CH676006A5 - - Google Patents

Description

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description

The invention relates to a dishwashing liquid containing water and builder, which also contains an enzyme. To stabilize the enzyme, the dishwashing detergent according to the invention contains a boron compound, a carboxylic acid, preferably an a-hydroxycarboxylic acid, and a protein-containing material. The invention relates in particular to water-containing liquid thixotropic clay compositions as dishwashing detergents which have a stabilized enzyme system which contains a boron compound, e.g. Borax, an alpha-hydroxycarboxylic acid, e.g. Lactic acid, tartaric acid and citric acid, casein and an enzyme, e.g. contains proteolytic and amylolytic enzymes. Above all, the invention relates to detergents for dishwashing machines which contain a stabilized enzyme system, have enzyme stability and physical stability and are easily dispersible in the washing medium, ensuring effective cleaning of dishes, glassware, porcelain and the like.

The currently available builder-containing powdery and aqueous dishwashing detergents, including thixotropic dishwashing detergents, do not contain stabilized enzyme systems.

The water-containing liquid dishwashing detergent according to the invention is therefore characterized in that it contains a stabilized enzyme system, the dishwashing detergent

- Water

- an alkali phosphate builder salt,

- organic surfactant,

- a boron compound,

- a carboxylic acid,

- a proteinaceous material and

- has an enzyme.

The agent according to the invention is particularly suitable for use in dishwashers for cleaning dishes, glassware, porcelain, kitchen utensils and the like. The agent according to the invention is very stable.

Dishwashing detergents for automatic dishwashers (also referred to here as ADD) generally contain (1) sodium tripolyphosphate (NaTPP) for softening or binding hardness-forming minerals and for emulsifying and / or peptizing dirt; (2) sodium silicate to achieve the necessary alkalinity for effective cleaning and protection for porcelain glaze and decor; (3) optionally sodium carbonate to increase alkalinity; (4) a chlorine-releasing agent for better removal of dirt stains and water marks as well as dirt such as tea and coffee stains; and (5) foam depressant / surfactant for reducing the foam with a concomitant improvement in the efficiency of the dishwasher and for improving or supplementing the washing power. (See, for example, SDA Detergents in Depth, “Formulations Aspects of Machine Dishwashing”, Thomas Oberle (1974).) Detergents, dishwashing detergents or detergents corresponding to the above composition are mostly liquid or powdery.

However, the use of a chlorine-releasing agent has been found to be disadvantageous in some dishwashing compositions because the chlorine-releasing agent easily reacts with other chemically active ingredients, particularly surfactant (see U.S. Patent 4,115,308), degrading the suspending or thixotropic substance and damaging its effectiveness becomes. It is a feature of the invention that a chlorine-releasing compound is not required in the dishwashing detergent.

The formulation of a stabilized, liquid, enzyme-containing dishwashing detergent posed a major problem. The desire to incorporate enzymes in dishwashing detergent is based on the fact that proteolytic and amylolytic enzymes effectively break down protein and starch materials on dirty dishes and kitchen appliances, thereby removing them Ease leftovers such as dripping fat, eggs, tomato sauce, chocolate and the like when cleaning in an automatic dishwasher. However, enzymatic substances that are suitable for dishwashing detergents, especially proteolytic enzymes, are quite expensive. In addition, it is known that enzymes in aqueous builder-containing laundry detergents are not stable.

Of liquid laundry detergents containing phosphate builders, the problem of enzyme instability is known to be particularly acute. It is based primarily on the destabilizing effect of phosphate builders on enzymes. In addition, the incorporation of a phosphate builder into a liquid dishwashing liquid poses an additional problem, namely to form a stable single-phase composition; however, the solubility of sodium tripolyphosphate, for example in aqueous compositions and especially in the presence of anionic surfactants, is relatively limited.

The stabilization of enzymes in detergents of high alkalinity is also difficult because it is known that high alkalinity deactivates enzymes. While it is possible to lower the pH to improve enzyme stability, it will to some extent negate the beneficial effects of builders. The stabilized enzyme system of the invention ensures enzyme stability even at relatively high pH values, up to pH values from 10 to 12. The higher pH values, e.g. pH values from 10 to 12 ensure better cleaning power and are therefore preferred. Lowering the pH of the detergent to a pH of 7.5 to 9.5, for example, can reduce enzyme stability

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increase, however, reduces the duration of action of the washing liquors (suds life) and the beneficial effects of the builders, namely the cleaning power.

U.S. Patent 4,431,559 discloses an automatic dishwasher thixotropic composition containing an aqueous solvent, a thickener, a chlorine source, an anionic surfactant, builder salts and a buffer system for stabilizing the chlorine-providing compound.

U.S. Patent 3,558,498 discloses a granular laundry detergent containing stabilized enzymes, sodium perborate trihydrate, anhydrous trisodium phosphate, anhydrous calcium sulfate and soluble or dispersible proteins with a MW of 5,000 to 1,000,000, e.g. Casein, which has a MG of 50,000 to 200,000.

U.S. Patent 3,560,392 (CINP 3,558,498) describes a granulated laundry detergent containing an organic surfactant, alkali metal salt, a stabilized enzyme and a stabilizing amount of proteinaceous collagen with a MW of 5,000 to 250,000.

U.S. Patent 4,238,375 discloses a liquid laundry detergent in which the enzyme is stabilized by adding an antioxidant and a hydrophilic polyol having 2 to 6 hydroxyl groups. In column 1, the patentee states that calcium salts in combination with proteins and glycerin in combination with proteins were used to create enzyme-stabilizing systems in aqueous textile liquid detergents.

GB patent application 2,079,305 describes a water and builder-containing liquid textile detergent with an enzyme in which the enzyme is stabilized by a mixture of polyol and boric acid.

USSN 925 437 describes builder-containing aqueous textile liquid detergents with an enzyme-stabilizing system which consists of a boron compound, an alpha-hydroxycarboxylic acid, casein and an enzyme.

USSN 903 924 describes a thixotropic water-containing clay composition as a dishwashing detergent, which contains aluminum stearate as a physical stabilizing agent.

The stabilized enzyme system contained in the dishwashing detergent according to the invention consists of the enzyme itself and a boron compound, a carboxylic acid, preferably an alpha-hydroxycarboxylic acid and a proteinaceous material such as e.g. Casein.

