Water-soluble barrier film

Abstract

The present invention provides a water-soluble film comprising an integrated water-dispersible barrier that prevents any penetration.

Description

Technical Field

[0001] This invention relates to a water-soluble barrier membrane, which is used either as a stand-alone membrane for product applications (such as pods) or as a component membrane in a laminate for flexible packaging applications (such as pouches), having an integrated water-dispersible barrier that prevents any permeation, offering several advantages over prior art water-soluble membrane implementations; and this invention also relates to a method for preparing a water-soluble membrane having an integrated water-dispersible barrier that prevents any permeation. Background Technology

[0002] The use of water-soluble membranes in consumer products such as liquid detergent pods and dishwasher dry powder tablets is gaining increasing acceptance. For effectiveness, such water-soluble membranes must maintain their properties (strength, permeation barrier) when exposed to chemicals, and disperse or completely dissolve when immersed in water. Multi-compartment pods, marketed by P&G, enable the separation of chemicals in the top and bottom compartments via a water-soluble membrane placed flat in the middle of the pod. The water-soluble membrane must be thick enough to prevent chemical exchange between the top and bottom compartments or from external contaminants, and thin enough to completely dissolve in water during use.

[0003] Consumers have found that even if the capsules are not prematurely exposed to water or highly humid environments, they often become sticky over time. This is because some of the chemicals contained within the capsule migrate through the outer capsule membrane over time, as current soluble membranes offer little barrier against the liquid components held within the packaging. The barrier properties of current soluble membranes also cause other problems, such as the migration of chemicals between the compartments in multi-compartment packaging, making it difficult to separate reactive substances even if they are initially separated in different compartments. Over time, they will prematurely diffuse and react together before use, limiting the final performance of the entire product. Some examples of chemicals present in products where migration should be limited include: water, fragrances, surfactants, bleach, color dyes, and highly migratory sodium. + cations, Fe 2+ cation.

[0004] A common method for preparing water-soluble membranes is via solution casting. An example of a commercially available water-soluble membrane is the M8630 from MonoSol LLC (Gary, Indiana, USA). Other examples of commercially available water-soluble membranes include those from Aicell. Using this current technology, it is only possible to prepare water-soluble membranes as a single layer or monolayer. For those applications where barrier functionality is desired, the prior art selects to apply the barrier material on top of an already formed water-soluble membrane or to disperse the barrier material within the components of the water-soluble membrane. Patent application WO2007 / 027224 provides an example of a barrier material dispersed within the components of a water-soluble membrane. If the barrier material is applied on top of an already formed water-soluble membrane, the sealing ability of the water-soluble membrane on the coated surface is affected, or the barrier performance becomes negligible. If the barrier material is dispersed within the components of the water-soluble membrane, the solubility of the water-soluble membrane is affected, or the barrier performance becomes negligible. In both cases, the barrier performance must be balanced along with other important membrane properties, thus reducing the barrier performance.

[0005] Water-soluble membranes are also prepared via melt extrusion. This process can produce water-soluble multilayer membranes, provided that the rheological properties and interfacial energies between the different layers are substantially similar. For applications where barrier functionality is desired, existing techniques disperse the barrier material within the composition of the intermediate layer of the water-soluble membrane. Again, in this case, water solubility and barrier properties must be balanced, thus reducing barrier performance.

[0006] Therefore, there remains an unmet need for water-soluble films and packaging made therefrom (such as pouches and sachets) that provide improved barrier properties when exposed to vapors and dissolve or disperse sufficiently quickly into sufficiently small particles upon immersion in or exposure to water (such as rinse or wash water). "Sufficiently small" and "sufficiently fast" depend on the specific product application. For single unit dose (SUD) products, the required time will be less than a washing machine cycle. For packaging for shower body or shampoo products, this time is less than an average shower time, and for packaging that may eventually be discarded, it is less than a day. Dispersion should be achieved to the extent that the material is compatible with the drainage system without impairing product performance. Therefore, one aspect of the invention is to provide a water-soluble film that provides improved barrier properties against the diffusion of unwanted chemicals (even water vapor) before full immersion in water, and subsequently dissolves or disperses substantially upon immersion in water (such as rinse or wash water). Summary of the Invention

[0007] A water-soluble membrane with an integrated water-dispersible barrier is provided. The water-soluble membrane includes: a first water-soluble polymer layer having a planar surface; a second water-soluble polymer layer having a planar surface; and a water-dispersible barrier layer disposed between the first water-soluble polymer layer and the second water-soluble polymer layer.

[0008] A method for fabricating a water-soluble membrane is provided, the method comprising: applying a first aqueous solution of a water-soluble polymer composition to the surface of a removable flat carrier (such as a PET film or steel strip); 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 nanosheets to the surface of the first water-soluble polymer layer; removing water from the aqueous dispersion of the hydrophilic nanosheets to obtain a water-dispersible barrier layer; applying a second aqueous solution of the water-soluble polymer composition to the surface of the water-dispersible barrier layer; removing water from the second aqueous solution of the water-soluble polymer composition to obtain a second water-soluble polymer layer; and removing the flat carrier from the resulting water-soluble barrier membrane. Attached Figure Description

[0009] Figure 1 A cross-section of the water-soluble polymer layer is shown.

[0010] Figure 2 A cross-section of a water-dispersible nanosheet layer coated on a water-soluble polymer layer is shown.

[0011] Figure 3 A cross-section of a water-soluble membrane with an integrated water-dispersible barrier is shown.

[0012] Figure 4 A cross-sectional image obtained by scanning electron microscopy via a water-soluble membrane with an integrated water-dispersible barrier is shown.

[0013] Figure 5 A schematic diagram of a method for fabricating a water-soluble membrane with an integrated water-dispersible barrier is shown.

[0014] Figure 6 A schematic diagram of the application of a water-soluble membrane with an integrated water-dispersible barrier is shown. Detailed Implementation

[0015] This invention describes a water-soluble membrane having an integrated water-dispersible barrier that prevents water vapor permeation, offering several advantages over prior art water-soluble membranes; and a method for manufacturing a water-soluble membrane having an integrated water-dispersible barrier layer.

[0016] As used herein, the term “water vapor transport rate” or “WVTR” refers to the rate at which water vapor is transported through the membrane when measured according to the water vapor transport test method described in the Test Methods section.

[0017] As used herein, the term "dissolution time" refers to the time required for a water-soluble membrane (such as a membrane made of polyvinyl alcohol) to dissolve when measured according to the dissolution test method described in the Test Methods section.

[0018] As used in this article, the term "water dispersibility" refers to the ability to break down into small fragments smaller than one millimeter in water. These fragments can, but do not need to, remain stably suspended in water.

[0019] As used herein, the term "copolymer" refers to a polymer formed from two or more repeating monomer units of different types. 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 butenediol monomer units; however, if the copolymer is substantially completely hydrolyzed, the vinyl acetate monomer units may be substantially absent.

[0020] As used herein, the term “degree of hydrolysis” refers to the molar percentage of vinyl acetate units that are converted into vinyl alcohol units when polymerized vinyl alcohol is hydrolyzed.

[0021] As used herein, when the term “about” modifies a particular value, it means a range equal to the particular value plus or minus twenty percent (±20%). For any of the embodiments disclosed herein, in various alternative embodiments, any disclosure of a particular value may also be understood as approximately equal to the disclosed range of that particular value (i.e., ±20%).

[0022] As used herein, when the term “approximately” modifies a particular value, the term means a range equal to the particular value plus or minus fifteen percent (±15%). For any embodiment of the embodiments disclosed herein, in various alternative embodiments, any disclosure of a particular value may also be understood as approximately equal to the disclosed range of that particular value (i.e., ±15%).

[0023] As used herein, when the term “substantially” modifies a particular value, it means a range equal to the particular value plus or minus ten percent (±10%). For any of the embodiments disclosed herein, in various alternative embodiments, any disclosure of a particular value may also be understood as approximately equal to the disclosed range of that particular value (i.e., ±10%).

[0024] As used herein, when the term “almost” modifies a particular value, it means a range equal to the particular value plus or minus five percent (±5%). For any of the embodiments disclosed herein, in the various alternative embodiments, any disclosure of a particular value may also be understood as approximately equal to the disclosed range of that particular value (i.e., ±5%).

[0025] Figure 1 A cross-section of the water-soluble polymer layer 10 is shown. The water-soluble polymer layer 10 has a first surface 12 and a second surface 14 opposite to the first surface 12, and a thickness 16 between the first surface 12 and the second surface 14.

