JPS59124890A - Heat-sensitive transfer sheet - Google Patents

Abstract

PURPOSE:To enhance transferring efficiency, by providing a diffusion barrier layer between an ink layer and a base of a heat-sensitive transfer sheet comprising an ink layer containing a thermally transferrable dye on a base. CONSTITUTION:The diffusion barrier layer through which the thermally transferrable dye can not diffuse is provided between the ink layer and the base of the heat-sensitive transfer sheet. A material used for the diffusion barrier layer is preferably, for example, a polymer layer which is not softened by heat (150 deg.C or higher), for example, a gelatin derivative such as phthalated gelatine. The thickness of the diffusion barrier layer may be arbitrarily set, provided that thermal diffusion of an ink is substantially prevented, and is preferably not smaller than 0.5mum. The barrier layer in the present invention may comprise a hardener or other additives. The ink layer comprising the thermally transferrable dye preferably comprises a binder, which may be a hydrophilic or hydrophobic synthetic or natural polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-sensitive transfer sheet, and more specifically to a heat-sensitive transfer sheet.
Accordingly, the present invention relates to a heat-sensitive transfer sheet that has improved transferability of the dye contained in the heat-sensitive transfer sheet to an image-receiving medium.

Conventionally, ink sheets used in thermal transfer printers,
Heat-sensitive transfer sheets called ink ribbons are known to have heat-transferable dyes dispersed in a binder such as cellulose ester and coated on a substrate such as polyester film, polyimide film, or capacitor paper. . However, polyimide films are extremely expensive, and polyester films and condenser papers have the disadvantage that the dye permeates into the substrate, resulting in low transfer efficiency (m/thermal energy of transferred dye) in thermal transfer.

Therefore, an object of the present invention is to clarify a heat-sensitive transfer sheet that has high transfer efficiency and can be provided at low cost.

The present invention, which achieves the above object, provides a thermal transfer sheet in which an ink layer containing a sublimable, vaporizable, or migratory thermal transferable dye is formed on a substrate, in which a layer is formed between the ink layer and the substrate. The present invention is characterized in that a protection layer is provided to prevent the thermally transferable dye from substantially thermally diffusing.

The present invention will be explained in detail below.

A feature of the present invention is that paper or other image-receiving medium or printing medium and a thermal transfer ink sheet are overlapped, and heat is transferred from the back side of the ink sheet to the mouth by changing the heating time or temperature of a thermal transfer means such as a thermal energy head. Then, the image is transferred onto the image-receiving paper or other image-receiving medium. The thermal transfer method according to the present invention transfers images onto an image receiving medium such as image receiving paper by overlapping paper or other image receiving medium with a thermal transfer sheet and applying a thermal energy key from the back side of the sheet using a thermal energy head. The method is the basic principle. By using a plurality of heat-sensitive transfer sheets of yellow, magenta, cyan, and, if necessary, black, it is possible to transfer two or more colors.

In the case of these color thermal transfer printers, there is a method of repeating thermal transfer three or four times.
There is a strong desire to increase thermal transfer efficiency in order to shorten thermal transfer time. However, according to the present invention, a photosensitive transfer sheet with improved thermal transferability can be obtained.

In the present invention, as the plastic sheet used for the substrate, a saturated polyester sheet is usually used, and condenser paper or the like is preferable because it is relatively inexpensive. As described above, a paper sheet such as a condenser paper is preferable in terms of the price of 1 meter, but a saturated polyester sheet is preferable in terms of the coatability of the heat-transferable ink layer. However, since the temperature of the thermal energy key head is as high as 400°C@Ft, the substrate made of these sheets or ribbons has a temperature of 20°C.
Exposure to high temperatures over 0.6c. At this temperature, heat transferable dyes penetrate considerably into these substrates. In particular, polyester-based Jugetsuji is known to be preferable as an image-receiving layer for sublimable and vaporizable dyes, and the thermal transfer efficiency to the image-receiving medium decreases due to penetration of the heat-transferable dye into the substrate at high temperatures. it seems to do.

In the present invention, it is believed that the penetration of the undesirable heat-transferable dye into the substrate due to heat is suppressed by the diffusion prevention layer, thereby improving the heat-transferability.

The composite material used in the diffusion prevention layer of the present invention is preferably a single layer of polymer that does not soften with heat (150° C. or higher), such as gelatin and gelatin derivatives such as phthalated gelatin, casein cap protein powder, agar, Polygels such as pullulan, water-soluble natural rubbers such as gum arabic,
Polyacrylamide, polyacrylic acids, polyimide I
ff fat, among others, gelatin and gelatin derivatives, pullulan, gum arabic, polyimide horse chestnut and the like are preferred. In addition to these polymer layers, gold scrap il
H%, for example, metal products such as aluminum can also be used as the diffusion prevention layer of the present invention. Further, stable polymers such as polyimide having a softening point of 400°C or higher are also useful as the diffusion prevention layer of the present invention.

