JPH0356676B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electrical transfer recording material, and more particularly to an electrical transfer recording material that can be transferred and recorded onto recording paper by thermal transfer at a low voltage of 100 V or less. It is something.

[Conventional technology]

In recent years, information has become extremely abundant, and the need for prompt transmission and recording of that information has increased, and various developments have been made regarding information management systems such as information processing systems, information transmission systems, and information recording systems. , an electric transfer recording system is also a typical example.

The present inventors have developed a metal-containing resin layer consisting of a resin matrix and metal powder, a conductivity imparting agent, and a resin matrix as a material that can be transferred and recorded on plain paper, etc. at low voltage without scattering carbon black or generating a bad odor. They have proposed an electrically conductive recording material in which a semiconductive resin layer and a conductive layer are laminated (Japanese Patent Application Laid-open No. 55-22917).

However, since the above-mentioned recording materials use carbon black, graphite, etc. as conductivity imparting agents, the recorded images are black or a color close to black, and even if colorants are added, it is not possible to obtain images with clear colors. .

[Problem that the invention seeks to solve]

It is an object of the present invention to make it possible to transfer and record clear colored images onto plain paper, etc., without scattering carbon black or generating bad odors, by conducting current recording at a low voltage. The object of the present invention is to provide an electrical transfer recording material that does not cause background smudge due to its pressure sensitivity.

[Means for solving problems]

The resin matrix used in the present invention only needs to have film-like properties and electrical insulation properties, and thermoplastic resins are preferably used. The above-mentioned thermoplastic resin is desirably one that has a high binding power to metal powder, etc., has high mechanical strength when molded into a sheet or film, is flexible, and has strong stiffness, such as polyethylene, polypropylene, polyester, etc. vinyl chloride, polyvinyl acetate,
Ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, polystyrene, polyacrylonitrile, polyvinyl acetal, polyacrylic ester, polymethacrylic ester, polyester, cellulose acetate, polyurethane, polyvinyl alcohol, carboxymethyl cellulose,
Examples include gelatin, and polyethylene, polyvinyl chloride, vinyl chloride-ethylene copolymer, vinyl chloride-vinyl acetate copolymer, polyvinyl acetal, cellulose acetate, and polyurethane are preferably used.

The metal powder used in the present invention means a metal in powder form, and the powder must have electrical conductivity. It is preferable to use a powder of a highly conductive metal, and specific examples of suitable metal powders include powders of copper, aluminum, iron, tin, zinc, nickel, molybdenum, silver, bronze, brass, and the like.

Further, metal powder coated with other metals can also be used, such as copper powder coated with silver. Among the metal powders mentioned above, copper, zinc, and iron are preferably used. The shape of the metal powder is preferably a dendritic one produced by electrolysis, and the particle size is preferably small and uniform, and the average particle size is preferably 0.2 to 20 microns, more preferably. is 0.5-10 microns.

Metal-containing resin layer (A) which is the first layer in the present invention
is a layer which is made of the above-mentioned resin matrix and metal powder and is not destroyed by discharge during current recording; one or more metal powders may be selected from among the above-mentioned metal powders as necessary; If the amount added is too small, the conductivity will be low, and conversely, if the amount added is too large, the conductivity will be too good and the current applied from the recording needle will spread and flow directly below the recording needle. The metal-containing resin layer 5.
~60% by volume and surface resistance of 10 ⁵ ~ 10 ¹⁶ Ω
and preferably 10 ⁷
~10 ¹⁴ Ω. Although the thickness of the layer is not particularly limited, it is preferably 5 to 50 microns.

The above-mentioned metal-containing resin layer (A) is used as an electrical transfer recording material, and when electrical recording is carried out, it is brought into contact with a recording needle and electrical recording is carried out, thereby eliminating the risk of the metal-containing resin layer causing cracks, etc., and preserving it. Plasticity, fillers, lubricants, stabilizers, antioxidants, flame retardants, etc. are added to improve properties, prevent the constituent substances from adhering to the recording needle, and further improve the formability of the layer. It's okay.

In the present invention, the conductive layer (B), which is the second layer, is a layer that is destroyed by discharge during current recording, and is laminated on the metal-containing resin layer (A), and when its surface resistance becomes small, it is destroyed by discharge. As it disappears, the calorific value decreases, and conversely, even if it increases and approaches the surface resistance of the metal-containing resin layer, ^the calorific value decreases. The ratio of the surface resistance of the contained resin layer (A) and the conductive layer (B) is
It is preferably 10 ² to 10 ¹⁵ . The conductive layer (B) may be formed by dispersing a conductivity imparting agent in a resin matrix, may be formed from a metal thin film, may be formed from a metal oxide thin film, or may be formed from a metal oxide thin film. Preferably, it is formed of a thin film.

