Akzo N.v.

Gerhard Ries

Walter Fickel

Karl Ostertag

Alfons Leeb

In a method and device for shaping thread-forming materials from a homogeneous isotropic or anisotropic, single or multiphase liquid multicomponent system, the liquid multicomponent system is forced through nozzle openings into a liquid which is under pressure. The liquid is moved in the direction of travel in a channel system composed of sections with constant and/or slightly tapering cross sections, and the flow rate of the liquid is increased accordingly.

Method and device for manufacturing molded bodies

Porous, powdery polypropylene is disclosed, obtained by providing a hot solution of polypropylene in pentaerythrol ester as solvent, slowly cooling said solution down to approximately room temperature to provide a solidified mass with or without affecting mechanical size reduction of said solidified mass, and extracting said solidified mass with an extractant in which pentaerythrol is soluble, with or without subsequently removing said solvent to a high degree.

Porous, powdery polypropylene

Process for the production of porous, powdery polypropylene, and utilization thereof. Hot solutions of polypropylene in pentaerythrol ester are slowly cooled down to approximately room temperature, forming a solidified mass, after which it is extracted with an extractant in which pentaerythrol is soluble. Before extracting, the size of the solidified mass may be reduced mechanically. After extracting, the pentaerythrol may be removed from the extractant to a high degree. Preferred embodiments include using solutions of polypropylene in pentaerythrol esters of fatty acids, more specifically, of synthetic fatty acids with 8-10 carbon atoms; using ethanol for the extraction; using solutions with a weight ratio of polypropylene to pentaerythrol ester of 30:70 to 10:90; having cooling of the solutions within the range of 260.degree. to 120.degree. C. proceed at an average rate of 1.degree. to 20.degree. C. per minute; using polypropylene with an admixture of up to 10% by weight of polyethylene. The porous, powdery polypropylene is characterized by an apparent density of 0.1 to 0.3 g/cm.sup.3, a particle size of 50-700 .mu.m, and an externally accessible porosity of 70-85%. The product may be used for the separation of hydrophobic substances from aqueous systems, in particular the separation of oil; for the adsorption of liquids, in particular, as oil adsorbent; as additive to paints, particularly to protective paints; and as carrier of substances for long-term release, in particular, odorants, and more specifically, as carrier of sexual attractants for insects.

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Obernburg, Germany

Gerhard Ries