Water-soluble package containing an automatic dishwashing detergent composition

Abstract

The invention relates to a water-soluble package containing an automatic dishwashing detergent composition for release during a dishwashing cycle, the package comprising a polyvinyl alcohol (PVOH) film, wherein the film is substantially free from glycerol and 1,2-propylene glycol, and wherein the film comprises from 5 to 30 wt%, based on the total weight of the film, of one or more non-ionic alcohol alkoxylates having a C8 to C20 alkyl group alkoxylated with from 1 to 15 alkoxylate units, wherein the alkoxylate units are ethoxylate units or a mix of ethoxylate and propoxylate units. The invention further relates to a method for preparing a water-soluble package containing an automatic dishwashing detergent composition for release during a dishwashing cycle, the package comprising a polyvinyl alcohol (PVOH) film, wherein the film is substantially free from glycerol and 1,2-propylene glycol, and wherein the film comprises from 5 to 30 wt%, based on the total weight of the film, of one or more non-ionic alcohol alkoxylates having a C8 to C20 alkyl group alkoxylated with from 1 to 15 alkoxylate units, wherein the alkoxylate units are ethoxylate units or a mix of ethoxylate and propoxylate units.

Description

[0001] Water-soluble package containing an automatic dishwashing detergent composition

[0002] The present invention relates to an improved water-soluble package containing an automatic dishwashing (ADW) detergent composition. In particular, the present invention provides innovative formulas of polyvinyl alcohol (PVOH) which avoid the need for conventional plasticizers, e.g. glycerol. The invention has the benefit of reducing the amount of non-functional materials in the overall product when the films are used to wrap ADW detergent compositions.

[0003] It is well known that certain home laundry products need to be provided in a consumer-safe packaging. This is the case whether or not the product is provided as a solid or as a liquid.

[0004] It has become common-place now for these products, especially pre-dosed liquid detergents, to be provided in PVOH-based packages. For dishwashing applications these packages are formed from PVOH film which is filled with the ADW detergent composition. In use, the PVOH dissolves to firstly release the detergent, but then more fully, so that no PVOH residue is left in the dishwasher.

[0005] Since the films used to wrap ADW detergent compositions are single-use plastics, there is an environmentally driven desire to make such a PVOH film for monodose products more sustainable. This can be achieved by using thinner films and, consequently, less material, but beyond a certain point the film stops having a desirable strength and fails to hold or protect the detergent composition.

[0006] WO21163965 discloses the use of cationic surfactant in PVOH formulas to make porous, soluble solid sheet articles with performance benefits. However, this application indicates that the PVOH formula needs a high amount of glycerol (22-40%). In addition, there is no indication that the described films can be cast, thermoformed and sealed to create pouches.

[0007] WO19048474 discloses washing- and cleaning-active polymer films comprising non-ionic surfactants (NIO). PVOH is contemplated in some embodiments, but the NIO is always loaded in a polyacrylic acid layer along with glycerol. In addition, there is no indication that the described films can be cast, thermoformed and sealed to create pouches. WO19007954 discloses a PVOH formula for 30-200 m thickness films comprising anionic surfactant, plasticizers and other ingredients. In this application, glycerol, PEG 600 and other ingredients are always needed. Moreover, such anionic surfactants are usually considered incompatible with the ADW process as they result in very stable foams. Similarly, U52020010784 discloses a PVOH based laundry sheet comprising an anionic surfactant, albeit with a thickness of from 5 mm to 0.5 cm.

[0008] WO12003367 discloses a PVOH film produced from compressed nonwoven web, which may contain anionic surfactants. This disclosure requires a complicated filament forming- spinning-compressing process.

[0009] It is an object of the present invention to provide a new method for improving PVOH water- soluble packaging for ADW detergent compositions, such as to improve sustainability and / or to reduce or avoid the need for conventional plasticizers such as glycerol, or at least to tackle problems associated therewith in the prior art, or to provide a commercially viable alternative thereto.

[0010] According to a first aspect there is provided a water-soluble package containing an automatic dishwashing detergent composition for release during a dishwashing cycle, the package comprising a polyvinyl alcohol (PVOH) film, wherein the film is substantially free from glycerol and 1 ,2-propylene glycol, and wherein the film comprises from 5 to 30 wt%, based on the total weight of the film, of one or more non-ionic alcohol alkoxylates having a C8to C2o alkyl group alkoxylated with from 1 to 15 alkoxylate units, wherein the alkoxylate units are ethoxylate units or a mix of ethoxylate and propoxylate units.

