EP0961823A1

EP0961823A1 - Ph-controlled release of detergent components

Info

Publication number: EP0961823A1
Application number: EP98905366A
Authority: EP
Inventors: Thomas Gassenmeier; Jürgen MILLHOFF; Thomas Müller-Kirschbaum
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1997-02-07
Filing date: 1998-01-29
Publication date: 1999-12-08
Anticipated expiration: 2018-01-29
Also published as: DE19704634A1; ES2187004T3; US20010012826A1; JP2001510501A; US6225276B1; DE59806112D1; EP0961823B1; WO1998035009A1; US6407052B2; JP4130998B2; ATE226978T1

Abstract

The invention relates to a washing process for washing textile fabrics using a solid, detergent compound in particle form containing a coated alkalizing agent, a specially coated ingredient and an acidifier. After dissolution of the detergent, the pH of the detergent solution is below 8. As the washing process proceeds, pH rises to values above 8.5 through dissolution of the coated alkalizing agent, thus allowing for the release of the specially coated ingredient and time-delayed action of said ingredient.

Description

'pH controlled release of detergent components'

The invention relates to coated solid detergent ingredients and detergent compositions containing these coated ingredients. In particular, the invention relates to detergent compositions which release one or more of their ingredients to the wash liquor in a time-delayed and controlled manner, the release being controlled via the pH of the wash liquor.

The controlled release of individual detergent components at certain times in the washing process is advantageous from an economic and ecological point of view and is accordingly the subject of intensive research. While in principle each individual detergent component can be released at a certain point in time by suitable physical and / or chemical measures, this controlled release is of outstanding importance particularly in the context of the interplay of bleaching and enzymatic cleaning. Most publications are therefore concerned with solving the problem of separating bleaching and enzymatic cleaning from one another in time, since the aggressive bleaching agents inactivate or even destroy the enzymes. In principle, two ways are conceivable here: Delayed release of the bleach so that the enzymatic cleaning is completed before the bleaching agents are released in the wash liquor, or delayed release of the enzymes when the bleaching process is almost complete. Since the bleaching agents destroy excess enzyme and thus prevent it from remaining on the laundry (odor formation), the first method is usually chosen. Another advantage that results from the coating of the bleaching agent particles is the increased storage stability, since uncoated bleaching agents are hydrolyzed quickly, especially in moist air, and the detergent compositions thus lose their washing power. Numerous agents are available for coating the detergent ingredients. Depending on the agent, a wide variety of factors such as the temperature or the hydrolysis of the shell material can be used for the release. A melt coating, which only allows the casing to become permeable above a certain temperature, is difficult to achieve because of the low washing temperatures preferred today, since problems such as clumping occur at low softening temperatures. Envelope materials that hydrolyze through sheer moisture also have disadvantages with regard to the storage stability of the compositions. It is therefore necessary to look for a wrapping material which, on the one hand, is soluble in the washing liquor quickly and without impairing the washing process under certain conditions, but on the other hand is so stable that storage is possible without problems.

Detergent and bleach compositions containing a source of hydrogen peroxide and a peroxyacid bleach precursor (bleach activator) which provide an initial alkaline pH (pH 10-11) in the wash liquor and the delayed release of acid into the wash liquor to form one to achieve a reduced pH in the liquor are described in the prior art and published, for example, in European patent applications EP-A-0 290 081 (Unilever) and EP-A-0 396 287 (Clorox).

The delayed release of individual components in bleach-containing detergent compositions is mentioned in a number of patents. International patent applications WO95 / 28454 (Procter & Gamble) and the series from WO95 / 28464 to WO95 / 284469 (all Procter & Gamble) and WO95 / 28473 (Procter & Gamble) disclose detergent compositions containing bleach containing a hydrogen peroxide precursor and contain a peroxyacid precursor, the release of the peroxyacid taking place in a controlled manner so that 50% of the peroxyacid concentration (so-called T50 test) is reached between 180 and 480 seconds. The controlled delivery of the components is achieved by coating individual components, defined particle sizes, compacting and mechanical or manual addition. The respective coated ingredients vary in the individual applications: For example, in WO95 / 28464 the release of the peracid is compared to the release of a compound. plexing agent delayed, in WO95 / 28465 the delivery of peracid is delayed compared to the delivery of a builder and in WO95 / 28467 an enzyme is released before the delivery of peracid. WO95 / 28466 describes the delayed release of an enzyme compared to the release of a surfactant and WO95 / 28468 and WO95 / 28469 describe detergent compositions in which the release of an enzyme is delayed compared to the release of a complexing agent for heavy metal ions or against a water-soluble builder . The systematic controlled release of individual ingredients by controlling the pH is not described in any patent application in this series.

Likewise, the coating of bleaching agents or bleach activators is well known in the art. US Pat. No. 5,000,869 (Safe Aid Products) describes detergent compositions which contain a coated and pH-controlled released halogenated glycoluril compound. The bleaching agent is coated with a polymer that dissolves above pH 6, preferably between pH 7.2 and 11.

