Abstract A method of fabricating a laminated metal container wall provided with an opening device including providing a metal sheet having a layer of protective material secured thereto by means of an adhesive selected from the group consisting of epoxy, polyester and polyurethane. The protective material is selected from a group consisting of a copolymer of a polyolefin and ethylene and ionomers of polyolefin. A preferred form of copolymer has polypropylene as the polyolefin employed with the ethylene. A preferred polypropylene ethylene copolymer may have an ethylene content of about 2 to 10 percent. The laminated metal sheet is scored to define a removable sector therein. The scoring is preferably effected to such a depth as to provide residual metal along the score line of about 2 to 6 mils. Simultaneously with the scoring operation, reducing the thickness of the layer of protective material without penetrating entirely through the layer. The protective layer may have an initial thickness of about 1.5 to 4 mils and preferably about 2.5 to 3.5 mils. A laminated metal container wall having a score line defined removable sector. An adhesive material secured to one surface of the container wall. A continuous layer of protective material secured to the metal panel portion by means of the adhesive. The protective layer may have a thickness of about 1.5 to 4 mils and is selected from a group consisting of a copolymer and a polyolefin and ethylene and ionomers of polyolefins.
The laminated container wall of claim 1 including said metal panel having a residual thickness of about 2 to 6 mils in said scored regions, said protective material having a film thickness of about 2.5 to 3.5 mils in regions not underlying said score line, said protective material having a reduced thickness in the regions underlying said score line, said protective material is selected from the group consisting of a copolymer of a polyolefin and ethylene with an ethylene content by weight of about 2 to 5% and polyethylene acrylate, and said adhesive selected from the group consisting of epoxy, polyester and polyurethane.
Claim 2
Dependent Claim
45 words
The metal container wall of claim 2 including said adhesive being a coating of about 1.0 to 5.0 milligrams per square inch, and said protective material is a copolymer of polypropylene and ethylene with an ethylene content by weight of about 2 to 5 percent.
Claim 3
Dependent Claim
52 words
The metal container wall of claim 3 including said adhesive being a coating of 1.0 to 3.0 milligrams per square inch, and said protective material within regions underlying said score line having a thickness of about 10 to 50 percent less than the average thickness of the remainder of said protective material.