JPH064357B2 - Transfer material for thermal recording - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal recording transfer member used for transferring a color material by heat application to obtain a recording, and more particularly to improvement of a substrate.

Conventional structure and its problems As a typical thermal transfer material, a wax method in which the color material layer is composed of a heat-fusible material and a sublimation dye method in which the color material layer contains a sublimable dye I have a body. Each of the color hard copies obtained from these transfer bodies has a characteristic color, and particularly the latter has a characteristic that it is easy to reproduce the halftone of the color and is beautiful. However, much heat energy is required to sublimate or evaporate the dye as compared with the former method. For example, when a polyester film, which has been put to practical use in the wax system and is not so heat-resistant, is used in the sublimation dye system, thermal energy (hereinafter simply referred to as “head”) is applied to a thermal head to obtain a required recording density. When added, a phenomenon called a stick occurs in which the polyester film adheres to the head. Also in the case of the wax system, the same phenomenon occurs when high heat energy is applied to the film to increase the recording speed.

Conventionally, this phenomenon is considered to be that the substrate is softened or melted by heat and adheres to the head.
For example, JP 55-7467 A or JP 5
As described in Japanese Patent Laid-Open No. 5-105579, it has been proposed to improve the heat resistance of the substrate by forming a heat resistant protective film on the surface of the substrate that contacts the head.

However, as a result of various studies according to the above proposal, in order to effectively use the heat-resistant protective film, it is not effective unless the film thickness is increased, and the thicker the film, the more thermal energy applied to the substrate. For example, it contains the contradiction that the energies reaching the color material layer cannot be the same. Furthermore, the stick phenomenon is not completely eliminated by simply forming the heat resistant protective film.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional drawbacks and to provide a thermal recording transfer member in which the stick phenomenon does not occur even if a substrate having poor heat resistance is used.

According to the present invention, a coloring material layer is provided on one surface of a substrate, and a polymer composition comprising at least one of a liquid lubricant and a liquid interface lubricant and a cured resin is provided on the other surface of the substrate. , The curing resin is an oligoacrylate light or electron beam curing resin,
Alternatively, it is a transfer member which is a photocurable resin of an epoxy resin using an aromatic diazonium salt catalyst.

The presence of at least one of the liquid lubricant and the liquid interface lubricant between the head and the base facilitates heat conduction,
Also, since the space charge released from the substrate by the heat of the head or the charge generated by friction is reduced, the running frictional resistance between the head and the substrate is significantly reduced, and in combination with a specific cured resin having excellent heat resistance. By using such a compound, it is possible to obtain a transfer member free from stick phenomenon.

Description of Examples Examples of the present invention will be described below.

The present invention does not mean that the stick phenomenon is caused by the fact that the substrate is softened or melted by the heat of the head and adhered to the head, as has been conventionally considered and announced.
The space charge in the substrate is intensely emitted to the vicinity of the surface by the high heat of the head (detected as a thermal stimulation current), and static electricity is superposed due to running friction between the substrate and the head. It was noted that the attraction to the head made it impossible to run, and as a result, the phenomenon that the substrate adhered to the head occurred, which is the essence of what is called a stick until now. That is, as is conventionally said, instead of sticking because the base softens or melts, the base is held for a long time (stick) on the heating element of the head mainly by static electricity, and heat pulses are repeatedly repeated at the same position. As a result of the addition of heat and the accumulation of heat in the substrate, the substrate softens or melts. Therefore, the present invention has a basic feature in removing the heat-stimulated electric charge and reducing the running friction between the head and the substrate, and includes a liquid lubricant or a liquid surfactant or both as a means thereof. The polymer composition is formed on a substrate.

The liquid lubricant or liquid surfactant used in the present invention is a substance effective in reducing the friction coefficient between the head and the polymer composition or preventing or removing the generation of static electricity.

Liquid lubricants are substances that are liquid and slippery at 25 ° C. and 1 atm, and include, for example, silicone type such as methyl silicone and phenyl silicone, alcohol type such as glycerin and ethylene glycol, liquid paraffin, mineral oil, various synthetic oils and the like. is there.

Further, the following solid or semi-solid lubricants can be used in combination with the liquid lubricant or the liquid surfactant. For example, microcrystalline wax, natural and synthetic wax, polyolefin wax and partial oxides thereof, or aliphatic hydrocarbons such as fluorides and chlorides thereof.

Stearic acid, hydroxystearic acid, capric acid,
Fatty acids such as lauric acid, palmitic acid and brassic acid.

Fatty acid amides such as caproic acid amide, caprylic acid amide, capric acid amide, palmitic acid amide, oleic acid amide, erucic acid amide, and ethylenebisstearic acid amide. Of the various metals represented by M (OOCR) n (where M represents a metal and R represents a hydrocarbon group) as a basic structure of calcium stearate, aluminum stearate, calcium laurate, etc. which are usually called metal soaps. Higher fatty acid salt system.

Carbon number 1 such as stearyl alcohol and cetyl alcohol
Alcohols such as 5 or more monohydric alcohols, polyglycols, polyglycerol pentaerythritol, and polyhydric alcohols such as sorbitol.

A fatty acid ester system such as stearic acid monoglyceride, oleic acid monoglyceride, lauric acid sorbitan ester, stearyl stearate, pentaerythritol tetrastearate, butyl stearate, and phospholipid.

