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:
Jan. 06, 1997
Filed:
Jan. 18, 1995
Richard J Riehle, Wilmington, DE (US);
Ronald R Staib, Wilmington, DE (US);
Hercules Incorporated, Wilmington, DE (US);
Abstract
The invention provides a novel poly(aminoamideureylene) resin and a process for making the resin without epichlorohydrin. The resin useful for improving wet strength of paper and paperboard intermediates. The resin is formed by making a prepolymer by reacting a diaminoamine, a dicarboxylic acid, and urea, allylating the prepolymer, and then reacting with hypohalous acid to produce an allylated quaternized poly(aminoamideureylene) having halohydrin substituents with resort to using epichlorohydrin. The resin can be activated for use in a papermaking process by treatment with a caustic (alkaline) agent. Optionally, the resin can be cross-linked prior to activation by heating in the presence of a caustic agent. The invention also provides an improvement in making polymers having halohydrin substituents formed by reacting an allylated polymer with hypohalous acid wherein the reaction is conducted without control of the pH. This invention also provides a method for producing hypohalous acid by acidifying an aqueous solution of an alkali metal hypohalite.