Abstract: A heat-resistant cap for a container wherein the container includes a mouth having an external circumferential recess and a boss; an intermediate stopper having a latching portion engaged in pressure fit relation over the mouth such that a ridge provided on an inner circumferential surface of an intermediate tube is held in pressure fit relation with the external circumferential recess. An embrittled line is formed to extend circumferentially in the inner circumferential surface of the intermediate tube contiguous to an upper or lower edge of the recess. An outer lid is fitted over the intermediate stopper. An engagement portion provided on the outer lid is engaged in vertical relation with a latching portion of the intermediate stopper having a portion held in pressure fit relation with an outer circumferential surface of the intermediate tube.

Abstract: A cap made of synthetic resin coming into mesh with a mouth of a container is provided, wherein the cap comprises a tubular member made of synthetic resin, a ring provided integrally with a lower end of the tubular member through easily frangible joint pieces, a multiplicity of engagement members formed to extend obliquely upward from an inner lower end of the ring and to have a uniform thickness as a whole, the engagement members being each inclined along both sides thereof so as to spread toward their upper end and project radially inward to have an arc-shaped bulged portion, junctions at which opposite upper side ends of the adjacent engagement members are integrally connected to each other, and thin films formed to cover areas defined by the ring and the adjacent engagement members, and the container has a mouth provided with a screw-shaped groove cooperating with the cap and an annular projection formed below the screw-shaped groove and engaging the engagement members.

Abstract: As opening/closing device to be provided at a mouth of a container such as a paper container, a bottle, a can, etc., in which a lid is provided via a hinge on the inside of a cylindrical pouring mouth made of synthetic resin and a gap space is formed between the pouring mouth and the lid. A metallic film consisting of a metal foil having synthetic resin layers coated on its both surfaces is bonded so as to straddle both the upper surface of the lid and the upper surface of the pouring mouth. Opening of the lid is effected by peeling of the metallic film, and upon closing the lid, the metallic film is pressed from its outer surface so that it may be stuffed in the gap space between the lid and the pouring mouth. Upon making the opening/closing device, an annular protrusion is formed on the top end surface of the pouring mouth, the metallic film is bonded to this annular protrusion and the lid so that the metallic film may be easily peeled off.