Recyclable paper barrier laminate

Abstract

The invention provides a recyclable paper laminate comprising a water dispersible barrier that prevents any penetration.

Description

TECHNICAL FIELD

[0001] The present invention relates to a recyclable paper barrier laminate for flexible packaging applications or product delivery systems such as pouches, bags, packs, the recyclable paper barrier laminate comprising recyclable paper combined with a water-soluble lamination layer, a water-dispersible barrier layer, and a water-soluble sealing layer, the recyclable paper barrier laminate providing several advantages compared to prior art paper-based flexible packaging; and to a method for producing a recyclable paper barrier laminate. BACKGROUND

[0002] Paper-based packaging is increasingly popular with consumers as it is perceived to be more natural, more recyclable, and biodegradable. However, uncoated paper has poor barrier properties and attempts to improve barrier properties by adding a coating often result in reduced recyclability in commercial paper recycling systems and also reduce its ability to biodegrade in various environments.

[0003] Uncoated paper-based packaging is very easily recyclable in commercial paper recycling systems and is typically highly biodegradable in certain environments. However, paper with no coating or adhesive at all cannot easily be formed into a complete functional package. Also, uncoated paper-based packaging can only be used to contain dry products that do not require any type of water / moisture or gas or aroma or grease barrier. If the dry product is sensitive to moisture, it will be damaged as moisture will quickly enter the package. If it is sensitive to oxygen, it will oxidize. If the product is greasy, the grease will migrate through the paper and leave unsightly stains on the outside of the package. If the product contains an aroma, the aroma will escape from the package and alter the nature of the product’s intended aroma. However, if a coating is added to the paper to improve barrier properties and / or make it sealable, great care must be taken to avoid adversely affecting the recyclability of the package in commercial paper recycling systems. Furthermore, in the event of improper disposal, it is desirable that the coating does not affect the ability of the entire package to biodegrade within the range of most desirable environmental conditions. Failure to degrade can have adverse environmental impacts such as the persistence of microplastics in sea water.

[0004] A common approach to address the poor barrier properties of paper and make it sealable is to add a polyethylene-based or ethylene copolymer-based or other non-biodegradable polymer coating to the surface of the paper by coating, printing or lamination. However, if the polyethylene coating is too thick, it will adversely affect the recyclability of the paper laminate in typical commercial paper recycling systems. There are many examples of polyethylene coatings that have caused problems in paper recycling processes, especially when using thicker coatings to enhance seal strength and / or enhance barrier properties. Examples of such problems are, but not limited to: i) coating that clogs filters in repulping tanks and systems; ii) coating that tightly holds onto paper fibers and prevents a high percentage of paper fibers from being released into the water of the repulping system; iii) coating that ends up in the recycled paper and adversely affects the appearance or performance of the resulting recycled paper.

[0005] If such a polyethylene coating is made very thin, in a situation where it can be peeled off and sent to a landfill or burned to provide fuel to the plant, leaving the paper fibers to be collected and recycled into paper, the overall structure can be considered recyclable in the paper recycling stream. However, such a structure still has several drawbacks because if it is improperly disposed of in the environment, the paper will biodegrade, but the polyethylene coating will not. This will instead form a persistent microplastic that has a negative impact on the environment, becoming a non-nutritive food source for some animals. In addition, many consumers can notice the appearance of a shiny polyethylene layer on the inner surface of the paper laminate and negatively view it as a non-natural material.

[0006] If, on the contrary, biodegradable materials are used to replace polyethylene, it is well known that biodegradable materials have poor barrier properties to moisture. Such biodegradable coatings must be very thick, causing problems in the paper recycling process.

[0007] Therefore, there is an unmet need for a paper laminate for flexible packaging applications that has a moisture barrier and a sealant layer, has improved recyclability in industrial paper repulping systems, and has reduced environmental impact such as impact on soil and aquatic environments. SUMMARY

[0008] A paper barrier laminate that is capable of being recycled in industrial paper recycling facilities, suitable for home or industrial composting facilities, and biodegradable when improperly disposed in the environment. The laminate is made from the following layers: a recyclable paper layer having an outer surface and an inner surface; a first water-soluble polymer layer having an outer surface and an inner surface, the outer surface disposed on the inner surface of the paper layer; a water-dispersible barrier layer having an outer surface and an inner surface, the outer surface disposed on the inner surface of the water-soluble polymer layer; a second water-soluble polymer layer having an outer surface and an inner surface, the outer surface disposed on the inner surface of the water-dispersible barrier layer.

[0009] A first method of making a recyclable paper barrier laminate includes the steps of: applying a first aqueous solution of a water-soluble polymer composition to a surface of a removable flat carrier such as a PET film or steel belt; removing water from the first aqueous solution of the water-soluble polymer composition to obtain a first water-soluble polymer layer; applying an aqueous dispersion of hydrophilic nanoplatelets to an outer surface of the first water-soluble polymer layer; removing water from the aqueous dispersion of hydrophilic nanoplatelets to obtain a water-dispersible barrier layer; applying a second aqueous solution of a water-soluble polymer composition to a surface of a recyclable paper layer, the paper layer preferably being mechanically polished and / or sized to avoid wet swell issues; joining an outer surface of the water-dispersible barrier layer with the second aqueous solution of the water-soluble polymer composition; removing water from the second aqueous solution of the water-soluble polymer composition to obtain a second water-soluble polymer layer; removing the flat carrier from the resulting recyclable paper barrier laminate.

[0010] A second method of making a recyclable paper barrier laminate includes the steps of: applying a first aqueous solution of a water-soluble polymer composition to an inner surface of a recyclable paper layer, the paper layer preferably being mechanically polished and / or sized to avoid wet swell issues; removing water from the first aqueous solution of the water-soluble polymer composition to obtain a first water-soluble polymer layer; applying an aqueous dispersion of hydrophilic nanoplatelets to an inner surface of the first water-soluble polymer layer; removing water from the aqueous dispersion of hydrophilic nanoplatelets to obtain a water-dispersible barrier layer; applying a second aqueous solution of a water-soluble polymer composition to an inner surface of the recyclable paper layer; removing water from the second aqueous solution of the water-soluble polymer composition to obtain a second water-soluble polymer layer; BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 A cross-section of a recyclable paper layer 10 is shown.

[0012] Figure 2 A cross-section of a first water-soluble polymer layer 20 coated on a recyclable paper layer 10 is shown.

[0013] Figure 3A cross-section of a water-dispersible barrier layer 30 coated on a first water-soluble polymer layer 20 is shown, the first water-soluble polymer layer 20 coated on a recyclable paper layer 10.

[0014] Figure 4 A cross-section of one embodiment of a recyclable paper barrier laminate according to the present application is shown, the laminate comprising a second water-soluble polymer layer 40 coated on a water-dispersible barrier layer 30, the water-dispersible barrier layer 30 coated on a first water-soluble polymer layer 20, the first water-soluble polymer layer 20 coated on a recyclable paper layer 10.

[0015] Figure 5 A schematic of a method of making a recyclable paper barrier laminate according to the present application is shown.

[0016] Figure 6 A cross-sectional image of one embodiment of a recyclable paper barrier laminate obtained via scanning electron microscopy combined with energy dispersive spectroscopy is shown.

[0017] Figure 7 A schematic of an application of a recyclable paper barrier laminate is shown. DETAILED DESCRIPTION

[0018] The present application describes a recyclable paper barrier laminate that provides several advantages compared to prior art paper barrier laminates, and a method of making a recyclable paper barrier laminate.

[0019] As used herein, the term "water vapor transmission rate" or "WVTR" refers to the rate at which water vapor is transmitted through a film when measured according to the water vapor transmission test method set forth in the Test Methods section.

[0020] As used herein, the term "dissolution time" refers to the time required for a water-soluble film, such as a film made from polyvinyl alcohol, to dissolve when measured according to the dissolution test method set forth in the Test Methods section.

[0021] As used herein, the term "water-dispersible" means to break up into small pieces less than 1 millimeter in water. These pieces can, but need not, be stably suspended in water.

[0022] As used herein, the term "copolymer" refers to a polymer formed from two or more types of monomer repeat units. As used herein, the term "copolymer" also encompasses terpolymers, such as terpolymers having a distribution of vinyl alcohol monomer units, vinyl acetate monomer units, and possibly butylenediol monomer units; however, if the copolymer is substantially completely hydrolyzed, the vinyl acetate monomer units can be substantially absent.

[0023] As used herein, the term "hydrolysis degree" refers to the mole percentage of vinyl acetate units converted to vinyl alcohol units when polyvinyl alcohol is hydrolyzed.

[0024] As used herein, when the term "about" modifies a particular value, the term refers to a range of plus or minus twenty percent (+ / - 20%) of the particular value. For any of the embodiments disclosed herein, in various alternative embodiments, any disclosure of a particular value also

[0025] As used herein, when the term "approximately" modifies a particular value, the term refers to a range of plus or minus fifteen percent (+ / - 15%) of the particular value. For any of the embodiments disclosed herein, in various alternative embodiments, any disclosure of a particular value also

[0026] As used herein, when the term "substantially" modifies a particular value, the term refers to a range of plus or minus ten percent (+ / - 10%) of the particular value. For any of the embodiments disclosed herein, in various alternative embodiments, any disclosure of a particular value also

[0027] As used herein, when the term "nearly" modifies a particular value, the term refers to a range of plus or minus five percent (+ / - 5%) of the particular value. For any of the embodiments disclosed herein, in various alternative embodiments, any disclosure of a particular value also

[0028] Figure 1 A cross-section of the recyclable paper layer 10 is shown. The recyclable paper layer 10 has a first surface 12 and a second surface 14 opposite the first surface 12, a thickness 116 between the surfaces 12 and 14, and a grammage obtained from the thickness 116 and the paper density.

[0029] The recyclable paper layer 10 can have a grammage in a range from about 20 g / m2 2 to about 200 g / m2 2 , preferably from about 40 g / m2 2 to about 120 g / m2 2 , more preferably from about 50 g / m2 2 to about 100 g / m2 2 , and more preferably from about 60 g / m2 2 to 85 g / m2 2 .