The above-mentioned conductivity-imparting agent may have conductivity, such as carbon black, graphite, zeolite, zinc oxide, stannic oxide, metastannic acid, monocopper iodide, reduced titanium oxide, stannic oxide, etc. Iron or the like is preferably used. Also copper, aluminum, tin,
Metal powders such as molybdenum and silver are also preferably used. The conductivity imparting agent should have a small and uniform particle size, preferably an average particle size.
It is 10 microns or less. The amount of the conductivity imparting agent to be added may be determined so that the conductive layer (B) has a surface resistance of more than 1 Ω and less than 10 ⁴ Ω when dispersed in the resin matrix. Preferably, the amount is 10 to 1000 parts by weight per 100 parts by weight of the resin matrix, and the thickness is preferably 2 to 30 microns.

Also, when a metal thin film or a metal oxide thin film is used as the conductive layer (B), the surface resistance thereof should be greater than 1 Ω and less than 10 ⁴ Ω, and if the thickness is too thin, the surface resistance If the resistance is greater than 10 ⁴ Ω and if it is too thick, it will be difficult to break down due to discharge, so 90
The thickness is preferably 100-3000 angstroms, more preferably 200-2000 angstroms.
Examples of metals include aluminum,
Examples of metal oxides include silver, gold, copper, zinc, tin, nickel, and molybdenum, and examples of metal oxides include tin oxide, indium oxide, and chromium oxide.

In the present invention, the third layer, the heat-sensitive transfer layer (C), is a layer that is softened by heat and transferred to the recording medium during electrical recording, and is formed of a colorant and a binder.

Any known pigment or dye can be used as the coloring agent, such as nickel yellow, titanium yellow, cadmium red, naphthol yellow, permanent orange, crystal violet, malachite green, phthalocyanine blue, brilliant carmine 6B, etc. , the amount added may be arbitrarily determined depending on the color, density, etc. when recorded. Examples of the coloring agent for obtaining a black recorded image include carbon black, aniline black, and triiron tetroxide.

The binder may be the resin matrix described above, but since the layer (C) is thermally transferred, it is preferably one with a melting point of 50 to 110°C, such as paraffin wax or carnauba wax. ,
Examples include polyethylene wax, low molecular weight polystyrene and its derivatives, polyvinyl butyral, vinyl chloride-vinyl acetate copolymer, polyamide, polyurethane, ethylene-vinyl acetate copolymer, ketone resin, petroleum resin, and the like. Also, the thickness of the thermal transfer amount is 0.2 because the thicker it becomes, the more difficult it is to transfer.
Preferably it is ~15μ. Fourth in the present invention
The thermal transfer layer (D) is the third layer, the thermal transfer layer (C).
This layer is composed of a colorant and a binder, or only a binder, in a lower content than that of the third layer, and is transferred during electrical recording, and is a layer that is transferred during electrical recording.
(D) is laminated.

The above-mentioned colorant and binder may be the same as those used for the third layer, the heat-sensitive transfer layer (C), or may be different from those used, and may be selected from the above-mentioned materials. However, except in the case of dyes, pigments with a density such as black are preferably used in the same color system. To prevent pressure sensitivity due to recording stylus pressure, which is the purpose of the present invention, the amount of colorant added to the fourth layer, the heat-sensitive transfer layer (D), should be adjusted to the amount of colorant added to the third layer, the heat-sensitive transfer layer (C). must be reduced in comparison.

That is, when the amount of the third layer, the heat-sensitive transfer layer (C), is 100 parts by weight, the amount of the fourth layer, the heat-sensitive transfer layer (C), is preferably in the range of 0 to 50 parts by weight. The thickness of the layer (D) is desirably as thin as possible as long as it has the ability to prevent pressure sensitivity, and is preferably 0.1 to 10 .mu.m, more preferably 0.5 to 5 .mu.m, since the transferred image density will decrease if it becomes thicker.

The current transfer recording material according to the first aspect of the present invention has a four-layer structure as described above, and the second current transfer recording material according to the present invention has a structure in which between the conductive layer (B) and the heat-sensitive transfer layer (C), Furthermore, an insulating resin layer (E) is laminated to form a five-layer structure.

