JPH0781243A - Thermal transfer recording medium - Google Patents

Abstract

(57) [Summary] [Object] The present invention does not require an adhesive layer to a transfer medium in a thermal transfer recording medium, and easily forms an image on the transfer medium made of various different materials. It is an object of the present invention to provide a thermal transfer recording medium which is capable of providing a sufficient abrasion resistance to a formed image. In a thermal transfer recording medium comprising a substrate 10 and an ink layer 13 laminated thereon, the ink layer 13 comprises a coloring pigment or a dye, a softening point of 70 to 120 ° C., and a melt viscosity of 100 to 250 cps / 200 ° C. And a wax having a melting point of 60 to 120 ° C., which is a thermal transfer recording medium 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording medium for forming an image on plain paper (uncoated paper) regardless of the coated paper or the like which has been conventionally used as a transfer medium.
More specifically, the present invention relates to a thermal transfer recording medium capable of forming a good image even on various materials to be transferred having different materials and capable of imparting sufficient abrasion resistance to the obtained image.

[0002]

2. Description of the Related Art Conventionally, there has been known a thermal transfer recording method for forming an image by thermally transferring an ink layer formed on a base material to a transfer target by using a thermal head or a thermal pen as a heating means for transfer. However, this method is widely used because it has the advantages that noise during image formation is low, color images can be formed relatively easily, and that the image forming apparatus itself is compact and its cost is low. By the way, in recent years, various image-receiving devices have been used with the spread of image forming apparatuses and the diversification of applications, and the use of uncoated paper called plain paper instead of conventional coated paper is increasing. Since it is cheaper than coated paper in terms of cost, it is not limited to coated paper as a social need,
There is a demand for a thermal transfer recording medium capable of forming an image on plain paper.

As such a thermal transfer recording medium for forming an image on plain paper, a resin / wax mixed type thermal transfer recording medium in which an adhesive layer made of an ethylene-vinyl acetate copolymer or the like is provided on an ink layer, or A wax type thermal transfer recording medium is known as one having no adhesive layer.

[0004]

However, in the case of forming an image on a conventional thermal transfer recording medium for forming an image on plain paper, a transfer target made of an ethylene-vinyl acetate copolymer or the like is contained in the thermal transfer recording medium. A resin / wax mixed type thermal transfer recording medium having an adhesive layer formed with or a wax type thermal transfer recording medium must be used. In the former case, the cost is negative, and in the latter case, it is transferred. There has been a problem that the abrasion resistance of the image is not sufficient.

Therefore, the present invention is intended to solve the above-mentioned problems of the prior art, and does not require an adhesive layer to the transfer target in the thermal transfer recording medium, and is composed of various different materials. An object of the present invention is to provide a thermal transfer recording medium capable of easily forming an image on a transfer body and imparting sufficient abrasion resistance to the formed image.

[0006]

The inventor of the present invention can achieve the above object by mixing cyclopentadiene and waxes as a binder used in an ink layer of a thermal transfer recording medium for image formation. They found out and completed this invention.

That is, according to the present invention, in a thermal transfer recording medium for image formation comprising a substrate and an ink layer laminated thereon, the ink layer comprises a coloring pigment or a dye and a softening point of 7.
0 ~ 120 ℃, and melt viscosity 100 ~ 250cps / 2
Cyclopentadiene resin of 00 ° C and melting point of 60-12
The thermal transfer recording medium is characterized by containing waxes at 0 ° C.

The present invention will be described below in detail with reference to the drawings.

FIG. 1 is a side view of a thermal transfer recording medium according to a preferred embodiment of the present invention. As shown in the figure, the medium of the present invention has a structure in which a base material 10, a release layer 12 and an ink layer 13 are sequentially laminated. The base material 10 used in the present invention functions as a support for the thermal transfer recording medium. As such a base material 10, a base material that has been conventionally used as a base material of a thermal recording medium can be used, and for example, a polyester film, a polyolefin film, a condenser paper or the like can be preferably used. The thickness of the base material 10 is not particularly limited and can be appropriately selected as needed.

In order to form a clear transfer image, the releasing layer 12 is melted by a heat signal from a heating means such as a thermal head at the time of image formation, and the ink layer 13 can be easily heat-transferred to a transfer object. It is a layer for doing so. The release layer 12 can be omitted. Such a release layer 12 can be formed in the same manner as a release layer that has been conventionally used. For example, wax such as carnauba wax, rice wax, candelilla wax, montan wax, paraffin wax, or a heat-melting resin such as polyethylene glycol wax can be used. The thickness of the release layer 12 can be appropriately selected according to the conditions such as the material used, the physical properties of the ink, and the heating temperature, but generally the thickness is about 0.5 to 2.0 μm. preferable.

