WO1998046717A1 - Use of a coated antioxidant system in detergency and resulting compositions - Google Patents

Abstract

The invention concerns the use of a coated antioxidant system, in detergency, to minimise colour fading and the resulting compositions. It is applicable to industrial as well as domestic clothes washing. It consists in the use of a coated antioxidant system to protect colours of textile fabrics during washing, in a detergent composition with or without an oxidant system and/or in a composition for post-washing operations.

Description

 USE OF AN ANTI-OXIDIZING SYSTEM ENROBF FN DFTERGENCE

AND COMPOSITIONS OBTAINED.

The present invention relates to the use, in detergency, of a coated antioxidant system making it possible to minimize the process of color alteration. It also targets compositions involving it.

The invention relates both to washing linen, for industrial use and for household use.

The repeated washing of the linen poses, at the present time, the problem of the alteration of the colors commonly called "fading" of which there are several causes.

The removal of oxidizable dirt such as, for example, tea, fruit juice, colored vegetables, textiles poses a real problem for the skilled person. Traditionally, the elimination is done by the implementation of a bleaching system comprising a hydrogen peroxide and / or organic peroxyacids. When the colored articles are washed with such formulas called "HDP" (heavy duty powder) and at temperatures above 40 ° C, there is discoloration due to the bleaching system. Textile articles, in particular cotton, and in particular cotton dyed by the so-called "direct" dyeing process, undergo a color change with the washings which accumulate during their lifetime.

The intensity of the colors can also be reduced by the deposit of lime on the textiles, veiling the surface with an opaque white film. In addition, white cottons are also subject to chemical degradation or depolymerization due to the combined actions of the oxidizing system, the temperature, the alkalinity of the medium and the metal cations present as impurities in the water. used for washing.

Finally, it should be noted that colored textiles also undergo alteration due to the sun during the "wear" of the garment or during drying of textiles, outdoors. This phenomenon is strongly marked in areas with strong sunshine.

Generally, a conventional detergent composition, "any textile, any temperature" for washing laundry under domestic conditions, mainly comprises:

- a system of natural and / or synthetic surfactants,

- a builder / cobuilder system, also ensuring sufficient alkalinity,

- an oxidizing system, - a series of specific additives added in small proportions such as enzymes, brighteners, perfumes, polymers with targeted actions ...

These formulations make it possible to achieve satisfactory cleaning performance on all types of soiling, thanks to their high physicochemical activity, but they therefore also present risks of deterioration of fragile textile articles, in particular colored articles.

To limit the negative, too violent action of oxidizing systems, several types of solution have been proposed.

The first and simplest is obviously to completely exclude oxidizing systems, and also to reduce the alkalinity of the formulation. Most of the formulations claiming an adaptation to the washing of "colored" linen and fragile textiles are based on this principle and compensate for their lack of effectiveness by a reinforcement of surfactants (higher concentration, higher wetting activity ...), or other active ingredients (enzymes, sequestrants ...).

The second possibility is to avoid the production of excessively virulent oxidizing species during washing.

It is known to those skilled in the art that these are the traces of heavy metals or transition metals (Fe, Cu, Mn.Ti, Ni ...), coming from dirt or water from the networks, which, by catalytic effect, can promote the production of harmful oxidizing species capable of causing during washing, a chemical attack on cotton producing oxycellulose, itself soluble in an alkaline solution. This very negative phenomenon leads to depolymerization of cotton and to its mechanical embrittlement (tearing). It also of course leads to discoloration of colored items.

The use of specific sequestrants of transition metals, such as EDTA (ethylenediaminetetraacetate), DTPA (diaminotriethylenepentaacetate), amino phosphonates (Dequest® from Monsanto), is known to reduce the risks of the formation of harmful species and therefore allows protection of textile articles during washing.

It is believed that the complexing action of these sequestrants reduces or cancels the catalytic activity of the metals present in ionic form in the washing bath. Organic complexing agents are known to limit the chemical attack on cotton which leads to its depolymerization, but they are not known to be capable of protecting the colors of cotton fabrics from attack by bleaching systems. The third route is that of bleach activators, especially TAED (tetraacetylethylenediamine), which, associated with persalts releasing hydrogen peroxide, most often lead to the production of peracetic acid. Depending on the relative proportions between the persalt generating the hydrogen peroxide and the activator (for example, TAED), one finds in the washing bath both hydrogen peroxide and peracetic acid, or else only peracetic acid, at least after the time necessary for the TAED perhydrolysis reaction. This now widely used technology has two advantages:

- washing temperatures can be reduced because peracetic acid acts at a lower temperature than traditional hydrogen peroxide, the risks of alteration of textiles and colors are thus partly reduced, - the formation of intermediate peracetic acid is a preponderant reaction which decreases the possibilities of forming other harmful oxidizing species because peracetic acid is less sensitive to the catalytic effects of metals than hydrogen peroxide. More recently, it has been proposed to introduce into detergent compositions, metallic organic complexes, in particular of manganese, under precise conditions of addition, so as to obtain an activation of hydrogen peroxide by a "controlled" catalysis of its decomposition, to achieve bleaching effects at low temperatures.

Unfortunately, the conditions of use of detergents by the general public, very variable and necessarily uncontrolled have led to "incidents" of washing such as violent discoloration and chemical degradation due to the overactivity of these organometallic catalysts, which allow the production of chemical species that are too aggressive for cotton colors and fibers.

Finally, there has been described in EP-A-0 710 714, the addition, in whitening compositions, of mineral products such as lamellar alkali silicates or clays which make it possible to reduce the fading of colors.

It is therefore desirable to have a detergent formulation having good soil removal properties while protecting the colors. A first objective of the present invention is to protect the colors of textiles from a washing composition and more particularly with respect to a bleaching system. A second objective of the invention is to minimize the alteration of the colors of textiles in the face of sunlight.

It has now been found, and this is what constitutes the first object of the present invention, that the use of an antioxidant system coated in a detergent composition with or without an oxidizing system and / or in a composition intended for operations protect the colors of textiles during washing.

By post-washing composition, the invention relates more particularly to rinsing and / or softening compositions and / or the compositions used, for example, during a mechanical drying operation.

In the present invention, the term “coated antioxidant system” means a system comprising at least one antioxidant agent and a coating product, the coating agent superficially coating the antioxidant agent. By "antioxidant" is meant a free radical scavenger, capable of inhibiting the self-oxidation processes by free radicals.

