| abstract |
Compounds of the general formula I wherein R₁ and R₂ independently of one another are hydrogen, C₁-C₆-alkyl, unsubstituted or substituted by 1-3 C₁-Cgruppen-alkyl groups, phenyl or naphthyl, R₃ and R₄ are independently hydrogen or C₁-C₄-alkyl, where R₃ and R₄ are not simultaneously Are hydrogen, further R₅ is hydrogen, C₁-C₆-alkyl, unsubstituted or substituted by 1-3 C₁-C₄-alkyl groups, phenyl or naphthyl and X is oxygen or sulfur, are suitable as flame retardants for polymers. |