CH677930A5 - - Google Patents

Description

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description

The present invention relates to an aqueous, little or no phosphorus detergent composition containing water, chlorine bleach-stable, water-dispersible organic surfactant, alkali metal silicate, chlorine bleach and detergent builder. The composition according to the invention is particularly suitable for automatic dishwashers. In particular, the invention relates to those compositions which do not contain phosphate builders, but which show comparable or better rinsing behavior than similar automatic dishwasher detergent compositions containing phosphorus.

The invention also relates to a commercial method for washing dirty dishes in an automatic dishwasher.

The composition according to the invention has viscoelastic properties, an improved chemical and physical stability and an improved rinsing behavior despite the absence of phosphate builder salts. It is quickly dispersible in the washing medium to enable effective cleaning of dishes, glass, porcelain and the like.

The commercially available household dishwashing detergents in powder form have various night forms, e.g. non-uniform composition; costly measures required to manufacture them; a tendency to cake when stored under increased humidity, which leads to the formation of lumps which are difficult to disperse; Dustiness, a source of particular irritation for consumers suffering from allergies; and a tendency to cake in the dishwasher dispenser compartment. However, liquid forms of these compositions generally cannot be used in automatic dishwashers due to high foaming, unacceptably low viscosities, and excessively high alkalinity.

Recent research and development has focused on the "gel" or "thixotropic form" of such compositions, such as cleaning agents and automatic dishwashing products, which are characterized by being thixotropic liquids or pastes. The dishwashing products created in this way are not faultless, above all because they are insufficiently viscous to remain "anchored" in the dishwasher's dispenser compartment, and they also lead to stained residues on the dishes, glass, porcelain and the like.

Especially with regard to compositions for use in home dishwashers, it has hitherto proven to be problematic to provide automatic dishwashing detergent compositions in gel form which have satisfactory dispensing stability and cleaning properties. For good effectiveness in use, it is generally recommended that the automatic dishwashing detergent, hereinafter referred to as ADD (automatic dishwashing detergent), contain: (1) sodium tripolyphosphate (NaTPP) to soften or hold water-hardening minerals and to emulsify and / or peptize dirt; (2) sodium silicate to provide the alkalinity required for effective rinsing and to protect the luster and structure of fine porcelain; (3) sodium carbonate, which is generally considered to be optional to increase alkalinity; (4) a chlorine-releasing agent to help remove stains that lead to water stains; and (5) defoamer / surfactant to reduce foam, thereby increasing machine efficiency and providing the required rinse action. Compare for example: SDA Détergents in Depth, “Formulations Aspects of Machine Dishwashing”, Thomas Oberle (1974). Detergents, which roughly correspond to the compositions described above, are mostly liquids or powders. The combination of these components in thickened form, which is useful for use in home machines, has proven difficult. In general, the hypochlorite bleach is omitted from these compositions because it tends to react with the other chemically active ingredients, particularly the surfactant, degrading the detergent or thickener and adversely affecting its effectiveness.

U.S. Patent 4,115,308 describes thixotropic automatic dishwashing pastes) which contain a retention agent, e.g. CMC, synthetic clays or the like, inorganic salts including silicates, phosphates and polyphosphates, a small amount of surfactant and a foam barrier. A bleaching agent is not described. On the other hand, an alkali metal hypochlorite bleaching and cleaning agent composition is known from US Pat. No. 3,684,722 which is thickened with mixtures of Cs-Cjs alkali metal soaps and hydrotropes such as amine oxide and betaines.

Tests have been reported to show that various classes of organic polymer thickeners were either unstable or otherwise unable to provide adequate thickening or loss of available chlorine. It was found that polyacrylates thickened for a few weeks at room temperature, but then decomposed.

US Pat. No. 3,985,668 describes abrasive cleaning agents with a gel-like consistency, which contain: (1) a retention agent, preferably smectic and attapulgite type clay; (2) an abrasive, e.g. Silica sand or perlite; and (3) filler comprising low density powdered polymers, expanded perlite and the like which has a buoyancy and thus a stabilizing effect on the composition in addition to serving as a bulking agent, thereby replacing water which otherwise due to leakage and phase destabilization

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would be available for the formation of an undesirable protruding layer. Optional ingredients include hypochlorite bleach, bleach-stable surfactant and buffer, e.g. Silicates, carbonates and monophosphates. Builders such as NaTPP can be added as additional optional ingredients to provide or support the builder function that is not provided by the buffer, the amount of the builder according to the patent should not exceed 5% of the total composition. The maintenance of the desired pH value (greater than) 10 is achieved by the buffer / builder components. High pH is said to minimize chlorine bleach degradation and undesirable surfactant-bleach interaction. The NaTPP is said to be limited to 5% by weight when it is present. A foam brake is not described.

British patent applications 2 116 199A and 2140 450A disclose liquid ADD (LADD) compositions which have desirable properties which can be characterized as a thixotropic, gel-like structure and which contain various constituents which are necessary for good cleaning effects in an automatic dishwasher are. The normally gel-like, aqueous, automatic dishwashing detergent composition with thixotropic properties comprises the following components:

(a) 5 to 35 weight percent alkali metal tripolyphosphate;

(b) 2.5 to 20% by weight sodium silicate;

(c) 0 to 9 weight percent alkali metal carbonate;

(d) 0.1 to 5% by weight of chlorine bleach-stable, water-dispersible, organic, cleaning-active material;

(e) 0 to 5% by weight foam reducer stable against chlorine bleach;

(f) a chlorine bleach compound in an amount that provides about 0.2 to 4 percent by weight of available chlorine;

(g) a thixotropic thickener in an amount sufficient to impart a thixotropic value of about 2.5 to 10 to the composition;

(h) the sodium hydroxide required to adjust the pH; and

(i) water.

