JP6442979B2 - Thermal transfer recording medium and printing method - Google Patents

Description

  The present invention relates to a thermal transfer recording medium used in a thermal transfer printer.

In general, a thermal transfer recording medium is called an ink ribbon, which is an ink ribbon used in a thermal transfer printer, and is provided with a heat-resistant slipping layer (back coat layer) on one side of a substrate. A thermal transfer layer (dye layer) is provided on the other surface of the material. Here, the thermal transfer layer is an ink (dye) layer, and the ink is sublimated (sublimation transfer method) or melted (melt transfer method) by the heat generated in the thermal head of the printer, and is transferred to the transfer target side. Transcript.
Currently, among the thermal transfer systems, the sublimation transfer system can easily form full-color images with various functions of the printer, so digital camera self-prints, cards such as identification cards, amusement output, etc. Widely used.

Along with the diversification of applications described above, there is a growing demand for miniaturization, high speed, low cost, environmental compatibility, and durability for the printed material obtained. A thermal transfer recording medium having a plurality of thermal transfer layers provided so as not to overlap with a protective layer for imparting durability to a printed material has become widespread.
Under the circumstances described above, a protective film with excellent durability is used in order to ensure stable use of the printer even when a large amount of printing is performed due to diversification and widespread use. The thermal head that was used may be used. Among these thermal heads, the thermal conductivity is high due to the material of the protective film, so that an instantaneous load on the thermal transfer recording medium increases when trying to maintain a sufficient print density. There is also. Further, in order to reduce the cost of the entire medium, the print density may be maintained by reducing the amount of dye used and increasing the output of the printer. When printing is performed with such a printer having a combination of high instantaneous loads on the thermal transfer recording medium, there is a problem in that a printing defect due to wrinkles occurs, and in some cases, the thermal transfer recording medium breaks.

Wrinkles that occur during printing of thermal transfer recording media are caused by sticking of the substrate and the thermal head or deterioration of the thermal transfer recording media when the heat-resistant slip layer has insufficient lubricity and heat resistance. There is a case.
As a method for solving the problem of wrinkle generation at the time of printing, Patent Document 1 improves the lubricity at the time of high energy printing by adding metal soap and filler together with silicone-modified resin to the heat resistant slipping layer, A method for preventing wrinkles during printing has been proposed.

JP 2006-306017 PR

However, when printing was performed using a recent printer using a thermal transfer recording medium having a heat resistant slipping layer proposed in Patent Document 1, generation of wrinkles was confirmed.
In view of the above problems, the present invention is based on the premise that the thermal conductivity of the thermal head protective film used in the printer is high, the momentary load on the thermal transfer recording medium is high, or the amount of dye used is reduced. An object of the present invention is to provide a thermal transfer recording medium and a printing method capable of preventing wrinkles during printing while obtaining a sufficient printing density even when printing is performed using an output voltage printer. Is.

In order to solve the above problems, one embodiment of the present invention includes a base material, a heat-resistant slip layer formed on one surface of the base material, a dye layer formed on the other surface of the base material, The heat-resistant slipping layer comprises a binder made of a reaction product of a thermoplastic resin and a polyvalent isocyanate or a thermoplastic resin, and particles having a multilayer structure, and particles having a multilayer structure. the core portion has a higher thermal conductivity than the thermal conductivity of the binder, the shell of the multi-layered particles are an endothermic reaction shows below and 250 ° C. at 60 ° C. or higher during heating, the multilayer structure grains The content of is not less than 1% by mass and less than 10% by mass .

  According to one embodiment of the present invention, since the core portion of the multi-layered particle has a thermal conductivity higher than that of the binder, heat can be efficiently transferred to the dye layer. Further, since the outer shell of the multi-layered particle exhibits an endothermic reaction during heating, the instantaneous heat applied from the thermal head can be reduced. Therefore, generation of wrinkles during printing can be prevented while maintaining a sufficient printing density.

1 is a cross-sectional view illustrating a schematic configuration of a thermal transfer recording medium according to an embodiment. It is sectional drawing which shows the structure of the particle | grains of the multilayer structure which a heat resistant slipping layer contains.

