Polymer film

Abstract

The present invention relates to a coated water-soluble film comprising a base film of a water-soluble polymer and a water-soluble coating comprising at least one amphiphilic polymer; wherein the base film comprises polyvinyl alcohol. The invention also relates to a water soluble unit dose article comprising a composition packaged in a container comprising such a coated water soluble film; use of such water soluble unit dose articles as hard surface cleaners, disincrustant, toilet cleaners, dishwasher cleaners, home care compositions or multipurpose cleaners. In addition, the present invention relates to a method of making such a coated water-soluble film comprising providing a water-soluble polymer-based film; and a method step of coating the base film with at least one amphiphilic polymer.

Description

Technical Field

[0001] The present invention relates to a coated water-soluble film, a water-soluble unit dose product, a method for preparing the same, and the use of the water-soluble unit dose product. Background Art

[0002] Water-soluble polymer films are commonly used as packaging materials to simplify the dispersion, pouring, dissolving and dosing of materials to be delivered. Consumers can, for example, directly add the composition packaged in the water-soluble polymer film to a mixing container, such as a bucket, a tank or a washing machine. Advantageously, this provides accurate dosage, while eliminating the need for the consumer to measure the composition. In addition, the water-soluble polymer film packaging can separate strong chemicals from the hands of the consumer, protecting the consumer from contact with reactive chemicals. The packaged composition can also reduce the confusion associated with distributing similar compositions from a container, for example, pouring the composition from a bottle. In a word, the solubility pre-measured polymer film packaging provides convenience and safety for the consumer in various applications.

[0003] Some water-soluble polymer films used to make currently commercially available packaging pouches interact with pouch components (e.g., oxidants, acids, bases, etc.), which affects the properties of the pouch, such as the solubility of the film, especially after storage. For example, the pouch may exhibit a decrease in film solubility over time when in contact with the contents therein. This decreased solubility may, for example, result in a significant amount of residue remaining after the contents of the pouch have been dispersed. In other cases, the film may change color or lose elasticity and become brittle, causing the pouch or packet to rupture prematurely and release the contents before use.

[0004] Polyvinyl alcohol (PVOH) is one such water-soluble polymer commonly used to form unit dose packaging because PVOH films exhibit good strength, impact resistance and are soluble in water. However, when exposed to certain reactive chemicals such as acids, oxidants, bases, bleaches, etc., the solubility of PVOH films decreases rapidly.

[0005] Therefore, the use of PVOH packaging is limited in applications using these types of chemicals because the effective shelf life of the unit dose product is limited by their solubility in water.

[0006] This is a particular problem in the case of packaging reactive acids, especially those containing more than one carboxylic acid group, such as citric acid. Citric acid is an attractive active agent in many cleaning products such as machine descaling agents and acidic hard surface cleaners. However, such acids react with polyol films such as PVOH, especially at high temperatures and humidity, crosslinking them and rendering them water insoluble.

[0007] Attempts have been made to mitigate the above mentioned problems. US patent application US2014 / 0110301A1 describes the use of polymer films comprising PVOH copolymers containing vinyl alcohol, vinyl ester and pyrrolidone monomers for improving the water solubility, biodegradability and physical properties of PVOH films when in contact with harsh oxidizing chemicals.

[0008] International patent application WO 2021 / 067482 A1 describes the use of a polymer film comprising a water-soluble mixture of PVOH and polyvinylpyrrolidone (PVP) to form a soluble packaging for holding harsh chemical compositions.

[0009] Although these methods have seen some success in improving the compatibility of PVOH films with reactive chemicals, they also have several disadvantages. First, in such methods, the high loading of the entire PVOH film requires the use of high loadings of additional polymers (such as PVP) to improve reactive chemical compatibility.

[0010] Furthermore, studies have shown that the PVP / PVOH system (used in the above method) can still be cross-linked by reactive chemicals such as citric acid (S. Thongsuksaengcharoen et al., ACS Omega 2020, 5, 25973-25983).

[0011] In view of the foregoing, there remains a need for water-soluble polymer films, particularly PVOH films, that improve upon these and / or other shortcomings of the prior art.

[0012] It is an object of embodiments of the present invention to solve one or more of the above problems by providing a water-soluble polymer film that provides one or more of the following advantages:

[0013] • The ability to contain reactive chemicals (e.g. acids, oxidants, bases, bleaches, aldehydes, etc., especially acids containing more than one carboxylic acid group, such as citric acid) in packaging while also maintaining good water solubility, elasticity and / or resistance to discoloration.

[0014] • Essentially inert towards reactive chemicals, especially crosslinking with acids containing more than one carboxylic acid group.

[0015] • The physical and chemical properties and / or aesthetics of the film are not adversely affected after long storage times at high temperature / high humidity with or without reactive chemicals.

[0016] • The ability to dissolve readily in water, preferably even in cold water.

[0017] • Ability to maintain the optical clarity of unmodified water-soluble polymer films.

[0018] Good sealing properties with other polymer membranes.

[0019] • Direct production. Preferably produced using standard methods and equipment.

[0020] · Ability to be used to package chemicals without adversely affecting their properties.

[0021] Improved operations.

[0022] It is also an object of embodiments of the present invention to overcome or mitigate at least one problem of the prior art, whether explicitly disclosed herein or not. Summary of the invention

[0023] According to a first aspect of the present invention, there is provided a coated water-soluble film comprising a water-soluble polymer base film and a coating layer comprising at least one amphiphilic polymer.

[0024] This polymer film comprising at least one amphiphilic polymer coating exhibits inertness when in contact with reactive chemicals, particularly solid acids such as citric acid containing more than one carboxylic acid group. Even when exposed to reactive chemicals for a long time under high temperature / high humidity, the coated film also exhibits this inertness. Without wishing to be bound by theory, it is believed that the amphiphilic polymer coating forms a physical barrier between the water-soluble base film and the reactive chemicals in contact, which avoids undesirable reactions between the film and the reactive chemicals, such as cross-linking reactions. In addition, the physical and chemical properties and aesthetics of the film are not adversely affected-the film maintains good water solubility (even in cold water), elasticity and flexibility, and minimal discoloration. This coated film also advantageously maintains the optical transparency of the unmodified water-soluble polymer film.

[0025] In some embodiments, the water-soluble polymer base film comprises at least one polymer with a nucleophilic group, which may be a part of a side chain. The nucleophilic group may comprise a functional group, such as an alcohol group, a phenol group, an amine group, a thiol group, and derivatives thereof, anions or combinations. In a preferred embodiment, the water-soluble polymer base film comprises a polyol, most preferably polyvinyl alcohol (PVOH) or derivatives thereof or copolymers.

[0026] The PVOH of the base film can be partially or completely alcoholized or hydrolyzed. The PVOH of the base film can be a polyvinyl acetate film that is at least 10% alcoholized or hydrolyzed, or a polyvinyl acetate film that is at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or at least 95% alcoholized or hydrolyzed. The PVOH of the base film can be a base film that is substantially completely alcoholized or hydrolyzed. The PVOH of the base film can be a polyvinyl acetate film that is not more than 98% alcoholized or hydrolyzed, or a base film that is not more than 96%, 94%, 92%, 90%, 88%, 86%, 84%, 82% or not more than 80% alcoholized or hydrolyzed. The PVOH of the base film can be an alcoholized or hydrolyzed polyvinyl acetate film, wherein the film is alcoholized or hydrolyzed in the range of 40% to 100%, preferably 65% ​​to 99.99%, more preferably 72% to 92%, and most preferably 80% to 90%. It is known that the degree of hydrolysis affects the temperature at which the PVOH base film begins to dissolve in water. For example, 88% hydrolysis corresponds to a base film that is soluble in cold (i.e., room temperature) water, while 92% hydrolysis corresponds to a film that is soluble in warm water.

