WO2012084061A1

WO2012084061A1 - Fragrance granules for detergents

Info

Publication number: WO2012084061A1
Application number: PCT/EP2010/070704
Authority: WO
Inventors: Norbert A. Braun; Tee Yong Tan
Original assignee: Symrise Ag
Priority date: 2010-12-23
Filing date: 2010-12-23
Publication date: 2012-06-28
Also published as: CN103249826A; CN103249826B

Abstract

The present invention relates to encapsulated fragrances, products comprising such encapsulated fragrances and corresponding methods of manufacture and uses. The particles comprise a) a substance to be released, b) a carrier, wherein said carrier is a hydrotrope which is a solid at 20°C, c) a shell comprising hydrophobic shell material having a melting point of at most 65°C, preferably of 40-60°C, and d) a disintegrator material comprised in the shell for disintegrating the shell after immersion in water.

Description

Fragrance granules for detergents

The present invention relates to encapsulated fragrances, products comprising such encapsulated fragrances and corresponding methods of manufacture and uses.

In the field of laundry agents, fragrances are used to impart a clean olfactory impression on washed materials. During manufacture of such laundry compositions, care must be taken to avoid harsh conditions which would chemically modify the fragrances to prevent a loss of fragrance quality and intensity. It has therefore been tried to protect fragrances by surrounding them with a protective material, e.g. a solid carrier or an encapsulating shell.

For example, US 5336665 discloses perfume particles adapted for use in laundry detergent or bleaching compositions to allow the intensity of perfume in a composition to be controlled, suppress unwanted perfume loss and to act as a delivery means to fabric, skin or other articles. The perfume is absorbed into a hydrophobic porous inorganic carrier particle, e.g. by spraying. The inorganic carriers are rendered hydrophobic, e.g. by thermal treatment at a temperature between 500-1.000°C for up to three hours. US 5500223 relates to a method of encapsulation of a hydrophobic liquid. An emulsion is first made with silica, a fragrance and water. A gelation process on the emulsion is then accomplished by acidification with hydrochloric acid.

WO 99/38945 A1 discloses water dispersible granulates finally divided in and encapsu- lated by a water soluble or water dispersible solid organic matrix. An emulsion of organic matrix with perfume and water is subjected to a drying process at a temperature up to 150°C.

US 6932982 relates to a granular delivery system comprising a flavour or fragrance distributed throughout a matrix of agar. A mixture of sucrose, maltodextrin and water is added to an agar solution and the mixture is heated to a temperature of 123°C. The fragrance and emulsifier is added to the concentrated syrup to form a uniform melt, which is then extruded under pressure and dried.

EP 816484 A2 relates to a perfume carrier for use in detergent compositions. The perfume is adsorbed onto inorganic carriers and then added to a molten high-molecular weight polyethylene glycol by mixing or spraying of the polyethylene glycol and perfume onto the solid inorganic carriers. The temperature needed to maintain the high-molecular weight polyethylene glycol in a liquid state is in the range of 60-80°C.

US 7485610 is similar to EP 816484 insofar that a fragrance is heated to dissolve it in a mixture of solid fatty alcohols, fatty acids, fatty alcohol ethoxylate and/or polyethylene glycol. The mixture is then solidified and can be applied e.g. in soaps, detergents and fabric softeners.

Despite these attempts, the problem of protecting fragrances is not satisfactorily solved so far. Particularly disadvantageous is that according to prior art, fragrances frequently have to be heated for a substantial period of time. Also, the substances used for encap- sulation and the corresponding processes frequently are considered too expensive, particularly in cost-sensitive markets.

Also, the problem remains that fragrances in detergent compositions frequently need to be attached to the washed article to impart a long-lasting impression of freshness and cleanliness. However, due to the presence of cleaning substances and particularly deter- gents in laundry compositions such attachment is very difficult to achieve. As the cleaning substances of laundry compositions are basically chosen to remove everything from an article to be washed that is not already firmly attached thereto, they effectively counteract any potential attachment of fragrances to articles to be washed. It is therefore frequently tried to increase the concentration of fragrances in laundry compositions to maintain a minimum amount of attached fragrances even though most of the fragrances will be washed away by the cleaning components. However, increasing the concentration of fragrances in laundry compositions strongly affects the price of such compositions. Also, it is generally considered not enough merely to attach fragrances to an article. Instead, it is required that the fragrances after drying do not immediately evaporate but leave a long- lasting impression.

