Patent ID: 8329821
Filing Date: 2012-12-11
Classification: B32B,C08J,C08L,Y10T

Abstract:
1. A thermoplastic elastomer composition for foaming, comprising: 10 to 40% by weight of a partially or completely crosslinked ethylene/α-olefin/non-conjugated polyene copolymer rubber (A) comprising ethylene, an α-olefin of 3 to 20 carbon atoms and a non-conjugated polyene, 3 to 33% by weight of an ethylene/α-olefin copolymer (B) comprising ethylene and an α-olefin of 3 to 20 carbon atoms, 10 to 40% by weight of polypropylene (C) having a melting point, as determined by differential scanning calorimetry (DSC), of 40 to 170° C., 10 to 45% by weight of a softener (D) for rubbers, and at least one substance selected from an isotactic propylene-based polymer (E-a) in an amount of 1 to 30% by weight and a syndiotactic α-olefin-based copolymer (E-b) in an amount of 1 to 20% by weight, with the proviso that the total amount of the components (A), (B), (C), (D), (E-a) and (E-b) is 100% by weight, wherein the component (E-a) satisfies the following requirements (i) to (iv): (i) the molecular weight distribution (Mw/Mn), as measured by gel permeation chromatography (GPC), is in the range of 1 to 10, (ii) the amount of constitutional units derived from propylene is in the range of 40 to 85% by mol and the amount of constitutional units derived from an α-olefin of 2 to 20 carbon atoms (other than propylene) is in the range of 60 to 15% by mol, (iii) the melt flow rate (MFR, ASTM D1238, 190° C., load of 2.16 kg) is in the range of 0.1 to 50 g/10 min, and (iv) in the differential scanning calorimetry (DSC), any melting point is not observed, the component (E-b) contains constitutional units (E-1) derived from propylene, constitutional units (E-2) derived from ethylene, constitutional units (E-3) derived from an olefin of 4 to 20 carbon atoms, and optionally constitutional units (E-4) derived from a conjugated polyene or a non-conjugated polyene, the component (E-h) contains the constitutional units (E-1) in an amount of 30 to 79% by mol, the constitutional units (E-2) in an amount of 1 to 30% by mol and the constitutional units (E-3) in an amount of 10 to 50% by mol, in 100% by mol of the total of the constitutional units (E-1), (E-2) and (E-3), with the proviso that the total amount of the constitutional units (E-2) and (E-3) is in the range of 21 to 70% by mol, and contains the constitutional units (E-4) in an amount of 0 to 30% by mol based on 100% by mol of the total of the constitutional units (E-1), (E-2) and (E-3), and when