JP2587384Y2 - Reversible thermochromic laminate - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a reversible thermochromic laminate. More specifically, the present invention relates to a reversible thermochromic laminate that allows different printed images to be revealed by a change in temperature. More specifically, the present invention relates to a reversible thermochromic laminate in which a printed image formed on a surface layer of gold, silver or other metallic color is visually recognized, and a printed image provided below the surface layer is hidden by a change in temperature.

[0002]

2. Description of the Related Art Conventionally, a thermochromic material including a thermochromic material which exhibits a reversible color change of a color ← → colorless and a color [1] ← → color [2] by a temperature change is known. Several proposals have been made with respect to thermochromic prints that are covered with a concealing layer to make the printed image concealed (for example, Japanese Utility Model Laid-Open No. 59-68972).

[0003]

In the above-described conventional thermochromic concealment printing system, the thermochromic concealment layer concealing a printed image to be concealed has a relatively high visual density at the time of color development. It is necessary that the relationship of the visual density be satisfied or that the color tone at the time of color development be a combination of the same system as the color tone of the print image to be concealed, and the degree of freedom of the combination of the color and the density between the two is lacking. The present invention solves the above-mentioned conventional problems, conceals a base image by a shielding layer exhibiting a concealing property and a unique color tone, and further forms another printed image different from the base image on the shielding layer. Appearance of various concealed printed images on the groundwork, remarkable enhancement of unexpectedness, decorativeness, etc. by combining with the printed image on the surface layer, etc., applied to various fields such as toy field, interior field, decoration field etc. And a reversible thermochromic laminate that can be developed.

[0004]

The reversible thermochromic laminate of the present invention will be described with reference to the drawings (see FIGS. 1 to 3). The reversible thermochromic laminate 1 of the present invention is a laminate having a configuration in which different printed images are concealed by a change in temperature, and is a thermochromic concealment that covers the first printed image 3 formed on the surface of the support 2. A layer 4 is provided, a metallic luster pigment layer 5 is laminated on the thermochromic hiding layer 4, and a second printed image 6 is provided on the metallic luster pigment layer 5. Further, the metallic luster pigment layer 5
Is required to be a layer in which a silver metallic luster pigment is fixed to a transparent resin in a dispersed state. In the above, the support 2 may be any material having printability or applicability, and is not limited to sheet materials such as paper, plastic sheet, cloth, non-woven fabric, leather, etc., but may be glass, ceramics, metal, wood, stone, plastic, or the like. Various base materials suitable for the purpose, such as a molded body made of a material, are effective. The first printed image 3 is not limited to a color image formed of a non-thermochromic dye and pigment, but may be a thermochromic image formed of a thermochromic material. In addition, the second printed image 6 may be a thermochromic image or a colored image using a non-thermochromic dye / pigment. The print image 3 or the print image 6 is not limited to the print image as it is, but may be formed by painting, spraying, or the like.

The thermochromic concealing layer 4 and the thermochromic material forming the thermochromic image include known electron-donating color-forming organic compounds,
A thermochromic material containing three components of an electron-accepting compound and an organic compound medium that reversibly causes a color reaction between the two, or a thermochromic material exhibiting thermochromic properties in the form of fine particles of a resin solid solution of the component ( For example, Japanese Patent Publication No. 51-35414, Japanese Patent Publication No. 51-44706, and Japanese Patent Publication No. 1-29.
398, etc.). In addition, a thermochromic material containing a color-memorizing thermochromic dye exhibiting large hysteresis characteristics and discoloring, that is, a thermochromic material disclosed in Japanese Patent Publication No. Hei. The shape of the curve on which the change is plotted changes color following a significantly different path between when the temperature is increased from a temperature lower than the color change temperature range and when it is decreased from a temperature higher than the color change temperature range. In a normal temperature range between the low-temperature-side discoloration point and the high-temperature-side discoloration point, an aspect in which the temperature is changed at a temperature equal to or lower than the low-temperature-side coloration point or equal to or higher than the high-temperature-side coloration point can be stored and stored.