[0030] Figure 2 A cross-section of the first water-soluble polymer layer 20 is shown, the first water-soluble polymer layer 20 having a first surface 22 and a second surface 24 opposite the first surface 22, and a thickness 216 between the first surface 22 and the second surface 24, the first water-soluble polymer layer 20 being applied to substantially cover at least one of the first surface 12 or the second surface 14 of the recyclable paper layer 10.

[0031] The thickness 216 of the first water-soluble polymer layer 20 can be in the range from about 1 pm to about 120 pm, preferably from about 1 pm to about 25 pm, more preferably from about 1 pm to about 10 pm, even more preferably between 1 pm to about 5 pm.

[0032] The first water-soluble polymer layer 20 comprises at least one water-soluble polymer. Depending on the application, the water-soluble polymer can be selected among available options to dissolve in water within seconds or minutes or hours at a temperature of 23 °C. A polymer that requires more than 24 hours to dissolve in water at a temperature of 23 °C will not be considered water-soluble.

[0033] Figure 3 A cross-section of the water-dispersible barrier layer 30 is shown, the water- dispersible barrier layer 30 having a first surface 32 and a second surface 34 opposite the first surface 32, and a thickness 316 between the first surface 32 and the second surface 34, the water-dispersible barrier layer 30 being applied to substantially cover at least one of the first surface 22 or the second surface 24 of the first water-soluble polymer layer 20.

[0034] The thickness of the water-dispersible barrier layer 30 is in the range from about 0.1 pm to about 20 pm, preferably from about 0.1 pm to about 10 pm, more preferably from about 0.1 pm to about 5 pm.

[0035] The water-dispersible barrier layer 30 comprises 90% to 100% of nanosheets, more preferably 96% to 100% of nanosheets, even more preferably 99% to 100% of nanosheets, such as sodium cloisite or sodium hectorite, and is essentially free of other materials, such as binders, dispersants, surfactants or water-soluble polymers, in the voids between the assembled nanosheets. This means that the cohesion of the nanosheet layer is provided only by the interactions between the nanosheet layers and the adhesion to the water-soluble polymer layer is provided only by the interactions between the nanosheet layers and the water-soluble polymer. The absence of binders (interstitial materials) in the nanosheet layer maximizes the barrier properties of the nanosheet layer to water penetration while maintaining the dispersibility of the hydrophilic nanosheet layer in water once the top / bottom water-soluble polymer layer is removed via dissolution in water during use. Nanosheets that require more than 24 hours to disperse in water at a temperature of 23°C would not be considered water-dispersible.

[0036] Nanosheets are platelet-shaped nanoparticles characterized by a high aspect ratio between diameter and orthogonal height. The high aspect ratio enables the formation of a "brick wall" where the nanosheets are placed parallel to the surface of the underlying water-soluble polymer layer, overlapping each other and stacked on top of each other, thus significantly reducing the migration of molecules, whether gas or liquid, through the nanosheet layer. The higher the aspect ratio, the higher the barrier properties that can be obtained. Typical aspect ratios for exfoliated nanosheets of montmorillonite are about 100 or greater (Cadène et al., JCIS 285(2):719-30, June 2005).

[0037] The water-dispersible barrier layer 30 according to the present application can be optically opaque, preferably translucent, even more preferably transparent, depending on the nanosheet material (exfoliation level, impurity level) and the nanosheet application method.

[0038] Preferably, the water dispersible barrier layer 30 is slightly flexible. When converting paper structures through production lines for printing, sheeting, slitting, rewinding, and other typical converting operations, or when manufacturing articles including the recyclable paper barrier laminate such as bags, the entire recyclable paper barrier laminate structure is often folded, bent, and sometimes slightly stretched. This can cause some of the barrier layers to break, thereby possibly reducing their performance as barrier layers. Therefore, it is preferred that the water dispersible barrier layer 30 is slightly flexible and can be stretched without breaking as the rest of the structure is stretched. Preferably, the water dispersible barrier layer 30 can elongate at least 1%, at least 2%, at least 5% as the underlying paper layer and water soluble polymer layer stretch. In some cases, it can be desirable for the barrier layer to stretch as much as 10% or even as much as 20% without breaking. In one embodiment, this is achieved by dividing the water dispersible barrier layer into a plurality of different water dispersible barrier sub-layers separated by a plurality of different water soluble polymer sub-layers.

[0039] Figure 4 A cross-section of a recyclable paper barrier laminate including a recyclable paper layer 10 having a first surface 12 and a second surface 14 opposite the first surface 12 and a thickness 116 between the first surface 12 and the second surface 14 is shown. Attached to the recyclable paper layer is a first water soluble polymer layer 20 having a first surface 22 and a second surface 24 opposite the first surface 22 and a thickness 216 between the first surface 22 and the second surface 24 and substantially covering at least one of the first surface 12 or the second surface 14 of the paper layer 10. Attached to the first water soluble polymer layer is a water dispersible barrier layer 30 having a first surface 32 and a second surface 34 opposite the first surface 32 and a thickness 316 between the first surface 32 and the second surface 34 and substantially covering the second surface 24 of the first water soluble polymer layer 20. Attached to the water dispersible barrier layer is a second water soluble polymer layer having a first surface 42 and a second surface 44 opposite the first surface 42 and a thickness 416 between the first surface 42 and the second surface 44 and substantially covering the surface 32 of the water dispersible barrier layer 30. Adhesion between the layers is provided by the interaction between the water soluble polymer and the hydrophilic nanoplatelets.

[0040] The thickness of the second water soluble polymer layer 40 between the first surface 42 and the second surface 44 can range from about 1 pm to about 1000 pm, preferably from about 1 pm to about 200 pm, more preferably from about 1 pm to about 40 pm.

[0041] The second water-soluble polymer layer 40 comprises at least one water-soluble polymer. Depending on the application, the water-soluble polymer can be chosen among the available options to dissolve in water within seconds or minutes or hours at a temperature of 23°C. A polymer that requires more than 24 hours to dissolve in water at a temperature of 23°C will not be considered water-soluble.

[0042] Each layer according to the present invention is distinct and separated from each other. By distinct is meant that the water-dispersible barrier layer 30 within the first water-soluble polymer layer 20 and the second water-soluble polymer layer 40 essentially comprises nanosheets only, and the border between the water-dispersible barrier layer 30 and the surrounding first water-soluble polymer layer 20 and second water-soluble polymer layer 40 is distinguished by a large composition change over a small distance, thereby forming a sharp border easily seen by microscopy techniques known in the art. The border layer, i.e. the intermediate layer of intermediate composition between the water-dispersible nanosheet layer and the adjacent water-soluble polymer layer, is not more than 2 pm thick, as seen by microscopy techniques known in the art.

[0043] Figure 6 A cross-sectional image of a recyclable paper barrier laminate consisting of a recyclable paper layer coated with a first water-soluble polyvinyl alcohol layer, a water-dispersible Corosalt barrier layer, and a second water-soluble polyvinyl alcohol layer is shown, obtained via scanning electron microscopy (SEM). The second water-soluble polyvinyl alcohol layer is less visible than the first water-soluble polyvinyl alcohol layer because it is much thinner. EDX color coding helps to emphasize the chemical differences of the layers.

[0044] When the recyclable paper barrier laminate according to the present invention is immersed in water (e.g. the paper recycling process if the waste is managed, or the aqueous environment if the waste is improperly discarded), the water-soluble polymer layers will dissolve and their components are consumed in the water treatment plant (if recycled) or in the aqueous environment (river, sea) if improperly discarded. Immersed in water without the surrounding and supporting water-soluble polymer layers, the water-dispersible barrier layer will break and, in the case of graphene or graphene oxide, the nanosheets will be consumed as organic carbon, or in the case of natural clay or mica, the nanosheets will disperse the soil enriching it with minerals, regardless of whether the waste is preferably managed or improperly discarded. This makes the paper layer completely uncoated and easy to recycle or biodegrade, as the paper layer is selected from the recyclable and biodegradable grades.

[0045] All embodiments of the present invention are compatible with the current paper recycling system, i.e. these embodiments must easily disintegrate when agitated into a large amount of warm water. For the currently typical industrial repulping facilities, paper packaging must break apart in warm water under constant vigorous agitation within 5 to 20 minutes.

[0046] The packaging must also quickly disintegrate if improperly discarded in the environment, thereby exposing the maximum surface area to bacteria responsible for biodegradation, ensuring complete consumption within a reasonable time. Preferably, the packaging will biodegrade within 6 to 12 months.

[0047] The recyclable paper barrier laminate according to the present application can include a printed area. Printing can be achieved using standard printing techniques such as flexographic printing, gravure printing or inkjet printing. The recyclable paper barrier laminate according to the present application can include a surface coating for aesthetic protection purposes to prevent accidental water or for a matte / gloss effect.

[0048] Paper

[0049] Cellulose fibers used to make paper can be derived from softwood, hardwood, and non-tree fibers, which generally have shorter fibers, including bamboo, grasses, hemp, kenaf, flax, corn husks, cotton stalks, coffee grounds, sugar cane bagasse, rice straw, wheat straw, algae, abaca, sabia grass, esparto grass, milkweed floss fiber, pineapple leaf fiber, wood fiber, pulp fiber, etc.

[0050] The paper layer used to make the recyclable paper barrier laminate of the present disclosure is recyclable in a typical paper recycling stream, and is preferably also biodegradable, leaving no lasting materials in the environment. In fact, paper is not made of 100% cellulose fibers, but also contains polymeric binders, mineral adhesives, whitening agents, surfactants, and other additives. These other ingredients must be properly selected to ensure that (a) the paper will disintegrate and release the maximum amount of cellulose fibers for making recycled paper in the repulping unit at a paper recycling facility, or (b) the paper will biodegrade if improperly disposed in the environment.

[0051] The effectiveness of the recycling process can be determined via the percent recyclable. The percent recyclable of the recyclable paper barrier laminate of the present disclosure is determined by Class II of test method PTS-RH: 021 / 97 (October 2019 draft) as performed by the Papiertechnische Stiftung located at Pirnaer Strasse 37, 01809 Heidenau, Germany. Along with the percent recyclable, the total percent off-spec is also determined by Class II of PTS-RH: 021 / 97 (October 2019 draft). The total percent off-spec of the packaging material of the present disclosure can be 40% or less, 30% or less, or 10% or less, specifically including all values and any ranges therein or thereby formed. For example, the total percent off-spec of the packaging material of the present disclosure can be from about 0.5% to about 40%, from about 0.5% to about 30%, or from about 0.5% to about 10%, specifically reciting all values and any ranges therein or thereby formed.

[0052] It is believed that the percent of non-recyclable material does not necessarily have a 1 : 1 correlation with the total percent off-spec. For example, dissolvable adhesives and / or coatings are designed to dissolve during the recycling process. Theoretically, these adhesives can not affect the total percent off-spec; however, they will contribute to the percent by weight of non-recyclable material.

[0053] Class II of test method PTS-RH: 021 / 97 (October 2019 draft) also includes a visual component. A trained screener inspects one or more recycled packaging materials for visual defects. If the number of visual defects is too many, then the packaging material is off-spec. If the number of visual defects is acceptable according to Class II of test method PTS-RH: 021 / 97 (October 2019 draft), then the packaging material is approved for additional processing. The paper barrier laminate of the present disclosure can produce an acceptable level of visual defects during this step of the method.

[0054] The paper barrier laminate of the present disclosure can produce the previously mentioned percent recyclable and pass the visual screening method. Thus, the paper barrier laminate of the present disclosure can receive a passing total score or final result when subjected to Class II of test method PTS-RH: 021 / 97 (October 2019 draft).

[0055] It is also worth noting that there are alternative methods for determining the percent recyclable of the paper barrier laminates of the present disclosure. A test method performed by the University of Western Michigan, known as the Repulpability Test Method, can provide a percent yield of recyclable material. While the Repulpability Test Method performed by the University of Western Michigan has minor differences from Category II of test method PTS-RH:021 / 97 (Draft October 2019), it is believed that the percent yield of the Repulpability Test Method will be similar to the percent recyclable provided by Category II of method PTS-RH:021 / 97 (Draft October 2019).

[0056] It is also important that the paper recycling facility can obtain at least 50 wt% of cellulosic fibers from an incoming batch of waste paper for commercial reasons. To this end, it is preferred that the paper layer itself comprises at least between 50 wt% and 100 wt% of cellulosic fibers, more preferably between 65 wt% and 90 wt% of cellulosic fibers, most preferably between 75 wt% and 95 wt% of cellulosic fibers.

[0057] It is contemplated that the recyclable paper of the present disclosure, while recyclable, can itself comprise recycled material. For example, the recyclable paper of the present disclosure can comprise greater than 10 wt%, preferably greater than 20 wt%, more preferably greater than 30 wt% of recycled material, specifically reciting all values and any ranges generated thereby. The recyclable paper can comprise between 0% and 100% of virgin paper or recycled paper or a mixture thereof.

[0058] The presence of recycled material can be detected by visual inspection of the package. Often, manufacturers advertise the use of recycled material to prove their eco-friendly image. To this end, they can employ a logo such as a leaf and text indicating that recycled material is used in the package. The manufacturer can also specify the percent of recycled material used, for example, more than 50%, more than 70%, etc.

[0059] Visual inspection can simply utilize the human eye to search for a logo regarding the use of recycled material. Additionally or alternatively, visual inspection can include microscopy, such as optical microscopy, scanning electron microscopy, or other suitable methods known in the art. For example, a package material comprising recycled paper fibers can look different under a microscope due to the wider range of natural fibers present compared to a package material comprising 100% virgin fibers.

[0060] It is preferred that the paper is as flat as possible on at least one side, which is then coated with an aqueous polymer solution to form the adjacent water-soluble polymer layer. The paper can be flattened by "sizing", which in the industry means that it can be coated with an aqueous polymer suspension containing various inorganic fillers such as clay, calcium carbonate and / or titanium dioxide, the suspension is then dried, and the paper is calendered to get a flatter surface than before sizing, as the inorganic fillers and binder are dehydrated to fill the porous rough surface of the paper. Alternatively, the paper can be mechanically glazed during the papermaking process by a mechanical ironing / pressing step, which sometimes involves heating - in this case, the paper fibers are pressed together and flattened in order to densify the paper surface and remove pores. In some cases, sizing and mechanical glazing are combined to obtain an even flatter, more perfect surface during the papermaking process, which is then coated with a water-soluble polymer layer. In other cases, a kraft paper or glassine paper or tracing paper that is already naturally very flat can be used, such papers are manufactured by methods that densify the paper structure throughout its thickness during the manufacturing process, and do not require further sizing or glazing.

[0061] Examples of papers suitable for making recyclable paper barrier laminates include: Leine Nature 85 g / m2paper from Sappi (Fife, Scotland), a mechanical glazed paper with "OK Home Compost" certification; NiklaSelect V Natural Linen paper (99 g / m2) from Birgl & Bergmeister (Niklasdorf, Austria), a paper sized on only one side; PackPro 7.0 paper (65 g / m2) from Birgl & Bergmeister, a paper sized on both sides; Axello paper from BillerudKorsnäs (Solna, Sweden); (including Axello Tough White paper, 80 g / m2), which is designed to be tougher than many other papers, so can have some advantages in the distribution chain; SCG Glassine paper (58 g / m2) from SCG / Prepack. ® ® 2 2 2 ™ 2 2

[0062] As shown in Table 1 below, these papers all passed the paper recycling protocols of Western Michigan University in the USA and PTS Institute in Germany. These papers also passed the OECD 301B Biodegradation Screening Test, experiencing at least 60% biodegradation in 28 days.

[0063] Table 1

[0064] ​​​​​​​​

[0065] To withstand the stresses of high speed manufacturing processes where the product is placed inside a package made of the laminates disclosed in the present invention as well as the stresses of transportation, the paper layer must be strong enough and resilient. There are numerous ways to specify a paper layer. The metrics discussed below are MD tensile strength in kN / m, CD tensile strength in kN / m, MD stretch in percent, CD stretch in percent, MD burst strength in kPa, thickness in pm, MD tensile energy absorption in J / g, CD tensile energy absorption in J / g and grammage in g / m2. While all metrics can be used in combination to select a suitable paper in the present invention, some metrics alone or in combination with other metrics can also meet the requirements. 2 ® ®

[0066] In cases where very strong paper is needed to maintain the physical integrity of the water dispersible barrier layer, it is preferred to use Axello® paper from BillerudKorsnäs. For example, Table 2 below shows the properties of Axello® Strong White paper grade from BillerudKorsnäs or Advantage Smooth White Strong paper from Mondi.

[0067] Table 2

[0068]

[0069] Water-soluble polymer

[0070] ​​​Preferred polymers, copolymers or derivatives thereof suitable for use as the water-soluble polymer layer are selected from the group consisting of polyvinyl alcohol (PVOH), water-soluble polymer layers of copolymers or derivatives of polyvinyl alcohol copolymers such as butylenediol-vinyl alcohol copolymers (BVOH) produced by copolymerization of butylenediol with vinyl acetate followed by hydrolysis of the vinyl acetate, suitable butylenediol monomers selected from the group consisting of 3,4-diol-1 -butene, 3,4-dioxy-1 -butene, 3-oxy-4-ol-1 -butene, 4-oxy-3-ol-1 -butene and the like; polyvinylpyrrolidone; polyalkylene oxides such as polyethylene oxide or polyethylene glycol (PEG); poly(methacrylic acid), polyacrylic acid, polyacrylate, acrylate copolymers, maleic / acrylic acid copolymers; polyacrylamide; poly(2-acrylamido-2-methyl-1 -propane sulfonic acid (polyAMPS); polyamides, poly-N-vinylacetamide (PNVA); polybasic carboxylic acids and salts; cellulose derivatives such as cellulose ether, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose; hydroxypropyl methyl cellulose; natural gums such as xanthan gum and carrageenan; sodium alginate; maltodextrin, low molecular weight dextrin; polyamino acids or peptides; proteins such as casein and / or caseinate (e.g. those commercialized by Lactips).

[0071] The most preferred polymers are polyvinyl alcohol, polyethylene oxide, methyl cellulose and sodium alginate. For applications requiring "plastic-free" products, most of the components of the water-soluble polymer layer can be naturally derived polymers such as sodium alginate. Preferably, the content of polymer in the water-soluble polymer layer is at least 60%.

[0072] The water-soluble polymers have an average molecular weight (measured by gel permeation chromatography) of from about 1,000 Da to about 1,000,000 Da, or any integer value of from about 1,000 Da to about 1,000,000 Da, or any range formed from any of the preceding values, such as from about 10,000 Da to about 300,000 Da, from about 20,000 Da to about 150,000 Da, and the like. More specifically, the molecular weight of the polyvinyl alcohol can be in the range of 20,000 Da to 150,000 Da. The molecular weight of the polyethylene oxide will be in the range of 50,000 Da to 400,000 Da. The molecular weight of the methyl cellulose will be in the range of 10,000 Da to 100,000 Da. The molecular weight of the sodium alginate will be in the range of 10,000 Da to 240,000 Da.

[0073] If a homopolymer polyvinyl alcohol is used, the degree of hydrolysis can be from 70% to 100%, or any integer percentage value between 70% and 100%, or any range formed by any of these values, such as 80% to 100%, 85% to 100%, 90% to 100%, 95% to 100%, 98% to 100%, 99% to 100%, 85% to 99%, 90% to 99%, 95% to 99%, 98% to 99%, 80% to 98%, 85% to 98%, 90% to 98%, 95% to 98%, 80% to 95%, 85% to 95%, 90% to 95%, and the like.

[0074] Optional Ingredients

[0075] The water-soluble polymer layer of the recyclable paper barrier laminate can include a disintegrant, a plasticizer, a surfactant, a lubricant / peel agent, a filler, an extender, an anti-blocking agent, an anti-sticking agent, an antifoaming agent, or other functional ingredients.

[0076] Certain applications can require the water-soluble polymer layer to include a disintegrant to increase its rate of dissolution in water. Suitable disintegrants are, but not limited to, corn / potato starch, methylcellulose, mineral clay powder, cross-linked carboxymethylcellulose (croscarmellose), crospovidone (cross-linked polyvinyl N-pyrrolidone or PVP), sodium starch glycolate (cross-linked starch). Preferably, the water-soluble polymer layer includes between 0.1 wt% and 15 wt%, more preferably about 1 wt% to about 15 wt% of a disintegrant.

