PURPOSE: To automatically close a container tightly with its lid by heating the lid left half-open with a vapor from the hot water poured in the container.
CONSTITUTION: The lid consisting of a laminated sheet 6 constituted of a base material layer 2, an adhesive layer 3, a base material layer 4 and a heat-sealable resin layer 5 is thermally fused on a container via the resin layer 5 to such an extent as to be strippable therefrom. The base material layer 2 is formed from the thermoplastic resin film having a thermal expansion coefficient of 0.4-2.0% and a tensile elastic modulus of 5,000-50,000kg/cm2 when its temp. is raised from 30°C to 80°C for 5 minutes at a temp. rise rate of 10°C/minute under a load of 1g and the relationship in thermal property between the base material layers 2 and 4 satisfies the following: 0<{T(A)-S(A)}+{S(B)-T (B)}<2.0. wherein T(A) is the thermal expansion coefficient of the base material layer 2 in the separating direction, S(A) is the thermal contraction coefficient thereof in the separating direction, T(B) is the thermal expansion coefficient of the base material layer 4 in the separating direction and S(B) is the thermal contraction coefficient thereof in the separating direction.
HOSONO TAIJI
FUNATO TAKASHI
MIYAJI TAKASHI