[0026] The thickness of the water-soluble polymer layer 10 between the first surface 12 and the second surface 14 can be in the range of about 1 μm to about 1000 μm, preferably about 10 μm to about 250 μm, and more preferably about 25 μm to about 125 μm.

[0027] The water-soluble polymer layer 10 includes at least one water-soluble polymer. Depending on the application, the water-soluble polymer may be selected from the available options to dissolve in water at 23°C within seconds, minutes, or hours. Polymers that require more than 24 hours to dissolve in water at 23°C will not be considered water-soluble.

[0028] Figure 2 A cross-section of a water-dispersible barrier layer 20 is shown, the barrier layer having a first surface 22 and a second surface 24 opposite to the first surface 22, and a thickness 18 between the first surface 22 and the second surface 24, the barrier layer being applied to substantially cover at least one of the first surface 12 or the second surface 14 of the water-soluble polymer layer 10.

[0029] The thickness of the water-dispersible barrier layer 20 is in the range of about 0.1 μm to about 20 μm, preferably about 0.1 μm to about 10 μm, and more preferably about 0.1 μm to about 5 μm.

[0030] The water-dispersible barrier layer 20 comprises 90% to 100% nanosheets, more preferably 96% to 100% nanosheets, and even more preferably 99% to 100% nanosheets, such as sodium cloisite or sodium hectorite, and is substantially free of other materials, such as binders, dispersants, surfactants, or water-soluble polymers, in the gaps between the assembled nanosheets. This means that the cohesion of the nanosheet layer is provided solely by the interactions between the nanosheets, and the adhesion to the water-soluble polymer layer is provided solely by the interactions between the nanosheets and the water-soluble polymer. The absence of a binder (gap filler) in the nanosheet layer maximizes the barrier performance of the nanosheet layer against water penetration, while maintaining the dispersibility of the hydrophilic nanosheets in water when the top / bottom water-soluble polymer layers are removed during use by dissolving in water. Nanosheets that require more than 24 hours to disperse in water at 23°C are not considered dispersible in water.

[0031] Nanosheets are plate-like nanoparticles characterized by a high aspect ratio between their diameter and orthogonal height. This high aspect ratio enables the formation of “brick walls” where nanosheets are laid parallel to the surface of an underlying water-soluble polymer layer, overlapping and resting on top of each other, thus significantly reducing the migration of molecules (both gaseous and liquid) through the nanosheet layers. The higher the aspect ratio, the greater the barrier properties achievable. Typical aspect ratios for montmorillonite exfoliated nanosheets are around 100 or greater (Cadène et al., JCIS 285(2):719-30, June 2005).

[0032] The water-dispersible barrier layer 20 according to the invention can be optically opaque, preferably translucent, or even more preferably transparent, depending on the nanosheet material (peeling level, impurity level) and the nanosheet application process.

[0033] Preferably, the water-dispersible barrier layer 20 is flexible and stretchable. When the water-soluble film according to the invention is processed through a production line for printing, pressing, cutting, rewinding, and other typical conversion operations to produce articles such as pouches, the water-soluble film according to the invention can be stretched by up to 200%. This can cause the water-dispersible barrier layer 20 to break. Therefore, it is preferable that the water-dispersible barrier layer 20 is flexible and stretchable without breaking. Preferably, the water-dispersible barrier layer 20 can be stretched by at least 20%, more preferably at least 30%, even more preferably at least 50%, and most preferably at least 100% and up to 200% without breaking.

[0034] Figure 3 A cross-section of a water-soluble membrane 100 having an integrated water-dispersible barrier, including a first water-soluble polymer layer 10, is shown. The water-soluble polymer layer 10 has a first surface 12 and a second surface 14 opposite to the first surface 12, and a thickness 16 between the first surface 12 and the second surface 14. The water-soluble polymer layer 10 may be in the form of a film or a sheet. A barrier layer 20 having a first surface 22 and a second surface 24 opposite to the first surface 22, and a thickness 18 between the first surface 22 and the second surface 24, is applied to and substantially covers at least one of the first surface 12 or the second surface 14 of the water-soluble polymer layer 10. A second water-soluble polymer layer 30, having a first surface 112 and a second surface 114 opposite to the first surface 112, and a thickness 116 between the first surface 112 and the second surface 114, is applied such that the second surface of the water-soluble polymer layer substantially covers at least one of the first surface 22 or the second surface 24 of the water-dispersible barrier layer 20. The water-soluble polymer layer 30 may be in the form of a film or a sheet. The adhesion between the layers is provided by the interaction between the water-soluble polymer and the hydrophilic nanosheets.

[0035] The thickness of the water-soluble polymer layer 30 between the first surface 112 and the second surface 114 can be in the range of about 1 μm to about 1000 μm, preferably about 10 μm to about 250 μm, and more preferably about 25 μm to about 125 μm.

[0036] The water-soluble polymer layer 30 includes at least one water-soluble polymer. Depending on the application, the water-soluble polymer may be selected from the available options to dissolve in water at 23°C within seconds, minutes, or hours. Polymers that require more than 24 hours to dissolve in water at 23°C will not be considered water-soluble.

[0037] Each layer according to the invention is distinct and separate from the other layers. The term "distinct layer" refers to the barrier layer 20 within the water-soluble film 100, which essentially comprises only nanosheets, and the boundary between the barrier layer 20 and the surrounding water-soluble polymer layers 10 and 30 is distinguished by a large compositional variation over a small distance, resulting in a clear boundary easily visible using microscopy techniques known in the art. The boundary layer, i.e., the intermediate layer of the intermediate composition between the water-dispersible nanosheet layer and the adjacent water-soluble polymer layer, is no more than 2 μm thick, and this is visible using microscopy techniques known in the art.

[0038] When the water-soluble membrane according to the invention is immersed in water (i.e., in applications where the water-soluble membrane needs to disappear in water), the water-soluble polymer layer surrounding and supporting the nanosheet barrier layer dissolves in the water, the barrier layer breaks down, and the nanosheets disperse in the water, thus enabling the entire membrane to disappear in the water.

[0039] The water-soluble film including a water-dispersible barrier layer according to the present invention can be opaque, preferably translucent, or even more preferably transparent, depending on the material.

[0040] The water-soluble film according to the invention may include a printing area. Printing can be achieved using standard printing techniques such as flexographic printing, gravure printing, or inkjet printing.

[0041] Water-soluble polymers

[0042] Preferred polymers, copolymers, or derivatives thereof suitable for use as water-soluble polymer layers are selected from polyvinyl alcohol (PVOH), polyvinyl alcohol copolymers (such as butene glycol-vinyl alcohol copolymer (BVOH)), which are produced by copolymerization of butene glycol with vinyl acetate followed by hydrolysis of vinyl acetate. Suitable butene glycol monomers are selected from 3,4-diol-1-butene, 3,4-diacoxy-1-butene, 3-acyloxy-4-ol-1-butene, 4-acyloxy-3-ol-1-butene, etc.; polyvinylpyrrolidone; polyepoxides, such as polyethylene oxide or polyethylene glycol (PEG); poly(methacrylic acid), polyacrylic acid Polyacrylates, acrylate copolymers, maleic acid / acrylic acid copolymers; polyacrylamide; poly(2-acrylamido-2-methyl-1-propanesulfonic acid (polyAMPS); polyamides, poly-N-vinylacetamide (PNVA); polycarboxylic acids and salts; cellulose derivatives, such as cellulose ethers, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose; hydroxypropyl methylcellulose; 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 caseinates (e.g., those commercialized by Lactips).

[0043] The most preferred polymers are polyvinyl alcohol, polyethylene oxide, methylcellulose, and sodium alginate. For applications where a "plastic-free" product is desired, the majority of the components of the water-soluble polymer layer can be naturally derived polymers, such as sodium alginate. Preferably, the polymer content in the water-soluble polymer layer is at least 60%.

[0044] The average molecular weight (measured by gel permeation chromatography) of the water-soluble polymer is from about 1,000 Da to about 1,000,000 Da, or any integer value from about 1,000 Da to about 1,000,000 Da, or any range formed by any of the foregoing values, such as from about 10,000 Da to about 300,000 Da, from about 20,000 Da to about 150,000 Da, etc. More specifically, the molecular weight of polyvinyl alcohol will be in the range of 20,000 Da to 150,000 Da. The molecular weight of polyethylene oxide will be in the range of 50,000 Da to 400,000 Da. The molecular weight of methylcellulose will be in the range of 10,000 Da to 100,000 Da. Methylcellulose may be methoxylated, for example from about 18% to about 32%, and may be hydroxy-propoxy substituted, for example from about 4% to about 12%. Sodium alginate has a molecular weight in the range of 10,000 Da to 240,000 Da.

