JPS61144654A - Electrostatic recorder - Google Patents

Abstract

PURPOSE:To improve the corona resistance on the surface of a dielectric layer and the transfer efficiency of a toner and to prevent the adverse influence of frictional electrostatic charge on the dielectric surface by using a recording medium provided with the dielectric layer consisting of inorg. powder having >=10<10>OMEGA.cm volume resistivity, powder having <10<16>OMEGA.cm volume resistivity and a lubricant. CONSTITUTION:The mixture composed of (A) the inorg. powder having >=10<10>OMEGA.cm volume resistivity, (B) the lubricant and or fluoroblock copolymer having <=0.4 coefft. of static friction, (C) the inrog. powder having <10<10>OMEGA.cm volume resistivity and (D) the resin for forming film having >=10<12>OMEGA surface resistance after film formation is used as the recording medium in a dielectric drum 1 which is the recording medium provided with the dielectric layer 2 as a recording layer on a conductive base material 3. The compounding ratio of the lubricant which is the component (B) is a 0.001-300pts.wt., more preferably 0.01-100pts.wt. range by 100pts.wt. the inorg. powder which is the component (A). The compounding ratio of the inorg. powder which is the component (C) is in a 0.1-300pts.wt., more preferably 1-100pts.wt. range by 100pts.wt. the component (A).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrostatic recording device, and particularly to a pressure transfer type electrostatic recording device using an electrostatic recording medium that can be used multiple times.

[Prior art]

Conventionally, as a recording medium in an electrostatic recording device, electrostatic recording paper with a conductive layer provided between the recording layer and a base paper has been generally used. A recorded image is obtained by forming an electrostatic latent image, developing it with toner, and fixing it. However, when such electrostatic recording paper is used, it is unavoidable that excess toner adheres to the surface of the recording paper, and it also has disadvantages such as being highly susceptible to the atmosphere (moisture, heat, etc.) during use. Moreover, since the electrostatic recording paper itself is special compared to plain paper, it has the disadvantage that running costs are significantly higher when used as a consumable item. In order to solve these drawbacks, electrostatic recording devices that transfer images onto plain paper have been developed (for example, Japanese Patent Publication No. 46-34077). According to this method, for example, 10120.
A recording medium provided with a dielectric layer having a volume resistivity above that of the sample is constructed in the form of a belt, and a high voltage is applied between the needle electrode and the dielectric surface using a multi-stylus to generate a discharge. An image is obtained by charging the body surface, then developing the formed electrostatic latent image with toner to obtain a powder image, and electrostatically transferring this to plain paper. However, since this method electrostatically transfers toner images onto plain paper, the transfer efficiency is as low as 80%, resulting in lower image density, disadvantages in terms of cleaning and scattering of residual toner, and the static Image distortion occurs due to electrical transfer.

