JPH01145193A - Electrothermal transfer recording material - Google Patents

Abstract

PURPOSE:To enhance mechanical strength, heat resistance and image fixing properties by providing a thin metallic film layer on one side of a conductive resin film, providing thereon a plurality of heat-fusible release layers comprising a wax and an ethylene-vinyl acetate copolymer, and providing a thermally transferable ink layer thereon. CONSTITUTION:A base 1 comprises a base film 11 and a thin metallic film layer 12 provided as a conductive layer, whereas an ink layer 2 comprises at least a first heat-fusible release layer 21, a second heat-fusible release layer 25 and a thermally transferable ink layer 22. A resistance layer 11 comprises a conductive resin film, particularly a film comprising conductive carbon black dispersed in an aromatic polyamide. The metallic layer 12 comprises a vapor- deposited aluminum layer, whereas the release layer 21 comprises carnauba wax, paraffin wax. an ethylene-vinyl acetate copolymer or the like, and the release layer 25 comprises paraffin wax, polyethylene wax, the above-mentioned copolymer or the like. A transfer layer 22 comprises a coloring material and a styrene, the above-mentioned copolymer or the like.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a recording material for electrical transfer, and more specifically,
Noiseless Typewriter - 1 This invention relates to a recording material for electrical transfer that is useful for printing records such as computer printing, computer output, and records of photocopying and transmission.

[Prior Art] Various recording materials for electrical transfer have been proposed so far. To give some examples, JP-A-54-58511 discloses a recording material (non-impact printing ribbon) consisting of a two-layer structure of a transfer layer and a resistance layer containing polycarbonate resin and conductive carbon black. is proposed. However, the heat distortion temperature of the polycarbonate resin used as a component of the resistance layer is 120 to 130.
℃, some of it adheres to the stylus during recording, reducing printing quality and, in turn, shortening the life of the stylus.

In JP-A No. 5 [11-93585], the resistance layer is composed of a polyimide carbon layer and a SiC layer, but since a film of sufficient strength cannot be formed with only these resistance layers, a carrier that also serves as a conductive layer is used. For this reason, expensive stainless steel with a thickness of about 5 μm is used. However, the problem is that the dot quality is not good.

Also, JP-A-59-120494 and JP-A-59
The recording material for electrical transfer disclosed in Publication No. 120495 has a three-layer structure consisting of a resistive layer (base layer), an intermediate layer and an alternating layer (ink layer), or the intermediate layer is composed of a resin component and carbon. There was a problem in that the recording voltage was as high as 100 to 200 V because the resistance could not be made sufficiently low.

In addition, these known techniques almost commonly have the defect that they are easily affected by the surface smoothness of the recording medium (transfer paper, etc.), making it difficult to obtain a sufficiently good dot shape.

[Information] The present invention was made in view of the above problems, and its main purpose is to have excellent mechanical strength and heat resistance, as well as image stabilization, and to be able to record with less recording energy than before. In addition, it is not affected by the smoothness of the surface of the transfer paper and can obtain a sufficient dot shape even if the surface smoothness is low, prolonging the life of the stylus, and enabling low-voltage driving. The goal is to provide recording materials.

[fiIt Composition] The recording material for electrical transfer of the present invention has a metal thin film layer provided on one side of a conductive resin film, and a plurality of heat-melting release layers made of wax and ethylene-vinyl acetate copolymer on the metal thin film layer. This is a recording material for electrical transfer, in which a heat-transferable ink layer is further provided via this heat-melting peeling layer.

By the way, the present inventors have conducted various studies on recording materials for electrical transfer, and have found that by adopting the structure described above, recording can be performed with less recording energy than before, and there is no problem with the transfer paper. It was confirmed that the dot shape is not easily affected by the smoothness of the surface, and even if the surface has a low degree of smoothness, a sufficient dot shape can be obtained, and furthermore, the image does not fall off. The present invention has been made based on this.

As before, the recording material of the present invention is placed overlapping a recording body, a return electrode is brought into contact with this recording material, and a recording electrode needle (stylus) is brought into contact with the surface of the recording material, and a voltage is applied to record. It can be used in an electrical transfer recording method in which a material is energized to transfer ink onto the recording medium.

