Flame resistant, low pilling polyester fiber

A flame resistant, low pilling polyester comprising the blended product of the following two polymers

• a) a first polymer being the reaction product of dimethyl terephthalate, ethylene glycol and tetraethyl ortho silicate;
• and
• b) a second polymer being the reaction product of dimethyl terephthalate, ethylene glycol and 2-carboxyethyl methyl phosphinic acid.

A method of making a flame resistant, low pilling polyester which comprises the blended product of the following two products:

• a) a first polymer being the reaction product of a dicarboxylic acid or a lower alkyl ester thereof, a diol and an oxysilicon compound;
• and
• b) a second polymer being the reaction product of a dicarboxylic acid or a lower alkyl ester thereof, a diol and a carboxyphosphinic acid monomer, said monomer being used in an amount of from 0.5 to 20 mole percent based on the total amount of dicarboxylic acid or lower alkyl ester thereof and monomer, said monomer of the general formula ##STR7## or a lower alkyl ester or cyclic anhydride of said monomer wherein R is a saturated, open-chain or cyclic alkylene, arylene or aralkylene having one to 15 carbon atoms and R.sub.1, is an alkyl having up to 6 carbon atoms, aryl or aralkyl.

A pilling polyester comprising the blended product of the following two polymers:

• a) a first polymer being the reaction product of a dicarboxylic acid or a lower alkyl ester thereof, a diol and an oxysilicon compound;
• and
• b) a second polymer being the reaction product of a dicarboxylic acid or a lower alkyl ester thereof, a diol and a carboxyphosphinic acid monomer, said monomer being used in an amount of from 0.55 to 20 mole percent based on the total amount of dicarboxylic acid or lower alkyl ester thereof and monomer, said monomer of the general formula ##STR8## or a lower alkyl ester or cyclic anhydride of said monomer wherein R is a saturated, open-chain or cyclic alkylene, arylene or aralkyl having one to 15 carbon atoms, and R.sub.1 is an alkyl having up to 6 carbon atoms, aryl or aralkyl.