JPH1024664A - Thermal transfer image protecting sheet, sublimating thermal transfer sheet, and printing matter with thermal transfer image protective layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect an image by preventing the ink comprising the image from eluting or translating even when the image comes into contact with volatile organic solvent and plasticizer. SOLUTION: In this thermal transfer type image protective sheet 10, an image protective layer 20 is formed by laminating a releasing layer 1, an organic solvent-resistant layer 2 and a bonding layer 3 to one another in the order named. This image protective layer is used for protecting an image, which is transferred to a photographic printing paper with a sublimation thermal transfer printer, on the photographic printing paper by transferring the image protective layer 20 with a thermal head to the image on the photographic printing paper in order to coveringly protect the image. The organic solvent-resistant layer 2 is mainly made of the crosslinked matter of hydrophilic butryral resin so as to prevent the ink in the image from eluting due to the contact of the image with the organic solvent or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type thermal transfer technique, and more particularly to a thermal transfer type image protection sheet, a sublimation type thermal transfer sheet, and a printed matter provided with a thermal transfer type image protection layer.

[0002]

2. Description of the Related Art In a sublimation type thermal transfer, ink on a thermal transfer ink sheet, that is, solid ink applied to a substrate at room temperature is transferred to a transfer paper (printing paper) by heating and vaporizing the ink with a thermal head. It is. In particular, in sublimation type color thermal transfer, three types of inks of yellow, magenta and cyan are used as the sublimable ink.

[0003]

However, the printed matter by such a sublimation type thermal transfer system (also called D2T2) loses its image when it comes in contact with a volatile organic solvent such as acetone or lower alcohol (the ink is dissolved). Out) had a drawback. Also, a material containing a plasticizer, for example,
When the sheet comes into contact with a soft polyvinyl chloride sheet or a plastic eraser, the image is transferred to these materials, and there is a problem that color transfer to these materials and color loss of a printed material occur.

Therefore, in order to prevent these problems, attempts have been made to transfer a layer for protecting the image after the image has been transferred to the receiving paper. However, the conventional image protective layer cannot prevent image elution due to contact with a solvent such as acetone. This is because the components of the image protective layer are dissolved.

Accordingly, an object of the present invention is to protect an image (ink layer) so that the ink forming the image does not elute or migrate even when the image comes into contact with a volatile organic solvent or a plasticizer. It is in. That is, the present invention provides (1)
A thermal transfer type image protection sheet provided with an image protection layer excellent in image protection function; (2) a sublimation type thermal transfer sheet provided with the image protection layer; and (3) a printed matter in which an image is protected by the image protection layer. Is to provide.

[0006]

A thermal transfer type image protection sheet according to the present invention is obtained by laminating a release layer, an organic solvent resistant layer and an adhesive layer (adhesive layer) on a sheet-like substrate in this order. An image protection sheet provided with a thermal transfer type image protection layer, wherein the organic solvent-resistant layer is mainly composed of a crosslinked product of a hydrophilic butyral resin (see FIG. 1). .

Further, the sublimation type thermal transfer sheet according to the present invention has a thermal transfer type image protection comprising a sublimation ink layer, a release layer, an organic solvent resistant layer and an adhesive layer laminated in this order on the surface of a substrate film. A sublimation-type thermal transfer sheet provided alternately in the longitudinal direction of the base film, wherein the organic solvent-resistant layer contains a crosslinked product of a hydrophilic butyral resin as a main component. (See FIGS. 1 and 2).

Further, the printed matter provided with the thermal transfer type image protective layer according to the present invention is a printed matter in which the image on the surface of the photographic paper transferred from the sublimation type thermal transfer sheet is covered with the image protective layer. The layer is characterized by having an organic solvent resistant layer containing a crosslinked product of a hydrophilic butyral resin as a main component.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 is a cross-sectional view showing a configuration of a thermal transfer type image protection sheet. The image protection sheet 10 is used to protect the image on the transfer paper after the image is transferred to the transfer paper (printing paper, transfer sheet) by a sublimation type thermal transfer printer. The image protection layer 20 is set on a printer and overlapped on the transfer paper, and
Is transferred by a thermal head to cover and protect the image.

In this image protection sheet 10, a sheet-like substrate having a back coat 12 (heat-resistant lubricating layer) on the back surface, for example, a base film 1 made of polyethylene terephthalate
On the surface of No. 1, the image protection layer 20 formed by laminating a release layer 1, an organic solvent resistant layer 2, and an adhesive layer 3 in this order is formed.

Embodiment 2 FIG. 2 is a plan view of a sublimation type thermal transfer sheet. This thermal transfer sheet 30 is of a so-called “dandara coating system”, and has a sublimable ink layer 40 on the surface of a base film 11 on which a back coat 12 is applied as shown in FIG.
Are yellow (Y) in the longitudinal direction of the thermal transfer sheet 30,
Magenta (M) and cyan (C) are applied in this order, and an image protection layer 20 having the same configuration as that of FIG. 1 is formed following cyan. In this case, the sublimable ink layers 40 and the image protection layers 20 are formed alternately in the longitudinal direction of the base film 11.

