ELECTROSTATIC IMAGE DEVELOPING TONER, DEVELOPER AND IMAGE FORMING METHOD

PROBLEM TO BE SOLVED: To obtain the electrostatic image developing toner superior in mechanical strength and thermal strength and retained high in image density for a long time and restrained from deterioration of image, such as fog, and superior in developability by incorporating a vinyl polymer having specified cross-linking components as a binder resin. SOLUTION: This toner contains as the binder resin the vinyl polymer having the cross-linking components in at least one of the vinyl monomer units each represented by formulae I and II in which each of R1 -R8 is an H or halogen atom or an 1-10C alkyl group; each of R9 and R10 is an H atom or a 1-6C chain or ring alkyl group; X is a 1-6C chain alkylene or sulfonyl group or the like; (n) us an integer of 1-5; each of R11 and R12 is an H atom or a 1-6C chain car ring alkyl group; each of R13 and R14 is an H atom or a 1-10C alkyl group or the like; and (m) is an integer or 3-20.