JPH06134915A - Thermally color-changeable laminate - Google Patents

Abstract

PURPOSE:To enhance the light fastness of the thermally discoloring layer of a system using a thermally color changeable material developing and losing a color by the giving and receiving reaction of an electron between an electron donating color forming org. compd. and an electron acceptive compd. CONSTITUTION:A thermally color-changeable laminate is obtained by laminating a light barrier pigment layer 3 wherein light barrier pigment selected from metal gloss pigment, transparent titanium dioxide, transparent iron oxide, transparent cesium oxide and transparent zinc oxide is fixed to a film forming material in a dispersed state on a thermal discoloring layer 2. Since the light barrier pigment layer 3 permitting even a proper quantity of visible light to transmit in a degree not obstructing visual sensation, the color change of the thermal discoloring layer 2 is also visually confirmed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermochromic laminate. More specifically, it relates to a thermochromic laminate with significantly improved light fastness.

[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. Further, as another attempt, there is an attempt to provide a light reflecting layer or a light absorbing layer on the upper layer of the thermochromic layer to suppress the reaching of the lower thermochromic layer by absorbing or reflecting ultraviolet rays or visible rays. is there. Yet another attempt is to apply a colored filter.

[0003]

However, each of the above proposals has the following disadvantages. In particular, in a system in which the thermochromic material contains an electron-donating color-developing organic compound and an electron-accepting compound, the electron-donating color-developing organic compound of the above-mentioned electron-donating color-changing organic compound can be obtained only by the means for cutting off the ultraviolet rays by the above-mentioned ultraviolet absorber or the like. Photodegradation cannot be completely prevented. Further, in order to obtain a sufficient effect in the system in which the light reflecting layer is provided, the layer becomes whitish, and it is difficult to sufficiently visualize the color change of the underlying thermochromic layer. On the other hand, in the system in which the light absorption layer is provided, the layer is dark or blackish in color, which obstructs the visual perception of color change of 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 visible, and it looks yellow and green. ← → Yellow, reversible color change is exhibited. 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 invention eliminates the problems of the above-mentioned conventional attempts,
It is intended to improve the light fastness remarkably, to make the color change of the thermochromic layer visible clearly, and further to make the color change of metallic luster tone such as gold color, silver color and metallic color visible.

[0004]

According to the present invention, a light-shielding pigment selected from metallic luster pigments, transparent titanium dioxide, transparent iron oxide, transparent cesium oxide and transparent zinc oxide is fixed in a dispersed state in a film forming material. The thermochromic laminated body in which the light shielding pigment layer is laminated on the thermochromic layer is required. Furthermore, the thermochromic layer comprises a thermochromic material dispersed in a film-forming material, the thermochromic material comprising an electron-donating color-forming organic compound, an electron-accepting compound, and an organic compound medium that reversibly causes a color reaction between the both. A thermochromic laminate that is a layer fixed in a state, further, an ultraviolet absorber, an antioxidant, an antioxidant, a singlet oxygen quencher, a superoxide anion quencher, an ozone quencher, a visible light absorber, Selected from infrared absorbers,
A thermochromic laminate in which a light stabilizer layer in which a light stabilizer is fixed in a dispersed state in a film-forming material is laminated on a light-shielding pigment layer or interposed between a thermochromic layer and a light-shielding pigment layer. It is characterized by the body. In the above, more specifically, the metallic luster pigment is a golden metallic luster pigment having a particle size of 5 to 60 μm in which the surface of natural mica is coated with 41 to 44% by weight of titanium oxide, and the surface of natural mica is 30 to 38% by weight. Of 0.5 to 10% by weight of a non-thermochromic colored pigment, and a golden luster pigment having a particle size of 5 to 60 μm. The surface of natural mica is 16 to 39% by weight of titanium oxide. With a particle size of 5 to 60 μm of a silver metallic luster pigment, a surface of natural mica with 45 to 58% by weight of titanium oxide, a metallic metallic luster pigment coated with 45 to 58% by weight of titanium oxide. Metallic metallic luster pigment coated with 4-10% by weight of iron oxide on it, the surface of natural mica is coated with 45-58% by weight of titanium oxide, and 0.5-10% by weight on it. Non-thermochromic colored Pigment can be a mention the coated metallic color metallic luster pigment.