The present invention will be explained in more detail below. FIG. 1 shows the basic layer structure of the recording material for electrical transfer of the present invention. The base material 1 of the recording material of the present invention is a resistive layer (base film)
11 and a metal thin film layer 12 as a conductive layer. ) consists of three layers. As explained later, transfer □ layer 2
If necessary, an attractive layer may be provided on 2, and in that case, it is desirable that a recording material for electrical transfer is provided. While the resistance layer 11 is required to have high heat resistance and mechanical strength, it is important that it be thin from the viewpoint of thermal efficiency, ease of handling, and economic efficiency.

In order to satisfy heat resistance and mechanical strength with a thin base film, a conductive resin film is used in the present invention, and it is particularly advantageous to use a film in which conductive carbon black is dispersed in aromatic polyamide. .

For aromatic polyamides, for example, Japanese Patent Application Laid-Open No. 53-35797
Those described in the above publication can be used.

That is, the aromatic polyamide used in the present invention has the general formula % (however, ArH1Ar2 and Arz are both divalent aromatic groups, and they may be the same or different. , a halogen atom or the like may be substituted into an aromatic group in order to improve solvent solubility and processability). Specifically, poly(m-phenylene isophthalamide), poly(m-phenylene terephthalamide), poly(p-phenylene isophthalamide), poly(p-phenylene terephthalamide), poly(
Typical examples include poly(4,4°-oxydiphenylene terephthalamide), poly(4,4°-oxydiphenylene isophthalamide), poly(m-benzamide), and poly(p-benzamide). Among them, poly(m-phenylene isophthalamide), poly(m-)
Unishin terephthalamide) is useful when forming a film using a wet method (casting method) because it is soluble in many solvents and can be dissolved at high temperatures.

Suitable examples of the solvent include dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and the like.

The metal thin film layer 12 as a conductive layer has the function of lowering the resistance level of the recording material, prolonging the concentration of current, and reducing crosstalk, enabling sharp recording with low voltage and low recording energy. It is for a table. There are methods such as ion sputtering and ion blating to provide the metal thin film layer 12 on the base film 11, but from an industrial perspective, the most excellent method is the vacuum evaporation method under a vacuum of 104 to' Torr. There is.

As the metal thin film layer 12, an aluminum vapor deposition layer is suitable.

As described above, the ink layer 2 is composed of at least three layers: the first heat-melt release layer 21, the second heat-melt release layer 25, and the transfer layer 22. Both the first heat-melting release layer 21 and the second heat-melting release layer 25 are layers that melt due to heat, lose mechanical strength, and facilitate peeling of the transfer layer 22. Incidentally, the first heat-fusible release layer 21 is a layer that melts with low energy and vines, and the second heat-fusible release layer 25 is a layer that, when melted, becomes the transfer layer 22.
This is a layer that improves the sharpness of the transfer layer 22 without being mixed into the transfer layer 22.

The transfer layer (thermal transferable ink layer) 22 contains a coloring material, is softened by heat, and has an adhesive property (bridge-transferring to the unevenness of the recording medium and covering the depressions).

The first thermofusible release layer 21 has a melting point of 40 to 90°C;
Preferably melt viscosity at 55-80°C is 50c at 120°C
A wax of ps or less is used. Examples include natural waxes such as candelilla wax, carnauba wax, and rice wax, and petroleum waxes such as rose-in wax and microcrystalline wax. Further, in order to improve adhesion to the adhesion modifier and the metal thin film layer 12, an ethylene-vinyl acetate copolymer that is compatible with these low melt viscosity substances is used.

The second thermofusible release layer 25 has a melting point of 100 to 140.
A wax having a melt viscosity of 140°C or more loocps at a temperature of preferably 110 to 130°C is used.

Examples include petroleum waxes such as paraffin wax and microcrystalline wax, and synthetic waxes such as polyethylene wax and polypropylene wax.

Further, as an adhesion modifier, an ethylene-vinyl acetate copolymer which is compatible with these low melt viscosity substances is used.

