The present invention relates to water-soluble cleaning agent containers having a rigid container body, the use of the cleaning agent product in cleaning, particularly in laundry, and method of making the rigid container body.

Cleaning agents, such as laundry detergents, can be delivered to items to be cleaned in many ways. For example, laundry detergents can be in the form of a solid powder, a liquid, a gel or a solid block. Single dosing of cleaning agents is a useful development because it allows an appropriate amount of cleaning agent to be delivered to the item to be cleaned. In such a way, the user is not concerned with measuring the appropriate amount of cleaning agent. In addition, the cleaning efficacy is not compromised by measuring inaccuracies. Examples of single dosing cleaning products include solid cleaning agent tablets, thin water-soluble films encasing a cleaning agent, and cleaning agents contained in rigid, water-soluble containers or capsules.

WO 01/36290 describes an example of a rigid water-soluble container. The container protects the user from potentially irritant contents while handling. In addition, the container is required to sufficiently dissolve in use, for example, when added to a laundry wash. The container is made of an injection moulded polymer such as polyvinyl alcohol (PVOH or PVA) and/or a cellulose ether such as hydroxypropylmethyl cellulose (HPMC). Such containers, being rigid, allow a uniform appearance, can provide more than one compartment within the container, and are easy to fill on a production line. WO 01/36290 describes an example container with reference to Figure 1 . It is described that the container of Figure 1 can be filled with a dishwashing composition. The container is made of PVOH and has a main container wall with a thickness of about 0.7 mm and a thin- film PVOH lid with a thickness of about 80 μιτι. It is speculated that the entire container will dissolve over the entire dish wash. There are a large number of known water-soluble polymers that may be used as product containers. For example, PVOH is a nontoxic material with good film forming properties and is generally recognised to be biodegradable.

WO 2014/155059 notes that the excellent film and thin-wall container forming properties of PVOH are dependent on humidity resulting in adsorption of water which reduces the tensile strength. As a result, it is difficult to successfully extrude PVOH or PVOH-containing compositions and, in particular it is difficult to readily mould to a minimum thickness required (less than 200 microns) to ensure product release at low aqueous temperatures, typically at or below 5 °C in less than 2 minutes. WO 2014/155059 aims to address this drawback and describes the use of a hygroscopic salt as an internal lubricant for water-soluble polymers, in particular PVOH. The adsorption of water by the hygroscopic salt from the surrounding polymer is said to provide a self-lubricating coating on the salt. As a result, the internal polymer lubricant reportedly renders the water-soluble polymer extrudable and/or mouldable. The polymer compositions are considered to be suitable for the manufacture of any article currently made from extrudable polymers and the document lists a large number of potential uses and exemplify, amongst many others, detergent and agrochemical sachets and containers.

The production of cleaning agent containers is a bespoke and challenging field with unique processing requirements and customer demands. The present invention aims to provide improved single dosing cleaning agent containers by providing a rigid cleaning agent container body that has excellent stability prior to use and yet maintains suitable water solubility. At its most general, the present invention provides a water-soluble cleaning agent container having a rigid container body made of a water-soluble polymer material, the water-soluble polymer material containing a water-soluble polymer and a hygroscopic salt. In a first aspect, the present invention provides a water-soluble cleaning agent container including a rigid container body, wherein the rigid container body is made of a water-soluble polymer material comprising a water-soluble polymer and a hygroscopic salt, the hygroscopic salt being present in the polymer material in an amount of at least 15 % by weight based on the total weight of the polymer material.

The problem solved by the present invention is to provide a cleaning product container that has excellent stability prior to use and yet maintains a suitable water solubility. In particular, the present invention provides a rigid cleaning agent container that has improved stability towards water prior to use while maintaining a good dissolution profile. The stability of the container with respect to water is important when, for example, the container is kept in a humid environment or when a user inadvertently wets the container when handling another container with wet hands. The combination of water stability prior to use and yet an excellent dissolution profile is surprisingly achieved in the present invention by including a hygroscopic salt in the water-soluble polymer material of the container body. Furthermore, such a container body is easy to produce because the polymer composition used to make the container body has excellent processability properties, especially injection moulding processability to form a single piece container body.

