Paint

Abstract

This paint contains a first coloring material which is colored resin beads having a particle diameter of 1.0 μm or more, a second coloring material which is a particulate coloring pigment having a particle diameter of 0.5 μm or less, and a particulate extender pigment, wherein the second coloring material exhibits a hue different from that of the first coloring material.

Description

paint CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from Japanese Patent Application No. 2024-006249, the contents of which are incorporated herein by reference.

[0002] The present invention relates to a paint that is easy to express color separation.

[0003] Patent Document 1 discloses a paint composition containing a color pigment and an extender pigment, the extender pigment being particles having a uniform shape. This paint composition uses a uniformly shaped light calcium carbonate as the extender pigment. Patent Document 1 explains that, unlike paint compositions using irregularly shaped heavy calcium carbonate as the extender pigment, this paint composition can thicken the coating film applied to drawing paper or the like, thereby increasing the covering power and effectively increasing the hiding power of the color pigment.

[0004] Japanese Patent Application Publication No. 2000-72988

[0005] On the other hand, when developing paints, two or more colorants may be mixed to create a single paint prototype in order to adjust the hue of the paint. However, traditionally, a paint is required to exhibit a single, uniform hue without unevenness. For this reason, uneven, non-uniform paints have been judged to be of poor quality. If this standard of judgment could be changed and paints that are easier to intentionally express color separation could be developed, such paints would be desirable as a new means of easily expressing a variety of colors in paintings, for example.

[0006] Therefore, an object of the present invention is to provide a paint that can easily express intentional color separation.

[0007] In order to solve the above problems, a paint according to one embodiment comprises a first coloring material which is a colored resin bead having a particle diameter of 1.0 μm or more, a second coloring material which is a particulate coloring pigment having a particle diameter of 0.5 μm or less, and a particulate extender pigment, and the second coloring material exhibits a different hue from that of the first coloring material.

[0008] Figure 1 is a photograph showing an example of how, when the paint of Example 2 was applied to watercolor paper together with water, areas where the hue of the first coloring material (fluorescent red) appeared and areas where the hue of the second coloring material (non-fluorescent blue) appeared appeared separately on the watercolor paper.

[0009] A paint according to one embodiment (hereinafter also referred to as "the paint") is a watercolor paint (paint composition for watercolor painting) containing a first coloring material, a second coloring material, and an extender pigment.

[0010] Generally, watercolors are applied to paper along with water. Paper is a material composed of numerous cellulosic fibers (fibers primarily composed of cellulose). When paper comes into contact with water, the water penetrates the gaps between the hydrophilic cellulosic fibers, and the porous cellulosic fibers absorb water through capillary action, causing the paper to bleed. In this process, the smaller the particle size of the pigment particles contained in the paint, the more likely they are to diffuse across a wider area of ​​the paper with the water and spread out like a bleed until the paper dries. On the other hand, larger particles are less likely to diffuse across a wider area of ​​the paper and remain in the area where the paint was applied.

[0011] The first coloring material is resin beads colored with a dye or coloring pigment (hereinafter also referred to as "colored resin beads") and can be generally used for coloring. Examples of colored resin beads colored with a dye include those obtained by dyeing an aqueous dispersion of polymer particles obtained by emulsion polymerization using a resin such as styrene resin, acrylic resin, acrylonitrile resin, or a copolymer resin primarily composed of these resins with any dye. The dye may be a non-fluorescent dye or a dye containing a fluorescent dye. When a dye containing a fluorescent dye is used, the resulting colored resin beads exhibit a fluorescent color. The dye is fixed to the colored resin beads and is substantially insoluble in water. Alternatively, examples of colored resin beads colored with a coloring pigment include those obtained by mixing a resin such as an acrylic resin, a urethane resin, or a polyester resin with a coloring pigment and solidifying the mixture using a resin beading method, in which the coloring pigment is encapsulated in the solidified resin beads. Examples of coloring pigments encapsulated in the resin beads include the coloring pigments exemplified in the description of the second coloring material described below. Various colored resin bead products are also commercially available. The first colorant may be commercially available colored resin beads.

[0012] From the viewpoint of preventing the colored resin beads from diffusing over a wide area of ​​the paper along with the water, the particle diameter of the colored resin beads in the first coloring material is 1.0 μm or more. From the same viewpoint, the particle diameter of the colored resin beads in the first coloring material may be, for example, 2.0 μm or more or 3.0 μm or more, preferably 4.0 μm or more, and more preferably 5.0 μm or more. On the other hand, the larger the particle diameter, the more difficult it is for the colorant to adhere to the paper after application and the more likely it is to fall off the paper. From the viewpoint of preventing this, the particle diameter of the colored resin beads in the first coloring material may be, for example, 20 μm or less or 15 μm or less, preferably 10 μm or less, and more preferably 8.0 μm or less. Therefore, the particle diameter of the colored resin beads in the first coloring material may be, for example, 1.0 μm or more to 20 μm or 2.0 μm or more to 20 μm or less, preferably 4.0 μm or more to 10 μm or less, and more preferably 5.0 μm or more to 8.0 μm or less.

