JP2011068079A - Thermal transfer recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer recording medium which is low in observation light source dependency and can record a thermal transfer image favorable in color reproducibility. <P>SOLUTION: In the thermal transfer recording medium, on one surface of a support, at least a magenta thermal transfer layer and a cyanogen thermal transfer layer are installed repeatedly in order on the surface in the longitudinal direction of the support. Each of the magenta thermal transfer layer and the cyanogen thermal transfer layer contains at least two kinds of dyes. In the thermal transfer recording medium, a dye A which occupies 1-10 wt.% of all dyes contained in the magenta thermal transfer layer and a dye B which occupies 20-80 wt.% of all dyes contained in the cyanogen thermal transfer layer are the same dyes. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermal transfer recording medium having a thermal transfer layer for thermally transferring and recording characters or images on a thermal transfer member.

2. Description of the Related Art Conventionally, a sublimation type thermal transfer system or a melt type thermal transfer system has been adopted as a system for thermally transferring and recording characters or images on a thermal transfer medium.
The sublimation type thermal transfer system is a thermal transfer layer surface of a thermal transfer recording medium provided with a thermal transfer layer containing a dye, a binder, etc. on a support, and a thermal transfer member provided with a receiving layer for receiving the dye on another support. The receiving layer surface is superposed on each other, and the dye in the thermal transfer layer is sublimated by heating from the surface of the thermal transfer recording medium on which the thermal transfer layer is not provided by a thermal head or the like temperature-controlled by text or image information. By shifting to, a desired character or image is formed.
On the other hand, the melt-type thermal transfer system is a thermal transfer layer surface of a thermal transfer recording medium provided with a heat-meltable thermal transfer layer containing a pigment, wax or the like on a support, and a heat-transferable body provided with a receiving layer on another support. The surface of the receiving layer is superposed on each other and heated by a thermal head or the like, so that the thermal transfer layer is fused to the receiving layer and transferred to the receiving layer, thereby forming a desired character or image.
Of the thermal transfer systems described above, the sublimation thermal transfer system is widely used for monochrome prints such as letters and diagrams, and color prints such as digital camera images or computer graphics images.

  By the way, in the thermal transfer recording of the sublimation thermal transfer system, the dependency of the thermal transfer image printed on the thermal transfer body by the printer on the observation light source may be a problem. That is, there is a problem of color reproducibility that the color of an image recorded by thermal transfer changes greatly depending on the type of observation light source, which may be a serious drawback.

  As a technique for solving the problem of color reproducibility, a dye to be contained in a cyan thermal transfer layer is C.I. I. Solvent Blue 63 and C.I. I. A technology aimed at producing a thermal transfer sheet (thermal transfer recording medium) as Solvent Blue 36, giving good color density even when there is little thermal energy applied during printing, and realizing a very wide range of color reproduction (For example, refer to Patent Document 1).

JP-A-62-255189

  Various techniques have been proposed as techniques aiming at improving color reproducibility, including the technique disclosed in Patent Document 1 described above, and any of these techniques can be achieved by reducing the dependency on the observation light source. This is not an attempt to improve color reproducibility, and the problem that the color of the thermal transfer image changes greatly depending on the type of observation light source has not been solved.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in a thermal transfer recording medium, and to provide a thermal transfer recording medium capable of recording a thermal transfer image with low observation light source dependency and good color reproducibility.

  In view of the above-mentioned problems of the prior art, the present inventors have provided a thermal transfer recording medium in which at least a magenta thermal transfer layer and a cyan thermal transfer layer are repeatedly provided in a surface sequence in the longitudinal direction of the support on one side of the support. The present inventors have found that the above-mentioned problems can be achieved by mixing a specific amount of the dye contained in the cyan thermal transfer layer with the magenta thermal transfer layer, thereby completing the present invention.

  That is, the invention described in claim 1 is a thermal transfer recording medium in which at least a magenta thermal transfer layer and a cyan thermal transfer layer are repeatedly provided in the longitudinal direction of the support on one side of the support. Each of the thermal transfer layer and the cyan thermal transfer layer contains two or more dyes, and dye A occupying 1 to 10% by weight of the total dye contained in the magenta thermal transfer layer, and all of the cyan thermal transfer layer. The thermal transfer recording medium is characterized in that the dye B occupying 20 to 80% by weight of the dye is the same dye.

