JP5233736B2 - Method for manufacturing thermal transfer recording medium and thermal transfer recording medium - Google Patents

Description

  The present invention relates to a method for producing a thermal transfer recording medium and a thermal transfer recording medium, and more particularly, to a thermal transfer recording medium that can be satisfactorily applied with little unevenness when an ink having a wide viscosity range is applied on a base film by gravure printing. The present invention relates to a manufacturing method and a thermal transfer recording medium manufactured thereby.

  Conventionally, a method of forming a coating film on a substrate by gravure printing has been widely used in the production process of a thermal transfer recording medium. Specifically, when a thermal transfer layer such as a yellow layer, a magenta layer, or a cyan layer is formed on a base film, each color ink is transferred in a surface sequence on the base using a gravure plate, and yellow, magenta A solid pattern of cyan is formed. Generally, in the transfer method using a gravure plate, ink is brought into contact with the surface of the gravure plate, the ink is filled in the recess (cell) on the surface of the gravure plate, and then the excess ink is removed by a doctor blade and conveyed. The substrate film to be pressed is pressed against the gravure plate from the back side by an impression roll, and the ink held in the cells is transferred to the substrate.

  Although the ink transfer rate varies depending on the printing conditions, the surface shape of the plate, etc., it is said to be 35 to 65%, and the ink filled in the cell hardly transfers onto the substrate. As a result, immediately after the ink adheres to the base material, when the base film is transported without completely separating the ink transferred onto the base material and the ink remaining in the cell, it is streaked in the flow direction of the solid pattern. Cause unevenness. When an image is printed using the thermal transfer layer in which the unevenness occurs, the unevenness is transferred to the image surface after printing, and a clear image cannot be obtained. In addition, a difference in film thickness occurs between the starting end of the coating and the central portion of the coating, and when the obtained thermal transfer recording medium is processed into a roll, it cannot be wound evenly, resulting in improved running performance in the printer. Problems arise.

  In order to solve such a problem, several methods have been proposed. For example, in Patent Document 1, the ink transfer amount of 0.5 to 5 mm width at the printing start portion and both side end portions of the pattern printed by color is in the range of 90 to 5% compared to the amount of the regular portion. It has been proposed that printing unevenness does not cause printing unevenness that starts from the end portion, and prevents printing density unevenness seen when this is used as a thermal transfer sheet.

JP-A-8-142527

  However, when the coating is performed for a long time by the method proposed in Patent Document 1, a so-called semi-dried product of ink is considered to be caused by a cell having a volume smaller than the volume of the printed portion of the regular transfer layer. The phenomenon of plate clogging occurred, and streaky irregularities became prominent in the flow direction of the solid pattern. Further, it was found that the ink clogging of the cells and the stripe-like unevenness caused thereby tend to be severe when a high viscosity ink is used, and the above method is not suitable when a high viscosity ink is applied.

In view of the above problems, the present invention eliminates streaky irregularities and film thickness irregularities in the thermal transfer layer even when inks of various viscosities are applied, from low viscosity inks applicable to gravure printing to high viscosity inks. It aims at providing a thermal transfer layer on a base film without generating.

  The present inventor has found that the above problem can be solved by specifying the shape of the solid pattern of the thermal transfer layer, and has completed the present invention.

That is, the invention according to claim 1 is provided with one or more thermal transfer layers provided on one surface of a continuously running base film by applying and drying a thermal transfer layer coating liquid by gravure printing. In the method for producing a thermal transfer recording medium,
At least one thermal transfer layer is composed of two regions a and b in order from the running direction,
The length of the region a in the traveling direction is 1 to 7 mm,
A method for producing a thermal transfer recording medium, characterized in that a thermal transfer layer coating liquid is applied and dried at a distance of 0.5 to 2 mm in the running direction between the area a and the area b.

  The invention according to claim 2 is characterized in that the application amount per unit area of the region a is 5 to 150% with respect to the application amount per unit area of the region b. 1. A method for producing a thermal transfer recording medium according to 1.

The invention according to claim 3 is a thermal transfer recording medium comprising one or more thermal transfer layers on one surface of a base film,
At least one thermal transfer layer is composed of two regions a and b in order from the running direction,
The length of the area a in the running direction is 1 to 7 mm, and an interval of 0.5 to 2 mm is provided in the running direction between the area a and the area b. It is.

  The invention described in claim 4 is characterized in that the application amount per unit area of the region a is 5 to 150% with respect to the application amount per unit area of the region b. 3. The thermal transfer recording medium according to 3.

  First, the invention described in claim 1 shows that even when inks of various viscosities are applied from low viscosity ink to high viscosity ink applicable to gravure printing, streaky unevenness and film thickness unevenness are applied to the thermal transfer layer. There was an effect that did not occur.

  Further, the invention described in claim 2 limits the application amount per unit area of the region a and the region b described in claim 1 to a specific range, thereby further causing streaky unevenness and film thickness unevenness in the thermal transfer layer. There was an effect that did not occur.

  Further, the invention according to claim 3 can obtain a clear image without unevenness on the screen after printing, and at the same time, when it is processed into a roll and printed, it can be wound evenly, This has the effect of stabilizing the running performance.

  In the invention according to claim 4, when the application amount per unit area of the region a and the region b according to claim 3 is limited to a specific range, a clear image without unevenness can be obtained. At the same time, the running performance in the printer can be further stabilized.

It is a side surface schematic diagram of the manufacturing apparatus of the thermal transfer recording medium of this invention. 1 is a schematic top view of an embodiment of a thermal transfer recording medium of the present invention. 1 is a schematic top view of an embodiment of a thermal transfer recording medium of the present invention.

  Hereinafter, the present invention will be described in more detail. FIG. 1 shows an example of a thermal transfer recording medium manufacturing apparatus according to the present invention. The thermal transfer layer coating solution filled in the ink pan (8) is brought into contact with the gravure plate (7) to fill the cells on the surface of the gravure plate with the thermal transfer layer coating solution. Thereafter, the substrate film (5) to be conveyed is pressed against the gravure plate (7) from the back side by the impression roll (6), and the coating liquid held in the cell is transferred to the substrate, whereby the solid pattern of the thermal transfer layer is changed. Form. In the present invention, as shown in FIG. 1, a thermal transfer layer coating solution is applied to form a thermal transfer layer (2) composed of a region a (4) and a region b (3).

  FIG. 2 shows an example of the thermal transfer recording medium of the present invention. The thermal transfer recording medium of the present invention comprises at least a base film (5) and a thermal transfer layer (2). Further, the thermal transfer layer (2) is composed of a region a (4) and a region b (3).

  The length of the region a and the region b in the traveling direction of the region a is 1 to 7 mm, and it is preferable to provide an interval of 0.5 to 2 mm in the traveling direction between the region a and the region b. By forming the solid pattern of the thermal transfer layer within the above length range, streaky unevenness and film thickness unevenness generated in the pattern surface can be suppressed.

  In FIG. 2, solid patterns having the same width direction are shown, but the width directions do not necessarily have to be the same. If a solid pattern is formed in the above range, it may not be the same in the width direction.

  FIG. 3 is an example of a thermal transfer recording medium when a plurality of thermal transfer layers are provided on a base film. The three thermal transfer layers in FIG. 3 are a yellow layer, a magenta layer, and a cyan layer, and each layer forms the solid pattern of the present invention. The solid pattern of the present invention is formed for one or more of the thermal transfer layers provided on the base film. Further, in the thermal transfer recording medium of FIG. 3, each layer forms the same solid pattern, but it is not necessary that all the thermal transfer layers provided on the base film have the same shape, and different solid patterns may be formed. .

  The coating amount per unit area of the region a is preferably 25 to 150% with respect to the coating amount per unit area of the region b. By forming the solid pattern of the thermal transfer layer within the above coating amount range, streaky unevenness and film thickness unevenness occurring in the pattern surface can be further suppressed.

  As a base film, what is equivalent to what is used as a base film of a conventionally well-known heat transfer sheet can be used, and it is preferable to have mechanical strength, heat resistance, etc. Examples thereof include synthetic resin films such as polyethylene terephthalate, polyethylene naphthalate, polystyrene, polypropylene, polycarbonate, polyvinyl chloride, polyvinyl alcohol, polysulfone, aliphatic polyamide, aromatic polyamide, polyimide, and polyamideimide. In particular, a polyethylene terephthalate film suitable for physical properties and processability is preferable. These base films can be used alone or as a combined composite. The thickness of the substrate film can be 2 to 50 μm in consideration of operability and workability, but preferably about 2 to 10 μm in consideration of handling properties such as transfer suitability and workability. .

  In order to improve the adhesion between the base film and the heat-resistant slip layer or the thermal transfer layer, an easy-adhesion layer may be provided on one or both surfaces of the base film. Suitable materials for the easy-adhesion layer are those having compatibility with both the base film and the heat-resistant slipping layer or the thermal transfer layer. Specifically, such materials as acrylic acid, methacrylic acid, maleic acid and the like are not suitable. Saturated carboxylic acid resin, polyurethane resin, polyester resin and the like can be mentioned. The easy-adhesion layer has a thickness that does not hinder heat transfer from the thermal head to the thermal transfer layer, and is 0.01 to 1 μm, more preferably 0.05 to 0.5 μm. The easy-adhesion layer can be formed by applying a coating solution on a support by a known coating method. Moreover, in the case of a plastic film, you may form simultaneously in the process of forming a plastic film. Moreover, you may improve adhesiveness by adjusting the surface roughness of the one or both surfaces of a base material, without providing an easily bonding layer. Furthermore, when the thermal transfer layer is a heat sublimable dye layer, a dye diffusion preventing layer that suppresses diffusion of the dye to the substrate side may be provided below the dye layer.

  In order to prevent thermal contraction of the substrate due to the heat of the thermal head and friction of the thermal head, a heat resistant slipping layer is provided on the surface opposite to the surface on which the thermal transfer layer of the substrate is provided. Also good. Examples of the binder used in the heat resistant slipping layer include cellulose resins, polyester resins, acrylic resins, vinyl resins, polyurethane resins, polyether resins, polycarbonate resins, and acetal resins. The thickness of the heat resistant slipping layer is preferably from 0.1 to 2.5 μm, more preferably from 0.5 to 1.5 μm. When the thickness of the heat resistant slipping layer is smaller than 0.1 μm, the heat resistance from the thermal head is inferior, and thermal contraction of the support tends to occur during printing. On the other hand, when the thickness is larger than 2.5 μm, the heat from the thermal head is not sufficiently transmitted to the thermal transfer layer, and a printed matter having a desired density cannot be obtained. The glass transition point of the binder is preferably 40 ° C. or higher. When the glass transition point is 40 ° C or higher, the ribbon strength at the time of printing is further increased, and the edge is cut (a phenomenon in which the non-printing parts on both sides of the ribbon are cut by heat shrinkage), tearing, and tearing (the printing part end point is cut Phenomenon) is less likely to occur.

  Further, the heat resistant slipping layer may contain a lubricant for the purpose of improving slipperiness. For example, natural waxes such as animal waxes and plant waxes, synthetic hydrocarbon waxes, aliphatic alcohols and acid waxes, fatty acid esters and glycerite waxes, synthetic ketone waxes, amine and amide waxes, chlorinated hydrocarbons Waxes, synthetic waxes such as alpha-olefin waxes, higher fatty acid esters such as butyl stearate and ethyl oleate, higher fatty acid metal salts such as sodium stearate, zinc stearate, calcium stearate, potassium stearate, magnesium stearate, Surfactants such as long-chain alkyl phosphate esters, polyoxyalkylene alkyl aryl ether phosphate esters, or phosphate esters such as polyoxyalkylene alkyl ether phosphate esters. By containing the lubricant, the coefficient of dynamic friction between the heat resistant slipping layer and the thermal head can be reduced, so that deformation of the substrate due to the force from the thermal head can be prevented.

