JP2007118197A - Reversible thermochromism microcapsule pigment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reversible thermochromism microcapsule pigment, the discoloring temperature of which can be finely adjusted and which has applicabilities over various fields such as indication of temperature, decoration, toys, instructional elements or the like. <P>SOLUTION: This reversible thermochromism microcapsule pigment contains (1) an electron donative colorable organic compound, (2) an electron acceptive compound, (3) a reacting medium to determine the starting temperature of the color reaction between (1) and (2) and (4) a specified discoloring temperature regulator. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reversible thermochromic microcapsule pigment. More specifically, the present invention relates to a microcapsule pigment encapsulating a composition that reversibly changes color with a temperature change.

Conventionally, a composition exhibiting reversible thermal discoloration that starts decoloring in the temperature rising process from the colored state, exhibits a completely decolored state above a specific temperature, starts color development in the subsequent temperature lowering process, and returns to the colored state. In connection with this, several proposals have been disclosed.
The composition can be roughly divided into two types. The first type changes color before and after the color change temperature, and there is only one specific state in the normal temperature range of both states before and after the color change. I can't. That is, the other state is maintained while the heat or cold necessary for the state to develop is applied, but when the heat or cold is not applied, the temperature returns to the original state exhibited in the normal temperature range. A reversible thermochromic composition that changes color with a relatively small hysteresis width (ΔH) with respect to the color density curve (see, for example, Patent Documents 1 and 2).
The second type is a temperature-color that changes color by following a very different path between when the temperature is raised from the lower temperature side than the color change temperature range and when the temperature is lowered from the higher temperature side than the color change temperature range. The low temperature side trigger is changed in the temperature range between the low temperature side trigger and the high temperature side trigger even after removing the heat or cold heat required for the color change with a large hysteresis width (ΔH) with respect to the density curve. This is a temperature-sensitive color-changing color memory composition capable of reversibly storing and holding the color changed by the following or higher temperature trigger (for example, see Patent Document 3).
The above-described composition exhibits a discoloration behavior as shown in the temperature-color density curve of FIG. 1 although the hysteresis width (ΔH) is different. The discoloration behavior is specified depending on (c) the reaction medium that determines the occurrence temperature of the color reaction between (a) the electron-donating color-forming organic compound and (b) the electron-accepting compound.
The compound (c) which is effective as the reaction medium (c) is limited in its type and is in a system to which an effective compound is applied, and there is no means for shifting the temperature-color density curve to the high temperature side, and the subtle color change temperature Adjustment was difficult and the intended discoloration characteristics were not always satisfied.
Therefore, an attempt has been made to slightly displace the temperature-color density curve by blending a specific compound as a color change temperature adjusting agent as the fourth component (see, for example, Patent Documents 4 to 6).
Japanese Patent Publication No. 51-44706 Japanese Patent Publication No. 1-29398 Japanese Patent Publication No. 4-17154 JP 2001-152041 A JP 2002-12787 A JP 2002-129055 A

  The present invention provides a reversible thermochromic microcapsule pigment using a new color-changing temperature adjusting agent that slightly displaces a temperature-color density curve, and exhibits temperature change, decoration, and toy having intended color-changing characteristics. Applicable to various fields such as teaching material elements.

（式中、Ｒ_１、Ｒ_２はそれぞれ炭素数６乃至２０の炭化水素基を示す。）

（式中、Ｒ_１、Ｒ_２はそれぞれ炭素数は４乃至２０の炭化水素基を示す。）

（式中、Ｒは炭素数４乃至２２の炭化水素基を示す。）

（式中、Ｒは炭素数６乃至２２の炭化水素基を示す。）

（式中、Ｒは炭素数８乃至２２の炭化水素基を示す。）

（式中、Ｒは炭素数１０乃至２４の炭化水素基を示し、Ｘは炭素数１０乃至２４のアルキルエーテル基を示す。）

（式中、Ｒ_１、Ｒ_２はそれぞれ炭素数１０乃至２６の炭化水素基を示す。）

（式中、Ｒは炭素数１０乃至２４の炭化水素基を示し、Ｘ、Ｙはそれぞれ水素原子、炭素数１乃至４のアルキル基、炭素数１乃至４のアルキルエーテル基、又は、ハロゲンを示し、ｎ、ｍはそれぞれ１乃至３の整数を示す。）

更には、前記（ニ）変色温度調整剤が、（ハ）反応媒体１重量部に対して０．０１〜０．３重量部含まれること、マイクロカプセル顔料の粒子径が０．０１乃至６μｍの範囲にあること、温度−色濃度曲線に関して５℃以下のヒステリシス幅（ΔＨ）を示して変色すること等を要件とする。 The present invention includes (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, (c) a reaction medium that determines the temperature at which the color reaction of (a) and (b) occurs, and ( (D) The discoloration temperature adjusting agent is contained as essential four components, and (d) the discoloration temperature adjusting agent is a compound selected from the following general formulas (1) to (9), and the essential four components are encapsulated in microcapsules. And reversible thermochromic microcapsule pigment.

