JP2005187701A - Water-borne matte coating composition and method for coating therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-borne matte coating composition having excellent storage stability, suppressing the nonuniform gloss of the formed coating film and having excellent matting effect and provide a method for coating with the coating composition. <P>SOLUTION: The water-borne matte coating composition contains (A) a synthetic resin emulsion, (B) a resin bead having a specific gravity of ≥1.0 and ≤1.5 and (C) a wax having a specific gravity of ≥0.7 and <1.0. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a water-based matte coating composition capable of preventing uneven coating and uneven gloss and a coating method thereof.

  Conventionally, the surface of an object to be coated has been painted with a paint for the purpose of improving the appearance and protecting the substrate.

Examples of objects to be coated include daily products such as electrical products, office automation equipment, furniture, furniture, and toys, industrial products such as machinery and equipment, ships, vehicles, buildings, structures, plants, tanks, bridges, signs, etc. In all of these applications, matte paint is often applied to reduce gloss and gloss and to create a subdued texture.
For example, in the field of construction and civil engineering, natural paints such as natural stone coating materials and multicolored paints are often applied to the walls of buildings and structures. In order to achieve this, it is common to apply a clear matte paint.

  Furthermore, in recent years, in accordance with environmental regulations, a shift from solvent-based paints to water-based paints is being attempted, and thus water-based transparent matte paints are often required.

  A water-based transparent matte coating is generally obtained by blending a matting agent such as silica, calcium carbonate, and polymer fine particles with an aqueous resin or the like. However, simply adding a matting agent to an aqueous resin or the like may result in poor storage stability. When such matting paint is applied, gloss unevenness occurs in the formed coating film, resulting in excellent gloss. In some cases, the erase effect could not be demonstrated. In particular, when coating is performed on a substrate surface having irregularities, the matting paint easily migrates to the concave portions, and therefore, there is a high possibility that uneven gloss will occur.

For example, Patent Document 1 solves such a problem by adding a suspension stabilizer to a water-dispersed paint and a matting agent (thermoplastic organic fine particles).
However, in Patent Document 1, it may be difficult to suppress the occurrence of uneven gloss, and there may be cases where a satisfactory matting effect cannot be exhibited.
In particular, gloss unevenness often occurs on the surface of a substrate having irregularities, and a sufficient matting effect may not be exhibited.

JP 2002-212490 A

  In order to solve these problems, the present inventor has intensively studied, and as a result, an aqueous matte containing (A) a synthetic resin emulsion, (B) resin beads having a specific gravity, and (C) wax having a specific gravity. The present inventors have found that the coating composition is excellent in storage stability, can suppress the uneven gloss of the formed coating film, and is excellent in the matting effect, and has completed the present invention.

That is, the present invention has the following characteristics.
1. (A) A synthetic resin emulsion, (B) a resin bead having a specific gravity of 1.0 to 1.5, and (C) a wax having a specific gravity of 0.7 to less than 1.0. A water-based matte coating composition comprising:
2. (A) 1 to 100 parts by weight of resin beads and (C) 1 to 100 parts by weight of wax are contained with respect to 100 parts by weight of the solid content of the synthetic resin emulsion. A water-based matte coating composition as described in 1.
3. (C) The wax is a wax emulsion. Or 2. A water-based matte coating composition as described in 1.
4). On the substrate surface having irregularities, 1. To 3. A coating method comprising applying the water-based matte coating composition according to any one of the above.

  The aqueous matte coating composition of the present invention is excellent in storage stability, can suppress uneven glossiness of the formed coating film, and is excellent in matting effect. Further, the formed coating film is excellent in water resistance and transparency.

  Hereinafter, it explains in detail with the best form for carrying out the present invention.

  The aqueous matte coating composition of the present invention comprises (A) a synthetic resin emulsion (hereinafter also referred to as “component (A)”), (B) resin beads having a specific gravity of 1.0 or more and 1.5 or less (hereinafter, And (C) a wax having a specific gravity of 0.7 or more and less than 1.0 (hereinafter also referred to as “(C) component”).

