GB2390998A

GB2390998A - Use of a hygroscopic compound in the bonding of water soluble sheets

Info

Publication number: GB2390998A
Application number: GB0216945A
Authority: GB
Inventors: Giorgio Franzolin
Original assignee: Reckitt Benckiser NV
Current assignee: Reckitt Benckiser NV
Priority date: 2002-07-20
Filing date: 2002-07-20
Publication date: 2004-01-28
Also published as: WO2004009335A1; AU2003244863A1; GB0216945D0

Abstract

A process comprises the sealing of a water soluble sheet to a water soluble member, such as a second water soluble sheet, in which a hygroscopic compound is applied to at least one of the sheet and member, before they are bought together. Also disclosed in a process consistent with the above, in which a laminate of water soluble sheets is formed. The hygroscopic compound may be such as a polyhydric alcohol, or polyol, such as a mono / di / tri hydric alcohol, such as glycerol. The process may comprise heat sealing. The sealed sheets may then be used in the manufacture of a water soluble bag or sachet.

Description

SE"ING WATER SOLUBLE POLLERS

The present invention relates to a process for heat sealing a watersoluble film to a water soluble member which is 5 especially suitable for use, for example, in the preparation of water-soluble containers and laminate films.

It is known to package chemical compositions, particularly those which may be of a hazardous or irritant nature, in water 10 soluble films which are heat sealed together. Such containers can simply be added to water in order to dissolve or disperse the contents of the container into the water. For example, WO 89/12587 discloses a package which comprises an envelope of a water soluble material which comprises a flexible wall and a 15 water-soluble heat seal. The package may contain an organic liquid comprising, for example, a pesticide, fungicide, insecticide or herbicide.

Wo 92/17382 discloses a package containing an agrochemical 20 comprising a first sheet of non-planar water-soluble or water-

dispersible material and a second sheet of water-soluble or waterdispersible material superposed on the first sheet and sealed to it.

25 It is desirable for the seal between two water soluble components, such as two films, to be strong. A weak seal may fail easily. This may cause problems if the components form a container which encases a composition which could disperse in the incorrect environment, such as in the box they are stored 30 in before use. This could render the entire batch of containers unsuitable for use.

Laminated films are known to be suitable for use in packaging.

In certain instances it may be advantageous to use a laminate of two films. For example, GB-A-2,244,258 teaches that a laminated film may be used to package a hazardous chemical 5 dissolved or dispersed in a liquid or gel. While a single film may have pinholes, the two films in a laminate are unlikely to have pinholes which coincide. Thus the risk of leakage is reduced by using a laminated film. According to GB-A-2,244,258 the layers of the laminated film are desirably made by 10 different techniques such as extrusion or casting, since films made by different methods may have advantageous properties.

However, laminated films produced using different techniques have the disadvantage that they are expensive to produce.

15 When using a film for packaging purposes, it may be appropriate to use a reasonably thick film, particularly when the film is thermoformed because the thickness of the film is reduced in places during the thermoforming process. However, it is difficult to produce such a film by the standard blowing or 20 casting process. Films produced by these processes lack at least one of uniform thickness, moisture content and consistency, and may also have a large proportion of fish eyes.

The present invention provides a process for sealing a water 25 soluble film to a water soluble member (preferably the water soluble member is a second water-soluble film), wherein a composition comprising at least one humectant and/or hydroscopic compound is applied to at least one of the surfaces of said film and said member before said surfaces are brought 30 together.

Alternatively the invention provides a process for

laminating two water-soluble films wherein a composition comprising at least one hydroscopic compound is applied to at least one of the surfaces of one of the films and said films are brought together.

Preferred hydroscopic materials are mono- or di-hydric and polyhydric alcohols as defined herein. Conversely, preferred mono- or di-hydric and polyhydric alcohols for use in the first or second aspects herein are hydroscopic.

10 - If a polyhydric alcohol is present in a composition of the invention it suitably has 3-4 hydroxyl groups, and 2-8 carbon atoms. It is preferably non-aromatic. More preferably it is aliphatic. Specially preferred are tri-hydric alcohols, 15 preferably having 3-6 carbon atoms. Glycerol is especially preferred. If a mono-or di-hydric (preferably dihydric) alcohol used in the invention has from 1 to 8 carbon atoms, preferably from 20 1 to 6 carbon atoms. It is preferably non-aromatic. More preferably it is aliphatic. It may be linear or branched.

Especially preferred is propan-1,2-diol.

In terms of ease of application and use it is preferred 25 that the hydroscopic material is in the form of a thickened composition, or is itself has a viscosity higher than water (such as glycerol). Preferred viscosity range is from 200 to 3,000 cps, as measure in a Brookfield, at a temp. of 25 C and a

no. 3 spindle.

The amount of hydroscopic material that is applied is between 2 to 20 emu, preferably from 5 to 12 Emu.

