IMPROVED POLYAMIDE COMPOSITIONS FOR LED APPLICATIONS

摘要

The invention relates to polyamide composition comprising at least one polyamide featuring a melting temperature (Tm), at least one metal oxide selected from magnesium oxide, zinc oxide and calcium oxide, and titanium dioxide, said composition featuring an intrinsic melt viscosity of below 800 Pa·s as measured according to ASTM D3835-08 at a moisture content as measured according to ASTM D6869-03 in the range of 150-500 ppm at a shear rate of 400 s−1 and at a temperature ranging from [(Tm max) +10° C.] to [(Tm max)+20° C.] where (Tm max) is the highest of all melting temperatures(Tm). Invented compositions feature high reflectivity in the molded part with high retention of whiteness and reflectivity after heat aging. This unique combination of properties makes the compositions according to the invention most suitable for LED applications.