The component (A) is a component that mainly serves as a binder.
The component (A) is not particularly limited, and is an acrylic resin emulsion, silicon resin emulsion, fluorine resin emulsion, acrylic silicon resin emulsion, vinyl acetate resin emulsion, vinyl chloride resin emulsion, urethane resin emulsion, epoxy resin emulsion, alkyd resin emulsion. , Polyvinyl alcohol resin emulsion, ethylene resin emulsion, polyester resin emulsion and the like can be used by mixing one or more kinds, and in the present invention, in particular, acrylic resin emulsion, silicon resin emulsion, fluororesin emulsion, acrylic It is preferable to use a silicone resin emulsion or a urethane resin emulsion.

As the monomer used in component (A),
(Meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxymethyl, (meth) acrylic acid-2-hydroxypropyl, (meth) acrylic acid-3-hydroxypropyl, (meth) acrylic acid- Hydroxyl group-containing monomers such as 2-hydroxybutyl, 4-hydroxybutyl (meth) acrylate, ethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, glycerol mono (meth) acrylate;

  Carboxyl group-containing monomers such as (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, isocrotonic acid, salicylic acid, cinnamic acid;

  Aminomethyl (meth) acrylate, aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, aminobutyl (meth) acrylate, butylvinylbenzylamine, vinylphenylamine, p-aminostyrene, (meth) acrylic Acid-N-methylaminoethyl, (meth) acrylic acid-Nt-butylaminoethyl, (meth) acrylic acid-N, N-dimethylaminoethyl, (meth) acrylic acid-N, N-dimethylaminopropyl, (Meth) acrylic acid-N, N-diethylaminoethyl, (meth) acrylic acid-N, N-dimethylaminopropyl, (meth) acrylic acid-N, N-diethylaminopropyl, N- [2- (meth) acryloyloxy Ethyl] piperidine, N- [2- (meth) acryloyloxyethyl] pyrrolidine, N- [ -(Meth) acryloyloxyethyl] morpholine, 4- [N, N-dimethylamino] styrene, 4- [N, N-diethylamino] styrene, 2-vinylpyridine, 4-vinylpyridine and other amino group-containing monomers ;

  (Meth) acrylic acid glycidyl, diglycidyl fumarate, (meth) acrylic acid-3,4-epoxycyclohexyl, 3,4-epoxyvinylcyclohexane, allyl glycidyl ether, (meth) acrylic acid-ε-caprolactone-modified glycidyl, An epoxy group-containing monomer such as (meth) acrylic acid-β-methylglycidyl;

  (Meth) acrylamide, N-methylol (meth) acrylamide, diacetone (meth) acrylamide, N-monoalkyl (meth) acrylamide, N-isobutoxymethylacrylamide, N, N-dialkyl (meth) acrylamide, 2- (dimethylamino) ) Amide group-containing monomers such as ethyl (methacrylate), N- [3- (dimethylamino) propyl] (meth) acrylamide and vinylamide;

Alkoxysilyl group-containing monomers such as (meth) acrylic acid trimethoxysilylpropyl and (meth) acrylic acid triethoxysilylpropyl;
Hydrolyzable silyl group-containing monomers such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, and γ- (meth) acrylopropyltrimethoxysilane;
Nitrile group-containing monomers such as acrylonitrile and methacrylonitrile;
Methylol group-containing monomers such as N-methylol (meth) acrylamide;
Oxazoline group-containing monomers such as vinyloxazoline and 2-propenyl 2-oxazoline

Methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylic acid-n-propyl, (meth) acrylic acid-n-butyl, (meth) acrylic acid-t-butyl , (Meth) acrylic acid-sec-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid-2-ethylhexyl, (meth) acrylic acid-n-hexyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid Octyl, lauryl (meth) acrylate, stearyl (meth) acrylate, glycidyl (meth) acrylate, trifluoroethyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, (meta ) Octyl acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, (meth) acrylic Dodecenyl acid, Otadecyl (meth) acrylate, Cyclohexyl (meth) acrylate, 4-tert-butylcyclohexyl (meth) acrylate, Phenyl (meth) acrylate, Isobornyl (meth) acrylate, Benzyl (meth) acrylate (Meth) acrylate monomers such as 2-phenylethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, and 4-methoxybutyl (meth) acrylate;

Vinylidene halide monomers such as vinylidene fluoride;
Aromatic vinyl monomers such as styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, vinylanisole, vinylnaphthalene, divinylbenzene;
Other monomers such as ethylene, propylene, isoprene, butadiene, vinyl acetate, vinyl ether, vinyl ketone, silicone macromer;
Etc., and one or more of these can be used.

  In the present invention, the ultraviolet ray resistance of the formed coating film can be improved and the weather resistance and durability can be improved by copolymerizing a compound having an ultraviolet absorbing effect in the resin of component (A). preferable.

  It does not specifically limit as a polymerization method, What is necessary is just to use a well-known polymerization method etc. You may add an initiator, an emulsifier, a chain transfer agent, etc. or another additive as needed. For example, the monomer component can be obtained by emulsion polymerization in the presence of a known radical polymerization initiator such as a peroxide or an azo compound.

In the present invention, a crosslinked type synthetic resin emulsion is particularly preferable as the component (A). A cross-linked synthetic resin emulsion is preferred because the coating film properties such as water resistance are improved.
As the cross-linking type synthetic resin emulsion, those having the following reactive functional group combinations are preferable, and those having a reactive functional group combination in the synthetic resin emulsion may be used, and reactions such as known cross-linking agents may be used. It may be a combination with a functional group.

  Examples of combinations of reactive functional groups include carboxyl groups and carbodiimide groups, carboxyl groups and epoxy groups, carboxyl groups and aziridine groups, carboxyl groups and oxazoline groups, hydroxyl groups and isocyanate groups, carbonyl groups and hydrazide groups, epoxy groups and amino groups. Groups, hydrolyzable silyl groups, and the like.

The average particle size of the component (A) is not particularly limited, but is preferably 30 nm to 250 nm (more preferably 50 nm to 200 nm).
The particle diameter in the present invention is a value measured by a dynamic light scattering method.
Specifically, as a dynamic light scattering measurement device, using a Microtrac particle size analyzer (for example, UPA150, Nikkiso Co., Ltd.), the detected scattering intensity is a value analyzed by the Marquardt method of the histogram analysis method, The measurement temperature is 25 ° C.

  Although the glass transition temperature of (A) component is not specifically limited, It is preferable that they are -40 degreeC to 80 degreeC, Furthermore, it is -20 degreeC to 60 degreeC.

The glass transition temperature is a value calculated from the Fox (FOX) equation. For example, in a two-component system composed of monomer (1) and monomer (2), when the glass transition points Tg (1) and Tg (2) of the respective homopolymers are known, the monomers (1) and ( The glass transition point Tg of the two-component copolymer 2) can be obtained as a calculated value from the Fox (FOX) formula (two components) shown in the following formula.
1 / Tg = W (1) / Tg (1) + W (2) / Tg (2) (W (1) + W (2) = 1)
W (1): weight fraction of monomer (1), W (2): weight fraction of monomer (2), Tg (1): Tg value of homopolymer of monomer (1) (unit: K), Tg (2): Tg value (unit: K) of homopolymer of monomer (2)
The Tg value of the polymer in the present invention is calculated by a generalized formula of the above formula to a multicomponent system.

In addition, the refractive index of the formed coating film of component (A) is 1.35 or more and 1.75 or less (more preferably 1.40 or more and 1.70 or less, and further preferably 1.45 or more and 1.65 or less). It is preferable.
The refractive index of the formed coating is in accordance with JIS K 7105-1981 5.1 “refractive index”, at a temperature of 23 ° C. and a humidity of 50% RH, and an Abbe refractometer (for example, manufactured by Atago Co., Ltd.). Can be measured.

