JP2009262355A - Sublimable heat transfer medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal ribbon with such advantages that the transfer of a dye in a dye layer can be prevented from occurring, and at the same time, the color reproducibility is excellent and the fusing of the thermal ribbon with an object to which an image is transferred, during printing, does not take place. <P>SOLUTION: This sublimable heat transfer medium has a heat-resistant resin layer (2) formed on the back of a substrate (1) and at least, the dye layer (4) composed of a resin binder containing a sublimable dye on the other face. In addition, a thin film layer (5) containing an acrylic resin with a silicone, is formed on the dye layer (4), and the thin film layer (5) is of a dispersed organic or inorganic filler (6). The average particle diameter of the organic or inorganic filler (6) is larger than the thickness of the thin film layer (5). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sublimation type thermal transfer medium that performs full-color printing, and relates to a sublimation type thermal transfer medium that ensures the temporal stability of the medium and improves color reproducibility during printing.

  In general, a sublimation type thermal transfer medium is called a thermal ribbon, and is an ink ribbon used in a thermal transfer type printer. A heat-resistant resin layer (back coat layer) is formed on one surface of a substrate, A dye layer (thermal transfer layer) is provided on the other surface. Here, the dye layer is an ink 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 transferred to the transfer target side. .

  At present, the thermal transfer system can easily form various images in combination with higher functionality of a printer, so that it is widely used for amusement output including cards such as identification cards. In this way, with the diversification of applications, there is a growing demand for durability on the obtained printed matter. In recent years, the sensitivity of thermal ribbons has been increased to increase the number of images to be printed and to increase the speed of printers.

  With the increase in speed of the printer, the thermal head that gives thermal energy is also improved and the temperature becomes instantaneously high, so that the thermal ribbon and the transfer object may be fused. It describes that silicone oil is added to the dye layer of the thermal ribbon so that the thermal ribbon and the transfer target are not fused.

  However, when a large amount of silicone oil is added to prevent the thermal ribbon from being fused, the dye is transferred together with the silicone oil and the back surface of the thermal ribbon is soiled. A dirty thermal ribbon on the back surface may contaminate the thermal head that gives thermal energy. If it is not good, the heat of the thermal head may not be transmitted and partial printing may be lost.

  For example, it is proposed to add protein particles to the resin binder of the dye layer described in Patent Document 2. Addition of protein particles prevents fusion between the thermal ribbon and the transferred material, but has not yet reached the transfer of the dye on the surface of the dye layer.

Further, for example, in Patent Document 3, it is proposed to provide a thin film made of a non-dyeing resin or a low dyeing resin on a dye layer. Although it is possible to prevent migration of the dye by providing a thin film made of a non-dyeing resin or a low dyeing resin, it is not a thermal ribbon that has a low density of printed matter and can withstand high speed printers.
Japanese Patent No. 3123663 JP 2004-351822 A Japanese Patent No. 3178869

  The present invention has been made in view of such circumstances, and prevents thermal migration of the dye in the dye layer and at the same time has good color reproducibility during printing and does not cause fusion between the thermal ribbon and the transfer object. The issue is the provision of ribbons.

In order to solve the above problems in the present invention, first, in the invention of claim 1,
A thin film containing an acrylic resin containing silicone on a dye layer in a sublimation type thermal transfer medium provided with a heat resistant resin layer on the back surface of the substrate and at least a dye layer containing a sublimation dye in a resin binder on the other surface A sublimation type thermal transfer medium is provided with a layer.

In the invention of claim 2,
2. The sublimation thermal transfer medium according to claim 1, wherein the thin film layer is obtained by dispersing an organic or inorganic filler, and the average particle diameter of the organic or inorganic filler is larger than the thickness of the thin film layer. It is what.

In the invention of claim 3,
3. The sublimation type thermal transfer medium according to claim 1, wherein at least one kind of resin contained in the dye layer is added to the thin film layer.

In the invention of claim 4,
The sublimation thermal transfer medium according to any one of claims 1 to 3, wherein the thin film layer has a thickness of 1 µm or less.

