Patents Assigned to Hoechst Aktiengelesellschaft
  • Process for preparing aromatic sulfur-containing polymers
    Patent number: 5894072
    Abstract: In a process for preparing aromatic sulfur-containing polymers, the polymer is formed from a prepolymer having halogen end groups. During preparation of the prepolymers, an alkali equivalent and a sulfur equivalent in a ratio of 0.5 to 1:1 is employed in the reaction mixture. The two-step process is particularly suitable for preparing polyphenylene sulfide.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: April 13, 1999
    Assignee: Hoechst Aktiengelesellschaft
    Inventors: Michael Haubs, Reinhard Wagener