CN110869289A

CN110869289A - Water soluble package

Info

Publication number: CN110869289A
Application number: CN201880045611.4A
Authority: CN
Inventors: R·库马尔; V·S·穆尔蒂·卡姆苏; J·M·罗斯曼; T·F·斯佩纳德尔; R·C·菲尔德
Original assignee: Unilever PLC
Current assignee: Unilever IP Holdings BV
Priority date: 2017-07-07
Filing date: 2018-07-03
Publication date: 2020-03-06
Anticipated expiration: 2038-07-03
Also published as: BR112019027194A2; EP3649057A1; PH12019502800A1; EP3649057B1; ZA202000094B; CN110869289B; CL2019003817A1

Abstract

A water-soluble package for containing a unit dose composition, the water-soluble package comprising a water-soluble matrix having a thickness of from 30 microns to 250 microns, the matrix comprising: (i) a film-forming material; and (ii)0.2 to 5 wt% of a surfactant; wherein the matrix has gas bubbles uniformly dispersed therein, the gas bubbles having an average diameter that is less than the total thickness of the matrix. Use of the water-soluble package for washing dishes or washing fabrics.

Description

Water soluble package

Technical Field

The present invention relates to a water-soluble package, and more particularly to a water-soluble package having a foamed water-soluble matrix containing a surfactant.

Background

Water-soluble packages known in the art typically encapsulate a cleaning or treatment composition, such as a dishwashing or laundry detergent composition, in a water-soluble matrix in the form of a film, sachet (sachet), pouch, and other types of containers or sachets. Water-soluble packaging is commonly used to simplify dispersing, pouring, dissolving and dosing compositions. The consumer may add the package directly to a mixing container, such as a tub, tank, or washing machine. Advantageously, this provides accurate dosing while eliminating the need for the consumer to measure the composition. The package can also reduce mess associated with dispensing similar compositions from a storage container, such as pouring a liquid laundry detergent from a bottle. The package also isolates the composition therein from contact with the user's hands. In summary, water-soluble packages containing pre-measured compositions provide consumer convenience in a wide variety of applications.

Water-soluble packages in the form of packages, sachets or containers are typically formed by sealing a water-soluble matrix to enclose a composition therein. In general, the release of the contents of such water-soluble packages must be rapid, and the water-soluble matrix encapsulating the contents must be completely soluble in water during use without leaving a residue.

A typical problem encountered by consumers is incomplete dissolution of the water soluble packaging when added to the detergent drawer of a washing machine. This problem is particularly acute when the washing machine uses cold water for washing purposes. To overcome this problem, water-soluble matrices are typically thin and are designed to provide high water solubility or reactivity.

Known commercially available PVOH-based thermoplastic films, such as M8630 from MonoSol LLC, are plasticized cold water soluble films based on medium molecular weight fully hydrolyzed PVOH with carboxylate groups. The film had a thickness of 75 microns and about 98g/m²The weight of (c).

Although water-soluble films that are completely soluble in cold water are known, they can be too sensitive to moisture and humidity to prepare a package for containing a consumer product such as a cleaning composition or treatment composition. High moisture or water droplets from wet-hand handling of the package can cause water-soluble packages to stick together and/or dissolve through the package and cause the package contents to leak.

In order to reduce the sensitivity of water-soluble films to moisture and humidity, solutions have been proposed in the past. One such solution is considered in US 2006/0165625A 1(Verrall et al), which describes a water-soluble article such as a film having Na applied to the outer surface of a PVOH pouch (pouch)₂SO₄A coating of the solution exhibiting increased resistance to pouch-to-pouch stickiness when exposed to small amounts of water. It also discloses a method for preparing the water-soluble film, which has a step of adding a salt to the water-soluble film-forming polymer and then forming a film from a mixture comprising a water-soluble film-forming composition and sodium sulfate therein.

In the recent past, it has been desired to develop,US8309203B2(The Procter&gamble Company,2012) describes a water-soluble matrix having improved resistance to dissolution prior to immersion in water by providing water-insoluble particles partially embedded in the water-soluble matrix. The water-soluble matrix has 33 to 167g/m²And a thickness in the range of 25 microns to about 125 microns. The water-soluble matrix may have a surfactant incorporated in an amount ranging from about 0.01% to about 1% by weight.

To obtain good cold water solubility, the water-soluble matrix may have to be so thin that, in addition to being sensitive to moisture and humidity, the mechanical properties including those related to processability and heat sealability are also impaired. In order to prepare a package from a water-soluble substrate, it is desirable that the water-soluble substrate must exhibit flexibility, i.e., the ability to accept wrinkles (creases) without cracking or becoming severely weakened, in order to be useful.