  In the thermal transfer recording medium according to claim 1, when the weight of the dye A is Am and the weight of the dye B is Ac, the ratio (Ac / Am) is 1-20. It is characterized by being.

  Furthermore, the invention described in claim 3 is the thermal transfer recording medium according to claim 1 or 2, wherein the dye A and the dye B are anthraquinone dyes or indoaniline dyes.

  The thermal transfer recording medium of the present invention is a thermal transfer recording medium in which at least a magenta thermal transfer layer and a cyan thermal transfer layer are repeatedly provided in one surface of the support in the longitudinal direction of the support, and the magenta thermal transfer layer. And the cyan thermal transfer layer each contain two or more dyes, the dye A occupying 1 to 10% by weight of the total dye contained in the magenta thermal transfer layer, and the total dye contained in the cyan thermal transfer layer. Since the dye B occupying 20 to 80% by weight is the same dye, thermal transfer recording with extremely low observation light source dependency and good color reproducibility is possible.

It is explanatory drawing which shows schematic cross-sectional structure of the thermal transfer recording medium of this invention.

  Hereinafter, the thermal transfer recording medium of the present invention will be described in more detail. As shown in the figure, the thermal transfer recording medium 1 has a magenta thermal transfer layer 3, a cyan thermal transfer layer 4, and a yellow thermal transfer layer 5 that are repeatedly provided in one surface of the support 2 in the longitudinal direction of the support 2. Is. In the figure, reference numeral 6 denotes a heat transferable protective layer for protecting a transfer image which is transferred onto a transfer image recorded on a thermal transfer member by a thermal transfer layer exhibiting each hue and located under the transfer image.

  As the support 2, a material equivalent to that conventionally used as a support substrate of a thermal transfer recording medium can be used, but those having excellent mechanical strength, flexibility, heat resistance and the like are preferable. Specific examples include plastic films made of polyethylene terephthalate, polyethylene naphthalate, polypropylene, cellophane, polycarbonate, polyvinyl chloride, polystyrene, polyimide, nylon, polyvinylidene chloride, and papers such as condenser paper and paraffin paper. Can do. Among these, a film made of polyethylene terephthalate is preferably used. Although the thickness of the support body 2 should just be about 2-25 micrometers, it is more preferable if it is about 2-12 micrometers.

In order to prevent such heat shrinkage of the support 2 due to heat from the thermal head and breakage due to friction with the thermal head, a surface provided with thermal transfer layers 3, 4, 5 and a protective layer 6, which will be described later, May be provided with a heat-resistant slipping layer on the opposite surface.

  Examples of the constituent material of the heat resistant slipping layer include cellulose resins, polyester resins, acrylic resins, vinyl resins, polyurethane resins, and the like. For the purpose of improving heat resistance, a crosslinking agent may be used together with these resins. Further, for the purpose of improving the lubricity, a lubricant such as silicone oil may be contained in the layer, or the above-mentioned resin modified with silicone may be used.

  Moreover, in order to improve the adhesiveness between a support body and this heat resistant slipping layer, you may make it provide an easily bonding layer on the support body 2, and provide a heat resistant slipping layer on it. Without providing the heat resistant slipping layer, the surface roughness of the surface of the support contacting the thermal head may be adjusted by various methods to improve the heat resistance and the slipperiness.

  The thermal transfer layers 3, 4, and 5 provided on such a support 2 transfer the dye contained therein to the thermal transfer body, or selectively transfer a part thereof to the thermal transfer body. It is a heat transferable layer mainly composed of a dye and a binder for recording a desired thermal transfer image by transferring.

  A conventionally well-known thing can be used as said dye. Examples of yellow dyes include Kayaset Yellow AG, Kayaset Yellow TDN, PYT52, Plast Yellow 8040, Holon Brilliant Yellow S6GLPI, and the like. Examples of magenta dyes include Kayaset Red B, Kayaset Red 130, Ceres Red 7B, Macrolex Red Violet R, C.I. I. Disperse thread 60 and the like can be mentioned. Examples of cyan dyes include Kayaset Blue 714, Ceres Blue GN, MS Blue 50, TSD-44, C.I. I. Solvent Blue 63, C.I. I. Solvent Blue 36 etc. can be mentioned. The dye used is not necessarily limited to these.

In the thermal transfer recording medium 1 of the present invention, each of the magenta thermal transfer layer 3 and the cyan thermal transfer layer 4 in the thermal transfer layers 3, 4 and 5 provided on one surface of the support 2 contains two or more dyes. Among the two or more dyes contained in the magenta thermal transfer layer 3, the dye A occupying 1 to 10% by weight of the total dye contained in the magenta thermal transfer layer 3 and two or more dyes contained in the cyan thermal transfer layer 4 Among the dyes, the same dye is used as the dye B occupying 20 to 80% by weight of the total dye contained in the cyan thermal transfer layer 4.
In this way, the dye used in a specific amount in the cyan thermal transfer layer 4 is mixed in a specific amount in the magenta thermal transfer layer 3 as well, thereby reducing the dependency on the observation light source of the transferred image thermally transferred and recorded by these thermal transfer layers. And good thermal transfer recording can be performed.

  Of the two or more dyes contained in the magenta dye layer, the dye occupying 1 to 10% by weight of the total dye is Dye A, and among the two or more dyes contained in the cyan thermal transfer layer, When the dye occupying 20 to 80% by weight of the dye is B, the ratio (Ac / Am) of the weight of the dye A (Am) to the weight of the dye B (Ac) is preferably 1 to 20. By making the ratio of the weight of the same dye contained in the magenta thermal transfer layer 3 and the cyan thermal transfer layer 4 in such a range, dependency on the observation light source can be further reduced.

  The dyes used for the dye A and the dye B may be the same dye, and the above-described known dyes can be used. Among these, when the dye A and the dye B are anthraquinone dyes or indoaniline dyes, the dependency on the observation light source can be further reduced.

On the other hand, as a binder used in combination with such a dye, heat resistance, dye such as polyvinyl acetal resin, polyvinyl butyral resin, polyester resin, phenoxy resin, styrene-acrylonitrile copolymer resin, ethyl cellulose, hydroxyethyl cellulose, polycarbonate, etc. Examples thereof include resins having excellent migration properties.

  The glass transition temperature of such a binder is preferably 50 ° C. or higher. A glass transition temperature of less than 50 ° C. is not preferred because the thermal transfer layer is likely to be fused to the thermal transfer body during thermal transfer, and problems with storage stability of the thermal transfer recording medium are likely to occur. Furthermore, the ratio of the dye and the binder contained in the thermal transfer layer is preferably about 100: 50 to 100: 300.

  In this thermal transfer layer, a crosslinking agent may be used together with the above-described resin for the purpose of improving heat resistance. By using a cross-linking agent in combination, the heat resistance is improved, and deformation of the thermal transfer recording medium due to heat can be prevented. Examples of the crosslinking agent include polyisocyanates, which may be used in combination with acrylic, urethane, and polyester polyol resins, cellulose resins, acetal resins, and the like.

  Moreover, you may make it contain a mold release agent in a thermal transfer layer. When a release agent is contained, the release property on the surface of the thermal transfer layer is further improved. As the release agent, for example, various silicone-based, fluorine-based and phosphate ester-based oils and surfactants, and various fillers such as metal oxides and silica can be used. Among these, it is preferable to use silicone oil.

  The film thickness of the thermal transfer layers 3, 4 and 5 may be about 0.2 to 5.0 μm, more preferably about 0.4 to 3.0 μm. When the thickness is less than 0.2 μm, it is difficult to obtain sufficient color development sensitivity, and when it exceeds 5.0 μm, the color development sensitivity tends to deteriorate.

  The thermal transfer layer may contain fine particles. Examples of such fine particles include inorganic fine particles such as talc, clay, kaolin, magnesium oxide, magnesium hydroxide, and calcium carbonate, and organic fine particles such as polyethylene particles, polypropylene particles, polystyrene particles, and silicone particles. .

