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. 01, 1980
Filed:
Feb. 07, 1979
Hoechst Aktiengesellschaft, Frankfort am Main, DE;
Abstract
Bisphosphinic acid anhydrides of the formula ##STR1## in which R is a saturated open chain or cyclic alkylene radical, an arylene or aralkylene radical, and R.sup.1 and R.sup.2, which may be identical or different, represent optionally halogen substituted alkyl, aryl or aralkyl radicals, and m represents an integer .gtoreq.1, preferably .gtoreq.2 and a process for their preparation which comprises reacting bisphosphinic acid derivatives of the formula ##STR2## in which R.sup.3 and R.sup.4, are hydrogen, monovalent cations, the ammonium group or optionally halogen-substituted alkyl groups, with inorganic acid chlorides and/or with phosgene and/or with oxalyl chloride and/or with the corresponding bromine compounds in a molar ratio of about 1:1 at a temperature up to 250.degree. C.