| 摘要 |
Low flammability linear polyesters are made incorporating 2-30 wt. % of a Br contg. phosphonate (I) into the polyester during or after its mfr. In the formula, R1 is a 1-6C divalent hydrocarbon gp., -SO2-, -OCOO-, -CO-, or -O-; R2 is a 2-8C divalent hydrocarbon gp.; R3 is an opt. halogenated 1-4C alkyl gp.; m is 1-10 and n = 1-50. A pref. cpd. (I) is a polyphenylphosphonate of 2,2-bis 4-(2-hydroxyethoxy)-3,5-dibromophenyl propane (II) in which R1 is -C(CH3)2-, R2 is -CH2-CH2-R3 is phenyl, m=1 and n is pref. >10.Incorporation of (I) into polyesters such as polyethylene terephthalate gives prods. with good flame resistance coupled with good whiteness and resistance to heat and hydrolysis. The prods. are useful for the prodn. of mouldings, films and esp. fibres. The latter are useful in the prodn. of flame retardant textile fabrics.
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