The component (B) is a component that mainly exhibits a matting action.
The component (B) has a specific gravity of 1.0 or more and 1.5 or less (preferably 1.05 or more and 1.40 or less, more preferably 1.10 or more and 1.30 or less), and thus is generally used as a matting agent. Compared to inorganic particles such as silica and calcium carbonate, the specific gravity is light, the dispersibility is good for the component (A), the storage stability is excellent, and gloss unevenness can be suppressed.

The component (B) is not particularly limited, and urethane beads, acrylic beads, polyethylene beads, polypropylene beads, polymethyl methacrylate beads, polystyrene beads, nylon beads, styrene acrylic beads, silicon beads, fluorine beads, cellulose beads, and chloride. One kind or two or more kinds such as vinyl beads and EVA beads can be mixed and used.
In the present invention, urethane beads, acrylic beads, polyethylene beads, polypropylene beads, polymethyl methacrylate beads and the like are preferable.

  (B) It is preferable that the average particle diameter of a component is 1 micrometer-20 micrometers (further 5 micrometers-10 micrometers). When the average particle size of the component (B) is in such a range, an excellent matting effect can be obtained. If it is smaller than 1 μm, the matting effect may be reduced. If it is larger than 20 μm, the finish may be inferior.

  The refractive index of the component (B) is preferably 1.35 or more and 1.75 or less (more preferably 1.40 or more and 1.70 or less, further preferably 1.45 or more and 1.65 or less). In the present invention, it is preferable that the refractive index of the component (B) and the refractive index of the component (A) are approximate. Specifically, the difference between the refractive index of the component (B) and the refractive index of the component (A) is preferably 0.1 or less, more preferably 0.05 or less. When the refractive index of the component (B) is close to the refractive index of the component (A), a coating film excellent in transparency can be formed.

Component (C) is a component that has a matting effect and a gloss unevenness prevention effect, and further improves storage stability.
Component (C) has a specific gravity of 0.7 or more and less than 1.0 (preferably 0.75 or more and 0.98 or less, more preferably 0.80 or more and 0.95 or less). Stability etc. can be improved more and gloss unevenness can be suppressed more.
Although the details are not clear, the component (C) tends to be oriented on the surface of the formed coating film, and thus can prevent gloss unevenness, and further improve the water resistance of the coating film. It seems to be possible.

  Examples of the component (C) include polyethylene wax and derivatives thereof, montan wax and derivatives thereof, paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, petrolatum, carnauba wax, candelilla wax, rice wax, wood wax, and lanolin. , Beeswax, Fischer-Tropsch wax and the like can be used alone or in combination. In particular, polyethylene wax and paraffin wax are preferred in the present invention.

  Although the form of (C) component is not specifically limited, such as solid and a liquid, In this invention, it is preferable that it is a liquid and it is especially preferable that it is a wax emulsion. A wax emulsion is preferred because it is more excellent in dispersibility, stain resistance and the like.

  When the component (C) is a wax emulsion, the average particle size of the emulsion particles is preferably 0.5 μm to 20 μm (more preferably 1 μm to 10 μm).

The refractive index of the component (C) is preferably 1.35 or more and 1.75 or less (more preferably 1.40 or more and 1.70 or less, more preferably 1.45 or more and 1.65 or less). In addition, when (C) component is a wax emulsion, it means the refractive index of emulsion particles.
In the present invention, it is preferable that the refractive index of the component (C) is close to the refractive index of the component (A). Specifically, the difference between the refractive index of the component (C) and the refractive index of the component (A) is preferably 0.1 or less, more preferably 0.05 or less. Since the refractive index of the component (C) is close to the refractive index of the component (A), a coating film excellent in transparency can be formed, which is preferable.

