JPH0566877B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a thermal transfer material. More specifically, the present invention relates to a thermal transfer material that prevents the thermal transfer sheet from being damaged during recording by providing an abrasion-resistant and heat-resistant protective layer on the thermal transfer sheet used for thermal recording.

(Prior Art) With the development of office automation, thermal transfer recording methods have been incorporated into various terminal devices such as facsimile machines and printers. In this recording method, a heat-melt transfer material coated with heat-fusible ink or a transfer material coated with heat-sublimable dye is layered on recording paper such as plain paper, and the image is transferred by heating from a thermal head. Recording is performed by transferring ink etc. from the material to the recording paper. Those that use a recording needle instead of a thermal head (for example, JP-A-58-220793) and those that use electrode terminals (for example, JP-A-55-17521)
Publication No.) etc. are known.

In the recording method using a thermal head, the heat generated from the thermal head passes through the support and melts the thermal transfer ink, thereby transferring the ink to plain paper, etc., so the ink layer melts, but it is not possible to transfer the ink to a material such as plastic film. It is necessary that the support (base film) does not melt. However, in order to speed up recording, increase the amount of heat applied to the thermal head to record on recording paper with a rough surface, and increase the pressure applied,
By making the thermal head more sharply protruding, the amount of heat and pressure applied to the base film increases significantly, which may eventually damage the base film. As a result, if the damaged support adheres to the thermal head, satisfactory recording will not be possible, and
Problems such as damage to the head may occur and normal recording may not be possible. Such a phenomenon is generally called a stick phenomenon.

In addition, when using a recording needle or electrode terminal instead of a thermal head, unlike a thermal head, significant heat is not applied to the base film, but significant impact is applied due to discharge or current flow phenomena, which may cause damage. .

Conventionally, in order to improve this sticking phenomenon, there has been a method of applying heat-resistant resin or the like to the lower surface of the base film as shown in Japanese Patent Publication No. 58-13359 and Japanese Patent Application Laid-open No. 58-187396. −155794,
JP-A-59-196291 and JP-A-57-74195 disclose a method in which a lubricant or a surfactant is mixed into a photocurable resin and applied, but the method is not satisfactory and the lubricant If the thermal transfer material is stored in high temperature and humidity, the lubricant or surfactant may adhere to the ink layer during long-term recording. This may cause problems such as not being able to record properly.

(Problems to be Solved by the Invention) As a result of intensive research into methods to improve the above-mentioned drawbacks, the inventors of the present invention have found that the problem of damage to the base film during recording does not occur, and even during long-term recording, foreign particles can be trapped in the thermal head. We have completed a thermal transfer material that does not adhere, can withstand storage under high temperature and humidity, and has a stagnation prevention layer that does not interfere with the thermal conductivity of the ink layer.

[Structure of the invention]

(Means for Solving the Problems) That is, the present invention provides a thermal transfer material in which a thermal transferable ink layer is provided on a base film, in which a film of chlorinated polyolefin resin is provided on the back surface of the base film. This is a unique thermal transfer material.

The chlorinated polyolefin resin in the present invention refers to chlorinated polyethylene, chlorinated polypropylene, chlorinated polyisobutylene, chlorinated ethylene vinyl acetate copolymer, and these chlorinated polyolefins and other polymerizable monomers such as acrylic and styrene. There is a copolymer with the body.

The above-mentioned chlorinated polyolefin resin can be applied by a conventionally known method and then dried with hot air to form a film.

In this case, other resins include acrylic resin, polyester, melamine resin, epoxy resin, ketone resin, rosin resin, alkyd resin, phenolic resin, silicone resin, cellulose resin such as cellulose acetate butyrate, nitrocellulose, cellulose acetate, etc. It can also be used in combination with resins such as fluororesins such as vinylidene chloride, polyvinyl alcohol resins, urethane resins, polyacetal resins, polycarbonate resins, polyimide resins, polyvinylcarbazole resins, and rubber resins such as chlorinated rubber and cyclized rubber. can. Furthermore, it is also possible to use additives together. Additives include metal powder, titanium white, carbon black, calcium carbonate, barium sulfate, and other inorganic additives.
These include organic additives such as silicone oil and fluororesin powder.

As the support used in the present invention, a conventionally known base film can be used. For example, polyester film (polyethylene terephthalate,
These include polyethylene naphthalate, etc.), polyamide films (nylon, etc.), polyolefin films (polypropylene, etc.), cellulose films (triacetate, etc.), and polycarbonate films. Polyester film is most preferred because it has excellent heat resistance, mechanical strength, tensile strength, tensile stability, and the like. The thinner this support is, the better the thermal conductivity is, but from 3 μm to 3 μm due to strength and ease of applying the ink layer
5μ is most preferred.

Furthermore, conventionally known inks can be used as they are for the ink layer. Examples of such inks include paraffin wax, carnauba wax,
Ink colored with dyes or pigments can be used using waxes such as wood wax and beeswax as a binder.

