JP3180287B2 - Multi-color paint composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-in-water type colorful paint composition and, more particularly, to a colorful paint composition in which a plurality of colors are compounded in one coating by dispersing an enamel having a pigment dispersed in an aqueous phase. The present invention relates to a multi-color paint composition which can express a rich design feeling, and is excellent in low odor during coating, weather resistance of a formed film, and water resistance. The composition of the present invention is applicable to painting inside and outside buildings, vehicles, bridges, ships, home appliances, cardboard, plastic containers, office machines, furniture, woodwork, and the like.

[0002]

2. Description of the Related Art Conventionally, a paint that forms a variety of design coating films by one coating is called a multicolor paint.
It is specified in JIS K 5667. Above all, oil-in-water type multi-color paints in which a colored organic solvent-based enamel is dispersed as a discontinuous phase in a water-based dispersion medium to a size that can be discriminated are described in, for example, J. Am. C. It has been put into practical use by ZORA in Japanese Patent No. 231698, and is widely used in Japan. However, since many conventional multi-pattern paints use nitrocellulose, polyvinyl toluene, polybutadiene, etc. as a base resin, when used outdoors such as building exteriors, the formed coating film may be discolored or choked. Poor weather resistance, its use was mainly for architectural interiors. Further, the organic solvent used for dissolving these base resins also has a relatively high SP (solubility parameter) value and a low boiling point. Therefore, the present inventors have studied using a styrene-acrylic copolymer or the like as a base resin in order to improve weather resistance, but as an enamel, stabilization after dispersion in water could not be achieved, and it could not be put to practical use. .

[0003]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a copolymer having a specific monomer concentration, an acid value, and a weight average molecular weight is used as an enamel resin. As a result, the present inventors have found that the enamel dispersed phase can be stabilized, and that both the storage stability of the paint and the weather resistance of the coating film can be achieved, thereby completing the present invention. Thus, according to the present invention, "1. Styrene 10 to 30% by weight, acrylic monomer
-50 to 90% by weight, and other monomers 0 to 40 weight
% Of a copolymer having a weight average molecular weight of 20,000 to 200,000 and an acid value of less than 1 ; a pigment (B); and an organic solvent (C). A multi-color paint composition comprising a mixture of components as a component to form an enamel and one or more enamel-dispersed particles obtained by dispersing the composition in an aqueous dispersion medium. 2 . 2. The multi-color paint composition according to item 1, wherein the glass transition temperature of the copolymer (A) is from 0 to 80 ° C. 3 . SP value by all acrylic monomers used in the copolymer (A) is a 7.6 to 8.6, item 1 or
Other multicolor paint composition described in item 2. 4 . The content of the organic solvent (C) in the enamel is 20 to 7
4. The multi-color paint composition according to any one of items 1 to 3 , which is 0% by weight. 5 . 5. The colorful pattern paint composition according to any one of items 1 to 4 , wherein the specific gravity of the enamel is 0.9 to 2.5. About.

[0004]

BEST MODE FOR CARRYING OUT THE INVENTION Copolymer (A) used in the present invention
Is styrene 10 to 30% by weight, acrylic monomer 5
0-90% by weight, and other monomers 0-40 wt%
Obtained by copolymerizing a monomer mixture containing, in weight average molecular weight 20,000 to 200,000, a copolymer of acid value of less than 1. Examples of the acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. , Lauryl (meth) acrylate, isobornyl (meth) acrylate and other acrylic or methacrylic acid having 1 to 1 carbon atoms
24 alkyl esters or cycloalkyl esters and the like, and one kind or a mixture of two or more kinds is used. In addition, carboxyl group, hydroxyl group, amide group,
An acrylic monomer having a hydrophilic functional group such as an amine group may be used in combination with the above-mentioned monomers in a small amount as long as the stability of the enamel-dispersed particles is not impaired.

Further, as other monomers, for example,
Vinyl aromatic compounds such as α-methylstyrene, vinyltoluene, α-chlorostyrene; vinyltrimethoxysilane, vinyltriethoxysilane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth)
Alkoxysilyl group-containing monomers such as acryloyloxypropyldimethoxymethylsilane; perfluoroalkyl (meth) acrylates such as perfluorobutylethyl (meth) acrylate, perfluoroisononylethyl (meth) acrylate, and perfluorooctylethyl (meth) acrylate CF2 = CF2, CHF = CF
2, a general formula CX such as CH2 = CF2, CC1F = CF2
2 = CX2 (where X is the same or different and H, C
1, Br, F, an alkyl group or a haloalkyl group. However, the formula contains at least one F. )
And the like. Examples of the monomer which can be copolymerized with the styrene and the acrylic monomer described above are shown below . These can be appropriately selected and used according to desired physical properties.

