Asymmetric multilayered polymeric film and label stock and label thereof
View Patent ↗A polymeric film for labeling articles comprises an asymmetric multilayered film comprising specialized skin and core layers whose compositions address multiple needs including adhesion of a printing ink and an adhesive and die-cuttability. The polymeric film provides improved performance in the conversion to an adhesive containing label stock and adhesive label.
1. A polymeric film for labeling articles, comprising:
(A) a print skin layer having an upper surface and a lower surface and comprising at least one polyethylene having a density of up to 0.94 g/cm3 and at least one polypropylene;
(B) a core layer having an upper surface and a lower surface and comprising at least one polypropylene copolymer, at least one polypropylene homopolymer, and at least one polyethylene prepared by Ziegler-Natta or metallocene catalysis and having a density ranging from 0.86 to 0.98 g/cm3;
(C) an adhesive skin layer having an upper surface and a lower surface and comprising at least one polyolefin grafted with an unsaturated carboxylic acid or unsaturated carboxylic acid derivative wherein the lower surface of the print skin layer (A) overlies the upper surface of the core layer (B), and the upper surface of the adhesive skin layer (C) underlies the lower surface of the core layer (B); and
wherein the core layer comprises from about 50% to about 85% of at least one propylene copolymer, from about 5% to about homopolymer and from about 5% to about 25% of at least one polyethylene.
2. The film of claim 1 wherein the at least one polyethylene in the core layer (B) has a density of from 0.870 to 0.98 g/cm3.
3. The film of claim 2 wherein the core layer comprises on a weight basis from about 50 to about 85% of the polypropylene copolymer, about 5 to about 25% of the polypropylene homopolymer, and about 5 to about 25% of a linear low density polyethylene.
4. The film of claim 1 wherein the adhesive skin layer (C) also comprises at least one propylene homopolymer.
5. The film of claim 1 wherein the adhesive skin layer comprises from about 10 to about 90% by weight of at least one polyolefin grafted with an unsaturated carboxylic acid or unsaturated carboxylic acid derivative and from about 10 to about 90% of at least one propylene homopolymer.
6. The film of claim 5 wherein the polyolefin grafted with an unsaturated carboxylic acid is a maleic anhydride grafted polypropylene.
7. The film of claim 1 wherein the film is prepared by a coextrusion of the layers (A), (B) and (C).
8. The film of claim 1 wherein the film is oriented.
9. The film of claim 8 wherein the film is oriented uniaxially in the machine direction.
10. The film of claim 1 wherein the print skin layer (A) comprises at least one linear low density polyethylene and at least one polypropylene homopolymer.
11. The film of claim 1 wherein the polyethylene of the core layer (B) comprises at least one linear low density polyethylene.
12. The film of claim 1 wherein the print skin layer (A) comprises on a weight basis from about 60% to about 90% of at least one polyethylene and from about 10% to about 40% of at least one polypropylene.
13. The film of claim 1 wherein the print skin layer (A) comprises on a weight basis, from about 60% to about 90% of at least one linear low density polyethylene and from about 10 to about 40% of at least one propylene homopolymer.
14. The film of claim 1 wherein the print skin layer also comprises from about 1 to about 10% of at least one antiblock agent.
15. The film of claim 1 wherein the adhesive skin layer (C) comprises a maleic anhydride grafted polypropylene.
16. The film of claim 1 further comprising (D) a tie layer having an upper surface and a lower surface and comprising at least one polypropylene copolymer, at least one polypropylene homopolymer, and at least one polyethylene prepared by Ziegler-Natta or metallocene catalysis having a density ranging from 0.086 to 0.98 g/cm3 wherein the upper surface of the tie layer is in contact with the lower surface of the print skin layer (A) and the lower surface of the tie layer is in contact with the upper surface of the core layer (B), and the core layer (B) further comprises recycled film.
17. The film of claim 16 wherein the density of the polyethylene in the tie layer is from 0.870 to 0.98 g/cm3.
18. An adhesive containing label stock, comprising: the film of claim 16 ; and
(E) an adhesive layer having an upper surface and a lower surface wherein the upper surface of the adhesive layer is adhesively joined to the lower surface of the adhesive skin layer (C) of the film.
19. The label stock of claim 18 further comprising (F) a release finer wherein the release liner is releasably joined to the lower surface of the adhesive layer (E), and the adhesive layer (E) is a pressure sensitive adhesive layer.
20. An adhesive label die-cut from the label stock of claim 19 .
21. The film of claim 1 wherein the film is clear.
22. The film of claim 1 wherein the core layer also contains a pigment.
23. The film of claim 1 wherein the film is opaque.
24. A polymeric film for labeling articles, comprising:
(A) a print skin layer having an upper surface and a lower surface and comprising at least one polyethylene having a density of up to 0.94 g/cm3 and at least one polypropylene;
(B) a core layer having an upper surface and a lower surface and comprising at least one polypropylene copolymer, at least one polypropylene homopolymer, and at least one polyethylene prepared by Ziegler-Natta or metallocene catalysis and having a density ranging from 0.86 to 0.98 g/cm3;
(C) an adhesive skin layer having an upper surface and a lower surface and comprising at least one polyolefin grafted with an unsaturated carboxylic acid or unsaturated carboxylic acid derivative wherein the lower surface of the print skin layer (A) overlies the upper surface of the core layer (B), and the upper surface of the adhesive skin layer (C) underlies the lower surface of the core layer (B); and
(E) an adhesive layer having an upper surface and a lower surface wherein the upper surface of the adhesive layer is adhesively joined to the lower surface of the adhesive skin layer (C) of the film.