Patent ID: 7390445
Filing Date: 2008-06-24
Classification: B29C,B32B

Abstract:
1. A method of producing a composite sheet having a polyolefin-based resin foam layer and a polyolefin-based resin surface layer provided on at least one side of said foam layer and containing an antistatic agent, comprising the steps of: providing a first melt comprising a first polyolefin-based resin and a physical blowing agent; providing a second melt comprising a second polyolefin-based resin having a crystallization temperature of Ta [° C.] and a melt viscosity of Ma [Pa·s], a polymeric antistatic agent having a crystallization temperature of Tb [° C.] and a melt viscosity of Mb [Pa·s] in an amount of 4 to 100 parts by weight per 100 parts by weight of said second polyolefin-based resin, and a volatile plasticizer in an amount of 5 to 50 parts by weight per 100 parts by weight of a total amount of said second polyolefin-based resin and said polymeric antistatic agent, Ta, Tb, Ma and Mb satisfying the following conditions: coextruding said first melt and second melt through a die to obtain the composite sheet.