On the other hand, a dielectric thin layer is provided on the surface of a conductive rigid cylinder, an electrostatic latent image is formed on the surface of this dielectric thin layer, and after this latent image is developed with toner, it is transferred and fixed onto plain paper using pressure. The method is known (for example, Japanese Patent Application Laid-Open No. 54-781)
34, JP-A-55-134872). In this method, the dielectric thin layer is rubbed by the paper, resulting in its surface being polished. Therefore, the point of view is to increase the hardness of the dielectric layer.
Inorganic dielectrics such as 3R glass enamel and organic dielectrics such as polyamide, polyimide, and fluororesin are used. However, anodized aluminum, thermal sprayed At203
．． Inorganic dielectric layers such as glass enamel suffer from a significant decrease in surface resistance due to adhesion of moisture in the atmosphere, making it impossible to obtain good images. Furthermore, organic dielectric layers such as polyamide and terimide have insufficient abrasion resistance, resulting in problems such as surface scratches caused by cutting and scratches caused by cleaners, and sufficient durability cannot be obtained. Particularly when carrying out simultaneous pressure transfer and fixing, friction with the transfer paper is taken into account, making it even more difficult to use an organic recording layer. Furthermore, during long-term use, these organic recording layers are subject to oxidation by ozone under a high electric field, resulting in a decrease in moisture resistance. Polyimide-based and polyamide-based resins are weak against impact and are prone to double-shaped scratches, which cause peeling from those locations.Furthermore, in pressure transfer systems, the surface energy is large, so the transfer efficiency tends to be low at 80 degrees or less. Furthermore, although fluororesin has good transfer efficiency, it is soft and is prone to scratches. Furthermore, in the case of the pressure transfer method, since the surface of the dielectric layer contacts the plain paper and the processing roller under pressure, triboelectric charges are induced on the surface of the dielectric layer. The polarity and amount of the electric charge induced at this time depend on the material of the pressure contact member, such as the components of the transfer material and the resin component of the pressure roller, and the surface roughness of the pressure contact member.
Furthermore, the temperature and humidity of the usage environment vary and are significantly affected. For this reason, if triboelectric charging with a significantly higher potential than the potential of the electrostatic latent image or triboelectrical charging with a polarity opposite to that of the electrostatic latent image occurs, uniform charge removal becomes difficult.

In addition, unnecessary triboelectric charging on the dielectric surface does not promote the adhesion of discharge products and charged fine particles such as paper dust.
Furthermore, when these deposits absorb moisture, the surface resistance significantly decreases, which adversely affects the image. In addition, if the distribution of triboelectric charges on the surface of the dielectric layer is uneven, ion implantation during electrostatic latent image formation may be inhibited, causing negative effects such as blurring and white spots on the image. Therefore, stabilizing triboelectrification by reducing the occurrence of triboelectrification or accelerating the attenuation rate of the triboelectrostatic potential can be achieved by using a dielectric material with a low insulation resistance value. However, a material with a low resistance value could not be used because the surface resistance of the dielectric would also decrease, making it impossible to obtain a stable electrostatic latent image and distorting the image.

As mentioned above, it is not easily affected by moisture in the air, has good transfer efficiency, and has abrasion and impact resistance.

[Problems to be Solved by the Invention] The purpose of the present invention is to solve the problem of electrostatic charge. A recording medium that can be used multiple times and is used in recording devices, especially electrostatic recording devices that use pressure to transfer the toner image on the surface of the dielectric layer of the recording medium onto plain paper, and is susceptible to oxidation caused by ozone, etc. without any
It is an object of the present invention to provide a good electrostatic recording medium that has good toner transfer efficiency, prevents adverse effects on images due to frictional charging, and provides high-quality images over a long period of time.

[Means for solving problems]

According to the present invention, (A) an inorganic powder having a volume resistivity of 1010 Ω or more, (
B) A lubricant and/or fluorine-containing block copolymer with a static friction coefficient of 0.4 or less, (cl) an inorganic powder with a volume resistivity of less than 10 Ω, and (D) a film-forming resin with a surface resistance of 10120 or more after film formation. Provided is a pressure transfer type electrostatic recording device characterized in that a mixture consisting of the following is used as a recording medium by forming a film on a rigid conductive substrate directly or via another dielectric layer.

FIG. 1 shows a dielectric drum 1 serving as a recording medium in which a dielectric layer 2 is provided as a recording layer on a conductive base material 3.

Here, the shape of the recording medium is not limited to the drum shape as shown in FIG. 1, but may be belt-shaped or flat plate-shaped.

The conductive base material 3 is selected from aluminum, aluminum alloy, stainless steel, and other metals, and preferably has a thickness that is not deformed by pressure during pressure transfer or pressure transfer and simultaneous fixing. In addition, in order to soften the surface of the conductive base material or increase the surface area of the conductive base material to improve the adhesion of the dielectric layer coated, for example, anodizing the aluminum alloy surface or hardening the stainless steel surface. Chrome plating may also be performed.

