WO1998002518A1 - Granulates of a perfumed product with controlled releasing, method of production and use in detergent compositions for dish washer - Google Patents

Abstract

The invention concerns novel granulates of a perfumed product with controlled releasing, their method of production and their use in detergents, more particularly in compositions for dish washing. The novel granulates of a perfumed product with controlled releasing are characterised in that they comprise a central core formed essentially of the perfumed product in powder form enclosed in a peripheral layer formed essentially by a coating agent in solid state at room temperature and capable of being modified when used in a dish washer, so as to release its perfume under of the rise in temperature, during the washing cycle.

Description

 GRANULFS OF A PERFUMED PRODUCT WITH CONTROLLED RELEASE.

THEIR PROCESS FOR OBTAINING AND THEIR USE IN DETERGENT DISHWASHER COMPOSITIONS.

The subject of the present invention is new granules of a perfumed product with controlled release, their process for obtaining as well as their use in detergency, more particularly in compositions intended for cleaning dishes. More specifically, the invention relates to detergent compositions for washing your dishes in the machine comprising a perfumed product, more particularly vanillin, the smell of which is revealed with a "delay" effect at the end of the washing phase.

The perfuming of dishwasher compositions must circumvent a certain number of difficulties and, as very frequently in the problems of detergent formulation, lead to a compromise sparing at the same time technical, economic and psychological imperatives.

The choice of fragrant notes intended for washing culinary instruments or dishes coming into contact with the mouth is delicate. These notes must be "food" in order not to shock the well-established cultural reflexes and habits. The most commonly accepted is the lemon scent. Mint is sometimes encountered, but floral, bouquet, lavender or other notes are generally to be avoided. In addition, detergents for dishwashers have an established reputation for aggressiveness, less justified with recent developments but nevertheless very real. In particular, it appears that risks of accidental ingestion by very young children exist (and have occurred in the past), and it is probably advisable not to increase the attraction which these products can exert vis-à-vis children by an aroma that can be compared to consumable products, for example, confectionery.

However, the preceding considerations will be qualified by referring to the safety packaging which has developed significantly in recent years, and which reduces the risks mentioned above.

On the other hand, a recognized problem in the field of automatic dishwashing is the appearance, during washing, of unpleasant odors or negative, which come from the chemical degradations undergone by soiling which are food remains of very diverse origins. These odors are caused by the alkaline attack of fats, retrograde residues by cooking, starchy foods, starches and vegetable proteins of various origins.

These odors can appear randomly depending on the nature of the dirt present, at the end of the washing phase, or when the dishwasher is opened if it takes place when the appliance is still hot. Their emission can also be facilitated or on the contrary reduced according to the technology and the quality of the dishwasher used.

In any case, the problem exists and solving it can allow a significant improvement in the user's perception of the dishwasher and the detergent.

The present invention, which consists in introducing into a detergent composition for dishwasher, solid, pulverulent or granular, a perfume manifesting itself with a delay effect at the precise moment of the washing cycle where unpleasant odors occur, can contribute to solving this problem. without creating any secondary inconvenience.

In addition, the surprise due to the delayed perception of the smell, along with perfuming the atmosphere of the kitchen during washing, can bring a positive psychological effect which can be valued in marketing terms.

A first object of the invention therefore consists of granules of a perfumed product with controlled release characterized in that they comprise a central core formed essentially of the perfumed product in pulverulent form surrounded by a peripheral layer formed essentially of a coating agent which is solid at room temperature and which can change under the conditions of use in a dishwasher, in order to release the perfume under the effect of the rise in temperature, during the washing cycle. Another subject of the invention consists of a detergent composition for a dishwasher comprising the granules of a perfumed product with controlled release.

Finally, another object of the invention consists in the use, as perfuming agents during washing in the dishwasher in detergent compositions, of at least granules as defined.

The granules of the invention therefore comprise a perfumed solid and a coating agent. For the choice of the scent note which is preferably vanilla, use is preferably made of vanillin and derivatives, available in powdered forms. The invention is not limited to vanillin and also applies to all aromatic aldehydes and derivatives and other perfumed products. In order for the perfume to be released, preferably, at the end of the washing cycle, use is made of a coating agent having characteristics such that they allow the release of the perfume.

A first embodiment of the invention consists in using a coating agent (or a mixture) which is fusible under the action of the rise in temperature.

Another mode is to choose one or more coating agents capable of dissolving and / or dispersing, under the action of the increase in temperature.

The desired perfumed odor is released "hot", that is to say at a temperature advantageously between 30 ° C and 70 ° C, preferably between 40 ° C and 60 ° C.

This release of odor at the appropriate and desired time is of course obtained by the gradual rise in the temperature of the water, during the washing phase. Most dishwashers accept cold water from the network and raise its temperature to around 60 ° C. The typical temperature profile for the various washing phases in a conventional household dishwasher most often corresponds to a first prewash operation with cold water, at a temperature varying from 5 ° C to 20 ° C, for a period about 5 to 15 min followed by the washing operation carried out with hot water, at a higher temperature, generally 45 - 60 ° C.

According to the first variant, use is made of a fusible coating agent allowing the release of the perfume, under the washing conditions.

Due to the temperature profile of the washing phase, it is noted that the coating agent will melt when the appropriate temperature is reached, releasing the encapsulated perfume.

According to the other mode, the delayed release of the perfumed product consists in carrying out a slow dissolution of the coating in order to release the perfume, conditioned by the rise in temperature.

The coating according to the invention has several advantages. It very strongly decreases (or even cancels) the perception of the odor emanating from the solid product when cold, and therefore avoids giving the detergent a smell which could be attractive because it has a food connotation. It isolates the perfume from the rest of the components of the detergent formulation (which are relatively active and aggressive, alkaline and / or oxidizing products) and thus contributes to ensuring the aging stability of the perfumed principle. By stability is meant chemical stability, fragrance stability and color stability.

The coating may also be accompanied by granulation of the initial powder, with an average diameter of the order of 300 to 700 μm being obtained. Granulation has the positive effect of aligning the average diameter of the fragrant and coated active principle with that of the detergent composition, and of reducing the surfaces in contact. This last point is also reflected in an improvement in the stability in the broad sense of the fragrance.

It therefore allows, as already pointed out, the release of the odor at the appropriate time.

Dishwasher formulations have undergone numerous modifications over the past ten years, which have led to the coexistence of various physical forms (gels, tablets, so-called standard granules and so-called "compact" or "micro" granules) and various compositions.

In particular, in order to reduce the aggressiveness towards consumers, the compositions have evolved towards less alkaline forms obtained by replacing the sodium metasilicate Na2Siθ3, granular, with sodium disilicate 2Siθ2, atomized Na2θ and compacted, or with hydrated carbonate / silicate cogranules sold by RHONE-POULENC under the trade name of Nabion 15®.

Formulas based on chlorinated products, therefore containing isochlorocyanurates which generate hypochlorites in solution, have lost market share to chlorine-free formulations containing perborate-activator pluriacetylated systems which are similar to the systems used for washing clothes.

Consequence induced, the absence of chlorinated salts as mentioned above has also enabled the formulator to introduce specific enzymatic systems into the compositions for dishwashers, in particular proteases and amylases, well suited to the types of soiling to be removed in a washing machine. -dishes.

Finally, as in the field of laundry detergents, phosphate-free versions also exist in which tripolyphosphate has been replaced by complex systems based on carbonate, citrate, polyacrylates and other organic sequestrants.

These developments have brought certain advantages, but also certain disadvantages, in particular in the washing performance and the abandonment of Active chlorine systems for certain formulations contributes to the appearance of negative odors, probably by a deodorant effect may be less marked in the case of perborate systems.

In this context, it recently appeared on the European market of products to be introduced in the dishwasher, in the cutlery baskets, and which slowly release a perfume, generally lemony intended to mask the negative odors. These products have a lifespan of the order of ten washes, but they therefore constitute the obligation of a complementary introduction, which complicates the task of the housewife who already has three different products to use for proper functioning of its appliance (detergent, rinse aid and regenerating salt, the softener).

The technique developed in the context of the present invention therefore adapts well to the evolution of formulations and offers the possibility of overcoming a certain lack of deodorization which has appeared more particularly with recent formulas.

Another property of the granules obtained from vanillin and derivatives can be taken advantage of by the coating with delay effect.

They have an anti-tarnishing effect on dishes and in particular metallic objects (stainless steel, silverware). Indeed, vanillin has an aldehyde function, therefore reducing or antioxidant.

This can be used to eliminate the redox potential of the washing baths at the end of the cycle, that is to say to neutralize the baths on the redox level. The excess of perborate or peracetic acid remaining at the end of the cycle has the drawback of persisting also in rinsing and drying and these oxidizing residues are attributed to the negative effects such as the blackening of the silverware.

Neutralizing the bath by releasing the vanillin at the end of the cycle makes it possible to avoid this drawback.

In accordance with the invention, a perfumed product is conditioned in such a way that the salting out of the perfume takes place only during washing in the dishwasher and in no way under the conditions of storage of the detergent formulation.

Thus, the perfume is chosen according to the envisaged application and it will be preferred to choose a perfume having no toxicity and more preferably approved in the food sector.

As a fragrant note, preferably that of vanilla is chosen, but it is also possible to envisage others: fruity notes such as by example, apple, peach, pear, passion fruit, pineapple, red fruit, lemon or a smell of caramel, almond or bergamot. There is no limitation to this list except that it should please the user.

For the definition of the chemical nature of the compounds corresponding to these odors, you can refer to the general literature data in particular "Encyclopedia of Chemical Technology. - read, pp 464 ^(3rd edition).

The names of chemical compounds corresponding to the aforementioned notes will be specified by way of illustration:

- apple: ethyl isoamyl acetate 2-methylbutyrate

- peach: γ-undecalactone

6-amyl-α-pyrone

- pear: decane- c / s-4- irans- ethyl 2-dienoate

- blueberry: isobutyl 2-buteneoate - blackcurrant: p-mentha-8-thiol-3-one

- cherry: benzaldehyde tolylaldehyde

- raspberry: 6-methyl-α-ionone p-hydroxyphenyl-2-butanone - caramel: 2,5-dimethyl-4-hydroxy-3 (2H) -furanone

- almond: 5-methylthiophen-2-carboxaldehyde

- bergamot: linalyl acetate

The scented product is most often an aldehyde, a ketone or an aliphatic, cycloaliphatic or aromatic ester. The invention relates more particularly to aromatic aldehydes.