  Moreover, you may use a crosslinking agent together in order to improve heat resistance. By containing a crosslinking agent, the heat resistance of the heat resistant slipping layer is improved, and deformation of the substrate due to heat from the thermal head during printing can be prevented. Examples of the cross-linking agent include polyisocyanates, which are used in combinations of acrylic, urethane, and polyester polyol resins, cellulose resins, and acetal resins.

  Furthermore, the heat resistant slipping layer may contain particles. By including particles, irregularities are formed on the surface of the heat resistant slipping layer and the contact area with the thermal head is reduced, so that the releasability of the thermal head during printing is improved. The particles may be either organic particles or inorganic particles, but those that are not deformed by heat from the thermal head are preferred. Specific examples include silica particles, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, talc, kaolin, clay, silicone particles, polyethylene particles, polypropylene particles, polystyrene particles, polymethyl methacrylate resin particles, polyurethane resin particles, and the like. be able to. The particles may be used alone or in combination of two or more.

  The thermal transfer layer 2 is transferred onto the thermal transfer body by heating with a thermal head from the opposite side of the thermal transfer recording medium on which the components contained in the thermal transfer layer or the thermal transfer layer itself is not provided with the thermal transfer layer, A character, an image, or a protective layer is formed.

  For example, in the case where the thermal transfer layer is a dye layer containing a heat sublimable dye, the dye is sublimated by heating with a thermal head and transferred onto the thermal transfer member. In the case where the thermal transfer layer is a melt-transfer layer having a heat-melting property containing a color pigment, the thermal transfer layer itself is transferred onto the thermal transfer member to form characters and images. In the case where the thermal transfer layer is a melt transfer layer composed of a functional additive such as an ultraviolet absorber or an antioxidant and a binder, the thermal transfer layer is transferred as a protective layer for characters and images formed on the thermal transfer member.

  The dye layer as the thermal transfer layer 2 contains a heat sublimable dye and a binder. As this dye, the dye currently used for the conventionally well-known dye layer can be used. For example, diarylmethane, triarylmethane, thiazole, methine, azomethane, xanthene, axazine, thiazine, azine, acridine, azo, spirodipyran, isorinospiropyran, fluorane, rhodamine Examples include ductams and anthraquinones. Specifically, in the yellow component, C.I. I. Solvent Yellow 14, 16, 29, 30, 33, 56, 93 etc., C.I. I. Examples of magenta components such as disperse yellow 7, 33, 60, 141, 201, 231 include C.I. I. Solvent Red 18, 19, 27, 143, 182, C.I. I. Disperse thread 60, 73, 135, 167, C.I. I. As a cyan component such as disperse violet 13, 26, 31, 56, etc., C.I. I. Solvent Blue 11, 36, 63, 105, C.I. I. Disperse Blue 24, 72, 154, 354 and the like are exemplified, but not limited thereto. Further, the dyes may be used alone or in combination of two or more.

  As the binder used in the dye layer, conventionally known binders can be used. Vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl acetal, polyvinyl butyral, ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate Cellulose resins such as cellulose acetate butyrate and cellulose acetate propionate, polyester resins, phenoxy resins, styrene-acrylonitrile copolymer resins, polycarbonate resins, polyacrylamide resins and other resins with excellent heat resistance and dye transfer properties Can be used.

  The glass transition point of the binder of the dye layer is preferably 60 ° C. or higher, more preferably 90 ° C. or higher. When the glass transition point is low, there is a high possibility of causing printing defects. Moreover, 0.1-3.0 are preferable and, as for the weight ratio (dye / binder) of a dye and a binder, 0.5-1.5 are more preferable. If it is less than 0.1, the dye density becomes small, so that the color density becomes insufficient and a good thermal transfer image cannot be obtained. On the other hand, when the ratio is larger than 3.0, the solubility of the dye in the binder is extremely lowered, so that the storage stability of the dye layer is lowered and the dye is likely to precipitate, which is not preferable.