  Moreover, in order to improve the adhesiveness of a thermal transfer layer and a support body, you may make it provide an easily bonding layer as an intermediate | middle layer. In addition, a surfactant, an antiblocking agent, an antioxidant, an ultraviolet absorber, an antistatic agent, etc. may be added to the thermal transfer layer as necessary, and further, antiblocking, antioxidant, ultraviolet rays are added. You may make it laminate | stack the layer which has functions, such as absorption and antistatic.

  The thermal transfer layers 3, 4, and 5 having such a configuration are applied on the support 2 by a wet coating method such as bar coating, blade coating, air knife coating, gravure coating, roll coating, etc. Thereafter, it may be formed by drying.

  A thermal transfer body for recording a desired transfer image on the thermal transfer recording medium of the present invention having the above-described configuration is one in which at least a receiving layer is provided on a support. As the support, those equivalent to those used as the support base of conventional thermal transfer recording media can be used, but those having excellent mechanical strength, flexibility, heat resistance and the like are preferable. Specifically, polyester films such as polyethylene terephthalate and polyethylene naphthalate, plastic films made of polyethylene, polyvinyl chloride, polycarbonate, polyester, polysulfane, polyimide, polyvinyl alcohol, aromatic polyamide, aramid, Examples thereof include paper base materials such as coated paper and synthetic paper. Although there is no limitation in particular in the thickness of such a support body, generally it should just be about 25-250 micrometers. If it is about 75-200 micrometers, it is more preferable.

  In addition, as a constituent material of the receiving layer, when the thermal transfer layer of the thermal transfer recording medium contains a sublimation dye, for example, a butyral resin having a dyeing property to the sublimation dye, polyethylene, polyurethane, Polypropylene, polyvinyl chloride, polybutadiene, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, polyamide, polyester, polycaprolactone, polyvinyl acetal, epoxy, or modified resins and blends thereof, etc. These thermoplastic resins and their cross-linked products can be used. These may be used alone or in combination of two or more. When the film thickness of the receiving layer is too thin, the reflection density of the image transferred and recorded decreases, and it becomes difficult to form a sufficient image. On the other hand, if it is too thick, color bleeding or the like tends to occur, and image quality tends to deteriorate. Therefore, the film thickness is generally about 1 to 30 μm, preferably about 3 to 10 μm.

  In the receiving layer mainly composed of the above-described constituent materials, various release agents are preferably contained for the purpose of preventing thermal fusion to the heat-transferred member during image formation. As such a release agent, a known release agent can be appropriately selected and used. For example, various silicone-based, fluorine-based and phosphate-based oils and surfactants, and various fillers such as metal oxide and silica can be used. Among these, it is preferable to use silicone oil. Moreover, although the addition amount changes with structural conditions of a receiving layer, generally it is preferable to mix | blend in the ratio of about 1 to 30 weight%.

  On the other hand, as described above, the thermal transferable protective layer 6 constituting the thermal transfer recording medium is a layer for protecting the transfer image recorded on the thermal transfer body by the thermal transfer layers 3, 4, and 5 exhibiting each hue. is there. The protective layer 6 is peeled off from the thermal transfer recording medium side by a thermal transfer method and transferred onto the thermal transfer body, and has a function of protecting a transfer image located below the thermal transfer body. Need to be.

  This protective layer may have a peelable single layer structure having a protective function, or a laminated structure in which an adhesive layer is provided on the surface to improve the adhesion to the surface of the thermal transfer body. It may be. Moreover, the thing of the structure by which the release layer was provided between the support bodies may be sufficient so that it can transfer easily from a support body.

  The release layer described above is provided in order to adjust the degree of peeling of the protective layer from the support side within a predetermined range and ensure stable peelability from the support. It is not always necessary if it is in an appropriate range. The constituent material of the release layer is not particularly limited, and examples thereof include water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, and sodium alginate, chlorinated rubber, cyclized rubber, and the like. Natural rubber derivatives, waxes such as natural wax, synthetic wax, cellulose derivatives such as nitrocellulose, cellulose, cellulose acetate propionate, acrylic, polyurethane, polyamide, polyimide, polyacetal, chlorinated polyolefin, Examples thereof include thermoplastic resins such as vinyl chloride-vinyl acetate copolymer, thermosetting resins such as melamine, epoxy, polyurethane, and silicone.

