JP2013233810A - Sealing type reversible thermal discolorable indicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing type reversible thermal discolorable indicator in which color fastness to light is remarkably improved, the discoloration function of a reversible thermal discoloration layer can be lasted over a long period, and the thermal discoloration function of a reversible thermal discolorable indicator repeatedly performing color developing and reducing can be maintained over a long period of time.SOLUTION: A sealing type reversible thermal discolorable indicator 1 is obtained by enclosing, in an oxygen low permeable sealing body 4 in which at least an indication face has transparency: a reversible thermal discolorable indicator 2 which is provided, on a supporting body 21, with a reversible thermal discoloration layer 22 including a reversible thermal discolorable material at least made of (a) an electron-donative coloration-type organic compound, (b) an electron-acceptive compound and (c) a reaction medium controlling the color reactions of the (a) and (b); an oxygen absorber 3; and an oxygen detecting agent capable of visually recognizing oxygen concentration.

Description

  The present invention relates to an encapsulated reversible thermochromic display. More specifically, the present invention relates to a reversible thermochromic display body in which a display body on which an image is formed by applying a heating or cooling device is enclosed.

Conventionally, as a reversible thermochromic display capable of forming an image by application of heat or cold, (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, (c) the above-mentioned (a), ( A word processor paper for test printing provided with a reversible thermochromic layer containing a reversible thermochromic composition composed of a compound that is a reaction medium that reversibly causes an electron transfer reaction in (b) is disclosed (for example, Patent Document 1). reference).
Since the test printing word processor paper can selectively hold either the colored state or the decolored state in the normal temperature range, it is necessary to improve the light fastness in the colored state and the decolored state, respectively.
Among them, with regard to improving the light resistance in the decolored state, an attempt has been made to prevent the occurrence of a residual color such as browning by blending an ultraviolet absorber (see, for example, Patent Document 2), but the light resistance in the colored state. There is no effective means for improvement, and it has been difficult to prevent a decrease in color density during color development.
Furthermore, the reversible thermochromic material that changes color by an electron transfer reaction between the electron-donating color-forming organic compound and the electron-accepting compound is greatly related to the presence of oxygen in the process of photodegradation. When it was irradiated with light in an atmosphere, it was easy to deteriorate, and the decrease in color density during color development was remarkable.

Japanese Utility Model Publication No. 6-36862 Japanese Patent Publication No. 4-18543

  The present invention focuses on the presence of oxygen involved in photodegradation of a display using a reversible thermochromic material that changes color by an electron transfer reaction between an electron-donating color-forming organic compound and an electron-accepting compound. In the low oxygen atmosphere, the present invention was completed by obtaining the knowledge that the light resistance hardly deteriorates even when irradiated with light and that the light resistance can be remarkably improved if oxygen can be excluded.

The present invention controls at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) controlling the color reaction of (a) and (b) above. A reversible thermochromic display body provided with a reversible thermochromic layer comprising a reversible thermochromic material comprising a reaction medium, an oxygen absorber, and an oxygen detector capable of visually recognizing oxygen concentration, at least on the display surface is transparent An encapsulated reversible thermochromic display body that is sealed in an oxygen low-permeability inclusion body having the property is required.
Furthermore, the reversible thermochromic material comprises (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) controlling the color reaction of (a) and (b). A reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising a reaction medium, which exhibits a large hysteresis characteristic with respect to a color density-temperature curve, and exhibits a mutual relationship between the first hue and the second hue. In the process of exhibiting degeneration and increasing the temperature in the first hue, when the temperature reaches t ₃ , the first hue starts to change color and is completely in the second hue at a temperature range higher than temperature t ₃ and higher than temperature t _4. next, in the process of temperature in the second color state is lowered, when the reached temperature t ₂ less than the temperature t _3, the second color begins to discolor at a low temperature t ₁ the following temperature range than the temperature t ₂ become completely the first color, the temperature t ₂ Shows the hysteresis characteristic in which the first color or the second color temperature region is maintained between the temperature t _3, the temperature t ₁ is the temperature of 0 ℃ or less, the temperature t ₄ is a temperature above 50 ° C., Changing the color density-temperature curve with a hysteresis width (ΔH) of 40 ° C. to 100 ° C., changing the color density-temperature curve with a hysteresis width (ΔH) of 40 ° C. to 100 ° C., the oxygen The oxygen permeability of the low-permeability inclusion body is 70 ml / m ² · day · atm or less, the oxygen absorber contains iron powder having reducibility, and the reversible thermochromic display body is reversible. An ultraviolet absorber is contained in the thermochromic layer or in the oxygen low-permeability inclusion body, and a UV absorber is contained on the reversible thermochromic layer of the reversible thermochromic display body or on the surface of the oxygen low-permeability inclusion body. Providing a layer, said A male-female occlusion type chuck is provided in the opening of the oxygen low-permeability inclusion body, a plurality of reversible thermochromic display bodies are enclosed in the oxygen low-permeability inclusion body, and the oxygen low-permeability display body It is required that an irreversible thermochromic display is enclosed in a porous enclosure, and that the oxygen detector is an oxygen detector and oxygen absorber integrated with an oxygen absorber.

  The present invention remarkably improves the light fastness, can last the color changing function of the reversible thermochromic layer, and maintains the heat discoloration function of the reversible thermochromic display which repeats color development and decoloration for a long period of time. Therefore, it is possible to provide a sealed reversible thermochromic display useful as an advertising medium or a decorative element.

It is explanatory drawing which shows the discoloration behavior of the reversible thermochromic composition which has color erasability of a heating decoloring type. It is explanatory drawing which shows the discoloration behavior of a heat coloring type reversible thermochromic composition. It is explanatory drawing which shows one Example of the enclosure type reversible thermochromic display body of this invention.

The reversible thermochromic display will be described.
The reversible thermochromic display is provided on a support with at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) the above-mentioned (a) and (b). A reversible thermochromic layer containing a reversible thermochromic material comprising a reaction medium for controlling the color reaction is provided.
As the reversible thermochromic material, a reversible thermochromic composition having a color erasability of heating and decoloring type is effective, and the hysteresis characteristic in the color density-temperature curve of the composition will be described with reference to the graph of FIG. .
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 a density at a temperature t ₄ (hereinafter referred to as a complete decoloring temperature) that reaches a completely decolored state, and B is a temperature t ₃ (hereinafter referred to as a decoloring start temperature). C is a point indicating a density at a temperature t ₂ at which color development starts (hereinafter referred to as a color development start temperature), and D is a temperature t ₁ at which a complete color development state is reached (hereinafter referred to as a complete color development state). This is a point indicating a density at a color development temperature).
The discoloration temperature region is the temperature region between t ₁ and t ₄ , and both the colored state and the decolored state can coexist, and the temperature region between t ₂ and t _3, which is a region where the difference in color density is large, is substantial. Discoloration temperature range (two-phase holding temperature range).
The length of the line segment EF is a scale indicating the discoloration contrast, and the length of the line segment HG is a temperature width indicating the degree of hysteresis (hereinafter referred to as hysteresis width ΔH). It is easy to maintain each state before and after the color change.
In the reversible thermochromic composition, the complete color development temperature t ₁ is set to a temperature at which color development does not occur due to the environmental temperature in winter or the like of 0 ° C. or less.
The complete color development temperature t ₁ is preferably −40 to −5 ° C., more preferably −30 to −10 ° C.
Furthermore, complete decoloring temperature _{t 4,} the temperature is not decolorized by summer environment such as temperature, i.e. 50 ° C. or higher, preferably specific to a range of 60 to 100 [° C., the ΔH values 40 to 100 ° C., preferably from 50 to By specifying 100 ° C., it is possible to effectively function to maintain colors exhibited in a normal state (daily life temperature range).
Here, the difference between t ₃ and t ₄ , or the difference between t ₁ and t ₂ (Δt) is a scale indicating the sensitivity of discoloration.

Specific examples of the compounds (a), (b), and (c) of the reversible thermochromic composition are shown below.
As the component (a), that is, the electron donating color-forming organic compound, 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-diphenylaminofluorane,
3,6-dimethoxyfluorane,
3,6-di-n-butoxyfluorane,
2-methyl-6- (N-ethyl-Np-tolylamino) fluorane,
3-chloro-6-cyclohexylaminofluorane,
2-methyl-6-cyclohexylaminofluorane,
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) fluorane,
2- (3-methoxy-4-dodecoxystyryl) quinoline,
Spiro [5H- (1) benzopyrano (2,3-d) pyrimidine-5,1 '(3'H) isobenzofuran] -3'-one,
2- (diethylamino) -8- (diethylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) pyrimidine-5,1 ′ (3′H) isobenzofuran] -3-one,
2- (Di-n-butylamino) -8- (di-n-butylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) pyrimidine-5,1 '(3' H) Isobenzofuran] -3-one,
2- (Di-n-butylamino) -8- (diethylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) 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-g) pyrimidine-5,1 ' (3′H) isobenzofuran] -3-one,
3- (2-methoxy-4-dimethylaminophenyl) -3- (1-butyl-2-methylindol-3-yl) -4,5,6,7-tetrachlorophthalide,
3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4,5,6,7-tetrachlorophthalide,
3- (2-ethoxy-4-diethylaminophenyl) -3- (1-pentyl-2-methylindol-3-yl) -4,5,6,7-tetrachlorophthalide,
3 ′, 6′-bis [phenyl (2-methylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9 ′-[9H] xanthen] -3-one,
3 ′, 6′-bis [phenyl (3-methylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9 ′-[9H] xanthen] -3-one,
And 3 ', 6'-bis [phenyl (3-ethylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9'-[9H] xanthen] -3-one.
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 component (b), a group of compounds having active protons, a group of pseudo-acidic compounds (a group of compounds that are not acids but act as an acid in the composition and cause component (a) to develop color), electrons There is a group of compounds having pores.
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 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-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) Sulfonyl) n- heptane, there is 2,2-bis (4'-hydroxyphenyl) n- nonane.

（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８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。 As the reaction medium for controlling the color reaction of (a) and (b) and (b), a compound represented by the following general formula (1) is preferably used.

(In the formula, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom, m represents an integer of 1 to 3, and n represents an integer of 1 to 8).
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)] dies with ethanol It can be exemplified Le.

〔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.

