JPH0729484B2 - Electric thermal transfer recording material - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an electric heat-sensitive transfer recording material, and more particularly to a material for transferring a heat-sensitive transfer layer by heat generated by energizing at a low voltage for recording.

[Conventional technology]

In recent years, information has become remarkably abundant, and the need for rapid 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. The electric transfer recording system is also a typical example.

Among them, energization thermal transfer recording in which electricity is applied from a recording needle and transfer recording is performed by heat generated by the electricity has advantages such as increasing recording speed and obtaining a clear recorded image, and many proposals have been made. Has been done. For example, in a recording material composed of a resistance layer and a thermal transfer layer, the resistance layer is composed of polycarbonate and carbon black (Japanese Patent Publication No. 57-193), polyimide and carbon black (Japanese Patent Publication No. 58-110283), polyurethane and carbon. Proposals have been made such as consisting of black (Japanese Patent Publication No. 59-2631).

However, the resistance layer using polycarbonate or polyimide as the binder has the drawback of being too hard and brittle, and easily broken by bending, and the resistance layer using polyurethane as the binder is soft and stretchable. It has a drawback that it is easy to use because it is easy to use.

[Problems to be solved by the invention]

In view of the above-mentioned drawbacks, the object of the present invention is that the resistance layer has high heat resistance, large tensile strength, etc., hardness is appropriate, brittleness is small, and elongation is appropriate, and workability during recording is good, An object of the present invention is to provide an electrically conductive thermal transfer recording material capable of obtaining a clear image.

[Means for solving problems]

The vinyl chloride resin used in the present invention has a degree of polymerization of 1000 to 3500 selected from the group consisting of vinyl chloride resin and vinyl chloride-vinyl acetate copolymer.

When the degree of polymerization of the vinyl chloride resin decreases, mechanical strength such as tear strength and impact strength of the resistance layer (A) when conductive powder is added decreases, and when the degree of polymerization increases, the compatibility with nitrile rubber increases. And since the film-forming property is lowered, it is limited to 1000 to 3500. Since the vinyl chloride-vinyl acetate copolymer becomes tacky and becomes weaker as the vinyl acetate content increases, it is preferably 15% by weight or less.

The conductive fine powder used in the present invention is selected from the group consisting of carbon black and graphite, and it is preferable that the shape is small and the particle size is uniform, and the particle size is preferably 10 microns or less.

The resistance layer (A) in the present invention comprises 100 parts by weight of a mixture of the above vinyl chloride resin and nitrile rubber, and conductive fine powder 5 to 300.
This layer is composed of parts by weight and has a surface resistance of 30 to 10 ⁶ Ω and generates heat without being destroyed by discharge during energized recording.

If the amount of nitrile rubber added is small, the mechanical strength of the resistance layer (A) will decrease when the conductive fine powder is added, and conversely, if it is large, the resistance layer (A) will become softer and easier to expand. It is preferable to add ˜100 parts by weight. Since the mechanical strength increases as the degree of polymerization of the vinyl chloride resin increases, the amount of nitrile rubber added can be reduced.

If the amount of conductive fine powder added is too large, the conductivity will become too good, and the current given from the recording needle will diffuse, making it difficult for the current to flow directly below the recording needle, and the amount of heat generated will decrease. Since it becomes small and discharge breakdown occurs, 5 to 300 parts by weight is added to 100 parts by weight of the mixture of vinyl chloride resin and nitrile rubber, and the surface resistance is 30 to 10 ⁶
Ω, and preferably 10 to 170 parts by weight.

Although the thickness of the layer is not particularly limited, it is preferably 2 to 50 μm.

The method for forming the resistance layer (A) is not limited at all, and any known method such as a solution casting method, an emulsion liquid casting method, a calender method, an extrusion method may be employed.

In the present invention, the conductive layer (B) is a layer that is not destroyed by discharge during current recording, and is laminated on the resistance layer (A).
If the surface resistance is too small, the heat generation amount of the resistance layer (A) will be small, and conversely, if it is large, the resistance layer (A) will be destroyed when energized. Further, if the difference in surface resistance between the resistance layer (A) and the conductive layer (B) is small, the amount of heat generated when electricity is recorded is reduced, so that the surface resistance of the resistance amount (A) and that of the conductive layer (B) are reduced. The surface resistance ratio is preferably ⁵ to 10 ⁵ . The conductive layer (B) is formed of a metal thin film, and when the thickness is thin, the surface resistance is greater than 20Ω, and when it is thick, the surface resistance is less than 0.1Ω.
It is preferably set to 00 to 5000 angstroms, preferably 500 to 3000 angstroms, and more preferably 600 to 2000 angstroms. And as the metal, for example, aluminum, silver, gold, copper, zinc, tin,
Nickel, molybdenum and the like can be mentioned, and aluminum is preferably used.

Any method may be adopted as the method for forming the conductive layer (B), and examples thereof include a vacuum deposition method, an ion plating method, and an electroless plating method. If there is a minute defect or pinhole in the metal thin film, the current concentrates on that portion during current application and discharge breakdown easily occurs. Therefore, in order to eliminate the above defect or pinhole, two layers are formed by the above method. The conductive layer (B) is preferably formed by stacking the above metal thin films.