WO94 / 15010 (Procter & Gamble) discloses the coating of TAED with water-soluble acidic polymers, the coating being able to be applied in the form of a melt, by spraying or in the form of solutions and dispersions, and also describes the simultaneous use of percarbonate, which preferably also is coated. The acidic polymer has a solubility of at least 5 g / 1 at 20 ° C.

EP-A-0 651 053 (Procter & Gamble) describes detergent compositions which contain an alkali metal percarbonate coated with alkali metal sulfate and carbonate, a bleach activator and a delayed-release (coated) acidifying agent, so that the pH of the wash liquor (1% solution at 20 ° C) is initially 9.5 to 13, while after complete release of the acidifying agent it is 7 to 9.3. The time for the complete release of the acidifying agent is in the range from 30 seconds to 10 minutes. Only when the pH falls below a threshold is the coating of the percarbonate attacked and dissolved, so that the bleaching effect occurs. Coated bleaching agents which are only released in the wash liquor at an increasing pH are not described in the prior art.

The invention is based on the object of developing a system which enables the pH-controlled release of detergent constituents, in particular bleaching agents, and which allows the release to take place in an alkaline medium.

The invention accordingly relates to a washing process for washing textile fabrics using a solid, particulate detergent composition, the pH of the washing liquor being below 8 after dissolution of the detergent and as the washing process progresses to over 8.5 by dissolving a coated alkalizing agent increases, which enable the release of a specially coated ingredient and a delayed effect of this ingredient.

In a particular embodiment of the invention, a bleaching agent, preferably sodium percarbonate, is used as the alkalizing agent, while a bleach activator, preferably tetraacetylethylene diamine (TAED), is used as the specially coated ingredient.

The invention furthermore relates to a solid, particulate detergent composition comprising a) 1 to 40% by weight of a coated bleach, b) 0.5 to 15% by weight of a bleach activator, c) 0.1 to 40% by weight an acidifying agent, the bleaching agent being coated with a coating material which, regardless of the pH, slowly dissolves in water, the bleach activator is coated with a polymeric acid and the acidifying agent is used without a coating. As a result of the acidifying agent, the pH in the wash liquor is comparatively low when the detergent composition is added, ie it is below 8. Subsequently, the coating of the bleaching agent slowly dissolves and increasingly releases alkaline bleaching agent, as a result of which the pH value of the wash liquor increases . If the pH of the liquor exceeds a value of approx. 8.5, the coating of the bleach activator begins to dissolve and thereby release the bleach activator. With a time delay, the full bleaching effect begins in the wash liquor. The period until the bleaching action begins can be determined on the one hand by the amount of acidifying agent added, and on the other hand by the thickness and permeability of the coatings on the bleaching agent and the bleach activator. Depending on the recipe and washing conditions, periods of between one and twenty minutes are possible, during which, for example, enzymatic cleaning can take place without the majority of the bleaching agents being present. Due to the coating of both the bleach and the bleach activator, the detergent composition has excellent storage stability and shows no losses in bleaching activity even in moist air.

Sodium perborate tetrahydrate and sodium perborate monohydrate are particularly important as coated bleaching agents (component a) which supply H ₂ O ₂ in water. Further bleaching agents which can be used are, for example, sodium percarbonate, peroxypyrophosphates, citrate perhydrates and H ₂ O ₂ -producing peracid salts or peracids, such as perbenzoates, peroxophthalates, diperazelaic acid, phthaloiminoperacid or diperdodecanedioic acid. The content of the agents in the coated bleaching agents is 1 to 40% by weight and in particular 10 to 20% by weight, advantageously using perborate monohydrate or percarbonate.

Suitable coating materials for the coating of the bleaching agent particles are water-soluble substances which slowly dissolve in the washing liquor, ie do not lead to a sudden release of the coated bleaching agent and whose dissolving properties do not have a strong pH dependence. In addition, substances are preferred which in turn do not change the pH of the wash liquor when dissolved. Preferred enveloping materials are fatty alcohols, which can optionally be mixed with other coating materials. A mixture of fatty alcohols and aluminum stearate may be mentioned here as an example. Other coating materials which have already been used to coat bleach particles are summarized below: magnesium sulfate and sodium hexaphosphate (BE 857 017, Solvay Interox), dihydrogen phosphate or pyrophosphate (EP 024 201, Clorox), phosphonic acids (EP 295 384, Degussa ), Sodium metaborate and silicate (DE 28 10 379, Degussa), water glass and sodium polyphosphate (DE 27 12 138, Degussa), sodium sulfate, sodium carbonate and silicate (DE 26 22 610, Solvay Interox), or sodium bicarbonate (DE 24 17 572, Solvay Interox), borax and magnesium sulfate (DE 33 21 082, Kao), boric acid (DE 28 00 916 Solvay Interox), but also partly organic components such as fat derivatives, paraffins and waxes (EP 030 759, Solvay Interox, melting temperature of Compounds between 25 and 90 ° C), polyethylene glycols and fatty acid esters thereof with a molecular weight of 300 to 1,700 (DE 23 37 338, Solvay Interox), combinations with magnesium oxide (US 4 131 879, G retay AG and US 4 120 812 and 4 131 562, both FMC Corp.), vinyl chloride-ethylene copolymer emulsions (DE 24 02 393, Solvay Interox) or vinyl chloride-ethylene-methacrylate copolymer emulsions (DE 24 02 392, Solvay Interox).

