摘要 |
Flame-retardant and optionally self-extinguishing polyester compositions which contain, as flame-inhibiting additive, one or more oxalato complexes, which preferably have the formula I Me@Me@ [Z(C2O4)m] (I> in which Me<I> is Li, Na, K, Rb, Cs or NH4, Me<II> is one of the abovementioned cations or Ba, Z is one of the central atoms Mg, Ba, Zr, Fe, Co, Cu, Zn, Al, Sn, Cr and Sb, and k APPROX 0, 1, 2, 3 or 4, l APPROX 0 or 1 and m APPROX 2, 3 or 4. The polyester compositions are prepared by grinding preferably alkali metal/aluminium/oxalic acid complex salts in the polyhydric alcohol or alcohols participating in the polycondensation of the polyester, and by adding the resultant suspension of the complex salt directly to the polycondensation mixture. |