WO2016185202A1

WO2016185202A1 - Encapsulated benefit agent particles

Info

Publication number: WO2016185202A1
Application number: PCT/GB2016/051425
Authority: WO
Inventors: David John Duncalf; Melanie Jane Hughes; David Alan Pears; Lisa Elizabeth SCULLION; Magdalena Agnieszka Warunek
Original assignee: Revolymer (U.K.) Limited
Priority date: 2015-05-19
Filing date: 2016-05-17
Publication date: 2016-11-24

Abstract

Composite particles are disclosed, in which the composite particles comprise a peroxide generating bleach and a bleach activator dispersed throughout an encapsulating binder matrix, the matrix comprising a water-soluble polymer and an ionic species. The composite particles find applications in products wherein it is desirable to co-locate a bleach and a bleach activator without premature reaction therebetween. Methods of preparing the composite particles are also disclosed.

Description

ENCAPSULATED BENEFIT AGENT PARTICLES

FIELD OF INVENTION

The present invention relates to the protection of benefit agents, where the benefit agent is a reactive, pro-reactive or catalytic active(s) such as bleaching agents and bleaching agent activators that require protection from other formulation ingredients. This invention also relates to processes for making such composites, as well as their use in products with a wide range of applications within laundry, dishwashing, cleaning and disinfection as well as in textile treatment, wood, pulp and paper bleaching for example.

BACKGROUND TO THE INVENTION

The use of bleaching agents such as peroxides, solid peroxides, which release hydrogen peroxide in use (such as sodium percarbonate, sodium perborate) is common in bleaching, cleaning, sanitation and disinfection for many years. The efficacy of such materials is, however, strongly dependant on the temperature at which they are used. For example it is known that sodium percarbonate only shows satisfactory accelerated bleaching performance on textiles washed at 80 °C.

For modern textiles it is mostly not possible to wash them at high temperatures and, indeed, from an ecological standpoint it is clear that high temperature washing will use much more energy.

At lower wash temperatures the efficacy of peroxide releasing compounds can be enhanced by the use of bleach activators.

Suitable bleach activators may include the N-or O-acyl compounds; acylated alkylene diamines such as tetra acetyl ethylene diamine (TAED) and tetra acetyl glycourile, N- acylated hydantoines, hydrazines, triazoles, hydrotriazines, urazoles, di-keto piperazines, sulfurylamides, and cyanurates, as well as carboxylic acid anhydrides, especially phthalic acid anhydride and substituted maleic acid anhydrides, carboxylic acid esters, especially sodium-acetoxy-benzene sulfonate, sodium-benzoyloxy benzene sulfonate (BOBS), sodium- nonaoyloxy benzene sulfonate (SNOBS), sodium-lauroyloxy-benzene sulfonate (LOBS), sodium-isononaoyloxy benzene sulfonate (Iso-NOBS) and acylated sugar derivatives, like pentaglucose. Additionally activators based on hydroxy benzoic acids and derivatives thereof, such as DOBA, show effective bleaching enhancement.

l The presence of such activator compounds can improve the bleaching performance of sodium percarbonate solutions to the extent that the bleaching performance of sodium percarbonate alone at 95 °C is equivalent to that of sodium percarbonate in the presence of TAED bleach activator at 40 °C. It may also be beneficial to use mixtures of bleach activators in order to target differing stains: for example hydrophilic and hydrophobic stains. Hydrophobic derivatives of the readily water soluble sodium-phenolsulfonates are used, e.g. nonaoyloxy benzene sulfonate, acetoxy benzene sulfonate or benzoyloxy benzene sulfonate. These hydrophobic compounds may be combined with tetra acetyl ethylene diamine TAED, for example.

It is, however, preferable to co-locate the peroxide bleach and bleach activator together because in use, in the wash, the chemical reaction of bleach with activator is more facile if the local concentration of each with one another is high. However, due to the reactive nature of peroxide bleach and bleach activator materials a difficulty exists in that co-formulating these reactive agents together, in the form of a granule for example, may result in a loss of activity over time because of the premature reaction of bleach and bleach activator.

WO 94/15010 (The Proctor & Gamble Company) discloses a solid peroxyacid bleach precursor composition in which particles of peroxyacid bleach precursor are coated with a water-soluble acid polymer, defined on the basis that a 1 % solution of the polymer has a pH of less than 7.

US 6,107,266 (Clariant GmbH) discloses a process for producing coated bleach activating granules in which bleach activator base granules are coated with a coating substrate and are simultaneously and/or subsequently thermally conditioned. The coating substance is selected from C₈-C₃i fatty acids, C₈-C₃i fatty alcohols, polyalkylene glycols, non-ionic surfactants and anionic surfactants.

EP 0846757 (Unilever NV) discusses the problem of incorporating oxygen bleaches into liquid dishwashing formulations. It refers to Unilever patent US 5,200,236 which describes the coating of water soluble cores with paraffin wax.

EP 0436971 (Unilever) specifically describes the application of a single coating of paraffin wax and describes a core composed of a water-soluble/dispersible bleach material coated with a continuous waxy coating with a melting point of 40-50 °C. The document discusses the problems of incorporating actives in aqueous cleaning compositions. EP 0510761 (Unilever) describes a core composed of a water-soluble/dispersible material coated with a continuous waxy coating with a melting point of 40-50 °C and discusses the problems with incorporating actives in aqueous cleaning compositions. The core may be a bleach, a bleach catalyst, an enzyme, a peracid precursor, a diacylperoxide and a surfactant. The document describes the method of production which is by spray coating using a molten wax in a fluid bed. Applications are primarily for dishwashing products.

WO 95/30735 (Unilever PLC) describes the application of a wax/polyvinyl ether (PVE) coating. The PVE helps to modify the melting behaviour of the coating and improves flowability. Applications include liquid cleaning compositions such as dishwashing, where the particle is stable in alkaline formulation. Cores can include bleaches, both oxygen and chlorine based, or a H₂0₂ generating compound. Cores also include enzymes, proteins and bleach activators. The paraffin melts from between 40-60 °C and coating is achieved by spraying molten wax composition onto the particles.

EP 0533239 (Unilever PLC) describes the problems encountered when a bleach is formulated together with an enzyme in a liquid formulation. The solution to the problem is given by encapsulating the bleach and by incorporating a reducing agent to 'hold back' the bleach activity until the enzyme has completed its function. Interestingly it discusses that wax coatings are rendered useless if even a small crack is present in the coating. It describes the application of a single coat of paraffin wax and the encapsulation of a chlorine, bromine or peroxy(acid) bleaches.

WO 2012/140413 (Reckitt Benckiser) discloses a composite core particle which is encapsulated with a pH responsive acrylic polymer and which includes a claim describing a layer of hydrophobic material which can be a wax.

PCT/GB2010/002007 (WO 201 1/051681 ; Revolymer Ltd) describes encapsulation using pH responsive polymers in conjunction with bleach activators.

PCT/GB2012/050819 (WO 2012/140438; Revolymer Ltd) describes a similar technology in conjunction with enzymes and PCT/GB2012/050823 (WO 2012/140442; Revolymer Ltd) describes encapsulation with ionic responsive coating materials.

US 4545784 (Interox) which describes an intimate mixture of persalt (perborate

monohydrate only) and a bleach activator. US201 1/0009305 (P&G) which describes the co-location of bleach and activator in a particle layered with binder.

WO2007/127641 (OCI corp) which describes the process of forming an intimate mixture of peroxide bleach together with a bleach activator and held together using a binder formed from a fatty acid.

The present invention was devised with the foregoing in mind. SUMMARY OF INVENTION

According to a first aspect of the present invention, there is provided a composite particle comprising (i) discrete portions of at least one peroxide generating bleach and (ii) discrete portions of at least one bleach activator, said discrete portions of peroxide generating bleach and bleach activator being separated from each other and encapsulated within a binder matrix, wherein the matrix comprises:

at least one water-soluble polymer; and

at least one ionic species.

The composite particle may additionally comprise a coating comprising at least one wax or wax-like substance, and/or at least one amphiphilic copolymer.

According to a second aspect of the present invention, there is provided a process for the preparation of a composite particle defined herein, said process comprising the steps of: a) providing discrete portions of either:

i) at least one peroxide generating bleach, or

ii) at least one bleach activator,

wherein the discrete portions are each coated with a binder matrix comprising at least one water-soluble polymer and at least one ionic species;

b) contacting the discrete coated portions of step a) with a mixture of:

i) water, at least one water-soluble polymer, and at least one ionic species; and ii) either at least one peroxide generating bleach or at least one bleach

activator;

c) mixing the product of step b); and

d) isolating the composite particles;

e) optionally preparing a coating layer comprising a blend comprising:

(i) at least one water soluble polymer; and

(ii) at least one salt, or at least one surfactant, or a mixture thereof;

f) optionally preparing a coating layer comprising a blend comprising: (i) at least one water soluble polymer; and

(ii) at least one salt, or at least one surfactant, or a mixture thereof; and

(iii) optionally at least one wax or wax-like substance; and

(iv) optionally at least one amphiphilic polymer;

g) optionally applying a coating layer(s) to the core units to form a coated composite

particle;

with the proviso that: i) the at least one peroxide generating bleach may feature in only one of steps a) and b); and

ii) the at least one bleach activator may feature in only one of steps a) and b).

According to a third aspect of the present invention, there is provided a consumer product comprising a composite particle as defined herein.

According to a fourth aspect of the present invention, there is provided a use of a composite particle defined herein in the preparation of a consumer product.

According to a fifth aspect of the present invention, there is provided a use of an

encapsulating binder matrix defined herein as a phlegmatizer in a composite particle defined herein.

According to a sixth aspect of the present invention, there is provided a composite particle obtained, obtainable or directly obtained by a process of preparing a composite particle as defined herein.

According to a further aspect of the present invention, there is provided a process for the preparation of a composite particle as defined herein, the process comprising the steps of: a) providing discrete portions of either:

i) at least one peroxide generating bleach, or

ii) at least one bleach activator,

b) contacting the discrete coated portions of step a) with a mixture of:

i) water, at least one water-soluble polymer, and at least one ionic species; and ii) either at least one peroxide generating bleach or at least one bleach activator;

c) mixing the product of step b); and

d) isolating the composite particles;

with the proviso that

- the at least one peroxide generating bleach may feature in only one of steps a) and b); and

- the at least one bleach activator may feature in only one of steps a) and b).

Advantageously, the optionally coated composite particle of the invention allows the encapsulated benefit agents to be released under selective conditions. This is achieved by binding together within a particle, and optionally coating or encapsulating the benefit agents, or aggregates of benefit agents, with materials, which may be employed as binders or as coating materials, so as to provide (i) a binder which also serves to form a barrier between intimately mixed and otherwise incompatible benefit agents which forms the matrix aggregate (ii) provides a barrier to the ingress of water, moisture or aqueous solutions by virtue of a polymeric coating layer or layers against attack by formulation ingredients. The characteristics of the materials, polymer or polymers employed as binders or in the coating layers is such that a stimuli response is possible wherein the binder and/or the coating provided by the materials, polymer or polymers, will dissolve or disperse in response to stimuli events such as, for example, upon dilution (for example, an increase in water activity or a decrease in surfactant concentration), a change in pH, ionic strength or temperature in order to release the benefit agent contained and encapsulated within the matrix aggregate.

DESCRIPTION OF INVENTION

As used herein, the term "solid" includes granular, powder, bar and tablet product forms. As used herein, the term "fluid" includes liquid, gel, paste and gas product forms.

In the context of the invention, the term "polymer" may be used to indicate a polymer or copolymer containing one or more monomer constituents which may be randomly arranged within the polymer, or may exist in domains such as is the case for block copolymers, or may exist as branched chains which are arranged in a pendant fashion, or a polymer consisting of monomer units which alternate along the polymer backbone, or a polymer whose architecture is a mixture of two or more of the compositions detailed above.

Unless otherwise noted, all component or composition levels are in reference to the active portion of that component or composition, and are exclusive of impurities, for example, residual solvents or by-products, which may be present in commercially available sources of such components or compositions.

All percentages and ratios are calculated by weight unless otherwise indicated. All percentages and ratios are calculated based on the total composition unless otherwise indicated.

As described earlier, the problem of providing a shelf-stable detergent formulation which contains an active benefit agent, such as a peroxide generating bleach, in intimate mixture with a bleach activator still remains. In addition the problem of providing a stable solid, or powder, detergent formulation wherein the active benefit agents, such as bleach in intimate mixture with a bleach activator, for use within challenging climatic conditions such as in hot and humid areas also remains. The subject of this invention is the discovery of a composite material comprising a peroxide generating bleach in intimate mixture with a bleach activator which is bound together with a water soluble polymer, a salt and/or a surfactant and optionally a further layer or layers composed of the binding material ingredients which provides for enhanced production of bleaching activity and also enhances the stability of the active benefit agents both in solid detergent formulations and provides for protection of the active benefit agents against the negative interactions of the other necessary ingredients which are present in solid detergent formulations.

A particularly preferred embodiment of the invention relates to a composite particle comprising one or more core units containing the benefit agents comprising at least one bleach agent (oxidant) and at least one bleach activator (or catalyst reductant) and a binder comprising a blend of at least one water soluble polymer, at least one salt, and optionally at least one surfactant and optionally wax/polymer. Optionally a further coating may be applied to the composite aggregate which comprises a blend comprising at least one water soluble polymer, at least one salt, and optionally at least one surfactant, and optionally a further wax/polymer composite layer.

Yet another particularly preferred embodiment of the invention relates to a composite comprising one or more core units comprising at least one benefit agent (e.g. a bleach) and at least one bleach activator, and a binder comprising a blend comprising at least one water soluble polymer, at least one salt, at least one surfactant, and optionally a wax/polymer composite and optionally a coating, wherein said coating comprises a blend comprising at least one water soluble polymer, at least one salt, at least one surfactant, and optionally a wax/polymer composite. Ionic species

It will be understood by one of skill in the art that the term "ionic species" relates to any species that is capable of influencing the ionic strength of a medium into which it is placed. Known ionic species include salts and surfactants.

It will also be understood that the ionic species is not the water-soluble polymer component of the composite defined herein.

The quantity of the ionic species used as part of the present invention will vary depending on the particular ionic species and the particular water-soluble polymer used. However, it will be understood from the following paragraphs that the quantity of ionic species useful as part of the present invention will be readily apparent to one of ordinary skill in the art.

Irrespective of which ionic species and water-soluble polymer is used, the minimum quantity of ionic species is that which prevents or minimises the dissolution of the water-soluble polymer in a liquid detergent formulation containing 30 wt% or less (preferably 20 wt% of less, more preferably 10 wt% or less) of water. Hence, the minimum quantity of ionic species used as part of the composite is that which results in substantially no release of benefit agent from the composite when the composite is placed in liquid detergent formulations containing 30 wt% or less of water (preferably 20 wt% of less, more preferably 10 wt% or less). To prevent the release of the benefit agent, the skilled person will appreciate that it is necessary to maintain the ionic strength sufficiently high in order that the water-soluble polymer is not dissolved in liquid detergent formulations containing 30 wt% or less of water (preferably 20 wt% of less, more preferably 10 wt% or less). Conversely, when the composite is exposed to a larger body of water (e.g. during a washing cycle), the ionic strength falls markedly and the water soluble polymer is dissolved, thereby releasing the benefit agent.

Increased quantities of ionic species (i.e. greater than the minimum quantity) may also be used.

In a particular embodiment, when a PVOH-based water-soluble polymer modified by reaction with 2-10C aldehyde groups is used, the quantity of ionic species is 0.1 % to 50% of the total weight of the binder matrix. Suitably, the quantity of ionic species is 0.1 % to 40% of the total weight of the binder matrix. More suitably, quantity of ionic species is 0.1 % to 35% of the total weight of the binder matrix. In a particular embodiment, the ionic species is selected from:

i) chloride, sulphate and carbonate salts of the alkaline metals or alkaline earth metals; and

ii) surfactants represented by the general formula RS0₃ wherein R represents a hydrocarbon group selected from the group consisting of straight or branched alkyl radicals containing from about 8 to about 24 carbon atoms and aikyl phenyl radicals containing from about 9 to about 15 carbon atoms in the alkyl group: and M is a cation which typically is selected from the group consisting of sodium, potassium, ammonium, monoalkanolammonium, dialkanolammonium, triaikano!arnmonium, and magnesium cations and mixtures thereof. An exemplary surfactant is sodium dodecyi benzene sulfonate (SDBS).

Particularly suitable examples of ionic species include salts and ionic surfactants. Salts may suitably be inorganic or organic. Surfactants may suitably be anionic, cationic or amphoteric. Optionally the salt or surfactant may be oligomeric or polymeric, providing that it retains the ability to influence the ionic strength of the medium into which it is placed.

In one preferred embodiment of the invention, the composite comprises a binder matrix which comprises a blend of a water soluble polymer and a salt.

In another preferred embodiment, the composite core comprises a peroxide bleach, a bleach activator and a binder and optionally comprises a coating layer which comprises a blend comprising at least one water soluble polymer, at least one salt and at least one surfactant and optionally a wax/polymer composite.

Preferably, the salt is an inorganic salt. Suitable inorganic salts for use in the composites of the invention include, but are not limited to, halide, silicate, sulfate, citrates, carbonates, phosphates of the alkali or alkali earth metals or ammonium/alkyl ammonium salt forming cations. One or more of these salts may be present to act as fillers or bulking agents or density modifiers but also to act as de-tackifiers during the coating process so as to remove or reduce the tendency of the particles to coalesce together as the coating layer is applied whilst the layer is wet and tacky. The composite particles of the invention suitably comprise the ionic species as a substantially dry (i.e. solid) component.

In one highly preferred embodiment of the invention the salt is a chloride salt, more preferably, sodium chloride.

In another highly preferred embodiment the salt is magnesium sulfate, sodium sulfate aluminium sulphate or sodium carbonate. Suitably, the salt is sodium sulphate.

In a particular embodiment, when the ionic species is sodium carbonate, the total quantity of the ionic species within the binder matrix is 0.1 to 5%. Suitably, when the ionic species is sodium carbonate, the total quantity of the ionic species within the binder matrix is 0.1 to 3%. More suitably, when the ionic species is sodium carbonate, the total quantity of the ionic species within the binder matrix is 0.1 to 2%. Most suitably, when the ionic species is sodium carbonate, the total quantity of the ionic species within the binder matrix is 0.5 to 1 .5%.

In a particular embodiment, when the ionic species is sodium sulphate, the total quantity of the ionic species within the binder matrix is 12 to 24%. Suitably, when the ionic species is sodium sulphate, the total quantity of the ionic species within the binder matrix is 15 to 21 %. More suitably, when the ionic species is sodium sulphate, the total quantity of the ionic species within the binder matrix is 16 to 20%. Most suitably, when the ionic species is sodium sulphate, the total quantity of the ionic species within the binder matrix is 17.5 to 18.5%.

In a particular embodiment, when the ionic species is sodium chloride, the total quantity of the ionic species within the binder matrix is 20 to 40%. Suitably, when the ionic species is sodium chloride, the total quantity of the ionic species within the binder matrix is 25 to 35%. More suitably, when the ionic species is sodium chloride, the total quantity of the ionic species within the binder matrix is 27.5 to 32.5%. Most suitably, when the ionic species is sodium chloride, the total quantity of the ionic species within the binder matrix is 29 to 31 %.

Preferably, the binder and optionally the coating layer is prepared from a solution of the salt and the water soluble polymer. Preferably, the salt is present in a concentration of from about 0.0001 Molar (M) to about 1 M, more preferably from about 0.001 M to about 0.5 M. The solution concentration is highly dependent on the charge of the salt and the solubility of the polymer in the salt solution. NaCI (being composed of one "plus 1 " charge in combination with one "minus 1 " charge) can have a higher concentration before the polymer precipitates out) (MgS0₄ (i.e. "plus 2" + "minus 2") can only be present at a very much lower

concentration before the polymer precipitates out as a result of the increased total charge.)

In one highly preferred embodiment of the invention, the salt is present in an amount of from about 1 to about 95% based on the weight of the total composite, more preferably from about 5% to about 75%, even more preferably from about 10 to about 60%.

In one preferred embodiment of the invention, the composite comprises a binder matrix and optionally a coating layer which comprises a blend comprising a water soluble polymer and a surfactant and optionally a wax/polymer composite.

In another preferred embodiment, the composite comprises a binder matrix and optionally a coating layer which comprises a blend comprising at least one water soluble polymer, at least one surfactant and at least one salt.

Suitable surfactants for use in the composites of the invention include, but are not limited to, various anionic surfactants, especially the alkyl benzene sulfonates, alkyl sulfates, alkyl alkoxy sulfates and various nonionic surfactants, such as alkyl ethoxylates and alkylphenol ethoxylates.

Preferred surfactants may be represented by the general formula R S0₃M wherein R represents a hydrocarbon group selected from the group consisting of straight or branched alkyl radicals containing from about 8 to about 24 carbon atoms and alkyl phenyl radicals containing from about 9 to about 15 carbon atoms in the alkyl group. M is a cation which typically is selected from the group consisting of sodium, potassium, ammonium,

monoalkanolammonium, dialkanolammonium, trialkanolammonium, and magnesium cations and mixtures thereof.

Preferred anionic surfactants include the water-soluble salts of aikyibenzene sulfonic acid containing from about 9 to about 15 carbon atoms in the alkyl group and water-soluble alkyl sulfates containing from about 10 to about 18 carbon atoms. Also preferred surfactants can include the water-soluble salt of an alkyl polyethoxyiate ether sulfate wherein the alkyl group contains from about 8 to about 24, preferably from about 10 to about 18 carbon atoms and there are from about 1 to about 20, preferably from about 1 to about 12 ethoxy groups. Other suitable anionic surfactants are disclosed in U.S. Patent 4,170,565, Fiesher et al, issued October 9, 1979, incorporated herein by reference. One or more of these surfactants may be present in the layer to act as fillers or bulking agents or density modifiers but also to act as de-tackifiers during the coating process so as to remove or reduce the tendency of the particles to coalesce together as the coating layer is applied whilst the layer is wet and tacky.

In one especially preferred embodiment, the surfactant is sodium dodecylbenzene sulfonate (SDBS), sodium dodecyl sulfonate or sodium laureth sulphate.

In one highly preferred embodiment of the invention, the coating comprises a surfactant, preferably an anionic surfactant, and wherein the surfactant is present in an amount of from about 1 to about 60% based on the weight of the total coating, more preferably from about 1 to about 50 %, even more preferably from about 1 to about 20% based on the weight of the total composite.

In one preferred embodiment, binder composition and the optional coating layer is prepared using a surfactant concentration of from about 0.01 M to about 1 .0 M, more preferably, from about 0.1 M to about 0.25 M.

Water-soluble polymer

The composites of the invention comprise a binder matrix and optionally a coating layer comprising a blend of a water soluble polymer and either a surfactant or salt, or a mixture of a salt and a surfactant.

The term 'water-soluble polymer' used herein refers to a polymer which at a particular concentration is totally water-soluble or dispersible but can also include polymers which are essentially water-soluble but which also contain material(s) which are not water-soluble; such non-soluble materials may become water-soluble or dispersible at higher dilutions, or at increased temperature or in response to a change in pH or ionic strength (as non-limiting examples), or such materials may be inherently non-soluble and may be present as fillers, for example.

In one preferred embodiment of the invention, the water soluble polymer is a polyvinyl alcohol) (PVOH) or PVOH-based polymer. Most typically PVOH polymers are manufactured by the polymerisation of vinyl acetate to obtain polyvinyl acetate) (PVAc). Thereafter the PVAc is hydrolysed to polyvinyl alcohol), as follows:

Polyvinyl alcohol) (PVOH) Polymers

It will be appreciated that during hydrolysis of the PVAc, a number of the vinyl acetate groups present may remain unhydrolysed in the resulting polymer. Such polymers with a mixture of vinyl alcohol units and unreacted vinyl acetate units are also referred to by the name PVOH by those skilled in the art. As is well known in the art the degree of hydrolysis of a PVOH is important in determining its properties.

Optionally, a second monomer such as ethylene may be copolymerised with the vinyl acetate and the resulting copolymers hydrolysed to create vinyl alcohol groups in the same manner. The resulting polyvinyl alcohol) polymers typically have modified water solubility and other physical properties compared with those derived from homopolymers of vinyl acetate.

It will be appreciated that PVOH may also be prepared by the hydrolysis of other polyvinyl esters) such as polyvinyl formate), polyvinyl benzoate) or polyvinyl ethers). Similarly a copolymer of vinyl alcohol such as poly(ethylene-vinyl alcohol) may also be prepared by copolymerising the relevant monomer with a vinyl ester other than vinyl alcohol and hydrolysing the resulting polymer for instance. Such polymers are also within the scope of the present invention.

In one preferred embodiment of the invention, the water soluble polymer is a derivatised PVOH-based polymer.

Polyvinyl alcohol) (PVOH) grades with varying degrees of polymerization and hydrolysis are available under the trade name Mowiol (also known by the name Poval) (Kuraray

Chemicals) and include partly and fully saponified grades. Specific examples of fully saponified Mowiol include those known as 4-98, 6-98, 10-98, 20-98, 15-98, 15-99, 28-99, 30- 98 (CAS No: 9002-89-5). Specific examples of partly saponified Mowiol include those known as 3-85 G4, 4-88 G2, 8-88 G2, 18-88 G2, 23-88 G2, 47-88 G2, 3-85, 4-88, 5-88(also known as Poval 6-88), 8-88, 13-88, 18-88, 23-88, 26-88, 32-88, 40-88, 44-88, 47-88, 30-92, 4-88 LA, 8-88 LA and 40-88 LA (CAS No: 23213-24-5). The first number in the nomenclature denotes the viscosity of the 4 % aqueous solution at 20 °C as a relative measure for the molar mass of the Mowiol; the second number denotes the degree of hydrolysis of the polyvinyl acetate from which the Mowiol grade is derived. Mowiol 4-98 and 10-98 are particularly preferred. As an alternative to the use of Kuraray Mowiol/Poval trade name polymer, PVOH of appropriate viscosity and degree of saponification may be sourced from any other manufacturer (for instance Gohsenol branded material from Nippon Gohsei) may be used.