Yet another solution is proposed in US3695989B1(1972, Robert E Albert) which describes a foamed film and a cold water soluble package made from a foamed film of polyvinyl alcohol, polyvinyl pyrrolidone, or a mixture of the two, for packaging powdered materials. Packages containing powdered materials can be directly filled with water to enable a user to dose an accurate measurement without touching the contents of the package. The foamed film has uniformly dispersed bubbles having an average diameter of 1/3 that is less than the total thickness of the film.

Thus, the present inventors have investigated ways of improving water-soluble packaging, in particular, providing water-soluble packaging that performs properly and imparts the benefits of good cold water solubility, good processability and flexibility. However, the present inventors have noted that a foamed water-soluble matrix having a thickness of 30 to 250 micrometers can provide an improvement in cold water solubility, but is extremely sensitive to small amounts of moisture and atmospheric moisture, and a foamed water-soluble matrix having good bubble stability is also desired.

Disclosure of Invention

It has surprisingly been found that a water-soluble package comprising a foamy water-soluble substrate having a film-forming material and a low level of a surfactant, preferably an anionic surfactant, and also preferably an alkyl sulfate anionic surfactant, enables the creation and stabilization of a foam structure in said water-soluble substrate. The presence of the low level of surfactant in the foam-like structure of the water-soluble substrate provides a substrate with the flexibility required to prepare consumer product packages. Further, such a matrix is also thicker than a dense film of the same weight per unit area due to the presence of stable bubbles that enable it to exhibit good processability while maintaining good cold water solubility.

According to a first aspect of the present invention, there is disclosed a water-soluble package for containing a unit dose composition, comprising a water-soluble matrix having a thickness of from 30 microns to 250 microns, the matrix comprising a film-forming material and from 0.2 to 5% by weight of a surfactant, wherein the matrix has gas bubbles uniformly dispersed therein, the gas bubbles having an average diameter less than the total thickness of the matrix.

According to a second aspect of the present invention, there is disclosed the use of the water-soluble package of the first aspect for washing dishes, treating fabrics or washing fabrics.

Detailed Description

According to a first aspect of the present invention, there is disclosed a water-soluble package comprising a water-soluble substrate having a thickness of from 30 microns to 250 microns, the substrate comprising a film-forming material and from 0.2 to 5% by weight of a surfactant.

Water soluble package

By "water-soluble package" is meant any packaging structure suitable for enclosing and/or containing a composition or material, such as a dishwashing or laundry detergent composition or a fabric treatment composition. The water-soluble package can be in any packaging form, such as film packages, sachets, pouches, sachets, and containers. In a particular embodiment, the water soluble package is a single dose water soluble package.

The term "water-soluble" as used herein refers not only to structures that are completely water-soluble, but also includes some materials that are substantially water-soluble but have a structure in which they are not water-soluble; structures that are water soluble under different temperature conditions or different pH conditions, and water dispersible or water disintegrable structures.

The water-soluble package typically contains at least one compartment for containing the composition. In certain embodiments, the water-soluble package comprises two or more compartments. Each compartment may contain the same composition or a different composition than in the other compartment. Alternatively, each compartment may contain a different component (or mixture of components) of the composition than the other compartment. For example, a water-soluble package may contain two compartments, wherein each compartment is a mixture of different components, together forming a laundry cleaning composition, a fabric treatment composition, or a dishwashing composition.

The water-soluble package comprises a water-soluble matrix, which preferably encapsulates and/or contains the composition or material. In use, the water-soluble matrix may be dissolved in water to release the material or composition encapsulated within the matrix. Such materials and compositions include, but are not limited to, in particular, detergent compositions, such as dishwashing compositions, laundry detergent compositions or fabric treatment compositions. The material or composition may be in any of solid, granular, gel, particulate, tablet or liquid form. Preferably, the material or composition is in the form of a powder, granules, tablets or granules.

The water-soluble package may be designed as a dimensionally stable reservoir, such as in the form of a sachet, cartridge or container. It is also possible and preferred to form the water-soluble package as a non-dimensionally stable container, for example as a sachet or sachet. The shape of such water-soluble packages can be adapted to the conditions of use to a large extent. Various shapes such as tubes, pads, cylinders, bottles or trays are suitable. The water-soluble package of the present invention is conveniently in the form of a sachet, pouch or sachet. Such sachets may be formed from one or more films or sheets of a water-soluble substrate or from a tubular section of such a substrate, but are most conveniently formed from a single folded sheet or from two sheets, sealed together in the marginal regions by means of an adhesive or preferably by heat sealing. Although the sachet may be of any shape or size known in the art, a preferred sachet form according to the invention is a rectangular sachet formed from a single folded sheet of water-soluble matrix sealed on three sides.

