Mitsui Toatsu Chemicals, Incorporated

Nippondenso Co., Ltd.

Tokyo Gas Company Limited

Akio Fujiwara

Masaaki Shin

Kenji Uchiyama

Akira Misawa

Shoji Kawasaki

Nobuhiro Hirayama

Hiroshi Taniwaki

Hiroshi Haraguchi

Keiichi Ishikawa

Kazuo Hisamatsu

Masakazu Hishinuma

Hisatomo Sato

Kazumi Ishida

An air fuel ratio controlling apparatus for an internal combustion engine, comprises: a catalytic converter, provided in an exhaust system for purifying an exhaust gas of the engine; a first oxygen density sensor, provided upstream from the catalytic converter in the exhaust system, responsive to a first oxygen density of a first exhaust gas of the engine for detecting whether an air fuel ratio of the engine is in a rich condition or a lean condition with respect to a theoretical air fuel ratio of the engine; a second oxygen density sensor, provided downstream from the catalytic converter in the exhaust system, responsive to a second oxygen density of a second exhaust gas passed through the catalytic converter for detecting whether the air fuel ratio of the engine is in a rich or a lean condition with respect to a theoretical air fuel ratio of the engine; and an air fuel ratio control portion for controlling the air fuel ratio in accordance with the detection results of the first and second oxygen sensors, wherein; the first oxygen sensor has a function for oxidizing and reducing a specific component more powerful than that of the second oxygen density sensor.

Air fuel ratio control apparatus for an internal combustion engine

This invention discloses electrophotographic toners and the methods for their preparation. The electrophotographic toners contain resin and coloring agents as primary components. The resin is a non-crosslinked polymer of vinyl monomers or its mixtures, and has a number average molecular weight (Mn) of 2,000-15,000, a Z average molecular weight (Mz) of not less than 400,000 and Mz/Mn of 50-600. The electrophotographic toners exert an excellent fixing ability at high duplication speed or at lower temperatures.

Electrophotographic toner production process

Electrophotographic toner

An electrophotographic toner, which can exhibit good fixation in high-speed copying and is not affected by an environment such as high humidity, is provided by containing, as a principal component thereof, a resin blend composed of (a) 40-90 wt. % of a vinyl copolymer (I) formed of 70-97 wt. % of an aromatic vinyl monomer, 3-30 wt. % of an alkyl fumarate which is an C.sub.1-8 monoalkyl or dialkyl ester and 0-5 wt. % of an acid monomer and having a number average molecular weight of 2,000-15,000 and (b) 10-60 wt. % of a vinyl polymer (II) having a number average molecular weight of 20,000-500,000.

Electrophotographic toner for high speed electrophotography

Toner composition for the electrophotography

An electrophotographic toner, which can exhibit good fixation in high-speed copying and is not affected by an environment such as high humidity, is provided by containing, as a principal component thereof, a resin blend composed of (a) 40-90 wt. % of a vinyl copolymer (I) formed of 70-97 wt. % of an aromatic vinyl monomer, 3-30 wt. % of an alkyl fumarate which is a C.sub.1-8 monoalkyl or dialkyl ester and 0-5 wt. % of an acid monomer and having a number average molecular weight of 2,000-15,000 and (b) 10-60 wt. % of a vinyl polymer (II) having a number average molecular weight of 20,000-500,000.

Electrophotographic process uses toner comprising vinyl copolymer

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Yokohama, Japan

Akio Fujiwara