Next, the film-forming resin (component (D)) used as a component of the dielectric layer 2 has a surface resistance of 1012Ω or more after film formation,
Preferably, it is 10130 or more, which is appropriate from the viewpoint of obtaining a stable electrostatic latent image.

Specifically, the film-forming resin used is, for example, I-liimide, bori-amide-imide, f! Lyamide, 4-lyesterimide, polyester, I-rivinyl formal, epoxy resin, 4-lyurethane, melamine resin, acrylic resin, polymethyl methacrylate, polyacrylamide, silicone resin, silicone I-liimide resin, silicone epoxy resin.

Silicone ester resin, imide epoxy resin.

Examples include urethane acrylate resin, epoxy acrylate resin, phenol resin, polyacetal, and fluororesin.

In addition, the inorganic fine powder of component (g) has a volume resistivity of 1010.
It is desirable that the resistivity be 0.Ω or more, preferably 10 11 Ω.sub. or more, so that the volume resistivity of the entire dielectric can be increased and a stable electrostatic latent image can be obtained. Furthermore, the average particle size is 10 μm
It is preferable that the amount is below, whereby the dispersibility of the fine powder in the coating film is good and a uniform coating film can be obtained. Specific examples of such fine powders include alumina, magnesium oxide, -ronnai), F(l', asbestos, silica, glass powder, natural mica 9 synthetic mica, barium titanate, magnesium titanate, zirconium titanate, and zircon). .

Beryllium etc. or mixtures thereof can be used.

In particular, the water of crystallization (OH) in the crystals of natural mica is
) can be used to obtain a dielectric layer with good image characteristics even under high humidity.

The particle size distribution of the inorganic fine powder (component) may be uniform, or may be a combination of particles of different sizes so that the dielectric layer has a structure as dense as possible, and A flaky or fibrous material may also be used.

The mixing ratio of the inorganic fine powder (component A) and the film-forming resin (component D) is 100 parts by weight of the former and 5 to 300 parts by weight of the latter.
Preferably it is in the range of 20 to 200 parts by weight. If the film-forming resin is less than 5 parts by weight, the impact resistance of the dielectric will decrease and the image will deteriorate in a high humidity environment, while if it exceeds 300 parts by weight, the ozone resistance will decrease and the dielectric will be damaged by the cleaner. Sufficient durability cannot be obtained because the surface is easily cut or scratched.

Next, as component (B) of the mixture, a lubricant having a static friction coefficient of 0.4 or less at 25°C and/or a fluorine-containing block copolymer such as an A-B type block polymer containing a fluoroalkyl group are used. used. Static friction coefficient is 0.4
If it exceeds 100%, sufficient lubricity and good developer transfer efficiency cannot be obtained.

7. As the lubricant of component (B), for example, polytetrafluoroethylene, monofluoride, etc. Element-containing compounds and? These include polyethylene and nylon.

By using one or more of the above lubricants as the CB) component of the mixture, the releasability, non-adhesiveness, smoothness and lubricity of the dielectric layer can be improved, and therefore the developer The transfer efficiency is high, the organic components in the developer are less likely to adhere to the dielectric layer, and the abrasion resistance of the dielectric layer is improved.

The fluorine-containing block copolymer used in the present invention has a functional segment that has surface migration properties and a compatible segment that is compatible with the above-mentioned film-forming resin.

Specifically, an A-B type block copolymer is produced by polypolymerizing a fluorine-containing monomer component (e.g., the above-mentioned alkyl group) acting as a functional segment at one end of a polymer acting as a compatible segment. It is. The fluorine-containing monomer component that acts as a functional segment is -
CH2(CF,)2H.

-CH2(CF2)4H#-CH2CF5. -CH2C
H2 (CF2), CF3. Fluoroalkyl groups such as -CF3°02F6 are preferred. Further, as the polymer acting as a compatible segment, one containing a vinyl heptamer component is preferable, and specifically, polymethyl methacrylate, /liptyl methacrylate, polymethyl acrylate, polyethyl acrylate, etc. are suitable.

