| abstract |
This invention provides a cap comprising a cap shell, comprising a top plate part and a skirt part, and a liner material provided on the internal surface of the top plate part in the cap shell. The cap shell is formed of a resin composition comprising a rigid aliphatic polyester resin (A) and a flexible aliphatic polyester resin (B) in a mixing weight ratio of A : B = 20 : 80 to 80 : 20. The liner material is biodegradable. By virtue of the above construction, the application of the cap to a vessel formed of a rigid biodegradable resin such as polylactic acid can provide a vessel with a cap that can effectively prevent the occurrence of resin powder upon opening/closing operation, is significantly good in sealing properties and moldability, and, at the same time, is environmentally friendly by virtue of biodegradability as the whole packaging vessel. |