EP3134500B1 - Washing or cleaning agents with electrochemically activatble anionic mediator compounds - Google Patents

Description

The present invention relates to the use of certain organic mediator compounds for enhancing the cleaning performance of detergents and cleaners against stains, washing or cleaning processes using bleach-active species produced from such mediator compounds and detergents and cleaners containing the mediator compound.

Inorganic peroxygen compounds, particularly hydrogen peroxide and solid peroxygen compounds which dissolve in water to release hydrogen peroxide, such as sodium perborate and sodium carbonate perhydrate, have long been used as oxidizing agents for disinfecting and bleaching purposes. The oxidation effect of these substances in dilute solutions depends strongly on the temperature; Thus, for example, with H ₂ O ₂ or perborate in alkaline bleaching liquors only at temperatures above about 80 ° C, a sufficiently fast bleaching of soiled textiles. At lower temperatures, the oxidation effect of the inorganic peroxygen compounds can be improved by adding so-called bleach activators which are able to provide peroxycarboxylic acids under the abovementioned perhydrolysis conditions and for the numerous proposals, especially from the classes of N- or O-acyl compounds, for example reactive Esters, polyacylated alkylenediamines, in particular N, N, N ', N'-tetraacetylethylenediamine (TAED), acylated glycolurils, in particular tetraacetylglycoluril, N-acylated hydantoins, hydrazides, triazoles, hydrotriazines, urazoles, diketopiperazines, sulphurylamides and cyanurates, and also carboxylic anhydrides, in particular, phthalic anhydride, carboxylic acid esters, especially sodium nonanoyloxy-benzenesulfonate (NOBS), sodium isononanoyloxy-benzenesulfonate, O-acylated sugar derivatives such as pentaacetyl-glucose, and N-acylated lactams such as N-benzoyl-caprolactam have become known in the literature. By adding these substances, the bleaching action of aqueous peroxide liquors can be increased so much that even at temperatures around 60 ° C substantially the same effects as with the peroxide solution alone at 95 ° C occur.

In the effort to achieve energy-saving washing and bleaching processes, in addition, application temperatures still gain significantly less than 60 ° C., especially below 45 ° C., down to the cold water temperature in recent years.

At these low temperatures, the effect of the previously known activator compounds usually decreases noticeably. There has therefore been no lack of efforts to develop more effective activators for this temperature range. There are also various uses of transition metal compounds, in particular transition metal complexes have been proposed to increase the oxidation power of peroxygen compounds or atmospheric oxygen in detergents and cleaners. The transition metal compounds proposed for this purpose include, for example, manganese, iron, cobalt, ruthenium or molybdenum-salene complexes, manganese, iron, cobalt, ruthenium or molybdenum carbonyl complexes, manganese, iron, cobalt, Ruthenium, molybdenum, titanium, vanadium and copper complexes with nitrogen-containing tripod ligands, and manganese complexes with polyazacycloalkane ligands, such as TACN. However, a disadvantage of such metal complexes is that they either do not have sufficient bleaching performance, in particular at low temperature, or, if the bleaching performance is adequate, undesirably damage the colors of the material to be washed or cleaned and possibly even of the material itself, for example the textile fibers, can come.

From the international patent application WO 2013/017476 A1 It is known that from sterically hindered N-hydroxy compounds such as 1-hydroxy-2,2,6,6-tetramethylpiperidine bleaching-active species can be produced by electrolysis, which have a bleach-enhancing effect.

Surprisingly, it has now been found that the effect of such mediator compounds can be increased even if they carry an anionic substituent.

An object of the invention is accordingly the use of electrolytically by a redox reaction of anionically substituted 1-hydroxy-2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine-N-oxide or (2,2 , 6,6-Tetramethylpiperidin-1-yl) oxy generated bleaching-active species to enhance the cleaning performance of detergents and cleaners, especially bleachable and / or protein-containing stains, in aqueous, especially surfactant-containing liquor.

The anionic substituent in the 2,2,6,6-tetramethylpiperidine derivatives essential to the invention is preferably selected from the SO ₃ ^- group, the CO ₂ ^- group, the PO ₃ ^2- group and mixtures thereof. The anionic substituent may be attached directly or preferably via a spacer to a carbon atom of the piperidinyl ring. A spacer is preferably selected from alkylene groups, aminoalkylene groups, oxyalkylene groups, aminocarbonylalkylene groups, oxycarbonylalkylene groups each having 1 to 25 C atoms, and mixtures thereof. If desired, a molecule may also carry a plurality of anionic substituents; if desired, these may be located on a spacer or on a plurality of spacers. In the anionically substituted 2,2,6,6-tetramethylpiperidine derivative, counter cations such as hydrogen, alkali metal, alkaline earth metal and / or ammonium ions are present in a number balancing the negative charge of the anionic group or groups. Preferred 2,2,6,6-tetramethylpiperidine derivatives include those bearing an ester or amide linkage at position 4 wherein the anionic substituent is on the moiety derived from the carboxylic acid. These are accessible from 4-hydroxy or 4-amino-2,2,6,6-tetramethylpiperidine N-oxide or the corresponding hydroxylamine compounds or the corresponding oxyl radicals.

The preparation of the bleaching-active species can be carried out in a simple manner by adding an aqueous system containing the mediator compound to an electrical potential difference applied between at least two electrodes, which is preferably 0.2 V to 5 V, in particular 1 V to 3 V, submits so that the mediator compound gives off an electron. Without wishing to be bound by this theory, it is conceivable that a radical or N-oxoammonium species produced in this way reaches the dirt with the aqueous liquor, removes an electron from the soiling and thus turns the soiling into a less colored and / or better water-soluble and / or or dispersible material is formed. The mediator compound is reformed from the bleaching-active species by reaction with the soil so that a reversible redox system is present. It is possible to electrolyze the liquor containing the mediator compound continuously or once or several times for certain periods, for example 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes or 60 minutes, the duration of the electrolysis being adapted to the degree of soiling of the laundry can be. The production of the bleaching-active species is also possible in that the mediator compound, in particular when using a conventional dispensing device, passes an electrolysis device before it enters the chamber of a washing machine or dishwashing machine, in particular in aqueous solution or slurry flows through an electrolysis cell which is in the feed line can be mounted inside or outside the machine. Alternatively, it is possible at the beginning of the process, other active ingredients, such as enzymes, unaffected perform their performance, and only later by switching on the electrolysis device to start the bleaching effect.

