JP2022157764A - Aqueous ink composition for reversible thermochromic ball point pen, refill storing the same, and aqueous ball point pen - Google Patents

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 The present invention relates to a water-based ink composition for a reversible thermochromic ball-point pen, a refill containing the same, and a water-based ball-point pen. More particularly, the present invention relates to a reversible thermochromic water-based ink composition for a reversible thermochromic ball-point pen capable of suppressing drying of the writing tip of the ball-point pen and forming good handwriting, and a refill and water-based ball-point pen containing the same.

Conventionally, there has been proposed a writing instrument (reversible thermochromic ballpoint pen) containing a reversible thermochromic water-based ink composition capable of forming handwriting that can alternately memorize and retain the state before and after discoloration in a certain temperature range such as room temperature. (See Patent Document 1, for example).
The above writing instrument contains a reversible thermochromic microcapsule pigment as a coloring agent in the water-based ink composition. It tended to be difficult to obtain a high handwriting density compared to other writing instruments not encapsulated in capsules. In order to increase the handwriting density, it is conceivable to increase the blending ratio of the microcapsule pigment, but if the blending ratio is increased, the ink composition tends to dry up at the tip of the writing, resulting in blurring, line skipping, and the like. There was a tendency that writing defects tended to occur easily.
Water-based ink compositions for ballpoint pens are disclosed in which a sugar alcohol or a specific ester compound is blended in the water-based ink composition in order to improve the dry-up resistance of the writing tip (for example, Patent Documents 2 and 3). reference).
However, since the colorant used in the reversible thermochromic water-based ink composition is relatively special, even if the above-mentioned sugar alcohols or specific ester compounds that are applied to general ink compositions are used, they are excellent. It tends to be difficult to obtain the desired properties, and it is necessary to add a large amount in order to sufficiently develop the dry-up resistance, and the viscosity of the ink increases, which sometimes causes poor writing.

JP 2009-292878 A JP-A-8-239617 Japanese Patent Application Laid-Open No. 2001-226621

An object of the present invention is to provide a reversible thermochromic water-based ink composition for a reversible thermochromic ball-point pen, which exhibits excellent dry-up resistance at the writing tip and exhibits good ink ejection properties, as well as a refill and a water-based ball-point pen containing the same. .

The present invention is a reversible compound comprising at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of the components (a) and (b). A reversible thermochromic microcapsule pigment encapsulating a thermochromic composition, an N-vinyl-2-pyrrolidone polymer having a mass average molecular weight of 3,000 to 2,000,000, a shear thinning agent, water, A water-based ink composition for reversible thermochromic ballpoint pens comprising at least:
Furthermore, when P _PVP is the content of the N-vinyl-2-pyrrolidone polymer with respect to the total mass of the ink composition, the P _PVP is 0.1 to 10% by mass, and the ink composition When the content of the reversible thermochromic microcapsule pigment with respect to the total mass of the product is P _MC , the P _PVP and P _MC satisfy 3 ≤ P _MC /P _PVP ≤ 60, and the shear thinning property is provided It is required that the agent is succinoglycan and that it further contains a phosphate surfactant with an HLB value of 9-18.
Further, it is required that the diameter of the refill containing the water-based ink composition for a reversible thermochromic ball-point pen and the ball provided at the writing tip of the refill is 0.2 to 0.4 mm.
Furthermore, the water-based ball-point pen containing the refill in the barrel, further comprising a retracting mechanism for the water-based ball-point pen, and a friction member for discoloring the handwriting of the water-based ball-point pen due to frictional heat. and

The present invention is a reversible thermochromic water-based ink for ball-point pens that is excellent in dry-up resistance at the writing tip, exhibits excellent ink ejection properties, and is capable of suppressing poor writing such as blurring and line skipping to form good handwriting. The composition, as well as refills and water-based ballpoint pens containing the composition can be provided.

1 is a graph for explaining hysteresis characteristics in a color density-temperature curve of a heat-erasable reversible thermochromic composition. 1 is a graph for explaining hysteresis characteristics in a color density-temperature curve of a heat color-erasable reversible thermochromic composition having color memory properties.

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

The ink composition according to the present invention contains, as a colorant, a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition (hereinafter sometimes referred to as "microcapsule pigment" or "pigment"). .
The reversible thermochromic composition comprises: (a) an electron-donating color-forming organic compound; (b) an electron-accepting compound; and a reaction medium that determines. As a reversible thermochromic composition, before and after a predetermined temperature (discoloration point) described in Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, Japanese Patent Publication No. 1-29398, etc. At a temperature range above the high temperature side color change point, it is in a discolored state, and in a temperature range below the low temperature side color change point, it is in a colored state. The state of is maintained while the heat or cold required to develop the state is applied, but returns to the state exhibited in the normal temperature range when the application of heat or cold is no longer applied, and the hysteresis width (ΔH) is A reversible thermochromic composition of a heat-discoloring type (discolored by heating and developed by cooling) having a relatively small property (ΔH=1 to 7° C.) can be used (see FIG. 1).

In addition, the hysteresis width described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, JP-A-2005-1369, etc. It shows a large characteristic (ΔH = 8 to 70 ° C), and the shape of the curve plotting the change in color density due to temperature change is the case where the temperature is raised from the lower temperature side than the color change temperature range, and the opposite is the case where the temperature is higher than the color change temperature range. The color changes along a path that is significantly different from that when descending from the side, and the color development state in the temperature range of the complete color development temperature t ₁ or less, or the color disappearance state in the high temperature range of the complete color development temperature t ₄ or more, A heat decoloring type that has color memory properties in a specific temperature range [temperature range between color development start temperature t ₂ and decoloration start temperature t ₃ (substantial two-phase retention temperature range)] (discolors by heating and develops color by cooling) ) can also be used (see FIG. 2).

Specifically, as a reversible thermochromic composition having color memory, the complete color development temperature t ₁ is a temperature that can only be obtained in a freezer room, a cold region, or the like, that is, -50 to 0 ° C., preferably -40 to -5 ° C., more preferably -30 to -10 ° C., and the complete decoloring temperature t ₄ is the frictional heat of the friction body, the temperature obtained from a familiar heating tool such as a hair dryer, that is, 45 to 95 ° C., preferably 50 to 90 C., more preferably 60 to 80.degree. C., and .DELTA.H is specified to be 40 to 100.degree.

The components (a), (b), and (c) are specifically described below.

Component (a), that is, an electron-donating color-developing organic compound is a component that determines color, and is a compound that donates electrons to component (b), which is a color developer, to develop color.

Examples of electron-donating color-forming organic compounds include phthalide compounds, fluoran compounds, stilinoquinoline compounds, diazarhodamine lactone compounds, pyridine compounds, quinazoline compounds, and bisquinazoline compounds. preferable.
Examples of phthalide compounds include diphenylmethanephthalide compounds, phenylindolylphthalide compounds, indolylphthalide compounds, diphenylmethaneazaphthalide compounds, phenylindolylazaphthalide compounds, and derivatives thereof. Among them, phenylindolylazaphthalide compounds and derivatives thereof are preferred.
Examples of fluoran compounds include aminofluoran compounds, alkoxyfluoran compounds, derivatives thereof, and the like.

Compounds that can be used as the component (a) are exemplified below.
3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide,
3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide,
3,3-bis(1-n-butyl-2-methylindol-3-yl)phthalide,
3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide,
3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide,
3-(2-n-hexyloxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide,
3-[2-ethoxy-4-(N-ethylanilino)phenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide,
3-(2-acetamido-4-diethylaminophenyl)-3-(1-propyl-2-methylindol-3-yl)-4-azaphthalide,
3,6-bis(diphenylamino)fluorane,
3,6-bis(N-phenyl-Np-tolylamino)fluorane,
3,6-dimethoxyfluorane,
3,6-di-n-butoxyfluorane,
2-methyl-6-(N-ethyl-Np-tolylamino)fluorane,
3-chloro-6-cyclohexylaminofluorane,
2-methyl-6-cyclohexylaminofluorane,
2-chloroamino-6-di-n-butylaminofluorane,
2-(2-chloroanilino)-6-di-n-butylaminofluorane,
2-(3-trifluoromethylanilino)-6-diethylaminofluorane,
2-(3-trifluoromethylanilino)-6-di-n-pentylaminofluorane,
2-dibenzylamino-6-diethylaminofluorane,
2-(N-methylanilino)-6-(N-ethyl-Np-tolylamino)fluorane,
1,3-dimethyl-6-diethylaminofluorane,
2-chloro-3-methyl-6-diethylaminofluorane,
2-anilino-3-methyl-6-diethylaminofluorane,
2-anilino-3-methoxy-6-diethylaminofluorane,
2-anilino-3-methyl-6-di-n-butylaminofluorane,
2-anilino-3-methoxy-6-di-n-butylaminofluorane,
2-xylidino-3-methyl-6-diethylaminofluorane,
2-anilino-3-methyl-6-(N-ethyl-Np-tolylamino)fluorane,
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′-on,
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′-on,
4,5,6,7-tetrachloro-3-(4-dimethylamino-2-methoxyphenyl)-3-(1-n-butyl-2-methylindol-3-yl)-1(3H)-iso benzofuranone,
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)-isobenzo Furanones,
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]xanthen]-3-one,
3′,6′-bis[phenyl(3-methylphenyl)amino]spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one,
3′,6′-bis[phenyl(3-ethylphenyl)amino]spiro[isobenzofuran-1(3H),9′-[9H]xanthen]-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]

As fluoranes, in addition to compounds having a substituent on the phenyl group forming the xanthene ring, a substituent on the phenyl group forming the xanthene ring and a substituent on the phenyl group forming the lactone ring (for example, , an alkyl group such as a methyl group, a halogen atom such as a chlorine atom, etc.) and exhibiting a blue or black color.

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

Compounds having an active proton include compounds having a phenolic hydroxyl group and its derivatives, carboxylic acids and their derivatives, acidic phosphoric acid esters and their derivatives, azole compounds and their derivatives, 1,2,3-triazoles and derivatives thereof, cyclic carbosulfimides, halohydrins having 2 to 5 carbon atoms, sulfonic acid and its derivatives, inorganic acids and the like. As the carboxylic acid and its derivative, an aromatic carboxylic acid and its derivative, or an aliphatic carboxylic acid having 2 to 5 carbon atoms and its derivative are preferable.
Pseudo-acidic compounds include metal salts of compounds having a phenolic hydroxyl group, metal salts of carboxylic acids, metal salts of acidic phosphoric acid esters, metal salts of sulfonic acids, aromatic carboxylic acid anhydrides, and aliphatic carboxylic acid anhydrides. , mixed anhydrides of aromatic carboxylic acids and sulfonic acids, cycloolefin dicarboxylic acid anhydrides, urea and its derivatives, thiourea and its derivatives, guanidine and its derivatives, and halogenated alcohols.
Examples of the compound group having electron vacancies include borates, borate esters, and inorganic salts.

Among the above components (b), a compound having a phenolic hydroxyl group is preferable because it can more effectively exhibit thermochromic properties.
Compounds having a phenolic hydroxyl group include a wide range of compounds from monophenol compounds to polyphenol compounds, and further include bisphenol compounds, trisphenol compounds, phenol-aldehyde condensed resins, and the like. A compound having a phenolic hydroxyl group preferably has at least two benzene rings. Moreover, the compound having a phenolic hydroxyl group may have a substituent 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.

Examples of metals contained in metal salts of compounds having phenolic hydroxyl groups include sodium, potassium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, and molybdenum. etc. can be exemplified.

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

Examples of compounds having two phenolic hydroxyl groups include
Resorcinol,
2-methylresorcin,
4-n-hexylresorcin,
4-n-octylresorcin,
4-tert-octylresorcin,
4-benzoylresorcin,
4-nitroresorcin,
β-methyl resorcinate,
β-benzyl resorcinate,
2-chloro-4-pentanoylresorcin,
6-chloro-4-pentanoylresorcin,
2-chloro-4-hexanoylresorcin,
6-chloro-4-hexanoylresorcin,
2-chloro-4-propanoylresorcin,
6-chloro-4-propanoylresorcin,
2,6-dichloro-4-propanoylresorcin,
6-fluoro-4-propanoylresorcin,
2-chloro-4-phenylacetylresorcinol,
6-chloro-4-phenylacetylresorcin,
2-chloro-4-β-phenylpropanoylresorcin,
6-chloro-4-β-phenylpropanoylresorcin,
2-chloro-4-phenoxyacetylresorcin,
6-chloro-4-phenoxyacetylresorcin,
4-benzoyl-2-chlororesorcin,
6-chloro-4-m-methylbenzoylresorcin,
4-[1′,3′,4′,9′a-tetrahydro-6′-hydroxyspiro(cyclohexane-1,9′-[9H]-xanthene)-4′a-[2H]-yl]-1 , 3-benzenediol,
hydroquinone,
methyl hydroquinone,
trimethylhydroquinone,
catechol,
4-tert-butyl catechol,
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,
Examples include 2,4-dihydroxy-3',4',5'-triethoxybenzophenone.