In general, preferred PVOH-based derivative polymers which are suitable in this application have high levels of hydrolysis within the range 60-100%. More preferred hydrolysis levels are between 79-100%. Most preferred hydrolysis levels are between 88-100% as these polymers have suitable water solubility characteristics. PVOH based derivative polymers which are preferred in this application have average molecular weights ranging from 1 ,000 Da to 300,000 Da which provide for aqueous solutions which are easily handled. The PVOH derivative may be a copolymer containing polyvinyl acetate monomers at varying degrees according to the degree of hydrolysis of the PVOH derivative. In addition it may be envisioned that a PVOH based polymer may conceivably contain 'PVOH' as a block within another polymer or copolymer or as grafts to, or from, another polymer or copolymer backbone or as a branched polymer containing short, oligomeric or polymeric cross-links within the polymeric or co-polymeric structure as a whole. A degree of cross linking may be beneficial in order to maintain structural integrity of the coated layer as well as to increase the barrier properties of the layer. Cross-linking may be carried out by any suitable technique which are well known and may include the use of agents such as epoxides, formaldehyes, isocyanates, reactive siloxanes, anhydrides, amidoamines, boric acid and suitably reactive transition metals and derivatives thereof.

In another preferred embodiment, the water soluble polymer comprises a homopolymer or copolymer of vinyl alcohol. In one preferred embodiment, the water soluble polymer is a polymer containing a vinyl alcohol repeat unit formed via post polymerisation partial hydrolysis of a vinyl ester (such as vinyl acetate) and at least one other monomer.

Preferably, the at least one other monomer contains an alkene group (i.e. carbon-to-carbon double bond) capable of undergoing copolymerisation with vinyl alcohol or a suitable precursor monomer such as a vinyl ester. In one highly preferred embodiment, the water soluble polymer comprises a copolymer of vinyl alcohol and an olefin, such as ethylene or propylene, preferably ethylene. More preferably, the olefin is present in an amount from about 1 to about 50 mol%, such as from about 2 to about 40 mol%, and most preferably from about 5 to about 20 mol% of the polymer backbone.

In another highly preferred embodiment, the water soluble polymer comprises a copolymer of vinyl alcohol formed from a copolymer of vinyl alcohol and an alkene-containing monomer, such as a vinylic (e.g. acrylic) or methacrylic monomer. Examples of suitable alkene- containing monomers which may be used in the present invention include, but are not limited to, styrene, acrylonitrile, methacrylonitrile, crotononitrile, vinyl halides, vinylidene halides, (meth)acrylamide, Ν,Ν-dimethyl acrylamide, vinyl polyethers of ethylene or propylene oxide, vinyl esters such as vinyl formate, vinyl benzoate or vinyl ethers (such as VeoVa™ 10 available from Momentive™), vinyl ethers of heterocyclic vinyl compounds, alkyl esters of mono-olefinically unsaturated dicarboxylic acids and in particular esters of acrylic and methacrylic acid; vinyl monomers with hydroxyl functionality 2-hydroxy ethyl (meth)acrylate, 2-hydroxy propyl (meth)acrylate, glycerol mono(meth)acrylate, 4-hydroxy butyl

(meth)acrylate, hydroxyl stearyl methacrylate, N-methylol (meth)acrylamide; vinyl monomers with additional functionality for crosslinking or adhesion promotion or post functionalisation of the vinyl polymers, such as diacetone acrylamide, aceto acetoxy ethyl (meth)acrylate, glycidyl methacrylate, 2-acrylamido-2-methylpropane sulfonic acid, (meth)acrylic acid, beta carboxy ethyl (meth)acrylate, maleic anhydride, styrene sulfonic acid, sodium sulfo propyl methacrylate, itaconic acid; Ν,Ν-dimethyl ethyl amino (meth)acrylate, Ν,Ν-diethyl ethyl amino (meth)acrylate, Ν,Ν-dimethyl ethyl amino (meth)acrylate, Ν,Ν-dimethyl propyl amino (meth)acrylate, Ν,Ν-diethyl propyl amino (meth)acrylate, vinyl pyridine, amino methyl styrene, crotonic acid, esters of crotonic acid, crotononitrile, vinyl imidazole; and basic amine monomers can be polymerised as the free amine, protonated salts or as a quaternised amine salt. Where a monomer is indicated with a prefix in brackets (e.g. meth) it shall be understood that it be used in a form with or without the methyl substitution, or alternatively an alternative alkyl group may be present. For example, in the case of acrylic acid, methacrylic acid or another derivative such as ethacrylic acid may be used.

In another particular embodiment, the modified PVOH is present in an amount of from about 50% to about 99.9% based on the weight of the total matrix. Suitably, the modified PVOH is present in an amount of from about 60% to about 99.9% based on the weight of the total matrix. More suitably, the modified PVOH is present in an amount of from about 65% to about 99.9% based on the weight of the total matrix.

Preferred derivatised PVOH materials may be produced via the reaction of a suitable aldehyde directly with the 'polymer bound secondary alcohol' functionality of the parent PVOH polymer or copolymer. Suitable aldehydes include: straight and branched chain alkyl aldehydes containing a branched or linear C4 to C22 carbon chain, acetals, ketals, esters, epoxides, isocyanates, suitably reactive oligomers, polymers and aromatic compounds such as aromatic aldehydes.

The degree of modification of the PVOH polymer with the aldehyde may be from about 0.1 % to about 50%, by this it is meant that the OH' portion of the PVOH has been replaced by the given percentage of acetal ether bonds. The person skilled in the art will appreciate that, for example, in the case of the reaction of an aldehyde with 'PVOH' for each molar quantity of aldehyde two molar quantities of 'OH' are substituted via the acetalation reaction. Hence a 50% derivatised PVOH will have been reacted with 25% of a suitable aldehyde, and, of course, the degree of hydrolysis of the PVOH will dictate the maximum level of substitution possible.

The aldehyde used to modify the PVOH is suitably a mono-aldehyde, such that no crosslinking of PVOH chains occurs.

It will be understood that modifying the PVOH with an aldehyde typically increases the hydrophobicity of the resulting polymer, thereby decreasing its water solubility. Since the composite particles of the invention are intended to release their benefit agent payload when they are brought into contact with large quantities of water (e.g. during a washing cycle), it is crucial that the modified PVOH does not become too hydrophobic. Nonetheless, the effect of the ionic species allows the composite particles of the invention to tolerate smaller quantities of water (e.g. spillages, or humid environments) without unintentional release of the benefit agent payload.

In an embodiment, the derivatised PVOH is obtained through modification of a PVOH polymer with a viscosity, as determined using a 4% aqueous solution of the derivatised PVOH at 20 °C, of between 2 and 20 mPa-s. Suitably, the derivatised PVOH is obtained through modification of a PVOH polymer with a viscosity of between 3 and 15 mPa-s. Most suitably, the derivatised PVOH is obtained through modification of a PVOH polymer with a viscosity of between 3 and 1 1 mPa-s.

In one highly preferred embodiment, the derivatised PVOH is obtained through modification of a PVOH polymer with a viscosity of between 9 and 1 1 mPa-s (e.g. Mowiol 10-98).

In another highly preferred embodiment, derivatised PVOH is obtained through modification of a PVOH polymer with a viscosity of between 5 and 6 mPa-s (e.g. Mowiol 5-88 also known as Poval 6-88).

In another highly preferred embodiment, derivatised PVOH is obtained through modification of a PVOH polymer with a viscosity of between 5 and 7 mPa-s (e.g. Mowiol 6-98).

In yet another highly preferred embodiment, derivatised PVOH is obtained through modification of a PVOH polymer with a viscosity of between 3 and 5 mPa-s (e.g. Mowiol 4- 98 and Mowiol 4-88).

In another embodiment, the derivatised PVOH is obtained through modification of a PVOH polymer with a degree of saponification (hydrolysis) of between 79 and 100 mol%. Suitably, the derivatised PVOH is obtained through modification of a PVOH polymer with a degree of saponification (hydrolysis) of between 85 and 100 mol%. More suitably, the derivatised PVOH is obtained through modification of a PVOH polymer with a degree of saponification (hydrolysis) of between 95 and 100 mol%.

In another embodiment, the modified water-soluble polymer has a structure that can be schematically represented by formula (III) shown below:

wherein each R_x is (1 -9C)alkyl, (2-9C)alkenyl or (2-9C)alkynyl,

x denotes the proportion of modified PVOH monomeric moieties,

y denotes the proportion of residual acetate monomeric moieties present in the polymer following hydrolysis to yield the PVOH, and

z denotes the proportion of unmodified PVOH monomeric moieties.

It will also be understood that formula (III) shows a schematic representation illustrating the structures of the various monomeric moieties that collectively constitute the modified PVOH. Hence, formula (III) does not necessarily imply that the water-soluble polymers are block copolymers or alternating copolymers. On the contrary, monomeric moieties x, y and z may be randomly distributed throughout polymers falling within the scope of formula (III). It will also be understood that PVOH-based polymers falling within the scope of formula (III) may comprise, in addition to monomeric moieties x, y and z, other monomeric moieties.

In an embodiment, having regard to schematic formula (III), between 0.1 and 50% of the available -OH groups of the water-soluble polymer have been modified to yield a moiety x. Suitably, between 1 and 15% of the available -OH groups of the water-soluble polymer have been modified to yield a moiety x. More suitably, between 2 and 12% of the available -OH groups of the water-soluble polymer have been modified to yield a moiety x

In another embodiment, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-10C aldehyde, such that between 0.1 and 50% of the -OH groups are modified by the 2-10C aldehyde. Suitably, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-10C aldehyde, such that between 1 and 15% of the -OH groups are modified by the 2-10C aldehyde. More suitably, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-10C aldehyde, such that between 2 and 12% of the -OH groups are modified by the 2-10C aldehyde. Even more suitably, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-10C aldehyde, such that between 2 and 10% of the -OH groups are modified by the 2-10C aldehyde. Most suitably, the water-soluble polymer is the product formed by reacting a PVOH-based polymer with a 2-10C aldehyde, such that between 4 and 9% of the -OH groups are modified by the 2-10C aldehyde.

In a particularly suitable embodiment, the 2-10C aldehyde referred to hereinbefore is not substituted with a charge-conferring group. Hence, the 2-10C aldehyde may be entirely unsubstituted, or may be substituted with one or more groups that are not cation-forming groups (such as amines) or anion-forming groups. In such embodiments, the resulting water- soluble polymer does not carry a permanent charge.

Suitably, the 2-10C aldehyde is butyraldehyde.

In one highly preferred embodiment, the derivatised PVOH is a 'butyrated' modification - wherein the degree of substitution (DS) by the butyraldehyde is from about 0.1 to about 50%, more preferably, from about 1 to about 20%, even more preferably, from about 2 to about 10%.

For the avoidance of doubt it will be appreciated that the term 'butyrated' recited herein refers to the reaction of the water soluble polymer with butyraldehyde. When modified with butyraldehyde the derivatised PVOH may also be referred to as PVB.

In an embodiment, the derivatised PVOH is a 4-9% butyrated PVOH.

In one highly preferred embodiment, the derivatised PVOH is a 5 % butyrated PVOH.

In one highly preferred embodiment, the derivatised PVOH is a 8 % butyrated PVOH.

In one embodiment, the derivatised PVOH is 5 % butyrated Mowiol 4-98 or 5 % butyrated Mowiol 10-98.

In another embodiment, the derivatised PVOH is 8 % butyrated Mowiol 4-98 or 8 % butyrated Mowiol 10-98.

In another embodiment, the derivatised PVOH is 5 % butyrated Mowiol 4-98 or 8 % butyrated Mowiol 4-98.

In another embodiment, the derivatised PVOH is 5 % butyrated Mowiol 5-88 (also known as Poval 6-88) or 8 % butyrated Mowiol 5-88 (also known as Poval 6-88).

In another embodiment, the derivatised PVOH is 5 % butyrated Mowiol 6-98 or 8 % butyrated Mowiol 6-98.

The composite particles of the invention do not include any cross-linked polymers. In particular, the water-soluble polymer is not crosslinked. Other suitable water soluble polymers which may be used in addition to derivatised PVOH include polyvinyl pyrrolidone), celluloses and modified celluloses, gelatines, polyvinyl acetates), maleic acid containing polymers or copolymers, starches, poly(carboxylic acids), acrylics such as poly HEMA/poly HEA and HEMA/HEA copolymers, and salts and mixtures thereof.

Advantageously the derivatised PVOH binder/coating-layer provides a degree of exothermic control to improve the thermal stability of the composite particle. The degree of exotherm control is provided by the presence of a water soluble polymer as described above in combination with a salt and/or surfactant as described above

As mentioned above, one disadvantage of peroxy bleaching benefit agents is their relatively poor stability when stored in the presence of bleach activators and typical detergent components, or in the presence of oxidisable materials such as organic materials which may include waxes and/or organic polymers. Such reactive oxidising agents may become unstable at elevated temperatures and in the presence of material which is readily oxidisable, considerable heat may be generated by reaction between the two. As a result a so-called self-accelerated-decomposition may occur accompanied by a significant exotherm.

Surprisingly it has been found that the presence of derivatised polyvinyl alcohol) and a salt (or surfactant), either the binder i.e. in contact with the peroxy bleach and the bleach activator surface, or as a coating layer, such as a 'top-coat' or an intermediate layer, affords an effective means by which the exothermicity of the composite particle may be controlled; such additives (commonly known as phlegmatizers) are components used to stabilise or desensitise reactive materials, particularly against undesired overheating. It is well known in the literature that polyvinyl alcohol) ('PVOH'), which exists more correctly as a co-polymer of 'vinyl alcohol' and vinyl acetate, may be used as a 'combustion control agent'. It is shown, for example, in Sekisui Specialty Chemicals Publication 201 1 -PVOH-9030 (which may be found on-line at www.selvol.com) that PVOH is able to gradually decompose when heat is applied to firstly release water and acetic acid (acetic acid is released as a result of the presence of vinyl acetate in 'PVOH' which may be present in a greater or lesser extent depending on the degree of hydrolysis of the 'PVOH') and then to further decompose in the presence of oxygen to produce carbon dioxide. This thermal decomposition process serves to mitigate the effect of heating applied upon the composite particle of the invention.

