JP2006168234A - Thermal transfer sheet and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer sheet which can reduce the deposition of a foreign substance on a thermal head. <P>SOLUTION: This thermal transfer sheet has a thermal transfer coloring material layer 2 formed on one surface of a base material 1 and a heat-resistant lubricity layer 3 formed on the other surface. The heat-resistant lubricity layer 3 is not uniformly flat but uneven with 0.2 to 4.0 μm gap. The thermal transfer sheet is relatively run to a thermal head on the heat-resistant lubricity layer 3, and the coloring material of the thermal transfer coloring material layer 2 is heated by the thermal head to a high temperature level in a short time. However, by virtue of its unevenness, the heat-resistant lubricity layer 3 uptakes a foreign substance such as a melt or abrasion tailings derived from the layer 3 into the recessed part 31 and conveys them. Thus, the foreign substance responsible for causing a trouble by depositing on the thermal head can be removed to a minimum level. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal transfer sheet in which defective printing due to dust and dust generated when characters and images are transferred and recorded in a thermal transfer recording apparatus having a thermal head is prevented.

  A thermal transfer sheet used in a thermal transfer recording apparatus having a thermal head is provided with a heat transferable color material layer on one side of a base film, and is heated in an image form by a thermal head from the other side of the base. An image is formed by transferring the material, but since thermal printing is performed in a short time by the thermal head, in order to improve the running stability of the thermal transfer sheet and prevent the base material from being fused to the thermal head, etc. A heat-resistant slipping layer having heat resistance and slipperiness is provided on the side heated by the thermal head of the base film. Therefore, in order to prevent dust and dirt adhering to the heat-resistant slipping layer from adhering between the thermal head and the heat-resistant slipping layer and causing defects such as transfer omission in characters and images during transfer, Since the heat-resistant slipping layer contains thermoplastic resin and amorphous silica, there is a method to scrape off dust, dust, etc. adhering to the thermal head with a hard substance such as silica, and to adhere and remove it with the thermoplastic resin. It has been proposed (see, for example, Patent Document 1).

JP 11-263078 A (first page)

  However, the removal of dust and dirt scraped off as described above and the material of the melted heat-resistant slipping layer is not sufficient, and it adheres to the periphery of the thermal head. There is a problem in that, for example, defective printing may occur, and if a large amount of adhered matter adheres to the thermal head, it may cause problems such as white spots where the image is white.

  The present invention has been made to solve such a problem, and dust and dust generated by friction between the thermal head and the thermal transfer sheet, a material melted from the heat-resistant slipping layer, or a material scraped off is a thermal head. It is an object of the present invention to provide a thermal transfer sheet capable of fundamentally reducing the foreign matter adhering to the thermal head by preventing stagnation at the boundary of the thermal transfer sheet, and to propose a manufacturing method thereof.

  A first thermal transfer sheet according to the present invention comprises a base material, a thermal transfer color material layer provided on one surface of the base material, and a heat-resistant slipping layer provided on the other surface of the base material. A heat-sensitive transfer sheet that moves relative to the thermal head on the heat-resistant slipping layer and transfers the color material of the thermal transfer colorant layer to a transfer target. Has an unevenness of 0.2 to 4.0 μm.

  The first heat-sensitive transfer sheet of the present invention comprises a base material, a thermal transfer color material layer provided on one surface of the base material, and a heat-resistant slipping layer provided on the other surface of the base material. In the heat-sensitive transfer sheet that moves relative to the thermal head on the heat-resistant slipping layer and transfers the color material of the thermal transfer colorant layer to the transfer target, the surface of the heat-resistant slipping layer has a gap. It is characterized by having irregularities of 0.2 to 4.0 μm, and foreign substances adhering to the thermal head can be reduced.

