Process for making crosslinked polyvinylpyrrolidone

US6660800B1 · kind B1 · utility

Assignee

• Arco Chemical Technology, L.P. · US

Inventors

• Beth M. Steinmetz · Via Enrico Fermi, US
• Manish K. Nandi · Wayne, US

Key dates

• Filing date: Oct 17, 2002
• Grant date: Dec 9, 2003
• Expiry date: Dec 22, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F8/44
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for making crosslinked polyvinylpyrrolidone (PVP-P) is disclosed. Crosslinker generation, followed by polymerization of NVP, gives a polymer containing up to 4 wt. % of residual NVP. An aqueous mixture of the polymer is then heated in the presence of a protic acid at pH<4 to eliminate NVP. Finally, the PVP-P is neutralized with aqueous alkali metal hydroxide. The process generates a reduced volume of low-toxicity aqueous waste (<20 L/kg PVP-P) and gives PVP-P that meets important product specifications.