In printing (thermal transfer) using the thermal transfer sheet 30, an image is transferred onto a transfer paper by sequentially sublimating the three color inks of the ink layer 40 with a thermal head of a thermal transfer printer, and then heat of the thermal head is applied. To transfer the image protection layer 20 onto the image of the transfer receiving paper,
The image is covered and protected by the image protection layer 20. While the image protection sheet 10 of FIG. 1 is dedicated to image protection, the thermal transfer sheet 30 has both an image transfer function and an image protection function. Incidentally, instead of the thermal transfer sheet of the dandala coating method, yellow, magenta, cyan ink layers were provided in the longitudinal direction of the sheet and parallel to each other,
A so-called "streak coating" thermal transfer sheet can also be used.

Next, the structure of the image protection layer 20 will be described in detail. Release layer 1: (1) Function: adjacent organic solvent resistant layer 2 and adhesive layer 3
This is for smooth release when thermally transferring the image onto the image of the receiving paper. (2) Material: A mixture of a hydrophobic binder and a filler. The role of the hydrophobic binder is as follows: the organic solvent resistant layer 2 (hydrophilic)
The purpose of the present invention is to lower the affinity with the above, prevent mixing between the layers when forming the image protective layer 20, and provide releasability. As a material of the hydrophobic binder, a polyester resin or the like can be used. The role of the filler is to improve the sharpness of the transfer start portion and the transfer end portion (edge) of the image protection layer 20 during thermal transfer. As a material for the filler, a hydrophobic filler is preferable in consideration of dispersibility.

Organic solvent resistant layer 2: (1) Function: to protect images. The organic solvent resistant layer is provided with solvent resistance, so that the organic solvent is prevented from reaching the image surface. (2) Material: a material obtained by crosslinking a material obtained by dispersing a filler in a hydrophilic binder. The role of the hydrophilic binder is to provide solvent resistance. A hydrophilic resin is used as a material that is not attacked by organic solvents, and has mechanical strength by crosslinking. As the hydrophilic resin, a butyral resin (polyvinyl butyral resin) soluble in water and alcohol is suitable. As the hydrophilic binder, a polyvinyl alcohol resin can also be employed. As the cross-linking agent, glyoxal can be used when the hydrophilic resin is a butyral resin, and glyoxal can be used when the hydrophilic resin is a polyvinyl alcohol resin. The role of the filler is to improve the sharpness of the transfer start portion and the transfer end portion (edge) of the image protection layer 20 during thermal transfer. As a material of the filler, a hydrophilic filler is preferable in consideration of dispersibility, and specific examples include kaolin, clay, talc, silica, calcium carbonate, mica, alumina, and gypsum.

Adhesive layer 3: (1) Function: to thermally bond the image protective layer 20 released from the thermal transfer sheet to the surface of the transfer receiving paper (image receiving paper) during thermal transfer. (2) Material: A mixed dispersion of a thermoplastic binder and a filler. The role of the thermoplastic binder is to plasticize using the heat of the thermal head and to thermally bond to the surface of the paper to be transferred. Further, a boron compound is added in order to secure the adhesiveness with an adjacent layer. The role of the filler is the same as in the case of the release layer 1 and the organic solvent-resistant layer 2.
To improve the sharpness of the transfer start portion and the transfer end portion (edge). The filler material is preferably a hydrophobic filler in consideration of dispersibility.

[0016]

Next, the present invention will be described more specifically with reference to examples and comparative examples. [Preparation of Coating Solution for Forming Image Protective Layer] Coating Solution for Forming Release Layer: 10 parts by weight of Byron 200 manufactured by Toyobo Co., Ltd. 5 parts by weight of tetradodecyl ammonium-substituted smectite 5 parts by weight of toluene 45 parts by weight of methyl ethyl ketone 45 Parts by weight In this formulation, the polyester resin is the hydrophobic binder and smectite is the filler. The mixture of this formulation was dispersed by a sand mill to obtain a coating liquid for forming a release layer.

Coating solution for forming an organic solvent-resistant layer: Butyral resin KX-5 manufactured by Sekisui Chemical Co., Ltd. Solid content: 7.9% 75 parts by weight Smectite Smecton SA manufactured by Kunine Kogyo Co., Ltd. 3 parts by weight Isopropyl alcohol / Water = 4/6 mixture 75 parts by weight 15 parts by weight of a 40% aqueous glyoxal solution was added to a liquid obtained by dispersing the mixture having the above formulation by a sand mill to obtain a coating solution for forming an organic solvent resistant layer. In the above formulation, smectite is a filler and glyoxal is a crosslinking agent.

[0018] Coating solution for forming adhesive layer: ・ PVC vinyl chloride resin Denki Vinyl Co., Ltd., 10G parts by weight, 1000GK ・ Tetradodecyl ammonium substituted smectite, 3 parts by weight ・ Boron compound DLG-1100K, manufactured by Boron International Co., Ltd. (45% MEK solution) 7 parts by weight ・ Toluene 45 parts by weight ・ Methyl ethyl ketone 45 parts by weight In the above formulation, polyvinyl chloride resin is a thermoplastic binder, smectite is a filler, and boron compound is an adhesion promoter. The mixture having the above formulation was dispersed in a sand mill to obtain a coating solution for forming an adhesive layer.