  The dye layer may contain particles. By including particles, irregularities are formed on the surface of the dye layer and the contact area with the receiving layer is reduced, so that sticking during storage can be prevented and releasability during printing can be improved. The particles may be either organic particles or inorganic particles, but those that do not deform due to heat from the thermal head are preferred. Specific examples include silica particles, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, talc, kaolin, clay, silicone particles, polyethylene particles, polypropylene particles, polystyrene particles, polymethyl methacrylate resin particles, polyurethane resin particles, and the like. be able to. The particles may be used alone or in combination of two or more.

  The dye layer may contain a lubricant. By containing a lubricant, sticking between the dye layer and the receiving layer during printing can be prevented. Examples of the lubricant include various oils and surfactants such as silicone-based, fluorine-based, and phosphate-based compounds, and silicone-based or fluorine-based oils and surfactants are particularly preferable. Specifically, straight silicone oils such as dimethyl silicone and methylphenyl silicone, amino modification, epoxy modification, carbinol modification, mercapto modification, carboxyl modification, methacryl modification, polyether modification, phenol modification, one-end reaction as silicone series And non-reactive modified silicone oils such as polyether modified, aralkyl modified, fluoroalkyl modified, long chain alkyl modified, higher fatty acid ester modified, phenyl modified and the like. Examples of the fluorine-based agent include surfactants containing a fluoroalkyl group or a perfluoroalkyl group.

  Furthermore, the dye layer may be used in combination with a crosslinking agent for the purpose of improving heat resistance. By containing a cross-linking agent, the heat resistance is improved, and deformation of the thermal transfer recording medium due to heating from the thermal head can be prevented. Examples of the cross-linking agent include polyisocyanates, which are used in combinations of acrylic, urethane, and polyester polyol resins, cellulose resins, and acetal resins.

  The hot melt transfer layer as the heat transfer layer 2 generally contains a colorant, a binder, and a wax. As the colorant, a known organic pigment or inorganic pigment can be used. Examples of organic pigments include azo pigments such as phthalimide yellow, benzimidazolone orange, sulfoamide yellow, and benzimidazolone yellow, phthalocyanine pigments, diketopyrrolopyrrole, quinophthalone, isoindolinone, and diaminodianthraquinone. Can be mentioned.

  Examples of the binder contained in the hot-melt transfer layer include ethylene-vinyl acetate copolymer, polyamide resin, rosin derivative, acrylic resin, epoxy resin and the like.

  As the wax, paraffin wax, microcrystalline wax, carnauba wax, montan wax, polyethylene wax, ester wax, oxidized wax, or the like is used.

  The protective layer in the thermal transfer layer 2 is a layer for protecting an image formed on the thermal transfer member by a dye layer or the like. The protective layer is peeled off from the thermal transfer body by the thermal transfer method and transferred onto the thermal transfer body, while resistance from ultraviolet rays or the like is required as performance. For this reason, in addition to the case where the protective layer is constituted by a single release layer having resistance, an adhesive layer may be provided on the release layer in order to improve adhesion to the surface of the thermal transfer member. Further, a release layer may be provided between the release layer and the substrate so that the release layer can be easily transferred from the substrate.

  The release layer is provided in order to adjust the degree of peeling of the protective layer from the base material within an appropriate range and ensure stable peelability from the base material, and the degree of peeling is appropriate. It is not always necessary if it is within the range. The material of the release layer is not particularly limited, but for example, water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, natural rubber such as chlorinated rubber and cyclized rubber. Rubber derivatives, natural waxes, waxes such as synthetic waxes, cellulose derivatives such as nitrocellulose, cellulose, cellulose acetate propionate, acrylics, polyurethanes, polyamides, polyimides, polyacetals, chlorinated polyolefins, vinyl chloride -Thermoplastic resins such as vinyl acetate copolymer systems, melamine-based, epoxy-based, polyurethane-based, silicone-based thermosetting resins, and the like.