In the following description of the present invention, the term “aromatic aldehyde” is understood to mean an aromatic ring of which one of the hydrogen atoms is replaced by a formyl group and by “aromatic”, the conventional concept of aromaticity as defined. in the literature, in particular by Jerry MARCH, Advanced Organic Chemistry, 4 ^th edition, John Wiley and Sons, 1992, pp. 40 and following.

As mentioned previously, vanillin and derivatives are entirely suitable for implementing the invention. The term “vanillin derivative” means a compound of substituted benzaldehyde type (generally with 1 to 3 other substituents), that is to say more precisely a benzene ring comprising at least one formyl group and at least one group chosen from the hydroxyl group and the alkoxy groups having from 1 to 4 carbon atoms, preferably a methoxy or ethoxy group. The invention does not exclude the presence of other substituents on the aromatic ring, in particular alkyl radicals having from 1 to 4 carbon atoms or alkenyl radicals having from 2 to 5 carbon atoms.

As examples, mention may be made of vanillin ((3-methoxy-4-hydroxy-benzaldehyde), ethyl vanillin (3-ethoxy-4-hydroxybenzaldehyde), isovanillin (4-methoxy-3-hydroxybenzaldehyde), o -vanillme (3-methoxy-2-hydroxy-benzaldehyde), syringic aldehyde (3,5-dιmethoxy-4-hydroxybenzaldehyde), veratric aldehyde (3,4-dimethoxybenzaldehyde), 3,4,5-trimethoxy - benzaldehyde. It is also possible to use vanillin derivatives, in particular vanillin bisulfite and also vanillin esters, preferably methyl or ethyl vanillate. For this purpose, reference may be made to compounds described in EP-A 0 697 458 which are incorporated by reference into the present application, so by vanillin derivative is also meant the esters of the above-mentioned compounds, that is to say the formyl group is replaced by a group COOR- _j ; R- _j preferably representing an alkyl radical, linear or branched, having from 1 to 12 carbon atoms, preferably from 1 to 6; a cycloalkyl radical preferably having 6 carbon atoms, an aralkyl radical having from 6 to 12 carbon atoms, preferably 7 or 8 carbon atoms.

The invention does not exclude the implementation ^of a perfumed product obtained from a liquid fragrance (e.g., a gasoline or more species) and deposited on suitable support, in particular silica or a clay, for example sepiolite. As examples of this type of perfume, one can consider the essences of menthol or anise.

The invention relates more particularly to the use of synthetic vanillin (Rhovanyl from RHONE-POULENC) and analogous products such as ethylvanillin (Rhodiarome from Rhône Poulenc), mixtures of vanillin and ethylvanillin, vanillate from methyl, vanillin bisulfite. The granulométπe (mean diameter) of the flavored product to be coated is advantageously between 200 and 700 .mu.m, preferably between 400 and 500. Such granulométπe has the advantage to ^be similar to that of detergent formulations for dishwasher, and avoids too many and too intimate contacts with the aggressive components of the formulation which could cause detrimental chemical interactions, with modification of odor or color.

With regard more particularly to vanillin and its derivatives, it is possible to use the products described in PCT application FR 95/02957 which have a platelet appearance with a particle size advantageously between 400 and 700 μm and those described in EP-A 0 689 772 which are in the form of pearls having an average diameter (dso) varying from 500 μm to 2000 μm, but the in this application, pearls with an average diameter of between 500 μm and 700 μm are preferred. The mean diameter is defined as being such that 50% by weight of the particles have a diameter greater or less than the mean diameter.

As types of coating which may be used, the following compounds and their mixtures can be mentioned, which can be classified into two categories:

- those which release the perfume by melting such as fatty acids, fatty alcohols, polyoxyethylenated fatty alcohols solid at room temperature, polyethylene glycol of molecular mass greater than 1000, fatty substances, solid paraffins, - those which release the perfume by dissolving and / or dispersing such as gelatin, polysaccharides, chitin and chitosan.

As regards the first category of coating agents which can be melted under washing conditions, these are products having a melting point of at least 30 ° C., preferably varying between 30 ° C. and 70 ° C., and even more preferably, between 40 ° C and 60 ° C.

The coating agents do not have a frank melting temperature, but a melting zone. Thus, the temperature mentioned corresponds to the temperature at the start of the melting.

The fatty acids used are generally long chain saturated fatty acids, that is to say having a chain length between approximately 9 and 21 carbon atoms such as, for example, capric acid, lauric acid , tridecylic acid, myristic acid, palmitic acid, stearic acid. It is possible that said acids are in salified form, preferably in sodium form. Generally, the acid is partially salified (most often less than 10%). It should be noted that there may be mixtures of fatty acids among which there are unsaturated acids, for example oleic acid but in a minor amount.