[0045] If homopolymer polyvinyl alcohol is used, the degree of hydrolysis can be 70% to 100%, or any integer percentage 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%, etc.

[0046] Optional ingredients

[0047] The water-soluble polymer layer of a water-soluble membrane with an integrated water-dispersible barrier may contain disintegrants, plasticizers, surfactants, lubricants / stripping agents, fillers, extenders, antiblocking agents, anti-sticking agents, defoamers, or other functional ingredients. In the case of articles comprising compositions for washing, the water-soluble polymer layer may include functional detergent additives to be delivered to the wash water, such as organic polymer dispersants or other detergent additives.

[0048] For certain applications, the water-soluble polymer layer may need to contain a disintegrant to increase the dissolution rate of the water-soluble membrane with integrated water-dispersible barrier in water. Suitable disintegrants are, but are not limited to, corn / potato starch, methylcellulose, mineral clay powder, cross-linked carboxymethyl cellulose (cross-linked cellulose), cross-linked polyvinyl N-pyrrolidone (cross-linked polyvinyl N-pyrrolidone or PVP), and sodium carboxymethyl starch (cross-linked starch). Preferably, the water-soluble polymer layer contains between 0.1% and 15% by weight, more preferably about 1% to about 15% by weight of the disintegrant.

[0049] Preferably, the water-soluble polymer layer may comprise a water-soluble plasticizer. Preferably, the water-soluble plasticizer is selected from water, polyols, sugar alcohols, and mixtures thereof. Suitable polyols include those selected from the group consisting of: glycerol, diglycerol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol with a molecular weight of up to 400 Da, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol, methyl glycol, trimethylolpropane, hexanediol, neopentyl glycol, and polyether polyols, or mixtures thereof. Suitable sugar alcohols include those selected from the group consisting of: isomaltitol, maltitol, sorbitol, xylitol, erythritol, ribitol, galactitol, pentaerythritol, and mannitol, or mixtures thereof. In some cases, plasticizers may be selected from the following list: ethanolamine, alkyl citrate, isosorbide, pentaerythritol, glucosamine, N-methylglucosamine, or sodium isopropylbenzenesulfonate. Less mobile plasticizers such as sorbitol or polyethylene oxide can promote the formation of water-soluble polymer layers with greater barrier properties compared to water-soluble polymer layers containing more mobile plasticizers such as glycerol. In some cases, when it is desirable to use as many naturally derived materials as possible, the following plasticizers may also be used: vegetable oils, polysorbate, polydimethylsiloxane, mineral oil, paraffin wax, C1-C3 alcohols, dimethyl sulfoxide, N,N-dimethylacetamide, sucrose, corn syrup, fructose, sodium dioctyl sulfosuccinate, triethyl citrate, tributyl citrate, 1,2-propanediol, monoacetates, diacetates, or triacetates of glycerol, natural gums, citrates, and mixtures thereof. More preferably, the water-soluble plasticizer is selected from glycerol, 1,2-propanediol, 2,0-dipropanediol, 2-methyl-1,3-propanediol, trimethylolpropane, triethylene glycol, polyethylene glycol, sorbitol, or mixtures thereof, most preferably from glycerol, sorbitol, trimethylolpropane, dipropanediol, and mixtures thereof. Preferably, the water-soluble polymer layer contains 5% to 50% by weight, more preferably between 10% and 40% by weight, and even more preferably about 12% to about 30% by weight of the plasticizer.

[0050] Preferably, the water-soluble polymer layer according to the invention comprises a surfactant. Suitable surfactants may belong to the nonionic, cationic, anionic, or amphoteric categories. Suitable surfactants are, but are not limited to, poloxamer (polyoxyethylene polyoxypropylene glycol), alcohol ethoxylates, alkylphenol ethoxylates, tertiary acetylenols and alkanolamides (nonionic), polyoxyethylene amines, quaternary ammonium salts and polyoxyethylene quaternary amines (cationic), and amine oxides, N-alkyl betaine and sulfobetaine (amphoteric). Other suitable surfactants are sodium dioctyl sulfosuccinate, lactated fatty acid esters of glycerol and propylene glycol, fatty acid lactyl esters, sodium alkyl sulfate, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, lecithin, acetylated fatty acid esters of glycerol and propylene glycol, and acetylated esters of five fatty acids and combinations thereof. Preferably, the water-soluble polymer layer comprises between 0.1% and 2.5% by weight, more preferably about 1% to about 2% by weight of surfactant.

[0051] Preferably, the water-soluble polymer layer according to the invention comprises a lubricant / stripping agent. Suitable lubricants / stripping 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 / stripping agents are fatty acids, fatty acid salts, fatty amine acetates, and mixtures thereof. Preferably, the water-soluble polymer layer contains between 0.02% by weight and 1.5% by weight, more preferably about 0.1% by weight and about 1% by weight of the lubricant / stripping agent.

[0052] Preferably, the water-soluble polymer layer according to the invention comprises a filler, a bulking agent, an anti-blocking agent, and a non-sticking agent. Suitable fillers, bulking agents, anti-blocking agents, and non-sticking agents are, but are not limited to, starch, modified starch, cross-linked polyvinylpyrrolidone, cross-linked cellulose, microcrystalline cellulose, silica, metal oxides, calcium carbonate, talc, and mica. Preferably, the water-soluble polymer layer comprises between 0.1% by weight and 25% by weight, more preferably between about 1% by weight and about 15% by weight, of the filler, bulking agent, anti-blocking agent, and non-sticking agent. In the absence of starch, the water-soluble polymer layer comprises preferably between 1% by weight and 5% by weight of the filler, bulking agent, and anti-blocking agent.

[0053] Preferably, the water-soluble polymer layer according to the invention comprises an antifoaming agent. Suitable antifoaming agents are, but are not limited to, blends of polydimethylsiloxane and hydrocarbons. Preferably, the water-soluble polymer layer contains between 0.001% and 0.5% by weight, more preferably about 0.01% to about 0.1% by weight of the antifoaming agent.

[0054] Beneficial agents can also be incorporated into the water-soluble polymer layer. Therefore, it is possible to deliver beneficial agents incompatible with the product or composition within the article (such as a pouch) via the article itself. Examples of beneficial agents include, but are not limited to, detergents, dirt suspending agents, anti-redeposition agents, optical brighteners, bleaching agents, enzymes, fragrance compositions, bleaching activators and precursors, brighteners, antifoaming agents, fabric care compositions, and surface nourishing compositions.

[0055] Bittering agents can also be incorporated into the water-soluble polymer layer, which is legally required in some regions for certain applications (such as pods). Suitable bittering agents are, but are not limited to, naringin, sucrose octaacetate, quinine hydrochloride, denaphalonamine, or mixtures thereof. Preferably, the water-soluble polymer layer contains a bittering agent in amounts between 1 ppm and 5000 ppm by weight, more preferably about 100 ppm to about 2500 ppm, and even more preferably about 250 ppm to about 2000 ppm by weight.

[0056] The water-soluble film or water-soluble article according to the present invention may be coated with an anti-blocking agent / anti-sticking agent. Suitable anti-blocking agents / anti-sticking agents are, but are not limited to, talc, zinc oxide, silicon dioxide, siloxane, zeolite, silicic acid, alumina, sodium sulfate, potassium sulfate, calcium carbonate, magnesium carbonate, sodium citrate, sodium tripolyphosphate, potassium citrate, potassium tripolyphosphate, calcium stearate, zinc stearate, magnesium stearate, starch, modified starch, clay, kaolin, gypsum, cyclodextrin, or mixtures thereof.

[0057] The water-soluble membrane according to the invention may contain residual moisture, depending on the hygroscopicity of the water-soluble membrane components and the isotherm of the water-soluble membrane measured by Karl Fischer titration under given temperature and humidity conditions. For example, a water-soluble polyvinyl alcohol membrane may contain about 4% to 8% residual moisture at 23°C and 50% relative humidity.

[0058] Water-dispersible nanosheets

[0059] Nanosheets are solid, plate-like nanoparticles characterized by a high aspect ratio between their diameter and orthogonal height. This high aspect ratio enables the parallel alignment of the nanosheets and a longer diffusion path for chemicals, thus achieving barrier functionality. Nanosheets are expected to be free from defects that reduce barrier performance, such as cracks and pores. They are also expected to be easily exfoliated in water for application purposes (e.g., wet coatings) and end-of-life scenarios (e.g., wastewater treatment plants), but highly cohesive when dried. Nanosheets are currently used in industry as rheology modifiers, flame retardants, anti-corrosion coatings, and / or chemical barriers. Nanosheets can be obtained from natural sources and used as is, or purified and modified from natural sources, or synthesized in a furnace for purity and performance reasons.

