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:
Feb. 12, 1985
Filed:
Sep. 24, 1982
Friedrich Engelhardt, Frankfurt, DE;
Steffen Piesch, Oberursel, DE;
Juliane Balzar, Frankfurt, DE;
Jeffery C Dawson, Katy, TX (US);
Cassella Aktiengesellschaft, Frankfurt am Main, DE;
Dresser Industries, Inc., Dallas, TX (US);
Abstract
The present invention relates to macromolecular compositions crosslinked by a novel bridge having the formula --NR.sup.x --CH.dbd.N--CO--. This novel bridge is obtained by reacting a macro-molecule, preferably a polymer, having at least two amidocarbonyl groups with a compound having at least two formylamido groups in an aqueous medium under highly acidic conditions. The crosslinking bridge formed by the reaction of this invention is produced in accord with the following formula: ##STR1## Compositions containing macromolecules having at least two amidocarbonyl groups and a compound having at least two formylamido groups can act as viscosifying or gelling agents for aqueous acids where when added to aqueous acids, crosslinking occurs. Acids gelled in this manner have important use in the recovery of oil and natural gas from subterranean formations.