JP2639523B2 - Thermal recording display - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermosensitive recording display which performs recording and erasing by utilizing a reversible change in transparency of a thermosensitive material depending on temperature.

2. Description of the Related Art As a heat-sensitive recording material capable of reversible recording and erasing, a heat-sensitive recording material in which a low-molecular organic material such as a higher alcohol or a higher fatty acid is dispersed in a resin such as polyester or polyamide on a support is provided, for example. Kaikai 54-119377, 55-
It is known in 154198 and the like. Recording with this type of recording material, that is, image formation and erasing, utilizes a change in transparency due to the temperature of the heat-sensitive layer.

However, when a layered colored material is disposed on the back surface of the recording material and used as a display, the illumination light overlaps depending on the viewing angle when the ratio of specular reflection on the surface is large, and as a result, the contrast decreases and the image is recognized as an image. It may not be possible.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermosensitive recording display capable of forming a high-contrast clear image by reducing the regular reflection of light on the surface.

The thermosensitive recording display of the present invention comprises a resin base material and an organic low-molecular substance dispersed in the resin base material as main components,
Provide or arrange a surface-roughened resin layer or film having a surface glossiness of 40% or less on one surface of a layered heat-sensitive member having a heat-sensitive material whose transparency reversibly changes depending on temperature, and on the other surface. A layered colored member is provided.

The recording principle of the display body of the present invention utilizes a change in the transparency of the heat-sensitive body depending on the temperature.
Susceptor in Figure 1 is in a white turbid opaque state at room temperature, for example T ₀ or less. When this is heated to a temperature between T _{1 and} T ₂ , it becomes transparent, and in this state, it remains transparent even if it is returned to room temperature of T ₀ or lower. Upon further heating to T ₃ or more temperature becomes translucent state intermediate between the maximum transparency and the maximum opacity. Next, when the temperature is lowered, the state returns to the original cloudy and opaque state without taking the transparent state again. When this opaque state is heated to a temperature between T _{0 and} T ₁ and then cooled to room temperature, that is, to a temperature equal to or lower than T _0, a state between transparent and opaque can be obtained. The above things became clear at room temperature also again heated to T ₃ or higher, by returning to room temperature, return to the cloudy opaque state again. That is, both opaque and transparent forms at room temperature and intermediate states thereof can be taken.

Thus for example, after heating the whole laminar thermal member having such a heat-sensitive material to a temperature between T ₁ ~T _2, T ₀ following clarified and cooled to room temperature, and then it partially with a thermal head or the like
If opacifying the part is heated to T ₃ temperature above the white image is formed. If a layered colored member is arranged on the back surface of the layered thermosensitive member having such a white image, this image can be recognized as a white image with the color of the colored member as a background.

Meanwhile, after heating the entire laminar thermal member to T ₃ or more temperature, turbidity back to room temperature T ₀ or less, after opacification, by heating to a temperature between partially T ₁ through T ₂ by a thermal head or the like If that part is made transparent, a transparent image is formed on a white surface. If a coloring member is arranged on the back surface of the layered heat-sensitive member having such a transparent image, this image can be recognized as an image of the color of the coloring member against a white background.

Recording and erasing of the above-described laminar thermal member can be repeated at least 10 about ⁴ times.

Here, the layered heat-sensitive member may be formed by forming the heat-sensitive body as a film on the support member or by forming the heat-sensitive body into a sheet without using the support member.

By the way, in the thermal display in which the coloring member is arranged on the back surface of the layered thermal member, the incident light is specularly reflected when the surface is close to the mirror surface as described above, and it is difficult to see the image because the illumination enters the eyes depending on the viewing angle. There is. Therefore, when the surface of the layered heat-sensitive member is roughened to have a glossiness of 40% or less as in the present invention, the regular reflection on the surface is reduced, and the image can be recognized from all angles. The glossiness here is JIS Z 8741 6
It is equivalent to 0 ° C specular gloss.

Next, each member and material used in the thermosensitive recording display of the present invention will be described.

The layered heat-sensitive member can be formed as a film on a support member or formed as a sheet by the following method, for example.

1) A method of dissolving a resin base material and an organic low-molecular substance in a solvent, applying this on a support member, and evaporating the solvent to form a film or sheet.

2) The resin base material is dissolved in a solvent in which only the resin base material is dissolved, and the organic low-molecular substance is pulverized or dispersed therein by various methods, applied to a support member, and the solvent is evaporated to form a film. Or a method of forming a sheet.

3) A method in which a resin base material and an organic low-molecular substance are heated and melted and mixed without using a solvent, and the resulting mixture is formed into a film or a sheet and cooled.

In this case, various solvents can be used depending on the type of the organic low-molecular substance and the resin base material.
Examples include organic solvents such as tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, chloroform, carbon tetrachloride, ethanol, toluene and benzene.

In the layered heat-sensitive member thus formed,
The organic low-molecular substance exists in a dispersed state as fine particles in the resin base material.