Preferred sealing methods include heat sealing, solvent welding, and solvent or wet sealing. It is preferred that only the area where the seal is formed is treated with heat or solvent. The heat or solvent may be applied by any method, preferably on the closure material, preferably only on the area where the seal is to be formed. If a solvent or wet seal or weld is used, it may be preferable to also apply heat. Preferred wet sealing or solvent sealing/welding methods include selectively applying a solvent to the areas between the molds, or to the closure material, by, for example, spraying or printing it onto these areas, and then applying pressure to these areas to form the seal.

The formed pouch may then be cut by a cutting device. The cutting may be performed using any known method. It may be preferred that the cutting is also performed in a continuous manner, and preferably at a constant speed, and preferably when in a horizontal position. The cutting means may for example be a sharp article (sharp item) or a hot article (hot item), whereby in the latter case the hot article "burns" through the film/sealing area.

Water-soluble matrix

The disclosed water-soluble packages include a water-soluble matrix that generally forms one or more walls of the water-soluble package used to encapsulate the composition.

The water-soluble matrix may be in the form of a foamed film or a foamed sheet. The water-soluble matrix may be in the form of a woven, non-woven or cast structure. Preferably, the water-soluble matrix is thermoplastic.

The water-soluble matrix has a thickness in the range of 30 microns to 250 microns. Preferably, the thickness of the water-soluble matrix is at least 50 microns, still preferably at least 60 microns, further preferably at least 65 microns, and most preferably at least 75 microns, but generally not more than 180 microns, still preferably not more than 170 microns, and most preferably not more than 150 microns. Preferred water-soluble matrices have a thickness in the range of 75 microns to 150 microns.

Preferably, the water-soluble matrix has a density of 30g/m²To 70g/m²Basis weight of the range, morePreferably 35g/m²To 50g/m²Basis weight of the range. Preferably, the basis weight of the water-soluble matrix is at least 32g/m²And also preferably at least 34g/m²Most preferably at least 35g/m²But usually not more than 60g/m²It is also preferred that it does not exceed 65g/m²Most preferably not more than 50g/m²。

The water-soluble matrix according to the present invention is a foam-like structure having air bubbles dispersed therein. In a foamed water-soluble matrix, the average diameter of the gas bubbles is less than the total thickness of the matrix. Preferably, the volume of the gas bubbles in the matrix is 80% to 99% of the volume of the matrix, more preferably 85% to 95% of the volume of the matrix.

Film-forming materials:

the water-soluble matrix includes a film-forming material. As used herein, "film-forming material" refers to a material that, alone or in combination with a co-reactive material such as a crosslinker, is capable of forming a self-supporting continuous film on a surface when cured, preferably including polymeric materials that can associate to form a film on at least a horizontal surface and are capable of curing into a continuous film when any solvent or carrier present in the polymer emulsion, dispersion, suspension, or solution is removed. Such film-forming materials preferably comprise polymers or monomers capable of producing polymeric materials exhibiting properties suitable for the preparation of films or sheets or foams, for example by casting, blow moulding, extrusion or blow extrusion (blow extrusion) of the materials, as is well known in the art.

Preferred film-forming materials are polymeric materials, preferably polymers capable of forming a foamed film or foamed sheet. The polymeric material may be formed into a film or sheet, for example by casting, blow molding, extrusion or blow extrusion of the polymeric material, as is well known in the art.

Suitable film-forming materials are known and include any water-soluble polymer or mixture of polymers. In particular, the water-soluble matrix may comprise one or more film-forming materials. Examples of film-forming materials include polymers, copolymers or derivatives thereof selected from polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl acetate, polycarboxylic acids and salts, polyacrylates, water-soluble acrylate copolymers, polyaminoacids or peptides, polyamides, polylactic acids, polyaminopropyl sulfonic acids and salts thereof, polyitaconic acids and salts thereof, polyacrylamides, polyalkylene oxides, polyvinylpyrrolidone, pullulan (pullalan), cellulosics (cellulose, cellulose ethers, cellulose esters, cellulose amides, and including, for example, carboxymethyl cellulose and hydroxypropyl methyl cellulose), water-soluble natural polymers (e.g., guar gum, xanthan gum, carrageenan and starch), water-soluble polymer derivatives (e.g., modified starches including ethoxylated starches and hydroxypropyl starches, poly (acrylamido-2-methylpropanesulfonic acid sodium salt), poly (ethylene glycol) and poly (ethylene glycol) ether, poly (ethylene glycol ether), poly (ethylene glycol, Polymonomethyl maleate and salts thereof, and combinations thereof.