The LADD compositions thus formulated are not very foaming; they dissolve quickly in the rinsing medium and work best at alkaline pH values. The compositions usually have a gel consistency, i.e. they are highly viscous; they are an opaque, gel-like material with a Bingham-plastic character and accordingly high flow values.

A certain shear force is therefore required in order to initiate or increase the flow, as is obtained in operation in the dispensing container of an automatic dishwasher which is exposed to movement. Under these conditions, the composition is quickly liquefied and easily dispersed. When the shear force is released, the liquid composition quickly returns to a highly viscous, Bingham-plastic state that is very close to its previous consistency.

In US-PS 4511 487 dated April 16, 1985, a low-foaming detergent paste for dishwashers is described. The thixotropic detergent has a viscosity of at least 30 Pa.s at 20 ° C as determined with a rotary viscometer at a spindle speed of 5 revolutions per minute. The composition is based on a mixture of finely divided hydrated sodium tripolyphosphate and hydrated sodium metasilicate, an active chlorine compound and a thickening agent, which is a leafy silicate of the hectorite type. Small amounts of nonionic surfactants and alkali metal carbonates and / or hydroxides can also be used.

Various modifications and improvements to the liquid automatic dishwashing detergent compositions of British patent applications 2 116 199A and 2 140 450A have recently been developed. For example, US Pat. No. 816,835 describes an aqueous, gel-like, thixotropic, clay-free and polymer thickener-free, liquid detergent composition in which a mono- or polycarboxylic acid having 8 to 22 carbon atoms is used to impart physical stability and thixotropic properties.

According to US application SN 903 924, the physical stability of a clay-based thixotropic, liquid, builder-containing automatic dishwashing detergent composition is achieved by adding small amounts, for example about 0.02 to 1% by weight, of a polyvalent salt of a long-chain fatty acid such as aluminum stearate.

The majority of these commercially available liquid dishwashing detergents and similar compositions described are dependent on phosphate builder salts, such as sodium tripolyphosphate, to enhance the cleaning effect. Although phosphate builder salts are extremely effective for this purpose, their use has one major disadvantage: they generally damage water life and watercourses. As a result, many legislators have already banned, or are considering, a general ban on detergents and cleaning agents containing phosphates.

While many attempts have been made to create alternative builders, and many such inorganic and organic non-phosphate cleaning builder salts are known, very few are able to achieve cleaning effects as favorable as those of phosphate builders in practice3

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ensure. Furthermore, the selection of suitable builders is made more difficult by the medium of the bleach-containing aqueous compositions under consideration, because the alternative builder must be compatible with chlorine bleach.

In addition to its function as a detergent builder, the inorganic aicali metal phosphate salt builder fulfills an important function in that it contributes to the rheological properties of the thickened, thixotropic, gel-like, liquid, aqueous detergent composition as described above with reference to British patent applications 2 116 199A and 2 140 450A. The replacement of the phosphate builder with a non-phosphate builder accordingly did not prove to be an easy task, because so many different factors have to be taken into account if the multifunctional tasks of the phosphate builder are to be fulfilled.

Accordingly, the main object of the invention is to provide aqueous, bleach-containing detergent compositions which avoid the use of phosphate builders and which contain no or only environmentally compatible amounts of phosphorus from other sources.

It is also an object of the invention to provide thickened liquid ADD compositions containing little or no phosphate, with improved physical stability and improved rheological properties.

It is also an object of the invention to provide thickened, aqueous ADD compositions which have no or low phosphorus contents, the rinsing behavior, in particular low staining and fog formation, not to be adversely affected or improved.

The object is achieved by an aqueous detergent composition containing little or no phosphorus, which comprises water, a chlorine bleach-stable, water-dispersible organic surfactant, a chlorine bleach, an alkali metal silicate and a detergent builder, the detergent builder being a mixture of aluminosilicate zeolite and a carboxyl group-containing, bleach-stable, water-soluble polymer or its salt. A preferred embodiment of the invention relates to a thickened, viscoelastic, liquid automatic dishwashing detergent composition which is free of phosphate builder salts and contains no or only small amounts of phosphorus and which is effective in settling water-insoluble suspended particles such as the aluminosilicate zeolite builder, bleach particles, etc. prevented. The composition may include clay or other thickeners, as well as other stabilizers and other conventional ADD additives.

The invention preferably relates to a gel-like, aqueous automatic dishwasher detergent composition with viscoelastic properties

(a) 5 to 35% by weight of aluminosilicate zeolite,

(b) 25 to 40% by weight sodium silicate,

(c) 0 to 9% by weight of alkali metal carbonate,

(d) 0.1 to 5% by weight of a water-dispersible, organic, cleaning-active material which is stable to chlorine bleach,

(e) 0 to 5% by weight of a foam brake which is stable to chlorine bleach,

(f) a chlorine bleach in an amount to ensure 0.2 to 4% by weight of available chlorine,

(g) 0 to 0.5% by weight of a long-chain fatty acid or its salts,

(h) 0 to 5% by weight of an inorganic, colloid-forming clay thickener,

(i) 0 to 8% by weight sodium hydroxide

(j) 0.5 to 10% by weight of a water-soluble carboxyl group-containing polymer or salts thereof which is stable to bleaching agents and

(k) includes water.

The invention also relates to a commercial process for washing dishes in an automatic dishwasher with a rinse water containing an effective amount of the liquid automatic dishwashing detergent (LADD) composition described above. The LADD composition can be easily poured into the release container of the automatic dishwasher and it is sufficiently viscous to remain safely in the release container until shear forces are applied to it, such as from water splashes from the dishwasher, whereupon the flow limit of the composition is exceeded and the composition flows.

