Patent ID: 8722297
Filing Date: 2014-05-13
Classification: C08G,G03G

Abstract:
1. A process for producing a resin binder for toners which contains a crystalline polyester, comprising the step of polycondensing at least an alcohol component containing an aliphatic diol having 2 to 12 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 8 to 12 carbon atoms in an amount of from 70 to 100 mol %, wherein a molar ratio of the carboxylic acid component to the alcohol component (carboxylic acid component/alcohol component) is from 1.03 to 1.20, and the process includes the step of conducting the polycondensation in a temperature range of from 130 to 160° C. until a reaction rate as calculated from an amount of a reaction water discharged from the reaction system reaches 40% or more assuming that the reaction rate upon discharge of a theoretical amount of the reaction water is 100%; wherein a content of a methyl ethyl ketone soluble component (at 20° C.) in the crystalline polyester is from 0.5 to 7% by weight on the basis of a weight of the crystalline polyester, and a difference between a melting point of the crystalline polyester and a peak top temperature observed in DSC measurement of the methyl ethyl ketone soluble component (“melting point of the crystalline polyester”−“peak top temperature observed in DSC measurement of the methyl ethyl ketone soluble component”) is within the range of from 1 to 15° C.