LU86525A1 - STABILIZED REINFORCED LIQUID DETERGENT COMPOSITION CONTAINING ENZYMES AND WASHING METHOD USING THE SAME - Google Patents

Description

Τι “1 Λ r · '

The present invention relates to reinforced, stable liquid detergent compositions containing enzymes, suitable for washing or pre-washing formulations for laundry. More particularly, the invention relates to aqueous liquid detergent compositions containing enzymes, which contain one or more detergency builders and which are characterized in that they are homogeneous, physically stable liquid compositions.

The prior art has focused strongly on the formulation of stabilized liquid detergent compositions containing enzymes. The desire to incorporate enzymes into detergent compositions is mainly based on the effectiveness of the proteolytic and amylolytic enzymes in breaking down the protein and starchy materials found on soiled tissue, thereby facilitating the removal of stains, by e.g. sauce stains, blood stains, chocolate stains, etc., during laundering. However, the enzyme materials suitable for bleaching compositions, particularly the proteolytic enzymes, are relatively expensive. In fact, they are among the most expensive ingredients of a conventional commercial liquid detergent composition, even if they are present in relatively minor amounts. In addition, enzymes are known to be unstable in aqueous compositions. For this reason, it is generally necessary to use an excess of enzymes in liquid detergent formulations in order to compensate for the expected loss of enzyme activity during extended periods of storage. Therefore, the prior art abounds with proposals for stabilizing liquid detergent compositions containing enzymes, and in particular unreinforced liquid compositions, using various materials which are incorporated into the composition to act as enzyme stabilizers.

In the case of liquid detergent compositions containing a detergency builder, the problem of enzyme instability is particularly acute. This is mainly due to the fact that detergency builders exert a destabilizing effect on enzymes, even in compositions containing enzyme stabilizers, which are also effective in unreinforced formulations.

Furthermore, the incorporation of a detergency builder into a liquid detergent composition poses another problem, namely that of being able to form a stable composition in a single phase, the solubility of sodium tripolyphosphate, for example, being relatively limited. in aqueous compositions, and in particular in the presence of anionic and nonionic detergents.

In British Patent Application No. 2,079,309, an enhanced aqueous liquid detergent composition containing enzymes is described which is stabilized by a mixture of a polyol and boric acid. As mentioned in the examples of this application, relatively large amounts of glycerol are required to stabilize the enzymes of the composition. However, as highlighted in the remainder of this report, the stabilizing effect of the enzymes provided by a mixture of glycerin and borax in a reinforced aqueous liquid detergent composition is relatively moderate.

The European patent application published under No. 0126505 describes an aqueous liquid detergent composition containing enzymes and containing an enzyme stabilization mixture consisting of certain dicarboxylic acids and borax. Dicarboxylic acids are recommended as a substitute for a polyol such as glycerol in * 3 <Γ known enzyme stabilization mixtures consisting of glycerol and a boron compound. However, the dicarboxylic acid-borax mixtures of this publication, as well as the above-mentioned mixture of glycerin and borax 05 of the prior art offer at most a moderate stabilizing effect in the reinforced liquid detergent compositions of the present invention. It is therefore necessary to greatly improve the stability of the enzymes of reinforced aqueous liquid detergent compositions of the type defined here, to an extent much greater than that of the current possibilities of the technique.

The present invention provides an enhanced, stabilized, liquid, detergent composition containing enzymes, comprising: (a) about 5-20% by weight of one or more surfactant detergent compounds selected from anionic detergent compounds , non-ionic and ampho-teres? (B) about 5 to 30% by weight of one or more adjuvant detergency salts, chosen from alkali metal tripo-lyphosphates, alkali metal carbonates, alkali metal nitrilotriacetates and polyacetal-carboxylates; (C) an effective amount of an enzyme or mixture of enzymes selected from alkaline enzymes of the protease and alpha-amylase type; (d) an enzyme stabilization system containing, based on the weight of the detergent composition, (i) about 1 to 10% glycerin; (ii) approximately - 1 to 8% of a boron compound chosen from boric acid, boric oxide and alkali metal borates and (iii) approximately 0.5 to 8% of a compound of the type carboxylic acid chosen from mono-, di-35 and / or polycarboxylic acids of 1 to 8 carbon atoms and their water-soluble salts; and (e) the remainder consisting of water and possibly * 4 ï · * in perfume and other additives.

