Reversible thermochromic microencapsulated pigment, and composition, molded article, and laminate containing the same

Abstract

To provide a microcapsule pigment high in durability and high in color density.SOLUTION: A reversible thermochromic microcapsule pigment comprises microcapsules obtained by enclosing a reversible thermochromic composition with a film, wherein a volume-based average particle diameter (X) of the microcapsules is 0.1 to 5.0 μm and an average cutting cross-section film thickness (Y) obtained from the following formula of the microcapsule pigment: cutting cross-section film thickness=(cross-sectional outer peripheral diameter-cross-sectional inner peripheral diameter) / 2, (wherein the cross-sectional outer peripheral diameter and the cross-sectional inner peripheral diameter are, for one microcapsule, calculated from a circle equivalent diameters of an area of the region surrounded by the outer periphery of a film cross-section and an area of the region surrounded by the inner periphery of the cross-section of the film) is 0.02 to 1.0 μm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reversible thermochromic microencapsulated pigment. The present invention also relates to a composition containing the pigment, and a molded article and a laminate produced using the composition. [Background technology]

[0002] Several proposals have been disclosed in the past regarding reversible thermochromic microcapsule pigments encapsulating a reversible thermochromic composition consisting of a compatible solution of an electron-donating color-forming organic compound, an electron-accepting compound, and a reaction medium that reversibly induces an electron donor-acceptor reaction in a specific temperature range, as well as liquid compositions and molding resin compositions using the same (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-99628 [Patent Document 2] Japanese Patent Application Publication No. 2020-100710 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising (a) an electron-donating organic color-forming compound, (b) an electron-accepting compound, and (c) a reaction medium that reversibly induces an electron donating / accepting reaction between the components (a) and (b) in a specific temperature range, the reversible thermochromic microcapsule pigment having high color density upon color development and excellent durability of the coating (microcapsule wall film). [Means for solving the problem]

[0005] The reversible thermochromic microcapsule pigment according to the present invention comprises: (a) an electron-donating color-forming organic compound; (b) an electron-accepting compound; (c) a reaction medium that causes a reversible electron transfer reaction between the components (a) and (b) in a specific temperature range; A reversible thermochromic microcapsule pigment comprising microcapsules in which a reversible thermochromic composition comprising the compound is encapsulated in a coating, The microcapsules have a volume-based average particle size (X) of 0.1 to 5.0 μm, and the cross section of the frozen microcapsule pigment is observed with a transmission electron microscope, and the following formula is satisfied for all capsules within the observation field: Cut cross-section film thickness = (cross-section outer diameter - cross-section inner diameter) / 2 (In the formula, the outer diameter and inner diameter of the cross section are calculated from the equivalent circle diameters of the area of ​​the region surrounded by the outer periphery of the cross section of the coating and the area of ​​the region surrounded by the inner periphery of the cross section of one microcapsule.) and the average value is taken as the average cross-sectional thickness, the average cross-sectional thickness (Y) of the microcapsules is 0.02 to 1.0 μm. It is characterized by the following. The reversible thermochromic liquid composition according to the present invention is characterized by comprising the reversible thermochromic microcapsule pigment and a vehicle. The reversibly thermochromic solid molding for coating according to the present invention is characterized by comprising the reversibly thermochromic microcapsule pigment and an excipient. The reversible thermochromic molding resin composition is characterized by comprising the reversible thermochromic microcapsule pigment and a molding resin. The reversibly thermochromic laminate according to the present invention is characterized by comprising a support and a reversibly thermochromic layer containing the reversibly thermochromic microencapsulated pigment. [Effects of the Invention]

[0006] The present invention makes it possible to provide a microcapsule pigment that is excellent in durability and has a high color density by adjusting the volume-based average particle size and the average cross-sectional film thickness of the microcapsules contained in the reversible thermochromic microcapsule pigment within specific ranges, as well as a reversible thermochromic liquid composition, a reversible thermochromic solid molding for coating, a reversible thermochromic molding resin composition, and a reversible thermochromic laminate that use the same. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a graph illustrating the hysteresis characteristics in the color density-temperature curve of a reversibly thermochromic composition that is heat-discolorable. [Figure 2] 1 is a graph illustrating the hysteresis characteristics in the color density-temperature curve of a heat-discolorable, reversible thermochromic composition having color memory properties. [Figure 3] 1 is a graph illustrating the hysteresis characteristics in the color density-temperature curve of a reversibly thermochromic composition that develops color over time. DETAILED DESCRIPTION OF THE INVENTION

[0008] The microcapsule pigment according to the present invention comprises microcapsules, typically an aggregate of microcapsules. The microcapsules encapsulate a reversible thermochromic composition. This reversible thermochromic composition can be a thermally decolorizable (decolorizes upon heating and develops color upon cooling) reversible thermochromic composition containing at least three essential components: (i) an electron-donating color-forming organic compound, (ii) an electron-accepting compound, and (iii) a reaction medium that determines the temperature at which the color-forming reaction between components (i) and (ii) occurs.

[0009] An example of a reversible thermochromic composition to which the microcapsule pigment of the present invention can be applied is a composition described in Japanese Patent Publication Nos. 51-44706, 51-44707, and 1-29398, which changes color around a predetermined temperature (color change point), exhibiting a decolorized state in a temperature range above the high-temperature color change point and a colored state in a temperature range below the low-temperature color change point, with only one specific state existing at room temperature, and the other state being maintained while the heat or cold required to manifest that state is applied, but returning to the state it exhibits at room temperature when the application of heat or cold is removed, and which has a relatively small hysteresis width (ΔH) (ΔH=1 to 7°C) (see Figure 1).

[0010] Other examples of reversible thermochromic compositions to which the microcapsulated pigment of the present invention can be applied include those described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, JP-A-2005-1369, etc., which exhibit a large hysteresis width (ΔH=8 to 70°C), and in which the shape of the curve plotting the change in color density with temperature follows a significantly different path when the temperature is increased from a temperature lower than the color change temperature range than when the temperature is decreased from a temperature higher than the color change temperature range, and which exhibit color memory in a specific temperature range [the temperature range between the color development onset temperature t2 and the color loss onset temperature t3 (a temperature range in which two phases are essentially maintained)], where the color is developed in a temperature range below the complete color development temperature t1 or the color is lost in a high temperature range above the complete loss temperature t4 (see Figure 2).

[0011] [Microcapsule pigment] Components (a), (b) and (c) will be specifically explained below. Component (A), that is, the electron-donating color-forming organic compound, is the component that determines the color, and is a compound that donates electrons to component (B), which is the color developer, to develop color.

[0012] Examples of the electron-donating color-forming organic compound include phthalide compounds, fluoran compounds, styrinoquinoline compounds, diazarhodamine lactone compounds, pyridine compounds, quinazoline compounds, and bisquinazoline compounds, and among these, phthalide compounds and fluoran compounds are preferred. Examples of the phthalide compound include a diphenylmethane phthalide compound, a phenylindolyl phthalide compound, an indolyl phthalide compound, a diphenylmethane azaphthalide compound, a phenylindolyl azaphthalide compound, and derivatives thereof. Among these, the phenylindolyl azaphthalide compound and derivatives thereof are preferred. Examples of the fluoran compound include aminofluoran compounds, alkoxyfluoran compounds, and derivatives thereof.

[0013] Examples of compounds that can be used as component (a) are listed below. 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, 3,3-bis(1-n-butyl-2-methylindol-3-yl)phthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-n-hexyloxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-[2-ethoxy-4-(N-ethylanilino)phenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-acetamido-4-diethylaminophenyl)-3-(1-propyl-2-methylindol-3-yl)-4-azaphthalide, 3,6-bis(diphenylamino)fluoran, 3,6-bis(N-phenyl-Np-tolylamino)fluoran, 3,6-dimethoxyfluoran, 3,6-di-n-butoxyfluorane, 2-methyl-6-(N-ethyl-Np-tolylamino)fluoran, 3-chloro-6-cyclohexylaminofluoran, 2-methyl-6-cyclohexylaminofluoran, 2-chloroamino-6-di-n-butylaminofluoran, 2-(2-chloroanilino)-6-di-n-butylaminofluoran, 2-(3-trifluoromethylanilino)-6-diethylaminofluoran, 2-(3-trifluoromethylanilino)-6-di-n-pentylaminofluoran, 2-dibenzylamino-6-diethylaminofluoran, 2-(N-methylanilino)-6-(N-ethyl-Np-tolylamino)fluoran, 1,3-dimethyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methoxy-6-diethylaminofluoran, 2-anilino-3-methyl-6-di-n-butylaminofluoran, 2-anilino-3-methoxy-6-di-n-butylaminofluoran, 2-xylidino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-(N-ethyl-Np-tolylamino)fluoran, 6-diethylamino-1,2-benzofluoran, 6-(N-ethyl-N-isobutylamino)-1,2-benzofluoran, 6-(N-ethyl-N-isopentylamino)-1,2-benzofluoran, 2-(3-methoxy-4-dodecoxystyryl)quinoline, 2-diethylamino-8-diethylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 2-di-n-butylamino-8-di-n-butylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 2-di-n-butylamino-8-diethylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 2-di-n-butylamino-8-(N-ethyl-N-isoamylamino)-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 2-di-n-butylamino-8-di-n-pentylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 4,5,6,7-tetrachloro-3-(4-dimethylamino-2-methoxyphenyl)-3-(1-n-butyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 4,5,6,7-tetrachloro-3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 4,5,6,7-tetrachloro-3-(4-diethylamino-2-ethoxyphenyl)-3-(1-n-pentyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 4,5,6,7-tetrachloro-3-(4-diethylamino-2-methylphenyl)-3-(1-ethyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 3',6'-bis[phenyl(2-methylphenyl)amino]spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one, 3',6'-bis[phenyl(3-methylphenyl)amino]spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one, 3',6'-bis[phenyl(3-ethylphenyl)amino]spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one, 2,6-bis(2′-ethyloxyphenyl)-4-(4′-dimethylaminophenyl)pyridine, 2,6-bis(2′,4′-diethyloxyphenyl)-4-(4′-dimethylaminophenyl)pyridine, 2-(4′-dimethylaminophenyl)-4-methoxyquinazoline, 4,4'-Ethylenedioxy-bis[2-(4-diethylaminophenyl)quinazoline]

[0014] In addition, fluorans may be compounds having a substituent on the phenyl group forming the xanthene ring, or may be compounds that have a substituent on the phenyl group forming the xanthene ring and also have a substituent (for example, an alkyl group such as a methyl group, or a halogen atom such as a chlorine atom) on the phenyl group forming the lactone ring, and that exhibit a blue or black color.

[0015] Component (b), ie, the electron accepting compound, is a compound that accepts electrons from component (a) and functions as a developer for component (a). Examples of the electron-accepting compound include compounds selected from the group of compounds having an active proton, the group of pseudo-acidic compounds (compounds that are not acids but act as acids in the reversible thermochromic composition to cause component (A) to develop color), and the group of compounds having an electron vacancy. Among the above-mentioned component (B), compounds selected from the group of compounds having an active proton are preferred.

[0016] Examples of compounds having an active proton include compounds having a phenolic hydroxyl group and derivatives thereof, carboxylic acids and derivatives thereof, acidic phosphate esters and derivatives thereof, azole compounds and derivatives thereof, 1,2,3-triazole and derivatives thereof, cyclic carbosulfimides, halohydrins having 2 to 5 carbon atoms, sulfonic acids and derivatives thereof, and inorganic acids. Preferred examples of carboxylic acids and derivatives thereof include aromatic carboxylic acids and derivatives thereof, and aliphatic carboxylic acids having 2 to 5 carbon atoms and derivatives thereof. Examples of the pseudo-acidic compounds include metal salts of compounds having a phenolic hydroxyl group, metal salts of carboxylic acids, metal salts of acidic phosphate esters, metal salts of sulfonic acids, aromatic carboxylic acid anhydrides, aliphatic carboxylic acid anhydrides, mixed anhydrides of aromatic carboxylic acids and sulfonic acids, cycloolefin dicarboxylic acid anhydrides, urea and its derivatives, thiourea and its derivatives, guanidine and its derivatives, and halogenated alcohols. Compounds having electron vacancies include borates, borate esters, and inorganic salts.

[0017] Among the above-mentioned components (ii), compounds having a phenolic hydroxyl group are preferred because they can more effectively exhibit thermochromic properties. Compounds having a phenolic hydroxyl group include a wide range of compounds, from monophenol compounds to polyphenol compounds, and further include bisphenol compounds, trisphenol compounds, phenol-aldehyde condensation resins, etc. Compounds having a phenolic hydroxyl group preferably have at least two benzene rings. In addition, compounds having a phenolic hydroxyl group may have a substituent such as an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carboxyl group and its ester or amide group, or a halogen atom.

[0018] Examples of metals contained in metal salts of compounds having a phenolic hydroxyl group include sodium, potassium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, and molybdenum.

[0019] Examples of compounds of component (b) are given below. Examples of compounds having one phenolic hydroxyl group include: phenol, o-cresol, m-cresol, p-cresol, 4-ethylphenol, 4-n-propylphenol, 4-n-butylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, 4-n-pentylphenol, 4-tert-pentylphenol, 4-n-octylphenol, 4-tert-octylphenol, 4-n-nonylphenol, 4-n-dodecylphenol, 3-n-pentadecylphenol, 4-n-stearylphenol, 1-(4-hydroxyphenyl)decan-1-one, 4-chlorophenol, 4-bromophenol, 4-trifluoromethylphenol, 4-methylthiophenol, 4-nitrophenol, 2-phenylphenol, 4-phenylphenol, 2-benzylphenol, 2-benzyl-4-chlorophenol, 4-cumylphenol, 4-hydroxybenzophenone, 4-chloro-4′-hydroxybenzophenone, 4-fluoro-4′-hydroxybenzophenone, 4-cyclohexylphenol, 2-hydroxybenzyl alcohol, 3-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, 4-(2-hydroxyethyl)phenol, 3-methoxyphenol, 4-ethoxyphenol, 4-n-propoxyphenol, 4-n-butoxyphenol, 4-n-heptyloxyphenol, 4-(2-methoxyethyl)phenol, α-naphthol, β-naphthol, 2,3-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,6-di-tert-butylphenol, 2,4-dichlorophenol, 2,4-difluorophenol, thymol, 3-methyl-4-methylthiophenol, 2-tert-butyl-5-methylphenol, 2,6-bis(hydroxymethyl)-4-methylphenol, 2,3,5-trimethylphenol, 2,6-bis(hydroxymethyl)-4-tert-octylphenol, 6-hydroxy-1,3-benzoxathiol-2-one, 2,4-bis(phenylsulfonyl)phenol, 2,4-bis(phenylsulfonyl)-5-methylphenol, 2,4-bis(4-methylphenylsulfonyl)phenol, 2-phenylphenol, 4-phenylphenol, 2,6-diphenylphenol, 3-benzylbiphenyl-2-ol, 3,5-dibenzylbiphenyl-4-ol, 4-cyano-4′-hydroxybiphenyl, 1-hydroxybenzotriazole, 1-hydroxy-5-methylbenzotriazole, 1-hydroxy-5-chlorobenzotriazole, 1-hydroxy-5-methoxybenzotriazole, 1-hydroxy-4-benzoylaminobenzotriazole, 1-hydroxy-4,5,6,7-tetrachlorobenzotriazole, 1,4-hydroxybenzotriazole, 1-hydroxy-5-nitrobenzotriazole, 1-hydroxy-5-phenylbenzotriazole, 1-hydroxy-5-benzylbenzotriazole, 1-hydroxy-5-ethylbenzotriazole, 1-hydroxy-5-n-octylbenzotriazole, 1-hydroxy-5-n-butylbenzotriazole, n-Butyl 4-hydroxybenzoate, n-Octyl 4-hydroxybenzoate, 4-Hydroxybenzoic acid 2-heptadecafluorooctylethane, benzyl 4-hydroxybenzoate, 4-hydroxybenzoic acid benzyl ester, o-methylbenzyl 4-hydroxybenzoate, m-methylbenzyl 4-hydroxybenzoate, p-methylbenzyl 4-hydroxybenzoate, p-ethylbenzyl 4-hydroxybenzoate, p-propylbenzyl 4-hydroxybenzoate, p-tert-butylbenzyl 4-hydroxybenzoate, phenylethyl 4-hydroxybenzoate, 4-hydroxybenzoic acid-o-methylphenylethyl ester, m-Methylphenylethyl 4-hydroxybenzoate, p-methylphenylethyl 4-hydroxybenzoate, p-Ethylphenylethyl 4-hydroxybenzoate, p-propylphenylethyl 4-hydroxybenzoate, p-tert-butylphenylethyl 4-hydroxybenzoate Examples include:

