Color-stable, weather-, and impact-resistant molding compositions based on polymethylmethacrylate, and process for production thereof

US5726245A · kind A · utility

Assignee

• Roehm GmbH Chemische Fabrik · DE

Inventors

• Uwe Numrich · Weiterstadt, DE
• Michael Wicker · Seeheim-Jugenheim, DE
• Thomas Rhein · Stadecken-Elsheim, DE
• Thomas Suefke · Langen (Hessen), DE

Key dates

• Filing date: Nov 27, 1996
• Grant date: Mar 10, 1998
• Expiry date: Nov 27, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S525/932
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Highly transparent, impact-resistant molding compositions based on polymethyl methacrylate (PMMA), having excellent color stability both during processing at high temperatures, as well as when under thermal stress, as a result of multiple processing with simultaneously high weathering stability and stability of the optical characteristics with the effect of water. Preparation is carried out according to a multi-step extruder process, wherein an extruder for the melt coagulation and one for the compounding are connected in series. Addition of small quantities of reducing inorganic phosphorous compounds at a later stage provides prolonged effectiveness.