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:
Apr. 04, 1989
Filed:
Jan. 06, 1988
Joginder N Anand, Clayton, CA (US);
Darrell C Feay, Orinda, CA (US);
Stephen E Bales, Midland, MI (US);
Thomas O Jeanes, Antioch, CA (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
The invention is an improved gas separation membrane comprising a thin, discriminating layer consisting predominantly of a carbonate polymer derived from a bisphenol corresponding to Formula I ##STR1## wherein R at each occurrence is independently H, Cl, Br, or C.sub.1 -C.sub.4 alkyl and R.sup.1 is ##STR2## --S--, --SO.sub.2 --, --O--, or a C.sub.1 -C.sub.6 divalent hydrocarbon or a C.sub.1 -C.sub.6 divalent fluorocarbon radical or inertly substituted hydrocarbon radical, with the proviso that at least 25 weight percent of the moieties derived from the bisphenol of Formula I present in the discriminating layer bear R groups which are exclusively Br or Cl, the gas separation membrane exhibiting a separation factor for oxygen and nitrogen at 24.degree. C. of at least 6.1. In another aspect this invention relates to a process for separating oxygen from nitrogen, or a nitrogen-containing gas.