JPS60176797A - Transfer-type thermal recording method - Google Patents

Abstract

PURPOSE:To enable repeated transferring to be performed easily with favorable sensitivity and conduct transfer-type thermal recording suitable for facsimile or the like, by using a sheet of a water-soluble resin material containing a dye mixed therein and a medium comprising a protein material. CONSTITUTION:A transfer-type thermal recording sheet 4 comprising a water-soluble resin material 6, preferably, denatured starch, containing a dye 5, e.g., an azo disperse dye, mixed therein and a sealing film 1 and a transfer-type thermal recording medium 7 comprising a base 9, e.g., a paper, coated with a protein material 8, e.g., casein, are used. The dye 5 in the sheet 4 is caused to exude into the protein material 8 in the medium 8 by heating, whereby recording is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a transfer type thermal recording sheet used for printing, for example, in a facsimile machine or a peripheral terminal printer.

[Prior art]

In recent years, various types of non-impact recording devices have been put into practical use, and thermal recording devices in particular are useful for information processing, etc. because they require less maintenance, are noiseless, are non-polluting, and have a simple structure. Demand is increasing as an output device. For example, in peripheral terminal printers for facsimiles and computers.

This type of thermal recording device is increasingly being used as a printing means for output. There are two main heat-sensitive methods: a chemical coloring method and a transfer method. Among these, many of the chemically colored types can be easily erased with plasticizers, solvents, adhesive tapes, etc.

Furthermore, it has disadvantages such as the ease of additional printing and the possibility of falsification, making it unsuitable for securities, legal documents, and the like.

On the other hand, the transfer type has attracted particular attention in recent years as a method for overcoming the drawbacks of the above C.

As shown in No. 1 and 1, the conventional transfer type heat-sensitive recording sheet (3) is sealed with 1, for example, cellophane or parchment paper.
Solid ink with a thickness of 11 and several μm f! i 121, and the solid ink layer (2) has a melting point of, for example, 80
It is formed by dissolving a resin such as carnauba wax or polyethylene glycol at ~120° C. in a solvent, applying it onto the sealing film (1) to a thickness of about 4 μm using a wire bar, and drying it. Thermosensitive recording is carried out by melting the solid ink layer (2) by heating and transferring it onto paper.

However, with conventional transfer type thermal recording sheets.

Generally, the thickness of the solid ink layer (2) is as thin as about 4 μm in order to improve recording resolution and sensitivity. For this reason, transcription can only be performed once.

For example, for recording on one A4 size sheet, one A4 size transfer type heat sensitive recording sheet is required, and therefore there is a desire to develop a high resolution transfer type heat sensitive recording sheet that can be used repeatedly many times. Ta.

In order to overcome the above drawbacks, a method has been proposed in which carbon black is dispersed in the solid ink layer (2) to suppress ink elution, but with this method, there is a risk that the carbon black itself will be transferred onto the paper. Another disadvantage is that the reflection density of the printed area decreases with the number of transfers.

Therefore, in order to improve the above-mentioned drawbacks, the special public
There is a dye transfer type heat-sensitive recording sheet described in Japanese Patent No. 8793. According to this method, it is possible to transfer many times until the sublimable dye in the sheet is used up. The sublimation temperature is high (150~200℃)
So that's it.

It had poor sensitivity.

In addition, there are examples of recording using protein using paper coated with protein and printing with printing ink. A dispersed product was used, and dyes and the like were not diffused into the protein layer by applying heat.

[Summary of the invention]

This invention was made to eliminate the above-mentioned conventional drawbacks, and uses a transfer-type heat-sensitive recording sheet containing a water-soluble resin material mixed with a dye.

Transfer type heat-sensitive recording medium is made of a proteinaceous material, and the dye of the transfer type heat-sensitive recording sheet is eluted into the protein material of the transfer type heat-sensitive recording medium by heat for recording, making the transfer easy. It is an object of the present invention to provide a transfer type thermal recording method that has good sensitivity and allows repeated transfer.

[Embodiments of the invention]

FIG. 2 is a sectional view of a transfer type heat-sensitive recording sheet and a transfer type heat-sensitive recording medium used in one embodiment of the present invention. In the figure, (4) is a transfer type heat-sensitive recording sheet, and dye (5)
) and a water-soluble resin material (6) mixed with the water-soluble resin material (6).

A sealing film 111 is provided on the surface of the water-soluble resin material (6) facing the thermal head to prevent leakage of the water-soluble resin material (6). In addition, (7) is a transfer type thermosensitive recording medium, and the support (
9) coated with a protein material (8). Here, if the sealing film (1) is heated from above with a thermal head.

