is reduced. Also, a resin composition comprising a resin containing a carboxyl group, an epoxy group and a hydroxyl group in the same molecule and a melamine resin (see Japanese Patent Publication No. 47-3732) is known. If a large amount of the above functional groups are introduced into the former resin in order to improve the gelation, the resin tends to gel during the polymerization reaction, and is disadvantageous in terms of long-term storage stability.

[0005] On the other hand, automotive outer panel top coats are generally finished in glossy, glossy coatings.
Finished with a matte coating as a new design. Until now, silica powder has often been blended to finish a matte coating film, but since the silica powder floats on the surface layer of the coating film, when the coated surface is polished, the silica powder is detached and that portion is removed. However, the appearance is deteriorated due to gloss, which is not preferable. Furthermore, it has a defect that the scratch resistance, stain resistance, weather resistance and the like are also reduced.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve such problems, and as a result, this time, the present inventors have found that they have excellent acid resistance, matte resistance and scratch resistance, as well as curability and yellowing resistance. The present inventors have found a matte paint which forms a coating film having excellent solvent resistance and water resistance, and a method of applying the same, and have completed the present invention.

That is, the present invention relates to (A) a carboxyl group, a hydroxyl group and an epoxy group in the same molecule, having an acid value of 15 to 150 mg KOH / g, a hydroxyl value of 30 mg KOH / g or more, and an epoxy equivalent of 3000 to 3000 Fifteen
000 g / eq and number average molecular weight 3,000-30,
Acrylic resin having a carboxyl group, a hydroxyl group and an epoxy group in the same molecule, and having an acid value of 2 to 10 mgKOH / g and a hydroxyl value of 30 mgKOH / g
As described above, an acrylic resin having an epoxy equivalent of 250 to 2500 g / eq and a number average molecular weight of 3,000 to 30,000, (C) an amino resin, and (D) a particle diameter of 5 to 5
And a glass powder which is surface-treated with alumina and / or silica and has a molar ratio of carboxyl group of component (A) / epoxy group of component (B) of 1 μm.
/0.5 to 0.5 / 1, and the component (C) is 1 based on the total amount of the components (A), (B) and (C).
0 to 40% by weight, and the component (D) is contained in an amount of 30 to 120 per 100 parts by weight of the total of the components (A), (B) and (C).
A matte paint characterized by being blended in parts by weight, and

[0008] In a coating step of applying a colored coating and applying a clear coating on the coated surface, the present invention relates to a coating method characterized by using the above matte coating as the clear coating.

In the matte paint of the present invention, (A)
Since both components (B) have a carboxyl group, both components have excellent compatibility with the component (C).

The component (A) has many carboxyl groups but few epoxy groups, while the component (B) has many epoxy groups but few carboxyl groups. There is an advantage that almost no gelation or high molecular weight based on the reaction is observed.

The functional groups of the components (A) and (B) and the component (C) undergo a crosslinking reaction, and as a result, a coating film having excellent acid resistance, solvent resistance, weather resistance and smoothness is obtained. To form

Since the component (D) is blended, the matte coating film to be formed has a gloss value of 60% specular reflectance of 50%.
It can be easily adjusted to the following, and the gloss value of the matte coated surface that has been polished with a wax or an abrasive agent hardly changes, and the water resistance, scratch resistance, weather resistance, stain resistance, etc. It is remarkably superior to one using a matting agent, and is suitable as a matte coating film for automobile outer panels.

In the present invention, "matting" means that the gloss value of a coated surface formed using the above matting paint is JIS.
60% specular reflectance based on K5400, 6, 7 is 50%
Hereinafter, it refers to a coated surface of 30% or less. In the present invention,
The coated surface of the matte coating itself has such a gloss value and forms a matte coating film.

Hereinafter, the matte paint of the present invention will be described in more detail.

Component (A): contains a carboxyl group, a hydroxyl group and an epoxy group in the same molecule, and has an acid value of 15
１５０150 mgKOH / g, hydroxyl value 30 mgKOH / g or more, epoxy equivalent 3,000-15,000 g / eq
And an acrylic resin having a number average molecular weight of 3,000 to 30,000.

