US3714050A

US3714050A - Stain removal

Info

Publication number: US3714050A
Application number: US00829104A
Authority: US
Inventors: F Gray
Original assignee: Colgate Palmolive Co
Current assignee: Colgate Palmolive Co
Priority date: 1968-03-07
Filing date: 1969-05-29
Publication date: 1973-01-30
Anticipated expiration: 1990-01-30
Also published as: NL6903616A; DE1908905A1; GB1226493A; US3840466A; US3637339A; FR2003378A1; CA943891A; NL7309966A; CH506617A; BE729544A; NL7309965A

Abstract

A stain-removing dry composition containing sodium perborate, a proteolytic enzyme and MgSO4. The presence of the MgSO4 gives superior stability on aging.

Description

ilnited States Patent 1 Gray [ 51 Jan. 30, 1973 [54] STAIN REMOVAL [75] Inventor: Frederick William Gray, Summit,

[73] Assignee: Colgate-Palmolive. Company, New

York,N.Y.

[22] Filed: May 29, 1969 [21] Appl. No.: 829,104

Related U.S. Application Data [63] Continuation-impart of Ser. Nos. 711,203, March 7, 1968, abandoned, and Ser. No. 726,571, May 3, 1968, abandoned.

[52] U.S. Cl. ..252/99, 8/111, 252/95, 252/96, 252/97, 252/98, 252/186 [51] Int. Cl. .l ..Clld 7/56 [58] Field of Search ..252/99, 98, 97, 96, 95, 186; 8/111 [5 6] References Cited UNlTED STATES PATENTS 2,152,520 3/1939 Lind ..252/99 Reichert et a1. ..252/186 FORElGN PATENTS OR APPLICATIONS Primary Examiner-Mayer Weinblatt Attorney-Herbert S. Sylvester, Murray M. Grill, Norman Blumenkopf, Ronald S. Cornell, Thomas- J. Corum, Richard N. Miller and Robert L. Stone [57] ABSTRACT A stain-removing dry composition containingvsodium perborate, a proteolytic enzyme and MgSO The presence of the MgSO, gives superior stability on aging.

18 Claims, No Drawings 9/1957 Belgium ..252/99 STAIN REMOVAL This application is a continuation-in-part of my applications Ser. Nos. 711,203 filed Mar. 7, 1968 and 726,571 filed May 3, 1968 now abandoned.

One aspect of this invention relates to compositions containing sodium perborate and an enzyme which are useful for removal of stains from soiled fabrics.

It has now been found that outstanding stability can be attained in such formulations by including magnesium sulfate therein. It has also been found that these magnesium sulfate-containing formulations tolerate the presence of perborate activators and large amounts of other salts, such as sodium sulfate and sodium tripolyphosphate, and still show outstanding stability. Particularly useful compositions contain a surface active agent, such as a synthetic anionic detergent.

The invention is particularly useful in compositions made with sodium perborate tetrahydrate, which has the empirical formula NaBO 414 and which has a crystalline form of good mechanical strength, unlike.

the relatively fragil sodium perborate monohydrate.

1n the preferred form the composition contains an activator for the perporate.

The perborate activators are a well known class of materials, dexcribed for example in a series of articles by Gilbert in Detergent Age, June 1967 pages 18 20; July 1967 pages 33; and August 1967 pages 26, 27 and 67. The perborate activators of greatest importance in the practice of this invention are compounds which are percarboxylic acid precursors, forming such percarboxylic acids on reaction with the perborate. As explained by Gilbert, such compounds include esters and anhydrides and acyl amides. Examples of suitable activators are given by Gilbert who also describes a test for suitability. Among the activators which may be used are the following:

N-acetyl phthalimide N-acetyl succinimide trisacetyl cyanurate N-benzoyl succinimide Phenyl acetate Acetylsalicylic Acid N-p-anisoyl succinimide N-alpha-napthoyl succinimide N-beta-nathoyl succinimide N-benzoyl glutarimide N-p-chlorobenzoyl succinimide N-benzoyl succinimide N-p-chlorobenzoyl-5,S-dimethyl hydantoin N -o-chlorobenzoyl succinimide N-p-chlorobenzoyl phthalimide Benzoic anhydride Phthalic anhydride Further examples of suitable activator compounds of the imide type, both cyclic and aliphatic, have the following structural formula:

0 Bra-OR wherein R represent alkyl and preferably lower alkyl of one to four carbon atoms or aryl such as phenyl and R, represents an N-bonded imide radical. Thus, included within the foregoing structural formula are the follow- N-methoxycarbonyl saccharide N-methoxycarbonyl phthalimide N-ethoxycarbonyl phthalimide v N-methoxycarbonyl-5,5-dimethyl hydantoin N-methoxycarbonyl succinimide N-phenoxycarbonyl succinimide N,N-di-(methoxycarbonyl) acetamide N-methoxycarbonyl glutarimide l ,3 -di-(N-methoxycarbonyl)-hydantoin l,3-di-(N-methoxycarbonyl)-5 ,S-dimethyl hydantoin Other suitable activator compounds are represented according to the following structural formula:

wherein X represents halogen, e.g., chloro and Z represents the atoms necessary to complete a hetero? cyclic nucleus selected from the group consisting of hydantoin and succinimide.