[0020] Examples of compounds having two phenolic hydroxyl groups include: Resorcinol, 2-methylresorcinol, 4-n-hexylresorcinol, 4-n-octylresorcinol, 4-tert-octylresorcinol, 4-benzoylresorcinol, 4-nitroresorcinol, β-methyl resorcylate, β-benzyl resorcylate, 2-chloro-4-pentanoylresorcinol, 6-chloro-4-pentanoylresorcinol, 2-chloro-4-hexanoylresorcinol, 6-chloro-4-hexanoylresorcinol, 2-chloro-4-propanoylresorcinol, 6-chloro-4-propanoylresorcinol, 2,6-dichloro-4-propanoylresorcinol, 6-fluoro-4-propanoylresorcinol, 2-chloro-4-phenylacetylresorcinol, 6-chloro-4-phenylacetylresorcinol, 2-chloro-4-β-phenylpropanoylresorcinol, 6-chloro-4-β-phenylpropanoylresorcinol, 2-chloro-4-phenoxyacetylresorcinol, 6-chloro-4-phenoxyacetylresorcinol, 4-benzoyl-2-chlororesorcinol, 6-chloro-4-m-methylbenzoylresorcinol, 4-[1',3',4',9'a-tetrahydro-6'-hydroxyspiro(cyclohexane-1,9'-[9H]-xanthene)-4'a-[2H]-yl]-1,3-benzenediol, hydroquinone, methylhydroquinone, trimethylhydroquinone, Catechol, 4-tert-butylcatechol, 1,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,4-dihydroxybenzophenone, 4,4′-dihydroxybenzophenone, 2,4-dihydroxy-2′-methylbenzophenone, 2,4-dihydroxy-3′-methylbenzophenone, 2,4-dihydroxy-4′-methylbenzophenone, 2,4-dihydroxy-4′-ethylbenzophenone, 2,4-dihydroxy-4′-n-propylbenzophenone, 2,4-dihydroxy-4′-isopropylbenzophenone, 2,4-dihydroxy-4′-n-butylbenzophenone, 2,4-dihydroxy-4′-isobutylbenzophenone, 2,4-dihydroxy-4′-tert-butylbenzophenone, 2,4-dihydroxy-4′-n-pentylbenzophenone, 2,4-dihydroxy-4′-n-hexylbenzophenone, 2,4-dihydroxy-4′-n-heptylbenzophenone, 2,4-dihydroxy-4′-n-octylbenzophenone, 2,4-dihydroxy-4′-n-decylbenzophenone, 2,4-dihydroxy-2′,3′-dimethylbenzophenone, 2,4-dihydroxy-2′,4′-dimethylbenzophenone, 2,4-dihydroxy-2′,5′-dimethylbenzophenone, 2,4-dihydroxy-2′,6′-dimethylbenzophenone, 2,4-dihydroxy-3′,4′-dimethylbenzophenone, 2,4-dihydroxy-3′,5′-dimethylbenzophenone, 2,4-dihydroxy-2′,4′,6′-trimethylbenzophenone, 2,4-dihydroxy-2′-methoxybenzophenone, 2,4-dihydroxy-3′-methoxybenzophenone, 2,4-dihydroxy-4′-methoxybenzophenone, 2,4-dihydroxy-2′-ethoxybenzophenone, 2,4-dihydroxy-4′-ethoxybenzophenone, 2,4-dihydroxy-4′-n-propoxybenzophenone, 2,4-dihydroxy-4′-isopropoxybenzophenone, 2,4-dihydroxy-4′-n-butoxybenzophenone, 2,4-dihydroxy-4′-isobutoxybenzophenone, 2,4-dihydroxy-4′-n-pentyloxybenzophenone, 2,4-dihydroxy-4′-n-hexyloxybenzophenone, 2,4-dihydroxy-4′-n-heptyloxybenzophenone, 2,4-dihydroxy-4′-n-octyloxybenzophenone, 2,4-dihydroxy-4′-n-nonyloxybenzophenone, 2,4-dihydroxy-2′,3′-dimethoxybenzophenone, 2,4-dihydroxy-2′,4′-dimethoxybenzophenone, 2,4-dihydroxy-2′,5′-dimethoxybenzophenone, 2,4-dihydroxy-2′,6′-dimethoxybenzophenone, 2,4-dihydroxy-3′,4′-dimethoxybenzophenone, 2,4-dihydroxy-3′,5′-dimethoxybenzophenone, 2,4-dihydroxy-3′,4′-diethoxybenzophenone, 2,4-dihydroxy-2′,3′,4′-trimethoxybenzophenone, 2,4-dihydroxy-2′,3′,6′-trimethoxybenzophenone, 2,4-dihydroxy-3′,4′,5′-trimethoxybenzophenone, 2,4-Dihydroxy-3',4',5'-triethoxybenzophenone Examples include:

[0021] Further, examples of bisphenol compounds include: 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl) n-butane, 1,1-bis(4-hydroxyphenyl) n-pentane, 1,1-bis(4-hydroxyphenyl) n-hexane, 1,1-bis(4-hydroxyphenyl) n-heptane, 1,1-bis(4-hydroxyphenyl) n-octane, 1,1-bis(4-hydroxyphenyl)n-nonane, 1,1-bis(4-hydroxyphenyl) n-decane, 1,1-bis(4-hydroxy-3-methylphenyl)decane, 1,1-bis(4-hydroxyphenyl) n-dodecane, 1,1-bis(4-hydroxyphenyl)-2-methylpropane, 1,1-bis(4-hydroxyphenyl)-3-methylbutane, 1,1-bis(4-hydroxyphenyl)-3-methylpentane, 1,1-bis(4-hydroxyphenyl)-2,3-dimethylpentane, 1,1-bis(4-hydroxyphenyl)-2-ethylbutane, 1,1-bis(4-hydroxyphenyl)-2-ethylhexane, 1,1-bis(4-hydroxyphenyl)-3,7-dimethyloctane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4-hydroxy-3-methyl)cyclohexane, diphenolic acid, 1-phenyl-1,1-bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)n-butane, 2,2-bis(4-hydroxyphenyl) n-pentane, 2,2-bis(4-hydroxyphenyl)n-hexane, 2,2-bis(4-hydroxyphenyl) n-heptane, 2,2-bis(4-hydroxyphenyl) n-octane, 2,2-bis(4-hydroxyphenyl)n-nonane, 2,2-bis(4-hydroxyphenyl) n-decane, 2,2-bis(4-hydroxyphenyl) n-dodecane, 2,2-bis(4-hydroxyphenyl)-6,10,14-trimethylpentadecane, 1-phenyl-1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)methylpropionate, 2,2-bis(4-hydroxyphenyl)butylpropionate, 2,2-bis(4-hydroxy-3-methylphenyl)methylpropionate, 2,2-bis(4-hydroxyphenyl)ethyl propionate, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 2,2-bis(4-hydroxyphenyl)-4-methylhexane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)butane, 2,2-bis(4-hydroxy-3-isopropylphenyl)propane, 2,2-bis(3-sec-butylphenyl-4-hydroxy)propane, 2,2-bis(4-hydroxy-3-phenylphenyl)propane, 2,2-bis(3-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-fluoro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)propane, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 3,3-bis(4-hydroxyphenyl)oxindole, 3,3-bis(4-hydroxy-3-methylphenyl)oxindole, bis(2-hydroxyphenyl)methane, bis(2-hydroxy-5-methylphenyl)methane, bis(2-hydroxy-3-hydroxymethyl-5-methyl)methane, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bis(2-methylphenol), 1,1-bis(4-hydroxy-3-phenylphenyl)cyclohexane, 3,3-ethyleneoxydiphenol, 1,4-bis(4-hydroxybenzoate)-3-methylbenzene, 4,4"-dihydroxy-3"-methyl-p-terphenyl, 4,4″-dihydroxy-3″-isopropyl-p-terphenyl, 2,2-dimethyl-1,3-bis(4-hydroxybenzoyloxy)propane, 2,2′-biphenol, 4,4′″-dihydroxy-p-quaterphenyl, 4,4-dihydroxydiphenyl ether, Bis(4-hydroxyphenylthioethyl) ether bis(4-hydroxyphenyl) sulfone, 4-benzyloxy-4′-hydroxydiphenyl sulfone, 4-(4-methylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-ethylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-n-propylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-isopropylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-n-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-isobutylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-sec-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-tert-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-methylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-ethylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-n-propylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-isopropylbenzyloxy)-4′-dihydroxyphenyl sulfone, 4-(3-n-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-isobutylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-sec-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-tert-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-methylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-ethylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-n-propylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-isopropylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-n-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-isobutylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-sec-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-tert-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 2,4′-dihydroxydiphenyl sulfone, 3,4′-dihydroxydiphenyl sulfone, 4-hydroxydiphenyl sulfone, 4-methyl-4'-hydroxyphenyl sulfone, 4-ethyl-4′-hydroxydiphenyl sulfone, 4-n-propyl-4′-hydroxydiphenyl sulfone, 4-isopropyl-4′-hydroxydiphenyl sulfone, 4-chloro-4′-hydroxydiphenyl sulfone, 4-fluoro-4′-hydroxydiphenyl sulfone, 4-chloro-2-methyl-4′-hydroxydiphenyl sulfone, 4-methoxy-4′-hydroxydiphenyl sulfone, 4-ethoxy-4′-hydroxydiphenyl sulfone, 4-n-propoxy-4′-hydroxydiphenyl sulfone, 4-isopropoxy-4′-hydroxydiphenyl sulfone, 4-n-butoxy-4′-hydroxydiphenyl sulfone, 4-isobutoxy-4′-hydroxydiphenyl sulfone, 4-sec-butoxy-4′-hydroxydiphenyl sulfone, 4-tert-butoxy-4′-hydroxydiphenyl sulfone, 4-n-pentyloxy-4′-hydroxydiphenyl sulfone, 4-isopentyloxy-4′-hydroxydiphenyl sulfone, 4-(1-propenyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-propenyloxy)-4′-hydroxydiphenyl sulfone, 4-benzyloxy-4′-hydroxydiphenyl sulfone, 4-(β-phenoxyethoxy)-4′-hydroxydiphenyl sulfone, 4-(β-phenoxypropoxyl)-4′-hydroxydiphenyl sulfone, bis(2-allyl-4-hydroxydiphenyl) sulfone, bis[4-hydroxy-3-(2-propenyl)phenyl]sulfone, bis(3,5-dibromo-4-hydroxyphenyl) sulfone, bis(3,5-dichloro-4-hydroxyphenyl) sulfone, bis(3-phenyl-4-hydroxyphenyl) sulfone, bis(4-hydroxy-3-n-propylphenyl) sulfone, bis(4-hydroxy-3-methylphenyl) sulfone, 3,4-dihydroxydiphenyl sulfone, 3',4'-dihydroxy-4-methyldiphenyl sulfone, 3,4,4′-trihydroxydiphenyl sulfone, bis(3,4-dihydroxyphenyl) sulfone, 2,3,4-trihydroxydiphenyl sulfone, 4-isopropoxy-4′-hydroxydiphenyl sulfone, 4-n-propoxy-4′-hydroxydiphenyl sulfone, 4-allyloxy-4′-hydroxydiphenyl sulfone, 4-benzyloxy-4′-hydroxydiphenyl sulfone, 4-(2-propenyloxy)-4′-hydroxydiphenyl sulfone, 3-benzyl-4-benzyloxy-4′-hydroxydiphenyl sulfone, 3-phenethyl-4-phenethyloxy-4′-hydroxydiphenyl sulfone, 3-methylbenzyl-4-methylbenzyloxy-4′-hydroxydiphenyl sulfone, 4-benzyloxy-3′-benzyl-4′-hydroxydiphenyl sulfone, 4-phenethyloxy-3′-phenethyl-4′-hydroxydiphenyl sulfone, 4-methylbenzyloxy-3′-methylbenzyl-4′-hydroxydiphenyl sulfone, α,α′-bis{4-(p-hydroxyphenylsulfone)phenoxy}-p-xylene, 4,4′-{oxybis(ethylene oxide-p-phenylene sulfonyl)}diphenol, Bis(4-hydroxyphenyl) sulfide, bis(4-hydroxy-3-methylphenyl) sulfide, bis(3,5-dimethyl-4-hydroxyphenyl) sulfide, bis(3-ethyl-4-hydroxyphenyl) sulfide, bis(3,5-diethyl-4-hydroxyphenyl) sulfide, bis(4-hydroxy-3-n-propylphenyl) sulfide, bis(3,5-di-n-propyl-4-hydroxyphenyl) sulfide, bis(3-tert-butyl-4-hydroxyphenyl) sulfide, bis(3,5-di-tert-butyl-4-hydroxyphenyl) sulfide, bis(4-hydroxy-3-n-pentylphenyl) sulfide, bis(3-n-hexyl-4-hydroxyphenyl) sulfide, bis(3-n-heptyl-4-hydroxyphenyl) sulfide, bis(5-tert-octyl-2-hydroxyphenyl) sulfide, bis(2-hydroxy-3-tert-octylphenyl) sulfide, bis(2-hydroxy-5-n-octyl-phenyl) sulfide, bis(5-chloro-2-hydroxyphenyl) sulfide, bis(3-cyclohexyl-4-hydroxyphenyl) sulfide, bis(4-hydroxyphenylthioethoxy)methane, 1,5-(4-hydroxyphenylthio)-3-oxypentane, 1,8-bis(4-hydroxyphenylthio)-3,6-dioxaoctane Examples include:

[0022] Examples of compounds having three phenolic hydroxyl groups include pyrogallol, phloroglucinol, phloroglucinolcarboxylic acid, gallic acid, octyl gallate, and dodecyl gallate.