[0011] 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. The present inventors have realised that they can make their PVOH films more sustainable by reducing the amount of PVOH used, and simultaneously have the film act as a carrier for active ingredients such as non-ionic surfactants (NIO). NIO are widely used in laundry and automatic dishwasher (ADW) detergents. The inventors have realised that they can use certain non-ionic surfactants as a substitute for conventional plasticizer in PVOH formulas. This makes the PVOH film active and the formula more cost effective. It may also provide improved water solubility and tensile properties, with comparable thermoformability.

[0012] The inventors have realised that in conventional PVOH formulas, the amount of plasticizers, e.g. glycerol and propylene glycol (1 ,2-PG), can reach values of up to 25%. However, these plasticizer components do not bring any function to PVOHs apart from processibility. In the present invention, surfactants are utilized as new components in PVOH formulas to replace conventional plasticizers, and therefore they provide additional performance benefits and make the formula more cost effective.

[0013] The surfactants investigated in this invention are non-ionic alcohol alkoxylates comprising ethylene oxide (EO) units or a mix of EO and propylene oxide (PO) units. As shown in the Examples, PVOH formulas were designed and water-soluble PVOH sheets were prepared accordingly via the solution casting method using the film application device COATMASTER 510 Basic-G. Key parameters for monodose foil material were tested, including water solubility, tensile strength, sealing strength and thermoformability. It was found that:

[0014] 1) The loading of surfactants into the PVOH formula causes the water-soluble PVOH sheet article to become an active itself;

[0015] 2) The optimised formula contains only PVOH and NIO, and substantially no other conventional plasticizers;

[0016] 3) By controlling the thickness of the article, preferably in the range of 70 - 120 pm, one is able to produce optimised films to be used as a water-soluble detergent capsule material, thus providing a formulation with the technical benefits of having an active incorporated in the film with acceptable film properties.

[0017] The present invention relates to a water-soluble package containing an automatic dishwashing detergent composition for release during a dishwashing cycle. ADW detergents are well known in the art and the specific formulation is not critical to the functioning of the present invention. The package is intended to rupture in use, after a first portion of the package dissolves following contact with the washing medium.

[0018] 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.

[0019] 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 lower 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. That is, the term PVOH as used herein encompasses films containing vinyl acetate groups in addition to the vinyl alcohol groups. Preferably the PVOH comprises at most 15 mol% acetate groups, preferably less than 10 mol% acetate groups, more preferably at most 8 mol% acetate groups. In other words, the PVOH may comprise at least one vinyl acetate-vinyl alcohol copolymer, preferably wherein the vinyl acetate-vinyl alcohol copolymer comprises at least 85 mol% vinyl alcohol units, preferably at least 90 mol%, more preferably at least 92 mol%.

[0020] The degree of hydrolysis is known to influence the temperature at which the PVOH starts to dissolve in water. 88% hydrolysis corresponds to a film soluble in cold (i.e. room temperature of 20°C) water, whereas 92% hydrolysis 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.

[0021] The film is substantially free from glycerol and 1 ,2-propylene glycol. Preferably the film comprises less than 6 wt% total of glycerol and 1 ,2-propylene glycol, more preferably less than 2wt% and most preferably less than 0.5wt%. Preferably the film comprises less than 6 wt% total of any polyhydric alcohol, more preferably less than 2wt% and most preferably less than 0.5wt%. Preferably the film comprises less than 6 wt% total of any plasticizers (other than the NIO surfactant component, i.e. the non-ionic alcohol alkoxylate(s) as defined herein), more preferably less than 2wt% and most preferably less than 0.5wt%.

[0022] The film comprises from 5 to 30 wt%, based on the total weight of the film, of one or more non-ionic alcohol alkoxylates. Preferably the film comprises the one or more non-ionic alcohol alkoxylates in an amount of from 10 to 25 wt% based on the total weight of the film, more preferably from 15 to 25 wt%, still more preferably from 15 to 20 wt%. These ranges describe a product which has a meaningful amount of the non-ionic alcohol alkoxylates to achieve functional and plasticizing effects, without compromising the properties of the PVOH film (e.g. by making the film overly brittle).