The invention will now be described in more detail with reference to specific embodiments.

Given the concerns about the environment that cause the problem of silting up lakes, rivers and other bodies of water attributed to the introduction of phosphorus from detergents and other products into the waters, it has been strongly requested that the phosphates be removed from detergents and cleaning agents «

Attempts to replace the phosphate builder in thixotropic, liquid automatic dishwasher detergent compositions, which typically contain 0 to 3% by weight of clay as a thickener - generally of the smectic, water-swelling type, 10 to 25% by weight of alkali metal silicate, 0 to 0.5% by weight fatty acid stabilizer, small amounts of bleach, bleach-stable surfactant, bleach-resistant antifoam, sodium carbonate, caustic soda and the like and about 20 to 25% by weight of alkali

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metal phosphate salt as detergent builders, but have resulted in loss of thixotropic properties and usually deterioration in cleaning performance. While the exact mechanism of the change in rheological properties leading to loss of thixotropy has not been fully established, it appears to be that there are at least some interactions between the suspended phosphate bromide particles and the other components of the formulation, particularly the clay Thickener and the fatty acid or fatty acid salt stabilizer and that these interactions help to increase the flow value and the plastic viscosity of the composition.

The surprising fact is assumed that similar rheological properties and physical stability, i.e. Resistance to phase separation, settling, etc., as they have these known, phosphate builders containing liquid, aqueous ADD compositions, can be achieved by adding to the composition aluminosilicate zeolite as an inorganic, water-insoluble cleaning agent builder in a mixture with a water-soluble, carboxyl group which is stable against bleaching agents containing polymer as a multifunctional rheological agent and detergent and the amount of alkali metal silicate is preferably increased to more than 25% by weight. At the same time, an improvement in the behavior with regard to staining and deposits (i.e. fewer stains and reduced deposits) can be achieved.

Although the compositions according to the invention have no thixotropic properties, they have viscoelastic properties and a flow value (maximum stress in a curve: shear stress versus shear rate) which is sufficiently high that it is under the force exerted by its own weight, i.e. the gravitational force does not flow. Therefore, the compositions according to the invention can easily be poured into the dispensing container of an automatic dishwasher and they do not flow out until sufficiently high shear force, for example the force of water splashes, which penetrate into the container during the detergent distribution process, is applied.

If physical stability is not required for extended periods of several weeks or months, and if it is not necessary to create a very thickened solution, then the large amounts of silicate, clay thickener and / or fatty acid or fatty acid salt stabilizer can be omitted from the formulation without adversely affecting the cleaning action, which is ensured by the aluminosilicate zeolite builder and the water-soluble polymer which is stable to bleaching agents and contains carboxyl groups (or their salt).

The builders that can be used are water-insoluble aluminosilicates of both the crystalline and the amorphous type. Various crystalline zeolites are described in British Patent 1,504,168, US Pat. No. 4,409,136 and Canadian Patents 1,072,835 and 1,087,477, which are hereby incorporated by reference into the scope of these descriptions as part of the present description. An example of amorphous zeolites that are useful can be found in Belgian Patent 835,351; this patent is also incorporated in the present specification by reference. The zeolites generally have the formula

(M20) x. (AI203) r (Si02) z-WH20,

in which X1 is, y is 0.8 to 1.2 and preferably 1, z is 1.5 to 3.5 or greater and preferably 2 to 3 and w is 0 to 9, preferably 2.5 to 6 and M is a Alkali metal, preferably sodium or potassium, especially sodium. A typical zeolite is of type A or has a similar structure, with type 4A being particularly preferred. The preferred aluminosilicates have exchange capacities for calcium ions of about 200 milliequivalents per gram or larger, e.g. 400 meq / g.

The aluminosilicate zeolite builder can be present in the compositions in the same amounts useful for the alkali metal polyphosphate builders, generally in the range of 5 to 35 percent by weight, preferably 20 to 30 percent by weight on the composition.

The usable, carboxyl group-containing, bleach-stable, water-soluble polymers include, for example, the acrylic acid homopolymers and copolymers and their salts. These materials are generally commercially available and can be described as follows.

The polyacrylic acid polymers and their salts that can be used include low molecular weight water-soluble polymers of the formula

Rl R2

C C

r3 coom

I »

t I

n i

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in which Ri, R2 and R3 can be the same or different and can be hydrogen, Ci-C4-lower alkyl or combinations thereof, n is a number from 5 to 250, preferably 10 to 150 and in particular 20 to 100 and M is hydrogen or an alkali metal such as sodium or potassium. The preferred substituent IVI is sodium.

The preferred groups Ri, R2 and R3 are hydrogen, methyl, ethyl and propyl. The preferred acrylic acid monomer is one in which Ri and R3 are hydrogen, e.g. Acrylic acid, or where Ri and R3 are hydrogen and R2 is methyl, e.g. the methacrylic acid monomer.

The degree of polymerization, i.e. the value of n is generally determined by the limit set by the solubility of the polymer or copolymer in water. The terminal or end groups of the polymer or copolymer are not critical and can be H, OH, CH3 or a low molecular weight hydrocarbon group.

Typically, the polyacrylic acid copolymers include, for example, copolymers of acrylic acid or methacrylic acid and a polycarboxylic anhydride or an acid such as succinic anhydride, succinic acid, maleic acid, maleic anhydride, citric acid and the like. Copolymers of acrylic acid or methacrylic acid with maleic anhydride are preferred.

The acrylic acid or methacrylic acid monomer usually makes up 40 to 60% by weight, e.g. about 50% by weight of the copolymer with a carboxylic acid or its anhydride.