In a preferred embodiment, the enzyme stabilization can be achieved by mixing a mixture which contains alpha-hydroxycarboxylic acid and the boron compound with a mixture containing enzyme and casein such that the catalytic sites of the enzyme are blocked with casein and the enzyme structure with the Mixture of boron compound and alpha-hydroxycarboxylic acid is blocked.

In addition to very good protease stabilization, the enzyme-stabilizing system contained in the agent according to the invention shows very good amylase stabilization and thus enables the use of dual protease and amylase-stabilized systems in strongly alkaline detergents.

The effective stabilization of the enzyme activity of amylase is surprising since one would expect that at a pH above 9 any amylase activity would be destroyed.

The aqueous liquid dishwashing detergents of the invention can clean dishes and kitchen utensils from both oily and particulate food residues. In addition, the compositions described can be used to soak heavily soiled dishes that are to be washed in an automatic dishwasher.

The stabilizing enzyme system consisting of a boron compound, a carboxylic acid such as an alpha-hydroxycarboxylic acid, a proteinaceous material such as casein and an enzyme has an effective and efficient enzyme-stabilizing effect on the water-containing liquid dishwashing detergents.

According to one embodiment, the invention relates to a builder- and water-containing liquid dishwashing detergent which has an enzyme-stabilizing system and a suspension of a phosphate builder salt in the detergent containing the aqueous liquid anionic surfactant.

According to another embodiment, the invention relates to a water-based dishwashing liquid containing thixotropic clay, which comprises an enzyme-stabilizing system and a suspension of a phosphate builder salt in the aqueous detergent containing liquid anionic surfactant.

Namely, it has been found that a stabilizing enzyme system which ensures a mixture of a boron compound, a carboxylic acid such as an alpha-hydroxycarboxylic acid, a proteinaceous material such as casein and an enzyme has an effective enzyme activity in aqueous liquid dishwashing detergents for relatively long periods of time.

The dishwashing detergents of the invention are physically stable compositions. The aqueous liquid detergent of the invention is easy to pour, easy to measure and easy to put in an automatic dishwasher.

There is a need for a water-based dishwashing liquid or a water-containing liquid thixotropic clay which contains a stabilized enzyme system and optionally a physical stabilizer.

It is therefore an object of the invention to provide a water-containing liquid dishwashing detergent which contains a stabilized enzyme system.

It is a further object of the invention to provide an aqueous, liquid, thixotropic, clay-containing dishwashing detergent which contains a stabilized enzyme system.

In a preferred embodiment, a stabilized enzyme system containing a boron

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Binding, an alpha-hydroxycarboxylic acid, casein and an enzyme, for addition to water-containing liquid and water-containing liquid thixotropic dishwashing detergent to provide the dishwashing detergent with an effective proteolytic and / or amylolytic enzyme cleaning action.

Yet another object of the invention is to improve the physical stability of water-containing, liquid, stabilized enzyme systems containing dishwashing detergents in the form of thixotropic gels by incorporating a small but effective amount of a fatty acid metal salt as a physical stabilizing agent into a dishwashing detergent containing thixotropic clay, for example Aluminum stearate to prevent suspended particles from settling and phase separation.

To produce a preferred agent, it is proposed to incorporate a stabilized enzyme system into an aqueous thixotropic, for example normally gel-like, composition. In order to improve the physical stability of the dishwashing detergent, a small but effective amount of a physical stabilizer, for example a fatty acid or a metal salt thereof, can be added to the composition. In particular, according to a preferred embodiment of the invention, a normally gel-like dishwashing detergent for automatic dishwashers is proposed, in which a stabilized enzyme system containing a boron compound, an alpha-hydroxycarboxylic acid, casein and an enzyme and a physically stabilizing amount of a metal salt of a long-chain fatty acid, which settles suspended particles inhibited, incorporated.

Compared to known dishwashing detergents, the invention has the advantage that it makes available an dishwashing detergent containing aqueous liquid phosphate builder which has a relatively simple stabilized enzyme system which contains a boron compound, a carboxylic acid, preferably an alpha-hydroxycarboxylic acid, a proteinaceous material such as casein and an enzyme . The enzyme-stabilizing system ensures that the active enzyme is stabilized over a relatively long period of time, so that the expensive enzymes can be used in small amounts.

The invention provides an aqueous dishwashing liquid containing phosphate builder with an organic surfactant that has a stabilized enzyme that can be used at effectively high pH values of 10 to 12. The invention also provides an effective and efficient dishwashing detergent that does not require the use of a chlorine compound.

Another water-containing liquid dishwashing detergent is also characterized by a content of a stabilized enzyme system, the detergent

35 to 65% by weight of water,

-8 to 35% by weight of alkali phosphate builder salt,

0 to 20% by weight sodium silicate,

0 to 5% by weight of organic surfactant,

0.4 to 2% by weight of boron compound,

-1 to 5% by weight carboxylic acid,

-1 to 6% by weight of proteinaceous material,

- Contains 0.5 to 6% by weight of enzyme.

According to a preferred embodiment of this dishwashing detergent, a normally gel-like, aqueous detergent with thixotropic properties for automatic dishwashers is proposed, containing, based on the weight:

(a) 8 to 35% alkali tripolyphosphates;

(b) 0 to 20%, for example 2.5 to 20% sodium silicate;

(c) 0 to 9% alkali carbonate,

(d) 0 to 5%, for example 0.1 to 5%, water-dispersible organic detergent material:

(e) thixotropic clay as a thickener in an amount sufficient to give the composition a thixotropic index of 0 to 10.0, e.g. to confer about 2.5 to 10;

(f) 0.5 to 2.0% boron compound;

(g) 1.5 to 4.0% alpha-hydroxycarboxylic acid;

(h) 1 to 4.0% casein;

(i) 0.5 to 2.0% enzyme;

© 0 to 5% foam presser;

(k) 0 to 8% sodium hydroxide;

(I) 0 to 2% of a metal salt of a long chain fatty acid; and (m) water as the rest.

