Package for an automatic dishwashing detergent and method for its manufacture

Abstract

The invention relates to a water-soluble polyvinyl alcohol (PVOH) package comprising at least a first compartment and a second compartment separated from the first compartment, the first compartment containing a first automatic dishwashing detergent composition for release during a dishwashing cycle, wherein the first automatic dishwashing detergent composition is a water-free liquid, gel or suspension, and wherein the first automatic dishwashing detergent composition comprises a polycarboxylic acid or polyaldehyde solubilised in a polar organic solvent in a weight ratio of polar organic solvent to polycarboxylic acid or polyaldehyde of at least 1 :1. The invention further relates to a method for the manufacture of a water-soluble polyvinyl alcohol (PVOH) package, the method comprising: i) providing a composition in the form of a water-free liquid, gel or suspension comprising one or more ADW active ingredients; ii) dissolving a polycarboxylic acid or polyaldehyde in a polar organic solvent to form a crosslinking component; iii) mixing the crosslinking component with the composition to form a first automatic dishwashing detergent composition; and iv) filling the first automatic dishwashing detergent composition into a first compartment of a water-soluble polyvinyl alcohol (PVOH) package comprising a first compartment and a second compartment separated from the first compartment.

Description

[0001] Package for an automatic dishwashing detergent and method for its manufacture

[0002] The present invention relates to a package for an automatic dishwashing (ADW) detergent and method for its manufacture. In particular, the invention relates to a standard polyvinyl alcohol (PVOH) package but with a delayed opening which can be tuned as desired. In particular, the opening delay can be tuned such that one package can be caused to open after another related package, such that the timed release of different compositions can be achieved within a wash cycle. The delayed opening can be achieved within a single package having multiple compartments, even though the package is formed from the same PVOH material.

[0003] Detergent compositions for use in automatic dishwashing cycles are well known in the art. Water-soluble polymeric films are commonly used as packaging materials for these to simplify dispersing, pouring, dissolving and dosing. A consumer can directly add the package or pouch to a dishwashing machine. Advantageously, this provides for accurate dosing while eliminating the need for the consumer to measure the composition. The package may also reduce mess that would be associated with dispensing a similar composition from a vessel, such as pouring a liquid laundry detergent from a bottle. The package also insulates the composition therein from contact with the user's hands. In sum, soluble polymeric film packages containing pre-measured agents provide for convenience of consumer use in a variety of applications.

[0004] It is also known that the timing of the release of these detergents can be key to achieving optimum performance. For example, it may be desirable to ensure that the water in the dishwasher has reached an optimum temperature before it is released. Alternatively, when there are several different detergent compositions, it may be desirable for them to be released in a particular order or with a particular spacing.

[0005] To achieve the delayed release of actives in a wash cycle, a water-soluble film package may be slow dissolving and remain substantially intact for the 15-20 minutes at nominally 40° C. Some water-soluble polymeric films that are used to make packages will incompletely dissolve during such a wash cycle, leaving film residue on items within the wash, or will dissolve prematurely resulting in a decreased efficacy of certain laundry additives (e.g., enzymes) that may become unstable in the presence of other active agents. Attempts for delayed release properties can be separated as being either machine-, device-, or detergent-driven. A machine or device can separately deliver the actives at predetermined timepoints of the wash cycle, ideally without overlap ('sequential dosing'). However, a detergent can usually only provide a delay in the release of one active versus another ('delayed dosing') through the inherent solubility of the ingredient. More precisely, the latter can be adjusted via a variety of pathways, such as specifically designed coating materials (employing hydrophilicity / hydrophobicity and solubility as design principles), tailored host matrices (relying on slow release kinetics), complex optimized packaging materials (with spatially isolated areas of lower or higher solubility), nested product design choices ('pouch-in-pouch'), variations of particle size distributions, and delivery formats (e.g., the effect of a powder vs a hard-pressed tablet on the accessible product surface area), and others.

[0006] PVOH is a commonly used film for making detergent packages. It is water-soluble, forms an attractive film and is cost-effective. Water-soluble polymeric films based on PVOH can however be subject to changes in solubility characteristics. The acetate group in the co- poly(vinyl acetate vinyl alcohol) polymer is known by those skilled in the art to be hydrolysable by either acid or alkaline hydrolysis. This is an inherent weakness in the application of films based on just the vinyl acetate / alcohol co-polymer typified by commercial PVOH resins. In the presence of a strong base such as a laundry bleaching additive, PVOH resins with pendant carboxyl groups, such as vinyl alcohol / hydrolysed methyl acrylate sodium salt resins, will deteriorate over the course of several weeks, at relatively warm (ambient) and high humidity conditions. Consequently, as they age, the packets may become increasingly prone to premature dissolution during a hot wash cycle (nominally 40° C.) and may in turn decrease the efficacy of certain actives due to the presence of the bleaching agent.

