LU85391A1 - SINGLE-PHASE, STABILIZED LIQUID DETERGENT COMPOSITION WITH DETERGENT ADJUVANT AND CONTAINING ENZYMES, AND WASHING METHOD USING THE SAME - Google Patents

Description

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The present invention relates to stable liquid detergent compositions containing one or more enzymes and a detergency builder / suitable for leaching or pre-soaking formulations. More particularly, the invention relates to aqueous liquid detergent compositions, containing enzymes, which contain a non-phosphate detergency builder and which are characterized as being homogeneous, single-phase, clear and physically stable liquid compositions. .

The formulation of liquid detergent compositions containing stabilized enzymes has constituted in the prior art a particular center of interest. The desire to incorporate enzymes into detergent compositions is mainly due to the effectiveness of the proteolytic and amylolytic enzymes in breaking down protein and starchy materials found on soiled fabrics, so as to facilitate the removal of stains, for example sauce stains, blood stains, chocolate stains, etc., during the laundering operation. However, enzyme materials suitable for bleaching compositions, particularly proteolytic enzymes, are relatively expensive. In fact, they generally constitute the most expensive ingredient of a commercial liquid detergent composition, even when they are present in relatively minor amounts. In addition, it is known that enzymes are unstable in aqueous com-1 positions. This is the reason why liquid detergent formulations generally require an excess of enzyme in order to compensate for the expected loss of w 2 \ enzyme activity during extended periods of storage. Consequently, the prior art abounds with proposals aimed at stabilizing the liquid detergent compositions containing enzymes, and in particular the liquid compositions without detergency builder. the use of various substances which are incorporated into the compositions and which serve as enzyme stabilizers.

In the case of liquid detergent compositions containing a detergency builder, the problem of enzyme instability is particularly acute. First of all, this is due to the fact that detergency builders have a destabilizing effect on enzymes, even in compositions containing enzyme stabilizers which are otherwise effective in formulations without detergency builders. In addition, the incorporation of a detergency builder into a liquid detergent composition poses another problem, namely the ability to form a stable single-phase solution, the solubility of sodium tripolyphosphate, for example, being relatively limited in aqueous compositions, and in particular in the presence of anionic and nonionic detergents. Thus, for example, British Patent Application No. 2,079,305 of January 20, 1982 describes an aqueous liquid detergent composition, with detergency builder, containing enzymes, which is stabilized by a mixture of a polyol and boric acid. The compositions described in the examples, however, instead of being stable, clear, single-phase solutions, are cloudy suspensions which are susceptible to separation after prolonged periods of storage. Therefore, the problems of enzyme stability and physical product stability are still problems to be overcome! go up in the formulation of a detergent composition

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t k 3 commercially acceptable.

The present invention relates to a liquid, aqueous, stabilized detergent composition with adjuvant, single phase and containing one or more enzymes, comprising: (a) about 3 to ΙΟ X by weight of a surfactant nonionic detergent compound ; (b) about 3 to 15% by weight of a surface-active amphoteric detergent compound; (C) about 5 to 25% by weight of a detergency builder salt of the non-phosphate type; (d) an effective amount of an enzyme or mixture of enzymes selected from the group consisting of alkaline proteases and alpha-amylases; (E) about 3 to 15% by weight of an enzyme stabilization system consisting essentially of (i) glycerin and (ii) a boron compound selected from the group comprising boric acid, boric oxide and alkali metal borates, capable of reacting with glycerin; and (f) about 30 to 85% by weight of water.

According to the process of the invention, the leaching of stained and / or soiled materials is carried out by bringing these materials into contact with an aqueous solution of the liquid detergent composition defined above. Unlike detergent compositions with adjuvant, containing enzymes, known in the prior art, the compositions of the present invention are solutions whose characteristic is to be transparent, homogeneous, single-phase, and physically stable during prolonged periods of storage and in a wide temperature range. These compositions are preferably substantially free of detergency builder salts of the phosphate type.