The release layer is composed of, for example, a binder, an ultraviolet absorber, a functional additive that imparts releasability, slipperiness, and the like, and the thickness of the release layer is preferably about 0.3 to 3 μm. The binder constituting the release layer is not particularly limited except for heat-melting property, but examples include styrene resins such as polystyrene and poly-α-methylstyrene, acrylic resins such as polymethyl methacrylate and polyethyl acrylate. Resin, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyvinyl acetal and other vinyl resins, polyester resin, polyamide resin, epoxy resin, polyurethane resin, petroleum resin, ionomer, ethylene- Synthetic resins such as acrylic acid copolymer, ethylene-acrylic acid ester copolymer, cellulose derivatives such as nitrocellulose, ethyl cellulose, cellulose acetate propionate, rosin, rosin modified maleic resin, ester gum, polyisobutylene rubber, Rugomu, styrene - butadiene rubber, butadiene - acrylonitrile rubbers, natural resins and synthetic rubber derivatives such as polychlorinated olefins, carnauba wax, waxes such as paraffin wax. In particular, acrylic resins, polyester resins, cellulose derivatives, and epoxy resins are preferable.

  Examples of the ultraviolet absorber contained in the release layer include benzophenone, benzotriazole, benzoate, and triazine. Specifically, as an example, benzotriazole-based ultraviolet absorbers include 2- (2H-benzotriazol-2-yl) -p-cresol, 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-benzo Triazol-yl) -4,6-di-tert-pentylphenol, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol and the like and mixtures thereof , Modified products, polymers, derivatives and the like. 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 -Dimethylphenyl) -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 that 1-20 weight part of said ultraviolet absorbers are added with respect to 100 weight part of binders. When the addition amount is less than 1 part by weight, there may be a case where sufficient ultraviolet absorbing ability cannot be exhibited. On the other hand, when added in an amount of 20 parts by weight or more, bleeding out to the surface of the printed matter occurs, and there is a high possibility that the obtained transferred object itself has a problem.

  Moreover, as a functional additive contained in the release layer, silicone oil such as straight silicone and modified silicone, a surfactant having a fluoroalkyl group or a perfluoroalkyl group, a release agent represented by a phosphate ester type, 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.

Regarding the adhesive layer, the binder is not particularly limited except for heat melting property, but examples include styrene resins such as polystyrene and poly α-methylstyrene, acrylic resins 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 acid resin, ester gum, polyisobutylene rubber, butyl rubber, styrene-butadiene rubber, butadiene-acrylonitrile rubber, Examples thereof include natural resins such as polychlorinated olefins, synthetic rubber derivatives, and waxes such as carnauba wax and paraffin wax. In particular, acrylic resins and cellulose derivatives are preferable. If necessary, silicone oils, surfactants, mold release agents, waxes, slip agents represented by organic or inorganic fillers, UV absorbers, light stabilizers, heat stabilizers, flame retardants, antioxidants 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.

Below, the material used for each Example and each comparative example of this invention is shown. In the text, “part” is based on mass unless otherwise specified.
<Base film>
Polyester film: Thickness 4.5μm
<Coating fluid for heat resistant slipping layer>
Acrylic polyol resin 15.0 parts Zinc stearate 1.5 parts Polyoxyalkylene alkyl ether 1.5 parts Talc 1.0 parts 2,6-tolylene diisocyanate 5.0 parts Toluene 50.0 parts Methyl ethyl ketone 20.0 parts Acetic acid 6.0 parts of ethyl <yellow coating liquid for thermal transfer layer>
C. I. Solvent Yellow 93 3.0 parts C.I. I. Solvent Yellow 16 1.0 part Polyvinyl butyral resin 4.2 part Silicone modified resin 0.6 part 2,6-tolylene diisocyanate 0.2 part Tetrahydrofuran 60.0 part Methyl ethyl ketone 31.0 part <Magenta coating liquid for thermal transfer layer>
C. I. Disperse thread 60 1.5 parts C.I. I. Disperse Violet 26 1.5 parts Polyvinyl butyral resin 4.0 parts Silicone-modified resin 0.8 parts 2,6-tolylene diisocyanate 0.2 parts Tetrahydrofuran 60.0 parts Methyl ethyl ketone 31.0 parts <Cyan coating liquid for thermal transfer layer >
C. I. Solvent Blue 63 1.5 parts C.I. I. Solvent Blue 36 1.5 parts Polyvinyl butyral resin 3.8 parts Silicone-modified resin 1.0 part 2,6-tolylene diisocyanate 0.2 part Tetrahydrofuran 60.0 parts Methyl ethyl ketone 31.0 parts <Transfer substrate>
Foamed polyester film: 188μm thick
<Image-receiving layer forming coating solution for thermal transfer>
Vinyl chloride-vinyl acetate-vinyl alcohol copolymer 19.5 parts Amino-modified silicone oil 0.5 part Toluene 40.0 parts Methyl ethyl ketone 40.0 parts