[0007] The current state of the art in water-soluble / reactive / dispersible packages for delivering bleach with a delayed release relative to a dishwashing detergent includes the use of a multi-compartment water-soluble pouch made from polyvinyl alcohol (PVOH) film, wherein the second pouch, containing a solid, dissolves slower than the first, as is described in U.S. Pat. No. 6,727,215, and U.S. Patent Publication Nos. 2009 / 0011970 and 2010 / 0192086. There remains a need for packages comprising water-soluble films having the desired characteristics of delayed release in hot water, sufficient solubility so as not to leave any film residue on the wash load once the wash cycle is complete, chemical and physical compatibility with a dishwashing detergent, and mechanical properties including good processability.

[0008] It is an object of the present invention to provide an improved or at least alternative approach for delayed release of automatic dishwashing detergent ingredients, or at least to tackle problems associated therewith in the prior art or to provide a commercially viable alternative thereto. It is particularly an aim to provide a route for providing a delayed release from a specific compartment of a PVOH-based monodose ADW detergent pouch without critically affecting its aesthetic profile or properties. By “monodose”, it is meant that the product comprises one or more compositions in the quantity required for a single wash cycle of a machine dishwasher.

[0009] Trisodium citrate is known in some automatic dishwashing compositions for use as a builder. W02008 / 087414 concerns dosage elements for a ware washing machine and a method of manufacturing such dosage elements. This has examples, such as Examples 3 and 4, which contain trisodium citrate. W02008 / 087417 has a similar disclosure.

[0010] WO2018 / 033526 discloses a composition for use in a machine washer.

[0011] WO2022 / 253814 relates to a water-soluble film comprising more than one polyvinyl alcohol resin and at least one plasticiser present in an amount of at least 20% by weight of the film, wherein at least one polyvinyl alcohol resin has a weight average molecular weight of at least 50,000 g / mol, and at least one polyvinyl alcohol resin has a weight average molecular weight of less than 50,000 g / mol.

[0012] US2014 / 0110301 discloses a water-soluble film useful in unit-dose chemical packaging. The film may include: a water-soluble saccharide and a polyvinyl alcohol copolymer consisting essentially of: (a) from 80 to 99 mole percent of vinyl alcohol and vinyl ester monomer; and (b) from 1 to 20 mole percent of a pyrrolidone comonomer. WO2021 / 067482 discloses water-soluble films and / or water-soluble unit dose articles comprising a water-soluble mixture comprising a polyvinyl alcohol (PVOH) and a polyvinylpyrrolidone (PVR), and methods of making and using the same.

[0013] US2016 / 0024446 discloses water-soluble films, including polyvinyl alcohol (PVOH) and an acrylate resin (e.g., methyl acrylate), wherein the water-soluble film remains intact for at least 3 minutes when submerged in water heated to a temperature of about 40° C.

[0014] According to a first aspect there is provided a water-soluble polyvinyl alcohol (PVOH) package comprising at least a first compartment and a second compartment separated from the first compartment, the first compartment containing a first automatic dishwashing detergent composition for release during a dishwashing cycle, wherein the first automatic dishwashing detergent composition is a water-free liquid, gel or suspension, and wherein the first automatic dishwashing detergent composition comprises a polycarboxylic acid or polyaldehyde solubilised in a polar organic solvent in a weight ratio of polar organic solvent to polycarboxylic acid or polyaldehyde of at least 1 :1.

[0015] The present disclosure will now be described further. In the following passages different aspects / embodiments of the disclosure are defined in more detail. Each aspect / embodiment so defined may be combined with any other aspect / embodiment or aspects / embodiments unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous. It is intended that the features disclosed in relation to the product may be combined with those disclosed in relation to the method and vice versa.

[0016] As discussed below, the inventors have surprisingly found that the introduction of small quantities of a crosslinking agent, such as citric acid in a soluble form, into a compartment of an ADW detergent pouch produced a modification of the PVOH film’s properties - for example resulting in a delayed compartment opening and dissolution time and consequently slower release of ingredients from within the compartment. This gives rise to a particular advantage for multi-compartment ADW detergent pouches, where the dissolution of different compartments can be independently adjusted. Advantageously, the method described herein for crosslinking employs established detergent ingredients, allows control of the degree of crosslinking, does not result in concomitant formation of insoluble residues of PVOH, and is suitable for simple liquid surfactant-based formulations.