[0023] Further examples of trisphenol compounds include: 4,4′,4″-methylidynetrisphenol, 4,4′,4″-methylidynetris(2-methylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2,3,5-trimethylphenol), 4,4'-[(4-hydroxyphenyl)methylene]bis(2-methylphenol), 4,4'-[(4-hydroxyphenyl)methylene]bis(2,6-dimethylphenol), 4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bisphenol, 4,4'-[(4-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 4,4′,4″-ethylidynetrisphenol, 4,4′,4″-ethylidinetris(2-methylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenol, 2,4-bis[(2-hydroxy-5-methylphenyl)methyl]-6-cyclohexylphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}methylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}propylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}butylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}pentylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}hexylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}heptylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}isobutylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}neopentylidene]bisphenol, 2,2'-[1-{4-[1-(2-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol, 3,3′-[1-{4-[1-(3-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol, 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-fluorophenol), 4,4'-[1-{4-[1-(3-chloro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-chlorophenol), 4,4'-[1-{4-[1-(3-bromo-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-bromophenol), 4,4'-[1-{4-[1-(4-hydroxy-3-methylphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-methylphenol), 4,4'-[1-{4-[1-(3-ethyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-ethylphenol), 4,4'-[1-{4-[1-(3-tert-butyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-tert-butylphenol), 4,4'-[1-{4-[1-(4-hydroxy-3-trifluoromethylphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-trifluoromethylphenol), 1,1-bis(4-hydroxyphenyl)-4-(4-hydroxy-α-ethyl)benzylcyclohexane, 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bisphenol, 4,4'-[(3-hydroxyphenyl)methylene]bis(2,6-dimethylphenol), 2,2'-[(4-hydroxyphenyl)methylene]bis(3,5-dimethylphenol), 4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2,6-dimethylphenol), 2,2'-[(2-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 4,4'-[(3-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol), 4,4'-[(4-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol), 4,4'-[(3-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[(4-hydroxyphenyl-3-methoxy)methylene]bis(2-cyclohexyl-5-methylphenol), 1,1-bis(4-hydroxyphenyl)-4-hydroxyphenylcyclohexane, 4,4'-[3-(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-phenyl)propylidene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2-methylphenol), 2,4′,4″-methylidynetrisphenol, 4,4'-[(2-hydroxyphenyl)methylene]bis(3-methylphenol), 4,4'-[4-(4-hydroxyphenyl)-sec-butylidene]bis(4-hydroxyphenol), 2,2'-[(3-hydroxyphenyl)methylene]bis(3,5-dimethylphenol), 4,4'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2,5-dimethylphenol), 4,4'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2,6-dimethylphenol), 2,2'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(3,5-dimethylphenol), 2,2'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(3,5-dimethylphenol), 2,2'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(3,5-dimethylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2-isopropylphenol), 4,4'-[(3-hydroxyphenyl)methylene]bis(2-isopropylphenol), 4,4'-[(4-hydroxyphenyl)methylene]bis(2-isopropylphenol), 2,2'-[(3-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 2,2'-[(4-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 2,2'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(3,5-dimethylphenol), 1,1-bis(4-hydroxy-3-methylphenyl)-4-(4-hydroxyphenyl)cyclohexane, 4,4'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2-isopropylphenol), 4,4'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(2-isopropylphenol), 4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2-isopropylphenol), 2,2'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol), 2,2'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol), 2,2'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol), 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-isopropylphenol), 2,2'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol), 1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)cyclohexane, 4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2-tert-butyl-5-methylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2-cyclohexylphenol), 4,4'-[(3-hydroxyphenyl)methylene]bis(2-cyclohexylphenol), 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-tert-butyl-6-methylphenol), 4,4'-[(3-methoxy-2-hydroxyphenyl)methylene]bis(2-cyclohexylphenol), 4,4'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(2-cyclohexylphenol), 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-tert-butylphenol), 4,4'-[1-{4-[1-(3,5-dimethyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2,6-dimethylphenol), 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[(3-cyclohexyl-4-hydroxyphenyl)ethylidene]bis(2-cyclohexylphenol), 4,4'-[(5-cyclohexyl-4-hydroxy-2-methoxyphenyl)ethylidene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[1-{4-[1-(3-cyclohexyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-cyclohexylphenol), 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol, 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-methylphenol), 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2,6-dimethylphenol), 2,6-bis[(5-fluoro-2-hydroxyphenyl)methyl]-4-methylphenol, 2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-4-methylphenol, 2,6-bis[(4-hydroxyphenyl)methyl]-4-methylphenol, 2,6-bis[(4-hydroxyphenyl)methyl]-4-ethylphenol, 2,4-bis[(4-hydroxy-3-methylphenyl)methyl]-6-methylphenol, 2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-methylphenol, 2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-ethylphenol, 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-ethylphenol, 2,6-bis[(3,5-dimethyl-2-hydroxyphenyl)methyl]-4-methylphenol, 2,6-bis[(2,4-dimethyl-6-hydroxyphenyl)methyl]-4-methylphenol, 2,4-bis[(4-hydroxyphenyl)methyl]-6-cyclohexylphenol, 2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-3,4-dimethylphenol, 2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-4-ethylphenol, 2,6-bis[(4-hydroxy-2,3,6-trimethylphenyl)methyl]-4-methylphenol, 2,4-bis[(4-hydroxy-3-methylphenyl)methyl]-6-cyclohexylphenol, 2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-cyclohexylphenol, 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-cyclohexylphenol, 2,6-bis[(4-hydroxy-2,3,5-trimethylphenyl)methyl]-4-ethylphenol, 2,4-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-6-cyclohexylphenol, 4,4′,4″-methylidynetris(2,6-dimethylphenol), α-(4-hydroxy-3-methylphenyl)-α,α′-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, α′-(4-hydroxy-3-methylphenyl)-α,α-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, α,α-bis(4-hydroxy-3-methylphenyl)-α′-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, α,α′-bis(4-hydroxy-3-methylphenyl)-α-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, 1,1-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)-1-methylpropyl]cyclohexane, 2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-4-ethylphenol, 1,1′-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane, 1,1′-bis(4-hydroxy-3-methylphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane, 1,1′-bis(3,5-dimethyl-4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane, 1-(4-hydroxyphenyl)-1-[4,4-bis(4-hydroxyphenyl)cyclohexyl]-4-isopropylcyclohexane, 4,4'-[3-(2,5-dimethyl-4-hydroxyphenyl)butylene]bis(2,5-dimethylphenol), 1,3,5-tri(4-hydroxy-3-phenylphenyl)adamantane, 1,3,5-tri(3-cyclohexyl-4-hydroxyphenyl)adamantane, 2,4-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-6-cyclohexylphenol, 2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-4-cyclohexylphenol, 2,4-bis[(3-cyclohexyl-4-hydroxyphenyl)methyl]-6-methylphenol, 2,4-bis[(4-hydroxy-2,3,5-trimethylphenyl)methyl]-6-cyclohexylphenol, 2,6-bis[(5-fluoro-2-hydroxyphenyl)methyl]-4-fluorophenol, 2,6-bis[(3-fluoro-4-hydroxyphenyl)methyl]-4-fluorophenol, 2,4-bis[(3-fluoro-4-hydroxyphenyl)methyl]-6-methylphenol, 4,4'-[3-(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-biphenylpropylidene]bis(5-cyclohexyl-2-methylphenol), 4,4'-[3-(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropylidene]bis(2,5-dimethylphenol), 2,4-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-6-methylphenol, 1,1,2-tris(4-hydroxyphenyl)ethane, 1,1,3-tris(4-hydroxyphenyl)propane, 1,1,4-tris(4-hydroxyphenyl)butane, 1,2,2-tris(4-hydroxyphenyl)propane, 1,2,2-tris(4-hydroxyphenyl)butane, 1,2,2-tris(4-hydroxyphenyl)pentane, 1,2,2-tris(4-hydroxyphenyl)hexane, 1,2,2-tris(4-hydroxyphenyl)heptane, 1,2,2-tris(4-hydroxyphenyl)octane, 1,2,2-tris(4-hydroxyphenyl)-3-methylbutane 1,2,2-tris(4-hydroxyphenyl)-3,3-dimethylbutane, 1,2,2-tris(4-hydroxyphenyl)-4,4-dimethylpentane, 1,3,3-tris(4-hydroxyphenyl)butane, 1,3,3-tris(4-hydroxyphenyl)pentane, 1,3,3-tris(4-hydroxyphenyl)hexane, 1,3,3-tris(4-hydroxyphenyl)heptane, 1,3,3-tris(4-hydroxyphenyl)octane, 1,3,3-tris(4-hydroxyphenyl)nonane, 1,4,4-tris(4-hydroxyphenyl)pentane, 1,4,4-tris(4-hydroxyphenyl)hexane, 1,4,4-tris(4-hydroxyphenyl)heptane, 1,4,4-tris(4-hydroxyphenyl)octane, 1,4,4-tris(4-hydroxyphenyl)nonane, 1,4,4-tris(4-hydroxyphenyl)decane, 1,2,2-tris(2-hydroxyphenyl)propane, 1,1,2-tris(3-hydroxyphenyl)propane, 1-(4-hydroxyphenyl)-2,2-bis(2-hydroxyphenyl)propane, 1,2,2-tris(3-fluoro-4-hydroxyphenyl)propane, 1,2,2-tris(3-chloro-4-hydroxyphenyl)propane, 1,2,2-tris(3-bromo-4-hydroxyphenyl)propane, 2,2-bis(3-ethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane, 2,2-bis(3-tert-butyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane, 2,2-bis(2-hydroxy-3-biphenylyl)-1-(4-hydroxyphenyl)propane, 2,2-bis(3-trifluoromethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane, 2-(3-methyl-4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)propane, 1-(3-methyl-4-hydroxyphenyl)-2,2-bis(4-hydroxyphenyl)propane, 3-(3-methyl-4-hydroxyphenyl)-1,3-bis(4-hydroxyphenyl)butane, 1-(3-methyl-4-hydroxyphenyl)-3,3-bis(4-hydroxyphenyl)butane, 4-(3-methyl-4-hydroxyphenyl)-1,4-bis(4-hydroxyphenyl)pentane, 1-(3-methyl-4-hydroxyphenyl)-4,4-bis(4-hydroxyphenyl)pentane, 1,2-bis(3-methyl-4-hydroxyphenyl)-2-(4-hydroxyphenyl)propane, 3,3-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)butane, 1,3-bis(3-methyl-4-hydroxyphenyl)-3-(4-hydroxyphenyl)butane, 4,4-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)pentane, 1,4-bis(3-methyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)pentane, 1,1,2-tris(3-methyl-4-hydroxyphenyl)ethane, 1,2,2-tris(3-methyl-4-hydroxyphenyl)propane, 1,1,3-tris(3-methyl-4-hydroxyphenyl)propane, 1,3,3-tris(3-methyl-4-hydroxyphenyl)butane, 1,1,4-tris(3-methyl-4-hydroxyphenyl)butane, 1,4,4-tris(3-methyl-4-hydroxyphenyl)pentane, 4,4'-[4-(4-hydroxyphenyl)-sec-butylidene]bis(2-methylphenol) Examples include:

[0024] Examples of compounds having four or more phenolic hydroxyl groups include: Bis[2-hydroxy-3-(2-hydroxy-5-methylbenzyl)-5-methylphenyl]methane, 4,6-bis[(4-hydroxyphenyl)methyl]-1,3-benzenediol, 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2,6-dimethylphenol), 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-methylphenol), 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2,3,6-trimethylphenol), 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 4,4′,4″,4′″-(1,1,2,2-ethanetetrayl)tetrakis(2-methylphenol), 4,4′,4″,4′″-(1,1,2,2-ethanetetrayl)tetrakis(2,6-dimethylphenol), 4,4',4"4'"-(1,4-phenylene)bis(methylidyne)tetrakis(2,6-dimethylphenol), 2,2-bis[4,4-bis(4-hydroxy-3-methylphenyl)cyclohexyl]propane, 2,2'-[(3,4-dihydroxyphenyl)methylene]bis(3,5-dimethylphenol), 4,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-1,3-benzenediol, 2,2'-[(3,4-dihydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexylphenol), Bis[4-hydroxy-3-(2-hydroxybenzyl)-5-methylphenyl]methane, Bis[4-hydroxy-3-(3-hydroxybenzyl)-5-methylphenyl]methane, Bis[4-hydroxy-3-(4-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(3-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(4-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(3-hydroxy-4-methylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(4-hydroxy-3-methylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(3-hydroxy-2-methylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2-hydroxy-3-methylbenzyl)-5-methylphenyl]methane, α,α′,α″,α′″-tetrakis(4-hydroxyphenyl)-p-xylene, Bis[2-hydroxy-3-(4-hydroxy-2,3,5-trimethylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2,5-dimethyl-3-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2,5-dimethyl-4-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2,5-dimethyl-5-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(3,5-dimethyl-4-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2-hydroxy-3,4,6-trimethylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(4-hydroxy-2,3,6-trimethylbenzyl)-5-methylphenyl]methane, 4,4,4′,4′-tetrakis(4-hydroxyphenyl)bicyclohexyl, Bis[4-hydroxy-3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)-5-methylphenyl]methane, 4,4,4′,4′-tetrakis(4-hydroxy-3-methylphenyl)bicyclohexyl, 4,6-bis(3,5-dimethyl-4-hydroxyphenyl)-1,2-benzenediol, 4,4,4′,4′-tetrakis(3,5-dimethyl-4-hydroxyphenyl)bicyclohexyl, 1,1-bis[5-cyclohexyl-4-hydroxy-3-(2-hydroxy-5-methylbenzyl)phenyl]cyclohexane, 1,1-bis[5-cyclohexyl-4-hydroxy-3-(3,5-dimethyl-4-hydroxybenzyl)phenyl]cyclohexane, 1,1-bis[5-cyclohexyl-4-hydroxy-3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)phenyl]cyclohexane, 4,6-bis[1-(4-hydroxyphenyl)ethyl]-1,3-benzenediol, 2,2-bis[4-hydroxy-3-(4-hydroxy-3-methylbenzyl)-5-methylphenyl]propane, 2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)benzyl]-4-[α-methyl-(3,5-dimethyl-4-hydroxyphenyl)benzyl]phenol, 4,4,4',4'-tetrakis(3-isopropyl-4-hydroxyphenyl)bicyclohexyl, 4,4'-bis[(3,4-dihydroxyphenyl)methylene]bis(2-isopropylphenol), 2,2'-bis[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane, 2,4,6-tris(4-hydroxybenzyl)-1,3-benzenediol, 4,6-bis(3,5-dimethyl-4-hydroxybenzyl)-1,2,3-benzenetriol, 3,3'-[(2-hydroxyphenyl)methylene]bis(5-methyl-1,2-benzenediol), 2,6-bis(2,4-dihydroxybenzyl)-4-ethylphenol, 2,4-bis(2,4-dihydroxybenzyl)-6-cyclohexylphenol, 2,6-bis(5-tert-butyl-2,3-dihydroxybenzyl)-4-methylphenol, 2,4,6-tris(3,5-dimethyl-4-hydroxybenzyl)-1,2-benzenediol, 2,4,6-tris(3,5-dimethyl-2-hydroxybenzyl)-1,2-benzenediol, 2,6-bis(2,4-dihydroxybenzyl)-3,4-dimethylphenol, 2,6-bis[3-(2-hydroxy-5-methylbenzyl)-2,5-dimethyl-4-hydroxybenzyl]-3,4-dimethylphenol, 4,6-bis(α-methyl-4-hydroxybenzyl)-1,2,3-benzenetriol, 4,4'-[1-{4-[1-(3,5-bis(4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxybenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-3-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-3-methylbenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3,5-dimethyl-4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3,5-dimethyl-4-hydroxybenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2,3,6-trimethylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-2,3,6-trimethylbenzyl)phenol], Bis[5-(2,4-dihydroxybenzyl)-4-hydroxy-3-methylphenyl]methane, Bis[3-(2,4-dihydroxybenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane, Bis[3-(2,4-dihydroxy-3-methylbenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane, Bis[5-(4-hydroxybenzyl)-2,3,4-trihydroxyphenyl]methane, 1,1-bis[5-(4-hydroxybenzoyl)-2,3,4-trihydroxyphenyl]ethane, 3,3′,5,5′-tetrakis(4-hydroxybenzyl)-4,4′-dihydroxybiphenyl, 3,3′,5,5′-tetrakis(4-hydroxy-3-methylbenzyl)-4,4′-dihydroxybiphenyl, 3,3′,5,5′-tetrakis(2-hydroxy-5-methylbenzyl)-4,4′-dihydroxybiphenyl, 3,3′,5,5′-tetrakis(3,5-dimethyl-4-hydroxybenzyl)-4,4′-dihydroxybiphenyl, Bis[3-(α,α-bis(4-hydroxy-3-methylphenyl)methyl-4-hydroxyphenyl]methane, Bis[3,5-bis(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane, 4,4',4"-ethylidinetris{[2-(2-hydroxy-5-methyl)benzyl]-6-methylphenol}, 2,2-bis[3,5-bis(2-hydroxy-5-methylphenylmethyl)phenyl]propane, Bis[3-(α,α-bis(2,5-dimethyl-4-hydroxyphenyl)methyl-4-hydroxyphenyl]methane, Bis[5-(3,5-dimethyl-4-hydroxybenzyl)-2,3,4-trihydroxyphenyl]methane, Bis[3-(2,3,4-trihydroxybenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane, 1,1-bis[3-(2,3,4-trihydroxybenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane, 1,8,15,22-tetranonyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane, 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-2-methylbenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(2-hydroxy-5-methylbenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3-ethyl-4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3-ethyl-4-hydroxybenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3,5-dimethyl-2-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3,5-dimethyl-2-hydroxyphenyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-3-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-3-isopropylphenyl)phenol], Bis[3-(α,α-bis(3,5-dimethyl-4-hydroxyphenyl)methyl-4-hydroxyphenyl]methane, Bis[3-(α,α-bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)methyl-4-hydroxyphenyl]methane, 4,4'-[4-hydroxy-3,5-bis(2-hydroxybenzyl)methylene]bis[2,6-bis(2-hydroxybenzyl)]phenol, 4,4'-[4-hydroxy-3,5-bis(4-hydroxybenzyl)methylene]bis[2,6-bis(4-hydroxybenzyl)]phenol, 4,4',4"-Ethylidinetris[2,6-bis(2-hydroxybenzyl)phenol], 4,4',4"-Ethylidinetris[2,6-bis(4-hydroxybenzyl)phenol], 2,2-bis[3,5-bis(4-hydroxy-3-methylbenzyl)-4-hydroxyphenyl]propane, 1,8,15,22-tetraethyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane, α,α′,α″,α′″-tetrakis(3,5-dimethyl-4-hydroxyphenyl)-1,4-dimethylbenzene, 4,4'-[1-{4-[1-(3,5-bis(2-hydroxy-5-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(2-hydroxy-5-isopropylphenyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2,3,5-trimethylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-2,3,5-trimethylphenyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3-sec-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3-sec-butyl-4-hydroxyphenyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3-tert-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3-tert-butyl-4-hydroxyphenyl)phenol], 2,6-bis{[3-(2,4-dihydroxybenzyl)-2,5-dimethyl-4-hydroxy]benzyl}-4-methylphenol, 1,1-bis[5-(2,4-dihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane, 1,1-bis[5-(2,3,4-trihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane, 2,2-bis[4,4',4'',4'''-tetrakis(3,5-dihydroxymethyl-4-hydroxyphenyl)cyclohexyl]propane Examples include:

