JP2009074042A - Water paint composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water paint composition that provides good pallet washability. <P>SOLUTION: The water paint composition contains at least water; a water-soluble resin; and a composite pigment with calcium carbonate and an organic pigment attached thereto. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a water-based paint composition suitably used for watercolor paints, poster colors and the like.

In general, water-based paint compositions such as watercolor paints and poster colors are compositions containing water, a water-soluble resin, and a coloring material, and are used when painting on paper or the like. When coloring, usually paint is taken out from a container such as a tube to a palette and mixed with other colors of paint or water, and applied to paper using a brush.
In Patent Document 1, a paint film can be removed during washing while maintaining the paintability, and a paint film having water resistance and weather resistance is formed. An aqueous paint composition containing spherical colored resin particles having an average particle diameter of 3 to 20 μm which are difficult to enter and using a heat-crosslinkable water-soluble resin as a fixing agent is described.
JP 2002-265872 A

The palette that serves as a saucer for placing the paint on the brush is often white so that the color when the paper is colored can be confirmed. In particular, in the case of transparent watercolor paint, since the transmitted light of the background is also seen, it is difficult to distinguish the color of the paint when the palette is chromatic. In the case of an opaque paint, it is difficult to be influenced by the color of the background, but it can be said that a uniform color is preferable. In any case, if the color of the paint placed on the palette last time is left, it may be mixed with the paint of a new color or may appear to be mixed. Usually, a palette of watercolor paints is repeatedly used after being used and washed with water to remove the aqueous paint composition. However, even after washing with water, the pigment remains as if the pallet was thinly dyed, and it may not be possible to return to the state before use. This is because the pigment enters the irregularities when molded on the surface of the pallet and the scratches attached to the pallet during repeated use, and is fixed by a fixing component such as a water-soluble resin contained in the aqueous paint composition.
In particular, when organic pigments with good color development and many types of colors are used, organic pigments have a small particle size and many oleophilic properties, so they adhere to the pallet surface together with water-soluble resins. In this case, the water at the time of washing is repelled, so that the dissolution of the water-soluble resin is hindered and the pallet becomes difficult to remove. In addition, if the organic pigment is first treated with a surfactant to make the organic pigment hydrophilic, the surfactant acts as a bridge between the palette and the organic pigment even if the water-soluble resin dissolves. For this reason, the organic pigment may not leave the pallet and may further contaminate the pallet.
On the other hand, if the particle diameter of the pigment as the colorant is increased, the pigment does not enter the concavo-convex portion of the pallet and the stain becomes difficult to adhere, but there is a problem that the color development when painted is worsened.

  That is, the gist of the present invention is an aqueous paint composition containing at least water, a water-soluble resin, and a composite pigment obtained by adhering calcium carbonate and an organic pigment.

The composite pigment used in the present invention is in a state in which the surface of calcium carbonate is covered with the organic pigment while voids are formed. Such particles have the properties of both lipophilic organic pigment and hydrophilic calcium carbonate on the surface, and are less lipophilic than the organic pigment alone, making it difficult to repel water, It is presumed that the fixing power to the pallet can be weakened because water is contained in the voids due to the organic pigment and the water-soluble resin or the like that has fixed the pigment on the pallet is easily dissolved.
At this time, if a porous material such as silica is used as the material to be attached to the organic pigment, silica absorbs and retains water that dissolves the water-soluble resin, so that the water-soluble resin is not sufficiently dissolved. In addition, materials such as talc and mica are cleaved by an impact when compounded with an organic pigment, and thus may not be sufficiently compounded.
In addition, since the organic pigment is fixed on the surface of calcium carbonate, the particle size of the organic pigment alone remains fine, so that it is possible to obtain the same color developability as when using the organic pigment alone when painting. .

  Water is used as the main solvent in the aqueous paint composition.

  The water-soluble resin is used as a fixing agent and a color developing agent. Handwriting by the aqueous paint composition of the present invention or providing a film-forming ability after coating, imparting adhesion performance to the writing surface and coated surface, imparting viscosity to the aqueous paint composition, and pigment dispersion stability Used for the purpose of imparting sex. Specifically, natural water-soluble resins such as glue, gum arabic, and dextrin, semi-synthetic water-soluble resins such as carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose, and synthetic water-soluble resins such as polyvinyl alcohol and acrylic resins are used. it can.

