The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 13, 2004
Filed:
Nov. 12, 1997
Applicant:
Inventors:
Takehide Tsuda, Osaka, JP;
Takeo Matsumoto, Osaka, JP;
Yoshinori Tanaka, Osaka, JP;
Satoshi Komatsu, Osaka, JP;
Satoshi Koyama, Osaka, JP;
Assignee:
Daikin Industries Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D 3/36 ; C07C 1/7386 ;
U.S. Cl.
CPC ...
B01D 3/36 ; C07C 1/7386 ;
Abstract
Hydrogen fluoride is effectively removed from a mixture of hydrogen fluoride, dichloromethane, chlorofluoromethane and/or difluoromethane by distilling the mixture so that two-component azeotropic mixtures of hydrogen fluoride and dichloromethane, hydrogen fluoride and chlorofluoromethane and hydrogen fluoride and difluoromethane are removed, or by liquid-separating the mixture into an upper liquid phase rich in hydrogen fluoride and a lower liquid phase not rich in hydrogen fluoride before each liquid phase is distilled as described above.