RESIN COMPOSITION AND MONOLAYER AND MULTILAYER FILMS

The resin composition according to the present invention contains 35-59.9 parts by mass of a propylene polymer (A) satisfying (a), 25-40 parts by mass of a flexible propylene copolymer (B) satisfying (b), 0.1-10 parts by mass of a polyolefin (C) containing a structural unit derived from an unsaturated carboxylic acid and/or a derivative thereof, and 15-30 parts by mass of an ethylene polymer (D) satisfying (d) (provided that the total amount of (A), (B), (C), and (D) is 100 parts by mass), wherein the resin composition has an MFR of 7-25 g/10 min as measured at 230°C and a load of 2.16 kg in accordance with ASTM D-1238. (a) Having a melting point (Tm) of 120°C or higher as observed by differential scanning calorimetry. (b) Having an MFR in the range of 0.01-100 g/10 min as measured at 230°C and a load of 2.16 kg in accordance with ASTM D-1238, and satisfying requirements (b-1) and (b-2). (b-1) Having a melting point (Tm) of 110°C or lower as observed by differential scanning calorimetry, or not having a melting point observed. (b-2): Having a constituent unit derived from propylene and a constituent unit derived from ethylene and at least one olefin selected from α-olefins having 4-20 carbon atoms; the contained amount of the constituent unit derived from ethylene and at least one α-olefin selected from 4-20 carbon atoms being 30 mol% or less; and having an isotactic triad fraction (mm fraction) of 80% or more as measured by 13C-NMR. (d) Being an ethylene homopolymer or a copolymer of ethylene and at least one α-olefin selected from α-olefins having 3-20 carbon atoms, and having an MFR in the range of 0.1-10 g/10 min as measured at 190°C and a load of 2.16 kg in accordance with ASTM D-1238. This monolayer or multilayer film including a layer formed of the resin composition according to the present invention has excellent adhesiveness, particularly excellent adhesiveness with a small quantity of heat, and excellent whitening resistance during a deformation process, and can be suitably used as a food packaging material, a building material, and a packaging material for forming an outer casing or the like for a lithium ion battery. The monolayer or multilayer film also exhibits good whitening resistance in a high-speed deformation process or deep drawing process. La composition de résine selon la présente invention contient 35-59,9 parties en masse d'un polymère de propylène (A) satisfaisant à (a), 25-40 parties en masse d'un copolymère de propylène souple (B