  Here, cellulose semisynthetic resins such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and the like are made by ether-bonding other substituents to the hydroxyl group of wood cellulose, and carboxymethylcellulose is the same as CMC Daicel 1120. 1140, 1170, 1190, 2260, 1290, 1380 (manufactured by Daicel Industries, Ltd.), serogen 5A, serogen 7A (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Examples of hydroxyethyl cellulose include HEC Daicel SP900, SP600, SP400, and SP200 (manufactured by Daicel Industries, Ltd.), Tyroze H300P, H4000P, and 10,000P (manufactured by Clariant Polymer Co., Ltd.). Examples of hydroxypropylcellulose include Nisso HPC-SSL, SL, L, M, and H (manufactured by Nippon Soda Co., Ltd.).

  Polyvinyl alcohol is a water-soluble synthetic resin obtained by saponifying polyvinyl acetate with alkali and acid, and commercially available products include Gohsenol GH-23, GH-20, GH-17, and GH-17. GM-14, GM-14L, GL-05, GI-03, KH-20, KH-17, KM-11, KL-05, KP-08, KP-06, NK-05 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Kuraray Poval PVA203, PVA205, PVA210, PVA217, PVA220, PVA224, PVA235, PVA217E, PVA217EE, PVA220E, PVA224E, PVA403, PVA405, PVA420, PVA420H (above, manufactured by Kuraray Co., Ltd.), J Pova JP-04, JP-05, JP-10, JP-15, JP-18, JP-20, JP-24, JP-33, VP-18, JP-05S, JP-18S (above, Nippon Vinegar Poval Co., Ltd.) can be exemplified.

  Furthermore, acrylic resins are those obtained by polymerizing acrylic acid and its derivatives into acid-terminated alkali salts that are soluble in water. Specifically, methyl methacrylate, methyl acrylate, ethyl acrylate, methacrylate Examples thereof include esters such as ethyl acrylate, isopropyl acrylate, isopropyl methacrylate, butyl acrylate, and butyl methacrylate, copolymers obtained by combining the acrylate and methacrylate esters, and styrene-acrylate copolymer systems. Specifically, Glass Call LS40, LS41, LS23, HA2, HA2, HN2 (all manufactured by Allied Colloid Ltd., UK), John Crill 62, 61J, 354, 501 (all Johnson ( (Made by Co., Ltd.). These resins can be used alone or in combination of two or more. The amount of the active ingredient used is preferably 1 to 20% by weight based on the total amount of the aqueous paint composition.

The composite pigment is used as a colorant for an aqueous paint composition. The composite pigment is obtained by attaching an organic pigment to the surface of calcium carbonate, and the coverage is preferably 10% or more and 90% or less. The coverage is the ratio at which the surface of calcium carbonate is covered with an organic pigment. The coverage is determined using a scanning electron microscope. As a measurement method, 50 or more scanning electron micrographs of the composite pigment at a magnification of 5000 are taken at random, and the area of calcium carbonate particles from the photograph and the total area of the organic pigment covering the calcium carbonate are calculated to calculate the coverage. To do. The coverage is based on the area, and is obtained from the projected area even when the aggregated particles of the organic pigment adhere to the calcium carbonate in layers. If it is difficult to distinguish between calcium carbonate and organic pigment from the composite pigment photograph, prepare each particle before compounding, and measure the particle shape and particle diameter by photographing with the composite pigment and scanning electron microscope. And clarify.
If the particle size of the organic pigment used at this time is too large, the organic pigment may not adhere to the surface of calcium carbonate. Therefore, the particle size of the organic pigment is preferably 1/3 or less of the particle size of calcium carbonate.

  Conventionally known organic pigments may be attached to the surface of the composite powder. For example, Hansa Yellow-10G, 5G, 3G, 4, GR, A, G, Benzidine Yellow, Permanent Yellow NCG, Quinoline Yellow, Sudan 1, Permanent Orange 2G, Indanthrene Brilliant Orange GK, Vulcan Orange, Benzidine Orange HL, pyrazoline orange TMP, perinone orange, DPP orange, permanent brown FG, para brown, permanent red 4R, fire red, brilliant carmine BS, pyrazolone red, quinacridone red, Bordeaux 5B, thioindigo red, naphthol carmine HR , Nafsol Red F5RK, Nafsol Red F3RK-70, Permanent Red FGR, Permanent Carmine FB, Permanent Red 2B, Brilliantca Min 6B, perylene vermilion, perylene red, DPP Red, Fast Violet B, dioxazine violet, quinacridone magenta, alkali blue lake, copper phthalocyanine blue, indigo, Indus Ren blue, acid green lake, there is a copper phthalocyanine green and the like. These pigments may be used alone or in combination of two or more. The amount used is preferably 1% to 70% of the composite pigment, and the composite pigment is preferably 0.1% to 40% by weight as the aqueous paint composition.

