| 摘要 |
Particles of a foamable resin comprise a vinylaromatic polymer, a volatile blowing agent such as butane or pentane and a liquid aliphatic hydrocarbon additive containing from 7 to 12 carbon atoms and having a boiling point at atmospheric pressure between 95 DEG and 220 DEG C. Preferably, the hydrocarbon additive has a viscosity not greater than 10 centipoises at 25 DEG C. Specified additives are white spirit, n-heptane, octanes, nonanes, decanes and dodecanes and mixtures of these. A finely-divided inert solid, e.g. silica, in the form of a coating on the surface of the particles may also be included. The polymer may be polystyrene, poly a -methylstyrene or a copolymer of styrene with 10-20% of methyl methacrylate, acrylonitrile or butadiene. |
