JP7011928B2 - Reversible thermochromic composition and reversible thermochromic microcapsule pigment containing it - Google Patents

Description

The present invention relates to a reversible thermochromic composition and a reversible thermochromic microcapsule pigment containing the same. More specifically, the present invention relates to a reversible thermochromic composition which exhibits yellow to red color at the time of color development and becomes colorless at the time of decolorization, and a reversible thermochromic microcapsule pigment containing the same.

Conventionally, a reaction medium that reversibly causes an electron transfer reaction between an electron-donating color-developing organic compound, an electron-accepting compound, and the electron-donating color-developing organic compound and an electron-accepting compound in a specific temperature range is essential. Several proposals have been disclosed regarding reversible thermochromic compositions that change color from yellow to orange as a component to colorless (see, for example, Patent Documents 1 to 3).
The above-mentioned conventional reversible thermochromic composition uses a pyridine compound as an electron-donating color-developing organic compound capable of exhibiting a yellow to orange color, and although it has fluorescence and exhibits a vivid color. This type of reversible thermochromic composition has poor light resistance and may reduce color density, especially when exposed to light during color development.

Japanese Unexamined Patent Publication No. 7-186540 Japanese Unexamined Patent Publication No. 8-127768 Japanese Unexamined Patent Publication No. 2012-46556

The present invention solves the above-mentioned conventional problems, that is, it exhibits a bright yellow to red color in a color-developed state, changes its color to colorless in a decolorized state, and has excellent light resistance. It is an object of the present invention to provide a reversible thermochromic composition capable of maintaining a contrast between a color at the time of color development and a color at the time of decolorization, and a reversible thermochromic microcapsule pigment containing the same.

（式中、Ｒ_１及びＲ_２はそれぞれ独立して水素原子、炭素数１～６のアルキル基、炭素数１～６のアシル基又は置換若しくは無置換の炭素数６～２０のアリール基であり、Ｒ_３乃至Ｒ_７はそれぞれ独立して水素原子、炭素数１～８のアルキル基、炭素数１～６のアルコキシ基又はハロゲン基であり、Ｒ_８乃至Ｒ_１２はそれぞれ独立して水素原子、炭素数１～８のアルキル基、炭素数１～６のアルコキシ基又はハロゲン基であり、Ａｒは置換又は無置換の芳香族複素環基である。）
更には、前記ピリジン誘導体のＲ_１及びＲ_２はそれぞれ独立して炭素数１～６のアルキル基、置換若しくは無置換の炭素数６～２０のアリール基であること、Ｒ_１及びＲ_２はエチル基又はｐ－トリル基であること、Ａｒはチエニル基、フリル基、チアゾリル基、ピリジニル基のいずれかであること等を要件とする。
更には、前記可逆熱変色性組成物を内包した可逆熱変色性マイクロカプセル顔料を要件とする。
更には、前記可逆熱変色性マイクロカプセル顔料と、ビヒクルとからなる可逆熱変色性液状組成物、前記可逆熱変色性マイクロカプセル顔料と、成形用樹脂とからなる可逆熱変色性成形用樹脂組成物、前記可逆熱変色性マイクロカプセル顔料を含む可逆熱変色層を設けてなる可逆熱変色性積層体を要件とする。 The present invention comprises (a) a pyridine derivative represented by the following general formula (1) as an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) the above-mentioned (a) and (b) components. A reversible thermochromic composition comprising a reaction medium that reversibly causes an electron transfer reaction in a specific temperature range is required.

(In the formula, R ₁ and R ₂ are independently hydrogen atoms, alkyl groups having 1 to 6 carbon atoms, acyl groups having 1 to 6 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 20 carbon atoms, respectively. , R ₃ to R ₇ are independent hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, alkoxy groups or halogen groups having 1 to 6 carbon atoms, and R ₈ to R ₁₂ are independent hydrogen atoms, respectively. It is an alkyl group having 1 to 8 carbon atoms, an alkoxy group or a halogen group having 1 to 6 carbon atoms, and Ar is a substituted or unsubstituted aromatic heterocyclic group.)
Furthermore, R ₁ and R ₂ of the pyridine derivative are independently alkyl groups having 1 to 6 carbon atoms and substituted or unsubstituted aryl groups having 6 to 20 carbon atoms, and R ₁ and R ₂ are ethyl. It is required that it is a group or a p-tolyl group, and that Ar is any one of a thienyl group, a frill group, a thiazolyl group and a pyridinyl group.
Further, a reversible thermochromic microcapsule pigment containing the reversible thermochromic composition is required.
Further, the reversible thermochromic microcapsule pigment, the reversible thermochromic liquid composition composed of the vehicle, the reversible thermochromic microcapsule pigment, and the reversible thermochromic molding resin composition comprising the molding resin. The requirement is a reversible thermochromic laminate provided with a reversible thermochromic layer containing the reversible thermochromic microcapsule pigment.

In the present invention, by using a specific pyridine derivative as an electron-donating color-developing organic compound, a vivid yellow to red color is exhibited at the time of color development, and the color becomes colorless at the time of decolorization. A discolorable composition and a reversible thermochromic microcapsule pigment containing the same can be obtained.

It is a graph explaining the hysteresis characteristic in the color density | temperature curve of the heat decolorizing type reversible thermochromic composition. It is a graph explaining the hysteresis characteristic in the color density-temperature curve of the heat decolorizing type reversible thermochromic composition having color memory. It is a graph explaining the hysteresis characteristic in the color density | temperature curve of the reversible thermochromic composition of a heating color development type.

The reversible thermochromic composition includes (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) an essential reaction medium for determining the temperature at which the color reaction of both of them occurs. Examples thereof include a heat-decoloring type (decoloring by heating and developing color by cooling) reversible thermochromic composition containing at least a component.
The reversible thermochromic composition changes color before and after a predetermined temperature (discoloration point), and is in a decolorized state in a temperature range above the high temperature side discoloration point and in a color development state in a temperature range below the low temperature side discoloration point. Presented, only one of the above states exists in a specific temperature range, and the other state is maintained as long as the heat or cold required for the state to develop is applied. However, it has a characteristic that the hysteresis width (ΔH) is relatively small, which returns to the original state when the application of the heat or cold heat is removed (see FIG. 1).
In addition, the shape of the curve showing a large hysteresis characteristic, that is, plotting the change in coloring density due to temperature change, decreases from the high temperature side of the discoloration temperature range, contrary to the case where the temperature rises from the low temperature side of the discoloration temperature range. The color changes by following a path that is significantly different from that of the case where the color is changed, and the color development state in the low temperature range below the complete color development temperature (t ₁ ) or the decolorization state in the high temperature range above the complete decolorization temperature (t ₄ ) , Reversible heat of heat decolorization type (decolorizes by heating and develops color by cooling) having color memory in a specific temperature range [temperature range between t ₂ and t ₃ (substantially two-phase holding temperature range)] A discolorable composition can also be applied (see FIG. 2).

The components (a), (b), and (c) will be specifically described below.
The pyridine derivative represented by the general formula (1) has an aromatic heterocycle at the 4-position of the pyridine ring, has excellent light resistance, and exhibits a bright yellow to red color.
The pyridine derivative represented by the formula (1) is specifically exemplified below.

In the pyridine derivative, R ₁ and R ₂ are independently hydrogen atoms, a linear or branched alkyl group having 1 to 6 carbon atoms, an acyl group having 1 to 6 carbon atoms, or substituted or unsubstituted carbon atoms of 6 to 20. R ₃ to R ₇ are independently hydrogen atoms, a linear or branched alkyl group having 1 to 8 carbon atoms, and a linear or branched alkoxy group or halogen group having 1 to 6 carbon atoms. R ₈ to R ₁₂ are independently hydrogen atoms, a linear or branched alkyl group having 1 to 8 carbon atoms, a linear or branched alkoxy group or a halogen group having 1 to 6 carbon atoms, and Ar is substituted or unsubstituted. Although it is an aromatic heterocyclic group, _R1 and _R2 are independently linear or branched alkyl groups having 1 to 6 carbon atoms in order to exhibit a more vivid color at the time of color development and improve light resistance. , A substituted or unsubstituted aryl group having 6 to 20 carbon atoms is preferable, and an ethyl group or a p-tolyl group is more preferable.

The alkyl groups having 1 to 6 carbon atoms in R ₁ and R ₂ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, t-butyl group and n-. Examples thereof include a pentyl group, an i-pentyl group, a neo-pentyl group, an n-hexyl group, and the like, preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, and i. -Propyl group, n-butyl group, sec-butyl group, t-butyl group can be mentioned.

Examples of the acyl group having 1 to 6 carbon atoms in R ₁ and R ₂ include a formyl group, an acetyl group, an n-propionyl group, and an i-propionyl group. Further, the acyl group also includes, for example, a succinimide group in which two carboxylic acids bonded to an amino group are condensed to form a cyclic structure having two acyl groups.

Examples of the substituted or unsubstituted aryl group having 6 to 20 carbon atoms in R ₁ and R ₂ include a phenyl group and a naphthyl group.
The aryl group having 6 to 20 carbon atoms may have a substituent, and examples of the substituent include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group and a sec-butyl group. , An alkyl group having 1 to 4 carbon atoms such as a t-butyl group, a halogen atom such as F, Cl, Br or I, a nitro group, a cyano group, a hydroxyl group, a carboxylic acid group, and an alkoxy group having 1 to 3 carbon atoms. Be done.
The substituent is preferably an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 3 carbon atoms from the viewpoint of color development and solubility.

Specific examples of amino groups substituted with R ₁ and R ₂ are shown in the table below, but the present invention is not limited thereto. In the structural formula in the table, * represents a binding site.

The halogen atom in R ₃ to R ₇ is F, Cl, Br or I or the like, preferably Cl or Br. Alkyl groups having 1 to 8 carbon atoms are methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, t-butyl group, n-pentyl group, i-pentyl group, It is a neo-pentyl group, an n-hexyl group, an n-octyl group, a 2-ethylhexyl group and the like. The alkoxy group having 1 to 6 carbon atoms is a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group, an n-butoxy group, an n-pentyloxy group, an n-hexyloxy group and the like. As the alkoxy group having 1 to 6 carbon atoms, a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group and the like are suitable.
From the viewpoint of light resistance, fluorescence color development, and dissolution stability of the pyridine compound, at least one of R ₃ to R ₇ is preferably an alkoxy group having 1 to 6 carbon atoms. Further, it is more preferable that two of R ₃ to R ₇ are alkoxy groups having 1 to 6 carbon atoms. The substitution position of the alkoxy group is not particularly limited, but when it is substituted at the ortho-position and / or the para-position from the viewpoint of fluorescence color development and color stability, it emits vivid fluorescence.

R ₈ to R ₁₂ are basically the same as R ₃ to R ₇ , and are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a halogen atom. Specifically, the halogen atom is F, Cl, Br, I or the like, preferably Cl or Br. Alkyl groups having 1 to 8 carbon atoms are methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, t-butyl group, n-pentyl group, i-pentyl group, It is a neo-pentyl group, an n-hexyl group, an n-octyl group, a 2-ethylhexyl group and the like. The alkoxy group having 1 to 6 carbon atoms is a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group, an n-butoxy group, an n-pentyloxy group, an n-hexyloxy group and the like. As the alkoxy group having 1 to 6 carbon atoms, a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group and the like are suitable.
From the viewpoint of light resistance, fluorescence color development, and dissolution stability of the pyridine compound, at least one of R ₈ to R ₁₂ is preferably an alkoxy group having 1 to 6 carbon atoms. Further, it is more preferable that two of R ₈ to R ₁₂ are alkoxy groups having 1 to 6 carbon atoms. The substitution position of the alkoxy group is not particularly limited, but when it is substituted at the ortho-position and / or the para-position from the viewpoint of fluorescence color development and color stability, it emits vivid fluorescence.

