Method for manufacturing low density foam panels through the extrusion of styrol polymers using hydrofluoro-olefins as propellant

摘要

Producing foam panels comprises (a) producing a polymer melt of styrene polymer or mixtures of styrene polymers, (b) introducing 0-5 wt.% infrared-absorber, based on the polymer melt, and 0-10 wt.% organic bromine compound, based on the polymer melt, and optionally additional additives, preferably nucleating agents or plasticizers, (c) introducing 1-12 pts. wt. propellant mixture made of 5-70 wt.% hydrofluorolefins and 95-30 wt.% co-propellant per 100 pts. wt. polymer melt obtained in the steps (a) and (b), to form a foamable melt, and (d) extruding the foamable melt. Producing foam panels with a density of 20-45 kg/m 3> comprises (a) producing a polymer melt of styrene polymer or mixtures of styrene polymers, (b) introducing 0-5 wt.% infrared-absorber, based on the polymer melt, and 0-10 wt.% organic bromine compound as a flame retardant, based on the polymer melt, and optionally additional additives, preferably nucleating agents or plasticizers, (c) introducing 1-12 pts. wt. propellant mixture made of 5-70 wt.% hydrofluorolefins and 95-30 wt.% co-propellant per 100 pts. wt. polymer melt obtained in the steps (a) and (b), to form a foamable melt, and (d) extruding the foamable melt into a region of lower pressure with expansion to obtain an extruded foam.