[0027] The PVOH-based film may be a thermoformed PVOH film.

[0028] In some embodiments, the base film comprises PVOH or its derivatives in an amount of at least 50% by weight of the base film, or at least 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or at least 95% by weight of the base film. In some preferred embodiments, the base film is made entirely of PVOH or its derivatives. In a preferred embodiment, the base film comprises PVOH or its derivatives in an amount of 70% to 85% by weight of the base film.

[0029] The base film can be cast, blown or extruded. It can also be non-oriented, uniaxially oriented or biaxially oriented.

[0030] In some embodiments, the base film has a thickness of at least 10 μm, or at least 20, 30, 40, 50, 60, or at least 70 μm, or preferably at least 80 μm, or at least 90 μm. The base film may have a thickness of not more than 200 μm, or not more than 175, 150, 125, or not more than 100 μm. In some embodiments, the base film may have a thickness of 20 to 160 μm, or 30 to 150 μm, or 40 to 140 μm, or 50 to 130 μm, or 55 to 120 μm, or 60 to 110 μm, or preferably 65 to 100 μm, or 70 to 95 μm.

[0031] In some embodiments, the base film is at least 50% transparent, or at least 60%, 70%, 80%, or at least 90% transparent. In some embodiments, the base film is substantially completely transparent.

[0032] In some embodiments, the coating is present on the surface of the base film. The coating may preferably be present as a layer on the surface of the base film. In some embodiments, the coating is substantially separated from the surface of the base film. The coating may be bonded to the surface of the base film. The coating may be bonded to the surface of the base film by covalent bonds, ionic bonds, hydrogen bonds or van der Waals forces. At least one amphiphilic polymer of the coating may be bonded to the surface of the base film via one or more surface linking groups, which may be present on the amphiphilic polymer and / or the base film surface.

[0033] In some embodiments, the coating may be welded or physically entangled with the base film.

[0034] In some embodiments, the coating is present on at least 10% of the surface area of ​​the substrate, or at least 20%, 30%, 40%, 50%, 60%, 70%, or at least 80% of the surface area of ​​the substrate. In some preferred embodiments, the coating is present on at least 85% of the surface area of ​​the substrate, or at least 90% of the surface area of ​​the substrate, or at least 95% of the surface area of ​​the substrate, or substantially 100% of the surface area of ​​the substrate. The coating may be present on no more than 98% of the surface area of ​​the substrate, or no more than 96%, 94%, 92%, 90%, 88%, 86%, 84%, 82%, or no more than 80% of the surface area of ​​the substrate. The coating may be present between 10 and 100% of the surface area of ​​the substrate, or between 40 and 100% of the surface area of ​​the substrate, or between 60 and 100% of the surface area of ​​the substrate, or between 80 and 100% of the surface area of ​​the substrate.

[0035] In some embodiments, the base film may be in the form of a sheet having two faces. In such embodiments, the coating may be present on both faces of the base film sheet. In a preferred embodiment, the coating may be present only on one face of the base film sheet, preferably on the face that may contact reactive chemicals during use. In such embodiments, the above statements about the % of the base film surface area on which the coating is present may be used to refer to the surface area of ​​one face of the base film or both faces of the base film. In such embodiments, other statements about the base film surface in this specification may relate only to the surface of one face of the base film sheet or may relate to the surface of both faces of the base film sheet.

[0036] In some embodiments, the coating is evenly distributed on the surface of the base film. In other embodiments, the coating is unevenly distributed on the surface of the base film. For example, the coating may be more concentrated on portions of the base film surface that may be in closer contact with the reactive chemical or may be in contact with the reactive chemical for a longer period of time during use than other portions of the surface.

[0037] In some embodiments, the coating may be at least 0.05 mg / cm 2 , or at least 0.1 mg / cm 2, 0.2mg / cm 2 , 0.3mg / cm 2 , 0.4mg / cm 2 , 0.5mg / cm 2 , 0.6mg / cm 2 , 0.7mg / cm 2 , 0.8mg / cm 2 , 0.9mg / cm 2 or at least 1 mg / cm 2 The coating may be no greater than 10 mg / cm 2 , or not more than 9mg / cm 2 , 8mg / cm 2 , 7mg / cm 2 , 6mg / cm 2 , 5mg / cm 2 , 4mg / cm 2 or not more than 2mg / cm 2 The coating may be present on the surface of the base film or a portion thereof at a loading of 0.05 to 10 mg / cm 2 , or 0.1 to 8 mg / cm 2 , or preferably 0.2 to 6 mg / cm 2 , or more preferably 0.3 to 4 mg / cm 2 , or 0.4 to 3 mg / cm 2 , or preferably 0.5 to 2 mg / cm 2 , or 0.7 to 1.7 mg / cm 2 , or most preferably 0.8 to 1.4 mg / cm 2 The loading is present on the surface of the base film or a portion thereof. In such an embodiment, the coating is preferably evenly distributed on the surface of the base film or said portion thereof.

[0038] In some embodiments, the coating is present in an amount of at least 0.5% by weight of the coated film. In some embodiments, the coating is present in an amount of no more than 10% by weight of the coated film, or no more than 8%, 6%, 4%, 2% by weight of the coated film, or no more than 1% by weight. The coating may be present in an amount of 0.05 to 40% by weight of the coated film, or 1 to 35% by weight, or 1 to 30% by weight, or 1 to 25% by weight, or 2 to 20% by weight, or 3 to 17% by weight, or 4 to 15% by weight, or 5 to 12% by weight, or 6 to 10% by weight.

[0039] In some embodiments, the coating comprises a layer having a thickness of at least 0.2 μm, or at least 0.4, 0.6, 0.8, or at least 1 μm, or at least 2, 3, 4, 5, 6, 7, 8, 9, or at least 10 μm. In some embodiments, the coating comprises a layer having a thickness of no more than 60 μm, or no more than 55, 50, 45, or preferably no more than 40, 35, 30, 25, or no more than 20 μm. The coating may comprise a layer having a thickness of 0.2 to 60 μm, or 0.5 to 50 μm, or 1 to 40 μm, or 1 to 30 μm, or 1 to 20 μm, or 5 to 20 μm, or 5 to 15 μm.

[0040] In some embodiments, the coating has an amphiphilic polymer concentration of at least 10% by weight of the coating, or at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or at least 95% by weight of the coating. The coating can have an amphiphilic polymer concentration of substantially 100% by weight of the coating. The coating can have an amphiphilic polymer concentration of no more than 98% by weight of the coating, or no more than 96%, 94%, 92%, 90%, 88%, 86%, 84%, 82%, or no more than 80% by weight of the coating.

[0041] In a preferred embodiment, the amphiphilic polymer of the coating and / or substantially the entire coating is soluble in a non-solvent for PVOH, preferably soluble in an organic solvent. Suitable organic solvents include alcohols. The alcohol may include a primary alcohol, a secondary alcohol, or a tertiary alcohol; and preferably a primary alcohol. The alcohol may be methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, decanol, and isomers, derivatives, or combinations thereof. In a particularly preferred embodiment, the alcohol is ethanol. In a particularly preferred embodiment, the amphiphilic polymer of the coating and / or substantially the entire coating is soluble in a non-solvent for PVOH and is also soluble in water. The amphiphilic polymer of the coating and / or substantially the entire coating is soluble in alcohol, preferably ethanol, and is also soluble in water.