In preferred embodiments the composition may contain a mono- or di-hydric alcohol in addition to a said polyhydric alcohol. In an alternative preferred embodiment the composition 5 comprises a polyhydric alcohol. In such embodiments the monohydric alcohol is suitably present in an amount of at least 0.1% wt. preferably at least 1% wt. and most preferably at least 2.5% wt. of the composition. In such embodiments the monohydric alcohol is preferably present in an amount up to 10% 10 wt. more preferably up to 8% wt. and most preferably up to 5% wt. of the composition.

When any composition of the invention, whether it contains a polyhydric alcohol as the only alcohol or, as is preferred, 15 also a monohydric alcohol, the polyhydric alcohol preferably comprises up to 90% wt of the composition, and more preferably up to 80% wt of the composition. Most preferably it comprises up to 50% wt of the composition. In such embodiments the polyhydric alcohol suitably provides at least 5% wt of the 20 composition, and preferably at least 10% wt of the composition.

It will be appreciated that a certain amounts of water may be present in the composition.

25 It has surprisingly been discovered that a seal formed by the process of the present invention is stronger than a seal formed under the same conditions but without the composition being applied prior to sealing. In addition we have found that the application of the composition provides excellent aestheic 30 properties in providing no bubbles, fish eyes, cracks.

Where heat is applied to aid sealing then it is possible to carry out heat sealing at the same temperature as previously used without the composition, in which case the heat seal is stronger. It is also possible to reduce the heat sealing 5 temperature when using the composition and achieve a similar seal strength, which may consequently allow for a greater throughput of heat sealed components since less time may be required in the heat sealing step. The use of the composition may also facilitate the heat sealing of components for which a 10 lower heat sealing temperature is desirable.

It has also surprisingly been found that the process of the present invention reduces the crystallinity of the heat seal, thus increasing the dissolution speed of the seal area.

A preferred use of the composition is in the lamination of two watersoluble films. The lamination of the two films (a film stack) may be carried out "off-line", i.e. where a laminated film is produced and rolled onto a reel for later 20 use, or as an "on-line" process, i.e. where the film stack is fed into a forming machine and is laminated as part of the manufacturing process.

The film stack is then heated during a thermoforming process 25 to adhere the layers to each other to form a laminated, thermoformed film. Such a process has the advantage that a separate heating step is not required to form the laminated film. Instead the laminated film is formed during one of the necessary steps in a thermoforming process. For example, the 30 laminate may be formed by the action of heat and pressure or vacuum from the heating plate or the forming mould, or a combination of the two, during a thermoforming process. It is,

however, desirable for the lamination to occur while the film stack is being drawn down or blown down into the mould. Thus, for example, the film stack is heated to a thermoforming temperature using a normal thermoforming heater plate assembly 5 and then drawn down under vacuum or blown down under pressure into the mould. The thermoforming temperature, pressure or vacuum and dwell time depend on the polymer or mixture of polymers being used.

10 In the process of the present invention, a modified version of a standard heat sealing process is used. Heat sealing is a well known technique and is discussed, for example, in WO 89/12587 and WO 92/17382 and in James L. Throne "Understanding Thermoforming" published by Carl Hanser Verlag, 1999. In such 15 a process, a film is sealed to a member by placing the film and the member next to each other, applying heat to the side of the film which is not in contact with the member for a sufficient duration such that the surface of the film which is in contact with the member becomes tacky, and applying pressure to seal 20 the film to the member. In order to carry out heat sealing, it is necessary that the film is sufficiently thin to conduct heat to the surface which is to be sealed. This places some practical limitation on the thickness and conductivity of the film. In the context of the present invention, a film is 25 defined as having any thickness such that it can be heat sealed. Apart from this, it can have any other characteristics. For example it can be rigid or flexible. In general the film has a thickness of from 20 to 160pm, preferably from 40 to 100pm, more preferably from 55 to 80pm 30 for PVOH. These thicknesses also apply for other polymers, although other thicknesses may also be used depending on the conductivity, plasticity and Tg of the film

The member may have any thickness, shape or form since its thickness is not limited by the requirement that it must be heat sealable. It may, for example, be rigid or flexible. It 5 may, for example, have a thickness in the area of heat sealing of from 15pm to 30mm, preferably 30pm to 25mm, more preferably 80pm to 20mm Preferably, however, the member is also in the form of a film. If the member is in the form of a film, it may have the same thickness as the film to which it is heat sealed, 10 or a different thickness. It may also be in the form of a three-dimensional moulding.

The member can be integral with the film before they are sealed together. For example the film and the member can be different 15 parts of a single film which is heat sealed to itself.

The film and member may comprise any water soluble (which term is taken to include water dispersible) polymer which can be heat sealed. The film and the member may be made of the same 20 or different polymers. Examples of water-soluble polymers are poly(vinyl alcohol) (PVOH), cellulose derivatives such as hydroxypropyl methyl cellulose (HPMC), gelatin, poly(vinylpyrrolidone), poly(acrylic acid) or an ester thereof or poly(maleic acid) or an ester thereof. Copolymers of any of 25 these polymers may also be used.

