JPS5859449A - Electrostatic recording material - Google Patents

Abstract

PURPOSE:To obtain high recording potential and a good image of high density, by dispersing specified particles for forming a roughened layer surface into the binder resin of the dielectric layer of a transfer type electrostatic recording material. CONSTITUTION:A latent image formed on the dielectric recording layer of an electrostatic recording material is developed with toner, and transferred to another transfer material. Particles 5 for roughening the dielectric layer surface, such as silica, titanium oxide, or hard ceramics are dispersed into the binder resin 4 of the layer formed on the conductive substrate 3 of the electrostatic recording material made repeatedly usable in any large cycles. At that time, average particle diameter of the particles is controlled within 2-11mum, preferably 4-8mum and the square root of unbiased dispersion of the particles is kept not above 7mum, thus permitting the surface of the recording material to be roughened by dispersion of the particles 5, and the recording electrode to be made ready to discharge because of presence of void 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electrostatic recording material in which a dielectric layer is provided on a conductive substrate.

In recent years, in line with social demands such as an increase in the amount of information, resource saving, labor saving, and pollution-free production, advances have been made in the field of information recording, including the practical application and improvement of various recording methods. The recording method is as follows: ■) The means for forming the image signal is inexpensive and simple.

Ex) Plain paper can be used for recording paper, reducing recording paper costs.

(2) The latent recording part is solid-state electronic scanning and has excellent dismantling power, and the printing speed is extremely fast at about 10 μ(8)/dot.

Next, in order to record a painting using the electrostatic recording method, for example, 1
) irradiate the electrostatic recording medium with an ion stream or scan a stylus (recording needle) on the electrostatic recording medium. After the latent scratches are transferred, etc., they are visualized by dusting them with an electrodetector.

When viewed from a different perspective, these image recording methods (especially 1 above) employ various means such as a scanning type with movable parts, a fixed recording head with multiple needles, an air gap discharge type, and a rear control type. It is connected to the truth.

In addition, conventionally, the latent image formed on the dielectric recording layer by the above-mentioned recording method is used as an electrodetectable toner (electrodetectable toner).
In many cases, the electrostatic toner image was transferred to other transfer materials (e.g., paper, cloth, synthetic paper, etc.) and fixed, and then the toner image was fixed as is. The recording properties that enable the electrostatic recording medium to be used repeatedly, that is, the transfer type electrostatic recording method, are becoming increasingly popular, and the recording medium of the present invention is used for this method. .

An electrostatic latent image is formed by causing a discharge between the stylus and the dielectric layer of the recording medium. For this purpose, a voltage higher than the Paschen discharge firing voltage curve must be applied to the stylus, and the stylus and dielectric layer must be applied to the stylus. If the gap in the dielectric layer is too small, the voltage required to start a discharge will rise rapidly, making it difficult to discharge. On the other hand, if one gap is too large, the voltage required to start the discharge will rise and the discharge will not occur, causing dot diffusion and degrading the resolution.

As described above, the discharge greatly depends on the gap distance between the stylus and the dielectric layer, and it has been extremely difficult to accurately manage the gap distance on the order of μm.

Conventional transfer-type electrostatic recording materials use a dielectric layer with a smooth surface and mechanically manage the gap distance, but the machines that maintain the gap distance are expensive, unreliable, and unsatisfactory. There wasn't. Therefore, by forming unevenness on the surface of the recording medium and bringing the recording electrode into contact with this, the gap between the recording medium and the recording medium is located under the recording electrode where discharge is most likely to occur due to the unevenness of the surface of the recording medium. Securing, discharging, and forming charge latent scratches has been carried out mainly for electrostatic recording paper, but this was done mainly with the aim of improving the writing characteristics of pencils and the like. At this time, the average particle size of the surface unevenness forming particles is 0.
．． It was 1 μm to 2 μm. Furthermore, transfer-type electrostatic recording materials have not yet been sufficiently studied because the irregularities on the surface of the recording material can promote damage such as toner adhesion when the recording material is used repeatedly.

Furthermore, in order to form irregularities on the surface of a recording medium, it is effective to disperse solid powder into a binder resin for a dielectric layer on a conductive substrate. The quantitative influence of particle conditions (average particle size, dispersion, etc.) on recording characteristics was not well known. Therefore, the present inventors focused on the fact that the control of the unevenness on the surface of a recording medium is largely dependent on the particle state of the unevenness-forming particles, and conducted experiments to find a particle state with excellent recording properties, and thus arrived at the present invention. .

That is, in the electrostatic recording material for transfer type of the present invention, surface unevenness forming particles are dispersed in a dielectric layer binding resin on a conductive substrate, and the average particle size of the particles is 2 μm to 11 μm, preferably 4 μm.
m to 8 μm The square root of the unbiased dispersion of the particle diameter is 7 μm or less.

In order to actually produce the electrostatic recording material of the present invention, as shown in FIG. The dielectric layer forming liquid containing the forming particles 5 may be dried on a cloth.

Binder resins include modified urethane resins, modified silicone resins, modified epoxy resins, polyester resins, polycarbonate resins, etc., and surface unevenness forming particles include silicon oxide, titanium oxide, hard ceramic materials (oxides, nitride,
carbide) etc.

Next, in order to actually obtain a recorded image using the electrostatic recording medium of the present invention, it is sufficient to form an electrostatic latent image and then transfer it to the original image in the same manner as in the conventional electrophotographic method. The process is as shown in the figure. An image signal voltage is applied to the endless belt-shaped electrostatic recording medium 7 using the stylus 1, and the electrostatic latent g18
form. This latent g18 is converted into toner by the transfer unit 9 to obtain toner @10, and then transferred to the transfer paper 12 by the transfer corona charger 11 to form the recording surface 91.
Get 3. Even after the transfer process, the toner adhering to the electrostatic recording medium 7 is removed by the fur brush 14, and then the static electricity is removed by the static eliminating corona charger 15, and the electrostatic recording medium 7 is used repeatedly. Represents a roller. The shape of the electrostatic recording medium is not particularly limited, but from the viewpoint of repeated use, an endless belt shape, a rigid drum shape, etc. are common.

Examples are shown below, where all parts are by weight.

Example PT was vacuum-deposited on a 100 μm polyester film to form a conductive film, and the surface resistance of the conductive layer was 8.
X10 mΩ/mouth (Ω/mouth indicates resistance per area). Next, Shin-Etsu Chemical Co., Ltd. X-12-910 liquid was applied onto the conductive film and dried at 80°C for 20 minutes.
A single layer of μm primer was made.

Further, this was dispersed for 3 hours using a Zeel mill, and after the dispersion was completed, the dispersion was applied onto the adhesive layer of the film using a doctor blade coating method, and dried and cured at 95°C for 60 minutes to create a thickness with uneven surfaces. A recording medium with a dielectric layer of 17 μm was prepared.

However, regarding the silicon oxide powder which is the surface unevenness forming particles, recording bodies of the present invention and recording bodies for comparison were obtained with the average particle diameter and σ as shown in the table.

Next, using a single-sided control type multi-stylus (multiple electrode needles) with 8 pieces/■, the stylus applied voltage was -350V and the segment voltage was +3! A peta latent scratch was written using the SOV, and the recorded potential was measured using a vibrating capacitance electrometer manufactured by Kawaguchi Electric, and the results are shown in the table.

From the above results, it was found that the recording medium of the present invention exhibits a high recording potential and can provide good high-density images.

In the comparative recording medium, not only the surface potential was low, but also, especially when the average particle size was small as shown in Comparative Example 1, huge high potential dots were generated in various places due to abnormal discharge. It was thus understood that the average particle diameter of the particles and the dispersion of the particles greatly influence the performance of an electrostatic recording medium having surface unevenness forming particles.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a recording section applied to the electrostatic recording medium of the present invention. FIG. 2 is a schematic diagram of the process applied to the electrostatic recording medium of the present invention. 1... Stylus 2... Polyester film 3... Conductive IL 4... Binder resin 5... Surface unevenness forming particles 6... Discharge gap 7.
・・Electrostatic recording medium 9・・Genrin unit 12・
・・Transfer paper 14・ψ・Fur brush 15・・
・Static charge removal corona charger 1 Figure 2 Figure

Claims (1)

[Claims] 1. In a transfer type Seidenki chronicle in which a dielectric layer in which surface unevenness forming particles are dispersed in a binder resin is provided on a conductive substrate, the average particle size of the surface unevenness forming particles is 2 μm to 11 μm.
1. An electrostatic smoke body characterized in that the square root of the unbiased dispersion of particle diameters is preferably 4 μm to 8 Bm and 7 μm or less.