In a preferred embodiment of the invention, the electrolysis device is installed inside a washing or dishwashing machine in the flooded area of the washing or cleaning room, in a drum washing machine preferably outside the washing drum. The device may be a permanently installed component of the washing machine or dishwashing machine or a separate component. The electrolysis device designed in particular as an electrolysis cell is embodied in a further embodiment of the invention as a separate device separate from a washing machine or dishwashing machine, which device is operated with its own power source, for example a battery (e-bleach-ball). Another embodiment of the invention is to integrate the electrolyzer in an additional water cycle within the machine. In all embodiments, it is important that the electrodes of the electrolyzer may contact the electrolyte (washing liquor, or service water supplied) containing the mediator compound, for example, when the e-bleach ball is in the wash process in the washing drum of a washing machine located.

Further objects of the invention are a process for washing textiles and a process for cleaning hard surfaces, in particular for machine cleaning of dishes, using an electrolytically by a redox reaction of anionically substituted 1-hydroxy-2,2,6,6- Tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine N-oxide or (2,2,6,6-tetramethylpiperidin-1-yl) oxyl produced bleaching-active species in aqueous liquor.

It is particularly advantageous that the activity of the bleach, if desired, depending on the degree of contamination or tissue, can be easily modified by controlling the current intensity. In the case of textile washing processes, there is no damage to the textile treated in this way, which exceeds that which occurs when conventional means are used.

Within the context of the use according to the invention and the method according to the invention, it is preferred if the concentration of the mediator compound in the aqueous washing or cleaning liquor is 0.05 mmol / l to 5 mmol / l, in particular 0.1 mmol / l to 2 mmol / l. The use according to the invention and the process according to the invention are in each case preferably carried out at temperatures in the range from 10 ° C. to 95 ° C., in particular from 20 ° C. to 40 ° C. The use according to the invention and the method according to the invention are in each case preferably carried out at pH values in the range from pH 2 to pH 12, in particular from pH 4 to pH 11.

The use according to the invention or the method according to the invention can be realized particularly simply by the use of a washing or cleaning agent which contains the mediator compound. Detergents for cleaning textiles and agents for cleaning hard surfaces, in particular dishwashing detergents, and among these preferably those for machine use, containing a mediator compound in the form of anionically substituted anionically substituted 1-hydroxy-2,2,6,6-tetramethylpiperidine, 2, 2,6,6-tetramethylpiperidine-N-oxide or (2,2,6,6-tetramethylpiperidin-1-yl) oxyl in addition to customary compatible ingredients, in particular a surfactant, are therefore further objects of the invention. Although the success of the invention is already established by the electrolytic production of the bleaching-active species, an agent according to the invention may additionally contain, in particular, peroxygen-containing bleaching agent. Of particular advantage, however, is that both bleach and conventional bleach activator can be dispensed with, so that as a result a smaller amount of detergent or cleaning agent must be used per wash or cleaning cycle. An agent according to the invention is therefore in a preferred embodiment free of bleach and conventional bleach activator.

Preferably, in agents according to the invention 0.05 wt .-% to 10 wt .-%, in particular 0.1 wt .-% to 5 wt .-% of the mediator compound. When using an inventive By means of which, if desired, the cleaning-enhancing effect of the mediator compound can be eliminated by omitting the electrolysis completely, if, for example, it is to be dispensed with only lightly soiled laundry or extremely bleach-sensitive textiles. The consumer therefore needs only a single detergent for washing insensitive, usually white and sensitive, usually colored textiles.

The compositions according to the invention, which can be in the form of homogeneous solutions or suspensions in particular as pulverulent solids, in densified particle form, may contain, in principle, all known ingredients customary in such agents, apart from the mediator compound to be used according to the invention. The agents according to the invention may in particular be builders, surface-active surfactants, water-miscible organic solvents, enzymes, sequestering agents, electrolytes, pH regulators, polymers with special effects, such as soil release polymers, dye transfer inhibitors, grayness inhibitors, wrinkle-reducing polymeric agents and form-retaining polymeric agents, bleaches, bleach activators, and other adjuvants, such as optical brighteners, foam regulators, dyes and fragrances.

The compositions of the invention may contain one or more surfactants, in particular anionic surfactants, nonionic surfactants and mixtures thereof, but also cationic and / or amphoteric surfactants may be included. Suitable nonionic surfactants are in particular alkyl glycosides and ethoxylation and / or propoxylation of alkyl glycosides or linear or branched alcohols each having 12 to 18 carbon atoms in the alkyl moiety and 3 to 20, preferably 4 to 10 alkyl ether groups. Also suitable are ethoxylation and / or propoxylation products of N-alkylamines, vicinal diols, fatty acid esters and fatty acid amides which correspond to said long-chain alcohol derivatives with respect to the alkyl moiety and of alkylphenols having 5 to 12 carbon atoms in the alkyl radical.

Suitable anionic surfactants are in particular soaps and those which contain sulfate or sulfonate groups with preferably alkali ions as cations. Usable soaps are preferably the alkali salts of the saturated or unsaturated fatty acids having 12 to 18 carbon atoms. Such fatty acids can also be used in incompletely neutralized form. Useful surfactants of the sulfate type include the salts of the sulfuric acid half-esters of fatty alcohols having 12 to 18 carbon atoms and the sulfation products of said nonionic surfactants having a low degree of ethoxylation. Suitable surfactants of the sulfonate type include linear alkylbenzenesulfonates having 9 to 14 carbon atoms in the alkyl moiety, alkane sulfonates having 12 to 18 carbon atoms, and olefin sulfonates having 12 to 18 carbon atoms, which are formed in the reaction of corresponding monoolefins with sulfur trioxide, and alpha-sulfofatty acid esters resulting from the sulfonation of fatty acid methyl or ethyl esters.

