US3600318A - Enzyme-containing detergent compositions for neutral washing - Google Patents

Abstract

ENZYME-CONTAINING DETERGENT COMPOSITIONS ADAPTED FOR USE UNDER NEUTRAL AND NEAR-NEUTRAL CONDITIONS OF PH ARE DISCLOSED. THE DETERGENT COMPOSITIONS CONSIST ESSENTIALLY OF A SYNTHETIC ORGANIC DETERGENT CHARACTERIZED BY SOLUBILITY IN WATER OF AT LEAST 0.05% AT ABOUT 80*F. TO ABOUT 130* F., EFFICIENT SOIL-REMOVING AND SOIL-DISPERSING PROPERTIES IN WATER IN AN AMOUNT OF ABOUT 0.05%, RESISTANCE TO PRECIPITATION BY HARD WATER MINERAL IONS; 0.001% TO 10% OF A PROTEOLYTIC ENZYME CHARACTERIZED BY PROTEOLYTIC ACTIVITY UP TO ABOUT 130*F. IN THE PH RANGE OF FROM 6 TO 8.5; AND A PROTEOLYTIC ENZYME-STABLIZING NEUTRAL INORGANIC ELECTROLYTE SALT.

Description

3,600,318 ENZYME-CONTAINING DETERGENT COMPOSI- TIONS FOR NEUTRAL WASHING Roy C. Mast, Colerain Township, Hamilton County, Ohio,

assignor to The Procter & Gamble Company, Cincinnati, Ohio No Drawing. Continuation-impart of application Ser. No. 737,301, June 17, 1968. This application June 2, 1969, Ser. No. 829,787

Int. Cl. Clld 7/18, 7/56 US. Cl. 252-99 17 Claims ABSTRACT OF THE DISCLOSURE Enzyme-containing detergent compositions adapted for use under neutral and near-neutral conditions of pH are disclosed. The detergent compositions consist essentially of a synthetic organic detergent characterized by solubility in water of at least 0.05% at about 80 F. to about 130 F., efficient soil-removing and soil-dispersing properties in water in an amount of about 0.05%, resistance to precipitation by hard water mineral ions; 0.001% to 10% of a proteolytic enzyme characterized by proteolytic activity up to about 130 F. in the pH range of from 6 to 8.5; and a proteolytic enzyme-stabilizing neutral inorganic electrolyte salt.

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of the copending patent application of Roy C. Mast, Ser. No. 737,301, filed June 17, 1968 and now abandoned.

FIELD OF THE INVENTION This invention relates to cleansing and laundering compositions particularly adaptable to use under neutral or near-neutral conditions of pH. More particularly, it relates to neutral or near-neutral detergent compositions containing a detergent material, a proteolytic enzyme, and an electrolyte which provide superior levels of cleaning and whitening heretofore unattainable under the neutral or near-neutral washing conditions hereinafter defined.

The use of enzymes in admixture with detergent compositions is known and is described, for example, in US. Pat. 1,882,279, issued Oct. 11, 1932. Similarly, British Pat. 814,772, issued June 10, 1959, German Pat. 14,296 published Jan. 6, 1958 and laag in Seifen, Ole, Fctte, Wachse 88, No. 24, pp. 789-793 (November 1962) disclose enzyme-containing detergent compositions. Proteolytic enzymes aid the cleaning process by degrading or otherwise altering proteinaceous stains and rendering them more easily removable by the dctersive action of a detergent compound. In addition, their degradative action serves to digest or break down proteinaceous materials which serve as binding agents for non-digestible soils.

Various attempts have been made in the art to formulate enzyme-containing detergent compositions incorporating an enzyme material having suitable compatibility with synthetic detergents and appreciable proteolytic activity. These attempts have frequently involved the formulation of detergent compositions having the high alkalinity believed to permit the most efiicient use of conventional 3,600,318 Patented Aug. 17, 1971 "ice organic detergents. Moreover, these attempts have often involved the employment of appreciable amounts of inorganic phosphorus-containing builders, e.g. sodium tripolyphosphate or pyrophosphate and have been characterized by high alkalinity in aqueous solution, e.g., pH 9 to 12. While these highly alkaline enzyme-containing detergent compositions provide high levels of cleaning, including efiicient stain-removing properties, the washing of laundry under neutral or near-neutral conditions of pH is attendant with certain decided advantages over washing under the alkaline conditions of pH normally encountered in the use of conventional, heavy-duty laundry detergent formulations.

One advantage of neutral or near-neutral washing is the substantial avoidance of the formation and precipitation of insoluble salts or complexes normally encountered under alkaline conditions, e.g., at about pH 9 or greater, by the reaction of metal ions in wash wat c.g., calcium ions, with the fatty acid components of lipid soils. The washing of textile materials under neutral or near-neutral conditions greatly minimizes the formation of these scum deposits which contribute to an overall poor appearance of laundered materials. Moreover, it eliminates the need for scum dispersers conventionally employed in the art to alleviate the problems inherent in the formation of such deposits.

Another advantage to neutral or near-neutral washing is the elimination of the formation of mineral deposits by the reaction of alkaline components normally encountered in heavy-duty laundering compositions with the metal ions present in the washing solution. These deposited inorganic metal salts weaken laundered fabrics, particularly at those areas of the fabric which are exposed to frictional and creasing effects, such as collars and cuffs, resulting in a loss of useful life and impart harshness or poor hand to the laundered fabrics. In addition to these advantages, the employment of neutral or near-neutral washing compositions in the cleansing of textile materials, greatly reduces the corrision of metal parts in washing machines frequently encountered in connection with the employment of washing solutions characterized by high alkalinity.

While neutral or near-neutral washing conditions are to be preferred from many standpqints, the cleaning levels attainable in the laundering of textile materials have not been entirely satisfactory and have generally been inferior to those attainable by laundering textile materials under conditions of alkalinity such as are normally encountered in the use of conventional heavy-duty built anionic detergent formulations.

A desirable advantage of neutral or near-neutral detergent formulations of efiicient cleaning capacity is that the presence of the phosphorus-containing builder compounds normally employed in alkaline detergent compositions can be effectively eliminated. Their elimination i om detergent compositions with retention of efficient cleaning characteristics is a decided advantage.

OBJECTS OF THE INVENTION attainment of su erior levels of cleaning under neutral or near-neutral washing conditions.

Other objects of the present invention will become apparent from a consideration of the invention which is described in detail hereinafter.

SUMMARY OF THE INVENTION This invention is based on the discovery that detergent composition comprising a proteolytic enzyme and certain critical detergent components permit the attainment of superior levels of cleaning attained heretofore only with alkaline detergent compositions. The invention thus involves the preparation of substantially neutral laundry detergent compositions consisting essentially of a combination of essential components. These compositions consist essentially of:

(A) from 10 to 29% of a synthetic organic detergent characterized by:

(1) solubility in water in a concentration of at least 0.05% at a temperature of about 80 F. to about 130 F.;

(2) efficient soil-removing and soil-dispersing properties in a concentration of about 0.05% in water; and

(3) resistance to precipitation by hard water mineral ions; and

(B) from 001 to of a proteolytic enzyme characterized by proteolytic activity up to about 130 F. in the pH range of from 6 to 8.5; said compositions having a pH of from 6 to 8.5 in aqueous solution.

When the synthetic organic detergent is an anionic or ampholytic detergent as hereinafter described, a proteolytic enzyme-stabilizing neutral inorganic electrolyte salt is employed.