[0060] 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. Montmorillonites such as montmorillonite and lithium montmorillonite consist of stacked nanosheets that swell most in the presence of water. Natural montmorillonites can be purified and modified, such as sodium crosothiate from BYK, obtained from bentonite (a natural mineral containing 60% to 80% montmorillonite), and subjected to cation exchange with monovalent sodium for exfoliation purposes. Montmorillonites 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 oxide, such as those provided by Applied Graphene Materials, and are also characterized by a high aspect ratio between their diameter and orthogonal height.

[0061] Methods for producing water-soluble barrier membranes

[0062] Numerous non-limiting embodiments exist for fabricating the water-soluble membrane with integrated water-dispersible barrier as described herein. For example... Figure 5 As shown, a water-soluble membrane with an integrated water-dispersible barrier can be prepared under specific conditions through multiple steps of coating and drying of an aqueous polymer solution or an aqueous nanosheet dispersion.

[0063] In one non-limiting embodiment of the method, a water-soluble polymer layer 10 is formed on the surface of a flat carrier (e.g., an untreated PET film, stainless steel strip, fluoropolymer strip, or any other suitable carrier material); a water-dispersible nanosheet layer 20 is formed on at least one of the surfaces 12, 14 of the previously formed water-soluble polymer layer 10; then, a second water-soluble polymer layer 30 is formed on at least one of the surfaces 112, 114 of the previously formed water-dispersible nanosheet layer; finally, the flat carrier is removed from the resulting water-soluble barrier film.

[0064] To produce the water-soluble polymer layers 10 or 30, the aqueous polymer solution is typically formed as follows: a water-soluble polymer in solid form is taken and first dissolved in water using moderate stirring; typically, 20% by weight of the water-soluble polymer corresponds to 80% by weight of water. The aqueous polymer solution is then further combined with other additives, such as plasticizers, at high temperature by moderate stirring. The aqueous polymer solution is then coated onto a flat surface carrier (e.g., untreated PET film, stainless steel strip, fluoropolymer strip, or any other suitable material), and the water is removed via a convection or diffusion drying process.

[0065] Unrestricted by theory, the most important material properties of aqueous polymer solutions are believed to be: a) the solubility of the polymer in water at a given temperature between 20°C and 95°C; b) the viscosity of the aqueous polymer solution at that temperature, with higher viscosity being better for maximizing the difference / separation between layers; and c) the wetting of the aqueous polymer solution on a flat carrier, or on a water-dispersible nanosheet layer, or on another water-soluble polymer layer, with higher wetting being better.

[0066] The drying step is typically performed using a conveyor dryer, such as by... Those sold under the trademark Drytec, those sold by Coatema under the trademark ModulDry, and / or those sold by FMP Technologies GmbH (Erlangen, Germany) under the trademarks SenDry or PureDry. In some embodiments, the substrate to be dried is guided through a hot air channel by a running belt (belt dryer), by multiple idlers (rolling dryer), or by multiple hot air nozzles (non-contact dryer). Without being theoretically limited, the most important parameters of the drying process are believed to be: the residence time of the substrate in the hot air channel, typically about 50 s for a 60 μm thick aqueous polymer solution containing 25% solids; the temperature of the hot air, typically about 95°C; and the velocity of the hot air flowing over the substrate, typically about 25 m / s. The heating system can be based on electricity, hot oil, steam, or gas.

[0067] To prepare the water-dispersible nanosheet layer 20, the aqueous nanosheet dispersion is typically formed as follows: Water-dispersible nanosheets in solid form are taken and first exfoliated with some water under high shear (e.g., high-energy ball milling), typically 80 wt% of the water-dispersible nanosheets corresponding to 20 wt% of water. The aqueous nanosheet dispersion is then further diluted in water by vigorous stirring at a moderate temperature. The aqueous nanosheet dispersion is then coated onto a first water-soluble polymer layer, and the water is then removed by drying.

[0068] Unrestricted by theory, the most important material properties of nanosheets are believed to be: a) the aspect ratio of the nanosheets (a higher aspect ratio is better for barrier performance); b) complete exfoliation and dispersion of the nanosheets in water under intense shear mixing, with no re-agglomeration, thus allowing for a substantially homogeneous coating of uniformly distributed nanosheets, resulting in a homogeneous coating free of defects such as pinholes or cracks. Unrestricted by theory, the most important processability properties of aqueous nanosheet dispersions are also believed to be: the viscosity of the aqueous nanosheet dispersion, with higher viscosity being better for maximum differentiation / separation between layers, and therefore better for maximum barrier performance; wetting of the aqueous nanosheet dispersion on a layer of water-soluble polymer or on another layer of water-dispersible nanosheets; shear applied to the aqueous nanosheet dispersion, with higher shear being better for parallel nanosheet orientation relative to the barrier plane; and water removal from the dispersion via diffusion drying without generating defects in the nanosheet layers.

[0069] Many processes for coating aqueous nanosheet dispersions were tested: wire rod coating, anilox roller coating, reverse roller coating, slot die extrusion coating, roll-to-roll coating, and spray coating. Aqueous extrusion coating via a custom slot die (e.g., FMP Technology, Coatema) proved to be the most reliable process with proper feeding of the aqueous nanosheet dispersion, while roll-to-roll processes achieved optimal barrier properties through the excellent shear of the aqueous nanosheet dispersion and thus through the excellent parallel orientation of the nanosheets. Nevertheless, this barrier property also depends on the overall thickness of the aqueous nanosheet layer. Typically, the thickness of the aqueous nanosheet layer is in the range of 1 μm to 10 μm to provide sufficient barrier properties while maintaining adequate mechanical flexibility and mechanical resistance.

[0070] In another non-limiting embodiment, the water-dispersible nanosheet barrier layer 20 is obtained through multiple application steps of coating and drying the aqueous nanosheet dispersion, each nanosheet sublayer masking hypothetical defects in the underlying nanosheet sublayer, thus achieving maximum barrier performance. For this purpose, a first water-dispersible nanosheet barrier sublayer is formed on a water-soluble polymer layer 10 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. According to this method, a relatively thick water-dispersible nanosheet layer can be formed. Additional water-dispersible nanosheet barrier sublayers can be separated by additional thin water-soluble polymer sublayers when improved optical transparency and mechanical flexibility are desired. Various polymers or barrier sublayers may have substantially the same chemical composition or different chemical compositions to achieve different properties for the overall structure. Adhesion between sublayers is provided solely by molecular interactions between the water-soluble polymer and the hydrophilic nanosheets. Similarly, cohesion between water-dispersible nanosheet barrier sublayers is provided solely by molecular interactions between the water-dispersible nanosheets, without the use of adhesives. The absence of adhesives maximizes the barrier performance against water penetration and maintains the dispersibility of nanosheets in water when the top / bottom polymer layers are dissolved.

[0071] Methods for making water-soluble products

[0072] The water-soluble films with integrated water-dispersible barrier elements described herein can be formed into articles, including but not limited to those in which the water-soluble films with integrated water-dispersible barrier elements are used as packaging materials. Such articles include, but are not limited to, water-soluble pouches, bags, and other containers. Water-soluble pouches and other such containers incorporating the water-soluble films with integrated water-dispersible barrier elements described herein can be manufactured in any suitable manner known in the art. The water-soluble films with integrated water-dispersible barrier elements can be provided before or after they are formed into the final articles. In either case, in some embodiments, when manufacturing such articles, it is desirable that the surface of the water-soluble polymer layer on which the barrier layer is applied forms the outer surface of the article.