However the present invention is not limited to encapsulating fragrances. Instead, the invention generally aspires to provide means for stabilizing an active substance, particularly under laundry conditions.

According to the invention, there is thus provided a release particle, comprising a) a substance to be released, preferably a fragrance,

b) a carrier, wherein said carrier is a hydrotrope being a paste or solid at 20°C, c) a shell comprising hydrophobic shell material having a melting point of at most 65°C, preferably of 40-60°C (melting points of 15°C - 20°C denotes that the material would be at liquid state at room temperature), and

d) a disintegrator material comprised in the shell for disintegrating the shell after immersion in water.

According to the present invention it has been found that by using a hydrotrope as a carrier for one more active substances, particularly one or more fragrances, it is possible to protect these from deleterious effects of heat which is otherwise necessary for encapsulation and/or spray-drying. This works particularly well in combination with a shell material having a melting point of at most 65°C. These melting temperatures in combination with the hydrotrope as a carrier allow to encapsulate substances to be released and particularly fragrances by avoiding harsh temperature conditions. Particularly, fragrances and other substances adsorbed on the hydrotrope carrier do not have to be exposed for prolonged periods of time to a high-temperature encapsulation material; instead, the comparatively low-melting shell material can cool down rapidly upon contact with the carrier. Also the combination of a hydrotrope and a low-melting shell material allow to avoid chemically aggressive encapsulation methods, e.g. sol-gel-processes requiring a drastic shift in pH to achieve solidification of a shell material. It is particularly advantageous that the release particles of the present invention can be prepared, if so required, in the absence of water. Preferred methods of producing release particles of the present invention are described later together with further advantages of such methods.

The release particles of the present invention are particularly adapted to laundry conditions by including a disintegrator material in the hydrophobic shell. The disintegrator material allows to rupture or puncture the shell after contact with water such that the active substance, e.g. a fragrance or fragrance mixture, can also get into contact with water, e.g. for dissolving therein or reacting with water or a compound dissolved therein.

By selecting the disintegrator material it is possible to adjust the resistance of the release particle against water. Thus, the release particles of the present invention are particularly adapted to release the substance (e.g. fragrance) after a pre-selected period of time after immersion of the particle in water. Thus, it is possible to delay release of the substance and particularly of the one or more fragrances during a laundry process for a substantial time, such that fragrances or other active substances are released close to the end of the laundry process. Typically, at the end of a laundry process the articles to be washed are rinsed with water to remove or reduce the amount of detergents adsorbed on the articles. Thus, by delaying release of the substance and particularly of a fragrance exposition of such substance to harsh detergent conditions can be avoided or reduced. It will therefore be easier to attach the active substance to the article to be washed or to prevent destruction or removal of the substance by detergents and unfavorable laundry conditions, e.g. a high pH value.

For practical purposes the disintegrator material will be a water-soluble material. The disintegrator material therefore allows to be removed from the shell upon contact with water, thereby leaving vacancies or channels potentially reaching to the hydrotrope carrier. Also, vacancies left by removal of the disintegrator material from the shell by contact with liquid water can weaken or destabilize the shell such that the release particle can be ruptured or cracked during typical laundry conditions. The invention, however, is not limited to a particular mode or action of the disintegrator material; it is sufficient that the disintegrator material allows to adjust the time for release of the active substance after immersion of the release particle in liquid water. Also for practical purposes, the water-soluble disintegrator material will be solid or a paste at 20°C. This ensures that the disintegrator material will not leak out or evaporate from the release particle under dry conditions, i.e. without exposition to liquid water.

The hydrophobic shell material preferably has a melting point of 35- 65°C and even more preferably of 40-60°C. It is thus sufficient to heat the preferred shell material to 60°C or, for the more preferred shell material, to at most 60°C, to achieve liquefaction of the shell material of sufficient degree to allow encapsulation of the carrier material e.g. by spraying the shell material onto granules or particles of the carrier.