The above-mentioned insulating resin layer (E) is a layer that is mainly made of a resin matrix and is not destroyed by discharge during current recording, and it prevents the conductive layer (B) destroyed by discharge from being transferred, and also prevents the conductive layer (B) destroyed by discharge from being transferred. This is a layer that conducts the heat generated in the magnetic layer (B) to the layer to be transferred.The resin matrix forming the layer (E) is the resin matrix described above, but it is flexible and does not absorb the energy of discharge breakdown. It is preferable to use materials that have a buffering effect to absorb and have high strength when heated, such as polyvinyl petyral, ethylene-vinyl acetate copolymer, chlorinated polyvinyl chloride, styrene-butadiene rubber, styrene-isobrene rubber, etc. used for.

Further, in order to improve the thermal conductivity of the layer (E), a metal powder may be added, and the metal powder may be the metal powder described above, but it is preferable that the metal powder has excellent thermal conductivity and has a uniform particle size. Preferably, the powder is small and has low bulk and specific gravity, such as scale-like aluminum powder, dendritic copper powder, etc. When adding metal powder, it is necessary to provide an insulating property of 10 ⁸ Ω or more, since if the surface resistance becomes small, the recorded image will become unclear and will be destroyed by discharge together with the conductive layer (B).

Further, the layer (E) may be a single layer or may be composed of multiple layers, and when composed of multiple layers,
By using a flexible resin matrix on the conductive layer side (B) and a harder resin matrix with a higher melting point on the thermal transfer resin layer (C) side, a better effect can be obtained in preventing perforation of the layer (E).

The thickness of the layer (E) is preferably thin because it conducts heat as described above, but it is preferably 1 to 8 microns since it is necessary that it not be destroyed by electrical discharge.

The method for forming each of the layers described above is not limited in any way, and any known method such as a solution casting method, an emulsion casting method, a calendering method, an extrusion method, etc. may be employed.

Further, when forming the conductive layer (B) using a metal thin film and a metal oxide thin film, any known method may be employed, such as a vacuum evaporation method, an ion sputtering method, or the like.

The structure of the current transfer recording material of the present invention is as described above. When a recording paper such as paper or plastic film is placed under the thermal transfer layer (D) and electricity is applied to record, the conductive layer (B) directly under the recording needle is destroyed by discharge and generates heat, and this heat causes the two layers to The heat-sensitive transfer layers (C) and (D) are transferred to recording paper and recorded.

〔Effect of the invention〕

The structure of the current transfer recording material of the present invention is as described above, and since the electricity applied from the recording needle passes through the metal-containing resin without being diffused and is supplied to the conductive layer, a recorded image with excellent resolution can be obtained. It will be done. In this case, since current recording can be performed at a voltage lower than 100V, the number of recording needles can be increased, recording speed can be increased, and stability can be improved.

In addition, the metal-containing resin layer is not destroyed or changes even when energized and recorded, and since energized recording is performed at a low voltage, less soot and carbon black are generated during energized recording, and scattering can be suppressed. This prevents soot and carbon black from adhering to the recording stylus, reducing the troublesome maintenance of the recording stylus. Therefore, since soot and carbon black do not adhere to the recording needle, highly reliable and clear recording can be obtained. Furthermore, if the conductive layer is formed by vacuum evaporation or ion sputtering, it is very easy to manufacture and can be made very thin, making it easy to break down due to electrical discharge, resulting in high sensitivity and a large amount of heat generation. Highly reliable and clear records can be obtained.

Further, since a coloring agent is added to the heat-sensitive transfer layer, a colored image can be obtained. In particular, in the case of a recording material having a five-layer structure, since only the heat-sensitive transfer layer is transferred, a more vivid colored image can be obtained.

The recording material of the present invention is free from background stains caused by pressure sensitivity due to the pressure of the discharge recording needle, and can provide clear recorded images.

Further, the metal-containing resin layer does not generate any through holes and does not change even after discharge recording, so it can be used multiple times like carbon paper.

Therefore, the recording material of the present invention is suitable for use in facsimile machines, various measuring instruments, recorders, recording displays in computers, and the like.

〔Example〕

Next, examples of the present invention will be described. Hereinafter, the term "parts" simply means "parts by weight."

Example 1 Polyurethane resin (manufactured by Nippon Polyurethane Co., Ltd., trade name N-5109, 30% urethane, 70% dimethylthylformamide) 100 parts Electrolytic copper powder (average particle size 2.0μ) 50 parts Methyl ethyl ketone 110 parts The above composition was mixed into a glass Apply it on the board, dry it, and thicken it.
A 12μ metal-containing resin sheet was obtained. The electrolytic copper powder was 18.2% by volume in the sheet. Also, the surface resistance is 0.5×
It was 10 ¹⁰ Ω.

Aluminum was vacuum-deposited over the entire surface of the obtained sheet under conditions of 3×10 ⁻⁵ Torr to form a conductive layer with a thickness of 400 Å and a surface resistance of 2.0 Ω.

