EP0574436B1 - Detergents - Google Patents

Abstract

Detergents which contain 30 to 65 wt. % of a fine-particle, hydrated zeolite with a mean particle size of 1 to 5 $g(m)m and 1 to 15 wt. % of a solid alkali silicate with a molar composition M2?O:SiO2? of 1:2.0 to 1:3.0 and are free from water-soluble organic complex builders from the group of the substituted phosphonates, free from polymeric polycarboxylates and substantially free from alkali carbonates can be used as substitutes for ordinary commercial detergents which contain large amounts of phosphonates, polymeric polycarboxylates and/or alkali carbonates, without any loss of detergency. The proportion of organic synthetic compounds in detergents can thus be reduced.

Description

The invention relates to a phosphate-free detergent based on zeolite and alkali silicate and a process for its production.

In practice, zeolite, in particular zeolite NaA, and in particular mixtures of zeolite with alkali silicates and alkali carbonates and polymeric polycarboxylates have been used as phosphate substitutes in washing and cleaning agents and to reduce incrustations. There are also complexing agents such as the salts of nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA) and phosphonic acids. The mostly selectively acting complexing agents have the task of eliminating heavy metal ions, which, even in traces, can have a very negative effect on the washing process, in particular on the bleaching process (Ullmann, 1987, Vol. 8, pp. 351 to 354). It is known that the phosphonates also counteract the precipitation of poorly soluble calcium salts and thus the incrustation caused by poorly soluble calcium salts and the graying of the fabric ("Use of phosphonates in heavy duty liquid detergents", M. Paladini, G. Schnorbus, soap oil fats - Waxes, 115th year (1989), pp. 508 to 511). Finally, the combined use of phosphonates and copolymers based on acrylic acid and maleic acid results in a higher degree of whiteness of the textiles compared to formulations containing only one of these two components ("Use of phosphonates in household detergents with a low phosphorus content (1%)", Paladini, G. Schnorbus, Seifen-Öle-Fette-Wwachs, 114th year (1988), pp. 756 to 760). European patent application 291 869 (Henkel) describes phosphate-free builders combinations of zeolite and aminoalkane polyphosphonate and / or polymeric polycarboxylate and 1-hydroxyethane-1,1-diphosphonate (HEDP), certain weight ratios of the last three components being synergistic with regard to preventing the formation of fiber incrustations demonstrate.

Crystalline, layered sodium silicates have also been described as substitutes or partial substitutes for phosphates and zeolites. For example, European patent application 164 514 (Hoechst) discloses a phosphate-free builder combination which mainly contains crystalline phyllosilicates of the formula (I) NaMSi _x O _{2 + 1} .yH₂O, where M is sodium or hydrogen means x is a number from 1.9 to 4 and y is a number from 0 to 20 and preferred values for x 2, 3 or 4. These layered silicates can be used as water softeners both separately and in detergents and cleaning agents together with other builders such as phosphates, zeolite, other silicates, phosphonates and polycarboxylates.

Detergent is already described in German patent application 24 12 837 (Henkel), which, in combination with zeolite, contains various complexing agents such as polymeric polycarboxylates and phosphonates as well as alkaline framework substances, such as carbonates and silicates, which are not capable of complex formation. In this case, "microcrystalline" zeolites are preferably used, which are at least 80% by weight of particles having a size between 10 and 0.01 µm and in particular between 8 and 0.1 µm.

From the German patent application 25 25 778 (P&G) washing and cleaning agents are known which contain 0.5 to 3 wt .-% alkali silicate (calculated as a solid). These agents are prepared either by a conventional mixing process in which the solid silicates or a corresponding amount of a water glass solution are mixed together with the other main components, or by a spray drying process in which the slurry contains both zeolite and the corresponding amount of alkali silicate. The alkali silicates serve as corrosion inhibitors.