The acrylic resin (component (A)) having the above-mentioned properties includes, for example, a carboxyl group-containing monomer, a hydroxyl group-containing monomer and an epoxy group-containing monomer as essential components,
Further, it can be obtained by copolymerizing with other monomers as necessary.

The carboxyl group-containing monomer is preferably a polymerizable monomer having one or more carboxyl groups and one polymerizable unsaturated bond in one molecule, particularly preferably a carboxyl group-containing acrylic monomer. Is acrylic acid,
Methacrylic acid can be exemplified, furthermore maleic acid,
Examples thereof include maleic anhydride, itaconic acid and monoesters thereof, and one or more of these can be used.

The hydroxyl group-containing monomer is preferably a polymerizable monomer having at least one hydroxyl group and one polymerizable unsaturated bond in one molecule, particularly a hydroxyl group-containing acrylic monomer.
Specifically, hydroxyethyl (meth) acrylate,
Hydroxyalkyl (meth) acrylates such as hydroxypropyl (meth) acrylate and hydroxybutyl (meth) acrylate; 1,4-butanediol mono (meth) acrylate, ε-caprolactone adduct of hydroxyethyl (meth) acrylate, hydroxyethyl ( Ethylene and propylene adducts of meth) acrylates, and the like, and these can be used alone or in combination of two or more.

The epoxy group-containing monomer is a polymerizable monomer having at least one epoxy group (or glycidyl group) and one polymerizable unsaturated bond in one molecule, particularly an epoxy group-containing acrylic monomer. Are preferred, specifically, glycidyl methacrylate, glycidyl acrylate, methyl glycidyl methacrylate, methyl glycidyl acrylate, allyl glycidyl ether, and the like,
One or more of these can be used.

Other monomers copolymerizable with the above monomers do not contain the above carboxyl group, hydroxyl group and epoxy group, have one polymerizable unsaturated bond, Monomers copolymerizable with the monomer are preferred, and specifically, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n
-Butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate,
Alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, and tridecyl (meth) acrylate; cycloalkyl (meth) such as cyclohexyl (meth) acrylate
Acrylate; benzyl (meth) acrylate, phenyl (meth) acrylate, dimethylaminoethyl (meth) acrylate; di (alkyl) aminoalkyl (meth) such as diethylaminoethyl (meth) acrylate
Esters of acrylic acid and methacrylic acid such as acrylate can be mentioned. Furthermore, styrene, α
-Vinyl aromatic compounds such as methylstyrene and vinyltoluene; acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, acrylamide, methacrylamide, methylolacrylamide, methylolmethacrylamide, vinyl chloride, propylene, ethylene,
C ₄ -C ₂₀ α-olefins and the like can also be used.

In the component (A), the constituent ratio of each of the above monomers is such that the acid value, hydroxyl value and epoxy equivalent of the copolymer (acrylic resin) formed from these monomers fall within the above ranges. It may be adjusted so as to be performed. Further, the copolymerization reaction with each of the monomers can be carried out by a conventional method, and can be produced by any known polymerization method such as a solution polymerization method, a suspension polymerization method, a bulk polymerization method, and an emulsion polymerization method. be able to. At that time, as a polymerization initiator, azobisisobutyronitrile, 4,4'-azobis (4-cyanopentanoic acid), benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, cumene hydroperoxide, Potassium persulfate, hydrogen peroxide,
2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propioamide] and the like can be used, and if necessary, a chain transfer agent such as dodecyl mercaptan, mercaptoethanol, α-methylstyrene dimer, etc. Can also be used.