In the invention of claim 5,
5. The sublimation thermal transfer medium according to claim 1, wherein the thin film layer is provided on each dye layer containing a sublimable dye of cyan, magenta, yellow, or black. It is a thing.

  According to the present invention, even when stored in a ribbon state for a long time, migration of the dye in the dye layer can be prevented, and color reproducibility at the time of printing is good. It is possible to provide a thermal ribbon that does not cause fusion.

  Hereinafter, a sublimation thermal transfer medium according to the best embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view of a sublimation type thermal transfer medium as an embodiment of the present invention. 2 is a cross-sectional view taken along the line XY in FIG. 1 of a sublimation type thermal transfer medium as an embodiment of the present invention, and FIG. 3 is a partially enlarged view of FIG. 2 and is used in a thermal transfer type printer. An example of a mold thermal transfer medium is shown.

  As shown in FIGS. 1 and 2, the dye layer (4) has three colors of yellow (Y), magenta (M), and cyan (C) or black (BK) on one surface of the substrate (1). The four-color dye layer (4) that is included has a structure in which the heat-resistant resin layer (2) is provided on the other surface of the substrate (1) in the surface direction in the longitudinal direction.

  On the other hand, the thin film layer (5) of the present invention is sequentially provided on the dye layer (4), and the thin film layer (5) is functionally equivalent to be provided partially or continuously for each color. It is.

The base material (1) of the sublimation type thermal transfer medium is required to have heat resistance and strength that is not softened and deformed by heat pressure in thermal transfer. For example, polyethylene terephthalate, polyethylene naphthalate, polypropylene, cellophane, acetate, polycarbonate, polysulfone, polyimide , A film of a synthetic resin such as polyvinyl alcohol, aromatic polyamide, aramid, polystyrene, etc., and paper such as condenser paper, paraffin paper, etc. can be used alone or in combination. In consideration of processability and cost, a polyethylene terephthalate film is preferable. Further, the thickness can be in the range of 2 to 50 μm in consideration of operability and workability, but in consideration of handling properties such as transfer suitability and workability, the thickness is about 2 to 12 μm. preferable.

  The heat-resistant resin layer (2) is composed of, for example, a functional additive that imparts releasability and slipperiness, and a binder, and can be cured with a curing agent as necessary. The thickness of the heat resistant resin layer is suitably about 0.1 to 2 μm (dry thickness).

  An example of the heat-resistant resin layer (2) is a resin obtained by adding a release agent such as silicone oil to a synthetic resin such as UV-cured acrylic oligomer, polyester, polyurethane, polyacetal, polyamide, polyimide, and silicone. Can be mentioned. Moreover, even if it adds a filler as needed, there is no problem, and examples of the filler to be added include silicone powder, silica, and various resin powders.

  As the protective layer (3) for protecting the printed image, the durability of the image formed on the transferred material by the dye layer (4) from ultraviolet rays or the like is required, and at the same time, the image is transferred by a process called a thermal transfer method. Since it needs to be formed on the body, in general, an adhesive layer having both the original performance as a protective layer such as ultraviolet absorption and adhesiveness to the transferred body, and the lower layer during thermal transfer from the substrate It is generally formed from a laminate of a plurality of layers such as a release layer for easy peeling.

  The protective layer (3) is composed of, for example, a functional additive such as an ultraviolet absorber and a binder, and the thickness of the adhesive layer is suitably about 1 to 5 μm (dry thickness).

  Examples of adhesive layer functional additives that impart an adhesive function to the protective layer (3) include benzophenone, benzotriazole, benzoate, UV absorbers typified by triazines, and light stabilizers typified by hindered amines. And antioxidants typified by hindered phenols, fluorescent brighteners, antistatic agents and the like. In addition, the binder is not particularly limited except for heat melting property. For example, 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 resins such as polyvinyl butyral, polyvinyl acetal, polyester resin, polyamide resin, epoxy resin, polyurethane resin, petroleum resin, ionomer, ethylene-acrylic Synthetic resins such as acid copolymers, ethylene-acrylic acid ester copolymers, cellulose derivatives such as nitrocellulose, ethyl cellulose, cellulose acetate propionate, rosin, rosin-modified maleic acid resin, ester gum, polyisobutylene rubber, butyl rubber , Styrene - acrylonitrile rubbers, natural resins and derivatives of synthetic rubber polychlorinated olefins such as carnauba wax, waxes such as paraffin wax - butadiene rubber, butadiene. Among these, acrylic resins, polyesters, and epoxy resins are preferable.