As regards the fatty alcohols used, they have a chain of carbon atoms between approximately 16 and 22 carbon atoms such as, for example, myristyl alcohol, palmityl alcohol, stearyl alcohol.

It is also possible to use polyoxyethylenated fatty alcohols resulting from condensation with ethylene oxide at the rate of 6 to 20 moles of ethylene oxide per mole, of linear or branched fatty alcohols having from 10 to 20 carbon atoms such as, for example, coconut alcohol, tridecanol or myristyl alcohol.

As regards the use of fatty substances as coating agents, a wide range of products can be used, of animal origin, of vegetable origin (for example, coconut oil, soybean oil, flax, palm, sunflower, cotton seeds) or synthetic and which can also be subject to special treatment (hydrogenation, acetylation etc.).

We can quote more specifically:

- esters of glycerol and long chain fatty acids such as glycerol monosterate (Myvaplex 600; Eastman Kodak Company), glycerol monopalmitostearate (Géléol - Gattefosse Company), glycerol palmitosterate (Biogapress WL 3326AT - Gattefosse Company ), ethylene glycol palmitosterate (Monthyle - Gattefosse Company), polyglycerol palmitostearate (Plurol WL1009 - Gattefosse Company), polyglycol 1500 and 6000 palmitostearate (Stearate 1500 and 6000 WL 1644 - Gattefosse Company), glycerol monolinoleate ( Myverol 18-92; Eastman Kodak Company).

- optionally mono- or diacetylated glycerol esters of long chain fatty acids such as monoacetylated or diacetylated monoglycerides and their mixture (Myvacet 5-07 - 7-07 - Eastman Kodak Company);

- hemisynthetic glycerides (Suppocire A and Suppocire D - Gattefosse Company);

- sucroglycerides derived from fatty oils such as coconut oil (Celynol LMO - Rhône-Poulenc SA), palm oil (Celynol MSPO 11 - Rhône- Poulenc SA), hydrogenated palm oil (Celynol MPSO 11 H - Rhône-Poulenc SA), and hydrogenated soybean oil;

- fatty acid sucroesters such as sucrose monopalmitate (Sucroester 15 - Gattefosse Company), sucrose monodistearate (Sucroester 11 - Gattefosse Company) and sucrose distearate (Sucroester 7 - Gattefosse Company).

It is also possible to use mixtures of coating agents such as, for example, glycerol esters of fatty acids and sucroesters of fatty acids or fatty alcohols also in admixture with said sucroesters; the sucroesters generally representing in this case less than 10% of the weight of the mixture.

Among the coating agents capable of dissolving and / or dispersing under the washing conditions, gelatin is advantageously used (preferably having a jelly strength measured using a 100, 175 and 250 Bloom gelometer). It can come either from the acid treatment of pigskin and ossein, or from the alkaline treatment of bovine and ossein skins.

As more specific examples of polysaccharides, mention may be made, among others, of the following products and their mixtures:

- starches derived in particular from wheat, corn, barley, rice, cassava or potato, native, pregelatinized or modified and more particularly native corn starches rich in amylose (Hylon VII at 70% amylose), pregelatinized corn starches (Ultratex 1 to 25% amylose), modified corn starches (Ultraset LT at 10% amylose), modified waxy corn starches (Colflo 67), corn starches waxy pregelatinized (Instant Clearjel), waxy corn starches modified in particular starch OSSA / octenylsuccinate sodium (Purity Gum 1773);

- cellulose esters or ethers, in particular cellulose acetate phthalate (Aquateric CD910 - FMC Corp.), carboxymethylcellulose in sodium form

(Blanose 7LF - Aqualon); modified celluloses such as aqueous dispersions of ethylcellulose (Aquacoat - FMC Corp.), and of hydroxypropylcellulose (Klucel EF - Aqualon Company);

- gums such as carrageenan gum, Kappa (Aubytel X52) or Iota carrageenan, pectin (Unipectin HMI), guar gum, locust bean gum, and xanthan gum (XB 23 from RHONE-POULENC or CX91 from Sanofi), alginates.

In the non-limiting list of the aforementioned coating agents, the following coating agents or their mixtures are advantageously chosen: fatty substances, preferably, esters of glycerol and optionally acetylated fatty acids, optionally salified fatty acids.

The level of coating agent relative to the solid perfumed product, preferably the vanillin can be between 5 and 95%, preferably between 5 and 40% and even more preferably between 10 and 30% by weight. It is also possible to add other additives to the coating agent, in particular a dye (generally less than 1%) if it is desired to obtain colored granules and dyes can be mentioned such as by example, tartrazine, indigo carmine, erythrosine ...

The deposition of the coating agent is carried out from the molten product or from an emulsion or dispersion, preferably aqueous, of the coating agent. The concentration of the coating agent is determined according to its solubility for the coating agents of the second category. It is most often between 0.5 and 50%, preferably between 20 and 30%. For the application of the coating agent to the perfumed product, any method commonly used to encapsulate a solid product can be used.

As examples of techniques used, mention may be made of coating in a rapid mixer or in a fluidized bed, coacervation, spray coating of the molten product or else of the product in emulsion or in dispersion, coating on a tray and equivalent methods.

The preferred coating method is the fluidized bed technique.

