Abstract: A lubricating system composition for the extrusion of polyvinyl chloride resin conduits is provided by treating silica fume particles at least in part with a lubricant to form a premix additive for polyvinyl chloride extrusion compounds whereby the resulting product has unique and particularly advantageous physical characteristics which makes possible the reduction in wall thickness and an increase in loading of calcium carbonate to effect a material reduction in cost of manufacture.

Abstract: Titanium trichloride for use as a component of a Ziegler polymerization catalyst is modified in order to enhance the activity and/or stereospecificity of the catalyst in the polymerization of olefins, especially propylene, by heating the titanium trichloride with phosphorus oxytrichloride in an aromatic hydrocarbon diluent for several hours in the absence of the organo aluminium component of the catalyst. Ball milling, or shearing, during the modification reaction is not required. The use of aromatic hydrocarbon gives unexpected improvement compared with any other hydrocarbon diluent and the modification reaction gives improved results compared with addition of the titanium trichloride, phosphorus oxytrichloride and the organo aluminium component to the reactor at the beginning of a batch polymerization.