According to the invention, the coating agent is a solid compound at ambient temperature capable of changing under the conditions of the application of the medium in which it is used, in order to release the antioxidant agent during this application . The coating technique is in no way limiting and the concept of coating is understood to mean all the conventional coating techniques including, among other things, spray coating and / or polymerization encapsulation of two monomers. at the interface of an emulsion.

In the present text, "textiles" means all textile materials and in particular those based on natural, artificial, synthetic fibers and their mixture.

The invention relates more particularly to textiles based on natural fibers such as, in particular, cotton, wool, silk, linen, jute and hemp and those based on artificial fibers and more especially cellulose acetate, rayon or fibrane.

A first embodiment of the invention consists in using the antioxidant system coated in a detergent composition comprising or not comprising an oxidizing system.

According to a second embodiment of the invention, the coated antioxidant system is used in a rinsing and / or softening composition.

A third embodiment aims to introduce the coated antioxidant system, after washing, for example during the drying operation. A second object of the invention consists in a method of treating the surface of textile articles for the protection of their color, by deposition on said articles, during one or more washing, rinsing and / or operation operations. or softening or drying, of a coated antioxidant system. As antioxidant agents which are entirely suitable for the invention, mention may be made of phenolic compounds and / or their ethers.

The term “phenolic compound” means an aromatic compound, preferably a benzene ring comprising at least one hydroxyl group and optionally bearing substituents. The preferred phenolic compounds correspond more particularly to the following formula (I):

in said formula:

- n, number of substituents, is a number less than 4, preferably between 1 and 3,

- R represents one of the following atoms, groups or functions:

. a hydrogen atom,. a hydroxyl group,

. an alkyl radical, linear or branched, having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl,. a linear or branched alkenyl radical having from 2 to 6 carbon atoms, preferably from 2 to 4 carbon atoms, such as vinyl, allyl,. a linear or branched alkoxy radical having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms such as the methoxy, ethoxy, propoxy, isopropoxy, butoxy, radicals. an acyl group having from 2 to 6 carbon atoms,. a formyl group.

The antioxidant agents which are preferably used in the compositions of the invention are particularly vanillin and its derivatives.

The term “vanillin derivative” means a compound of substituted benzaldehyde type, 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 with 4 carbon atoms, preferably a methoxy or ethoxy group. As examples of antioxidants which may be used, there may be mentioned, inter alia, hydroquinone, pyrocatechin, methylhydroquinone, tert-butylhydroquinone, tert-butylcatechol, ditert-butylhydroquinone, 2,4- dimethyl-6-tert-butyphenol, salicylic aldehyde, butylhydroxyanisole, vanillin ((3-methoxy-4-hydroxybenzaldehyde), ethylvanillin (3-ethoxy-4-hydroxybenzaldehyde), isovanillin (4-methoxy- 3- hydroxybenzaldehyde), o-vanillin (3-methoxy-2-hydroxy-benzaldehyde), syringic aldehyde (3,5-dimethoxy-4-hydroxybenzaldehyde), veratric aldehyde (3,4-dimethoxybenzaldehyde), 3,4,5-trimethoxy-benzaldehyde The antioxidant agents are preferably chosen from: vanillin, orthovanillin, isovanillin, ethylvanillin, butylhydroxyanisole.

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.

The particle size (average diameter) of the product to be coated is advantageously between 200 and 700 μm, preferably between 400 and 500. Such a particle size has the advantage of being similar to that of detergent formulations for washing machines. 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 0 697 458 which are in the form of pearls having an average diameter (dsrj) varying from 500 μm to 2000 μm, but 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.

Among the coating agents which can be used, there may be mentioned in particular those which are fusible under the action of the rise in temperature and those which are capable of dissolving and / or dispersing under the action of the increase of temperature.

These are hydrophobic or low or slow solubility 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.

As types of coating agents which may be used, mention may in particular be made of the following compounds and their mixtures which can be classified into two categories: - those which release the antioxidant agent 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 antioxidant agent by dissolving and / or dispersing such as gelatin, polysaccharides, chitin and chitosan.

As regards the first category of coating agents, these are fusible under the 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 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. 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 about 16 and 22 carbon atoms such as, for example, myristyl alcohol, palmitic alcohol, stearyl alcohol.

It is also possible to use polyoxyethylenated fatty alcohols resulting from condensation with ethylene oxide in a proportion 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, cottonseed) 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);

- the 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).

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 gelometer of 100 , 175 and 250 Bloom). 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 the native starches of corn rich in amyiosis (Hylon VII at 70% amylose), the pregelatinized corn starches (Ultratex 1 to 25% amylose), the modified corn starches (Ultraset LT at 10 % amylose), modified waxy corn starches (Colflo 67), pregelatinized waxy corn starches

(Instant Clearjel), waxy corn starches, especially starch

OSSA / sodium octenylsuccinate (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 product, preferably the vanillin can be between 5 and 50%, 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 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 antioxidant, 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 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 obtained are dried if necessary, generally between 1 minute and 1 hour. A product is obtained in granular form comprising at its core, the antioxidant agent and at the periphery, the coating agent.

The coated antioxidant system is itself composed of: - from 50 to 95% by weight of an antioxidant agent,

- from 5 to 50% by weight of a coating product.

The preferred system includes:

- from 70 to 90% by weight of an antioxidant agent,

- from 10 to 30% by weight of a coating product. According to the first or second object of the invention, it is possible to protect the colors of textiles from degradation due to a bleaching system present in a detergent composition, by adding to said detergent composition, an agent coated antioxidant.

Thus, a third object of the invention is a bleaching composition intended for washing clothes while ensuring color protection, characterized in that it jointly comprises, an oxidizing bleach system and a coated antioxidant system.

The present invention lies in a new, different technique for protecting fibers, in particular cotton fibers. This technique consists in introducing into the detergent formulation, in addition to the oxidizing system, a coated antioxidant system, composed of a free radical scavenger or also called "antioxidant", capable of adsorbing on the textile fiber, and of a product which superficially coats the antioxidant, so as to delay its delivery into the washing bath. Unexpectedly, it is found that the use of the bleaching composition of the invention, during the washing of the linen:

- reduces the color change of colored articles after cumulative washes, although they are washed in the presence of an oxidizing system; this advantage of the system according to the invention is more particularly noticed when the washes are carried out in natural, mineral, limestone water and containing transition metals,

- reduces the depolymerization of the cotton itself,

- maintains high washing and bleaching performance.

