Pigment

Abstract

The pigment according to the present invention comprises: a first colorant which is colored resin beads having a particle size of 1.0 [mu] m or more; a second coloring material which is a granular coloring pigment having a particle diameter of 0.5 [mu] m or less; and a particulate extender pigment, the second pigment exhibiting a different hue from the first pigment.

Description

Cross Reference to Related Applications

[0001] This application claims priority from Japanese Patent Application No. 2024-006249, the content of which is incorporated into this specification by reference. TECHNICAL FIELD

[0002] The present application relates to a pigment that easily exhibits color separation. BACKGROUND

[0003] Patent Literature 1 discloses a pigment composition characterized by containing a coloring pigment and a body pigment, and the body pigment is a particle having a uniform shape. In this pigment composition, as the body pigment, light calcium carbonate having a uniform shape is used. As explained in Patent Literature 1, in this pigment composition, unlike the case where heavy calcium carbonate having an irregular shape is used as the body pigment, since the coating film coated on a drawing paper or the like can be made thick, the covering power can be improved, and the hiding power of the coloring pigment can be effectively improved.

[0004] Prior Art Documents

[0005] Patent Literature

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2000-72988 SUMMARY

[0007] Problems to be Solved by the Invention

[0008] On the other hand, in developing a pigment, in order to adjust the hue exhibited by the pigment, two or more color materials are sometimes mixed to trial-produce a pigment. However, at present, it is desired that a pigment exhibit one hue that is uniform without color difference. Therefore, a pigment that has color difference and is not uniform is judged to have a quality problem. If this judgment criterion is changed, a pigment that easily exhibits color separation is developed with intention, and such a developed pigment becomes a new tool that easily exhibits a plurality of colors when, for example, drawing is performed, and thus is expected.

[0009] Therefore, an object of the present application is to provide a pigment that easily exhibits color separation with intention.

[0010] Means for Solving the Problems

[0011] In order to solve the above problems, a pigment of one embodiment includes: a first color material that is a coloring resin bead having a particle diameter of 1.0 μm or more; a second color material that is a particulate coloring pigment having a particle diameter of 0.5 μm or less; and a particulate body pigment, the second color material exhibiting a different hue from the first color material. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a photograph showing an example of a state in which, when the pigment of Example 2 is applied to a watercolor paper together with water, the site where the hue (fluorescent red) exhibited by the first colorant appears is separated from the site where the hue (non-fluorescent blue) exhibited by the second colorant appears on the watercolor paper. DETAILED DESCRIPTION

[0013] The pigment of one embodiment (hereinafter also referred to as "the present pigment") is a watercolor pigment (pigment composition for watercolor painting) containing a first colorant, a second colorant, and a body pigment.

[0014] Generally, a watercolor pigment is applied to a paper together with water at the time of use. The paper is a material containing a large amount of cellulose fibers (fibers mainly composed of cellulose), and when water is added thereto, the water penetrates into the gaps between the cellulose fibers, which are hydrophilic, and the porous cellulose fibers absorb the water by capillary phenomenon, and the paper is dyed with the water. At this time, among the particles of the colorant contained in the pigment, the particles having a smaller particle diameter are more likely to spread to a large area of the paper together with the water and spread in a halo manner until the paper is dried. On the other hand, the particles having a larger particle diameter are less likely to spread to a large area of the paper and remain in the site where the pigment is applied to the paper.

[0015] The first colorant is a colored resin bead (hereinafter also referred to as "colored resin bead") colored with a dye or a coloring pigment, and is generally used for coloring. As the colored resin bead colored with a dye, for example, a resin bead obtained by subjecting a polymer microparticle water dispersion prepared using a styrene resin, an acrylic resin, an acrylonitrile resin, or a copolymer resin having these resins as main components, etc. to a dyeing treatment with an arbitrary dye can be exemplified. The dye here can be a non-fluorescent dye or a dye containing a fluorescent coloring matter. In the case where a dye containing a fluorescent coloring matter is used, the obtained colored resin bead exhibits a fluorescent color. In addition, the dye is fixed to the colored resin bead to become a state substantially insoluble in water. Alternatively, as the colored resin bead colored with a coloring pigment, for example, a resin bead obtained by mixing a resin such as an acrylic resin, a polyurethane resin, or a polyester resin with a coloring pigment, and sealing the coloring pigment into a cured resin bead by a resin bead-making method can be exemplified. As the coloring pigment sealed into the resin bead here, for example, the coloring pigments exemplified in the description of the second colorant described later can be exemplified. In addition, various colored resin beads are commercially available. The first colorant can also be a commercially available colored resin bead.

[0016] The particle diameter of the colored resin beads in the first colorant is 1.0 μm or more, based on the viewpoint of inhibiting the wide spread of the colored resin beads together with water to the paper. The particle diameter of the colored resin beads in the first colorant may also 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, based on the same viewpoint. On the other hand, the larger the particle diameter, the more difficult it is for the particle to adhere to the paper on which the pigment has been applied, and the more easily it falls off from the paper. In order to avoid the falling, the particle diameter of the colored resin beads in the first colorant may also 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. Thus, the particle diameter of the colored resin beads in the first colorant may be, for example, 1.0 μm or more and 20 μm or less, or 2.0 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 8.0 μm or less.