[0025] Examples of carboxylic acids and their derivatives include: 3,5-di(α-methylbenzyl)salicylic acid, 4-(2-p-methoxyphenyloxyethoxy)salicylic acid, 4-hydroxyphenylbenzoic acid, 4-chlorobenzoic acid, 4-[2-(p-methoxyphenoxy)ethyloxy]salicylic acid, 4-[3-(p-tolylsulfonyl)propyloxy]salicylic acid, 5-[p-(2-p-methoxyphenoxyethoxy)cumyl]salicylic acid, 4-octyloxycarbonylaminosalicylic acid, 3,5-distyrenated salicylic acid, N-(p-toluenesulfonyl)-glycine, N-(p-toluenesulfonyl)-alanine, N-(p-toluenesulfonyl)-β-alanine, N-phenylaminocarbonyl-glycine, N-phenylaminocarbonyl-valine, N-(m-tolylaminocarbonyl)-phenylalanine, N-(m-tolylaminocarbonyl)-cysteine-S-benzyl, N-(m-tolylaminocarbonyl)-methionine, N-(m-tolylaminocarbonyl)-tyrosine, N-(p-tolylaminocarbonyl)-phenylalanine, N-(p-tolylaminocarbonyl)-cysteine-S-benzyl, N-(p-tolylaminocarbonyl)-methionine, N-(phenylaminocarbonyl)-methionine, N-(p-tolylaminocarbonyl)-tyrosine, 2-O-(phenylaminocarbonyl)-mandelic acid, 2-O-(p-tolylaminocarbonyl)-mandelic acid, 2-O-(m-tolylaminocarbonyl)-mandelic acid, 2-O-(o-tolylaminocarbonyl)-mandelic acid, 2-O-(1-naphthylaminocarbonyl)-mandelic acid, 2-O-(3-isopropenyl-α,α-dimethylbenzylaminocarbonyl)-mandelic acid, 2-O-(benzylaminocarbonyl)-mandelic acid, 2-O-(phenethylaminocarbonyl)-mandelic acid, 2-O-(phenylaminocarbonyl)-lactic acid, 2-O-(p-tolylaminocarbonyl)-lactic acid, 2-O-(m-tolylaminocarbonyl)-lactic acid, 2-O-(o-tolylaminocarbonyl)-lactic acid, 2-O-(1-naphthylaminocarbonyl)-lactic acid, 2-O-(3-isopropenyl-α,α-dimethylbenzylaminocarbonyl)-lactic acid, 2-O-(benzylaminocarbonyl)-lactic acid, 2-O-(phenethylaminocarbonyl)-lactic acid Examples include:

[0026] Examples of acidic phosphate ester compounds include methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, isodecyl acid phosphate, isotridecyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, monobutyl phosphate, dibutyl phosphate, monoisodecyl phosphate, and bis(2-ethylhexyl) phosphate.

[0027] As component (b), a compound having a phenolic hydroxyl group is preferred because it can more effectively exhibit thermochromic properties, but compounds selected from aromatic carboxylic acids, aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphate esters and metal salts thereof, and 1,2,3-triazole and derivatives thereof may also be used.

[0028] The component (c) of the reaction medium that reversibly induces an electron donor-acceptor reaction between the components (a) and (b) in a specific temperature range will now be described. Examples of the component (c) include alcohols, esters, ketones, ethers, and acid amides.

[0029] When a reversible thermochromic composition is encapsulated in microcapsules and used for secondary processing, low molecular weight compounds will evaporate out of the capsules when subjected to high heat treatment, so compounds with 10 or more carbon atoms are preferably used to stably retain the composition within the capsules.

[0030] As the alcohols, aliphatic monohydric saturated alcohols having 10 or more carbon atoms are effective, and examples thereof include decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, heptadecyl alcohol, octadecyl alcohol, eicosyl alcohol, and docosyl alcohol.

[0031] As the esters, esters having 10 or more carbon atoms are effective, and examples thereof include esters obtained from any combination of a monocarboxylic acid having an aliphatic, alicyclic or aromatic ring and a monohydric alcohol having an aliphatic, alicyclic or aromatic ring, esters obtained from any combination of a polycarboxylic acid having an aliphatic, alicyclic or aromatic ring and a monohydric alcohol having an aliphatic, alicyclic or aromatic ring, esters obtained from any combination of a monocarboxylic acid having an aliphatic, alicyclic or aromatic ring and a polyhydric alcohol having an aliphatic, alicyclic or aromatic ring, and Examples of esters include esters obtained from any combination thereof, such as ethyl caprylate, octyl caprylate, stearyl caprylate, myristyl caprate, docosyl caprate, 2-ethylhexyl laurate, n-decyl laurate, 3-methylbutyl myristate, cetyl myristate, isopropyl palmitate, neopentyl palmitate, nonyl palmitate, cyclohexyl palmitate, n-butyl stearate, 2-methylbutyl stearate, 3,5,5-trimethylhexyl stearate, and stearate. n-Undecyl tearic acid, pentadecyl stearate, stearyl stearate, cyclohexylmethyl stearate, isopropyl behenate, hexyl behenate, lauryl behenate, behenyl behenate, cetyl benzoate, stearyl 4-tert-butylbenzoate, dimyristyl phthalate, distearyl phthalate, dimyristyl oxalate, dicetyl oxalate, dicetyl malonate, dilauryl succinate, dilauryl glutarate, diundecyl adipate, dilauryl azelate, di-(n-nonyl) sebacate ), dineopentyl 1,18-octadecylmethylenedicarboxylate, ethylene glycol dimyristate, propylene glycol dilaurate, propylene glycol distearate, hexylene glycol dipalmitate, 1,5-pentanediol distearate, 1,2,6-hexanetriol trimyristate, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanedimethanol dimyristate, xylene glycol dicaprinate, xylene glycol distearate, and the like can be mentioned as examples.

[0032] Also effective are esters of saturated fatty acids and branched fatty alcohols, and ester compounds of unsaturated fatty acids or branched or substituted saturated fatty acids and branched aliphatic alcohols or aliphatic alcohols having 16 or more carbon atoms.

[0033] Examples of the ester compounds include 2-ethylhexyl butyrate, 2-ethylhexyl behenate, 2-ethylhexyl myristate, 2-ethylhexyl caprate, 3,5,5-trimethylhexyl laurate, 3,5,5-trimethylhexyl palmitate, 3,5,5-trimethylhexyl stearate, 2-methylbutyl caproate, 2-methylbutyl caprylate, 2-methylbutyl caprate, 1-ethylpropyl palmitate, 1-ethylpropyl stearate, 1-ethylpropyl behenate, and lauric acid. 1-Ethylhexyl Myristate, 1-Ethylhexyl Palmitate, 2-Methylpentyl Caproate, 2-Methylpentyl Caprylate, 2-Methylpentyl Caprate, 2-Methylpentyl Laurate, 2-Methylbutyl Stearate, 2-Methylbutyl Stearate, 3-Methylbutyl Stearate, 1-Methylheptyl Stearate, 2-Methylbutyl Behenate, 3-Methylbutyl Behenate, 1-Methylheptyl Stearate, 1-Methylheptyl Behenate, 1-Ethyl Caproate Pentyl, 1-ethylpentyl palmitate, 1-methylpropyl stearate, 1-methyloctyl stearate, 1-methylhexyl stearate, 1,1-dimethylpropyl laurate, 1-methylpentyl caprate, 2-methylhexyl palmitate, 2-methylhexyl stearate, 2-methylhexyl behenate, 3,7-dimethyloctyl laurate, 3,7-dimethyloctyl myristate, 3,7-dimethyloctyl palmitate, 3,7-dimethyloctyl stearate, 3,7 behenate Examples include 3,7-dimethyloctyl erucate, stearyl oleate, behenyl oleate, stearyl linoleate, behenyl linoleate, 3,7-dimethyloctyl erucate, stearyl erucate, isostearyl erucate, cetyl isostearate, stearyl isostearate, 2-methylpentyl 12-hydroxystearate, 2-ethylhexyl 18-bromostearate, isostearyl 2-ketomyristate, 2-ethylhexyl 2-fluoromyristate, cetyl butyrate, stearyl butyrate, and behenyl butyrate.

[0034] Furthermore, in order to cause a color change that exhibits large hysteresis characteristics in the color density-temperature curve and to impart color memory properties that depend on temperature changes, exemplified are carboxylic acid ester compounds that exhibit a ΔT value (melting point-cloud point) of 5°C or more and less than 50°C, as described in Japanese Patent Publication No. 4-17154, such as carboxylic acid esters containing a substituted aromatic ring in the molecule, esters of carboxylic acids containing an unsubstituted aromatic ring and aliphatic alcohols having 10 or more carbon atoms, carboxylic acid esters containing a cyclohexyl group in the molecule, esters of fatty acids having 6 or more carbon atoms and unsubstituted aromatic alcohols or phenols, esters of fatty acids having 8 or more carbon atoms and branched aliphatic alcohols, esters of dicarboxylic acids and aromatic alcohols or branched aliphatic alcohols, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, dimyristin, and distearin.

[0035] Also effective are fatty acid ester compounds obtained from an odd-numbered aliphatic monohydric alcohol having 9 or more carbon atoms and an even-numbered aliphatic carboxylic acid, and fatty acid ester compounds having a total of 17 to 23 carbon atoms obtained from n-pentyl alcohol or n-heptyl alcohol and an even-numbered aliphatic carboxylic acid having 10 to 16 carbon atoms.

[0036] Examples of fatty acid ester compounds include n-pentadecyl acetate, n-tridecyl butyrate, n-pentadecyl butyrate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caprylate, n-undecyl caprylate, n-tridecyl caprylate, n-pentadecyl caprylate, n-heptyl caprate, n-nonyl caprate, n-undecyl caprate, n-tridecyl caprate, n-pentadecyl caprate, n-pentyl laurate, n-heptyl laurate, n-nonyl laurate, n-undecyl laurate, n-tridecyl laurate, n-pentadecyl laurate, n-pentyl myristate, and n-heptyl myristate. , n-nonyl myristate, n-undecyl myristate, n-tridecyl myristate, n-pentadecyl myristate, n-pentyl palmitate, n-heptyl palmitate, n-nonyl palmitate, n-undecyl palmitate, n-tridecyl palmitate, n-pentadecyl palmitate, n-nonyl stearate, n-undecyl stearate, n-tridecyl stearate, n-pentadecyl stearate, n-nonyl eicosanoate, n-undelci eicosanoate, n-tridecyl eicosanoate, n-pentadecyl eicosanoate, n-nonyl behenate, n-undecyl behenate, n-tridecyl behenate, n-pentadecyl behenate, and the like.

[0037] As the ketones, aliphatic ketones having a total carbon number of 10 or more are effective, and examples thereof include 2-decanone, 3-decanone, 4-decanone, 2-undecanone, 3-undecanone, 4-undecanone, 5-undecanone, 2-dodecanone, 3-dodecanone, 4-dodecanone, 5-dodecanone, 2-tridecanone, 3-tridecanone, 2-tetradecanone, 2-pentadecanone, 8-pentadecanone, 2-hexadecanone, 3-hexadecanone, 9-heptadecanone, 2-pentadecanone, 2-octadecanone, 2-nonadecanone, 10-nonadecanone, 2-eicosanone, 11-eicosanone, 2-heneicosanone, 2-docosanone, laurone, stearone, and the like.

[0038] Further, aryl alkyl ketones having a total carbon number of 12 to 24, for example, n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradecanophenone, 4-n-dodecaacetophenone, n-tridecanophenone, 4-n-undecanoacetophenone, n-laurophenone, 4-n-decanoacetophenone, n-undecanophenone, 4-n-nonylacetophenone, n-decanophenone, 4-n-octylacetophenone, n ... Examples of acetophenone include 4-n-heptylacetophenone, n-octanophenone, 4-n-hexylacetophenone, 4-n-cyclohexylacetophenone, 4-tert-butylpropiophenone, n-heptaphenone, 4-n-pentylacetophenone, cyclohexyl phenyl ketone, benzyl-n-butyl ketone, 4-n-butylacetophenone, n-hexanophenone, 4-isobutylacetophenone, 1-acetonaphthone, 2-acetonaphthone, and cyclopentyl phenyl ketone.

[0039] As the ethers, aliphatic ethers having a total of 10 or more carbon atoms are effective, and examples thereof include dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecyl ether, diundecyl ether, didodecyl ether, ditridecyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, dioctadecyl ether, decanediol dimethyl ether, undecanediol dimethyl ether, dodecanediol dimethyl ether, tridecanediol dimethyl ether, decanediol diethyl ether, and undecanediol diethyl ether.

