EP2265703B1 - Color-protecting detergent composition - Google Patents

Description

The present invention relates to the use of porous polyamide particles as color transfer inhibiting agents in the washing and / or cleaning of textiles.

Detergents and cleaners in addition to the indispensable for the washing and cleaning process ingredients such as surfactants and builders usually other ingredients that can be summarized under the term washing aids and include as different drug groups such as foam regulators, grayness inhibitors, bleach, bleach activators and enzymes. Such auxiliaries also include substances which are intended to prevent dyed textile fabrics from causing a changed color impression after washing. This color impression change washed, ie cleaner, textiles can be based on the one hand, that dye components are removed by the washing or cleaning process from the textile ("fading"), on the other hand may be deposited by differently colored textiles dyes on the textile ("discoloration" ). The discoloration aspect can also play a role in undyed laundry items when washed together with colored laundry items. In order to avoid these undesirable side effects of removing dirt from textiles by treatment with usually surfactant-containing aqueous systems, detergents, especially if they are provided as so-called color or colored laundry detergents for colored textiles, contain active ingredients which prevent the detachment of dyes from the textile or At least the deposition of detached, located in the wash liquor to avoid dyes on textiles. However, many of the commonly used - usually water-soluble - polymers have such a high affinity for dyes that they draw them more from the dyed fiber, so that it comes in their use to color loss. In addition, some conventional dye transfer inhibitors perform only with some classes of dyes and can not prevent the transfer of other dye classes.

Surprisingly, it has now been found that porous polyamide particles lead to unexpectedly high color transfer inhibition when used in detergents. Particularly pronounced is the prevention of dyeing of white or other colored fabrics by washed out of textiles dyes. It is conceivable that the polymer particles take up dye molecules detached from the dyed fabrics because of their large surface, which in particularly preferred cases may be dendritic or have a fractal geometry, do not release them again and prevent the deposition of the dyes on white or other-colored textiles.

• einen zahlenmittleren Partikeldurchmesser von 1 bis 30 µm,
• eine spezifische Oberfläche nach BET (gemäß DIN 66131) von 5 m²/g oder mehr,
• eine Ölabsorptionskapazität (boiled linseed oil) von 160 ml/100 g oder mehr,
• eine Kristallinität (DSC-Messung) von 40% oder größer, und
• einen Quotienten von volumenmittlerem Partikeldurchmesser zu zahlenmittlerem Partikeldurchmesser von 1,0 bis 1,5 aufweisen,

zur Vermeidung der Übertragung von Textilfarbstoffen von gefärbten Textilien auf ungefärbte oder andersfarbige Textilien bei deren gemeinsamer Wäsche in insbesondere tensidhaltigen wäßrigen Lösungen.The invention relates to the use of porous polyamide particles, which

• a number-average particle diameter of 1 to 30 μm,
• a BET specific surface area (according to DIN 66131) of 5 m ² / g or more,
• an oil absorption capacity (boiled linseed oil) of 160 ml / 100 g or more,
• a crystallinity (DSC measurement) of 40% or greater, and
• have a quotient of volume-average particle diameter to number-average particle diameter of 1.0 to 1.5,

to avoid the transfer of textile dyes of dyed textiles to undyed or differently colored textiles when they are washed together in particular surfactant-containing aqueous solutions.

The preparation of such porous polyamide particles can generally be accomplished by mixing a solution of polyamide in a suitable solvent with a liquid phase in which polyamides are insoluble. Usually, the liquid phase is water-based, whereby it can be achieved by suitable further solvents that when mixing the liquids first of all a clear solution is formed, from which the polyamide particles precipitate. In particular, mixing ratios of polyamide solution to liquid phase of from 1 to 999 to 300 to 700, preferably from 2 to 998 to 250 to 750, have proven useful in the production.

Polyamide solutions can be provided, for example, with the solvents o-cresol, m-cresol, p-cresol, chlorophenol, phenol or mixtures thereof. Formic acid has also proven itself.

The liquid phase in which polyamides are insoluble is preferably miscible with the aforementioned solvents and, moreover, water-miscible. Preferred liquid phases are aliphatic alcohols, aliphatic ketones and mixtures of these. Methanol, ethanol, n-propanol, isopropanol, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone and mixtures of these have proven particularly useful.

Preferably, mixtures of 10 to 98% by weight of aliphatic alcohols and / or ketones with 2 to 90% by weight of water can be used as the liquid phase from which the polyamide particles precipitate. For nucleation, the liquid phase may contain high molecular weight polyalkylene glycols, e.g. PEG or PPG, in amounts of, for example, 0.5 to 10 wt .-% (based on the liquid phase).

• werden aliphatische Alkohole und/oder Ketone und Wasser gleichzeitig aber getrennt voneinander zu einer Polyamidlösung gegeben oder
• wird eine zuvor bereitete Mischung aus aliphatischen Alkoholen und/oder Ketonen und Wasser zu einer Polyamidlösung gegeben oder
• werden aliphatische Alkohole und/oder Ketone zu einer Polyamidlösung gegeben, wonach Wasser hinzugefügt wird oder
• wird Wasser zu einer Polyamidlösung gegeben, wonach aliphatische Alkohole und/oder Ketone zugegeben werden oder
• wird eine Polyamidlösung zu einer zuvor bereiteten Mischung aus aliphatischen Alkoholen und/oder Ketonen und Wasser gegeben oder
• wird eine Polyamidlösung zu aliphatischen Alkoholen und/oder Ketonen und Wasser gegeben und anschließen Wasser hinzugefügt.