[0017] The "particle diameter" in the present specification means the particle diameter (Median Diameter D50) at the cumulative value of the cumulative particle size distribution on a volume basis reaching 50% according to the method prescribed in JIS Z 8825:2013 (Particle Size Analysis - Laser Diffraction / Scattering Method). 50 (Median Diameter). The particle diameter can be measured using a laser diffraction scattering method particle size distribution measuring device or the like, with the colored resin beads or the pigment as a sample. In addition, in a composition containing one or more kinds of colored resin beads and a plurality of pigments, such as the present pigment, when the particle diameter of a certain kind of colored resin bead or the particle diameter of a pigment is measured, the composition is subjected to centrifugal separation, and the particles of the colored resin beads or the particles of the pigment are fractionated from the composition according to the specific gravity of the particles, and the particles contained in each fraction obtained are extracted and used as a sample for the above method. Further, when each particle contained in a certain fraction obtained by centrifugal separation is observed with the naked eye or an optical microscope, in the case where two or more kinds of particles are observed (for example, in the case where a particle of a red colored resin bead and a particle of a blue colored pigment are observed in a certain fraction), the centrifugal separation and fractionation are performed again in such a manner that the two or more kinds of particles are further separated according to the specific gravity of the materials, and the colored resin beads or the pigment collected from the fractionated fraction are measured as a sample.

[0018] The specific gravity of the first colorant at 25°C can be, for example, 2.5 or less, and can also be 2.0 or less. On the other hand, the smaller the specific gravity, the more easily the particles float in the coating film formed by applying the present pigment to paper together with water, and the longer the time required for the particles to settle in the coating film. Therefore, it can be considered that the particles with a smaller specific gravity settle after the particles of the extender pigment described later have settled. As a result, the particles with a smaller specific gravity settle on the particles of the extender pigment that have settled and accumulated first, and thus are blocked by the particles of the extender pigment and are difficult to penetrate into the gaps between the paper fibers, and the spread of the particles to a wide area of the paper can be suppressed. Thus, in order to easily fix the first colorant to the paper surface, the specific gravity of the first colorant at 25°C is preferably 1.5 or less, and more preferably 1.3 or less. The specific gravity of the first colorant at 25°C can also be, for example, greater than 1.0.

[0019] The "specific gravity" in the present specification is a measured value of the true specific gravity of the colored resin beads or the pigment at 25°C, measured according to the method prescribed in JIS K 0061:2001 (Method of testing density and specific gravity of chemical products). The true specific gravity of the colored resin beads or the pigment at 25°C can be measured by the pycnometer method using a commercially available pycnometer with a cover-Lussac thermometer. In a composition containing colored resin beads, a plurality of pigments, such as the present pigment, when measuring the specific gravity of a certain colored resin bead or a certain pigment, the measurement method of the particle diameter can be fractionated by centrifugal separation as described above, and the colored resin beads or the pigment collected from the obtained fractions can be measured for the specific gravity as a sample.

[0020] On the paper on which the present pigment is applied, in order to more clearly exhibit the state of color separation, the first colorant can also be colored resin beads of a fluorescent pigment containing an inorganic substance. As the fluorescent pigment of an inorganic substance, for example, a metal oxide doped with a rare earth element can be cited. Alternatively, from the viewpoint that the particles with a smaller specific gravity are more easily blocked by the gaps of the paper and the state of color separation is more easily exhibited, the first colorant is more preferably colored resin beads of a fluorescent dye containing an organic substance. The fluorescent dye is a dye that exhibits color mainly by photoluminescence, and emits light upon passing through an excited state based on absorbed light and returning to a ground state. As the fluorescent dye of an organic substance, for example, merocyanine, perylene, acridine, luciferin, pyranine, Stilbene, Rhodamine, Coumarin, Fluorescein, or Umbelliferone, and the like can be cited, and the examples shown herein are not limited thereto.

[0021] The first colorant can be composed of only one kind of colored resin beads having a particle diameter of 1.0 μm or more, or can be composed of two or more kinds of colored resin beads each having a particle diameter of 1.0 μm or more in combination. In order to make the hue exhibited by the first colorant to be significantly apparent on a paper surface, the content of the first colorant in the present pigment can be, for example, 5% by mass or more or 10% by mass or more, preferably 15% by mass or more or 20% by mass or more, and more preferably 25% by mass or more. In addition, in order to avoid a case where the hue exhibited by the first colorant is too apparent on a paper surface, and the hue exhibited by the second colorant becomes unapparent in comparison, the content of the first colorant in the present pigment can be, for example, 40% by mass or less or 35% by mass or less, preferably 32% by mass or less, and more preferably 30% by mass or less. Thus, the content of the first colorant in the present pigment can 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.

[0022] The "content" described in the present specification means, except for cases where a description related to water is made (for example, Tables 1 and 3 described later, etc.), a content obtained by conversion based on a solid content (that is, a content of a dry mass not including water). In other words, unless otherwise specifically noted in relation to water, the content value of each component in the present pigment can also be understood as a content value of each component in the pigment when, in a dry environment, each component is gently dried at room temperature until the entire body is uniformly dried and a constant weight is maintained. The "room temperature" in the present specification is a certain temperature in a range of 5°C or more and 35°C or less. In addition, in a case where a component whose content is indicated in the present pigment includes two or more kinds, the "content" in the present specification means a "total content" of the two or more kinds. For example, in a case where the colored resin beads corresponding to the first colorant in the present pigment include two or more kinds, the description of "the content of the first colorant" means a total content of the two or more kinds of colored resin beads.

[0023] The second colorant is a particulate colored pigment or a mixture of two or more kinds of colored pigments which is not soluble in water or oil and is generally used for coloring. In order to make the second colorant easily spread over a wide range of paper compared to the first colorant, the particle diameter of the second colorant is 0.50 μm or less, for example, can be 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 can be, for example, 0.05 μm or more, preferably 0.10 μm or more, and more preferably 0.15 μm or more. Thus, the particle diameter of the second colorant can be, for example, 0.05 μm or more and 0.50 μm or less, or 0.05 μm or more and 0.40 μm or less, preferably 0.10 μm or more and 0.30 μm or less, and more preferably 0.15 μm or more and 0.25 μm or less.