[0073] There are many processes for producing water-soluble articles. These include, but are not limited to, processes known in the art, such as: vertical forming-fill-seal processes, horizontal forming-fill-seal processes, and forming pouches in molds on the surface of a circular drum. In the vertical forming-fill-seal process, a vertical tube is formed by folding a substrate. The bottom end of the tube is sealed to form an open pouch. The pouch is partially filled, allowing top space. The top parts of the open pouch are then sealed together to close the pouch and form the next open pouch. The first pouch is then cut, and the process is repeated. Pouches formed in this manner typically have a pillow block shape. The horizontal forming-fill-seal process uses a die head in which a series of molds are formed. In the horizontal forming-fill-seal process, a substrate is placed in the die head and an open pouch is formed in these molds, which can then be filled, covered with another layer of substrate, and sealed. In a third process (forming pouches in molds on the surface of a circular drum), the substrate is circulated on the drum to form pouches, which pass under a filling machine to fill open pouches. Filling and sealing occur at the highest point (top) of the circle drawn by the drum; typically, filling is completed just before the drum begins its downward circumferential movement, and sealing is completed just after the drum begins its downward movement. In any process involving the step of forming an open pouch, the substrate may initially be molded or formed into the shape of an open pouch using thermoforming, vacuum forming, or both. Thermoforming involves heating the mold and / or substrate by applying heat in any known manner, such as by bringing the mold into contact with a heating element, or by blowing hot air or using a heating lamp. In the case of vacuum forming, vacuum assistance is used to help drive the substrate into the mold. In other embodiments, these two techniques may be combined to form the pouch; for example, the substrate may be formed into an open pouch by vacuum forming, and heat may be provided to facilitate the process. The open pouch is then filled with the composition to be contained therein. The filled open pouch is then closed, which may be done by any method. In some cases, such as in horizontal pouch forming processes, closure is achieved by continuously feeding a second material or substrate (such as a water-soluble substrate) over and onto the web of the open pouch, and then sealing the first and second substrates together. The second material or substrate may include the water-soluble polymer layer 10 described herein. It may be desirable to oriented the surface of the second substrate on which a barrier layer is applied such that it forms the outer surface of the pouch.

[0074] In this process, the first and second substrates are typically sealed in the area between the molds, and thus between the pouches formed in adjacent molds. The sealing can be accomplished by any method. Sealing methods include heat sealing, solvent welding, and solvent sealing or wet sealing. The sealed web of the pouches can then be cut using a cutting device that cuts the pouches in the web into individual pouches. The process for forming water-soluble pouches is further described in U.S. Patent Application Serial No. 09 / 994,533, Publication No. US 2002 / 0169092 A1, published by Catlin et al.

[0075] The sealing mechanism can be a thermal seal, a water seal, a moisture seal, an ultrasonic seal, an infrared seal, or any other type of seal deemed suitable.

[0076] Products

[0077] like Figure 6 As shown, the present invention also includes an article comprising a product composition 400 and a water-soluble film 100 having an integrated water-dispersible barrier, the water-soluble film being formable as a container 300, such as a sachet, pouch, capsule, bag, etc., to contain the product composition. The surface of the water-soluble polymer layer opposite to the surface on which the water-dispersible barrier layer is applied may be used to form the outer surface of the container 300. The water-soluble film 100 having the integrated water-dispersible barrier may form at least a portion of the container 300 providing a unit dose of the product composition 400. For simplicity, the article of interest herein will be described in the form of a water-soluble sachet; however, it should be understood that the discussion herein also applies to other types of containers.

[0078] The pouch 300 formed by the aforementioned method can have any form and shape, adapted to contain the composition 400 contained therein, until it is desired to release the composition 400 from the water-soluble pouch 300, such as by immersing the water-soluble pouch 300 in water. The pouch 300 may include one compartment, or two or more compartments (i.e., the pouch may be a multi-compartment pouch). In one embodiment, the water-soluble pouch 300 may have two or more compartments in a generally stacked relationship, and the pouch 300 includes generally opposing upper and lower outer walls, skirt-like sidewalls forming the sides of the pouch 300, and one or more inner partition walls separating the different compartments from each other. If the composition 400 contained in the pouch 300 comprises different forms or components, the different components of the composition 400 may be contained in different compartments of the water-soluble pouch 300 and may be separated from each other by barriers of water-soluble material.

[0079] The sachet or other container 300 may contain one or more compositions 400 in unit doses for use as / for use in laundry detergent compositions, automatic dishwashing detergent compositions, hard surface cleaners, stain removers, fabric strengtheners and / or fabric softeners, hair care compositions, beauty care compositions, oral care compositions, health care compositions, personal hygiene compositions, and household cleaning compositions; such as shampoos, conditioners, mousses, facial soaps, hand soaps, shower soaps, liquid soaps, bar soaps, moisturizers, skin lotions, shaving lotions, toothpaste, mouthwash, hairspray, hand soaps, laundry detergent compositions, dishwashing detergents, automatic dishwasher detergent compositions, cosmetics, and over-the-counter drugs, razors. This invention pertains to absorbent products, wipes, hairsprays, food and beverages, animal food products, menstrual cups, exfoliating pads, electrical and electronic consumer devices, brushes, applicators, earplugs, eye masks, eye patches, face masks, agricultural products, plant foods, plant seeds, pesticides, ant killers, alcoholic beverages, animal food products, electronic products, pharmaceuticals, confectionery, pet food, pet health products, cannabis-derived products, industrial hemp-derived products, CBD-based products, other products derived from drugs other than cannabis, vitamins, non-pharmaceutical natural / herbal "health" products, and food and beverage products and new product forms that may experience premature pouch dissolution, undesirable pouch leakage, and / or undesirable interpouch stickiness upon contact with small amounts of water. Typical absorbent products of this invention include, but are not limited to, diapers, adult incontinence briefs, training pants, diaper fasteners, menstrual pads, incontinence pads, linings, absorbent inserts, sanitary pads, tampons, menstrual underwear, sponges, tissues, paper towels, wipes, flannel, etc. Pouch stickiness from migrating chemicals within the formulated product will also be reduced. The composition 400 in the sachet 300 can be in any suitable form, including but not limited to: liquids, gels, pastes, creams, solids, granules, powders, capsules, pills, sugar-coated pills, solid foams, fibers, etc. The different compartments of the multi-compartment sachet 300 can be used to separate incompatible components. For example, it may be desirable to separate bleaching agents and enzymes into separate compartments. Due to the potential improvement in barrier properties, dyes and fragrances commonly used in some fabric and home care products should exhibit greater stability within these new sachets. Other forms of the multi-compartment embodiment may include liquid-containing compartments combined with powder-containing compartments. Further examples of multi-compartment water-soluble sachets are disclosed in U.S. Patent 6,670,314B2 to Smith et al.

[0080] The water-soluble sachet 300 can be dropped into any suitable aqueous solution (such as hot or cold water), and the water-soluble membrane 100 with an integrated water-dispersible barrier that forms the water-soluble sachet 300 dissolves to release the contents of the sachet. The water-soluble membrane 100 with an integrated water-dispersible barrier described herein can also be used in coated products and other articles. Non-limiting examples of such products are laundry detergent tablets or automatic dishwashing detergent tablets. Other examples include coated products in the food and beverage categories, where contact with small amounts of water can result in premature dissolution, undesirable leakage, and / or undesirable stickiness.

[0081] Other product forms (articles) include disposable aprons, laundry bags, disposable hospital bedding, skin patches, face masks, disposable gloves, disposable hospital gowns, medical devices, skin wraps, agricultural mulch films, shopping bags, sandwich bags, garbage bags, first aid blankets and clothing, construction / construction wraps and moisture-proof linings, primary packaging for transport (such as envelopes and mailed advertising prints), and non-absorbent clothing articles that can be used to package clothing items (such as skirts, shirts, suits, and shoes).

[0082] Test methods

[0083] When testing and / or measuring materials, if the relevant test method does not specify a particular temperature, the test and / or measurement shall be performed on the specimens at 23°C (±3°C) (where such specimens are pre-conditioned to this temperature). When testing and / or measuring materials, if the relevant test method does not specify a particular humidity, the test and / or measurement shall be performed on the specimens at 35% (±5%) (where such specimens are pre-conditioned to this humidity). Testing and / or measurement shall be performed by trained, skilled, and experienced personnel in accordance with good laboratory practices using appropriately calibrated equipment and / or instruments.

[0084] 1) Membrane dissolution in water

[0085] When tested according to the slide dissolution test, this test method measures the total time for a specific film sample to completely dissolve. This slide dissolution test is test method 205 (MSTM 205) as described in paragraphs 116-131 of U.S. Patent Application Publication US20150093526A1 entitled "Water-soluble film having improved dissolution and stress properties, and packets made therefrom". The entire disclosure is incorporated herein by reference. The dissolution test method used herein is the same as that described in US20150093526A1, except that the temperature of the distilled water is 23°C, the beaker diameter is approximately 10 cm, and the test duration is limited to 24 hours. The results are individual and average disintegration times (time to membrane rupture) and individual and average dissolution times (time to no visible solid residue). Unless explicitly stated otherwise, the dissolution test method uses distilled water maintained at 23°C. The dissolution test method is not applicable to materials other than membranes with a total thickness equal to or less than 3 mm. If the average dissolution time measured according to the dissolution test method is less than 24 hours, the membrane according to the present invention is considered to be water-soluble.