On the other hand, the peelable protective layer having a protective function is mainly composed of a binder and a functional additive that imparts an ultraviolet absorber, release property, slipperiness, etc., and has a thickness of about 0.3 to 3 μm. preferable. Examples of the binder constituting the protective layer include styrene resins such as polystyrene and poly α-methylstyrene, acrylic resins such as polymethyl methacrylate and polyethyl acrylate, polyvinyl chloride, polyvinyl acetate, and vinyl chloride. Vinyl acetate copolymers, vinyl resins such as polyvinyl butyral and polyvinyl acetal, polyester resins, polyamide resins, epoxy resins, polyurethane resins, petroleum resins, ionomers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers Synthetic resins such as nitrocellulose, ethyl cellulose, cellulose acetate propionate, etc., rosin, rosin-modified maleic acid resin, ester gum, polyisobutylene rubber, butyl rubber, styrene-butadiene rubber, butadiene - acrylonitrile rubber, derivatives of natural resins and synthetic rubber such as polychlorinated olefins, carnauba wax, waxes such as paraffin wax. Among these, acrylic resins, polyester resins, cellulose derivatives, and epoxy resins are preferable.

  And as a ultraviolet absorber contained in a protective layer, things, such as a benzophenone series, a benzotriazole series, a benzoate series, and a triazine series, are mentioned. More specifically, examples of the benzotriazole ultraviolet absorber include 2- (2H-benzotriazol-2-yl) -p-cresol and 2- (2H-benzotriazol-2-yl) -4-6-bis. (1-methyl-1-phenylethyl) phenol, 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, 2- (2H-benzotriazole -Yl) -4,6-di-tert-pentylphenol, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol and the like, and mixtures thereof, Examples include modified products, polymers, and derivatives. These may be used alone or in combination. Examples of triazine ultraviolet absorbers include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, 2- [4-[( 2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[(2- Hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4dimethylphenyl) -1,3,5-triazine, 2,4-bis (2,4-dimethyl) Phenyl) -6- (2-hydroxy-4-iso-octyloxyphenyl) -s-triazine and the like, mixtures thereof, modified products, polymers, derivatives and the like. These may be used alone or in combination.

  It is preferable to add the said ultraviolet absorber in the ratio of about 1-20 weight part with respect to 100 weight part of binders. When the addition amount is less than 1 part by weight, the ultraviolet absorbing ability may not be fully exhibited. On the other hand, if it is added in excess of 20 parts by weight, bleeding out to the surface of the printed material is likely to occur, and the possibility of deteriorating the quality of the transferred image increases.

  In addition, as functional additives to be included in the protective layer, silicone oils such as straight silicone and modified silicone, surfactants having fluoroalkyl groups or perfluoroalkyl groups, release agents represented by phosphate esters, Examples thereof include waxes such as carnauba wax, paraffin wax, polyethylene wax, and rice wax, and slip agents represented by organic or inorganic fillers. In addition, if necessary, light stabilizers such as hindered amines and Ni chelates, heat stabilizers such as hindered phenols, sulfurs and fertilizer resins, flame retardants such as aluminum hydroxide and magnesium hydroxide, phenols , Sulfur-based and phosphorus-based antioxidants, anti-blocking agents, catalyst accelerators, colorants in a range that maintains transparency, light scattering agents for translucency, gloss adjusting agents, fluorescent whitening agents, An antistatic agent or the like may be added.

On the other hand, as a binder constituting the above-mentioned adhesive layer, polystyrene, poly is a styrene resin such as α-methylstyrene, an acrylic resin such as polymethyl methacrylate and polyethyl acrylate, polyvinyl chloride, polyvinyl acetate, Vinyl chloride-vinyl acetate copolymer, polyvinyl resins such as polyvinyl butyral, polyvinyl acetal, polyester resin, polyamide resin, epoxy resin, polyurethane resin, petroleum resin, ionomer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester Synthetic resins such as copolymers, cellulose derivatives such as nitrocellulose, ethyl cellulose, cellulose acetate propionate, rosin, rosin-modified maleic resin, ester gum, polyisobutylene rubber, butyl rubber, styrene-butadiene rubber, Tajien - acrylonitrile rubber, derivatives of natural resins and synthetic rubber such as polychlorinated olefins, carnauba wax, waxes such as paraffin wax. In particular, acrylic resins and cellulose derivatives are preferable.

