| 摘要 |
PURPOSE:To improve sealing capacity by a method wherein a lid consists of a metal inner lid and a plastic outer lid, the mold shrinkage rate and flexural rigidity of the outer lid are specified, and the outer lid can be sealed to the inner lid so that it can be separated from the inner lid via a paint layer including a cohesive failing adhesion agent on the top plate of the inner lid. CONSTITUTION:A metal inner lid 1 consists of a top plate 2, a skirt 3 and an opening 4, and an outer lid 10 consists of a top plate 11, a skirt 12 and a jaw 3. On the upper face of the top plate 2, a paint film containing a cohesive failing adhesion agent is provided, via which the plastic outer lid 10 is adhered. The outer lid has a mold-shrinkage rate less than 5% and flexural rigidity of 6000 to 13000kg/cm<2>. The paint film containing the cohesive failing adhesion agent contains a cohesion failing adhesion agent and modified olefin resin with a weight ratio of 1:2 or 1:20. As a cohesion failing adhesion agent, an aliphatic hydrocarbon group, aliphatic acid, aliphatic alcohol or the like is used, and as the paint for composing this, one having high adhesion with metal and good corrosion resistance is desirable. This enables sufficient sealing reliability to be maintained and easy separation when opened. |
