JPS6274689A - Thermally fusible type thermal sensitive transfer recording method - Google Patents

Abstract

PURPOSE:To faithfully transfer to record without lack of or without recording dot by using synthetic sheet having specific shapes of the depth of uneven surface and pitch as a sheet to be transferred. CONSTITUTION:A synthetic sheet 2 which has a surface shape including the depth of uneven surface smaller than the coating thickness of an ink layer 1b of an ink sheet 1 as a sheet to be transferred, the repetition pitch of the uneven surface smaller than the size of a heating element 3a of a thermal head 3, and the depth and the pitch of the an even surface larger than the ink pigment particle diameter of the sheet 1 is used. Since the sheet 2 has fine uneven surface and high smoothness, the bondability of the ink surface of the ink sheet to the surface of the synthetic sheet is excellent. Accordingly, a faithful transfer recording without lack of or without recording dot can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat-melting type thermal transfer recording method using synthetic paper as a transfer sheet.

[Prior art]

In general, a heat-melting type thermal transfer printer, as shown in FIG. , the ink surface and the transfer surface are overlapped so as to face each other, and they are pressed between a thermal head 3 equipped with a heating element 3a and a platen roller 4, and are heated by the thermal head 3 according to a recording signal, thereby recording. The ink on the ink sheet 1 is melted and transferred onto the transfer sheet 12 for recording.

Conventionally, plain paper or processed paper with a coating applied to the surface of plain paper has been mainly used as the transfer sheet.

[Problem that the invention seeks to solve]

By the way, when plain paper or processed paper is used as the transfer sheet as in the past, as schematically shown in FIG. The ink surface of the recording ink sheet 1 and the surface of the gill 12, which is the transfer surface, cannot be brought into sufficient contact. As a result, ink transfer failure occurs in areas where gaps have occurred, causing missing or missing recorded dots.

Such problems become particularly noticeable when high-resolution recording is performed by increasing the degree of integration of the heating elements of the thermal head.

The present invention was made in order to solve the above-mentioned problems in the conventional heat-melting type thermal transfer recording method, and provides a heat-melting type thermal transfer recording method that can perform faithful transfer recording without missing or missing recording dots. The purpose is to

[Means and effects for solving the eight points in between] In order to solve the above problems, the present invention uses synthetic paper 2 as a transfer sheet, as schematically shown in FIG. 1. . In addition, in FIG. 1, parts with the same reference numerals as in FIG. 8 indicate the same members.

That is, in the present invention, the depth of the surface irregularities is equal to the ink I! of the ink sheet 1! The coating thickness of the Jib is smaller than that of the heating element 3a of the thermal head 3, and the repetition pitch of the unevenness is smaller than the coating thickness of the Jib.
Synthetic paper 2 is used as the transfer sheet, and has a surface shape in which the depth and pitch of the unevenness are both larger than the particle size of the ink pigment of the ink sheet 1.

By using the synthetic paper 2 with such a surface shape as the transfer sheet, it is possible to bring the ink surface of the recording ink sheet l into close contact with the transfer surface of the synthetic paper 2, which is the transfer sheet. Ink transfer can be realized.

〔Example〕

Examples of the present invention will be described below. - There are two types of PfL muco synthetic paper: film method synthetic paper based on synthetic resin film and fiber method synthetic paper based on synthetic resin pulp, but the latter fiber method synthetic paper is similar to ordinary paper. Since it is made using a paper machine in the same way as the former, the surface smoothness is inferior to that of the former film method synthetic paper.

As the synthetic paper used in the heat-melting type thermal transfer recording method according to the present invention, the former film method synthetic paper is used. As such a film method synthetic paper, there is PFK-90 manufactured by Oji Yuka Synthetic Paper Co., Ltd. This synthetic paper is made of three layers of opaque films created by creating fine pores inside the film during biaxial stretching of polypropylene resin, and the surface is coated with printing ink. It has been treated with a resin to improve its adhesion.