Another embodiment of the invention therefore relates to the use of a blend comprising: (i) at least one water soluble polymer; and (ii) at least one salt, or at least one surfactant, or a mixture thereof;

as a phlegmatizer.

Another embodiment of the invention relates to the use of a binder blend comprising:

(i) at least one water soluble polymer; and

(ii) at least one salt, or at least one surfactant, or a mixture thereof;

to stabilise or desensitise a benefit against undesired overheating.

In one preferred embodiment, the binder blend is admixed with a composite comprising the at least one peroxide generating bleach and bleach activator.

In another preferred embodiment, the binder blend is coated onto one or more core units comprising the at least one benefit agent.

The benefit agent may be a reactive species, such as a peroxy bleach material or a bleach activator or mixtures thereof.

It is generally undesirable to have organic material in the presence of an oxidising material such as a peroxy bleach material. Therefore it is surprising that the incorporation of a derivatised PVOH and a salt (or surfactant), which is in itself an organic material, within the composite either as a discrete layer or as a component part of the composite, acts as an effective phlegmatizer which controls undesired overheating.

Modified PVOH is described in WO 2004/031271 and WO 2009/103576. WO 2004/031271 describes the synthesis and process by which suitable modifications to PVOH may be made in order to produce a modified PVOH film which is resistant to dissolution in concentrated surfactant solution but which dissolves quickly when the surfactant solution is diluted sufficiently. WO2009/103576 also describes how multiple modifications may be made to modify PVOH and further describes how particles may be produced which are coated in this modified PVOH. Whilst mention is made of the utility afforded by coating particles with these modified PVOH materials, these patents do not in any way teach that derivatised PVOH and a salt (or surfactant) has the surprising ability to reduce or remove the excess heating or runaway reaction produced as a result of an oxidising agent, such as sodium percarbonate, being in the presence of an oxidisable material, such as an organic material, during a thermal event. Binder matrix

The terms "binder" and "binder matrix" used herein synonymously refer to the portion of the composite particle that encapsulates the core benefit agents (e.g. the discrete portions of bleach and bleach activator).

The binder matrix comprises a water-soluble polymer and at least one ionic species. The binder matrix may optionally comprise a wax or wax-like substance and an amphiphilic polymer. Suitably, the binder matrix comprises a water-soluble polymer being a polyvinyl alcohol) polymer modified by reaction with a 2-10C aldehyde, such that 1 -15% of the available -OH groups have been modified; and at least one ionic species.

In an embodiment, the composite comprises between 0.1 and 99.9% of the binder matrix based on the total weight of the composite. It will be understood that, depending on the particular application in which the composite is intended to be used, the benefit agent core may be coated to any extent. For example, where it is desirable to increase the barrier between the benefit agent core and the surrounding environment, it may be desirable to a high quantity of binder matrix coating. Conversely, in applications where the surrounding environment is such that a reduced barrier would be sufficient to adequately encapsulate the benefit agent core, it may be advantageous to use much lower quantities of binder matrix coating.

The composite may comprises between 0.1 and 99.9% of the binder matrix based on the total weight of the composite. Alternatively, the composite may comprises between 0.1 and 80% of the binder matrix based on the total weight of the composite. Alternatively, the composite may comprises between 0.1 and 60% of the binder matrix based on the total weight of the composite. Alternatively, the composite may comprises between 0.1 and 50% of the binder matrix based on the total weight of the composite

In a particularly suitable embodiment, the composite comprises between 0.1 and 70% of the binder matrix based on the total weight of the composite. Suitably, the composite comprises between 0.1 and 25% of the binder matrix based on the total weight of the composite. More suitably, the composite comprises between 0.1 and 15% of the binder matrix based on the total weight of the composite. Alternatively, the composite comprises between 0.1 and 10% of the binder matrix based on the total weight of the composite. Such compositions are particularly suitable in laundry detergent formulations (e.g. liquids and powders). In an alternative embodiment, the formed composite particle may include an additional separate outer coating of the binder matrix. The additional separate outer coating of the binder matrix may be present at a quantity of 0.1 to 50% based on the total mass of the formed composite. Alternatively, the additional separate outer coating of the binder matrix may be present at a quantity of 5 to 25% based on the total mass of the formed composite.

Optional layer

In one highly preferred embodiment of the invention, the composite may comprise a blend comprising:

(i) at least one wax or wax-like substance; and

(ii) at least one amphiphilic polymer.

In one highly preferred embodiment, this composition may form a further layer or coating upon the composite matrix core and may be in admixture with the binder within the core and/or within the coating.

Other embodiments of the invention may comprise one or more additional layers to e.g. a primer layer, a filler layer, a layer of an inorganic material, an adhesion promoting layer or a de-tackifying layer. These layers may be present at any position within the composite.

Other embodiments of the invention may be such that the particle itself is formed from a matrix comprising the core components (e.g. a bleach and a bleach activator ) and at least one derivatised polyvinyl alcohol and a salt (or surfactant) and optionally a wax or wax-like substance and at least one amphiphilic polymer. Such a matrix particle may additionally be coated further with layers as described herein.

Wax or wax-like substance

As mentioned above, the composite may comprise a blend comprising at least one wax or wax-like substance and at least one amphiphilic polymer within the matrix core and/or as a coating to the matrix core.

The term "wax or wax-like substance" refers to a material which is composed primarily of hydrocarbon groups such as a polymer formed from the polymerisation of alpha-olefins, but may also refer to a natural wax which may contain various types of chemical functionality depending on the source and the natural processes involved in its production. It should be noted that whilst natural waxes contain varied chemical functionality, in general, the degree of functionalisation is not sufficient to make the wax responsive in the manner which is described herein in respect of the amphiphilic polymer.

In essence the wax or wax-like substance is a material which is waterproof. This material may preferably be described as a wax, that is to say a material that has some plasticity at normal ambient temperatures and a melting point of above around 30 °C. A single wax may be used or a blend of two or more different waxes may be used in the composite.

Waxes are organic compounds that characteristically consist of long alkyl chains. The wax may be a natural wax or a synthetic wax. Natural waxes are typically esters of fatty acids and long chain alcohols. Terpenes and terpene derivatives may also be described as natural waxes. Synthetic waxes are typically long-chain hydrocarbons lacking functional groups.

In one preferred embodiment, the wax is a petroleum wax. Petroleum waxes include, but are not limited to, the following: paraffin waxes (made of long chain alkane hydrocarbons), microcrystalline waxes (e.g. with very fine crystalline structure), and petroleum jelly. For example, the Bareco Baker Hughes family of microcrystalline waxes are petroleum-derived microcrystalline waxes consisting of complex mixtures of paraffinic, isoparaffinic, and naphthenic hydrocarbons.

Paraffin waxes represent a significant fraction of petroleum and are refined by vacuum distillation. Paraffin waxes are typically mixtures of saturated n- and iso-alkanes,

naphthenes, and alkyl- and naphthene-substituted aromatic compounds. The degree of branching has an important influence on the properties.

Other synthetic waxes include, but are not limited to, polyethylene waxes (based on polyethylene), Fischer-Tropsch waxes, chemically modified waxes (for example, esterified or saponified), substituted amide waxes, and polymerised a-olefins. Some waxes are obtained by cracking polyethylene at 400 °C. The products have the formula (CH₂)nH₂, where n ranges between about 50 and 100. Additionally synthetic waxes may contain chemical functionalisation such as the carboxylated wax VYBAR C61 12 produced by Baker Hughes from which it is possible to produce other further functionalisation, such as pegylation by reaction with a suitable mono-, di-, or polyhydric alcohol, or for example, alkoxylation, silylation, siliconylisation and the like. Examples of suitable naturally occurring materials include beeswax, candelilla wax, carnauba wax, paraffin wax, ozokerite wax, ceresine wax, montan wax. Synthetic waxes are also available and examples in this class include microcrystalline waxes such as the Bareco™ range of microcrystalline waxes; the VYBAR™ range of highly branched polymers derived from the polymerisation of alpha olefins; the PETROLITE™ range of polymers and the POLYWAX™ range of polyethylenes.

In one highly preferred embodiment, the wax or wax-like material is selected from the VYBAR™ (Baker Hughes) range of highly branched polymers derived from the

polymerisation of alpha olefins and may be a single product chosen from the range or a mixture of two or more products in the range. Particularly preferred is the highly branched synthetic wax VYBAR 260™.

Blends of two or more natural waxes, or two or more synthetic waxes, or blends of one or more natural waxes and one or more synthetic waxes or blends of chemically functionalised synthetic waxes with other synthetic or natural waxes are also suitable for use in the present invention. As will be appreciated by those skilled in the art, such blends can be used to blend the properties of the two together, for instance allowing the melting point of the mixture to be finely tuned. It is also possible that wax or wax-like material may be formed by the mixture of two or more different materials that may not themselves be individually wax like. It can be envisioned that a number of mixtures may be suitable for this purpose such as oils which have been thickened by the addition of metal soaps, clays and polymer additives designed to harden oils and fats such as silica gels, polypropylenes and polyethylenes. As will be appreciated by those skilled in the art, most naturally derived waxes are themselves typically complex mixtures of different chiefly hydrophobic chemical species. It should be appreciated that the foregoing list is not exhaustive but merely illustrative of the range of natural and synthetic waxes available to the formulator. For the purposes of this invention, a particular material may be chosen with the intention of providing a suitable barrier layer for the core particle and having the necessary chemical and physical characteristics such as solubility, melting temperature, barrier properties (i.e. a barrier to reactive species, water and other formulation ingredients), crystalline and/or amorphous properties and hardness which allow for application to the core particle and which provide for an effective barrier.

Amphiphilic polymer

As mentioned, the matrix core may optionally comprise a blend of at least one wax or waxlike substance and at least one amphiphilic polymer within the matrix core or within the coating upon the matrix core. The purpose of the amphiphilic polymer in admixture with the wax or wax-like material is to provide a locus of weakness when the mixture finds itself in a trigger environment i.e. when the external environment is such that the chemical functionality present in the amphiphilic polymer will respond to the environment and dissolve or disperse, thereby causing the destabilisation of the mixture itself which, when present as a coating, leads to the release of the core material.

The amphiphilic polymer therefore needs to be a material which may be mixed with the wax or wax-like material and must contain chemical functionality which will respond to an external environment to produce a response in its chemistry.

In one preferred embodiment, the amphiphilic polymer is an amphiphilic copolymer.

As used herein, the term "copolymer" refers to a polymeric system in which two or more different monomers are polymerised together.

As used herein, the term "amphiphilic copolymer" refers to a copolymer in which there are clearly definable hydrophilic and hydrophobic portions.

In one preferred embodiment of the invention the polymer graft is a hydrophilic water soluble polymer that is able to act as the locus of weakness in the composite. For instance it may preferably be a poly(ethylene glycol)/poly(propylene oxide), polyvinyl alcohol), polyvinyl pyrrolidone), poly(styrene sulfonate), poly(acrylamidomethylpropylsulfonic acid) or similar molecules. Grafts like poly(ethylene/propylene glycol) are also preferred as they increase the ability of the system to react to changes in ionic strength.

The composite of the present invention may contain one or more amphiphilic copolymers. In one embodiment, the composite of the present invention comprises between about one and about four amphiphilic copolymers, for example one, two, three, or four copolymers, preferably one or two copolymers, most preferably one copolymer.

A wide range of amphiphilic copolymers may be suitable for use in the invention provided that they contain hydrophobic domains that are sufficient to ensure sufficient compatibility with the wax or wax-like material such that the encapsulates are stable in a formulated product. Any amphiphilic copolymer used in the invention must have sufficient hydrophilic functionality such that the amphiphilic polymer is responsive to changes in the formulation environment. As is well known in the art, in general the structures fall into several different forms of architectures including block copolymers, graft copolymers, highly branched and chain-extended or cross-linked polymers. A person skilled in the art of polymer chemistry would be familiar with such forms, together with methods for their preparation.

Many different polymers are suitable for use in the invention, provided they fulfil the key requirements of an amphiphilic polymer, that is to say they comprise a hydrophobic block that has compatibility with the wax or wax-like material, and a hydrophilic block capable of engineering responsiveness to changes in the environment. WO 2014140550 describes amphiphilic copolymer synthesis in detail and the teachings are incorporated herein.

In one highly preferred embodiment the amphiphilic polymer is a block copolymer of ethylene and ethylene oxide. In one highly preferred embodiment the amphiphilic polymer is selected from the range of block copolymers of ethylene and ethylene oxide known as Unithox™ (Baker Hughes) and may be a single product in this range or a mixture of two or more.

A range of polybutadiene polymers functionalised with maleic anhydride are sold under the Ricon brand by Sartomer (e.g. Ricon 130MA8) and Lithene by Synthomer (e.g. N4-5000- 5MA). A particularly preferred backbone is Lithene N4-5000-5MA. A further particularly preferred backbone is Lithene N4-5000-15MA. A number of useful backbones are also manufactured by Kraton (e.g. Kraton FG) and Lyondell (e.g Plexar 1000 series) in which maleic anhydride is grafted onto polymers or copolymers of monomers such as ethylene, propylene, butylene, styrene and/or vinyl acetate.