An example of a preferred PVOH is ethoxylated PVOH. The PVOH may be partially or fully alcoholized or hydrolyzed. For example it may be from 40 to 100%, preferably from 70 to 92%, 30 more preferably about 88% or about 92%, alcoholized or hydrolyzed. The degree of hydrolysis is known to influence the temperature at which the PVOH starts to dissolve in water. 88%

hydrolysis corresponds to a PVOH soluble in cold (ie room temperature) water, whereas 92% hydrolysis corresponds to a PVoH soluble in warm water. A preferred PVOH which can be further processed, for example by forming into a film or by 5 moulding such as injection moulding, is sold in the form of granules under the name CP1210T05 by Soltec Developpement SA of Paris, France. By choosing an appropriate polymer it is possible to ensure that the water-soluble polymer dissolves at a desired temperature. Thus the film and/or the member may be 10 cold water (20 C) soluble, but may be insoluble in cold water and only become soluble in warm or hot water having a temperature of, for example, 30 C, 40 C, 50 C or even 60 C.

Advantageously the film and/or member may be substantially 15 anhydrous, that is contain less than 5 wt' water, preferably less than 2 wt% water. We have found that such films and members are less liable to shrink on heating, for example during a thermoforming step.

20 Desirably the water-soluble film and/or member consist essentially of, or consist of, the water-soluble polymer composition. It is possible for suitable additives such as plasticizers, lubricants and colouring agents to be added.

Components which modify the properties of the polymer may also 25 be added. 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 polymer is therefore generally used in an amount of from 75 to 84.5 wet, based on the total amount of the moulding composition.

30 Suitable plasticizers 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. 5 It is also possible to include one or more particulate solids in the moulding composition, especially if the member is injection moulded in order to accelerate the rate of dissolution of the member or film. Dissolution of the solid in water is sufficient to cause an acceleration in the break-up of 10 the member or film, particularly if a gas is generated.

Examples of such solids are alkali and alkaline earth metal, such as sodium, potassium, magnesium and calcium, bicarbonate and carbonate, in conjunction with an acid.

15 Suitable acids are, for example acidic substances having carboxylic or sulfonic acid groups or salts thereof. Examples are cinnamic, tartaric, mandelic, fumaric, maleic, malic, palmoic, citric and naphthalene disulfonic acids, as free acids or as their salts, for example with alkali or alkaline earth 20 metals.

The composition used in the process of the present invention is applied to at least one of the surfaces of said film and member before said surfaces are heat sealed together. Preferably it 25 is applied to one surface. If the composition is applied only to one surface, it is preferred that it is applied to the surface which is not heated. Thus, in this case, it is applied to the member since it is usually the film which is heated.

This ensures that it is the colder or thicker part which is 30 softened or made more deformable by the application of the aqueous composition. However, for commercial reasons, and in particular having regard to the necessary modification of

existing heat sealing machines, it is still satisfactory to apply the composition to the film.

The composition can be applied only to the area which is to be 5 heat sealed or over a smaller or larger area of the film and/or member. The composition can be applied by any means. The composition can be applied, for example, by directly coating it on the 10 surface of the film and/or member. Coating can be carried out by any process. For example the composition can be sprayed directly on the surface. It may also be applied by a roller or printing process, such as by a transfer printing process, for example a photogravure, litho, flexo, silk screen or recess 15 printing process or by an inkjet printer. A transfer printing process uses a template which may be, for example, engraved or contain a lithographic image. The aqueous composition is coated onto the printing plate surface. The excess composition may be removed, if appropriate, for example using a doctor 20 blade. The plate is then placed on top of the target to transfer the aqueous composition to the target.

Preferably the temperature of the composition is from 4 to 60 C, more preferably 10 to 40 C, even more preferably from 15 25 to 30 C. Most preferably the temperature of the composition is about room temperature (21 C) for ease of handling.

The composition is one which, when applied to the water-soluble film or member, penetrates into the film or member thus 30 increasing its plasticity. It may also render the film or member sticky or tacky, although this is not essential. The composition may, however, comprise other components such as a

water soluble polymer. Suitable water soluble polymers are discussed above. Generally the water soluble polymer is the same as that constituting the water soluble film and/or member.

The composition may also comprise components which increase the 5 surface tension or ionic strength of the composition to control the penetration of the composition into the film or member.

For example it may comprise a salt such as an alkali metal salt, for example, lithium or sodium chloride or sodium citrate. Such salts are generally used in an amount of less 10 than 1 wt%, although they may be used in larger amounts. For example the aqueous composition may be in the form of a saturated solution of a salt. In the case of lithium chloride this amounts to about 25 wt% lithium chloride in water. An increase in the surface tension can also be achieved, for 15 example, by the addition of a thickener or gelling agent.

Again, such components are generally used in an amount of less than 1 wt%, although they may be used in larger amounts.

The composition is applied to the surface of the film and/or 20 member before the film and the member are contacted prior to heat sealing. The film and the member may be contacted immediately after the composition is applied. Desirably, however, the composition is allowed to act on the water soluble film or member for a short while before the film and the member 25 are contacted, for example from 0.5 to 10 second=, preferably from 1 to 5 seconds, more preferably from 1.5 to 2.5 seconds.

