EP4669692A1

EP4669692A1 - WATER-SOLUBLE FILMS

Info

Publication number: EP4669692A1
Application number: EP24705674.0A
Authority: EP
Inventors: Alias Younis AL-BAYATI; Torsten Roth; Jan Maurycy USZKO
Original assignee: Reckitt Benckiser Finish BV
Current assignee: Reckitt Benckiser Finish BV
Priority date: 2023-02-20
Filing date: 2024-02-16
Publication date: 2025-12-31
Also published as: CN120641476A; AU2024226133A1; GB202302371D0; WO2024175498A1

Abstract

The present invention relates to a water-soluble film comprising a plurality of protrusions on at least part of the film, the protrusions extending from or into at least part of a surface of the film, wherein the part of the water-soluble film comprising the protrusions transmits no more than 30% light having a wavelength of from 350 - 800 nm.

Description

WATER-SOLUBLE FILMS

Technical Field of the Invention

The present invention relates to translucent water-soluble films, translucent water-soluble packages and methods of their manufacture.

Background to the Invention

Water-soluble films are known to be used to package chemical compositions which may be of a hazardous or irritant nature, such as a detergent composition. The packages can simply be added to water in order to dissolve or disperse the contents of the package into the water.

In some cases, it is desirable that the package is translucent to mitigate the visibility of the degradation of any interior components.

It is known to provide multi-chamber pouches comprising three layers of water- soluble films having a white layer printed on the bottom of the pouch to reduce visibility of the interior components. Notably, this mitigates the visibility of the formula discoloration, such as yellowing of MGDA or degradation of a bleach catalyst. However, this approach requires additional processing steps and increases the complexity of the manufacturing process.

Additionally, it is also known to create a white translucent appearance in a water-soluble film by the addition of colourants and opacifiers such as dyes and pigments. In some cases, the colourants and opacifiers may be hazardous. One such example is the addition of TiO2, which is suspected to cause health issues and may require separate disposal procedures.

It is therefore an aim of the present invention to provide a water-soluble film having a translucent appearance without requiring the addition of colourants and opacifiers.

Moreover, it is an aim of the present invention to provide a method for producing a water-soluble film having a translucent appearance through a less complex manufacturing process. It is furthermore an aim of embodiments of the invention to provide an improved water-soluble package comprising a water-soluble film having a translucent appearance.

It is also an aim of embodiments of the invention to overcome at least one problem of the prior art, whether expressly disclosed herein or not.

Summary of the Invention

According to a first aspect of the present invention, there is provided a water- soluble film comprising a plurality of protrusions on at least part of the film, the protrusions extending from or into at least part of a surface of the film, wherein the part of the water-soluble film comprising the protrusions transmits no more than 30% light having a wavelength of from 350 - 800 nm.

The expression “protrusion” in the context of the present invention can also be understood as a highly irregular surface of the respective film.

The inventors surprisingly discovered that a water-soluble film having a plurality of protrusions on at least a part of the film results in a translucent film, which does not transmit more than 30% of visible light on the part of the film comprising the protrusions. This is thought to be due to the ability of the surface protrusions to scatter light. Beneficially, this means that the inventors have discovered a translucent water- soluble film which doesn’t require the addition of colorants or undesired opacifiers.

This allows the films to omit conventional whitening agents, such as titanium oxide, in coatings and/or packages in order to mask degradation of encapsulated ingredients and preserve the original aesthetic profile of the product.

The part of the film comprising protrusions may transmit no more than 25%, 20%, 19% 18%, 17%, 16% 15%, 14%, 13%, 12%, 11%, 10%, 9% 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% of light having a wavelength of from 300 - 800 nm, 350 - 800 nm, 400 - 750 nm, or 400 - 700 nm.

The part of the film comprising the protrusions may reflect and/or scatter at least 70, 80%, 85% 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% of incident light having a wavelength of from 300 - 800 nm. In some embodiments the part of the film comprising the protrusions is opaque or substantially opaque. Preferably, the part of the surface of the film comprising the protrusions has a white colour.

The white colour is thought to be due to the reflection and/or scattering of light having a wavelength of from 300 - 800 nm.

The protrusions may have one or more rounded sides. Preferably, the protrusions may have all rounded sides.

Preferably, the protrusions are substantially hemi-spherical, spherical-cap shaped or spherical.

The protrusions may cover at least 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%. In some embodiments, the protrusions may be present in an amount of no more than 99%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, or 55%. The protrusions may cover between 1 and 100% of the surface of the water-soluble film, or from 1-75%, or from 1-50% of the surface of at least one side of the water-soluble film.

The protrusions may be present over the entire surface of the water-soluble film.

The protrusions may be present over the surface of at least one side of the water- soluble film. The protrusions may cover both sides of the water-soluble film. In embodiments wherein the protrusions cover at least one surface of the film, such a film will transmit no more than 30% light having a wavelength of from 350 - 800 nm across the whole film.

The peak height of one or more of the protrusions may be less than 2000 nm. The peak height may be at least 100 nm, 200 nm, 300 nm, 400 nm, or at least 500 nm. In some embodiments the peak height may be no more than 1500 nm, 1250 nm, 1000 nm, 900 nm, 800 nm, or no more than 700 nm. Preferably, the peak height may be from 100 - 1000 nm, 200 -1000 nm, 300- 900 nm, or 400 - 800 nm.

One or more of the protrusions may have an average diameter of less than 2000 nm. The average diameter may be at least 100 nm, 200 nm, 300 nm, 400 nm, or at least 500 nm. In some embodiments the average diameter may be no more than 1500 nm, 1250 nm, 1000 nm, 900 nm, 800 nm, or no more than 700 nm. Preferably, the average diameter may be from 100 - 1000 nm, 200 -1000 nm, 300- 900 nm, or 400 - 800 nm. One or more of the protrusions may have a depth of less than 2000 nm. The depth may be at least 100 nm, 200 nm, 300 nm, 400 nm, or at least 500 nm. In some embodiments the depth may be no more than 1500 nm, 1250 nm, 1000 nm, 900 nm, 800 nm, or no more than 700 nm. Preferably, the depth may be from 100 - 1000 nm, 200 -1000 nm, 300- 900 nm, or 400 - 800 nm.

The water-soluble film preferably comprises a water-soluble polymer.

Preferred polymers (including copolymers, terpolymers, or derivatives thereof) suitable for use as a film are one or more polymers selected from the group comprising polyvinyl alcohols (PVA), polyvinyl pyrrolidone, polyalkylene oxides, acrylamide, acrylic acid, cellulose, cellulose ethers, cellulose esters, cellulose amides, polyvinyl acetates, polycarboxylic acids and salts, polyaminoacids or peptides, polyamides, polyacrylamide, copolymers of maleic/acrylic acids, polysaccharides including starch and gelatine, natural gums such as xanthum and carragum. More preferred polymers are selected from polyacrylates and water-soluble acrylate copolymers, methylcellulose, carboxymethylcellulose sodium, dextrin, ethylcellulose, hydroxy ethyl cellulose, hydroxypropyl methylcellulose, maltodextrin, polymethacrylates, and most preferably selected from polyvinyl alcohols, polyvinyl alcohol copolymers and hydroxypropyl methyl cellulose (HPMC), and combinations thereof. Preferably, the polymers of the film material are free of carboxylate groups.

The polymer may be present in an amount of at least 40%, 45%, 50%, 55%, 60%, 65%, 75%, 80%, 85%, 90% or 95% by weight of the film. In some embodiments, the polymer may be present in an amount of no more than 99%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55% or 50% by weight of the film. The water-soluble polymer may be present in an amount of from 40 to 99%, 50 to 95%, 50 to 90%, 60 to 90% by weight of the film.

The polymer can have any weight average molecular weight, preferably from about 1000 to 1,000,000, more preferably from about 10,000 to 300,000, yet more preferably from about 20,000 to 150,000.

Preferably, the water-soluble film comprises, consists essentially of, or consists of polyvinyl alcohol (PVOH).

The PVOH film may be partially or fully alcoholised or hydrolysed, for example, it may be from 40 to 100%, preferably 70 to 92%, most preferably about 85% to about 92%, alcoholised or hydrolysed, polyvinyl acetate film. 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) water, whereas 92% hydrolysis corresponds to a film soluble in warm water. 88% hydrolysis corresponds to a film soluble in cold (i. e. room temperature) water, whereas 92% hydrolysis corresponds to a film soluble in warm water.

The water-soluble film may comprise a non-solvent.

The non-solvent may be any liquid that is not able to dissolve the water-soluble polymer.

The non-solvent may be a non-polar solvent.

The non-solvent may be a glycol ether.

The glycol ether may be selected from the group consisting of propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, propylene glycol monophenyl ether, ethylene glycol monobutyl ether, di ethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether and ethylene glycol monophenyl ether.

In a preferred embodiment of the present invention, the non-solvent must be less volatile than the solvent (e.g., water) and show a slower evaporation kinetic in comparison to allow for (relative) enrichment of the non-solvent in the film.

Of course, in general, the non-solvent should also not appreciably dissolve or plasticize the water-soluble film. The protrusions may be at least partly filled with the non-solvent.

