Patents Assigned to National Research Council of Canada/Conseil de Recherches Canada
  • Patent number: 4999415
    Abstract: This invention relates to aromatic polysulfone compounds and their manufacture. More particularly, this invention relates to functional group containing aromatic polysulfones, and their manufacture by metalation with organo-lithium compounds, of halogenated (e.g. brominated or chloromethylated) aromatic polysulfone compounds. The degree of halogenation of the starting material determines the sites that may be metalated, and the degree of metalation determines how many of these sites will be metalated. At least one of the metalated sites may be treated with an electrophile so that the lithium at that site is replaced by a residuum of the electrophile.
    Type: Grant
    Filed: December 7, 1988
    Date of Patent: March 12, 1991
    Assignee: National Research Council of Canada/Conseil de Recherches Canada
    Inventors: Michael D. Guiver, Oleh Kutowy
  • Patent number: 4996271
    Abstract: Halogenation of Udel (trademark) and Radel (trademark) polysulfone occurs adily by electrophilic substitution. The reactive substitution position is situated ortho- to the aryl ether linkage in the Bisphenol-A portion of the repeat units. Halogenated polysulfones are obtained by reaction of the polymer with elemental halogen. Thus, a solution of Udel polysulfone in chloroform, treated with excess bromine at room temperature, gives dibrominated polysulfone III in high yield. The degree of substitution after 18-24 hours is typically 1.80 to 2.05 by bromine analysis. Similar results are obtained by reaction of the polymer with elemental chlorine. Lower degrees of substitution are obtained with shorter reaction times or using lesser amounts of halogen.
    Type: Grant
    Filed: December 7, 1988
    Date of Patent: February 26, 1991
    Assignee: National Research Council of Canada/Conseil de Recherches Canada
    Inventors: Michael D. Guiver, Oleh Kutowy