  The method for producing the composite pigment can be produced by a conventionally known method and is not limited by the present invention. For example, calcium carbonate and organic pigments are pulverized with a small pulverizer, the pulverized product is filled with alumina sintered balls in an alumina pot, and dry-processed with a centrifugal ball mill, or dry-processed with a Henschel mixer. It is done.

  As composite pigments, commercially available products are Blue # 2400 (composite pigment composed of copper phthalocyanine blue, calcium carbonate, silica, dioxin violet and aluminum silicate), and Blue # 2500 (copper phthalocyanine blue, calcium carbonate, alumina silicate and naphthol carmine HR). Composite pigment comprising), viridangulin P (copper phthalocyanine green, copper phthalocyanine blue, Hansa Yellow 10G, composite pigment comprising calcium carbonate, kaolin, silica), FS / NR418 (copper phthalocyanine blue, copper phthalocyanine green, calcium carbonate, aluminum Composite pigment composed of silicate) (above, manufactured by Noma Chemical Co., Ltd.), NSBA-25 (composite pigment composed of copper phthalocyanine blue, calcium carbonate) (above Dainichi Kogyo Co., Ltd.) and the like.

  In addition to the above components, various components can be blended as necessary. Phenol, chloroacetamide, 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 2-pyridinethiol-1 -Oxide sodium salt, sodium dehydroacetate, sodium benzoate, sodium sorbate, potassium sorbate, thiabendazole, phenoxyethanol, sodium fluoride, 4- (2-nitrobutyl) morpholine, 1,3-dimorpholino-2-ethyl-2 -Preservatives and fungicides such as nitripropane and 2-bromo-2-nitropropane-1,3-diol, colored pigments, and white pigments as extender pigments, rust preventives, defoamers, and defoamers Of course, it can be used in combination with a surfactant or the like.

  The aqueous paint composition of the present invention can be easily obtained by mixing and dispersing the above components with a conventionally known stirring and dispersing machine such as a turbo mixer, a Henschel mixer, a three-roll mill, a horizontal ball mill, or a horizontal bead mill. .

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to an Example.

Preparation of composite pigment 1 (coverage 12%) C.I. I. Pigment Blue 15: 3 (average particle size 0.02 μm)
20 parts by weight C.I. I. Pigment Violet 23 (average particle size 0.20 μm) 3 parts by weight Calcium carbonate (average particle size 1.6 μm, oil absorption 30 ml / 100 g) 65 parts by weight The above components were pulverized with a small pulverizer, and the pulverized product was placed in an alumina pot. It was filled with alumina sintered balls and processed with a ball mill to obtain a composite powder.

Preparation of composite pigment 2 (60% coverage) C.I. I. Pigment Green 7 (average particle size 0.03 μm) 2 parts by weight C.I. I. Pigment Yellow 3 (average particle size 0.56 μm) 2 parts by weight Calcium carbonate (average particle size 3.0 μm, oil absorption 40 ml / 100 g) 40 parts by weight Arabic gum powder 20 parts by weight The above ingredients are mixed with a Henschel mixer to obtain a composite powder. Obtained.

Preparation of composite pigment 3 (coverage 87%) C.I. I. Pigment red 48: 3 (average particle size 0.03 μm) 2 parts by weight C.I. I. Pigment Orange 16 (average particle size 0.50 μm) 2 parts by weight C.I. I. Pigment Yellow 1 (average particle size 0.38 μm)
0.1 parts by weight Calcium carbonate (average particle size 3.0 μm, oil absorption 40 ml / 100 g) 30 parts by weight Gum arabic powder 7 parts by weight The above components were mixed with a Henschel mixer to obtain a composite powder.

Preparation of composite pigment 4 (coverage 12%) C.I. I. Pigment Green 7 (average particle size 0.03 μm) 2 parts by weight C.I. I. Pigment Yellow 3 (average particle diameter 0.56 μm) 2 parts by weight Calcium carbonate (average particle diameter 1.8 μm, oil absorption 30 ml / 100 g) 40 parts by weight Arabic gum powder 20 parts by weight Was filled together with alumina sintered balls in an alumina pot and processed with a ball mill to obtain a composite powder.

