Water-based ink composition for reversible thermochromic ballpoint pens, and refills and water-based ballpoint pens containing the same

Abstract

To provide: an aqueous ink composition for a reversible thermochromic ball point pen, which has excellent dry-up resistance performance at a writing tip, exhibits excellent ink dischargeability, and can form good handwriting by suppressing writing defects such as blurring and line skipping; a refill storing the same; and an aqueous ball point pen.SOLUTION: There is provided, an aqueous ink composition for a reversible thermochromic ball point pen comprising at least: a reversible thermochromic microcapsule pigment including a reversible thermochromic composition comprising at least (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium which controls a color reaction of the (a) and (b) components; an N-vinyl-2-pyrrolidone polymer having a mass average molecular weight of 3,000 to 2,000,000, and (c) a thixotropy-imparting agent; and water. Also there are provided a refill storing the same and an aqueous ball point pen.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a reversibly thermochromic water-based ink composition for a ballpoint pen, a refill containing the same, and a water-based ballpoint pen. More specifically, the present invention relates to a reversibly thermochromic water-based ink composition for a ballpoint pen that can suppress drying at the writing tip of the ballpoint pen and produce good handwriting, and a refill and water-based ballpoint pen containing the same. [Background technology]

[0002] Conventionally, a writing instrument (reversible thermochromic ballpoint pen) containing a reversible thermochromic aqueous ink composition has been proposed, which can produce handwriting that can alternately store and retain the state before and after color change within a certain temperature range, such as room temperature (see, for example, Patent Document 1). The above-mentioned writing instruments contain a reversible thermochromic microencapsulated pigment as a colorant in an aqueous ink composition, but because the reversible thermochromic composition, which is the colorant, is encapsulated in microcapsules, it tends to be difficult to achieve high writing density compared to other writing instruments in which the colorant is not encapsulated in microcapsules. Increasing the blending ratio of the microencapsulated pigment is considered to increase the writing density, but increasing the blending ratio tends to make the ink composition more likely to dry out at the writing tip, which tends to result in writing defects such as smearing and skipped lines. In order to improve the resistance to dry-up at the writing tip, aqueous ink compositions for ballpoint pens have been disclosed in which sugar alcohols or specific ester compounds are blended into the aqueous ink composition (see, for example, Patent Documents 2 and 3). However, because the colorants used in reversible thermochromic aqueous ink compositions are relatively special, it tends to be difficult to obtain excellent properties even if the above-mentioned sugar alcohols or specific ester compounds used in general ink compositions are adopted, and furthermore, in order to fully exhibit the dry-up resistance performance, it is necessary to blend a large amount, which increases the viscosity of the ink and can cause poor writing. [Prior art documents] [Patent documents]

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention aims to provide an aqueous ink composition for a reversible thermochromic ballpoint pen that has excellent dry-up resistance performance at the tip of the pen and exhibits good ink ejection properties, as well as a refill containing the same and an aqueous ballpoint pen.

Means for Solving the Problems

[0005] The present invention includes at least a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color-forming reaction of the components (a) and (b), an N-vinyl-2-pyrrolidone polymer having a mass average molecular weight of 3,000 to 2,000,000, Saccharoglycan and water, and is an aqueous ink composition for a reversible thermochromic ballpoint pen. wherein P is the content ratio of the N-vinyl-2-pyrrolidone polymer with respect to the total mass of the ink composition PVP and P is the content ratio of the reversible thermochromic microcapsule pigment with respect to the total mass of the ink composition MC when P PVP ]> and P MC satisfy 3.5 ≦ P MC / P PVP ≦ 40, an aqueous ink composition for a reversible thermochromic ballpoint pen is required. Furthermore, P PVP is 0.1 to 10% by mass, and further contains a phosphate ester surfactant having an HLB value of 9 to 18. further comprising a polyoxyalkylene aryl ether phosphate is required. Furthermore, a refill containing the aqueous ink composition for the reversible thermochromic ballpoint pen is required to have a ball diameter of 0.2 to 0.4 mm provided at the writing tip of the refill. Furthermore, an aqueous ballpoint pen formed by housing the refill in a shaft cylinder is required to further include a retracting mechanism, and to include a friction member that discolors the writing by the aqueous ballpoint pen with frictional heat.

Advantages of the Invention

[0006] The present invention can provide an aqueous ink composition for a reversible thermochromic ballpoint pen that has excellent dry-up resistance performance at the writing tip, exhibits excellent ink ejection properties, suppresses writing defects such as feathering and skipping, and can form good handwriting, as well as a refill and an aqueous ballpoint pen containing the same.

Brief Description of the Drawings

[0007] [Fig. 1] It is a graph explaining the hysteresis characteristics in the color density - temperature curve of a heat - decoloring type reversible thermochromic composition. [Fig. 2] It is a graph explaining the hysteresis characteristics in the color density - temperature curve of a heat - decoloring type reversible thermochromic composition having color memory properties.

Embodiments for Carrying Out the Invention

[0008] The aqueous ink composition for a reversible thermochromic ballpoint pen according to the present invention (hereinafter, may be referred to as "aqueous ink composition", "ink composition", or "ink") comprises at least a reversible thermochromic microcapsule pigment, an N - vinyl - 2 - pyrrolidone polymer having a mass average molecular weight of 3,000 to 2,000,000, a shear - thinning viscosity - imparting agent, and water. Each component constituting the aqueous ink composition according to the present invention will be described below.

[0009] The ink composition according to the present invention contains, as a colorant, a reversible thermochromic microcapsule pigment (hereinafter sometimes referred to as "microcapsule pigment" or "pigment") encapsulating a reversible thermochromic composition. The reversible thermochromic composition comprises (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color-forming reaction of the above components (a) and (b) occurs. As the reversible thermochromic composition, those described in Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, Japanese Patent Publication No. 1-29398, etc., change color before and after a predetermined temperature (color change point), exhibit a decolorized state in a temperature range equal to or higher than the high-temperature-side color change point, and a colored state in a temperature range equal to or lower than the low-temperature-side color change point. Among the two states, only a specific one of the states exists at room temperature, and the other state is maintained while the heat or cold applied to cause the state to appear is being applied, but returns to the state presented at room temperature when the application of heat or cold stops. A heating-decoloring type (decolorizes by heating and colors by cooling) reversible thermochromic composition having a relatively small hysteresis width (ΔH) (ΔH = 1 to 7°C) can be used (see Figure 1).

[0010] Also, a reversible thermochromic composition having a large hysteresis width (ΔH = 8 to 70°C) described in Japanese Patent Publication No. 4-17154, Japanese Unexamined Patent Application Publication No. 7-179777, Japanese Unexamined Patent Application Publication No. 7-33997, Japanese Unexamined Patent Application Publication No. 8-39936, Japanese Unexamined Patent Application Publication No. 2005-1369, etc., shows that the shape of the curve plotting the change in color density due to temperature change varies greatly depending on whether the temperature is increased from the low-temperature side of the color change temperature range or decreased from the high-temperature side of the color change temperature range. The colored state in a temperature range equal to or lower than the complete coloration temperature t1 or the decolorized state in a high-temperature range equal to or higher than the complete decolorization temperature t4 has color memory in a specific temperature range (temperature range between the coloration start temperature t2 and the decolorization start temperature t3 (substantially two-phase holding temperature range)). A heating-decoloring type (decolorizes by heating and colors by cooling) reversible thermochromic composition can also be used (see Figure 2).

[0011] Specifically, as a reversible thermochromic composition having color memory, the complete color development temperature t1 is a temperature that can only be obtained in a freezer, a cold region, etc., that is, -50 to 0 °C, preferably -40 to -5 °C, more preferably -30 to -10 °C, and the complete color fading temperature t4 is a temperature obtained from frictional heat by a friction body, a common heating tool such as a hair dryer, that is, 45 to 95 °C, preferably 50 to 90 °C, more preferably 60 to 80 °C. By specifying ΔH to be 40 to 100 °C, it can function effectively to maintain the color exhibited in the normal state (daily living temperature range).

[0012] The following specifically explains each component (a), (b), and (c).

[0013] Component (a), that is, an electron-donating color-forming organic compound, is a component that determines color and is a compound that donates electrons to component (b), which is a developer, and develops color.

[0014] Examples of the electron-donating color-forming organic compound include phthalide compounds, fluoran compounds, styrylnquinoline compounds, diazarodamine lactone compounds, pyridine compounds, quinazoline compounds, and bisquinazoline compounds. Among these, phthalide compounds and fluoran compounds are preferred. Examples of the phthalide compound include diphenylmethane phthalide compounds, phenylindolyl phthalide compounds, indolyl phthalide compounds, diphenylmethane azaphthalide compounds, phenylindolyl azaphthalide compounds, and their derivatives. Among these, phenylindolyl azaphthalide compounds and their derivatives are preferred. Examples of the fluoran compound include aminofluoran compounds, alkoxyfluoran compounds, and their derivatives.

[0015] The following exemplifies the compounds that can be used for component (a). 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-N-p-tolylamino)fluoran, 3,6-dimethoxyfluoran, 3,6-di-n-butoxyfluoran, 2-methyl-6-(N-ethyl-N-p-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-N-p-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-Xylylino-3-methyl-6-diethylaminofluoran, 2-Anilino-3-methyl-6-(N-ethyl-N-p-tolylamino)fluoran, 6-Diethylamino-1,2-benzofluorane, 6-(N-Ethyl-N-isobutylamino)-1,2-benzofluorane, 6-(N-Ethyl-N-isopentylamino)-1,2-benzofluorane, 2-(3-Methoxy-4-dodecoxystyryl)quinoline, 2-Diethylamino-8-diethylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidine-5,1′(3′H)-isobenzofuran]-3′-one, 2-Di-n-butylamino-8-di-n-butylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidine-5,1′(3′H)-isobenzofuran]-3′-one, 2-Di-n-butylamino-8-diethylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidine-5,1′(3′H)-isobenzofuran]-3′-one, 2-Di-n-butylamino-8-(N-ethyl-N-isoamylamino)-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidine-5,1′(3′H)-isobenzofuran]-3′-one, 2-Di-n-butylamino-8-di-n-pentylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidine-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〕

[0016] In addition, as fluorans, in addition to compounds having a substituent on the phenyl group forming the xanthene ring, 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, a halogen atom such as a chlorine atom) on the phenyl group forming the lactone ring and exhibit blue or black color may also be used.