The coexistence of an oxidizing system and an antioxidant system in the same formulation may appear a priori to be nonsense to those skilled in the art. In fact, the object of the invention is to optimize the behavior and the potential benefits of these two systems which appear to be antagonistic. The use of the composition of the invention makes it possible to achieve high washing performance, and in particular high "bleaching" performance, while reducing the negative effects of oxidizing systems, such as the chemical wear of cotton and the discoloration of colored items. It allows washing to be carried out at washing temperatures of the order of 40 ° C. to 60 ° C., temperatures which improve the performance of the oxidizing systems, while minimizing the negative effects mentioned above.

One of the characteristics of the bleaching composition of the invention is to comprise an oxygen-releasing bleaching system, comprising at least one per-compound, preferably a parsley.

A preferred form consists in combining a source of hydrogen peroxide and a peroxyacid precursor.

As examples of per-compounds capable of being used as bleaching agents, mention should in particular be made of perborates such as sodium perborate monohydrate or tetrahydrate; peroxygenated compounds such as sodium carbonate peroxyhydrate, pyrophosphate peroxyhydrate, urea peroxyhydrate, sodium peroxide, sodium persulfate.

The preferred bleaching agents are sodium perborate, mono- or tetrahydrate and / or sodium carbonate peroxyhydrate. Said compounds are generally associated with a bleach activator generating in situ in the washing medium, a peroxycarboxylic acid. Among these activators, mention may be made of tetraacetylethylenediamine, tetraacetylmethylenediamine, sodium tetraacetylglycoluryl, sodium p-acetoxybenzenesulfonate, pentaacetylglucose, octaacetyl lactose.

TAED is the bleach activator used preferentially. The bleaching composition of the invention therefore comprises at least one bleaching agent in an amount from 65 to 90% by weight, preferably from 80 to 88%. It is optionally combined with a bleach activator present in an amount from 0 to 25% by weight, preferably from 10 to 15%.

It should be noted that the weight ratio between the bleaching agent and the activator is generally at least 1, and preferably greater than 2. Between other words, the quantity by weight of bleaching agent is greater than that of the whitening activator.

A characteristic of said coated antioxidant system is that it is capable of dissolving or dispersing in water and of adsorbing on fibers, in particular cotton. The bleaching composition advantageously comprises from 0.2 to 10%, preferably from 2 to 5% of coated antioxidant system, expressed as an antioxidant.

A preferred variant of the invention consists in using a coated antioxidant system comprising at least one antioxidant agent and at least one coating agent which is solid at room temperature and capable of being modified under washing conditions, in order to to release the antioxidant under the effect of the rise in temperature, during the washing cycle.

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

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 product. 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 delayed release of the antioxidant product consists in carrying out a slow dissolution of the coating in order to release the antioxidant agent, conditioned by the rise in temperature. The release of the antioxidant agent is "hot", that is to say at a temperature advantageously between 30 ° C and 70 ° C, preferably between 40 ° C and 60 ° C.

This delayed release of the antioxidant agent makes it possible to avoid its degradation by the oxidizing agent. The types of preferred coating agents have already been mentioned above. The bleaching compositions of the invention can be incorporated into conventional detergent compositions.

It is possible to prepare the bleaching compositions by simple mixing of powders and to introduce them during the preparation of the detergent, after the operations of atomization, drying and granulation of the other components of the detergent base.

A variant consists, in adding separately and in any order, the coated antioxidant system, the bleaching agent and possibly the activator at the same stage of manufacture of the detergent as mentioned above, that is to say at the end Manufacturing.

The preferred antioxidant is vanillin and / or derivatives. A fourth object of the invention consists of a detergent composition for a washing machine comprising said antioxidant system described above. comprising an antioxidant and a coating agent which is solid at room temperature and which can be modified under the washing conditions of the laundry, in order to release the coated product under the effect of the rise in temperature, during the wash cycle. In its preferred form, the detergent composition for washing machines is characterized by the fact that it comprises an antioxidant system coated in the form of granules comprising a central core formed essentially of vanillin and / or derivatives in solid form surrounded by a peripheral layer essentially formed by a coating agent which is solid at room temperature and which can change under the conditions of washing the laundry, in order to release the coated product under the effect of the rise in temperature, during the cycle of washing.

The nature of the coating agent, its characteristics and its rate have been described above. As mentioned previously, vanillin and / or ethylvanillin are preferably used in any solid, pulverulent, platelet or pearl form.

In addition to the coated antioxidant systems of the invention, the detergent composition containing them contains many components, in particular surfactants, builders and other additives as specified below: Surfactants.

The detergent composition can comprise surfactants in an amount corresponding to approximately 3 to 40% by weight relative to the detergent composition, surfactants such as anionic surfactants

. the alkyl esters sulfonates of formula R-CH (Sθ3M) -COOR ', where R represents an alkyl radical in C8-20- preferably in C-10 -Clδ "R' an alkyl radical in Cj-Cg, preferably in C1- C3 and M an alkali cation (sodium, potassium, lithium), substituted or unsubstituted ammonium (methyl-, dimethyl-

, trimethyl-, tetramethylammonium, dimethylpiperidinium ...) or derived from an alkanolamine (monoethanolamine, diethanolamine, triethanolamine ...). Mention may very particularly be made of methyl ester sulfonates whose radicals R is C14-C16; . alkyl sulphates of formula ROSO3M, where R represents a C5-C24, preferably C- | o ^_ - | 8 alkyl or hydroxyalkyl radical. M representing a hydrogen atom or a cation of the same definition as above, as well as their ethoxylenated (OE) and / or propoxylenated (OP) derivatives, having on average from 0.5 to 30 units, preferably from 0.5 to 10 OE and / or OP units; . sulfated alkylamides of formula RCONHROSO3M where R represents a C2-C22 alkyl radical. preferably in C6-C20. R 'a C2-C3 alkyl radical, M representing a hydrogen atom or a cation of the same definition as above, as well as their ethoxylenated (OE) and / or propoxylenated (OP) derivatives, having an average of 0, 5 to 60 OE and / or OP patterns; . the salts of C8-C24 saturated or unsaturated fatty acids, preferably C-J4-C20. C9-C20 alkylbenzenesulfonates. primary or secondary C8-C22 alkylsulfonates, alkylglycerol sulfonates, sulfonated polycarboxylic acids described in GB-A-1 082 179, paraffin sulfonates, N-acyl N-alkyltaurates, alkylphosphates, isethionates, alkylsuccinamates alkyl sulfosuccinates, monoesters or diesters of sulfosuccinates, N-acyl sarcosinates, sulfates of alkyl glycosides, polyethoxycarboxylates; the cation being an alkali metal (sodium, potassium, lithium), a substituted or unsubstituted ammonium residue (methyl-, dimethyl-, trimethyl-, tetramethylammonium, dimethylpiperidinium ...) or derived from an alkanolamine (monoethanolamine, diethanolamine, triethanolamine ...); Nonionic surfactants. polyoxyalkylenated (polyoxyethylenated, polyoxypropylenated, polyoxybutylenated) alkylphenols in which the alkyl substituent is Cβ-C- | 2 and containing from 5 to 25 oxyalkylene units; by way of example, mention may be made of the Triton X-45, X-114, X-100 or X-102 sold by Rohm & Haas Cy. ; . glucosamide, glucamide, glycerolamide; . polyoxyalkylenated C8-C22 aliphatic alcohols containing from 1 to 25 oxyalkylene units (oxyethylene, oxypropylene); by way of example, mention may be made of TERGITOL 15-S-9, TERGITOL 24-L-6 NMW sold by Union Carbide Corp., NEODOL 45-9, NEODOL 23-65, NEODOL 45-7, NEODOL 45-4 marketed by Shell Chemical Cy., KYRO EOB marketed by The Procter & Gamble Cy.