Embodiments of the present invention will be described below with reference to the drawings.
(overall structure)
FIG. 1 is a cross-sectional view showing a schematic configuration of a thermal transfer recording medium 1 of the present embodiment.
As shown in FIG. 1, the thermal transfer recording medium 1 includes a base material 10, a heat resistant slipping layer 30, and a dye layer 20.
(Configuration of multi-layered particle 40)
FIG. 2 is a cross-sectional view of the multi-layered particle 40 contained in the heat resistant slipping layer 30.
As shown in FIG. 2, the particle 40 having a multilayer structure includes a core part 50 and an outer shell 60.

(Configuration of base material 10)
The base material 10 is required to have heat resistance and strength that are not softened and deformed by heat pressure in thermal transfer.
For this reason, as a material of the substrate 10, for example, polyethylene terephthalate, polyethylene naphthalate, polypropylene, cellophane, acetate, polycarbonate, polysulfone, polyimide, polyvinyl alcohol, aromatic polyamide, aramid, polystyrene, and other synthetic resin films, and Paper such as condenser paper and paraffin paper can be used alone or in combination. In view of physical properties, workability, cost, etc., among the materials described above, a polyethylene terephthalate film is preferable.

Moreover, the thickness (length in the vertical direction in FIG. 1) of the substrate 10 can be in the range of 2 μm to 50 μm in consideration of operability and workability. In particular, when handling properties such as transfer suitability and workability are taken into consideration, those of about 2 μm to 9 μm are preferable.
Further, in the base material 10, the surface on which the heat resistant slipping layer 30 is formed (the lower surface in FIG. 1) and the surface on which the dye layer 20 is formed (the upper surface in FIG. 1). It is also possible to perform an adhesion treatment, and either one or both of the surfaces to be subjected to the adhesion treatment may be performed.
As the above-mentioned adhesion treatment, it is possible to apply known techniques such as corona treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, plasma treatment, primer treatment, and the like. Two or more types can be used in combination.
In the present embodiment, as a suitable example, it is effective to improve the adhesion between the base material 10 and the dye layer 20, and a primer-treated polyethylene terephthalate film can also be used from the viewpoint of cost.

(Configuration of heat resistant slipping layer 30)
The heat-resistant slip layer 30 is a layer formed on one surface of the base material 10, and is a layer that imparts slip properties with the thermal head to the thermal transfer recording medium 1. The heat resistant slipping layer 30 in the present embodiment contains a reaction product of a thermoplastic resin and a polyvalent isocyanate or a binder made of a thermoplastic resin, and particles 40 having a multilayer structure, and a core portion of the particles 40 having a multilayer structure. 50 is a thermal head having a thermal conductivity higher than that of the binder, and the outer shell 60 of the multi-layered particle 40 has an endothermic reaction when heated, thereby having a protective film having a high thermal conductivity. Even when an image is formed using thermal transfer, it is possible to prevent wrinkling during printing while maintaining a sufficient printing density.

  The heat-resistant slipping layer 30 contains a core part 50 having a thermal conductivity higher than that of the binder and a particle 40 having a multilayer structure having an outer shell 60 that exhibits an endothermic reaction when heated, so that heat is efficiently generated. Therefore, the instantaneous heat applied from the thermal head can be reduced, and the thermal load applied to the thermal transfer recording medium 1 can be reduced. At this time, the temperature at which the outer shell 60 of the multi-layered particle 40 exhibits an endothermic reaction is 60 ° C. or more and less than 250 ° C., so that the instantaneous heat applied from the thermal head can withstand the printing density. Can be relaxed. If an endothermic reaction is exhibited at a temperature lower than 60 ° C. or higher than 250 ° C., the instantaneous heat load cannot be reduced.

Further, the endothermic amount of the outer shell 60 in the particles 40 having a multilayer structure was 100 mJ / mg or more and less than 300 mJ / mg. Thereby, the instantaneous heat applied from the thermal head can be reduced to a range that can withstand the maintenance of the print density. If the endothermic amount is less than 100 mJ / mg, the instantaneous heat load cannot be reduced, and if it exceeds 300 mJ / mg, the color development is inferior.
Further, the heat resistant slipping layer 30 of the present embodiment has a higher effect when a thermal head having a protective film having a high instantaneous thermal load and a thermal conductivity at 25 ° C. of 30 W / m · K or more is used. (In this embodiment, an image is formed by thermal transfer using a thermal head having a protective film having a thermal conductivity of 30 W / m · K or higher at 25 ° C.).

