JPS63162285A - Thermal transfer ribbon for gradation recording - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer ribbon for gradation recording having the superior linearity of a printing density changing according to a heating temperature and realizing a sufficiently high maximum density at the maximum heating temperature, by providing a fine porous layer of resin made of a saturated polyester on a substrate and containing a hot melt ink compounded with an oil-soluble sulfonic acid metal salt in the porous layer. CONSTITUTION:A thermal transfer ribbon for gradation recording is obtained by providing a fine porous layer of resin made of a saturated polyester on a substrate and containing a hot melt ink compounded with an oil-soluble sulfonic acid metal salt in the resin fine porous layer. As the saturated polyester, a saturated polyester having the solubility in solvent, the non-transfer properties under heat, a softening point of 100 deg.C or above, and a molecular weight of 400 or above is used. As the oil-soluble sulfonic acid metal salt to be compounded in the hot melt ink, a pertroleum sulfonate or a synthetic sulfonate is used. The resinous fine porous layer is preferably about 2-6 microns thick for the enhancement of heat sensivtivity. If a polyester is used as the substrate, the adhesion of the substrate to the resinous fine porous layer of the saturated polyester can be improved. The substrate is desirably 1-20 microns thick.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer ribbon for gradation recording.

[Background technology]

In recent years, with the diversification of information, consideration is being given to adopting thermal transfer ribbons for gradation recording in printers for terminals and the like. The thermal transfer ribbon for gradation recording changes the heating temperature when the heat-melting ink is melted and transferred by heating the heating head, and transfers a corresponding amount of the heat-melting ink.
That is, a gradation image is obtained by changing the optical density of the transferred image based on changes in the amount of hot melt ink. Such thermal transfer ribbons for gradation recording are required not only for single colors but also for multiple colors.

As such a thermal transfer ribbon for gradation recording, one in which a microporous resin layer is provided on a base material and a heat-melting ink consisting of pigment and wax is contained in the microporous resin layer is being considered. It had the disadvantage of lacking density gradation.

[Conventional technology]

In order to solve these drawbacks, the present inventors first
A heat-sensitive transfer material was proposed in which an oil-soluble sulfonic acid metal salt was added to a heat-melting ink contained in a resin microporous layer (Japanese Patent Laid-Open No. 14989/1989). According to this proposal, the oil-soluble sulfonic acid metal salt has a strong ionic group -S03, so it adsorbs to the pigment and stably disperses the pigment in the wax, so that the pigment forms a microporous layer. It has the effect that it does not migrate to the resin side and bleeds out together with the wax in response to changes in heating temperature, making it possible to obtain density gradation recording.

[Problem that the invention seeks to solve]

However, this proposal did not necessarily satisfy the characteristics required for gradation recording, that is, the linearity of print density that changes depending on the heating temperature (γ characteristics), and the use of chlorine as a resin forming the microporous layer When a vinyl/vinyl acetate copolymer or the like is used, there is less oozing of hot melt ink from the resin microporous layer, resulting in a decrease in density.

For this reason, when the microporous layer is made thicker to increase the amount of ink retained, a problem arises in that the thermal sensitivity decreases and the above-mentioned γ characteristics are adversely affected.

The above-mentioned problem also occurs in a current-carrying transfer ribbon in which an electrode is applied to a resistive layer and a current signal from a power source is applied to transfer heat-melting ink onto a recording sheet.

The present invention has been made based on the above circumstances, and is for gradation recording that has excellent linearity in print density that changes depending on the heating temperature, and has a sufficiently high print density when the heating temperature is changed to the maximum, that is, the maximum density. The purpose is to obtain a thermal transfer ribbon.

[Means for solving problems]

As a result of studies to achieve the above object, the present inventors have found that the above object can be achieved when the resin microporous layer containing the heat-melting ink containing an oil-soluble sulfonic acid metal salt is made of saturated polyester. We have discovered that this can be done, and have completed the present invention.

That is, the present invention provides gradation recording in which a microporous resin layer made of saturated polyester is provided on a base material, and a heat-melting ink containing an oil-soluble sulfonic acid metal salt is contained in the microporous resin layer. This is a thermal transfer ribbon for use.

