JP2012046556A - Reversible-thermochromism composition and reversible-thermochromism microcapsule pigment containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reversible-thermochromism composition using a pyridine-based compound and a reversible-thermochromism microcapsule pigment.SOLUTION: The reversible-thermochromism composition comprises: (a) a pyridine derivative represented by a general formula (1); (b) an electron-accepting compound; and (c) a reaction medium. (In the formula, Rand Reach represent an alkyl group or the like, and n represents an integer of 1-3).

Description

  The present invention relates to a reversible thermochromic composition and a reversible thermochromic microcapsule pigment encapsulating the composition. More specifically, the present invention relates to a reversible thermochromic composition that exhibits an orange color when colored and colorless when decolored, and a reversible thermochromic microcapsule pigment encapsulating the composition.

  Conventionally, yellow or orange color is formed colorless from a compatible solution consisting essentially of a reaction medium that reversibly generates an electron-donating reaction between an electron-donating color-forming organic compound and an electron-accepting compound in a specific temperature range. Several proposals have been disclosed regarding reversible thermochromic compositions (see, for example, Patent Documents 1 and 2).

JP 7-186540 A JP-A-8-127768

The conventional reversible thermochromic composition described above uses a pyridine-based compound as an electron-donating color-forming organic compound capable of exhibiting an orange color, but has a slight reddish yellow color or a dark orange color. It was not a clear orange color.
The present invention solves the above-described conventional problems, that is, it exhibits a clear orange color in a colored state, and has high practicality that changes from orange to colorless in a decoloring process at the time of cooling. It is an object to provide a reversible thermochromic composition.

（式中、Ｒ_１は炭素数１〜４のアルキル基又はフェニル基を示し、Ｒ２は炭素数１〜６のアルキル基を示し、ｎは１〜３の整数を示す。）
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。 The present invention provides (a) a pyridine derivative represented by the following general formula (1) as an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) the components (a) and (b). A reversible thermochromic composition comprising a reaction medium that reversibly causes an electron transfer reaction in a specific temperature range is a requirement.

(Wherein R ₁ represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, R 2 represents an alkyl group having 1 to 6 carbon atoms, and n represents an integer of 1 to 3)
Furthermore, a reversible thermochromic microcapsule pigment encapsulating the reversible thermochromic composition is required.

  The present invention uses a specific pyridine-based compound as an electron-donating color-developing organic compound, so that a reversible color-changing composition that exhibits a clear orange color when developing and becomes colorless when decolored, and a reversible thermo-color change that includes the same Microcapsule pigments can be obtained.

It is a graph explaining the hysteresis characteristic in the color density-temperature curve of a heat decoloring type reversible thermochromic composition. It is a graph explaining the hysteresis characteristic in the color density-temperature curve of the heat decoloring type reversible thermochromic composition having color memory. It is a graph explaining the hysteresis characteristic in the color density-temperature curve of a heat coloring type reversible thermochromic composition.

The reversible thermochromic composition includes (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction of the two occurs. A heat decolorable reversible thermochromic composition containing at least a component can be mentioned.
The reversible thermochromic composition discolors before and after a predetermined temperature (discoloration point), decolored in a temperature range above the high temperature side discoloration point, and developed in a temperature range below the low temperature side discoloration point. Presenting, there is only one specific state in the normal temperature range of the two states, the other state is maintained while the heat or cold energy required to develop the state is applied, When the application of heat or cold is eliminated, the hysteresis width (ΔH) returns to a state exhibited in a normal temperature range and has a relatively small characteristic (see FIG. 1).
Also, it shows a large hysteresis characteristic, that is, the shape of the curve plotting the change in color density due to the temperature change decreases from the higher temperature side than the color change temperature range, contrary to the case where the temperature is raised from the lower temperature side than the color change temperature range. The color changes by following a path that differs greatly from the case where it is performed, and a color development state in a low temperature region below the complete color development temperature (t ₁ ) or a color erase state in a high temperature region above the complete color erase temperature (t ₄ ) In addition, a heat-erasable reversible thermochromic composition having color memory in a specific temperature range [temperature range between t _{2 and} t ₃ (substantially two-phase holding temperature range)] can also be applied (see FIG. 2). .