The use of a mixture of nonionic and amphoteric surfactant compounds according to the invention allows these surfactants and the detergency builder of the non-phosphate type to be sufficiently dissolved in an aqueous composition of so as to form a homogeneous solution in a single phase. The nonionic detergent compound can constitute about 3 to 10%, preferably about 4 to 8%, of the detergent composition and the ampho-detergent compound generally constitutes about 3 to 15%, preferably about 4 to 10% by weight of this composition. The relative amounts of each of the above detergents are generally determined by the amount of detergency builder salt used. For concentrations of adjuvant of between approximately 5 and 15% by weight of the detergent composition, the amphoteric and nonionic detergents are each present, for example, in a proportion of approximately 4 to 7% by weight, the ratio of amphoteric detergent to nonionic detergent is generally about 1.

For adjuvant concentrations in the range of about 15 to 25% by weight, the amphoteric detergent 20 is present for example in a proportion of about 6 to 10% by weight, and the ratio of amphoteric detergent to non-detergent Ionic is preferably greater than 1, with a ratio of about 1.2 to about 1.6 being particularly desired, the higher ratios generally corresponding to higher concentrations of detergency builder salt.

The enzyme stabilization system according to the invention is a mixture of glycerin and a boron compound chosen from boric acid, boric oxide and an alkali metal borate, capable of reacting with gly- cerine. The weight of the stabilizing system contained in the detergent compositions with adjuvant according to the invention is between approximately 3 and 15, preferably between 4 and 10% by weight. Mixtures of glycerin and borax are particularly advantageous for achieving enzyme stability, the weight ratio of glycerin to borax of these stabilizing mixtures generally being between about 1.2 and 3, a ratio of about 1.5 to 2.5 being preferred. Therefore, the preferred proportion of glycerin in the composition is from about 3 to 7 X, and the preferred proportion of borax is from about 1 to 4 X, based on the weight of the composition.

Alkaline proteolytic enzymes suitable for the compositions of the invention include various commercial liquid enzyme preparations for use in detergent compositions, powdered enzyme preparations also being useful to use, although, in general , they are less convenient to incorporate into liquid detergent compositions with detergency builder.

Thus, suitable liquid enzyme preparations include "Alcalase" and "Esperase" sold by Novo Industries, Copenhagen, Denmark, and "Maxatase" and "AZ-Protease" sold by Gist-Brocades, Delft, Netherlands.

Among the suitable liquid enzymatic preparations of the α-amylase type, mention may be made of 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 corresponding to the detergent compositions with, detergency builder. The synthetic non-ionic and amphoteric detergents used in the practice of the invention can be any of a wide variety of such compounds well known and described in detail in Surface Active Agents, Vol. II, by Schwartz, Perry and Berch, published in 1958 by Interscience Publishers, the relevant descriptions of which are cited for reference in this memoir.

Nonionic detergents are generally polyalkoxylated lipophilic compounds in which the desired hydrophilic-lipophilic ratio is obtained by the addition of a hydrophilic poly (lower alkoxy) group to a lipophilic unit. In the case of the compositions according to the invention, the nonionic detergent used is preferably a poly (lower alkoxy) higher alkanol in which the alkanol group contains 10 to 18 carbon atoms and in which the number of moles of lower alkylene oxide (of 2 or 3 carbon atoms) is between 3 and 10 12. Among these materials, it is preferred to use those in which the higher alkanol is a higher fatty alcohol of 11 or 12 to 15 carbon atoms which contain 5 to 8 or 5 to 9 lower alkoxy groups per mole. Preferably, the lower alkoxy is the ethoxy group, but in some cases it may be mixed with a pro-poxy group, the latter, if present, generally being a minor constituent (less than 50% ). Examples of such compounds are those in which the alkanol group contains 12 to 15 carbon atoms and which contain approximately (R) 20 7 ethylene oxide groups per mole, for example Neodol 25-7 and Neodol 23-6.5, these products being manufactured by Shell Chemical Company, Inc. The former is a condensation product of a mixture of higher fatty alcohols having on average about 12 to 15 carbon atoms, with about 7 moles of ethylene oxide, and the the latter is a corresponding mixture in which the carbon atom content of the higher fatty alcohol is from 12 to 13 and the number of ethylene oxide groups per mole is on average about 6.5. The higher alcohols are primary alkanols. Other examples of these detergents include Tergitol ^ 15-S-7 and Tergitol 15-S-9, both of which are linear secondary alcohol ethoxylates manufactured by Union Carbide Corporation. The first is a mixed ethoxylation product of a linear secondary alkanol of 11 to 15 carbon atoms with 7 moles of ethylene oxide, "7 and the last is a similar product but containing 9 moles of oxide d ethylene reacted.