C Effect] In the present invention, when saturated polyester is used as the resin microporous layer containing the heat-melting ink containing the oil-soluble sulfonic acid metal salt, why does it have excellent linearity in print density that changes depending on the heating temperature? However, the mechanism of action and how high maximum concentrations can be obtained are not necessarily clear. However, since both the oil-soluble metal sulfonate and the saturated polyester are incompatible, a structure is created in which the heat-melting ink containing the oil-soluble metal sulfonate is contained in the resin micropores of the saturated polyester that forms the continuous phase. It is also presumed that this is because no affinity acts between the resin microporous layer and the heat-melting ink, and therefore the amount of the heat-melting ink exuding changes favorably depending on the heating temperature.

In the present invention, the above-mentioned saturated polyester needs to be soluble in a solvent and non-transferable when heated, and for this reason, a polyester with a softening point of 100° C. or higher is used. Specifically, the product names are Byron 200 (Toyobo @), Byron 300 (by the same company), Byron 103 (by the same company), Byron 500 (by the same company), Polyester-TP-220 (Nippon Gosei Chemical Industry ■), Byron TP-
236 <Company), TP-217 (Company), TP-2
90 (Company), TP-249 (Company), LP-03
3 (Company), LP-01) (Company), LP-035
(Company), LP-044 (Company), etc. with a molecular weight of 400
The above can be mentioned.

Oil-soluble sulfonic acid metal salts blended into hot melt ink include petroleum sulfonates and synthetic sulfonates.
Specifically, the product names are Surhole Ca45N (-Matsuzai Oil Research Institute), Surhole Ca45 (the company), Moresco Amber 5C-45N (the company), and Moresco Amber-3.
Examples include C-45 (manufactured by the same company).

Waxes as other components blended into the hot melt ink are all incompatible with saturated polyester, such as petroleum waxes such as paraffin wax and microcrystalline wax; natural waxes such as carnauba wax and candelilla wax. Wax: Synthetic waxes such as montan wax, polyethylene wax, castor wax, fatty acid amide; various other waxes, ester waxes, etc. These waxes can be used alone or in combination.

Regarding color pigments as other components to be blended into the hot-melt ink, carbon black, nigrosine base, etc. can be used as color pigments that form black. As the coloring pigment that forms yellow, Hansa Yellow, Benzidine Yellow, Brilliant Fast Yellow, Permanent Yellow, Quinacridone Yellow, etc. can be used. Color pigments that form magenta include permanent red, permanent e-min, permanent lupine, permanent bordeaux,
Watch unbred, brilliant carmine, rhodamine lake, quinacridone pink, quinacridone magenta, quinacridone red, etc. can be used. Furthermore, as the coloring pigment that forms cyan, Victoria Blue Lake, Phthalocyanine Blue, Fast Sky Blue, etc. can be used. In addition, various pigments conventionally used in the field of thermal transfer ribbons can be used.

In the present invention, the resin microporous layer containing the heat-melting ink is prepared by mixing a wax and an oil-soluble sulfonic acid metal salt with a colored pigment to make a colored wax, and dispersing this colored wax in a resin solution of saturated polyester. The thus obtained liquid mixture is applied to a base material and then dried to form a coating.

The resin microporous layer thus obtained has a smooth layer surface and can have fine pores, but the thickness of the layer is preferably about 2 to 6 microns in order to improve thermal sensitivity. The saturated polyester, oil-soluble sulfonic acid metal salt, wax, and coloring pigment are 15 to 60% by weight, 5 to 30% by weight, and 15 to 60% by weight, respectively, based on the total amount of the resin microporous layer containing the heat-melting ink. and 5-25
It is preferable that they are blended in a proportion of % by weight.

The base material is preferably a heat-resistant material that does not fuse to the thermal head, but if necessary, a heat-resistant protective film may be provided on the surface that contacts the thermal head. Note that if polyester is used as the base material, the adhesion of the saturated polyester to the resin microporous layer can be improved. The thickness of the base material is preferably 1 to 20 microns.