[0024] In order to make the state in which the part in which the hue presented by the first color material is thick and the part in which the hue presented by the second color material is thick are separately presented on the paper surface more obvious, the ratio of the particle diameter of the colored resin beads in the first color material to the particle diameter of the colored pigment in the second color material (particle diameter of the colored resin beads in the first color material (μm) / particle diameter of the colored pigment in the second color material (μm)) can be, for example, 5.0 or more, preferably 10 or more, more preferably 20 or more, and further preferably 30 or more.

[0025] The specific gravity of the second color material at 25°C can be, for example, 2.6 or less, 2.4 or less, or 2.3 or less, and can also be 1.6 or more, 1.8 or more, or 2.0 or more. In order to make the colored pigment in the second color material more easily diffuse to a large area of the paper, the specific gravity of the second color material at 25°C is preferably greater than the specific gravity of the first color material at 25°C. In the case where the specific gravity of the second color material is large, in the coating film in which the present pigment is applied to the paper, the particles of the colored pigment in the second color material are precipitated on the paper surface first, compared to the particles of the colored resin beads in the first color material, and are penetrated into the gaps between the constituent fibers of the paper together with water, and thus the particles of the colored pigment in the second color material are more easily diffused to a large area of the paper. From the same viewpoint, the specific gravity of the second color material at 25°C is more preferably 1.3 times or more, and further preferably 1.6 times or more, of the specific gravity of the first color material at 25°C.

[0026] The second color material can also be a non-fluorescent and colored particulate inorganic pigment. The non-fluorescent and colored particulate inorganic pigment is preferred from the viewpoint of high hiding power, excellent light resistance and heat resistance, and a large specific gravity, compared to the non-fluorescent and colored particulate organic pigment described later. As the material of the white inorganic pigment, for example, titanium oxide, white lead (basic lead carbonate), zinc white (zinc oxide), or lithopone (barium sulfate / zinc sulfide) or the like can be exemplified. As the material of the red inorganic pigment, for example, red lead (iron (III) oxide), white lead (lead oxide), vermilion (mercury sulfide), or molybdate red or the like can be exemplified. As the material of the yellow inorganic pigment, for example, chrome yellow (lead chromate), cadmium yellow (cadmium sulfide), zinc chrome yellow (zinc chromate), lead yellow (lead monoxide) or the like can be exemplified. As the material of the blue inorganic pigment, for example, ultramarine, Prussian blue (ferric ferrocyanide), or cobalt blue or the like can be exemplified. As the material of the black inorganic pigment, for example, iron black (iron (II, III) oxide) or carbon black or the like can be exemplified.

[0027] The second colorant can be a non-fluorescent and colored particulate organic pigment. The non-fluorescent and colored particulate organic pigment is preferred because it is mostly bright in color compared to the non-fluorescent and colored particulate inorganic pigment. As the material of the colored organic pigment, for example, polycyclic pigments, azo pigments, precipitated pigments, and the like can be listed. As the material of the yellow polycyclic pigment, for example, isoindolinone, isoindoline, methine, anthraquinone, anthrone, xanthene, and the like can be listed. As the material of the orange polycyclic pigment, for example, diketopyrrolopyrrole, anthrone, perinone, quinacridone, and the like can be listed. As the material of the red polycyclic pigment, for example, quinacridone, diketopyrrolopyrrole, anthraquinone, perinone, indigo, and the like can be listed. As the material of the violet polycyclic pigment, for example, dioxazine, quinacridone, anthrone, xanthene, and the like can be listed. As the material of the blue polycyclic pigment, for example, phthalocyanine, anthraquinone, indigo, and the like can be listed. As the material of the green polycyclic pigment, for example, methine, and the like can be listed.

[0028] The second colorant can be one coloring pigment selected from, for example, 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 coloring pigments. In order to more easily visually distinguish the state in which the hue represented by the first colorant and the hue represented by the second colorant are separately expressed, it is preferred that the first colorant be a colored resin bead containing a fluorescent coloring agent and the second colorant be a non-fluorescent and particulate coloring pigment. In the present specification, "non-fluorescent" means that the coloring pigment represents color by absorption and reflection of light, that is, does not represent color by photoluminescence. In other words, the "non-fluorescent and particulate coloring pigment" can also be called a particulate coloring pigment not containing a fluorescent coloring agent.

[0029] On a paper on which the present pigment is applied, in order to more easily visually distinguish the state in which the hue represented by the first colorant and the hue represented by the second colorant are separately expressed, the second colorant is a coloring pigment representing a different hue from the first colorant. In designing the present pigment, as the second colorant, a coloring pigment representing a different hue from the hue represented by the first colorant can be selected. Here, "different hue" means that a normal person who has not been diagnosed as having color vision deficiency can visually recognize that the hue represented by the first colorant and the hue represented by the second colorant are different from each other when the present pigment is applied to a paper and the person visually recognizes the color of the part where the first colorant is represented and the color of the part where the second colorant is represented.

[0030] In order to visually more easily recognize a state in which the hue presented by the first color material and the hue presented by the second color material are presented separately, the hue presented by the first color material and the hue presented by the second color material are preferably separated by 90° or more and 270° or less in a hue circle of the Munsell hue system, more preferably separated by 120° or more and 240° or less, and further preferably separated by 150° or more and 210° or less. The hue circle of the Munsell hue system can be based on JIS Z 8721-1993 (Representation of Colors - Representation Based on Three Attributes), and can be any one of a 10-hue circle, a 24-hue circle, or a 100-hue circle, for example.

