PURPOSE: To enable fixing at low temp. under low linear pressure by preheating a specified capsulated toner on a recording medium with an endless heating film and carrying out pressure fixing.
CONSTITUTION: A capsulated toner is composed of a heat meltable core material contg. a colorant and a shell covering the surface of the core material. The shell is based on resin obtd. by allowing 100mol%, in total, of 0-30mol% monoisocyanato compd. (A) and 100-70mol% di- or higher isocyanato compd. (B) to react with 100mol%, in total, of 0-30mol% compd. (C) having one active H atom reactive with an isocyanato group and 100-70mol% compd. (D) having two or more such active H atoms in (1:1)-(1:20)molar ratio of (A+B):(C+D). In the resin, ≥30% of the number of bonds in which all of isocyanato groups take part are thermally dissociable bonds. The toner on a recording medium after transfer is preheated with an endless heating film and pressure fixing is carried out.
KAWABE KUNIYASU
SASAKI MITSUHIRO