  The release layer imparting the release function for forming the protective layer (3) is composed of, for example, a functional additive that imparts releasability and slipperiness, and a binder, and the thickness of this release layer is 0.3 to 3 μm. The degree (dry thickness) is appropriate.

Examples of functional additives used in the release layer include silicone oils, release agents typified by phosphate esters, waxes, slip agents typified by resin fillers, UV absorbers, light stabilizers, and antioxidants. Agents, fluorescent brighteners, antistatic agents and the like. In addition, the binder is not particularly limited except for heat melting property. For example, 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 resins such as polyvinyl butyral, polyvinyl acetal, polyester resin, polyamide resin, epoxy resin, polyurethane resin, petroleum resin, ionomer, ethylene-acrylic Synthetic resins such as acid copolymers, ethylene-acrylic acid ester copolymers, cellulose derivatives such as nitrocellulose, ethyl cellulose, cellulose acetate propionate, rosin, rosin-modified maleic acid resin, ester gum, polyisobutylene rubber, butyl rubber , Styrene - acrylonitrile rubbers, natural resins and derivatives of synthetic rubber polychlorinated olefins such as carnauba wax, waxes such as paraffin wax - butadiene rubber, butadiene. Among these, acrylic resins and cellulose derivatives are preferable.

  The dye layer (4) of the sublimation type thermal transfer medium is composed of, for example, a heat sublimable dye and a binder, and the thickness of this dye layer is suitably about 1 μm (dry thickness).

  As the sublimation dye used in the dye layer, a sublimation disperse dye is preferable. For example, examples of yellow components include Solvent Yellow 56, 16, 30, 93, 33, Disperse Yellow 201, 231, 33, and the like. Is mentioned. Examples of the magenta component include C.I. I. Disperse thread 60, C.I. I. Disperse violet 26, C.I. I. Solvent Red 27, or C.I. I. Solvent Red 19 etc. are mentioned. As the cyan component, C.I. I. Disperse Blue 354, C.I. I. Solvent Blue 63, C.I. I. Solvent Blue 36, or C.I. I. Disperse Blue 24 and the like. As the ink dye, it is common to perform color matching by combining the above dyes.

  The binder used in the dye layer is not particularly limited, but cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, and cellulose acetate, polyvinyl alcohol, polyvinyl acetate, and polyvinyl butyral. Vinyl acetal, polyvinyl pyrrolidone, polyacrylamide, and other vinyl resins, polyester resins, styrene-acrylonitrile copolymer resins, phenoxy resins, and the like. Among these, polyvinyl butyral, styrene-acrylonitrile copolymer resin, and phenoxy resin are preferable.

  Here, the ratio of the dye to the binder in the dye layer is preferably dye / binder = 10/100 to 300/100. This is because if the dye / binder ratio is less than 10/100, the amount of dye is too small and the color development sensitivity is insufficient, and a good thermal transfer image cannot be obtained, and if this ratio exceeds 300/100, the binder This is because the solubility of the dye with respect to is extremely reduced, so that the storage stability of the dye layer is deteriorated and the dye is likely to precipitate.

  The thin film layer (5) needs to prevent fusion with the transfer medium when printing the sublimation thermal transfer medium with a printer, and further sublimate the dye to transfer the dye to the transfer medium. In addition, there is a function to prevent the dye from floating on the front surface and transferring to the back surface of the sublimation thermal transfer medium when printing is not performed. The thickness of this thin film layer is suitably 1 μm or less (dry thickness). When the thickness of the thin film layer exceeds 1 μm, the dye sublimation of the dye layer is hindered, resulting in poor printing. On the other hand, the lower limit of thickness is suitably about 0.1 μm (dry thickness) when a printing method such as gravure printing is used. On the other hand, if the thickness is less than 0.1 μm, film formation failure occurs and it is difficult to prevent migration of the dye in the dye layer.

