JP2003192906A - Lightfast, thermally color-changing resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightfast, thermally color-changing composition obtained by fixing a thermally color-changing pigment onto a resin in a state of dispersion so that the light fastness of a thermally color-changing resin layer formed by printing, coating or similar treatment of the composition can be remarkably improved. <P>SOLUTION: This lightfast, thermally color-changing composition is obtained by fixing a thermally color-changing pigment with an average particle size of 0.5-30 μm in a state of dispersion, onto a resin having an oxygen gas barrier property selected from the group consisting of polyvinyl alcohol, a copolymer having ≥50% of an polyvinyl alcohol component, a polycarboxylic acid, a copolymer having ≥50% of a polycarboxylic acid and an ammonium salt or monovalent metal salt thereof, a copolymer having ≥50% of an acrylonitrile component, a monosaccharide and a polysaccharide. The resin having an oxygen gas barrier is formed as a continuous layer to cover the outer surface of the thermally color-changing pigment. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a light-resistant thermochromic resin composition. More specifically, it relates to a light-resistant thermochromic resin composition in which light resistance is remarkably improved in the form of a printed or coated layer or a molded body.

[0002]

2. Description of the Related Art Heretofore, some attempts have been disclosed to improve the light fastness of thermochromic materials. For example, Japanese Patent Publication No. 18543/1992 discloses an attempt to laminate a synthetic resin layer containing an ultraviolet absorber, an antioxidant and the like on a thermochromic layer. Also, as another attempt, an attempt is made to suppress the arrival at the lower thermochromic layer by providing a light reflecting layer or a light absorbing layer on the thermochromic layer to absorb or reflect ultraviolet rays or visible light. There is. Yet another attempt is to apply a colored filter.

[0003]

In the above-mentioned proposal, in the system in which the thermochromic material is an electron-donating reaction between an electron-donating color-forming organic compound and an electron-accepting compound, the above-mentioned ultraviolet absorber is used. It is difficult to completely prevent the photo-deterioration of the electron-donating color-forming organic compound only by the UV-cutting means. Further, in the system in which the light reflection layer is provided, the layer becomes whitish in order to prevent desired photodegradation, and it is difficult to sufficiently visualize the color change of the underlying thermochromic layer. on the other hand,
In systems where a light absorbing layer is provided, the layer may be dark or dark in color, obscuring the visual perception of color changes in the underlying thermochromic layer. Further, in a system in which a colored filter, for example, a yellow colored layer is arranged, when the thermochromic layer is blue, the electron-donating color-developing organic compound absorbs yellow light and reflects blue light. It is visible green due to the effect of the colored layer. Then, when the thermochromic layer changes to colorless, the electron-donating color-developing organic compound reflects all visible light, so that only the yellow light reflected from the yellow colored layer is visualized to be yellow and green. ← → It exhibits a reversible color change of yellow. Thus, even if the reversible color change from colored (1) to colored (2) is visualized, the reversible color change of colored ← → colorless cannot be visualized. The present inventor has found that the presence of oxygen is greatly involved in the process of photodegradation in a thermochromic material that develops and erases colors by an electron donating and accepting reaction between an electron-donating organic compound such as a leuco dye and an electron-accepting compound. In an oxygen-free atmosphere, it is less likely to deteriorate even when irradiated with light, and if oxygen can be eliminated, light resistance (especially the direct sunlight of the sun) can be significantly improved, and photodegradation is caused by oxygen molecules excited by ultraviolet rays. Based on this finding, the present inventors have completed the present invention by demonstrating that oxygen cutting is more efficient and more effective than ultraviolet cutting.

[0004]

According to the present invention, a thermochromic pigment having an average particle diameter of 0.5 to 30 μm is fixed in a dispersed state in an oxygen gas barrier resin to form a thermochromic resin layer. In addition, the light-resistant thermochromic resin composition is characterized in that the oxygen gas barrier resin in the thermochromic resin layer is a continuous layer that covers the outer surface of the thermochromic pigment. Furthermore, the thermochromic resin layer is a printing or coating layer formed on the surface of the support, and the thermochromic resin layer is a resin molding itself formed by blending thermochromic pigments integrally. The oxygen gas barrier resin is a polyvinyl alcohol, a copolymer containing 50% or more of a polyvinyl alcohol component, a polycarboxylic acid, a copolymer containing 50% or more of a polycarboxylic acid, and an ammonium salt or monovalent thereof. 50% of metal salts and acrylonitrile components of
The thermochromic pigment selected from the copolymers, monosaccharides, and polysaccharides contained above includes (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) both of the above. A thermochromic pigment in the form of microcapsules containing a thermochromic composition containing at least three components of an organic compound medium that reversibly causes the above-mentioned color reaction, an oxygen gas barrier resin / thermochromic pigment = 0.3 to 5.0 / 1.0
(Weight ratio), oxygen gas barrier resin / thermochromic pigment = 0.3 to 100 / 1.0 (weight ratio), and the like.