The coating materials can be applied from the melt or from solutions or dispersions, the solvent or emulsifier being removed by evaporation. Application as a fine powder, for example by electrostatic techniques, is also possible, although this method leads to irregular and poorly adhering coatings. The coating materials can be applied to the bleaching agent particles in stirrers, mixers and granulators. However, it is preferred to apply the coating materials in a fluidized bed, it being possible for the particles to be sized at the same time. If the wrapping materials lead to sticky products under certain circumstances, it may make sense to apply finely divided substances to the coated bleaching agent particles ("powdering"). All fine-particle substances can be used as powdering agents, although other detergent components such as Builder substances can be used. Preferred additional powdering agents are zeolites, Silicates, polymeric polycarboxylates, carbonates, citrates, starch, etc. are used. Part of the acidifying agent can also be used for powdering.

Coated bleach activators (component b) which can be used are compounds which, under perhydrolysis conditions, give aliphatic peroxocarboxylic acids having preferably 1 to 10 carbon atoms, in particular 2 to 4 carbon atoms, and / or optionally substituted perbenzoic acid. Suitable substances are those which carry O- and / or N-acyl groups of the number of carbon atoms mentioned and / or optionally substituted benzoyl groups. Preferred are multiply acylated 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- Acylimides, in particular N-nonanoylsuccinimide (NOSI), acylated phenolsulfonates, in particular n-nonanoyl- or isononanoyloxybenzenesulfonate (n- or iso-NOBS), carboxylic acid anhydrides, in particular phthalic anhydride, acylated polyhydric alcohols, in particular triacetyloxy, 2,5-acetiacetyl, ethylene glycol 2,5-dihydrofuran and acetylated sorbitol and mannitol or their mixtures described in European patent application EP 0 525 239 (Ausimont SPA) (SORMAN), acylated sugar derivatives, in particular pentaacetyl glucose (PAG), pentaacetylfructose, tetraacetylxylose and octaacetyllactose and optionally acetylated as well N-alkylated glucamine and gluconolactone, and / or N-acylated lactams, for example N -Benzoylcaprolactam, which from the international patent applications WO 94/27970, WO 94/28102, WO 94/28103, WO 95/00626 (all Procter & Gamble), WO 95/14759 (Warwick) and WO 95/17498 (Procter & Gamble ) are known. The acyl lactams described in international patent application WO 95/14075 (Degussa) are also preferably used. The combinations of conventional bleach activators known from German patent application DE 44 43 177 (Henkel) can also be used. Coated bleach activators of this type are present in amounts of 0.5% by weight to 15% by weight, based on the total agent.

The bleach activator is coated with polymeric acids, which only dissolve at pH values above 8. At pH values below 8, the coated Bleach activator particles in aqueous solution are stirred for hours without going into solution. Examples of polymeric acids which are particularly suitable for coating are polyacrylates which are distinguished on the one hand by the required solubilities as a function of the pH and on the other hand by good processability. Other polymeric acids which can be used as coating materials are copolymers of an unsaturated polycarboxylic acid such as maleic acid, citraconic acid, itaconic acid and mesaconic acid with an unsaturated monocarboxylic acid such as acrylic acid or α-alkyl-substituted acrylic acids.

The bleach activators can in principle be coated in the same way as the bleaching agents. A method is preferred in which the polymeric acids are applied to the bleach activators via a dispersion.

The enveloping materials for both the bleaching agent and the bleach activator are used in such amounts that an optimal interaction of the individual components and thus an exactly controlled release is made possible. Depending on the period within which a release should not take place and depending on the size of the coated particles, the amount of coating material will be measured. Preferred embodiments use less than 20% by weight of coating material, based on the mass of the coated particles, in particular less than 10% by weight of coating materials are preferred.

The acidifying agent used as the third component is used in amounts of 0.1 to 40, preferably 1 to 25% by weight, based on the finished agent. All water-soluble substances which are suitable for lowering the pH of an aqueous solution below the value 8 can be used as the acidifying agent. In combination with the other components of the agents according to the invention, a starting pH value is achieved in this way, which is slowly increased as the washing process progresses (release of the bleaching agent), which finally leads to release at pH values in the wash liquor above 8.5 of the bleach activator and thus leads to the onset of the bleaching effect. Preferred acidifying agents are inorganic and organic acids, for example the solid mono-, oligo- and polycarboxylic acids such as citric, tartaric and succinic acid, polycarboxylic acids such as polyacrylic acid, but also acids such as malonic acid, adipic acid, maleic acid, fumaric acid, oxalic acid, boric acid or amidosulfonic acid and mixtures of the acids mentioned. Acidic salts, such as hydrogen sulfates or carbonates, can also be used as acidifying agents, although again only care must be taken to maintain the pH conditions. In order to obtain a wash liquor with a pH below 8 when the detergents according to the invention are dissolved as quickly as possible, the acidifying agents are to be selected such that they dissolve quickly and bring the pH to the desired values quickly. A coating which would cause a delay in dissolution is unsuitable for the acidifying agents in the context of the present invention.