. the products resulting from the condensation of ethylene oxide the compound resulting from the condensation of propylene oxide with propylene glycol, such as the Pluronic sold by BASF;

. the products resulting from the condensation of ethylene oxide the compound resulting from the condensation of propylene oxide with ethylenediamine, such as TETRONIC sold by BASF;

. amine oxides such as alkyl oxides C10-C-18 dimethylamines, alkoxy oxides C8-C22 ethyl dihydroxy ethylamines; . the alkylpolyglycosides described in US-A-4,565,647; . amides of C8-C20 fatty acids; . ethoxylated fatty acids; . ethoxylated fatty amides; . ethoxylated amines.

Amphoteric and zwitterionic surfactants

. alkyldimethylbetaines, alkylamidopropyldimethylbetaines, alkyltrimethylsulfobetaines, Iles condensation products of fatty acids and protein hydrolysates. alkylamphoacetates or alkylamphodiacetates in which the alkyl group contains from 6 to 20 carbon atoms. Agent builders

The builders, adjuvants improving the properties of the surfactants, are used in amounts corresponding to approximately 5-50%, preferably to approximately 5-30% by weight for the liquid detergent formulas, or to approximately 10-80 %, preferably 15-50% by weight for detergent powder formulas. Agent builders inorcanigues

. polyphosphates (tripolyphosphates, pyrophosphates, orthophosphates, hexametaphosphates) of alkali metals, ammonium or alkanolamines

. tetraborates or borate precursors;

. silicates, in particular those having an Siθ2 Na2θ ratio of the order of 1.6 / 1 to 3.2 / 1 and the lamellar silicates described in US-A-4,664,839;

. alkali or alkaline earth carbonates (bicarbonates, sesquicarbonates); . cogranules of hydrated alkali metal silicates and alkali metal carbonates (sodium or potassium) rich in silicon atoms in Q2 or Q3 form, described in EP-A-488 868;

. crystalline or amorphous aluminosilicates of alkali metals (sodium, potassium) or ammonium, such as zeolites A, P, X ...; Zeolite A with a particle size of the order of 0.1-10 micrometers is preferred.

Organic builders

. water-soluble polyphosphonates (ethane 1-hydroxy-1, 1-diphosphonates, methylene salts diphosphonates ...);

. the water-soluble salts of carboxylic polymers or copolymers or their water-soluble salts such as:

. polycarboxylate ethers (oxidisuccinic acid and its salts, monosuccinic acid tartrate and its salts, disuccinic acid tartrate and its salts); . hydroxypolycarboxylate ethers; . citric acid and its salts, mellitic acid, succinic acid and their salts. the salts of polyacetic acids (ethylenediaminetetraacetates, nitrilotriacetates, N- (2 hydroxyethyl O-nitrilodiacetates);. C5-C20 alkyl succinic acids and their salts (2-dodecenylsuccinates, lauryl succinates,.) polyacetal esters, carboxylic acid;. polyaspartic, polyglutamic acid and their salts, polyimides derived from the polycondensation of aspartic acid and / or glutamic acid;

. polycarboxymethylated derivatives of glutamic acid or other amino acids. These agents can be combined with at least one of the anti-fouling or anti-redeposition agents mentioned below. Mention may also be made of non-oxygenated bleaching agents, acting by photoactivation in the presence of oxygen, agents such as sulfonated aluminum and / or zinc phthalocyanines. Anti-fouling agents

They can be used in amounts of approximately 0.01-10%, preferably approximately 0.1 -5%, and more preferably of the order of 0.2-3% by weight.

Mention may more particularly be made of agents such as:. cellulose derivatives such as cellulose hydroxyethers, methylcellulose, ethylcellulose, hydroxypropyl methylcellulose, hydroxybutyl methylcellulose;

. polyvinyl esters grafted on polyalkylene trunks such as polyvinylacetates grafted on polyoxyethylene trunks (EP-A-219 048); . polyvinyl alcohols;

. polyester copolymers based on ethylene terephthalate and / or propylene terephthalate and polyoxyethylene terephthalate units, with a molar ratio (number of units) ethylene terephthalate and / or propylene terephhalate / (number of units) polyoxyethylene terephthalate of the order of 1/10 to 10/1, preferably of the order of 1/1 to 9/1, the polyoxyethylene terephthalates having polyoxyethylene units having a molecular weight of the order of 300 to 5000, preferably of the order of 600 to 5000 (US-A-3 959 230, US-

A-3 893 929, US-A-4 116 896, US-A-4702 857, US-A-4770 666); . sulfonated polyester oligomers obtained by sulfonation of an oligomer derived from ethoxylated allyl alcohol, dimethyl terephthalate and 1,2-propylene diol, having from 1 to 4 sulfonated groups (US Pat. No. 4,968,451); . polyester copolymers based on propylene terephthalate and polyoxyethylene terephthalate units and terminated with ethyl, methyl units

(US-A-4,711,730) or polyester oligomers terminated by alkylpolyethoxy groups (US-A-4,702,857) or anionic sulfopolyethoxy groups (US-A-4,721,580), sulfoaroyl (US-A-4,877 896); . sulfonated polyester copolymers derived from terephthalic, isophthalic and sulfoisophthalic acid, anhydride or diester and a diol (FR-A-2 720 399).

Anti-redeposition agents.