Embodiment 1 FIG.
FIG. 1 is a plan view {FIG. 1 (a)} of the heat-sensitive transfer sheet according to Embodiment 1 of the present invention and a cross-sectional view taken along the line AA {FIG. 1 (b)}. The heat transfer color material layer 2 is provided on the surface, and the heat-resistant slip layer 3 is provided on the other surface of the substrate 1, and the surface of the heat-resistant slip layer 3 is not flat and has irregularities, Although the gap 33 between 31 and the convex portion 32 is 0.2 to 4.0 μm and is not shown, an antistatic layer may be provided between the heat resistant slipping layer 3 and the substrate 1.
FIG. 2 is an explanatory diagram for explaining the function and effect of the recess 31 of the heat-resistant slip layer 3 in the heat-sensitive transfer sheet according to the embodiment of the present invention.
That is, the thermal transfer sheet of the present embodiment is moved in the direction of the arrow in the drawing relative to the thermal head 5 on the heat resistant slipping layer 3 and heated to a high temperature in a short time by the thermal head 5. The color material of the thermal transfer color material layer 2 is transferred to the transfer body 6 to form an image. However, since the heat-resistant slip layer 3 has irregularities, foreign matters such as melts and wear from the heat-resistant slip layer 3 are formed. By taking 4 into the recess 31 and transporting it in the running direction, it is possible to reduce the above-mentioned foreign matter that causes adhesion to the thermal head and causes problems, thereby exhibiting cleaning properties while maintaining heat-resistant lubricity. Thus, the effect of reducing image defects can be obtained.
In addition, although the uneven | corrugated gap 33 is 0.2-4.0 micrometers, if it is less than 0.2 micrometers, the said effect will not be acquired, but if it exceeds 4.0 micrometers, the heat transfer efficiency of the heat resistant slipping layer 3 will fall.

FIG. 1 shows a case where a hole is provided on the surface of the heat resistant slipping layer so that the surface of the heat resistant slipping layer has irregularities, and the opening is a round hole. As shown in the figure, the hole is the entire surface of the heat resistant slipping layer. It is desirable that the thickness is uniformly provided because it has an effect of maintaining the in-plane uniformity of heat resistance and heat transfer efficiency.
The depth of the hole is preferably 0.2 to 4.0 [mu] m, and the opening of the hole is preferably sized to fit within 1 to 500 [mu] m square. If the size of the opening is less than 1 μm square, the amount that can be stored is small and the effect is not sufficient, and if it exceeds 500 μm square, the heat transfer efficiency of the heat resistant slipping layer 3 is unfavorable.
In the present embodiment, the opening is a round hole, but the opening may be rectangular or other shapes. When the opening is round, it is preferably provided at an interval of 0.1 to 10 times its diameter. When the interval is less than 0.1 times, the function of the heat resistant slipping layer is insufficient, and when it exceeds 10 times, foreign matter is not sufficiently stored.

Embodiment 2. FIG.
FIG. 3 is a plan view {FIG. 3 (a)} of the thermal transfer sheet according to the second embodiment of the present invention, and a cross-sectional view taken along the line AA thereof (FIG. 3 (b)). In the case where the surface of the heat-resistant slipping layer has irregularities by providing a plurality of grooves 34 on the surface of the heat-resistant slipping layer, the groove 34 crosses the running direction indicated by the arrow in the figure of the thermal transfer sheet (the figure shows In the same manner as in the first embodiment, the foreign matter 4 is taken into the groove, and the cleaning performance is exhibited while maintaining the heat-resistant sliding property in the same manner as in the first embodiment. Defects can be reduced.
In addition, the depth of the groove is 0.2 to 4.0 μm, the groove width is 1 to 500 μm, and the plurality of grooves are preferably provided at intervals of 0.1 to 10 times the groove width. . If the groove width is less than 1 μm, the amount that can be stored is small and the effect is not sufficient, and if it exceeds 500 μm, the heat transfer efficiency of the heat resistant slipping layer 3 is lowered, which is not preferable. When the interval is less than 0.1 times, the function of the heat resistant slipping layer is insufficient, and when it exceeds 10 times, foreign matter is not sufficiently stored.
Moreover, even if the groove 34 having the same width and depth as described above is provided in a curved manner, the same effect is obtained.

Embodiment 3 FIG.
FIG. 4 is a plan view {FIG. 4 (a)} of the thermal transfer sheet according to the third embodiment of the present invention, and a cross-sectional view taken along the line AA {FIG. 4 (b)}. 34 is provided with a convex portion 35 having an acute tip, and the surface shape of the heat-sensitive slipping layer on the cross section in the running direction of the heat-sensitive transfer sheet is wavy unevenness. In transfer using a sheet, if the foreign matter adheres to the thermal head, it is excellent in cleaning property that it is efficiently scraped off by the convex part, and it is possible to efficiently prevent white spots due to the attached matter and stick-like defective printing due to heat accumulation of the attached matter. The