The reaction temperature is in the range of about 70 to about 130 ° C., preferably about 70 to 110 ° C., in order to suppress the carboxyl group / epoxy group reaction during the polymerization. Acrylic resin thus obtained [component (A)]
Is 15 to 150 mgKOH / g, preferably 50 to 120 mgKOH / g.
It can have an acid number in the range of mg KOH / g. When the acid value is less than 15, the reactivity with the epoxy group of the component (B) decreases, and the acid resistance of the formed coating film does not improve.
If it exceeds 50 mgKOH, the solubility of the solvent and the compatibility with the component (B) tend to decrease. In addition, the acrylic resin is 30 mgKOH / g or more, preferably 35 mgKOH / g or more.
It is important to have a hydroxyl value within the range of 100 mg KOH / g. If the hydroxyl value is less than 30 mg KOH / g, the crosslinking reactivity with the component (C) is poor. Further, the acrylic resin has an epoxy equivalent of 3,000 to 15,000.
g / eq, preferably 3,200-9,000 g / eq
When the epoxy value is larger than 15,000, the compatibility with the component (B) becomes poor, and conversely,
When the value is smaller than 0, the reaction between the carboxyl group and the epoxy group proceeds during the synthesis reaction of the component (A), and it is easy to increase the molecular weight and gel. The component (A) has a number average molecular weight of G
It is a value in terms of polystyrene using PC (gel permeation chromatograph), and is 3,000 to 30,0.
00, preferably in the range of 5,000 to 20,000. Component (A) has a number average molecular weight of 3,0.
If it is less than 00, the weather resistance and water resistance of the coating film are inferior and 3
If it is larger than 000, the finished appearance is likely to be deteriorated.

Component (B): contains a carboxyl group, a hydroxyl group and an epoxy group in the same molecule and has an acid value of 2 to 2
10 mg KOH / g, hydroxyl value is 30 mg KOH / g or more,
An acrylic resin having an epoxy equivalent of 250 to 2500 g / eq and a number average molecular weight of 3,000 to 30,000.

The acrylic resin (component (B)) having the above-mentioned properties includes, for example, a carboxyl group-containing monomer, a hydroxyl group-containing monomer and an epoxy group-containing monomer as essential components, and further contains other monomers if necessary. These monomers can be obtained by copolymerization using monomers, and these monomers are selected from those exemplified in the description of the component (A).
Or two or more species are preferable, and the composition ratio of these monomers needs to be adjusted so that the acid value, hydroxyl value and epoxy equivalent of the obtained acrylic resin (component (B)) are within the above ranges. It is. The copolymerization of these monomers can be carried out in the same manner as described for the component (A).

In the acrylic resin as the component (B), it is important that the acid value is in the range of 2 to 10 mgKOH / g, and if the acid value is less than 2, the compatibility with the component (A) becomes poor. Conversely, if it exceeds 10, the reaction between the carboxyl group and the epoxy group proceeds during the synthesis of the component (B), which tends to increase the molecular weight and gelation. The acrylic resin has a hydroxyl value of 30 mg KOH / g or more, preferably 35 to 1
Within a range of 00 mg KOH / g and a hydroxyl value of 3
If it is less than 0, the crosslinking reactivity with the component (C) is reduced.

Further, the epoxy equivalent of the acrylic resin is desirably in the range of 250 to 2,500, preferably 300 to 1,500.
If it is more than 0, the reactivity with the carboxyl group is reduced, and the acid resistance of the coating film is not improved. On the other hand, if it is less than 250, the compatibility with the component (A) tends to be reduced.

The acrylic resin (component (B)) is 3,000
~ 30,000, preferably 5,000 ~ 20,000
When the number average molecular weight is less than 3,000, the weather resistance and water resistance of the coating film are inferior, and when the number average molecular weight is more than 30,000, the finished appearance of the coating film is reduced. Cheap.

Component (C): Amino Resin The amino resin includes, for example, a methylolated amino resin synthesized from at least one of melamine, urea, benzoguanamine and the like, and formaldehyde.
Further, those obtained by partially or entirely alkyletherifying methylol groups with lower monohydric alcohols such as methanol, ethanol, propanol, isopropanol and butanol are also used as amino resins.

Organic solvents and / or water are suitable as solvents or dispersion media that can be used when mixing the above components (A), (B) and (C).

The composition ratio of the components (A), (B) and (C) is not strictly limited, and may vary depending on the type and use of each component. The ratio of component (A) to component (B) is the ratio of carboxyl group / component (A)
1 / 0.5 based on the molar ratio of the epoxy group of the component (B)
To 0.5 / 1, preferably 1 / 0.6 to 0.6 / 1. If the ratio is out of this range, the solvent resistance and adhesion of the coating film tend to be reduced. The compounding ratio of the component (C) is 10 to 40% by weight, preferably 15 to 30% by weight based on the total amount of the components (A), (B) and (C).
When the amount of the component (C) is less than 10% by weight, the crosslinking reaction between the component (C) and the hydroxyl group of the component (A) or the component (B) becomes insufficient, and the solvent resistance of the coating film is reduced. On the other hand, if it exceeds 40% by weight, the acid resistance of the coating film tends to be poor.