The polyacrylic acid polymer can have a (weight average) molecular weight of 500 or 1000 to 25,000, preferably 1500 to 15,000 and in particular 2000 to 10 0Q0. The copolymers can have higher molecular weights, e.g. up to 100,000.

Individual examples of polyacrylic acid polymers that can be used include the Röhm and Haas Acrylsol LMW acrylic acid polymers, such as the Acrylsol LMW-45NX, which is a neutralized sodium salt, which has a molecular weight of about 4500, and Acrysol LMW-20NX, which is a neutralized Is sodium salt, which has a molecular weight of about 2000.

A specific example of a polyacrylic acid copolymer that can be used is Sokalan CP5 (from BASF), which has a molecular weight of about 70,000 and is the reaction product of about equimolar amounts of methacrylic acid and maleic anhydride, which has been completely neutralized to avoid this To form sodium salt.

The above polymers and copolymers can be produced by known methods. Compare e.g. U.S. Patent 4,203,858.

The water-soluble, carboxyl group-containing, bleach-stable polymers perform three main functions in the liquid automatic dishwasher detergent compositions according to the invention: control of the rheology, sequestration of the calcium and dispersion of dirt.

The polymer additive appears to act as a thickener as a means of controlling the rheology, and together with the large amounts of alkali metal silicate, clay (if present) and fatty acid or its salt (if present) it gives the composition viscoelasticity and a plastic viscosity in the range from about 200 to 10,000 mPas, preferably 2,000 to 8,000 mPas, e.g. 5000 mPas. The desired ranges of viscoelasticity and plastic viscosity are best achieved if the molecular weight is not greater than 10,000, preferably about 2,000 to 10,000, e.g. is about 4000 to 5000.

As far as the action as calcium sequestrant is concerned, it is important that the polymer has a particularly good water solubility. Again, the best results are obtained if the polymer has a molecular weight of 10,000 or less, in particular 2,000 to 10,000.

Molecular weights of the polymer additive in the range from 2000 to 10,000 are also preferred with regard to their action as soil dispersant, which contributes to the desired anti-stain and anti-film-forming properties.

The amount of polyacrylic acid polymer or copolymer additive required to achieve the desired improvement in physical stability and cleaning performance depends on factors such as the amount and type of fatty acid or salts (if any), the type and amount the clay as a thickener (if present), the active cleaning compound, the bleaching agent and the foreseeable storage and shipping conditions.

In general, however, the amounts of polyacrylic acid polymer or copolymer additive which can be used are in the range from 0.5 to 10% by weight, preferably 0.80 to 8.0% by weight and in particular 2 to 6% by weight. %.

Useful detergent-active materials must be stable in the presence of chlorine bleach, especially hypochlorite bleach, and the water-dispersible organic anionic, amine oxide, phosphine oxide, sulfoxide or betaine surfactant types are preferred, with the first-mentioned anionic type being particularly preferred. They are used in amounts in the range from 0.1 to 5% by weight, preferably 0.3 to 2% by weight.

Particularly preferred surfactants are the linear or branched alkali metal mono- and / or di (Cs-Ci4) -alkyldipheny! Oxide mono- and / or disulfates, which are commercially available, for example, as DOWFAX (registered trademark) 3B-2 and DOWFAX 2A-1 are available. The paraffin sulfates generally tend to increase viscosity inappropriately, causing considerable problems in shear. Furthermore, the surfactant should be compatible with the other components of the composition. Other suitable surfactants are primary alkyl sulfates, alkyl sulfonates, alkylaryl

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sulfonates and sec-alkyl sulfates. Examples are cio-cis sodium alkyl sulfates such as sodium dodecyl sulfate and sodium tallow alcohol sulfate; Cio-Ci8 sodium alkanesulfonates, such as sodium hexadecyl-1-sulfonate and Cii-Ci8 sodium alkylbenzenesulfonates, such as sodium dodecylbenzenesulfonate. The corresponding calcium salts can also be used.

Other suitable surfactants or detergents are the amine oxide surfactants, which typically have the structure RaR1NO, in which R is a lower alkyl group, for example methyl, and in which R1 is a long-chain alkyl group having 8 to 22 carbon atoms, for example a lauryl or myristyl -, Palmityl or cetyl group means. Instead of an amine oxide, a corresponding surface-active phosphine oxide R2R1PO or suifoxide RR1SO can be used. Betaine surfactants typically have the structure R2R1N-R "COO-, in which each R represents a lower alkylene group having 1 to 5 carbon atoms. Specific examples of these surfactants are lauryldimethylamine oxide, myristyldimethylamine oxide, the corresponding phosphite oxides and sulfoxides and the corresponding betaines including dodecyldimethylammonium acetate, tetradecyldiethylammonium pentanoate, hexadecyldimethylammonium hexanoate, etc. Because of the biodegradability, the alkyl groups in these surfactants should be linear, and therefore such compounds are preferred,

Surfactants of the above type are known to the person skilled in the art and are described, for example, in US Pat. Nos. 3,985,668 and 4,271,030.

Any chlorine bleach compound can be used in the compositions according to the invention, for example dichloroisocyanurate, dichlorodimethylhydantoin or chlorinated TSP, but alkali metal, e.g. Potassium, lithium, magnesium and especially sodium hypochlorite are preferred. The composition should contain enough of the chlorine bleach compound to provide 0.2 to 4% by weight of available chlorine, for example as determined by acidifying 100 parts of the composition with excess hydrochloric acid. A solution containing 0.2 to 4.0% by weight sodium hypochlorite ensures roughly the same percentage of available chlorine. 0.8 to 1.6% by weight of available chlorine is particularly preferred. For example, a sodium hypochlorite solution (NaOCl) with 11 to 13% by weight of available chlorine in amounts of 3 to 20% by weight, preferably 7 to 12% by weight, can be used with advantage.

