Abstract: The synthesis of a non-halogen flame retardant oligomer containing highly pendnat phosphorus moieties is disclosed. Diols, unsaturated double bond-containing dicarboxylic acids or acid anhydrides and saturated dicarboxylic acids or acid anhydrides are first esterified to form an oligomeric unsaturated polyester, and then a phsophorus-containing compound is grafted onto the oligomeric unsaturated polyester through addtion reaction in the presence of a selected metal complex catalyst.

Abstract: A process for preparing a flame-retardant phosphorus-containing unsaturated polyester resin blend, comprising the following steps:(a) reacting(1) a phosphorus-containing monomer having the formula: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are respectively H, C.sub.1 -C.sub.4 alkyl, phenyl, alkaryl or aralkyl, with(2) a saturated dicarboxylic acid, or a saturated dicarboxylic acid anhydride,(3) a double bond-containing unsaturated dicarboxylic acid or a double bond-containing unsaturated dicarboxylic acid anhydride, and(4) a diolin the presence of a metal catalyst combined with an acid to form an unsaturated polyester oligomer having the formula: ##STR2## wherein R.sub.5 and R.sub.6 are respectively C.sub.1 -C.sub.4 alkylene, alkarylene, phenylene or aralkylene,R.sub.4 is a vinyl-containing group,x is an integer of 1-10,y is an integer of 1-10,z is an integer of 1-10, and(b) blending said unsaturated polyester oligomer with a vinyl-containing monomer.

Abstract: A heat resistant phosphorus-containing polymeric flame retardant and a process for preparing the same are disclosed. The process is characterized in that in polycondensation a selected metal salt serving as cocatalyst is used to catalyze a phosphorus-containing compound, a saturated dicarboxylic acid or the derivatives thereof, and a diol to form a high phosphorus content, high molecular weight flame retardant. The selected metal salts can promote the polymerization of phosphorus-containing compounds and polyester, and can inhibit side reactions and depolymerization so as to increase the phosphorus content of the resulting products and reduce the manufacturing cost. The flame retardants thus prepared can endure processing at an elevated temperature and thus are suitable for being applied in flame retardant fibers, fabrics, nonwoven fabrics, adhesives, and plastics.