Polyoxymethylene molding materials having improved thermal stability, their preparation and their use

US4837400A · kind A · utility

Assignee

• BASF SE

Inventors

• Manfred Walter · Nuremberg, DE
• Wilhelm Schuette · Speyer, DE
• Heiner Goerrissen · Ludwigshafen, DE

Key dates

• Filing date: Feb 4, 1988
• Grant date: Jun 6, 1989
• Expiry date: Feb 4, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08K13/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Polyoxymethylene molding materials having improved heat stability and consisting of PA1 (A) one or more polyoxymethylene homopolymers and/or copolymers and PA1 (B) one or more antioxidants having a sterically hindered phenolic structure, PA1 (C) with or without additives, contain PA1 (D) as an additive, one or more alkaline earth metal silicates and/or alkaline earth metal glycerophosphates, advantageously in an amount of from 0.002 to 2.0% by weight, based on the weight of component (A), for improving the heat stability, reducing the tendency to discoloration and minimizing the free formaldehyde content. To prepare the novel polyoxymethylene molding materials, the components are advantageously melted in an extruder at from 150.degree. to 260.degree. C. The polyoxymethylene molding materials are useful for the production of films or, preferably, moldings, which are used, for example, in the automotive, electrical appliances and electronics industries.