JP7383573B2 - Thermochromic water-based ink composition for writing instruments, and writing instruments using the same - Google Patents

Description

The present invention relates to an aqueous ink composition for writing instruments containing a thermochromic microcapsule pigment and a writing instrument containing the same.

BACKGROUND ART Water-based ink compositions containing microcapsule pigments encapsulating thermochromic compositions (thermochromic microcapsule pigments) have been known and have been used in inks for various writing instruments. (For example, see Patent Document 1)

Patent Document 1 describes a thermochromic aqueous ink for ballpoint pens containing a thermochromic microcapsule pigment and a shear-thinning substance (shear-thinning agent). This ink is an ink that can change the color of the handwriting due to the heat generated by friction with friction materials, hot air from a hair dryer, cold air from a refrigerator/freezer, etc., and when the ink is left still due to the shear thinning agent. The dispersion stability of the microcapsule pigment is said to be good, and when the ink is subjected to strong shearing force from the ball during writing, the ink becomes low in viscosity and is easily ejected from the nib, resulting in excellent writing feel and handwriting formation. Therefore, the ink has both the dispersion stability of the microcapsule pigment and the writing performance.
Further, the above-mentioned document exemplifies an ink using a heat-decolorable (heat-decolorable) microcapsule pigment that changes color tautochromatically from colored to colorless and from colorless to colored depending on the temperature.

However, in the conventional ink, although the dispersion stability of the microcapsule pigment recovers along with the ink viscosity after being ejected onto the paper surface, some of the microcapsule pigment penetrates into the paper before the ink viscosity recovers. It was difficult to make clear handwriting because it did not stay on the paper surface.
Furthermore, when handwriting formed with the ink of the prior art is discolored by rubbing with a friction member, it may be difficult to generate enough heat to completely discolor the handwriting by rubbing, and the handwriting may change color. sometimes became unclear. In particular, it has not been easy to change the color of such pigments because heat is less easily transmitted to the microcapsule pigments that have entered the interior of the paper compared to the microcapsule pigments that have adhered to the paper surface.
For example, if the thermochromic microcapsule pigment has heat decoloring properties, it is possible to decolor the microcapsule pigment that adheres to the paper surface by rubbing, but it is difficult to decolor the microcapsule pigment that has penetrated inside the paper. There were cases where the handwriting was left with some color.

Japanese Patent Application Publication No. 09-124993

The present invention has been made in view of the above-mentioned drawbacks of the prior art. Specifically, the present invention is a water-based ink that uses a thermochromic microcapsule pigment as a colorant, and forms clear handwriting with excellent thermochromic properties on paper. The present invention provides a thermochromic aqueous ink composition for writing instruments, and a writing instrument containing the same.

The present invention
"1. An ink composition containing a thermochromic microcapsule pigment having a wall film made of a polymer and containing a thermochromic composition, a polyurethane emulsion, and water, wherein the polymer has a urea bond or A polyurethane film having at least one of the urethane bonds in the repeating unit and formed from only the polyurethane emulsion has a Young's modulus of less than 900 MPa as measured in accordance with JIS K 7161-1:2014/ISO527-1:2012. A thermochromic aqueous ink composition for writing instruments, characterized by:
2. The thermochromic composition comprises (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color-forming reaction of both of the above occurs. 2. The aqueous ink composition according to item 1, which is a reversible thermochromic composition.
3. A writing instrument containing the aqueous ink composition according to item 1 or 2. ”.

According to the present invention, there is provided a water-based ink composition for a thermochromic writing instrument, which is a water-based ink using a thermochromic microcapsule pigment as a coloring material, and which can form clear handwriting with excellent thermochromic properties on a paper surface, and Contained writing utensils will be provided.

FIG. 2 is an explanatory diagram showing the discoloration behavior of a microcapsule pigment (heat-decolorable type) encapsulating a reversible thermochromic composition. FIG. 2 is an explanatory diagram showing the color change behavior of a microcapsule pigment (heat-decolorable type) encapsulating a reversible thermochromic composition having color memory.

Embodiments of the present invention will be described in detail below. In the present specification, "parts", "%", "ratio", etc. indicating formulations are based on mass unless otherwise specified.

The aqueous ink composition for ballpoint pens according to the present invention (hereinafter sometimes referred to as "aqueous ink composition", "ink composition", or "composition") is composed of a thermochromic microcapsule pigment and a polyurethane emulsion. and water. Each component constituting the ink composition according to the present invention will be explained below.

(Thermochromic microcapsule pigment)
A thermochromic microcapsule pigment encapsulates a thermochromic composition. The thermochromic composition is a reversible thermochromic composition comprising (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the coloring reaction of both of the above occurs. are preferably used.

As the thermochromic microcapsule pigment, those described in Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, Japanese Patent Publication No. 1-29398, etc. can be used. These microcapsule pigments change color before and after a predetermined temperature (color change point), exhibit a colorless state at a temperature above the high temperature side discoloration point, and a colored state at a temperature range below the low temperature side discoloration point. It is. Of the two states, only one specific state exists in the normal temperature range, and the other state is maintained as long as the heat or cold required for that state to occur is applied. It has the characteristic that it returns to the state it exhibits at room temperature when heat or cold is no longer applied. Here, the compositions contained in these microcapsule pigments are heat-erasing type (hereinafter referred to as hysteresis width ΔH) having a relatively small characteristic (ΔH = 1 to 7°C) that indicates the degree of hysteresis (hysteresis width ΔH). It is a reversible thermochromic composition (decolorizes when heated and develops color when cooled) (see Figure 1).

Furthermore, thermochromic microcapsule pigments described in Japanese Patent Publication No. 4-17154, Japanese Patent Application Publication No. 7-179777, Japanese Patent Application Publication No. 7-33997, Japanese Patent Application Publication No. 8-39936, etc. can also be used. . These microcapsule pigments exhibit relatively large hysteresis characteristics (ΔH=8 to 50° C.). In other words, the shape of the curve plotting the change in coloring density due to temperature change is significantly different when the temperature is raised from a lower side than the discoloration temperature range and when it is lowered from a higher temperature side than the discoloration temperature range. It changes color as it follows the path (see Figure 2).

The hysteresis characteristic in the color density-temperature curve of the reversible thermochromic composition will be described in detail below with reference to the drawings.

In FIG. 2, the vertical axis represents color density, and the horizontal axis represents temperature. Changes in color density due to temperature changes progress along the arrows. Here, A is a point indicating the density at a temperature t ₄ (hereinafter referred to as complete decolorization temperature) at which a completely decolorized state is reached, and B is a point indicating the density at a temperature t ₃ (hereinafter referred to as decolorization start temperature) at which decolorization starts. C is a point indicating the density at a temperature t ₂ (hereinafter referred to as the color development start temperature) at which color development starts, and D is a point indicating the density at the temperature t ₁ (hereinafter referred to as complete color development temperature) at which a complete color development state is reached. This point indicates the density at the color development temperature.

The color change temperature range is the temperature range between t ₁ and t ₄ , which can exhibit either a colored state or a discolored state, and between t ₂ and t ₃ , which is a region with a large difference in color density. The temperature range is essentially a two-phase retention temperature range.

In addition, the length of the line segment EF is a measure of the contrast of discoloration, and the length of the line segment HG passing through the midpoint of the line segment EF is the hysteresis width ΔH, and if this ΔH value is small, both the states before and after the discoloration Only one specific state can exist in the normal temperature range. Moreover, when the ΔH value is large, it becomes easy to maintain each state before and after discoloration.

Specifically, as a reversible thermochromic composition having color memory, the complete color development temperature _t1 is a temperature that can only be obtained in a freezing room, a cold region, etc., that is, -50 to 0°C, preferably -40 to -5°C. °C, more preferably -30 to -10 °C, and the complete discoloration temperature _t4 is the frictional heat generated by a friction body, the temperature obtained from a familiar heating body such as a hair dryer, that is, 45 to 95 °C, preferably 50 to 90 °C. ℃, more preferably in the range of 60 to 80 degrees Celsius, and by specifying the ΔH value to 40 to 100 degrees Celsius, it can effectively function to maintain the color exhibited under normal conditions (in the everyday living temperature range).

Specific examples of compounds for each component (a), (b), and (c) are shown below.

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

Examples of the electron-donating color-forming organic compound include phthalide compounds, fluoran compounds, styrinoquinoline compounds, diazalhodamine lactone compounds, pyridine compounds, quinazoline compounds, bisquinazoline compounds, etc. Among these, phthalide compounds and fluoran compounds are preferred. .

Examples of phthalide compounds include diphenylmethane phthalide compounds, phenylindolylphthalide compounds, indolylphthalide compounds, diphenylmethane azaphthalide compounds, phenylindolyl azaphthalide compounds, and derivatives thereof. , phenylindolyl azaphthalide compounds, and derivatives thereof are preferred.
Furthermore, examples of the fluoran compound include aminofluoran compounds, alkoxyfluoran compounds, and derivatives thereof.

