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. 05, 1990
Filed:
Jun. 15, 1989
Balram Dhawan, St. Louis, MO (US);
Derek Redmore, St. Louis, MO (US);
John L Przybylinski, St. Louis, MO (US);
Petrolite Corporation, St. Louis, MO (US);
Abstract
A method for preparation of an aminomethylene phosphonate useful as a scale inhibitor in high brine environments. The method comprises phosphonomethylating an amine of the formula ##STR1## wherein x is an integer from 1 to 6 and the Z's are selected from the group consisting of hydrogen and --CH.sub.3, to produce an aminomethylene phosphonate of the formula ##STR2## wherein x and the Z's are defined as above and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are indepenedently selected from the group consisting of hydrogen and --CH.sub.2 PO.sub.3 H.sub.2, such that at least about 80% of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 in a mixture of the aminomethylene phosphonate is --CH.sub.2 PO.sub.3 H.sub.2. Related methods and compositions are also disclosed.