Furthermore, as a bisphenol compound, 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)butyl propionate,
2,2-bis(4-hydroxy-3-methylphenyl)methylpropionate,
2,2-bis(4-hydroxyphenyl)ethyl propionate,
2,2-bis(4-hydroxyphenyl)-4-methylpentane,
2,2-bis(4-hydroxyphenyl)-4-methylhexane,
2,2-bis(4-hydroxyphenyl)hexafluoropropane,
2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)hexafluoropropane,
2,2-bis(4-hydroxy-3-methylphenyl)propane,
2,2-bis(4-hydroxy-3-methylphenyl)butane,
2,2-bis(4-hydroxy-3-isopropylphenyl)propane,
2,2-bis(3-sec-butylphenyl-4-hydroxy)propane,
2,2-bis(4-hydroxy-3-phenylphenyl)propane,
2,2-bis(3-tert-butyl-4-hydroxyphenyl)propane,
2,2-bis(3-fluoro-4-hydroxyphenyl)propane,
2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)propane,
9,9-bis(4-hydroxy-3-methylphenyl)fluorene,
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
3,3-bis(4-hydroxyphenyl)oxindole,
3,3-bis(4-hydroxy-3-methylphenyl)oxindole,
bis(2-hydroxyphenyl)methane,
bis(2-hydroxy-5-methylphenyl)methane,
bis(2-hydroxy-3-hydroxymethyl-5-methyl)methane,
4,4′-[1,4-phenylenebis(1-methylethylidene)]bis(2-methylphenol),
1,1-bis(4-hydroxy-3-phenylphenyl)cyclohexane,
3,3-ethyleneoxydiphenol,
1,4-bis(4-hydroxybenzoate)-3-methylbenzene,
4,4″-dihydroxy-3″-methyl-p-terphenyl,
4,4″-dihydroxy-3″-isopropyl-p-terphenyl,
2,2-dimethyl-1,3-bis(4-hydroxybenzoyloxy)propane,
2,2′-biphenol,
4,4′″-dihydroxy-p-quaterphenyl,
4,4-dihydroxydiphenyl ether,
bis(4-hydroxyphenylthioethyl)ether bis(4-hydroxyphenyl)sulfone,
4-benzyloxy-4'-hydroxydiphenylsulfone,
4-(4-methylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-ethylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-n-propylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-isopropylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-n-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-isobutylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-sec-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(4-tert-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-methylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-ethylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-n-propylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-isopropylbenzyloxy)-4'-dihydroxyphenylsulfone,
4-(3-n-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-isobutylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-sec-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(3-tert-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-methylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-ethylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-n-propylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-isopropylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-n-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-isobutylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-sec-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
4-(2-tert-butylbenzyloxy)-4'-hydroxydiphenylsulfone,
2,4′-dihydroxydiphenyl sulfone,
3,4′-dihydroxydiphenyl sulfone,
4-hydroxydiphenyl sulfone,
4-methyl-4'-hydroxyphenylsulfone,
4-ethyl-4'-hydroxydiphenylsulfone,
4-n-propyl-4'-hydroxydiphenylsulfone,
4-isopropyl-4'-hydroxydiphenylsulfone,
4-chloro-4'-hydroxydiphenylsulfone,
4-fluoro-4'-hydroxydiphenylsulfone,
4-chloro-2-methyl-4'-hydroxydiphenylsulfone,
4-methoxy-4'-hydroxydiphenylsulfone,
4-ethoxy-4'-hydroxydiphenylsulfone,
4-n-propoxy-4'-hydroxydiphenylsulfone,
4-isopropoxy-4'-hydroxydiphenylsulfone,
4-n-butoxy-4'-hydroxydiphenylsulfone,
4-isobutoxy-4'-hydroxydiphenylsulfone,
4-sec-butoxy-4'-hydroxydiphenylsulfone,
4-tert-butoxy-4′-hydroxydiphenylsulfone,
4-n-pentyloxy-4'-hydroxydiphenylsulfone,
4-isopentyloxy-4'-hydroxydiphenylsulfone,
4-(1-propenyloxy)-4'-hydroxydiphenylsulfone,
4-(2-propenyloxy)-4'-hydroxydiphenylsulfone,
4-benzyloxy-4'-hydroxydiphenylsulfone,
4-(β-phenoxyethoxy)-4′-hydroxydiphenylsulfone,
4-(β-phenoxypropoxyl)-4′-hydroxydiphenylsulfone,
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-methyldiphenylsulfone,
3,4,4′-trihydroxydiphenyl sulfone,
bis(3,4-dihydroxyphenyl)sulfone,
2,3,4-trihydroxydiphenyl sulfone,
4-isopropoxy-4'-hydroxydiphenylsulfone,
4-n-propoxy-4'-hydroxydiphenylsulfone,
4-allyloxy-4'-hydroxydiphenylsulfone,
4-benzyloxy-4'-hydroxydiphenylsulfone,
4-(2-propenyloxy)-4'-hydroxydiphenylsulfone,
3-benzyl-4-benzyloxy-4'-hydroxydiphenylsulfone,
3-phenethyl-4-phenethyloxy-4'-hydroxydiphenylsulfone,
3-methylbenzyl-4-methylbenzyloxy-4'-hydroxydiphenylsulfone,
4-benzyloxy-3′-benzyl-4′-hydroxydiphenylsulfone,
4-phenethyloxy-3′-phenethyl-4′-hydroxydiphenylsulfone,
4-methylbenzyloxy-3'-methylbenzyl-4'-hydroxydiphenylsulfone,
α,α'-bis{4-(p-hydroxyphenylsulfone)phenoxy}-p-xylene,
4,4′-{oxybis(ethylene oxide-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,
Examples include 1,8-bis(4-hydroxyphenylthio)-3,6-dioxaoctane.

Examples of compounds having three phenolic hydroxyl groups include pyrogallol, phloroglucinol, phloroglucinol carboxylic acid, gallic acid, octyl gallate, and dodecyl gallate.

Furthermore, as trisphenol compounds, for example,
4,4′,4″-methylidyne trisphenol,
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″-ethylidine trisphenol,
4,4′,4″-ethylidine tris(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-hydroxysiphenyl)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-hydroxylphenyl)-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″-methylidyne trisphenol,
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-hydroxylophenyl)-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″-methylidinetris(2,6-dimethylphenol),
α-(4-hydroxy-3-methylphenyl)-α,α'-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
α′-(4-hydroxy-3-methylphenyl)-α,α-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
α,α-bis(4-hydroxy-3-methylphenyl)-α'-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
α,α'-bis(4-hydroxy-3-methylphenyl)-α-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene,
1,1-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)-1-methylpropyl]cyclohexane,
2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-4-ethylphenol,
1,1′-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane,
1,1′-bis(4-hydroxy-3-methylphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane,
1,1′-bis(3,5-dimethyl-4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane,
1-(4-hydroxyphenyl)-1-[4,4-bis(4-hydroxyphenyl)cyclohexyl]-4-isopropylcyclohexane,
4,4′-[3-(2,5-dimethyl-4-hydroxyphenyl)butylene]bis(2,5-dimethylphenol),
1,3,5-tri(4-hydroxy-3-phenylphenyl)adamantane,
1,3,5-tri(3-cyclohexyl-4-hydroxyphenyl)adamantane,
2,4-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-4-cyclohexylphenol,
2,4-bis[(3-cyclohexyl-4-hydroxyphenyl)methyl]-6-methylphenol,
2,4-bis[(4-hydroxy-2,3,5-trimethylphenyl)methyl]-6-cyclohexylphenol,
2,6-bis[(5-fluoro-2-hydroxyphenyl)methyl]-4-fluorophenol,
2,6-bis[(3-fluoro-4-hydroxyphenyl)methyl]-4-fluorophenol,
2,4-bis[(3-fluoro-4-hydroxyphenyl)methyl]-6-methylphenol,
4,4′-[3-(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-biphenylpropylidene]bis(5-cyclohexyl-2-methylphenol),
4,4′-[3-(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropylidene]bis(2,5-dimethylphenol),
2,4-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-6-methylphenol,
1,1,2-tris(4-hydroxyphenyl)ethane,
1,1,3-tris(4-hydroxyphenyl)propane,
1,1,4-tris(4-hydroxyphenyl)butane,
1,2,2-tris(4-hydroxyphenyl)propane,
1,2,2-tris(4-hydroxyphenyl)butane,
1,2,2-tris(4-hydroxyphenyl)pentane,
1,2,2-tris(4-hydroxyphenyl)hexane,
1,2,2-tris(4-hydroxyphenyl)heptane,
1,2,2-tris(4-hydroxyphenyl)octane,
1,2,2-tris(4-hydroxyphenyl)-3-methylbutane 1,2,2-tris(4-hydroxyphenyl)-3,3-dimethylbutane,
1,2,2-tris(4-hydroxyphenyl)-4,4-dimethylpentane,
1,3,3-tris(4-hydroxyphenyl)butane,
1,3,3-tris(4-hydroxyphenyl)pentane,
1,3,3-tris(4-hydroxyphenyl)hexane,
1,3,3-tris(4-hydroxyphenyl)heptane,
1,3,3-tris(4-hydroxyphenyl)octane,
1,3,3-tris(4-hydroxyphenyl)nonane,
1,4,4-tris(4-hydroxyphenyl)pentane,
1,4,4-tris(4-hydroxyphenyl)hexane,
1,4,4-tris(4-hydroxyphenyl)heptane,
1,4,4-tris(4-hydroxyphenyl)octane,
1,4,4-tris(4-hydroxyphenyl)nonane,
1,4,4-tris(4-hydroxyphenyl)decane,
1,2,2-tris(2-hydroxyphenyl)propane,
1,1,2-tris(3-hydroxyphenyl)propane,
1-(4-hydroxyphenyl)-2,2-bis(2-hydroxyphenyl)propane,
1,2,2-tris(3-fluoro-4-hydroxyphenyl)propane,
1,2,2-tris(3-chloro-4-hydroxyphenyl)propane,
1,2,2-tris(3-bromo-4-hydroxyphenyl)propane,
2,2-bis(3-ethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane,
2,2-bis(3-tert-butyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane,
2,2-bis(2-hydroxy-3-biphenylyl)-1-(4-hydroxyphenyl)propane,
2,2-bis(3-trifluoromethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane,
2-(3-methyl-4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)propane,
1-(3-methyl-4-hydroxyphenyl)-2,2-bis(4-hydroxyphenyl)propane,
3-(3-methyl-4-hydroxyphenyl)-1,3-bis(4-hydroxyphenyl)butane,
1-(3-methyl-4-hydroxyphenyl)-3,3-bis(4-hydroxyphenyl)butane,
4-(3-methyl-4-hydroxyphenyl)-1,4-bis(4-hydroxyphenyl)pentane,
1-(3-methyl-4-hydroxyphenyl)-4,4-bis(4-hydroxyphenyl)pentane,
1,2-bis(3-methyl-4-hydroxyphenyl)-2-(4-hydroxyphenyl)propane,
3,3-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)butane,
1,3-bis(3-methyl-4-hydroxyphenyl)-3-(4-hydroxyphenyl)butane,
4,4-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)pentane,
1,4-bis(3-methyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)pentane,
1,1,2-tris(3-methyl-4-hydroxyphenyl)ethane,
1,2,2-tris(3-methyl-4-hydroxyphenyl)propane,
1,1,3-tris(3-methyl-4-hydroxyphenyl)propane,
1,3,3-tris(3-methyl-4-hydroxyphenyl)butane,
1,1,4-tris(3-methyl-4-hydroxyphenyl)butane,
1,4,4-tris(3-methyl-4-hydroxyphenyl)pentane,
4,4′-[4-(4-hydroxyphenyl)-sec-butylidene]bis(2-methylphenol)
etc. can be exemplified.