They are used in amounts generally of approximately 0.01-10% by weight for a powdered detergent composition, of approximately 0.01-5% by weight for a liquid detergent composition. Mention may in particular be made of agents such as:

. ethoxylated monoamines or polyamines, polymers of ethoxylated amines (US-A-4,597,898, EP-A-11,984); . carboxymethylcellulose;

. the sulfonated polyester oligomers obtained by condensation of isophthalic acid, of dimethyl sulfosuccinate and of diethylene glycol

(FR-A-2 236 926); . polyvinylpyrollidones. Chelating agents

The iron and magnesium chelating agents are in amounts of the order of 0.1-10%, preferably of the order of 0.1-3% by weight. We can mention among others:. aminocarboxylates such as ethylenediaminetetraacetates, hydroxyethylethylenediaminetriacetates, nitrilotriacetates; . aminophosphonates such as nitrilotris- (methylenephosphonates); . polyfunctional aromatic compounds such as dihydroxy-disulfobenzenes. Polymeric dispersing agents.

They are in an amount of the order of 0.1-7% by weight, to control the hardness of calcium and magnesium, agents such as. the water-soluble salts of polycarboxylic acids with a molecular mass of the order of 2000 to 100,000, obtained by polymerization or copolymerization of ethylenically unsaturated carboxylic acids such as acrylic acid, maleic acid or anhydride, fumaric acid, itaconic acid, acid aconitic, mesaconic acid, citraconic acid, methylenemalonic acid, and in particular polyacrylates with a molecular mass of the order of 2,000 to 10,000 (US-A-3,308,067), copolymers of arylic acid and maleic anhydride molecular weight of the order of 5,000 to 75,000 (EP-A-66,915)

. polyethylene glycols of molecular mass of the order of 1000 to 50,000. Fluorescent agents (brighteners).

They are in an amount of about 0.05-1.2% by weight, agents such as: stilbene derivatives, pyrazoline, coumarin, fumaric acid, cinnamic acid, azoles, methinecyanins, thiophenes ... ("The production and application of fluorescent brightening agents "- M. Zahradnik, published by John Wiley & Sons, New York -1982). Foam suppressants.

They are in quantities of up to 5% by weight, agents such as:. Cιrj-C-24 monocarboxylic fatty acids or their alkali, ammonium or alkanolamine salts, fatty acid triglycerides; . aliphatic, alicyclic, aromatic or heterocyclic saturated or unsaturated hydrocarbons, such as paraffins, waxes; . N-alkylaminotriazines; . monostearylphosphates, monostearylalcoholphosphates;

. polyorganosiloxane oils or resins optionally combined with silica particles. Softening agents

They are in amounts of about 0.5-10% by weight, agents such as clays. Enzymes

They are in an amount which can range up to 5 mg by weight, preferably of the order of 0.05-3 mg of active enzyme / g of detergent composition, enzymes such as:. proteases, amylases, lipases, cellulases, peroxidases (US-A-3,553,139, US-A-4,101,457, US-A-4,507,219, US-A-4,261,868). Other additives

We can cite among others:. buffering agents,. perfumes,

. pigments. According to a particular embodiment of the invention, the antioxidant system coated in a detergent composition can be used without an oxidizing system and in particular without perborate.

Such detergent compositions involve the ingredients listed above with the exception of the bleaching system which is absent. They include surfactants which are preferably amphoteric, and low alkalinity builders such as, for example, citrate, sulfate or tripolyphosphate. There is generally the presence of anti-fouling and / or anti-redeposition agents and polyvinylpyrrolidones. Examples of such detergent compositions for washing colored laundry are given below:

- anionic surfactant (alkylbenzenesulfonate, sulfated fatty alcohol) 0 to 15%

- nonionic surfactant (polyoxyethylene fatty alcohol) 1 to 25%

- soap 1 to 5%

- cationic surfactant (dialkyldimethylammonium chloride) 0 to 5%

- sodium tripolyphosphate

- sodium silicate 25 to 40%

- anti-redeposition agents 2 to 9%

- enzymes 0.1 to 1.5%

- optical brighteners 0 to 0.4%

- dyes, fragrances 0 to 0.2%

- loads and water qs 100%

According to the invention, the coated antioxidant system can be implemented during a washing operation by means of a powder or liquid washing formulation (detergent composition), the treatment medium consisting of the washing bath.

Detergent compositions, with or without an oxidizing system, in powder or liquid form, can contain about 0.1 to 5% of their weight, preferably 0.2 to 2% of said antioxidant system expressed as an anti-agent. -oxidizer.

Thus, the textiles are brought into contact with the antioxidant system coated during washing with a detergent composition comprising it, generally used at a rate of 0.3 to 10 g per liter of bath, preferably around 5 g. / l.

According to a variant of the invention, the coated antioxidant system can also be used for rinsing and / or softening by means of a liquid formulation for rinsing and / or softening articles, the treatment being constituted by the rinsing and / or softening bath. The liquid rinsing and / or softening compositions may contain on the order of 0.02 to 20% of their weight of said coated antioxidant system expressed as antioxidant agent.

Besides said anti-fouling agent, other additives of the type may be present.

- associations of cationic surfactants (triethanolamine diester quaternized with dimethylsulfate, N-methylimidazoline tallow methyl sulfate ester, etc.) optionally combined with nonionic surfactants (ethoxylated fatty alcohols); - optical brighteners;

- dyes,

- perfumes,

- solvents, especially alcohols (methanol, ethanol, propanol, isopropanol, ethylene glycol, glycerin) - foam limiters.

By way of illustration, a softening formulation for the laundry is given:

- dialkyldimethylammonium chloride 1 to 9%

- 1.5% alkylbenzyldimethylammonium chloride O

- methyl and alkylimidazolinium sulfate 40 to 50%

- methyl and methyl-bis (alkylamidoethyl) sulfate -2- 0 to 3% hydroxyethylammonium

- ethoxylated alcohol, ethoxylated nonylphenol 0 to 3%

- optical brighteners 0.1 to 0.2%

- preservative 0.1 to 0.5%

- dyes, perfumes

- water qs 100%

Another mode of bringing textiles into contact with the coated antioxidant system can be done in a post-washing operation such as for example when drying the laundry in an appropriate drying machine.

The coated antioxidant system can be introduced on drying into the damp linen to be dried, by means of a solid support constituted for example by a strip of nonwoven fabric impregnated with said agent, support which may contain approximately 20% of its weight of coated antioxidant system expressed as antioxidant.