The binder used for the thin film layer (5) is an acrylic resin containing silicone. Silicone may be added as silicone oil, or an acrylic resin copolymerized with silicone. Furthermore, the resin used for the dye layer (4) can be added and used in addition to the resin. The resin that can be added is not particularly limited, but cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, and cellulose acetate, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, Examples thereof include vinyl resins such as polyvinyl pyrrolidone and polyacrylamide, polyester resins, styrene-acrylonitrile copolymer resins, and phenoxy resins. Among these, polyvinyl butyral, styrene-acrylonitrile copolymer resin, and phenoxy resin are preferable.

  The thin film layer (5) needs to sublimate and transfer the dye to the transfer medium at the time of printing. For this purpose, an organic or inorganic filler (6) is added. The filler (6) to be added has a larger average particle diameter (diameter) than the thickness of the thin film. Examples of the filler (6) that can be added include silicone beads, silica, polyethylene beads, and ceramic beads.

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

Example 1
The heat resistant resin layer forming ink, the release layer forming ink, the adhesive layer forming ink, the sublimation heat transfer forming yellow ink, and the sublimation heat transfer forming magenta used for preparing the sublimation type thermal transfer medium of Example 1 are shown below. The compositions of ink, cyan ink for sublimation thermal transfer formation, and thin film layer ink are listed.

<Heat resistant resin layer forming ink>
Epoxy acrylate 45.0 parts Hexanediol diacrylate 20.0 parts Initiator 1.0 part Silicone oil 6.0 parts Silica 3.0 parts Methyl alcohol 25.0 parts

<Ink for peeling layer formation>
Acrylic resin 18.0 parts Polyester resin 1.0 part Polyethylene powder 1.0 part Toluene 40.0 parts Methyl ethyl ketone 40.0 parts

<Adhesive layer forming ink>
Acrylic resin 10.0 parts Polyester resin 5.0 parts Epoxy resin 5.0 parts Benzophenone UV absorber 5.0 parts Toluene 35.0 parts Methyl ethyl ketone 40.0 parts

<Yellow ink for sublimation thermal transfer formation>
C. I. Solvent Yellow 93 3.0 parts C.I. I. Solvent Yellow 16 1.0 part Phenoxy resin 5.0 parts Tetrahydrofuran 60.0 parts Toluene 31.0 parts

<Magenta ink for sublimation thermal transfer formation>
C. I. Disperse thread 60 1.5 parts C.I. I. Disperse Violet 26 1.5 parts Phenoxy resin 5.0 parts Tetrahydrofuran 60.0 parts Toluene 32.0 parts

<Cyan ink for sublimation thermal transfer formation>
C. I. Solvent Blue 63 1.5 parts C.I. I. Solvent Blue 36 1.5 parts Phenoxy resin 5.0 parts Tetrahydrofuran 60.0 parts Toluene 32.0 parts

<Thin layer ink>
Acrylic modified silicone resin 18.0 parts Polyethylene powder 2.0 parts Toluene 40.0 parts Methyl ethyl ketone 40.0 parts

A heat-resistant resin layer was obtained by forming a heat-resistant resin layer ink with a dry thickness of 0.8 μm on one surface of a substrate by a gravure coating method using a polyester film having a thickness of 4.5 μm as a substrate. After forming the release layer with a dry thickness of 0.8 μm on the other surface using the release layer forming ink, the adhesive layer is formed on the release layer with the dry layer thickness of 2.0 μm using the adhesive layer forming ink. Forming a protective layer. Next, using various yellow inks for forming sublimation heat transfer, magenta ink, and cyan ink prepared at predetermined positions, the dye layers were formed in a surface sequence with a dry thickness of 1.0 μm to obtain a dye layer. A sublimation type thermal transfer medium of Example 1 was prepared by forming a thin film layer with a dry thickness of 0.2 μm using a thin film layer ink on the dye layer to obtain a thin film layer.

