Process for producing liquid developer

Abstract

This invention provides a process for producing a liquid developer for electrophotography or electrostatic recording, produced by a coacervation method, which process can produce a liquid developer which can satisfactorily maintain charging characteristics of the liquid developer and has good dispersion stability of colored resin particles, and a liquid developer produced by the production process. The production process is a process for producing a liquid developer utilizing a coacervation method. In the production process, colored resin particles are dispersed in an insulating hydrocarbon dispersive medium in the presence of a particle dispersing agent, which is a reaction product between a polyamine compound and a self-condensation product of a hydroxycarboxylic acid, and an acid group-containing resin.

Description

technical field The present invention relates to a method for producing a liquid developer for electrophotography or electrostatic recording used in printing machines, copiers, printers, facsimile machines, etc., and a liquid developer obtained by the method. Background technique Among the liquid developers, those in the form of colored resin particles containing a colorant such as a pigment dispersed in an electrically insulating dispersion medium are generally used. In addition, as one of methods for producing such a liquid developer, there is an aggregation method (Coaselbe-Sion method). The coacervation method refers to a method in which the solvent is removed from a mixed solution of a resin-dissolving solvent and an electrically insulating dispersion medium that does not dissolve the resin, whereby the resin contained in the mixed solution in a dissolved state is precipitated in a state of enclosing a colorant, Thereby, the colored resin particles are dispersed in the...

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