[0013] The "particle size" in this specification refers to the particle size (median diameter D) at which the cumulative value in the volume-based cumulative particle size distribution reaches 50% as determined by a method in accordance with JIS Z 8825:2013 (particle size analysis - laser diffraction and scattering method). ５０ (median diameter)). Using colored resin beads or pigments as samples, particle size can be measured using a laser diffraction / scattering particle size distribution analyzer or the like. To measure the particle size of a single type of colored resin bead or pigment in a composition containing one or more types of colored resin beads or multiple types of pigments, such as the present paint, the composition can be centrifuged, and the colored resin bead particles or pigment particles can be fractionated from the composition according to their specific gravity. The particles contained in each fraction obtained by centrifugation can then be collected and used as the sample for the above-mentioned method. When two or more types of particles are observed when observing each particle contained in a fraction obtained by centrifugation with the naked eye or an optical microscope (for example, when red colored resin bead particles and blue colored pigment particles are observed in a fraction), the particles can be further centrifuged and fractionated to further separate the two or more types of particles according to their specific gravity, and the colored resin beads or pigments collected from the fraction after fractionation can be used as the sample for measurement.

[0014] The specific gravity of the first colorant at 25°C may be, for example, 2.5 or less, or 2.0 or less. On the other hand, particles with lower specific gravity tend to float more easily in the coating film formed when the present paint is applied to paper together with water, and take longer to settle in the coating film. Therefore, it is believed that particles with lower specific gravity settle after the extender pigment particles described below. As a result, particles with lower specific gravity settle on top of the extender pigment particles that have settled and accumulated earlier. Therefore, because they are blocked by the extender pigment particles, they are less likely to penetrate into the gaps between paper fibers, and their diffusion over a wide area of ​​the paper is thought to be suppressed. Thus, from the perspective of making the first colorant more easily fill the paper surface, the specific gravity of the first colorant at 25°C is preferably 1.5 or less, more preferably 1.3 or less. The specific gravity of the first colorant at 25°C may be, for example, greater than 1.0.

[0015] "Specific gravity" in this specification refers to the measured true specific gravity of colored resin beads or pigments at 25°C, according to the method described in JIS K 0061:2001 (Methods for measuring density and specific gravity of chemical products). The true specific gravity of colored resin beads or pigments at 25°C can be measured by the pycnometer method using a commercially available Guy-Lussac-type pycnometer with a thermometer. In order to measure the specific gravity of a certain colored resin bead or a certain pigment in a composition containing colored resin beads and multiple pigments, such as the present paint, the composition can be fractionated by centrifugation as described above in the method for measuring particle size, and the specific gravity can be measured using colored resin beads or pigments collected from the obtained fractions as a sample.

[0016] To clearly show color separation on paper coated with the present paint, the first coloring material may be colored resin beads containing an inorganic fluorescent pigment. Examples of inorganic fluorescent pigments include metal oxides doped with rare earth elements. Alternatively, from the perspective of being easily filled due to their low specific gravity and making color separation more clearly visible, the first coloring material is more preferably colored resin beads containing an organic fluorescent dye. Fluorescent dyes are dyes that primarily exhibit their color through photoluminescence, which emits light upon returning to a ground state after being excited by light absorption. Examples of organic fluorescent dyes include merocyanine, perylene, acridine, luciferin, pyranine, stilbene, rhodamine, coumarin, fluorescein, and umbelliferone, but are not limited to the examples shown here.

[0017] The first colorant may consist of only one type of colored resin beads having a particle diameter of 1.0 μm or more, or may be a combination of two or more types of colored resin beads, each having a particle diameter of 1.0 μm or more. To ensure that the hue of the first colorant appears conspicuous on the paper surface, the content of the first colorant in the paint may be, for example, 5% by weight or more or 10% by weight or more, preferably 15% by weight or more or 20% by weight or more, and more preferably 25% by weight or more. Furthermore, to avoid a situation in which the hue of the first colorant is too conspicuous on the paper surface, thereby obscuring the hue of the second colorant, the content of the first colorant in the paint may be, for example, 40% by weight or less or 35% by weight or less, preferably 32% by weight or less, and more preferably 30% by weight or less. Therefore, the content of the first coloring material in the present paint may be, for example, 5% by mass or more and 40% by mass or less, preferably 15% by mass or more and 32% by mass or less, and more preferably 25% by mass or more and 30% by mass or less.

[0018] The term "content" used herein refers to the content calculated on a solids basis (i.e., the content by dry mass excluding water), unless otherwise specified regarding water (e.g., Tables 1 and 3, etc.). In other words, unless otherwise specified regarding water, the numerical value of the content of each component in the present paint can also be considered the numerical value of the content of each component in the present paint when gently dried at room temperature in a dry atmosphere until the paint is uniformly dried throughout and maintains a constant weight. "Room temperature" in this specification refers to a constant temperature between 5°C and 35°C. Furthermore, in the case where the present paint contains two or more components for which content is indicated, the term "content" in this specification refers to the "total content" of those two or more components. For example, in the case where the present paint contains two or more types of colored resin beads corresponding to the first colorant, the term "content of the first colorant" refers to the total content of those two or more types of colored resin beads.

[0019] The second colorant is a water- or oil-insoluble particulate color pigment or a mixture of two or more color pigments commonly used for coloring. To facilitate diffusion of the second colorant over a wider area of ​​paper than the first colorant, the particle diameter of the second colorant is 0.50 μm or less, for example, 0.40 μm or less, preferably 0.30 μm or less, and more preferably 0.25 μm or less. The particle diameter of the second colorant may be, for example, 0.05 μm or more, preferably 0.10 μm or more, and more preferably 0.15 μm or more. Therefore, the particle diameter of the second colorant may be, for example, 0.05 μm or more to 0.50 μm or less, or 0.05 μm or more to 0.40 μm or less, preferably 0.10 μm or more to 0.30 μm or less, and more preferably 0.15 μm or more to 0.25 μm or less.