Examples of compounds that can be used as component (a) are listed below.
3,3-bis(p-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-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-propylindol-3-yl)-4-azaphthalide,
3,6-bis(diphenylamino)fluorane,
3,6-dimethoxyfluorane,
3,6-di-n-butoxyfluorane,
2-methyl-6-(N-ethyl-Np-tolylamino)fluoran,
3-chloro-6-cyclohexylaminofluorane,
2-methyl-6-cyclohexylaminofluorane,
2-(2-chloroamino)-6-dibutylaminofluorane,
2-(2-chloroanilino)-6-di-n-butylaminofluorane,
2-(3-trifluoromethylanilino)-6-diethylaminofluorane,
2-(3-trifluoromethylanilino)-6-dipentylaminofluorane,
2-(dibenzylamino)-6-diethylaminofluorane,
2-(N-methylanilino)-6-(N-ethyl-Np-tolylamino)fluoran,
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)fluoran,
1,2-benz-6-diethylaminofluorane,
1,2-benz-6-(N-ethyl-N-isobutylamino)fluoran,
1,2-benz-6-(N-ethyl-N-isoamylamino)fluoran,
2-(3-methoxy-4-dodecoxystyryl)quinoline,
Spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1'(3'H)isobenzofuran]-3'-one, 2-(diethylamino)-8-(diethylamino)-4-methyl ,
Spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(di- -n-butylamino)-4-methyl,
spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(diethylamino )-4-methyl,
spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(N -ethyl-N-i-amylamino)-4-methyl,
Spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1'(3'H)isobenzofuran]-3'-one, 2-(dibutylamino)-8-(dipentylamino)-4 - methyl,
4,5,6,7-tetrachloro-3-[4-(dimethylamino)-2-methoxyphenyl]-3-(1-butyl-2-methyl-1H-indol-3-yl)-1(3H )-isobenzofuranone,
4,5,6,7-tetrachloro-3-[4-(diethylamino)-2-ethoxyphenyl]-3-(1-ethyl-2-methyl-1H-indol-3-yl)-1(3H) -isobenzofuranone,
4,5,6,7-tetrachloro-3-[4-(diethylamino)-2-ethoxyphenyl]-3-(1-pentyl-2-methyl-1H-indol-3-yl)-1(3H) -isobenzofuranone,
4,5,6,7-tetrachloro-3-[4-(diethylamino)-2-methylphenyl]-3-(1-ethyl-2-methyl-1H-indol-3-yl)-1(3H) -isobenzofuranone,
3',6'-bis[phenyl(2-methylphenyl)amino]-spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one,
3',6'-bis[phenyl(3-methylphenyl)amino]-spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one,
3',6'-bis[phenyl(3-ethylphenyl)amino]-spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one,
2,6-bis(2'-ethyloxyphenyl)-4-(4'-dimethylaminophenyl)pyridine,
2,6-bis(2',4'-diethyloxyphenyl)-4-(4'-dimethylaminophenyl)pyridine,
2-(4'-dimethylaminophenyl)-4-methoxy-quinazoline,
4,4'-(ethylenedioxy)-bis[2-(4-diethylaminophenyl)quinazoline]

In addition to compounds having a substituent on the phenyl group forming the xanthene ring, fluoranes include compounds having a substituent on the phenyl group forming the xanthene ring and also substituents on the phenyl group forming the lactone ring (for example, It may be a compound that exhibits blue or black color and has an alkyl group such as a methyl group or a halogen atom such as a chloro group.

The component (b), ie, the electron-accepting compound, is a compound that receives electrons from the component (a) and functions as a color developer for the component (a).

The electron-accepting compounds include a group of compounds having an active proton, a group of pseudoacidic compounds (a group of compounds that are not acids but act as an acid in the composition and cause component (a) to develop color), and a group of compounds having an electron hole. There are compounds selected from the group of compounds, etc., and among these, compounds selected from the group of compounds having active protons are preferred.

Examples of the group of compounds having active protons include compounds having a phenolic hydroxyl group and their derivatives, carboxylic acids and their derivatives, preferably aromatic carboxylic acids and their derivatives, and aliphatic carboxylic acids having 2 to 5 carbon atoms and their derivatives. derivatives, 2-hydroxycarboxylic acid derivatives, N-substituted amino acid derivatives, acidic phosphate esters and their derivatives, azole compounds and their derivatives, 1,2,3-triazole and their derivatives, cyclic carbosulfimides, carbon Examples include several halohydrins, sulfonic acids and their derivatives, and inorganic acids.

Examples of the pseudoacidic compound group include metal salts of the compounds having a phenolic hydroxyl group, metal salts of the carboxylic acids, metal salts of the acidic phosphoric esters, metal salts of the sulfonic acids, aromatic carboxylic acid anhydrides, Aliphatic carboxylic acid anhydrides, mixed acid anhydrides of aromatic carboxylic acids and sulfonic acids, cycloolefin dicarboxylic acid anhydrides, urea and its derivatives, thiourea and its derivatives, guanidine and its derivatives, halogenated alcohols, etc. can be mentioned.

Examples of the group of compounds having electron holes include borates, borate esters, and inorganic salts.

Among these, compounds having a phenolic hydroxyl group are preferred because they can exhibit effective thermochromic properties.

The compounds having a phenolic hydroxyl group include a wide range from monophenol compounds to polyphenol compounds, and further include bis-type, tris-type phenols, etc., and phenol-aldehyde condensation resins. Among the compounds having a phenolic hydroxyl group, those having at least two or more benzene rings are preferred. Further, these compounds may have a substituent, and examples of the substituent include an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carboxyl group, an ester or amide group thereof, and a halogen group.

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

As a compound having one phenolic hydroxyl group,
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)decane-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,
4,4'-dihydroxybenzophenone,
4-chloro-4'-hydroxybenzophenone,
4-fluoro-4'-hydroxybenzophenone,
4-cyclohexylphenol,
2-hydroxybenzyl alcohol,
3-hydroxybenzyl alcohol,
4-hydroxybenzyl alcohol,
4-(2-hydroxyethyl)phenol,
3-methoxyphenol,
4-ethoxyphenol,
4-n-propoxyphenol,
4-n-butoxyphenol,
4-n-heptyloxyphenol,
4-(2-methoxyethyl)phenol,
α-naphthol,
β-naphthol,
2,3-dimethylphenol,
2,4-dimethylphenol,
2,6-dimethylphenol,
2,6-di-tert-butylphenol,
2,4-dichlorophenol,
2,4-difluorophenol, thymol,
3-methyl-4-methylthiophenol,
2-tert-butyl-5-methylphenol,
2,6-bis(hydroxymethyl)-4-methylphenol,
2,3,5-trimethylphenol,
2,6-bis(hydroxymethyl)-4-tert-octylphenol,
6-hydroxy-1,3-benzoxathiol-2-one,
2,4-bis(phenylsulfonyl)phenol,
2,4-bis(phenylsulfonyl)-5-methylphenol,
2,4-bis(4-methylphenylsulfonyl)phenol,
2-phenylphenol,
4-phenylphenol,
2,6-diphenylphenol,
3-benzylbiphenyl-2-ol,
3,5-dibenzylbiphenyl-4-ol,
4-cyano-4'-hydroxybiphenyl,
1-hydroxybenzotriazole,
1-hydroxy-5-methylbenzotriazole,
1-hydroxy-5-chlorobenzotriazole,
1-hydroxy-5-methoxybenzotriazole,
1-hydroxy-4-benzoylaminobenzotriazole,
1-hydroxy-4,5,6,7-tetrachlorobenzotriazole,
1,4-hydroxybenzotriazole,
1-hydroxy-5-nitrobenzotriazole,
1-hydroxy-5-phenylbenzotriazole,
1-hydroxy-5-benzylbenzotriazole,
1-hydroxy-5-ethylbenzotriazole,
1-hydroxy-5-n-octylbenzotriazole,
1-hydroxy-5-n-butylbenzotriazole,
n-butyl 4-hydroxybenzoate,
n-octyl 4-hydroxybenzoate,
4-hydroxybenzoic acid 2-heptadecafluorooctylethane,
benzyl 4-hydroxybenzoate,
4-hydroxybenzoic acid benzyl ester,
o-methylbenzyl 4-hydroxybenzoate,
m-methylbenzyl 4-hydroxybenzoate,
p-methylbenzyl 4-hydroxybenzoate,
p-ethylbenzyl 4-hydroxybenzoate,
p-propylbenzyl 4-hydroxybenzoate,
p-tert-butylbenzyl 4-hydroxybenzoate,
phenylethyl 4-hydroxybenzoate,
o-methylphenylethyl 4-hydroxybenzoate,
m-methylphenylethyl 4-hydroxybenzoate,
p-methylphenylethyl 4-hydroxybenzoate,
p-ethylphenylethyl 4-hydroxybenzoate,
p-propylphenylethyl 4-hydroxybenzoate,
Examples include p-tert-butylphenylethyl 4-hydroxybenzoate.