Also of interest in the compositions of the present invention are higher molecular weight nonionic compounds, for example Neodol 45-11, which are analogous condensation products of ethylene oxide and higher fatty alcohols, alcohol higher fat having 14 or 15 carbon atoms and the number of ethylene oxide groups per mole being about 11.

These products are also manufactured by Shell Chemical Company. Other useful nonionic detergents are represented by Plurafac B-26 (BASF Chemical Company), the reaction product of a higher linear alcohol and a mixture of ethylene and propylene oxides.

In higher poly (lower alkoxy) alkanols, the best ratio of hydrophilic and lipophilic units 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 50% of this number. The nonionic detergent preferably consists of at least 50% of the preferred ethoxylated alkanols. The higher molecular weight alkanols and various other normally solid and surfactant nonionic detergent compounds can contribute to gelation of the liquid detergent composition and therefore are normally avoided or used in limited amounts in the compositions of the invention, although minor proportions can be used due to their cleaning properties, etc. As regards the preferred and less preferred nonionic detergents, the alkyl groups present are preferably linear, although a certain degree of branching can be accepted, for example on the atom following the terminal carbon atom of the straight chain or two atoms of

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8 provided that this branched alkyl group has a chain length of not more than three carbon atoms. Normally, the proportion of carbon atoms in such a branched configuration is minor, and rarely exceeds 20% of the total content of carbon atoms in the alkyl group. Similarly, although the linear alkyl groups which are terminally linked to the ethylene oxide chains are highly preferable and are considered to provide the optimum combination of detergency, biodegradability and non -gelling, there may be a median or secondary link with ethylene oxide in the chain. In this case, this usually relates to only a small proportion of these alkyl groups, generally less than 20%, but in the case, for example, of the Tergitols ’mentioned above, this proportion may be higher.

Also, when the lower alkylene oxide chain contains propylene oxide, this generally constitutes less than 20%, and preferably less than 10% of said chain.

Amphoteric detergents include higher fatty carbo-xylates, phosphates, sulfates and sulfonates which contain a cationic substituent such as an amino group, which may be quaternized, for example with a lower alkyl group, or an extended chain to the amino group. by condensation with a lower alkylene oxide, for example ethylene oxide. Examples of suitable amphoteric detergents include alkyl beta-amino dipropionates, RN (C ^ H ^ COOM) 2? alkyl beta-amino propionates, RN (H) C2H4COOM; and imidazole derivatives having a long chain and having the general formula: CH0

/ 2S

N CH ~

He I 2

R-C-N-CHoCHo0CHoC00M

/ \ 2 2 2 35 OH CH2C00M * 9

In each of these formulas, R is a hydrophobic acyclic group containing about 8 to 18 carbon atoms and M is a cation neutralizing the charge of the anion.

An anionic detergent may optionally be used in minor amounts to enhance the nonionic and amphoteric detergent compounds of the liquid detergent compositions according to the invention. In general, the amount of anionic detergent is less than about 5% by weight, and preferably less than about 3% by weight of the total composition, due to the limited solubility of these detergents in liquid detergent compositions with builder. The alkylbenzene sulfonates in which the alkyl group contains 10 to 18 carbon atoms have a particularly limited solubility in the compositions according to the invention and, consequently, it is preferable that the present compositions be substantially free of such compounds in order avoid the risk of product phase separation.

The anionic detergents which it is preferred to use here are the alcohols, higher sulfated ethoxylated fats of formula RO (C2H ^ 0) mS03M where R is a fatty alkyl group of 10 to 18 or 20 carbon atoms, m is between 2 and 6 or 8 (and preferably has a value of about 1/5 to 1/2 the number of carbon atoms of R) and M is a cation forming a solubilization salt such as alkali metal, ammonium, lower alkylamino or lower alkanol-amino cation, or a (higher alkyl) benzene sulfonate in which the alkyl group contains 10 to 15 carbon atoms.