Such surfactants are present in the cleaning or washing agents according to the invention in proportions of preferably 5 wt .-% to 50 wt .-%, in particular from 8 wt .-% to 30 wt .-%, while the disinfectant according to the invention as well as inventive cleaning agent preferably 0.1 wt .-% to 20 wt .-%, in particular 0.2 wt .-% to 5 wt .-% surfactants.

worin jede Gruppe R¹ unabhängig voneinander ausgewählt ist aus C_1-6-Alkyl-, -Alkenyl- oder -Hydroxyalkylgruppen; jede Gruppe R² unabhängig voneinander ausgewählt ist aus C_8-28-Alkyl- oder -Alkenylgruppen; R³ = R¹ oder (CH₂)_n-T-R²; R⁴ = R¹ oder R² oder (CH₂)_n-T-R²; T = -CH₂-, -O-CO- oder -CO-O- und n eine ganze Zahl von 0 bis 5 ist. Die kationischen Tenside weisen übliche Anionen in zum Ladungsausgleich notwendiger Art und Anzahl auf, wobei diese neben beispielsweise Halogeniden auch aus den anionischen Tensiden ausgewählt werden können. In bevorzugten Ausführungsformen der vorliegenden Erfindung kommen als kationische Tenside Hydroxyalkyltrialkyl-ammonium-verbindungen, insbesondere C_12-18-Alkyl(hydroxyethyl)dimethylammoniumver-bindungen, und vorzugsweise deren Halogenide, insbesondere Chloride, zum Einsatz. Ein erfindungsgemäßes Mittel enthält vorzugsweise 0,5 Gew.-% bis 25 Gew.-%, insbesondere 1 Gew.-% bis 15 Gew.-% kationisches Tensid.The compositions according to the invention, especially those which are intended for the treatment of textiles, may contain, as cationic active substances with textile-softening action, in particular one or more of the cationic, fabric-softening substances of the general formulas X, XI or XII:

wherein each R ^{1 group is} independently selected from C _1-6 alkyl, alkenyl or hydroxyalkyl groups; each R ^{2 group is} independently selected from C _8-28 alkyl or alkenyl groups; R ³ = R ¹ or (CH ₂ ) _n -TR ² ; R ⁴ = R ¹ or R ² or (CH ₂ ) _n -TR ² ; T = -CH ₂ -, -O-CO- or -CO-O- and n is an integer from 0 to 5. The cationic surfactants have customary anions in the charge balance necessary type and number, which can be selected in addition to, for example halides also from the anionic surfactants. In preferred embodiments of the present invention, the cationic surfactants used are hydroxyalkyltrialkylammonium compounds, in particular C _12-18 -alkyl (hydroxyethyl) dimethylammonium compounds, and preferably their halides, in particular chlorides. An agent according to the invention preferably contains 0.5% by weight to 25% by weight, in particular 1% by weight to 15% by weight, of cationic surfactant.

An agent according to the invention preferably contains at least one water-soluble and / or water-insoluble, organic and / or inorganic builder. The water-soluble organic builder substances include polycarboxylic acids, in particular citric acid and sugar acids, monomeric and polymeric aminopolycarboxylic acids, in particular methylglycinediacetic acid, nitrilotriacetic acid and ethylenediaminetetraacetic acid and polyaspartic acid, polyphosphonic acids, in particular aminotris (methylenephosphonic acid), ethylenediaminetetrakis (methylenephosphonic acid) and 1-hydroxyethane-1,1-diene diphosphonic acid, polymeric hydroxy compounds such as dextrin and polymeric (poly) carboxylic acids, in particular by oxidation of polysaccharides or dextrins accessible polycarboxylates, and / or polymeric acrylic acids, methacrylic acids, maleic acids and copolymers thereof, which may also contain polymerized small amounts of polymerizable substances without carboxylic acid functionality. The molecular weight of the homopolymers of unsaturated carboxylic acids is generally between 5,000 and 200,000, of the copolymers between 2,000 and 200,000, preferably 50,000 to 120,000, each based on the free acid. A particularly preferred acrylic acid-maleic acid copolymer has a molecular weight of 50,000 to 100,000. Suitable, although less preferred, compounds of this class are copolymers of acrylic or methacrylic acid with vinyl ethers, such as vinylmethyl ethers, vinyl esters, ethylene, propylene and styrene, in which the acid content is at least 50% by weight. It is also possible to use terpolymers which contain two unsaturated acids and / or salts thereof as monomers and also vinyl alcohol and / or an esterified vinyl alcohol or a carbohydrate as the third monomer as water-soluble organic builder substances. The first acidic monomer or its salt is derived from a monoethylenically unsaturated C ₃ -C ₈ -carboxylic acid and preferably from a C ₃ -C ₄ -monocarboxylic acid, in particular from (meth) -acrylic acid. The second acidic monomer or its salt may be a derivative of a C ₄ -C ₈ -dicarboxylic acid, with maleic acid being particularly preferred, and / or a derivative of an allylsulfonic acid which is substituted in the 2-position by an alkyl or aryl radical. Such polymers generally have a molecular weight between 1,000 g / mol and 200,000 g / mol. Further preferred copolymers are those which have as monomers acrolein and acrylic acid / acrylic acid salts or vinyl acetate. The organic builder substances can be used, in particular for the preparation of liquid agents, in the form of aqueous solutions, preferably in the form of 30 to 50 percent by weight aqueous solutions. All of the acids mentioned are generally used in the form of their water-soluble salts, in particular their alkali metal salts.

If desired, such organic builder substances may be present in amounts of up to 40% by weight, in particular up to 25% by weight and preferably from 1% by weight to 8% by weight. Quantities close to the stated upper limit are preferably used in paste-form or liquid, in particular water-containing, agents according to the invention.

Suitable water-soluble inorganic builder materials are, in particular, polymeric alkali metal phosphates, which may be in the form of their alkaline neutral or acidic sodium or potassium salts. Examples of these are tetrasodium diphosphate, disodium dihydrogen diphosphate, pentasodium triphosphate, so-called sodium hexametaphosphate and the corresponding potassium salts or mixtures of sodium and potassium salts. In particular, crystalline or amorphous alkali metal aluminosilicates, in amounts of up to 50% by weight, preferably not more than 40% by weight, and in liquid agents, in particular from 1% by weight to 5% by weight, are used as water-insoluble, water-dispersible inorganic builder materials. used. Among these, preferred are the detergent grade crystalline sodium aluminosilicates, especially zeolite A, P and optionally X. Amounts near the above upper limit are preferably used in solid, particulate agents. In particular, suitable aluminosilicates have no particles with a particle size greater than 30 .mu.m and preferably consist of at least 80% by weight of particles having a size of less than 10 .mu.m. Their calcium binding capacity, according to the information of the German Patent DE 24 12 837 can be determined, is usually in the range of 100 to 200 mg CaO per gram.

