JP3306604B2 - Thermochromic laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermochromic laminate. More specifically, in a thermochromic laminate that exhibits a white appearance when the color of the reversible thermochromic layer is decolorized, the color residue at the time of decoloring is difficult to see, and has light fastness. The present invention relates to a thermochromic laminate capable of clearly showing an image and a color tone of the laminate for a long period of time.

[0002]

2. Description of the Related Art Conventionally, a reversible thermochromic layer is provided on a support,
Several proposals have been disclosed for a laminate showing a color change due to a temperature change (for example, Japanese Utility Model Laid-Open No. 2-3859). In this type of thermochromic laminate, in a system set to exhibit white when the reversible thermochromic layer is decolorized,
The appearance after color development tends to be distinguished by slight residual colors and afterimages.Furthermore, if the appearance at the time of color development does not exhibit a clear image and its color tone, the taste and surprisingness due to color change will be reduced by half. This is a defect in a laminate for use in promoting the effect of a kind, and attempts have been made to blend a fluorescent whitening agent into a reversible thermochromic layer.

[0003]

However, even if the above-mentioned attempt has the effect of improving the whiteness, it does not absorb ultraviolet light on the reversible thermochromic layer in order to improve the light resistance of the reversible thermochromic layer. In a system provided with a layer, the fluorescent whitening effect is reduced by absorbing ultraviolet light. Also, even if some effect can be obtained by the addition of an excessive fluorescent whitening agent,
They tended to impair appearance and feel. An object of the present invention is to solve the problems of the conventional thermochromic laminate described above. That is, at the time of decoloring of the reversible thermochromic layer , it is difficult to visually recognize the residual color and the residual image, and has light fastness,
An object of the present invention is to provide a thermochromic laminate in which a clear image appearing in a color-developing state and the sensation of change due to its color tone and the unexpectedness can be enjoyed for a long period of time.

[0004]

Means for Solving the Problems The present invention, on a support,
Electron-donating color-forming organic compound, developer of the compound and
From a compound that is a medium that causes the color reaction between the two
A reversibly thermochromic layer containing thermochromic material comprising, laminating an ultraviolet absorbing resin layer containing an ultraviolet absorber in an upper layer of the reversible thermochromic layer, white color appearance of at decoloration of the reversibly thermochromic layer In the thermochromic laminate exhibiting color, the reversible thermochromic layer forms an image.
Form to become, and requirements thermochromic laminate which is characterized in that a fluorescent whitening resin layer containing a fluorescent whitening agent before Symbol ultraviolet absorbing resin layer. In the above, if necessary, an ultraviolet absorber may be blended in the reversible thermochromic layer and the fluorescent whitening resin layer.

[0005] The fluorescent whitening agent is a general fluorescent whitening dye,
Fluorescent whitening pigments are used, and those which disperse or dissolve in an oily or aqueous vehicle and have a fluorescent whitening effect are suitably used, and 0.1 to 50% by weight (preferably 1.0%) in the resin. -30% by weight). As an oil-soluble fluorescent whitening agent dispersed or dissolved in an oil-based vehicle, chlorin-based, thiophene-based, stilbene-based fluorescent whitening agents,
Fluorescent whitening pigment, the above-mentioned oil-soluble fluorescent whitening agent dissolved in an organic solvent or a non-volatile organic liquid, microencapsulated in an aqueous medium, isolated from an aqueous dispersion and subjected to a flushing process in an oily atmosphere, inorganic type And organic white, or colorless transparent, or colorless translucent pigment is dispersed in water, subjected to fluorescent whitening treatment with a water-soluble fluorescent whitening agent, isolated from the aqueous dispersion state and subjected to an oil-based flushing process, Disperse inorganic or organic white, colorless and transparent, or colorless and translucent microcapsules in water, subject them to fluorescent whitening with a water-soluble fluorescent whitening agent, isolate from the aqueous dispersion and flush them to an oily system And the like. Further, as a water-soluble fluorescent whitening agent dispersed or dissolved in an aqueous vehicle, a fluorescent whitening pigment, a water-dispersible fluorescent whitening pigment [Shi
genox FWP (manufactured by Hakkor Chemical Co., Ltd.)], an oil-soluble fluorescent whitening agent dissolved in an organic solvent or a non-volatile organic liquid and microencapsulated in an aqueous medium, and its isolated, inorganic and organic compounds. The white, or colorless and transparent, or a colorless and translucent pigment is dispersed in water, subjected to a fluorescent whitening treatment with a water-soluble fluorescent whitening agent, and then isolated, inorganic and organic white, colorless and transparent, or Colorless and translucent microcapsules are dispersed in water, subjected to a fluorescent whitening treatment with a water-soluble fluorescent whitening agent, and then isolated.