The invention also provides a commercial process for cleaning dishes in an automatic dishwasher with an aqueous wash bath which contains an effective amount of the above-described liquid dishwashing detergent (LADD) for automatic dishwashers. According to this aspect of the invention, the dishwashing detergent can be easily poured into the dispenser compartment of the dishwasher and promptly thickens to its normally gel-like or pasty state within just a few seconds, in which it remains firmly in the dispenser compartment until shear forces such as water spray again act on it the dishwasher.

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In the agents according to the invention, the enzyme activity is stabilized over a relatively long period of time in such a way that smaller amounts of the enzyme develop an effective enzyme cleaning activity. The activity of the enzyme is stabilized by adding small but effective amounts of a stabilized enzyme system which contains a boron compound, a carboxylic acid such as an alpha-hydroxycarboxylic acid, a proteinaceous material such as casein and an enzyme. The stabilized enzyme system is used in aqueous detergents containing phosphate builders and anionic surfactants.

The stabilized enzyme system is preferably prepared separately and then added to the dishwashing detergent.

The stabilized enzyme system is preferably made in a three step process as described below.

1. A boron compound is added to an alpha-hydroxycarboxylic acid or a salt thereof to obtain a first mixture.

2. Protein-like material, e.g. Casein, to an aqueous alkali solution and adds the enzyme to the aqueous alkali solution to obtain a second mixture.

3. Then mix the boron and alpha-hydroxycarboxylic acid mixture from stage 1 with the mixture of proteinaceous material and enzyme obtained in stage 2 to obtain the premix, namely the stabilized enzyme system of the invention.

The stage 1 mixture and the stage 2 mixture can each be added to the dishwashing detergent separately. However, the best enzyme stabilizing results are obtained by premixing the mixtures from stages 1 and 2 and then adding the premixed mixture to the dishwashing detergent.

Without wishing to be bound by any theory as to how the stabilized enzyme system works, it is believed that the boron compound reacts with the alpha-hydroxycarboxylic acid or with the alpha-hydroxypolycarboxylic acid to form a boric acid ester. The boric acid ester probably reacts with the enzyme and blocks its structure in the active form (conformation), so that it is protected against denaturation. The proteinaceous material presumably blocks the catalytic sites of the enzyme and thereby prevents the breakdown (digestion) of further enzyme molecules during the storage of the product.

The stabilized enzyme system contains:

Boron compound, e.g. Borax, in an amount of 0.4 to 2.5, preferably 0.75 to 2.0, and particularly preferably 0.9 to 1.2 parts by weight.

Alpha-hydroxycarboxylic acid in an amount of 1 to 5, preferably 1.5 to 4.0, and particularly preferably 1.8 to 3.6 parts by weight.

Protein-like material, e.g. Casein, in an amount of 1 to 6.0, preferably 1 to 4.0, e.g. about 1.0 to 2.0 parts by weight.

Enzyme in an amount of 0.5 to 3.0, preferably 0.5 to 2.0 and particularly preferably 0.5 to 1.0 parts by weight.

The weight ratio of alpha-hydroxycarboxylic acid to boron compound can be 7: 1 to 1: 1, preferably 4: 1 to 1: 1 and particularly preferably 3: 1 to 2: 1.

The weight ratio of proteinaceous material, e.g. Casein to enzyme can be 8: 1 to 1: 1, preferably 4: 1 to 1: 1 and particularly preferably 4: 1 to 2: 1.

A particularly preferred enzyme system comprises the following components in the amounts indicated:

The stabilized enzyme system can the dishwashing detergent in an amount of 10 to 30 parts by weight of the stabilized system 90 to 70 parts by weight of detergent, preferably 15 to 25 parts of the stabilized system 85 to 75 parts by weight of dishwashing detergent and particularly preferably 15 to 20 parts of the stabilized system 85 to 80 parts by weight Dishwashing detergent can be added. The stabilized enzyme system is added to the dishwashing detergent in such a way that the percentages by weight of active components of the enzyme system in the dishwashing detergent correspond to the parts by weight of the active ingredients in the stabilized enzyme system given above.

The stabilized enzyme system is described in detail in the above-mentioned USSN 925 437.

Parts by weight

Borax (Na2B4Û7. IOH2O)

alpha-hydroxycarboxylic acid

Casein

enzyme

0.75 to 2.0 1.5 to 4.0 1.0 to 4.0 0.5 to 2.0

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The stabilized enzyme system can be used in aqueous liquid dishwashing detergents, aqueous liquid thixotropic dishwashing detergents and in powdered or granulated dishwashing detergents.

According to a preferred embodiment of the invention, the stabilized enzyme systems are added to aqueous liquid thixotropic dishwashing detergents.

The alpha-hydroxycarboxylic acids that can preferably be used are the organic carboxylic acids with 3 to 8 carbon atoms, which have 1 to 3 carboxylic acid groups and 1 to 3 hydroxy groups.

The preferred carboxylic acids are the alpha-hydroxy carboxylic acids with 3 to 6 carbon atoms, which have 1 to 3 carboxylic acid groups and 2 hydroxyl groups. Suitable alpha-hydroxycarboxylic acids are, for example, maleic acid (HOOCCHOHCHaCOOH),

Tartaric acid (HOOCCHOHCHOHCOOH),

Lactic acid (HOOCCHOHCH3), and citric acid (HOOCCH2C (OH) COOHCH2COOH).

The preferred alpha-hydroxycarboxylic acids are tartaric acid, lactic acid and citric acid. Citric acid is most preferred. The alpha-hydroxycarboxylic acids can be used per se or as alkali salts, for example as sodium and potassium salts.

The boron compounds which can be used in the dishwashing detergents of the invention are those which are water-soluble and form boric acid or an alkali salt of boric acid when added to water. Applicable boron compounds are, for example, boric acid, boron oxide or an alkali borate. Suitable alkali borates are sodium and potassium ortho-, pyro- and metaborates, polyborates and borax (Na2B4Û7. IOH2O). The preferred boron compounds are boric acid, sodium borate (NasBCh) and borax (Na2B407. IOH2O).

The enzymes that can be incorporated into the dishwashing detergents of the invention can be proteolytic or amylolytic enzymes or mixtures thereof. Suitable proteolytic enzymes for the invention are the various commercially available liquid, powdered or slurry-like enzyme preparations which have been prepared for use in detergent compositions.