A part of the dye in the water-soluble resin material (6) is dissolved by heating, passes through minute holes in the water-soluble resin material, and is eluted onto the protein material (8) of the transfer type thermosensitive recording medium (7) for recording. It is.

After that, the transfer type heat-sensitive recording sheet and the transfer type heat-sensitive recording medium are separated and the transfer type heat-sensitive recording medium is heated.

It is thought that the dye eluted onto the protein material (8) dissolves again and diffuses into the protein material (8), and the protein and dye form a stable complex, thereby fixing and fixing the image.

Examples of the sealing film used in the present invention include cellophane, polymer films such as polyethylene terephthalate (pET) sheets, and capacitor paper.

The type of dye to be used in this invention is basically not limited, but because the lower the melting point, the better the sensitivity, for example, anthraquinone-based and azo-based disperse dyes are preferably used. Here, the dye is preferably used in an amount of 1 to 80 parts per 8 parts of the water-soluble resin. If it is less than 1 part by weight, the recording density (abbreviated as OD) is too low, and if it is more than 80 parts by weight, a transfer type heat-sensitive recording sheet with sufficient mechanical strength cannot be obtained.

Examples of water-soluble resins used in this invention include polyvinyl alcohol (PVA), casein, gelatin, modified starch, gum arabic, sodium alginate, zinc caseinate, pectin, polyvinylpyrrolidone, carboxymethylcellulose, methylcellulose, polyacrylic acid amide, and polyvinyl pyrrolidone. Examples include acrylic acid, polyethylene oxide, polyvinyl methyl ether, polyvinyl pyridine, and polystyrene sulfonic acid.

In addition, it is also preferable that the water-soluble resin material contains a surfactant. Examples of the surfactant include nonionic surfactants such as sorbitan, but sorbitan monooleate, which is liquid at room temperature, causes a large background fog.

Sorbitan monostearate, sorbitan monopalmitate, and the like having a melting point of 50 to 60°C are preferably used because they do not cause background fog.

Examples of proteins used in this invention include casein,
Examples include gelatin and ovalbumin.

As mentioned above, the dye and protein form a stable complex due to the strong interaction between the dye and the amino acids that are the constituents of the protein, particularly phenylalanine, tyrosine, histidine, and tryptophan.

It is thought that the recording density is also increased. The interaction between this dye and amino acids has been partially clarified by the complex structure of copper chlorophyllin, histidine, and tryptophan proposed in the following publication, but the essence is said to be an interaction based on π-π stacking. (Publication name: Journal of the Chemical Society of Japan, p. 131, published in 1983). or,
The protein material of the present invention contains 2 fillers such as clay, barium sulfate, and kaolin to improve surface smoothness and increase the strength of the coating film, and fillers such as starch and other fillers to increase the strength of the coating film. It may contain molecules.

Note that since these proteins are water-soluble, no organic solvent or the like is required when coating them on a support.

In view of cost and pollution problems, they are preferably used compared to oil-soluble resins such as thermoplastic resins.

As the support used in this invention, paper is generally used, but for example, plastic sheets, metal foils, etc. can also be used as appropriate.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

Example 1 8 parts by weight of polyvinyl alcohol and 16 parts by weight of an azo disperse dye (manufactured by Hodogaya Chemical, trade name 80T-Blue 7)
2) e 8 parts of surfactant sorbitan monostearate and 92M acid part of water are scoured in a ball mill for one day and night. This kneaded material is defoamed by a vacuum defoaming method. This material is polyethylene terephthalate with a thickness of 6 μm) (P
ET) Coat the sheet with a wire bar to a thickness of 20 μm and dry to obtain a transfer-type heat-sensitive recording sheet. On the other hand, casein 1
0 parts by weight.

5M parts of kaolin and 90 parts by weight of water are milled in a ball mill for a day and a night. This material was coated on high-quality paper to a thickness of 6 μm and dried to obtain a transfer type heat-sensitive recording medium. The above-mentioned transfer type heat-sensitive recording sheet and transfer type heat-sensitive recording medium are superimposed, and a thin film type heat-sensitive head is applied to this with a voltage of 6V and a pulse number of 10.
Printing is performed under the conditions of 0 Hz and pulse application time of 3 ms. Separate the print-printing transfer type thermal recording sheet and the transfer type thermal recording medium.

The transfer type thermosensitive recording medium was heated in an oven at 1000 for 2 minutes. As a result, an image with an OD of 1.2 was obtained.