In a preferred embodiment of the invention the liquid detergent composition comprises: 05 (a) about 5 to 15% of an alkali metal alkylbenzene sulfonate in which the alkyl group contains from 12 to 15 carbon atoms? (b) about 2 to 5% of an alkali metal alkyl polyethylene sulfate in which the alkyl group contains 10 to 10 to 18 carbon atoms and the polyethoxy chain has 3 to 11 ethylene oxide groups, the ratio by weight from (a) to (b) being from about 2: 1 to about 8: 1; (c) about 5 to 20% of sodium 15-tripolyphosphate; (d) about 1 to 10% sodium carbonate, the weight ratio of (c) to (d) being from about 2: 1 to about 6: 1; (e) an effective amount of the above enzyme or mixture of enzymes; (f) an enzyme stabilization system containing, based on the weight of the detergent composition, (i) about 3 to 7% glycerin, (ii) about 1 to 5% of an alkali metal borate, and ( iii) about 0.5 to 4% of said carboxylic acid compound; and (g) the balance consisting of water and, optionally, perfume and other additives.

According to the process of the invention, the washing of stained and / or soiled materials is carried out by bringing these materials into contact with an aqueous solution of the liquid detergent compositions defined above.

The liquid detergent described is a detergent for heavy laundry laundering, acceptable for commercial purposes, capable of properly cleaning laundry containing both oily and particulate soils. In addition, the compositions described can be used for the pretreatment of very dirty parts, such as the collars and cuffs of articles to be washed.

The present invention is based on the discovery of a three-component enzyme stabilization system as defined herein, which confers an enzyme stabilization effect on the liquid detergent compositions of the invention much greater than. 10 which can be obtained with conventional enzyme stabilizers. The enzyme stabilization effect thus obtained is the result of a synergy of the three components. According to the invention, the stability of enzymes provided by a mixture of glycerin and borax or a mixture of borax and a dicarboxylic acid, as described in the prior art, can be improved synergistically by using the three-component stabilizing system defined here in the liquid compositions of the invention, so as to raise the degree of stability of the enzymes far above that provided either by the mixture of glycerin and borax, or by the mixture of borax and dicarboxylic acid when used independently of one another as enzyme stabilizers. For commercial purposes, desirable enzyme stability generally corresponds to about a half-life of one week at a temperature of 43 ° C.

the enzyme stabilization system of the invention is a mixture of glycerin, a boron compound chosen from boric acid, boric oxide and an alkali metal borate and a compound of carboxylic acid type, as defined here. The weight of the stabilizing system contained in the reinforced liquid detergent compositions of the invention generally represents about 3 to 25%, preferably about 6 to 15% of the weight of these compositions. The weight ratio of glycerin to borax of stabilization mixtures is generally about 1 to 3. The preferred amount of glycerin in the composition is about 3 to 7% / the preferred amount of boron compound is about 1 to 5%, and the preferred amount of carboxylic compound is about 0.5 to 4%, based on the weight of the composition.

Carboxylic acid compounds which are useful in the enzyme stabilization system of the invention include saturated mono-, di- and polycarboxylic acids as well as unsaturated acids having 1 to 8 carbon atoms, among which may be mentioned oxalic acid (HOOCCOOH), malonic acid (HOOCCH2COOH), maleic acid (HOOCCHICHCOOH) and succinic acid (HOOCCI ^ CI ^ COOH). Carboxylic acids can contain hydro-xy or amino substituents, such as for example malic acid (HOOCCHOHCH ^ COOH), tartaric acid (dihydroxy-succinic acid), aspartic acid (amino-succinic acid) and citric acid. Preferred carboxylic acids of the invention are succinic acid, maleic acid, malonic acid and malic acid.

From a commercial point of view, a particularly preferred carboxylic acid is citric acid and / or its salts due to their relatively low uptake.

The alkaline proteolytic enzymes suitable for the compositions of the present invention include the various commercial liquid enzyme preparations which have been developed for use in detergent compositions. Enzyme pre-parafions in powder form are also useful although, as a general rule, they are less convenient to incorporate into reinforced liquid detergent compositions. Thus, suitable liquid enzyme preparations include "Alcala-35 se" and "Esperase", sold by Novo Industries, Copenhagen, Denmark, and "Maxatase" and "AZ-Protease" sold by Gist-Brocades, Delft, Netherlands.