DETAILEI DESCRIPTION OF THE INVENTION The organic detergents which find applicability in the preparation of detergent formulations etfective in neutral or near-neutral laundering include anionic, nonionic, zwitterionic and ampholytic detergents and mixtures thereof having certain desirable properties. These properties include superior detergency and dispersancy and relative resistance to precipitation or insoluble complex formation under the conditions of pH and water hardness contemplated herein as neutral or near-neutral washing. As employed herein, the terms neutral or near-neutral (hereinafter termed substantially neutral") washing conditions or compositions contemplate washing conditions or compositions which correspond to pHs in the range of 6 to 8.5. The terms detergency and dispersancy where employed herein refer, respectively, to the capacity to remove particulate and lipid soils from a substrate and the capacity to keep in suspension in a washing solution the particulate and lipid soils removed from a substrate by detersive action. Detergent and dispersant compounds utilizable herein must, in addition, perform satisfactorily in washing solutions containing hard water mineral ions without forming a precipitate or non-detergent insoluble complex. Where a detergent and dispersant material forms such a precipitate or insoluble-complex with hard water ions, the material is rendered into a relatively useless form and thereby does not function in its intended manner. A suitable detergent and dispersant material for use herein will be one which does not form the hereinbefore described undesirable mate ials in tap water of normal hardness.

It has been found quite unexpectedly that superior levels of cleaning and whitening which heretofore have been attainable only under alkaline laundering conditions can be attained under substantially neutral washing conditions by employing a composition which consists essentially of a highly efficient synthetic organic detergent havin the hereinbefore described properties in combination with a proteolytic enzyme material and a neutral electrolyte material.

Suitable synthetic organic detergent compounds herein include water-soluble salts of sulfonated fatty acid esters; water-soluble salts of fi-ac',loxyalkane-l-sulfonic acids, water-soluble alkyl ether sulfates; water-solule olefin sulfonates; tertiary phosphine oxides; and certain a1 pholytic and zwitterionic detergents. Of the organic detergents investigated, only detergents more specifically described hereinafter have been found in the compositions of the present invention to provide, under substantially neutral conditions, levels of cleaning which equal or surpass those normally attained in the course of washing with a conventional alkaline detergent composition. It will be appreciated that mixtures of these detergent materials can be employed to advantage.

Anionic organic detergents utilizable herein include alkali metal, ammonium and substituted-ammon um salts of esters of an u-sulfonated fatty acid in which the esters contain from 15 to 25 carbon atoms. These detergent compounds have the following structure:

wherein R, is alkyl or alkenyl of from 10 to 20 carbon atoms (forming with the two carbon atoms a fatty acid group); R is alkyl of 1 to 10 carbon atoms; and M is a salt-forming radical.

The salt-forming radical M in the hereinbefore described structural formula is a Water-solubilizing cation and can be, for example, an alkali metal cation (e.g., sodium, potassium, lithium), ammonium or sub iituted-ammonium cation. Specific examples of substituted-ammonium cations include methyl-, dimethyl-, and trimethylammonium cations and quaternary ammonium cations such as tetramethyl-ammonium and dimethyl pipeidinium cations and those derived from alkylamines such as ethylarnine, diethylamine, triethylamine, mixtures thereof, and the like.

Specific examples of this class of compounds include sodium and potassium salts of esters where R is selected from methyl, ethyl, propyl, butyl, hexyl and octyl groups and the fatty acid group (R plus the two carbon atoms in the structure above) is selected from lauric, myristic, palmitic, stearic, palmitoleic, oleic, linoleic acids and mixtures thereof. A preferred ester material herein is the sodium salt of the methyl ester of a-sulfonated tallow fatty acid, the term tallow indicating a carbon chain distribution approximately as follows: C .,-2.5%, C 28%, C -23%, palmitoleic2%, oleic4l.5%, and linoleic-3% (the first three fatty acids listed are saturated).

Other examples of suitable salts of a-sulfonated fatty esters utilizable herein include the ammonium and tetramethylammonium salts of the hexyl, octyl, ethyl, and butyl esters of a-sulfonated tridecanoic acid; the potassium and sodium salts of the ethyl, butyl, hexyl, octyl, and decyl esters of a-sulfonated pentadecanoic acid; and the sodium and potassium salts of butyl, hexyl, octyl, and decyl esters of a-sulfonated heptadccanoic acid; and the lithiuma nd ammonium salts of butyl, hexyl, octyl, and decyl esters of a-sulfonated nonadecanoic acid.

The salts of a-sulfonated fatty acid esters of the present invention are known compounds and are described in U.S. Pat. No. 3,223,645, issued Dec. 14, 1965 to Kalberg, this patent being hereby incorporated by reference.

Another class of suitable anionic organic detergents includes salts of p-acyloxy-alkane-l-sulfonic acids. These salts have the formula alkyl of 1 to 8 carbon atoms; and M is a salt-forming radical hereinbefore described.

Specific exr nples of fi-acyloxy-alkane-l-sulfonates, or alternatively 2 acyloxy alkane-l-sulfonates, utilizable herein to provide superior cleaning levels under substantially neutral washing conditions include the sodium salt of fl-acetoxy-tridecane-l-sulfonic acid; the potassium salt of p-propionyloxy-tetradecane-l-sulfonic acid; the lithium salt of fi-butanoyloxy tetradecane-l-sulfonic acid; the sodium salt of B peJtanoyloxy-pentadecane-l-sulfonic acid; the ammonium salt of )8 hexanoyloxy-hexadecanel-sulfonic acid; the sodium salt of fi-acetoxy-hexadecanel-sulfonic acid; the dimethylammonium salt of ,B-hep tanoyloxy-tridecane-l-sulfonic acid; the potassium salt of fl-octanoyloxy-tetradecane-l-sulfonic acid; the dimethylpiperidinium salt of S-nonanoyloxy-tetradecane-l-sulfonic acid; the sodium salt of fi-acetoxy-heptadecane-l-sulfcnic acid; the lithiun salt of B-acetoxy-octadecane-l-sulfonic acid; the dimethylamine salt of B-acetoxy-octadecane-l-sulfonic acid; the potassium salt of S-acetoxynonadecane-l-sulfonic acid; the sodium salt of fl-acetoxyuncosane-l-sulfonic acid; the sodium salt of fl-propionyloxy-docosane-l-sulfonic acid; and isomers thereof.

Preferred fl-acyloxy-alkane-l-sulfonate salts herein are the alkali metal salts of fi-acetoxy-alkane-l-sulfonic acids corresponding to the above formula wherein R is an alkyl of from 12 to 16 carbon atoms, these salts being preferred from the standpoints of their excellent cleaning properties and ready availability.

Typical examples of the above described fl-acetoxy al anesulfonates are described in the literature: Belgian Pat. No. 650,323, issued July 9, 1963, discloses the preparation of certain Z-acyloxy alkanesulfonic acids. Similarly, U.S. Pats. 2,094,451, issued Sept. 28, 1937, to Guenther et al. and 2,086,215, issued July 6, 1937 to DeGroote disclose certain salts of fl-acetoxy alkanesulfonic acid-1. These references are hereby incorporated by reference.

Other sythetic anionic detergents useful herein are alkyl ether sulfates. These materials have the formula from tallow are preferred herein. Such alcohols are reacted with 1 to 30, and especially 6, molar proportions of ethylene oxide and the resulting mixture of molecular species, having, for example, an average of 6 moles of ethylene oxide per mole of alcohol, is sulfated and neutralized.

Specific examples of alkyl ether sulfates of the present invention are sodium coconut-alkyl ethylene glycol ether sulfate; lithium tallow-alkyl triethylene glycol ether sulfate; sodium tallow-alkyl hexaoxyethylene sulfate; and ammonium tetradecyl octaoxyethylene sulfate.

Preferred herein for reasons of excellent cleaning properties and readly availability are the alkali metal coconutand tallow-alkyl oxyethylene ether sulfates having an average of from 4 to oxyethylene moieties. The alkyl ether sulfaies of the present invention are known compounds and are described in U.S. Pat. 3,332,876 to Walker (July 25, 1967) incorporated herein by reference.