The components (A), (B), and (C) will be specifically described below.
The pyridine compound represented by the general formula (1) is
2,6-bis (2-methoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2-ethoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2-propoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2-butoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2-pentyloxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2-hexyloxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (3-methoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (4-methoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2,4-dimethoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2,4,6-trimethoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2,4-diethoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2,4,6-triethoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine,
2,6-bis (2-methoxyphenyl) -4- (4- (4'-diethylamino) biphenylyl) -pyridine,
2,6-bis (2-ethoxyphenyl) -4- (4- (4'-diethylamino) biphenylyl) -pyridine,
2,6-bis (2-butoxyphenyl) -4- (4- (4'-diethylamino) biphenylyl) -pyridine,
2,6-bis (3-methoxyphenyl) -4- (4- (4'-diethylamino) biphenylyl) -pyridine,
2,6-bis (2,4-dimethoxyphenyl) -4- (4- (4'-diethylamino) biphenylyl) -pyridine,
2,6-bis (2,4-diethoxyphenyl) -4- (4- (4'-diethylamino) biphenylyl) -pyridine,
2,6-bis (2-methoxyphenyl) -4- (4- (4'-dipropylamino) biphenylyl) -pyridine,
2,6-bis (2-ethoxyphenyl) -4- (4- (4'-dipropylamino) biphenylyl) -pyridine,
2,6-bis (3-methoxyphenyl) -4- (4- (4'-dipropylamino) biphenylyl) -pyridine,
2,6-bis (2-methoxyphenyl) -4- (4- (4'-dibutylamino) biphenylyl) -pyridine,
2,6-bis (2-propoxyphenyl) -4- (4- (4'-dibutylamino) biphenylyl) -pyridine,
2,6-bis (4-methoxyphenyl) -4- (4- (4'-dibutylamino) biphenylyl) -pyridine,
2,6-bis (2-methoxyphenyl) -4- (4- (4'-diphenylamino) biphenylyl) -pyridine,
2,6-bis (2,4-diethoxyphenyl) -4- (4- (4'-diphenylamino) biphenylyl) -pyridine,
2,6-bis (2,4,6-trihexyloxyphenyl) -4- (4- (4'-diphenylamino) biphenylyl) -pyridine and the like can be mentioned.
Of the pyridine-based compounds, R ₁ represents an alkyl group or phenyl group having 1 to 3 carbon atoms in order to exhibit a good reversible thermochromic property that exhibits a clear orange color when developing and becomes colorless when decolored. R2 represents an alkyl group having 1 to 4 carbon atoms, n is preferably a compound having an integer of 1 to 3, R ₁ represents an alkyl group having 1 or 2 carbon atoms or a phenyl group, and R2 represents a carbon number. The compound which shows the alkyl group of 1 or 2 and n shows the integer of 1 or 2 is more suitable.

As the electron-accepting compound of the component (b), a group of compounds having active protons, a pseudo-acidic compound group [a group of compounds that are not acids but act as acids in the composition to cause the component (i) to develop color], There is a group of compounds having electron vacancies.
Examples of compounds having active protons include monophenols to polyphenols as compounds having phenolic hydroxyl groups, and alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, carboxy groups and esters thereof as substituents. Or what has an amide group, a halogen group, etc., a bis type | mold, a tris type | mold phenol, phenol-aldehyde condensation resin, etc. are mentioned. Moreover, the metal salt of the compound which has the said phenolic hydroxyl group may be sufficient.
Specific examples are given below.
Phenol, o-cresol, tertiary butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, n-butyl p-hydroxybenzoate N-octyl p-hydroxybenzoate, resorcin, dodecyl gallate, 2,2-bis (4-hydroxyphenyl) propane, 4,4-dihydroxydiphenylsulfone, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, 1-phenyl-1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4 -Hydroxyphenyl) -3-methylbu 1,1-bis (4-hydroxyphenyl) -2-methylpropane, 1,1-bis (4-hydroxyphenyl) n-hexane, 1,1-bis (4-hydroxyphenyl) n-heptane, , 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-ethylhexane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) ethyl Propionate, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 2,2 Bis (4-hydroxyphenyl) n- heptane, there is 2,2-bis (4-hydroxyphenyl) n- nonane.
The compound having a phenolic hydroxyl group can develop the most effective thermochromic property, but aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphate esters and their It may be a compound selected from metal salts, 1,2,3-triazole and derivatives thereof.

The component (c) of the reaction medium that causes the electron transfer reaction by the components (a) and (b) to occur reversibly in a specific temperature range will be described. Examples of the component (c) include alcohols, esters, ketones, ethers, and acid amides.
When the above compounds are used for microencapsulation and secondary processing, those having a low molecular weight evaporate out of the capsule when subjected to high heat treatment. These compounds are preferably used.
As the alcohols, aliphatic monovalent saturated alcohols having 10 or more carbon atoms are effective. Specifically, decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl Alcohol, heptadecyl alcohol, octadecyl alcohol, eicosyl alcohol, docosyl alcohol, etc. are mentioned.

  As the esters, esters having 10 or more carbon atoms are effective, and any combination of a monovalent carboxylic acid having an aliphatic and alicyclic or aromatic ring and a monohydric alcohol having an aliphatic and alicyclic or aromatic ring. Esters, aliphatic and alicyclic rings obtained from any combination of esters, aliphatic and alicyclic or aromatic polyvalent carboxylic acids obtained from the above and monohydric alcohols having aliphatic and alicyclic or aromatic rings Or esters obtained from any combination of monovalent carboxylic acid having an aromatic ring and aliphatic and alicyclic or polyhydric alcohol having an aromatic ring, specifically, ethyl caprylate, octyl caprylate, capryl Stearyl acid, myristyl caprate, docosyl caprate, 2-ethylhexyl laurate, n-decyl laurate, myris 3-methylbutyl acid, cetyl myristate, isopropyl palmitate, neopentyl palmitate, nonyl palmitate, cyclohexyl palmitate, n-butyl stearate, 2-methylbutyl stearate, 3,5,5-trimethylhexyl stearate, stearin N-undecyl acid, pentadecyl stearate, stearyl stearate, cyclohexylmethyl stearate, isopropyl behenate, hexyl behenate, lauryl behenate, behenyl behenate, cetyl benzoate, stearyl p-tert-butylbenzoate, dimyristyl phthalate , Distearyl phthalate, dimyristyl oxalate, dicetyl oxalate, dicetyl malonate, dilauryl succinate, dilauryl glutarate, diundecyl adipate, azelaic acid Lauryl, di- (n-nonyl) sebacate, dineopentyl 1,18-octadecylmethylenedicarboxylate, ethylene glycol dimyristate, propylene glycol dilaurate, propylene glycol distearate, hexylene glycol dipalmitate, 1,5-pentane Diol distearate, 1,2,6-hexanetriol trimyristate, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanedimethanol dimyristate, xylene glycol dicaprate, xylene glycol distearate, etc. Can be mentioned.