From an application point of view, the requirement for the acidifying agent (s) is that they are not volatile. From this point of view, solid acidifying agents which combine a low tendency to sublimate and a high melting point with good water solubility are clearly preferred. Liquid or pasty acidifying agents can only be used in minor amounts below 5% by weight of the total composition, and when they are used, packaging measures have to be taken to ensure storage stability even in the presence of high air humidity. Liquid and volatile acids or those that cannot be handled in powdered detergents, such as hydrochloric acid, nitric acid or sulfuric acid, are of course forbidden. Of course, when choosing the acidifying agent (s), care must also be taken to ensure that the resulting washing liquor neither the textiles nor harms human skin.

In addition to the coated components and uncoated auxiliaries which enable pH-controlled release of the coated ingredients, the agents according to the invention contain further customary ingredients for detergents, in particular anionic and nonionic surfactants, builder substances and other auxiliaries such as soil repellents, foam inhibitors, salts of polyphosphonic acids, optical brighteners, enzymes, bilisators, small amounts of neutral filling salts as well as colorants and fragrances, opacifiers or pearlescent agents.

Anionic surfactants used are, for example, those of the sulfonate and sulfate type. Preferred surfactants of the sulfonate type are olefin sulfonates, ie mixtures of alkene and hydroxyalkane sulfonates and disulfonates, such as those obtained from C ₁₂ . ₁₈ -monoolefins with terminal or internal double bond by sulfonation with gaseous sulfur trioxide and subsequent alkaline or acidic hydrolysis of the sulfonation products. Also suitable are alkanesulfonates obtained from C _12.18 alkanes, for example by sulfochlorination or sulfoxidation with subsequent hydrolysis or neutralization. The esters of α-sulfofatty acids (ester sulfonates), for example the α-sulfonated methyl esters of hydrogenated coconut, palm kernel or tallow fatty acids, are also suitable.

Other suitable anionic surfactants are sulfonated fatty acid glycerol esters. Fatty acid glycerol esters are to be understood as meaning the mono-, di- and triesters and their mixtures as obtained in the production by esterification of a monoglycerol with 1 to 3 mol of fatty acid or in the transesterification of triglycerides with 0.3 to 2 mol of glycerol become. Preferred sulfonated fatty acid glycerol esters are the sulfonation products of saturated fatty acids having 6 to 22 carbon atoms, for example caproic acid, caprylic acid, capric acid, myristic acid, lauric acid, palmitic acid, stearic acid or behenic acid.

Suitable surfactants of the sulfate type are the sulfuric acid monoesters from primary alcohols of natural and synthetic origin. The alkali and, in particular, the sodium salts of the sulfuric acid semiesters of C ₁₂ are used as alk (en) yl sulfates. ₁₈ fatty alcohols, for example from coconut fatty alcohol, tallow fatty alcohol, lauryl, myristyl, cetyl or stearyl alcohol or C ₁₀ . ₂₀ -oxoalcohols and those half-esters of secondary alcohols of this chain length are preferred. Also preferred are alk (en) yl sulfates of the chain length mentioned which contain a synthetic, petrochemical-based straight-chain alkyl radical which have a degradation behavior similar to that of the adequate compounds based on fatty chemical raw materials. C ₁₆ are of washing technology interest. ₁₈ -alk (en) yl sulfates are particularly preferred. It can also be particularly advantageous, and particularly advantageous for machine washing agents, to use C ₁₆ -C ₁₈ -alk (en) yl sulfates in combination with lower melting anionic surfactants and in particular with those anionic surfactants which have a lower Krafft point and relatively low ones Washing temperatures of, for example, room temperature to 40 ° C. show a low tendency to crystallize. In a preferred embodiment of the invention, the compositions therefore contain mixtures of short-chain and long-chain fatty alkyl sulfates, preferably C ₁₂ . ₁₈ fatty alkyl sulfates or mixtures of C ₁₂ . ₁₄ fatty alkyl sulfates or C ₁₂ . ₁₈ fatty alkyl sulfates with C ₁₆ . _{] 8} fatty alkyl sulfates and especially C ₁₂ . ₁₆ fatty alkyl sulfates with C ₁₆ . ₁₈ fatty alkyl sulfates. In a further preferred embodiment of the invention, however, not only saturated alkyl sulfates but also unsaturated alkenyl sulfates with an alkenyl chain length of preferably C ₁₆ to C ₂₂ are used. Here, in particular mixtures of saturated, mostly preferably ₆ existing sulfonated fatty alcohols and unsaturated, consisting predominantly of _{C] 8} sulfonated fatty alcohols from _C], for example the (applicant's commercial product) derived from solid or liquid fatty alcohol mixtures of the type HD-Ocenol ^® those . Weight ratios of alkyl sulfates to alkenyl sulfates from 10: 1 to 1: 2 and in particular from about 5: 1 to 1: 1 are preferred. 2,3-Alkyl sulfates, which can be prepared, for example, by adding sulfuric acid to α-oletein, are also suitable.