[0031] As the combination of the hue presented by the first color material and the hue presented by the second color material, since the separation of colors can be made more obvious by presenting colors in contrast by combining a warm color system and a cold color system, for example, combinations of red (R) and cyan green (BG), yellow red (YR) and cyan (B), yellow (Y) and violet cyan (PB), yellow green (GY) and violet (P), green (G) and red violet (RP), cyan green (BG) and red (R), cyan (B) and yellow red (YR), violet cyan (PB) and yellow (Y), violet (P) and yellow green (GY), or red violet (RP) and green (G) can be cited. In addition, since the separation of colors can be made more obvious by the combination of the first color material presenting a warm color system of a fluorescent hue and the second color material presenting a cold color system of a non-fluorescent hue, it is more preferable that the first color material be a colored resin bead of a fluorescent colorant including an organic substance selected from red (R), yellow red (YR), and yellow (Y), and the second color material be a non-fluorescent colored pigment selected from cyan green (BG), cyan (B), and violet cyan (PB). The specific combination of hues is not limited to the examples cited here.

[0032] In order to make the hue presented by the second color material appear more obviously on the paper, the content of the second color material in the present pigment can be 1.0% by mass or more, for example, preferably 2.0% by mass or more, and more preferably 3.0% by mass or more. In addition, in order to avoid a situation in which the hue presented by the second color material is too obvious and the hue presented by the first color material becomes relatively less obvious, the content of the second color material in the present pigment can be 30% by mass or less or 20% by mass or less, for example, preferably 15% by mass or less or 10% by mass or less, and more preferably 5.0% by mass or less. Thus, the content of the second color material in the present pigment can be 1.0% by mass or more and 30% by mass or less, for example, preferably 2.0% by mass or more and 15% by mass or less, and more preferably 3.0% by mass or more and 5.0% by mass or less.

[0033] In order to make the hue presented by the first color material clearly appear on the paper surface, the content ratio of the first color material to the second color material (content of the first color material / content of the second color material) in the present pigment may, for example, be 1.0 or more, 2.0 or more, or 3.0 or more, preferably 4.0 or more or 5.0 or more, more preferably 6.0 or more or 7.0 or more. In order to make the hue presented by the second color material clearly appear on the paper surface, the content ratio of the first color material to the second color material (content of the first color material / content of the second color material) in the present pigment may, for example, be 10.0 or less or 9.0 or less, preferably 8.0 or less. In order to make both the hue presented by the first color material and the hue presented by the second color material clearly, the content ratio of the first color material to the second color material (content of the first color material / content of the second color material) in the present pigment is preferably 4.0 or more and 10.0 or less, more preferably 6.0 or more and 8.0 or less.

[0034] Extender pigments are pigments that are high in transparency and weak in hiding power, and have a property that makes it difficult to use them as coloring pigments. Extender pigments are usually incorporated in pigments for the purpose of increasing the volume, diluting or reinforcing the coating film, etc. The colored resin beads or coloring pigments are not extender pigments in the present pigment. As the material of the extender pigments, for example, barite (barium sulfate), precipitated barium sulfate, gypsum (hydrated calcium sulfate), kaolin (high clay), silica (silicon dioxide), white carbon (precipitated silica), talc (Talc), barium carbonate or calcium carbonate, etc. can be listed.

[0035] In order to make the particles of the colored resin beads in the first color material easily blocked by the gaps of the paper on the paper surface, the particle diameter of the extender pigment in the present pigment may, for example, be 3.0 μm or more, preferably 4.0 μm or more, more preferably 5.0 μm or more. In order to avoid the particles from falling off the paper surface, the particle diameter of the extender pigment may, for example, be 20 μm or less or 15 μm or less, preferably 10 μm or less or 8.0 μm or less, more preferably 6.0 μm or less. Thus, the particle diameter of the extender pigment may, for example, be 3.0 μm or more and 20 μm or less, preferably 4.0 μm or more and 10 μm or less, more preferably 5.0 μm or more and 6.0 μm or less.

[0036] The specific gravity of the extender pigment in the present pigment at 25°C is not particularly limited as long as it does not depart from the object of the present invention, and may, for example, be 4.0 or less, 3.5 or less, 3.0 or less, or 2.8 or less, and may be 1.8 or more, 2.0 or more, 2.2 or more, or 2.4 or more. In order to make the first color material easily blocked by the gaps of the paper on the paper surface, it is preferable that the extender pigment in the present pigment have a specific gravity at 25°C that is larger than that of the first color 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 further preferably 2.0 times or more, of the specific gravity of the first color material at 25°C.

[0037] In order to more clearly exhibit color separation in a paper coated with the present pigment, the extender of the present pigment preferably uses a pigment crushed from a mineral or a shell. As an extender crushed from a mineral, for example, white clay (kaolin) can be mentioned. As an extender crushed from a shell, for example, gofun can be mentioned. Such a pigment (e.g., gofun) has a particle size that is larger, irregular, and each particle has a different shape, as compared to a particle of a chemically synthesized extender (e.g., light calcium carbonate). Although the mechanism by which the use of such an extender having a particle shape that is not uniform more easily exhibits color separation is not clear, it can be assumed that in a coating film formed by coating the present pigment on a paper, the particles of the extender having a particle shape that is not uniform settle and accumulate on the paper surface to form a layer, and in this layer, gaps of a certain size that are difficult for the particles of the coloring resin beads in the first colorant to pass through, but are easy for the particles of the coloring pigment in the second colorant to pass through, are easily formed. Thus, the first colorant is blocked by the extender layer on the paper surface and is difficult to spread to a wide area of the paper, while the second colorant passes through the gaps formed by the extender layer, enters the gaps between the fibers constituting the paper, and easily spreads to a wider area of the paper with water in a bleeding manner.