A-B heavy-containing fluorine containing this fluoroalkyl group as one component,
The compatible segment of the polypropylene copolymer is compatible with the film-forming resin, making it possible to improve the adhesion of the coating film to the substrate and hardness, and also act as a functional segment. The fluoroalkyl groups migrate to the surface, improving the water repellency and mold release properties of the coating surface.

Non-adhesion and lubricity can be improved. These points cannot be obtained when random polymers of the same composition are used.

These fluorine-containing polymeric copolymers can be synthesized using polymeric berrochloride as a polymerization initiator [33rd Society of Polymer Science and Technology Annual Dog Meeting Proceedings, p. 266 (Vo.
I, 33, NO, 2, 1984)].

In addition, as the fluorine-containing block copolymer, Moviper F100. manufactured by NOF Corporation is used. FIIO, F200°F2
10 can be used.

This fluorine-containing block copolymer is a preferred lubricant not only for improving the transfer efficiency and abrasion resistance as described above, but also for obtaining an electrostatic recording material whose electrical properties are always stable without being subjected to ozone oxidation. The reason for this has not yet been fully elucidated, but one reason is that the fluoroalkyl component is not easily susceptible to ozone oxidation. It is presumed that the 70-roalkyl component is easily miscible with the 70-roalkyl component and is regularly distributed on the surface of the recording medium in an extremely microscopic state. The amount of these lubricants is (
A) 0.001 to 3 parts per 100 parts by weight of component inorganic powder
00 parts by weight, preferably in the range of 0.01 to 100 parts by weight. If the amount is less than 0.001 parts by weight, the effect of improving mold releasability and lubricity will not be sufficient, while if it exceeds 300 parts by weight, the impact resistance of the resulting coating film will decrease.

Further, as the component (C) of the mixture, an inorganic powder having a volume resistivity of less than 1.times.10.OMEGA..multidot. Preferably, the volume resistivity is 10 Ω and scratches are removed@Also, the average particle size of the inorganic powder of component (C) is 10Ω.
It is preferably less than μm. If it exceeds 10 μm, the dispersibility of the inorganic powder in the coating film tends to decrease. Such an inorganic powder is, for example, SnO2,5nO2-Ti02t8nO□
- Tin oxide-based inorganic oxides such as Ba804, iron sesquioxide,
triiron tetroxide, nickel sesquioxide, zinc oxide and other metal oxides, or silicon carbide.

Non-oxidizing inorganic compounds such as polycarbon monofluoride and carbon black, or copper, zinc, aluminum,
silicon, iron, cobalt, nickel.

Manganese tungsten 1. Fine metal powders such as tin and antimony, or inorganic fine powders with high resistance (volume resistance 10 Ω・a or more) that have been subjected to conductive treatment, such as silicon dioxide, activated clay, acid clay, kaolin alumina powder, zeolite, etc. Examples include those coated with electroless plating of gold, silver, copper, nickel, etc.

By using an inorganic powder (component C) with a volume resistivity of less than 1010Ω・α as a component for forming the dielectric layer, a stable electrostatic latent image can be obtained without significantly reducing the surface resistance of the dielectric layer. At the same time, a dielectric layer is provided that does not cause image disturbance due to frictional charging with plain paper as transfer paper or a pressure roller. The blending amount of component (C) is component (A) 1
0.1 to 300 parts by weight, preferably 1
-100 parts by weight. If the amount is less than 0.1 parts by weight, the effect of suppressing frictional charging will not be sufficient, and if it exceeds 300 parts by weight, the adhesion of the coating film to the substrate will decrease.

There is a delicate correlation between the mold releasability and smoothness of the dielectric surface, the transfer efficiency of the transfer material, and triboelectric charging.
Good images can be stably obtained over a long period of time only by using a dielectric layer obtained by adding it to the film-forming resin on the 12 Ω opening.

In order to form a dielectric layer as described above on a conductive base material, the mixture is extruded and coated on the conductive base material or on a conductive base material on which another dielectric layer is formed. Alternatively, a diluent may be added to the mixture to make it liquid,
This may be coated.

Next, a preferred mode of creating a recording medium will be described. In the case of a drum-shaped recording medium, a cylinder is made of a conductive base material such as aluminum, aluminum alloy, or stainless steel. The wall thickness of the cylinder at this time needs to be thick enough to withstand pressure during pressure transfer or pressure transfer simultaneous fixing. 10m for aluminum and aluminum alloy
It is desirable that there be at least one. Next, the component (A) used in the present invention is applied to the cylinder surface directly or through another dielectric layer.
), CB), (C) and (D) A coating material containing additional solvents, curing agents, dispersion aids, hardness improving additives, pigments, dyes, etc. is applied and dried to form a film. do.

The film thickness at this time is at least 3μ to maintain electrical insulation.
It is desirable that it is haze or higher, preferably 10 or higher.

Next, the dielectric drum prepared as described above is incorporated into an electrostatic recording apparatus shown in FIG. 2 as a recording medium.

If the configuration of the electrostatic recording device shown in FIG. Publication No. 53-96834, No. 54-5353
Any of the ion implantation types disclosed in Publication No. 7 can be used, and basically it is dot-shaped and has a dielectric material 20.
Any material that can form an electrostatic latent image on its surface may be used. Preferably, the latter type of ion implantation, which does not involve direct discharge between the dielectric 2 and the recording medium 4, is used.

Next, the electrostatic latent image formed by the above-described method is visualized in the developing section 5, and then transferred onto plain paper 9 by pressure by the pressure roller 7. In this case, if a pressure fixable toner is used, the visible image is transferred to the plain paper and fixed at the same time. Next, in accordance with a conventional method, the static electricity on the recording medium after the visible image transfer is removed by the static eliminator unit 8, and the toner on the transfer saw is removed by the cleaner unit 6.

Note that in order to record an electrostatic latent image on the dielectric drum 1 using the electrostatic recording head 4 in accordance with an image signal, Japanese Patent Laid-Open No. 54-78134 is used.
The electrostatic recording head (ion generator) disclosed in the above publication can be used. The electrostatic recording head 4 is the third
As shown in the figure, it consists of a dielectric 35, a drive electrode 36, a control electrode 37, and a screen electrode 39 having an ion emitting aperture 38. An AC voltage is applied between the drive electrode 36 and the control electrode 37 by a power supply 34, and a power supply 31 is applied between the control electrode 37 and the conductive base 3 of the dielectric drum l via a switch 33.
A DC voltage is applied between the screen electrode 39 and the conductive substrate 3 from a power source 32 . The AC voltage applied between the drive electrode 36 and the control electrode 37 generates positive and negative ions alternately. If the image signal turns on the switch 33 (conducts to the contact Y), negative ions are accelerated and the dielectric drum 1
reaches the dielectric layer 2 and is held there.

At this time, the positive ions are not accelerated; therefore, they are discharged between them and the controller electrode 37. If there is no image signal and the switch 33 is off (conducting to contact X), both positive and negative ions will not be accelerated and will be discharged between them and the control electrode 37.

In this way, an electrostatic latent image can be recorded according to the image signal.

Next, an example will be described.

In the examples, the static friction coefficient is the value when the object (lubricant) is stationary on the same material, and in reality, it is the value when the object (lubricant) is stationary on the same material.
This is a value measured using a Type 8 friction coefficient tester.