The sulfuric acid monoesters of the straight-chain or branched C ₇ ethoxylated with 1 to 6 mol of ethylene oxide. ₂₁ alcohols, such as 2-methyl-branched C ₉ . _u -Alcohols with an average of 3.5 moles of ethylene oxide (EO) or C ₁₂ . ₁₈ fatty alcohols with 1 to 4 EO are suitable. Because of their high foaming behavior, they are used in cleaning agents only in relatively small amounts, for example in amounts of 1 to 5% by weight.

Other suitable anionic surfactants are also the salts of alkylsulfosuccinic acid, which are also referred to as sulfosuccinates or as sulfosuccinic acid esters and which are monoesters and / or diesters of sulfosuccinic acid with alcohols, preferably fatty alcohols and especially ethoxylated fatty alcohols. Preferred sulfosuccinates contain C ₈ _ ₁₈ fatty alcohol residues or mixtures thereof. Particularly preferred sulfosuccinates contain a fatty alcohol residue which is derived from ethoxylated fatty alcohols, which in themselves are nonionic surfactants (description see below). Again, sulfosuccinates whose fatty alcohol residues are derived from ethoxylated fatty alcohols with a narrow homolog distribution are particularly preferred. It is also possible to use alk (en) ylsuccinic acid with preferably 8 to 18 carbon atoms in the alk (en) yl chain or salts thereof.

Soaps are particularly suitable as further anionic surfactants. Saturated fatty acid soaps are suitable, 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. In particular, those soap mixtures are preferred which consist of 50 to 100% by weight of saturated C ₁₂ . ₂₄ fatty acid soaps and 0 to 50 wt .-% are composed of oleic acid soap.

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

In addition to anionic surfactants, nonionic, cationic, zwitterionic or amphoteric surfactants can also be used in the detergent compositions. Nonionic surfactants are particularly preferred.

The nonionic surfactants used are preferably alkoxylated, advantageously ethoxylated, in particular primary alcohols having preferably 8 to 18 carbon atoms and an average of 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 are usually present in oxo alcohol radicals. In particular, however, alcohol ethoxylates with linear residues from alcohols are native original Jump with 12 to 18 carbon atoms, for example from coconut, palm, tallow or oleyl alcohol, and an average of 2 to 8 EO per mole of alcohol preferred. The preferred ethoxylated alcohols include, for example, C _12th , ₄ -alcohols with 3 EO or 4 EO, C ₉ . _π alcohol with 7 EO, C ₁₃ . ₁₅ alcohols with 3 EO, 5 EO, 7 EO or 8 EO, C ₁₂ . ₁₈ alcohols with 3 EO, 5 EO or 7 EO and mixtures thereof, such as mixtures of C _12.14 alcohol with 3 EO and C _{12 lg} alcohol with 5 EO. The degrees of ethoxylation given represent statistical averages, which can be an integer or a fraction for a specific product. Preferred alcohol ethoxylates have a narrow homolog distribution (narrow ranks ethoxylates, NRE). In addition to these nonionic surfactants, fatty alcohols with more than 12 EO can also be used. Examples of this are tallow fatty alcohol with 14 EO, 25 EO, 30 EO or 40 EO.

In addition, alkyl glycosides of the general formula RO (G) _x can also be used as further nonionic surfactants, in which R denotes a primary straight-chain or methyl-branched, in particular methyl-branched aliphatic radical having 8 to 22, preferably 12 to 18, C atoms and G is the symbol which stands for a glycose unit with 5 or 6 carbon atoms, preferably for glucose. The degree of oligomerization x, which indicates the distribution of monoglycosides and oligoglycosides, is any number between 1 and 10; x is preferably 1.2 to 1.4.

Another class of preferably used nonionic surfactants, which are used either as the sole nonionic surfactant or in combination with other nonionic surfactants, are alkoxylated, preferably ethoxylated or ethoxylated and propoxylated, fatty acid alkyl esters, preferably with 1 to 4 carbon atoms in the alkyl chain, in particular fatty acid methyl ester, as described for example in Japanese patent application JP 58/217598 or which are preferably produced by the process described in international patent application WO-A-90/13533 (Henkel).

Also nonionic surfactants of the amine oxide type, for example N-cocoalkyl-N, N-dimethylamine oxide and N-tallow alkyl-N, N-dihydroxyethylamine oxide, and the fatty acid alkanol lamides can be suitable. The amount of these nonionic surfactants is preferably not more than that of the ethoxylated fatty alcohols, in particular not more than half of them.

Other suitable surfactants are polyhydroxy fatty acid amides of the formula (I),

R ¹

R-CO-N- [Z] (I)

in which RCO stands for an aliphatic acyl radical with 6 to 22 carbon atoms, R * for hydrogen, an alkyl or hydroxyalkyl radical with 1 to 4 carbon atoms and [Z] for a linear or branched polyhydroxyalkyl radical with 3 to 10 carbon atoms and 3 to 10 hydroxyl groups. The polyhydroxy fatty acid amides are known substances which can usually be obtained by reductive amination of a reducing sugar with ammonia, an alkylamine or an alkanolamine and subsequent acylation with a fatty acid, a fatty acid alkyl ester or a fatty acid chloride.