(Example 2)
The composition of the thin film layer ink used to prepare the sublimation type thermal transfer medium of Example 2 is shown below. The materials and inks described in Example 1 were used except for the thin film layer ink.

<Thin layer ink>
Acrylic modified silicone resin 18.0 parts Phenoxy resin 2.0 parts Silicone beads 2.0 parts Toluene 39.0 parts Methyl ethyl ketone 39.0 parts

A heat-resistant resin layer was obtained by forming a heat-resistant resin layer ink with a dry thickness of 0.8 μm on one surface of a substrate by a gravure coating method using a polyester film having a thickness of 4.5 μm as a substrate. After forming the release layer with a dry thickness of 0.8 μm on the other surface using the release layer forming ink, the adhesive layer is formed on the release layer with the dry layer thickness of 2.0 μm using the adhesive layer forming ink. Forming a protective layer. Next, using various yellow inks for forming sublimation heat transfer, magenta ink, and cyan ink prepared at predetermined positions, the dye layers were formed in a surface sequence with a dry thickness of 1.0 μm to obtain a dye layer. On the dye layer, a thin film layer was formed with a dry thickness of 0.2 μm using a thin film layer ink to obtain a thin film layer, and a sublimation type thermal transfer medium of Example 2 was prepared.

(Example 3)
The composition of the thin film layer ink used to prepare the sublimation type thermal transfer medium of Example 3 is shown below. The materials and inks described in Example 1 were used except for the thin film layer ink.

<Thin layer ink>
Acrylic modified silicone resin 18.0 parts Phenoxy resin 2.0 parts Silica 1.0 part Toluene 40.0 parts Methyl ethyl ketone 39.0 parts

A heat-resistant resin layer was obtained by forming a heat-resistant resin layer ink with a dry thickness of 0.8 μm on one surface of a substrate by a gravure coating method using a polyester film having a thickness of 4.5 μm as a substrate. After forming the release layer with a dry thickness of 0.8 μm on the other surface using the release layer forming ink, the adhesive layer is formed on the release layer with the dry layer thickness of 2.0 μm using the adhesive layer forming ink. Forming a protective layer. Next, using various yellow inks for forming sublimation heat transfer, magenta ink, and cyan ink prepared at predetermined positions, the dye layers were formed in a surface sequence with a dry thickness of 1.0 μm to obtain a dye layer. A sublimation type thermal transfer medium of Example 3 was prepared by forming a thin film layer with a dry thickness of 0.2 μm using a thin film layer ink on the dye layer to obtain a thin film layer.

(Comparative Example 1)
A heat-resistant resin layer was obtained by forming a heat-resistant resin layer ink with a dry thickness of 0.8 μm on one surface of a substrate by a gravure coating method using a polyester film having a thickness of 4.5 μm as a substrate. After forming the release layer with a dry thickness of 0.8 μm on the other surface using the release layer forming ink, the adhesive layer is formed on the release layer with the dry layer thickness of 2.0 μm using the adhesive layer forming ink. Forming a protective layer. Next, using various yellow inks for forming sublimation heat transfer, magenta ink, and cyan ink at predetermined positions, dye layers are formed in a sequential order with a dry thickness of 1.0 μm to obtain a dye layer to create a sublimation thermal transfer medium. did. The material and ink described in Example 1 were used, and a sublimation type thermal transfer medium of Comparative Example 1 was prepared without providing a thin film layer on the dye layer.

(Comparative Example 2)
The composition of the thin film layer ink used to prepare the sublimation type thermal transfer medium of Comparative Example 2 is shown below. The materials and inks described in Example 1 were used except for the thin film layer ink.

