JP2581096B2 - Transfer type thermal recording sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transfer-type thermosensitive recording sheet used for printing on a television printer, for example.

[Conventional technology]

2. Description of the Related Art In recent years, various types of non-impact recording apparatuses, particularly, thermal recording apparatuses have been put to practical use.

Demand for thermal recording devices has been increasing as output devices for information processing and the like because of the simplicity of the device as well as the simplicity of the device as well as the elimination of maintenance labor and the like. For example, in facsimile machines, computer peripheral terminal printers, and television printers, this type of thermal recording apparatus has been increasingly used as a printing means for output.
In a television printer, a dye transfer type thermal recording method is adopted in view of vividness of color and easy gradation. FIG. 2 is a cross-sectional view showing a conventional transfer-type thermal recording method shown in, for example, page 18 of the Journal of the Institute of Image Electronics Engineers of Japan, vol. 12, (1983), wherein (1) shows a base film and ( 2) a dye layer, (3) a transfer type thermosensitive recording sheet, (4) a dye, (5) a resin layer, (6) a support,
(7) is a transfer type thermosensitive recording medium, and (8) is a thermosensitive head. That is, the transfer-type thermosensitive recording sheet (3) and the transfer-type thermosensitive recording medium (7) are superimposed, and the heat-sensitive head (8) is used.
When heated from above the base film (1), the dye (4) sublimates or melts and is transferred onto the resin layer (5). Further, Japanese Patent Application Laid-Open No. 57-160691 discloses a technique in which a fine powder is contained to reuse an ink sheet.

[Problems to be solved by the invention]

However, when the transfer type thermal recording medium is plain paper, the dye sublimated or melted hardly binds to the paper fibers and drops off with a small pressure. In order to fix the dye on the recording medium, for example, a
It is necessary to apply a resin or the like in the drawing, which increases the cost of the paper.

Further, in the case of an ink transfer type thermal recording sheet, since the ink is transferred by heat, recording can be performed even on plain paper, but there is a problem that gradation cannot be obtained. or,
Japanese Patent Application Laid-Open No. 57-160691 does not contain the following dispersing medium, so that there is a problem that the dye is not gradually transferred and the gradation of the print is inferior.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a transfer-type thermal recording sheet having high recording sensitivity, capable of recording even on plain paper, and obtaining recording with gradation. And

[Means for solving the problem]

The transfer type thermal recording sheet of the present invention has a melting point of 140 ° C.
A dye layer in which a fine-grained phase composed of the following low-melting point disperse dye and a fine-grained phase composed of at least one of wax and a low-melting point resin are dispersed in a dispersion medium phase, and a surface of the dye layer facing the heat-sensitive head. And a base film for preventing leakage of the dye layer.

[Action]

It is conceivable that the dye layer is transferred by heat as the first step of the transfer mechanism, and after transfer, the surrounding dye moves through the remaining holes by heat.

At this time, since the dye layer contains the dispersion medium, the dye moves through the fine pores formed in the dispersion medium, so that the dye moves along the diffusion side of the Fick, and the transfer amount is proportional to the applied energy. Increase. Therefore, the transfer type thermal recording sheet of the present invention has a gradation property proportional to the applied energy.

Such a gradation is obtained because, in the conventional ink transfer, there is no dispersion medium, and thus the entire ink layer is melted by the applied heat, and the gradation cannot be obtained. In this case, since the dispersion medium is used, the dye diffuses through the pores formed in the dispersion medium, and thus has a gradation.

In addition, since at least one of the wax and the low-melting-point resin is compatible with the dye and transferred to the recording medium, even if the recording medium is plain paper, the recording medium is fixed to the paper fibers and can be recorded. In addition, when the dye and the above-mentioned dye are compatible with each other, the wax and the low melting point resin and the dye are in the same melting state, so that they are easily compatible with each other and the recording sensitivity is increased.

FIG. 1 is a cross-sectional view of a transfer-type thermosensitive recording sheet according to an embodiment of the present invention. In FIG. 1, (1) is a base film, (2) is a dye layer, and (4) is a dye. , (9) is at least one of wax and low melting point resin, and (10) is a dispersion medium.

That is, when the transfer type thermosensitive recording sheet (3) is heated from above the base film (1), the dye (4) melts and moves onto the recording medium. At this time, at least one of the wax and the low-melting point resin (9) also melts, and the dye layer (2)
Is mixed with the dye (4) while moving or on a recording medium, and is fixed on the recording medium. Therefore, a resin layer on a recording medium that is frequently used in a dye transfer type becomes unnecessary.

Examples of the low-melting dyes according to the embodiments of the present invention include anthraquinone-based and azo-based disperse dyes such as SOT-Blue2 (trade name: 120 ° C.) and SOT-BlueG manufactured by Hodogaya Chemical.
(Melting point 77 ° C), SOT-Red2G (melting point 140 ° C), SOT-Yellow
5 (melting point 120 ° C.).

Examples of the wax and the low melting point resin according to the embodiment of the present invention include carna powder, paraffin wax, petroleum wax and a low melting point epoxy resin (manufactured by Yuka Shell, trade name Epicoat 1004, etc.).

The base film according to the embodiment of the present invention includes:
For example, cellophane paper, condenser paper, polyethylene terephthalate sheet, polyimide film and the like can be mentioned.

