Process for production of easy-open can lid made of resin laminated metal sheet, easy-open can lid, and resin laminated metal sheet for easy-open can lid

摘要

A process for productive an easy-open can lid made of a resin laminated metal sheet comprising laminating a metal sheet or surface-treated metal sheet on one or both surfaces thereof with a crystalline saturated polyester resin film having a thickness of 10 to 100 μm, an elongation of at least 150%, a degree of crystallinity of not more than 10%, and a heat of fusion of crystalline of not less than 10 joules/g, to form a laminated metal sheet for an easy-open can, forming by a composite cold-forming method a tear-along grooves of a residual thickness of not more than ½ of the thickness of the material using top and bottom dies of a die radius of 0.1 to 1.0 mm, then heat treating the crystalline saturated polyester resin layer at the portion surrounding the tear-along groove at a temperature of at least the crystallization starting temperature and less than the melting point thereof and, also, an easy-open can lid obtained by the same and a resin laminated metal sheet used for the same.