* 7

Among the suitable liquid enzymatic preparations of the o (-amylase) type, there may be mentioned those sold by Novo Industries and Gist-Brocades under the trade names "Termamyl" and "Maxamyl", respectively.

"Esperase" is particularly preferred for the compositions of the invention because of its optimized activity at higher pH values corresponding to the reinforced detergent compositions.

The preferred detergents for use in the liquid compositions of the invention are the synthetic anionic detergent compounds, and in particular a mixture of (higher alkyl) benzene tallow onate and alkyl polyethoxy sulfate. Although the formulas of the present invention may also contain other water-soluble (higher alkyl) benzene sulfonates, for example potassium salts and, in some cases, ammonium or alkanolammonium salts, where appropriate. is suitable, it has been found that the sodium salt is the preferred one, which is also the case with regard to the alkyl polyethoxy sulphate detergent component. The alkylbenzene sulfonate is one in which the upper alkyl group has from 12 to 15 carbon atoms, preferably 13 carbon atoms. The alkyl polyethoxy sulfate, which may also be referred to as a sulfated polyethoxylated higher linear alcohol or the sulfated condensation product of a higher fatty alcohol and ethylene or polyethoxylene glycol, is that in which the alkyl group contains from 10 to 18 carbon atoms, preferably from 12 to 15 carbon atoms, for example about 13 carbon atoms, and which contains from 3 to 11 ethylene oxide groups, preferably from 3 to 7, more preferably 3 to 5, and in particular 3 or about 3 ethylene oxide groups. The ratio of alkyl benzene sulfonate to polyethoxy sulfate in the detergent mixture is preferably about 8 2: 1 to 3. 8: 1, and more preferably about 3: 1 to 5: 1 by weight.

At ratios greater than 5: 1, the physical stability of the product may be adversely affected.

In appropriate cases, other anionic detergents such as fatty alcohol sulfates, paraffin sulfonates, olefin sulfonates, monoglyceride sulfates, sarcosinates and detergents with similar function, preferably in the form salts of alkali metals, for example sodium, may be present, sometimes in partial replacement of the organic synthetic detergents previously mentioned, but, in general, their possible presence is added to that of such detergents. Normally, additional detergents are sulfated or sulfonated products (generally in the form of sodium salts) and contain fatty or linear long chain alkyl groups (8 to 20 carbon atoms).

In addition to any additional anionic synthetic organic detergents, non-ionic and amphoteric materials may also be present, such as Neodols, sold by Shell Chemical Company, which are ethylene oxide (R 1 and higher fatty alcohols, for example Neodol '' 23-6.5, which is a condensation product of a higher fatty alcohol of about 12 or 13 carbon atoms with about 6.5 moles of ethylene oxide. various detergents and classes of detergents mentioned can be found in Surface Active Agents, Vol. II, of Schwartz, Perry and Berch (Interscience Pu-30 blishers, 1958).

The combination of detergent builder salts of the present invention, which has been shown to improve the detergency of the mixture of synthetic anionic organic detergents and to produce the desired pH in the liquid detergent and in the wash water, is a mixture of sodium tripolyphosphate and sodium carbonate. The detergent builder salts 9 are used in the compositions of the present invention in amounts generally of from about 5 to 25 I by weight. In the preferred combination of detergency builder salts, sodium tripoly-05 phosphate is present in proportions of about 5 to 20%, preferably 10 to 16%, and sodium carbonate is present in an amount of about 1 at 10% by weight, preferably 3 to 7%, the weight ratio of tripolyphosphate to carbonate in the mixtures of preferred detergency builders being from about 2: 1 to 6: 1, and more preferably of about 2: 1 to 4s1. As used herein, the terms "carbonates" or "carbonate" of alkali metal denote carbonates, bicarbonates and sesquicarbonates of such alkalinic metals.

In order to achieve the best processing properties, easier mixing and satisfactory end use, it is preferable that the sodium tripolyphosphate has a low content of tripolyphosphate of the Phase I type. Thus, normally, the content of tripolyphosphate of the type Phase I is less than 30% of the tripolyphosphate used.