Specific representatives of compounds of this type include, without necessary limitation, the following:

N-m-chlorobenzoyl-S ,S-dimethyl hydantoin N-m-chlorobenzoylsuccinimide. etc. Another group of activator compounds comprises N-sulfonated cyclic imides including those of the following structural formula:

wherein R represents lower alkyl of from one to four carbon atoms and aryl and Z represents the atoms necessary-to complete a heterocyclic ring selected from the group consisting of succinimide and phthalimide. Specific examples of compounds of this type include, without necessary limitation, the following:

N-benzenesulfonyl phthalimide N-benzenesulfonyl succinimide N-methanesulfonyl phthalimide N-methanesulfonyl succinimide 1 I A further class of activator compounds comprises alkyl and aryl chloroformate derivatives, including for example: r

methylchloroformate ethylchloroformate phenylchloroformate Another class of activators comprises benzoylimidazoles which may, for convenience, be represented according to the following structural formula:

It will be further understood that the aforedepicted N-benzoylimidazole molecule may further contain one or more substituent groups the salient requirement being that any such group be devoid of any tendency to deleteriously affect or otherwise impair, for example, the activator capabilities of such compounds. Thus, inert and inoccuous groups such as typified by alkyl, halo, loweralkoxy, amino e.g., monoand di-loweralkylamino such as dimethylamino, diethylamino, etc., nitro and the like may be present as substituents upon either of the benzoyl or imidazole moieties. Thus, specific examples of N-benzoylimidazole compounds falling within the foregoing formula definition and found to provide pronounced advantage in the relationships contemplated by the subject invention include, without necessary limitation:

N-benzoylimidazole N-(o,m and p-nitro)-benzoylimidazole N-(o,m and p-methyl)benzoylimidazole N-(o,m and p-chloro)-benzoylimidazole N-(o,m and p-bromo)-benzylimidazole N-(o,m and p-trifluoromethyl)-benzoylimidazole N-(o,m and p-dimethylamino)-benzoylimidazole N-(o,m and p-diethylamino)-benzoylimidazole N-(o,m and p-di-n-butylamino)-benzoylimidazole N-(o,m and p-methoxy)-benzoylimidazole N-(o,m and p-ethoxy)-benzoylimidazole N-(o,m and p-n-butoxy)-benzoylimidazole .etc

N-m-fluorobenzoylimidazole Thus, the language N-benzoylimidazole is to be accorded a meaning and significance in the context of the present invention consistent with the foregoing definition. The benzoylimidazole compounds contemplated for use herein may be readily and conveniently prepared according to procedures well known in the art as by reacting imidazole with benzyol chloride or substituted benzoyl chloride.

The proportions of per-compound, activator, and enzyme will be influenced by the physical and chemical properties of these ingredients, the time and temperature of the bleaching or laundering operation, and the degree of bleaching desired.

The stable compositions of this invention have relatively low moisture contents. Best results have been obtained with compositions in which the total moisture content (including water of hydration, except that bound to the sodium perborate tetrahydrate) is such that the amount of water bound to the MgSO is well below its amount in M gSO; 7H O. For example, in certain very good compositions the total moisture content is less than about percent (e.g., about 2 to 3 percent) of the total weight of the composition, and is also less than about 70 percent (e.g., about 30 50 percent) of the weight of MgSO and less than about 50 percent (e.g., about 20 30 percent) of the weight of the sodium perborate tetrahydrate.

The amount of magnesium sulfate may be varied. For instance, the presence of as little as percent of anhydrous MgSO, based on the weight of sodium perborate tetrahydrate has produced a definite increase in stability, while a proportion of over 50 percent, e.g., about 60 70 percent (based, again, on the weight of the sodium perborate tetrahydrate) has given especially good results. It is also within the scope of the invention to use an excess of MgSO e.g., an amount of MgSO, which is, say, two or three times the amount of sodium perborate tetrahydrate.

In the preferred form of the invention the enzyme comprises a proteolytic enzyme which is active upon protein matter and catalyzes digestion or degradation of such matter when present as in linen or fabric stain in a hydrolysis reaction. The enzymes may be effective at a pH range of say about 4 12, and may be effective even at moderately high temperatures so long as the temperature does not degrade them. Some proteolytic enzymes are effective at up to about C. and higher. They are also effective at ambient temperature and lower to about 10 C. Particular examples of proteolytic enzymes which may be used in the instant invention include pepsin, trypsin, chymotrypsin, papain, bromelin, colleginase, keratinase, carboxylase, amino peptidase, elastase, subtilisia and aspergillopepidase A and B. Preferred enzymes are subtilisin enzymes manufactured and cultivated from special strains of spore forming bacteria, particularly bacillus subtilis.

Proteolytic enzymes such as Alcalase, Maxatase, Protease AP, Protease ATP 40, Protease ATP 120, Protease L-252 and Protease L-423 are among those enzymes derived from strains of spore foaming bacillus, such as bacillus subtillis.

Different proteolytic enzymes have different degrees of effectiveness in aiding in the removal of stains from textiles and linen. Particularly preferred as stain removing enzymes are subtilisin enzymes.

Metalloproteases which contain divalent ions such as calcium, magnesium or zinc bound to their protein chains are of interest.

The enzyme preparations are generally extremely fine, often substantially impalable, powders. In a typical powdered enzyme preparation the particle diameter is mainly below 0.15 mm, generally above 0.01 mm, e.g., about 0.1 mm; for example, as much as 75 percent of the material may pass through a mesh (U.S. Standard) sieve.

The enzyme preparations are generally extremel diluted with salts such as calcium sulfate and inert materials. The preferred enzymes are typically stable in the pH range of 5 to 10, e.g., at an alkaline pH of 8.5 to 9, and in solution they can withstand temperatures of 49 C to 77 C with relatively little decomposition for time periods varying from 2 hours at the higher temperatures to more than 1 day at the lower temperatures. Different proteolytic enzymes have different degrees of effectiveness in aiding in the removal of stains from textiles and linen.

Instead of, or in addition to, the proteolytic enzyme, an amylase may be present such as a bacterial amylase of the alpha type (e.g., obtained by fermentation of B. subtilis). One very suitable enzyme mixture contains both a bacterial amylase of the alpha type and an alkaline protease, preferably in proportions to supply about 100,000 to 400,000 Novo alpha-amylase units per Anson unit of said alkaline protease.