Suitable substitutes or partial substitutes for the said aluminosilicate are crystalline alkali silicates which may be present alone or in a mixture with amorphous silicates. The alkali metal silicates useful as builders in the compositions according to the invention preferably have a molar ratio of alkali metal oxide to SiO ₂ below 0.95, in particular from 1: 1.1 to 1:12, and may be present in amorphous or crystalline form. Preferred alkali metal silicates are the sodium silicates, in particular the amorphous sodium silicates, with a molar ratio of Na ₂ O: SiO ₂ of 1: 2 to 1: 2.8. The crystalline silicates which may be present alone or in admixture with amorphous silicates, are crystalline layer silicates with the general formula of Na ₂ Si _x O used _{2x + 1} · y H ₂ O in which x, known as the modulus, an integer of 1, 9 to 4 and y is a number from 0 to 20 and preferred values for x are 2, 3 or 4. Preferred crystalline phyllosilicates are those in which x in the abovementioned general formula assumes the values 2 or 3. In particular, both β- and δ-sodium disilicates (Na ₂ Si ₂ O ₅ .yH ₂ O) are preferred. Also prepared from amorphous alkali silicates, practically anhydrous crystalline alkali silicates of the abovementioned general formula in which x is a number from 1.9 to 2.1, can be used in inventive compositions. In a further preferred embodiment of the composition according to the invention, a crystalline sodium layer silicate with a modulus of 2 to 3 is used, as can be prepared from sand and soda. Crystalline sodium silicates with a modulus in the range from 1.9 to 3.5 are used in a further preferred embodiment of compositions according to the invention. In a preferred embodiment of compositions according to the invention, a granular compound of alkali silicate and alkali carbonate is used, as is commercially available, for example, under the name Nabion® 15. If alkali metal aluminosilicate, in particular zeolite, is also present as an additional builder substance, the weight ratio of aluminosilicate to silicate, based in each case on anhydrous active substances, is preferably 1:10 to 10: 1. In agents containing both amorphous and crystalline alkali silicates The weight ratio of amorphous alkali metal silicate to crystalline alkali metal silicate is preferably 1: 2 to 2: 1 and especially 1: 1 to 2: 1.

Builder substances are preferably present in the detergents or cleaners according to the invention in amounts of up to 60% by weight, in particular from 5% by weight to 40% by weight.

1. a) 5 Gew.-% bis 35 Gew.-% Citronensäure, Alkalicitrat und/oder Alkalicarbonat, welches auch zumindest anteilig durch Alkalihydrogencarbonat ersetzt sein kann,
2. b) bis zu 10 Gew.-% Alkalisilikat mit einem Modul im Bereich von 1,8 bis 2,5,
3. c) bis zu 2 Gew.-% Phosphonsäure und/oder Alkaliphosphonat,
4. d) bis zu 50 Gew.-% Alkaliphosphat, und
5. e) bis zu 10 Gew.-% polymerem Polycarboxylat,

wobei die Mengenangaben sich auf das gesamte Wasch- beziehungsweise Reinigungsmittel beziehen. Dies gilt auch für alle folgenden Mengenangaben, sofern nicht ausdrücklich anders angegeben.In a preferred embodiment of the invention, an agent according to the invention has a water-soluble builder block. The use of the term "builder block" is intended to express that the agents contain no further builder substances than those which are water-soluble, ie all builder substances contained in the agent are combined in the "block" characterized in this way, the amounts at most being Substances are excluded, which may be present as impurities or stabilizing additives in small amounts in the other ingredients of the products commercially. The term "water-soluble" is to be understood as meaning that the builder block dissolves without leaving a residue at the concentration which results from the use amount of the agent containing it in the customary conditions. Preferably, at least 15 wt .-% and up to 55 wt .-%, in particular 25 wt .-% to 50 wt .-% of water-soluble builder block in the inventive compositions. This is preferably composed of the components

1. a) 5% by weight to 35% by weight of citric acid, alkali citrate and / or alkali metal carbonate, which may also be replaced at least proportionally by alkali metal bicarbonate,
2. b) up to 10% by weight of alkali silicate having a modulus in the range of 1.8 to 2.5,
3. c) up to 2% by weight of phosphonic acid and / or alkali phosphonate,
4. d) up to 50% by weight of alkali metal phosphate, and
5. e) up to 10% by weight of polymeric polycarboxylate,

wherein the quantities are based on the total detergent or cleaning agent. This also applies to all following quantities, unless expressly stated otherwise.

In a preferred embodiment of the composition according to the invention, the water-soluble builder block contains at least 2 of components b), c), d) and e) in amounts greater than 0% by weight.

With regard to component a), in a preferred embodiment of the composition according to the invention, 15% by weight to 25% by weight of alkali carbonate, which may at least partly be replaced by alkali metal hydrogencarbonate, and up to 5% by weight, in particular 0.5% by weight. % to 2.5% by weight of citric acid and / or alkali citrate. In an alternative embodiment of inventive compositions are as component a) 5 wt .-% to 25 wt .-%, in particular 5 wt .-% to 15 wt .-% citric acid and / or alkali citrate and up to 5 wt .-%, in particular 1 wt .-% to 5 wt .-% alkali carbonate, which may be at least partially replaced by alkali metal bicarbonate included. If both alkali carbonate and alkali bicarbonate are present, the Component a) alkali carbonate and alkali metal bicarbonate preferably in a weight ratio of 10: 1 to 1: 1.

With regard to component b), in a preferred embodiment of the composition according to the invention, 1% by weight to 5% by weight of alkali metal silicate with a modulus in the range from 1.8 to 2.5 are contained.

With regard to component c), in a preferred embodiment, agents according to the invention contain from 0.05% by weight to 1% by weight of phosphonic acid and / or alkali metal phosphonate. Phosphonic acids are also understood as meaning optionally substituted alkylphosphonic acids, which may also have a plurality of phosphonic acid groups (so-called polyphosphonic acids). They are preferably selected from the hydroxy and / or aminoalkylphosphonic acids and / or their alkali salts, for example dimethylaminomethane diphosphonic acid, 3-aminopropane-1-hydroxy-1,1-diphosphonic acid, 1-amino-1-phenylmethane diphosphonic acid, 1-hydroxyethane 1,1-diphosphonic acid, amino-tris (methylenephosphonic acid), N, N, N ', N'-ethylenediamine tetrakis (methylenephosphonic acid) and acylated derivatives of phosphorous acid, which can also be used in any mixtures.

