Electrophoretic liquid developer containing a metal alkyl sulphonate

US4138351A · kind A · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Yvan Gilliams · Boortmeerbeek, BE
• Noel J. De Volder · Edegem, BE
• Robert J. Pollet · Vremde, BE
• Bernard Tavernier · Le Chambon-Feugerolles, FR
• Nikolaas C. de Jaeger · Evergem, BE
• Francis J. Sels · Kontich, BE

Key dates

• Filing date: Sep 14, 1976
• Grant date: Feb 6, 1979
• Expiry date: Sep 14, 1996

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S516/03
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A liquid toner developer composition suitable for use in developing electrostatic charge patterns, characterized in that the developer contains a metal alkyl sulphonate ionic surfactant in which the metal ion is a bivalent metal ion selected from the group consisting of zinc(II), lead(II), cadmium(II) and copper(II) and the sulphonate group thereof is present directly on an alkyl chain containing at least 6 carbon atoms in a straight chain, which sulphonate has a positive charging effect on the toner, and the sizes of the toner particles and the amount in which said sulphonate is present are selected such that the toner can develop a charge pattern having a charge level corresponding to 50 V for a capacitance of 1.5.times.10.sup.-11 F.cm.sup.-2 up to an optical density of at least 0.8.