Polyester resin, electrophotographic developer composition

Claim 1

An electrophotographic developer composition which comprises a binder resin and a colorant, said binder resin comprising a polyester resin having a softening point of 80° to 180° C., said polyester resin having been obtained by copolycondensing: (A) a diol component of the formula: ##STR5## wherein R represents an ethylene or propylene group and x and y represent each an integer of at least 1, the average number of x+y being 2 to 7, with (B) carboxylic acid components comprising: (a) a dicarboxylic acid, an anhydride thereof or a lower alkyl ester thereof, (b) trimellitic acid, an anhydride thereof or a lower alkyl ester thereof and (c) a polycarboxylic acid having one of the following formulae, an anhydride or a lower alkyl ester thereof, ##STR6## wherein R 1 represents an alkyl or alkenyl group having 20 to 60 carbon atoms, n+m is a number of 10 to 30 and the ratio of n to m is 1:4 to 4:1, the number-average molecular weight being 8,000 to 20,000 ##STR7## wherein X represents an alkylene or alkenylene group having 5 to 30 carbon atoms and at least one side chain having at least 3 carbon atoms.