Although in some cases partially neutralized tripolyphosphate can be used, the phosphate used is normally considered to be pentasodium tripolyphosphate Na ^ P ^ O ^ Q. Obviously, in certain cases, for example in the presence of potassium salts or other materials, the mutual exchange of ions in an aqueous medium can give salts other than sodium tripolyphosphate, but * for the purposes of this specification Descriptive, it is considered that the sodium tripolyphosphate, in the form of the pentasodium salt, which is the material normally introduced into the mixer for manufacturing the liquid detergent of the invention, is the tripolyphosphate used.

Other preferred detergency builder salts which may be used in place of, or in addition to, sodium tripolyphosphate and sodium carbonate include a polyacetal carboxylate as described herein and sodium nitrilotriacetate (NTA). Obviously, various mixtures of the mentioned water soluble builder salts can be used. However, the tripolyphosphate-carbo-nate mixture described has proved to be the most advantageous, although the other detergency builders and their mixtures are also usable. Other detergency builders which can be used as supplements, in addition to the proportions of the detergency builders mentioned above, include other phosphates such as tetra sodium pyrophosphate or tetrapotassium pyrophosphate, sodium bicarbonate, citrate sodium, sodium gluconate, sodium silicate, and sodium sesquicarbonate. Among the water-insoluble detergency builders that can be used are zeolites, such as Zeolite A, generally in the form of its crystalline hydrate, although amorphous zeolites may also be useful.

The polyacetal carboxylates are generally described in the patents of E. ü. A. No. 4,144,226 and No. 4,315,092. U.S. Patent 4,146,495 describes detergent compositions containing polyacetal carboxylates as detergency builders.

The polyacetal carboxylates which are useful herein as detergency builders can be considered to be those described in U.S. Patent No. 4,144,226 and can be prepared by the process mentioned therein. An example of such a product is represented by the formula: R. - (CHO) - R 1. n 2 35 1

COOM

* 11 where M is chosen from an alkali metal, ammonium, alkyl groups of 1 to 4 carbon atoms, tetraalkylammonium groups and alkanolami-ne groups, these last two types of groups having from 1 to 405 atoms carbon in their alkyl portions, n is on average at least 4, and R ^ and R2 are chemically stable groups which stabilize the polymer against rapid depolymerization in alkaline solution. Preferably, the polyacetal-10 carboxylate is that in which M is an alkali metal, for example sodium, n ranges from 50 to 200, R ^ is

CH3CH2O MOOC

HCO- ° U H3C-CO- 15 · 1

H3C MOOC

or a mixture of these groups, R2 is 20 OCH2CH3

-CH

t CH3 and na has an average value of 20 to 100, preferably 25 to 30 to 80. The calculated weight average molecular weights of the polymers are normally in the range from 2000 to 20,000, preferably from 3,500 to 10,000, and better still from 5000 to 9000, for example around 8000.

A particularly preferred sodium polyacetal carboxylate is sold by Monsanto Company and is known as Builder U. It has a calculated average molecular weight of about 8000 and an active polymer content of about 80%.

Although the preferred polyacetal carboxylates have been described above, it is evident that they can be replaced in whole or in part by other polyacetal carboxylates of this type or the related organic detergency builder salts described. in the aforementioned patents relating to such compounds, their manufacturing processes and the compositions in which they are used.

Also, the chain terminating groups described in the various patents, in particular US Pat. No. 4,144,226, can be used, provided that they have the desired stabilizing properties, which allow the mentioned detergency builders to be depolymerized in acidic media, facilitating their biodegradation in waste streams, but maintain their stability in alkaline media, such as washing solutions.

The only other necessary component of the liquid detergents of the invention is water. Normally, the hardness of this water is less than about 300 ppm, as CaCO 4, and preferably it is less than 150 ppm. It may often be desirable to use deionized water, although city water, of a hardness less than 50 or 100 ppm, is often just as satisfactory.

