Halogen containing fire retardant and fire retarded resin compositions containing said fire retardant

A halogen containing fire retardant represented by chemical formula (1), ##STR7## wherein the end groups X and Y are composed by A or B represented by chemical formula (2);

• and the said fire retardant comprises a mixture of the composition containing 1 to 40% of X=Y=A, the composition containing 30 to 70% of X=A and Y=B, the composition containing smaller than 70% of X=Y=B and, degree of polymerization n is n.gtoreq.0 wherein the content of n=0 is smaller than 60% to the total amount;
• wherein A and B are represented by following chemical formulae, and R of chemical formula B is an alkyl group of carbon number 1 to 8 alone, or 1 to 79% of alkyl group of carbon number 1 to 8 and 79 to 1% of tribromophenyl group, and total amount of R is smaller than 80% ##STR8##