For preferred release particles of the present invention, the total amount of the substance to be released is at most 40 wt.-% of the amount of hydrotrope carrier, and preferably is 5 to 10 wt.-%. It has been found that for release particles of the present invention fragrances and other active substances to be released can be efficiently adsorbed on the hydrotrope, thereby shielding the substance to be released from harsh encapsulation conditions. The ratio of total amount of hydrophobic shell material and disintegrator material to the total amount of hydrotrope carrier and substance(s) to be released is at most 1 : 1 , preferably 1 :9 to 2:5. It has been found according to the present invention that only such a low amount of hydrophobic shell material and disintegrator material is required to effectively encapsulate the substance to be released and the hydrotrope carrier even in view of typical laundry conditions.

The carrier of a release particle of the present invention preferably is or comprises a hydrotrope selected from a salt, preferably a sodium salt, of benzene sulfonate, toluene sulfonate, xylene sulfonate, cumene sulfonate, cymene sulfonate, hydroxynaphthoate, hydroxynaphthalene sulfonate, ethylhexyl sulfate, and mixtures of two or more of these substances, and preferably is sodium xylene sulfonate and/or sodium toluene sulfonate. The hydrotropes are particularly suitable for adsorbing a substance to be released and particularly a fragrance of fragrance mixture even in the absence of water. The hydro- tropes, and particularly sodium xylene sulfonate and/or sodium toluene sulfonate, have furthermore been found to effectively protect adsorbed substances to be released, e.g. a fragrance or fragrance mixture, from deleterious effects of exposition to a mixture of molten hydrophobic shell material and disintegrator material. The disintegrator material of a release particle of the present invention preferably is selected from non-ionic surfactants, preferably polyoxyethylene ethers, and polyethylene glycol, the polyethylene glycol preferably having a molecular weight of at least 2000. It has been found that the selection of these materials allows to disintegrate a release particle of the present invention as described above, particularly by weakening its shell or forming pores and channels therein, under typical laundry conditions to delay release of a substance, e.g. a fragrance or fragrance mixture, to a predetermined period of time after immersion of the particle in water.

Further, the hydrophobic shell material of a release particle of the present invention preferably is selected from branched or straight, saturated or non-saturated C15-C24 fatty acids, and

fatty alcohols, and

esters thereof.

Particularly preferred hydrophobic shell materials are selected from cetyl alcohol, cetos- tearyl alcohol, stearyl alcochol, palmitic acid, stearic acid, myristic acid, ethylene glycol distearate, and ethylene glycol monostearate. With such preferred or particularly preferred hydrophobic shell material, encapsulation of the solid or paste-like hydrotrope can be achieved at low temperatures as described above, thereby limiting exposure of a substance to be released and particularly a fragrance or fragrance mixture adsorbed to the carrier.

It is particularly preferred that a release particle of the present invention should have a shell material comprising or consisting of a combination of a) preferred hydrophobic shell material, preferably cetyl alcohol, cetostearyl alcohol, stearyl alcohol, palmitic acid, stearic acid, myristic acid, ethylene glycol esters thereof and mixtures of these, and b) a disintegrator material selected from polyoxyethylene ethers and polyethylene glycol having a molecular weight of 2000-8000. Under typical laundry conditions components a) and b) and their respective mixing ratio can be chosen by the skilled person to delay release of the substance to be released for a selected period of time after immersion in water. Generally, the time for release increases with the molecular weight of polyethylene glycol and polyoxyethylene ether used as disintegrator material, as such materials will need higher temperatures and longer time to dissolve in water. Also, a higher amount of and a longer chain length of C15-C24 fatty acids, fatty alcohols and esters of such fatty acids and/or fatty alcohols also require longer exposition to water and/or higher laundry temperatures before the contents of the particles are released. Particularly preferred exam- pies of combinations are described hereinafter.

