JPH0410598Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to an electrostatic recording medium such as a facsimile machine or a printer. More specifically, the present invention relates to an electrostatic recording material that has high mechanical strength and can withstand repeated use. Conventionally, electrostatic recording materials have been known that are made by laminating an insulating organic polymer film, a conductive layer, and a dielectric layer in this order. has been repeatedly used as In this case, depending on the electrostatic recording method, an image created under the same conditions as for normal electrostatic recording paper will be affected by the transfer corona during transfer, and some parts of the image will have noticeable background stains. Sometimes. For this reason, in the conventional electrostatic recording material laminated in the above order, as shown in FIGS. has been proposed. However, the conventional electrostatic recording bodies shown in Figs. There was a drawback that cracks and peeling were likely to occur at the interface between the layer 3 and the conductive material 4. The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to eliminate the need for dielectric layer 3 and conductive material during film operations such as winding and handling, during installation work as a master film for electrostatic recording, and during repeated use. It is an object of the present invention to provide an electrostatic recording material that does not cause cracks or peeling at the interface with 4, has high mechanical strength, and has good durability. In order to achieve the above objectives, this invention has the following configuration:
That is, each layer of an insulating organic polymer film 1, a conductive layer 2, and a dielectric layer 3 are laminated in the order of 1/2/3, and at least one end of the conductive layer 2 has a layer having a surface electrical resistance lower than that of the conductive layer 2. The electrostatic recording body provided with the conductive material 4 is characterized in that the dielectric layer 3 and the conductive material 4 have a mutually overlapping portion of 0.5 mm or more. Hereinafter, one embodiment of the present invention will be described based on the drawings. FIG. 4 is a diagram showing a cross section of an electrostatic recording medium according to the present invention. In the figure, 1 is an insulating organic polymer film, 2 is a conductive layer, 3 is a dielectric layer, 4 is a conductive material, and 5 is an electrostatic recording material. A conductive material 4 is provided at the end of the conductive layer 2.
A portion of the dielectric layer 3 overlaps a portion of the dielectric layer 3 to form an overlapping portion L where the dielectric layer 3 and the conductive material layer 4 overlap. The dimension of L is 0.5 mm or more, preferably 1 mm or more. Although FIG. 4 shows an example in which the conductive material layer 4 is provided at both ends of the conductive layer 2, the conductive material layer 4 may also be provided only on one side or on the entire circumference (not shown). 5 and 6 show other embodiments of the present invention, in which the conductive material 4 is provided so as to cover the dielectric layer 3, and the conductive material 4 in FIG. 3 is a cross-sectional view showing an example in which a dielectric layer 3 is provided under a dielectric layer 3. FIG. As the insulating organic polymer film 1 in the present invention, a film made of a commonly known thermoplastic resin or thermosetting resin is used. Examples of resins for this film include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalene dicarboxylate; polyolefins such as polyethylene and polypropylene; so-called nylon-6;
Polyamides such as nylon-12, polyimides with a five-membered ring imide bond in the polymer main chain, cellulose derivatives such as cellulose esters, polystyrene, polycarbonates, polyesteramides, polyethers, polyester ethers, polyvinyl chloride, polyacrylic esters , polymethacrylic acid ester, etc. are preferred. Furthermore, copolymers, blends, and crosslinked products of these can also be used. Further, these resins can be formed into a film by stretching, and those subjected to biaxial stretching are particularly preferred because they have improved mechanical properties, thermal properties, optical properties, dimensional stability, etc. Note that the film must be flexible. The composition of the conductive layer 2 includes commonly known metals,
Examples include metal compounds, inorganic conductive powders, and polymer electrolytes. For example, Al, Cr, Fe, Cu, In, Ni,
Metals such as Pd, Pt, Rh, Ag, Sn, alloys or oxides of the above metals, metal compounds such as nitrides, borides, and compounds of metals, inorganic conductive powders such as carbon black and graphite, quaternary ammonium Salts, sulfonates, polyelectrolytes such as polyalcohols, etc. are effectively used. The conductive layer 2 is formed by plating, vacuum deposition, chemical vapor deposition, sputtering, coating, lamination, or the like. The resistance value of the conductive layer 2 varies depending on the electrostatic recording method, but the surface electrical resistance value is 1×10 ⁵
It is preferable that it is about 1×10 ⁸ Ω/mouth. As for the composition of the dielectric layer 3, commonly known thermoplastic resins, thermosetting resins, and organosilicon compounds are used. For example, polyester, polyether,
Polycarbonate, polyamide, polyester amide, polyurethane, polyimide having a five-membered ring imide bond in the main chain, acrylic ester copolymer, methacrylic ester copolymer, polystyrene-butadiene copolymer, polystyrene-acrylonitrile copolymer, Organic silicon compounds such as vinyl acetate, vinyl chloride copolymers, polyvinyl acetals, chlorinated polyolefins, ethylene/vinyl acetate copolymers, alkyd resins, xylene resins, ketone resins, epoxy resins, and oligoorganosiloxanes are preferred. These may be used alone, or may be a copolymer or blend of two or more types, or a crosslinked product. Note that a plasticizer can be used in the dielectric layer 3 in the same way as in general polymer materials for the purpose of improving mechanical strength. As a preferable composition constituting the conductive material layer 4, a metal thin film or metal foil having a thickness of 0.01 to 100 μm, or a conductive paste having a volume resistance value of 1 to 1×10 ⁻⁵ Ω·cm can be effectively used. The conductive material layer 4 can be formed by the same method as the conductive layer 2. Although the resistance value of the conductive material layer 4 varies depending on the electrostatic recording method, it is preferable that the surface electrical resistance value is 5×10 ⁴ Ω/or less. In the present invention, the overlapping portion of the dielectric layer 3 and the conductive material layer 4 is 0.5 mm or more, more preferably 1 mm or more, but if it is smaller than this, cracks or peeling are likely to occur at the interface during repeated use. Note that the present invention does not require the use of a static polymer film to which other polymers are added for the purpose of improving adhesion between the insulating organic polymer film 1 and the conductive layer 2, or between the conductive layer 2 and the dielectric layer 3, if necessary. This includes electromagnetic recording materials. Further, in the present invention, it is also possible to provide a conductive layer on the back surface of the electrostatic recording medium in order to impart antistatic properties. In the present invention, since the dielectric layer 3 and the conductive material layer 4 have a mutually overlapping portion of 0.5 mm or more, the following excellent effects are produced. In other words, during film operations such as winding and handling,
During installation as a master film for electrostatic recording and during repeated use, the dielectric layer 3
No cracking or peeling occurs at the interface between the conductive material layer 4 and the conductive material layer 4, and the mechanical strength is high and the durability is good. Examples will be described below, but the invention is not limited thereto. Example 1, Comparative Example 1 PT was placed on one side of a 350 mm wide 100μ biaxially stretched polyethylene terephthalate film (“Lumirror” manufactured by Toray Industries, Inc.) so that the surface electrical resistance value was 5×10 ⁵ Ω/portion. A sputtered conductive film was obtained. Next, a paint (paint-1) in which polycarbonate resin was dissolved in a mixed solvent of monochlorobenzene/dichloroethane = 1/1 so that the solid content was 10% by weight was coated with a bar coater so that the film thickness after drying was 5μ. It was applied and dried at 150°C for 1 minute. The coating width of the dielectric layer thus obtained was 310 mm, and the conductive layer at both ends where PT was exposed was 20 mm. Next, a conductive paste with a volume resistivity of 10 ^-5 Ω・cm is applied to a thickness of 10 μm (after drying) to a width of 25 mm at both ends, so that the dielectric layer and the conductive material (conductive paste) overlap with a width of 5 mm. An electrostatic recording material A-1 of the present invention was obtained. Next, on the pt of the conductive film obtained above, a conductive paste with a volume resistivity of 10 ^-5 Ω・cm was applied to a width of 20 mm at both ends to a thickness of 10 μ (after drying). Paint-1) as a conductive material (conductive paste)
The electrostatic recording material B-1 was obtained by carefully coating a 310 mm width with a bar coater so as to be in contact with (the thickness of the coating film after drying was 5 μm). In B-1 thus obtained, the overlapping portion of the dielectric layer and the conductive material (conductive paste) was 0.3 mm or less. Image characteristics and mechanical strength of images formed using electrostatic recording materials A-1 and B-1 obtained in this way (a bending test was conducted under the same conditions at the interface between the dielectric layer and the conductive material (conductive paste)) ) were as shown in Table 1. From Table 1, electrostatic recording material A- according to the present invention
It is clear that No. 1 has high mechanical strength and excellent image characteristics. However, B-1 is a comparative example.