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

Examples of carboxylic acids and derivatives thereof include
3,5-di(α-methylbenzyl)salicylic acid,
4-(2-p-methoxyphenyloxyethoxy)salicylic acid,
4-hydroxyphenylbenzoic acid,
4-chlorobenzoic acid,
4-[2-(p-methoxyphenoxy)ethyloxy]salicylic acid,
4-[3-(p-tolylsulfonyl)propyloxy]salicylic acid,
5-[p-(2-p-methoxyphenoxyethoxy)cumyl]salicylic acid,
4-octyloxycarbonylaminosalicylic acid,
3,5-distyrenated salicylic acid,
N-(p-toluenesulfonyl)-glycine,
N-(p-toluenesulfonyl)-alanine,
N-(p-toluenesulfonyl)-β-alanine,
N-phenylaminocarbonyl-glycine,
N-phenylaminocarbonyl-valine,
N-(m-tolylaminocarbonyl)-phenylalanine,
N-(m-tolylaminocarbonyl)-cysteine-S-benzyl,
N-(m-tolylaminocarbonyl)-methionine,
N-(m-tolylaminocarbonyl)-tyrosine,
N-(p-tolylaminocarbonyl)-phenylalanine,
N-(p-tolylaminocarbonyl)-cysteine-S-benzyl,
N-(p-tolylaminocarbonyl)-methionine,
N-(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,
Examples include 2-O-(phenethylaminocarbonyl)-lactic acid and the like.

Acidic phosphoric ester compounds include, for example, 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, tetracosylate. Examples include luacid phosphate, monobutyl phosphate, dibutyl phosphate, monoisodecyl phosphate, bis(2-ethylhexyl) phosphate and the like.

As the component (b), a compound having a phenolic hydroxyl group is preferable because it can more effectively express the heat discoloration property. , acidic phosphates and their metal salts, and 1,2,3-triazoles and their derivatives.

The (c) component of the reaction medium that reversibly causes the electron transfer reaction by the (a) component and the (b) component in a specific temperature range will be explained.
Component (c) includes alcohols, esters, ketones, ethers, and acid amides.
When the reversible thermochromic composition of the present invention is applied to microencapsulation and secondary processing, since low molecular weight compounds evaporate out of the capsules when subjected to high heat treatment, A compound having 10 or more carbon atoms is preferably used.

As alcohols, aliphatic monohydric saturated alcohols having 10 or more carbon atoms are effective. Examples include heptadecyl alcohol, octadecyl alcohol, eicosyl alcohol, and docosyl alcohol.

As esters, esters having 10 or more carbon atoms are effective, and any combination of monohydric carboxylic acid having aliphatic and alicyclic or aromatic ring and monohydric alcohol having aliphatic and alicyclic or aromatic ring Esters obtained from any combination of polycarboxylic acids having aliphatic and alicyclic or aromatic rings and monohydric alcohols having aliphatic and alicyclic or aromatic rings, aliphatic and alicyclic Alternatively, esters obtained from any combination of a monovalent carboxylic acid having an aromatic ring and a polyhydric alcohol having an aliphatic and alicyclic or aromatic ring, such as ethyl caprylate, octyl caprylate, and stearyl caprylate. , myristyl caprate, docosyl caprate, 2-ethylhexyl laurate, n-decyl laurate, 3-methylbutyl myristate, cetyl myristate, isopropyl palmitate, neopentyl palmitate, nonyl palmitate, cyclohexyl palmitate, stearic acid n -butyl, 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, 4-tert-butyl stearyl benzoate, dimyristyl phthalate, distearyl phthalate, dimyristyl oxalate, dicetyl oxalate, dicetyl malonate, dilauryl succinate, dilauryl glutarate, diundecyl adipate , dilauryl azelate, di-(n-nonyl) sebacate, dineopentyl 1,18-octadecylmethylenedicarboxylate, ethylene glycol dimyristate, propylene glycol dilaurate, propylene glycol distearate, hexylene glycol dipalmitate, 1, 5-pentanediol distearate, 1,2,6-hexanetriol trimyristate, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanedimethanol dimyristate, xylene glycol dicaprinate, xylene glycol distearate A rate etc. can be illustrated.

Also, esters of saturated fatty acids and branched fatty alcohols, esters of unsaturated fatty acids or branched or substituted saturated fatty acids with branched or C 16 or more fatty alcohols, cetyl butyrate, Ester compounds selected from 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 caprate, 3,5,5-trimethylhexyl laurate, and 3,5,5 palmitic acid. -trimethylhexyl, 3,5,5-trimethylhexyl stearate, 2-methylbutyl caproate, 2-methylbutyl caprylate, 2-methylbutyl caprate, 1-ethylpropyl palmitate, 1-ethylpropyl stearate, 1 behenic acid - ethyl propyl, 1-ethylhexyl laurate, 1-ethylhexyl myristate, 1-ethylhexyl palmitate, 2-methylpentyl caproate, 2-methylpentyl caprylate, 2-methylpentyl caprate, 2-methylpentyl laurate, 2-methylbutyl stearate, 2-methylbutyl stearate, 3-methylbutyl stearate, 1-methylheptyl stearate, 2-methylbutyl behenate, 3-methylbutyl behenate, 1-methylheptyl stearate, 1-methylheptyl behenate , 1-ethylpentyl caproate, 1-ethylpentyl palmitate, 1-methylpropyl stearate, 1-methyloctyl stearate, 1-methylhexyl stearate, 1,1-dimethylpropyl laurate, 1-methyl caprate Pentyl, 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, iso-erucate Stearyl, cetyl isostearate, stearyl isostearate, 2-methylpentyl 12-hydroxystearate, 2-ethylhexyl 18-bromostearate, isostearyl 2-ketomyristate, 2-ethylhexyl 2-fluoromyristate, cetyl butyrate, butyric acid Examples include stearyl and behenyl butyrate.

Furthermore, in order to discolor with a large hysteresis characteristic with respect to the color density-temperature curve and to provide color memory depending on temperature change, a temperature of 5 ° C. or more and less than 50 ° C. described in JP-B-4-17154 is used. Carboxylic acid ester compounds exhibiting a ΔT value (melting point - clouding point), for example, a carboxylic acid ester containing a substituted aromatic ring in the molecule, a carboxylic acid containing an unsubstituted aromatic ring, and an aliphatic alcohol having 10 or more carbon atoms Esters, carboxylic acid esters containing a cyclohexyl group in the molecule, esters of fatty acids with 6 or more carbon atoms and unsubstituted aromatic alcohols or phenols, esters of fatty acids with 8 or more carbon atoms and branched aliphatic alcohols, dicarboxylic acids and aromatics Esters with tribal or branched aliphatic alcohols, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, di Examples include myristin, distearin, and the like.

Further, a fatty acid ester compound obtained from an odd aliphatic monohydric alcohol having 9 or more carbon atoms and an even aliphatic carboxylic acid having an even number of carbon atoms, n-pentyl alcohol or n-heptyl alcohol, and an even number having 10 to 16 carbon atoms A fatty acid ester compound having a total carbon number of 17-23 obtained from an aliphatic carboxylic acid is 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, capryl n-undecyl acid, n-tridecyl caprylate, n-pentadecyl caprylate, n-heptyl caprate, n-nonyl caprate, n-undecyl caprate, n-tridecyl caprate, n-pentadecyl caprate, n-laurate -pentyl, 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, palmitin n-pentadecyl acid, n-nonyl stearate, n-undecyl stearate, n-tridecyl stearate, n-pentadecyl stearate, n-nonyl eicosanoate, n-undecyl eicosanoate, n-tridecyl eicosanoate, n-eicosanoate -pentadecyl, n-nonyl behenate, n-undecyl behenate, n-tridecyl behenate, n-pentadecyl behenate and the like.

Effective ketones are aliphatic ketones having a total carbon number of 10 or more, such as 2-decanone, 3-decanone, 4-decanone, 2-undecanone, 3-undecanone, 4-undecanone, and 5-undecanone. , 2-dodecanone, 3-dodecanone, 4-dodecanone, 5-dodecanone, 2-tridecanone, 3-tridecanone, 2-tetradecanone, 2-pentadecanone, 8-pentadecanone, 2-hexadecanone, 3-hexadecanone, 9-heptadecanone, 2 -pentadecanone, 2-octadecanone, 2-nonadecanone, 10-nonadecanone, 2-eicosanone, 11-eicosanone, 2-heneicosanone, 2-docosanone, laurone, stearone and the like.
Furthermore, arylalkyl ketones having a total carbon number of 12 to 24, such as n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradecanophenone. nophenone, 4-n-dodecaacetophenone, n-tridecanophenone, 4-n-undecanoacetophenone, n-laurophenone, 4-n-decanoacetophenone, 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-acetonaphtone, 2-acenaphthone, cyclopentylphenyl A ketone etc. can be illustrated.

Aliphatic ethers having a total carbon number of 10 or more are effective as ethers. , 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. can be exemplified.

Acid amides include, for example, acetamide, propionamide, butyric acid amide, caproic acid amide, caprylic acid amide, capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, olein Acid amide, erucamide, benzamide, caproic acid anilide, caprylic acid anilide, capric acid anilide, lauric acid anilide, myristate anilide, palmitic acid anilide, stearic acid anilide, behenic acid anilide, oleic acid anilide, erucic acid anilide, capron acid N-methylamide, caprylic acid N-methylamide, capric acid N-methylamide, lauric acid N-methylamide, myristate N-methylamide, palmitic acid N-methylamide, stearic acid N-methylamide, behenic acid N-methylamide, oleic acid N -methylamide, erucic acid N-methylamide, lauric acid N-ethylamide, myristate N-ethylamide, palmitic acid N-ethylamide, stearic acid N-ethylamide, oleic acid N-ethylamide, lauric acid N-butylamide, myristate N-butylamide , N-butylamide palmitate, N-butylamide stearate, N-butylamide oleate, N-octylamide laurate, N-octylamide myristate, N-octylamide palmitate, N-octylamide stearate, N-oleic acid - octylamide, lauric acid N-dodecylamide, myristate N-dodecylamide, palmitic acid N-dodecylamide, stearic acid N-dodecylamide, oleic acid N-dodecylamide, dilauric acid amide, dimyristate amide, dipalmitin Acid amide, distearic amide, dioleic amide, trilauric amide, trimyristic amide, tripalmitic amide, tristearic amide, trioleic amide, succinic amide, adipic amide, glutaric amide, malonic amide , azelaic acid amide, maleic acid amide, succinic acid N-methylamide, adipic acid N-methylamide, glutaric acid N-methylamide, malonic acid N-methylamide, azelaic acid N-methylamide, succinic acid N-ethylamide, adipic acid N-ethylamide , glutaric acid N-ethylamide, malonic acid N-ethylamide, azelaic acid N-ethylamide, succinic acid N-butylamide, adipate Examples include acid N-butylamide, glutaric acid N-butylamide, malonic acid N-butylamide, adipic acid N-octylamide, adipic acid N-dodecylamide and the like.

〔式中、Ｒ_１は水素原子又はメチル基を示し、ｍは０～２の整数を示し、Ｘ_１及びＸ_２のいずれか一方は－（ＣＨ_２）_ｎＯＣＯＲ_２又は（ＣＨ_２）_ｎＣＯＯＲ_２、他方は水素原子を示し、ｎは０～２の整数を示し、Ｒ_２は炭素数４以上のアルキル基又はアルケニル基を示し、Ｙ_１及びＹ_２はそれぞれ独立して、水素原子、炭素数１～４のアルキル基、メトキシ基、ハロゲン原子のいずれかを示し、ｒ及びｐはそれぞれ独立して、１～３の整数を示す〕
式（１）で示される化合物のうち、Ｒ_１が水素原子の場合、より広いヒステリシス幅を有する可逆熱変色性組成物が得られるため好ましく、さらにＲ_１が水素原子であり、かつ、ｍが０の場合がより好ましい。
なお、式（１）で示される化合物のうち、より好ましくは下記式（２）で示される化合物である。

（式中、Ｒは炭素数８以上のアルキル基又はアルケニル基を示し、好ましくは炭素数１０～２４のアルキル基であり、より好ましくは炭素数１２～２２のアルキル基である）
式（２）で示される化合物としては、例えば、オクタン酸４－ベンジルオキシフェニルエチル、ノナン酸４－ベンジルオキシフェニルエチル、デカン酸４－ベンジルオキシフェニルエチル、ウンデカン酸４－ベンジルオキシフェニルエチル、ドデカン酸４－ベンジルオキシフェニルエチル、トリデカン酸４－ベンジルオキシフェニルエチル、テトラデカン酸４－ベンジルオキシフェニルエチル、ペンタデカン酸４－ベンジルオキシフェニルエチル、ヘキサデカン酸４－ベンジルオキシフェニルエチル、ヘプタデカン酸４－ベンジルオキシフェニルエチル、オクタデカン酸４－ベンジルオキシフェニルエチル等を例示できる。 Moreover, the compound represented by the following formula (1) may be used as the component (c).