The heat-resistant slip layer 30 includes, for example, a resin serving as a binder, a core portion 50 having a thermal conductivity higher than that of the binder, and a multi-layered particle 40 having an outer shell 60 that exhibits an endothermic reaction when heated. Prepare a coating solution for forming the heat-resistant slipping layer 30 by blending functional additives that give releasability and slipperiness, fillers, curing agents, solvents, etc. as necessary. It can be formed by coating and drying.
As a binder made of a reaction product of a thermoplastic resin and a polyvalent isocyanate used for the heat resistant slipping layer 30 or a thermoplastic resin, polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer, Use polyether resin, polybutadiene resin, polystyrene resin, acrylic polyol, polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, nitrocellulose resin, cellulose acetate resin, polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, etc. Is possible.

In addition, isocyanates such as tolylene diisocyanate, triphenylmethane triisocyanate, tetramethylxylene diisocyanate, and derivatives thereof can be appropriately used as the curing agent.
As the multi-layered particle 40 having the core 50 having a thermal conductivity higher than that of the binder and the outer shell 60 exhibiting an endothermic reaction when heated, those having physical properties corresponding to those of the existing multi-layered particle 40 are used. You may choose. In addition, particles that are insoluble in the solvent are used as the core part 50, and a material that is soluble in the solvent is added as the outer shell 60. After the material that forms the outer shell 60 is dissolved, it is deposited around the core part 50. May be. In that case, as the material for the core portion 50, there is no particular problem as long as the relationship of the thermal conductivity with the material for the binder meets the conditions, and various organic inorganic particles can be used. , Mica, kaolinite, forsterite, mullite, zirconia, talc, zircon, silica, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, clay, silicone particles, polyethylene resin particles, polypropylene resin particles, polystyrene resin particles, polymethyl Any of the methacrylate resin particles and polyurethane resin particles that meet the conditions can be used particularly preferably.

  The material for the outer shell 60 is not particularly limited as long as it exhibits an endothermic reaction at 60 ° C. or more and less than 250 ° C., but natural waxes such as animal waxes and plant waxes, and synthetic hydrocarbon waxes. , Aliphatic alcohols and acid waxes, fatty acid esters and glycerite waxes, synthetic ketone waxes, amine and amide waxes, chlorinated hydrocarbon waxes, alpha-olefin waxes, synthetic waxes, butyl stearate, ethyl oleate Higher fatty acid esters such as sodium stearate, zinc stearate, calcium stearate, potassium stearate, magnesium stearate, etc., higher fatty acid metal salts, long chain alkyl phosphates, polyoxyalkylene alkyl aryl ether phosphates or Among surfactants such as phosphoric acid esters such as oxyalkylene alkyl ether phosphoric acid esters, those that meet the conditions can be used particularly suitably, and the endothermic amount is 100 mJ / mg or more. And if it is less than 300 mJ / mg, it can be used more suitably. When the endothermic amount is less than 100 mJ / mg, the effect of mitigating heat given from the thermal head is reduced. On the other hand, when it exceeds 300 mJ / mg, the endothermic effect is great and the color development is reduced.

By using the material of the multi-layered particle 40 having the core part 50 having a thermal conductivity higher than the heat conduction efficiency of the binder and the outer shell 60 exhibiting an endothermic reaction at the time of heating, it has a high thermal conductivity. Even when an image is formed by thermal transfer using a thermal head having a protective film, it is possible to prevent wrinkling during printing while maintaining a sufficient printing density. Moreover, these endothermic temperatures and endothermic amounts can be measured by DSC or the like.
Further, the content of the multi-layered particles 40 having the core portion 50 having a heat conductivity higher than the heat conduction efficiency of the binder and the outer shell 60 exhibiting an endothermic reaction during heating is 1% by mass or more of the heat resistant slipping layer 30. And less than 10% by mass. When the amount is less than 1% by mass, the effect of mitigating heat given from the thermal head is reduced. On the other hand, if it exceeds 10% by mass, the endothermic effect is great and the color development is reduced. Therefore, by setting the content of the particles 40 of the multilayer structure to 1% by mass or more and less than 10% by mass, the effect of reducing the heat given from the thermal head is improved and the endothermic effect is greatly improved and the color development is improved. be able to.

