MULTILAYERED ARTICLES

Abstract

Provided is highly stable and versatile multilayered structure or articles, based on cellulose nanomaterials, tailored and processed for a variety of applications, as superior materials in the food packaging industry.

Claims

1. An article in the form of a multilayered structure comprising three or more material layers, at least one of said three or more material layers is a substrate layer and at least one another of said three of more material layers is a layer of a blend of cellulose nanocrystals (CNC) and polyvinyl alcohol (PVOH).

2. The article according to claim 1, characterized by one of more of the following: (1) a grease barrier of 12, as determined using TAPPI T 559 standard; (2) an oxygen transmittance rate (OTR) of between 0.01 and 15 cc/m2-day, when measured at 80% relative humidity (RH), at 23 C.; and/or (3) a water vapor transmittance rate (WVTR) of between 0.01 and 20 gr/m2-day, when measured at 90% RH, at 38 C.

3. The article according to claim 2, wherein the OTR is between 0.01 and 1 cc/m2-day, when measured at 80% relative humidity (RH), at 23 C.; or wherein the OTR is between 0.01 and 5 cc/m.sup.2-day, when measured at 80% relative humidity (RH), at 23 C.; or wherein the OTR is between 1 and 10 cc/m.sup.2-day, when measured at 80% relative humidity (RH), at 23 C.; or wherein the OTR is between 1 and 5 cc/m.sup.2-day, when measured at 80% relative humidity (RH), at 23 C.; or wherein the OTR is below 1 cc/m.sup.2-day, when measured at 80% relative humidity (RH), at 23 C.

4.-7. (canceled)

8. The article according to claim 2, wherein the WVTR is between 0.01 and 1 gr/m2-day, when measured at 90% RH, at 38 C.; or wherein the WVTR is between 0.01 and 5 gr/m.sup.2-day, when measured at 90% RH, at 38 C.; or wherein the WVTR is between 1 and 10 gr/m.sup.2-day, when measured at 90% RH, at 38 C.; or wherein the WVTR is between 1 and 5 gr/m.sup.2-day, when measured at 90% RH, at 38 C.; or wherein the WVTR is between 5 and 10 gr/m.sup.2-day, when measured at 90% RH, at 38 C.; or wherein the WVTR is below 1 gr/m.sup.2-day, when measured at 90% RH, at 38 C.

9.-13. (canceled)

14. The article according to claim 1, being biodegradable.

15. The article according to claim 1, wherein the blend of CNC and PVOH is a mixture of CNC and PVOH at a ratio between 0.001:1 to 1:0.001 (CNC to PVOH).

16. (canceled)

17. The article according to claim 1, consisting of between 3 and 7 material layers, the multilayered structure being of the form ABC, wherein each of A, B and C designate a single layer or two or more layers of a material: Layer A is a substrate comprising a material selected from a polymeric material, a paper or paper-based material, a polymer coated paper-based material, a nanocellulose film, nanocellulose/polymer film, a fabric material, a porous material, a membrane material, a mineral material, and a varnish; Layer B is a layer of CNC-PVOH blend, optionally comprising at least one additional material; and Layer C is a cover layer comprising a material selected from a polymeric material, a paper or paper-based material, a polymer coated paper-based material, a nanocellulose film, nanocellulose/polymer film, a fabric material, a porous material, a membrane material, a mineral material, and a varnish.

18. The article according to claim 17, wherein said layer of CNC-PVOH blend further comprises at least one additional material selected from polyvinyl acetate (PVAc), ethylene vinyl alcohol (EVOH), polyvinyl pyrrolidone (PVP), starch, chitosan, poly acrylic acid (PAA), polyethyleneimine (PEI), carbohydrates, ethylene vinyl acetate (EVA), elastomers, isocyanates, polyurethanes and inert fillers.

19. The article according to claim 1, wherein said layer of CNC-PVOH blend consists CNC and PVOH.

20. The article according to claim 17, wherein in a structure ABC, layer B comprises a layer of CNC-PVOH blend and a layer of a cellulose nanomaterial selected from nanocrystals (CNC), microfibrillated cellulose (MFC), a combination of CNC and NFC, a combination of CNC and MFC, a blend of CNC with at least one water soluble or water dispersible additive, and a blend of CNC with one or more additional materials selected from polyvinyl alcohol (PVOH), polyvinyl acetate (PVAc), ethylene vinyl alcohol (EVOH), polyvinyl pyrrolidone (PVP), starch, chitosan, poly acrylic acid (PAA), polyethyleneimine (PEI), carbohydrates, ethylene vinyl acetate (EVA), elastomers, isocyanates, polyurethanes and inert fillers.

21. The article according to claim 1, wherein any of the material layers comprises at least one additive selected from a polymer, a plasticizer, a surfactant, a particulate material, a pigment, a carbohydrate, a salt, a conductive material, an oxygen scavenger, lignin and natural extracts.

