ELECTROSTATIC IMAGE DEVELOPING

摘要

1,272,306. Coated substrates. RANK XEROX Ltd. 22 April, 1969 [26 April, 1968], No. 20518/69. Heading B2E. [Also in Division G2] A developing element for developing electrostatographic latent images comprises a normally solid liquifiable polar developer layer carried on a supporting substrate, said liquifiable layer having a viscosity of less than 104 poises units liquified state and having a volume resistivity in the liquified state of less than 1013 ohm-cm, the free surface of said polar developer layer being in contact with a plurality of developer repellant spacing particles, said spacing particles being of a size sufficient to maintain said polar developer layer substantially out of contact with a surface placed adjacent to and in contact with the side of said spacing particles not in contact with said developer layer. Specified particulate materials are thermosetting resins, thermoplastic resins melting above the liquifying temperature of the developer, glass, sand, calcium carbonate, steel, copper, anthracene, naphthalene, zinc stearate, waxes, titanium dioxide powder coated with zinc stearate, hydrophilic pigments coated with a linear compound having one developer repellent end and one hydrophilic end e.g. stearates, amine salts of long chain fatty acids, long chain aliphatic alcohols and long chain fatty acid amines, the particles being preferably transparent or having a colour which matches that of the ultimate copy sheets. Specified thermoplastic materials which may be used for the developer layer are polyethylene glycols, cetyl alcohol, stearyl alcohol, stearic acid, palmitic acid and admixtures of insulating thermoplastic materials with ionic dyes, quaternary ammonium salts, organic and inorganic humectants or semi-conductive pigments. Additives to modify the colour, melting characteristics or wetting characteristics of the developer layer may be admixed therewith. Specified substrates are paper, polyethylene, terephthalate, aluminium, cellulose acetate and polyolefines, the developer layer being applied thereto by spraying, coating, dipping, extrusion, draw bar coating, calendering, hot melt coating, solution coating or gravure coating.