Method for producing water-absorbent resins

US7179875B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Eberhard Fuchs · Bischofswerda, DE
• Hans Martan · Bischofswerda, DE
• Gerhard Nestler · Ludwigshafen, DE
• Klaus Joachim Mueller-Engel · Blankenloch, DE

Key dates

• Filing date: Aug 2, 2002
• Grant date: Feb 20, 2007
• Expiry date: Aug 2, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/487
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

In a process for preparing water-absorbent resins based on acrylic acid, crude acrylic acid is firstly isolated from the reaction gases from the catalytic gas-phase oxidation of propane, propylene and/or acrolein. This is treated with an aldehyde scavenger and pure acrylic acid is separated by distillation from the treated crude acrylic acid, and this pure acrylic acid can be subjected directly to a free-radical polymerization.