The substance to be released preferably is a fragrance or mixture of two, three or more fragrances. The fragrance compounds or perfumes for use in this invention may be any fragrance compounds or perfumes known to the art, in particular those described in S. Arctander, Perfume and Flavor Chemicals, private publishing house, Montclair, N.J., 1969 and Surburg, Panten, Common Fragrance and Flavor Materials, 5th Edition, Wiley- VCH, Weinheim 2006, preferably those explicitly mentioned in US 2008/0070825. It is a characteristic of this invention that an unusually broad range of fragrance compounds or perfumes may be used. Examples include digeranyl succinate, dineryl succinate, geranyl neryl succinate, geranyl phenylacetate, neryl phenylacetate, geranyl laurate, neryl lau- rate, di(citronellyl) maleate, dinonanyl maleate, diphenoxyethyl maleate, di(3,7-dimethyl- 1-octanyl) succinate, di(cyclohexylethyl) maleate, di(phenylethyl) adipate, 7-acetyl- 1 ,2,3,4,5,6,7,8-octahydro-1 , 1 ,6,7-tetramethyl naphthalene, ionone methyl, ionone gamma methyl, methyl cedrylone, methyl dihydrojasmonate, methyl 1 ,6,10-trimethyl-2,5,9- cyclododecatrien-1-yl ketone, 7-acetyl-1 , 1 , 3,4,4, 6-hexamethyl tetralin, 4-acetyl-6-tert- butyl-1 , 1 -dimethyl indane, para-hydroxy-phenyl-butanone, benzophenone, methyl beta- naphthyl ketone, 6-acetyl-1 , 1 ,2,3,3,5 hexamethyl indane, 5-acetyl-3-isopropyl-1 , 1 ,2,6- tetramethyl indane, 1-dodecanal, 4-(4-hydroxy-4-methylpentyl)-3-cyclohexene-1- carboxaldehyde, 7-hydroxy-3,7-dimethyl octanal, 10-undecen-1-al, isohexenyl cyclohexyl carboxaldehyde, formyl tricyclodecane, condensation products of hydroxycitronellal and methyl anthranilate, condensation products of hydroxycitronellal and indol, condensation products of phenyl acetaldehyde and indol, 2-methyl-3-(para-tert-butylphenyl)- propionaldehyde, ethyl vanillin, vanillin, heliotropin, hexyl cinnamic aldehyde, amyl cin- namic aldehyde, 2-methyl-2-(para-iso-propylphenyl)propionaldehyde, coumarin, decalac- tone gamma, cyclopentadecanolide, 16-hydroxy-9-hexadecenoic acid lactone, cyclohex- adecanone, 8-cyclohexadecenone, 1 ,3,4,6,7,8-hexahydro-4,6,6,7,8,8- hexamethylcyclo- penta-gamma-2-benzopyrane, beta-naphthol methyl ether, ambroxane, dodecahydro- 3a,6,6,9a-tetramethyinaphtho[2,1 b]furan, cedrol, 5-(2,2,3-trimethylcyclopent-3-enyl)-3- methylpentan-2-ol, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol, caryophyl- lene alcohol, tricyclodecenyl propionate, tricyclodecenyl acetate, benzyl salicylate, cedryl acetate, para-(tert-butyl) cyclohexyl acetate, essential oils, resinoids, and resins from a variety of sources including but not limited to orange oil, lemon oil, patchouli, Peru balsam, Olibanum resinoid, styrax, labdanum resin, nutmeg, cassia oil, benzoin resin, coriander, lavandin, and lavender, phenyl ethyl alcohol, terpineol, linalool, linalyl acetate, geraniol, nerol, 2-(1 , 1-dimethylethyl)cyclohexanol acetate, benzyl acetate, orange ter- penes, eugenol, diethylphthalate, and combinations thereof.

According to the invention, there is further provided a washing composition comprising a detergent and a release particle according to the invention. Such washing composition allows to realize the advantages described above in view of the release particles of the present invention. Preferably, the washing composition comprises an anionic detergent. Further preferably, the washing composition comprises both one or more anionic and one or more nonionic detergents.

Further according to the invention, there is provided a method of manufacturing a release particle of the present invention, comprising the steps of:

(i) absorbing a substance to be released to a hydrotrope to obtain a core particle,

(ii) heating and mixing a hydrophobic shell material and a disintegrator material to obtain a liquid coating mixture,

(iii) coating the core particle of step (i) with the liquid coating mixture of step (ii) to obtain a release particle. The liquid coating mixture used for coating in step (iii) preferably has a temperature of at most 100°C, preferably at most 80°C. Such temperatures are sufficient for coating of the core particles due to the low melting point of the hydrophobic shell material as described above. Also as indicated above, the coating mixture is either completely liquefied or is at least liquefied so far that it can be sprayed via a nozzle to coat the core particles. The coated particles are of a dimension preferably not exceeding 1 cm in length, breadth or weight.