More preferred polymers are selected from the group consisting of polyacrylates and water-soluble acrylate copolymers, methylcellulose, sodium carboxymethylcellulose, dextrin, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, maltodextrin, polymethacrylates. Most preferably, the film-forming material comprises polyvinyl alcohol, polyvinyl alcohol copolymers, partially hydrolyzed polyvinyl acetate, modified polyvinyl alcohol preferably modified with carboxyl, vinylamide monomer and/or sulfonic acid groups or other functional groups known in the art to improve water solubility, polyvinyl acetate, polyvinyl pyrrolidone, carboxymethyl cellulose or hydroxypropyl methyl cellulose.

Also preferably, the film-forming material comprises or consists essentially of a vinyl polymer including homopolymers and copolymers having hydroxyl or carboxyl groups. Preferred polymers include polyvinyl alcohol, polyvinyl acetate, partially hydrolyzed polyvinyl acetate, modified polyvinyl alcohol, or mixtures thereof. Polyvinyl alcohol, polyvinyl acetate and modified polyvinyl alcohol can provide a stable water soluble matrix with a suitable dissolution rate. Preferably, the film-forming material in the water-soluble matrix is PVOH.

Mixtures of polymers may also be used as film-forming materials. This may be beneficial for controlling the mechanical and/or dissolution properties of the package, depending on its application and desired requirements. Suitable mixtures include, for example, mixtures in which one polymer has a higher water solubility than another polymer, and/or one polymer has a higher mechanical strength than another polymer. Also suitable are mixtures of polymers having different weight average molecular weights, for example, mixtures of polyvinyl alcohols or copolymers thereof having a weight average molecular weight of about 10,000 to 40,000, preferably about 20,000, and mixtures of polyvinyl alcohols or copolymers thereof having a weight average molecular weight of about 100,000 to 300,000, preferably about 150,000.

Preferably, the film-forming material is a film having a thickness of 1000 to 1X 10⁶Preferably 1X 10⁴To 3X 10⁵And also preferably 20,000 to 1.5X 10⁵The weight average molecular weight of (3).

Preferably, the content of film-forming material, e.g. polyvinyl alcohol polymer, in the water-soluble matrix is at least 40 wt.%, still preferably at least 50 wt.%, further preferably at least 55 wt.%, most preferably at least 65 wt.%, but generally not more than 85 wt.%, still preferably not more than 80 wt.%, most preferably not more than 75 wt.%.

The film-forming material is preferably a hydrolyzed polymer. In order to provide the desired film properties for making the package while maintaining an acceptable dissolution rate, it is preferred that the polymer is partially hydrolyzed, more preferably the polymer has a degree of hydrolysis in the range of 60% to 99%, preferably 60% to 98%, still preferably 60% to 90%, further preferably 65% to 85% and most preferably 75% to 85%. Most preferably, the degree of hydrolysis is between 75% and 80%. Preferably, the film-forming material is hydrolyzed polyvinyl acetate, preferably having a degree of hydrolysis of 60% to 90%.

Preferably, the method of preparing the water-soluble matrix from the film-forming material comprises the step of blowing or casting the film-forming material or a solution thereof, preferably the water-soluble matrix is produced by a casting process.

Surface active agent

The disclosed water-soluble matrix comprises 0.2 to 5 wt% of a surfactant. The desired level of surfactant in the water-soluble matrix according to the invention provides stability to the gas bubbles dispersed in the foamed water-soluble matrix and improves the flexibility and heat-sealing ability of the matrix, enabling the matrix to be advantageously used for preparing a package for containing a composition or material that has to be released.

Preferably, the amount of surfactant in the water-soluble base is at least 0.25 wt%, still preferably at least 0.3 wt%, further preferably at least 0.4 wt%, most preferably at least 0.45 wt%, but generally not more than 4 wt%, still preferably not more than 3.5 wt%, further preferably not more than 3 wt%, most preferably not more than 2 wt%.

