Environmentally-friendly steel sheet for a can or a container as well as laminated and pre-coated steel sheet by using it
View Patent ↗Laminated steel sheet for a container material with a small environmental load container material and coating pre-coated steel sheet for a container material characterized by comprising steel sheet having on it a tin layer or iron-tin alloy layer which has on it a tin oxide layer of a thickness measured by an electric stripping method of 0 mC/cm 2 to 3.5 mC/cm 2 and has further formed on that a foundation layer including a zirconium compound not including fluorine or nitrate nitrogen, having an amount of coating converted to zirconium of 1 mg/m 2 to 30 mg/m 2 , and having an amount of sulfuric acid radicals (SO 4 2− ) of 0 mg/m 2 to 7 mg/m 2 .
1. A steel sheet for a can or a container comprising:
a tin layer or iron-tin alloy layer on the steel sheet, wherein the tin layer or iron-tin alloy layer comprises Sn in an amount in the range of 2.8 g/m 2 to 12 g/m 2 ;
an optional tin oxide layer of a thickness measured by an electric stripping method of 0 mC/cm 2 to 3.5 mC/cm 2 on the tin layer or iron-tin alloy layer; and
a chrome-free foundation layer on the tin oxide layer if present or on the tin layer or iron-tin alloy layer if the tin oxide layer is not present including zirconium oxide, zirconium hydroxide, or a composite thereof in an amount converted to zirconium in the range of 1 mg/m 2 to 30 mg/m 2 , wherein the chrome-free foundation layer optionally includes an amount of sulfate radical (SO 4 2− ) in the range of 0 mg/m 2 to 7 mg/m 2 .
2. The steel sheet for a can or a container as set forth in claim 1 , wherein said chrome-free foundation layer does not contain either fluorine or nitrate nitrogen.
3. The steel sheet for a can or a container as set forth in claim 1 , wherein the steel sheet further comprises a laminated film on the chrome-free foundation layer.
4. The steel sheet for a can or a container as set forth in claim 1 , wherein the steel sheet comprises a tin oxide layer.
5. The steel sheet for a can or a container as set forth in claim 4 , wherein the tin oxide layer has a thickness measured by an electric stripping method from 0.01 to 3.5 mC/cm 2 .
6. The steel sheet for a can or a container as set forth in claim 4 , wherein said chrome-free foundation layer does not contain either fluorine or nitrate nitrogen.
7. The steel sheet for a can or a container as set forth in claim 4 , wherein the steel sheet further comprises a laminated film on the chrome-free foundation layer.