Polyethylene resin multilayer foam sheet, interleaving paper for glass plates, and method for manufacturing polyethylene resin multilayer foam sheet
AssigneeJsp Corporation
InventorsRyuichi Taniguchi, Takashi Nishimoto
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Abstract
The multilayer foam sheet includes a polyethylene resin foam layer and a resin layer laminated on at least one of the two surfaces of the foam layer. The resin layer has a multilayer structure formed from a surface layer and an intermediate layer. Both the surface layer and the intermediate layer contain a polyethylene resin and a polymeric antistatic agent. The polymeric antistatic agent is contained in the intermediate layer at a proportion of 30-70 wt % (inclusive). The polymeric antistatic agent is contained in the surface layer at a proportion of at least 5 wt % to less than 30 wt %.
Claims10
A multilayer foam sheet, comprising a foam layer comprising a first polyethylene-based resin, and a resin layer laminated on at least one of both sides of the foam layer,
- the resin layer comprising a surface layer that is positioned on the outermost side of the multilayer foam sheet and that contains a second polyethylene-based resin and a first polymeric antistatic agent, and an intermediate layer that is positioned between the foam layer and the surface layer and that contains a third polyethylene-based resin and a second polymeric antistatic agent,
- wherein the second polymeric antistatic agent is contained in the intermediate layer in an amount of 30% by weight or more and 70% by weight or less based on the weight of the intermediate layer, and the first polymeric antistatic agent is contained in the surface layer in an amount of 5% by weight or more and less than 30% by weight based on the weight of the surface layer.
A method for manufacturing a polyethylene-based resin multilayer foam sheet having a multilayer structure in which a surface layer, an intermediate layer and a foam layer are laminated in this order, said method comprising the steps of:
- providing foamable melt for forming the foam layer containing a first polyethylene-based resin and a physical blowing agent, a first melt for forming the intermediate layer containing a second polyethylene-based resin and a first polymeric antistatic agent and a second melt for forming the surface layer containing a second polymeric antistatic agent,
- laminating the foamable melt, the first melt, and the second melt in this order in a die to form a laminated mass, and
- coextruding the laminated mass from the die to foam the foamable melt,
- wherein the first polymeric antistatic agent is contained in the first melt for forming the intermediate layer in an amount of 30% by weight or more and 70% by weight or less based on the weight of the first melt and
- the second polymeric antistatic agent is contained in the second melt for forming the surface layer in an amount of 5% by weight or more and less than 30% by weight based on the weight of the second melt.
Dependencies are inferred from the claim text.