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. 10, 2012
Filed:
Jun. 21, 2005
Toshio Nakayama, Sodegaura, JP;
Junpei Tsuji, Chiba, JP;
Noriaki Oku, Ichihara, JP;
Koji Shinohara, Ichihara, JP;
Toshio Nakayama, Sodegaura, JP;
Junpei Tsuji, Chiba, JP;
Noriaki Oku, Ichihara, JP;
Koji Shinohara, Ichihara, JP;
Sumitomo Chemical Company, Limited, Tokyo, JP;
Abstract
A method of purifying propylene oxide, which comprises subjecting the propylene oxide containing methyl formate as an impurity to extractive distillation using a hydrocarbon of 7 to 10 carbon atoms as an extractant with an extractive distillation column, adding water to the distillate from the overhead of the extractive distillation column to conduct oil-water separation, recycling the oil layer separated to the extractive distillation column, removing the aqueous layer outside the system thereby to obtain propylene oxide in which a methyl formate concentration is reduced as a bottom liquid of the extractive distillation column.