[0040] Examples of acid amides include acetamide, propionic acid amide, butyric acid amide, caproic acid amide, caprylic acid amide, capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, erucic acid amide, benzamide, caproic acid anilide, caprylic acid anilide, capric acid anilide, lauric acid anilide, myristic acid anilide, palmitic acid anilide, stearic acid anilide, behenic acid anilide, oleic acid anilide, erucic acid anilide, and N-methyl caproate. amide, caprylic acid N-methylamide, capric acid N-methylamide, lauric acid N-methylamide, myristic acid N-methylamide, palmitic acid N-methylamide, stearic acid N-methylamide, behenic acid N-methylamide, oleic acid N-methylamide, erucic acid N-methylamide, lauric acid N-ethylamide, myristic acid N-ethylamide, palmitic acid N-ethylamide, stearic acid N-ethylamide, oleic acid N-ethylamide, lauric acid N-butylamide, myristic acid N-butylamide, palmitic acid N-butylamide, stearate Stearic acid N-butylamide, oleic acid N-butylamide, lauric acid N-octylamide, myristic acid N-octylamide, palmitic acid N-octylamide, stearic acid N-octylamide, oleic acid N-octylamide, lauric acid N-dodecylamide, myristic acid N-dodecylamide, palmitic acid N-dodecylamide, stearic acid N-dodecylamide, oleic acid N-dodecylamide, dilauric acid amide, dimyristic acid amide, dipalmitic acid amide, distearic acid amide, dioleic acid amide, trilauric acid amide, trilauric acid amide Rimyristic acid amide, tripalmitic acid amide, tristearic acid amide, trioleic acid amide, succinic acid amide, adipic acid amide, glutaric acid amide, malonic acid amide, azelaic acid amide, maleic acid amide, succinic acid N-methylamide, adipic acid N-methylamide, glutaric acid N-methylamide, malonic acid N-methylamide, azelaic acid N-methylamide, succinic acid N-ethylamide, adipic acid N-ethylamide, glutaric acid N-ethylamide, malonic acid N-ethylamide, azelaic acid N-ethylamide, succinic acid N-butylamide,Examples include adipic acid N-butylamide, glutaric acid N-butylamide, malonic acid N-butylamide, adipic acid N-octylamide, and adipic acid N-dodecylamide.

[0041] Furthermore, the component (iii) may be a compound represented by the following formula (1). [ka] [wherein R1 represents a hydrogen atom or a methyl group, m represents an integer of 0 to 2, and either X1 or X2 represents -(CH2) n OCOR2 or (CH2) n COOR2, and the other represents a hydrogen atom; n represents an integer of 0 to 2; R2 represents an alkyl or alkenyl group having 4 or more carbon atoms; Y1 and Y2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom; and r and p each independently represent an integer of 1 to 3.

[0042] Of the compounds represented by formula (3), it is preferable that R1 is a hydrogen atom, since this results in a reversible thermochromic composition with a wider hysteresis width, and it is even more preferable that R1 is a hydrogen atom and m is 0.

[0043] Among the compounds represented by formula (1), the compound represented by the following formula (2) is more preferred. [ka] (In the formula, R represents an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, and more preferably an alkyl group having 12 to 22 carbon atoms.)

[0044] Examples of the compound represented by formula (2) include 4-benzyloxyphenylethyl octanoate, 4-benzyloxyphenylethyl nonanoate, 4-benzyloxyphenylethyl decanoate, 4-benzyloxyphenylethyl undecanoate, 4-benzyloxyphenylethyl dodecanoate, 4-benzyloxyphenylethyl tridecanoate, 4-benzyloxyphenylethyl tetradecanoate, 4-benzyloxyphenylethyl pentadecanoate, 4-benzyloxyphenylethyl hexadecanoate, 4-benzyloxyphenylethyl heptadecanoate, and 4-benzyloxyphenylethyl octadecanoate.

[0045] Furthermore, the component (iii) may be a compound represented by the following formula (3). [ka] (In the formula, R represents an alkyl or alkenyl group having 8 or more carbon atoms, m and n each independently represent an integer of 1 to 3, and X and Y each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom.)

[0046] Examples of the compound represented by formula (3) include 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, 1,1-diphenylmethyl dodecanoate, 1,1-diphenylmethyl tridecanoate, 1,1-diphenylmethyl tetradecanoate, 1,1-diphenylmethyl pentadecanoate, 1,1-diphenylmethyl hexadecanoate, 1,1-diphenylmethyl heptadecanoate, and 1,1-diphenylmethyl octadecanoate.

[0047] Furthermore, the component (iii) may be a compound represented by the following formula (4). [ka] (In the formula, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom; m represents an integer of 1 to 3; and n represents an integer of 1 to 20.)

[0048] Examples of the compound represented by formula (4) include a diester of malonic acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, a diester of succinic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of succinic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol, a diester of glutaric acid and 2-(4-benzyloxyphenyl)ethanol, a diester of glutaric acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, a diester of adipic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of pimelic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of suberic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of suberic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol, a diester of glutaric acid and 2-(4-benzyloxyphenyl)ethanol, a diester of adipic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of pimelic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of suberic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol, a diester of adipic acid and 2-(4-benzyloxyphenyl) ... Examples include the diester of suberic acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, the diester of suberic acid and 2-[4-(2,4-dichlorobenzyloxy)phenyl]ethanol, the diester of suberic acid and 2-[4-(2,4-dichlorobenzyloxy)phenyl]ethanol, the diester of azelaic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of sebacic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of 1,10-decanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of 1,18-octadecanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, and the diester of 1,18-octadecanedicarboxylic acid and 2-[4-(2-methylbenzyloxy)phenyl]ethanol.

[0049] Furthermore, the component (iii) may be a compound represented by the following formula (5). [ka] (In the formula, R represents an alkyl group or alkenyl group having 1 to 21 carbon atoms, and n represents an integer of 1 to 3.)

[0050] Examples of the compound represented by formula (5) include a diester of 1,3-bis(2-hydroxyethoxy)benzene and capric acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and undecanoic acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and lauric acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and myristic acid, a diester of 1,4-bis(hydroxymethoxy)benzene and butyric acid, a diester of 1,4-bis(hydroxymethoxy)benzene and isovaleric acid, and a diester of 1,4-bis(2-hydroxyethoxy)benzene and acetic acid. Examples of such esters include esters of 1,4-bis(2-hydroxyethoxy)benzene and propionic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and valeric acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and caproic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and caprylic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and capric acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and lauric acid, and diesters of 1,4-bis(2-hydroxyethoxy)benzene and myristic acid.

[0051] Furthermore, the component (iii) may be a compound represented by the following formula (6). [ka] (In the formula, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom; m represents an integer of 1 to 3; and n represents an integer of 1 to 20.)

[0052] Examples of the compound represented by formula (6) include a diester of succinic acid and 2-phenoxyethanol, a diester of suberic acid and 2-phenoxyethanol, a diester of sebacic acid and 2-phenoxyethanol, a diester of 1,10-decanedicarboxylic acid and 2-phenoxyethanol, and a diester of 1,18-octadecanedicarboxylic acid and 2-phenoxyethanol.

[0053] Furthermore, the component (iii) may be a compound represented by the following formula (7). [ka] (In the formula, R represents an alkyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, a cycloalkyl group, or an alkenyl group having 4 to 22 carbon atoms; X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom; and n represents 0 or 1.)

[0054] Examples of the compound represented by formula (7) include decyl 4-phenylbenzoate, lauryl 4-phenylbenzoate, myristyl 4-phenylbenzoate, cyclohexylethyl 4-phenylbenzoate, octyl 4-biphenylacetate, nonyl 4-biphenylacetate, decyl 4-biphenylacetate, lauryl 4-biphenylacetate, myristyl 4-biphenylacetate, tridecyl 4-biphenylacetate, pentadecyl 4-biphenylacetate, cetyl 4-biphenylacetate, cyclopentyl 4-biphenylacetate, cyclohexylmethyl 4-biphenylacetate, hexyl 4-biphenylacetate, and cyclohexylmethyl 4-biphenylacetate.

[0055] Furthermore, the component (iii) may be a compound represented by the following formula (8). [ka] (In the formula, R represents an alkyl group having 3 to 18 carbon atoms or an aliphatic acyl group having 3 to 18 carbon atoms; X represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a halogen atom; Y represents a hydrogen atom or a methyl group; and Z represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a halogen atom.) Examples of the compound represented by formula (8) include phenoxyethyl 4-butoxybenzoate, phenoxyethyl 4-pentyloxybenzoate, phenoxyethyl 4-tetradecyloxybenzoate, esters of phenoxyethyl 4-hydroxybenzoate and dodecanoic acid, and dodecyl ether of phenoxyethyl vanillate.

[0056] Furthermore, the component (iii) may be a compound represented by the following formula (9). [ka] (In the formula, R represents any one of an alkyl group having 4 to 22 carbon atoms, an alkenyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, and a cycloalkyl group; X represents any one of a hydrogen atom, an alkyl group, an alkoxy group, and a halogen atom; Y represents any one of a hydrogen atom, an alkyl group, an alkoxy group, and a halogen atom; and n represents 0 or 1.)

[0057] Examples of the compound represented by formula (9) include the benzoate ester of octyl 4-hydroxybenzoate, the benzoate ester of decyl 4-hydroxybenzoate, the 4-methoxybenzoate ester of heptyl 4-hydroxybenzoate, the 2-methoxybenzoate ester of dodecyl 4-hydroxybenzoate, and the benzoate ester of cyclohexylmethyl 4-hydroxybenzoate.

[0058] Furthermore, the component (iii) may be a compound represented by the following formula (10). [ka] (In the formula, R represents any one of an alkyl group having 3 to 18 carbon atoms, a cycloalkylalkyl group having 6 to 11 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, and an alkenyl group having 3 to 18 carbon atoms; X represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and a halogen atom; and Y represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, and a halogen atom.)

[0059] Examples of the compound represented by formula (10) include phenoxyethyl ether of nonyl 4-hydroxybenzoate, phenoxyethyl ether of decyl 4-hydroxybenzoate, phenoxyethyl ether of undecyl 4-hydroxybenzoate, and phenoxyethyl ether of dodecyl vanillate.

[0060] Furthermore, the component (iii) may be a compound represented by the following formula (11). [ka] (In the formula, R represents a cycloalkyl group having 3 to 8 carbon atoms or a cycloalkylalkyl group having 4 to 9 carbon atoms, and n represents an integer of 1 to 3.)

[0061] Examples of the compound represented by formula (11) include a diester of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanecarboxylic acid, a diester of 1,4-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid, and a diester of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid.

[0062] Furthermore, the component (iii) may be a compound represented by the following formula (12). [ka] (In the formula, R represents any one of an alkyl group having 3 to 17 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and a cycloalkylalkyl group having 5 to 8 carbon atoms; X represents any one of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a methoxy group, an ethoxy group, and a halogen atom; and n represents an integer of 1 to 3.)

[0063] Examples of the compound represented by formula (12) include a diester of 4-phenylphenol ethylene glycol ether and cyclohexanecarboxylic acid, a diester of 4-phenylphenol diethylene glycol ether and lauric acid, a diester of 4-phenylphenol triethylene glycol ether and cyclohexanecarboxylic acid, a diester of 4-phenylphenol ethylene glycol ether and octanoic acid, a diester of 4-phenylphenol ethylene glycol ether and nonanoic acid, a diester of 4-phenylphenol ethylene glycol ether and decanoic acid, and a diester of 4-phenylphenol ethylene glycol ether and myristic acid.

[0064] Furthermore, reversible thermochromic compositions of the heat-coloring type (which develops color upon heating and loses color upon cooling) can also be applied (see FIG. 3), using specific alkoxyphenol compounds having a linear or branched alkyl group with 3 to 18 carbon atoms as the electron-accepting compound (Japanese Patent Application Laid-Open Nos. 11-129623 and 11-5973), specific hydroxybenzoic acid esters (Japanese Patent Application Laid-Open No. 2001-105732), or gallic acid esters (Japanese Patent Application Laid-Open Nos. 51-44706 and 2003-253149).

[0065] The above-mentioned reversible thermochromic composition is a compatible solution containing the above-mentioned components (a), (b), and (c) as essential components, and the proportions of each component depend on the concentration, discoloration temperature, discoloration form, and type of each component. Generally, the component ratios that achieve the desired properties are in the range of 1 part of component (a) to 0.1 to 100, preferably 0.1 to 50, and more preferably 0.5 to 20, of component (b), and 5 to 200, preferably 5 to 100, and more preferably 10 to 100, of component (c) (all of the above proportions are in parts by mass).

[0066] Furthermore, the reversible thermochromic composition may contain various light stabilizers as required. The light stabilizer is included to prevent photodegradation of the reversible thermochromic composition consisting of components (A), (B), and (C), and is blended in a proportion of 0.3 to 24% by mass, preferably 0.3 to 16% by mass, per 1% by mass of component (A). Among the light stabilizers, ultraviolet absorbers effectively block ultraviolet rays contained in sunlight and the like, preventing photodegradation caused by the excited state resulting from the photoreaction of component (A). Furthermore, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers, etc., inhibit photooxidation reactions. The light stabilizers may be used alone or in combination of two or more.

[0067] In the present invention, the microcapsules have a specific structure, which is expressed by the average particle size (X) and average cross-sectional film thickness (Y) of the microcapsules contained in the microcapsule pigment or the ink composition.

[0068] In the present invention, the average particle size is a volume-based average particle size (median size). The optimal method for measuring the average particle size is to use a laser diffraction / scattering particle size distribution analyzer calibrated by a direct measurement method, such as the laser diffraction particle size distribution analyzer LA-300 (trade name, manufactured by Horiba, Ltd.).

[0069] Direct measurement methods used for calibration include: (i) Image analysis method to measure the area (2D) of individual particles from images taken with a microscope to determine their equivalent diameter; (ii) The Coulter method (electrical sensing zone method) uses a Coulter counter to pass a constant current through a tiny hole (aperture) in the detector, and measures the equivalent diameter from the change in impedance that occurs when a particle passes through the hole.Calibration of the laser measurement method is performed based on the values ​​obtained by these methods.

[0070] The average particle diameter can be measured by image analysis, for example, by determining the particle region using image analysis particle size distribution measurement software "MacView" (trade name, manufactured by Mountec Co., Ltd.), calculating the diameter equivalent to a circle with a projected area (Heywood diameter) from the area of ​​the particle region, and measuring the average particle diameter of particles equivalent to a sphere with an equal volume using this value. The measurement of average particle size by the Coulter method can be applied when the particle size of all or most of the particles exceeds 0.2 μm, and can be measured using, for example, a particle size distribution analyzer "Multisizer 4e" manufactured by Beckman Coulter, Inc.

[0071] Furthermore, the microcapsule pigment according to the present invention is specified by the average cross-sectional thickness (Y) of the microcapsules. The cross-sectional thickness can be obtained by image analysis of a cross-sectional image of the frozen microcapsule pigment. Specifically, (i) freezing a dispersion of the microencapsulated pigment, for example, a water dispersion; (ii) A thin section sample of 50 μm thickness was prepared using a microtome. (iii) The obtained thin film sample is observed using a transmission electron microscope, such as HT7700 (trade name, manufactured by Hitachi High-Technologies Corporation), in a field of view where the number of microcapsules within the field of view is approximately 100 to 200, (iv) For each microcapsule in the field of view, the area of ​​the region surrounded by the outer periphery of the cross section of the coating and the area of ​​the region surrounded by the inner periphery of the cross section of the coating are measured; (v) Calculating the outer diameter and inner diameter of the cross section from the two areas found, (vi) for all microcapsules in the field of view; Cut cross-section film thickness = (cross-section outer diameter - cross-section inner diameter) / 2 The cut cross-sectional thickness is calculated based on the above, and the average value is taken as the average cut cross-sectional thickness. The outer diameter and inner diameter of the cross section in (iv) and (v) can be determined using the image analysis software described above. The calculation of the average cross-sectional thickness in the present invention is for capsules whose cross-sectional thickness can be measured and calculated by the above (iv) and (v).