In addition, esters of saturated fatty acids and branched fatty alcohols, unsaturated fatty acids or branched or substituted saturated fatty acids and esters of fatty alcohols 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 caprate, 3,5,5-trimethylhexyl laurate, 3,5,5-trimethylhexyl palmitate, 3,5,5-trimethylhexyl stearate, 2-methylbutyl caproate, 2-methylbutyl caprylate, 2-methylbutyl caprate, 1-ethylpropyl palmitate, 1-ethylpropyl stearate, 1-ethylpropyl behenate, 1-ethylhexyl laurate, 1-ethylhexyl myristate, 1-ethylhexyl palmitate, 2-methylpentyl caproate, 2-methylpentyl caprylate, 2-methylpentyl caprate, 2-methylpentyl laurate, 2-stearate Mechi Butyl, 2-methylbutyl stearate, 3-methylbutyl stearate, 1-methylheptyl stearate, 2-methylbutyl behenate, 3-methylbutyl behenate, 1-methylheptyl stearate, 1-methylheptyl behenate, caproic acid 1 -Ethylpentyl, 1-ethylpentyl palmitate, 1-methylpropyl stearate, 1-methyloctyl stearate, 1-methylhexyl stearate, 1,1-dimethylpropyl laurate, 1-methylpentyl caprate, 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-Jime Luoctyl, 3,7-dimethyloctyl behenate, stearyl oleate, behenyl oleate, stearyl linoleate, behenyl linoleate, 3,7-dimethyloctyl erucate, stearyl erucate, isostearyl erucate, cetyl isostearate, isostearic acid Examples include stearyl acid, 2-methylpentyl 12-hydroxystearate, 2-ethylhexyl 18-bromostearate, isostearyl 2-ketomyristate, 2-ethylhexyl 2-fluoromyristate, cetyl butyrate, stearyl butyrate, and behenyl butyrate. It is done.

  Furthermore, with regard to the color density-temperature curve, there is a large hysteresis characteristic (the shape of the curve plotting the change in color density due to temperature change differs from the case where the temperature is changed from the low temperature side to the high temperature side from the discoloration temperature range. In order to give a color memory and thermal discoloration depending on the temperature change, it is disclosed in Japanese Patent Publication No. 4-17154 previously proposed by the present applicant. Carboxylic acid ester compounds exhibiting a ΔT value (melting point-cloud point) of 5 ° C. or higher and lower than 50 ° C., for example, carboxylic acid ester containing a substituted aromatic ring in the molecule, carboxylic acid and carbon containing an unsubstituted aromatic ring Esters of aliphatic alcohols of several tens or more, carboxylic acid esters having a cyclohexyl group in the molecule, esters of fatty acids having 6 or more carbon atoms and unsubstituted aromatic alcohols or phenols, Fatty acids of 8 or more and branched fatty alcohols or esters, dicarboxylic acids and esters of aromatic alcohols or branched aliphatic alcohols, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, adipic acid Examples include dicetyl, distearyl adipate, trilaurin, trimyristin, tristearin, dimyristin, and distearin.

Fatty acid ester compound obtained from an odd aliphatic monohydric alcohol having 9 or more carbon atoms and an aliphatic carboxylic acid having an even carbon number, n-pentyl alcohol or n-heptyl alcohol and an even aliphatic carboxylic acid having 10 to 16 carbon atoms A fatty acid ester compound having a total carbon number of 17 to 23 obtained from an acid is also effective.
Specifically, n-pentadecyl acetate, n-tridecyl butyrate, n-pentadecyl butyrate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caprylate, n-undecyl caprylate, N-tridecyl caprylate, n-pentadecyl caprylate, n-heptyl caprate, n-nonyl caprate, n-undecyl caprate, n-tridecyl caprate, n-pentadecyl caprate, n-pentyl laurate, lauric acid n-heptyl, n-nonyl laurate, n-undecyl laurate, n-tridecyl laurate, n-pentadecyl laurate, n-pentyl myristate, n-heptyl myristate, n-nonyl myristate, n-myristate Undecyl, n-tridecyl myristate, N-pentadecyl ristinate, n-pentyl palmitate, n-heptyl palmitate, n-nonyl palmitate, n-undecyl palmitate, n-tridecyl palmitate, n-pentadecyl palmitate, n-nonyl stearate, stearic acid n-undecyl, n-tridecyl stearate, n-pentadecyl stearate, n-nonyl eicosanoate, n-undersi eicosanoate, n-tridecyl eicosanoate, n-pentadecyl eicosanoate, n-nonyl behenate, n-behenate Examples include undecyl, n-tridecyl behenate, and n-pentadecyl behenate.

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-nonadacanone, 2-eicosanone, 11-eicosanone, 2-heneicosanone, 2-docosanone, laurone, stearone and the like.
Further, arylalkyl ketones having a total carbon number of 12 to 24, such as n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradecane. Nophenone, 4-n-dodecanacetophenone, n-tridecanophenone, 4-n-undecanoacetophenone, n-laurophenone, 4-n-decanoacetophenone, n-undecanophenone, 4-n-nonylacetophenone, n-decanophenone, 4-n-octylacetophenone, n-nonanophenone, 4-n-heptylacetophenone, n-octanophenone, 4-n-hexylacetophenone, 4-n-cyclohexylacetophenone, 4-tert-butylpropiophenone , N-heptaphenone, 4-n-pentylacetofu Non, cyclohexyl phenyl ketone, benzyl -n- butyl ketone, 4-n-butyl acetophenone, n- hexanophenone, 4-isobutyl acetophenone, 1-acetonaphthone, 2-acetonaphthone, cyclopentyl phenyl ketone.