[0023] The or each non-ionic alcohol alkoxylates has a C8to C2o alkyl group alkoxylated with from 1 to 15 alkoxylate units, wherein the alkoxylate units are ethoxylate units or a mix of ethoxylate and propoxylate units.

[0024] The or each non-ionic alcohol alkoxylate may be end-capped with an alkoxy group, for instance a Ci to Ci8alkoxy group. Preferably, however, the non-ionic alcohol alkoxylate is not end-capped i.e. it bears a terminal -OH group.

[0025] Preferably the PVOH and the one or more alcohol alkoxylates together form at least 75 wt% of the film, more preferably at least 85 wt%, still more preferably at least 95 wt%. Most preferably, the film consists essentially of or consists of the PVOH and the one or more alcohol alkoxylates.

[0026] Preferably for the or each non-ionic alcohol alkoxylate, a ratio of the number of alkoxylate units to the total number of carbon atoms in the C8to C2o alkyl group has a molecular weight (M2), wherein M M2is less than 1 .5. unit As shown in the Examples, an AO / C ratio of less than 1 .5 may result in softer films that are less stiff and brittle. In embodiments in which the non-ionic alcohol alkoxylate is not end-capped, the ratio AO / C is the ratio of the number of alkoxylate units to the total number of carbon atoms in the C8to C20alkyl

[0027] Preferably the alkoxylate units in the or each non-ionic alcohol alkoxylate are ethoxylate units. As shown in the Examples, ethoxylate units may be more compatible with PVOH grades commonly used to form PVOH pouches than propoxylate units.

[0028] Preferably the C8to C20alkyl group in the or each non-ionic alcohol alkoxylate is a C10 to C20alkyl group, preferably C10 to Ci8, more preferably Ci2to Ci6, and / or is optionally branched. Preferably the number average of alkoxylate units in the or each non-ionic alcohol alkoxylate is independently from 5 to 12, preferably from 6 to 11 , more preferably from 7 to 10.

[0029] Preferably the or each non-ionic alcohol alkoxylate is independently in accordance with formula (I) or formula (II):

[0030] Ri-[EO]m-[PO]n-OR2[formula (I)]

[0031] Ri-[PO]n-[EO]m-OR2[formula (II)] wherein:

[0032] Ri is C8to C20alkyl;

[0033] R2is H, or Ci to Ci8alkyl, preferably H;

[0034] EO is ethylene oxide;

[0035] PO is propylene oxide; m + n is from 1 to 15; and m 0.

[0036] The alkyl units for Ri and R2may be branched or unbranched.

[0037] In formula (I) and formula (II), preferably m > n. More preferably m > n+2. Most preferably, n = 0. As shown in the Examples, higher proportions of ethylene oxide units relative to propylene oxide units may improve compatibility with PVOH grades commonly used to form ADW pouches.

[0038] In formula (I) and formula (II), the ratio AO / C defined above is the ratio of m+n to the total number of carbon atoms present in Ri and R2.

[0039] Preferably the or each non-ionic alcohol alkoxylate has a hydrophilic-lipophilic balance (HLB) of from 10 to 15, preferably from 12 to 15, more preferably from 12 to 13, as determined by Griffin’s method.

[0040] According to a further aspect there is provided a method for preparing a water-soluble package containing an automatic dishwashing detergent composition for release during a dishwashing cycle, the package comprising a polyvinyl alcohol (PVOH) film, wherein the film is substantially free from glycerol and 1 ,2-propylene glycol, and wherein the film comprises from 5 to 30 wt%, based on the total weight of the film, of one or more non-ionic alcohol alkoxylates having a C8to C2o alkyl unit alkoxylated with from 1 to 15 alkoxylate units, wherein the alkoxylate units are ethoxylate units or a mix of ethoxylate and propoxylate units, the method comprising: i) providing a PVOH solution; ii) adding the one or more non-ionic alcohol alkoxylates to the PVOH solution to form a casting solution; iii) casting the solution to form a film; iv) drying the film; v) thermoforming the film to produce at least one pocket; vi) at least partially filling the or each pocket with an automatic dishwashing detergent composition; vii) placing a second film, prepared according to steps i) to iv), on top of the or each filled pocket; and viii) sealing the two films together.