The enzyme concentration can be varied widely. Typically the enzyme preparation is present in amount in the range of about 0.00l percent 4 percent by weight of the total detergent formulation, preferably in the range of about 0.05 1 percent and most preferably in the range of about 0.1 to 0.5 percent. The optimum proportion of enzyme preparation to be used in a detergent composition containing per-compound and activator will of course depend upon the effective enzyme content of the enzyme preparation. As with per-compound content, the quantity of enzyme preparation to be used for stains susceptible to enzyme action will be dependent upon a number of factors, particularly time, temperature, and proportions of per-compound and activator. For the enzyme preparation sold as Alcalase (having an activity of about 1.5 Anson units per gram) a preferred range of proportions is one which gives about 1 to 100 ppm, more preferably about 2 to 30 ppm, of the Alcalase in the soaking water or wash water. This 2 to 30 ppm concentration corresponds to about 0.003 0.045 Anson units per liter of wash water or, in a formulation designed for use at a concentration of 1 gram per liter of soaking water, about 0.003 0.045 Anson units per gram of detergent formulation.

The preferred compositions of this invention contain water-soluble builder salts.

Examples of such builder salts include phosphates and particularly condensed phosphates (e.g., pyrophosphates or tripolyphosphates), silicates, borates and carbonates (including bicarbonates), as well as organic builders such as salts of nitrilotriacetic acid or ethylene diamine tetraacetic acid. Sodium and potassium salts are preferred. Specific examples are sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, sodium carbonate, sodium bicarbonate, sodium sesquicarbonate, sodium tetraborate, sodium silicate, salts (e.g., Na salt) of methylene diphosphonic acid, disodium diglycollate, trisodium nitrilotriacetate, or mixtures of such builders, including mixtures of pentasodium tripolyphosphate and trisodium nitrilotriacetate in a ratio, of these two builders, of 1:10 to :1, e.g., 1:1.

In addition to the builder salt the product will generally contain an organic detergent. A typical presoak product contains a relatively high concentration of builder salt such as about 30, 40 or 50 to 95 percent pentasodium tripolyphosphate(calculated as anhydrous pentasodium tripolyphosphate), about 2 to 10 percent of organic surface active detergent, plus other ingredients such as sodium silicate (which acts as a builder salt and also acts to inhibit corrosion of aluminum surfaces), brightening agents and sodium sulfate. A laundry detergent generally has a lower ratio of builder salt to organic surface active agent (e.g., a ratio in the range of about 1:1 to 8:1 but other proportions such as :1 may be used).

The surface active agent preferably comprises a synthetic anionic detergent, such as an alkylbenzene sulfonate or other sulfonate detergent.

The anionic surface active agents include those surface active or detergent compounds which contain an organic hydrophobic group and an anionic solubilizing group. Typical examples of anionic solubilizing groups are sulfonate, sulfate, carboxylate, phosphonate and phosphate. Examples of anionic detergents which may be used include the soaps, such as the watersoluble salts of higher fatty acids or resin acids, such as may be derived from fats, oils and waxes of animal, vegetable origin, e.g., the sodium soaps of tallow, grease, coconut oil, tall oil and mixtures thereof; and the sulfated and sulfonated synthetic detergents, particularly those having about 8 to 26, and preferably about 12 to 22, carbon atoms to the molecule.

having a high content of 3- (or higher) phenyl isomers and a correspondingly low content (well below 50 percent) of 2- (or lower) phenyl isomers; in other terminology, the benzene ring is preferably attached in large part at the 3 or higher (e.g., 4, 5, 6 or 7) position of the alkyl group and the content of isomers in which the benzene ring is attached at the 2 or 1 position is correspondingly low. Particularly preferred materials are set forth in U. 5. Pat. No. 3,320,174, May 16,1967, of J. Rubinfeld.

Other anionic detergents are the olefin sulfonates, including long chain alkene sulfonates, long chain hydroxyalkane sulfonates or mixtures: of alkenesulfonates and hydroxylalkane sulfonates. These olefin sulfonate detergents may be prepared, 7 in known manner, by the reaction of S0 with long chain olefins (of 8 25, preferably 12 21, carbon atoms) of the formula RCH-CHR where R is alkyl and R is alkyl or hydrogen, to produce a mixture of sultones and alkenesulfonic acids, which mixture is then treated'to convert the sultones to sulfonates. Examples of other sulfate or sulfonate detergents are paraffin sulfonates having, for example, about 10 20, preferably about 15 20, carbon atoms such as the primary paraffin sulfonates made by reacting long chain alpha olefins and bisulfrtes (e.g., sodium bisulfite) or paraffin sulfonates having the sulfonate groups distributed along the paraffin chain such as the products made by reacting a long chain paraffin with sulfur dioxide and oxygen under ultraviolet light followed by neutralization with NaOH or other suitable base (as in U. S. Pat. Nos. 2,503,280; 2,507,088; 3,260,741; 3,372,188 and German Patent 735,096); sulfates of higher alcohols; salts of a-sulfofatty esters (e.g., of about 10 to 20 carbon atoms, such as methyl a-sulfomyristate or a-sulfotallowate).

Examples of sulfates of higher alcohols are sodium lauryl sulfate, sodium tallow alcohol sulfate, Turkey Red Oil or other sulfated oils, or sulfates of monoor di-glycerides of fatty acids (e.g., stearic monoglyceride monosulfate), alkyl poly (ethenoxy) other sulfates such as the sulfates of the condensation products of ethylene oxide and lauryl alcohol (usually having. one to five ethenoxy groups per molecule); lauryl or other higher alkyl glyceryl ether sulfonates; aromatic poly (ethenoxy) other sulfates such as the sulfates of the condensation products of ethylene oxide and nonyl phenol (usually having one to six oxyethylene groups per molecule).