[0006] The fluorescent whitening agent dispersed in the oil-based or water-based vehicle is used to form a well-known printing layer on the reversible thermochromic layer.
Although the layers are laminated by a coating method, a film-like or sheet-like material obtained by integrally melting and blending a fluorescent whitening agent into a thermoplastic resin may be laminated.

The thermochromic material incorporated in the reversible thermochromic layer is, for example, an electron-donating color-forming organic compound, a color developer of the compound, and a medium for causing a color reaction between the two. Thermochromic material containing three components of a compound or thermochromic material exhibiting color change in the form of fine particles of a resin solid solution of the above components (for example, JP-B-51-35414, JP-B-51-44706, and JP-B-51-44706) 52-7776, Japanese Patent Publication No. 1-29898, etc.). In addition, Japanese Patent Publication No. 4-1715 proposed by the present applicant earlier.
The system described in Japanese Patent Application Publication No. 4 (1999) -A4, which is colored with a thermochromic material containing a color-memorizing thermochromic dye which exhibits large hysteresis characteristics and changes color, is also effective. The dye discolors with a large hysteresis width. That is, the shape of the curve plotting the change in the coloring density due to the temperature change is different from the case where the temperature is increased from a temperature lower than the color change temperature range to the case where the temperature is decreased from the temperature higher than the color change temperature range. It is a type that changes color following a very different path. As the reversible thermochromic material, a microcapsule pigment encapsulated in a microcapsule is preferably used in order to improve the sensitivity and sharpness of the color change.

As the thermochromic material, those exhibiting color to colorless or color to white containing a general white non-color-changing ink are preferably used.

The thermochromic material is dispersed in a medium containing a binder which is a film-forming material, applied as a coloring material such as ink or paint, and formed on the surface of a support, of course.
A thermochromic material encapsulated in microcapsules may be integrally melt-blended in a thermoplastic resin to form a film or a sheet. Further, a thermochromic film having a thermochromic layer itself may be laminated with a film in which a fluorescent whitening agent is melt-blended integrally in a dispersed state.

The support is preferably a white base material having printability, for example, paper, synthetic paper, fabric such as knitted fabric,
Flocked or raised cloth, nonwoven fabric, synthetic leather, leather, plastic, glass, ceramics, metal, wood, stone, and the like are used. Further, the shape is not limited to a flat shape, and may be a shape such as an uneven shape, a fiber shape, or the like. Further, a reversible thermochromic layer may be laminated after providing a layer containing a white non-color-changing ink even for a dark base material.

The laminate is formed by a conventionally known method, for example, printing means such as screen printing, offset printing, gravure printing, coater, tampo printing, transfer, brushing, spray coating, electrostatic coating, electrodeposition coating. , Flow coating, roller coating, dip coating, and the like. Also, it can be made into a film sheet and bonded.

[0012]

Since no layer containing a fluorescent whitening agent is provided below the ultraviolet absorbing resin layer, the function of fluorescent whitening due to absorption of ultraviolet light is not reduced. Particularly, in the system of the fluorescent whitening resin layer formed on the ultraviolet absorbing resin layer, the fluorescent whitening function is not reduced at all by the ultraviolet absorption, and the ultraviolet absorbing effect of the fluorescent whitening agent is added, so that the reversible thermochromic layer is added. It functions to effectively prevent a decrease in light resistance. Thus, a reversible thermochromic layer changing from color to colorless formed on a white support, or a reversible thermochromic layer changing from colored to white is formed on a support, and the thermochromic material in the reversible thermochromic layer is In the thermochromic laminate which exhibits white in the decolored state, the residual color and the afterimage are hardly seen, and the thermochromic function is normally operated for a long time.