[0072] In this invention, the cross-sectional thickness does not simply correspond to the thickness of the microcapsule coating; it is a different parameter from the coating. Measuring the coating thickness of a microcapsule is generally very difficult. This is because, to directly observe the coating thickness, a cross-section passing through the center of the microcapsule must be observed. However, it is difficult to obtain such a cross-section for all microcapsules with a particle size distribution. Furthermore, although microcapsules often have a nearly spherical shape, they can become deformed due to the expansion and contraction of the inclusions, making it difficult to determine the center of the microcapsule. These combined factors make measuring the coating thickness difficult. In contrast, this invention focuses on the cross-sectional thickness instead of the coating thickness. This cross-sectional thickness does not coincide with the membrane thickness. This is because the cross-section formed when preparing a thin section sample often does not pass through the center of the microcapsule being cut. Furthermore, the fact that actual microcapsules have a particle size distribution further complicates measuring the particle size and coating thickness of microcapsules.

[0073] On the other hand, the present invention was completed based on the finding that microcapsule pigments exhibit excellent effects when these parameters and the average particle size satisfy certain conditions. First, the microcapsules contained in the microcapsule pigment according to the present invention have a volume-based average particle diameter (X) of 0.1 to 5.0 μm, preferably 0.5 to 5.0 μm. If the volume-based average particle diameter (X) of the microcapsules is excessively small, the color density generally tends to decrease, while if it is excessively large, it may cause the microcapsules to settle or clog the ink flow path, so care must be taken. Therefore, by ensuring that the volume-based average particle diameter (X) is within the above range, the color density and dispersion stability of compositions containing the microcapsule pigment can be maintained at a good level.

[0074] Furthermore, the microcapsules contained in the microcapsule pigment according to the present invention have an average cross-sectional thickness (Y) of 0.02 to 1.0 μm, preferably 0.05 to 0.8 μm. By keeping the average cross-sectional thickness (Y) within an appropriate range, it is possible to obtain a reversible thermochromic microcapsule pigment that has an excellent balance between durability and color density.

[0075] Furthermore, in the present invention, the ratio Y / X of the average particle diameter (X) to the average cross-sectional film thickness (Y) of the microcapsules preferably satisfies the following formula (1), more preferably (1a), and sometimes preferably (1b): Furthermore, the ratio Y / X preferably satisfies the following formula (2), more preferably (2a), and sometimes preferably (2b): By keeping the ratio Y / X within an appropriate range, a reversible thermochromic microcapsule pigment having an excellent balance between durability and color density can be obtained. Y / X<0.3 (1) Y / X<0.25 (1a) Y / X<0.2 (1b) 0.02 <Y / X (2) 0.03 <Y / X (2a) 0.04 <Y / X (2b)

[0076] [Method of manufacturing microcapsules] The microcapsule pigment according to the present invention comprises microcapsules having a coating encapsulating a reversible thermochromic composition containing the above-mentioned components (a), (b), and (c).

[0077] By encapsulating the reversible thermochromic composition in microcapsules, a chemically and physically stable pigment can be formed. Furthermore, the reversible thermochromic composition maintains the same composition under various conditions of use, allowing it to exhibit the same effects.

[0078] The microencapsulation method is appropriately selected depending on the application from conventionally known manufacturing methods such as an isocyanate-based interfacial polymerization method, an in situ polymerization method such as a melamine-formalin-based method, a liquid curing coating method, a phase separation method from an aqueous solution, a phase separation method from an organic solvent, a melt-dispersion cooling method, an air suspension coating method, a spray drying method, etc. Furthermore, a secondary resin coating can be further provided on the surface of the microcapsules depending on the purpose to impart durability or to modify the surface properties for practical use.

[0079] The microcapsule pigment of the present invention requires that the average particle size (X) and average cross-sectional film thickness (Y) of the microcapsules contained therein satisfy specific conditions. To satisfy the specific conditions, it is necessary to adjust the manufacturing conditions of the microcapsules. As mentioned above, there are various methods for producing microcapsules, and the appropriate conditions vary depending on each method. Furthermore, the appropriate conditions also vary depending on the components constituting the reversibly thermochromic composition used and the components forming the microcapsule coating. Therefore, in order to produce the microcapsules according to the present invention, it is common to create a calibration curve for different production conditions and search for the optimal conditions.

[0080] For example, when microcapsules are produced by interfacial polymerization, the average particle size (X) and average cross-sectional thickness (Y) of the microcapsules vary depending on factors such as the polymerization temperature, polymerization time, the blending ratio of the reversible thermochromic composition to the coating material, and the stirring speed of the reaction solution. Several types of microcapsules are produced by varying only one of these parameters, and the average particle size (X) and average cross-sectional thickness (Y) are measured to create a calibration curve. If the production conditions for the desired microcapsules cannot be determined using this calibration curve alone, another parameter is varied to create a calibration curve. In this way, microcapsules with the desired average particle size (X) and average cross-sectional thickness (Y) can be produced.

[0081] [Reversible thermochromic liquid composition] The reversibly thermochromic microencapsulated pigment according to the present invention can be dispersed in a vehicle containing water and / or an organic solvent and, if necessary, various additives to form a reversibly thermochromic liquid composition, such as an ink composition (hereinafter, sometimes referred to as "ink"), which can be used as a reversibly thermochromic liquid composition such as printing ink used in screen printing, offset printing, process printing, gravure printing, coater printing, pad printing, etc.; paint used in brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, dip coating, etc.; ultraviolet-curable ink; ink for applicators; ink for stamps; paints; cosmetics such as nail polish, makeup cosmetics, and hair cosmetics; and fiber coloring liquids.

[0082] The liquid composition according to the present invention may contain various additives. Examples of additives include resins, crosslinking agents, curing agents, drying agents, plasticizers, viscosity modifiers, dispersants, ultraviolet absorbers, antioxidants, light stabilizers, anti-settling agents, smoothing agents, gelling agents, antifoaming agents, matting agents, penetrating agents, pH adjusters, foaming agents, coupling agents, moisturizing agents, antifungal agents, preservatives, and rust inhibitors.

[0083] Furthermore, although water is used as a medium for the liquid composition of the present invention, a water-soluble organic solvent can also be used if necessary. Examples of water-soluble organic solvents include glycols such as glycerin, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,3-butylene glycol, and ethylene glycol monomethyl ether, as well as lower alkyl ethers thereof, 2-pyrrolidone, N-vinylpyrrolidone, and urea. Among the water-soluble organic solvents, glycerin and propylene glycol are preferred.

[0084] The water-soluble organic solvent is preferably blended in an amount of 30 to 60% by mass, more preferably 30 to 55% by mass, and even more preferably 40 to 50% by mass, based on the total amount of the liquid composition. When the blending ratio of the water-soluble organic solvent is within an appropriate range, the liquid composition does not dry out or absorb moisture, making it easier to obtain a clear image.

[0085] In addition to the water-soluble organic solvent, an organic solvent can also be used as the medium. Examples of organic solvents include cellosolve-based solvents such as castor oil fatty acid alkyl esters, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, and ethyl cellosolve acetate; ethylene glycol acetate, ethylene glycol diethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol monomethyl ether acetate, and tripropylene glycol monomethyl ether; Alkyl glycol solvents, ethyl formate, amyl formate, ethyl acetate, ethyl acetoacetate, propyl acetate, butyl acetate, 3-methyl-3-methoxybutyl acetate, amyl acetate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, butyl-3-methoxypropionate, methyl lactate, ethyl lactate, ethyl-2-hydroxybutyrate, butyl butyrate, butyl stearate, ethyl caprylamide Ester solvents such as plate, diethyl oxalate, ethyl pyruvate, ethyl benzoate, etc.; hydrocarbon solvents such as n-pentane, n-hexane, n-octane, n-dodecane, diisobutylene, dipentene, hexene, methylcyclohexene, bicyclohexyl, mineral spirits, etc.; halogenated hydrocarbon solvents such as amyl chloride and butyl chloride, alcohol solvents such as 3-methoxy-3-methylbutanol and 3-methoxy-3-methylpentanol, diethyl ether, dipropyl ether, ethyl isobutyl ether, dibutyl ether,Examples of such solvents include ether solvents such as diisopropyl ether, diamyl ether, and dihexyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl isoamyl ketone, ethyl amyl ketone, methyl hexyl ketone, methyl nonyl ketone, diisopropyl ketone, diisobutyl ketone, methoxymethyl pentanone, and cyclohexanone; propionic acid solvents such as 3-methoxypropionic acid and 3-ethoxypropionic acid; highly polar solvents such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, and benzonitrile; and mixed solvents thereof.

[0086] Furthermore, a thickener may be added to the liquid composition. Examples of thickeners include xanthan gum, welan gum, succinoglycan (average molecular weight: about 1,000,000 to 8,000,000), which is an organic acid-modified heteropolysaccharide whose constituent monosaccharides are glucose and galactose, guar gum, locust bean gum and its derivatives, hydroxyethyl cellulose, alginic acid alkyl esters, polymers having a molecular weight of 100,000 to 150,000 and whose main component is an alkyl ester of methacrylic acid, glycomannan, thickening polysaccharides having gelling ability extracted from seaweed such as agar and carrageenin, benzylidene sorbitol and benzylidene xylitol, or the like. Examples of such surfactants include derivatives of these surfactants, crosslinkable acrylic acid polymers, inorganic fine particles, polyglycerin fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyethylene glycol fatty acid esters, polyoxyethylene castor oil, polyoxyethylene lanolin / lanolin alcohol / beeswax derivatives, polyoxyethylene alkyl ethers / polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, fatty acid amides, and other nonionic surfactants having an HLB value of 8 to 12, and salts of dialkyl or dialkenyl sulfosuccinic acid.

[0087] Among the thickeners, alkali-soluble acrylic emulsions are preferred. When an alkali-soluble acrylic emulsion is used as a thickener, the pH of the ink is adjusted to preferably 6-11, more preferably 7-11, and even more preferably 7-10.

[0088] Furthermore, by adding a binder resin to the liquid composition, the image fixing property can be improved and the viscosity of the liquid composition can be adjusted. Examples of the binder resin include a resin emulsion, an alkali-soluble resin, and a water-soluble resin.

[0089] Examples of resin emulsions include aqueous dispersions of polyacrylic acid esters, styrene-acrylic acid copolymers, polyvinyl acetate, ethylene-vinyl acetate copolymers, ethylene-vinyl chloride copolymers, methacrylic acid-maleic acid copolymers, ethylene-methacrylic acid copolymers, α-olefin-maleic acid copolymers, polyesters, polyurethanes, and the like.

[0090] Examples of alkali-soluble resins include styrene-maleic acid copolymers, ethylene-maleic acid copolymers, and styrene-acrylic acid copolymers. Examples of the water-soluble resin include polyvinyl alcohol and polyvinyl butyral. The resin emulsions may be used alone or in combination of two or more.

[0091] In addition, various additives such as a pH adjuster, a preservative, or an antifungal agent may be added as needed. Examples of pH adjusters include inorganic salts such as ammonia, sodium carbonate, sodium phosphate, sodium hydroxide, and sodium acetate, and organic basic compounds such as water-soluble amine compounds such as triethanolamine and diethanolamine. Examples of antiseptics or antifungal agents include carbolic acid, sodium salt of 1,2-benzisothiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl parahydroxybenzoate, and 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine. Other additives include fluorine-based surfactants, nonionic surfactants, anionic surfactants, cationic surfactants, dimethylpolysiloxane, and the like, which improve the permeability of the solvent.

[0092] If necessary, resins such as acrylic resins, styrene-maleic acid copolymers, cellulose derivatives, polyvinylpyrrolidone, polyvinyl alcohol, and dextrin can be added to impart adhesiveness and viscosity to the paper surface.

[0093] Additionally, rust inhibitors such as benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, and saponin, urea, nonionic surfactants, reduced or non-reduced starch hydrolysates and oligosaccharides such as trehalose, wetting agents such as sucrose, cyclodextrin, glucose, dextrin, sorbitol, mannitol, and sodium pyrophosphate, antifoaming agents, dispersants, fluorine-based surfactants that improve the permeability of the liquid composition, and nonionic surfactants may also be blended.

[0094] The liquid composition of the present invention preferably contains 10 to 40% by mass, more preferably 10 to 35% by mass, and even more preferably 10 to 30% by mass of a reversible thermochromic microencapsulated pigment relative to the total mass of the liquid composition. If the proportion of the microencapsulated pigment exceeds 40% by mass, the dispersion stability of the microencapsulated pigment in the ink tends to decrease. On the other hand, if the proportion of the microencapsulated pigment is less than 10% by mass, the color density may be low.

[0095] When applying or printing the liquid composition according to the present invention, the material of the support is not particularly limited and all materials are effective, such as paper, synthetic paper, fiber, fabric, synthetic leather, leather, plastic, glass, ceramic material, metal, wood, stone, etc. The shape of the support is not limited to a flat surface, but may be uneven. A reversible thermochromic laminate (reversible thermochromic printed matter) can be obtained by providing a reversible thermochromic layer containing the reversible thermochromic microcapsule pigment of the present invention on a support. In the case where a non-thermochromic colored layer (non-thermochromic image) is pre-formed on the support, the colored layer or image can be made to disappear or appear by the reversible thermochromic layer due to a change in temperature, further diversifying the manner of change.

[0096] [Solid molded product for reversible thermochromic coating] The reversibly thermochromic microencapsulated pigment of the present invention can be melt-blended with an excipient and molded into a reversibly thermochromic solid molding for application, which can be used as a solid writing material or a solid cosmetic. Examples of solid writing materials include crayons, pencil leads, mechanical pencil leads, solid gel markers, and the like. Examples of solid cosmetics include foundation, eyeliner, eyebrow pencil, eyeshadow, lipstick, etc.

[0097] Examples of excipients used in solid writing materials include waxes, gelling agents, clays, and the like. The wax is not particularly limited as long as it is a conventionally known wax, and examples thereof include carnauba wax, Japan wax, beeswax, microcrystalline wax, montan wax, candelilla wax, sucrose fatty acid ester, dextrin fatty acid ester, polyolefin wax, styrene-modified polyolefin wax, and paraffin wax.

[0098] The gelling agent is not particularly limited as long as it is a conventionally known agent, and examples thereof include 12-hydroxystearic acid, dibenzylidene sorbitols, tribenzylidene sorbitols, amino acid oils, and alkali metal salts of higher fatty acids. Examples of clay minerals include kaolin, bentonite, and montmorillonite.

[0099] Among the excipients, it is preferable to contain at least one of polyolefin wax, sucrose fatty acid ester, and dextrin fatty acid ester, as these excipients are likely to improve the density of the writing. Examples of polyolefin waxes include waxes such as polyethylene, polypropylene, polybutylene, α-olefin polymers, ethylene-propylene copolymers, and ethylene-butene copolymers.

[0100] Furthermore, among polyolefin waxes, those having a softening point in the range of 100 to 130° C. and a penetration of 10 or less are preferred because they are easy to write with. If the penetration exceeds 10, the solid writing material becomes too soft, making it difficult to write with, and when the handwriting is erased, it spreads on the paper surface (the wax becomes a thin layer), which can stain the blank areas on the writing surface and can easily transfer color or stain other papers. The softening point and penetration of the polyolefin wax can be measured in accordance with the measurement method specified in JIS K2207, with a penetration value of 0.1 mm being expressed as 1. In other words, the smaller the penetration value of the solid writing material, the harder it is, and the larger the penetration value, the softer it is.

[0101] Specific examples of polyolefin waxes include the Neowax series (trade name, manufactured by Yasuhara Chemical Co., Ltd.), the Sanwax series (trade name, manufactured by Sanyo Chemical Industries, Ltd.), the Hiwax series (trade name, manufactured by Mitsui Chemicals, Inc.), and AC Polyethylene (trade name, manufactured by Honeywell Japan, Ltd.).

