JPH02229065A - Thermal transfer recording method - Google Patents

Abstract

PURPOSE:To enable plain paper to be used as recording paper and to reduce consumption of a thermal transfer sheet by a method wherein a thermal transfer ink sheet which has a peeling layer on a film base and which has a thermal spreading ink layer thereon is used, and traveling speed of the thermal transfer ink sheet is made specific number times the traveling speed of the recording paper. CONSTITUTION:A thermal transfer ink sheet 5 is prepared by successively laminating a peeling layer 2, and an ink layer 3 having spreading property in thermal recording on one side surface of a film base 1. The thermal transfer ink sheet 5 drawn out from a delivery reel 6 is wound by a speed VI on a winding reel 9 via a delivery roller 7, a head 13, and a winding roller 8. Recording paper 10 is fixed to a drum 11 with a clamp 12, is rotated at a speed VP, comes in contact with the thermal transfer ink sheet 5 at a position of the head 13, and ink is transferred following a signal 14 of a head driver TPS 14 to form an image. VP and VI travel by specific speeds and their ratio is made to be 1.1. Thereby, consumption of the thermal transfer ink sheet can be comparatively reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thermal transfer recording method, particularly to a method capable of thermal transfer onto plain paper.

[Prior Art] Conventionally, problems with thermal transfer recording methods include that the number of times a thermal transfer sheet can be used repeatedly is small, and that special smooth paper is required as a recording paper in order to produce clear images. There were things to do.

In order to increase the number of times the thermal transfer sheet can be used repeatedly, by running the thermal transfer sheet, which has a porous network structure impregnated with hot melt ink, at a speed lower than the traveling speed of the recording paper, the amount of thermal transfer sheet used per time can be increased. A method has been proposed to reduce this (Japanese Unexamined Patent Publication No. 129196/1983).

In addition, a thermal transfer sheet has been proposed that is equipped with a heat-softening ink layer and a release layer and can be thermally transferred to recording paper with a low surface smoothness (Imaging Electronics Engineers of Japan National Conference No. 1, 1985).
, 13).

By the way, when the thermal transfer sheet in which the porous network structure is impregnated with hot-melt ink is used at a running speed different from that of the recording paper, the following problems occur.

■ Friction caused by the difference in relative speed between the ink film and the recording paper causes background smudges in non-image areas.

■ When the black rate of the recording section is high, especially when there is only one solid image, the ink film and recording paper do not separate properly, resulting in uneven running and uneven images.

In addition, when a medium for recording paper (hereinafter referred to as rough paper) with a low surface smoothness is run at a speed different from that of the recording paper, the ink originally transferred to the protrusions on the rough paper is transferred to the non-contact ink. Because it is a so-called bridge transfer type ink (for example, a resin-based ink such as ethylene-vinyl acetate copolymer), which carries along the ink by the strong cohesive force of the ink white,
Due to the speed difference between the ink film and the recording paper, (1) unevenness occurred in ink transfer, resulting in the disadvantage that solid images in particular became uneven;

[Problems to be Solved by the Invention] The present invention is intended to allow the use of plain paper as recording paper and to reduce the consumption amount of thermal transfer sheets.

[Means for Solving the Problems] The structure of the present invention for solving the above problems includes (1) using a thermal transfer ink sheet having a release layer on a film base and a hot-rollable ink layer thereon; The running speed of this thermal transfer ink sheet is l/n (1,
, l≦n) times, and (2) the heat-sensitive transfer recording method according to claim (1), wherein the spreadable ink layer contains an amide-based component.

The above-mentioned hot-spreadable ink is an ink that is easily stretched due to shear stress when heated, and when the ink heated by the thermal head is transferred to the recording paper, the top surface of the ink is Although the speed (vl) changes, the lower surface of the ink changes to the traveling speed (Vp) of the recording paper, so shearing stress is generated, and the ink is stretched and uniformly coated on the recording paper.

To specifically explain the method of the present invention with reference to the drawings, as shown in FIG.
A thermal transfer ink sheet was prepared in which ink layers 3 having ductility during thermal recording were sequentially laminated, and the running speed of the recording paper (V
p) and the running speed (Vl) of the thermal transfer ink sheet (
This is a method of recording so that Vp/V+-n) is 1.1 or more.

Note that it is preferable that the thermal transfer ink sheet has a heat-resistant layer 4 on the opposite side to the ink layer.

FIG. 2 shows a drawing of an embodiment of the method of the invention.

The thermal transfer ink sheet 5 fed out from the feeding reel 6 has a speed of 1, feeding roller 7, head 13,
It passes through a take-up roller 8 and is wound onto a take-up reel 9.

The recording paper IO is fixed to the drum 11 by a clamp 12, rotates at a speed vP, comes into contact with the thermal transfer ink sheet 5 at the head 13, and is driven by a head driver T S P 1 .
Ink is transferred according to the signal No. 4 to form an image.

The consumption of the thermal transfer ink sheet can be relatively reduced by running the above-mentioned inks (1) and (1) at a predetermined speed so that the ratio thereof is 1.1.

Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples.

Note that the amounts (parts) of each component described in the Examples are parts by weight.