(In the formula, R ₁ and R ₂ each represent a hydrocarbon group having 6 to 20 carbon atoms.)

(In the formula, R ₁ and R ₂ each represent a hydrocarbon group having 4 to 20 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 4 to 22 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 6 to 22 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 8 to 22 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 10 to 24 carbon atoms, and X represents an alkyl ether group having 10 to 24 carbon atoms.)

(In the formula, R ₁ and R ₂ each represent a hydrocarbon group having 10 to 26 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 10 to 24 carbon atoms, and X and Y represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl ether group having 1 to 4 carbon atoms, or a halogen, respectively. , N, and m are each an integer of 1 to 3.)

Further, (d) the discoloration temperature adjusting agent is contained in (c) 0.01 to 0.3 parts by weight with respect to 1 part by weight of the reaction medium, and the particle size of the microcapsule pigment is 0.01 to 6 μm. It is a requirement to be in the range, to change color by showing a hysteresis width (ΔH) of 5 ° C. or less with respect to the temperature-color density curve.

INDUSTRIAL APPLICABILITY The present invention can provide a reversible thermochromic microcapsule pigment capable of finely adjusting the color change temperature, and has applicability in various fields such as temperature display, decoration, toys, and learning elements.
In addition, microcapsule pigments with small particle diameters are excellent in thermal discoloration functions that produce a sharp color as well as fine-tuning the discoloration temperature, so they can be applied to writing instrument inks, spray inks, and process printing inks with high mesh resolution. It is possible to provide a reversible thermochromic microcapsule pigment that can be applied to various fields such as gravure ink.

The hysteresis characteristics in the color density-temperature curve of the reversible thermochromic microcapsule pigment will be described in detail below.
In FIG. 1, the vertical axis represents color density and the horizontal axis represents temperature. The change in color density due to the temperature change proceeds along the arrow. Here, A is a point indicating the density at the lowest temperature T ₄ (hereinafter referred to as the complete color erasing temperature) reaching the complete color erasing state, and B is the maximum temperature T ₃ (hereinafter referred to as the color erasing state) that can maintain the complete color erasing state. C is a point indicating a density at a minimum temperature T ₂ (hereinafter referred to as a color development start temperature) at which a completely decolored state can be maintained, and D is a completely colored state. the maximum temperature T _{1 (hereinafter,} referred to as complete coloring temperature) to reach a point showing the density at.
At temperatures T _A in a state in which two phases of the color development state E point and the decolored state point F coexist, including the temperature T _A, the temperature range of the color development state and decolored state can coexist can hold discoloration A temperature range in which the length of the line segment EF is a scale indicating the discoloration contrast, and the length of the line segment HG passing through the midpoint of the line segment EF indicates the degree of hysteresis (hereinafter referred to as hysteresis width ΔH). When this ΔH value is small (less than 5 ° C.), only one specific state can exist in the normal temperature range among both states before and after the color change. Further, when the ΔH value is large (5 ° C. to 80 ° C.), it is easy to maintain each state before and after the color change.
In particular, a reversible thermochromic composition having a small ΔH value (less than 5 ° C.) is used for applications such as indicators because of its color change characteristics, and adjustment of the color change temperature is important.

The present invention resides in that the discoloration point can be finely adjusted by shifting the discoloration point on the low temperature side to the high temperature side by blending the compound selected from the general formulas (1) to (9) as the component (d).
Explaining this point, by blending component (d), T1 (complete color development temperature) and T2 (color development start temperature) are shifted to the high temperature side as shown by the broken lines in the color density-temperature curve of FIG. .
The shifting temperature can be arbitrarily adjusted depending on the component (d), that is, the type and amount of the color change temperature adjusting agent.

Further, the reversible thermochromic composition is used as a reversible thermochromic microcapsule pigment encapsulated in a microcapsule in order to obtain a chemically and physically stable reversible thermochromic material. When a product is encapsulated in a microcapsule, depending on the particle size distribution of the capsule particle diameter, a color tone change due to a temperature change, particularly a color development behavior when the temperature is lowered, may be defective.
In the production of the microcapsule pigment, although the microcapsule pigment has a particle diameter of about 1 to 50 μm, preferably 1 to 30 μm, although it varies depending on the application, the particle diameter varies. However, not all microcapsule pigments have a particle size in the above-mentioned range, and there are microcapsule pigments having a particle size larger or smaller than that. A microcapsule pigment having a particle size of about 0.01 to 3 μm can be applied to process printing inks and inks for writing instruments by high mesh decomposition. However, since (c) component has supercooling properties, FIG. As shown by the solid line of the color density-temperature curve, the encapsulated composition has the same composition, but the temperature of the microcapsule pigment having a particle size larger than that is 2 to 2 It shifts to a low temperature of 30 ° C. or develops color step by step and does not show a sharp discoloration, and it is difficult to obtain the original discoloration characteristics.
However, by incorporating the component (d) in the microcapsule pigment having a small particle diameter, the cloud point of the reversible thermochromic composition is increased, and the crystallinity of the composition itself is improved. ) color density of suppressing supercooling components Figure 3 - T _{1 (complete} coloring temperature as indicated by the dashed temperature curve) and T _{2 (sensitive} color development with color initiation temperature) is shifted to the high temperature side Good color development behavior.
In the discoloration temperature adjusting agent previously proposed by the present applicant, T ₁ (complete color development temperature) and T ₂ (color development start temperature) are on the high temperature side as shown by the broken lines in the color density-temperature curve of FIG. The color development behavior shows a good color development behavior that shifts to a sharp color and sharply develops color, but when used in applications where the temperature is further increased by 30 ° C. or more from the complete decolorization temperature (T ₄ ), the temperature at which the color develops again due to the temperature decrease after heating is Although there was a problem of shifting to a temperature lower by 2 to 30 ° C. than usual, the reversible thermochromic composition containing the component (d) of the present invention can remarkably improve the crystallinity of the composition itself. Therefore, even when heating at 30 ° C. or higher from the complete decoloring temperature (T ₄ ), the supercoolability of the component (c) is suppressed, and T ₁ as shown by the broken line in the color density-temperature curve of FIG. (complete coloring temperature) and T _{2 (coloring} starting temperature) is shifted to the high temperature side It is possible to maintain permanently a favorable coloring behavior together sensitive color development.

The component (d) will be described.
Examples of the compound represented by the general formula (1) are shown below.

  Examples of the compound represented by the general formula (2) are shown below.

  Examples of the compound represented by the general formula (3) are shown below.

  Examples of the compound represented by the general formula (4) are shown below.

  Examples of the compound represented by the general formula (5) are shown below.

  Examples of the compound represented by the general formula (6) are shown below.

  Examples of the compound represented by the general formula (7) are shown below.

  Examples of the compound represented by the general formula (8) are shown below.

The (d) discoloration temperature adjusting agent is blended in an amount of 0.01 to 0.3 parts by weight, preferably 0.01 to 0.2 parts by weight, based on 1 part by weight of the component (c).
If the amount is less than 0.01 part by weight, it is difficult to achieve a desired color change temperature adjustment effect. If the amount exceeds 0.3 part by weight, the discoloration sensitivity is easily impaired, and it is difficult to exhibit a sharp discoloration behavior.

Examples of the (i) electron donating color-forming organic compound include conventionally known diphenylmethane phthalides, phenyl indolyl phthalides, indolyl phthalides, diphenyl methane azaphthalides, phenyl indolyl azaphthalides , Fluorans, stylinoquinolines, diazarhodamine lactones, etc., and these compounds are exemplified below.
3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, 3,3 -Bis (1-n-butyl-2-methylindol-3-yl) phthalide, 3,3-bis (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3- [2-ethoxy-4- ( N-ethylanilino) phenyl] -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3,6-dimethoxyfluorane, 3,6-di-n-butoxyfluorane, 2- Methyl-6- (N-ethyl-Np-tolylamino) fluorane, 3-chloro-6-cyclohexylaminofluorane, 2-methyl-6-cyclohexylaminofluora 2- (2-chloroanilino) -6-di-n-butylaminofluorane, 2- (3-trifluoromethylanilino) -6-diethylaminofluorane, 2- (N-methylanilino) -6- (N -Ethyl-Np-tolylamino) fluorane, 1,3-dimethyl-6-diethylaminofluorane, 2-chloro-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-diethylaminofluorane 2-anilino-3-methyl-6-di-n-butylaminofluorane, 2-xylidino-3-methyl-6-diethylaminofluorane, 1,2-benz-6-diethylaminofluorane, 1,2- Benz-6- (N-ethyl-N-isobutylamino) fluorane, 1,2-benz-6- (N-ethyl-N-isoamylamino) Ruoran, 2- (3-methoxy-4-de deco carboxymethyl styryl) quinoline,
Spiro [5H- (1) benzopyrano (2,3-d) pyrimidine-5,1 '(3'H) isobenzofuran] -3'-one, 2- (diethylamino) -8- (diethylamino) -4-methyl −,
Spiro [5H- (1) benzopyrano (2,3-d) pyrimidine-5,1 '(3'H) isobenzofuran] -3'-one, 2- (di-n-butylamino) -8- (di -N-butylamino) -4-methyl-,
Spiro [5H- (1) benzopyrano (2,3-d) pyrimidine-5,1 '(3'H) isobenzofuran] -3'-one, 2- (di-n-butylamino) -8- (diethylamino) ) -4-methyl-,
Spiro [5H- (1) benzopyrano (2,3-d) pyrimidine-5,1 '(3'H) isobenzofuran] -3'-one, 2- (di-n-butylamino) -8- (N -Ethyl-Ni-amylamino) -4-methyl-,
Spiro [5H- (1) benzopyrano (2,3-d) pyrimidine-5,1 '(3'H) isobenzofuran] -3'-one, 2- (di-n-butylamino) -8- (di -N-butylamino) -4-phenyl and the like.
Furthermore, there can be mentioned pyridine-based, quinazoline-based, bisquinazoline-based compounds and the like that are effective in developing fluorescent yellow to red color development.

