Basf Aktiengesellschaft

Evonik Rohmax Additives Gmbh

Axel Mueller

Michael Mueller

Boris Eisenberg

Bardo Schmitt

Horst Weiss

Torsten Stoehr

Christof Mehler

Susanne Steiger

Stephan Jungling

Helmut Schlaad

Harald Becker

(EN) The invention relates to a polymer comprising 50-100% by weight, with regard to the weight of the polymers, of repeating units, which are derived from one or more ethylenically unsaturated ester compounds of formula (I), in which R represents hydrogen or methyl; Rrepresents a linear or unbranched alkyl radical with 7 to 30 carbon atoms, and; Rand Rindependently represent hydrogen or a group of formula &#x2014;COOR', wherein R&#x2032; represents hydrogen or an alkyl group with 7 to 30 carbon atoms. The polymer is a star polymer with 3 to 21 arms and at least 3 of the arms consist of at least 40% by weight, with regard to the weight of the arms, of repeating units, which are derived from one or more ethylenically unsaturated ester compounds of formula (I), in which Rrepresents a linear or unbranched alkyl radical with 7 to 30 carbon atoms, and; Rand Rindependently represent hydrogen or a group of formula &#x2014;COOR&#x2032;, wherein R&#x2032; represents hydrogen or an alkyl group with 7 to 30 carbon atoms. The invention also relates to oil formulations comprising the inventive polymers. The inventive polymers having a high thickening action can be used, in particular, as viscosity modifiers, pour point depressants, dispersing agents and/or friction modifiers.

Oil soluble polymers

Polyacrylates based on alkyl acrylates or alkyl alkylacrylates or mixtures thereof as monomers are prepared in the presence of an initiator composition containing an alkali metal ester enolate and an organic aluminum compound or a mixture thereof, by a process in which an ester which differs from the monomers is present in the initiator composition, the carbon atom .alpha. to the ester group having no acidic proton.

Preparation of polyacrylates

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Wiesbaden, Germany

Axel Mueller