A detergent is known from German patent application 26 56 009 (Colgate) which contains 12 to 25% by weight of zeolite, in particular of type 4A, 5 to 20% by weight of a sodium silicate with the composition Na 2 O: SiO 2 of 1: 1 to 1 : 3.2, in particular from 1: 2.0 to 1: 2.6, and contains a peroxy bleach. According to the information in this reference, undesired deposits of the water-insoluble zeolite particles on the laundry are to be prevented by 0.3 to 3% by weight of a polymer from the group carboxymethyl cellulose, lower alkyl cellulose, hydroxy-lower alkyl-lower alkyl cellulose, polyvinyl alcohol, polyvinyl acetate and Polyvinyl pyrrolidone can be used. The zeolite has an average particle diameter of 0.5 to 12 μm, preferably 5 to 9 μm.

European patent application 10 247 (Henkel) describes a detergent which contains surfactants in conventional amounts, zeolite, alkali silicate and optionally a peroxy bleach. By adding water-soluble organic complexing agents from the group of substituted alkanedi- and alkanetri-phosphonic acids, which are present in the form of their alkali and / or alkaline earth salts, a detergent is obtained which not only has a good primary washing action, but also the formation of fiber incrustations reduced. In addition, the addition of these phosphonates results in increased bleaching stability despite the absence of conventional stabilizers such as magnesium silicate and aminopolycarboxylate. The agent contains 20 to 65 wt .-% of a finely divided zeolite, as described in German patent application DE 24 12 837, and 1 to 7 wt .-% solid, powdered sodium silicate of the molar composition Na₂O: SiO₂ from 1: 2 to 1: 2.2. The composition consists of a mixture of at least 2 powder constituents, the first of which is obtained by spray drying an aqueous slurry containing the zeolite, surfactants and optionally the water-soluble organic complex-forming framework substances, and the second powder constituent from the sodium silicate powder and optionally from the water-soluble phosphonates and other detergent additives that are sensitive to hydrolysis and / or temperature.

European patent application 240 356 (Unilever) discloses detergents which, in addition to zeolite and water-soluble sodium silicates, as described in European patent application 10 247, contain polymeric polycarboxylates and their derivatives, for example polyacrylates and salts of acrylic acid-maleic acid copolymers. These polymeric polycarboxylates are spray dried together with the zeolite during the production of the detergent.

From European patent applications 337 217 and 337 219 (Hoechst), builder combinations for detergents are known which contain crystalline phyllosilicates and optionally phosphates and polycarboxylates such as citrates, glykonates, NTA and / or iminodiacetates, but no zeolite. The agents, which contain 10 to 50% by weight of crystalline layered silicate, are characterized by a storage-stabilized bleaching system.

European patent application 405 122 (Hoechst) specifies a builder combination for textile detergents, the builder combination consisting of a mixture of zeolite and crystalline sodium phyllosilicate in a ratio of 4: 1 to 1: 4. By using a textile detergent that contains this builder combination, the incrustation of the fabric can be reduced.

The object of the invention was to further develop the field of phosphate-free builders combinations for use in textile detergents with the aim of reducing the proportion of organic synthetic compounds. Surprisingly, it has now been found that detergents which contain a special combination of finely divided zeolite with a relatively narrow particle size spectrum and alkali silicate as builders meet the high demands placed on modern detergents.

The invention relates to a detergent which contains surfactants, zeolite, alkali silicate and optionally a peroxy bleach and which is characterized in that it comprises 30 to 65% by weight of a finely divided, hydrated zeolite with an average particle size of 1 to 5 µm, 1 to 15 wt .-% of a solid alkali silicate of the molar composition M₂O: Si₂O from 1: 2.0 to 1: 3.0, wherein M is sodium and / or potassium, with the proviso that the agent is free of water-soluble organic Complexing agents from the group of substituted phosphonates, free of polymeric polycarboxylates and essentially free of alkali carbonates.

The finely divided, hydrated zeolite generally has a water content of 17 to 25% by weight. However, the quantities for zeolite relate to the anhydrous active substance. Suitable zeolites are those of the zeolite A type. Mixtures of zeolite NaA and NaX can also be used, the proportion of the zeolite NaX in such mixtures advantageously being less than 30%. Preferred zeolites have an average particle size between 1.8 and 4.5 μm, in particular between 2.0 and 4.0 μm (measurement method: Fraunhofer diffraction; mean volume distribution). The content of the agents in finely divided, in particular crystalline, hydrated zeolite is preferably 30 to 55 wt .-% and in particular 32 to 54 wt .-%, based on anhydrous active substance.

