Multilayer flexible packaging material

Abstract

The present invention relates generally to the field of multi-layer flexible packaging materials. In particular, the present invention relates to multi-layer flexible packaging materials for packaging dry foods, preferably confectionery. The packaging materials of the present invention are marine degradable, recyclable and have acceptable barrier properties.

Description

[Technical field]

[0001] The present invention relates generally to the field of multi-layer flexible packaging materials. In particular, the present invention relates to multi-layer flexible packaging materials. The present invention further relates to the use of the multi-layer flexible packaging materials according to the present invention for packaging dry food. [Background technology]

[0002] Plastic packaging is often used in economic activities and people's daily lives. It has several advantages, such as flexibility and light weight. Such light weight contributes, for example, to fuel savings and CO2 reduction during transportation. The barrier properties of plastic packaging help to reduce food waste, as they have a positive effect on extending the shelf life. The barrier properties also help to ensure food safety.

[0003] However, according to the European Strategy for Plastics in a Circular Economy recently published by the European Commission, around 25.8 million tonnes of plastic waste is generated in Europe every year, less than 30% of this waste is recovered for recycling, and as much as 150,000-500,000 tonnes of plastic waste enters the oceans every year.

[0004] There are great efforts in industry and commerce to ensure the reduction of plastic waste. Some supermarkets, for example, have replaced plastic bags with paper-based bags. However, replacing plastic with paper in food packaging is not an easy task. The change in packaging material must not compromise consumer safety. The packaging must not only serve to protect the food, but also be sturdy enough to be handled by machines during the production process and such that the food product can be effectively presented.

[0005] Thus, there is a need for paper-based materials with improved barrier properties, in particular paper-based materials that do not contain plastic layers and have improved barrier properties to allow easier sorting and separation of the paper-based materials during recycling.

[0006] WO 2000 / 076862 in this regard describes a laminate structure for packaging applications comprising a paper substrate and at least one polymer / nanoclay composite layer having a thickness in the range of 0.7 to 9 nanometers and comprising clay particles, applied to the paper substrate.

[0007] However, there is a need in the art to further improve the barrier properties of paper-based packaging materials.

[0008] In particular, in packaging for food products, good barrier properties are essential to maintain the safety and quality of the packaged food. Typically, such barrier properties include gas permeability, such as O2, CO2, and N2 permeability; vapor permeability, such as water vapor permeability; liquid permeability, such as water or oil permeability; aroma permeability; and light permeability.

[0009] Furthermore, against this background of recycling, there is the problem that packaging is not disposed of properly by consumers, i.e., littered. Such materials can end up in the natural environment, particularly problematically in the marine environment. Furthermore, traditional confectionery packaging is small, prone to accidental littering, and the plastic materials used can take years to decompose.

[0010] The present invention therefore seeks to balance the issues of barrier properties, recyclability and marine degradability.

[0011] Any reference to a prior art document in this specification should not be taken as an admission that such prior art is well known or forms part of the common general knowledge in the art.

[0012] [Summary of the Invention] The object of the present invention is to improve upon the current state of the art, in particular to provide a multi-layer flexible packaging material which offers improved barrier properties, can be recycled and is degradable under marine conditions, to provide the use of such a multi-layer flexible packaging material for packaging dry food products, or at least to provide a useful alternative to existing packaging solutions in the art.

[0013] The present inventors have found that the following properties are present in paper-based packaging materials: a polymer layer comprising at least one polymer and optionally a clay barrier material; a barrier layer comprising a metallized material, aluminum oxide, or silicon oxide, or a mixture thereof; A sealant layer; We solve the above problem by applying The polymer layer comprises at least one polymer selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polybutylene succinate (PBS), polybutylene succinate copolymer, polyhydroxyalkanoate (PHA), polylactic acid (PLA), and mixtures thereof.

[0014] The present invention provides water vapor transmission rate (WVTR) and oxygen transmission rate (OTR) test results that meet the requirements for packaging of dry food materials, as well as marine degradability and recycling opportunities. Importantly, no polyethylene (PE) or polypropylene (PP) layers were required to achieve this objective.

[0015] The object of the present invention is therefore achieved by the subject matter of the independent claims. The dependent claims develop the inventive concept further.

[0016] Thus, the present invention provides a multi-layer flexible packaging material comprising a paper layer, an aluminum layer, a nanoclay barrier coating layer, and a sealing layer applied to the surface of the nanoclay barrier coating layer occupying an inner surface of the multi-layer flexible packaging material.