Liquid surfactants are liquid surfactants at 25 ° C. and 1 atm, and examples thereof include various anionic surfactants such as carboxylates, sulfonates, sulfate ester salts, and phosphate ester salts, and aliphatic quaternary surfactants. Various cationic surfactants such as ammonium salt, aromatic quaternary ammonium salt, and heterocyclic quaternary ammonium salt, ether type such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene glycerin fatty acid ester, poly Ether ester type such as oxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, ester type such as fatty acid monoglyceride, sorbitan fatty acid ester, nitrogen-containing type such as fatty acid alkanolamide, polyoxyethylene fatty acid amide, polyoxyethylene alkylamine, etc. Seed nonionic surfactants, various betaine type, aminocarboxylic acid salt, various amphoteric surfactants such as imidazoline derivatives, various fluorine surface active agent,
There are various silicone-based surfactants such as copolymers of silicone and polyoxyalkylene glycol. Also included in the present invention are surfactants that are liquid at 25 ° C. and 1 atmospheric pressure, which are referred to as polymeric surfactants, organometallic surfactants, reactive surfactants, and the like. Liquid lubricants and liquid surfactants, when they are liquids, show particularly excellent effects by themselves in reducing the friction coefficient or preventing the generation of static electricity. Further, the effects thereof can be further enhanced by using a plurality of each, or by using both in combination or in combination with a solid lubricant, a solid surfactant or the like.

The substrate is not particularly limited, and various film sheets or the like can be used. For example, polyethylene terephthalate, a polyester-based polymer such as polycarbonate, an amide-based polymer such as nylon, a cellulose-based polymer such as acetyl cellulose and cellophane, polyvinylidene fluoride, tetrafluoroethylene-6-fluoropropylene copolymer, Examples include fluorine-based polymers such as fluororesins, polyether-based polymers such as polyoxymethylene and polyacetal, olefin-based polymers such as polypropylene and methylpentene polymer, and imide-based polymers such as polyimide and polyetherimide. Especially, polyethylene terephthalate is useful because it is thin and can be used as a general-purpose product and has heat resistance to some extent. The curable resin of the polymer composition is a light or electron beam curable resin of oligoacrylate, or a photocurable resin of an epoxy resin using an aromatic diazonium salt catalyst. These cured resins have strong adhesion to the substrate and exhibit good characteristics, and also have a particularly excellent curing rate, so that a long transfer body can be easily produced.

Examples of the aromatic diazonium salt catalyst include allyldiazonium hexafluorophosphate, allyldiazonium fluoroborate, and allyldiazonium hexafluoroantimonate. The thickness of the polymer composition shows good characteristics from a formable thickness of 0.1 μm or less, and of course shows good characteristics at any thickness of 0.1 μm or more. The color material layer has a structure in which a color material and a binder or, if necessary, various additives are added. Particularly, in order to reduce the influence of static electricity when the transfer member is running, it is desirable to add a surfactant having excellent antistatic properties.

Coloring materials include color formers as well as colored pigments and dyes.

When a sublimable dye that starts sublimation or evaporation at a temperature of 300 ° C. or less is used for the color material, it exhibits an excellent function for reproducing halftone image quality. As the sublimable dye, for example, a basic dye,
A disperse dye or the like can be used.

Hereinafter, it will be described more specifically.

Example 1 A polyethylene terephthalate (hereinafter abbreviated as PET) film having a thickness of 4.5 μm was used as a substrate. The color material layer is
An ink having the following composition was applied to the upper surface of this substrate with a wire bar, and then dried with hot air (60 ° C.).

(Color material layer ink composition) 2 parts by weight of the dye having the following molecular structure (A) 4 parts by weight of polycarbonate 100 parts by weight of methylene chloride Also, after coating the coating shown in the following table on the lower surface of the substrate, A transfer body was prepared by curing (film thickness 1 μm). The polyester acrylate resin in the paint was a resin (viscosity, 8,000 centipoise) represented by the following molecular structure (B). After coating and drying, the coating was further irradiated with a high-pressure mercury lamp of 2 Kw to be cured. Recording was performed under the following thermal head recording conditions using activated clay coated paper as the recording paper.

Cotton density in main and sub scanning: 4 dots / mm Recording power: 0.7 w / dot Head heating time: 2-8 ms (gradation recording) or 8 ms (solid recording) In addition, the present invention similarly showed good characteristics for a substrate in which a polymer layer was undercoated under a coloring material layer. Various additives such as a lubricant and a surfactant may be added to the polymer layer.

EFFECTS OF THE INVENTION As described above, since the transfer material for heat-sensitive recording of the present invention does not show sticking phenomenon at all even for high heat energy recording, it has a low heat resistance such as polyester film which has hitherto been unusable for high heat energy recording. Films can also be used, and the versatility and thin film characteristics of these films can be utilized. As a result, the recording density, the clarity of the recorded image, and the industrial use are dramatically improved.

Front page continuation (72) Inventor Osamu Hotta 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Tokihiko Shimizu 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Invention Nobuyoshi Taguchi No. 1006 Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd. (56) References JP-A-56-155794 (JP, A) JP-A-57-129789 (JP, A) JP-A-58-171992 (JP, A)

Claims (4)

[Claims] 1. A color material layer is provided on one surface of a substrate, and a polymer composition comprising at least one of a liquid lubricant and a liquid interface lubricant and a cured resin is provided on the other surface of the substrate, A thermal recording transfer material, wherein the curable resin is a light or electron beam curable resin of oligoacrylate, or a photocurable resin of an epoxy resin using an aromatic diazonium salt catalyst. 2. The thermal recording transfer member according to claim 1, wherein the substrate is polyethylene terephthalate. 3. The heat-sensitive recording transfer member according to claim 1, wherein the color material of the color material layer is a sublimable dye. 4. The thermal recording transfer member according to claim 1, wherein the color material layer contains a surfactant.