While it is highly convenient to incorporate the enzyme into the composition in liquid form, the slurry or slurry-form enzymes have proven useful. Suitable liquid enzyme preparations are, for example, "Alcalase" and "Esperase", which are sold by Novo Industries, Copenhagen, Denmark, "Maxatase" and "Maxacal" by Gist-Brocades, Delft, The Netherlands and "Optimase" by Miles, Kali Chemie. Suitable proteolytic enzymes are, for example, subtilisin, bromelin, papain, trypsin and pepsin. Suitable enzymes include liquid protease and liquid amylase. The enzymes are preferably used in the form of their solutions. A preferred enzyme is Esperase 8L in the form of a solution. Suitable liquid aipha amylase enzyme preparations are those sold by Novo Industries and Gist-Brocades under the trade names "Termamyl" and "Maxamyl", respectively. A preferred enzyme is Termamyl 120L. “Esperase” 8L is preferred for the compositions according to the invention because of its activity at the higher pH values of the detergent containing builder. Another preferred enzyme is Esperase 8.0L because of its high activity at 60 ° C and its low activity at room temperature. In addition, Esperase 8.0L is stable at a high pH and thus enables a higher pH of the finished product and better cleaning power.

One of the constituents stabilizing the enzyme material in the agents according to the invention is a proteinaceous material, for example casein. The proteinaceous materials are preferably used in the form of their water-soluble alkali salts (e.g. sodium and potassium salts) and / or dispersed in an aqueous medium to which the enzyme is added.

Proteins that are soluble or dispersible in water can be used in an amount effective to stabilize the enzymes. Examples of water-soluble or dispersible and suitable proteins are casein (average MW 50,000 to 200,000); Wilson's Protein WSP-X-1000 (a solubilized collagen with an average MW of about 10,000) and Wilson's Hydrolyzate Cosmetic 50, both sold by Wilson's Pharmaceutical & Chemical Company; and Collagen Hydrolyzate Cosmetic 50, sold by Maybrook, Inc. A preferred casein protein is sold under the trade name “Sodium Caseinate” by Bridai (France) or Dena, A.G. (Germany) sold. The sodium caseinate is a mixture of different caseins with different molecular weights. The proteins, for example casein, are mostly available as powder. Proteins like casein exist as long chemical chains. As a powder, the chains are placed on top of one another and form hydrogen bonds that hold the protein in a spherical shape. Unraveling or developing or denaturing the protein involves breaking these hydrogen bonds, forming a looser, more arbitrary structure. The proteins can be denatured by boiling, using acids, alkalis and various detergents. The fibrillated or developed or denatured proteins are more easily broken down or digested by the enzymes and thus ensure a better stabilizing effect, i.e. they guarantee one

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better enzyme stability. Denaturation makes the protein more effective as a stabilizer. The protein, e.g. Casein is used in an amount sufficient to stabilize enzyme activity.

With regard to preferred dishwashing detergents, the effectiveness of the thixotropic aqueous clay composition generally depends on (a) alkalinity, (b) solubility in the washing medium and (c) foam inhibition. It is preferred that the pH of the dishwashing detergent composition be at least about 9.5, more preferably about 10.5 to 12.5, and most preferably at least 11.5. At the relatively lower pH values, the dishwashing detergent is too viscous, i.e. similar to solids, and is therefore not readily fluidized in the shear forces prevailing in the dispensing compartment under normal operating conditions of the machine. In short, the composition loses much if not all of the thixotropic properties. Therefore, the addition of NaOH is often required to raise the pH to be within the ranges given above and to improve the fluidity properties. According to the invention, the presence of carbonate is also often required, since it acts as a buffer and helps to maintain the desired pH. Excess carbonate should be avoided, however, since it can cause the formation of needle-like carbonate crystals and thereby impair the stability, thixotropy and / or washing power of the dishwashing detergent (LADD) and the dispensability of the product, for example from squeeze tubes or squeeze bottles. Caustic soda (NaOH) has the further function of neutralizing the possibly present foam damper, phosphoric acid or phosphonic acid ester. Usually about 0.5 to 3% by weight of NaOH and about 2 to 9% by weight of sodium carbonate are used in the dishwashing detergent (LADD), although it should be noted that sufficient alkalinity can be ensured by the NaTPP and sodium silicate. The sodium silicate can be present in amounts of approximately 0 to 20% by weight, preferably 2.5 to 20% by weight and particularly preferably 5 to 15% by weight.

The NaTPP can be used in the dishwashing detergent (LADD) in an amount in the range of 8 to 35% by weight, preferably 20 to 30% by weight. The NaTPP can be anhydrous or hydrated and in the form of the stable hexahydrate with a degree of hydration of 6, corresponding to about 18% by weight of water or more. With regard to the stability of the hexahydrate, the presence of some water of hydration is even extremely effective, since it presumably forms nuclei of the stable hexahydrate, which accelerates the hydration and solubilization of the remaining NaTPP particles. If only the hexahydrate is used, the detergent product may be too liquid and have little, if any, thixotropic properties. Conversely, if only the anhydrous NaTPP is used, the product can be too thick in certain cases and therefore unsuitable. Particularly preferred detergent products are obtained, for example, if a weight ratio of anhydrous to hexahydrated NaTPP of 0.5: 1 to 2: 1 is used, values of about 1: 1 being particularly preferred.

Foam inhibition is important in order to increase the efficiency of the dishwasher and to minimize the destabilizing effects that can occur in the presence of excess foam during use of the dishwasher. The foam can be reduced by choosing suitable surfactants and / or their amount, since these are the main foam-forming component. The extent of foaming is also somewhat dependent on the hardness of the washing water in the machine, but a suitable setting of the proportions of NaTPP, which has a water-softening effect, can help to achieve the desired level of foam inhibition. It is best to install a foam damper or inhibitor if a low-foam dishwashing detergent (LADD) is desired. The alkylphosphonic acid esters of the formula are particularly effective

0 II

HO-P -R

1

OR

which are available, for example, from BASF-Wyandotte (PCUK-PAE), and in particular the acidic alkyl phosphate esters of the formula

O

II

HO - P - OR!