[In the formula, R ₁ represents a hydrogen atom or a methyl group, m represents an integer of 0 to 2, and one of X ₁ and X ₂ is -(CH ₂ ) _n OCOR ₂ or (CH ₂ ) _n COOR ₂ , the other represents a hydrogen atom, n represents an integer of 0 to 2, R ₂ represents an alkyl group or alkenyl group having 4 or more carbon atoms, Y ₁ and Y ₂ each independently represent a hydrogen atom, a carbon an alkyl group, a methoxy group, or a halogen atom of numbers 1 to 4, and r and p each independently represent an integer of 1 to 3]
Among the compounds represented by formula (1), when R ₁ is a hydrogen atom, it is preferable because a reversible thermochromic composition having a wider hysteresis width can be obtained, and further R ₁ is a hydrogen atom and m is 0 is more preferred.
Among the compounds represented by the formula (1), the compounds represented by the following formula (2) are more preferable.

(Wherein, R represents an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, more preferably an alkyl group having 12 to 22 carbon atoms.)
Examples of compounds represented by formula (2) include 4-benzyloxyphenylethyl octanoate, 4-benzyloxyphenylethyl nonanoate, 4-benzyloxyphenylethyl decanoate, 4-benzyloxyphenylethyl undecanoate, and dodecane. 4-benzyloxyphenylethyl acid, 4-benzyloxyphenylethyl tridecanoate, 4-benzyloxyphenylethyl tetradecanoate, 4-benzyloxyphenylethyl pentadecanoate, 4-benzyloxyphenylethyl hexadecanoate, 4-benzyloxy heptadecanoate Examples include phenylethyl, 4-benzyloxyphenylethyl octadecanoate, and the like.

（式中、Ｒは炭素数８以上のアルキル基又はアルケニル基を示し、ｍ及びｎはそれぞれ独立して、１～３の整数を示し、Ｘ及びＹはそれぞれ独立して、水素原子、炭素数１～４のアルキル基、炭素数１～４のアルコキシ基、ハロゲン原子のいずれかを示す）
式（３）で示される化合物としては、例えば、オクタン酸１，１－ジフェニルメチル、ノナン酸１，１－ジフェニルメチル、デカン酸１，１－ジフェニルメチル、ウンデカン酸１，１－ジフェニルメチル、ドデカン酸１，１－ジフェニルメチル、トリデカン酸１，１－ジフェニルメチル、テトラデカン酸１，１－ジフェニルメチル、ペンタデカン酸１，１－ジフェニルメチル、ヘキサデカン酸１，１－ジフェニルメチル、ヘプタデカン酸１，１－ジフェニルメチル、オクタデカン酸１，１－ジフェニルメチル等を例示できる。 Furthermore, a compound represented by the following formula (3) may be used as the component (c).

(Wherein, R represents an alkyl group or alkenyl group having 8 or more carbon atoms, m and n each independently represents an integer of 1 to 3, X and Y each independently represent a hydrogen atom, a carbon number 1 to 4 alkyl groups, C 1 to 4 alkoxy groups, or halogen atoms)
Examples of compounds represented by formula (3) include 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, and dodecane. 1,1-diphenylmethyl acid, 1,1-diphenylmethyl tridecanoate, 1,1-diphenylmethyl tetradecanoate, 1,1-diphenylmethyl pentadecanoate, 1,1-diphenylmethyl hexadecanoate, 1,1-heptadecanoate Examples include diphenylmethyl, 1,1-diphenylmethyl octadecanoate, and the like.

（式中、Ｘは水素原子、炭素数１～４のアルキル基、メトキシ基、ハロゲン原子のいずれかを示し、ｍは１～３の整数を示し、ｎは１～２０の整数を示す）
式（４）で示される化合物としては、例えば、マロン酸と２－〔４－（４－クロロベンジルオキシ）フェニル〕エタノールとのジエステル、こはく酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、こはく酸と２－〔４－（３－メチルベンジルオキシ）フェニル〕エタノールとのジエステル、グルタル酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、グルタル酸と２－〔４－（４－クロロベンジルオキシ）フェニル〕エタノールとのジエステル、アジピン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、ピメリン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、スベリン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、スベリン酸と２－〔４－（３－メチルベンジルオキシ）フェニル〕エタノールとのジエステル、スベリン酸と２－〔４－（４－クロロベンジルオキシ）フェニル〕エタノールとのジエステル、スベリン酸と２－〔４－（２，４－ジクロロベンジルオキシ）フェニル〕エタノールとのジエステル、アゼライン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、セバシン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、１，１０－デカンジカルボン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、１，１８－オクタデカンジカルボン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、１，１８－オクタデカンジカルボン酸と２－〔４－（２－メチルベンジルオキシ）フェニル〕エタノールとのジエステル等を例示できる。 Furthermore, a compound represented by the following formula (4) may be used as the component (c).

(Wherein, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom, m represents an integer of 1 to 3, and n represents an integer of 1 to 20)
Examples of the compound represented by formula (4) include diesters of malonic acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, and succinic acid and 2-(4-benzyloxyphenyl)ethanol. Diesters, diesters of succinic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol, diesters of glutaric acid and 2-(4-benzyloxyphenyl)ethanol, glutaric acid and 2-[4-( 4-chlorobenzyloxy)phenyl]ethanol, diester of adipic acid with 2-(4-benzyloxyphenyl)ethanol, diester of pimelic acid with 2-(4-benzyloxyphenyl)ethanol, suberic acid with 2-(4-benzyloxyphenyl)ethanol diester, diester of suberic acid with 2-[4-(3-methylbenzyloxy)phenyl]ethanol, suberic acid with 2-[4-(4-chlorobenzyloxy ) phenyl] ethanol, diester of suberic acid with 2-[4-(2,4-dichlorobenzyloxy)phenyl]ethanol, diester of azelaic acid with 2-(4-benzyloxyphenyl)ethanol, sebacine diester of acid with 2-(4-benzyloxyphenyl)ethanol, diester of 1,10-decanedicarboxylic acid with 2-(4-benzyloxyphenyl)ethanol, 1,18-octadecanedicarboxylic acid with 2-(4 -benzyloxyphenyl)ethanol, diesters of 1,18-octadecanedicarboxylic acid and 2-[4-(2-methylbenzyloxy)phenyl]ethanol, and the like.

（式中、Ｒは炭素数１～２１のアルキル基又はアルケニル基を示し、ｎは１～３の整数を示す）
式（５）で示される化合物としては、例えば、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとカプリン酸とのジエステル、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとウンデカン酸とのジエステル、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとラウリン酸とのジエステル、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとミリスチン酸とのジエステル、１，４－ビス（ヒドロキシメトキシ）ベンゼンと酪酸とのジエステル、１，４－ビス（ヒドロキシメトキシ）ベンゼンとイソ吉草酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンと酢酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとプロピオン酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンと吉草酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとカプロン酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとカプリル酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとカプリン酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとラウリン酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとミリスチン酸とのジエステル等を例示できる。 Furthermore, a compound represented by the following formula (5) may be used as the component (c).

(Wherein, R represents an alkyl or alkenyl group having 1 to 21 carbon atoms, and n represents an integer of 1 to 3)
Examples of the compound represented by formula (5) include a diester of 1,3-bis(2-hydroxyethoxy)benzene and capric acid and a diester of 1,3-bis(2-hydroxyethoxy)benzene and undecanoic acid. , a diester of 1,3-bis(2-hydroxyethoxy)benzene and lauric acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and myristic acid, a diester of 1,4-bis(hydroxymethoxy)benzene and Diesters with butyric acid, diesters of 1,4-bis(hydroxymethoxy)benzene with isovaleric acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene with acetic acid, 1,4-bis(2-hydroxy ethoxy)benzene with propionic acid, 1,4-bis(2-hydroxyethoxy)benzene with valeric acid, 1,4-bis(2-hydroxyethoxy)benzene with caproic acid, 1, Diester of 4-bis(2-hydroxyethoxy)benzene and caprylic acid, diester of 1,4-bis(2-hydroxyethoxy)benzene and capric acid, 1,4-bis(2-hydroxyethoxy)benzene and laurin Examples include diesters with acids, diesters with 1,4-bis(2-hydroxyethoxy)benzene and myristic acid, and the like.

（式中、Ｘは水素原子、炭素数１～４のアルキル基、炭素数１～４のアルコキシ基、ハロゲン原子のいずれかを示し、ｍは１～３の整数を示し、ｎは１～２０の整数を示す）
式（６）で示される化合物としては、例えば、こはく酸と２－フェノキシエタノールとのジエステル、スベリン酸と２－フェノキシエタノールとのジエステル、セバシン酸と２－フェノキシエタノールとのジエステル、１，１０－デカンジカルボン酸と２－フェノキシエタノールとのジエステル、１，１８－オクタデカンジカルボン酸と２－フェノキシエタノールとのジエステル等を例示できる。 Furthermore, a compound represented by the following formula (6) may be used as the component (c).

(Wherein, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom; m represents an integer of 1 to 3; n represents 1 to 20 indicates an integer of
Examples of the compound represented by formula (6) include a diester of succinic acid and 2-phenoxyethanol, a diester of suberic acid and 2-phenoxyethanol, a diester of sebacic acid and 2-phenoxyethanol, and 1,10-decanedicarboxylic acid. and 2-phenoxyethanol, and diesters of 1,18-octadecanedicarboxylic acid and 2-phenoxyethanol.

（式中、Ｒは炭素数４～２２のアルキル基、シクロアルキルアルキル基、シクロアルキル基、炭素数４～２２のアルケニル基のいずれかを示し、Ｘは水素原子、炭素数１～４のアルキル基、炭素数１～４のアルコキシ基、ハロゲン原子のいずれかを示し、ｎは０又は１を示す）
式（７）で示される化合物としては、例えば、４－フェニル安息香酸デシル、４－フェニル安息香酸ラウリル、４－フェニル安息香酸ミリスチル、４－フェニル安息香酸シクロヘキシルエチル、４－ビフェニル酢酸オクチル、４－ビフェニル酢酸ノニル、４－ビフェニル酢酸デシル、４－ビフェニル酢酸ラウリル、４－ビフェニル酢酸ミリスチル、４－ビフェニル酢酸トリデシル、４－ビフェニル酢酸ペンタデシル、４－ビフェニル酢酸セチル、４－ビフェニル酢酸シクロペンチル、４－ビフェニル酢酸シクロヘキシルメチル、４－ビフェニル酢酸ヘキシル等を例示できる。 Furthermore, a compound represented by the following formula (7) may be used as the component (c).

(Wherein, R represents an alkyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, a cycloalkyl group, or an alkenyl group having 4 to 22 carbon atoms, X is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, group, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, and n is 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, 4- nonyl biphenylacetate, decyl 4-biphenylacetate, lauryl 4-biphenylacetate, myristyl 4-biphenylacetate, tridecyl 4-biphenylacetate, pentadecyl 4-biphenylacetate, cetyl 4-biphenylacetate, cyclopentyl 4-biphenylacetate, 4-biphenylacetate Examples include cyclohexylmethyl, hexyl 4-biphenylacetate, and the like.

（式中、Ｒは炭素数３～１８のアルキル基又は炭素数３～１８の脂肪族アシル基を示し、Ｘは水素原子、炭素数１～３のアルキル基、炭素数１又は２のアルコキシ基、ハロゲン原子のいずれかを示し、Ｙは水素原子又はメチル基を示し、Ｚは水素原子、炭素数１～４のアルキル基、炭素数１又は２のアルコキシ基、ハロゲン原子のいずれかを示す）
式（８）で示される化合物としては、例えば、４－ブトキシ安息香酸フェノキシエチル、４－ペンチルオキシ安息香酸フェノキシエチル、４－テトラデシルオキシ安息香酸フェノキシエチル、４－ヒドロキシ安息香酸フェノキシエチルとドデカン酸とのエステル、バニリン酸フェノキシエチルのドデシルエーテル等を例示できる。 Furthermore, a compound represented by the following formula (8) may be used as the component (c).

(Wherein, R represents an alkyl group having 3 to 18 carbon atoms or an aliphatic acyl group having 3 to 18 carbon atoms, X represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms , a halogen atom, Y represents a hydrogen atom or a methyl group, Z represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a halogen atom)
Examples of compounds represented by formula (8) include phenoxyethyl 4-butoxybenzoate, phenoxyethyl 4-pentyloxybenzoate, phenoxyethyl 4-tetradecyloxybenzoate, phenoxyethyl 4-hydroxybenzoate and dodecanoic acid. and dodecyl ether of phenoxyethyl vanillate.