For the thermochromic layer, a thermochromic material containing three components, an electron-donating color-forming compound, an electron-accepting compound, and an organic compound medium that reversibly causes a color reaction is used. Specifically, for example, thermochromic materials described in JP-B-51-35414, JP-B-51-44706, JP-B-1-17154 and the like, that is, (1) (a) electron A reversible thermochromic material comprising as essential components three components: a donative color-developing organic compound, (b) a compound having a phenolic hydroxyl group, and (c) a chain type aliphatic monohydric alcohol having no polar substituent. Alternatively, (2) (a) an electron-donating color-forming organic compound, (b) a compound having a phenolic hydroxyl group, and (c) an aliphatic monohydric alcohol having no polar substituent and a polar substituent. A reversible thermochromic material containing, as an essential component, three components of a compound selected from an ester having no polar substituent obtained from an aliphatic monocarboxylic acid. Alternatively, (3) (a) an electron-donating color-developing organic compound, (b) a compound having a phenolic hydroxyl group, (c) a higher aliphatic monohydric alcohol having no polar substituent, and a polar substituent Three components of a compound selected from any one of an aliphatic monocarboxylic acid having no substituent and an ester having no polar substituent obtained from a chain type aliphatic monohydric alcohol having no polar substituent are essential components. And a reversible thermochromic material containing this in microcapsules. Alternatively, (4) (a) an electron-donating color-developing organic compound, (b) a compound having a phenolic hydroxyl group, (c) a higher aliphatic monohydric alcohol having no polar substituent, and a polar substituent As an essential component, three components of a compound selected from an ester having no polar substituent obtained from an aliphatic monocarboxylic acid having no and a chain aliphatic monohydric alcohol having no polar substituent, A thermochromic material obtained by dissolving or dispersing this in a vehicle. Etc.

In addition to this, Japanese Patent Publication No. 4-1 proposed by the present applicant
No. 7154, a thermochromic material containing a color-memory thermosensitive color-changing dye that exhibits a large hysteresis characteristic, that is, the shape of a curve plotted in which the change in the coloring density due to temperature changes is plotted. It is a type of color change material that changes color when it goes down from a temperature lower than the temperature range and when it goes down from a temperature higher than the color change temperature. A thermochromic material is also used which has a characteristic of being capable of storing and retaining a state of being changed at a temperature below the low temperature side color changing point or above the high temperature side color changing point in a normal temperature range between the color changing points. The thermochromic material described above can be usually applied by encapsulating it in microcapsules, but it is also effective if it is applied as it is without encapsulating it in microcapsules. The thermochromic material is dispersed in a medium containing a binder, which is a film-forming material, and applied as a coloring material such as ink or paint, and can form a thermochromic layer in the form of a coating layer or a coating film, and a thermoplastic resin. In the resin of
The thermochromic material encapsulated in the microcapsules may be integrally melt-blended to form a film or sheet.

The thermochromic layer is not limited to the sheet-like shape, and the thermochromic material encapsulated in microcapsules is dispersed in a thermoplastic or thermosetting resin and contained in a fixed state. It may be a molded product whose surface is a thermochromic layer. The thermochromic material mentioned above may be added to the film-forming material, thermoplastic resin, or thermosetting resin in an amount of 0.
It may be contained in an amount of 5 to 40% by weight, preferably 1 to 30% by weight. A blending amount of less than 0.5% by weight makes it difficult to visually perceive a clear thermochromic effect, and a blending amount of more than 40% by weight results in an excessive amount and a residual color in a decolored state. The light-shielding pigment layer can be dispersed in a medium containing a binder that is a film-forming material to form a coating layer to form a coating layer, or can be integrally blended in a thermoplastic resin. It may be in the form of a film or a sheet. The light-shielding pigment has a uniform dispersibility by dispersing and fixing in the film-forming material a proportion of 0.1 to 40% by weight, preferably 5 to 30% by weight, of the pigment having a particle size of 5 to 100 μm. The desired concealment effect can be achieved.