The thermochromic material described above is usually encapsulated in a microcapsule and dispersed in a resin-containing medium.
As the ink or paint, the second printed image 6 (or the first
To form a printed image 3) and a thermochromic hiding layer 4. The metallic luster pigment layer 5 is a layer in which the metallic luster pigment is fixed in a transparent resin in a dispersed state, and is usually formed by applying an ink or a paint in which the metal pigment is dispersed in a resin-containing medium. The thickness of the layer 5 is 10 to 400 μm, preferably 15 to 300 μm, and the content of the metallic luster pigment in the layer is 0.1 to 40% by weight (preferably 0.5 to 30% by weight). Provides a great hiding effect, light reflection effect, and light transmission effect. As the resin in the above, a general-purpose resin conventionally applied to paints, printing inks and the like is effective, and is selected and applied according to the purpose. The metallic luster pigment in the above, specifically, the surface of natural mica particles coated with titanium oxide, gold, silver, metallic red, metallic purple, metallic blue, metallic green pigment, the surface of the natural mica particles titanium oxide And an upper layer thereof coated with iron oxide. More specifically, the metallic luster pigment is obtained by coating the surface of natural mica particles with 41 to 44% by weight of titanium oxide.
An optical layer having an optical thickness of 180 to 240 nm and a particle size of 5 to 60 μm, or a surface of natural mica particles coated with 30 to 48% by weight of titanium oxide and an upper layer coated with 4 to 10% by weight of iron oxide. Target thickness 180 ~ 240nm, particle size 5 ~
The 60 μm gold and silver metallic luster pigments are obtained by coating the surface of natural mica particles with 16 to 39% by weight of titanium oxide, having an optical thickness of 110 to 170 nm and a particle size of 5 to 10%.
0 μm. Here, optical thickness = refractive index × geometric thickness. The metallic red metallic luster pigment has a surface of natural mica particles of 45 to 47.
245-2 optical thickness coated with wt% titanium oxide
75 nm, metallic purple metallic luster pigment,
A metallic blue metallic luster pigment having an optical thickness of 280 to 310 nm, in which the surface of natural mica particles is coated with 48 to 50% by weight of titanium oxide, has a surface of 51 to 54% by weight of titanium oxide. The metallic green luster pigment having an optical thickness of 315 to 350 nm coated with the above is selected from those having an optical thickness of 375 to 415 nm in which the surface of natural mica particles is coated with 55 to 58% by weight of titanium oxide. And a pigment having a particle size of about 5 to 60 μm. Further, as the metallic luster pigment, a dichroic metallic luster pigment in which the surface of natural mica particles is coated with titanium oxide and the upper layer is coated with an organic pigment may be used. The metallic luster pigment having the above-mentioned specific physical property values, except for a silver metallic luster pigment that transmits and reflects all wavelengths at a specific ratio, selectively transmits light of a certain wavelength and reflects light of a wavelength having a complementary color relationship. Has the property of Outside the range of the specific physical property value, the wavelength selectivity is lost, or the desired color is not obtained even though the wavelength selectivity exists.

The thermal color hiding layer 4 and the metallic luster pigment layer 5
The conventionally known methods, for example, screen printing, offset printing, gravure printing, coater, tampo printing,
It can be performed by a printing means such as transfer, brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, dip coating, or the like.

[0008]

The first printed image 3 concealed by the thermochromic concealing layer 4 and the metallic luster pigment layer 5 laminated thereon is concealed by a change in temperature. At this time, the color change of the thermochromic hiding layer 4 is visually recognized through the metallic luster pigment layer 5,
By applying the metallic luster pigment having the specific physical property values described above,
Various color changes in metallic luster are visualized by the synergistic effect of the iris effect and the transmission effect caused by the selective interference effect of the wavelength of visible light and the visible light reflection and absorption effect of the lightness value of the thermochromic layer.