[0013]

【Example】

[0014]

[0015]

Example 1 (see FIG. 1 ) Color memory thermosensitive coloring (pink →→ colorless, low temperature side)
(Discoloration point 17 ° C, high-temperature side discoloration point 30 ° C) 30 parts, vinyl chloride
20 parts of vinyl acetate copolymer resin, cyclohexanone 3
0 parts, aromatic medium boiling point solvent (Solvesso 100, Essification
30 parts) and 0.5 part of a silicone-based antifoaming agent
The color changes from pink to colorless, quasi-reversible, obtained by mixing and stirring.
Thermochromic material, and color notation in the composition of the thermochromic material
A heat-sensitive thermochromic dye with another color memory thermochromic dye
[(Orange ← → colorless, low temperature side discoloration point 17 ℃, high temperature side
Discoloration point 30 ° C) or (blue ← → colorless, low-temperature side discoloration point 1)
7 ° C, high temperature side discoloration point 30 ° C) or (green ← → colorless, low
(Discoloration point on the warm side 17 ° C, discoloration point on the hot side 30 ° C)]
The thermochromic material is screen-printed on a 0.1 mm thick white vinyl chloride sheet as a support 2 using a 180-mesh screen printing plate to form four color polka dots, thereby forming a reversible thermochromic layer 3. did. Note that, in the above embodiment,
“A” indicates parts by weight. The same applies to the following reference examples and comparative examples.
is there.

Further, 25 parts of a vinyl chloride-vinyl acetate copolymer resin, cyclohexanone 4
0 parts, 25 parts of an aromatic medium boiling point solvent, 0.5 parts of a silicone-based antifoaming agent, and 3 parts of a benzotriazole-based ultraviolet absorber [Tinuvin 326 (manufactured by Ciba Geigy)] were mixed and stirred.
Screen printing was performed using a 50-mesh screen plate to form an ultraviolet absorbing resin layer 5.

Further, on the upper surface of the ultraviolet absorbing resin layer 5, 50 parts of an acrylic polyol resin solution having a resin solid content of 50%, 10 parts of cyclohexanone, 20 parts of an aromatic medium boiling point solvent, 10 parts of an isocyanate curing agent, 10 parts of an acrylic defoamer Agent 0.5
Parts, fluorescent whitening pigment (Epocolor FP-101, manufactured by Nippon Shokubai Co., Ltd.), 10 parts were mixed and stirred, screen-printed using a 120-mesh screen plate, and heated and cured at 50 ° C. for 15 minutes. The fluorescent whitening resin layer 6 was formed, and the thermochromic laminate 1 was obtained.

At room temperature, the thermochromic laminate obtained as described above can simultaneously exhibit two states, that is, a state in which clear four-color polka dots appear and a state in which the entire surface is white. That is, after heating the entire surface to a white state by heating it to 30 ° C. or higher, it is left to cool down to ambient temperature, and then cooled to 15 ° C. or lower, a bright pink, orange, Blue and green polka dots appear as if they appeared, and are surprising. The polka dot pattern is maintained at room temperature, and when heated to 30 ° C. or more, the color is erased and the whole surface returns to a white state again, and can be used repeatedly.

Reference Example 1 Thermochromic material (reddish colorless colorless discoloration temperature 30 ° C.) 20
Part, 40 parts of an acrylic resin solution, 20 parts of xylene, and 20 parts of methyl isobutyl ketone were mixed and stirred, and a thermochromic spray ink obtained was spray-coated on a white ABS fixture as a support to form a reversible thermochromic layer. .

Further, on the upper surface of the reversible thermochromic layer, 40 parts of an acrylic resin solution and a cellulose acetate butyrate resin 1
0 parts, methyl isobutyl ketone 30 parts, xylene 20
Part, benzophenone UV absorber (Ubinal D-4)
9, GAF Co.) 5 parts of UV-absorber-containing topcoat ink obtained by mixing and stirring were coated with a thermochromic material A
Spray coating was performed on the fixture made of BS, followed by drying to form an ultraviolet absorbing resin layer.

Further, on the upper surface of the ultraviolet absorbing resin layer, 40 parts of an acrylic resin solution, 10 parts of cellulose acetate butyrate resin, 30 parts of methyl isobutyl ketone, xylene 2
0 parts, 1 part of an oil-soluble fluorescent whitening agent (PY-1800, manufactured by HAKKO CHEMICALS Co., Ltd.) is mixed and stirred, and a fluorescent whitening agent-containing topcoat ink is applied to form a fluorescent whitening resin layer, and heat discoloration is performed. A sex ABS fixture was obtained.

The thermochromic ABS object is colored vermilion below 30 ° C. When the molded product is heated to 30 ° C. or higher, it completely discolors to white and no residual vermilion is observed. , Similar to an unpainted white figurine.
Further, when the white ABS-made object was left standing and cooled, it was colored red again, and this change could be repeated many times.

