Patent ID: 7989083

Claim:
An acid-modified polypropylene resin, which is obtained by grafting an organic acid component to a polypropylene resin, wherein the polypropylene resin is an isotactic polypropylene resin, the grafted amount X (wt %) of the organic acid component in the acid-modified polypropylene resin is within a range of from 1.0 to 20.0 (wt %), and the melt flow rate Y (g/10 min) of the acid-modified polypropylene resin satisfies the expression: Y< 18.5 exp (0.82 X ) (1), wherein the acid-modified polypropylene resin is obtained by a process which comprises mixing a polypropylene resin, an organic acid component and an organic peroxide, represented by the formula (2), with heating, to obtain the acid-modified polypropylene resin: R 1 -A-R 2 (2) wherein A is a bivalent connecting group containing at least one structure represented by —O—CO—O—O—, and each of R 1 and R 2 which are independent of each other, is a C 1-9 saturated or unsaturated hydrocarbon group.