  Similarly, functional additives include animal waxes, natural waxes such as plant waxes, synthetic hydrocarbon waxes, aliphatic alcohols and acid waxes, fatty acid esters and glycerite waxes, synthetic ketone waxes, amines and the like. Synthetic waxes such as amide wax, chlorinated hydrocarbon wax, alpha-olefin wax, higher fatty acid esters such as butyl stearate and ethyl oleate, sodium stearate, zinc stearate, calcium stearate, potassium stearate, stearic acid Surface activity of higher fatty acid metal salt such as magnesium, long chain alkyl phosphate ester, polyoxyalkylene alkyl aryl ether phosphate ester or phosphate ester such as polyoxyalkylene alkyl ether phosphate ester It is possible to use such agents.

As the filler, talc, silica, mica, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, kaolinite, clay, silicone particles, polyethylene resin particles, polypropylene resin particles, polystyrene resin particles, polymethyl methacrylate resin particles Etc. can be used.
Moreover, the application amount after drying of the heat resistant slipping layer 30 is suitably about 0.1 g / m ² or more and 2.0 g / m ² or less.
Here, the coating amount after drying of the heat-resistant slipping layer 30 indicates the amount of solid content remaining after the coating liquid for forming the heat-resistant slipping layer 30 is applied and dried. Similarly, the coating amount of the dye layer 20 after drying indicates the amount of solid content remaining after the coating liquid is applied and dried.

(Configuration of dye layer 20)
The dye layer 20 is a layer formed on the other surface of the substrate 10. For example, a coating liquid (for formation) for forming the dye layer 20 by blending a heat transfer dye, a binder, a solvent, or the like is used. It is formed by preparing, applying and drying.
The heat transferable dye is a dye that melts, diffuses, or sublimates and transfers due to heat.
Among the heat transfer dyes, examples of the yellow component include C.I. I. Solvent Yellow 56, 16, 30, 93, 33, C.I. I. Disperse Yellow 201, 231, 33, etc. can be used.
Among the heat transfer dyes, examples of the magenta component include C.I. I. Disperse violet 26, 31, C.I. I. Disperse thread 60, C.I. I. Solvent red 19, 27, etc. can be used.

Among the heat transfer dyes, examples of the cyan component include C.I. I. Disperse blue 24,257,354, C.I. I. Solvent blue 36, 63, 266, etc. can be used.
In general, the ink dye is toned by combining the above-described dyes.
As the resin contained in the dye layer 20, any conventionally known resin binder can be used and is not particularly limited, but includes ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and the like. Cellulose resins, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, polyacrylamide, and other vinyl resins, polyester resins, styrene-acrylonitrile copolymer resins, phenoxy resins, and the like can be used.

Here, the mixing ratio of the dye and the resin in the dye layer 20 is preferably (dye) / (resin) = 10/100 or more and less than 300/100 on a mass basis.
This is because if the ratio of (dye) / (resin) is less than 10/100, the amount of dye is too small and the color density becomes insufficient, and a good thermal transfer image cannot be obtained. If it exceeds the above range, the solubility of the dye in the resin is extremely lowered, and therefore, when the thermal transfer recording medium 1 is obtained, the storage stability is deteriorated and the dye may be easily precipitated. .
The dye layer 20 may contain known additives such as an isocyanate compound, a silane coupling agent, a dispersant, a viscosity modifier, and a stabilizer as long as the performance is not impaired.

An appropriate coating amount of the dye layer 20 after drying is about 1.0 g / m ² . The dye layer 20 can be composed of a single layer of one color, and a plurality of dye layers 20 containing dyes having different hues are sequentially and repeatedly formed on the same surface of the same substrate 10. It is also possible to do.
In addition, a layer is provided between the base material 10 and the dye layer 20 and between the base material 10 and the heat-resistant slipping layer 30 for the purpose of imparting functionality such as improvement in adhesion and improvement in dye utilization efficiency. It is also possible.
The heat resistant slipping layer 30 and the dye layer 20 can be formed by applying and drying by a conventionally known coating method.
As a coating method, for example, a gravure coating method, a screen printing method, a spray coating method, a reverse roll coating method, or a die coating method can be used.

