Patent ID: 7825165

Claim:
Expandable vinyl aromatic polymers containing an athermanous additive which comprise: a) a matrix obtained by polymerizing 50-100% by weight of one or more vinyl aromatic monomers and 0-50% by weight of at least one copolymerizable monomer; b) 1-10% by weight, calculated with respect to the polymer (a), of an expanding agent embedded in the polymeric matrix; c) 0.01-25% by weight, calculated with respect to the polymer (a), of a carbon black having an average diameter ranging from 30 to 2000 nm, a surface area ranging from 5 to 40 m 2 /g, a sulfur content ranging from 0.1 to 1000 ppm and an ash content ranging from 0.001 to 1%; d) 0-10% by weight, calculated with respect to the polymer (a), of graphite; e) 0-10% by weight, calculated with respect to the polymer (a), of aluminum; f) 0-10% by weight, calculated with respect to the polymer (a), of antimonium trisulfide; g) 0-10% by weight, calculated with respect to the polymer (a), of hydrotalcite or of an inorganic silicon compound; wherein the sum of components (a)-(g) is 100%, the concentration of the matrix (a) is not lower than 80% by weight, and at least one of (d)-(g) is present.