[0042] In some embodiments, the coating comprises a non-hydroxyl-functional polymer. In some embodiments, the coating comprises less than 10 wt % of a hydroxyl-functional polymer, or less than 9 wt %, 8 wt %, 7 wt %, 6 wt %, 5 wt %, 4 wt %, 3 wt %, 2 wt %, or less than 1 wt % of a hydroxyl-functional polymer. The coating may be substantially free of hydroxyl-functional polymers. The coating may be substantially free of PVOH.

[0043] In a preferred embodiment, the coating comprises at least one amphiphilic copolymer. The amphiphilic copolymer may comprise hydrophilic and hydrophobic monomer units. The at least one amphiphilic copolymer may comprise block, random, alternating, periodic and / or graft copolymers. In embodiments where the at least one amphiphilic copolymer comprises a block copolymer, the amphiphilic copolymer may comprise a diblock, triblock, tetrablock or pentablock copolymer.

[0044] In a preferred embodiment, the coating comprises at least one amphiphilic copolymer comprising at least one hydrophilic monomer and at least one hydrophobic monomer. The at least one hydrophilic monomer may be an acidic monomer, an anionic monomer or a combination thereof.

[0045] The coating may preferably include at least one amphiphilic copolymer, which includes at least one acidic / anionic monomer. At least one acidic / anionic monomer may preferably include vinyl anions / acidic monomers. At least one acidic / anionic monomer may include carboxylic acid-containing vinyl monomers or any salts or derivatives thereof. Carboxylic acid-containing vinyl monomers may include monocarboxylic acid vinyl monomers and / or dicarboxylic acid vinyl monomers. In some preferred embodiments, at least one acidic / anionic monomer is acrylic acid or alkylacrylic acid monomer, methacrylic acid monomer or its salt, crotonate monomer, maleic acid monomer or its monoester derivative, fumaric acid monomer or its monoester derivative, itaconic acid monomer or its monoester derivative, citraconic acid monomer or its monoester derivative, mesaconic acid monomer or its monoester derivative, glutaconic acid monomer or its monoester derivative, and any salt, derivative or combination thereof. In some embodiments, at least one acidic / anionic monomer includes vinyl sulfonic acid monomer or its salt or derivative. The vinyl sulfonic acid monomer can be 2-acrylamido-1-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), 2-methacrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl acrylate, or any salt, derivative, or combination thereof. In a particularly preferred embodiment, at least one acidic / anionic monomer is an acrylic acid or alkylacrylic acid monomer, a methacrylic acid monomer or a salt thereof, a crotonate monomer, a maleic acid monomer or a monoester derivative thereof, or any salt, derivative, or combination thereof. In some preferred embodiments, at least one acidic / anionic monomer is acrylic acid; a methacrylic acid monomer or a salt thereof, crotonic acid; maleic acid or a C1-C10 monoester thereof, preferably butyl maleate; or any salt, derivative, or combination thereof.

[0046] In some embodiments, the coating comprises at least one amphiphilic copolymer, and the amphiphilic copolymer comprises at least one vinyl hydrophobic monomer. In some embodiments, at least one hydrophobic monomer is olefin (alkylene), styrene, vinyl chloride, vinyl fluoride, acrylonitrile, alkyl acrylamide monomer, alkyl acrylate monomer, alkyl acrylate monomer, alkyl amino alkyl acrylate monomer, alkyl amino alkyl alkyl acrylate monomer, chain alkanoic acid vinyl ester monomer, vinyl alkyl ether monomer or its monoester derivative, vinyl pyrrolidone monomer or its derivative, alkylene glycol alkyl acrylate, or any salt, derivative or combination thereof. In a preferred embodiment, at least one hydrophobic monomer is alkyl acrylamide monomer, alkyl acrylate monomer, alkyl acrylate monomer, alkyl amino alkyl acrylate monomer, alkyl amino alkyl alkyl acrylate monomer, chain alkanoic acid vinyl ester monomer, vinyl alkyl ether monomer or its monoester derivative, vinyl pyrrolidone monomer or its derivative, alkylene glycol alkyl acrylate, or any salt, derivative or combination thereof. In some preferred embodiments, at least one hydrophobic monomer comprises a side chain containing a bulky group, preferably a branched alkyl group, and most preferably a tert-butyl group. In some preferred embodiments, at least one hydrophobic monomer is an octylacrylamide monomer, preferably tert-octylacrylamide; butylaminoethyl methacrylate monomer, preferably tert-butylaminoethyl methacrylate; methyl methacrylate monomer; alkylene glycol methacrylate monomer, preferably propylene glycol methacrylate; vinyl neodecanoate monomer; vinyl acetate monomer; tert-butylacrylamide monomer; ethyl acrylate monomer; vinyl methyl ether monomer or its monoester derivative, preferably vinyl methyl ether butyl monoester; or any salt, derivative or combination thereof.

[0047] The at least one amphiphilic copolymer of the coating may comprise at least two different monomers, preferably at least three different monomers. In some preferred embodiments, the at least one amphiphilic polymer comprises only one hydrophilic monomer and at least two different hydrophobic monomers.

[0048] In some preferred embodiments, at least one amphiphilic copolymer of the coating comprises an acrylic acid monomer or a salt or derivative thereof; and further comprises at least one hydrophobic monomer, wherein the hydrophobic monomer is an alkyl acrylamide monomer, an alkyl acrylate monomer, an alkyl acrylate monomer, an alkylaminoalkyl acrylate monomer, an alkylaminoalkyl acrylate monomer, a vinyl alkanoate monomer, a vinyl alkyl ether monomer or a monoester derivative thereof, a vinyl pyrrolidone monomer or a derivative thereof, an alkylene glycol alkyl acrylate, or any salt, derivative or combination thereof.

[0049] The at least one amphiphilic copolymer of the coating may preferably comprise an acrylic acid monomer or a salt or derivative thereof; and may further comprise at least one, preferably two, hydrophobic monomers, the hydrophobic monomers being an alkylaminoalkyl alkylacrylate, preferably an alkylaminoalkyl methacrylate monomer; an alkylacrylamide monomer; an alkylacrylate monomer; an alkylacrylate, preferably an alkylmethacrylate monomer; an alkanoic acid vinyl ester monomer; an alkylene glycol alkylacrylate, preferably an alkylene glycol methacrylate monomer; or any salt, derivative or combination thereof.

[0050] The at least one amphiphilic copolymer of the coating may preferably comprise an acrylic acid monomer or a salt or derivative thereof; and may further comprise at least one, preferably two, hydrophobic monomers, the hydrophobic monomers being octylacrylamide monomers, preferably tert-octylacrylamide; butylaminoethyl methacrylate monomers, preferably tert-butylaminoethyl methacrylate; methyl methacrylate monomers; alkylene glycol methacrylate monomers, preferably propylene glycol methacrylate; tert-butylacrylamide monomers; ethyl acrylate monomers; and any salts, derivatives, and combinations thereof.

[0051] In a particularly preferred embodiment, at least one amphiphilic copolymer of the coating comprises an acrylic acid monomer or a salt or derivative thereof; and further comprises at least one, preferably two, hydrophobic monomers, the hydrophobic monomers being octylacrylamide monomers, preferably tert-octylacrylamide; butylaminoethyl methacrylate monomers, preferably tert-butylaminoethyl methacrylate; or any salt, derivative, or combination thereof. In this specific embodiment, the amphiphilic copolymer may optionally further comprise at least one or two hydrophobic monomers, which are methyl methacrylate monomers; alkylene glycol methacrylate monomers, preferably propylene glycol methacrylate; or any salt, derivative, or combination thereof.

[0052] In another particularly preferred embodiment, at least one amphiphilic copolymer of the coating comprises acrylic acid monomers or salts or derivatives thereof; and further comprises at least one, preferably two, hydrophobic monomers, which are tert-butyl acrylamide monomers; ethyl acrylate monomers; or any salts, derivatives or combinations thereof.