OR

which can be obtained, for example, from Hooker (SAP) and Knapsack (LPKn-158), one of which

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or both R groups in each ester type can independently represent a C12 to C2o alkyl group. Mixtures of the two types or mixtures of mono- and diesters of the same type can be used. A mixture of acidic mono- and di-Gi6- to cis-alkyl phosphate esters, such as acidic monostearyl / distearyl phosphates 1.2 / 1 (Knapsack), is particularly preferred. If foam suppressors are used, amounts of 0.1 to 5, preferably about 0.1 to 0.5% by weight in the composition are typical, the weight ratio of detergent component (d) to foam suppressor (j) generally being in the range from 10: 1 to 1: 1 and preferably about 4: 1 to 1: 1. Other defoaming agents that can be used are, for example, the known silicones.

The sodium silicate, which ensures alkalinity and protection of hard surfaces such as porcelain glaze and decor, is usually used in an amount of about 2.5 to 20, preferably about 5 to 15,% by weight in the composition. The sodium silicate is generally added in the form of an aqueous solution, preferably with a Na2: Si02 ratio of about 1: 2.2 to 1: 2.8. In this context, it should be noted that most of the other components of this composition, especially NaOH, foam suppressants and thixotropic thickeners, are also often added in the form of a previously prepared aqueous dispersion or solution.

The wash-active substances contained in the agent according to the invention are preferably the water-dispersible organic anionic, amine oxide, phosphine oxide, sulfoxide or betaine surfactants. The anionic surfactants are preferred. The surfactants, e.g. Anionic surfactants are preferably used in amounts of about 0.1 to 5, preferably about 0.3 to 2.0%. Particularly preferred surfactants are the linear or branched alkali mono- and / or di- (C8- to CuJ-alkyldiphenyloxide mono- and / or disulfates, which are commercially available as DOWFAX (Wz) 3B-2 and DOWFAX 2A-1. In general, tend the paraffin sulfonates to impair, if not destroy, the thixotropy and result in an impermissible increase in viscosity, which raises severe shear problems. In addition, the surfactants are said to be compatible with the other constituents of the composition. Other suitable surfactants are, for example, the primary alkyl sulfates, alkyl sulfonates, Alkylarylsulfonates and sec.-alkylsulfates, examples of which are sodium cio to cis alkyl sulfates such as sodium dodecyl sulfate and sodium tallow alcohol sulfate; sodium cio to cis alkane sulfonates such as sodium hexadecyl 1 sulfonate and sodium Ci2 to Ci8 alkyldenzenesulfonate sulfonates such as The corresponding potassium salts can also be used, examples of suitable alkyl sulfo Nates are the primary C10 to C18-AI-kyisulfonates (as sodium and potassium sulfonates), with the sodium Cio to Cis (primary, normal) alkyl sulfonate salt being preferred.

Other suitable surfactants or detergent substances are, for example, the amine oxide surfactants of the structure R2RIN-O, in which each R is a lower alkyl radical, e.g. Is methyl, and R 1 is a long-chain alkyl group having 8 to 22 carbon atoms, for example lauryl, myristyl, palmityl or cetyl. Instead of an amine oxide, a corresponding phosphine oxide surfactant R2R1P0 or sulfoxidten-sid RR1SO can be used. Betaine surfactants usually have the structure R2R1N-R'COO ", in which each R denotes a lower alkylene radical having 1 to 5 carbon atoms. Specific examples of these surfactants are lauryldimethylamine oxide, myristyldimethylamine oxide, the corresponding phosphine oxides and sulfoxides, and the corresponding betaines including dodecyldimethylammonium acetate, Tetradecyl diethylammonium pentanoate, hexadecyldimethylammonium hexanoate, etc. For reasons of biodegradability, the alkyl groups of these surfactants are said to be linear, and these compounds are preferred.

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

Thixotropic thickeners, for example thickening or suspending compounds which impart thixotropic properties to an aqueous medium, are well known; they can be organic or inorganic, water-soluble, water-dispersible or colloid-forming, as well as monomeric or polymeric and they should of course be stable in these compositions, e.g. resistant to strong alkalinity. Particularly preferred such substances include the inorganic colloid-forming clays of the smectite and / or attapulgite types. Thixotropic organic clay thickeners can also be used. In the known dishwashing detergents according to GB 2 116 199A and GB 2 140 450A, these materials were generally used in amounts of about 1.5 to 10, preferably 2 to 5% by weight in order to achieve the desired thixotropic properties and the Bingham plastic behavior to reach. In the preferred agent according to the invention, amounts of inorganic colloid-forming clays of the smectite and / or attapulgite types in the range from 0.25 to 5, preferably 0.50 to 4.0, particularly 1.0 to 3% are generally sufficient to achieve the desired to achieve thixotropic properties and the Bingham plastic behavior. Smaller amounts of thixotropic substance can be used in combination with the physical stabilizer, the fatty acid metal salt.

Smectite clays include montmorillonite (bentonite), hectorite, attapulgite, smectite, saponite and the like. Montmorillonite clays are preferred and are commercially available as Thixogel (Trade Mark) No. 1 and Gelwhite (Trade Mark) GP, H, etc. from Georgia Kaolin Company; available as ECCAGUM (Wz) GP, H, etc. from Luthern Clay Products. Attapulgite clays include materials that are commercially available under the name Attagel (Wz), e.g. Attagel 40, Attagel 50 and Attagel 150 are available from Engelhard Minerals and Chemicals Corporation. Mixtures of the smectite and attapulgite types in weight ratios of 4: 1 to 1: 5 are for the

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Purposes of the invention useful. Thickening or suspending agents of the above types are well known and are described, for example, in the above-mentioned US Pat. No. 3,985,668. Abrasives or polishes should not be used in dishwashing detergents (LADD) as they can damage the surface of fine dishes, crystals and the like.

The amount of water contained in these compositions should of course not be so large that inadmissibly low viscosity and high fluidity, nor so low that inadmissibly high viscosity and low flowability arise, the thixotropic properties being reduced or destroyed in any case. This amount is easily determined by routine experimentation in each individual case and is generally in the range from about 35 to 65, preferably about 40 to 55,% by weight. The water should also preferably be demineralized or softened.

Unless otherwise stated, the description of the dishwashing product generally corresponds to the compositions described in the above-mentioned GB patent applications 2 116 199A and 2 140 450A.