Component (D): glass powder having a particle size of 5 to 50 μm and surface-treated with alumina and / or silica.

First, the shape of the glass powder to be subjected to the surface treatment is most preferably spherical, but any other shape may be used, and a hollow shape is also used. If a large amount of hollow glass powder is blended, the transparency of the clear coating film tends to decrease, so it is not preferable to apply this to a dark colored coating surface, but it can be applied to a light colored coating surface without problems . The glass powder can be produced by a method known per se, and is composed of SiO ₂ , Al ₂ O ₃ , Na ₂ O, K ₂ O, M
Soda-lime glass whose main composition is gO and CaO.
Particularly, a low alkali type glass powder having a Na ₂ O content of 1% by weight or less in the glass powder is preferable.

Alumina and / or silica for surface-treating the glass powder are both inorganic. First, for example, an aqueous solution of an aluminum salt and / or a silicate is added to a water slurry of a glass powder to prepare a glass slurry. A film composed of these salts is formed on the powder surface. Although the temperature of this system may be room temperature, it may be appropriately heated.
Next, the resultant is neutralized with an acid or an alkali, and a hydrate of the treating agent is deposited on the surface of the glass powder, and the by-produced soluble salts are washed and removed, and dried. Film was deposited on the particle surfaces of the glass powder is preferably coating of _{Al 2 O 3 · nH 2 O} · SiO 2, to cover the surface of the glass powder. The treatment of the glass powder may be performed with alumina alone, but a composite treatment of alumina and silica is preferable.

The glass powder is used for matting a coating film, and has a particle size of 5 to 50 μm, preferably 8 to 50 μm.
It is necessary to use a resin having a particle size of 25 μm. When the particle diameter is smaller than 5 μ, the matting effect is reduced, and when the particle diameter is larger than 50 μ, the smoothness and stain resistance of the coated surface are deteriorated. In particular, the use of a material having a thickness of 8 to 25 μ provides a remarkable matting effect.

The component (D) is compounded in an amount of 100 parts by weight of the total resin solids in the components (A), (B) and (C).
30 to 120 parts by weight (preferably 40 to 110 parts by weight)
However, this blending amount is determined by the degree of matting.
For a matte of 10 to 30% with a 60 ° specular reflectance, the blending amount of the low alkali glass powder is 50 to 100 parts by weight.
Further, the glass powder to be blended in the present invention is further subjected to an organic treatment, whereby the water resistance is further improved. The treatment of the glass powder includes amino silane, glycid silane, acrylic silane and the like. Among them, amino silane and glycid silane are better.

The matte paint of the present invention may further contain, if necessary, a curing catalyst, a viscosity modifier (for example, organic montmorillonite, microgel, polyamide, etc.), a coating surface modifier (for example, silicone or acrylic resin), ultraviolet light An absorbent, a blocked polyisocyanate compound, a coloring pigment, a metallic pigment, an interference pigment and the like can be blended in usual amounts.

Examples of the curing catalyst include a phosphoric acid catalyst such as dibutylphosphoric acid and an amine block strong acid catalyst such as dodecylbenzenesulfonic acid and paratoluenesulfonic acid in order to promote a crosslinking reaction between a hydroxyl group and an amino group resin. And the like. In order to promote a crosslinking reaction between a carboxyl group and an epoxy group, for example, a quaternary ammonium salt such as tetrabutylammonium chloride and a quaternary phosphonium salt such as tetraphenylphosphonium chloride are suitable. ing.

The matte paint of the present invention can be obtained by dissolving or dispersing the above components in an organic solvent.
The form includes an organic solvent type, a high solid type and a non-aqueous dispersion type, and can be adjusted by a method known per se.

The matte coating method of the present invention is a coating method in which a cross-linking-curable coloring paint is applied, and a cross-linking-curable clear coating is applied to the coated surface, wherein the matte coating is used as the clear coating. It is a matte coating method characterized by the following.

The cross-linking-curable color coating used in this method is a coating containing a resin composition and a color pigment which are cross-linked and hardened by a three-dimensional cross-linking reaction at room temperature or under heating.