The resin base material used for the layered heat-sensitive member is a material that forms a film or sheet in which an organic low-molecular substance is uniformly dispersed and held, and that affects the transparency at the time of maximum transparency. For this reason, the resin base material is preferably a resin having good transparency, mechanical stability, and good film formability. Examples of such a resin include polyvinyl chloride; vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, and vinyl chloride-acrylate copolymer. And the like. Vinylidene chloride-based copolymers such as vinylidene chloride-vinyl chloride copolymers, vinylidene chloride-acrylonitrile copolymers; polyesters; polyamides; polyacrylates or polymethacrylates or acrylate-methacrylate copolymers, silicone resins, and the like. . These may be used alone or as a mixture of two or more.

On the other hand, the organic low-molecular substance may be appropriately selected in accordance with the selection of the temperatures T _{0 to} T ₃ in FIG.
° C, particularly preferably about 50 to 150 ° C. Such organic low molecular weight substances include alkanol; alkane diol; halogen alkanol or halogen alkane diol; alkylamine; alkane; alkene; alkyne; halogen alkane; halogen alkene, halogen alkyne; cycloalkane; cycloalkene; Unsaturated mono- or dicarboxylic acids or their esters, amides or ammonium salts; saturated or unsaturated halogen fatty acids or their esters, amides or ammonium salts; allylcarboxylic acids or their esters, amides or ammonium salts; Acids or their esters, amides or ammonium salts; thioalcohols;
Thiocarboxylic acids or their esters, amines, or ammonium salts; carboxylic acid esters of thioalcohols, and the like. These may be used alone or in combination of two or more. The carbon number of these compounds is 10 to 60, preferably 10 to 38, particularly preferably 10 to 30. The alcohol group in the ester may be saturated or unsaturated, and may be halogen-substituted. In any case, the organic low molecular weight substance contains at least one kind of oxygen, nitrogen, sulfur and halogen in the molecule, for example, -OH, -COOH, -CONH, -COO
_{R, -NH -, - NH 2} , -S -, - S-S -, - O-, is preferably a compound containing a halogen and the like.

More specifically, these compounds include lauric acid, dodecanoic acid, myristic acid, pentadecanoic acid, palmitic acid,
Stearic acid, behenic acid, nonadecanoic acid, arachiic acid,
Higher fatty acids such as oleic acid; esters of higher fatty acids such as methyl stearate, tetradecyl stearate, octadecyl stearate, octadecyl laurate, tetradecyl palmitate, docosyl behenate; C ₁₆ H ₃₃ -O-C ₁₆ H ₃₃ , C ₁₆ H ₃₃ -S-C ₁₆ H ₃₃ C ₁₈ H ₃₇ -S-C ₁₈ H ₃₇ , C ₁₂ H ₂₅ -S-C ₁₂ H ₂₅ C ₁₉ H ₃₉ -S-C ₁₉ H ₃₉ , C ₁₂ H _25- S-S-C ₁₂ H ₂₅ And ether or thioether.

The ratio between the low-molecular organic substance and the resin base material in the heat-sensitive layer is preferably about 1: 0.5-1: 16 by weight. When the ratio of the resin base material is less than this, it is difficult to form a film in which the organic low-molecular substance is held in the resin base material. Becomes difficult.

Further, the coloring member may be a member in which a colored layer is formed on a support member, or a member in which the support member itself is colored, and may be a film, a sheet, or a board.

The coloring member is a solution or a dispersion containing a coloring pigment or a dye and a resin binder if necessary, coated on a support member, for example, a layered heat-sensitive member, or paper, a plastic film, a glass plate, a metal plate, or It can be produced by kneading a coloring pigment or a dye with a binder and molding the mixture into a sheet. Here, known coloring pigments or dyes can be used. A commercially available product such as a color coated paper for printing can be used as it is as the coloring member.

As a method for roughening the surface of the thermal display as described above, the following method can be mentioned.

1) A resin solution or the like is applied to the surface, and the surface is roughened by adjusting drying conditions.

2) A dispersion containing a resin and a white or light-colored pigment is applied to the surface.

3) Glue the surface-roughened film or place it separately.

As the white or light-colored pigment used here, for example,
Silica, aluminum silicate, alumina, aluminum hydroxide, magnesium hydroxide, urea-formalin resin,
Inorganic and organic fine powder such as styrene resin.

Conventional resins are used as the resin, for example, polyvinyl alcohol, methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, polyacrylamide, polyacrylic acid, starch, gelatin, polystyrene, and vinyl chloride.
Vinyl acetate copolymer, polybutyl methacrylate, polyethylene, polypropylene, polystyrene, petroleum resin,
Acrylic resin, vinyl chloride resin, vinyl acetate resin, vinylidene chloride resin, polyvinyl alcohol, cellulose resin, polyamide, polyacetal, polycarbonate,
Water-soluble, organic solvent-soluble or aqueous emulsion-forming such as polyester, fluororesin, silicate resin, natural rubber, chloride rubber, butadiene rubber, olefin rubber, phenol resin, urea resin, melamine resin, epoxy resin, polyimide, etc. Can be used.