The products (LADD) of these earlier UK patent applications show improved theological properties as determined by testing product viscosity as a function of shear rate. The compositions showed higher viscosity at a low shear rate and lower viscosity at a high shear rate, with the data indicating effective fluidization and gelation well within the shear rates that occur within standard dishwashers. In practical terms, this means improved pouring and processing properties as well as less leakage from the machine's dispenser compartment compared to previous liquid or gel ADD products or products for automatic dishwashers. At shear rates corresponding to 3 revolutions and 30 revolutions per minute, the viscosities (Brookfield) were accordingly around 10,000 to 30,000 10 ~ 3 Pa.s and around 3,000 to 7,000 10-3 Pa.s what was at room temperature with an LVT Brookfield viscometer 3 minutes using a # 4 spindle. A shear rate of 7.4 sec-1 corresponds to approximately 3 spindle revolutions per minute. An approximately 10-fold increase in the shear rate results in a 3 to 9-fold reduction in viscosity. With previous gel-shaped dishwashing detergent products, the corresponding reduction in viscosity was only about twice. In addition, in these compositions the initial viscosity determined at about 3 revolutions per minute was only about 2500 to 2700 10 -3 Pa.s. With a gradual decrease in viscosity depending on a gradual increase in the shear rate, the applicant's earlier compositions thus show threshold fluidizations at lower shear rates and to a significantly greater extent. This behavior of the applicant's earlier dishwashing detergent was summarized in what is known as a thixotropy index (TI), which is the ratio of the apparent viscosity at 3 revolutions to that at 30 revolutions per minute. The previous compositions have a TI of 2 to 10. The dishwashing detergents tested showed a substantial and rapid return to the consistency of the previous resting state when shear was discontinued.

The above-mentioned USSN 903 924 was based on the fact that it was found that the physical stability (ie the resistance to phase separation, settling etc.) of the liquid aqueous dishwashing detergent according to GB patent applications 2 116 199A and 2 140 450 can be significantly improved without their theological properties are deteriorated (in some cases even positively influenced) by adding a small but effective amount of a metal salt of a long-chain fatty acid to the composition.

Regarding the improvement of the theological properties, it was found, for example, that at low shear rates, e.g. at about 3 spindle revolutions per minute, the apparent viscosities can often be increased 2 to 3 times if only 0.2% or less, for example 0.16%, of the fatty acid metal salt serving as stabilizer is incorporated. At the same time, the physical stability can be improved to such an extent that even after a long time, 12 weeks or longer, in temperature ranges from close to freezing to 40 ° C or more, the compositions containing the metal fatty acid salts as stabilizers do not show any visible phase separation subject to.

The preferred metal salts of long chain fatty acids are those described in said USSN 903 924. Suitable fatty acid metal salts are the metal salts of higher aliphatic fatty acids, which have about 8 to about 22 carbon atoms, more preferably about 10 to 20 carbon atoms and most preferably about 12 to 18 carbon atoms, including the carbon atom of the carboxyl group of the fatty acid. The aliphatic radical can be saturated or unsaturated, straight-chain or branched. Straight chain saturated fatty acids are preferred. Mixtures of fatty acids can be used, for example those of natural origin such as tallow fatty acid, coconut fatty acid, soy fatty acid etc. or synthetic fatty acids from industrial production processes.

Examples of fatty acids from which the polyvalent metal salts serving as stabilizers can be produced are 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 preferred metals are the multivalent metals such as magnesium, calcium, aluminum and zinc.

Many of these metal salts are commercially available. For example, the aluminum salts in the

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CH 676 006 A5

Triacid form available, e.g. Aluminum stearate as aluminum tristearate, AI (Ci7H3sCOO) 3. The mono acid salts, e.g. Aluminum monostearate, Al (OH) 2 (Ci7H3sCOO) and the diacid salts, e.g. Aiuminiumdistea-rat, Ai (OH) (Ci7H35COO) 2 and mixtures of two or three of the mono-, di- and tri-acid salts can be used for such metals as aluminum with valences of +3, mixtures of the mono- and diacid salts can be used for such metals how Zn can be used with valences of +2.

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.

Of course, detergents for automatic dishwashers are just like for other applications in which the composition according to the invention may come into contact with objects which are used for the handling, storage or presentation of foods or which come into contact with or consumed by humans or in some other way Animals, the use of fatty acids as a stabilizing agent because of their known low toxicity of particular advantage. Calcium stearate, i.e. Calcium distearate, magnesium stearate, i.e. Magnesium distearate is particularly preferred as a generally safe food additive.

The amount of fatty acid metal salt stabilizers to achieve the desired improvement in physical stability depends on factors such as the type of fatty acid salt, the type and amount of thixotropic substance, the detergent compound, inorganic salts, especially TPP, other components of detergents for dishwashing machines and the intended storage and shipping conditions.

In general, however, amounts of the fatty acid metal salts used as stabilizing agents in the range from about 0.2 to 2, preferably about 0.5 to 1.0, particularly preferably about 0.5 to 0.8% ensure the long-term stability and the lack of phase separation when standing or during shipping at both low and elevated temperatures as required for a commercial product.

Depending on the amounts, proportions and the type of physical stabilizers and thixotropic substances, the addition of the fatty acid metal salt not only increases the physical stability, but also increases the apparent viscosity at the same time. Ratios of fatty acid to thixotropic substance in the range of about 0.08 to 0.4% by weight of fatty acid to about 1.3 to 2.5% by weight of thixotropic agent are generally sufficient to achieve these simultaneous advantages, and therefore the use of these ingredients in these ratios is most preferred.

According to a preferred process for the preparation of these compositions, all inorganic salts, i.e. Dissolve or disperse carbonate (if used), silicate and tripolyphosphate in the aqueous medium. The thickener (if used) is added immediately before the stabilized enzyme system. The foam damper (if used) is prepared beforehand, as is the thickener, as an aqueous dispersion. The foam damper dispersion, caustic soda (if used) and inorganic salts are first mixed at elevated temperatures in aqueous solution (demineralized water) and then cooled, with continuous stirring. Then the surfactant, the fatty acid stabilizer and the thickener emulsion are added to the cooled (25-25 ° C) solution at room temperature. The stabilized enzyme system of the invention is added last. The total salt concentration (NaTPP, sodium silicate and carbonate) is generally about 20 to 50, preferably about 30 to 40% by weight of the composition. The stabilized enzyme system generally makes up about 15 to 25, preferably about 15 to 20 parts by weight of the composition.