Preparation of composite pigment 5 (coverage 55%) C.I. I. Pigment red 48: 3 (average particle size 0.03 μm) 2 parts by weight C.I. I. Pigment Orange 16 (average particle size 0.50 μm) 2 parts by weight C.I. I. Pigment Yellow 1 (average particle size 0.38 μm)
0.1 parts by weight Calcium carbonate (average particle size 1.8 μm, oil absorption 30 ml / 100 g) 30 parts by weight Arabic gum powder 7 parts by weight The above components were mixed with a Henschel mixer to obtain a composite powder.

Preparation of composite pigment 6 (coverage 85%) C.I. I. Pigment Yellow 3 (average particle size 0.60 μm) 1 part by weight C.I. I. Pigment Yellow 1 (average particle diameter 0.38 μm) 2 parts by weight Calcium carbonate (average particle diameter 1.8 μm, oil absorption 30 ml / 100 g) 30 parts by weight The above components were mixed with a Henschel mixer to obtain a composite powder.

Preparation of composite pigment 7 (coverage 6%) C.I. I. Pigment Blue 15: 3 (average particle size 0.02 μm)
15 parts by weight C.I. I. Pigment Violet 23 (average particle size 0.20 μm)
2.5 parts by weight Calcium carbonate (average particle size 1.6 μm, oil absorption 30 ml / 100 g) 65 parts by weight The above components were pulverized with a small pulverizer, and the pulverized product was filled with alumina sintered balls in an alumina pot. A composite powder was obtained by treatment with a ball mill.

Preparation of composite pigment 8 (coverage 96%) C.I. I. Pigment Blue 15: 3 (average particle size 0.02 μm)
30 parts by weight C.I. I. Pigment Violet 23 (average particle diameter 0.20 μm) 5 parts by weight Calcium carbonate (average particle diameter 1.6 μm, oil absorption 30 ml / 100 g) 65 parts by weight The above components were mixed with a Henschel mixer to obtain a composite powder.

Preparation of composite pigment 9 (coverage 5%) C.I. I. Pigment Green 7 (average particle size 0.03 μm) 1.5 parts by weight C.I. I. Pigment Yellow 3 (average particle size 0.56 μm)
1.5 parts by weight Calcium carbonate (average particle size 1.8 μm, oil absorption 30 ml / 100 g) 50 parts by weight gum arabic powder 20 parts by weight The above ingredients were pulverized with a small pulverizer and the pulverized product was baked in an alumina pot. It was filled together with the ball and processed with a ball mill to obtain a composite powder.

Preparation of composite pigment 10 (coverage 95%) C.I. I. Pigment red 48: 3 (average particle size 0.03 μm) 2 parts by weight C.I. I. Pigment Orange 16 (average particle size 0.50 μm) 2 parts by weight C.I. I. Pigment Yellow 1 (average particle size 0.38 μm)
0.1 parts by weight Calcium carbonate (average particle diameter 1.8 μm, oil absorption 30 ml / 100 g) 25 parts by weight Gum arabic powder 7 parts by weight The above components were mixed with a Henschel mixer to obtain a composite powder.

Preparation of composite pigment 11 (coverage 6%) C.I. I. Pigment Blue 15: 3 (average particle size 0.02 μm)
15 parts by weight C.I. I. Pigment Violet 23 (average particle size 0.20 μm)
2.5 parts by weight Silica (average particle size 0.3 μm, oil absorption 160 ml / 100 g) 30 parts by weight The above components were pulverized with a small pulverizer, and the pulverized product was filled with alumina sintered balls in an alumina pot. To obtain a composite powder.

Preparation of composite pigment 12 (coverage 12%) C.I. I. Pigment Yellow 3 (average particle size 0.60 μm) 1 part by weight C.I. I. Pigment Yellow 1 (average particle size 0.38 μm) 2 parts by weight Silica (average particle size 1.0 μm oil absorption 120 ml / 100 g) 20 parts by weight The above components were pulverized with a small pulverizer, and the pulverized product was baked in an alumina pot. It was filled together with the ball and processed with a ball mill to obtain a composite powder.