The film and the member are then heat sealed together in a known manner. Thus the film and the member are held together 30 by means of a pressure plate pushing down against the parts of the combination which need to be heat sealed, for example in a direction towards the member. The plate may be flat or may

have, for example, a textured surface such as stipples. Heat is generally applied to the side of the film which is opposite the side which is in contact to the member. Heat is generally applied to the film by a heating the pressure plate. However, 5 it is also possible to use, for example, other heating means such as contact heaters or radial heaters. The sealing conditions depend on the machine and material used. Generally the sealing temperature is from 100 to 180 C. The pressure is usually from 100 to 500 kPa (1 to 5 bar). The dwell time is 10 generally from 1.3 to 2. 5 seconds.

The water soluble member is desirably in the form such that, when the film is sealed to it, there is provided a water-

soluble container containing at least one composition. Thus 15 the member can, for example, be in the form of a film or sheet having a pocket therein. The pocket can be produced by a moulding technique, for example thermoforming, injection moulding or blow moulding. If the member is integral with the film before they are sealed together, and in the form of a 20 single film which is heat sealed to itself, a vertical form fill sealing process can be carried out to provide envelopes containing a composition. Pillow packs can also be produced from two different films.

25 The member can also be in the form of a more rigid moulding, for example produced by injection moulding or blow moulding.

Such a moulding can be in the form of an open container which is filled with at least one composition and then sealed with at least one film by the process of the present invention. Such 30 containers are desirable, for example, in WO 01/36,290.

For example the container may be a water-soluble, injection-

moulded container comprising at least two compartments, a first compartment containing a first composition and having a first opening closed by a first film and a second compartment 5 containing a second composition and having a second opening closed by a second film, wherein the first film and the second film have the same different water dissolution characteristics and neither, one or both dissolve before the walls of the container. One, some or all of the films may be heat sealed by 10 the process of the present invention.

An injection moulded member forming a container has walls which generally have a thickness such that the container is rigid.

For example, the outside walls and any inside walls may 15 independently have a thickness of greater than 100pm, for example greater than 150pm or greater than 200pm, 300pm, 400pm, 500pm, 750pm or lmm. Typically the thicknesses are from 200pm to 1,000pm, preferably 300pm to 500pm.

20 The container, whether made by injection moulding, thermoforming or any other process, may have any shape, but suitably is generally cuboid. The top wall may be formed by the sealing film and the side walls and base wall may be formed by the thermoformed or injection moulded part of the container, 25 hereinafter sometimes referred to as the receptacle part.

The film may be produced by any process, for example by extrusion and blowing or by casting. The film may be unoriented, monoaxially oriented or biaxially oriented. If the 30 layers in the film are oriented, they usually have the same orientation, although their planes of orientation may be different if desired.

The layers in a laminate may be the same or different. Thus they may each comprise the same polymer or a different polymer.

If it is desired to have a water-soluble laminated film, each 5 of the layers should be water-soluble.

The thickness of the film used to produce the pocket is preferably 40 to 300 m, more preferably 80 to 200 m, especially 100 to 160 m, more especially 100 to 150 Am and 10 most especially 120 to 150 m.

The pocket may be formed by, for example, vacuum forming or thermoforming. For example, in a thermoforming process the film may be drawn down or blown down into a mould. Thus, for 15 example, the film is heated to the thermoforming temperature using a thermoforming heater plate assembly, and then drawn down under vacuum or blown down under pressure into the mould.

One skilled in the art can choose an appropriate temperature, pressure or vacuum and dwell time to achieve an appropriate 20 pocket. The amount of vacuum or pressure and the thermoforming temperature used depend on the thickness and porosity of the film and on the polymer or mixture of polymers being used.

Thermoforming of PVOH films is known and described in, for example, WO 00/55045.

A suitable forming temperature for PVOH or ethoxylated PVOH is, for example, from 90 to 130 C, especially 90 to 120 C. A suitable forming pressure is, for example, 69 to 138kPa (10 to 20 p.s.i.), especially 83 to 117 kPa (12 to 17 p.s.i.). A 30 suitable forming vacuum is 0 to 4 kPa (0 to 40 mbar), especially 0 to 2 kPa (0 to 20 mbar). A suitable dwell time

is, for example, 0.4 to 2.5 seconds, especially 2 to 2.5 seconds. While desirably conditions chosen within the above ranges, it 5 is possible to use one or more of these parameters outside the above ranges, although it may be necessary to compensate by changing the values of the other two parameters.

After the pocket has been filled with the desired composition, lO a film is placed on top of the filled pocket and across the sealing portion, and the film are heat sealed together at the sealing portion by the process of the present invention. This film may be a single-layered film but is desirably laminated to reduce the possibility of pinholes allowing leakage through the 15 film. The film may be the same or different as the film forming the pocket.

