Can container with screw

Abstract

To reduce a torque to open a closure of a can container having a step of a lap side seam on a thread. A threaded can container of the invention comprises: a cylindrical can body having a lap side seam 16 where longitudinal edges of a metal sheet forms a step portion; a container mouth 5 formed on an opening end of the can body where a thread ridge and a curled portion are formed thereon; a bottom lid seamed to a lower end of the can body; and a resealable closure, which is applied to the container mouth, and which has a resin sealing liner affixed to an inner face of a top panel thereof, and a thread groove rolled on a skirt portion thereof in conformity with the thread ridge; wherein the thread ridge is formed to rotate the closure in a direction from an outer edge of the lap side seam toward an inner layer of the lap side seam to open the closure.

1 . A threaded can container comprising:
 a cylindrical can body comprising a lap side seam where longitudinal edge portions of a metal sheet are overlapped thereby forming a step portion;   a container mouth formed on an opening end of the can body where a thread ridge and a curled portion are formed thereon;   a bottom lid seamed to a lower end of the can body; and   a resealable closure, which is applied to the container mouth, and which has a resin sealing liner affixed to an inner face of a top panel thereof and a thread groove rolled on a skirt portion thereof in conformity with the thread ridge;   wherein the thread ridge is formed to rotate the closure in a direction from an outer step portion formed of an outer edge of the lap side seam toward an inner layer of the lap side seam to open the closure.   
   
   
       2 . The threaded can container according to  claim 1 , wherein:
 at least an inner surface of the lap side seam of the can body is covered with a thermoplastic resin tape.   
   
   
       3 . The threaded can container according to  claim 2 , wherein:
 the thermoplastic resin film covering the lap side seam is a thermoplastic resin tape;   a circumferential width of the resin tape is within a range of 7 to 15 mm, and a thickness thereof is within a range of 15 to 45 μm;   the resin tape comprises a first layer covering the lap side seam, and a second layer of biaxially-oriented thermoplastic resin formed on the first layer to contact with a content in the can;   a melting point of the first layer is within a range of 175 to 230° C., and a melting point of the second layer is within a range of 200 to 255° C.;   the melting point of the resin forming the second layer is 15 to 80° C. higher than the melting point of the resin forming the first layer; and   the thickness of the first layer is more than 70 percent of a total thickness of the resin tape.   
   
   
       4 . The threaded can container according to  claim 3 , wherein:
 a level difference in the step portion of the lap side seam is 0.07 mm or smaller;   a diameter of the container mouth is reduced more than 15 percent in comparison with that of the can body; and   a level difference in the step portion of the lap side seam on top of the container mouth is 0.05 mm or smaller.