Patents by Inventor Katsuya Takigawa

Katsuya Takigawa 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: 20070032391
    Abstract: The refrigerating machine oil composition of the invention is characterized by comprising a prescribed base oil, a phosphorus-based extreme pressure agent and an oil agent. The refrigerating machine oil composition of the invention having this construction exhibits excellent lubricity for refrigerating/air conditioning devices employing refrigerants such as HFCs, and allows the refrigerating/air conditioning devices to be operated in a stable manner for prolonged periods.
    Type: Application
    Filed: July 29, 2004
    Publication date: February 8, 2007
    Inventors: Kazuo Tagawa, Katsuya Takigawa
  • Patent number: 7045490
    Abstract: A refrigerating machine oil composition according to the invention comprises an alicyclic polycarboxylic acid ester compound obtained from the following compounds (a) to (c): (a) an alicyclic polycarboxylic acid having an alicyclic ring and two or more carboxyl groups, or its derivative, wherein at least two of the carboxyl groups are bonded to mutually adjacent carbon atoms on the alicyclic ring; (b) a compound with two or more hydroxyl groups or its derivative; and (c) a compound with one hydroxyl group or its derivative. It can be used together with HFC refrigerants and natural refrigerants such as carbon dioxide and hydrocarbons, to provide a satisfactory balance between all of the properties of lubricity, miscibility with refrigerants, heat and hydrolytic stability and electric insulating property.
    Type: Grant
    Filed: July 18, 2001
    Date of Patent: May 16, 2006
    Assignee: Nippon Oil Corporation
    Inventors: Yuji Shimomura, Katsuya Takigawa
  • Patent number: 6936576
    Abstract: A refrigerating machine oil for a carbon dioxide refrigerant according to the invention is a refrigerating machine oil comprising polyalkylene glycol represented by the following general formula (1): R1{—(OR2)n—OH}m??(1) [where R1 represents a residue of an organic compound having a hydroxyl group, from which the hydroxyl group has been removed, R2 an alkylene group, and m and n respective integers], wherein a number average molecular weight of the polyalkylene glycol is not less than 500 nor more than 5000, wherein a rate of ethylene group among the alkylene group in the polyalkylene glycol is more than 0 and not more than 80 mol %, and wherein a rate of molecules in which the alkylene group bonded to a terminal hydroxyl group in the polyalkylene glycol is an ethylene group, is not more than 20 mol %.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: August 30, 2005
    Assignee: Nippon Mitsubishi Oil Corporation
    Inventors: Tomomasa Ohsumi, Katsuya Takigawa
  • Patent number: 6831045
    Abstract: The refrigerating machine oil composition of the present invention is a refrigerating machine oil composition comprising an alicyclic dicarboxylic acid ester compound containing an alicyclic ring and two ester groups represented by the following general formula (1): —COOR1  (1) where R1 represents a hydrocarbon group of 1-30 carbons, the two ester groups bonded to mutually adjacent carbon atoms on the alicyclic ring, wherein the molar ratio of cis-forms and trans-forms for the orientation of the two ester groups of the alicyclic dicarboxylic acid ester compound is from 20/80 to 80/20. When used together with HFC refrigerants and natural refrigerants such as carbon dioxide and hydrocarbons, it can yield a refrigerant machine oil composition with excellent lubricity, miscibility with refrigerants, heat and hydrolytic stability and electric insulating property, which can also provide high efficiency to refrigeration systems.
    Type: Grant
    Filed: January 23, 2003
    Date of Patent: December 14, 2004
    Assignee: Nippon Oil Corporation
    Inventors: Yuji Shimomura, Katsuya Takigawa
  • Publication number: 20030166478
    Abstract: A refrigerating machine oil composition according to the invention comprises an alicyclic polycarboxylic acid ester compound obtained from the following compounds (a) to (c):
    Type: Application
    Filed: January 23, 2003
    Publication date: September 4, 2003
    Inventors: Yuji Shimomura, Katsuya Takigawa
  • Publication number: 20030146407
    Abstract: The refrigerating machine oil composition of the present invention is a refrigerating machine oil composition comprising an alicyclic dicarboxylic acid ester compound containing an alicyclic ring and two ester groups represented by the following general formula (1):
    Type: Application
    Filed: January 23, 2003
    Publication date: August 7, 2003
    Inventors: Yuji Shimomura, Katsuya Takigawa
  • Publication number: 20020115577
    Abstract: A refrigerating machine oil for a carbon dioxide refrigerant according to the invention is a refrigerating machine oil comprising polyalkylene glycol represented by the following general formula (1):
    Type: Application
    Filed: October 16, 2001
    Publication date: August 22, 2002
    Inventors: Tomomasa Ohsumi, Katsuya Takigawa
  • Publication number: 20020098993
    Abstract: A refrigerating machine oil for a carbon dioxide refrigerant according to the present invention contains polyalkylene glycol represented by the following general formula (1):
    Type: Application
    Filed: November 21, 2001
    Publication date: July 25, 2002
    Applicant: Nippon Mitsubishi Oil Corporation
    Inventors: Tomomasa Ohsumi, Katsuya Takigawa
  • Patent number: 6251300
    Abstract: A refrigerator oil composition for use with an HFC refrigerant containing HFC-134a, HFC-125 or a mixture thereof, which comprises component (A) and component (B), said component (A) being 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight, based on the total weight of component (A), of alkylbenzenes having a molecular weight of 200 to 350 and said component (B) being 30 to 1% by weight of at least one synthetic oil containing oxygen selected from the group consisting of an ester, a polyalkylene glycol, an alkyl ether of the polyalkylene glycol, a modified compound of polyglycol, a ketone, a polyphenyl ether, a silicone, a polysiloxane and a perfluoro ether.
