Color-stable superabsorber

US8815770B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Mark Elliott · Ludwigshafen, DE
• Thomas Daniel · Waldsee, DE
• Norbert Herfert · Charlotte, US

Key dates

• Filing date: Sep 14, 2010
• Grant date: Aug 26, 2014
• Expiry date: Sep 14, 2030

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08K5/005
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A superabsorbent produced by polymerizing a monomer mixture which comprises at least one ethylenically unsaturated monomer bearing at least one acid group, at least 0.1% by weight and at most 20% by weight, based on the total amount of ethylenically unsaturated monomers bearing at least one acid group (calculated as the free acid), of at least one alkaline earth metal salt (calculated without water of crystallization) selected from the salts of calcium, strontium or barium having been added before or during the polymerization and/or, if the polymerization is followed by a separate drying step, to the polymer before the drying, exhibits improved stability to discoloration in the course of storage under elevated temperatures and/or elevated air humidity.