(Example)
Hereinafter, the effects of the thermal transfer recording medium 1 of the present invention will be verified using Examples (Examples 1 to 9, Comparative Examples 1 to 5) with reference to FIG. In addition, when described as “parts” in the following description, unless otherwise specified, mass reference is shown. Similarly, when the thermal conductivity is described next to the material name, the thermal conductivity at 25 ° C. is indicated unless otherwise specified. The present invention is not limited to the following examples.
In Examples and Comparative Examples described below, a transfer object for thermal transfer was produced by the method described below.
・ Production of Transferred Body A double-sided resin-coated paper having a thickness of 190 μm was used as a base material, and a heat-insulating layer coating liquid having the composition shown below was applied on one side by a die-coating method to a coating amount after drying of 8.0 g. A heat insulating layer is formed by coating and drying so as to be / m ² , and then an image receiving layer coating solution having the composition shown below is applied onto the upper surface of the heat insulating layer by a gravure coating method to a coating amount after drying of 4.0 g The material to be transferred for thermal transfer was prepared by coating and drying so as to be / m ² .

・ Insulation layer coating solution Acrylic-styrene hollow particles 35.0 parts (average particle diameter 1 μm, volume hollowness 51%)
Styrene-butadiene rubber 10.0 parts Pure water 55.0 parts Dispersant Trace amount Defoaming agent Trace amount / image-receiving layer coating solution 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

Example 1
A polyethylene terephthalate film with a single-sided easy-adhesion treatment having a thickness of 4.5 μm is used as the substrate 10, and a coating solution having the composition shown below (the heat-resistant slipping layer 30 of Example 1 is formed on the non-adhesive-adhesion-treated surface The coating solution for the coating, hereinafter referred to as “coating solution-1 for forming the heat resistant slipping layer 30”) is applied by the gravure coating method so that the coating amount after drying is 0.5 g / m ² , The heat resistant slipping layer 30 was formed by drying at a temperature of 100 ° C. for 1 minute.
In addition, as a method of forming the particles 40 having a multilayer structure, after the material that becomes the outer shell 60 is heated and melted in a solvent, the material that becomes the core portion 50 is charged and dispersed, and then gradually cooled. It was obtained by precipitating around 50.
A coating liquid (coating liquid for forming the dye layer 20, hereinafter referred to as “dye layer coating liquid”) having the following composition is applied to the easy-adhesion treated surface of the substrate 10 on which the heat-resistant slip layer 30 is formed. By the gravure coating method, the applied amount after drying is 0.70 g / m ² and dried at 90 ° C. for 1 minute to form the dye layer 20, and the thermal transfer recording of Example 1 Medium 1 was obtained.

-Coating liquid for forming heat resistant slipping layer 30-1
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core 50: Kaolinite Outer shell 60: Lithium hydroxystearate)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts Dye layer coating solution C.I. I. Solvent Blue 63 6.0 parts Polyvinyl acetal resin 4.0 parts Toluene 45.0 parts Methyl ethyl ketone 45.0 parts

(Example 2)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slipping layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slipping layer 30 of Example 2, hereinafter referred to as “heat-resistant slipping”. The thermal recording transfer recording medium 11 of Example 2 was obtained in the same manner as in Example 1 except that it was described as “Coating liquid 2 for forming layer 30”.
-Coating liquid-2 for forming heat resistant slipping layer 30
Butyral resin 35.5 parts Multilayer structured particles 5.0 parts
(Core 50: Kaolinite Outer shell 60: Lithium hydroxystearate)
Mica 3.5 parts Zinc stearate 6.0 parts MEK 30.0 parts Toluene 20.0 parts

Example 3
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slip layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slip layer 30 of Example 3, hereinafter referred to as “heat-resistant slip property”). A thermal recording transfer recording medium 11 of Example 3 was obtained in the same manner as in Example 1 except that it was described as “Coating liquid 3 for forming layer 30”.
-Coating liquid for forming heat resistant slipping layer 30-3
Butyral resin 36.0 parts Multilayer structure particles 0.75 parts
(Core 50: Kaolinite Outer shell 60: Lithium hydroxystearate)
Mica 5.0 parts Zinc stearate 8.25 parts MEK 30.0 parts Toluene 20.0 parts

(Example 4)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slip layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slip layer 30 of Example 4, hereinafter “heat-resistant slip property”). A thermal recording transfer recording medium 11 of Example 4 was obtained in the same manner as in Example 1 except that it was described as “Coating liquid 4 for forming layer 30”.
-Coating liquid for forming heat resistant slipping layer 30-4
Butyral resin 36.0 parts Multilayer structure particles 0.25 parts
(Core 50: Kaolinite Outer shell 60: Lithium hydroxystearate)
Mica 5.25 parts Zinc stearate 8.5 parts MEK 30.0 parts Toluene 20.0 parts