Example 2 10 parts by weight of hydroxypropyl starch (manufactured by Matsutani Chemical, trade name Stacodex) and 16 parts by weight of sublimable dye (
Hodogaya chemical table, product name 80T-B4ack-6) on water 9
It is refined in a ball mill all day and night together with the zero-weight weighing section. This material was coated onto a 6 μm thick PET sheet using a wire bar to a thickness of 15 μm and dried to obtain a transfer type heat-sensitive recording sheet. On the other hand, coated paper (manufactured by Mitsubishi Paper Industries, trade name: Varconit), which is made by coating high-quality paper with protein, is used as a transfer type heat-sensitive recording medium. The above-mentioned transfer type thermosensitive recording sheet and transfer type thermosensitive recording medium were stacked together, and a thick film type thermal head was used to apply a voltage of 16 V, a pulse number of 100 Hz, and a pulse application time of 3.
Print under ms conditions. The recorded image of this product was stable even without heat fixing, and the OD was 1.1. Third
The figure shows the change in recording density (OD) depending on the number of transfers (times) when the above-mentioned transfer-type heat-sensitive recording sheet is used to repeatedly record on the above-mentioned transfer-type heat-sensitive recording medium. It can be seen that the transfer type heat-sensitive recording sheet of the example can be used repeatedly 10 times.

Example 3 8 parts of gum arabic and 10 parts by weight of azo dye (manufactured by Hodogaya Chemical, trade name: OHRed) ali 8 parts of gum arabic and 92 parts of water as a surfactant sorbitan monostearate Refined in a ball mill all day and night. This kneaded material is defoamed by a vacuum defoaming method. PK with a thickness of 6μ0
? Coat the sheet with a wire bar to a thickness of 25 μm and dry to obtain a transfer type heat-sensitive recording sheet. On the other hand, 12 parts by weight of gelatin was dissolved in 8 parts J of water heated to about 40°C, and this solution was coated on high-quality paper to a thickness of 5 μm.
It is dried and used as a transfer type heat-sensitive recording medium. The transfer type heat-sensitive recording sheet and the transfer type heat-sensitive recording medium were superimposed and printing was performed under the same conditions as in Example 2, and then the transfer type heat-sensitive recording sheet and the transfer type heat-sensitive recording medium were separated.

The transfer type thermosensitive recording medium was heated with an iron at 100° C. for 1 minute. As a result, an OD of 1.4 was obtained.

〔Effect of the invention〕

As explained above, the present invention uses a sheet with a water-soluble resin material mixed with a dye as a transfer type heat-sensitive recording sheet, uses a sheet with a proteinaceous material as a transfer type heat-sensitive recording medium, and uses heat to form a transfer type. By dissolving the dye from the heat-sensitive recording sheet into the material of the transfer-type heat-sensitive recording medium and recording.

It is possible to obtain a transfer-type thermal recording method that allows easy transfer, high sensitivity, and repeatable transfer.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional transfer-type heat-sensitive recording sheet;
The figure is a sectional view of a transfer type thermosensitive recording sheet and a transfer type thermosensitive recording medium used in an embodiment of the present invention, and Fig. 3 shows the recording density according to the number of transfers (times) in an embodiment of the present invention.
It is a characteristic diagram showing a change in OD). In the figure, (11 is a sealing film, (2) is a solid ink layer, (3) is a transfer type thermal recording sheet), (41 is a transfer type thermal recording sheet), +51 is a dye, and (6) is a water-soluble layer. (7) is a transfer type thermosensitive recording medium, (8) is a material having protein, and (9) is a support. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 Number of transcriptions (times) Mr. Commissioner of the Japan Patent Office 1. Indication of the case Japanese Patent Application No. 59-031764 2 Title of the invention Width and thickness type thermal recording method 3 Amendments to be made Person a Column 6 for the detailed description of the invention in the specification subject to amendment Contents of the amendment (1) Correct "lower degree" in line 5 of page 6 of the description to "lower degree". (2) On page 11, line 4, ``rl-monowa'' is corrected to ``〆monowo''.

Claims (1)

[Claims] +11 A transfer-type heat-sensitive self-recording sheet containing a water-soluble resin material mixed with a dye is used, a transfer-type heat-sensitive recording medium containing a protein material is used, and a heat-sensitive recording sheet is used. A transfer heat-sensitive recording method in which dyes from a transfer heat-sensitive recording sheet are eluted into a proteinaceous material of a transfer heat-sensitive recording medium for recording. (2) The transfer type thermal recording method according to claim 1, wherein the water-soluble resin is modified starch.