CH660374A5 - STABILIZED, CLEAR, SINGLE-PHASE, BUILDER AND ENZYME-CONTAINING LIQUID DETERGENT. - Google Patents

Description

The invention relates to a stabilized, clear, single-phase, builder and enzyme-containing liquid detergent based on anionic surfactants in water.

The formulation of stabilized, enzyme-containing liquid detergents has been the goal of many efforts to date. It is desirable to incorporate enzymes in detergents primarily because of the effectiveness of proteolytic and amylolytic enzymes in breaking down protein and starch on soiled textiles, which facilitates the removal of stains such as dripping, blood, chocolate and the like during washing. However, enzymatic substances suitable for detergents, in particular proteolytic enzymes, are relatively expensive. In general, they are even the most expensive part of a typical commercial liquid detergent, even when present in a relatively small amount. We also know that enzymes are unstable in aqueous mixtures. Therefore, an excess of enzymes is generally required in liquid detergents in order to compensate for the decrease in the enzyme action over extended storage times, which must be expected. The relevant literature is therefore full of proposals for stabilizing liquid detergents containing enzyme, in particular builder-free liquid mixtures by using various substances which are incorporated into the mixtures and serve as enzyme stabilizers.

In the case of liquid detergents that contain a builder, the problem of enzyme instability is particularly critical. This is primarily due to the fact that builders have a destabilizing effect on enzymes,

also in mixtures which contain enzyme stabilizers which are otherwise effective in formulations which do not contain builders. Furthermore, the incorporation of a builder into a liquid detergent poses another difficulty, namely that of forming a stable single-phase solution, since the solubility, e.g. of sodium tripolyphosphate, is relatively limited in aqueous mixtures, especially in the presence of anionic and nonionic surfactants. For example, British patent application 2,079,305 proposes an aqueous liquid detergent containing builder and enzyme which is stabilized by a mixture of polyol and boric acid. However, the mixtures described in the examples are cloudy suspensions instead of stable, clear single-phase solutions, which are easily subject to phase separation during longer storage times. As a result, enzyme stability and physical product stability continue to be problems to be solved by formulating an economically acceptable liquid detergent containing builder and enzyme.

The object of the invention is therefore to make available a stabilized, clear, single-phase, liquid builder and enzyme-containing detergent.

To achieve the object, a liquid detergent is proposed according to the invention from a) 8 to 20% by weight of one or more anionic surfactants;

b) 5 to 25% by weight of a water-soluble phosphate-free builder salt;

c) an effective amount of an enzyme or enzyme mixture from the group consisting of alkaline protease enzymes and α-amylase enzymes;

d) an enzyme stabilizing system which, based on the weight of the detergent, contains (i) 12 to 25% propylene glycol and (ii) 1 to 5% of a boron compound from the group consisting of boric acid, boron oxide and alkali borates; and e) 25 to 75% by weight water.

For washing, the stained and / or soiled materials can be brought into contact with an aqueous solution of the liquid detergent defined above. In contrast to the known builders and enzyme-containing detergents, the compositions of the invention are distinguished by the fact that they are clear, single-phase, homogeneous solutions which are physically stable over long storage times and over a wide temperature range. To avoid phase separation or product separation, the compositions according to the invention are preferably essentially free of phosphate builder salt.

Unlike the enzyme and builder-containing liquid detergents based on anionic surfactants of the prior art, the anionic detergent substance in the detergents according to the invention is solubilized in the presence of a builder salt. In addition, the enzyme-containing detergents according to the invention are notable for the presence of an enzyme-stabilizing system which not only ensures the long-term stability of the enzyme in a wide temperature range, but also promotes the solubility of the anionic surfactant and of the phosphate-free builder in the aqueous detergent, thereby forming a physically stable single-phase solution for the specific range of the specified compositions is made possible.

The enzyme stabilizing system of the invention is a mixture of propylene glycol and a boron compound of the group consisting of boric acid, boron oxide and alkali borate capable of reaction with propylene glycol. The amount of propylene glycol is about 12 to 25% by weight, preferably about 15 to 20% by weight, while the amount of the boron compound in the

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Range of 1 to 5%, preferably about 1 to 3%, based on the weight of the detergent, varies.

The alkaline proteolytic enzymes suitable for the detergents according to the invention comprise the various commercially available liquid enzyme preparations which have been adapted for use in detergents, enzyme preparations in powder form also being useful, although experience has shown that they are less useful for incorporating liquid detergents into Builder. Suitable liquid enzyme preparations are, for example, "Alca-lase" and "Esperase", which are sold by Novo Industries, Copenhagen, Denmark, and "Maxatase" and "AZ-Protease", which are sold by Gist-Brocades, in Delft, Netherlands . Esperase is particularly preferred for the detergents according to the invention because of its optimal effectiveness at the higher pH values of the detergents containing builders.

Suitable liquid α-amylase enzyme preparations are e.g. those sold by Novo Industries and Gist-Brocades under the respective trade names «Termamyl» and «Maxamyl».

The anionic surfactant used according to the invention can be one of the many known surfactants which have been described, for example, by Schwartz, Perry and Berch in Surface Active Agents, Volume 2, published in 1958 by Interscience Publisher, to which reference is made here.

The most preferred anionic surfactants are the higher (10 to 18 or 20 carbon atoms) alkylbenzene sulfonate salts or sulfonates, in which the alkyl group preferably has 10 to 15 carbon atoms, with a straight chain alkyl group having 12 to 13 carbon atoms being most preferred . Such an alkylbenzenesulfonate preferably has a high content of 3- (or higher) phenyl isomers and a correspondingly low content (generally well below 50%) of 2- (or lower) phenyl isomers; in other words, the benzene ring is preferably largely attached to the 3,4,5,6 or 7-position of the alkyl group, and the content of isomers in which the benzene ring is attached to the 1- or 2-position is accordingly low. Typical alkylbenzenesulfonate surfactants are described in U.S. Patent 3,320,174. Of course, more highly branched alkylbenzenesulfonates can also be used

however, are generally not preferred because of their lack of biodegradability.

Other anionic surfactants that can be used are the olefin sulfonate salts, which generally comprise long chain alkenyl sulfonates or long chain hydroxyalkane sulfonates (with the OH group on the carbon atom that is not directly connected to the carbon atom bearing the -SCbH group).

The olefin sulfonate surfactant usually consists of a mixture of such compounds in varying amounts, often together with long chain disulfonates or sulfate sulfonates. Such olefin sulfonates are described in patents such as in U.S. Patent 2,061,618, 3,409,637.3,332,880, 3,420,875, 3,428,654, 3,506,580 and British Patent 1,129,158. The number of carbon atoms in the olefin sulfonate is usually in the range of 10 to 25, more often 10 to 18 or 20 and is e.g. a mixture consisting mainly of C12, Ci4 and C le compounds with an average of about 14 carbon atoms, or a mixture of Cu, Cu, and C18 compounds with an average of about 16 carbon atoms.

Another class of valuable anionic surfactants is that of the higher paraffin sulfonates. These can be primary paraffin sulfonates which can be obtained by reacting long chain α-olefins with bisulfites, e.g. Sodium bisulfite, or

Paraffin sulfonates in which the sulfonate groups are distributed along the paraffin chain as in the products obtained by reacting a long chain paraffin with sulfur dioxide and oxygen under ultraviolet light and then neutralizing with sodium hydroxide or other suitable base (as in US Pat. No. 2,503 280, 2 507 088, 3 260 741, 3 372 188 and described in DE-PS 735 096). The paraffin sulfonates preferably contain 13 to 17 carbon atoms and are normally the monosulfonate, but optionally the di-, tri- or higher sulfonates. Usually the di- and polysulfonates are used in a mixture with a corresponding monosulfonate, e.g. as a mixture of mono- and disulfonates. which contains up to about 30% of the disulfonate. The hydrocarbon substituent thereof is preferably linear, although branched-chain paraffin sulfonates can optionally be used, although they are inferior in terms of biodegradability.