Other suitable anionic detergents utilizable herein are olefin sulfonates having from 12 to 24 carbon atoms. The term olefin sulfonates is used herein to mean compounds which can be produced by the sulfonation of aolefins by means of uncomplexed sulfur trioxide, followed by neutralization of the acid reaction mixture under conditions such that any sultones which have been formed in the reaction are hydrolyzed to give the corresponding .chlorinated hydrocarbon, etc., when used in th hydroxy-alkanesulfonates. The sulfur trioxide ma be liquid or gaseous, and is usually, but not necessarily, diluted by inert diluents, for example by liquid S3 liquid form, or by air, nitrogen, gaseous 50:, etc., when used in the gaseous form.

The a-olefins from which the olefin sulfonates are derived are mono-olefins having 12 to 24 carbon atoms, preferably 14 to 16 carbon atoms. Preferably, they are straight chain olefins. Examples of suitable l-olefins include l-dodecane; l-tetradecene; l-hexadecene; l-octadecene; l-eicosene and l-tetraeosene.

In addition to the true alkene sulfonates and a proportion of hydroxy-alkanesulfonates, the olefin sulfonates can contain minor amounts of other materials, such as alkene disulfonates depending upon the reaction conditions, proportions of reactants, the nature of the starting olefins and impurities in the olefin stock and side reactions during the sulfonation process.

A preferred embodiment is the use herein of olefin sulfonates which are described completely in US. Pat. 3,332,880 issued July 25, 1967, to Kessler et al. hereby incorporated by reference.

The nonionic detergents useful in the present invention are semi-polar detergent compounds and include, for example, long chain tertiary phosphine oxides having the structure s wherein R is alkyl, alkenyl or monohydroxyalkyl of from 8 to 18 carbon atoms having from 0 to 10 ethylene oxide moieties and from 0 to l glyceryl moiety and R and 1 are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms. The arrow in the formula is a conventional representation of a semi-polar bond. Examples of suitable phosphine oxides are: dodecylidimethylphosphine oxide, tetradecylidimethylphosphine oxide, tetradecylmethylethylphosphine oxide, 3,6,9-trioxaoctadecyldimethylphosphine oxide, cetyldimethylphosphine oxide, 3-dodecoxy-Z-hydroxypropyldi (Z-hydroxyethyl) phosphine oxide, stearyldimethylphosphine oxide, cetylethylpropylphosphine oxide, oleyl diethylphosphine oxide, dodecylidiethylphosphine oxide, tetradecyldiethylphosphine oxide, dodecyldipropylphosphine oxide, dodecyldi(hydroxymethyl)phosphine oxide, dodecyldi(2-hydroxyethyl) phosphine oxide, tetradecylmethyl-Z-hydroxypropyl phosphine oxide, oleyldimethylphosphine oxide, and Z-hydroxydodecyldimethylphosphine oxide.

Ampholytic synthetic detergents utilizable herein can be broadly described as derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be be straight chain or branched and wherein one of the aliphatic substituents contains from 8 to 18 carbon atoms and one contains an anionic water-solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. These detergents have the formula R, R1I ICHg-R3Zl\l wherein R, is alkyl of from 8 to 18 carbon atoms, R is alkyl of 1 to 3 carbon atoms or is hydrogen, R is alkylene of 1 to 4 carbon atoms, Z is carboxy, sulfonate, sulfate, phosphate or phosphonate and M is a salt-forming cation. Examples of compounds falling within this definition are sodium 3-dodecylaminopropionate; sodium 3 dodecylaminopropane sulfonate; N-alkyltaurines such as the ones prepared by reacting dodecylamine with sodium isothionate according to the teaching of U.S. Pat. 3,658,072; sodium salts of N-higher alkyl aspartic acids such as those produced according to the teaching of US. Pat. 2,438,091; and the products sold under the trade name Miranol and described in U.S. Pat. 2,528,378.

Zwitterionic synthetic detergents of the present invention can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight chain or branched, and wherein one of the aliphatic substituents contains from 8 to 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. A general formula for these compounds is:

wherein R, contains an alkyl, alkenyl, or hydroxyalkyl radical of from 8 to 18 carbon atoms having from to 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety; Y is selected from the group consisting of nitrogen, phosphorus, and sulfur atoms; R is an alkyl or monohydroxy alkyl group containing 1 to 3 carbon atoms; at is 1 when Y is a sulfur atom and 2 when Y is a nitrogen or phosphorus atom, R is an alkylene or hydroxy alkylene or hydroxy alkylene of from 1 to 4 carbon atoms and Z is a radical selected from the group consisting of carboxylate, sulfonate, sulfate, phosphonate, and phosphate groups.

Examples include:

4- N,N-di 2- nydroxyethyl -N-octadecylamrnonio 3 butane-l-carboxylate;

5- S-3 -hydroxypropyl-S-hexadecylsulfonio 3-hydroxypenta ne- 1 sulfate;

3- P,P-dieth yl-P-3,6,9-trioxatetracos anephosphonio] Z-hydroxypropane- 1 phosphate;

3- N,N-dipropyl-N-3-dode coxy2-hydroxypropylammonio -propanel -phosphonate;

3- (N,N-dimethyl-N-hexadecylammonio -propanel-sulfonate;

3- (N,N-dimethyl-N-hexadecylammonio -2-hydroxypropane-1 -sulfonate;

4- [N,Ndi 2-hydroxyethyl -N- Z-hydroxydodecyl) ammonio]-butane-1-carboxylate;

3- S-ethyl-S- 3-dodecoxy-2-hydroxypropyl sulfonio propanel-phosphate;

3- [P,P-dimethyl-P-dodecylphosphonio 1 -propane l-phosphonate;

and S [N,N-di 3 -hydroxypropyl -N-hexadecylammonio] 2-hydroxy-pentanel -sulfate.

Preferred compounds falling within this definition are 3- (N,N dimethyl N hexadecylammonio)propane 1- sulfonate and 3-(N,N-dimethyl-N-hexadecylammonio)-2- hydroxy-propane-l-sulfonate which are preferred for their excellent cool water detergency characteristics.

The alkyl groups contained in said detergent surfactants can be straight or branched, preferably straight, and saturated or unsaturated as desired.

The detergent compounds of the present invention are employed in varying amounts in the enzyme-containing detergent compositions of the present invention. As there will be considerable variation in the strengths of washing solutions employed by different users, i.e., some users may tend to use more or less than others, the requisite amount of detergent compound in the detergent formulation is an amount sufficient to provide superior cleaning and whitening levels under diverse conditions of soiling and usage. The enzyme-containing detergent compositions of the present invention can contain by weight from to 99% of the synthetic organic detergent depending upon the detergent employed. When an anionic or ampholytic detergent is employed herein, the amount of detergent employed is from 10% to by weight of the composition. When a semipolar nonionic or zwitte "ionic detergent is employed, the amount of detergent can range from 10% to 99%. In either case, a preferred amount of detergent is from 20% to 70%.

The enzymes of this invention are solid atalytically active protein materials which degrade or alter one or more types of soil or stains encountered in laundering situations so as to remove the soil or stain from the fabric or object being laundered or make the soil or stain more removable in a subsequent laundering step. Both degradation and alteration improve soil removability. As used herein, enzyme activity refers to the ability of an enzyme to perform the desired function of soil attack and enzyme stability refers to the ability of an enzyme to remain in an active state.

The enzymatic components utilizable herein are those which exhibit their degradative and/or altering effects on proteinaceous soils and stains under the substantially neutral washing conditions contemplated herein, i.e., those which exhibit proteolytic activity in aqueous solutions at pI-ls ranging from 6 to 8.5 and at temperatures of about 50 F. to about 130 F.

While applicant does not wish to be bound by any particular theory or mechanism, it is believed the proteolytic enzymes of the present invention catalyze the hydrolysis of the peptide linkage of proteins, polypeptides and related compounds to free amino and carboxyl grou s and thus break down the protein structure in soil. Suitable proteolytic enzymes for use herein include those materials which are termed in the art neutral proteases. These materials exhibit the peak of their proteolytic activity in the substantially neutral range of pH contemplated herein. Also utilizable herein are proteolytic enzymes known in the art as alkaline proteases. While these materials exhibit their peak enzymatic efiects in slightly alkaline solutions, their activity is still sufiicient in the substantially neutral regions of pH as to render practicable their applicability herein. Preferred are proteolytic enzymes which exhibit their peak of enzymatic activity in the substantialy neutral regions hereinbefore defined.