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., phenol-aldehyde condensation resin etc., such as a bis type and a tris type phenol, 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 butyl catechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, 4- (4- (1- Methylethoxyphenyl) sulfonylphenol, 4- (4-butyloxyphenyl) sulfonylphenol, 4- (4-pentyloxyphenyl) sulfonylphenol, 4- (4-hexyloxyphenyl) sulfonylphenol, 4- (4-heptyloxy) Phenyl) sulfonylphenol, 4- (4-octyloxyphenyl) sulfonylphenol, n-butyl p-hydroxybenzoate, n-octyl p-hydroxybenzoate, resorcin, dodecyl gallate,
2,2-bis (4'-hydroxyphenyl) propane,
4,4-dihydroxydiphenyl sulfone,
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-methylbutane,
1,1-bis (4′-hydroxyphenyl) -2-methylpropane,
1,1-bis (4′-hydroxyphenyl) n-hexane,
1,1-bis (4′-hydroxyphenyl) n-heptane,
1,1-bis (4′-hydroxyphenyl) n-octane,
1,1-bis (4′-hydroxyphenyl) n-nonane,
1,1-bis (4′-hydroxyphenyl) n-decane,
1,1-bis (4′-hydroxyphenyl) n-dodecane,
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,
2,2-bis (4'-hydroxyphenyl) n-nonane, and the like.
The compounds having a phenolic hydroxyl group can exhibit the most effective thermochromic properties, but their metal salts, aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms and their metal salts, carboxylic acids It may be a compound selected from acid metal salts, acidic phosphate esters and metal salts thereof, 1,2,3-triazole and derivatives thereof.
Furthermore, a fluoroalcohol compound can also be used, and is exemplified below.
2-hydroxyhexafluoroisopropylbenzene,
1,3-bis (2-hydroxyhexafluoroisopropyl) benzene,
1,4-bis (2-hydroxyhexafluoroisopropyl) benzene,
1,3-bis (2-hydroxymethyl-hexafluoroisopropyl) benzene,
1,3-bis (3-hydroxy-1,1-bistrifluoromethylpropyl) benzene,
1,4-bis (2-hydroxymethyl-hexafluoroisopropyl) benzene,
1,4-bis (3-hydroxy-1,1-bistrifluoromethylpropyl) benzene,
2-hydroxymethyl-hexafluoroisopropylbenzene,
3-hydroxy-1,1-bistrifluoromethylpropylbenzene, and the like.

The composition comprising the two components (a) and (b) of the reversible thermochromic composition of the present invention can also obtain reversible heating color developability, but there is a limitation in adjusting the color change temperature, By using the component (c), the discoloration temperature can be practically adjusted.
(C) Compounds that are reaction media for reversibly causing the electron transfer reaction in (a) and (b) above in a specific temperature range include hydrocarbons, halogenated hydrocarbons, sulfides, ethers, and ketones. Conventionally, general-purpose reaction media such as alcohols, esters, acid amides, alcohols, waxes and the like are all effective, and they may be semi-liquid substances such as medium molecular weight polymers, and are one kind of these compounds. Or 2 or more types can be applied. When the above compounds are used for microencapsulation and secondary processing, those having a low molecular weight evaporate out of the capsule system when subjected to a high heat treatment. The above compounds are effective.