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

  Acid amides include acetamide, propionic acid amide, butyric acid amide, caproic acid amide, caprylic acid amide, capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide , Erucic acid amide, benzamide, caproic acid anilide, caprylic acid anilide, capric acid anilide, lauric acid anilide, myristic acid anilide, palmitic acid anilide, stearic acid anilide, behenic acid anilide, oleic acid anilide, erucic acid anilide, caproic acid N -Methylamide, caprylic acid N-methylamide, capric acid N-methylamide, lauric acid N-methylamide, myristic acid N-methylamide, palmitic acid N-methylamide, stearic acid N-methylamido , Behenic acid N-methylamide, oleic acid N-methylamide, erucic acid N-methylamide, lauric acid N-ethylamide, myristic acid N-ethylamide, palmitic acid N-ethylamide, stearic acid N-ethylamide, oleic acid N-ethylamide, laurin Acid N-butyramide, myristic acid N-butyramide, palmitic acid N-butyramide, stearic acid N-butyramide, oleic acid N-butyramide, lauric acid N-octylamide, myristic acid N-octylamide, palmitic acid N-octylamide, Stearic acid N-octylamide, oleic acid N-octylamide, lauric acid N-dodecylamide, myristic acid N-dodecylamide, palmitic acid N-dodecylamide, stearic acid N-dodecylamide, olei 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, tristearic acid amide, trioleic acid Amide, succinic acid amide, adipic acid amide, glutaric acid amide, malonic acid amide, azelaic acid amide, maleic acid amide, succinic acid N-methylamide, adipic acid N-methylamide, glutaric acid N-methylamide, malonic acid N-methylamide, Azelaic acid N-methylamide, succinic acid N-ethylamide, adipic acid N-ethylamide, glutaric acid N-ethylamide, malonic acid N-ethylamide, azelaic acid N-ethylamide, succinic acid N-butylamide, adipic acid N- Examples include butyramide, glutaric acid N-butyramide, malonic acid N-butyramide, adipic acid N-octylamide, adipic acid N-dodecylamide, and the like.

〔式中、Ｒ_１は水素原子又はメチル基を示し、ｍは０〜２の整数を示し、Ｘ_１、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（２）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（２）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。 Moreover, the compound shown by following General formula (2) can also be used as said (c) component.

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

R in the formula represents an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, more preferably an alkyl group having 12 to 22 carbon atoms.
Specific examples of the compound include octanoic acid-4-benzyloxyphenylethyl, nonanoic acid-4-benzyloxyphenylethyl, decanoic acid-4-benzyloxyphenylethyl, undecanoic acid-4-benzyloxyphenylethyl, and dodecanoic acid. -4-benzyloxyphenylethyl, tridecanoic acid-4-benzyloxyphenylethyl, tetradecanoic acid-4-benzyloxyphenylethyl, pentadecanoic acid-4-benzyloxyphenylethyl, hexadecanoic acid-4-benzyloxyphenylethyl, heptadecanoic acid Examples thereof include -4-benzyloxyphenylethyl and octadecanoic acid-4-benzyloxyphenylethyl.

（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。 Furthermore, a compound represented by the following general formula (4) can also be used as the component (c).

(In the formula, R represents an alkyl group or alkenyl group having 8 or more carbon atoms, m and n each represents an integer of 1 to 3, X and Y represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, carbon, respectively. (The alkoxy group of Formula 1-4 is shown, and a halogen.)
Specific examples of the compound include 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, 1,1-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 An example is 1,1-diphenylmethyl.

（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。 Furthermore, a compound represented by the following general formula (5) can also be used as the component (c).

(Wherein, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom, m represents an integer of 1 to 3, and n represents an integer of 1 to 20)
Examples of the compound include a diester of malonic acid and 2- [4- (4-chlorobenzyloxy) phenyl)] ethanol, a diester of succinic acid and 2- (4-benzyloxyphenyl) ethanol, succinic acid and 2- Diester with [4- (3-methylbenzyloxy) phenyl)] ethanol, diester with glutaric acid and 2- (4-benzyloxyphenyl) ethanol, glutaric acid and 2- [4- (4-chlorobenzyloxy) Phenyl)] ethanol diester, adipic acid and 2- (4-benzyloxyphenyl) ethanol diester, pimelic acid and 2- (4-benzyloxyphenyl) ethanol diester, suberic acid and 2- (4- Diester with benzyloxyphenyl) ethanol, suberic acid and 2- [4- (3-methyl Benzyloxy) phenyl)] ethanol diester, suberic acid and 2- [4- (4-chlorobenzyloxy) phenyl)] ethanol diester, suberic acid and 2- [4- (2,4-dichlorobenzyloxy) ) Phenyl)] ethanol diester, azelaic acid and 2- (4-benzyloxyphenyl) ethanol diester, sebacic acid and 2- (4-benzyloxyphenyl) ethanol diester, 1,10-decanedicarboxylic acid And 2- (4-benzyloxyphenyl) ethanol diester, 1,18-octadecanedicarboxylic acid and 2- (4-benzyloxyphenyl) ethanol diester, 1,18-octadecanedicarboxylic acid and 2- [4- (2-Methylbenzyloxy) phenyl)] di with ethanol It can be exemplified ester.

（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。 Furthermore, a compound represented by the following general formula (6) can also be used as the component (c).

(In the formula, R represents an alkyl group or alkenyl group having 1 to 21 carbon atoms, and n represents an integer of 1 to 3).
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 -Hydroxyethoxy) benzene and lauric acid diester, 1,3-bis (2-hydroxyethoxy) benzene and myristic acid diester, 1,4-bis (hydroxymethoxy) benzene and butyric acid diester, 1,4 Diesters of bis (hydroxymethoxy) benzene and isovaleric acid, diesters of 1,4-bis (2-hydroxyethoxy) benzene and acetic acid, and 1,4-bis (2-hydroxyethoxy) benzene and propionic acid Diester, diester of 1,4-bis (2-hydroxyethoxy) benzene and valeric acid Diester of 1,4-bis (2-hydroxyethoxy) benzene and caproic acid, diester of 1,4-bis (2-hydroxyethoxy) benzene and caprylic acid, 1,4-bis (2-hydroxyethoxy) benzene And diester of capric acid, 1,4-bis (2-hydroxyethoxy) benzene and lauric acid, and 1,4-bis (2-hydroxyethoxy) benzene and myristic acid.

  The reversible thermochromic composition of the present invention is a compatible solution containing the components (a), (b) and (c) as essential components, and the ratio of each component is the concentration, color change temperature, color change form and each component. In general, the component ratio for obtaining desired characteristics is (b) component 1 to (b) component 0.1 to 100, preferably 0.1 to 50, (c) ) In the range of components 5 to 100 (all the proportions are parts by mass).

  Further, as an electron-accepting compound, a specific alkoxyphenol compound having a linear or side chain alkyl group having 3 to 18 carbon atoms (Japanese Patent Laid-Open No. 11-129623), a specific hydroxybenzoic acid ester (Japanese Patent Laid-Open No. 2001-105732). Gazette), gallic acid esters (Japanese Patent Laid-Open No. 2003-253149), and the like, and can also be used as a heat-developing reversible thermochromic composition (see FIG. 3).

Furthermore, various light stabilizers can be added as necessary.
The light stabilizer is contained to prevent photodegradation of the reversible thermochromic composition comprising the components (A), (B), and (C), and is 0.3% relative to 1% by mass of the component (A). It is contained in a proportion of ˜24 mass%, preferably 0.3 to 16 mass%. Of the light stabilizers, the ultraviolet absorber effectively cuts ultraviolet rays contained in sunlight and the like, and prevents light degradation caused by the excited state due to the photoreaction of component (a). Antioxidants, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers and the like suppress the oxidation reaction caused by light.
The said light stabilizer may be used independently and may be used in combination of 2 or more type.

The reversible thermochromic composition is effective when applied as it is, but is preferably used as a microcapsule pigment encapsulated in microcapsules. This is because the reversible thermochromic composition can be kept in the same composition under the various use conditions and can exhibit the same effects.
Microencapsulation includes conventionally known interfacial polymerization methods, in situ polymerization methods, in-liquid curing coating methods, phase separation methods from aqueous solutions, phase separation methods from organic solvents, melt dispersion cooling methods, air suspensions. There are a coating method, a spray drying method, and the like, which are appropriately selected according to the application. Further, a secondary resin film may be provided on the surface of the microcapsule according to the purpose to impart durability, or the surface characteristics may be modified for practical use.
By encapsulating in the microcapsule, a chemically and physically stable pigment can be constituted, and a particle diameter of 0.01 to 50 μm, preferably 0.1 to 30 μm, more preferably 0.5 to 20 μm is practical. Satisfy sex.
The particle diameter is measured using a laser diffraction / scattering particle size distribution measuring apparatus (manufactured by Horiba, Ltd .; LA-300), and the average particle diameter (median diameter) is calculated based on the numerical value. .

The reversible thermochromic composition and the reversible thermochromic microcapsule pigment encapsulating the same are dispersed in a vehicle containing water and / or an organic solvent and optionally various additives, and screen printing, offset printing, process printing, Printing ink used for gravure printing, coater, tampo printing, brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, dip coating, etc., ink for inkjet, UV curable ink It can be used as a reversible thermochromic liquid composition such as ink for writing tools or applicators for marking pens, ballpoint pens, fountain pens, and pens, paints, cosmetics, and coloring liquids for fibers.
Various additives can be added to the liquid composition, such as resin, crosslinking agent, curing agent, drying agent, plasticizer, viscosity modifier, dispersant, ultraviolet absorber, antioxidant, light stabilizer, sedimentation. Examples thereof include an inhibitor, a smoothing agent, a gelling agent, an antifoaming agent, a matting agent, a penetrating agent, a pH adjusting agent, a foaming agent, a coupling agent, a moisturizing agent, an antifungal agent, an antiseptic and an antirust agent.
A reversible thermochromic laminate is formed by providing a reversible thermochromic layer on a support of various materials and shapes using the liquid composition described above.
The reversible thermochromic layer is a layer formed by volatilization of the solvent in the liquid composition and other components (additives), and the microcapsule pigment is fixed to the resin in a dispersed state.
The material of the support on which the liquid composition is applied is not specified and is all effective; paper, synthetic paper, thread, fiber, fabric, nonwoven fabric, synthetic leather, leather, plastic, glass, ceramics, metal, wood, A stone material etc. can be illustrated and not only a planar shape but uneven | corrugated shape may be sufficient.
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 temperature change, and the aspect of the change is further diversified. be able to.
Furthermore, in addition to providing a reversible thermochromic layer on the support using the liquid composition, a reversible thermochromic layer can be formed on the support using a transfer sheet provided with a reversible thermochromic layer in advance.
The reversible thermochromic microcapsule pigment can be used as a reversible thermochromic molding resin composition in the form of a pellet, powder, or paste by melt blending with a thermoplastic resin, thermosetting resin, wax, or the like.
Using the molding resin, by means of general-purpose injection molding, extrusion molding, blow molding, cast molding, etc., any form of three-dimensional modeled object, film, sheet, plate, filament, rod-shaped object, pipe, etc. A molded body is obtained.
In addition, general dye and pigment (non-thermochromic property) can be mix | blended in the said liquid composition and the resin composition for shaping | molding, and the discoloration behavior from colored (1) to colored (2) can also be exhibited.
Light resistance is improved by laminating a layer containing a light stabilizer and / or a transparent metallic luster pigment on the laminate or a molded article molded using the resin composition, or a top coat. A layer can also be provided to improve durability.
Examples of the light stabilizer include ultraviolet absorbers, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, and ozone quenchers.
Examples of the transparent metallic luster pigment include natural mica, synthetic mica, glass pieces, alumina, and a pigment obtained by coating the surface of a transparent film piece with a metal oxide such as titanium oxide.

  Specifically, as the product using the reversible thermochromic composition and the reversible thermochromic microcapsule pigment encapsulating the same, doll or animal figure toy, doll or animal figure toy hair, doll house or furniture, clothing Doll accessories such as hats, bags, shoes, accessory toys, plush toys, drawing toys, toy picture books, puzzle toys such as jigsaw puzzles, building toys, block toys, clay toys, fluid toys, tops, bags, musical instrument toys, Cooking toys, gun toys, capture toys, background toys, vehicles, animals, plants, buildings, toys that imitate food, T-shirts, trainers, blouses, dresses, swimsuits, raincoats, ski wears, shoes, Footwear such as shoelaces, handicrafts such as handkerchiefs, towels and furoshiki, indoor ornaments such as carpets, curtains, curtain straps, table racks, rugs, cushions, picture frames, artificial flowers, etc. Bedclothes such as futons, pillows, mattresses, rings, bangles, tiaras, earrings, hair stoppers, false nails, ribbons, scarves, etc. Cosmetics such as eye shadow, nail polish, hair dye, artificial nail, artificial nail paint, cups, dishes, chopsticks, spoons, forks, pans, frying pans, and other kitchenware, calendars, labels, cards, recording materials, forgery prevention Various printed materials, books such as picture books, gloves, ties, hats, bags, packaging containers, embroidery thread, exercise equipment, fishing gear, toothbrushes, coasters, watches, glasses, lighting equipment, air conditioning equipment, musical instruments, warmers, cool storage agents Examples include photo stands, bags such as wallets, umbrellas, furniture, vehicles, buildings, temperature detection indicators, and teaching tools.

Examples are shown below. In addition, the part in an Example shows a mass part.
Example 1
Preparation of reversible thermochromic composition (i) 0.3 part of 2,6-bis (2-ethoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine as component (b) 1,1-bis (4′-hydroxyphenyl) n-decane 0.5 part as component, 0.3 part 2,2-bis (4′-hydroxyphenyl) hexafluoropropane, (c) neopentyl stearate as component 50.0 parts was mixed, and the mixture was heated and dissolved uniformly to obtain a reversible thermochromic composition that changes from orange to colorless.
The reversible thermochromic composition has a complete color development temperature (t ₁ ) of 13 ° C., a color development start temperature (t ₂ ) of 15 ° C., a color erase start temperature (t ₃ ) of 28 ° C., and a complete color erase temperature (t ₄ ). Was 32 ° C.

Example 2
Preparation of reversible thermochromic microcapsule pigment (a) 1.0 part of 2,6-bis (2-ethoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine as component (B) A reversible thermochromic composition consisting of 8.0 parts of 1,1-bis (4′-hydroxyphenyl) n-decane as a component and 50.0 parts of stearyl stearate as a component (c) is uniformly heated and dissolved. Then, a microcapsule pigment suspension encapsulated in microcapsules was obtained by an interfacial polymerization method.
The pigment was isolated from the microcapsule pigment suspension by centrifugation to obtain a reversibly thermochromic microcapsule pigment having an average particle size of 2 μm and changing from orange to colorless.
The reversible thermochromic composition has a complete color development temperature (t ₁ ) of 43 ° C., a color development start temperature (t ₂ ) of 51 ° C., a color erase start temperature (t ₃ ) of 45 ° C., and a complete color erase temperature (t ₄ ). Was 58 ° C.

Example 3
Preparation of reversible thermochromic microcapsule pigment (a) 1.0 part of 2,6-bis (2,4-diethoxyphenyl) -4- (4- (4'-dimethylamino) biphenylyl) -pyridine as component A reversible thermochromic composition consisting of 8.0 parts of 1,1-bis (4′-hydroxyphenyl) n-decane as the component (b) and 50.0 parts of octadecyl decanoate as the component (c) was uniformly added. A microcapsule pigment suspension encapsulated in microcapsules by an interfacial polymerization method was obtained by dissolution at a temperature.
The pigment was isolated from the microcapsule pigment suspension by centrifugation to obtain a reversibly thermochromic microcapsule pigment having an average particle size of 2 μm and changing from orange to colorless.
The reversible thermochromic composition has a complete color development temperature (t ₁ ) of 26 ° C., a color development start temperature (t ₂ ) of 31 ° C., a color erase start temperature (t ₃ ) of 30 ° C., and a complete color erase temperature (t ₄ ). Was 39 ° C.