[0038] Based on the same viewpoint, the extender in the present pigment is more preferably gofun. The particle size of gofun can be, for example, 3.0 μm or more and 20 μm or less, or 4.0 μm or more and 15 μm or less, and is preferably 5.0 μm or more and 10 μm or less. In order to easily exhibit color separation, it is more desirable that the particles of gofun contain scale-like particles when observed under a microscope. In other words, the extender in the present pigment more preferably contains scale-like calcium carbonate particles. Based on the same viewpoint, the aspect ratio (length of long side (μm) of the face / length of short side (μm) of the face orthogonal to the long side) of the approximately rectangular face formed by the scale-like particles of gofun can be, for example, greater than 1.5, and is preferably 2.0 or more, and more preferably 3.0 or more. Gofun containing such scale-like particles, according to the aforementioned mechanism, more effectively blocks the particles of the coloring resin beads in the first colorant from spreading on the paper surface by the layer of gofun, and the shape of the coloring pigment particles in the second colorant more easily allows the coloring pigment particles to pass through the gaps formed by the gofun layer. Thus, the coloring pigment particles of the second colorant more easily spread to a wider area of the paper with water.

[0039] In the present pigment, one kind of extender pigment alone or two or more kinds of extender pigments can be contained. Since the color separation becomes more conspicuous by effectively blocking the first color material on the paper surface, the content of the extender pigment in the present pigment can be, for example, 5.0% by mass or more, preferably 10% by mass or more, and more preferably 15% by mass or more. In addition, in order to avoid the case where the extender pigment is peeled off from the paper surface, the content of the extender pigment in the present pigment can be, for example, 30% by mass or less, preferably 25% by mass or less, and more preferably 20% by mass or less. Thus, the content of the extender pigment in the present pigment can be, for example, 5.0% by mass or more and 30% by mass or less, preferably 10% by mass or more and 25% by mass or less, and more preferably 15% by mass or more and 20% by mass or less.

[0040] The present pigment can further contain one or more kinds of substances selected from the group consisting of water-soluble high molecular compounds, amphiphilic high molecular compounds, wetting agents, antiseptic and antimildew agents, drying accelerators, surfactants, dispersants, antifoaming agents, and water, in addition to the first color material, the second color material, and the extender pigment, as needed.

[0041] The water-soluble high molecular compounds and the amphiphilic high molecular compounds function to impart dispersibility and fixability to the present pigment. As the water-soluble high molecular compounds, for example, gum arabic, dextrin, or carboxymethyl cellulose, etc. can be exemplified. As the amphiphilic high molecular compounds, for example, vinyl acetate-acrylic acid copolymer, etc. can be exemplified. These high molecular compounds can be used alone or in combination with two or more kinds. From the viewpoint of more easily imparting dispersibility and fixability to the pigment, the content of one or more kinds of high molecular compounds selected from the group consisting of water-soluble high molecular compounds and amphiphilic high molecular compounds in the present pigment can be, for example, 5% by mass or more, or 10% by mass or more, and preferably 20% by mass or more. Further, as described later, in the case where the present pigment is in a solid form, the content of one or more kinds of high molecular compounds selected from the group consisting of water-soluble high molecular compounds and amphiphilic high molecular compounds is more preferably 35% by mass or more, and further preferably 40% by mass or more. In addition, in order to avoid the case where the viscosity of the present pigment is excessively high, the content of one or more kinds of high molecular compounds selected from the group consisting of water-soluble high molecular compounds and amphiphilic high molecular compounds in the present pigment can be, for example, 60% by mass or less, preferably 55% by mass or less, and more preferably 50% by mass or less. Thus, the content of one or more kinds of high molecular compounds selected from the group consisting of water-soluble high molecular compounds and amphiphilic high molecular compounds in the present pigment can 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 further preferably 40% by mass or more and 50% by mass or less.

[0042] The wetting agent is a substance for appropriately maintaining the water content in the pigment, and for improving the dispersibility into water at the time of use. As the wetting agent, for example, compounds such as glycerin, ethylene glycol, propylene glycol, or polyethylene glycol can be exemplified. These compounds can be used alone, or two or more kinds can be used simultaneously. The content of the wetting agent in the present pigment can be, for example, 3.0% by mass or more, preferably 4.0% by mass or more, from the viewpoint of maintaining the water content and improving the resolubility. In addition, in order to avoid the case where the present pigment dries too slowly, the content of the wetting agent in the present pigment can be, for example, 40% by mass or less, or 30% by mass or less, preferably 20% by mass or less, more preferably 10% by mass or less. Thus, the content of the wetting agent in the present pigment can 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, more preferably 4.0% by mass or more and 10% by mass or less.

[0043] The preservative and mildewcide can use a preservative and mildewcide that has been conventionally used for pigments. As the preservative and mildewcide, for example, compounds such as phenol, dimethylphenol, formaldehyde, potassium sorbate, sodium dehydroacetate, methyl benzoate, dithio-2,2'-bis(benzylformamide), 2-methylisothiazolin-3-one, 2-(4-thiazolyl)benzimidazole, 2-thiocyanomethylthiobenzothiazole can be exemplified. These compounds can be used alone, or two or more kinds can be used simultaneously. The content of the preservative and mildewcide in the present pigment can be, for example, 0.01% by mass or more, or 0.05% by mass or more, and, in addition, can be, for example, 5.0% by mass or less, or 1.0% by mass or less.