In one particularly preferred embodiment of the invention, the amphiphilic copolymer comprises a polybutadiene backbone and pendant hydrophilic grafts attached thereto, wherein each hydrophilic graft is derived from an NH₂ functionalised ethylene oxide and propylene oxide copolymer.

In one preferred embodiment, the hydrophilic groups grafted onto the maleic anhydride groups are polymers of ethylene oxide (i.e. PEOs) copolymerised with propylene oxide. In this embodiment, the amount of propylene oxide is preferably between 1 and 95 mol percent of the copolymer, more preferably between 2 to 50 mol percent of the copolymer, and most preferably between 5 to 30 mol percent of the copolymer. Preferably, the side chain precursor is of formula,

wherein x is 5 to 500, more preferably 10 to 100 and y is independently 1 to 125, more preferably 3 to 30. Preferably, x + y = 6 to 600, more preferably 13 to 130. The distribution of ethylene and propylene oxide units may be in the form of blocks as depicted above or as a statistical mixture. In any case the molar ratio of ethylene oxide to propylene oxide in the copolymer will favour ethylene oxide. Such side chain precursors are sold commercially by Huntsman under the Jeffamine brand and Clariant under the Genamin name.

A particularly preferred embodiment is the graft copolymer formed from the reaction of Lithene N4-5000-5MA with the Jeffamine known as M2070. Also a particularly preferred embodiment is the graft copolymer formed from the reaction of Lithene N4-5000-15MA with the Jeffamine known as M2070.

Example methodologies for the manufacture of the graft copolymers may be found in PCT/EP2008/066257 (WO 09/068570), PCT/EP2008/063879 (WO 09/050203) and

PCT/EP2008/066256 (WO 09/068569), the teachings of which are incorporated herein by reference.

Fillers/additional components

The composite according to the invention may also comprise one or more fillers in the core and/or the coating layers. Suitable fillers include inert binder or carrier materials which can be inorganic, organic, polymeric or oligomeric. For example, inorganic salts including sulfates, carbonates, chlorides, phosphates, acetates such as sodium sulfate or sodium carbonate or clays, talcs, silicas/silicates or micas may be used. Organic polymeric materials include, for example, polysaccharides, polyamides, polyvinyl alcohols), poly(ethers), including microcrystallines cellulose, functionalised cellulosics such as methyl, ethyl, propyl, carboxymethyl, carboxyethyl or carboxypropyl, hydroxymethyl, hydroxyethyl, or hydroxypropyl, cellulose, starch or modified starches.

In one preferred embodiment of the invention, the coating further comprises one or more additional ingredients selected from an inorganic salt, a surfactant, a plasticiser, a cosolvent, a wetting agent, a compatabiliser, a filler, a dispersant and an emulsifier. These additional ingredients aid film forming and/or aid the processability of the coating material.

Benefit agent

The composites of the invention comprise two or more core units comprising a incompatible benefit agents. As used herein, the term "benefit agent" includes any agent that is a reactive, pro-reactive or catalytic entity or mixture that requires protection from other formulation ingredients.

Depending upon the method used to form the composites the benefit agent may be a solid, a liquid, a gel or a mixture of these. In a preferred embodiment the benefit agent is a solid at the temperature of encapsulation. In another preferred embodiment the benefit agent is a liquid which is solidified or immobilised with a matrix or filler to make it easier to handle.

In one preferred embodiment, the benefit agent is a bleach or bleach system.

In one highly preferred embodiment the benefit agent is a combination of bleach and bleach activator which is held together in intimate mixture in the composite matrix particle.

In one particularly preferred embodiment the benefit agent is a bleach activator

In another particularly preferred embodiment the benefit agent is a preformed peracid; In another particularly preferred embodiment the benefit agent is a hydrogen peroxide source.

In another preferred embodiment the benefit agent is an enzyme.

In one preferred embodiment the benefit agent is a vitamin, essential oil, or other oil of nutritional benefit such as those from fish and vegetable sources.

In another preferred embodiment the benefit agent is a drug or pro-drug.

In another preferred embodiment the benefit agent is an agent for the treatment of human skin such as one intended to treat acne (e.g. benzoyl peroxide) or the signs of aging (e.g. botulinum toxin).

In a further preferred embodiment the benefit agent is a biocide or bacteriostat for the cleaning and disinfection of manufacturing equipment.

In another preferred embodiment, the benefit agent is a herbicide, insecticide, fungicide, plant growth regulator or fertilizer.

In one preferred embodiment, the benefit agent is in particulate form.

In another preferred embodiment, the benefit agents are in granulate form. For this embodiment, preferably the benefit agent(s) are combined with a granulating polymer or binder to form the matrix core. The benefit agents may be processed to form matrix core particles. This may be via granulation, compaction, pelletizing or extrusion and spheronisation. The benefit agent may be mixed with fillers, binders or disintegrants, or a mixture thereof. The benefit agent may also be mixed with further optional ingredients as desired. Fillers are selected upon their ability to absorb and retain water in order to achieve the optimal rheological conditions for lubrication and surface plasticization required during extrusion and spheronisation.

A non-limiting list of suitable fillers include, saccharides and their derivatives, disaccharides such as sucrose, polysaccharides and their derivatives such as cellulose or modified cellulose such as microcrystalline cellulose, sugars such as mannitol, cyclic oligosaccharides such as β-cyclodextrin and synthetic polymers such as polyvinylpyrrolidone (PVP) and crosspovidone (crosslinked PVP). Crosspovidone is particularly preferred. A particularly preferred source of crosspovidone is Kolloidon CL-M, a micronized product.

In one highly preferred embodiment the binder comprises

(i) at least one water soluble polymer; and

(ii) at least one salt, or at least one surfactant, or a mixture thereof;

(iii) optionally at least one wax or wax-like substance; and

(iv) optionally at least one amphiphilic polymer.

In the above case the binder serves to protect and to form a barrier for the admixed benefit agents and also is able to respond to changes in external media so as to release the active benefit agents when required. The binder also serves to provide a plegmatizing effect and hence to stabilise the active agents.

Non-responsive binders (non responsive in the sense that they not have not been designed to respond to a change in ionic strength, temperature, dilution etc in order to become soluble after such a change in environment. Non responsive binders are included in order to ensure that a particle or granule has sufficient mechanical strength to remain essentially as a intact particle or granule) may also be used to ensure that the matrix particles can be formed with the required mechanical strength for the end application. A non-limiting list of suitable binders include, anionic surfactants such as secondary alkyl sulfonate sodium salts, nonionic surfactants such as alcohol ethoxylates based on C12/C15 oxo alcohol, saturated fatty acids such as lauric acid, and synthetic polymers such as polyacrylate copolymers and polyvinyl alcohol (PVOH). Particularly preferred binders comprise the secondary alkyl sulfonate sodium salts, in particular Hostapur SAS from the group of anionic surfactants. Additional ingredients may be added prior to particle formation to provide additional stability, for example chelating agents such as etidronic acid to bind metal ions that prove detrimental to the stability of the bleach material.

Description of the responsive binder and optionally encapsulating coating

It has been surprisingly found that a coating comprising a derivatised polymer - the reaction product of PVOH with certain amounts of butyraldehyde, and at least one salt or at least one surfactant or a mixture thereof can provide for an aggregated matrix particle when used as a binder and when optionally used as a coating to produce an encapsulated for of the matrix particle, the core of which is a benefit agent (such as an intimate mixture of bleach and bleach activator), which is capable of protecting the ingredients from negative reactions with each other and also retaining the activity of the core material, when formulated into a cleaning product such as a solid laundry product, for significantly longer timescales than for which the core itself can retain without such internal protection from the binder or coating.

Without being bound by theory it is believed that the presence of a salt acts upon the derivatised PVOH in such a way as to effectively reduce the solubility of the derivatised PVOH when in the presence of solid or liquid formulations or when in the presence of moisture such as may be found in solid or powder formats where moisture ingress has occurred or humidity resulting from climatic conditions has 'dampened' the solid or powder.

It is well known that many water-soluble polymers may be 'salted-out' by the addition of a suitable concentration of salt as the solubility of water soluble polymers is dependant, amongst other considerations, on the presence of intra and inter hydrogen bonding which is disrupted by the presence of charged species such as salts and can lead to the precipitation of the polymer as a fine, insoluble, powder. US patent 5,429,874 by Vanputte discloses the use of salts in water soluble films which find utility in providing packaging protection to certain caustic materials.

In a similar fashion the presence of a surfactant, particularly a charged surfactant, can lead to the precipitation of water soluble polymer from solution if the concentration of the surfactant is sufficient to produce such an effect. Additionally it is believed that the presence of an organic modification to the backbone of the water-soluble polymer, for example the incorporation of hydrophobic groups along the backbone, can give rise to an interaction of these hydrophobic groups with the hydrophobic parts of the surfactant and hence lead to an interaction which can reduce the solubility in water of the polymer when local surfactant levels are high. Without being bound by theory it is believed that the presence of salt and optionally surfactant produces a responsive effect when water is present. The responsive binder (and/or binder used as an optional coating), immediately after manufacture, contains dry derivatised PVOH, salt and optionally surfactant. If, however, water is present in the bulk of the formulation, or in the case of a dry solid or powder, water is able to enter into the product then it is believed that the presence of salt and optionally surfactant in the presence of water produces an effect whereby the polymer increases its barrier to water as a result of the 'insolubilising' effect that salt containing water has upon certain water soluble polymers. In effect the water provides mobility to the salt ions which are then able to act upon the water soluble polymer in such as way as to decrease its solubility in water and hence increase its barrier properties to water. This process provides for a coating which may be formed from a solution of water-soluble polymer and salt or surfactant or a mixture thereof. It is envisaged that the concentration of salt and/or surfactant is kept at such a level so as the polymer is still soluble in the solution used for binding or coating, but may well be close to the point of insolubility. Upon formation of a matrix particle which is bound by the binder or a coating, around the particle, and removal of water and/or any solvent present it will be clear to the person skilled in the art that the concentration of salt and/or surfactant, now in the form of a matrix within the composite core and/or the optional polymeric coating film, is high and certainly high enough to maintain the insolubility of the polymer should any moisture of any kind permeate the coating.

Optionally the derivatised PVOH, salt and/or surfactant coating may be applied to a core particle which has already been agglomerated using the binder and may already have a coating layer applied, which may be composed of the same binder.

Optionally the binder, comprised of a derivatised PVOH polymer and comprising a salt or salts and a surfactant or surfactants or a mixture thereof may also, optionally, comprise a blend of wax, or wax like material, and an amphiphilic polymer. The following section details how such a blend may be prepared and how it may be applied to form a binder/coating composition.

In a preferred embodiment the binder, used to agglomerate and form the matrix particle, is comprised of a derivatised PVOH polymer and comprises a salt or salts and a surfactant or surfactants or a mixture thereof may also, optionally, comprise a blend of wax, or wax like material, and an amphiphilic polymer. In a preferred embodiment the binder comprised of a derivatised PVOH polymer and comprising a salt or salts and a surfactant or surfactants or a mixture thereof may also, optionally, comprise a blend of wax, or wax like material, and an amphiphilic polymer and may, optionally, be applied as a coating upon a matrix particle which as described above.

Preparation of blend

The wax or wax-like substance and the amphiphilic polymer may be blended together to form a homogenous mixture (i.e. a single phase blend) or they may be blended together to form a mixture of two or more phases. The phases present may be as a liquid in a solid or as a solid in a liquid or as a solid in a solid. Such blended materials may be produced by melting the two or more materials together to form a homogenous blend or, as described above, as a mixture of two or more phases.

Alternatively the two or more materials may be dissolved together to form a solution with any suitable solvent and then applied to the core by, for example, spray application or other suitable application method. Upon drying of this spray solution the blended mixture may then remain as a single phase dry coating or may phase separate to produce a dry coating which is multiphasic (two or more phases) as described above.

Alternatively a blended mixture of the wax or wax-like substance and the amphiphilic polymer may be produced by adding a solid material, such as a synthetic polymer, which has been finely ground (amphiphilic polymer) so as to produce a 'slurry' of the dry powdered polymer within the matrix of the wax or wax-like substance, which may be heated to produce a molten mixture, or the two materials (or more) may be added to each other using a suitable solvent to dissolve either the wax or wax-like substance, or both the amphiphilic polymer and the wax or wax-like substance. The polymer so added may not necessarily be a solid at room temperature and may well be a liquid or a viscous liquid and it may be mixed as described above either in the molten wax or wax-like substance, or in solution.

Particular embodiments of composite particles

As described hereinbefore, the present invention provides a composite particle comprising (i) discrete portions of at least one peroxide generating bleach and (ii) discrete portions of at least one bleach activator, said discrete portions of peroxide generating bleach and bleach activator being separated from each other and encapsulated within a binder matrix, wherein the matrix comprises:

at least one water-soluble polymer; and

at least one ionic species. In a particular embodiment, the at least one water-soluble polymer is a PVOH-based polymer. Suitably, the water-soluble polymer is a PVOH-based polymer that has been derivatised by reaction with butyraldehyde. . Suitably, the water-soluble polymer is a PVOH- based polymer, with a viscosity of between 3 and 12 mPa-s and a degree of saponification of between 85 and 100 mol% (e.g. Mowiol 5-88, Mowiol 10-98, Mowiol 6-98 and Mowiol 4- 98), that has been derivatised by reaction with butyraldehyde. More suitably, the water- soluble polymer is a PVOH-based polymer, with a viscosity of between 3 and 12 mPa-s and a degree of saponification of between 95 and 100 mol% (e.g. Mowiol 10-98, Mowiol 6-98 and Mowiol 4-98), that has been derivatised by reaction with butyraldehyde. Yet more suitably, the water-soluble polymer is a PVOH-based polymer, with a viscosity of between 9 and 1 1 mPa-s and a degree of saponification of between 95 and 100 mol% (e.g. Mowiol 10- 98), that has been derivatised by reaction with butyraldehyde. Even more suitably, the water- soluble polymer is butyrated Mowiol 10-98 at between 5% and 10% (degree of substitution) with butyraldehyde. Most suitably, the water-soluble polymer is butyl-modified Mowiol 10-98 at 8% (degree of substitution) with butyraldehyde.

