JPH0729485B2 - 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, the energization thermal transfer recording in which the recording needle is energized and the transfer recording is performed by the heat generated by the electricity can increase the recording speed. There are advantages such as obtaining clear recorded images, and many proposals have been made. 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 surface layer (A) in the present invention comprises 100 parts by weight of a mixture of vinyl chloride resin having a degree of polymerization of 1000 to 3500 and nitrile rubber, and 5 to 250 parts by weight of conductive fine powder, and has a surface resistance of 10 ² to 10 ^2.
It is a layer that is ⁷ Ω and is not destroyed by discharge when energized. The above vinyl chloride resins are vinyl chloride resin and vinyl chloride-
It is selected from the group consisting of vinyl acetate copolymers, and when the degree of polymerization thereof becomes small, the mechanical strength such as tear strength, impact strength, etc. of the surface layer (A) when conductive fine powder is added decreases. However, since the compatibility with nitrile rubber and the film-forming property decrease as the degree of polymerization increases, 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.

When the amount of nitrile rubber added is small, the mechanical strength of the surface layer decreases when the conductive fine powder is added, and conversely, when it is large, it becomes soft and easy to stretch, so vinyl chloride resin 100
It is preferable to add 20 to 200 parts by weight to 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.

The conductive fine powder is preferably selected from the group consisting of carbon black and graphite, and has a small shape and a uniform particle size, and the particle size is preferably 10 microns or less.

If the amount of conductive fine powder added to the vinyl chloride resin increases, the conductivity becomes too good and the current given from the recording needle diffuses, making it difficult to transmit to the resistance layer (B) immediately below the recording needle. If the amount is too small, the conductivity will be small and discharge breakdown will occur. Therefore, the conductive fine powder is 5 to 2 parts with respect to 100 parts by weight of the mixture of vinyl chloride resin and nitrile rubber.
50 parts by weight is added, and the surface resistance is 10 ² to 10 ⁷ Ω.

The thickness of the surface layer (A) is not particularly limited, but 5
It is preferably from 50 to 50 μm, and the forming method is not limited at all, and any known method such as solution casting method, emulsion casting method, calendering method, extrusion method, etc. may be adopted. Good.

The resistance layer (B) in the present invention is composed of a thermoplastic resin and conductive fine powder and has a surface resistance of 30 to 10 ³ Ω, which is smaller than the surface resistance of the surface layer (A). It is a layer that generates heat without being destroyed by discharge. The thermoplastic resin is a urethane resin, a vinyl chloride resin, a vinyl acetate resin, a vinyl chloride-ethylene copolymer, a vinyl chloride-vinyl acetate copolymer, an ethylene-vinyl acetate copolymer, a vinyl acetal resin, a polyacrylic ester, It is selected from the group consisting of polymethacrylic acid ester and cellulose acetate.

The conductive fine powder used in the surface layer (A) is used as the conductive fine powder, and if the amount of addition is large, the conductivity becomes too good and the current given from the recording needle diffuses, resulting in the recording needle. It becomes difficult to flow directly below, and the amount of heat generation becomes small, and conversely when it becomes small, the conductivity becomes small and discharge breakdown occurs.
It is added in an amount of 0 to 400 parts by weight so that the surface resistance becomes 30 to 10 ³ Ω.

If there is no difference in the surface resistance between the surface layer (A) and the resistance layer (B), the current supplied to the surface layer (A) is less likely to be transmitted to the resistance layer (B). Is larger than that of the resistance layer (B), and the surface layer (A)
The ratio of the surface resistance of the resistance layer (B) to that of the resistance layer (B) is preferably 5 to 10 ³ .

The thickness of the resistance layer (B) is not particularly limited, but 2
It is preferably ~ 50 microns.

The method for forming the resistance layer (B) is not limited at all, and for example, the same method as the method for forming the surface layer (A) may be adopted.

In the present invention, the conductive layer (C) is a layer that is not destroyed by discharge during current recording, and is laminated on the resistance layer (B).
If the surface resistance is too small, the heat generation amount of the resistance layer (B) becomes small, and conversely, if it becomes large, the resistance layer (B) will be destroyed when energized. Further, if the difference in surface resistance between the resistance layer (B) and the conductive layer (C) is small, the amount of heat generated will decrease when the recording is carried out, so that the surface resistance of the resistance layer (B) and the conductive layer (C) will decrease. The surface resistance ratio is preferably 10 to 10 ⁴ . The conductive layer (C) is formed of a metal thin film, and when the thickness is thin, the surface resistance is greater than 50Ω, 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 of forming the conductive layer (C), 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 energization, and discharge breakdown easily occurs. Therefore, in order to eliminate the defect or pinhole, two or more layers are formed by the above method. It is preferable to form the conductive layer (C) by laminating the metal thin films of.

The heat-sensitive transfer layer (D) in the present invention is composed of a binder and a colorant, has a surface resistance of 10 ² Ω or more, and is a layer which is transferred by heat at the time of 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 (D) becomes small, the current applied to the surface 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 smaller 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 (D) contains a large amount of colorant, the colorant may contaminate the recording material 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 (D) is preferably 0.5 to 20 .mu., More preferably 1 to 10 .mu., Because thermal transfer becomes difficult as the layer (D) becomes thicker.

The method for forming the heat-sensitive transfer layer (D) is not particularly limited, and examples thereof include a solution casting method, an emulsion casting method, a calender 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 during recording by energization, 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 constitution of the electric heat-sensitive transfer recording material of the present invention is as described above, and the recording material is supplied to a discharge or electric recording apparatus,
When a recording meter is brought into contact with the surface layer, and recording paper such as paper or plastic film is brought into contact with the thermal transfer layer underneath to record electricity, heat is generated in the resistance layer immediately below the recording, and this heat causes the thermal transfer layer to become recording paper. It is transcribed and recorded.