Preparation of composite pigment 13 (coverage 57%) C.I. I. Pigment red 48: 3 (average particle size 0.03 μm) 2 parts by weight C.I. I. Pigment Orange 16 (average particle size 0.50 μm) 2 parts by weight C.I. I. Pigment Yellow 1 (average particle size 0.38 μm)
0.1 parts by weight Silica (average particle size 1.0 μm oil absorption 120 ml / 100 g) 30 parts by weight Gum arabic powder 7 parts by weight The above components were mixed with a Henschel mixer to obtain a composite powder.

Preparation of composite pigment 14 (coverage 88%) C.I. I. Pigment Green 7 (average particle size 0.03 μm) 1.5 parts by weight C.I. I. Pigment Yellow 3 (average particle size 0.56 μm)
1.5 parts by weight Silica (average particle size 1.0 μm, oil absorption 120 ml / 100 g) 10 parts by weight Gum arabic powder 20 parts by weight The above components were mixed with a Henschel mixer to obtain a composite powder.

Preparation of composite pigment 15 (94% of coverage) C.I. I. Pigment Blue 15: 3 (average particle size 0.02 μm)
30 parts by weight C.I. I. Pigment Red 150 (average particle size 0.18 μm) 10 parts by weight Silica (average particle size 1.0 μm, oil absorption 120 ml / 100 g) 10 parts by weight The above components were mixed with a Henschel mixer to obtain a composite powder.

(Example 1) Watercolor paint Composite pigment 1 15 parts by weight Heavy calcium carbonate 22 parts by weight Silica 2 parts by weight Arabic gum 14 parts by weight Dextrin 8 parts by weight Glycerin 9 parts by weight Propylene glycol 1 part by weight Thiabendazole 0.1 part by weight Fluoride Sodium 0.002 part by weight Potassium sorbate 0.5 part by weight Sodium dehydroacetate 0.25 part by weight Suneye buck sodium omazine (containing 2-pyridinethiol-1-oxide / sodium salt 40%, manufactured by Sanai Oil Co., Ltd.) 0.4 part by weight Demol N (sodium salt of β-naphthalene sulfonic acid formalin condensate, manufactured by Kao Corporation) 0.3 part by weight water 28 parts by weight After stirring the above components with a laboratory mixer for 15 minutes, a three roll mill I went through it twice and got an indigo watercolor.

Example 2 Watercolor Paint Composite Pigment 2 55 parts by weight Silica 2 parts by weight Carboxymethylcellulose 1 part by weight Glycerin 5 parts by weight Propylene glycol 1 part by weight Thiabendazole 0.5 part by weight Sodium fluoride 0.001 part by weight Sodium dehydroacetate 0. 3 parts by weight Sodium benzoate 1 part by weight Water 34.2 parts by weight The above ingredients were stirred with a lab mixer for 10 minutes and then passed twice with a three-roll mill to obtain a green watercolor paint.

(Example 3) Watercolor paint Composite pigment 3 41 parts by weight Alumina silica 7 parts by weight Dextrin 15 parts by weight Glycerin 9 parts by weight Propylene glycol 1 part by weight Thiabendazole 0.5 part by weight 2-Bromo-2-nitropropane-1,3- Diol
0.5 parts by weight Sodium dehydroacetate 0.3 parts by weight Potassium sorbate 0.3 parts by weight Water 25.4 parts by weight The above ingredients were stirred for 10 minutes with a laboratory mixer and then passed twice with a three-roll mill. Later, I got a vermilion watercolor paint.

(Example 4) Watercolor paint Composite pigment 4 55 parts by weight Silica 2 parts by weight Carboxymethyl cellulose 1 part by weight Glycerin 5 parts by weight Propylene glycol 1 part by weight Thiabendazole 0.5 part by weight Sodium fluoride 0.001 part by weight Sodium dehydroacetate 0. 3 parts by weight Sodium benzoate 1 part by weight Water 34.2 parts by weight The above ingredients were stirred with a lab mixer for 10 minutes and then passed twice with a three-roll mill to obtain a green watercolor paint.

(Example 5) Watercolor paint Composite pigment 5 41 parts by weight Alumina silica 7 parts by weight Dextrin 15 parts by weight Glycerin 9 parts by weight Propylene glycol 1 part by weight Thiabendazole 0.5 part by weight 2-Bromo-2-nitropropane-1,3- Diol
0.5 parts by weight Sodium dehydroacetate 0.3 parts by weight Potassium sorbate 0.3 parts by weight Water 25.4 parts by weight The above ingredients were stirred for 10 minutes with a laboratory mixer and then passed twice with a three-roll mill. Later, I got a vermilion watercolor paint.

