SU1010593A1 - Electrographic material - Google Patents

Abstract

ELECTROGRAPHIC MATERIAL, consisting of an electrically conductive substrate and a layer for receiving a charge., Including a pigment and a sound, containing alcohol-soluble resin based on formaldehyde and a sputter, characterized in that the image contrast is increased by increasing the height of the contrast ratio, and the level is reduced by an increase of the contrast ratio. floor, sv. The film as a film screener contains a copolymer of etopacrylate or boothexacrylate with acrylic acid or its amide or chlorinated chlorine when the ratio of resin to foaming agent is from 2: 1 to 1: 8 and the content of components in the layer, wt.%: Pigment-25-89 ( L Binding11-75. With

Description

ate

with

The invention relates to the technology for the manufacture of electrographic materials used in electrographic recording systems. Electrographic material is known that consists of an electrically conductive substrate and a layer for receiving charges containing a pigment, zinc oxide, and a binder, C 13 vinyl butyral. However, this material has a low image contrast due to a low charging potential (220 V at Vaccelo 25 g / m ), which is also due to the use of vinylbutyral as a binder, which is unsuitable for the preparation of layers for receiving charge, since the layers based on it have microdefects, which significantly reduce the charge potential. An electrophotographic material is also known, consisting of an electrically conductive substrate and a layer for receiving a charge, including a pigment — zinc oxide and a binder, containing melamine formaldehyde resin and an alkyd film-forming polymer in the ratio of 1: 9 6: 4 t 23. However, this material does not provide a high contrast image results in a decrease in the charging potential caused by the presence of a layer in the composition for intake. charge of salts of volatile bases introduced to combine alkyd polymer and melamine formaldehyde resin. The closest to the proposed technical essence and the achieved positive effect is an electro graphic material consisting of an electrically conductive substrate and a layer for receiving a charge including a pigment and a binder containing a formaldehyde-based soluble resin and a plesobrazoobrazu. gel. As a pigment, the charge layer contains titanium dioxide, silicon dioxide, zinc oxide, barium sulphate; urea-aldehyde or melamine-formaldehyde resins are used as an alcohol-soluble resin based on formaldehyde; 1 and polyvinyl butyral is used as a film former when the resin corresponds to a film former from 3: 1 to 1: 6 and content. components in a layer, may. %: Pigment33-91 Binder9-67 Due to the decrease in the number of microdefects and the absence of salts of volatile bases in the layer for receiving charges of this material, the potential of charging it is 1.5–2 times higher than that of. the above materials C 33. However, the surface tension of the electrostatic field perceived by the material is substantially less than the maximum intensity of the floor perceived by the pigment, which entails an insufficient contrast of the image. . The purpose of the invention is to increase the image contrast by increasing the surface tension of the electrostatic field. The goal is achieved by the fact that in an electrophotographic material consisting of an electrically conductive substrate and a layer for receiving a charge, including a pigment and a binder, containing a formaldehyde-based spirit-soluble resin and a film-forming agent, the binder contains ethyl acrylate or butyl methyl as a film forming agent. acrylic acid or its amide or chlorinated polyvinyl chloride when the ratio of resin to film former is from 2: 1 to 1: 8 and the content of components in the layer, wt.%: Pigment25-89 Binder 11-75 Qa TBE pigment used titanium dioxide, zinc oxide, silica, barium sulfate or mixtures thereof, as well as alcohol-soluble resins based on formaldehyde - alcohol-urea-formaldehyde, melamine-formaldehyde or phenol-formaldehyde resin. The quantitative composition of the binder is determined by the physicomechanical properties of the fabricated layer for receiving zarzd. With an increase in the amount of formaldehyde-based resin, the glass transition of the layer is observed, which causes it to crack, and an increase in the amount of film former leads to a deterioration in the rheological characteristics of the slurries for applying the layer to receive contamination on the electrically conductive substrate