JPS63107585A - Thermal transfer medium changing its color due to temperature change - Google Patents

Abstract

PURPOSE:To enable recording of a transfer image having characteristics that the color changes due to remarkably favorable temperature change, by forming a transfer layer changing its color according to at least temperature change on a base film directly or through a releaser layer. CONSTITUTION:A transfer layer 3 changing its color due to at least temperature change is formed on a base film 1 directly or through a release layer 2. In this manner, a thermal transfer medium capable of recording transfer images, such as characters, illustrations, and maps, changing the color due to markedly favorable temperature change and changing its color due to temperature change is obtained. The transfer layer 3 changing its color due to temperature change is formed by coating on the base film 1 directly or through the releaser layer 2. As a coating material which forms the transfer layer changing its color due to temperature change and changes its color due to temperature change, for example, an ink or coating composition etc. containing a microcapsuled cholesteric liquid crystal material or temperature sensitive nematic material can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a thermal transfer medium that changes color due to temperature changes and is used in thermal transfer devices such as printers and facsimiles. More specifically, the present invention relates to a thermal transfer medium that changes color by being heated by some heat source after images such as characters, illustrations, maps, etc. are transferred and recorded using the thermal transfer device.

[Prior Art] Conventionally, a thermal transfer medium has been provided with a heat-melting ink layer that melts at a predetermined temperature on a base film having a thickness of, for example, 3 to 12 μm. To explain the recording operation of the medium, there is a thermal head in contact with the base film, and when the thermal head is driven according to the recording signal and that part generates heat, the heat-melting ink on the corresponding part of the base film melts. and is transferred to the receiving paper. A transfer image corresponding to the recording signal is formed on the transfer paper using this transfer ink, and it is possible to record on the transfer paper using paper passing through the paper. Since a mixture of pigments such as carbon fluff is used in the heat-melting ink layer, the transferred image formed on the surface of the transfer paper is limited to the color of the pigment used in the heat-melting ink layer. It was completely impossible to record transferred images that changed color due to changes in humidity.

[Purpose of IJJ] In view of the above-mentioned conventional problems, it is an object of the present invention to provide a heat-sensitive transfer medium capable of recording a transferred image having an extremely good property of changing color due to changes in temperature.

[Constitution of the invention, that is, the non-invention is a thermal transfer that changes color due to temperature change, characterized in that a transfer layer that changes color due to temperature change is formed on a base film directly or through a template agent layer. It's about the medium.

That is, in the thermal transfer medium of the present invention that changes color due to temperature changes, by using at least a transfer layer that changes color due to temperature changes in place of the heat-melting ink layer of conventional thermal transfer media, the color changes due to extremely favorable temperature changes. Characters with changing properties.

They completed a thermal transfer medium that changes color due to temperature changes, allowing the recording of transferred images such as illustrations and maps.

Namely book 9. rJI has a transfer layer (3) that changes color due to temperature changes, either directly or via a template agent layer (2), on the base film (1), which allows for very good color change due to temperature changes. Changing characters, illustrations,
The objective of this invention is to provide a heat-sensitive transfer medium that changes color due to temperature changes and is capable of recording transferred images such as maps.

As the base film (1) in the thermal transfer medium that changes color due to temperature changes in the present invention, any material can be used as long as it has sufficient self-retention properties, such as polyester, polyamide, polyamideimide, polyethylene,
Resins such as polypropylene, cellulose acetate, polycarbonate, polyvinyl chloride, and fluorine resins, film-like materials or sheet-like materials such as cellophane paper and glassine paper, and release paper or release films are used as appropriate. In particular, as the base film (1), should a film-like material of the above-mentioned resins be used with a thickness of about 2.5 to 12Q?
The manufacture of thermal transfer media that changes color due to temperature changes without wrinkles or cracks is preferable because it can be produced continuously in large quantities, and the invention previously filed by the present applicant (Japanese Patent Application No. 60-26)
0774), a thin film of an inorganic material, such as 5iO1SiOz, TiO2, ZnO181203, is applied to the opposite side of the plastic film to the side on which the thermal transfer layer is provided.
oxides such as, nitrides such as TiN, carbides such as Ti(:), carbon, AI, Ni.

6-1OOn3 of metals such as Cr, Ti, Ni-Cr alloy, etc.
It is also preferable to use a hot-stake resistant product with a thin film of about 100%.

In addition, if the base film (1) has poor releasability from the transfer layer (3) that changes color due to temperature changes or the protective resin coating layer (:ll), use paraffin wax, silicone, fluororesin, or surfactant. The release agent layer (2) may be formed by coating lτ1.