The above resin composition contains a base resin and a crosslinking agent as main components in principle. Examples of the base resin include an acrylic resin, a polyester resin, and an alkyd resin having a crosslinkable functional group. Examples of the crosslinker include a methylolated and / or alkyl etherified melamine resin and a urea resin, and a polyisocyanate compound (also a blocked product). Can also be used. In addition, a self-curing resin that does not use a crosslinking agent can also be used as the resin composition.

Further, a vinyl copolymer containing, as monomer components, a specific polysiloxane-based macromonomer having two or more free functional groups such as a hydroxyl group and an alkoxyl group, and an oxirane group-containing vinyl monomer, A mixture of a polymer having a polysiloxane-based macromonomer as an essential monomer component and a polymer having an oxirane group-containing vinyl monomer as an essential monomer component was used as a base resin.
A coating composition containing at least one selected from a Lewis acid, a proton acid, a metal alkoxide, an organometallic compound, and a compound having a Si—O—Al bond as a curing catalyst is a polysiloxane-based monomer component. A silanol group present in the macromonomer and a silanol group generated by hydrolysis of an alkoxyl group in the macromonomer,
The oxirane group in the oxirane group-containing vinyl monomer, which is another monomer component, becomes a cross-linking functional group. Since the difference in the degree of curing between the surface and the inside is small and shrinkage hardly occurs, it is suitably used in the present invention.

As the coloring pigment, one or more selected from ordinary coloring pigments such as titanium white, carbon black and phthalocyanine blue and metallic pigments can be used.

The coloring paint used in the present invention is preferably obtained by dissolving or dispersing the above resin composition and coloring pigment in an organic solvent and / or water. The form includes an organic solution type, a high solid type, a non-aqueous dispersion type, an aqueous solution type and an aqueous dispersion type, and can be adjusted by a method known per se. It may be a powder type paint.

In the matte coating finishing method of the present invention, the object to be coated (metal and / or plastic automobile outer panel) is subjected to surface treatment, primer coating and intermediate coating as required, and then the above-mentioned colored coating is applied. I do. The coating thickness is not limited, but is preferably 10 to 30 μm based on the cured coating film. After cross-linking and curing the colored coating film at room temperature to 160 ° C. or in an uncured state, the matte clear paint is applied to the coating film surface. The thickness of the clear coating film is suitably in the range of 20 to 100 µm based on the cured coating film. After applying the matte clear paint, it is preferable to cure at room temperature to 160 ° C. The matte clear coating film may have a single layer, but may have two or more layers if necessary.

The matte coating formed by the method of the present invention can be easily adjusted to have a gloss value of 50% or less in terms of a 60 ° specular reflectance, and furthermore, has a matte coated surface polished with a wax or an abrasive. The gloss value hardly changes, and
Acid resistance, water resistance, scratch resistance, weather resistance, stain resistance, and the like are remarkably superior to those using a conventional matting agent, and are particularly suitable as a matting paint film for automobile outer panels. Hereinafter, the present invention will be described more specifically with reference to Production Examples and Examples. Parts and% indicate parts by weight and% by weight, respectively.

I Production Example (1) Production of the matte paint (A) component: 450 parts of xylene and 150 parts of n-butanol were charged into a four-necked flask equipped with a stirrer, a thermometer, a condenser and a nitrogen inlet tube, and heated to 100 ° C. Heat. Here, the monomer components shown in Table 1 were added dropwise over 4 hours, kept at 100 ° C. for 2 hours, and then diluted with 400 parts of xylol to obtain a solid content of 50%.
Acrylic copolymers (a-1) to (a-4) were obtained. (2) Preparation of matte paint (B) component: 300 parts of xylene, n in the same reactor as used in the preparation of component (A)
-Charge 300 parts of butanol and heat to 100 ° C. After the monomer components shown in Table 1 were added dropwise over 4 hours, 2
The mixture was kept at 100 ° C. for a time and then diluted with 400 parts of xylol to obtain acrylic copolymers (b-1) to (b-4) having a solid content of 50%.

[0048]

[Table 1]

II Examples and Comparative Examples II-1 Matting Coating The amino resin [(C) component] and the glass powder [(D) component] were added to the (A) and (B) components obtained in the production example using a sand mill or the like. The resulting mixture was blended and adjusted to make a matte clear paint.