FIG. 2 is a diagram showing the results of measuring the roughness of the surface of this synthetic paper used as a transfer sheet using a stylus-type surface roughness meter. As is clear from this figure, regarding the depth of the unevenness, the center line average roughness defined by JES BO601 is 1.5 μm or less, and the pitch of the unevenness is 10I! m or less.

In order to compare with the above-mentioned synthetic paper used in the present invention, the measurement results of surface roughness of uncoated paper and coated paper, which are special papers developed for conventional thermal transfer, are shown in Figs. 3 and 4. .

Figure 3 shows the measurement results for uncoated thermal transfer paper (TKP-13 manufactured by Kanzaki Seigi Co., Ltd.), and Figure 4 shows the measurement results for coated thermal transfer paper (TKP-9 manufactured by Kanzaki Seizi Co., Ltd.). FIG. As can be seen from both figures, in the case of uncoated paper, the depth of the unevenness is about 5 to 10 μm, which is larger than the ink layer thickness of a normal ink sheet (3 μm), and the pinch of the unevenness is about 50 to 100 μm. Most of it is the width of the heating element of the thermal head (about 60 μm)
In the case of coated paper larger than , the coating material (
The surface shape is quite smooth because it is coated with a water-soluble polymer glue (such as ``ri'', in which white clay, calcium carbonate, and other white inorganic pigments are dispersed), but the depth of the unevenness is small. is about 5μm, and the pinch of unevenness is about 50-
It is about 100 μm.

Next, the results of thermal transfer recording of a checkered pattern using the synthetic paper applied in the present invention and the same recording using the conventional uncoated paper and coated paper are shown in the fifth column.
It is schematically shown in Figure (Al, (81) to Figure 7 (8) and (B).

When performing recording using these transfer sheets, the ink sheet should be a general ink sheet made by applying heat-melting ink to a thickness of approximately 3 μm on a polyester film having a thickness of 6 μm. A commercially available product (manufactured by Fuji Kagaku Paper Industries Co., Ltd.) with a similar structure was used. In addition, as a thermal transfer printer, the heating element density is 16 dat/to (1 d
Line-type thermal head (approximately 60 μm width per ot)
A thermal printer manufactured by Kyocera Corporation and equipped with MT-256-16MGBB) was used. Note that the heat generating element density of the thermal head is at the highest level among thermal heads currently in practical use.

Figure 5 (Al, (13) is a cross-sectional view and a plan view showing the recording results using non-coated paper, 6 in the figure is an ink transfer section, 7
indicates an area where ink has not been transferred. As can be seen from this figure, the unevenness on the surface of the non-coated paper 12a is deeper than the thickness of the ink layer of the ink sheet (3 μm) (and the pitch of the unevenness is 60 μm, which is the size of the heating element of the thermal head). There are significant missing dots and missing members, that is,
Even when the paper is pinched by the platen roller and the thermal head, the degree of adhesion between the ink surface and the non-coated paper 12a is not sufficient, and a gap is generated partially, resulting in a portion 8 where no ink is transferred.

Furthermore, even if the ink is transferred, in the areas where the depth of the unevenness is greater than the thickness of the ink layer, the ink may be transferred to the non-coated paper 12a.
Since the recording dots cannot be completely hidden on the surface of the recording dots, a partial loss 9 of the recording dots occurs.

Figure 6 (Al, fBl are the same (conventional coated paper 12)
A cross-sectional view and a plan view showing the results of recording using b.
Although this is a considerable improvement over the case of uncoated paper ILI,
Incomplete transfer with partial loss of recording dots 9 is still quite visible.

On the other hand, when the synthetic paper 2 applied in the present invention is used, as shown in the cross-sectional view in Fig. 7 and the plan view in Fig. 7+81, no missing or missing recording dots are observed. , the pattern of checkered patterns is accurately recorded.

