| abstract |
A cap liner composition, which has an excellent gas barrier property and sanitary characteristics and can be opened easily in an actual use, and which is used for a sealing material for a beverage cap, is provided. A cap liner using the composition is provided as well. The cap liner composition includes (a) 100 weight parts of isobutylene-based block copolymer formed of a polymer block based on isobutylene and a polymer block formed of a monomer ingredient not based on isobutylene, and (b) 0.1 to 20 weight parts of lubricant added to the (a) isobutylene-based block copolymer. |