Reversible thermochromic aqueous ink composition for writing implements and writing implements containing the same

Abstract

To provide an aqueous ink composition for a reversible thermochromic writing instrument which enables stable formation of handwriting having thermochromism, and is excellent in overwriting property and dry-up resistance, and a writing instrument containing the ink composition.SOLUTION: There are provided: an aqueous ink composition for a reversible thermochromic writing instrument which includes a reversible thermochromic microcapsule pigment including a reversible thermochromic composition composed of (i) an electron-donating colorable organic compound, (ii) an electron-accepting compound, and (iii) a reaction medium for determining respective temperatures causing the respective color reactions of both of the compounds (i) and (ii), a substance represented by general formula (1), a shear viscosity-reducing imparting agent, and water; and a writing instrument containing the aqueous ink composition for a reversible thermochromic writing instrument.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reversible thermochromic aqueous ink composition for a writing instrument and a writing instrument containing the same. [Background technology]

[0002] In recent years, water-based inks for writing instruments, which use a microencapsulated pigment containing a thermochromic composition as a colorant, have become known and are used in ballpoint pens and the like (see, for example, Patent Document 1). The ink of the above-mentioned prior art is an ink in which the shear-thinning substance improves the dispersion stability of the thermochromic microcapsule pigment and the ink dischargeability during writing, and it is possible to stably form clear handwriting with thermochromic properties. Furthermore, handwriting formed with the ink can be thermally erased by rubbing it with an elastic body or the like, and it is possible to correct characters or the like by rewriting on the erased handwriting with the ink. However, the inks mentioned above do not have good performance in overwriting handwriting, that is, writing over a handwritten mark with the same ink as that used to form the handwritten mark, and it has sometimes been difficult to form clear overwritten handwritten marks by overwriting.

[0003] Furthermore, since the thermochromic microencapsulated pigment does not have sufficient coloring power compared to common colorants such as organic pigments and carbon black, the concentration of the microencapsulated pigment must be increased in order for the ink to achieve sufficient color density, and in such a case, solid components such as the microencapsulated pigment tend to precipitate when the water in the ink evaporates. When such precipitation occurs in the ballpoint pen tip, the ball may stick, making it difficult to rewrite (so-called drying up).

[0004] As described above, the inks of the prior art have problems, and there is still room for further improvement in performance. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-124993 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a reversibly thermochromic aqueous ink composition for a writing instrument, which is an ink capable of stably forming clear handwriting with thermochromic properties and has excellent overwriting properties and resistance to drying up, and a writing instrument containing the same. [Means for solving the problem]

[0007] The present invention provides "1. A reversibly thermochromic water-based ink composition for a writing instrument, comprising: (a) an electron-donating color-forming organic compound; (b) an electron-accepting compound; and (c) a reversibly thermochromic microcapsule pigment encapsulating a reversibly thermochromic composition consisting of a reaction medium that determines the temperature at which the color-forming reactions of (a) and (b) occur; a substance represented by the following general formula (1); a shear-thinning agent; and water. [ka] In the formula, R1 and R2 are independently an alkyl group or an alkenyl group having 8 to 20 carbon atoms, and X 1、 X 2、 X3 is independently hydrogen, an alkali metal, ammonium, or an alkanolamine. 2. The ink composition according to item 1, wherein the content of the substance represented by the general formula (1) is 0.01 to 2.0 mass % based on the total mass of the ink composition. 3. The ink composition according to item 1 or 2, wherein the shear thinning agent is a polysaccharide. 4. The ink composition according to claim 3, wherein the polysaccharide is succinoglycan and / or xanthan gum. 5. A writing instrument containing the ink composition according to any one of items 1 to 4. 6. A writing implement according to item 5, which is provided with a friction member. 7. A writing instrument according to claim 5 or 6, which is a ballpoint pen. 8. A ballpoint pen refill containing the ink composition according to any one of items 1 to 4. [Effects of the Invention]

[0008] The present invention provides a reversibly thermochromic aqueous ink composition for a writing instrument, which is an ink that can stably form clear handwriting with thermochromic properties and has excellent overwriting properties and resistance to drying up, and a writing instrument containing the same. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a graph illustrating the hysteresis characteristics in the color density-temperature curve of a reversibly thermochromic composition that is heat-discolorable. [Figure 2] 1 is a graph illustrating the hysteresis characteristics in the color density-temperature curve of a heat-discolorable, reversible thermochromic composition having color memory properties. [Figure 3] 1 is a graph illustrating the hysteresis characteristics in the color density-temperature curve of a reversibly thermochromic composition that develops color over time. DETAILED DESCRIPTION OF THE INVENTION

[0010] The reversible thermochromic aqueous ink composition for a writing instrument according to the present invention (hereinafter sometimes referred to as the "ink composition") contains at least a reversible thermochromic microencapsulated pigment, water, and a substance represented by general formula (1). Each component constituting the ink composition according to the present invention will be described below. In this specification, writing over handwriting with the same ink as that used to form the handwriting may be referred to as overwriting.

[0011] The ink composition contains a substance represented by the following general formula (1). [ka] In the formula, R1 and R2 are independently an alkyl group or an alkenyl group having 8 to 20 carbon atoms, and X 1、 X 2、X3 is independently hydrogen, an alkali metal, ammonium, or an alkanolamine. The substance represented by the general formula (1) can produce clear handwriting with reduced smearing and interruption when overwriting with an ink containing a reversible thermochromic microencapsulated pigment. Although the reason for this is unclear, it is presumed that the substance can improve the wettability of the ink containing the reversible thermochromic microencapsulated pigment and the ink adhesion to handwriting formed with the ink containing the reversible thermochromic microencapsulated pigment, thereby enhancing the ability to form overwriting handwriting when overwriting.

[0012] The substance represented by the general formula (1) can also improve the ink's resistance to drying up, and can prevent the ball from sticking and hindering rewriting when water evaporates from the ink in the ballpoint pen tip and solid components such as the microencapsulated pigment and shear-thinning agent in the ink precipitate in the process. Furthermore, the substance has the effect of increasing lubricity, which can smooth the rotation of the ball and result in good ink ejection from the ballpoint pen tip.

[0013] Considering the above-mentioned need to make the overwritten handwriting clear with reduced smearing and interruption, and to improve resistance to dry-up, R1 and R2 in general formula (1) are preferably alkyl or alkenyl groups having 10 to 16 carbon atoms, and more preferably alkyl or alkenyl groups having 10 to 14 carbon atoms. Substances represented by general formula (1) having such functional groups are excellent in making the overwritten handwriting clear and improving resistance to dry-up, and also exhibit excellent affinity for the microencapsulated pigment, thereby further enhancing the dispersibility of the reversible thermochromic microencapsulated pigment.

[0014] The content of the substance represented by general formula (1) is preferably 0.01 to 2.0 mass% based on the total mass of the ink composition, more preferably 0.02 to 1.5 mass%, even more preferably 0.05 to 1 mass%, and particularly preferably 0.05 to 0.5 mass%. When the content is within the above range, it is easy to make overwritten handwriting clear and easy to improve resistance to dry-up.

[0015] The ink composition according to the present invention contains a reversible thermochromic microencapsulated pigment (hereinafter sometimes referred to as "microencapsulated pigment") as a colorant.

[0016] The microcapsule pigment used in the ink composition of the present invention encapsulates a reversible thermochromic composition, which can be a thermally decolorizable (decolorized by heating and colored by cooling) reversible thermochromic composition containing at least three essential components: (i) an electron-donating color-forming organic compound, (ii) an electron-accepting compound, and (iii) a reaction medium that determines the temperature at which the color-forming reaction between components (i) and (ii) occurs.

[0017] An example of a reversible thermochromic composition to which such a microcapsule pigment can be applied is a composition described in Japanese Patent Publication Nos. 51-44706, 51-44707, and 1-29398, which changes color around a predetermined temperature (color change point), exhibiting a decolorized state in a temperature range above the high-temperature color change point and a colored state in a temperature range below the low-temperature color change point, with only one specific state existing at room temperature, and the other state being maintained while the heat or cold required to manifest that state is applied, but returning to the state it exhibits at room temperature when the heat or cold is removed; this composition has a relatively small hysteresis width (ΔH) (ΔH=1 to 7°C) (see Figure 1).

[0018] Other examples of reversible thermochromic compositions to which such microcapsule pigments can be applied include those described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, and JP-A-2005-1369, which exhibit a large hysteresis width (ΔH=8-70°C), and in which the shape of the curve plotting the change in color density with temperature follows a significantly different path when the temperature is increased from below the color-change temperature range than when the temperature is decreased from above the color-change temperature range, and which exhibit color memory in a specific temperature range (the temperature range between the color-development onset temperature t2 and the color-discoloration onset temperature t3 (a temperature range in which two phases are essentially maintained)) that exhibits a colored state at temperatures below the complete color-development temperature t1 or a color-discolored state at temperatures above the complete color-discoloration temperature t4 (see Figure 2).

[0019] [Microcapsule pigment] Components (a), (b) and (c) will be specifically explained below. Component (A), that is, the electron-donating color-forming organic compound, is the component that determines the color, and is a compound that donates electrons to component (B), which is the color developer, to develop color.

[0020] Examples of the electron-donating color-forming organic compound include phthalide compounds, fluoran compounds, styrinoquinoline compounds, diazarhodamine lactone compounds, pyridine compounds, quinazoline compounds, and bisquinazoline compounds, and among these, phthalide compounds and fluoran compounds are preferred. Examples of the phthalide compound include a diphenylmethane phthalide compound, a phenylindolyl phthalide compound, an indolyl phthalide compound, a diphenylmethane azaphthalide compound, a phenylindolyl azaphthalide compound, and derivatives thereof. Among these, the phenylindolyl azaphthalide compound and derivatives thereof are preferred. Examples of the fluoran compound include aminofluoran compounds, alkoxyfluoran compounds, and derivatives thereof.

[0021] Examples of compounds that can be used as component (a) are listed below. 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, 3,3-bis(1-n-butyl-2-methylindol-3-yl)phthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-n-hexyloxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-[2-ethoxy-4-(N-ethylanilino)phenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(2-acetamido-4-diethylaminophenyl)-3-(1-propyl-2-methylindol-3-yl)-4-azaphthalide, 3,6-bis(diphenylamino)fluoran, 3,6-bis(N-phenyl-Np-tolylamino)fluoran, 3,6-dimethoxyfluoran, 3,6-di-n-butoxyfluorane, 2-methyl-6-(N-ethyl-Np-tolylamino)fluoran, 3-chloro-6-cyclohexylaminofluoran, 2-methyl-6-cyclohexylaminofluoran, 2-chloroamino-6-di-n-butylaminofluoran, 2-(2-chloroanilino)-6-di-n-butylaminofluoran, 2-(3-trifluoromethylanilino)-6-diethylaminofluoran, 2-(3-trifluoromethylanilino)-6-di-n-pentylaminofluoran, 2-dibenzylamino-6-diethylaminofluoran, 2-(N-methylanilino)-6-(N-ethyl-Np-tolylamino)fluoran, 1,3-dimethyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methoxy-6-diethylaminofluoran, 2-anilino-3-methyl-6-di-n-butylaminofluoran, 2-anilino-3-methoxy-6-di-n-butylaminofluoran, 2-xylidino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-(N-ethyl-Np-tolylamino)fluoran, 6-diethylamino-1,2-benzofluoran, 6-(N-ethyl-N-isobutylamino)-1,2-benzofluoran, 6-(N-ethyl-N-isopentylamino)-1,2-benzofluoran, 2-(3-methoxy-4-dodecoxystyryl)quinoline, 2-diethylamino-8-diethylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 2-di-n-butylamino-8-di-n-butylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 2-di-n-butylamino-8-diethylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 2-di-n-butylamino-8-(N-ethyl-N-isoamylamino)-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 2-di-n-butylamino-8-di-n-pentylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 4,5,6,7-tetrachloro-3-(4-dimethylamino-2-methoxyphenyl)-3-(1-n-butyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 4,5,6,7-tetrachloro-3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 4,5,6,7-tetrachloro-3-(4-diethylamino-2-ethoxyphenyl)-3-(1-n-pentyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 4,5,6,7-tetrachloro-3-(4-diethylamino-2-methylphenyl)-3-(1-ethyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 3',6'-bis[phenyl(2-methylphenyl)amino]spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one, 3',6'-bis[phenyl(3-methylphenyl)amino]spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one, 3',6'-bis[phenyl(3-ethylphenyl)amino]spiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3-one, 2,6-bis(2′-ethyloxyphenyl)-4-(4′-dimethylaminophenyl)pyridine, 2,6-bis(2′,4′-diethyloxyphenyl)-4-(4′-dimethylaminophenyl)pyridine, 2-(4′-dimethylaminophenyl)-4-methoxyquinazoline, 4,4'-Ethylenedioxy-bis[2-(4-diethylaminophenyl)quinazoline]

[0022] In addition, fluorans may be compounds having a substituent on the phenyl group forming the xanthene ring, or may be compounds that have a substituent on the phenyl group forming the xanthene ring and also have a substituent (for example, an alkyl group such as a methyl group, or a halogen atom such as a chlorine atom) on the phenyl group forming the lactone ring, and that exhibit a blue or black color.

[0023] Component (b), ie, the electron accepting compound, is a compound that accepts electrons from component (a) and functions as a developer for component (a). Examples of the electron-accepting compound include compounds selected from the group of compounds having an active proton, the group of pseudo-acidic compounds (compounds that are not acids but act as acids in the reversible thermochromic composition to cause component (A) to develop color), and the group of compounds having an electron vacancy. Among the above-mentioned component (B), compounds selected from the group of compounds having an active proton are preferred.

