GB1396838A - Glutamic ester polymers and electro-photographic materials comprising them - Google Patents

Abstract

1396838 Electro-photographic elements RICOH KK 23 Feb 1973 [23 Feb 1972] 8916/73 Heading G2C [Also in Division C3] Photo-conductive Homo-or-w-polymers contain the unit:- where n is 1 or 2 and R is a heterocyclic group or a polynuclear aromatic group which can contain N 1 O or S atoms. They may be obtained by polymerizing one or more N-carboxy-anhydrides of the appropriate glutamic acid esters e.g. in dioxan as solvent using a primary amine as catalyst. Examples of R are carbozyl, acrydinyl, indolyl, naphthyl, anthryl, phenanthryl and pyrene groups. They have good film-forming ability but poor adhesion and for use in electro-photographic materials are therefore usually compounded with 10 to 50 wt per cent of a resin binder e.g. polymethyl methacrylate, polycarbonates, polyethylene terephthalate, poly-ethylene-butylene or styrene, polyvinyl cinnamate, vinyl chloride/ acetate copolymers or cyclised rubber. Electro-photographic elementscomprise a layer of the polymer/binder blend, desirably containing 20 to 30% of a plasticizer, 0À1 to 5% of a sensitizer and 10 to 150 mol per cent (of the polymer unit) of a pro-sensitizer on a conductive support such as metal, e.g. zinc, cellulose, e.g. paper, or suitably treated plastics, e.g. polyester or PVC, sheets. Suitable plasticizers are dimethyl or dioctyl phthalate or triphenyl phosphate. Numerous dyestuffs suitable as sensitizers are specified. Speci- fied prosensitizers are tetra-cyanoethylene; tetracyanoquinodimethane; phthalic 2, 7-dinitrophetalic and naphthalic acids and anhydrides; naphtho-and anthra-quinone; 2,4,7-tri and 2,4,5, 7-tetra-nitrofluorenone; mononitroazafluorenone; trichlorobenzene and bromal.