| abstract |
A process for the preparation of a linear alternating copolymer of carbon monoxide with ethene and another olefinically unsaturated compound (A) wherein a copolymer of which the molar ratio (r 1 ) of the monomer units originating in the olefinically unsaturated compound A to the monomer units originating in ethene is in the range of from 1:100 to 1:3, is prepared by contacting the monomers in the presence of a liquid diluent with a catalyst composition which is based onn (a) a source of a Group VIII metal, and (b) a bidentate ligand of the general formula R 1 R 2 M 1 -R-M 2 R 3 R 4 (I) wherein M 1 and M 2 independently represent a phosphorus, arsenic or antimony atom, R 1 , R 2 , R 3 and R 4 independently represent unsubstituted or substituted aryl groups and R represents a bivalent bridging group which consists of three atoms in the bridge of which the middle atom is a tetravalent atom which carries two monovalent substituents R 5 and R 6 consisting of carbon, hydrogen and optionally oxygen, and the two outer bridging atoms are carbon atoms, while the quotient r 2 /r 1 is less than 24, in which quotient r 1 is as defined hereinbefore and r 2 is the molar ratio of the olefinically unsaturated compound A to ethene in the liquid phase. |