The component ratios of the components (A), (B), and (C) depend on the concentration, the color change temperature, the color change form, and the type of each component. In general, the component ratio that provides the desired characteristics is ( (B) The component 1 is in the range of (b) the component 0.1-50, preferably 0.5-20, (c) the component 1-800, preferably 5-200. Part).
Each component may be a mixture of two or more, and an antioxidant, an ultraviolet absorber, an infrared absorber, a dissolution aid, etc. can be added as long as the function is not hindered.

The mixture of the components (a), (b), and (c) is preferably encapsulated in a microcapsule and used as a reversible thermochromic microcapsule pigment. Chemicals such as acidic substances, basic substances, and peroxides are preferable. Even if it comes into contact with other active substances or other solvent components, its function is not lowered, and heat stability can be maintained, and the reversible thermochromic composition has the same composition under various use conditions. This is because the same action and effect can be achieved.
The microcapsule pigment satisfies the practicality in the range of an average particle size of 1.0 to 20 μm, preferably 1.5 to 15 μm, more preferably 2 to 10 μm.
When the average value of the maximum outer diameter of the microcapsule pigment exceeds 20 μm, the dispersion stability is insufficient for use in inks and paints.
On the other hand, in a system having an average value of the maximum outer diameter of 1.0 μm or less, it is difficult to exhibit high density color development.
For the microcapsules, the range of inclusion / wall membrane = 7/1 to 1/1 (mass ratio) is effective, and when the ratio of inclusion is larger than the above range, the color density and sharpness during color development decrease. The inclusion / wall membrane = 6/1 to 1/1 (mass ratio) is preferable.
The microencapsulation includes conventionally known isocyanate-based interfacial polymerization methods, in-situ polymerization methods such as melamine-formalin, in-liquid curing coating methods, phase separation methods from aqueous solutions, phase separation methods from organic solvents, melting There are a dispersion cooling method, an air suspension coating method, a spray drying method, and the like, which are appropriately selected according to use. 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.

  Furthermore, 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). JP, 2003-253149, etc., and a heat-colorable reversible thermochromic composition, and a microcapsule pigment containing the same can also be used as a reversible thermochromic material ( (See FIG. 2).

In the present invention, the reversible thermochromic material is dispersed in a vehicle to prepare a liquid composition such as paint or printing ink, and printing such as screen printing, offset printing, gravure printing, coater, tampo printing, transfer, etc. A reversible thermochromic layer is formed on a support such as paper, synthetic paper, or plastic film by means such as means, brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, or dip coating. A reversible thermochromic display is obtained.
The thickness of the reversible thermochromic layer is preferably 3 to 100 μm, and if it is less than 3 μm, the color density is too low and the contrast before and after the color change is poor. On the other hand, when the thickness exceeds 100 μm, it becomes difficult for heat or cold from the printing apparatus to be uniformly transferred to the reversible thermochromic layer, and it becomes difficult to exhibit a sufficient color changing function.
The reversible thermochromic material or the liquid composition using the reversible thermochromic material is blended with a general dye or pigment (non-thermochromic), and exhibits a color change behavior from colored (1) to colored (2). It can also be presented.
In addition, an anchor coat layer for improving adhesion and a colored layer with non-color-changing ink for imparting design properties can be appropriately provided between the support and the reversible thermochromic layer as necessary.

The shape and size of the support are not particularly limited, but preferably have a planar shape, and may be a small one in the form of a card or a large one used for a display, such as a bulletin board, a guide plate, It can also be used for POP and the like.
The support is a recording body made of a magnetic material, an information recording card or an information recording tag provided with a recording body such as an IC chip that can record, rewrite and read information in a non-contact manner on the front, back and inner surfaces of the support. It may be.

Examples of the heating device for forming an image on the reversible thermochromic display include a thermal head, a heat roller, a hot stamp, an electric heater, laser light, hot water, steam, and the like, and in particular, precise recording via a computer. A thermal head capable of performing the above is suitable.
Moreover, a refrigerator, a freezer, an ice piece, a cool storage material, a Peltier element etc. are mentioned as a cooling-heat apparatus.

The reversible thermochromic display exhibits the following four different states depending on the color change of the reversible thermochromic material, and light fastness in each state is an important requirement.
The four states and light fastness are as follows. If a problem occurs in any state, the visibility is remarkably deteriorated when the display information is rewritten.
1. Maintaining color density when the reversible thermochromic material is exposed to light in a colored state.
2. Prevention of browning when the reversible thermochromic material is exposed to light in a colored state and then decolored.
3. Maintaining color density when the reversible thermochromic material is exposed to light in a decolored state and then colored.
4). Prevention of browning when the reversible thermochromic material is exposed to light in a decolored state.
By reducing the oxygen concentration in the encapsulating system, the light fastness improving effects 1 and 3 can be obtained, and by using the ultraviolet absorber described later, higher light fastness can be obtained.

As the low oxygen permeability inclusion body, an inclusion body made of a synthetic resin having at least a display surface having transparency is used.
The low oxygen permeability inclusion body has an oxygen permeability of 70 ml / m ² · day · atm or less, preferably 15 ml / m ² · day · atm or less, more preferably 5 ml / m ² · day · atm or less. Used.
As the material of the low oxygen permeability inclusion body, a film made of a synthetic resin such as polyester, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, nylon, polyacrylonitrile, cellulose (cellophane) or the like has low oxygen permeability. In particular, a material obtained by depositing a silicon oxide such as silica or an aluminum oxide such as alumina on a film surface made of the synthetic resin is preferably used.
Moreover, even if it is a resin such as polypropylene, polyethylene, polystyrene, etc. that does not have low oxygen permeability by itself, the above-described synthetic resin showing low oxygen permeability is coated, bonded, co-extruded, or thin film deposited. It is also possible to use a composite material that has been applied.
Furthermore, within the range that does not impair the display properties in the encapsulated body, an opaque film obtained by vacuum-depositing aluminum on the synthetic resin can be used together, or an opaque printing layer can be provided on the synthetic resin to improve the design.
In order to improve the sealing performance, a sealing body having various structures can be provided at the opening of the oxygen-low-permeable inclusion body, but it is preferable to provide a male-female occlusion type chuck (tape with chuck).
In addition, the low oxygen-permeable inclusion body can be provided with a pressure-sensitive adhesive layer on the back surface and can be attached to various objects.

The oxygen absorbing material is not particularly limited as long as it is a material that absorbs oxygen. Reduced iron, ascorbic acid, nylon / cobalt salt, conjugated double bond polymer, cyclohexene group-containing polymer Although an oxygen absorption composition such as a system can be used, a self-supporting reaction type oxygen absorption composition containing water is preferably used because it does not depend on the amount of water inside the inclusion body, and has a reducing property. Since an oxygen absorption composition is excellent in an oxygen absorption rate, it is used more suitably.
A package in which the oxygen-absorbing composition is enclosed, or a sheet coated or sandwiched between resin films can be used as the oxygen-absorbing material.
The oxygen absorbing material is different in absorption amount and oxygen amount depending on the type and size of the oxygen absorbing composition, and an absorbing material having an appropriate oxygen absorbing capacity with respect to the oxygen amount in the enclosure is selected and used. . In addition, the oxygen absorbing material not only absorbs oxygen in the inclusion body but also has a function of absorbing a small amount of oxygen that permeates the inside of the inclusion body and maintains light fastness for a long period of time. The thermochromic function can be maintained.
Commercially available oxygen absorbers include AGELESS (trade name) manufactured by Mitsubishi Gas Chemical Co., Ltd., Everfresh (trade name) manufactured by Torisho Sangyo Co., Ltd., and Sanso Cut (trade name) manufactured by Oe Chemical Industry Co., Ltd. ), Taisei Co., Ltd. Well Pack (trade name), Powder Tech Co., Ltd. Wonder Keep (trade name), and the like.
When using a self-supporting oxygen absorbing composition containing water as described above, water vapor is generated in the process of oxygen absorption and may evaporate in a sealed enclosure, thereby hindering visibility. It is also possible to use a material that is sealed together or has both oxygen absorption ability and drying function, such as Pharmakeep (trade name) manufactured by Mitsubishi Gas Chemical Co., Ltd.
Further, an oxygen detector capable of visually recognizing the oxygen concentration is enclosed together with the oxygen absorbing material.
The oxygen detector described above is an anthraquinone-based, indigo-based, thiazine-based, a dye that exhibits a color change by a reducing agent such as a sulfur dye, an alkaline substance such as an alkali metal or alkaline earth metal hydroxide or salt, a reducing saccharide, etc. A material composed of a reducing agent is used.
Examples of commercially available oxygen detectors include Ageless Eye (trade name) manufactured by Mitsubishi Gas Chemical Co., Ltd., Wonder Sensor (trade name) manufactured by Powder Tech Co., Ltd., and the like.
The oxygen detector may be an oxygen detector / oxygen absorber integrated with an oxygen absorber.

In the reversible thermochromic layer of the reversible thermochromic display body or in the low oxygen permeable inclusion body, an ultraviolet absorber can be contained in order to improve the light resistance during decoloring. Furthermore, by providing a layer containing an ultraviolet absorber on the reversible thermochromic layer of the reversible thermochromic display or on the surface of the low oxygen permeable inclusion, the light resistance during decoloring can be improved.
Examples of the ultraviolet absorber include 2,4-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxy. Benzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-octoxybenzophenone, bis- (2-methoxy-4-hydroxy-5-benzoylphenyl) -methane 2- [2'- Hydroxy-3'-5'-di-t-amylphenyl] -benzophenone, 2-hydroxy-4-dodecyloxy-benzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone 2-hydroxy-4-benzyloxyben Phenone, 2- [2'-hydroxy-3'-5'-di -t- amyl phenyl] - benzophenone ultraviolet absorbers such as benzophenone.
Phenyl salicylate, para-t-butylphenyl salicylate, para-octylphenyl salicylate, 2-4-di-t-butylphenyl-4-hydroxybenzoate, 1-hydroxybenzoate, 1-hydroxy-3-t-butyl-benzoate, 1 Salicylic acid ultraviolet absorbers such as hydroxy-3-t-octylbenzoate and resorcinol monobenzoate.
Cyanoacrylate UV absorption such as ethyl-2-cyano-3,3'-diphenyl acrylate, 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate, 2-ethylhexyl-2-cyano-3-phenylcinnarate Agent.
2- [5-t-butyl-2-hydroxyphenyl] -benzotriazole, 2- [5-methyl-2-hydroxyphenyl] -benzotriazole, 2- [2, hydroxy-3,5-bis (a, a -Dimethylbenzyl) phenyl] -2H benzotriazole, 2- [3,5-di-tert-butyl-2-hydroxyphenyl] -benzotriazole, 2- [3-tert-butyl-5-methyl-2-hydroxyphenyl ] -5-chlorobenzotriazole, 2- [3,5-di-t-butyl-2-hydroxyphenyl] -5-chlorobenzotriazole, 2- [3,5-di-t-amyl-2-hydroxyphenyl] ] -Benzotriazole, 2- [3-dodecyl-5-methyl-2-hydroxyphenyl] benzotriazole, 2- [3-t-butyl-5-propiyl] Octylate-2-hydroxyphenyl] -5-chlorobenzotriazole, 2- [2-hydroxyphenyl-3,5-di- (1,1'-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- [2- Hydroxy-5-t-octylphenyl] -2H-benzotriazole, 2- [3-t-butyl-5-octyloxycarbonylethyl-2-hydroxyphenyl] -benzotriazole, 2- [2-hydroxy-5-tetra Octylphenyl] -benzotriazole, 2- [2-hydroxy-4-octoxy-phenyl] -benzotriazole, 2- [2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimide Methyl) -5'-methylphenyl] -benzotriazole, 2- (2-hydroxy-5-t Butylphenyl) - benzotriazole ultraviolet absorbers such as benzotriazole.
Ethanediamide-N- (2-ethoxyphenyl) -N ′-(4-isododecylphenyl), 2,2,4,4-tetramethyl-20- (β-lauryl-oxycarbonyl) -ethyl-7-oxa- Examples include oxalic acid anilide ultraviolet absorbers such as 3,20-diazodispiro (5,1,11,2) heneic acid-21-one.

