EXPANDABLE VINYL AROMATIC POLYMERS

摘要

The present invention is an expandable vinyl aromatic polymer which comprises: a ) a matrix of a vinyl aromatic polymer, b ) 1-10% by weight calculated with respect to the polymer (a), of an expanding agent englobed in the polymeric matrix, c )0.1to 5% by weight calculated with respect to the polymer (a), of talc having a mean diameter above about 8 µm, said mean diameter being measured by Laser Mastersizer according to standard ISO 13320-1,the BET of the talc being is in the range 0.5-25m2/g, d) carbon black in a proportion sufficient for the foamed material obtained from the expandable vinyl aromatic polymer to have a thermal conductivity ? of about 34 m W/m°K or lower, e ) 0-20% by weight, calculated with respect to the polymer (a), of one or more fillers, other than talc and carbon black, homogeneously distributed in the polymeric matrix. The expandable vinyl aromatic polymer of the invention is produced in the form of beads or granules. The thermal conductivity ? of about 34 m W/m°K means that it could be in the range 33.5 to 34.5 mW/m°K. Advantageously the thermal conductivity ?is between about 33 and 34 mW/m°K, more advantageously between about 32 and 33 mW/m°K, preferably between about 31 and 32 mW/m°K and more preferably between about 30 and 31 m W/m°K.