The group of polyhydroxy fatty acid amides also includes compounds of the formula (II)

R! -OR ²

R-CO-N- [Z] (II)

in which R represents a linear or branched alkyl or alkenyl radical having 7 to 12 carbon atoms, Rl represents a linear, branched or cyclic alkyl radical or an aryl radical

2 to 8 carbon atoms and R ^{2 represents} a linear, branched or cyclic alkyl radical or an aryl radical or an oxyalkyl radical having 1 to 8 carbon atoms, where C _M - Alkyl or phenyl radicals are preferred and [Z] stands for a linear polyhydroxyalkyl radical, the alkyl chain of which is substituted with at least two hydroxyl groups, or alkoxylated, preferably ethoxylated or propoxylated derivatives of this radical.

[Z] is preferably obtained by reductive amination of a reduced sugar, for example glucose, fructose, maltose, lactose, galactose, mannose or xylose. The N-alkoxy- or N-aryloxy-substituted compounds can then be converted, for example according to the teaching of international application WO-A-95/07331 (Procter & Gamble), into the desired polyhydroxy fatty acid amides by reaction with fatty acid methyl esters in the presence of an alkoxide as catalyst.

In addition to the surfactant components, the detergent granules can also contain builder substances and other detergent ingredients.

In addition to silicates, other builders and cobuilder substances can also be used as builders in the detergent compositions. These include in particular zeolites, citrates and polymeric polycarboxylates.

Suitable crystalline, layered sodium silicates have the general formula

NaMSi _x O _{2x + 1} -yH ₂ O, where M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20 and are preferred values for x 2, 3 or 4. Such crystalline layered silicates are described, for example, in European patent application EP-A-0 164 514. Preferred crystalline layered silicates of the formula given are those in which M represents sodium and x assumes the values 2 or 3. In particular, both β- and δ-sodium disilicate Na ₂ Si ₂ O ₅ yH ₂ O are preferred, with β-sodium disilicate being able to be obtained, for example, by the method described in international patent application WO-A-91/08171 (Henkel) .

Amorphous sodium silicates with a modulus Na ₂ O: SiO ₂ of 1: 2 to 1: 3.3, preferably from 1: 2 to 1: 2.8 and in particular from 1: 2 to 1: 2.6, can also be used release delay are and have secondary washing properties. The delay in dissolution compared to conventional amorphous sodium silicates can be caused in various ways, for example by surface treatment, compounding, compacting / compression or by overdrying. In the context of this invention, the term “amorphous” is also understood to mean “X-ray amorphous”. This means that the silicates in X-ray diffraction experiments do not provide sharp X-ray reflections as are typical for crystalline substances, but at most one or more maxima of the scattered X-rays which have a width of several degree units of the diffraction angle. However, it can very well lead to particularly good builder properties if the silicate particles deliver washed-out or even sharp diffraction maxima in electron diffraction experiments. This is to be interpreted as meaning that the products have microcrystalline areas of size 10 to a few hundred nm, values up to max. 50 nm and in particular up to max. 20 µm are preferred. Such so-called X-ray amorphous silicates, which also have a delay in dissolution compared to conventional water glasses, are described, for example, in German patent application DE-A-44 00 024 (Henkel). Compacted / compacted amorphous silicates, compounded amorphous silicates and over-dried X-ray amorphous silicates are particularly preferred.

The finely crystalline, synthetic and bound water-containing zeolite used is preferably zeolite A and / or P. As zeolite P, zeolite ^MAP® (commercial product from Crosfield) is particularly preferred. However, zeolite X and mixtures of A, X and / or P are also suitable. The zeolite can be used as a spray-dried powder or as an undried stabilized suspension which is still moist from its production. In the event that the zeolite is used as a suspension, it may contain minor additions of nonionic surfactants as stabilizers, for example 1 to 3% by weight, based on zeolite, of ethoxylated C ₁₂ -C ₁₈ fatty alcohols with 2 to 5 ethylene oxide groups , C ₁₂ -C, ₄ - fatty alcohols with 4 to 5 ethylene oxide groups or ethoxylated isotridecanols. Suitable zeolites have an average particle size of less than 10 μm (volume distribution; measurement method: Coulter Counter) and preferably contain 18 to 22% by weight, in particular 20 to 22% by weight, of bound water. It is of course also possible to use the generally known phosphates as builder substances, provided that such use should not be avoided for ecological reasons. The sodium salts of orthophosphates, pyrophosphates and in particular tripolyphosphates are particularly suitable. Their content is generally not more than 25% by weight, preferably not more than 20% by weight, in each case based on the finished composition. In some cases, it has been shown that tripolyphosphates in particular, even in small amounts up to a maximum of 10% by weight, based on the finished agent, in combination with other builder substances lead to a synergistic improvement in the secondary washing ability.