Reference Example 2 30 parts of color-memory color thermosensitive color-changing dye (purple color → colorless low-temperature side color change point 15 ° C., high-temperature side color change point 32 ° C.), 50 parts of acrylic resin emulsion, silicone antifoaming agent 0.5 Department,
1 part of thickener, 1 part of cross-linking agent, and 20 parts of water are uniformly mixed and stirred to produce a thermochromic material that changes color from purple to colorless quasi-reversibly.
On a white cotton cloth that has been subjected to a fluorescent whitening treatment, solid printing is performed using a 109-mesh screen plate, and left to dry naturally,
A reversible thermochromic layer was formed.

Further, on the upper surface of the reversible thermochromic layer, 70 parts of an acrylate-based emulsion, 0.5 part of a silicone-based defoamer, 1 part of a thickener, 1 part of a crosslinking agent, and an aqueous dispersion of an ultraviolet absorber (Cibatex) LFN Ciba-Geigy) 5
Parts, water 20 parts and an oil-soluble fluorescent whitening agent [Kayalight
tB manufactured by Nippon Kayaku Co., Ltd.] with a phthalic acid plasticizer (DIN
P), microencapsulated in an aqueous medium using an interfacial polymerization method, and mixed with 10 parts of microcapsules containing a fluorescent whitening agent isolated from the aqueous medium to obtain a screen printing ink for a top coat. Screen-print the 7
The composition was heated and cured at 0 ° C. for 30 minutes to form an ultraviolet absorbing resin layer containing a fluorescent whitening resin layer, thereby obtaining a thermochromic cotton cloth.

The thermochromic cotton cloth obtained as described above can simultaneously exhibit two states, purple and white, at room temperature, and when exhibiting the purple colored state, there is no white turbidity.
A vivid purple color can be exhibited. In addition, when exhibiting a white state, a purple residual color is hardly visually recognized.

Comparative Example 1 (See FIG. 2 ) The thermochromic material obtained in Example 1 was screen-printed on a 0.1 mm thick white vinyl chloride sheet as a support 2 using a 180-mesh screen printing plate. To form a reversible thermochromic layer 3. Further, on the upper surface of the reversible thermochromic layer 3, 25 parts of a vinyl chloride-vinyl acetate copolymer resin, 40 parts of cyclohexanone, an aromatic medium boiling point solvent 2
5 parts, a silicone-based antifoaming agent 0.5 parts, and a benzotriazole-based ultraviolet absorber [Tinuvin 326 (manufactured by Ciba-Geigy)] 3 parts were mixed and stirred, and screen-printed using a 150-mesh screen plate, followed by UV-absorbing resin. Layer 5 was formed, and thermochromic laminate 1 was obtained.

Comparative Example 2 (See FIG. 3 ) The thermochromic material obtained in Example 1 was screen-printed on a 0.1 mm thick white vinyl chloride sheet as a support 2 using a 180-mesh screen printing plate. To form a reversible thermochromic layer 3. Further, on the upper surface of the reversible thermochromic layer, 50 parts of an acrylic polyol resin solution having a resin solid content of 50%, 10 parts of cyclohexanone, 20 parts of an aromatic medium boiling point solvent, 0.5 parts of an acrylic defoamer, and 10 parts of an isocyanate curing agent Part, fluorescent whitening pigment [Epocolor FP
-101, manufactured by Nippon Shokubai Co., Ltd.] and mixing and stirring 10 parts.
Screen printing was performed using a 120-mesh screen plate, followed by heating and curing at 50 ° C. for 15 minutes to laminate the fluorescent whitening resin layer 6, thereby obtaining a thermochromic laminate 1.