22. (canceled)

23. The article according to claim 1, the article consisting a layer of a blend consisting of CNC and PVOH; a substrate layer and a cover layer.

24. The article according to claim 17, wherein each of layer A and layer C is a paper or paper-based material.

25. The article according to claim 17, wherein each of layer A and layer C is of a polymeric material, a polymer coated paper-based material, or a nanocellulose/polymer film.

26. (canceled)

27. The article according to claim 17, wherein each of layers A and C is of a material selected, independently of the other, from polyethylene, polypropylene, polyester, polyvinyl alcohol, ethylene vinyl alcohol, polyamide, polystyrene, polylactic acid, polyhydroxyalkanote, polycaprolactone, polyhydroxybutyrate, polyvinyl acetate, polyacrylonitrile, polybutylene succinate, polyvinylidene chloride, starch, cellulose, polyhydroxyvalerate, polyhydroxyhexanoate, polyanhydrides, polyethylene terephthalate, polyvinyl chloride and polycarbonate.

28. The article according to claim 17, wherein one or both of layers A and C is a polymer coated paperboard, wherein the polymer is selected from polyethylene, polypropylene, polyester, polyvinyl alcohol, ethylene vinyl alcohol, polyamide, polystyrene, polylactic acid, polyhydroxyalkanote, polycaprolactone, polyhydroxybutyrate, polyvinyl acetate, polyacrylonitrile, polybutylene succinate, polyvinylidene chloride, starch, cellulose, polyhydroxyvalerate, polyhydroxyhexanoate, polyanhydrides, polyethylene terephthalate, polyvinyl chloride and polycarbonate.

29. The article according to claim 17, wherein each of layers A and C is of a biodegradable material selected, independently of the other, from polyvinyl alcohol, polylactic acid, polyhydroxyalkanote, polycaprolactone, polyhydroxybutyrate, polyvinyl acetate, polybutylene succinate, starch, cellulose, polyhydroxyvalerate, polyhydroxyhexanoate, polyanhydrides, or any polymer blend of two or more of the aforementioned polymers.

30. The article according to claim 17, wherein one or both of layers A and C is a biodegradable polymer coated paperboard, wherein the biodegradable polymer is selected from polyvinyl alcohol, polylactic acid, polyhydroxyalkanote, polycaprolactone, polyhydroxybutyrate, polyvinyl acetate, polybutylene succinate, starch, cellulose, polyhydroxyvalerate, polyhydroxyhexanoate, polyanhydrides, or any polymer blend of two or more of the aforementioned polymers.

31. (canceled)

32. The article according to claim 17, wherein layers A and B and/or layers B and C are associated with each other directly or separated by an interface material selected from primer material and an adhesive material.

33.-35. (canceled)

36. The article according to claim 1, selected from an article comprising 3 layers: a substrate of a paper or paper based material, a layer of CNC-PVOH blend and a layer of a polymeric water vapor barrier material; an article comprising 5 layers: a layer of a polyolefin, a layer of a paper or paper-based material, a layer of CNC-PVOH blend, a layer of a polymeric water vapor barrier material and a further layer of a polyolefin; an article comprising 4 layers: a layer of a polyolefin, a layer of a paper or paper-based material, a layer of CNC-PVOH blend and a further layer of a polyolefin; an article comprising 3 layers: a paperboard a layer of CNC-PVOH blend and a layer of a polymeric water vapor barrier material; an article comprising 4 layers: a layer of a polyolefin, a paperboard, a layer of CNC-PVOH blend and a further layer of a polyolefin; an article comprising 5 layers: a layer of a polyolefin, a paperboard, a second layer of a polyolefin, a layer of CNC-PVOH blend and a further layer of a polyolefin; an article comprising 3 layers: a layer of a polyolefin, a layer of CNC-PVOH blend and a layer of a polymeric water vapor barrier material; an article comprising 3 layers: a layer of a polyolefin, a layer of CNC-PVOH blend and a further layer of a polyolefin; an article comprising 3 layers: a layer of a biodegradable plastic material, a layer of CNC-PVOH blend and a layer of a polymeric water vapor barrier material; an article comprising 3 layers: a layer of a biodegradable plastic material, a layer of CNC-PVOH blend and a further layer of a biodegradable plastic material; an article comprising 3 layers: a paperboard, a layer of CNC-PVOH blend and a layer of a biodegradable plastic; an article comprising 4 layers: a layer of a biodegradable plastic, paperboard, a layer of CNC-PVOH blend and a further layer of a biodegradable plastic; and an article comprising 5 layers: a layer of a biodegradable plastic, paperboard, a second layer of a biodegradable plastic, a layer of CNC-PVOH blend and a further layer of a biodegradable plastic.