[Example 1] Cyclized butadiene paint JSRCBR-M (product of Nippon Gosei Fum Co., Ltd., containing 80% by weight of xylene) was applied to the outer peripheral surface of an aluminum alloy cylinder with an inner diameter of 60 mm, an outer diameter of 100 mm, and a length of 230 mm. The cylinder was then heated and dried at 180° C. for 60 minutes to obtain a cylinder coated with grooves having a coating thickness of 3 μm. In this cylinder, (1) Potassium tetrasilicon mica 309, which is a synthetic mica.
(KMg2., (si4o,.)F2] Powder (volume resistivity 5.0×10Ω・F; average particle size 2.5 μm) (2
) Alumina (kt2o,) powder 709 (volume resistivity 4.0×10 Ω・α; average particle size 1.0μ) (3) Tin oxide (5nOz) powder
5g (volume resistivity 1Ω/piece; average particle size 0.1μm)
(4) A-B type 10-block polymer containing a fluoroalkyl group as one component 59 Sodiper F2
00 (Product of Nippon Oil & Fats Co., Ltd.) (5) Ultraviolet curable epoxy acrylate paint (Resin content: 100cm) 70g Unidec V5502 (Product of Dainippon Ink & Chemicals Co., Ltd.) (Surface resistance after biofilm: 8.OX 10Ω) (A) 2-ethelanthraquinone (photoreaction accelerator) 1.49 (7)
Apply the paint obtained by mixing Methyl Ethyl Keto 7 50F, dry it at 80℃ for 10 minutes, and then apply 4K.
The cylinder was irradiated with a W condensing type ultraviolet lamp for 30 seconds at an irradiation distance of 15 as to obtain a cylinder having a coating film of 18 μm in thickness including the cyclized butadiene layer with a coating thickness of 15 μm.

[Example 2] In the same cylinder as that used in Example 1 (cyclized butadiendium layer 3 μm), (1) Fluorine phlogopite (KMg, (At8i30..) F2, which is a synthetic mica):
l 5.1iI (volume resistivity 80X10"Q・c
m: Size of 325 mesh or less) (2) Alumina (AA20.) powder 909
(Volume resistivity 4.OX 10 Ω・tan; Average particle size 1.
0 μm) (3) 4-liquor monofluoride powder 2
0Ii (volume resistivity 2.0 x 10'Ω, average particle size 1
．． 0μ groove.

Coefficient of static friction 0.02) (4) A-B type 10-trick polymer 1.9 Modevar F containing a fluoroalkyl group as one component
100 (Product of NOF Corporation) (5) UV-curable urethane acrylate paint (75% resin content)
50II Enide, Ri 17-824 (product of Dainippon Ink & Chemicals Co., Ltd.) (Surface resistance after film formation: 8.2 x 10 Ω) (A) Apply a paint obtained by mixing 40 g of butyl acetate, After drying at 80°C for 10 minutes, the cylinder was irradiated with a 4kW concentrating ultraviolet lamp at an irradiation distance of 15cl for 30 seconds, resulting in a cylinder having a coating thickness of 15μ including the cyclized butadiene rubber layer formed with a coating thickness of 12μ. I got it.

[Comparative Example 1] A cylinder with a coating thickness of 17 μm (containing a 3 μm layer of cyclized tutadiene) was prepared in the same manner as in Example 1, except that the tin oxide used for surface coating in Example 1 was removed. I got it.

[Comparative Example 2] A-B type 10-block polymer Modiper F2 containing the fluoroalkyl group used for surface coating in Example 1 as one component
A cylinder was prepared in exactly the same manner as in Example 1 except that 00 was removed.
A cylinder of .mu.m) was obtained.

[Comparative Example 3] Unidec V550 used for surface coating in Example 1
Using a mixture of 2 and 2-ethylanthraquinone and methyl ethyl ketone (excluding other ingredients), a coating film thickness of 19 μm (including a layer of cyclized butadiene) was prepared in exactly the same manner as in Example 1.
I got a cylinder.

Comparative tests were conducted on Examples 1 and 2 and Comparative Examples 1, 2, and 3 in the manner described below, and the following results were obtained.