[0024] Examples of compounds having an active proton include compounds having a phenolic hydroxyl group and derivatives thereof, carboxylic acids and derivatives thereof, acidic phosphate esters and derivatives thereof, azole compounds and derivatives thereof, 1,2,3-triazole and derivatives thereof, cyclic carbosulfimides, halohydrins having 2 to 5 carbon atoms, sulfonic acids and derivatives thereof, and inorganic acids. Preferred examples of carboxylic acids and derivatives thereof include aromatic carboxylic acids and derivatives thereof, and aliphatic carboxylic acids having 2 to 5 carbon atoms and derivatives thereof. Examples of the pseudo-acidic compounds include metal salts of compounds having a phenolic hydroxyl group, metal salts of carboxylic acids, metal salts of acidic phosphate esters, metal salts of sulfonic acids, aromatic carboxylic acid anhydrides, aliphatic carboxylic acid anhydrides, mixed anhydrides of aromatic carboxylic acids and sulfonic acids, cycloolefin dicarboxylic acid anhydrides, urea and its derivatives, thiourea and its derivatives, guanidine and its derivatives, and halogenated alcohols. Compounds having electron vacancies include borates, borate esters, and inorganic salts.

[0025] Among the above-mentioned components (ii), compounds having a phenolic hydroxyl group are preferred because they can more effectively exhibit thermochromic properties. Compounds having a phenolic hydroxyl group include a wide range of compounds, from monophenol compounds to polyphenol compounds, and further include bisphenol compounds, trisphenol compounds, phenol-aldehyde condensation resins, etc. Compounds having a phenolic hydroxyl group preferably have at least two benzene rings. In addition, compounds having a phenolic hydroxyl group may have a substituent such as an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carboxyl group and its ester or amide group, or a halogen atom.

[0026] Examples of metals contained in metal salts of compounds having a phenolic hydroxyl group include sodium, potassium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, and molybdenum.

[0027] Examples of compounds of component (b) are given below. Examples of compounds having one phenolic hydroxyl group include: phenol, o-cresol, m-cresol, p-cresol, 4-ethylphenol, 4-n-propylphenol, 4-n-butylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, 4-n-pentylphenol, 4-tert-pentylphenol, 4-n-octylphenol, 4-tert-octylphenol, 4-n-nonylphenol, 4-n-dodecylphenol, 3-n-pentadecylphenol, 4-n-stearylphenol, 1-(4-hydroxyphenyl)decan-1-one, 4-chlorophenol, 4-bromophenol, 4-trifluoromethylphenol, 4-methylthiophenol, 4-nitrophenol, 2-phenylphenol, 4-phenylphenol, 2-benzylphenol, 2-benzyl-4-chlorophenol, 4-cumylphenol, 4-hydroxybenzophenone, 4-chloro-4′-hydroxybenzophenone, 4-fluoro-4′-hydroxybenzophenone, 4-cyclohexylphenol, 2-hydroxybenzyl alcohol, 3-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, 4-(2-hydroxyethyl)phenol, 3-methoxyphenol, 4-ethoxyphenol, 4-n-propoxyphenol, 4-n-butoxyphenol, 4-n-heptyloxyphenol, 4-(2-methoxyethyl)phenol, α-naphthol, β-naphthol, 2,3-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,6-di-tert-butylphenol, 2,4-dichlorophenol, 2,4-difluorophenol, thymol, 3-methyl-4-methylthiophenol, 2-tert-butyl-5-methylphenol, 2,6-bis(hydroxymethyl)-4-methylphenol, 2,3,5-trimethylphenol, 2,6-bis(hydroxymethyl)-4-tert-octylphenol, 6-hydroxy-1,3-benzoxathiol-2-one, 2,4-bis(phenylsulfonyl)phenol, 2,4-bis(phenylsulfonyl)-5-methylphenol, 2,4-bis(4-methylphenylsulfonyl)phenol, 2-phenylphenol, 4-phenylphenol, 2,6-diphenylphenol, 3-benzylbiphenyl-2-ol, 3,5-dibenzylbiphenyl-4-ol, 4-cyano-4′-hydroxybiphenyl, 1-hydroxybenzotriazole, 1-hydroxy-5-methylbenzotriazole, 1-hydroxy-5-chlorobenzotriazole, 1-hydroxy-5-methoxybenzotriazole, 1-hydroxy-4-benzoylaminobenzotriazole, 1-hydroxy-4,5,6,7-tetrachlorobenzotriazole, 1,4-hydroxybenzotriazole, 1-hydroxy-5-nitrobenzotriazole, 1-hydroxy-5-phenylbenzotriazole, 1-hydroxy-5-benzylbenzotriazole, 1-hydroxy-5-ethylbenzotriazole, 1-hydroxy-5-n-octylbenzotriazole, 1-hydroxy-5-n-butylbenzotriazole, n-Butyl 4-hydroxybenzoate, n-Octyl 4-hydroxybenzoate, 4-Hydroxybenzoic acid 2-heptadecafluorooctylethane, benzyl 4-hydroxybenzoate, 4-hydroxybenzoic acid benzyl ester, o-methylbenzyl 4-hydroxybenzoate, m-methylbenzyl 4-hydroxybenzoate, p-methylbenzyl 4-hydroxybenzoate, p-ethylbenzyl 4-hydroxybenzoate, p-propylbenzyl 4-hydroxybenzoate, p-tert-butylbenzyl 4-hydroxybenzoate, phenylethyl 4-hydroxybenzoate, 4-hydroxybenzoic acid-o-methylphenylethyl ester, m-Methylphenylethyl 4-hydroxybenzoate, p-methylphenylethyl 4-hydroxybenzoate, p-Ethylphenylethyl 4-hydroxybenzoate, p-propylphenylethyl 4-hydroxybenzoate, p-tert-butylphenylethyl 4-hydroxybenzoate Examples include:

[0028] Examples of compounds having two phenolic hydroxyl groups include: Resorcinol, 2-methylresorcinol, 4-n-hexylresorcinol, 4-n-octylresorcinol, 4-tert-octylresorcinol, 4-benzoylresorcinol, 4-nitroresorcinol, β-methyl resorcylate, β-benzyl resorcylate, 2-chloro-4-pentanoylresorcinol, 6-chloro-4-pentanoylresorcinol, 2-chloro-4-hexanoylresorcinol, 6-chloro-4-hexanoylresorcinol, 2-chloro-4-propanoylresorcinol, 6-chloro-4-propanoylresorcinol, 2,6-dichloro-4-propanoylresorcinol, 6-fluoro-4-propanoylresorcinol, 2-chloro-4-phenylacetylresorcinol, 6-chloro-4-phenylacetylresorcinol, 2-chloro-4-β-phenylpropanoylresorcinol, 6-chloro-4-β-phenylpropanoylresorcinol, 2-chloro-4-phenoxyacetylresorcinol, 6-chloro-4-phenoxyacetylresorcinol, 4-benzoyl-2-chlororesorcinol, 6-chloro-4-m-methylbenzoylresorcinol, 4-[1',3',4',9'a-tetrahydro-6'-hydroxyspiro(cyclohexane-1,9'-[9H]-xanthene)-4'a-[2H]-yl]-1,3-benzenediol, hydroquinone, methylhydroquinone, trimethylhydroquinone, Catechol, 4-tert-butylcatechol, 1,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,4-dihydroxybenzophenone, 4,4′-dihydroxybenzophenone, 2,4-dihydroxy-2′-methylbenzophenone, 2,4-dihydroxy-3′-methylbenzophenone, 2,4-dihydroxy-4′-methylbenzophenone, 2,4-dihydroxy-4′-ethylbenzophenone, 2,4-dihydroxy-4′-n-propylbenzophenone, 2,4-dihydroxy-4′-isopropylbenzophenone, 2,4-dihydroxy-4′-n-butylbenzophenone, 2,4-dihydroxy-4′-isobutylbenzophenone, 2,4-dihydroxy-4′-tert-butylbenzophenone, 2,4-dihydroxy-4′-n-pentylbenzophenone, 2,4-dihydroxy-4′-n-hexylbenzophenone, 2,4-dihydroxy-4′-n-heptylbenzophenone, 2,4-dihydroxy-4′-n-octylbenzophenone, 2,4-dihydroxy-4′-n-decylbenzophenone, 2,4-dihydroxy-2′,3′-dimethylbenzophenone, 2,4-dihydroxy-2′,4′-dimethylbenzophenone, 2,4-dihydroxy-2′,5′-dimethylbenzophenone, 2,4-dihydroxy-2′,6′-dimethylbenzophenone, 2,4-dihydroxy-3′,4′-dimethylbenzophenone, 2,4-dihydroxy-3′,5′-dimethylbenzophenone, 2,4-dihydroxy-2′,4′,6′-trimethylbenzophenone, 2,4-dihydroxy-2′-methoxybenzophenone, 2,4-dihydroxy-3′-methoxybenzophenone, 2,4-dihydroxy-4′-methoxybenzophenone, 2,4-dihydroxy-2′-ethoxybenzophenone, 2,4-dihydroxy-4′-ethoxybenzophenone, 2,4-dihydroxy-4′-n-propoxybenzophenone, 2,4-dihydroxy-4′-isopropoxybenzophenone, 2,4-dihydroxy-4′-n-butoxybenzophenone, 2,4-dihydroxy-4′-isobutoxybenzophenone, 2,4-dihydroxy-4′-n-pentyloxybenzophenone, 2,4-dihydroxy-4′-n-hexyloxybenzophenone, 2,4-dihydroxy-4′-n-heptyloxybenzophenone, 2,4-dihydroxy-4′-n-octyloxybenzophenone, 2,4-dihydroxy-4′-n-nonyloxybenzophenone, 2,4-dihydroxy-2′,3′-dimethoxybenzophenone, 2,4-dihydroxy-2′,4′-dimethoxybenzophenone, 2,4-dihydroxy-2′,5′-dimethoxybenzophenone, 2,4-dihydroxy-2′,6′-dimethoxybenzophenone, 2,4-dihydroxy-3′,4′-dimethoxybenzophenone, 2,4-dihydroxy-3′,5′-dimethoxybenzophenone, 2,4-dihydroxy-3′,4′-diethoxybenzophenone, 2,4-dihydroxy-2′,3′,4′-trimethoxybenzophenone, 2,4-dihydroxy-2′,3′,6′-trimethoxybenzophenone, 2,4-dihydroxy-3′,4′,5′-trimethoxybenzophenone, 2,4-Dihydroxy-3',4',5'-triethoxybenzophenone Examples include:

[0029] Further, examples of bisphenol compounds include: 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl) n-butane, 1,1-bis(4-hydroxyphenyl) n-pentane, 1,1-bis(4-hydroxyphenyl) n-hexane, 1,1-bis(4-hydroxyphenyl) n-heptane, 1,1-bis(4-hydroxyphenyl) n-octane, 1,1-bis(4-hydroxyphenyl)n-nonane, 1,1-bis(4-hydroxyphenyl) n-decane, 1,1-bis(4-hydroxy-3-methylphenyl)decane, 1,1-bis(4-hydroxyphenyl) n-dodecane, 1,1-bis(4-hydroxyphenyl)-2-methylpropane, 1,1-bis(4-hydroxyphenyl)-3-methylbutane, 1,1-bis(4-hydroxyphenyl)-3-methylpentane, 1,1-bis(4-hydroxyphenyl)-2,3-dimethylpentane, 1,1-bis(4-hydroxyphenyl)-2-ethylbutane, 1,1-bis(4-hydroxyphenyl)-2-ethylhexane, 1,1-bis(4-hydroxyphenyl)-3,7-dimethyloctane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4-hydroxy-3-methyl)cyclohexane, diphenolic acid, 1-phenyl-1,1-bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl) n-butane, 2,2-bis(4-hydroxyphenyl) n-pentane, 2,2-bis(4-hydroxyphenyl) n-hexane, 2,2-bis(4-hydroxyphenyl) n-heptane, 2,2-bis(4-hydroxyphenyl) n-octane, 2,2-bis(4-hydroxyphenyl)n-nonane, 2,2-bis(4-hydroxyphenyl) n-decane, 2,2-bis(4-hydroxyphenyl) n-dodecane, 2,2-bis(4-hydroxyphenyl)-6,10,14-trimethylpentadecane, 1-phenyl-1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)methylpropionate, 2,2-bis(4-hydroxyphenyl)butylpropionate, 2,2-bis(4-hydroxy-3-methylphenyl)methylpropionate, 2,2-bis(4-hydroxyphenyl)ethyl propionate, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 2,2-bis(4-hydroxyphenyl)-4-methylhexane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)butane, 2,2-bis(4-hydroxy-3-isopropylphenyl)propane, 2,2-bis(3-sec-butylphenyl-4-hydroxy)propane, 2,2-bis(4-hydroxy-3-phenylphenyl)propane, 2,2-bis(3-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-fluoro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dihydroxymethyl-4-hydroxyphenyl)propane, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 3,3-bis(4-hydroxyphenyl)oxindole, 3,3-bis(4-hydroxy-3-methylphenyl)oxindole, bis(2-hydroxyphenyl)methane, bis(2-hydroxy-5-methylphenyl)methane, bis(2-hydroxy-3-hydroxymethyl-5-methyl)methane, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bis(2-methylphenol), 1,1-bis(4-hydroxy-3-phenylphenyl)cyclohexane, 3,3-ethyleneoxydiphenol, 1,4-bis(4-hydroxybenzoate)-3-methylbenzene, 4,4"-dihydroxy-3"-methyl-p-terphenyl, 4,4″-dihydroxy-3″-isopropyl-p-terphenyl, 2,2-dimethyl-1,3-bis(4-hydroxybenzoyloxy)propane, 2,2′-biphenol, 4,4′″-dihydroxy-p-quaterphenyl, 4,4-dihydroxydiphenyl ether, Bis(4-hydroxyphenylthioethyl) ether bis(4-hydroxyphenyl) sulfone, 4-benzyloxy-4′-hydroxydiphenyl sulfone, 4-(4-methylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-ethylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-n-propylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-isopropylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-n-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-isobutylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-sec-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(4-tert-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-methylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-ethylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-n-propylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-isopropylbenzyloxy)-4′-dihydroxyphenyl sulfone, 4-(3-n-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-isobutylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-sec-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(3-tert-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-methylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-ethylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-n-propylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-isopropylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-n-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-isobutylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-sec-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-tert-butylbenzyloxy)-4′-hydroxydiphenyl sulfone, 2,4′-dihydroxydiphenyl sulfone, 3,4′-dihydroxydiphenyl sulfone, 4-hydroxydiphenyl sulfone, 4-methyl-4'-hydroxyphenyl sulfone, 4-ethyl-4′-hydroxydiphenyl sulfone, 4-n-propyl-4′-hydroxydiphenyl sulfone, 4-isopropyl-4′-hydroxydiphenyl sulfone, 4-chloro-4′-hydroxydiphenyl sulfone, 4-fluoro-4′-hydroxydiphenyl sulfone, 4-chloro-2-methyl-4′-hydroxydiphenyl sulfone, 4-methoxy-4′-hydroxydiphenyl sulfone, 4-ethoxy-4′-hydroxydiphenyl sulfone, 4-n-propoxy-4′-hydroxydiphenyl sulfone, 4-isopropoxy-4′-hydroxydiphenyl sulfone, 4-n-butoxy-4′-hydroxydiphenyl sulfone, 4-isobutoxy-4′-hydroxydiphenyl sulfone, 4-sec-butoxy-4′-hydroxydiphenyl sulfone, 4-tert-butoxy-4′-hydroxydiphenyl sulfone, 4-n-pentyloxy-4′-hydroxydiphenyl sulfone, 4-isopentyloxy-4′-hydroxydiphenyl sulfone, 4-(1-propenyloxy)-4′-hydroxydiphenyl sulfone, 4-(2-propenyloxy)-4′-hydroxydiphenyl sulfone, 4-benzyloxy-4′-hydroxydiphenyl sulfone, 4-(β-phenoxyethoxy)-4′-hydroxydiphenyl sulfone, 4-(β-phenoxypropoxyl)-4′-hydroxydiphenyl sulfone, bis(2-allyl-4-hydroxydiphenyl) sulfone, bis[4-hydroxy-3-(2-propenyl)phenyl]sulfone, bis(3,5-dibromo-4-hydroxyphenyl) sulfone, bis(3,5-dichloro-4-hydroxyphenyl) sulfone, bis(3-phenyl-4-hydroxyphenyl) sulfone, bis(4-hydroxy-3-n-propylphenyl) sulfone, bis(4-hydroxy-3-methylphenyl) sulfone, 3,4-dihydroxydiphenyl sulfone, 3',4'-dihydroxy-4-methyldiphenyl sulfone, 3,4,4′-trihydroxydiphenyl sulfone, bis(3,4-dihydroxyphenyl) sulfone, 2,3,4-trihydroxydiphenyl sulfone, 4-isopropoxy-4′-hydroxydiphenyl sulfone, 4-n-propoxy-4′-hydroxydiphenyl sulfone, 4-allyloxy-4′-hydroxydiphenyl sulfone, 4-benzyloxy-4′-hydroxydiphenyl sulfone, 4-(2-propenyloxy)-4′-hydroxydiphenyl sulfone, 3-benzyl-4-benzyloxy-4′-hydroxydiphenyl sulfone, 3-phenethyl-4-phenethyloxy-4′-hydroxydiphenyl sulfone, 3-methylbenzyl-4-methylbenzyloxy-4′-hydroxydiphenyl sulfone, 4-benzyloxy-3′-benzyl-4′-hydroxydiphenyl sulfone, 4-phenethyloxy-3′-phenethyl-4′-hydroxydiphenyl sulfone, 4-methylbenzyloxy-3′-methylbenzyl-4′-hydroxydiphenyl sulfone, α,α′-bis{4-(p-hydroxyphenylsulfone)phenoxy}-p-xylene, 4,4′-{oxybis(ethylene oxide-p-phenylene sulfonyl)}diphenol, Bis(4-hydroxyphenyl) sulfide, bis(4-hydroxy-3-methylphenyl) sulfide, bis(3,5-dimethyl-4-hydroxyphenyl) sulfide, bis(3-ethyl-4-hydroxyphenyl) sulfide, bis(3,5-diethyl-4-hydroxyphenyl) sulfide, bis(4-hydroxy-3-n-propylphenyl) sulfide, bis(3,5-di-n-propyl-4-hydroxyphenyl) sulfide, bis(3-tert-butyl-4-hydroxyphenyl) sulfide, bis(3,5-di-tert-butyl-4-hydroxyphenyl) sulfide, bis(4-hydroxy-3-n-pentylphenyl) sulfide, bis(3-n-hexyl-4-hydroxyphenyl) sulfide, bis(3-n-heptyl-4-hydroxyphenyl) sulfide, bis(5-tert-octyl-2-hydroxyphenyl) sulfide, bis(2-hydroxy-3-tert-octylphenyl) sulfide, bis(2-hydroxy-5-n-octyl-phenyl) sulfide, bis(5-chloro-2-hydroxyphenyl) sulfide, bis(3-cyclohexyl-4-hydroxyphenyl) sulfide, bis(4-hydroxyphenylthioethoxy)methane, 1,5-(4-hydroxyphenylthio)-3-oxypentane, 1,8-bis(4-hydroxyphenylthio)-3,6-dioxaoctane Examples include:

[0030] Examples of compounds having three phenolic hydroxyl groups include pyrogallol, phloroglucinol, phloroglucinolcarboxylic acid, gallic acid, octyl gallate, and dodecyl gallate.

[0031] Further examples of trisphenol compounds include: 4,4′,4″-methylidynetrisphenol, 4,4′,4″-methylidynetris(2-methylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2,3,5-trimethylphenol), 4,4'-[(4-hydroxyphenyl)methylene]bis(2-methylphenol), 4,4'-[(4-hydroxyphenyl)methylene]bis(2,6-dimethylphenol), 4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bisphenol, 4,4'-[(4-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 4,4′,4″-ethylidynetrisphenol, 4,4′,4″-ethylidinetris(2-methylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenol, 2,4-bis[(2-hydroxy-5-methylphenyl)methyl]-6-cyclohexylphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}methylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}propylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}butylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}pentylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}hexylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}heptylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}isobutylidene]bisphenol, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}neopentylidene]bisphenol, 2,2'-[1-{4-[1-(2-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol, 3,3′-[1-{4-[1-(3-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol, 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-fluorophenol), 4,4'-[1-{4-[1-(3-chloro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-chlorophenol), 4,4'-[1-{4-[1-(3-bromo-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-bromophenol), 4,4'-[1-{4-[1-(4-hydroxy-3-methylphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-methylphenol), 4,4'-[1-{4-[1-(3-ethyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-ethylphenol), 4,4'-[1-{4-[1-(3-tert-butyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-tert-butylphenol), 4,4'-[1-{4-[1-(4-hydroxy-3-trifluoromethylphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-trifluoromethylphenol), 1,1-bis(4-hydroxyphenyl)-4-(4-hydroxy-α-ethyl)benzylcyclohexane, 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bisphenol, 4,4'-[(3-hydroxyphenyl)methylene]bis(2,6-dimethylphenol), 2,2'-[(4-hydroxyphenyl)methylene]bis(3,5-dimethylphenol), 4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2,6-dimethylphenol), 2,2'-[(2-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 4,4'-[(3-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol), 4,4'-[(4-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol), 4,4'-[(3-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[(4-hydroxyphenyl-3-methoxy)methylene]bis(2-cyclohexyl-5-methylphenol), 1,1-bis(4-hydroxyphenyl)-4-hydroxyphenylcyclohexane, 4,4'-[3-(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-phenyl)propylidene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2-methylphenol), 2,4′,4″-methylidynetrisphenol, 4,4'-[(2-hydroxyphenyl)methylene]bis(3-methylphenol), 4,4'-[4-(4-hydroxyphenyl)-sec-butylidene]bis(4-hydroxyphenol), 2,2'-[(3-hydroxyphenyl)methylene]bis(3,5-dimethylphenol), 4,4'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2,5-dimethylphenol), 4,4'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2,6-dimethylphenol), 2,2'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(3,5-dimethylphenol), 2,2'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(3,5-dimethylphenol), 2,2'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(3,5-dimethylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2-isopropylphenol), 4,4'-[(3-hydroxyphenyl)methylene]bis(2-isopropylphenol), 4,4'-[(4-hydroxyphenyl)methylene]bis(2-isopropylphenol), 2,2'-[(3-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 2,2'-[(4-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 2,2'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(3,5-dimethylphenol), 1,1-bis(4-hydroxy-3-methylphenyl)-4-(4-hydroxyphenyl)cyclohexane, 4,4'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(2-isopropylphenol), 4,4'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(2-isopropylphenol), 4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2-isopropylphenol), 2,2'-[(2-hydroxy-3-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol), 2,2'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol), 2,2'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(3,5,6-trimethylphenol), 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-isopropylphenol), 2,2'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2,3,6-trimethylphenol), 1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)cyclohexane, 4,4'-[(4-hydroxy-3-methoxyphenyl)methylene]bis(2-tert-butyl-5-methylphenol), 4,4'-[(2-hydroxyphenyl)methylene]bis(2-cyclohexylphenol), 4,4'-[(3-hydroxyphenyl)methylene]bis(2-cyclohexylphenol), 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-tert-butyl-6-methylphenol), 4,4'-[(3-methoxy-2-hydroxyphenyl)methylene]bis(2-cyclohexylphenol), 4,4'-[(3-hydroxy-4-methoxyphenyl)methylene]bis(2-cyclohexylphenol), 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-tert-butylphenol), 4,4'-[1-{4-[1-(3,5-dimethyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2,6-dimethylphenol), 4,4'-[(3-ethoxy-4-hydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[(3-cyclohexyl-4-hydroxyphenyl)ethylidene]bis(2-cyclohexylphenol), 4,4'-[(5-cyclohexyl-4-hydroxy-2-methoxyphenyl)ethylidene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[1-{4-[1-(3-cyclohexyl-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-cyclohexylphenol), 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol, 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2-methylphenol), 4,4'-[1-{4-[1-(3-fluoro-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis(2,6-dimethylphenol), 2,6-bis[(5-fluoro-2-hydroxyphenyl)methyl]-4-methylphenol, 2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-4-methylphenol, 2,6-bis[(4-hydroxyphenyl)methyl]-4-methylphenol, 2,6-bis[(4-hydroxyphenyl)methyl]-4-ethylphenol, 2,4-bis[(4-hydroxy-3-methylphenyl)methyl]-6-methylphenol, 2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-methylphenol, 2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-ethylphenol, 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-ethylphenol, 2,6-bis[(3,5-dimethyl-2-hydroxyphenyl)methyl]-4-methylphenol, 2,6-bis[(2,4-dimethyl-6-hydroxyphenyl)methyl]-4-methylphenol, 2,4-bis[(4-hydroxyphenyl)methyl]-6-cyclohexylphenol, 2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-3,4-dimethylphenol, 2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-4-ethylphenol, 2,6-bis[(4-hydroxy-2,3,6-trimethylphenyl)methyl]-4-methylphenol, 2,4-bis[(4-hydroxy-3-methylphenyl)methyl]-6-cyclohexylphenol, 2,6-bis[(4-hydroxy-3-methylphenyl)methyl]-4-cyclohexylphenol, 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-cyclohexylphenol, 2,6-bis[(4-hydroxy-2,3,5-trimethylphenyl)methyl]-4-ethylphenol, 2,4-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-6-cyclohexylphenol, 4,4′,4″-methylidynetris(2,6-dimethylphenol), α-(4-hydroxy-3-methylphenyl)-α,α′-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, α′-(4-hydroxy-3-methylphenyl)-α,α-bis(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, α,α-bis(4-hydroxy-3-methylphenyl)-α′-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, α,α′-bis(4-hydroxy-3-methylphenyl)-α-(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, 1,1-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)-1-methylpropyl]cyclohexane, 2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-4-ethylphenol, 1,1′-bis(4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane, 1,1′-bis(4-hydroxy-3-methylphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane, 1,1′-bis(3,5-dimethyl-4-hydroxyphenyl)-4-[1-(4-hydroxyphenyl)propyl]cyclohexane, 1-(4-hydroxyphenyl)-1-[4,4-bis(4-hydroxyphenyl)cyclohexyl]-4-isopropylcyclohexane, 4,4'-[3-(2,5-dimethyl-4-hydroxyphenyl)butylene]bis(2,5-dimethylphenol), 1,3,5-tri(4-hydroxy-3-phenylphenyl)adamantane, 1,3,5-tri(3-cyclohexyl-4-hydroxyphenyl)adamantane, 2,4-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-6-cyclohexylphenol, 2,6-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-4-cyclohexylphenol, 2,4-bis[(3-cyclohexyl-4-hydroxyphenyl)methyl]-6-methylphenol, 2,4-bis[(4-hydroxy-2,3,5-trimethylphenyl)methyl]-6-cyclohexylphenol, 2,6-bis[(5-fluoro-2-hydroxyphenyl)methyl]-4-fluorophenol, 2,6-bis[(3-fluoro-4-hydroxyphenyl)methyl]-4-fluorophenol, 2,4-bis[(3-fluoro-4-hydroxyphenyl)methyl]-6-methylphenol, 4,4'-[3-(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-biphenylpropylidene]bis(5-cyclohexyl-2-methylphenol), 4,4'-[3-(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropylidene]bis(2,5-dimethylphenol), 2,4-bis[(2,5-dimethyl-4-hydroxyphenyl)methyl]-6-methylphenol, 1,1,2-tris(4-hydroxyphenyl)ethane, 1,1,3-tris(4-hydroxyphenyl)propane, 1,1,4-tris(4-hydroxyphenyl)butane, 1,2,2-tris(4-hydroxyphenyl)propane, 1,2,2-tris(4-hydroxyphenyl)butane, 1,2,2-tris(4-hydroxyphenyl)pentane, 1,2,2-tris(4-hydroxyphenyl)hexane, 1,2,2-tris(4-hydroxyphenyl)heptane, 1,2,2-tris(4-hydroxyphenyl)octane, 1,2,2-tris(4-hydroxyphenyl)-3-methylbutane 1,2,2-tris(4-hydroxyphenyl)-3,3-dimethylbutane, 1,2,2-tris(4-hydroxyphenyl)-4,4-dimethylpentane, 1,3,3-tris(4-hydroxyphenyl)butane, 1,3,3-tris(4-hydroxyphenyl)pentane, 1,3,3-tris(4-hydroxyphenyl)hexane, 1,3,3-tris(4-hydroxyphenyl)heptane, 1,3,3-tris(4-hydroxyphenyl)octane, 1,3,3-tris(4-hydroxyphenyl)nonane, 1,4,4-tris(4-hydroxyphenyl)pentane, 1,4,4-tris(4-hydroxyphenyl)hexane, 1,4,4-tris(4-hydroxyphenyl)heptane, 1,4,4-tris(4-hydroxyphenyl)octane, 1,4,4-tris(4-hydroxyphenyl)nonane, 1,4,4-tris(4-hydroxyphenyl)decane, 1,2,2-tris(2-hydroxyphenyl)propane, 1,1,2-tris(3-hydroxyphenyl)propane, 1-(4-hydroxyphenyl)-2,2-bis(2-hydroxyphenyl)propane, 1,2,2-tris(3-fluoro-4-hydroxyphenyl)propane, 1,2,2-tris(3-chloro-4-hydroxyphenyl)propane, 1,2,2-tris(3-bromo-4-hydroxyphenyl)propane, 2,2-bis(3-ethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane, 2,2-bis(3-tert-butyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane, 2,2-bis(2-hydroxy-3-biphenylyl)-1-(4-hydroxyphenyl)propane, 2,2-bis(3-trifluoromethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)propane, 2-(3-methyl-4-hydroxyphenyl)-1,2-bis(4-hydroxyphenyl)propane, 1-(3-methyl-4-hydroxyphenyl)-2,2-bis(4-hydroxyphenyl)propane, 3-(3-methyl-4-hydroxyphenyl)-1,3-bis(4-hydroxyphenyl)butane, 1-(3-methyl-4-hydroxyphenyl)-3,3-bis(4-hydroxyphenyl)butane, 4-(3-methyl-4-hydroxyphenyl)-1,4-bis(4-hydroxyphenyl)pentane, 1-(3-methyl-4-hydroxyphenyl)-4,4-bis(4-hydroxyphenyl)pentane, 1,2-bis(3-methyl-4-hydroxyphenyl)-2-(4-hydroxyphenyl)propane, 3,3-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)butane, 1,3-bis(3-methyl-4-hydroxyphenyl)-3-(4-hydroxyphenyl)butane, 4,4-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)pentane, 1,4-bis(3-methyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)pentane, 1,1,2-tris(3-methyl-4-hydroxyphenyl)ethane, 1,2,2-tris(3-methyl-4-hydroxyphenyl)propane, 1,1,3-tris(3-methyl-4-hydroxyphenyl)propane, 1,3,3-tris(3-methyl-4-hydroxyphenyl)butane, 1,1,4-tris(3-methyl-4-hydroxyphenyl)butane, 1,4,4-tris(3-methyl-4-hydroxyphenyl)pentane, 4,4'-[4-(4-hydroxyphenyl)-sec-butylidene]bis(2-methylphenol) Examples include:

[0032] Examples of compounds having four or more phenolic hydroxyl groups include: Bis[2-hydroxy-3-(2-hydroxy-5-methylbenzyl)-5-methylphenyl]methane, 4,6-bis[(4-hydroxyphenyl)methyl]-1,3-benzenediol, 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2,6-dimethylphenol), 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexyl-5-methylphenol), 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-methylphenol), 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2,3,6-trimethylphenol), 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 4,4′,4″,4′″-(1,1,2,2-ethanetetrayl)tetrakis(2-methylphenol), 4,4′,4″,4′″-(1,1,2,2-ethanetetrayl)tetrakis(2,6-dimethylphenol), 4,4',4"4'"-(1,4-phenylene)bis(methylidyne)tetrakis(2,6-dimethylphenol), 2,2-bis[4,4-bis(4-hydroxy-3-methylphenyl)cyclohexyl]propane, 2,2'-[(3,4-dihydroxyphenyl)methylene]bis(3,5-dimethylphenol), 4,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-1,3-benzenediol, 2,2'-[(3,4-dihydroxyphenyl)methylene]bis(3,5,6-trimethylphenol), 4,4'-[(3,4-dihydroxyphenyl)methylene]bis(2-cyclohexylphenol), Bis[4-hydroxy-3-(2-hydroxybenzyl)-5-methylphenyl]methane, Bis[4-hydroxy-3-(3-hydroxybenzyl)-5-methylphenyl]methane, bis[4-hydroxy-3-(4-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(3-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(4-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(3-hydroxy-4-methylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(4-hydroxy-3-methylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(3-hydroxy-2-methylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2-hydroxy-3-methylbenzyl)-5-methylphenyl]methane, α,α′,α″,α′″-tetrakis(4-hydroxyphenyl)-p-xylene, Bis[2-hydroxy-3-(4-hydroxy-2,3,5-trimethylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2,5-dimethyl-3-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2,5-dimethyl-4-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2,5-dimethyl-5-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(3,5-dimethyl-4-hydroxybenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(2-hydroxy-3,4,6-trimethylbenzyl)-5-methylphenyl]methane, Bis[2-hydroxy-3-(4-hydroxy-2,3,6-trimethylbenzyl)-5-methylphenyl]methane, 4,4,4′,4′-tetrakis(4-hydroxyphenyl)bicyclohexyl, Bis[4-hydroxy-3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)-5-methylphenyl]methane, 4,4,4′,4′-tetrakis(4-hydroxy-3-methylphenyl)bicyclohexyl, 4,6-bis(3,5-dimethyl-4-hydroxyphenyl)-1,2-benzenediol, 4,4,4′,4′-tetrakis(3,5-dimethyl-4-hydroxyphenyl)bicyclohexyl, 1,1-bis[5-cyclohexyl-4-hydroxy-3-(2-hydroxy-5-methylbenzyl)phenyl]cyclohexane, 1,1-bis[5-cyclohexyl-4-hydroxy-3-(3,5-dimethyl-4-hydroxybenzyl)phenyl]cyclohexane, 1,1-bis[5-cyclohexyl-4-hydroxy-3-(5-cyclohexyl-4-hydroxy-2-methylbenzyl)phenyl]cyclohexane, 4,6-bis[1-(4-hydroxyphenyl)ethyl]-1,3-benzenediol, 2,2-bis[4-hydroxy-3-(4-hydroxy-3-methylbenzyl)-5-methylphenyl]propane, 2,6-bis[(3,5-dimethyl-4-hydroxyphenyl)benzyl]-4-[α-methyl-(3,5-dimethyl-4-hydroxyphenyl)benzyl]phenol, 4,4,4′,4′-tetrakis(3-isopropyl-4-hydroxyphenyl)bicyclohexyl, 4,4'-bis[(3,4-dihydroxyphenyl)methylene]bis(2-isopropylphenol), 2,2'-bis[4,4-bis(4-hydroxyphenyl)cyclohexyl]propane, 2,4,6-tris(4-hydroxybenzyl)-1,3-benzenediol, 4,6-bis(3,5-dimethyl-4-hydroxybenzyl)-1,2,3-benzenetriol, 3,3'-[(2-hydroxyphenyl)methylene]bis(5-methyl-1,2-benzenediol), 2,6-bis(2,4-dihydroxybenzyl)-4-ethylphenol, 2,4-bis(2,4-dihydroxybenzyl)-6-cyclohexylphenol, 2,6-bis(5-tert-butyl-2,3-dihydroxybenzyl)-4-methylphenol, 2,4,6-tris(3,5-dimethyl-4-hydroxybenzyl)-1,2-benzenediol, 2,4,6-tris(3,5-dimethyl-2-hydroxybenzyl)-1,2-benzenediol, 2,6-bis(2,4-dihydroxybenzyl)-3,4-dimethylphenol, 2,6-bis[3-(2-hydroxy-5-methylbenzyl)-2,5-dimethyl-4-hydroxybenzyl]-3,4-dimethylphenol, 4,6-bis(α-methyl-4-hydroxybenzyl)-1,2,3-benzenetriol, 4,4'-[1-{4-[1-(3,5-bis(4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxybenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-3-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-3-methylbenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3,5-dimethyl-4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3,5-dimethyl-4-hydroxybenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2,3,6-trimethylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-2,3,6-trimethylbenzyl)phenol], Bis[5-(2,4-dihydroxybenzyl)-4-hydroxy-3-methylphenyl]methane, Bis[3-(2,4-dihydroxybenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane, Bis[3-(2,4-dihydroxy-3-methylbenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane, Bis[5-(4-hydroxybenzyl)-2,3,4-trihydroxyphenyl]methane, 1,1-bis[5-(4-hydroxybenzoyl)-2,3,4-trihydroxyphenyl]ethane, 3,3′,5,5′-tetrakis(4-hydroxybenzyl)-4,4′-dihydroxybiphenyl, 3,3′,5,5′-tetrakis(4-hydroxy-3-methylbenzyl)-4,4′-dihydroxybiphenyl, 3,3′,5,5′-tetrakis(2-hydroxy-5-methylbenzyl)-4,4′-dihydroxybiphenyl, 3,3′,5,5′-tetrakis(3,5-dimethyl-4-hydroxybenzyl)-4,4′-dihydroxybiphenyl, Bis[3-(α,α-bis(4-hydroxy-3-methylphenyl)methyl-4-hydroxyphenyl]methane, Bis[3,5-bis(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane, 4,4',4"-ethylidinetris{[2-(2-hydroxy-5-methyl)benzyl]-6-methylphenol}, 2,2-bis[3,5-bis(2-hydroxy-5-methylphenylmethyl)phenyl]propane, Bis[3-(α,α-bis(2,5-dimethyl-4-hydroxyphenyl)methyl-4-hydroxyphenyl]methane, Bis[5-(3,5-dimethyl-4-hydroxybenzyl)-2,3,4-trihydroxyphenyl]methane, Bis[3-(2,3,4-trihydroxybenzyl)-2,5-dimethyl-4-hydroxyphenyl]methane, 1,1-bis[3-(2,3,4-trihydroxybenzyl)-5-cyclohexyl-4-hydroxyphenyl]cyclohexane, 1,8,15,22-tetranonyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane, 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-2-methylbenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(2-hydroxy-5-methylbenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3-ethyl-4-hydroxybenzyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3-ethyl-4-hydroxybenzyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3,5-dimethyl-2-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3,5-dimethyl-2-hydroxyphenyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-3-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-3-isopropylphenyl)phenol], Bis[3-(α,α-bis(3,5-dimethyl-4-hydroxyphenyl)methyl-4-hydroxyphenyl]methane, Bis[3-(α,α-bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)methyl-4-hydroxyphenyl]methane, 4,4'-[4-hydroxy-3,5-bis(2-hydroxybenzyl)methylene]bis[2,6-bis(2-hydroxybenzyl)]phenol, 4,4'-[4-hydroxy-3,5-bis(4-hydroxybenzyl)methylene]bis[2,6-bis(4-hydroxybenzyl)]phenol, 4,4',4"-Ethylidinetris[2,6-bis(2-hydroxybenzyl)phenol], 4,4',4"-Ethylidinetris[2,6-bis(4-hydroxybenzyl)phenol], 2,2-bis[3,5-bis(4-hydroxy-3-methylbenzyl)-4-hydroxyphenyl]propane, 1,8,15,22-tetraethyl-3,5,10,12,17,19,24,26-octahydroxy[1,1,1,1]-metacyclophane, α,α′,α″,α′″-tetrakis(3,5-dimethyl-4-hydroxyphenyl)-1,4-dimethylbenzene, 4,4'-[1-{4-[1-(3,5-bis(2-hydroxy-5-isopropylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(2-hydroxy-5-isopropylphenyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(4-hydroxy-2,3,5-trimethylphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(4-hydroxy-2,3,5-trimethylphenyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3-sec-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3-sec-butyl-4-hydroxyphenyl)phenol], 4,4'-[1-{4-[1-(3,5-bis(3-tert-butyl-4-hydroxyphenyl)-4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bis[2,6-bis(3-tert-butyl-4-hydroxyphenyl)phenol], 2,6-bis{[3-(2,4-dihydroxybenzyl)-2,5-dimethyl-4-hydroxy]benzyl}-4-methylphenol, 1,1-bis[5-(2,4-dihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane, 1,1-bis[5-(2,3,4-trihydroxybenzyl)-3-cyclohexyl-4-hydroxyphenyl]cyclohexane, 2,2-bis[4,4',4'',4'''-tetrakis(3,5-dihydroxymethyl-4-hydroxyphenyl)cyclohexyl]propane Examples include:

[0033] Examples of carboxylic acids and their derivatives include: 3,5-di(α-methylbenzyl)salicylic acid, 4-(2-p-methoxyphenyloxyethoxy)salicylic acid, 4-hydroxyphenylbenzoic acid, 4-chlorobenzoic acid, 4-[2-(p-methoxyphenoxy)ethyloxy]salicylic acid, 4-[3-(p-tolylsulfonyl)propyloxy]salicylic acid, 5-[p-(2-p-methoxyphenoxyethoxy)cumyl]salicylic acid, 4-octyloxycarbonylaminosalicylic acid, 3,5-distyrenated salicylic acid, N-(p-toluenesulfonyl)-glycine, N-(p-toluenesulfonyl)-alanine, N-(p-toluenesulfonyl)-β-alanine, N-phenylaminocarbonyl-glycine, N-phenylaminocarbonyl-valine, N-(m-tolylaminocarbonyl)-phenylalanine, N-(m-tolylaminocarbonyl)-cysteine-S-benzyl, N-(m-tolylaminocarbonyl)-methionine, N-(m-tolylaminocarbonyl)-tyrosine, N-(p-tolylaminocarbonyl)-phenylalanine, N-(p-tolylaminocarbonyl)-cysteine-S-benzyl, N-(p-tolylaminocarbonyl)-methionine, N-(phenylaminocarbonyl)-methionine, N-(p-tolylaminocarbonyl)-tyrosine, 2-O-(phenylaminocarbonyl)-mandelic acid, 2-O-(p-tolylaminocarbonyl)-mandelic acid, 2-O-(m-tolylaminocarbonyl)-mandelic acid, 2-O-(o-tolylaminocarbonyl)-mandelic acid, 2-O-(1-naphthylaminocarbonyl)-mandelic acid, 2-O-(3-isopropenyl-α,α-dimethylbenzylaminocarbonyl)-mandelic acid, 2-O-(benzylaminocarbonyl)-mandelic acid, 2-O-(phenethylaminocarbonyl)-mandelic acid, 2-O-(phenylaminocarbonyl)-lactic acid, 2-O-(p-tolylaminocarbonyl)-lactic acid, 2-O-(m-tolylaminocarbonyl)-lactic acid, 2-O-(o-tolylaminocarbonyl)-lactic acid, 2-O-(1-naphthylaminocarbonyl)-lactic acid, 2-O-(3-isopropenyl-α,α-dimethylbenzylaminocarbonyl)-lactic acid, 2-O-(benzylaminocarbonyl)-lactic acid, 2-O-(phenethylaminocarbonyl)-lactic acid Examples include:

[0034] Examples of acidic phosphate ester compounds include methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, isodecyl acid phosphate, isotridecyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, monobutyl phosphate, dibutyl phosphate, monoisodecyl phosphate, and bis(2-ethylhexyl) phosphate.

[0035] As component (b), a compound having a phenolic hydroxyl group is preferred because it can more effectively exhibit thermochromic properties, but compounds selected from aromatic carboxylic acids, aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphate esters and metal salts thereof, and 1,2,3-triazole and derivatives thereof may also be used.

[0036] The component (c) of the reaction medium that reversibly induces an electron donor-acceptor reaction between the components (a) and (b) in a specific temperature range will now be described. Examples of the component (c) include alcohols, esters, ketones, ethers, and acid amides.

[0037] When a reversible thermochromic composition is encapsulated in microcapsules and used for secondary processing, low molecular weight compounds will evaporate out of the capsules when subjected to high heat treatment, so compounds with 10 or more carbon atoms are preferably used to stably retain the composition within the capsules.

[0038] As the alcohols, aliphatic monohydric saturated alcohols having 10 or more carbon atoms are effective, and examples thereof include decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, heptadecyl alcohol, octadecyl alcohol, eicosyl alcohol, and docosyl alcohol.

[0039] As the esters, esters having 10 or more carbon atoms are effective, and examples thereof include esters obtained from any combination of a monocarboxylic acid having an aliphatic, alicyclic or aromatic ring and a monohydric alcohol having an aliphatic, alicyclic or aromatic ring, esters obtained from any combination of a polycarboxylic acid having an aliphatic, alicyclic or aromatic ring and a monohydric alcohol having an aliphatic, alicyclic or aromatic ring, esters obtained from any combination of a monocarboxylic acid having an aliphatic, alicyclic or aromatic ring and a polyhydric alcohol having an aliphatic, alicyclic or aromatic ring, and Examples of esters include esters obtained from any combination thereof, such as ethyl caprylate, octyl caprylate, stearyl caprylate, myristyl caprate, docosyl caprate, 2-ethylhexyl laurate, n-decyl laurate, 3-methylbutyl myristate, cetyl myristate, isopropyl palmitate, neopentyl palmitate, nonyl palmitate, cyclohexyl palmitate, n-butyl stearate, 2-methylbutyl stearate, 3,5,5-trimethylhexyl stearate, and stearate. n-Undecyl tearic acid, pentadecyl stearate, stearyl stearate, cyclohexylmethyl stearate, isopropyl behenate, hexyl behenate, lauryl behenate, behenyl behenate, cetyl benzoate, stearyl 4-tert-butylbenzoate, dimyristyl phthalate, distearyl phthalate, dimyristyl oxalate, dicetyl oxalate, dicetyl malonate, dilauryl succinate, dilauryl glutarate, diundecyl adipate, dilauryl azelate, di-(n-nonyl) sebacate ), dineopentyl 1,18-octadecylmethylenedicarboxylate, ethylene glycol dimyristate, propylene glycol dilaurate, propylene glycol distearate, hexylene glycol dipalmitate, 1,5-pentanediol distearate, 1,2,6-hexanetriol trimyristate, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanedimethanol dimyristate, xylene glycol dicaprinate, xylene glycol distearate, and the like can be mentioned as examples.

[0040] Also effective are esters of saturated fatty acids and branched fatty alcohols, and ester compounds of unsaturated fatty acids or branched or substituted saturated fatty acids and branched aliphatic alcohols or aliphatic alcohols having 16 or more carbon atoms.

[0041] Examples of the ester compounds include 2-ethylhexyl butyrate, 2-ethylhexyl behenate, 2-ethylhexyl myristate, 2-ethylhexyl caprate, 3,5,5-trimethylhexyl laurate, 3,5,5-trimethylhexyl palmitate, 3,5,5-trimethylhexyl stearate, 2-methylbutyl caproate, 2-methylbutyl caprylate, 2-methylbutyl caprate, 1-ethylpropyl palmitate, 1-ethylpropyl stearate, 1-ethylpropyl behenate, and lauric acid. 1-Ethylhexyl Myristate, 1-Ethylhexyl Palmitate, 2-Methylpentyl Caproate, 2-Methylpentyl Caprylate, 2-Methylpentyl Caprate, 2-Methylpentyl Laurate, 2-Methylbutyl Stearate, 2-Methylbutyl Stearate, 3-Methylbutyl Stearate, 1-Methylheptyl Stearate, 2-Methylbutyl Behenate, 3-Methylbutyl Behenate, 1-Methylheptyl Stearate, 1-Methylheptyl Behenate, 1-Ethyl Caproate Pentyl, 1-ethylpentyl palmitate, 1-methylpropyl stearate, 1-methyloctyl stearate, 1-methylhexyl stearate, 1,1-dimethylpropyl laurate, 1-methylpentyl caprate, 2-methylhexyl palmitate, 2-methylhexyl stearate, 2-methylhexyl behenate, 3,7-dimethyloctyl laurate, 3,7-dimethyloctyl myristate, 3,7-dimethyloctyl palmitate, 3,7-dimethyloctyl stearate, 3,7 behenate Examples include 3,7-dimethyloctyl erucate, stearyl oleate, behenyl oleate, stearyl linoleate, behenyl linoleate, 3,7-dimethyloctyl erucate, stearyl erucate, isostearyl erucate, cetyl isostearate, stearyl isostearate, 2-methylpentyl 12-hydroxystearate, 2-ethylhexyl 18-bromostearate, isostearyl 2-ketomyristate, 2-ethylhexyl 2-fluoromyristate, cetyl butyrate, stearyl butyrate, and behenyl butyrate.

[0042] Furthermore, in order to cause a color change that exhibits large hysteresis characteristics in the color density-temperature curve and to impart color memory properties that depend on temperature changes, exemplified are carboxylic acid ester compounds that exhibit a ΔT value (melting point-cloud point) of 5°C or more and less than 50°C, as described in Japanese Patent Publication No. 4-17154, such as carboxylic acid esters containing a substituted aromatic ring in the molecule, esters of carboxylic acids containing an unsubstituted aromatic ring and aliphatic alcohols having 10 or more carbon atoms, carboxylic acid esters containing a cyclohexyl group in the molecule, esters of fatty acids having 6 or more carbon atoms and unsubstituted aromatic alcohols or phenols, esters of fatty acids having 8 or more carbon atoms and branched aliphatic alcohols, esters of dicarboxylic acids and aromatic alcohols or branched aliphatic alcohols, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, dimyristin, and distearin.

[0043] Also effective are fatty acid ester compounds obtained from an odd-numbered aliphatic monohydric alcohol having 9 or more carbon atoms and an even-numbered aliphatic carboxylic acid, and fatty acid ester compounds having a total of 17 to 23 carbon atoms obtained from n-pentyl alcohol or n-heptyl alcohol and an even-numbered aliphatic carboxylic acid having 10 to 16 carbon atoms.

[0044] Examples of fatty acid ester compounds include n-pentadecyl acetate, n-tridecyl butyrate, n-pentadecyl butyrate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caprylate, n-undecyl caprylate, n-tridecyl caprylate, n-pentadecyl caprylate, n-heptyl caprate, n-nonyl caprate, n-undecyl caprate, n-tridecyl caprate, n-pentadecyl caprate, n-pentyl laurate, n-heptyl laurate, n-nonyl laurate, n-undecyl laurate, n-tridecyl laurate, n-pentadecyl laurate, n-pentyl myristate, and n-heptyl myristate. , n-nonyl myristate, n-undecyl myristate, n-tridecyl myristate, n-pentadecyl myristate, n-pentyl palmitate, n-heptyl palmitate, n-nonyl palmitate, n-undecyl palmitate, n-tridecyl palmitate, n-pentadecyl palmitate, n-nonyl stearate, n-undecyl stearate, n-tridecyl stearate, n-pentadecyl stearate, n-nonyl eicosanoate, n-undelci eicosanoate, n-tridecyl eicosanoate, n-pentadecyl eicosanoate, n-nonyl behenate, n-undecyl behenate, n-tridecyl behenate, n-pentadecyl behenate, and the like.

[0045] As the ketones, aliphatic ketones having a total carbon number of 10 or more are effective, and examples thereof include 2-decanone, 3-decanone, 4-decanone, 2-undecanone, 3-undecanone, 4-undecanone, 5-undecanone, 2-dodecanone, 3-dodecanone, 4-dodecanone, 5-dodecanone, 2-tridecanone, 3-tridecanone, 2-tetradecanone, 2-pentadecanone, 8-pentadecanone, 2-hexadecanone, 3-hexadecanone, 9-heptadecanone, 2-pentadecanone, 2-octadecanone, 2-nonadecanone, 10-nonadecanone, 2-eicosanone, 11-eicosanone, 2-heneicosanone, 2-docosanone, laurone, stearone, and the like.

[0046] Further, aryl alkyl ketones having a total carbon number of 12 to 24, for example, n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradecanophenone, 4-n-dodecaacetophenone, n-tridecanophenone, 4-n-undecanoacetophenone, n-laurophenone, 4-n-decanoacetophenone, n-undecanophenone, 4-n-nonylacetophenone, n-decanophenone, 4-n-octylacetophenone, n ... Examples of acetophenone include 4-n-heptylacetophenone, n-octanophenone, 4-n-hexylacetophenone, 4-n-cyclohexylacetophenone, 4-tert-butylpropiophenone, n-heptaphenone, 4-n-pentylacetophenone, cyclohexyl phenyl ketone, benzyl-n-butyl ketone, 4-n-butylacetophenone, n-hexanophenone, 4-isobutylacetophenone, 1-acetonaphthone, 2-acetonaphthone, and cyclopentyl phenyl ketone.

[0047] As the ethers, aliphatic ethers having a total of 10 or more carbon atoms are effective, and examples thereof include dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecyl ether, diundecyl ether, didodecyl ether, ditridecyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, dioctadecyl ether, decanediol dimethyl ether, undecanediol dimethyl ether, dodecanediol dimethyl ether, tridecanediol dimethyl ether, decanediol diethyl ether, and undecanediol diethyl ether.

[0048] Examples of acid amides include acetamide, propionic acid amide, butyric acid amide, caproic acid amide, caprylic acid amide, capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, erucic acid amide, benzamide, caproic acid anilide, caprylic acid anilide, capric acid anilide, lauric acid anilide, myristic acid anilide, palmitic acid anilide, stearic acid anilide, behenic acid anilide, oleic acid anilide, erucic acid anilide, and N-methyl caproate. amide, caprylic acid N-methylamide, capric acid N-methylamide, lauric acid N-methylamide, myristic acid N-methylamide, palmitic acid N-methylamide, stearic acid N-methylamide, behenic acid N-methylamide, oleic acid N-methylamide, erucic acid N-methylamide, lauric acid N-ethylamide, myristic acid N-ethylamide, palmitic acid N-ethylamide, stearic acid N-ethylamide, oleic acid N-ethylamide, lauric acid N-butylamide, myristic acid N-butylamide, palmitic acid N-butylamide, stearate Stearic acid N-butylamide, oleic acid N-butylamide, lauric acid N-octylamide, myristic acid N-octylamide, palmitic acid N-octylamide, stearic acid N-octylamide, oleic acid N-octylamide, lauric acid N-dodecylamide, myristic acid N-dodecylamide, palmitic acid N-dodecylamide, stearic acid N-dodecylamide, oleic acid N-dodecylamide, dilauric acid amide, dimyristic acid amide, dipalmitic acid amide, distearic acid amide, dioleic acid amide, trilauric acid amide, trilauric acid amide Rimyristic acid amide, tripalmitic acid amide, tristearic acid amide, trioleic acid amide, succinic acid amide, adipic acid amide, glutaric acid amide, malonic acid amide, azelaic acid amide, maleic acid amide, succinic acid N-methylamide, adipic acid N-methylamide, glutaric acid N-methylamide, malonic acid N-methylamide, azelaic acid N-methylamide, succinic acid N-ethylamide, adipic acid N-ethylamide, glutaric acid N-ethylamide, malonic acid N-ethylamide, azelaic acid N-ethylamide, succinic acid N-butylamide,Examples include adipic acid N-butylamide, glutaric acid N-butylamide, malonic acid N-butylamide, adipic acid N-octylamide, and adipic acid N-dodecylamide.

[0049] Furthermore, the component (iii) may be a compound represented by the following formula (2). [ka] [wherein R1 represents a hydrogen atom or a methyl group, m represents an integer of 0 to 2, and either X1 or X2 represents -(CH2) n OCOR2 or (CH2) n COOR2, and the other represents a hydrogen atom; n represents an integer of 0 to 2; R2 represents an alkyl or alkenyl group having 4 or more carbon atoms; Y1 and Y2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom; and r and p each independently represent an integer of 1 to 3.

[0050] Of the compounds represented by formula (2), it is preferable that R1 is a hydrogen atom, since this results in a reversible thermochromic composition with a wider hysteresis width, and it is even more preferable that R1 is a hydrogen atom and m is 0.

[0051] Among the compounds represented by formula (2), the compound represented by the following formula (3) is more preferred. [ka] (In the formula, R represents an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, and more preferably an alkyl group having 12 to 22 carbon atoms.)

[0052] Examples of the compound represented by formula (3) include 4-benzyloxyphenylethyl octanoate, 4-benzyloxyphenylethyl nonanoate, 4-benzyloxyphenylethyl decanoate, 4-benzyloxyphenylethyl undecanoate, 4-benzyloxyphenylethyl dodecanoate, 4-benzyloxyphenylethyl tridecanoate, 4-benzyloxyphenylethyl tetradecanoate, 4-benzyloxyphenylethyl pentadecanoate, 4-benzyloxyphenylethyl hexadecanoate, 4-benzyloxyphenylethyl heptadecanoate, and 4-benzyloxyphenylethyl octadecanoate.

[0053] Furthermore, the component (iii) may be a compound represented by the following formula (4). [ka] (In the formula, R represents an alkyl or alkenyl group having 8 or more carbon atoms, m and n each independently represent an integer of 1 to 3, and X and Y each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom.)

[0054] Examples of the compound represented by formula (4) include 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, 1,1-diphenylmethyl dodecanoate, 1,1-diphenylmethyl tridecanoate, 1,1-diphenylmethyl tetradecanoate, 1,1-diphenylmethyl pentadecanoate, 1,1-diphenylmethyl hexadecanoate, 1,1-diphenylmethyl heptadecanoate, and 1,1-diphenylmethyl octadecanoate.

[0055] Furthermore, the component (iii) may be a compound represented by the following formula (5). [ka] (In the formula, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom; m represents an integer of 1 to 3; and n represents an integer of 1 to 20.)

[0056] Examples of the compound represented by formula (5) include a diester of malonic acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, a diester of succinic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of succinic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol, a diester of glutaric acid and 2-(4-benzyloxyphenyl)ethanol, a diester of glutaric acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, a diester of adipic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of pimelic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of suberic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of suberic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol, a diester of glutaric acid and 2-(4-benzyloxyphenyl)ethanol, a diester of adipic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of pimelic acid and 2-(4-benzyloxyphenyl)ethanol, a diester of suberic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol, a diester of adipic acid and 2-(4-benzyloxyphenyl) ... Examples include the diester of suberic acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, the diester of suberic acid and 2-[4-(2,4-dichlorobenzyloxy)phenyl]ethanol, the diester of suberic acid and 2-[4-(2,4-dichlorobenzyloxy)phenyl]ethanol, the diester of azelaic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of sebacic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of 1,10-decanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of 1,18-octadecanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, and the diester of 1,18-octadecanedicarboxylic acid and 2-[4-(2-methylbenzyloxy)phenyl]ethanol.

[0057] Furthermore, the component (iii) may be a compound represented by the following formula (6). [ka] (In the formula, R represents an alkyl group or alkenyl group having 1 to 21 carbon atoms, and n represents an integer of 1 to 3.)

[0058] Examples of the compound represented by formula (6) include a diester of 1,3-bis(2-hydroxyethoxy)benzene and capric acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and undecanoic acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and lauric acid, a diester of 1,3-bis(2-hydroxyethoxy)benzene and myristic acid, a diester of 1,4-bis(hydroxymethoxy)benzene and butyric acid, a diester of 1,4-bis(hydroxymethoxy)benzene and isovaleric acid, and a diester of 1,4-bis(2-hydroxyethoxy)benzene and acetic acid. Examples of such esters include esters of 1,4-bis(2-hydroxyethoxy)benzene and propionic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and valeric acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and caproic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and caprylic acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and capric acid, diesters of 1,4-bis(2-hydroxyethoxy)benzene and lauric acid, and diesters of 1,4-bis(2-hydroxyethoxy)benzene and myristic acid.

[0059] Furthermore, the component (iii) may be a compound represented by the following formula (7). [ka] (In the formula, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom; m represents an integer of 1 to 3; and n represents an integer of 1 to 20.)

[0060] Examples of the compound represented by formula (7) include a diester of succinic acid and 2-phenoxyethanol, a diester of suberic acid and 2-phenoxyethanol, a diester of sebacic acid and 2-phenoxyethanol, a diester of 1,10-decanedicarboxylic acid and 2-phenoxyethanol, and a diester of 1,18-octadecanedicarboxylic acid and 2-phenoxyethanol.

[0061] Furthermore, the component (iii) may be a compound represented by the following formula (8). [ka] (In the formula, R represents an alkyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, a cycloalkyl group, or an alkenyl group having 4 to 22 carbon atoms; X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom; and n represents 0 or 1.)

[0062] Examples of the compound represented by formula (8) include decyl 4-phenylbenzoate, lauryl 4-phenylbenzoate, myristyl 4-phenylbenzoate, cyclohexylethyl 4-phenylbenzoate, octyl 4-biphenylacetate, nonyl 4-biphenylacetate, decyl 4-biphenylacetate, lauryl 4-biphenylacetate, myristyl 4-biphenylacetate, tridecyl 4-biphenylacetate, pentadecyl 4-biphenylacetate, cetyl 4-biphenylacetate, cyclopentyl 4-biphenylacetate, cyclohexylmethyl 4-biphenylacetate, hexyl 4-biphenylacetate, and cyclohexylmethyl 4-biphenylacetate.

[0063] Furthermore, the component (iii) may be a compound represented by the following formula (9). [ka] (In the formula, R represents an alkyl group having 3 to 18 carbon atoms or an aliphatic acyl group having 3 to 18 carbon atoms; X represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a halogen atom; Y represents a hydrogen atom or a methyl group; and Z represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a halogen atom.) Examples of the compound represented by formula (9) include phenoxyethyl 4-butoxybenzoate, phenoxyethyl 4-pentyloxybenzoate, phenoxyethyl 4-tetradecyloxybenzoate, esters of phenoxyethyl 4-hydroxybenzoate and dodecanoic acid, and dodecyl ether of phenoxyethyl vanillate.

[0064] Furthermore, the component (iii) may be a compound represented by the following formula (10). [ka] (In the formula, R represents any one of an alkyl group having 4 to 22 carbon atoms, an alkenyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, and a cycloalkyl group; X represents any one of a hydrogen atom, an alkyl group, an alkoxy group, and a halogen atom; Y represents any one of a hydrogen atom, an alkyl group, an alkoxy group, and a halogen atom; and n represents 0 or 1.)

[0065] Examples of the compound represented by formula (10) include the benzoate ester of octyl 4-hydroxybenzoate, the benzoate ester of decyl 4-hydroxybenzoate, the 4-methoxybenzoate ester of heptyl 4-hydroxybenzoate, the 2-methoxybenzoate ester of dodecyl 4-hydroxybenzoate, and the benzoate ester of cyclohexylmethyl 4-hydroxybenzoate.

[0066] Furthermore, the component (iii) may be a compound represented by the following formula (11). [ka] (In the formula, R represents any one of an alkyl group having 3 to 18 carbon atoms, a cycloalkylalkyl group having 6 to 11 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, and an alkenyl group having 3 to 18 carbon atoms; X represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and a halogen atom; and Y represents any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, and a halogen atom.)

[0067] Examples of the compound represented by formula (11) include phenoxyethyl ether of nonyl 4-hydroxybenzoate, phenoxyethyl ether of decyl 4-hydroxybenzoate, phenoxyethyl ether of undecyl 4-hydroxybenzoate, and phenoxyethyl ether of dodecyl vanillate.

[0068] Furthermore, the component (iii) may be a compound represented by the following formula (12). [ka] (In the formula, R represents a cycloalkyl group having 3 to 8 carbon atoms or a cycloalkylalkyl group having 4 to 9 carbon atoms, and n represents an integer of 1 to 3.)

[0069] Examples of the compound represented by formula (12) include a diester of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanecarboxylic acid, a diester of 1,4-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid, and a diester of 1,3-bis(2-hydroxyethoxy)benzene and cyclohexanepropionic acid.

[0070] Furthermore, the component (iii) may be a compound represented by the following formula (13). [ka] (In the formula, R represents any one of an alkyl group having 3 to 17 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and a cycloalkylalkyl group having 5 to 8 carbon atoms; X represents any one of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a methoxy group, an ethoxy group, and a halogen atom; and n represents an integer of 1 to 3.)

[0071] Examples of the compound represented by formula (13) include a diester of 4-phenylphenol ethylene glycol ether and cyclohexanecarboxylic acid, a diester of 4-phenylphenol diethylene glycol ether and lauric acid, a diester of 4-phenylphenol triethylene glycol ether and cyclohexanecarboxylic acid, a diester of 4-phenylphenol ethylene glycol ether and octanoic acid, a diester of 4-phenylphenol ethylene glycol ether and nonanoic acid, a diester of 4-phenylphenol ethylene glycol ether and decanoic acid, and a diester of 4-phenylphenol ethylene glycol ether and myristic acid.

[0072] Furthermore, reversible thermochromic compositions of the heat-coloring type (which develops color upon heating and loses color upon cooling) can also be applied (see FIG. 3), using specific alkoxyphenol compounds having a linear or branched alkyl group with 3 to 18 carbon atoms as the electron-accepting compound (Japanese Patent Application Laid-Open Nos. 11-129623 and 11-5973), specific hydroxybenzoic acid esters (Japanese Patent Application Laid-Open No. 2001-105732), or gallic acid esters (Japanese Patent Application Laid-Open Nos. 51-44706 and 2003-253149).

[0073] The above-mentioned reversible thermochromic composition is a compatible solution containing the above-mentioned components (a), (b), and (c) as essential components, and the proportions of each component depend on the concentration, discoloration temperature, discoloration form, and type of each component. Generally, the component ratios that achieve the desired properties are in the range of 1 part of component (a) to 0.1 to 100, preferably 0.1 to 50, and more preferably 0.5 to 20, of component (b), and 5 to 200, preferably 5 to 100, and more preferably 10 to 100, of component (c) (all of the above proportions are in parts by mass).

[0074] Furthermore, the reversible thermochromic composition may contain various light stabilizers as required. The light stabilizer is included to prevent photodegradation of the reversible thermochromic composition consisting of components (A), (B), and (C), and is blended in a proportion of 0.3 to 24% by mass, preferably 0.3 to 16% by mass, per 1% by mass of component (A). Among the light stabilizers, ultraviolet absorbers effectively block ultraviolet rays contained in sunlight and the like, preventing photodegradation caused by the excited state resulting from the photoreaction of component (A). Furthermore, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers, etc., inhibit photooxidation reactions. The light stabilizers may be used alone or in combination of two or more.

[0075] Microencapsulation is carried out by an appropriate method selected depending on the intended use from conventionally known manufacturing methods such as an isocyanate-based interfacial polymerization method, an in situ polymerization method such as a melamine-formalin-based method, a liquid curing coating method, a phase separation method from an aqueous solution, a phase separation method from an organic solvent, a melt-dispersion cooling method, an air suspension coating method, a spray drying method, etc. Furthermore, a secondary resin coating can be provided on the surface of the microcapsules depending on the intended purpose to impart durability or to modify the surface properties for practical use.

[0076] Examples of materials for the microcapsules include organic resins such as epoxy resins, urea resins, urethane resins, and isocyanate resins.

[0077] By providing a secondary resin film on the surface of the microcapsules depending on the purpose, durability can be imparted, and the surface properties can be modified for practical use.

[0078] The mass ratio of the microcapsules (i.e., the microcapsule wall portion not encapsulating the reversible thermochromic composition) to the reversible thermochromic composition is preferably 1 part by mass or more, more preferably 1 part by mass or more, and preferably 7 parts by mass or less, more preferably 6 parts by mass or less, of the reversible thermochromic composition per part by mass of the microcapsules. By using 7 parts by mass or less of the reversible thermochromic composition per part by mass of the microcapsules, it becomes easy to achieve an appropriate wall thickness without the microcapsule wall becoming too thin, making it easy to improve the heat resistance, pressure resistance, etc. of the microcapsule pigment. Furthermore, by using 1 part by mass or more of the reversible thermochromic composition per part by mass of the microcapsules, it becomes easy to improve the color density and clarity when the microcapsule pigment develops color.

[0079] The average particle size of the microcapsules is, for example, in the range of 0.01 to 50 μm, preferably 0.1 to 30 μm, and more preferably 0.5 to 20 μm, which satisfies practicality. In the present invention, the average particle size is a volume-based average particle size (median size). The optimal method for measuring the average particle size is to use a laser diffraction / scattering particle size distribution analyzer calibrated by a direct measurement method, such as the laser diffraction particle size distribution analyzer LA-300 (trade name, manufactured by Horiba, Ltd.).

[0080] Direct measurement methods used for calibration include: (i) Image analysis method to measure the area (2D) of individual particles from images taken with a microscope to determine their equivalent diameter; (ii) The Coulter method (electrical sensing zone method) uses a Coulter counter to pass a constant current through a tiny hole (aperture) in the detector, and measures the equivalent diameter from the change in impedance that occurs when a particle passes through the hole.Calibration of the laser measurement method is performed based on the values ​​obtained by these methods.

[0081] The average particle diameter can be measured by image analysis, for example, by determining the particle region using image analysis particle size distribution measurement software "MacView" (trade name, manufactured by Mountec Co., Ltd.), calculating the diameter equivalent to a circle with a projected area (Heywood diameter) from the area of ​​the particle region, and measuring the average particle diameter of particles equivalent to a sphere with an equal volume using this value. The Coulter method can be used to measure the average particle size when the particle size of all or most of the particles exceeds 0.2 μm. For example, the method can be used with a particle size distribution analyzer, such as the Beckman Coulter Multisizer 4e.

[0082] By encapsulating the reversible thermochromic composition in microcapsules, a chemically and physically stable pigment can be formed. Furthermore, the reversible thermochromic composition maintains the same composition under various conditions of use, allowing it to exhibit the same effects.

[0083] The content of the microencapsulated pigment is preferably 5 to 40% by mass, and more preferably 10 to 30% by mass, based on the total mass of the ink composition. When the content is within this range, it is possible to form handwriting with excellent color development, and it is easy to suppress drying up.

[0084] (shear thinning agent) Effective shear-thinning agents include water-soluble or water-dispersible substances, such as polysaccharides, alkyl alginates, polymers with a molecular weight of 100,000 to 150,000, primarily composed of alkyl esters of methacrylic acid, crosslinked poly(N-vinylcarboxylic acid amide), benzylidene sorbitol, benzylidene xylitol, or derivatives thereof, crosslinkable acrylic acid polymers, inorganic fine particles, nonionic surfactants with an HLB value of 8 to 12, and metal or amine salts of dialkyl sulfosuccinic acid. Furthermore, N-alkyl-2-pyrrolidone and anionic surfactants may be added in combination to the ink composition. Examples of polysaccharides include xanthan gum, welan gum, succinoglycan, guar gum, locust bean gum, λ-carrageenan, cellulose derivatives, zeta sea gum, diutan gum, glucomannan, macrophomopsis gum, and carbohydrates with gelling properties extracted from seaweed, such as agar and carrageenan. The shear thinning agent stabilizes the dispersion of the microcapsule pigment when the ink is at rest and provides good ink ejection during writing.

[0085] The preferred shear thinning agents for ink compositions are polysaccharides, with succinoglycan and xanthan gum being more preferred. Polysaccharides, particularly succinoglycan and xanthan gum, can increase the viscosity of the composition at rest and decrease the viscosity of the composition during writing compared to other shear thinning agents, making it easier to achieve both stable dispersion of the microencapsulated pigment and good ink ejection during writing. Furthermore, because the viscosity of the ink can be adjusted by adding a relatively small amount, they can easily prevent the coating of the shear thinning agent from drying out the nib when water in the ink evaporates from the nib.

[0086] Succinoglycan is a natural product formed by the polymerization of glucose, galactose, succinic acid, and pyruvic acid, and although its molecular weight is difficult to determine, it is generally believed to have a mass-average molecular weight of approximately 1 million. Various succinoglycan products are commercially available, such as LEOSAN (trade name, manufactured by Sansho Co., Ltd.).

[0087] In order to obtain a sufficient effect, the content of the shear thinning agent is preferably 0.01 to 1 mass % and more preferably 0.1 to 0.5 mass % relative to the total mass of the ink composition.

[0088] The ink composition may contain dextrin. The dextrin is preferably, for example, a sugar mixture containing a starch saccharification product of 8 or more sugars and / or its reduced product. The sugar mixture preferably contains 30% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more of the starch saccharification product of 8 or more sugars. This can further improve the resistance to dry-up and can also impart the ability to prevent drooling from the ballpoint pen tip.

[0089] Examples of sugars with octasaccharides or more include starch saccharification products obtained by enzymatic decomposition of starch, and reduced starch saccharification products obtained by reducing the terminal groups of such starch saccharification products. Furthermore, because starch decomposition produces sugars with various degrees of polymerization, completely isolating only the sugars with octasaccharides or more is technically difficult and expensive to produce. Therefore, among sugar mixtures containing sugars with heptasaccharides or less, those containing 30% by mass or more of the sugars with octasaccharides or more can be used, which allows the ink to fully exhibit the aforementioned properties and provide resistance to dry-up and sagging. Examples of sugar mixtures include products obtained by decomposing (e.g., enzymatic decomposition) starch.

[0090] The content of dextrin in the ink composition is preferably 0.5 to 10% by mass. If it is 0.5% by mass or more, dry-up resistance is effectively improved, and if it is 10% by mass or less, problems such as increased viscosity of the ink composition, which can cause bleeding or blobbing or hinder tracking, can be easily avoided, and good dry-up resistance is not adversely affected. The content of dextrin is more preferably 1 to 8% by mass.

[0091] The ink composition may contain known components as long as they do not impair the effects of the present invention. For example, polyvinylpyrrolidone, polyvinyl alcohol, etc. may be contained as necessary. Furthermore, the addition of an oligomer of N-vinyl-2-pyrrolidone, an oligomer of N-vinyl-2-piperidone, N-vinyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, ε-caprolactam, an oligomer of N-vinyl-ε-caprolactam, etc. can improve dry-up resistance and further enhance functionality in a retractable inkjet printer.

[0092] Furthermore, various additives may be contained as necessary. Examples of additives include higher fatty acids such as oleic acid, nonionic surfactants having a long-chain alkyl group, polyether-modified silicone oil, thiophosphite triesters such as thiophosphite tri(alkoxycarbonylmethyl ester) and thiophosphite tri(alkoxycarbonylethyl ester), phosphate monoesters of polyoxyethylene alkyl ethers or polyoxyethylene alkylaryl ethers, phosphate diesters of polyoxyethylene alkyl ethers or polyoxyethylene alkylaryl ethers, and lubricants such as metal salts, ammonium salts, amine salts, and alkanolamine salts thereof.

[0093] In addition, inorganic salts such as sodium carbonate, sodium phosphate, sodium acetate, etc., pH adjusters such as organic basic compounds such as water-soluble amine compounds, rust inhibitors such as benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, saponin, etc., carbolic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl parahydroxybenzoate, 2,3,5,6-tetrachloro-4-(methyl methacrylate) The composition may contain antiseptics or antifungals such as (ethylsulfonyl)pyridine, ascorbic acid, ascorbic acid derivatives, natural or synthetic polyphenols, N-vinylpyrrolidone oligomer, kojic acid, hydroxylamines, oxime derivatives, α-glucosylrutin, oxygen absorbers such as phosphonates, phosphinates, sulfites, sulfoxylates, dithionites, thiosulfates, thiourea dioxide, formamidinesulfinic acid, glutathione, and reaction products of n-butylaldehyde and aniline, antifoaming agents, dispersants, etc.

[0094] The ink composition contains water, but may also contain a water-soluble organic solvent in addition to water. When a water-soluble organic solvent is contained, it is preferable to include it to a degree that does not cause various problems, such as poor ink followability due to an increase in ink viscosity, poor drying of handwriting, or bleeding of handwriting. Alternatively, the ink composition may not contain a water-soluble organic solvent. Examples of water-soluble organic solvents include glycol-based water-soluble organic solvents, such as ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol isopropyl methyl ether, triethylene glycol, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, 1,3-butylene glycol, glycerin, and furfuryl alcohol.

[0095] The ink composition was applied at a shear rate of 3.84 sec -1 The viscosity measured at a shear rate of 384 sec is 300 to 1500 mPa·s. -1 The viscosity of the ink composition is preferably 10 to 100 mPa·s when measured at a shear rate of 3.84 sec -1 The shear rate is 500 to 1000 mPa·s at a shear rate of 384 sec -1 When the viscosity of the ink composition is within the above range, sedimentation, aggregation, etc. of the microcapsule pigment in the ink composition in a stationary state is sufficiently suppressed, and the ink tends to be easily discharged well from the ballpoint pen tip during writing. The viscosity is measured when the ink composition is at 20° C., and the measuring device can be, for example, a rheometer "DHR-2" manufactured by TA Instruments Co., Ltd.

[0096] Furthermore, the water-based ink composition preferably has a shear thinning index n measured at 20° C. and represented by the following general formula (14) of 0.4 to 0.9, more preferably 0.5 to 0.8. T=KJn (14) where T is the shear stress [N / m 2 ], K is the viscosity coefficient (constant), J is the shear rate [sec -1 ]. This sufficiently suppresses settling and aggregation of the microcapsule pigment in the ink composition when it is left to stand, and when writing, the ink from the ballpoint pen tip is ejected without accumulating in the gap between the ball and the ball gripping part, making it easier to create clear handwriting.

[0097] The shear thinning index n can be measured using, for example, a rheometer "DHR-2" manufactured by TA Instruments Co., Ltd., and is 3.84 sec -1 , and 384sec -1 The shear rate and the shear stress (shear stress) obtained at each shear rate are applied to the above general formula (14) to find n.

[0098] The surface tension of the ink composition is preferably 25 to 45 mN / m in an environment of 20°C. By setting the surface tension within the above numerical range, the wetting properties of the ink composition are improved, the ability to form overwritten handwriting is improved when overwriting, and writing properties can be further improved by suppressing bleeding of written lines and strike-through to the paper. Taking the above-mentioned writing properties into further consideration, the surface tension of the aqueous ink composition is more preferably 25 to 40 mN / m, and even more preferably 30 to 40 mN / m. The surface tension is measured by the vertical plate method using a platinum plate at 20° C. As a measuring device, for example, a surface tensiometer (product name: DY-300) manufactured by Kyowa Interface Science Co., Ltd. can be used.

[0099] The ink composition is prepared by adding the microcapsule pigment and, if necessary, various additives to an aqueous medium containing water and a water-soluble organic solvent, and stirring the mixture; then adding a dispersion of the shear-thinning agent in a separately prepared solvent, or the shear-thinning agent itself, and stirring the mixture.

[0100] The ink composition can be used as ink for writing instruments such as marking pens and ballpoint pens.

[0101] The ink composition can be applied to a writing instrument comprising a barrel for accommodating the ink composition and a pen body for delivering the ink composition accommodated in the barrel. The ink composition can be accommodated in the barrel, for example, by being incorporated into an ink occlusion body made of a fiber bundle, or by being directly accommodated in an ink reservoir tube. The pen body can be, for example, a marking pen body or a ballpoint pen body.

[0102] The writing implement may be a marking pen. The structure and shape of the marking pen itself are not particularly limited. Examples of marking pens include a structure in which an ink occlusion body made of a fiber bundle is built into a barrel, and a marking pen body made of a fiber processed body with capillary gaps formed therein is attached to the barrel directly or via an intermediary member, connecting the ink occlusion body and the marking pen body, and the ink occlusion body is impregnated with an ink composition; and a structure in which the marking pen body and an ink reservoir tube are arranged via a valve that opens when the marking pen body is pressed, and ink is directly stored in the ink reservoir tube.