The order of mixing is not critical to the manufacturing process. In preferred method

• Aliphatic alcohols and / or ketones and water are simultaneously but separately added to a polyamide solution or
• a previously prepared mixture of aliphatic alcohols and / or ketones and water is added to a polyamide solution or
• Aliphatic alcohols and / or ketones are added to a polyamide solution, after which water is added or
• Water is added to a polyamide solution, after which aliphatic alcohols and / or ketones are added or
• a polyamide solution is added to a previously prepared mixture of aliphatic alcohols and / or ketones and water or
• Add a polyamide solution to aliphatic alcohols and / or ketones and water and then add water.

The formation of the porous polyamide particles by precipitation usually takes place in periods of 1 second to 2 hours and can be assisted by stirring. Preferably, the mixing of the liquids and formation of the particles takes place at temperatures of 5 to 70 ° C, more preferably at 15 to 60 ° C.

After the above period, the polyamide particles can be easily separated from the solvent mixture by decantation, filtration or centrifugation. This is preferably followed by washing with methanol and / or acetone and drying in vacuo.

Very particularly preferred processes for the preparation use a solution of polyamide 11 and / or polyamide 12 in phenol, which contains 0.1 to 50 wt .-% Polymaid (e) based on their weight. As the liquid phase in such preferred method, a mixture of ethanol (preferably 50 to 90 wt .-%, based on the liquid phase), ethylene glycol (preferably 1 to 10 wt .-%, based on the liquid phase) and glycerol (preferably 1 to 12% by weight, based on the liquid phase). The polyamide solution in phenol (preferably 30 to 70 wt .-%, based on the mixture), the liquid phase (preferably 40 to 65 wt .-%, based on the mixture) and polyethylene glycol and / or polypropylene glycol having molecular weights> 1000 daltons ( preferably 0.5 to 10 wt .-%, based on the mixture) are stirred together to form a mixture containing 0.05 to 20 wt .-% polyamide (e). This mixture, which ideally has a viscosity below 200 Pas, is stirred at 20 to 80 ° C, preferably at 25 to 65 ° C for 30 to 60 minutes.

The spherical porous polyamide particles produced by the processes described above, which are used in preferred embodiments of the invention, usually have number-average particle diameters of from 0.1 .mu.m to 100 .mu.m, preferably from 0.3 .mu.m to 50 .mu.m, in particular from 0.5 .mu.m to 25 μm. The ratio of volume-average particle diameter (Dv) to number-average particle diameter (Dn), which is also called particle size distribution index (PDI = Dv / Dn), is preferably in the range of 1.0 to 1.3.

The porous polyamide particles have a BET specific surface area (according to DIN 66131) of 5 m ² / g or more. Particularly preferred particles according to the invention have a specific surface area according to BET (according to DIN 66131) of 5 m ² / g to 80 m ² / g, preferably from 6 m ² / g to 60 m ² / g and in particular from 7.5 m ² / g to 50 m ² / g , Very particularly preferred embodiments of the invention are characterized in that the porous polyamide particles have a BET specific surface area (according to DIN 66131) of 6 m ² / g or more, preferably 7 m ² / g or more and in particular 8 m ² / g or more.

Preferred porous polyamide particles have a porosity index RI (RI = S / S0, where S0 is the specific surface area, based on the number average particle diameter and is represented by the formula S0 = 6 / (p × Dn)) in the ρ the density of the particles and Dn is the number average particle diameter, and where S is BET specific surface area) in the range of 3 to 100, more preferably in the range of 5 to 70.

The porous polyamide particles have an average pore diameter of 0.01 μm to 0.20 μm, particularly 0.02 μm to 0.1 μm, and a crystallinity (DSC measurement) of 40% or greater.

The standard enthalpy (or specific heat of fusion) of the porous polyamide particles is measured by DSC. In this case, the sample is heated under nitrogen atmosphere from room temperature (20 ° C) at a rate of increase of 5 ° C / min. The standard enthalpy is calculated from the area of the heat absorption peak between 120 ° C and 230 ° C. The crystallinity of the porous polyamide particles is the quotient of the measured specific heat of fusion and the standard enthalpy of crystalline polyamide, the latter for polyamide 12 being about 209 J / g.

With regard to the oil absorption capacity of the particles used in the agents according to the invention, agents according to the invention are preferred in which the porous polyamide particles have an oil absorption capacity (boiled linseed oil) of 160 ml / 100 g or more, preferably 170 ml / 100 g or more.

The production of porous polyamide particles is also disclosed, for example, in Japanese Patent Application 2002-80629. Preferably, the porous polyamide particles are spherical.

The porous polyamide particles can be added separately to the washing solution in the course of a manual or mechanical washing or cleaning process, are preferably brought into contact with the textile as part of a pretreatment agent in a step upstream of the actual washing process or are further preferably incorporated into the detergent as a constituent of a washing or cleaning agent Wash solution introduced. The porous polyamide particles also develop their positive effect when they are used in the final rinse, in which usually textile softening active ingredients are used. Their use in a laundry pre-treatment step is also possible, in which case the particulate polymer preferably remains on the textile to be subsequently washed or passes together with it into the wash liquor.

A color-protective washing, laundry pretreatment, laundry aftertreatment or cleaning agent contains a color transfer inhibitor in the form of porous polyamide particles as defined above in addition to conventional ingredients compatible with this component.

An agent preferably contains from 0.05% to 20%, more preferably from 0.1% to 5%, by weight of such porous polyamide particles.

The mentioned active ingredients contribute to both previously mentioned aspects of color constancy, that is to say they reduce both discoloration and fading, although the effect of preventing staining, especially when washing white textiles, is most pronounced. Another object of the invention is therefore the use of porous polyamide particles as defined above to avoid the change in the color impression of textiles in their washing in particular surfactant-containing aqueous solutions. By changing the color impression is by no means the difference between dirty and clean textile to understand, but the color difference between each clean textile before and after the washing process.