[0053] In some preferred embodiments, at least one amphiphilic copolymer of the coating comprises a crotonic acid monomer or a salt or derivative thereof; and further comprises at least one hydrophobic monomer, which is an alkyl acrylamide monomer, an alkyl acrylate monomer, an alkyl acrylate monomer, an alkylaminoalkyl acrylate monomer, an alkylaminoalkyl acrylate monomer, a vinyl alkanoate monomer, a vinyl alkyl ether monomer or a monoester derivative thereof, a vinyl pyrrolidone monomer or a derivative thereof, an alkylene glycol alkyl acrylate, or any salt, derivative or combination thereof.

[0054] The at least one amphiphilic copolymer of the coating may preferably comprise a crotonic acid monomer, or a salt or derivative thereof; and may further comprise at least one, preferably two, hydrophobic vinyl alkanoate monomers, or any salt or derivative thereof.

[0055] In a particularly preferred embodiment, at least one amphiphilic copolymer of the coating comprises a crotonic acid monomer or a salt or derivative thereof; and further comprises at least one, preferably two, hydrophobic monomers, which are vinyl neodecanoate monomers, vinyl acetate monomers, or any salt, derivative or combination thereof.

[0056] In some preferred embodiments, at least one amphiphilic copolymer of the coating comprises: a maleic acid monomer; a C1-C10 monoester thereof, preferably butyl maleate; or a salt or derivative thereof; and the amphiphilic copolymer further comprises at least one hydrophobic monomer, the hydrophobic monomer being an alkyl acrylamide monomer, an alkyl acrylate monomer, an alkyl acrylate alkyl ester monomer, an alkylaminoalkyl acrylate monomer, an alkylaminoalkyl acrylate monomer, a vinyl alkanoate monomer, a vinyl alkyl ether monomer or a monoester derivative thereof, a vinyl pyrrolidone monomer or a derivative thereof, an alkylene glycol alkyl acrylate, or any salt, derivative or combination thereof.

[0057] In a particularly preferred embodiment, at least one amphiphilic copolymer of the coating comprises: a maleic acid monomer; a C1-C10 monoester thereof, preferably butyl maleate; or a salt or derivative thereof; and the amphiphilic copolymer further comprises at least one vinyl alkyl ether hydrophobic monomer or a monoester derivative thereof, or any salt or derivative thereof. The vinyl alkyl ether hydrophobic monomer or a monoester derivative thereof preferably comprises vinyl methyl ether or vinyl methyl ether butyl monoester.

[0058] In some embodiments, the water-soluble film of the coating has a transparency of at least 50% of the uncoated base film, or at least 60%, 70%, 80%, 90% or at least 95% of the uncoated base film. In some embodiments, the water-soluble film of the coating is as transparent as the uncoated base film. In some embodiments, the water-soluble base film of the coating is more transparent than the uncoated base film.

[0059] In some embodiments, the coated water-soluble film optionally comprises one or more additional ingredients, such as surfactants, colorants, plasticizers, antioxidants, acid scavengers, fillers, defoamers, and combinations thereof.

[0060] The water-soluble film of coating may include any suitable plasticizer. Plasticizer is liquid, solid or semisolid, added to the material to make the material softer, more flexible (by reducing the glass transition temperature of the polymer) or easier to process. Plasticizer may include but is not limited to one or more of the following groups: glycerol, diglycerol, sorbitol, ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol with a molecular weight of up to 400Da, hexylene glycol, neopentyl glycol, trimethylolpropane, polyether polyol, polyether diol, polyether triol, xylitol, 2-methyl-1,3-propanediol Ethanolamine, glycerol propylene oxide polymer (such as Voranol available from Dow Chemical Company) TM ) or a combination thereof.

[0061] In embodiments where the coated water-soluble film comprises a plasticizer, the plasticizer may be provided in an amount from about 1 wt % to about 45 wt %, or from about 5 wt % to about 35 wt %, or from about 7.5 wt % to about 30 wt %, or from about 8 wt % to about 20 wt %, or from about 8 wt % to about 12 wt %, based on the weight of the coated film.

[0062] The coated water-soluble film may contain any suitable acid scavenger. The acid scavenger may include, but is not limited to, one or more of the following groups: N-vinyl pyrrolidone, sodium metabisulfite, activated olefins, maleate molecules (e.g., maleic acid and its derivatives), allyl compounds (e.g., allyl alcohol, allyl acetate, etc.), vinyl-containing compounds, quaternary ammonium compounds, amines (e.g., pyridine, monoethanolamine, methylamine, aniline), tertiary amine-containing compounds, and combinations thereof.

[0063] The water-soluble film of coating can comprise any suitable antioxidant and / or chlorine scavenger.Antioxidant / chlorine scavenger can include but is not limited to comprise one or more in the following group: sulfite, bisulfite, thiosulfate, thiosulfite, iodide, nitrite, carbamate, ascorbate, propyl gallate, gallic acid, citric acid, sodium metabisulfite, carbamate, phenolic compound, hindered amine, zinc acetate, sulfate, bisulfate, carbonate, bicarbonate, nitrate, chloride, borate, phosphate, condensed phosphate, acetate, benzoate, citrate, formates, lactate, salicylate and combination thereof.Antioxidant / chlorine scavenger can exist with the amount of 0.25 % by weight to 5 % by weight, or 0.5 % by weight to 2.5 % by weight, or 1 % by weight to 2 % by weight.

[0064] The coated water-soluble film may further contain other adjuvants and processing agents, such as, but not limited to, surfactants, lubricants, mold release agents, fillers, extenders, cross-linking agents, anti-caking agents, detackifying agents, defoaming agents, nanoparticles such as layered silicate nanoclays (e.g., sodium montmorillonite), bleaching agents (e.g., sodium metabisulfite, sodium bisulfate (SBS) or others), aversive agents such as bittering agents (e.g., denatonium salts such as denatonium benzoate, denatonium sugar and denatonium chloride; sucrose octaacetate; quinine; flavonoids such as quercetin and naringenin; and quasin bitters such as quassin and dimethoxystrychnine (bmcine)) and pungents (e.g., capsaicin, piperine, allyl isothiocyanate and resinferatoxin), and other functional ingredients in amounts suitable for their intended purposes.

[0065] The water-soluble film of coating can comprise any suitable surfactant.Surfactant can include but is not limited to one or more in the following group: dialkyl sulfosuccinate, lactylated fatty acid ester of glycerol and propylene glycol, lactylated ester of fatty acid, sodium alkyl sulfate, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, alkyl polyethylene glycol ether, lecithin, acetylated fatty acid ester of glycerol and propylene glycol, sodium lauryl sulfate, acetylated ester of fatty acid, myristyl dimethylamine oxide, trimethyl tallow alkyl ammonium chloride, quaternary ammonium compound, and salt or combination thereof.

[0066] The coated water-soluble film may contain any suitable defoaming agent. The defoaming agent may include, but is not limited to, one or more of the group consisting of: hydrophobic silica, such as fine-grained silica or fumed silica, including Foam available from Emerald Performance Materials. Defoamers, including Foam 327. Foam UVD、Foam 163. Foam 269. Foam 338. Foam 290. Foam 332. Foam 349. Foam 550、Foam 339 and combinations thereof.

[0067] Suitable fillers / bulking agents / anti-caking agents / anti-adherents in the water-soluble films for coating include, but are not limited to, one or more of the group comprising starch, modified starch, cross-linked polyvinyl pyrrolidone, cross-linked cellulose, microcrystalline cellulose, silicon dioxide, metal oxides, calcium carbonate, talc, mica, stearic acid and salts thereof or combinations thereof. In some embodiments, the amount of filler / bulking agent / anti-caking agent / anti-adherent in the water-soluble films for coating may be, for example, in the range of about 0 wt % to about 10 wt %, or about 0 wt % to about 8 wt %, or about 0 wt % to about 7.5 wt %.