The copolymer used in the present invention can be obtained by copolymerizing the above monomer mixture in the presence of a radical polymerization initiator by a conventional method such as a solution polymerization method. Examples of the radical polymerization initiator include benzoyl peroxide, t-butyl hydroperoxide, cumyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, t-butylperoxybenzoate, lauryl peroxide, acetyl peroxide, and t-butyl peroxide. Peroxides such as butylperoxy-2-ethylhexanoate; α, α′-azobisisobutyronitrile, α, α′-azobis-2-methylbutyronitrile,
Examples include azo compounds such as azobisdimethylvaleronitrile and azobiscyclohexanecarbonitrile.

Solvents used in the polymerization include, for example, aliphatic hydrocarbons such as petroleum benzene, mineral spirits and terpenes; aromatic hydrocarbons such as benzene, toluene and xylene; alicyclic hydrocarbons such as cyclohexane; Other dichloroethane, trichlene, Texanol, Texanol isobutyrate, 2-ethylhexyl alcohol, diisobutyl ketone, 2-ethylhexyl acetate, dibutyl phthalate, dioctyl phthalate and the like having a low affinity for water can be used alone or in combination, preferably From the viewpoint of the working environment at the time of coating, an aliphatic hydrocarbon solvent is preferred. When a poor solvent such as an aliphatic hydrocarbon-based solvent is used as the solvent used in the polymerization, the SP (solubility parameter) value of the monomer mixture used in the above is used as a measure of hydrophilicity in order to obtain good enamelling. It is desirable to appropriately adjust the SP value, and the SP value of the acrylic monomer used is preferably 7.6 to 8.6, and more preferably 7.8 to 8.4, because it is affected by a monomer having high hydrophilicity. It is desirable to select the acrylic monomers to be used so as to be within this range.

Here, the SP (solubility parameter) value is calculated from the SP value of each monomer by the following equation. SP value = δ δ × 100 = (δ a × A) + (δ b × B) + (δ c ×
C) + ... (wherein δ _a , δ _b , δ _c ,..., ...) indicate the SP values of monomers _a , _b , _c ,.
... Indicate the weight% of the monomers (a), (b), (c), (...) In the total amount of the (acrylic) monomers used. S of each monomer
P value is J. Paint Tech. , 42 (541),
176 (1970) and the like. ) The copolymer (A) is preferably styrene 10 from the viewpoint of water resistance.
30 wt%,及Beauty acrylic monomer 50-90
%, And 0 to 40% by weight of other monomers.
It is a copolymer of a nomer mixture .

The copolymer (A) has a weight average molecular weight of 2
0000 to 200,000, preferably 50,000
１５０150,000. If the molecular weight is less than 20,000, the weather resistance of the coating film and the stability of the enamel-dispersed particles in the coating material will decrease, while if it exceeds 200,000, the coating workability and the film-forming property will be poor. Copolymer (A)
Is a copolymer having an acid value of less than 1. When the acid value exceeds 1 , the stability of the enamel-dispersed particles is significantly reduced, which is not preferable. Further, the copolymer (A) preferably has a glass transition temperature (Tg) of 0 to 80 ° C., preferably 10 to 60 ° C. If the Tg is less than 0 ° C., the stability of the enamel-dispersed particles and the coating If the water resistance exceeds 80 ° C., the film-forming property is reduced and the coating film becomes brittle, which is not preferable.

As the pigment (B) used in the present invention, conventionally known coloring pigments and extender pigments can be used. Examples of coloring pigments include titanium oxide, carbon black, red iron oxide, iron oxide, phthalocyanine blue and phthalicyanine. Green, benzimidazolone, azo pigments, quinacridone red, graphite, chromium oxide, ultramarine, pearl pigments, metal powders, and the like.Examples of the extender pigments include, for example, tanker, clay, talc, barium sulfate, white carbon, alumina, Bentonite, silica, mica, etc., can be used alone or in combination. The content of these pigments in the enamel can be appropriately selected depending on the intended design and the like, but is desirably 70% by weight or less, preferably 50% by weight or less. If the content is more than 70% by weight, the mechanical strength of the enamel is decreased, and the stability of the enamel-dispersed particles and the suitability for spraying during coating are unfavorably reduced. If it exceeds 50% by weight, the specific gravity and viscosity of the enamel are reduced. It is not desirable because adjustment of the image is likely to be inconvenient.