[0017] (B) component, that is, the electron-accepting compound, receives electrons from the (A) component and functions as a color former for the (A) component. 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 the (A) component to develop color], and the group of compounds having an electron hole. Among the above (B) components, compounds selected from the group of compounds having an active proton are preferred.

[0018] Examples of the group of compounds having an active proton include compounds having a phenolic hydroxyl group and their derivatives, carboxylic acids and their derivatives, acidic phosphoric esters and their derivatives, azoazole compounds and their derivatives, 1,2,3-triazoles and their derivatives, cyclic carbosulfimides, halohydrins having 2 to 5 carbon atoms, sulfonic acids and their derivatives, and inorganic acids. As the carboxylic acid and its derivatives, aromatic carboxylic acids and their derivatives, or aliphatic carboxylic acids having 2 to 5 carbon atoms and their derivatives are preferred. Examples of the group of pseudo-acidic compounds include metal salts of compounds having a phenolic hydroxyl group, metal salts of carboxylic acids, metal salts of acidic phosphoric esters, metal salts of sulfonic acids, aromatic carboxylic anhydrides, aliphatic carboxylic anhydrides, mixed anhydrides of aromatic carboxylic acids and sulfonic acids, cycloolefin dicarboxylic anhydrides, urea and its derivatives, thiourea and its derivatives, guanidine and its derivatives, and halogenated alcohols. Examples of the group of compounds having an electron hole include borates, boric acid esters, and inorganic salts.

[0019] Among the above-mentioned component (b), a compound having a phenolic hydroxyl group is preferable because it can more effectively exhibit thermochromic properties. Compounds having a phenolic hydroxyl group widely include compounds from monophenol compounds to polyphenol compounds. Further, bisphenol compounds, tris-phenol compounds, phenol-aldehyde condensation resins, etc. are also included therein. The compound having a phenolic hydroxyl group preferably has at least two benzene rings. Further, the compound having a phenolic hydroxyl group may have substituents such as an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carboxy group and its ester or amide group, and a halogen atom.

[0020] Examples of the metal contained in the metal salt such as the compound having a phenolic hydroxyl group include sodium, potassium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, and molybdenum.

[0021] Compounds of the component (b) are exemplified below. Examples of the compound 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, 2-Heptadecafluorooctylethane 4-hydroxybenzoate, Benzyl 4-hydroxybenzoate, Benzyl ester of 4-hydroxybenzoic acid, 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, o-Methylphenylethyl 4-hydroxybenzoate, m-Methylphenylethyl 4-hydroxybenzoate, p-Methylphenylethyl 4-hydroxybenzoate, p-Ethylphenylethyl 4-hydroxybenzoate, p-Propylphenylethyl 4-hydroxybenzoate, p-tert-Butylphenylethyl 4-hydroxybenzoate etc. can be exemplified.

[0022] Examples of the compound having two phenolic hydroxyl groups include, for example, Resorcinol, 2-Methylresorcinol, 4-n-Hexylresorcinol, 4-n-Octylresorcinol, 4-tert-Octylresorcinol, 4-Benzoylresorcinol, 4-Nitroresorcinol, Methyl β-resorcylate, Benzyl β-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 etc. can be exemplified.

[0023] Furthermore, as bisphenol compounds, for example, 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)ethylpropionate, 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-Ethylenedioxydiphenol, 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′-hydroxydiphenyl 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'-{Oxydibis(ethyleneoxide-p-phenylenesulfonyl)}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 etc. can be exemplified.

[0024] Examples of the compound having 3 phenolic hydroxyl groups include, for example, pyrogallol, phloroglucinol, phloroglucinol carboxylic acid, gallic acid, octyl gallate, dodecyl gallate, etc.

[0025] Furthermore, examples of the trisphenol compound include, for example, 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″-ethylidynetris(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-hydroxysylylphenyl)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-hydroxyphenyloctane, 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-hydroxyphenyloctane, 1,4,4-Tris(4-hydroxyphenyl)nonane, 1,4,4-Tris(4-hydroxyphenyldecane, 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) etc. can be exemplified.

[0026] Examples of the compound having 4 or more phenolic hydroxyl groups include, for example, 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(methylidene)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″-Ethylidene tris{[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″-ethylidene tris[2,6-bis(2-hydroxybenzyl)phenol], 4,4′,4″-ethylidene tris[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 etc. can be exemplified.

[0027] Examples of the carboxylic acid and its derivatives include, for example, 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-toluenesulfonyl)propyloxy]salicylic acid, 5-[p-(2-p-methoxyphenoxyethoxy)cumyl]salicylic acid, 4-octyloxycarbonylaminosalicylic acid, 3,5-distyrated 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-(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 etc. can be exemplified.

[0028] Examples of the 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, bis(2-ethylhexyl) phosphate, etc.

[0029] (b) As the component, a compound having a phenolic hydroxyl group is preferable because the thermochromic characteristics can be more effectively exhibited. However, aromatic carboxylic acids, aliphatic carboxylic acids having 2 to 5 carbon atoms, metal salts of carboxylic acids, acidic phosphate esters and their metal salts, and compounds selected from 1,2,3-triazoles and their derivatives may also be used.

[0030] (a) The (c) component of the reaction medium that reversibly causes an electron transfer reaction between the (a) component and the (b) component in a specific temperature range will be described. (c) Examples of the (c) component include alcohols, esters, ketones, ethers, and acid amides. When the reversible thermochromic composition of the present invention is applied to microencapsulation and secondary processing, low molecular weight compounds will evaporate outside the capsules when subjected to high heat treatment. Therefore, compounds having 10 or more carbon atoms are preferably used to stably retain them inside the capsules.

[0031] 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, docosyl alcohol and the like.

[0032] As esters, esters having 10 or more carbon atoms are effective, and 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, and 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. Examples include ethyl caprylate, octyl caprylate, stearyl caprylate, myristyl capric acid, docosyl capric acid, 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, n-undecyl stearate, 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, dicitrate oxalate, dicitrate malonate, dilauryl succinate, dilauryl glutarate, diundecyl adipate, dilauryl azelate, di-(n-nonyl) sebacate, di-neopentyl 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, etc.

[0033] In addition, esters of saturated fatty acids and branched aliphatic alcohols, esters of unsaturated fatty acids or saturated fatty acids having a branch or a substituent and aliphatic alcohols that are branched or have 16 or more carbon atoms, and ester compounds selected from cetyl butyrate, stearyl butyrate, and behenyl butyrate are also effective. Examples of the above ester compounds include 2-ethylhexyl butyrate, 2-ethylhexyl behenate, 2-ethylhexyl myristate, 2-ethylhexyl caprinate, 3,5,5-trimethylhexyl laurate, 3,5,5-trimethylhexyl palmitate, 3,5,5-trimethylhexyl stearate, 2-methylbutyl caproate, 2-methylbutyl caprylate, 2-methylbutyl capric acid, 1-ethylpropyl palmitate, 1-ethylpropyl stearate, 1-ethylpropyl behenate, 1-ethylhexyl laurate, 1-ethylhexyl myristate, 1-ethylhexyl palmitate, 2-methylpentyl caproate, 2-methylpentyl caprylate, 2-methylpentyl capric acid, 2-methylpentyl laurate, 2-methylbutyl stearate, 2-methylbutyl stearate, 3-methylbutyl stearate, 1-methylheptyl stearate, 2-methylbutyl behenate, 3-methylbutyl behenate, 1-methylheptyl behenate, 1-methylheptyl behenate, 1-ethylpentyl caproate, 1-ethylpentyl palmitate, 1-methylpropyl stearate, 1-methyloctyl stearate, 1-methylhexyl stearate, 1,1-dimethylpropyl laurate, 1-methylpentyl capric acid, 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-dimethyloctyl behenate, 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, behenyl butyrate, etc.

[0034] Furthermore, in order to change color while showing large hysteresis characteristics with respect to the color density-temperature curve and impart color memory depending on temperature change, a carboxylic acid ester compound showing a ΔT value (melting point - cloud point) of 5°C or more and less than 50°C described in Japanese Patent Publication No. 4-17154 can be exemplified. For example, a carboxylic acid ester containing a substituted aromatic ring in the molecule, an ester of a carboxylic acid containing an unsubstituted aromatic ring and an aliphatic alcohol having 10 or more carbon atoms, a carboxylic acid ester containing a cyclohexyl group in the molecule, an ester of a fatty acid having 6 or more carbon atoms and an unsubstituted aromatic alcohol or phenol, an ester of a fatty acid having 8 or more carbon atoms and a branched aliphatic alcohol, an ester of a dicarboxylic acid and an aromatic alcohol or a branched aliphatic alcohol, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, dimyristin, distearin, etc.

[0035] In addition, a fatty acid ester compound obtained from an odd-numbered aliphatic monohydric alcohol having 9 or more carbon atoms and an aliphatic carboxylic acid having an even number of carbon atoms, and a fatty acid ester compound having a total carbon number of 17 to 23 obtained from n-pentyl alcohol or n-heptyl alcohol and an even-numbered aliphatic carboxylic acid having 10 to 16 carbon atoms are also effective. Examples of the above 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 capric acid, n-nonyl capric acid, n-undecyl capric acid, n-tridecyl capric acid, n-pentadecyl capric acid, n-pentyl laurate, n-heptyl laurate, n-nonyl laurate, n-undecyl laurate, n-tridecyl laurate, n-pentadecyl laurate, n-pentyl myristate, 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-undecyl eicosanoate, n-tridecyl eicosanoate, n-pentadecyl eicosanoate, n-nonyl behenate, n-undecyl behenate, n-tridecyl behenate, n-pentadecyl behenate, and the like.