Examples of the dispersion medium according to the embodiments of the present invention include polyvinyl alcohol, casein, gelatin, modified starch, gum arabic, sodium alginate, zinc pectin, polyvinylpyrrolidone, carboxymethylcellulose, methylcellulose, polyacrylamide,
Examples include polyacrylic acid, polyethylene oxide, polyvinyl methyl ether, polyvinyl pyridine, and polystyrene sulfonic acid. In order to suitably disperse the dye, it is preferable to appropriately select and use one of the above dispersion media depending on the dye. For example, when using an anthraquinone dye, it is preferable to use polyvinyl alcohol, and when using an azo dye, it is preferable to use polyvinyl pyrrolidone.

The ratio of the dye to the dispersion medium used in the embodiment of the present invention is desirably 0.1 to 4 parts by weight of the dye per 1 part by weight of the dispersion medium. If the content is less than 0.1 part by weight, the saturation concentration is too low, and if it is more than 4% by weight, the base film is broken.

At least one of the wax and the low-melting point resin used in the embodiment of the present invention is 0.1 to 1 part by weight of the dispersion medium.
Desirably, it is 4 parts by weight. When the amount is less than 0.1 part by weight, it is difficult to transfer the image to plain paper, and when the amount is more than 4 parts by weight, the base film is broken.

The thickness of the dye layer according to the embodiment of the present invention is 1 to 20 μm.
It is desirable that If it is 1 μm or less, the saturation concentration is too low, and if it is 20 μm or more, the resolution is poor.

Hereinafter, the present invention will be described specifically with reference to Examples.
The present invention is not limited to this.

Example 1 Anthraquinone-based disperse dye (manufactured by Hodogaya Chemical, trade name: SO
10 parts by weight of T-Blue 2), 10 parts by weight of paraffin wax, 0.1 part by weight of sodium lauryl sulfonate as a dispersant and 40 parts by weight of water are dispersed for 10 minutes by a paint conditioner. 20 parts by weight of the mixture and 20 parts by weight of a 10% aqueous solution of polyvinyl alcohol were mixed, applied to a 6 μm polyethylene terephthalate sheet with a wire bar to a final thickness of 16 μm, and dried. I got When the above paper and the above paper are superimposed and printing is performed by changing the pulse width with a thick film head under the conditions of 16 V and 400 Ω, the reflection density (OD) of the printing according to the pulse width (τ) is shown by a curve in FIG. A blue print having a reflection density as shown in (a) was obtained, and gradation was observed. The vertical axis in the figure is OD
And the horizontal axis represents τ in [mS].

Example 2 Azo-based disperse dye (manufactured by Hodogaya Chemical, trade name: SOT-Red2G)
15 parts by weight, 10 parts by weight of carnapower, 0.2 parts by weight of sodium lauryl sulfonate as a dispersant and 35 parts by weight of water are dispersed for 10 minutes by a paint conditioner. This one
20 parts by weight and 20 parts by weight of a 10% aqueous solution of polyvinylpyrrolidone were mixed, applied to a 6 μm polyethylene terephthalate sheet with a wire bar so as to have a final thickness of 16 μm, dried, and then transferred to another example of the present invention. Sheet was obtained. When this was superimposed on high-quality paper and a voltage was applied with a pulse width of 3 mS using a thick film head of 16 V and 400 Ω, a red print having a reflection density (OD) of 0.92 was obtained. When the pulse width was changed under the above thick film head conditions as in Example 1, the characteristics shown in FIG. 3 (b) were obtained, and the gradation was observed.

Comparative Example 3 parts by weight of an azo black dye, 5 parts by weight of polyethylene glycol, 5 parts by weight of carbon black
The ink composition was dissolved in a mixed organic solvent consisting of parts by weight of isopropyl alcohol and 5 parts by weight of toluene to prepare an ink composition. This was applied to a 6 μm polyethylene terephthalate sheet with a wire bar to a final thickness of 16 μm and dried. When this was superimposed on high-quality paper, and printing was performed using a 16 V, 400 Ω thick film head while changing the pulse width, printing with a reflection density as shown in FIG. 3 (C) was obtained. Poor tonality.

〔The invention's effect〕

As described above, in the present invention, a fine-grained phase composed of a low-melting-point disperse dye having a melting point of 140 ° C. or lower and a fine-grained phase composed of at least one of wax and a low-melting-point resin are dispersed in a dispersion medium phase. By using a dye layer and a base film which is provided on the heat-sensitive head facing side of the dye layer and which prevents the dye layer from leaking, it is possible to obtain a record which can be recorded on plain paper and has gradation. Transfer type thermosensitive recording sheet can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a transfer type thermal recording sheet according to one embodiment of the present invention, FIG. 2 is a cross-sectional view showing a conventional transfer type thermal recording method, and FIG. FIG. 4 is a characteristic diagram showing the gradation of a thermosensitive recording sheet. In the figure, (1) is a base film, (2) is a dye layer, (3) is a transfer type thermosensitive recording sheet, (4) is a dye,
(9) is at least one of wax and low melting point resin, and (10) is a dispersion medium. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A dye layer in which a fine-grained phase comprising a low-melting-point disperse dye having a melting point of 140 ° C. or lower and a fine-grained phase comprising at least one of a wax and a low-melting-point resin are dispersed in a dispersion medium phase. And a transfer type thermosensitive recording sheet provided with a base film provided on the surface of the dye layer facing the thermal head and preventing the dye layer from leaking.