Toner and image forming method

摘要

An electrophotographic toner is composed of at least a binder resin, a colorant, and a wax. The binder resin (a) comprises a polyester resin, a vinyl resin and a hybrid resin component comprising a polyester unit and a vinyl polymer unit, (b) has a THF (tetrahydrofuran)-soluble content (W1) of 50 - 85 wt. % and a THF-insoluble content (W2) of 5 - 50 wt. %, an ethyl acetate-soluble content (W3) of 40 - 98 wt. % and an ethyl acetate-insoluble content (W4) of 2 - 60 wt. %, a chloroform-soluble content (W5) of 55 - 90 wt. % and a chloroform-insoluble content (W6) of 10 - 45 wt. %, respectively after 10 hours of Soxhlet extraction with respective solvents, giving a ratio W4/S6 of 1.1 - 4.0, and contains a THF-soluble content providing a GPC (gel permeation chromatography) chromatogram exhibiting a main peak in a molecular weight range of 4000 - 9000, including 35.0 - 65.0 % (A1) of a component haing molecular weights in a range of 500 to below 1x10<4>, 25.0 - 45.0 % (A2) of a component having molecular weights in a range of 1x10<4> to below 1x10<5> and 10.0 - 30.0 % (A3) of a component having molecular weights of at least 1x10<5> giving a ratio A1/A2 of 1.05 - 2.00. The binder resin shows good dispersibility of wax and colorant.