According to this technique, the scented product, usually in powder form, is placed in a fluidized bed apparatus, and preferably, equipped at the top or at the bottom with spray nozzles. The emulsion and / or dispersion containing the coating agent is pumped and atomized in the apparatus on the bed of fluidized particles, generally by a stream of hot air. In practice, the solvent used to form the emulsion and / or dispersion is water although other solvents such as alcohols and glycols can be used.

The application of the emulsion and / or dispersion of the coating agent on the powder generally lasts between 15 minutes and 4 hours, depending on the thickness of the coating desired and the concentration of the solution and / or dispersion.

The granules of coated perfumed product are dried if necessary, generally between 1 minute and 1 hour. A product is obtained in granular form comprising at its heart, the perfumed product and at the periphery, the coating agent.

The granules of the invention can be introduced into any detergent composition for a dishwasher, whatever its physical form, namely in the form of powders, granules, tablets, pearls, pellets, etc.

They are therefore added to the detergent compositions in an amount such that they represent approximately from 1 to 10%, preferably from 1 to 5% by weight of the detergent composition.

The detergent compositions also comprise at least one surfactant in an amount which can range from 0.5 to 10%, preferably of the order of 1 to 5%, of the weight of said detergent composition expressed as dry matter.

Among these, there may be mentioned: - anionic surfactants of the alkali metal soap type (alkaline salts of C8-C24 fatty acids), alkali sulfonates (C8-C13 alkylbenzene sulfonates, C12-C16 alkylsulfonates) , oxyethylenated and sulfated C6-C16 fatty alcohols, oxyethylenated and sulfated C8-C13 alkylphenols, alkali sulfosuccinates (C12-C16 alkyl sulfosuccinates) - - non-ionic surfactants of the polyoxyethylenated C _β -Ci2 alkylphenol type, polyoxyethylenated and / or polyoxypropylene aliphatic C8-C22 alcohols, block copolymers of ethylene oxide - propylene oxide, optionally polyoxyethylenated carboxylic amides ... In addition to said complexes and surfactants, there may be present, in detergent compositions for washing dishes, the usual additives used in the composition of detergent formulations for washing in a dishwasher.

Mention may in particular be made of "builders" (agents improving the surface properties of surfactants) and more particularly:

- organic phosphonates of the type from those of the DEQUEST® range from MONSANTO at a rate of at least 0.5% of the total weight of detergent composition expressed as dry matter,

- phosphates at a rate of at least 25% of the total weight of detergent composition expressed as dry matter,

- nitriloacetic acid, N, N-dicarboxymethyl-2-aminopentanedioic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, up to approximately 10% of the total weight of detergent composition expressed as dry matter, - acid citric, gluconic acid or tartaric acid or their salts up to approximately 50% of the total weight of detergent composition expressed as dry matter, In the detergent compositions, there are also:

- bleaching agents, per-compounds such as perborates, percarbonates associated or not with N, N, N ', N'-tetraacetylethylenediamine (TAED) or chlorinated products of the chloroisocyanurate type up to approximately 30% of the total weight of said detergent composition expressed as dry matter,

- anti-encrustation, anti-fog or anti-stain agents of the acrylic acid and maleic anhydride copolymer type or acrylic acid homopolymers in an amount which can range up to approximately 10%, - alkali metal silicates Siθ2 / Na2θ molar ratio of the order of 1 to 3.3, as anti-corrosion agents for metals, in an amount which can range up to approximately 15% of the total weight of said detergent composition expressed as dry matter,

- alkaline agents such as carbonates, bicarbonates, sesquicarbonates of alkali metals, cogranules of alkali metal carbonate and alkali metal silicate of molar ratio Siθ2 Na2θ of the order of 1.5 to 3.5, with a weight ratio carbonate / silicate of the order of 5/95 to 45/55, containing water according to a water / silicate weight ratio expressed as dry of at least 33/100, in an amount up to 60% of the total weight of said composition expressed as dry matter,

fillers of the sodium sulfate type for powdered detergents in an amount which can range up to 50% of the total weight of said composition expressed as dry matter,

- other various additives such as enzymes in an amount up to 5% of the total weight of said composition expressed as dry matter, dyes, anti-tarnishing agents, agents for suspending dirt, etc.

Examples of detergent compositions for dishwashers in which the granules of the invention may be used are given below. The compositions are given for illustrative purposes only.

- Formulations with phosphate

- sodium tripolyphosphate 20 - 50%

- sodium disilicate 5 - 35% - sodium carbonate 0 - 40%

- sodium metasilicate 0 - 50%

- sodium perborate or percarbonate 5 - 20%

- activator (TAED) 1 - 6%

- enzymes (proteases, amylases, lipases) 0 - 4% - nonionic surfactants 0.5 - 2%

It should be noted that the disiiicate and the sodium carbonate can be introduced in the form of a cogranulate, for example Nabion 15®. Examples of phosphate-free formulations are given below.

