WERKWIJZE VOOR HET VERVAARDIGEN VAN GEEXTRUDEERDE GESCHUIMDE KUNSTSTOFFEN

摘要

1323879 Laminates SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ NV 20 Oct 1970 [8 Dec 1969] 59798/69 Heading B5N [Also in Division C3] A laminate comprises a sheet of a cellular product laminated to a sheet of a toughened polyvinyl aromatic compound. The cellular product is made by mixing particles of a polymeric vinyl aromatic compound containing an expanding agent with at most 50% by wt. of an elastomer-toughened polymeric vinyl aromatic compound containing at least 10% by wt. of a lubricant, the resulting polymer blend being extruded at a temperature sufficient to activate the expanding agent and to soften the blend. The polymeric vinyl aromatic compound may be polystyrene and the elastomer in the toughened polymer may be natural rubber, polybutadiene or an acrylonitrile/butadiene/styrene or styrene/ butadiene rubber. The lubricant may be a mineral oil, petroleum jelly or paraffin wax. The polymer blend may also contain zinc or calcium stearate. The expanding agent may be pentane. The expandable granules may be coated with white oil, citric acid sodium bicarbonate and calcium stearate prior to mixing with the toughened polymer. The laminate may be shaped by application of pressure, vacuum and/or heat into a form embodying strengthening elements and hinge elements so as to form a long-flat package.