The rigid containers of the present invention are particularly useful as rigid laundry detergent containers. Laundry detergent containers are typically exposed to lower water temperatures and/or shorter wash times than, for example, dishwasher containers. As a result, it is more of a challenge to provide a rigid laundry detergent container (for example with relatively thick wall of at least 200 μιτι) while providing a container that will substantially dissolve at moderate temperatures and wash times. Surprisingly, the rigid containers of the present invention have a suitable stability, rigidity and dissolution profile for use as laundry detergent containers. In addition, the hygroscopic salt is generally compatible with other components in the water-soluble polymer material described herein. Furthermore, the inclusion of the hygroscopic salt does not adversely affect the appearance of the polymer material. Visual appearance of cleaning agent containers is an important factor commercial factor in the production of cleaning agent containers. For example, a consumer may not purchase a cleaning agent container that is perceived to be unattractive.

In a second aspect, the present invention provides a cleaning product comprising a water-soluble cleaning agent container, wherein the water-soluble container has a rigid container body made of a water-soluble polymer material comprising a water-soluble polymer and a hygroscopic salt, the hygroscopic salt being present in the polymer material in an amount of at least 15 % by weight based on the total weight of the polymer material, and a cleaning agent disposed in the cleaning agent container body.

In a third aspect, the present invention provides use of a cleaning product to clean an item, wherein the product cleaning product comprises a water-soluble cleaning agent container, wherein the water-soluble container has a rigid container body made of a water-soluble polymer material comprising a water-soluble polymer and a hygroscopic salt, the hygroscopic salt being present in the polymer material in an amount of at least 15 % by weight based on the total weight of the polymer material, and a cleaning agent disposed in the cleaning agent container body. In a fourth aspect, the present invention provides a method of making a water- soluble cleaning agent container having a rigid container body, the method comprising the step of injection-moulding a water-soluble composition into a single piece having a container base, one or more container walls extending from the container base, the container wall or walls defining a cleaning agent cavity, and one or more partition walls forming two more component compartments in the cleaning agent cavity, the composition including a water-soluble polymer and at least 15 % by weight of a hygroscopic salt based on the total weight of the polymer composition.

In a fifth aspect, the present invention provides a water-soluble cleaning agent container including a rigid container body obtained by the method of the fourth aspect.

The preferred features of the water-soluble cleaning agent container, a cleaning product including the water-soluble cleaning agent container and a cleaning agent, use of the cleaning product to clean an item, and method of producing the water-soluble cleaning agent container are described herein.

Water-Soluble Container

The water-soluble cleaning agent container includes a rigid container body made of a water-soluble polymer material comprising a water-soluble polymer and a hygroscopic salt, the hygroscopic salt being present in the polymer material in an amount of at least 15 % by weight based on the total weight of the polymer material. Container Body

The container body of the present invention is rigid. The term "rigid" as used herein means that the containers generally maintain their shape under resting conditions. In other words, the material of the container body is self-supporting. The rigid container body of the present invention may be elastically deformable or inflexible.

Typically, the container body has one or more container walls defining a cleaning agent cavity. The cleaning agent may be deposited and held in the cleaning agent cavity. In preferred embodiments, the container wall or walls of the present invention are made of the water-soluble polymer material. In this way, the cleaning agent held in the cleaning agent cavity can be released from the container when the water-soluble polymer material of the container walls dissolve in water (such as in a laundry washing cycle).

In some embodiments, the container body includes a container base and at least one container wall extending from the container base. The container wall or walls may be a hollow sphere, a hollow cone, a hollow truncated cone, a hollow cylinder or be formed from three or more flat surfaces. In some embodiments, the container base will be substantially flat. In preferred embodiments, the container body includes a flat base and a hollow conical or hollow cylindrical container wall extending from the base.

