| 摘要 |
PURPOSE:To improve quality of a picture image by fixing and burying a fluidity improver having a positive electric charge to near the surface of fine particles contg. negatively charged colorant and using further magnetic particles comprising ferrite particles. CONSTITUTION:When positively charged particles of a fluidity improver are fixed to the surface of fine particles contg. negatively charged colorant, the negative charge of the fixed part is neutralized. On one hand, the negative charge at the unfixed parts is held without being neutralized, so that amt. of the charge of the whole toner particles is controlled to an appropriate negative value. Thus, strongly chargeable parts and weakly chargeable parts are formed on the surface of toner particles, and the charge of the whole of the toner becomes very stable. Magnetic particles to be used are ferrite particles prepd. by covering with a mixture consisting of a resin which is charged negatively by the friction with iron powder carrier and a positively chargeable resin. Thus, negative chargeability of a toner is reduced relatively and excessive charge of the toner is prevented. By this method, picture images having high quality are obtd. |
