Thermostable flameproofing agent for copolyesters, process for making it, copolyester compositions prepared by using it, process for making said compositions and formed bodies made from said compositions

Abstract From the Canadian patent

The invention is concerned with a thermostable flameproofing agent for copolyester compositions which comprises the, reaction product of 1 mole of a dialkyl diester of an alkali dicarboxyaryl-sulphonate having the general formula: wherein R' represents an alkyl radical containing from 1 to 3 carbon atoms and M represents an alkali metal atom with, 1 to 2 moles of at least one tetrabrominated diol having the general formula:, wherein a and b represent independently one of the other, a whole number from 1 to 3 inclusive; the reaction is effected in the presence of a transesterification catalyst selected from the group consisting of compounds of Zn Co, Ca, Sn, Ti and Mn. The flame-proofing …