[0077] In some embodiments, the water-soluble polymer layer can comprise a water-soluble plasticizer. Preferably, the water-soluble plasticizer is selected from the group consisting of water, polyhydric alcohols, sugar alcohols, and mixtures thereof. Suitable polyhydric alcohols include polyhydric alcohols selected from the group consisting of glycerol, diglycerol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol up to 400 Da molecular weight, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol, methyl diglycol, trimethylolpropane, hexanediol, neopentyl glycol, and polyether polyols, or mixtures thereof. Suitable sugar alcohols include sugar alcohols selected from the group consisting of isomalt, maltitol, sorbitol, xylitol, erythritol, ribitol, galactitol, pentaerythritol, and mannitol, or mixtures thereof. In some cases, the plasticizer can be selected from the following list: ethanolamine, alkyl citrates, isosorbide, pentaerythritol, glucosamine, N-methylglucamine, or sodium isopropylbenzenesulfonate. A less mobile plasticizer such as sorbitol or polyethylene oxide can facilitate the formation of a water-soluble polymer layer with greater barrier properties compared to a water-soluble polymer layer including a more mobile plasticizer such as glycerol. In some cases, the following plasticizers can also be used when it is desired to use as many naturally derived materials as possible: vegetable oil, polysorbate, dimethicone, mineral oil, paraffin, C1-C3 alcohol, dimethyl sulfoxide, N,N-dimethylacetamide, sucrose, corn syrup, fructose, sodium dioctyl sulfosuccinate, triethyl citrate, tributyl citrate, 1,2-propanediol, mono-, di- or triacetate of glycerol, natural gums, citrate salts, and mixtures thereof. More preferably, the water-soluble plasticizer is selected from glycerol, 1,2-propanediol, 20 dipropylene glycol, 2-methyl-1,3-propanediol, trimethylolpropane, triethylene glycol, polyethylene glycol, sorbitol, or mixtures thereof, most preferably from glycerol, sorbitol, trimethylolpropane, dipropylene glycol, and mixtures thereof. Preferably, the water-soluble polymer layer comprises between 5 and 50 wt%, preferably between 10 and 40 wt%, even more preferably about 12 to about 30 wt% of the plasticizer.

[0078] In some embodiments, the water-soluble polymeric layer according to the present application comprises a surfactant. Suitable surfactants can belong to the non-ionic, cationic, anionic or zwitterionic class. Suitable surfactants are, but are not limited to, poloxamers (polyoxyethylene polyoxypropylene glycols), alcohol ethoxylates, alkylphenol ethoxylates, tertiary acetylenic glycols and alkanolamides (non-ionic), polyoxyethylene amines, quaternary ammonium salts and polyoxyethylene quaternary amines (cationic), and amine oxides, N-alkyl sultaines and sultaines (zwitterionic). Other suitable surfactants are sodium sulfosuccinates, acylated fatty acid esters of glycerol and propylene glycol, lactic acid fatty acid esters, sodium alkyl sulfates, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, lecithin, acylated fatty acid esters of glycerol and propylene glycol, and acetylated esters of 5 fatty acids and combinations thereof. Preferably, the water-soluble polymeric layer comprises between 0.1 and 2.5 wt%, more preferably about 1 to about 2 wt% of surfactant.

[0079] In some embodiments, the water-soluble polymeric layer according to the present application comprises a lubricant / peeling agent. Suitable lubricants / peeling agents are, but are not limited to, fatty acids and their salts, fatty alcohols, fatty acid esters, fatty amines, fatty amine acetates and fatty amides. Preferred lubricants / peeling agents are fatty acids, fatty acid salts, fatty amine acetates and mixtures thereof. Preferably, the water-soluble polymeric layer comprises 0.02 to 1.5 wt%, preferably about 0.1 to about 1 wt% of lubricant / peeling agent.

[0080] In some embodiments, the water-soluble polymeric layer according to the present application comprises a filler, extender, anti-blocking agent, detackifier. Suitable fillers, extenders, anti-blocking agents, detackifiers are, but are not limited to, starch, modified starch, cross-linked polyvinylpyrrolidone, cross-linked cellulose, microcrystalline cellulose, silicon dioxide, metal oxides, calcium carbonate, talc and mica. Preferably, the water-soluble polymeric layer comprises 0.1 to 25 wt%, more preferably about 1 to about 15 wt% of filler, extender, anti-blocking agent, detackifier. In the absence of starch, the water-soluble polymeric layer preferably comprises 1 to 5 wt% of filler, extender, anti-blocking agent.

[0081] In some embodiments, the water-soluble polymeric layer according to the present application comprises an antifoam agent. Suitable antifoam agents are, but are not limited to, polydimethylsiloxane and hydrocarbon blends. Preferably, the water-soluble polymeric layer comprises between 0.001 and 0.5 wt%, more preferably about 0.01 to about 0.1 wt% of antifoam agent.

[0082] The recyclable paper barrier laminate according to the invention may contain residual moisture, depending on the hygroscopicity and isotherm of the laminate components under given temperature and humidity conditions, as determined by Karl Fischer titration. For example, a water-soluble polyvinyl alcohol layer may contain about 4% to 8% residual moisture at 23°C and 50% relative humidity.

[0083] Water-dispersible nanosheets

[0084] Nanosheets are solid, sheet-like nanoparticles characterized by a high aspect ratio between their diameter and orthogonal height. This high aspect ratio provides the nanosheets with parallel alignment and a longer diffusion path length for chemicals, thus offering barrier properties. It is desirable that the nanosheets lack defects such as cracks and pores that degrade barrier performance. It is also desirable that the nanosheets readily peel off in water for both application purposes (e.g., wet coating) and end-of-life situations (e.g., wastewater treatment plants), but exhibit high viscosity when dry. Nanosheets are currently used industrially as rheology modifiers, flame retardants, anti-corrosion coatings, and / or chemical barrier agents. Nanosheets can be obtained from natural sources and used as is, or can be purified and modified from natural sources, or synthesized in a furnace for reasons of purity and performance.

[0085] Natural shale silicates (such as serpentine, clay, chlorite, and mica) consist of stacked nanosheets. Natural clays (such as kaolinite, pyrophyllite, vermiculite, and montmorillonite) consist of stacked nanosheets that swell in the presence of water. Montmorillonite (such as montmorillonite and lithium montmorillonite) consists of stacked nanosheets and swells most readily in the presence of water. Natural montmorillonite can be purified and modified, such as sodium corosette from BYK, which is made from bentonite (a natural mineral containing 60% to 80% montmorillonite) and cation-exchanged with monovalent sodium for exfoliation purposes. Montmorillonite can also be synthesized, such as synthetic lithium montmorillonite from BYK and sodium lithium montmorillonite from the University of Bayreuth. Other nanosheets are graphene and graphene oxides, such as those provided by Applied Graphene Materials, and are characterized by a high aspect ratio between their diameter and orthogonal height.

[0086] Method for preparing recyclable paper barrier laminates

[0087] There are many non-limiting embodiments of the method for preparing the recyclable paper barrier laminate described herein. For example... Figure 5 As shown, water-soluble membranes with integrated water-dispersible barrier functions can be prepared under specific conditions through multiple steps of coating and drying aqueous polymer solutions or aqueous nanosheet dispersions.

[0088] In one embodiment, a method for preparing a recyclable paper barrier laminate includes the following steps:

[0089] a) applying a first aqueous solution of a water-soluble polymer composition onto the surface of a removable flat carrier such as an untreated PET film, a stainless steel belt, a fluorinated polymer belt or any other suitable carrier material

[0090] b) removing water from the first aqueous solution of the water-soluble polymer composition to obtain a first water-soluble polymer layer 20

[0091] c) applying an aqueous dispersion of hydrophilic nanoplatelets onto the outer surface of the first water-soluble polymer layer

[0092] d) removing water from the aqueous dispersion of hydrophilic nanoplatelets to obtain a water-dispersible barrier layer 30

[0093] e) applying a second aqueous solution of a water-soluble polymer composition onto the sized inner surface of the recyclable paper layer 10;

[0094] f) combining the outer surface of the water-dispersible barrier layer with the second aqueous solution of the water-soluble polymer composition

[0095] g) removing water from the second aqueous solution of the water-soluble polymer composition to obtain a second water-soluble polymer layer 40

[0096] h) removing the flat carrier from the resulting recyclable paper barrier laminate.

[0097] This method provides better barrier properties because the water-dispersible barrier layer is formed on a perfectly flat surface of the water-soluble polymer layer itself, which is due to its formation on a perfectly flat surface of the removable carrier. It also provides the advantage of being rather insensitive to the porosity and surface roughness of the recyclable paper layer. Thus, it is possible to start from a recyclable paper layer which is neither surface sized nor surface glazed to obtain a recyclable paper barrier laminate according to this method.

[0098] In another embodiment, the method of making a recyclable paper barrier laminate comprises the following steps:

[0099] a) applying a first aqueous solution of a water-soluble polymer composition onto the inner surface of a recyclable paper layer, the inner surface being sized, glazed or both sized and glazed

[0100] b) removing water from the first aqueous solution of the water-soluble polymer composition to obtain a first water-soluble polymer layer 20

[0101] c) applying an aqueous dispersion of hydrophilic nanoplatelets onto the inner surface of the first water-soluble polymer layer

[0102] d) removing water from the aqueous dispersion of hydrophilic nanoplatelets to obtain a water-dispersible barrier layer 30

[0103] e) applying a second aqueous solution of the water-soluble polymer composition onto the inner surface of the recyclable paper layer

[0104] f) removing water from the second aqueous solution of the water-soluble polymer composition to obtain a second water-soluble polymer layer 40

[0105] This alternative method provides better bonding strength between the recyclable paper layer and the water-dispersible barrier layer. It is also simpler to practice from an industrial point of view. However, it limits the choice of recyclable paper to papers suitable for coating with an aqueous polymer solution, such as papers sized on at least one side, or mechanically calendered on at least one side, or are kraft or glassine papers. In some cases, sizing and mechanical calendering can be combined to get a flatter surface of the recyclable paper.