  Examples of the sulfides include di-n-octyl sulfide, di-n-nonyl sulfide, di-n-decyl sulfide, di-n-dodecyl sulfide, di-n-tetradecyl sulfide, di-n-hexadecyl sulfide, di- -N-octadecyl sulfide, octyldodecyl sulfide, diphenyl sulfide, dibenzyl sulfide, ditolyl sulfide, diethylphenyl sulfide, dinaphthyl sulfide, 4,4'-dichloro-diphenyl sulfide, 2,4,5,4'-tetrachloro -A diphenyl sulfide etc. can be illustrated.

  Examples of ethers include aliphatic ethers having a total carbon number of 10 or more, such as dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecyl ether, diundecyl ether, didodecyl ether, ditridecyl ether. Ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, dioctadecyl ether, decanediol dimethyl ether, undecane diol dimethyl ether, dodecane diol dimethyl ether, tridecane diol dimethyl ether, decane diol diethyl ether, undecane diol diethyl ether, and the like. Examples of alicyclic ethers include s-trioxane. Examples of aromatic ethers include phenyl ether, benzyl phenyl ether, dibenzyl ether, di-p-tolyl ether, 1-methoxynaphthalene, 3,4,5-trimethoxytoluene and the like.

Examples of ketones include aliphatic ketones having a total carbon number of 10 or more, for example, 2-decanone, 3-decanone, 4-decanone, 2-undecanone, 3-undecanone, 4-undecanone, 5-undecanone, and 6-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.
Arylalkyl ketones having 12 to 24 carbon atoms in total, such as n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradecanophenone, 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-pentylacetophenone, Black hexyl phenyl ketone, benzyl -n- butyl ketone, 4-n-butyl acetophenone, n- hexanophenone, 4-isobutyl acetophenone, 1-acetonaphthone, 2-acetonaphthone, cyclopentyl phenyl ketone.
Aryl aryl ketones such as benzophenone, benzyl phenyl ketone, dibenzyl ketone and the like. Alicyclic ketones such as cyclooctanone, cyclododecanone, cyclopentadecanone, 4-tert-butylcyclohexanone and the like can be exemplified.

  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, stearyl caprate, docosyl caprate, 2-ethylhexyl laurate, lauric N-decyl acid, 3-methylbutyl myristate, cetyl myristate, isopropyl palmitate, neopentyl palmitate, nonyl palmitate, cyclohexyl palmitate, n-butyl stearate, 2-methylbutyl stearate, 3,5,5 stearates -Trimethylhexyl, n-undecyl stearate, pentadecyl stearate, stearyl stearate, cyclohexylmethyl stearate, isopropyl behenate, hexyl behenate, lauryl behenate, behenyl behenate, cetyl benzoate, p-tert-butylbenzoic acid Stearyl, dimyristyl phthalate, distearyl phthalate, dimyristyl oxalate, dicetyl oxalate, dicetyl malonate, dilauryl succinate, dilauryl glutarate, diuric adipate Decyl, dilauryl azelate, di- (n-nonyl) sebacate, dineopentyl 1,18-octadecylmethylenedicarboxylate, ethylene glycol dimyristate, propylene glycol dilaurate, propylene glycol distearate, hexylene glycol dipalmitate, 1 , 5-pentanediol dimyristate, 1,2,6-hexanetriol trimyristate, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanedimethanol dimyristate, xylene glycol dicaprinate, xylene glycol di Examples include stearate.

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 Ruoctyl, 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, behenyl butyrate, etc. it can.

  Furthermore, the carboxylic acid ester compound disclosed in Japanese Patent Publication No. 4-17154, for example, a carboxylic acid ester containing a substituted aromatic ring in the molecule, a carboxylic acid containing an unsubstituted aromatic ring, and an aliphatic having 10 or more carbon atoms Esters of alcohol, carboxylic acid ester having a cyclohexyl group in the molecule, fatty acid having 6 or more carbon atoms and unsubstituted aromatic alcohol or phenol, fatty acid having 8 or more carbon atoms and branched aliphatic alcohol or ester, dicarboxylic acid and aromatic Esters of aliphatic or branched aliphatic alcohols, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, dimyristin , Distearin And the like.

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-underci eicosanoate, n-tridecyl eicosanoate, n-pentadecyl eicosanoate, n-nonyl behenate, n-behenate Examples include undecyl, n-tridecyl behenate, and n-pentadecyl behenate.

  Alcohols include aliphatic monovalent saturated alcohols such as decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, heptadecyl alcohol, octadecyl alcohol, eicosyl. Alcohol, docosyl alcohol, etc. Aliphatic unsaturated alcohols such as allyl alcohol and oleyl alcohol. Alicyclic alcohols such as cyclopentanol, cyclohexanol, cyclooctanol, cyclododecanol, 4-tert-butylcyclohexanol and the like. Aromatic alcohols such as 4-methylbenzyl alcohol, benzhydrol and the like. Examples include polyhydric alcohols such as polyethylene glycol.