The thermochromic pigment is a coloring material that utilizes an electron-donating reaction between an electron-donating color-forming organic compound such as a leuco dye and an electron-accepting compound, and more specifically,
A thermochromic composition comprising (a) an electron-donating color-developing compound, (b) an electron-accepting compound, and (c) an organic compound medium that reversibly causes a color reaction between the two. A pigment in the form of microcapsules having an average particle diameter of 0.5 to 30 μm, which is encapsulated in, is effective. Examples of the (a) electron-donating color-developing organic compound include conventionally known diphenylmethanephthalides, fluoranes, diphenylmethaneazaphthalides, indolylphthalides, phenylindolylphthalides, and phenylindolylaza. Examples thereof include phthalides, styrinoquinolines, pyridine compounds and the like. (B) Examples of the electron-accepting compound include a compound group having an active proton, a pseudo-acidic compound group [a compound group which is not an acid but acts as an acid in the composition to develop an electron-donating compound], an electron cavity There is a group of compounds having pores. As an example of the compound having an active proton, as the compound having a phenolic hydroxyl group, there are monophenols to polyphenols, and as a substituent thereof, an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group,
Examples thereof include those having a carboxy group and its ester or amide group, a halogen group and the like, and bis type and tris type phenols and the like, phenol-aldehyde condensation resins and the like.
Further, it may be a metal salt of the compound having a phenolic hydroxyl group. (C) Organic compounds that reversibly cause the color reaction between the two include alcohols, esters, ketones,
Examples of conventional reaction media include ethers and acid amides. Further specific examples of the thermochromic material include Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, and Japanese Patent Publication No. 1-29 proposed by the present applicant.
Those described in Japanese Patent No. 398, etc. can be used. The above-mentioned proposal discolors before and after a predetermined temperature (discoloration point) as a boundary, exhibits a decolored state in a temperature range above the discoloration point, and exhibits a coloring state in a temperature range below the discoloration point, and is in a normal temperature range of the above two states. Then there can only be one particular state. That is, the other state is maintained while the heat or cold heat required to develop that state is applied, but returns to the state exhibited at room temperature when the heat or cold heat is no longer applied, the hysteresis _A heat-decolorable thermochromic composition having a relatively small width (ΔH _A = 1 to 7 ° C.) can be mentioned, and ΔH _A is 3
System below ℃ [3 ℃ shown in Japanese Patent Publication No. 1-29398]
The following ΔT value - is a fatty acid ester indicating the (melting point cloud point) to (c) applied as component], shows the heat decolorizing of sharply sensitive to high sensitivity to temperature changes, [Delta] H _A is 4 7 ° C
In the case of a system of a certain degree, after the discoloration, the original appearance is slowly restored, and the discoloration visual effect can be enhanced. Further, Japanese Patent Publication No. 4-17154, Japanese Patent Application Laid-Open No. 7-179777, Japanese Patent Application Laid-Open No. 7-33997, and Japanese Patent Application Laid-Open No. 8-3995 proposed by the present applicant.
36 shows a large hysteresis characteristic (ΔH _B = 8 to 50 ° C.), that is, the shape of the curve plotting the change of the coloring density due to the temperature change is such that the temperature is lower than the color change temperature range. Contrary to the case where the temperature is raised and when the temperature is lowered from the higher temperature side than the discoloration temperature range, the color changes following a greatly different path, and the color is developed in the low temperature range of t ₁ or lower, or in the high temperature range of t ₄ or higher. Is in a specific temperature range [temperature range between t _{2 and} t ₃ (substantially two-phase holding temperature range)]
It is possible to apply a color memory retention type thermochromic composition capable of alternatingly retaining memory. The low temperature side discoloration point in the above can be set to any temperature selected from the range of -30 ° C to 25 ° C, and the high temperature side discoloration point can be set to any temperature selected from the range of 27 ° C to 60 ° C. In an arbitrary temperature range between the low-temperature side discoloration point and the high-temperature side discoloration point, the respective discolored states below the low-temperature side discoloration point or above the high-temperature side discoloration point can be alternately stored in memory. The substantially two-phase holding temperature range generally includes a normal temperature range (for example, 15 to 35 ° C.), but is not limited to the temperature range. In addition, the present applicant's proposal that a heat-coloring type thermochromic composition develops color by heating from a decolored state (JP-A-11-1296).
23, JP-A-11-5973).
(B) As an electron-accepting compound, a system to which a specific alkoxyphenol compound having a linear or side chain alkyl group having 3 to 18 carbon atoms is applied, or a system to which a specific hydroxybenzoic acid ester is applied (Japanese Patent Laid-Open No. 2001-2001 10573
No. 2), a system to which gallic acid ester and the like are applied (Japanese Patent Publication No. 51
-44706).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As a specific embodiment of the light-resistant thermochromic resin composition of the present invention, a predetermined amount of thermochromic pigment is dispersed in a vehicle containing an oxygen gas barrier resin to prepare an ink or paint. None, heat obtained by forming thermochromic resin layer on the surface of support by conventional general-purpose printing or coating means, or directly blending thermochromic pigment in moldable resin and integrally molding The form of the discolorable resin molding can be mentioned.