[0044] The drying accelerator, surfactant, dispersant, and defoaming agent can use a kind that has been conventionally used for pigments, and can be added to the present pigment in the same proportion as in the conventional pigments. In the case where the present pigment is manufactured in a tube form, water can be added to the present pigment in an appropriate amount. However, for the present pigment in a tube form which has a high water content and becomes low viscosity, the problem of separation of each pigment by specific gravity can occur at a stage before mixing with water for use. In order to solve this problem, it is preferable that the present pigment be in a solid pigment form. The water content in the solid pigment is not particularly limited as long as the object of the present application is not deviated from, and can be, for example, 10% by mass or less, or 5% by mass or more and 9% by mass or less. The solid pigment is a watercolor pigment existing in a solid state, and is also called a solid watercolor pigment or a color paint. The user can utilize the property that the solid pigment is soluble in water, and can cause the solid pigment to exhibit different color tones, gradation, bleeding, and the like on a paper surface depending on the amount of water added to the solid pigment.

[0045] In the case of producing the present pigment in a solid pigment form, the present pigment in a high-viscosity liquid form is gently dried at ordinary temperature to remove most of the water. In the case of drying the present pigment in a liquid form at ordinary temperature, until the present pigment in a liquid form solidifies, in order to avoid the occurrence of a case where various pigments contained in the present pigment in a liquid form are precipitated and separated according to specific gravity, it is preferable to dry the present pigment in a liquid form in which the content of one or more selected from the water-soluble polymer compound and the amphiphilic polymer compound is 35% by mass or more at ordinary temperature to produce the present pigment in a solid pigment form. In addition, in the obtained present pigment in a solid pigment form, in order to avoid the occurrence of unnatural depressions on the surface, it is preferable to dry the present pigment in a liquid form in which the content of one or more selected from the water-soluble polymer compound and the amphiphilic polymer compound is 40% by mass or more at ordinary temperature to produce the present pigment in a solid form.

[0046] The present pigment can also contain coloring pigments having a particle diameter larger than 0.5 μm, i.e., other pigments, as long as the object of the present invention is not deviated. The upper limit of the particle diameter of the other pigments can also be the same as the upper limit of the particle diameter described in the description of the first pigment. However, in order to make the separation of the color tone exhibited by the first pigment and the color tone exhibited by the second pigment more clearly appear on the paper surface, the content of the other pigments in the present pigment can 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 viewpoint, it is preferable that the present pigment be a composition containing substantially no other pigments in addition to the first pigment and the second pigment.

[0047] As an object to which the present pigment is applied, there is no particular limitation as long as the surface thereof can be drawn with a brush and watercolor pigments, and paper is preferable. As the paper, for example, drawing paper, watercolor paper, and paper, Kent paper, or printing paper (high-quality paper) and the like can be exemplified. The paper is paper produced by papermaking a raw material in a slurry form, the raw material being a fiber obtained by beating a raw plant such as mulberry, paper mulberry, white willow, hemp, conifer, broadleaf tree, or bamboo leaf. If the present pigment is applied to the paper, the second pigment can be diffused on the paper surface in a manner of bleeding together with water, and there is no particular limitation to the basis weight of the paper, which can be, for example, 5 g / m 2 or more and 200 g / m 2 or more and 200 g / m 2 or more and 200 g / m 2 or more and 200 g / m

[0048] The following matters are included in the disclosure of the present specification. (1)

[0050] A pigment comprising:

[0051] the first color material is a colored resin bead having a particle diameter of 1.0 μm or more;

[0052] the second color material is a particulate colored pigment having a particle diameter of 0.5 μm or less; and

[0053] the particulate extender pigment,

[0054] the second color material and the first color material exhibit different hues. (2)

[0056] The pigment as described in (1), wherein the specific gravity of the particulate extender pigment at 25°C is greater than that of the first color material. (3)

[0058] The pigment as described in (1) or (2), wherein the particulate extender pigment contains red lead. (4)

[0060] The pigment as described in any one of (1) to (3), wherein the first color material is the colored resin bead containing a fluorescent pigment, and the second color material is the non-fluorescent colored pigment. (5)

[0062] The pigment as described in any one of (1) to (4), wherein the hue exhibited by the first color material and the hue exhibited by the second color material are separated from each other by 90° or more and 270° or less in a hue circle of the Munsell hue system. (6)

[0064] The pigment as described in any one of (1) to (5), wherein the pigment is a solid pigment.

[0065] According to the pigment as described in (1), if the pigment is applied to paper in a water-containing state, the particulate colored pigment as the second color material easily penetrates and diffuses into the gaps between the fibers constituting the paper together with water because the particle diameter of the particulate colored pigment is relatively small. On the other hand, the colored resin bead as the first color material is easily interfered with by the particulate extender pigment and blocked by the gaps of the paper because the particle diameter of the colored resin bead is relatively large, and thus it is difficult to penetrate into the gaps between the fibers constituting the paper and difficult to diffuse. That is, on the paper on which the pigment is applied, the particulate colored pigment as the second color material easily diffuses into a large area of the paper compared with the colored resin bead as the first color material. Therefore, in the paper on which the pigment is applied, the portion where the hue exhibited by the first color material is relatively strong and the portion where the hue exhibited by the second color material is relatively strong are easily exhibited independently. Thus, a pigment in which color separation is more easily consciously exhibited can be provided.

[0066] The present application is not limited to the above-described embodiments, and various modifications, corrections, or variations can be made based on the knowledge of those skilled in the art without departing from the spirit of the present application. In the present application, the same effects or advantages can be achieved even if a certain specific matter is replaced with another technology.

[0067] Examples

[0068] The present application is described below using examples, but the present application is not limited to the examples.

[0069] As the colored resin beads having a particle size of 1.0 μm or more, i.e., the first color material, the following commercially available products were prepared.