The organic solvent (C) used in the present invention
As the known ones, for example, petroleum benzene, mineral spirits, aliphatic hydrocarbons such as terpenes, benzene, toluene, aromatic hydrocarbons such as xylene, alicyclic hydrocarbons such as cyclohexane, Other dichloroethane, trichlene, texanol, texanol isobutyrate, 2-ethylhexyl alcohol, diisobutyl ketone, 2-ethylhexyl acetate, dibutyl phthalate, dioctyl phthalate, methanol, ethanol, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone and the like. These can be used alone or as a mixture, and aliphatic hydrocarbon solvents are preferred from the viewpoint of the working environment during coating. The content of the organic solvent (C) in the enamel is 2
0-70% by weight is preferred. If it is less than 20% by weight, adjustment of the specific gravity and viscosity of the enamel tends to be inconvenient, while if it exceeds 70% by weight, the mechanical strength of the enamel decreases, and the stability of the enamel-dispersed particles and the suitability for spraying during coating decrease. It is not desirable because of fear.

In the present invention, the copolymer (A) obtained as described above, the pigments including the color pigment (B) and the organic solvent (C) are dispersed in a disperser such as a disperser, a sand mill, a roll mill, and a ball mill. The mixture is mixed and dispersed according to an ordinary method such as the use of an enamel. At this time, if necessary, additives such as a dispersant, an antifoaming agent, and a plasticizer may be appropriately added to the composition. The specific gravity of the enamel obtained as described above, from the viewpoint of the stability of the enamel dispersed particles in the coating,
A range of 0.90 to 2.5, preferably 0.95 to 1.5 is appropriate. Outside this range, the dispersed particles float or settle during the storage of the coating and are liable to be fused, which is not preferred. The viscosity of the enamel is appropriately determined depending on the intended design.
Pa · s or more is preferable.

The composition of the present invention contains one or more kinds of enamel dispersed particles obtained by dispersing the above enamel in an aqueous dispersion medium. As the aqueous dispersion medium, conventionally known ones can be used, and examples thereof include those in which a stabilizer that stabilizes dispersed particles so as not to aggregate with each other is appropriately mixed with water. As such a stabilizer, either an organic stabilizer or an inorganic stabilizer can be used. In particular, a stabilizer which is water-soluble and has a moderately hydrophobic portion is suitable. Such stabilizers include known protective colloids, such as methylcellulose,
Ethyl cellulose, polyvinyl alcohol, casein,
Tragant gum, carbarium rubber, cellulose acetate phthalate, bentonite, hydroxyethyl cellulose, polymethacrylic acid, gum arabic, karaya gum, gelatin, sodium alginate, albumin, pectin, xanthan gum, starch, water-soluble urea formaldehyde and the like can be used. In addition, relatively water-insoluble salts, such as clay, talc, barium sulfate, calcium carbonate, magnesium carbonate, diatomaceous earth and the like may be used as the stabilizer, but a larger amount is used for stabilization as compared to the water-soluble stabilizer. Therefore, it is desirable to use as fine a powder as possible at the time of use. The aqueous dispersion medium further includes:
If necessary, an electrolyte (sodium chloride, sodium sulfate, magnesium sulfate, etc.), a wetting agent, a film forming aid, an antifreezing agent, an antifoaming agent, a dye, etc. are appropriately added to such an extent that the stability of the dispersed particles is not impaired. You may. The aqueous dispersion medium is preferably 45 to 9 from the viewpoint of coating workability and stability of dispersed particles.
It is desirable to adjust to about 0 (KU value).

In the method of dispersing the enamel in the aqueous dispersion medium, the mixing ratio of the enamel to the aqueous dispersion medium is from 1.5 to 1.5.
Conventionally known methods using an ordinary mixing and dispersing apparatus can be adopted by mixing to about 0.3, but preferably an apparatus having, for example, a two-bladed propeller type stirrer capable of mixing the whole with a small shearing force It is desirable to use When dispersing the enamel in the aqueous dispersion medium, each enamel required for the intended design is separately dispersed, and the resulting aqueous dispersions are mixed to form a paint, or the enamels of each color are simultaneously dispersed in the aqueous dispersion. It can be mixed and dispersed in a medium to form a coating material. Generally, the former method is generally used from the viewpoint of pattern color reproducibility.

