Peelable laminated structures and process for production thereof

A sealed container comprising a hollow body for holding an object, an opening in a wall of said body, a rim surrounding said opening and a flexible closure element overlapping and attached to said rim and closing said opening, said rim comprising a layer of a metal selected from the group consisting of aluminum and aluminum alloys that are anodizable to form a porous anodic surface film, at least one other layer selected from the group consisting of a portion of the wall of said hollow body and a portion of the closure element and a bonding structure attaching the metal at least one layer to the other layer, said bonding structure comprising a porous anodic film incorporating an internal stratum that is weakened in comparison to a remainder of the anodic film and that has a peel strength high enough to resist separation of the bonding structure at said weakened stratum except upon deliberate peeling apart of said body and said closure element at said rim, wherein said anodic film incorporating said stratum is a film produced by porous anodization of a surface of said metal layer in an electrolyte and at a voltage which results in the formation of said porous anodic film, continuing said porous anodization while carrying out a voltage reduction procedure in order to introduce a weakened stratum into said anodic film, and allowing said film to stand in said electrolyte or other acidic solution for a period of time to further weaken said film along said stratum;

• and wherein said at least one other layer is attached to said anodic film of said bonding structure by an adhesive, said adhesive having a peel strength greater than said peel strength of said weakened stratum.