Hereinafter, the present invention will be described with reference to examples. "Department"
And “%” are based on weight.

Example 1 Behenic acid 5 parts Vinyl chloride-vinyl acetate copolymer (VYHH manufactured by UCC) 13 parts Tetrahydrofuran 82 parts A component composed of 82 parts was mixed and uniformly dissolved, and this was coated on one surface with a silane-based resin in advance. Roughened thickness 50
μ polyester film (30% gloss: Toray Industries, Inc.)
Coated with a wire bar and dried to a thickness of 15
A heat sensitive layer of μm was provided. Further, a black image paper was separately disposed on the surface of the film opposite to the surface roughening layer to obtain a thermosensitive recording display of the present invention.

Next, the entire display was heated to 65 ° C. and then cooled to room temperature, whereby the heat-sensitive layer film became transparent and the display turned black. When printing was performed on the surface of the heat-sensitive layer of the display with a thermal head, a clear white image was formed on a black background.

Next, after heating the entire heat-sensitive layer surface of the display to 65 ° C. and cooling to room temperature, the white image portion becomes transparent,
Then, printing and recording were performed by a thermal head in the same manner as described above, and a clear white image was formed on a black background.

Even if this operation was repeated 1000 times or more, an image could be formed similarly.

Even if the image thus formed was viewed from various angles, it was not difficult to see the image due to the regular reflection of the illumination light.

When this image was printed by a printer, a clear copy image was obtained.

Example 2 A similar solution for forming a heat-sensitive film was used except that a vinylidene chloride-acrylonitrile copolymer was used instead of the vinyl chloride-vinyl acetate copolymer in the heat-sensitive layer forming solution of Example 1; On the polyester film, a heat-sensitive layer having a thickness of 10 μm was formed in the same manner as in Example 1. This heat-sensitive layer was white.

A 21 μm thick fluororesin film (18% gloss: Aflex # 21N frosted type manufactured by Asahi Glass Co., Ltd.) is separately arranged on the surface of the heat-sensitive layer, and a black color is applied to the surface opposite to the fluororesin film. By arranging the coated paper as a separate body, a thermosensitive recording display of the present invention was obtained.

Next, when a print original was printed and recorded by a thermal head using this display in the same manner as in Example 1, a clear white image was obtained on a black background.

When this image was printed by a printer in the same manner as in Example 1, a clear copy image was obtained.

Even if the printed image formed as described above was viewed from various angles, it was not difficult to see the image due to the regular reflection of the illumination light.

Example 3 The same procedure was performed except that a polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) was used instead of the vinyl chloride-vinyl acetate copolymer in the heat-sensitive layer forming solution of Example 1, and stearic acid was used instead of behenic acid. Using a heat-sensitive layer forming solution,
A heat-sensitive layer having a thickness of 20 μm was formed on a polyester film having a thickness of 75 μm in the same manner as in Example 1. This heat-sensitive layer was white.

Then, on the film surface opposite to the heat-sensitive layer, a composition consisting of 2 parts of silica fine powder (oil absorption 65 ml / 100 g), 2 parts of vinylidene chloride resin, 80 parts of methyl ethyl ketone was dispersed using a ball mill for 24 hours using a wire bar. And a 2 μm-thick roughened resin layer (10% gloss) was provided.

Further, a black image paper was separately disposed on the surface opposite to the surface-roughened resin layer to obtain a thermosensitive recording display of the present invention.

Next, a print original was printed and recorded by a thermal head using this display in the same manner as in Example 1.
A clear white image was obtained on a black background.

When this image was printed by a printer in the same manner as in Example 1, a clear copy image was obtained.

It should be noted that even if the printed image formed as described above was viewed from various angles, it was not difficult to see the image due to the regular reflection of the illumination light.

Comparative Example 75 μm in thickness using the same heat-sensitive film forming solution as in Example 1.
A 15 μm-thick heat-sensitive layer was formed on the m-th polyester film in the same manner as in Example 1. This heat-sensitive layer was white. The gloss of the surface of the support of this film was 70%. Next, a black image paper was separately disposed on the heat-sensitive layer side of the film to obtain a thermographic display.

In this display, printing recording and heat erasing by the thermal head were performed in the same manner as in Example 1. However, when the formed image was viewed, the image could not be recognized at an angle at which the illumination light was regularly reflected. .

Effect The thermosensitive recording display of the present invention has a surface glossiness of 40% or less by the surface-roughened resin layer or film as described above, so that it is not affected by indoor illumination light, outdoor sunlight, etc. This has the advantage that a stable image can be recognized from various angles.

[Brief description of the drawings]

FIG. 1 is an explanatory view of the principle of recording and erasing of the thermosensitive recording display of the present invention.

Claims (1)

(57) [Claims] 1. A layered heat-sensitive member comprising a resin base material and a low-molecular organic substance dispersed in the resin base material as main components and having a heat-sensitive material whose transparency reversibly changes depending on temperature. A thermosensitive recording display comprising a surface-roughened resin layer or film having a surface glossiness of 40% or less provided or arranged on one side, and a layered colored member arranged on the other side.