The particle size of the enamel-dispersed particles obtained as described above is suitably about 0.1 mm or more from the viewpoint of pattern properties. The particle size can be selected according to the intended design by appropriately adjusting the enamel composition and viscosity, the type and amount of the stabilizer in the aqueous dispersion medium, and the like. Further, the enamel-dispersed particles are not necessarily spherical, and may be elliptical, teardrop-shaped, or the like. The composition of the present invention contains one or more of the above-mentioned enamel-dispersed particles, and can be obtained by mixing several types of enamel aqueous dispersions depending on the intended design. The composition of the present invention can be applied by a usual coating method, for example, spray, roller, brush coating, etc., and particularly, air spray, HVLP (High Volume)
Spray coating such as “me Pressure” is preferable because it can be applied in a uniform pattern with little deformation of the enamel dispersed particles.

[0016]

The present invention will be described more specifically with reference to the following examples.

Production of Copolymer (A) Production Example A A reactor was equipped with a thermometer, a thermostat, a stirrer, a reflux condenser, and a dropping pump. 45 parts by weight of mineral spirit were charged and the temperature was raised to 100 ° C. while stirring. After doing
100.4 parts by weight of a mixture of the monomer and the polymerization initiator t-butylperoxy-2-ethylhexanoate shown in Table 1 was kept in a reactor maintained at 100 ° C. for 3 hours using a dropping pump. Dropped at a rate. 2 hours after dropping 100
C. and kept stirring. Then, an additional polymerization initiator (t-butylperoxy-2-ethylhexanoate)
A solution prepared by dissolving 0.5 part by weight of mineral spirit in 30 parts by weight was dropped at a constant rate over 1 hour, and the reaction was terminated at 100 ° C. for 1 hour, followed by dilution with 48.8 parts by weight of mineral spirit. The obtained copolymer solution was a uniform and transparent solution having a nonvolatile content of 45% by weight. Also,
The weight average molecular weight of this copolymer was 98,000 and Tg was 45 ° C. Production Examples B to I In Production Example 1, the same procedure as in Production Example 1 was carried out except that the mixture of the monomer and the polymerization initiator was used in the composition shown in Table 1 and the reaction solvent type shown in the table was used. A combined solution was obtained.
The property values of the obtained copolymer and copolymer solution are shown in the same table.

[0018]

[Table 1]

(Note) In the reaction solution in Table 1, M is mineral spirit and X is xylene.

Preparation of Enamel Aqueous Dispersion For each of the copolymer solutions A to I obtained in the above production examples,
A copolymer solution, a pigment and a solvent were charged into a stainless steel container having a capacity of 2 liters according to the composition shown in Table 2, and the mixture was stirred for 15 minutes.
After stirring for minutes, the mixture was dispersed using glass beads with a desktop sand mill for 15 minutes to produce enamels of white, yellow, red, black, and blue, respectively. Then, 100 parts by weight of tap water, 0.5 part by weight of methylcellulose, 0.1 part by weight of Sluroff 72N (* 1) and 0.1 part by weight of BYK-025 (* 2).
The enamel 1 obtained above was added to 1 part by weight of the aqueous dispersion medium.
100 parts by weight, and the mixture was stirred at low speed with a propeller type stirrer.
Stir for 5 minutes, the size of the enamel dispersed particles is 1-2 mm
And aqueous dispersions of white, yellow, red, black, and blue enamels were prepared for each of the copolymers A to I. (Note 1) Sluroff 72N: Preservative manufactured by Takeda Pharmaceutical Co., Ltd. (Note 2) BYK-025: manufactured by Big Chemie, defoamer

[0021]

[Table 2]

Production of multi-pattern paints Examples 1-4 and Comparative Examples 1-8 The whites prepared above for each of the copolymers A to I,
Aqueous dispersions of enamels of yellow, red, black, and blue were mixed with each other for the same copolymer to obtain white / yellow / red / black / blue = 60/10/10/1.
The mixture was mixed at a mixing ratio of 0/10 to obtain colorful paints A to I. Further, an aqueous dispersion of yellow, red, black, and blue enamels based on the copolymer B is mixed with a white enamel aqueous dispersion based on the copolymer A by white / yellow / red / black / blue = 60/10/10 / 10
The mixture was mixed at a mixing ratio of / 10 to obtain a multi-color pattern paint J. In addition, "Zoracoat No. 229" (manufactured by Kansai Paint Co., Ltd.,
Nilot cellulose-based multi-color paints) and Zolatone N
o17911SU "(manufactured by Kansai Paint Co., Ltd., vinyl toluene resin-based multi-colored paint).
And Table 3 shows the paint condition and the test results of the coating film performance for these paints.