In the case where the reversible thermochromic material contained in the reversible thermochromic layer of the reversible thermochromic display is a material that is decolored by heating and develops color by cooling, reversible heat can be obtained by applying a cooling device that contains a cool liquid material in advance. An image is formed on the display body in which the color changing layer is colored by using a heating device equipped with a thermal head, and then enclosed in an oxygen low-permeability inclusion body together with an oxygen absorbing material for display.
In the case where the reversible thermochromic material contained in the reversible thermochromic layer of the reversible thermochromic display material is a material that develops color by heating and decolors by cooling, reversible heat can be obtained by applying a cooling device that contains a cool liquid material in advance. An image is formed on the display body from which the color-changing layer has been erased by using a heating device equipped with a thermal head, and then enclosed in an oxygen low-permeability inclusion body together with an oxygen absorber for display.
Thereafter, when changing the image formed on the display body, the oxygen low-permeability inclusion body is opened, the reversible thermochromic display body is taken out, and the reversible thermochromic layer is formed again by applying a cooling device containing the cooling liquid material. After decoloring and forming a new image using a heating device equipped with a thermal head, it is enclosed in an oxygen low-permeability inclusion body together with an oxygen absorbing material for practical use.
In the oxygen low-permeability inclusion body, a plurality of reversible thermochromic display bodies of different sizes are enclosed in the same direction, or the back surfaces of the plurality of reversible thermochromic display bodies are sealed together. However, it can also be configured such that the image is viewed from both sides.
Furthermore, an irreversible thermochromic display can be enclosed together with the reversible thermochromic display.
As the irreversible thermochromic display body, a display body in which an irreversible thermochromic composition that develops color by heating comprising a color former, a developer, a sensitizer, and other additives is coated on a support is used.
As the color former, the compounds exemplified as the component (a) of the reversible thermochromic composition can be used.
As the developer, an acidic compound having an active proton exemplified as the component (b) of the reversible thermochromic composition can be used.
The sensitizer is a heat-meltable material that contacts and develops a color former that is solid at room temperature and a developer under heating, and natural or synthetic waxes and higher fatty acids can be used.
The irreversible thermochromic composition may contain additives such as a binder resin that improves adhesion to the support and a stabilizer that stabilizes the image after color development.

Here, when the liquid body accommodated in the heating or cooling device is brought into contact with the display body to change the color of the reversible thermochromic layer, the display body is preferably provided with a protective layer having resistance to the liquid body.
As the protective layer, a known transparent resin is used, and a crosslinkable resin excellent in solvent resistance and scratch resistance is preferably used.
The crosslinkable resin is a resin having a reactive functional group in a resin molecule and capable of forming a three-dimensional structure by a reaction with a crosslinking agent or a crosslinking reaction such as self-polymerization or self-condensation. A protective resin layer can be formed.
Specifically, as the crosslinkable resin, an ultraviolet curable resin composed of a polymerization initiator and an acrylate ester resin, an isocyanate curing agent and a polyol resin, and a thermosetting resin composed of an amine curing agent and an epoxy resin. Can be mentioned.
The protective layer is preferably 0.2 to 3 times as thick as the reversible thermochromic layer. If the thickness is less than 0.2, it is difficult to sufficiently satisfy the resistance to the liquid material. It becomes difficult to develop a sufficient color changing function.

Furthermore, the resistance index according to the following resistance test method can be used as a reference for satisfying good resistance of the protective layer to the liquid.
The resistance test method is to prepare a reversible thermochromic display body in which a reversible thermochromic layer and a protective layer are sequentially provided on a white polyester resin support, cut into a 2 cm × 4 cm rectangle, and then before the resistance test. The brightness value (Ma) of the reversible thermochromic display is measured with a color difference meter (TC-3600, manufactured by Tokyo Denshoku Co., Ltd.).
Next, the reversible thermochromic display is adhered to the frictional part on the upper part of the friction tester (manufactured by Suga Test Instruments Co., Ltd., FR-2 type), and the target liquid with a load of 500 g (including the frictional element). Reciprocating friction is performed 100 times on a cotton cloth (gold width 3) impregnated with the body.
At this time, the cotton cloth is impregnated with 0.02 to 0.03 g / cm ² of a liquid material and tested. In the reciprocating friction, the friction element is reciprocated horizontally over a distance of 10 cm on the liquid-impregnated cloth at a speed of 30 reciprocations / minute.
The brightness value (Mb) of the reversible thermochromic display after the test is measured by the same method as before the test, and the resistance index (M) is calculated from the following formula (2).
M = (Ma / Mb) × 100 (2)
Ma: Lightness value of the reversible thermochromic display before the resistance test Mb: Lightness value of the reversible thermochromic display after the resistance test The lightness values represented by Mb and Ma are completely achromatic. Shows the brightness value of the Munsell color chart system in which black is 0 and complete white is 10, and the difference in brightness is equally spaced between them. The smaller the brightness value, the closer it is to black. The larger the is, the closer it is to white.
By this test, for example, when the protective layer is damaged, the reversible thermochromic layer is physically dropped and the white polyester resin of the support is visually recognized, so the lightness value (Mb) is high and relatively resistant. The index (M) is low.
Also, when the reversible thermochromic material in the reversible thermochromic layer fades due to the influence of the liquid, or when the protective layer itself is whitened by being attacked by the liquid, the lightness value Mb is similarly increased. The resistance index (M) is low.
On the contrary, if the surface damage or swelling due to the test is slight and the difference in brightness before and after the test is small, the resistance to the target liquid is excellent, and the resistance index (M) is a value close to 100. Become.
If the said tolerance index (M) is a value of 80-100, Preferably it is 90-100, it has practical tolerance.

The said protective layer can also provide the performance which contradicts as a multilayer structure of two or more layers.
For example, the uppermost layer of the protective layer is desirably an ultraviolet curable resin having excellent scratch resistance, but if an ultraviolet absorber is added to the layer to improve light resistance, curing by ultraviolet rays is inhibited. The structure which provides the layer containing is mentioned.
In the case where the protective layer has a multilayer structure of two or more layers, a transparent resin film can also be used as one of the protective layers.
Examples of the transparent resin film include polyolefin resins such as polypropylene, cellulose derivatives such as cellulose acetate, polyester resins such as polyethylene terephthalate, polyamide resins, vinyl alcohol resins such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers. The film which consists of polyester resin is used suitably from the point of the resin strength.
When the transparent resin film is used, the visibility of the image formed on the reversible thermochromic layer is not hindered, and high durability can be imparted by preventing penetration, swelling and whitening by the liquid.

In the case of using a cooling / discoloring device containing a cooling liquid, a medium suitable for the use environment is selected and used in consideration of the physical properties of the freezing point, vapor pressure, and surface tension.
The freezing point of the cold liquid material needs to be liquid at the complete coloring temperature t ₁ of the reversible thermochromic material, and the freezing point (G) and temperature t ₁ of the cold liquid material satisfy the following formula (1). More preferably, the image can be erased in a short time.
G <t ₁ -20 (1)
Moreover, it is preferable that the cold liquid material volatilizes rapidly at room temperature after erasing the image, and a liquid material having a higher vapor pressure than water is preferably used.
Furthermore, if the permeability of the cold liquid to the reversible thermochromic display is high, the protective layer and the reversible thermochromic layer are likely to be damaged. Preferably there is.
The following table shows typical cold liquids and their freezing points, vapor pressures, and surface tensions.

From the freezing point, vapor pressure, and surface tension of the liquids listed in the table, monohydric alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol satisfy both cooling and drying properties, and are preferred as the cold liquid of the present invention.
Moreover, the said cold / hot liquid body can also be used 1 type or in mixture of 2 or more types suitably, In that case, the liquid body which contains above-mentioned monohydric alcohol 70 mass% or more as a main component is suitable. .
Furthermore, the content of organic solvents in the range of 70 to 89% by mass of ethyl alcohol as a main component and the organic solvent poisoning prevention regulations (hereinafter referred to as organic rules) of the Industrial Safety and Health Act is 5%. The liquid material of the mixed component that is less than the above satisfies the practicality.
The organic law stipulates 54 types of organic solvents. When these organic solvents are used, it is obliged to prepare a working environment according to laws and regulations, and there are various restrictions on handling. On the other hand, ethyl alcohol is not classified into the 54 types of organic solvents, and even in the classified solvent types, if the content is 5% or less, the organic law is not stipulated.
Moreover, although the cold-heated liquid substance containing 90 mass% or more of ethyl alcohol can also be used, since the liquor tax law is applied when content becomes 90% or more, the liquid body of the said mixed component is suitable.
Specific examples of the liquid material of the mixed component include a liquid material comprising 86% by mass of ethyl alcohol, 4% by mass of methyl alcohol, and 10% by mass of n-propyl alcohol.
In the liquid containing 70% by mass or more of the monohydric alcohol, water can be added within a range that does not hinder the fluidity at low temperatures.
The following table shows the mixing ratio of ethyl alcohol and water and the liquid viscosity at low temperatures.
The ratio in a table | surface shows the mass% and a viscosity shows mPa * s.