Other suitable organic builder substances are dextrins, for example oligomers or polymers of carbohydrates, which can be obtained by partial hydrolysis of starches. The hydrolysis can be carried out by customary processes, for example acid-catalyzed or enzyme-catalyzed. They are preferably hydrolysis products with average molecular weights in the range from 400 to 500,000. A polysaccharide with a dextrose equivalent (DE) in the range from 0.5 to 40, in particular from 2 to 30, is preferred, DE being a customary measure for is the reducing effect of a polysaccharide compared to dextrose, which has a DE of 100. Both maltodextrins with a DE between 3 and 20 and dry glucose syrups with a DE between 20 and 37 as well as so-called yellow dextrins and white dextrins with higher molar masses in the range from 2000 to 30000 can be used. A preferred dextrin is described in British patent application 94 19 091 (Cerestar) described. The oxidized derivatives of such dextrins are their reaction products with oxidizing agents which are capable of oxidizing at least one alcohol function of the saccharide ring to the carboxylic acid function. Such oxidized dextrins and processes for their preparation are known, for example, from European patent applications EP-A-0 232 202 (Roquette Freres), EP-A-0 427 349 (Natural Science Institute NL), EP-A-0 472 042 (Fertec Ferruzzi) and EP-A-0 542 496 (Procter & Gamble) and international patent applications WO-A-92/18542 (Novamont), WO-A-93/08251 (Henkel), WO-A-94/28030 (Henkel), WO -A- 95/07303 (Natural Science Institute NL), WO-A-95/12619 (Agricultural Institute NL) and WO-A-95/20608 (Henkel). A product oxidized at C _{6 of} the saccharide ring can be particularly advantageous.

Other suitable cobuilders are oxydisuccinates and other derivatives of disuccinates, preferably ethylenediamine disuccinate. Also particularly preferred in this context are glycerol disuccinates and glycerol trisuccinates, as described, for example, in US Pat. Nos. 4,524,009, 4,639,325 (both Staley), in European patent application EP-A-0 150 930 (Staley) and Japanese patent application JP 93/339896. Suitable amounts used in formulations containing zeolite and / or silicate are 3 to 15% by weight.

Other useful organic cobuilders are, for example, acetylated hydroxycarboxylic acids or their salts, which may also be in lactone form and which contain at least 4 carbon atoms and at least one hydroxyl group and a maximum of two acid groups. Such cobuilders are described, for example, in international patent application WO-A-95/20029 (Henkel).

In addition to the surfactants, bleaching agents and builders, a large number of compounds can be used in detergents, for example foam inhibitors, phosphonates, enzymes and optical brighteners.

When used in machine washing processes, it can be advantageous to add conventional foam inhibitors to the agents. Suitable foam inhibitors are, for example, soaps of natural or synthetic origin, which have a high proportion of C ₈ -C ₂₄ fatty acids. Suitable non-surfactant-like foam inhibitors are, for example, organopolysiloxanes and their mixtures with microfine, optionally silanized silica, and paraffins, waxes, microcrystalline waxes and their mixtures with silanized silica or bistearylethylenediamide. Mixtures of various foam inhibitors are also used with advantages, for example those made of silicones, paraffins or waxes. The foam inhibitors are preferably in particular silicone or paraffin-containing foam inhibitors, bound to a granular, water-soluble or dispersible carrier substance. Mixtures of paraffins and bistearylethylenediamides are particularly preferred.

The salts of polyphosphonic acids which are preferably used are the neutral sodium salts of, for example, l-hydroxyethane-l, l-diphosphonate, diethylenetriaminepentamethylenephosphonate or ethylenediaminetetramethylenephosphonate in amounts of 0.1 to 1.5% by weight.

Suitable enzymes are those from the class of proteases, lipases, amylases, cellulases or mixtures thereof. Enzymes obtained from bacterial strains or fungi such as Bacillus subtilis, Bacillus licheniformis and Streptomyces griseus are particularly suitable. Proteases of the subtilisin type and in particular proteases which are obtained from Bacillus lentus are preferably used. Enzyme mixtures, for example of protease and amylase or protease and lipase or protease and cellulase or of cellulase and lipase or of protease, amylase and lipase or protease, lipase and cellulase, but in particular mixtures containing cellulase, are of particular interest. Peroxidases or oxidases have also proven to be suitable in some cases. The enzymes can be adsorbed on carriers and / or embedded in coating substances in order to protect them against premature decomposition. The proportion of the enzymes, enzyme mixtures or enzyme granules can be, for example, about 0.1 to 5% by weight, preferably 0.1 to about 2% by weight.

The agents according to the invention can contain derivatives of diaminostilbenedisulfonic acid or their alkali metal salts as optical brighteners. Suitable are, for example, salts of 4,4'-bis (2-anilino-4-morpholino-l, 3,5-triazinyl-6-amino) stilbene-2,2'-disulfonic acid or compounds of similar structure which instead of the morpholino- Group carry a diethanolamino group, a methylamino group, anilino group or a 2-methoxyethylamino group. Brighteners of the substituted diphenylstyryl type may also be present, for example the alkali salts of 4,4'-bis (2-sulfostyryl) diphenyl, 4,4'-bis (4-chloro-3-sulfostyryl) - diphenyls, or 4- (4-chlorostyryl) -4 '- (2-sulfostyryl) diphenyls. Mixtures of the aforementioned brighteners can also be used.

