Patents Examined by Salim Bared
  • Compositions and methods for inhibiting vinyl aromatic monomer polymerization
    Patent number: 5426257
    Abstract: Compositions and methods for inhibiting polymerization of vinyl aromatic monomers in oxygen-free processing systems are disclosed. The compositions comprise an oxime compound and a hydroxylamine compound and, alternatively, an oxime compound, a hydroxylamine compound and a phenylenediamine compound. The methods comprise adding either of the compositions to the vinyl aromatic monomer in an amount ranging from 1 to about 10,000 parts per million parts monomer.
    Type: Grant
    Filed: June 3, 1994
    Date of Patent: June 20, 1995
    Assignee: Betz Laboratories, Inc.
    Inventor: Graciela B. Arhancet