Patents by Inventor Junko Tobita

Junko Tobita has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Resin composition for electrophotographic toner, and toner
    Patent number: 6011119
    Abstract: 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.
    Type: Grant
    Filed: July 19, 1996
    Date of Patent: January 4, 2000
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Katsuru Matsumoto, Nobuhiro Hirayama, Eishi Tanaka, Junko Tobita