More specifically, the reflected light at the time of interference varies depending on the coating weight% of the titanium oxide, that is, the thickness of the coating layer. For example, titanium oxide-coated mica prepared so as to selectively reflect yellow light and transmit blue light has a black base, the transmitted blue light is absorbed by the black base, and the yellow light Only the reflection reflects gold. On the other hand, when the base is white, the transmitted blue light is also reflected by the white of the base, reflects not only yellow light but also blue light, and reflects all wavelengths of visible light. You. Therefore, by reversibly changing the lower thermochromic concealing layer 4 from black to white, the reversible color change from silver to white is visually recognized. The metallic luster pigment layer 5 of the present invention is particularly effective with a silver luster pigment system, and this system will be described. Titanium oxide-coated mica, which has been adjusted to absorb all parts of the incident light at all wavelengths and reflect the rest, is reflected in the same direction without irregularly reflecting the reflected light due to the layered nature of the mica. Therefore, silver color is displayed instead of gray. The silver metallic luster color is an achromatic color and can maintain the brightness (whiteness) as compared with a normal thermochromic concealing layer, and thus has a feature that a second image can be formed in any color on the upper layer. Therefore, when the thermochromic hiding layer 4 is colored, the first printed image 3 under the thermochromic hiding layer 4 can be formed without any color limitation. Next, when the second print image 6 (in the case of a thermochromic image) is erased and the thermochromic concealment layer 4 is erased at the same time, the silver color is erased and the first printed image 3 of the base appears. In this phenomenon, the pattern changes completely before and after the change, and the image can be changed as if turning a page. On the other hand, in the conventional concealing means using only the thermochromic concealing layer, the concealing layer is black or a dark dark color and conceals a non-concealed image (corresponding to the first printed image 3). It is difficult to form various images in the state,
By forming some image at best with a silhouette,
It was just a substitute for the image. Incidentally, when the metallic gloss pigment is in a system such as metallic red, metallic purple, metallic blue, metallic green, etc., various color changes from the metallic gloss color are visualized by the same action as above, and a concealing effect is exerted. .

Although the visual appearance of the first printed image 3 (characters, patterns, etc.) is hindered in the colored state of the thermochromic hiding layer 4, the hiding effect is remarkably improved by the light reflection effect of the metallic luster pigment layer 5. The second printed image 6 formed on the metallic luster pigment layer 5 is
When the color change temperature of the thermochromic concealing layer 4 is the same as the color change temperature of the thermochromic concealing layer 4, the first print image 3 appears simultaneously with the decolorization of the second print image 6. In a combination of the second thermochromic printed image 6 and the thermochromic concealing layer 4 having different color changing temperatures, more visual changes are exhibited. When the second print image 6 is a non-thermochromic print image, the first print image 3 is visualized in addition to the visual sense of the print image 6, and an image formed by combining both images is visualized. The aspect of the visual change due to the temperature change is reversible and is repeatedly reproduced.

[0011]

EXAMPLES Example 1 (see FIGS. 1 to 3) A printed image 3 of a butterfly is formed on a white high-quality paper 2 using a commercially available non-thermochromic screen ink of yellow, pink and blue. Discolorable pigment [black ← → colorless, discoloration temperature 30 ° C (3
The color discolored reversibly to black at 0 ° C. or less and reversibly to colorless at 30 ° C. or more) using a thermochromic screen ink composed of a dispersion of about 40 μm in thickness, covering the printed image 3 of the butterfly. The property hiding layer 4 was formed by screen printing. Next, using a screen ink containing a silver metallic luster pigment,
A metallic luster pigment layer 5 having a thickness of about 40 μm and covering the thermochromic hiding layer 4 was formed by screen printing. Then
Thermochromic screen ink and thermochromic pigment (green ← → colorless, color change temperature of 30 ° C.) comprising a dispersion of thermochromic pigment (pink →→ colorless, color change temperature of 30 ° C.) on the metallic luster pigment layer 5 The print image 6 of the caterpillar was screen-printed using a thermochromic screen ink consisting of the dispersion of In the obtained printed matter 1, the printed image 6 of green and pink caterpillars is visually recognized in the silver layer at room temperature, but when the whole is heated to 30 ° C. or more, the printed image 6 of the caterpillar becomes invisible and the silver layer becomes invisible. Disappeared, and the printed image 3 of the butterfly appeared. When the printed image 3 of the butterfly is left at room temperature for a while, the printed image 4 of caterpillars
The caterpillar ← → butterfly image could be reversibly visualized by the temperature change.