    Type: Grant
    Filed: June 9, 1998
    Date of Patent: June 26, 2001
    Assignee: Nippon Mitsubishi Oil Corporation
    Inventors: Katsuya Takigawa, Umekichi Sasaki, Satoshi Suda
  • Patent number: 6207071
    Abstract: A refrigerator oil for use with an HFC refrigerant containing HFC-134a and/or HFC-125, which comprises an alkylbenzene oil containing at least 60% by weight of alkylbenzenes having a molecular weight of 200 to 350. An oil composition for use in a refrigerator, which comprises the refrigerator oil mentioned above and an HFC refrigerant containing HFC-134a and/or HFC-125, together with or without an additive such as a phosphoric ester compound.
    Type: Grant
    Filed: October 3, 1997
    Date of Patent: March 27, 2001
    Assignee: Nippon Mitsubishi Oil Corporation
    Inventors: Katsuya Takigawa, Umekichi Sasaki, Satoshi Suda
  • Patent number: 5817251
    Abstract: A refrigerating machine oil for use with a hydrofluorocarbon refrigerant in a refrigerator, which comprises at least one member selected from the group consisting of hydrocarbon compounds represented by the following general formulas (1), (2) and (3) ##STR1## (wherein R represents an alkylene group or alkenylene group having 1 to 8 carbon atoms; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be the same or different and are each a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, the total number of carbon atoms of R, R.sup.1, R.sup.2 R.sup.3 and R.sup.4 being within a range of 1 to 8; and R.sup.6, R.sup.7, R.sup.8 and R.sup.9 may be the same or different and are each a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, the total number of carbon atoms of R.sup.6, R.sup.7, R.sup.8 and R.sup.9 being within a range of 1 to 10).
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: October 6, 1998
    Assignee: Nippon Oil Co., Ltd.
    Inventors: Katsuya Takigawa, Umekichi Sasaki, Satoshi Suda
  • Patent number: 5746933
    Abstract: A lubricating oil for refrigerating machines comprises polyoxyalkylene compounds represented by the formula (I): ##STR1## Wherein A is a residue obtained from a compound which has both a heterocyclic ring having an ether linkage therein and hydroxyl groups by eliminating the hydroxyl groups from the compound; R.sup.1 and R.sup.2 are each an alkylene group; R.sup.3 is an alkyl group; R.sup.4 is hydrogen atom or an alkyl group; a and b are each a positive integer and l, m, and n are each an integer of 0 or more; and a.multidot.1+b.multidot.m=2 to 100 and l+m+n=2 to 20; further,the polyoxyalkylene compounds have a hydroxyl value ranging from 0 to 30.0 mgKOH/g and satisfies the following formula (1)0.5<p/(p+q)<1.0 (1)wherein p is the number of butylene groups represented by R.sup.1 and R.sup.2, and q is the number of all alkylene groups excluding the butylene groups.
    Type: Grant
    Filed: November 3, 1995
    Date of Patent: May 5, 1998
    Assignee: Nippon Oil Co., Ltd.
    Inventors: Noboru Ishida, Umekichi Sasaki, Katsuya Takigawa, Satoshi Suda
  • Patent number: 5711895
    Abstract: A refrigerating machine oil for use with a hydrofluorocarbon refrigerant in a refrigerator, which comprises at least one member selected from the group consisting of hydrocarbon compounds represented by the following general formulas (1), (2) and (3) ##STR1## (wherein R represents an alkylene group or alkenylene group having 1 to 8 carbon atoms; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be the same or different and are each a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, the total number of carbon atoms of R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 being within a range of 1 to 8; and R.sup.6, R.sup.7, R.sup.8 and R.sup.9 may be the same or different and are each a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, the total number of carbon atoms of R.sup.6, R.sup.7, R.sup.8 and R.sup.9 being within a range of 1 to 10).
    Type: Grant
    Filed: December 4, 1995
    Date of Patent: January 27, 1998
    Assignee: Nippon Oil Co., Ltd.
    Inventors: Katsuya Takigawa, Umekichi Sasaki, Satoshi Suda