[0017] The present invention further provides the use of the multi-layer flexible packaging material according to the present invention for packaging dry food, preferably confectionery, preferably chocolate products and / or biscuit or wafer products.

[0018] As used herein, the words "comprises," "comprising," and similar words should not be construed in an exclusive or exhaustive sense. In other words, they are intended to mean "including, but not limited to."

[0019] The inventors have shown that by using a multi-layer flexible packaging material according to the present invention, acceptable results in terms of WVTR and OTR can be achieved. Furthermore, as shown in the figures, the present invention provides advantageous properties in terms of marine degradability. [Brief description of the drawings]

[0020] [Figure 1] Shown are the appearances of the reference material cellulose, 2020-31, 2020-32 and 2020-33 (from left to right). [Diagram 2] 1 shows the appearance of the reference article cellulose filter paper after 8 weeks of incubation. [Diagram 3] 1 shows the appearance of test article 2020-31 after 8 weeks of incubation. [Figure 4] 1 shows the appearance of test article 2020-32 after 8 weeks of incubation. [Diagram 5] 1 shows the appearance of test article 2020-33 after 8 weeks of incubation. [Figure 6] FIG. 1 is a schematic diagram of Examples 1 to 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention provides a method for forming a coating from an outer surface to an inner surface, A paper layer; a polymer layer comprising at least one polymer and optionally a clay barrier material; a barrier layer comprising a metallized material, aluminum oxide, or silicon oxide, or a mixture thereof; A sealant layer; A multi-layer flexible packaging material comprising: The present invention relates to a multi-layer flexible packaging material, wherein the polymer layer comprises at least one polymer selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polybutylene succinate (PBS), polybutylene succinate copolymer, polyhydroxyalkanoate (PHA), polylactic acid (PLA), and mixtures thereof.

[0022] In a highly preferred embodiment, the multi-layer flexible barrier material does not include a polyolefin layer, such as a polyethylene (PE), polyethylene terephthalate (PET) or polypropylene (PP) layer. In a preferred embodiment, the term "does not include" means 0% by weight.

[0023] For the purposes of the present invention, a packaging material shall be considered flexible if it is a material that can be bent without breaking. Further, for example, such a flexible material may be a material that can be bent by hand without breaking. Typically, a flexible multi-layer packaging material according to the present invention may have a basis weight of 140 g / m2 or less.

[0024] The packaging material of the present invention is paper-based. One skilled in the art can select an appropriate paper layer based on, for example, the product being packaged, the intended shelf life, and whether the paper material is to be used as a primary, secondary, or tertiary package.

[0025] The present invention includes a barrier layer comprising a metallized material, aluminum oxide or silicon oxide, or a mixture thereof.

[0026] The metallization layer may be applied to the multilayer flexible packaging material by physical vapor deposition. For example, the metallization layer may be applied by a vacuum deposition process. An example of the vacuum deposition process is described in Thin Solid Films, Vol. 666, Nov. 30, 2018, pp. 6-14. Vacuum deposition is an evaporation process in which a metal in a solid phase moves into a gas phase and then back into a solid phase, gradually building up the film thickness. Coatings produced by vacuum deposition have the advantages of good abrasion resistance, impact strength and temperature strength, as well as the ability to deposit on complex surfaces. In a preferred embodiment, the metallization deposits aluminum.

[0027] In the present invention, the deposition method of silicon dioxide film is not limited.Silicon dioxide film can be produced by various methods such as sol-gel, liquid phase deposition, sputtering, chemical vapor deposition (CVD), thermal oxidation, plasma enhanced chemical vapor deposition (PECVD), atmospheric pressure plasma deposition, and physical vapor deposition (PVD).PVD is one of the most established vacuum deposition techniques.PVD includes vacuum deposition, ion plating, and sputtering deposition.These techniques allow for better control of film thickness and ensure that the deposited film has good adhesion performance.

[0028] In the present invention, the deposition method of the aluminum oxide film is not limited. In one embodiment, the aluminum oxide layer may be deposited by vacuum deposition.

[0029] Those skilled in the art can appropriately adjust the thickness of the barrier layer depending on, for example, the intended shelf life, the packaged product, and the total thickness of the packaging material. In the multi-layer flexible packaging material according to the present invention, the barrier layer may have a thickness in the range of, for example, 20 to 500 nm, 30 to 400 nm, or 50 to 200 nm.

