JP2008188969A - Thermal transfer recording medium - Google Patents

Abstract

The present invention provides a thermal transfer recording medium that is durable and self-cleaning for a thermal head and is maintenance-free.
In a heat-sensitive transfer recording medium (1) in which a heat-sensitive transfer layer (12) is provided on one surface of a base film (11) and a heat-resistant lubricant layer (13) is provided on the other surface, the heat-resistant lubricant layer is provided. (13) is mainly composed of a thermoplastic resin, a reaction product of a thermoplastic resin and a polyvalent isocyanate, or a radical reaction product triggered by ultraviolet rays or an electron beam, and a phosphate compound and alkanesulfonate sodium as lubricants. It contains a salt compound, and further contains a filler having a Mohs hardness of 4 or less and an average particle size of 2 μm or less.
[Selection] Figure 1

Description

  The present invention relates to a thermal transfer recording medium, and more particularly to a backcoat layer of a thermal transfer recording medium, and more particularly to a thermal transfer recording medium that can contribute to improved durability and maintenance-free thermal heads.

  Conventionally, when printing an output print of a computer, word processor, facsimile or the like by a thermal transfer method, a recording material layer made of heat-melting ink or a recording material layer containing a sublimation dye is provided on one surface of a base film. A thermal transfer recording medium is used.

  Printing and image formation using such a thermal transfer recording medium are performed by superimposing a recording material layer and a transfer medium and heating the substrate film from the back with a thermal head.

  However, when a plastic film is used as the base film, the thermal head adheres to the base film during printing and the peeling from the thermal head and the slip property are impaired, or the base film breaks. There is a fear.

  For this reason, a back coat layer is formed on the back surface of the base film. As the back coat layer, a combination of a thermoplastic resin and a phosphate ester (for example, see Patent Document 1), or a combination of a binder resin and an anionic surfactant having a sodium sulfonate group (for example, a patent document). 2) and the like have been proposed.

The said prior art document is shown.
JP 61-95989 A

JP-A-6-99670

  However, the former is mainly intended to prevent sticking, and the latter is primarily intended to prevent thermal head wear and discharge breakdown, and there has been no thermal-sensitive transfer recording medium that is self-cleaning and is maintenance-free.

  The present invention has been made to solve the above-described problems relating to the thermal transfer recording medium, and it is an object of the present invention to provide a thermal transfer recording medium that is self-cleaning as well as the durability of a thermal head and is maintenance-free. And

  The invention according to claim 1 of the present invention is the heat-sensitive transfer recording medium in which the heat-sensitive transfer layer is provided on one surface of the base film and the heat-resistant slip layer is provided on the other surface. Contains a reaction product of a plastic resin, or a thermoplastic resin and a polyvalent isocyanate, or a radical reaction product triggered by ultraviolet rays or an electron beam as a main component, and contains a phosphate ester compound and an alkane sulfonate sodium salt compound as a lubricant. The thermal transfer recording medium further comprises a filler having a Mohs hardness of 4 or less and an average particle diameter of 2 μm or less.

Thus, according to the invention of claim 1, the heat-resistant slipping layer is mainly composed of a thermoplastic resin, a reaction product of a thermoplastic resin and a polyvalent isocyanate, or a radical reaction product triggered by ultraviolet rays or an electron beam. As a lubricant, it contains a phosphate ester compound and an alkane sulfonate sodium salt compound, and further contains a filler with a Mohs hardness of 4 or less and an average particle diameter of 2 μm or less, thus preventing thermal head wear. In addition, a thermal transfer recording medium having self-cleaning properties can be obtained.
Further, since the surfactant is made of an alkane sulfonate sodium salt type, the durability of the thermal head is further improved from the electrical viewpoint.

  The invention according to claim 2 is the thermal transfer recording medium according to claim 1, wherein the heat-resistant slipping layer has a filler content of 3 to 25% by mass.

  The invention of claim 3 is the thermal transfer recording medium according to claim 1 or 2, wherein the filler in the heat-resistant slipping layer is an inorganic mineral.

  According to a fourth aspect of the present invention, in the first, second or third aspect of the invention, the thermal transfer layer is a thermal sublimation transfer layer comprising a heat sublimable dye and a binder. It is.

  According to a fifth aspect of the present invention, in the first, second or third aspect of the present invention, the thermal transfer layer is a thermal melt transfer layer comprising a dye or / and a pigment and a binder. It is a medium.

  As described above, by using the thermal transfer recording medium of the present invention, the thermal conduction unevenness from the thermal head is eliminated, and the thermal transfer recording medium sensitive to the thermal conduction unevenness can be applied. If there is uneven heat conduction, it becomes rough and appears in the print.

