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:
Nov. 24, 1987
Filed:
Nov. 24, 1986
Thomas F D'Muhala, Lebanon, CT (US);
Other;
Abstract
The invention provides a process for the sequestration of barium sulfate scale and barium sulfate sequestrant compositions therefor comprising an aqueous solution of citric acid (CA), a polycarbazic acid (PA), and an alklyenepolyaminopolycarboxylic acid (APAPCA), the weight ratio of CA to APAPCA being in the range from about 0.5 to 1 to about 11 to 1 and the weight ratio of PCA to APAPCA being in the range from about 0.002 to about 0.2, wherein the polycarbazic acid has the formula (R).sub.2 --N--[CH.sub.2 CH.sub.2 N(R)].sub.m --R where R is the group CH.sub.2 --CO--NH--NH--COOH and m is 0 or an integer from 1 to about 4, and wherein the APAPCA has the formula (HOOC--CH.sub.2).sub.2 --N--[CH.sub.2 --CH.sub.2 --N(CH.sub.2 --COOH)].sub.n --CH.sub.2 COOH where n is an integer from 1 to about 4. The preferred aqueous sequestering solution has a pH in the range from about 9.5 to about 14, said pH being provided by a base selected from the group consisting of potassium hydroxide, potassium carbonate, and mixtures thereof.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile