SU439099A3 - METHOD OF OBTAINING PHOTO CONDUCTING MATERIAL - Google Patents

Description

one

This invention relates to a method for producing photoconductive electrophotographic material.

A known method for producing a photoconductive material is deposited on a substrate with a mixture containing mainly crushed selenium alloy with a small amount of an electrically insulating resin, followed by drying.

However, with a high content of resin in the material, its photosensitivity decreases, and with an increase in the amount of selenium, the layers become brittle and unsuitable for use with flexible or moving substrates in high-speed machines.

The purpose of the invention is to increase the flexibility of the material and to preserve its high photosensitivity, which is achieved by the fact that the photoconductive material is annealed at the glass transition temperature of selenium silive or higher, preferably at 40-185 ° C.

As a selenium alloy, you can use an alloy of selenium with a mouse, sulfur, bismuth, antimony, tellurium or CMecbio with one of them or several at once.

Usually, selenium alloy containing 0.5–50% mouse is used.

The particle size of the selenium alloy is most often 1-10 microns.

For example, a typical snlav contains 88.3%

particles with a size of 10 microns, 8.5% with a size of 10-20 microns, 2.9% with a size of 20-30 microns n 0.3% with a size of 40-50 microns. As an electrically insulating resin

Chlorinated rubber is preferably used, for example, Perlon P natural chlorinated natural rubber, Perlon P isotactic polypropylene, Hypalon polyethylene, as well as polystyrene, polyethers, phenol efpry, silicone resins, polyacrylates, ethyl cellulose, polypropylene, polyether, polymers, polyacrylates and polymethacrylates; blends, chlorinated polyolefins, natural rubbers or niolefins with the addition of significant amounts of chlorine (up to 65% or more) to modify the elastomer.

Most often, to obtain a photoconductive material, a mixture containing about

60-97 weight. %, preferably 90-95 weight. %, selenium alloy, and 3-40 weight. %, preferably 5-10 weight. % resin.

After drying before annealing, the photo conductor of the particle is mostly uniformly spun in electrically insulated cyopion resin, fully or partially (up to 40% of voids) surrounding the individual photoconductive particles. During annealing at the fermentation temperature of the green alloy or higher, it occurs

melt foam, sticking together and formation

a continuous lattice of vitreous selenium alloy containing discrete particles or portions of the resin, arbitrarily dispersed but photonically conductive matrix.

In addition, during melting, the photoconductive particles fill the voids. The resin accumulates in areas of up to 5 microns, surrounded by the continuous vitreous structure of the selenium alloy, and is observed as separate islands or isolated particles or nets, partially or halfway around the surrounding areas of the photoconductive matrix.

Usually, annealing is carried out in the range from 30 minutes to several hours.

FIG. Figure 1 shows the range of glass transition temperatures for selenium alloys with a mouse. When the content of the mouse ka-40 weight. % it is 40-185 ° C.

Example 1. A vitreous alloy containing (in wt.%): 17 mice, 82.9 selenium and 0.1 iodine, crushed in a micromelnate for 15 minutes, sieved through a sieve 325 mesh and get powder, 89% of the particles of which have size less than 10 microns 95 g of the sifted powder is mixed with 50 g of a 10% aqueous solution of chlorinated rubber in toluene, applied to a brass foil 0.1 mm thick, to obtain, after final drying, a coating 20 microns thick. The coated foil in the form of a plate is created for 30 minutes at 50 ° C, burned for 1 hour at 165 ° C, mounted on an aluminum drum of a Xerox 813 Office Copier xeroconvering mask and obtained a photocopy in the usual way. Under similar conditions, the photosensitivity of the photocopy is 2.5 times greater than that of the photocopy obtained using vitreous selenium, the residual surface is zero, the elasticity of the plate is high.

FIG. 2 shows the microsection of the obtained plate with a 5000-fold increase under the electron microscopic before annealing. The structure consists of 95 wt. including photoconductive vitreous particles of the alloy (27% of arsenic and 73% of selenium) are dark spots mixed with 5 wt. h. chlorinated rubber "Perlon - lighter or gray n tna.

FIG. Figure 3 shows the same structure after annealing at 150 ° C for 1 hour, resulting in fusion or sticking of photoconductive particles to a photoconductive matrix (dark areas), which is surrounded by lighter or gray areas or resin particles. The resin is in addition to discrete particles or regions in the form of grids.

Example 2. Snlav-containing (in wt.%): 28 mice, 71.9 selenium and 0.1 iodine, crushed in a planetary mill for 30 minutes, sieved through a 325 mesh sieve and 48 g of sifted powder mixed in 1 hour in a planetary mill with 2.5 g of chlorinated rubber. To the dry mixture is added 25 g of toluene, stirred for 1 hour in a planetary mill, applied on brass foil with a thickness of

0.1 mm, in order to obtain a final coating with a thickness of 48 microns, is 15 minutes at 50 ° C, annealed for 1 hour at 175 ° C and installed on an aluminum drum of the Xerox 2400 Office Copier Xeroxing Machine. The photosensitivity is 4-5 times higher than when using glassy selenium, and the residual potential is zero. Example 3. Analogously to example 2, a plate is obtained with a dry coating thickness of 90 microns, whose electrical characteristics and elasticity are about the same as those of the plate obtained in example 2. In addition, when using a plate for reproducing originals, prints of good quality with a small background are obtained .

Example 4. A plate prepared as in example 2, but annealed for 1 hour at 175 ° C, with a higher residual potential, has a greater elasticity.

Example 5. The electrical and physical characteristics of the plate, obtained similarly to example 2 with the use instead of chlorinated rubber phenolic resin brand RKNN, similar to the plate, made in example 2.

Example 6. As in Example 2, a plate was fabricated, the photoconductive layer of which contains 28% mouse and 72% selenium at a thickness of 60 microns. The plate has high electrical and physical characteristics.

Thus, it can be seen that before annealing, the photonics are basically evenly dispersed in the resin, while each photoconductive particle is covered with a layer of resin and the film has up to 40% of voids before annealing. During annealing, which is conducted near and above the temperature of the amorphous photoconductive transition

selenium alloy, the particles flow and stick together with each other, forming a glassy alloy matrix with distributed dispersed resin particles.

Subject invention

Claims (8)

1. A method of producing a photoconductive material by depositing a mixture on the substrate, including mainly crushed selenium alloy and a small amount of electrical insulating resin, characterized in that, in order to increase the flexibility of the material while maintaining high photosensitivity, the material is annealed at the glass transition temperature of the selenium alloy or higher . 2. A method according to claim 1, characterized in that, as an electrically insulating resin Chlorinated rubber is used. 3. Method for ip. 1 and 2, characterized in that a selenium alloy with a particle size of 1-10 microns is used. 4. Method according to paragraphs. 1 and 3, characterized in that a selenium alloy with one or several substances is used as a selenium alloy; mouse com, gray, bismuth, antimony or tellurium. 5. A method according to claim 4, characterized in that a selenium alloy containing 0.5-50 wt.% Is used. % mouse 6. Method according to paragraphs. 1-5, characterized in that a mixture comprising 60- 97 wt. % selenium alloy and 3-40 weight. % resin. 7. Method according to paragraphs. 1-6, characterized in that a mixture is used containing 90-95% by weight of selenium alloy and 5-10% by weight. % resin. 8. Method according to paragraphs. 1-7, characterized in that the annealing is carried out at 40-185 ° C. 0 5060 thirty As content weight 7o