[0106] To prepare the water-soluble polymer layer, the water-soluble polymer is typically in solid form and is first dissolved in water using moderate agitation to form an aqueous polymer solution, typically 20% by weight of water-soluble polymer to 80% by weight of water. The aqueous polymer solution is then further combined with other additives such as plasticizers under moderate agitation and high temperature. The aqueous polymer solution is then coated onto a flat surface carrier (e.g. untreated PET film, stainless steel belt, fluorinated polymer belt, or any other suitable material) and water is removed via convection or diffusion drying methods.

[0107] Without being limited by theory, it is believed that the most important material properties of the aqueous polymer solution are: a) solubility of the polymer in water at a given temperature between 20°C and 95°C; b) the resulting viscosity of the aqueous polymer solution at that temperature, higher viscosity is more advantageous for maximum differentiation / separation between layers; c) wetting behavior of the aqueous polymer solution on the flat carrier or on the water-dispersible nanoplatelets or on another water-soluble polymer layer, higher wetting is more advantageous.

[0108] The drying step is typically performed by a belt dryer such as those sold by Krönert GmbH & Co KG (Hamburg, Germany) under the trade name Drytec, by Coatema Coating Machinery GmbH (Dormagen, Germany) under the trade name ModulDry, and / or by FMP Technologies GmbH (Erlangen, Germany) under the trade name SenDry or PureDry. In some embodiments, the drying substrate is guided through a hot air tunnel by running belts (belt dryer), by multiple idlers (roller dryer), or by multiple hot air nozzles (non-contact hot air dryer). Without being limited by theory, it is believed that the most important parameters of the drying process are: the residence time of the drying substrate in the hot air tunnel, typically about 50 s for a 60 pm thick aqueous polymer system (where the polymer is water-soluble, comprising 25% solids); the temperature of the hot air, typically about 95 °C; the flow velocity of the hot air over the substrate, typically about 25 m / s. The heating system can employ electricity, hot oil, steam, or gas.

[0109] To prepare the water-dispersible barrier layer 30, typically an aqueous nanoplatelet dispersion is formed by employing water-dispersible nanoplatelets in solid form and first exfoliating them with some water under high shear (e.g. high energy ball milling) conditions, typically 80 wt% water-dispersible nanoplatelets to 20 wt% water. The aqueous nanoplatelet dispersion is then further diluted in water at moderate temperature and vigorous stirring. The aqueous nanoplatelet dispersion is then coated onto a water-soluble polymer layer and the water is removed via drying.

[0110] Without being limited by theory, it is believed that the most important material properties of the nanoplatelets are: a) the aspect ratio of the nanoplatelets (a larger aspect ratio is more beneficial for barrier performance); b) the complete exfoliation and dispersion of the nanoplatelets in water under intense shear mixing, without re-agglomeration of the nanoplatelets, resulting in a substantially uniform coating of uniformly distributed nanoplatelets, such that the uniform coating is free of defects such as pinholes or cracks. Without being limited by theory, it is also believed that the most important processability of the aqueous nanoplatelet dispersion is: the viscosity of the aqueous nanoplatelet dispersion, a higher viscosity is more beneficial for maximum differentiation / separation between the layers, and thus maximum barrier performance; the wetting behavior of the aqueous nanoplatelet dispersion on the water-soluble polymer layer or on another water-dispersible nanoplatelet layer; the shear applied on the aqueous nanoplatelet dispersion, a higher shear is more beneficial for parallel nanoplatelet orientation against the barrier plane; the removal of water from the dispersion via evaporation drying, without creating defects in the nanoplatelet layer.

[0111] A number of methods were tested for coating the aqueous nanosheet dispersion: wire bar coating, gravure coating, reverse roll coating, slot die extrusion coating, roll-to-roll coating, and spray coating. The most reliable method to provide proper feeding of the aqueous nanosheet dispersion was achieved via custom slot die (e.g. FMP Technology, Coatema) aqueous extrusion coating, while the roll-to-roll method provided the best barrier performance via superior shearing of the aqueous nanosheet dispersion, thus superior nanosheet parallel orientation, thus superior barrier performance. However, this barrier performance also depends on the total thickness of the water dispersible nanosheet layer. Typically, the thickness of the water dispersible nanosheet layer is in the range of about 0.1 pm to about 20 pm to provide sufficient barrier performance while maintaining sufficient mechanical flexibility and mechanical resistance.

[0112] In another non-limiting embodiment of the method, the water dispersible barrier layer 30 is obtained by multiple application steps of coating and drying of aqueous nanosheet dispersions, each nanosheet sublayer masking presumptive defects in the underlying nanosheet sublayer, thus providing maximum barrier performance. To this end, a first water dispersible nanosheet barrier sublayer is formed on the water soluble polymer layer according to any of the methods described above; subsequently, one or more additional water dispersible nanosheet barrier sublayers can be added until the desired water dispersible nanosheet layer thickness is obtained. Following this method, relatively thick water dispersible nanosheet layers can be formed within the water soluble film. In case it is desired to increase optical transparency and mechanical flexibility, additional water dispersible nanosheet barrier sublayers can be separated by additional thinner water soluble polymer sublayers. The various polymer sublayers or barrier sublayers can have essentially the same chemical composition or different chemical compositions to provide different properties to the overall structure. Adhesion between the sublayers is provided only by molecular interactions between the water soluble polymer and the hydrophilic nanosheets. Similarly, cohesion between the sublayers is provided only by molecular interactions between materials of the same composition or chemical nature, without the use of adhesives. The absence of adhesives will maximize the barrier performance against water permeation and maintain the dispersibility of the nanosheets in water after dissolution of the top / bottom polymer layers.

[0113] Inks, trademarks and decoration

[0114] The recyclable paper barrier laminate according to the present application can be opaque or translucent. The recyclable paper barrier laminate according to the present application can comprise a printed area. Printing can be achieved using standard printing techniques such as flexographic printing, gravure printing or inkjet printing.

[0115] The recyclable paper barrier laminate according to the present application can be arranged in countless configurations as packaging. For example, the packaging can include a plurality of panels that enclose a plurality of articles. Each of the panels includes an inner surface and an outer surface. The outer surface and / or the inner surface of one or more of the panels can include ink or dye that forms a trademark, packaging information, and / or background color, etc. on the packaging. The trademark and / or other packaging information associated with the product within the packaging is disposed on the outer surface of at least one of the panels. The trademark can include a logo, trade name, trademark, icon, etc. that is related to the product within the packaging. The trademark is utilized to inform the consumer of the product within the packaging. The packaging information can include the size of the product, the number of products within the packaging, an exemplary image of the product contained within the packaging, a recyclability logo, etc. that is related to the product within the packaging.

[0116] In all aspects of the present application, the deposited ink can be solvent-based or water-based, and the pigments within the ink can be organic or inorganic, or a combination of both. In some embodiments, the ink is highly abrasion resistant. For example, the high abrasion resistant ink can include a coating that is cured by ultraviolet radiation (UV) or electron beam (EB). In some embodiments, any organic pigments within the ink are derived from a petroleum source. In some embodiments, any organic pigments within the ink are derived from a renewable resource, such as soy, plants. In some embodiments, if the pigments are organic, any organic pigments within the ink will be biodegradable. In other embodiments, any inorganic pigments within the ink will be made from inorganic metal oxides that are dispersible and environmentally benign.

[0117] Non-limiting examples of inks include ECO-SURE I TM and solvent-based VUTEk® and BioVu™ inks from EFI, which are derived entirely from renewable resources (e.g., corn). Other examples include SunVisto AquaGreen from Sun Chemicals (Parsippany-Troy Hills, New Jersey).

[0118] The ink is present in a thickness of about 0.5 pm to about 20 pm, preferably about 1 pm to about 10 pm, more preferably about 2.5 pm to about 3.5 pm.

[0119] The recyclable paper barrier laminate of the present disclosure can include ink and / or dye to provide a background color to the package of the present disclosure. To further elucidate the background color, it is noted that the paper layer includes a base color. The base color of the paper layer is the color of the package without ink or dye. For example, the color of bleached paper is white, the color of unbleached is brown, the color of paper derived from grass is green, and the color of paper that includes recyclable content is gray. The background color is any color that is non-base, such as blue, red, green, yellow, purple, orange, black, or combinations thereof. However, the background color can also include white, brown, or gray if the color is obtained through ink and / or dye.

[0120] To reduce the use of ink / dye to facilitate the recycling process, the natural color of the paper layer can be utilized. For example, ink / dye can be used to define the background color of only the consumer-facing panel, while the natural color of the paper layer will be used as the background color of the other panels of the flexible package.

[0121] Surface coating

[0122] Preferably, the printed surface of the recyclable paper barrier laminate is surface coated to protect the ink layer from its physical and chemical environment, to enhance the durability of the paper layer and to provide a high gloss or matte finish. This optional surface coating can be referred to as a lacquer or varnish or a splash-proof layer. In some embodiments, the surface coating is made from nitrocellulose lacquer, acrylic lacquer, water-based lacquer, reactive two-component polyurethane lacquer. In some preferred embodiments, the surface coating is made from natural waxes that pass the OECD 301B biodegradation screening test, such as beeswax, rapeseed wax, or candelilla wax, provided that the exposure temperature does not exceed the wax melting point. Because the thickness of the surface coating affects the recyclability and biodegradability of the package made from the recyclable paper barrier laminate of the present invention, a thinner surface coating is preferred. The thickness of the surface coating is preferably between 1 pm to 25 pm, more preferably less than 10 pm, even more preferably less than 5 pm.

[0123] Method of making recyclable paper-based packages

[0124] The recyclable paper barrier laminate described herein can form articles, including but not limited to articles in which a typical film or sealable paper would be used as a packaging material. Such articles include, but are not limited to, bags, pouches, sachets, flow wraps, pillow packs, and other containers. The bags, pouches, sachets, flow wraps, pillow packs, and other such containers incorporating the recyclable paper barrier laminate described herein can be made in any suitable manner known in the art.

