Patents Assigned to Hoechst Aktiengessellschaft
  • Phosphoric acid polyesters and a process for their preparation
    Patent number: 5391698
    Abstract: The invention relates to phosphoric acid polyesters according to the formulae ##STR1## in which R is .dbd.CH.sub.2, .dbd.C.sub.2 H.sub.4 or .dbd.C.sub.3 H.sub.6 and m is 1 to 10 and n is 1 to 6.To prepare these phosphoric acid polyesters, the cyclic phosphoric acid ester 2,4,8,10-tetraoxa-3,9-dioxo-3,9-dihydroxy-phosphaspiro[5.5]-undecane is reacted with tris-hydroxyalkyl cyanurate or tris-hydroxyalkyl isocyanurate at temperatures of 120.degree. to 250.degree. C. in the presence of a catalyst for 2 to 12 hours, while mixing intensively.
    Type: Grant
    Filed: January 25, 1994
    Date of Patent: February 21, 1995
    Assignee: Hoechst Aktiengessellschaft
    Inventor: Horst Staendeke