Other suitable anionic surfactants are sulfated ethoxylated higher fatty alcohols of the formula R0 (C2H40) mS03M, in which R is a fatty alkyl having 10 to 18 or 20 carbon atoms, m = 2 to 6 or 8 (a value of approximately 1A to V2 the number of carbon atoms is preferred in R) and M is a solubilizing salt-forming cation such as an alkali metal, ammonium, lower alkylamino or lower alkanolamino, or a higher alkylbenzenesulfonate in which the higher alkyl radical has 10 to 15 carbon atoms.

Ethylene oxide is the preferred lower alkylene oxide of the anionic alkoxylate surfactant, the proportion thereof in the polyethoxylated higher alkanol sulfonate is preferably 2 to 5 moles of ethylene oxide groups per mole of anionic surfactant, with 3 moles being particularly preferred, especially if the higher alkanol has 11 or 12 to 15 carbon atoms owns. In order to maintain the desired hydrophile-lipophilic balance when the amount of carbon atoms in the alkyl chain is in the lower part of the 10 to 18 carbon atom range, the ethylene oxide content of the surfactant can be reduced to about 2 moles per mole, whereas, when the higher alkanol has 16 to 18 carbon atoms corresponding to the higher part of the range, the number of ethylene oxide groups can be increased to 4 or 5 and in some cases even 8 or 9. Accordingly, a different cation can also be chosen to achieve the best solubility. This can be any suitable solubilizing metal or residue, but is mostly alkali metal, e.g. Sodium or ammonium. When lower alkylamine or alkanolamine groups are used, the alkyls and alkanols generally contain 1 to 4 carbon atoms, and the amines and alkanolamines can be mono-, di- and tri-substituted as in monoethanolamine, di-isopropanolamine and trimethylamine.

The poly-lower alkoxy higher alkanoisulfates can be used in combination with other preferred anionic surfactants such as e.g. the higher alkylbenzenesulfonates can be used in the liquid detergents containing builder according to the invention. A preferred polyethoxylated alcohol sulfate sid is sold by Shell Chemical Company under the trade name Neodol 25-3S.

Examples of the higher alcohol polypropylene oxysulfates that can be used in the liquid detergents of the invention are mixed Ci; _u normal or primary alkyl triethenoxy sulfate, sodium salt; Myristyl triethenoxysulfate, potassium salt; n-decyl diethenoxysulfate, diethanolam salt; Lauryl diethenoxy sulfate, ammonium salt; Palmitylte traethenoxysulfate, sodium salt; mixed C14.15 normal primary alkyl mixed tri- and tetra-ethenoxy sulfate,

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Sodium salt; Stearylpentaethene oxysulfate, trimethylamine salt; and mixed Cio-is normal primary alkyl triethenoxy sulfate, potassium salt.

Other valuable anionic surfactants include the higher acyl sarcosinates, e.g. Sodium N-lauroylsarkosi-nate; higher fatty alcohol sulfates such as sodium lauryl sulfate and sodium tallow alcohol sulfate; sulfated oils; Sulfates of mono- or diglycerides of higher fatty acids, e.g. Stearin monoglyceride monosulfate; of these, the higher alcohol sulfates have proven to be inferior to the polyethoxylated sulfates in terms of their cleaning effect; aromatic poly (lower alkenoxy) ether sulfates such as the sulfates of the condensation products of ethylene oxide and nonylphenol (which usually have 1 to 20 oxyethylene groups per molecule, preferably 2 to 12; polyethoxy-higher alcohol sulfates and alkylphenol polyethoxysulfates with a lower alkoxy (having 1 to 4 carbon atoms, e.g. Methoxy) substituents on a carbon atom near the carbon atom which carries the sulfate group, for example the monomethyl ether monosulfate of a long-chain vicinal glycol, for example a mixture of vicinal alkane diols with 16 to 20 carbon atoms in a straight chain; acyl esters of isethionic acid, for example oleyl isethionates; acyl-N- methyl taurides, e.g. potassium N-methyl lauroyl or oleyl taurides; higher alkylphenyl polyethoxysulfonates; higher alkylphenyl disulfonates, e.g. pentadecylphenyl disulfonate; and higher fatty acid soaps, e.g. mixed coconut oil and tallow soaps in a 1: 4 ratio.