The protrusions may be fully filled with the non-solvent.

The water-soluble film may comprise a solvent.

The solvent may be any liquid capable of dissolving the water-soluble polymer.

Preferably, the solvent is water.

The film may have a thickness of at least 5, 10, 15, 20, 25, 30, 40 or 50 pm. In some embodiments, the film may have a thickness of no more than 150, 140, 130, 120, 110, 100, 90, 80, 70, 60 or 50 pm. The film may have a thickness of from 10 to 150 pm, 20 to 100 pm, 20 to 75 pm, 20 - 40 pm. Alternatively, the film may have a thickness of from 30 to 120 pm, preferably of from 40 to 110 pm, more preferably of from 50 to 100 pm.

It is also possible for suitable additives such as plasticisers, one or more processing aids lubricants, anti-blocking agents and colouring agents to be added to the film.

Plasticisers are generally used in an amount of up to 20 wt%, for example from 10 to 20 wt%. Lubricants are generally used in an amount of 0.5 to 5 wt%. The PVOH is therefore generally used in an amount of from 75 to 84.5 wt%, based on the total amount of the moulding composition. Suitable plasticisers are, for example, pentaerythritols such as depentaerythritol, sorbitol, mannitol, glycerine and glycols such as glycerol, ethylene glycol and polyethylene glycol. Solids such as talc, stearic acid, magnesium stearate, silicon dioxide, zinc stearate or colloidal silica may be used as lubricants. Suitable processing aids include mono-, di-, tri-carboxylic acids / salts thereof, fatty acids such as stearic acid / salts thereof, mono-, di- or triglycerides / 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.

According to a second aspect of the present invention, there is provided a method of producing a water-soluble film according to a first aspect of the invention, the method comprising the steps of: a) providing a substrate; b) preparing a polymer solution comprising a water-soluble polymer, a solvent and a non-solvent; c) depositing the solution on the substrate; and d) drying the solution to form a water-soluble film comprising a plurality of protrusions on at least part of the film, the protrusions extending from or into at least part of a surface of the film, wherein the part of the water-soluble film comprising the protrusions transmits no more than 30% light having a wavelength of from 350 - 800 nm. The present invention provides a much simpler process for producing a translucent water-soluble film and the process allows the formation of a translucent water-soluble film without substantial modification of the existing manufacturing processes, such as solution casting or cast-extrusion, preferably solution casting.

The water-soluble polymer may be present in an amount of at least 0.5%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5% or 6% by weight of the polymer solution. In some embodiments, the water-soluble polymer may be present in an amount of no more than 10%, 9.5%, 9%, 8.5%, 8%, 7.5%, 7%, 6.5%, or 6%, 5.5%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5% or 2% by weight of the polymer solution.

The water-soluble polymer may be present in an amount of from 0.5 to 10%, 1 to 10%, 1.5 to 10%, 1.75 to 10%, or 1-2% by weight of the polymer solution.

The non-solvent may be present in an amount of at least 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2, 1.4, 1.6, 1.8 2% by weight of the polymer solution. In some embodiments the non-solvent may be present in no more than 3%, 2.9%, 2.8%, 2.7%, 2.6%, 2.5%, 2.4%, 2.3%, 2.2%, 2.1%, or 2% by weight of the polymer solution.

The non-solvent may be present in an amount of from 0.2 to 3%, 0.2 to 1%, or 1 to 3%, by weight of the polymer solution.

The inventors discovered that the addition of a non-solvent in an amount of greater than greater than 3% was not able to form a dry film after drying for a week under ambient conditions.

The inventors also discovered that low amounts of non-solvent of below 0.2% were not able to form a film having the desired protrusions.

The solvent may be present in an amount of at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8% or 99.9%. by weight of the polymer solution. In some embodiments, the solvent may be present in an amount of no more than 99.9%, 99.8%, 99.7%, 99.6%, 99.5%, 99.4%, 99.3%, 99.2% 99.1%, 99%, 98%, 97%, 96%, 95% or 90% by weight of the polymer solution. The solvent may be present in an amount of from 80 to 99.9%, 85 to 99.9%, 90 to 99.9%, 95 to 99.9%, 98 to 99.9%, 99 to 99.9% by weight of the polymer solution.

The inclusion of a lower amount of solvent decreases the drying time of the film.

The weight ratio of the solvent to non-solvent in the polymer solution may be at least 30:1, 50:1, 100:1, or 200:1. In some embodiments the solvent to non-solvent weight ratio in the polymer solution may be no more than 500:1, 400:1, 300:1, 200:1, 100:1 or 50:1.

The weight ratio of the solvent to non-solvent in the polymer solution may be from 30:1 to 500:1.