Embodiment 4 FIG.
FIG. 5 is a plan view {FIG. 5 (a)} of the thermal transfer sheet according to the fourth embodiment of the present invention and a cross-sectional view taken along the line AA in FIG. 5 (b). Except that the heat-resistant slipping layer surface is provided with the columnar convex portions 36 so that the heat-resistant slipping layer surface has irregularities, the foreign matter adhering to the thermal head is efficiently scraped off by the convex portions 36. It is excellent in cleaning properties, and image defects can be reduced by taking in and transporting the foreign matter between the convex portions 36.
The contact area of the convex part 36 with the thermal head is a size that fits within 1 to 500 μm square, and when the convex part 36 is cylindrical, the convex part 36 is 0.1 to 0.1 mm in diameter of the bottom surface of the cylinder. It is desirable to provide them at 10 times the interval.
When the contact area is less than 1 μm square, the function of the heat-resistant slip layer is insufficient, and when it exceeds 500 μm, the cleaning effect is insufficient.
Further, if the interval between the cylindrical protrusions 36 is less than 0.1 times the diameter of the bottom surface of the cylinder, the effect of taking in foreign matter is insufficient, and if it exceeds 10 times, the cleaning effect is insufficient.

Embodiment 5. FIG.
FIG. 6 is an explanatory diagram of a method for producing a thermal transfer sheet according to Embodiment 5 of the present invention.
That is, using a coating apparatus equipped with a high-humidity environment maintaining apparatus or a water vapor blowing apparatus, the coating for a heat-resistant slipping layer containing a heat-resistant slipping layer material mainly composed of a polymer material in a high-humidity environment. While winding the base material 1 in the direction of the arrow in the figure, the working liquid 8 is applied to the base material 1 using a coating tool 7, dried and solidified to form a heat resistant slipping layer. The figure shows a case where the surface of the substrate 1 is applied in a high humidity environment by spraying the water vapor 6 onto the substrate 1 with a water vapor blowing device. At this time, self-organization of the polymer material in the heat-resistant slip layer material takes place using the minute water droplets generated in the evaporation process of the solvent under high humidity as a mold, so that the heat-resistant slip layer having regular holes can be easily formed. Can be formed.
The heat resistant slipping layer coating solution is obtained by dissolving or dispersing the following heat resistant slipping layer materials in a solvent such as cyclopentane, methanol, acetone, methyl ethyl ketone, toluene or xylene so as to suit the coating suitability. Thus, the coating liquid is applied to the following substrate by a conventional coating means such as a gravure coater, a roll coater, or a wire bar simultaneously with water vapor jetting, dried and solidified to form a film.

The thickness of the heat-resistant slip layer according to the present embodiment, i.e., coating weight, on a solids basis 0.1-3.0 mg / ^{m 2} C., more preferably 0.1 to 1.0 mg / ^{m 2} When the thickness is 5 mm, a heat resistant slipping layer having sufficient performance can be formed. When the amount is more than 3.0 mg / m ² , the heat conduction efficiency is reduced, and the amount of the foreign matter is increased, resulting in an increase in defects. When the amount is less than 0.1 mg / m ² , the heat-resistant slip property is lowered.

The heat-resistant slip layer material according to the present embodiment uses a heat-resistant resin as a binder resin, and acts as a thermal release agent or a lubricant. A slip agent, a surfactant, an inorganic particle, an organic particle, or a pigment. The one to which is added is used.
Examples of the binder resin used for the heat resistant slipping layer include cellulose resins such as cellulose acetate propionate, polyvinyl acetal resins such as polyvinyl butyral, acrylic resins, and polyester resins.
In addition, as a lubricant added in order to improve slipperiness to the said heat resistant slipping layer, conventionally well-known various lubricants, such as a phosphate ester type surfactant, can be used.

In addition, an inorganic or organic filler may be used for the heat-resistant slipping layer according to the present embodiment for processing suitability of the heat-sensitive transfer sheet, stabilization of printing running, and provision of thermal head cleaning properties.
Examples of the filler include those having a particle size and shape sufficient to form a finer uneven shape on the surface of the heat resistant slipping layer and less wear of the thermal head, such as talc, kaolin, clay, carbonic acid. Examples include inorganic fillers such as calcium, magnesium hydroxide, magnesium carbonate, magnesium oxide, precipitated barium sulfate or hydrotalcite silica, or organic fillers made of acrylic resin, benzoguanamine resin, silicone, tetrafluoroethylene, etc. It is preferable to have a thermal head cleaning property such as talc, kaolin, clay, etc. and a relatively low hardness.
Specifically, in the case of talc, a shot-type wear degree of 15 to 200 mg is preferable. When the wear degree is low, the thermal head is easily damaged, and when it is high, the thermal head protective layer is significantly worn.

  As the base material according to the present embodiment, for example, in addition to a polymer film such as a polyethylene terephthalate film having a thickness of about 0.5 to 50 μm, preferably about 3 to 10 μm, paper such as condenser paper and paraffin paper, A nonwoven fabric or a composite of paper or nonwoven fabric and resin is used.