[0030] The optical density range of the barrier layer may preferably be in the range of 1.4 to 3.8, which corresponds to a thickness of 30 to 200 nanometers.

[0031] Nanoclay barrier coating layers are known to those skilled in the art. For example, the nanoclay barrier coating layer may be a PVOH-polyacrylic acid-nanoclay barrier coating layer. Examples of such PVOH-polyacrylic acid-nanoclay barriers are commercially available from specialized suppliers. Also, those skilled in the art can formulate such PVOH-polyacrylic acid-nanoclay barriers. Sustainable barrier Coatings in Paper and Board to 2023, a state of art report, Smithers information Ltd. 2018, pages 134-142 summarizes the current state of the art. Typically, such PVOH-polyacrylic acid-nanoclay barriers can be produced, for example, by functionalizing the surface of the nanoclay so that sufficient repulsive forces are obtained to allow the formation of a tortuous path. The nanoclay may be selected from the group consisting of aluminosilicates, such as, for example, montmorillonite (MMT) nanoclay.

[0032] In some applications, it may be preferred if the nanoclay barrier coating layer has a composition comprising polyurethane. Polyurethane may be used to partially or completely replace the PVOH-polyacrylic matrix. Polyurethane has the advantage, for example, of imparting very good chemical resistance, solvent resistance and durability. Thus, the nanoclay barrier coating layer composition may, for example, comprise 1-10 wt.% polyurethane, 2-6 wt.% polyurethane, or 3-5 wt.% polyurethane.

[0033] In some applications it may be preferred if the nanoclay is dispersed in a polyvinylidene dichloride polymer matrix, where the inherent hydrophobic and steric hindrance effects in the PVDC matrix further improve the WVTR barrier properties.

[0034] In a preferred embodiment, the nanoclay is dispersed in a matrix of butenediol-vinyl alcohol copolymer (BVOH), polybutylene succinate (PBS), polybutylene succinate copolymer, polyhydroxyalkanoate (PHA), polylactic acid (PLA), and mixtures thereof.

[0035] In the above embodiments, the nanoclay material is present in the polymer layer in an amount of 0.5-10.0%, 1.0-8.0%, or 1.25-5.0% by weight of the polymer layer.

[0036] In one embodiment, the remainder of the polymer layer is butenediol-vinyl alcohol copolymer (BVOH), polybutylene succinate (PBS), polybutylene succinate copolymer, polyhydroxyalkanoate (PHA), polylactic acid (PLA), and mixtures thereof.

[0037] In a preferred embodiment, the polymer layer comprises a portion comprising nanoclay dispersed in a matrix of butenediol-vinyl alcohol copolymer (BVOH), polybutylene succinate (PBS), polybutylene succinate copolymer, polyhydroxyalkanoate (PHA), polylactic acid (PLA), and mixtures thereof, and a second portion comprising butenediol-vinyl alcohol copolymer (BVOH), polybutylene succinate (PBS), polybutylene succinate copolymer, polyhydroxyalkanoate (PHA), polylactic acid (PLA), and mixtures thereof.

[0038] In a preferred embodiment, the weight ratio of the nanoclay-containing portion to the second portion is 0.1:1.0 to 1.0:0.1, preferably 0.25:1.0 to 1.0:0.25, more preferably 0.5:1.0 to 1.0:0.5, for example 1.0:1.0.

[0039] In a highly preferred embodiment, the polymer layer comprises a first portion of a nanoclay mixture dispersed in a matrix of butenediol-vinyl alcohol copolymer (BVOH) and a second portion of BVOH.

[0040] In a preferred embodiment, the polymer layer comprises BVOH and a nanoclay mixture, with the second portion of BVOH being one layer.

[0041] In a preferred embodiment, the ratio of the first part to the second part is 0.25:1.0 to 1.0:0.25. In a preferred embodiment, the polymer layer has a basis weight (i.e. the total basis weight of both parts) in the range of 1 to 20 g / m2.

[0042] In the present invention, it has been found that the embodiment utilizing BVOH in the polymer layer is most preferred from the standpoint of barrier properties.

[0043] The nature of the sealant is not particularly limited, but in a preferred embodiment, the sealant comprises a material selected from polyesters (e.g., PHA, PBS, PBSA, etc.), cellophane, polyvinyl alcohol and derivatives thereof (e.g., BVOH, PVOH, etc.) and mixtures thereof.