The invention described above is not limited to the coating of bleaching agents and bleach activators. Rather, each detergent ingredient can be coated according to the invention and thus released in a pH-controlled manner. The parameters to be observed are generally the coating of the pH-controlled ingredient to be released with polymeric acids, the coating of an alkalizing agent with a water that is slowly soluble in water, which dissolves regardless of the pH of the wash liquor, and the use of an uncoated acidifying agent, which low starting pH in the wash liquor. By slowly dissolving the water-soluble shell, the wash liquor becomes increasingly alkaline when the alkalizing agent is released, until finally at pH values above 8.5 the shell begins to dissolve from the polymeric acids and the pH-controlled ingredient to be released to the wash liquor delivers. Variants are also conceivable, for example, in which acid bleaching takes place and then an agent is released which destroys the bleaching agents. A further delay can be achieved via the respective thickness of the coating, so that the time of release can be determined well.

B e i s p i e l e

Coating the bleach activator:

Crystalline tetraacetylethylenediamine (TAED) was mixed in a ratio of 5: 1 with a 32% polyacrylate dispersion, granulated and dried at 45 ° C. The granules obtained in this way are highly stable and can be stirred in a pH-neutral to weakly acidic surfactant solution for several hours without going into solution. In an alkaline solution (pH> 8.5), the granules disintegrate in 1 to 2 minutes.

Bleach coating:

Commercial sodium percarbonate was coated with 15% by weight of its weight in a mixture of fatty alcohols and aluminum stearate (2: 1). Here, the coating material was applied in the form of a melt which does not penetrate deep into the particles and thus forms a relatively homogeneous coating layer, so that the particles dissolve within a narrow period of time. In order to obtain easily pourable grains, the coated bleach particles were additionally powdered with rice starch.

Production of the detergent:

A bleach and enzyme-free detergent composition comprising surfactants, builders and auxiliaries (for composition, see Table 1) was mixed with the coated bleach particles, the coated bleach activator particles and with crystalline citric acid in the amounts given in Table 2.

Table 1: Ingredients of the detergent composition (wt .-%).

Soap 5.42

Sodium C ₁₂ . ₁₄ alkyl benzene sulfonate 22.67

Sodium C ₁₄ . ₁₆ -fatty alcohol sulfate 4.59

C ₁₂ . ₁₈ -Fatty alcohol-5 EO 0.81

Sodium carbonate 4.55 Zeolite A 29.86

Sodium silicate 8.00

Acrylic acid-maleic acid copolymer 16.16 opt. Brightener 0.45

Phosphonate 2.30

NaOH, 50% 0.63

Water 3.88 other salts 0.68

Table 2: Ingredients of the detergent composition according to the invention (% by weight)

Detergent composition 59.5% by weight of coated bleach (Na percarbonate) 23.3% by weight of coated bleach activator (TAED) 7% by weight

Citric acid monohydrate 10.2% by weight

The detergent obtained in this way was dissolved in water (30 ° C., 16 ° d, dosage: 6 g / 1) and the release of the TAED as peracetic acid was determined iodometrically. Immediately after the detergent dissolved, the pH value dropped to 6.5, and then rose to values above 8.5 within four minutes (pH = 9.2 after 5 min. Constant). The release of peracetic acid only started after 4 minutes, i.e. only at pH values of the wash liquor above 8.5.

Claims

Patent claims

1. Washing process for washing textile fabrics using a solid, particulate detergent composition, the pH of the wash liquor being below 8 after dissolution of the detergent and increasing as the washing process progresses by dissolving a coated alkalizing agent to values above 8.5, which is a Release of a specially coated ingredient and a delayed effect of this ingredient.

2. Washing method according to claim 1, characterized in that the coated alkalizing agent is a bleaching agent, preferably sodium percarbonate.

3. Washing method according to one of claims 1 to 2, characterized in that the specially coated ingredient is a bleach activator, preferably tetraacetylethylene diamine (TAED).

4. Solid, particulate detergent composition containing a) 1 to 40% by weight of a coated bleaching agent, b) 0.5 to 15% by weight of a bleach activator, c) 0.1 to 40% by weight of an acidifying agent, thereby characterized in that the bleaching agent is coated with a coating material which slowly dissolves in water regardless of the pH, the bleach activator is coated with a polymeric acid and the acidifying agent is used without a coating.

5. Detergent composition according to claim 4, characterized in that it contains fatty alcohols, preferably in a mixture with other coating materials, as the coating material for the bleaching agent.

6. Detergent composition according to one of claims 4 to 5, characterized in that it contains sodium percarbonate as a bleaching agent.

7. Detergent composition according to one of claims 4 to 6, characterized in that it contains tetraacetylethylene diamine (TAED) as a bleach activator.

8. Detergent composition according to one of claims 4 to 7, characterized in that it contains polycarboxylic acids as acidifying agents.