The ink layer 13 is a layer for forming an image by thermal transfer onto a transfer target. In the present invention, a coloring pigment or dye which has been conventionally used and a melting point within a specific range as a binder component are further added. Is a mixture of cyclopentadiene resin having a melt viscosity and waxes having a melting point in a specific range. By using such a binder component, even when plain paper is used as the transferred material, it is not necessary to provide an adhesive layer with the transferred material in the thermal transfer medium, and transfer materials made of various different materials can be easily used. An image can be formed on. Moreover, sufficient abrasion resistance can be imparted to the obtained image.

The cyclopentadiene resin which is an essential component of the ink layer 13 has a softening point of 70 to 120 ° C.
It is preferably 80 to 105 ° C. When the softening point of this cyclopentadiene resin is lower than 70 ° C., a phenomenon of thickening of characters is observed in a transferred image, resulting in deterioration of image quality. On the other hand, when the temperature exceeds 120 ° C., the transfer energy becomes insufficient, and a fading phenomenon appears in the transferred image, resulting in deterioration of image quality. Furthermore, the melt viscosity at this time is 1
00-250 cps / 200 ° C, preferably 100-22
Use 0 cps / 200 ° C.

When the melt viscosity of the cyclopentadiene resin is less than 100 cps / 200 ° C., a crush phenomenon occurs in the transferred image, and when it exceeds 250 cps / 200 ° C., the transfer image is blurred due to insufficient penetration of the transferred material. The phenomenon becomes visible and the image quality is deteriorated. Further, the molecular weight distribution M of such a cyclopentadiene resin is
w / Mn is preferably 1.2 to 2.0.

The waxes which are an essential component of the ink layer 13 have a melting point of 60 to 120 ° C., preferably 7
The thing of 0-100 degreeC is used. The melting point of waxes is 6
When the temperature is lower than 0 ° C, a blocking phenomenon occurs and the storage stability of the thermal transfer recording medium is deteriorated. When the temperature exceeds 120 ° C., the transfer energy becomes insufficient, and a fading phenomenon is observed in the transferred image, resulting in deterioration of image quality.

Further, the mixing ratio of the coloring pigment or dye of the ink layer 13, the cyclopentadiene resin and the waxes varies depending on their kinds, but generally the coloring substance is 5 to 35% by weight, and preferably 10 to 10. 25 wt%, cyclopentadiene resin 5 to 70 wt%, preferably 10 to 50 wt%, waxes 20 to 8
It is 5% by weight, preferably 40 to 75% by weight. In addition,
The thickness of the ink layer 13 is not particularly limited and can be appropriately selected as necessary, but generally a thickness of about 1 to 4 μm is preferable.

The thermal transfer recording medium of the present invention can be manufactured by a conventional method. For example, a release layer-forming composition is first coated on a substrate such as a polyester film by a gravure method to form a release layer 12. It can be manufactured by forming the composition, and further coating the composition for forming an ink layer thereon by a gravure method.

[0017]

In the thermal transfer recording medium of the present invention, a cyclopentadiene resin having a specific melting point range and a melt viscosity range and a wax are mixed and used as a binder of an ink layer, and therefore, a transfer material made of various different materials is used. It is possible to easily transfer the heat to the surface of the sheet to form an image.

[0018]

EXAMPLES The present invention will be specifically described below with reference to examples.

<Example 1> A release layer-forming composition having the following composition was coated on a transparent polyethylene terephthalate film having a thickness of 4.5 μm to a thickness of 1.5 μm using a gravure coater, A mold release layer was formed by drying at 110 ° C. Release layer forming composition Component name Amount used (parts by weight) Carnauba wax 25.5 Micro wax 8.5 Paraffin wax 1.5 Ethylene-vinyl acetate copolymer 4.5 (manufactured by Konishi Co., Ltd.) Water 60.0

On the release layer 12 described above, an ink layer-forming composition having the following composition is further applied to a thickness of 2.5 μm using a hot melt gravure coater to form an ink layer 13. As a result, a thermal transfer recording medium 15 for image formation was obtained. Composition for forming ink layer Component name Amount used (parts by weight) Carbon black 13.0 (Colombyan Carbon Co., Ltd.) Cyclopentadiene resin 14.5 (Mitsui Petrochemical Co., Ltd.) Carnauba wax 60.0 (Toyo Petro) Paraffin wax 10.0 (manufactured by Konishi Co., Ltd.) Rice wax 2.5 (manufactured by Konishi Co., Ltd.)

