23.
    发明专利
    未知

    公开(公告)号:DE1219221B

    公开(公告)日:1966-06-16

    申请号:DEB0039246

    申请日:1956-02-24

    Applicant: BASF AG

    Inventor: STASTNY DR FRITZ

    28.
    发明专利
    未知

    公开(公告)号:DE1004370B

    公开(公告)日:1957-03-14

    申请号:DEB0024721

    申请日:1953-03-13

    Applicant: BASF AG

    Inventor: STASTNY DR FRITZ

    29.
    发明专利
    未知

    公开(公告)号:DE941389C

    公开(公告)日:1956-04-12

    申请号:DEB0014637

    申请日:1951-04-20

    Applicant: BASF AG

    Abstract: Porous shaped articles are produced from a polymeric resin by introducing into an enclosing mould a finely divided resin containing a volatile organic solvent having a boiling point lower than the softening point of the resin and heating to above the softening point to expand the resin and fill the mould which permits the escape of gases, but retains the resin, the solvent-containing resin being obtained by incomplete evaporation of the solvent from the solvent-resin solution. Specified resins are chlorinated polystyrene and poly-N-vinyl carbazole, preferably having a k-value of at least 30. Specified solvents are benzene, toluene, p-xylene, methylene chloride and cyclononane for the carbazole and methylene chloride, chloroform, carbon tetrafluoride and ethylene chloride for the chlorinated polystyrene. Pre-expanded particles of a solvent-containing resin may be used. The process details are the same as those described in the parent Specification.

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