[0125] The recyclable paper barrier laminates prepared according to the present application can be converted into packages and articles using a form-fill-seal method (FFS). Conventional FFS methods generally involve three sequential steps in which a package or article is formed from a paper laminate, filled, and then sealed or closed, as described in U.S. Patent No. 6,293,402, which is incorporated herein by reference. In a heat sealing method, there is a temperature range above which the seal will be burned off and below which the seal will not be strong enough. The seal is provided in any sealing manner known to those skilled in the art. The seal can include applying a continuously heated element to the paper laminate, which is then removed after the seal is made. The heating element can be a hot bar including rotating jaws or a heated wheel. Different seal types include fin seals and overlap seals.

[0126] Single pass method

[0127] A well-known single pass method of sealing using a vertical form and fill machine is described in U.S. Patent No. 4,521,437, which is incorporated herein by reference. In this method, a flat web of material is unwound from a roll and formed into a continuous tube by sealing the longitudinal edges of the film together to form a lap seal (i.e., a fin seal). The resulting tube is pulled vertically downward to a fill station and collapsed over a cross section of the tube, the location of such cross section being at a sealing apparatus below the fill station. A transverse heat seal is formed by the sealing apparatus at the collapsed portion of the tube, thereby forming an air-tight seal across the tube. After the transverse seal is formed, a predetermined volume of material to be packaged (e.g., a flowable material) enters the tube at the fill station and fills the tube upward from the transverse seal described above. The tube then falls a predetermined distance under the weight of the material in the tube and the weight of a film advance mechanism on the machine. The jaws of the sealing apparatus close and collapse the tube at a second cross section located above the air / material interface in the tube. The sealing apparatus transversely seals and cuts the tube at the second cross section. The material-filled portion of the tube is now in the form of a pillow-shaped pouch. In this way, the sealing apparatus seals the top of the filled pouch, seals the bottom of the next to be formed pouch, and separates the filled pouch from the next to be formed pouch in one operation.

[0128] Multiple pass method

[0129] The packages of the present invention can also be processed using a multi-lane pouch packaging machine, such as the VEGA PACK 300S manufactured by QuadroPack (Nijeveen, Netherlands). A high speed multi-lane pouch processing machine is also described in U.S. Patent No. 6,966,166, which is incorporated herein by reference. The machine used in this method includes two rollers for dispensing sheets of equal sized web film, a plurality of sealing devices adapted for such substrates and devices, such as pump stations for inserting contents (e.g., liquids, viscous materials, powders and other substances) into the film packages as described below. A plurality of packages can be produced by utilizing one or more movable reciprocating carriages that travel with the flow of film through the machine, which support each of the sealing and cross-cut stations. The sealing devices are applied to all edges except one, thereby forming a pouch having a cavity and an opening. The desired contents of the package are inserted into the cavity through the opening. The opening is then sealed and separated from the substrate. A pair of substrate rollers are provided at the substrate roller station. Alternatively, a cutter can be placed in the middle of a single pinch roller to divide the substrate width into two equal portions. The sheets of paper laminate are advanced through the device by a traction wheel station and are used to form the front and back panels of the package. The paper laminates from each roller are directed so that as the two sheets of paper laminate advance through the machine, the two sheets of paper laminate are in close proximity to each other and in parallel relationship. The sealing and cutting devices include a longitudinal sealing bar for sealing the vertical edges of the package, a one-way roller for holding the paper laminate in place and preventing it from sliding back, a vertical cutter for cutting a tear-away slit in the vertical direction into the package, and a transverse sealing bar for sealing the package in the horizontal direction. The pump stations include a plurality of fill dispensers in communication with a storage structure that houses the consumer product in the package. These dispensers can draw a predetermined amount of consumer product from a reservoir and deposit it into the cavity of the paper laminate package formed by the machine. In a preferred embodiment, the pump stations and dispensers can be driven by one or more motion-controlled servo motors in communication with a cam system. The amount of consumer product can be varied by swapping out dispensers (different dispensers with different capacities), changing the stroke of the pump cycle, changing the timing of the pump cycle, etc. Thus, depending on the size and capacity of the package that the machine is to form, different amounts of consumer product can be dispensed.

[0130] The sealing mechanism can be a heat seal, a water seal, a moisture seal, an ultrasonic seal, an infrared seal, or any other type of seal deemed suitable.

[0131] Article of manufacture

[0132] As Figure 7As shown, the present application also includes an article comprising a product composition and a recyclable paper barrier laminate that can form a container, such as a pouch, sachet, capsule, bag, and the like, to contain the product composition. For simplicity, the article of interest herein will be described as a recyclable barrier paper pouch, but it is understood that the discussion herein also applies to other types of containers.

[0133] The pouch formed by the foregoing method can be in any form and shape suitable to hold the composition contained therein until it is desired to release the composition from the recyclable paper barrier laminate pouch, such as by tearing it open. The pouch can include one compartment or two or more compartments (i.e., the pouch can be a multi-compartment pouch). In one embodiment, the recyclable paper barrier laminate pouch can have two or more compartments.

[0134] In one embodiment, the recyclable paper barrier laminate can be sealed to a water-soluble barrier film without the attachment of paper. This can create a window into the package so that the consumer can see the product without changing the recyclability of the package.

[0135] The pouch or other container can contain a unit dose of one or more compositions from a range of products, which can include, but are not limited to, consumer products. As used herein, “consumer product” refers to materials used, for example, for hair care, cosmetic care, oral care, health care, personal cleansing, and home cleaning. Non-limiting examples of consumer products include shampoo, conditioner, mousse, facial cleanser, hand soap, body soap, liquid soap, bar soap, moisturizer, body lotion, shaving lotion, toothpaste, mouthwash, hair gel, hand sanitizer, laundry detergent composition, dish detergent, automatic dishwasher detergent composition, hard surface cleaner, stain remover, fabric enhancer and / or fabric softener, cosmetic and non-prescription medication, electronic product, pharmaceutical, candy, pet health care product, medical cannabis-derived product, industrial cannabis-derived product, CBD-based product, other product derived from non-cannabis medication, vitamin, non-medication natural / herbal “health” product, razor, absorbent article, wipe, hair gel, food and beverage, animal food product, and new product forms. Typical absorbent articles of the present application include, but are not limited to, diapers, adult incontinence briefs, training pants, diaper holders, sanitary pads, incontinence pads, liners, absorbent inserts, pantiliners, tampons, and the like.

[0136] The composition within the bag can be in any suitable form including, but not limited to: powder, solid foam, fiber, solid, granules, liquid, gel, paste, cream, capsule, pill, dragee, solid foam, fiber, absorbent article, nonwoven, and the like. The bag is particularly suitable for dry products, except for some paste, gel, liquid products that contain less than 30% water, more preferably less than 20% water. The packages and articles of the present invention are resistant to consumer products. As used herein, "resistant" refers to the ability of the package and article to maintain its mechanical properties and appearance on its surface at the time of design without causing degradation of the package and article via diffusion of the consumer product through the packaging material.

[0137] Additional product forms (articles) include disposable aprons, laundry bags, disposable medical bed linens, skin patches, face masks, disposable gloves, disposable medical gowns, medical devices, skin wraps, agricultural mulch, shopping bags, fill bags, reloadable components in durable systems, sandwich bags, trash bags, emergency blankets and clothing, building / construction structure wraps and moisture barriers, primary packaging for shipping such as envelopes and mailing bags, non-absorbent clothing articles that can be used to encase clothing such as dresses, shirts, suits, and shoes.

[0138] Different compartments of a multi-compartment bag can be used to separate incompatible ingredients. For example, it can be desirable to separate dry shampoo and dry conditioner or laundry detergent and laundry additives into separate compartments.

[0139] Due to the improvements in water vapor and oxygen barrier, dyes and fragrances that are commonly used in some products should be more stable inside a bag made from a recyclable paper barrier laminate than a bag made from a non-barrier paper laminate. Also, the barrier to migration of oils, surfactants, and other chemicals contained by the package can be improved compared to a package made from a non-barrier paper laminate.

[0140] At the end of the life of the package, the consumer can recycle the package in a conventional paper recycling system. The structure will be broken down in a repulping system so that the paper fibers can be recycled. The soluble polymers will dissolve and be filtered out, will eventually biodegrade, or the soluble polymers can be recovered from the waste water of the recycling plant for reuse. Any barrier materials are inert, non-harmful, and naturally occurring and will safely disperse in the waste water. However, if discarded, the package will biodegrade in 6 to 12 months.

[0141] To facilitate and promote recyclability of the package, the package made from the structures of the present disclosure can comprise less than 50 wt.% of inks, dyes, barrier layers, polymeric layers, glues, and / or synthetic fibers. The weight percent of inks, dyes, barrier layers, polymeric layers, glues, and / or synthetic fibers in the package can be less than 50 wt.%, more preferably less than 30 wt.%, or most preferably less than 10 wt.%, specifically reciting all values and any ranges resulting from such recitation. For example, the weight percent of inks, dyes, barrier layers, polymeric layers, glues, and / or synthetic fibers in the package material can be between 0.1 wt.% and 50 wt.%, more preferably between 0.1 wt.% and 30 wt.%, or most preferably between 0.1 wt.% and 10 wt.%, specifically reciting all values and any ranges resulting from such recitation. In one specific example, the amount of inks, dyes, barrier layers, polymeric layers, glues, and / or synthetic fibers is 5 wt.% or less, or between 0.1 wt.% and 5 wt.%, specifically reciting all values and any ranges resulting from such recitation.

[0142] It is preferred that the resulting whole package made from the recyclable paper barrier laminate described in the present disclosure comprises at least 50 wt.% natural cellulose fibers, at least 70 wt.% natural cellulose fibers, or at least 90 wt.% natural cellulose fibers, specifically reciting all values and any ranges resulting from such recitation.

[0143] The recyclability of the package according to the present disclosure can be determined by a recyclability percentage. The paper barrier laminate according to the present disclosure can exhibit a recyclability percentage of 50% or greater, more preferably 70% or greater, or most preferably 80% or greater, specifically reciting all values and any ranges resulting from such recitation. The paper barrier laminate according to the present disclosure can have a recyclability percentage yield of between 50% to about 99%, more preferably between about 85% to about 99%, or most preferably between about 90% to about 99%.