Furthermore, the applicant has found during its research that the protection system according to the invention has another function. It is a protective effect of colors against discoloration of colored fabrics when exposed to bright light, for example during drying in the sun, or when wearing clothes outside in a light containing UV rays.

This very advantageous additional advantage for the protection of colored articles is due to the fact that the antioxidant agents included in the coated antioxidant system, in particular vanillin and ethylvanillin, remain physically adsorbed sufficiently strongly on the cottons, for not to be eliminated during the rinses which necessarily follow the washing phase during which they are brought into contact with the items to be washed. They are therefore present on the surface of articles, probably in monomolecular or close layers, during drying and / or wearing articles with exposure to natural light.

Examples are given below highlighting the color protection effect. The protective color effect provided by the use of the coated antioxidant system according to the invention appears from the first wash, but it is all the more evident when the number of washes is repeated.

To this end, a series of washes is carried out and the bleaching effect is evaluated with or without the system of the invention. A series of tests is also carried out to assess the bleaching effect of a detergent composition comprising the additive of the invention.

Examples:

Description of multi-cycle washing tests: Evaluation of the bleaching effect Washing tests are carried out in a laboratory apparatus

Tergotometer well known in the profession of formulators of detergent compositions. The device simulates the mechanical and thermal effects of washing machines of the American type with pulsator, but thanks to the presence of 6 washing pots, it allows to carry out series of simultaneous tests with an appreciable saving of time.

For fading or wear tests, the principle is to accumulate several washes in succession on the same fabric test pieces, so as to accentuate and make visible or measurable the negative effects that one seeks to highlight. The colored cottons chosen for the fading or fading experiments come from a batch colored in red by a "direct" dyeing process, supplied by the CFT laboratory (Holland).

We cut test pieces of dimensions 10X10 cm. The color of these test pieces is measured quantitatively using a Dr. Lange reflectometer, which provides the Lab trichromatic coordinates used to define the color in question.

The colors of the cotton test pieces, washed and rinsed 6 times in succession, are again measured and the figures obtained are compared with the original figures.

The precise conditions for multi-washing are as follows:

- number of red test tubes per jar of the Tergotometer: 2 (10X10 cm)

- water volume: 1 liter - water: either deionized water (examples 1 to 7), or water of French hardness 30 ° TH

(examples 8 to 14) obtained by appropriate dilution of mineral water from the Contrexéville® brand.

- washing temperature: 60 ° C

- wash time: 25 min - Tergotometer stirring speed: 100 RPM

- three rinses with cold tap water (around 25 ° TH)

- detergent concentration: 5 g / l

- composition of the detergent formulation:

. linear sodium alkylbenzenesulfonate (LABS NANSA) 6%

. sodium sulfated alcohol - linear C12 (SULFOPON TA85) 4%

. ethoxylated alcohol C12, 70E (SINPERONIC A7) 5%

. zeolite 4A 25%

. cogranulate carbonate / silicate ratio 2 (Nabion®) 20%

. sodium sulfate qs%

. sodium carboxymethyl cellulose 1%. antioxidant system according to the invention 0 - 0.5 or 1%

Examples 1 to 7

Table I gives the results obtained after 6 washes with deionized water, first in the absence of a protective system (example 1), then in the presence of:

- "naked" vanillin, 0.5 and 1% in formulation (Examples 2 and 3);

- vanillin coated with 20% of a sodium salt of fatty acid C22 (behenic acid) added in the same proportions as previously in the detergent formula (Examples 4 and 5);

- Ethylvanillin coated with 20% glycerol monostearate (Myvaplex 600®), also the same proportions (examples 6 and 7). A procedure is given below for the preparation of the coated vanillin used in examples 4 and 5 and the coated ethyl vanillin of examples 6 and 7.

Vanillin coated with the sodium salt of behenigic acid.

1 - Preparation of an emulsion based on behenic acid and sodium hydroxide:

In a 1 liter glass container:

0.2951 mol of behenic acid is loaded and melted with magnetic stirring. Once melted, an aqueous solution containing 0.0074 mol of sodium hydroxide in 300 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 behenic acid.

This charge is emulsified at 87 ° C with polytron for 2 min (turbine speed: 13000 rpm) it is then maintained at 85 ° C with stirring during the whole test.

2 - Treatment of vanillin:

400 g of vanillin powder are loaded into a GLATT GPC G1 type 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 GPC G1 device on the bed of fluidized particles by a stream of air.

The following coating conditions are applied:

- fluidization air flow: 80 m ^ / h - powder temperature: 36 - 44 ° C

- spraying air pressure: 1.5 bar

- spraying air temperature: 70-84 ° C

- emulsion temperature: 85 ° C

- flow rate of the coating emulsion: 11 g / min - duration of spraying: 55 min

- drying: 18 min

- powder temperature during drying: 45 to 30 ° C Total amount of sprayed emulsion: 600 g

433 g of coated vanillin are recovered with a level of coating agent of 20% relative to the final product. Ethylvanillin coated with glycerol monostearate.

The coated ethylvanillin of Examples 6 and 7 can be prepared in the same way.

1 - Preparation of an emulsion based on glycerol monostearate (Myvaplex 600®):

In a 1 liter glass container:

100.5 g of Myvaplex are dispersed in 400 g of distilled water preheated to 69 ° C with magnetic stirring. This charge is emulsified at 63 ° C. with a polytron for 30 s (turbine speed: 8000 rpm), it is then kept at 63 ° C. with stirring throughout the test.

2 - Treatment of ethylvanillin:

In a fluidized bed apparatus of the GLATT GPC G1 type equipped with a Wurster, 400 g of ethyl vanillin powder 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: 36 - 44 ° C

- spraying air pressure: 2 bar

- spraying air temperature: 61 ° C

- emulsion temperature: 63 ° C

- flow rate of the coating emulsion: 8 g / min - duration of the spraying: 97 min

- drying: 10 min

- powder temperature during drying: 38 ° C Total amount of sprayed emulsion: 800 g

480 g of ethylvanillin coated are recovered with a coating agent content of 20% relative to the final product. Table I

The evolution of the Lab values of red cotton is corroborated by visual examination.

In fact, the fading of red results in both an increase in the L value (more "clear" appearance) and in a lowering of the red a coordinate (less intense red).

The positive results are already visible to the eye with the test carried out in deionized water. All the antioxidants tested allow above all to maintain the a coordinate, or else the L coordinate, but visually, the colors are better preserved in the presence of the antioxidants.

Examples 8 to 14

Table II gives the results obtained in hard water and containing transition cations, with the same detergent compositions.