Sodium or potassium silicate, which ensures alkalinity and protection of hard surfaces, such as the gloss and structure of fine porcelain, is normally used in an amount in the range from 2.5 to 20 or 25% by weight. In larger quantities than about 10% by weight, the silicate also ensures an improved anti-stain effect.

In the viscoelastic, physically stable, liquid, aqueous automatic dishwasher detergent compositions preferred according to the invention, however, it is essential that the alkali metal silicate is incorporated in amounts which are above the amounts which are normally used, in particular in more than 25% by weight. for example 28% by weight to 40% by weight, in particular 30 to 38% by weight of the composition.

The sodium silicate is generally added in the form of an aqueous solution which preferably has a Na20: SiO2 ratio of about 1: 2.2 to 1: 2.8, for example 1: 2.4. Most of the other components of the composition, in particular NaOH, sodium hypochlorite and antifoam, can also be added in the form of an aqueous dispersion or solution.

Foam inhibition is important in order to increase the effectiveness in the dishwasher and to minimize the destabilizing effects that occur in the presence of excess foam in the dishwasher. The foam formation can be reduced to a sufficient extent by a suitable choice of the type and / or the amount of the cleaning-active material which is the main foam-forming component. The extent of the foam formation also depends to a certain extent on the hardness of the rinsing water in the machine, which is why an appropriate setting of the proportion of NaTPP that has a water softening effect can help to ensure the desired level of foam inhibition. However, it is generally preferred to incorporate a bleach reducer or foam inhibitor that is stable to bleach. If a certain phosphorus content can be tolerated, the alkylphosphonic acid esters of the formula are particularly effective in this regard

O

HO P R

OR

and especially the alkyl acid phosphate esters of the formula

O

HO? OR.

Ór

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In the above formulas, one or both of the R groups in each type of ester can independently represent Cia-Cao-alkyl groups. The ethoxylated derivatives of the two ester types, for example the condensation product of one mole of ester with 1 to 10 moles, preferably 2 to 6 moles, in particular 3 to 4 moles of ethylene oxide, can also be used. Some examples of the above products are commercially available, such as the SAP product from Hooker and LPKn-158 from Knapsack. Mixtures of the two types or any other type stable to chlorine bleach, or mixtures of mono- and di-esters of the same type can be used. A mixture of Ci6-Ci8-mono- and di-alkyl acid phosphate esters, such as monostearyl / distearyl acid phosphates 1.2 / 1, and their condensates with 3 to 4 moles of ethylene oxide is particularly preferred. If they are used, then proportions of 0.01 to 0.5% by weight, preferably 0.02 to 0.4% by weight, in particular approximately 0.1 to 0.2% by weight, of the foam reducer are in typical of the composition, the weight ratio of detergent active to suds reducer generally being in the range of about 20: 1 to 4: 1 and preferably about 10: 1 to 5: 1. With these small amounts of anti-foam middle! the total phosphorus content in the composition is generally and preferably not more than 0.01% by weight, based on the total composition.

If it is desired to completely exclude phosphorus, then any of the known silicone anti-foaming agents compatible with bleaching agents can be used. In the case of the thickened LADD compositions preferred according to the invention, thickening is ensured by inorganic, water-swelling, colloid-forming clays of the smectic and / or attapulgite type. These materials can generally be used in amounts of about 0.1 to 10, preferably 1 to 5% by weight to impart the desired properties. In the presence of fatty acid or fatty acid metal salt stabilizers, however, smaller amounts of the inorganic, colloid-forming clays of the smectic and / or attapulgite type can also be used. For example, amounts of clay in the range of about 0.1 to 3% by weight, preferably 0.1 to 2.5% by weight and in particular 0.1 to 2% by weight, are generally sufficient to achieve the desired viscoelastic To achieve properties when used in combination with the fatty acid (or fatty acid salt) stabilizer and the other specified ingredients.

Smectic clays include montmorillonite (bentonite), hectorite, attapulgite, smectite, saponite and the like. Montmorillonite clays are preferred and commercially available under the trade names such as Thixogel (registered trademark) No. 1 and Gelwhite (registered trademark) GP, H, etc. from Georgia Kaolin Company, and ECCAGUM (registered trademark) GP, H etc. from Luthern Clay products available. The attapulgite clays include the materials that are commercially available under the trade name Attagel (registered trademark), i.e. Attagel 40, Attagel 50 and Attagel 51, available from Engehard Minerals and Chemicals Corporation. Mixtures of the smectic and attapulgite types in weight ratios of 4: 1 to 1: 5 are also useful. The thickening or retaining agents of the types mentioned above are known to the person skilled in the art.

By adding a small but effective amount of a long chain fatty acid or a metal salt thereof, the physical stability, i.e. the resistance to phase separation, settling, etc. of these liquid, aqueous ADD compositions can be significantly improved. Under the preferred conditions at alkaline pH of the LADD composition, i.e. pH 10.5 to 13.5, the fatty acids are converted into the corresponding alkali metal salts.

Preferred long chain fatty acids are the higher aliphatic fatty acids having about 8 to 22 carbon atoms, preferably about 10 to 20 carbon atoms and especially about 12 to 18 carbon atoms including the carbon atom of the carboxyl group of the fatty acid. The aliphatic residue can be saturated or unsaturated and it can be linear or branched. Straight chain, saturated fatty acids are preferred. Mixtures of fatty acids can be used, such as those obtained from natural sources such as tallow fatty acid, coconut fatty acid, soy fatty acid, etc., or are available from synthetic sources from industrial manufacturing processes.