Desirably the covering film has a thickness which is less than that of the film used for forming a pocket because it would not 20 generally be stretched so localized thinning of the sheet will not occur. It is also desirable to have a thickness which is less than that of the film used to form a pocket to ensure a sufficient heat transfer through the film to soften the base web because heat sealing is used.

The thickness of the covering film is generally from 20 to 160 m, preferably from 40 to 100 m, such as 40 to 80 Em or 50 to 60 m. 30 The sealing films generally dissolve in water before the receptacle part of the container. The films therefore generally have thicknesses which are less than the wall

- thickness of the receptacle part. In general, the sealing part dissolves in water (at least to the extent of allowing the composition in the receptacle part to be partly or completely dissolved by the water) at 40 C in less than 5 minutes, 5 preferably less than 2 minute.

It is possible for one or more of the sealing films to have incorporated therein a composition. Thus, for example, one or more of the films can themselves contain compositions formed in 10 the films by a previous operation such as thermoforming or vertical form fill sealing.

If the containers contain two or more compositions, they can have a particularly attractive appearance since the 15 compositions, which may be identical or different, may be held in a fixed position in relation to each other. The compositions can be easily differentiated to accentuate their difference. For example, the compositions can have a different physical appearance, or can be coloured differently.

Thus the composition within the container, or an individual compartment, need not be uniform. For example, during manufacture the container or compartment could first be fed with a gettable composition, for example, a gel, and then with 25 a different composition. The first composition could dissolve slowly in the washing process so as to deliver its charge over a long period within the washing process. This might be useful, for example, to provide an immediate, delayed or sustained delivery of an component such as a softening agent.

The compositions in each compartment may be the same or different. If they are different, they may, nevertheless, have one or more individual components in common.

5 The composition(s) which can be held in the container, or in each compartment of the container may independently be a fabric care, surface care or dishwashing composition. Thus, for example, they may be a dishwashing, water-softening, laundry or detergent composition, or a rinse aid. Such compositions may 10 be suitable for use in a domestic washing machine. The compositions may also independently be a disinfectant, antibacterial or antiseptic composition, or a refill composition for a trigger-type spray. Such compositions are generally packaged in total amounts of from 5 to 100 g, 15 especially from 15 to 40 g. For example, a laundry composition may weigh from 15 to dog, a dishwashing composition may weigh from 15 to 30 g and a water-softening composition may weigh from 15 to 40 g.

20 The composition(s) may be a solid. For example, it may be a particulate or granulated solid, or a tablet. It may also be a liquid, which may be thickened or gelled if desired. The liquid composition may be non-aqueous (i.e. anhydrous) or aqueous, for example comprising less than or more than 5 wt% 25 total or free water. An anhydrous composition generally contains less than 1 ate, preferably less than o.s wt% water.

The composition may have more than one phase. For example it may comprise an aqueous composition and a liquid composition which is immiscible with the aqueous composition. It may also 30 comprise a liquid composition and a separate solid composition, for example in the form of a ball, or pill or speckles. The liquid composition may be thickened or gelled.

If the composition is an aqueous liquid having a relatively high water content, for example above 5 wt% water, it may be necessary to take steps to ensure that the liquid does not 5 attack the water-soluble polymer if it is soluble in cold water, or water up to a temperature of, say, 35 C.Steps may be taken to treat the inside surfaces of the container, for example by coating it with agents such as PVdC (poly(vinylidene dichloride)) or PTFE (polytetrafluoroethylene), or to adapt the 10 composition to ensure it does not dissolve the polymer. For example, it has been found that ensuring the composition has a high ionic strength or contains an agent which minimizes water loss through the walls of the container will prevent the composition form dissolving the polymer from the inside. This 15 is described in more detail in EP-A-518,689 and WO 97/27,743.

The containers may have any desired shape. For example the container can have a irregular or regular geometrical shape such as a cube, cuboid, pyramid, dodecahedron or cylinder. The 20 cylinder may have any desired cross-section, such as a circular, triangular or square cross-section.

If the container has two or more compartments, the individual compartments need not necessarily be regular or identical. For 25 example, if the final container has a cuboid shape, the individual compartments may have different sizes to accommodate different quantities of compositions.

The compartments may have the same or different size and/or 30 shape. In general, if it is desired to have compartments containing different quantities of components, the compartments

have volume ratios of from 2:1 to 20:1, especially from 4:1 to 10:1. The container may also have a hook portion so that it can be 5 hung, for example, from an appropriate place inside a dishwashing machine.

The containers produced by the process of the present invention may, if desired, have a maximum dimension of 5 cm, excluding 10 any flanges. For example, a container may have a length of 1 to 5 cm, especially 3.5 to 4. 5 cm, a width of 1.5 to 3.5 cm, especially 2 to 3 cm, and a height of 1 to 2 cm, especially 1.25 to 1.75 cm.