Various additives may be present in liquid detergents, such as brightening agents, perfumes and dyes. Brightening fluorescent agents include the well known derivatives of stilbene, including brightening agents of cotton and Nylon, for example those sold under the trademark Tinopal (5BM Conc.). The perfumes which are used generally include essential oils, esters, aldehydes and / or alcohols, all of which are known in the art of perfumery. The dyes may include water dispersible dyes and pigments of various types, including ultramarine blue. Salts of mineral fillers, such as sodium sulfate and sodium chloride, may be present, as well as 13% "anti-deposition agents" such as sodium carboxymethylcel-lulose; dispersing agents such as sodium polyacrylate? bleaching agents; bactericides, fungicides; anti-foaming agents such as silicones; anti-fouling agents such as copolyesters; preservatives such as formalin; foam stabilizers such as myristic lauric diethanolamide; and auxiliary solvents such as ethanol. Normally, the individual proportions of such additives are less than 3%, often less than 1% and sometimes even less than, 0.5%, except for fillers and solvents, and other detergents and detergency builders for which the proportions 15 can sometimes be as high as 10%. The total proportion of additives, including synthetic detergents and non-designated detergency builders, does not represent more than 20% of the product, and advantageously less than 10%, better still less than 5%.

Obviously, the additives used are chosen so as not to disturb the washing action of the liquid detergent and to avoid the instability of the product at rest. Also, additives that cause unwanted deposits on the laundry should be avoided.

The liquid compositions of the invention are effective and easy to use. Compared to detergent powders for large laundries, much smaller volumes of the liquids of the present invention are used to achieve comparable cleaning of soiled laundry. For example, using a typical preferred formulation of the present invention, only about 132 grams or one V2 cup of liquid is required for a full wash tub of an automatic top-loading washing machine in which the water volume is 57 to 68 liters; and even less for front loading machines. Thus, the concentration of the liquid detergent composition in the wash water is of the order of about 0.2%. Usually, the proportion of the liquid composition in the washing solution is between about 05 0.05 and 0.3%, preferably between 0.15 and 0.25%.

The proportions of the various constituents of the liquid composition can vary accordingly. Equivalent results can be obtained by using larger proportions of a more dilute formulation, but the larger amount required requires additional packaging and is less convenient for the consumer to use and may also result in separation. of the product.

The viscosity of the liquid detergent of the invention is normally about 1000 to 10,000 mPa.s, preferably 2,000 to 5,000 mPa.s, but products having other suitable viscosities may also be useful. At the viscosity values mentioned, the liquid detergent can be poured, it is stable, does not separate and is uniform. The pH of the liquid detergent suspension, generally from 7 to 11.5, preferably from 8 to 10.5, seems to favor the maintenance of the stability of the product and its ability to be poured.

The following nonlimiting examples illustrate the invention. Unless otherwise indicated, all parts are expressed by weight and temperatures in ° C.

EXAMPLE 1 30 Percent Components

Pentasodium tripolyphosphate 15.0

Sodium carbonate 5.0 (linear tridecyl) sodium benzenesulfonate 12.2 35 AEOS (2.8 Carboxymethylcellulose (CMC) 0.15

Optical brightening agent 0.4 15

Perfume 0.3

Enzyme (Esperase 8.0L) 1.0

Glycerin 4.0

Borax 3.0 05 Triethanolamine 1.0

Sodium citrate 2.0

Water and additives the rest.

^ Sodium alkyl polyethoxy sulphate in which the alkyl group contains from 12 to 15 carbon atoms and the polyethoxy chain has 3 ethoxy groups.

(2) "Esperase", sold by Novo Industries with an activity of 8.0 KNPU / g (Kilo-units of Novo protease / g).

The composition indicated above is prepared by the following procedure: 32.5 parts of deionized water are added to a suitable mixing device such as a vertical cylindrical tank equipped with a stirrer. By setting the agitator to a medium degree of agitation, a mixture consisting of 5.0 parts of anhydrous sodium carbonate and 0.17 part of sodium carboxymethyl cellulose in water is incorporated. The speed of the agitator is then increased to a maximum value and 15.0 parts of pentasodium tripolyphosphate are slowly added to the mixing apparatus over a period of 10 to 15 minutes to form a milky white suspension. The stirring speed is then reduced to a slow / medium value while adding 19.1 parts of a suspension of LTBS with a high content (about 50%) of IA (active ingredient). The solution of optical brightener and dye consisting of 0.4 part of Tino-pal LMS-X (CIBA-GEIGY), 0.06 part of blue dye 35 and 2.0 parts of water is then added. deionized. As soon as a homogeneous blue color solution has been obtained, 0.3 part of perfume is added to the mixture with stirring. Next, 4.0 parts of glycerin, 3.0 parts of borax and 1.0 part of triethanolamine (TEA improves long-term product stability) are slowly added as a three-component suspension. Stirring is continued until the mixture is homogeneous in appearance, then 2.0 parts of sodium citrate and 4.0 parts of water are slowly added * The stirring of the mixture is then reduced while adding to it a detergent base of mixed active ingredients consisting of 5.7 parts of TLBS suspension (approximately 50% of AI) and 4.7 parts of AEOS (approximately 60% of IA). 1.0 part of proteolytic enzyme is then added with continuous stirring until all of the materials are completely dispersed or dissolved.