The solid alkali silicates can be amorphous or crystalline, as powder or as granules, for example as roller-compacted chip granules, or as a spray-dried compound. Preferred alkali silicates are the sodium silicates, in particular the amorphous sodium silicates, with a Na 2 O: SiO 2 molar ratio of 1: 2 to 1: 2.8. Such amorphous alkali metal silicates are commercially available, for example, under the name Portil ^(R) (Henkel). As crystalline silicates, which may be present alone or in a mixture with amorphous silicates, crystalline sheet silicates of the formula (I) NaMSi _x O _{2 + 1} .yH₂O are preferably used, in which M represents sodium, x assumes the values 2 or 3 and y is a number from 0 to 20. Both β- and δ-sodium disilicates Na₂Si₂O₅ are particularly preferred. The content of alkali silicates in the compositions is preferably 2 to 10% by weight and in particular 3 to 10% by weight, based on the anhydrous substance. In particular, the amorphous sodium silicate content of the agents is 3.5 to 8% by weight, based on the anhydrous substance. The weight ratio of zeolite: amorphous silicate, based in each case on anhydrous substance, is preferably 4: 1 to 10: 1. The crystalline layered silicates are preferably used in amounts of 2 to 7% by weight, the weight ratio of zeolite to crystalline layered silicate, based in each case on the anhydrous substance, being at least 5: 1. In compositions which contain both amorphous and crystalline alkali silicates, the weight ratio of amorphous alkali silicate: crystalline alkali silicate is preferably 1: 2 to 2: 1 and in particular 1: 1 to 2: 1.

The agents do not contain any water-soluble organic complexing agents from the group of the phosphonates, so that the agents have a calculated phosphorus content of 0%.

Polymeric polycarboxylates, for example polyacrylates, polymethacrylates, polymaleates or copolymers of acrylic acid with maleic acid or maleic anhydride, which are usually used in combination with zeolite, are also not present in the product according to the invention, since they do not improve its primary and secondary washability.

The agents are also essentially free of alkali carbonates, which means that they contain no more than about 5% by weight, preferably no more than 4% by weight and particularly advantageously no more than 3% by weight of alkali carbonates, in particular of sodium carbonate. Depending on the recipe, it cannot be ruled out that an alkali carbonate content in the range mentioned also contributes to increased incrustation. In the context of this invention it is therefore provided that alkali carbonate may only be added in the amounts in which it does not contribute to increased incrustation.

Preferred detergents contain peroxy bleach and in particular peroxy bleach in combination with bleach activators. Of the compounds used as bleaching agents, which supply H₂O₂ in water, sodium perborate tetrahydrate and sodium perborate monohydrate are of particular importance. Other bleaches that can be used are, for example, peroxycarbonate or peracidic salts of organic acids, such as perbenzoates or salts of diperdodecanedioic acid. Suitable bleach activators for these peroxy bleaches are, for example, the N-acyl or O-acyl compounds which form organic peracids with H₂O₂, preferably N, N'-tetraacylated diamines such as N, N, N'N'-tetraacetylethylenediamine. The content of peroxy bleaching agent in the agents is preferably 12 to 30% by weight, in particular in combination with 1 to 10% by weight, preferably 2 to 8% by weight, of a bleach activator.

The detergents according to the invention are not only distinguished by a reduced formation of fiber incrustations compared to agents of the prior art which usually contain polymeric polycarboxylates and / or alkali metal carbonates in larger amounts. Surprisingly, they also have an improved bleaching action or an improved stabilization of the peroxy bleaching agent, although they contain no conventional stabilizers such as phosphonate, magnesium silicate or other complexing agents such as the salts of nitrilotriacetic acid and ethylenediaminetetraacetic acid.