The following represent particularly preferred embodiments of the water soluble polymer of the present invention:

i) the water soluble polymer is a 5% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 3 and 5 mPa-s and a degree of saponification between 95 and 100 mol % (e.g. a 5% butyrated Mowiol 4-98);

ii) the water soluble polymer is a 8% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 3 and 5 mPa-s and a degree of saponification between 95 and 100 mol % (e.g. a 8% butyrated Mowiol 4-98);

iii) the water soluble polymer is a 5% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 5 and 7 mPa-s and a degree of saponification between 95 and 100 mol % (e.g. a 5% butyrated Mowiol 6-98);

iv) the water soluble polymer is a 8% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 5 and 7 mPa-s and a degree of saponification between 95 and 100 mol % (e.g. a 8% butyrated Mowiol 6-98);

v) the water soluble polymer is a 5% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 9 and 1 1 mPa-s and a degree of saponification between 95 and 100 mol % (e.g. a 5% butyrated Mowiol 10-98);

vi) the water soluble polymer is a 8% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 9 and 1 1 mPa-s and a degree of saponification between 95 and 100 mol % (e.g. a 8% butyrated Mowiol 10-98). vii) the water soluble polymer is a 5% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 3.5 and 4.5 mPa-s and a degree of saponification between 86 and 89 mol % (e.g. a 5% butyrated Mowiol 4-88);

viii) the water soluble polymer is a 8% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 3.5 and 4.5 mPa-s and a degree of saponification between 86 and 89 mol % (e.g. a 8% butyrated Mowiol 4-88);

ix) the water soluble polymer is a 5% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 5 and 6 mPa-s and a degree of saponification between 86 and 89 mol % (e.g. a 5% butyrated Mowiol 5-88);

x) the water soluble polymer is a 8% butyrated PVOH obtained by butyration of a PVOH polymer with a viscosity of between 5 and 6 mPa-s and a degree of saponification between 86 and 89 mol % (e.g. a 8% butyrated Mowiol 5-88);

In another particular embodiment, the at least one peroxide generating bleach is sodium percarbonate.

In another particular embodiment, the at least one bleach activator is TAED.

In another embodiment, the at least one ionic species is sodium sulphate, magnesium sulphate or sodium chloride. Suitably, the at least one ionic species is sodium sulphate.

Description of particle formation and coating process

I) Core production process

Production of core particles may be carried out by any suitable means and the method is not critical to the invention save that the produced cores must be of sufficient mechanical strength to ensure that the particles are not damaged, broken up or otherwise significantly degraded by the process employed.

The core units may be prepared by co-agglomerating a granulating or binding agent with the benefit agent(s) in order to produce suitably sized particle cores. Preferably the binder chosen is as described herein and is based on a butyrated derivative of PVOH together with at least one salt and optionally at least one surfactant. Optionally a wax/amphiphilic polymer blend may also be used as a binder or as a filler or barrier material. As described herein an optional coating or coatings may be applied and may preferably be comprised of derivatised PVOH polymer, salt, optionally surfactant and optionally primer and/or filler components and/or layers and, optionally, the wax/amphiphilic copolymer composite or mixture thereof. A preferred size for such particles is between 0.25 to 5 mm, most preferably between 0.5 mm to 2.5 mm.

In one preferred embodiment, the core units are prepared by extrusion of narrow columnar 'noodles' of the benefit agent which may then be either cut to an appropriate length, preferably between 0.25 mm to 10 mm, more preferably between 0.5 mm to 5 mm, most preferably between 0.75 mm to 1 mm, or further spheronised or Marumerised in order to produce suitably sized particle cores which may optionally be coated.

II) Granulation/agglomeration process

Several granulation methods exist and may be conveniently characterised as processes employing sheer such as in high sheer granulation whereby the powders to be granulated are mixed at high speed and at high sheer by blades whilst binder and other components are added. Further techniques may employ the use of spray nozzles directed into powders undergoing sheer or under fluidisation.

Granules are formed by the addition of a granulation or binder liquid onto a powder bed which is under the influence of an impeller, screws or under fluidisation. This agitation results in the primary powder particles agglomerating to form larger particles the size of which is a function of the sheer applied, the binder used and the relative proportions of each.

III) Coating process

Encapsulation may be carried out by any suitable means and the method is not critical to the invention. For example, the coating material may be sprayed on as a solution or dispersion in a solvent/carrier liquid which is subsequently removed by evaporation. The coating material can also be applied as a powder coating e.g. by electrostatic techniques, although this is less preferred as the adherence of powdered coating material is more difficult to achieve and can be more expensive. If layer coatings are applied in particle form (such as powders or dispersions), it may also be necessary to coalesce the particles which make up each layer in order to produce a layer which is sufficiently coherent, without appreciable levels of flaws such as cracks, holes or 'flakiness', to produce a sufficiently effective barrier.

Organic solvents such as ethyl or isopropyl alcohol or chloroform can be used to form the solutions or dispersions depending on the nature and solubility of the solute, although this will necessitate a solvent recovery stage in order to make their use economic. Application, in the case of waxes and/or other hydrophobic materials, from the molten state is particularly advantageous as this method allows for the potential for the direct application of up to 100% solids and avoids complications such as solvent recovery, allowing time for drying and the issues associated with the safe handling of volatile and potentially flammable solvents.

Application from solvent solution(s) is advantageous as the coating materials may be applied as a continuous and homogenous film from solvent solution. Any suitable solvent may be used accepting that consideration for volatility, boiling point, solubility of materials within the solvent, safety and commercial aspects is undertaken.

Solutions are particularly advantageous, where possible, provided the solution has a sufficiently low viscosity to enable it to be handled. Preferably a concentration of from about 5% to about 50% and preferably from about 10% to about 25% by weight of the coating material in the solvent is used in order to reduce the drying/evaporation load after surface treatment has taken place. The treatment apparatus can be any of those normally used for this purpose, such as inclined rotary pans, rotary drums and fluidised beds.

In one highly preferred embodiment, the coating is applied to the cores either by fluid bed coating or fluid bed drying. The composite material blend (i.e. the derivatised PVOH, previously described, as binder may also be used as a coating material and may, optionally, also comprise the blend of wax or wax-like substance and the amphiphilic polymer) is applied to the core units from (solvent) solution or dispersion or from the melt if appropriate. It is preferable to apply aqueous dispersions (e.g. via an emulsion) of the composite blend allowing that annealing may potentially be necessary to coalesce the dispersion particles into a continuous film. Suitable plasticisers may also be employed to produce continuous films. The polymer is preferably applied to the core units as either a solution from (solvent) solution or from an emulsion or latex.

In one highly preferred embodiment the coating is applied from a solution of the derivatised PVOH polymer together with at least one salt and optionally at least one surfactant and may comprise other optional ingredients such as fillers, cosolvents, plasticisers etc.

In one highly preferred embodiment, the coating is applied from a dispersion (e.g. emulsion) of the derivatised PVOH polymer together with wax or wax-like substance and the amphiphilic polymer and other optional ingredients including surfactants, plasticisers, cosolvents, fillers etc. There are a number of different methods known in the art for making dispersions from waxes/polymers which may be utilised for the manufacture of aqueous dispersions used in this invention. In order for a dispersion to be stable it is necessary to control the particle size of the dispersed hydrophobic phase (e.g. the wax or wax like substance and/or amphiphilic polymer phase) in order to ensure that the dispersed phase does not settle out of suspension. To achieve this it is typically necessary to carefully control the method of addition of the hydrophobic material or blend (i.e. non-aqueous phase) to the water (or visa- versa) in the presence of chemical dispersants and/or surfactants whilst applying sufficient agitation/mechanical sheer to break up the oil phase. This hydrophobic phase may comprise the wax or wax like substance in the molten state and may also comprise a molten solution in combination with the amphiphilic polymer (e.g. the dispersion is hot and so the dispersed phase exists within the dispersion as liquid droplets). This hydrophobic phase may alternatively comprise the wax or wax like substance in the solid state and may also comprise a solid solution in combination with the amphiphilic polymer (e.g. the dispersion is cold, below the solidification point of the hydrophobic dispersed material and so will be a dispersion of solid particles). The amphiphilic polymer may be self dispersing meaning it is able to facilitate its emulsification and stabilisation in the water phase. Alternatively, if the polymer is not readily dispersible then surfactants may be required to disperse the polymer; these may be mixed into the oil phase prior to dispersion or may be present in the water phase prior to dispersion. It may also be necessary to include a plasticiser within the dispersion formulation so as to improve the coherency of the film which is produced from the coated emulsion. Typically materials which are solvents for the hydrophobic phase, such as chlorinated solvents, terpenes, hydrogenated rosin derivatives, hydrocarbon solvents or other substances which have at least a small solubility in the hydrophobic phase, are suitable. It should be recognised that, in the case of the amphiphilic substance, it may be present in both phases of the dispersion as it will have compatibility in both the hydrophobic and hydrophilic portions of the dispersion.

Surfactants may be used in the manufacture of a dispersion to stabilise the colloidal dispersion of hydrophobic phase in water. In a preferred embodiment, one or more surfactants are added to either the aqueous or hydrophobic phase or both. In the case of the aqueous phase, the surfactant is typically dissolved in water prior to use. When added to the hydrophobic phase, the surfactant may be dissolved in any solvent present or may, for instance, be dissolved or dispersed into the molten wax or wax like substance. A wide range of surfactants may be used, including non-ionic, anionic or cationic or zwitterionic (amphoteric) structures. The identity and chemistry of the surfactant used to stabilise the system is preferably selected to avoid incompatibility with the final formulation media.

In one highly preferred embodiment of the invention, cationic surfactants are used. These help to stabilise the formation of a stable dispersion, but once the core particles have been coated with the dispersion and the coated particles are then suspended in, for example, a laundry product containing anionic surfactant, the interaction between the cationic surfactants in the coating and the anionic surfactants in the media leads to the formation of an extra layer of this neutralised material and an increase in the barrier properties of the coating.

Conversely, in an alternative preferred embodiment of the invention, anionic surfactants are used. These help to stabilise the formation of a stable dispersion, but once the core particles have been coated with the dispersion and the coated particles are then suspended in, for example, a laundry product containing cationic surfactant the interaction between the anionic surfactants in the coating and the cationic surfactants in the media leads to the formation of an extra layer of this neutralised material and an increase in the barrier properties of the coating.

Other water soluble materials which behave as emulsifiers, such as polyvinyl alcohol), derivatised PVOH or other water soluble polymers and non-ionic surfactants, may be used so as to produce a stable dispersion having small dispersed droplet size. Polymeric surfactants may also be used.

The addition of surfactants and/or emulsifiers to stabilise the dispersion may result in the entrapment of air and subsequent foaming which can interfere with efficient manufacture of the dispersion. Thus, in one particularly preferred embodiment, an anti-foaming agent is added to the aqueous and/or hydrophobic phase prior to dispersion manufacture in order to suppress the generation of foam.

In fluid bed coating the particulate core material is fluidised in a flow of hot air and the coating solution, melt, emulsion or latex sprayed onto the particles and dried, where the coating solution. Melt, emulsion or latex may be applied by top spray coating, bottom spray (Wurster) coating or tangential spray coating, where bottom spray (Wurster) coating is particularly effective in achieving a complete encapsulation of the core. In general, a small spray droplet size and a low viscosity spray medium promote uniform distribution of the coating over the particles.

In fluid bed drying the particulate core material is mixed with the coating solution, emulsion or latex and the resulting moist product introduced to the fluid bed dryer, where it is held in suspension in a flow of drying air, where it is dried or in the case of molten material is congealed. Such systems are available from several suppliers including GEA Process Engineering (Bochum, Germany) and Glatt Process Technology (Binzen, Germany).

It will be appreciated that any method which allows for the application of an essentially continuous film of material may be used to produce the layers described herein and that the processes described are illustrative and not exhaustive of methods, such as curtain coating, other forms of spray coating and any other suitable methods which is able to produce substantially the same particle layer structures described herein.

Spraying on the coating(s) as an aqueous solution or dispersion in water is preferred.

Organic solvents such as ethyl or isopropyl alcohol or chloroform may be used to form the solutions or dispersions depending on the nature and solubility of the solute, although this will necessitate a solvent recovery stage in order to make their use safe and economic.

In one highly preferred embodiment, the coating is applied to the cores either by fluid bed coating or fluid bed drying. The coating is preferably applied to the core units as either a solution from solvent, including an aqueous solvent or from an emulsion or latex.

In one highly preferred embodiment, the coating is applied from an aqueous solution or dispersion and may include other optional ingredients including salts, surfactants, plasticisers, cosolvents, fillers etc.