The present invention will be described in detail below based on one embodiment.
For example, as shown in FIG. 1, the thermal transfer recording medium (1) of the present invention has a thermal transfer layer (12) on one side of a substrate film (11) and a heat-resistant lubricant layer (13 on the other side). ), And a thermal head (not shown) is in contact with the heat-resistant lubricant layer (13).

  Examples of the base film (11) include various base films conventionally used for thermal transfer recording media. From the viewpoint of heat resistance, changes in mechanical properties, cost, etc., particularly polyethylene terephthalate film is used. It can be used suitably.

  The heat-sensitive transfer layer (12) is a recording layer for characters, pictures, etc., and is a heat-sensitive melting type recording layer composed of dyes, pigments, dyes and pigments, binders, or the like, or a heat-sensitive layer composed of heat sublimation dyes and binders. Any of the sublimation type recording layers may be used. Each is composed of a colorant and a binder, and various additives can be added as necessary.

  As the colorant, among organic or inorganic dyes or pigments, those having a color density required as a recording material and not discoloring or fading due to light, heat, temperature or the like are preferable. In addition to cyan, magenta, yellow, black, and the like, various colorants can be used as the colorant.

  Examples of the binder include a type mainly composed of wax and a type mainly composed of butyral resin. In any type, various additives can be added as necessary.

  The heat resistant lubricant layer (13) imparts heat resistance, slip property, self-cleaning property, etc. to the surface of the base film (11) that contacts the thermal head. It contains a reaction product of isocyanate or a radical reaction product triggered by ultraviolet rays or an electron beam as a main component, and contains a phosphate ester compound and an alkane sulfonate sodium salt compound as a lubricant, and further has a Mohs hardness of 4 or less and an average. It contains a filler having a particle size of 2 μm or less.

  The thermoplastic resin used in the heat-resistant lubricant layer is preferably a butyral resin, the polyvalent isocyanate is preferably tolylene diisocyanate, and the filler is calcium carbonate (Mohs hardness 3), mica (Mohs hardness 2.8), gypsum (Mohs). Hardness 2), talc (Mohs's hardness 1) and the like are mentioned, but the most preferred filler is talc.

  As a method for forming the heat-sensitive transfer layer (12) and the heat-resistant lubricant layer (13) on the base film (11), a known coating method such as a gravure coating method may be used.

Next, the present invention will be described in more detail with reference to examples.
First, a polyethylene terephthalate film having a thickness of 4.5 μm was prepared as a base film (11). Moreover, the coating solution which consists of the following compounding ratio was produced as [the coating liquid for thermal sublimation transfer layer formation] used for formation of a thermal transfer layer (12).

Magenta dye 20 parts Butyral resin 15 parts Polyester resin 5 parts Toluene 30 parts Methyl ethyl ketone 30 parts Further, a coating solution having the following blending ratio was prepared as [thermosensitive transfer layer forming coating solution].

Magenta pigment 10 parts Epoxy resin 20 parts Carnauba wax 10 parts Toluene 30 parts Methyl ethyl ketone 30 parts

On one surface of the prepared base film (11), [Coating liquid-1 for forming a heat resistant slipping layer] according to the following formulation was applied by a gravure coating method so that the dry thickness was 0.8 μm.
[Coating solution-1 for forming a heat resistant slipping layer]
Butyral resin 5.0 parts Phosphate ester compound 0.8 parts Alkanesulfonate sodium salt compound 0.2 part Polyethylene wax (Mohs hardness 0.4, average particle size 1.8 μm) 3.0 parts Tolylene diisocyanate 0 parts Toluene 44.0 parts Methyl ethyl ketone 45.0 parts The filler content is about 27%.
Next, the prepared [thermal sublimation transfer layer forming coating solution] was applied to the other surface of the base film so as to have a dry thickness of 1.0 μm by the gravure coating method. A recording medium was produced.

On one surface of the prepared base film (11), [Coating fluid-2 for forming a heat resistant slipping layer] according to the following formulation was applied by a gravure coating method so that the dry thickness was 0.6 μm.
[Coating solution-2 for forming a heat resistant slipping layer]
Butyral resin 5.0 parts Phosphate ester compound 0.8 parts Alkanesulfonate sodium salt compound 0.2 parts Talc (Mohs hardness 1 average particle size 1.0 μm) 1.0 part Tolylene diisocyanate 2.0 parts Toluene 45 0.0 part Methyl ethyl ketone 46.0 parts The filler content is about 11%.
Next, the prepared [thermosensitive transfer layer forming coating solution] was applied to the other surface of the base film so as to have a dry thickness of 1.0 μm by the gravure coating method. A recording medium was produced.

