| abstract |
The invention relates to a polyester composition comprising a polybutylene terephthalate resin (PBT) and at least one additive, wherein the composition has a cyclic dimer content of less than 0.35 wt.% relative to the weight of the PBT. The invention also relates to moulded parts, prepared from this polyester composition, and mirror optic systems such as headlights for motor vehicles or garden reflector lights, comprising these moulded parts. The invention further relates to a PBT having a cyclic dimer content of less than 0.35 wt.%, a process for preparing this PBT and the use of the PBT for preparing the polyester composition according to the invention. |