Another object of the invention is a process for washing dyed textiles in surfactant-containing aqueous solutions, which is characterized in that one uses a surfactant-containing aqueous solution containing above-defined porous polyamide particles. In such a method, it is possible to wash white or undyed textiles together with the dyed textile without the white or undyed textile being dyed.

If desired, an agent may, in addition to the abovementioned dye-transfer-inhibiting active ingredient, additionally comprise a known dye transfer inhibitor, then preferably in amounts of from 0.01% by weight to 5% by weight, in particular from 0.1% by weight to 1% by weight. which, in a preferred embodiment of the invention, is a polymer of vinylpyrrolidone, vinylimidazole, vinylpyridine-N-oxide or a copolymer thereof. Useful are both polyvinylpyrrolidones having molecular weights of from 15,000 to 50,000 and also polyvinylpyrrolidones having molecular weights of more than 1,000,000, in particular from 1,500,000 to 4,000,000, N-vinylimidazole / N-vinylpyrrolidone copolymers, polyvinyl oxazolidones, polyamine N-oxide Polymers, polyvinyl alcohols and copolymers based on acrylamidoalkenylsulfonic acids. However, it is also possible to use enzymatic systems comprising a peroxidase and hydrogen peroxide or a substance which produces hydrogen peroxide in water. The addition of a mediator compound for the peroxidase, for example an acetosyringone, a phenol derivative or a phenotiazine or phenoxazine, is preferred in this case, with the above-mentioned conventional polymeric color transfer inhibiting agents can additionally be used. Polyvinylpyrrolidone preferably has an average molecular weight in the range from 10,000 to for use in agents according to the invention 60,000, in particular in the range of 25,000 to 50,000. Among the copolymers, those of vinylpyrrolidone and vinylimidazole in a molar ratio of 5: 1 to 1: 1 having an average molecular weight in the range of 5,000 to 50,000, especially 10,000 to 20,000 are preferred.

The detergents, which may be solid or liquid and may be in the form of homogeneous solutions or suspensions, in particular in the form of pulverulent solids, may in principle contain, in addition to the porous polyamide particles used in accordance with the invention, all known ingredients customary in such compositions. The agents may, in particular, builders, surface-active surfactants, bleaches based on organic and / or inorganic peroxygen compounds, bleach activators, water-miscible organic solvents, enzymes, sequestering agents, electrolytes, pH regulators and other auxiliaries, such as optical brighteners, grayness inhibitors, foam regulators and colorants and fragrances contain. In this case, it is also possible to apply the porous polyamide particles to a water-insoluble cloth or to introduce them, optionally with other customary ingredients, into a particularly well-sealed bag of water-insoluble but water-permeable material and thus as an additive, if desired several times, in particular twice, 3 times or 4 time to use in the washing process. Alternatively to the last-mentioned embodiment, the porous polyamide particles or the agents containing them may be packed in portions in a water-soluble material, e.g. a polyvinyl alcohol film, are introduced into the washing process.

The agents may contain one or more surfactants, in particular anionic surfactants, nonionic surfactants and mixtures thereof, but also cationic, zwitterionic and amphoteric surfactants.

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.

The nonionic surfactants used are preferably alkoxylated, advantageously ethoxylated, in particular primary, alcohols having preferably 8 to 18 carbon atoms and on average 1 to 12 moles of ethylene oxide (EO) per mole of alcohol, in which the alcohol radical can be linear or preferably methyl-branched in the 2-position or may contain linear and methyl-branched radicals in the mixture, as they are usually present in Oxoalkoholresten. In particular, however, alcohol ethoxylates with linear radicals of alcohols of natural origin having 12 to 18 carbon atoms, for example of coconut, palm, tallow or oleyl alcohol, and on average 2 to 8 EO per mole of alcohol are preferred. The preferred ethoxylated alcohols include, for example, C ₁₂ -C ₁₄ -alcohols with 3 EO or 4 EO, C ₉ -C ₁₁ -alcohols with 7 EO, C ₁₃ -C ₁₅ -alcohols with 3 EO, 5 EO, 7 EO or 8 EO, C ₁₂ -C ₁₈ -alcohols with 3 EO, 5 EO or 7 EO and mixtures of these, such as mixtures of C ₁₂ -C ₁₄ -alcohol with 3 EO and C ₁₂ -C ₁₈ -alcohol with 7 EO. The degrees of ethoxylation given represent statistical means which, for a particular product, may be an integer or a fractional number. Preferred alcohol ethoxylates have a narrow homolog distribution (narrow range ethoxylates, NRE). In addition to these nonionic surfactants, fatty alcohols with more than 12 EO can also be used. Examples include (tallow) fatty alcohols with 14 EO, 16 EO, 20 EO, 25 EO, 30 EO or 40 EO. In particular, agents for use in mechanical processes usually extremely low-foam compounds are used. These include preferably C ₁₂ -C ₁₈ -alkylpolyethylenglykol-polypropylene glycol ethers with in each case at to 8 mol ethylene oxide and propylene oxide units in the molecule. One can also use other known low-foaming nonionic surfactants such as C ₁₂ -C ₁₈ alkyl polyethylene glycol polybutylene each having up to 8 moles of ethylene oxide and butylene oxide units in the molecule and end-capped Alkylpolyalkylenglykolmischether. Also particularly preferred are the hydroxyl-containing alkoxylated alcohols, as described in the European patent application EP 0 300 305 are described, so-called Hydroxymischether. The nonionic surfactants also include alkyl glycosides of the general formula RO (G) _x in which R is a primary straight-chain or methyl-branched, in particular 2-methyl-branched aliphatic radical having 8 to 22, preferably 12 to 18 carbon atoms and G represents a glycose unit having 5 or 6 C atoms, preferably glucose. The degree of oligomerization x, which indicates the distribution of monoglycosides and oligoglycosides, is an arbitrary number - which, as a variable to be determined analytically, may also assume fractional values - between 1 and 10; preferably x is 1.2 to 1.4. Also suitable are polyhydroxy fatty acid amides of the formula (I) in which R ^{1 is} CO for an aliphatic acyl radical having 6 to 22 carbon atoms, R ^{2 is} hydrogen, an alkyl or hydroxyalkyl radical having 1 to 4 carbon atoms and [Z] is a linear or branched polyhydroxyalkyl radical with 3 to 10 carbon atoms: and 3 to 10 hydroxyl groups:

in der R³ für einen linearen oder verzweigten Alkyl- oder Alkenylrest mit 7 bis 12 Kohlenstoffatomen, R⁴ für einen linearen, verzweigten oder cyclischen Alkylenrest oder einen Arylenrest mit 2 bis 8 Kohlenstoffatomen und R⁵ für einen linearen, verzweigten oder cyclischen Alkylrest oder einen Arylrest oder einen Oxy-Alkylrest mit 1 bis 8 Kohlenstoffatomen steht, wobei C₁-C₄-Alkyl- oder Phenylreste bevorzugt sind, und [Z] für einen linearen Polyhydroxyalkylrest, dessen Alkylkette mit mindestens zwei Hydroxylgruppen substituiert ist, oder alkoxylierte, vorzugsweise ethoxylierte oder propoxylierte Derivate dieses Restes steht. [Z] wird auch hier vorzugsweise durch reduktive Aminierung eines Zuckers wie Glucose, Fructose, Maltose, Lactose, Galactose, Mannose oder Xylose erhalten. Die N-Alkoxy- oder N-Aryloxy-substituierten Verbindungen können dann beispielsweise durch Umsetzung mit Fettsäuremethylestern in Gegenwart eines Alkoxids als Katalysator in die gewünschten Polyhydroxyfettsäureamide überführt werden. Eine weitere Klasse bevorzugt eingesetzter nichtionischer Tenside, die entweder als alleiniges nichtionisches Tensid oder in Kombination mit anderen nichtionischen Tensiden, insbesondere zusammen mit alkoxylierten Fettalkoholen und/oder Alkylglykosiden, eingesetzt werden, sind alkoxylierte, vorzugsweise ethoxylierte oder ethoxylierte und propoxylierte Fettsäurealkylester, vorzugsweise mit 1 bis 4 Kohlenstoffatomen in der Alkylkette, insbesondere Fettsäuremethylester. Auch nichtionische Tenside vom Typ der Aminoxide, beispielsweise N-Kokosalkyl-N,N-dimethylaminoxid und N-Talgalkyl-N,N-dihydroxyethylaminoxid, und der Fettsäurealkanolamide können geeignet sein. Die Menge dieser nichtionischen Tenside beträgt vorzugsweise nicht mehr als die der ethoxylierten Fettalkohole, insbesondere nicht mehr als die Hälfte davon. Als weitere Tenside kommen sogenannte Gemini-Tenside in Betracht. Hierunter werden im Allgemeinen solche Verbindungen verstanden, die zwei hydrophile Gruppen pro Molekül besitzen. Diese Gruppen sind in der Regel durch einen sogenannten "Spacer" voneinander getrennt. Dieser Spacer ist in der Regel eine Kohlenstoffkette, die lang genug sein sollte, dass die hydrophilen Gruppen einen ausreichenden Abstand haben, damit sie unabhängig voneinander agieren können. Derartige Tenside zeichnen sich im Allgemeinen durch eine ungewöhnlich geringe kritische Micellkonzentration und die Fähigkeit, die Oberflächenspannung des Wassers stark zu reduzieren, aus. In Ausnahmefällen werden unter dem Ausdruck Gemini-Tenside nicht nur derartig "dimere", sondern auch entsprechend "trimere" Tenside verstanden. Geeignete Gemini-Tenside sind beispielsweise sulfatierte Hydroxymischether oder Dimeralkohol-bis- und Trimeralkohol-tris-sulfate und -ethersulfate. Endgruppenverschlossene dimere und trimere Mischether zeichnen sich insbesondere durch ihre Bi- und Multifunktionalität aus. So besitzen die genannten endgruppenverschlossenen Tenside gute Netzeigenschaften und sind dabei schaumarm, so dass sie sich insbesondere für den Einsatz in maschinellen Wasch- oder Reinigungsverfahren eignen. Eingesetzt werden können aber auch Gemini-Polyhydroxyfettsäureamide oder Poly-Polyhydroxyfettsäureamide. Geeignet sind auch die Schwefelsäuremonoester der mit 1 bis 6 Mol Ethylenoxid ethoxylierten geradkettigen oder verzweigten C₇-C₂₁-Alkohole, wie 2-Methylverzweigte C₉-C₁₁-Alkohole mit im Durchschnitt 3,5 Mol Ethylenoxid (EO) oder C₁₂-C₁₈-Fettalkohole mit 1 bis 4 EO. Zu den bevorzugten Aniontensiden gehören auch die Salze der Alkylsulfobernsteinsäure, die auch als Sulfosuccinate oder als Sulfobernsteinsäureester bezeichnet werden, und die Monoester und/oder Diester der Sulfobernsteinsäure mit Alkoholen, vorzugsweise Fettalkoholen und insbesondere ethoxylierten Fettalkoholen darstellen. Bevorzugte Sulfosuccinate enthalten C₈- bis C₁₈-Fettalkoholreste oder Mischungen aus diesen. Insbesondere bevorzugte Sulfosuccinate enthalten einen Fettalkoholrest, der sich von ethoxylierten Fettalkoholen ableitet, die für sich betrachtet nichtionische Tenside darstellen. Dabei sind wiederum Sulfosuccinate, deren Fettalkohol-Reste sich von ethoxylierten Fettalkoholen mit eingeengter Homologenverteilung ableiten, besonders bevorzugt. Ebenso ist es auch möglich, Alk(en)ylbernsteinsäure mit vorzugsweise 8 bis 18 Kohlenstoffatomen in der Alk(en)ylkette oder deren Salze einzusetzen. Als weitere anionische Tenside kommen Fettsäure-Derivate von Aminosäuren, beispielsweise von N-Methyltaurin (Tauride) und/oder von N-Methylglycin (Sarkoside) in Betracht. Insbesondere bevorzugt sind dabei die Sarkoside beziehungsweise die Sarkosinate und hier vor allem Sarkosinate von höheren und gegebenenfalls einfach oder mehrfach ungesättigten Fettsäuren wie Oleylsarkosinat. Als weitere anionische Tenside kommen insbesondere Seifen in Betracht. Geeignet sind insbesondere gesättigte Fettsäureseifen, wie die Salze der Laurinsäure, Myristinsäure, Palmitinsäure, Stearinsäure, hydrierten Erucasäure und Behensäure sowie insbesondere aus natürlichen Fettsäuren, zum Beispiel Kokos-, Palmkern- oder Talgfettsäuren, abgeleitete Seifengemische. Zusammen mit diesen Seifen oder als Ersatzmittel für Seifen können auch die bekannten Alkenylbernsteinsäuresalze eingesetzt werden.The polyhydroxy fatty acid amides are preferably derived from reducing sugars having 5 or 6 carbon atoms, in particular from glucose. The group of polyhydroxy fatty acid amides also includes compounds of the formula (II)

