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:
Jun. 01, 1982
Filed:
Sep. 22, 1980
Applicant:
Inventors:
William E Starner, Freeland, PA (US);
Walter F Yext, Mahanoy City, PA (US);
Assignee:
Air Products and Chemicals, Inc., Allentown, PA (US);
Primary Examiner:
Int. Cl.
CPC ...
C07F / ;
U.S. Cl.
CPC ...
260403 ; 560266 ; 2605 / ;
Abstract
Acylated 1-hydroxyalkylidene-1, 1-diphosphonic acid (HADPA) can be produced almost instantaneously with less than 5% (by weight) phosphorus acid byproduct by introducing PX.sub.3 (where X is a halide) into a reactor containing R--COOH at or above a specified temperature. The acylated HADPA can then be hydrolyzed and substantially pure HADPA obtained by vacuum distillation. Of particular importance is the addition of PCl.sub.3 to acetic acid at a temperature of between 105.degree. C. and 120.degree. C. to produce acetylated 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDPA).