Coating or polymeric labels
View Patent ↗This invention provides a polymer film coating for use preferably with cold glue labels, particularly on the adhesive-receiving side of a label film. The coating includes a filler component and a binder component, at least one of which is hydrophobic. The coating imparts water resistance and solvent resistance to an adhered label, thereby improving resistance to label removal due to moisture or water contact. A coated label and method of applying the coating to a label film are also included.
1. A coated label film for use with a cold glue adhesive, the label film comprising:
(a) a polymeric substrate comprising:
(i) a first skin layer comprising a polymer, wherein the first skin layer has a first side and a second side and is voided;
(ii) a core layer comprising a polymer, wherein the core layer has a first side and a second side, and the first side of the core layer is adjacent to the second side of the first skin layer;
(b) a first coating on the first side of the first skin layer comprising at least 30 wt % of a first filler component, the filler component comprising polyethylene homopolymer or copolymer particles having a mean diameter in the range of greater than 10 μm to equal to 20 μm and <2.0% of the filler particles have a diameter >75.0 μm, and a first binder component, the first binder comprising:
(i) at least an ionomer having about 65 wt % to about 95 wt % of polymer units derived from at least one of ethylene, propylene, butylene, and one or more carbonyl-free monomers; and from about 5 wt % to about 35 wt % of polymer units derived from at least one of acid-group containing comonomer selected from acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and mixtures thereof,
(ii) an acrylic emulsion,
(iii) a first cross-linking agent, and
wherein at least one of the first filler component and the first binder component is hydrophobic.
2. The coated film according to claim 1 , wherein the polymeric substrate (a) further comprises:
(iii) a second skin layer comprising a polymer, wherein the second skin layer has a first side and a second side, the first side of the second skin layer is adjacent to the second side of the core layer, and the second side of the second skin layer is suitable for a surface treatment selected from the group consisting of flame, corona, plasma, metallization, coating, printing, and combinations thereof.
3. The coated film according claim 2 , further comprising: a second coating comprising at least a second filler component and a second binder component, the second coating applied to the second side of the second skin layer, wherein at least one of the second filler component and the second binder component is hydrophobic.
4. The coated film according to claim 3 , wherein the composition of the second coating is identical to the composition of the first coating.
5. The coated film according to claim 3 , wherein the second coating is applied to the film at a weight of from about 0.1 g/m 2 to about 4.0 g/m 2 .
6. The coated film according to claim 3 , wherein the second coating is the same composition as the first coating and wherein the second coating has a surface roughness (Ra) greater than 0.20 μm.
7. The coated film according to claim 1 , wherein the first filler component comprises at least one of: a) a clay material; b) a natural mineral material; c) a surface-treated natural mineral; d) a synthetic mineral; e) a surface-treated synthetic mineral; f) plastic pigments; and g) thermoplastic pigments.
8. The coated film according to claim 1 , wherein the first filler component comprises at least one of: a) a surface-modified clay; b) a surface-modified silica; and c) a surface-modified titanium dioxide.
9. The coated film according to claim 1 , wherein the first filler component comprises a polyolefin.
10. The coated film according to claim 1 , wherein the first filler component comprises polyethylene.
11. The coated film according to claim 1 , wherein the first coating further comprises: at least one of organic particles, inorganic particles, silica gel, anti-static material, wetting agents, surfactants, security taggants, pH modifiers, and buffering agents.
12. The coated film according to claim 1 , wherein the first coating is applied to the film at a weight of from about 0.1 g/m 2 to about 4.0 g/m 2 .
13. The coated film according to claim 1 , wherein the first coating is applied to the film at a weight of from about 0.2 g/m 2 to about 2.5 g/m 2 .
14. The coated film according to claim 1 , wherein the first coating is applied to the film at a weight of from about 0.8 g/m 2 to about 2.0 g/m 2 .
15. The coated film according to claim 1 , wherein the first filler component comprises at least 45 wt % of the first coating.
16. The coated film according to claim 1 , wherein the first filler component comprises at least 60 wt % of the first coating.
17. The coated film according to claim 1 , wherein the first binder is hydrophobic and the first filler material is hydrophilic, the first filler comprising at least one of: a) silica; b) hydrophilic clays; c) barium sulfate; d) calcium carbonate; e) titanium dioxide; f) zinc oxide; g) tin oxide; h) aluminum oxide; i) talc; j) carbon black; and k) another pigment.
18. The coated film according to claim 1 , wherein the first crosslinking agent comprises at least one of zirconium salts of mineral acids, polyfunctional aziridine, zinc salts, zirconium salts, glyoxal, melamine-formaldehyde resins, polyfunctional isocyanates, polyfunctional amino compounds, polyfunctional vinyl compounds, and polyfunctional epoxy compounds.
19. The coated film according to claim 1 , wherein the first coating further comprises at least one of wax emulsions, adhesion promoters, emulsifiers, anti-foams, defoamers, anti-statics, security taggants, co-solvents, wetting aids, and processing aids.
20. The coated film according to claim 2 , further comprising: a first tie layer between the core layer and the first skin layer and optionally a tie layer between the core layer and the second skin layer.
21. The coated film according to claim 1 , wherein the first skin layer comprises a voiding agent selected from the group consisting of polyamides, polybutylene terephthalate, polyesters, acetals, acrylic resins, solid preformed glass particles, hollow preformed glass particles, metal particles, ceramic particles, calcium carbonate, cyclic olefin polymers, cyclic olefin copolymers, silicon dioxide, aluminum silicate, magnesium silicate and mixtures thereof.
22. The coated film according to claim 1 , wherein the core layer comprises a voiding agent selected from the group consisting of polyamides, polybutylene terephthalate, polyesters, acetals, acrylic resins, solid preformed glass particles, hollow preformed glass particles, metal particles, ceramic particles, calcium carbonate, cyclic olefin polymers, cyclic olefin copolymers, silicon dioxide, aluminum silicate, magnesium silicate and mixtures thereof.
23. The coated film according to claim 1 , wherein the polymeric substrate without the first coating has a density of from about 0.30 g/cc to about 0.80 g/cc.
24. The coated film according to claim 1 , wherein the first coating is in the form of a continuous layer on the first side of the first skin layer.
25. The coated film according to claim 1 , wherein the first coating is in the form of a pattern or non-continuous layer on the first side of the first skin layer.