in the R ^{3 is} a linear or branched alkyl or alkenyl radical having 7 to 12 carbon atoms, R ^{4 is} a linear, branched or cyclic alkylene radical or an arylene radical having 2 to 8 Carbon atoms and R ^{5 is} a linear, branched or cyclic alkyl radical or an aryl radical or an oxyalkyl radical having 1 to 8 carbon atoms, preference being given to C ₁ -C ₄ -alkyl or phenyl radicals, and [Z] is a linear polyhydroxyalkyl radical, whose alkyl chain is substituted with at least two hydroxyl groups, or alkoxylated, preferably ethoxylated or propoxylated derivatives of this group. [Z] is also obtained here preferably by reductive amination of a sugar such as glucose, fructose, maltose, lactose, galactose, mannose or xylose. The N-alkoxy- or N-aryloxy-substituted compounds can then be converted into the desired polyhydroxy fatty acid amides, for example by reaction with fatty acid methyl esters in the presence of an alkoxide as catalyst. Another class of preferred nonionic surfactants used either as the sole nonionic surfactant or in combination with other nonionic surfactants, in particular together with alkoxylated fatty alcohols and / or alkyl glycosides, are alkoxylated, preferably ethoxylated or ethoxylated and propoxylated fatty acid alkyl esters, preferably from 1 to 4 carbon atoms in the alkyl chain, especially fatty acid methyl ester. Nonionic surfactants of the amine oxide type, for example N-cocoalkyl-N, N-dimethylamine oxide and N-tallowalkyl-N, N-dihydroxyethylamine oxide, and the fatty acid alkanolamides may also be suitable. The amount of these nonionic surfactants is preferably not more than that of the ethoxylated fatty alcohols, especially not more than half thereof. Other suitable surfactants are so-called gemini surfactants. These are generally understood as meaning those compounds which have two hydrophilic groups per molecule. These groups are usually separated by a so-called "spacer". This spacer is typically a carbon chain that should be long enough for the hydrophilic groups to be spaced sufficiently apart for them to act independently of each other. Such surfactants are generally characterized by an unusually low critical micelle concentration and the ability to greatly reduce the surface tension of the water. In exceptional cases, the term gemini surfactants not only such "dimer", but also corresponding to "trimeric" surfactants understood. Suitable gemini surfactants are, for example, sulfated hydroxy mixed ethers or dimer alcohol bis and trimer alcohol tris sulfates and ether sulfates. End-capped dimeric and trimeric mixed ethers are characterized in particular by their bi- and multi-functionality. Thus, the end-capped surfactants mentioned have good wetting properties and are low foaming, so that they are particularly suitable for use in machine washing or cleaning processes. However, it is also possible to use gemini-polyhydroxy fatty acid amides or poly-polyhydroxy fatty acid amides. Also suitable are the sulfuric acid monoesters of straight-chain or branched C ₇ -C ₂₁ -alcohols ethoxylated with from 1 to 6 mol of ethylene oxide, such as 2-methyl-branched C ₉ -C ₁₁ -alcohols having on average 3.5 mol of ethylene oxide (EO) or C ₁₂ - C ₁₈ -fatty alcohols with 1 to 4 EO. The preferred anionic surfactants also include the salts of alkylsulfosuccinic acid, which are also referred to as sulfosuccinates or as sulfosuccinic acid esters, and the monoesters and / or diesters of sulfosuccinic acid with alcohols, preferably fatty alcohols and in particular ethoxylated fatty alcohols. Preferred sulfosuccinates contain C ₈ to C ₁₈ fatty alcohol residues or mixtures of these. Particularly preferred sulfosuccinates contain a fatty alcohol residue other than derived ethoxylated fatty alcohols, which are considered by themselves nonionic surfactants. Sulfosuccinates, whose fatty alcohol residues are derived from ethoxylated fatty alcohols with a narrow homolog distribution, are again particularly preferred. Likewise, it is also possible to use alk (en) ylsuccinic acid having preferably 8 to 18 carbon atoms in the alk (en) yl chain or salts thereof. Suitable further anionic surfactants are fatty acid derivatives of amino acids, for example N-methyltaurine (Tauride) and / or N-methylglycine (sarcosides). Particularly preferred are the sarcosides or the sarcosinates and here especially sarcosinates of higher and optionally monounsaturated or polyunsaturated fatty acids such as oleyl sarcosinate. As further anionic surfactants are particularly soaps into consideration. Particularly suitable are saturated fatty acid soaps, such as the salts of lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated erucic acid and behenic acid and, in particular, soap mixtures derived from natural fatty acids, for example coconut, palm kernel or tallow fatty acids. Together with these soaps or as a substitute for soaps, it is also possible to use the known alkenylsuccinic acid salts.