The detergents and cleaning agents contain known compounds from the group of anionic, nonionic and zwitterionic surfactants as further constituents. In particular, sulfonates come as anionic surfactants and sulfates and soaps from preferably natural fatty acids or fatty acid mixtures. C Tens-C₁₃ alkylbenzenesulfonates, olefin sulfonates, esters of α-sulfofatty acids or α-sulfofatty acid disalts are used, for example, as surfactants of the sulfonate type. Suitable surfactants of the sulfate type are the sulfuric acid monoesters from primary alcohols of natural or synthetic origin, ie from C₁₂-C₁₈ fatty alcohols or from C₁₀-C₂₀ oxo alcohols, and those of secondary alcohols of this chain length. The sulfuric acid monoesters of the alcohols reacted with 1 to 6 mol of ethylene oxide (EO) are also suitable. Addition products of preferably 2 to 20 moles of EO to 1 mole of an aliphatic compound with essentially 10 to 20 carbon atoms from the group of alcohols, carboxylic acids, fatty amines, carboxamides and alkanesulfonamides are of particular interest as nonionic surfactants. In addition to the water-soluble nonionic surfactants, polyglycol ethers with 2 to 7 ethylene glycol ether residues in the molecule that are not or not completely water-soluble are also important, in particular when they are used together with water-soluble nonionic or anionic surfactants. In addition, alkyl polyglycosides of the general formula RO- (G) _x can also be used as nonionic surfactants, in which R denotes a primary straight-chain or aliphatic radical with 8 to 22, preferably 12 to 18, C-atoms, methyl-branched, G is a symbol is a glycose unit with 5 or 6 carbon atoms, and the degree of oligomerization x is between 1 and 10.

The total content of surfactants in the compositions is generally between 5 and 40% by weight. It is preferably 5 to 30% by weight and in particular 8 to 25% by weight.

Other detergent and cleaning agent components, the proportion of which, depending on the composition of the detergent, is up to 40% by weight, preferably 5 to 30% by weight and in particular 8 to 20% by weight, include foam inhibitors, optical brighteners, enzymes, fabric softening agents, dyes and fragrances as well as neutral salts, solvents and water. The use of graying inhibitors, which are usually used in modern textile detergents, is not necessary and, in particular, is also not preferred.

Enzymes from the class of proteases, lipases, cellulases and amylases or their mixtures are possible. 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. The enzymes can be adsorbed on carriers and / or embedded in coating substances in order to protect them against premature decomposition.

Suitable non-surfactant-like and preferably used foam inhibitors are organopolysiloxanes and their mixtures with microfine, optionally silanized silica. Mixtures of different foam inhibitors are also advantageously used, e.g. B. from silicone and paraffins or waxes. The foam inhibitors are preferably bound to a granular, water-soluble or dispersible carrier substance.

In a preferred embodiment, powdery or granular detergents contain 10 to 30% by weight of surfactants, 30 to 45% by weight of a finely divided, hydrated zeolite with an average particle size of 2.0 to 3.8 μm, 2 to 10% by weight. % amorphous sodium silicate with a molar ratio Na₂O: SiO₂ of 2.0 to 2.8 or a mixture of the above amorphous sodium silicate with crystalline layered silicate, preferably β-sodium disilicate or δ-sodium disilicate, and 18 to 30% by weight peroxy bleach, preferably Perborate, and 2 to 8% by weight of a bleach activator, preferably TAED.

The detergents according to the invention can be prepared in a conventional manner, for example by mixing, granulating and / or by spray drying. It is possible to incorporate the builders zeolite and solid alkali silicate into the agents individually in a conventional manner and in any order.

The pourable powder or granular preparations preferably consist of a dry homogeneous mixture of at least 2 powder components, at least the first of which is in the form of spray-dried granules. It is done by a conventional way Spray drying of a slurry available which contains at least the anionic surfactants and optionally nonionic surfactants.

This slurry preferably additionally contains at least part of the zeolite and / or the silicate. In the event that the slurry contains zeolite, the slurry can contain a portion, but not more than 3% by weight and in particular not more than 2% by weight, in each case based on the total finished composition of the amorphous silicates contain. The rest of the amorphous alkali silicates present as powder or granules, like the crystalline sheet silicates which may be present, which are in granular form or adsorbed on a carrier which consists, for example, of sodium sulfate, are subsequently mixed into the spray product. In particular, however, it is preferred that the zeolite-containing slurry be free of amorphous alkali silicates and that these are subsequently added to the spray-dried product.

