Bayer Materialscience Ag

Bayer Aktiengesellschaft

Melanie Möthrath

Helmut-Werner Heuer

Thomas König

Uwe Hucks

Wolfgang Nising

Siegfried Anders

Rüdiger Gorny

Marc Buts

Lydia Simon

Rolf Wehrmann

Wolfgang Ebert

Alexander Meyer

Johan Vanden Eynde

Klemens Kohlgrüber

Robert Maleika

Michael Erkelenz

Jörg Kirchhoff

James P Mason

Lothar Bunzel

Martin Döbler

Thomas Pfingst

Steffen Kühling

Dirk Van Meirvenne

Heidemarie Pantke

Peter Snobl

A multilayer product characterized by its improved weatherability and mechanical properties is disclosed. The product contains a layer A containing a member selected from the group consisting of transparent thermoplastic material and a lacquer, the member containing at least one UV absorber, a layer B containing a transparent thermoplastic material and containing at least one colorant, and a layer C containing a transparent thermoplastic material. Also disclosed is a process for the preparation of the inventive multilayer product.

Multi-layer weather-resistant, coloured panel

An optical data storage comprising a thermoplastic copolycarbonate is disclosed. The copolycarbonate contains at least one unit derived from dihydroxydiphenyl ether and at least one unit derived from at least one member selected from the group consisting of 4,4'dihydroxybiphenyl and 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.

Copolycarbonates having improved flowability

A multi stage process for the production of polycarbonates having low monomer content is disclosed. The process entails, in sequence, (i) transesterifying in the melt at least one dihydroxyaryl compound with at least one diaryl carbonate in the presence of at least one onium catalyst to produce a polycondensate that contains monomers, (ii) introducing into the polycondensate an inhibitor in an hypostoichiometric amount in relation to the catalyst and (iii) reducing in a finishing reactor the content of monomers in said polycondensate. The polycarbonate thus produced is characterized in that it contains less than 350 ppm of diphenyl carbonate, less than 40 ppm of 2,2-bis-(4-hydroxyphenyl)propane and less than 150 ppm of phenol.

Transesterification process for the production of polycarbonates having a low content of volatile compounds

An improvement to the melt transesterification process for the preparation of polycarbonate is disclosed. The improvement entails adding to the process between its medium viscosity reactor and a high viscosity reactor at least one bridged ester of organic sulphur-containing acid.

Inhibition of catalytically active impurities in polycarbonate by the melt transesterification process

The invention describes a process for the preparation of polycarbonate. The process includes

Process for the preparation of polycarbonate

A process for stripping volatile constituents from polymer melts is disclosed. The process entails introducing the polymer melt into a horizontally oriented cylindrical device that contains a plurality of perforated disks rotating about a common horizontally oriented, externally driven shaft bringing the melt and disks into contact in a manner calculated to constantly renew the surface of the melt to be stripped. Also disclosed is an apparatus suitable for the process.

Process for stripping monomers and other volatile constituents from polymer melts

A thermoplastic molding composition comprising polycarbonate and 50 ppm to 300 ppm, in relation to the weight of the composition, of diphenyl carbonate is disclosed. The composition is especially suitable for the preparation of extruded sheets, in particular coextruded.

Polycarbonate containing diphenyl carbonate and sheets made therefrom

Growing community of inventors

Düsseldorf, Germany

Melanie Möthrath