Examples of acid amides include the compounds shown below.
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 anilide, capric anilide, lauric anilide, myristic anilide, palmitic anilide, stearic anilide, behenic anilide, oleic anilide, erucic anilide, caproic acid N-methylamide, caprylic N -Methylamide, capric acid N-methylamide, lauric acid N-methylamide, myristic acid N-methylamide, palmitic acid N-methylamide, stearic acid N-methylamide, behenic acid N-methyl Amide, oleic acid N-methylamide, erucic acid N-methylamide, lauric acid N-ethylamide, myristic acid N-ethylamide, palmitic acid N-ethylamide, stearic acid N-ethylamide, oleic acid N-ethylamide, lauric acid N-butylamide, Myristic acid N-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-octyl Amide, oleic acid N-octylamide, lauric acid N-dodecylamide, myristic acid N-dodecylamide, palmitic acid N-dodecylamide, stearic acid N-dodecylamide, oleic acid N-dodecylamide, Lauric 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-butylamide, glutaric acid N-butyramide, malonic acid N-butyramide, adipic acid N-octylamide, adipic acid N-dodecylamide and the like.

A reversible thermochromic composition can be obtained by including the essential four components consisting of the components (a), (b), (c) and (d) described above.
The mixing ratio of the components (A), (B), and (C) depends on the concentration, the color change temperature, the color change form, and the type of each component, but generally the component ratio that provides the desired color change characteristics. Is (B) component 0.1 to 50, preferably 0.5 to 20, (C) component 1 to 800, preferably 5 to 200 (the ratio is All are parts by weight).

In order to prevent photodegradation of the reversible thermochromic composition, the light stabilizer can be contained in an amount of 0.3 to 24 parts by weight, preferably 0.8 to 16 parts by weight.
Examples of the light stabilizer include ultraviolet absorbers, antioxidants, carotenes, dyes, amines, phenols, nickel complexes, sulfides that prevent photodegradation caused by the excited state due to the photoreaction of component (a). Examples thereof include singlet oxygen quenchers such as superoxide anion quenchers such as complexes of oxide dismutase and cobalt and nickel, and compounds that suppress oxidation reactions such as ozone quenchers.

The reversible thermochromic composition described above is encapsulated in microcapsules and used as a microcapsule pigment. Thereby, the reversible thermochromic composition can be maintained in the same composition under various use conditions, and a chemically and physically stable pigment can be constituted, and the same effects can be achieved.
The microencapsulation includes conventionally known interfacial polymerization method, in situ polymerization method, in-liquid curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent, melt dispersion cooling method, air suspension coating Method, spray drying method, etc., 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.
When the reversible thermochromic composition is encapsulated in the microcapsule, the light stabilizer may be encapsulated in the microcapsule together with the reversible thermochromic composition, or used when applied as a coloring material. It can also be added to the vehicle. In addition, the light stabilizer can be encapsulated in a microcapsule and added to the vehicle.

The reversible thermochromic microcapsule pigment of the present invention can be conventionally obtained by a general-purpose microencapsulation means, and can be dispersed in various vehicles to obtain printed matter or coated matter in the form of printing ink or paint. Also, various molded products can be obtained by blending with a molding resin and using a general-purpose molding means.
Furthermore, it can be dispersed in a wax-like or paste-like medium to form a color material.
In addition, a color change can be diversified by using together a non-thermochromic dye or a pigment suitably.

