Metal band having metallic appearance excellent in forming stability and seamlessly formed can body and method for production thereof

Abstract

A metal band having metallic appearance and being excellent in forming stability is provided. The metal band includes a coating film containing not less than 20 mass % in the coated and dried state, of filler of aluminum or aluminum alloys on the side thereof corresponding to the outside of a can. The metal band also has a resin-rich portion containing not more than approximately 5 mass % of the filler, approximately 0.1 to 20 μm in thickness in the coated surface far from the metal strip surface, seamlessly-formed can bodies made of such strips. Methods for manufacturing such strips and can bodies are also provided.

1 . A metal strip with metallic-appearance excellent in forming stability, having a single coated film layer on the side thereof corresponding to an external side of a can, the metal strip comprising: 
 a filler-rich portion containing not less than approximately 20 mass %, in the coated and dried state, of a filler of at least one of aluminum or aluminum alloys; and    a resin-rich portion containing not more than approximately 5 mass % of said filler and approximately 0.1 to 20 μm in thickness provided upon the filler-rich portion,    wherein the filler-rich portion is dilutely distributed in the direction of thickness of the coated film layer.    
   
   
       2 . A metal strip with metallic-appearance excellent in forming stability, having a single coated film layer on the side thereof corresponding to an external side of a can, the metal strip comprising: 
 a filler-rich portion containing not less than approximately 20 mass %, in the coated and dried state, of a filler of at least one of aluminum or aluminum alloys; and    a resin-rich portion containing not more than approximately 5 mass % of said filler and approximately 0.3 to 10 μm in thickness provided upon the filler-rich portion,    wherein the filler-rich portion is dilutely distributed in the direction of thickness of the coated film layer.    
   
   
       3 . A metal strip of  claim 1 , further comprising a resin film not less than approximately 8 μm thick which is laminated on the side thereof corresponding to an internal side of said can.  
   
   
       4 . A metal strip of  claim 1 , further comprising at least one of a polyester or polyolefin resin film which is laminated on the side thereof corresponding to an the internal side of said can.  
   
   
       5 . A metal strip with of  claim 1 , wherein the coated film layer on the external side of said can contains one or more of polyester, epoxyphenol and vinyl organosol.  
   
   
       6 . A method for manufacturing at least one metal strip with a metallic-appearance excellent in forming stability, comprising: 
 setting a the ratio a/(a+b) at 20% to 45%, where a sum of weights of a filler of at least one of aluminum or aluminum alloys and resin in a paint, and (a+b) is a sum of a and b of organic solvent for dissolving the paint, and    at least one of roll-coating or photogravure-coating at a linear pressure of at least approximately 3 kg/cm between the metal strip and rolls by using coating-rolls having a diameter of at most approximately 500 mmΦ.    
   
   
       7 . A method of  claim 6 , wherein a statistic viscosity of the paint applied by roll-coating is approximately 20 to 350 centipoise at 20° C.  
   
   
       8 . A seamlessly-formed can body, comprising: 
 a filler-rich portion containing not less than 5 mass %, in the coated and dried state, of a filler of at least one of aluminum or aluminum alloys on a side thereof corresponding to an outside of a can, and    a resin-rich portion containing at most approximately 5 mass % of said filler, and approximately 0.03 μm in thickness Provided upon the filler-rich portion,    wherein the filler-rich portion is dilutely distributed in the direction of a coated layer thickness.    
   
   
       9 . A seamlessly-formed can body, comprising: 
 a filler-rich portion containing not less than 20 mass %, in the coated and dried state, of a filler of at least one of aluminum or aluminum alloys on a side thereof corresponding to an outside of a can, and    a resin-rich portion containing at most approximately 5 mass % of said filler, and approximately 0.03 μm in thickness provided upon the filler-rich portion,    wherein the filler-rich portion is dilutely distributed in the direction of a coated layer thickness.    
   
   
       10 . A seamlessly-formed can body of  claim 8 , wherein the body has a laminated resin film.  
   
   
       11 . A seamlessly-formed can body of  claim 8 , wherein the body has a resin film of one or more of polyester, epoxyphenol and vinyl organosol.  
   
   
       12 . A method for manufacturing a seamlessly-formed can body, by comprising: 
 applying multistage ironing to a metal strip with a thickness reduction ratio γ by using two or more dies such that a Total thickness reduction ratio γ<58+11d0.35 (wherein d is a thickness (μm) of the resin-rich portion containing at most approximately 5 mass % of filler in a coated surface at distance from a coated side),    wherein the metal strip has a single coated film layer on the side thereof corresponding to an external side of a can, the metal strip comprising: 
 a filler-rich portion containing not less than approximately 20 mass %m, in the coated and dried state, of a filler of at least one of aluminum or aluminum alloys, and  
 a resin-rich portion containing not more than approximately 5 mass % of said filler and approximately 0.1 to 20 μm in thickness provided upon the filler-rich portion, and  
   wherein the filler-rich portion is dilutely distributed in the direction of thickness of the coated film layer.    
   
   
       13 . A method of  claim 12 , wherein the ironing is performed by using a die whose intersection point between the entry and exit half angles has a radius of curvature not less than 0.02 mmΦ, and an entry half angle is set at 2° to 10°.  
   
   
       14 . A method of  claim 12 , wherein the ironing is performed by using a die whose intersection point between the entry and exit half angles has a radius of curvature not less than 0.1 mmΦ, and an entry half angle set at 2° to 18°.  
   
   
       15 . A metal strip of  claim 2 , further comprising a resin film not less than approximately 8 μm thick which is laminated on the side thereof corresponding to an internal side of said can.  
   
   
       16 . A metal strip of  claim 2 , further comprising at least one of a polyester or polyolefin resin film which is laminated on the side thereof corresponding to an internal side of said can.  
   
   
       17 . A metal strip of  claim 2 , wherein the coated film layer on the external side of said can contains one or more of polyester, epoxyphenol and vinyl organosol.  
   
   
       18 . A seamlessly-formed can body of  claim 9 , wherein the body has a laminated resin film.  
   
   
       19 . A seamlessly-formed can body of  claim 9 , wherein the body has a resin film of one or more of polyester, epoxyphenol and vinyl organosol.  
   
   
       20 . A method for manufacturing a seamlessly-formed can body, comprising: 
 applying multistage ironing to a metal strip with a thickness reduction ratio γ by using two or more dies such that a Total thickness reduction ratio γ<58+11d0.35 (wherein d is a thickness (μm) of the resin-rich portion containing at most approximately 5 mass % of filler in the a coated surface at distance from a coated side),    wherein the metal strip has a single coated film layer on the side thereof corresponding to an external side of a can, the metal strip comprising: 
 a filler-rich portion containing not less than approximately 20 mass %, in the coated and dried state, of a filler of at least one of aluminum or aluminum alloys, and  
   a resin-rich portion containing not more than approximately 5 mass % of said filler and approximately 0.3 to 10 μm in thickness provided upon the filler-rich portion, and    wherein the filler-rich portion is dilutely distributed in the direction of thickness of the coated film layer.    
   
   
       21 . A method of  claim 12 , wherein the ironing is performed by using a die whose intersection point between the entry and exit half angles has a radius of curvature not less than 0.02 mmΦ, and an entry half angle is set at 2° to 10°.  
   
   
       22 . A method of  claim 12 , wherein the ironing is performed by using a die whose intersection point between the entry and exit half angles has a radius of curvature not less than 0.1 mmΦ, and an entry half angle set at 2° to 18°.