Specific examples of the substituents (R ₃ to R ₁₂ ) of the phenyl group substituting at the 2-position and the 6-position of the pyridine ring are shown in the table below. The substituent is not limited to the description in the table.

The fluorescent color-developing property of the pyridine derivative is affected by the substitution position of the substituent of the phenyl group substituted on the pyridine ring. In the pyridine compound, the substitution position of the substituent of the phenyl group to be substituted with the pyridine ring is preferably the 2-position and / or the 4-position.

Ar represents a substituted or unsubstituted aromatic heterocyclic group. The aromatic heterocyclic group is, for example, a cyclic compound composed of two or more kinds of elements, and is a pyrrolyl group, a pyrazolyl group, a thienyl group, a frill group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyrazinyl group, and the like. Examples thereof include a pyridazinyl group and a pyrimidinyl group. In the pyridine compound, when Ar is a pyridinyl group, a pyrazinyl group, a pyridadinyl group, or a pyrimidinyl group which is a nitrogen-containing aromatic heterocyclic group, the light resistance is improved. On the other hand, when Ar is an oxygen-containing or sulfur-containing aromatic heterocyclic group, for example, a thienyl group or a frill group, the maximum absorption wavelength is lengthened and the color is developed in red.
The substituent of Ar is not particularly limited, but is an alkyl having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group and a t-butyl group. Examples thereof include a halogen atom such as a group, F, Cl, Br or I, a nitro group, a cyano group, a hydroxyl group, a carboxylic acid group or an alkoxy group having 1 to 3 carbon atoms.
Ar is preferably any one of a thienyl group, a frill group, a thiazolyl group and a pyridinyl group.

The pyridine derivative is J. Am. Chem. Soc. , 1952, 74 (1), 200-202 and the like. More specifically, in the presence of ammonia or an ammonia generating agent, an acetphenone derivative and a benzaldehyde derivative are heat-condensed under an acid catalyst such as acetic acid to synthesize a cyclized product, and the obtained cyclized product is aminated. It can be obtained by going through an aminization step.

Examples of the electron-accepting compound of the component (b) include a group of compounds having an active proton, a group of pseudoacid compounds (not an acid, but a group of compounds that act as an acid in the composition to develop the color of the component (a)). There are compounds having electron vacancies and the like.
Examples of compounds having an active proton include monophenols to polyphenols as compounds having a phenolic hydroxyl group, and as its substituents, an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carboxy group and an ester thereof. Alternatively, those having an amide group, a halogen group and the like, bis-type and Tris-type phenols and the like, phenol-aldehyde condensed resins and the like can be mentioned. Further, it may be a metal salt of the compound having a phenolic hydroxyl group.
Specific examples are given below.
Phenol, o-cresol, tertiary butyl catechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, p-hydroxybenzoate n-butyl , P-Hydroxybenzoate n-octyl, resorcin, dodecyl phosphite, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide, bis (3-allyl-4-hydroxyphenyl) sulfone, 4-hydroxy Phenyl-4-isopropoxyphenyl sulfone, 4-benzyloxyphenyl-4-hydroxyphenyl sulfone, 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) 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-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-phenyl-1,1-bis (4-hydroxyphenyl) ethane, 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) 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 (4-hydroxy-3-methylphenyl) propane, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 1,3-bis [2- (4-Hydroxyphenyl) -2-propyl] benzene, bis (2-hydroxyphenyl) methane, 1,1,1-tris (4-hydroxyphenyl) ethane, 2,2-bis (3-methyl- 4-Hydroxyphenyl) butane, 4-t-butyl-2', 4'-dihydroxybenzophenone and the like.
The compound having a phenolic hydroxyl group can exhibit the most effective thermal discoloration property, but is an aromatic carboxylic acid, an aliphatic carboxylic acid having 2 to 5 carbon atoms, a carboxylic acid metal salt, an acidic phosphoric acid ester, and the like thereof. It may be a compound selected from a metal salt, 1,2,3-triazole and a derivative thereof.

The component (c) of the reaction medium that reversibly causes the electron transfer reaction by the components (a) and (b) in a specific temperature range will be described.
Examples of the component (c) include alcohols, esters, ketones, ethers, and acid amides.
When the compound is applied to microencapsulation and secondary processing, low molecular weight compounds evaporate outside the capsule when subjected to high heat treatment, so the number of carbon atoms is 10 or more in order to stably retain the compound in the capsule. Compounds are preferably used.
As alcohols, aliphatic monohydric saturated alcohols having 10 or more carbon atoms are effective, and specifically, decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, and hexadecyl. Examples thereof include alcohols, heptadecyl alcohols, octadecyl alcohols, eicosyl alcohols, docosyl alcohols and the like.

As the esters, esters having 10 or more carbon atoms are effective, and any combination of a monovalent carboxylic acid having an aliphatic and an alicyclic or aromatic ring and a monovalent alcohol having an aliphatic and an alicyclic or aromatic ring is effective. Esters, aliphatic and alicyclic esters obtained from any combination of a polyvalent carboxylic acid having an aliphatic and alicyclic or aromatic ring and a monovalent alcohol having an alicyclic or alicyclic or aromatic ring. Alternatively, esters obtained from any combination of monovalent carboxylic acid having an aromatic ring and an aliphatic and polyvalent alcohol having an alicyclic or aromatic ring can be mentioned, and specific examples thereof include ethyl caprylate, octyl caprylate, and capryl. Stearyl acid, myristyl caprate, docosyl caprate, 2-ethylhexyl laurate, n-decyl laurate, 3-methylbutyl myristate, cetyl myristine, isopropyl palmitate, neopentyl palmitate, nonyl palmitate, cyclohexyl palmitate, stearer N-butyl acid, 2-methylbutyl stearate, 3,5,5-trimethylhexyl stearate, n-undecyl stearate, pentadecyl stearate, stearyl stearate, cyclohexylmethyl stearate, isopropyl behenate, hexyl behenate, behen Lauryl acid, behenyl behenyl, cetyl benzoate, p-tert-butyl stearyl benzoate, dimyristyl phthalate, disstearyl phthalate, dimyristyl oxalate, disetyl oxalate, disetyl malonate, dilauryl succinate, dilauryl glutarate, adipine Diundecyl acid, dilauryl azelaite, di- (n-nonyl) sebacate, dineopentyl 1,18-octadecylmethylene dicarboxylate, ethylene glycol dimyristate, propylene glycol dilaurate, propylene glycol distearate, hexylene glycol dipalmitate, 1,5-Pentanediol distearate, 1,2,6-hexanetrioltrimylstate, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanedimethanol dimyristate, xylene glycol dicaprineate, xylene glycol Examples include distearate.

Also, esters of saturated fatty acids and branched aliphatic alcohols, esters of unsaturated fatty acids or aliphatic alcohols branched from saturated fatty acids having branches or substituents or having 16 or more carbon atoms, cetyl butyrate, stearyl butyrate and Ester compounds selected from behenyl butyrate are also effective.
Specifically, 2-ethylhexyl butyrate, 2-ethylhexyl behenate, 2-ethylhexyl myristate, 2-ethylhexyl capric acid, 3,5,5-trimethylhexyl laurate, 3,5,5-trimethylhexyl palmitate, 3,5,5-trimethylhexyl stearate, 2-methylbutyl caproate, 2-methylbutyl caprylate, 2-methylbutyl caprice, 1-ethylpropyl palmitate, 1-ethylpropyl stearate, 1-ethylpropyl behenate, 1-ethylhexyl laurate, 1-ethylhexyl myristate, 1-ethylhexyl palmitate, 2-methylpentyl caproate, 2-methylpentyl caprylate, 2-methylpentyl capric acid, 2-methylpentyl laurate, 2-methylpentyl stearate Methylbutyl, 2-methylbutyl stearate, 3-methylbutyl stearate, 1-methylheptyl stearate, 2-methylbutyl behenate, 3-methylbutyl behenate, 1-methylheptyl stearate, 1-methylheptyl behenate, 1 caproic acid -Ethylpentyl, 1-ethylpentyl palmitate, 1-methylpropyl stearate, 1-methyloctyl stearate, 1-methylhexyl stearate, 1,1-dimethylpropyl lauric acid, 1-methylpentyl capric acid, palmitic acid 2-Methylhexyl, 2-methylhexyl stearate, 2-methylhexyl behenate, 3,7-dimethyloctyl laurate, 3,7-dimethyloctyl myristate, 3,7-dimethyloctyl palmitate, 3, stearate 7-Dimethyloctyl, 3,7-dimethyloctyl behenate, stearyl oleate, behenyl oleate, stearyl linoleate, behenyl linoleate, 3,7-dimethyloctyl erucate, stearyl erucate, isostearyl erucate, isostearic acid Cetyl, stearyl isostearate, 2-methylpentyl 12-hydroxystearate, 2-ethylhexyl 18-bromostearate, isostearyl 2-ketomyristate, 2-ethylhexyl 2-fluoromyristine, cetyl butyrate, stearyl butyrate, behenyl butyrate And so on.

Further, in order to change the color by showing a large hysteresis characteristic with respect to the color density-temperature curve and to give color memory depending on the temperature change, it is described in Japanese Patent Publication No. 4-17154 and has a temperature of 5 ° C or higher and lower than 50 ° C. A carboxylic acid ester compound showing a ΔT value (melting point-cloud point), for example, a carboxylic acid ester containing a substituted aromatic ring in the molecule, a carboxylic acid containing an unsubstituted aromatic ring, and an ester of an aliphatic alcohol having 10 or more carbon atoms. , Esters containing cyclohexyl groups in molecules, fatty acids with 6 or more carbon atoms and unsubstituted aromatic alcohols or phenol esters, fatty acids with 8 or more carbon atoms and branched aliphatic alcohols or esters, dicarboxylic acids and aromatic alcohols or Esters of branched aliphatic alcohols, dibenzyl silicate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, disetyl adipate, distearyl adipate, trilaurin, trimyristin, tristea, dimyristin, distea, etc. Can be mentioned.

An odd aliphatic monohydric alcohol having 9 or more carbon atoms and a fatty acid ester compound obtained from an aliphatic carboxylic acid having an even number of carbon atoms, n-pentyl alcohol or n-heptyl alcohol and an even aliphatic carboxylic acid having 10 to 16 carbon atoms. Aliphatic ester compounds having a total carbon number of 17 to 23 obtained from an acid are also effective.
Specifically, n-pentadecyl acetate, n-tridecyl butyrate, n-pentadecyl butyrate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caprylate, n-undecyl caprylate, N-Tridecyl caprylate, n-pentadecyl caprylate, n-heptyl capricate, n-nonyl caprice, n-undecyl caprice, n-tridecyl caprice, n-pentadecyl caprice, n-pentyl laurate, lauric acid n-heptyl, n-nonyl laurate, n-undecyl laurate, n-tridecyl laurate, n-pentadecyl laurate, n-pentyl myristate, n-heptyl myristate, n-nonyl myristate, n-myristate Undecyl, n-tridecyl myristate, n-pentadecyl myristate, n-pentyl palmitate, n-heptyl palmitate, n-nonyl palmitate, n-undecyl palmitate, n-tridecyl palmitate, n-pentadecyl palmitate, N-nonyl stearate, n-undecyl stearate, n-tridecyl stearate, n-pentadecyl stearate, n-nonyl eikosanoate, n-undersi eikosanoate, n-tridecyl eikosanoate, n-pentadecyl eikosanoate, behenic acid Examples thereof include n-nonyl, n-undecyl behenate, n-tridecyl behenate, n-pentadecyl behenate and the like.