15 If more than one composition is present, the compositions may be appropriately chosen depending on the desired use of the article. If the article is for use in laundry washing, the primary 20 composition may comprise, for example, a detergent, and the secondary composition may comprise a bleach, stain remover, water-softener, enzyme or fabric conditioner. The article is adapted to release the compositions at different times during the laundry wash. For example, a bleach or fabric conditioner 25 is generally released at the end of a wash, and a water-

softener is generally released at the start of a wash. An enzyme may be released at the start or the end of a wash.

If the article is for use as a fabric conditioner, the primary 30 composition may comprise a fabric conditioner and the secondary component may comprise an enzyme which is released before or after the fabric conditioner in a rinse cycle.

If the article is for use in dish washing the primary composition may comprise a detergent and the secondary composition may comprise a watersoftener, salt, enzyme, rinse 5 aid, bleach or bleach activator. The article is adapted to release the compositions at different times during the laundry wash. For example, a rinse aid, bleach or bleach activator is generally released at the end of a wash, and a water-softener, salt or enzyme is generally released at the start of a wash.

Examples of surface care compositions are those used in the field of surface care, for example to clean, treat or polish a

surface. Suitable surfaces are, for example, household surfaces such as worktops, as well as surfaces of sanitary 15 ware, such as sinks, basins and lavatories.

The ingredients of each composition depend on the use of the composition. Thus, for example, the composition may contain surface active agents such as an anionic, on-ionic, cationic, amphoteric or zwitterionic surface active agents or mixtures 20 thereof.

Examples of anionic surfactants are straight-chained or branched alkyl sulfates and alkyl polyalkoxylated sulfates, also known as alkyl ether sulfates. Such surfactants may be 25 produced by the sulfation of higher C8-C20 fatty alcohols.

Examples of primary alkyl sulfate surfactants are those of formula: ROSO3M+

wherein R is a linear C8-C20 hydrocarbyl group and M is a water 30 solubilising cation. Preferably R is Cl0-Cl6 alkyl, for example C12-Cl4, and M is alkali metal such as lithium, sodium or potassium.

Examples of secondary alkyl sulfate surfactants are those which have the sulfate moiety on a "backbone" of the molecule, for example those of formula: 5 CH2 ( CH2) n ( CHOSO3 M) ( CH2) mCH3 wherein m and n are independently 2 or more, the sum of m+n typically being 6 to 20, for example 9 to 15 and M is a water solubilising cation such as lithium, sodium or potassium.

10 Especially preferred secondary alkyl sulfates are the (2,3) alkyl sulfate surfactants of formulae: CH2 (CH2) x (CHOSO3-M+) CH3 and CH3 ( CH2) x ( CHOSO3 -M+) CH2CH3 for the 2-sulfate and 3-sulfate, respectively. In these 15 formulae x is at least 4, for example 6 to 20, preferably 10 to 16. M is cation, such as an alkali metal, for example lithium, sodium or potassium.

Examples of alkoxylated alkyl sulfates are ethoxylated alkyl sulfates of the formula: 20 RO ( C2H4O) nSO3 -M+ wherein R is a C8-C20 alkyl group, preferably C1O-Cl8 such as a Cl2-Cl6, n is at least 1, for example from 1 to 20, preferably 1 to 15, especially 1 to 6, and M is a salt-forming cation such as lithium, sodium, potassium, ammonium, alkylammonium or 25 alkanolammonium. These compounds can provide especially desirable fabric cleaning performance benefits when used in combination with alkyl sulfates.

The alkyl sulfates and alkyl ether sulfates will generally be 30 used in the form of mixtures comprising varying alkyl chain lengths and, if present, varying degrees of alkoxylation.

Other anionic surfactants which may be employed are salts of fatty acids, for example Ca-C18 fatty acids, especially the sodium or potassium salts, and alkyl, for example C-C18, benzene sulfonates.

Examples of non-ionic surfactants are fatty acid alkoxylates, such as fatty acid ethoxylates, especially those of formula: R (C2H4O) nOH wherein R is a straight or branched C8-C16 alkyl group, 10 preferably a C, -Cl5, for example C10-Cl4, alkyl group and n is at least 1, for example from 1 to 16, preferably 2 to 12, more preferably 3 to 10.

The alkoxylated fatty alcohol non-ionic surfactant will 15 frequently have a hydrophilic-lipophilic balance (HLB) which ranges from 3 to 17, more preferably from 6 to 15, most preferably from 10 to 15.

Examples of fatty alcohol ethoxylates are those made from 20 alcohols of 12 to 15 carbon atoms and which contain about 7 moles of ethylene oxide. Such materials are commercially marketed under the trademarks Neodol 25-7 and Neodol 23-6.5 by Shell Chemical Company. Other useful Neodols include Neodol 1-

5, an ethoxylated fatty alcohol averaging 11 carbon atoms in 25 its alkyl chain with about 5 moles of ethylene oxide; Neodol 23-9, an ethoxylated primary Cl2-Cl3 alcohol having about 9 moles of ethylene oxide; and Neodol 91-10, an ethoxylated C9-

primary alcohol having about 10 moles of ethylene oxide.

