摘要 |
Copolycondensation products of beta -haloalkyl phosphates and dialkyl phosphonates are useful fire retardant agents. The products are prepared by heating the starting materials at a temperature of about 110 DEG to 250 DEG C., preferably in the presence of a nucleophilic catalyst, until at least one mole of alkyl halide per mole of phosphonate is driven off. Preferred are copolycondensation products obtained by substantially complete removal of halogen as alkyl halide.
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