37.-56. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0297] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0298] FIG. 1 depicts an exemplary multilayered structure according to the invention.

[0299] FIG. 2 depicts another exemplary multilayered structure according to the invention.

[0300] FIGS. 3A-D depict different embodiments of another exemplary multilayered structure according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0301] In addition to the examples provided above, the following examples should be considered.

EXAMPLE 1

A 3-Layered Structure

[0302] Layer A: low density polyethylene (LDPE)20 m, treated with Corona

[0303] Layer B: a layer of PVOH/CNC5 g/m.sup.2

[0304] Layer C: low density polyethylene (LDPE)20 m, treated with Corona and coated on the treated side with an adhesive

[0305] The multilayer includes Layer A/Layer B/Layer C

[0306] Preparation Method: [0307] 1. LDPE film (Layer A) was surface treated with corona; [0308] 2. PVOH/CNC water suspension was coated on the treated surface of the LDPE, followed by complete drying (Layer B); [0309] 3. Corona treated LDPE film coated with an adhesive layer and laminated to Layer B, with the adhesive coated side facing the PVOH/CNC layer (Layer C).

[0310] The multilayer structure was transparent, flexible and could be further laminated to include additional layers for the production of flexible or rigid packages with good barrier capabilities. The LDPE layers provided water, water vapor and oil barrier capabilities. The PVOH/CNC inner layer provided gas barrier capabilities.

EXAMPLE 2

A Multilayer Structure (3 Layers)

[0311] Layer A: polypropylene30 m, coated with a hot-melt adhesive (e.g. ethylene vinyl acetate) layer

[0312] Layer B: a layer of PVOH/CNC5 g/m.sup.2

[0313] Layer C: polypropylene30 m, coated with a hot-melt adhesive (e.g. ethylene vinyl acetate) layer

[0314] The multilayer includes Layer A/Layer B/Layer C

[0315] Preparation Method: [0316] 1. Polypropylene film (Layer A) is coated with a hot-melt adhesive (e.g. ethylene vinyl acetate) [0317] 2. PVOH/CNC water suspension is coated on the hot-melt layer, followed by complete drying (Layer B) [0318] 3. Polypropylene film, coated with a hot-melt layer is laminated to Layer B, with the adhesive coated side facing the PVOH/CNC layer (Layer C)

[0319] The multilayer structure is transparent, flexible, and can be further laminated to more layers for the production of flexible or rigid packages with good barrier capabilities. The Polypropylene layers give water, water vapor and oil barrier capabilities. The PVOH/CNC inner layer gives gas barrier capabilities and improves mechanical properties.

[0320] Mechanical properties of the layered structures described in Example 2 were tested by tensile tests, using an Instron machine: [0321] Elastic modulus is improved by 40%-125% compared to reference of layers A and C laminated together. [0322] Elongation at break is improved by 7-20% compared to reference of layers A and C laminated together.

EXAMPLE 3

A 5-Layer Structure

[0323] Layer A1: low density polyethylene (LDPE)20 m

[0324] Layer A2: paperboard, coated with LDPE

[0325] Layer A3: low density polyethylene (LDPE)15 m, treated with corona

[0326] Layer B: a layer of PVOH/CNC4 g/m.sup.2

[0327] Layer C1: low density polyethylene (LDPE)15 m, treated with corona

[0328] Layer C2: low density polyethylene (LDPE)

[0329] The multilayer includes Layer A1/Layer A2/Layer B/Layer C1/Layer C2

[0330] Preparation Method: [0331] 1. LDPE film (Layer A3) was surface treated with corona:, [0332] 2. PVOH/CNC water suspension was coated on the treated surface of the LDPE, followed by complete drying (Layer B); [0333] 3. Corona treated LDPE film was laminated to Layer B, with the corona treated side facing the PVOH/CNC layer (Layer C1); [0334] 4. LDPE was extruded onto the surface of a paperboard (layer A2); [0335] 5. LDPE was extruded from the other side of the paperboard (layer A1); [0336] 6. The multilayer of layers A3/B/C1 was laminated to Layer A2; [0337] 7. LDPE was extruded onto Layer C1 (layer C2).

[0338] This multilayer structure may be used for rigid packages. The paperboard layer gave mechanical stability, the LDPE layers gave water, water vapor and oil barrier capabilities. The PVOH/CNC inner layer gave gas barrier capabilities: [0339] This structure with Layer B having a barrier layer of 1.2 g/m.sup.2had OTR4 at 80% RH [0340] This structure with Layer B having a barrier layer of 2.4 g/m.sup.2had OTR2 at 80% RH [0341] This structure with Layer B having a barrier layer of 4 g/m.sup.2had OTR1 at 80% RH [0342] This structure with Layer B having a barrier layer of 5 g/m.sup.2had OTR<1 at 80% RH.