Patents Assigned to Ronm GmbH
  • Method for making 9,9-bis-(4-hydroxyphenyl)-fluorene
    Patent number: 4675458
    Abstract: A method for making 9,9-bis-(4-hydroxyphenyl)-fluorene by reacting fluorenone with phenol at a temperature from 20.degree. to 100.degree. C. in the presence of sulfuric acid of a concentration higher than 70 percent and of a mercaptan, and particularly beta-mercaptopropionic acid, as acidic condensing agents.
    Type: Grant
    Filed: October 3, 1985
    Date of Patent: June 23, 1987
    Assignee: Ronm GmbH
    Inventors: Achim Riemann, Werner Ude