As the ketones, aliphatic ketones having a total carbon number of 10 or more are effective, and 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, lauron, stearone and the like.
Furthermore, arylalkylketones having a total carbon number of 12 to 24, such as n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradeca. Nophenone, 4-n-dodecaacetophenone, n-tridecanophenone, 4-n-undecanoacetophenone, n-laurofenone, 4-n-decanoacetophenone, n-undecanophenone, 4-n-nonylacetophenone, n-decanophenone, 4-n-octylacetophenone, n-nonanophenone, 4-n-heptylacetophenone, n-octanophenone, 4-n-hexylacetophenone, 4-n-cyclohexylacetophenone, 4-tert-butylpropiophenone , N-Heptaphenone, 4-n-pentylacetophenone, cyclohexylphenylketone, benzyl-n-butylketone, 4-n-butylacetophenone, n-hexanophenone, 4-isobutylacetophenone, 1-acetonaphthone, 2-acetonafton, cyclopentylphenyl Examples include ketones.

As ethers, aliphatic ethers having a total carbon number of 10 or more are effective, and dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecyl ether, diundecyl ether, zidodecyl ether, and ditri Decyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, dioctadecyl ether, decanediol dimethyl ether, undecanediol dimethyl ether, dodecanediol dimethyl ether, tridecanediol dimethyl ether, decanediol diethyl ether, undecanediol diethyl ether, etc. Can be mentioned.

Examples of acid amides include acetamide, propionic acid amide, butyric acid amide, caproic acid amide, capric acid amide, capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and oleic acid amide. , Elcaic acid amide, benzamide, caproic acid anilide, capric acid anilide, capric acid anilide, laurate anilide, myristic acid anilide, palmitate anilide, stearate anilide, behenic acid anilide, oleic acid anilide, erucate anilide, caproic acid N -Methylamide, capric acid N-methylamide, capric acid N-methylamide, lauric acid N-methylamide, myristic acid N-methylamide, palmitic acid N-methylamide, stearate N-methylamide, behenic acid N-methylamide, oleic acid N-methylamide , Elcaic 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, palmitin Acid N-butylamide, stearate N-butylamide, oleic acid N-butylamide, lauric acid N-octylamide, myristic acid N-octylamide, palmitic acid N-octylamide, steaic acid N-octylamide, oleic acid N-octylamide. Amide, 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, Trimyristic acid amide, Tripalmitic acid amide, Tristea acid amide, Trioleic acid amide, Succinic acid amide, Adipic acid amide, Glutamic acid amide, Malonic acid amide, Azelin 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, glutaru Acid N-ethylamide, malonic acid N-ethylamide, azelaic acid N-ethylamide, succinic acid N-butylamide, adipic acid N- Examples thereof include butylamide, glutaric acid N-butylamide, malonic acid N-butylamide, adipic acid N-octylamide, and adipic acid N-dodecylamide.

〔式中、Ｒ_１は水素原子又はメチル基を示し、ｍは０～２の整数を示し、Ｘ_１、Ｘ_２のいずれか一方は－（ＣＨ_２）_ｎＯＣＯＲ_２又は－（ＣＨ_２）_ｎＣＯＯＲ_２、他方は水素原子を示し、ｎは０～２の整数を示し、Ｒ_２は炭素数４以上のアルキル基又はアルケニル基を示し、Ｙ_１及びＹ_２は水素原子、炭素数１～４のアルキル基、メトキシ基、又は、ハロゲンを示し、ｒ及びｐは１～３の整数を示す。〕
前記式（１）で示される化合物のうち、Ｒ_１が水素原子の場合、より広いヒステリシス幅を有する可逆熱変色性組成物が得られるため好適であり、更にＲ_１が水素原子であり、且つ、ｍが０の場合がより好適である。
なお、式（１）で示される化合物のうち、より好ましくは下記一般式（３）で示される化合物が用いられる。

式中のＲは炭素数８以上のアルキル基又はアルケニル基を示すが、好ましくは炭素数１０～２４のアルキル基、更に好ましくは炭素数１２～２２のアルキル基である。
前記化合物として具体的には、オクタン酸－４－ベンジルオキシフェニルエチル、ノナン酸－４－ベンジルオキシフェニルエチル、デカン酸－４－ベンジルオキシフェニルエチル、ウンデカン酸－４－ベンジルオキシフェニルエチル、ドデカン酸－４－ベンジルオキシフェニルエチル、トリデカン酸－４－ベンジルオキシフェニルエチル、テトラデカン酸－４－ベンジルオキシフェニルエチル、ペンタデカン酸－４－ベンジルオキシフェニルエチル、ヘキサデカン酸－４－ベンジルオキシフェニルエチル、ヘプタデカン酸－４－ベンジルオキシフェニルエチル、オクタデカン酸－４－ベンジルオキシフェニルエチルを例示できる。 Further, as the component (c), a compound represented by the following general formula (2) can also be used.

[In the formula, R ₁ indicates a hydrogen atom or a methyl group, m indicates an integer of 0 to 2, and either X ₁ or X ₂ is-(CH ₂ ) _n OCOR ₂ or-(CH ₂ ) _n . COOR ₂ indicates a hydrogen atom, n indicates an integer of 0 to 2, R ₂ indicates an alkyl group or an alkenyl group having 4 or more carbon atoms, Y ₁ and Y ₂ indicate a hydrogen atom and 1 to 4 carbon atoms. Represents an alkyl group, a methoxy group, or a halogen, and r and p represent integers of 1 to 3. ]
Among the compounds represented by the above formula (1), when R ₁ is a hydrogen atom, it is suitable because a reversible thermochromic composition having a wider hysteresis width can be obtained, and further, R ₁ is a hydrogen atom and , M is more preferably 0.
Of the compounds represented by the formula (1), the compound represented by the following general formula (3) is more preferably used.

R in the formula represents an alkyl group or an alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, and more preferably an alkyl group having 12 to 22 carbon atoms.
Specifically, the compound includes -4-benzyloxyphenylethyl octanoic acid, -4-benzyloxyphenylethyl nonanoate, -4-benzyloxyphenylethyl decanoate, -4-benzyloxyphenylethyl undecanoate, and dodecanoic acid. -4-benzyloxyphenylethyl, 4-benzyloxyphenylethyl tridecanoate, -4-benzyloxyphenylethyl tetradecanoate, -4-benzyloxyphenylethyl pentadecanoic acid, -4-benzyloxyphenylethyl hexadecanoic acid, heptadecanoic acid Examples thereof include -4-benzyloxyphenylethyl and -4-benzyloxyphenylethyl octadecanoic acid.

（式中、Ｒは炭素数８以上のアルキル基又はアルケニル基を示し、ｍ及びｎはそれぞれ１～３の整数を示し、Ｘ及びＹはそれぞれ水素原子、炭素数１～４のアルキル基、炭素数１～４のアルコキシ基、ハロゲンを示す。）
前記化合物として具体的には、オクタン酸１,１－ジフェニルメチル、ノナン酸１,１－ジフェニルメチル、デカン酸１,１－ジフェニルメチル、ウンデカン酸１,１－ジフェニルメチル、ドデカン酸１,１－ジフェニルメチル、トリデカン酸１,１－ジフェニルメチル、テトラデカン酸１,１－ジフェニルメチル、ペンタデカン酸１,１－ジフェニルメチル、ヘキサデカン酸１,１－ジフェニルメチル、ヘプタデカン酸１,１－ジフェニルメチル、オクタデカン酸１,１－ジフェニルメチルを例示できる。 Further, as the component (c), a compound represented by the following general formula (4) can also be used.

(In the formula, R represents an alkyl group or an alkoxy group having 8 or more carbon atoms, m and n represent integers of 1 to 3, respectively, and X and Y represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and carbon, respectively. Indicates an alkoxy group of numbers 1 to 4 and a halogen.)
Specifically, the compounds include octanoic acid 1,1-diphenylmethyl, nonanoic acid 1,1-diphenylmethyl, decanoic acid 1,1-diphenylmethyl, undecanoic acid 1,1-diphenylmethyl, and dodecanoic acid 1,1-. Diphenylmethyl, tridecanoic acid 1,1-diphenylmethyl, tetradecanoic acid 1,1-diphenylmethyl, pentadecanoic acid 1,1-diphenylmethyl, hexadecanoic acid 1,1-diphenylmethyl, heptadecanoic acid 1,1-diphenylmethyl, octadecanoic acid 1,1-Diphenylmethyl can be exemplified.

（式中、Ｘは水素原子、炭素数１乃至４のアルキル基、メトキシ基、ハロゲン原子のいずれかを示し、ｍは１乃至３の整数を示し、ｎは１乃至２０の整数を示す。）
前記化合物としては、マロン酸と２－〔４－(４－クロロベンジルオキシ）フェニル）〕エタノールとのジエステル、こはく酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、こはく酸と２－〔４－(３－メチルベンジルオキシ）フェニル）〕エタノールとのジエステル、グルタル酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、グルタル酸と２－〔４－(４－クロロベンジルオキシ）フェニル）〕エタノールとのジエステル、アジピン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、ピメリン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、スベリン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、スベリン酸と２－〔４－(３－メチルベンジルオキシ）フェニル）〕エタノールとのジエステル、スベリン酸と２－〔４－(４－クロロベンジルオキシ）フェニル）〕エタノールとのジエステル、スベリン酸と２－〔４－(２，４－ジクロロベンジルオキシ）フェニル）〕エタノールとのジエステル、アゼライン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、セバシン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、１，１０－デカンジカルボン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、１，１８-オクタデカンジカルボン酸と２－（４－ベンジルオキシフェニル）エタノールとのジエステル、１，１８-オクタデカンジカルボン酸と２－〔４－(２－メチルベンジルオキシ）フェニル）〕エタノールとのジエステルを例示できる。 Further, as the component (c), a compound represented by the following general formula (5) can also be used.

(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.)
Examples of the compound include a diester of malonic acid and 2- [4- (4-chlorobenzyloxy) phenyl)] ethanol, a diester of succinic acid and 2- (4-benzyloxyphenyl) ethanol, and a diester of succinic acid and 2-. [4- (3-Methylbenzyloxy) phenyl)] Diester with ethanol, Diester with glutaric acid and 2- (4-benzyloxyphenyl) ethanol, Diester with glutaric acid 2- [4- (4-chlorobenzyloxy) Phenyl)] Diester with ethanol, diester with adipic acid and 2- (4-benzyloxyphenyl) ethanol, diester with pimelic acid and 2- (4-benzyloxyphenyl) ethanol, suberic acid and 2- (4-) Diester with benzyloxyphenyl) ethanol, diester with Sveric acid and 2- [4- (3-methylbenzyloxy) phenyl)] Diester with ethanol, Diester with Sveric acid and 2- [4- (4-chlorobenzyloxy) phenyl)] Diester with ethanol, diester with suberic acid and 2- [4- (2,4-dichlorobenzyloxy) phenyl)] ethanol, diester with azelaic acid and 2- (4-benzyloxyphenyl) ethanol, with sebacic acid Diester with 2- (4-benzyloxyphenyl) ethanol, diester with 1,10-decandicarboxylic acid and 2- (4-benzyloxyphenyl) ethanol, 1,18-octadecanedicarboxylic acid and 2- (4-benzyl) Examples thereof include a diester with oxyphenyl) ethanol, and a diester with 1,18-octadecanedicarboxylic acid and 2- [4- (2-methylbenzyloxy) phenyl)] ethanol.

