Shell Oil Comapny

Shell Development Company

Jan W De Beukelaar

Jacob B Roest

Ross T Channon

Henry Van Zwet

Abraham Van Mannekes

This invention is directed to an improved method for the work-up of the reaction product from stereospecific polymerization of propylene with Ziegler Type catalysts in a liquid phase polymerization process employing a C.sub.3 reaction medium. The product work-up comprises treatment of the reactor effluent slurry with a small amount of a C.sub.3 or C.sub.4 alkanol and with oxygen or an effective peroxide, followed by washing of the polymer with a C.sub.3 hydrocarbon medium containing a small amount of a C.sub.3 or C.sub.4 alkanol.

Purification of propylene polymerization product

In conventional olefin polymerization using TiCl.sub.3 -containing Ziegler type catalysts, the catalyst-containing reaction product may be de-ashed by treatment with titanium-solubilizing compounds such as alcohols and the polymer product from the de-ashing step washed with a hydrocarbon to separate it from catalyst residue. It is desirable to treat the dirty hydrocarbon wash liquid to recover purified hydrocarbon suitable for recycle to the polymerization reaction. According to this invention the dirty hydrocarbon wash liquid is treated with an epoxy compound in the presence of an alcohol and distilled to recover purified hydrocarbon suitable for recycle.

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Amsterdam, Netherlands

Jan W De Beukelaar