SU457235A3 - Carrier for electrophotographic display - Google Patents

Description

mixture of these resins. Thermoplastic resins are: polyolefins, for example polyethylene, polypropylene, chlorinated polyethylene, chlorosulfonated polyethylene; and polyvinylidene polyvinyls such as polystyrene, polymethyl styrene, polymethylmethacrylate, polyacrylonitrile, poliviniladetat, polyvinyl alcohol, polyvinyl butyral, polyvinylchloride .nilhlorid, polyvinylcarbazole, polyvinyl ethers and polyvinyl ketones; fluorinated hydrocarbons, such as polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, nolichlorotrifluoroethylene; polyamides, for example polycaprolactam, adipimide polyhexamethylene; polyesters, for example polyethylene terephthalate; polyurethanes; polysulfides; polycarbonates, as well as mixtures of these compounds. The thermosetting resins include: phenol resins, for example, phenol formaldehyde, phenolfurfurol and resorcinol formaldehyde; basic nitrogenous resins, for example carbamide resin, formaldehyde melamine; polyester resins; epoxy resins; mixtures of these resins.

It is recommended to use styrene-n-butyl methacrylate, due to its exceptional triboelectric properties.

The carrier may be coated with the polymer by any method commonly used to coat the carrier, for example, according to the method described in nat. United States 6,618,551.

With the carrier obtained, any colored developing powder can be used. Developing powders include: kopalova resin, sandarak, gum rosin marmoindena resin, asphalt, phenolformaldehyde resins, metaacrylic polystyrene resins, polypropylene and polyethylene resins, epoxy resins and mixtures of these resins.

Nro is can be applied powders described in US Pat. U.S. 2,659,670; 2753308; 3079342; 2788288. These powders usually have an average particle diameter of about 1-30 microns. A developing powder containing a styrene-n-butyl methacrylate copolymer, polyvinyl butyral and carbon black obtained by the method described in Example 1 of US Pat. U.S. Patent 3,079,342, is preferred because of its exceptional tri-electrical properties and due to its deep black color.

The limiting diameter of the coated carrier particles, 50-1000 µm, is preferred because the carrier particles have sufficient specific gravity and inertia to avoid electrostatic imaging during the cascade development process. The adherence of carrier particles on the surface of the xerographic drum is undesirable due to the formation of deep scratches on the surface during image transfer and during the drum cleaning process, especially when cleaning is performed with a cloth cleaner, for example with a cloth, according to US Pat. U.S. 3,186,838. Satisfactory results are obtained when around

1 weight. h of nano powder is used

approximately 10-200 weight. h. carrier

The resulting carrier particles are used.

in a developer used to produce a latent electrostatic image obtained on known photoconductive materials, such as vitreous selenium, organic or inorganic photoconductive materials.

Example 1. The manufacturer is prepared by mixing 1 wt. including a developing powder consisting of styrene-n-butyl methacrylate copolymer, polyvinyl butyral and carbon black, obtained by

the method described in example 1 q. USA 3079342, with an average particle diameter of 10-20 microns and 200 weight. h. carrier The carrier, in turn, consists of 200 weight. including particles and resin covering it, as described in example 1, US Pat. USA 2618551. Particles of the carrier contain, weight. including: iron 96.9, carbon 1, manganese 1, silicon 1, aluminum 0.04, phosphorus 0.25 and sulfur 0.035. The developer is distributed in a cascade manner over a surface that carries a positively charged electrostatic image. The produced image is electrostatically transferred onto a sheet of paper, where it is fused by heating. The resulting image is dense and mostly free from deposits of the developing powder in the background areas of the image. The media is examined after the development of several hundred images. No flakes, separated particles, or damaged areas were found in the material covering the carrier.

Example 2. Example 1 was repeated using a mixture for coating a carrier.

in example 2 US Pat. USA 2618551 and the use of particles of the composition, wt. including: iron 95, carbon 0.1, manganese 0.5, silicon 0.5, aluminum 0.03, phosphorus 0.01, sulfur 0.02. Mostly the same results were obtained as

in example 1.

Example 3. Example 1 was repeated using the mixture for coating the carrier according to Example 4, Pat. USA 2618551, and with the use of particles of the composition, weight. including: jel30 99, carbon 2, manganese 2, silicon 2, aluminum 0.1, phosphorus 0.05 and sulfur 0.05. The results are similar to the results of example 1.

Example 4. Example 1 was repeated using a mixture for coating a carrier.

according to example 3 nat. USA 2618551, and with the use of particles of the composition, weight. including: iron 97, carbon 0.95, manganese 1.05, silicon 1.05, aluminum 0.04, phosphorus 0.03 and sulfur 0.04. The results are similar to the results of example 1.

Subject invention

1. Carrier for electrophotographic

a particle and dielectric coating, characterized in that 5 in order to obtain a mold that is insensitive to moisture, increase abrasion resistance of the carrier, improve its triboelectric properties and increase the specific weight, the composition particles are used, 5 weight. including: iron 95-99, carbon 0.1-2, margab 0.5-2-2, silicon 0.5-2, aluminum 0.03-0.1, phosphorus 0.01-0.05 and sulfur 0 , 02-0.05. 2. The carrier according to claim 1, differing from the fact that particles of composition are used, wt. including: iron 96.9, silicon 1, aluminum 0.04, phosphorus 0.025, sulfur 0.035, carbon 1 and manganese 1.