Method for producing skin-covered foamed molded article and resulting product

A method for producing a skin-covered foamed molded article, the method comprising the steps of:

• (a) providing a parison that is in a molten or softened state;
• (b) blow molding the parison into a skin defining a hollow interior space;
• (c) filling expanded polystyrene beads in the hollow interior space;
• and
• (d) heating the expanded polystyrene beads filled in the hollow interior space to fuse-bond the expanded polystyrene beads to each other and to form a foam layer fuse-bonded to the skin,
• wherein step (a) comprises:
• melting and kneading a mixture of 10 to 30 parts by weight of a polystyrene resin (A) having a ratio MwA(abs)/ MwA(r) of at least 1.4, where MwA(abs) and MwA(r) represent a weight average absolute molecular weight and a linear polystyrene equivalent weight average molecular weight, respectively, of the polystyrene resin (A), 5 to 30 parts by weight of an impact resistant polystyrene resin (B) containing a rubber component, and 40 to 80 parts by weight of a recycled polystyrene resin (C) to obtain a polystyrene resin composition;
• and
• extruding the polystyrene resin composition into the parison,
• wherein the total of the polystyrene resin (A), impact resistant polystyrene resin (B) and recycled polystyrene resin (C) is 100 parts by weight,
• wherein the recycled polystyrene is obtained from a resin composition which contains the polystyrene resin (A) and the polystyrene resin (B) and which has a weight ratio of the polystyrene resin (A) to the polystyrene resin (B) of 30:70 to 70:30,
• wherein the linear polystyrene equivalent weight average molecular weight MwA(r) of the polystyrene resin (A) is 3.5×105 to 4.5×105, and
• wherein the polystyrene resin composition meets the following requirements (1) to (3):
• (1) the polystyrene resin composition has a Charpy impact strength at 23° C. according to ISO179/1eA of at least 5 kJ/m2;
• (2) the polystyrene resin composition has a melt mass flow rate at a temperature of 200° C. and a load of 5 kg of 1.5 to 3.0 g/10 min;
• (3) the polystyrene resin composition has a ratio Mws(abs)/ Mws(r) of at least 1.4 where Mws(abs) and Mws(r) represent a weight average absolute molecular weight and a linear polystyrene equivalent weight average molecular weight, respectively, of the polystyrene resin composition.