• 15 EXAMPLE 2

The reinforced liquid detergent compositions A to G containing enzymes are formulated as indicated below in Table 1. The percentages indicated are expressed in percent by weight. The arrows are used to indicate the extent to which Compositions B to G are identical to Composition A.

TABLE 1

25 Components A B C D E F G

15% pentasodium tripolyphosphate

Sodium carbonate (anhydrous) 5% (linear tridecyl) benzene - sodium suet ona 12.2 30 AEOS * 1 * 2.8

Optical brightening agent (Tinopal LMS-X) 0.4

Perfume 0.3 CMC 0.2

35 Enzyme “2) l V ψ φ- j, V

Glycerin - 4-4--4

Borax - - 3 3 - 3 3, - · / / / 1 - ~ t 17

Carboxylic acid - - - - 2 2 2

Water and additives the rest ------- ^ Sodium alkyl-polyethoxy-sulfate in which the alkyl group has 12 to 15 carbon atoms and the polyethoxy chain has 3 ethoxy groups.

(2) '"Esperase" sold by Novo Industries with an activity of 8.0 KNPU / g.

The enzymatic activities of Composi-10 tions A to G are tested after 7 days of storage at 43 ° C. The enzymatic activity measured for each composition after this storage period is indicated in Table II and in Table III as a percentage of the initial value. The various carboxylic acids and salts used in the formulas of Compositions A, B, C, D, E and G are indicated in Table II as well as the enzymatic activity corresponding to each composition.

20 TABLE II

ENZYMATIC STABILITY

Composition Percent of enzymatic activity at the end

_7 days at 43 ° C

25 a (Witness) ND *

B (with glycerin) ND

C (with borax) ND

D (with glycerin and borax) 45

Composition E (with compound of carboxylic acid type) the compound of carboxylic acid type being one of the following: (1) Succinic acid ND * (2) Malonic acid "(3) Malic acid" 35 (4) Oxalic acid " (5) Maleic acid "(6) Tartaric acid" * 18 (7) Aspartic acid "(8) Citric acid" (9) Glycine "(10) Alanine” 05 (11) Sodium succinate "(12) Sodium formate "(13) Sodium acetate" (14) Sodium tartrate "(15) Sodium citrate” XO (16) Sodium glycolate "(17) Sodium tetrahydroxysuccinate" * ND = Not detectable (residual activity less than 10%) .

15 Composition G (with glycerine / borax / Percent of activity of carboxylic acid type), enzymatic after the compound of carboxylic acid - 7 days at 43 ° C.

that being one of the following: _ (1) Sodium succinate 60 20 (2) Succinic acid 94 (3) Malonic acid 91 (4) Malic acid 79 (5) Oxalic acid 81 (6) Maleic acid 88 25 (7 ) Tartaric acid 63 (8) Aspartic acid 84 (9) Citric acid 62 (10) Glycine 80 (11) Alanine 79 30 (12) Sodium formate 57 (13) Sodium acetate 50 (14) Sodium tartrate 54 (15 ) Sodium citrate 57 (16) Sodium glycolate 50 35 (17) Sodium tetrahydroxy-succinate 61

As can be seen from Table II, the Com-

V

At position A, the control composition, as well as Compositions B and C which contain glycerin and borax, respectively, as well as individual stabilizers, show almost no matic enzy-05 activity after the period of 7 days of storage at 43 ° C. Since enzyme activities below 10% cannot be measured accurately, they are referred to as "ND". Composition D containing glycerin / borax in the absence of compound 10 of carboxylic acid type shows an improvement in enzymatic stability compared to Compositions A, B and C, but more than 50% of the enzyme are deactivated. vés. The various Compositions E containing various compounds of the carboxylic acid type, as indicated, show absolutely no improvement in the enzymatic stability with respect to Compositions A, B and C. However, Compositions G formulated according to the invention exhibit the unexpected and synergistic improvement in enzyme stability, which is achieved by using a combination of glycerin / borax and a carboxylic acid compound in the liquid detergent compositions of the invention. It is noted that among the 17 compositions corresponding to Composition G tested, the enzymatic activity is improved compared to Composition D (containing glycerin and borax).