[0020] From the viewpoint of highlighting the appearance on the paper of the areas where the dark hue of the first coloring material is exhibited and the areas where the dark hue of the second coloring material is exhibited separately, the ratio of the particle diameter of the colored resin beads in the first coloring material to the particle diameter of the colored pigment in the second coloring material (particle diameter (μm) of the colored resin beads in the first coloring material / particle diameter (μm) of the colored pigment in the second coloring material) may be, for example, 5.0 or more, preferably 10 or more, more preferably 20 or more, and even more preferably 30 or more.

[0021] The specific gravity of the second colorant at 25°C may be, for example, 2.6 or less, 2.4 or less, or 2.3 or less, or 1.6 or more, 1.8 or more, or 2.0 or more. From the viewpoint of facilitating the diffusion of the color pigment in the second colorant across a wider range of paper, the specific gravity of the second colorant at 25°C is preferably greater than the specific gravity of the first colorant at 25°C. When the specific gravity of the second colorant is greater, in a coating film formed by applying the present paint to paper, the color pigment particles in the second colorant settle to the paper surface before the colored resin bead particles in the first colorant, and penetrate into the gaps between the fibers constituting the paper together with water, thereby facilitating the diffusion of the color pigment particles in the second colorant across a wider range of paper. From the same viewpoint, the specific gravity of the second colorant at 25°C is more preferably 1.3 times or more, and even more preferably 1.6 times or more, of the specific gravity of the first colorant at 25°C.

[0022] The second colorant may be a non-fluorescent, colored, particulate inorganic pigment. Non-fluorescent, colored particulate inorganic pigments are preferred from the viewpoints of high hiding power, excellent lightfastness and heat resistance, and a relatively large specific gravity compared to non-fluorescent, colored, particulate organic pigments described below. Examples of white inorganic pigment materials include titanium oxide, white lead (basic lead carbonate), zinc oxide (zinc oxide), and lithopone (barium sulfate / zinc sulfide). Examples of red inorganic pigment materials include red iron oxide (iron (III) oxide), red lead (lead oxide), vermilion (mercury sulfide), and molybdenum red. Examples of yellow inorganic pigment materials include lead yellow (lead chromate), cadmium yellow (cadmium sulfide), zinc chromate (zinc chromate), and litharge (lead monoxide). Examples of blue inorganic pigment materials include ultramarine, Prussian blue (iron (III) ferrocyanide), and cobalt aluminate. Examples of black inorganic pigment materials include iron black (iron (II, III) oxide) and carbon black.

[0023] The second colorant may be a non-fluorescent, colored, particulate organic pigment. Non-fluorescent, colored, particulate organic pigments are preferred in that they tend to be more colorful than the non-fluorescent, colored, particulate inorganic pigments described above. Examples of colored organic pigments include polycyclic pigments, azo pigments, and lake pigments. Examples of yellow polycyclic pigments include isoindolinone, isoindoline, azomethine, anthraquinone, anthrone, and xanthene. Examples of orange polycyclic pigments include diketopyrrolopyrrole, anthrone, perinone, and quinacridone. Examples of red polycyclic pigments include quinacridone, diketopyrrolopyrrole, anthraquinone, perinone, and indigoid. Examples of purple polycyclic pigments include dioxazine, quinacridone, anthrone, and xanthene. Examples of blue polycyclic pigment materials include phthalocyanine, anthraquinone, indigoid, etc. Examples of green polycyclic pigment materials include azomethine, etc.

[0024] The second colorant may be, for example, one colorant selected from a non-fluorescent and colored particulate inorganic pigment, a non-fluorescent and colored particulate organic pigment, and a fluorescent and colored particulate organic pigment, or a combination of two or more colorant pigments. From the viewpoint of visually making it easier to see that the hues exhibited by the first colorant and the second colorant appear separately, it is preferable that the first colorant be colored resin beads containing a fluorescent dye, and the second colorant be a non-fluorescent and particulate colorant. In this specification, "non-fluorescent" means that no coloring due to photoluminescence is observed, i.e., the colorant exhibits its hue through the absorption and reflection of light. In other words, a "non-fluorescent and particulate colorant" can also be said to be a particulate colorant that does not contain a fluorescent dye.

[0025] From the viewpoint of visually making it easy to see that the hue of the first coloring material and the hue of the second coloring material appear separately on paper coated with this paint, the second coloring material is a color pigment that exhibits a hue different from that of the first coloring material. When designing this paint, it is preferable to select a color pigment that exhibits a hue different from that of the first coloring material as the second coloring material. Here, "different hues" means that a normal person who is not recognized as having color vision deficiencies can visually examine an area formed by applying this paint to paper, where the hue of the first coloring material is dark, and an area where the hue of the second coloring material is dark, and recognize that the hues exhibited by the two areas are different.

[0026] From the viewpoint of making it easier to visually understand that the hue exhibited by the first coloring material and the hue exhibited by the second coloring material appear separately, the hue exhibited by the first coloring material and the hue exhibited by the second coloring material are preferably separated by an angle of 90° or more and 270° or less, more preferably 120° or more and 240° or less, and even more preferably 150° or more and 210° or less on the hue wheel of the Munsell hue system. The hue wheel of the Munsell color system may be any one that conforms to JIS Z 8721-1993 (Method of displaying color - display by three attributes), and may be divided into, for example, 10 hues, 24 hues, or 100 hues.