In the system of the thermochromic resin layer formed by printing or coating, oxygen gas barrier resin / thermochromic pigment = 0.3 to 5.0 / 1.0 (weight ratio), preferably , Oxygen gas barrier resin / thermochromic pigment = 0.8 to 4.0
/1.0 (weight ratio) is effective. When the weight ratio of the oxygen gas barrier resin is less than 0.3, it is difficult to form a continuous layer effective for light fastness. On the other hand, when it exceeds 5.0, the thermochromic pigment is too small and vivid thermochromic property is exhibited. Not shown.
The thermochromic resin layer formed by printing or coating is generally 1 to 400 μm, preferably 4 to 200 μm.
m, and more preferably, a thickness of about 10 to 150 μm is practical.

In the thermochromic resin molding system,
Oxygen gas barrier resin / thermochromic pigment = 0.3-10
0 / 1.0 (weight ratio), preferably oxygen gas barrier resin / thermochromic pigment = 0.8 to 60/1 (weight ratio)
However, it has a clear color density, is effective in terms of visual effects due to thermal discoloration, forms a continuous layer of an oxygen gas barrier resin, and satisfies the strength of the molded body itself. In particular,
The thermochromic pigment may be melt-blended integrally with a thermoplastic resin to form various shaped bodies, film-like or sheet-like ones.

Examples of the oxygen gas barrier resin include polyvinyl alcohol, a copolymer containing 50% or more of a polyvinyl alcohol component, a polycarboxylic acid, a copolymer containing 50% or more of a polycarboxylic acid, and ammonium salts thereof. Alternatively, a resin selected from a monovalent metal salt, a copolymer containing 50% or more of an acrylonitrile component, a monosaccharide, and a polysaccharide can be mentioned. The polyvinyl alcohol and the copolymer containing 50% or more of the polyvinyl alcohol component include partially saponified polyvinyl alcohol (saponification degree: 88%), water-resistant polyvinyl alcohol (complete saponification type, water resistance imparted by hydrogen bond), completely saponified polyvinyl. Examples include a system containing an alcohol-based resin, a partially saponified product of vinyl acetate resin of 50% or more, and a resin containing 50% or more of a vinyl alcohol component in a copolymer of an ethylene component and a vinyl alcohol component.
As the curing means for the carbonyl group-containing polyvinyl alcohol, the water resistance can be improved by utilizing the reactivity of the carbonyl group and crosslinking by using epoxy, amines, hydrazines, oxazolines and the like. . Examples of the polycarboxylic acid include acrylic acid, methylmethacrylic acid, maleic acid, itaconic acid and the like, or a copolymer containing 50% of a carboxylic acid component, specifically, polyacrylic acid, acrylic acid-acrylic. Acid ester copolymer, polymethylmethacrylic acid, methylmethacrylic acid-acrylic acid ester copolymer, ethylene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, polyitaconic acid, acrylic acid-maleic acid Examples thereof include acid copolymers. These polycarboxylic acids may be in a free acid state or may be an ammonium salt or a monovalent metal salt. Examples of the copolymer containing 50% or more of the acrylonitrile component include acrylonitrile-acrylic acid-acrylic acid ester copolymer and acrylonitrile-acrylic acid ester-butadiene copolymer. Examples of monosaccharides include glucose and its isomers, and polysaccharides include sucrose, dextrins, solubilized starch, various plant-derived gum components such as sodium alginate, carboxymethylcellulose, and modified by microorganisms such as pullulan. Other polysaccharides can be exemplified.

