US3553139A - Enzyme containing detergent composition and a process for conglutination of enzymes and detergent composition - Google Patents

Abstract

DETERGENT COMPOSITIONS CONTAINING AN ENZYME A PERCOMPOUND AND A MIXTURE OF BUILDER SALTS AND ORGANIC DETERGENTS. THE COMPOSITION IS MILDER THAN WOULD BE EXPECTED.

Description

R 3553139 EX ENZYME CONTAINING DETERGENT COMPOSI- TlON AND A PROCESS FOR CONGLUTINATION OF ENZYMES AND DETERGENT COMPOSITION Charles Bruce McCarty, Cincinnati, Ohio, assignor to The Procter 8; Gamble Company, Cincinnati, Ohio, a corporation of Ohio No Drawing. Application Apr. 12, 1967, Ser. No. 635,293, which is a continuation-in-part of applications Ser. No. 544,846, Apr. 25, 1966, and Ser. No. 620,608, Mar. 6, 1967. Divided and this application Feb. 24, 1969, Ser. No. 801,773

Int. Cl. Clld 7/54 U.S. Cl. 252-95 6 Claims ABSTRACT OF THE DISCLOSURE Detergent compositions containing an enzyme a percompound and a mixture of builder salts and organic detergents. The composition is milder than would be expected.

CROSS REFERENCE This application is a division of copending application Ser. No. 635,293 of Apr. 12, 1967 which is a continuationin-part of application Ser. No. 544,846 of Apr. 25, 1966 and Ser. No. 620,608 of Mar. 6, 1967 which were copending with Ser. No. 635,293 and are now abandoned.

PRIOR ART Enzymes have been used as cleaning aids for many years. As early as 1915, Rhom had found that fabrics could be cleaned more easily and at lower temperatures when pretreated with fat and protein digesting enzymes. See Rhom, German Pat. 283,923 (May 15, 1915). Later, in 1932, enzymes were utilized in a soap composition having greatly improved cleansing action. See Frelinghuysen, U.S. Pat. 1,882,279 (Oct. 11, 1932). Enzymes aid in laundering by attacking soil and stains found on soiled fabrics. Soils and stains are decomposed or altered in such an attack so as to render them more removable during laundering.

Enzymes can be used either in a soaking or pre-wash product designed to prepare soiled fabric for more effective detergency when the fabrics are subjected to conventional laundering, or as a component of a detergent formulation containing conventional cleaning ingredients. The enzymes suitable for such laundry uses are usually found in a fine powder form. Enzymes are expensive and powerful materials which must be judiciously formulated and used. Such fine powders of concentrated materials are difficult to handle, difficult to measure and difiicult to formulate.

OBJECT Accordingly, an object of this invention is to provide a mild enzyme containing detergent composition.

This invention concerns detergent compositions having improved mildness characteristics. These detergent compositions contain a combination of a peroxy compound such as sodium perborate and an enzyme. Such mild compositions can comprise only a peroxy compound such as sodium perborate and an enzyme; however, in the usual application, other detergent ingredients are added to this combination, e.g., organic detergent compounds and builder salts.

The addition of enzymes or per compounds such as sodium perboate to detergent compositions generally decreases the mildness of that detergent composition. Surprisingly, and quite unexpectedly, it has been found that when combinations of peroxy compounds such as sodium perborate and enzymes described herein are added to a detergent composition, there is little or no noticeable change in the mildness characteristics of the detergent compositions. These rather harsh detergent ingredients apparently coact in some manner to produce a mild detergent composition having the beneficial cleaning properties of both the enzyme and the peroxy compound.

Enzymes which contain sulfhydryl groups or disulfide bonds, e.g. pepsin, trypsin, papain, lipase, diastase and urease, may be inactivated by high concentrations of the per compounds described herein. Proteases having optimum activity in the alkaline range which do not contain sulfhydryl groups or disulfide bonds are not inactivated to any great extent by these per compounds and are therefore highly desirable for use in this mild detergent composition. The proteases having optimum activity in the alkaline range which do not contain sulhydryl groups or disulfide bonds are exemplified by the subtilisin family of enzymes, for example, BPN', Novo Bacterial Proteinase, Alcalase and the alkaline protease portion of CRD protease.

The active enzyme content of the mild detergent composition should, preferably, be from about 0.005% to about 4.0% by weight of the detergent composition, and most preferably, from about 0.006% to about 0.12%.

The peroxy compounds utilized in this aspect of this invention comprise, preferably, from about 5% to about 30% of the mild detergent composition, most preferably, from about 8% to about 25%. Other peroxy compounds can be used instead of the preferred sodium perborate, e.g., sodium percabonate and sodium persulfate. Other cations can be utilized in place of sodium, e.g., potassium, am-

monium and lithium,

The remainder of the mild detergent composition can be comprised of active detergent compounds and builder salts. The compositions of the invention comprise from about to of a mixture of builder salts and organic detergents in a ratio of builder salts to organic detergents of from about 1:4 to about 30:1. A suitable ratio of builder salts to organic detergents is from about 0.4:1 to about 15:1.