The invention is further described by some examples. However, the examples are not to be construed as limiting the scope of the claims or of the present invention in general. Unless stated otherwise, all percentages are by weight. Example 1

An experiment is made using the following formulation with Stearyl Alcohol as the sole encapsulating ingredient.

The sodium xylene sulfonate in pellets is grounded so that the resulting powder and granulates have a larger surface area to adsorb the fragrance (Part A). The molten stearyl alcohol (Part B) is added to the fragrance-adsorbed sodium xylene sulfonate to form a slurry. Continuous stirring of this mixture produces granulates as the slurry mixture hardened as the temperature falls below the melting point (60°C) of stearyl alcohol.

A water-solubility test for these granulates is conducted with 1 gram of granulates in 1 litre of water containing 5 grams of a regular detergent powder. After one hour of continuous stirring on a mechanical stirrer without heat, the fragranced-granulates remained practically insoluble in the detergent solution. Therefore, a detergent solution in a cold- water wash protocol would not be able to disintegrate stearyl alcohol-coated granulates to release the fragrance.

Example 2

An experiment is conducted using the following formulations with Stearyl Alcohol and Polyethylene Glycol M.W. 8000.

The fragrance is adsorbed onto sodium xylene sulfonate and mix well (Part A) as per example 1. The molten blend of stearyl alcohol, polyethylene glycol and oil-soluble dye (Part B) is added to the fragrance-adsorbed sodium xylene sulfonate to form a slurry. Continuous stirring of this mixture produces granulates as the slurry mixture hardened as the temperature falls below the melting point (60°C) of stearyl alcohol. The fragranced-granulates of Formulation C is shown to have a harder texture than the fragranced-granulates of Formulation B due to a higher content of stearyl alcohol. A water-solubility test as per example 1 is conducted. After 1 hour, almost all the fragranced-granulates of both formulations has disintegrated. Therefore, a water-soluble component is needed as an aid for the disintegration of the fragranced-granulates to release the fragrance.

Example 3

An experiment is conducted using the following formulations comparing a 5% and 10% fragrance loading on the hydrotrope, sodium xylene sulfonate.

o a par s

The fragranced-granulates are formed as per the procedures in Example 1 and 2.

In the water-solubility test given in the previous examples, the fragranced-granulates have not completely disintegrated after 1 hour. The reduction of the polyethylene glycol against the previous example, showed that the rate of disintegration can be manipulated by the amount of water-soluble component.

Example 4

An experiment is conducting using the following formulations with stearyl alcohol and a nonionic surfactant as the water-soluble component.

The fragranced-granulates are formed as per the procedures in Example 1 and 2.

In the water-solubility test given in the previous examples, the fragranced-granulates of Formulation F has almost complete disintegration compared to the fragranced-granulates of Formulation G. Therefore, the rate of disintegration can also be adjusted with surfac- tants having different HLB values or simply different degree of water-solubility.

Example 5

An experiment is made using the following formulation with ethylene glycol distearate as the water-insoluble or hydrophobic component.

The fragranced-granulates are formed as per the procedures in Example 1 and 2.

In the water-solubility test given in the previous examples, the fragranced-granulates of Formulation H has similar rates of disintegration as the fragranced-granulates of Formulation G. Therefore, the hydrophobic component did not exert as much influence in the rate of disintegration as the water-soluble component. Example 6

A machine wash is conducted with the fragranced granulates of Formulations C, D, E, F, G and H in a regular detergent powder.

Detergent powder formulations %

Unperfumed 98.55 98.55 97.15 97.15 97.15 97.15 detergent powder

C 1.4

D 1.4

E 2.8

F 2.8

G 2.8

H 2.8

Quick Flash 0.05 0.05 0.05 0.05 0.05 0.05

(Fragrance)

Total 100 100 100 100 100 100

A control is prepared by having only neat fragrance (Quick Flash) at 0.15% in the detergent powder.

As the fragranced-granulates of Formulations C and D has a fragrance-loading of 10% on the hydrotrope, they are dosed at 1.4% in the detergent powder to give a fragrance load of 0.1 %. The Formulations of E, F, G and H has a fragrance-loading of 5% on the hydro- trope, therefore, they are dosed at 2.8% in the detergent powder to give a fragrance load 0.1 %. The total fragrance load on the detergent powder is 0.15% with a free-fragrance load of 0.05%. The total fragrance load is set lower than 0.2% so that differences in performance attributed to the fragranced-granulates can be better evaluated olfactively.

