JPS6223789A - Transfer body for thermal recording - Google Patents

Abstract

PURPOSE:To provide a picture wherein recording density is uniform, by a method wherein the elongation rate in the lateral direction of a biaxial orientation film as a substrate provided with a coloring material layer on one surface is made to be larger 1.2 times or above than the elongation rate in the longitudinal direction thereof. CONSTITUTION:The material of a biaxial orientation film used as a substrate of a transfer body is not limited in particular, but ester high molecules are especially useful therefor. When the elongation rate in the lateral direction of said film is larger 1.2 times or above than the elongation rate in the longitudinal direction thereof, the slippage of dots due to the elongation in recording is reduced, and therefore the uniformity in recording density is improved considerably. Provision of a lubrication heat-resistive layer on the back surface (the surface contacting with a thermal head) of such a substrate produces an effect that the elongation is curbed still more. The lubricative heat-resistive layer is formed at least of minute particles, a surfactant and a high-molecule substance. A coloring material layer is not limited in particular, and a variety of compositions of coloring material layers used in a waxing system, a subliming dye system, etc. for instance, can be used therefor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a transfer body for thermal recording used for recording by thermal transfer, and particularly to a transfer body that is effective when recording by changing the running speed of the transfer body and image receiving body. It is related to the base material.

In conventional thermal transfer recording, capacitor paper and polymer film are used as base materials for transfer bodies, but recently polymer films have been increasingly used.

The polymer film used is a biaxially stretched film, and a typical example is a biaxially stretched polyethylene terephthalate (hereinafter abbreviated as PET) film.

This typical PET film is generally manufactured with a higher stretching ratio in the transverse direction than in the longitudinal direction, so that the elongation ratio in the longitudinal direction is higher than that in the transverse direction. larger than

Problems to be Solved by the Invention When a biaxially stretched film, typified by this PET film, is used in a recording method in which the traveling speed of the transfer body is slower than the speed of the image receptor to reduce the amount of transfer body used, Since the transfer member and the image receiver are pressed between the platen roller and the thermal head, the transfer member is pulled by the image receiver during recording, and further heat is applied, which increases the elongation of the transfer member. As a result, an image with non-uniform recording density results due to the difference in elongation of the transfer member.

An object of the present invention is to obtain a transfer member that provides an image with uniform recording density by using a film that does not elongate even when heated.

A solution to the problem is that a coloring material layer is provided on one side of a base material, the base material is a biaxially stretched film, and the elongation rate in the transverse direction of the biaxially stretched film is equal to the elongation rate in the machine direction. The transfer material has a rate of 1.2 times or more.

Effect: By increasing the stretching ratio in the longitudinal direction further than before and making the elongation rate in the longitudinal direction 1/1.2 times or less than the elongation rate in the horizontal direction, the elongation of the transfer material base material during recording is significantly increased. It can be suppressed.

Examples The material of the biaxially stretched film used as the transfer body base material of the present invention is not particularly limited. For example, ester polymers such as polyethylene terephthalate, polyethylene naphthalate, and polycarbonate, acetylcellulose,
Cellulose derivatives such as cellophane, amide polymers such as nylon and aromatic polyamide, imide polymers such as polyetherimide, etc. can be used. Ester polymers are particularly useful.

The elongation rate of the film in the horizontal and vertical directions (longitudinal direction) is J
This is the value determined by IS C231B-1975. That is, the elongation rate is calculated by the following formula and expressed as the average value of 5 samples.

L-L.

Elongation rate (%) =. ×100 where LO: Gauge distance L before test: Gauge distance at cutting If the elongation rate in the horizontal direction is 1.2 times or more than the elongation rate in the longitudinal direction, dots due to elongation during recording. As a result, the uniformity of recording density is significantly improved.

The elongation rate is measured at room temperature and humidity (generally at a temperature of 20°C).

The value at a humidity of 60% PH) corresponds well to the tendency of elongation during heating recording when used as a base material for a transfer member.