[0086] 2) Water vapor transport rate

[0087] The test method was performed according to ASTM F1249-13 under the following test conditions: a temperature of 40°C (±0.56°C) and a relative humidity of 50% (±3%) or 90% (±3%). Water vapor transport rate was measured using a Permatran-W Model 3 / 33 instrument from Mocon (Minneapolis, USA) and expressed as [g / m³]. 2 [Daily] Report. For materials outside the scope of ASTM F-1249-13 (§1.1), the water vapor transport rate test method is not applicable.

[0088] 3) Overall membrane / individual layer thickness

[0089] The thickness of the film sample was measured by cutting a 20 μm thick cross-section using a sliding slicer (e.g., Leica SM2010 R), placing it under a light transmission mode optical microscope (e.g., Leica Diaplan), and applying imaging analysis software. The water-dispersible nanosheet layer contrasted strongly with the water-soluble polymer layer. In the case of adjacent water-soluble polymer layers, the contrast could be achieved by adding different tracers such as 0.5 wt% Rhodamine B or 0.5 wt% titanium dioxide nanoparticles.

[0090] 4) Scanning electron microscopy

[0091] SEM images were recorded using the Zeiss Ultra Plus instrument from Carl Zeiss AG (Oberkochen, Germany), which operates at 3.0 kV and is equipped with an in-lens secondary detector. Sample specimens were prepared by cutting a cross-section of the membrane with a surgical scalpel at room temperature.

[0092] Example

[0093] Preparation of water-soluble polyvinyl alcohol (PVOH) solution (30% solid)

[0094] Heat 1070g of softened water to 50°C in a Thermomix™ 5. Add 400g of solid PVOH powder (Selvol 205, obtained from Sekisui Chemical Co., Tokyo, Japan) with stirring at level 2.5-3.0 and set the temperature to 85°C. When the temperature of 85°C is reached (within about 5 minutes), reduce the stirring level to 1.0-1.5 to avoid excessive foaming. After stirring continuously at 85°C for 30 minutes, the polymer is dissolved. Meanwhile, mix 50g of sorbitol and 50g of glycerol with 100g of softened water at 85°C. Then, mix the polymer and plasticizer solution at 85°C with stirring at level 1.0-1.5 for about 5 minutes. Store the solution at room temperature overnight to eliminate any residual foam.

[0095] Preparation of water-soluble polyethylene oxide (PEO) solution (30% solids)

[0096] 1070 g of softened water was heated to 50 °C in a Thermomix™ 5. 400 g of solid PEO powder (WSR N-80, from Dow Chemicals Inc., Midland, Michigan) was carefully added gradually with stirring at a speed of 2.5-3.0, and the temperature was set to 85 °C. The polymer was dissolved after stirring continuously at 85 °C for 3 hours. Simultaneously, 50 g of glycerol and 50 g of sorbitol were mixed with 100 g of softened water at 85 °C. Finally, the polymer and plasticizer solution were mixed at 85 °C with stirring at a speed of 2.5-3.0 for approximately 5 to 10 minutes. The solution was then stored at room temperature overnight.

[0097] Preparation of water-soluble hydroxypropyl methylcellulose (HPMC) solution (20% solids)

[0098] Heat 1900g of softened water to 50°C in a Thermomix™ 5. Add 400g of solid hydroxypropyl methylcellulose powder (E15LV, from Parchem Chemicals) with stirring at level 2.5-3.0 and set the temperature to 85°C. When the temperature of 85°C is reached (within approximately 5 minutes), reduce the stirring level to 1.0-1.5 to avoid excessive foaming. After stirring continuously at 85°C for 30 minutes, the polymer is dissolved. Meanwhile, mix 50g of sorbitol and 50g of glycerol with 100g of softened water at 85°C. Then, mix the polymer and plasticizer solution at 85°C with stirring at level 1.0-1.5 for approximately 5 minutes. Store the solution overnight at 60°C to eliminate any residual foam, and compensate for the evaporated water with additional softened water.

[0099] Preparation of water-soluble alginate solution (15% solid)

[0100] 1370g of softened water was heated to 50°C in a Thermomix™ 5. 200g of solid sodium alginate powder (Vivastar CS002, obtained from JRS) was carefully added gradually with stirring at level 2.5-3.0, and the temperature was set to 85°C. After stirring continuously at 85°C for 3 hours, the polymer was dissolved. Meanwhile, 25g of glycerol and 25g of sorbitol were mixed with 50g of softened water at 85°C. Finally, the polymer and plasticizer solution were mixed at 85°C with stirring at level 2.5-3.0 for approximately 5 to 10 minutes. The solution was then stored at room temperature overnight.

[0101] Preparation of water-dispersible corothiate dispersion (7% solids)

[0102] Corotethite is a natural bentonite, purified by BYK and subjected to oxidation from Ca. 2+ To Na + The cation exchange process was performed to allow it to be completely exfoliated in water. The aspect ratio was then set to approximately 200. 1120 g of softened water was heated to 50 °C in a Thermomix TM 5. 100 g of masterbatch paste (CNaMGH, from MBN Nanomaterialia, consisting of 80% sodium corothiate (from BYK) exfoliated in 20% water) was added with stirring at level 3.0. Once complete, the stirring level was increased to 5.0, and any remaining paste agglomerates were scraped off from the mixing vessel walls / mixer blades. After continuous stirring at level 5.0 for 30 minutes, the nanosheets were homogeneously dispersed, forming a brown, viscous liquid / gel, leaving some residue on the vessel walls, which had to be removed by a scraper.

[0103] Preparation of water-dispersible lithium montmorillonite dispersion (6% solids)

[0104] The following is a synthesis of sodium lithium montmorillonite [Na]0.5 ] inter [Mg 2.5 Li 0.5 ] oct [Si4] tet O 10 F2: Carefully weigh the high-purity reagents SiO2 (Merck, fine particles, washed and calcined quartz), LiF (ChemPur, 99.9%, powder), MgF2 (ChemPur, 99.9%, 3mm to 6mm molten blocks), MgO (Alfa Aesar, 99.95%, 1mm to 3mm molten blocks), and NaF (Alfa Aesar, 99.995%, powder) according to the formulation. A molybdenum crucible (25mm outer diameter, 21mm inner diameter, 180mm length) was supplied by Plansee SE (Reutte, Austria). For cleaning purposes, these crucibles were first vacuum-heated to 1600°C in quartz tubes placed within copper-based high-frequency induction heating coils. The reagents were then added to the crucibles under an argon atmosphere (glove box) and heated to 1200°C under vacuum to remove any residual water. The crucibles were then sealed with molybdenum caps by heating both parts to the melting point of molybdenum. Therefore, a sealed crucible was placed horizontally in a graphite furnace under an argon atmosphere and rotated at 1750°C for 80 minutes. The crucible was then opened, and the obtained sodium lithium montmorillonite was collected, ground using a planetary ball mill, and dried in a clean crucible at 250°C under an argon atmosphere for 14 hours. The crucible was then sealed with a molybdenum cap and annealed in a graphite furnace at 1045°C for 6 weeks to increase the homogeneity of the sodium lithium montmorillonite. The material was then placed in a desiccator at (23°C, 43% relative humidity) to achieve hydration of [Na]. 0.5 ] inter [Mg 2.5 Li 0.5 ] oct [Si4] tet O 10 F2·[H2O]2. Then, double-distilled water was added to achieve a 6% lithium montmorillonite dispersion in water. Finally, the dispersion was placed at 23°C for 2 weeks to complete the exfoliation of lithium montmorillonite nanosheets. The aspect ratio was then approximately 20,000.

[0105] Laboratory-grade fabrication of water-soluble membranes with integrated water-dispersible barrier components

[0106] All aqueous solutions / dispersions were homogenized at 2500 rpm and degassed for 5 minutes (23°C, 50 mbar) using a SpeedMixer DAC400.2VAC-P from Hauschild & Co KG (Hamm, Germany). (Before use). Multilayer films were fabricated via slit coating using a lab-grade TSE Table Coater equipped with a 300 mm wide single-layer slit die (coating width 210 mm, pad thickness 165 μm) and a unidirectional moving vacuum stage. The vacuum stage supported and held the carrier film required for the first wet coating. Once coated, the aqueous solutions / dispersions were dried by heating the vacuum stage to 50°C. The drying process was accelerated by gentle and uniform vapor suction using a microporous plate positioned parallel to and on the wet coated surface.