Table II

The differences observed in this test carried out in hard water are much larger and significant, probably because of the more violent effect of the oxidizing system, this more violent effect is itself due to the presence of various cations in the water of washing.

The example as described uses a detergent formulation with a bleaching system, but the complexing additives have been omitted intentionally. Recall that these inhibit the catalytic effects of the cations present in the washing bath as impurities and could reduce the sensitivity of the test.

The loss of color undergone by the control sample washed six times without a protection system is significant and results in a sharp rise in the value L, from 33.5 to 42.4 and a reduction in the coordinate a, from 49, 2 to 44.8.

This example in hard water also highlights the significant advantage provided by the coating agent of the antioxidant agent with a product which makes it possible to release it with a delayed effect, probably after the melting and dispersion of this coating.

Vanillin and ethyl vanillin, if coated, give remarkable protection of the red color from 0.5% active added to the bleaching composition.

Although this is not the protection mechanism, it will also be noted that the products according to the invention can make it possible to replace the organic complexing agents of the transition metals.

Description of the washing test to measure the performance of the bleaching effect

The measurement of detergency and bleaching performance is also carried out using the Tergotometer, but on a single wash, using fabrics soiled in a standard manner, the level of soiling and cleaning of which is still quantified by a reflectance measurement. in trichromatic coordinates

Lab, before and after washing, the difference ΔE between the two measurements being the performance index used.

The standardized soiling used, as well as the nature of the textiles which serve as support, are as follows: 1-BC3 - 016 - THE / COTTON

2-CS2 - 014 - COCOA / COTTON

3-CS1 - 027 - BLOOD / COTTON

4-BC2 - 016 - COFFEE / COTTON

5-EMPA - SUNAK / COTTON

6-CS3 - 029 - WINE / COTTON

7-E PA104-OIL INK / COTTON POLYESTER

8-K20D - 14.11 - SEBUM / POLYESTER COTTON

9-K30D - P030 - SEBUM / POLYESTER

Soils 1 to 6 specifically respond to the bleaching effects of detergent compositions. These are "oxidizable" soiling.

Soils 7 to 9 are greasy and particulate soils which respond to the emulsification and dispersion effects provided by the surfactants and builders of the detergent formulation.

The precise conditions of the washing test are as follows:

- washing temperature: 40 ° c

- wash time 20 min

- washing water: hardness 30 ° TH obtained by diluting Contrexéville mineral water

- three cold water rinses hardness 25 ° TH

- detergent concentration: 5 g / l

- 2 test tubes of each soiling per pot of Tergotometer.

Examples 15 to 17

Table III gives the detergent formulations which are the subject of the performance evaluation, as well as the results obtained.

Table III

VS

It should be noted that the level of 1% of vanillin coated with behenic acid does not appreciably decrease the level of whitening and detergent performance.

Uncoated vanillin significantly reduces performance. It is therefore noted that the coating is preferable for maintaining the washing and bleaching performance as it was also useful for maintaining the quality of the coloration of the red colored cotton.

The following method is applied to measure the protective effects against sunlight.

Washing tests are carried out with a formulation identical to that of the preceding examples in which the oxidizing system was removed, which was replaced by sodium sulfate.

Three comparative tests are carried out by washing with detergent without oxidizing agent as such, then with this same composition with 2% ethylvanillin on the one hand and 2% vanillin on the other hand, coated respectively with monostearate glycerol and behenic acid according to the procedure of Example 1.

In this case, only two cumulative washes are carried out under the same conditions as above, with 2 rinses with hard, cold water after each wash.

After drying in an oven protected from light, a test tube (out of the two which are the subject of each test) is subjected to accelerated aging in light using a device called Suntest CPS + ® which, thanks to to a xenon arc lamp system and special filters performs an optimal simulation of solar radiation: the wavelength ranging from 300 to 800 nm. The exposure of the test piece is 4 hours.

Examples 18 to 21 The results recorded in the following Table IV show the protective effect of the additives used: Table IV

Additive 1 is vanillin (coated) added at 2% in the formulation.

Additive 2 is ethylvanillin (coated) added at 2% in the formulation.

Contrary to the effects noted for the action of oxidants in washing, it is noted that the change in color due to exposure is mainly noticed by the modification of the value a, indicative of the red color, which decreases under the radiation effect, from 50.7 to 44.

With the additives tested, the evolution of a is weaker or almost zero, with evolution from 50.7 to 48.5 or 49.2.

The overall visual impression felt on examination of the cotton test tubes confirms the protective effect measured by the use of the Lab system.

Claims

1 - Use of a coated antioxidant system comprising an antioxidant agent and a coating agent in order to ensure the protection of the colors of textiles during washing, in a detergent composition with or without an oxidizing system and or in a composition intended for postwashing operations.

2 - Use according to claim 1 of an antioxidant system coated in a rinsing and / or softening composition or deposited on a support during a mechanical operation for drying the laundry.

3 - Use according to one of claims 1 and 2 characterized in that the antioxidant is a compound capable of inhibiting the process of auto-oxidation by free radicals and that it is capable of dissolving or to disperse in water and to adsorb on the textile fibers.

4 - Use according to one of claims 1 to 3 characterized in that the antioxidant is a phenolic compound and / or its ether.

5 - Use according to claim 4 characterized in that the phenolic compound corresponds to the following formula (I):

in said formula: - n, number of substituents, is a number less than 4, preferably between 1 and 3, - R represents one of the following atoms, groups or functions:. a hydrogen atom,. a hydroxyl group,. an alkyl radical, linear or branched, having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl,. a linear or branched alkenyl radical having from 2 to 6 carbon atoms, preferably from 2 to 4 carbon atoms, such as vinyl, allyl,

. a linear or branched alkoxy radical having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms such as the methoxy, ethoxy, propoxy, isopropoxy, butoxy radicals,

. an acyl group having from 2 to 6 carbon atoms,. a formyl group.

6 - Use according to one of claims 1 to 5 characterized in that the antioxidant is vanillin and / or its derivatives.

7 - Use according to one of claims 1 to 6 characterized in that the antioxidant is selected from: hydroquinone, pyrocatechin, methylhydroquinone, tert-butylhydroquinone, tert-butylcatechol, ditert- butylhydroquinone, 2,4-dimethyl-6-tert-butylphenol, salicylic aldehyde, butylhydroxyanisole, vanillin ((3-methoxy-4-hydroxy-benzaldehyde), ethylvanillin (3-ethoxy-4-hydroxybenzaldehyde) , isovanillin (4-methoxy-3-hydroxybenzaldehyde), o-vanillin (3-methoxy-2-hydroxy-benzaldehyde), syringic aldehyde (3,5-dimethoxy-4-hydroxybenzaldehyde), aldehyde veratric (3,4-dimethoxybenzaldehyde), 3,4,5-trimethoxy-benzaldehyde.