- Phosphate-free formulas The phosphate part is replaced by the following, the rest of the formulation being identical to the previous case:

- sodium citrate 5 - 35%

- sodium polyacrylate 1 - 8%

- organic sequestrants 0.1 - 5% - sodium sulfate 0 - 20%

Finally, another object of the invention consists in the use, as perfuming agents during the washing of the dishes in detergent compositions in particular for washing in the dishwasher, of at least granules comprising a central core formed essentially perfumed product in powder form surrounded by a peripheral layer formed essentially of a solid coating agent at room temperature and capable of being modified under the conditions of use in a dishwasher, so to release the perfume under the effect of the rise in temperature, during the washing cycle.

Examples of perfumed solids and coating agents as well as more specific examples of these which can occur in the granules according to the invention have already been mentioned above. The same applies to the other additives which may be present alongside the said granules.

As mentioned above, the granules of the invention are perfectly well suited for use in detergent compositions intended for the dishwasher of the housewife. They are also suitable in other fields of use such as detergency for communities and industrial detergency, in particular in the food industries (bottle washing) and others.

The following examples are given by way of illustration.

Examples;

Example 1

Vanillin granules coated with an αlvceride.

1 - Preparation of an emulsion based on glycerol sterate monopalmitate (Géléol®).

In a 1 liter glass container, we load:

- 62 g of gelol

- 3 g of sucrose distearate (sucroester 7) - 1 g of a 1% aqueous solution of tartrazine - 800 g of demineralized water.

The gelol and the sucroester are melted with magnetic stirring and then emulsified with demineralized water heated to 95 ° C. with polytron at the speed of 12,000 rpm for one minute.

2 - Vanillin treatment: In a fluidized bed apparatus of the GLATT GPC G1 type equipped with a Wurster, 300 g of vanillin powder (Rhovanyl) are loaded. The particle size of this powder is between 50 and 200 μm.

The preceding suspension, still kept stirred, is then pumped and sprayed into the GLATT GPC G1 device on the bed of fluidized particles by a stream of air.

The following coating conditions are applied:

- fluidization air flow: 73 m - ^ / h

- powder temperature: 32 ° C - spraying air pressure: 2 bar

- spraying air temperature: 45 ° C

- emulsion temperature: 70 ° C

- flow rate of the coating emulsion: 8.4 g / min - duration of the spraying: 103 min

- drying: 14 min

- powder temperature during drying: 32 ° C Total amount of sprayed emulsion: 866 g

330 g of coated vanillin are recovered with a level of coating agent of 17% relative to the final product.

Example 2

Example 1 is reproduced using ethylvanillin in place of vanillin.

Example 3

Vanillin granules coated with gelatin with carrageenan additive.

1 - Preparation of a gelatin-based coating agent solution:

In a 1 liter glass container, we load: - 100.5 g of 250 Bloom gelatin

- 800 g of demineralized water

The gelatin is dispersed cold with magnetic stirring and then dissolved at 55 ° C with magnetic stirring.

At the same time, 2.35 g of carrageenan ub are dissolved in 400 g of demineralized water at 90 ° C; this solution is added to the previous one and kept at 70 ° C with magnetic stirring for 45 minutes.

2 - Treatment of vanillin:

400 g of vanillin powder are loaded into a GLATT GPC G1 fluidized bed apparatus equipped with a Wurster. The particle size of this powder is between 50 and 200 μ.

The preceding suspension, still kept stirred, is then pumped and sprayed into the GLATT GMC G1 apparatus on the bed of particles fluidized by a stream of air.

The following filming conditions are applied: - fluidization air flow: 73 - 90 m3 / h

- spraying air pressure: 2 bar

- spraying air temperature: 58 ° C

- emulsion temperature: 70 ° C - flow rate of the coating emulsion: 8.8 g / min

- duration of spraying: 148 min

- drying: 10 min

Total amount of sprayed emulsion: 1303 g 475 g of coated vanillin are recovered with a coating agent content of

20% compared to the final product.

Example 4

Vanillin granules coated with sodium stearate. 1 - Preparation of an emulsion based on stearic acid and sodium hydroxide: In a 1 liter glass container:

0.33533 mol of stearic acid is loaded and heated to 90 ° C. with magnetic stirring. Once melted, an aqueous solution containing 0.0088 mol of sodium hydroxide in 500 g of distilled water heated to 85 ° C is added; the soda content is such that the molar ratio is 2.5% between soda and stearic acid.

This charge is maintained at 87 ° C. with magnetic stirring for 2 hours 30 minutes; it is then hot emulsified with polytron (turbine speed: 14,300 rpm). 2 - Treatment of vanillin:

400 g of vanillin powder are loaded into a GLATT GPC G1 fluidized bed apparatus equipped with a Wurster. The particle size of this powder is between 50 and 200 μm.

The preceding suspension, still kept stirred, is then pumped and sprayed into the GLATT GMC G1 apparatus on the bed of particles fluidized by a stream of air.

The following coating conditions are applied:

- fluidization air flow: 73 m3 / h

- powder temperature: 36 - 39 ° C - spray air pressure: 2 bar

- spraying air temperature: 70-75 ° C

- emulsion temperature: 70-80 ° C

- flow rate of the coating emulsion: 9 g / min

- duration of spraying: 67 min - drying: 1 1 min

- powder temperature during drying: 38 ° C Total amount of sprayed emulsion: 600 g 462 g of coated vanillin are recovered with a coating agent content of 20% relative to the final product.