Further, when the liquid material contained in the heating or cooling device is brought into contact with the display body to change the color of the reversible thermochromic layer, the dry state of the liquid material adhering to the display body or the adhesion of condensation is determined. A porous layer can also be provided.
The porous layer will be described.
The porous layer is a layer in which a low refractive index pigment is fixed in a dispersed state together with a binder resin, and is a layer having different transparency in a dry state and a liquid absorption state.
Examples of the low refractive index pigment include silicic acid and salts thereof, barite powder, barium sulfate, barium carbonate, calcium carbonate, gypsum, clay, talc, alumina white, magnesium carbonate, and the like. It is in the range of 1.8, and shows good transparency when water is absorbed.
Examples of the silicic acid salts include aluminum silicate, aluminum potassium silicate, sodium aluminum silicate, aluminum calcium silicate, potassium silicate, calcium silicate, calcium sodium silicate, sodium silicate, magnesium silicate, and magnesium potassium silicate.
Two or more of the low refractive index pigments can be used in combination.

The low refractive index pigment is dispersed in a vehicle containing a binder resin as a binder, applied to a support, and then the volatile matter is dried to form a porous layer.
Examples of the binder resin include urethane resin, nylon resin, vinyl acetate resin, acrylic ester resin, acrylic ester copolymer resin, acrylic polyol resin, vinyl chloride-vinyl acetate copolymer resin, maleic resin, polyester resin, styrene. Resin, styrene copolymer resin, polyethylene resin, polycarbonate resin, epoxy resin, styrene-butadiene copolymer resin, acrylonitrile-butadiene copolymer resin, methyl methacrylate-butadiene copolymer resin, butadiene resin, chloroprene resin, melamine resin, and the above Each resin emulsion, casein, starch, cellulose derivative, polyvinyl alcohol, urea resin, phenol resin and the like can be mentioned.
Since the porous layer can confirm the adhesion of moisture due to the liquid material or condensation, it can be visually sufficiently dried before sealing, and the liquid material and moisture can evaporate in the inclusion body to cloud the display surface, It is possible to prevent the thermal discoloration function from being impaired.

Examples of the present invention are shown below, but the present invention is not limited thereto.
The preparation of the reversible thermochromic microcapsule pigment encapsulating the reversible thermochromic composition will be described below. In addition, the part in a compounding example shows a mass part.

Preparation of microcapsule pigment a encapsulating a reversible thermochromic composition (i) 4.5 parts of 2- (2-chloroamino) -6-dibutylaminofluorane as component, 4,4'- as component (b) A reversible thermochromic composition comprising 8 parts of (2-ethylhexane-1,1-diyl) diphenol and 50 parts of 4-benzyloxyphenylethyl caprate as a component (c) is encapsulated in a microcapsule and reversibly thermochromic. Microcapsule pigment a was obtained.
The microcapsule pigment has a complete color development temperature t ₁ of −20 ° C., a complete color erasing temperature t ₄ of 64 ° C., and a hysteresis width (ΔH) of 65 ° C., and changes color from black to colorless according to temperature change.

Preparation of Microcapsule Pigment b Encapsulating Reversible Thermochromic Composition (a) 2- (Dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3] -G] 2.5 parts of pyrimidine-5,1 '(3'H) -isobenzofuran] -3-one, 4,4'-(2-ethylhexane-1,1-diyl) di as component (b) A reversible thermochromic composition comprising 8 parts of phenol and 50 parts of 4-benzyloxyphenylethyl caprate as component (c) was encapsulated in microcapsules to obtain reversible thermochromic microcapsule pigment b.
The microcapsule pigment has a complete color development temperature t ₁ of −18 ° C., a complete decoloration temperature t ₄ of 64 ° C., and a hysteresis width (ΔH) of 70 ° C., and changes color from pink to colorless according to temperature change.

Preparation of microcapsule pigment c encapsulating a reversible thermochromic composition (a) 3 parts 1,3-dimethyl-6-diethylaminofluorane as component (4) 4,4 '-(2-ethylhexane- A reversible thermochromic microcapsule pigment c is prepared by encapsulating a reversible thermochromic composition comprising 8 parts of 1,1-diyl) diphenol and 50 parts of 4-benzyloxyphenylethyl caprate as component (c). Obtained.
The microcapsule pigment has a complete color development temperature t ₁ of −20 ° C., a complete color erasing temperature t ₄ of 62 ° C. and a hysteresis width (ΔH) of 67 ° C., and changes its color from orange to colorless according to the temperature change.

Preparation of Microcapsule Pigment d Encapsulating Reversible Thermochromic Composition (a) 3- (4-Diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl)-as Component 1 part of 4-azaphthalide, 8 parts of 4,4 '-(2-ethylhexane-1,1-diyl) diphenol as component (b), and 50 parts of 4-benzyloxyphenylethyl caprate as component (c) The reversible thermochromic composition was encapsulated in microcapsules to obtain reversible thermochromic microcapsule pigment d.
The microcapsule pigment has a complete color development temperature t ₁ of −20 ° C., a complete decoloration temperature t ₄ of 65 ° C., and a hysteresis width (ΔH) of 70 ° C., and changes color from blue to colorless according to temperature change.

Preparation of microcapsule pigment e enclosing reversible thermochromic composition (a) 6 '-(dipentylamino) -2'-[(3- (trifluoromethyl) phenyl) amino] -spiro [isobenzofuran- 5 parts of 1 (3H), 9 '-(9H) xanthen] -3-one, 10 parts of 4,4'-(2-ethylhexane-1,1-diyl) diphenol as component (b), (c) A reversible thermochromic composition encapsulating 50 parts of 4-benzyloxyphenylethyl caprate as a component was encapsulated in microcapsules to obtain a reversible thermochromic microcapsule pigment e.
The microcapsule pigment has a complete color development temperature t ₁ of −20 ° C., a complete color erasing temperature t ₄ of 62 ° C. and a hysteresis width (ΔH) of 67 ° C., and changes its color from dark green to colorless according to the temperature change.

Preparation of Microcapsule Pigment f Encapsulating Reversible Thermochromic Composition (I) 9-Ethyl (3-methylbutyl) amino-spiro [12H-benzo (a) xanthene-12,1 ′ (3H) isobenzofuran] as component -3'-one 3 parts, (b) component 4,4 '-(2-ethylhexane-1,1-diyl) diphenol 8 (c) component 4-benzyloxyphenylethyl caprate 50 parts The reversible thermochromic composition comprising the above was encapsulated in microcapsules to obtain reversible thermochromic microcapsule pigment f.
The microcapsule pigment has a complete color development temperature t ₁ of −20 ° C., a complete decoloration temperature t ₄ of 62 ° C., and a hysteresis width (ΔH) of 67 ° C., and changes color from pink to colorless according to temperature change.

Preparation of Microcapsule Pigment g Encapsulating Reversible Thermochromic Composition (a) 3 ', 6'-bis [phenyl (3-methylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9' as component (a) -1.5 parts of [9H] xanthen] -3-one, 8 parts of 4,4 '-(2-ethylhexane-1,1-diyl) diphenol as component (b), capric acid 4 as component (c) -A reversible thermochromic composition comprising 50 parts of benzyloxyphenylethyl was encapsulated in microcapsules to obtain reversible thermochromic microcapsule pigment g.
The microcapsule pigment has a complete color development temperature t ₁ of −18 ° C., a complete decoloration temperature t ₄ of 62 ° C., and a hysteresis width (ΔH) of 65 ° C., and changes color from blue to colorless according to temperature change.

Preparation of microcapsule pigment h containing reversible thermochromic composition (a) 7- [2- (acetylamino) -4- (diethylamino) phenyl] -7- (2-methyl-1-propyl-1H as component (a) -Indol-3-yl) furo [3,4-b] pyridin-5 (7H) -one 1.5 parts, (4)-(2-ethylhexane-1,1-diyl) as component (b) A reversible thermochromic composition encapsulating 8 parts of diphenol and 50 parts of 4-benzyloxyphenylethyl caprate as component (c) was encapsulated in microcapsules to obtain reversible thermochromic microcapsule pigment h.
The microcapsule pigment has a complete color development temperature t ₁ of −18 ° C., a complete color erasing temperature t ₄ of 62 ° C. and a hysteresis width (ΔH) of 65 ° C., and the color changes from blue-green to colorless according to the temperature change.

Preparation of Microcapsule Pigment i Encapsulating Reversible Thermochromic Composition (a) 3 parts of 2- (2-chloroamino) -6-dibutylaminofluorane as component (4), 4,4 ′-(2 -A reversible thermochromic composition comprising 6 parts of methylpropane-1,1-diyl) diphenol, 30 parts of stearyl alcohol as component (c) and 20 parts of stearyl laurate in a microcapsule. Capsule pigment i was obtained.
The microcapsule pigment has a complete color development temperature t ₁ of 37 ° C. and a complete decolorization temperature t ₄ of 51 ° C., and changes color from black to colorless according to temperature change.

Preparation of Microcapsule Pigment j Encapsulating Reversible Thermochromic Composition (I) 3- (4-Diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl)-as Component 4-Azaphthalide 1 part, (b) component 4,4 '-(2-methylpropane-1,1-diyl) diphenol 5 part, (c) component cetyl alcohol 5 parts, myristyl alcohol 20 parts, myristic acid The reversible thermochromic composition comprising 25 parts of decyl was encapsulated in microcapsules to obtain reversible thermochromic microcapsule pigment j.
The microcapsule pigment has a complete color development temperature t ₁ of 11 ° C. and a complete decolorization temperature t ₄ of 22 ° C., and changes color from blue to colorless according to temperature change.

Preparation of reversible thermochromic display body On synthetic paper as a support, 40 parts of the reversible thermochromic microcapsule pigment a 52 parts ethylene-vinyl acetate copolymer resin emulsion, 1 part thickener, 3 parts leveling agent, water 4 Using a reversible thermochromic ink obtained by dispersing in a vehicle consisting of parts, a reversible thermochromic display is formed by printing a rectangular solid pattern by screen printing to form a reversible thermochromic layer (test sample a). Got.
By the same method as described above, reversible thermochromic microcapsule pigments b to f were used to obtain reversible thermochromic displays (test samples b to f).