With regard to component d), in a preferred embodiment of the composition according to the invention, 15% by weight to 35% by weight of alkali metal phosphate, in particular trisodium polyphosphate, are contained. Alkaliphosphat is the summary term for the alkali metal (especially sodium and potassium) salts of the various phosphoric acids, in which one can distinguish metaphosphoric acids (HPO ₃ ) _n and orthophosphoric H ₃ PO _{4 in} addition to high molecular weight representatives. The phosphates combine several advantages: they act as alkali carriers, prevent lime deposits on machine parts or lime incrustations in fabrics and also contribute to the cleaning performance. Sodium dihydrogen phosphate, NaH ₂ PO ₄ , exists as a dihydrate (density 1.91 gcm ^-3 , melting point 60 °) and as a monohydrate (density 2.04 gcm ^-3 ). Both salts are white powders which are very soluble in water and which lose their water of crystallization when heated and at 200 ° C into the weak acid diphosphate (disodium hydrogen diphosphate, Na ₂ H ₂ P ₂ O ₇ ), at higher temperature in sodium trimetaphosphate (Na ₃ P ₃ O ₉ ) and pass on Madrell's salt. NaH ₂ PO _{4 is} acidic; It arises when phosphoric acid is adjusted to a pH of 4.5 with sodium hydroxide solution and the mash is sprayed. Potassium dihydrogen phosphate (potassium phosphate primary or monobasic potassium, potassium biphosphate, KDP), KH ₂ PO ₄ , is a white salt of density 2.33 gcm ^-3 , has a melting point of 253 ° (decomposition to form (KPO ₃ ) _x , potassium polyphosphate) and is slightly soluble in water. Disodium hydrogen phosphate (secondary sodium phosphate), Na ₂ HPO ₄ , is a colorless, very slightly water-soluble crystalline salt. It exists anhydrous and with 2 moles (density 2.066 gcm ^-3 , water loss at 95 °), 7 moles (density 1.68 gcm ^-3 , melting point 48 ° with loss of 5 H ₂ O) and 12 moles of water (density 1, 52 gcm ^-3 , melting point 35 ° with loss of 5 H ₂ O), becomes anhydrous at 100 ° C. and, on vigorous heating, passes into the diphosphate Na ₄ P ₂ O ₇ . Disodium hydrogen phosphate is used by neutralization of phosphoric acid with soda solution made of phenolphthalein as an indicator. Dipotassium hydrogen phosphate (secondary or dibasic potassium phosphate), K ₂ HPO ₄ , is an amorphous, white salt that is readily soluble in water. Trisodium phosphate, tertiary sodium phosphate, Na ₃ PO ₄ , are colorless crystals which have a density of 1.62 gcm ^-3 as dodecahydrate and a melting point of 73-76 ° C (decomposition), as decahydrate (corresponding to 19-20% P ₂ O ₅ ) have a melting point of 100 ° C and in anhydrous form (corresponding to 39-40% P ₂ O ₅ ) have a density of 2.536 gcm ^-3 . Trisodium phosphate is readily soluble in water under alkaline reaction and is prepared by evaporating a solution of exactly 1 mole of disodium phosphate and 1 mole of NaOH. Tripotassium phosphate (tertiary or tribasic potassium phosphate), K ₃ PO ₄ , is a white, deliquescent, granular powder of density 2.56 gcm ^-3 , has a melting point of 1340 ° and is readily soluble in water with an alkaline reaction. It arises, for example, when heating Thomasschlacke with coal and potassium sulfate. Despite the higher price, the more soluble, therefore highly effective, potassium phosphates are often preferred over the corresponding sodium compounds in the detergent industry. Tetrasodium diphosphate (sodium pyrophosphate), Na ₄ P ₂ O ₇ , exists in anhydrous form (density 2.534 gcm ^-3 , melting point 988 °, also indicated 880 °) and as decahydrate (density 1.815-1.836 gcm ^-3 , melting point 94 ° with loss of water) , For substances are colorless, in water with alkaline reaction soluble crystals. Na ₄ P ₂ O ₇ is formed on heating of disodium phosphate to> 200 ° or by reacting phosphoric acid with soda in a stoichiometric ratio and dewatering the solution by spraying. The decahydrate complexes heavy metal salts and hardness agents and therefore reduces the hardness of the water. Potassium diphosphate (potassium pyrophosphate), K ₄ P ₂ O ₇ , exists in the form of the trihydrate and is a colorless, hygroscopic powder with a density of 2.33 gcm ^-3 , which is soluble in water, the pH being 1% Solution at 25 ° 10.4. Condensation of the NaH ₂ PO ₄ or the KH ₂ PO ₄ results in higher molecular weight sodium and potassium phosphates, in which one can distinguish cyclic representatives, the sodium or potassium metaphosphates and chain types, the sodium or potassium polyphosphates. In particular, for the latter are a variety of names in use: melting or annealing phosphates, Graham's salt, Kurrolsches and Madrell's salt. All higher sodium and potassium phosphates are collectively referred to as condensed phosphates. The technically important pentasodium triphosphate, Na ₅ P ₃ O ₁₀ (sodium tripolyphosphate), is an anhydrous or with 6 H ₂ O crystallizing, non-hygroscopic, white, water-soluble salt of the general formula NaO- [P (O) (ONa) -O] _n -Na with n = 3. In 100 g of water dissolve at room temperature about 17 g, at 60 ° about 20 g, at 100 ° around 32 g of the salt water-free salt; after two hours of heating the solution to 100 ° caused by hydrolysis about 8% orthophosphate and 15% diphosphate. In the preparation of pentasodium triphosphate, phosphoric acid is reacted with soda solution or sodium hydroxide solution in a stoichiometric ratio and the solution is dehydrated by spraying. Similar to Graham's salt and sodium diphosphate, pentasodium triphosphate dissolves many insoluble metal compounds (including lime soaps). Pentakaliumtriphosphat, K ₅ P ₃ O ₁₀ (potassium tripolyphosphate), for example, in the form of a 50 wt .-% solution (> 23% P ₂ O ₅ , 25% K ₂ O) in the trade. The potassium polyphosphates are found in the detergents and cleaners industry wide use. There are also sodium potassium tripolyphosphates which can also be used in the context of the present invention. These arise, for example, when hydrolyzed sodium trimetaphosphate with KOH:

(NaPO ₃ ) ₃ + 2 KOH → Na ₃ K ₂ P ₃ O ₁₀ + H ₂ O

These are just like sodium tripolyphosphate, potassium tripolyphosphate or mixtures of these two applicable; Mixtures of sodium tripolyphosphate and sodium potassium tripolyphosphate or mixtures of potassium tripolyphosphate and sodium potassium tripolyphosphate or mixtures of sodium tripolyphosphate and potassium tripolyphosphate and sodium potassium tripolyphosphate can also be used according to the invention.

