Can container

Abstract

According to a first aspect of the disclosure, there is provided a manufacturing method for a can container including forming a diameter-reduced portion with a die necking tool at one end of a can body whose surface is not formed with a varnish layer, wherein a coefficient of dynamic friction between the die necking tool and the can body is 0.30 or less. In addition, according to a second aspect of the disclosure, there is provided a can container including a can trunk portion, a bottom portion provided on one end side of the can trunk portion, and a diameter-reduced portion having an outer diameter reduced at the other end side of the can trunk portion, wherein a varnish layer is not formed on an outer surface of at least the diameter-reduced portion.

What is claimed is: 
     
         1 . A manufacturing method for a can container, comprising:
 forming a diameter-reduced portion with a die necking tool at one end of a can body whose surface is not formed with a varnish layer,   wherein a coefficient of dynamic friction between the die necking tool and the can body is 0.30 or less.   
     
     
         2 . The manufacturing method for a can container according to  claim 1 , comprising forming a resin layer containing a thermoplastic resin on an outer surface of one end portion of the can body at which at least the diameter-reduced portion is formed, before forming the diameter-reduced portion. 
     
     
         3 . The manufacturing method for a can container according to  claim 2 , wherein the thermoplastic resin is a polyester resin. 
     
     
         4 . The manufacturing method for a can container according to  claim 3 , further comprising softening the resin layer by heating the can body in which the diameter-reduced portion is formed. 
     
     
         5 . The manufacturing method for a can container according to  claim 1 , wherein a smooth diamond film is formed on at least a part of a portion of the die necking tool to come into contact with the can body. 
     
     
         6 . The manufacturing method for a can container according to  claim 5 , wherein
 the die necking tool comprises a centering portion to be inserted into the can body and an insert portion to come into contact with the can body from the outside to form the can body, and   a surface of at least one of the insert portion and the centering portion to come into contact with the can body has the smooth diamond film.   
     
     
         7 . The manufacturing method for a can container according to  claim 1 , comprising forming a bottom portion and a can trunk portion by drawing a metal plate. 
     
     
         8 . The manufacturing method for a can container according to  claim 1 , comprising forming a print image layer by printing an ink composition on a surface of the can body in which the diameter-reduced portion is formed. 
     
     
         9 . A can container comprising:
 a can trunk portion;   a bottom portion provided on one end side of the can trunk portion; and   a diameter-reduced portion having an outer diameter reduced at the other end side of the can trunk portion,   wherein a varnish layer is not formed on an outer surface of at least the diameter-reduced portion.   
     
     
         10 . The can container according to  claim 9 , wherein a resin layer containing a thermoplastic resin is formed on a metal base on an outer surface of the diameter-reduced portion. 
     
     
         11 . The can container according to  claim 10 , wherein the thermoplastic resin is a polyester resin. 
     
     
         12 . The can container according to  claim 10 , wherein a print image layer is formed on the resin layer. 
     
     
         13 . The can container according to  claim 9 , wherein a print image layer is directly formed on a metal base.