Comparative Example 3 (see FIG. 4 ) 30 parts of a color memory memorizing thermochromic dye (pink →→ colorless, low-temperature side color change point 17 ° C., high-temperature side color change point 30 ° C.), vinyl chloride-vinyl acetate copolymer resin 20 parts, cyclohexanone 2
5 parts, 25 parts of an aromatic medium boiling point solvent (Solvesso 100, manufactured by Esso Chemical), 0.5 part of a silicone antifoaming agent, and 10 parts of a fluorescent whitening pigment (Epocolor FP-101) were uniformly mixed and stirred. A thermochromic material that changes color from quasi-reversible from pink to colorless, and a color memory thermochromic dye in the composition of the thermochromic material, which is another color memory thermochromic dye [(orange ← → Colorless, low-temperature side color change point 17 ° C, high-temperature side color change point 30 ° C) or (blue ← → colorless, low-temperature side color change point 17 ° C,
The thermochromic material substituted by (high-temperature side discoloration point 30 ° C.) or (green →→ colorless, low-temperature side discoloration point 17 ° C., high-temperature side discoloration point 30 ° C.)] is applied to a support using a 180-mesh screen printing plate. 2, a four-color polka dot pattern is screen-printed on a 0.1 mm thick white vinyl chloride sheet,
A reversible thermochromic layer 7 containing a fluorescent whitening agent was formed. Further, on the upper surface of the reversible thermochromic layer 7 containing the fluorescent brightener, 25 parts of a vinyl chloride-vinyl acetate copolymer resin, 40 parts of cyclohexanone, 25 parts of an aromatic medium boiling point solvent, and 0.5 part of a silicone-based antifoaming agent And 3 parts of a benzotriazole-based ultraviolet absorber [Tinuvin 326 (manufactured by Ciba Geigy)] were mixed and stirred, and screen-printed using a 150-mesh screen plate to form an ultraviolet-absorbing resin layer 5 and a thermochromic laminate 1 I got Comparative Example 4 (see FIG. 5) The thermochromic material obtained in Example 1 was screened with a 180 mesh screen.
Using a printing plate, the support 2 has a thickness of 0.1 mm.
Screen printing four colors each on a white PVC sheet
A plurality of belt-like patterns were arranged in parallel to form a reversible thermochromic layer 3.
Further, on the upper surface of the reversible thermochromic layer, an resin having a resin solid content of 50% was applied.
50 parts of a cryl polyol resin solution, cyclohexanone 1
0 parts, aromatic medium boiling point solvent 20 parts, acrylic defoamer 0.
5 parts, fluorescent whitening pigment [Epocolor FP-101, Inc.
Nippon Shokubai] 10 parts, isocyanate-based curing agent 10 parts,
Benzotriazole UV absorber [Tinuvin 326,
Ciba-Geigy Co., Ltd.] 3 parts were mixed and stirred, and
Screen printing using a screen plate of
And heated and cured for 15 minutes, containing fluorescent whitening pigment
An ultraviolet absorbing resin layer 4 is formed to obtain a thermochromic laminate 1
Was.

The residual color and light of the test results in Example 1及 beauty Comparative Examples 1, for 4, was performed existence of residual color, and the light resistance test. The light resistance was determined by irradiating light with a fade meter for 8 hours, then visually observing the light deterioration, and visually observing the presence or absence of residual color. The test results are as follows.

[Table 1] The contents of the evaluation symbols in the table are as follows. Lightfastness ：: good △: slightly bad ×: bad presence of residual color ◎: no color ○: slight residual color when staring (almost no) Δ: slight residual color ×: residual color

[0031]

As described above, the thermochromic laminate of the present invention is white when the color of the reversible thermochromic layer is erased, so that the thermochromic image at the time of color development can be viewed with good contrast and the afterimage at the time of color erasing or Since the residual color is difficult to see, and the image at the time of color development and its various color tones can be maintained for a long period of time, it is possible to provide toys, sheets, writing objects, etc., which are surprising and rich in change. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of the thermochromic laminate of the present invention.

FIG. 2 is a cross section of one comparative example for the thermochromic laminate of the present invention .
The figure is shown.

FIG. 3 is a sectional view of another comparative example for the thermochromic laminate of the present invention .
FIG.

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

FIG. 5 is a sectional view of another comparative example for the thermochromic laminate of the present invention .
FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 thermochromic laminate 2 support 3 reversible thermochromic layer 4 ultraviolet absorbing resin layer containing fluorescent whitening agent 5 ultraviolet absorbing resin layer 6 fluorescent whitening resin layer 7 reversible thermochromic layer containing fluorescent whitening agent

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B41M 5/28-5/34 B32B 1/00-35/00 C09K 9/02 C09D 11/00-11/02

Claims (1)

(57) [Claims] 1. An electron donating color-forming organic compound on a support
Product, a color developer of the compound and a color reaction of the both.
Contains a thermochromic material consisting of
UV absorption on the reversible thermochromic layer and on the reversible thermochromic layer
Agent laminating an ultraviolet absorbing resin layer containing, in thermochromic laminate exhibiting the appearance of white color when decoloration of the reversibly thermochromic layer, reversibly thermochromic layer is to form an image, prior Symbol Purple A thermochromic laminate comprising a fluorescent whitening resin layer containing a fluorescent whitening agent provided on an external ray absorbing resin layer.