Flame retardant polycarbonate compositions

US4753994A · kind A · utility

Assignees

• Mobay Corporation · US
• BAYER HEALTHCARE LLC · DE

Inventors

• Russell P. Carter, Jr. · New Martinsville, US
• Ulrich Grigo · New Martinsville, US
• Sivaram Krishnan · Pittsburgh, US
• Mark W. Witman · Pittsburgh, US
• Klaus Kircher · Leverkusen, DE
• Hans-Jurgen Kress · Krefeld, DE
• Wolfgang Alewelt · Krefeld, DE

Key dates

• Filing date: Dec 2, 1986
• Grant date: Jun 28, 1988
• Expiry date: Dec 2, 2006

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L69/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention is related to polycarbonate molding compositions containing a co-precipitate of a polycarbonate resin and a fluoropolymer. This co-precipitate was found to be suitable as an additive for polycarbonate resins because it offers improved dispersibility with the resin and good flammability performance as well as aesthetic characteristics. The co-precipitate is prepared by first mixing an aqueous dispersion of a fluoropolymer with a polycarbonate solution and then precipitating both using a suitable precipitation agent. After isolation washing and drying the co-precipitate of the invention is suitable for incorporation in a polycarbonate resin optionally with known flame retarding agents. Molded parts prepared from the compositions of the invention are characterized by their improved homogeneity and flame retardance.