The container body typically has a container body inlet into the cleaning agent cavity. The container body inlet is typically an aperture in one of the container walls. When the container body includes a conical or cylindrical container wall, the aperture may be formed from an upper rim of the container wall.

The cleaning agent cavity typically holds a single dose of cleaning agent.

Accordingly, the volume of the cavity may be adapted to hold a single dose of cleaning agent. The volume of the cleaning agent cavity may be in the range of 5 to 75 ml, preferably, in the range of 20 to 60 ml.

Component Compartments

The container body typically has one or more container walls defining a cleaning agent cavity. The cleaning agent cavity may form a single component

compartment. Alternatively, the cleaning agent cavity may be divided into two or more component compartments by one or more cavity partition walls. In this way, the compartments may hold two or more different cleaning agent components. Alternatively, the compartments may hold one or more cleaning agent

components and one or more additional components. In some embodiments, the cleaning agent cavity includes two, three or four component compartments. In preferred embodiments, the cleaning agent cavity includes two component compartments.

When the cleaning agent cavity includes two or more component compartments, the size of each component compartment relative to the other compartments is not particularly limited. For example, the size of each component compartment may vary depending on the required volume of each component. In some embodiments, each component compartment will occupy about the same volume within the cleaning agent cavity.

Container Body Wall Thickness

The thicknesses of the container wall or walls, container base, partition walls are not particularly limited, so long as the container body is rigid. Typically, the thickness of the container wall or walls, container base and/or partition walls is 200 μιτι or more. In some embodiments, the thickness of the container wall or walls, container base and/or partition walls is 300 μιτι or more, 400 μιτι or more, 500 μιτι or more, or 600 μιτι or more.

In some embodiments, the thickness of the container wall or walls, container base and/or partition walls is in the range of 0.2 to 5 mm. In some embodiments, the thickness of the container wall or walls, container base and/or partition walls is in the range of 0.3 to 4 mm, 0.4 to 3.5 mm, 0.5 to 3 mm or 0.6 to 2.5 mm.

The containers of the present application can be made with substantially all of the container wall or walls, all of the container base and/or all of the partition wall or walls having a wall thickness above the minimum wall thickness or within the wall thickness ranges given above. In other embodiments, part of one or more of the container wall or walls, part of the container base and/or part of one or more of the partition wall or walls have a portion of said container wall or walls, container base and/or partition wall or walls with a wall thickness below the minimum wall thickness or outside of the wall thickness ranges given above, so long as the container maintains its rigidity.

Lid

Typically the water-soluble container will include a lid to seal the cleaning agent cavity. The lid may cover the container body inlet. The lid will typically be a complementary shape to the container inlet such that the lid and container fit together to seal the container. The lid may be a separate piece to the container body. A separate lid and container body will typically be easy to manufacture. Alternatively, the lid is attached to or integral to a container wall of the container. Such attachment may be a hinged attachment. The lid may be flexible or rigid. In some embodiments, the lid is a rigid water- soluble polymer piece. In alternative embodiments, the lid is a water-soluble polymer film. The film may be adhered to an upper rim of the container wall or walls. In preferred embodiments, the lid is a rigid water-soluble polymer piece made of a water-soluble polymer material described herein.

Water-soluble Polymer Material

The water-soluble polymer material comprises a water-soluble polymer and a hygroscopic salt, the hygroscopic salt being present in the polymer material in an amount of at least 15 % by weight based on the total weight of the polymer material. The water-soluble polymer material forms at least part of the container body. In preferred embodiments, the container base and one or more container walls are made of a water-soluble polymer material described herein. In some embodiments, one or more of the cavity partition walls, when present, are made of a water-soluble polymer material described herein. In other embodiments, the lid of the container is made of a water-soluble polymer material described herein. In some embodiments, all exterior surfaces are made of a water-soluble polymer material described herein. In this way, the container protects the cleaning agent from environmental moisture. In particularly preferred embodiments, the container includes a flat base, one or more container walls, one or more of the cavity partition walls and a lid and each of the flat base, one or more container walls, one or more of the cavity partition walls and the lid are made of a water-soluble polymer material described herein.