[0036] As the ketones, aliphatic ketones having 10 or more carbon atoms in total are effective. 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-henicosanone, 2-docosanone, laurolone, stearolone, and the like. Furthermore, arylalkyl ketones having a total carbon number of 12 to 24 can be exemplified, such as n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradecanophenone, 4-n-dodecylacetophenone, n-tridecanophenone, 4-n-undecylacetophenone, n-laurophenone, 4-n-decylacetophenone, n-undecanophenone, 4-n-nonylacetophenone, n-decanophenone, 4-n-octylacetophenone, n-nonanophenone, 4-n-heptylacetophenone, n-octanophenone, 4-n-hexylacetophenone, 4-n-cyclohexylacetophenone, 4-tert-butylpropiophenone, n-heptaphenone, 4-n-pentylacetophenone, cyclohexylphenyl ketone, benzyl-n-butyl ketone, 4-n-butylacetophenone, n-hexanophenone, 4-isobutylacetophenone, 1-acetonaphthone, 2-acetonaphthone, cyclopentylphenyl ketone, etc.

[0037] As the ethers, aliphatic ethers having a total carbon number of 10 or more 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, undecanediol diethyl ether, etc.

[0038] Examples of acid amides include acetamide, propionamide, butyramide, caproamide, caprylamide, capric amide, lauric amide, myristic amide, palmitic amide, stearic amide, behenic amide, oleic amide, erucic amide, benzamide, caproanilide, caprylanilide, capric anilide, laurylanilide, myristylanilide, palmitylanilide, stearylanilide, behenylanilide, oleylanilide, erucylanilide, N-methylcaproamide, N-methylcaprylamide, N-methylcapric amide, N-methyllauramide, N-methylmyristamide, N-methylpalmitamide, N-methylstearamide, N-methylbehenamide, N-methyloleamide, N-methylierucamide, N-ethyllauramide, N-ethylmyristamide, N-ethylpalmitamide, N-ethylstearamide, N-ethyloleamide, N-butyllauramide, N-butylmyristamide, N-butylpalmitamide, N-butylstearamide, N-butyloleamide, N-octyllauramide, N-octylmyristamide, N-octylpalmitamide, N-octylstearamide, N-octyloleamide, N-dodecyllauramide, N-dodecylmyristamide, N-dodecylpalmitamide, N-dodecylstearamide, N-dodecyloleamide, dilauric amide, dimyristic amide, dipalmitic amide, distearic amide, dioleic amide, trilauric amide, trimyristic amide, tripalmitic amide, tristearic amide, trioleic amide, succinamide, adipamide, glutaramide, malonamide, azelaic amide, maleic amide, N-methylsuccinamide, N-methyladipamide, N-methylglutaramide, N-methylmalonamide, N-methylazelaic amide, N-ethylsuccinamide, N-ethyladipamide, N-ethylglutaramide, N-ethylmalonamide, N-ethylazelaic amide, N-butylsuccinamide,Examples thereof include N-butyl adipamide, N-butyl glutarate, N-butyl malonate, N-octyl adipamide, N-dodecyl adipamide, etc.

[0039] Also, the component (C) may be a compound represented by the following formula (1). [Chemical formula] [In the formula, R1 represents a hydrogen atom or a methyl group, m represents an integer of 0 to 2, either one of X1 and X2 is -(CH2) n OCOR2 or (CH2) n COOR2, the other represents a hydrogen atom, n represents an integer of 0 to 2, R2 represents an alkyl group 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.] Among the compounds represented by formula (1), when R1 is a hydrogen atom, a reversible thermochromic composition having a wider hysteresis width can be obtained, which is preferable. Furthermore, it is more preferable that R1 is a hydrogen atom and m is 0. Among the compounds represented by formula (1), more preferably, it is a compound represented by the following formula (2). [Chemical formula] (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) Examples of the compound represented by the 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, 4-benzyloxyphenylethyl octadecanoate, and the like.

[0040] Furthermore, the component (c) may be a compound represented by the following formula (3).

Chemical formula

[0041] Furthermore, the component (c) may be a compound represented by the following formula (4).

Chemical formula

[0042] Furthermore, the component (C) may be a compound represented by the following formula (5).

Chemical formula

[0043] Furthermore, the component (c) may be a compound represented by the following formula (6). [Chemical formula] (In the formula, X represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom; m represents an integer of 1 to 3; and n represents an integer of 1 to 20) Examples of the compound represented by the formula (6) include, for example, diesters of succinic acid and 2-phenoxyethanol, diesters of suberic acid and 2-phenoxyethanol, diesters of sebacic acid and 2-phenoxyethanol, diesters of 1,10-decanedicarboxylic acid and 2-phenoxyethanol, diesters of 1,18-octadecanedicarboxylic acid and 2-phenoxyethanol, and the like.

[0044] Furthermore, the component (c) may be a compound represented by the following formula (7). [Chemical Formula] (In the formula, R represents any one of an alkyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, a cycloalkyl group, and an alkenyl group having 4 to 22 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 4 carbon atoms, and a halogen atom; n represents 0 or 1) 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 the like.

[0045] Furthermore, the component (c) may be a compound represented by the following formula (8). [Chemical Formula] (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 any one of a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, and a halogen atom; Y represents a hydrogen atom or a methyl group; Z represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, and a halogen atom) Examples of the compound represented by formula (8) include phenoxyethyl 4-butoxybenzoate, phenoxyethyl 4-pentyloxybenzoate, phenoxyethyl 4-tetradecyloxybenzoate, the ester of phenoxyethyl 4-hydroxybenzoate and dodecanoic acid, the dodecyl ether of phenoxyethyl vanillate, and the like.

[0046] Furthermore, the component (c) may be a compound represented by the following formula (9). [Chemical Formula] (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) Examples of the compound represented by formula (9) include benzoic acid esters of octyl 4-hydroxybenzoate, decyl 4-hydroxybenzoate, heptyl 4-hydroxybenzoate 4-methoxybenzoate, dodecyl 4-hydroxybenzoate 2-methoxybenzoate, benzoic acid esters of cyclohexylmethyl 4-hydroxybenzoate, and the like.

[0047] Furthermore, the component (c) may be a compound represented by the following formula (10). [Chemical Formula] (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; 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) Examples of the compound represented by formula (10) include phenoxyethyl ethers of nonyl 4-hydroxybenzoate, decyl 4-hydroxybenzoate, undecyl 4-hydroxybenzoate, dodecyl vanillate, and the like.

[0048] Furthermore, the component (c) may be a compound represented by the following formula (11). [Chemistry] (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.) Examples of the compound represented by formula (11) include diesters of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanecarboxylic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid, diesters of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid, and the like.

[0049] Furthermore, the component (c) may be a compound represented by the following formula (12). [Chemistry] (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.) Examples of the compound represented by formula (12) include diesters of 4-phenylphenol ethylene glycol ether and cyclohexanecarboxylic acid, diesters of 4-phenylphenol diethylene glycol ether and lauric acid, diesters of 4-phenylphenol triethylene glycol ether and cyclohexanecarboxylic acid, diesters of 4-phenylphenol ethylene glycol ether and octanoic acid, diesters of 4-phenylphenol ethylene glycol ether and nonanoic acid, diesters of 4-phenylphenol ethylene glycol ether and decanoic acid, diesters of 4-phenylphenol ethylene glycol ether and myristic acid, and the like.

[0050] The above-mentioned reversible thermochromic composition is a solid solution having the above components (a), (b), and (c) as essential components. The ratio of each component depends on the concentration, discoloration temperature, discoloration form, and type of each component. Generally, the component ratio that can obtain desired properties is as follows: with respect to 1 part by mass of component (a), component (b) is 0.1 to 100, preferably 0.1 to 50, more preferably 0.5 to 20, and component (c) is 5 to 200, preferably 5 to 100, more preferably 10 to 100 (all of the above ratios are in parts by mass).

[0051] Furthermore, various light stabilizers may be blended into the reversible thermochromic composition as needed. The light stabilizer is contained to prevent photo-degradation of the reversible thermochromic composition composed of components (a), (b), and (c), and is blended at a ratio of 0.3 to 24% by mass, preferably 0.3 to 16% by mass, with respect to 1% by mass of component (a). Among the light stabilizers, the ultraviolet absorber effectively cuts off ultraviolet rays contained in sunlight, etc., and prevents photo-degradation caused by the excited state due to the photoreaction of component (a). In addition, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers, etc. suppress oxidation reactions by light. The light stabilizer can be used alone or in combination of two or more.

[0052] By encapsulating the above-mentioned reversible thermochromic composition in microcapsules to form a reversible thermochromic microcapsule pigment, a chemically and physically stable pigment can be constituted. Furthermore, under various usage conditions, the reversible thermochromic composition is maintained at the same composition and exhibits the same action and effect. The microencapsulation of the microcapsule pigment includes conventionally known methods such as isocyanate-based interfacial polymerization method, in Situ polymerization methods such as melamine-formalin-based methods, in-liquid curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent, melt dispersion cooling method, air suspension coating method, spray drying method, etc., which are appropriately selected according to the application. Examples of the capsule material include epoxy resin, urea resin, urethane resin, isocyanate resin, etc. Furthermore, a secondary resin film can be further provided on the surface of the microcapsules according to the purpose to impart durability or modify the surface characteristics for practical use. The mass ratio of the inclusion to the wall film of the reversible thermochromic microcapsule pigment is preferably 7:1 to 1:1. When the mass ratio of the inclusion to the wall film is within the above range, a decrease in color density and vividness during color development is prevented. More preferably, the mass ratio of the inclusion to the wall film is 6:1 to 1:1. When the ratio of the inclusion to the wall film exceeds the above range, the thickness of the wall film of the microcapsule pigment becomes thin, and it is easily broken by heat or pressure. On the other hand, when the ratio of the wall film to the inclusion exceeds the above range, the color density and vividness during color development tend to decrease.

