JP2015214102A - Heat-sensitive transfer recording medium and heat-sensitive transfer print - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-sensitive transfer recording medium used in a printer of a heat-sensitive transfer method, the heat-sensitive transfer recording medium capable of easily imparting a mat texture to an image obtained by the heat-sensitive transfer method using a protective layer, while preventing deterioration of precision or image clarity of the image.SOLUTION: A heat-sensitive transfer recording medium includes: a thermostable lubricity layer on one surface of a base material (10); and a heat-transfer protective layer (30) with a release layer (20) and a protective layer (30) sequentially laminated at least in a part of on the other surface of the base material (10). If the thickness of the release layer (20) is a, and the thickness of the protective layer (30) is b, b is equal to or larger than a. The release layer (20) includes first spherical filler (21) being spherical filler and having a particle size within a range of 0.5a to 2a. The protective layer (30) includes second spherical filler (31) being resin-based spherical organic filler, the same as the protective layer (30), and having a particle size within a range of 0.5b-2b and equal to or larger than 2a.

Description

  The present invention relates to a thermal transfer recording medium used in a thermal transfer type printer, and more particularly, to a thermal transfer recording medium in which a thermal transferable protective layer is peelably formed on a substrate, and a thermal transfer printed matter printed using the same. About.

  In general, a thermal transfer recording medium is an ink ribbon called a thermal ribbon, which is used in a thermal transfer type printer, and has a thermal transfer layer on one side of the substrate and heat resistance on the other side of the substrate. A slipping layer (back coat layer) is provided. Here, the heat-sensitive transfer layer is an ink layer, and the ink is sublimated (sublimation transfer method) or melted (melt transfer method) by heat generated in the thermal head of the printer, and transferred to the transfer target side. is there.

  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. With such diversification of applications, there is a growing demand for durability on the output products obtained, and the feeling of having multiple thermal transfer layers provided on the same side of the base sheet so as not to overlap the thermal transfer protective layer. Thermal transfer recording media have become quite popular.

Under such circumstances, there has been a growing demand for a thermal transfer recording medium, which has an improved design by providing a matte-like protective layer, mainly for amusement output. As a constituent factor of the matte tone, the glossiness representing the reflectivity of the surface and the image clarity indicating how clear the image transferred by the reflection is raised, and it is necessary to reduce both as a sensual matte feeling.
For example, in Patent Document 1, the surface is roughened by adding a filler to the release layer remaining on the base material, but the glossiness is lowered by simply adding the filler to the release layer. Although it is possible, it is difficult to reduce the image clarity.

  In addition, Patent Document 2 discloses a method of roughening the surface by putting particles that are thermally expanded on the surface of the protective layer to be transferred, but the particles whose surface gloss is greatly reduced in the protective layer. If this is included, the image will be clouded white due to the influence of the refractive index and the like, which is not preferable.

Japanese Patent No. 4142517 Japanese Patent No. 4662662

  Accordingly, in view of the above problems, the present invention provides a thermal transfer recording medium that reduces the glossiness and image clarity of an image while easily giving a matte tone to an image obtained by the thermal transfer method using a protective layer. Another object of the present invention is to provide a thermal transfer printed matter printed using the same.

  The thermal transfer recording medium according to an aspect of the present invention is a thermal transfer recording medium in which a heat-resistant slipping layer is provided on one surface of a substrate, and a release layer and a protective layer are sequentially laminated on at least a part of the other surface of the substrate. In a thermal transfer recording medium having a protective layer, when the thickness of the release layer is a and the thickness of the protective layer is b, b is a or more, the release layer is a spherical filler and has a particle size. A first spherical filler in the range of 0.5a to 2a is included, and the protective layer is a spherical organic filler having the same resin system as the protective layer, and the particle size is in the range of 0.5b to 2b and 2a or more. A second spherical filler within.