Compounds with two phenolic hydroxyl groups include resorcinol,
2-methylresorcin,
4-n-hexylresorcin,
4-n-octylresorcin,
4-tert-octylresorcin,
4-benzoylresorcin,
4-nitroresorcin,
Methyl β-resorucinate,
benzyl β-resorcate,
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-phenylacetyl resorcin,
4-phenylacetyl-6-chlororesorcin,
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,
methylhydroquinone,
trimethylhydroquinone, catechol,
4-tert-butylcatechol,
1,6-dihydroxynaphthalene,
2,7-dihydroxynaphthalene,
1,5-dihydroxynaphthalene,
2,6-dihydroxynaphthalene,
2,4-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 bis-type phenol compound,
1,1-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)propane,
1,1-bis(4-hydroxyphenyl)n-butane,
1,1-bis(4-hydroxyphenyl)n-pentane,
1,1-bis(4-hydroxyphenyl)n-hexane,
1,1-bis(4-hydroxyphenyl)n-heptane,
1,1-bis(4-hydroxyphenyl)n-octane,
1,1-bis(4-hydroxyphenyl)n-nonane,
1,1-bis(4-hydroxyphenyl)n-decane,
1,1-bis(4-hydroxy-3-methylphenyl)decane,
1,1-bis(4-hydroxyphenyl)n-dodecane,
1,1-bis(4-hydroxyphenyl)-2-methylpropane,
1,1-bis(4-hydroxyphenyl)-3-methylbutane,
1,1-bis(4-hydroxyphenyl)-3-methylpentane,
1,1-bis(4-hydroxyphenyl)-2,3-dimethylpentane,
1,1-bis(4-hydroxyphenyl)-2-ethylbutane,
1,1-bis(4-hydroxyphenyl)-2-ethylhexane,
1,1-bis(4-hydroxyphenyl)-3,7-dimethyloctane,
1,1-bis(4-hydroxyphenyl)cyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxy-3-methyl)cyclohexane,
diphenolic acid,
1-phenyl-1,1-bis(4-hydroxyphenyl)methane,
2,2-bis(4-hydroxyphenyl)propane,
2,2-bis(4-hydroxyphenyl)n-butane,
2,2-bis(4-hydroxyphenyl)n-pentane,
2,2-bis(4-hydroxyphenyl)n-hexane,
2,2-bis(4-hydroxyphenyl)n-heptane,
2,2-bis(4-hydroxyphenyl)n-octane,
2,2-bis(4-hydroxyphenyl)n-nonane,
2,2-bis(4-hydroxyphenyl)n-decane,
2,2-bis(4-hydroxyphenyl)n-dodecane,
2,2-bis(4-hydroxyphenyl)-6,10,14-trimethylpentadecane,
1-phenyl-1,1-bis(4-hydroxyphenyl)ethane,
2,2-bis(4-hydroxyphenyl)methylpropionate,
2,2-bis(4-hydroxyphenyl)butylpropionate,
2,2-bis(4-hydroxy-3-methylphenyl)methylpropionate,
2,2-bis(4-hydroxyphenyl)ethylpropionate,
2,2-bis(4-hydroxyphenyl)-4-methylpentane,
2,2-bis(4-hydroxyphenyl)-4-methylhexane,
2,2-bis(4-hydroxyphenyl)hexafluoropropane,
2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)hexafluoropropane,
2,2-bis(4-hydroxy-3-methylphenyl)propane,
2,2-bis(4-hydroxy-3-methylphenyl)butane,
2,2-bis(4-hydroxy-3-isopropylphenyl)propane,
2,2-bis(3-sec-butylphenyl-4-hydroxy)propane,
2,2-bis(4-hydroxy-3-phenylphenyl)propane,
2,2-bis(3-tert-butyl-4-hydroxyphenyl)propane,
2,2-bis(3-fluoro-4-hydroxyphenyl)propane,
2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)propane,
9,9-bis(4-hydroxy-3-methylphenyl)fluorene,
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
3,3-bis(4-hydroxyphenyl)oxindole,
3,3-bis(4-hydroxy-3-methylphenyl)oxindole,
bis(2-hydroxyphenyl)methane,
bis(2-hydroxy-5-methylphenyl)methane,
bis(2-hydroxy-3-hydroxymethyl-5-methyl)methane,
4,4'-[1,4-phenylenebis(1-methylethylidene)]bis(2-methylphenol),
1,1-bis(4-hydroxy-3-phenylphenyl)cyclohexane,
3,3-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-hydroxydiphenylsulfone,
4-methyl-4'-hydroxycyphenylsulfone,
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'-trihydroxydiphenylsulfone,
bis(3,4-dihydroxyphenyl)sulfone,
2,3,4-trihydroxydiphenylsulfone,
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 the compound having three phenolic hydroxyl groups include pyrogallol, phloroglucinol, phloroglucinol carboxylic acid, gallic fatty acid, octyl gallate, dodecyl gallate, and the like.

Furthermore, as tris-type phenol compounds,
4,4′,4″-methylizinetrisphenol,
4,4′,4″-methylidine tris(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″-ethyridine trisphenol,
4,4′,4″-ethyridine 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-hydroxycyphenyl)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″-methylizinetrisphenol,
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'-[(4-3-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″-methylidine tris(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.

As compounds having four or more phenolic hydroxyl groups,
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,
1,1,2,2-tetrakis(4-hydroxy-3-methylphenyl)ethane,
1,1,2,2-tetrakis(3,5-dimethyl-4-hydroxyphenyl)ethane,
1,1,4,4-tetrakis(3,5-dimethyl-4-hydroxyphenyl)benzene,
2,2'-bis[4,4-(4-hydroxy-3-methylphenyl)cyclohexyl]propane,
2,2'-[(3,4-dihydroxyphenyl)methylene]bis(3,5-dimethylphenol),
3,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl)catechol,
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[3-(2-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(3-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxybenzyl)-3-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane,
bis[3-(3-hydroxy-2-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(4-hydroxy-3-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(3-hydroxy-4-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxy-3-methylbenzyl)-2-hydroxy-5-methylphenyl]methane,
α,α′,α″,α′″-tetrakis(4-hydroxyphenyl)benzene, bis[3-(3,6-dimethyl-2-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
[3-(3,6-dimethyl-2-hydroxybenzyl)-2-hydroxy-5-methylphenyl] [3-(2,5-dimethyl-4-hydroxybenzyl)-2-hydroxy-5-methylphenyl] methane,
bis[3-(2,5-dimethyl-4-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(3,5-dimethyl-4-hydroxybenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[3-(2-hydroxy-3,4,6-trimethylbenzyl)-2-hydroxy-5-methylphenyl]methane,
bis[2-hydroxy-3-(4-hydroxy-2,3,5-trimethylbenzyl)-5-methylphenyl]methane,
4,4',4'',4'''-tetrakis(4-hydroxyphenyl)-1,1'-bicyclohexyl,
2,2'-bis[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane,
4,4',4'',4'''-tetrakis(4-hydroxy-3-methylphenyl)-1,1'-bicyclohexyl,
bis[3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)-4-hydroxy-5-methylphenyl]methane,
4,4',4'',4'''-tetrakis(3,5-dimethyl-4-hydroxyphenyl)-1,1'-bicyclohexyl,
1,1-bis[3-(2-hydroxy-5-methylbenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,1-bis[3-(3,5-dimethyl-4-hydroxybenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,1-bis[3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
4,6-bis[α-methyl-(4-hydroxyphenyl)benzyl-1,3-benzenediol,
2,2-bis[3-(4-hydroxy-3-methylbenzyl)-4-hydroxy-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(4-hydroxy-3-isopropylphenyl)-1,1'-bicyclohexyl,
4,4'-bis[(3,4-dihydroxyphenyl)methylene]bis(2-isopropylphenol)
2,4,6-tris(4-hydroxybenzyl)-1,3-benzenediol,
4,6-bis(3,5-dimethyl-4-hydroxybenzyl)pyrogallol,
3,3'-[(2-hydroxyphenyl)methylene]bis(5-methylcatechol),
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)resorcin,
2,4,6-tris(3,5-dimethyl-2-hydroxybenzyl)resorcin,
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)pyrogallol,
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″-ethylidine tris {[2-(2-hydroxy-5-methyl)benzyl]-6-methylphenol},
2,2-bis[3,5-bis(2-hydroxy-5-methylphenylmethyl)phenyl]propane, bis[3-(α,α-bis(2,5-dimethyl-4-hydroxyphenyl)methyl)-4 -Hydroxyphenyl]methane,
bis[5-(3,5-dimethyl-4-hydroxybenzyl)-2,3,4-trihydroxyphenyl]methane,
bis[3-(2,3,4-trihydroxybenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane,
1,1-bis[3-(2,3,4-trihydroxybenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,8,15,22-tetranonyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane,
4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(4-hydroxy-2-methylbenzyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(2-hydroxy-5-methylbenzyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(3-ethyl-4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(3-ethyl-4-hydroxybenzyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(3,5-dimethyl-2-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[ 2,6-bis(3,5-dimethyl-2-hydroxyphenyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-3-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(4-hydroxy-3-isopropylphenyl)phenol],
bis[3-(α,α-bis(3,5-dimethyl-4-hydroxyphenyl)methyl-4-hydroxyphenyl]methane,
bis[3-(α,α-bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)methyl-4-hydroxyphenyl]methane,
4,4'-[4-hydroxy-3,5-bis(2-hydroxybenzyl)methylene]bis[2,6-bis(2-hydroxybenzyl)]phenol,
4,4'-[4-hydroxy-3,5-bis(4-hydroxybenzyl)methylene]bis[2,6-bis(4-hydroxybenzyl)]phenol,
4,4',4''-ethylidine tris [2,6-bis(2-hydroxybenzyl)phenol],
4,4′,4″-ethylidine tris [2,6-bis(4-hydroxybenzyl)phenol],
2,2-bis[3,5-bis(4-hydroxy-3-methylbenzyl)-4-hydroxyphenyl]propane,
1,8,15,22-tetraethyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane,
α,α′,α″,α′″-tetrakis(3,5-dimethyl-4-hydroxyphenyl)-1,4-dimethylbenzene,
4,4'-[1-{4-[1-(3,5-bis(2-hydroxy-5-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2, 6-bis(2-hydroxy-5-isopropylphenyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2,3,5-trimethylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene] Bis[2,6-bis(4-hydroxy-2,3,5-trimethylphenyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(3-sec-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[ 2,6-bis(3-sec-butyl-4-hydroxyphenyl)phenol],
4,4'-[1-{4-[1-(3,5-bis(3-tert-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[ 2,6-bis(3-tert-butyl-4-hydroxyphenyl)phenol],
2,6-bis{[3-(2,4-dihydroxybenzyl)-2,5-dimethyl-4-hydroxy]benzyl}-4-methylphenol,
1,1-bis[5-(2,4-dihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane,
1,1-bis[5-(2,3,4-trihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane,
Examples include 2,2-bis[4,4',4'',4''-tetrakis(3,5-dihydroxymethyl-4-hydroxyphenyl)cyclohexyl]propane.