[0053] In addition, by incorporating a non-thermochromic colorant such as a general dye or pigment into the microcapsule pigment, it exhibits a color change behavior from colored (1) to colored (2).

[0054] The average particle diameter of the microcapsule pigment is preferably in the range of 0.01 to 5 μm, more preferably 0.05 to 4 μm, still more preferably 0.1 to 3 μm, and particularly preferably 0.5 to 3 μm. When the average particle diameter of the microcapsule pigment exceeds 5 μm, it becomes difficult to obtain good ink ejection performance when used in a writing instrument. On the other hand, when the average particle diameter is less than 0.01 μm, it becomes difficult to exhibit high-concentration color development. The measurement of the average particle diameter is as follows: The particle area is determined using image analysis type particle size distribution measurement software [manufactured by Mountech Co., Ltd., product name: MacView], and the equivalent diameter of the projected area circle (Heywood diameter) is calculated from the area of the particle area, and the measured value is the average particle diameter of the particles equivalent to an equal-volume sphere based on this value. When the particle diameter of all particles or most particles exceeds 0.2 μm, it is also possible to measure the average particle diameter of the particles equivalent to an equal-volume sphere by the Coulter method using a particle size distribution measuring device [manufactured by Beckman Coulter, Inc., product name: Multisizer 4e]. Furthermore, based on the numerical values measured using the above software or measuring apparatus by the Coulter method, the volume-based particle size and average particle size may be measured with a laser diffraction / scattering type particle size distribution measuring apparatus [manufactured by Horiba, Ltd., product name: LA-300] that has been calibrated.

[0055] In the present invention, the content rate of the reversible thermochromic microcapsule pigment with respect to the total mass of the ink composition (hereinafter sometimes referred to as "P" MC ") is 5 to 40% by mass, preferably 10 to 40% by mass, more preferably in the range of 15 to 35% by mass. When the content rate of the microcapsule pigment exceeds 40% by mass, the viscosity of the ink composition tends to increase, the ink ejection property of the ballpoint pen containing the ink composition deteriorates, and the writing performance is likely to be inhibited. On the other hand, when the content rate is less than 5% by mass, it is difficult to obtain suitable discoloration properties and suitable writing density as a ballpoint pen, and it becomes difficult to sufficiently satisfy the discoloration function. Generally, when an ink composition is used for applications such as ballpoint pens, the blending amount of the colorant is less than 10% by mass with respect to the total mass of the ink composition. However, when a microcapsule pigment is applied as the colorant, it is preferable to increase the blending amount of the pigment in order to achieve a sufficient color density. And when the blending amount of the pigment is increased, the ratio of the solid content (solid content rate) of the ink composition becomes high, and it tends to dry easily at the writing tip portion, and the dry-up resistance performance is inferior. However, the ink composition according to the present invention is excellent in dry-up resistance performance by containing an N-vinyl-2-pyrrolidone polymer described later, and has a high content rate of the microcapsule pigment in the ink composition. In particular, even when the ink composition contains 18% by mass or more of the microcapsule pigment with respect to the total mass of the ink composition, drying at the writing tip portion can be suppressed and good handwriting can be formed.

[0056] The ink composition according to the present invention further comprises an N-vinyl-2-pyrrolidone polymer (hereinafter sometimes referred to as "PVP"). PVP has the effect of simultaneously achieving various properties. Specifically, it has the effect of adjusting the viscosity of the ink composition, the effect of suppressing the aggregation of microcapsule pigments, the effect of improving the fixing property and adhesiveness of the ink components to paper, and the like. Further, in an ink composition containing microcapsule pigments, it has the effect of improving the dry-up resistance performance. For example, when the ink composition is used in a ballpoint pen, particularly a retractable ballpoint pen, the writing tip (pen tip) is placed in an environment where it is likely to dry, so writing defects such as scratching and skipping are likely to occur, and writing may become impossible. The state where the pen tip is dry is called dry-up. However, an ink composition using a specific PVP can suppress dry-up and achieve excellent writing performance.

[0057] The PVP applied to the present invention is a polymer obtained by polymerizing N-vinyl-2-pyrrolidone, and its mass average molecular weight is 3,000 to 2 million. The mass average molecular weight is preferably in the range of 3,000 to 1.7 million, more preferably 3,000 to 1 million. When the mass average molecular weight of PVP is within the above range, when a medium such as water in the ink composition volatilizes, an increase in the viscosity of the ink composition and the aggregation of microcapsule pigments are suppressed, and it becomes easy to obtain an ink composition having excellent dry-up resistance performance. PVP is not particularly limited as long as its mass average molecular weight is in the range of 3,000 to 2 million, and it can be produced by a known polymerization method. Examples of the polymerization method include, for example, a method of polymerizing N-vinyl-2-pyrrolidone in the presence of an initiator. In addition, commercially available products can also be used as PVP. Specifically, products manufactured by BASF, product names: Sokalan K17P (weight average molecular weight: 9,000), K30P (weight average molecular weight: 50,000), K80P (weight average molecular weight: 850,000), K85P (weight average molecular weight: 1.1 million), K90P (weight average molecular weight: 1.4 million); products manufactured by ASHLAND, product names: PVP K-12 (weight average molecular weight: 4,000 - 6,000), K-15 (weight average molecular weight: 6,000 - 15,000), K-30 (weight average molecular weight: 40,000 - 80,000), K-60 (weight average molecular weight: 390,000 - 470,000), K-85 (weight average molecular weight: 900,000 - 1.2 million), K-90 (weight average molecular weight: 1 million - 1.7 million); products manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product names: Pitts Cole K-17 (weight average molecular weight: 9,000), K-30 (weight average molecular weight: 45,000), K-30A (weight average molecular weight: 45,000), K-50 (weight average molecular weight: 250,000), K-80 (weight average molecular weight: 900,000), K-85 (weight average molecular weight: 1 million), K-90 (weight average molecular weight: 1.2 million), etc. can be exemplified. The weight average molecular weight can be calculated by GPC (gel permeation chromatography) in accordance with JIS K7252-1.

[0058] In the present invention, the content of PVP (hereinafter sometimes referred to as "P" PVP ) with respect to the total mass of the ink composition is preferably in the range of 0.1 - 10% by mass, more preferably 0.5 - 6.5% by mass. When the content of PVP is within the above range, excellent dry-up resistance performance can be obtained, the ink ejection property from the pen tip can be kept good, and a high handwriting density can be achieved.

[0059] In the present invention, the content of the microcapsule pigment (P MC ), and the content of PVP (P PVP ) preferably satisfy the following formula (13). 3 ≤ P MC / P PVP ≤ 60 (13) PMC / P PVP Regarding / P, more preferably 3.5 ≤ P MC / P PVP ≤ 40 is satisfied. P MC / P PVP When the / P is within the above range, even when using a microcapsule pigment as a colorant in the ink composition, it becomes easy to obtain an ink composition excellent in dry-up resistance performance and writing performance. Generally, when using an ink composition for applications such as ballpoint pens, the blending amount of the colorant is less than 10% by mass based on the total mass of the ink composition. However, when using a microcapsule pigment as the colorant, it is preferable to increase the blending amount to achieve sufficient color development. And generally, an ink composition with a large blending amount of microcapsule pigment has a higher ratio of solid content (solid content rate) in the ink composition compared to general inks, so it is likely to have inferior dry-up resistance performance. However, in the present invention, such a problem can be solved by blending the microcapsule pigment and PVP in a specific ratio.

[0060] The ink composition according to the present invention further comprises a shear thinning viscosity imparting agent. Shear thinning viscosity means a property that has a high viscosity when standing still and the viscosity decreases when a shear stress is applied. Some ballpoint pens contain an ink composition generally called gel ink. Since gel ink has a high viscosity when standing still without applying a shear stress, it is stably held in the ballpoint pen. When writing, due to the high shear stress generated by the high-speed rotation of the ball, the ink near the ball has its viscosity reduced. As a result, the ink is discharged from the gap between the ball and the ball housing portion and adheres to the non-writing surface. By including a shear thinning viscosity imparting agent in the ink composition, the reversible thermochromic ink composition can be made into a gel ink. In addition, the gel ink can suppress the aggregation and sedimentation of the microcapsule pigments and can also suppress the bleeding of the handwriting, so that good handwriting can be formed. Furthermore, a ballpoint pen containing the gel ink can prevent ink leakage from the gap between the ball and the tip when not in use, and can also prevent the backflow of the ink when the writing tip is left facing upward (upright state).

[0061] Examples of the shear-thinning viscosity-imparting agent include water-soluble polysaccharides, polymers having a molecular weight of 100,000 to 150,000 and mainly composed of alkyl esters of methacrylic acid, poly-N-vinyl-carboxylic acid amide cross-linked products, benzylidene sorbitol and benzylidene xylitol or their derivatives, alkali-thickening type acrylic resins, crosslinkable acrylic acid polymers, inorganic fine particles, metal salts and amine salts of dialkyl sulfosuccinic acid, and the like. The shear-thinning viscosity-imparting agent can be used alone or in combination of two or more kinds. Among these, water-soluble polysaccharides are preferably used because they can bring about an effect of improving the dry-up resistance performance.

