Toner and developer for developing electrostatic image, process for production thereof and image forming method

A developer for developing an electrostatic image, comprising:

• toner particles and an external additive;
• wherein each toner particle comprises:
• (i) 100 wt. parts of a binder resin having a glass transition point (Tg) of 50-70° C., wherein the binder resin is selected from the group consisting of
• (a) a binder resin comprising a styrene homopolymer or copolymer and containing a THF-soluble component providing a molecular weight distribution on a GPC chromatogram showing at least one peak (P1) in a molecular weight region of 3×103-5×104 and at least one peak (P2) in a molecular weight region of at least 105;
• (b) a binder resin comprising a polyester resin and containing a THF-soluble component giving a molecular weight distribution on a GPC chromatogram showing a main peak in a molecular weight region of 3×103-1.5×104 and a ratio Mw/Mn between weight average molecular weight and number average molecular weight of at least 10;
• and
• (c) mixtures of (a) and (b);
• (ii) 0.2-20 wt. parts of a solid wax,
• (iii) colorant particles, magnetic powder or a mixture thereof, and
• (iv) lubricating particles carrying a liquid lubricant;
• wherein the liquid lubricant is an oil selected from the group consisting of dimethylsilicone, methylphenylsilicone, methylhydrogen silicone, non-reactive silicones and fluorinated hydrocarbons,
• wherein the lubricating particles are used in a proportion of 1 to 3 wt. parts per 100 wt. parts of the binder resin, and the toner particles retain the liquid lubricant at their surface.