In addition, in order to improve storage stability at high temperatures, a release layer may be formed using a substance that is difficult to mix with the transfer layer 22, or a substance that provides supercooling properties to suit recording conditions (for example, It is also effective to add 1,3-diphenoxy-2-propatool).

The transfer layer 22 uses a well-known hot-melt transfer ink material, but in order to perform recording that is not affected by the smoothness of the surface of the recording medium, a resin component is added more than in conventional formulations. It is desirable to have a large amount of liquid, not to become a very low viscosity liquid when heated, and to have a certain degree of mechanical strength. The transfer layer 22 that meets these requirements is made of a coloring material and a styrene resin, an ethylene-vinyl acetate copolymer, an ethylene-(meth)acrylic copolymer, or a polyamide resin, which are conventionally used as main ingredients for hot melt adhesives. A material whose main component is a heat-softening resin that has been widely used is used.

A suitable amount of wax, polyethylene wax, or the like may be added to this transfer layer 22 in order to further improve thermal sensitivity and fixation of prints on the recording medium.

As mentioned above, an adhesive layer 23 is preferably provided on top of the thermally transferable ink layer 22 (FIG. 2). Adhesive layer 23
This is a beneficial layer because it facilitates the peeling of the transfer layer 22 and improves image fixation on a recording medium (such as a recording paper).

A thermoplastic resin is used for this adhesive layer 23, and preferably has a melting point or softening point of 70 to 140°C.

These include acrylic resin, methacrylic resin, styrene resin, vinyl acetate resin, vinyl chloride resin, vinylidene chloride resin, petroleum resin, novolak resin, olefin resin,
Examples include polyester resins, polyacetal resins, and copolymers containing these monomers.

Note that a coloring material may be added to the adhesive layer 23 with the intention of improving the print density on the recording medium.

In fact, in order to produce the recording material of the present invention, conductive carbon black is first wet-dispersed in a resin, particularly an aromatic polyamide, using a solvent such as dimethylformamide or dimethylacetamide, and then a film is formed by a casting method.

A metal thin film layer (preferably aluminum is vapor-deposited under a vacuum of 104 to 10' Torr) is formed on the obtained film base material (conductive resin film), and on this metal thin film layer,
The first and second release layers and transfer layer may be sequentially provided by a hot-melt method or a solvent coating method using toluene, xylene, alcohol, or the like as a solvent. Moreover, as shown in FIG. 2, if necessary, a layer 23 in contact with the transfer layer 22 may be provided, and a release paper may be provided on the surface of this layer 23, as described above (FIG. 2).

The thickness of each layer of the recording material to be manufactured is such that the resistance layer 11 has a thickness of 2 to 1.
5 μm2 preferably 4 to 10 μm1 metal thin film layer 12 is 4
0 to 200 nm, the first peeling layer 21 is 1 to 5 μm, the second
The peeling layer 25 is 0.5 to 3 μm, the transfer layer 22 is 3 to 10
The μm1 adhesive layer 23 is about 0.5 to 5 μm.

As shown in FIG. 3, the recording material of the present invention also includes a heat-softening or heat-melting layer made of wax, resin, etc. on the transfer layer 22 to further improve the recording properties. 5
A surface layer 24 of ~5 μm may be provided.

In order to perform current transfer recording using the recording material for current transfer produced in this way, for example, as shown in FIG. A recording electrode 41 and a return electrode 42 are brought into pressure contact with the surface of the resistance layer 11 on the opposite side, and a print signal current is caused to flow through the recording electrode 41.

When the recording material is energized, current flows from the recording electrode 41 toward the metal thin film layer 12 at a high density, diffuses within the metal thin film layer 12, and flows toward the return electrode 42 at a low density.

A small area of the recording material generates heat due to Joule heat generated by high-density current or heat generated by interfacial resistance within the recording material, and the ink layer 2 in that area is heated, and the transfer layer 22 is transferred to the recording material along with the transfer layer 22 or the adhesive layer 28. (transfer paper, etc.) 3, each release layer 21 and 25 melts, and the transfer layer 22 is attached to the recording material 3.
By assisting the transfer to or the transfer of the adhesive layer 23 and the transfer layer 22 to the recording medium 3, recording can be obtained in accordance with the print signal current.