[0062] Examples of the water-soluble polysaccharides include xanthan gum, welan gum, zeta sea gum, diutan gum, macrohomoopsis gum, succinoglycan (average molecular weight of about 1 million to 8 million) which is an organic acid-modified heteropolysaccharide whose constituent monosaccharides are glucose and galactose, guar gum, locust bean gum and its derivatives, hydroxyethyl cellulose, alkyl esters of alginic acid, glucomannan, carbohydrates having a gelling ability extracted from seaweeds such as agar and carrageenan, and the like. Among these, succinoglycan or xanthan gum is preferable because of the large effect of imparting shear-thinning viscosity, and succinoglycan is more preferable because of its excellent dispersion stability of the microcapsule pigments. As succinoglycan, those having an average molecular weight of about 1 million to 8 million are preferably used.

[0063] When the ink composition according to the present invention contains succinoglycan or xanthan gum, the content rate of succinoglycan or xanthan gum with respect to the total mass of the ink composition is preferably in the range of 0.01 to 1% by mass. By the content rate of succinoglycan or xanthan gum being within the above range, the ink ejection property from the pen tip can be maintained at a high level, and the aggregation of the microcapsule pigment can be suppressed.

[0064] The ink composition according to the present invention further comprises water. The water is not particularly limited, and examples thereof include tap water, ion-exchanged water, ultrafiltration water, and distilled water. The content rate of water with respect to the total mass of the ink composition is preferably in the range of 30 to 80% by mass, more preferably in the range of 40 to 70% by mass.

[0065] In addition to the essential components described above, the ink composition according to the present invention can combine optional components within a range that does not impair the effects of the present invention.

[0066] A surfactant can be blended in the ink composition according to the present invention. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, and any of them can be preferably used. Examples of the surfactant include phosphate ester-based surfactants, silicone-based surfactants, surfactants having an acetylene bond in the structure, and fluorine-based surfactants, and these surfactants are appropriately selected according to the components and uses of the ink composition. For example, when an ink composition is used in a water-based ballpoint pen equipped with a metal pen tip, it is preferable to use a phosphate ester surfactant. Since the phosphate ester surfactant has the property that the phosphate group is easily adsorbed to metals, it exhibits an effect as a lubricant in the ink composition. Therefore, when an ink composition containing a phosphate ester surfactant is applied to the above water-based ballpoint pen, the phosphate ester surfactant is adsorbed to the ball surface and the ball receiving seat of the ballpoint pen tip, and a lubricating layer composed of the phosphate ester surfactant is formed on the surfaces of the ball surface and the ball receiving seat, improving the lubricity between the ball and the ball receiving seat and enabling the ball to rotate smoothly. Thus, wear of the ball receiving seat can be suppressed, and the writing feeling such as writing quality can be improved.

[0067] The phosphate ester surfactant is a compound represented by the following formula (14).

Chemical formula

Chemical formula

[0068] As the phosphate ester surfactant, it is preferable that the hydrocarbon group is an alkyl group, an alkenyl group, or an aryl group, more preferably that the hydrocarbon group is an alkyl group, an alkenyl group, or an aryl group and the alkylene group is an ethylene group. Since the above compound exhibits an excellent effect in forming a lubricating layer on the surfaces of the ball and the ball receiving seat as described above, it can make the rotation of the ball during writing smoother and the writing feeling even better. The above phosphate ester surfactant may be an alkali metal salt or an amine salt.

[0069] In addition, among the phosphate ester surfactants in which the hydrocarbon group in formula (15) is an aryl group, that is, polyoxyalkylene aryl ether phosphates, compounds in which the aryl group has a plurality of aromatic rings are also included. The plurality of aromatic rings refers to a plurality of monocyclic aromatic rings or polycyclic aromatic rings having two or more rings. For example, 2 to 4 benzene rings, naphthalene rings, etc. can be exemplified. Further, the aryl group may include a monocyclic aromatic ring and a polycyclic aromatic ring having two or more rings in its structure.

[0070] Examples of the above polyoxyalkylene aryl ether phosphates include polyoxyethylene monostyrylphenyl ether phosphate, polyoxyethylene distyrylphenyl ether phosphate, polyoxyethylene tristyrylphenyl ether phosphate, polyoxyethylene cumylphenyl ether phosphate, polyoxyethylene naphthyl ether phosphate, and the like.

[0071] When the ink composition according to the present invention contains a phosphate ester surfactant, the content of the phosphate ester surfactant relative to the total mass of the ink composition is preferably in the range of 0.1 to 3% by mass, more preferably 0.5 to 1.5% by mass. When the content of the phosphate ester surfactant is within the above range, the dissolution stability of the phosphate ester surfactant is good, and it becomes easy to make the ball rotation smooth.

[0072] Although the phosphate ester surfactant is not particularly limited, it preferably has an HLB value of 9 to 18, more preferably 10 to 18. The phosphate ester surfactant having an HLB value within the above range has high solubility in the ink composition according to the present invention, excellent stability over time in the ink composition, and adsorbs on the surface of the microcapsule pigment to suppress aggregation of the microcapsule pigments. Further, even when the temperature of the ink composition changes excessively, the phosphate ester surfactant having an HLB value of 9 to 18 adsorbs on the surface of the microcapsule pigment without being affected by the temperature change, and aggregation of the microcapsule pigments can be suppressed. This is presumably because an interaction acts between PVP having a mass average molecular weight of 3,000 to 2,000,000 and the phosphate ester surfactant in the ink composition, and the dispersion stability of the microcapsule pigment adsorbed with the phosphate ester surfactant on the surface is further stabilized by PVP. A ballpoint pen (reversible thermochromic ballpoint pen) containing an ink composition containing a reversible thermochromic microcapsule pigment as a colorant may cause the ink to fade when exposed to high temperatures in summer. In that case, the ink can be recolored by exposing it to a low temperature at which the ink freezes. However, if the ink composition undergoes an excessive temperature change, the microcapsule pigments in the ink composition may aggregate, resulting in a decrease in ink ejection performance. However, by blending a phosphate ester surfactant having an HLB value of 9 to 18 into the ink composition according to the present invention, even when the ink composition undergoes an excessive temperature change, due to the interaction between PVP and the phosphate ester surfactant described above, aggregation of the microcapsule pigments can be suppressed without being affected by the temperature change. As a result, the microcapsule pigments exhibit excellent dispersion stability, and even when the state of the ink changes from liquid to solid or from solid to liquid with freezing and thawing of the ink composition, aggregation of the microcapsule pigments and a decrease in ink fluidity are suppressed. Therefore, it becomes easy to obtain an ink composition having excellent ink ejection performance from the pen tip.

[0073] When a ballpoint pen refill or a ballpoint pen has a metallic writing tip (pen tip), the pen tip may corrode if the ink composition contained in the ballpoint pen is acidic. However, an ink composition containing a phosphate ester surfactant with an HLB value of 9 to 18 can suppress the aggregation of microcapsule pigments even if it is not acidic, so that the ink can be made from neutral to alkaline and used for a ballpoint pen refill or a ballpoint pen having a metallic pen tip. That is, an ink composition containing a phosphate ester surfactant with an HLB value of 9 to 18 is preferably used for a ballpoint pen refill or a ballpoint pen having a metallic ballpoint pen tip.

[0074] The HLB value is a numerical value based on the Griffin method and is a value calculated by the following formula (16). The HLB value by the Griffin method is in the range of 0 to 20, and the larger the numerical value, the more hydrophilic the compound is. HLB value = 20 × (mass% of hydrophilic group) = 20 × (sum of formula weights of hydrophilic groups / molecular weight of surfactant) (16)

[0075] A pH adjuster can be incorporated into the ink composition according to the present invention, and various acids or bases can be used to adjust the pH of the ink composition to an appropriate range. Examples of the pH adjuster include inorganic basic compounds such as ammonia and sodium hydroxide / inorganic acidic compounds such as phosphoric acid, hydrochloric acid, sulfuric acid, and nitric acid / inorganic salt compounds such as sodium carbonate and sodium phosphate / water-soluble amine compounds such as triethanolamine and diethanolamine, urea, dimethylurea, diethylurea, hydroxymethylurea, or hydroxyethylurea, or organic basic compounds such as acetamide or N-methylacetamide / organic acidic compounds such as lactic acid, citric acid, and tartaric acid / organic salt compounds such as sodium acetate, sodium bicarbonate, and sodium tartrate. When the ink composition according to the present invention contains a pH adjuster, the content rate of the pH adjuster with respect to the total mass of the ink composition is preferably in the range of 0.1 to 5% by mass, more preferably 0.5 to 2% by mass.

[0076] In the ink composition according to the present invention, a water-soluble organic solvent compatible with water can be blended, and the quick-drying property of the ink can be improved. Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thioethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, and N-methyl-2-pyrrolidone. The water-soluble organic solvent can be used alone or in combination of two or more. When the ink composition according to the present invention contains a water-soluble organic solvent, the content of the water-soluble organic solvent relative to the total mass of the ink composition is preferably in the range of 1 to 40% by mass, more preferably 5 to 30% by mass, and still more preferably 10 to 25% by mass. When the content of the water-soluble organic solvent exceeds 40% by mass, the ink viscosity tends to increase, the ink ejection property of the ballpoint pen containing the ink composition deteriorates, and the writing performance is likely to be inhibited. On the other hand, when the blending ratio is less than 1% by mass, the effect of suppressing moisture evaporation becomes poor.

[0077] In the ink composition according to the present invention, resins such as acrylic resin, styrene-maleic acid copolymer, cellulose derivative, and polyvinyl alcohol can be blended, and the fixing property and viscosity to the paper surface can also be imparted.

[0078] The ink composition according to the present invention can contain dextrin. Since dextrin is excellent in film-forming properties, when the ink composition is applied to a ballpoint pen, it is possible to suppress the volatilization of a medium such as water in the ink composition from the pen tip. The dextrin is preferably a sugar mixture containing a starch saccharide of 8 sugars or more and / or a reduced product thereof. And this sugar mixture preferably contains 30 mass% or more of starch saccharides of 8 sugars or more, more preferably 50 mass% or more, and still more preferably 70 mass% or more. When the ink composition according to the present invention contains dextrin, the content rate of dextrin with respect to the total mass of the ink composition is preferably in the range of 0.1 to 5% by mass. When the content rate of dextrin is within the above range, it is possible to maintain the ink ejection property from the pen tip at a high level and suppress ink dripping and the volatilization of a medium such as water in the ink composition from the pen tip.