Water-Soluble Polymer

Water-soluble polymers per se are known. In preferred embodiments, the water- soluble polymer is a biodegradable water-soluble polymer. In preferred

embodiments, the water-soluble polymer is selected from a polyvinyl alcohol polymer, a cellulose ether polymer or a mixture thereof. In preferred embodiments, the water-soluble polymer is a polyvinyl alcohol polymer. The degree of hydrolysis of the polyvinyl alcohol polymer of the present invention is not particularly limited. In some embodiments, the polyvinyl alcohol polymer is partially hydrolysed polyvinyl alcohol. In other embodiments, the polyvinyl alcohol polymer is fully hydrolysed polyvinyl alcohol. The molecular weight of the polyvinyl alcohol polymer is not particularly limited. In some embodiments, the weight average molecular weight of the polyvinyl alcohol polymer is 20,000 or more. In other embodiments, the weight average molecular weight of the polyvinyl alcohol polymer is 150,000 or less. In other embodiments, the weight average molecular weight of the polyvinyl alcohol polymer is in the range of 20,000 to 150,000.

In alternative embodiments, the water-soluble polymer is a cellulose ether polymer. A particular example of a cellulose ether polymer is a

hydroxypropylmethylcellulose (HPMC). Hvaroscopic Salt

Hygroscopic salts are salts capable of attracting water from the surrounding environment, for example by adsorption or absorption. Such hygroscopic salts are known per se.

In some embodiments, the hygroscopic salt is an alkaline or alkaline earth metal salt. The hygroscopic salt may be an anhydrous or a hydrated alkaline or alkaline earth metal salt. In preferred embodiments, the hygroscopic salt includes an anhydrous alkaline or alkaline earth metal salt.

Examples of hygroscopic salts include, but are not limited to, sodium chloride, sodium citrate, calcium chloride, magnesium chloride, zinc chloride, potassium carbonate, potassium phosphate, carnallite, ferric ammonium citrate, potassium hydroxide, and sodium hydroxide.

In some embodiments, the hygroscopic salt is selected from the group consisting of sodium chloride, sodium citrate, magnesium chloride and mixtures thereof. In particular embodiments, the hygroscopic salt is sodium chloride or sodium citrate. The hygroscopic salt is included in the water-soluble polymer material of the container in at least 15 % by weight based on the total weight of the polymer material. In some embodiments, the hygroscopic salt is included in the water- soluble polymer material in an amount of 20 % or more by weight based on the total weight of the polymer material. In particular embodiments, the hygroscopic salt is included in the water-soluble polymer material in an amount of 40 % or more by weight based on the total weight of the water-soluble polymer material. In preferred embodiments, the hygroscopic salt is included in the water-soluble polymer material in an amount of 50 % or more by weight based on the total weight of the water-soluble polymer material. Typically, the hygroscopic salt can be included in the water-soluble polymer material up to and including 75 % by weight based on the total weight of the water-soluble polymer material. In some embodiments the hygroscopic salt can be included in the water-soluble polymer material up to and including 70 % by weight based on the total weight of the water-soluble polymer material. In some embodiments the hygroscopic salt can be included in the water-soluble polymer material up to and including 65 % by weight based on the total weight of the water-soluble polymer material. Accordingly, the hygroscopic salt may be included in the water-soluble polymer material of the container in the range of 15 % to 75 % by weight based on the total weight of the polymer material. In some embodiments, the hygroscopic salt is included in the water-soluble polymer material of the container in the range of 40 % to 70 % by weight based on the total weight of the polymer material. In some embodiments, the hygroscopic salt is included in the water-soluble polymer material of the container in the range of 50 % to 65 % by weight based on the total weight of the polymer material.