The anionic surfactants, including the soaps, may be in the form of their sodium, calcium or ammonium salts and as soluble salts of organic bases, such as mono-, di- or triethanolamine. The anionic surfactants are preferably present in the form of their sodium or potassium salts, in particular in the form of the sodium salts.

Surfactants are present in the detergents in proportions of preferably from 5% by weight to 50% by weight, in particular from 8% by weight to 30% by weight.

An agent 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 (methy) enphosphonic acid) and 1-hydroxyethane-1,1- diphosphonic acid, polymeric hydroxy compounds such as dextrin and also polymeric (poly) carboxylic acids, in particular the polycarboxylates obtainable by oxidation of polysaccharides or dextrins, 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 3,000 and 200,000, of the copolymers between 2,000 and 200,000, preferably 30,000 to 120,000, each based on the free acid. A particularly preferred acrylic acid-maleic acid copolymer has a molecular weight of from 30,000 to 100,000. Commercially available products are, for example, Sokalan® CP 5, CP 10 and PA 30 from BASF. Suitable, although less preferred compounds of this class are copolymers of acrylic acid or methacrylic acid with vinyl ethers, such as vinylmethyl ethers, vinyl esters, ethylene, propylene and styrene, in which the proportion of acid 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 and 200,000. Further preferred copolymers are those which preferably 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 pasty or liquid, in particular water-containing agents.

Suitable water-soluble inorganic builder materials are, in particular, alkali metal silicates, alkali metal carbonates and alkali metal phosphates, which may be in the form of their alkaline, neutral or acidic sodium or potassium salts. Examples of these are trisodium phosphate, tetrasodium diphosphate, disodium dihydrogen diphosphate, pentasodium triphosphate, so-called sodium hexametaphosphate, oligomeric trisodium phosphate with degrees of oligomerization of from 5 to 1000, in particular from 5 to 50, and the corresponding potassium salts or mixtures of sodium and potassium salts. 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 particularly suitable as water-insoluble, water-dispersible inorganic builder materials. used. Among these, preferred are the detergent grade crystalline sodium aluminosilicates, particularly zeolite A, P and optionally X, alone or in mixtures, for example in the form of a cocrystal of zeolites A and X (Vegobond® AX, a commercial product of Condea Augusta SpA) , 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 22, especially 1.9 to 4, and y is a number from 0 to 33 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. Crystalline layer-form silicates of formula (I) given above are sold by Clariant GmbH under the trade name Na-SKS, eg Na-SKS-1 (Na ₂ Si ₂₂ O ₄₅ .xH ₂ O, Kenyaite), Na-SKS 2 (Na ₂ S ₁₄ O _{29˙xH 2} O, magadiite), Na-SKS-3 (Na ₂ Si ₈ O ₁₇ .xH ₂ O) or Na-SKS-4 (Na ₂ Si ₄ O ₉ .xH ₂ O , Makatit). Of these, especially Na-SKS-5 (α-Na ₂ Si ₂ O ₅ ), Na-SKS-7 (β-Na ₂ Si ₂ O ₅ , Natrosilit), Na-SKS-9 (NaHSi ₂ O ₅ · 3H ₂ O), Na-SKS-10 (NaHSi ₂ O ₅ · 3H ₂ O, kanemite), Na-SKS-11 (t-Na ₂ Si ₂ O ₅₎ and Na-SKS-13 (NaHSi ₂ O ₅ ), but especially Na-SKS-6 (δ-Na ₂ Si ₂ O ₅ ). In a preferred embodiment of the composition according to the invention, a granular compound of crystalline phyllosilicate and citrate, of crystalline phyllosilicate and of the above-mentioned (co-) polymeric polycarboxylic acid, or of alkali silicate and alkali metal carbonate, such as, for example, commercially available under the name Nabion® 15, is used ,

Builder substances are preferably present in the compositions in amounts of up to 75% by weight, in particular 5% by weight to 50% by weight.

Suitable peroxygen compounds for use in the compositions are in particular organic peracids or persalts of organic acids, such as phthalimidopercaproic acid, perbenzoic acid or salts of diperdodecanedioic acid, hydrogen peroxide and hydrogen peroxide under the washing conditions inorganic salts, which include perborate, percarbonate, persilicate and / or persulfate Caroat belong into consideration. If solid peroxygen compounds are to be used, they can be used in the form of powders or granules, which can also be coated in a manner known in principle. If an agent according to the invention contains peroxygen compounds, they are present in amounts of preferably up to 50% by weight, in particular from 5% by weight to 30% by weight. The addition of small amounts known Bleach stabilizers such as phosphonates, borates or metaborates and metasilicates and magnesium salts such as magnesium sulfate may be useful.