However, if the slurry does not contain zeolite, it is possible to incorporate the entire proportion of the amorphous alkali silicates into the slurry and to spray-dry them. In this case, however, the crystalline layered silicates which may be present are preferably not spray-dried, but are added subsequently in granular form or adsorbed onto a carrier. The zeolite is then also incorporated into the compositions as a powder or, preferably, as a commercially available compound, for example as Wessalith ^(R) CS or Wessalith ^(R) CB (commercial products from Degussa, Federal Republic of Germany).

It is also possible for a zeolite-containing and a silicate-containing slurry to be spray-dried separately and then mixed. However, it is particularly advantageous if the zeolite-containing slurry and the silicate-containing slurry are introduced into a spray tower at the same time.

Because of their thermal sensitivity, bleaching agents such as perborate are not spray-dried together with the constituents of the first powder component, but are also only added to the spray product afterwards.

Examples

Granular detergents of the following composition were produced and tested. The perborate, the bleach activator, the alkali silicate as well as enzyme granulate and silicone oil granulate were subsequently mixed into the spray-dried product from a slurry which contained the remaining constituents. The test was carried out under practical conditions in household washing machines (Miele W 717). The washing conditions are specified in more detail in the individual examples. The degree of whiteness was measured in a Zeiss reflectometer at 460 nm (suppression of the brightener effect). Remission differences of 2% and more are significant and directly understandable by the consumer.

Agent E according to the invention and comparative agent V had the following composition: E V C₁₂-alkylbenzenesulfonate sodium salt 8.0 8.0 C₁₂-C₁₈ fatty alcohol with 5 EO 5.5 5.5 C₁₂-C₁₈ fatty acid soap sodium salt 1.5 1.5 Zeolite NaA (anhydrous AS) average particle size 4.2 µm - 24.0 Zeolite NaA (anhydrous AS) average particle size 3.3 µm 38.0 - amorphous sodium silicate Na₂O: SiO₂ = 1: 2.0 5.5 - amorphous sodium silicate Na₂O: SiO₂ = 1: 3.3 - 3.5 Sodium carbonate (anhydrous) - 12.5 Acrylic acid-maleic acid copolymer sodium salt (Sokalan CP5 ( ^R) , commercial product from BASF, Germany) - 3.5 Sodium perborate tetrahydrate 25.0 25.0 TAED 2.0 2.0 1-hydroxyethane-1,1-diphosphonate - 0.4 Magnesium silicate - 1.1 Rest (enzyme, perfume, silicone oil, optical brightener, sodium sulfate, water) 14.5 13.0

Example 1: Stabilization of the peroxy bleach

Washing conditions:

Tap water of 17 ° d (equivalent to 170 mg CaO / l), main wash at 25 - 90 ° C (heating up time 60 minutes, 15 minutes at 90 ° C), liquor ratio (kg of laundry: 1 wash liquor in the main wash) 1: 4, rinse 5 times with tap water, spinning and drying; Dosage of the detergent: 146 g.

Anschmutzungen:

Fett-/Pigment-Anschmutzungen und bleichbare Anschmutzungen wie Rotwein, Tee, Kakao, Waldbeere

Der Versuch wurde dreimal wiederholt. Die angebenen Remissionswerte spiegeln die Durchschnittswerte über alle Messungen wider.The machines were loaded with 3.5 kg of normally soiled household linen (bed linen, table linen, underwear) and 0.5 kg of test fabric. Strips of standardized cotton fabric (Krefeld laundry research institute), of refined cotton fabric and of a mixed fabric of polyester and refined cotton were used as the test fabric.

Soiling:

Fat / pigment stains and bleachable stains such as red wine, tea, cocoa, wild berries

The experiment was repeated three times. The specified reflectance values reflect the average values across all measurements.

In two further test series, 5ppm and 10ppm divalent copper ions (Cu²⁺ in the form of copper sulfate) were added to the wash liquor added. The specified reflectance values also correspond to the average values across all measurements.

Table 1 shows that in the test series a) (detergent without the addition of copper), agents E and V have comparable performances. In the test series b) (detergent and 5ppm Cu²⁺), the detergent E according to the invention performed significantly better than V in all soiling. In the test series c) (detergent and 10ppm Cu²⁺) the performance difference between E and V in favor of E was even greater . Table 1 Trial series % Remission for detergent E V a) Detergent 73.9 74.4 b) Detergent + 5ppm Cu²⁺ 68.1 63.3 c) Detergent + 10ppm Cu²⁺ 53.3 47.7

Example 2 : secondary effects

Washing conditions: tap water of 23 ° d, 3.5 kg of clean laundry, dosage of detergent 146 g, 25 washes; all other parameters as in example 1.