（式中、Ｒは炭素数１乃至２１のアルキル基又はアルケニル基を示し、ｎは１乃至３の整数を示す。）
前記化合物としては、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとカプリン酸とのジエステル、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとウンデカン酸とのジエステル、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとラウリン酸とのジエステル、１，３－ビス（２－ヒドロキシエトキシ）ベンゼンとミリスチン酸とのジエステル、１，４－ビス（ヒドロキシメトキシ）ベンゼンと酪酸とのジエステル、１，４－ビス（ヒドロキシメトキシ）ベンゼンとイソ吉草酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンと酢酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとプロピオン酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンと吉草酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとカプロン酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとカプリル酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとカプリン酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとラウリン酸とのジエステル、１，４－ビス（２－ヒドロキシエトキシ）ベンゼンとミリスチン酸とのジエステルを例示できる。 Further, as the component (c), a compound represented by the following general formula (6) can also be used.

(In the formula, R represents an alkyl group or an alkenyl group having 1 to 21 carbon atoms, and n represents an integer of 1 to 3).
Examples of the compound include a diester of 1,3-bis (2-hydroxyethoxy) benzene and capric acid, a diester of 1,3-bis (2-hydroxyethoxy) benzene and undecanoic acid, and 1,3-bis (2). -Diester of hydroxyethoxy) benzene and lauric acid, diester of 1,3-bis (2-hydroxyethoxy) benzene and myristic acid, diester of 1,4-bis (hydroxymethoxy) benzene and butyric acid, 1,4 -Diester of bis (hydroxymethoxy) benzene and isovaleric acid, diester of 1,4-bis (2-hydroxyethoxy) benzene and acetic acid, 1,4-bis (2-hydroxyethoxy) benzene and propionic acid Diester, diester of 1,4-bis (2-hydroxyethoxy) benzene and valerate, diester of 1,4-bis (2-hydroxyethoxy) benzene and caproic acid, 1,4-bis (2-hydroxyethoxy) ) Diester of benzene and capric acid, Diester of 1,4-bis (2-hydroxyethoxy) benzene and capric acid, Diester of 1,4-bis (2-hydroxyethoxy) benzene and lauric acid, 1,4 An example is an example of a diester of bis (2-hydroxyethoxy) benzene and myristic acid.

（式中、Ｘは水素原子、炭素数１乃至４のアルキル基、炭素数１乃至４のアルコキシ基、ハロゲン原子のいずれかを示し、ｍは１乃至３の整数を示し、ｎは１乃至２０の整数を示す。）
前記化合物としては、こはく酸と２－フェノキシエタノールとのジエステル、スベリン酸と２－フェノキシエタノールとのジエステル、セバシン酸と２－フェノキシエタノールとのジエステル、１，１０-デカンジカルボン酸と２－フェノキシエタノールとのジエステル、１，１８-オクタデカンジカルボン酸と２－フェノキシエタノールとのジエステルを例示できる。 Further, as the component (c), a compound represented by the following general formula (7) can also be used.

(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 1 to 20. Indicates an integer of.)
Examples of the compound include a diester of succinic acid and 2-phenoxyethanol, a diester of suberic acid and 2-phenoxyethanol, a diester of sebacic acid and 2-phenoxyethanol, and a diester of 1,10-decandycarboxylic acid and 2-phenoxyethanol. Examples of the diester of 1,18-octadecanedicarboxylic acid and 2-phenoxyethanol can be exemplified.

（式中、Ｒは炭素数４乃至２２のアルキル基、シクロアルキルアルキル基、シクロアルキル基、炭素数４乃至２２のアルケニル基のいずれかを示し、Ｘは水素原子、炭素数１乃至４のアルキル基、炭素数１乃至４のアルコキシ基、ハロゲン原子のいずれかを示し、ｎは０又は１を示す。）
前記化合物としては、４－フェニル安息香酸デシル、４－フェニル安息香酸ラウリル、４－フェニル安息香酸ミリスチル、４－フェニル安息香酸シクロヘキシルエチル、４－ビフェニル酢酸オクチル、４－ビフェニル酢酸ノニル、４－ビフェニル酢酸デシル、４－ビフェニル酢酸ラウリル、４－ビフェニル酢酸ミリスチル、４－ビフェニル酢酸トリデシル、４－ビフェニル酢酸ペンタデシル、４－ビフェニル酢酸セチル、４－ビフェニル酢酸シクロペンチル、４－ビフェニル酢酸シクロヘキシルメチル、４－ビフェニル酢酸ヘキシル、４－ビフェニル酢酸シクロヘキシルメチルを例示できる。 Further, as the component (c), a compound represented by the following general formula (8) can also be used.

(In the formula, R represents any of an alkyl group having 4 to 22 carbon atoms, a cycloalkylalkyl group, a cycloalkyl group, and an alkoxy group having 4 to 22 carbon atoms, and X is a hydrogen atom and an alkyl having 1 to 4 carbon atoms. A group, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, where n indicates 0 or 1).
Examples of the compound include decyl 4-phenylbenzoate, lauryl 4-phenylbenzoate, myristyl 4-phenylbenzoate, cyclohexylethyl 4-phenylbenzoate, octyl 4-biphenylacetate, nonyl 4-biphenylacetate, and 4-biphenylacetic acid. 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-Cyclohexylmethyl biphenylacetate can be exemplified.

（式中、Ｒは炭素数３乃至１８のアルキル基、炭素数３乃至１８の脂肪族アシル基のいずれかを示し、Ｘは水素原子、炭素数１乃至３のアルキル基、炭素数１又は２のアルコキシ基、ハロゲン原子のいずれかを示し、Ｙは水素原子、メチル基のいずれかを示し、Ｚは水素原子、炭素数１乃至４のアルキル基、炭素数１又は２のアルコキシ基、ハロゲン原子のいずれかを示す。）
前記化合物としては、４－ブトキシ安息香酸フェノキシエチル、４－ペンチルオキシ安息香酸フェノキシエチル、４－テトラデシルオキシ安息香酸フェノキシエチル、４－ヒドロキシ安息香酸フェノキシエチルとドデカン酸とのエステル、バニリン酸フェノキシエチルのドデシルエーテルを例示できる。 Further, as the component (c), a compound represented by the following general formula (9) can also be used.

(In the formula, R indicates any of an alkyl group having 3 to 18 carbon atoms and an aliphatic acyl group having 3 to 18 carbon atoms, and X is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, and 1 or 2 carbon atoms. Indicates either an alkoxy group or a halogen atom, Y indicates either a hydrogen atom or a methyl group, Z is 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. Indicates one of.)
Examples of the compound include phenoxyethyl 4-butoxybenzoate, phenoxyethyl 4-pentyloxybenzoate, phenoxyethyl 4-tetradecyloxybenzoate, an ester of phenoxyethyl 4-hydroxybenzoate and dodecanoic acid, and phenoxyethyl vanillate. Dodecyl ether can be exemplified.

（式中、Ｒは炭素数４乃至２２のアルキル基、炭素数４乃至２２のアルケニル基、シクロアルキルアルキル基、シクロアルキル基のいずれかを示し、Ｘは水素原子、アルキル基、アルコキシ基、ハロゲン原子のいずれかを示し、Ｙは水素原子、アルキル基、アルコキシ基、ハロゲン原子のいずれかを示し、ｎは０又は１を示す。）
前記化合物としては、ｐ－ヒドロキシ安息香酸オクチルの安息香酸エステル、ｐ－ヒドロキシ安息香酸デシルの安息香酸エステル、ｐ－ヒドロキシ安息香酸ヘプチルのｐ－メトキシ安息香酸エステル、ｐ－ヒドロキシ安息香酸ドデシルのo-メトキシ安息香酸エステル、ｐ－ヒドロキシ安息香酸シクロヘキシルメチルの安息香酸エステルを例示できる。 Further, as the component (c), a compound represented by the following general formula (10) can also be used.

(In the formula, R indicates any 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, and X is a hydrogen atom, an alkyl group, an alkoxy group, and a halogen. Any of the atoms, Y indicates any of a hydrogen atom, an alkyl group, an alkoxy group, and a halogen atom, and n indicates 0 or 1).
Examples of the compound include an benzoic acid ester of octyl p-hydroxybenzoate, a benzoic acid ester of decyl p-hydroxybenzoate, a p-methoxybenzoic acid ester of heptyl p-hydroxybenzoate, and o- of dodecyl p-hydroxybenzoate. Examples thereof include methoxybenzoic acid esters and benzoic acid esters of p-hydroxybenzoate cyclohexylmethyl.

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

(In the formula, (in the formula, R is an alkyl group having 3 to 18 carbon atoms, a cycloalkylalkyl group having 6 to 11 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, or an alkoxy group having 3 to 18 carbon atoms. X indicates a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a halogen atom, and Y indicates a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or methoxy. Indicates a group, an ethoxy group, or a halogen atom.)
Examples of the compound include phenoxyethyl ether of nonyl p-hydroxybenzoate, phenoxyethyl ether of decyl p-hydroxybenzoate, phenoxyethyl ether of undecyl p-hydroxybenzoate, and phenoxyethyl ether of dodecyl vanillate.

Further, as the electron-accepting compound, a specific alkoxyphenol compound having a linear or side-chain alkyl group having 3 to 18 carbon atoms may be used (Japanese Patent Laid-Open No. 11-129623, JP-A-11-5973), or a specific one. A hydroxybenzoic acid ester (Japanese Patent Laid-Open No. 2001-105732) or a gallic acid ester (Japanese Patent Laid-Open No. 51-44706, Japanese Patent Application Laid-Open No. 2003-253149) is used for heating and coloring (coloring by heating, A reversible thermochromic composition (which is decolorized by cooling) and a reversible thermochromic microcapsule pigment (reversible thermochromic pigment) containing the same can also be applied (see FIG. 3).

The reversible thermochromic composition of the present invention is a compatible compound containing the above-mentioned components (a), (b) and (c) as essential components, and the ratio of each component is the concentration, discoloration temperature, discoloration morphology and each component. In general, the component ratio at which the desired characteristics can be obtained is 0.1 to 100, preferably 0.1 to 50, and more preferably 0.1 to 50 for the component (b) with respect to the component 1. Is in the range of 0.5 to 20, (c) component 5 to 200, preferably 5 to 100, and more preferably 10 to 100 (all of the above ratios are parts by mass).

Further, various light stabilizers can be added as needed.
The light stabilizer is contained in order to prevent photodegradation of the reversible thermochromic composition composed of the components (a), (b) and (c), and is 0.3 with respect to 1% by mass of the component (a). It is contained in an amount of about 24% by mass, preferably 0.3 to 16% by mass. Further, among the light stabilizers, the ultraviolet absorber effectively blocks the ultraviolet rays contained in sunlight and the like, and prevents photodegradation caused by the excited state due to the optical reaction of the component (a). Further, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers and the like suppress the oxidation reaction by light.
The light stabilizer may be used alone or in combination of two or more.

Among the light stabilizers, the ultraviolet absorbing and collecting agent is
2,4-Hydroxybenzophenone 2-Hydroxy-4-methoxybenzophenone 2,2'-dihydroxy-4,4'-dimethoxybenzophenone 2,2', 4,4'-tetrahydroxybenzophenone 2-hydroxy-4-methoxybenzophenone- 5-sulfonic acid 2-hydroxy-4-octoxybenzophenone bis- (2-methoxy-4-hydroxy-5-benzoylphenyl) -methane 2- [2'-hydroxy-3'-5'-di-t-amyl Phenyl] -benzophenone 2-hydroxy-4-dodecyloxy-benzophenone [trade name: Seasorb 103, manufactured by Cipro Kasei Co., Ltd.]
2-Hydroxy-4-octadecyloxybenzophenone 2,2'-dihydroxy-4-methoxybenzophenone 2-hydroxy-4-benzyloxybenzophenone 2- [2'-hydroxy-3'-5'-di-t-amylphenyl] -A benzophenone-based ultraviolet absorber such as benzophenone.
Phenyl salicylate Para-t-butyl phenyl salicylic acid Para-octyl phenyl salicylate 2-4-di-t-butyl phenyl-4-hydroxybenzoate 1-hydroxybenzoate 1-hydroxy-3-t-butyl-benzoate 1-hydroxy-3-t -Octylbenzoate Resocinol Monobenzoate and other salicylic acid-based UV absorbers.

Ethyl-2-cyano-3,3'-diphenylacrylate 2-Ethylhexyl-2-cyano-3,3'-Diphenylacrylate 2-Ethylhexyl-2-cyano-3-phenylacrylate A cyanoacrylate-based UV absorber such as thinner.
2- [5-t-Butyl-2-hydroxyphenyl] -benzotriazole [Product name: Tinubin-PS, manufactured by Ciba Geigy]
2- [5-Methyl-2-hydroxyphenyl] -benzotriazole 2- [2, hydroxy-3,5-bis (a, a-dimethylbenzyl) phenyl] -2H benzotriazole 2- [3,5-di- t-Butyl-2-hydroxyphenyl] -benzotriazole 2- [3-t-butyl-5-methyl-2-hydroxyphenyl] -5-chlorobenzotriazole 2- [3,5-di-t-butyl-2] -Hydroxyphenyl] -5-chlorobenzotriazole 2- [3,5-di-t-amyl-2-hydroxyphenyl] -benzotriazole [trade name: Tinubin 328, manufactured by Ciba Geigy]
Methyl-3- [3-t-butyl-5- (2H-benzotriazole-2-yl) -4-hydroxyphenyl] propionate-polyethylene glycol molecular weight 300 [trade name: Tinubin 1130, manufactured by Ciba Geigy]
2- [3-Dodecyl-5-methyl-2-hydroxyphenyl] benzotriazole Methyl-3- [3- (2H-benzotriazole-2-yl) -5-t-butyl-4-hydroxyphenyl] propionate-polyethylene Glycol molecular weight 300
2- [3-t-butyl-5-propyloctylate-2-hydroxyphenyl] -5-chlorobenzotriazole 2- [2-hydroxyphenyl-3,5-di- (1,1'-dimethylbenzyl) phenyl ] -2H-Benzotriazole 2- [2-Hydroxy-5-t-octylphenyl] -2H-benzotriazole 2- [3-t-butyl-5-octyloxycarbonylethyl-2-hydroxyphenyl] -benzotriazole [ Product name: Chinubin 384, manufactured by Ciba Geigy Co., Ltd.]
2- [2-Hydroxy-5-tetraoctylphenyl] -benzotriazole 2- [2-Hydroxy-4-octoxy-phenyl] -benzotriazole 2- [2'-hydroxy-3'-(3 "4" 5 "" 6 "-Tetrahydrophthalimidemethyl) -5'-Methylphenyl] -Benzotriazole 2- (2-Hydroxy-5-t-butylphenyl) -Benzotriazole-based ultraviolet absorbers such as benzotriazole.
Ethandiamid-N- (2-ethoxyphenyl) -N'-(4-isododecylphenyl)
2,2,4,4-Tetramethyl-20- (β-lauryl-oxycarbonyl) -ethyl-7-oxa-3,20-diazodispyro (5,1,11,2) heneic acid-21-one, etc. Oxalic acid anilide UV absorber.

2,4-Diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine,
2,4-Diphenyl-6- (2-hydroxy-4-ethoxyphenyl) -1,3,5-triazine,
2,4-Diphenyl-6- (2-Hydroxy-4-propoxyphenyl) -1,3,5-triazine,
2,4-Diphenyl-6- (2-Hydroxy-4-butoxyphenyl) -1,3,5-triazine,
2,4-Diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine,
2,4-Diphenyl-6- (2-Hydroxy-4-pentoxyphenyl) -1,3,5-triazine,
2,4-Diphenyl-6- (2-Hydroxy-4-octyloxyphenyl) -1,3,5-triazine,
2,4-Diphenyl-6- (2-hydroxy-4-dodecyloxyphenyl) -1,3,5-triazine,
2,4-Diphenyl-6- (2-hydroxy-4-benzyloxyphenyl) -1,3,5-triazine,
2,4-Diphenyl-6- (2-hydroxy-4- (2-butoxyethoxy) phenyl) -1,3,5-triazine,
2,4-Di-p-Trail-6- (2-Hydroxy-4-methoxyphenyl) -1,3,5-triazine,
2,4-Di-p-Trail-6- (2-Hydroxy-4-propoxyphenyl) -1,3,5-triazine,
2,4-Di-p-Trail-6- (2-Hydroxy-4-butoxyphenyl) -1,3,5-triazine,
2,4-Di-p-Trail-6- (2-Hydroxy-4-hexyloxyphenyl) -1,3,5-triazine,
2,4-Di-p-Trail-6- (2-Hydroxy-4-pentoxyphenyl) -1,3,5-triazine,
2,4-Di-p-Trail-6- (2-Hydroxy-4-octyloxyphenyl) -1,3,5-triazine,
2,4-di-p-trail-6- (2-hydroxy-4-benzyloxyphenyl) -1,3,5-triazine,
2,4-Di-p-Trail-6- (2-Hydroxy-4- (2-hexyloxyethoxy) phenyl) -1,3,5-triazine,
2- [4-[(2-Hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine,
2- [4-[(2-Hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine,
2- [4-[(2-Hydroxy-3- (2'-ethyl) hexyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5- Triazine,
2,4-bis (2-hydroxy-4-butyloxyphenyl) -6- (2,4-bis-butyloxyphenyl) -1,3,5-triazine,
2- (2-Hydroxy-4-[(1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine and other triazine-based UV absorbers are mentioned. Be done.

As an antioxidant (anti-aging agent),
Dimethyl-1- (2, hydroxyethyl) succinate-4-hydroxy-2,2,6,6, tetramethylpiperidine polycondensate poly ["6- (1,1,3,3-tetramethylbutyl) imino -1,3,5-triazine-2-4-syl "" (2,2,6,6-tetramethyl-4-piperidyl) imino "]
2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentapetyl-4-piperidyl)
N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentapetyl-4-piperidyl) amino] -6-chloro- 1,3,5-triazine condensate bis [1,2,2,6,6-pentamethyl-4-piperidylsebacic acid]
4-Benzoyloxy-2,2,6,6-tetramethylpiperidine bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate 8-acetyl-3-dodecyl-7,7,9,9- A hindered amine-based antioxidant such as tetramethyl-1,3,8-triazaspiro "4,5] decane-2,4-dione.

2,6, di-t-butyl-4-methylphenol 2-t-butyl-4-methoxyphenol 2,6-di-t-butyl-4-ethylphenol octadecyl-3- (3,5-di-t) -Butyl-4-hydroxyphenyl) propionate 2,2-methylenebis (4-methyl-6-t-butylphenol)
4,4-thiobis (2-methyl-6-t-butylphenol)
2,2-thiobis (4-methyl-6-t-butylphenol)
4,4-Butylidenebis (3-methyl-6-t-butylphenol)
3,9-bis [1,1-dimethyl-2- [β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] 2,4,8,10-tetraoxaspiro [ 5,5] -Undecane 1,1,3-Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane 1,3,5-trimethyl-2,4,6-Tris (3,5- Di-t-butyl-4-hydroxybenzyl) benzene tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] -methane 2,2-ethylenebis (4,6-di) -T-Butylphenol)
Bis [3,3'-bis- (4'-hydroxy-3'-t-butylphenyl) butyl acid] -glycol ester 1,3,5-tris (3'5'-di-t-butyl-4) ′ -Hydroxybenzyl) -S-triazine-2,4,6- (1H, 3H, 5H) -triontocophenol 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethyl) Benzyl) isocyanurate pentaerythritol tetrakis (3-laurylthiopropionate)
Triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate]
1,6-Hexadiol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]
2,2-thioethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]
N, N'-hexamethylenebis (3,5-t-butyl-4-hydroxy-hydrocinnamamide)
Tris- (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate 2,2,4-trimethyl-1,2-hydroquinone Stylatephenol 2,5-di-t-butyl-hydroquinone bis ( 2,2,6,6-tetramethyl-4, piperidyl) Phenolic antioxidants such as sevacate.

Dilauryl-3,3'-thiodipropionate Dimyristyl-3,3'-thiodipropionate Distearyl-3,3'-thiodipropionate Sulfur-based antioxidants such as stearylthiopropylamide.

Tris (2,4-di-t-butylphenyl) phosphite bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite 3,5-di-t-butyl-4-hydroxy-benzylphospha Nate-diethylester Triphenylphosphite Diphenylisodecylphosphite Phenylisodecylphosphite 4,4'-Buchilidene-bis (3-methyl-6-t-butylphenylditridecyl) Phenylphosphite Octadecylphosphite Tris (nonylphenyl) Phosphite Diisodecylpentaerythritol Diphosphite 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9- Oxa-10-phosphaphenantren-10-oxide 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenantren Cyclic neopentatetraylbis (2,4-di-t-butylphenyl) phos Fight Cyclic Neopentanetetraylbis (2,6,-di-t-butyl-4-methylphenyl) Phenylphosphite 2,2-Methylenebis (4,6-Gt-butylphenyl) Octylphosphite 2,4- Examples thereof include phosphate-based antioxidants such as bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine octylated diphenylamine.

As a singlet oxygen quencher,
Examples thereof include carotins, pigments, amines, phenols, nickel complexes, sulfides and the like, for example, 1.4-diazabicyclo (2,2,2) octane (DABCO), β-carotene, 1.3-. Cyclohexadiene, 2-diethylaminomethylfuran, 2-phenylaminomethylfuran, 9-diethylaminomethylanthracene, 5-diethylaminomethyl-6-phenyl-3,4-dihydroxypyran, nickeldimethyldithiocarbamate, nickel3.5-di- t-butyl-4-hydroxybenzyl O-ethylphosphonate, nickel 3,5-di-t-butyl-4-hydroxybenzyl O-butylphosphonate, nickel [2.2'-thiobis (4-t-octylpheno) Lat)] (n-butylamine), nickel [2.2'-thio-bis (4-t-octylphenolate)] (2-ethylhexylamine), nickel bis [2.2'-thio-bis (4-t-thio-bis) t-octylphenolate)], nickel bis [2.2'-sulfon-bis (4-octylphenolate)], nickel bis [2-hydroxy-5-methoxyphenyl-Nn-butylaldoimin), nickel There are bis (dithiobenzyl), nickel bis (dithiobiacetyl) and the like.

As a superoxide anion quencher,
Examples thereof include a complex of superoxide dismutase, cobalt, and nickel.

Examples of the ozone quenching agent include 4,4'-thiobis (6-t-butyl-m-cresole), 2,4,6-tri-t-butylphenol, 1,4-diazabicyclo [2.2.2] octane, and the like. N-Phenyl-β-naphthylamine, α-tocopherol, 4,4'-methylene-bis (2,6-di-t-butylphenol), P, P'-diaminodiphenylmethane, 2,2'-methylene-bis (6) -T-butyl-P-cresol), N, N'-diphenyl-P-phenylenediamine, N, N'-diphenylethylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine and the like.

