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:
May. 31, 1983
Filed:
Nov. 10, 1981
Toshikazu Kawai, Kamifukuoka, JP;
Yutaka Maruyama, Kamifukuoka, JP;
Junji Negishi, Kawagoe, JP;
Akira Negishi, Sayama, JP;
Central Glass Company Limited, Ube, JP;
Abstract
Crude hexafluoroacetone (HFA) containing chlorofluoroacetone(s) (CFA) as well as hydrogen halide(s) is purified by initially allowing the crude HFA to be absorbed in water to give an aqueous solution in which HFA and CFA are in the form of their respective hydrates, adding a calcium compound such as carbonate, hydroxide or oxide to the solution to neutralize the hydrogen halide(s), and decomposing the hydrated CFA by first adding an alkali metal compound such as K.sub.2 CO.sub.3 or Na.sub.2 CO.sub.3 or an alkaline earth metal compound such as Ca(OH).sub.2, Ba(OH).sub.2, CaO or BaO to the solution and subsequently adding a mineral acid such as HCl or H.sub.2 SO.sub.4 to the same solution. This procedure results in complete decomposition of CFA without causing decomposition of HFA and spontaneous separation of the liquid reaction system into two layers, one of which is exclusively HFA hydrate. Accordingly it is easy to separate pure HFA hydrate from the decomposed impurities.