JPH05330247A - Dye thermal transfer receiving sheet - Google Patents

Abstract

PURPOSE:To provide a dye thermal transfer receiving sheet capable of being accurately mounted on a printer without mistaking the surface and rear thereof. CONSTITUTION:A dye thermal transfer receiving sheet is constituted by successively forming a surface resin coating layer and an image receiving layer on one surface of a sheetlike support and forming a rear resin coating layer on the other surface thereof and characterized by that the glossiness difference between the image receiving layer and the rear resin coating layer measured according to JIS Z9741 satisfies formula G1-G2 >=15 (wherein G1 is the glossiness of the image receiving layer and G2 is the glossiness of the rear resin coating layer).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a dye thermal transfer receiving sheet (hereinafter referred to as a receiving sheet). More specifically, the present invention relates to a receiving sheet that can be mounted on a dye thermal transfer printer without confusing the front surface and the back surface.

[0002]

2. Description of the Related Art In recent years, a thermal transfer type high-quality color hard copy, especially a dye thermal transfer type printer has been rapidly developed. In the dye thermal transfer printer, the sublimable dye layers of three colors (yellow, magenta, and cyan) are heated by continuously controlling the heating energy of the thermal head,
The transfer amount of the dye of each color is changed to enable a full-color image with density gradation.

As a conventional base material for a receiving sheet, as disclosed in JP-A-62-198497, USP4778782, etc., both surfaces of a core material such as paper mainly composed of cellulose are coated with heat such as polyolefin. Those obtained by laminating and laminating biaxially stretched films (synthetic paper) containing voids containing a plastic resin as a main component, and JP-A-2-106397, 2-3.
There is one in which a polyolefin resin is laminated on both sides of paper, as disclosed in No. 07786 and USP4774224. Since the front and back surfaces of these receiving sheet base materials are made of the same material, even if the image receiving layer is applied to the front surface, the whiteness is slightly different, and it is difficult to distinguish the front and back sides. .. For this reason, when the receiving sheet is attached to the printer installed indoors, the front and back are mistakenly attached to the paper feeding unit, the back surface of the receiving sheet and the ink sheet are fused, and the receiving sheet cannot be taken out from the printer. It disappeared, and there was inconvenience such as printer failure. In this case, in order to prevent fusion with the back surface, it is possible to apply a release agent such as silicon to the back surface side.
There is a demand for a better improvement method for this problem because of an increase in cost.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the difficulty of distinguishing between front and back when a synthetic paper laminating substrate or a paper substrate laminated on both sides with a polyolefin resin is used as a substrate for a receiving sheet. It is an object of the present invention to provide such a receiving sheet.

[0005]

The dye thermal transfer receiving sheet of the present invention comprises a sheet-shaped support, a surface side resin coating layer and an image-receiving layer formed on one surface of the sheet-shaped support in sequence, and the In a dye thermal transfer receiving sheet having a backside resin coating layer formed on one surface, the difference between the glossiness of the image receiving layer measured by the method of JIS Z 8741 and the glossiness of the backside resin coating layer is as follows. ) Is satisfied. | G1-G2 | ≧ 15 (1) (However, G1 indicates the glossiness of the image receiving layer, and G2 indicates the glossiness of the back side resin coating layer.)

The conventional backing sheet base material is made of the same material due to problems such as curling on the front and back. Therefore, even if an image receiving layer made of a saturated polyester resin or vinyl chloride resin is provided on the surface of the base material for the receiving sheet, the difference in whiteness and glossiness between the front and back of the receiving sheet is slight, and the receiving sheet is used indoors. It was difficult to identify the front and back. In the receiving sheet of the present invention, the difference in glossiness between the image receiving layer and the backside resin coating layer is set to 15% or more so that the front and back can be easily identified even in the room. In this case, if the difference in glossiness between the front surface side resin coating layer and the back surface side resin coating layer of the receiving sheet base material is 20% or more, the above formula (1) can be sufficiently satisfied. The front and back of the receiving sheet can be reliably identified. To provide a difference in glossiness between the image receiving layer and the backside resin coating layer,
It is possible to form the image receiving layer by cast coating, or to apply embossing to the image receiving layer or the backside resin coating layer. Further, in order to provide a difference in glossiness between the front surface side resin coating layer and the back surface side resin coating layer, use a cooling roll having a different surface shape when laminating the resin coating layer, or one side It is possible by a method such as embossing the resin coating layer.

[0007] As the sheet-like support used in the present invention, base paper mainly containing pulp is advantageously used. The pulp used for producing the base paper is not particularly limited,
For example, it is possible to use wood pulp obtained by subjecting hardwood or conifer to chemical treatment or mechanical treatment, used paper pulp, non-wood natural pulp such as hemp and cotton, synthetic pulp made from polyethylene, polypropylene, etc. it can. These pulps may be used alone or in combination of several kinds. Further, in addition to the above pulp, various fibers such as organic fibers such as acrylic fibers, rayon fibers, phenol fibers, polyamide fibers, and polyester fibers, inorganic fibers such as glass fibers, carbon fibers, and alumina fibers may be mixed. However, from the viewpoint of papermaking properties, base paper containing 50% by weight or more of pulp is preferable. Further, in the process of manufacturing the base paper, various retention aids, paper strength enhancers, sizing agents, fillers and the like can be appropriately selected and used, and further, dye, pH
A regulator, a slime control agent, an antifoaming agent and the like can be used as necessary. Also, size press and gate roll,
It is also possible to apply starch, polyvinyl alcohol, a surface sizing agent, a pigment or the like to the surface of the raw paper with a blade coater, an air knife coater or the like. The basis weight of the base paper is not particularly limited, but is preferably 60 to 250 g / m ² .