（式中、Ｒは炭素数４～２２のアルキル基、炭素数４～２２のアルケニル基、シクロアルキルアルキル基、シクロアルキル基のいずれかを示し、Ｘは水素原子、アルキル基、アルコキシ基、ハロゲン原子のいずれかを示し、Ｙは水素原子、アルキル基、アルコキシ基、ハロゲン原子のいずれかを示し、ｎは０又は１を示す）
式（９）で示される化合物としては、例えば、４－ヒドロキシ安息香酸オクチルの安息香酸エステル、４－ヒドロキシ安息香酸デシルの安息香酸エステル、４－ヒドロキシ安息香酸ヘプチルの４－メトキシ安息香酸エステル、４－ヒドロキシ安息香酸ドデシルの２－メトキシ安息香酸エステル、４－ヒドロキシ安息香酸シクロヘキシルメチルの安息香酸エステル等を例示できる。 Furthermore, a compound represented by the following formula (9) may be used as the component (c).

(Wherein, R represents an alkyl group having 4 to 22 carbon atoms, an alkenyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, or a cycloalkyl group, and X represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, Y is a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, and n is 0 or 1)
Examples of the compound represented by formula (9) include benzoate of octyl 4-hydroxybenzoate, decyl 4-hydroxybenzoate, 4-methoxy benzoate of heptyl 4-hydroxybenzoate, 4 2-methoxybenzoate of dodecyl-hydroxybenzoate, benzoate of cyclohexylmethyl-4-hydroxybenzoate, and the like can be exemplified.

（式中、Ｒは炭素数３～１８のアルキル基、炭素数６～１１のシクロアルキルアルキル基、炭素数５～７のシクロアルキル基、炭素数３～１８のアルケニル基のいずれかを示し、Ｘは水素原子、炭素数１～４のアルキル基、炭素数１～３のアルコキシ基、ハロゲン原子のいずれかを示し、Ｙは水素原子、炭素数１～４のアルキル基、メトキシ基、エトキシ基、ハロゲン原子のいずれかを示す）
式（１０）で示される化合物としては、例えば、４－ヒドロキシ安息香酸ノニルのフェノキシエチルエーテル、４－ヒドロキシ安息香酸デシルのフェノキシエチルエーテル、４－ヒドロキシ安息香酸ウンデシルのフェノキシエチルエーテル、バニリン酸ドデシルのフェノキシエチルエーテル等を例示できる。 Further, the component (c) may be a compound represented by the following formula (10).

(Wherein, R is 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, or an alkenyl group having 3 to 18 carbon atoms, X is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a halogen atom; Y is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or an ethoxy group; , indicates one of the halogen atoms)
Examples of the compound represented by formula (10) include phenoxyethyl ether of nonyl 4-hydroxybenzoate, phenoxyethyl ether of decyl 4-hydroxybenzoate, phenoxyethyl ether of undecyl 4-hydroxybenzoate, and dodecyl vanillate. Phenoxyethyl ether etc. can be illustrated.

（式中、Ｒは炭素数３～８のシクロアルキル基又は炭素数４～９のシクロアルキルアルキル基を示し、ｎは１～３の整数を示す）
式（１１）で示される化合物としては、例えば、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとシクロヘキサンカルボン酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとシクロヘキサンプロピオン酸とのジエステル、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとシクロヘキサンプロピオン酸とのジエステル等を例示できる。 Furthermore, a compound represented by the following formula (11) may be used as the component (c).

(Wherein, 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, and 1,4-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid. and diesters of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid.

（式中、Ｒは炭素数３～１７のアルキル基、炭素数３～８のシクロアルキル基、炭素数５～８のシクロアルキルアルキル基のいずれかを示し、Ｘは水素原子、炭素数１～５のアルキル基、メトキシ基、エトキシ基、ハロゲン原子のいずれかを示し、ｎは１～３の整数を示す）
式（１２）で示される化合物としては、例えば、４－フェニルフェノールエチレングリコールエーテルとシクロヘキサンカルボン酸とのジエステル、４－フェニルフェノールジエチレングリコールエーテルとラウリン酸とのジエステル、４－フェニルフェノールトリエチレングリコールエーテルとシクロヘキサンカルボン酸とのジエステル、４－フェニルフェノールエチレングリコールエーテルとオクタン酸とのジエステル、４－フェニルフェノールエチレングリコールエーテルとノナン酸とのジエステル、４－フェニルフェノールエチレングリコールエーテルとデカン酸とのジエステル、４－フェニルフェノールエチレングリコールエーテルとミリスチン酸とのジエステル等を例示できる。 Furthermore, a compound represented by the following formula (12) may be used as the component (c).

(Wherein, R is an alkyl group having 3 to 17 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, or a cycloalkylalkyl group having 5 to 8 carbon atoms; X is a hydrogen atom; 5 alkyl group, methoxy group, ethoxy group, or halogen atom, and n is an integer of 1 to 3)
Examples of compounds 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, and 4-phenylphenol triethylene glycol ether. Diesters of 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, 4 - A diester of phenylphenol ethylene glycol ether and myristic acid can be exemplified.

The above reversible thermochromic composition is a compatible body containing the above (a) component, (b) component, and (c) component as essential components, and the ratio of each component is the concentration, color change temperature, color change form Although it depends on the type of each component, generally the component ratio at which the desired properties can be obtained is 0.1 to 100, preferably 0.1 to 50 , more preferably 0.5 to 20, component (c) 5 to 200, preferably 5 to 100, more preferably 10 to 100 (all the above proportions are parts by mass).

Furthermore, various light stabilizers may be added to the reversible thermochromic composition, if necessary.
The light stabilizer is contained to prevent photodegradation of the reversible thermochromic composition consisting of (a) component, (b) component, and (c) component. 0.3 to 24% by mass, preferably 0.3 to 16% by mass. Among the light stabilizers, the ultraviolet absorber effectively cuts ultraviolet rays contained in sunlight or the like, and prevents photodegradation caused by the excited state due to the photoreaction of the component (a). In addition, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers and the like suppress the oxidation reaction caused by light.
The light stabilizer can be used singly or in combination of two or more.

By encapsulating the reversible thermochromic composition in microcapsules to form a reversible thermochromic microcapsule pigment, it is possible to constitute a chemically and physically stable pigment. , the reversible thermochromic composition has the same composition and exhibits the same effect.
Microencapsulation of microcapsule pigments is performed by conventionally known isocyanate-based interfacial polymerization methods, melamine-formalin-based in situ polymerization methods, in-liquid curing coating methods, phase separation methods from aqueous solutions, and phase separation methods from organic solvents. , the melting dispersion cooling method, the aerial suspension coating method, the spray drying method, and the like, which are appropriately selected according to the application. Examples of materials for the capsule include epoxy resin, urea resin, urethane resin, isocyanate resin, and the like.
Furthermore, depending on the purpose, the surface of the microcapsules can be provided with a secondary resin film to impart durability, or the surface characteristics can be modified for practical use.
The reversible thermochromic microcapsule pigment preferably has a mass ratio of inclusions to wall film of 7:1 to 1:1. This prevents loss of color density and sharpness over time. More preferably, the mass ratio of inclusions:wall membrane is from 6:1 to 1:1.
When the ratio of the inclusions to the wall film exceeds the above range, the wall film of the microcapsule pigment becomes thin and easily destroyed by heat and pressure. On the other hand, when the ratio of the wall film to the inclusions exceeds the above range, the color density and vividness during color development tend to decrease.

In addition, when a non-thermochromic colorant such as a general dye or pigment is blended in the microcapsule pigment, the color change behavior from colored (1) to colored (2) is exhibited.

The average particle size of the microcapsule pigment is preferably 0.01 to 5 μm, more preferably 0.05 to 4 μm, even more preferably 0.1 to 3 μm, particularly preferably 0.5 to 3 μm. When the average particle size of the microcapsule pigment exceeds 5 μm, it becomes difficult to obtain good ink ejection properties when used in writing instruments. On the other hand, if the average particle size is less than 0.01 μm, it becomes difficult to exhibit high density color development.
In addition, the average particle size is measured by determining the area of the particles with image analysis type particle size distribution measurement software [manufactured by Mountec Co., Ltd., product name: Macview], and calculating the area of the area of the particles to determine the projected area circle equivalent diameter ( Heywood diameter) is calculated, and the average particle diameter of particles equivalent to a sphere of equal volume is measured as the value.
In addition, when the particle diameter of all or most of the particles exceeds 0.2 μm, a particle size distribution measuring device [manufactured by Beckman Coulter, Inc., product name: Multisizer 4e] is used to obtain isovolumetric spheres by the Coulter method. It can also be measured as the average particle size of the equivalent particles.
Furthermore, a laser diffraction/scattering particle size distribution measuring device [manufactured by Horiba, Ltd., product name: LA- 300], the volume-based particle size and average particle size may be measured.

In the present invention, the content of the reversible thermochromic microcapsule pigment (hereinafter sometimes referred to as “P _MC ”) is 5 to 40% by mass, preferably 10 to 40%, relative to the total mass of the ink composition. % by weight, more preferably in the range of 15 to 35% by weight. When the content of the microcapsule pigment exceeds 40% by mass, the viscosity of the ink composition tends to increase, and the ink ejection property of the ballpoint pen containing the ink composition tends to decrease, and the writing performance tends to be impaired. On the other hand, if the content is less than 5% by mass, it is difficult to obtain a suitable discoloration property and a suitable handwriting density for a ballpoint pen, and it becomes difficult to sufficiently satisfy the discoloration function.
In general, when the ink composition is used for applications such as ballpoint pens, the amount of the colorant compounded is less than 10% by mass with respect to the total mass of the ink composition. In order to achieve sufficient color density, it is preferable to increase the amount of pigment blended. When the blending amount of the pigment is increased, the proportion of solids in the ink composition (solids content) increases, and the writing tip tends to dry out, resulting in poor dry-up resistance. However, the ink composition according to the present invention is excellent in dry-up resistance performance by containing the N-vinyl-2-pyrrolidone polymer described later, and the content of the microcapsule pigment in the ink composition is high. In particular, even when the microcapsule pigment is contained in an amount of 18% by mass or more relative to the total mass of the ink composition, it is possible to suppress drying at the writing tip and form good handwriting.

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 completing various properties at the same time. have the effect of improving Furthermore, an ink composition containing a microcapsule pigment has the effect of improving dry-up resistance.
For example, when the ink composition is used in a ballpoint pen, particularly a retractable ballpoint pen, the tip of the pen (pen tip) is placed in an environment that is prone to dryness, so writing defects such as faintness and line skipping are likely to occur and writing becomes impossible. Sometimes. A state in which the pen tip is dried is called dry-up, and an ink composition using a specific PVP can suppress dry-up and achieve excellent writing performance.

PVP applied to the present invention is polymerized from N-vinyl-2-pyrrolidone and has a weight average molecular weight of 3,000 to 2,000,000. The weight average molecular weight is preferably in the range of 3,000 to 1,700,000, more preferably in the range of 3,000 to 1,000,000. When the mass-average molecular weight of PVP is within the above range, an increase in the viscosity of the ink composition and aggregation of the microcapsule pigment when a medium such as water in the ink composition volatilizes can be suppressed, and resistance can be improved. It becomes easy to obtain an ink composition having excellent dry-up performance.
PVP is not particularly limited as long as it has a mass average molecular weight in the range of 3,000 to 2,000,000, and can be produced by a known polymerization method. Examples of the polymerization method include a method of polymerizing N-vinyl-2-pyrrolidone in the presence of an initiator.
Moreover, a commercial item can also be used as PVP. Specifically, manufactured by BASF, product names: Sokalan K17P (mass average molecular weight: 9,000), Sokalan K30P (mass average molecular weight: 50,000), Sokalan K80P (mass average molecular weight: 850,000), Sokalan K85P (mass average molecular weight: 1,100,000), same K90P (mass average molecular weight: 1,400,000), manufactured by ASHLAND, product name: PVP K-12 (mass average molecular weight: 4,000 to 6,000), same K-15 ( Mass average molecular weight: 6,000 to 15,000), Same K-30 (mass average molecular weight: 40,000 to 80,000), Same K-60 (mass average molecular weight: 390,000 to 470,000), Same K-85 (mass average molecular weight: 900,000 to 1,200,000), K-90 (mass average molecular weight: 1,000,000 to 1,700,000), manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Pitz Call K-17 ( Mass average molecular weight: 9,000), Same K-30 (mass average molecular weight: 45,000), Same K-30A (mass average molecular weight: 45,000), Same K-50 (mass average molecular weight: 250,000) , K-80 (mass average molecular weight: 900,000), K-85 (mass average molecular weight: 1,000,000), K-90 (mass average molecular weight: 1,200,000), and the like.
The weight average molecular weight can be calculated by GPC (gel permeation chromatography) in accordance with JIS K7252-1.