[0044] In a preferred embodiment, the sealant layer comprises at least one material selected from polyhydroxyalkanoates (PHA), polybutylene succinate (PBS), polybutylene succinate copolymers, and mixtures thereof.

[0045] In the present invention, when the term "polybutylene succinate copolymer" is used, it includes copolymers known in the art used in packaging, most preferably poly(butylene succinate-coadipate) (PBSA).

[0046] In a preferred embodiment, the paper layer has a basis weight of 40-130 g / m2, preferably 50-100 g / m2, more preferably 60-100 g / m2 or 55-90 g / m2.

[0047] In a preferred embodiment, the polymer layer has a basis weight in the range of 1 to 20 g / m2, preferably 2 to 15 g / m2, more preferably 3 to 10 g / m2.

[0048] In a preferred embodiment, the sealant layer has a basis weight in the range of 1 to 30 g / m2, preferably 2 to 25 g / m2, more preferably 5 to 15 g / m2.

[0049] In a preferred embodiment, the total basis weight of the packaging is in the range of 42.5 to 150 g / m2, preferably 50 to 125 g / m2, more preferably 60 to 100 g / m2.

[0050] In a preferred embodiment, the paper layer has a basis weight of 60 to 100 g / m2, The polymer layer has a basis weight in the range of 3 to 10 g / m2; the barrier layer comprises a metallization material; The sealant layer has a basis weight in the range of 5 to 15 g / m2.

[0051] The multi-layer flexible packaging material of the present invention may be a food product packaging material. The packaging material may be, for example, a primary packaging material, a secondary packaging material, or a tertiary packaging material. When the multi-layer flexible packaging material is a food product packaging material, the primary food product packaging material may be a food product packaging material that is in direct contact with the actual food product. The secondary food product packaging material may be a food product packaging material that serves to secure one or more food products contained in the primary package. The secondary packaging material is typically used when multiple food products are provided to the consumer in a single container. The tertiary food product packaging material may be a food product packaging material that serves to protect one or more food products contained in the primary package and / or the primary and secondary packages during transportation.

[0052] In a preferred embodiment the packaging is a primary packaging for a food product, preferably a confectionery food product, preferably a chocolate product and / or a biscuit or wafer product.

[0053] In some applications of the present invention, it may be preferred if the paper layer is non-porous. If the paper layer has a porous surface, an additional surface layer covering the porous paper surface may be added to make it air impermeable. Such additional surface layer may comprise or consist of starch, pigment-starch or pigment-latex blends. The ratio of the pore volume to the total volume of a paper material is called the porosity of the paper material. For the purposes of the present invention, a paper layer shall be considered as non-porous if it has a porosity of less than 40%, such as less than 30% or less than 20%, if its Gurley air permeability is less than 20 mL / min (Tappi T547). Thus, in one embodiment of the present invention, the paper layer is a non-porous paper layer.

[0054] It may be preferred that the paper layer has a low surface roughness. For example, the paper layer may have a Bendsten roughness of less than 100 mL / min. Bendsten roughness can be determined according to ISO 8791-2:2013, which is incorporated herein by reference.

[0055] The barrier properties of packaging materials are well known to those skilled in the art.For example, when the packaging material is a packaging material for food products, such good barrier properties are essential to maintain the safety and quality of the packaged food.Typically, such barrier properties include gas permeability, such as O2, CO2 and N2 permeability; vapor permeability, such as water vapor permeability; liquid permeability, such as water or oil permeability; aroma permeability; and light permeability.

[0056] Prior to applying the aluminum layer and / or nanoclay barrier to the paper layer, a primer may be used to improve the bonding of the coating with the paper layer. Primers typically have chemistry that allows the coating to adhere strongly to the primer, which in turn adheres strongly to the paper layer.

[0057] Primers for the purposes of the present invention may be selected from the group consisting of acrylic copolymers, polyesters, polyhydroxyalkanoates, natural and chemically modified starches, xylans and chemically modified xylans, polyvinylidene dichlorides, polyvinyl alcohol, ethyl-vinyl alcohol, vinyl acetate, ethyl-vinyl acetate, cellulose nitrate, polyolefins, silanes, polyurethanes, or combinations thereof.