[0144] Test Methods

[0145] When testing and / or measuring materials, if a specific temperature is not specified by the relevant test method, the test and / or measurement is performed on a test specimen at a temperature of 23 °C (± 3 °C), where such test specimen is preconditioned to that temperature. When testing and / or measuring materials, if a specific humidity is not specified by the relevant test method, the test and / or measurement is performed on a test specimen at a humidity of 35% (± 5%), where such test specimen is preconditioned to that humidity. The test and / or measurement shall be performed by trained, skilled, and experienced personnel according to good laboratory practices via suitably calibrated equipment and / or instruments.

[0146] 1) Thickness of individual layers / whole laminate

[0147] The thickness of the overall film / individual layers is measured by cutting 20 pm thick cross sections of the film sample via a sliding microtome (e.g., Leica SM2010 R), placing it under an optical microscope in light transmission mode (e.g., Leica Diaplan), and applying imaging analysis software. The water dispersible nanoplatelets form a strong contrast with the water soluble polymer layer. The contrast can be achieved by adding different tracers such as 0.5 wt% Rhodamine B or 0.5 wt% titanium dioxide nanoparticles in the vicinity of the water soluble polymer layer.

[0148] 2) Water Vapor Transmission Rate (WVTR)

[0149] This test method is performed according to ASTM F1249-13 at the following test conditions: temperature of 40 °C (± 0.56 °C) and relative humidity of 50% (± 3%). If tropical conditions are required, the temperature is set to 38 °C (± 0.56 °C) and the relative humidity is set to 90% (± 3%). The water vapor transmission rate is reported in g / m 2 / day. If normalized by barrier thickness, the water vapor transmission rate is reported in g. pm / m 2 / day. For materials that are outside the range of ASTM F-1249-13 (§ 1.1), the water vapor transmission rate test method is not applicable.

[0150] 3) Biodegradation Test

[0151] Aerobic biodegradation is measured by the production of carbon dioxide (CO2) from a sample specimen according to OECD Chemicals Testing Guidelines Section 3, Test Method 301B and Test Guideline 306. OECD 301B is applicable to the main components (paper, barrier layer, sealant) and the final package. The final package includes all the main and secondary (ink, varnish) components and is open to simulate its disposal after consumption. OECD 306 is applicable to the final package tested in seawater. The pass / fail success criteria are shown below:

[0152] g

[0153]

[0154] The fully formed pouch represents the final form of the pouch (containing all dyes and coatings) that will be disposed in the environment. The pouch will be slit open to simulate being torn open by the consumer.

[0155] The sample should biodegrade at least 60% within 60 days, preferably at least 60% within 28 days.

[0156] Examples

[0157] 1. Recyclable paper barrier laminate based on paper, polyvinyl alcohol, and sodium corosette

[0158] Preparation of water-based sealing layer composition

[0159] 1070 g of deionized water was heated to 50 °C in a Thermomix™ 5. 400 g of solid PVOH powder (Selvol 205, from Sekisui Chemicals, Tokyo, Japan) was added at a stirring level of 2.5 to 3.0, and the temperature was set to 85 °C. When the temperature of 85 °C was reached (within approximately 5 minutes), the stirring level was reduced to 1.0 to 1.5 to avoid extreme foaming. After stirring continuously at 85 °C for 30 minutes, the polymer dissolved. In parallel, 50 g of sorbitol and 50 g of glycerol were mixed with 100 g of deionized water at 85 °C. Then, both the polymer and plasticizer solutions were mixed at 85 °C at a stirring level of 1.0 to 1.5 for approximately 5 minutes. The solution was left to stand at room temperature overnight to eliminate any residual foam.

[0160] Preparation of water-based barrier layer compositions

[0161] 1120g of deionized water was heated to 50°C in a Thermomix™ 5. 100g of masterbatch paste (CNaMGH from MBN Nanomaterialia, composed of 80% sodium krosette from BYK, exfoliated in 20% water) was added at a stirring level of 3.0. Krosette is a natural bentonite with an aspect ratio of approximately 200, while natural Ca... 2+ Na + Replace it to allow it to peel off in a polar medium. Once complete, increase the stirring level to 5.0 and scrape off any remaining paste agglomerates from the mixing vessel walls / mixer blades. After stirring continuously at level 5.0 for 30 minutes, the nanoparticles are uniformly dispersed to form a brown, viscous liquid / gel, leaving some gel on the vessel walls, which must be removed using a soft spatula.

[0162] Preparation of aqueous laminate compositions

[0163] 650 g of deionized water was heated to 50 °C in a Thermomix TM5. 400 g of solid PVOH powder (Selvol 205 from Sekisui Chemicals) was added at a stirring level of 2.5 to 3.0 and the temperature was set to 85 °C. When the temperature of 85 °C was reached (within about 5 minutes), the stirring level was reduced to 1.0 to 1.5 to avoid extreme foaming. After 30 minutes of continuous stirring at 85 °C, the polymer was dissolved. In parallel, 100 g of glycerol was mixed with 100 g of deionized water at 85 °C. Then, both the polymer and plasticizer solutions were mixed together at 85 °C for about 5 minutes at a stirring level of 1.0 to 1.5. The solution was stored overnight at room temperature to eliminate any residual foam.

[0164] Preparation of a recyclable paper barrier laminate based on paper, polyvinyl alcohol and sodium collose

[0165] In one non-limiting embodiment (Sample 1), the first water-soluble polymeric sealant layer was formed by extrusion coating 100 µ of the aqueous sealant layer composition at 85 °C via a slot die from FMP Technology GmbH (Erlangen, Germany) onto an untreated PET carrier film (Hostaphan RN 50-350 from Mitsubishi, Tokyo, Japan) followed by removal of water via a convection dryer from FMP Technology set to 95 °C. The composition of the resulting 34 µ dry layer was 80% Selvol 205 (from Sekisui Chemicals), 10% glycerol and 10% sorbitol. As a next step, the water-dispersible nanoplatelet barrier layer was added by extrusion coating 60 µ of the aqueous barrier layer composition at 50 °C via a slot die from FMP Technology onto the first single water-soluble polymeric sealant layer followed by removal of water via a convection dryer from FMP Technology set to 95 °C. The composition of the resulting 4 µ dry layer was 100% of sodium collose from BYK. Finally, the multilayer structure was laminated on an internally sized paper grade of 99 µ thickness, which was obtained as NiklaSelect V natural flax from Birgl & Bergmeister (B&B), coated with a 12 µ aqueous lamination layer composition at the Line Laminating & Technology Center (Neuss). The water in the solution was absorbed into the paper. The composition of the resulting 5 µ dry layer was 80% Selvol 205 (from Sekisui Chemicals) and 20% glycerol (from Cremer).

[0166] In another non-limiting embodiment (Sample 2), the first water-soluble polymeric sealant layer was formed by extrusion coating 100 µ of the aqueous sealant layer composition at 85 °C via a slot die from FMP Technology gmbh onto an untreated PET carrier film (Hostaphan RN 50-350 from Mitsubishi) followed by removal of water via a convection dryer from FMP Technology set to 95 °C. The resulting 34 µ dry layer had a composition of 80% Selvol 205 (from Sekisui Chemicals), 10% glycerol, and 10% sorbitol. As a next step, the first water-dispersible nanoplatelet barrier sublayer was added by extrusion coating 60 µ of the aqueous barrier layer composition at 50 °C via a slot die from FMP Technology onto the first single water-soluble polymeric sealant layer followed by removal of water via a convection dryer from FMP Technology set to 95 °C. The resulting 4 µ dry layer had a composition of 100% of Coroset Sodium from BYK. The second water-dispersible nanoplatelet barrier sublayer was then added by extrusion coating 60 µ of the aqueous barrier layer composition at 50 °C via a slot die from FMP Technology onto the first water-dispersible nanoplatelet barrier sublayer followed by removal of water via a convection dryer from FMP Technology set to 95 °C. The resulting 1 µ dry layer had a composition of 100% of Coroset Sodium from BYK. Finally, the multilayer structure was laminated on a recyclable 99 µ thickness paper grade of the inside sizing side as Nikla Select V natural flax from Birgl & Bergmeister (B&B) coated with a 12 µ aqueous lamination layer composition at Line Laminating & Technology Center (Neuss). The water in the solution was absorbed into the paper. The resulting 5 µ dry layer had a composition of 80% Selvol 205 (from Sekisui Chemicals) and 20% glycerol (from Cremer).

[0167] In another non-limiting embodiment (Sample 3), the first water-soluble polymeric sealant layer was formed by extrusion coating 100 µ aqueous sealant layer composition at 85 °C via a slot die from FMP Technology gmbh onto an untreated PET carrier film (Hostaphan RN 50-350 from Mitsubishi) followed by removal of water via a convection dryer from FMP Technology set at 95 °C. The resulting 34 µ dry layer had a composition of 80% Selvol 205 (from Sekisui Chemicals), 10% glycerol, and 10% sorbitol. As a next step, the first water-dispersible nanoplatelet barrier sublayer was added by roll-to-roll coating at room temperature of a 14 µ aqueous barrier layer composition onto the first single water-soluble polymeric sealant layer at room temperature followed by water absorption into the first water-soluble polymeric layer at Line Laminating & Technology Center (Neuss). The resulting 1 µ dry layer had a composition of 100% of Coroset Sodium from BYK. The second water-dispersible nanoplatelet barrier sublayer was then added by roll-to-roll coating at room temperature of a 14 µ aqueous Coroset dispersion onto the first water-dispersible nanoplatelet barrier sublayer followed by removal of water by evaporation over a full week at Line Laminating & Technology Center (Neuss). The resulting 0.5 µ dry layer had a composition of 100% of Coroset Sodium from BYK. Finally, the multilayer structure was laminated at Line Laminating & Technology Center (Neuss) onto a recyclable 99 µ thickness paper grade of the inside sizing side as NiklaSelect V Natural Linen from Birgl & Bergmeister (B&B) coated with a 12 µ aqueous lamination layer composition. The water in the solution was absorbed into the paper. The resulting 5 µ dry lamination layer had a composition of 80% of Selvol 205 (from Sekisui Chemicals) and 20% of glycerol (from Cremer).

[0168] The following Table 3 provides the barrier properties (WVTR) for the above embodiments.