In the case of a sublimation type thermal transfer sheet, a layer containing a sublimation dye is formed as the heat transferable color material layer according to the present embodiment formed on the other surface of the substrate, and the heat melting type thermal transfer is performed. In the case of a sheet, a heat-meltable heat-transferable color material layer colored with a pigment or the like is formed.
As the dye used for the sublimation-type thermal transfer color material layer, any dye conventionally used in known thermal transfer sheets can be used and is not particularly limited. As a binder resin for supporting the dye, Cellulose-based, polyvinyl acetal-based, acrylic-based, urethane-based, or polyester-based resins are preferable from the viewpoints of heat resistance, dye transferability, and the like.

  The heat transferable color material layer has a thickness of about 0.2 to 5.0 μm, preferably about 0.4 to 2.0 μm, and the sublimable dye in the heat transferable color material layer is a heat transferable color material. Suitably the amount is from 5 to 90% by weight, preferably from 10 to 70% by weight of the layer, and on one side of the substrate the additives and dyes as required for the dye and binder, for example, release. What added a type | mold agent, an inorganic fine particle, etc. can apply | coat and dry and can form.

  Any image receiving sheet can be used as a material to be transferred to form an image using the heat-sensitive transfer sheet of the present embodiment as long as the recording surface has dye acceptability for the dye. Good.

  In addition, after forming a flat film | membrane using the heat resistant slipping layer raw material in this Embodiment, the method of shaving a part of a heat resistant slipping layer, or the said heat resistant slipping layer raw material with the stamp which transferred the desired pattern The heat-resistant slipping layer having irregularities on the surface can also be easily obtained by transferring the material onto the substrate.

Example 1.
As a base material, a polyethylene terephthalate film with a thickness of 6 μm {product name: Lumirror, manufactured by Toray Industries, Inc.} is used. It applied so that water vapor | steam was sprayed using a spray nozzle so that it might become. The coating film was temporarily dried with a dryer, then dried in an oven at 100 ° C. for 2 minutes, further heat-aged and cured to form a heat-resistant slipping layer. Asperities as shown in FIG. 1 are formed on the surface of the heat-resistant slip layer, the gap is 0.5 μm, and it is confirmed by a shape measuring microscope that round holes having a diameter of 10 μm are formed at intervals of 2 μm. It was done.
<Composition of coating solution for heat resistant slipping layer>
Polyvinyl butyral resin {trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.} 3.6 parts by weight, reisocyanate {trade name: Pernoc D750-45, manufactured by Dainippon Ink & Chemicals, Inc.} 19.2 Parts by weight, 2.9 parts by weight of a phosphate ester surfactant {trade name: Prisurf A208S, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.}, phosphate ester surfactant {trade name: Phosphanol RD720, Toho Chemical Co., Ltd.} 0.3 parts by weight, talc {trade name: Y / X = 0.03 Nippon Talc Co., Ltd.} 0.2 parts by weight, methyl ethyl ketone 33.0 parts by weight, toluene 33.0 parts by weight

Next, on the surface of the substrate opposite to the surface provided with the heat-resistant slip layer, the following coating liquid for the heat-sensitive transfer color material layer is applied in a form in which each color is separately applied. A heat-sensitive transfer sheet was obtained.
<Coating liquid for thermal transfer color material layer>
For yellow: 10 parts of yellow dye, 10 parts of polyester resin, 40 parts of toluene, 40 parts of methyl ethyl ketone For magenta: 10 parts of magenta dye, 10 parts of polyester resin, 40 parts of toluene, 40 parts of methyl ethyl ketone For cyan: 10 parts of cyan dye, polyester resin 10 parts, 40 parts of toluene, 40 parts of methyl ethyl ketone

Comparative Example 1
In Example 1, a heat-sensitive transfer sheet was obtained in the same manner as in Example 1 except that the heat-resistant slipping layer coating solution was applied to form a heat-resistant slipping layer in a dry atmosphere. The surface of the heat-resistant slipping layer of the heat-sensitive transfer sheet was confirmed by a shape measuring microscope to have a substantially flat shape having irregularities of about 0.1 μm.