[0041] As noted above, the films of the first aspect can be cast, thermoformed and sealed to create pouches. Any features described above in relation to the film in the first aspect are equally applicable to the film of the present aspect.

[0042] Preferably in step iv), the film has a dry thickness of from 70 to 120 pm.

[0043] According to a further aspect there is provided a water-soluble package obtained or obtainable by the method described herein.

[0044] According to a further aspect there is provided a method for operating an automatic dishwasher, the method comprising introducing the water-soluble package as described herein into the dishwasher before or during a dishwashing cycle.

[0045] Examples

[0046] The invention will now be illustrated further in relation to the following non-limiting examples: Example 1

[0047] Formulas and Film Preparation Method Innovative PVOH formulas comprising only PVOH and NIO were designed, the films thereof were prepared via the solution casting method and their properties were compared to understand the impact of NIO structure and amount in formulas for PVOH that does not contain conventional plasticizers (e.g. glycerol), and to suggest preferable formulas. Formula - Preferable NIO Type

[0048] 5 different formulas were designed, the films thereof were made, and their properties compared:

[0049] A, B) comparative formulas comprise conventional plasticizers, i.e. glycerol and 1 ,2- PG, respectively; 1 - 3) inventive formulas comprise no conventional plasticizers but only PVOH and

[0050] NIO, i.e., alcohol alkoxylates comprising EO and / or PO, respectively

[0051] Table 1. PVOH resin 1 , JP-05, has 87.0 - 89.0 mol% degree of hydrolysis (DH) with viscosity 4.0 - 6.0 mPa*s of 4 wt% aqueous solution at 20°C.

[0052] PVOH resin 2, JP-15, having 87.0 - 89.0 mol% degree of hydrolysis with viscosity 15.0 - 19.0 mPa*s of 4 wt% aqueous solution at 20°C. AO / C stands for the ratio of alkoxylates to carbon chain length from the alcohol part. Lutensol® AT 25, Lutensol® TO7 from BASF SE and Genapol® EP 2584 from Clariant were used as representatives for NIO AO / C > 1 .5, AO / C < 1 .5 with only EO and AO / C > 1 .5 with EO and PO, respectively. Formula - Preferable NIO Amount

[0053] 4 different formulas comprising different NIO amount were designed, the films thereof were made, and their properties compared:

[0054] Table 2. Lutensol® TO7 from BASF SE was used as a representative for NIO.

[0055] Formula - Preferable EO length (when carbon chain length remains constant)

[0056] 6 different formulas comprising AO / C >1.5 with constant carbon length and different EO length were designed, the films thereof were made, and their properties compared:

[0057] Table 3.

[0058] Lutensol® TO series, i.e., Lutensol® TO 2, 5, 7, 8, 12, and 20 from BASF SE were used as representatives to investigate the impact of EO length when carbon chain length remains constant.

[0059] Film Preparation Method

[0060] The preparation of films was carried out according to the following procedure:

[0061] 1) PVOH resins 1 and 2 were homogenized to a granule mixture according to their ratio in the formula. 20 wt% stock solution thereof was prepared by dissolving the mixture stepwise in water under stirring and heating at 60 °C;

[0062] 2) NIO (or plasticizer in the case of comparative formula) was weighted according to the formula respectively, and added into the stock solution, followed by stirring and heating at 60 °C to get a homogenous casting solution;

[0063] 3) The solution was then cast using a film application device COATMASTER 510 Basic-G and a thickness-adjustable film applicator. Wet film thickness was usually set to 300 - 1000 pm to achieve the dry thickness of 70 - 120 pm;

[0064] 4) The casted film was dried either at room temperature overnight, or in the oven at 50 - 60 °C for at least 3 hours.

[0065] Film Assessments and Methods

[0066] Films with a thickness of 90 pm were produced according to the aforementioned formulas and procedure; the following tests were carried out to evaluate the films as thermoforming foils for monodose products: i) frame dissolution; ii) film mechanical properties; iii) forming assessment.

[0067] 1) Frame Dissolution

[0068] Dissolution of films was tested according to the following method: A 1L beaker was filled with 800 mL of deionized water at around 20°C. Water was under stirring and the bottom of the vortex was at level with the 600 mL mark of the beaker. A film sample of 45 x 37 mm was placed in a frame and then immersed in the water, with cross section orthogonal to the direction of water flow. The timepoints when the first hole appeared and the whole film completely dissolved were recorded.