〔The invention's effect〕

The constitution of the current-carrying heat-sensitive transfer recording material of the present invention is as described above, and since the surface layer is composed of a mixture of vinyl chloride resin and nitrile rubber and conductive fine powder, heat resistance, tensile strength is large, and hardness is appropriate. The brittleness is small, the elongation is appropriate, the surface layer of the recording material is not peeled off or cracked, and the electric heat-sensitive transfer recording can be performed with good workability.
In addition, since the surface layer having a surface resistance larger than that of the resistance layer is laminated on the resistance layer, the electricity supplied to the surface layer flows toward the conductive layer directly below the recording needle without being diffused. With this, a recorded image with high accuracy can be obtained.

Further, since the voltage of the electricity to be applied can be applied and recorded in a wide range of low voltage lower than 100 V, the number of recording needles can be increased and the recording speed can be increased. Further, the resistance layer, the conductive layer and the surface layer are not destroyed by discharge and do not change even when current is recorded, and since current 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 used for facsimiles, various measuring instruments,
It is preferably used for printing out recording needles and recording displays on computers.

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 Co., trade name Ketchen Black EC) 30 parts Tetrahydrofuran 1400 parts Dissolve and disperse the composition having the above composition, cast on a glass plate, and dry at 100 ° C for 15 minutes. Thus, a surface sheet having a thickness of 15μ was obtained. The surface resistance of the sheet was 1.5 × 10 ⁴ Ω.

Polyurethane resin (manufactured by Nippon Polyurethane Co., trade name Nippon Polan 5109, urethane 30%, dimethylformamide 70
%) 100 parts Crosslinking agent (manufactured by Nippon Polyurethane Company, trade name Coronate L,
Isocyanate 75%) 110 parts Graphite (Nippon Graphite Co., Ltd., trade name Soil Graphite ASP, average particle size 3.0μ) 40 parts Methyl ethyl ketone 150 parts The composition having the above composition is dissolved and dispersed and cast on the above surface sheet. After drying at 100 ° C. for 15 minutes, a resistance layer having a thickness of 5 μ was formed to obtain a two-layer sheet having a thickness of 20 μ. The surface resistance of the resistance layer was 1.2 × 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 0.1Ω 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 15 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 24 μm. Surface resistance of thermal transfer layer is 0.5 × 10
It was ¹⁴ . The obtained recording material was cut into a ribbon with a width of 7 mm, supplied to an electric recording device (manufactured by IBM Corp., which is an improved version of the Quiet Writer product), and a fine paper was contacted under the heat-sensitive transfer layer to form a surface sheet. Touch the recording needle on top, and
When electricity was recorded by applying electricity of V and 20 mA, a clear black image was obtained on the high-quality paper without cutting the recording material. The image density obtained was 1.40.

Example 2 Vinyl chloride resin (polymerization degree: 3200) 100 parts Nitrile rubber (manufactured by Nippon Zeon Co., Ltd., trade name NIPPON 1432)
J) 30 parts Graphite (Nippon Graphite Co., Ltd., trade name Soil Graphite ASP, average particle size 3.0μ) 70 parts Citrahydrofuran 1400 parts The composition having the above composition is dissolved and dispersed, and cast on a glass plate, It was dried at 100 ° C. for 15 minutes to obtain a topsheet having a thickness of 15μ. The surface resistance of the sheet was 2.5 × 10 ⁴ Ω. Using the obtained sheet, a resistance layer, a conductive layer and a heat-sensitive transfer layer were laminated in the same manner as in Example 1 to obtain a heat-transfer current-transfer recording material.

Using the obtained recording material, electricity was applied at 20 V and 20 mA in the same manner as in Example 1 to perform energization recording. As a result, a clear black image was obtained on the high-quality paper without cutting the recording material. . The image density obtained was 1.38.

Claims (3)

[Claims] 1. A laminate having a four-layer structure, comprising: (A) a vinyl chloride resin having a degree of polymerization 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 250 parts by weight of conductive fine powder selected from the group consisting of carbon black and graphite and having a surface resistance of 10 ² to
Surface layer of 10 ⁷ Ω which is not destroyed by electric discharge when energized; (B) Urethane resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-ethylene copolymer, vinyl chloride-vinyl acetate copolymer, ethylene-acetic acid 100 parts by weight of a thermoplastic resin selected from the group consisting of vinyl copolymer, vinyl acetal resin, polyacrylic acid ester, polymethacrylic acid ester and cellulose acetate, and a conductive fine particle selected from the group consisting of carbon black and graphite. Powder 20
Consists to 400 parts by weight, or less than the surface resistance of the surface layer to a surface resistance of 30~10 ³ Ω (A), the resistance layer generates heat not discharged destroyed during energization recording; (C) a metal thin film And a conductive layer which has a surface resistance of 0.1 to 20 Ω and is not destroyed by discharge during energization recording, and (D) a binder and a colorant, and a thermal transfer layer having a surface resistance of 10 ² Ω or more, An electrically conductive thermal transfer recording material characterized by being 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 surface layer (A) and the resistance layer (B) is 5 to 10 ³ . 3. A resistive layer (B) and the current sensitive transfer recording material of claim 1 wherein the range of the ratio of the surface resistance 10 to 10 ⁴ in which claims the conductive layer (C).