Examples of the fatty acids include decanoic acid, dodecanoic acid, palmitic acid, myristic acid, stearic acid, oleic acid, eicosanoic acid, tallow fatty acid, coconut fatty acid, soy fatty acid, mixtures of these acids, etc. Stearic acid and mixed fatty acids are preferred.

The metal salts of the fatty acids can also be used, and any monovalent or polyvalent metal can be used. The monovalent metals include, for example, the alkali metals, especially sodium or potassium. Sodium salts (soaps) are particularly preferred.

The preferred multivalent metals are the multivalent metals of groups IIA, IIB and HIB of the periodic table of the elements, such as magnesium, calcium, aluminum and zinc, although other multivalent metals, including those of groups IIIA, IVA, VA, IB, IVB, VB, VIB, VIIB and VIII of the Periodic Table of the Elements can also be used. Certain examples of these other polyvalent metals include Ti, Zr, V, Nb, Mn, Fe, Co, Ni, Cd, Sn, Sb, Bi, etc. In general, these metals can exist in the divalent to pentavalent state. The polyvalent metals are preferably used in their higher oxidation states. In LADD compositions as well as in other applications in which the composition according to the invention comes into contact with objects which are used for the handling, storage or serving of food or which come into contact with people or animals in another way or are consumed by them , the metal salt should of course be selected so that the toxicity of the

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Metal. For this purpose, calcium and magnesium salts are particularly preferred as generally safe food additives.

Many of these metal salts are commercially available. For example, the aluminum salts are available in the triacid form, e.g. Aluminum stearate as aluminum tristearate, AI (Ci7H3sCOO) 3. The mono acid salts, e.g. Aluminum monosterate and the diacid salts, e.g. Aluminum distearate, and mixtures of two or three of the mono-, di- or tri-acid salts can be used with metals of valence +3, e.g. AI, and mixtures of the mono- and diacid salts can be used with metals of value +2, e.g. Zn can be used. It is most preferred that the diacids of the + 2-valent metals and the triacids of the + 3-valent metals, the tetra acids of the + 4-valent metals and the penta-acids of the + 5-valent metals are used in predominant amounts.

The metal salts mentioned above are generally available commercially, but they can be easily prepared, e.g. by saponification of a fatty acid, e.g. animal fatty acid, stearic acid, etc., or the corresponding fatty acid ester, followed by a hydroxide or oxide of the polyvalent metal, e.g. in the case of the aluminum salt, treated with alum, alumina, etc., or by reacting a soluble metal salt with a soluble fatty acid salt.

Calcium stearate, i.e. Calcium distearate, magnesium stearate, i.e. Magnesium distearate, aluminum stearate, i.e. Aluminum tristearate and zinc stearate, i.e. Zinc distearate are the preferred polyvalent fatty acid salt stabilizers.

Mixed fatty acids such as the naturally occurring acids, e.g. Cocoic acid, as well as mixed fatty acids that are available from industrial manufacturing processes, are also used advantageously as an inexpensive but effective source of long chain fatty acids.

In addition, the dimers or trimers of these acids can also be used.

The amount of fatty acid or fatty acid salt stabilizers to achieve the desired physical stability depends on factors such as the type of fatty acid (or its salt), the type and amount of clay thickener, the cleaning compound, the inorganic salts, and other LADD- Components, as well as the foreseeable storage and sales conditions. In general, however, amounts of stabilizing agents from polyvalent metal salts of fatty acids in the range from approximately 0.02 to 1% by weight, preferably approximately 0.06 to 0.8% by weight, in particular approximately 0.08 to 0.4% by weight, ensure % Long-term stability and avoidance of phase separation when standing or during transport, both at low and at elevated temperatures, as is desired for a commercially acceptable product.

Although it is not desirable to be bound by any particular theory regarding the operation of the fatty acid (metal salt) stabilizers, it is hypothesized that these stabilizers, which are anionic salts under alkaline conditions, with the surface of the cationic clay particles , which are used as thickeners, interact, thereby helping the fatty acid units to keep the clay particles in suspension. Furthermore, the addition of fatty acid (or its salt) not only increases the physical stability depending on the amounts, proportions and types of the physical stabilizers and clay thickeners, but also ensures a simultaneous increase in the apparent viscosity. Ratios of fatty acid (salt) to clay thickener in the range of about 0.08 to 0.4% by weight clay thickener are generally sufficient to ensure these simultaneous benefits, and therefore the use of these ingredients is in them Ratios most preferred.

In general, LADD effectiveness is directly dependent on (a) the amount of chlorine available, (b) the alkalinity, (c) the solubility in the rinsing medium and (d) the foam inhibition. It is preferred according to the invention that the pH of the LADD composition is at least about 9.5, preferably about 10.5 to 13.5 and most preferably at least about 11.5. At relatively lower pH values, the LADD product is often too viscous, i.e. solids-like, and it is not rapidly liquefied under the shear forces generated within the dispenser under normal machine operating conditions. As a result, the composition loses much, if not all, of its viscoelastic character. The addition of NaOH is often necessary to raise the pH to within the above ranges and to improve the fluidity properties. According to the invention, the presence of carbonate is also often necessary because it acts as a buffer which helps to maintain the desired pH. Excess carbonate should be avoided, however, because it can cause the formation of needle-like crystals from carbonate, which adversely affects the stability, the thixotropy and / or the cleaning action of the LADD product, as well as the ability to squeeze the product out of, for example, a tube or squeeze bottle - be flowed. Caustic soda (NaOH) also serves the function of neutralizing the phosphoric acid or phosphonic acid reester foam reducer, if it is present. About 0.5 to 3% by weight NaOH and about 2 to 9% by weight sodium carbonate are typical in the LADD composition, although it should be noted that sufficient alkalinity is often ensured by the alkali metal silicate.