The energization conditions, number of scanning lines, etc. greatly affect image formation, but generally the signal voltage is 10 to 200V.

The current application time is 0.05 to 1 m5 ec, and the number of scanning lines is about 3 to 20 lines/■. The recording material 1 and the recording body 2 are brought into complete contact with each other.

The present invention will be further explained below with reference to Examples as well as Comparative Examples, but the present invention is not limited thereto. In the examples, all amounts (parts) of each component are parts by weight.

Example 1 Composition of resistance layer forming liquid m-Funiylene terephthalimide 85 parts Conductive carbon 15 parts Dimethylformamide
A mixture consisting of 900 parts was dispersed in a ball mill for 20 hours, and a gear tube of approximately 200 μm was placed on a glass plate.
The base layer with a thickness of about 6 μm was obtained by casting the coating using a No. m blade, drying for 1 hour in a lIO'c dryer, then immersing it in cold water at about 5° C. for 1 minute and peeling it off from the glass plate. (resistance layer) was obtained. Aluminum was evaporated onto this at 10' Torr to a thickness of about 100 nn+. Furthermore, on top of this aluminum vaporized MK, a first release layer forming liquid having the following composition is applied: ethylene-vinyl acetate copolymer (80% ethylene, M I 300gr/10ml)
15 parts paraffin wax (mp, 78°C) 8
5m was applied to a thickness of 1 μm using a hot melt method. On this first release layer, the following second release layer forming liquid was applied: polyethylene wax (IIlp, 110°C) 20 parts ethylene-vinyl acetate copolymer (ethylene, 90%, MI 100gr/10m1n
) 5 parts 75 parts of toluene were dispersed in a ball mill for 24 hours, applied with a wire bar, and dried with a dryer at 65° C. for 2 minutes to form a second release layer with a thickness of about 1 μm. On this peeling layer, a transfer layer forming liquid having the following composition was applied: polystyrene resin (HH102 manufactured by Mitsubishi Monsando Chemical Co., Ltd.: softening point 101°C, molecular ffi 5
5000) 35 parts Ethylene-vinyl acetate copolymer (72% ethylene, melt index 80) 25 parts Polyethylene oxide (acid value 25, melting point 98°C) 10 parts Paraffin wax (melting point 78°C) 20 parts Carbon black for color burners 10 part toluene
A mixture of 400 parts was milled in a ball mill for 24 hours.
The time-dispersed mixture was applied with a wire bar and dried at 80° C. for 1 minute using a drier to form an ink layer (transfer layer) with a thickness of about 5 μm.

The ink ribbon made in this way has a diameter of approximately 60 μm.
When recording was carried out at an applied voltage of 12 V (resistance 0.5 kQ) and a recording power of 0.25 W using a multi-stylus in which recording electrodes of m recording electrodes were arranged in two rows in a staggered manner at a density of 8 electrodes/mm, the surface was smooth. A high resolution of 16 dots/mm and a dot density of 1.0 on plain paper (recording material) with a Beck smoothness of IO seconds.
4 sharp characters were obtained.

Further, although 5 million characters were repeatedly recorded using this ink ribbon, no ribbon residue was observed on the surface of the multi-stylus. The tensile strength of this ribbon was 790 g.

Example 2 An adhesive layer forming liquid having the following composition was added to the surface of the ink layer (transfer layer) having a thickness of about 5 μm in Example 1, namely: styrene-acrylic copolymer (softening point 90°C) 10 parts carbon for coloring material Black 2 parts toluene
A mixture consisting of 188 parts was dispersed in a ball mill for 24 hours, applied with a wire bar, and dried at 100° C. for 1 minute to form an adhesive layer with a thickness of about 2 μm.

When the ink ribbon thus produced was subjected to recording in the same manner as in Example 1, a high resolution of 16 dots/mn+ was obtained on plain paper (recording medium) with a surface smoothness of 3 seconds in Bekk smoothness. Sharp characters with a dot density of 1.4 were obtained.

As a result of rubbing this image 10 times with a crockmeter (sand eraser), no image was observed to come off.