[0017] Advantageously, the invention provides a flexible adjustment of the properties of water- soluble films which can be used to meet different regulatory requirements e.g., to comply with the safety mandate in Turkey requiring a certain minimum time until the release of ingredients. This can be achieved using the invention without testing and qualifying new or different PVOH films. In addition, challenges such as the consumer safety issue resulting from splashing of liquid-containing compartments may be mitigated by selectively modifying the physical properties of the PVOH film through crosslinking.

[0018] In making the invention, the inventors were performing trials investigating eutectic solvents. As part of this they were providing citric acid in a concentrated and non-aqueous form in a water-soluble polyvinyl alcohol (PVOH) package containing an automatic dishwashing detergent composition. They found that this led to an undesirable associated crosslinking effect of polyvinyl alcohol.

[0019] The inventors then realised that this undesirable effect could instead to be controlled, rendering this effect a desirable feature. Through the use of a liquid, non-aqueous form of citric acid, supplied via a solution in a solvent and introduced into the water-soluble pouch in a carefully controlled manner, it was possible to adjust the degree of crosslinking of the film. This effective post-manufacturing modification of the film was demonstrated to modify the solubility profile of the PVOH, thus allowing the delayed release of the compartments' content to the wash liquor.

[0020] The inventors have demonstrated in the examples below that a noticeable effect - the delayed release of formula from a specific compartment - can be realized in a monodose format by employing a soluble form of acid or aldehyde to (weakly) crosslink a selected PVOH compartment from the inside out. This is particularly demonstrated in the examples provided below with the inclusion of citric acid.

[0021] While the inventors have demonstrated that the delayed release can be achieved with a wide range of solvents, the work was pursued further with a focus placed on identifying the most suitable solvents for this purpose. This was because, for example a storage stability study of ethyl lactate revealed a strong interaction with the film which means it is not suitable for all applications. It was subsequently found that certain solvents (ideally polar, but nonplasticizing solvents such as PEG 200 (or DPG)) are more suitable alternatives.

[0022] The invention will now be discussed in more detail below.

[0023] The present invention relates to a water-soluble polyvinyl alcohol (PVOH) package comprising at least a first compartment and a second compartment separated from the first compartment, the first compartment containing a first automatic dishwashing detergent composition for release during a dishwashing cycle. PVOH packages are well known in the art and suitable products sold within such packages (also known as “pouches”) are, for example, sold as Finish Powerball.

[0024] Currently, polyvinyl alcohol (PVOH) is still the most commonly used water-soluble detergent package film material. Certain grade PVOH has a good dissolution and biodegradation profile, and is recognized as cold water-soluble and readily biodegradable. The package is water-soluble in that it at least partially dissolves or disperses in water at 20 °C within 10 minutes to allow for egress of the contents of the package into the surrounding water. Preferably the package will fully dissolve within a normal dishwasher washing cycle.

[0025] The package comprises a polyvinyl alcohol (PVOH) film. PVOH is a synthetic, water-soluble polymer that is biodegradable. PVOH is slightly soluble in ethanol, but insoluble in other organic solvents.

[0026] PVOH is commonly produced from the hydrolysis of polyvinyl acetate (PVA) in the presence of methanol and a catalyst (for example, sodium hydroxide). The properties of the polymer can be affected by the degree to which the polyvinyl acetate has been hydrolysed. For example, the higher the degree of hydrolysis, the more water-soluble the PVOH. As a result of the hydrolysis method using polyvinyl acetate, the PVOH may comprise some acetate groups. The presence of these acetate groups does not affect the properties of the PVOH. Consequently, the term PVOH as used herein encompasses films containing vinyl acetate groups in addition to vinyl alcohol groups. Preferably the film comprises less than 15 mol% acetate groups, preferably less than 10 mol% acetate groups, more preferably less than 8 mol% acetate groups. The degree of hydrolysis is known to influence the temperature at which the PVOH starts to dissolve in water. A degree of hydrolysis of 88% corresponds to a film soluble in cold (i.e. room temperature of 20°C) water, whereas a degree of hydrolysis of 92% corresponds to a film soluble in warm water. The film may be cast, blown or extruded. It may further be unoriented, mono-axially oriented or bi-axially oriented.