  The second spherical filler contained in the protective layer surface and the protective layer is preferably an acrylic resin. The first spherical filler contained in the release layer is preferably inorganic, organic, or a mixed bead. The release layer thickness a is in the range of 0.5 μm to 6.0 μm, and the protective layer thickness b is in the range of 0.5 μm to 30.0 μm, and within the range of a or more. Is preferred. The particle diameter of the first spherical filler is preferably 2 μm or more. The thermal transfer printed matter according to one embodiment of the present invention is printed using the above thermal transfer recording medium.

  According to one aspect of the present invention, a heat-resistant slipping layer is provided on one surface of a base material, and a thermal transferable protective layer in which a release layer and a protective layer are sequentially laminated on at least a part of the other surface of the base material. In the thermal transfer recording medium, when the thickness of the release layer is a, the release layer includes a first spherical filler having a particle size in the range of 0.5a to 2a, and the thickness of the protective layer is b. And b is a or more, and the protective layer contains a second spherical filler that is the same resin system as the protective layer and has a particle size in the range of 0.5b or more and 2b or less and 2a or more. Thus, it is possible to reduce both the glossiness and image clarity of the image while easily giving a matte tone to the image (thermal transfer printed matter) obtained by the thermal transfer method using a protective layer.

1 is a side sectional view of a thermal transfer recording medium according to an embodiment of the present invention. FIG. 4 is a side sectional view showing a state where a thermal transfer protective layer is peeled off during transfer in a thermal transfer recording medium.

<Embodiment>
Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 1, the thermal transfer recording medium according to the embodiment of the present invention is provided with a heat-resistant slipping layer 50 that imparts slidability with a thermal head on one surface of the substrate 10, and the other of the substrate 10. The heat transferable protective layer 40 formed to be peelable is provided on the surface. The thermal transferable protective layer 40 has a configuration in which a release layer 20 remaining on the substrate 10 after transfer and a protective layer 30 transferred to an image obtained by a thermal transfer method are sequentially laminated. As shown in FIG. 2, the protective layer 30 is peeled off from the release layer 20 and transferred to an image obtained by a thermal transfer method, and the release layer 20 remains on the substrate 10 after transfer. Here, the thickness of the release layer 20 is a. The thickness of the protective layer 30 is b. b is a or more. A first spherical filler 21 which is a spherical filler is added to the release layer 20. The particle diameter of the first spherical filler 21 is 0.5a (= 1/2 × a) or more and 2a (= 2 × a) or less. A second spherical filler 31 that is a spherical filler and is the same resin system as the protective layer 30 is added to the protective layer 30. The particle diameter of the second spherical filler 31 is 0.5b (= 1/2 × b) or more and 2b (= 2 × b) or less and 2a or more. In this embodiment, the particle size of the filler is an average particle size. For example, the particle diameter of the first spherical filler 21 is the average particle diameter of the first spherical filler 21, and the particle diameter of the second spherical filler 31 is the average particle diameter of the second spherical filler 31. However, actually, the particle size of each filler may satisfy the above-mentioned conditions, not the average particle size.

  The base material 10 is required to have heat resistance and strength that is not softened and deformed by heat pressure in thermal transfer. Examples of the substrate 10 include polyethylene terephthalate, polyethylene naphthalate, polypropylene, cellophane, acetate, polycarbonate, polysulfone, polyimide, polyvinyl alcohol, aromatic polyamide, aramid, polystyrene, and other synthetic resin films, condenser paper, and paraffin paper. Or the like can be used alone or in combination as a composite. Among these, a polyethylene terephthalate film is preferable in view of physical properties, workability, cost, and the like. In addition, the thickness can be in the range of 2 μm to 50 μm in consideration of operability and workability, but in consideration of handling properties such as transfer suitability and workability, it is about 2 μm to 9 μm. Those are preferred.