According to the present invention, an abrasion-resistant and heat-resistant protective layer is provided on the back side of the base film provided with the ink layer. This protective layer has a thickness of about 0.01μ to several μ,
Preferably it is 0.1μ to 5μ.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Note that "parts" in the examples are "parts by weight."

(Example) Example 1 6μ polyester film (base film)
Coating liquid A with the following composition was applied using a gravure coater to a dry film thickness of 0.5 μm, and heated at 80°C.
It was dried with hot air. An ink layer containing carnauba wax as a main component and colored with carbon black was applied to the back side of the substrate using a bar coater while heating. The thickness of the ink layer was 3.2 μm. On the other hand, a thermal transfer sheet without a protective layer was also prepared in the same manner.

Coating liquid A Chlorinated polypropylene (Super Chron 406 manufactured by Sanyo Kokusaku Pulp Co., Ltd.) 18 parts Toluene 82 parts Comparative example 1 Coating liquid B having the following composition was applied in the same manner as in Example 1,
A heat-sensitive transfer sheet was prepared by providing the same ink layer as in Example 1 on the other side of the base film that had been dried with hot air.

Coating liquid B Nitrocellulose resin (manufactured by Asahi Denka, alcohol-less NCH-1/2) 50 parts Fluorine surfactant (manufactured by Mitsubishi Metals, EF-103) 1 part ethyl acetate 25 parts toluene 25 parts Example 1 and comparative example A printing test was conducted using a thermal head using the transfer sheet No. 1.

The printing test is continuous for 10 minutes with constant energy, 10
Ten cycles were performed, with one minute rest being one cycle.
The energy level was varied from 1.3 mj/dot to 3.0 mj/dot by changing the voltage applied to the thermal head and the pulse width.

The transfer sheet provided with the protective layer of Example 1 is
Even when the energy was increased from 1.0mj/dot to 3.0mj/dot, the printing was not disturbed at all. In addition, in a 10-cycle printing test, even at an energy of 3.0 mj/dot, no welding of the base film to the thermal head or adhesion of foreign matter was observed. Of course, no melting and damage of the base phenol was observed. On the other hand, the thermal transfer sheet of Comparative Example 1 had irregular printing at 2.0 mj/dot.
Fusion to the thermal head occurred at 3.0 mj/dot.
Furthermore, with a thermal transfer sheet without a protective layer, printing began to become distorted at 1.2 mj/dot, and at 1.3 mj/dot, the thermal head base film was fused and the base film was also damaged and melted. Further, in the thermal transfer sheet of Comparative Example 1, no sticking phenomenon occurred at an energy of 1.5 mj/dot, but a lot of foreign matter adhered to the thermal head during a 10-cycle printing test, and printing omissions occurred.

Hereinafter, a protective layer was formed on the base material in the same manner as in Example 1, and a thermal transfer sheet provided with an ink layer was similarly prepared and compared with a thermal transfer sheet without a protective layer. In addition, in Example 3, instead of the heat-melting ink containing carnauba wax as the main component in Example 1, an ink containing a sublimable dye having the following composition was applied to a thickness of 2.3 μm using a bar coater. and dried with hot air. A thermal transfer sheet without a protective layer was also made in a similar manner.

Sublimation transfer ink composition Kayasettoretsudo B (manufactured by Nippon Kayaku) 10 parts Cellulose acetate propionate 15 parts Silica gel 2 parts Methylol melamine 1 part Xylene 73 parts The thermal transfer material provided with the protective layer in all examples has excellent printability and thermal properties. The sticking phenomenon to the head, the adhesion of foreign matter, the melting of the base film after printing, and the state of damage were significantly better than when no protective layer was provided.

The main components of the coating liquid used for the protective layer are as follows (the diluting solvent is omitted).

Example No. Chlorinated polyolefin 2 Chlorinated ethylene vinyl acetate copolymer (Super Chron manufactured by Sanyo Kokusaku Pulp Co., Ltd.)
BL) 3 Chlorinated polyethylene (Super Chron manufactured by Sanyo Kokusaku Pulp Co., Ltd.)
LT) 4 Chlorinated polypropylene (Super Chron manufactured by Sanyo Kokusaku Pulp Co., Ltd.)
602) 5 Chlorinated polyethylene (Adekaprene CR-40 manufactured by Asahi Denka Kogyo Co., Ltd.) (Effects of the invention) The thermal transfer material of the present invention does not melt the base film even when the amount of heat of the thermal head increases, and can be used for a long period of time. There is no foreign matter adhering to the thermal head even in recording, and there is almost no heat loss due to the protective layer, so clear printing can be obtained even at high printing speeds, making it suitable for high-speed printing. It is possible.

Claims (1)

[Claims] 1. A thermal transfer material comprising a thermal transferable ink layer provided on a base film, characterized in that a film of chlorinated polyolefin resin is provided on the back surface of the base film.