The amount of proteolytic enzyme employed herein to provide the detergent compositions of the present invention is not critical and is an amount of proteolytic enzyme capable of effecting the degradation of the proteinaceous matter normally encountered in a home laundering situation under the washing conditions contemplated herein, e.g., temperatures of about 50 F. to 130 F. and at pHs of from 6 to 8.5. Normally, the proteolytic enzyme is employed in an amount of from 0.001% to 1091 by weight of the enzyme-containing detergent composition on a pure enzyme basis. Best results in terms of overall cleaning efiicacy and stain-removing properties are attained when the proteolytic enzyme is employed in an amount of from 0.01% to 1%.

The above-described proteases can be utilized in apure form in the preparation of enzyme-containing detergent compositions. Generally, however, powdered commercial enzyme compositions containing these enzymes are utilized herein inasmuch as these compositions are easier to handle and retain their activity for a longer period of time. These commercial compositions are preferred for use herein and contain about 2% to about active neutral and alkaline proteases in combination with inert powdered materials which comprise the remaining 20% to 98%. These powdered materials can comprise inorganic alkali metal salts such as sodium sulfate, sodium chloride, potassium silicate, sodium phosphate, inorganic alkaline earth metal salts such as calcium sulfate, magnesium sulfate, magnesium phosphate and the like; organic components such as non-enzymatic proteins, carbohydrates, organic clays, starches, lipids, color bodies, and the like. Active enzyme content of a commercial product is a result of manuf cturing methods employed and is not critical herein so long as the finished compositions have desired enzymatic soil and stain-removing properties.

The enzymes per se have molecular diameters of from about 30 angstroms to several thousand angstroms. However, the particle diameters of the enzyme powder as utilized herein are normally much larger due to agglomeration of individual enzyme molecules or addition of inert powdered materials or vehicles such as starch, organic clays, sodium or calcium sulfate or sodium chloride, during enzyme manufacture. Enzymes are frequently grown in solution. Such vehicles are added after filtration of such solution to precipitate the enzyme in fine form which is then dried; calcium salts also stabilize some enzymes. The enzyme powders of this invention, including those employee in the examples, are typically fine enough to pass through a Tyler Standard 20 mesh screen ((1.85 mm.) although larger agglomerates are often found. Some particles of commercially available enzyme powders are fine enough to pass through a Tyler Standard 100 mesh screen. Generally a major amount of particles will remain on a 150 mesh screen. Thus, the powdered enzymes utilized herein usually range in size from about 1 mm. to 1 micron, most generally from 1 mm. to 0.01 mm. The enzyme powders o the examples have particle size distributions in these ranges.

The activity of the proteases of the present invention can be readily expressed in terms of activity units, e.g., casein assay activity units. In accordance with the casein assay method of determining proteolytic activity, a solution of the protease to be evaluated is allowed to digest by hydrolysis, a solution of casein substrate at an appropriate pH and temperature. The reaction is stopped by the addition of trichloroacetic acid, the solution is filtered and the color of the filtrate containing the digested casein is developed employing Folin-Ciocalteu phenol reagent. The degree of enzymatic activity is determined by comparing the spectrophotometric response with that of solutions of varying concentrations of reagent grade tyrosine and determining the amount of tyrosine produced. The casein assay method of determining proteolytic activity is well known and a more detailed discussion is found in B. Hagihara et al., J. Biochem. (Tokyo), 45, 185 (1958) and M. Kunitz, J. Gen. Physiol., 291 (1947).

The activities of the proteases of the present invention vary depending largely upon the concentration of neutral and alkaline proteases in the enzymatic composition, upon calcium ion concentration, upon substrate concentration, and upon pH. Pure samples of p1 oteases of the present invention are highly active. For example, a Bacillus subrilis-derived Carlsberg subtilisin employed herein is char acterized by a protease activity unit number on a pure basis of about 7,500,000 units/gram. Commercially available compositions wherein the protease is present in varying amounts with inert filler material or vehicle vary in activity from about 100,000 to about 1,500,000 units/ gram. Similarly, an Xray mutated Bacillus subrilis-derived subtilisin suitable herein is characterized by an activity of about 7,500,000 units/ gram, on a pure basis, while the commercial preparations vary in activity from about 100,000 to about 1,500,000 units/gram.

As described hereinbefore, the amount of protease employed herein in the enzyme-containing detergent compositions of the present invention is from .001% to of the composition on a pure enzyme basis. This amount corresponds to the incorporation into the detergent composition of about 75 to about 750,000 protease activity units/gram of detergent composition. The amount of enzyme required in the formulation of detergent compositions having a desired level of proteolytic activity will vary with the purity and activity level of the enzyme employed. The precise amount can be readily determined by methods known in the art so long as the requisite amount of protease hereinbefore specified is employed.

Specific examples of proteases suitable for use in this invention are trypsin, collagenase, keratinase, elastase, subtilisin, BPN and BPN. Preferred proteases are serine proteases which are active in the substantially neutral pH ranges defined herein and are produced from microorganisms such as bacteria, fungi or mold. The serine proteases which are procured by mammalian systems, e.g., pancreatin, are useful herein.

Preferred proteolytic enzymes herein are those derived from the bacterial organism Bacillus subtilis and termed subtilisins. These materials are preferred from the standpoints of excellent soiland stain-removing properties, desirable temperature stability and activity, and ready availability. Also preferred are those proteases derived from the Streptomyces class of microorganisms.

A preferred subtilisin of the present invention is the Bacillus subrilis-derived Carlsberg strain. The Carlsberg strain employed in accordance with'the present invention is a known subtilisin strain, the amino acid sequence of which is described in Smith et al., The Complete Amino Acid Sequence of Two Types of Subtilisin, BPN and Carlsberg, J. of Biol. Chem., volume 241, Dec. 25, 1966 at page 5974. This subtilisin strain is characterized by a tyrosine to tryptophan ratio of about 13 to l. The above reference including its description of the amino acid sequence of the Carlsberg subtilisin is hereby incorporated by reference.

An X-ray mutated Bacillus subriIis-derived subtilisin constitutes another preferred subtilisin of the present invention. This mutation can "be effected In accordance with U.S. Pat. 3,031,380 issued Apr. 24, 1962 to Minagawa et al. by irradiation of a Bacillus subtilis organism with X-rays. Subsequent treatment in a conventional manner can be employed to result in the preparation of an enzymatic composition. U.S. 3,031,380 describes a process whereby an enzymatic composition is produced by subjecting Bacillus subtilis to X-rays of an intensity corresponding substantially to 24-50 roentgens for an interval of at least half an hour, selecting from the colony thus subjected to X-rays a strain identified by cells having hairless, rough, jagged, spotted and dull white characteristics, separating said strain and placing the separated strain in a culture selected from the group consisting of wheat bran and corn meal, maintaining the culture for a period of at least 40 hours while aerating the culture substantially continuously and drying the culture. The disclosure of U.S. Pat. 3,031,380 is hereby incorporated by reference.