The above-mentioned oxygen gas barrier resin is most effective when it occupies 100% of the applied resin, but it is effective even at an occupancy rate of about 50% by weight, A thermochromic resin layer formed by printing or coating with a binder resin for general-purpose printing or coating, or a blend of general-purpose molding resins and integrally molded to form molded articles of various forms. It may be.

Further, the oxygen permeability of both sides of the thermochromic resin layer is 1200 ml / (m ² · d · MPa) or less, preferably 800 ml / (m ² · d · MPa) or less, and more preferably. , 600 ml / (m ² · d · MP
a) The following base materials, for example, substantially oxygen impermeable base materials such as glass, metal foil and metal vapor-deposited film, specific resin coatings, etc. are formed, and the lightfastness of the thermochromic resin layer is further improved. You can improve your sex. As the specific resin film, polyester resin (including alkyd resin), polyamide resin, sodium alginate, polysaccharides such as pullulan, polyvinyl alcohol, ethylene-polyvinyl alcohol (EVOH), hard vinyl chloride resin, vinylidene chloride resin, acrylonitrile resin Examples thereof include coating films of acrylonitrile-vinyl chloride copolymer resin, vinylidene fluoride resin, ethylene-maleic acid copolymer resin, vinyl methyl ether-maleic acid copolymer resin, films, and the like.

As a concrete means, a resin film formed by bonding a resin film having a small oxygen transmission coefficient, coating a resin having a small oxygen transmission coefficient, spraying, or printing means on at least the surface of the thermochromic resin layer is effective. A system in which the thermochromic resin layer is closely arranged on both sides is most effective. The surface layer may function as a protective layer for the thermochromic resin layer, and the backside of the thermochromic layer may function as a support.

Further, in the system of the thermochromic resin layer formed by printing or coating, by providing a base layer having a titanium oxide pigment fixed to a binder resin in a dispersed state on the surface of the support, the influence of oxygen gas is provided. Can be further eliminated.

Further, conventionally used general-purpose light resistance improving means, for example, ultraviolet absorbers, antioxidants, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers, visible light absorbers, infrared rays. A light stabilizer selected from an absorber may be used in combination to further improve the light fastness.

[0015]

EXAMPLES In the following examples, light fastness was evaluated by the following evaluation methods.

[1] Evaluation Method of Color Density and Light Resistance Test (1) Measurement of Color Density The color density is CR-241 manufactured by Minolta Camera Co., Ltd.
The Y value was defined as the color density, and the residual density ratio was calculated by the following formula. Residual rate (%) = [(color density of test sample-color density after deterioration) / (color density of untested sample-color density after deterioration)]
× 100 (2) Light resistance test The light resistance test was performed by using a fade meter (manufactured by Suga Test Instruments Co., Ltd., long life carbon arc applied) and outdoor exposure (manufactured by Suga Test Instruments Co., Ltd., direct exposure to an outdoor exposure table). Irradiate:
11-December for 2 months). [2] Preparation of light-resistant thermochromic resin composition (1) Production example of thermochromic pigment Crystal violet lactone 1.0 part by weight, 1, 1
5.0 parts by weight of bis (4-hydroxyphenyl) decane,
50.0 parts by weight of stearyl alcohol and 10.0 parts by weight of an epoxy resin were uniformly dissolved and emulsified in 100 parts by weight of an 8% gelatin aqueous solution so as to have a thickness of 8 to 10 μm. Then, a 10% diethylenetriamine aqueous solution was added dropwise at 70 ° C., the temperature was raised to 90 ° C., the mixture was stirred for 5 hours, and then isolated by centrifugation to obtain a microcapsule thermochromic pigment (solid content: 60% by weight, 60% by weight). 120 parts by weight were obtained (colorless above 60 ° C. and reversibly exhibiting blue below 60 ° C.).

Example 1 30 parts by weight of the thermochromic pigment obtained in the above Production Example, acrylonitrile emulsion [oxygen gas barrier resin, acrylonitrile 70% -methyl acrylate 20% -acrylic acid 10% composition ratio. Emulsion polymerization liquid, solid content 3
0.0% by weight] 60 parts by weight, antifoaming agent 2 parts by weight, thickener 8
A thermochromic ink consisting of parts by weight was obtained [oxygen gas barrier resin / thermochromic pigment = 1.0 / 1.0 (solid content weight ratio)]. 100 g of the thermochromic ink was printed on a polyester film by 100 mesh screen printing.
Solid printing was performed so as to be / m ² and drying was performed to form a light-resistant thermochromic resin layer.