The amount of water contained in these compositions should of course not be so great as to produce inappropriately low viscosity and fluidity, nor should it be so small as to produce inappropriately high viscosity and low fluidity, thereby reducing the viscoelastic properties both cases are reduced or destroyed. This amount can easily be determined in each individual case by routine experiments, whereby it is generally from all sources in general

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NEN is in the range of about 25 to 75% by weight, preferably about 55 to 65% by weight. The water should also preferably be deionized or plasticized.

Other conventional ingredients can be incorporated into these compositions in small amounts, generally less than about 3% by weight, such as perfume, hydrotropes such as sodium benzene, toluene, xylene and cumene sulfonates, preservatives , Dyes and pigments and the like, all of which, of course, must be stable to the bleaching compound and high alkalinity (properties of all components). The chlorinated phthalocya-nine and polysulfides of aluminosilicates, which provide appealing green and blue shades, are particularly preferred for coloring. TÌO2 can be used as a whitening agent and to neutralize false colors. Abrasives and abrasives should be avoided in the LADD compositions as they can damage the surface of fine dishes, crystals and the like.

According to a preferred process for the preparation of these compositions, all inorganic salts, e.g. Carbonate (if used), silicate and zeolite in the aqueous medium. The thickening ingredients including the carboxyl group-containing polymer and clay (if any) are added last. The foam reducer (if used) and the thickener are initially provided as an aqueous dispersion. The foam-reducing dispersion, the caustic soda (if used) and the inorganic salts are first mixed at elevated temperatures in aqueous solution (deionized water) and then cooled, with constant agitation. The bleach, the surfactant, the fatty acid salt stabilizer or its salt, the polymer and the thickener dispersion are then added to the cooled (25 to 35 ° C.) solution at room temperature. Exclusively the chlorine bleach compound, the total salt concentration (e.g. sodium silicate and carbonate) is generally about 20 to 50% by weight, preferably about 25 to 40% by weight of the composition.

Another very preferred method for mixing the constituents of the LADD formulations is that a mixture of water, foam suppressant, surfactant, carboxyl-containing polymer, fatty acid or its salt and clay is first produced. These ingredients are mixed together under high shear conditions, preferably starting at room temperature to form a uniform dispersion. In this premixed part, the remaining ingredients are introduced under low shear conditions. For example, the required amount of the premix is introduced into a low shear mixer, and then the remaining ingredients are added with mixing either sequentially or simultaneously, preferably the ingredients are added sequentially , although it is not necessary to stop adding the total amount of one ingredient before starting to add the next ingredient. Furthermore, one or more of the ingredients can be divided into portions and added at different times. Good results are obtained by adding the other ingredients in the following order: sodium hydroxide, alkali metal carbonate, sodium silicate, aluminosilicate zeolite, bleach (preferably sodium hypochlorite) and sodium hydroxide.

The aqueous ADD compositions according to the invention can easily be used in a known manner for washing dishes, other kitchen objects and the like in an automatic dishwasher equipped with a suitable detergent dispenser compartment in an aqueous rinsing bath which contains an effective amount of the composition.

Although the invention has been described in particular in connection with its application to liquid automatic dishwashing detergents, it is self-evident to the person skilled in the art that, with or without the advantages of viscoelasticity and physical stability, with the additional amounts of alkali metal silicate and through the interaction of the clay and the fatty acid are obtained, the cleaning advantages which are guaranteed by the combination of bleach-stable surfactant, bleaching agent and zeolite builder and bleaching-stable, water-soluble polymer containing carboxyl groups, the compositions according to the invention as a general type of one make liquid detergent composition useful for dishes, glassware, cutlery, pots, pans and the like.

As for the removal of a wide range of food stains, the cleaning behavior of the composition according to the invention is comparable to or slightly better than that of similar alkali metal polyphosphate, e.g. Detergents containing sodium tripolyphosphate builder. For example, cleaning tests with various food residues, including egg, peanut butter, tea, coffee, milk, cocoa, tomato juice, rice, rice-cheese mixture, white sauce, oatmeal and spinach, some of which were stuck, were carried out with the inventive LADD composition achieved slightly better cleaning or the same cleaning for 14 to 16 food stains on different substrates (glasses, cups, cutlery, bowls, pots), and only slightly less cleaning for cocoa and baked rice on pots.

As shown in the following example, the compositions of the present invention are generally superior to similar compositions containing phosphate builders in terms of staining and fog.

The invention can be practiced in various ways, and a number of certain embodiments have been described to illustrate the invention with reference to the accompanying example.

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All amounts and proportions stated in the description, the example and the claims relate to the weight of the composition, unless stated otherwise.

example

The following two compositions were prepared to compare the properties of the composition of the invention with that of a similar composition containing phosphate builders.

component

invention

Comparative example

Trial No. 1

Trial No. 2

Water, deionized

16.44

30.44

Stearic acid

0.10

0.10

smectic clay (Van Gel ES)

1.50

1.50 •

Sodium silicate (47.5% by weight solution with a

35.00

25.00

Na2S04: SiQ2 ratio of 1: 2.4

Sodium tripolyphosphate (essentially anhydrous,

-

12.00

i.e. about 3% moisture)

Sodium tripolyphosphate hexahydrate

-

12.00

Alumosilicate zeolite

24.00

-

Sodium carbonate, anhydrous

6.00

6.00

Sodium hypochlorite (1% available chlorine)

