Patents by Inventor Keiji Okada

Keiji Okada 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).

  • Patent number: 6525007
    Abstract: The present invention is intended to obtain a viscosity modifier for a lubricating oil, by the use of which a lubricating oil composition of excellent low-temperature properties can be obtained, and to obtain a lubricating oil composition of excellent low-temperature properties containing the viscosity modifier. The viscosity modifier for a lubricating oil comprises an ethylene/propylene copolymer (A) having the properties: the density is in the range of 857 to 882 kg/m3, Mw is in the range of 80,000 to 400,000, Mw/Mn is not more than 2.3, and the density (D (kg/m3)) and the melting point (Tm (° C.)) satisfy the relation Tm≦1.247×D−1037; or comprises an ethylene/propylene copolymer (B) having the properties: the ethylene content is in the range of 70 to 79 wt %, Mw is not less than 80,000 and less than 250,000, Mw/Mn is not more than 2.3, Tm is in the range of 15 to 60° C., and the ethylene content (E (wt %)) and the melting point (Tm (° C.)) satisfy the relation 3.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: February 25, 2003
    Assignees: Mitsui Chemicals, Inc., The Lubrizol Corporation
    Inventors: Keiji Okada, Ryousuke Kaneshige
  • Patent number: 6516612
    Abstract: An exhaust gas purification device including three-way catalysts connected to engine cylinder groups and arranged in parallel, and a NOx trapping catalyst connected with the three-way catalysts downstream thereof. A controller controls fuel injection for making an A/F ratio of exhaust gas flowing into one of the three-way catalysts rich relative to a stoichiometric A/F ratio when it is required to reduce the NOx trapped by the NOx trapping catalyst.
    Type: Grant
    Filed: February 2, 2000
    Date of Patent: February 11, 2003
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Tarou Yokoi, Hirofumi Tsuchida, Keiji Okada, Kouji Ishihara
  • Publication number: 20030018355
    Abstract: An intravascular obstruction removing wire includes an elongate wire body, at least two non-branched wire portions having distal ends and proximal ends which are connected to a distal end of the wire main body, and a plurality of filament portions extending across the wire portions. The non-branched wire portions and the filament portions form a trapping portion. The trapping portion is deformable from a large-diameter state in which the non-branched portions branch to the distal end of the wire body forward in different directions and the filament portions are separated from each other, so that a space surrounded by the non-branched wire portions and the filament portions is formed to trap therein an obstruction in a blood vessel, to a small-diameter state in which the non-branched wire portions are positioned so that a distance between the wire portions is smaller than that of the wire portions in the large-diameter state.
    Type: Application
    Filed: July 1, 2002
    Publication date: January 23, 2003
    Inventors: Katsuya Goto, Takashi Kaneko, Takeshi Kanamaru, Masahiro Takeuchi, Keiji Okada
  • Patent number: 6497846
    Abstract: An exhaust gas purifying system for a cylinder direct internal combustion engine having a fuel injector valve for directly injecting fuel into a combustion chamber of the engine. The exhaust gas purifying system comprises an adsorbent catalytic converter disposed in an exhaust gas passageway of the engine. The adsorbent catalytic converter including a catalytic element having an adsorption layer. The adsorption layer contains an adsorbent for adsorbing HC (hydrocarbons) of exhaust gas in a first temperature range and to release the adsorbed HC in a second temperature range which is high relative to the first temperature range, and a catalyst component for promoting reaction for oxidizing HC which is released from the adsorbent.
    Type: Grant
    Filed: August 10, 1999
    Date of Patent: December 24, 2002
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Keiji Okada, Kazuhiko Kanetoshi, Hirofumi Tsuchida, Akira Tayama
  • Patent number: 6462136
    Abstract: The present invention is intended to provide an ethylene copolymer having excellent mechanical properties and moldability, a process for preparing the copolymer, a resin composition containing the copolymer and uses thereof. The ethylene copolymer has the following properties: the copolymer comprises 90 to 99% by mol of ethylene constituent units and 1 to 60% by mol of C3-20 &agr;-olefin constituent units; the ratio (Mz/Mw) of a Z average molecular weight (Mz) to a weight-average molecular weight (Mw), each molecular weight being measured by GPC, is in the range of 10 to 30, and said ratio (Mz/Mw) and the ratio (Mw/Mn) of a weight-average molecular weight (Mw) to a number-average molecular weight (Mn), each molecular weight being measured by GPC, satisfy the relation (Mz/Mw)>(Mw/Mn); the intrinsic viscosity is in the range of 0.5 to 9 dl/g; the ratio (n*0.01/n*8) of a melt viscosity (&eegr;*0.01) at a shear rate of 0.01 rad/sec, as measured at 190° C.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: October 8, 2002
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Junji Saito, Keiji Okada, Kenichi Morizono, Makoto Mitani, Terunori Fujita
  • Patent number: 6391413
    Abstract: The present invention provides a raw rubber lapping film formed of an ethylene·&agr;-olefin random copolymer comprising ethylene unit and an &agr;-olefin unit having 4 to 20 carbon atoms and a raw rubber bale lapped with this film. Since the film is superior in strength and release properties and has good dispersibility in ethylene·&agr;-olefin copolymer rubber, the operation of lapping raw rubber with a film, the operation of stripping a film from a lapped raw rubber bale and the operation of separating each of a plurality of raw rubber bales are carried out easily and yet there is no adverse effect on the subsequent rubber processing step without stripping the film by heating at a temperature higher than the melting point of the film at the time of kneading.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: May 21, 2002
    Assignee: Mitsui Chemicals Inc
    Inventors: Keiji Okada, Yoshiharu Kikuchi, Takashi Hakuta
  • Publication number: 20020055445
    Abstract: A viscosity modifier for lubricating oils which is capable of giving a lubricating oil composition excellent low-temperature properties; and a lubricating oil composition which contains the viscosity modifier and has excellent low-temperature properties. The modifier comprises of any of ethylene/propylene copolymers (A), (B) and (C). The composition comprises a combination of any of the ethylene/propylene copolymers (A), (B) and (C) with a lube base oil (D), and optionally a pour point depressant (E).