[0050]Example 1 Matte clear paint (C-
1): (A-1) 80 parts (b-1) 80% 60% Uban 20SE 33 (butylated melamine manufactured by Mitsui Toatsu) glass powder (Note-1) 100 {surface conditioner 0.1} (Vic Chem BYK-300) UV absorber 1.0〃 (Tinuvin 900 manufactured by Ciba-Geigy)
The cup (# 4) was adjusted to a viscosity of 25 seconds at 20 ° C. (Note-1) Glass powder Soda-lime glass powder (spherical, particle size 10μ, Toshiba Barote
Microbead MB-10 manufactured by Inini Co., Ltd.
Glass powder that has been treated.

[0051]Example 2 Matte clear paint (C-
2): (A-2) 90 parts (b-2) 70〃 Cymel 303 20〃 (Mitsui Cyanamid, Flumethoxymelamine) Glass powder (Note 2) 90〃 NACURE 5225 2〃 (King's dodecylbenzenesulfonate neutralized product) ) Surface conditioner (BYK-300) 0.1 {Ultraviolet absorber (Tinuvin 900) 1.0} The above mixture was produced in the same manner as in Example 1. (Note-2) Glass powder microbead MB-10 is treated with alumina and silica
And further treated with amino and silane.

[0052]Example 3 Matte clear paint (C-
3): (A-3) 80 parts (b-3) 80〃 60% Uban 20SE 33〃 glass powder (Note 3) 110〃 surface conditioner (BYK-300) 0.1〃 ultraviolet absorber (tinuvin 900) 1.0 {Tetrabutylammonium chloride 0.05} The above mixture was produced in the same manner as in Example 1. (Note-3) Glass powder Low alkali glass powder (E, manufactured by Toshiba Barotini Co., Ltd.
MB-10, spherical, particle size 10μ) was treated with alumina and silica
And then organically treated with amino and silane.

Comparative Example 1 Clear paint (C-4): (a-1) 100 parts (b-1) 30% 60% Uban 20SE 40 {glass powder (Note 1) 100} Surface modifier (BYK-300) 0.1 {UV absorber (Tinuvin 900) 1.0} The above mixture was prepared as in Example 1.

Comparative Example 2 Clear paint (C-5): (a-4) 80 parts (b-4) 80% 60% Uban 20SE 30 glass powder (Note 1) 100 surface modifier (BYK-300) 0.1 {UV absorber (Tinuvin 900) 1.0} The above mixture was prepared as in Example 1.

Example 4 Matte Coloring Paint (S-1): Titanium White JR-701 50 parts (Titanium Dioxide Co., Ltd., titanium dioxide) (a-3) 80 parts (b-2) 80% 60% Euban 20SE 33 {Glass powder (Note-3) 100} A mixture of 0.1% of surface conditioner (BYK-300)
The viscosity was adjusted to up (# 4) 25 seconds.

II-2 Matting coating method An electrodeposition coating film and an intermediate coating film were formed on a mild steel sheet treated with zinc phosphate, and the following metallic coating was applied (film thickness: cured film thickness: 20 μm). After standing for minutes, the matte clear coatings (C-1) to (C-5) were applied to the coated surface (film thickness: 40 μm as above), and heated at 140 ° C. for 30 minutes to simultaneously cure both coatings. Table 2 shows the performance test results of the obtained coating films.

(Metallic paint): 100 parts of acrylic resin (Acrylic 47-712 manufactured by Dainippon Ink and Chemicals, Inc.) 60 parts of butylated melamine (Mitsui Toatsu Co., Ltd., Uban 20SE-60) Aluminum paste 10 parts (Toyo Aluminum Co., Ltd.) Aluminum paste 55-519) Ford cup No. 4 (20) was prepared using a mixed solvent consisting of 30 parts of swazole # 1000 and 70 parts of toluene.
° C) was adjusted to 14 seconds.

II-3 Colored paint: The above-mentioned colored paint (S-1) was applied to a zinc phosphate-treated steel sheet which had been electrodeposition-coated and intermediate-coated in the same manner as described above (coating thickness: 40 μm), 140 The mixture was cured by heating at 30 ° C. for 30 minutes. Table 2 shows the performance test results of the obtained coating films.
Table 2 also shows the mixing ratio of each component of each paint.

