JPS59165695A - Transfer material for thermal recording - Google Patents

Abstract

PURPOSE:To provide a transfer material capable of recording with high image quality while uniformly transferring a coloring material and suitable for use in high-speed recording by an electronic device, wherein a coloring material layer is provided on a film base consisting of a polyimide. CONSTITUTION:The coloring material layer 3 is provided on the film base (preferably having a thickness of 5-40mum and an irregularity in the thickness of within 2mum) 2 consisting of a composition comprising a polyimide as a main constituent. USE:Heat of a thermal head 1 is transmitted to the coloring material layer 3 through the base 2, and the coloring material is transferred to an image-receiving body 4 through sublimation or melting. A full color image can be also obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat-sensitive recording transfer body used for recording in which a coloring material is transferred by applying heat, and in particular to an electronic device such as a thermal head or a laser beam. It can be used for high-speed recording.

2 Base S. Structure of Conventional Example and its Problems Hitherto, full-color thermal recording transfer bodies containing coloring materials, which can be applied to high-speed recording, have been widely used. However, in many of these transfer bodies, for example, the color material is transferred unevenly in the areas corresponding to the dots of the thermal head.
There is a problem that the image quality is disturbed, and it is known that this is caused by non-uniformity such as uneven thickness or surface waviness of the base of the transfer body. In order to eliminate these problems, attempts have been made to use film-like substrates, but good recording is often not obtained due to melting and deformation due to heat.

OBJECTS OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording transfer member that can uniformly transfer coloring materials and provide recordings with good image quality.

Structure of the Invention The heat-sensitive recording transfer member of the present invention is characterized in that a coloring material layer is provided on a film base made of polyimide or a composition mainly composed of polyimide. Here, the color 3 page material includes color formers in addition to colored pigments and dyes.

These film substrates have very little uneven thickness and surface waviness, and do not melt or deform due to heat. Therefore, good recording is achieved by uniform transfer of the coloring material.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1st
The figure is a sectional view of an example of recording by a thermal head. Heat from the thermal head 1 is conducted to a coloring material layer 3 through a film base 2, and the coloring material is transferred to an image receptor 4 by sublimation or melting. In addition to the coloring material, the coloring material layer 3 may also contain a binder for binding the coloring material, an extender pigment, and the like.

Further, when the thickness of the film base 2 is in the range of 5 μm to 4 μm, heat is smoothly conducted to the coloring material, and good results are obtained. In particular, a thickness in the range of 1011rrL to 20 μm provides sufficient recording density and mechanical strength. Furthermore, especially when the thickness unevenness of the film base is within 2 μm, the recorded image quality is good. In particular, when the thickness unevenness is within 1 μm, extremely excellent image quality is provided. Here, the thickness and thickness unevenness of the film substrate were defined as follows. That is, the size is 148i+gX
A 20 x m long straight section 5 shown in Fig. 2 of the five central and four corner sections of a 210 ml film substrate 2 was measured with a digital length measuring device using a spherical probe with a diameter of 3.6 mm and a load of 80 g. The thickness was measured at intervals of .25i+m, the average value thereof was defined as the thickness, and the difference between the maximum value and the minimum value was defined as the unevenness of the thickness.

In addition, there are compositions in which polyimide is blended with inorganic fillers having heat resistance and good thermal conductivity such as alumina, titanium oxide, and graphite, and compositions in which a thin metal film is attached to the surface 6 facing the thermal head 1. It is also excellent as a film substrate.

The present invention will be explained in more detail below using specific examples.

A solution prepared by dissolving 2 parts by weight of the dye represented by the following structural formula A and 4 parts by weight of polysulfone in 150 parts by weight of methylene chloride was wrapped around 5 pages of 12.6 μm thick polyimide film with 3 mil stainless steel wire. Cast with a wire bar and use as a transfer material for thermal recording. The thickness unevenness of the polyimide film was 1 μm or less.

Using these transfer bodies, a recorded image was drawn using a thermal head on a receiver made of polypropylene synthetic paper coated with activated clay under the following recording conditions.

Linear density of main scanning and sub-scanning = 4 dots/ho recording power
: o, yW/dot head heating time
:2 to sms As a result, a homogeneous magenta dye image having pixels corresponding to dots was obtained at each heating time.

It should be noted that with a transfer material (comparative example) similarly made using capacitor paper with a thickness of 12 μm and a thickness unevenness of 3 μm or more, it was difficult to obtain pixels corresponding to dots in the halftone region of 3 to 6 mB, and the image quality deteriorated. Page 6 Sj of disorder is causing it. In FIGS. 3 and 4, solid lines show typical examples of pixel microscopy at a heating time of 4 m1i in this example and comparative example, respectively. The broken line in the $4 diagram is a pixel corresponding to a dot.

Not only the dye sublimation type transfer body of the above example, but also the melt transfer type transfer body using the film base of the present invention gave recordings with good image quality.

Effects of the Invention As described above, the heat-sensitive recording transfer member of the present invention provides recording with good image quality. Full-color images can also be obtained using three types of thermal recording transfer bodies that provide cyan, magenta, and yellow recorded images.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a transfer body for thermal recording according to an embodiment of the present invention, FIG. 2 is a plan view showing the film base of the transfer body and the measurement points of its thickness, and FIGS. 3 and 4 are the same. There are 7 pages of diagrams showing examples of pixel microscopy provided by a transfer body for thermal recording and a transfer body of a comparative example. 2...Film base, 3...Coloring material layer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure! Figure 2

Claims (3)

[Claims] (1) A transfer material for heat-sensitive recording, characterized in that a coloring material layer is provided on a film base made of polyimide or a composition mainly composed of polyimide. (2) The transfer body for thermal recording according to claim 1, wherein the thickness of the film base is in the range of 5 to 40 μm. (3) The heat-sensitive recording transfer member according to claim 1 or 2, wherein the thickness unevenness of the film base is within 2 μm.