[0069] 2) Film Mechanical Properties

[0070] The tensile and sealing properties were tested according to ISO 527-3 and ASTM F88 on a Zwicki-Line testing machine Z1 .0.

[0071] 3) Forming assessment

[0072] Forming assessment of the films was tested according to the following method:

[0073] A water-soluble film was placed on a Wektor thermoforming kit with a mold having three individual cavities. Heat (130 °C) and vacuum (930 mbar) was applied to the film to assist forming into the cavities. A visual assessment was carried out for each individual cavity, wherein 0 = best forming behavior and 8 = worst forming behavior.

[0074] Results and Discussion

[0075] Preferable NIO Type

[0076] Films of formulas in table 1 were made, and their properties compared in the following table 4:

[0077] Table 4.

[0078] There is no data for films 1 and 3 since no representative film was successfully prepared accordingly. In the case of formula 1 , it was possible to prepare a homogenous casting solution. However, the dried films were heterogeneous, very stiff and brittle. It was difficult to obtain representative samples. In the case of formula 3, phase separation of the casting solution occurred spontaneously and quickly, therefore it was not possible to prepare a homogenous casting solution and films thereof. This might be the result of incompatibility between PVOH and NIO with a high amount of PO. However, it may be possible to use the non-ionic surfactants used in Films 1 and 3 with other grades of PVOH.

[0079] Compared to both comparative films, film 2 shows improved water solubility and tensile property, and comparable thermoformability. Although heat sealing of the film is weak, water sealing is still acceptable, which allows the inventive film 2 to be used as a water- soluble detergent capsule material.

[0080] It can be concluded from the data in table 4 that: i) It is possible to completely replace conventional plasticizer in a PVOH formula and produce a film, which is qualified as a foil for a monodose pouch; ii) NIO having AO / C < 1 .5 is preferable than NIO having AO / C > 1 .5 for a nonplasticizer PVOH formula; iii) NIO having AO / C < 1 .5 with only EO is preferable than NIO having AO / C > 1.5 with both EO and PO for a non-plasticizer PVOH formula.

[0081] Preferable NIO Amount

[0082] Films of formulas in table 2 were made, and their properties compared in the following table 5:

[0083] Table 5.

[0084] There is no data for film 4 since no representative film was successfully prepared accordingly. Too high amount of PVOH resins made the dried film very stiff and brittle. Dissolution properties of film 5, 2 and 6 do not differ much. Film 2 shows the best mechanical properties and thermoformability, followed by film 6.

[0085] It can be concluded from the data in table 5 that the preferable amount of NIO in a nonplasticizer PVOH formula is 10-25%, more preferable 15-25%, and most preferable 15- 20%.

[0086] Preferable EO length

[0087] Films of formulas in table 3 were made, and their properties compared in the following table 6: Table 6.

[0088] There is no data for film 11 since no representative film was successfully prepared accordingly. Similar to formula 1 it was possible to prepare a homogenous casting solution. However, the dried films were heterogeneous, very stiff and brittle.

[0089] Films 7, 2, 9 and 10 show similar dissolution behavior; film 8 is slightly inferior.

[0090] Film 8, 2 and 9 show better tensile property, water sealing and thermoformability than film 10, while film 7 is the least promising one.

[0091] It can be concluded from the data in table 6 that when the carbon chain length of NIO remains constant, the preferable EO length of NIO having AO / C < 1 .5 with only EO in a non- plasticizer PVOH formula is 5-12 (corresponding to a HLB value of 10-15 by Griffin's method), more preferable 7-12 (corresponding to HLB 12-15), and most preferable 7-8 (corresponding to HLB 12-13).

[0092] Conclusions

[0093] This invention proves the feasibility of a water-soluble PVOH sheet article without conventional plasticizers, and with alcohol ethoxylate which brings the PVOH additional performance benefits. This invention also suggests the preference regarding i) alcohol ethoxylate type, ii) amount, and iii) ethoxylate length.

[0094] All percentages are by weight unless otherwise specified. 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.

[0095] For the avoidance of doubt, the entire contents of all documents acknowledged herein are incorporated herein by reference.