In the present invention, an excellent matting effect can be exhibited by mixing the component (A), the component (B), and the component (C). Furthermore, since the component (A), the component (B), and the component (C) are composed of organic components, they are well dispersed and excellent in storage stability, and uneven gloss of the formed coating film can be suppressed.
In addition, the refractive index of the coating film of component (A) and the refractive index of component (B), the refractive index of the coating film of component (A) and the refractive index of component (C), and the refraction of component (B) The difference between the refractive index and the refractive index of the component (C) is preferably 0.1 or less, and more preferably 0.05 or less. Can also be shown.

  The mixing ratio of the component (A), the component (B), and the component (C) is 1 to 100 parts by weight (more preferably 5 to 60 parts by weight) of the component (B) with respect to 100 parts by weight of the solid content of the component (A). Parts, more preferably 10 to 40 parts by weight), and component (C) is preferably 1 to 100 parts by weight (more preferably 5 to 60 parts by weight, still more preferably 10 to 40 parts by weight). Moreover, it is preferable that (C) component is 10-1000 weight part (more preferably 15-800 weight part, More preferably, 30-500 weight part) with respect to 100 weight part of (B) component. (In addition, when (C) component is a wax emulsion, it is a value of solid content weight.)

By being in such a range, the matte effect is excellent, the storage stability is excellent, the gloss unevenness of the formed coating film can be further suppressed, and the transparency and water resistance of the formed coating film are also excellent. An aqueous matte coating composition can be obtained.
When the component (B) is more than 100 parts by weight relative to 100 parts by weight of the solid content of the component (A), the storage stability may be inferior. When the amount is less than 1 part by weight, an excellent matting effect may not be obtained.
When the component (C) is more than 100 parts by weight relative to 100 parts by weight of the solid content of the component (A), the transparency of the formed coating film may be impaired. When the amount is less than 1 part by weight, storage stability may be inferior, and gloss unevenness may not be suppressed.
When the component (C) is more than 1000 parts by weight relative to 100 parts by weight of the component (B), the transparency of the formed coating film may be impaired. When the amount is less than 10 parts by weight, the storage stability may be inferior.

  In addition to the above components, the water-based matte coating composition of the present invention can also contain known additives to the extent that the effects of the present invention are not impaired. Examples of such additives include solvents, pigments, film-forming aids, light stabilizers, antifoaming agents, thickeners, ultraviolet absorbers, infrared absorbers, and the like.

The water-based matte paint composition of the present invention includes, for example, daily products such as electric products, OA equipment, furniture, furniture, and toys, industrial products such as machinery and equipment, ships, vehicles, buildings, structures, plants, tanks. It can be applied to bridges, signs, etc.
Typical examples of the base material used include metal steel plates such as aluminum steel plates, galvanized steel plates, stainless steel plates and copper steel plates, wood, concrete, mortar, gypsum boards, fiber-mixed cement boards, calcium silicate boards, and slag cements. A pearlite board, an asbestos-cement board, an ALC board, a siding board, an extrusion board, a plastic board, a ceramic, glass, a fired tile, a porcelain tile, etc. are mentioned, These may be given some surface treatment. In addition, these base materials may be previously coated with a paint.
Furthermore, a design coating film such as a natural stone-like coating material or a multicolored paint may be applied on such a base material.

  The coating method of the aqueous matte coating composition of the present invention can be applied by a known method. For example, it can be applied using a painting device such as a brush, a trowel, a roller, or a spray. In the present invention, the coating may be performed once, but may be performed a plurality of times. In the present invention, gloss unevenness can be suppressed even when coating is performed a plurality of times, and an appearance with excellent aesthetics can be obtained.

