Polyester salts and their use as charge control agents

Abstract

Polymer salts whose anionic component is a polyester which comprises the product of reaction of the individual components a), b) and c) and if desired d) and if desired e), where a) is a dicarboxylic acid or a reactive derivative of a dicarboxylic acid, being free from sulfo groups, b) is a difunctional aromatic, aliphatic or cycloaliphatic sulfo compound whose functional groups are hydroxyl or carboxyl, or hydroxyl and carboxyl, c) is an aliphatic, cycloaliphatic or aromatic diol, a polyetherdiol or a polycarbonatediol, d) is a polyfunctional compound (functionality>2) whose functional groups are hydroxyl or carboxyl, or hydroxyl and carboxyl, and e) is a monocarboxylic acid and whose cationic component comprises hydrogen atoms, metal cations, substituted ammonium cations, immonium cations, guanidinium cations, phosphonium, arsonium or stibonium cations or a mixture of the abovementioned cations, are suitable as charge control agents and charge improvers in electrophotographic toners and developers, in triboelectrically or electrokinetically sprayable powder coatings, in electret materials and for the electrostatic separation of polymers and salt minerals.

Dependencies are inferred from the claim text.