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 0.1 to 10% by mass, more preferably 0.5 to 6.0% by mass. It is in the range of 5% by mass. When the content of PVP is within the above range, excellent dry-up resistance can be maintained, good ink discharge from the pen tip can be maintained, and high handwriting density can be achieved.

In the present invention, the microcapsule pigment content (P _MC ) and the PVP content (P _PVP ) preferably satisfy the following formula (13).
3≦P _MC /P _PVP ≦60 (13)
P _MC /P _PVP more preferably satisfies 3.5≦P _MC /P _PVP ≦40. When P _MC /P _PVP is within the above range, even when a microcapsule pigment is used as the colorant of the ink composition, it is easy to obtain an ink composition that has excellent dry-up resistance and excellent writing performance. becomes.
In general, when the ink composition is used for applications such as ballpoint pens, the amount of the colorant compounded is less than 10% by mass with respect to the total mass of the ink composition. It is preferable to increase the blending amount in order to realize sufficient color development. In general, an ink composition containing a large amount of microcapsule pigment has a higher solids content (solids content) than general inks, and is inferior in dry-up resistance. It becomes easier. However, in the present invention, such problems can be solved by blending the microcapsule pigment and PVP in a specific ratio.

The ink composition according to the present invention further comprises a shear thinning agent.
The shear thinning property is a property that the viscosity is high when left standing, and the viscosity decreases when a shearing stress is applied. Some ballpoint pens contain an ink composition commonly referred to as gel ink. Gel ink is highly viscous when it is not subjected to shear stress, so it is stably retained in the ballpoint pen. As a result, the ink is ejected from the gap between the ball and the ball container and adheres to the non-writing surface. By including a shear thinning 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 pigment, and can suppress the bleeding of the handwriting, so that it is possible to form a good handwriting. In addition, ballpoint pens containing gel ink can prevent ink from leaking from the gap between the ball and the tip when not in use, and prevent ink from flowing back when the writing tip is left facing upward (upright position). can.

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

Examples of water-soluble polysaccharides include xanthan gum, welan gum, zeta sea gum, diutan gum, macrohomopsis gum, and succinoglycan (average molecular weight of about 1 million to 8 million), guar gum, locust bean gum and its derivatives, hydroxyethylcellulose, alginic acid alkyl esters, glucomannan, carbohydrates with gelling ability extracted from seaweed such as agar and carrageenin.
Among these, succinoglycan or xanthan gum is preferable because it has a large shear-thinning effect, and succinoglycan is more preferable because it has excellent dispersion stability of the microcapsule pigment. A succinoglycan having an average molecular weight of about 1,000,000 to 8,000,000 is preferably used.

When the ink composition according to the present invention contains succinoglycan or xanthan gum, the content of succinoglycan or xanthan gum is preferably in the range of 0.01 to 1% by weight relative to the total weight of the ink composition. When the content of succinoglycan or xanthan gum is within the above range, it is possible to maintain a high level of ink jettability from the nib and to suppress aggregation of the microcapsule pigment.

The ink composition according to the invention further comprises water.
Water is not particularly limited, and examples thereof include tap water, ion-exchanged water, ultrafiltered water, and distilled water.
The water content is preferably in the range of 30 to 80% by mass, more preferably 40 to 70% by mass, relative to the total mass of the ink composition.

In the ink composition according to the present invention, in addition to the essential components described above, optional components can be combined within a range that does not impair the effects of the present invention.

A surfactant can be blended in the ink composition according to the present invention.
Surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and the like, and any of them can be suitably used.
Examples of surfactants include phosphate ester surfactants, silicone surfactants, surfactants having an acetylene bond in their structure, fluorine surfactants, and the like. It is appropriately selected according to the component and application of the product.
For example, when the ink composition is used in a water-based ball-point pen having a metal nib, it is preferable to use a phosphate surfactant. Phosphate ester-based surfactants are effective as lubricants in ink compositions because their phosphoric acid groups have the property of being easily adsorbed to metals. Therefore, when an ink composition containing a phosphate ester-based surfactant is applied to the water-based ballpoint pen, the phosphate ester-based surfactant adsorbs to the ball surface and the ball receiving seat of the ballpoint pen tip, resulting in the ball surface and the ball receiving seat. A lubricating layer consisting of a phosphate surfactant is formed on the surface of the seat to improve the lubricity between the ball and the ball receiving seat, which allows the ball to rotate smoothly, thereby reducing the wear of the ball receiving seat. can be suppressed, and writing feeling such as writing feeling can be improved.

〔式中、Ｘ_１、Ｘ_２、及びＸ_３は、下記式（１５）で示される基、又はヒドロキシ基であり、Ｘ_１、Ｘ_２、及びＸ_３の少なくとも１つは式（１５）で示される基である〕

（式中、Ｒ_１は炭化水素基、Ｒ_２はアルキレン基であり、ｎは１以上の整数である） Phosphate-based surfactants are compounds represented by the following formula (14).

[Wherein, X ₁ , X ₂ and X ₃ are a group represented by the following formula (15) or a hydroxy group, and at least one of X ₁ , X ₂ and X ₃ is represented by the formula (15) is a group shown]

(wherein R ₁ is a hydrocarbon group, R ₂ is an alkylene group, and n is an integer of 1 or more)

As the phosphate surfactant, the hydrocarbon group is preferably an alkyl group, an alkenyl group, or an aryl group, the hydrocarbon group is an alkyl group, an alkenyl group, or an aryl group, and the alkylene group is More preferably, it is an ethylene group.
The above-mentioned compound has an excellent effect on the formation of a lubricating layer on the surface of the ball and the surface of the ball receiving seat, so that the ball rotates more smoothly during writing, and the feeling of writing is further improved. can do.
The above phosphate surfactant may be an alkali metal salt or an amine salt.

Further, in formula (15), the hydrocarbon group is an aryl group phosphate surfactant, that is, the polyoxyalkylene aryl ether phosphate ester, there are also compounds in which the aryl group has a plurality of aromatic rings. included. A plurality of aromatic rings refers to a plurality of monocyclic aromatic rings or polycyclic aromatic rings having 2 or more rings, such as 2 to 4 benzene rings or naphthalene rings. In addition, the aryl group may include a monocyclic aromatic ring and a polycyclic aromatic ring having 2 or more rings in its structure.

Examples of the polyoxyalkylene aryl ether phosphate include polyoxyethylene monostyrylphenyl ether phosphate, polyoxyethylene distyrylphenyl ether phosphate, polyoxyethylene tristyrylphenyl ether phosphate, polyoxyethylene Examples include ethylene cumylphenyl ether phosphate, polyoxyethylene naphthyl ether phosphate, and the like.

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

Although the phosphate surfactant is not particularly limited, it preferably has an HLB value of 9-18, more preferably 10-18. A phosphate surfactant having an HLB value within the above range has high solubility in the ink composition according to the present invention, exhibits excellent stability over time in the ink composition, and adsorbs to the surface of the microcapsule pigment. Therefore, it is possible to suppress the aggregation of the microcapsule pigments. Furthermore, the phosphate surfactant having an HLB value of 9 to 18 adsorbs to the surface of the microcapsule pigment without being affected by temperature changes even when the temperature of the ink composition changes excessively. Aggregation of microcapsule pigments can be suppressed. This is because in the ink composition, an interaction acts between PVP having a mass average molecular weight of 3,000 to 2,000,000 and the phosphate ester surfactant, and the phosphate ester surfactant adsorbs to the surface. It is presumed that the dispersion stability of the microcapsule pigment obtained is further stabilized by PVP.
A ballpoint pen containing an ink composition containing a reversible thermochromic microcapsule pigment as a coloring agent (reversible thermochromic ballpoint pen) may lose its color when exposed to high temperatures in summer. The ink can be recolored by exposing it to a low temperature that freezes, but if the ink composition undergoes an excessive temperature change, the microcapsule pigment in the ink composition aggregates and the ink ejection property decreases. Sometimes. However, by blending a phosphate ester surfactant with an HLB value of 9 to 18 in the ink composition according to the present invention, even if the ink composition is subjected to excessive temperature changes, the above-mentioned PVP and phosphorus Due to the interaction with the acid ester-based surfactant, aggregation of the microcapsule pigments can be suppressed without being affected by temperature changes. As a result, the microcapsule pigment exhibits excellent dispersion stability, and even when the state of the ink changes from liquid to solid or vice versa as the ink composition freezes or thaws, the microcapsule pigment exhibits excellent dispersion stability. is inhibited from agglomeration and deterioration of ink fluidity. Therefore, it becomes easy to obtain an ink composition having excellent ink ejection properties from the pen tip.

When the ballpoint pen refill or ballpoint pen has a metal writing tip (pen tip), the pen tip may corrode if the ink composition contained in the ballpoint pen is acidic, but the HLB value is 9 to 18. An ink composition containing a phosphate ester-based surfactant can suppress the aggregation of microcapsule pigments even if it is not acidic. It can be used for ballpoint pen refills or ballpoint pens.
In other words, an ink composition containing a phosphate ester surfactant having an HLB value of 9 to 18 is suitably used for ballpoint pen refills or ballpoint pens equipped with metal ballpoint pen tips.

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 according to the Griffin method ranges from 0 to 20, and the larger the value, the more hydrophilic the compound.
HLB value = 20 x (mass% of hydrophilic group) = 20 x (sum of formula weight of hydrophilic group/molecular weight of surfactant) (16)

The ink composition according to the present invention can be blended with a pH adjuster, and various acids or bases can be used to adjust the pH of the ink composition to an appropriate range.
Examples of pH adjusters 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/triethanolamine, Water-soluble amine compounds such as diethanolamine, urea derivatives such as urea, dimethylurea, diethylurea, hydroxymethylurea, or hydroxyethylurea, or organic basic compounds such as amide compounds such as acetamide or N-methylacetamide / Examples include 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 of the pH adjuster is preferably 0.1 to 5% by mass, more preferably 0.5 to 2% by mass, relative to the total mass of the ink composition. is in the range.

The ink composition according to the present invention can be blended with a water-soluble organic solvent that is compatible with water, thereby improving the quick-drying property of the ink.
Examples of water-soluble organic solvents include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thioethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, and 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 and the like can be exemplified.
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 is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and further preferably 5 to 30% by mass, relative to the total mass of the ink composition. It is preferably in the range of 10 to 25% by mass. If the content of the water-soluble organic solvent exceeds 40% by mass, the viscosity of the ink tends to increase, and the ink ejection property of the ball-point pen containing the ink composition tends to deteriorate, which tends to impair the writing performance. On the other hand, if the blending ratio is less than 1% by mass, the effect of suppressing water evaporation is poor.

Resins such as acrylic resins, styrene-maleic acid copolymers, cellulose derivatives, and polyvinyl alcohol can be blended into the ink composition according to the present invention to impart adhesion and viscosity to paper surfaces. .

The ink composition according to the present invention can contain dextrin. Since dextrin has excellent film-forming properties, when the ink composition is applied to a ball-point pen, it can suppress volatilization of a medium such as water in the ink composition from the tip of the pen.
The dextrin is preferably a sugar mixture containing starch saccharification products of octa or more sugars and/or reduced products thereof. The sugar mixture preferably contains 30% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more of starch saccharified products having octahedral or higher sugars.
When the ink composition according to the present invention contains dextrin, the content of dextrin is preferably in the range of 0.1 to 5% by weight relative to the total weight of the ink composition. When the content of dextrin is within the above range, the ink jettability from the pen tip is maintained at a high level, and the ink drips and the medium such as water in the ink composition volatilizes from the pen tip. can be suppressed.

Various additives can also be added to the ink composition according to the present invention, if necessary.
Examples of additives include
Rust inhibitors such as benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, saponin, etc.
carbolic acid, sodium salt of 1,2-benzothiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl parahydroxybenzoate, 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine preservatives or antifungal agents such as
Ascorbic acids, erythorbic acids, α-tocopherol, catechins, synthetic polyphenols, kojic acid, alkyl hydroxylamines, oxime derivatives, α-glucosylrutin, α-lipoic acid, phosphonates, phosphinates, sulfites, sulfoxylates , dithionite, thiosulfate, thiourea dioxide and other foam absorbents,
Wetting agents such as reduced or non-reduced starch hydrolysates, disaccharides such as trehalose, oligosaccharides, sucrose, cyclodextrin, glucose, dextrin, sorbitol, mannitol, sodium pyrophosphate, and the like can be exemplified.
Furthermore, an antifoaming agent, a dispersant, a specific gravity adjuster, etc. may be blended.