(Example 5)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slip layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slip layer 30 of Example 5, hereinafter referred to as “heat-resistant slip property”). The thermal recording transfer recording medium 11 of Example 5 was obtained in the same manner as in Example 1 except that it was described as “Coating solution 5 for forming layer 30”.
・ Coating fluid for forming heat resistant slipping layer 30-5
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core 50: Kaolinite Outer shell 60: Calcium stearate)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts

(Example 6)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slip layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slip layer 30 of Example 6, hereinafter referred to as “heat-resistant slip property”). The thermal recording transfer recording medium 11 of Example 6 was obtained in the same manner as in Example 1 except that it was described as “Coating liquid 6 for forming layer 30”.
・ Coating liquid for forming heat resistant slipping layer 30-6
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core 50: Kaolinite Outer shell 60: Lithium laurate)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts

(Example 7)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slip layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slip layer 30 of Example 7, hereinafter referred to as “heat-resistant slip property”. A thermal recording transfer recording medium 11 of Example 7 was obtained in the same manner as in Example 1 except that it was described as “Coating solution 7 for forming layer 30”.
・ Coating liquid for forming heat resistant slipping layer 30-7
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core 50: Magnesium oxide outer shell 60: Calcium laurate)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts

(Example 8)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slipping layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slipping layer 30 of Example 8, hereinafter referred to as “heat-resistant slipping”. The thermal recording transfer recording medium 11 of Example 8 was obtained in the same manner as in Example 1 except that it was described as “Coating solution 8 for forming layer 30”.
-Coating liquid for forming heat resistant slipping layer 30-8
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core 50: Kaolinite Outer shell 60: Lithium stearate)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts

Example 9
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slip layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slip layer 30 of Example 9, hereinafter referred to as “heat-resistant slip property”). The thermal recording transfer recording medium 11 of Example 9 was obtained in the same manner as in Example 1 except that the coating liquid for forming layer 30 was described as “9”.
・ Coating liquid for forming heat resistant slipping layer 30-9
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core 50: Kaolinite Outer shell 60: Stearic acid)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts

(Comparative Example 1)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slipping layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slipping layer 30 of Comparative Example 1, hereinafter “heat-resistant slipping property”). A thermal recording transfer recording medium 11 of Comparative Example 1 was obtained in the same manner as in Example 1 except that it was described as “Coating liquid 10 for forming layer 30”.
-Coating solution for forming heat-resistant slipping layer 30 -10
Butyral resin 35.0 parts Mica 5.0 parts Zinc stearate 10.0 parts MEK 30.0 parts Toluene 20.0 parts

(Comparative Example 2)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slip layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slip layer 30 of Comparative Example 2, hereinafter referred to as “heat-resistant slip property”). The thermal recording transfer recording medium 11 of Comparative Example 2 was obtained in the same manner as in Example 1 except that it was described as “Coating liquid 11 for forming layer 30”.
-Coating liquid for forming heat resistant slipping layer 30-11
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core 50: Kaolinite Outer shell 60: Polyoxyethylene alkyl ether phosphate)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts

(Comparative Example 3)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slip layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slip layer 30 of Comparative Example 3, hereinafter “heat-resistant slip property”). The thermal recording transfer recording medium 11 of Comparative Example 3 was obtained in the same manner as in Example 1 except that the coating liquid for forming the layer 30 was described as “12”.
-Coating liquid for forming heat resistant slipping layer 30 -12
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core 50: Kaolinite Outer shell 60: Sodium stearate)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts

(Comparative Example 4)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slip layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slip layer 30 of Comparative Example 4, hereinafter referred to as “heat-resistant slip property”. A thermal recording transfer recording medium 11 of Comparative Example 4 was obtained in the same manner as in Example 1 except that the coating liquid for forming the layer 30 was described as “13”.
-Coating liquid for forming heat resistant slipping layer 30 -13
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core part 50: silicone filler outer shell 60: lithium hydroxystearate)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts

(Comparative Example 5)
In the heat-sensitive transfer recording medium 1 produced in Example 1, the heat-resistant slipping layer 30 was coated with a coating solution having the composition shown below (a coating solution for forming the heat-resistant slipping layer 30 of Comparative Example 5, hereinafter referred to as “heat-resistant slipping property”). A thermal recording transfer recording medium 11 of Comparative Example 5 was obtained in the same manner as in Example 1 except that the coating liquid for forming layer 30 was described as “14”.
-Coating liquid for forming heat resistant slipping layer 30-14
Butyral resin 35.0 parts Multilayer structure particles 2.5 parts
(Core 50: Polyamideimide outer shell 60: Lithium hydroxystearate)
Mica 4.5 parts Zinc stearate 8.0 parts MEK 30.0 parts Toluene 20.0 parts

(Evaluation)
Hereinafter, for the thermal transfer recording media 1 of Examples 1 to 9 and Comparative Examples 1 to 5, using a thermal head having a protective film with a thermal conductivity of 28 W / m · K and 35 W / m · K, a thermal simulator was used. The prints used were evaluated. The results of evaluating the print density and the print wrinkle using Table 1 will be described.
Evaluation method As an evaluation method, a thermal head having a protective film with a thermal conductivity of 28 W / m · K was used for the thermal transfer recording media 1 of Examples 1 to 9 and Comparative Examples 1 to 5 to evaluate wrinkles. , 24V, 27V, and two patterns with different printing energies, printing evaluation of black solid images was performed at a speed of 10 inches / sec. For sensitivity evaluation, the 255 gradations are divided, the high density side is 255 gradations, the low gradation side is 46 gradations, the medium gradation side is 178 gradations, and the high gradation side is the print density of 255 gradations. Was measured. Regarding the print density, measurement was performed on black.
In addition, using a thermal head having a protective film with a thermal conductivity of 35 W / m · K, as a wrinkle evaluation, a black solid image was evaluated at a speed of 10 inches / sec with respect to 24V.

-Wrinkle evaluation Evaluation of printing defects due to wrinkles was performed according to the following criteria. It should be noted that if no wrinkle is generated at a voltage of 24 V, there is no problem in practical use.
○: No print defects due to wrinkles on the printed material △: Print defects due to small wrinkles generated from the edges ×: Print defects due to wrinkles at the edges and center

-Print density evaluation Regarding print density, the range of the design value ± 2% was used as a reference, and there was no problem if the following range was taken into account the measurement error of the device.
24V
46 gradations: reflection density 0.20 to 0.22
178 gradations: reflection density 1.00 to 1.04
255 gradations: reflection density 2.02 to 2.10
27V
46 gradations: reflection density 0.30 to 0.23
178 gradations: reflection density 1.22-1.26
255 gradations: reflection density 2.14 to 2.22

Evaluation Results From the results shown in Table 1, it was confirmed that the thermal transfer recording media 1 of Examples 1 to 9 had no problem from the viewpoint of wrinkles and print density. In particular, in the thermal transfer recording media 1 of Examples 1 to 3 and 7 to 9, it was confirmed that no wrinkle was generated even when the voltage was 27 V, and there was no problem with the print density. In Example 4, when the printing energy is as high as 27 V, wrinkles are generated, and in Example 2, the printing density shows the lower limit. Thus, the multilayer structure particle 40 is 1% by mass or more and 10% by mass. It is preferable that it is less than.

In Example 5, wrinkles were generated when the printing energy was as high as 27 V, and since the printing density in Example 6 showed the lower limit, the endothermic amount was 100 mJ / mg or more and less than 300 mJ / mg. It is preferable that
In addition, when a thermal head having a protective film with a thermal conductivity of 28 W / m · K is used, the thermal transfer recording medium 1 of Comparative Examples 1 to 5 does not wrinkle or is generated. When a thermal head having a protective film with a thermal conductivity of 35 W / m · K is used as a weak wrinkle generated at the end, the thermal transfer recording medium 1 of Comparative Examples 1 to 5 has a central portion. Strong wrinkles that occur are confirmed. In both conditions, generation of wrinkles was not confirmed in the thermal transfer recording media 1 of Examples 1 to 9. For this reason, the thermal transfer recording medium 1 of the present invention is preferable because it exhibits a particularly strong effect when a thermal head having a protective film having a thermal conductivity of 30 W / m · K or more is used.

