摘要 |
PURPOSE:To obtain a titled developer of a dry type suitable for use in a heat fixation method, by using a special amorphous polyester resin compsn. as a core material and coating the same with a thermoplastic resin into capsule structure. CONSTITUTION:A compsn. consisting of (a) an amorphous polyester resin having <=60 deg.C glass transition temp., 50-110 deg.C softening temp., 2,000-20,000mol.wt., and 10-150 acid value and (b) 1/500-1/5pts.wt. an aliphat. amine (deriv.) (e.g.; dibutyl amine, polyoxyethylene dodecyl amine) based on the weight of said resin is used as a binder resin. More specifically, (A) the core material consisting of said binder resin and a coloring agent is coated with (B) a vinyl base polymer having >=55 deg.C glass transition temp., 100-150 deg.C softening point, >=150,000Mw and >=5Mw/Mn (Mw is weight average mol.wt., Mn is number average mol.wt.) by using a spray drying method or the like, whereby a developer for electrostatic charge image is formed. |