[0027] As a combination of the hue exhibited by the first coloring material and the hue exhibited by the second coloring material, from the viewpoint of highlighting the separation of colors by expressing contrasting color combinations of warm and cool colors, preferred combinations include, for example, red (R) and blue-green (BG), yellow-red (YR) and blue (B), yellow (Y) and purple-blue (PB), yellow-green (GY) and purple (P), green (G) and red-purple (RP), blue-green (BG) and red (R), blue (B) and yellow-red (YR), purple-blue (PB) and yellow (Y), purple (P) and yellow-green (GY), and red-purple (RP) and green (G). Furthermore, from the viewpoint of further enhancing the color separation by a combination in which the first coloring material exhibits a fluorescent warm hue and the second coloring material exhibits a non-fluorescent cool hue, a combination in which the first coloring material is colored resin beads containing an organic fluorescent dye selected from red (R), yellow-red (YR), and yellow (Y), and the second coloring material is a non-fluorescent coloring pigment selected from blue-green (BG), blue (B), and purple-blue (PB) is even more preferable. Specific hue combinations are not limited to the examples given here.

[0028] The content of the second colorant in the present paint may be, for example, 1.0% by mass or more, preferably 2.0% by mass or more, and more preferably 3.0% by mass or more, from the viewpoint of making the hue of the second colorant conspicuous on the paper surface. Furthermore, from the viewpoint of avoiding a situation in which the hue of the second colorant is too conspicuous and the hue of the first colorant becomes relatively less conspicuous, the content of the second colorant in the present paint may be, for example, 30% by mass or less or 20% by mass or less, preferably 15% by mass or less or 10% by mass or less, and more preferably 5.0% by mass or less. Therefore, the content of the second colorant in the present paint may be, for example, 1.0% by mass or more but 30% by mass or less, preferably 2.0% by mass or more but 15% by mass or less, and more preferably 3.0% by mass or more but 5.0% by mass or less.

[0029] From the viewpoint of making the hue of the first coloring material appear conspicuously on the paper surface, the ratio of the content of the first coloring material to the content of the second coloring material in the present paint (content of first coloring material / content of second coloring material) may be, for example, 1.0 or more, 2.0 or more, or 3.0 or more, preferably 4.0 or more or 5.0 or more, and more preferably 6.0 or more or 7.0 or more. From the viewpoint of making the hue of the second coloring material appear conspicuously on the paper surface, the ratio of the content of the first coloring material to the content of the second coloring material in the present paint (content of first coloring material / content of second coloring material) may be, for example, 10.0 or less or 9.0 or less, and preferably 8.0 or less. From the viewpoint of highlighting both the hue exhibited by the first coloring material and the hue exhibited by the second coloring material, the ratio of the content of the first coloring material to the content of the second coloring material in the present paint (content of first coloring material / content of second coloring material) is preferably 4.0 or more and 10.0 or less, and more preferably 6.0 or more and 8.0 or less.

[0030] Extender pigments are pigments with high transparency, low hiding power, and properties that make them difficult to use as coloring pigments. Generally, extender pigments are blended into paints for purposes such as extending, diluting, or strengthening the paint film. The colored resin beads and coloring pigments mentioned above do not qualify as extender pigments in this paint. Examples of extender pigment materials include barite (barium sulfate), precipitated barium sulfate, gypsum (hydrated calcium sulfate), white china clay (kaolin), silica (silicon dioxide), white carbon (precipitated silica), talc, barium carbonate, and calcium carbonate.

[0031] From the viewpoint of easily fixing the colored resin bead particles in the first coloring material on the paper surface, the particle diameter of the extender pigment in the present paint may be, for example, 3.0 μm or more, preferably 4.0 μm or more, and more preferably 5.0 μm or more. From the viewpoint of preventing the extender pigment from falling off the paper surface, the particle diameter of the extender pigment may be, for example, 20 μm or less or 15 μm or less, preferably 10 μm or less or 8.0 μm or less, and more preferably 6.0 μm or less. Therefore, the particle diameter of the extender pigment may be, for example, 3.0 μm or more and 20 μm or less, preferably 4.0 μm or more and 10 μm or less, and more preferably 5.0 μm or more and 6.0 μm or less.

[0032] The specific gravity of the extender pigment in the present paint at 25°C is not particularly limited as long as it does not contradict the object of the present invention, and may be, for example, 4.0 or less, 3.5 or less, 3.0 or less, or 2.8 or less, or 1.8 or more, 2.0 or more, 2.2 or more, or 2.4 or more. From the viewpoint of easily fixing the first coloring material on the paper surface, it is preferable that the extender pigment in the present paint has a specific gravity at 25°C greater than that of the first coloring material. From the same viewpoint, it is more preferable that the specific gravity of the extender pigment at 25°C be 1.5 times or more, and even more preferably 2.0 times or more, the specific gravity of the first coloring material at 25°C.