Comparative Example 1 The acrylonitrile emulsion of Example 1 was replaced with an ethylene-vinyl acetate emulsion to obtain a thermochromic ink in the same manner, and then solid printing was similarly carried out on a polyester film to produce a thermochromic pigment. A resin layer was obtained.

Lightfastness Test Results The printed materials of Example 1 and Comparative Example 1 were subjected to a comparison test according to the evaluation method of the lightfastness test described above. As a result, the thermochromic resin layer of Comparative Example 1 was tested for 1 hour by a fade meter tester. While the thermochromic resin layer of Example 1 was deteriorated by the irradiation of No. 3, the residual concentration ratio was 75% even after irradiation for 10 hours.

Example 2 A thermochromic ink comprising 35 parts by weight of a thermochromic pigment and 65 parts by weight of an aqueous solution of 10% polyvinyl alcohol (oxygen gas barrier resin) was prepared according to the preparation method of Example 1 [oxygen]. Gas barrier resin / thermochromic pigment = 0.3
1 / 1.0 (weight ratio of solid content) 30 g of the thermochromic ink on a polyester film by gravure printing
Solid printing was performed so as to be / m ² and drying was performed to form a light-resistant thermochromic resin layer. The thermochromic resin layer had a residual density of 7 after irradiation with a fade meter tester for 20 hours.
It was 5%. Moreover, the thermochromic resin layer of Comparative Example 1 deteriorated one day after irradiation by the exposure test by direct light (sunlight), but the thermochromic resin layer of Example 2 was exposed to exposure for one month. The residual concentration was 60%.

Example 3 30 parts by weight of a thermochromic pigment, 30 parts by weight of a polyacrylic acid oligomer (oxygen gas barrier resin), 38 parts by weight of water, and 2 parts by weight of an antifoaming agent were uniformly stirred and dispersed while heating. A thermochromic ink was obtained [oxygen gas barrier resin / thermochromic pigment = 1.67 / 1.0 (solid content weight ratio)]. When light resistance was confirmed by solid printing on a polyester film according to Example 1, the thermochromic resin layer had a residual density of 75% even after irradiation with a fade meter tester for 100 hours. Further, when the same light resistance test as described above was carried out using a thermochromic ink containing 28% ammonia water in place of the above water and containing an oxygen gas barrier resin made into a polyacrylic acid ammonium salt, The same light resistance performance was exhibited.

Example 4 30 parts by weight of a thermochromic pigment, 20 parts by weight of a yellow dextrin (oxygen gas barrier resin), 48 parts by weight of water, and 2 parts by weight of an antifoaming agent were uniformly stirred and dispersed to obtain a thermochromic property. An ink was obtained [oxygen gas barrier resin / thermochromic pigment = 1.1
1 / 1.0 (solid content weight ratio)]. When solid printing was carried out on a polyester film in accordance with Example 1 and light resistance was confirmed, almost no deterioration was observed in color density or thermochromic function after irradiation for 20 hours by a fade meter tester. In place of the yellow dextrin, branched cyclodextrin, sugar, glucose was applied to each system, a similar printed sample was prepared, and the same light fastness test was performed, and both systems showed similar light fastness performance. .

Example 5 35 parts by weight of thermochromic pigment, 20 parts by weight of polyacrylic acid oligomer (oxygen gas barrier resin) and 45 parts by weight of acrylic ester emulsion (solid content 40% by weight) were mixed to obtain thermochromic property. An ink was obtained [oxygen gas barrier resin / thermochromic pigment = 1.81 / 1.0 (solid content weight ratio), solid content ratio of oxygen gas barrier resin to the entire resin is 52.6%]. When solid printing was carried out on a polyester film in accordance with Example 1 and light resistance was confirmed, almost no deterioration was observed in color density or thermochromic function after irradiation for 20 hours by a fade meter tester. On the other hand, the printed matter using the thermochromic ink consisting of 35 parts by weight of the thermochromic pigment and 65 parts by weight of the acrylic ester emulsion was deteriorated by irradiation with the fade meter tester for 1 hour.