The laundry load is 3 kg and the wash cycle consists of 1 wash stage and 2 rinse stages. There is a drain and spin stage between the wash and individual rinse stages. The wash cycle (cold water wash) is completed in approximately one hour. The amount of detergent powder used is 25 grams per trial.

Evaluation results

After-rinsed Dried overnight

Control Perceivable Not detectable

C Weakly-perceived Not detectable

D Perceivable Weakly-perceived

E Strong Perceivable

F Perceivable Not detectable

G Perceivable Perceivable

H Perceivable Weakly-perceived Control has 0.15% fragrance-loading on the detergent powder. There are no fragranced- granulates.

Formulation C has a 10% fragrance-loading on the hydrotrope with 24 parts of Stearyl Alcohol against 16 parts of Polyethylene Glycol. Formulation D has a 10% fragrance-loading on the hydrotrope with 28 parts of Stearyl Alcohol against 12 parts of Polyethylene Glycol.

Formulation E has a 5% fragrance-loading on the hydrotrope with 28 parts of Stearyl Alcohol against 12 parts of Polyethylene Glycol.

Formulation F has a 5% fragrance-loading on the hydrotrope with 28 parts of Stearyl Alcohol against 12 parts of Ceteareth-12.

Formulation G has a 5% fragrance-loading on the hydrotrope with 28 parts of Stearyl Alcohol against 12 parts of Steareth-2.

Formulation H has a 5% fragrance-loading on the hydrotrope with 28 parts of Ethylene Glycol Distearate against 12 parts of Steareth-2. Analysis of results

Control:

It is not surprising that no fragrance is detectable in the dried stage olfactively at the low dosage of 0.15%. At a low fragrance dosage, any free fragrance adhering to the fabrics after the entire wash cycle would be minimal and not expected to have an impact on the dried fabrics.

Formulation C:

The fragrance on the after-rinsed fabrics had been weakly-perceived. In this respect, the formulation has performed below the control. As the after-rinsed stage showed that the fragrance performance is weak, it is not surprising that no fragrance is detectable olfac- tively in the dried stage. Formulation D:

Formulation D performed on par with the control in the after-rinsed stage and slightly better in the dried stage with the fragrance still weakly-perceived olfactively.

Comparison of Formulation C and D against Control: Formulation C has a higher water-solubility than Formulation D as it has a higher amount of the water-soluble component, polyethylene glycol. The presence of the fragrance olfactively in the dried fabrics indicate that there is a slightly higher level of deposition than the control or the fragranced-granulates of Formulation C. Therefore, there is merit in delaying the release of the fragrance in the wash cycle particularly when the fragrance is released into the presence of the detergent actives.

However, Formulation C performed below the control despite having a lower water- solubility than the control. Therefore, the mechanics of the wash cycle has a role. There is a real possibility that some fragranced-granulates are lost in the drain stage and this possibility would apply also to the fragranced-granulates of Formulation D. Assuming that amount of fragranced-granulates lost is similar between Formulation C and Formulation D in the wash cycle, the amount of fragrance released into the wash cycle would be lower than the control of 0.15%.

The control releases 0.15% of fragrance into the wash stage in the presence of the detergent actives. A part of this 0.15% of fragrance would be lost to the detergent actives as emulsified material and to the drain stages as well. Therefore, only a fraction of this 0.15% of fragrance would be deposited onto the fabrics.

The fragranced-granulates of Formulation C has a lower water-solubility than the control so the release of the fragrance would be delayed towards middle or the end-stage of the wash stage in the presence of the detergent actives. A part of the fragrance released at this stage would be emulsified by the free detergent actives, that is, detergent actives not bound to other emulsified soils from the fabrics. It is expected that some fragranced- granulates are lost in the drain stages and are not available physically in the rinse stages to release the fragrance. As the performance of Formulation C is lower than the control in the after-rinsed stage, it is sufficed to suggest that a lower amount of fragrance had been deposited on the fabrics. Therefore, the cumulative amount lost by Formulation C to the detergent actives and the drain stages is more than the control.

