Coated polyolefinic films having low adhesion to the welding bars
AssigneeMoplefan S.p.A.
InventorsLuigi Mauri, Rino Cardaio
Life of this patent
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Abstract
Films comprising alpha-olefin polymers, such as polypropylene consisting essentially of recurring propylene units and having a substantial crystalline polypropylene content, and in particular isotactic polypropylene, are rendered poorly adhesive to the welding bars of automatic and semi-automatic machines conventionally used for the manufacture of containers, envelopes, bags, vessels and, in general, other manufactured articles useful in the packaging industry, by coating the films by a mixture of a copolymer of a vinyl ester with an unsaturated acid, a terpolymer of an alkyl acrylate, an alkyl-methacrylate and an unsaturated acid and a cross-linking amine.
Claims9
A polyolefinic film having low adhesion to welding bars, coated on one or both sides with a coating agent consisting of a mixture of:
- from 50% to 90% by weight of a copolymer consisting of from 95% to 85% by weight of a vinyl ester and of from 5% to 15% by weight of an unsaturated acid;
- from 49.5% to 9.5% by weight of a terpolymer consisting of from 25% to 40% by weight of at least one alkyl-acrylate, from 70% to 40% be weight of at least one alkyl-methacrylate and from 5% to 20% by weight of an unsaturated acid;
- and
- from 0.5% to 1.5% by weight of a C.sub.1 -C.sub.4 polyalkylene-imine having a cross-linking action.
Dependencies are inferred from the claim text.