With regard to component e), in a preferred embodiment, agents according to the invention contain from 1.5% by weight to 5% by weight of polymeric polycarboxylate, in particular selected from the polymerization or copolymerization products of acrylic acid, methacrylic acid and / or maleic acid. Among these, particularly preferred are the homopolymers of acrylic acid and, among these, those having an average molecular weight in the range from 5,000 D to 15,000 D (PA standard).

Enzymes which can be used in the compositions include those from the class of proteases, lipases, cutinases, amylases, pullulanases, mannanases, cellulases, hemicellulases, xylanases, oxidases and peroxidases and mixtures thereof, for example proteases such as BLAP®, Optimase®, Opticlean® , Maxacal®, Maxapem®, Alcalase®, Esperase®, Savinase®, Durazym® and / or Purafect® OxP, amylases such as Termamyl®, Amylase-LT®, Maxamyl®, Duramyl® and / or Purafect® OxAm, lipases such as Lipolase ®, Lipomax®, Lumafast® and / or Lipozym®, cellulases such as Celluzyme® and / or Carezyme®. Particularly suitable are from fungi or bacteria, such as Bacillus subtilis, Bacillus licheniformis, Streptomyces griseus, Humicola lanuginosa, Humicola insolens, Pseudomonas pseudoalcaligenes or Pseudomonas cepacia derived enzymatic agents. The optionally used enzymes may be adsorbed to carriers and / or embedded in encapsulants to protect against premature inactivation. They are preferably present in the detergents, cleaners and disinfectants according to the invention in amounts of up to 10% by weight, in particular from 0.2% by weight to 2% by weight, particular preference being given to stabilizing enzymes which are stabilized against oxidative degradation become.

In a preferred embodiment of the invention, the agent contains 5% by weight to 50% by weight, in particular 8-30% by weight of anionic and / or nonionic surfactant, up to 60% by weight, in particular 5-40% by weight. % Builder and 0.2% to 2% by weight of enzyme selected from the proteases, lipases, cutinases, amylases, pullulanases, mannanases, cellulases, oxidases and peroxidases, and mixtures thereof.

As in the compositions optionally contained peroxygen compounds which may be omitted in intended for use in the inventive method but preferably, in particular organic peracids or pers acid salts of organic acids, such as phthalimidopercaproic, perbenzoic acid or salts of diperdodecanedioic acid, hydrogen peroxide and under the washing conditions hydrogen peroxide donating inorganic Salts, such as perborate, percarbonate and / or persilicate, into consideration. Hydrogen peroxide can also be produced by means of an enzymatic system, ie an oxidase and its substrate. If solid peroxygen compounds are to be used, they can be used in the form of powders or granules, which can also be enveloped in a manner known in principle. Particular preference is given to using alkali metal percarbonate, alkali metal perborate monohydrate, alkali metal perborate tetrahydrate or hydrogen peroxide in the form of aqueous solutions which contain 3% by weight to 10% by weight of hydrogen peroxide. If desired, peroxygen compounds in amounts of up to 50% by weight, in particular from 5% by weight to 30% by weight, are present in detergents or cleaners according to the invention.

In addition, conventional bleach activators which form peroxycarboxylic acids or peroxoimidic acids under perhydrolysis conditions and / or customary bleach-activating transition metal complexes can be used. The optional, especially in amounts of 0.5 wt .-% to 6 wt .-%, present component of the bleach activators include the commonly used N- or O-acyl compounds, for example, polyacylated alkylenediamines, especially tetraacetylethylenediamine, acylated glycolurils, especially tetraacetylglycoluril, N-acylated hydantoins, hydrazides, triazoles, urazoles, diketopiperazines, sulfuryl amides and cyanurates, in addition to carboxylic anhydrides, in particular phthalic anhydride, carboxylic acid esters, especially sodium isononanoyl-phenolsulfonat, and acylated sugar derivatives, in particular pentaacetylglucose, and cationic nitrile derivatives such as trimethylammoniumacetonitrile salts. The bleach activators may have been coated or granulated in a known manner with coating substances to avoid interaction with the per compounds, with the aid of carboxymethylcellulose granulated tetraacetylethylenediamine having mean particle sizes of 0.01 mm to 0.8 mm, granulated 1.5- Diacetyl-2,4-dioxohexahydro-1,3,5-triazine, and / or formulated in particulate trialkylammonium acetonitrile is particularly preferred. Such bleach activators are preferably contained in detergents or cleaners in amounts of up to 8% by weight, in particular from 2% by weight to 6% by weight, based in each case on the total agent.

Among the organic solvents which can be used in the compositions according to the invention, especially if they are in liquid or pasty form, are alcohols having 1 to 4 C atoms, in particular methanol, ethanol, isopropanol and tert-butanol, diols having 2 to 4 C atoms , in particular ethylene glycol and propylene glycol, and mixtures thereof and the derivable from said classes of compound ethers. Such water-miscible solvents are in the inventive Detergents preferably not more than 30 wt .-%, in particular from 6 wt .-% to 20 wt .-%, present.

In order to establish a desired pH, which does not result from the mixture of the other components, the compositions according to the invention can contain system- and environmentally compatible acids, in particular citric acid, acetic acid, tartaric acid, malic acid, lactic acid, glycolic acid, succinic acid, glutaric acid and / or adipic acid. but also mineral acids, in particular sulfuric acid, or bases, in particular ammonium or alkali metal hydroxides. Such pH regulators are preferably not more than 20% by weight, in particular from 1.2% by weight to 17% by weight, in the compositions according to the invention.

