TERTIARY PHOSPHINE OXIDES AND PROCESS FOR THEIR PREPARATION

摘要

1451909 Tertiary phosphine oxides HOECHST AG 28 Nov 1973 [30 Nov 1972] 55218/73 Heading C2P The invention comprises phosphine oxides of the general formula wherein R 1 and R 2 each represents an alkyl group having from 1 to 6 carbon atoms, and R 3 represents a phenyl group which is unsubstituted or substituted by 1 to 5 of the same or different substituents selected from chlorine and bromine atoms, or represents the group in which each of the phenylene radicals A and B is unsubstituted or substituted by from one to four of the same or different substituents selected from chlorine and bromine atoms, R 1 1 and R 2 1, which may be the same or different, each represents an alkyl group having from 1 to 6 carbon atoms, R 4 and R 5 , which may be the same or different, each represents a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and n and n1, which may be the same or different are each 1, 2 or 3. They may be obtained by reacting a haloalkyl compound wherein Hal is halogen, e.g. Cl or Br, with a salt, (e.g. an alkali or alkaline earth metal salt of the appropriate phenol or bisphenol. If desired, the salt may be formed in situ by adding an alkali- or alkaline earth metal oxide, hydroxide, or carbonate to the reaction mixture of the halogenoalkyl phosphine oxide and the phenol. An inert solvent is preferably used as reaction medium and such solvent may be the reaction product itself. The products are useful as flame-retardant agents, e.g. in the preparation of linear polyesters and may be added during or after the polycondensation.