[Preparation of Thermal Transfer Type Image Protecting Sheet] On the surface of a PET film (thickness: 6 μm) provided with a heat-resistant lubricating layer on the back surface, the coating liquid for forming a release layer and the formation of an organic solvent-resistant layer were formed in the following manner Transfer coating solution, and a coating solution for forming an adhesive layer in this order by laminating and coating, in this order, a thermal transfer type image protective sheet, that is, a thermal transfer sheet having a thermal transfer type image protective layer formed thereon (FIG.
). (1) After applying a coating solution for forming a release layer using a wire bar # 5, drying at 120 ° C. for 1 minute, and (2) applying a coating solution for forming an organic solvent resistant layer using a wire bar # 10. After coating, dry at 120 ° C for 1 minute. (3) Wire bar
After applying the adhesive layer forming coating liquid using 10, 12
Dry at 0 ° C for 1 minute.

[Transfer of Image Protective Layer] An UP-3000 made by Sony Corporation was used as a printer, and an ink sheet for UPC-3010 made by Sony Corporation was used as an ink sheet.
As the photographic paper, UPC-7040 photographic paper manufactured by Sony Corporation cut into a size of 100 mm x 140 mm was used. The ink sheet is a conventionally used sublimation type color thermal transfer sheet, in which a sublimable ink layer is applied in the order of yellow, magenta, and cyan on the surface of a base film having a heat-resistant lubricating layer on the back surface. is there.

The printed matter obtained by using the printer, the ink sheet and the printing paper, and the thermal transfer type image protection sheet having the same shape as the ink sheet are set in the printer. The image protection layer was heat-transferred over the entire photographic paper image. As a result, a glossy transparent image protection layer was transferred onto the photographic paper.

[Solvent resistance test]
The printed matter having the image protective layer transferred onto the photographic paper after image formation is hereinafter referred to as "printed matter of Example 1". The printed matter of Example 1 ". Further, a printed matter produced using the ink sheet UPC-3040 manufactured by Sony Corporation is referred to as a "printed matter of Comparative Example 2". In this print, a conventional transparent protective film is formed on the image surface. Three prints of each of the above three types of prints were prepared, and these were individually immersed one by one in various organic solvents to examine changes in images. The results are shown in [Table 1].

[0023]

[Table 1]

As is clear from Table 1, by transferring the thermal transfer type image protective layer according to the present invention onto a print, the resistance of the image to an organic solvent was greatly improved.

[0025]

As is apparent from the above description, the thermal transfer type image protection sheet and the sublimation type thermal transfer sheet according to the present invention have a thermal transfer layer having an organic solvent resistant layer mainly composed of a crosslinked product of a hydrophilic butyral resin. An image protection layer is provided, and the image protection layer is transferred onto an image of photographic paper by a thermal transfer printer to cover and protect the image. Therefore, according to the present invention, even when the image on the printing paper comes into contact with a volatile organic solvent or a plasticizer, the elution of the ink forming the image or migration (color loss or color transfer) does not occur. In addition, it is possible to prevent data tampering with an organic solvent (illegal modification) and the like.
For this reason, there is an effect that the information on the photographic paper can be stored in a clear state for a long time. Further, since the printed matter according to the present invention is obtained by covering and protecting the image on the printing paper with the image protection layer, there is an effect that this image can be stored as it is for a long period of time.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a thermal transfer type image protection sheet according to the present invention.

FIG. 2 is a plan view showing an embodiment of a sublimation type thermal transfer sheet according to the present invention.

[Explanation of symbols]

1 ... release layer, 2 ... organic solvent resistant layer, 3 ... adhesive layer, 1
0: heat transfer type image protection sheet, 11: base film, 12: back coat, 20: image protection layer, 30
... Sublimation type thermal transfer sheet, 40... Sublimable ink layer.

Claims (3)

[Claims] An image protection sheet provided with a thermal transfer type image protection layer formed by laminating a release layer, an organic solvent resistant layer and an adhesive layer in this order on the surface of a sheet-like substrate, A thermal transfer type image protection sheet characterized in that the solvent layer mainly comprises a crosslinked product of a hydrophilic butyral resin. 2. A sublimation ink layer, and a thermal transfer type image protection layer formed by laminating a release layer, an organic solvent resistant layer and an adhesive layer in this order on the surface of the substrate film, in the longitudinal direction of the substrate film. A sublimation type thermal transfer sheet, wherein the organic solvent-resistant layer contains a crosslinked product of a hydrophilic butyral resin as a main component. 3. A printed matter in which an image on a printing paper transferred from a sublimation type thermal transfer sheet is coated with an image protective layer, wherein the image protective layer is mainly composed of a cross-linked hydrophilic butyral resin. Printed matter provided with a thermal transfer type image protective layer, characterized by having a solvent layer.