Another preferred method for mixing the components of the detergents for automatic dishwashers is to first mix a mixture of water, foam suppressor (if used), surfactant, physical stabilizer such as e.g. Fatty acid (if used) and thixotropic agent such as e.g. Produces clay (if applied). To form a uniform dispersion, these ingredients are mixed together under high shear conditions, preferably starting at room temperature. The remaining constituents are added to this premixed portion under low-shear mixing conditions. For example, the required amount of the premix is introduced into a low-shear mixer and then the remaining constituents are added with mixing either in succession or simultaneously. Preferably, the ingredients are added sequentially, although it is not necessary to add one ingredient completely before starting to add the next ingredient. In addition, one or more components can be divided into portions and added at different times. Good results are obtained if the remaining ingredients are added in the following order: sodium hydroxide, alkali carbonate, sodium silicate, alkali tripolyphosphate (hydrated), alkali tripolyphosphate (anhydrous or up to 5% water), sodium hydroxide and finally the stabilized enzyme system.

Other conventional ingredients can be incorporated into these compositions in small amounts, usually less than about 3% by weight, e.g. Perfumes, hydrotropes such as sodium benzene, toluene, xylene and cu-molsulfonates, protective and preservative agents, dyes and pigments and the like, all of which must of course be stable under strongly alkaline conditions (properties of all components). The chlorinated phthalocyanines and polysulfides of aluminosili-

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kat, which each deliver appealing green and blue tints. TÌO2 can be used to whiten or neutralize strong stains.

The liquid detergents for automatic dishwashers of the invention are used in a simple and known manner for washing dishes, kitchen appliances and the like in an automatic dishwasher with a suitable detergent dispenser compartment in an aqueous washing bath which contains an effective amount of the composition.

The following examples are intended to illustrate the invention, all quantities and ratios being by weight, unless stated otherwise.

example 1

A stabilized enzyme system according to the invention was produced by the following method.

(1) 12.6 g of sodium borate (Na3B03) was added to 56.1 g of tartaric acid in 90 g of water with stirring. The mixture was neutralized to a pH of about 7 with 56.1 g NaOH (50% solution).

(2) 60 g of casein supplied by Bridel was added to 270 g of water containing 1.8 g of NaOH while stirring and heating. After complete dissolution, 15 g of Esperase 8.0L were added at 50 ° C., and 9 g of Termamyl 120L were added at room temperature in order to obtain a casein enzyme mixture.

(3) The mixtures obtained in steps (1) and (2) above were mixed together to obtain the premixed stabilized enzyme system of the invention.

The entire premixed stabilized enzyme system, i.e. about 570.6 g can be incorporated into an aqueous liquid dishwashing detergent or into an aqueous liquid thixotropic clay-containing dishwashing detergent to give about 3000 g of dishwashing detergent in which the stabilized enzyme system of the invention is present in the following amounts.

Percent by weight

NagB03 0.4 tartaric acid 1.0 casein 2.0 Esperase 8.0L 0.5 Termamyl 120L 0 ^ 3

Dishwashing detergents containing the stabilized enzyme system of the invention have been found to be effective in cleaning dirty dishes even in the absence of chlorine-releasing compounds.

Example 2

A stabilized enzyme system was prepared according to the procedure of Example 1, which contained the following ingredients.

Parts by weight

Na2B407.10H2O 0.8 citric acid 2.6 casein 2.0 Esperase 8.0L 0.5 Termamyl 120L 0 ^ 3

A thixotropic clay dishwashing detergent was prepared and about 90 parts by weight of the above stabilized enzyme system was added to about 81 parts by weight of a dishwashing detergent to give the following dishwashing detergent composition:

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Percent by weight

Demineralized water

43.7

caustic soda, solution (50% NaOH)

2.2

Sodium carbonate (anhydrous)

5.0

Sodium silicate (47.5% solution of Na20: SiQ21: 2.4)

15.74

Sodium TPP (essentially anhydrous, i.e. 0 to 5,

12.0

preferably 3% moisture) (Thermphos NW)

Sodium TPP (hexahydrate) (Thermphos N hexa)

12.0

N32B407. 10H20

0.8

citric acid

0.6

Casein

2.0

Esperase 8.0L

0.5

Termamyl 120L

0.3

Monostearyl phosphate

0.16

DOWFAX 3B-2 (45% sodium monodecyl / didecyldiphenyl-

0.80

oxide disulfonate, aqueous solution)

Aluminum stearate

0.20

Pharmagel H (thixotropic clay)

2.0

100.00

Example 3

The aqueous liquid thixotropic dishwashing detergent of Example 2, which contained the stabilized enzyme system of the invention containing 0.5% by weight Esperase 8.0L and 0.3% by weight Termamyl 120L enzymes, was after aging at 4 ° C, at room temperature and at 35 ° C after 1, 4 and 8 weeks tested for proteolytic and amylolytic activity. The results obtained are summarized in the following table.

Aging temperature

4 ° C

Room temp.

35 ° C

Aging time (weeks)

1 2

4 12 4

1 2

4th

proteolytic activity

77 -

58 - - 51

38

32

amylolytic activity

50

22

4th

-

The stabilized enzyme system of the invention consisting of borax-citric acid and casein-esperase and termamyl not only allows stabilization of amylase under very unfavorable conditions (amylase is normally destroyed at a pH of 9), but also enables observed amylolytic activity in the case of strongly alkaline Conditions (high pH). In fact, the dishwashing detergent showed amylolytic activity after 5 months of storage at room temperature.

Further tests have shown that the effectiveness of the above formulation in hard rinse water was greater than that of any dishwashing detergent on the market, in particular at a low concentration in the dishwasher of 5 g / l.

Example 4

An aqueous liquid dishwashing detergent according to the invention was produced which is suitable for washing dishes by hand and for washing particularly dirty dishes before washing them in the machine. The composition contained the following components in the amounts indicated.

