MANUFACTURE OF HIGH-POLYMER PARTICLE AND MANUFACTURE OF ELECTROPHOTOGRAPHIC TONER BY USING THIS METHOD

摘要

PROBLEM TO BE SOLVED: To easily manufacture specific high-polymer particles having the high hydrophobic property of particle surfaces by suspension polymn. by using hydroxylpropyl cellulose specified in viscosity as a suspension stabilizer. SOLUTION: When manufacturing the high-polymer particles by suspension polymn. of a polymerizable monomer in an aq. medium, the hydroxylpropyl cellulose having the viscosity of <=10cps in a 1wt.% aq. soln. is used as the suspension stabilizer. The high-polymer particles or electrophotographic toners having the high degree of the surface hydrophobic property are formed if the hydroxylpropyl cellulose having the viscosity of <=10cps in the 1wt.% aq. soln. at 23 deg.C is used. The reason thereof lies in that the mol.wt. of such hydroxylpropyl cellulose is not particularly a high mol.wt. and, therefore, the easy outflow from the particle surfaces in the process of washing the particles after the suspension polymn. is conceivable. A remarkable effect is not admitted if the hydroxylpropyl cellulose of the viscosity higher than this numerical value is used.