LAMINATED EXPANDED SHEET OF POLYSTYRENE-BASED RESIN WITH EXCELLENT DEEP DRAW FORMING PROPERTIES

摘要

PROBLEM TO BE SOLVED: To provide a laminated expanded sheet, of polystyrene-based resin with excellent deep draw forming properties, which can be molded into a container with excellent strength.;SOLUTION: This expanded sheet of a polystyrene-based resin is used for molding a container by laminating a non-expanded film of a polystyrene-based resin on one surface of the sheet. A styrene-based resin composition is composed of a linear polystyrene with 250,000 to 450,000 mass average molecular weight and a multi-branching polystyrene with 1,000,000 to 10,000,000 mass average molecular weight as a base material resin. In addition, the mass ratio of the linear polystyrene to the multi-branching polystyrene is 70:30 to 30:70. The composition also has 250,000 to 750,000 mass average molecular weight, and is extrusion-expanded. Further, the expanded sheet of the polystyrene-based resin has not less than 200 g/m² amount applied, 2.1 to 3.0 wt.% residual foaming agent, 0.25 to 0.40 g/cm³ density of the surface layer part with 150 μm thickness from the surface, of the area where the non-expanded film is not laminated. This expanded sheet of the polystyrene-based resin is used to obtain the laminated expanded sheet of the polystyrene-based resin with the excellent deep draw forming properties.;COPYRIGHT: (C)2007,JPO&INPIT