[0102] As the sucrose fatty acid ester, an ester having a fatty acid having 12 to 22 carbon atoms as a constituent fatty acid is preferred, and palmitic acid and stearic acid are more preferred. Specific examples of sucrose fatty acid esters include the Ryoto Sugar Ester series (trade name, manufactured by Mitsubishi Chemical Foods Corporation) and the Sugar Wax series (trade name, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).

[0103] As the dextrin fatty acid ester, an ester having a constituent fatty acid of 14 to 18 carbon atoms is preferred, and palmitic acid, myristic acid, and stearic acid are more preferred. Specific examples of dextrin fatty acid esters include the Leopearl series (trade name, manufactured by Chiba Flour Milling Co., Ltd.).

[0104] In addition, side-chain crystalline polyolefins are preferred as excipients used in solid writing materials.Here, side-chain crystalline polyolefins have a structure in which a relatively long side chain is bonded to a linear main chain.Normal linear polyolefins tend to melt over a wide temperature range because the linear main chain is folded and crystallizes, whereas side-chain crystalline polyolefins crystallize mainly in the side chain rather than the polyolefin main chain, resulting in a low melting point (Mp) and a narrow temperature range. Among such side-chain crystalline polyolefins, those having a long-chain alkyl group in the side chain with 12 to 28 carbon atoms are particularly preferred. The long-chain alkyl group in the side chain is not particularly limited and may be either a straight-chain or branched type, but a straight-chain long-chain alkyl group is preferred because it provides excellent crystallinity.

[0105] The alkyl group on the side chain may have a substituent, but the substituent tends to decrease the crystallinity, and therefore, in order to adjust the crystallinity, the side chain of the side-chain crystalline polyolefin can be modified with, for example, styrene, etc. Furthermore, if the long-chain alkyl group has a functional group that forms a hydrogen bond, the long-chain alkyl groups are bonded to each other by the hydrogen bond and aggregate, thereby improving the crystallinity, which is preferable.

[0106] Furthermore, side-chain crystalline polyolefins include polyolefins with a highly branched structure (hereinafter referred to as "highly branched polyolefins"), which can also be used as excipients. Highly branched polyolefins have the characteristic that their main chains are difficult to fold during crystallization, resulting in a low melting point and melting occurring within a narrow temperature range.

[0107] In order to provide the solid writing material with excellent mechanical strength and thermal discoloration properties and to facilitate handling during production, the excipient preferably has a weight-average molecular weight (Mw) of 2,000 to 50,000, more preferably 10,000 to 30,000, and more preferably a number-average molecular weight (Mn) of 1,000 to 10,000. The weight average molecular weight and number average molecular weight are values ​​measured by gel permeation chromatography (GPC) using polystyrene as a standard.

[0108] Specific examples of side chain crystalline polyolefins include those manufactured by Toyokuni Oil Mills Co., Ltd., product names: HS Crysta 4100 (Mw: 16,000, Mp: 44.4°C) and HS Crysta 6100 (Mw: 28,000, melting point: 60.6°C), and those manufactured by Idemitsu Kosan Co., Ltd., product names: El Crysta 4100 (Mw: 16,000) and HS Crysta 6100 (Mw: 28,000). Specific examples of highly branched polyolefins include VYBAR103 (Mw: 17,348, Mn: 4,400, Mp: 67.7°C), VYBAR260 (Mw: 20,278, Mn: 2,600, Mp: 54.7°C), VYBAR343 (Mw: 10,164, Mp: 36.0°C), and VYBAR825 (Mn: 2,800) (all trade names, manufactured by Baker Hughes Japan, Ltd.).

[0109] The filler is preferably blended in the range of 0.2 to 70% by mass, more preferably 0.5 to 40% by mass, based on the total amount of the solid writing material. When the blending ratio of the filler is within an appropriate range, the shape of the solid writing material can be easily obtained, and the writing density of the solid writing material can easily be increased.

[0110] If the blending ratio of the excipient exceeds 70% by mass, it becomes difficult to obtain sufficient writing density, whereas if the blending ratio of the excipient is less than 0.2% by mass, it becomes difficult to obtain a shape suitable for a writable core material.

[0111] Furthermore, by blending a filler into the solid writing material, it is possible to improve the strength of the solid writing material and adjust the writing feel.

[0112] Examples of the filler include talc, clay, silica, calcium carbonate, barium sulfate, alumina, mica, boron nitride, potassium titanate, and glass flakes. Among fillers, talc or calcium carbonate is preferred because it has excellent moldability and is less likely to impair thermochromic properties when a microcapsule pigment is used.

[0113] The filler is preferably blended in the range of 10 to 65% by mass based on the total amount of the solid writing material. If the blending ratio of the filler exceeds 65% by mass, the color development and writing feel tend to deteriorate. On the other hand, if the blending ratio of the filler is less than 10% by mass, the strength of the solid writing material tends to deteriorate.

[0114] Furthermore, by blending a binder resin into the solid writing material, the strength of the solid writing material can be improved.

[0115] Examples of binder resins include natural resins and synthetic resins, such as olefin resins, cellulose resins, vinyl alcohol resins, pyrrolidone resins, acrylic resins, styrene resins, amide resins, and basic group-containing resins.

[0116] Among the binder resins, ethylene-vinyl acetate copolymer resin, ethylene-vinyl alcohol copolymer resin, and polyvinyl alcohol resin are preferred, and molding stability can be improved by using these resins in combination with polyester polyol resin. The binder resin is preferably blended in the range of 0.5 to 5% by mass based on the total amount of the solid writing material.

[0117] Furthermore, by incorporating a hindered amine compound into the solid writing material, it is possible to make afterimages of erased writing on the writing surface less visible, thereby ensuring rewritability without impairing the appearance of the writing surface and improving marketability.

[0118] The hindered amine compound preferably has a molecular weight of 1000 or less, since it is highly compatible with other components, does not easily bleed out, and can form clear handwriting even after the passage of time. The melting point is preferably 120° C. or lower. A low melting point allows the solid writing material to be produced without applying excessive heat during production, and prevents deterioration of the reversible thermochromic colorant contained in the solid writing material, such as the reversible thermochromic composition, reversible thermochromic microcapsule pigment, or resin particles.

[0119] In addition, various additives may be added as needed. Examples of additives include viscosity adjusters, antifungal agents or preservatives, antibacterial agents, ultraviolet inhibitors, antioxidants, lubricants, and fragrances.

[0120] The solid writing material may be used alone as a writing material, or may be used as an inner core with an outer shell covering the outer periphery to form a core-sheath structure (double core).

[0121] The outer shell prevents the solid writing body (core) inside from being damaged by physical contact and contributes to improving the mechanical strength of the entire solid writing body. The outer shell may or may not contain a reversible thermochromic colorant, such as a reversible thermochromic composition, a reversible thermochromic microcapsule pigment, or resin particles, which contributes to the formation of handwriting. However, since the tip of a solid writing body is generally sharpened into a cone shape, the outer shell often does not affect the handwriting. For this reason, it is common for reversible thermochromic colorants not to be blended into the outer shell.

[0122] If necessary, various additives can be added to the shell. Examples of additives include non-thermochromic colorants, antifungal agents or preservatives, antibacterial agents, ultraviolet absorbers, antioxidants, lubricants, and fragrances.

[0123] The solid writing material can be produced by a production method such as extrusion molding or compression molding. The above-mentioned solid writing material having a core-sheath structure in which an outer shell is provided to cover the outer surface of the inner core can be manufactured, for example, by a manufacturing method in which an outer shell is disposed on the outer surface of a block of the inner core and compression-molded using a press.

[0124] The thickness and length of the solid writing material are selected as desired depending on the purpose. For example, when the solid writing material is used as a pencil lead, the thickness is generally 2.0 to 5.0 mm, preferably 2.5 to 4.0 mm. The length is 60 to 300 mm, preferably 80 to 200 mm.

[0125] Furthermore, when the solid writing material has a core-sheath structure, the thickness of the inner core and the thickness of the outer shell can be selected as desired. A thicker outer shell provides better impact resistance, while a thinner outer shell exposes more of the inner core, making it easier to use. The thickness of the outer shell relative to the radial length of the inner core is preferably in the range of 10 to 100%, more preferably 20 to 50%.

[0126] The thickness and length of the solid writing material are adjusted appropriately depending on the application other than pencils, for example, lead for mechanical pencils, crayons, etc.

[0127] The solid writing material of the present invention can be used to write on various writing surfaces, and since it uses a reversible thermochromic microencapsulated pigment, the handwriting written on the writing surface can be discolored by rubbing it with a finger or by applying the above-mentioned heating or cooling tool. As the heating tool can be easily discolored, the above-mentioned friction member is preferred.

[0128] Although a solid writing body set can be obtained by combining a solid writing body with a friction member (friction body) of any shape that is separate from the solid writing body, a solid writing body set with excellent portability can be obtained by providing a friction member on the solid writing body or on the exterior of a solid writing implement in which the solid writing body is housed in an exterior container. Specifically, examples include a form in which a friction member is provided on an exterior shaped like a pencil or crayon, made of wood or paper, etc.

[0129] [Reversible thermochromic molding resin composition] Furthermore, the reversible thermochromic microencapsulated pigment according to the present invention can be melt-blended with a molding resin, such as a thermoplastic resin, a thermosetting resin, or wax, to form pellets, powder, or a paste, and used as a reversible thermochromic molding resin composition.

[0130] The reversible thermochromic molding resin composition of the present invention can be subjected to general-purpose injection molding, extrusion molding, blow molding, cast molding or the like to obtain molded articles in the form of three-dimensional objects of any shape, films, sheets, plates, filaments, rods, pipes and the like. Furthermore, by melt-blending it with a thermoplastic resin, toner and powder coatings can be obtained.

[0131] In addition, by blending a non-thermochromic colorant such as a general dye or pigment into the reversibly thermochromic liquid composition, solid molding for coating, or resin composition for molding, it is possible to make it exhibit a color change behavior from color (1) to color (2).

[0132] On a molded article or laminate containing the microcapsulated pigment according to the present invention, a layer containing a light stabilizer and / or a transparent metallic luster pigment can be laminated to improve light resistance, or a top coat layer can be provided to improve durability.

[0133] Examples of light stabilizers include ultraviolet absorbers, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, and ozone quenchers.

[0134] Examples of transparent metallic luster pigments include pigments having a core material such as natural mica, synthetic mica, glass flakes, alumina, or transparent film flakes whose surface is coated with a metal oxide such as titanium oxide.

[0135] [Application examples of microcapsule pigments] Specific examples of products using the reversible thermochromic microcapsule pigment of the present invention include the following. (1)Toys Dolls and animal-shaped toys, hair for dolls and animal-shaped toys, doll houses and furniture, clothes, doll accessories such as hats, bags, shoes, accessory toys, stuffed toys, drawing toys, toy picture books, puzzle toys such as jigsaw puzzles, building block toys, block toys, clay toys, fluid toys, tops, kites, musical instrument toys, cooking toys, gun toys, catching toys, background toys, toys imitating vehicles, animals, plants, buildings, food, etc. (2) Clothing Clothing such as T-shirts, sweatshirts, blouses, dresses, swimwear, raincoats, skiwear, footwear such as shoes and shoelaces, cloth accessories such as handkerchiefs, towels, wrapping cloths, gloves, ties, hats, scarves, mufflers, etc. (3) Indoor decorations Carpets, curtains, curtain strings, tablecloths, rugs, cushions, carpets, rugs, chair upholstery, seats, mats, picture frames, artificial flowers, photo frames, etc. (4) Furniture Bedding such as futons, pillows, mattresses, lighting equipment, heating and cooling equipment, etc. (5) Ornaments Rings, bracelets, tiaras, earrings, hair clips, false nails, ribbons, scarves, watches, glasses, etc. (6) Stationery Stamps, erasers, writing pads, rulers, notebooks, adhesive tape, etc. (7)Daily necessities Lipstick, eye shadow, foundation, eyeliner, eyebrow pencil, nail polish, hair dye, false nails, false nail paint, and other cosmetics, toothbrushes, etc. (8) Kitchen utensils Cups, plates, chopsticks, spoons, forks, pots, frying pans, etc. (9) Other Calendars, labels, cards, recording materials, various types of printed materials for preventing counterfeiting, picture books and other books, bags, packaging containers, embroidery thread, sports equipment, fishing tackle, coasters, musical instruments, hand warmers, ice packs, wallets and other bags, umbrellas, vehicles, buildings, temperature detection indicators, training tools, etc.

[0136] [Example]

[0137] Examples are shown below, in which "parts" refers to parts by mass.

[0138] Example 1 (Preparation of reversible thermochromic microcapsule pigment) A reversible thermochromic composition was prepared by mixing 2 parts of 3',6'-bis[phenyl(3-methylphenyl)amino]-spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one as component (A), 8 parts of 2,2-bis(4-hydroxyphenyl)hexafluoropropane as component (B), and 50 parts of 4-benzyloxyphenylethyl caprate as component (C). This composition was then added to a mixed solution consisting of 45 parts of aromatic isocyanate prepolymer as a coating material and 40 parts of a cosolvent. This mixed solution was emulsified and dispersed in a 10% aqueous polyvinyl alcohol solution. After stirring at 10,000 rpm with a homomixer while heating, 2.5 parts of a water-soluble aliphatic modified amine was added and further stirring was continued to prepare a microcapsule dispersion. The microcapsule dispersion was filtered using a filter press to obtain a reversible thermochromic microcapsule pigment.

[0139] The average particle size (X) of the microcapsules contained in the reversible thermochromic microcapsule pigment was measured using a laser diffraction / scattering particle size distribution analyzer (LA-300 (trade name, manufactured by Horiba, Ltd.)) calibrated by image analysis. The volume-based average particle size (X) obtained was 0.75 μm.

[0140] The average cross-sectional thickness (Y) of the microcapsules contained in the reversible thermochromic microcapsule pigment was measured by freezing an aqueous dispersion of the pigment in a reversible thermochromic composition colored state, eliminating any variation in the pigment's shape, and then microtome-processing it to prepare a 50 μm-thick thin section sample. Images were then analyzed using a transmission electron microscope HT7700 (trade name, manufactured by Hitachi High-Tech Corporation). The number of microcapsules within the field of view of the observed image was 150. The cross-sectional thicknesses of all microcapsules were calculated by image analysis, and the average cross-sectional thickness (Y) obtained from the average was 0.08 μm.

[0141] Examples 2 to 33 and Comparative Examples 1 and 2 (Preparation of reversible thermochromic microcapsule pigment) The amount of coating material added and the stirring speed of Example 1 were adjusted to obtain reversible thermochromic microcapsule pigments of Examples 2 to 33.

[0142] (Preparation of reversible thermochromic liquid composition and sample) A reversible thermochromic liquid composition (ink composition) was prepared by mixing 40 parts of each of the reversible thermochromic microcapsule pigments obtained in Examples 2 to 33 or Comparative Examples 1 or 2, 52 parts of an ethylene-vinyl acetate copolymer resin emulsion, 5 parts of a thickener, 4 parts of ethylene glycol, and 3 parts of a leveling agent.

[0143] (Color density test during color development) Using the obtained reversibly thermochromic liquid composition, a solid pattern was screen-printed on a wood-free paper to provide a reversibly thermochromic layer, thereby obtaining a sample.

[0144] The color density of the reversible thermochromic layer of each sample in the colored state was visually observed. The evaluation criteria were as follows: A: Very dark and clear. B: Strong. C: Slightly pale in color, but still visible. D: The color is a little pale, but it doesn't affect the practicality. E: The color is light and visibility is low, which is problematic for practical use.

