Patent ID: 6846601

Claim:
A negatively chargeable toner comprising i) negatively chargeable toner particles containing at least a binder resin, a colorant and a vinyl copolymer and ii) an inorganic fine powder; said negatively chargeable toner having a weight average particle diameter of from 4 μm to 12 μm, and containing, in particle size distribution of the toner, less than 50% by volume of particles of 10.1 μm or more in particle diameter; and said vinyl copolymer being a vinyl copolymer obtained by copolymerizing a monomer composition which contains at least a vinyl monomer (A) represented by the following formula (1): wherein R 1 represents a hydrogen atom or a methyl group; and R 2 and R 3 each represent a hydrogen atom or an alkyl group which may be substituted with a substituent except for an acid group, or R 2 and R 3 may be combined to form an organic group to form a cyclic structure together with the nitrogen atom; and a vinyl monomer (B) having as a functional group a carboxyl group or a carboxyl group made into salt structure, wherein the vinyl monomer (A) and the vinyl monomer (B) are copolymerized (i) in an amount from 0.5% by weight to 20% by weight of each and (ii) in a proportion by weight from 1:5 to 3:1.