| 摘要 |
PROBLEM TO BE SOLVED: To prevent the bonding strength with a base body layer, and the heat-sealing strength with a container opening rim from decreasing by a fragrance component by providing a heat-sealing layer made of an aromatic polyester resin on the surface of a lid. SOLUTION: A lid for this aromatic polyester container is constituted of a heat-sealing layer made of an aliphatic polyester resin on the surface, and a base body which supports the heat-sealing layer, and the former part ensures the welding with the container opening and the shutting off of an fragrance component, and the latter part ensures a required rigidity and the shutting off of steam. As the aliphatic polyester, a polylactic resin is most suitable, and as the constituent raw material for the heat-sealing layer, a mixture with an aliphatic polyester polymer of which Tm (heat-melting temperature) is 150 deg.C or lower, or a block copolymer, and a composition of these are preferable. It is important that the tensile elasticity of the heat-sealing layer is 80 kgf/mm<2> or higher, and this can be achieved by making the ratio of the polylactic acid polymer which occupies in the total aliphatic polyester polymer of the heat- sealing layer 20-100 wt.%. |