[0169] Table 3

[0170]

[0171] While the barrier performance from the water-dispersible nanoplatelet monolayer (Sample 1) is suitable for many recyclable paper-based flexible packaging applications, the barrier performance can be significantly improved by splitting the water-dispersible nanoplatelet monolayer into two sub-layers (Sample 2). Without being limited by theory, it is believed that the second sub-layer masks any potential defects present in the first sub-layer.

[0172] While the barrier performance of the water-dispersible nanoplatelet double sub-layer applied by extrusion coating (Sample 2) is suitable for many recyclable paper-based flexible packaging applications, the barrier performance can be significantly improved by applying the water-dispersible nanoplatelet double sub-layer via roll-to-roll coating (Sample 3). Without being limited by theory, it is believed that the enhanced shear of the roll-to-roll coating process causes the corundum nanoplatelets to better orient in the plane of the barrier layer, increasing the permeation length in the barrier layer and thus enhancing the barrier performance.

[0173] Table 4 provides the recyclability and biodegradability of the above embodiments.

[0174] Table 4

[0175]

[0176] Comparative Example

[0177] A. Non-recyclable paper barrier laminate based on paper, polyvinyl alcohol, and beeswax

[0178] Preparation of the sealant layer composition

[0179] Polyvinyl alcohol flake (Selvol 205 from Sekisui Chemicals) and sorbitol solution (E420 USP / FCC grade from Archer Daniels Midland, 71% D-sorbitol content in water) were pumped into a CT-25 twin-screw compounder (from Baker & Perkins, Saginaw, Michigan, USA) with an L / D ratio of 52 and a co-rotating screw speed of 340 rpm and a build temperature of 25°C (inlet), 170°C (melt and metering zone) and 150°C (extrusion die). Water was added as a processing aid and removed via a vacuum pump to essentially produce a water-free polymer strand. The strand was air-cooled and chopped to produce pellets of an 80% PVOH and 20% sorbitol composition. Separately, polyvinyl alcohol flake (Selvol 205 from Sekisui Chemicals), glycerol (GL 99.7 USP grade from Peter Cremer Oleo Division) and silicate anti-block particles (Sipernat® 820 Grade A from Evonik Industries AG, Essen, Germany) were compounded by a similar procedure to produce pellets of a 74% PVOH, 20% glycerol and 6% anti-blocker composition.

[0180] As a next step, 50% by weight of each of the pellets from the two batches were dosed into the barrel of an extruder of a pilot-scale cast film production line with an L / D ratio of 30 and a single 30 mm diameter screw designed for PE blends. The screw rotation speed was set to 30 rpm and the extruder barrel temperature was set to 25°C (inlet), 200°C (melt and metering zone) and 195°C (extrusion die). The polymer melt extruded from the slit die was cooled on a chill roll and calendered to produce a 20 pm thick film of a 77% PVOH, 10% glycerol, 10% sorbitol and 3% anti-block composition. The film was rewound into a film roll under constant tension control.

[0181] Preparation of barrier layer composition

[0182] Beeswax (white beeswax) off-white ingot grade 442 was obtained from Strahl & Pitsch (West Babylon, New York, USA) and used as received. The melting point was in the range of 62°C to 65°C.

[0183] Preparation of recyclable paper barrier laminates based on paper, polyvinyl alcohol and beeswax

[0184] The less glossy side of one A4 format paper of the paper grade packaging Pro 7.0 provided by Brigl & Bergmeister (Niklasdorf, Austria) 80 g / m2was hot laminated on one A4 format sheet of the 20 pm thick PVOH film as described in the sealing layer composition paragraph above. The lamination step was performed using a lab scale equipment model 480R6 professional laminator from Sky DS B (Seoul, South Korea) with a temperature of 140 °C and a feed speed of 575 mm / min (setting 3 out of 1 to 6, while the maximum setting 6 corresponds to 1150 mm / min).

[0185] As a next step, the paper lamination sheet of A4 format was coated with beeswax on the face of the brighter, larger format Pack Pro 7.0 paper. For this, the lab scale equipment model C-14 adhesive wax coater from Schaefer Machine Company (Clinton, Connecticut, USA) was modified by replacing the original blade with different diameter of the Mayer bar, enabling different melt wax coating thicknesses. The temperature of the melt wax in the hole was set to 90 °C.

[0186] The following table 5 provides the barrier properties (WVTR) of the above described embodiments.

[0187] Table 5

[0188]

[0189] While the 12 g / m2beeswax coated paper is below the requirements for many moisture sensitive solid products, the 20 g / m2beeswax coated paper is surprisingly close to the moisture barrier of the previously described example sample 1. 2 The moisture barrier of the beeswax coated paper is surprisingly close to the moisture barrier of the previously described example sample 1. 2 The moisture barrier of the beeswax coated paper is surprisingly close to the moisture barrier of the previously described example sample 1.

[0190] However, the problem with applying beeswax to paper is the trade-off between the desired moisture penetration barrier layer and the desired paper recyclability. As shown in the following table 6, all produced comparative examples did not pass the PTS recyclability test, the main problem being that wax spots were detected as unacceptable optical defects, although the recyclable fiber content was high.

[0191] Table 6

[0192]

[0193] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

[0194] Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any application disclosed or claimed herein or that it alone, or along with any other document or matter, teaches, suggests or discloses any such application. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall control.

[0195] While particular embodiments of the present application have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the application. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this application.

Claims

1. A recyclable paper barrier laminate comprising: a) a recyclable paper layer having an outer surface and an inner surface b) a first water-soluble polymer layer having an outer surface and an inner surface, the outer surface disposed on the inner surface of the paper layer c) a water-dispersible barrier layer having an outer surface and an inner surface, the outer surface disposed on the inner surface of the water-soluble polymer layer, the water-dispersible barrier layer comprising 90% to 100% hydrophilic nanoplatelets, and the water-dispersible barrier layer having a thickness of 0.1 pm to 20 pm d) a second water-soluble polymer layer having an outer surface and an inner surface, the outer surface disposed on the inner surface of the water-dispersible barrier layer wherein "water-dispersible" means breaking into small pieces of less than 1 millimeter in water, wherein the first water-soluble polymer layer and the second water-soluble polymer layer each comprise at least one water-soluble polymer, and a polymer that requires more than 24 hours to dissolve in water at a temperature of 23 °C will not be considered water-soluble.

2. The recyclable paper barrier laminate of claim 1, wherein the recyclable paper barrier laminate has a grammage of 20 g / m 2 to 1000 g / m 2 .

3. The recyclable paper barrier laminate according to claim 1 or 2, wherein the WVTR of the recyclable paper barrier laminate is 0.1 g / m³ when measured according to ASTM method F1249-13 at a temperature of 40°C and a relative humidity of 50%. 2 / 100g / m 2 / sky.

4. The recyclable paper barrier laminate according to claim 1 or 2, wherein the WVTR of the recyclable paper barrier laminate is 0.1 g / m³ when measured according to ASTM method F1249-13 at a temperature of 38°C and a relative humidity of 90%. 2 / 200g / m 2 / sky.

5. The recyclable paper barrier laminate according to claim 1 or 2, wherein the WVTR of the recyclable paper barrier laminate is 0.1 g / m³ when measured according to ASTM method F1249-13 at a temperature of 40°C and a relative humidity of 50%. 2 / 200g / m 2 / day, even after experiencing mechanical stress.

6. The recyclable paper barrier laminate of claim 1 or 2, wherein the recyclable paper barrier laminate biodegrades at least 60% within 60 days in the OECD 301B test.

7. The recyclable paper barrier laminate of claim 1 or 2, wherein the paper barrier laminate is recyclable and exhibits a recyclability percentage of at least 50% as determined by test method PTS-RH:021 / 97.

8. The recyclable paper barrier laminate of claim 1 or 2, wherein the paper barrier laminate is recyclable and exhibits an overall "pass" result as determined by test method PTS-RH:021 / 97.

9. The recyclable paper barrier laminate of claim 1 or 2, wherein the recyclable paper barrier laminate comprises 50% to 100% by weight of natural fibers.

10. The recyclable paper barrier laminate of claim 1, wherein the recyclable paper comprises natural fibers, the natural fibers comprising cellulose-based fibers.

11. The recyclable paper barrier laminate of claim 1, wherein the recyclable paper comprises natural fibers, the natural fibers comprising at least one of bamboo fibers, cotton, abaca, kenaf, broussonetia papyrifera, flax, miscanthus, rice straw, jute, hemp fibers, bagasse, milkweed floss fibers, pineapple leaf fibers, wood fibers, pulp fibers, or combinations thereof.

12. The recyclable paper barrier laminate of claim 1 or 2, wherein the water-soluble polymer layer has an average thickness of 1 pm to 200 pm.

13. The recyclable paper barrier laminate of claim 1 or 2, wherein the water-soluble polymer layer comprises at least one water-soluble polymer, the water-soluble polymer being at least one of polyvinyl alcohol, polyethylene oxide, methyl cellulose, or sodium alginate.

14. The water-soluble polymer layer of claim 13, wherein the water-soluble polyvinyl alcohol has an average molecular weight of 20,000 Da to 150,000 Da.

15. The water-soluble polymer layer of claim 13, wherein the water-soluble polyethylene oxide has an average molecular weight of 50,000 Da to 400,000 Da.

16. A method of making the recyclable paper barrier laminate of claim 1, comprising: a) applying a second aqueous solution of a water-soluble polymer composition to a surface of a removable flat carrier such as a PET film or steel belt b) removing water from the second aqueous solution of a water-soluble polymer composition to obtain a second water-soluble polymer layer c) applying an aqueous dispersion of hydrophilic nanoplatelets to an outer surface of the second water-soluble polymer layer d) removing water from the aqueous dispersion of hydrophilic nanoplatelets to obtain a water-dispersible barrier layer comprising 90% to 100% of the hydrophilic nanoplatelets, and a thickness of the water-dispersible barrier layer of 0.1 pm to 20 pm e) applying a first aqueous solution of a water-soluble polymer composition to an inner surface of the recyclable paper layer f) joining an outer surface of the water-dispersible barrier layer with the first aqueous solution of a water-soluble polymer composition g) removing water from the first aqueous solution of a water-soluble polymer composition to obtain a first water-soluble polymer layer h) removing the flat carrier from the resulting recyclable paper barrier laminate.

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