[0058] One or more primers used for the purpose of the present invention may contain nanoclay. Adding nanoclay to at least one primer has the advantage that the barrier properties of the resulting multi-layer flexible packaging material are improved. Thus, in the multi-layer flexible packaging material according to the present invention, for example, the primer applied to the inner surface of the paper layer may contain nanoclay. This enhances the barrier properties.

[0059] Suitable primers are known to those skilled in the art and can be selected accordingly. The primer applied between the paper layer and the aluminum layer can be, for example, polyurethane. Alternatively, a polyurethane tie layer can be used. The primer applied between the paper layer and the nanoclay barrier coating layer can also be polyurethane.

[0060] To ensure that the aluminum layer is adequately protected against abrasion, for example, the aluminum layer may be protected with a protective layer. Suitable protective layers are well known to those skilled in the art and may be selected from the group consisting of acrylic copolymers, polyesters, polyhydroxyalkanoates, natural and chemically modified starches, xylans and chemically modified xylans, polyvinylidene dichlorides, polyvinyl alcohols, ethyl-vinyl alcohols, vinyl acetates, ethyl-vinyl acetates, cellulose nitrates, polyolefins, silanes, polyurethanes, or combinations thereof. The use of such a protective layer has the advantage that the aluminum layer is stabilized and adequately protected against undesirable influences, maintaining its integrity and thus its positive impact on the barrier properties of the multilayer flexible packaging material of the present invention.

[0061] The multi-layer flexible packaging material according to the present invention comprises a sealing layer.

[0062] Coating paper materials, such as paper packaging materials, with a sealing layer, for example with a polymer dispersion, is well known in the art, for example to improve the barrier properties of the paper materials.Examples are described, for example, in Kimpimaki T., Savolainen AV (1997) Barrier dispersion coating of paper and board.In: Brander J., Thorn I. (eds) Surface Application of Paper Chemicals.Springer, Dordrecht.coated, paper materials.

[0063] For consumer information and design purposes, an ink layer may be applied on top of the paper layer. Again, it may be preferred if a primer is applied between the paper layer and the ink layer. Suitable primers are known to those skilled in the art and may be, for example, a polyurethane primer.

[0064] To provide a high-quality finish to the outer surface of the multi-layer flexible packaging material according to the present invention, an overprint varnish (OPV) can be applied to the surface of the ink layer. OPVs are well known to those skilled in the art and can be selected, for example, according to the intended purpose of the packaging material of the present invention. For example, the OPV can be selected from the group consisting of conventional offset letterpress varnishes, acrylic varnishes, UV varnishes, and gravure varnishes, which are representative of water- or solvent-based polymer formulations.

[0065] Thus, the multi-layer flexible packaging material of the present invention may further comprise a primer applied to the paper layer, an ink layer applied to the primer on the paper layer, and an overprint varnish layer applied to the ink layer.

[0066] As mentioned above, the inventors have surprisingly found that the same satisfactory barrier properties are achieved when both the aluminum layer and the PVOH-polyacrylic acid-nanoclay barrier coating layer are located on the inside of the packaging material facing the packaged product. This allows only the ink layer, optionally with a primer and / or OVP, to be on the outer surface of the packaging material. As a result, the aluminum layer and the PVOH-polyacrylic acid-nanoclay barrier coating layer are well protected from any external influences, for example during transportation, handling and contact with the consumer, so that their integrity is well protected and the barrier properties of the multi-layer flexible packaging material of the present invention are easier to maintain.

[0067] The multi-layer flexible packaging material according to the present invention can have any thickness suitable for the packaging material. Those skilled in the art can determine the appropriate thickness. Typically, however, the packaging material should be as thin as possible while ensuring the safety and shelf life of the food product, especially when the packaging material is intended for use in packaging food products. For example, the multi-layer flexible packaging material according to the present invention can have a total thickness in the range of about 30 to 150 μm, 40 to 120 μm, or 50 to 100 μm.

[0068] Those skilled in the art can appropriately select the basis weight or thickness of the individual components of the multi-layer flexible packaging material according to the present invention.

[0069] In a preferred embodiment of the present invention, the multi-layer flexible packaging material according to the present invention may be recyclable. For example, it may be recyclable in paper and cardboard streams. During recycling, the aluminum layer is separated from the rest of the packaging. Due to the fact that the subject matter of the present invention achieves the omission of polyolefin layers, such as PE or PP layers, the sortability of the packaging material of the present invention during recycling is improved. Typically, aluminum is separated from the rest of the packaging material during recycling in a hydrapulper. Thus, the multi-layer flexible packaging material according to the present invention may be recyclable as paper and / or carton.