Ethylene oxide is the lower alkylene oxide which is preferred for the detergent of the anionic alkoxylate type, and its proportion in the polyethoxylated (higher alkanol) sulfate is preferably from 2 to 5 moles of ethylene oxide groups per mole of anionic detergent,

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10 particular when the higher alkanol has 11 or 12 to 15 carbon atoms. In order to maintain the desired hydrophilic-lipophilic ratio, when the carbon atom content of the alkyl chain is in the lower part of the range of 10 to 18 carbon atoms, the ethylene oxide content of the detergent can be reduced to about 2 moles per mole, while when the higher alkanol has 16 to 18 carbon atoms and is present. at the top of the range, the number of ethylene oxide groups can be increased to 4 or 5 and, in some cases, up to 8 or 9. Similarly, the salt-forming cation can be changed to obtain the best solubility. It can be any suitable metal or solubilization radical, but it is most often an alkali metal, for example sodium, or ammonium.

”If lower alkyl or alkanolamine groups are used, the alkyl and alkanol groups generally have 1 to 4 carbon atoms, and the amines and alkanolamines can be mono-, di- and trisubstituted, for example monoethanolamine, diisopropanolamine and trimethylamine. A preferred polyethoxylated detergent alcohol sulfate is available from Shell Chemical Company and marketed as Neodol 25-3S.

The phosphate-free detergency builder salts are used in the compositions of the present invention in proportions of between about 5 and 25%, and preferably about 10 to 20% by weight. Particular examples of water-soluble mineral phosphorus-free detergency builders include carbonates, bicarbonates and water-soluble mineral silicates. Particular preference is given here to carbonates, bicarbonates and silicates of alkali metals, for example sodium and potassium.

Water soluble organic builders are also useful and include polyacetates, carboxylates, polycarboxylates and polyhydroxysulfonates of alkali metals, ammonium and substituted ammonium. Particular examples of polyacetates and polycarboxylates used as detergency builders include the sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylene diaminetetraacetic acid, nitri-lotriacetic acid, benzene polycarboxylic acids (c (i.e., penta- and tetra-), carboxymethoxysuccinic acid and citric acid.

The proportions of water, the main solvent of the compositions of the present invention, are generally from about 30 to 85%, preferably from 45% to 75%, and more preferably from about 60 to 70% by weight of the composition li-i quide.

| The optical brighteners used in liquid detergent compositions are "important constituents of current detergent compositions which impart a shiny appearance to laundry and washed materials, so that the laundry is not only clean, but also gives an impression of cleanliness.

Although it is possible to use a single optical brightener for a particular purpose in the liquid detergent compositions of the invention, it is generally desirable to use mixtures of brighteners which exert effects. satisfactory brighteners on co-ton, "Nylons", polyesters and blends of these materials and which are also stable towards the bleaching agent. A suitable description of these types of optical brightening agents can be found in the article "The Reqnirements of Present Day Detergent Fluorescent Whitening 30 Agents" by AE Siegrist, J. Am. Oil Chemists Soc., January v 1978 (volume 55 ). This article and US Patent 3,812,041 of May 21, 1974 which are cited by reference contain detailed descriptions of a wide variety of suitable optical brightening agents.

Among the brightening agents useful in the liquid detergent compositions of the present invention, there may be mentioned: Calcofluor 5BM (American Cyanamid); "Tinopal LPW (Ciba); SOP A-2001 (Ciba); CDW (Hilton-Davis); Phorwite RKH, Phorwite BBH and Phorwite BHC (Verona); 5 CSL, powder, acid (American Cyanamid); PB 766 (Verona) ; Blancophor PD (GAF); UNPA (Geigy); Tinopal RBS 200 (Geigy).

Liquid detergent compositions can contain adjuvants intended to impart additional functional or aesthetic properties. Useful additives include suspending or anti-deposition agents, for example polyvinyl alcohol, sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose and thickeners, for example gums, alginates, agar; foam enhancing agents, for example lauric-myristic diethanolamide; foam destroyers, for example silicones; bactericides, for example tribromosalicylanilide, hexachlorophene; dyes; pigments (dispersible in water); preservatives; ultraviolet light absorbers 20; fabric softeners; opacifiers, for example polystyrene suspensions; and perfumes. Naturally, these materials will be chosen on the basis of the properties desired for the finished product, their compatibility with the other constituents, and their solubility in the liquid composition.