Example 5 Vanillin granules coated with 1-octadecanol.

1 - Preparation of an octadecanol emulsion in water:

In a 1 liter glass jacketed reactor,

- 0.353 mole of 1-octadecanol

- And 1.6 g of sucrose distearate (sucroester 7) which is melted in 450 g of distilled water heated to 88 ° C.

Once melted, it is emulsified with polytron at 5000 rpm for 20 minutes, then 300 g of distilled water are added while stirring is maintained at 1500 rpm.

2 - Treatment of vanillin.

400 g of vanillin powder are loaded into a GLATT GPC G1 fluidized bed apparatus equipped with a Wurster. The particle size of this powder is between 50 and 200 μm.

The preceding emulsion, still kept stirred, is then pumped and sprayed into the GLATT GPC G1 apparatus on the bed of particles fluidized by a stream of air. The following coating conditions are applied:

- fluidization air flow: 73 m ³ / h

- powder temperature: 33 ° C

- spraying air pressure: 1.5 bar

- spraying air temperature: 79 ° C - emulsion temperature: 88 ° C

- flow rate of the coating emulsion: 11 g / min

- duration of spraying: 76 min

- drying: 11 min

- powder temperature during drying: 36 ° C Total amount of sprayed emulsion: 852 g

481 g of vanillin coated with a coating rate of 20% relative to the final product are recovered. Examples 6 to 1Q

In these examples, the granules obtained according to examples 1 to 5 are tested.

The evaluation test is a practical test consisting in carrying out a real wash in a household dishwasher, for example of Miele or Bosch brand, with 30 g of formulation containing a percentage of encapsulated vanillin, and to note the perception or non perception odor during the cycle, depending on the temperature change, then at the end of the cycle, when the dishwasher opens, finally on the dishes after cooling. Good results of perception during washing and when opening the dishwasher are obtained with the granules of the previous examples and more particularly with vanillin and ethylvanillin coated with 17% glycerol palmitostearate.

On the other hand there is no longer any perceptible odor on the dishes after cooling.

These results are obtained with both phosphate and non-phosphate formulations such as:

- Nabion 15® 42%

- Rhodiaphos LV® (sodium tripolyphosphate) 40% - Perborate monohydrate 10%

- TAED Granular 3%

- Plurafac LF403® (non-ionic surfactant) 2% - Vanillin 17% Géléol® 3% or - Nabion 15® 44%

- Sodium citrate 30%

- Polycrylate 4500 5%

- Enzymes 3%

- Plurafac LF403® 1% - Sodium perborate 10%

- 4% granular TAED

- Vanillin 20% Gelatin 3%

Application test In order to demonstrate the anti-seeding effect obtained with the granules of the invention, a test was carried out by 24 users who used a detergent composition for dishwashers comprising:

- sodium tripolyphosphate (Rhodiaphos LV®) = 46% - sodium disilicate (Britesil®) 35%

- sodium perborate monohydrate 12%

- TAED 2%

- enzymes. NOVO Espérase® 1%. Amylase® = 1%

- non-ionic surfactant (Plurafac LF 403) 1%

- vanillin granules of Example 1 2%

Each user received 200 g of detergent composition and carried out 12 washes. He answered a questionnaire on the appearance of the dishes. Notice was required in relation to the commercial product he usually uses). The washing was carried out by the user, in the usual manner. Out of 24 users, 18 judged their dishes to be brighter than usual. 11 users said it was the cutlery that was shinier.

Good cleaning performance has been recognized since 14 users judged the detergent composition tested to be superior to that of their usual detergent.