The transfer layer (3) that changes color due to temperature changes according to the present invention is formed by coating IHj on the base film (1) directly or via the release agent layer (2) by a conventional method. For example, an ink or coating composition containing microencapsulated cholesteric liquid crystal or temperature-sensitive nematic liquid crystal can be used as the paint that changes color due to temperature change constituting the transfer layer that changes color due to temperature change. In terms of JL, for example, one or more types of cholesteric liquid crystals and temperature-sensitive nematic liquid crystals can be arbitrarily blended [i. A liquid crystal composition is produced, and then the above liquid crystal is microencapsulated using a wall-forming substance such as gelatin and a normal microencapsulation method. If liquid crystal is required, conventional dyes, pigments, and vehicles for conventional ink or paint compositions, such as natural waxes such as spermaceti, beeswax, lanolin, carnauba wax, candelilla wax, and montan wax, paraffin wax,
Microcrystalline wax, oxidized wax, ester wax, synthetic wax such as low molecular weight polyethylene, higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, fromene acid, behenic acid, etc., higher alcohols such as stearyl alcohol, behenyl alcohol, etc. , esters such as sucrose fatty acid ester, sorbitan fatty acid ester, amides such as stearinamide and oleinamide, polyamide resin, polyester resin, epoxy resin, polyurethane resin, acrylic resin, vinyl chloride resin , cellulose resins, polyvinyl resins, petroleum resins, ethylene-vinyl copolymer resins, phenolic resins, styrene resins, natural rubber, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, and other elastomers; rosin and its derivatives,
Preferably used is a paint that changes color with temperature changes and is made of tackifier-2 fillers such as terpene resins and hydrogenated petroleum resins, plasticizers, antioxidants, etc. alone or in combination.

In this case, known cholesteric liquid crystals may be used, such as cholesteryl nonanoate, cholesteryl oleate, cholesteryl chloride, cholesteryl oleyl carbonate, cholesteryl benzoate, cholesteryl acedate, cholesteryl-3-beta amine, etc. It's coming. In addition, as the temperature-sensitive nematic liquid crystal, there are known ones such as para-azoxyaninsol, para-azoxyphenethole, a5-acyldene-valeraminophenyl acetate, paramethoxybenzylidene-varbutylanirane, para-ethoxybenzylidene -vararbutylaniline, etc. can be used.

In the above, wall-type R& substances include, in addition to the above-mentioned gelatin, shellac, gum arabic, rosin, rosin ester, ethyl cellulose, carboxymethyl cellulose, paraffin, trisdearin, polyvinyl alcohol, polyethylene, polypropylene, acrylic resin, vinyl resin, polyisobutyne, polybutadiene, epoxy resin, phenolic resin, polyurethane,
One or two kinds of inserts 1 made of polyester, polyamide, silicone, etc. can be used alone or in combination.

Examples of microencapsulation methods include coacervation methods, interfacial encapsulation methods, submerged coating methods, and phase separation methods from organic solvents.

It can be carried out by a conventional method such as an in-liquid drying method, an air suspension coating method, or a spray drive method.

In the liquid crystal ink or coating composition of the present invention, the formulation of microencapsulated liquid crystal - I'A is as follows:
"Vehicle 100f for ink or paint composition like two feet
It is preferable to mix the microencapsulated liquid crystal in a proportion of about 5 to 100 parts to i (parts by weight, the same applies hereinafter).

The thickness of the transfer layer (3), which changes color due to temperature changes, is approximately 0.5 to 100 μm, but the method for producing transfer foil that changes color due to temperature changes without wrinkles or cracks has become the standard. It is preferable from the point of view of mass production, and if it is thinner than 0.51, it has the property of sufficiently stable color change due to temperature change, and has high physical and chemical stability such as surface strength, acid resistance, alkali resistance, etc., and color change due to temperature change. If it is thicker than 100 gm, it will be difficult to transfer patterns such as delicate character designs, so it is not preferable for transferring patterns such as delicate character designs.

Formation of the liquid crystal ink composition coating layer as the transfer layer (3) that changes color due to temperature changes includes an organic solvent solution of the microencapsulated liquid crystal-containing ink or coating composition;
By applying an aqueous solution, etc. to a normal coating method such as roll coating, gravure coating, rehearsing coating, or spray coating? ! This is done by applying a cloth and drying (curing in the case of thermosetting resin, electron beam curable resin, ultraviolet curable resin, etc.).