[0068] The water-soluble film of coating can comprise one or more other water-soluble polymers, it includes but is not limited to one or more comprising the following group: polyvinyl alcohol, water-soluble acrylate copolymer, polyethyleneimine, pullulan, water-soluble natural polymer, including but not limited to guar gum, gum arabic, xanthan gum, carrageenan and starch, water-soluble polymer modified starch, and copolymer, blend or combination thereof.Other water-soluble polymer can be selected from the group comprising the following: polyalkylene oxide, polyacrylamide, cellulose, cellulose ether, cellulose ester, cellulose amide, polyvinyl acetate, polycarboxylic acid and its salt, polyamino acid, polyamide, gelatin, methylcellulose, carboxymethylcellulose and its salt, dextrin, ethylcellulose, hydroxyethylcellulose, hydroxypropyl methylcellulose, maltodextrin, polymethacrylate, and copolymer, blend or combination thereof.

[0069] According to a second aspect of the present invention, there is provided a water-soluble unit dose product comprising a composition packaged in a container, the container comprising the coated water-soluble film of the first aspect of the present invention.

[0070] The above statements regarding the coated water-soluble film of the first aspect of the invention are also applicable to the second aspect of the invention.

[0071] When any component of the coated water-soluble film previously mentioned in the first aspect of the invention is mentioned in the second aspect of the invention, the inventive statements concerning the components of the first aspect of the invention are equally applicable.

[0072] In some embodiments, the composition comprises a reactive chemical, such as an acid, an oxidizing agent, a base, a bleach, an aldehyde, or a combination thereof.

[0073] The composition may include at least one oxidizing agent, such as hypochlorite, halogenated isocyanurate, chlorate, chlorite, perchlorate, bromate, perbromate, halogenated hydantoin, borate, perborate, periodate, persulfate, permanganate, chromate, dichromate, nitrate, nitrite, peroxide, ketone peroxide, peroxyacid, superoxide, halogen (such as bromine, chlorine, iodine and fluorine), inorganic acid, or any salt, hydrate or combination thereof. In some embodiments, the oxidizing agent includes one or more of the following groups: trichloroisocyanic acid, triisocyanuric acid, diisocyanuric acid, 1-bromo-3-chloro-5,5-dimethylhydantoin, calcium hypochlorite, potassium permonosulfate, and any salt, hydrate or combination thereof.

[0074] In some embodiments, the composition comprises at least one base. The base can be a hydroxide, carbonate, oxide, bicarbonate, amine or ammonia, or any salt, derivative or combination thereof.

[0075] In a preferred embodiment, the composition comprises at least one acid-reactive chemical. In some embodiments, the composition comprises an inorganic acid. The inorganic acid can be a hydrogen halide, a halogen oxygen acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, or any derivative, or a combination thereof. The acid-reactive chemical may preferably comprise a solid acid. The acid-reactive chemical may preferably comprise an organic acid. The acid-reactive chemical may comprise a carboxylic acid group, preferably more than one carboxylic acid group. In a preferred embodiment, the acid-reactive chemical may be citric acid, gluconic acid, glycolic acid, levulinic acid, oxalic acid, acetic acid, tartaric acid, or any salt, derivative, or combination thereof. In a particularly preferred embodiment, the composition comprises citric acid, preferably solid citric acid.

[0076] The composition can be solid, liquid or a combination thereof. "Liquid" can include free-flowing liquids, as well as pastes, gels, foams and mousses. Gases, such as suspended bubbles, or solids, such as particles, can be contained in a liquid. "Solid" can include, but is not limited to, powders, agglomerates, particles, microcapsules, beads, tablets, bars and balls. In a preferred embodiment, the composition comprises at least one solid reactive chemical. Preferably, the entire composition can be solid.

[0077] In some embodiments, the reactive chemical is present in an amount of at least 0.5% by weight of the composition, or at least 1%, 2%, 3%, 4%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or at least 95% by weight of the composition. In some embodiments, the composition can be composed entirely of reactive chemicals. In some embodiments, the reactive chemical is present in an amount of no more than 98% by weight of the composition, or no more than 96%, 94%, 92%, 90%, 88%, 86%, 84%, 82%, or no more than 80% by weight of the composition.

[0078] In some embodiments, the composition is present in an amount of at least 5% by weight of the water-soluble unit dose preparation, or at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or at least 95% by weight of the water-soluble unit dose preparation. In some embodiments, the composition is present in an amount of no more than 98% by weight of the water-soluble unit dose preparation, or no more than 96%, 94%, 92%, 90%, 88%, 86%, 84%, 82 or no more than 80% by weight of the water-soluble unit dose preparation.

[0079] In some embodiments, the coated water-soluble film is in direct contact with the composition or at least a portion thereof. The component preferably comprises at least one reactive chemical. In embodiments in which the water-soluble film is only partially coated with at least one amphiphilic polymer, the uncoated portion of the film is preferably not in direct contact with the composition or at least not in direct contact with the portion of the composition comprising at least one reactive chemical.

[0080] In some embodiments, the container comprises a coated water-soluble film in the form of a sheet. The sheet may have two faces. Both faces of the sheet may comprise an amphiphilic polymer coating. In a preferred embodiment, only one face of the sheet may comprise an amphiphilic polymer coating, and only the face may contact the composition in use. In some embodiments, the container comprises a monolithic coated water-soluble film, the water-soluble film being folded upon itself and sealed at its edges to define an internal cavity containing the composition therein.

[0081] In some embodiments, the container comprises more than one water-soluble film, at least one of which is coated. The container may include two water-soluble films, preferably in sheet form. Only one or two films may be coated. Only one or both sides of one or more sheets may include an amphiphilic polymer coating. In some embodiments, both films are coated, preferably preferably only coating two films on the surface of the sheet that can contact the composition in use. In a preferred embodiment, the container comprises two water-soluble films sealed together to define an inner cavity containing a composition. In such an embodiment, the portion of the film facing the composition contained in the inner cavity is preferably coated with at least one amphiphilic polymer. The portion of the film not facing the composition contained in the inner cavity may not be coated.

[0082] The container can be a bag, a bag, a pouch, a packet, etc. In some embodiments, the container is a multi-compartment container. The multi-compartment container may include more than two, more than three, more than four, more than five, or more than six separate compartments. Each compartment can be arranged side by side, concentrically as a circular sector or in any suitable random or organized pattern. The container may include a first water-soluble film and a second water-soluble film, wherein the first water-soluble film includes a bag and a surrounding flange, and the second water-soluble film is applied to the bag as a cover and sealed on the flange. The container may include a first water-soluble film and a second water-soluble film, wherein the first water-soluble film includes more than one bag (e.g., more than two, more than three, more than four, more than five, or more than six bags) and a surrounding flange, and the second water-soluble film is applied to each bag as a cover and sealed on the flange. In some embodiments, there are three or four bags.

[0083] In some embodiments, the coated water-soluble film of the present invention comprises at least 5% by weight of the container, or comprises at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or at least 95% by weight of the container. In some embodiments, the coated water-soluble film of the present invention substantially constitutes the entire container.

[0084] In some embodiments, the container has an average maximum dimension of at least 0.1 cm, or at least 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or at least 10 cm. The container may have an average maximum dimension of no more than 100 cm, or no more than 90, 80, 70, 60, or no more than 50 cm. The container may have an average maximum dimension of 1 to 80 cm, or 2 to 60 cm, or 4 to 40 cm, or 5 to 30 cm.