    Type: Application
    Filed: June 8, 2001
    Publication date: May 9, 2002
    Inventors: Keiji Okada, Ryousuke Kaneshige
  • Patent number: 6368551
    Abstract: The method for preparation of sintered permanent magnets according to the present invention comprises the steps of: mixing fully fine powder of a crystalline mother alloy for permanent magnet containing a rare-earth element, Fe and B as the essential components with fine powder of zinc oxide, compaction molding the resulted mixture in the presence of a magnetic field, sintering the compacted mixture in vacuum to cause generation of oxygen and metallic zinc by thermal decomposition of the zinc oxide; segregation of a part of metallic component in the mother alloy at the boundary and inside of the mother alloy crystal; formation of amorphous metallic oxide by forced oxidation of the segregated metal with the generated oxygen; crystallization of the amorphous metallic oxide; formation of an epitaxial junction between the crystallized metallic oxide and the mother alloy crystal; and evaporation of the metallic zinc into the vacuum, and quenching the sintered compact.
    Type: Grant
    Filed: August 16, 2000
    Date of Patent: April 9, 2002
    Assignee: Sanei Kasei Co., Ltd.
    Inventors: Shigenobu Sekine, Yuko Kawasaki, Yoshiki Kuwabara, Hiroji Sato, Minoru Narita, Kazushi Suzuki, Koichi Tono, Keiji Okada, Kenji Sakaguchi, Mitsuhisa Hirata
  • Publication number: 20020035044
    Abstract: The lubricating oil composition of the invention comprises a lubricating oil base (A) and a copolymer (B) of ethylene and an &agr;-olefin of 3 to 20 carbon atoms.
    Type: Application
    Filed: September 28, 2001
    Publication date: March 21, 2002
    Inventors: Keiji Okada, Ryousuke Kaneshige
  • Patent number: 6310164
    Abstract: Unsaturated copolymer which is a copolymer of an &agr;olefin of 2 to 12 carbon atoms and a conjugated diene monomer represented by the following formula (I-a) and has the properties: (a) in said copolymer, 1,2-addition units (including 3,4-addition units) derived from the conjugated diene monomer (I-a) form double bonds in the side chain of the copolymer, 1,4-addition units derived from the conjugated diene monomer (I-a) form double bonds in the main chain of the copolymer, and the quantity ratio of the double bonds of the side chain derived from the 1,2-addition units to the double bonds of the main chain derived from the 1,4-addition units (side chain double bonds derived from 1,2-addition units/main chain double bonds derived from 1,4-addition units) is in the range of 10/90 to 99/1 (b) five-membered rings are present in the main chain of said copolymer; and (c) the quantity ratio of the double bonds from all of the addition units to the five-membered rings (total of double bonds from all addition units/fi
    Type: Grant
    Filed: July 20, 1998
    Date of Patent: October 30, 2001
    Assignee: Mitsu Chemicals INC
    Inventors: Kenichi Morizono, Keiji Okada, Masayoshi Yamaguchi
  • Patent number: 6303727
    Abstract: A novel and useful linear triene compound represented by the following formula (1) is co-polymerized with an &agr;-olefin to obtain an ethylenically unsaturated copolymer which is superior in weather-ability, heat resitance and fastness to ozone, together with superior scorch stability and vulcanizability at high velocity in which R1, R2, R3, R4, R5 and R6 stand each, independently of each other, for hydrogen atom or an alkyl having 1-3 carbon atoms, R7 represents an alkyl having 1-3 carbon atoms and n is an integer of 0-5, with the proviso that each of R4s or of R5s may be identical with or different from each other, respectively, when n is 2 or greater.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: October 16, 2001
    Assignee: Mitsui Chemicals Inc.
