Electrostatic image-recording medium and method of making same

Claim 2

AN ELECTROSTATIC IMAGE-RECORDING MEDIUM COMPRISING A DIELECTRIC LAYER PROVIDED ON A CONDUCTIVE BASE SUPPORT, SAID DIELECTRIC LAYER BEING COMPOSED OF A LINEAR POLYMER HAVING A SPECIFIC VOLUME RESISTIVITY OF OVER 1012$-CM THAT IS SOLUBLE IN A SOLVENT SELECTED FROM THE GROUP CONSISTING OF AROMATIC HYDROCARBONS, KETONES AND ESTERS AND POLYCARBONATE RESIN WHICH IS SOLUBLE IN A HALOGENATED HYDROCARBON DISPERSED IN SAID LINEAR POLYMER.

Claim 3

The electrostatic image-recording medium of claim 1 in which said linear polymer is selected from the group consisting of vinyl linear polymers and saturated linear polyesters.

Claim 4

The electrostatic image-recording medium of claim 1 in which said linear polymer is selected from the group consisting of polymethylacrylate, polymethylmethacrylate, polyethyl methacrylate, polystyrene, polyvinylchloride, and polyvinylacetate homopolymers and methyl methacrylate/methyl acrylate, methyl methacrylate/butyl methacrylate, methyl methacrylate/ethyl acrylate/monomethyl itaconate, methyl acrylate/styrene, methyl acrylate/dimethyl itaconate, vinylchloride/vinylacetate, vinylidene chloride/acrylonitrile, vinylidene chloride/vinyl chloride and vinyl acetate/crotonic acid, styrene/acrylonitrile, styrene/acrylic acid, styrene/methyl methacrylate, styrene/lauryl methacrylate, styrene/butyl acrylate, styrene/vinyl acetate, methyl acrylate/diethyl itaconate, methyl methacrylate/ Alpha -methylstyrene, methyl methacrylate/lauryl methacrylate/acrylic acid, butyl methacrylate/methyl methacrylate/monomethyl itaconate, vinyl chloride/diethyl maleate, vinyl chloride/vinyl stearate, vinyl chloride/methyl acrylate, vinyl chloride/2-ethyl hexyl acrylate, vinylidene chloride/methyl acrylate, vinyl acetate/maleic acid, vinyl acetate/acrylonitrile copolymers.

Claim 5

The electrostatic image-recording medium of claim 1 in which said linear polymer is a saturated polyester selected from the group consisting of ethylene terephthalate/ethyleneisophthalate, ethyleneterephthalate12.2-bis(4-( Beta -hydroxyethoxy) phenyl)propaneterephthalate, bis( Beta -hydroxyethyl)terephthalate12.2-bis(4-( Beta -hydroxyethoxy)phenyl) propaneterephthalate, diphenolterephthalate/diphenol isophthalate, 2.2-bis (4-( Beta -hydroxyethoxy) phenyl) propaneterephthalate.isophthalate/neopentylglycolterephthalate.is ophthalate, and 2-methyl-2-propyl-1.3 -propanediolterephthalate.isophthalate/ethyleneterephthalate.isoph thalate/ethylene-terephthalate.isophthalate copolyesters.

Claim 6

The electrostatic image-recording medium of claim 1 in which said polycarbonate resin is selected from the group consisting of a polycarbonate derived from 4,4''-dihydroxydiphenylpropane (bisphenol A), a polycarbonate derived from tetrachlorobisphenol A, a polycarbonate derived from 4,4''-dihydroxydiphenyl norbornyl-methane, a polycarbonate derived from 4,4''-dihydroxy 3,3'',5,5''-tetra-chlorodiphenyl-norbornylmethane, a copolycarbonate derived from bisphenol A and tetrachlorobisphenol A, a copolycarbonate derived from bisphenol A and 4,4''-dihydroxyphenylether and a copolycarbonate derived from bisphenol A and 4,4''-dihydroxy diphenyl sulfone.

Claim 7

The electrostatic image-reCording medium of claim 1, in which said linear polymer is selected from the group consisting of styrene, acrylic, vinylchloride, vinylidenechloride and vinyl acetate polymers.

Claim 8

The electrostatic image-recording medium of claim 1, in which said polycarbonate is a derivative prepared from a 4'',4-dioxydiarylalkane.

Claim 9

A process for producing an electrostatic image-recording medium, which comprises the steps of selecting component A) a linear polymer which is soluble in a solvent selected from the group consisting of aromatic hydrocarbons, ketones and esters and exhibits a volume specific resistance of over 1012 Omega -cm as the main component of a dielectric layer for said medium; selecting Component B) a polycarbonate resin that is soluble in a halogenated hydrocarbon solvent and insoluble in an aromatic hydrocarbon, ketone and ester solvents as the secondary component; dissolving component A in a solvent selected from the group consisting of aromatic hydrocarbons, ketones and esters, dissolving said component B in a halogenated hydrocarbon solvent, mixing the two resulting solutions to thereby disperse said component B as a fine grained gel with high dispersion stability, and coating a conductive base support with this dispersion composition.

Claim 10

A process for producing an electrostatic image-recording medium, which comprises the steps of selecting component A) a linear polymer which is soluble in a solvent selected from the group consisting of aromatic hydrocarbons, ketones and esters and exhibits a volume specific resistance of over 1012 Omega -cm as the main component of a dielectric layer for said medium; selecting Component B) a polycarbonate resin that is soluble in a halogenated hydrocarbon solvent and insoluble in an aromatic hydrocarbon, ketone and ester solvents as the secondary component; dissolving component A in a solvent selected from the group consisting of aromatic hydrocarbons, ketones and esters, dissolving said component B in a halogenated hydrocarbon solvent, mixing the two resulting solutions to thereby disperse said component B as a fine grained gel with high dispersion stability, and coating a conductive base support with this dispersion composition.

Claim 11

The process for producing an electrostatic image-recording medium of claim 7, which comprises the step of dissolving the linear polymer in a solvent selected from the group consisting of benzene, toluene, xylene, acetone, methylethylketone, methylisobutylketone, and butyl acetate.

Claim 12

The process for producing an electrostatic image-recording medium of claim 7, which comprises the step of dissolving the polycarbonate resin in a solvent selected from the group consisting of methylene chloride, ethylene chloride, monochlorobenzene, chloroform, methylchloroform, trichloroethylene and tetrachloroethane.