  In the adhesive layer made of such a constituent material, silicone oil, surfactant, release agent, wax, slip agent typified by organic or inorganic filler, ultraviolet absorber, light stability, if necessary An agent, a heat stabilizer, a flame retardant, an antioxidant, an antiblocking agent, a catalyst accelerator, a colorant, a light scattering agent, a gloss adjusting agent, a fluorescent whitening agent, an antistatic agent, and the like can be added.

  EXAMPLES Hereinafter, although an Example is described in detail, this invention is not limited to these Examples.

<Example 1>
First, a yellow thermal transfer layer forming ink, a magenta thermal transfer layer forming ink, and a cyan thermal transfer layer forming ink having the following compositions were prepared. Subsequently, a thin film made of each of the above inks was applied to the surface of a 4.5 μm thick polyethylene terephthalate film having a heat resistant slip treatment on the back surface, and then dried, and the dried film thickness was 1.0 μm. A thermal transfer recording medium according to Example 1 of the present invention was obtained by providing a thermal transfer layer, a magenta thermal transfer layer, and a cyan thermal transfer layer in the surface order.

[Yellow thermal transfer layer forming ink]
・ C. I. Solvent Yellow 93 3.5 parts C.I. I. Solvent Yellow 16 1.5 parts, polyvinyl acetal resin (Denka Butyral, manufactured by Denki Kagaku Kogyo Co., Ltd.) 5 parts, methyl ethyl ketone 60 parts, toluene 30 parts [ink for forming magenta thermal transfer layer]
・ C. I. Disper Thread 60 4.95 parts C.I. I. Solvent Blue 63 0.05 part ・ Polyvinyl acetal resin (Denka Butyral, manufactured by Denki Kagaku Kogyo Co., Ltd.) 5 parts ・ Methyl ethyl ketone 60 parts ・ Toluene 30 parts [Ink for forming cyan heat transfer layer]
・ C. I. Solvent Blue 63 1 part C.I. I. Solvent Blue 36 4 parts ・ Polyvinyl acetal resin (Denka Butyral manufactured by Denki Kagaku Kogyo Co., Ltd.) 5 parts ・ Methyl ethyl ketone 60 parts ・ Toluene 30 parts

Next, a laminate having a laminate structure of a foamed polypropylene film (thickness: 50 μm) / adhesive resin layer / coated paper (coating amount: 108 g / m ² ) / adhesive resin layer / foamed polypropylene film (thickness: 50 μm) as a base sheet. Using a sheet, a receiving layer forming ink having the following composition was applied to one side of the sheet so that the film thickness after drying was 4 μm, and then dried, followed by aging at 45 ° C. for 1 week, A thermal transfer member with a receiving layer was obtained.

[Receptive layer forming ink]
・ Vinyl chloride-vinyl acetate copolymer (manufactured by Nissin Chemical Industry Co., Ltd., Solvein A) 50 parts ・ Silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KF393) 2 parts ・ Methyl ethyl ketone 25 parts ・ Toluene 25 parts

<Example 2>
Among the magenta thermal transfer layer forming inks, C.I. I. 4.5 parts of disperse thread 60, C.I. I. A thermal transfer recording medium according to Example 2 was obtained in the same manner as Example 1 except that 0.5 parts of Solvent Blue 63 was used.

<Example 3>
Among the magenta thermal transfer layer forming inks, C.I. I. 4.8 parts of disperse thread 60, C.I. I. Solvent Blue 63 is 0.2 part, and among the cyan thermal transfer layer forming inks, C.I. I. 4 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Example 3 was obtained in the same manner as Example 1 except that 1 part of Solvent Blue 36 was used.