Further, from the results of Example 1 and Comparative Examples 1 to 4, wrinkles are likely to occur when the multi-layered particles 40 are not present, or the endothermic temperature of the outer shell 60 is higher than 250 ° C. or lower than 60 ° C. It has been confirmed that when the thermal conductivity of the core part 50 is lower than the thermal conductivity of the binder, a sufficient print density cannot be obtained.
In this embodiment, the base material 10 in FIG. 1 constitutes the base material. Similarly, the heat resistant slipping layer 30 in FIG. 1 constitutes the heat resistant slipping layer. Moreover, the dye layer 20 of FIG. 1 comprises a dye layer. Furthermore, the core part 50 of FIG. Further, the outer shell 60 of FIG. 1 constitutes the outer shell. Further, the thermal transfer recording medium 1 of FIG. 1 constitutes a thermal transfer recording medium.

(Effect of this embodiment)
The invention according to this embodiment has the following effects.
(1) In the thermal transfer recording medium 1 according to this embodiment, the base material 10, the heat-resistant slip layer 30 formed on one surface of the base material 10, and the dye formed on the other surface of the base material 10 A heat-sensitive slipping layer 30 comprising a binder made of a reaction product of a thermoplastic resin and a polyvalent isocyanate or a thermoplastic resin, and particles 40 having a multilayer structure. And the core part 50 of the particles 40 of the multilayer structure has a thermal conductivity higher than the thermal conductivity of the binder, and the outer shell 60 of the particles 40 of the multilayer structure is 60 ° C. or more and less than 250 ° C. when heated. It shall show an endothermic reaction.
According to such a configuration, since the core part 50 of the particles 40 having a multilayer structure has a thermal conductivity higher than that of the binder, heat can be efficiently transmitted to the dye layer 20. In addition, since the outer shell 60 of the multi-layered particle 40 exhibits an endothermic reaction during heating, instantaneous heat applied from the thermal head can be reduced. Therefore, according to such a configuration, generation of wrinkles during printing can be prevented while maintaining a sufficient printing density.

(2) In the thermal transfer recording medium 1 according to this embodiment, the content of the multi-layer structured particles 40 is 1% by mass or more and less than 10% by mass.
According to such a configuration, it is possible to improve the effect of relieving heat given from the thermal head and to improve color development with a large endothermic effect.
(3) In the thermal transfer recording medium 1 according to the present embodiment, the endothermic amount of the outer shell 60 is 100 mJ / mg or more and less than 300 mJ / mg.
According to such a configuration, instantaneous heat given from the thermal head can be reduced to a range that can withstand the maintenance of the print density.
(4) According to the printing method according to the present embodiment, an image is formed by thermal transfer on a thermal transfer recording medium 1 using a thermal head having a protective film having a thermal conductivity at 25 ° C. of 30 W / m · K or more. Form.
According to such a configuration, a more sufficient printing density can be maintained.

  The thermal transfer recording medium 1 obtained by the present invention can be used in a sublimation transfer type printer, and can easily form full-color images in combination with the high speed and high functionality of the printer. It can be widely used for cards such as self-prints and identification cards, and amusement output.

DESCRIPTION OF SYMBOLS 1 Thermal transfer recording medium 10 Base material 20 Dye layer 30 Heat resistant slipping layer 40 Particle | grain 50 Core part 60 Outer shell

Claims (3)

A substrate;
A heat resistant slipping layer formed on one surface of the substrate;
A thermal transfer recording medium having a dye layer formed on the other surface of the substrate,
The heat-resistant slipping layer contains a reaction product of a thermoplastic resin and a polyvalent isocyanate or a binder made of a thermoplastic resin, and particles having a multilayer structure,
The core of the multi-layered particle has a thermal conductivity higher than the thermal conductivity of the binder,
The outer shell of the particles of the multi-layer structure, an endothermic reaction was shown below and 250 ° C. at 60 ° C. or higher during heating,
The heat-sensitive transfer recording medium, wherein the content of the particles having the multilayer structure is 1% by mass or more and less than 10% by mass . 2. The thermal transfer recording medium according to claim 1, wherein the heat absorption amount of the outer shell is 100 mJ / mg or more and less than 300 mJ / mg. An image is formed by thermal transfer on the thermal transfer recording medium according to claim 1 or 2, using a thermal head having a protective film having a thermal conductivity at 25 ° C. of 30 W / m · K or more. Characteristic printing method.

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