As carboxylic acids and their derivatives,
3,5-di(α-methylbenzyl)salicylic acid,
4-(2-p-methoxyphenyloxyethoxy) salicylic acid,
4-hydroxyphenylbenzoic acid,
p-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,
N-(m-tolylaminocarbonyl)-methionine,
N-(p-tolylaminocarbonyl)-methionine,
N-(phenylaminocarbonyl)-methionine,
N-(m-tolylaminocarbonyl)-valine,
N-(m-tolylaminocarbonyl)-phenylglycine,
N-(m-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.

Examples of the acidic phosphoric acid ester compound include methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, isodecyl acid phosphate, isotridecyl acid phosphate, oleyl acid phosphate, and tetracosyl acid phosphate. Examples include acid phosphate, monobutyl phosphate, dibutyl phosphate, monoisodecyl phosphate, bis(2-ethylhexyl) phosphate and the like.

Compounds having a phenolic hydroxyl group can exhibit the most effective thermochromic properties, but aromatic carboxylic acids, aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphoric esters, and their metals It may also be a compound selected from salts, 1,2,3-triazoles and derivatives thereof.

The component (c), which is a reaction medium that reversibly causes the electron transfer reaction between the components (a) and (b) in a specific temperature range, will be explained. Examples of the component (c) include esters, ketones, ethers, alcohols, and acid amides.

As for the (c) component, regarding the color density-temperature curve, there is a large hysteresis characteristic (the curve plotting the change in color density due to temperature change may change from a low temperature side to a high temperature side, or from a high temperature side to a low temperature side). A carboxylic acid ester compound that exhibits a ΔT value (melting point - cloud point) of 5°C or more and less than 50°C, which can form a reversible thermochromic composition that exhibits color memory and changes color (different depending on the case of change), for example, Carboxylic acid esters containing substituted aromatic rings in the molecule, esters of carboxylic acids containing unsubstituted aromatic rings and aliphatic alcohols with 10 or more carbon atoms, carboxylic esters containing cyclohexyl groups in the molecule, and esters with 6 or more carbon atoms. Esters of fatty acids and unsubstituted aromatic alcohols or phenols, esters of fatty acids with 8 or more carbon atoms and branched aliphatic alcohols, esters of dicarboxylic acids and aromatic alcohols or branched aliphatic alcohols, dibenzyl cinnamate, heptyl stearate, Didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, dimyristin, distearin, etc. are used.

In addition, fatty acid ester compounds obtained from an odd-numbered aliphatic monohydric alcohol having 9 or more carbon atoms and an even-numbered aliphatic carboxylic acid, n-pentyl alcohol or n-heptyl alcohol, and an even-numbered fatty acid having 10 to 16 carbon atoms. Fatty acid ester compounds having a total of 17 to 23 carbon atoms obtained from group carboxylic acids are also effective.

Specifically, n-pentadecyl acetate, n-tridecyl butyrate, n-pentadecyl butyrate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caprylate, n-undecyl caprylate, n-tridecyl caprylate, n-pentadecyl caprylate, n-heptyl caprate, n-nonyl caprate, n-undecyl caprate, n-tridecyl caprate, n-pentadecyl caprate, n-pentyl laurate, lauric acid n-heptyl, n-nonyl laurate, n-undecyl laurate, n-tridecyl laurate, n-pentadecyl laurate, n-pentyl myristate, n-heptyl myristate, n-nonyl myristate, n- myristate Undecyl, n-tridecyl myristate, n-pentadecyl myristate, n-pentyl palmitate, n-heptyl palmitate, n-nonyl palmitate, n-undecyl palmitate, n-tridecyl palmitate, n-pentadecyl palmitate, n-nonyl stearate, n-undecyl stearate, n-tridecyl stearate, n-pentadecyl stearate, n-nonyl eicosanoate, n-undecyl eicosanoate, n-tridecyl eicosanoate, n-pentadecyl eicosanoate, behenic acid Examples include n-nonyl, n-undecyl behenate, n-tridecyl behenate, and n-pentadecyl behenate.

As the ketones, aliphatic ketones having a total carbon number of 10 or more are effective, such as 2-decanone, 3-decanone, 4-decanone, 2-undecanone, 3-undecanone, 4-undecanone, 5-undecanone, 2-decanone, -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.

In addition, arylalkyl ketones having a total number of carbon atoms of 12 to 24, such as n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradecanophenone, Phenone, 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, cyclohexyl phenyl ketone, benzyl-n-butyl ketone, 4-n-butylacetophenone, n-hexanophenone, 4-isobutylacetophenone, 1-acetonaphthone, 2-acetonaphthone, cyclopentylphenyl ketone etc. can be mentioned.

As the ethers, aliphatic ethers having a total carbon number of 10 or more are effective, such as dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecyl ether, diundecyl ether, didodecyl ether, and ditriether. Decyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, dioctadecyl ether, decanediol dimethyl ether, undecane diol dimethyl ether, dodecane diol dimethyl ether, tridecane diol dimethyl ether, decane diol diethyl ether, undecane diol diethyl ether, etc. can be mentioned.

As alcohols, aliphatic monohydric saturated alcohols having 10 or more carbon atoms are effective, such as decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, heptadecyl Alcohol, octadecyl alcohol, eicosyl alcohol, docosyl alcohol, etc. can be mentioned.

Acid amides include hexanoic acid amide, heptanoic acid amide, octanoic acid amide, nonanoic acid amide, decanoic acid amide, undecanoic acid amide, lauric acid amide, tridecanoic acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, Examples include docosanoic acid amide.

（ここで、Ｒ^１は水素原子又はメチル基を示し、ｑ１は０～２の整数を示し、Ｘ^１のいずれか一方は－（ＣＨ_２）_ｋＯＣＯＲ’又は－（ＣＨ_２）_ｋＣＯＯＲ’、他方は水素原子を示し、ｋは０～２の整数を示し、Ｒ’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はそれぞれ独立に炭素数１～４のアルキル基、メトキシ基、又はハロゲンを示し、ｐ１はそれぞれ独立に０～３の整数を示す。） Further, as the component (iii), a compound represented by the following general formula (1) can also be used.

(Here, R ¹ represents a hydrogen atom or a methyl group, q1 represents an integer of 0 to 2, and either one of X ¹ is -(CH ₂ ) _k OCOR' or -(CH ₂ ) _k COOR', The other represents a hydrogen atom, k represents an integer of 0 to 2, R' represents an alkyl group or alkenyl group having 4 or more carbon atoms, and Y ₁ each independently represents an alkyl group or a methoxy group having 1 to 4 carbon atoms. , or halogen, and p1 each independently represents an integer from 0 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 furthermore, R ₁ is a hydrogen atom, and It is more preferable that m is 0.

（ここでＲ^１ａは、炭素数８以上のアルキル基又はアルケニル基、好ましくは炭素数１０～２４のアルキル基、更に好ましくは炭素数１２～２２のアルキル基である。） Note that among the compounds represented by formula (1), a compound represented by the following general formula (1a) is more preferably used.

(Here, R ^1a is an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, and more preferably an alkyl group having 12 to 22 carbon atoms.)

