FLAME RETARDANT COMPOSITIONS

摘要

This invention relates to a flame retardant composition comprising: (a) 81 to 99.99 weight percent of a thermoplastic resin, thermoset resin, thermoplastic resin blend, or thermoset resin blend which upon burning forms a char and (b) 0.01-19 weight percent of a silsesquioxane resin having a weight average molecular weight of greater than 300 and having the average molecular formula: (R3SiO1/2)a (R2SiO2/2)b (RSiO3/2)c (SiO4/2)d(RO1/2)e (OH1/2)f wherein each R is hydrogen, an alkyl group, an alkenyl group, or an aryl group having from 6 to 12 carbon atoms, a and b are zero or positive numbers and the value of a+b is greater than zero, c is a positive number, d, e and f are zero or positive numbers with the provisos that the copolymer comprises at least 40 mole percent of RsiO3/2 units, the copolymer comprises less than 10 mole percent SiO4/2 units, greater than 30 mole percent of the silicon-bonded R groups are silicon-bonded aryl groups, greater than 0.5 mole percent of the silicon-bonded R groups are silicon-bonded hydrogen atoms, the content of silicon-bonded hydroxyl groups is equal to or less than 2 weight percent, and the content of silicon-bonded alkoxy groups where the alkoxy group is methoxy or ethoxy is equal to or less than 5 weight percent.