<Preparation of base film with heat-resistant slip layer for thermal transfer recording medium>
By forming a heat-resistant slipping layer with a dry thickness of 0.9 μm on one surface of the base sheet by the gravure coating method, and then aging at 40 ° C. for 5 days, A base film with a heat-resistant slip layer was produced.

<Preparation of transfer object>
Using a gravure coating method, a thermal transfer image receiving layer forming coating is formed on one surface of a transfer substrate using a thermal transfer image receiving layer forming coating solution, and a thermal transfer target is produced by forming a dry thickness of 5.0 μm. did.

<Gravure cylinder for thermal transfer layer formation>
In order to form three types of thermal transfer layers composed of yellow, magenta, and cyan, A to I gravure cylinders shown in Table 1 were prepared.

<Example 1>
100 m of yellow coating liquid for thermal transfer layer, magenta coating liquid for thermal transfer layer, and cyan coating liquid for thermal transfer layer are applied to the non-coated surface of the base film with the thermal slipping layer by gravure printing using cylinder A. At 1 min, the coating layer was dried at 12000 m so that the dry thickness of each layer was 1.0 μm, and a thermal transfer recording medium of Example 1 comprising three thermal transfer layers was produced.

<Example 2>
A thermal transfer recording medium of Example 2 was produced in the same manner as in Example 1 except that cylinder B was used instead of cylinder A.

<Example 3>
A thermal transfer recording medium of Example 3 was produced in the same manner as in Example 1 except that the cylinder C was used instead of the cylinder A.

<Example 4>
A thermal transfer recording medium of Example 4 was produced in the same manner as in Example 1 except that the cylinder D was used instead of the cylinder A.

<Example 5>
A thermal transfer recording medium of Example 5 was produced in the same manner as Example 1 except that cylinder E was used instead of cylinder A.

<Comparative Example 1>
A thermal transfer recording medium of Comparative Example 1 was produced in the same manner as in Example 1 except that the cylinder F was used instead of the cylinder A.

<Comparative example 2>
A thermal transfer recording medium of Comparative Example 2 was produced in the same manner as in Example 1 except that the cylinder G was used instead of the cylinder A.

<Comparative Example 3>
A thermal transfer recording medium of Comparative Example 3 was produced in the same manner as in Example 1 except that the cylinder H was used instead of the cylinder A.

<Comparative example 4>
A thermal transfer recording medium of Comparative Example 4 was produced in the same manner as in Example 1 except that the cylinder I was used instead of the cylinder A.

<Coating surface evaluation>
Table 2 shows the results of visual observation of the coated surfaces at the time of coating at 1000 m, 5000 m, and 10000 m from the start of coating for the thermal transfer recording media of Examples 1 to 5 and Comparative Examples 1 to 4.

<Printing and winding evaluation>
With respect to the thermal transfer recording media of Examples 1 to 5 and Comparative Examples 1 to 4, 5000 m from the start of coating, 200 m from the time of coating, and 200 m from the time of coating are slitted, and the thermal simulator is 22 V, 5 inch / s under conditions. A 40% gray solid print of the entire volume was performed on the transfer object, and the print screen was observed. At the same time, the winding state after printing was visually observed. The results are also shown in Table 3.