Moreover, in the base material 10, it is also possible to perform an adhesion treatment on the surface on which the heat resistant slipping layer 50 and / or the heat transferable protective layer 40 is formed. As the adhesion treatment, known techniques such as corona treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, roughening treatment, plasma treatment, primer treatment, etc. can be applied, and these treatments are used in combination. You can also
Next, the heat resistant slipping layer 50 can cope with a conventionally well-known thing. For example, a coating solution for forming a heat-resistant slipping layer is prepared by blending a resin serving as a binder, a functional additive that imparts releasability and slipperiness, a filler, a curing agent, a solvent, and the like, and coating and drying. Can be formed. The film thickness after drying of the heat-resistant slip layer 50 is suitably about 0.1 μm or more and 2.0 μm or less.

  As an example of the heat resistant slipping layer 50, as the binder resin, polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer, polyether resin, polybutadiene resin, acrylic polyol, polyurethane acrylate, Examples thereof include polyester acrylate, polyether acrylate, epoxy acrylate, nitrocellulose resin, cellulose acetate resin, polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, polyacrylic resin, and modified products thereof.

  Next, as the binder resin used for the release layer 20, any conventionally known resin having excellent release properties can be used. Examples of the binder resin used for the release layer 20 include cellulose resin, silicone resin, silicone modified resin, fluorine resin, fluorine modified resin, melamine resin, polyvinyl alcohol, acrylic resin, acrylic-styrene resin, and thermal crosslinkability. Examples include epoxy-amino resins and heat-crosslinkable alkyd-amino resins. These release resins can be used alone or as a mixture. In addition, a small amount of an ethylene vinyl acetate copolymer resin, a polyester resin, or the like can be added in order to improve the adhesion to the substrate.

  In this embodiment, the release layer 20 is formed from the binder which consists of the resin material which has the mold release property shown above, and the 1st spherical filler 21 which consists of 1 or more types of fillers. The surface of the formed release layer 20 has a fine uneven shape with different shapes. Examples of the first spherical filler 21 include inorganic silica beads, alumina beads, zirconia beads, and glass beads, organic acrylic beads, melamine beads, and silicone beads. The organic first spherical filler 21 may be hardened with a curing agent such as isocyanate or melamine. Moreover, the 1st spherical filler 21 may be individual or may mix multiple types irrespective of an inorganic type and an organic type.

  As the resin for forming the protective layer 30, any conventionally known resins having excellent durability and transparency can be used. Examples of the resin for forming the protective layer 30 include, but are not limited to, an acrylic resin, a cellulose resin, a polyvinyl acetal resin, and a polyester resin. In particular, an acrylic resin is preferable from the viewpoint of durability and transparency. In addition, the protective layer may have a plurality of layers in order to improve adhesion and durability. Furthermore, functional additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, a catalyst accelerator, a colorant, a gloss adjuster, a fluorescent brightener, and an antistatic agent can be added as necessary.

  When the protective layer 30 has a plurality of layers, an adhesive layer that comes into contact with the image receiving paper at the time of transfer is provided, but the binder resin used for the adhesive layer is not particularly limited except for heat melting property. For example, polystyrene, styrene resin such as poly α-methylstyrene, acrylic resin such as polymethyl methacrylate, polyethyl acrylate, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, Vinyl resins such as polyvinyl acetal, polyester resins, polyamide resins, epoxy resins, polyurethane resins, petroleum resins, ionomers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymer synthetic resins, nitrocellulose, ethyl cellulose , Cellulose derivatives such as cellulose acetate propionate, rosin, rosin-modified maleic resin, ester gum, polyisobutylene rubber, butyl rubber, styrene-butadiene rubber, butadiene-acrylonitrile rubber, polychlorinated Natural resins and derivatives of synthetic rubber such as olefins, carnauba wax, waxes such as paraffin wax.

  In the present embodiment, the protective layer 30 is formed of the above-described binder made of the resin material and the second spherical filler 31 made of one or more organic fillers. The surface of the formed protective layer 30 has fine uneven shapes having different shapes. The second spherical filler 31 is the same resin system as the surface of the protective layer after printing. Examples of the second spherical filler 31 include organic acrylic fillers, melamine fillers, and silicone fillers. Further, the second spherical filler 31 may be hardened with a curing agent such as isocyanate or melamine. Moreover, the 2nd spherical filler 31 may be individual, or may mix multiple types.

