PURPOSE: To obtain the titled resin having an excellent offset resistance without requiring on offset preventing agent, having a good low temp. fixing property without deteriorating the offset resistance and useful for high-speed copying machines or the like, by comprising a specific polyhydric alcohol and a specific tricarboxylic acid as main components.
CONSTITUTION: The objective polyester resin comprises (A) a polyhydric alcohol comprising a diol of formula I (R is -CH2CH2- or group of formula II or III) as a main component and (B) a polybasic carboxylic acid comprising a tricarboxylic acid or an acid anhydride and/or lower alkyl ester thereof (e.g., 1,2,4-benzenetricaboxylic acid) at an amt. of preferably ≥50mol% (based on the total acid components) as a main component. The polyester resin has a softening point of 100W180°C, a glass transition point of 40W80°C and a good preservability and permits the fast fixation of a toner and the saving of energy.
FUNATO MAKOTO
KIMURA SADAO
