| 摘要 |
Process for preparing finely divided polyacrylonitrile The invention relates to a process for preparing finely divided homopolymers or copolymers containing at least 50 % by weight of recurring acrylonitrile and/or methacrylonitrile units (based on the monomers used), which comprises: a) dissolving and/or suspending and/or emulsifying and/or dispersing the monomers in one or more liquids which are inert under the reaction conditions, where b) the sum of the monomer concentrations at the begin ning and during the polymerization is less than 10 % by weight, c) high shear forces acting on the polymerization mixture prior to and during the polymerization to that the resulting homopolymer or copolymer particles have a D50 % value of less than 10 .mu.m and d) carrying out the polymerization in a known manner by addition of a polymerization initiator. The finely divided polyacrylonitrlle is suitable, for example, as pigmenting agent and organic filler and as pigment substitute in electrophoretic surface coatings of automobile or industrial surface coatings, as matting agent and/or colorable pigment in surface coatings, plastics, fibers, films, paper and cardboard, as adsorbent for gases and liquids, as raw material for the production of carbon microbeads as filler for liquid chromatography or ion exchange columns, as reinforcing material and/or filler for polymers and as raw material for the production of fibers, films and membranes.
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