| 摘要 |
PROBLEM TO BE SOLVED: To prevent a resin coated layer from being damaged by a method wherein a distance from the location of a tab fixing center and a finger- engaging gripping part, and an angle of the central line before turning are kept in specified ranges, and at the same time, a groove for opening having a bottom cross sectional shape of a specified radius of curvature, and a thinnest part of a specified thickness, is formed. SOLUTION: The central location of a tab fixing 2 is formed in a manner to be shifted by a distance (a) which satisfies (D-d)/2<a<d/2-1 from the center of a can lid 1 to the opposite side from an opening. In this case, D, d are the outer diameter and the inner diameter of the can lid 1. Also, a length L from the center of the tab fixing 2 to the tip end of a tab 3 is made to stay in a range of d-1>L>d/2-a, and the tab 3 is rotated around the tab fixing 2 at an angleθwhich satisfies -1<cosθ<1/(2×a×L)×[(d/2)<2> -(L<2> +a<2> )]. In addition, on the surface 1a of the can lid 1, a groove 6 for opening wherein the radius R is 0.1-1.0 mm, the thickness ts of a thinnest part 6a is in a range of 0.025-0.120 mm, and the bottom cross section is a curved surface shape, is formed.
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