GB1100605A - Improvements in or relating to polyester materials - Google Patents

Abstract

A polyester material contains as fire retardant a compound Ar(Br)m(Cl)nR or Ar(Br)m(Cl)nOR, where Ar is an aryl residue, m is 1 or more, n is 0, 1 or 2 and R is H or an alkyl, alkenyl, aryl or aralkyl group which may be halogenated, the compound containing at least two nuclear Br atoms per molecule, and providing at least 1.5 wt. per cent Br in the polyester resin. Suitable polyesters include commercial terephthalate polyesters and solution of glycol phthalate maleate in styrene. Suitable aromatic bromine compounds are tribromophenol, tetrabromo -, pentabromo -, pentabromo - ethoxy -, pentabromo - propoxy -, pentabromo - allyloxy-, and chloro-dibromo-allyloxy-benzene, and tribromo-, pentabromo-, tribromo-allyloxy-, and chloro - dibromo - toluene, and hexabromo - diphenyl ether, dibromo-diphenyl, dibromonaphthalene, 2:4 - dibromo - 1 - methyl - naphthalene and 1:5-dibromo-anthracene. The preferred Br content of the resin is 10-15 wt. per cent. There is preferably also incorporated in the polyester Sb2O3 amounting at least to 1 p.b.w. per 8 p.b.w. of bromo compound, preferably 0.5-1.5 p.b.w., per p.b.w. In examples various unsaturated polyester-styrene resins are mixed with a bromo-compound, benzoyl or MEK peroxide, and optionally also a Co naphthenate accelerator, CaCO3 filler and Sb2O3 and trixylyl phosphate as synergistic fire-retarding agents. A saturated polyester is mixed with pentabromotoluene and Sb2O3 (Example 10). The unsaturated resins are made into panels with or without glass fibre reinforcement. The bromo compounds used are tribromophenol, tribromotoluene, tribromophenyl allyl ether, pentabromophenyl allyl ether, pentabromophenol, pentabromotoluene, tetrabromobenzene and 4-chloro-tetrabromophenol.