    Inventors: Ken Maeda, Masaaki Yasuda, Terunori Fujita, Keiji Okada, Makoto Kamimura, Kazuyuki Takimoto, Hidetatsu Murakami, Masaaki Kawasaki, Keiji Watanabe
  • Patent number: 6300416
    Abstract: A rubber composition useful as a tire side wall or tire tread is formed from an unsaturated olefin copolymer (A) or (A′) and diene rubber (B). Copolymers (A) and (A′) are each obtained from (i) ethylene, (ii) aromatic vinyl compound, (iii) non-conjugated polyene, and, optionally (iv) alpha-olefin having at least 3 carbon atoms. When used in forming a tire side wall, copolymer (A) has a molar ratio of (i)/(iv) from 100/0 to 40/60; molar ratio of [((i)+(iv))/(ii)] from 98/2 to 60/40; an intrinsic viscosity, measured in decalin, at 135° C., from 1.0 to 6.0 dl/g; and iodine value from 10 to 50. For use in tire tread, copolymer (A′), has a molar ratio (i)/(iv) from 100/0 to 40/60; molar ratio [((i)+(iv)):(ii)] from 99/1 to 85/15. The weight ratio (A′)/(B) is from 1/99 to 50/50. The compositions for tire side wall are characterized by excellent strength properties and bending fatigue resistance and low fuel consumption.
    Type: Grant
    Filed: September 17, 1998
    Date of Patent: October 9, 2001
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Keiji Okada, Kenichi Morizono, Kazuyuki Takimoto, Tetsuhiro Matsumoto, Masaaki Kawasaki, Tetsuo Tojo
  • Patent number: 6289673
    Abstract: A catalyst in an exhaust passage for an engine is capable of storing oxygen. A memory stores, as an oxygen storage capacity, an oxygen storage amount at the time of change of the downstream air-fuel ratio on the downstream side of the catalyst from stoichiometric to lean. A processor calculates the current oxygen storage amount accurately in due consideration of a fast oxygen absorbing rate in the case of the downstream air-fuel ratio being stoichiometric, and a slow oxygen absorbing rate in the case of the downstream air-fuel ratio being lean, and controls the air-fuel ratio of the exhaust gas mixture flowing into the catalyst so as to bring the oxygen storage amount in a region under the oxygen storage capacity.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: September 18, 2001
    Assignee: Nissan Motor Co., LTD
    Inventors: Akira Tayama, Hirofumi Tsuchida, Kazuhiko Kanetoshi, Keiji Okada
  • Patent number: 6235818
    Abstract: A hot melt adhesive composition exhibiting excellent adhesive strength and which is useful as an adhesive for styrene resins contains (B) tackifier and (C) ethylene/C3-C20 &agr;-olefin/aromatic vinyl compound random copolymer and, in some embodiments also (A) base polymer, such as polyolefin, polar group-containing polymer and aromatic vinyl compound/conjugated diene copolymer. A low molecular weight polyolefin may also be included in all embodiments. The randon copolymer (C) may be prepared by polymerizing the &agr;-olefin and aromatic vinyl compound in the presence of a metallocene containing catalyst. In addition to excellent adhesive strength the hot melt adhesives have improved workability.
    Type: Grant
    Filed: July 29, 1999
    Date of Patent: May 22, 2001
    Assignee: Mitsui Chemicals
    Inventors: Kenichi Morizono, Keiji Okada, Suguru Tokita
  • Patent number: 6220017
    Abstract: An exhaust emission control system for an internal combustion engine is provided. The exhaust emission control system comprises a catalytic converter disposed in an exhaust passage of the engine, a wide-range A/F ratio sensor disposed in the exhaust passage at a location downstream of the catalytic converter for detecting an A/F ratio of a mixture supplied to the engine, and a control unit including a detecting section for detecting the degree of water gas reaction caused in the catalytic converter and a correcting section for correcting a detected value of the A/F ratio on the basis of the degree of water gas reaction.