The heat-sensitive transfer layer (C) in the present invention is a layer composed of a binder and a colorant and having a surface resistance of 10 ² Ω or more, which is transferred by heat during energization recording. ) Is stacked.

Any resin matrix can be used as the binder, but since the layer is thermally transferred, the melting point is 50%.
Those having a temperature of up to 110 ° C. are preferable, for example, paraffin wax, carnauba wax, polyethylene wax, low molecular weight polystyrene and its derivatives, polyvinyl butyral, vinyl chloride-vinyl acetate copolymer, polyamide,
Examples thereof include polyurethane, ketone resin, ethylene-vinyl acetate copolymer, petroleum resin and the like.

As the colorant, any known pigment or dye can be used, for example, nickel yellow, titanium yellow, cadmium red, naphthol yellow, permanent orange, crystal violet, malachite green,
Examples thereof include phthalocyanine blue and brilliant carmine 6B, and the addition amount thereof may be arbitrarily determined depending on the color, density, etc. at the time of recording. To obtain a black recorded image, carbon black, aniline black, iron tetroxide, etc. may be added.

When the surface resistance of the heat-sensitive transfer layer (C) becomes small, the current applied to the resistance layer (A) diffuses and a clear image cannot be obtained. Therefore, it is necessary to have 10 ² Ω or more. Care must be taken when using a colorant having equal conductivity, and when the surface resistance is less than 10 ² Ω, it is preferable to use a colorant having conductivity and a colorant having no conductivity in combination. .

Further, when the heat-sensitive transfer layer (C) contains a large amount of a coloring agent, the recording material may be contaminated with the coloring agent when the recording material of the present invention is laminated on the recording paper and electrically recorded. Because there is
The heat-sensitive transfer layer is preferably formed of two or more layers, and the outermost layer preferably contains a small amount of a colorant.

The thickness of the layer (C) is preferably 0.5 to 20 .mu., More preferably 1 to 10 .mu., Because thermal transfer becomes difficult as the layer becomes thicker.

The method for forming the heat-sensitive transfer layer (C) is not particularly limited, and examples thereof include a solution casting method, an emulsion casting method, a calendar method, an extrusion method, and a gravure printing method.
When the heat-sensitive transfer layer is formed like a net by the gravure printing method,
A return electrode can be provided on the transfer layer side when conducting recording with electricity, and a uniform and stable recorded image can be obtained as compared with the case where the return electrode is provided on the resistance layer, which is preferable.

[Action]

The structure of the electrically conductive thermal transfer recording material of the present invention is as described above, and the recording material is supplied to a discharge or an electrically conductive recording device,
When a recording meter is brought into contact with the resistance layer and recording paper such as paper or plastic film is brought into contact with the heat transfer layer underneath to record electricity, heat is generated in the resistance layer immediately below the recording, and this heat causes the heat transfer layer to become recording paper. It is transcribed and recorded.

〔The invention's effect〕

The constitution of the current-carrying thermal transfer recording material of the present invention is as described above, the resin forming the resistance layer is a chloride having a polymerization degree of 1000 to 3500 selected from the group consisting of vinyl chloride resin and vinyl chloride-vinyl acetate copolymer. Since it is a mixture of vinyl resin and nitrile rubber, the resistance layer can be easily formed into a film even if a large amount of conductive fine powder is added, and the mechanical strength such as tensile strength, tear strength and impact strength is large, The brittleness is small and the elongation is appropriate. Therefore, the mechanical strength of the recording material is large, and the workability and the feeling of electricity are good without breakage during recording, the resistance layer peeling from the conductive layer, or cracking. Thermal transfer recording is possible.

In addition, since electricity can be applied and recorded in a wide range of a low voltage of less than 100 V, the number of recording needles can be increased and the recording speed can be increased. Further, the resistance layer and the conductive layer do not change due to discharge destruction even when energized recording is performed, and since energized recording is performed at a low voltage, no medium or odor is generated during recording. Further, similar to the conventional electric discharge recording, the recording can be performed at a higher speed than the thermal transfer recording, and a reliable and clear recording having an image density similar to that of the thermal transfer recording can be obtained. Therefore, the recording material of the present invention is suitably used for printing out facsimiles, various measuring instruments, recorders, recording displays on computers and the like.

Moreover, the recording material of the present invention is not limited to black recording,
Since it does not cause turbidity in color recording, it is extremely effective for high-speed printout of color recording display.

〔Example〕

Next, examples of the present invention will be described. Below, simply “part”
"Parts by weight" means "parts by weight".