As bleach activators, it is possible to use compounds which, under perhydrolysis conditions, give aliphatic peroxycarboxylic acids having preferably 1 to 10 C atoms, in particular 2 to 4 C atoms, and / or optionally substituted perbenzoic acid. Suitable substances are those which carry O- and / or N-acyl groups of the stated C atom number and / or optionally substituted benzoyl groups. Preference is given to polyacylated alkylenediamines, in particular tetraacetylethylenediamine (TAED), acylated triazine derivatives, in particular 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT), acylated glycolurils, in particular tetraacetylglycoluril (TAGU), N -Acylimide, in particular N-nonanoylsuccinimide (NOSI), acylated phenolsulfonates, in particular n-nonanoyl or Isononanoyloxybenzolsulfonat (n- or iso-NOBS), carboxylic anhydrides, especially phthalic anhydride, acylated polyhydric alcohols, especially triacetin, ethylene glycol diacetate, 2,5-diacetoxy 2,5-dihydrofuran and enol esters, and also acetylated sorbitol and mannitol or mixtures thereof (SORMAN), acylated sugar derivatives, in particular pentaacetylglucose (PAG), pentaacetyl fructose, tetraacetylxylose and octaacetyl lactose and acetylated, optionally N-alkylated glucamine and gluconolactone, and / or N -acylated lactams, for example N-benzoyl-caprolactam. The hydrophilic substituted acyl acetals and the acyl lactams are also preferably used. Combinations of conventional bleach activators can also be used. Such bleach activators can, in particular in the presence of the abovementioned hydrogen peroxide-supplying bleach, in the usual amount range, preferably in amounts of 0.5 wt .-% to 10 wt .-%, in particular 1 wt .-% to 8 wt .-%, based on the total agent However, when using percarboxylic acid as the sole bleaching agent, it is preferable that it be completely contained.

In addition to the conventional bleach activators or in their place, sulfone imines and / or bleach-enhancing transition metal salts or transition metal complexes may also be present as so-called bleach catalysts.

Suitable enzymes which can be used in the compositions are those from the class of amylases, proteases, lipases, cutinases, pullulanases, hemicellulases, cellulases, oxidases, laccases and peroxidases and mixtures thereof. Particularly suitable are from fungi or bacteria, such as Bacillus subtilis, Bacillus licheniformis, Bacillus lentus, Streptomyces griseus, Humicola lanuginosa, Humicola insolens, Pseudomonas pseudoalcaligenes, Pseudomonas cepacia or Coprinus cinereus derived enzymatic agents. The enzymes may be adsorbed to carriers and / or embedded in encapsulants to protect against premature inactivation. They are preferably present in the detergents or cleaners according to the invention in amounts of up to 5% by weight, in particular from 0.2% by weight to 4% by weight. If the agent of the invention contains protease, it preferably has a proteolytic activity in the range of about 100 PE / g to about 10,000 PE / g, in particular 300 PE / g to 8000 PE / g. If several enzymes are to be used in the agent can this can be carried out by incorporation of the two or more separate or in a known manner separately prepared enzymes or by two or more together in a granule ready-made enzymes.

Among the agents, especially when they are in liquid or paste form, organic solvents which can be used in addition to water, include alcohols having 1 to 4 carbon atoms, in particular methanol, ethanol, isopropanol and tert-butanol, diols having 2 to 4 carbon 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 preferably present in the compositions according to the invention in amounts of not more than 30% by weight, in particular from 6% by weight to 20% by weight.

To establish a desired, by the mixture of the other components not automatically resulting pH value, the compositions of the invention system and environmentally acceptable 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 present in the compositions according to the invention in amounts of preferably not more than 20% by weight, in particular from 1.2% by weight to 17% by weight.

Graying inhibitors have the task of keeping suspended from the textile fiber dirt suspended 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 textile detergents may contain, for example, derivatives of diaminostilbenedisulfonic acid or their alkali metal salts as optical brighteners, although they are preferably free of optical brighteners for use as color detergents. 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. Furthermore, brighteners of the type of substituted diphenylstyrene may be present, for example the alkali metal salts of 4,4'-bis (2-sulfostinyl) -diphenyls, 4,4'-bis (4-chloro-3-sulfostyryl) -diphenyls, or 4- (4-chlorostyryl) -4 '- (2-sulfostyryl) - biphenyl. Mixtures of the aforementioned optical brightener can be used.

In particular, when used in mechanical 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 order to improve the aesthetic impression of the agents, they can be dyed with suitable dyes. Preferred dyes, the selection of which presents no difficulty to the skilled person, have a high storage stability and insensitivity to the other ingredients of the agents and to light and, in the case of use in laundry detergents, no pronounced substantivity to textile fibers, so as not to stain them.

The preparation of solid agents presents no difficulties and may be accomplished in a known manner, for example by spray-drying or granulation, with enzymes and any other thermally-sensitive ingredients, such as bleach, optionally added separately later. For the preparation of inventive compositions 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.