Next, film forming materials will be exemplified below. Ionomer resin, isobutylene-maleic anhydride resin copolymer resin, acrylonitrile-acrylic styrene copolymer resin, acrylonitrile-styrene copolymer resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile chlorinated polyethylene-styrene copolymer resin,
Ethylene-vinyl chloride copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl acetate-vinyl chloride graft copolymer resin, vinylidene chloride resin, vinyl chloride resin, chlorinated vinyl chloride resin, vinyl chloride-vinylidene chloride copolymer resin , Chlorinated polyethylene resin, chlorinated polypropylene resin, polyamide resin, high density polyethylene resin, medium density polyethylene resin, linear low density polyethylene resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polycarbonate resin, polystyrene resin, high impact polystyrene resin, Polypropylene resin, polymethylstyrene resin, polyacrylic acid ester resin, polymethylmethacrylate resin, epoxy acrylate resin, alkylphenol resin, rosin-modified phenol resin , Rosin modified alkyd resin, phenolic resin modified alkyd resin, epoxy resin modified alkyd resin, styrene modified alkyd resin, acrylic modified alkyd resin, amino alkyd resin, vinyl chloride-vinyl acetate resin, styrene-butadiene resin, epoxy resin, unsaturated polyester Resin, polyurethane resin, vinyl acetate emulsion resin, styrene-butadiene emulsion resin, acrylic ester emulsion resin, water-soluble alkyd resin, water-soluble melamine resin, water-soluble urea resin, water-soluble phenol resin, water-soluble epoxy resin, Examples thereof include water-soluble polybutadiene resin, cellulose acetate, nitrate cellulose, ethyl cellulose and the like. Among the above film-forming materials, a film-forming material for forming a coating layer is the above-mentioned alkylphenol resin, rosin-modified phenol resin, rosin-modified alkyd resin, styrene-modified alkyd resin, acryl-modified alkyd resin, aminoalkyd resin, vinyl chloride. -Vinyl acetate resin, styrene-butadiene resin, epoxy resin, acrylic ester resin, unsaturated polyester resin, polyurethane resin, vinyl acetate emulsion resin, styrene-butadiene emulsion resin, acrylic ester emulsion resin, water-soluble alkyd resin , A water-soluble melamine resin, a water-soluble urea resin, a water-soluble phenol resin, a water-soluble epoxy resin, a water-soluble polybutadiene resin, a cellulose derivative and the like, which can be applied after being dissolved or dispersed in water or an organic solvent. Next, as a film forming material for forming a film or a sheet, among the above film forming materials, an ionomer resin, isobutylene-maleic anhydride resin copolymer resin,
Acrylonitrile-acrylic styrene copolymer resin,
Acrylonitrile-styrene copolymer resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile chlorinated polyethylene-styrene copolymer resin, ethylene-vinyl chloride copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl acetate-vinyl chloride graft Copolymer resin, vinylidene chloride resin, vinyl chloride resin, chlorinated vinyl chloride resin, vinyl chloride-vinylidene chloride copolymer resin, chlorinated polyethylene resin, chlorinated polypropylene resin, polyamide resin, high density polyethylene resin, medium density polyethylene resin, Linear low density polyethylene resin,
Polyethylene terephthalate resin, polybutylene terephthalate resin, polycarbonate resin, polystyrene resin, high impact polystyrene resin, polypropylene resin, polymethylstyrene resin, polyacrylic ester resin, polymethylmethacrylate resin, epoxy resin, epoxy acrylate resin, alkyd resin, polyurethane Examples of the resin include resins. The laminate of the present invention is a system formed on the surface of a substrate, and of course, a light-shielding pigment is dispersed in a thermochromic film having a thermochromic layer, which is obtained by integrally melt-blending thermochromic materials in a dispersed state. A film obtained by integrally melt-blending the film may be laminated and united.