[0027] The water-soluble film may further comprise at least one plasticizer, preferably glycerin. It is commonly known that an increase of the plasticizer content to an amount of 20-35% by weight of the film improves the forming properties of the film. This is thought to be due to the plasticizer decreasing the glass transition temperature and therefore providing flexibility to the film.

[0028] The water-soluble film may further comprise one or more processing aids. Suitable processing aids include mono-, di-, tri-carboxylic acids I salts thereof, fatty acids such as stearic acid I salts thereof, mono-, di- or triglycerides I salts thereof, fumed silica, and inorganic and organic pigments. An anti-blocking agent may also be present in the film. Suitable anti-blocking agents include silica, talcum, zeolites, and starch.

[0029] The first automatic dishwashing detergent composition is a water-free liquid, gel or suspension. The exact nature of the composition is not critical, but it is necessary that the polycarboxylic acid or polyaldehyde is able to contact the PVOH wall of the package after it has been formed; therefore, the composition cannot be a solid. The provision of a gel permits some contact of the composition across the membrane, but this is most preferably achieved with a liquid or suspension, whereby the crosslinking can be most readily achieved by circulation of the reagents against the PVOH membrane. By “water-free” it is meant that the composition comprises at most 2 wt% water, more preferably at most 1 wt%, still more preferably at most 0.5 wt%, and most preferably no or substantially no water. Preferably, the composition comprises no water other than that which may form trace impurities of the components of the composition.

[0030] The first automatic dishwashing detergent composition comprises a polycarboxylic acid or polyaldehyde. By having multiple functional groups it is possible for the reagent to achieve the additional crosslinking of the PVOH on which the invention depends. When the composition comprises a polycarboxylic acid, the polycarboxylic acid comprises from 2 to 5 carboxylic acid groups. More preferably it is a di- or tri-carboxylic acid. Preferably the polycarboxylic acid is one or more selected from the group consisting of citric acid, maleic acid, fumaric acid, malic acid, sulfosuccinic acid, tartaric acid, tartronic acid, adipic acid, succinic acid, phthalic acid, iso-phthalic acid, terephthalic acid, aconitic acid, malonic acid, oxydisuccinic acids, 1 , 1 , 2, 2-ethane tetracarboxylic acids, 1 ,1 ,3,3-propane tetracarboxylic acids, 1 ,1 ,2,3-propane tetracarboxylic acids, and polyacrylic acid. Most preferably, the polycarboxylic acid is citric acid. Preferably the polycarboxylic acid is in the form of the free acid and is not in the form of a salt.

[0031] When the composition comprises a polyaldehyde, preferably the polyaldehyde comprises from 2 to 5 aldehyde groups. More preferably it is a di- or tri-aldehyde. Preferably the polyaldehyde is selected from the group consisting of glyoxal, glutaraldehyde and a combination thereof.

[0032] It should be appreciated that this requirement for a polycarboxylic acid or polyaldehyde excludes the polymerisation product of such a component, such that there must remain multiple functional moieties. Preferably the polycarboxylic acid or polyaldehyde has a molecular weight of less than 500g / mol, preferably less than 300g / mol and most preferably from 50 to 200g / mol.

[0033] The polycarboxylic acid or polyaldehyde is solubilised in a polar organic solvent. That is, the polycarboxylic acid or polyaldehyde is fully dissolved and there is no presence of solid or suspended polycarboxylic acid or polyaldehyde present in the solvent. This must be the case at least at room temperature (20 °C) and ideally under colder storage temperatures such as down to 10 °C. An ability to ensure full solubility at lower temperatures is desirable to ensure product stability.

[0034] There is a weight ratio of polar organic solvent to polycarboxylic acid or polyaldehyde of at least 1 :1. This parameter helps to ensure that the polycarboxylic acid or polyaldehyde is fully solubilised in a polar organic solvent. That is, unless there is an equal amount or an excess of the solvent, it is unlikely that the polycarboxylic acid or polyaldehyde will dissolve. Furthermore, without an equal amount or an excess amount of the solvent it is harder to ensure an even distribution of the polycarboxylic acid or polyaldehyde within the package. Preferably the weight ratio of polar organic solvent to polycarboxylic acid or polyaldehyde is at least 2:1 , preferably at least 6:1 and more preferably at least 10:1 . Preferred ranges extend from 1 :1 to 20: 1 , more preferably 10:1 to 15:1.