[Test 1] The recording cylinders of Examples 1 and 2 and Comparative Example 1 were installed in the electrostatic recording device described above, and a pressure roller manufactured by Iriasecure was pressed against the cylinders and rotated to reduce friction with the pressure roller. Charge was measured as the surface potential of the recording cylinder. The applied pressure is lo.

kg/, -. The results are shown in Table IK. Values are absolute values. In addition, static electricity was removed from the surface of the pressure roller each time using a static electricity removal slope.

(Table 1), it can be seen that the frictional electrification is reduced by mixing the conductive fine powder.

[Test 2] Example 2 and Comparative Example 2 were tested for durability by image formation. Durability conditions were determined using the electrostatic recording device mentioned above.
An electrostatic latent image was formed on the coating film of the recording cylinder, this was developed using a dry pressure toner, and this toner image was transferred to transfer paper and simultaneously fixed. The durability is 100,000 sheets using A4 paper. The transfer efficiency of the image recording cylinder before and after this durability test was compared. The results are shown in Table 2.

Table 2 Transfer Efficiency Transfer efficiency is calculated by subtracting the weight of the transfer paper before transferring the toner image from the weight of the transfer paper after transfer, making the amount of transferred toner ap, and assuming that the residual toner on the recording medium is by, a/a+b X 10
It was calculated as 0. From Table 2, it was found that the mixing of the surface lubricant had a large effect on the transfer efficiency.

[Test 3] Corona irradiation was performed for Examples 1 and 2 and Comparative Example 3,
Compare the changes in surface conditions.9. The corona irradiation time was 300 minutes, and the surface resistance before and after durability was measured at room temperature (23℃,
60%) and high temperature/high temperature (33°C, 90%). The results are shown in Table 3, which shows that the corona resistance was improved by mixing the inorganic powder.

〔Effect of the invention〕

As explained above, in a transfer type electrostatic recording device, especially a pressure transfer type electrostatic recording device, a dielectric material consisting of an inorganic powder with a volume resistivity of 1010 Ω and scratch removal, a powder with a volume resistivity of 1016 Ω and less than α, and a lubricant is used. By using a recording medium provided with a dielectric layer, the dielectric surface has good corona resistance, toner transfer efficiency is good, and the adverse effects of triboelectric charging on the dielectric surface can be prevented. .

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a dielectric drum as a recording medium), and FIG. 2 is a schematic diagram of main parts of an example of an electrostatic recording device 01 incorporating the dielectric drum shown in FIG. 1. . FIG. 3 shows the recording head. 1: Dielectric drum, 2:! I dielectric layer 3: conductive base material,
4: recording head, 5: developer, 6: cleaner set,
7: Pressure roller, 8: Static eliminator, 9: Plain paper Figure 1 Figure 2 Figure 3

Claims (3)

[Claims] (1) (A) Inorganic powder with volume resistivity of 10^1^0 Ωcm or more, (B) Lubricant and/or fluorine-containing block copolymer with static friction coefficient of 0.4 or less, (C) Volume resistivity of 10^ A mixture consisting of an inorganic powder with a resistance of less than 1^0 Ω・cm and (D) a film-forming resin with a surface resistance of 10^1^2 Ω or more after film formation is applied directly onto a rigid conductive substrate or on another dielectric layer. A pressure transfer type electrostatic recording device characterized in that a film formed through the above method is used as a recording medium. (2) The above mixture contains 100 parts by weight of the above component (A), 0.001 to 300 parts by weight of the component (B), and 0.1 to 0.1 parts by weight of the component (C).
The electrostatic recording device according to claim 1, comprising 100 parts by weight and 5 to 300 parts by weight of component (D). (3) Volume resistivity 10^7Ω・c as the above component (C)
The electrostatic recording device according to claim 1, which contains at least one type of fine powder with a particle diameter of m or less.