Patent ID: 6878513

Claim:
A modified gelatin obtained by reacting (A) a gelatin and (B) a compound which contains a nitrogenous aromatic ring having a mercapto group to a form covalent bond with a reactive group in the gelatin, wherein the modified gelatin is represented by the following formula (I): Gel-L 1 -L 2 -Z-SH) n (I) Where Gel represents a gelatin, L 1 represents a group selected from —C(═O)O—, —NH—, —N═, —N<, —O—, —S—, —NH—C(═NH 2 + )NH— and —NH—C(═NH)NH— existing in the gelatin, L 2 represents a divalent or trivalent coupling group, Z represents a nitrogenous aromatic heterocycle group, n is 1 or 2, and the amount of the modifying group represented by L 2 -Z-SH is from 1.0×10 −6 mol to 2.0×10 −3 mol per 100 g of the gelatin.