Specific examples of commercial enzyme products and the manufacturer thereof include: Alcalase, Novo Industri, Copenhagen, Denmark; Maxatase, Koninklijke Nederlandsche Gist-En Spiritusfabriek N.V., Delft, Netherlands; Protease B-4000 and Protease AP, Schweizerische Ferment A. G., Basel, Switzerland; CRD- Protease, Monsanto Company, St. Louis, M0,; Viokase. VioBin Corporation, Monticello, 111.; Pronase-P, Pronase-E, Pronase-AS and Pronase-AF all of which are manufactured by Kaken Chemical Company, Japan, Rapidase P-2000, Rapidase, Seclin, France; Takamine, HT proteolytic enzyme 200, Enzyme L-W (derived from fungi rather than bacteria), Miles Chemical Company, Elkhart, -Ind.; Rhozyme P-ll concentrate, Rhozyme PF, Rhozyme J-25, Rohm & Haas, Philadelphia, Pa.; Rhozyme PF and J-25 have salt and corn starch vehicles and are proteases having diastase activity; Ainprozyme 200, Jacques Wolf & Company, a subsidiary of Nopco Chemical Company, Newark, NJ.; Takeda Fungal Alkaline Protease, Takeda Chemical Industries, Ltd, Osaka, Japan; WaIIersteinJQl T-IA, Wallerstein Company, Staten Island, N.Y.; Protin As zbfmawaikasei'xik, Osaka, Japan; and Protease TP (derived from thermophilic Streptomyces species strain 1689), Central Research Institute of Kikkoman Shoya, Noda Chiba, Japan.

Protease TP, its properties and characteristics, as well as methods for its preparation are described in Agr.

Biol. Chem, 28. No. 12, pp. 884-895, December 1964: Studies on the Proteolytic Enzymes of Thermophilic Streptomyces, Part I. Purification and Some Properties; Agr. Biol. Chem, 30, No. 1, pp. 35-41, January 1966: Studies on the Proteoly-tic Enzymes of Thermophilic Streptomyces, Part II. Identification of the Organism and Some Conditions of Protease Formation; and Applied Microbiology, 17, No. 3, March 1969. The authors are Mizusawa et a1.

CRD Protease (also known as Monsanto DA-lO) is a useful powdered enzyme product. CRD-Protease is reported to be obtained by mutation of a Bacillus subtilis organism. lts proteolytic enzyme is about 80% neutral protease and alkaline protease. The neutral protease has a molecular weight of about 44,000 and contains from 1 to 2 atoms of zinc per molecule. It also exhibits amylolytic activity. -Its particle size ranges predominantly from 0.03 mm. to 0.1 mm. and it can be prepared to range in active enzyme content from 20% to 75%. This enzyme can be utilized in the compositions of this invention with excellent results.

Pronase-P, Pronase-E, Pronase-AS and Pronase-AF are powdered enzyme products which can also be used to advantage in this invention. These enzymes are produced from the culture broth of Streptomyces griseus used for streptomycin manufacture. They are isolated by the successive resin column treatment. A major component of the Pronase is a neutral protease named as Srrepromyces griseus protease. This enzyme product is useful herein and provides excellent soiland stain-removing properties.

Another enzyme product preferred for use in the detergent compositions of this invention, as illustrated in the examples below, is a proteolytic enzyme, a serine protease, manufactured by Novo Industri A/S, Copenhagen, Denmark, and sold under the trade name of Alcalase, Al calase is described, in a trade bulletin bearing that name which was published by Novo Industri A/ S, as a proteolytic enzyme preparation manufactured by submerged fermentation of a special strain of Bacillus sublilis. The primary enzyme component of Alcalase is subtilisin. Alcalase is a fine grayish, free-flowing powder having a crystalline active enzyme content of about 6% and a particle size ranging from 1.2 mm. to .01 mm. and smaller, about 75% passing through a 150 mesh Tyler screen. The remainder of the powder is comprised primarily of sodium sulfate, calcium sulfate and various inert organic vehicle materials. Alcalase can be advantageously used with the synthetic de ergent compositions of this invention.

The anionicand ampholytic-containing detergent formulations of the present invention additionally contain a neutral inorganic electrolyte salt. The electrolyte materials of the present invention are optional ingredients in formulations which contain as the detergent a zwitterionic or semi-polar material as hereinbefore described. Because the anionic and ampholytic materials hereinbefore speciried tend to exert a denaturing effect on the proteases of the present invention and thereby adversely affect soiland stain-removing efficacy, a neutral electrolyte salt is included as an essential component in the anionic and ampholytic detergent-containing compositions of the present invention. Suitable neutral electrolyte salts include water-soluble alkali metal (e.g., Na, Li and K) salts, and ammonium salts, e.g., alkali metal and ammonium chlorides; bromides; nitrates; borates; acetates; sulfates and the like. Preferred are sodium chloride and sodium sulfate. It will be appreciated that the above described alkali metal-containing water-soluble salts are described by way of example only and that other non-sequestering salts can be employed to advantage.

The amount of neutral water-soluble electrolyte material employed in the detergent compositions of the present invention is an amount at least suificient to provide in aqueous solution an enzyme-stabilizing effect. From 30% to 50% of the water-solulle neutral electrolyte is employed herein and provides the requisite stabilizing effect The compositions of the present invention can ant preferably do contain an amount of the electrolyte above that required to provide a stabilizing effect in which case the electrolyte serves as either a filler or carrier. In such instances, from 50% to 70% of the electrolyte is employed. The ratio of electrolyte to organic detergent employed in the compositions of the present invention is from 8:1 to 1:2, preferably 4:1 to 1:1.

When the semi-polar nonionic and zwitterionic detergents described hereinbefore are employed herein, the electrolyte is employed to serve as a carrier or filler material in these enzyme-containing detergent compositions of the present invention. When so employed, it is used in an arnount of about 1% to about of the composition.

The detergent compositions of this invention can be prepared in any suitable physical form such as granules (e.g., either spray-dried or mechanically mixed), tablets, pastes, or liquids.

The enzyme-containing detergent compositions of this invention can be formulated by methods known to those skilled in the art. For example, a mixture of organic detergent and inorganic electrolyte utilizable herein can be employed in the form of spray-dried or agglomerated granules or in the form of a mechanical mixture of granular organic detergent and inorganic electrolyte detergent. Detergent granules can range in size from about through a Tyler Standard 6-mesh creen (3.33 mm.) to about 100% on a Tyler ZOO-mesh screen (0.74 mm.). Segregation of granules in the detergent composition is minimized when the particle size of the granules ranges from about 100% through a Tyler Standard 12- mesh screen (1.4 mm.) to about 100% on a Tyler Standard IOO-mesh screen (0.15 mm); this latter particle size range is preferred. The bulk density of the detergent granules, in order to reduce segregation, preferably ranges from about 0.2 gm./cc. to about 0.8 gm./cc.

A mixture of organic detergent and inorganic electrolyte or granules thereof can be mechanically admixed with a proteolytic enzyme described hereinbefore to provide detergent compositions having the advantageous cleaning and soiland stain-removing properties hereinbefore described.

It is normally preferred that the proteolytic enzyme hereinbefore described be incorporated into the detergent compositions of the present invention in a manner which minimizes segregation of the enzyme, preserves proteolytic activity, and enhances the soiland stain-removing properties of the detergent composition. For example, the enzyme can be mixed with water into a slurry and sprayed onto one or more granular components comprising the detergent compositions of this invention and which serve as granular carriers for the enzymatic material. The resulting enzyme-containing granules can be employed as washing compositions per se or can be admixed with any remaining components of the compositions of the invention. Detergent compositions comprising enzymecontaining granules admixed with enzyme-free detergent granules are especially suitable.

In a finished detergent formulation of this invention there will often be added in minor amounts materials which make the product more effective or more attractive. The following are mentioned by way of example. Soluble sodium carboxymethyl cellulose can be added in minor amounts to inhibit soil redeposition. A tarnish inhibitor such as benzotriazole or ethylenethiourea can also be added in amounts up to about 2%. Fluorescers, perfume and color, while not essential in the compositions of the invention, can be added in amounts up to about 1%. Minor amounts of pH adjusters or supplementary buffering agents, such as borates, orthophosphates or carbonates, can be added to adjust and maintain substantially neutral the pH of washing solutions of the finished compositions. There might also be mentioned as suitable additives, water, other enzymes such as amylases, lipases, lipoxidases and other hydrolytic enzymes; brightening agents and bleaching agents such as sodium perborate. In a preferred embodiment of the present invention an amount of from to 50% of the finished composition of a sodium perborate bleach is included. Detergent compositions of the present invention containing such a perborate bleach compound surpass in cleaning effect a standard alkaryl sulfonate built detergent formulation. Such a composition provides a cleaning effect greater than that contributed by either the enzyme component or the perborate alone.