Among the types of anionic surfactants mentioned above, the sulfates and sulfonates are generally preferred, but the corresponding organic phosphates and phosphonates can also be used if there are no objections to their phosphorus content. In general, the water-soluble anionic surfactants (including soaps) are salts of alkali metal ions such as potassium, lithium and especially sodium, although salts of ammonium and substituted ammonium cations such as those described above, e.g. Triethanolamine, Triisopropylamine, can also be used.

If necessary, a nonionic surfactant can be used in smaller amounts to supplement the anionic surfactant in the builder-containing liquid detergents according to the invention. When used in such a combination with an anionic surfactant, the amount of nonionic surfactant is generally less than about 10%, and preferably less than about 5%, based on the weight of the total mixture.

The nonionic surfactants are usually poly-lower alkoxylated lipophiles in which the desired hydrophilic-lipophilic balance is obtained by adding a hydrophilic poly-lower alkoxy group to a lipophilic portion. In the compositions according to the invention, the nonionic surfactant used is preferably a poly-lower alkoxylated higher alkanol in which the alkanol has 10 to 18 carbon atoms and in which the number of moles of lower alkylene oxide (with 2 or 3 carbon atoms) is 3 to 12. Of these materials, those in which the higher alkanol is a higher fatty alcohol having 11 or 12 to 15 carbon atoms and which contain 5 to 8 or 5 to 9 lower alkoxy groups per mole are preferably used. Preferably the lower alkoxy is ethoxy, but in some cases it is desirably mixed with propoxy, the latter, if present, generally being the minor (less than 50%) component. Examples of such compounds are those in which the alkanol has 12 to 15 carbon atoms and which contain about 7 ethylene oxide groups per mole, e.g. Neodol 25-7 and Neodol 23-6.5 by the

Shell Chemical Company, Inc. The former is a condensation product of a mixture of higher fatty alcohols with an average of about 12 to 15 carbon atoms and with about 7 moles of ethylene oxide, and the latter is a corresponding mixture in which the number of carbon atoms of the higher fatty alcohol is 12 to 13 and the number of ethylene oxide groups per Mol is about 6.5 on average. The higher alcohols are primary alcohols. Other examples of such surfactants include Tergitol 15-S-7 and Tergitol 15-S-9, both of which are Union Carbide Corporation linear secondary alcohol ethoxylates. The former is a mixed ethoxylation product of a linear secondary alkanol having 11 to 15 carbon atoms with 7 moles of ethylene oxide, and the latter is a similar product but is reacted with 9 moles of ethylene oxide.

Higher molecular weight nonionic substances such as Neodol 45-11, which are similar ethylene oxide condensation products of higher fatty alcohol, the higher fatty alcohol containing 14 to 15 carbon atoms and the number of ethylene oxide groups per mole being approximately 11, are also valuable for the detergents according to the invention. These products are also manufactured by Shell Chemical Company. Other valuable nonionic compounds are, for example, Plura-fac B-26 (BASF Chemical Company), which are the reaction product of a higher linear alcohol and a mixture of ethylene and propylene oxides.