A comparison of the enzymatic activity obtained with Compositions D (glycerin / borax) and the various Compositions F (borax / compound of carboxylic acid type) and G (formulated according to the invention) is indicated below in Table III.

c 20

TABLE III ENZYMATIC STABILITY

Percentage of activity

Enzymatic composition at the end

05 _-: · from 7 days to 43 ° C

D (glycerin / borax) 45 F (borax / malonic acid) 13 G (glycerin / borax / malonic acid) 91 F (borax / aspartic acid) 39 10 G (glycerin / borax / aspartic acid) 84 F (borax / citric acid) ) ND * G (glycerin / borax / citric acid) 62 ND = not detectable (residual activity less than 15 10%).

As shown in Table III, the various compositions G containing a three-component stabilizing system according to the invention offers a synergistic improvement in enzyme stability compared to Compositions D and F formulated according to the prior art.

Claims (22)

21 1. Reinforced liquid stabilized detergent composition containing enzymes, characterized in that it comprises: 05 (a) approximately 5 to 20% by weight of one or more detergent surfactant compounds chosen from anionic, nonionic detergent compounds and ampho-tères; (b) about 5 to 30% by weight of one or more adjuvant detergency salts selected from alkali metal tripolyphosphates, alkali metal carbonates, alkali metal nitrilotriacetates and polyacetal carboxylates; (c) an effective amount of an enzyme or mixture of enzymes selected from alkaline enzymes of the protease and alphaamylase type; (d) an enzyme stabilization system containing, based on the weight of the detergent composition, (i) about 1 to 10% glycerin; (ii) approximately 20 1 to 8% of a boron compound chosen from boric acid, boric oxide and alkali metal borates and (iii) approximately 0.5 to 8% of a compound of the type carboxylic acid chosen from mono-, di- and / or polycarboxylic acids of 1 to 8 carbon atoms and their water-soluble salts; and (e) the remainder consisting of water and optionally of perfume and other additives. 2. Liquid detergent composition according to claim 1, characterized in that it comprises: i (a) about 5 to 15% of an alkali metal alkylbenzene sulfonate in which the alkyl group has from 12 to 15 carbon atoms ; (b) about 2 to 5% of an alkali metal alkyl polyethoxy sulfate in which the alkyl group has from 10 to 18 carbon atoms and the polyethoxy chain has from 3 to 11 ethylene oxide groups, the ratio by weight from (a) to (b) being from about 2: 1 to about \ 22 " 3. Liquid detergent composition according to claim 2, characterized in that the alkali metal alkylbenzene sulfonate is sodium (linear tridecyl) benzene sulfonate and the alkali metal alkyl polyethoxy sulfate is a sulfate of this type in which the alkali metal is sodium, the alkyl group contains from 12 to 15 carbon atoms and the polyethoxy chain has about 3 ethylene oxide groups. 4. Liquid detergent composition according to claim 3, characterized in that the ratio of tridecylbenzene sulfonate to polyethoxysulfate is from about 3: 1 to about 5: 1. 5. A liquid detergent composition according to claim 2, characterized in that the boron compound is an alkali metal borate. 6. Liquid detergent composition according to claim 5, characterized in that the borate is borax. 7. Liquid detergent composition according to claim 2, characterized in that it contains approximately 10 to 16% of sodium tripolyphosphate and approximately 3 to 7% of sodium carbonate. T * 23 8. Liquid detergent composition according to claim 2, characterized in that the compound of carboxylic acid type is succinic acid or a water-soluble salt of this acid. 8. X; (c) about 5 to 20% sodium tripolyphosphate; (d) about 1 to 10% sodium carbonate, the weight ratio of (c) to (d) being from about 2: 1 to about 6: 1; * (e) an effective amount of said enzyme or mixture of enzymes? (f) the enzyme stabilizing system containing, based on the weight of the detergent composition, (i) about 3 to 7% glycerin, (ii) about 1 to 5% of an alkali metal borate and (iii ) about 0.5 to 4% of said compound of carboxylic acid type; and (g) the remainder consisting of water and optionally 15 minor additives. 