Providing a slippery heat-resistant layer on the back surface (contact surface with the thermal head) of such a base material has the effect of further suppressing elongation. The slippery heat-resistant layer is composed of at least a surfactant such as fine particles and a polymeric substance.

The material of the fine particles is not particularly limited and may be metal.

Various inorganic and organic particles can be used.

Especially synthetic amorphous silica, carbon black, alumina,
Titanium oxide, calcium silicate, aluminum silicate, etc. are promising. The addition ratio of fine particles to polymeric substance is 1
~200% by weight is suitable.

As the surfactant, various anionic surfactants, various cationic surfactants, various nonionic surfactants, various amphoteric surfactants, various fluorosurfactants, various silicone surfactants, etc. can be used. . Especially polyether modified silicone oil, carboxyl modified silicone oil,
Various modified silicone oils such as alkyl aralkyl polyether modified silicone oil and epoxy/polyether modified silicone oil are excellent.

The material of the polymeric substance is not particularly limited, and examples thereof include various thermoplastic resins, heat, and light.

Various types of curable resins cured by electron beam or the like can be used.

Examples include silicone resins, epoxy resins, unsaturated aldehyde resins, urea resins, unsaturated polyester resins, alkyd resins, furan resins, oligoacrylates, and the like.

In particular, oligoacrylate cured resins exhibit excellent properties. Examples of oligoacrylates include polyol acrylate, polyester acrylate, and epoxy acrylate.

Urethane acrylate, silicone acrylate.

There are acrylates and the like that have a spiroacetal structure.

The coloring material layer is not particularly limited, and various coloring material layer configurations used in wax methods, sublimation dye methods, etc. can be used.

The coloring material layer may be formed directly on the biaxially stretched film, or may be formed on the anchor coat layer after providing the anchor coat layer.

More specific details will be given below.

The elongation rate in both the vertical and horizontal directions is 80%.

Biaxially oriented PET film (thickness.

9 μm) was used as a base material, and the following coating liquid was applied to the lower surface of this base material, the solvent was dried, and ultraviolet rays were irradiated to form a slippery heat-resistant layer with a thickness of 2 μm.

Coating liquid epoxy acrylate resin 20 parts by weight 2-hydroxy-2-methylpropiophenone
1 part by weight stearyl stearate 1 part by weight silicone oil
0.4 parts by weight A42036 parts by weight Methylene chloride 100 parts by weight Next, 2 parts by weight of a sublimable dye represented by the following molecular structure, 4 parts by weight of polycarbonate, 4 parts by weight of titanium oxide, and 100 parts by weight of methylene chloride were added. The ink mixed with the cup was applied with a wire bar and then dried to create a transfer body.

This transfer member and activated clay coated paper were sandwiched between a platen and a thermal head, and recording was performed under the following recording conditions, with the transfer member traveling speed being H, which is the same as the image receiving member traveling speed.

Main and sub-scanning dot density: 4 dots/MM Recording power: 0.7 W/Dot head heating time 2 ms Recording area
2. Mu 6 version As a result, since the base material of the transfer member hardly elongated, an image with uniform recording density was obtained.

(Comparative example) The elongation rate in both the vertical and horizontal directions is 130%.

100% normal PET film (thickness, 9μm)
was used as a base material, and the lower and upper surfaces of this base material were subjected to the same treatment as in the example to prepare a transfer body. As a result of evaluation using this transfer member and activated clay coated paper under the same conditions as in the example, the material of the transfer member was elongated significantly, resulting in an uneven image with shading.

Effects of the Invention According to the present invention, a transfer member that provides an image with uniform recording density can be obtained by using a film that does not elongate even when heated.

Claims (2)

[Claims] (1) A coloring material layer is provided on one surface of a base material, the base material is a biaxially stretched film, and the elongation rate in the horizontal direction of the biaxially stretched film is 1.2 with respect to the elongation rate in the longitudinal direction. Transfer material for thermal recording that is more than twice as large. (2) The transfer body for heat-sensitive recording according to claim 1, wherein a slippery heat-resistant layer is provided on the other surface of the base material.