Specifically, the compounds include 4-benzyloxyphenylethyl octoate, 4-benzyloxyphenylethyl nonanoate, 4-benzyloxyphenylethyl decanoate, 4-benzyloxyphenylethyl undecanoate, and dodecanoic acid. -4-benzyloxyphenylethyl, -4-benzyloxyphenylethyl tridecanoate, -4-benzyloxyphenylethyl tetradecanoate, -4-benzyloxyphenylethyl pentadecanoate, -4-benzyloxyphenylethyl hexadecanoate, heptadecanoic acid Examples include -4-benzyloxyphenylethyl and -4-benzyloxyphenylethyl octadecanoate.

（ここで、Ｒ^２は炭素数８以上のアルキル基又はアルケニル基を示し、ｐ２はそれぞれ独立に０～３の整数を示し、Ｘ^２はそれぞれ独立に炭素数１～４のアルキル基、炭素数１～４のアルコキシ基、又はハロゲンを示す。） Furthermore, a compound represented by the following general formula (2) can also be used as the component (iii).

(Here, R ² represents an alkyl group or alkenyl group having 8 or more carbon atoms, p2 each independently represents an integer of 0 to 3, and X ² each independently represents an alkyl group having 1 to 4 carbon atoms, or an alkenyl group having 8 or more carbon atoms. (1 to 4 alkoxy groups or halogen)

Specifically, the compounds include 1,1-diphenylmethyl octoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, and 1,1-diphenylmethyl dodecanoate. Diphenylmethyl, 1,1-diphenylmethyl tridecanoate, 1,1-diphenylmethyl tetradecanoate, 1,1-diphenylmethyl pentadecanoate, 1,1-diphenylmethyl hexadecanoate, 1,1-diphenylmethyl heptadecanoate, octadecanoic acid An example is 1,1-diphenylmethyl.

（ここで、Ｘ^３はそれぞれ独立に炭素数１～４のアルキル基、メトキシ基、又はハロゲン原子のいずれかを示し、ｐ３はそれぞれ独立に０～３の整数を示し、ｑ３は１～２０の整数を示す。） Furthermore, a compound represented by the following general formula (3) can also be used as the component (iii).

(Here, ^X3 each independently represents an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom, p3 each independently represents an integer of 0 to 3, and q3 represents an integer of 1 to 20. (Indicates an integer.)

Examples of the compounds include diesters of malonic acid and 2-[4-(4-chlorobenzyloxy)phenyl)]ethanol, diesters of succinic acid and 2-(4-benzyloxyphenyl)ethanol, and diesters of succinic acid and 2-(4-benzyloxyphenyl)ethanol. Diester with [4-(3-methylbenzyloxy)phenyl)]ethanol, diester with glutaric acid and 2-(4-benzyloxyphenyl)ethanol, glutaric acid with 2-[4-(4-chlorobenzyloxy)] phenyl)] diester with ethanol, diester with adipic acid and 2-(4-benzyloxyphenyl)ethanol, diester with pimelic acid and 2-(4-benzyloxyphenyl)ethanol, diester with suberic acid and 2-(4- benzyloxyphenyl) ethanol, suberic acid and 2-[4-(3-methylbenzyloxy)phenyl)] diester with ethanol, suberic acid and 2-[4-(4-chlorobenzyloxy)phenyl)] Diester with ethanol, diester with suberic acid and 2-[4-(2,4-dichlorobenzyloxy)phenyl)]ethanol, diester with azelaic acid and 2-(4-benzyloxyphenyl)ethanol, sebacic acid Diester with 2-(4-benzyloxyphenyl)ethanol, diester with 1,10-decanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, diester with 1,18-octadecanedicarboxylic acid and 2-(4-benzyl) Examples include diesters with oxyphenyl)ethanol and diesters with 1,18-octadecanedicarboxylic acid and 2-[4-(2-methylbenzyloxy)phenyl)]ethanol.

（ここで、Ｒ^４はそれぞれ独立に炭素数１～２１のアルキル基又はアルケニル基を示し、ｐ４はそれぞれ独立に１～３の整数を示す。） Furthermore, a compound represented by the following general formula (4) can also be used as the component (iii).

(Here, R ⁴ each independently represents an alkyl group or alkenyl group having 1 to 21 carbon atoms, and p4 each independently represents an integer of 1 to 3.)

Examples of the compounds include a diester of 1,3-bis(2-hydroxyethoxy)benzene and capric acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and undecanoic acid, and a diester of 1,3-bis(2-hydroxyethoxy)benzene and undecanoic acid. - hydroxyethoxy)benzene and lauric acid diester, 1,3-bis(2-hydroxyethoxy)benzene and myristic acid diester, 1,3-bis(2-hydroxyethoxy)benzene and palmitic acid diester, Diester of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanoic acid carboxylic acid, diester of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanoic acid propionic acid, 1,4-bis(hydroxymethoxy) ) diester of benzene and butyric acid, diester of 1,4-bis(hydroxymethoxy)benzene and isovaleric acid, diester of 1,4-bis(2-hydroxyethoxy)benzene and acetic acid, 1,4-bis( Diester of 2-hydroxyethoxy)benzene and propionic acid, diester of 1,4-bis(2-hydroxyethoxy)benzene and valeric acid, diester of 1,4-bis(2-hydroxyethoxy)benzene and caproic acid , diester of 1,4-bis(2-hydroxyethoxy)benzene and caprylic acid, diester of 1,4-bis(2-hydroxyethoxy)benzene and capric acid, 1,4-bis(2-hydroxyethoxy) Examples include diesters of benzene and lauric acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and myristic acid, and diesters of 1,4-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid.

（ここで、Ｘ^５はそれぞれ独立に炭素数１～４のアルキル基、炭素数１～４のアルコキシ基、又はハロゲン原子のいずれかを示し、ｐ５はそれぞれ独立に０～３の整数を示し、ｑ５は１～２０の整数を示す。） Furthermore, a compound represented by the following general formula (5) can also be used as the component (iii).

(Here, X ⁵ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom; q5 indicates an integer from 1 to 20.)

The compounds include diesters of succinic acid and 2-phenoxyethanol, diesters of suberic acid and 2-phenoxyethanol, diesters of sebacic acid and 2-phenoxyethanol, diesters of 1,10-decanedicarboxylic acid and 2-phenoxyethanol, An example is a diester of 1,18-octadecanedicarboxylic acid and 2-phenoxyethanol.

（ここで、Ｒ^６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^６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、ｑ６は０又は１を示す。） Furthermore, a compound represented by the following general formula (6) can also be used as the component (iii).

(Here, R ⁶ 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 ⁶ is a hydrogen atom; represents an alkyl group, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, and q6 represents 0 or 1.)

The compounds include decyl 4-phenylbenzoate, lauryl 4-phenylbenzoate, myristyl 4-phenylbenzoate, cyclohexylethyl 4-phenylbenzoate, octyl 4-biphenylacetate, nonyl 4-biphenylacetate, and 4-biphenylacetic acid. Decyl, lauryl 4-biphenylacetate, myristyl 4-biphenylacetate, tridecyl 4-biphenylacetate, pentadecyl 4-biphenylacetate, cetyl 4-biphenylacetate, cyclopentyl 4-biphenylacetate, cyclohexylmethyl 4-biphenylacetate, hexyl 4-biphenylacetate , and cyclohexylmethyl 4-biphenylacetate.

（ここで、Ｒ^７は炭素数３～１８のアルキル基、または炭素数３～１８の脂肪族アシル基のいずれかを示し、Ｘ^７は水素原子、炭素数１～３のアルキル基、炭素数１または２のアルコキシ基、ハロゲン原子のいずれかを示し、Ｙ^７は水素原子、メチル基のいずれかを示し、Ｚ^７は水素原子、炭素数１～４のアルキル基、炭素数１又または２のアルコキシ基、ハロゲン原子のいずれかを示す。） Furthermore, a compound represented by the following general formula (7) can also be used as the component (iii).

(Here, R ⁷ represents either an alkyl group having 3 to 18 carbon atoms or an aliphatic acyl group having 3 to 18 carbon atoms, and X ⁷ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, 1 or 2 alkoxy group or halogen atom, Y ⁷ represents a hydrogen atom or a methyl group, Z ⁷ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, 1 or 2 carbon atoms (Indicates either an alkoxy group or a halogen atom.)

Examples of the above compounds include phenoxyethyl 4-butoxybenzoate, phenoxyethyl 4-pentyloxybenzoate, phenoxyethyl 4-tetradecyloxybenzoate, ester of phenoxyethyl 4-hydroxybenzoate and dodecanoic acid, and phenoxyethyl vanillate. An example is dodecyl ether.

（ここで、Ｒ^８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^８は、それぞれ独立にアルキル基、アルコキシ基、ハロゲン原子のいずれかを示し、ｐ８は０または１を示し、ｑ８は０～５を示し、ｒ８は０～４を示す。） Furthermore, a compound represented by the following general formula (8) can also be used as the component (iii).

(Here, R ⁸ 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 ⁸ each independently represents an alkyl group or an alkoxy represents either a group or a halogen atom, p8 represents 0 or 1, q8 represents 0 to 5, and r8 represents 0 to 4.)