The substrate may be a film or sheet of various types, as well as a molded product itself shaped into a certain shape. As the base material, paper, synthetic paper, cloth, non-woven fabric, synthetic leather, leather, plastic, glass, ceramics, metal, wood, stone, etc. are used. Further, the shape is not limited to a flat shape, and may be an uneven shape, a fibrous shape or the like.

The laminate can be formed by a conventionally known method, for example, printing means such as screen printing, offset printing, gravure printing, coater, tampo printing, transfer, brush coating, spray coating, electrostatic coating, electrodeposition coating. It can be performed by means such as, flow coating, roller coating, dip coating and the like. Further, it is also possible to form a film sheet by extrusion molding or the like and bond them together, or integrally form the thermochromic layer and the light shielding pigment layer by multilayer molding. Incidentally, ultraviolet absorbers, antioxidants, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers, visible light absorbers,
The light stabilizer layer in which a light stabilizer selected from infrared absorbers is fixed in a dispersed state can be formed according to the preparation of the thermochromic layer or the light shielding pigment layer described above. The thermochromic layer described above,
By appropriately mixing non-thermochromic colored dyes and pigments, the color change of the thermochromic layer can be variously configured. In addition, images such as characters and patterns may be arranged below the thermochromic layer to hide these images.

[0011]

The light-shielding pigment layer of the present invention has both a light-absorbing (or light-reflecting) function and a light-transmitting function, and at least one of ultraviolet rays and visible rays which adversely affects the function deterioration of the thermochromic layer. Absorbs or reflects a part. Thus, the light resistance of the thermochromic layer can be dramatically improved, and an appropriate amount of visible light can be transmitted, and the color change of the thermochromic layer can be effectively visualized. . This point will be described for a system to which a metallic luster pigment is applied. Near-ultraviolet rays and blue visible rays (which have the shortest wavelength and high energy among visible rays) which are thought to have a great influence on the photodecomposition of the electron-donating color-forming organic compound that develops blue in the thermochromic pigment To cut. The metallic luster pigment itself has a property of blocking ultraviolet rays to some extent, and further has a property of selectively reflecting blue light and transmitting yellow light. In addition, regarding the thermochromic characteristics, when the thermochromic pigment exhibits a blue color, the electron-donating color-developing organic compound absorbs yellow light, reflects blue light, and passes through the metallic luster pigment. Light is also reflected by the thermochromic pigment layer. As a result, all wavelengths are reflected and appear colorless. Therefore, the change of blue ← → colorless is retained. This phenomenon is a phenomenon that is not possible in a system using a conventional coloring filter, and it also functions to cut a part of visible light and make the decolored state colorless and improve the light resistance. In the system of the metallic luster pigment, an iris effect caused by the selective interference of visible light, a correlation between the transmission effect and the brightness of the thermochromic layer, gold color,
It is also possible to give a color change from silver color, metallic color or the like.

[0012]

[Examples] Specific examples of the thermochromic laminate of the present invention will be described below, and the results of light resistance tests conducted in comparison with Comparative Examples will be described. In addition, "parts" in the following description means "parts by weight". (1) Composition of Thermochromic Pigment and Its Color Change Property Table 1 shows the composition of the thermochromic pigment (A to F) applied to each thermocolor layer of Examples 1 to 26 and Comparative Examples 1 to 6 and its color change property. Described in.