Example 2
A polyethylene terephthalate film having a thickness of 6 μm (trade name: Lumirror, manufactured by Toray Industries, Inc.) is used as a base material, and the following heat-resistant slipping layer coating liquid is perpendicular to the sheet conveying direction on one side. It applied using the stamp which cut the groove | channel in the direction, and formed the heat-resistant slipping layer with an unevenness | corrugation as shown in FIG. Furthermore, the following heat-sensitive transfer layer coating solution was applied to the other surface in a form in which each color was applied separately to obtain a heat-sensitive transfer sheet.
The film thickness of the convex part is about 0.6 μm, the film thickness of the concave part is about 0.2 μm, the gap of the unevenness is about 0.4 μm, the groove width is 20 μm, and the running direction of the thermal transfer sheet between the uneven parts It was confirmed by a shape measuring microscope that the interval in the cross section was 20 μm.
<Coating fluid for heat resistant slipping layer>
20 parts of acrylic resin, 2.6 parts of silicone oil, 0.2 part of silica, 35 parts of toluene, 35 parts of methyl ethyl ketone (coating liquid for thermal transfer color material layer)
For yellow: 10 parts of yellow dye, 10 parts of polyester resin, 40 parts of toluene, 40 parts of methyl ethyl ketone For magenta: 10 parts of magenta dye, 10 parts of polyester resin, 40 parts of toluene, 40 parts of methyl ethyl ketone For cyan: 10 parts of cyan dye, polyester resin 10 parts, 40 parts of toluene, 40 parts of methyl ethyl ketone

Comparative Example 2
Using the coating solution for heat resistant slipping layer of Example 2, as in Comparative Example 1, a heat resistant slipping layer was formed in a dry environment to obtain a heat-sensitive transfer sheet. The surface of the heat-resistant slipping layer of the heat-sensitive transfer sheet was confirmed by a shape measuring microscope to have a substantially flat shape having irregularities of about 0.1 μm.

  Using the heat-sensitive transfer sheets obtained in Examples 1 and 2 and Comparative Examples 1 and 2, the presence or absence of printing defects was evaluated. When black and white prints were continuously printed on an L-size image receiving sheet and evaluated by visually observing the presence or absence of printing defects in the 500th image receiving sheet, Comparative Example 1 and Comparative Example 2 were evaluated. However, in Example 1 and Example 2, no dust was found on the thermal head, and there was no printing defect.

It is the top view and sectional drawing of the thermal transfer sheet of Embodiment 1 of this invention. It is explanatory drawing explaining the effect by the recessed part of a heat-resistant slipping layer in the heat-sensitive transfer sheet of embodiment of this invention. It is the top view and sectional drawing of the heat-sensitive transfer sheet of Embodiment 2 of this invention. It is the top view and sectional drawing of the heat-sensitive transfer sheet of Embodiment 3 of this invention. It is the top view and sectional drawing of the heat-sensitive transfer sheet of Embodiment 4 of this invention. It is explanatory drawing of the manufacturing method of the thermal transfer sheet of Embodiment 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material, 2 thermal transfer color material layer, 3 heat resistant slipping layer, 31 recessed part, 32 convex part, 33 gap, 34 groove | channel (recessed part), 35 convex part, 36 convex part, 5 thermal head.

Claims (6)

A thermal transfer color material layer provided on one surface of the substrate; and a heat-resistant slip layer provided on the other surface of the substrate. In the heat-sensitive transfer sheet that travels relatively to the surface and transfers the color material of the thermal transfer color material layer to the transfer target, unevenness having a gap of 0.2 to 4.0 μm is formed on the surface of the heat-resistant slip layer. A heat-sensitive transfer sheet comprising: The surface of the heat-resistant slipping layer has irregularities by providing a hole in the surface of the heat-resistant slipping layer, and the opening of the hole has a size that fits within 1 to 500 μm square. Thermal transfer sheet. By providing a plurality of grooves on the surface of the heat resistant slipping layer, the surface of the heat resistant slipping layer has irregularities, the grooves intersect with the running direction of the thermal transfer sheet, the groove width is 1 to 500 μm, The thermal transfer sheet according to claim 1, wherein the gap is 0.1 to 10 times the groove width. The heat-sensitive transfer sheet according to claim 3, wherein the surface shape of the heat-sensitive slipping layer in the running direction of the heat-sensitive transfer sheet is wavy irregularities, and the wavy convex portions are acute angles. By providing columnar convex portions on the surface of the heat resistant slipping layer, the surface of the heat resistant slipping layer has irregularities, and the contact area of the convex portions with the thermal head is within a size of 1 to 500 μm square. The heat-sensitive transfer sheet according to claim 1. The method for producing a thermal transfer sheet according to claim 1, wherein a coating solution for a heat-resistant slipping layer containing a heat-resistant slipping layer raw material mainly composed of a polymer material is applied to a substrate in a high humidity environment. And a method for producing a heat-sensitive transfer sheet which forms a heat-resistant slipping layer by drying and solidifying.

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