  From the results shown in Tables 2 and 3, it can be seen that the thermal transfer recording media of Examples 1 to 5 are all satisfactory from the viewpoints of the coated surface to be obtained, the printed material using the same, and the printer runnability. . In addition to the thermal transfer recording medium of Example 4, a thin streak was confirmed at the time of 10000 m coating, and at the same time, a slight streak-like winding unevenness was confirmed in the winding state after printing, but it had no effect on the printed matter. From this, it can be seen that streaky coating unevenness is substantially improved.

  On the other hand, the thermal transfer recording medium of Comparative Example 1 shows a streak immediately after coating as shown in Table 2, although the length of the region a was changed as compared with the thermal transfer recording medium of Example 4. It turns out that it gets worse with time. Further, as shown in Table 3, since streaks are confirmed in the printed product itself, and large streaky unevenness is confirmed in winding, it can be understood that there is a serious problem of streaky coating unevenness.

  Further, the thermal transfer recording medium of Comparative Example 2 was wound up in winding after printing as shown in Table 3, although the length of the region a was changed as compared with the thermal transfer recording medium of Example 4. Since unevenness is accompanied and wrinkles are confirmed in the printed matter, it can be understood that there is a significant problem in running properties as a thermal transfer recording medium.

In addition, the thermal transfer recording medium of Comparative Example 3 was compared with the thermal transfer recording medium of Example 4 in regions a to
It can be seen that the coated surface is greatly deteriorated over time as shown in Table 2 in spite of only changing the interval with b. Further, as shown in Table 3, since streaks are confirmed in the printed product itself, and large streaky unevenness is confirmed in winding, it can be understood that there is a serious problem of streaky coating unevenness.

  In addition, the thermal transfer recording medium of Comparative Example 4 has a streak immediately after coating as shown in Table 2 in spite of the fact that the distance from the regions a to b is changed as compared with the thermal transfer recording medium of Example 4. Along with this, it can be seen that it has deteriorated over time. Further, as shown in Table 3, since streaks are confirmed in the printed product itself, and large streaky unevenness is confirmed in winding, it can be understood that there is a serious problem of streaky coating unevenness.

  The thermal transfer recording medium obtained by the present invention is an ink ribbon used in a thermal transfer type printer, and various images can be easily formed in full color in conjunction with higher functionality of the printer. Cards such as certificates, amusement output, etc. are widely used.

DESCRIPTION OF SYMBOLS 1 ... Thermal transfer recording medium 2 ... Thermal transfer layer 3 ... Area | region b
4. Area a
5 ... Base film 6 ... Impression roll 7 ... Gravure plate 8 ... Ink pan 9 ... Yellow layer 9a ... Yellow layer region a
9b: Yellow layer region b
10 ... Magenta layer 10a ... Magenta layer region a
10b: Magenta layer region b
11 ... Cyan layer 11a ... Cyan layer region a
11b Cyan layer region b

Claims (4)

In the method for producing a thermal transfer recording medium, one or two or more thermal transfer layers are provided by applying a coating liquid for thermal transfer layer by gravure printing and drying on one surface of a continuously running base film.
At least one thermal transfer layer is composed of two regions a and b in order from the running direction,
The length of the region a in the traveling direction is 1 to 7 mm,
A method for producing a thermal transfer recording medium, comprising: applying and drying a thermal transfer layer coating liquid with an interval of 0.5 to 2 mm in the running direction between the area a and the area b.   2. The method of manufacturing a thermal transfer recording medium according to claim 1, wherein a coating amount per unit area of the region a is 5 to 150% with respect to a coating amount per unit area of the region b. . In the thermal transfer recording medium, wherein one or two or more thermal transfer layers are provided on one surface of the base film,
At least one thermal transfer layer is composed of two regions a and b in order from the running direction,
The length of the region a in the traveling direction is 1 to 7 mm,
A thermal transfer recording medium, wherein an interval of 0.5 to 2 mm is provided in the running direction between the area a and the area b.   4. The thermal transfer recording medium according to claim 3, wherein a coating amount per unit area of the region a is 5 to 150% with respect to a coating amount per unit area of the region b.

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