The weight ratio of water-soluble polymer to non-solvent in the polymer solution may be at least 5:1 3: 1, 2:1 or 1: 1. In some embodiments the weight ratio of water-soluble polymer to non-solvent in the polymer solution may be no more than 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1 or 2:1.

The weight ratio of water-soluble polymer to non-solvent in the polymer solution may be from 1:1 to 10:1 or 1:1 to 8:1, 1:1 to 6:1 or 1:1 to 5:1.

The substrate may be any suitable material that can act as a casting surface.

The substrate may be a metal, glass or polymeric material.

The substrate may be silicon or a silicon derivative.

The metal may be any metal that can act as a casting surface, such as nickel, aluminium and silver.

The polymeric material may be any polymeric material that can act as a casting surface, such as polyethylene terephthalate (PET), polyethylene, polytetrafluoroethylene, polypropylene, duroplast, polyvinyl chloride, polytetrafluoroethylene, polycarbonate, Cyclic olefin copolymer or poly(methyl methacrylate) and polyamide.

In a third aspect of the present invention, there is provided a water-soluble package comprising a water-soluble film according to the present invention. The water- soluble film may be produced using a method of the second aspect of the invention. At least part of the water-soluble package may be translucent, and in some embodiments the whole water-soluble package may be translucent.

Beneficially, the use of a water-soluble film according to the first aspect of the present invention in a water-soluble package can mask the degradation of any encapsulated ingredients. This can preserve the original aesthetic appearance of the package.

The water-soluble package may be a detergent package.

The water-soluble package may be a detergent package having one or more compartments.

The detergent package may be a multi-compartment package.

The protrusions of the water-soluble film may be on the areas of the film making up the one or more compartments. Preferably, the protrusions will be present on more than one of the compartments, more preferably all of the compartments.

The detergent package may comprise a flange or rim.

The protrusions may be on the areas of the film making up the flange or rim of the detergent package.

In one embodiment, the protrusions may only be present on one or more compartments of the detergent package.

Alternatively, the protrusions may be present on only the flange or rim of the detergent package.

Alternatively still, the protrusions may be present on one or more compartments and the flange or rim. More preferably, the protrusions may be present on the flange or rim and all of the compartments.

In a fourth aspect of the invention there is provided a water-soluble package of the third aspect of the invention, containing a composition.

In a fifth aspect of the invention there is provided a method for preparing a water-soluble package according to the third aspect of the present invention, the process comprising: a) thermoforming a first film of the present invention to produce at least one pocket; b) at least partially filling the or each pocket with a composition; and c) placing a second film, preferably a polyvinyl alcohol film, on top of the or each filled pocket; and d) sealing the first film and second film together.

In some embodiments the second film is also a film of the present invention.

The pocket may comprise a flange or rim, and the second film may be sealed to the first film at least on the flange or rim.

The composition may be placed in the pocket in step b) and the second film placed on the flange or rim and across the pocket.

Step a) may comprise thermoforming more than one pocket in the film, such as two, three or four pockets. Each pocket may be filled with a different composition, the same composition, or any combination of compositions.

The or each pocket may be completely filled with a composition in step b). Partial filling of each pocket may reduce the risk of rupture of the package, if the package is subjected to shock, and may reduce the risk of leakage if the package is subject to high temperatures.

The films are sealed together in step d), for example by heat sealing across a flange or rim. A suitable heat-sealing temperature is, for example between 120 to 195 °C, such as 140 to 190 °C. A suitable sealing pressure is, for example, from 250 to 800 kPa. Examples of sealing pressures are 276 to 552 kPa (40 to 80 p.s.i.), especially 345 to 483 kPa (50 to 70 p.s.i.) or 400 to 800 kPa (58 to 116 p.s.i), especially 500 to 700 kPa (72.5 to 101.5 p.s.i) depending on the heat-sealing machine used. Suitable sealing dwell times are at least 0.4 seconds, for example 0.4 to 2.5 seconds. Other methods of sealing the films together may be used, for example infrared, radio frequency, ultrasonic, laser, solvent, vibration, electromagnetic, hot gas, hot plate, insert bonding, fraction sealing or spin welding. An adhesive, such as water or an aqueous solution of polyvinyl alcohol may also be used. The adhesive can be applied to the films by spraying, transfer coating, roller coating or otherwise coating, or the films can be passed through a mist of the adhesive. The seal desirably is also water-soluble.

The first film of the invention may generally have a thickness before thermoforming of 20 to 500 pm, especially 50 to 400 pm, for example 70 to 300 pm, most preferably 70 to 160 pm, especially 80 to 150 pm. The thickness of the second film may be less than that of the first film as the second film may not generally be thermoformed, so localised thinning of the film may not occur. The thickness of the second film may generally be from 20 to 150 gm, preferably from 40 to 90 or 100 gm, more preferably from 30 to 90 pm. However, a film having a thickness of 70 to 150 pm may also be used.

The composition filling the packages is not particularly limited. It can be any composition which is to be added to an aqueous system or used in an aqueous environment.

The composition may be a dishwashing composition, water-softening composition, laundry composition, hard surface cleaning composition, concentrated cleaning composition, dilutable cleaning composition or detergent composition or a rinse aid. In this case it is especially suitable for use in a domestic washing machine such as a laundry washing machine or, especially, a dishwashing machine, including an automatic dishwashing machine.

The nature of the composition in each pocket is not limited. It may, for example, be independently a solid, liquid or gel in each pocket. If it is in the form of a solid it may, for example, be in the form of a powder, granules, an extruded tablet, a compressed tablet or a solidified gel. If it is in the form of a liquid, it may be optionally thickened or gelled with a thickener or a gelling agent. One or more than one phase may be present. For example, each pocket may be independently filled with a liquid composition, a separate solid composition, for example in the form of a ball, pill, granules or speckles and a separate gel composition. Alternatively, two or more solid phases may be present, or two or more immiscible liquid phases.

Thus, the composition in each pocket need not be uniform. For example, during the manufacture at least one pocket could first be filled with a settable composition, for example a gel, and then with a different composition such as a liquid, especially an aqueous, composition, or the compositions could be filled in separate pockets. The first composition could dissolve slowly, for example in a washing process, so as to deliver its charge over a long period. This might be useful, for example, to provide an immediate, delayed or sustained delivery of a component such as a softening agent.

If more than one package is formed at the same time, the packaged compositions may then be separated from each other. Alternatively, they may be left conjoined, and, for example, perforations provided between the individual packages so that they can be easily separated at a later stage, for example by a consumer or during further processing of the packages.

If the packages are separated, the flanges may be left in place. However, desirably the flanges are partially removed in order to provide an even more attractive, three-dimensional appearance. Generally, the flange remaining should be as small as possible for aesthetic purposes while bearing in mind that some flange is required to ensure the two films remain adhered to each other. A flange of 0,1 mm to 5 mm is desirable, preferably 0,5 mm to 4 mm, more preferably 1 mm to 3 mm, most preferably about 2 mm.

The packages may then be left to absorb water from the atmosphere or may be immediately packaged into boxes for retail sale. The packages may themselves be packaged in outer packages if desired, for example non-water-soluble outer packaging material which is removed before the water-soluble packages are used.

The packages of the present invention generally contain from 5 to 100 g of composition, such as an aqueous composition, especially from 5 to 40 g, depending on their intended use. For example, a dishwashing composition may weigh from 8 to 30 g, a water-softening composition may weigh from 10 to 30 g, and a laundry composition may weigh from 10 to 40 g, especially 10 to 30g.

The pockets may have any shape. For example, they can take the form of an envelope, sachet, sphere, hemisphere, segment of a sphere, cylinder, cube (including rounded cubes) or cuboid (including rounded cuboids), i.e. a rectangular parallelepiped whose faces are not all equal; or an irregular shape. In general, because the packages are not rigid and are inflated, the sides are not planar, but rather are convex. If the package is formed from a thermoformed film and a planar film, the seam between the two films will appear nearer one face of the package rather than the other. Apart from the deformation of the package due to shrinkage of the polyvinyl alcohol films after the package is manufactured, deformation may also occur at the stage of manufacture if desired. For example, if the pocket is filled with a solid or gelled composition (for example in the form of a tablet) having a height greater than that of the pocket, the second film will be deformed when placed on top of the pocket. In general, the maximum dimension of the filled part (pocket) of the package (excluding any flanges) is 10cm x 10cm, preferably 8cm x 8cm. For laundry detergent compositions, the maximum dimension of the filled part of the package is preferably 8cm x 8cm, whilst for automatic dishwashing detergent compositions, the maximum dimension may be smaller, such as no more than 6cm x 6cm, for example.

The composition may contain surface active agents such as anionic, nonionic, cationic, amphoteric or zwitterionic surface active agents or mixtures thereof.

Dishwashing compositions may comprise a detergency builder. The builder is preferably a phosphate-free builder. The builder may comprise one or more small molecule builders selected from hydroxycarboxylates (such as a citrate salt, for example trisodium citrate, which may be anhydrous), aminocarboxylates (such as methyl glycine diacetic acid (MGDA), or N,N-dicarboxymethyl glutamic acid (GLDA), dicarboxylic acid amines (such as iminodisuccinic acid (IDS) and/or phosphates (such as tripolyphosphate) , or the salts thereof.

The compositions, particularly when used as laundry washing or dishwashing compositions, may also comprise enzymes, such as protease, lipase, amylase, cellulase and peroxidase enzymes.

The compositions may, if desired, comprise a thickening agent or gelling agent.

The compositions can also optionally comprise one or more additional ingredients. These include conventional detergent composition components such as further surfactants, bleaches, bleach activators, bleach catalysts, bleach enhancing agents, builders, suds boosters or suds, suppressors, anti-tarnish and anticorrosion agents, organic solvents, co-solvents, phase stabilisers, emulsifying agents, preservatives, soil suspending agents, soil release agents, germicides, pH adjusting agents or buffers, nonbuilder alkalinity sources, chelating agents, clays such as smectite clays, enzyme stabilizers, anti-limescale agents, colourants, dyes, hydrotropes, dye transfer inhibiting agents, brighteners and perfumes. If used, such optional ingredients will generally constitute no more than 10 wt.%, for example from 1 to 6 wt.%, of the total weight of the compositions.

Compositions which comprise an enzyme may optionally contain materials which maintain the stability of the enzyme. Such enzyme stabilizers include, for example, polyols such as propylene glycol, boric acid and borax. Combinations of these enzyme stabilizers may also be employed. If utilized, the enzyme stabilizers generally constitute from 0.1 to 1 wt.% of the compositions.

The compositions may optionally comprise components which adjust or maintain the pH of the compositions at optimum levels. Examples of pH adjusting agents are NaOH and citric acid. The pH may be from, for example, 1 to 13, such as 8 to 11 depending on the nature of the composition. For example, a dishwashing composition desirably has a pH of 8 to 11, a laundry composition desirably has a pH of 7 to 9, and a water-softening composition desirably has a pH of 7 to 9.

Preferably, the composition is an automatic dishwashing composition.

In a further aspect of the present invention there is provided an enzyme granule coated with a film according to the first aspect of the present invention.

The enzyme may be a protease, lipase, amylase, cellulase and/or peroxidase enzyme.

In a further aspect of the present invention, there is provided a bleach catalyst co-granule coated with a film according to the first aspect of the present invention.

The bleach catalyst co-granule may be a manganese bleach catalyst or a cogranule of bleach catalyst with bleach booster or other auxiliaries.

In a further aspect of the present invention, there is provided the use of a water- soluble film according to the present invention to package a detergent or laundry composition, which composition may be as described hereinabove.

In a further aspect of the present invention, there is provided the use of a water- soluble film according to the present invention in a coating. The coating may be a coating for an enzyme granule or bleach catalyst co-granule as described hereinabove.

The further aspects of the present invention may incorporate any of the features of the other aspects of the invention described herein as desired or as appropriate. Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1 A-1D show an image of water-soluble films according to the present invention described in Example 4 (Figure 1A) and Example 5 (Figure IB), and a water-soluble film not according to the present invention described in Reference Example 6 (Figure 1C) and Reference Example 7 (Figure ID).

Figure 2A-2B shows an Optical microscope Image (Keyence VHX-7000 comprising a VHX-E100 lens)(Figure 2A) and a 3D image of a film (Figure 2B) according to the present invention described in Example 1.

Figure 3A-3D is a scanning electron microscope image (Phenom™ ProX Desktop Scanning Electron Microscope) of a water-soluble film according to the present invention described in Example 1 at 840x magnification (Figure 3A) and 4900x magnification (Figure 3B) and a water-soluble film not according to the present invention described in Reference Example 8 at 840x magnification (Figure 3C) and 4900x magnification (Figure 3D).

Figure 4A-4C is an image showing the difference in translucency of a water-soluble film according to the present invention described in Example 4 before contact of the surface of the film with a non-solvent (Figure 4A), after contact of the surface of the film with a non-solvent (Figure 4B) and after evaporation of the non-solvent from the film of Figure 4B (Figure 4C).

Example 1

0.3 g of polyvinyl alcohol water soluble polymer (Solublon GA 90) was dissolved in a mixture of 49.6 g deionized water solvent and 0.1 g of a propylene glycol phenyl ether non-solvent (Dowanol™ PPH) to form a polymer solution. The polymer solution comprised 99.2% solvent, 0.2% non-solvent and 0.6% water-soluble polymer by weight of the polymer solution. The polymer solution was then deposited in a 3500 mL glass crystallising dish and left at ambient conditions of 21 °C and 34% relative humidity for 24 hours to form a translucent water-soluble film having protrusions and a thickness of 30 pm. As shown in Figures 2A-2B and 3A-3B, the surface structure comprised a plurality of spherical protrusions filled with the non-solvent.

Example 2 0.3 g of polyvinyl alcohol water soluble polymer (Solublon GA 90) was dissolved in a mixture of 24.8 g deionized water solvent and 0.1 g of a propylene glycol phenyl ether non-solvent (Dowanol™ PPH) to form a polymer solution. The polymer solution comprised 98.4% solvent, 0.4% non-solvent and 1.2% water-soluble polymer by weight of the polymer solution. The polymer solution was then deposited in a 3500 mL glass crystallising dish and left at ambient conditions of 21 °C and 34% relative humidity for 24 hours to form a translucent water-soluble film having a protrusions. The surface structure comprised a plurality of spherical protrusions filled with the nonsolvent.

Example 3

0.3 g of polyvinyl alcohol water soluble polymer (Solublon GA 90) was dissolved in a mixture of 2.96 g deionized water solvent and 0.1 g of a propylene glycol phenyl ether non-solvent (Dowanol™ PPH) to form a polymer solution. The polymer solution comprised 88.1% solvent, 2.98% non-solvent and 8.9% water-soluble polymer by weight of the polymer solution. The polymer solution was then deposited in a 3500 mL glass crystallising dish and left at ambient conditions of 21°C and 34% relative humidity for 24 hours to form a translucent water-soluble film having a protrusions. The surface structure comprised a plurality of spherical protrusions filled with the nonsolvent.

Example 4

0.3 g of polyvinyl alcohol water soluble polymer (Solublon GA 90) was dissolved in a mixture of 15 g deionized water solvent and 0.1 g of a propylene glycol phenyl ether non-solvent (Dowanol™ PPH) to form a polymer solution. The polymer solution comprised 97.4% solvent, 0.65% non-solvent and 1.95% water-soluble polymer by weight of the polymer solution. The polymer solution was then deposited in a 3500 mL glass crystallising dish and left at ambient conditions of 21 °C and 34% relative humidity for 24 hours to form a translucent water-soluble film having a protrusions, as shown in Figure 1A. The surface structure comprised a plurality of spherical protrusions filled with the non-solvent.

Example 5 0.3 g of polyvinyl alcohol water soluble polymer (Solublon GA 90) was dissolved in a mixture of 15 g deionized water solvent and 0.3 g of a propylene glycol phenyl ether non-solvent (Dowanol™ PPH) to form a polymer solution. The polymer solution comprised 96.2% solvent, 1.92% non-solvent and 1.92% water-soluble polymer by weight of the polymer solution. The polymer solution was then deposited in a 3500 mL glass crystallising dish and left at ambient conditions of 21 °C and 34% relative humidity for 24 hours to form a translucent water-soluble film having a protrusions, as shown in Figure IB. The surface structure comprised a plurality of spherical protrusions, filled with the non-solvent.

Reference Example 6

0.3 g of polyvinyl alcohol water soluble polymer (Solublon GA 90) was dissolved in a mixture of 15 g deionized water solvent and 0.5 g of a propylene glycol phenyl ether non-solvent (Dowanol™ PPH) to form a polymer solution. The polymer solution comprised 94.9% solvent, 3.16% non-solvent and 3.8% water-soluble polymer by weight of the polymer solution The polymer solution was then deposited in a 3500 mL glass crystallising dish and left at ambient conditions of 21 °C and 34% relative humidity for 24 hours. After 24 hours the composition was still wet due to the increased amount of non-solvent present and therefore was unable to form a water-soluble film, as shown in Figure 1C.

Reference Example 7

0.3 g of polyvinyl alcohol water soluble polymer (Solublon GA 90) was dissolved in a mixture of 15 g deionized water solvent and 0.03 g of a propylene glycol phenyl ether non-solvent (Dowanol™ PPH) to form a polymer solution. The polymer solution comprised 97.8% solvent, 0.19% non-solvent and 1.96% water-soluble polymer by weight of the polymer solution The polymer solution was then deposited in a 3500 mL glass crystallising dish and left at ambient conditions of 21 °C and 34% relative humidity for 24 hours to form a transparent water-soluble film as shown in Figure ID. The water-soluble film did not comprise a plurality of protrusions on the surface of the film. This is thought to be due to the low amount of non-solvent present in the manufacturing process. Reference Example 8

0.3 g of polyvinyl alcohol water soluble polymer (Solublon GA 90) was dissolved in a mixture of 15 g deionized water solvent to form a polymer solution. The polymer solution was then deposited in a 3500 mL glass crystallising dish and left at ambient conditions of 21 °C and 34% relative humidity for 24 hours to form a transparent water-soluble film. The water-soluble film did not comprise a plurality of protrusions on the surface of the film, as shown in Figure 3C and 3D.

Example 9

A water-soluble package having protrusions on the surface of the film was prepared according to a method of the present invention. A first PVOH film comprising protrusions on the surface of the film was thermoformed to a produce a pocket and the pocket was filled with a detergent composition. A second PVOH film was then placed on top of the filled pocket. A heating plate was pressed onto the first film at a temperature of 165°C for 2 seconds to seal the first film to the second film to form a translucent water-soluble package.

Optical Analysis

The translucency of the films of Example 4 and reference Example 8 were measured using a METROHM 662 photometer. Five measurements were recorded at a wavelength of 500 pm and 700 pm and the average amount of light transmitted is shown in Table 1 below.

As shown in the table, the film according to the present invention reflected and/or scattered a large amount of the incident light. In contrast, the reference example did not reflect and/or scatter a large amount of incident light. This is due to the protrusions formed on the surface of the films of the present invention. As shown in Figure 2, analysis of the surface of the film of Example 1 under an optical microscope revealed the presence of spherical protrusions on the surface.

Without being bound by theory, it is thought that the spherical protrusions are as a result of solvent inclusions in the surface of the film.

As a result, the protrusions are filled with the non-solvent.

Analysis of the surface of Example 1, as shown in Figures 1A-1B under a scanning electron microscope appeared to display a number of burst protrusions. This is thought to be due to the high vacuum conditions or gold spluttering process employed for the scanning electron microscope sample preparation. However, the presence of the burst protrusions provides evidence of the plurality of protrusions present on the surface of the film.

Method for determining that the surface scattering is due to surface structure

To demonstrate that the translucency of the films is as a result of the surface protrusions and not the inherent bulk of the water-soluble film, a drop of propylene glycol phenyl ether non-solvent (Dowanol™ PPH) was placed on the surface of the film of Example 4. Once contacted with the non-solvent, the film changed from translucent as shown in Figure 5 A to transparent as shown in Figure 5B. This is thought to be due to the disruption of the surface protrusions by the addition of the non-solvent. The original translucency of the film was then restored upon drying and evaporation of the non-solvent. This is thought to be due to re-formation of the surface protrusions.

The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.

Claims

1. A water-soluble film comprising a plurality of protrusions on at least part of the film, the protrusions extending from or into at least part of a surface of the film, wherein the part of the water-soluble film comprising the protrusions transmits no more than 30% light having a wavelength of from 350 - 800 nm.

2. A film according to claim 1, wherein the protrusions are substantially hemispherical, spherical-cap shaped or spherical.

3. A film according to claim 1 or 2, wherein the protrusions extend across at least 50% of the surface of the film; wherein preferably the protrusions extend across 100% of the surface of the film.

4. A film according to any preceding claim, wherein the protrusions have an average diameter of less than 1000 nm.

5. A film according to any preceding claim, wherein the film comprises a water- soluble polymer; wherein preferably the water-soluble polymer is PVA.

6. A film according to any preceding claim wherein the film comprises a solvent; wherein preferably the solvent is water.

7. A film according to any preceding claim, wherein the film comprises a nonsolvent; wherein preferably the non-solvent is a glycol ether.

8. A film according to any preceding claim, wherein the protrusions are at least partly filled with non-solvent.

9. A method of producing a water-soluble film according to any one of claims 1 to 8, the method comprising the steps of: a) providing a substrate; b) preparing a polymer solution comprising a water-soluble polymer, a solvent and a non-solvent; c) depositing the solution on the substrate; and d) drying the solution to form a water-soluble film comprising a plurality of protrusions on at least part of the film, the protrusions extending from or into at least part of a surface of the film, wherein the part of the water-soluble film comprising the protrusions transmits no more than 30% light having a wavelength of from 350 - 800 nm.

10. A method according to claim 9, wherein the water-soluble polymer is present in an amount of from 0.5% to 10% by weight of the polymer solution.

11. A method according to claim 9 or 10, wherein the non-solvent is present in an amount of from 0.2% to 3% by weight of the polymer solution.

12. A method according to one of the preceding claims 9 to 11, wherein the solvent is present in an amount of from 80% to 99.9% by weight of the polymer solution.

13. A water-soluble package comprising a water-soluble film according to any one of claims 1 to 8; wherein preferably the package is a detergent package.

14. A package according to claim 13, wherein the package is a multicompartment package; wherein preferably the protrusions are on more than one of the compartments of the multicompartment package.

15. Use of a water-soluble film according to any one of claims 1 to 8 to package a detergent or laundry composition; or as a coating for a granule or bleach catalyst co-granule.