GB1416047A - Electrostatographic developer compositions - Google Patents

Abstract

1416047 Liquid toners comprising polymer blend dispersions RICOH KK 26 Jan 1973 [4 Feb 1972] 4020/73 Heading C3P [Also in Division G2] A liquid developer for use in electrostatography comprises a blend of a pigment, and a polymer containing units derived from at least one compound of the formula wherein X is H or -CH 3 and Y is H, C 6 H 5 -, -C 6 H 4 .CH 3 (4 - substituted), -COOH, -COOC n H 2n+1 , where n is an integer of 9-20, or -CH=CH 2 , in a solvent comprising an aromatic hydrocarbon and a petroleum aliphatic hydrocarbon, the solvent having a solubility parameter of 7À0-7À5, the blend being dispersed with a copolymer containing units derived from a monomer of formula wherein X is H or -CH 3 and n<SP>1</SP> is an integer of 6-20, and a monomer of formula wherein X is H or CH 3 and Z is -C 6 H 5 -C 6 H 4 .CH 3 (4-substituted), or -COOC n <SP>11</SP> 2n <SP>11</SP> +1 wherein n<SP>11</SP> is an integer of 1-5 (the monomers (II) and (III) each having a solubility parameter of 7À5 to 8À7 and the copolymer having a molecular weight of 5000 to 30,000), in a petroleum aliphatic hydrocarbon having a solubility parameter of 7À0 to 7À5. Examples of the first polymer are copolymers of styrene/butadiene, lauryl methaorylate/acrylic acid, vinyl toluene/ butadiene, stearyl methacrylate/ethylene, butadiene/alkyl acrylate, and examples of the second polymer are copolymers of 2-ethylhexyl methacrylate/methyl acrylate, 2-ethylhexyl methacrylate/isobutyl methacrylate, lauryl methacrylate/ethyl acrylate, stearyl methacrylate/ methyl methacrylate, lauryl methacrylate/ styrene and 2-ethylhexyl methacrylate/vinyl toluene/isobutyl methacrylate. The aromatic hydrocarbon is preferably toluene or xylene. Aliphatic hydrocarbons used are commercially available mixtures. In the examples, the pigment is carbon black, and the components are blended in a ball mill to obtain the requisite fine particle size.