[0079] In the ink composition according to the present invention, various additives can be blended as necessary. Examples of the additive include rust preventives such as benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, and saponin, preservatives or fungicides such as phenol, sodium salt of 1,2-benzothiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, bubble absorbers such as ascorbic acids, erythorbic acids, α-tocopherol, catechins, synthetic polyphenols, kojic acid, alkylhydroxylamines, oxime derivatives, α-glucosylrutin, α-lipoic acid, phosphonates, phosphinates, sulfites, sulfoxylates, dithionites, thiosulfates, thiourea dioxide, Reduced or non-reduced starch hydrolyzates, disaccharides such as trehalose, oligosaccharides, sucrose, cyclodextrin, glucose, dextrin, sorbitol, mannitol, and wetting agents such as sodium pyrophosphate and the like can be exemplified. Furthermore, an antifoaming agent, a dispersant, a specific gravity adjuster, etc. can also be blended.

[0080] A lubricant can also be blended in the ink composition according to the present invention, and wear of the ball refill of the ballpoint pen or the ball receiving seat of the ballpoint pen can be easily prevented. Examples of the lubricant include higher fatty acids such as oleic acid, nonionic surfactants having a long-chain alkyl group, polyether-modified silicone oil, tri(alkoxycarbonylmethyl ester) of thiophosphorous acid and tri(alkoxycarbonylethyl ester) of thiophosphorous acid, phosphoric acid monoesters of polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether, phosphoric acid diesters of polyoxyethylene alkyl ether or polyoxyethylene alkylaryl ether, and their metal salts, ammonium salts, amine salts, and alkanolamine salts.

[0081] In addition, a non-thermochromic colorant such as a general dye or pigment can be blended in the ink composition according to the present invention, and it exhibits a color change behavior from colored (1) to colored (2).

[0082] The method for producing the ink composition according to the present invention is not particularly limited, and any conventionally known method can be used. Specifically, the ink composition can be produced by stirring a mixture containing each of the above components with various stirrers such as a propeller stirrer, a homodisper, or a homomixer, or by dispersing with various dispersers such as a bead mill.

[0083] The viscosity of the ink composition according to the present invention is, in an environment at 20°C, a rotational speed of 1 rpm (shearing rate: 3.84 sec -1When measured under the conditions of -1 ), since the sedimentation or aggregation of the microcapsule pigment can be suppressed, it is preferably in the range of 1 to 2000 mPa·s, more preferably 3 to 1500 mPa·s, and still more preferably 500 to 1000 mPa·s. Also, in an environment of 20°C, at a rotational speed of 100 rpm (shearing rate: 384 sec -1 ), when measured under the conditions of ), the ink ejection property from the pen tip of the ballpoint pen can be made good. Therefore, the viscosity is preferably in the range of 1 to 200 mPa·s, more preferably 10 to 100 mPa·s, and still more preferably 20 to 50 mPa·s. By having the viscosity within the above range, the dispersion stability of the microcapsule pigment and the easy fluidity of the ink in the mechanism of the ballpoint pen can be maintained at a high level. The viscosity is measured using a rheometer [manufactured by TA Instruments, product name: Discovery HR-2, cone plate (diameter 40 mm, angle 1°)] with the ink placed in an environment of 20°C at a rotational speed of 1 rpm (shearing rate: 3.84 sec -1 ), or at a rotational speed of 100 rpm (shearing rate: 384 sec -1 ).

[0084] The surface tension of the ink composition according to the present invention is preferably in the range of 20 to 50 mN / m, more preferably 25 to 45 mN / m in an environment of 20°C. By having the surface tension within the above range, it is easy to suppress bleeding of the writing line and ink penetration through the paper, and the wettability of the ink to the paper can be improved. The surface tension is a value measured by the vertical plate method using a platinum plate with the ink placed in an environment of 20°C using a surface tension measuring instrument [manufactured by Kyowa Interface Science Co., Ltd., product name: DY-300].

[0085] The pH of the ink composition according to the present invention is preferably in the range of 4 to 9, more preferably 4 to 8. By having the pH within the above range, aggregation or sedimentation of the microcapsule pigment contained in the ink at low temperatures can be suppressed. The pH value was measured using a pH meter [manufactured by Toa DKK Corporation, product name: IM-40S] with the ink placed in an environment at 20°C.

[0086] Since the ink composition according to the present invention has shear-thinning properties, it is particularly useful as an aqueous ink composition for ballpoint pens, and is used by filling a ballpoint pen refill having a ballpoint pen tip attached to the writing tip portion or a ballpoint pen.

[0087] By accommodating the ink composition according to the present invention in an ink container and directly connecting a ballpoint pen tip or connecting the ink container and the tip via a connecting member, a ballpoint pen refill (hereinafter sometimes referred to as a "refill") can be formed. Examples of the ballpoint pen tip include a tip that holds a ball in a ball-holding portion formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, a tip that holds a ball in a ball-holding portion formed by cutting a metal material with a drill or the like, a tip provided with a resin ball seat inside a metal or plastic tip, or a tip in which the ball held by the above tip is biased forward by a spring body. The ballpoint pen tip preferably includes a metal pipe having at least a straight cylindrical body (straight tubular cylindrical body) at the tip portion. Examples of the shape of such a ballpoint pen tip include one made of a metal pipe whose entire ballpoint pen tip is a straight cylindrical body, or one having a straight metal pipe at the tip portion and a shape in which the outer diameter and inner diameter expand rearward thereof. Among these, the latter is preferable because of its good ink ejection property. Further, by combining the ink composition according to the present invention with a ballpoint pen having a ball diameter of, for example, 0.2 to 0.5 mm among such pipe-type ballpoint pen tips, a ballpoint pen excellent in ink ejection property and dry-up resistance performance can be obtained.

[0088] The materials of the ballpoint pen tip and the ball are not particularly limited, and examples thereof include cemented carbide (carbide), stainless steel, ruby, ceramic, resin, and rubber. Further, the ball can be subjected to a surface treatment such as a DLC coating. The diameter of the ball is generally 0.2 to 3 mm, preferably 0.2 to 2 mm, more preferably 0.2 to 1.5 mm, still more preferably 0.2 to 1 mm, and particularly preferably 0.2 to 0.5 mm. Generally, a ballpoint pen equipped with a ball having a small diameter has a small amount of ink on the ball surface, so the ball surface is likely to dry, and writing defects such as scratching and skipping are likely to occur. However, since the ink composition according to the present invention has excellent anti-drying performance, drying at the writing tip is suppressed and writing defects are less likely to occur. Therefore, it is preferably used for a ballpoint pen equipped with a ball having a small diameter, particularly a ball having a diameter of 0.2 to 0.4 mm.

[0089] As the ink container, for example, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon, or a metal tubular body is used. In addition, in order to prevent the ink composition to be contained from being denatured by oxygen, a molded body made of a resin having low oxygen permeability, for example, an ethylene-vinyl alcohol copolymer, a vinylidene chloride resin, an acrylonitrile resin, a polyester resin, etc. is preferably used. The ink container may have a single-layer structure or a multilayer structure. When the ink container has a multilayer structure, at least one layer is preferably made of an ethylene-vinyl alcohol copolymer, a vinylidene chloride resin, an acrylonitrile resin, or a polyester resin. Further, when the ink container is an ink container having a multilayer structure of three or more layers and layers made of an ethylene-vinyl alcohol copolymer, a vinylidene chloride resin, an acrylonitrile resin, or a polyester resin are combined, those layers are preferably arranged other than the outermost layer and the innermost layer.

[0090] An ink backflow prevention body is filled at the rear end of the ink contained in the ink container. Examples of the ink backflow prevention body include a liquid plug or a solid plug. The liquid plug is composed of a non-volatile liquid and / or a hardly volatile liquid. For example, petrolatum, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, an oligomer or co-oligomer of α-olefin, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, polyether-modified silicone oil, and fatty acid-modified silicone oil can be exemplified. The non-volatile liquid and / or the hardly volatile liquid can be used alone or in combination of two or more.

[0091] It is preferable to add a thickening agent to the non-volatile liquid and / or the hardly volatile liquid to thicken it to a suitable viscosity. Examples of the thickening agent include silica with a hydrophobic surface treatment, fine particle silica with a methylation surface treatment, aluminum silicate, swelling mica, clay-based thickening agents such as bentonite and montmorillonite with a hydrophobic treatment, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, and zinc stearate, tribenzylidene sorbitol, fatty acid amide, amide-modified polyethylene wax, hydrogenated castor oil, dextrin-based compounds such as fatty acid dextrin, and cellulose-based compounds.

[0092] Examples of the solid plug include solid plugs made of polyethylene, polypropylene, and polymethylpentene. As the ink backflow prevention body, the above-mentioned liquid plug and solid plug can also be used in combination.

[0093] A resin film for preventing drying of the pen tip can also be fixed to the tip of the ballpoint pen tip. By fixing the resin film so as to cover the ball at the tip of the chip, the ball holding part, and the gap between the ball and the ball holding part, it is possible to prevent drying of the tip of the chip and volatilization of a medium such as water in the ink composition. As the resin for forming the resin film, for example, a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, etc. can be used.

[0094] By accommodating the above ballpoint pen refill in the shaft tube, a ballpoint pen can be formed. The above ballpoint pen is provided with a cap that is attached so as to cover the writing tip portion to form a capped ballpoint pen, thereby preventing the writing tip portion from drying out and becoming unable to write, or being contaminated or damaged. Further, by providing a projecting and retracting mechanism that allows the writing tip portion to project and retract from the ballpoint pen body (shaft tube) to form a retractable ballpoint pen, it is possible to prevent the writing tip portion from being contaminated or damaged.