Example 4
Preparation of reversible thermochromic microcapsule pigment (i) 1.0 part of 2,6-bis (2,4-diethoxyphenyl) -4- (4- (4′-diethylamino) biphenylyl) -pyridine as component (B) Component 1,5-bis (4'-hydroxyphenyl) n-decane 5.0 parts, 2,2-bis (4'-hydroxyphenyl) hexafluoropropane 3.0 parts, (C) As component A reversible thermochromic composition composed of 50.0 parts of 4-benzyloxyphenylethyl caprate was uniformly heated and dissolved to obtain a microcapsule pigment suspension encapsulated in microcapsules by an interfacial polymerization method.
The pigment was isolated from the microcapsule pigment suspension by centrifugation to obtain a reversibly thermochromic microcapsule pigment having an average particle size of 2 μm and changing from orange to colorless.
The reversible thermochromic composition has a complete color development temperature (t ₁ ) of −15 ° C., a color development start temperature (t ₂ ) of −5 ° C., a color erase start temperature (t ₃ ) of 47 ° C., and a complete color erase temperature (t ₄ ) was 62 ° C.

Example 5
Preparation of reversible thermochromic microcapsule pigment (i) 1.0 part of 2,6-bis (2,4-diethoxyphenyl) -4- (4- (4'-diphenylamino) biphenylyl) -pyridine as component (B) Component 1,5-bis (4'-hydroxyphenyl) n-decane 5.0 parts, 2,2-bis (4'-hydroxyphenyl) hexafluoropropane 3.0 parts, Component (c) A reversible thermochromic composition consisting of 50.0 parts of 4-benzyloxyphenyl ethyl caprate was uniformly heated and dissolved to obtain a microcapsule pigment suspension encapsulated in microcapsules by an interfacial polymerization method.
The pigment was isolated from the microcapsule pigment suspension by centrifugation to obtain a reversibly thermochromic microcapsule pigment having an average particle size of 2 μm and changing from orange to colorless.
The reversible thermochromic composition has a complete color development temperature (t ₁ ) of −15 ° C., a color development start temperature (t ₂ ) of −5 ° C., a color erase start temperature (t ₃ ) of 47 ° C., and a complete color erase temperature (t ₄ ) was 62 ° C.

Comparative Example 1
Preparation of reversible thermochromic composition (i) 0.3 part of 4- (4-methoxyphenyl) -2,6-bis (4-dimethylaminophenyl) -pyridine as component (1,) 1,1- Mix 0.5 parts of bis (4'-hydroxyphenyl) n-decane, 0.3 parts of 2,2-bis (4'-hydroxyphenyl) hexafluoropropane, and 50.0 parts of neopentyl stearate as component (c). Then, a reversible thermochromic composition that was uniformly heated and dissolved to change the color from orange to colorless was obtained.
The reversible thermochromic composition has a complete color development temperature (t ₁ ) of 13 ° C., a color development start temperature (t ₂ ) of 15 ° C., a color erase start temperature (t ₃ ) of 28 ° C., and a complete color erase temperature (t ₄ ). Was 32 ° C.

Comparative Example 2
Preparation of reversible thermochromic microcapsule pigment (a) 1.0 part of 4-phenyl-2,6-bis (4-dimethylaminophenyl) -pyridine as component, 1,1-bis (4'-hydroxy) as component (b) Phenyl) reversible consisting of 5.0 parts of n-decane, 3.0 parts of 2,2-bis (4'-hydroxyphenyl) hexafluoropropane, and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c). The thermochromic composition was uniformly heated and dissolved, and a microcapsule pigment suspension encapsulated in microcapsules was obtained by an interfacial polymerization method.
The pigment was isolated from the microcapsule pigment suspension by centrifugation to obtain a reversibly thermochromic microcapsule pigment having an average particle size of 2 μm and changing from orange to colorless.
The reversible thermochromic composition has a complete color development temperature (t ₁ ) of −18 ° C., a color development start temperature (t ₂ ) of −7 ° C., a color erase start temperature (t ₃ ) of 48 ° C., and a complete color erase temperature (t ₄ ) was 64 ° C.

Preparation of measurement sample 30.0 parts of the reversible thermochromic composition of Example 1 and Comparative Example 1 were dissolved in methyl ethyl ketone, and then impregnated into filter paper (No. 2 filter paper manufactured by Toyo Filter Paper Co., Ltd.). Obtained.
Reversible heat in which 40.0 parts of the microcapsule pigments of Examples 2 to 5 and Comparative Example 2 were mixed with 52.0 parts of an ethylene-vinyl acetate copolymer resin emulsion, 5.0 parts of a thickener, and 3.0 parts of a leveling agent. A test sample was obtained by printing a circle (reversible thermochromic layer) of a predetermined size on fine paper by screen printing using a color-changing ink.

Color development test Each of the test samples was cooled below the complete color development temperature, and the state in which the test sample was colored was visually observed.
The test results are shown in the following table.

The explanation of the test result symbols in the table is as follows.
○: A clear orange color is exhibited.
X: Although the color density of the thing which shows orange is low, a color is dark.

  From the test results, both the reversible thermochromic composition of the present invention and the sample using the microcapsule pigment encapsulating the composition exhibit a clear orange color when colored. On the other hand, neither the composition prepared in the comparative example nor the sample using the microcapsule pigment encapsulating the composition exhibited a clear orange color.