[0070] One advantage of the present subject matter is that excellent barrier properties are achieved despite the preferably omission of a polyolefin layer, such as a PE or PP layer.

[0071] The multi-layer flexible packaging material according to the present invention may have a WVTR barrier in the range of 0.1 to 50 g / m2d (38° C., 90% RH).

[0072] Due to these excellent barrier properties, the multi-layer flexible packaging material according to the present invention can be used to package food products. For the purposes of the present invention, the term "food" shall mean any substance intended for human consumption, whether processed, semi-processed or raw, in accordance with the Codex Alimentarius, and includes beverages, chewing gum, and any substance used in the manufacture, preparation or processing of "food", but does not include substances used solely as cosmetics or tobacco or drugs.

[0073] Notably, due to the excellent barrier properties, the multi-layer flexible packaging material according to the present invention can be used to package dry food products. Dry food products include powders and granules, such as powders and granules that are reconstituted with milk or water. Dry food products may have a moisture content of, for example, 5% or less.

[0074] Thus, the multi-layer flexible packaging material according to the invention can be used to package dry food products.The subject matter of the invention also extends to the use of the multi-layer flexible packaging material according to the invention for packaging dry food products.

[0075] A person skilled in the art will understand that all features of the invention disclosed herein can be freely combined. In particular, features described with respect to the product of the invention can be combined with features described with respect to the method of the invention, and vice versa. Furthermore, features described with respect to different embodiments of the invention may be combined.

[0076] Although the invention has been described by way of example, it should be understood that variations and modifications can be made without departing from the scope of the invention as defined in the claims.

[0077] Furthermore, where known equivalents exist for specific features, such equivalents are incorporated as if specifically referred to herein. Further advantages and features of the present invention will be apparent from the figures and non-limiting examples. EXAMPLES

[0078] Examples 1 to 4 The following compositions were prepared using metallization (vacuum deposition-aluminum), dispersion coating for the polymer layer, and extrusion coating for the sealant layer.

[0079] [Table 1]

[0080] Example 5 The following compositions of the present invention were prepared for marine degradability testing. 2020-31:OPV / ink / paper / PHA / metallization / PVOH 2020-32:OPV / ink / paper / BVOH / metallized / PVOH 2020-33:OPV / ink / paper / PHA / AlOx / PVOH

[0081] The disintegration test is carried out in duplicate. At the start, two 2 cm x 2 cm pieces of material are placed in one reactor. Every four weeks, the reactor contents are sieved through a 2.0 mm sieve and the disintegration of the reference and test materials is visually observed.

[0082] Figure 1 shows the appearance of the reference material and test article at the start, and Figures 2-5 show the appearance of the coupons collected in duplicate of the reference and test articles after 8 weeks of incubation at 30°C ± 2°C.

[0083] After 8 weeks of incubation, the disintegration of the cellulose filter paper of the reference article had not progressed significantly except for some degradation at the edges (Figure 2).

[0084] Disintegration of Test Article 2020-31 had progressed so far that only a small portion remained on the 2.0 mm sieve and only a small portion of the top layer was still visible (Figure 3).

[0085] Test Article 2020-32 continued to degrade, with the majority of the fragments already passing through the 2.0 mm sieve (Figure 4).

[0086] Test article 2020-33 continued to show depression after 4 weeks, with generalized fragmentation (Figure 5).

[0087] Example 6 For Examples 1 and 3, g / m at 23° C. 2 The WVTR at 85% RH / day was compared to an 81 gsm commercial single-sided coated glossy paper with a barrier (oxygen, water vapor, grease, mineral oil, and aroma) coating on the backside.

[0088] [Table 2]

[0089] Example 7 One finger of standard KitKat® (a chocolate covered wafer product) was wrapped at speeds of 30 bar / min and 80 bar / min on an automated wrapping line using the paper of Example 3. The bars were wrapped without any issues and no quality defects were observed. The packaging was sealed at 100°-110° and 200N for 0.5 seconds.

[0090] EXOS testing using the Abiss Leak system was performed on six sample bars. Standard is less than 16mL / min. Samples delivered a range of 3.2-4.2mL / min with an average of 3.6mL / min.

[0091] In grease tests where a food-safe lubricant was applied to the inside of the paper, no grease penetration / barrier failure was observed after the grease test.

