Process for preparing foaming polystyrene plastics with shortened time of cooling mouldings in the mould and with enhanced utility properties

摘要

The invented foaming polystyrene plastics are prepared in such a manner that an internal additive being formed by a mixture of partial esters of unsaturated higher fatty acids with pentaerythritol, optionally combination thereof with partial esters of unsaturated higher fatty acids with glycerol is proportioned in the amount ranging from 0.01 to 0,80 parts by weight either in the course of suspension polymerization or during additional impregnation of the polystyrene plastic particles. Subsequently the polystyrene plastic particles are coated with 0.03 to 0.60 percent by weight three-component mixture of surface additives the components of which mixture are partial esters of higher fatty acids with sorbitol or pentaerythritol, optionally a combination of some thereof with partial esters of indicated acids with glycerol in an amount ranging from 0.01 to 0,20 percent by weight, further monoesters of saturated higher fatty acids and glycerol in an amount ranging from 0.01 to 0.30 percent by weight and the third component is represented by metal salts of stearic acid in an amount ranging from 0.01 to 0.10 percent by weight, whereby all the weight percentages are based on the foaming polystyrene.