Patent ID: 8883946

Claim:
A charge control agent, comprising: a charge control resin including a polymer as its active ingredient having a constituent unit of formula (1): wherein, in formula (1): R 1 is independent of one another, and is a hydrogen atom, a hydroxyl group, a halogen atom, a carboxy-containing group, a straight-chained alkyl group having 1-18 carbon atoms, a branched alkyl group having 1-18 carbon atoms, a straight-chained alkoxy group having 1-18 carbon atoms, or a branched alkoxy group having 1-18 carbon atoms; R 2 is a hydrogen atom, a hydroxyl group, a halogen atom, a carboxy-containing group, a straight-chained alkyl group having 1-18 carbon atoms, a branched alkyl group having 1-18 carbon atoms, a straight-chained alkoxy group having 1-18 carbon atoms, or a branched alkoxy group having 1-18 carbon atoms; g is a number of 1-3; h is a number of 1-3; and M is a hydrogen atom, an alkali metal, a straight-chained alkyl group having 1-18 carbon atoms, a branched alkyl group having 1-18 carbon atoms, an ammonium radical, or a mixture thereof, wherein the polymer has a glass transition temperature of 70° C. through 150° C.