Examples of the above compounds include benzoate ester of octyl p-hydroxybenzoate, benzoate ester of decyl p-hydroxybenzoate, p-methoxybenzoate ester of heptyl p-hydroxybenzoate, and o-dodecyl p-hydroxybenzoate. Examples include methoxybenzoic acid ester and benzoic acid ester of cyclohexylmethyl p-hydroxybenzoate.

（ここで、Ｒ^９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を示し、Ｘ^９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、ハロゲン原子を示し、ｐ９は１～３の整数を示す。） Furthermore, a compound represented by the following general formula (9) can also be used as the component (iii).

(Here, R ⁹ represents 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 ⁹ is a hydrogen atom; represents an alkyl group, methoxy group, ethoxy group, or halogen atom, and p9 represents an integer from 1 to 3.)

Examples of the compounds include a diester of 4-phenylphenol ethylene glycol ether and cyclohexane carboxylic acid, a diester of 4-phenylphenol diethylene glycol ether and lauric acid, a diester of 4-phenylphenol triethylene glycol ether and cyclohexane carboxylic acid, - Diester of phenylphenol ethylene glycol ether and octanoic acid, diester of 4-phenylphenol ethylene glycol ether and nonanoic acid, diester of 4-phenylphenol ethylene glycol ether and decanoic acid, 4-phenylphenol ethylene glycol ether and myristin Examples include diesters with acids.

Furthermore, specific alkoxyphenol compounds having a linear or side chain alkyl group having 3 to 18 carbon atoms are used as electron-accepting compounds (Japanese Unexamined Patent Application Publication No. 11-129623, JP-A No. 11-5973), Heat coloring type using hydroxybenzoic acid ester (Japanese Patent Publication No. 2001-105732) or gallic acid ester (Japanese Patent Publication No. 51-44706, Japanese Patent Application Publication No. 2003-253149). A microcapsule pigment containing a reversible thermochromic composition (which disappears upon cooling) can also be used.

The blending ratio of components (a), (b), and (c) depends on the concentration, discoloration temperature, discoloration form, and type of each component, but generally the component ratio that provides the desired discoloration characteristics is: 0.1 to 50 parts by mass of component (B), preferably 0.5 to 20 parts by mass, and 1 to 800 parts by mass of component (c), preferably 5 to 200 parts by mass of component (B), per 1 part by mass of component (A). is within the range of

Here, a colorant such as a non-thermochromic dye or pigment may be blended into the microcapsule pigment or the ink to exhibit a tautochromic color change from colored (1) to colored (2). can.

The method for encapsulating the thermochromic composition in microcapsules is not particularly limited, and examples include interfacial polymerization, interfacial polycondensation, in-situ polymerization, in-liquid curing coating, phase separation from an aqueous solution, and encapsulation from an organic solvent. There are phase separation methods, melt dispersion cooling methods, air suspension coating methods, spray drying methods, etc., and these methods are appropriately selected depending on the application.

The wall film of the microcapsule pigment is made of a polymer having at least one of a urea bond and a urethane bond in the repeating unit. Since the polymer constituting the wall film has the above-mentioned bond in the repeating unit, it exhibits excellent properties through interaction with the polyurethane described below.

The polymer can be synthesized, for example, by combining an isocyanate prepolymer with a polyol or a polyamine, and can be used in the present invention by encapsulating the dye, pigment, or thermochromic composition in microcapsules. microcapsule pigments can be created.

Furthermore, depending on the purpose, a secondary resin film can be provided on the surface of the microcapsules to impart durability or to modify the surface characteristics for practical use.

The microcapsule pigment used has an average particle diameter of preferably 0.1 to 5.0 μm, more preferably 0.1 to 4.0 μm, and still more preferably 0.5 to 3.0 μm.

The mass ratio of the reversible thermochromic composition to the microcapsule wall film is 7:1 to 1:1 (mass ratio), preferably 6:1 to 1:1. It is preferable that the range is satisfied.

If the average particle diameter of the microcapsule pigment exceeds 5.0 μm, it will be difficult to obtain a smooth writing feeling when used in a writing instrument, and if the average value of the maximum outer diameter is less than 0.1 μm, it will be difficult to exhibit high density color development. .

A microcapsule pigment having an average particle diameter within the above range, particularly within the range of 0.5 to 3.0 μm, exhibits high color density and tends to provide good ejectability when used in writing instruments.

If the ratio of the reversible thermochromic composition to the wall film exceeds the above range, the thickness of the wall film becomes too thin and the resistance to pressure and heat tends to decrease, and the ratio of the wall film to the reversible thermochromic composition If it exceeds the above range, color density and sharpness during color development are likely to deteriorate.

To measure the average particle diameter, the area of the particle is determined using the image analysis particle size distribution measurement software "Macview" manufactured by Mountech, and the projected area circle equivalent diameter (Heywood diameter) is calculated from the area of the particle area. This value is calculated and measured as the average particle diameter of particles equivalent to a sphere with equal volume.

In addition, if the particle diameter of all or most of the particles exceeds 0.2 μm, use a particle size distribution analyzer (manufactured by Beckman Coulter Co., Ltd., product name: Multisizer 4e) to measure the equivalent volume of an equal volume sphere by the Coulter method. It is also possible to measure the average particle size of the particles. Furthermore, we used a laser diffraction/scattering particle size distribution measuring device (device name: LA-300, manufactured by Horiba, Ltd.) that was calibrated based on the values measured using a standard sample or a measuring device using the Coulter method. The volume-based particle size and the average particle size (median size) may be measured using the following method.

The content of the microcapsule pigment is preferably 5 to 30% by weight, more preferably 10 to 25% by weight based on the total weight of the ink composition. When the content is within the above range, it becomes easy to make handwriting clear while suppressing dry-up of the pen tip.

(Polyurethane emulsion)
The ink composition contains a polyurethane emulsion in which polyurethane is dispersed. Polyurethane is also uniformly dispersed in the ink composition.
As the polyurethane emulsion, one in which a polyurethane film formed only from the polyurethane emulsion has a Young's modulus of less than 900 MPa is used.

Polyurethane makes the handwriting formed on the paper surface clear when the ink composition is discharged onto the paper surface. This is because polyurethane has a high affinity with the urea bonds and urethane bonds in the polymer that forms the microcapsule pigment wall film, so polyurethane allows the microcapsule pigment to adsorb to the paper fibers on the paper surface through itself. It is presumed that this is because the improved fixation of the microcapsule pigment on the surface improves the color development of handwriting.
Furthermore, the handwriting formed with the ink composition of the present invention has good thermochromic properties, and when the microcapsule pigment has heat decoloring properties, heating tools such as electric heating tools equipped with resistance heating elements, hair dryers, etc. In addition, it is possible to form handwriting with less residual color due to rubbing by the friction member. This is because the microcapsule pigment is prevented from penetrating into the paper and is fixed on the paper surface, so when heat is applied to the handwriting or when the handwriting is cooled, the microcapsule pigment or The heat conductivity from the microcapsule pigment is good, and when the ejected ink dries, the polyurethane forms a film to form handwriting with appropriate flexibility, and when the handwriting is rubbed, This is thought to be due to the fact that moderate distortion increases frictional resistance, making it easier to generate frictional heat that discolors the microcapsule pigment during rubbing.

If the Young's modulus of a polyurethane film formed from only a polyurethane emulsion is 900 MPa or more, it is not suitable for use as an ink composition because handwriting becomes difficult to discolor due to heat when rubbed.
Moreover, Young's modulus is preferably 1 MPa or more, more preferably 5 MPa or more.
Specific examples of polyurethane emulsions that can be applied to the ink composition include: trade name: Superflex 300 (Young's modulus of polyurethane film: 5.4 MPa), trade name: Superflex 420NS (Young's modulus of polyurethane film: 565 MPa), trade name : Superflex 470 (Young's modulus of polyurethane film: 13 MPa), trade name: Superflex 150HS (Young's modulus of polyurethane film: 798 MPa) manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
Polyurethane emulsions that can be applied to the ink composition are not limited to these.
The Young's modulus of the polyurethane film in the present invention is a value measured in accordance with JIS K 7161-1:2014/ISO527-1:2012. Specifically, a polyurethane film with a thickness of 500 μm was prepared using a polyurethane emulsion under the conditions of pre-drying at room temperature for 15 hours, main drying at 80°C for 6 hours, and 20 minutes at 120°C. Using a dynamic viscoelasticity measuring device (trade name: Rheogel-E4000, manufactured by UBM), it was pulled at a speed of 1 mm/min, and in the linear region (inclination between two points of strain 0.05% and 0.25%). It is determined by measuring the elastic modulus.

The polyurethane emulsion that can be applied to the present invention is not particularly limited as long as the Young's modulus of the polyurethane film is within the above range, and any emulsion can be applied to the ink composition.

The content of the polyurethane emulsion in the ink composition is preferably 0.1 to 5% by mass, more preferably 0.2 to 3% by mass, based on the total mass of the ink composition in terms of the mass of polyurethane. . When the content is within the above range, it is easy to improve the clarity of handwriting and the heat discoloration property of handwriting. If the content is more than 5% by mass, the ink discharge properties may deteriorate, and if the content is less than 0.1% by mass, the effect of improving the clarity of handwriting and the thermochromic property of handwriting is poor.