The anti-diffusion layer of the present invention may have any thickness as long as it does not substantially thermally diffuse the ink, but preferably has a thickness of 0.5 μm or more, more preferably 1.0 μm or more. be.

The diffusion prevention layer of the present invention may also contain a stimulant or other additives.

Sublimation used in the present invention, outside the territory or '1% 22
'4 Transferable thermal transfer dyes include disperse dyes, salt-based dyes, acid dyes, and oil-soluble dyes, all of which can be used. For example, Kaya Set Yellow G (C2, ■,
Solvent Yellow 77] Kayase Sotre Sodo B
(C, ■, Disperse Red 60) Kayaset Red Blue 136 (C, R, Solvent Blue 36), etc. are used, but are not limited to these.

The ink layer containing the thermally transferable dye of the present invention preferably contains a binder, and various hydrophilic/hydrophobic synthetic or natural polymers are used, among which useful polymers include: 15+, 71 (Preferable are water-soluble polyvinyl butyral, polyvinyl alcohol, ethyl cellulose, cellulose acetate butyrate, etc.) Especially for oil-soluble dyes, water-bathable and hydrophilic polymers such as polyvinyl alcohol are preferred. , water-soluble polyvinyl butyral, etc. are preferred.

The present invention is also effective in the case of a solid heat-sensitive ink in which the ink layer is composed of wax and pigment.

As is clear from Table 1, the heat-sensitive transfer sheet of the present invention has superior transfer efficiency compared to the northern sample.
I≦ Edict (and 1 other person) -・L-Itozo Cneyama Masazu) (Spontaneous) March 1980 1111:1 Mr. Kazuo Wakasugi, Commissioner of the Patent Office 1. 1957 4th Temple, H'1 Application No. 229651-2,5'c Ming's name and benefits＼ Thermal transfer sheet]・3 Correcting layer・]Relationship with XI11 Applicant name (127) Konishiroku Photo Industry Co., Ltd. 4 Agent 〒105 6 fr7 by Sodemasa! /Ju number of inventions 7 Specification to be amended 11: (Detailed description of invention column) 8 Contents of amendment jE (Patent application 1987-229851)
Specification i4) will be amended as follows.

■ "Preferably" and "For example..." on page 5, line 3
Add the following between.

The analogy can be easily selected by testing as shown below.

[Test:] Applied thickness of one layer of test polymer of 2 g/m'.
1.46 g/m' of water-soluble polyvinyl butyral (1.46 g/m' of water-soluble polyvinyl butyral (nail mass 650, average content: J-33,000, butyralization 1i 9 mol%, degree of acetylation 12 moles) %,)
A layer is provided, in which a heat transferable hydrophobic dye 1-
Phenyl-2-naphthol8. OX 10 mol/m' was incorporated by alumina hole mill dispersion.

On top of this is the water-soluble polyvinyl butyral layer (2 g/m
') was used to prepare a transfer sheet. Then thickness 100
4 polyethylene terephthalate film? i-' In the drying test of hot pre-sink test (JIS LO850), the permeation density of 1-phenylazo-2-naphthol (blue with light) 1.2
A transfer image of ~1.3 is formed. Transfer sheet w-2
Remove the 01 dye layer with water, wash off the test polymer with a suitable melt, or peel it off with cellophane tape. The remaining one polyethylene terephthalate-based dye density was measured. The transmission density of 1-phenylamne-2-naphthol dyed into the support of the transfer sheet is preferably 0.1 or more, more preferably 0.03 or less. ly
Or the composition is preferable.

2 On page 6, 6th to 7th h, “Kayasen Trend Blue 1
``36'' is written as ``Kayascent Blue 136'' by Taeyama Tadashi.

3 Add the following sentence after the 4th line on page M59.

After the transfer, the dye layer and gelatin subbing layer of the heat-sensitive transfer sheet were removed with warm water, and the dyeing on the polyethylene terephthalate base was observed. In the samples with the Ceratin undercoat layer, no dye staining was observed, whereas in the samples without the Ceratin sublayer, dye staining was observed at around 0.2'-0.4 (in terms of transmission density). 1r was observed.

that's all

Claims (3)

[Claims] (1) In a thermal transfer sheet in which an ink layer containing a sublimable, vaporizable, or meltable thermal transferable dye is formed on a substrate, the thermal transferable dye is disposed between the ink layer and the substrate. A heat-sensitive transfer sheet that has a special feature of being provided with a diffusion prevention layer that does not substantially prevent heat diffusion. (2) The heat-sensitive transfer sheet according to claim 1, wherein the substrate is a polyester film or paper. (3) The heat-sensitive transfer sheet according to claim 1 or 2, wherein the diffusion prevention layer is a layer consisting essentially of gelatin and/or a gelatin derivative.