The water-based matte coating composition of the present invention has a property that the component (C) is more easily oriented on the surface than the component (B) due to the specific gravity during coating film formation. Therefore, the component (C) is rich in the vicinity of the surface (upper part) of the formed coating film, and tends to be a component rich in the component (B) as it approaches the lower part of the formed coating film. Such orientation is maintained even when the film thickness of the formed coating film is changed, so that it is considered that the degree of matting can be kept constant.
Therefore, gloss unevenness can be suppressed. In particular, gloss unevenness can be suppressed even in coatings where the film thickness of the coating film is not constant and coatings with uneven surfaces where it is difficult to make the film thickness of the coating film constant. can do.

For example, when coating is performed on a substrate surface having irregularities, the coating component tends to migrate to the recesses, and the film thickness of the coating film is often not constant. In the present invention, since the orientation of the component (B) and the component (C) is maintained, even if the film thickness is not constant, there is no change in the degree of matting effect, and uneven gloss can be suppressed.
Furthermore, even when such a coating is applied a plurality of times, gloss unevenness can be suppressed by the above effect.

The degree of unevenness of the substrate having unevenness is not particularly limited, and gloss unevenness can be suppressed even when the difference between the bottom and the top is 1 mm or more.
The substrate having unevenness is not particularly limited, and examples thereof include the above-mentioned substrates, and those having a design coating film such as natural stone-like coating material or multicolored paint on the substrate may be used. .

The coating film formed from the water-based matte coating composition of the present invention is excellent in transparency, and specifically the hiding rate is preferably 10% or less, more preferably 5% or less. With such a concealment rate, an excellent matting effect can be exhibited without hindering the design of the substrate.
The concealment rate is a value measured with a color difference meter “CR-300” (manufactured by Minolta Co., Ltd.) using a concealment rate test paper so that the coating thickness is 0.15 mm.

  Examples and Comparative Examples are shown below to clarify the features of the present invention, but the present invention is not limited to these Examples.

(Examples 1-4, Comparative Examples 1-4)
Using the raw materials shown in Table 1, mixing was performed according to the formulation shown in Table 2 to obtain an aqueous paint. The obtained water-based paint was subjected to the following test.

(Storage stability test)
250 ml of the prepared water-based paint was put into a 300 ml capacity cup and stored for 30 days in a thermostatic bath at 50 ° C., and then the viscosity change was confirmed. The evaluation is as follows. The results are shown in Table 2.
A: Less than 20% B: Viscosity change 20% to less than 50% Δ: Viscosity change 50% to less than 80% X: Viscosity change 80% or more

(Gloss unevenness test 1)
Acrylic paint (solid content: 40%) was applied with a coating thickness of 0.3 mm, and the prepared water-based paint was applied by air spray on a slate plate (150 mm x 70 mm x 3 mm) cured for 7 days. Application was performed at 15 kg / m ² and curing was performed for 2 hours to obtain a specimen A.
Next, the same water-based paint was applied onto the test body A at a coating amount of 0.15 kg / m ² and cured for 2 hours to obtain a test body B.
Next, the same water-based paint was applied onto the test body B at a coating amount of 0.15 kg / m ² and cured for 7 days to obtain a test body C.
The glossiness of the obtained specimens A, B, and C was measured using a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd.). The incident angle during measurement was 85 degrees.
The gloss unevenness was evaluated as follows based on the difference in glossiness between the specimens A and B and the difference in glossiness between the specimens B and C. The results are shown in Table 2.
A: Glossiness difference is less than 1.0 for both. B: Larger glossiness difference is 1.0 or more and less than 2.0. Δ: Larger glossiness difference is 2.0 or more and less than 5.0. : Larger gloss difference is 5.0 or more

(Gloss unevenness test 2)
On a slate plate (150 mm × 70 mm × 3 mm), a design coating material (acrylic resin emulsion (solid content 50%) 200 parts by weight, colored aggregate 200 parts by weight, extender pigment 200 parts by weight, additive (thickener) , antifoam) 20 parts by weight) was subjected coating, on a substrate subjected to protrusion process, the water-based paint prepared in air spray coating subjected in coat-weight 0.15 kg / m ^2, 2 Then, the same water-based paint was applied at a coating amount of 0.15 kg / m ² and cured for 7 days to obtain a specimen D. In the convex portion treatment, unevenness having a difference between the bottom and the top of about 2 mm was applied.
For gloss unevenness, the surface of the obtained specimen D was visually evaluated as follows. The results are shown in Table 2.
◎: No gloss unevenness was observed. ○: No gloss unevenness was observed. Δ: Some gloss unevenness was observed.