The ink composition according to the present invention can be blended with a lubricant to easily prevent abrasion of the ball-point pen refill or the ball seat of the ball-point pen.
Examples of lubricants include higher fatty acids such as oleic acid, nonionic surfactants having long-chain alkyl groups, polyether-modified silicone oils, tri(alkoxycarbonylmethyl) thiophosphite and tri(alkoxycarbonyl) thiophosphite. thiophosphite triesters such as ethyl esters), phosphoric acid monoesters of polyoxyethylene alkyl ethers or polyoxyethylene alkylaryl ethers, phosphoric acid diesters of polyoxyethylene alkyl ethers or polyoxyethylene alkylaryl ethers, and metals thereof Salts, ammonium salts, amine salts, alkanolamine salts and the like can be exemplified.

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

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 is obtained by stirring the mixture containing the above components with various stirrers such as propeller stirring, homodisper, or homomixer, or by dispersing with various dispersers such as bead mills. can manufacture things.

The viscosity of the ink composition according to the present invention is preferable because it can suppress sedimentation or aggregation of the microcapsule pigment when measured at a rotation speed of 1 rpm (shear rate: 3.84 sec ⁻¹ ) in an environment of 20° C. is in the range of 1 to 2000 mPa·s, more preferably 3 to 1500 mPa·s, still more preferably 500 to 1000 mPa·s. In addition, when measured at a rotation speed of 100 rpm (shear rate: 384 sec ^-1 ) in an environment of 20 ° C., the ink ejection property from the pen tip of the ballpoint pen can be improved, so the viscosity is preferably It is in the range of 1 to 200 mPa·s, more preferably 10 to 100 mPa·s, still more preferably 20 to 50 mPa·s. When the viscosity is 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 was measured using a rheometer [manufactured by TA Instruments, product name: Discovery HR-2, cone plate (diameter 40 mm, angle 1°)], the ink was placed in an environment of 20°C, and the rotation speed was 1 rpm. (shear rate: 3.84 sec ^-1 ) or a value measured at a rotation speed of 100 rpm (shear rate: 384 sec ^-1 ).

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

The pH of the ink composition according to the invention is preferably in the range of 4-9, more preferably 4-8. When the pH is within the above range, aggregation or sedimentation of the microcapsule pigment contained in the ink in a low temperature range can be suppressed.
The pH is a value measured by placing the ink in an environment of 20° C. using a pH meter (product name: IM-40S, manufactured by Toa DKK Co., Ltd.).

Since the ink composition according to the present invention has shear thinning properties, it is particularly useful as a water-based ink composition for ballpoint pens, and is used by filling ballpoint pen refills or ballpoint pens with a ballpoint pen tip attached to the writing tip.

A ballpoint pen refill (hereinafter referred to as "refill") can be obtained by housing the ink composition according to the present invention in an ink container and directly connecting the ballpoint pen tip, or by connecting the ink container and the tip via a connecting member. ) can be formed.
Ballpoint pen tips include, for example, a tip in which a ball is held in a ball holding portion formed by pressing and deforming the tip of a metal pipe inward from the outer surface, and a ball formed by cutting a metal material with a drill or the like. A chip in which a ball is held in a holding part, a chip in which a resin ball receiving seat is provided inside a metal or plastic chip, or a ball held in the chip is urged forward by a spring. things, etc. can be exemplified.
It is preferable that the ball-point pen tip has a metal pipe having a straight cylindrical body (straight tubular body) at least at the tip. As the shape of such a ballpoint pen tip, for example, the entire ballpoint pen tip is made of a straight cylindrical metal pipe, or has a straight metal pipe at the tip and has an outer diameter and a One having a shape in which the inner diameter expands can be mentioned. Of these, the latter is preferred because of its good ink ejection properties. Further, by combining the ink composition according to the present invention with a ball-point pen having a ball diameter of, for example, 0.2 to 0.5 mm among the pipe-type ball-point pen tips having such a structure, the ink ejection property and dry-up resistance are improved. You can get a good ballpoint pen.

The material of the ball-point pen tip and ball is not particularly limited, and examples thereof include cemented carbide (hard), stainless steel, ruby, ceramics, resin, rubber, and the like. Furthermore, the ball can be subjected to surface treatment such as DLC coating.
The diameter of the ball is generally 0.2-3 mm, preferably 0.2-2 mm, more preferably 0.2-1.5 mm, still more preferably 0.2-1 mm, particularly preferably 0.2-0. 0.5 mm can be applied.
In general, a ball-point pen having a ball with a small diameter has a small amount of ink on the surface of the ball, so the surface of the ball tends to dry out, and poor writing such as faint lines and skipped lines are likely to occur. Since it has excellent dry-up performance, it suppresses drying at the tip of the writing and hardly causes poor writing. Used.

As the ink container, for example, a molding made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon, or a metal tubular body is used.
In order to prevent the contained ink composition from being denatured by oxygen, a molded article made of a resin having low oxygen permeability, such as ethylene-vinyl alcohol copolymer, vinylidene chloride resin, acrylonitrile resin, polyester resin, etc., is preferable. Used.
Further, the ink container may have a single-layer structure or a multi-layer structure. When the ink container has a multilayer structure, at least one layer is preferably made of ethylene-vinyl alcohol copolymer, vinylidene chloride resin, acrylonitrile resin, or polyester resin. Further, when the ink container is an ink container having a multi-layered structure of three or more layers and a combination of layers made of ethylene-vinyl alcohol copolymer, vinylidene chloride resin, acrylonitrile resin, and polyester resin, these layers are the outermost layer and the Arrangement other than the innermost layer is preferable.

The rear end of the ink contained in the ink containing body is filled with an ink backflow prevention member. Ink backflow preventers include liquid plugs or solid plugs.
The liquid plug consists of a non-volatile liquid and/or a sparingly volatile liquid, such as petroleum jelly, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefins, oligomers or co-oligomers of α-olefins, dimethyl Examples include silicone oil, methylphenyl silicone oil, amino-modified silicone oil, polyether-modified silicone oil, and fatty acid-modified silicone oil.
The nonvolatile liquid and/or the hardly volatile liquid can be used singly or in combination of two or more.

It is preferable to add a thickening agent to the non-volatile liquid and/or the low-volatility liquid to increase the viscosity to a suitable viscosity.
Examples of thickening agents include silica whose surface is hydrophobically treated, fine particle silica whose surface is methylated, aluminum silicate, swelling mica, clay-based thickeners such as bentonite and montmorillonite which are hydrophobically treated, and magnesium stearate. , fatty acid metal soaps such as calcium stearate, aluminum stearate, and zinc stearate; tribenzylidene sorbitol, fatty acid amides, amide-modified polyethylene waxes; hydrogenated castor oil; .

Examples of solid plugs include solid plugs made of polyethylene, polypropylene, and polymethylpentene.
As an ink backflow preventer, the liquid plug and the solid plug can be used in combination.

A resin coating may be adhered to the tip of the ballpoint pen to prevent the tip from drying out. By fixing the resin film so as to cover the ball at the tip end, the ball gripping portion, and the gap between the ball and the ball gripping portion, the tip tip is prevented from drying and the medium such as water in the ink composition is removed. Volatilization can be prevented.
As the resin for forming the resin film, for example, a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, or the like can be used.

A ball-point pen can be formed by housing the ball-point pen refill in the barrel.
The above ball-point pen is provided with a cap that covers the writing tip to make it a cap-type ball-point pen. can be prevented.
Further, by providing a retractable mechanism for retracting the writing tip from the ballpoint pen main body (barrel) to form a retractable ballpoint pen, it is possible to prevent the writing tip from being contaminated or damaged.

Any ballpoint pen with a retractable mechanism is used as long as it has a structure in which the tip of the writing tip is exposed to the outside air and is housed in the barrel, and the tip of the writing tip protrudes from the opening of the barrel by the operation of the retraction mechanism. be able to.
For example, (1) an operation portion (clip) that can move in the front-rear direction is projected radially outward from the rear side wall of the barrel, and the operation portion is slid forward to open the front end of the barrel. (2) A rear end knock that causes the writing tip to appear and retract from the front end opening of the barrel by pressing forward an operation part provided at the rear end of the barrel. (3) a side-knock type retracting mechanism for retracting the writing tip from the front end opening of the barrel by pressing an operating portion protruding from the outer surface of the side wall of the barrel radially inward; A rotating retractable mechanism or the like can be exemplified for retracting and retracting the writing tip from the front end opening of the barrel by rotating the operating portion at the rear portion of the cylinder.
The ink composition according to the present invention is excellent in dry-up resistance, and is less likely to cause poor writing such as fading and line skipping due to drying at the writing tip, and is therefore suitable for retractable ball-point pens.

A ballpoint pen can also be formed by directly filling a ballpoint pen having a ballpoint tip attached to the writing tip with the ink composition according to the present invention. In such a ballpoint pen, for example, the ink composition according to the present invention is filled in a ballpoint pen body (barrel) that communicates with a ballpoint pen tip having a ball attached to the tip, and the end surface of the ink is filled with ink as the ink is consumed. A ball-point pen or the like in which an ink backflow preventive body that follows is in close contact can be exemplified.

Ballpoint pen tips include, for example, a tip in which a ball is held in a ball holding portion formed by pressing and deforming the tip of a metal pipe inward from the outer surface, and a ball formed by cutting a metal material with a drill or the like. A chip in which a ball is held in a holding part, a chip in which a resin ball receiving seat is provided inside a metal or plastic chip, or a ball held in the chip is urged forward by a spring. things, etc. can be exemplified.

Materials for the ball-point pen tip and the ball are not particularly limited, and examples thereof include cemented carbide (hard), stainless steel, ruby, ceramics, resin, and rubber. Furthermore, the ball can be subjected to surface treatment such as DLC coating.
The diameter of the ball is generally 0.2-3 mm, preferably 0.2-2 mm, more preferably 0.2-1.5 mm, still more preferably 0.2-1 mm, particularly preferably 0.2-0. 0.5 mm can be applied.
In general, a ball-point pen having a ball with a small diameter has a small amount of ink on the surface of the ball, so the surface of the ball tends to dry out, and poor writing such as faint lines and skipped lines are likely to occur. Since it has excellent dry-up performance, it suppresses drying at the tip of the writing and makes it difficult to cause poor writing. Used.

As the shaft tube containing the ink composition, for example, a molded body made of thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, nylon, or the like is used.
Furthermore, by making the barrel light shielding, it is possible to suppress deterioration of the contained ink composition due to light.
A ball-point pen tip may be directly connected to the barrel, or the barrel and ball-point pen tip may be connected via a connecting member.

The trailing end of the ink contained in the barrel is filled with an ink backflow preventive. Ink backflow preventers include liquid plugs or solid plugs.
The liquid plug consists of a non-volatile liquid and/or a sparingly volatile liquid, such as petroleum jelly, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefins, oligomers or co-oligomers of α-olefins, dimethyl Examples include silicone oil, methylphenyl silicone oil, amino-modified silicone oil, polyether-modified silicone oil, and fatty acid-modified silicone oil.
The nonvolatile liquid and/or the hardly volatile liquid can be used singly or in combination of two or more.

It is preferable to add a thickening agent to the non-volatile liquid and/or the low-volatility liquid to increase the viscosity to a suitable viscosity.
Examples of thickening agents include silica whose surface is hydrophobically treated, fine particle silica whose surface is methylated, aluminum silicate, swelling mica, clay-based thickeners such as bentonite and montmorillonite, which are hydrophobically treated, and magnesium stearate. , fatty acid metal soaps such as calcium stearate, aluminum stearate, and zinc stearate; tribenzylidene sorbitol, fatty acid amides, amide-modified polyethylene waxes; hydrogenated castor oil; .

Examples of solid plugs include solid plugs made of polyethylene, polypropylene, and polymethylpentene.
As an ink backflow preventer, the liquid plug and the solid plug can be used in combination.

Furthermore, the form of the ball-point pen is not limited to the configuration described above. A composite ball-point pen (double-ended type, pen-tip feeding type, etc.) in which the color tone of the ink derived from each tip is different may be used.
In addition, it is possible to provide a composite type retractable ballpoint pen in which a plurality of ballpoint pen refills are accommodated in the barrel, and the writing tip of any one of the ballpoint pen refills is retracted from the opening of the barrel by the actuation of the retraction mechanism.

