Patents by Inventor Hirotaka Yamasaki

Hirotaka Yamasaki 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).

  • Publication number: 20180171259
    Abstract: The lubricating oil composition for gas engine of the present invention contains (A) a base oil, (B1) an overbased calcium salicylate, (B2) an overbased sodium sulfonate, (C1) an amine-based antioxidant, and (C2) a phenol-based antioxidant, a total content of the amine-based antioxidant (C1) and the phenol-based antioxidant (C2) being 4 mass % or more on a basis of the whole amount of the composition.
    Type: Application
    Filed: March 13, 2015
    Publication date: June 21, 2018
    Applicant: IDEMITSU KOSAN CO., LTD
    Inventor: Hirotaka YAMASAKI
  • Publication number: 20180051228
    Abstract: The lubricating oil composition for four-stroke cycle engine of the present invention includes a base oil (A) and from 0.5 to 10% by mass of a polyolefin (B) having at least an isobutene-derived constituting unit and having a number average molecular weight of 500 to 10,000, with a sulfated ash content being from 0.3 to 1.2% by mass.
    Type: Application
    Filed: March 31, 2016
    Publication date: February 22, 2018
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventor: Hirotaka YAMASAKI
  • Patent number: 8557751
    Abstract: The lubricating oil composition contains a base oil, a phosphate ester derivative represented by a formula (1) below and a zinc compound. An element ratio (Zn/P) between zinc (Zn) and phosphorus (P) in the lubricating oil composition is 0.55 or more at a mole ratio. In the formula, Y represents S (sulfur) or O (oxygen); R1 represents an organic group having 4 to 24 carbon atoms; R2 represents a divalent organic group having 1 to 6 carbon atoms; and n represents an integer of 1 to 3.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: October 15, 2013
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Hirotaka Yamasaki, Motoharu Ishikawa
  • Publication number: 20100126461
    Abstract: The lubricating oil composition contains a base oil, a phosphate ester derivative represented by a formula (1) below and a zinc compound. An element ratio (Zn/P) between zinc (Zn) and phosphorus (P) in the lubricating oil composition is 0.55 or more at a mole ratio. In the formula, Y represents S (sulfur) or O (oxygen); R1 represents an organic group having 4 to 24 carbon atoms; R2 represents a divalent organic group having 1 to 6 carbon atoms; and n represents an integer of 1 to 3.
    Type: Application
    Filed: April 25, 2008
    Publication date: May 27, 2010
    Applicant: IDEMITSU KOSAN CO., LTD.
    Inventors: Hirotaka Yamasaki, Motoharu Ishikawa
  • Patent number: 6261474
    Abstract: A lubricating oil for compression-type refrigerators using a refrigerant containing pentafluoroethane which lubricating oil comprises a polyvinyl ether compound having (a) a constituting unit represented by general formula (I): or a polyvinyl ether compound having constituting unit (a) and (b) a constituting unit represented by general formula (I′): (wherein R represents a hydrocarbon group which has 1 to 3 carbon atoms and may have ether bond in the group, and R′ represents a hydrocarbon group which has 3 to 20 carbon atoms and may have ether bond in the group) as the main component. The above lubricating oil shows excellent compatibility with hydrofluorocarbon refrigerants containing pentafluoroethane which can replace chlorofluorocarbons causing environmental pollution, has a high volume intrinsic resistance, and exhibits excellent stability and lubricating property.
    Type: Grant
    Filed: February 4, 1997
    Date of Patent: July 17, 2001
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Tatsuya Egawa, Hirotaka Yamasaki, Kenji Mogami, Satoshi Nagao, Toyokazu Handa, Masato Kaneko
  • Patent number: 6087539
    Abstract: A process for producing an ether compound represented by the general formula (II) or (III): ##STR1## wherein R.sup.1 and R.sup.2 represent each an alkyl group or a cycloalkyl group and n represents an integer of 1 to 50, which comprises bringing an acetal compound represented by the general formula (I): ##STR2## into reaction with hydrogen in the presence of a solid catalyst comprising (A) nickel in an amount corresponding to 10 to 70% by weight of metallic nickel, and (B) at least one compound selected from the group consisting of oxides of silicon, aluminum, magnesium, titanium, and zirconium; and synthetic or natural inorganic oxides containing one or more of these oxides as the constituents thereof. A vinyl ether polymer having a terminal ether group can be obtained with a good yield without causing corrosion of the apparatus used for the reaction.
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: July 11, 2000
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Hirotaka Yamasaki, Akihisa Ogawa, Shigeru Kamimori, Yoshikazu Hirao, Keiji Fujita, Tokuyuki Yoshimoto
  • Patent number: 5326488
    Abstract: Disclosed is a substance useful as a detergent-dispersant which has excellent stability at high temperatures and has an oxidation stability, a detergent-dispersant containing the same, a process of producing it, and fuel oil and lubricating oil composition comprising it.
    Type: Grant
    Filed: February 11, 1993
    Date of Patent: July 5, 1994
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Tomiyasu Minokami, Hiroaki Koshima, Hirotaka Yamasaki, Masahisa Gotoh
  • Patent number: 5239107
    Abstract: A process for producing a polycyanoaryl ether powder which comprises reacting a dihalogenobenzonitrile, a dihydric phenol and an alkali metal salt in the presence of a polymerization solvent, and distilling the solvent, while pulverizing the reaction mixture under agitation. The process produces a polycyanoaryl ether powder having excellent physical properties and is useful as a material for electronic appliances, electric appliances and parts of machines.
    Type: Grant
    Filed: April 9, 1992
    Date of Patent: August 24, 1993
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Jitsuo Shinoda, Hirotaka Yamasaki, Toshiharu Takizawa
  • Patent number: 4959487
    Abstract: A process for producing aromatic nitrile, comprising reacting aromatic halide substituted by a nitro group in the ortho position relative to the halogen atom with 0.1 to 0.99 mol of cuprous cyanide and 0.1 to 2.0 mol of alkali cyanide, both being per mol of said aromatic halide, in a polar solvent, the amount of said aprotic solvent being 0.1 to 30 parts by weight per 100 parts by weight of said aromatic halide.
    Type: Grant
    Filed: March 2, 1989
    Date of Patent: September 25, 1990
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Hirotaka Yamasaki, Yoshio Hironaka