In the thermal transfer medium of the present invention that changes color due to temperature changes, the transfer layer itself that changes color due to temperature changes has weak mechanical strength and is easily damaged by friction. Mold release agent layer (2)
A protective resin coating layer (31) may be provided in advance via a . There is no particular limit to the thickness of the protective resin coating, or it is usually 0.5
The amount is appropriately selected from the range of ~2 μl.

As the resin forming the protective resin coating layer (31), for example, any one of thermal 11T plastic resin, thermosetting resin, electron beam curable resin, and ultraviolet curable resin can be used.
For example, acrylic resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polycarbonate, nitrocellulose, cellulose acetate, urethane resin,
Urea resin, melamine resin, urea-melamine resin,
Epoxy resin, alkyd resin, amino alkyl 1
- type resins, rosin-modified maleic acid resins, etc. are preferably used alone or in mixtures.

The protective resin layer is formed by applying a resin organic solvent solution, aqueous solution, etc. to the above-mentioned maintenance coating to form a resin coating film using a conventional coating method such as roll coating method, gravure coating method, Sohas coating method, spray coating method, etc. This is done by coating the resin by a method and drying (curing in the case of thermosetting resin, electron beam curable resin, ultraviolet curable resin, etc.).

The protective resin layer may be colored with a colorant such as a dye or a pigment as long as it is transparent or translucent.

In the thermal transfer medium of the present invention that changes color due to temperature changes, the coating layer of the liquid crystal ink composition is coated with metals such as aluminum, soot, zinc, copper, silver, gold, nickel, chromium, titanium, etc. An alloy can be deposited to form a metal vapor layer (32). As a result, in the present invention, it is possible to simultaneously exhibit the color change due to temperature change of the liquid crystal and the reflection effect due to the metal vapor deposited film.

Furthermore, in the thermal transfer medium of the present invention that changes color due to temperature changes, ink or paint of, for example, black or dark blue is coated on the coating layer of the liquid crystal ink composition using a conventional method. A colored layer (32) of black, dark blue, etc. can be formed by a conventional printing method, coating method, etc. using a 1-compound. By doing this, the liquid crystal exhibits a color change due to its characteristic of selectively reflecting light of a specific wavelength and transmitting light of other wavelengths depending on a specific temperature, so the color change can be made even more vivid. It is.

In the thermal transfer medium of the present invention, which changes color due to temperature changes, in order to increase the mechanical strength of the transfer layer itself, which changes color due to temperature changes, to make it less susceptible to damage due to scratches, etc., the color changes due to temperature changes. Although it is possible to change the color of the paint that changes color due to temperature changes to form the transfer layer by making resin the main component, this tends to result in poor transfer rate and transfer strength to the receiving paper. , an adhesive layer (33) may be provided on the surface of the transfer layer that changes color due to temperature changes.

Examples of the adhesive layer (33) of the heat-sensitive transfer medium that changes color due to temperature changes in the present invention include natural waxes such as spermaceti wax, beeswax, lanolin, carnapax, candelilla wax, and montan wax, paraffin wax, microcrystalline wax, Oxidized wax, ester wax, synthetic wax such as low molecular weight polyethylene, lauric acid, myristic acid, palmitic acid, stearic acid,
Higher fatty acids such as fromenic acid and behenic acid, higher alcohols such as stearyl alcohol and behenyl alcohol, esters such as sucrose fatty acid ester, sorbitan fatty acid ester, amides such as stearinamide and oleinamide, polyamide resin, boroester resin, epoxy resin, polyurethane resin, acrylic resin,
Vinyl chloride resin, cellulose resin, polyvinyl resin, petroleum resin, ethylene-vinyl acetate copolymer resin, phenolic resin, styrene resin, natural rubber, styrene rubber, imprene rubber, chloroprene rubber, etc. Tackifier-1 fillers such as elastomers, rosin and its derivatives, terpene resins, hydrogenated petroleum resins,
Plasticizers, antioxidants, etc. may be used alone or in combination. As long as the adhesive layer is transparent or translucent, dyes that change color due to temperature changes or pigments that change color due to temperature changes may be added to the adhesive layer in order to enhance the effect of changing color due to temperature changes throughout the thermal transfer medium. The thickness of the VI adhesive layer (33) may be selected depending on the surface condition of the transfer paper, etc., and is usually 1 to 10.
It is selected from a range of about 1 μm and is relatively thin, about 1 in 1 to 2 μm, when the surface of a normal transfer paper is relatively smooth.

Next, unreleased IJII will be explained by giving examples.