The enzyme-containing detergent compositions of the present invention are especially formulated so as to provide aqueous washing solutions which are substantially neutral as hereinbefore defined. The pH of compositions of the invention is from 6 to 8.5 as conveniently determined, e.g. at a concentration of 0.12%. The behavior and mechanism by which the organic detergent, proteolytic enzyme and inorganic enzyme-stabilizing electrolyte operate to provide unexpectedly high levels of cleaning under substantially neutral pH conditionsv is not completely understood. Unequivoral criteria and principals do not exist which would permit one to predict which components in combination would possess the levels of cleaning exhibited by the compositions of the invention. The sodium salts of linear alkyl benzene sulfonates or tallow alkyl sulfates, for example, are excellent detergent materials believed to be more efficient cleaners than ethoxylated tallow alkyl sulfates. Compositions of the invention embodying an ethoxylated alkyl sulfate, proteolytic enzymes and inorganic electrolytes described hereinbefore provide higher levels of cleaning at pH 7 than corresponding compositions containing the sodium salt of a linear alkyl benzene sulfonate or tallow alkyl sulfate in place of the ethoxylated alkyl sulfate.

The compositions of the present invention can be employed as pre-soak compositions to remove soils and stains prior to a separate laundering step or can be employed as a laundering product according to conventional laundering methods. While the compositions of the invention are especially suited for the laundering of textile materials, they can be employed as cleansing compositions in the washing of dishes, pots and pans, other hard surfaces such as walls and floors and the like.

The following examples serve to illustrate but not limit the novel compositions of the present invention. All amounts in the examples are in parts by weight. The compositions of the following examples provide washing solutions of pH 6 to about 7.5 when dissolved in water.

EXAMPLE I An excellent detergent composition giving outstanding cleaning results in substantially neutral laundering solutions has the following composition in the parts by weight indicated.

Parts Sodium salt of the methyl ester of a-sulfonated tallow fatty acid Sodium sulfate 70 Mixture of about 20 to 80:20 neutral and alkaline subtilisins (Monsanto DA-lO) in inerts 2 Substantially similar results can be obtained when the sodium salt of the methyl ester of u-sulfonated tallow fatty acid is replaced by the sodium, potassium and lithium salts of the methyl, ethyl, propyl, butyl, hexyl and octyl esters of a-sulfonated lauric, myristic, palmitic, stearic, palmitoleic, oleic and linoleic acids; the ammonium, dimethylammonium, tetramethylammonium, dimethyl piperdinium and diethanolamine salts of the methyl, ethyl, propyl,

butyl, hexyl and octyl esters of a-sulfonated lauric, myristic, palmitic, stearic, palmitoleic, oleic and linole c acids.

EXAMPLE II Another excellent detergent composition for use at substantially neutral pH in typical household laundering applications has the following ingredients:

Parts Sodium fi-acetoxy-hexadecane-l-sulfonate 50 Sodium chloride 5O Mixture of 6% Carlsberg subtilisin in inerts (Alcalase) Substantially similar results can be obtained when the following electrolytes are employed in lieu of sodium chloride: sodium bromide; sodium nitrate; sodium sulfate; sodium acetate; and sodium borate.

Substantially similar results can be obtained when the following fl-acyloxy-alkane-l-sulfonates are employed in lieu of sodium fi-acetoxy-hexadecane-l-sulfonate: the sodium salt of ,B-acetoxy-tridecane-l-sulfonic acid; the potassium salt of fl-propionyloxy-tetradecane-l-sulfonic acid; the lithium salt of ,6-butanoyloxy-tetradecane-l-sulfonic acid; the sodium salt of B-pentanoyloxy-pentadecane-1- sulfonic acid; the ammonium salt of fi-hexanoyloxy-hexadecane-l-sulfonic acid; the dimethylammonium salt of 3- heptanoyloxy-tridecane-l-sulfonic acid; the potassium salt of B-octanoyloxy-tetradecane-l-sulfonicacid; the dimethylpiperidinium salt of fi-nonanoyloxytetradecane-l-sulfonic acid; the sodium salt of fl-acetoxy-heptadecane-l-sulfonic acid; the lithium salt of ,B-acetoxy-octadecane-l-sulfonic acid; the dimethylamine salt of fi-acetoxyoctadecanel-sulfonic acid; the potassium salt of fl-acetoxy-nonadecane-l-sulfonic acid; the sodium salt of S-acetoxy-uncosanel-sulfonic acid; the sodium salt of fi-propionyloxydocosane-l-sulfonic acid; and isomers thereof.

EXAMPLE III Excellent cleaning results are obtained in substantially neutral washing solutions using a detergent composition prepared according to this invention and having the following ingredients.

Substantially similar results can be obtained when the following enzymes are employed in lieu of Pronase E: Alcalase, Novo Industri, Copenhagen, Denmark; Maxatase, Koninklijke Nederlandsche Gist-En Spiritusfabriek N.V., Delft, Netherlands; Protease B-4000 and Protease AP, Schweizerische Ferment A.G., Basel, Switzerland; CRD-Protease, Monsanto Company, St. Louis, Mo.; Viokase, VioBin Corporation, Monticello, 111.; Pronase- P, 'Pronase-AS and Pronase-AF all of which are manufactured by Kaken Chemical Company, Japan; Rapidase P-2000, Rapidase, Seclin, France; Takamine, HT proteolytic enzyme 200, Enzyme L-W (derived from fungi rather than bacteria), Miles Chemical Company, Elkhart, Ind.; Rhozyme P-ll concentrate, Rhozyme PF, Rhozyme J-25, Rohm & Hass, Philadelphia, Pa.; Amprozyme 200, Jacques Wolf & Company, a subsidiary of Nopco Chemical Company, Newark, NJ.; Takeda Fungal Alkaline Protease, Takeda Chemical Industries, Ltd., Osaka, Japan; Wallerstein 201-HA, Wallerstein Company, Staten Island, N.Y.; Protin AS-ZO, Dawai Kasei K.K., Osaka, Japan; and Protease TP (derived from thermophilic Streptomyces species strain 1689), Central Research Institute of Kikkoman Shoya, Noda Chiba, Japan.

1 5 EXAMPLE 1v An effective cleaning detergent composition of the present invention when employed in a neutral laundering solution has the following composition:

Parts Sodium salt of sulfonated l-hexadecene 50 Sodium chloride 45 Borax 5 Enzyme mixture of about to 80:20 neutral and alkaline subtilisins in inerts (Monsanto DA-lO) .1

Substantially similar results are obtained when the following olefin sulfonates are employed in lieu of the sodium salt of sulfonated l-hexadecene: the sodium, potassium, lithium and ammonium salts of sulfonated 1- dodecene, l-tetradecene, l-octadecene, l-eicosene, l-docosene and l-tetracosene.

EXAMPLE V An efiective and eificient detergent composition useful in substantially neutral washing solutions according to this invention has the following composition.

Parts Dimethyldodecylphosphine oxide Sodium sulfate 6% Carlsberg subtilisin in inerts (Alcalase) l Substantially similar results can be obtained when the sodium sulfate is completely or partially replaced with dimethyldodecylphosphine oxide.

Substantially similar results are obtained when the following phosphine oxide detergents are substituted for the dimethyldodecylphosphine oxide:

tetradecyldimethylphosphine oxide, tetradecylmethylethylphosphine oxide, 3,6,9-trioxaoctadecyldimethylphosphine oxide, cetyldimethylphosphine oxide, 3-dodecoxy-Z-hydroxypropyldi (Z-hydroxyethyl) phosphine, stearyldimethylphosphine oxide, cetylethylpropylphosphine oxide.