The anionic detergents include also the acyl sarcosinates (e.g., sodium lauroylsarcosinate) the acyl esters e.g., oleic acid ester) of isethionates, and the acyl N-methyl taurides (e.g., potassium N-methyl lauroylor oleyl tauride).

The most highly preferred water soluble anionic detergent compounds are the ammonium and substituted ammonium (such as mono-, diand triethanolamine), alkali metal (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium) salts of the higher alkyl benzene sulfonates, olefin sulfonates, the higher alkyl sulfates, and the higher fatty acid monoglyceride sulfates. The particular salt will be suitably selected depending upon the particular formulation and the proportions therein.

Nonionic surface active agents include those surface active or detergent compounds which contain an organic hydrophobic group and a hydrophilic group which is a reaction product of a solubilizing group such as carboxylate, hydroxyl, amido or amino with ethylene oxide or with the polyhydration product thereof, polyethylene glycol.

As examples of nonionic surface active agents which may be used there may be noted the condensation products of alkyl phenols with ethylene oxide, e.g., the reaction product of isooctyl phenol with about six to 30 ethylene oxide units; condensation products of alkyl thiophenols with 10 to ethylene oxide units; condensation products of higher fatty alcohols such as tridecyl alcohol with ethylene oxide; ethylene oxide addends of monoesters of hexahydric alcohols and inner ethers thereof such as sorbitan monolaurate, sorbitol monooleate and mannitan monopalmitate, and the condensation products of polypropylene glycol with ethylene oxide.

Examples of suitable amphoteric detergents are those containing both an anionic and a cationic solubilizing group and a hydrophobic organic group, which is advantageously a higher aliphatic radical containing 10 carbon atoms. Among these are the N-long chain alkyl aminocarboxylic acids (e.g., of the formula the N-long chain alkyl iminodicarboxylic acids (e.g., of the formula RN(R'COOM) and the N-long chain alkyl betaines (e.g., of the formula where R is a long chain alkyl group of about 10 20 carbons, R is a divalent radical joining the amino and carboxyl portions of an amino acid (e.g., an alkylene radical of one to four carbon atoms), M is hydrogen or a salt-forming metal, R is a hydrogen or another monovalent substituent (e.g., methyl or other lower alkyl), and R, and R are monovalent substituents joined to the nitrogen by carbon-to-nitrogen bonds (e.g., methyl or other lower alkyl substituents). Examples of specific amphoteric detergents are N-alkyl-betaaminopropionic acid; N-alkyl-beta-iminodipropionic acid, and N-alkyl, N,N-dimethyl glycine; the alkyl group may be, for example, that derived from coco fatty alcohol, lauryl alcohol, myristyl alcohol (or a lauryl-myristyl mixture), hydrogenated tallow alcohol,

cetyl, stearyl, or blends of such alcohols. The substituted aminoproppionic and iminodipropionic acids are often supplied in the sodium, potassium, alkylolammonium, or other salt forms, which may likewise be used in the practice of this invention. Examples of other amphoteric detergents are the fatty imidazolines such as those made by reacting a long chain fatty acid (e.g., of 10 to 20 carbon atoms) with diethylene triamine and monohalocarboxylic acids having two to six carbon atoms, e.g., l-coco-5-hydroxyethyl-5-carboxymethylimidazoline; betaines containing a sulfonic group instead of the carboxylic group; betaines in which the long chain substituent is joined to the carboxylic group without an intervening nitrogen atom, e.g., inner salts of Z-trimethylamino fatty acids such as 2-trimethyl-aminolauric acid, and compounds of any of the previously mentioned types but in which the nitrogen atom is replaced by phosphorous.

Various other materials may be present in the granular products. Thus, materials such as the higher fatty acid amides may be added 'to improve detergency and modify the foaming properties in a desirable manner. Examples thereof are the higher fatty acid alkanolamides, preferably having two to three carbons in each alkanol group and a fatty acyl radical within the range of 10 l8 carbons, preferably 10 l4 carbons, such as lauric or myristic monoethanolamides, diethanolamides and isopropanolamides. Tertiary higher alkyl amino oxides such as having about 10 l8 carbons in one alkyl group, e.g., lauryl or myristyl dimethylamine oxide, may be added also. Fatty alcohols of 10 18 carbons such as lauryl or coconut fatty alcohols, or cetyl alcohols are suitable additives also. A hydrotropic material such as the lower alkyl aryl sulfonates, e.g., sodium toluene or xylene sulfonates, can assist processing also. In general, these materials are added in minor amounts, usually from about to 10 percent, preferably 1 to 6 percent, based on the total solids.

The composition may also contain polymeric additives such as sodium carboxymethylcellulose or polyvinyl alcohol (e.g., in amount of about 0.1 5 percent) or other polymeric additives to inhibit redeposition of soil. Minor amounts or optical brighteners may be present, as in proportions in the range of about 0.01 to 0.15 percent; examples of such brighteners are the stilbene brighteners such as sodium-2-sulfo-4-(2-naphtho-l, 2 triazole) stilbene; disodium 4,4'-bis (4-anilino-6- morpholino-s-triazin-Z-yl amino) stilbene disulfonate or disodium 4,4'-bis (4,6-dianilino-s-triazin-2-ylamino) stilbenedisulfonate; and the oxazole brighteners, having for example a l-phenyl-2-benzoxazole ethylene structure. Perfumes, coloring agents and preservatives may also be included.