Soil release polymers, often referred to as "soil release" agents or because of their ability to soil-repel the treated surface, for example, the fiber, are referred to as "soil repellents", for example, nonionic or cationic cellulose derivatives. The particularly polyester-active soil release polymers include copolyesters of dicarboxylic acids, for example adipic acid, phthalic acid or terephthalic acid, diols, for example ethylene glycol or propylene glycol, and polydiols, for example polyethylene glycol or polypropylene glycol. Preferred soil release polymers include those compounds which are formally accessible by esterification of two monomeric moieties, wherein the first monomer is a dicarboxylic acid HOOC-Ph-COOH and the second monomer is a diol HO- (CHR ¹¹ -) _a OH, also known as polymeric Diol H- (O- (CHR ¹¹ -) _a ) _b OH may be present. Therein, Ph is an o-, m- or p-phenylene radical which can carry 1 to 4 substituents selected from alkyl radicals having 1 to 22 C atoms, sulfonic acid groups, carboxyl groups and mixtures thereof, R ¹¹ denotes hydrogen, an alkyl radical having 1 to 22 C atoms and mixtures thereof, a is a number from 2 to 6 and b is a number from 1 to 300. Preferably, in the polyesters obtainable from these, both monomer diol units -O- (CHR ¹¹ -) _a O- and also polymeric diol units - ( O- (CHR ¹¹ -) _a ) _b O-. The molar ratio of monomer diol units to polymer diol units is preferably 100: 1 to 1: 100, in particular 10: 1 to 1:10. In the polymer diol units, the degree of polymerization b is preferably in the range of 4 to 200, especially 12 to 140. The molecular weight or the average molecular weight or the maximum molecular weight distribution of preferred soil release polyester is in the range of 250 to 100,000, especially 500 to 50,000 The acid underlying the radical Ph is preferably selected from terephthalic acid, isophthalic acid, phthalic acid, trimellitic acid, mellitic acid, the isomers of sulfophthalic acid, sulfoisophthalic acid and sulfoterephthalic acid and mixtures thereof. If their acid groups are not part of the ester bonds in the polymer, they are preferably in salt form, in particular as alkali or ammonium salt. Among these, the sodium and potassium salts are particularly preferable. If desired, instead of the monomer HOOC-Ph-COOH, small proportions, in particular not more than 10 mol%, based on the proportion of Ph with the meaning given above, of other acids, having at least two carboxyl groups to be included in the soil release-capable polyester. These include, for example, alkylene and alkenylene dicarboxylic acids such as malonic acid, succinic acid, fumaric acid, maleic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid. Examples of diol components are ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,2-decanediol, 1, 2-dodecanediol and neopentyl glycol. Particularly preferred among the polymeric diols is polyethylene glycol having an average molecular weight in the range of 1000 to 6000. If desired, these polyesters may also be endgruppenverschlossen, with alkyl groups having 1 to 22 carbon atoms and esters of monocarboxylic acids in question as end groups. Preferably, polymers of ethylene terephthalate and polyethylene terephthalate in which the polyethylene glycol units have molecular weights of 750 to 5,000 and the molar ratio of ethylene terephthalate to polyethylene terephthalate is 50:50 to 90:10 are used alone or in combination with cellulose derivatives.

Polyvinylpyrrolidones, polyvinylimidazoles, polymeric N-oxides such as poly (vinylpyridine-N-oxide) and copolymers of vinylpyrrolidone with vinylimidazole and optionally other monomers belong to the color transfer inhibitors which are suitable for use in laundry detergents according to the invention.

The inventive compositions for use in the textile laundry may contain anti-crease agents, since textile fabrics, in particular of rayon, wool, cotton and their mixtures, may tend to wrinkle, because the individual fibers are sensitive to bending, buckling, pressing and squeezing transverse to the fiber direction. These include, for example, synthetic products based on fatty acids, fatty acid esters, fatty acid amides, alkylol esters, -alkylolamides or fatty alcohols, which are usually reacted with ethylene oxide, or products based on lecithin or modified phosphoric acid ester.

Graying inhibitors have the task of keeping suspended from the hard surface and in particular from the textile fiber suspended dirt in the fleet. Water-soluble colloids of mostly organic nature are suitable for this purpose, for example starch, glue, gelatin, salts of ether carboxylic acids or ether sulfonic acids of starch or of cellulose or salts of acidic sulfuric acid esters of cellulose or starch. Also, water-soluble polyamides containing acidic groups are suitable for this purpose. Furthermore, other than the above-mentioned starch derivatives can be used, for example aldehyde starches. Preference is given to using cellulose ethers, such as carboxymethylcellulose (Na salt), methylcellulose, hydroxyalkylcellulose and mixed ethers, such as methylhydroxyethylcellulose, methylhydroxypropylcellulose, methylcarboxymethylcellulose and mixtures thereof, for example in amounts of from 0.1 to 5% by weight, based on the compositions.

The agents may contain optical brighteners, among these in particular derivatives of diaminostilbenedisulfonic acid or their alkali metal salts. Suitable salts are, for example, salts of 4,4'-bis (2-anilino-4-morpholino-1,3,5-triazinyl-6-amino) stilbene-2,2'-disulphonic acid or compounds of similar construction which, instead of the morpholino Group carry a diethanolamino group, a methylamino group, an anilino group or a 2-methoxyethylamino group. Further, brighteners of the substituted diphenylstyrene type may be present, for example, the alkali salts of 4,4'-bis (2-sulfostyryl) -diphenyl, 4,4'-bis (4-chloro-3-sulfostyryl) -diphenyl, or 4 - (4-chlorostyryl) -4 '- (2-sulfostyryl). Mixtures of the aforementioned optical brightener can be used.

In particular when used in automatic washing or cleaning processes, it may be advantageous to add conventional foam inhibitors to the compositions. As foam inhibitors are, for example, soaps of natural or synthetic origin, which have a high proportion of C ₁₈ -C ₂₄ fatty acids. Suitable non-surfactant foam inhibitors are, for example, organopolysiloxanes and mixtures thereof with microfine, optionally silanized silica and paraffins, waxes, microcrystalline waxes and mixtures thereof with silanated silicic acid or bis-fatty acid alkylenediamides. It is also advantageous to use mixtures of various foam inhibitors, for example those of silicones, paraffins or waxes. The foam inhibitors, in particular silicone- and / or paraffin-containing foam inhibitors, are preferably bound to a granular, water-soluble or dispersible carrier substance. In particular, mixtures of paraffins and bistearylethylenediamide are preferred.

