| abstract |
A sealing material for caps, e.g., metal caps for food containers, which is reduced in swelling with substances dissolved out or alcoholic beverages and in adsorption of the odor thereof and which comprises a tough and nonyellowing polyurethane elastomer and has satisfactory sealing performance. The sealing material for caps comprises a polyurethane elastomer obtained by reacting the following (A), (B), and (C). (A) A polyisocyanate ingredient which is obtained by modifying an aliphatic isocyanate and/or alicyclic isocyanate and has an isocyanate group content of 5-38 mass% and an average functional-group number of 2-3. (B) A polyol ingredient having a hydroxy value of 20-350 (mg-KOH/g) and an average functional-group number of 2-3. (C) A fatty acid/glycerol ester having a hydroxy group. |