Bayer Aktiengesellschaft

Original Hanau Heraeus Gmbh

Helmut Schmid

Dieter Freitag

Rolf Dhein

Dieter Margotte

Erich Eimers

Werner Kloker

Ulrich R Grigo

Walter Uerdingen

Helmut Steinberger

Manfred Schonfelder

Joachim Wagner

Wolfgang Nising

Siegfried Anders

Bernhard Hess

Wolfgang Wehnert

Hans G Fitzky

Gunther Kampf

Hartmut Lower

Hans-Werner Depcik

Josef Dullings

Martin Bock

Ulrich Schutz

Helmut Winchenbach

Holger Lusgen

The present invention relates to UV-protected, multilayer polycarbonate sheets containing a base sheet, at least one outer layer and optionally at least one additional protective layer, and to the production of the polycarbonate sheets according to the invention by coextrusion.

UV-protected, multilayer polycarbonate sheets

Reaction compositions of selected make-up result after curing in non-meltable polymers of high mechanical stability and low water uptake. Owing to the low birefringence of the cured products, these compositions are highly suitable for preparing carrier materials for optically and magnetically readable and/or writable data carriers.

Curable reaction compositions for producing data carriers

A pacified mass is hardened under controlled conditions to produce low tension moulded parts (4) of duroplasts, the shringkage being compensated for by the movement of a lower mould part (2) and/or an upper mould part (3) to follow the mass.

Apparatus for the production of low tension moulded parts

A mass is cooled systematically under the influence of an electrical or mechanical alternating field to obtain a quasi dielectric isotropic structure of a synthetic resin part.

Synthetic resin parts with quasi dielectric isotropic structure

The present invention relates to thermoplastic mixtures of 90 to 20% by weight of an aromatic polycarbonate with an Mw of 15,000 to 25,000 and p-(iso-C.sub.8 -C.sub.9 -alkyl)-phenyl end groups and 10 to 80% by weight of a polystyrene with an Mw of 80,000 to 400,000, and to their use as substrates for optical data memories.

Thermoplastic mixtures of aromatic polycarbonates and polystyrenes and

The invention relates to plastics mouldings, more particularly transparent plastics mouldings, which are finished with a coating of three successively stoved, chemically different layers, and to a process for producing the finish. The special finish considerably improves the scratch resistance, abrasion resistance, weathering resistance and yellowing resistance of the plastics surfaces without affecting the transparency of the plastics moulding. The first layer (primer layer) is produced from a hardenable acrylic resin and an aminoplast resin, the second layer from a thermoplastic acrylic resin, a plasticizer and a masked polyisocyanate and the third layer (cover layer) from at least one partially hydrolyzed organosilane, an .alpha.,.omega.-dihydroxy polydimethyl siloxane, a silica sol and at least one masked polyisocyanate as binder in the presence of a water-soluble organic or inorganic acid. The three-layer coating contains UV-absorbers, light stabilizers and, optionally, standard auxiliaries.

Plastics mouldings finished with a three-layer coating and a process for

To provide for more reliable determination of resistance of sample surfaces to light and weather influences, test apparatus is equipped with a radiation-measuring device. A portion of radiation used for testing is guided to the measuring device, by quartz guides, spectrally dispersed, and measured as to intensity and/or dosage in one or several pre-selected spectral regions. Tests may use natural or artificial radiation, and a measuring device may be stationary or movable relative to a radiation source.

Test apparatus for determining resistance to light and weather influences

Phosphites of the general formula: ##STR1## in which n.sub.1 is an integer;

Esters of phosphorous acid

Phosphites of the general formula: ##STR1## in which N.sub.1 IS AN INTEGER;

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Krefeld, Germany

Helmut Schmid