Suitable surfactants may include anionic, nonionic, cationic, amphoteric and zwitterionic species or mixtures thereof. Suitable surfactants include, but are not limited to, polyoxyethylene polyoxypropylene glycols, alcohol ethoxylates, alkylphenol ethoxylates, tertiary acetylenic glycols and alkanolamides (nonionic surfactants), polyoxyethylene amines, quaternary ammonium salts and quaternized polyoxyethylene amines (cationic surfactants), and amine oxides, N-alkyl betaines and sulfobetaines (zwitterionic surfactants).

Preferably, the surfactant is an anionic surfactant selected from the group consisting of linear or branched alkyl sulfates, sulfonate surfactants, alkyl polyalkoxylated sulfates (also known as alkyl ether sulfates) which can be modified by sulfation of the higher C₈-C₂₀Fatty alcohols or mixtures thereof.

Examples of primary alkyl sulfate surfactants are those having the formula:

ROSO₃ ^-M⁺

wherein R is a straight chain C₈-C₂₀A hydrocarbyl group, M is a water-solubilizing cation. Preferably, R is C₁₀-C₁₆Alkyl radicals, e.g. C₁₂-C₁₄And M is an alkali metal such as lithium, sodium or potassium.

Examples of secondary alkyl sulfate surfactants are those having sulfate moieties in the "backbone" of the molecule, such as those having the formula: CH (CH)₂(CH₂)_n(CHOSO₃ ^-M⁺)(CH₂)_mCH₃Where M and n are independently 2 or higher, the sum of M + n is typically from 6 to 20, for example from 9 to 15, and M is a water-solubilizing cation, such as lithium, sodium or potassium.

Particularly preferredThe secondary alkyl sulfate is a (2,3) alkyl sulfate surfactant having the formula: for 2-sulfate and 3-sulfate, respectively, CH₂(CH₂)_x(CHOSO₃ ^-M⁺)CH₃And CH₃(CH₂)_x(CHOSO₃ ^-M⁺)CH₂CH₃. In these formulae, x is at least 4, for example 6 to 20, preferably 10 to 16. M is a cation, such as an alkali metal, for example lithium, sodium or potassium.

Examples of alkoxylated alkyl sulfates are ethoxylated alkyl sulfates having the formula: RO (C)₂H₄O)_nSO₃ ^-M⁺Wherein R is C₈-C₂₀Alkyl, preferably C₁₀-C₁₈E.g. C₁₂-C₁₆N is at least 1, for example 1 to 20, preferably 1 to 15, in particular 1 to 6, and M is a salt-forming cation, such as lithium, sodium, potassium, ammonium, alkylammonium or alkanolammonium. These compounds may particularly provide desirable fabric cleaning performance benefits when used in combination with alkyl sulfates.

Alkyl sulfates and alkyl ether sulfates are generally used in the form of mixtures comprising different alkyl chain lengths and, if present, different degrees of alkylation.

Other anionic surfactants which may be used are salts of fatty acids, for example C8-C18 fatty acids, in particular sodium or potassium salts, and alkylbenzenesulfonates, for example C₈-C₁₈An alkyl group.

Most preferably, the anionic surfactant is a sulfated anionic surfactant, preferably an alkali metal salt of lauryl sulfate, also preferably sodium lauryl sulfate. The sulfated anionic surfactant, preferably sodium lauryl sulfate, is included in the foamed water soluble matrix at a level in the range of 0.2 to 5 wt%, more preferably 0.25 to 2 wt%, still more preferably 0.4 to 1 wt% of the water soluble matrix.

Examples of nonionic surfactants are fatty acid alkoxylates, such as fatty acid ethoxylates, in particular those having the formula:

R(C₂H₄O)_nOH

wherein R is a straight or branched chain C₈-C₁₆Alkyl, preferably C₉-C₁₅Alkyl radicals, e.g. C₁₀-C₁₄Alkyl, and n is at least 1, for example 1 to 16, preferably 2 to 12, more preferably 3 to 10.

The alkoxylated fatty alcohol nonionic surfactant typically has a Hydrophilic Lipophilic Balance (HLB) in the range of 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 alcohols of 12 to 15 carbon atoms and which contain about 7 moles of ethylene oxide. Such materials are marketed by Shell Chemical Company under the trademarks Neodol 25-7 and Neodol 23-6.5. Other useful Neodols include Neodol 1-5, which is an ethoxylated fatty alcohol having about 5 moles of ethylene oxide and an average of 11 carbon atoms in the alkyl chain; neodol 23-9, ethoxylated C with about 9 moles of ethylene oxide₁₂-C₁₃A primary alcohol; and Neodol 91-10, which is ethoxylated C with about 10 moles of ethylene oxide₉-C₁₁A primary alcohol.