Formulation D has a lower water-solubility than Formulation C and performed better olfactively than the control. As the fragrance is still perceivable in the dried fabrics as opposed to the control and Formulation C, there is a higher amount of fragrance deposited on the fabrics. Assuming that the amount of fragranced-granulates lost in the drain stages and not available physically in the rinse stages to release the encapsulated fragrance is similar for Formulation C and Formulation D since they are used in the same dosages in the detergent powder, the difference would lie in the amount lost as emulsified material to the detergent actives. The later release of the fragrance in the presence of the detergent actives compared to Formulation C resulted in a lower loss as emulsified material to the detergent actives. As such, a higher amount of fragrance is released in the rinse stages when the concentration of the detergent actives is considerably lower.

Formulation E: Formulation E performed better than the control, Formulation C and D in the after-rinsed stage and the dried stage indicating that there is a higher amount of fragrance deposited on the fabrics.

Formulation E is similar to Formulation D in terms of the amount and composition of the encapsulating material. However, the fragrance-loading on the hydrotrope is at 5% in- stead of 10% in Formulation D. Therefore, to represent 0.1 % of fragrance, the amount of fragranced-granulates in the detergent powder is 2.8% instead of 1.4% for Formulation D.

As the mechanics of the wash cycle had been discussed and would be similar for Formulation E and Formulation D, the difference would lie in the amount of fragranced- granulates lost in the drain stages. Each fragranced-granulate lost represent 5% of fra- grance for Formulation E and 10% of fragrance for Formulation D. If the number of fragranced-granulates lost is similar for Formulation E and Formulation D, cumulatively, Formulation D would have lost a higher amount of fragrance in the drain stages. As such, there will be a higher amount of fragrance deposited on the fabrics by Formulation E than Formulation D. In this respect, it is interesting to note that by lowering the fragrance-loading on the fragranced-granulate, there is a perceivable benefit in fragrance deposition on the fabrics. This is a deviation from the approach of prior art whereby encapsulation processes focused on increasing the fragrance-loading on the capsules usually in the range of 20% to above 40%. In the wash cycle, when a fragranced-capsule having a fragrance load of 20% - 40% is lost in the drain stage, it represents a loss of 20%-40% of this fragrance as opposed to the present invention when a fragranced-granulate has a fragrance-loading of 5% - 10%. Similarly, when a fragranced-capsule is designed to dissolve or disintegrate immediately in the presence of water, it releases the fragrance in the presence of the detergent actives and correspondingly, a higher amount would be emulsified by the detergent actives.

Formulation F:

Formulation F is similar to Formulation E with a 5% fragrance-loading on the hydrotrope but with water-soluble component of polyethylene glycol replaced with a nonionic, Cetea- reth-12. The performance is similar to the control and in part to Formulation C. Therefore, the mechanics of the wash cycle for the control and Formulation C can be applied to Formulation F.

Formulation G:

Formulation G is similar to Formulation F but with the nonionic, Ceteareth-12, replaced with another nonionic with a lower degree of water-solubility or lower HLB value, Stea- reth-2. The performance is better than Formulation F and the control with good olfactive appreciation in the after-rinsed and dry stages.

The mechanics of the wash cycle being the same, the difference is attributed to the use of a lower HLB nonionic which lowers the water-solubility of the fragranced-granulate. The lowered water-solubility delays the release of the fragrance towards the later part of the wash cycle as previously discussed.

Formulation H:

Formulation H is similar to Formulation G but the water-insoluble or hydrophobic component of Stearyl Alcohol replaced with Ethylene Glycol Distearate. The performance is similar to Formulation G, therefore, the change in the hydrophobic component did not affect its performance greatly in contrast to changes in the water-soluble component.

Example 7

An experiment to incorporate a cationic active is made according to the formulations below as per the procedures in Example 1 & 2.

As a control demonstrating the existence of anionic-cationic complexes in a detergent solution, two beakers with 1 litre of water are prepared. In one beaker, 5 grams of an unperfumed detergent powder with 1 % cationic, Rewoquat WE 15 is added. In the other beaker, a control with 5 grams of unperfumed detergent powder. The detergent powders in both beakers are dissolved by continuous stirring in a mechanical mixer at ambient temperature for 30 minutes. The detergent solutions are then allowed to stand at ambient temperature for two hours. At the end of this period, the insoluble builders such as zeolite are settled at the bottom of the beaker. A comparison of these two detergent solutions showed that the detergent powder with 1 % cationic active is considerably hazier and with more sedimentation at the bottom of the beaker than the control without the cationic active, cf. fig. 1.

