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. 12, 1984
Filed:
Apr. 05, 1982
Applicant:
Inventor:
Friedl Heger, Linz, AT;
Assignee:
Chemie Linz Aktiengesellschaft, Linz, AT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08K / ;
U.S. Cl.
CPC ...
524211 ; 524767 ;
Abstract
An improved process for substantially increasing the shelf-life of aqueous solutions of melamine-formaldehyde resins wherein the molar ratio of melamine to formaldehyde is from 1:1.7 to 1:3.5 by the addition of a stabilizing amount of urea after condensation, which process includes the steps of adjusting pH of the resin solution before and after the dissolution of the urea within certain narrow but easily controllable pH ranges. The properties of the resin solution can be further improved and the stabilizing effect of the addition of urea increased by adding a monohydric C.sub.1 -C.sub.4 alkanol during condensation of the resin.