[0070] SX-103 (manufactured by SINLOIHI Co., Ltd., colored resin beads containing a red organic fluorescent pigment)

[0071] SX-104 (manufactured by SINLOIHI Co., Ltd., colored resin beads containing an orange organic fluorescent pigment)

[0072] SX-105 (manufactured by SINLOIHI Co., Ltd., colored resin beads containing a yellow organic fluorescent pigment)

[0073] SX-117 (manufactured by SINLOIHI Co., Ltd., colored resin beads containing a peach organic fluorescent pigment)

[0074] In addition, the product series of these colored resin beads containing an organic fluorescent pigment is described in the product description as having an average particle size of 4 μm to 6 μm. In addition, the inventors of the present application measured the particle sizes of these colored resin beads containing an organic fluorescent pigment by the above-described method, and obtained, for example, a 10% particle size D 10 of 3.65 μm; a median particle size D 50 (median diameter) of 6.67 μm; and a 90% particle size D 90 of 11.6 μm. In addition, the specific gravities at 25°C of SX-103, SX-104, SX-105, and SX-117, which were measured by the above-described method, were all 1.2.

[0075] As the particulate colored pigment having a particle size of 0.50 μm or less, i.e., the second color material, the following commercially available products were prepared.

[0076] SA Blue DY-12K (manufactured by GOKUNAI COLOR Co., Ltd., blue non-fluorescent organic pigment)

[0077] SA Green DY-4K (manufactured by GOKUNAI COLOR Co., Ltd., green non-fluorescent organic pigment)

[0078] High Micron Red #7356NB (produced by Gokoku Color Co., Ltd., red non-fluorescent organic pigment)

[0079] Blue FLGB Conc (produced by Dainichiseika Color & Chemicals Mfg. Co., Ltd., blue non-fluorescent organic pigment)

[0080] Green FLB Conc (produced by Dainichiseika Color & Chemicals Mfg. Co., Ltd., green non-fluorescent organic pigment)

[0081] Golden yellow FL4G Conc (produced by Dainichiseika Color & Chemicals Mfg. Co., Ltd., yellow non-fluorescent organic pigment)

[0082] Further, the particle diameter of SA Blue DY-12K measured by the method was 0.17 μm, and the specific gravity at 25°C measured by the method was 1.62. The particle diameter of SA Green DY-4K measured by the same method was 0.14 μm, and the specific gravity at 25°C was 2.1.

[0083] As other colorants, the following commercially available products were prepared. Further, "Bayferrox" is a registered trademark.

[0084] Rose #13FD: produced by Nippon Shokubai Co., Ltd., rose non-fluorescent organic pigment

[0085] Bayferrox 3920 (produced by LANXESS K.K., yellowish brown non-fluorescent inorganic pigment)

[0086] Bayferrox 110M (produced by LANXESS K.K., brown non-fluorescent inorganic pigment)

[0087] Cyan blue 82 (produced by Venator Co., blue non-fluorescent inorganic pigment)

[0088] Further, none of the other colorants prepared here were colorant beads, and the particle diameter measured by the method was at least greater than 0.5 μm, and was approximately 2.0 μm or more.

[0089] As particulate extender pigments, the following commercially available products were prepared. Further, the particle diameter of a typical titanium dioxide is about 2 μm to 6 μm.

[0090] Special flower printing titanium dioxide (produced by Nakagawa Titanium Dioxide Manufacturing Co., Ltd., powder obtained by pulverizing a natural scallop shell)

[0091] Barium sulfate P-30 (produced by Takehara Chemical Industry Co., Ltd., barium sulfate powder)

[0092] Further, when observed by optical microscope, the sumac powder contained a large number of scale-like calcium carbonate particles. In addition, when the particle diameter of the sumac powder was measured by the method, the 10% particle diameter D 10 was 1.55 μm, the median particle diameter D 50 was 5.42 μm, and the 90% particle diameter D 90 was 11.2 μm. In addition, when the specific gravity of the sumac powder at 25°C was measured by the method, it was 2.71.

[0093] As the water-soluble high molecular compound, the following commercially available products were prepared. In addition, "AMICOL" is a registered trademark.

[0094] Arabic gum SS (SUPER SOLUBLE GUM ARABIC) (manufactured by San-Ei Gen F.F.I., Inc., Arabic gum)

[0095] Red dextrin (manufactured by San-Ei Gen F.F.I., Inc., dextrin)

[0096] In addition, as the wetting agent, glycerin manufactured by Kawaguchi Co., Ltd. was prepared. Further, commercially available preservatives and antifoaming agents usually used for compounding with pigments were prepared. Water was directly used as tap water in Nara City, Nara Prefecture.

[0097]

Examples 1 to 8

[0098] First, as the base pigment, a medium component containing sumac powder was prepared by compounding as shown in Table 1 below.

[0099]

Table 1

[0100]

[0101] Next, the medium component containing sumac powder (Table 1), a first colorant containing a fluorescent pigment, and a second colorant which was not fluorescent were mixed by compounding as shown in Table 2 below. The obtained mixture was filled in a plastic container, and was gently dried at ordinary temperature together with the container, whereby solid watercolor pigments (dried color paints) of Examples 1 to 8 were respectively trial-produced. The water content in these solid watercolor pigments was measured, and it was found that the water content was about 8 mass%.

[0102]

Table 2

[0103]

[0104]

Examples 9 to 16

[0105] First, as the base pigment, a medium component containing barium sulfate was prepared by compounding as shown in Table 3 below.

[0106] [Table 3]

[0107]

[0108] Then, by compounding as shown in Table 4 below, the medium component containing barium sulfate (Table 3), the first colorant containing a fluorescent pigment, and the second colorant which is non-fluorescent were mixed. The resulting mixture was filled in a plastic container, and the mixture was gently dried at ordinary temperature together with the container, whereby the solid watercolor paint (dry color) of each of Examples 9 to 16 was trial-produced. The water content in each of the solid watercolor paints was measured, and the water content was found to be about 8 mass %.

