Film for labels that are removable
View Patent ↗Clear and opaque polymeric film structures for providing clear and opaque labels that are removable, respectively. The film structure includes a core layer and first skin layer, wherein the first skin layer contains a polymeric matrix of a material that allows a label, which has been produced from the film structure and applied onto a container or product, to be removed from the container or product by the solution employed in a process for re-using the container. The first skin layer is co-extruded along with the remainder of the layers of the film structure, or the first skin layer is deposited on the film structure as an emulsion or extrusion coating. The first skin layer can be contacted with a water-based adhesive to affix the label onto a particular product or product container. Labels produced from the film structure exhibit a desirable combination of excellent initial adhesion strength, moisture resistance and delaminatability, as well as excellent removability.
1. A clear polymeric film structure for producing labels that are removable, comprising:
(a) a core layer that has a first side and a second side, wherein the core layer comprises a film-forming thermoplastic polymer;
(b) a first skin layer that has a first side and a second side, wherein the first skin layer comprises polylactic acid polymer (PLA);
(c) a second skin layer that has a first and a second side, wherein the second skin layer comprises a film-forming thermoplastic polymer; and
(d) a first tie layer that has a first side and a second side, wherein the first tie layer comprises a film-forming thermoplastic olefin polymer, the first side of the first tie layer is adjacent to the second side of the first skin layer, and the second side of the first tie layer is adjacent to the first side of the core layer;
wherein each layer of the film structure is non-cavitated and the film structure is essentially free of cavitating and opacifying agents and the core layer is located between the first and second skin layers.
2. The film structure of claim 1 , wherein an outer surface of the second skin layer is treated with one or more surface treatments selected from the group consisting of flame treatment, corona treatment, plasma treatment, primer coating and metallization.
3. The film structure of claim 1 , further comprising:
(e) a second tie layer that has a first side and a second side, wherein the second tie layer comprises a film-forming thermoplastic polymer, the first side of the second tie layer is adjacent to the second side of the core layer, and the second side of the second tie layer is adjacent to the first side of the second skin layer.
4. The film structure of claim 3 , wherein the film-forming thermoplastic polymers of layers (a), (c), and (e) are each independently selected from the group consisting of polyolefins.
5. The film structure of claim 3 , wherein core layer (a) comprises isotactic polypropylene, second skin layer (c) comprises ethylene-propylene (EP) random copolymer, first tie layer (d) comprises maleic anhydride-grafted polypropylene, and second tie layer (e) comprises isotactic polypropylene.
6. The film structure of claim 3 , wherein each of layers (a), (b), (c), (d), and (e) are co-extruded layers.
7. The film structure of claim 3 , wherein each of layers (a), (c), (d), and (e) are co-extruded, and layer (b) is coated onto layer (d) as an emulsion or extrusion coating.
8. A label produced from the film structure of claim 1 , wherein the label is removable and comprises an adhesive on an outer surface of first skin layer (b).
9. A label, comprising a clear polymeric film structure, comprising:
(a) a core layer that has a first side and a second side, wherein the core layer comprises a film-forming thermoplastic polymer; and
(b) a first skin layer that has a first side and a second side, wherein the first skin layer comprises polylactic acid polymer (PLA); the first skin layer is on one of the sides of the core layer
wherein each layer of the film structure is non-cavitated and the film structure is essentially free of cavitating and opacifying agents,
wherein the label is removable and comprises an adhesive on an outer surface of the sides of first skin layer (b), and
wherein the label is a patch label and the adhesive is a cold-glue adhesive.
10. A label produced from the film structure of claim 3 , wherein the label is a patch label that is removable and comprises a cold-glue adhesive on the first side of first skin layer (b).
11. A label produced from the film structure of claim 5 , wherein the label is a patch label that is removable and comprises a cold-glue adhesive on the first side of first skin layer (b).