A machine wash as per Example 6 is conducted with the formed granulates of Formulation PFC and Formulation FC in the same unperfumed detergent powder base used for the control experiment. Detergent Formulations:

The cationic active content in Detergent Formulation 1 is 0.1 % and in Detergent Formulation 2 is close to 1 %. Wash Test analysis:

Detergent Formulation 1

While the cationic content is low, there is a slight softness to the fabrics indicating the deposition of cationic onto the fabrics. There are no particles of anionic-cationic complexes on the fabrics. Detergent Formulation 2

The cationic content at close to 1 % in the formulation is similar to the control experiment demonstrating the presence of anionic-cationic complexes, therefore, the possibility of anionic-cationic complexes being formed in the wash cycle is higher than in Detergent Formulation 1. However, the washed fabrics did not show any presence of anionic- cationic complexes.

In a standard scenario, the fabric softener or fabric conditioner is added at the last rinse of the laundry cycle. This method prevents the cationic active from forming the anionic- cationic complexes as the level of anionic actives in the last rinse is significantly reduced. The formed granulates with the cationic active in Detergent Formulation 2 is in the pres- ence of the anionic actives at the main wash stage, however, its release from the formed granulates occurred at a later stage of the wash cycle when the level of anionic actives is reduced. Therefore, the cationic active is introduced at a later stage of the wash cycle as in the standard scenario and do not form the anionic-cationic complexes.

Detergent Formulation 3 The cationic content is approximately 3% in the formulation. The dosage of 3% cationic is comparable to the median dosage of a regular fabric conditioner or softener. The possibility of forming anionic-cationic complexes in the wash cycle is higher than in Detergent Formulation 1 and 2 due to its higher dosage of cationic active. However, the washed fabrics did not show any presence of anionic-cationic complexes. Therefore, the present invention showed that it is possible to delay the release of the cationic active at a higher dosage in the detergent powder.

Claims

Release particle, comprising

a) a substance to be released,

b) a carrier, wherein said carrier is a hydrotrope which is a solid at 20°C, c) a shell comprising hydrophobic shell material having a melting point of at most 65°C, preferably of 40-60°C, and

Release particle according to claim 1 ,wherein the total amount of the substance to be released is at most 40 wt.-% of the total amount of hydrotrope carrier, and preferably is 5-10 wt.-%.

Release particle according to claim 2, wherein the ratio of total amount of hydrophobic shell material and disintegrator material to the total amount of hydrotrope carrier and substance to be released is at most 1 :1 , preferably 1 :9 to 2:5.

Release particle according to claim 1 , 2 or 3, wherein the hydrotrope carrier is selected from a salt, preferably a sodium salt, of benzene sulfonate, toluene sulfonate, xylene sulfonate, cumene sulfonate, cymene sulfonate, hydroxynaphthoate, hydroxynaphthalene sulfonate, ethylhexyl sulfate, and mixtures of two or more of these substances, and preferably is sodium xylene sulfonate and/or sodium toluene sulfonate.

Release particle according to any of claims 1 to 4, the disintegrator material is selected from non-ionic surfactants, preferably polyoxyethylene ethers, and polyethylene glycol, preferably having a molecular weight of at least 2000.

Release particle according to any of claims 1 to 5, wherein the hydrophobic shell material is selected from branched or straight, saturated or non-saturated C15-C24 fatty acids, and

fatty alcohols, and

esters thereof.

7. Release particle according to any of claims 1 to 6, wherein the substance to be released is a fragrance .

8. Washing composition, comprising a detergent and a release particle according to any of claims 1 to 7.

9. Washing composition according to claim 8, wherein the detergent comprises an anionic detergent.

10. Method of manufacturing a release particle according to any of claims 1 to 7, comprising the steps of

(iii) coating the core particle of step (i) with the liquid coating mixture of step (ii) to obtain a release particle.

1 1. Method of claim 10, wherein in step (iii) the liquid coating mixture used for coating in step (iii) has a temperature of at most 100 °C, preferably at most 80°C.