NOVELTY - A Polypropylene resin, has a density in a propylene polymer portion of 0.905 g/cm3 or more and a melt flow rate of 0.1-12. The matrix phase of the polypropylene resin, 100 parts by weight, contains a resin component forming a dispersed phase.    USE - The resin composition is used for molding a secondary battery jar.    ADVANTAGE - The resin composition has superior water vapour permeability resistance, heat creep resistance, and impact resistance.    DETAILED DESCRIPTION - The resin component contains at least one of the following components (1)-(4), provided that the total amount is less than 50 parts by weight when the two or more components are contained in the resin component:    (1) a hydrogenated block copolymer, 0.5-15 parts by weight, having a number-average molecular weight in polystyrene equivalent measured by means of a gel permeation chromatography of 100000 or more. The hydrogenated block copolymer is obtained by hydrogenating a block copolymer consisting of at least two polymer blocks A using 20-70 percent by weight of a vinyl aromatic compound as its major constituent and at least one polymer block B using a conjugated diene compound as its major constituent;    (2) a high-density polyethylene having a density of 0.940 g/cm3 or more, 1-30 parts by weight, and a hydrogenated block copolymer, 0.25-15 parts by weight, obtained by hydrogenating a block copolymer consisting of at least one polymer block A using 20-70 percent by weight of a vinyl aromatic compound as its major constituent and at least one polymer block B using a conjugated diene compound as its major constituent;    (3) a high-density polyethylene having a density of 0.940 g/cm3, 1-30 parts by weight, and a hydrogenated block copolymer having a crystal melting point of 50 degrees C or higher, 0.25-15 parts by weight; and    (4) a polyphenylene ether, 1-10 parts by weight, and a hydrogenated block copolymer, 0.25-10 parts by weight, obtained by hydrogenating a block copolymer consisting of at least one polymer block A using 20-70 percent by weight of a vinyl aromatic compound as its major constituent, and at least one polymer block B using a conjugated diene compound as its major constituent.