In the preferred poly lower alkoxylated higher alkanols, the best balance between the hydrophilic and lipophilic portions is obtained when the number of lower alkoxy groups is about 40 to 100% of the number of carbon atoms in the higher alcohol, preferably 40 to 60% thereof. The nonionic surfactant preferably consists of at least 50% of the preferred ethoxylated alkanols. Higher molecular weight alkanols and various other normally solid nonionic surfactants and detersive agents can contribute to the gel formation of the liquid detergent and, as a result, are normally omitted or limited in the detergents of the present invention, although small amounts thereof can be used because of their cleaning properties, etc. In both the preferred and less preferred nonionic surfactants, the alkyl groups present are preferably linear, although a small amount of little branching can be tolerated, e.g. on a carbon atom adjacent to the terminal carbon atom of the straight chain or two carbon atoms away therefrom and away from the ethoxy chain, provided that such an alkyl branch is not longer than three carbon atoms. Typically, the amount of carbon atoms in such a branched configuration is small and rarely exceeds 20% of the total carbon atom content of the alkyl. Similarly, mid or secondary association with the ethylene oxide in the chain can occur, although linear alkyls that are terminally attached to the ethylene oxide chains are most preferred and are considered to be the optimal combination for cleaning power, biodegradability and non-gelling properties . In such a case it is usually only a small part of these alkyls, generally less than 20%, but can be larger, as in the case of the tergitols mentioned above. Furthermore, propylene oxide, when present in the lower alkylene oxide chain, will usually make up less than 20% of the same, and preferably less than 10% thereof.

The phosphate-free builder salts are used in the detergents according to the invention in amounts of about 5 to 25

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% By weight and preferably from about 10 to 20% by weight. Specific examples of non-phosphorus water-soluble inorganic builders are water-soluble inorganic carbonate, bicarbonate and silicate salts. According to the invention, the alkali metal such as e.g. Sodium and potassium carbonates, bicarbonates and silicates are particularly valuable.

Water soluble organic builders such as alkali, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates and polyhydroxysulfates can also be used. Specific examples of polyacetate and polycarboxylate builders are sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylenediaminetetraacetic acid, nitrilotriacetic acid, benzene polycarbonate (e.g. penta- and tetra-) acids, carboxymethoxysuccinic acid and citric acid.

The percentage of water, the main solvent in the detergents according to the invention, is about 25 to 75%, preferably 40 to 60%, based on the weight of the detergent.

The optical brighteners or whitening agents used in the liquid detergents of the invention are important components of modern detergents which give the washed laundry and the washed textiles a luminous appearance, so that the laundry is not only clean but also appears clean. Although it is possible to use a single brightener in the liquid detergents of the invention for a specific purpose, it is generally desirable to use brightener blends that have good brightener effects on cotton, nylon, polyesters and blends of such materials and that are also bleach resistant. A good description of such optical brighteners can be found in the article by A.E. Siegrist “The Requirements of Present Day Detergent Fluorescent Whitening Agents” in J. Am. Oil Chemists Soc., January 1978 (Volume 55). This article and U.S. Patent 3,812,041, both of which are incorporated herein by reference, contain detailed descriptions of a wide variety of suitable optical brighteners.

Brighteners which can be used for the detergents according to the invention are, for example: Calcofluor 5BM (American Cyanamid); Calcofluor White ALF (American Cyanamid); SOF A-2001 (Ciba); CDW (Hilton-Davis); Phorwite RKH, Phorwite BBH and Phorwite BHC (Verona); CSL, powder, acidic (American cyanamide); FB 766 (Verona); Blancophor PD (GAF); UNPA (Geigy); Tinopal RBS 200 (Geigy).

Auxiliaries may be present in the liquid detergents to ensure additional properties, both functional and aesthetic. Such valuable adjuvants are dirt-bearing or anti-anti-reprecipitants such as polyvinyl alcohol, sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose; Thickeners, e.g. Gums, alginates, agar agar, foam improvers, e.g. lauric myristine diethanolamide; Foam destroyer, e.g. Silicones; Bactericides, e.g. Tribromosalicylanilide, hexachlorophene; Dyes; Pigments (water dispersible); Protective substances; Ultraviolet absorber; Fabric softeners; opacifying agents, e.g. Polystyrene suspensions; and fragrances. Of course, these materials are selected according to the desired properties of the finished product, their compatibility with the other components and their solubility in the liquid detergent.

