PRODUCTION OF POLYPROPYLENE RESIN FOAMED SHEET HAVING BEAUTIFUL APPEARANCE

摘要

PURPOSE:To obtain a product having beautiful appearance by a method wherein polyethylene wax is added to a resin compsn. prepared using a specific polypropylene type resin and the resulting compsn. is supplied to an extruder to be mixed with a foaming agent and the obtained mixture is melted to be extruded to the atmosphere to be foamed. CONSTITUTION:A polypropylene resin effective for obtaining foam is a polymer wherein Mz is about 2.0X10<6> or more and an Mz/Mw ratio is about 3.0 or more. This polymer consists of 60-100wt.% of a camel type polypropylene resin a whose shape has the expansion of a curve showing that a branched polymer is contained in a polymeric region in a mol.wt. distribution curve due to a gel permeation chromatograph and 0-40wt.% of a propylene copolymer resin B consisting of 80-95wt.% of propylene and 5-20wt.% of alpha-olefin such as ethylene. Polyethylene wax is added to the single resin or the mixed resin and the resulting compsn. is supplied to an extruder to be mixed with a foaming agent and the obtained mixture is melted to be extruded to the atmosphere to be foamed.