Patents Assigned to Mitsubishi Oil Company, Limited
  • Patent number: 5728655
    Abstract: A refrigerating machine oil composition for vapor compression type refrigerating machines is disclosed which can be used with either of HCFC refrigerants and HFC refrigerants. The inventive machine oil composition comprises a polyol ester (ester compound) as a base oil. Furthermore, the base oil contains from 1.0 to less than 5.0% by weight of a phosphate, from 0.1 to 2.0% by weight of an alkyl phosphorothionate and/or an aryl phosphorothionate, and from 0.05 to 2.0% by weight of an epoxy compound. The composition is free from sludge formation and insufficient lubricity, which are drawbacks of the polyol ester, due to the synergistic effect of these additives. On the other hand, the inventive composition provides the desirable properties of a polyol ester base oil, namely, good compatibility with refrigerants, high electrical insulating properties, and low hygroscopicity.
    Type: Grant
    Filed: January 19, 1996
    Date of Patent: March 17, 1998
    Assignees: Mitsubishi Oil Company, Limited, Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Masayoshi Muraki, Yukiharu Beppu, Shozaburo Konishi, Takayoshi Hamada, Nobuo Murata, Norimasa Nishiura
  • Patent number: 5653909
    Abstract: A refrigerating machine oil composition suitable for a compressor using a hydrofluorocarbon as a refrigerant, which comprises 100 parts by weight of a polyol ester as a base oil, from 7.0 to 15.0 parts by weight of a phosphate, and from 0.2 to 3.0 parts by weight in total of a 1,2-epoxyalkane and/or a vinylcyclohexene dioxide. The use of the refrigerating machine oil composition improves wear resistance of sliding portions of compressors and is free from the formation of sludges derived from the polyol ester used as a base oil of the oil composition. A rotary compressor using the oil composition is also disclosed.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: August 5, 1997
    Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Oil Company, Limited
    Inventors: Masayoshi Muraki, Yukiharu Beppu, Shozaburo Konishi, Susumu Kawaguchi, Noboru Masuda, Sou Suzuki
  • Patent number: 4514544
    Abstract: A paper sizing agent is disclosed. The sizing agent is obtained by alkali saponification of a reaction product which is obtained by reacting a propylene oligomer with maleic anhydride under heating in the absence of a catalyst. The propylene oligomer contains substantially no oligomers having 10 or less carbon atoms. Further, the content of oligomers having 11 to 12 carbon atoms is 0 to 30% by volume, the content of oligomers having 13 to 15 carbon atoms is 20 to 95% by volume and the content of oligomers having 16 to 21 carbon atoms is 5 to 50% by volume. The paper sizing agent provides a homogeneous transparent sizing agent, which restrains the amount of the foaming and also has improved sizing effects.
    Type: Grant
    Filed: December 5, 1983
    Date of Patent: April 30, 1985
    Assignee: Mitsubishi Oil Company, Limited
    Inventors: Yoshio Takahashi, Takeshi Shoji
  • Patent number: 4495089
    Abstract: A continuous process for the production of a solvent for use in the liquefaction of coal is described. The process comprises hydrogenating a mixture of 100 parts by weight of a hydrocarbon mixture and from 0.2 to 10 parts by weight of phenol and/or alkylphenol. The hydrocarbon mixture contains at least 50% by weight of a polycyclic (from tricyclic to pentacyclic) aromatic hydrocarbon or its alkyl derivative. The hydrocarbon mixture is distilled away in a proportion of at least 80% when heated at a temperature of from 320.degree. to 550.degree. C. The hydrogenation of the hydrocarbon mixture and phenol and/or alkylphenol may be carried out with or without the addition of from 0.05 to 0.
    Type: Grant
    Filed: September 10, 1982
    Date of Patent: January 22, 1985
    Assignee: Mitsubishi Oil Company, Limited
    Inventors: Hiroyuki Ihara, Kazuo Takahashi, Michiro Matsubara, Fumio Kumata, Yoshitomo Sanami