[0023]

[Table 3]

(Note) In Table 3, "-" indicates that the test was not possible.

The test method is as follows. (1) State of paint (storability) Immediately after production of paint, after leaving it at room temperature for 24 hours, and after leaving it at 40 ° C. for one month, the paint in the container is stirred lightly to the extent that the enamel-dispersed particles do not collapse. The condition was observed. ◎: No fusion between particles ○: Some fusion between particles is observed ×: Fusion between particles is considerably observed (2) Odor and pattern at the time of coating Each paint is tinplated with a spray gun 300-400 on board
The odor when coated at a coating amount of g / m ² was evaluated according to the following criteria. ◎: Low odor, no odor during coating. は: Low odor at coating, but odor remains in coating film after 1 to 2 weeks after coating. ×: Smell, organic mask at coating. In addition, the pattern properties of the coating film after the above coating were visually evaluated according to the following criteria. ：: The pattern of the particles is clear, and the pattern can be identified even from a place 5 m away. 部分: A small portion of the pattern of the particles is seen, and the pattern is difficult to identify from a place 5 m away. Δ: The pattern is broken. , A considerable linear pattern is observed. ×: The pattern is completely collapsed and no particle pattern is observed. (3) Weather resistance A 70 × 150 × 4 mm slate plate is provided with “Allele Holder G” (Kansai Paint Co., Ltd.) And an aqueous base conditioner) were coated with a roller so as to have an application amount of 800 to 1,000 g / m ^2, and dried at room temperature for 7 days to obtain a test plate, on which each coating material was applied at an application amount of 300 to 400 g / m 2. ^2, and dried at room temperature for 7 days to prepare a test coated plate. About each obtained test coated plate, the state of the coating film surface after 250 hours and 1000 hours of testing with a sunshine weatherometer was visually evaluated. ：: No cracks or peeling on the coating film surface, and no discoloration or whitening (chalking) was observed. ：: Slight discoloration or whitening was recognized on the coating film surface. X: Cracking or peeling on the coating film surface, or significant discoloration or whitening. (4) Heating / cooling cycle The test coated plate prepared in the same manner as in (3) was subjected to JIS A
According to the hot / cold repetition test of 6909, <10 hours of immersion in water-cooling for 3 hours in a thermostat at -20 ° C to heating for 5 hours in a thermostat at 50 ° C> as one cycle The state of the coating surface was visually evaluated. ：: No cracks or peeling on the coating surface and no discoloration is observed. ○: Some cracks, peeling or discoloration are recognized on the coating surface. ×: Any of cracks, peeling or discoloration on the coating surface. Remarkably recognized

[0026]

According to the present invention, it is possible to obtain a multicolor paint composition which can stabilize the enamel-dispersed particles, and has excellent storage properties, low odor during coating, and excellent weatherability and water resistance of the formed film. , 1
A multi-colored coating film having a variety of design feelings in which a large number of colors are combined can be easily obtained by multiple coatings.

Continuation of the front page (72) Inventor Nobuge Numa 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Pref. Kansai Paint Co., Ltd. (56) References JP-A-6-3299961 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 5/29

Claims (5)

(57) [Claims] (1) Styrene 10 to 30% by weight, acrylic
50 to 90% by weight of monomer and 0 to other monomer
A copolymer (A) having a weight average molecular weight of 20,000 to 200,000 and an acid value of less than 1 , a pigment (B), and an organic solvent (C) obtained by copolymerizing a monomer mixture containing 40% by weight. A multi-color paint composition comprising: a mixture comprising a main component mixed and dispersed into an enamel; and one or more enamel dispersion particles obtained by dispersing the enamel in an aqueous dispersion medium. 2. The copolymer (A) has a glass transition temperature of from 0 to 2.
The multi-color paint composition according to claim 1, which is at 80C. SP value by all acrylic monomers used to 3. A copolymer (A) is a 7.6 to 8.6, according to claim 1 or multicolor paint compositions described in 2. Content in enamel wherein the organic solvent (C) is 20 to 70 wt%, multicolor paint composition according to any one of claims 1 to 3. 5. The specific gravity of the enamel is 0.9 to 2.5, according to claim 1 to multicolor paint composition described in any one of four.