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Percent by weight

Demineralized water

46.1

caustic soda, solution (50% NaOH)

2.2

Sodium carbonate (anhydrous)

5.0

Sodium silicate (47.5% solution of Na20: SiQ21: 2.4)

15.74

Sodium TPP (Thermphos NW)

12.0

Sodium TPP (Thermphos N hexa)

12.0

Na2ß407.10H2O

0.9

Lactic acid

1.8

Casein

2.0

Esperase 8.0L

0.8

• monostearyl phosphate

0.16

DOWFAX 3B-2 (45% aqueous solution of sodium mo

0.80

nodecyl / didecyldiphenyloxide disulfonate)

Aluminum stearate

0.50

100.00

In the above preparation of the detergent, the components and their amounts can be varied in order to obtain desired dishwashing detergents with special components and proportions.

Claims (23)

Claims 1. Water-based liquid dishwashing detergent, characterized by a content of a stabilized enzyme system, the dishwashing detergent - Water, - an alkali phosphate builder salt, - organic surfactant, - a boron compound, - a carboxylic acid, - a proteinaceous material and - contains an enzyme. 2. Dishwashing detergent according to claim 1, characterized in that the boron compound is at least one compound from the group consisting of borax (Na2B40z. IOH2O), sodium borate (Na3BC> 3), boric acid and boron oxide. 3. Dishwashing detergent according to claim 1, characterized in that the proteinaceous material is casein. 4. A water-containing thixotropic detergent according to claim 1 for dishwashers, characterized by a content of a stabilized enzyme system, the dishwashing detergent 40 to 55% by weight of water, 20 to 30% by weight sodium tripolyphosphate, 0.5 to 4.0% by weight of thixotropic clay thickener, 2.5 to 20% by weight of sodium silicate, 2 to 9% by weight of sodium carbonate, 0.3 to 2.0% by weight of anionic surfactant, - 0.75 to 2.0% by weight borax (Na2B407 .10H2O), -1.5 to 4.0% by weight of alpha-hydroxycarboxylic acid, -1.0 to 4.0% by weight of casein, - Contains 0.5 to 2.0% by weight of enzyme. 5. Dishwashing detergent according to claim 4, characterized by a sufficient to improve the physical stability of the composition of a metal salt content of a long-chain fatty acid as a stabilizing agent. 6. Dishwashing detergent according to claim 5, characterized in that the physical stabilizing agent is aluminum stearate. 7. Dishwashing detergent according to claim 5, characterized in that the stabilizing agent is present in an amount of 0.1 to 2% by weight. 8. Dishwashing detergent according to claim 4, characterized in that the thixotropic thickener is an inorganic or organic colloid-forming clay. 13 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 CH 676 006 A5 9. Dishwashing detergent according to claim 4, characterized in that the clay is a montmorillonite, attapulgite, hectorite or a smectite clay. 10. Dishwashing detergent according to claim 4, characterized by a content of 0.1 to 0.5 wt .-% of a foam-preventing agent. 11. Water-based liquid dishwashing detergent, characterized by a content of a stabilized enzyme system, the dishwashing detergent -35 to 65% by weight of water, 8 to 35% by weight of alkali phosphate builder salt, 0 to 20% by weight sodium silicate, 0 to 5% by weight of organic surfactant, 0.4 to 2% by weight of boron compound, -1 to 5% by weight carboxylic acid, -1 to 6% by weight of proteinaceous material, - Contains 0.5 to 6% by weight of enzyme. 12. Dishwashing detergent according to claim 11, characterized by a content of 0 to 5% by weight of a thixotropic clay thickener. 13. Dishwashing detergent according to claim 11, characterized in that the boron compound is at least one compound from the group consisting of borax (Na2B407. 10 H2O), sodium borate (Na3B03), boric acid and boron oxide, and that the carboxylic acid is an alpha-hydroxycarboxylic acid. 14. Dishwashing detergent according to claim 11, characterized in that it 40 to 55% by weight of water, 20 to 30% by weight sodium tripolyphosphate (TPP), -0 to 5% by weight of anionic organic surfactant, 0 to 20% by weight sodium silicate, 0 to 9% by weight sodium carbonate, 0 to 5% by weight of anti-foaming agent, -0.75 to 2.0% by weight borax (Na2B407 .10 H2O), -1.5 to 4.0% by weight of alpha-hydroxycarboxylic acid, -1.0 to 4.0 wt:% casein, - Contains 0.5 to 2.0% by weight of enzyme. 15. Dishwashing detergent according to claim 14, characterized in that the anionic surfactant is sodium trium (linear) tridecylbenzenesulfonate. 16. Dishwashing detergent according to claim 14, characterized in that the alpha-hydroxycarboxylic acid is at least one compound from the group consisting of lactic acid, tartaric acid, citric acid and the sodium salts thereof. 17. Dishwashing detergent according to claim 14, characterized in that the alpha-hydroxycarbonic acid contains citric acid and the sodium salt thereof. 18. Dishwashing detergent according to claim 11, characterized in that it 40 to 55% by weight of water, 20 to 30% by weight sodium tripolyphosphate, 0.25 to 5.0% by weight of thixotropic clay thickener, 0.1 to 5% by weight of anionic surfactant, 0 to 20% by weight sodium silicate, 2 to 9% by weight of sodium carbonate, 0.1 to 0.5% by weight of anti-foaming agent, - 0.75 to 2.0% by weight borax (Na2B4Û7.10 H20), -1.5 to 4.0% by weight of alpha-hydroxycarboxylic acid, -1.0 to 4.0% by weight of casein, - Contains 0.5 to 2.0% by weight of enzyme. 19. Dishwashing detergent according to claim 18, characterized in that the anionic surfactant is sodium (linear) decyl sulfonate. 20. Dishwashing detergent according to claim 18, characterized in that the alpha-hydroxycarboxylic acid is at least one compound from the group consisting of lactic acid, tartaric acid, citric acid and the sodium salts thereof. 21. Commercial process for cleaning dirty dishes, characterized in that the dirty dishes are brought into contact with the aqueous liquid dishwashing detergent of claim 1. 22. The method according to claim 21 for cleaning 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 detergent of claim 4 is dispersed. 23. Commercial process for cleaning 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 detergent of claim 14 is dispersed. 14