<Example 4>
Among the magenta thermal transfer layer forming inks, C.I. I. 4.5 parts of disperse thread 60, C.I. I. Solvent Blue 63 is 0.5 part, and among the cyan thermal transfer layer forming inks, C.I. I. 4 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Example 4 was obtained in the same manner as in Example 1 except that 1 part of Solvent Blue 36 was used.

<Example 5>
Among the magenta thermal transfer forming inks, C.I. I. 4.9 parts of disperse thread 60, C.I. I. Solvent Blue 63 is 0.1 part. Among the cyan thermal transfer layer forming inks, C.I. I. 4 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Example 5 was obtained in the same manner as Example 1 except that 1 part of Solvent Blue 36 was used.

<Comparative Example 1>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 is 4.975 parts, C.I. I. A thermal transfer recording medium according to Comparative Example 1 was obtained in the same manner as Example 1 except that 0.025 part of Solvent Blue 63 was used.

<Comparative Example 2>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 (4.25 parts), C.I. I. A thermal transfer recording medium according to Comparative Example 2 was obtained in the same manner as in Example 1 except that 0.75 parts of Solvent Blue 63 was used.

<Comparative Example 3>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 is 4.975 parts, C.I. I. The solvent blue 63 is 0.025 part, and among the cyan thermal transfer layer forming inks, C.I. I. 4 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Comparative Example 3 was obtained in the same manner as in Example 1 except that 1 part of Solvent Blue 36 was used.

<Comparative example 4>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 (4.25 parts), C.I. I. 0.75 parts of Solvent Blue 63, and among the cyan thermal transfer layer forming inks, C.I. I. 4 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Comparative Example 4 was obtained in the same manner as in Example 1 except that 1 part of Solvent Blue 36 was used.

<Comparative Example 5>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 is 4.98 parts, C.I. I. Solvent Blue 63 is 0.02 part, and among the cyan thermal transfer layer forming inks, C.I. I. 0.5 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Comparative Example 5 was obtained in the same manner as in Example 1 except that 4.5 parts of Solvent Blue 36 was used.

<Comparative Example 6>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 is 4.75 parts, C.I. I. Solvent Blue 63 is 0.25 part, and among the cyan thermal transfer layer forming inks, C.I. I. 0.5 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Comparative Example 6 was obtained in the same manner as in Example 1 except that 4.5 parts of Solvent Blue 36 was used.

<Comparative Example 7>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 (4.25 parts), C.I. I. 0.75 parts of Solvent Blue 63, and among the cyan thermal transfer layer forming inks, C.I. I. 0.5 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Comparative Example 7 was obtained in the same manner as in Example 1 except that 4.5 parts of Solvent Blue 36 was used.

<Comparative Example 8>
Among the magenta thermal transfer layer ink compositions, C.I. I. Disperse thread 60 is 4.975 parts, C.I. I. The solvent blue 63 was 0.025 part, and among the ink compositions for the cyan thermal transfer layer, C.I. I. 4.5 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Comparative Example 8 was obtained in the same manner as in Example 1 except that 0.5 parts of Solvent Blue 36 was used.

<Comparative Example 9>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 is 4.85 parts, C.I. I. Solvent Blue 63 is 0.15 part, and among the cyan thermal transfer layer forming inks, C.I. I. 4.5 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Comparative Example 9 was obtained in the same manner as in Example 1 except that 0.5 parts of Solvent Blue 36 was used.

<Comparative Example 10>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 is 4.75 parts, C.I. I. Solvent Blue 63 is 0.25 part, and among the cyan thermal transfer layer forming inks, C.I. I. 4.5 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Comparative Example 10 was obtained in the same manner as in Example 1 except that 0.5 parts of Solvent Blue 36 was used.

<Comparative Example 11>
Among the magenta thermal transfer layer forming inks, C.I. I. Disperse thread 60 (4.25 parts), C.I. I. 0.75 parts of Solvent Blue 63, and among the cyan thermal transfer layer forming inks, C.I. I. 4.5 parts of Solvent Blue 63, C.I. I. A thermal transfer recording medium according to Comparative Example 11 was obtained in the same manner as in Example 1 except that 0.5 parts of Solvent Blue 36 was used.

