ELECTROSTATIC IMAGE DEVELOPER

摘要

PURPOSE:To enhance the low-temp. fixability and offset resistance of a developer and to suppress the early damage of the photosensitive body by using a toner contg. a specific copolymer and specific fine inorg. powder after mixing the same. CONSTITUTION:The title developer is used by using the toner contg. the block or graft copolymer of crystalline polyester (A) and ion-crosslinked amorphous vinyl polymer (B) having 3.5 value of the ratio Mn/Ww of a number average mol. wt. Mn and a weight average mol. wt. Mw. The fine inorg. powder (C) having 0.5 to 30m<2>/g BET specific surface area by nitrogen adsorption is incorporated into the title developer. The functional group relating to the copolymn. of the component A and the component B is preferably >=1 of a carboxyl group, hydroxyl group, amino group or epoxy group. The fine powder or the like formed by calcining a mixture composed of strontium carbonate and titanium oxide and pulverizing the mixture is also usable for the component C.