[0085] The container can define an inner chamber in which the composition is held in use. The inner chamber can define a volume of at least 1 mL, or at least 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, or at least 50 mL. The inner chamber can define a volume of no more than 5 L, or no more than 4.5, 4, 3.5, 3, 2.5, 2, 1.5, or no more than 1 L. The inner chamber can define a volume of 1 to 1000 mL, or 5 to 800 mL, or 5 to 500 mL, or 5 to 400 mL, or 5 to 300 mL, or 5 to 200 mL, or 5 to 150 mL, or 5 to 100 mL, or 5 to 75 mL, or 5 to 50 mL, or 5 to 25 mL.

[0086] In some embodiments, the water-soluble unit dose product is a cleaning product. The water-soluble unit dose product can be, but is not limited to, a hard surface cleaner (preferably an acidic hard surface cleaner), a descaling agent, a dishwasher detergent, a toilet cleaner, a household care composition, or a multi-purpose cleaner. The water-soluble unit dose product can be a household product or an industrial product. The water-soluble unit dose product can be a refill cleaning product. The water-soluble unit dose product can be diluted with water before use to release the contained composition from the container. When it is necessary to use the composition in a specific dose and then dilute it before use, the water-soluble unit dose product of the present invention can have a specific application.

[0087] The water-soluble unit dose preparation may have a shelf life of at least 3 weeks, or at least 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, or at least 10 weeks. The water-soluble unit dose preparation may have a shelf life of at least several months, or at least one year, or more than one year, or several years.

[0088] According to a third aspect of the present invention, there is provided the use of the water-soluble unit dose product of the second aspect of the present invention as a hard surface cleaner, descaling agent, toilet cleaner, dishwasher cleaner, household care composition or multi-purpose cleaner.

[0089] The above statements regarding the water-soluble unit dose product of the second aspect of the invention, or any component thereof, are also applicable to the third aspect of the invention.

[0090] In some embodiments, the water-soluble unit dose product is diluted with water before use. This preferably dissolves at least a portion of the coated water-soluble film and releases the contained composition from the container into the water. The composition may contain a solid or be a solid. The composition may be dissolved in water to produce a treatment composition. The treatment composition may be applied to a hard surface to clean the hard surface.

[0091] Many known hard surface cleaners contain large amounts of water, which unnecessarily increases the CO2 footprint during transportation. The present invention allows for the provision of a solid cleaner which can simply be diluted with water before use.

[0092] Hard surface cleaners or descaling agents may be used on one or more surfaces, including metal surfaces, glass surfaces, ceramic surfaces, wood surfaces, plastic surfaces and surfaces containing more than one material type.

[0093] In embodiments where the water-soluble unit dose article is used as a dishwasher cleaner, the unit dose article may be added to the machine during a dummy wash or rinse cycle when the dishwasher is substantially free of dishware. In other embodiments, the unit dose article may be added to the machine during a normal wash or rinse cycle when the dishwasher contains dishware for cleaning. The unit dose article may contain a dosage of a dishwasher cleaning composition suitable for cleaning a dishwasher in a single application.

[0094] A water-soluble unit dose preparation for use as a toilet cleaner can be added to a toilet bowl, and the toilet bowl can be flushed to clean the toilet. The unit dose preparation can contain a dosage of the toilet cleaning composition suitable for cleaning a toilet bowl in a single application.

[0095] According to a fourth aspect of the present invention, there is provided a method for preparing the coated water-soluble film of the first aspect of the present invention, the method comprising the following steps:

[0096] a. Providing a water-soluble polymer base film; and

[0097] b. Coating the base membrane with at least one amphiphilic polymer.

[0098] The above statements regarding the coated water-soluble film or any component thereof of the first aspect of the invention are also applicable to the fourth aspect of the invention.

[0099] Where any component of the coated water-soluble film previously mentioned in the first aspect of the invention is mentioned in the fourth aspect of the invention, the inventive statements regarding the components of the first aspect of the invention may equally apply.

[0100] Step (a) may include preparing the water-soluble polymer base film using any suitable method. Suitable methods may include, but are not limited to, solution casting, film casting, wet film forming, dry film forming, film extrusion, melt film forming, coating, and blown film.

[0101] In some embodiments, step (a) includes forming the base film by solution casting. The method may include preparing an aqueous solution of the base film components. The aqueous solution may then be spread on the surface to a predetermined thickness. This step may include adding the aqueous solution to a forming belt and preferably spreading it on the belt to a predetermined thickness with a scraper. The aqueous solution is then heated (preferably in an oven) to reduce the moisture content (preferably to a moisture content of 6 to 15%) and prepare the base film.

[0102] In some embodiments, step (b) of the method comprises coating the base film with at least one amphiphilic polymer using vapor deposition, chemical coating, spraying, roll-to-roll coating, physical coating, or a combination thereof. Suitable vapor deposition coating methods may include, but are not limited to, chemical vapor deposition methods such as metal organic vapor phase epitaxy, electrostatic spray assisted vapor deposition and epitaxy. Suitable roll-to-roll coating methods may include, but are not limited to, air knife coating, anilox coating, flexographic coating, gap coating, knife-over-roll coating, gravure coating, hot melt coating, dip coating, kiss coating, Meyer rod coating, roll coating (forward roll coating and reverse roll coating), screen coating, rotary screen coating, slot die coating, extrusion coating, curtain coating, slide coating, slot die bead coating, tensioned-web slot die coating, inkjet printing, lithography, and flexographic printing. Suitable physical coating methods may include, but are not limited to, Langmuir-Blodgett coating / spin coating and dip coating.

[0103] In a preferred embodiment, step (b) of the method comprises spraying the base film with at least one amphiphilic polymer. The spraying method for this step can be spraying, thermal spraying or a combination thereof. In some embodiments, step (b) comprises spraying the base film at a temperature of at least 10°C, or at least 12°C, 14°C, 16°C, 18°C, 20°C, 22°C or at least 24°C. The method may comprise spraying the base film at a temperature of not more than 200°C, or not more than 180°C, 160°C, 140°C, 120°C, 100°C, 80°C, 60°C or not more than 40°C.

[0104] In a preferred embodiment, step (b) of the method includes dissolving at least one amphiphilic polymer in a solvent to form a solution, and then spraying the base film with the solution. The solvent may preferably include a non-solvent for the base film, preferably a non-solvent for PVOH. The solvent may include an organic solvent, preferably an alcohol as described in the first aspect of the present invention. In a specific embodiment, the solvent includes ethanol. In some embodiments, the total concentration of the amphiphilic polymer of the solution is at least 0.01 weight %, or at least 0.02 weight %, 0.03 weight %, 0.04 weight %, 0.05 weight %, 0.06 weight %, 0.07 weight %, 0.08 weight %, 0.09 weight %, 0.1 weight %, 0.2 weight %, 0.3 weight %, 0.4 weight %, or at least 0.5 weight %. In some embodiments, the total amphiphilic polymer concentration of the solution is not more than 50 weight %, or not more than 45 weight %, 40 weight %, 35 weight %, 30 weight %, 25 weight %, 20 weight %, 15 weight %, or not more than 10 weight %. The total amphiphilic polymer concentration of the solution may be from 0.01 to 50 wt%, or from 0.05 to 40 wt%, or preferably from 0.1 to 30 wt%, or from 0.2 to 20 wt%, or from 0.3 to 15 wt%, or most preferably from 1 to 5 wt%.