  Next, the thermal transfer layer surface of each obtained thermal transfer recording medium and the receiving layer surface of the thermal transfer member were overlapped, and the dye was transferred using a thermal head to print each color solid pattern image on the receiving layer of the thermal transfer member.

  And the following evaluation was performed with respect to the obtained transfer image.

[Evaluation of image]
The observation light source dependency of the obtained image is measured by L * a * b * while irradiating the D65 light source and F11 light source of X-rite 528 densitometer (manufactured by X-rite). ○, a slightly larger one was evaluated as △, and a larger one was evaluated as ×. The results are shown in Table 1.

  As shown in Table 1, it was found that the thermal transfer recording medium of the present invention has very little dependence on the observation light source of an image printed using it. In particular, in the magenta solid pattern, the greatest effect can be obtained. When a person image or a background image is actually printed using the thermal transfer recording media according to Examples 1 to 5, the dependency on the observation light source is reduced. It could be confirmed.

  In contrast, the thermal transfer recording media according to Comparative Examples 1 and 3 include C.I. contained in the magenta thermal transfer layer. I. Since Solvent Blue 63 was less than 1% and (Ac / Am) was greater than 20, it was confirmed that the printed image has a large dependency on the observation light source. The thermal transfer recording media according to Comparative Examples 2 and 4 include C.I. I. Since Solvent Blue 63 is larger than 10%, it has been confirmed that the dependency of the printed image on the observation light source is slightly increased. In addition, the thermal transfer recording media according to Comparative Examples 5 and 8 are C.I. I. Solvent Blue 63 is less than 1% and C.I. I. Since Solvent Blue 63 was less than 20% or greater than 80% and (Ac / Am) was greater than 20, it was confirmed that the printed image has a large dependency on the observation light source. Further, the thermal transfer recording media according to Comparative Examples 6 and 10 have C.I. I. Since Solvent Blue 63 was less than 20% or greater than 80%, it was confirmed that the dependency of the printed image on the observation light source was slightly increased. In addition, the thermal transfer recording medium according to Comparative Example 7 includes C.I. I. Solvent Blue 63 is greater than 10% and C.I. I. Since Solvent Blue 63 was less than 20% and (Ac / Am) was smaller than 1, it was confirmed that the printed image has a large dependency on the observation light source. The thermal transfer recording medium according to Comparative Example 9 has a C.I. I. Since Solvent Blue 63 is larger than 80% and (Ac / Am) is larger than 20, it was confirmed that the printed image has a large dependency on the observation light source. The thermal transfer recording medium according to Comparative Example 11 includes C.I. I. Solvent Blue 63 is greater than 10% and C.I. I. Since Solvent Blue 63 was larger than 80%, it was confirmed that the dependency of the printed image on the observation light source was increased.

  The thermal transfer recording medium of the present invention is widely employed as a recording medium used for monochrome printing such as characters and diagrams, and color printing such as digital camera images or computer graphics images.

DESCRIPTION OF SYMBOLS 1 ... Thermal transfer recording medium 2 ... Support body 3 ... Magenta thermal transfer layer 4 ... Cyan thermal transfer layer 5 ... Yellow thermal transfer layer 6 ... Protective layer

Claims (3)

  A thermal transfer recording medium in which at least a magenta thermal transfer layer and a cyan thermal transfer layer are repeatedly provided in a surface sequence in the longitudinal direction of the support on one side of the support, each of the magenta thermal transfer layer and the cyan thermal transfer layer being 2 Dye A containing at least one kind of dye and occupying 1 to 10% by weight of the total dye contained in the magenta thermal transfer layer, and occupying 20 to 80% by weight of the total dye contained in the cyan thermal transfer layer A thermal transfer recording medium, wherein B is the same dye.   2. The thermal transfer recording medium according to claim 1, wherein the ratio (Ac / Am) is 1 to 20 where the weight of the dye A is Am and the weight of the dye B is Ac.   The thermal transfer recording medium according to claim 1 or 2, wherein the dye A and the dye B are anthraquinone dyes or indoaniline dyes.

Images