Example 6 30 parts by weight of thermochromic pigment, polyacrylic acid emulsion [oxygen gas barrier resin (a copolymer of 65% acrylic acid and 35% acrylic acid ester, partially using ammonia. Neutralized solid content 35% by weight)]
60 parts by weight, 2 parts by weight of a defoaming agent, and 8 parts by weight of a thickener were uniformly stirred and dispersed to obtain a thermochromic ink [oxygen gas barrier resin / thermochromic pigment = 1.17 / 1. 0 (solid content weight ratio)]. When solid printing was carried out on a polyester film in accordance with Example 1 and light resistance was confirmed, almost no deterioration was observed in color density or thermochromic function after irradiation for 20 hours by a fade meter tester.

Example 7 1.0 part by weight of a thermochromic pigment and an ethylene-vinyl alcohol copolymer [oxygen gas barrier resin (ethylene 40
% -Vinyl alcohol 60%)] 99 parts by weight,
The resin was kneaded at 190 ° C. to obtain a resin in which the thermochromic pigment was uniformly dispersed (oxygen gas barrier resin / thermochromic pigment = 9.
9.0 / 1.0 (solid content weight ratio)]. Then, a 2 mm-thick film was formed with a calendar roll. This film showed almost no deterioration in color density or thermochromic property after irradiation with a fade meter tester for 20 hours. On the other hand, a polyethylene film was used in place of the ethylene-vinyl alcohol copolymer to prepare a similar film, and a light resistance test was conducted using a fade meter tester. Lost.

[0026]

The light-resistant thermochromic resin composition of the present invention comprises
As shown in the above light resistance test results, the light fastness is remarkably improved, and the color-changing function of the thermochromic layer can be made permanent, and it can be used in the form of printed matter or coated matter, or in the form of resin molded body. It is applied to various fields such as temperature indication, decoration, advertisement, toys, stationery, teaching material elements, etc.

[0027]

[Brief description of drawings]

FIG. 1 is an enlarged vertical cross-sectional explanatory view of a light-resistant thermochromic resin composition of the present invention.

[Explanation of symbols]

1 Light-resistant thermochromic resin composition 2 Thermochromic pigment 3 Oxygen gas barrier resin

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 33/02 C08L 33/02 35/00 35/00 // C09K 9/02 C09K 9/02 C F term (Reference) 4F100 AJ03A AK01A AK21A AK21J AK24A AK24J AK25 AK25J AK27A AK27J AK41 AK80 AL01A AL05A AT00B CA13A DE04A DE04H EH46A GB84 GB90 JD03A JL09A JN28A JN28H011010010011H021H01H01H01H01H01H01H01H02H1H01H01H01H01H01H01H01H01H01H01H01H01H01H01H01H01HH1H01HH1H01HH1H00HH1H01HH1H00HH1H01HH1H01HH1H01HH1H01HH1H01HH1H01HH1H01HH1H01HH1H01HH1H1HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH of

Claims (7)

[Claims] 1. A thermochromic pigment having an average particle diameter of 0.5 to 30 μm is fixed in a dispersed state in an oxygen gas barrier resin to form a thermochromic resin layer. The light-resistant thermochromic resin composition, wherein the oxygen gas barrier resin in 1. is a continuous layer covering the outer surface of the thermochromic pigment. 2. The light-resistant thermochromic resin composition according to claim 1, wherein the thermochromic resin layer is a printing or coating layer formed on the surface of the support. 3. The light-resistant thermochromic resin composition according to claim 1, wherein the thermochromic resin layer is a resin molding itself formed by integrally blending thermochromic pigments. 4. The oxygen gas barrier resin comprises polyvinyl alcohol, a copolymer containing 50% or more of a polyvinyl alcohol component, a polycarboxylic acid, and a polycarboxylic acid.
The light-resistant thermochromic discoloration according to claim 1, which is selected from a copolymer containing 0% or more and an ammonium salt or a monovalent metal salt thereof, a copolymer containing 50% or more of an acrylonitrile component, a monosaccharide, and a polysaccharide. Resin composition. 5. The thermochromic pigment is (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) an organic compound medium that reversibly causes a color reaction between the both. The light-resistant thermochromic resin composition according to claim 1, which is a microcapsule-type thermochromic pigment containing a thermochromic composition containing at least three components. 6. The oxygen gas barrier resin / thermochromic pigment = 0.3 to 5.0 / 1.0 (weight ratio).
The light-resistant thermochromic resin composition described. 7. An oxygen gas barrier resin / thermochromic pigment = 0.3 to 100 / 1.0 (weight ratio).
The light-resistant thermochromic resin composition described.