and, accordingly, to the heterogeneity of the layer properties. The binding ratio of the binder is determined by the electrophysical parameters of the electrophotographic material. An increase in the mass fraction of the pigment in the layer, and, accordingly, a decrease in the mass fraction of the binder leads to loosening of the layer to receive a charge — as a result of which the strength, electrostatic field, of the material repressed. The decrease in the mass fraction of rranvieHTa in the layer and. accordingly, an increase in the mass fraction of the binder leads to a decrease in the potential of the layer charge, which causes a decrease in the strength of the electrostatic field. In addition, this reduces the adhesion of the toner layer to receive the charge, and an image smear is observed during the operation of the material. Electrographic material is made in the following way. In a ball mill for 7 hours, the suspension of the components is dispersed to receive a charge in solvents of splsic hydrocarbons, alcohols, keto esters or esters. On the electric. the aqueous substrate is applied in a watering installation; the suspension is applied in a layer with a mass of 5–25 g / m; completely removed, dissolved by drying in a drying cabinet at 105 ° C for 5 minutes; conditioned at a relative humidity of 2 O% for 24 hours, charged by corona discharge at the voltage of the corona. ukv and the surface is measured by a dynamic electrometer. nosg floor perceived by the material, Example. According to the above technology is made by electrography. comic material. The charge intake layer contains, wt%: barium sulphate 29, zinc oxide 60, urea-formaldehyde resin (grade K-411-O2) -1.2, and chlorinated polyvinyl chloride (grade PSC, -LN) 9.8. EXAMPLE 2 A material is prepared in the same way, the receiving layer of which contains, in wt.%: Creme dioxide: 8, titanium dioxide (PO-2 grade) 17, phenol-formaldehyde resin (FL-326 grade) 5O, and copolymer butyl mothacria pata with methacrylic acid (BMK-5 grade) 25, ... EXAMPLE 3. A material is made as described above, the charge receiving layer contains, in wt%: titanium dioxide 6 O, phenol formaldehyde resin (grade FSS-106) 10 and copolymer butnl methacrylate- with amvd methacrylic acid (grade AC) DA. Example 4. Electrographic material is produced analog. The receiving layer for Soderkit, wt.%: Zinc oxide (maroki BCTSH-M) 85, me amnnoforvaldepsh resin (brand K-421-O2) 2.5 and a copolymer of ethyl acrylate with acrylic acid (brand Lacryl) 12.5 .. PRI me R 5. Electrographic material is manufactured according to the technology described above. The charge intake layer contains, in wt%, the titanium bicente 78.4.4, silicate particles 1.6, melamine formaldehyde resin (grade K-421-02) 13.3, and polyvinyl tyral (grade LA) 6.7. In order to clarify the need for introducing into the stock, a layer of the proposed material, a formaldehyde-based, alcohol-soluble resin based material, is made and tested using a non-resin contour electrographic material. ; Example 6. Coitro electrographic material is made similarly to the above. The charge receiving layer contains wt.%: Barium sulphate 85 and a copolymer of ethyl acrylate with acrylic acid (grade) BJ; toluene 15. The ratio of components in the layer and test data are given in the table.

Pigment Binding Pigment Binding

3.8x10

1: 8

4.4 1b

. 2: 1 Binder From the data presented in the table, it can be seen that the proposed electrographic material provides an increase in the surface tension of the electrostatic field perceived by the material by 18–37% compared to the material

The table pr the scrap of the prototype and 20-47% compared with the control material. Due to the increase in the surface tension of the electrostatic field perceived by the material, the image contrast has significantly increased.

Claims (1)

ELECTRICAL GRAPHIC MATERIAL, consisting of an electrically conductive substrate and a layer for receiving a charge, including pigment and. a binder containing an alcohol-soluble resin * based on formaldehyde and a film former, characterized in that, in order to increase the contrast of the image by increasing the surface tension of the electrostatic field, bon—. the binder as a film former contains a copolymer of ethyl acrylate or butyl methacrylate with acrylic acid or its amide or chlorinated sweat "chlorovinyl with a resin to film former ratio from 2: 1 to 1: 8 and the content of components in the layer, wt.%: Pigment 25-89 " Binder 11-75. 1010593 ϊ