In fluid bed coating the particulate core material is fluidised in a flow of hot air and the coating solution, melt, emulsion or latex sprayed onto the particles and dried, where the coating solution, melt, emulsion or latex may be applied by top spray coating, bottom spray (Wurster) coating or tangential spray coating, where bottom spray (Wurster) coating is particularly effective in achieving a complete encapsulation of the core. In general, a small spray droplet size and a low viscosity spray medium promote uniform distribution of the coating over the particles. Such systems are available from several suppliers including GEA Process Engineering (Bochum, Germany) and Glatt Process Technology (Binzen,

Germany). It will be appreciated that any method which allows for the application of an essentially continuous film of material may be used to produce the layers described herein and that the processes described are illustrative and not exhaustive of methods, such as curtain coating, other forms of spray coating and any other suitable methods which is able to produce substantially the same particle layer structures described herein.

Particular embodiments of composite particle preparation process

As described hereinbefore, the present invention also provides a process for the preparation of a composite particle defined herein, said process comprising the steps of:

a) providing discrete portions of either:

i) at least one peroxide generating bleach, or

ii) at least one bleach activator,

b) contacting the discrete coated portions of step a) with a mixture of:

activator;

c) mixing the product of step b); and

d) isolating the composite particles;

e) optionally preparing a coating layer comprising a blend comprising:

(i) at least one water soluble polymer; and

(ii) at least one salt, or at least one surfactant, or a mixture thereof;

f) optionally preparing a coating layer comprising a blend comprising:

(i) at least one water soluble polymer; and

(ii) at least one salt, or at least one surfactant, or a mixture thereof; and

(iii) optionally at least one wax or wax-like substance; and

(iv) optionally at least one amphiphilic polymer;

particle;

ii) the at least one bleach activator may feature in only one of steps a) and b). In a particular embodiment, the process comprises the steps of:

a) providing discrete portions of either:

i) at least one peroxide generating bleach, or

ii) at least one bleach activator,

wherein the discrete portions are each coated with at least one water-soluble polymer and at least one ionic species;

b) contacting the discrete coated portions of step a) with a mixture of:

activator;

c) mixing the product of step b); and

isolating the composite particles;

In an embodiment, when the peroxide generating bleach forms part of the mixture of step b), the bleach is first provided with a coating of an encapsulating binder matrix comprising at least one water soluble polymer and at least one ionic species.

Suitably, step a) comprises providing discrete portions of at least one peroxide generating bleach, wherein the discrete portions are each coated with at least one water-soluble polymer and at least one ionic species.

Suitably, step b) comprises contacting the discrete coated portions of step a) with a mixture of: i) water, at least one water-soluble polymer, and at least one ionic species; and ii) at least one bleach activator.

Suitably, the mixture of step b) is provides as a slurry.

In an embodiment, once isolated, the composite particles are dried at a temperature of about 25 to 75 °C for about 5 mins to 1 hour. Suitably, the isolated composite particles are dried at a temperature of about 50 °C for about 12 to 20 mins. More suitably, the drying step is conducted in the presence of a flow of air that is sufficient to cause fluidisation of the composite particles.

Consumer and professional product formulations

As described hereinbefore, the present invention also provides a consumer product comprising a composite granule as defined herein.

As described hereinbefore, the present invention also provides a use of a composite particle defined herein in a consumer product.

In an embodiment, the consumer product is a cleaning, bleaching or sterilizing product.

Another aspect of the invention relates to formulations comprising a composite as described above. The formulations may be solid or liquid. The formulation may be a product intended for domestic use or businesses or institutions for instance in laundry or dishwash products and detergents. Other preferred examples of consumer product formulations include personal care and cosmetic formulations, surface cleaning formulations, pharmaceutical, veterinary, food, vitamin, mineral and nutritional compositions. Further preferred examples include formulations for use in agriculture and a range of industries including mining and manufacturing, for instance in the production of food, flavours, fragrances and beverages or for use in areas such as paper and pulp manufacture, sanitation and disinfection, lubrication aids, oil field technology, fuel additives, dyes and pigment technology, laundry softening - including laundry actives and polymeric ingredients - textile lubricants, softening agents, enzymes, whitening agents and shading dyes.

Consumer products include those relating to baby care, beauty care, fabric and home care, family care, feminine care, or devices generally intended to be used in the form in which it is sold. Such products include, but are not limited to, diapers, bibs, wipes; products for and/or methods relating to treating hair (human, dog, and/or cat), including, bleaching, colouring, dyeing, conditioning, shampooing, styling; deodorants and antiperspirants; personal cleansing; cosmetics; skin care including application of creams, lotions, and other topically applied products for consumer use including fine fragrances; and shaving products, products for and/or methods relating to treating fabrics, hard surfaces and any other surfaces in the area of fabric and home care, including: air care including air fresheners and scent delivery systems, car care, dishwashing, fabric conditioning (including softening and/or freshening), laundry detergency, laundry and rinse additive and/or care, hard surface cleaning and/or treatment including floor and toilet bowl cleaners, and other cleaning for consumer or institutional use; products and/or methods relating to bath tissue, facial tissue, paper handkerchiefs, and/or paper towels; tampons, feminine napkins; products and/or methods relating to oral care including toothpastes, tooth gels, tooth rinses, denture adhesives, tooth whitening; vitamin products: including tablets, soft and hard capsules, gel and liquid formats and containing vitamins or other benefit agents which require stabilisation due to adverse interaction with other formulation ingredients or natural processes such as instability to oxidation; agrochemical products which include: products or formulations containing herbicides, fungicide, insecticides, plant or insect hormones or growth regulators or fertilizers such products requiring stabilisation of the benefit agent to prevent degradation of the benefit agent due to negative interactions with formulation ingredients or to prevent degradation due to adverse chemical reactions which result in a reduction of activity of the benefit agent over time when in formulation; pharmaceutical products, whereby a benefit agent may require stabilisation in order to avoid degradation caused by adverse interactions with other formulation ingredients or to prevent degradation from chemical reactions such as, for example, oxidation. Pharmaceutical product formats may take the form of powders, granules, capsules both hard and soft, such capsules may even be engineered to release at a particular location with the human body such as, for example, an enteric polymer capsule designed to survive the environment of the stomach and to be able to release within the gut. Other formats may include liquids, gels or pastes; Veterinary products whereby benefit agents may be protected from adverse reactions with other formulation ingredients to provide stable products which are able to deliver activity during application usage. Veterinary Product formats may take the form of powders, granules, capsules both hard and soft, such capsules may even be engineered to release at a particular location with the body such as, for example, an enteric polymer capsule designed to survive the environment of the stomach and to be able to release within the gut. Other formats may include liquids, gels or pastes.

In one preferred embodiment, the formulation is a cleaning and/or treatment composition. As used herein, the term "cleaning and/or treatment composition" is a subset of consumer products that includes, unless otherwise indicated, beauty care, fabric and home care products. Such products include, but are not limited to, products for treating hair (human, dog, and/or cat), including, bleaching, colouring, dyeing, conditioning, shampooing, styling; deodorants and antiperspirants; personal cleansing; cosmetics; skin care including application of creams, lotions, and other topically applied products for consumer use including fine fragrances and shaving products, products for treating fabrics, hard surfaces and any other surfaces in the area of fabric and home care, including: air care including air fresheners and scent delivery systems, car care, dishwashing, fabric conditioning (including softening and/or freshening), laundry detergency, laundry and rinse additive and/or care, hard surface cleaning and/or treatment including floor and toilet bowl cleaners, solid, granular or powder-form all-purpose or "heavy-duty" washing agents, especially cleaning detergents; liquid, gel or paste-form all-purpose washing agents, especially the so-called heavy-duty liquid types; liquid fine-fabric detergents; hand dishwashing agents or light duty dishwashing agents, including those of the high-foaming type; machine dishwashing agents, including the various tablet, granular, liquid and rinse-aid types for household and institutional use; liquid cleaning and disinfecting agents, including antibacterial hand-wash types, cleaning bars, mouthwashes, denture cleaners, dentifrice, car or carpet shampoos, bathroom cleaners including toilet bowl cleaners; hair shampoos and hair-rinses; shower gels, fine fragrances and foam baths and metal cleaners; as well as cleaning auxiliaries such as bleach additives and "stain-stick" or pre-treat types, substrate-laden products such as dryer added sheets, dry and wetted wipes and pads, nonwoven substrates, and sponges; as well as sprays and mists all for consumer or/and institutional use; and/or methods relating to oral care including toothpastes, tooth gels, tooth rinses, denture adhesives, tooth whitening.

In one highly preferred embodiment, the formulation is a laundry product either as a solid, powder, granular, bar and tablet format.

In another preferred embodiment, the formulation is a fabric and/or hard surface cleaning and/or treatment composition. As used herein, the term "fabric and/or hard surface cleaning and/or treatment composition" is a subset of cleaning and treatment compositions that includes, unless otherwise indicated, granular or powder-form all-purpose or "heavy-duty" washing agents, especially cleaning detergents; liquid, gel or paste-form all-purpose washing agents, especially the so-called heavy-duty liquid types; liquid fine-fabric detergents; hand dishwashing agents or light duty dishwashing agents, including those of the high-foaming type; machine dishwashing agents, including the various tablet, granular, liquid and rinse-aid types for household and institutional use; liquid cleaning and disinfecting agents, including antibacterial hand-wash types, cleaning bars, car or carpet shampoos, bathroom cleaners including toilet bowl cleaners; and metal cleaners, fabric conditioning products including softening and/or freshening that may be in liquid, solid and/or dryer sheet form ; as well as cleaning auxiliaries such as bleach additives and "stain-stick" or pre-treat types, substrate-laden products such as dryer added sheets, dry and wetted wipes and pads, nonwoven substrates, and sponges; as well as sprays and mists. All of such products which are applicable may be in standard, concentrated or even highly concentrated form even to the extent that such products may in certain aspect be non-aqueous. In a preferred embodiment of the invention the composite of the invention is suitable for inclusion in a liquid or powder/solid formulation as a coated material, the coating of which is readily soluble or dispersible in the application environment, whereupon the benefit agent(s) will be released.

The present invention is further described by way of the following non-limiting examples. EXAMPLES

SYNTHESIS EXAMPLE 1 : Preparation of butyl-modified Mowiol 10-98 and Mowiol 4-98 at 8% (Degree of Substitution - DS) with Butyraldehyde (PVB 10-98; PVB 4-98)

A 2-litre reaction vessel was charged with Mowiol (10-98 or 4-98, 100 g) and de-ionised water (900 g). The reaction vessel was placed onto a heating block and fitted with a head unit, anchor stirrer, nitrogen line, condenser and bubbler. The mixture was then heated to 80 °C and stirred under nitrogen for 1 hour or until all Mowiol had dissolved. After this time, the temperature of the heating block was reduced to 60 °C and 2 M HCI (13.4 ml_, 27 mmol) (or 2M H2SO4, 6.7ml, 13mmol) was added followed by butyraldehyde (6.42 g, 89 mmol). Stirring was continued at 60 °C (e.g.for 3 hours). After this time the heating block was turned off and the mixture was stirred overnight at room temperature. After this time, the reaction mixture was neutralised to pH 7 using dilute ammonia solution (or sodium hydroxide) and the reaction product was precipitated by dropwise addition of the reaction mixture to an excess of acetone (4 litres total). The precipitate was then filtered off and dried in a vacuum oven at 40 °C overnight.

It is also possible to use the reaction mixture directly, optionally after neutralisation of the excess HCI with a suitable alkali such as sodium hydroxide. The reaction mixture may be diluted down to a suitable viscosity to enable, for example, spraying coating and further optional components may be added such as inorganic salts or surfactants or other as described herein.

Other PVOH grades may be made using the same general synthetic method described above for Synthesis Example 1 . Amphiphilic Graft Co-Polymer Synthesis Examples

Synthesis Example 2: Reaction of polybutadiene-graft-maleic anhydride Lithene N4- 5000-5MA grade with Jeffamine M2070 (Preparation of AGC1 ) in a reaction flask

PBD-g-MA (200 g, Polybutadiene-graft-maleic anhydride obtained from Synthomer, Lithene N4-5000-5MA grade) having an average molecular weight of approximately 5,750 Da was weighed out and added to a reaction flask with a 0.5 L capacity, equipped with an overhead stirrer. A flow of nitrogen gas was passed through the vessel, which was then heated to 150 °C using an oil bath. Stirring of the molten mixture then commenced and Jeffamine M2070 poly(ether monoamine) (144 g, purchased from Huntsman), having an average molecular weight of 2,000 Da was added over 45 minutes via a dropping funnel. The reaction mixture was maintained at 150 °C for a total of approximately 6 hours with stirring. Following this it was allowed to cool and was then dispensed into a glass container.

Synthesis Example 3: Reaction of polybutadiene-graft-maleic anhydride Lithene N4- 5000-15MA grade with Jeffamine M2070 (Preparation of AGC2)

PBD-g-MA (200 g, Polybutadiene-graft-maleic anhydride obtained from Synthomer, Lithene N4-5000-15MA grade) having an average molecular weight of approximately 5,750 Da was weighed out and added to a reaction flask with a 1 .0 L capacity, equipped with an overhead stirrer. A flow of nitrogen gas was passed through the vessel, which was then heated to 150 °C using an oil bath. Stirring of the molten mixture then commenced and Jeffamine M2070 poly(ether monoamine) (401 .1 g, purchased from Huntsman), having an average molecular weight of 2,000 Da was added over 45 minutes through a dropping funnel. The reaction mixture was maintained at 150 °C for a total of approximately 6 hours with stirring.

