Abstract: The invention relates to a process for producing viscoelastic polyurethane foams by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups in the presence of c) catalysts, d) blowing agents, wherein ai) diphenylmethane diisocyanate or aii) mixtures of diphenylmethane diisocyanate and polymethylenepolyphenylene polyisocyanates and/or aiii) prepolymers which comprise isocyanate groups and can be prepared by reacting aiv) polyether alcohols with diphenylmethane diisocyanate or mixtures of diphenylmethane diisocyanate and polymethylenepolyphenylene polyisocyanates are used as a) polyisocyanates and mixtures of at least one catalyst ci) and at least one catalyst cii) are used as catalysts.

Abstract: The invention relates to the use of nitrogenous aluminium organyl complexes of general formula (I) as co-catalysts in heterogeneous polymerisation reactions of propene. In said formula: R, R?, R1 and R1? independently of one another represent branched or unbranched C1-C7 alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl or alkynyl; R2 represents unsubstituted, monoalkylated or polyalkylated and/or monofluorinated or polyfluorinated aromatic hydrocarbons from group (II); R3 and R4 independently of one another represent CH2, CF2 oder C(R1)2; m stands for 0, 1 or 2; n stands for 0, 1 or 2; o stands for 0 or 1, all independently of one another.

Abstract: Disclosed are compounds of formula (I) which compounds are useful as cocatalysts in olefinic polymerisation reactions, e.g., as Ziegler-Natta catalysts.

Abstract: The present invention relates to novel oxygen-containing organoaluminium complexes of the general formula (I) in which R1, independently of one another, denote branched or unbranched C1-C7-alkyl, -cycloalkyl, -alkenyl, -cycloalkenyl, -aryl or -alkynyl; R2 denotes unsubstituted, mono- or polyalkylated and/or mono- or polyfluorinated aromatic hydrocarbons from the group R3, R4, independently of one another, denote CH2, CF2 or C(R1)2; independently of one another, m denotes 0, 1, 2 n denotes 0, 1, 2. These compounds can serve as cocatalysts in olefinic polymerisation reactions. In particular, they can be employed for the preparation of novel Ziegler-Natta catalysts having improved properties, in particular having higher activities compared with conventional Ziegler-Natta catalysts with AlEt3, as cocatalyst, or of novel coordination catalyst systems which have higher activities than conventional Ziegler-Natta catalysts, even at low temperatures, such as 60° C., and a pressure of 2 bar.

Abstract: The invention relates to the use of nitrogenous aluminium organyl complexes of general formula (I) as co-catalysts in heterogeneous polymerisation reactions of propene. In said formula: R, R′, R1 and R1′ independently of one another represent branched or unbranched C1-C7 alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl or alkynyl; R2 represents unsubstituted, monoalkylated or polyalkylated and/or monofluorinated or polyfluorinated aromatic hydrocarbons from group (II); R3 and R4 independently of one another represent CH2, CF2 oder C(R1)2; m stands for 0, 1 or 2; n stands for 0, 1 or 2; o stands for 0 or 1, all independently of one another. Said systems exhibit improved characteristics in terms of activity and stereoselectivity in comparison to conventional co-catalysts such as AlEt3 and can act simultaneously as co-catalysts and stereoselectivity promoters.