The resin forming the resin coating layers on the front surface side and the back surface side, which can be used in the present invention, is a thermoplastic resin capable of extrusion coating, and examples thereof include low density polyethylene, high density polyethylene, polypropylene, polybutene, and the like.
A linear low-density polyethylene which is a homopolymer such as polypentene or a copolymer of two or more olefins such as an ethylene / polypropylene copolymer or a copolymer of ethylene and an α-olefin, and a mixture thereof. The densities and melt indexes can be used alone or in combination. A white pigment is preferably added to the resin coating layer of the present invention in order to improve the whiteness of the receiving sheet. As the white pigment, titanium oxide, zinc oxide, talc, calcium carbonate or the like can be used. Further, resin metal salts such as stearic acid amide and zinc stearate, antioxidants such as hindered phenol, and pigments and dyes such as cobalt blue and ultramarine blue may be added.

In the receiving sheet of the present invention, an intermediate layer may be provided between the two layers in order to improve the adhesiveness between the surface side resin coating layer and the image receiving layer. As the resin that can be used to form the intermediate layer, various hydrophilic resins and hydrophobic resins can be used, and examples thereof include vinyl polymers such as polyvinyl alcohol and polyvinylpyrrolidone and their derivatives, polyacrylamide, and polydimethyl. Acrylamide, polyacrylic acid or a salt thereof, a polymer containing an acrylic group such as polyacrylic acid ester, a polymer containing a methacrylic group such as polymethacrylic acid, polymethacrylic acid ester, starch, sodium alginate, gum arabic,
Examples thereof include natural polymers or derivatives such as casein and carboxymethyl cellulose.

The receiving sheet of the present invention is prepared by providing an image receiving layer on the surface resin coating layer. The resin used in the image-receiving layer of the present invention is required to have good dyeing property of dye, high transfer speed, high image density, little discoloration due to heat, and good running property. .. Specifically, vinyl chloride resin such as thermoplastic saturated polyester resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl propionate copolymer is preferable, and other polycarbonate resin, polyvinyl acetal, polyamide, polyacrylic ester. Can also be used. In the image-receiving layer of the present invention, a resin cross-linking agent, a lubricant, a release agent, a pigment or the like may be added, if necessary, for the purpose of preventing fusion with the ink sheet due to heat during printing. Further, other additives such as pigments, fluorescent dyes, dyes such as blue and violet, ultraviolet absorbers, antioxidants and the like can be added as required. These additives may be mixed with the main component of the image receiving layer, or may be provided as a separate coating layer above or below the image receiving layer.

The thickness of the image receiving layer is 1 to 10 μm, preferably 2 to 6 μm. If the image receiving layer has a thickness of less than 1 μm, there are drawbacks such as a decrease in image density and sensitivity, or a decrease in gloss on the printed surface. On the other hand, when the thickness exceeds 10 μm, the effect is saturated, which is uneconomical and the strength of the image-receiving layer is lowered. In addition, a layer containing an antistatic agent may be provided on at least one surface of the receiving sheet in order to prevent static electricity from being generated during running of the receiving sheet in the printer, resulting in running trouble. A cationic hydrophilic polymer is advantageously used as the antistatic agent.

[0012]

The present invention will be described in more detail with reference to the following examples, which should not be construed as limiting the invention.

Examples 1 and 2 and Comparative Example 1 The resin composition shown in Table 1 was used for extrusion coating on both surfaces of a high-quality paper having a basis weight of 150 g / m ^{2 to form} a resin coating layer on the surface side having different glossinesses and A backside resin coating layer was provided. Then, after corona treatment is applied to the surface of the resin coating layer on the surface side, a coating composition for forming an image receiving layer having the composition shown below is used with a wire bar so that the solid content coating amount becomes 6 g / m ^2. An image receiving layer was formed by coating and drying to prepare a receiving sheet. The image receiving layer of each of the obtained receiving sheets,
Table 1 shows the glossinesses of the front surface side resin coating layer and the back surface side resin coating layer. The glossiness is measured by the method described in JIS Z 8741, Measurement Method 3, and the glossiness meter is GM.
-260 (made by Murakami Color Research Laboratory) was used.

The image-receiving layer forming coating composition Ingredient Blend weight polyester resin 100 parts by weight (trademark: Byron 200, manufactured by Toyobo Co., Ltd.) silicone oil 3 parts by weight (trademark: KF393, manufactured by Shin-Etsu Silicone Co.) Isocyanate 5 parts by weight (Trademark: Takenate D-110N, manufactured by Takeda Pharmaceutical Co., Ltd.) Toluene 300 parts by weight

Using 10 sheets of each of the obtained receiving sheets, the inside and outside of the room were judged by four testers. Table 2 shows the number of wrong sheets.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

Industrial Applicability The dye thermal transfer receiving sheet of the present invention can be accurately mounted on a printer without making a mistake in the front and back, and is extremely excellent in practical use.

Claims (1)

[Claims] 1. A dye in which a front surface side resin coating layer and an image receiving layer are sequentially formed on one surface of a sheet-shaped support, and a back surface side resin coating layer is formed on the other surface of the sheet-shaped support. In the thermal transfer receiving sheet, the difference between the glossiness of the image receiving layer measured by the method of JIS Z 8741 and the glossiness of the backside resin coating layer satisfies the relationship of the following formula (1). Thermal transfer receiving sheet. | G1-G2 | ≧ 15 (1) (However, G1 indicates the glossiness of the image receiving layer, and G2 indicates the glossiness of the back side resin coating layer.)