Example 1 Vinyl chloride resin (polymerization degree: 3200) 100 parts Nitrile rubber (manufactured by Zeon Corporation, trade name NIPPON 1432)
J) 30 parts Furnace Black (Lion Akzo, trade name Ketjen Black EC) 50 parts Tetrahydrofuran 1400 parts The above composition is dissolved and dispersed, cast on a glass plate and dried at 100 ° C for 15 minutes. Thus, a resistance sheet having a thickness of 15μ was obtained. The surface resistance of the sheet was 12 × 10 ³ Ω. Aluminum was vacuum-deposited twice on one surface of the obtained sheet under the condition of 3 × 10 ⁻⁵ Torr to form a conductive layer having a thickness of 800 Å and a surface resistance of 0.6Ω to obtain a composite sheet.

Ketone resin (Honshu Chemical Co., Ltd., trade name Halon 80) 100 parts Metal-containing dye (Hodogaya Chemical Co., Ltd., Spiron Black BN
H) 25 parts Ethyl acetate 50 parts Toluene 25 parts Beeswax 15 parts Carnauba wax 25 parts Next, the composition having the above composition is dissolved and dispersed, and applied on the conductive layer of the above composite sheet with a gravure coater and dried to a thickness. A 4 μm heat sensitive transfer layer was formed to obtain an electrically conductive heat sensitive transfer recording material having a thickness of 19 μm. Surface resistance of thermal transfer layer is 0.5 × 10
It was ¹⁴ .

The obtained recording material was slit into a ribbon shape with a width of 7 mm, supplied to an electric recording device (manufactured by IBM Corp., which is an improved product name Quiet Writer), and a high-quality paper was contacted under the thermal transfer layer to form a resistance sheet. When the recording needle was brought into contact with the top and electricity of DC 15V, 20mA was applied to record electricity, there was no scattering of medium or carbon black, no foul odor, no through hole in resistance sheet, and cutting during recording. A clear black image was obtained on the high-quality paper. The image density obtained was 1.35. When the recording material was subjected to a tensile test at a speed of 100 mm / min, the breaking strength was 650 g / 7 mm width.

Example 2 Vinyl chloride-vinyl acetate copolymer (polymerization degree 1250, vinyl acetate content 5% by weight) 100 parts Nitrile rubber (Nippon 1432, trade name, manufactured by Nippon Zeon Co., Ltd.)
J) 30 parts graphite (Nippon Graphite Co., Ltd., earth graphite ASP average particle size 3.0
μ) 100 parts Methyl ethyl ketone 1400 parts The formulation having the above composition was dissolved and dispersed, cast on a glass plate and dried at 100 ° C. for 15 minutes to obtain a resistance sheet having a thickness of 15 μ. The surface resistance of the sheet was 0.9 × 10 ³ Ω. A conductive layer and a heat-sensitive transfer layer were formed on one surface of the obtained sheet in the same manner as in Example 1 on the resistive layer of the composite sheet obtained in Example 1 to obtain a 19 μm-thick electrothermal transfer recording. Got the material.

When recording was performed in the same manner as in Example 1 using the obtained recording material, a medium and carbon black were not scattered, no bad odor was generated, and no clear holes were formed in the surface sheet. Was obtained.

The image density obtained was 1.30. The recording material is 100 mm /
When the tensile test was performed at a speed of min, the breaking strength was 620 g / 7 mm width.

Comparative example Vinyl chloride resin (polymerization degree 830) 100 parts Nitrile rubber (manufactured by Nito Zeon Co., Ltd., product name NIPPON 1432)
J) 30 parts Furnace Black (manufactured by Lion Akzo, trade name Ketjen Black EC) 50 parts Tetrahydrofuran 1200 parts A resistance sheet was obtained in the same manner as in Example 1 using the composition having the above composition, and Example 1 A conductive layer and a heat-sensitive transfer layer were formed in the same manner as described in 1. to obtain an electrically conductive heat-transfer recording material having a thickness of 19 μm. The surface resistance of the resistance sheet is 1.1 × 10 ³
It was Ω.

Using the recording material thus obtained, electric recording was carried out in the same manner as in Example 1 and only an unclear image was obtained due to cutting during recording. The image density of the dark portion was 0.85. When the tensile test was performed at a speed of 100 mm / min, the breaking strength was 430 g / 7 mm width.

Claims (2)

[Claims] 1. A laminate having a three-layer structure, comprising: (A) a vinyl chloride resin having a polymerization degree of 1000 to 3500 selected from the group consisting of a vinyl chloride resin and a vinyl chloride-vinyl acetate copolymer, and a nitrile. 100 parts by weight of a mixture of rubber and 5 to 300 parts by weight of conductive fine powder selected from the group consisting of carbon black and graphite, having a surface resistance of 30 to 1
A resistance layer of 0 ⁶ Ω, which generates heat without electric discharge recording during electric recording; (B) a conductive layer which is made of a metal thin film and has a surface resistance of 0.1 to 20 Ω and which is not electric discharge damaged during electric recording; (C) A heat-sensitive transfer recording material comprising a binder and a colorant, a heat-sensitive transfer layer having a surface resistance of 10 ² Ω or more, and laminated in the above order. 2. The heat-sensitive transfer recording material according to claim 1, wherein the ratio of the surface resistances of the resistance layer (A) and the conductive layer (B) is 5 to 10 ⁵ .