Liquid electrographic developer

Claim 1

An electrographic developer composition comprising an electrically insulating carrier liquid having dispersed therein (1) an addition polymer comprising a polar moiety and at least one additional moiety having predetermined solubility characteristics with respect to the carrier liquid, said polar moiety being selected from the group consisting of (a) sulfoalkyl acrylates, (b) sulfoalkyl methacrylates, (c) metal salts of sulfoalkyl acrylates, (d) metal salts of sulfoalkyl methacrylates, (e) amine salts of sulfoalkyl acrylates, (f) amine salts of sulfoalkyl methacrylates, (g) metal salts of acrylic cid and methacrylic acids and (h) amine salts of acrylic and methacrylic acids, and mixtures thereof; (2) a soluble phosphonic moiety-containing polymer having repeating units derived from a monomer of the formula: ##STR16## wherein: R is hydrogen, an alkyl group or an aryl group; R 1 is hydrogen or a lower group having from 1 to about 4 carbon atoms; R 2 is hydrogen or an alkyl group; and Z is alkylene, arylene or alkylene-arylene; the solubility ratio of said soluble phosphonic moiety-containing polymer being at least about 0.825; and (3) a halogenated polymer.