[0105] In some preferred embodiments, the method also includes the step of neutralizing the amphiphilic polymer solution before spraying the base film. The method may include neutralizing the solution with at least one base, preferably with at least one amine base. The method may include neutralizing the solution with at least one amine base, the amine base being a primary amine, a secondary amine, a tertiary amine or a combination thereof. The amine base may include one or more groups, the groups comprising: aliphatic amines, aromatic amines, cyclic amines and combinations thereof. In some embodiments, the amine base is an alkylamine, a dialkylamine, a trialkylamine, an aniline, a hydroxyl-containing amine, a diamine, a polyamine or a combination thereof. In a preferred embodiment, the amine base is a hydroxyl-containing amine, a diamine or a combination thereof. Preferred specific bases may include, but are not limited to, one or more of the group consisting of 2-amino-2-methyl-1-propanol (AMP), N,N-diethyl-1,3-diaminopropane, 1,1′,1″-nitrilotri(propan-2-ol), 2-amino-2-methyl-1,3-propanediol, 1-aminopropan-2-ol, N,N-dimethyl-1-octadecylamine, 2-aminoethan-1-ol, 3-(diethylamino)propylamine (DEPA), triisopropanolamine (TIPA), triethanolamine, and combinations thereof.

[0106] In some embodiments, the pKa value of the base in its protonated form is at least 4, or at least 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or at least 8. The pKa value of the protonated form of the base may be no greater than 20, or no greater than 19, 18, 17, 16, 15, 14, 13, 12, or no greater than 11. The pKa value of the protonated form of the base may be from 4 to 20, or from 4 to 15, or from 5 to 14, or from 6 to 13, or from 7 to 12, or from 8 to 11.

[0107] In some embodiments, the method comprises the step of neutralizing the amphiphilic polymer solution to a pH of at least 4, or at least 4.5, 5, 5.5, 6, 6.5, 7, or at least 7.5. The method may comprise the step of neutralizing the amphiphilic polymer solution to a pH of no greater than 12, or no greater than 11.5, 11, 10.5, 10, 9.5, or no greater than 9. The method may comprise the step of neutralizing the amphiphilic polymer solution to a pH of 4 to 12, or 5 to 11, or preferably 6 to 10, or 7 to 9.5, or most preferably 7.5 to 9. In some embodiments, the method comprises deprotonating at least 1%, or at least 2%, 3%, 4%, 5%, 10%, 15%, or preferably at least 20%, or at least 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or at least 95% of the acidic hydrogen atoms in the or each amphiphilic polymer. The method may comprise deprotonating substantially 100% of the acidic hydrogen atoms in the or each amphiphilic polymer. In some embodiments, the method may comprise deprotonating no more than 98% of the acidic hydrogen atoms in the or each amphiphilic polymer, or no more than 96%, 94%, 92%, 90%, 88%, 86%, 84%, 82%, or no more than 80% of the acidic hydrogen atoms in the or each amphiphilic polymer.

[0108] Step (b) preferably comprises producing a coating of at least one amphiphilic polymer on the base film as described in the first aspect of the present invention.

[0109] In some embodiments, the method further includes a step of drying the coated film after step (b). The drying step may include oven drying or may preferably include air drying the coated film. The method may include drying the coated film at a temperature of at least 10°C, or at least 12°C, 14°C, 16°C, 18°C, 20°C, 22°C, or at least 24°C. The method may include drying the coated film at a temperature of not more than 200°C, or not more than 180°C, 160°C, 140°C, 120°C, 100°C, 80°C, 60°C, or not more than 40°C. In a preferred embodiment, the method includes air drying the coated film at room temperature and ambient pressure. In some embodiments, the method comprises drying the coated film preferably at room temperature for at least 30 seconds, or at least 1 minute, or at least 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, or at least 55 minutes, or at least 1 hour, or at least 2, 3, 4, 5, 10, 15, or at least 20 hours, or at least 1 day. The method may comprise drying the coated film (preferably at room temperature) for no more than 4 weeks, or no more than 3, 2 or no more than 1 week, or no more than 6 days, or no more than 5, 4, 3 or no more than 2 days.

[0110] According to a fifth aspect of the present invention, there is provided a method for preparing the water-soluble unit dose product of the second aspect of the present invention, the method comprising the steps of packaging the composition in a container comprising the coated water-soluble film of the first aspect of the present invention.

[0111] The above statements regarding the coated water-soluble film or any component thereof of the first aspect of the invention are also applicable to the fifth aspect of the invention.

[0112] The above statements regarding the water-soluble unit dose product of the second aspect of the invention, or any component thereof, are also applicable to the fifth aspect of the invention.

[0113] The coated water-soluble film may be prepared by the method of the fourth aspect of the present invention.

[0114] When any component of the coated water-soluble film previously mentioned in the first aspect of the invention or any component of the water-soluble unit dose product of the second aspect of the invention is mentioned in the fifth aspect of the invention, the inventive statements concerning the corresponding components of the first and second aspects of the invention are equally applicable.

[0115] In some embodiments, the method includes the step of forming a container comprising a coated water-soluble film before packaging the composition in the container. The step of forming the container may include forming the container from a single sheet of coated water-soluble film or from two or more sheets of coated water-soluble film.

[0116] The step of forming a container from a single sheet of coated film may include: folding the single sheet of coated water-soluble film onto itself; and in use, sealing the folded sheet at the edges of the folded sheet to define an inner cavity in which the composition can be contained. In some embodiments, the sheet may not be completely sealed in this step to allow the composition to be inserted into the inner cavity before the sheet is completely sealed. In one embodiment, the method may include folding the single sheet onto itself; and sealing the folded sheet on the edge opposite to the fold and along one of the two remaining open edges to provide an open container.

[0117] In a preferred embodiment, the method comprises the step of forming a container using two water-soluble films, wherein at least one film is a coated film of the present invention, as described in the second aspect of the present invention. The method may comprise the step of sealing two films (preferably in sheet form) together to define an inner cavity in which the composition may be contained.

[0118] In some embodiments, the method comprises stretching a coated water-soluble film over a cavity of a specified size; and heating the film under vacuum to form the film into the shape of the cavity. Thereafter, the method may include filling the exposed cavity (open container) of the film with the composition, followed by sealing the exposed cavity with a second film. During the sealing step, the second film may be pulled over the top of the exposed cavity, and the edge of the second film may be sealed to the edge of the first film to provide a sealed container.

[0119] Any suitable known method and machine may be used to form and seal containers comprising the coated water-soluble film of the present invention. Suitable methods include, but are not limited to: vertical form fill seal (VFFS); thermoforming; solvent seal; and heat sealing. DETAILED DESCRIPTION

[0120] In order that the present invention may be more clearly understood, embodiments of the present invention will now be described by way of example only.

[0121] Example

[0122] Example 1 - Preparation of a coated water-soluble film of the present invention

[0123] The coating solution was prepared by dissolving the amphiphilic copolymers as described in Table 1 below in ethanol at a concentration of 0.5 to 10 wt%. The solution was then neutralized with aminomethylpropanolamine base until the pH of the resulting solution was between 7.5 and 9. Ethanol was chosen as the solvent for the coating solution due to the insolubility of PVOH in ethanol. This allowed the PVOH-based film to be coated with the polymer solution without dissolving the PVOH and disintegrating the base film.

[0124] The coating solution was applied to the PVOH (from Aicello) film by spraying it with the coating solution. GA film, thickness 90 μm). The coated film was then dried at room temperature.

[0125] This process produces a thin layer of amphiphilic copolymer coating on the PVOH base film. The integrity and uniformity of the coating is determined by the uniform increase in film thickness from before coating to after coating. The polymer coating load and coating thickness were measured / calculated (using a constant pressure thickness gauge, Peacock FFA-1 1.25) and are recorded in Table 1 below.

