Resin composition for a battery case for secondary battery

Abstract

There is provided a material for a battery case for secondary battery which retains the resistance to water vapor permeation, the resistance to thermal creep and the impact resistance. A resin composition for a battery case for secondary battery, comprising: (a) about 100 parts by weight of a polypropylene type resin having a density of propylene polymer portion of about 0.905 g/cm3 or more and an MFR of about 0.1 to 12, composing a matrix phase, (b) about 0.5 to 10 parts by weight of component (b-1) or (b-2), composing a dispersed phase polymer, and (c) a hydrogenated block copolymer obtained by hydrogenating a block copolymer comprising, at least, two polymer blocks A and one polymer block B: A mainly comprising vinyl aromatic compound units, and B mainly comprising conjugated diene compound units; said hydrogenated block copolymer composing a boundary surface between the component (a) and the component (b); wherein (b-1) is a hydrogenated block copolymer having a number average molecular weight of about 100,000 or more, in terms of polystyrene, as measured by gel permeation chromatography (GPC), and is obtained by hydrogenating a block copolymer comprising at least two polymer blocks A which mainly comprising vinyl aromatic compound units and at least one polymer block B which mainly comprising conjugated diene compound unit(s), wherein content of the bonded vinyl aromatic compound units being about 20 to 55 wt %, and (b-2) is a high-density polyethylene having a density of about 0.940 g/cm3 or more.

Dependencies are inferred from the claim text.