Water-absorbing polymer particles with high free swell rate and high permeability

US9738769B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Matthias Weismantel · Bad Orb, DE
• Ulrich Riegel · Landstuhl, DE
• Thomas Gieger · Ludwigshafen, DE
• Markus Braun · Mannheim, DE
• Michael A. Mitchell · Fort Mill, US

Key dates

• Filing date: Feb 8, 2013
• Grant date: Aug 22, 2017
• Expiry date: Jul 30, 2034

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2333/14
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A process for producing water-absorbing polymer particles with high free swell rate and high permeability by polymerization of an aqueous monomer solution or suspension to give an aqueous polymer gel, wherein a thermal blowing agent essentially free of inorganic acid anions is mixed into the polymer gel, and subsequent thermal drying of the polymer gel.