30 Alcohol ethoxylates of this type have also been marketed by Shell Chemical Company under the Dobanol trademark. Dobanol 91-5 is an ethoxylated C,-Cll fatty alcohol with an average of 5

moles ethylene oxide and Dobanol 25-7 is an ethoxylated C12-Cl5 fatty alcohol with an average of 7 moles of ethylene oxide per mole of fatty alcohol.

5 Other examples of suitable ethoxylated alcohol non-ionic surfactants include Tergitol 15-S-7 and Tergitol 15-S-9, both of which are linear secondary alcohol ethoxylates available from Union Carbide Corporation. Tergitol 15-S-7 is a mixed ethoxylated product of a Cll-Cl5 linear secondary alkanol with 7 10 moles of ethylene oxide and Tergitol 15-S-9 is the same but with 9 moles of ethylene oxide.

Other suitable alcohol ethoxylated non-ionic surfactants are Neodol 45-11, which is a similar ethylene oxide condensation 15 products of a fatty alcohol having 14-15 carbon atoms and the number of ethylene oxide groups per mole being about 11. Such products are also available from Shell Chemical Company.

Further non-ionic surfactants are, for example, Cl0-Cl8 alkyl 20 polyglycosides, such s Cl2-Cl6 alkyl polyglycosides, especially the polyglucosides. These are especially useful when high foaming compositions are desired. Further surfactants are polyhydroxy fatty acid amides, such as C10-Cl N-(3-

methoxypropyl) glycamides and ethylene oxide-propylene oxide 25 block polymers of the Pluronic type.

Examples of cationic surfactants are those of the quaternary ammonium type.

30 The total content of surfactants in the composition is desirably 60 to 95 wt%, especially 75 to 90 wt%. Desirably an anionic surfactant is present in an amount of 50 to 75 wt%, the

on-ionic surfactant is present in an amount of 5 to 20 wt%, and/or the cationic surfactant is present in an amount of from 0 to 20 wt%. The amounts are based on the total solids content of the composition, i.e. excluding any solvent which may be 5 present.

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

10 Such enzymes are commercially available and sold, for example, under the registered trade marks Esperesc, Alcalasc and Savinasc by Nova Industries A/S and Maxatasc by International Biosynthetics, Inc. Desirably the enzymes are present in the composition in an amount of from 0.5 to 3 wt%, especially 1 to 15 2 wt%.

The composition may, if desired, comprise a thickening agent or gelling agent. Suitable thickeners are polyacrylate polymers such as those sold under the trade mark CARBOPOL, or the trade 20 mark ACUSOL by Rohm and Hass Company. Other suitable thickeners are xanthan gums. The thickener, if present, is generally present in an amount of from 0.2 to 4 wt%, especially 0.5 to 2 wti.

25 Dishwasher compositions usually comprise a detergency builder.

Suitable builders are alkali metal or ammonium phosphates, polyphosphates, phosphonates, polyphosphonates, carbonates, bicarbonates, borates, polyhydroxysulfonates, polyacetates, carboxylates such as citrates, and polycarboxylates. The 30 builder is desirably present in an amount of up to 90 wt%, preferably 15 to 90 wt%, more preferable 15 to 75 wt%, relative to the total weight of the composition. Further details of

suitable components are given in, for example, EP-A-694,059, EP-A-518, 720 and WO 99/06522.

The compositions can also optionally comprise one or more 5 additional ingredients. These include conventional detergent composition components such as further surfactants, bleaches, bleach enhancing agents, builders, suds boosters or suds suppressors, anti-tarnish and anti-corrosion agents, organic solvents, co-solvents, phase stabilizers, emulsifying agents, 10 preservatives, soil suspending agents, soil release agents, germicides, pH adjusting agents or buffers, non-builder alkalinity sources, chelating agents, clays such as smectite clays, enzyme stabilizers, anti-limescale agents, colourants, dyes, hydrotropes, dye transfer inhibiting agents, brighteners, 15 and perfumes. If used, such optional ingredients will generally constitute no more than 10 wt%, for example from 1 to 6 wit, the total weight of the compositions.

The builders counteract the effects of calcium, or other ion, 20 water hardness encountered during laundering or bleaching use of the compositions herein. Examples of such materials are citrate, succinate, malonate, carboxymethyl succinate, carboxylate, polycarboxylate and polyacetyl carboxylate salts, for example with alkali metal or alkaline earth metal cations, 25 or the corresponding free acids.

Specific examples are sodium, potassium and lithium salts of oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, Cl0-C22 fatty acids and citric acid. Other examples are organic phosphonate type sequestering agents such as those sold 30 by Monsanto under the trade mark Dequest and alkylhydroxy phosphonates. Citrate salts and Cl2-Cl8 fatty acid soaps are preferred.

Other suitable builders are polymers and copolymers known to have builder properties. For example, such materials include appropriate polyacrylic acid, polymaleic acid, and 5 polyacrylic/polymaleic and copolymers and their salts, such as those sold by BASF under the trade mark Sokalan.

The builders generally constitute from 0 to 3 wt%, more preferably from 0. 1 to 1 wt%, by weight of the compositions.