[0107] 1) Water-soluble PVOH membrane with integrated water-dispersible lithium montmorillonite barrier

[0108] In one embodiment, a first water-soluble polymer layer is formed by coating an aqueous PVOH solution (30% solids) onto an untreated PLA carrier membrane (BOPLA-Folie NTSS 25NT, obtained from Pütz GmbH+Co Folien KG (Taunusstein, Germany)) at 23°C. For this purpose, the gap between the slit head and the application surface is set to 205 μm, the pump flow rate is set to 2.52 ml / min, and the stage speed is set to 0.1 m / min. The wet coating is dried at 60°C for 15 minutes, and the resulting dried layer consists of 80% PVOH, 10% glycerol, and 10% sorbitol. Then, a water-dispersible nanosheet layer is added by coating an aqueous lithium montmorillonite sodium dispersion (6% solids) at 23°C. For this purpose, the gap between the slit head and the application surface is set to 385 μm, the pump flow rate is set to 4.6 ml / min, and the stage speed is set to 0.1 m / min. The wet coating was dried at 23°C for 7 days, and the resulting dried layer consisted of 100% sodium lithium montmorillonite. A second water-soluble polymer layer was added by coating with an aqueous PVOH solution (30% solids) at 23°C. For this purpose, the gap between the slit die and the application surface was set to 250 μm, the pump flow rate was set to 2.52 ml / min, and the stage speed was set to 0.1 m / min. The wet coating was dried at 60°C for 30 minutes, and the resulting dried layer consisted of 80% PVOH, 10% glycerol, and 10% sorbitol.

[0109] 2) Water-soluble hydroxypropyl methylcellulose membrane with integrated water-dispersible lithium montmorillonite barrier

[0110] In one embodiment, a first water-soluble polymer layer is formed by coating an aqueous hydroxypropyl methylcellulose solution (20% solids) onto an untreated PLA carrier membrane (BOPLA-Folie NTSS 25NT, obtained from Pütz Folien (Germany)) at 23°C. For this purpose, the gap between the slit head and the application surface is set to 450 μm, the pump flow rate is set to 5.9 ml / min, and the stage speed is set to 0.1 m / min. The wet coating is dried at 50°C for 1 hour, and the resulting dried layer consists of 80% hydroxypropyl methylcellulose, 10% glycerol, and 10% sorbitol. Then, a water-dispersible nanosheet layer is added by coating an aqueous lithium montmorillonite sodium dispersion (6% solids) at 23°C. For this purpose, the gap between the slit head and the application surface is set to 385 μm, the pump flow rate is set to 4.6 ml / min, and the stage speed is set to 0.1 m / min. The wet coating was dried at 23°C for 7 days, and the resulting dried layer consisted of 100% sodium lithium montmorillonite. A second water-soluble polymer layer was added by coating with an aqueous hydroxypropyl methylcellulose solution (20% solids) at 23°C. For this purpose, the gap between the slit die and the application surface was set to 480 μm, the pump flow rate was set to 5.9 ml / min, and the stage speed was set to 0.1 m / min. The wet coating was dried at 50°C for 2 hours, and the resulting dried layer consisted of 80% hydroxypropyl methylcellulose, 10% glycerol, and 10% sorbitol.

[0111] 3) Water-soluble alginate membrane with integrated water-dispersible lithium montmorillonite barrier

[0112] In one embodiment, a first water-soluble polymer layer is formed by coating an aqueous alginate solution (15% solids) onto an untreated PLA carrier membrane (BOPLA-Folie NTSS 25NT, obtained from Pütz Folien (Germany)) at 23°C. For this purpose, the gap between the slit head and the application surface is set to 475 μm, the pump flow rate is set to 1.92 ml / min, and the stage speed is set to 0.03 m / min. The wet coating is dried at 23°C for 1 hour, and the resulting dried layer consists of 80% alginate, 10% glycerol, and 10% sorbitol. Then, a water-dispersible nanosheet layer is added by coating an aqueous lithium montmorillonite sodium dispersion (6% solids) at 23°C. For this purpose, the gap between the slit head and the application surface is set to 385 μm, the pump flow rate is set to 4.6 ml / min, and the stage speed is set to 0.1 m / min. The wet coating was dried at 23°C for 7 days, and the resulting dried layer consisted of 100% sodium lithium montmorillonite. A second water-soluble polymer layer was added by coating with an aqueous alginate solution (15% solids) at 23°C. For this purpose, the gap between the slit die and the application surface was set to 500 μm, the pump flow rate was set to 1.92 ml / min, and the stage speed was set to 0.03 m / min. The wet coating was dried at 23°C for 2 hours, and the resulting dried layer consisted of 80% alginate, 10% glycerol, and 10% sorbitol.

[0113] Table 1

[0114]

[0115] Pilot-scale fabrication of water-soluble membranes with integrated water-dispersible barrier components

[0116] 4) Water-soluble PVOH membrane with integrated water-dispersible chlorothiazide barrier

[0117] In one embodiment, the first single water-soluble polymer layer is formed by: applying 100 μL of an aqueous PVOH solution to an untreated PET carrier film (Hostaphan RN 50-350, obtained from Mitsubishi) via a slit die from FMP Technology at 85°C, and removing water via a convection dryer from FMP Technology set to 95°C. The resulting 30 μL dried layer consists of 80% Selvol 205 (obtained from Sekisui Chemicals), 10% glycerol, and 10% sorbitol. Then, a water-dispersible nanosheet layer is added by: applying 100 μL of an aqueous crositol dispersion to the first single water-soluble polymer layer via a slit die from FMP Technology at 50°C, and removing water via a convection dryer from FMP Technology set to 95°C. The resulting 7 μm dried layer was composed of 100% sodium corothiot (from BYK). A second single water-soluble polymer layer was formed by slit-coating a 100 μm aqueous PVOH solution onto the water-dispersible nanosheet layer at 85 °C using a slit-drill from FMP Technology, followed by water removal via a convection dryer from FMP Technology set to 95 °C. The resulting 30 μm dried layer was composed of 80% Selvol 205 (from Sekisui Chemicals), 10% glycerol, and 10% sorbitol.

[0118] In this embodiment, water is removed from the aqueous nanosheet dispersion by setting different temperatures in a convection dryer. As shown in Table 2, drying temperatures in the range of 50°C to 95°C did not produce a significant difference in the barrier properties of the aqueous nanosheet layers. The WVTR measured according to method ASTM F1249-13 at [40°C, 50%] was 8.1 ± 0.6 g / m³. 2 / day]. Using a barrier thickness of 7.2±0.2μm, the water vapor permeation (WVP) was approximately 1600±100 [g.μm / m]. 2 / day / bar]. This value is specific to the properties of the sodium corothiot material and the slot die coating process.

[0119] Table 2

[0120]

[0121] In another embodiment, the first single water-soluble polymer layer is formed by coating a 50 μm aqueous PVOH solution onto an untreated PET carrier film (Hostaphan RN 50-350, from Mitsubishi Polyester Film GmbH, Wiesbaden, Germany) via an anilox roller at 80°C, and removing water via a convection dryer from Drytec set to 95°C. The resulting 13 μm dried layer consists of 80% Selvol 205 (from Sekisui Chemicals), 10% glycerol, and 10% sorbitol. A second and third water-soluble polymer layer are added to the first single water-soluble polymer layer via the same process. Then, a water-dispersible nanosheet layer is added by coating a 100 μm aqueous chlorothiazide dispersion onto the water-soluble polymer layer via a reverse roller at 50°C, and removing water via a convection dryer from Drytec set to 95°C. The resulting 7μm dried layer was composed of 100% sodium corothiate (obtained from BYK). Three additional water-soluble polymer layers were added to the water-dispersible nanosheet layer via an anilox roller coating.

[0122] exist Figure 4 The image shows a water-dispersible chlorothiazide layer located between the upper and lower water-soluble PVOH layers. The image was obtained by scanning electron microscopy of a thin 20 μm cross-section of the water-soluble multilayer film and magnified approximately 20,000 times.

[0123] In such implementations, the aqueous crorotate dispersion is further diluted from 7% to 3% solids to reduce dispersion viscosity and improve coating processes (e.g., line speed, coating quality). However, as shown in Table 3, the lower [% solids] in the aqueous crorotate dispersion also results in surprisingly lower barrier properties, possibly because the lower [% solids] leads to higher water-soluble polymer embedding in the water-dispersible nanosheets.

[0124] Table 3

[0125]

[0126] The comparative examples were compared using the methods described above, but without the integrated water-dispersible nanosheets. As shown in Table 4, the barrier performance of the comparative examples was significantly lower: compared to 7.1 ± 1.0 [g / m] obtained with the integrated water-dispersible croseth barrier. 2 Compared to [ / day], the WVTR measured according to method ASTM F1249-13 at [40℃, 50%] is equal to 47.2 ± 1.1 [g / m³]. 2 / sky].