Light irradiation test Each of the test samples is cooled or heated to prepare a sample in which the reversible thermochromic layer is in a colored state and a sample in which the reversible thermochromic layer is in a decolored state. For 60 hours using a xenon chamber [manufactured by Suga Test Instruments Co., Ltd., XT75L].
Measuring instrument for reflection density value in the state where the reversible thermochromic layer of each test sample is colored before light irradiation and the reflection density value in the state where the reversible thermochromic layer of each test sample is colored after light irradiation (manufactured by Gretag Macbeth) , Spectro Eye), and the color density retention was calculated by the following formula.
Color density retention rate (%) = (reflection density after test / reflection density of untested sample) × 100
The following table shows the color tone of the reversible thermochromic display, and the test results when each form (the reversible thermochromic layer of the display is unencapsulated and encapsulated in a colored state and a decolored state, respectively) is irradiated with light.

The form of the test sample in the table is described below.
Form 1: A test sample is irradiated with light as it is.
Form 2: Oxygen low-permeability inclusion body (produced by Nippon Co., Ltd., Lamigrip VP (trade name), a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film are bonded together. Oxygen permeability of 3.4 to 3.7 ml / m ² · day · atm bag] and oxygen absorber [Mitsubishi Gas Chemical Co., Ltd., AGELESS (trade name)] enclosed, light one day later Irradiate.
Form 3: A polyester resin film containing an ultraviolet absorber was laminated on the test sample, and an oxygen low-permeability inclusion body [manufactured by Japan Manufacturing Co., Ltd., Lamigrip VP (trade name), and silica deposited] Oxygen absorber [Mitsubishi Gas Chemical Co., Ltd.] in a bag having an oxygen permeability of 3.4 to 3.7 ml / m ² · day · atm bonded with an axially stretched polyester resin film and an unstretched polypropylene resin film Made with AGELESS (trade name)] and irradiated with light one day later.
Form 4: Oxygen low permeability inclusion body [Co., Ltd. production Japan Co., Ltd., Lamigrip OP (trade name), biaxially stretched polypropylene resin film and unstretched polypropylene resin film bonded together] Is enclosed in an oxygen absorbent material (manufactured by Mitsubishi Gas Chemical Co., Ltd., Ageless (trade name)) in a bag of 1100 to 1200 ml / m ² · day · atm], and irradiated with light one day later.
Form 5: The test sample is placed in an inclusion body (a bag made of a single layer film made of a polyethylene resin having a oxygen permeability of 3000 to 5000 ml / m ² · day · atm, manufactured by Nippon Production Co., Ltd., Unipack (trade name)). Enclosed together with an oxygen absorber [Mitsubishi Gas Chemical Co., Ltd., Ageless (trade name)] and irradiated with light one day later.
The symbols for evaluating the color density retention rate in the table will be described below.
A: The density retention is in the range of 81 to 100%.
B: Density retention is in the range of 61-80%.
C: Concentration retention is in the range of 41-60%.
D: Density retention is in the range of 21-40%.
E: The concentration retention is in the range of 0 to 20%.

From the above test results, the test sample was enclosed with an oxygen absorber in an oxygen low-permeability inclusion body having an oxygen permeability of 1200 ml / m ² · day · atm or less compared to the system in which the test sample was directly irradiated with light. The light-irradiated system has greatly improved the light fastness of the display.

The test samples a, c, d, and e are cooled or heated to prepare a sample in which the reversible thermochromic layer is colored and a sample in which the reversible thermochromic layer is in a decolored state. Then, light was irradiated for 60 hours using a xenon chamber (manufactured by Suga Test Instruments Co., Ltd., XT75L).
Measuring device (Gretag Macbeth) reflection density value in the state where the reversible thermochromic layer of each test sample before light irradiation is decolored and reflection density value in the state where the reversible thermochromic layer of each test sample after light irradiation is decolored The residual color increase rate was calculated by the following formula.
Residual color increase rate (%) = (reflection density after test / reflection density of untested sample) × 100
The following table shows the color tone of the reversible thermochromic display, and the test results when each form (the reversible thermochromic layer of the display is unencapsulated and encapsulated in a colored state and a decolored state, respectively) is irradiated with light.

Form 1: A test sample is irradiated with light as it is.
Form 2: A polyester resin film containing an ultraviolet absorber is laminated on the test sample, and an oxygen low-permeability inclusion body [manufactured by Japan Manufacturing Co., Ltd., Lamigrip VP (trade name), silica is deposited on the test sample. Oxygen absorber [Mitsubishi Gas Chemical Co., Ltd.] in a bag having an oxygen permeability of 3.4 to 3.7 ml / m ² · day · atm bonded with an axially stretched polyester resin film and an unstretched polypropylene resin film Made with AGELESS (trade name)] and irradiated with light one day later.
The symbols for evaluating the concentration increase rate in the table will be described below.
A: The residual color increase rate is 100% or less.
B: The residual color increase rate is in the range of 101 to 150%.
C: The residual color increase rate is in the range of 151 to 200%.
D: The residual color increase rate is in the range of 201 to 300%.
E: The residual color increase rate is 301% or more.

  From the above test results, compared to the system that directly irradiates the test sample with light, the system in which the test sample is encapsulated in an oxygen low-permeability inclusion body with an oxygen absorbing material and an ultraviolet absorbing layer on the upper layer is irradiated with light. Even when exposed to light, there is no residual color (browning) of the reversible thermochromic layer, and the light fastness of the display is greatly improved.

Production of reversible thermochromic display body In the vehicle comprising the reversible thermochromic microcapsule pigment e34 parts, the reversible thermochromic microcapsule pigment f6 parts, 50 parts of urethane resin emulsion, 2 parts of antifoaming agent and 1 part of thickener. A reversible thermochromic ink that disperses in black and changes color from black to colorless is obtained.
Next, an anchor coat layer (thickness 1 μm) containing a transparent urethane resin is provided on a white polyester resin film (54 mm × 86 mm, thickness 188 μm) as a support, and the reversible thermochromic ink is used as the upper layer. A reversible thermochromic layer (thickness 20 μm) is provided, and an ultraviolet absorbing layer (thickness 15 μm) made of an acrylic copolymer resin having a benzotriazole skeleton, an amine-modified epoxy acrylate oligomer, a polyester acrylate oligomer, and an acrylate monomer. A protective layer (thickness: 20 μm) made of an ultraviolet curable resin was sequentially provided to obtain a reversible thermochromic display.

The alphabet (A, B, C) is printed on the reversible thermochromic display using a printer equipped with a thermal head, and the xenon chamber [Suga test] Was irradiated with light for 20 hours using XT75L].
Subsequently, the reversible thermochromic display was cooled to completely color the reversible thermochromic layer, and visually observed for fading and browning.
Furthermore, the reversible thermochromic display was heated to completely erase the reversible thermochromic layer, and the presence or absence of browning was visually observed.
The following table shows the test results when the display body was irradiated with light in each form (the reversible thermochromic layer was unencapsulated and encapsulated in a colored state and a decolored state, respectively).

The form of the test sample in the table is described below.
Form 1: A test sample is irradiated with light as it is.
Form 2: Oxygen low-permeability inclusion body (produced by Nippon Co., Ltd., Lamigrip VP (trade name), a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film are bonded together. Oxygen permeability of 3.4 to 3.7 ml / m ² · day · atm bag] and oxygen absorber [Mitsubishi Gas Chemical Co., Ltd., AGELESS (trade name)] enclosed, light one day later Irradiate.
Aspect 3: Oxygen low permeability inclusion body [manufactured by Japan Co., Ltd., Lamigrip KP (trade name), biaxially stretched polypropylene resin film coated with vinylidene chloride resin coating and unstretched polypropylene resin film Oxygen permeability of 9.4 to 13.0 ml / m ² · day · atm bag] with an oxygen absorbent material [Mitsubishi Gas Chemical Co., Ltd., Ageless (trade name)] enclosed in Light is irradiated after a day.
Form 4: Oxygen low-permeability inclusion body [produced by Japan Co., Ltd., lamizip LZ (trade name), nylon resin film and unstretched polypropylene resin film were bonded to each other, and the test sample was an oxygen low permeability inclusion body of 59.0. In a bag of ˜65.0 ml / m ² · day · atm] together with an oxygen absorbing material [manufactured by Mitsubishi Gas Chemical Co., Ltd., Ageless (trade name)], and irradiated with light one day later.
Form 5: Oxygen low-permeability inclusion body (produced by Nippon Co., Ltd., Lamigrip OP (trade name), biaxially stretched polypropylene resin film and unstretched polypropylene resin film) Is enclosed in an oxygen absorbent material (manufactured by Mitsubishi Gas Chemical Co., Ltd., Ageless (trade name)) in a bag of 1100 to 1200 ml / m ² · day · atm], and irradiated with light one day later.
The explanation about the symbol of evaluation of fading and browning in the state in which the reversible thermochromic layer is completely colored and in the state in which it is completely decolored is as follows.
(Double-circle): A difference is not seen compared with the sample before light irradiation.
○: There is almost no difference compared to the sample before light irradiation.
Δ: Slight fading and browning are observed as compared with the sample before light irradiation.
▲: Fading and browning are observed compared to the sample before light irradiation.
X: Significant fading and browning are observed as compared with the sample before light irradiation.

From the above test results, a system in which a test sample is enclosed in an oxygen low-permeability inclusion body with an oxygen permeability of 65 ml / m ² · day · atm or less is a light irradiation system and an oxygen low-permeability enclosure with a high oxygen permeability. Compared to the system in which the test sample is enclosed in the body, the reversible thermochromic layer after light irradiation is fully colored or completely decolored, and there is no fading or browning and has a sufficient reversible thermochromic function. ing.

Reference example 1
Preparation of reversible thermochromic ink Reversible thermochromic property in which 40 parts of the microcapsule pigment a are dispersed in a vehicle comprising 50 parts of a urethane resin emulsion, 2 parts of an antifoaming agent and 1 part of a thickener to change the color from black to colorless. An ink was obtained.

Production of reversible thermochromic display body As a support, a reversible thermochromic layer (thickness 20 μm) is provided on a white polyester resin film (54 mm × 86 mm, thickness 188 μm) using the reversible thermochromic ink, and further thereon A protective layer (thickness 20 μm) made of UV-curable resin of amine-modified epoxy acrylate oligomer, polyester acrylate oligomer and acrylate monomer was provided to obtain a reversible thermochromic display (POP sheet).