[0126] Table 1

[0127]

[0128] Example 2 - Preparation and stability testing of citric acid pouches

[0129] Eight different pouches were prepared using eight different PVOH films; including four amphiphilic polymer coated PVOH films of the present invention (films 1-4), one uncoated PVOH film (film 5), and three PVOH films coated with a hydrophilic material (films 6-8).

[0130] The following uncoated and hydrophilic material coated membranes were used as controls:-

[0131] Film 5: Uncoated GAPVOH film.

[0132] Film 6: PVOH modified by a gelatin layer. A gelatin film with a thickness of 20 μm was prepared via solution casting by means of a film coater COATMASTER 510 from ERICHSEN. When preparing the pouch, the gelatin film was placed between the PVOH and the citric acid.

[0133] Membrane 7: PVOH modified with hydrophilic bentonite. 5 g GAPVOH and 6.25 g of hydrophilic bentonite were dissolved in 20 g of water. The mixture was homogenized and applied to the existing The resulting coating had a rough surface and a thickness of 20 μm.

[0134] Film 8: PVOH modified with cellulose microcrystals. 5g GAPVOH and 6.25 g of microcrystalline cellulose were dissolved in 20 g of water. The mixture was homogenized and applied to the existing The resulting coating had a smooth surface and a thickness of 20 μm.

[0135] About 4 g of citric acid granules were filled into each of eight pouches, and the pouches were sealed at 160°C.

[0136] Several pouches of film 1 were placed together in a single doypack. The same procedure was followed for each pouch of film 2 to 8, which were also placed in their own doypack. The doypacks were stored at 40°C and 75% room humidity for up to 6 weeks.

[0137] Aesthetics and solubility evaluations were performed and the results are reported in Table 2.

[0138] Table 2

[0139]

[0140] a) Aesthetic evaluation: 5 - smooth pouch surface; 4 - slightly pitted pouch surface; 3 - sticky pouch with pitted surface; 2 - the pouches stick together and are difficult to open without destroying the pouches; 1 - the pouches stick together and are difficult to open.

[0141] b) Solubility evaluation: 5 - dissolved at 25°C; 4 - dissolved at 40°C; 3 - dissolved at 60°C; 2 - dissolved at 80°C; 1 - insoluble at 80°C.

[0142] *Discontinued storage at 3 weeks due to low review scores.

[0143] Summary of results

[0144] The amphiphilic coating (films 1-4) helps to form a barrier layer, blocking the contact between PVOH and citric acid. Therefore, PVOH is protected from undesirable reaction with citric acid during storage, and thus the film maintains good solubility.

[0145] The films of the invention containing octylacrylamide / acrylate / butylaminoethyl methacrylate copolymers, acrylate / tert-butylacrylamide copolymers or butyl ester of vinyl methyl ether / maleic acid copolymers (films 1, 2 and 4) retain solubility even after long-term storage, even in cold water. These films also advantageously completely disintegrate when the film is dissolved.

[0146] Although the vinyl acetate / crotonate / vinyl neodecanoate copolymer (Film 3) coating could not completely prevent the crosslinking reaction between PVOH and citric acid from occurring, it was able to slow the reaction down to allow for reasonable solubility after long-term storage.

[0147] Uncoated PVOH and PVOH modified with hydrophilic materials (films 5-8) reacted readily with citric acid and became completely water-insoluble after only 3 weeks of storage.

[0148] In summary, a thin layer of amphiphilic polymer coating on PVOH brings aesthetic and solubility benefits to the PVOH / citric acid pouch, namely, non-stickiness and retained solubility.

[0149] The present invention not only solves the compatibility problem of PVOH and citric acid, but also provides insight into improving the compatibility of PVOH with other reactive chemicals, allowing the development of many new valuable formulations and products.

[0150] The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the present invention as defined in the appended claims.

Claims

1. A coated water-soluble film comprising a water-soluble polymer base film and a water-soluble coating comprising at least one amphiphilic polymer; wherein the base film comprises polyvinyl alcohol, preferably in an amount of at least 50% by weight of the base film.

2. The coated water-soluble film according to claim 1, wherein The coating is present on the surface of the base film, preferably on at least 50% of the surface; and / or wherein the coating is uniformly distributed on the surface of the film, preferably with a loading of 0.2 mg / cm 2 Up to 5mg / cm 2 .

3. The coated water-soluble film according to claim 1 or 2, wherein The base film has a thickness of at least 40 μm.

4. A coated water-soluble film according to any one of the preceding claims, wherein The polymer coating comprises a layer having a thickness of no more than 40 μm.

5. A coated water-soluble film according to any one of the preceding claims, wherein The coating comprises an amphiphilic copolymer.

6. The coated water-soluble film according to claim 5, wherein The coating comprises at least one amphiphilic copolymer comprising at least one hydrophilic monomer that is an acidic monomer, an anionic monomer, or a combination thereof; and further comprising at least one hydrophobic monomer.

7. The coated water-soluble film according to claim 6, wherein The at least one hydrophilic monomer comprises at least one acidic monomer or at least one anionic monomer, wherein the at least one acidic monomer or at least one anionic monomer is an acrylic acid or alkylacrylic acid monomer, a methacrylic acid monomer or a salt thereof, a crotonate monomer, a maleic acid monomer or a monoester derivative thereof, or any salt, derivative or combination thereof.

8. The coated water-soluble film according to claim 6 or 7, wherein The at least one hydrophobic monomer is an alkyl acrylamide monomer, an alkyl acrylate monomer, an alkyl acrylate monomer, an alkylaminoalkyl acrylate monomer, an alkylaminoalkyl acrylate monomer, a vinyl alkanoate monomer, a vinyl alkyl ether monomer or a monoester derivative thereof, a vinyl pyrrolidone monomer or a derivative thereof, an alkyl acrylate alkyl glycol ester, or any salt, derivative or combination thereof; wherein the coating preferably comprises a non-hydroxyl functionalized polymer.

9. A water-soluble unit dose product comprising a composition packaged in a container, the container comprising a coated water-soluble film as claimed in any one of the preceding claims, wherein preferably the container comprises two of the water-soluble films sealed together to define an inner cavity in which the composition is contained.

10. The water-soluble unit dose product of claim 9, wherein: The composition comprises a reactive chemical, such as an acid, an oxidizing agent, a base, a bleach, an aldehyde, or a combination thereof; wherein the reactive chemical preferably comprises a solid acid having more than one carboxylic acid group, preferably citric acid.

11. The water-soluble unit dose product according to any one of claims 9 and 10, wherein The coated water-soluble film is in direct contact with the composition.

12. Use of the water-soluble unit dose preparation of any one of claims 9 to 11 as a hard surface cleaner, descaling agent, toilet cleaner, dishwasher cleaner, household care composition or multi-purpose cleaner.

13. A method for preparing a coated water-soluble film as claimed in any one of claims 1 to 8, the method comprising the steps of: a. Providing a water-soluble polymer base film; and b. Coating the base film with at least one amphiphilic polymer.

14. The method for preparing a coated water-soluble film according to claim 13, wherein step (b) comprises spraying the base film with the at least one amphiphilic polymer.

15. The method for preparing a coated water-soluble film according to claim 13 or 14, wherein the following method steps performed in sequence are additionally included between method steps (a) and (b): i) providing an amphiphilic polymer, ii) dissolving the amphiphilic polymer in a non-aqueous solvent; preferably in an alcohol or a mixture of at least two alcohols; and more preferably in a mixture of at least two alcohols, wherein one of the at least two alcohols is ethanol, iii) neutralizing the resulting amphiphilic polymer solution, in particular by adding an amine; wherein the degree of neutralization is preferably from 40 to 100%, more preferably from 60 to 100%, most preferably from 60 to 80%.

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