Shaped articles of porous styrene polymers having impact-resistant surfaces and a method for the production of such shaped articles

摘要

A shaped article comprises a porous cellular styrene polymer with an impact-resistant surface at least 51 per cent by volume of which comprises a porous cellular styrene polymer of low specific gravity, an impact resistant layer of a copolymer of an unsaturated polyester resin with a liquid vinyl compound which only partly covers the surface of the shaped article, and a layer of a porous cellular styrene polymer of higher specific gravity arranged in between. The liquid vinyl compound is preferably styrene. The article is produced by partially covering the inside of a mould capable of being closed in a non-gastight manner with a layer of an initially polymerized mixture of an unsaturated polyester resin and a vinyl compound, covering this with a layer of particles of polystyrene containing 3-15 per cent of a volatile non-solvent organic liquid, filling the remainder of the mould with pre-expanded cellular particles of a polystyrene which are still expandable then heating to expand and copolymerize. Specification 715,100 is referred to.