US 9,811,018 B2
Negatively-chargeable toner and method for manufacturing same
Hiroyuki Taguchi, Tokyo (JP); and Hisashi Kurokawa, Tokyo (JP)
Assigned to ZEON CORPORATION, Tokyo (JP)
Appl. No. 15/38,212
Filed by ZEON CORPORATION, Tokyo (JP)
PCT Filed Nov. 28, 2014, PCT No. PCT/JP2014/081644
§ 371(c)(1), (2) Date May 20, 2016,
PCT Pub. No. WO2015/080272, PCT Pub. Date Jun. 4, 2015.
Claims priority of application No. 2013-246422 (JP), filed on Nov. 28, 2013; and application No. 2013-267064 (JP), filed on Dec. 25, 2013.
Prior Publication US 2016/0291495 A1, Oct. 6, 2016
Int. Cl. G03G 9/135 (2006.01); G03G 9/097 (2006.01); G03G 9/08 (2006.01); G03G 9/087 (2006.01); G03G 9/09 (2006.01)
CPC G03G 9/09775 (2013.01) [G03G 9/0806 (2013.01); G03G 9/08755 (2013.01); G03G 9/0904 (2013.01)] 10 Claims
 
1. A negatively-chargeable toner comprising colored resin particles which contain at least a binder resin, a colorant, a charge control agent and a softening agent,
wherein the charge control agent is a copolymer which is obtained by copolymerizing a vinyl aromatic hydrocarbon, a (meth)acrylate and a sulfonic acid group-containing (meth)acrylamide and in which a copolymerization ratio of the sulfonic acid group-containing (meth)acrylamide in the copolymer is 0.8 to 4.0% by mass, and a weight average molecular weight of the charge control agent is 5,000 to 25,000, and
wherein the softening agent is at least one of a monoester compound and a polyglycerol ester compound.