The resulting thermal transfer recording medium was evaluated as described below. Beck smoothness of 300
Transfer material A (plain paper: manufactured by Kanzaki Paper Co., Ltd.) of sec / 10 cc and transfer material B of Beck smoothness of 150 sec / 10 cc
(Plain paper: manufactured by Kanzaki Paper Co., Ltd.) and Beck smoothness of 200
For a transfer target C (coated paper: manufactured by Kanzaki Paper Co., Ltd.) of sec / 10 cc, a thermal transfer recording medium and a printer (B60
4: manufactured by Tokyo Denki Co., Ltd.) was used to thermally transfer the barcode pattern. PCS value [= {(white bar reflectance)-(black bar reflectance)) / (white bar when the obtained image was identified by a barcode reader (Autoscan-6000: manufactured by EM Co., Ltd.) Reflectivity)] was measured. The results are shown in Table 1.

[0022]

[Table 1] In this case, the higher the PCS value, the better the barcode image.

Further, the images formed on the transferred materials A, B, and C were subjected to a 1000-gakushin test under a load of 1000 g, and the abrasion resistance thereof was judged by the PCS value. In this case, when the abrasion resistance is not sufficient, the black bar portion peels off and the PCS value decreases, and when the decrease is remarkable, it becomes impossible to judge the image. Also, the transferred materials A, B, C
On the other hand, with respect to an image obtained by performing thermal transfer of a solid pattern using a thermal transfer recording medium and a printer (Okura printing simulator: manufactured by Okura Electric Co., Ltd.), the Max density and the printing energy at that time were measured by a reflection densitometer (Macbeth RD918). Was measured. The results are shown in Table 2.

[0024]

[Table 2] In this case, the higher the reflection density, the better the image, and the lower the printing energy at that time, the higher the sensitivity.

As is clear from Tables 1 and 2, the thermal transfer recording medium of this example was able to form an image practically no problem on any transferred material. It was also found that the abrasion resistance was sufficient.

Comparative Example 1 Example 1 was repeated except that the following composition was used as the ink layer forming composition.
A thermal transfer recording medium was manufactured in the same manner as in. Composition for forming ink layer Component name Amount used (parts by weight) Carbon black 13.0 (manufactured by Colombian Carbon Co., Ltd.) Polyester resin 14.5 (manufactured by Unitika Ltd.) Carnauba wax 60.0 (manufactured by Toyo Petrolite Co., Ltd.) ) Paraffin wax 10.0 (made by Konishi Co., Ltd.) Rice wax 2.5 (made by Konishi Co., Ltd.)

Regarding the obtained thermal transfer recording medium, thermal transfer of a bar code pattern and a solid pattern was performed on the transfer targets A, B and C in the same manner as in Example 1. The results are shown in Tables 1 and 2. As can be seen from Tables 1 and 2, the thermal transfer recording medium of this comparative example can form a generally good image on the transferred materials A and C, but forms a satisfactory image on the transferred material B. I couldn't. Regarding the abrasion resistance, almost the same results as in Example 1 were obtained.

Comparative Example 2 Example 1 was repeated except that the following composition was used as the ink layer forming composition.
A thermal transfer recording medium was manufactured in the same manner as in. Ink layer forming composition Component name Amount used (parts by weight) Carbon black 13.0 (Colombyan Carbon Co., Ltd.) Carnauba wax 65.0 (Toyo Petrolite Co., Ltd.) Paraffin wax 18.0 (Konishi Co., Ltd.) ) Rice wax 4.0 (manufactured by Konishi Co., Ltd.)

Regarding the obtained thermal transfer recording medium, thermal transfer of a bar code pattern and a solid pattern was performed on the transfer targets A, B and C in the same manner as in Example 1. The results are shown in Tables 1 and 2. As can be seen from Tables 1 and 2, the thermal transfer recording medium of this comparative example was able to form a substantially good image on the transfer targets A, B, and C. However, after the abrasion resistance test, the PCS value could not be read, indicating that the abrasion resistance was insufficient.

[0030]

According to the present invention, it is possible to easily form an image on a transfer medium made of various different materials without requiring an adhesive layer with the transfer medium in the thermal transfer recording medium. Moreover, an excellent thermal transfer recording medium was obtained in which sufficient abrasion resistance could be imparted to the formed image.

[Brief description of drawings]

FIG. 1 is a side view showing an example of a thermal transfer recording medium in an example of the present invention.

[Explanation of symbols]

 10 ... Base material 12 ... Release layer 13 ... Ink layer 15 ... Thermal transfer recording medium

Front Page Continuation (72) Inventor Masato Yoshida 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (1)

[Claims] 1. A thermal transfer recording medium comprising a substrate and an ink layer laminated on the substrate, wherein the ink layer comprises a coloring pigment or dye, a softening point of 70 to 120 ° C. and a melt viscosity of 100.
A thermal transfer recording medium comprising a cyclopentadiene resin of 250 cps / 200 ° C. and waxes having a melting point of 60 to 120 ° C.