Examples] Example 1 A liquid crystal composition consisting of 6 parts of cholesteryl butyrate, 16 parts of cholesteryl carbonate, and 28 parts of cholesteryl carbonate was produced, and then gelatin was used to produce a liquid crystal composition according to the coacervation method. A slurry with an e content of 30% (TunIll'%, hereinafter the same) was obtained by microcapsulating M.

Next, 50 parts of the above slurry, 50 parts of paraffin wax, 25 parts of carnauba wax, 15 parts of ester wax, and 10 parts of ethylene-vinyl acetate (combined resin) were mixed with a mixed solvent consisting of 60 parts of toluene and 20 parts of petroleum naphtha. A liquid crystal ink composition was prepared by thoroughly kneading the liquid crystal ink composition.9Then, this liquid crystal ink composition was coated on a polyethylene terephthalate film with a thickness of 6μ, and dried to a thickness of 5μ.
11) is a thermal transfer medium of the present invention that changes color due to temperature changes, by forming a transfer layer that changes color due to changes in temperature.

Example 2 A coating solution prepared by dissolving 20 parts of ester wax in a mixed solvent consisting of 60 parts of toluene and 20 parts of petroleum naphtha was applied onto a polyethylene terephthalate film with a thickness of 6 μm and dried to form a mold release agent with a thickness of 1 μm. Form a layer, and then apply a liquid crystal ink composition obtained by thoroughly kneading 50 parts of the same slurry used in Example 1 and 50 parts of a 30% polyacrylamide solution on the surface 4j, After drying, a transfer layer with a thickness of 2 and which changes color depending on temperature changes is formed, and on the surface of the transfer layer, 50 parts of paraffin wax, 25 parts of carnauba wax, 10 parts of ester wax, and ethylene-vinyl acetate are combined with a synthetic resin IO. The heat-sensitive transfer medium of the present invention, which changes color due to temperature changes, is prepared by applying a mixed adhesive consisting of 50% and 90% by hot-melt coach ink method and drying to form an adhesive layer having a thickness of 21%.

Example 3 50 parts of the same slurry used in Example 1, 50 parts of ester wax, and 50 parts of carnauba wax were thoroughly kneaded onto a polyethylene terephthalate film with a thickness of 12B! ) is coated with the liquid crystal ink composition 4j and dried to form a transfer layer that changes color due to temperature changes to a thickness of 31 parts, and then aluminum is deposited on that surface by vacuum evaporation to a thickness of 50 parts. 20 parts of paraffin wax, 5 parts of carnauba wax, 5 parts of ethylene-vinyl acetate resin, 60 parts of toluene, and 20 parts of turpentine oil. A coating solution prepared by dissolving 11i was applied and dried to form an adhesive layer with a thickness of 2 μm to obtain a thermal transfer medium of the present invention which changes color due to changes in temperature.

[Effect of Light 1] Thermal transfer printer Canon (Knee 425:l (Canon Co., Ltd. Printed with

(Text on the printed paper): Images such as pamphlets, illustrations, maps, etc. are well-transferred and recorded, and in addition,
It reversibly changes into various hues depending on temperature changes.

[Brief explanation of the drawing]

No. 11'A is a cross section 17I showing the basic structure of the thermal transfer medium that changes color due to temperature changes according to the wooden door invention, and No. 21A is another implementation of the thermal transfer medium that changes color due to temperature changes according to the present invention! FIG. (1) Two-base film (2): Release agent layer (31): Protective resin layer (3): Transfer layer that changes color due to temperature changes (:12)
: 24 metal layers or/and colored layers (3): Adhesive layer

Claims (1)

[Scope of Claims] 1. A heat-sensitive transfer medium that changes color due to temperature changes, characterized in that a transfer layer that changes color due to temperature changes is formed on a base film directly or via a release agent layer. 2. The thermal transfer medium that changes color due to temperature change according to claim 1, wherein the transfer layer that changes color due to temperature change is a liquid crystal ink composition coating layer. 3. Color changing due to temperature change as described in claim 1, in which a protective resin coating layer is interposed directly on the base film or between a release agent layer and a transfer layer that changes color due to temperature change. Thermal transfer medium. 4. Temperature change recited in claim 1, wherein an adhesive layer is successively formed on a transfer layer that changes color due to temperature change, either directly or through a release agent layer on the base film. A color-changing thermal transfer medium. 5. The transfer layer that changes color due to temperature changes is formed by sequentially forming at least a protective resin coating layer, a transfer layer that changes color due to temperature changes, and an adhesive layer on the base film directly or via a release agent layer. A thermal transfer medium that changes color due to temperature changes as claimed in claim 1.