JPS58116193A - Manufacture of heat transfer ink sheet - Google Patents

Abstract

PURPOSE:To obtain the titled ink sheet provided with a firmly bonded ink layer and having ink transfer efficiency by a method wherein an intermediate layer including a bond is formed on a substrate and the ink layer is formed on the intermediate layer after subjecting the intermediate layer to a heat treatment. CONSTITUTION:The intermediate layer including the bond is coated on the substrate 1 with a bar coater and after leaving the coating to dry naturally, the coated substrate is heated by a heater 4. Then an ink is coated on the intermediate layer with a bar coater to thereby form the ink layer 3. EFFECT:Since the intermediate layer (a bond layer) can be made thin, the heat transfer efficiency of the sheet is improved and a distinct printing can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a thermal transfer ink sheet, and more particularly to a method of manufacturing a thermal transfer ink sheet having an intermediate layer for the purpose of adhesion of the ink layer.

■ Background of the technology A thermal transfer printing device selectively heats an ink sheet impregnated with ink (using a print head) to cause the ink to scatter and adhere to recording paper to form a print pattern. In this case, Since the ink sheet is repeatedly subjected to heating and natural cooling operations, a strong one was required.

(f) Prior art and problems Figure 1 is a diagram showing the configuration of an ink sheet, where 1 indicates a base material;
2 is an intermediate layer for adhering the ink layer 3 and the base material 1;

Conventionally, the intermediate layer 2 was formed by mixing an adhesive with a solvent, applying the mixture to the base material 1, and then drying it naturally.

Then, ink is applied on this intermediate layer 2 to form an ink layer 3.
was forming.

However, since the intermediate layer 2 was formed by natural drying, the drying was insufficient and the solvent remained, and as the solvent evaporated, voids were created in the intermediate layer 2, resulting in a narrow contact area with the base material 1 and the ink layer 3. As a result, the adhesive force decreased, so it was necessary to increase the thickness of the intermediate layer by 20 layers.

For this reason, the heat supplied from the print head is not sufficiently supplied to the ink layer 3, resulting in a low printing rate. (a) It is an object of the present invention to provide a method for manufacturing an ink sheet that overcomes the above-mentioned conventional drawbacks and allows the intermediate layer of the ink sheet to be formed thinly.

(To) Structure of the Invention and Purpose According to IJiK from Hiromoto, thermal transfer includes the steps of forming an intermediate layer containing an adhesive on a base material, and then forming an ink layer on the intermediate layer. To provide a method for producing a thermal transfer ink sheet, characterized in that a step of heat-treating the intermediate layer is provided between the intermediate layer forming step and the ink layer forming step. (6) Embodiments of the Invention Preferred embodiments of the invention will now be described in detail with reference to the drawings.

Base material (capacitor paper 16 μm thick) 1 with 5 μm thick intermediate layer (boriaod resin and carbon black powder 4:5)
2' (mixed in a ball mill in a solvent of toluene:acetone (1:1) by weight) is coated with a bar coater.

Then, dry it naturally for 6 minutes and then heat it with heater 4) 100
℃ for 10 seconds. (Figure g2 (a)),
Next, ink (polyethylene glycol ($4000),
Dye (azo type) and carbon black powder in a ratio of 5:1:4 (
The ink layer 3 is formed by applying a mixture of toluene and acetone (by weight ratio) in a pool mill in a solvent of toluene:acetone (1:1) using a bar coater to a thickness of 20 μm. (Figure 2(b), with this ink sheet, the print head (thermal head) power is 0.
Thermal transfer was carried out under the conditions of 45W/dot 4m5ec, and an optical density fO,D of 1.2 could be obtained in nine places.

On the other hand, when the intermediate layer is only air-dried with a thickness of 10 μm as in the conventional case, 0. D value ti 1. According to this example, it was confirmed that the transfer efficiency was sufficiently improved, and there was no peeling of the ink layer 3 and the base material 1 as in the conventional case.

The adhesive force of adhesive layer 1 is stronger than conventional adhesive layer 2.
When drying naturally, pores are generated as the solvent in the adhesive layer 2 evaporates, and as a result, the contact area between the adhesive layer 2, the base material 1, and the ink layer becomes narrower, resulting in adhesive strength II! was decreasing, but this
In the case of Example I, even if the above-mentioned pores are generated due to the evaporation of the rounding solvent that softens the adhesive by heating during the formation of the adhesive layer 2, the pores disappear, so that the base material 1 and Since the contact area with the ink layer 3 is large, sufficient adhesive strength is ensured.

(2) As described in detail, according to the present invention, the intermediate layer (II bonding layer) of the ink sheet can be made thinner, so thermal transfer efficiency is improved and clear prints can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structure of an ink sheet, and FIG. 2 is an explanatory diagram of an embodiment of the present WA. 1 is the base material, 2.2' is the intermediate layer, 3Fi ink layer,
I Introduction

Claims (1)

[Claims] A method for producing a thermal transfer ink sheet comprising the steps of forming an intermediate layer containing an adhesive on a base material, and then forming an ink layer on the wrinkled intermediate layer, wherein the intermediate layer forming step and the ink layer are formed on the wrinkled intermediate layer. A method for producing a thermal transfer ink sheet, characterized in that a step of heating the intermediate layer is provided between the layer forming steps.