<Thin layer ink>
Acrylic modified silicone resin 20.0 parts Toluene 40.0 parts Methyl ethyl ketone 40.0 parts

A heat-resistant resin layer was obtained by forming a heat-resistant resin layer ink with a dry thickness of 0.8 μm on one surface of a substrate by a gravure coating method using a polyester film having a thickness of 4.5 μm as a substrate. After forming the release layer with a dry thickness of 0.8 μm on the other surface using the release layer forming ink, the adhesive layer is formed on the release layer with the dry layer thickness of 2.0 μm using the adhesive layer forming ink. Forming a protective layer. Next, using various yellow inks for forming sublimation heat transfer, magenta ink, and cyan ink prepared at predetermined positions, the dye layers were formed in a surface sequence with a dry thickness of 1.0 μm to obtain a dye layer. On the dye layer, a thin film layer was formed by using a thin film layer ink to a dry thickness of 0.2 μm to obtain a thin film layer to prepare a sublimation type thermal transfer medium.

  In the above-mentioned Examples and Comparative Examples, printing and printing products and dye transferability were evaluated under the following conditions.

(Print and print evaluation)
The sublimation type thermal transfer media obtained in Examples and Comparative Examples were printed with ISO SCID images under the conditions shown in Table 1 using a thermal simulator in combination with the transfer medium, and each print was obtained.

For printing, the following media were used as transfer media.

<Transfer material>
Foamed polyester film: 188μm thick

<Sublimation thermal transfer image-receiving layer forming ink>
Vinyl chloride-vinyl acetate-vinyl alcohol copolymer 20.0 parts Silicone oil 0.5 part Toluene 40.0 parts Methyl ethyl ketone 39.5 parts

<Production of transfer medium>
By forming a sublimation heat transfer image-receiving layer with a dry thickness of 5.0 μm on one surface of the substrate to be transferred using a gravure coating method, a transfer substrate for sublimation heat transfer is formed. A medium was made.

(Dye transferability evaluation)
The dye transferability was visually evaluated after standing at room temperature for 36 hours at 4.9 kPa.

  Table 2 shows the evaluation results regarding the prints and prints, and the dye transferability.

In addition, although evaluation was evaluated by ○ △ ×, ○ means that the target performance was realized, Δ means the same as in the past, and × means that the product cannot withstand practical use.

  According to the evaluation results of the examples and comparative examples, the sublimation type thermal transfer medium provided with the thin film layer of the present invention was in a state where the printing was sufficiently practical and there was no dye transfer on the back surface. On the other hand, in Comparative Example 1, adhesion due to fusion with the transfer medium was confirmed at the time of printing, and further migration of the dye was confirmed. In Comparative Example 2, no dye transfer was observed, but printing on the transfer medium was not possible.

It is a top view of a sublimation type thermal transfer medium as an embodiment of the present invention. It is sectional drawing in XY of FIG. 1 of the sublimation type thermal transfer medium as embodiment of this invention. FIG. 2 is an enlarged cross-sectional view in which a cross-sectional view taken along the line XY in FIG. 1 of the sublimation type thermal transfer medium as an embodiment of the present invention is partially enlarged.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base material 2 ... Heat resistant resin layer 3 ... Protective layer 4 ... Dye layer 5 ... Thin film layer 6 ... Filler

Claims (5)

  A thin film containing an acrylic resin containing silicone on a dye layer in a sublimation type thermal transfer medium provided with a heat resistant resin layer on the back surface of the substrate and at least a dye layer containing a sublimation dye in a resin binder on the other surface A sublimation type thermal transfer medium, comprising a layer.   2. The sublimation thermal transfer medium according to claim 1, wherein the thin film layer is obtained by dispersing an organic or inorganic filler, and the average particle diameter of the organic or inorganic filler is larger than the thickness of the thin film layer. .   3. The sublimation type thermal transfer medium according to claim 1, wherein at least one kind of resin contained in the dye layer is added to the thin film layer.   The sublimation thermal transfer medium according to claim 1, wherein the thin film layer has a thickness of 1 μm or less.   The sublimation thermal transfer medium according to claim 1, wherein the thin film layer is provided on each dye layer containing a sublimable dye of cyan, magenta, yellow, or black.