| 摘要 |
The invention describes a foamable thermoplastic mixture, comprising (A) at least one thermoplastic polymer selected from ethylene-vinyl acetate copolymer (EVA), ethylene methyl acrylate copolymer (EMA), ethylene butyl acrylate copolymer (EBA), ethylene-hexene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, polyethylene (PE), polypropylene (PP) and ethylene-propylene copolymer, (B) at least one long chain branched polymer as a foam stabilizer selected from ethylene-vinyl acetate copolymer (EVA), ethylene methyl acrylate copolymer (EMA), ethylene butyl acrylate copolymer (EBA), ethylene-hexene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, polyethylene (PE), polypropylene (PP) and ethylene-propylene copolymer and (C) at least one chemical blowing agent, wherein the long chain branched polymer (B) is present in an amount of 1 to 30 wt. % relative to the total weight of thermoplastic polymer (A) and long chain branched polymer (B), and at least one of the following distinguishing features applies to the thermoplastic polymer (A) and the long chain branched polymer (B): 1) the value of the melt flow index (MFI) of the long chain branched polymer (B) (MFI(B)) is smaller than the MFI value of the thermoplastic polymer (A) (MFI(A)), wherein MFI(B) is a maximum of 50% of MFI(A), 2) the g value of the long chain branched polymer (B) (g(B)) is smaller than the g value of the thermoplastic polymer (A) (g(A)), wherein g(B) is a maximum of 80% of g(A), 3) the polymer type of the long chain branched polymer (B) differing from the polymer type of the thermoplastic polymer (A). The foamable thermoplastic mixture can be injection molded without foaming and is suitable for the production of low-density foams which can be used, for example, as damping materials or foamed membranes. |