Although the reversible thermochromic composition can be applied as it is, it is preferably used as a reversible thermochromic microcapsule pigment encapsulated in microcapsules. This is because the reversible thermochromic composition can be kept in the same composition under various usage conditions and can exert the same action and effect.
The microencapsulation is a conventionally known interfacial polymerization method, inSitu polymerization method, in-liquid curing coating method, phase separation method from an aqueous solution, phase separation method from an organic solvent, melting dispersion cooling method, and suspension in air. There are a coating method, a spray drying method, etc., which are appropriately selected according to the application. Further, a secondary resin film may be further provided on the surface of the microcapsules depending on the purpose to impart durability, or the surface characteristics may be modified for practical use.
By encapsulating in the microcapsules, a chemically and physically stable pigment can be formed, and a particle size in the range of 0.01 to 50 μm, preferably 0.1 to 30 μm, and more preferably 0.5 to 20 μm is practical. Meet the sex.
For the measurement of the average particle size, the particle area is determined using the image analysis type particle size distribution measurement software "MacView" manufactured by Mountech, and the projected area circle equivalent diameter (Heywood diameter) is calculated from the area of the particle area. It is a value calculated and measured as the average particle diameter of particles corresponding to equal volume spheres based on the value.
If the particle size of all or most of the particles exceeds 0.2 μm, it is equivalent to an equal volume sphere by the Coulter method using a particle size distribution measuring device (manufactured by Beckman Coulter Co., Ltd., product name: Multisizer 4e). It is also possible to measure as the average particle size of the particles of.

The microcapsule pigment is preferably in the range of inclusions / wall film = 7/1 to 1/1 (mass ratio), and when the ratio of the wall film is within the above range, the color density at the time of color development and It is possible to prevent a decrease in sharpness, and more preferably, inclusions / wall film = 6/1 to 1/1 (mass ratio).

The reversible thermochromic composition and the microcapsule pigment containing the same are dispersed in a vehicle containing water and / or an organic solvent and, if necessary, various additives, and are dispersed in a vehicle, such as screen printing, offset printing, process printing, gravure printing, and coater. , Printing ink used for tampo printing, brush coating, spray coating, electrostatic coating, electrodeposition coating, sink coating, roller coating, dip coating, ink for inkjet, UV curable ink, marking pen It can be used as a reversible thermochromic liquid composition such as inks for writing tools or coating tools for ball pens, perennial brushes, brush pens, paints, cosmetics, coloring liquids for fibers, and the like.
Various additives can be added to the liquid composition, and a resin, a cross-linking agent, a curing agent, a desiccant, a plasticizer, a viscosity regulator, a dispersant, an ultraviolet absorber, an antioxidant, a light stabilizer, and a precipitation agent can be added. Examples thereof include inhibitor, smoothing agent, gelling agent, defoaming agent, matting agent, penetrant, pH adjuster, foaming agent, coupling agent, moisturizing agent, fungicide, preservative, rust preventive and the like.

Among them, examples of the writing instrument vehicle used for the writing instrument ink include an oil-based vehicle containing an organic solvent, or a water-based vehicle containing water and, if necessary, an organic solvent.
Examples of the organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, and ethylene glycol. Examples include monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, N-methyl-2-pyrrolidone and the like. Can be done.

Examples of the ink for writing tools include a shear-reducing viscosity ink containing a shear-reducing viscosity-imparting agent in a vehicle, and a cohesive ink containing a water-soluble polymer flocculant in a vehicle and suspending a pigment in a loosely aggregated state. be able to.
By adding the shear thinning agent, it is possible to suppress the aggregation and sedimentation of the pigment and also to suppress the bleeding of the handwriting, so that a good handwriting can be formed.
Further, when the writing instrument filled with the ink is in the form of a ballpoint pen, ink leakage from the gap between the ball and the tip when not in use can be prevented, or ink backflow occurs when the writing tip is left facing upward (upright). Can be prevented.
Examples of the shear reducing viscosity imparting agent include xanthan gum, welan gum, succinoglycan (average molecular weight of about 1 to 8 million), which is an organic acid-modified heteropolysaccharide whose constituent monosaccharides are glucose and galactose, guar gum, locust bean gum and the like. Polymers with a molecular weight of 100,000 to 150,000 containing derivatives, hydroxyethyl cellulose, alginic acid alkyl esters, and methacrylic acid alkyl esters as the main components, and thickening with gelling ability extracted from seaweeds such as glucomannan, agar, and caragenin. Polysaccharides, benzylene sorbitol and benzylene xylitol or derivatives thereof, crosslinkable acrylic acid polymers, inorganic fine particles, polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxypropylene alkyl Nonionic surfactants having an HLB value of 8 to 12, such as ethers, polyoxyethylene alkyl phenyl ethers, and fatty acid amides, and salts of dialkyl or dialkenyl sulfosuccinic acid. Examples thereof include a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin.

Examples of the water-soluble polymer flocculant include polyvinylpyrrolidone, polyethylene oxide, and water-soluble polysaccharides.
Examples of the water-soluble polysaccharide include traganth gum, guar gum, pullulan, cyclodextrin, and water-soluble cellulose derivative, and specific examples of the water-soluble cellulose derivative include methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methyl cellulose, and hydroxypropyl methyl cellulose. And so on.

By using a comb-shaped polymer dispersant having a carboxyl group in the side chain and an organic nitrogen-sulfur compound in combination with the polymer flocculant, the dispersibility of loose aggregates of the microcapsule pigment by the polymer flocculant is improved. be able to.
The comb-type polymer dispersant having a carboxyl group in the side chain is not particularly limited as long as it is a comb-type polymer compound having a plurality of carboxyl groups in the side chain, but the side chain has a plurality of carboxyl groups. Acrylic polymer compounds having a

The organic nitrogen-sulfur compound further suppresses the precipitation of the microcapsule pigment due to vibration when the ink composition is filled in a writing instrument and put into practical use.
This further improves the dispersibility in which the loose aggregates of the microcapsule pigment are dispersed by the comb-shaped polymer dispersant having a carboxyl group in the side chain.
As the organic nitrogen sulfur compound, a compound selected from a thiazole-based compound, an isothiazole-based compound, a benzothiazole-based compound, and a benzoisothiazole-based compound is used.
Specifically, as the organic nitrogen sulfur compound, 2- (4-thiazolin) -benzimidazole (TBZ), 2- (thiocyanatemethylthio) -1,3-benzothiazole (TCMTB), 2-methyl-4-isothiazolin- One or more compounds selected from 3-one, 5-chloro-2-methyl-4-isothiazolin-3-one are used, preferably 2- (4-thiazolin) -benzimidazole (TBZ), 2 One or more compounds selected from -methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one are used.
Examples of the organic nitrogen-sulfur compound include Permachem Asia Co., Ltd., trade names: Topside 88, 133, 170, 220, 288, 300, 400, 500, 600, 700Z. Examples thereof include 800, 950, manufactured by Hokuko Sangyo Co., Ltd., trade names: Hokuster HP, E50A, Hokuside P200, 6500, 7400, MC, 369, and R-150.
The mass ratio of the comb-shaped polymer dispersant having a carboxyl group in the side chain to the organic nitrogen-sulfur compound is 1: 1 to 1:10, preferably 1: 1 to 1: 5, which satisfies the above range. This makes it possible to sufficiently exhibit the dispersibility of loose aggregates of the microcapsule pigment and the suppression of sedimentation of the microcapsule pigment due to vibration.

Further, when a water-soluble resin applied to impart adhesion and viscosity of the brush to the paper surface is added, the ink containing the comb-shaped polymer dispersant having a carboxyl group in the side chain and the organic nitrogen-sulfur compound described above is added. The function of increasing the stability of the microcapsule pigment is further improved.
Examples of the water-soluble resin include alkyd resin, acrylic resin, styrene maleic acid copolymer, cellulose derivative, polyvinylpyrrolidone, polyvinyl alcohol, dextrin and the like, and polyvinyl alcohol is preferably used.
Further, the polyvinyl alcohol is more preferably used because the partially saponified polyvinyl alcohol having a saponification degree of 70 to 89 mol% is highly soluble even in the acidic region of the ink.
The amount of the water-soluble resin added is in the range of 0.3 to 3.0% by mass, preferably 0.5 to 1.5% by mass, in the ink.

When the ink is filled in a ball pen and used, a higher fatty acid such as oleic acid, a nonionic surfactant having a long-chain alkyl group, a polyether-modified silicone oil, a thioarophosphoric acid tri (alkoxycarbonylmethyl ester), or the like. Phosphoric acid triesters such as thio-phosphoric acid tri (alkoxycarbonylethyl ester), phosphoric acid monoesters of polyoxyethylene alkyl ethers or polyoxyethylene alkylaryl ethers, phosphorus of polyoxyethylene alkyl ethers or polyoxyethylene alkylaryl ethers. It is preferable to add a phosphoric acid diester or a lubricant such as a metal salt thereof, an ammonium salt, an amine salt or an alkanol amine salt to prevent wear of the ball receiving seat.

In addition, if necessary, resins such as acrylic resin, styrene maleic acid copolymer, cellulose derivative, polyvinylpyrrolidone, polyvinyl alcohol, and dextrin can be added to impart stickiness and viscosity to the paper surface, and sodium carbonate and sodium phosphate can be added. , Inorganic salts such as sodium acetate, pH adjusters such as organic basic compounds such as water-soluble amine compounds, benzotriazole, tolyltriazole, dicyclohexylammonium nitrate, diisopropylammonium nitrate, rust preventives such as saponin, coal acid, 1,2-Benziazolin 3-one sodium salt, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, etc. Preservatives or antiseptics, urea, nonionic surfactants, reduced or non-reduced starch hydrolysates, oligosaccharides such as trehalose, sucrose, cyclodextrin, glucose, dextrin, sorbit, mannit, sodium pyrophosphate, etc. Wetting agents, defoaming agents, dispersants, fluorosurfactants and nonionic surfactants that improve the permeability of ink may be added.

It can contain a reversible thermochromic microcapsule pigment of preferably 5 to 40% by mass, more preferably 10 to 40% by mass, still more preferably 10 to 30% by mass with respect to the total mass of the ink. When the content of the microcapsule pigment is in the above range, a desired color development density can be achieved, and further deterioration of ink outflow can be prevented.