Alcohol ethoxylates of this type are also sold by Shell Chemical Company under the Dobanol trademark. Dobanol 91-5 is an ethoxylated C with an average of 5 moles of ethylene oxide₉-C₁₁Fatty alcohol, and Dobanol 25-7 is ethoxylated C with an average of 7 moles ethylene oxide per mole fatty alcohol₁₂-C₁₅A fatty alcohol.

Other examples of suitable ethoxylated alcohol nonionic surfactants include Tergitol 15-S7 and Tergitol 15-S-9, both of which are linear secondary alcohol ethoxylates available from Union Carbide Corporation. Tergitol 15-S-7 is C with 7 moles of ethylene oxide₁₁-C₁₅The mixed ethoxylated product of a linear secondary alkanol, Tergitol 15-S-9, was identical except that it had 9 moles of ethylene oxide.

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

Additional nonionic surfactants are, for example, C₁₀-C₁₈Alkyl polyglycosides, e.g. C₁₂-C₁₆Alkyl polyglycosides, in particular polyglucosides. These are particularly useful when a highly foaming composition is desired. Further surfactants are polyhydroxy fatty acid amides, e.g. C₁₀-C₁₈N- (3-methoxypropyl) glycidyl amide (glycinides), and ethylene oxide-propylene oxide block polymers having the Pluronic type.

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

Plasticizer

Preferably, the water-soluble matrix comprises a plasticizer. Examples of preferred plasticizers include, but are not limited to, glycerol, glycerin, diglycerol, hydroxypropyl glycerin, sorbitol, methylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, neopentyl glycol, trimethylolpropane, polyether polyols, ethanolamine, and mixtures thereof. When present, the plasticizer may be included in the water-soluble matrix material in a suitable amount as is generally known. Preferably, the plasticizer is a combination of glycerin and polyethylene glycol.

Method for preparing water-soluble packaging

The water-soluble packages of the present invention can be prepared using standard known techniques. For example, the water-soluble matrix is typically formed (preferably thermoformed) into a water-soluble matrix encapsulate (e.g., a film pouch, open capsule, or container). The water-soluble substrate encapsulate can then be filled with a composition, such as a dishwashing or laundry detergent composition or a fabric treatment composition. The fabric treatment composition may be a post-wash treatment composition, preferably added during the rinse stage, or a pre-treatment composition. The water-soluble envelope containing the composition or material may then be sealed, for example by sealing the edges of the envelope or attaching the envelope to one or more additional pieces of water-soluble substrate, so as to encapsulate the material or composition in a water-soluble package. The water-soluble package containing the composition may be in the form of single and multi-compartment pouches, sachets, bags and the like.

Water-soluble packages and other such containers comprising the water-soluble matrix described herein can be prepared in any suitable manner known in the art. There are a number of methods for making water-soluble packages. These include, but are not limited to, methods known in the art such as: a vertical form-fill-seal process, a horizontal form-fill-seal process, and forming the package on the surface of a circular drum in a mold.

In the vertical form-fill-seal process, a vertical tube is formed by folding a substrate. The bottom end of the tube is sealed to form an open package. The package is partially filled, allowing for a headspace. The upper portions of the open package are then sealed together to close the package and form the next open package. The first package is then cut and the process repeated. The packages formed in this way usually have a pillow shape.

The horizontal form-fill-seal process uses a die (die) with a series of dies therein. In the horizontal form-fill-seal process, the substrate is placed in a die and an open package is formed in these molds, which is then filled, covered with another layer of substrate, and sealed.

In a third method (forming the packs on the surface of a circular drum in a mould), the substrate is circulated over the drum and forms a bag which is passed under a filling machine to fill the open bag. Filling and sealing are performed at the highest point (top) of the circle described by the drum, e.g. typically filling is performed shortly before the rotating drum starts its downward rotating motion and sealing is performed shortly after the drum starts its downward motion.

In either method, which includes the step of forming the open package, the water-soluble matrix may first be molded or formed into the shape of the open package using thermoforming, vacuum forming, or both. Thermoforming includes heating the mold and/or substrate by applying heat in any known manner, such as by contacting the mold with heating elements, or by blowing hot air or using heating lamps. In the case of vacuum forming, vacuum assistance is used to help drive the substrate into the mold. In other embodiments, the two techniques may be combined to form a package, for example the substrate may be formed into an open package by vacuum forming, and heat may be provided to facilitate this process. The open package is then filled with the composition to be contained therein.