A preferred range of proportions of the perborate is one which provides a concentration of per compound in the soaking water equivalent to about 5 to 200 ppm more preferably about 10 to l00 ppm, e.g., 10 to 50 ppm, of available oxygen. in sodium perborate tetrahydrate (NaBO 4l-l,0) the available oxygen content (or peroxy oxygen content) is about 10 percent; i.e., one atom of available oxygen per molecule of the perborate. The proportions of perborate for use in the formulation can therefore readily be calculated if one knows how much of the total formulation is to be added to the water. Commercial formulations are often designed for use in proportions in the range of about 0.05 1 percent in the soaking water (e.g., at 0.1 or 0.5 percent concentration), a preferred formulation containing sodium perborate tetrahydrate designed for use at the 0.1 percent concentration in the wash water will therefore contain approximately to 50 percent of that compound, correspondingly roughly to the 10 to 50 ppm of available oxygen.

Since individual activators vary in structure and molecular weight as well as performance, it is convenient to relate the quantity of activator to be employed to the desired available oxygen present in the particular per-compound being used. For reactive aromatic mono-acyl compounds such as metachlorobenzoyldimethylhydantoin, meta-chlorobenzoylsuccinimide and benzoylimidazole strong bleaching is obtained when approximately equimolecular quantities of activator and peroxygen are present. Bleaching is enhanced with increase in the concentration of activator and maintenance of about a 1:1 mol ratio of activator and the peroxygen present in the per-compound. By increase of the mol ratio of available oxygen to activator, milder bleaching is obtained particularly when the ratio is greater than 2:1 e.g., 3:1 or higher. For reactive aliphatic poly-acylated compounds such as tetraacetylethylenediamine, tetra-acetylmethylenediamine, tetra-acetylhydrazine, triacetyl cyanurate, the mole ratio of available oxygen to activator is preferably 2:] although higher (e.g., 6:1 or 10:1) or lower (e.g., about 1:1 or less) mol ratios may be employed. The presence of the MgSO appears to not only enhance the stability of the composition but has also, according to preliminary tests, been observed to promote the bleaching action, making it possible to use less activator in relation to the amount of perborate to attain a given level of stain removal.

in a particularly preferred form of the invention an aqueous mixture of builder salt, detergent and magnesium sulfate is converted to dry granular form, as by spray drying, to form hollow beads and clusters of such beads, and then mixed with the sodium perborate tetrahydrate, activator and enzyme. When large amounts of a hydratable builder salt such as pentasodium tripolyphosphate are present and the aqueous mixture is to be spray dried, it is preferred to maintain the aqueous mixture (which may have a total water content in the range, for example, of about 30 to 60 percent) in heated condition, e.g., at a temperature above 60 C, and more preferably above about 70 C or 80 C, to reduce the tendency for hydration and consequent undesirable thickening of the mixture prior to spraying. It is also desirable to have sodium sulfate present (e.g., in proportion of at least about 3 percent); this salt. has been found to have a thinning effect (e.g., a viscosityreducing effect) on the mixture making it possible to avoid aeration during mixing, and to spray relatively concentrated mixtures readily to form products of desirable higher, but not very high, apparent density. It will be understood that part of the magnesium sulfate introduced into the aqueous mixture may be converted to other salts as by exchange of ions, during the mixing and spraying procedure.

By the practice of this invention there are provided novel compositions which are highly effective for cleaning clothes, including the removal of stains therefrom by presoaking (prior to washing in an automatic washing machine), by washing in automatic machines or by hand.

The following Examples are given to illustrate this invention further. In the Examples, as in the rest of the application, all-proportions are by weight unless otherwise indicated. 1

EXAMPLE 1 This Example illustrates the effect of a commercial proteolytic enzyme powder on the stability of sodium perborate, and the desirable effect of the presence of magnesium sulfate on the mixture.

One part of commercial sodium perborate (NaBO 4H O) is mixed with 0.08 part of the proteolytic enzyme preparation known as Alcalase and 0.6 part of anhydrous magnesium sulfate. The mixture (of powders) is placed in sealed glass vials which are aged for various times at 49 C and then analyzed for their loss of active oxygen that is, for loss of bleaching activity of the perborate. The active oxygen content is measured in conventional manner by acidifying the mixture (as with dilute aqueous H and titrating it with standard aqueous sodium thiosulfate solution. For comparison an identical mixture of sodium perborate and the en-' zyme preparation without the magnesium sulfate is similarly tested. After 6 days the mixture containing no magnesium sulfate has lost 59 percent of its active oxygen content, while the mixture containing the magnesium sulfate has lost none of its active oxygen content. After 11 days at 49 C. the corresponding figures are 63 percent vs. only 2 percent.

EXAMPLE 2 This Example illustrates the fact that the stabilizing effect of the magnesium sulfate is also exhibited in built detergent compositions containing the perborate and enzyme, as well as an activator for the perborate.

The results are tabulated below:

Proportions,

in parts by weight Composition A B Built Detergent Blend 1" 81.8 81.8 Perborate 10.0 10.0 Alcalase 0.8 0.8 Activator 7.4 7.4 MgSO, 6.3 None Average oxygen loss after aging in sealed vial at 49C for: 3 days 2% 23% 37 days 7% 57% When the amount of MgSO, is reduced (e.g., to 1,2 or 4 parts by weight, instead of 6.3 parts by weight) it is found that the presence of the MgSO still exerts a significant, though reduced, stabilizing effect, although the results with 6.3 parts are substantially better than those with 4 parts.

In this Example Built Detergent Blend I contains 60 parts of anhydrous pentasodium tripolyphosphate, 0.5 part of carboxymethylcellulose and 5 parts of trisodium nitrilotriacetate monohydrate together with a spray dried granular product containing 6 parts of sodium dodecylbenzenesulfonate, 0.75 part of sodium silicate (Na ozSiO ratio 1:2.35 3 parts of sodium sulfate and 0.12 part of water. The Perborate" is NaBOy 4H O, and the Activator" is N,N,N,N'-tetraacetylethylenediamine which is a known perborate activator.

When in the formulation given in this Example 2 the 6.3 parts of MgSO, is replaced by an equal weight of any one of the following anhydrous salts, the average oxygen loss on aging at 49 C is found to be much greater than when the MgSO, is used: potassium carbonate, sodium acetate, sodium sulfate, additional pentasodium tripolyphosphate, potassium sulfate, calcium sulfate, barium sulfate, sodium metasilicate, magnesium silicate. For instance, with the magnesium silicate the oxygen loss is 76 percent after 18 days in the sealed vial at 49 C.

" EXAMPLE 3 The following Example illustrates the effect of the addition of MgSO, to a crutcher mix of conventional type (containing pentasodium tripolyphosphate and organic detergent) before spray-drying, after which the spray dried material is dry-blended with the perborate, activator and enzyme. e

In a crutcher (of conventional type having a high speed agitator) the following ingredients are mixed in the order in which they are listed: water; 7.96 parts of sodium linear tridecylbenzenesulfonate; 1 part of sodium silicate (Na O:SiO ratio 12.35); parts of anhydrous Na SO 74.68 parts of anhydrous pentasodium tripolyphosphate (TPP); and 8.36 parts of anhydrous MgSO,. The water content of the mixture is about 40 percent. A temperature of about 190 F. (88 'C.) is maintained during and after the addition of the tripolyphosphate to inhibit hydration of the latter and resulting thickening of the crutcher mix. The mixture is then spray-dried into a current of hot air, to form granules which are in the form of hollow beads or clusters of such beads and which have a total water content of 3 percent. This total water content includes water of hydration and may be determined by conventional methods, such as by using an Ohaus moisture determination balance at atmospheric pressure using temperatures sufficient to break down any hydrates that may be present, as well known to those skilled in the art. The apparent density of the spray dried granules is about 0.44 g/cc. (that is, 237 cc of the granules, loosely packed in a cup, weigh 105 grams).

600 parts of the spray dried mixture are then dryblended with 14.7 parts of commercial brightener 4,4- bis (4-anilino-6 morpholine-s-triazin-Z-yl amino)- 2, 2- stil-benedisulfonic acid, disodium salt and 3.8 parts of commercial brightener 2-styrlnaphth (l,2)- oxazole and 7.3 parts of perfume. This pre-mix is then dryblended with another 3,384 parts of the spray dried mixture, 490 parts of NaBO 4H O, 362.5 parts of the activator, tetraacetylethylenediamine, and 39.2 parts of the enzyme, Alcalase. The resulting mixture, which has an apparent density of 0.57 g/cc is placed into sealed cardboard cartons having outer wax moisture proof coatings. The cartons are given two tests. In one they are aged for 7 weeks at room temperature; at the conclusion of this test the contents of the cartons are found to be free-flowing and to be unchanged with respect to active oxygen content and enzyme content. In another test the cartons are aged for 25 days in an oven at 49 C; at the conclusion of this aging period the contents are observed to show no caking and the active oxygen content is about 98 percent of its original value.

When the product is used in a concentration of 0.l percent in tap water having a hardness of 100 ppm for the overnight soaking of clothes, including a mixture of cotton, nylon, cotton-dacron goods which are colored as well as white and some of which have attached thereto elastic material such as rubber or spandex it shows very good cleaning and stain removal ability with little, if any, color damage, or color transfer and little, if any, of the staining that often occurs in the soaking of nylon and cotton fabrics in the presence of fabrics which contain elastic materials. In addition to being good for the removal of ink and many common fruit and beverage stains, this activated perborate enzyme detergent composition is especially beneficial in the cleaning of everyday laundry items, such as pillow cases and under-garments which have been in contact with soil from hair and skin of the body. This latter benefit is particularly manifested when a solution of the composition is utilized as a pre-soak bath prior to a normal machine wash of the clothes with a regular commercial detergent product.

In another soak test, 1 gram of the composition is added to a beaker containing 1 liter of water at 49 C. Three coffee/tea and three standard cocoa stained swatches are introduced in each instance. The test swatches are allowed to soak without agitation for a period of 18 hours, the bath normally coming to room temperature (25 C.) in this period of time. The test swatches are then rinsed, dried, and reflectance readings on the fabrics before and after soaking are obtained, using a Gardner Color Difference Meter, to determine the change in reflectance (A Rd). The A Rd values obtained by the use of the freshly prepared composition of Example 3 and by composition of Example 3 which has been aged at 49 C. in a sealed vial for a period of 48 days are given below.

A Rd Coffee/T ea Cocoa Fresh Product of Example 3 8.2 10.5 Aged Product of Example 3 7.1 10.1

Cocoa is a proteinaceous substance and cocoa-stained fabric is a commonly used material for testing the effectiveness of detergents for removing protein stains.

It is also found that in place of the anhydrous MgSO, employed in this Example, MgSO 7H O may be added to the crutcher in amount to provide the same proportion of M gSO with similar results.

EXAMPLE 4 Example 3 is repeated except that the crutcher mix contains the brighteners, the sodium silicate is added to the water just before the addition of the brighteners (which are added just before the alkylbenzenesulfonate) and the proportions of TPP, MgSO, and Na SO in the crutcher mix are changed to 74.33 parts, 7.49 parts, and 5.94 parts, respectively, and the spraydried material (which has an apparent density of about 0.44 g/cm) is blended with the perborate, activator, and enzyme powder in the proportions of 81.65 parts of the spray-dried material (of 3 percent H O content), 10 parts of sodium perborate tetrahydrate, 7.44 parts of the activator and 0.76 parts of the enzyme powder. The

EXAMPLE Spray dried detergent material corresponding to that given in Example 4 except that magnesium sulfate is omitted from the crutcher mix is prepared. It is blended with sodium perborate tetrahydrate, enzyme and activator in the proportions of 81.8 parts sprayed detergent material (without magnesium sulfate), parts perborate, 7.1 parts tetra-acetylmethylenediamine and 0.8 part of the Alcalase. On aging at 49 C. in sealed container, essentially complete loss in active oxygen takes place within 3 weeks. By incorporating anhydrous magnesium sulfate into the composition, reasonably good stability can be obtained. Thus when 10 parts of finely divided anhydrous magnesium sulfate are added to this composition, it loses less than 30 percent of its original active oxygen content when aged at 49 C. for 3 weeks.