The liquid compositions of the invention are effective and easy to use. Compared to detergent powders for washing coarse laundry, much smaller volumes of the liquids of the invention are used - to achieve comparable cleaning of soiled laundry. For example, using a typical preferred formulation of the present invention, only 132 g or half a cup of liquid is required for a full tub of an automatic top-loading washing machine in which the 1 13 i! i water volume is 55 to 75 liters; and even less for front loading machines. Thus, the concentration of the liquid detergent composition in the washing water is of the order of about 0.2%. In general, the proportion of liquid composition in the washing solution is between about 0.05 and 0.3%, preferably between 0.15 and 0.25%. The proportions of the various constituents of the liquid composition can vary correspondingly. Equivalent results can be obtained by using higher proportions of a more dilute formulation, but the larger amount required will require additional packaging and will generally be less convenient for the user.

Example 1.

The liquid detergent compositions A-F containing an enzyme, with detergency builder, are formulated as indicated below in Table I. The percentages indicated represent percentages by weight.

TABLE I

20 A B Ç D E F ~

Primary alcohol ethoxylated in ci2 ~ c15 (7 moles 0E ° / mole of alcohol) 5.5% 5.5% 5.5% 5.5% 5.5% 5.5%

Varion CADG ^ 1 ^ 21 21 21 21 21 21 25 Brightening agent 0.2 0.2 0.2 0.2 0.2 0.2 0.2

Sodium nitrilotriacetate 15 15 15 15 15 15 PBB (2) 111111

Perfume 0.3 0.3 0.3 0.3 0.3 0.3 (3) 30 Proteolytic enzyme 1 1 1 1 1 1, Glycerin - 5 5 5 5 -

Borax. - 12 3 - 3 E ^ O ------------- the rest --------------

Percentage of enzyme activity after 5 12 62 73 76 21 28

days at 43 ° C A

14 (1) A 32% aqueous solution of copra-amido-betaine sold by Sherex Chemical Company.

5 (2) Polar Brilliant Blue - a 1% solution of active dye.

5 (3) "Esperase" sold by Novo Industries containing 5% of enzyme, 75% of propylene glycol, the remainder consisting of H2O having an activity of 8.0 KNPU / g (kilo-units of Novo Protease / g).

0 Ethylene oxide.

The enzymatic activity of the AF compositions is tested after 6 days of storage at 43 ° C., the percentage of activity relative to the initial value being indicated in Table I. Compositions A, E and F are the only ones compositions which do not contain an enzyme stabilization system according to the invention, and which show an almost total loss of enzymatic activity after 6 days. Compositions B, C and D reflect the marked improvement in enzyme stability attributed to the incorporation of glycerin and borax into the detergent composition.

The compositions A to F are all homogeneous transparent solutions with a single phase which retain their physical stability and their transparency after 6 months of storage at room temperature and at 43 ° C.

25 Example 2.

* Liquid detergent compositions G and H

containing an enzyme and a detergency builder are formulated essentially like compositions A to F, with the difference that sodium citrate is used as a detergency builder salt in place of the NTA (nitrilotriaceous * täte). sodium. The compositions are indicated below in Table II.

! (15

TABLE II

G H

'' Primary alcohol ethoxylated in ci2 ~ cl5 (7 moles EO / mole of alcohol) 5.5¾ 5.5¾ 5 Varion CADG * 1 * 21 21

Brightening agent 0.2 0.2

Sodium citrate 13 33 PBB ^ 1 1

Perfume 0.3 0.3 (3) 10 Proteolytic enzyme 1 1

Glycerin - 5

Borax - 3 H2O —the rest ---

Percentage of enzyme activity after 15 days at 43 ° C 26 95 * (1) A 32% aqueous solution of copra-amido-betaine sold by Sherex Chemical.

(2) Polar Brilliant Blue - a 1% solution of active dye.

20 (3) "Esperase" sold by Novo Industries containing 5% of enzyme, 75 ¾ of propylene glycol, the rest being H2O having an activity of 8.0 KNPU / g (kilo-units of Novo Protease / g).