The filled open package is then sealed, which may be done by any method. In some cases, such as in horizontal package forming processes, closure is accomplished by continuously feeding a second material or substrate, such as a water-soluble substrate, onto the open-faced bag web, and then sealing the first and second substrates together. In such a method, the first and second substrates are typically sealed in the area between the molds, and thus between the packages formed in adjacent molds. Sealing may be accomplished by any method. Sealing methods include heat sealing, solvent welding, and solvent or wet sealing. The sealed web of packages may then be cut by a cutting device which cuts the packages in the web from each other into separate packages.

Application method

The water-soluble package of the present invention comprises a composition, which may be a fabric treatment composition or a fabric cleaning composition, which may be used in a method for treating a fabric article. Depending on the composition contained in the water-soluble package, the method of treating a fabric article with the water-soluble package may comprise one or more steps selected from the group consisting of: (a) pretreating the fabric article in a liquid formed by contacting the water-soluble package encapsulating the pretreatment composition with water, followed by washing the fabric article; (b) washing a fabric article with a wash liquor formed by contacting a water-soluble package enclosing a cleaning composition with water; (c) contacting the fabric article, after the laundering process, with a water-soluble package encapsulating a post-wash treatment composition; and (d) combinations thereof.

In certain embodiments, the method may include the step of selecting only a portion of the water-soluble wrapper for treating the fabric article. Desired portions or compartments of the water-soluble packaging can be cut and/or torn off and placed on or adhered to the fabric or placed in water to form a relatively small amount of wash liquor, which is then used to pre-treat the fabric or give post-wash treatment to the fabric. In this way, the user can customize the fabric treatment method according to the task at hand. In certain embodiments, at least a portion of the water-soluble package may be applied to the fabric to be treated using a device such as a brush or sponge. In yet another embodiment, the water-soluble packaging can be applied directly to the surface of the fabric. Any one or more of the above steps may be repeated to obtain the desired fabric treatment benefits.

Optional ingredients

Disintegrating agent:

to improve the dissolution rate of the matrix, disintegrants are preferably applied on the surface of the water soluble matrix, or they may be applied integrated into the water soluble matrix, or any combination thereof, in order to accelerate dissolution when the water soluble matrix is immersed in water. When present, the level of disintegrant is from 0.1 to 30% by weight, preferably from 1 to 15% by weight of the water-soluble matrix. Any suitable disintegrant known in the art may be used. Preferred disintegrants for use herein include corn/potato starch, methylcellulose/cellulose, mineral clay powders, cross-linked cellulose, cross-linked polymers, cross-linked starch.

Releasing agent:

suitable release agents include, but are not limited to, fatty acids and salts thereof, fatty alcohols, fatty esters, fatty amines, fatty amine acetates, and fatty amides. The release agent can be added to the water-soluble matrix in any suitable amount, including an amount in the range of about 0.02 to about 1.5 weight percent or in the range of about 0.04 to about 0.15 weight percent.

Additional optional ingredients may also include suitable extending agents, anti-caking agents, anti-blocking agents, including but not limited to: starch, modified starch, cross-linked polyvinylpyrrolidone, cross-linked cellulose, microcrystalline cellulose, and metal oxide. The extending agent, anti-caking agent, anti-blocking agent can be present in the water-soluble base in any suitable amount, including an amount in the range of about 0.1 to about 25 weight percent, preferably in the range of about 1 to about 15 weight percent.

Combinations encapsulated or contained in water-soluble packagesArticle (A)

The composition in the water-soluble package may be any composition intended for direct dosing when the package dissolves or disintegrates, preferably into a washing machine. The composition may for example be a fabric treatment or fabric washing, surface care or dishwashing composition. Thus, for example, it may be a dishwashing, water-softening, laundry or detergent composition, a rinse treatment composition, a fabric conditioning composition or a pretreatment composition. The composition may be in any form, not limited to powder, granules, tablets, microparticles, or a combination thereof.

Suitable compositions are generally packaged in amounts of from 0.5 to 100g, preferably from 5 to 100g, especially from 15 to 40 g. For example, the laundry composition may weigh from 0.5 to 40g, preferably from 15 to 40 g. Most preferably, the amount of composition is such that the user can dose the composition per unit for each wash cycle of the washing machine or for the pre-treatment or rinse treatment of the fabric.

The present invention will be described in more detail with reference to specific embodiments and examples.