On one surface of the prepared base film (11), [Coating liquid-3 for forming a heat resistant slipping layer] according to the following formulation was applied by a gravure coating method so that the dry thickness was 0.8 μm.
[Coating liquid-3 for forming a heat resistant slipping layer]
Butyral resin 5.0 parts Phosphate ester compound 1.0 part Polyethylene wax
(Mohs hardness 0.4 average particle size 3.0 μm) 3.0 parts Tolylene diisocyanate 2.0 parts Toluene 44.0 parts Methyl ethyl ketone 45.0 parts The filler content is about 27%.
Next, the prepared [thermal sublimation transfer layer forming coating solution] was applied to the other surface of the base film so as to have a dry thickness of 1.0 μm by the gravure coating method. A recording medium was produced.

On one surface of the prepared base film (11), [Coating liquid for forming a heat resistant slipping layer-4] according to the following formulation was applied by a gravure coating method so that the dry thickness was 0.8 μm.
[Coating liquid for forming heat resistant slipping layer-4]
Butyral resin 5.0 parts Phosphate compound 0.8 parts Alkane sulfonate sodium salt compound 0.2 parts Polyethylene wax
(Mohs hardness 0.4 average particle size 3.0 μm) 3.0 parts Tolylene diisocyanate 2.0 parts Toluene 44.0 parts Methyl ethyl ketone 45.0 parts The filler content is about 27%.
Next, the prepared [thermal sublimation transfer layer forming coating solution] was applied to the other surface of the base film so as to have a dry thickness of 1.0 μm by the gravure coating method. A recording medium was produced.

On one side of the prepared base film (11), [Coating liquid for forming a heat resistant slipping layer-5] according to the following formulation was applied by a gravure coating method so that the dry thickness was 0.8 μm.
[Coating liquid for forming heat resistant slipping layer-5]
Butyral resin 5.0 parts Phosphate ester compound 0.8 parts Alkane sulfonate sodium salt compound 0.2 parts Silica (Mohs hardness 7 average particle size 1.8 μm) 3.0 parts Tolylene diisocyanate 2.0 parts Toluene 44 0.0 part methyl ethyl ketone 45.0 parts The filler content is about 27%.
Next, the prepared [thermal sublimation transfer layer forming coating solution] was applied to the other surface of the base film so as to have a dry thickness of 1.0 μm by the gravure coating method. A recording medium was produced.

On one surface of the prepared base film (11), [Coating liquid for forming a heat-resistant slipping layer-6] according to the following formulation was applied by a gravure coating method so that the dry thickness was 0.6 μm.
[Coating liquid for forming heat resistant slipping layer-6]
Butyral resin 5.0 parts Phosphoric acid ester compound 0.8 part Alkanesulfonate sodium salt compound 0.2 part Silica (Mohs hardness 7 average particle size 1.4 μm) 1.0 part Tolylene diisocyanate 2.0 part Toluene 45 0.0 part Methyl ethyl ketone 46.0 parts The filler content is about 11%.
Next, the prepared [thermally melted transfer layer forming coating solution] was applied to the other surface of the base film so as to have a dry thickness of 1.0 μm by a gravure coating method. A recording medium was produced.

  Two types of thermal transfer recording media obtained in this manner (Examples 1 to 2) and four types of comparative examples (Examples 3 to 6, total 6 types) were transferred to 8 inch / s. A 10 km transfer test was carried out at a speed of 5 mm, and the state of the thermal head and the photographic paper after the test was visually observed, and the results are shown in Table 1. The thermal head was not cleaned at all during the transfer test.

1 is a schematic cross-sectional explanatory view of a thermal transfer recording medium of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Thermal transfer storage medium 11 ... Base film 12 ... Thermal transfer layer 13 ... Heat-resistant lubricant layer

Claims (5)

In the thermal transfer recording medium in which the thermal transfer layer is provided on one side of the base film and the heat resistant slipping layer is provided on the other side,
The heat-resistant slipping layer is mainly composed of a thermoplastic resin, a reaction product of a thermoplastic resin and a polyvalent isocyanate, or a radical reaction product triggered by ultraviolet rays or an electron beam, and as a lubricant, a phosphate ester compound and an alkane. A thermal transfer recording medium comprising a phonate sodium salt compound, further comprising a filler having a Mohs hardness of 4 or less and an average particle diameter of 2 μm or less.   The heat-sensitive transfer recording medium according to claim 1, wherein the filler content in the heat-resistant slipping layer is 3 to 25% by mass.   The thermal transfer recording medium according to claim 1, wherein the filler in the heat resistant slipping layer is made of an inorganic mineral.   4. The thermal transfer recording medium according to claim 1, wherein the thermal transfer layer is a thermal sublimation transfer layer comprising a heat sublimable dye and a binder. 5.   The thermal transfer recording medium according to any one of claims 1 to 3, wherein the thermal transfer layer is a thermal melt transfer layer composed of a dye or / and a pigment and a binder.

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