[Table 1] The thermochromic pigment is an electron-donating color-developing organic compound, an electron-accepting compound, a three-component homogeneous compatible solution of an organic compound medium for controlling the color change temperature, which is prepared according to a known microencapsulation method. Capsule pigments, which are pigments of a system in which low-temperature side and high-temperature side color change points are described as color change temperatures, exhibit color memory thermochromism. (2) Preparation Method of Examples and Comparative Examples Preparation of Laminates of Examples 1 to 18 Thermochromic pigment 10 parts, 50% acrylic resin / xylene solution 45 parts, xylene 20 parts and methyl isobutyl ketone 20 parts were stirred, The mixture was mixed and spray coated on a white vinyl chloride sheet with a spray gun to provide a thermochromic layer having a thickness of about 40 μm. Next, 1 part of the light-shielding pigment, 45 parts of 50% acrylic resin / xylene solution, 20 parts of xylene and 20 parts of methyl isobutyl ketone are stirred and mixed, and spray-painted on the thermochromic layer with a spray gun to a thickness of about A 40 μm light-shielding pigment layer was provided. Preparation of Laminates of Examples 19-26 On the light-shielding pigment layer of the laminates of Examples 1-18, an appropriate amount of light stabilizer, 50% acrylic resin / xylene solution 45.
Parts, 20 parts of xylene, and 20 parts of methyl isobutyl ketone were stirred and mixed, and a spray coating solution was sprayed with a spray gun to provide a light stabilizer layer having a thickness of about 35 μm. (3) Light resistance test method In a test sample before light irradiation, the density at the time of coloring and the density at the time of erasing were measured as lightness with a color difference meter, and the difference in lightness was 10
Converted to 0% to obtain concentration, 0, 20, 40, 60, 8
The lightness at the time of coloring when irradiated with light for 0 and 100 hours was measured, and the attenuation rate of the density decrease relative to 100% was measured.
A carbon arc fade meter was used for this test. (4) Contents of each example and comparative example and light resistance test results Tables 2 to 4 show the above contents and light resistance test results.

[Table 2]

[Table 3]

[Table 4]

[0013]

EFFECTS OF THE INVENTION The thermochromic laminate of the present invention has markedly improved lightfastness as seen in the results of the lightfastness test described above, and the thermochromic layer can continue to have the color changing function. Further, since the light-shielding pigment layer transmits visible light as well as an appropriate amount that does not impair the visual sense, the color change of the thermochromic layer can be effectively visualized. Thus, it is possible to provide a thermochromic laminate suitably applied to various fields such as toys, decorations, teaching materials, stationery, textiles, household items, various printed matters, and the like.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an example of a thermochromic laminate of the present invention.

FIG. 2 is a vertical cross-sectional view of another embodiment of the thermochromic laminate of the present invention.

FIG. 3 is a vertical cross-sectional view of another embodiment of the thermochromic laminate of the present invention.

FIG. 4 is a vertical cross-sectional view of another application example of the thermochromic laminate of the present invention.

[Explanation of symbols] 1 thermochromic laminate 2 thermochromic layer 3 light-shielding pigment layer 4 light stabilizer layer 5 printed image

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B32B 27/20 A 6122-4F B41M 5/26

Claims (3)

[Claims] 1. A light-shielding pigment layer comprising a light-shielding pigment selected from metallic luster pigments, transparent titanium dioxide, transparent iron oxide, transparent cesium oxide, and transparent zinc oxide fixed in a dispersed state in a film-forming material, A thermochromic laminate formed by laminating on a thermochromic layer. 2. The thermochromic layer comprises a thermochromic material comprising an electron-donating color-forming organic compound, an electron-accepting compound, and an organic compound medium that reversibly causes a color reaction between the both, and dispersed in the film-forming material. The thermochromic laminate according to claim 1, which is a layer fixed in a state. 3. A film containing a light stabilizer selected from an ultraviolet absorber, an antioxidant, an antioxidant, a singlet oxygen quencher, a superoxide anion quencher, an ozone quencher, a visible light absorber and an infrared absorber. 3. The heat discoloration according to claim 1, wherein the light stabilizer layer fixed in a dispersed state in the forming material is laminated on the light shielding pigment layer or interposed between the heat discoloration layer and the light shielding pigment layer. Laminate.