Diphosphine oxides and diphosphine sulfides as flame-retardant agents for thermoplastic products

Claim 1

A FLAME-RETARDENT COMPOSITION COMPRISING A THERMOPLASTIC POLYMER PRODUCED FROM AT LEAST ONE ETHLENICALLY UNSATURATED MONOMER AND A FLAME-RETARDING AMOUNT OF A COMPOUND HAVING THE FORMULA R-P(=X)(-R'')-Y-P(=X)(-R)-R'' WHEREIN R AND R'' ARE INDIVIDUALLY SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, AN ARYL RADICAL HAVING FROM 6 TO 10 CARBON ATOMS, INCLUSIVE, AN ALKYL RADICAL HAVING FROM 1 TO 6 CARBON ATOMS, INCLUSIVE, A CARBAMOYLALKYL FROM 7-11 CARBON ATOMS, INCLUSIVE, A CARBAMOYLALKYL RADICAL HAVING FROM 1 TO 6 CARBON ATOMS, INCLUSIVE, IN THE ALKYL GROUP, A CYANOALKYL RADICAL HAVING FROM 1 TO 6 CARBON ATOMS, INCLUSIVE, IN THE ALKYL GROUP, A CARBOXYALKYL RADICAL HAVING FROM 1 TO 6 CARBON ATOMS, INCLUSIVE, IN THE ALKYL GROUP, A HALO SUBSTITUED ARALKYL RADICAL HAVING FROM 7 TO 11 CARBON ATOMS, INCLUSIVE, AND A POLYHALO SUBSTITUTED ARALKYL RADICAL HAVING 7 TO 11 CARBON ATOMS, INCLUSIVE, Y REPRESENTS AN ALKYLENE RADICAL HAVING FROM 1 TO 4 CARBON ATOMS, INCLUSIVE, AND X IS SELECTED FROM THE GROUP CONSISTING OF OXYGEN AND SULFUR, NO MORE THAN ONE OF R AND R'' BEING HYDROGEN.