Mitsui Chemicals, Inc.

Junko Tobita

Nobuhiro Hirayama

Eishi Tanaka

Katsuru Matsumoto

A resin composition is provided for an electro-photographic toner. The composition comprises 5 to 95 parts by weight of a high molecular weight vinyl copolymer polymer and 95 to 5 parts by weight of a low molecular weight vinyl copolymer. The former ethylene polymer has a weight average molecular weight (Mw) of from 200,000 to 1,000,000 and a ratio (Mw/Mn) of the weight average molecular weight (Mw) to a number average molecular weight (Mn) of from 8 to 300, and the latter vinyl copolymer has a weight average molecular weight of from 3,000 to 20,000. At least one of the former and latter vinyl copolymer, preferably, the former vinyl copolymer is an ethylene polymer which has been obtained by conducting polymerization in the presence of a monomer having an ionization potential of from 10.0 to 15.0 eV and a difference of from 9.0 to 15.0 eV in level between a highest occupied molecular orbital (HOMO) and a lowest unoccupied molecular orbital (LUMO), both determined by computational chemistry. The resin composition shows excellent charging characteristics even without a charge control agent or with a charge control agent in a reduced amount. A toner containing the resin composition is also provided.

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Kanagawa-ken, Japan

Junko Tobita