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:
Feb. 12, 2002
Filed:
Apr. 13, 1999
Applicant:
Inventors:
Takehide Tsuda, Osaka, JP;
Takashi Shibanuma, Osaka, JP;
Assignee:
Daikin Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C 1/7383 ; C07C 5/144 ; B01D 3/00 ;
U.S. Cl.
CPC ...
C07C 1/7383 ; C07C 5/144 ; B01D 3/00 ;
Abstract
A process for refining difluoromethane by removing water which is contained in difluoromethane and has been believed to be difficult to be removed includes distilling difluoromethane which contains water so as to obtain difluoromethane as a distillate and a mixture as a bottom product of difluoromethane and chlorofluoromethane and/or dichloromethane which mixture contains water. The bottom product is recycled to a reaction step to be reused together with a feedstock.