METAL STRIPS WITH METALLIC-APPEARANCE EXCELLENT IN FORMING STABILITY AND SEAMLESSLY-FORMED CAN BODY AND MANUFACTURING METHOD THEREOF
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 - 5 . (canceled)
6 . A method for manufacturing at least one metal strip with a metallic-appearance excellent in forming stability, comprising:
setting a ratio a/(a+b) at 20% to 45%, where a is a sum of the 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 - 11 . (canceled)
12 . 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 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 0.1 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 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 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.
16 . 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°.
17 . 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°.