  In the present embodiment, in each of the release layer 20 and the protective layer 30, the relationship between the layer thickness and the filler to be added becomes important. In the protective layer 30 to be transferred, the glossiness can be effectively reduced by combining large unevenness and small unevenness. At this time, if the haze of the protective layer 30 is increased while the gloss of the surface is lowered, the fineness and sharpness of the image are lowered, which is not preferable. As long as unevenness is provided on the surface, the increase in external haze cannot be suppressed, but if the internal haze is also increased, the haze becomes too high. For this reason, the transfer to the protective layer 30 can be a factor of increasing the internal haze. An inorganic filler having a refractive index significantly different from that of the resin used on the surface of the protective layer can be used only in the release layer 20 that is not transferred.

  On the other hand, for the second spherical filler 31 having the protective layer surface and the resin system aligned, the internal haze is difficult to increase even if it is in the protective layer 30, so that the image clarity is reduced as large as possible unevenness. I want to use it. Therefore, when the thickness of the release layer 20 is a, the particle diameter of the first spherical filler 21 is 0.5a to 2a, and the particle diameter of the second spherical filler 31 used in the protective layer is When the thickness of the layer 30 is b, it is 0.5b or more and 2b or less and 2a or more, preferably 1b or more and 2b or less and 2a or more. By setting it as such a particle size, since the 1st spherical filler 21 of the mold release layer 20 stays in the mold release layer 20 reliably, it becomes possible to suppress a raise of a haze, and the 2nd of the protective layer 30 can be suppressed. The spherical filler 31 can form irregularities larger than the irregularities on the surface in the protective layer 30. Furthermore, by setting the particle diameter of the second spherical filler 31 to 2a or more, the second spherical filler 31 is made larger than the first spherical filler 21, and the surface gloss is reduced by the first spherical filler 21. The image clarity can be reduced by the second spherical filler 31.

  The amount of filler added is 5 wt% or more and 100 wt% or less, preferably 10 wt% or more and 60 wt% or less of the two fillers of the first spherical filler 21 and the second spherical filler 31. If the amount of the filler added is too small, the unevenness that can be formed decreases, and the gloss on the surface of the protective layer cannot be sufficiently reduced. Moreover, when there is too much addition amount of a filler, the mold release layer 20 and the protective layer 30 become weak, the problem that the adhesive force with the base material 10 falls, the holding power of a filler falls, and a filler falls off. Problems arise.

About the release layer 20, in order to improve the release property and filler retention, in addition to the binder, for the addition of a known curing agent represented by an isocyanate system, or to improve the release property A silicone-type or fluorine-based release agent may be added.
As the resin for forming the protective layer 30, any conventionally known resins having various durability and transparency can be used. For example, an acrylic resin, a cellulose resin, a polyvinyl acetal resin, a polyester resin, and the like can be given, but the invention is not limited thereto. In particular, an acrylic resin is preferable from the viewpoint of durability and transparency. In addition, the protective layer may have a plurality of layers in order to improve adhesion and durability. Furthermore, functional additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, a catalyst accelerator, a colorant, a gloss adjuster, a fluorescent brightener, and an antistatic agent can be added as necessary.

  When the protective layer 30 has a plurality of layers, an adhesive layer that comes into contact with the image receiving paper at the time of transfer is provided, but the binder resin used for this adhesive layer is not particularly limited except that it is a heat-meltable resin. Examples include, but are not limited to, styrene resins such as polystyrene and poly α-methylstyrene, acrylic resins such as polymethyl methacrylate and polyethyl acrylate, polyvinyl chloride, polyvinyl acetate, and vinyl chloride-vinyl acetate. Copolymers, vinyl resins such as polyvinyl butyral and polyvinyl acetal, polyester resins, polyamide resins, epoxy resins, polyurethane resins, petroleum resins, ionomers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers, etc. Synthetic resin, nitrocellulose, ethylcellulose, cellulose acetate Cellulose derivatives such as pionate, rosin, rosin-modified maleic resin, ester gum, polyisobutylene rubber, butyl rubber, styrene-butadiene rubber, butadiene-acrylonitrile rubber, derivatives of natural resin and synthetic rubber such as polychlorinated olefin, carnauba wax, Examples thereof include waxes such as paraffin wax.

  The thickness a of the release layer 20 is in the range of 0.5 μm or more and 6.0 μm or less. Further, the thickness b of the protective layer 30 is in the range of 0.5 μm to 30.0 μm and in the range of a or more. When the thickness of the release layer 20 is 0.5 μm or less, the holding power of the filler is lowered, and when it is 6.0 μm or more, the cohesive force of the film is lowered. Further, when the thickness of the protective layer 30 is 0.5 μm or less, the unevenness cannot be sufficiently formed, and the mat feeling cannot be raised, and when it is 30.0 μm or more, the cohesive strength of the film is lowered. This is because the transfer becomes unstable.

Below, the material used for each Example of this embodiment and each comparative example is shown. In addition, this embodiment is not limited to an Example.
<Preparation of substrate with heat-resistant slip layer>
As the base material, a polyethylene terephthalate film with a single-sided easy adhesion treatment of 4.5 μm is used, and the heat resistant slipping layer coating liquid having the following composition is applied to the non-easy adhesion treatment surface by a gravure coating method, so that the film thickness after drying is It apply | coated so that it might be set to 1.0 micrometer, and the base material with a heat resistant slipping layer was obtained by drying at 100 degreeC for 1 minute.

<Heat resistant slipping layer coating solution>
Silicon acrylate (US-350 manufactured by Toagosei Co., Ltd.): 50.0 parts by mass Methyl ethyl ketone: 50.0 parts by mass <Preparation of release layer coating solution>
A release layer base coating solution in which 10 parts by mass of acetylcellulose was dissolved in 90 parts by mass of methyl ethyl ketone was prepared, and a release layer coating solution was prepared by adding a filler to the base coating solution according to Table 1 below.

<Preparation of protective layer coating solution>
A protective layer base coating solution was prepared by dissolving 10 parts by mass of acrylic resin in 90 parts by mass of methyl ethyl ketone, and an acrylic filler was added to the base coating solution according to Table 2 below to prepare a protective layer coating solution.

(Creation of thermal transfer recording media)
A release layer coating solution (blend with undiluted solution or release layer coating solution-0) is applied to the surface of the easy-adhesion treated surface of the substrate with a heat resistant slipping layer by a gravure coating method, and the film thickness after drying is a predetermined film thickness. The release layer was formed by applying the coating composition and drying at 100 ° C. for 2 minutes. Subsequently, on the release layer, a protective layer coating solution (blend with undiluted solution or protective layer coating solution-0) is applied by a gravure coating method so that the film thickness after drying becomes a predetermined film thickness. By drying at 100 ° C. for 2 minutes, an adhesive layer was formed, and a thermal transfer recording medium was obtained.

<Preparation of transfer object>
A white foamed polyethylene terephthalate film of 188 μm is used as a base material, and an image-receiving layer coating solution having the following composition is applied to one surface thereof by a gravure coating method so that the film thickness after drying becomes 5.0 μm. As a result, a transfer object for thermal transfer was produced.
<Image-receiving layer coating solution>
Vinyl chloride-vinyl acetate-vinyl alcohol copolymer: 19.5 parts by weight Amino-modified silicone oil: 0.5 parts by weight Toluene: 40.0 parts by weight Methyl ethyl ketone: 40.0 parts by weight

<Preparation of prints>
The thermal transferable protective layer 40 of the thermal transfer recording medium was transferred onto the image receiving layer with an evaluation thermal printer.
<Characteristic evaluation>
Examples 1 to 23 and Comparative Examples 1 to 9 were evaluated for confirmation of the situation at the time of printing, gloss on the surface at 45 degrees, and whitening of the image. The evaluation results are shown in Table 3.

Glossiness: Measures glossiness at 60 ° incidence using a glossiness meter according to JIS8741.
A glossiness of 60 or less, where glare is reduced visually, is accepted.
Image clarity: Visually evaluate the reflection of fluorescent light. △ More than can be used.
◎: Fluorescent lamp is difficult to recognize ○: Contour is difficult to recognize
△: The outline is blurred ×: The outline is recognizable White turbidity ... Visually evaluate the turbidity caused by whitening of the image
◎ ⇒ ○ ⇒ △ ⇒x worsened in this order. △ More than can be used.

  As shown in Table 3, in the transfer protective layer comprising the release layer remaining on the substrate and the protective layer to be transferred, when the thickness of the release layer is a, the release layer has a particle size of 0.00. 1st spherical filler which exists in the range of 5a or more and 2a or less is included. Further, when the thickness of the protective layer is b, b is a or more, and the protective layer is the same resin system and spherical filler as the protective layer, and has a particle size of 0.5b or more and 2b or less and 2a or more. A second spherical filler within. Thus, it is understood that the white turbidity of the image is suppressed while the glossiness and image clarity are lowered. Further, by making the particle diameter of the second spherical filler added to the protective layer 1b or more, the image clarity could be lowered more effectively.

It was confirmed that the cloudiness can be further suppressed by setting the particle diameter of the first spherical filler of the release layer to 2 μm or more.
On the other hand, when the first spherical filler is not added to the release layer, the glossiness is not sufficiently lowered and a gloss of 60 or less cannot be secured, and when the second spherical filler is not added to the protective layer, the mapping is performed. It was confirmed that the sex did not drop sufficiently. It was also confirmed that the transferability was lowered when the release layer was applied thicker than 6 μm, or when the protective layer was applied thicker than 30 μm.

  The thermal transfer recording medium obtained by this embodiment can be used in a sublimation transfer type printer, and can realize high speed and high functionality of the printer. In addition, a matte tone having excellent design can be imparted to the surface of various images obtained by the thermal transfer system. Therefore, it can be widely used for cards such as digital camera self-print and identification cards, and is particularly suitable for an amusement output.

  As mentioned above, although embodiment of this invention was explained in full detail, actually, it is not restricted to said embodiment, Even if there is a change of the range which does not deviate from the summary of this invention, it is included in this invention.

DESCRIPTION OF SYMBOLS 10 ... Base material 20 ... Release layer 21 ... 1st spherical filler 30 ... Protective layer 31 ... 2nd spherical filler 40 ... Thermal transfer protective layer 50 ... Heat-resistant slipping layer

Claims (5)

In a thermal transfer recording medium having a heat transferable protective layer in which a heat-resistant slipping layer is provided on one surface of a substrate, and a release layer and a protective layer are sequentially laminated on at least a part of the other surface of the substrate,
When the thickness of the release layer is a and the thickness of the protective layer is b, b is a or more,
The release layer is a spherical filler and includes a first spherical filler having a particle size in the range of 0.5a to 2a,
The protective layer includes a second spherical filler that is the same resin-based spherical organic filler as the protective layer and has a particle size in the range of 0.5b to 2b and 2a or more. recoding media. The thickness a of the release layer is in the range of 0.5 μm to 6.0 μm,
2. The thermal transfer recording medium according to claim 1, wherein the thickness b of the protective layer is in the range of 0.5 μm or more and 30.0 μm or less and in the range of a or more.   The thermal transfer recording medium according to claim 1 or 2, wherein the particle diameter of the first spherical filler is 2 µm or more. The first spherical filler is an inorganic, organic, or mixed bead.
4. The thermal transfer recording medium according to claim 1, wherein the protective layer and the second spherical filler are acrylic resins. 5.   A thermal transfer printed matter, which is printed using the thermal transfer recording medium according to any one of claims 1 to 4.

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