A ballpoint pen and a marking pen for accommodating the ink will be described.
When filling a ballpoint pen, the structure and shape of the ballpoint pen itself are not particularly limited. For example, the barrel has an ink storage tube filled with shear-reducing viscosity ink, and the ink storage tube has a ball at the tip. An example is a ballpoint pen that communicates with a ballpoint pen tip attached to the ink and has a liquid stopper for preventing backflow in close contact with the end face of the ink.
The ball pen tip will be described in more detail. A tip formed by holding a ball in a ball holding portion in which the vicinity of the tip of a metal pipe is pressed and deformed inward from an outer surface, or a metal material is cut by a drill or the like. A chip formed by holding a ball in a ball holding portion, a chip provided with a resin ball receiving seat inside a metal or plastic chip, or a ball held by the chip forward by a spring body. The urged one can be applied.
The ball is 0.3 to 2.0 mm, preferably 0.3 to 1.5 mm, more preferably 0.3 to 1.0 mm of cemented carbide, stainless steel, ruby, ceramic, resin, rubber or the like. A diameter of about the same can be applied.
As the ink accommodating tube for accommodating the ink, for example, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon, or a metal tubular body is used.
In addition to directly connecting the chip to the ink storage tube, the ink storage tube and the chip may be connected via a connecting member.
The ink storage tube may be in the form of a refill in which the refill is housed in a shaft tube made of resin, metal, or the like, or the shaft tube itself with a chip attached to the tip thereof is used as an ink storage body. Ink may be filled directly into the barrel.
Further, when the ink composition is housed in the infestation type ballpoint pen, the structure and shape of the infestation type ballpoint pen are not particularly limited, and the shaft is in a state where the writing tip portion provided on the ballpoint pen refill is exposed to the outside air. Any structure can be used as long as it is housed in a cylinder and the writing tip protrudes from the opening of the shaft cylinder by the operation of the retracting mechanism.
Examples of the operation method of the haunting mechanism include a knock type, a rotary type, and a slide type.
The knock type has a knock portion on the rear end portion of the shaft cylinder or the side surface of the shaft cylinder, and the ballpoint pen tip is retracted from the opening at the front end end of the shaft cylinder by pressing the knock portion, or a clip portion provided on the shaft cylinder. By pressing the ballpoint pen tip, a configuration in which the ballpoint pen tip appears and disappears from the opening at the front end of the barrel can be exemplified.
The rotary type can exemplify a configuration in which a rotating portion is provided at the rear portion of the barrel, and the ballpoint pen tip is retracted from the opening at the front end of the barrel by rotating the rotating portion.
The slide type has a slide portion on the side surface of the barrel, and the ballpoint pen tip can be retracted from the front end opening of the barrel by operating the slide, or the clip portion provided on the barrel can be slid. An example is an example of a configuration in which the ballpoint pen tip appears and disappears from the opening at the front end of the barrel.
The haunting type ballpoint pen is a composite type haunting ballpoint pen in which a plurality of ballpoint pen refills are housed in a shaft cylinder, and the writing tip of any of the ballpoint pen refills appears and disappears from the front end opening of the shaft cylinder by the operation of the hoisting mechanism. You may.

The rear end of the ink stored in the ink storage tube is filled with an ink backflow preventive body.
The ink backflow prevention body composition comprises a non-volatile liquid or a non-volatile liquid.
Specifically, vaseline, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Examples thereof include polyether-modified silicone oil and fatty acid-modified silicone oil, and one or more of them can be used in combination.
The non-volatile liquid and / or the non-volatile liquid is preferably thickened to a suitable viscosity by adding a thickener, and the thickener is silica whose surface is hydrophobically treated and the surface is methylated. Fine particle silica, aluminum silicate, swelling mica, clay-based thickeners such as bentonite and montmorillonite treated with hydrophobicity, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, trivendilidene sorbitol, Examples thereof include fatty acid amide, amide-modified polyethylene wax, hydrogenated castor oil, a dextrin-based compound such as fatty acid dextrin, and a cellulose-based compound.
Further, the liquid ink backflow preventive body and the solid ink backflow preventive body can be used in combination.

When the marking pen is filled, the structure and shape of the marking pen itself are not particularly limited. A marking pen made of a marking pen, which is formed by mounting a marking pen tip made of the same material directly or via a relay member on a shaft tube and impregnating the ink storage body of the marking pen in which the ink storage body and the tip are connected with a cohesive ink. An example is a marking pen in which a chip and an ink accommodating tube are arranged via a valve body that is opened by pressing the chip, and ink is directly accommodated in the ink accommodating tube.
The chip is a porous member of continuous ventilation holes selected from a conventional general-purpose pore ratio of about 30 to 70%, such as a resin processed body of a fiber, a fused processed body of a heat-meltable fiber, and a felt body. One end is processed into a shape suitable for the purpose such as a bullet shape, a rectangle shape, a chisel shape, etc. and put into practical use.
The ink occlusion body is formed by bundling crimped fibers in the longitudinal direction, and is incorporated in a covering body such as a plastic cylinder or a film to adjust the porosity to approximately 40 to 90%. Will be done.
Further, although a general-purpose pumping type can be used for the valve body, it is preferable that the valve body is set to a spring pressure that can be pressed and released by writing pressure.

Further, the form of the ballpoint pen or marking pen is not limited to the above-mentioned one, and a double-headed writing tool may be equipped with a tip having a different form or a pen tip for drawing out inks of different colors.

The handwriting obtained by writing on the writing surface using the writing instrument containing the writing instrument ink composition can be discolored by a heating tool or a cooling tool.
Examples of the heating tool include an energization heating discoloring tool equipped with a resistance heating element, a heating discoloring tool filled with hot water, and a hair dryer. However, a friction member is preferable as a means capable of discoloring by a simple method. Used.
As the friction member, an elastic body such as an elastomer or a plastic foam, which has a high elastic feeling and can generate appropriate friction at the time of rubbing to generate frictional heat, is suitable.
Although it is possible to rub the handwriting using an eraser, the above-mentioned friction member in which almost no eraser residue is generated is preferably used because the eraser residue is generated at the time of rubbing.
As the material of the friction member, a silicone resin, a SEBS resin (styrene ethylene butadiene styrene block copolymer), a polyester resin, or the like is used.
The friction member can be obtained by combining a writing instrument and a member (friction body) having an arbitrary shape, which is different from the writing instrument, and a writing instrument set can be obtained. However, by providing the friction member on the writing instrument, the portability is excellent.
In the case of a writing instrument provided with a cap, the place where the friction member is provided is not particularly limited, but for example, when the cap itself is formed of the friction member, the barrel itself is formed of the friction member, or a clip is provided. The clip itself can be formed of a friction member, or a friction member can be provided at the tip of the cap (top) or the rear end of the barrel (the part where the writing tip is not provided).
In the case of a haunting type writing instrument, the place where the friction member is provided is not particularly limited, but for example, the barrel itself may be formed of the friction member, or the clip itself may be formed of the friction member when the clip is provided. A friction member can be provided near the opening of the cylinder, the rear end of the cylinder (the part where the writing tip is not provided), or the knock portion.
Examples of the cooling tool include a cold-heat discoloring tool using a Pertier element, a cold-heat discoloring tool filled with a refrigerant such as cold water and ice pieces, and an application of a refrigerator or a freezer.

When the reversible thermochromic liquid composition is applied or printed, the material of the support is not specified and all are effective, and paper, synthetic paper, fiber, cloth, synthetic leather, leather, plastic, glass, and porcelain material. , Metal, wood, stone, etc. can be exemplified, and the shape is not limited to a flat shape but may be a concave-convex shape.
A laminated body (printed matter) can be obtained by providing a reversible thermochromic layer containing a reversible thermochromic composition on the support.
In the case where a non-thermochromic colored layer (including an image) is previously formed on the support, the colored layer can be concealed by a reversible thermochromic layer by a temperature change, and the change can be made. The aspect can be further diversified.
Further, the reversible thermochromic microcapsule pigment may be melt-blended into a thermoplastic resin, a thermocurable resin, waxes, etc. and used as a pellet, powder, or paste form as a resin composition for reversible thermochromic molding. Also, by means such as general-purpose injection molding, extrusion molding, blow molding, or casting molding, a molded product in the form of an arbitrary three-dimensional molded product, film, sheet, plate, filament, rod-shaped product, pipe, etc. can be obtained. Will be.
Further, it is also possible to obtain a crayon, a pencil lead, a mechanical pencil lead, a toner, and a powder paint by melt-blending with a thermoplastic resin or waxes.
A general dyeing pigment (non-thermally discoloring) may be blended in the liquid composition or the resin composition to exhibit a discoloration behavior from colored (1) to colored (2).
The light resistance is improved by laminating a layer containing a light stabilizer and / or a transparent metallic luster pigment on the laminated body or a molded body molded using the resin composition, or a top coat is applied. It is also possible to provide a layer to improve durability.
Examples of the light stabilizer include an ultraviolet absorber, an antioxidant, a singlet oxygen quenching agent, a superoxide anion quenching agent, and an ozone quenching agent.
Examples of the transparent metallic luster pigment include natural mica, synthetic mica, glass pieces, alumina, and a pigment in which the surface of a transparent film piece is coated with a metal oxide such as titanium oxide as a core material.

Specific examples of the product using the reversible thermochromic composition and the microcapsule pigment containing the composition include the following.
(1) Toys For dolls or animal elephant toys, hair for dolls or animal elephant toys, doll accessories such as doll houses and furniture, clothing, hats, bags, and shoes, accessory toys, stuffed animals, drawing toys, toys Picture books, puzzle toys such as jigsaw puzzles, stacking toys, block toys, clay toys, fluid toys, frames, kites, musical instrument toys, cooking toys, gun toys, capture toys, background toys and vehicles, animals, plants, buildings, and food. Toys that imitate, etc.
(2) Clothing T-shirts, sweatshirts, blouses, dresses, swimwear, raincoats, ski wear and other clothing, shoes and shoe strings and other footwear, handkerchiefs, towels, and cloth personal belongings such as bathrobes, gloves, ties and hats. etc,
(3) Interior decorations Carpets, curtains, curtain strings, table hangings, floor coverings, cushions, picture frames, artificial flowers, photo stands, etc.
(4) Furniture Duvets, pillows, bedding such as mattresses, lighting equipment, air conditioning equipment, etc.
(5) Ornaments Rings, bangles, tiaras, earrings, hair clips, artificial nails, ribbons, scarves, watches, eyeglasses, etc.
(6) Stationery Writing tools, stamping tools, erasers, underlays, rulers, adhesive tapes, etc.
(7) Daily necessities Lipsticks, eye shadows, nail polishes, hair dyes, artificial nails, cosmetics such as artificial nail paints, toothbrushes, etc.
(8) Kitchen utensils Cups, plates, chopsticks, spoons, forks, pots, frying pans, etc.
(9) Other calendars, labels, cards, recording materials, various printed materials to prevent counterfeiting, books such as picture books, bags, packaging containers, embroidery threads, exercise equipment, fishing gear, coasters, musical instruments, body warmers, cold storage agents, etc. Bags such as wallets, umbrellas, vehicles, buildings, temperature detection indicators, training tools, etc.

An example is shown below. In addition, the part in an Example shows a mass part.
Example 1
Preparation of reversible thermochromic composition (a) 1 part of pyridine derivative (compound 2 in the table) as a component, (b) 1,1-bis (4'-hydroxyphenyl) n-decane 5 parts, 2, as a component 2-Bis (4'-hydroxyphenyl) hexafluoropropane 4 parts, (c) 25 parts myristyl alcohol and 25 parts butyl stearate are mixed and dissolved by heating to change the color from fluorescent yellow to colorless. A reversible thermochromic composition was obtained.
The reversible thermochromic composition has a complete color development temperature (t ₁ ) of 7 ° C, a color development start temperature (t ₂ ) of 12 ° C, a decolorization start temperature (t ₃ ) of 10 ° C, and a complete decolorization temperature (t ₄ ). Was 15 ° C. and the hysteresis width (ΔH) was 3 ° C.

Examples 2 to 7
Preparation of Reversible Thermal Discoloration Microcapsule Pigment A reversible thermochromic composition was prepared by the same method as in Example 1 using the components (a), (b), and (c) shown in the table below, and the interface was prepared. A microcapsule pigment suspension encapsulated in microcapsules was obtained by a polymerization method.
The pigment was isolated from the microcapsule pigment suspension by centrifugation to obtain a reversible thermochromic microcapsule pigment having an average particle size of 2 μm.
In the table, the component (a) indicates the compound number as in Example 1, and the numbers in parentheses indicate the parts by mass.

Comparative Example 1
Preparation of reversible thermochromic composition (a) 1 part of 2,6-bis (4-dimethylaminophenyl) -4- (4-methoxyphenyl) pyridine as a component, and 1,1-bis (4) as a component (b) ′ -Hydroxyphenyl) n-decane 4 parts, 2,2-bis (4'-hydroxyphenyl) hexafluoropropane 4 parts, (c) 25 parts of myristyl alcohol and 25 parts of butyl stearate are mixed and heated. A reversible thermochromic composition was obtained, which was dissolved to change the color from fluorescent orange to colorless.
The reversible thermochromic composition has a complete color development temperature (t ₁ ) of 7 ° C, a color development start temperature (t ₂ ) of 11 ° C, a decolorization start temperature (t ₃ ) of 9 ° C, and a complete decolorization temperature (t ₄ ). Was 15 ° C. and the hysteresis width (ΔH) was 3 ° C.

Comparative Examples 2 and 3
Preparation of Reversible Thermal Discoloration Microcapsule Pigment A reversible thermochromic composition was prepared by the same method as in Comparative Example 1 using the components (a), (b), and (c) shown in the table below, and the interface was prepared. A microcapsule pigment suspension encapsulated in microcapsules was obtained by a polymerization method.
The pigment was isolated from the microcapsule pigment suspension by centrifugation to obtain a reversible thermochromic microcapsule pigment having an average particle size of 2 μm.
The numbers in parentheses in the table indicate the parts by mass.

Preparation of Measurement Samples The reversible thermochromic compositions of Example 1 and Comparative Example 1 were uniformly heated and melted, and then impregnated with filter paper (No. 2 filter paper manufactured by Toyo Filter Paper Co., Ltd.) to obtain measurement samples. ..
40 parts of the reversible thermochromic microcapsule pigments of Examples 2 to 7 and Comparative Examples 2 and 3 are 50 parts of an ethylene-vinyl acetate resin emulsion, 1 part of a leveling agent, 1 part of a defoaming agent, and 0.5 part of a viscosity adjusting agent. , A reversible thermochromic ink was prepared by uniformly dispersing in a water-based ink vehicle consisting of 7.5 parts of water.
A solid pattern was screen-printed on high-quality paper using the ink to obtain a measurement sample.

Measurement of hysteresis characteristics The measurement sample is set in the measurement part of a color difference meter (TC-3600 type color difference meter, manufactured by Tokyo Denshoku Co., Ltd.), and the sample part is heated and lowered at a rate of 2 ° C / min to each temperature. The lightness value was measured as the color density in, and a color density-temperature curve was created. From the color density-temperature curve, t ₁ , t ₂ , t ₃ , t ₄ , and ΔH (hysteresis width: temperature between t ₃ and t ₄ − temperature between t ₁ and t ₂ ) were determined.
The test results are shown in the table below.

Light resistance test After cooling each of the measured samples to a perfect color development temperature (t ₁ ) or lower to bring them into a colored state, a xenon light resistance tester (Suga tester (Suga tester)) is used in a temperature environment that does not exceed the decolorization start temperature (t ₃ ). The table sun XT75L) manufactured by Co., Ltd. was irradiated with light at 170 w / m ² irradiance every hour for up to 4 hours.
The Y color densities at the time of coloring and bleaching were measured with a reflection densitometer (manufactured by Konica Minolta, FD-7), and the density difference (density at the time of coloring-density at the time of bleaching) was determined.
The change in the concentration difference for each irradiation time was measured, assuming that the concentration difference at 0 hours of light irradiation was 100%.
The table below shows the results of the light resistance test.

Application example 1
Preparation of Reversible Thermal Discoloration Display As a support, an ink in which the reversible thermochromic microcapsule pigment prepared in Example 2 is dispersed in a vehicle containing a binder resin is used on the surface of a white polyester film (thickness 25 μm). A reversible discoloration layer was provided by printing, and the upper surface thereof was laminated with a transparent polyester film having a thickness of 16 μm to obtain a reversible thermochromic display.
The display body was once cooled to −18 ° C. or lower, the reversible discoloration layer was completely colored yellow, and then printed using a thermal transfer printer to form white blank characters.
The white characters are visible as long as the display is held in the temperature range of −18 ° C. to 64 ° C.
Further, when the display body is cooled to -18 ° C. or lower again and the reversible discoloration layer is completely colored yellow, the white characters are not visible, and the white characters are formed by using the thermal transfer printer. , Could be used over and over again.

Application example 2
Preparation of reversible thermochromic miniature car 15 parts of reversible thermochromic microcapsule pigment prepared in Example 4, 40 parts of 50% acrylic resin / xylene solution, 20 parts of xylene, 20 parts of methylisobutylketone, polyisocyanate-based curing agent 5 A reversible thermochromic spray paint was obtained by stirring and mixing in a vehicle consisting of parts.
The reversible thermochromic spray paint was spray-painted on the entire body of the white miniature car and dried to provide a reversible thermochromic layer to obtain a reversible thermochromic miniature car (toy).
In the miniature car, the reversible thermochromic layer developed red at room temperature (25 ° C.), but turned white when immersed in warm water at 39 ° C. When it was taken out of warm water and left at room temperature, it turned red again, and the above-mentioned aspect could be repeated.

Application example 3
Preparation of reversible heat-discoloring mug cup 30 parts of reversible heat-discoloring microcapsule pigment prepared in Example 5, 60 parts of hard liquid epoxy resin, 2 parts of ultraviolet absorber, 2 parts of shake-modifying agent, 0.5 part of defoaming agent Was mixed, and 40 parts of a room temperature curable aliphatic polyamine was further added to obtain a reversible thermochromic epoxy ink.
Using the reversible heat-discoloring epoxy ink, a heart pattern is printed on the side surface of a ceramic mug with a stainless steel screen plate using a curved printing machine, and heat-cured at 70 ° C. for 1 hour to provide a reversible heat-discoloring layer. , A reversible thermochromic mug was obtained.
In the mug, the reversible thermal discoloration layer turns red at room temperature (25 ° C) and the heart pattern is visible, but when hot water at 58 ° C is poured, the reversible thermal discoloration layer disappears and becomes colorless. .. When the hot water is removed from this state or the hot water temperature becomes 43 ° C. or lower, the reversible thermal discoloration layer develops color and the red heart pattern is visually recognized again.
It should be noted that this aspect change could be repeated by changing the temperature.

Application example 4
Preparation of ballpoint pen 20 parts of reversible thermochromic microcapsule pigment (preliminarily cooled to -18 ° C or lower to develop a yellow color) prepared in Example 7, 0.3 parts of xanthan gum, 10 parts of urea, 10 parts of glycerin, A reversible thermochromic ink composition consisting of 0.5 part of a nonionic penetrant-imparting agent, 0.1 part of a modified silicone-based defoaming agent, 0.2 part of an antiseptic, and 58.9 parts of water was prepared.
The reversible thermochromic ink composition was suction-filled in a polypropylene pipe, and a 0.5 mm stainless steel ball was connected to a ballpoint pen tip held at the tip via a resin holder.
Next, from the rear end of the polyprene pipe, an ink backflow preventive body (liquid plug) having viscoelasticity containing polybutene as a main component is filled, and further, the tail plug is fitted to the rear part of the pipe, and the toe shaft cylinder and the rear After assembling the shaft cylinder and fitting the cap, deaeration treatment was performed by centrifugation to obtain a ballpoint pen.
SEBS rubber is attached to the rear portion of the rear axle cylinder as a friction body.
Yellow characters (handwriting) were formed by writing on paper using the ballpoint pen.
The handwriting is yellow at room temperature (25 ° C), and when the characters are rubbed with a friction body, the characters are discolored and become colorless, and this state should be maintained unless cooled to -18 ° C or lower. Was done.
When the paper surface was placed in a freezer and cooled to -18 ° C. or lower, the characters turned yellow again, and the discoloration behavior could be reproduced repeatedly.

Application example 5
Preparation of marking pen 25.0 parts of reversible thermochromic microcapsule pigment (preliminarily cooled to -18 ° C or lower to develop a yellow color) prepared in Example 7, comb-type polymer dispersant [Nippon Lubrizol (Nippon Lubrizol ( Made by Co., Ltd., trade name: Solsparse 43000] 0.5 part, organic nitrogen sulfur compound [manufactured by Hokuko Chemical Industry Co., Ltd., trade name: Hokuside R-150, 2-methyl-4-isothiazolin-3-one and 5-on Mixture of chloro-2-methyl-4-isothiazolin-3-one] 1.0 part, polyvinyl alcohol 0.5 part, glycerin 35.0 part, defoaming agent 0.02 part, water 37.98 part are mixed. A reversible thermochromic ink composition was obtained.
The ink composition is impregnated in an ink occlusion body coated with a polyester sliver with a synthetic resin film, and the ink composition is housed in a barrel made of polypropylene resin. A polyester fiber resin-processed pen body (chisel type) is held at the tip of the barrel. I assembled it in a connected state, attached a cap, and obtained a marking pen.
SEBS resin is attached to the rear end of the barrel as a friction member.
Yellow characters (handwriting) were formed by writing on the paper surface using the marking pen.
The handwriting is yellow at room temperature (25 ° C), and when the characters are rubbed with a friction body, the characters are discolored and become colorless, and this state should be maintained unless cooled to -18 ° C or lower. Was done.
When the paper surface was placed in a freezer and cooled to -18 ° C. or lower, the characters turned yellow again, and the discoloration behavior could be reproduced repeatedly.

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

Claims (9)

(A) Electron transfer reaction between a pyridine derivative represented by the following general formula (1) as an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) the above-mentioned (a) and (b) components. A reversible thermochromic composition comprising a reaction medium that reversibly occurs in a specific temperature range.

(In the formula, R ₁ and R ₂ are independently hydrogen atoms, alkyl groups having 1 to 6 carbon atoms, acyl groups having 1 to 6 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 20 carbon atoms, respectively. , R ₃ to R ₇ are independent hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, alkoxy groups or halogen groups having 1 to 6 carbon atoms, and R ₈ to R ₁₂ are independent hydrogen atoms, respectively. It is an alkyl group having 1 to 8 carbon atoms, an alkoxy group or a halogen group having 1 to 6 carbon atoms, and Ar is a substituted or unsubstituted aromatic heterocyclic group.) The reversible thermochromic composition according to claim 1, wherein R ₁ and R ₂ of the pyridine derivative are independently an alkyl group having 1 to 6 carbon atoms and a substituted or unsubstituted aryl group having 6 to 20 carbon atoms. The reversible thermochromic composition according to claim 2, wherein R ₁ and R ₂ of the pyridine derivative are an ethyl group or a p-tolyl group. The reversible thermochromic composition according to any one of claims 1 to 3, wherein Ar of the pyridine derivative is any one of a thienyl group, a frill group, a thiazolyl group, and a pyridinyl group. A reversible thermochromic microcapsule pigment containing the reversible thermochromic composition according to any one of claims 1 to 4. A reversible thermochromic liquid composition comprising the reversible thermochromic microcapsule pigment according to claim 5 and a vehicle. The reversible thermochromic liquid composition according to claim 6, which is selected from printing inks, writing tool inks, coating tool inks, inkjet inks, paints, ultraviolet curable inks, paints, cosmetics, and coloring liquids for fibers. A resin composition for reversible thermochromic molding comprising the reversible thermochromic microcapsule pigment according to claim 5 and a molding resin. A reversible thermochromic laminate comprising a reversible thermochromic layer containing the reversible thermochromic microcapsule pigment according to claim 5 on a support.

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