In some embodiments, the hygroscopic salt is micronized. In embodiments, the average particle diameter of the hygroscopic salt is less than 100 μιτι. In some embodiments, the average particle diameter of the hygroscopic salt is in the range of 0.03 to 75 μιτι. In particular embodiments, the hygroscopic salt has an average particle diameter in the range of 60 to 70 μιτι. In some embodiments, the hygroscopic salt has a coating layer. Such a coating layer may improve the salt particle properties. For example, the coating may act as an anti-caking agent. The hygroscopic salt coating layer may include sodium aluminosilicate, silicon dioxide and/or sodium hexacyanoferrate. In a particular embodiment, the coated hygroscopic salt is a sodium chloride particle coated with sodium aluminosilicate (E554), silicon dioxide (E551 ) and hexacyanoferrate. Fatty acid amides and/or esters may be used as a polymer lubricant. In some embodiments, the water-soluble polymer material of the present invention is substantially free of fatty acid amides or esters. The water-soluble polymer material of the present invention may include one or more optional additives. The additives may improve the processability of the polymer composition when producing the container or may improve the properties of the polymer composition used to make the polymer material of the present invention.

Thermal Stabiliser

The water-soluble polymer material described herein may include one or more thermal stabilisers. The water-soluble polymer material of the present invention may include a thermal stabiliser to improve the processing of the water-soluble polymer composition into the container of the present invention.

In some embodiments, the water-soluble polymer material described herein includes a thermal stabiliser in an amount up to and including 0.5 % weight. In preferred embodiments, the water-soluble polymer material described herein includes a thermal stabiliser in an amount up to and including 0.3 % weight.

Examples of thermal stabilisers include but are not limited to metal stearates, in particular calcium stearate.

Salt Plasticiser

The water-soluble polymer material described herein may include a salt

plasticiser. For example, the salt plasticiser may be a hygroscopic organic solvent. In preferred embodiments, the salt plasticizer is selected from the group

consisting of glycerine and propylene glycerol. Glycerine is also referred to as glycerin and glycerol. In some embodiments, the container includes the hygroscopic salt at a higher percentage by weight than the salt plasticizer. The ratio by weight of hygroscopic salt to salt plasticiser may be in the range of 1 .25:1 to 12:1 . In some

embodiments, the ratio by weight of hygroscopic salt to salt plasticiser may be in the range of 1 .25:1 to 7:1 . In preferred embodiments, the ratio by weight of hygroscopic salt to salt plasticiser may be in the range of 4:1 to 5:1 .

Polymer Plasticiser

The water-soluble polymer material described herein may include one or more polymer plasticisers. Such plasticisers may lower the melt temperature of the polymer when being extruded or molded into the container. The polymer plasticiser may be selected from the group consisting of glycerine, ethylene glycol, triethylene glycol, low molecular weight polyethylene glycols and low molecular amides. In a preferred embodiment, the polymer plasticiser is glycerine.

The polymer plasticiser may act as the salt plasticiser. For example, the water- soluble polymer material of the present invention may include glycerine. The glycerine may act as both the polymer plasticiser and salt plasticiser. Polymer Composition

The water-soluble polymer material of the container of the present invention is typically made from a polymer composition. The polymer composition can be extruded or moulded to form the polymer material of the container. The polymer composition may include the components of the polymer material and optionally additional volatile components, such as a solvent. The volatile components typically evaporate when the polymer composition is processed into the polymer material. Container Manufacture

The method of manufacture of the container body and lid of the present invention is not particularly limited. Methods of manufacturing of polymer containers are known to the skilled person.

For example, the container body may be made by extruding or moulding of a polymer compositions as described above in known ways. In particular, the container body of the present invention may be injection-moulded. The polymer compositions described herein can be produced, for example, by combining and mixing the composition components, optionally with heating.