Examples

Example 1: water-soluble matrix with polyvinyl alcohol and surfactant

The water soluble matrix according to the invention was prepared by mixing the ingredients as disclosed in table 1 below in a silverson mixer with a nitrogen purge to introduce gas bubbles. In the next step, the resulting mixture is cast onto a casting belt having a wet film thickness of about 380 to 750 microns, after which the cast mixture is dried in an oven to provide a film disc (film reel) having a final thickness of about 75 to 200 microns.

TABLE 1

Composition of water-soluble matrix

Water-soluble matrices having the compositions provided in table 1, including the surfactant (sodium lauryl sulfate) within the claimed range, were found to have stable gas bubbles dispersed in the structure, and were also soluble in cold water at a temperature of 10 ℃.

Example 2: evaluation of Water-soluble matrices with different types of surfactants and without surfactants

A comparative water-soluble matrix (Ex a) was prepared by: the ingredients as disclosed in table 2 below were mixed in a silverson mixer and air was introduced with vigorous mixing to give a solution with a density of 0.67 g/mL. In the next step, the resulting mixture was cast onto a casting belt having a wet film thickness of about 380 microns, after which the cast mixture was dried in an oven to provide a film disk. The resulting water-soluble matrix had a water content of 3.1 wt%.

The water-soluble matrix (Ex 2) according to the invention was prepared by: the ingredients as disclosed in table 2 below were mixed in a silverson mixer and the resulting solution had a solution density of 0.69 g/mL. In the next step, the resulting mixture was cast onto a casting belt having a wet film thickness of 380 microns, after which the cast mixture was dried in an oven to provide a film disc. The resulting water-soluble matrix had a water content of 2.5 wt.%.

The composition of the water-soluble matrix prepared as described above is given in table 2. The two water-soluble substrates were evaluated for heat sealability and film strength, water solubility, details are provided in table 2.

TABLE 2

*Steol

CS-370 from Stephan Company

The data in table 2 show that the comparative water-soluble matrix (Ex a), in which air was introduced by intensive mixing, started to collapse the bubble structure immediately after the stirring was stopped, while the bubbles remained stable longer than the water-soluble matrix (Ex 1) according to the present invention. The comparative water-soluble matrix (Ex a) was inferior in sealing strength and film strength when compared with the water-soluble matrix according to the present invention, and took longer to be completely dissolved in water at 5 ℃.

Claims

1. A water-soluble package for containing a unit dose composition, the water-soluble package comprising a water-soluble matrix having a thickness of 30 microns to 250 microns, the matrix comprising:

(i) a film-forming material; and

(ii)0.2 to 5 wt% of a surfactant;

wherein the matrix has gas bubbles uniformly dispersed therein, the gas bubbles having an average diameter that is less than the total thickness of the matrix.

2. The package of claim 1, wherein the gas bubbles have a total volume that is 80 to 99% of the total volume of the matrix.

3. The package of claim 1 or 2, wherein the surfactant is an anionic surfactant or a nonionic surfactant.

4. The package of claim 3, wherein the anionic surfactant is a sulfate surfactant.

5. The package of claim 4, wherein the sulfate anionic surfactant is sodium lauryl sulfate.

6. The package of any preceding claim, wherein the film-forming material is a polymer selected from the group consisting of: polyvinyl alcohol, polyvinyl acetate, modified polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl methyl cellulose, or mixtures thereof.

7. The package of claim 6, wherein the polymer has at least 1 x 10⁵The weight average molecular weight of (2).

8. The package of claim 6 or 7, wherein the polymer is partially hydrolyzed with a degree of hydrolysis ranging from 60% to 99%.

9. The package of any preceding claim, wherein the water-soluble matrix comprises a plasticizer selected from the group consisting of: glycerol, diglycerol, hydroxypropyl glycerol, sorbitol, methylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, neopentyl glycol, trimethylolpropane, polyether polyols, ethanolamines, and mixtures thereof.

10. The package of any one of the preceding claims, wherein the water-soluble matrix has 35g/m²To 50g/m²Basis weight of the range.

11. The package of any preceding claim, wherein the amount of film-forming material is from 55 to 80 wt% of the water-soluble matrix.

12. The package of any one of the preceding claims, wherein the water soluble matrix has a thickness of 75 microns to 150 microns.

13. The package of any one of the preceding claims, wherein the water-soluble matrix encapsulates a composition or material that is in the form of a powder, particulate tablet, or granule.

14. The package of claim 13, wherein the composition is a dishwashing composition, a fabric treatment composition, or a laundry detergent composition.

15. Use of the water-soluble package of any preceding claim for washing dishes or washing fabrics.