[Table] Example 2 After evaporating 0.1μ of Al to a width of 25mm at both ends on the PT of the conductive film obtained in Example 1, polyester resin and silica were added in a solid content of 10% and 1% by weight, respectively.
A coating material was dispersed and mixed with tetrahydrofuran to give a dry thickness of 10 μm, and then applied using a roll coater, dried at 150° C. for 1 minute, and then continuously rolled up. The coating width of the dielectric layer is 310
An electrostatic recording material A-2 of the present invention was obtained in which the overlapping portion of the dielectric layer and the conductive material (Al) was 5 mm. The image characteristics of the image formed using A-2 and the mechanical strength of A-2 were exactly the same as those of A-1.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views showing the structure of a conventional electrostatic recording medium, and FIGS. 4 to 6 are cross-sectional views showing the structure of the electrostatic recording medium of the present invention. DESCRIPTION OF SYMBOLS 1... Insulating organic polymer film, 2... Conductive layer, 3... Dielectric layer, 4... Conductive material, 5... Electrostatic recording material.

Claims (1)

[Scope of utility model registration request] Each layer of an insulating organic polymer film 1, a conductive layer 2, and a dielectric layer 3 are laminated in the order of 1/2/3, and at least one end of the conductive layer 2 is provided with a conductive material having a lower surface electrical resistance value than the conductive layer 2. 4, wherein the dielectric layer 3 and the conductive material 4 have an overlapping portion of 0.5 mm or more.