The ink composition according to the present invention may contain additives such as a shear thinning agent, a pH adjuster, a preservative, or a fungicide, if necessary.

Water-soluble or dispersible substances are effective as shear thinning agents, such as xanthan gum, welan gum, zeta sea gum, diutan gum, macrohomopsis gum, and organic acid-modified heteropolysaccharides whose constituent monosaccharides are glucose and galactose. succinoglycan (average molecular weight of about 1 million to 8 million), guar gum, locust bean gum and its derivatives, hydroxyethyl cellulose, alginate alkyl esters, and methacrylic acid alkyl esters with a molecular weight of 100,000 to 150,000. carbohydrates with gelling ability extracted from seaweed such as glucomannan, agar and carrageenan, poly N-vinyl-carboxylic acid amide cross-linked products, benzylidene sorbitol and benzylidene xylitol or derivatives thereof, cross-linked acrylic acid polymers, Examples include inorganic fine particles, nonionic surfactants with an HLB value of 8 to 12, and metal salts and amine salts of dialkyl sulfosuccinic acid. Furthermore, a combination of N-alkyl-2-pyrrolidone and an anionic surfactant may be added to the ink composition.

Examples of the pH adjuster include inorganic salts such as ammonia, sodium carbonate, sodium phosphate, sodium hydroxide, and sodium acetate, organic basic compounds such as water-soluble amine compounds such as triethanolamine and diethanolamine, phosphoric acid, and lactic acid. , acidic compounds such as amino acids, and the like.

As preservatives or antifungal agents, 2-methyl-4-isothiazolin-3-one, 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 2-methyl- 4,5-trimethylene-4-isothiazolin-3-one, N-(n-butyl)-1,2-benzisothiazolin-3-one, sodium 2-pyridinethiol-1-oxide, 3-iodo-2-propynylbutyl Examples include carbamate, benzotriazole and phenol, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine, and the like.

Examples of the rust preventive include benzotriazole and its derivatives, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, sodium thiosulfate, saponin, and dialkylthiourea. Further, as the water-soluble resin, acrylic resin, alkyd resin, polyvinylpyrrolidone, polyvinyl alcohol, etc. can be used. Further, as a resin emulsion, an emulsion containing acrylic resin, styrene-butadiene resin, polyester resin, vinyl acetate resin, etc. can be added.

Furthermore, fluorine-based surfactants that improve the permeability of solvents, phosphate ester-based surfactants that improve the lubricity of ballpoint pen tips, other nonionic, anionic, and cationic surfactants, and dimethylpolysiloxane It is also possible to add antifoaming agents such as.

式中、Ｒ^１０は炭化水素基、Ｒ^１１はアルキレン基である。また、ｎは１以上の整数である。

式中、Ｒ^１２は炭化水素基、Ｒ^１３およびＲ^１４は互いに異なるアルキレン基である。また、ｏ、ｐは１以上の整数である。 The phosphate ester surfactant that can be applied to the ink composition is a compound represented by the following formula (10).
In the formula, E ¹ , E ² , and E ³ are any one selected from the functional groups and hydroxyl groups shown in the following formulas (11) and (12), and at least one selected from E ¹ , E ² , and E ³ . The species is a functional group shown in formula (11) or (12).

In the formula, R ¹⁰ is a hydrocarbon group, and R ¹¹ is an alkylene group. Further, n is an integer of 1 or more.

In the formula, R ¹² is a hydrocarbon group, and R ¹³ and R ¹⁴ are different alkylene groups. Further, o and p are integers of 1 or more.

A preferable phosphate ester surfactant for the ink composition is a phosphate ester surfactant in which R ¹⁰ and R ¹² are an alkyl group, an alkenyl group, or an aryl group, and more preferably, R ¹⁰ is an alkyl group. a phosphoric acid ester surfactant, in which R ¹¹ is an ethylene group, and R ¹² is an alkyl group, alkenyl group, or aryl group, and R ¹³ and R ¹⁴ are A phosphoric acid ester surfactant in which either one of them is an ethylene group and the other is a propylene group or a trimethylene group.

The phosphate ester surfactant includes a monoester type surfactant in ^which one of E ¹ to E ³ is a functional group represented by formula ( ¹¹ ) or (12); Any two selected from are diester type functional groups represented by formulas (11) and (12), or all of E ¹ to E ³ are functional groups represented by formulas (11) and (12). Any of the functional groups shown, which is a triester type, may be used alone, or two or more types selected from the monoester type, diester type, and triester type may be used in combination.
Further, the monoester type or diester type phosphate ester surfactant may be an alkali metal salt, an ammonium salt, an amine salt, an alkanolamine salt, or the like.

The aqueous ink composition according to the present invention can be produced by any conventionally known method. Specifically, the above-mentioned components can be mixed in required amounts and mixed using various stirrers such as a propeller stirrer, homodisper, or homomixer, and various dispersion machines such as a bead mill.

A writing instrument containing the ink will be explained.
When filling a ballpoint pen, the structure and shape of the ballpoint pen itself are not particularly limited. For example, the ink storage tube may include an ink storage tube filled with shear-thinning ink in the barrel, and the ink storage tube may hold the ball at the tip. An example of a ballpoint pen is a ballpoint pen that communicates with a ballpoint pen tip attached to the ink and further has a liquid stopper for preventing backflow in close contact with the end surface of the ink.
To explain the ballpoint pen tip in more detail, it is a tip formed by holding a ball in a ball holding part that is formed by pressing and deforming the tip of a metal pipe inward from the outer surface, or a tip formed by cutting a metal material with a drill or the like. A chip in which a ball is held in a ball holding part formed by a metal or plastic chip, 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 moved forward by a spring body. An energized one can be applied.
The ball is made of cemented carbide, stainless steel, ruby, ceramic, resin, rubber, etc. and has a diameter of 0.3 to 2.0 mm, preferably 0.3 to 1.5 mm, more preferably 0.3 to 1.0 mm. Applicable to diameters.
For the ink storage tube that stores the ink, a molded body made of thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, nylon, or a metal tubular body is used, for example.
In addition to directly connecting the chip to the ink storage tube, the ink storage tube and the chip may be connected via a connecting member.
The ink storage tube may be in the form of a refill, and the refill may be accommodated in a cylinder made of resin, metal, etc., or the cylinder itself with a tip attached to the tip may be used as the ink storage body. Ink may be directly filled into the barrel.
In addition, when the ink composition is stored in a retractable ballpoint pen, the structure and shape of the retractable ballpoint pen are not particularly limited, and the writing tip provided in the ballpoint pen refill is exposed to the outside air. Any structure can be used as long as the writing tip is housed in a cylinder and the writing tip protrudes from the opening of the barrel by the operation of the ejection/retraction mechanism.
Examples of operating methods for the retracting mechanism include a knocking type, a rotating type, and a sliding type.
The knock type has a knock part on the rear end of the barrel or the side surface of the barrel, and the ballpoint pen tip is moved out and out of the front end opening of the barrel by pressing the knock part, or a clip part provided on the barrel. An example of a configuration is such that the ballpoint pen tip is moved out and out of the front end opening of the barrel by pressing .
The rotary type has a rotating part at the rear part of the barrel, and by rotating the rotating part, the ballpoint pen tip can be moved in and out of the front end opening of the barrel.
The sliding type has a slide part on the side surface of the barrel, and by operating the slide, the ballpoint pen tip is moved in and out of the front end opening of the barrel, or by sliding a clip part provided on the barrel, An example of this configuration is a configuration in which the ballpoint pen tip is made to protrude and retract from the front end opening of the barrel.
The retractable ballpoint pen is a compound type retractable ballpoint pen in which a plurality of ballpoint pen refills are housed in a barrel, and the writing tip of one of the ballpoint pen refills comes out and retracts from the front end opening of the barrel by the operation of a retracting mechanism. You can.

An ink backflow preventer is filled at the rear end of the ink stored in the ink storage tube.
The ink backflow preventer composition comprises a non-volatile liquid or a hardly volatile liquid.
Specifically, petrolatum, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or cooligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Examples include polyether-modified silicone oil and fatty acid-modified silicone oil, and one type or two or more types can be used in combination.
It is preferable that the nonvolatile liquid and/or the hardly volatile liquid be thickened to a suitable viscosity by adding a thickener, and the thickener may include silica whose surface has been hydrophobically treated, or silica whose surface has been methylated. Fine particle silica, aluminum silicate, swellable mica, clay thickeners such as hydrophobically treated bentonite and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, Examples include dextrin-based compounds such as fatty acid amide, amide-modified polyethylene wax, hydrogenated castor oil, and fatty acid dextrin, and cellulose-based compounds.
Furthermore, the liquid ink backflow preventer and the solid ink backflow preventer may be used together.

