Bayer Aktiengesellschaft

Karl-Heinz Aleksander Ostoja-Starzewski

Josef Witte

Herbert Bartl

Karl-Heinz Reichert

Georgios Vasiliou

Uwe Claussen

Warren Mark Kelly

Peter Schertl

Bruce S Xin

The present invention relates to compounds in which a transition metal is complexed with two ligand systems and the two systems are reversibly bonded together by at least one bridge consisting of a donor and an acceptor, at least one substituent on the acceptor group being a fluorinated aryl radical, to the use of these compounds as catalysts and to a process for the polymerization of olefins.

Catalysts with a donor-acceptor interaction

The invention relates to novel &pgr;-complex compounds of transitional metals. The novel &pgr;-complex compounds are suitable for use as catalysts for the (co)polymerization of olefins, cyclo-olefins, alkynes, diolefins, vinyl ester and vinyl aromatics.

&pgr;-complex compounds

Supported catalysts with a donor-acceptor interaction

Branched low-pressure polyethylenes are prepared by oligomerization of ethylene on a nickel-containing catalyst and polymerization of the oligomers obtained, if appropriate in the presence of ethylene, on a chromium-containing catalyst.

Process for the preparation of branched low-pressure polyethylene, new

Highly effective polarizers are described having a degree of polarization P of at least 95% and a dichroic ratio Q.sub.E =quotient of the extinction in the blocked position to the extinction in the transmission position, over almost the entire wavelength range of visible light, between 400 and 800 nm, of 10 or greater, the said polarizers comprising polyacetylene-containing polymer products with a matrix of pure polyvinyl alcohol (PVA). They are used in the form of films with a stretch ratio ##EQU1## (1=length after stretching, 1.sub.0 =length prior to stretching) of more than 300%. They can be prepared by polymerizing acetylene in a solution of pure PVA in the presence of a nickel catalyst.

Highly effective polarizers

New light-polarizing articles (preferably in film form) are based on a polymer matrix which polarizers based on a polymer matrix which is constructed from polar or nonpolar monomer units or mixtures thereof, characterized in that polyacetylene is included as light-polarizing substance, said polyacetylene being obtained by polymerizing acetylene in solutions of said polymer matrix and thereafter processing the resultant polyacetylene/polymer solutions into polarizers.

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Bad Vilbel, Germany

Karl-Heinz Aleksander Ostoja-Starzewski