Preparation of low oxygen permeability inclusion body A composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 3.4 to 3.7 ml / m ^2. A day-atm bag-like oxygen-low-permeable inclusion body was produced.
A male-female occlusion chuck is provided in the opening of the oxygen-low-permeable inclusion body.

Preparation of encapsulated reversible thermochromic display body The product name and price sold in the supermarket are printed on the display body using a printer equipped with a thermal head, and then iron powder and water having reducibility are put into the system. The self-reactive oxygen absorbing material contained in is enclosed in an oxygen low-permeability enclosure, and an encapsulated reversible thermochromic display is obtained.
The encapsulated reversible thermochromic display has a clear white print information visually recognized on a black background, and the above-described reversible thermochromic display body can be used in both a low temperature environment in winter (0 ° C.) and a high temperature environment in summer (38 ° C.). The printing information can be retained, and the initial thermochromic function can be exhibited permanently without causing a decrease in color density at the portion where the reversible thermochromic layer is colored even when irradiated with light.

Reference example 2
Preparation of reversible thermochromic ink Reversible thermochromic property in which 40 parts of the microcapsule pigment a are dispersed in a vehicle comprising 50 parts of a urethane resin emulsion, 2 parts of an antifoaming agent and 1 part of a thickener to change the color from black to colorless. An ink was obtained.

Production of reversible thermochromic display body An anchor coat layer (thickness 1 μm) containing a transparent urethane resin is provided on the surface of a white polyester resin film (54 mm × 86 mm, thickness 188 μm) as a support, and the reversible thermochromic color is formed thereon. A reversible thermochromic layer (thickness 20 μm) is formed using an ink, and an ultraviolet absorbing layer (thickness 15 μm) made of an acrylic copolymer resin having a urethane resin and a benzotriazole skeleton on the upper layer, an amine-modified epoxy acrylate oligomer, polyester acrylate A protective layer (thickness 20 μm) made of an ultraviolet curable resin of oligomer and acrylate monomer was sequentially provided to obtain a reversible thermochromic display (card).

Preparation of inclusion body with low oxygen permeability A composite film composed of a biaxially stretched polypropylene resin film coated with a vinylidene chloride resin coat and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 9.4 to 13.0 ml / A bag-like oxygen low-permeability inclusion body of m ² · day · atm was produced.
A male-female occlusion chuck is provided in the opening of the oxygen-low-permeable inclusion body.

Creation of enclosed reversible thermochromic display body The entrance / exit information of the conference room is printed using a printer equipped with a thermal head on the display body, and then self-comprising containing iron powder and water having reducibility in the system An encapsulated reversible thermochromic display (conference room management card) was obtained by enclosing it in a low oxygen permeable enclosure together with a reactive oxygen absorber.
In the encapsulated reversible thermochromic display, white entry / exit information is clearly visually recognized on a black background, both in a low temperature environment in winter (0 ° C.) and a high temperature environment in summer (38 ° C.). The print information could be retained, and the initial thermochromic function could be developed permanently without causing a decrease in color density at the portion where the reversible thermochromic layer developed even when irradiated with light. .

Reference example 3
Preparation of reversible thermochromic ink Reversible thermochromic color which disperses 25 parts of the microcapsule pigment b in a vehicle comprising 65 parts of urethane resin emulsion, 2 parts of antifoaming agent and 1 part of thickening agent to change the color from pink to colorless. Ink was obtained.

Production of reversible thermochromic display body As a support, a reversible thermochromic layer (thickness 20 μm) is provided on the surface of a white polyester resin film (45 mm × 45 mm, thickness 25 μm) using the reversible thermochromic ink, and further thereon. UV protective layer (thickness 15 μm) made of urethane resin, acrylic copolymer resin with benzotriazole skeleton, 15 μm thick protective layer (thickness 20 μm) made of amine-modified epoxy acrylate oligomer, polyester acrylate oligomer, acrylate monomer Thus, a reversible thermochromic display (label) was obtained.

Preparation of low oxygen permeability inclusion body A composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 3.4 to 3.7 ml / m ^2. A day-atm bag-like oxygen-low-permeable inclusion body was produced.
In addition, an adhesive is applied to the back surface of the oxygen-low-permeable inclusion body to provide an adhesive layer.

Preparation of encapsulated reversible thermochromic display body Using a printer equipped with a thermal head on the display body, information on clinical departments and doctors in charge is printed, and then iron powder and water having reducibility are included in the system. A self-reactive oxygen absorber and an oxygen low-permeability encapsulant are encapsulated and then encapsulated on the surface of an IC card (thickness 750 μm) made of a white polyester resin encapsulating an IC chip. A discoloration display (diagnosis ticket) was obtained.
The encapsulated reversible thermochromic display can clearly see white printed information on a pink background and can be used in both a low temperature environment in winter (0 ° C.) and a high temperature environment in summer (38 ° C.). The print information could be retained, and the initial thermochromic function could be developed permanently without causing a decrease in color density at the portion where the reversible thermochromic layer developed even when irradiated with light. .

Reference example 4
Preparation of reversible thermochromic ink The reversible thermochromic ink is reversible in which the microcapsule pigment b10 parts and c30 parts are dispersed in a vehicle comprising 50 parts of urethane resin emulsion, 2 parts of antifoaming agent, and 1 part of thickener to change the color from red to colorless. A thermochromic ink was obtained.

Production of reversible thermochromic display body An anchor coat layer (thickness 1 μm) containing a transparent urethane resin is provided on the surface of a white polyester resin film (85 mm × 200 mm, thickness 188 μm) as a support, and the reversible thermochromic color is formed thereon. A reversible thermochromic layer (thickness 20 μm) is formed using an ink, and an ultraviolet absorbing layer (thickness 15 μm) made of an acrylic copolymer resin having a urethane resin and a benzotriazole skeleton on the upper layer, an amine-modified epoxy acrylate oligomer, polyester acrylate A protective layer (thickness 20 μm) made of an ultraviolet curable resin of oligomer and acrylate monomer was sequentially provided to obtain a reversible thermochromic display (sheet).

Production of low oxygen permeability inclusion body A bag-like oxygen low permeability inclusion body having an oxygen permeability of 59 to 65 ml / m ² · day · atm by laminating a composite film made of a nylon resin film and a polyethylene resin film Produced.
A male-female occlusion chuck is provided in the opening of the oxygen-low-permeable inclusion body.

Production of encapsulated reversible thermochromic display body The distribution information in the factory line is printed on the display body using a printer equipped with a thermal head, and then self-comprising containing iron powder having reducibility and water in the system. An encapsulated reversible thermochromic display (information display sheet) was obtained by enclosing it in a low oxygen permeable enclosure together with a reactive oxygen absorber.
The enclosed reversible thermochromic display has a red background with clearly visible white factory line distribution information, both in a low temperature environment in winter (0 ° C) and a high temperature environment in summer (38 ° C). The print information could be retained, and the initial thermochromic function could be developed permanently without causing a decrease in color density at the portion where the reversible thermochromic layer developed even when irradiated with light. .

Example 1
Preparation of reversible thermochromic ink Reversible thermochromic property in which 20 parts of the microcapsule pigment c are dispersed in a vehicle comprising 70 parts of an acrylic resin emulsion, 2 parts of an antifoaming agent, and 1 part of a thickener to change the color from orange to colorless. An ink was obtained.

Production of reversible thermochromic display body An anchor coat layer (thickness 1 μm) containing a transparent urethane resin is provided on the surface of a white polyester resin film (210 mm × 297 mm, thickness 188 μm) as a support, and the reversible thermochromic color is formed on the upper layer. A reversible thermochromic layer (thickness: 18 μm) is formed using water-based ink, and an ultraviolet absorbing layer (thickness: 10 μm) made of an acrylic copolymer resin having a urethane resin and a benzotriazole skeleton on the upper layer, an amine-modified epoxy acrylate oligomer, polyester acrylate A protective layer (thickness 10 μm) made of an ultraviolet curable resin of an oligomer and an acrylate monomer was sequentially provided to obtain a reversible thermochromic display (POP sheet).

Preparation of low oxygen permeability inclusion body Oxygen permeability of 3.4 to 3.7 ml / m ² · day bonded with a composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film -A polyester resin film containing an ultraviolet absorber was provided on the surface of an atm bag-like body to produce an oxygen low-permeability inclusion body.
A male-female occlusion chuck is provided in the opening of the oxygen-low-permeable inclusion body.

Preparation of encapsulated reversible thermochromic display body The product name and price sold in the supermarket are printed on the display body using a printer equipped with a thermal head, and then iron powder and water having reducibility are put into the system. The self-reactive oxygen absorbing material and the oxygen detector contained in are encapsulated in an oxygen low-permeability encapsulant to obtain an encapsulated reversible thermochromic display.
In the encapsulated reversible thermochromic display, the oxygen concentration in the encapsulated body could be easily confirmed by the encapsulated oxygen detector.
In the encapsulated reversible thermochromic display, white print information is clearly visually recognized on an orange background, and the encapsulated reversible thermochromic display body can be used in both a low temperature environment in winter (0 ° C.) and a high temperature environment in summer (38 ° C.). The printing information can be retained, and the initial thermochromic function can be exhibited permanently without causing a decrease in color density at the portion where the reversible thermochromic layer is colored even when irradiated with light.

Example 2
Preparation of reversible thermochromic ink 30 parts of the microcapsule pigment d and 5 parts of non-thermochromic fluorescent pink pigment are dispersed in a vehicle comprising 50 parts of urethane resin emulsion, 2 parts of antifoaming agent and 1 part of thickener. A reversible thermochromic ink that changes from purple to pink was obtained.

Production of reversible thermochromic display body An anchor coat layer (thickness 1 μm) containing a transparent urethane resin is provided on the surface of a white polyester resin film (85 mm × 200 mm, thickness 125 μm) as a support, and the reversible thermochromic color is formed thereon. A reversible thermochromic layer (thickness 20 μm) is formed using water-based ink, and an ultraviolet absorbing layer (thickness 10 μm) made of an acrylic copolymer resin having a urethane resin and a benzotriazole skeleton on the upper layer, an amine-modified epoxy acrylate oligomer, polyester acrylate A protective layer (thickness 10 μm) made of an ultraviolet curable resin of an oligomer and an acrylate monomer was sequentially provided to obtain a sheet.
Then, the said sheet | seat and the white polyester sheet (thickness 125 micrometers) provided with the IC chip were bonded, and the reversible thermochromic display body (IC sheet) was obtained.