Furthermore, when the thermal transfer ribbon of the present invention is used for electrical transfer recording, the base material may be made of two layers, and the layer on the side in contact with the electrode may be a resistive layer that generates heat when electricity is applied. This resistance layer can be formed, for example, by dispersing a conductive substance in a resin layer.

In this way, the thermal transfer ribbon for gradation recording of the present invention has a resin microporous layer provided on a base material provided with a heat-resistant protective film as required, and contains one color of heat-melting ink in the resin micropores. Alternatively, a plurality of microporous resin layers containing heat-melting inks of different colors are provided on the same base material.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows a thermal transfer ribbon for gradation recording in which a microporous resin layer 2 containing heat-melting ink is provided on a base material l.

Figures 2 and 3 show the base material 1 and resin microporous '1tN2 containing yellow, magenta, and cyan inks.
y, 2M, 2C, resin microporous N2Y, 2M
, 2C are arranged on the base material 1 in continuous repeating units along the length direction thereof, and the resin microporous layers 2Y, 2
This is a thermal transfer color ribbon for gradation recording, in which M and 2C are both the same size as recording paper.

This ribbon is used to melt and transfer ink of each color onto recording paper by heating with a thermal head to obtain a desired color image. Specifically, for example, yellow ink is melt-transferred onto recording paper, and then cyan ink is melt-transferred onto it, and the two colors of ink are deposited in layers on the recording paper to create a green color image. Use to get.

Figure 4 shows microporous resin N containing black ink in addition to microporous resin F52Y, 2M, and 2C.
2B is an angry heat transfer color ribbon for gradation recording formed in a continuous manner on the base material 1 in the same manner. This ribbon is used when it is difficult to reproduce clear black by overlapping three colors of yellow, magenta, and cyan.

Figure 5 shows a thermal transfer color for gradation recording in which the base material 1 is formed into a thin strip shape, and the lengths of the microporous resins N2Y, 2M, and 2C are all the same length as the width of the recording paper. It's a ribbon.

FIG. 6 shows a window thermal transfer ribbon for gradation recording in which the base material 1 consists of two layers 1a and 1b, and the layer 1b is a resistive layer that generates heat when energized.

This ribbon uses a microporous resin material N2 facing the recording paper 3, and during transfer recording, a current signal from a power source 4 is applied to scan the resistive layer lb.

〔Example 〕

Next, examples of the present invention will be shown. Parts indicate parts by weight.

Example 1 Each component was mixed in a heated attritor with the following formulation.
A yellow colored wax was produced by timed heating and dispersion.

Carnauba wax 15 parts Polyethylene wax 15 parts Petroleum sulfonate (Note 1)
15 parts Yellow pigment (Note 2) 10-part-
55 copies Note 1: Made by Matsumura Oil Research Institute, trade name Sulhole Ca45 Note 2 = Made by Dainippon Ink Industries ■, trade name First Yellow 8CF Using the above colored wax, each component was mixed into a water-cooled attritor with the following formulation. A dispersion liquid (solid content: 25%) in which fine particles of colored wax were dispersed in a solvent was prepared.

Pigment dispersion wax 55 parts Methyl ethyl ketone 140 parts Toluene -
25-ri-220 parts On the other hand, each component was mixed according to the following formulation to make 2 of the resin.
A 5% solution was made.

Saturated polyester (Note 3) 40 parts Methyl ethyl ketone 60 parts Toluene
- Mitate - Plate - 160, part note 3; manufactured by Toyobo II, trade name Byron #200, softening point 163°C.Next, 160 parts of the above resin solution and 220 parts of the above dispersion liquid were mixed, and this mixed liquid was coated onto a polyester film with a thickness of 6 microns using a wire bar so that the thickness after drying was 3.5 microns, and a fine porous resin layer containing yellow ink was used for gradation recording. I made a thermal transfer ribbon.