Example 1 Approximately 1 mm thick on one side of a 6 μ thick PET film base
A 1 μm thick acrylic cured resin heat-resistant layer was provided, and on the opposite side, a 1 μm thick release layer was formed with the following composition.

Composition of release layer Paraffin wax (m, p, 60°C) 10 parts of 91 ethylene-vinyl acetate copolymer (vinyl acetate content 25%, softening point 90°C) A thermal transfer ink sheet was prepared by providing an ink layer.

Composition of the ink layer Carbon black 10 parts Low melting point polyamide resin (m, p, about 85°C) 60 parts Ester wax (m, p, 70°C) 30 parts Using this ink sheet, ink sheet with the apparatus shown in Fig. 2. Feed speed 3mm/sec, paper feed speed 9mm/sec
c, that is, n=VP/V,=3, and when recording was first performed, the density (OD) of the solid image was 1.10 and the background l'I
O: Good recording was obtained, with the character images being sharp and without trailing.

Similarly, when recording was performed with n=7 (by changing the ink sheet feed while keeping the paper feed speed constant), the OD shown in the graph in Figure 3 was obtained, and when n=5 or less, the OD was 1.0.
As above, an OD of 0.80 was obtained with n=7 (Fig. 3 ■)
. (Character print quality is sufficient even at OD=0.80) Example 2 On one side of the same film base as in Example 1, a release layer having a thickness of about 1 μm and having the following composition was provided.

Composition of release layer Polyvinyl alcohol 50 parts Sodium dodecylbenzenesulfonate 50 parts An ink layer having the following composition was provided on the release layer to a thickness of about 6 μM to prepare a thermal transfer ink sheet.

Composition of ink layer Carbon black 15 parts Oleic acid amide (m, p, 75°C) 70 parts Ethylene-vinyl acetate copolymer (vinyl acetate content 25%, softening point 80°C) 15 parts This ink sheet was used as an example. When the test was conducted under the same conditions as in No. 1, as shown by the curve ■ in Fig. 3, n = 4 and 0. D: An image of 1.0 or higher was obtained, and this was a good quality image with no background smear, sharpness, and no trailing.

Comparative Example 1 A porous network layer made of vinyl chloride-vinyl acetate copolymer was formed on the same PET film base as in Example 1 (see JP-A-59129196).
A thermal transfer ink sheet was prepared by containing 70% of the ink having the same composition as in Example 1 and making the total thickness of this layer 10 μm.

A test was conducted using this thermal transfer ink sheet under the same conditions as in the above example, and the results showed that the conveyance of the ink sheet was poor, and only uneven images with low OD were obtained as shown in ■ in Figure 3. Ta.

Comparative Example 2 The same ink sheet as Comparative Example 1 was produced except that the ink in the ink sheet of Comparative Example 1 was replaced with an ink having the composition shown below, which allows the same ink sheet to be used multiple times by constant speed recording.

Ink composition 5OT-BLACK-5 (Hodogaya Chemical dye) 20 parts Carnauba wax 40 parts Ester wax 20 parts Lanolin oil
20 parts The test method was the same as in the above Examples and Comparative Examples. As shown in (■) in FIG. 3, the OD had a sufficient density up to n=3, but background smearing occurred and the image area was unclear with trailing.

Comparative Example 3 A thermal transfer ink sheet having the following configuration as described in the research presentation of the Institute of Image Electronics Engineers, as exemplified in the prior art section, was produced.

Composition of release layer (2 μm thick) Paraffin wax 90% ethylene-vinyl acetate copolymer 10% Composition of ink layer (4 μm thick) Carbon black 20% ethylene-vinyl acetate copolymer 80% Test method is the above example , was the same as the comparative example.

As shown in ■ in Figure 3, up to n=2, the solid areas of the image were mostly filled in and 1.0≦OD, but when 3≦n, the solid areas were poorly filled and white areas appeared. occurred and decreased to OD≦0.8.

[Effects of the Invention] As explained above, according to the thermal transfer recording method of the present invention, a sharp image with high density can be obtained, and V p /
Even if V + is increased, a good image with sufficiently filled solid areas can be formed.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing the structure of an example of a thermal transfer ink sheet used in the method of the present invention, ]0 FIG. 2 is an explanatory diagram of an apparatus for carrying out the method of the present invention, and FIG. It is a graph showing the relationship between the number of times of use and image density (OD) of thermal transfer ink sheets of Examples and Comparative Examples. ■...Film base, 2...Peeling layer, 3...Ink layer, 4...Heat-resistant layer, 5...Thermal transfer ink sheet, 6...Feeding reel, 7...Feeding roller ... Winding roller 9... Winding reel, 10... Recording paper, 11...
Drum, 12... Clamp, 13... Head, 14
・・・Head driver

Claims (2)

[Claims] (1) A thermal transfer ink sheet having a release layer on a film base and a hot-spreadable ink layer thereon is used, and the running speed of the thermal transfer ink sheet is 1/n (1. 1. A thermal transfer recording method characterized in that traveling is performed so that the speed is 1≦n) times. (2) The thermal transfer recording method according to claim (1), wherein the spreadable ink layer contains an amide component.