[0035] Preferably the polycarboxylic acid or polyaldehyde is present in an amount of at most 16 wt% of the first automatic dishwashing detergent composition, more preferably at most 8 wt% and more preferably at most 4 wt%. Most preferred ranges are from 0.1 to 3 wt%, still more preferably from 0.5 to 2 wt%. These amounts are sufficient to achieve a sufficient extension in the release time, without otherwise adversely affecting the composition and dosing of the active ingredients.

[0036] As noted above, the polar organic solvent is capable of dissolving the polycarboxylic acid or polyaldehyde. Preferably the polar organic solvent is one or more selected from the group consisting of polyols and sugar alcohols. Preferably the polar organic solvent is one or more selected from the group consisting of N-acetylcaprolactam, propylenecarbonate, y- valerolactone, cyrene, acetonitrile, E-caprolactone, E-caprolactam, dimethylsulfoxide, ethylene carbonate, 8-butyrolactone, y-butyrolactone, N-methylpyrrolidone, methyl sulfolane, sulfolane, 2,3-butylene carbonate, nitromethane, 2-pyrrolidone, butadiene sulfone, cyclobutanone, cyclopentanone, ethylene sulfite, glycerol carbonate acetate, N-acetyl piperidine, N-acetyl pyrrolidone, 1 -butanol, 2-butanol, 1 -propanol, 2-propanol, ethanol, ethylene glycol monomethyl ether, methyl carbitol, methyl cellosolve, tetrahydrofurfuryl alcohol, n-amyl alcohol, polyethylene glycol, and dipropylene glycol. Most preferably the polar organic solvent comprises polyethylene glycol and / or dipropylene glycol

[0037] Preferably the polar organic solvent is selected from the group consisting of dipropylene glycol and polyethylene glycols having a weight average molecular weight (Mw) of at least 150. More preferably, the weight average molecular weight (Mw) is at least 200, preferably at least 300 and more preferably at least 400.

[0038] Preferably the polar organic solvent is present in an amount of from 1 to 40 wt% of the first automatic dishwashing detergent composition, preferably from 10 to 30 wt%. Preferably the polar organic solvent is present in an amount of from 15 to 25 wt% of the first automatic dishwashing detergent composition, preferably from 18 to 22 wt%. Preferably the polar organic solvent does not plasticise the PVOH package. By “does not plasticise” it is meant that there is at most a negligible plasticisation effect which does not have an effect on the function of the package. Solvents can be readily tested against the PVOH package film to determine whether or not they meet this requirement.

[0039] Preferably the first automatic dishwashing detergent composition comprises a surfactant in an amount of at least 20 wt% of the composition. Preferably the surfactant is one or more non-ionic surfactants, more preferably one or more fatty alcohol alkoxylate surfactants. Preferably, the surfactant is two or more fatty alcohol alkoxylate surfactants. Suitable surfactants for use as detergents are well known in the art and there are no particular limitations on the nature of the surfactants which can be employed with this invention.

[0040] Preferably the first automatic dishwashing detergent composition comprises one or more active ingredients selected from the group consisting of builders, bleaching agents, bleach activators, bleach catalysts, surfactants, enzymes, anti-corrosion agents, polymers and foam control agents. Suitable examples of such components are disclosed in WO 2020 / 152044, the contents of which are incorporated herein by reference.

[0041] The water-soluble PVOH package further comprises a second compartment, preferably containing a second automatic dishwashing detergent composition. In some embodiments the second compartment does not employ the benefits of the invention, such that it is not delayed from release and the first compartment will therefore be configured to open later than the second compartment.

[0042] Preferably the second compartment also employs the benefits of the invention. That is, preferably the second automatic dishwashing detergent composition is a water-free liquid, gel or suspension, and further comprises a polycarboxylic acid / polyaldehyde solubilised in a polar organic solvent. Preferably the polycarboxylic acid / polyaldehyde will be different in the second compartment than the first compartment. This difference may be the identity of the polycarboxylic acid / polyaldehyde, the type of reagent (i.e. one is a polycarboxylic acid and the other a polyaldehyde), or the concentration (i.e. first concentration of polycarboxylic acid / aldehyde in the first automatic dishwashing detergent composition is different from a second concentration of polycarboxylic acid / polyaldehyde in the second automatic dishwashing detergent composition). Preferably the first concentration is at least 25% greater than the second concentration, more preferably at least 50% greater and most preferably at least 100% greater.

[0043] In some embodiments, the water-soluble PVOH package further comprises third and optionally fourth compartments comprising third and optionally fourth automatic dishwashing detergent compositions respectively. Each of the compartments is separated from one another. Any or all of the optional compositions may employ the benefits of the invention. Preferably, the or each automatic dishwashing detergent composition comprises one or more active ingredients as set out above.