Using this curse transfer ribbon, solid transfer was performed using a thermal printer while changing the energy of the thermal head in 8 steps up to 1.0 mj/dat, and the optical reflection density (0, D) of each transferred image was measured. As shown in FIG. 7, the transferred image density increased in accordance with each energy level of the thermal head, and the maximum density was also sufficiently high.

Example 2 A resin microporous material containing magenta ink was prepared in the same manner as in Example 1, except that a magenta pigment (manufactured by Dainippon Ink Co., Ltd., trade name: Red #305B) was used instead of the yellow pigment. A thermal transfer ribbon for gradation recording comprising layers was made.

Solid transfer was performed using this thermal transfer ribbon in the same manner as in Example 1, and the optical reflection density (0°D) of each transferred image was measured. The transferred image density increased and the maximum density was also sufficiently high.

Example 3 A resin microporous layer containing cyan ink was prepared in the same manner as in Example 1, except that a cyan pigment (manufactured by Dainichi Seika, trade name: Cyanine Blue 94920G) was used instead of the yellow pigment. A thermal transfer ribbon for gradation recording was made.

Solid transfer was performed using this thermal transfer ribbon in the same manner as in Example 1, and the optical reflection density (0°D) of each transferred image was measured. The transferred image density increased, and the maximum density was also sufficiently high.

Example 4 A microporous resin containing black ink was prepared in the same manner as in Example 1, except that a black pigment (manufactured by Mitsubishi Chemical Industries, Ltd., trade name: Carbon Black MA-1) was used instead of the yellow pigment. A thermal transfer ribbon for gradation recording with a texture layer was made.

Solid transfer was performed using this thermal transfer ribbon in the same manner as in Example 1, and the optical reflection density (0°D) of each transferred image was measured. The transferred image density increased and the maximum density was also sufficiently high.

Example 5 The liquid mixtures prepared in Examples 1 to 3 were applied onto a polyester film with a thickness of 6 microns using a gravure printing machine so that the thickness after drying would be 3.5 microns. A heat-sensitive transfer ribbon for gradation recording, as shown in the figure, including a plurality of resin microporous layers containing yellow ink, magenta ink, and cyan ink, respectively, was produced.

When this thermal transfer ribbon was used for transfer recording using a video printer (@Hitachi, Ltd., product 4vy-50), a full-color image with high gradation and faithful to the original was obtained.

〔Effect of the invention 〕

As explained above, the present invention provides a thermal transfer ribbon for gradation recording in which the printing density of a transferred image changes linearly in accordance with changes in heating temperature, and the printing density is high when the heating temperature is changed to the maximum. is what was obtained.

[Brief explanation of the drawing]

1 is a schematic cross-sectional view of a thermal transfer ribbon for gradation recording of the present invention, and FIG. 2 is a schematic plan view showing an embodiment of the same ribbon.
FIG. 3 is a schematic sectional view of FIG. 1, FIGS. 4 and 5 are schematic plan views showing other embodiments of the thermal transfer ribbon of the present invention, and FIG. 6 is a schematic plan view of other embodiments of the thermal transfer ribbon of the present invention. FIGS. 7 to 10 are schematic cross-sectional views showing the embodiment of the present invention, and are diagrams showing the relationship between the energy of the thermal radar and the optical reflection density of the transferred image, respectively. 1 is a base material, and 2.2Y, 2M, 2C and 2B are resin microporous layers containing hot melt ink.

Claims (4)

[Claims] (1) A resin microporous layer made of saturated polyester is provided on a base material, and a hot melt ink containing an oil-soluble sulfonic acid metal salt is contained in the resin microporous layer.
Thermal transfer ribbon for gradation recording. (2) The gradation recording according to claim 1, wherein the heat-melting ink is at least yellow, magenta, and cyan, and a plurality of resin microporous layers containing each of these inks are provided on the same base material. Thermal transfer ribbon. (3) The thermal transfer ribbon for gradation recording according to claim 1, wherein the base material is polyester. (4) The gradation recording device according to claim 1, wherein the base material is composed of two layers, and the layer opposite to the layer on the side to which the resin microporous layer is in close contact is a resistive layer that generates heat when energized. Thermal transfer ribbon.