Example 2 A commercial aircraft design was formed on the surface of a styrene airplane toy by spray coating with commercially available non-thermochromic paints of white, fluorescent yellow and fluorescent pink. Next, a thermochromic color memory pigment (black ← → colorless, low temperature side: 15
C., high-temperature side: 35.degree. C.) was spray-coated on the entire surface of the aircraft to form a thermochromic concealment layer having a thickness of about 40 .mu.m. Next, a spray paint containing a silver gloss pigment was spray-coated on the thermochromic concealing layer to form a silver metallic gloss layer having a thickness of about 35 μm. In addition, a thermochromic color memory pigment (blue ← → colorless, low temperature side: 15 ° C., high temperature side 3)
(5 ° C.) to form a military aircraft design by spray painting with a thermochromic color memory paint consisting of a dispersion. The resulting airplane toy, when cooled below 15 ° C., changed to a military aircraft design, which was maintained at room temperature. Then, when heated above 35 ° C., the design of the military aircraft in silver and blue disappeared, and the design of civil aircraft in fluorescent yellow and pink in white appeared, and this design was maintained at room temperature.

Example 3 The letters "cat" are printed on a white PVC sheet with a light pink non-thermochromic oil-based screen ink.
Then, a thermochromic pigment (red →→ colorless, color change temperature 40)
C) was printed using a thermochromic screen ink comprising a dispersion of (C) so as to cover the character "cat". Next, a thermochromic pigment (black ← → colorless, color change temperature 3
(0 ° C.) using a thermochromic screen ink composed of a dispersion, and screen-printed on a cat pattern (thermochromic concealing layer) to form a thermochromic concealing layer. Next, a silver metallic luster pigment layer was formed using a silver metallic luster pigment-containing screen ink. Next, the letters "CAT" were screen-printed on the silver metallic luster pigment layer using a thermochromic screen ink consisting of a dispersion of a thermochromic pigment (blue →→ colorless, color change temperature 30 ° C.). At room temperature, at room temperature, the letters “CAT” were visually recognized in blue on silver, but when the whole was heated to 30 ° C. or more, the letters “CAT” disappeared.
A red cat pattern appeared. Further, when the temperature was raised to 40 ° C. or higher, the design of the red cat disappeared, and the letters of “pink” appeared in light pink. The character of the "cat" returns to a red cat pattern after a while, then returns to a blue "CAT" character, and the visual and invisible aspects of the "CAT", the cat pattern, and the "cat" character The change was reversibly reproduced by the temperature change.

[0014]

According to the thermochromic laminate of the present invention, a metallic luster pigment layer is laminated on a thermochromic opaque layer, and the opacity is significantly improved by the reflection and transmission characteristics of the metallic luster pigment layer. As a result, the thermochromic concealing layer can be formed in black or dark color having a high concealing property, giving a degree of freedom in selecting the color, density, etc. of the underlying printed image. The metallic luster pigment layer can be selected from gold, silver, and other metallic colors, and together with the specificity of the color, further enhances the concealment effect of the base. Further, an appropriate image can be formed on the metallic luster pigment layer so that the image can be visually recognized. In particular, if a metallic luster layer having a silver color is applied, printed images of various colors and densities can be formed on the layer without any restrictions on the color and density. Thus, it is possible to provide a reversible thermochromic laminate that can be applied to various fields such as toys, decorations, educational materials, stationery, textiles, household goods, and printed matter.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the reversible thermochromic laminate of the present invention.

FIG. 2 is an explanatory plan view showing a state in which a second print image is visually recognized.

FIG. 3 is an explanatory plan view showing a state in which a second print image has been erased and the first print image has been visually recognized;

[Explanation of symbols]

 Reference Signs List 1 thermochromic laminate 2 support 3 first printed image 4 thermochromic concealing layer 5 metallic luster pigment layer 6 second printed image

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁶ Identification code FI C09D 5/29 C09D 7/12 7/12 B41M 5/18 114 (56) References JP-A-5-278372 (JP, A) JP-A-5-137849 (JP, A) JP-A-6-134915 (JP, A) JP-A-6-8628 (JP, A) JP-A-60-162061 (JP, U) JP-A 63-91080 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B41M 5/28-5/34

Claims (2)

(57) [Scope of request for utility model registration] 1. A thermochromic concealing layer 4 for covering a first printed image 3 formed on the surface of a support 2 in a laminate for concealing different printed images due to a temperature change. A reversible thermochromic laminate comprising a metallic luster pigment layer 5 laminated on the layer 4 and a second printed image 6 provided on the metallic luster pigment layer 5. 2. The reversible thermochromic laminate according to claim 1, wherein the metallic luster pigment layer 5 is a layer in which a silver metallic luster pigment is fixedly dispersed in a transparent resin.