JPH03159791A - thermal transfer ink sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] Regarding thermal transfer ink sheets used in thermal transfer recording using thermal heads applied to printers, facsimile machines, etc., the ink sheets are good even on plain paper such as commonly used high-quality paper. In order to provide a heat transfer ink sheet capable of recording halftones, a heat melt ink layer consisting of a coloring material, a low melting point wax material, and a filler is provided on a sheet base material via an intermediate adhesive layer, and A transparent porous resin layer and a transparent adhesive layer that is non-adhesive at room temperature and becomes adhesive when heated are formed on the ink layer in this order.
The present invention provides a halftone recording thermal transfer ink sheet characterized by having multiple layers.

[Industrial application field]

The present invention relates to a thermal transfer ink sheet used in thermal transfer recording using a thermal head applied to printers, facsimiles, etc.

Recently, in this type of thermal transfer recording, there has been a demand for good halftone recording even on plain paper such as commonly used high-quality paper at a low cost.

[Conventional technology]

The structure of a conventional thermal transfer ink sheet 20 for halftone recording is shown in FIG. For example, a dye made of Kayaset black as a coloring material and fatty acid amide wax and paraffin wax as low melting point wax materials are mixed on a sheet base material 2l made of a polyester film or the like via an intermediate adhesive layer 22 made of a polyester resin. Furthermore, as a filler, fine powder of carbon black 23 having excellent cohesiveness is dispersed and applied as an ink layer 24. A porous structure, a so-called stone wall structure, is formed in the heat-fusible ink layer 24 by a solid fine powder filler, and this porous space is partially filled with the ink. Such a thermal transfer ink sheet 20 is layered on a special paper, such as a coated paper with a smooth surface and good moisture absorption, with a corresponding heat-melting ink layer 24, and the sheet base material is By pressing a thermal head (not shown in FIG. 4) against the surface of the ink layer 21 and selectively heating the heat-melting ink layer 24 with the heating element of the thermal head, the melted ink components are transferred to the surface of the ink layer. It oozes out an appropriate amount and records good halftones on the recording paper.

[Problem to be solved by the invention]

However, the conventional thermal transfer ink sheet 2 as described above
Even if transfer recording is performed by overlaying plain paper such as commonly used high-quality paper on top of 0, there is a problem that good halftone recording cannot be obtained because the surface of these plain papers is not very smooth. Ta.

Therefore, an object of the present invention is to provide a thermal transfer ink sheet that can perform good halftone recording even on ordinary paper such as high-quality paper that is commonly used.

[Means to solve the problem]

In order to solve such problems, in the present invention, as shown in FIG. A layer 4 was provided, and a double layer was further provided on the ink layer in this order: a transparent porous resin layer 15 and a transparent adhesive layer 16 that was non-adhesive at room temperature and became adhesive when heated. A halftone recording thermal transfer ink sheet is provided.

[For production]

As described above, in the present invention, the transparent porous resin layer 15 and the transparent adhesive layer 16 are provided in this order on the ink layer surface of the conventional stone wall structure type ink sheet. When the thermal transfer ink sheet 10 of the present invention is used to transfer onto the recording paper 6, which is plain paper, the adhesive layer l6 is first transferred.
A double layer of the porous resin layer 15 and the porous resin layer 15 are simultaneously deposited on the paper surface, and at the same time, ink corresponding to the printing energy amount of the thermal head 4 is transferred onto the porous resin layer 15 almost simultaneously. Since the vehicle in the ink is absorbed by the voids in the porous resin 15, the molten ink is firmly held on the surface of the porous resin 15, similar to when it is transferred to coated paper with a smooth surface. Good halftone recording is achieved.

〔Example〕

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

FIG. 1 is a sectional view of a main part of a thermal transfer ink sheet according to the present invention. In the figure, 11 is a sheet base material made of polyethylene tereftate film (PET) with a thickness of, for example, 5 μm, and 12 is an adhesive made of polyamide resin or polyester resin, etc., on the sheet base material 11.
This is an intermediate adhesive layer coated to a thickness of μm. Further, on the intermediate adhesive layer 12, Kayaset black (
(manufactured by Nippon Kayaku Co., Ltd.), paraffin wax (manufactured by Nikko Fine Chemicals), and finely powdered carbon black with excellent cohesion (manufactured by Nippon Kayaku Co., Ltd.) in a weight ratio of 11.5:1. After the mixture at a ratio of 2:2 is sufficiently separated with acetone, it is coated to a thickness of, for example, 9 μm using a bar coater coating device, and dried using a drier to form a heat-fusible ink layer 14.

Furthermore, in the present invention, a transparent porous resin layer 15 and a transparent adhesive layer 16 as shown in FIG. 1 are provided on this hot-melt resin layer 14. However, the resin in the porous resin layer 15 is made porous by providing a large number of small pinholes as shown in FIG. This is what I did. Also,
The adhesive layer 16 is made of a highly transparent resin adhesive such as inbutylene-maleic anhydride copolymer resin, which is non-tacky at room temperature but becomes sticky when heated.

As shown in FIG. 3, a thermal transfer ink sheet 10 of the present invention and plain paper 6 such as high-quality paper are stacked with the ink sheet 10 side facing outward, and pressed against the platen roller 5, and placed on the thermal head 4. When a plurality of heat generating parts (not shown) of the ink layer 14 are selectively caused to generate heat based on the printed information, first the ink layer 14
At the same time as the ink inside melts, the transparent adhesive layer l6
has a sticky surface and transfers onto the plain paper 6, which is the recording paper, together with the porous resin layer 15. At this time, a certain amount of the ink vehicle is sucked into the capillary tube in the porous resin 15, so
The molten ink is firmly held on the porous resin layer 15, and good halftone recording is performed in the same manner as when it is transferred to coated paper with a smooth surface.

〔Effect of the invention〕

As described above, according to the present invention, while the conventional stone wall structure ink sheet 20 having only a heat-melting ink layer and an intermediate adhesive layer was able to perform good halftone recording only on special paper, this According to the thermal transfer ink sheet 10 of the invention, halftone recording can be performed even on plain paper 6 such as high-quality paper whose surface is not smooth, and gradation recording can be performed at low cost.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a half-tone thermal transfer ink sheet according to the present invention, FIG. 2 is a cross-sectional view of the main part of the porous resin layer in FIG. 1, and FIG. FIG. 4 is a sectional view of a conventional halftone thermal transfer ink sheet, showing the state in which transfer recording is performed in an overlapping manner. 4... Thermal head, 5... Platen, 6... Plain paper, 11... Sheet base material, 2... Intermediate adhesive layer, 3... Carbon (filler) 4... Ink layer, 5... porous resin layer, 6... adhesive layer, 7... pinhole.

Claims (1)

[Claims] 1. A hot melt ink layer 14 consisting of a coloring material, a low melting point wax material, and a filler is provided on the sheet base material 11 via an intermediate adhesive layer 12, and a transparent porous resin layer 15 is further provided on the ink layer.
and a transparent adhesive layer 16 that is non-adhesive at room temperature and becomes adhesive when heated.