(1)-Phospha-(2,7)-dioxa-(4,5)-dibromo-cycloheptane derivs. - of bromo-phenols are used as flame retardant for fibres

摘要

Halogenated aliphatic and aromatic phosphate ester (I) used as flame retardant component for fibres is the reaction prod. of POCl3, 2,3-dibromobutan-1, 4-diol (II) and bromophenols (III), pref. tribromophenol (IIIa), chlorobromophenol or pentabromophenol. 1-Phospha-2,7-dioxa-4,5-dibromo-cycloheptane derivs. (Ia) of brominated phenols of the formula: C6HxHal5-xOH (in which Hal is Cl or Br, at least one Hal being Br, and x = 0-4) are claimed as new cpds. (I) are stable enough to withstand incorporation in spinning melts for synthetic fibres, pref. polyolefins, esp. polypropylene, and the spinning process, without damage, and are completely effective without the synergistic action of Sb2O3 in the fibre. (I) is pref. added to the spinning melt in an amt. of 1-20 20 pts. wt./100 pts. fibre material. In an example, a polypropylene sample contg. 15% reaction prod. (Ib) of POCl3, (II) and (IIIa) or reaction prod. (IV) of POCl3, dibromopentaerythritol and (IIIa), the extinguishing time and burnt length of samples were 19 s and 32 mm. with (lb). cf. 24 s. and 34 mm. with (IV).