Preparation of low oxygen permeability inclusion body A composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 3.4 to 3.7 ml / m ^2. A day-atm bag-like oxygen-low-permeable inclusion body was produced.
An adhesive layer is provided on the back surface of the low oxygen permeability enclosure by applying an adhesive.

Production of encapsulated reversible thermochromic display body The reversible thermochromic display body is printed with distribution information in a factory line using a printer equipped with a thermal head, and then iron powder and water having reducibility are printed. A self-reactive oxygen absorbing material and an oxygen detector contained in the system were placed in an oxygen low-permeability enclosure and enclosed to obtain an encapsulated reversible thermochromic display (information display IC sheet).
In the encapsulated reversible thermochromic display, the oxygen concentration in the encapsulated body could be easily confirmed by the encapsulated oxygen detector.
The encapsulated reversible thermochromic display body clearly shows the distribution information of a pink factory line on a purple background, and is either under a low temperature environment in winter (0 ° C.) or under a high temperature environment in summer (38 ° C.). In addition, the print information can be retained, and the initial thermochromic function can be expressed permanently without causing a decrease in color density of the portion where the reversible thermochromic layer is colored even when irradiated with light. did it.

Example 3
Preparation of reversible thermochromic ink The reversible thermochromic ink is reversible in which the microcapsule pigment e34 parts and f6 parts are dispersed in a vehicle comprising 50 parts of urethane resin emulsion, 2 parts of antifoaming agent and 1 part of thickener to change the color from black to colorless. A thermochromic ink was obtained.

Production of reversible thermochromic display body As a support, an anchor coat layer (thickness 1 μm) containing a transparent urethane resin is provided on the surface of a white polyester resin film (96 mm × 36.5 mm, thickness 188 μm), and the reversible layer is formed thereon. A transparent silver metal in which a reversible thermochromic layer (thickness 20 μm) is provided using a thermochromic ink, and further, an urethane copolymer, an acrylic copolymer resin having a benzotriazole skeleton, and a mica surface coated with titanium oxide. A metallic luster protective layer A (thickness 15 μm) containing a luster pigment, an amine-modified epoxy acrylate oligomer, a polyester acrylate oligomer, and a protective layer B (thickness 20 μm) made of an acrylate monomer UV-curable resin are sequentially provided to change the color from silver to colorless. A reversible thermochromic display (sheet) was obtained.

Preparation of low oxygen permeability inclusion body A composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 3.4 to 3.7 ml / m ^2. A day-atm bag-like oxygen-low-permeable inclusion body was produced.
A male-female occlusion chuck is provided in the opening of the oxygen-low-permeable inclusion body.

Creation of encapsulated reversible thermochromic display body The reversible thermochromic display body is printed with the name and price of a product sold at a supermarket using a printer equipped with a thermal head, and then with iron powder having reducing properties, A self-reactive oxygen absorber containing water in the system, an oxygen detector, and a desiccant were placed in an oxygen low-permeability enclosure and enclosed to obtain an encapsulated reversible thermochromic display (shelf label).
In the encapsulated reversible thermochromic display, the oxygen concentration in the encapsulated body could be easily confirmed by the encapsulated oxygen detector, and the evaporation of water vapor generated from the oxygen absorbing material by the desiccant could be prevented.
In the encapsulated reversible thermochromic display, white print information is clearly visually recognized on a silver background, and the above-described reversible thermochromic display is effective in both a low temperature environment in winter (0 ° C.) and a high temperature environment in summer (38 ° C.). The printing information can be retained, and the initial thermochromic function can be exhibited permanently without causing a decrease in color density at the portion where the reversible thermochromic layer is colored even when irradiated with light.

Example 4
Preparation of reversible thermochromic ink Reversible thermochromic that disperses 25 parts of the microcapsule pigment in a vehicle composed of 65 parts of urethane resin emulsion, 2 parts of antifoaming agent and 1 part of thickening agent and changes color from pink to colorless. Ink was obtained.

Preparation of discolorable ink Wet method 15 parts of silicic acid, 30 parts of urethane resin emulsion, 50 parts of water, 0.5 part of antifoaming agent, 3 parts of thickener, 1 part of ethylene glycol, 3 parts of isocyanate-based crosslinking agent are uniformly mixed Thus, a color-changing ink whose transparency is changed by liquid absorption was obtained.

Production of reversible color-changing display body A reversible thermochromic layer (40 mm × 40 mm, thickness) using the reversible thermochromic ink on the surface of a white polyester resin plate (54 mm × 86 mm, thickness 750 μm) enclosing an IC chip as a support. 20 μm), and an ultraviolet absorbing layer (thickness 15 μm) made of an acrylic copolymer resin having a benzotriazole skeleton, and an ultraviolet curable resin of an amine-modified epoxy acrylate oligomer, a polyester acrylate oligomer, and an acrylate monomer. A protective layer (thickness 20 μm) was sequentially provided.
Next, a square (10 mm × 10 mm) colored layer is provided using a non-color-changing red ink at a location where each layer on the support is not formed, and a porous layer is provided using the color-changing ink as an upper layer. A reversible color change display was obtained.

Preparation of low oxygen permeability inclusion body A composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 3.4 to 3.7 ml / m ^2. A day-atm bag-like oxygen-low-permeable inclusion body was produced.
A male-female occlusion chuck is provided in the opening of the oxygen-low-permeable inclusion body.

Production of encapsulated reversible thermochromic display The video lending status is printed on the reversible thermochromic display using a printer equipped with a thermal head. The self-reactive oxygen absorbing material and the oxygen detector contained in are encapsulated in an oxygen low-permeability encapsulant to obtain an encapsulated reversible thermochromic display (IC card for video rental).
In the encapsulated reversible thermochromic display, the oxygen concentration in the encapsulated body could be easily confirmed by the encapsulated oxygen detector.
The encapsulated reversible thermochromic display can clearly see white printed information on a pink background and can be used in both a low temperature environment in winter (0 ° C.) and a high temperature environment in summer (38 ° C.). The print information could be retained, and the initial thermochromic function could be developed permanently without causing a decrease in color density at the portion where the reversible thermochromic layer developed even when irradiated with light. .

Reference Example 5
Preparation of reversible thermochromic ink In a vehicle comprising 14 parts of the microcapsule pigment, 6 parts of h, 0.6 part of a non-thermochromic yellow pigment, 70 parts of an acrylic resin emulsion, 2 parts of an antifoaming agent, and 1 part of a thickener. A reversible thermochromic ink A that disperses in green and changes color from green to yellow was obtained.
20 parts of the microcapsule pigment g was dispersed in a vehicle comprising 70 parts of an acrylic resin emulsion, 2 parts of an antifoaming agent, and 1 part of a thickening agent to obtain a reversible thermochromic ink B that changes color from blue to colorless.

Production of reversible thermochromic display body As a support, an anchor coat layer (1 μm thickness) containing a transparent urethane resin is provided on the surface of a white polyester resin film (128 mm × 182 mm, thickness 188 μm), and the reversible thermochromic color is formed on the upper layer. Of reversible thermochromic layer (thickness 20 μm) using water-soluble ink A, UV absorbing layer (thickness 15 μm) made of acrylic resin having benzotriazole skeleton, urethane resin, amine-modified epoxy acrylate oligomer, polyester acrylate oligomer, acrylate monomer A reversible thermochromic display A was obtained by sequentially providing a protective layer (thickness 20 μm) made of an ultraviolet curable resin.
Next, using the reversible thermochromic ink B, a reversible thermochromic display B was obtained in the same manner as described above.

Preparation of low oxygen permeability inclusion body A composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 3.4 to 3.7 ml / m ^2. A day-atm bag-like oxygen-low-permeable inclusion body was produced.
A male-female occlusion chuck is provided in the opening of the oxygen-low-permeable inclusion body.

Preparation of encapsulated reversible thermochromic display body Each of the display bodies A and B is printed with guide information of the exhibition hall using a printer equipped with a thermal head, and then iron powder and water having reducibility are put into the system. And a self-reactive oxygen absorbing material included in the above, and enclosed in a low oxygen permeable enclosure so that the back surfaces (non-information display surfaces) of the display bodies A and B are back to back. (Double-sided guidance display board) was obtained.
The enclosed reversible thermochromic display has a yellow background with a green background on one side and a white background with a blue background on the other side. I was able to confirm.
In addition, the print information can be retained both in a low temperature environment in winter (0 ° C.) and in a high temperature environment in summer (38 ° C.), and a reversible thermochromic layer develops color even when irradiated with light. The initial thermochromic function was able to be expressed permanently without causing a decrease in the color density of the portion.

Example 5
Preparation of reversible thermochromic ink 40 parts of the above microcapsule pigment is dispersed in a vehicle consisting of 52 parts of an ethylene-vinyl acetate copolymer resin emulsion, 1 part of a thickener, 3 parts of a leveling agent, and 4 parts of water, and is black to colorless. A reversible thermochromic ink that changes color was obtained.

Production of reversible thermochromic display body On the surface of synthetic paper (50 mm × 50 mm, thickness 200 μm) as a support, a character of “danger” is printed by using a non-color-changing red ink, and a colored image is provided on the upper layer. A circular (30 mm diameter) solid pattern was printed using reversible thermochromic ink, and then a transparent polyester resin film containing an ultraviolet absorber was laminated on the entire surface to obtain a reversible thermochromic display.

Preparation of low oxygen permeability inclusion body A composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 3.4 to 3.7 ml / m ^2. A day-atm bag-like oxygen-low-permeable inclusion body was produced.
An adhesive layer is provided on the back surface of the low oxygen permeability enclosure by applying an adhesive.

Preparation of encapsulated reversible thermochromic display body The display body is enclosed in an oxygen low-permeability inclusion body together with a self-reactive oxygen absorber containing reductive iron powder and water and an oxygen detector. It was made into a sealed reversible thermochromic display, and affixed to the pipe for practical use as a high temperature danger label.
In the encapsulated reversible thermochromic display, the oxygen concentration in the encapsulated body could be easily confirmed by the encapsulated oxygen detector.
In the encapsulated reversible thermochromic display, a black solid pattern is visually recognized when water of 40 ° C. or less flows in the pipe, but warm water exceeding 51 ° C. or high-temperature steam flows in the pipe. The reversible thermochromic layer disappeared, and the red “danger” character was visually recognized.
The aspect could be repeated.
Further, the encapsulated reversible thermochromic display body does not cause a decrease in the color density of the portion where the reversible thermochromic layer is colored even when repeatedly exposed to light, and further browns where the reversible thermochromic layer is decolored. The initial thermochromic function could be expressed permanently.

