Abstract: Polymer dispersions of powders based on tungsten hydrogen bronze, especially containing a minor amount of tungsten metal, show good IR absorbing and heat shielding properties. The powders may be obtained by contacting an ammonium tungstate with hydrogen at a temperature of 2500 K or more, e.g. in a plasma.

Abstract: The present invention relates to a process for the production of polyethylene hollow articles, which process comprises charging the polyethylene with one or more NO-acyl hindered amine additives containing one or more groups of formula (I), filling this mixture into a mold, heating this mold in an oven to above 280° C., such that the additized polyethylene melts, rotating the mold around at least 2 axes, the additized polyethylene spreading to the walls, cooling the mold while still rotating, opening it, and taking the resultant hollow article out, where the group of formula (I) is where Ra is a monoacyl or diacyl radical; R1-R4 are each C1-C6alkyl; and R5 and R6 are each, independently of one another, hydrogen, C1-C6alkyl or C6-C10aryl; or R5 and R6 are together oxygen.