[0103] The marking pen body is a porous material with interconnected pores, such as a resin-processed fiber body, a fused heat-fusible fiber body, or a felt body, which has a porosity selected from a range of approximately 30% to 70%, or an extruded synthetic resin body with multiple ink outlet holes extending in the axial direction, and one end is processed into a shape appropriate for the purpose, such as a bullet shape, a rectangle, or a chisel shape.The ink occlusion body is a bundle of crimped fibers in the longitudinal direction, and is contained within a covering such as a plastic cylinder or film, with a porosity adjusted to a range of approximately 40% to 90%.The valve body can be a pump-type valve, which has been widely used, but a valve with a spring pressure that can be pressed and released by writing pressure is preferable.

[0104] The writing implement may be a ballpoint pen. The structure and shape of the ballpoint pen itself are not particularly limited. An example of a ballpoint pen is one having an ink reservoir tube filled with an ink composition in a barrel, the ink reservoir tube communicating with a ballpoint pen tip having a ball attached to the tip, and a backflow prevention plug in close contact with the end face of the ink composition contained in the ink reservoir tube. A ballpoint pen constructed using the ink composition of the above configuration exhibits good ink ejection from the writing tip and excellent handwriting formation.

[0105] Examples of ballpoint pen tips that can be used include ballpoint pen tips in which the ball is held in a ball-holding portion formed by pressing the vicinity of the tip of a metal pipe inward from the outer surface and deforming it, ballpoint pen tips in which the ball is held in a ball-holding portion formed by cutting a metal material with a drill or the like, ballpoint pen tips in which a resin ball receiving seat is provided inside a metal or plastic tip, and ballpoint pen tips in which the ball held in the ballpoint pen tip is biased forward by a spring. The ball can be made of cemented carbide, stainless steel, ruby, ceramic, resin, rubber, or the like, and can have a diameter of, for example, 0.3 mm to 2.0 mm, preferably 0.3 mm to 1.5 mm, and more preferably 0.3 mm to 1.0 mm.

[0106] The ink reservoir tube that contains the ink composition may be a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, nylon, etc., or a metal tubular body. The ink reservoir tube may be directly connected to a tip, or may be connected to the tip via a connecting member (tip holder).

[0107] The ballpoint pen may have an ink reservoir in the form of a ballpoint pen refill, and the ballpoint pen refill may be housed in a barrel made of resin, metal, etc., or the barrel itself with a ballpoint pen body attached to the tip may be used as the ink reservoir, and ink may be filled directly into the barrel.

[0108] When the ink reservoir is in the form of a ballpoint pen refill, the ballpoint pen refill comprises an ink reservoir that contains an ink composition, and a ballpoint pen body that is attached to the ink reservoir directly or via a connecting member and that holds the ball rotatably.

[0109] Furthermore, when the ink composition is applied to a retractable ballpoint pen, the structure and shape of the retractable ballpoint pen are not particularly limited, and any structure can be used as long as the writing tip provided on the ballpoint pen refill is housed in the barrel while exposed to the outside air, and the writing tip protrudes from the barrel opening by activation of the retraction mechanism. Examples of operating methods for the retraction mechanism include knocking, rotating, and sliding. Examples of knocking types include a configuration in which a knock part is provided at the rear end or side of the barrel, and the writing tip is protruded and retracted from the barrel front opening by pressing the knock part, or a configuration in which the writing tip is protruded and retracted from the barrel front opening by pressing a clip part provided on the barrel. Examples of rotating types include a configuration in which a rotating part is provided at the rear of the barrel, and the writing tip is protruded and retracted from the barrel front opening by rotating the rotating part. The sliding type may be exemplified by a configuration in which a sliding portion is provided on the side of the barrel, and the writing tip portion is protruded and retracted from the front end opening of the barrel by operating the slide, or a configuration in which the writing tip portion is protruded and retracted from the front end opening of the barrel by sliding a clip portion provided on the barrel. The retractable ballpoint pen may be a composite type retractable ballpoint pen that contains multiple ballpoint pen refills in the barrel, and in which the writing tip portion of one of the ballpoint pen refills is protruded and retracted from the front end opening of the barrel by operating a retraction mechanism.

[0110] An ink backflow preventive is filled at the rear end of the ink composition contained in the ink reservoir tube. The ink backflow preventive is made of a non-volatile liquid or a low-volatile liquid. Specific examples include 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, polyether-modified silicone oil, and fatty acid-modified silicone oil. One type may be used alone, or two or more types may be used in combination. It is preferable to add a thickener to at least one of the non-volatile liquid and the low-volatile liquid to thicken it to a suitable viscosity. Examples of thickeners include clay-based thickeners such as silica whose surface has been hydrophobically treated, fine particle silica whose surface has been methylated, aluminum silicate, swellable mica, hydrophobically treated bentonite, and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, and zinc stearate, dextrin-based compounds such as tribenzylidene sorbitol, fatty acid amides, amide-modified polyethylene wax, hydrogenated castor oil, and fatty acid dextrins, and cellulose-based compounds. Furthermore, a liquid ink backflow preventer and a solid ink backflow preventer can also be used in combination.

[0111] The marking pen and ballpoint pen are not limited to the above-mentioned forms, and may be double-ended writing implements equipped with pen bodies of different forms or with pen bodies that dispense ink compositions of different colors.

[0112] The handwriting obtained by writing on a surface using a writing instrument containing a reversible thermochromic aqueous ink composition can be discolored using a heating or cooling tool. Examples of heating tools include an electrically heated color-changing tool equipped with a resistance heating element, a heat-discoloring tool filled with hot water, or a hair dryer, but preferably a friction member is used as a means for easily changing the color. That is, the writing instrument may further include a friction member.

[0113] Suitable friction members are elastic or viscoelastic materials such as elastomers and plastic foams, which have a high elastic feel and can generate moderate friction and frictional heat when rubbed. While it is possible to rub the handwriting with an eraser, this generates eraser dust, so the aforementioned friction members that generate almost no eraser dust are preferably used. Suitable materials for the friction member include silicone resin, SEBS resin (styrene-ethylene-butadiene-styrene block copolymer), polyester resin, and α-olefin copolymer.

[0114] The friction member may be a separate member (friction body) of any shape that is separate from the writing instrument, and may be combined with the writing instrument to form a writing instrument set; however, providing the friction member on the writing instrument provides excellent portability. In the case of a writing instrument with a cap, the location where the friction member is provided is not particularly limited, but for example, the cap itself can be formed from a friction member, the barrel itself can be formed from a friction member, or if a clip is provided, the clip itself can be formed from a friction member, or the 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. For example, the barrel itself may be made of a friction member, or if a clip is provided, the clip itself may be made of a friction member, or the friction member may be provided near the barrel opening, at the rear end of the barrel (the part where the writing tip is not provided), or at the knock portion.

[0115] Examples of cooling devices include thermochromic devices using a Peltier element, thermochromic devices filled with a refrigerant such as cold water or ice chips, and refrigerators and freezers. [Example]

[0116] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" are by mass. In this example, the average particle size of the microcapsule pigment was measured as a volume-based average particle size (median size) using the laser diffraction / scattering particle size distribution analyzer (device name: LA-300, manufactured by Horiba, Ltd.) calibrated by the Coulter method (electrical detection zone method).

[0117] Preparation of microcapsule pigment (1) Microcapsule pigment 1 was prepared by encapsulating in microcapsules a reversible thermochromic composition a having color memory, which was composed of 1.0 parts of spiro[5H-(1)benzopyrano[2,3-d]pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(diethylamino)-8-(diethylamino)-4-methyl as an electron-donating color-forming organic compound, 3.0 parts of 1,1-bis(4-hydroxyphenyl)-2-ethylhexane and 5.0 parts of 2,2-bis(4'-hydroxyphenyl)-hexafluoropropane as electron-accepting compounds, and 50.0 parts of 4-benzyloxyphenylethyl caprate as a reaction medium. The average particle size of the microcapsule pigment 1 was 2.0 μm, the complete decolorization temperature (t4) was 53° C., the complete color development temperature (t1) was −20° C., and the color changed from pink to colorless with temperature change.

[0118] Preparation of microcapsule pigment (2) Microcapsule pigment 2 was prepared by encapsulating in microcapsules a reversible thermochromic composition b having color memory properties, which was composed of an electron-donating color-forming organic compound and 1.0 part of 3,6-bis(diphenylamino)fluoran as components, 3.0 parts of 1,1-bis(4-hydroxyphenyl)-2-ethylhexane and 5.0 parts of 2,2-bis(4'-hydroxyphenyl)-hexafluoropropane as electron-accepting compounds, and 50.0 parts of 4-benzyloxyphenylethyl caprate as a reaction medium. The average particle size of the microcapsule pigment 2 was 1.8 μm, the complete decolorization temperature (t4) was 55° C., the complete color development temperature (t1) was −20° C., and the color changed from blue to colorless with temperature change.

[0119] Preparation of ink composition Ink compositions No. 1 to No. 7 were prepared with the compositions shown in Table 1 below. The numerical values ​​for the compositions in the table represent mass %, and "-" indicates that no additive was added. Note that No. 1 to No. 4 correspond to working examples, and No. 5 to No. 7 correspond to comparative examples.

[0120] The viscosity of the ink composition was measured at 20°C using a rheometer "DHR-2" manufactured by TA Instruments.

[0121] The surface tension of the ink composition was measured by a surface tensiometer (product name: DY-300) manufactured by Kyowa Interface Science Co., Ltd. at 20°C by the vertical plate method using a platinum plate.

[0122] [Table 1]

[0123] Each component in the table is explained in detail below. (1) Xanthan gum (product name: Kelzan, manufactured by Sansho Co., Ltd.) (2) Succinoglycan (trade name: Leozan, manufactured by Sansho Co., Ltd.) (3) Product name: Sandec 70 (containing 70% by mass or more of starch saccharification products of 8 or more sugars and / or their reduced products), manufactured by Sanwa Starch Industry Co., Ltd. (4) Polyoxyethylene styrylphenyl phosphate ester (trade name: Plysurf AL, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) (5) Substance of general formula (1): -COR1 and -COR2 are lauroyl groups (trade name: Pellicer L-30, active ingredient content: 29% by mass, manufactured by Asahi Kasei Finechem Co., Ltd.) (6) 1,2-benzisothiazol-3(2H)-one (trade name: Proxel XL-2; manufactured by Lonza Japan)

[0124] Making ballpoint pen refills Each ink composition was filled into an ink reservoir made of polypropylene resin and equipped at its tip with a ballpoint pen tip that rotatably holds a 0.5 mm outer diameter cemented carbide ball. The rear end was filled with an ink backflow preventive agent made of a viscous liquid. A tail plug was then fitted to the rear of the pipe to obtain a ballpoint pen refill.

[0125] Making a ballpoint pen The obtained ballpoint pen refill was attached to the exterior of a ballpoint pen (product name: FriXion Ball 05, manufactured by Pilot Corporation). The obtained ballpoint pen was used to carry out the following tests. The results are shown in Table 2. The test paper used for the writing test was writing paper A conforming to the old JIS P3201.

[0126] (Evaluation of overwriting ability) A square measuring 1 cm on each side was filled in on the test paper with the ballpoint pen, and the square was rubbed with the rubbing material attached to the rear end of the ballpoint pen to erase the color. After that, the ballpoint pen used to fill in the square was used to write (letter: #) on the erased square, and the overwritten mark was visually observed. ◯: No blurring or breaks in the characters are observed, or slight blurring or breaks in the characters are observed, but this does not pose a problem in practical use. ×: Blurred or broken characters are clearly visible, and there is a problem in practical use.

[0127] (Evaluation of dry-up resistance) The ballpoint pen was placed horizontally with the nib exposed and stored in an environment of 50°C and 30% RH for 7 days. After that, 12 spiral circles were written by hand in one line on a test piece of paper at room temperature, and the handwriting was observed visually. ○: A smooth and uninterrupted handwriting can be formed from the start to the end of writing. Or, the handwriting is slightly blurred or broken immediately after starting to write. However, these were not found in the handwriting at the end of the writing. ×: Impossible to write.

[0128] (Evaluation of continuous writing ability) A ballpoint pen was attached to an automatic writing tester, and spiral circles were continuously written on the test paper until all the ink was consumed, and the writing was visually observed. ○: Clear handwriting is formed from the start to the end of writing. ×: Writing became impossible before all the ink was consumed.

[0129] [Table 2] [Explanation of symbols]

[0130] t1 Full color temperature t2 Color development start temperature t3 Discoloration start temperature t4 Complete color erasure temperature T1 Complete color fading temperature T2 Decolorization start temperature T3 Color development start temperature T4 full color temperature

Claims

1. An ink composition comprising: a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising (a) an electron-donating organic color-forming compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color-forming reactions of (a) and (b) occur; a substance represented by the following general formula (1); a shear-thinning agent; and water, A reversibly thermochromic aqueous ink composition for a writing instrument, wherein the content of a substance represented by general formula (1) is 0.01 to 2.0 mass % based on the total mass of the ink composition. 【Chemical 1】 In the formula, R1 and R2 are independently an alkyl group or alkenyl group having 8 to 20 carbon atoms, and X1, X2, and X3 are independently hydrogen, an alkali metal, ammonium, or an alkanolamine.

2. 2. The water-based ink composition according to claim 1, wherein the content of the substance represented by the general formula (1) is 0.05 to 0.5% by mass based on the total mass of the ink composition.

3. A writing instrument containing the aqueous ink composition described in claim 1 or 2.

4. A writing instrument as described in claim 3, which is provided with a friction member.

5. A writing instrument as described in claim 3 or 4, which is a ballpoint pen.

6. A ballpoint pen refill containing the aqueous ink composition described in claim 1 or 2.

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