Compositions which comprise an enzyme may optionally contain 10 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 l wt% of 15 the compositions.

The compositions may optionally comprise materials which serve as phase stabilizers and/or co-solvents. Example are Cl-C3 alcohols such as methanol, ethanol and propanol. C1-C3 20 alkanolamines such as mono-, diand triethanolamines can also be used, by themselves or in combination with the alcohols.

The phase stabilizers and/or co-solvents can, for example, constitute 0 to 1 wt%, preferably 0.1 to 0.5 wt%, of the composition. The compositions may optionally comprise components which adjust or maintain the pH of the compositions at optimum levels. 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 30 dishwashing composition desirably has a pH of 8 to ll, a laundry composition desirable has a pH of 7 to 9, and a water

softening composition desirably has a pH of 7 to 9. Examples of pH adjusting agents are NaOH and citric acid.

The containers may themselves be packaged in outer containers if desired, for example non-water soluble containers which are 5 removed before the water-soluble containers are used.

In use the container are simply added to water where the dissolve. Thus they may be added in the usual way to a dishwasher or laundry machine, especially in the dishwashing 10 compartment or a drum. They may also be added to a quantity of water, for example in a bucket or trigger-type spray.

EXAMPLES

15 Using and industrial film laminating machine the following reels of laminated PVOH were produced. The solvent was applied by a series of rollers.

Trial 1 Fiat Trial 3 Trial 4 Trial 5 Trial 6 Solvent used Glycerol _ _ Environmental 25 C 25 C = = = = conditions 41% RH 39% RH Film Type 1 Aquafilm. = = = = = L712D Film Thickness l 90 micron = = 60 micron = = Film Type 2 Aicello PT _ Film Thickness 2 60 micron = = = = = _ Cylinders Temp. 27 C = = = = = Solvent Cylinders Temp. 47 C 24 C Colam. Reels Distance 90 micron 110 170 micron = = 170 micron Solvent _ micron

Cylinders Temp. Solvent The temperature of the reel used to distribute the solvent on the film.

Cylinders Temp. Colam. The temperature of the reels where the films are laminated 5 Reels Distance Solvent The distance between the reel and the film, the larger the distance the more solvent per m2

Claims

ChAIMS 1. A process for sealing a water soluble film to a 5 water soluble

member (preferably the water soluble member is a second water-soluble film), wherein a composition comprising at least one hydroscopic compound is applied to at least one of the surfaces of said film and said member before said surfaces are brought together.
2. A process for laminating two water-soluble films wherein a composition comprising at least one hydroscopic compound is applied to at least one of the surfaces of one of the films and said films are brought together.
3. A process according to claim 1 or 2 wherein each water soluble film is a poly (vinyl alcohol) film.
4. A process according to claim 1 wherein the water soluble 20 member comprises poly (vinyl alcohol).
5. A process according to any one of the preceding claims wherein the composition comprises a monohydric, a di-hydric or a polyhydric alcohol.
6. A process according to claim 5 wherein the polyhydric alcohol has 3-4 hydroxyl groups and 2-8 carbon atoms.
7. A process according to claim 6 wherein the composition 30 comprises glycerol.
8. A process according to any one of the preceding claims

wherein the composition is applied in the form of a mist.
9. A process according to any one of claims 1 to 7 wherein the composition is applied by printing or painting the 5 composition on the at least one surface.
10. A process according to any one of the preceding claims wherein the composition has a temperature of from to 10 to 40 C.
11. A process according to claim 1 or 4 wherein the water soluble member is in the form of a film.
12. A process according to claim 11 wherein the water soluble 15 member has been thermoformed.
13. A process according to claims l or 4 wherein the water soluble member has been injection moulded.

20
14. A process according to any one of the preceding claims wherein a sealing pressure is applied of from 60 to 120 bar
15. A process according to any one of the preceding claims wherein a heat sealing temperature applied of from 30 to 180 2S
16. A process according to any one of the preceding claims wherein the water soluble member is in the form of a pocket and a container which contains a composition is prepared.

30
17. A process according to claim 16 wherein the composition is anhydrous.
18. A process according to claim 16 or 17 wherein the composition is in the form of a liquid.
19. A process according to any one of claims 16 to 18 wherein 5 the container comprises at least two compartments.
20. A process according to claim 19 wherein the container is an injectionmoulded container comprising at least two compartments, a first compartment containing a first 10 composition and having a first opening closed by a first film and a second compartment containing a second composition and having a second opening closed by a second film, wherein the first film and the second film have the same or different water dissolution characteristics.
21. A process according to any one of claims 16 to 20 wherein the composition is a fabric care, surface care or dishwashing composition. 20
22. A process according to claim 21 wherein the composition is a dishwashing, water-softening, laundry, detergent or rinse aid composition.
23. A process according to any one of claims 16 to 21 wherein 25 the composition is a disinfectant, antibacterial or antiseptic composition.
24. A process according to any one of claims 16 to 21 wherein the composition is a refill composition for a trigger-type 30 spray.