[0044] According to a further aspect there is provided a method for the manufacture of a water- soluble polyvinyl alcohol (PVOH) package, the method comprising: i) providing a composition in the form of a water-free liquid, gel or suspension comprising one or more ADW active ingredients; ii) dissolving a polycarboxylic acid or polyaldehyde in a polar organic solvent to form a crosslinking component; iii) mixing the crosslinking component with the composition to form a first automatic dishwashing detergent composition; and iv) filling the first automatic dishwashing detergent composition into a first compartment of a water-soluble polyvinyl alcohol (PVOH) package comprising a first compartment and a second compartment separated from the first compartment.

[0045] Preferably the method further comprises filling a second automatic dishwashing detergent composition into the second compartment.

[0046] An example of filling the first compartment is described below:

[0047] A first water-soluble PVOH film was placed on a Wektor thermoforming kit with a mould having at least one individual cavity. Preferred are two, and especially preferred three, or four, individual cavities. Heat and vacuum were applied to the first water-soluble film to assist forming into the cavities.

[0048] The heat and the vacuum have been applied in order to deform the first water-soluble film in such a way that the individual cavities are foreseen to generate the respective number of compartments for the final water-soluble container. Afterwards the at least one compartment generated by the at least one cavity is at least partially filled with an automatic dishwashing detergent composition.

[0049] Afterwards, a second water-soluble film is placed on top of the first water-soluble PVOH film to close the at least one compartment. Therefore, heat is applied to seal the two water- soluble films to finally generate the water-soluble container, which is at least partially filled with a dishwashing, preferably an automatic dishwashing, detergent composition as a monodose article.

[0050] Preferably the method is for the manufacture of the water-soluble PVOH package described herein. Accordingly, all features of the first aspect may be freely combined with this method. In embodiments in which the PVOH package comprises third and optionally fourth compartments, the method preferably further comprises filling a third and optionally fourth automatic dishwashing detergent composition into the respective compartments.

[0051] According to a further aspect there is provided a water-soluble polyvinyl alcohol (PVOH) package obtained or obtainable by the method described herein.

[0052] According to a further aspect there is provided a method of operating an automatic dishwasher, the method comprising introducing the water-soluble polyvinyl alcohol (PVOH) package as described herein into the dishwasher before or during a washing cycle.

[0053] According to a further aspect there is provided the use of a solubilised polycarboxylic acid or polyaldehyde in a polar organic solvent, dispersed within an automatic dishwashing detergent composition to delay the dissolution or opening of a retaining PVOH membrane.

[0054] The invention will now be described further in relation to the following non-limiting examples. Compositions based on Ethyl Lactate and Citric Acid

[0055] Initially, a series of experiments was set up (outlined in Table 1) to explore the degree of PVOH crosslinking, measured by their respective dissolution time, and correlated to the content of citric acid in surfactant.

[0056] Exemplary Procedure: To prepare mixture V002, citric acid (1.87g) and ethyl lactate (73.1g) were combined in a glass beaker and heated to 150°C and left to cool to room temperature. This mixture was then added to Genapol EP 2584 (25g), a non-ionic fatty alcohol alkoxylate surfactant, and stirred until the components were mixed homogenously to produce V002. The compositions V003-V006 were prepared following a similar procedure; however, with the corresponding quantities of citric acid and ethyl lactate adjusted as outlined in Table 1.

[0057] Of the resulting compositions, 0.5 mL were dosed into the Powerball (PB) compartment of PVOH pouches and placed in the denoted storage stability conditions (40°C I 75%r.h., 3 and 6 weeks).

[0058] Stability Assessment: To observe and determine the degree of PVOH crosslinking, the dissolution times and visual changes were recorded after 3 and 6 weeks at 40°C 175%r.h. For the visual assessment (Table 2), the pouches are compared to a benchmark (BM); where the powder is white with no yellow discolorations and no yellow / darker / brownish particles; the gel with separation (in line with BM) with no bubbles, no leaking; the PB liquid clear, red with no leaking, and the PVOH should be transparent, soft and with no wrinkling.

[0059] Table 2: Visual assessment of samples after 3 and 6 weeks at 40°C / 75%r.h. including scoring. Scoring system: 5 = no changes vs benchmark and accepted aesthetic at time; 4 = some compartments present very little changes; 3 = one or two compartments present changes in acceptable range; 2 = almost all the compartments present significant differences; 1 = failure, very strong, unacceptable changes.

