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. 04, 1997
Filed:
Jul. 18, 1996
Rudiger Funk, Niedernhausen, DE;
Fritz Engelhardt, Frankfurt am Main, DE;
Ulrich Riegel, Frankfurt am Main, DE;
Michael Wessling, Maintal, DE;
Cassella, , DE;
Abstract
Method for avoiding network defects due to unwanted secondary reactions during the polymerization in water-swellable hydrophilic polymers which contain polymers prepared by free radical (co)polymerization of one or more hydrophilic monomers of the formula I ##STR1## wherein R.sup.1 is hydrogen, methyl or ethyl, R.sup.2 is the group --COOR.sup.4, the sulphonyl group, the phosphonyl group, the phosphonyl group-esterified by (C.sub.1 -C.sub.4)-alkanol or a group of the formula ##STR2## R.sup.3 is hydrogen, methyl, ethyl or the carboxyl group, R.sup.4 is hydrogen, amino or hydroxy-(C.sub.1 -C.sub.4)-alkyl and R.sup.5 is the sulphonyl group, the phosphonyl group or the carboxyl group, or grafting (co)polymerization of one or more hydrophilic monomers of the formula I onto a grafting base, using a free radical initiator which forms three or more free radical sites per molecule.