Application example 1
Preparation of reversible thermochromic mug 30 parts of reversible thermochromic microcapsule pigment prepared in Example 2, 60 parts of hard liquid epoxy resin, 2 parts of UV absorber, 2 parts of thixotropic agent, 0.5 part of antifoaming agent And 40 parts of room temperature curable aliphatic polyamine was added to obtain a reversible thermochromic epoxy ink.
Using the reversible thermochromic epoxy ink, a star pattern is printed on the side of a ceramic mug using a curved surface printing machine with a stainless steel screen plate, and heat cured at 70 ° C. for 1 hour to provide a reversible thermochromic layer. A reversible thermochromic mug was obtained.
In the mug, the reversible thermochromic layer is colored orange at room temperature (25 ° C.). However, when 90 ° C. hot water is poured, the reversible thermochromic layer is decolored and becomes colorless. When hot water is removed from this state, or when the hot water temperature is 43 ° C. or lower, the reversible thermochromic layer is colored and an orange mug is visible again.
It should be noted that this mode change could be repeatedly performed by a temperature change.

Application example 2
Stir and mix in a vehicle comprising 15 parts of reversible thermochromic microcapsule pigment prepared in Example 3, 40 parts of a 50% acrylic resin / xylene solution, 20 parts of xylene, 20 parts of methyl isobutyl ketone, and 5 parts of a polyisocyanate curing agent. As a result, a reversible thermochromic spray paint was obtained.
The reversible thermochromic spray paint was spray-coated on the entire body of a white miniature car and dried to provide a reversible thermochromic layer to obtain a reversible thermochromic miniature car.
In the miniature car, the reversible thermochromic layer colored orange at room temperature (25 ° C.), but turned white when immersed in warm water of 39 ° C. When it was taken out from warm water and allowed to stand at room temperature, it turned orange again, and the above aspect could be repeated.

Application example 3
Preparation of reversible thermochromic display body As a support, an ink in which the reversible thermochromic microcapsule pigment prepared in Example 4 was dispersed in a vehicle containing a binder resin on the surface of a white polyester film (thickness 25 μm) was used. Printing was provided with a reversible color-changing layer, 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 was once cooled to −15 ° C. or lower, and the reversible color-changing layer was completely colored orange, and then printed using a thermal transfer printer to form white blank characters.
As long as the said display body is hold | maintained in the temperature range of -15 degreeC-62 degreeC, the said white extraction letter is visually recognized.
In addition, when the display body is cooled again to −15 ° C. or less and the reversible color changing layer is completely colored in orange, the white letters are not visible, and the white letters are formed using the thermal transfer printer. Could be used over and over again.

Application example 4
Preparation of Ballpoint Pen 20 parts of the reversible thermochromic microcapsule pigment prepared in Example 5 (previously cooled to −15 ° C. or less and colored orange), xanthan gum 0.3 parts, urea 10 parts, glycerin 10 parts, A reversible thermochromic ink composition comprising 0.5 part of a nonionic penetrant imparting agent, 0.1 part of a modified silicone antifoaming agent, 0.2 part of a preservative, and 58.9 parts of water was prepared.
The reversible thermochromic ink composition was sucked and filled into a polypropylene pipe and connected to a ballpoint pen tip holding a 0.5 mm stainless steel ball at the tip through a resin holder.
Next, from the rear end of the polyprene pipe, an ink backflow prevention body (liquid stopper) having viscoelasticity mainly composed of polybutene is filled, and a tail plug is fitted to the rear part of the pipe. After the shaft cylinder was assembled and the cap was fitted, the deaeration process was performed by centrifugation to obtain a ballpoint pen.
In addition, SEBS rubber is attached to the rear portion of the rear shaft cylinder as a friction body.
An orange character (handwriting) was formed by writing on the paper surface using the ballpoint pen.
The handwriting has an orange color at room temperature (25 ° C.), and when the character is scraped with a friction body, the character is discolored and becomes colorless, and this state is maintained unless it is cooled to −15 ° C. or lower. I was able to.
When the paper surface was placed in a freezer and cooled to -15 ° C. or lower, the color changed to orange again, and the color change behavior could be reproduced repeatedly.

Application example 5
Preparation of Marking Pen 25.0 parts of reversible thermochromic microcapsule pigment prepared in Example 5 (previously cooled to −15 ° C. or less and colored orange), comb polymer dispersant [Nippon Lubrizol ( Co., Ltd., trade name: Solsperse 43000], 0.5 parts, organic nitrogen sulfur compound [made by Hokuko Chemical Co., Ltd., trade name: Hokuside R-150, 2-methyl-4-isothiazolin-3-one and 5- Mixture of chloro-2-methyl-4-isothiazolin-3-one] 1.0 part, 0.5 part polyvinyl alcohol, 35.0 parts glycerin, 0.02 part antifoaming agent, 37.98 parts water. Thus, a reversible thermochromic ink composition was obtained.
An ink occlusion body in which a polyester sliver is coated with a synthetic resin film is impregnated with the ink composition, and is accommodated in a shaft tube made of polypropylene resin, and a polyester fiber resin processing pen body (cannonball type) is held at the shaft tube tip A marking pen was obtained by assembling in a connected state via a cap and attaching a cap.
A SEBS resin is attached as a friction member 7 to the rear end portion of the shaft cylinder.
An orange character (handwriting) was formed by writing on the paper surface using the marking pen.
The handwriting has an orange color at room temperature (25 ° C.), and when the character is scraped with a friction body, the character is discolored and becomes colorless, and this state is maintained unless it is cooled to −15 ° C. or lower. I was able to.
When the paper surface was placed in a freezer and cooled to -15 ° C. or lower, the color changed to orange again, and the color change behavior could be reproduced repeatedly.

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

Claims (2)

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

(Wherein R ₁ represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, R 2 represents an alkyl group having 1 to 6 carbon atoms, and n represents an integer of 1 to 3)   A reversible thermochromic microcapsule pigment encapsulating the reversible thermochromic composition according to claim 1.

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