Examples are shown below, but the present invention is not limited to the examples.
Example 1
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (B) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol (4.0 parts by weight), (ha) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) component (compound 1-5) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol water solution Emulsified and dispersed in the liquid.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 2
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (b) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol (4.0 parts by weight), (ha) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) component (compound 2-5) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol water solution It was emulsified and dispersed in the medium.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 3
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (B) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol (4.0 parts by weight), (ha) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) component (compound 3-7) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol water solution Emulsified and dispersed in the liquid.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 4
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (B) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol (4.0 parts by weight), (ha) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) component (compound 4-7) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol water solution Emulsified and dispersed in the liquid.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 5
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (B) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol 4.0 parts by weight, (ha) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) component (compound 5-5) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol water solution Emulsified and dispersed in the liquid.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 6
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (B) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol (4.0 parts by weight), (ha) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) component (compound 6-6) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol water solution Emulsified and dispersed in the liquid.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 7
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (b) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol (4.0 parts by weight), (ha) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) component (compound 6-11) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol It was emulsified and dispersed in the solution.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 8
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (B) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol 4.0 parts by weight, (ha) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) component (compound 7-7) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol water solution Emulsified and dispersed in the liquid.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 9
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (B) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol 4.0 parts by weight, (c) As component (25.0 parts by weight) stearyl laurate, 25.0 parts by weight stearyl caprate (d) component (compound 8-5) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol water solution Emulsified and dispersed in the liquid.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 10
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (B) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol 4.0 parts by weight, (ha) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) component (compound 8-11) 3.0 A reversible thermochromic composition composed of parts by weight is uniformly heated and dissolved, and 8% of a solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent are mixed as a wall film material. Polyvinyl alcohol water Emulsified and dispersed in the solution.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 11
(I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine-5,1 '(3'H)- Isobenzofuran] -3-one 2.0 parts by weight, (b) 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane- 1,1-diyl) diphenol 4.0 parts by weight, (c) 25.0 parts by weight of stearyl laurate, 25.0 parts by weight of stearyl caprate, (d) 3.0 parts by weight of component (compound 9) A reversible thermochromic composition consisting of the following is uniformly heated and dissolved, and a solution prepared by mixing 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 50.0 parts by weight of a cosolvent as a wall film material is mixed with 8% polyvinyl alcohol. Aqueous solution In was emulsified and dispersed.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 3.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from pink to colorless.

Example 12
(I) 3- [2-Ethoxy-4- (N-ethylanilino) phenyl] -3- (1-ethyl-2-methyl-3-indolyl) -4-azaphthalide as a component, 3.0 parts by weight, (B) As components, 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 4.0 parts by weight, 4,4 '-(2-ethylhexane-1,1-diyl) diphenol 4.0 parts by weight, A reversible thermochromic composition comprising 50.0 parts by weight of nonyl palmitate as a component) and 3.0 parts by weight of component (d) (compound 2-6) as a component is uniformly heated and dissolved. A solution prepared by mixing 30.0 parts by weight of a polyvalent isocyanate prepolymer and 50.0 parts by weight of a co-solvent was emulsified and dispersed in an 8% aqueous polyvinyl alcohol solution.
At the time of emulsification, the stirring force of the homomixer is adjusted so that the particle diameter becomes 2.0 μm. After emulsification, stirring is continued for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Further, stirring was continued for 6 hours to obtain a reversible thermochromic microcapsule pigment suspension.
The microcapsule pigment was isolated by centrifuging the reversible thermochromic microcapsule pigment suspension. The microcapsule pigment exhibits a reversible thermochromic property from blue to colorless.

Comparative Example 1
A microcapsule pigment was obtained by the same method except that the component (2) was removed from Example 1.

Comparative Example 2
A microcapsule pigment was obtained in the same manner except that the component (2) was removed from Example 12.

Preparation of test samples Specified on high-quality paper by screen printing using reversible thermochromic ink in which 40 parts by weight of the microcapsule pigments obtained in Examples 1 to 12 and Comparative Examples 1 and 2 were dispersed in an ethylene-vinyl acetate emulsion A test sample was obtained by printing a circle of size.

Discoloration temperature measurement The test sample is set in a predetermined position of a color difference meter [TC-3600 type color difference type, manufactured by Tokyo Denshoku Co., Ltd.], heated and cooled at a rate of 10 ° C./min at a temperature range of 70 ° C. The color density at each temperature was measured.

The following table shows the particle size of the reversible thermochromic microcapsule pigment used for each test sample, T ₁ (complete color development temperature), T ₂ (color development start temperature), T ₃ (decoloration start temperature), T ₄ (complete Erasing temperature) and ΔH (hysteresis width).

