Toner for developing electrostatic image, image forming method and process-cartridge

A toner for developing an electrostatic image, comprising a composition containing

• (i) 100 wt. parts of a binder resin component,
• (ii) 20-200 wt. parts of a magnetic colorant or 0.1-20 wt. parts of a non-magnetic colorant, and
• (iii) 1-20 wt. parts of a low molecular weight wax, wherein
• (a) the binder resin component has a tetrahydrofuran (THF)-insoluble content of at most 5 wt. %,
• (b) the binder resin component contains a THF-soluble low-molecular weight component having a molecular weight of at most 5.times.10.sup.4 and a branching index g' of at most 0.97,
• (c) the THF-soluble low-molecular weight component comprises a branched styrene copolymer,
• (d) the binder resin component has a ratio (Mw/Mn) between weight-average molecular weight (Mw) and number-average molecular weight (Mn) of greater than 30,
• the binder resin component has a glass transition temperature of 50-70.degree. C. and
• (f) the binder resin component contains the low-molecular weight Polymer component providing a main peak in a molecular weight region of 2.times.10.sup.3 -3.times.10.sup.4 and a high-molecular weight component providing a sub-peak or shoulder in a molecular weight region exceeding 5.times.10.sup.4, respectively, on a molecular weight distribution based on gel permeation chromatography (GPC) of tetrahydrofuran (THF)-soluble component of the binder resin component.