By writing on a surface to be written with a ball-point pen containing the ink composition according to the present invention, it is possible to form a handwriting, and the handwriting can be discolored by rubbing with a finger or by a heating tool or a cooling tool. .
Examples of the heating tool include an electric heating discoloring tool equipped with a resistance heating element such as a PTC element, a heating discoloring tool filled with a medium such as warm water, a heating discoloring tool using steam, laser light, etc., and a hair dryer. However, friction members and friction bodies are preferable because they can be discolored by a simple method.
Examples of the cooling device include an electrically-cold heat discoloring device using a Peltier element, a cold heat discoloring device filled with a refrigerant such as cold water or ice chips, a cooling agent, a refrigerator or a freezer, and the like.

As the friction member and the friction body, elastic bodies such as elastomers and plastic foams, which are highly elastic and can generate frictional heat by generating moderate friction when rubbed, are preferable. Metal, fabric, etc. can also be used.
A general eraser used for erasing handwriting with a pencil may be used to rub the handwriting. Friction bodies are preferably used.
Examples of materials for the friction member and friction body include silicone resin and SEBS resin (styrene-ethylene-butadiene-styrene block copolymer). The SEBS resin is more preferably used because the silicone resin tends to adhere to areas erased by rubbing, and the handwriting tends to be repelled when repeatedly written.

The above-mentioned friction member or friction body may be a member of any shape separate from the ball-point pen. A ball-point pen set can also be obtained by combining a ball-point pen with an arbitrary-shaped friction member or friction body that is separate from the ball-point pen.

When the ball-point pen according to the present invention is a cap-type ball-point pen, the place where the friction member or the friction body is provided is not particularly limited. When a clip is provided, the clip itself may be formed from a friction member, or a friction member or friction body may be provided at the tip of the cap (top) or the rear end of the barrel (the portion where the writing tip is not provided). can be done.
Further, in the case of the retractable ballpoint pen according to the present invention, the place where the friction member or the friction body is provided is not particularly limited. Alternatively, the clip itself may be formed of a friction member, or a friction member or friction body may be provided in the vicinity of the opening of the barrel, the rear end of the barrel (the portion where the writing tip is not provided), or the knock portion.

Examples are shown below, but the present invention is not limited thereto. In addition, unless otherwise specified, "parts" in the examples indicate "mass parts".

Preparation of reversible thermochromic microcapsule pigment A (A) 4.5 parts of 2-(2-chloroanilino)-6-di-n-butylaminofluorane as component and 1,1-bis( 4-Hydroxyphenyl)n-decane 4.5 parts, 2,2-bis(4-hydroxyphenyl)hexafluoropropane 7.5 parts, and (c) 4-benzyloxyphenylethyl caprate as component 50 parts A reversible thermochromic composition is 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% polyvinyl alcohol aqueous solution and heated. After continuing stirring while stirring, 2.5 parts of a water-soluble modified aliphatic amine was added, and stirring was continued to prepare a microcapsule dispersion. A reversible thermochromic microcapsule pigment A having an average particle size of 1.9 μm was obtained from the above microcapsule dispersion by centrifugation.
The reversible thermochromic microcapsule pigment A had a complete coloring temperature t ₁ of −20° C. and a complete decoloring temperature t ₄ of 59° C., and reversibly changed from black to colorless with temperature change.

Preparation of reversible thermochromic microcapsule pigment B A reversible thermochromic composition comprising 8 parts of 2,2-bis(4-hydroxyphenyl)hexafluoropropane as component () and 50 parts of 4-benzyloxyphenylethyl caprate as component (c) was used as a wall film material. After being put into a mixed solution consisting of 35 parts of an aromatic isocyanate prepolymer and 40 parts of a co-solvent, it was emulsified and dispersed in an 8% polyvinyl alcohol aqueous solution, and after continuing stirring while heating, water-soluble aliphatic modification 2.5 parts of amine was added and stirring was continued to prepare a microcapsule dispersion. A reversible thermochromic microcapsule pigment B having an average particle size of 2.3 μm was obtained from the above microcapsule dispersion by centrifugation.
The reversible thermochromic microcapsule pigment B has a complete coloring temperature t ₁ of −20° C. and a complete decoloring temperature t ₄ of 60° C., and reversibly changes from blue to colorless with temperature change.

Example 1
Preparation of aqueous ink composition Reversible thermochromic microcapsule pigment A (previously cooled to -20 ° C. or less to develop a black color) 18 parts, N-vinyl-2-pyrrolidone polymer (PVP) (mass average Molecular weight: 15,000) 2 parts, shear thinning agent (succinoglycan) [manufactured by Sansho Co., Ltd., product name: Leozan] 0.2 parts, and phosphate ester surfactant (polyoxyethylene Tristyryl phenyl ether phosphate) 0.5 parts, glycerin 5 parts, dextrin [manufactured by Sanwa Starch Kogyo Co., Ltd., product name: Sundec 30] 2 parts, 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.
In addition, the content of PVP with respect to the total mass of the ink composition (P _PVP ) is 2, the content of microcapsule pigment with respect to the total mass of the ink composition (P _MC ), and the content of PVP with respect to the total mass of the ink composition. The ratio (P _MC /P _PVP ) to the rate (P _PVP ) was 9.

Production of Ballpoint Pen After the ink container made of a polypropylene pipe was filled with the above ink composition by suction, a ballpoint pen tip having a cemented carbide ball with a diameter of 0.5 mm held at the tip was placed via a resin holder. connected. Next, a viscoelastic ink backflow preventer (liquid plug) containing polybutene as a main component is filled from the rear end of the ink reservoir, and the tail plug is fitted to the rear of the pipe, followed by centrifugal separation for degassing. and obtained a ballpoint pen refill.
Next, the above refill was incorporated into the barrel to produce a ball-point pen (retractable ball-point pen).
The above-mentioned ballpoint pen is housed in the barrel with the tip provided on the ballpoint pen refill exposed to the outside air, and is operated by a clip-shaped retracting mechanism (slide mechanism) provided on the rear side wall of the barrel. The tip protrudes from the front end opening of the barrel. SEBS resin is attached as a friction member to the rear end of the barrel.

Examples 2-11 and Comparative Examples 1-6
A water-based 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 shown in Table 1 below. Table 1 shows P _PVP and P _MC /P _PVP in each ink composition.
A ballpoint pen was produced in the same manner as in Example 1, except that the diameter of the ball used was changed to that shown in Table 1.

The contents of the materials in Table 1 are explained along with the note numbers.
(1) Black reversible thermochromic microcapsule pigment (2) Blue reversible thermochromic microcapsule pigment (3) Weight 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 Sansho Co., Ltd., product name: Leozan]
(8) Xanthan gum [manufactured by Sansho Co., Ltd., product name: Kelzan]
(9) Polyoxyethylene tristyrylphenyl ether phosphate (HLB value: 16)
(10) Polyoxyethylene tridecyl ether phosphate (HLB value: 12)
(11) Polyoxyethylene distyrylphenyl ether phosphoric acid monoester, diester, and triester mixture (HLB value: 5)
(12) Dextrin [manufactured by Sanwa Starch Industry Co., Ltd., product name: Sundec 30]
(13) Triethanolamine (14) Antifungal agent [manufactured by Lonza Japan Co., Ltd., product name: Proxel XL-2 (S)]

[pH measurement]
The ink compositions obtained in Examples 1 to 11 and Comparative Examples 1 to 6 were measured in a room temperature (20°C) environment using a pH meter [manufactured by Toa DKK Co., Ltd., product name: IM-40S]. pH was measured below. The results obtained are listed in Table 2 below.

[Viscosity measurement]
For each ink composition obtained in Examples 1 to 11 and Comparative Examples 1 to 6, a rheometer [manufactured by TA Instruments, product name: Discovery HR-2, cone plate (diameter 40 mm, angle 1°)] was used to measure the viscosity at room temperature (20° C.) at a rotation speed of 1 rpm (shear rate: 3.84 sec ⁻¹ ) and a rotation speed of 100 rpm (shear rate: 384 sec ⁻¹ ). The results obtained are listed in Table 2 below.

Evaluation of initial writing performance Using the ballpoint pens of Examples 1 to 11 and Comparative Examples 1 to 6, under a room temperature (20 ° C.) environment, an A4 size test paper (portrait) in the short direction and parallel direction. In addition, 12 elliptical circles (about 15 mm long and 8 mm short) per line were handwritten in a spiral so that the circles were in contact with each other, and 3 lines were continuously written. Writing paper A conforming to old JIS P3201 was used as the test paper.
The resulting handwriting was visually confirmed and evaluated according to the following criteria. The evaluation results are shown in Table 3 below.
A: A good handwriting was obtained without blurring, line skipping, etc. in the handwriting.
B: Slight fading and line skipping were observed in the handwriting, but the level was practically non-problematic.
C: A large number of faint lines and line skipping were observed in the handwriting.
D: It was impossible to write.

Evaluation of Writing Performance After Time Each of the ballpoint pens subjected to the writing test was allowed to stand sideways for 60 days in a constant temperature bath set at 50°C. After 60 days, it was removed from the constant temperature bath and placed in a room temperature (20 ° C.) environment in parallel with the short direction of an A4 size test paper (portrait), 12 elliptical circles (long diameter 15 mm, Approximately 8 mm in short diameter) was handwritten in a spiral so that the circles were in contact with each other, and three lines were continuously written. Writing paper A conforming to old JIS P3201 was used as the test paper.
The resulting handwriting was visually confirmed and evaluated according to the following criteria. The evaluation results are shown in Table 3 below.
A: A good handwriting was obtained without blurring, line skipping, etc. in the handwriting.
B: Slight fading and line skipping were observed in the handwriting, but the level was practically non-problematic.
C: A large number of faint lines and line skipping were observed in the handwriting.
D: It was impossible to write.

Evaluation of Ink Stability Each of the ballpoint pens of Examples 1 to 11 and Comparative Examples 1 to 6 was allowed to stand sideways in a constant temperature bath set at 60° C. for 14 days. After 14 days had passed, it was taken out from the constant temperature bath, and then left standing sideways in a constant temperature bath set at -20°C for 1 day. After one day had passed, the ballpoint pen was taken out from the constant temperature bath, and the state of the ink contained in the refill in the ballpoint pen was visually confirmed and evaluated according to the following criteria. The evaluation results are shown in Table 3 below.
A: No sedimentation of the pigment was observed in the ink in the refill, and the appearance was the same as the initial stage.
B: The ink in the refill showed slight separation due to agglomeration and sedimentation of the pigment, but the handwriting with the ballpoint pen was at a practically non-problematic level.
C: Separation due to aggregation and sedimentation of the pigment was observed in the ink in the refill, and a large number of faint lines and missing lines were observed in the handwriting with the ballpoint pen, or writing was impossible.

t ₁ complete color development temperature t ₂ color development start temperature t ₃ color development start temperature t ₄ complete color development temperature T ₁ complete color development temperature T ₂ color development start temperature T ₃ color development start temperature T ₄ complete color development temperature ΔH hysteresis width

Claims (10)

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 reaction of the components (a) and (b). a reversible thermochromic microcapsule pigment encapsulating a substance;
an N-vinyl-2-pyrrolidone polymer having a mass average molecular weight of 3,000 to 2,000,000;
a shear thinning agent;
water and,
An aqueous ink composition for a reversible thermochromic ballpoint pen, comprising at least: The reversible thermochromic color change according to claim 1, wherein P _PVP is the content of the N-vinyl-2-pyrrolidone polymer with respect to the total mass of the ink composition, and the P _PVP is 0.1 to 10% by mass. A water-based ink composition for a flexible ball-point pen. When _PMC is the content of the reversible thermochromic microcapsule pigment with respect to the total mass of the ink composition, regarding the P _PVP and P _MC ,
3≦P _MC /P _PVP ≦60
The water-based ink composition for a reversible thermochromic ball-point pen according to claim 1 or 2, which satisfies the following: 4. The water-based ink composition for a reversible thermochromic ball-point pen according to any one of claims 1 to 3, wherein the shear thinning agent is succinoglycan. 5. The water-based ink composition for a reversible thermochromic ballpoint pen according to any one of claims 1 to 4, further comprising a phosphate surfactant having an HLB value of 9 to 18. A refill containing the aqueous ink composition for a reversible thermochromic ballpoint pen according to any one of claims 1 to 5. 7. The refill according to claim 6, wherein the ball provided at the writing tip of said refill has a diameter of 0.2 to 0.4 mm. A water-based ball-point pen containing the refill according to claim 6 or 7 in a barrel. 9. The water-based ball-point pen according to claim 8, further comprising a retractable mechanism. 10. The water-based ball-point pen according to claim 8 or 9, comprising a friction member for discoloring the handwriting of said water-based ball-point pen by frictional heat.

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