Example 6
Preparation of reversible thermochromic ink Reversible thermochromic property in which 40 parts of the microcapsule pigment a are dispersed in a vehicle comprising 50 parts of a urethane resin emulsion, 2 parts of an antifoaming agent and 1 part of a thickener to change the color from black to colorless. An ink was obtained.

Production of reversible thermochromic display body An anchor coat layer (thickness 1 μm) containing a transparent urethane resin is provided on the surface of a white polyester resin film (54 mm × 86 mm, thickness 188 μm) as a support, and the reversible thermochromic color is formed thereon. A reversible thermochromic layer (thickness 20 μm) is formed using an ink, and an ultraviolet absorbing layer (thickness 15 μm) made of an acrylic copolymer resin having a urethane resin and a benzotriazole skeleton on the upper layer, an amine-modified epoxy acrylate oligomer, polyester acrylate A protective layer (thickness 20 μm) made of an ultraviolet curable resin of oligomer and acrylate monomer was sequentially provided to obtain a reversible thermochromic display (card).

Preparation of irreversible thermochromic display material Synthesis on a fine paper as a support with 3-dibutylamino-6-methyl-7anilinofluorane and 4,4 '-(propane-2,2-diyl) diphenol A thermochromic composition comprising a wax was applied to obtain an irreversible thermochromic display that changes from colorless to black by heating.

Preparation of low oxygen permeability inclusion body A composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 3.4 to 3.7 ml / m ^2. A day-atm bag-like oxygen-low-permeable inclusion body was produced.
A male-female occlusion chuck is provided in the opening of the oxygen-low-permeable inclusion body.

Creation of an encapsulated reversible thermochromic display body Using a printer equipped with a thermal head for the reversible thermochromic display body, information on entrance / exit of a conference room, and the irreversible thermochromic display body for a meeting within a specific period. Each room use restriction information is printed, and then enclosed in a low oxygen permeable enclosure together with a self-reactive oxygen absorber containing oxygen powder and water, oxygen detector, and desiccant in the system. Thus, an encapsulated thermochromic display (meeting room management card) was obtained.
In the encapsulated thermochromic display, the oxygen concentration in the encapsulated body could be easily confirmed by the encapsulated oxygen detector, and the evaporation of water vapor generated from the oxygen absorbing material by the desiccant could be prevented.
In the reversible thermochromic display body in the encapsulated thermochromic display body, white entrance / exit information is clearly visible on a black background, under a low temperature environment in winter (0 ° C.) and a high temperature environment in summer. The printing information can be retained at any of (38 ° C.), and the initial thermal discoloration is permanent without causing a decrease in color density at the portion where the reversible thermochromic layer is colored even when irradiated with light. The function could be expressed.
Similarly, also in the irreversible thermochromic display, the black conference room use restriction information is clearly visually recognized on a white background, and even if it is irradiated with light, it does not cause a decrease in color density, and is permanent. The printing information was visible.

Example 7
Preparation of reversible thermochromic ink 40 parts of the microcapsule pigment j are dispersed in a vehicle consisting of 52 parts of an ethylene-vinyl acetate copolymer resin emulsion, 1 part of a thickener, 3 parts of a leveling agent, and 4 parts of water, and from blue to colorless A reversible thermochromic ink that changes color was obtained.

Production of reversible thermochromic display body On the surface of synthetic paper (50 mm x 50 mm, thickness 200 µm) as a support, the reversible thermochromic ink is used to print the letters "refrigerated" to provide a reversible thermochromic layer. Further, a transparent polyester resin film containing an ultraviolet absorber was laminated on the entire surface to obtain a reversible thermochromic display.

Preparation of low oxygen permeability inclusion body A composite film composed of a biaxially stretched polyester resin film deposited with silica and an unstretched polypropylene resin film is bonded to have an oxygen permeability of 3.4 to 3.7 ml / m ^2. A day-atm bag-like oxygen-low-permeable inclusion body was produced.
An adhesive layer is provided on the back surface of the low oxygen permeability enclosure by applying an adhesive.

Preparation of encapsulated reversible thermochromic display body The display body is enclosed in an oxygen low-permeability inclusion body together with a self-reactive oxygen absorber containing reductive iron powder and water and an oxygen detector. It was made into a sealed reversible thermochromic display and was put on practical use as a label for a refrigerator by sticking it in the vicinity of a transparent glass door whose internal state can be visually recognized from the outside in the refrigerator.
In the encapsulated reversible thermochromic display, the oxygen concentration in the encapsulated body could be easily confirmed by the encapsulated oxygen detector.
In the enclosed reversible thermochromic display, when the inside of the refrigerator is at a set temperature of 10 ° C. or lower, a blue “refrigerated” character is visually recognized. It is visible that the layer is decolored and is in a non-refrigerated state.
The aspect could be repeated.
Further, the encapsulated reversible thermochromic display body does not cause a decrease in the color density of the portion where the reversible thermochromic layer is colored even when repeatedly exposed to light, and further browns where the reversible thermochromic layer is decolored. The initial thermochromic function could be expressed permanently.

Comparative Example 1
The oxygen absorbing material was removed from the enclosure of Example 10 and attached to a pipe for practical use.
The encapsulated reversible thermochromic display initially exhibited a predetermined thermochromic function, but oxygen remains inside the encapsulant, so that the color density decreases when repeatedly exposed to light in a colored state. Even if the color disappeared, the browning was so severe that it was difficult to see the word “danger”.
Moreover, even if it was repeatedly exposed to light in a decolored state, the color density similarly decreased and browning occurred, so that practicality was not satisfied.

Comparative Example 2
An inclusion body was prepared in the same manner as in Example 12 except that the low oxygen permeability inclusion body of Example 12 was replaced with a bag made of a polyethylene resin single layer film having an oxygen permeability of 3000 to 5000 ml / m ² · day · atm. Then, it was put into the refrigerator and put into practical use.
The encapsulated reversible thermochromic display did not show a decrease in color density even when the reversible thermochromic layer was repeatedly exposed to light in a colored state, but it was encapsulated in a resin film having a high oxygen permeability. When the discolored layer was repeatedly exposed to light in a decolored state, the color density was remarkably lowered due to the influence of oxygen, and it was difficult to visually recognize the characters “during refrigeration”, which did not satisfy practicality.

t ₁ Complete color development temperature of a reversible thermochromic composition having a color memory property of ₁ heat decoloring type t ₂ Color development start temperature of a reversible thermochromic composition having a color memory property of ₂ heat decoloring type t ₃ Heat decoloring type Decoloration start temperature of reversible thermochromic composition having a color memory property of t ₄ Complete decolorization temperature of reversible thermochromic composition having a color memory property of ₄ heating decolorization type T ₁ Reversible thermochromic property of heating color developing type Complete decolorization temperature of composition T ₂ Decolorization start temperature of reversible thermochromic composition of heat-developing type T ₃ Decolorization start temperature of reversible thermochromic composition of _3- colored heat development type T ₄ Reversible thermochromic property of reversible thermochromic composition Complete coloring temperature of composition ΔH Hysteresis width 1 Encapsulated reversible thermochromic display 2 Reversible thermochromic display 21 Support 22 Reversible thermochromic layer 3 Oxygen absorber 4 Oxygen low permeability inclusion

Claims (11)

  On the support, at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color reaction of (a) and (b) above. A reversible thermochromic display body provided with a reversible thermochromic layer comprising a reversible thermochromic material, an oxygen absorber, and an oxygen detector capable of visually recognizing the oxygen concentration, oxygen having at least a display surface having transparency An encapsulated reversible thermochromic display encapsulated in a low-permeability encapsulant. The reversible thermochromic material comprises (a) an electron donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color reaction of (a) and (b). Is a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising: a large hysteresis characteristic with respect to a color density-temperature curve and exhibiting tautomerism between the first hue and the second hue. In the process of increasing the temperature in the first hue, when the temperature reaches t ₃ , the first hue starts to change color and completely becomes the second hue in a temperature range higher than the temperature t ₃ and higher than the temperature t ₄ . In the process of decreasing the temperature in the two-hue state, when the temperature t ₂ lower than the temperature t ₃ is reached, the second hue starts to change color and is completely in the temperature range below the temperature t ₁ lower than the temperature t ₂ . becomes 1 color, the temperature _{t 2} and the temperature t Shows the hysteresis characteristic in which the first color or the second color is held in a temperature range between the temperature t ₁ is the temperature of 0 ℃ or less, the temperature t ₄ of claim 1 wherein the temperature above 50 ° C. Enclosed reversible thermochromic display.   The encapsulated reversible thermochromic display according to claim 2, wherein the color density-temperature curve changes color with a hysteresis width (ΔH) of 40 ° C to 100 ° C. 4. The encapsulated reversible thermochromic display according to claim 1, wherein the oxygen-low-permeability inclusion body has an oxygen permeability of 70 ml / m ² · day · atm or less.   The encapsulated reversible thermochromic display according to any one of claims 1 to 4, wherein the oxygen absorbing material contains iron powder having reducibility.   The encapsulated reversible thermochromic display according to any one of claims 1 to 5, comprising an ultraviolet absorber in the reversible thermochromic layer of the reversible thermochromic display or in an oxygen low-permeability encapsulant. body.   The encapsulated reversible thermochromic change according to any one of claims 1 to 6, wherein a layer containing an ultraviolet absorber is provided on the reversible thermochromic layer of the reversible thermochromic display or on the surface of the low oxygen permeable inclusion. Sex indicator.   The encapsulated reversible thermochromic display body according to any one of claims 1 to 7, wherein a male-female occlusion chuck is provided in an opening of the oxygen-low-permeable enclosure.   The encapsulated reversible thermochromic display body according to any one of claims 1 to 8, wherein a plurality of reversible thermochromic display bodies are encapsulated in the low oxygen permeable enclosure.   The encapsulated reversible thermochromic display according to any one of claims 1 to 8, wherein an irreversible thermochromic display is encapsulated in the low oxygen permeable encapsulant.   The encapsulated reversible thermochromic display according to claim 1, wherein the oxygen detection agent is an oxygen detection and oxygen absorption material integrated with an oxygen absorption material.

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