[0060] For the dissolution times, performed on the ERWEKA Zerfallszeittester at 40°C water temperature, the Powerball opening and its complete dissolution were recorded and are shown in Table 3.

[0061] Table 3: Mean dissolution times of samples after 3 and 6 weeks, 40°C / 75%r.h. at 40°C water temperature. Conclusion: In conclusion, there is a strong correlation between the citric acid (CA) content in the formula and the Powerball opening and dissolution times, respectively. However, for the next section of the study, a different, less plasticizing and less odorous solvent was chosen, as well as a lower inclusion level of the solvent (= higher active level of the surfactant).

[0062] Compositions Based on Other Polar Solvents and Citric Acid

[0063] Stemming from former experiences in formulation design and storage stability, the study was repeated, employing PEG 200, a known, more PVOH-compatible solvent.

[0064] Exemplary Procedure: To prepare mixture V007, citric acid (0.63 g) was dissolved in PEG 200 (24.4 g) in a glass beaker. This mixture was then added to Genapol EP 2584 (75 g), a non-ionic fatty alcohol alkoxylate surfactant, and stirred until the components were mixed homogenously to produce V007. The compositions V007-V009 were prepared following the same procedure; however, with the quantities of citric acid and PEG 200 adjusted as outlined in Table 4.

[0065] Of the resulting compositions, 0.5 mL were dosed into the PB compartment of PVOH pouches and placed in the denoted storage stability conditions (40°C 175%r.h., 3 and 6 weeks).

[0066] PB compositionv007 v008 v00g

[0067] [g] [8] [g]

[0068] Genapol EP 2584 75.0 75.0 75.0

[0069] PEG-200 24.4 23.8 23.1

[0070] Citric Acid 0.63 1.25 1.88

[0071] Table 4: Composition of mixtures in PVOH Powerballs for storage stability.

[0072] Stability Assessment: To observe and determine the degree of PVOH crosslinking and suitability of solvent, the dissolution times and visual changes were recorded after 3 and 6 weeks at 40°C / 75%r.h. The results in Table 5 demonstrate little to no changes in the PVOH aesthetic after 3 and 6 weeks as the PB liquid remains clear and red with no observable softening / wrinkling of the PVOH film. Table 5: Visual assessment of samples after 3 and 6 weeks at 40°C / 75%r.h. including scoring. Scoring system: 5 = no changes vs benchmark and accepted aesthetic at time; 4 = some compartment presents very little changes; 3 = one or two compartments presents changes in acceptable range; 2 = almost all the compartment present significant differences;

[0073] 1 = failure, very strong, unacceptable changes.

[0074] For the dissolution times, performed on the ERWEKA Zerfallszeittester at 40°C water temperature, the PB opening and its complete dissolution were recorded (Table 6).

[0075] Table 6: Mean dissolution times of samples from CI_S013_22 after 3 and 6 weeks at 5°C, 50%r.h. and 40°C, 75%r.h., respectively. Dissolution conditions: Erweka machine with a water bath temperature of 40°C.

[0076] In summary, the results in Table 6 demonstrate a correlation between the 'Powerball opening' time and the 'Complete dissolution' time of the PB compartment after 3 weeks and 6 weeks of storage, at both 5°C and 40°C. In addition, and reassuringly, the recorded times do not substantially increase between 3 to 6 weeks.

[0077] Conclusion

[0078] The Examples demonstrate that an inside-out crosslinking of water-soluble polyvinyl alcohol films can be achieved through the controlled delivery of a crosslinking agent - for example, di-, tri-, or other oligocarboxylic acids - into the respective compartment. Crucially, this limited and controlled degree of crosslinking does not noticeably affect the technical or aesthetic properties of the film, and it does not result in the formation of insoluble residue.

[0079] All percentages are by weight unless otherwise specified.

[0080] The foregoing detailed description has been provided by way of explanation and illustration and is not intended to limit the scope of the appended claims. Many variations in the presently preferred embodiments illustrated herein will be apparent to one of ordinary skill in the art and remain within the scope of the appended claims and their equivalents.

[0081] For the avoidance of doubt, the entire contents of all documents acknowledged herein are incorporated herein by reference.

Claims

Claims:

1. A water-soluble polyvinyl alcohol (PVOH) package comprising at least a first compartment and a second compartment separated from the first compartment, the first compartment containing a first automatic dishwashing detergent composition for release during a dishwashing cycle, wherein the first automatic dishwashing detergent composition is a water-free liquid, gel or suspension, and wherein the first automatic dishwashing detergent composition comprises a polycarboxylic acid or polyaldehyde solubilised in a polar organic solvent in a weight ratio of polar organic solvent to polycarboxylic acid or polyaldehyde of at least 1 :1.