Detergent compositions containing perborate, tetraacetylmethylenediamine, enzyme and magnesium sulfate should be stored in a moisture proof carton preferably in a dry cool place, the temperature preferably not exceeding 40 C. Products formulated with these ingredients are particularly suitable for soaking clothes prior to machine washing. Soil and stain removal is achieved without damage or dye transfer occurring to fabric being laundered.

EXAMPLE 6 A detergent formula having the following composition is prepared:

ingredients Composition (grams) A B Detergent Blend 11 0.818 0.818 Sodium Perborate Tetrahydrate 0.100 0.100 Alcalase 0.008 0.008 Benzoylimidazole 0.058 None In this Example, Detergent Blend 11 is a granular product containing 3 percent total water and made by spray drying an aqueous slurry containing about 80 parts of anhydrous sodium tripolyphosphate, 8 parts of sodium linear dodecylbenzenesulfonate, 8.5 parts of anhydrous magnesium sulfate and 1 part of sodium silicate (Na- O:SiO ratio is 122.35 The benzoylimidazole activator which is a liquid is present in a mole ratio of perborate to activator of 2:1 and it is adsorbed onto the detergent blend.

Compositions A and B are each added to a tergotometer receptacle containing one liter of water at 120 F. Three coffee-tea and three cocoa stained swatches (3 X 6 inches) are used as the wash samples in each instance. After a 10 minute agitated wash at 120 F the test swatches are rinsed and dried. Instrumental readings are obtained with a Gardner Color Difference Meter, the Rd values for each test swatch being obtained before and after the bleach treatment. The

results for the three swatches are averaged and the cal- A Rd Cocoa 12.0

Coffee-Tea Composition A 6.2

Composition B 1.8

These results indicate. that significant bleaching of non proteinaceous soil (as represented by results with coffee-tea stain) can be achieved with the activated perborate system while not adversely affecting the ability of the enzyme to remove the proteinaceous stain, cocoa.

EXAMPLE 7 A spray-dried granular composition is made by adding to a crutcher as in Example 3z'water, then 8.21 parts of sodium linear tridecylbenzenesulfonate, then 5 parts of anhydrous sodium sulfate, then 1.03 parts of sodium silicate (Na,0:sio, 1:2.35) then, after raising the temperature to 71 C., 77.14 parts of anhydrous TPP, and then 8.62 parts of anhydrous MgSO The mixture, containing 45 percent water, is then placed in a tank at 88 C. and thereafter passed into a vacuum chamber maintained at 77 C. to reduce the water content to 40 percent by evaporation, and finally sprayed into a spray tower supplied with hot'air at a temperature of 275 290 C. at such a rate that the total moisture content of the resulting granules (hollow beads and clumps of such heads) is 2.3 percent. The granules are free-flowing and have an apparent density of about 0.5 g/cc.

818 parts of the granules are mixed with 8 parts 0 the Alcalase enzyme powder, 100 parts of sodium perborate tetrahydrate and (a) 174 parts or (b) 58 parts of finely divided m-chloro-benzoyldimethylhydantoin to give thereby compositions having perborate to activator ratios of (a) 1:1 and (b) 3:1 respectively.

The compositions of Examples 3 to 5 are particularly suitable for use in the removal of stains by pre-soaking fabrics (e.g., cotton clothing) prior to machine-washing.

The Alcalase used in the foregoing Examples is a proteolytic enzyme preparation having its maximum proteolytic activity at a pH of 8 10 (e.g., 9). This activity as measured at pH 7.5 on the commercial enzyme preparation available from Novo lndustri A/S, Copenhagen, Denmark, is about 1.5 Anson Units per gram of the enzyme. The commercial enzyme prepara tion is a raw extract of bacillus subtilis culture and contains about 6 percent of pure crystallized proteolytic material. The preparation is an extremely fine powder;

typically the particle diameter is mainly below 0.15 mm, generally above 0.01 mm, e.g., about 0.1 mm, and as much as 50 percent or even percent of material may pass through a mesh sieve (U.S. Standard). Another very suitable enzyme preparation is Maxatase which has an activity of 330,000 Delft units per gram, which in this case is about the same as that of the Alcalase (Delft units are measured on the basis of casein digestion, Anson units on the basis of hemoglobin digestion). These enzyme preparations contain major proportions of diluent salts such assodium chloride, sodium sulfate and calcium sulfate.

Spray dried granules of built detergent composition, including those used in a preferred form of this invention are often in major part at least about 0.2 mm in diameter, e.g., about 0.3 or 0.4, or even 0.5, l or 2 mm in diameter. 7

It is within the broader scope of the invention to use the magnesium sulfate in admixture with the sodium perborate, particularly the tetrahydrate, in the absence of any or all of the other components, such as the enzyme, surface active agent, activator, builder slat, etc. For example, compositions as in Example 7 but omitting the enzyme are suitable for use, for instance, under normal automatic washer conditions especially when oxidizable stains are present in the laundry load. The composition containing an equimolecular ratio of perborate and activator is a stronger bleach than the one with a 3:1 ratio, the latter being recommended when the wash load contains dyed fabrics or when an extended wash period is to be employed.