(Example 6) Watercolor paint Composite pigment 6 39 parts by weight Dextrin 4 parts by weight Glycerin 9 parts by weight Propylene glycol 1 part by weight Thiabendazole 1 part by weight Chloroacetamide 0.3 part by weight Sodium benzoate 1 part by weight Potassium sorbate 0.3 part by weight Part Demol N (sodium salt of β-naphthalenesulfonic acid formalin condensate, manufactured by Kao Corporation) 0.5 parts by weight Water 43.9 parts by weight After stirring the above components with a laboratory mixer for 10 minutes, using a three roll mill After two passes, a yellow watercolor was obtained.

(Comparative Example 1)
In Example 1, the composite pigment 1 was prepared by adding 3.5 parts by weight of copper phthalocyanine blue (CI Pigment Name Blue 15: 3), 11 parts by weight of heavy calcium carbonate, and dioxazine violet (CI Pigment Name). A watercolor paint was obtained in the same manner as in Example 1 except that Violet 23) was changed to 0.5 part by weight.

(Comparative Example 2)
A watercolor paint was obtained in the same manner as in Example 1 except that the composite pigment 1 was replaced with the composite pigment 7 in Example 1.

(Comparative Example 3)
A watercolor paint was obtained in the same manner as in Example 1 except that the composite pigment 1 was replaced with the composite pigment 8 in Example 1.

(Comparative Example 4)
A watercolor paint was obtained in the same manner as in Example 2 except that the composite pigment 2 was replaced with the composite pigment 9 in Example 2.

(Comparative Example 5)
A watercolor paint was obtained in the same manner as in Example 3, except that the composite pigment 3 was replaced with the composite pigment 10 in Example 3.

(Comparative Example 6)
A watercolor paint was obtained in the same manner as in Example 1 except that the composite pigment 1 was replaced with the composite pigment 11 in Example 1.

(Comparative Example 7)
A watercolor paint was obtained in the same manner as in Example 6 except that the composite pigment 6 was replaced with the composite pigment 12 in Example 6.

(Comparative Example 8)
A watercolor paint was obtained in the same manner as in Example 3 except that the composite pigment 3 was replaced with the composite pigment 13 in Example 3.

(Comparative Example 9)
A watercolor paint was obtained in the same manner as in Example 2 except that the composite pigment 2 was replaced with the composite pigment 14 in Example 2.

(Comparative Example 10)
A watercolor paint was obtained in the same manner as in Example 1 except that the composite pigment 1 was replaced with the composite pigment 15 in Example 1.

  Table 1 shows the results of confirming the cleanability of the aqueous paint compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 10 to the plastic palette and the color of the paint.

Detergent measurement method Palette (ZZL-31 (Pentel (manufactured)) material: high impact polystyrene) 1 g of watercolor paint is added, 1 g of distilled water is added, and paint brush (ZBNR-14 (manufactured by Pentel Co., Ltd.)) is used. After mixing well, it was dried at room temperature for 30 minutes, and the pallet surface was washed with a paintbrush (ZBNF-14, manufactured by Pentel Co., Ltd.) for 15 seconds under running water, and this operation was repeated 10 times. Then, the Y value was measured for the uncoated part (A) and the coating mark (B) on the pallet surface with a spectral color difference meter NF-777 (manufactured by Nippon Denshoku Industries Co., Ltd.). B / A × 100 The larger the value, the better the cleaning performance.

Colorability measurement method 1 g of 2 g of water is mixed with a watercolor paint with a paintbrush (ZBNF-6 (manufactured by Pentel)), drawing paper (basis weight 73.3 to 210 g / cubic meter, whiteness of 75% or more) ) Was applied to a size of 170 × 250 square centimeters and dried, and the drawing surface was measured for chroma (C value) with a spectral color difference meter NF-777 (manufactured by Nippon Denshoku Industries Co., Ltd.). The higher the saturation value, the brighter the color.

Claims (3)

An aqueous paint composition containing at least water, a water-soluble resin, and a composite pigment obtained by adhering calcium carbonate and an organic pigment. 2. The aqueous paint composition according to claim 1, wherein the composite pigment is a calcium carbonate surface coated with an organic pigment having a coverage of 10% to 90%. 3. The aqueous paint composition according to claim 1, wherein an average particle size of the organic pigment is 1/3 or less of an average particle size of the calcium carbonate.