2. The water-soluble PVOH package according to claim 1 , wherein the polycarboxylic acid is a di- or tri-carboxylic acid or wherein the polyaldehyde is a di- or tri-aldehyde.

3. The water-soluble PVOH package according to claim 1 or claim 2, wherein the polycarboxylic acid is one or more selected from the group consisting of citric acid, maleic acid, fumaric acid, malic acid, sulfosuccinic acid, tartaric acid, tartronic acid, adipic acid, succinic acid, phthalic acid, iso-phthalic acid, terephthalic acid, aconitic acid, malonic acid, oxydisuccinic acids, 1 ,1 ,2,2-ethane tetracarboxylic acids, 1 ,1 ,3,3-propane tetracarboxylic acids, 1 ,1 ,2,3-propane tetracarboxylic acids, and polyacrylic acid.

4. The water-soluble PVOH package according to any preceding claim, wherein the polyaldehyde is selected from the group consisting of glyoxal, glutaraldehyde and a combination thereof.

5. The water-soluble PVOH package according to any preceding claim, wherein the polycarboxylic acid or polyaldehyde is present in an amount of at most 16 wt% of the first automatic dishwashing detergent composition, preferably from 0.1 to 3 wt%, still more preferably from 0.5 to 2 wt%.

6. The water-soluble PVOH package according to any preceding claim, wherein the polar organic solvent is capable of dissolving the polycarboxylic acid or polyaldehyde at room temperature.

7. The water-soluble PVOH package according to any preceding claim, wherein the polar organic solvent is one or more selected from the group consisting of polyols, and sugar alcohols.

8. The water-soluble PVOH package according to any preceding claim, wherein the polar organic solvent is one or more selected from the group consisting of N- acetylcaprolactam, propylenecarbonate, y-valerolactone, cyrene, acetonitrile, E- caprolactone, E-caprolactam, dimethylsulfoxide, ethylene carbonate, 8-butyrolactone, y- butyrolactone, N-methylpyrrolidone, methyl sulfolane, sulfolane, 2,3-butylene carbonate, nitromethane, 2-pyrrolidone, butadiene sulfone, cyclobutanone, cyclopentanone, ethylene sulfite, glycerol carbonate acetate, N-acetyl piperidine, N-acetyl pyrrolidone, 1 -butanol, 2- butanol, 1 -propanol, 2-propanol, ethanol, ethylene glycol monomethyl ether, methyl carbitol, methyl cellosolve, tetrahydrofurfuryl alcohol, n-amyl alcohol, polyethylene glycol, and dipropylene glycol.

9. The water-soluble PVOH package according to any preceding claim, wherein the polar organic solvent is selected from the group consisting of dipropylene glycol and polyethylene glycols having a weight average molecular weight (Mw) of at least 150.

10. The water-soluble PVOH package according to any preceding claim, wherein the polar organic solvent is present in an amount of from 1 to 40 wt% of the first automatic dishwashing detergent composition, preferably from 10 to 30 wt%.11 . The water-soluble PVOH package according to any preceding claim, wherein the first automatic dishwashing detergent composition comprises a surfactant in an amount of at least 20 wt% of the composition, preferably wherein the surfactant is one or more non-ionic surfactants, more preferably one or more fatty alcohol alkoxylate surfactants.

12. The water-soluble PVOH package according to any preceding claim, wherein the second compartment contains a second automatic dishwashing detergent composition.

13. A method for the manufacture of a water-soluble polyvinyl alcohol (PVOH) package, the method comprising:i) providing a composition in the form of a water-free liquid, gel or suspension comprising one or more ADW active ingredients; ii) dissolving a polycarboxylic acid or polyaldehyde in a polar organic solvent to form a crosslinking component; iii) mixing the crosslinking component with the composition to form a first automatic dishwashing detergent composition; and iv) filling the first automatic dishwashing detergent composition into a first compartment of a water-soluble polyvinyl alcohol (PVOH) package comprising a first compartment and a second compartment separated from the first compartment.

14. A water-soluble polyvinyl alcohol (PVOH) package obtained or obtainable by the method of claim 13.

15. Use of a solubilised polycarboxylic acid or polyaldehyde in a polar organic solvent, dispersed within an automatic dishwashing detergent composition to delay the dissolution or opening of a retaining PVOH membrane.

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