For the preparation of compositions in tablet form, which may be monophasic or multiphase, monochromatic or multicolor and in particular consist of one or more layers, in particular two layers, the procedure is preferably such that all components - optionally one layer at a time - in a mixer mixed together and the mixture by means of conventional tablet presses, such as eccentric or rotary presses, pressed with compressive forces in the range of about 50 to 100 kN, preferably at 60 to 70 kN. Particularly in the case of multilayer tablets, it may be advantageous if at least one layer is pre-compressed. This is preferably carried out at pressing forces between 5 and 20 kN, in particular at 10 to 15 kN. This gives fracture-resistant, yet sufficiently rapidly soluble tablets under application conditions with fracture and flexural strengths of normally 100 to 200 N, but preferably above 150 N. Preferably, a tablet produced in this way has a weight of 10 g to 50 g, in particular 15 g up to 40 g. The spatial form of the tablets is arbitrary and can be round, oval or be angular, with intermediate forms are possible. Corners and edges are advantageously rounded. Round tablets preferably have a diameter of 30 mm to 40 mm. In particular, the size of rectangular or cuboid-shaped tablets, which are predominantly introduced via the metering device, for example, the dishwasher, is dependent on the geometry and the volume of this metering device. Exemplary preferred embodiments have a base area of (20 to 30 mm) x (34 to 40 mm), in particular of 26x36 mm or 24x38 mm.

Liquid or pasty compositions in the form of conventional solvents, in particular water, containing solutions are usually prepared by simply mixing the ingredients that can be added in bulk or as a solution in an automatic mixer.

Examples

To determine the ink transfer-inhibiting properties of the individual detergents, a staining scale rating (SSR), which is based on ISO 105-A04, was carried out. Two white fabrics (A: 6 × 16 cm standard cotton fabric wfk, B: 6 × 16 cm standard polyamide fabric) were mixed with a colorant (1: Acid Blue 113, 2: Disperse Red 60, 3: Disperse Blue 79) whose concentration was 3 g / l (Farbgeber 1) and 10 g / l (colorants 2 and 3) in the wash liquor, using a color transfer inhibitor-free detergent composition (dosage 5.0 g / l) and adding (I.) 1 g / l or (II.) 10 g / l porous polyamide particles in a Linitest device at 60 ° C, then rinsed with water and dried hanging at room temperature. Subsequently, the degree of discoloration of the two tissues was determined spectrophotometrically. In addition, for comparison, the color transfer inhibitor-free detergent composition W was tested in the same manner without the addition of polyamide particles.

The degree of discoloration was then given in values from 1 (strong discoloration) to 5 (no discoloration).

It is clear from the SSR shown in the tables below that the compositions according to the invention have better dye transfer-inhibiting properties than the formulation without the dye transfer inhibiting active ingredient: Fabric: cotton inking W W + I W + II 1 4.5 4.7 4.9 2 4.8 nb 4.9 3 4.0 4.1 4.7 inking W W + I W + II 1 1.9 2.7 4.5 2 3.4 3.7 4.4 3 2.6 2.7 3.9

Claims (8)

1. Use of porous polyamide particles which have

   - a number-average particle diameter of 1 to 30 µm,

   - a BET specific surface area (to DIN 66131) of 5 m²/g or more,

   - an oil absorption capacity (boiled linseed oil) of 160 ml/100 g or more,

   - a crystallinity (DSC measurement) of 40% or above, and

   - a quotient of volume-average particle diameter to number-average particle diameter of 1.0 to 1.5,

   in order to avoid the transfer of textile dyes from dyed textiles onto undyed or differently coloured textiles when they are jointly washed in in particular surfactant-containing aqueous solutions.
2. Use of porous polyamide particles which have

   - a number-average particle diameter of 1 to 30 µm,

   - a BET specific surface area (to DIN 66131) of 5 m²/g or more,

   - an oil absorption capacity (boiled linseed oil) of 160 ml/100 g or more,

   - a crystallinity (DSC measurement) of 40% or above, and

   - a quotient of volume-average particle diameter to number-average particle diameter of 1.0 to 1.5,

   in order to avoid modifying the colour appearance of textiles when they are washed in in particular surfactant-containing aqueous solutions.
3. A method for washing dyed textiles in surfactant-containing aqueous solutions, characterised in that a surfactant-containing aqueous solution is used which contains porous polyamide particles which have

   - a number-average particle diameter of 1 to 30 µm,

   - a BET specific surface area (to DIN 66131) of 5 m²/g or more,

   - an oil absorption capacity (boiled linseed oil) of 160 ml/100 g or more,

   - a crystallinity (DSC measurement) of 40% or above, and

   - a quotient of volume-average particle diameter to number-average particle diameter of 1.0 to 1.5.
4. Use or a method according to any one of the preceding claims, characterised in that the spherical porous polyamide particles have number-average particle diameters of 0.1 µm to 100 µm, preferably of 0.3 µm to 50 µm, in particular of 0.5 µm to 25 µm.
5. Use or a method according to any one of the preceding claims, characterised in that the ratio of volume-average particle diameter (Dv) to number-average particle diameter (Dn), which is also designated the particle size distribution index (PDI=Dv/Dn), of the porous polyamide particles is in the range from 1.0 to 1.3.
6. Use or a method according to any one of the preceding claims, characterised in that the porous polyamide particles have a BET specific surface area (to DIN 66131) of 5 m²/g to 80 m²/g, preferably of 6 m²/g to 60 m²/g and in particular of 7.5 m²/g to 50 m²/g.
7. Use or a method according to any one of the preceding claims, characterised in that the porous polyamide particles have a porosity index RI in the range from 3 to 100, in particular in the range from 5 to 70.
8. Use or a method according to any one of the preceding claims, characterised in that the porous polyamide particles have an average pore diameter of 0.01 µm to 0.20 µm, in particular of 0.02 µm to 0.1 µm, and a crystallinity (DSC measurement) of 40% or above.