9.00

9.00

Surfactant (Dowfax 3B-2, (45% by weight aqueous solution

0.80

0.80

of Na mono- and di-decyl disulfonate)

Antifoam (Knapsack LPKn 158, mixture of

0.16

0.16

Mono- and disteary! - (Ci6-Ci 8) alkyl esters of phosphorus

acid, molar ratio about 1: 1.3)

Caustic soda solution (50% by weight NaOH)

3.00

3.00

Sodium polyacrylate (MW = 4500.46% by weight solution)

4.00

-

100.00

100.00

Each of the formulations of Experiments Nos. 1 and 2 was tested to compare cleaning performance (staining and fog on glassware) using a Kenmore dishwasher with 100g glassware using tap water at a temperature of 54 ° C (130 ° F ) and 120 ppm hardness was used. The test procedure is described in ASTM D3566-79, with the difference that only four cleaning cycles were used. The haze and stain formation was rated on the following scales:

Rating wet scale for fog formation

1. excellent, no discernible veil

2. weak fogging, is just recognizable

3. noticeable veil, increasing

4. Further increase in the clear veil

5. Fog formation becomes excessive

6. strong fog, excessive deposition

7. Further increase in excessive veil.

Rating wet scale for stains

A. excellent - no stains

B. very few recognizable spots

C. clearly

D. substantial coverage approximately 50%. The results are shown below:

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Assessment of behavior

Test No.

Stain trial 1

Trial 2

Veil attempt 1

Trial 2

1

FROM

B

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B-C

2nd

2nd

Similar results to those described above are obtained when the polyacrylate is replaced by a methacrylic acid / maleic anhydride copolymer, e.g. Sokolan CP5, is replaced.

Claims (1)

Claims 1. An aqueous detergent composition containing little or no phosphorus, which contains water-stable organic surfactant, chlorine bleach, water-dispersible, alkali metal silicate, chlorine bleach and detergent builder, characterized in that the detergent builder contains a mixture of an aluminosilicate zeolite and a carboxyl group-containing, water-soluble Bleaching agent comprises stable polymer or its salts. 2. Composition according to claim 1, characterized in that the bleach-stable polymer is a polyacrylic acid or polyacrylate polymer which has a molecular weight in the range from 1000 to 25,000. 3. Composition according to claim 2, characterized in that the bleach-stable polymer has a molecular weight of 2000 to 10,000. 4. The composition according to claim 1, characterized in that the detergent builder, based on the composition, comprises 5 to 35% by weight of the aluminosilicate zeolite and 0.5 to 10% by weight of the polymer which is stable against bleaching agents. 5. A composition according to claim 1, characterized in that it further comprises an inorganic, clay-thickening agent which forms a koiloid. 6 »Composition according to claim 5, characterized in that it further comprises an aliphatic C8-C22 carboxylic acid or its salt. 7. The composition according to claim 1, characterized in that it further comprises a foam reducer stable against bleach. 8. The composition according to claim 7, characterized in that the foam reducer comprises one to two Ci2-C2o-Aikylgruppen containing acidic alkyl phosphate ester or an alkyl phosphate or a mixture thereof. 9 «Composition according to claim 1, characterized in that it is free of phosphorus. 10. The composition according to claim 9, characterized in that it further comprises a silicone display m reducer. 11. An aqueous, thickened, liquid automatic dishwasher detergent composition according to claim 1, which contains not more than 0.01% by weight of phosphorus, characterized in that it (a) 5 to 35% by weight of aluminosilicate zeolite, (b) more than 25% by weight sodium silicate, (c) 0 to 9% by weight of alkali metal carbonate, (d) 0.1 to 5% by weight of a bleaching agent-stable, water-dispersible, organic, cleaning-active material, (e) 0 to 5% by weight of a foam reducer which is stable to bleach, (f) a chlorine bleach compound in an amount which provides 0.2 to 4% by weight of available chlorine, (g) 0 to 3% by weight of an inorganic, colloid-forming clay thickener, (h) 0 to 0.5% by weight of an aliphatic fatty acid with 8 to 22 carbon atoms or of their dimers, trimers or metal salts, (i) 0 to 8% by weight sodium hydroxide, (j) 0.5 to 10% by weight of a water-soluble polymer containing carboxyl groups or salts thereof which are stable against bleaching agents and (k) water, the composition having a pH of at least 9.5. 12. The composition according to claim 11, characterized in that the bleach-stable polymer is polyacrylic acid or polyacrylate and has a molecular weight of 1000 to 25,000. 13. The composition according to claim 12, characterized in that the polymer which is stable against bleaching agents has a molecular weight of 2,000 to 10,000. 14. The composition according to claim 11, characterized in that it contains 0.03 to 0.5 wt .-% of the aliphatic fatty acid or salt (h) and 0.1 to 3 wt .-% of the clay thickener (g) . 12 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 CH 677 930 A5 Composition according to claim 14, characterized in that the fatty acid, stearic acid or its metal salt is and the clay is a smectic or an attack clay. 16. The composition according to claim 11, characterized in that the chlorine bleach compound (f) is sodium hypochlorite. 17. The composition according to claim 11, characterized in that it contains at least 0.1 wt .-% of the foam reducer (s). 18. The composition according to claim 17, characterized in that the foam reducer is one to two Ct2-C2o-alkyl groups containing acidic alkyl phosphate ester or an alkylphosphonic acid ester or a mixture thereof. 19. The composition according to claim 11, characterized in that it has a pH of 10.5 to 13.5. 20. Commercial process for washing dirty dishes in an automatic dishwasher, characterized in that the dirty dishes in an automatic dishwasher are brought into contact with an aqueous washing bath in which an effective amount of the composition according to claim 11 is dispersed. 13