Composition H according to the invention manifests an enzymatic activity after 6 days of 95%, compared with composition G which does not contain an enzyme stabilizing system and loses almost three-quarters of its enzymatic activity.

The compositions are clear, single-phase solutions which remain physically stable after six months of storage at room temperature and at

43 ° C. I

Claims (19)

1. A liquid, stabilized, clear, single-phase liquid detergent composition containing one or more enzymes and charged with an adjuvant, characterized in that it comprises: (a) approximately 3 to 10% by weight of a nonionic surfactant detergent compound, - (b) about 3 to 15% by weight of an amphoteric detergent surfactant compound; (C) about 5 to 25% by weight of a non-phosphate type water-soluble detergency builder salt; (d) an effective amount of an enzyme or mixture of enzymes selected from the group consisting of alkaline proteases and alpha-amylases; (E) about 3 to 15% by weight of an enzyme stabilization system consisting essentially of (i) glycerin and (ii) a boron compound selected from boric acid, boric oxide and borates of alkali metals, capable of reacting with glycerin; and 20 (f) about 30 to 85% by weight of water. 2. A detergent composition according to claim 1, characterized in that said nonionic detergent compound is a water-soluble C 1 -C 4 alkanol comprising one or more C 2 -C 3 alkoxy groups * 3. Detergent composition according to claim 1, characterized in that said detergency builder salt is sodium citrate. 4. Detergent composition according to claim 1, characterized in that said detergency builder salt is sodium nitrilotriacetate. 5. Detergent composition according to claim 1, characterized in that it contains less than approximately 5 X by weight of an anionic surfactant detergent compound. 6. Detergent composition according to claim 35 1, characterized in that it is substantially free of w 17 anionic detergent of the type (C ^ 0 ~ C ^ g alkyl) benzene-tallow ona te. 7. A detergent composition according to claim 1, characterized in that said boron compound is an alkali metal boor. 8. Detergent composition according to claim 7, characterized in that it contains approximately 3 to 7% by weight of said glycerin and approximately 1 to 4% by weight of said alkali metal borate. 9. detergent composition according to claim 1, characterized in that it is substantially free of adjuvant salt of phosphate type detergency. 10. A detergent composition according to claim 1, characterized in that said alkali metal borate is borax. 11. Detergent composition according to claim 1, characterized in that said detergency builder salt is present in a proportion of about 10 to 20% by weight. 12. Washing method, characterized in that it consists in bringing the stained and / or soiled fabrics to be washed into contact with a liquid detergent composition with a single phase, clear, with adjuvant and containing one or more enzymes, comprising: (a) about 3 to 10% by weight of a surface-active nonionic detergent compound; (b) about 3 to 15% by weight of a surfactant amphoteric detergent compound; (c) about 5 to 25% by weight of a water-soluble detergency builder salt, of the non-phosphate type; (D) an effective amount of an enzyme or a mixture of enzymes chosen from alkaline proteases and alkaline alpha-amylases; (e) about 3 to 15% by weight of an enzyme stabilization system consisting essentially of (i) glycerin and (ii) a boron compound selected from boric acid, boric oxide and borates of alkali metals, capable of reacting with said glycerin? and 18 "te (f) about 30 to 85% by weight of water. 13. The method of claim 12, character ized in that the nonionic detergent compound is a C ^ q_c ^ 8 alkanol having one or more C2-C3 alkoxy groups * 14. The method of claim 12, character-ized in that said composition contains less than about 5. by weight of an anionic surfactant detergent compound. 15. The method of claim 12, characterized in that said composition is substantially free of anionic detergent of the type (C ^ O-C ^ alkyl) benzene sulfonate. - 16. The method of claim 12, character ized in that the boron compound is an alkali metal borate. 17. The method of claim 16, character-ized in that said composition contains about 3 to 7% by weight of said glycerin and about 1 to 4% by weight of said alkali metal borate. 18. The method of claim 12, characterized in that said alkali metal borate is borax. 19. The method of claim 12, characterized in that the detergency builder salt of the phosphate-free type is present in the composition in an amount of about 10 to 20% by weight.