[0033] From the perspective of clearly showing color separation on paper coated with the present paint, the extender pigment in the present paint is preferably a pigment made from crushed minerals or shells. Examples of crushed mineral extender pigments include kaolin. Examples of crushed shell extender pigments include chalk. Particles of such pigments (e.g., chalk) are relatively large in particle size, irregular in shape, and vary in shape from particle to particle compared to particles of chemically synthesized extender pigments (e.g., precipitated calcium carbonate). The mechanism by which color separation is likely to occur when using extender pigments with irregular particle shapes is unclear, but is thought to be as follows: In a coating film applied to paper with the present paint, the layer where irregularly shaped extender pigment particles settle and accumulate on the paper surface is likely to form gaps of a size that make it difficult for the colored resin beads of the first coloring material, which have a relatively large particle size, to pass through, but gaps of a size that make it easy for the colored pigment particles of the second coloring material, which have a relatively small particle size, to pass through. For this reason, the first coloring material is blocked on the paper surface by the layer of extender pigment and does not diffuse over a wide area of ​​the paper, whereas the second coloring material passes through the gaps formed in the layer of extender pigment and migrates into the gaps between the fibers that make up the paper, and is thought to be more likely to diffuse, bleeding over a wide area of ​​the paper together with the water, through the gaps between these fibers.

[0034] From a similar perspective, it is more preferable that the extender pigment in the present paint is chalk. The particle diameter of chalk may be, for example, 3.0 μm to 20 μm or 4.0 μm to 15 μm, and preferably 5.0 μm to 10 μm. From the perspective of easily producing color separation, it is more preferable that the chalk contains scaly particles when observed under a microscope. In other words, it can be said that it is more preferable that the extender pigment in the present paint contains scaly calcium carbonate particles. From a similar perspective, the aspect ratio of the approximately rectangular surface formed on the chalk particle (length of the long side of the surface (μm) / length of the short side of the surface perpendicular to the long side (μm)) may be greater than 1.5, for example, and is preferably 2.0 or greater, and more preferably 3.0 or greater. Due to the mechanism described above, gofun containing such scale-like particles is suitable for blocking the colored resin bead particles of the first coloring material on the paper surface with a layer of gofun, while for the colored pigment particles of the second coloring material, it is thought that the shape of the gofun makes it easy for the colored pigment particles to pass through the gaps formed in the gofun layer, making it easy for the colored pigment particles of the second coloring material to diffuse over a wide area of ​​the paper together with the water.

[0035] The present paint may contain only one type of extender pigment, or two or more types. From the viewpoint of efficiently fixing the first coloring material on the paper surface and thereby enhancing color separation, the content of the extender pigment in the present paint may be, for example, 5.0% by mass or more, preferably 10% by mass or more, and more preferably 15% by mass or more. Furthermore, from the viewpoint of preventing the extender pigment from falling off the paper surface, the content of the extender pigment in the present paint may be, for example, 30% by mass or less, preferably 25% by mass or less, and more preferably 20% by mass or less. Therefore, the content of the extender pigment in the present paint may be, for example, 5.0% by mass or more to 30% by mass or less, preferably 10% by mass or more to 25% by mass or less, and more preferably 15% by mass or more to 20% by mass or less.

[0036] In addition to the first coloring material, second coloring material, and extender pigment, the present paint may further contain, as necessary, one or more selected from a water-soluble polymeric compound, an amphipathic polymeric compound, a wetting agent, an antiseptic / fungal agent, a drying accelerator, a surfactant, a dispersant, an antifoaming agent, and water.

[0037] The water-soluble polymer compounds and amphiphilic polymer compounds impart pigment dispersibility and paper fixation to the present paint. Examples of water-soluble polymer compounds include gum arabic, dextrin, and carboxymethyl cellulose. Examples of amphiphilic polymer compounds include vinyl acetate-acrylic copolymers. These polymer compounds may be used alone or in combination. The content of one or more polymer compounds selected from water-soluble polymer compounds and amphiphilic polymer compounds in the present paint may be, for example, 5% by mass or 10% by mass or more, and preferably 20% by mass or more, from the perspective of further imparting pigment dispersibility and paper fixation. Furthermore, as described below, in the present paint in a solid form, the content of one or more polymer compounds selected from water-soluble polymer compounds and amphiphilic polymer compounds is more preferably 35% by mass or more, and even more preferably 40% by mass or more. Furthermore, from the viewpoint of avoiding a situation in which the present paint becomes excessively viscous, the content of one or more polymeric compounds selected from water-soluble polymeric compounds and amphiphilic polymeric compounds in the present paint may be, for example, 60% by mass or less, preferably 55% by mass or less, and even more preferably 50% by mass or less. Therefore, the content of one or more polymeric compounds selected from water-soluble polymeric compounds and amphiphilic polymeric compounds in the present paint may be, for example, 5% by mass or more and 60% by mass or less, preferably 20% by mass or more and 55% by mass or less, more preferably 35% by mass or more and 50% by mass or less, and even more preferably 40% by mass or more and 50% by mass or less.

[0038] The humectant serves to maintain the appropriate moisture content of the paint and enhance its dispersibility in water during use. Examples of humectants include compounds such as glycerin, ethylene glycol, propylene glycol, and polyethylene glycol. These compounds may be used alone or in combination. The content of the humectant in the paint may be, for example, 3.0% by mass or more, preferably 4.0% by mass or more, from the viewpoint of maintaining the moisture content and enhancing resolubility. Furthermore, to avoid excessively slow drying of the paint, the content of the humectant in the paint may be, for example, 40% by mass or less or 30% by mass or less, preferably 20% by mass or less, and more preferably 10% by mass or less. Therefore, the content of the humectant in the paint may be, for example, 3.0% by mass or more and 40% by mass or less, preferably 4.0% by mass or more and 20% by mass or less, and more preferably 4.0% by mass or more and 10% by mass or less.

[0039] The antiseptic and antifungal agent may be one that has been conventionally used in paints. Examples of antiseptic and antifungal agents include compounds such as phenol, xylenol, formaldehyde, potassium sorbate, sodium dehydroacetate, methyl benzoate, dithio-2,2'-bis(benzmethylamide), 2-methylisothiazolin-3-one, 2-(4-thiazolyl)benzimidazole, and 2-thiocyanomethylthiobenzothiazole. These compounds may be used alone or in combination of two or more. The content of the antiseptic and antifungal agent in the paint may be, for example, 0.01% by mass or more, or 0.05% by mass or more, and may be, for example, 5.0% by mass or less, or 1.0% by mass or less.

[0040] Drying accelerators, surfactants, dispersants, and defoamers conventionally used in paints may be included in the present paint in amounts conventionally included in paints. When the present paint is manufactured in tube form, some water may be included in the present paint. However, when the present paint is in a low-viscosity tube form containing a large amount of water, the pigments may settle and separate based on their specific gravity before being mixed with water for use. To solve this problem, the present paint is preferably in the form of a solid paint. The water content of the solid paint is not particularly limited as long as it does not conflict with the objectives of the present invention, but it may be, for example, 10% by weight or less, or 5% to 9% by weight or less. Solid paints are watercolor paints in a solid state, and are also called solid watercolor paints or pigments. Taking advantage of the water-soluble nature of solid paints, users can express color shading, bleeding, shading, etc. on paper by adding water to the solid paint.

[0041] When producing the present paint in the form of a solid paint, it is preferable to gently dry the present paint in a highly viscous liquid form at room temperature to remove most of the water. From the viewpoint of avoiding the situation where the various pigments contained in the present paint in liquid form settle and separate based on their specific gravities during drying at room temperature until the present paint in liquid form solidifies, it is preferable to produce the present paint in the form of a solid paint by drying the present paint in liquid form when the content of one or more selected from the aforementioned water-soluble polymer compounds and amphiphilic polymer compounds is 35% by mass or more at room temperature. Furthermore, from the viewpoint of avoiding the occurrence of unnatural depressions on the surface of the resulting present paint in the form of a solid paint, it is preferable to produce the present paint in solid form by drying the present paint in liquid form when the content of one or more selected from the aforementioned water-soluble polymer compounds and amphiphilic polymer compounds is 40% by mass or more at room temperature.

[0042] The present paint may further contain other colorants, which are color pigments with particle sizes greater than 0.5 μm, as long as such addition does not detract from the objectives of the present invention. The upper limit of the particle size of the other colorants may be the same as the upper limit of the particle size described above in the description of the first colorant. However, from the perspective of making the separation between the hues exhibited by the first colorant and the second colorant more clearly apparent on the paper, the content of the other colorants in the present paint may be, for example, 10% by mass or less, 5% by mass or less, 2% by mass or less, or 1% by mass or less. From the same perspective, the present paint is preferably a composition that contains substantially no colorants other than the first colorant and the second colorant.

[0043] The object to which the present paint is applied is not particularly limited as long as it can be painted on the surface using a brush and watercolor paint, but is preferably paper. Examples of paper include drawing paper, watercolor paper, Japanese paper, Kent paper, and construction paper (high-quality paper). Japanese paper is made by filtering a slurry-like raw material whose main component is fiber obtained by beating raw material plants such as paper mulberry, mitsumata, gampi, hemp, coniferous trees, broad-leaved trees, and bamboo. The basis weight of the paper is not particularly limited as long as it is possible for the second coloring material to spread on the paper surface together with water when the present paint is applied to the paper, and is, for example, 5 g / m ２ More than 200g / m ２ It may be less than 30 g / m ２ 130g / m or more ２ In order to enhance the separation of colors, it is preferable that the paper has no sizing (to prevent water bleeding) on ​​the surface.

[0044] The subject matter disclosed in this specification includes the following: (1) A paint comprising a first coloring material that is a colored resin bead having a particle diameter of 1.0 μm or more, a second coloring material that is a particulate color pigment having a particle diameter of 0.5 μm or less, and a particulate extender pigment, wherein the second coloring material exhibits a hue different from that of the first coloring material. (2) The paint described in (1) above, wherein the extender pigment has a specific gravity at 25°C greater than that of the first coloring material. (3) The paint described in (1) or (2) above, wherein the extender pigment includes chalk. (4) The paint described in any of (1) to (3) above, wherein the first coloring material is a colored resin bead containing a fluorescent dye, and the second coloring material is a non-fluorescent coloring pigment. (5) A paint according to any one of (1) to (4) above, wherein the hue exhibited by the first coloring material and the hue exhibited by the second coloring material are separated by an angle of 90° or more and 270° or less on the Munsell hue circle. (6) A paint according to any one of (1) to (5) above, which is a solid paint.

[0045] According to the paint described in (1) above, when the paint is applied to paper while it is wet, the particles of the color pigment (second coloring material) have a relatively small particle size, so they easily penetrate and diffuse into the gaps between the fibers that make up the paper along with the water. On the other hand, the particles of the colored resin beads (first coloring material) have a relatively large particle size, so they are easily blocked by the extender pigment particles and are less likely to penetrate into the gaps between the fibers that make up the paper and to diffuse. In other words, on paper coated with the paint, the particles of the color pigment (second coloring material) are more likely to diffuse over a wider area of ​​the paper than the colored resin beads (first coloring material). Therefore, on paper coated with the paint, areas with a relatively dark hue due to the first coloring material and areas with a relatively dark hue due to the second coloring material tend to appear separately. This makes it possible to provide a paint that easily achieves intentional color separation.

[0046] The present invention is not limited to the above-described embodiments, and various improvements, modifications, or variations can be made based on the knowledge of those skilled in the art without departing from the spirit of the present invention. The present invention may be embodied in a form in which any specific feature is replaced with another technology within the scope of producing the same action or effect.

[0047] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0048] The following commercially available products were prepared as the first coloring material, which is colored resin beads having a particle diameter of 1.0 μm or more: SX-103 (manufactured by Shin-Roihi Co., Ltd., colored resin beads containing a red organic fluorescent dye) SX-104 (manufactured by Shin-Roihi Co., Ltd., colored resin beads containing an orange organic fluorescent dye) SX-105 (manufactured by Shin-Roihi Co., Ltd., colored resin beads containing a yellow organic fluorescent dye) SX-117 (manufactured by Shin-Roihi Co., Ltd., colored resin beads containing a pink organic fluorescent dye) Note that the product series of colored resin beads containing these organic fluorescent dyes are described as having an average particle diameter of 4 μm to 6 μm. Furthermore, when the inventors of the present application measured the particle diameters of the colored resin beads containing these organic fluorescent dyes using the above-mentioned method, for example, a 10% diameter D on a volume basis was found to be 1.0 μm. １０ is 3.65 μm, and the median diameter D ５０ (Median diameter) is 6.67 μm, 90% diameter D ９０ The specific gravity of each of SX-103, SX-104, SX-105 and SX-117 at 25° C. measured by the method described above was 1.2.

[0049] The following commercially available products were prepared as second colorants, which are particulate color pigments having a particle diameter of 0.50 μm or less: SA Blue DY-12K (manufactured by Mikuni Shikiso Co., Ltd., a blue non-fluorescent organic pigment) SA Green DY-4K (manufactured by Mikuni Shikiso Co., Ltd., a green non-fluorescent organic pigment) High Micron Red #7356NB (manufactured by Mikuni Shikiso Co., Ltd., a red non-fluorescent organic pigment) Blue FLGB Conc (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., a blue non-fluorescent organic pigment) Green FLB Conc (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., a green non-fluorescent organic pigment) Golden Yellow FL4G Conc (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., a yellow non-fluorescent organic pigment) SA Blue DY-12K had a particle diameter of 0.17 μm as measured by the method described above, and a specific gravity at 25° C. of 1.62 as measured by the method described above. SA Green DY-4K was similarly measured and found to have a particle size of 0.14 μm and a specific gravity at 25° C. of 2.1.

[0050] The following commercially available products were prepared as other colorants. Note that "Bayferrox" is a registered trademark. Rose #13FD: a rose-colored, non-fluorescent organic pigment manufactured by Noma Chemical Industry Co., Ltd. Bayferrox 3920 (an ochre-colored, non-fluorescent inorganic pigment manufactured by Lanxess K.K.) Bayferrox 110M (a brown, non-fluorescent inorganic pigment manufactured by Lanxess K.K.) Ultramarine Blue 82 (a blue, non-fluorescent inorganic pigment manufactured by Benatar) Note that none of the other colorants prepared here were colored resin beads, and the particle diameters measured by the above-mentioned method were at least 0.5 μm and generally 2.0 μm or greater.

[0051] The following commercially available products were prepared as particulate extender pigments. Generally, the particle diameter of chalk is about 2 μm to 6 μm. Tokuhana Inchoku Gofun (Nakagawa Chalk Manufacturing Co., Ltd., powder made from crushed naturally occurring scallop shells) Barium Sulfate P-30 (Takehara Chemical Industry Co., Ltd., barium sulfate powder) When observed with an optical microscope, Tokuhana Inchoku Gofun contained a large amount of scaly calcium carbonate particles. Furthermore, when the particle diameter of Tokuhana Inchoku Gofun was measured by the method described above, the 10% diameter D on a volume basis was 10 μm. １０ is 1.55 μm, and the median diameter D ５０(Median diameter) is 5.42 μm, 90% diameter D ９０ The specific gravity of the Tokuhana Ingo powder at 25°C was measured by the above-mentioned method and was found to be 2.71.

[0052] The following commercially available water-soluble polymer compounds were prepared: "Amycol" is a registered trademark; Arabic Coal SS (gum arabic, manufactured by San-ei Pharmaceutical Trading Co., Ltd.); Akadama Dextrin (dextrin, manufactured by Nihon Starch Chemical Co., Ltd.); and glycerin, manufactured by Kao Corporation, was prepared as a wetting agent. Preservatives and antifoaming agents that are generally commercially available for blending into paints were also prepared. Tap water from Nara City, Nara Prefecture was used as is.

[0053] Examples 1 to 8 First, a medium composition containing chalk as an extender pigment was prepared according to the formulation shown in Table 1 below.

[0054] Next, a medium composition containing chalk (Table 1), a first coloring material containing a fluorescent dye, and a non-fluorescent second coloring material were mixed according to the formulation shown in Table 2 below. The resulting mixture was filled into a plastic container and gently dried at room temperature, producing the solid watercolor paints (dry pigments) of Examples 1 to 8. The water content of these solid watercolor paints was measured and found to be approximately 8% by mass.