Furthermore, although 5 million characters were repeatedly recorded using this ink ribbon, no wear of the multi-stylus was observed.

Example 3 1,3-diphenoxy- is added to the second release layer composition of Example 1.
An ink ribbon was formed in the same manner as in Example 1 except that 10 parts of 2-propertool was added. When the ink ribbon produced in this way was recorded in the same manner as in Example 1, a dot density was obtained at a high resolution of 16 dots/mm on plain paper (recording medium) with a surface smoothness of 3 seconds in Beck smoothness. Sharp characters of 1.4- were obtained. As a result of rubbing this image 10 times with a crockmeter (sand eraser), no image was observed to come off. Furthermore, although 5 million characters were repeatedly recorded using this ink ribbon, no wear of the multi-stylus was observed.

Comparative Example 1 Recording was performed using a comparative ink ribbon obtained in exactly the same manner as in Example 1, except that the second release layer was provided directly on the aluminum layer without providing the first release W1 layer. Although a recording somewhat similar to that of Example 1 was obtained, an applied voltage of 18 V (resistance of 0.35 Ω) and recording power of 0.92 W were required to obtain the printing result, which was three times the recording energy of Example 1. It took.

Comparative Example 2 Recording was performed using a comparative ink ribbon obtained in exactly the same manner as in Example 1, except that the first release layer was provided directly on the aluminum layer without providing the second release layer.
Images lacking in sharpness and dot density as low as 1.10 were obtained.

Comparative Example 3 A comparison ink ribbon obtained using the same sphere as Example 1 except that the compositions of the first release layer and the second release layer were mixed to form one release layer was used to record clearly. An image with a low dot density of 1.15 was obtained.

Comparative Example 4 Recording was performed using an ink ribbon obtained in exactly the same manner as in Example 1 except that no aluminum layer was provided, and the applied voltage was 150 V (resistance 4 Ω) and the recording power was 5.
Even at f3W, sharp characters could not be obtained.

Comparative Example 5 Recording was performed using a comparative ink ribbon obtained in exactly the same manner as in Example 1 except that a transfer layer was provided directly on the aluminum layer without providing a release layer. Even with a recording power of 2.5 Ω) and a recording power of 45 W, sharp recording could not be obtained, and at this time, there was a slight odor of burnt recording medium. This was due to the concentration effect of the current due to the aluminum vapor deposited layer, and a large amount of heat was generated in a small area.

Example 4 Recording was performed using the ink ribbon of the present invention obtained in exactly the same manner as in Example 1 except that phthalocyanine was used instead of the carbon black for coloring material in the ink layer (transfer layer) of Example 1. , applied voltage 11.5V (resistance 0.5kQ
), clear cyan characters were obtained with an applied power of 0.26 W, and it was found that the recording material for electrical transfer of the present invention is also suitable for color recording.

[Effects] As described above, the recording material for electrical transfer of the present invention is thinner and more compact than conventional recording materials, and can be used with less energy without being affected by the lubricity of the surface of the recording material. Clear records can be obtained.

Furthermore, printing in colors other than black is easily possible if necessary. Further, according to the recording material of the present invention, sufficient and sharp ink transfer can be performed with a low applied voltage, and the life of the stylus can be extended to achieve highly reliable recording.

[Brief explanation of the drawing]

1, 2, and 3 are cross-sectional views of three examples of the recording material for electrical transfer according to the present invention, and FIG. 4 is an explanatory diagram of the electrical transfer recording method. 1... Base material, 2... Ink layer, 3... Recording body (transfer paper, etc.), 11... Resistance layer,
12... Metal thin film layer, 21... First peeling layer, 22
... Transfer layer, 23... Adhesive layer, 24... Surface layer,
25... Second release layer, 41... Recording electrode, 42...
...Return electrode.

Claims (1)

[Claims] A thin metal film layer is provided on one side of the conductive resin film, and a plurality of heat-melt release layers made of wax and ethylene-vinyl acetate copolymer are provided on the metal thin film layer, and further, through the heat-melt release layers, A recording material for electrical transfer, characterized by being provided with a thermally transferable ink layer.