It will be apparent that variations of the inventions may be made and equivalents substituted therefor.

Iclaim:

l. A substantially dry composition for use, in water, for the removal of stains from fabrics, said compositions being a mixture of sodium perborate tetrahydrate present in amount sufficient to increase the bleaching effectiveness of the composition, proteolytic enzymes present in amount sufficient to improve the effectiveness of the composition for removal of protein stains, and magnesium sulfate, present in amount sufficient to improve the stability of the composition.

2. A composition as in claim 1 containing sodium perborate tetrahydrate and a proteolytic enzyme and having a total water content such that the amount of water bound to the MgSO is less than 7 mols per mol of M gSO 3. A composition as in claim 2 in which the total moisture content is less than about 70 percent of the weight of MgSO,, said composition containing an activator for the perborate, said activator being a percarboxylic acid precursor and being present in a proportion such that the mol ratio of available oxygen to activator is in the range of about 1:1 to 10:1.

4. A composition as in claim 3 in which the composition contains pentasodium tripolyphosphate in amount of at least about 30 percent, the total water content of said composition being less than about 5 percent.

5. A composition as in claim 1 which is a blend of (a) granules made by spray drying an aqueous slurry of sodium tripolyphosphate, sodium sulfate, magnesium sulfate and water-soluble synthetic organic anionic, nonionic or amphoteric detergent, (b) finely divided sodium perborate tetrahydrate and (c) proteolytic enzyme.

6. A composition as in claim 15, said granules containing alkylbenzenesulfonate detergent and said composition including a perborate activator which has a carboxylic acyl group and which, on said use of the composition in water, reacts with said sodium perborate to form the corresponding percarboxylic acid, and which is present in amount sufficient to activate the perborate.

7. A composition as in claim 6 in which the ratio of chlorobenzoyl irnide perborate activator.

11. A composition as in claim 2 containing the perborate activator, m-chlorobenzoyl dimethylhydantoin.

12. A substantially dry finely divided composition for use, in water, for the removal of stains from fabrics, said composition consisting essentially of sodium perborate tetrahydrate and magnesium sulfate, and having a total water content such that the amount of water bound to the MgSO is less than 7 mols per mol of Mg- SO said magnesium sulfate being present in amount sufficient to improve the stability of said composition on aging at elevated temperature in a moistureproof container, said composition being one which in the absence of said magnesium sulfate shows a loss of active oxygen on said aging.

13. A composition as in claim 12 in which the total moisture content is less than about percent of the weight of MgSO.,, said composition containing an activator for the perborate, said activator being one which has a carboxylic acyl group and which, on said use of the composition in water, reacts with said sodium perborate to form the corresponding percarboxylic acid and being present in a proportion such that the mol ratio of available oxygen to activator is in the range ofaboutlzltolOzl.

14. A composition as in claim 13 in which the composition contains pentasodium tripolyphosphate in amount of at least about 30 percent, the total water content of said composition being less than about 5 percent.

15. A composition as in claim 12, packaged in a sealed moistureproof container.

16. A composition as in claim 13, packaged in a sealed moistureproof container.

17. A composition as in claim 14, packages in a sealed moistureproof container.

18. A composition as in claim 1 in which the magnesium sulfate and the sodium perborate are present as separate particles.

Claims

1. A substantially dry composition for use, in water, for the removal of stains from fabrics, said compositions being a mixture of sodium perborate tetrahydrate present in amount sufficient to increase the bleaching effectiveness of the composition, proteolytic enzymes present in amount sufficient to improve the effectiveness of the composition for removal of protein stains, and magnesium sulfate, present in amount sufficient to improve the stability of the composition.

2. A composition as in claim 1 containing sodium perborate tetrahydrate and a proteolytic enzyme and having a total water content such that the amount of water bound to the MgSO4 is less than 7 mols per mol of MgSO4.

3. A composition as in claim 2 in which the total moisture content is less than about 70 percent of the weight of MgSO4, said composition containing an activator for the perborate, said activator being a percarboxylic acid precursor and being present in a proportion such that the mol ratio of available oxygen to activator is in the range of about 1:1 to 10:1.

7. A composition as in claim 6 in which the ratio of sodium tripolyphosphate to detergent is in the range of about 1:1 to 15: 1 the amount of perborate activator being such that the mol ratio of available oxygen to activator is in the range of about 1:1 to 10:1.

8. A composition as in claim 2 containing the perborate activator, tetra-acetylethylenediamine.

9. A composition as in claim 2 containing a benzoylimidazole perborate activator.

10. A composition as in claim 2 containing an m-chlorobenzoyl imide perborate activator.

12. A substantially dry finely divided composition for use, in water, for the removal of stains from fabrics, said composition consisting essentially of sodium perborate tetrahydrate and magnesium sulfate, and having a total water content such that the amount of water bound to the MgSO4 is less than 7 mols per mol of MgSO4, said magnesium sulfate being present in amount sufficient to improve the stability of said composition on aging at elevated temperature in a moistureproof container, said composition being one which in the absence of said magnesium sulfate shows a loss of active oxygen on said aging.

13. A composition as in claim 12 in which the total moisture content is less than about 70 percent of the weight of MgSO4, said composition containing an activator for the perborate, said activator being one which has a carboxylic acyl group and which, on said use of the composition in water, reacts with said sodium perborate to form the corresponding percarboxylic acid and being present in a proportion such that the mol ratio of available oxygen to activator is in the range of about 1:1 to 10:1.

15. A composition as in claim 12, packaged in a sealed moistureproof container.

16. A composition as in claim 13, packaged in a sealed moistureproof container.

17. A composition as in claim 14, packages in a sealed moistureproof container.