In agents according to the invention it is also possible to use active substances for avoiding the tarnishing of silver objects, so-called silver corrosion inhibitors. Preferred silver corrosion inhibitors are organic disulfides, dihydric phenols, trihydric phenols, optionally alkyl- or aminoalkyl-substituted triazoles such as benzotriazole and cobalt, manganese, titanium, zirconium, hafnium, vanadium or cerium salts and / or complexes in which the Metals in one of the oxidation states II, III, IV, V or VI are present.

The preparation of solid compositions according to the invention presents no difficulties and can be carried out in a manner known in principle, for example by spray-drying or granulation. For the preparation of compositions according to the invention having an increased bulk density, in particular in the range from 650 g / l to 950 g / l, a process comprising an extrusion step is preferred. Detergents, cleaners or disinfectants in the form of aqueous or other conventional solvent-containing solutions are particularly advantageously prepared by simply mixing the ingredients, which can be added in bulk or as a solution in an automatic mixer. In a preferred embodiment of means for the particular machine cleaning of dishes, these are tablet-shaped.

Examples example 1

A solution of 5.14 g (30 mmol) of 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide was added under argon within 45 min to 7.22 g (37 mmol) of 6-bromohexanoic acid in 10 ml of dichloromethane added dropwise in 125 ml of dichloromethane. After 15 minutes of stirring, 8.87 g (43 mmol) of N, N'-dicyclohexylcarbodiimide and 0.45 g (3.7 mmol) of 4-dimethylaminopyridine were added. It was stirred for 16 h at room temperature. It was then filtered and the solution was concentrated. The resulting residue (15 g) was taken up in 100 ml of ethyl acetate, washed with 100 ml of 5% hydrochloric acid, then twice with 50 ml of ice-water, then twice with 50 ml of saturated sodium bicarbonate solution and finally with 50 ml of saturated sodium chloride solution.

Obtained was 8.38 g of 4 - [(6-bromohexanoyl) amino] -2,2,6,6-tetramethylpiperidin-1-yl-oxyl as crude product, which was dissolved in 150 ml of ethanol without further purification. Within 5 minutes, a solution of 3.14 g of sodium sulfite (25 mmol) in 50 ml of demineralized water was added dropwise. The mixture was then stirred at 70 ° C for 3 h. After cooling to room temperature, the reaction mixture was filtered, concentrated and 9.7 g of a crude product were isolated. This was purified by column chromatography (eluent dichloromethane / methanol 5: 1) to give 4.37 g of 4 - [(6-sulfohexanoyl) amino] -2,2,6,6-tetramethylpiperidin-1-yl-oxyl (T1) as yellow solid.

Example 2

A 2 millimolar aqueous solution of T1 prepared in Example 1, which also contained 0.1 mol / l Na ₂ SO ₄ , and into which were placed cotton substrates provided with standardized blueberry stain (A1) or standardized tea stain (A2) , was electrolyzed at 40 ° C and pH 5 to 6 with a potential difference of 1.35 V (Ag / AgCl) using a graphite working electrode and a graphite counterelectrode with anolyte and catholyte separated by a frit, the soiled cotton substrate was in the anode compartment and convection in the solution was assisted by use of a magnetic stirrer. The cotton substrates were then removed, rinsed with ultrapure water, pressed between laboratory paper for drying and their brightness (L * value) determined. In Table 1, the brightness values (+ E) thus obtained and, for comparison, those which resulted in otherwise identical procedure without applying a potential difference (-E) are listed. Performing the otherwise same experiments with the potential difference but without the TEMPO derivative did not show any difference to the values for -E. Table 1: Brightness values + e -E Soiling A1 75.35 74.01 Soiling A2 83.69 81.33

Claims (10)

1. A washing or cleaning agent, characterized in that it contains a mediator compound in the form of anionically substituted 1-hydroxy-2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine-N-oxide, or (2,2,6,6-tetramethylpiperidin-1-yl)oxyl.
2. The agent according to claim 1, characterized in that it contains 0.05 % by weight to 10 % by weight, in particular 0.1 % by weight to 5 % by weight of the mediator compound and/or is free of a bleaching agent and conventional bleach activator.
3. Use of bleaching-active species, generated electrolytically by a redox reaction from anionically substituted 1-hydroxy-2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine-N-oxide, or (2,2,6,6-tetramethylpiperidin-1-yl)oxyl, to boost the cleaning power of washing and cleaning agents in an aqueous, particularly surfactant-containing bath.
4. A method for washing textiles or for cleaning hard surfaces, in particular for the machine cleaning of dishware, with use of a bleaching-active species, generated electrolytically by a redox reaction from anionically substituted 1-hydroxy-2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine-N-oxide, or (2,2,6,6-tetramethylpiperidin-1-yl)oxyl.
5. The method according to claim 4, characterized in that the bath containing the mediator compound is electrolyzed continuously or once or repeatedly for specific time periods, in particular, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, or 60 minutes.
6. The method according to claim 4 or 5, characterized in that the electrolysis device, made in particular as an electrolysis cell, is formed as a separate device independent of a washing machine or dishwasher, and said device operates on its own power source.
7. The method according to claim 4, characterized in that the mediator compound, in particular when a usual bleach dispensing apparatus is used, passes through an electrolysis device before admission into the chamber of a washing machine, in particular flows in aqueous solution or as a slurry through an electrolysis cell.
8. The use according to claim 3 or the method according to one of claims 4 to 7, characterized in that the concentration of the mediator compound in the aqueous washing or cleaning bath is 0.05 mmol/L to 5 mmol/L, in particular 0.1 mmol/L to 2 mmol/L.
9. The use or method according to one of claims 3 to 8, characterized in that it is carried out at pH values in the range of pH 2 to pH 12, in particular of pH 4 to pH 11.
10. The agent, use, or method according to one of claims 1 to 9, characterized in that the anionic substituent is selected from the SO₃ ^- group, CO₂ ^- group, PO₃ ^2- group, and mixtures thereof, and/or that the anionic substituent is bound directly or via a linker to a C atom of the piperidinyl ring, the linker being selected from alkylene groups, aminoalkylene groups, oxyalkylene groups, aminocarbonylalkylene groups, oxycarbonylalkylene groups each having 1 to 25 C atoms, and mixtures thereof.