The liquid detergents according to the invention are effective and easy to use. Compared to powdery coarse detergents for washing laundry, much smaller volumes of the detergents according to the invention are used to achieve comparable cleaning of the soiled laundry. For example, using a typical preferred formulation of the invention, only about 132 grams or Vi cups of liquid are required for a full tub in an automatic top-loading washing machine in which the volume of water is 55 to 75 liters (15 to 18 gallons), and for machines filling from the side or front, the required quantity is even less. The concentration of the liquid detergent in the wash water is of the order of about 0.2%. In general, the liquid detergent is present in the wash solution in an amount of about 0.05 to 0.3%, preferably 0.15 to 0.25%. The proportions of the various constituents of the liquid detergent can vary accordingly. Equivalent results can be achieved by using larger amounts of a more dilute formulation, but the larger amount required requires additional packaging and is generally less expedient for use.

example 1

Enzyme-containing liquid detergents A-E were formulated as shown in Table 1. The percentages given are percentages by weight.

Table I

25th

A

B

C.

D

E

Sodium dodecylbenzene

sulfonate

7%

7%

7%

7%

7%

Ethoxylated C12-C15

Alcohol sulfate (3 mol

EO / mol alcohol) 1

7

7

7

7

7

Brightener

0.2

0.2

0.2

0.2

0.2

Sodium nitrilotriacetate

15

15

15

15

15

PBB2

1

1

1

1

1

Fragrance

0.3

0.3

90.3

0.3

0.3

Protease enzyme 3

1

1

1

1

1

Propylene glycol

-

20th

20th

20th

20th

borax

-

-

1

2nd

3rd

water

Percent active enzyme after io a) 4 days at 43.3 ° C (110 ° CF)

b) 6 days at 43.3 ° C (110 ° F)

rest

98

15 61 86 88

45

'Neodol 25-3S from Shell Oil Company.

2 Polar brilliant blue, 1% active dye solution.

3 “Esperase” from Novo Industries made from 5% enzyme, 75% propylene glycol and the rest water with an activity of 8.0

50

KNPU / g (Kilo Novo protease units / g)

The enzyme activities of detergents A-E were compared

Tested for 6 days at 43.3 ° C (110 ° F), indicating 55 percent activity relative to the initial value shown in Table I. The activity after 4 days was only determined for sample E. Mixtures A and B were the only compositions that did not contain an enzyme stabilization system according to the invention, 60 they showed complete (detergent A) or almost complete (detergent B) loss of enzyme activity after 6 days. The detergents C, D and E reflect the considerable improvement in the enzyme stability due to the incorporation of propylene glycol and borax into the detergent mixture 65.

Mixtures B to E were all clear, single-phase, homogeneous solutions that showed their physical stability and clarity after 6 months of storage both at room temperature and

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maintained temperature as well as 43.3 ° C (110 ° F). Mixture A, which was not composed according to the invention, was physically unstable due to the absence of propylene glycol, which in addition to its enzyme stabilizing effect (in conjunction with the boron compound mentioned above), the solubility of the anionic surfactants and the NTA builder in the aqueous mixture promotes.

Example 2

Liquid detergent mixtures F and G containing enzyme and builder were formulated, which were similar to mixtures A to E, except that sodium citrate was used as builder salt instead of sodium NTA. The compositions are shown in Table II below.

Table II

L

G

Sodium dodecylbenzenesulfonate

7%

7%

Ethoxylated Ci2-Ci5 alcohol

sulfate (3 moles EO / mole alcohol)

7

7

Brightener

0.2

0.2

Sodium citrate

12

12

PBB1

1

1

Fragrance

0.3

0.3

Protease enzyme 2

1

1

Propylene glycol

20th

20th

borax

-

2nd

water

Percent active enzyme after

4 days at 43.3 ° C (110 ° F)

20th

95

1 polar brilliant blue, 1% active dye solution.