Typically, the polymer composition described herein has a melt flow index of 10 g (per 10 minutes of duration of test) or more. Such a composition has excellent processability properties, especially for injection moulding. In some embodiments, the polymer composition described herein has a melt flow index of 20 g (per 10 minutes of duration of test) or more. In particular embodiments, polymer composition described herein has a melt flow index of 40 g (per 10 minutes of duration of test) or more. The melt flow index (MFI) is measured and compared under ISO 1 133. Typically, the MFI is tested using 5 g samples at 190 °C using a 2.16 kg weight and repeated 10 times to produce a mean result.

The present invention provides a method of making a water-soluble cleaning agent container having a rigid container body, the method comprising the step of injection-moulding a water-soluble composition into a single piece having a container base, one or more container walls extending from the container base, the container wall or walls defining a cleaning agent cavity, and one or more partition walls forming two more component compartments in the cleaning agent cavity, the composition including a water-soluble polymer and at least 15 % by weight of a hygroscopic salt based on the total weight of the polymer composition. The method may include a step of depositing cleaning agent (formed of one or more cleaning agent components) into the cleaning agent cavity of the rigid container body after injection-moulding of the rigid container body. Such a method can easily be implemented, for example, on a production line. The method may also include a step of sealing the cleaning agent cavity of the rigid container with a lid as described herein after depositing cleaning agent into the cleaning agent cavity of the rigid container body. A cleaning product of the present invention may thus be produced by a method described herein. Cleaning Product

The cleaning product of the present invention includes the water-soluble container of the present invention and a cleaning agent. The cleaning agent is typically held in the cleaning agent cavity of the container body. Cleaning Agent

The cleaning agent may be any agent for cleaning an item. In preferred

embodiments, the cleaning agent of the present invention is a laundry detergent. Laundry detergents are known per se. The laundry detergent may be a powder or liquid laundry detergent.

Use of Cleaning Product

The use of the cleaning product including the cleaning agent container and cleaning agent is not particularly limited. In preferred embodiments, the use of the cleaning product is for laundry use. The water-soluble polymer material of the container is relatively stable against moisture before use while maintaining a suitable solubility suitable for short (less than 60 minutes) and/or cool (30 °C or less) laundry wash cycles.

The preferred features of the present invention given above are equally

combinable with the other preferred features in so far as they are not alternatives. In particular, the present invention may provide a water-soluble cleaning agent container, wherein the container comprises a rigid water-soluble polymer container body having a container base and one or more container walls defining a cleaning agent cavity for holding cleaning agent, a container body inlet into the cleaning agent cavity, wherein the container body also includes a partition wall dividing the cleaning agent into one or more component compartments, wherein the container base, container wall or walls and partition wall are made of a single piece and made of a water-soluble polymer material comprising a water-soluble polymer and a hygroscopic salt, the hygroscopic salt being present in the polymer material in an amount of at least 15 % by weight based on the total weight of the polymer material, and wherein the container also includes a container lid adapted to block the inlet and seal the cleaning agent cavity, the lid being made of water-soluble polymer material comprising a water-soluble polymer and a hygroscopic salt, the hygroscopic salt being present in the polymer material in an amount of at least 15 % by weight based on the total weight of the polymer material.

Exemplary embodiments of the present invention will now be further described with reference to the accompanying figures. Figure 1 is a perspective view of 2 alternative containers of the present invention. Figure 1 A shows a container with a single compartment and a lid. Figure 1 B shows a container with two compartments.

Figure 2 shows an overhead view of three alternative containers. Figure 2A shows an overhead view of a container with two compartments. Figure 2B shows an overhead view of a container with three compartments. Figure 2C shows an overhead view of a container with four compartments.

In more detail, Figure 1A shows a container 1 of the present invention. The container body 2 has a flat circular base 3 and a container wall 4 extending from the base 3. The container wall 4 is a truncated hollow cone defining a cleaning agent cavity 5 for accommodating the cleaning agent. The upper rim 6 of the container wall 4 forms an inlet 7 into the cleaning agent cavity 5. The container 1 also includes a flat circular lid 8. The lid is a size and shape that is complementary to the inlet 7. As a result, the lid 8 fits into the inlet 7 to seal the container body 2. The container body 2 includes a lid lip 9 protruding from an interior surface of the container wall 4. The lid lip 9 is positioned about the thickness of the lid 8 from the upper rim of the container wall 4. The lid lip 9 provides a resting platform for the lid 8 when combined with the container body 4. The container 1 (container body 4 and lid 8) is injection moulded and made of a material containing polyvinyl alcohol with a hygroscopic salt.

Figure 1 B shows an alternative container 21 of the present invention. The container body 22 has a flat circular base 23 and a container wall 24 extending from the base 23. The container wall 24 is a hollow cylinder defining a cleaning agent cavity 25 for accommodating the cleaning agent. The upper rim 26 of the container wall 24 forms an inlet 27 into the cleaning agent cavity 25. The container body 22 also includes a cavity partition wall 28 bisecting the cleaning agent cavity 25. The partition wall 28 extends vertically from the flat base 23 to the inlet 27 to form two separate compartments 29, 30 for holding cleaning agent components and/or other components. The container body 24 (container base 23, container wall 24 and partition wall 28) is injection moulded into a single piece and made of a material containing polyvinyl alcohol with a hygroscopic salt.

Figures 2A, 2B and 2C show an overhead view of containers of the present invention. Figure 2A is an overhead view of the container of Figure 1 B. Figure 2B shows a variation of the container of Figure 1 B, whereby the container of Figure 2B has three partition walls 41 , 42, 43 forming three compartments 51 , 52, 53 within the cleaning agent cavity. Figure 2C shows a variation of the container of Figure 1 B, whereby the container of Figure 2C has four partition walls 61 , 62, 63, 64 forming four compartments 71 , 72, 73, 74 within the cleaning agent cavity. The containers of Figures 2A, 2B and 2C are injection moulded into a single piece and made of a material containing polyvinyl alcohol with a hygroscopic salt.

EXAMPLES

Methods

Water-soluble polymer composition components were mixed together in a bell tub, low shear mixer for 3 minutes. The mix was then fed into a compounder via a screw and formed into pellets via an adapted calendaring process. The adapted calendaring process causes partial or complete melting of the PCA as a result of the frictional shear as it is passed between the die and the runner. As a result, agglomeration occurred before extrusion through the die.

The temperature of the pre-extrudate varied from 1 10 °C to 140 °C. The formed pellets were places in a tray polymer dryer for 3 hours at 90 °C.

The resulting pellets can be used to make the containers of the present invention by, for example, injection moulding. Moulding was performed using a BOY 50 tonne moulding process automatic mode with a cycle time of 7-10 seconds using a mould with a hot runner system at 180 °C to 200 °C. The screw temperature profile from the hopper to the tip was 160 °C, 170 °C, 180 °C, 180-190 °C.

Alternatively, moulding can be performed in a BOY 50 tonne moulding process in automatic mode with a cycle time of 20 seconds using a mould with a cold runner system. The screw temperature profile from the hopper to the tip was 160 °C, 170 °C, 180 °C, 180 °C, 220 °C.

Water-soluble polymer compositions

Water-soluble polymer composition components were mixed together in the following weight percentages to form water-soluble polymer compositions. Table 1 shows examples using hydrolysed PVA as the water-soluble polymer, glycerol as a plasticizer, NaCI acts as a hygroscopic salt and calcium stearate as the thermal stabiliser. 98% hydrolysed PVA was used in Example 1 , and 88% hydrolysed PVA was used in Examples 2 to 6.

Table 1

Table 2 shows Examples 5 to 7, which are similar to Examples 2 to 4, except that propylene glycol is used as the plasticizer.

Table 2

Table 3 shows a water-soluble polymer composition having sodium citrate as the hygroscopic salt. Table 3

Many of the compositions of Examples 1 to 10 have a melt flow index 10 g or more per 10 minutes of test duration (as tested and compared for MFI under ISO 1 133 using 5 g samples tested at 190 C using a 2.16 kg weight and repeated 10 times to produce a mean result). The polymer compositions show good properties for moulding and/or extruding.

Injection Moulding of Containers

The above compositions can be moulded using a BOY 50 tonne moulding press in automatic mode, either with a cycle time of 7-10 seconds using a mould with a hot runner system at 180 to 200 °C, or with a cycle time of 20 seconds using a mould with a cold runner system. The water-soluble polymer compositions were moulded into a single injected- moulded container having a circular flat base and a cylindrical container wall extending from the flat base to form the container wall and define a cleaning agent holding cavity. Some of the containers included a single partition wall dividing the cavity. The volume of equal size and the partition wall formed a single piece with the flat base and cylindrical container wall.

Lids to insert into the inlet were also injection moulded using the water-soluble polymer compositions. The lids are flat circular pieces with a circumference complementary to the circular inlet of created by the upper rim of the cylindrical wall. In some lids, the lid also has a rim protruding from the flat circular surface to insert into and abut against the interior cylindrical container wall. Moisture Stability Tests

The moulded containers were tested for their stability against moisture. Wet Hands Test

The moulded containers of the present invention were removed from a box with other containers using wet hands and placed back in the box. The test mimics situations where a user may inadvertently wet the container prior to use by handling another container with wet hands. At 5 minutes after handling of the containers, the containers showed a change in visible appearance (e.g. tarnishing and/or discolouration) on parts where the container had been exposed to moisture. The container remained intact and usable. At 1 hour after handling of the containers, adhesion between containers occurred at abutting container surfaces. However, containers could be easily separated without damaging the integrity of the container base, wall or lid.

At 4 days after handling of the containers, there was no further visible effect on the containers (from that described after 1 hour).

A commercially available laundry product having a thin water-soluble PVOH polymer film casing enclosing a laundry gel was tested in the same way. At 20 seconds after handling of the laundry product, part of the thin film had dissolved resulting in loss of the laundry gel. The majority of the laundry gel had drained from the thin film casing after 2 minutes resulting in an unusable product.

Heat and Humidity Tests

Injection-moulded containers having 2 compartments (i.e. with a single partition wall) were filled with liquid detergent compositions. The containers were fitted with a lid to seal the container and detergent composition (closed containers. The containers were then placed in environments with varying temperature and relative humidity. The specific environments tested were: ambient temperature and 53% relative humidity (RH); 5 °C and 90 % RH; 25 °C and 38 % RH; 37 °C and 70 % RH; and 50 °C and 15 % RH.

The containers were regularly checked for damage to the container that would cause leakage of the liquid detergent compositions either out of the container or between compartments. In other words, a failure was recorded if the integrity of the base, cylindrical container wall or partition wall was breached (resulting in mixing or loss of the detergent compositions).

All the containers were stable after 1 1 weeks of testing under each environmental condition. Dissolution Test

The containers of the present invention were tested to show the time taken to completely dissolve the container in water at various temperatures. The time taken to complete dissolve the containers at each temperature is shown in Table 5.

Table 5

At 30 °C, containers of the present invention dissolved in just 22 minutes. In addition, the containers of the present invention could be dissolved at 0 °C in 40 minutes with agitation. Similar dissolution times may be obtained when the containers of the present invention contain a powder laundry detergent.

Accordingly, the containers of the present invention show excellent stability with respect to moisture while maintaining an excellent dissolution profile. The containers of the present invention are therefore particularly suited as laundry detergent containers as they can be used in short time (60 minutes or less) and/or low temperature (30 °C or less) washing cycles.