Claims

1 - Granules of a perfumed product with controlled release characterized in that they comprise a central core formed essentially of the perfumed product in pulverulent form surrounded by a peripheral layer formed essentially of a solid coating agent at room temperature and likely to change in the conditions of use in the dishwasher, in order to release the perfume under the effect of the rise in temperature, during the washing cycle. 2 - Granules according to claim 1 characterized in that the chosen fragrance note is vanilla or fruity notes such as apple, peach, passion fruit, pineapple, red fruit, lemon or a smell of caramel, d almond, bergamot, mint or anise. 3 - Granules according to one of claims 1 and 2 characterized in that the scented product is an aromatic aldehyde, preferably vanillin, analogous products and derivatives, vanillin bisulfite or its esters, and more preferably vanillin and / or ethylvanillin. 4 - Granules according to one of claims 1 to 3 characterized in that the scented product is vanillin and / or ethylvanillin used in pulverulent, platelet or pearl form. 5 - Granules according to one of claims 1 and 2 characterized in that the scented product is obtained from a liquid perfume (one or more essences) and deposited on a suitable support, in particular a silica or a clay. 6 - Granules according to one of claims 1 to 5 characterized in that the particle size (average diameter) of the scented product to be coated is between 200 and 700 microns, preferably between 400 and 500. 7 - Granules according to one of claims 1 to 6 characterized in that the coating agent has a melting point of at least 30 ° C, preferably varying between 30 ° C and 70 ° C, and even more preferably, between 40 ° C and 60 ° C. 8 - Granules according to one of Claims 1 to 7, characterized in that the coating agent is chosen from the following compounds and their mixtures: fatty acids, fatty alcohols, solid ethoxylated alcohols at ambient temperature, polyethylene glycol with a molecular mass greater than 1000, solid paraffins, gelatin, polysaccharides, chitin, chitosan and fatty substances. 9 - Granules according to claim 8 characterized in that the coating agent is chosen from the following compounds and their mixtures: - long chain saturated fatty acids having a chain length, preferably between about 9 and 21 carbon atoms such as capric acid, lauric acid, tridecylic acid, myristic acid, acid palmitic, stearic acid; - fatty alcohols having between about 16 and 22 carbon atoms such as myristyl alcohol, palmityl alcohol, stearyl alcohol; - polyoxyethylenated fatty alcohols resulting from condensation with ethylene oxide at the rate of 6 to 20 moles of ethylene oxide per mole of linear or branched fatty alcohols having from 10 to 20 carbon atoms such as copra alcohol, tridecanol or myristyl alcohol; - esters of glycerol and long chain fatty acids such as glycerol monostearate, glycerol palmitostearate, ethylene glycol, polyglycerol, polyglycol, glycerol monolinoleate; - optionally mono- or diacetylated glycerol esters of long chain fatty acids such as monoacetylated or diacetylated monoglycerides and their mixture; - hemisynthetic glycerides; - the sucroglycerides derived from fatty oils such as coconut oil or palm oil possibly hydrogenated; - fatty acid sucroesters such as sucrose monopalmitate, sucrose monodistearate and sucrose distearate; the gelatin preferably having a jelly strength of 100, 175 and 250 Bloom; - starches derived in particular from wheat, corn, barley, rice, cassava or potato, native, pregelatinized or modified in particular by OSSA; - cellulose esters or ethers, in particular cellulose phthalate acetate, carboxymethylcellulose in sodium form; modified celluloses such as aqueous dispersions of ethylcellulose and hydroxypropylcellulose; - gums such as carrageenan gum, Kappa or Iota, pectin, guar gum, locust bean gum, and xanthan gum, alginates. 10 - Granules according to one of claims 7 to 9 characterized in that the coating agent is chosen from the following compounds and their mixtures: fatty substances, preferably, esters of fatty acids optionally acetylated, possibly salified fatty acids. 11 - Granules according to one of claims 1 to 10 characterized in that the level of coating agent relative to the solid perfumed product, is between 5 and 95%, preferably between 5 and 40% and again more preferably between 10 and 30% by weight. 12 - Process for the preparation of the granules of a perfumed product with controlled release, characterized in that the deposition of the coating agent is carried out from the molten product or from an emulsion or dispersion, preferably aqueous of the coating agent. 13 - A method according to claim 12 characterized in that the coating is carried out in a rapid mixer or in a fluidized bed or by coacervation, spray coating of a molten product or a product in emulsion and / or dispersion , by coating on a tray. 14 - Method according to one of claims 12 and 13 characterized in that the coating is conducted according to the technique in a fluidized bed. 15 - Method according to one of claims 12 to 14 characterized in that the particle size (average diameter) of the scented product to be coated is between 200 and 700 μm, preferably between 400 and 500. 16 - Detergent compositions for washing in a dishwasher, characterized in that they comprise granules of a perfumed product with controlled release comprising a central core formed essentially of the perfumed product in pulverulent form surrounded by a peripheral layer formed essentially of a coating agent which is solid at room temperature and which can change under the conditions of use in a dishwasher, in order to release the perfume under the effect of the rise in temperature, during the washing cycle. 17 - Compositions according to claim 16 characterized in that they comprise the granules described in one of claims 1 to 11. 18 - Compositions according to claim 16 characterized in that they comprise granules based on vanillin and or ethyl vanillin described in one of claims 1 to 11. 19 - Compositions according to one of claims 16 to 18 characterized in that they comprise at least granules of perfumed product with controlled release in an amount which can range from 1 to 10%, preferably of the order of 1 to 5 %, of the weight of said detergent composition expressed as dry matter. 20 - Use, as perfuming agents, during washing in the dishwasher in detergent compositions of at least granules of a perfumed product with controlled release comprising a central core formed essentially of the perfumed product in pulverulent form surrounded by a peripheral layer formed essentially of a coating agent which is solid at room temperature and which can change under the conditions of use in a dishwasher, in order to release the perfume under the effect of the rise in temperature, during of the wash cycle 21 - Use, as perfuming agents during washing in the dishwasher in detergent compositions of at least the granules described in one of claims 1 to 11. 22 - Use according to one of claims 20 and 21 characterized in that the detergent compositions comprise at least granules of perfumed product with controlled release in an amount ranging from 1 to 10%, preferably of the order of 1 to 5 %, of the weight of said detergent composition expressed as dry matter. 23 - Use according to one of claims 20 to 22 characterized in that the detergent compositions comprise at least one surfactant in an amount which can range from 0.5 to 10%, preferably of the order of 1 to 5% , the weight of said detergent composition expressed as dry matter. 24 - Use, as anti-tarnishing agents, during washing in the dishwasher in detergent compositions of at least the granules described in one of claims 1 to 11.