[0055] Examples 9 to 16 First, medium compositions containing barium sulfate as an extender pigment were prepared according to the formulations shown in Table 3 below.

[0056] Next, a medium composition containing barium sulfate (Table 3), a first coloring material containing a fluorescent dye, and a non-fluorescent second coloring material were mixed according to the formulation shown in Table 4 below. The resulting mixture was filled into a plastic container and gently dried at room temperature, producing solid watercolor paints (dry pigments) according to Examples 9 to 16. The water content of these solid watercolor paints was measured and found to be approximately 8% by mass.

[0057] [Comparative Examples 17 to 23] A medium composition containing barium sulfate (Table 3), another non-fluorescent colorant, and a second non-fluorescent colorant were mixed according to the formulation shown in Table 5 below. The resulting mixture was filled into a plastic container, and the container and the resulting mixture were gently dried at room temperature to produce solid watercolor paints (dry pigments) according to each of Comparative Examples 17 to 23. The water content of these solid watercolor paints was measured, and it was found to be approximately 8% by mass.

[0058] [Evaluation Test] For each of the solid watercolor paints prepared as described above, a small amount of paint was gradually dissolved in water using a water-soaked brush tip in a container. The paint was then mixed with a small amount of water on a plastic palette and spread. A sufficient amount was then applied to commercially available watercolor paper using the brush tip. The area of ​​the watercolor paper where the brush tip had been used to write appeared to be the hue of the first colorant or the hue of another colorant. Furthermore, in areas of the watercolor paper slightly away from the areas where these hues appeared, the hue of the second colorant appeared along with the water that had spread. The watercolor paper was visually observed in a bright room, and three criteria were evaluated: beauty of color combination, clarity of color separation, and ease of color separation, each on a four-point scale according to the following criteria. The evaluation results are shown in Tables 6 to 8.

[0059] Beauty of color combination: Evaluation criteria AA The difference between the two colors is clearly visible, making it look particularly beautiful. A The difference between the two colors is clearly visible, making it look beautiful. B Although the color combinations are similar, the difference between the two colors is immediately obvious at a glance. C The colors are so similar that you cannot tell the difference unless you look closely, making it look messy.

[0060] Ease of separation of colors: Evaluation criteria AA When there are two colors that match the colors of the pigments mixed into the paint, it leaves a strong impression. A At a glance, you can tell there are two colors. B If you look closely, you can tell there are two colors. C Even if you look closely, you cannot tell there are two colors.

[0061] Ease of color separation: Evaluation criteria AA The areas where the two colors are each colored are clearly separated on the watercolor paper. A The areas where the two colors are each colored are adjacent, but the boundary is easy to see. B The areas where the two colors are each colored are adjacent, and the boundary is difficult to see. C The two colors are each colored in almost the same area on the watercolor paper, and the boundary is not clear.

[0062]

[0063]

[0064]

[0065] With the paints of Examples 1 to 8, the fluorescent hue of the first coloring material and the non-fluorescent hue of the second coloring material appeared clearly separated on the watercolor paper, resulting in a contrasting drawing with an aurora-like appearance. Figure 1 shows a drawing that appeared on watercolor paper using the paint of Example 2. On the watercolor paper, around the area where the hue of the first coloring material appeared (fluorescent red in Figure 1), areas appeared where the hue of the second coloring material appeared (non-fluorescent blue in Figure 1), as if bleeding out from the area.

[0066] Furthermore, in Examples 1 to 8, which used chalk powder as the extender pigment, the fluorescent hue of the first coloring material and the non-fluorescent hue of the second coloring material were clearly separated in appearance, compared with Examples 9 to 16, which used barium sulfate as the extender pigment. Furthermore, in Examples 1 to 16, which used colored resin beads containing fluorescent dyes as the first coloring material, the beauty of the color combinations was outstanding, showing a particularly beautiful appearance, and were highly rated.

[0067] A solid watercolor paint (dry pigment) according to Comparative Example 24 was also prepared using the same formulation and trial conditions as in Examples 1 to 8 described above, except that commercially available colored resin beads with a particle diameter of approximately 0.4 μm were used instead of the first coloring material used in Examples 1 to 8. However, when the paint according to Comparative Example 24 was applied to watercolor paper together with water, no particular color separation was observed on the surface of the watercolor paper. This suggests that when colored resin beads with a particle diameter of approximately 0.4 μm are used instead of the first coloring material, the particle diameter is too small to allow the colored resin beads to set on the paper surface, and that it is difficult to intentionally achieve color separation in relation to the color pigment of the second coloring material.

Claims

1. A paint comprising a first colorant which is a colored resin bead having a particle diameter of 1.0 μm or more, a second colorant which is a particulate colored pigment having a particle diameter of 0.5 μm or less, and a particulate extender pigment, wherein the second colorant exhibits a hue different from that of the first colorant.

2. The paint according to claim 1, wherein the extender pigment has a specific gravity at 25°C greater than that of the first colorant.

3. The paint according to claim 1 or 2, wherein the extender pigment contains chalk.

4. The paint according to claim 1 or 2, wherein the first colorant is the colored resin bead containing a fluorescent dye, and the second colorant is the non-fluorescent colored pigment.

5. The paint according to claim 1 or 2, wherein the hue exhibited by the first colorant and the hue exhibited by the second colorant are separated by 90° or more and 270° or less in the hue circle of the Munsell color system.

6. The paint according to claim 1 or 2, which is a solid paint.

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