[0095] Any ballpoint pen provided with a projecting and retracting mechanism can be used as long as the writing tip portion is housed in the shaft tube in a state of being exposed to the outside air and the writing tip portion projects from the shaft tube opening by the operation of the projecting and retracting mechanism. Examples of the projecting and retracting mechanism include (1) a side slide type projecting and retracting mechanism in which an operating portion (clip) that can move in the front-rear direction is provided to project radially outward from the rear side wall of the shaft tube, and the writing tip portion is projected and retracted from the front end opening of the shaft tube by sliding the operating portion forward, (2) a rear end knock type projecting and retracting mechanism in which the writing tip portion is projected and retracted from the front end opening of the shaft tube by pressing an operating portion provided at the rear end of the shaft tube forward, (3) a side knock type projecting and retracting mechanism in which the writing tip portion is projected and retracted from the front end opening of the shaft tube by pressing an operating portion projecting from the outer surface of the side wall of the shaft tube radially inward, (4) a rotary type projecting and retracting mechanism in which the writing tip portion is projected and retracted from the front end opening of the shaft tube by rotating an operating portion at the rear of the shaft tube, etc. The ink composition according to the present invention is excellent in dry-up resistance performance and hardly causes writing defects such as streaks and skips due to drying at the writing tip portion, and thus is suitably used for a retractable ballpoint pen.

[0096] In addition, a ballpoint pen can also be formed by directly filling a ballpoint pen having a ballpoint pen tip attached to the writing tip portion with the ink composition according to the present invention. Examples of such ballpoint pens include those in which the ink composition according to the present invention is filled into a ballpoint pen body (shaft cylinder) communicating with a ballpoint pen tip having a ball attached to the tip portion, and an ink backflow prevention body that follows as the ink is consumed is in close contact with the end face of the ink.

[0097] Examples of the ballpoint pen tip include a tip in which a ball is held by a ball holding portion formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, a tip in which a ball is held by a ball holding portion formed by cutting a metal material with a drill or the like, a tip in which a resin ball seat is provided inside a metal or plastic tip, or a tip in which the ball held by the above tip is biased forward by a spring body.

[0098] The materials of the ballpoint pen tip and the ball are not particularly limited, and examples include cemented carbide (carbide), stainless steel, ruby, ceramic, resin, and rubber. Furthermore, the ball can also be subjected to a surface treatment such as a DLC coating. The diameter of the ball is generally 0.2 to 3 mm, preferably 0.2 to 2 mm, more preferably 0.2 to 1.5 mm, still more preferably 0.2 to ím, and particularly preferably 0.2 to 0.5 mm. Generally, a ballpoint pen equipped with a ball having a small diameter has a small amount of ink on the ball surface, so the ball surface is likely to dry, and writing defects such as scratching and skipping are likely to occur. However, since the ink composition according to the present invention has excellent anti-drying performance, drying at the writing tip portion is suppressed and writing defects are less likely to occur. Therefore, it is preferably used for a ballpoint pen equipped with a ball having a small diameter, particularly a ball having a diameter of 0.2 to 0.4 mm.

[0099] Examples of the shaft cylinder for accommodating the ink composition include molded bodies made of thermoplastic resins such as polyethylene, polypropylene, polyethylene terephthalate, and nylon. Furthermore, by making the shaft cylinder light-shielding, deterioration of the ink composition accommodated therein due to light can be suppressed. The ballpoint pen tip may be directly connected to the shaft cylinder, or the shaft cylinder and the ballpoint pen tip may be connected via a connecting member.

[0100] An ink backflow prevention body is filled at the rear end of the ink accommodated in the shaft cylinder. Examples of the ink backflow prevention body include a liquid plug and a solid plug. The liquid plug is composed of a non-volatile liquid and / or a hardly volatile liquid. Examples thereof include petrolatum, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, an oligomer or co-oligomer of α-olefin, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, polyether-modified silicone oil, and fatty acid-modified silicone oil. The non-volatile liquid and / or the hardly volatile liquid can be used alone or in combination of two or more.

[0101] It is preferable to add a thickening agent to the non-volatile liquid and / or the hardly volatile liquid to thicken it to a suitable viscosity. Examples of the thickening agent include clay-based thickening agents such as silica with a hydrophobic surface, fine particle silica with a methylated surface, aluminum silicate, swelling mica, bentonite and montmorillonite subjected to hydrophobic treatment; fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, and zinc stearate; tribenzylidene sorbitol; fatty acid amide; amide-modified polyethylene wax; hydrogenated castor oil; dextrin-based compounds such as fatty acid dextrin; and cellulose-based compounds.

[0102] Examples of the solid plug include solid plugs made of polyethylene, polypropylene, and polymethylpentene. As the ink backflow prevention body, the above-described liquid plug and solid plug can also be used in combination.

[0103] Furthermore, the form of the ballpoint pen is not limited to the above-described configuration. In addition to attaching chips of different forms or attaching pen tips that lead out inks of different color tones, a composite ballpoint pen (such as a double-headed type or a pen tip extending type) that attaches chips of different forms and has different color tones of inks led out from each chip may also be used. Also, it can be a composite type retractable ballpoint pen in which a plurality of ballpoint pen refills are housed in a shaft cylinder, and the writing tip of any one of the ballpoint pen refills is retracted from and projected out of the shaft cylinder opening by the operation of a retracting mechanism.

[0104] It is possible to form a handwriting by writing on a writing surface using a ballpoint pen containing the ink composition according to the present invention, and the handwriting can be discolored by rubbing with a finger or by a heating tool or a cooling and heating tool. Examples of the heating tool include an energization heating discoloration tool equipped with a resistance heating element such as a PTC element, a heating discoloration tool filled with a medium such as warm water, a heating discoloration tool using steam, laser light, etc., and the application of a hair dryer. However, since it can be discolored by a simple method, a friction member and a friction body are preferable. Examples of the cooling tool include an energization cooling and heating discoloration tool using a Peltier element, a cooling and heating discoloration tool filled with a refrigerant such as cold water or ice pieces, a cold storage agent, and the application of a refrigerator or a freezer.

[0105] As the friction member and the friction body, elastomers such as elastomers rich in elasticity and capable of generating appropriate friction and frictional heat during rubbing, and plastic foams are preferable, but a plastic molded body, stone, wood, metal, fabric, etc. can also be used. In addition, the handwriting may be rubbed using a general eraser used to erase the handwriting by a pencil. However, since eraser dust is generated during rubbing, the above-described friction member and friction body that hardly generate eraser dust are preferably used. Examples of the materials for the friction member and the friction body include, for example, silicone resin, SEBS resin (styrene-ethylene-butadiene-styrene block copolymer), etc. Since the silicone resin tends to adhere to the erased portion due to rubbing and the handwriting is likely to be repelled when writing repeatedly, the SEBS resin is more preferably used.

[0106] The above-mentioned friction member or friction body may be a member of any shape separate from the ballpoint pen, but by providing it on the ballpoint pen, it can be made excellent in portability. Further, a ballpoint pen set can also be obtained by combining a ballpoint pen and a friction member or friction body of any shape separate from the ballpoint pen.

[0107] When the ballpoint pen according to the present invention is a cap-type ballpoint pen, the location where the friction member or friction body is provided is not particularly limited. For example, the cap itself can be formed of a friction member, the shaft cylinder itself can be formed of a friction member, or when a clip is provided, the clip itself can be formed of a friction member, or a friction member or friction body can be provided at the tip of the cap (top) or the rear end of the shaft cylinder (the portion where the writing tip is not provided). Also, when the ballpoint pen according to the present invention is a retractable ballpoint pen, the location where the friction member or friction body is provided is not particularly limited. For example, the shaft cylinder itself can be formed of a friction member, or when a clip is further provided, the clip itself can be formed of a friction member, or a friction member or friction body can be provided near the opening of the shaft cylinder, at the rear end of the shaft cylinder (the portion where the writing tip is not provided), or at the knock portion.

Examples

[0108] Examples are shown below, but the present invention is not limited thereto. Unless otherwise specified, "parts" in the examples indicate "parts by mass".

[0109] Preparation of Reversible Thermochromic Microcapsule Pigment A As component (a), 4.5 parts of 2-(2-chloroanilino)-6-di-n-butylaminofluorane; as component (b), 4.5 parts of 1,1-bis(4-hydroxyphenyl)n-decane and 7.5 parts of 2,2-bis(4-hydroxyphenyl)hexafluoropropane; as component (c), 50 parts of 4-benzyloxyphenylethyl caprate. The resulting reversible thermochromic composition was added to a mixed solution consisting of 35 parts of an aromatic isocyanate prepolymer as a wall film material and 40 parts of a co-solvent, and then emulsified and dispersed in an 8% aqueous polyvinyl alcohol solution. After continuously stirring while heating, 2.5 parts of a water-soluble aliphatic modified amine was added, and stirring was continued to prepare a microcapsule dispersion. By centrifugation from the above microcapsule dispersion, a reversible thermochromic microcapsule pigment A with an average particle diameter of 1.9 μm was obtained. The reversible thermochromic microcapsule pigment A has a complete color development temperature t1 of -20°C and a complete color fading temperature t4 of 59°C, and reversibly changes from black to colorless with temperature change.