[0145] (Durability test of microcapsule coating) Immediately after preparation, the reversible thermochromic liquid composition of each example was used to screen-print a solid pattern on wood-free paper to form a reversible thermochromic layer, thereby obtaining an initial sample.Furthermore, after leaving the composition of each example at 40°C for 30 days, screen-printing was performed in the same manner to obtain an aged sample. The color density of the initial sample and the sample after aging obtained in each example was visually observed. The evaluation criteria were as follows: A: The color density of the sample after aging remains unchanged compared to the initial sample. B: The color density of the sample after aging shows almost no change compared to the initial test sample. C: The color density of the aged sample is slightly lighter than that of the initial sample, but is still visible. D: The color density of the aged sample is somewhat lighter than that of the initial sample, but this is not a problem for practical use. E: The color density of the aged sample was lighter than that of the initial sample, and visibility was low, which is problematic for practical use.

[0146] Table 1 below shows the average particle size (X) of the microcapsules contained in the reversible thermochromic microcapsule pigments of Examples 1 to 33 and Comparative Examples 1 and 2, the average cross-sectional film thickness (Y), Y / X, the color density test results upon color development, and the durability test results of the microcapsule coating.

[0147] [Table 1]

[0148] Application example 1 (reversible thermochromic mug) A reversible thermochromic liquid composition (epoxy ink) was obtained by mixing 30 parts of the reversible thermochromic microcapsule pigment prepared in Example 2 (previously cooled to -18°C or below to develop a blue color), 60 parts of a hard liquid epoxy resin, 2 parts of an ultraviolet absorber, 2 parts of a thixotropic agent, and 0.5 parts of an antifoaming agent, and then adding 40 parts of a room-temperature-curing aliphatic polyamine.

[0149] Using the obtained epoxy ink, a polka dot pattern was printed on the side of a ceramic mug using a curved printing machine with a stainless steel screen plate, and the ink was then heated and cured at 70°C for 1 hour to form a reversible thermochromic layer, resulting in a reversible thermochromic mug.

[0150] When hot water above 64°C is poured into the mug, it turns white, and this state remains visible as long as the temperature is kept between -18°C and 64°C. Furthermore, when the mug was cooled to below -18°C and the reversible thermochromic layer was allowed to fully develop its color, it became a mug with a blue polka dot pattern and could be used repeatedly.

[0151] Application example 2 (Stamp creation) A reversible thermochromic liquid composition (stamp ink composition) was prepared by mixing 20 parts of the reversible thermochromic microcapsule pigment prepared in Example 6 (which had been cooled to -18°C or below in advance to develop a blue color), 50 parts of glycerin, 1.5 parts of an alkali-soluble acrylic emulsion (manufactured by Rohm and Haas Japan Co., Ltd., product name: Primal DR73), 0.9 parts of triethanolamine, 10 parts of a 50% aqueous solution of polyvinylpyrrolidone, 0.2 parts of a silicone-based antifoaming agent, 0.5 parts of a penetrating leveling agent, 0.2 parts of a preservative, and 16.7 parts of water.

[0152] The resulting ink composition for stamps was impregnated into a stamp material having continuous pores, and the stamp material was fixed to a stamp base material so that the printing surface of the stamp material was exposed, and a cap was fitted to prepare a stamp. The rear end of the stamp base material is fitted with SEBS resin as a friction member. When the stamp was repeatedly pressed against the surface to be stamped (paper), the ink flowed smoothly from the surface of the stamping material and transferred to the surface to be stamped, allowing clear, continuous prints to be formed without bleeding.

[0153] The printed image was blue at room temperature (25°C), and when rubbed with a friction member, the printed image was erased and became colorless, and this state could be maintained unless cooled to -18°C or below.

[0154] Furthermore, when the paper surface was placed in a freezer and cooled to below -18°C, the print again turned blue, and this discoloration behavior could be reproduced repeatedly.

[0155] Application example 3 (reversible thermochromic indicator) A reversible thermochromic liquid composition (printing ink composition) prepared by dispersing the reversible thermochromic microcapsule pigment prepared in Example 19 in a vehicle containing a binder resin was printed on the surface of a white polyester film (thickness 25 μm) used as a support to form a reversible thermochromic layer, and then a transparent polyester film 16 μm thick was laminated on top of the printed layer to obtain a reversible thermochromic laminate (display body).

[0156] The obtained display was once cooled to -18°C or below to allow the reversible thermochromic layer to completely develop a blue color, and then printed with a thermal transfer printer to form white outline characters. The white outline characters are visible as long as the display is maintained within the temperature range of -18°C to 64°C.

[0157] Furthermore, when the display was cooled again to below -18°C and the reversible thermochromic layer was completely colored blue, the white cut-out letters became invisible, and by forming white cut-out letters using a thermal transfer printer, the display could be used repeatedly.

[0158] Application example 4 (doll) Five parts of the reversible thermochromic microcapsule pigment prepared in Example 20, one part of a dispersant, 94 parts of nylon 12 with a melting point of 180°C, and 0.1 parts of a general pink pigment were melt-mixed in an extruder at 200°C to prepare a reversible thermochromic molding resin composition (pellets) for the core.

[0159] The obtained pellets were fed into an extruder for forming the core, and the nylon 12 natural pellets were fed into an extruder for forming the sheath. Using a composite fiber spinning device, the fibers were spun at 200°C through 18 nozzles so that the core:sheath volume ratio was 6:4, to prepare a reversible thermochromic composite fiber consisting of 18 single fibers with an outer diameter of 90 μm.

[0160] Furthermore, the reversible thermochromic composite fiber was implanted in the head of a doll in a conventional manner to produce a doll with hair made of the reversible thermochromic composite fiber.

[0161] The hair of the resulting doll was cooled to below -18°C, causing it to turn purple. When it was then immersed in hot water above 64°C, it changed from purple to pink. When it was removed from the hot water and cooled below -18°C, it turned purple again. This change could be repeated.

[0162] Application example 5 (electrical cord plug) A reversible thermochromic liquid composition (paint) was prepared by uniformly dispersing 2.5 parts of the reversible thermochromic color-memory microcapsule pigment prepared in Example 21 and 1.5 parts of the non-thermochromic fluorescent pink pigment in an oil-based ink vehicle consisting of 12.5 parts of vinyl chloride-vinyl acetate copolymer resin, 38.3 parts of xylene, 45 parts of butyl acetate, and 0.2 parts of viscosity modifier.

[0163] The resulting paint was cooled to a temperature below -18°C to change color to purple, and then spray-painted onto the plug part (white) of a household electric cord to form a reversible thermochromic layer, thereby obtaining a reversible thermochromic color-memory plug.

[0164] The plugs were purple at room temperature (25°C), but turned pink when heated above 64°C. When cooled from this discolored state, they returned to purple at temperatures below -18°C.

[0165] Once the plug turns pink at temperatures above 65°C, it will maintain that pink discoloration unless it is cooled to a temperature below -18°C. Therefore, it was possible to visually detect the temperature history when the plug became abnormally overheated and reached a high temperature range of 64°C or higher.

[0166] Application example 6 (counterfeit identification mark) A reversible thermochromic liquid composition (printing ink) was prepared by uniformly dispersing 20 parts of the reversible thermochromic microcapsule pigment prepared in Example 23 (previously cooled to -18°C or below to develop a blue color) in an aqueous ink vehicle consisting of 78.0 parts of an acrylic resin emulsion (solid content 40%) and 2.0 parts of an antifoaming agent.

[0167] A counterfeit discrimination mark was printed by gravure printing using the resulting printing ink on gift certificates printed with non-thermochromic ink on high-quality paper. The counterfeit discrimination mark was pink at room temperature (25°C) and did not change color at body temperature or ambient temperature, but became colorless when heated to 64°C or higher and turned blue again when cooled to -18°C or lower.

[0168] The counterfeit discrimination mark remains blue at room temperature and does not change color, making it impossible to identify as a counterfeit discrimination mark. However, it becomes colorless when heated to 64°C or higher, providing an anti-counterfeit function.

[0169] Application Example 7 (Reversible thermochromic prints) A reversible thermochromic liquid composition (offset ink composition) was prepared by mixing 30 parts of the reversible thermochromic microcapsule pigment prepared in Example 27 (previously cooled to -18°C or below to develop a blue color), 5 parts of a red dye, and 65 parts of a linseed oil-based offset ink vehicle.

[0170] The resulting composition was offset printed on both sides of a sheet of wood-free paper as a printing medium, and the resulting composition was dried and cured to form a dated calendar (thermochromic image).

[0171] Next, offset printing was carried out using a non-discoloring black offset ink, which was then dried and hardened to form a frame line (non-discoloring image), thereby producing a reversibly thermochromic printed matter.

[0172] The reversible thermochromic printed material was initially a notebook-style print with purple dates written on it, but by using a friction member to rub the thermochromic image at any point on the surface, the frictional heat generated could cause the material to change color to red.The discolored state could be maintained at room temperature (25°C), making it useful for managing holiday schedules.

[0173] Application example 8 (T-shirt) A reversible thermochromic liquid composition (printing ink composition) was prepared by uniformly dispersing 30 parts of the reversible thermochromic microcapsule pigment prepared in Example 29 (which had been cooled to -18°C or below in advance to develop a blue color) in an aqueous ink vehicle consisting of 60 parts of an acrylic resin emulsion (solid content 45%), 1 part of a viscosity modifier, 0.2 parts of an antifoaming agent, and 8.8 parts of water.

[0174] The ink composition thus obtained was used to screen print a pattern of numerous stars onto a white T-shirt (made of cotton) using a 100-mesh screen to obtain a reversibly thermochromic T-shirt.

[0175] At room temperature (25°C), the T-shirt had numerous blue star patterns visible, and these did not change with body temperature or ambient temperature. However, when heated above 64°C, the star patterns became colorless, and when cooled below -18°C, the blue star patterns were visible again.

[0176] By heating the T-shirt with an iron or other device, the star pattern on the shirt could be partially erased, creating a white pattern by erasing only the desired stars, or by forming letters or patterns using the stars. Furthermore, the discolored state could be maintained at room temperature, and after heating the entire T-shirt to over 64°C to erase the entire star pattern, it was possible to cool it to below -15°C to restore the color of the entire star pattern and form any desired pattern again.

[0177] Application example 9 (solid cursive writing) 40 parts of the reversible thermochromic microcapsule pigment prepared in Example 30 (previously cooled to -18°C or below to develop a blue color), 35 parts of talc (filler), 10 parts of a side-chain crystalline polyolefin (excipient) [manufactured by Toyokuni Oil Mills, product name: HS Crystal 4100], 10 parts of a polyolefin wax (excipient) [manufactured by Sanyo Chemical Industries, Ltd., product name: Sunwax 131-P (softening point 110°C, penetration 3.5)], 2 parts of a styrene-acrylic acid copolymer resin, 2 parts of a polyvinyl alcohol resin, and 1 part of a hindered amine light stabilizer were kneaded in a kneader to prepare a kneaded product for the inner core.

[0178] Next, 69 parts of talc (filler), 10 parts of sucrose fatty acid ester, 10 parts of polyolefin wax (filler), and 10 parts of ethylene-vinyl acetate copolymer were kneaded in a kneader to prepare a kneaded material for the outer shell.

[0179] The kneaded material for the inner core was used as the inner core, the kneaded material for the outer shell was wrapped around the outer periphery, and compression molded in a press to form an outer diameter of φ3 mm and a length of 60 mm (the inner core was φ2 mm, and the outer shell coating thickness was 0.5 mm; dimensions are set values), to produce a solid molded product (solid writing material) for a reversible thermochromic applicator with a core-sheath structure. Note that after compression molding, the solid writing material was cooled to -17°C and returned to room temperature to produce the solid writing material.

[0180] The resulting solid writing body was molded into a round outer shaft (wooden shaft) to obtain a pencil. Furthermore, a cylindrical friction body made of SEBS resin was fixed to the rear end of the pencil via a metal connecting member to produce a solid writing implement with a friction body (a pencil with a friction body).

[0181] When the solid writing implement thus prepared was used to write on paper to form blue letters (handwriting), the handwriting was blue at room temperature (25°C). When the letters were rubbed with a friction member, the letters disappeared and became colorless, and this state could be maintained unless the letters were cooled to -18°C or below.

[0182] Furthermore, when the paper was placed in a freezer and cooled to below -18°C, the letters again turned blue, and this discoloration behavior could be reproduced repeatedly.

[0183] Application example 10 (reversible thermochromic miniature car) A reversible thermochromic liquid composition (spray paint) was obtained by stirring and mixing 15 parts of the reversible thermochromic microcapsule pigment prepared in Example 32 (which had been cooled in advance to -18°C or below to develop a blue color) into a vehicle consisting of 40 parts of a 50% acrylic resin / xylene solution, 20 parts of xylene, 20 parts of methyl isobutyl ketone, and 5 parts of a polyisocyanate-based curing agent.

[0184] The resulting spray paint was sprayed onto the entire body of a white miniature car and dried to form a reversible thermochromic layer, thereby obtaining a reversible thermochromic miniature car (toy). When the miniature car is heated above 64°C, it turns white and remains visible as long as it is kept within the temperature range of -18°C to 64°C.

[0185] Furthermore, when the miniature car was cooled to below -18°C and the reversible thermochromic layer was allowed to fully develop its color, it turned into a blue miniature car that could be used repeatedly. [Explanation of symbols]

[0186] t1 full color temperature t2 color development start temperature t3 decolorization start temperature t4 complete color erasure temperature T1 complete discoloration temperature T2 decolorization start temperature T3 color development temperature T4 full color temperature

Claims

1. (a) an electron-donating color-forming organic compound; (b) an electron-accepting compound; (c) a reaction medium that causes a reversible electron transfer reaction between the components (a) and (b) in a specific temperature range; and A reversible thermochromic microcapsule pigment comprising microcapsules in which a reversible thermochromic composition comprising the compound is encapsulated in a coating, The volume-based average particle diameter (X) of the microcapsules is 0.1 to 5.0 μm, and The cross section of the frozen microcapsule pigment was observed under a transmission electron microscope, and all capsules within the observation field were found to have the following formula: Cut cross-section film thickness = (cross-section outer circumference diameter - cross-section inner circumference diameter) / 2 (In the formula, the outer diameter and inner diameter of the cross section are calculated from the equivalent circle diameters of the area of ​​the region surrounded by the outer periphery of the cross section of the coating and the area of ​​the region surrounded by the inner periphery of the cross section of one microcapsule.) and the average value is taken as the average cross-sectional thickness of the microcapsules, the average cross-sectional thickness of the microcapsules (Y) is 0.02 to 1.0 μm, The reversible thermochromic microcapsule pigment has an average particle size (X) and an average cross-sectional film thickness (Y) that satisfy the following formula: 0.02<Y / X<0.3

2. A reversible thermochromic microcapsule pigment as described in claim 1, wherein the average cross-sectional film thickness (Y) is 0.05 to 0.8 μm.

3. A reversible thermochromic liquid composition comprising the reversible thermochromic microcapsule pigment according to claim 1 or 2 and a vehicle.

4. 4. The reversible thermochromic liquid composition according to claim 3, which is selected from the group consisting of printing ink, stamp ink, paint, ultraviolet curable ink, coloring material, cosmetics, and textile coloring liquid.

5. A reversibly thermochromic solid molding for coating, comprising the reversibly thermochromic microcapsule pigment according to claim 1 or 2 and an excipient.

6. The reversibly thermochromic solid molded article for application according to claim 5, which is a solid writing material or a solid cosmetic.

7. A reversible thermochromic molding resin composition comprising the reversible thermochromic microcapsule pigment according to claim 1 or 2 and a molding resin.

8. A reversibly thermochromic molded article obtained by molding the reversibly thermochromic molding resin composition according to claim 7.

9. A reversible thermochromic laminate comprising a support and a reversible thermochromic layer comprising the reversible thermochromic microcapsule pigment according to claim 1 or 2.

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