Ketone resin (manufactured by Honshu Kagaku Co., Ltd., trade name Halon 80)
100 parts metal-containing dye (manufactured by Hodogaya Chemical Co., Ltd., trade name Spiron Black BNH) 25 parts ethyl acetate 50 parts toluene 25 parts beeswax 15 parts carnauba wax 15 parts Next, the above composition was coated on the conductive layer with a gravure coater. It was coated and dried to provide a 2μ thick heat-sensitive transfer layer.

Ketone resin (manufactured by Honshu Kagaku Co., Ltd., trade name Halon 80)
100 parts Beeswax 15 parts Carnauba wax 15 parts Ethyl acetate 50 parts Toluene 25 parts The above composition was further applied with a gravure coater and dried to form a heat-sensitive transfer layer with a thickness of 1μ.
A 15μ electrical transfer recording material was obtained.

The obtained recording material was fed to an improved mimeograph paper making machine (manufactured by Gestetner GmbH, Gestfax 1100), high-quality paper was brought into contact with the bottom of the heat-sensitive transfer layer, and the recording needle was pressed onto the metal-containing resin sheet with a stylus force of 10 g. When we contacted them and applied DC 40V electricity and recorded the electricity under the conditions of a scanning line density of 12/mm and a recording speed of 1.2 m/sec, there was no scattering of soot or aluminum powder, almost no odor, and there was no metal-containing resin sheet. A clear black image was obtained on the high-quality paper without any through-holes. At this time, no stains other than those caused by scanning lines were observed on the high-quality paper, and the image density was 1.15.

Comparative example In Example 1, the thickness of the third thermal transfer layer was
When a 15μ thick electrical transfer recording material with a thickness of 3μ and the fourth layer removed was recorded under the same recording conditions as above, a dark image with an image density of 1.20 was obtained, but traces of scanning lines were visible on the high-quality paper. The ground was so dirty that the image was unclear.

Example 2 A polyurethane resin (manufactured by Nippon Polyurethane Co., Ltd., product name N-5109) was prepared by casting and drying the following composition to provide an insulating resin layer with a thickness of 3μ between the second and third layers of Example 1. , 30% urethane, 70% dimethylformamide) 100 parts Methyl ethyl ketone 150 parts The obtained electrical transfer recording material with a total thickness of 17μ was fed to the mimeograph paper plate making machine used in Example 1, and the stylus pressure was 12g, the recording voltage was 45V, Recording speed 1.2m/
sec, scanning line density of 12/mm, there was no scattering of soot or aluminum powder, no bad odor, no through holes in the metal-containing resin sheet, and a clear black color on high-quality paper. A great image was obtained. At that time, no soiling of the high-quality paper was observed, and the image density was 1.20.

Claims (1)

[Scope of Claims] 1. A laminate having a four-layer structure, wherein (A) the first layer is made of metal powder and a resin matrix, the metal powder accounts for 5 to 60% by volume, and the surface resistance is 10 ⁵ ~10 ¹⁶ Ω, a metal-containing resin layer that is not destroyed by discharge during current recording; (B) the second layer has a surface resistance of more than 1 Ω,
10 ⁴ Ω or less and is destroyed by discharge during current recording; (C) The third layer is a heat-sensitive transfer layer consisting of a colorant and a binder; (D) The fourth layer is more 1. An electrical transfer recording material comprising a heat-sensitive transfer layer consisting of a colorant and a binder with a small content or only a binder, which are laminated in the above order. 2. The electrical transfer recording material according to claim 1, wherein the conductive layer is a metal thin film. 3. A laminate having a five-layer structure, wherein (A) the first layer is made of metal powder and a resin matrix, the metal powder accounts for 5 to 60% by volume, and the surface resistance is 10 ⁵ to 10 ¹⁶ Ω. , a metal-containing resin layer that is not destroyed by discharge during current recording; (B) the second layer has a surface resistance of more than 1Ω;
10 ⁴ Ω or less and is destroyed by discharge during current recording; (C) The third layer is an insulating resin layer mainly composed of a resin matrix and is not destroyed by discharge during current recording; (D) The third layer is an insulating resin layer that is not destroyed by discharge during current recording. (E) A thermal transfer layer in which the 4th layer consists of a colorant and a binder; (E) The 5th layer consists of a colorant and a binder in a lower content than the 4th layer, or only a binder. An electrical transfer recording material comprising thermal transfer layers laminated in the above order. 4. The electrical transfer recording material according to claim 3, wherein the conductive layer is a metal thin film. 5. The electrical transfer recording material according to claim 3 or 4, wherein the insulating resin layer has a surface resistance of 10 ⁸ Ω or more.