Hereinafter, the color change temperatures of Examples and Comparative Examples will be described with reference to schematic diagrams.
As for the discoloration temperature characteristic of the microcapsule pigment encapsulating the reversible thermochromic composition of Example 1, the hysteresis width (ΔH) is narrowed by 8.0 ° C. as compared with Comparative Example 1, and the discoloration temperature curve as shown in FIG. Show.
As for the discoloration temperature characteristic of the microcapsule pigment encapsulating the reversible thermochromic composition of Example 2, the hysteresis width (ΔH) is 9.5 ° C. narrower than that of Comparative Example 1, and the discoloration temperature curve as shown in FIG. Show.
The microcapsule pigment encapsulating the reversible thermochromic composition of Example 3 has a hysteresis temperature (ΔH) of 8.0 ° C. narrower than that of Comparative Example 1, and a discoloration temperature curve as shown in FIG. Show.
The microcapsule pigment encapsulating the reversible thermochromic composition of Example 4 has a hysteresis temperature (ΔH) of 8.5 ° C. narrower than that of Comparative Example 1, and a color change temperature curve as shown in FIG. Show.
As for the discoloration temperature characteristic of the microcapsule pigment encapsulating the reversible thermochromic composition of Example 5, the hysteresis width (ΔH) is narrowed by 7.5 ° C. as compared with Comparative Example 1, and the discoloration temperature curve as shown in FIG. Show.
As for the discoloration temperature characteristic of the microcapsule pigment encapsulating the reversible thermochromic composition of Example 6, the hysteresis width (ΔH) is 9.5 ° C. narrower than that of Comparative Example 1, and the discoloration temperature curve as shown in FIG. Show.
The microcapsule pigment encapsulating the reversible thermochromic composition of Example 7 has a hysteresis temperature (ΔH) of 8.0 ° C. narrower than that of Comparative Example 1, and a discoloration temperature curve as shown in FIG. Show.
The microcapsule pigment encapsulating the reversible thermochromic composition of Example 8 has a hysteresis width (ΔH) of 6.5 ° C. narrower than that of Comparative Example 1, and a discoloration temperature curve as shown in FIG. Show.
As for the discoloration temperature characteristic of the microcapsule pigment encapsulating the reversible thermochromic composition of Example 9, the hysteresis width (ΔH) is 8.5 ° C. narrower than that of Comparative Example 1, and the discoloration temperature curve as shown in FIG. Show.
As for the discoloration temperature characteristic of the microcapsule pigment containing the reversible thermochromic composition of Example 10, the hysteresis width (ΔH) is 8.5 ° C. narrower than that of Comparative Example 1, and the discoloration temperature curve as shown in FIG. Show.
As for the discoloration temperature characteristic of the microcapsule pigment encapsulating the reversible thermochromic composition of Example 11, the hysteresis width (ΔH) is 10.0 ° C. narrower than that of Comparative Example 1, and the discoloration temperature curve as shown in FIG. Show.
As for the discoloration temperature characteristic of the microcapsule pigment encapsulating the reversible thermochromic composition of Example 12, the hysteresis width (ΔH) is narrowed by 7.0 ° C. as compared with Comparative Example 1, and the discoloration temperature curve as shown in FIG. Show.

It is explanatory drawing which shows the temperature-color density curve of the microcapsule pigment which included the reversible thermochromic composition. It is description which shows the temperature-color density curve of the reversible thermochromic microcapsule pigment of this invention which shifted the low temperature side discoloration point of the conventional microcapsule pigment to the high temperature side. It is description which shows the temperature-color density curve of the reversible thermochromic microcapsule pigment of this invention which shifted the low temperature side discoloration point of the conventional microcapsule pigment with a small particle diameter to the high temperature side.

Explanation of symbols

T ₁ complete coloring temperature T ₂ color initiation temperature T ₃ decoloring starting temperature T ₄ complete decoloring temperature T the temperature of the midpoint in color density at a temperature T _G decoloring process of the midpoint in color density in the _H coloring process ΔH hysteresis width _(T G _-T H)

Claims (4)

(A) an electron-donating color-forming organic compound, (b) an electron-accepting compound, (c) a reaction medium for determining the temperature at which the color reaction of (a) and (b) occurs, and (d) a color change temperature. Reversible thermal discoloration comprising a modifier as essential four components, wherein the (d) discoloration temperature regulator is a compound selected from the following general formulas (1) to (9), and the essential four components are encapsulated in microcapsules: Microcapsule pigment.

(In the formula, R ₁ and R ₂ each represent a hydrocarbon group having 6 to 20 carbon atoms.)

(In the formula, R ₁ and R ₂ each represent a hydrocarbon group having 4 to 20 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 4 to 22 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 6 to 22 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 8 to 22 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 10 to 24 carbon atoms, and X represents an alkyl ether group having 10 to 24 carbon atoms.)

(In the formula, R ₁ and R ₂ each represent a hydrocarbon group having 10 to 26 carbon atoms.)

(In the formula, R represents a hydrocarbon group having 10 to 24 carbon atoms, and X and Y represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl ether group having 1 to 4 carbon atoms, or a halogen, respectively. , N, and m are each an integer of 1 to 3.)

  The reversibly thermochromic microcapsule pigment according to claim 1 or 2, wherein the (d) discoloration temperature adjusting agent is contained in an amount of 0.01 to 0.3 parts by weight with respect to 1 part by weight of the reaction medium.   The reversible thermochromic microcapsule pigment according to claim 1 or 2, wherein the particle diameter is in the range of 0.01 to 6 µm.   The reversible thermochromic microcapsule pigment according to any one of claims 1 to 3, which changes color by exhibiting a hysteresis width (ΔH) of 5 ° C or less with respect to a temperature-color density curve.

Images