(Transparency test)
On the concealment rate test paper, the prepared water-based paint is applied with a film applicator so that the applied thickness is 0.15 mm, and cured at a temperature of 23 ° C. and a humidity of 50% RH for 48 hours. Got. The visual reflectance of the black ground coating film and the white ground coating film in the prepared specimen was measured using a color difference meter “CR-300” (manufactured by Minolta Co., Ltd.), and the concealment ratio was calculated. Transparency evaluation was evaluated as follows according to the value of the concealment rate. The results are shown in Table 2.
◎: Concealment rate is less than 5% ○: Concealment rate is 5% or more and less than 10% △: Concealment rate is 10% or more and less than 15% ×: Concealment rate is 15% or more

(Water resistance test)
The prepared water-based paint was applied onto a glass plate (200 mm × 150 mm × 5 mm) with a film applicator so that the applied thickness was 0.15 mm, and a test specimen was prepared. The prepared specimen was cured at a temperature of 23 ° C. and a humidity of 50% RH for 48 hours, and then the surface condition was evaluated visually after being immersed in water at 50 ° C. for 72 hours. The evaluation is as follows.
◎: No abnormality ○: Almost no abnormality △: Some whitening of the coating film was observed ×: Whitening of the coating film was observed

(Contamination test)
On the slate plate (300 mm x 150 mm x 3 mm), the prepared water-based paint was applied with a spray gun so that the application amount was 0.25 kg / m ^2, and the temperature was 23 degrees and the humidity was 50% RH. The specimen was cured for 48 hours.
The prepared test specimen was installed in Ibaraki City, Osaka Prefecture so as to face the south side, exposed outdoors, and visually evaluated for the presence or absence of stains after 3 months. The evaluation is as follows. The results are shown in Table 2.
◎: No dirt ○: Almost no dirt △: Some dirt such as rain streak contamination was seen ×: Dirt was seen on the whole specimen

(Wear resistance test)
On the slate plate (300 mm x 150 mm x 3 mm), the prepared water-based paint was applied with a spray gun so that the application amount was 0.25 kg / m ^2, and the temperature was 23 degrees and the humidity was 50% RH. The specimen was cured for 48 hours.
Using the super UV tester (manufactured by Iwasaki Electric Co., Ltd.) as an accelerated weathering tester, the prepared test specimens were tested up to 50 cycles with 6 hours of light irradiation and 2 hours of condensation (8 hours in total) as one cycle. The evaluation was performed by measuring the hue change (ΔE) around 50 cycles. The evaluation is as follows. The results are shown in Table 2.
◎: ΔE is less than 2 ○: ΔE is 2 or more and less than 5 Δ: ΔE is 5 or more and less than 10 ×: ΔE is 10 or more

Claims (4)

(A) synthetic resin emulsion,
(B) resin beads having a specific gravity of 1.0 to 1.5,
(C) A water-based matte coating composition having transparency, comprising a wax having a specific gravity of 0.7 or more and less than 1.0. (A) For 100 parts by weight of the solid content of the synthetic resin emulsion,
(B) 1-100 weight part of resin beads (C) 1-100 weight part of wax is contained, The water-based matte coating composition of Claim 1 characterized by the above-mentioned.   (C) Wax is wax emulsion, The water-based matte coating composition of Claim 1 or Claim 2 characterized by the above-mentioned. The coating method characterized by apply | coating the water-based matte coating composition in any one of Claims 1-3 to the base material surface which has an unevenness | corrugation.