[0127] Table 4

[0128]

[0129] 5) Water-soluble PEO membrane with integrated water-dispersible croseth barrier

[0130] In one embodiment, the first single water-soluble polymer layer is formed by extruding 100 μL of an aqueous PEO solution onto an untreated PET carrier film (Hostaphan RN 50-350, obtained from Mitsubishi) via a slit die from FMP Technology at 85°C, and removing water via a convection dryer from FMP Technology set to 95°C. The resulting 34 μL dried layer consists of 80% WSR N-80 (obtained from Dow Chemicals), 10% glycerol, and 10% sorbitol. Then, a water-dispersible nanosheet layer is added by extruding 100 μL of an aqueous corothiate dispersion onto the first single water-soluble polymer layer via a slit die from FMP Technology at 50°C, and removing water via a convection dryer from FMP Technology set to 95°C. The resulting 5 μL dried layer consists of 100% sodium corothiate (obtained from BYK). The second single water-soluble polymer layer was formed by extruding 100 μL of an aqueous PEO solution onto a water-dispersible nanosheet layer via a slit die from FMP Technology at 85°C, and removing water via a convection dryer from FMP Technology set at 95°C. The resulting 34 μL dried layer consisted of 80% WSR N-80 (from Dow Chemicals), 10% glycerol, and 10% sorbitol.

[0131] Table 5

[0132]

[0133] As shown in Table 5, when measured at high relative humidity levels (90%), the water-soluble PEO film exhibits a high barrier improvement factor (approximately 50 times) when equipped with an integrated water-dispersible crositite barrier, making this option particularly attractive for flexible packaging applications.

[0134] Comparative example

[0135] The following comparative examples consist of water-soluble membranes having an integrated barrier layer made of a non-dispersible barrier material in water, and are therefore unsuitable for this application.

[0136] Preparation of PVDC solution (20% solids)

[0137] In a protective fume hood, heat 1000 g of a 60:40 mixture of methyl ethyl ketone (MEK) and ethyl acetate (EA) in a glass beaker to 50 °C. Add 200 g of polyvinylidene chloride (powder grade Resin F310, obtained from Asahi Kasei) with magnetic stirring. Once complete, increase the stirring level to maximum and turn off the heating. Continue stirring at maximum level for approximately 2 hours until the PVDC powder is completely dissolved. Store the solution at room temperature (RT) overnight to eliminate any residual foam.

[0138] Water-soluble PVOH membrane with integrated water-insoluble PVDC barrier

[0139] In one embodiment, a first single water-soluble polymer layer is formed by applying a 50 μL aqueous PVOH solution to an untreated PET carrier film (Hostaphan RN 50-350, obtained from Mitsubishi) via an anilox roller at 80°C, and removing water via a convection dryer from Drytec set to 95°C. The resulting 13 μL dried layer consists of 80% Selvol 205 (obtained from Sekisui Chemicals), 10% glycerol, 10% sorbitol, and 1% Hecostat (obtained from Hecoplast). A second and third water-soluble polymer layers are added to the first single water-soluble polymer layer via the same process. A non-dispersible PVDC barrier is then added by applying a 30 μL MEK / EA solution of PVDC to the water-soluble polymer layer via an anilox roller at 50°C, and removing the MEK / EA solvent via a convection dryer from Drytec set to 95°C. The resulting 3μm dried layer was composed of 100% PVDC grade F310 (obtained from Asahi Kasei). An additional water-soluble polymer layer was added by coating a 50μm aqueous PVOH solution onto a non-dispersible PVDC layer in water using an anilox roller at 80°C, followed by water removal via a convection dryer from Drytec set to 95°C. The resulting 15μm dried layer was composed of 80% Selvol 205 (obtained from Sekisui Chemicals), 10% glycerol, and 10% sorbitol.

[0140] Table 6

[0141]

[0142] As shown in Table 6 above, although the intermediate PVDC layer significantly reduces WVTR, water-insoluble PVDC does not meet the requirements of the invention according to this disclosure.

[0143] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​cited. Rather, unless otherwise specified, each such dimension is intended to represent the stated value and a range around which it is functionally equivalent. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

[0144] Unless expressly excluded or otherwise limited, every reference cited herein, including any cross-references or related patents or patent applications, and any patent application or patent claiming priority to or benefiting from it, is incorporated herein by reference in its entirety. Reference to any reference is not an endorsement of it as prior art to any disclosed or protected art herein, nor is it an endorsement of any such invention, either on its own or in combination with any one or more references. Furthermore, where any meaning or definition of a term in this invention conflicts with any meaning or definition of the same term in referenced documents, the meaning or definition given to that term in this invention shall prevail.

[0145] While specific embodiments of the invention have been illustrated and described by way of example, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered by the appended claims.

Claims

1. An article comprising a product composition and a water-soluble film, The water-soluble film is formed as a container to contain the product composition. The water-soluble membrane comprises: a) A first water-soluble polymer layer having a surface b) A second water-soluble polymer layer having a surface c) A water-dispersible barrier layer disposed between the first layer and the second layer, the water-dispersible barrier layer comprising more than 90% by weight of hydrophilic nanosheets. The water dispersibility mentioned above refers to the ability of nanosheets to break down into fragments smaller than one millimeter in water, and nanosheets that require more than 24 hours to disperse in water at 23°C are not considered to be dispersible in water. Polymers that require more than 24 hours to dissolve in water at 23°C are not considered water-soluble. The hydrophilic nanosheets have an average aspect ratio greater than 100, and The adhesion between the layers is provided solely by the molecular interactions between the water-soluble polymer and the hydrophilic nanosheets. The surface opposite to the surface of the water-soluble polymer layer and the surface on which the water-dispersible barrier layer is applied is used to form the outer surface of the container.

2. The article of claim 1, wherein the WVTR of the water-soluble film is 0.1 g / m³ when measured according to ASTM test method F1249-13 at 40°C and 50% relative humidity. 2 / 100g / m 2 / sky.

3. The article of claim 1, wherein the WVTR of the water-soluble film is 0.1 g / m³ when measured according to ASTM test method F1249-13 at 38°C and 90% relative humidity. 2 / 200g / m 2 / sky.

4. The article of claim 1, wherein the average thickness of the water-soluble polymer layer is from 1 µm to 1000 µm.

5. The article of claim 4, wherein the average thickness of the water-soluble polymer layer is from 10 µm to 250 µm.

6. The article of claim 4, wherein the average thickness of the water-soluble polymer layer is 25µm to 125µm.

7. The article of claim 1, wherein the water-soluble polymer layer comprises at least one water-soluble polymer.

8. The article of claim 7, wherein the water-soluble polymer is selected from polyvinyl alcohol, polyethylene oxide, methylcellulose and sodium alginate.

9. The article of claim 8, wherein the water-soluble polyvinyl alcohol is a partially or completely hydrolyzed homopolymer or copolymer.

10. The article of claim 8, wherein the water-soluble polyvinyl alcohol has an average molecular weight of 20,000 Da to 150,000 Da.

11. The article of claim 8, wherein the water-soluble polyvinyl alcohol is a homopolymer with a degree of hydrolysis of 70% to 100%.

12. The article of claim 11, wherein the water-soluble polyvinyl alcohol is a homopolymer with a degree of hydrolysis of 84% to 92%.

13. The article of claim 11, wherein the water-soluble polyvinyl alcohol is a homopolymer with a degree of hydrolysis of 86% to 90%.

14. The article of claim 1, wherein the water-soluble polymer layer comprises at least one water-soluble plasticizer.

15. The article of claim 14, wherein the plasticizer is at least one of water, glycerin, sorbitol, propylene glycol, trimethylene glycol, trimethylolpropane, methylpropane glycol, 2-methyl-1,3-propanediol, and mixtures thereof.

16. The article of claim 1, wherein the average thickness of the water-dispersible barrier layer is from 0.1 µm to 20 µm.

17. The article of claim 16, wherein the average thickness of the water-dispersible barrier layer is from 0.1 µm to 10 µm.

18. The article of claim 16, wherein the average thickness of the water-dispersible barrier layer is from 0.1 µm to 5 µm.

19. The article of claim 1, wherein the water-dispersible barrier layer comprises more than 96% by weight of hydrophilic nanosheets.

20. The article of claim 19, wherein the water-dispersible barrier layer comprises more than 99% by weight of hydrophilic nanosheets.

21. The article of claim 1, wherein the hydrophilic nanosheet is a clay nanosheet or a graphene oxide nanosheet.

Images