EXAMPLE VI Superior cleaning effects are obtainable in neutral washing solutions with a detergent composition having the following ingredients:

Parts Sodium-3-hexadecylmethylaminopropionate 50 Sodium chloride 46 Sodium carbonate buffer 4 6% Carlsberg subtilisin in inerts (Alcalase) 1 Substantially similar results can be obtained when the following ampholytic detergents are employed in lieu of the sodium hexadecylmethylaminopropionate: sodium 3- dodecylaminopropanesulfonate; sodium 3-dodecylarninopropionate; N-dodecyl-taurines; and N-dodecyl asparate.

EXAMPLE VII A superior detergent composition effective in the cleaning of most textile fabrics under neutral conditions has the following composition:

Parts Dimethylhexadecylammoniopropanesulfonate 50 Sodium chloride 46 Sodium hydroxide pH adjuster 4 6% Carlsberg subtitlisin in inerts (Alcalase 0.1

Substantially similar results can be obtained when the sodium chloride is replaced with sodium bromide; sodium nitrate; potassium chloride; potassium nitrate; sodium orthoborate; sodium acetate; lithium acetate; ammonium chloride and ammonium sulfate.

16 EXAMPLE VIII An effective laundering composition having superior soiland stain-removing properties in neutral washing solution has the following composition;

I Parts Dimethylhexadecylammoniopropanesulfonate 95 Mixture of about 50% :20 neutral and alkaline proteases in inerts (Pronase-E) 0.1

Substantially similar results can be obtained when the dimethylhexadecylammoniopropanesulfonate is replaced with:

4- [N,N-di 2-hydroxyethyl)-N-octadecylammonio] butane-l-carboxylate;

5- [S- 3 -hydroxypropyl -S'hexadecylsulfonio] -3 hydroxy-pentane-l-sulfate;

3- P,P-diethyl-P- 3,6,9-trioxatetracosanephosphono) 2-hydroxypropane-l-phosphate;

3- [N,N-dipropyl-N- 3-dodecoxy-2-hydroxypropyl ammonio) ]-propane-l-phosphonate;

3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxypropane-l-sulfonate;

4- [N,N-di 2-hydroxyethyl -N- Z-hydroxydodecyl ammonio) ]-butane-l-carboxylate;

3-[S-ethyl-S-( 3-dodecoxy-2-hydroxy propylsu1fonio)]- propane-l-phosphate;

3- P,P-dimethyl-P-dodecylphosphonio -propanel phosphonate; and

5- [N,N-di 3-hydroxypropyl -N-hexadecylammonio] -2- hydroxypentane-l-sulfate.

EXAMPLE IX An effective laundering detergent having excellent soiland stain-removing properties in substantially neutral washing solutions has the following composition:

Parts Dimethylhexadecylammoniopropanesulfonate 56 Sodium perborate 44 6% Carlsberg subtilisin in inerts (Alcalase) 0.1

Wash-wear tests using standardized detergent compositions described below were performed to illustrate the relative effectiveness of representative compositions of the present invention. A sodium tripolyphosphate-built anionic active-containing formulation was used as a standard basis of comparison in these tests due to its current wide use in the industry. In addition, compositions corresponding to those of the present invention but containing no enzymes were evaluated. The results of these tests presented in Table I conclusively show the outstanding performance advantages of the detergent compositions prepared according to this invention.

The wash-wear tests involved washing naturally soiled white dress shirts in the following manner. Shirts carrying detachable collars and cuffs were worn by male subjects under ordinary conditions for two normal working days. Following wearing, the collars and cuffs were washed for 10 minutes in a small agitator type machine using solutions of the detergent compositions to be evaluated. These washing solutions were prepared by adding to water of 7 grain hardness the various components of the compositions to be evaluated in the desired amounts. The washing conditions were as hereinafter specified in Table 1. After a washing and drying cycle, the collars and cuffs washed by a composition being evaluated were visually compared with similarly soiled collars and cuffs which were washed in the standard detergent composition under substantially the same conditions. The visual comparison was made by a group of five people who were unfamiliar with the procedure and purpose of the test and formed their judgment independently.

The data from the visual judgments are expressed on a scale such that a value of 0 represents the cleaning ability of water alone and a value of 10 represents the cleaning ability or a very excellent detergent composition used under optimum laboratory conditions along with an effective bleaching agent. On this scale, a value of about 6.5 represents good, better than average, cleaning, while a value of about 3.5 represents unsatisfactory cleaning. The primary purpose of these determinations and this type of grading scheme was to establish the relative cleaning performance of several compositions of this invention as compared to a commercially acceptable type of formula employing a linear alkylbenzenesulfonate detergent and a sodium tripolyphosphate builder. The components and amounts of the materials employed in the washing solutions used in these white shirt detergency tests are indicated in Table 1. In each instance sodium hydroxide was employed to adjust the pH to the stated value. No fluorescers, bleaches or anti-redeposition agents were employed, except where otherwise indicated, so as not to mask the cleaning effect of the compositions of the present invention. The washing solutions in each instance were standardized to the pHs indicated in Table 1 and in all instances the water used contained 7 grains per gallon of hardness. The temperatures of the washing solutions are indicated in Table l. The sodium linear alkyl benzene sulfonate employed as the anionic active in the standardized detergent composition had an alkyl chain distribution averaging about 11.8.

This linear alkylbenzenesulfonate is indicated in Tables 1 and 2 as LAS. The distribution of alkyl chains is as follows: C -8.44; C 33.59; C 36.30; C -16.03; C --5.65.

TABLE 1 [Solution concentrations] 0.03% LAS; 0.06% sodium tripolyphosphate; pH

10, 140 F. (standard) 1 6.5 0.05% sodium fi-acetoxyhexadecane-l-sulfonate; 0.05% NaCl; pH 7; 120 F. (no enzyme) 0.05% sodium B-acetoxyhexadecane-l-sulfonate; 0.05% NaCl; pH 7; 120 F.; 10 p.p.m. Monsanto DA-lO Enzyme 7.0 0.05 3 (N,N dimethyl-N-hexadecylammonio) propane-l-sulfonate; 0.05% NaCl; pH 7; 120 F. (no enzyme) 0.05 3 (N,N dimethyl-N-hexadecylammonio) propane-l-sulfonate; 0.05% NaCl; pH 7; 120 F. p.p.m. Monsanto DA-10 Enzyme 1 6.0 0.05 3 (N,N dimethyl-N-hexadecylammonio) propane-l-sulfonate; 0.04% Na Perborate; pH 8; 120 F., 10 p.p.m. Alcalase 1 8.0 0.05 3 (N,N dimethyl-N-hexadecylammonio) propane-l-sulfonate; pH 7; 120 F.; 10 p.p.m. Monsanto DA-lO Enzyme 1 6.5 0.05% souium hexadecenesulfonate; 0.05% NaCl; pH 7; 120 F.; 10 p.p.m. Monsanto DA-lO Enzyme 1 6.5 0.05 sodium tallow hexaoxyethylene sulfate; pH

7; 120 F.; 0.05% NaCl; 10 p.p.m. Monsanto DA-l Enzyme 1 7.5 0.05% sodium a-sulfotallow methyl carboxylate;

0.05% NaCl; pH 7; 120 F.; p.p.m. Monsanto DA-IO Enzyme 1 6.0

1 Equals or excels the standard.

For purposes of comparison with detergent compositions of the present invention the above described washwear test was repeated employing a sodium linear alkylbenzenesulfonate as the detergent in combination with an electrolyte and enzyme component of the present invention. In addition, sodium betaacetamindohexadecane-1- sulfonate and a conventional nonionic detergent, the condensation product of 6 moles of ethylene oxide and 1 mole of coconut fatty alcohol were evaluated for purposes of comparison with the compositions of the present invention. The results of these tests are described in Table 2.