From Table 2 it can be seen that both the ash content (measured on terry cloth) and the incrustation (measured weight gain on bleaching nettle tissue) are higher for the comparative agent V than for the agent E. Table 2 medium % Ash (terry) % Incrustation (bleaching nettle) E 1.37 2.54 V 2.82 3.40

Comparable results were obtained in the remission measurement if, instead of 5.5% by weight of an amorphous sodium silicate with the molar ratio Na₂O: SiO₂ of 1: 2.0, an amorphous sodium silicate with a molar ratio of 1: 2.6, a crystalline β Disilicate or a mixture of 3.5% by weight of an amorphous sodium silicate and 2% by weight of a crystalline δ-disilicate were used.

Claims (11)

1. A detergent containing surfactants, zeolite, alkali metal silicate and optionally a peroxy bleaching agent, characterized in that it contains 30 to 65% by weight of a fine-particle hydrated zeolite having an average particle size of 1 to 5 µm, 1 to 15% by weight of a solid alkali metal silicate of the molar composition M₂O:SiO₂ = 1:2.0 to 1:3.0, where M is sodium and/or potassium, with the proviso that the detergent is free from water-soluble organic complexing agents from the group of substituted phosphonates, free from polymeric polycarboxylates and substantially free from alkali metal carbonates.
2. A detergent as claimed in claim 1, characterized in that it contains 30 to 50% by weight and preferably 32 to 45% by weight of a fine-particle hydrated zeolite having a mean particle size of 1.8 to 4.5 µm and preferably 2.0 to 4.0 µm and 2 to 10% by weight and preferably 3 to 8% by weight sodium silicate with a molar ratio of Na₂O to SiO₂ of 1:2.0 to 1:2.8.
3. A detergent as claimed in claim 1 or 2, characterized in that it contains 12 to 30% by weight of a peroxy bleaching agent, preferably in combination with 1 to 5% by weight of an activator for the peroxy bleaching agent.
4. A detergent as claimed in any of claims 1 to 3, characterized in that it contains 2 to 7% by weight of a crystalline layer silicate having the formula Na₂Si₂O₅·_yH₂O, where y is a number of 0 to 20, and the ratio of zeolite to crystalline layer silicate is at least 5:1.
5. A detergent as claimed in any of claims 1 to 3, characterized in that it contains zeolite and amorphous alkali metal silicate in a ratio by weight of 4:1 to 10:1.
6. A detergent as claimed in any of claims 1 to 5, characterized in that it contains amorphous alkali metal silicate and crystalline alkali metal silicate in a ratio by weight of 1:2 to 2:1 and preferably 1:1 to 2:1.
7. A detergent as claimed in any of claims 1 to 6, characterized in that it contains no more than 4% by weight and preferably no more than 3% by weight alkali metal carbonates, particularly sodium carbonate, with the proviso that the alkali metal carbonate is only added in quantities in which it does not contribute to increased incrustation.
8. A process for the production of the detergent claimed in any of claims 1 to 7, characterized in that a slurry containing the anionic surfactants, at least part of the zeolite, a part, but no more than 3% by weight and preferably no more than 2% by weight, based on the final detergent as a whole, of the amorphous silicates and optionally nonionic surfactants is spray-dried.
9. A process as claimed in claim 8, characterized in that the zeolite-containing slurry is free from amorphous alkali metal silicates which are subsequently added as a whole to the spray-dried product together with the crystalline layer silicates optionally present.
10. A process for the production of the detergent claimed in any of claims 1 to 7, characterized in that a slurry containing the anionic surfactants, amorphous silicates and optionally nonionic surfactants is spray-dried and the zeolite is subsequently added to the spray-dried product.
11. A process for the production of the detergent claimed in any of claims 1 to 7, characterized in that a zeolite-containing slurry and a silicate-containing slurry are simultaneously introduced into a spray drying tower.