Claims

Claims:1 . A water-soluble package containing an automatic dishwashing detergent composition for release during a dishwashing cycle, the package comprising a polyvinyl alcohol (PVOH) film, wherein the film is substantially free from glycerol and 1 ,2-propylene glycol, and wherein the film comprises from 5 to 30 wt%, based on the total weight of the film, of one or more non-ionic alcohol alkoxylates having a C8to C2o alkyl group alkoxylated with from 1 to 15 alkoxylate units, wherein the alkoxylate units are ethoxylate units or a mix of ethoxylate and propoxylate units.

2. The water-soluble package according to claim 1 , wherein the film comprises less than 6 wt% total of glycerol and 1 ,2-propylene glycol, preferably of any polyhydric alcohol, and preferably of any further plasticizers.

3. The water-soluble package according to claim 1 or claim 2, wherein the film comprises the one or more non-ionic alcohol alkoxylates in an amount of from 10 to 25 wt% based on the total weight of the film, more preferably from 15 to 25 wt%, still more preferably from 15 to 20 wt%.

4. The water-soluble package according to any preceding claim, wherein the film consists of the PVOH and the one or more alcohol alkoxylates.

5. The water-soluble package according to any preceding claim, wherein for the or each non-ionic alcohol alkoxylate, a ratio of the number of alkoxylate units to the total number of carbon atoms in the C8to C2o alkyl group and any end cap unit that may be present (AO / C) is less than 1 .5.

6. The water-soluble package according to any preceding claim, wherein the alkoxylate units in the or each non-ionic alcohol alkoxylate are ethoxylate units.

7. The water-soluble package according to any preceding claim, wherein the C8to C20alkyl group in the or each non-ionic alcohol alkoxylate is a C10 to C20alkyl group, preferably C10 to Ci8, more preferably Ci2to Ci6, and / or is optionally branched.

8. The water-soluble package according to any preceding claim, wherein the number average of alkoxylate units in the or each non-ionic alcohol alkoxylate is independently from 5 to 12, preferably from 6 to 11 , more preferably from 7 to 10.

9. The water-soluble package according to any preceding claim, wherein the or each non-ionic alcohol alkoxylate is independently in accordance with formula (I) or formula (II):Ri-[EO]m-[PO]n-OR2[formula (I)]Ri-[PO]n-[EO]m-OR2[formula (II)] wherein:Ri is C8to C20alkyl;R2is H, or Ci to Ci8alkyl, preferably H;EO is ethylene oxide;PO is propylene oxide; m + n is from 1 to 15; and m 0.

10. The water-soluble package according to any preceding claim, wherein the or each non-ionic alcohol alkoxylate has a hydrophilic-lipophilic balance (HLB) of from 10 to 15, preferably from 12 to 15, more preferably from 12 to 13, as determined by Griffin’s method.11 . The water-soluble package according to any preceding claim, wherein the PVOH comprises at least one vinyl acetate-vinyl alcohol copolymer, preferably wherein the vinyl acetate-vinyl alcohol copolymer comprises at least 85 mol% vinyl alcohol units.

12. A method for preparing a water-soluble package containing an automatic dishwashing detergent composition for release during a dishwashing cycle, the package comprising a polyvinyl alcohol (PVOH) film, wherein the film is substantially free from glycerol and 1 ,2-propylene glycol, and wherein the film comprises from 5 to 30 wt%, based on the total weight of the film, of one or more non-ionic alcohol alkoxylates having a C8to C20alkyl group alkoxylated with from 1 to 15 alkoxylate units, wherein the alkoxylate units are ethoxylate units or a mix of ethoxylate and propoxylate units, the method comprising:i) providing a PVOH solution; ii) adding the one or more non-ionic alcohol alkoxylates to the PVOH solution to form a casting solution; iii) casting the solution to form a film; iv) drying the film; v) thermoforming the film to produce at least one pocket; vi) at least partially filling the or each pocket with an automatic dishwashing detergent composition; vii) placing a second film, prepared according to steps i) to iv), on top of the or each filled pocket; and viii) sealing the two films together.

13. A method according to claim 12, wherein in step iv), the film has a dry thickness of from 70 to 120 pm.

14. A water-soluble package obtained or obtainable by the method according to claim 12 or claim 13.

15. A method for operating an automatic dishwasher, the method comprising introducing the water-soluble package according to any of claims 1 to 11 or claim 14 into the dishwasher before or during a dishwashing cycle.

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