[0059]

[Table 2] After washing, the coated surface was observed and evaluated according to the following criteria. 〇: No change at all. Δ: There is no abnormality in the coated surface, but a slight step is recognized at the boundary between the immersed part and the non-immersed part. X: The coating surface was whitened. Recoat adhesion: After baking each sample at 160 ° C for 30 minutes, apply the same overcoat (base coat / clear coat in the case of metallic) on it and bake it at 140 ° C for 30 minutes, then 100 crosscuts at 1mm intervals Is inserted, and the presence or absence of the peeling is determined using a cellophane tape. 〇: No peeling was observed at all. Δ: Slight peeling was observed. X: Remarkable peeling is observed.

Water resistance: After being immersed in warm water of 40 ° C. for 240 hours, it was washed with water, the coated surface was observed, and evaluated according to the following criteria. 〇: No change at all. Δ: Slightly glossy. X: The coating surface was whitened.

Finished appearance: Visual judgment. Stain resistance: 5 ×
Place 1 g of JIS Class 15 contaminated dust on a 5 cm coated plate and spread it evenly by sweeping it 20 times with a brush.
For 24 hours. Next, this was washed in running water using a clean brush, and the degree of contamination was examined. ◎: No stain is observed at all. 〇: Stain is slightly observed. Δ: Stain is considerably observed. X: Stain is remarkably observed.

Scratch resistance: A dyestuff rub fastness test (manufactured by Daiei Chemical Seiki Seisakusho) was used. The polishing powder (Dharma Cleanser) is kneaded with water, placed on the coated surface, pressed on the tester terminal, applied with a load of 0.5 kg, and rubbed back and forth for 25 times. After washing with water, the degree of scratches was determined in four stages of ◎, Δ, Δ, and ×.

Accelerated weathering resistance: A QUV accelerated backlash test was conducted using an accelerated weathering resistance tester manufactured by Q Panel. Test conditions: UV irradiation 16H / 60 ° C water condensation 8H / 50 ° C as one cycle, and the coating film was evaluated after 3000 hours (125 cycles). ：: The gloss is maintained almost unchanged from the initial state. 〇: There is a slight decrease in gloss, but no defect such as cracking or whitening. Δ: A decrease in gloss and whitening were observed. ×: Significant decrease in gloss, cracking, and whitening were observed,
Fail.

Impact resistance: Using a Dupont impact tester, the test is carried out with a firing pin tip radius of 1/2 inch and a falling bell weight of 500 g. The maximum height at which the cracks do not enter the painted surface is shown (in 5 cm increments).

────────────────────────────────────────────────── ─── Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 5/00 C09D 133/14 C09D 161/20 Patent file (PATOLIS)

Claims (2)

(57) [Claims] (A) A carboxyl group, a hydroxyl group and an epoxy group are contained in the same molecule and the acid value is 15 to 15
Acrylic resin having 0 mg KOH / g, a hydroxyl value of 30 mg KOH / g or more, an epoxy equivalent of 3000 to 15000 g / eq, and a number average molecular weight of 3,000 to 30,000, (B) a carboxyl group, a hydroxyl group and an epoxy Group having an acid value of 2 to 10 mg KOH /
g, a hydroxyl value of 30 mg KOH / g or more, an epoxy equivalent of 250 to 2500 g / eq, and a number average molecular weight of 3.0
(A) an amino resin having a particle size of from 50 to 30,000, and (D) an amino resin, and (D) a glass powder having a particle size of 5 to 50 μm and having a surface treatment with alumina and / or silica. A) Carboxyl group of component /
The epoxy group molar ratio of the component (B) is 1 / 0.5 to 0.5 /
1, and the component (C) is contained in an amount of 10 to 40% by weight based on the total amount of the components (A), (B) and (C), and the component (D) is contained in the components (A), (B) and (C) A matte paint characterized by being mixed with 30 to 120 parts by weight per 100 parts by weight of the total of the components. 2. A matte coating method, characterized in that a matte paint selected from the paint of claim 1 is used as the clear paint in a coating step of applying a color paint and applying a clear paint on the coated surface. .