[0109] [Table 4]

[0110]

[0111] [Comparative Examples 17 to 23]

[0112] By compounding as shown in Table 5 below, the medium component containing barium sulfate (Table 3), the other colorant which is non-fluorescent, and the second colorant which is non-fluorescent were mixed. The resulting mixture was filled in a plastic container, and the mixture was gently dried at ordinary temperature together with the container, whereby the solid watercolor paint (dry color) of each of Comparative Examples 17 to 23 was trial-produced. The water content in each of the solid watercolor paints was measured, and the water content was found to be about 8 mass %.

[0113] [Table 5]

[0114]

[0115] [Evaluation Test]

[0116] For each of the solid watercolor paints trial-produced as described above, in the container, the surface portion of the solid watercolor paint was gradually dissolved in water with a water-containing pen nib, and a small amount of the paint was taken out, mixed with a small amount of water on a plastic palette for drawing, and spread, and then the pen nib of a brush was used to sufficiently apply the mixture to a commercially available watercolor paper for writing. Thereafter, on the watercolor paper, at the portion written with the pen nib, the color phase exhibited by the first colorant or the color phase exhibited by the other colorant was visualized. At a portion on the watercolor paper slightly apart from the portion where the color phase was visualized, as the water permeated and diffused, the color phase exhibited by the second colorant was visualized. In a bright room, the watercolor paper was visually observed, and the brilliance of the color combination, the ease of recognition of the color separation, and the ease of the color separation were evaluated in four levels, and the evaluation results are shown in Tables 6 to 8 below.

[0117] Brilliance of color combination: evaluation criteria

[0118] AA The color difference between the two colors is particularly noticeable, easy to recognize, and the appearance is particularly bright.

[0119] A The color difference between the two colors is noticeable and the appearance is bright.

[0120] B Although the color matching is similar, the color difference between the two colors can be seen at a glance from the appearance.

[0121] C The colors are very similar, and the color difference cannot be distinguished without careful observation, and the appearance becomes unattractive.

[0122] Ease of recognition of color separation: evaluation criteria

[0123] AA When two colors are present as pigments as matched in pigments, a strong impression is left.

[0124] A Two colors can be seen at a glance.

[0125] B Two colors can be seen after careful observation.

[0126] C Even with careful observation, it is not possible to recognize that there are two colors.

[0127] Ease of color separation: evaluation criteria

[0128] AA The parts where the two colors are respectively developed are clearly separated on the watercolor paper.

[0129] A The parts where the two colors are respectively developed are adjacent, but the boundary is clearly recognizable.

[0130] B The parts where the two colors are respectively developed are adjacent, and the boundary is not easy to recognize.

[0131] C The two colors are respectively developed at almost the same part on the watercolor paper, and the boundary is not recognizable.

[0132]

Table 6

[0133]

[0134]

Table 7

[0135]

[0136]

Table 8

[0137]

[0138] In the pigments of Examples 1 to 8, the hue of the fluorescent color presented by the first color material and the hue of the non-fluorescent color presented by the second color material presented a state of clear separation on the watercolor paper, and a drawing performance with contrast, such as an aurora-like visual effect, was obtained. Figure 1A drawing rendered on watercolor paper by the pigments of Example 2 is shown in FIG. 1. On the watercolor paper, around the portion where the hue rendered by the first color material (fluorescent red) appeared Figure 1 in a manner exuding from the portion, the hue rendered by the second color material (non-fluorescent blue) appeared. Figure 1

[0139] In addition, in Examples 1 to 8 where whiting was used as the extender pigment, in comparison with Examples 9 to 16 where barium sulfate was used as the extender pigment, the hue of the fluorescent color rendered by the first color material was visually clearly separated from the hue of the non-fluorescent color rendered by the second color material. In addition, in Examples 1 to 16 where colored resin beads containing a fluorescent pigment were used as the first color material, in comparison with Comparative Examples 17 to 23 where non-fluorescent colored pigments were used as the other color material, the degree of brilliance of the color combination was more outstanding, a particularly beautiful visual effect was rendered, and a high evaluation was obtained.

[0140] Furthermore, in comparison with the aforementioned Examples 1 to 8, instead of the first color material used in Examples 1 to 8, in addition to using commercially available colored resin beads having a particle diameter of about 0.4 μm, Comparative Example 24 was also trial-produced as a solid watercolor pigment (dry color) by the same compounding and trial-production conditions. However, even if this Comparative Example 24 pigment was applied to watercolor paper together with water, no particular separation of colors was observed on the paper surface of the watercolor paper. Therefore, for the case where colored resin beads having a particle diameter of about 0.4 μm were used instead of the first color material, the following was suggested, that is, if the particle diameter is too small, the colored resin beads are difficult to be blocked by the gaps of the paper on the paper surface, and in relation to the colored pigments of the second color material, it is difficult to consciously express the separation of colors.​

Claims

1. A pigment comprising: The first colorant is a coloring resin bead with a particle size of 1.0μm or larger; The second colorant is a particulate coloring pigment with a particle size of less than 0.5 μm; and Granular extender pigments, The second pigment exhibits a different hue than the first pigment.

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

3. The pigment according to claim 1 or 2, wherein, The pigment contains charcoal.

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

5. The pigment according to claim 1 or 2, wherein, The hue of the first pigment and the hue of the second pigment are more than 90° and less than 270° apart in the Munsell color wheel.

6. The pigment according to claim 1 or 2, wherein, The pigment is a solid pigment.

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