1 8 TABLE 2 Comparative Tests [Solution concentrations] 0.05 LAS; 0.05 NaCl; 10 p.p.m. Monsanto DA-10 Enzyme; pH 7; F. 3.5 0.05% sodium fl-acetamidohexadecane-l-sulfonate; 0.05 NaCl; 10 p.p.m. Monsanto DA-lU Enzyme; pH 7; 120 F. 45 0.05% condensate of 6 moles of ethylene oxide and 1 mole coconut fatty alcohol; 0.05 70 NaCl; 10 p.p.m. Monsanto DA-IO Enzyme; pH 7, 120 F. 4.5

The results of Table 1 illustrate the superior cleaning properties of compositions of the present invention and illustrate the elficacy of each of these compositions as compared with a standard alkaline built formulation commonly employed in the detergency industry and with compositions corresponding to those of the invention, but containing no enzymes. The results indicated in Table 2 illustrate the cleaning effects of compositions containing certain anionic and nonionic surfactants and enzymes. These compositions fail to equal in cleaning performance the hereinbefore described standard composition or those of the present invention.

Having described the invention in detail, what is claimed is:

1. A substantially neutral laundry detergent composition consisting essential of:

(A) from 10% to 70% of a synthetic organic detergent selected from the group consisting of:

(1) compounds of the formula wherein R is alkyl or alkenyl of from 10 to 20 carbon atoms, R is alkyl of 1 to 10 carbon atoms and M is a salt-forming radical;

(2) compound of the formula II ()CR; Rr-CH-CHzSOa wherein R is alkyl of from 9 to 23 carbon atoms, R is alkyl of 1 to 8 carbon atoms and M is a salt-forming radical;

(3) compounds of the formula wherein R is alkyl or alkenyl of from 10 to 20 carbon atoms, at is 1 to 30 and M is a salt-forming radical;

(4) olefin sulfonates having from 12 to 24 carbon atoms;

(5) compounds of the formula wherein R is alkyl of from 8 to 18 carbon atoms, R is alkyl of l to 3 carbon atoms or is hydrogen, R is alkylene of 1 to 4 carbon atoms, Z is carboxy, sulfonate, sulfate, phosphate or phosphonate and M is a salt-forming radical; (B) from 0.001% to 10% of a proteolytic enzyme derived from a bacterial or fungal source and characterized by proteolytic activity in aqueous solution at temperatures of from about 50 F. to about F. in the pH range of from 6 to 8.5; and (C) from 30% to 70% of a proteolytic enzyme-stabilizing water soluble, neutral non-sequestering electrolyte salt selected from the group consisting of alkali metal and ammonium chloride, bromides, nitrates, borates, acetates and sulfates,

19 said substantially neutral laundry composition having a pH of from 6 to 8.5 in aqueous solution.

2. The composition of claim 1 wherein proteolytic enzyme is a bacterial protease.

3. The composition of claim 2 wherein the proteolytic enzyme consists essentially of a Bacillus subrilis-derived subtilisin and inert powdered materials.

4. 'lhe composition of claim 3 wherein the synthetic organic detergent is a compound of the formula wherein R is alkyl of 10 to 20 carbon atoms; R is alkyl of 1 to 10 carbon atoms and M is an alkali metal.

5. The composition of claim 4 wherein the ratio of proteolytic enzyme-stabilizing water soluble, neutral nonsequestering electrolyte salt to synthetic organic detergent is from 8:1 to 1:2.

6. The composition of claim 4 wherein the proteolytic enzyme-stabilizing, water soluble, neutral, non-sequestering electrolyte salt is an alkali metal salt.

7. The composition of claim 6 wherein the proteolytic enzyme-stabilizing, water soluble, neutral, non-sequestering electrolyte salt is sodium chloride.

8. The composition of claim 7 wherein the synthetic organic detergent is a compound having the formula wherein R is alkyl or alkenyl of from 10 to 20 carbon atoms; x is from 1 to 30; and M is an alkali metal; and the proteolytic enzyme-stabilizing, water soluble, neutral, nonsequestering electrolyte salt is an alkali metal salt.

9. The composition of claim 7 wherein the synthetic organic detergent is an alkali metal salt of a sulfonated l-olefin having from 12 to 24 carbon atoms; and the proteolytic enzyme-stabilizing, water soluble, neutral, nonsequestering electrolyte salt is an alkali metal salt.

10. The composition of claim 7 wherein the synthetic organic detergent is a compound of the formula rn-bn-crnsom wherein R is alkyl of 9 to 23 carbon atoms; R is alkyl of 1 to 8 carbon atoms; M is alkali metal; and the proteolytic enzyme-stabilizing, water soluble, neutral, nonsequestering, electrolyte salt is an alkali metal salt.

11. The composition of claim 10 wherein the synthetic organic detergent is a compound of the formula OPJR,

wherein R is alkyl of 12 to 16 carbon atoms, R is methyl; M is an alkali metal; and the proteolytic enzyme-stabilizing, water soluble, neutral, non-sequestering electrolyte salt is sodium chloride.

20 12. A substantially neutral laundry detergent composition consisting essentially of:

(A) from 10% to 99% of a synthetic organic detergent selected from the group consisting of (1) compounds of the formula wherein R is alkyl, alkenyl or monohydroxyalkyl of from 8 to 18 carbon atoms, having from 0 to 10 ethylene oxide moieties and from O to l glyceryl moiety and R and R are each alkyl or monohydroxyalkyl groups of 1 to 3 carbon atoms; (2) compounds of the formula 32): R.-i cH,R1z

wherein R is alkyl, alkenyl or hydroxyalkyl of from 8 to 18 carbon atoms, having from 0 to 10 ethylene oxide moieties and 0 to 1 glyceryl moiety; Y is nitrogen, phosphorus or sulfur; R is alkyl or monohydroxyalkyl of 1 to 3 carbon atoms; x is 1 when Y is sulfur and 2 when Y is nitrogen or phosphorus; R is alkylene or hydroxyalkylene of l to 4 carbon atoms; and Z is carboxylate, sulfonate, sulfate, phosphonate or phosphate; and

(B) from 0.001% to 10% of a proteolytic enzyme derived from a bacterial or fungal source and characterized by proteolytic activity in aqueous solution at temperatures from about 50 F. to about F. in the pH range of from 6 to 8.5; said substantially neutral laundry composition having a pH of from 6 to 8.5 in aqueous solution.

13. The composition of claim 12 wherein the proteolytic enzyme is a bacterial protease.

14. The composition of claim 13 wherein the proteolytic enzyme consists essentially of a Bacillus subtiIis-derived subtilisin and inert powdered materials.

15. The composition of claim 14 wherein the synthetic organic detergent is a compound of the formula R|Y -CH RsZ wherein R is alkyl, alkenyl or hydroxylakyl of 8 to 18 carbon atoms; R is alkyl or monohydroxyalkyl of 1 to 3 carbon atoms; at is 2; Y is nitrogen; R is alkylene or hydroxyalkylene of 1 to 4 carbon atoms; and Z is a sulfonate group.

16. The composition of claim 15 wherein R is hexadecyl; R is methyl; and R is propylene.

17. The composition of claim 16 containing an alkali metal perborate bleaching compound.

References Cited UNITED STATES PATENTS 2,152,520 3/1939 Lind 252-99X 3,451,935 6/1969 Roald et al. 282-89 3,472,783 10/ 1969 Smillie 25289 MAYER WEINBLA'I'I, Primary Examiner US. Cl. X.R.

26289, 95,135,137, Dig l2 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,600,318 Dated August 17, 1971 Inventor(s) ROY C. Mast It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 11, line 36, delete after Alcalase and insert 1 therefor Column 16, line 17, delete "trioxatetracosanephosphono and insert therefor trioxatetracosanephosphonio Column 19, Claim 6, line 22, delete "4" and insert therefor Column 19, Claim 8, line 28, delete 7" and insert therefor Column 19, Claim 9, line 37 delete "7" and insert therefor Column 19, Claim 10, line 42, delete 7" and insert therefor 3 Column 19, Claim ll, line 61, delete "[CH from the formula.

Signed and sealed this 7th day of March 1972.

(SEAL) Abtest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Ahhosting Officer Commissioner of Patents