    Type: Grant
    Filed: June 23, 1999
    Date of Patent: April 24, 2001
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Akira Tayama, Toshikazu Shiino, Hirofumi Tsuchida, Keiji Okada
  • Patent number: 6218469
    Abstract: Disclosed is an unsaturated elastomer composition comprising (A) an unsaturated olefin copolymer of at least one &agr;-olefin of 2 to 20 carbon atoms, a conjugated diene monomer represented by the following formula (I), and optionally, an aromatic vinyl compound, and (B) at least one rubber selected from a diene rubber and an ethylene/&agr;-olefin/nonconjugated polyene copolymer rubber, a weight ratio of said component (A) to said component (B) ((A)/(B)) being in the range of 1/99 to 99/1; wherein R1 and R2 are each independently a hydrogen atom, an alkyl group of 1 to 8 carbon atoms or an aryl group, and at least one of R1 and R2 is a hydrogen atom. From the composition, a vulcanized product excellent in vibration damping properties, vibration insulation properties and strength properties as well as in heat resistance, weathering resistant, ozone resistance and dynamic fatigue resistance can be obtained.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: April 17, 2001
    Assignee: Mitsui Chemicals INC
    Inventors: Kenichi Morizono, Keiji Okada, Masayoshi Yamaguchi
  • Patent number: 6214779
    Abstract: The present invention is directed towards a lubricating oil comprising a random copolymer of an &agr;-olefin/aromatic vinyl compound, wherein the copolymer has a viscosity falling within a specific range and comprises ethylene, an aromatic vinyl compound, and optionally an &agr;-olefin. The lubricating oil possesses excellent viscosity properties, thermal stability, oxidation stability, abrasion resistance, and compatibility with lubricating oil additives. The random copolymer having a different viscosity range is useful as a viscosity index improver and a compatibilizing agent for a lubricating oil. The invention also provides a lubricating oil composition comprising a base oil and the viscosity index improver or the compatibilizing agent. The invention further provides a fuel oil composition comprising a fuel oil fluidity improver based on the above random copolymer having a different viscosity range and a middle fraction fuel oil having a boiling point of 150 to 400° C.
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: April 10, 2001
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Ryousuke Kaneshige, Hideki Hirano, Masahide Tanaka, Kenichi Morizono, Keiji Okada
  • Patent number: 6195867
    Abstract: A method of producing a spiral wound gasket for sealing fluid such as a liquid including water and oil, and a gaseous body including vapor and gas and a device for producing the spiral wound gasket. The tip portion of a hoop material is cut and raised thereby forming a checking stepped-portion. The checking stepped-portion is caught by a checking pawl, so as to wind the hoop material around a core drum. After winding the hoop material around the outer periphery of the core drum, at least once, the checking pawl is retracted from the outer periphery of the core drum, thereby separating the checking pawl from the checking stepped-portion. The spiral wound gasket produced by the present invention exhibits an excellent sealing property. Moreover, it also has an excellent durability.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: March 6, 2001
    Assignee: Nippon Pillar Packing Co., Ltd.
    Inventors: Hideto Hashiguchi, Masahiko Takaoka, Keiji Okada, Shoji Kato, Masao Konaka
  • Patent number: 6194501
    Abstract: Disclosed herein is an olefin copolymer shrink film comprising an &agr;-olefin/aromatic vinyl compound random copolymer. This &agr;-olefin/aromatic vinyl compound random copolymer comprises 99.9 to 58 mol % of structural units derived from ethylene, 0 to 30 mol % of structural units derived from an &agr;-olefin having 3 to 20 carbon atoms (provided that the total of the structural units derived from ethylene and the structural units derived from an &agr;-olefin having 3 to 20 carbon atoms ranges from 99.9 to 88 mol %), and 0.1 to 12 mol % of structural units derived from an aromatic vinyl compound. The &agr;-olefin/aromatic vinyl compound random copolymer has an intrinsic viscosity [&eegr;], as measured in decalin at 135° C., of 0.1 to 10 dl/g and has a melting point, as measured by a differential scanning calorimeter, of 60 to 125° C. The olefin copolymer shrink film is oriented in at least one direction.
    Type: Grant
    Filed: September 23, 1998
    Date of Patent: February 27, 2001
    Assignee: Mitsui Chemicals Inc
    Inventors: Keiji Okada, Kazuyuki Takimoto, Kenichi Morizono
  • Patent number: 6143827
    Abstract: Disclosed is an olefin thermoplastic elastomer composition obtained by dynamically heat treating, in the presence of an organic peroxide, a blend comprising 10 to 60 parts by weight of a crystalline polyolefin resin (A) and 40 to 90 parts by weight of an unsaturated olefin copolymer (B) of at least one .alpha.-olefin of 2 to 20 carbon atoms, a conjugated diene monomer represented by the following formula (I), and optionally, an aromatic vinyl compound, the total amount of said components (A) and (B) being 100 parts by weight; ##STR1## wherein R.sup.1 and R.sup.2 are each independently a hydrogen atom, an alkyl group of 1 to 8 carbon atoms or an aryl group, and at least one of R.sup.1 and R.sup.2 is a hydrogen atom. The composition has excellent moldability and can provide a molded product having excellent elastomeric properties, tensile strength properties and appearance.
    Type: Grant
    Filed: July 20, 1998
    Date of Patent: November 7, 2000
    Assignee: Mitsui Chemicals Inc
    Inventors: Kenichi Morizono, Keiji Okada, Masayoshi Yamaguchi