This is because, as described above, the synthetic paper 2 has much finer surface irregularities and higher smoothness than the conventional non-coated paper 12a and coated paper 12'o.

In other words, as mentioned earlier, the depth direction of the unevenness is much smaller than the thickness of the ink layer of 3 μm, and the pinch of the unevenness is also much smaller than the width of the heating element of the thermal head, which is 60 μm, so the ink surface of the ink sheet The adhesion between the synthetic paper and the synthetic paper surface is extremely good.

In addition, since the unevenness on the surface of this synthetic paper 20 is sufficiently larger than the particle size (about 0.1 μm) of the pigment in the ink, when the ink on the ink sheet is transferred, the pigment in the ink near the surface is synthesized. It can easily penetrate into the unevenness of the paper surface, resulting in good ink transferability.

In the above embodiment, as the synthetic paper, as shown in FIG.
The depth of the surface unevenness is 1.5 μm or less, and the repetition pitch of the unevenness is 10 μm or less. The surface formation is smaller than the thickness of the ink layer, the repeated pinch of unevenness is smaller than the size of the heating element of the applied thermal head, and the depth and pitch of the unevenness are both larger than the particle size of the ink pigment of the ink sheet. If you use synthetic paper, you can also obtain faithful transfer records.

〔Effect of the invention〕

As described above based on the embodiments, the present invention uses synthetic paper, which has an extremely smooth surface compared to conventional non-coated or coated paper, as a transfer sheet, so that recording dots that are not transferred can be easily removed. This allows for faithful transcription records with no missing parts or missing parts.

Furthermore, since the pitch of the unevenness on the surface of the synthetic paper used as the transfer sheet is sufficiently small compared to the size of the heating element of the thermal head, highly accurate recording can be performed by a head with higher density and resolution.

Furthermore, since we use synthetic paper with surface irregularities that are sufficiently shallow compared to the ink coating thickness of the ink sheet, we use a high-sensitivity, low-energy ink sheet with a thinner ink coating thickness than current ink sheets. becomes possible. Furthermore, since synthetic paper does not have water absorption properties, it is possible to obtain records with stable dimensional accuracy against humidity.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view schematically showing a heat-melting type thermal transfer recording mode using synthetic paper according to the present invention, FIG. 2 is a diagram showing the surface roughness of the synthetic paper used in the present invention, and FIG. Figure 4 shows the surface roughness of conventional uncoated paper, Figure 4 shows the surface roughness of conventional coated paper, and Figure 518 schematically shows the state of recording using uncoated paper. 5+81 is a plan view thereof, and FIG. 6^ is a sectional view schematically showing the state recorded using coated paper. Figure ^ is a cross-sectional view showing the state of recording using the synthetic paper according to the present invention, Figure 7 (top) is its plan view, and Figure 8 is a schematic diagram of the conventional heat-melting type thermal transfer recording type B. FIG. In the figure, 1 is an ink sheet, 1a is an ink sheet base material, 1b is an ink layer, 2 is a synthetic paper for transfer, 3 is a thermal head, 3a is a heating element, and 4 is a platen roller. Patent Applicant: Olympus Optical Industry Co., Ltd. Figure 1 1: Ia 7 Ant 1a: Inkun-Ftlλ 3: Zu-Ino V 1/F゛4゛ Buchdenzoller Figure 2 1001m 3rd factor Figure 4 1001m 5th!1 (A) (B) Figure 6 (A) (B) Figure 7 (C) (B)

Claims (1)

[Claims] The depth of the unevenness on the surface is smaller than the ink coating thickness of the ink sheet, the repetition pitch of the unevenness is smaller than the size of the heating element of the thermal head, and both the depth and pitch of the unevenness are smaller than the ink pigment of the ink sheet. 1. A heat-melting type thermal transfer recording method characterized in that a synthetic paper having a surface shape larger than a particle size is used as a transfer sheet.