2 “Esperase” from Novo Industries, containing 5% enzyme, 75% propylene glycol and the rest water, with an activity of 8.0 KNPU / g (Kilo Novo protease units / g).

Composition G according to the invention showed an enzyme activity of 95% after 4 days, whereas composition F, which did not contain any boron compound, lost more than% of its original enzyme activity.

Both compositions were clear single phase solutions that remained stable after 6 months of storage at both room temperature and 43.3 ° C (110 ° F).

Example 3

Liquid detergent compositions H, I and J containing enzyme and builder were formulated which were substantially similar to compositions F and G in Example 2s, except that they contained a mixture of protease and a-amylase enzymes instead of a single protease enzyme. The compositions are shown in Table III.

Table III

H

I.

J

Sodium dodexylbenzenesulfonate

7%

7%

7%

Ethoxylated Ci2-Cis alcohol

sulfate (3 moles EO / mole alcohol)

7

7

7

Brightener

0.2

0.2

0.2

Sodium citrate

12

12

12

PBB1

1

1

1

Fragrance

0.3

0.3

0.3

Protease enzyme 2

1

1

1

a-amylase enzyme 3

0.4

0.4

0.4

Propylene glycol

20th

20th

20th

borax

-

1

3rd

water

- rest

Percent active enzyme after

4 days at 43.3 ° C (110 ° F)

a-amylase enzyme

50%

67%

87%

Protease enzyme

30th

73

94

301 polar brilliant blue, 1% active dye solution.

2 “Esperase” from Novo Industries, containing 5% enzyme, 75% propylene glycol and the remainder water, with an activity of 8.0 kNPU / g (Kilo-Novo protease units / g).

3 "Termamyl" from Novo Industries, containing 5% enzyme, 35 18% NaCl and the remainder water with an activity of

120,000 novo amylase units per gram.

Compositions I and J according to the invention 40 showed a significantly more stable enzyme activity after 4 days for both the protease and for the amylaseen enzymes, in comparison with the composition H which did not contain any boron compound and consequently Vi of its initial amylolytic activity and about Vi lost its initial 45 proteolytic activity during the 4 day storage period.

All three compositions were clear single-phase solutions that remained physically stable after 6 months of storage.

G

Claims (8)

660 374 1. Stabilized, clear, single-phase, builder and enzyme-containing liquid detergent based on anionic surfactants in water, characterized by a) 8 to 20% by weight of one or more anionic surfactants; b) 5 to 25% by weight of a water-soluble phosphate-free builder salt; c) an effective content of an enzyme or enzyme mixture from the group consisting of alkaline protease enzymes and α-amylase enzymes; d) an enzyme stabilizing system, based on the weight of the detergent, (i) 12 to 25% propylene glycol and (ii) 1 to 5% of a boron compound from the group consisting of boric acid, boron oxide and alkali borates; and e) 25 to 75% by weight water. 2. Detergent according to claim 1, characterized in that the builder salt is sodium citrate. 2nd PATENT CLAIMS 3. Detergent according to claim 1, characterized in that the builder salt is sodium nitrilotriacetate. 4. Detergent according to claim 1, characterized in that it contains essentially no phosphate builder salt. 5. Detergent according to claim 1, characterized in that it contains 15 to 20 wt .-% propylene glycol and 1 to 3 wt .-% of the boron compound. 6. Detergent according to claim 1, characterized in that the boron compound is borax. 7. Detergent according to claim 1, characterized in that the builder salt is present in an amount of 10 to 20 wt .-%. 8. Detergent according to claim 1, characterized in that the anionic surfactant is a mixture of a Cio-Ci8-alkylbenzenesulfonate and a polyethoxylated Cio-Cis alcohol sulfate.