[0110] Preparation of Reversible Thermochromic Microcapsule Pigment B As component (a), 2 parts of 3-(4-diethylamino-2-hexyloxyphenyl)-3-(1-ethyl-2-methylindol-3-yl); as component (b), 8 parts of 2,2-bis(4-hydroxyphenyl)hexafluoropropane; as component (c), 50 parts of 4-benzyloxyphenylethyl caprate. The resulting reversible thermochromic composition was added to a mixed solution consisting of 35 parts of an aromatic isocyanate prepolymer as a wall film material and 40 parts of a co-solvent, and then emulsified and dispersed in an 8% aqueous polyvinyl alcohol solution. After continuously stirring while heating, 2.5 parts of a water-soluble aliphatic modified amine was added, and stirring was continued to prepare a microcapsule dispersion. By centrifugation from the above microcapsule dispersion, a reversible thermochromic microcapsule pigment B with an average particle diameter of 2.3 μm was obtained. The reversible thermochromic microcapsule pigment B has a complete color development temperature t1 of -20°C and a complete color fading temperature t4 of 60°C, and reversibly changes from blue to colorless with temperature change.

[0111] Example 1 Preparation of Aqueous Ink Composition 18 parts of reversible thermochromic microcapsule pigment A (previously cooled to -20°C or lower to develop a black color), 2 parts of N-vinyl-2-pyrrolidone polymer (PVP) (weight average molecular weight: 15,000), 0.2 part of a shear-thinning viscosity-imparting agent (sucsinoglycan) [manufactured by Sankyo Co., Ltd., product name: Reozan], 0.5 part of a phosphate ester surfactant (polyoxyethylene tristyrylphenyl ether phosphate), 5 parts of glycerin, 2 parts of dextrin [manufactured by Sanwa Starch Industry Co., Ltd., product name: Sandek 30], 0.2 part of a preservative [manufactured by Lonza Japan Co., Ltd., Proxel XL-2(S)], and 72.1 parts of water were mixed to prepare an aqueous ink composition. Also, the content ratio of PVP (P PVP ) to the total mass of the ink composition is 2, and the content ratio of the microcapsule pigment (P MC ) to the total mass of the ink composition and the content ratio of PVP (P PVP ) to the total mass of the ink composition, the ratio (P MC / P PVP ) was 9.

[0112] Manufacture of Ballpoint Pen The above ink composition was suction-filled into an ink container made of a polypropylene pipe, and then connected to a ballpoint pen tip holding a 0.5 mm diameter cemented carbide ball at the tip via a resin holder. Next, from the rear end of the ink container, an ink backflow prevention body (ink stopper) having viscoelasticity mainly composed of polybutene was filled, and a tail plug was further fitted to the rear part of the pipe, and degassing treatment was performed by centrifugation to obtain a ballpoint pen refill. Next, the above refill was incorporated into a shaft cylinder to manufacture a ballpoint pen (retractable ballpoint pen). The above ballpoint pen has a structure in which the tip provided on the ballpoint pen refill is housed in the shaft cylinder in a state exposed to the outside air, and the tip protrudes from the front end opening of the shaft cylinder by the operation of a clip-shaped retractable mechanism (slide mechanism) provided on the rear side wall of the shaft cylinder. Note that an SEBS resin is attached to the rear end portion of the shaft cylinder as a friction member.

[0113] Examples 2 to8 , Reference Examples 1 to 3 and Comparative Examples 1 to 6 An aqueous ink composition was prepared in the same manner as in Example 1, except that the types and amounts of the materials to be blended were changed to those described in Table 1 below. Also, P in each ink composition PVP , and P MC / P PVP is as described in Table 1. The ballpoint pen was produced in the same manner as in Example 1, except that the diameter of the ball used was changed to that described in Table 1.

[0114]

Table 1

[0115] The contents of the materials in Table 1 will be described according to the footnote numbers. (1) Black reversible thermochromic microcapsule pigment (2) Blue reversible thermochromic microcapsule pigment (3) Mass average molecular weight: 15,000 (4) Mass average molecular weight: 500,000 (5) Mass average molecular weight: 3 million (6) Mass average molecular weight: 2,000 (7) Succinoglycan 〔Manufactured by Sankyo Co., Ltd., Product name: Leosan〕 (8) Xanthan gum 〔Manufactured by Sankyo Co., Ltd., Product name: Kelzan〕 (9) Polyoxyethylene tristyrylphenyl ether phosphate (HLB value: 16) (10) Polyoxyethylene tridecyl ether phosphate (HLB value: 12) (11) Mixture of monoester, diester, and triester of polyoxyethylene distyrylphenyl ether phosphate (HLB value: 5) (12) Dextrin 〔Manufactured by Sanwa Starch Industry Co., Ltd., Product name: Sandek 30〕 (13) Triethanolamine (14) Antifungal agent [Manufactured by Lonza Japan Co., Ltd., Product Name: Proxel XL-2(S)]

[0116] [pH measurement] Examples 1 to 8 , Reference Examples 1 to 3 For each ink composition obtained in Examples 1 to

[0117] [Viscosity measurement] Examples 1 to 8 , Reference Examples 1 to 3 For each ink composition obtained in Examples 1 to -1 and Comparative Examples 1 to 6, using a rheometer [manufactured by TA Instruments, product name: Discovery HR-2, cone plate (diameter 40 mm, angle 1°)], at room temperature (20°C) environment, rotation speed 1 rpm (shear rate: 3.84 sec -1 ) and rotation speed 100 rpm (shear rate: 384 sec

[0118]

Table 2

[0119] Evaluation of initial writing performance Examples 1 to 8 , Reference Examples 1 to 3 Using each ballpoint pen of Examples 1 to and Comparative Examples 1 to 6, at room temperature (20°C) environment, in the direction parallel to the short side of an A4-sized test paper (portrait orientation), 12 oval-shaped circles (major axis about 15 mm, minor axis about 8 mm) per line were handwritten in a spiral so that the circles touched each other, and 3 lines were continuously written. Note that writing paper A conforming to the former JIS P3201 was used for the test paper. The obtained handwriting was visually confirmed, and the handwriting was evaluated according to the following criteria. The evaluation results are as shown in Table 3 below. B: Slight smudging and skipped lines were observed in the handwriting, but it was at a level with no practical problems. C: Many smudges and skipped lines were observed in the handwriting. D: It was impossible to write.

[0120] Evaluation of writing performance over time Each of the ballpoint pens used in the above writing test was placed horizontally in a thermostat set at 50°C for 60 days. After 60 days, it was taken out of the thermostat and, in an environment at room temperature (20°C), 12 oval-shaped circles (about 15 mm in major axis and 8 mm in minor axis) per line were handwritten in a spiral so that the circles were in contact with each other in the direction parallel to the short side of the A4-sized test paper (vertically), and three consecutive lines were written. Note that writing paper A conforming to the old JIS P3201 was used for the test paper. The obtained handwriting was visually confirmed, and the handwriting was evaluated according to the following criteria. The evaluation results are as shown in Table 3 below. A: There were no smudges or skipped lines in the handwriting, and good handwriting was obtained. B: Slight smudging and skipped lines were observed in the handwriting, but it was at a level with no practical problems. C: Many smudges and skipped lines were observed in the handwriting. D: It was impossible to write.

[0121] Evaluation of ink stability Examples 1 to 8 , Reference Examples 1 to 3 and each of the ballpoint pens of Comparative Examples 1 to 6 were placed horizontally in a thermostat set at 60°C for 14 days. After 14 days, it was taken out of the thermostat, and then placed horizontally in a thermostat set at -20°C for 1 day. After 1 day, it was taken out of the thermostat, and the state of the ink contained in the refill of the ballpoint pen was visually confirmed and evaluated according to the following criteria. The evaluation results are as shown in Table 3 below. A: No pigment sedimentation or the like was seen in the ink in the refill, and it had the same appearance as the initial state. B: Slight separation due to pigment aggregation and sedimentation was seen in the ink in the refill, but the handwriting with the ballpoint pen was at a level with no practical problems. C: Separation due to aggregation or sedimentation of pigments was observed in the ink in the refill, and many streaks and skips were confirmed in the handwriting with the ballpoint pen, or it was impossible to write.

[0122]

Table 3

Explanation of Symbols

[0123] t1 Complete color development temperature t2 Color development start temperature t3 Fading start temperature t4 Complete fading temperature T1 Complete fading temperature T2 Fading start temperature T3 Color development start temperature T4 Complete color development temperature ΔH Hysteresis width

Claims

1. A reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color-forming reaction of the components (a) and (b), An N-vinyl-2-pyrrolidone polymer having a mass average molecular weight of 3,000 to 2,000,000, Succinoglycan, Water, A water-based ink composition for a reversible thermochromic ballpoint pen comprising at least, When the content rate of the N-vinyl-2-pyrrolidone polymer with respect to the total mass of the ink composition is denoted as PVP and the content rate of the reversible thermochromic microcapsule pigment with respect to the total mass of the ink composition is denoted as PMC, regarding the PVP and PMC, 3.5 ≦ PMC / PVP ≦ 40 A water-based ink composition for a reversible thermochromic ballpoint pen satisfying the above.

2. The P ＰＶＰ aqueous ink composition for a reversible thermochromic ballpoint pen according to Claim 1, wherein P is 0.1 to 10% by mass.

3. The water-based ink composition for a reversible thermochromic ballpoint pen according to claim 1 or 2, further comprising a phosphate ester surfactant having an HLB value of 9 to 18.

4. The water-based ink composition for a reversible thermochromic ballpoint pen according to claim 1 or 2, further comprising a polyoxyalkylene aryl ether phosphate ester.

5. A refill containing the water-based ink composition for a reversible thermochromic ballpoint pen according to any one of claims 1 to 4.

6. The refill according to claim 5, wherein the diameter of the ball provided at the writing tip of the refill is 0.2 to 0.4 mm.

7. An aqueous ballpoint pen comprising the refill according to claim 5 or 6 housed in a shaft cylinder.

8. The aqueous ballpoint pen according to claim 7, further comprising a retracting mechanism.

9. The aqueous ballpoint pen according to claim 7 or 8, comprising a friction member that changes the color of the handwriting by the aqueous ballpoint pen with frictional heat.

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