When filling a marking pen, the structure and shape of the marking pen itself are not particularly limited. A marking pen in which the ink absorbing body is impregnated with a cohesive ink, the marking pen having a marking pen tip attached to the shaft cylinder directly or through a relay member, and the ink absorbing body and the tip being connected. Examples include a marking pen in which a tip and an ink storage tube are disposed via a valve body that opens when the tip is pressed, and ink is directly stored in the ink storage tube.
The chip is a porous member with continuous pores selected from conventional general-purpose materials such as resin-processed fibers, fusion-processed heat-fusible fibers, and felt bodies with a porosity in the range of approximately 30 to 70%; One end is processed into a shape according to the purpose, such as a bullet shape, a rectangular shape, a chisel shape, etc., and it is put into practical use.
The ink storage body is made up of crimped fibers bundled in the longitudinal direction, and is constructed by incorporating it into a covering such as a plastic cylinder or film, and adjusting the porosity to a range of approximately 40 to 90%. be done.
Further, the valve body can be of a conventionally general-purpose pumping type, but it is preferable that the valve body is set to a spring pressure that can be pressed and released by pen pressure.

Furthermore, the form of the ballpoint pen or marking pen is not limited to the one described above, and may be a double-headed writing instrument equipped with tips of different shapes or pen nibs that draw out ink of different colors.

Note that handwriting obtained by writing on a surface to be written using a writing instrument containing the ink composition for writing instruments can be discolored by a cooling tool or a heating tool.
Examples of the cooling device include a cold color changing device using a Peltier element, a cold color changing device filled with a refrigerant such as cold water or ice chips, and a refrigerator or a freezer.
Examples of the heating tool include an electrical heating discoloration tool equipped with a resistance heating element, a heat discoloration tool filled with hot water, etc., and a hair dryer. Preferably, a friction member is used as a means for changing color by a simple method. used.

As the friction member, an elastic body such as an elastomer or a plastic foam that has a rich elastic feel and can generate appropriate friction and generate frictional heat during rubbing is suitable.
It is also possible to rub the handwriting using an eraser, but since eraser scum is generated during friction, the above-mentioned friction member that hardly generates eraser scum is preferably used.
As the material of the friction member, silicone resin, SEBS resin (styrene ethylene butadiene styrene block copolymer), polyester resin, etc. are used.
Although a writing instrument set can be obtained by combining the friction member with a writing instrument and a separate arbitrary-shaped member (friction body), providing the friction member on the writing instrument provides excellent portability.
In the case of a writing instrument equipped with a cap, the location where the friction member is provided is not particularly limited, but for example, if the cap itself is formed from the friction member, the barrel itself is formed from the friction member, or a clip is provided The clip itself can be formed of a friction member, or a friction member can be provided at the tip (top) of the cap or the rear end of the barrel (the part where the writing tip is not provided).
In the case of a retractable writing instrument, the location where the friction member is provided is not particularly limited, but for example, the barrel itself may be formed from the friction member, or if a clip is provided, the clip itself may be formed from the friction member, A friction member can be provided near the opening of the barrel, at the rear end of the barrel (the part where the writing tip is not provided), or at the knock portion.
Note that it is also possible to provide two or more types of friction members.

Examples will be described below, but the present invention is not limited to these examples.
Table 1 shows the compositions of the water-based inks of Examples and Comparative Examples. Note that the composition values in the table indicate parts by mass.
In addition, in this example, the average particle diameter was measured using the laser diffraction/scattering particle size distribution measuring device (device name: LA-300, Horiba Co., Ltd.), which was calibrated by the Coulter method (electrical detection band method). (manufactured by Seisakusho) to measure the average particle diameter (median diameter) and particle diameter on a volume basis.

The contents of the raw materials in the table are explained according to the note numbers.
(1) Black microcapsule pigment (a) 4.5 parts of 2-(2-chloroanilino)-6-di-n-butylaminofluorane as component, 2,2-bis(4-hydroxyphenyl) as component (b) ) 5.0 parts of hexafluoropropane, 50 parts of 4-benzyloxyphenylethyl decanoate as component (c). 0 parts of a reversible thermochromic composition was uniformly dissolved by heating, and 40.0 parts of an aromatic polyvalent isocyanate prepolymer as a wall material and 50.0 parts of a co-solvent were added. A mixed solution of 0 parts was emulsified and dispersed in a 10% polyvinyl alcohol aqueous solution to form fine droplets, and after stirring was continued while heating, 2.5 parts of a water-soluble aliphatic modified polyamine was added, and the mixture was further stirred. This was followed to obtain a microcapsule pigment suspension.
A microcapsule pigment was obtained by filtering the suspension using a filter press machine.
The average particle diameter of the microcapsule pigment is 2.3 μm, and the behavior has a hysteresis characteristic of t ₁ :-20°C, t ₂ :-9°C, t ₃ : 40°C, t ₄ : 57°C, and ΔH63°C. The color changed reversibly from black to colorless and from colorless to black.
(2) Blue microcapsule pigment (A) 2.0 parts of 3-(4-diethylamino-2-hexyloxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide as component , 8.0 parts of 2,2-bis(4-hydroxyphenyl)hexafluoropropane as component (b), and 50.0 parts by mass of 4-benzyloxyphenylethyl decanoate as component (c). The composition was uniformly heated and dissolved, and 40.0 parts of an aromatic polyvalent isocyanate prepolymer and 50.0 parts of a co-solvent were added as a wall film material. A mixed solution of 0 parts was emulsified and dispersed in a 10% polyvinyl alcohol aqueous solution to form fine droplets, and after stirring was continued while heating, 2.5 parts of a water-soluble aliphatic modified polyamine was added, and the mixture was further stirred. This was followed to obtain a microcapsule pigment suspension.
A microcapsule pigment was obtained by filtering the suspension using a filter press machine. The average particle diameter of the microcapsule pigment is 2.3 μm, and the behavior has a hysteresis characteristic of t ₁ :-14°C, t ₂ :-6°C, t ₃ : 48°C, t ₄ : 60°C, and ΔH64°C. The color changed reversibly from blue to colorless and from colorless to blue.
(3) Dextrin (manufactured by Sanwa Starch Industries Co., Ltd., product name: Sundec #70)
(4) Polyoxyalkylene styrenated phenyl ether phosphate ester (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., product name: Plysurf AL, mixture of monoester type and diester type)
(5) Benzisothiazolin-3-one (manufactured by Lonza Japan, product name: Proxel XL-2)
(6) Fluorescent pigment dispersion (manufactured by Nihon Fluoro Chemical Co., Ltd., product name: Lumikol NKW-2306H, water dispersion of styrene acrylic resin particles colored with fluorescent dye, active ingredient 45% by mass)
(7) Manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Superflex 300 (active ingredient 30% by mass, Young's modulus of polyurethane film: 5.4 MPa)
(8) Manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Superflex 420NS (active ingredient 32% by mass, Young's modulus of polyurethane film: 565 MPa)
(9) Manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Superflex 470 (active ingredient 38% by mass, Young's modulus of polyurethane film: 13 MPa)
(10) Manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Superflex 150HS (active ingredient 38% by mass, Young's modulus of polyurethane film: 798 MPa)
(11) Manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Superflex 130 (active ingredient 35% by mass, Young's modulus of polyurethane film: 1612 MPa)
(12) Acrylic resin emulsion (manufactured by Nissin Kagaku Kogyo Co., Ltd., trade name: Vinibran 2585, active ingredient: 45% by mass)

Preparation of Ink Each component was added to water and stirred for 1 hour at 2000 rpm using a disper, then xanthan gum or succinoglycan was added and stirred for another 1 hour to prepare each ink.

Production of Ballpoint Pen for Test A ballpoint pen for test was produced using the inks produced in the Examples and Comparative Examples.
The ballpoint pen containing the ink was Frixion Ball 07 (trade name, manufactured by Pilot Corporation).

The following tests were conducted using the ballpoint pen manufactured in the above-mentioned ballpoint pen manufacturing process.
-Evaluation of handwriting clarity Characters were written on old JIS P3201 writing paper A (written characters: Eternal), and the handwriting was visually confirmed.
〇…The outline of the characters is clear and the color is dark.
×...The outline of the characters is unclear. Also, the color is pale.

-Evaluation of heat discoloration of handwriting The handwriting formed in the evaluation of handwriting clarity was rubbed with a friction material for Frixion Ball 07, and the decolorization of the handwriting was confirmed. Note that the load applied to the handwriting during rubbing was 200 g. As for the evaluation criteria, 〇 was considered a pass, and △ and × were considered a fail.
○...The handwriting became invisible after one scratch.
△...The handwriting was no longer visible after 2 to 3 scratches.
×...Handwriting is visible after 3 rubbings.
The results of each of the above tests are shown in the table below.

Claims (3)

An ink composition comprising a thermochromic microcapsule pigment having a wall film made of a polymer and containing a thermochromic composition, a polyurethane emulsion, and water, the polymer having a urea bond or a urethane bond. A polyurethane film having at least one of the polyurethane emulsions in a repeating unit and formed solely from the polyurethane emulsion has a Young's modulus of less than 900 MPa as measured in accordance with JIS K 7161-1:2014/ISO527-1:2012. A thermochromic water-based ink composition for writing instruments, characterized by: A reversible thermochromic composition in which the thermochromic composition comprises (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color-forming reaction of both of the above occurs. The aqueous ink composition according to claim 1, which is a color-changing composition. A writing instrument containing the aqueous ink composition according to claim 1 or 2.