[0092] Example 8 Example 7 was repeated for the paper of Example 1. Runs were performed at 30 bar / min and 80 bar / min and no quality defects were observed. EXOS values ​​of 2.0 and 3.1 were obtained in two tests and no grease penetration / barrier failure was observed after the grease test.

[0093] Example 9 Additional grease resistance tests were performed on Examples 1-4 packaged with KitKat® 4 Finger products using two cycle times: 6 hours at 25° C. / 50% RH and 6 hours at 40° C. / 50% RH. All Examples gave results indicating a shelf life of at least 6 months, with Examples 1, 3, and 4 having grease stained areas of 0.3% or less in area. Example 3 yielded 0.0% area in two separate tests.

[0094] Examples 10 to 13 The following compositions were prepared using metallization (vacuum deposition-aluminum), dispersion coating for the polymer layer, and extrusion coating for the sealant layer.

[0095] [Table 3]

[0096] The materials were coated with a 10 nm gold layer and evaluated under a microscope at 100x and 1000x magnification.

[0097] The porosity of the material was evaluated and found to be pinhole-free after coating.

[0098] Examples 10 and 12 were found to have a more uniform coating with lower levels of visible particulates, supporting the finding that the BVOH coating provides the most effective barrier properties within the scope of the present invention.

[0099] The recyclability was evaluated by ProPakma GmbH using the fiber yield and was found to have an acceptable recyclability level.

[0100] Relative WVTR at 90% RH, 38° C. and 65% RH, 22° C. was evaluated and it was confirmed that Examples 10 and 12 were superior to Examples 11 and 14.

Claims

1. From the outer surface to the inner surface, A paper layer; a polymer layer comprising at least one polymer and optionally a clay barrier material; a barrier layer comprising a metallized material, aluminum oxide, or silicon oxide, or a mixture thereof; A sealant layer; A multi-layer flexible packaging material comprising: The multi-layer flexible packaging material, wherein the polymer layer comprises at least one polymer selected from the group consisting of butenediol-vinyl alcohol copolymer (BVOH), polybutylene succinate (PBS), polybutylene succinate copolymer, polyhydroxyalkanoate (PHA), polylactic acid (PLA), and mixtures thereof.

2. The multi-layer flexible packaging material of claim 1 , wherein an ink is applied to an outer surface of the paper layer.

3. 10. The multi-layer flexible packaging material of claim 1, wherein the polymer layer comprises a mixture of polybutylene succinate (PBS) or a polybutylene succinate copolymer and a polyhydroxyalkanoate.

4. 10. The multi-layer flexible packaging material of claim 1, wherein the polymer layer comprises butenediol-vinyl alcohol copolymer (BVOH) and clay.

5. 2. The multi-layer flexible packaging material according to claim 1, wherein the paper layer has a basis weight of 40 to 130 g / m2.

6. The multi-layer flexible packaging material of claim 1, wherein the polymer layer has a basis weight in the range of 1 to 20 g / m2.

7. The multi-layer flexible packaging material of claim 1, wherein the sealant layer has a basis weight in the range of 1 to 30 g / m2.

8. 2. The multi-layer flexible packaging material according to claim 1, wherein the total basis weight of the multi-layer flexible packaging material is in the range of 42.5 to 150 g / m2.

9. The multi-layer flexible packaging material of claim 1, wherein the barrier layer has a thickness in the range of 20 to 500 nm.

10. The multi-layer flexible packaging material of claim 1, wherein the multi-layer flexible packaging material has a total thickness in the range of 30 to 150 μm.

11. The paper layer has a basis weight of 60 to 100 g / m2, the polymer layer has a basis weight in the range of 3 to 10 g / m2; the barrier layer comprises a metallization material; and The sealant layer has a basis weight in the range of 5 to 15 g / m2. The multi-layer flexible packaging material of claim 1.

12. 10. The multi-layer flexible packaging material of claim 1, wherein the multi-layer flexible packaging material comprises an aluminum metallized layer, the polymer layer comprises a mixture of BVOH and nanoclay, and also comprises a BVOH layer.

13. Use of the multi-layer flexible packaging material according to any one of claims 1 to 12 for packaging dry food products.

14. A dry food product packaged in the multi-layer flexible packaging material according to any one of claims 1 to 12.

15. The dried food product of claim 14 which is a confectionery product.

16. The dry food product of claim 15, wherein the confectionery product is a product comprising chocolate and / or wafers.

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