9. Liquid detergent composition according to claim 2, characterized in that the compound of carboxylic acid type is maleic acid or a water-soluble salt of this acid. 10. Liquid detergent composition according to claim 2, characterized in that the compound of carboxylic acid type is citric acid or a water-soluble salt of this acid. 11. Liquid detergent composition according to claim 2, characterized in that the compound of carboxylic acid type is malonic acid or a water-soluble salt of this acid. 12. A liquid detergent composition according to claim 2, characterized in that the compound of carboxylic acid type is malic acid or a water-soluble salt of this acid. 13. A laundering process, characterized in that it consists in bringing the stained and / or soiled fabrics to be washed into contact with a stabilized reinforced liquid detergent composition containing enzymes, comprising: (a) about 5 t 20% by weight of one or more surfactant detergent compounds chosen from anionic, nonionic and amphoteric detergent compounds; (B) about 5 to 30% by weight of one or more adjuvant detergency salts chosen from tripo-lyphosphates of alkali metals, carbonates of alkali metals, nitrilotriacetates of alkali metals and polyacetal carboxylates; (C) an effective amount of an enzyme or mixture of enzymes selected from alkaline enzymes of the protease and alpha-amylase type; 24 (d) a system for stabilizing fairytale-contenari-fc enzymes, based on the weight of the detergent composition, (i) about 1 to 10% of glycerin, (ii) about 1 to 8% of a compound boron selected from boric ac-05, boric oxide, and alkali metal borates; and (iii) about 0.5 to 8% of a compound of carboxylic acid type chosen from mono-, di- and / or polycarboxylic acids of 1 to 8 carbon atoms and their water-soluble salts; and (e) the remainder consisting of water and possibly perfume and other additives. 14. Method according to claim 13, .. characterized in that the liquid detergent composition comprises; (A) about 5 to 15% of an alkali metal alkylbenzene sulfonate in which the alkyl group has from 12 to 15 carbon atoms; (b) about 2 to 5% of an alkali metal alkylpolyethoxy sulfate in which the alkyl group has from 10 to 18 carbon atoms and the polyethoxy chain has from 3 to 11 ethylene oxide groups, the weight ratio from (a) to (b) being from about 2: 1 to about 8: 1; (c) about 5 to 20% of sodium dium tripolyphosphate; (d) about 1 to 10% sodium carbonate, the weight ratio of (c) to (d) being from about 2: 1 to about 6: 1; (e) an effective amount of said enzyme or said mixture of enzymes; (f) the enzyme stabilization system containing, based on the weight of the detergent composition, (i) about 3 to 7% glycerin, (ii) about 1 to 5% of an alkali metal borate and (iii ) about 0.5 to 4% of said carboxylic acid compound; and (g) the balance consisting of water and optionally 4 minor additives. 15. The method of claim 14, characterized in that the alkali metal alkylbenzene sulfonate is sodium (linear tridecyl) benzene sulfonate and the alkali metal alkylpolyethoxy sulfate is a sulfate of this type in which the alkali metal is sodium, the alkyl group has 12 to 15 carbon atoms and the polyethoxy chain has about 3 ethylene oxide groups. 16. The method of claim 15, characterized in that the ratio of tridecylbenzene sulfonate to polyethoxy sulfate is from about 3: 1 to about 5: 1. 17. The method of claim 14, 15 characterized in that the boron compound is borax. 18. The method of claim 14, characterized in that the liquid detergent composition contains about 10 to 16% of sodium tripolyphosphate and about 3 to 7% of sodium carbonate. 19. Method according to claim 14, characterized in that the compound of carbo-xylic acid type is succinic aid or a water-soluble salt of this acid. 20. The method of claim 14, characterized in that the carbo-xylic acid compound is citric acid or a water-soluble salt of this acid. 21. The method of claim 14, characterized in that the carbo-xylic acid compound is maleic acid or a water-soluble salt of this acid. 22. Method according to claim 14, characterized in that said compound of carboxylic acid type is malonic acid or a water-soluble salt of this acid.