Following this it was allowed to cool and was then dispensed into a glass container.

PARTICLE MANUFACTURE AND COATING METHOD Examples

Granulation

Granulation Example 1

1 . The SPC source is loaded into the mini chopper (high shear blender). The grade of SPC employed is not critical and may include coated or uncoated types or a mixture thereof.

2. PVB solution (which may or may not contain salt and/or surfactant), of a

concentration up to about 20% solids content, is added to the solid SPC whilst mixing.

3. TAED is then blended into the mixture to ensure homogeneity, followed by further addition of PVB 10-98 solution whilst continuing to blend.

4. After a satisfactory particle size has been achieved for the agglomeration the material is removed from the mixer and may be dried. Any effective drying method may be used and may include fluid bed drying, vacuum drying or oven drying.

Granulation Example 2

Using coated SPC

Protocol A

1 . The SPC source is coated (prior to co-granulation with TAED), (most likely via a spray coating method) where PVB 10-98 solution (which may or may not contain salt and/or surfactant) can be, but is not limited to, the coating solution.

2. This pre-coated particle is then loaded into a mixer where the TAED is blended with it to ensure a homogenous distribution of TAED throughout the co-granule.

3. A further solution of PVB 10-98 (which may or may not contain salt and/or surfactant) is then applied whilst mixing to promote adhesion of the TAED to the co-granule.

4. After a satisfactory particle size has been achieved for the agglomeration the material is removed from the mixer and may be dried. Any effective drying method may be used and may include fluid bed drying, vacuum drying or oven drying. Protocol B

1 . The SPC source is coated (prior to co-granulation with TAED), (most likely via a

spray coating method) where PVB 10-98 solution (which may or may not contain salt and/or surfactant) can be, but is not limited to, the coating solution.

2. This pre-coated particle is then loaded into a mixer where the TAED/ PVB 10-98

(which may or may not contain salt and/or surfactant) slurry is blended with it to ensure a homogenous distribution of TAED throughout the co-granule.

3. After a satisfactory particle size has been achieved for the agglomeration the material is removed from the mixer and may be dried. Any effective drying method may be used and may include fluid bed drying, vacuum drying or oven drying.

Granulation Example 3

Using coated SPC

Protocol A

3. A further solution of PVB 4-98 (which may or may not contain salt and/or surfactant) is then applied whilst mixing to promote adhesion of the TAED to the co-granule.

Protocol B

spray coating method) where PVB 10-98 solution (which may or may not contain salt and/or surfactant) can be, but is not limited to, the coating solution. 2. This pre-coated particle is then loaded into a mixer where the TAED/ PVB 4-98 (which may or may not contain salt and/or surfactant) slurry is blended with it to ensure a homogenous distribution of TAED throughout the co-granule

Granulation Example 4

Using coated SPC

Protocol A

1 . The SPC source is coated (prior to co-granulation with TAED), (most likely via a spray coating method) where PVB 4-98 solution (which may or may not contain salt and/or surfactant) can be, but is not limited to, the coating solution.

Protocol B

spray coating method) where PVB 4-98 solution (which may or may not contain salt and/or surfactant) can be, but is not limited to, the coating solution.

2. This pre-coated particle is then loaded into a mixer where the TAED/ PVB 4-98

(which may or may not contain salt and/or surfactant) slurry is blended with it to ensure a homogenous distribution of TAED throughout the co-granule. 3. After a satisfactory particle size has been achieved for the agglomeration the material is removed from the mixer and may be dried. Any effective drying method may be used and may include fluid bed drying, vacuum drying or oven drying.

Granulation Example 5

Using an addition of spray dried PVB

2. PVB 10-98 powder (which may or may not contain salt and/or surfactant), is blended with the solid SPC to ensure a homogenous distribution.

3. Water is then added to "wet out" the PVB and promote barrier formation.

4. TAED is then blended with the mixture, followed by a small amount of water to aid adhesion of the TAED to the PVB.

5. After a satisfactory particle size has been achieved for the agglomeration the material is removed from the mixer and may be dried. Any effective drying method may be used and may include fluid bed drying, vacuum drying or oven drying.

Granulation Example 6

Using coated SPC

2. This pre-coated particle is then loaded into a mixer where the TAED/ PVB 4-88 (which may or may not contain salt and/or surfactant) slurry is blended with it to ensure a homogenous distribution of TAED throughout the co-granule.

Granulation Example 7

Using an addition of an emulsion of wax/AGC in addition to PVB

1 . The SPC source is loaded into the mini chopper (high shear blender). The grade of SPC employed is not critical and may include coated or uncoated types or a mixture thereof where an emulsion of wax/amphiphillic graft copolymer can be, but is not limited to, the coating solution.

2. An emulsion of wax/amphiphilic copolymer is added whilst mixing.

3. A solution of PVB (which may or may not contain salt and/or surfactant) is then applied whilst mixing to promote adhesion of the TAED to the co-granule.

Responsiveness of polymer binder Example 8

The following example describes the response of the PVB polymer with salt to the ionic strength environment the polymer finds itself in. This example is able to show that sodium percarbonate is fully protected and does not release any peroxide when it is encapsulated with the binder polymer PVB and it is placed into an environment of high ionic strength.

Particles of sodium percarbonate (Oxyper SCM - ex Solvay - 500-1000 micron diameter) were coated with a solution of the PVB polymer (Poval 10-98 - synthesised as given in example 1 above to have a degree of substitution of butyraldehyde equal to 8%) together with the salt, sodium sulphate (anhydrous). The feedstock polymer solution was made up in water to a total solids content of 5%: the solids of which were composed of 90% PVB/10% sodium sulphate. Coating was achieved using a standard fluid bed methodology utilising a bottom spray 'Wurster column' arrangement: the product temperature was maintained at around 40 °C during the coating process. A number of samples were produced having coating levels of polymer/salt equivalent to 10% or 20% of the total mass of the final coated particle.

The polymer/salt coated particles were placed into solutions of water containing L-glutamic acid Ν,Ν-diacetic acid, tetra sodium salt (GLDA) sold under the brand name Dissolvine (Akzo Nobel). GLDA is an effective means by which an aqueous solution having a representative ionic strength may be prepared. GLDA is also a material, known as a builder, which is commonly found in laundry, general cleaning and dishwash products.

Solutions representing 20%, 40% and 65% GLDA concentration (respectively having calculated ionic strengths (I) of 5.696M, 1 1 .393M and 18.514M) were produced. To each of these solutions (100mL) was added 0.2g of the PVB/salt polymer coated sodium percarbonate (coating levels 10% or 20%) and the resulting mixture stirred using an overhead stirrer at its slowest setting. The mixtures were maintained at 30 °C and samples of the solution were taken at 20 minutes which were analysed, using a standard iodometric titration, for the presence of peroxide. Non polymer coated samples of SPC were also tested in this way. The results tabulated below show that non-coated SPC releases peroxide at all of the ionic strengths investigated. In the case of the PVB/salt polymer coated SPC it can be seen that no release of peroxide is evident for solutions of 40% and 65% GLDA (calculated ionic strength solutions of 1 1 .393M and 18.514M respectively) and coating levels of 10% or 20% at those ionic strengths. In contrast at the lowest concentrations of GLDA used (20%, calculated ionic strength of 5.696M) both the 10% and the 20% PVB/salt coated SPC particles released peroxide within the 20 minutes. This experiment showing that the applied PVB/salt coatings are responsive to the ionic strength of the media in which they are placed and that, in this case, an ionic strength below 5.696M was not sufficient to maintain an effective barrier coating for 10% and 20% coated particles whilst an ionic strength of above 1 1 .393M was sufficient to maintain a fully effective barrier for particles with 10% and 20% PVB/salt coatings. This thereby demonstrating the dilution trigger response of the PVB/salt coating. Release of peroxide at 20 minutes

Full Granulation Example 9

This method details the full procedure to produce a composite of SPC and TAED. Clearly the values and masses of the given materials may be varied so as to, for example, have varying ratios of SPC:PVB:TAED. This method here described outlines the general method employed.

Key Stages

1 . Preparation of the polymer/salt solution

2. Preparation of the TAED-polymer slurry

3. Formation of the wet agglomerate through blending of the TAED-polymer slurry with the SPC core particles

4. Drying of the wet agglomerate

Equipment

• Kenwood kitchen blender grade FPP220 Multipro Compact mixer - Formation of the wet agglomerate

• Aeromatic Fielder Strea 1 :Fluid bed dryer - Drying of the granulate Materials

• Pre-coated SPC core particle (Coated to 3% with PVB/salt feedstock solution - see preparation of polymer in salt solution below - the same solution was used for coating the SPC particles and as the binder in the following granulation) • Revolymer polymer solution (See Synthesis Example 1 above)

• TAED powder (ex. Warwick Chemicals)

1. Preparation of the polymer in salt solution

Synthesis of 20 % PVB solution as given above in Synthesis Example 1 .

For this process, it was more favourable to form the agglomerate with a relatively high solids content polymer solution. The PVB polymer was prepared at an approximate 20% solids content, and then this was taken and diluted by half using a 0.16 M sodium sulfate salt solution in water to form a -10% polymer in 0.08M salt solution.

Typical composition:

2. Preparation of the TAED-polymer slurry

The previously prepared polymer solution was added to a glass jar. TAED was added to the polymer solution in small portions over a period of 20 mins, each aliquot addition was followed by mixing of the TAED into the polymer solution by hand using a spatula; this was to ensure that there were no residual large lumps of TAED within the slurry. The slurry was always stirred immediately before the agglomeration step to ensure a uniform addition to the SPC particles.

Typical composition:

The pre-coated SPC particles (coated to a loading of 3% PVB/salt using the feedstock solution described above) were added into a Kenwood blender. The TAED-polymer slurry was then added slowly whilst mixing at setting number 1 over a period of 1 min the process was stopped periodically to scrape the mixer bowl and blade to promote uniform mixing.

Typical composition:

4. Drying of the wet agglomerate

The resulting wet agglomerate was then dried using an Aeromatic Fielder Strea 1 at a bed temperature of approximately 50 °C for around 15-20 minutes at an air flow rate which ensured efficient fluidisation of the sample.

Data table; Example 10

Claims

1 . A composite particle comprising (i) discrete portions of at least one peroxide

generating bleach and (ii) discrete portions of at least one bleach activator, said discrete portions of peroxide generating bleach and bleach activator being separated from each other and encapsulated within a binder matrix, wherein the matrix comprises:

at least one water-soluble polymer; and

at least one ionic species,

2. The composite particle of claim 1 , wherein the at least one water-soluble polymer is a PVOH-based polymer.

3. The composite particle of claim 1 or 2, wherein the at least one water-soluble

polymer is a PVOH-based polymer that has been modified by reaction with aldehydes, acetals, ketals, esters, epoxides, isocyanates, suitably reactive oligomers, polymers and/or aromatic compounds such as aromatic aldehydes.

4. The composite particle of any of claims 1 , 2 or 3, wherein the at least one water- soluble polymer is a PVOH-based polymer modified by reaction with an aldehyde.

5. The composite particle of claim 4, wherein the aldehyde is a mono-aldehyde.

6. The composite particle of claim 4 or 5, wherein the degree of substitution of the

PVOH-based polymer is about 4 to 12%.

7. The composite particle of claim 4, 5 or 6, wherein the degree of substitution of the PVOH-based polymer is about 8%.

8. The composite particle of any preceding claim, wherein the peroxide generating

bleach is SPC.

9. The composite particle of any preceding claim, wherein the bleach activator is TAED.

10. The composite particle of any preceding claim, wherein the at least one ionic species is a salt or a surfactant.

1 1 . The composite particle of any preceding claim, wherein the at least one ionic species is sodium sulphate.

12. The composite particle of any preceding claim, wherein the ionic species is present in an amount of 0.1 to 40% based on the total weight of the binder matrix.

13. The composite particle of any preceding claim, wherein the water-soluble polymer is present in an amount of 60 to 99.9% based on the total weight of the binder matrix.

14. The composite particle of any preceding claim, wherein the binder matrix is present in an amount of 0.1 to 15% based on the total weight of the composite particle.

15. A process for the preparation of a composite particle as claimed in any preceding claim, the process comprising the steps of:

a) providing discrete portions of either:

i) at least one peroxide generating bleach, or

ii) at least one bleach activator,

b) contacting the discrete coated portions of step a) with a mixture of:

iii) water, at least one water-soluble polymer, and at least one ionic species; and iv) either at least one peroxide generating bleach or at least one bleach

activator;

c) mixing the product of step b); and

d) isolating the composite particles;

with the proviso that

- the at least one bleach activator may feature in only one of steps a) and b).

16. The process of claim 15, wherein step a) comprises providing discrete portions of at least one peroxide generating bleach, wherein the discrete portions are each coated with a binder matrix comprising at least one water-soluble polymer as defined in any of claims 2-7, and at least one ionic species as defined in either of claims 10 or 1 1 .

17. The process of claim 15 or 16, wherein step b) comprises contacting the discrete coated particles of step a) with:

i) water, at least one water-soluble polymer, and at least one ionic species, and ii) at least one bleach activator.

18. The process of any of claims 15, 16 or 17, wherein the at least one peroxide generating bleach is sodium percarbonate (SPC).

19. The process of any of claims 15 to 18, wherein the at least one bleach activator is TAED.

20. A consumer product comprising a composite particle as claimed in any of claims 1 to 14.

21 . The consumer product of claim 20, wherein the consumer product is a cleaning, bleaching or sterilizing product.