8 - Use according to one of claims 1 to 7 characterized in that the antioxidant is chosen from: vanillin, orthovaniilin, isovanillin, ethylvanillin, butylhydroxyanisole.

9 - Use according to one of claims 1 to 8 characterized in that the antioxidant is vanillin and / or ethylvanillin used in pulverulent, platelet or pearl form.

10 - Use according to one of claims 1 to 9 characterized in that the coated antioxidant system comprises an antioxidant agent and a coating agent having a melting point of at least 30 ° C, varying from preferably between 30 ° C and 70 ° C, and even more preferably between 40 ° C and 60 ° C.

11 - Use according to claim 10 characterized in that the coating agent is chosen from the following compounds and their mixtures: fatty acids, fatty alcohols, ethoxylated alcohols solid at room temperature, mass polyethylene glycol molecular values greater than 1000, solid paraffins, gelatin, polysaccharides, chitin, chitosan and fatty substances. 12 - Use according to one of claims 10 and 11 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.

13 - Use according to one of claims 10 to 12 characterized in that the coating agent is chosen from the following compounds and their mixtures

: fatty substances, preferably esters of optionally acetylated fatty acids, optionally salified fatty acids. 14 - Use according to one of claims 1 to 13 characterized in that the coated antioxidant system is composed of 50 to 95%, preferably, from 70 to 90% by weight of an antioxidant agent, and from 5 to 50%, preferably from 10 to 30% by weight of a coating product.

15 - Whitening composition comprising a whitening system and a coated antioxidant system described in one of claims 3 to 14.

16 - Composition according to claim 15 characterized in that it comprises from 0.2 to 10% by weight, preferably from 2 to 5% of coated antioxidant system expressed as antioxidant.

17 - Composition according to claim 15 characterized in that the bleaching system comprises a bleaching agent, preferably, a compound, optionally associated with a bleaching activator.

18 - Composition according to one of claims 15 to 17 characterized in that the bleaching agent is a per-compound such as a perborate preferably, sodium perborate monohydrate or tetrahydrate; a peroxygen compound preferably, sodium carbonate peroxyhydrate, pyrophosphate peroxyhydrate, urea peroxyhydrate, sodium peroxide, sodium persulfate.

19 - Composition according to one of claims 15 to 18 characterized in that the bleaching activator is tetraacetylethylenediamine, tetraacetylmethylenediamine, tetraacetylglycoluryl, sodium p-acetoxybenzene sulfonate, pentaacetylglucose, octaacetyllactose.

20 - Composition according to one of claims 15 to 19 characterized in that the bleaching composition comprises at least one bleaching agent in an amount of 65 to 90% by weight, preferably from 80 to 88% and optionally an activator bleach present in an amount of 0 to 25% by weight, preferably 10 to 15%.

21 - Detergent composition with or without an oxidizing system comprising a coated antioxidant system comprising an antioxidant and a coating agent in order to protect the colors of textiles during washing. 22 - detergent composition according to claim 21 characterized in that it comprises a coated antioxidant system comprising an antioxidant agent and a coating agent, in an amount of 0.1 to 5% by weight, preferably 0.2 to 2%.

23 - Rinsing and / or softening composition comprising a coated antioxidant system comprising an antioxidant and a coating agent in order to protect the colors of the textiles during washing.

24 - Composition according to claim 23 characterized in that it comprises a coated antioxidant system, at a rate of 0.02 to 20% by weight expressed as antioxidant agent.

25 - Post-washing composition comprising a coated antioxidant system comprising an antioxidant agent and a coating agent in order to ensure the protection of the colors of the textiles, intended preferably to be used during the mechanical drying of the laundry.

26 - Composition according to claim 25 characterized in that the coated antioxidant system is introduced on drying in the damp linen to be dried, by means of a solid support, preferably a strip of impregnated nonwoven fabric of said agent.

27 - Composition according to one of claims 21 to 26 characterized in that the coated antioxidant system is as described in claims 3 to 14.

28 - Method for treating the surface of textile articles, by depositing on said articles, during one or more washing, rinsing and / or softening or drying operations, of a coated antioxidant system comprising an antioxidant and a coating agent.

29 - Process according to claim 28 characterized in that said coated antioxidant system is implemented during a washing operation by means of a washing formulation in powder or liquid containing of the order of 0 , 1 to 5% of its weight of said system expressed as an antioxidant. 30 - Process according to claim 28 characterized in that said coated antioxidant system is implemented during a rinsing and / or softening operation by means of a rinsing and / or softening formulation containing order from 0.02 to 20% of its weight of said system expressed as an antioxidant.

31 - Method according to claim 28 characterized in that said coated antioxidant system is implemented during a drying operation by means of a support consisting of a strip of nonwoven fabric impregnated with said antioxidant system coated.

32 - Method according to one of claims 28 to 31 characterized in that the coated antioxidant system is as described in claims 3 to 14.

33 - Use of a coated antioxidant system comprising an antioxidant agent and a coating agent with a view to ensuring the protection of colors against discoloration of colored fabrics when exposed to bright light, in particular during drying at sun or when wearing clothing.

34 - Use according to claim 33 characterized in that the coated antioxidant system is as described in claims 3 to 14.

35 - Use according to one of claims 33 and 34 characterized in that the coated antioxidant system is deposited on the surface of the textile articles, during one or more operation (s) of washing, rinsing and / or softening or drying.

36 - Detergent composition for washing machine characterized in that it comprises vanillin and / or derivatives in the form of granules comprising a central core formed essentially of vanillin and / or derivatives in solid form surrounded by a peripheral layer formed essentially a coating agent which is solid at room temperature and which can change under the conditions for washing the laundry, in order to release the coated product under the effect of the rise in temperature, during the washing cycle.

37 Composition according to Claim 36, characterized in that the coated product is vanillin and / or ethylvanillin used in pulverulent, platelet or pearl form. 38 - Composition according to one of claims 36 and 37 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.

39 - Detergent composition according to claim 38 characterized in that the coating agent is as described in one of claims 11 to 13.

40 - Detergent composition according to one of claims 36 to 39 characterized in that the level of coating agent relative to vanillin and / or derivatives, is between 5 and 50%, preferably between 10 and 30% by weight.