These mild detergent compositions can be made by mechanically mixing, by the process described herein or by the process described in the copending application, Ser. No. 635,293 filed by McCarty or Ser. No. 630,199 filed by Roald et al. on Apr. 12, 1967 and now U.S. Pat. 3,451,- 935 issued June 24, 1969, or by any of the detergent preparation methods known in the art.

The compositions of this invention can also contain minor amounts of other materials to make them more attractive or more effective. The following are mentioned by way of example. A soluble sodium carboxymethylcellulose may be added in minor amounts, e.g., 0% to about 5%, to inhibit soil redeposition. Tarnish inhibitors such as benzotriazole or ethylenethiourea or phosphonate corrosion inhibitors may also be added in amounts up to about 2%. Brighteners, fluorescers, bactericides, perfume and color may be added in amounts up to about 3%.

To avoid caking and/or segregation in the detergent composition, the granules can have particle size distributions and densities which are approximately the same. The particle size distributions can be such that about of the g anules pass througha Tyler Standard 6 mesh screen and about 100% of the granules are retained on a Tyler Standard 200 mesh screen (i.e., ranging from about .075 mm. to about 3.3 mm. in particle size). Preferably, the particle size distribution can range from about 100% of the granules through a Tyler standard 12 mesh screen to about 100% of the granules retained on a Tyler Standard 103 mesh screen (i.e., ranging in particle size from 0.14 mm. to 1.4 mm.). Another particularly useful size distribution is not more than about 30% of the granules retained on a Tyler Standard 14 mesh screen and no more than about 7% of the granules through a Tyler Standard 100 mesh screen. The density of the granules making up the detergent composition can range from about 0.2 gm./ cc. to about 0.8 gm./cc.

The products of this invention are effective in all cleaning applications in both hard and soft water. They are especially effective in removing soil and foreign materials from textiles and fabrics. For example, these products effectively remove or aid in removing the most commonly found soil on garments: skin flakes or other keratin, and lipid mixtures of triglycerides, wax esters, hydrocarbons, free fatty acids, sterols and lipoproteins, e.g., blood, pus, paint, grease, oil and grass stains. Additionally, by utilizing an enzyme which has some amylolytic activity, the detergent compositions of this invention are particularly efficacious for dishwashing and cleaning pots and pans.

In addition to performing cleaning and whitening functions, the products of this invention facilitate measuring specific amounts of enzyme into a soaking or washing solution. This is advantageous since enzymes are effective in small amounts and are expensive when compared with ordinary detergents. By attaching the enzymes to base granules which serve as a diluent, the concentration of enzymes is decreased. Thus, the housewife can measure suitable amounts of product by effective amounts of enzymes into soaking or washing solutions.

ENZYMES The enzymes of this invention are solid catalytically 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.

Enzymes suitable for use in this invention are those active in a pH range of from about 4 to about 12 and, preferably, are active in the pH range of from about 7 to about 11 and at a temperature in the range of from about 50 F. to about 185 F. preferably from 70 F. to 170 F.

White, Handler, Smith, Stetten, Principles of Biochemistry, (First Edition 1954) is a valuable reference on enzymes.

The proteases catalyze the hydrolysis of the peptide linkage of proteins, polypeptides and related compounds to free amino and carboxyl groups and thus breakdown the protein structure in soil. Specific examples of proteases are pepsin, trypsin, chymotrypsin, collagenase, keratinase, elastase, subtilisin, BPN, a papain, bromelin, carboxy peptidase A and B, amino peptidase, aspergillopeptidase A and aspergillopeptidase B. The highly preferred proteases are serine proteases which are active in the neutral to alkaline pH range and are produced from microorganisms such as bacteria, fungi or mold.

The enzymes described herein are utilized in this invention in a dry, powdered form. It is desirable that the enzymes be used in a dry form as degradation of the enzymes is minimized. The powdered form of enzymes is most easily handled and is, therefore, preferred.

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 vehicles such as starch, organic clays, sodium or calcium sulfate or sodium chloride, during enzyme manufacture. Enzymes are grown in solution. Such vehicles are added after filtration of such solution to precipitate the enzyme in fine form which is then dried; calcium salt also stabilize enzymes. The combination of enzyme and inert vehicle usually comprises from about 2% to about active enzyme. The enzyme powders of this invention, including the examples, mostly are fine enough to pass through a Tyler Standard 20 mesh screen (0.85 mm.) although larger agglomerates are often found. Some par ticles of commercially available enzyme powders are fine enough to pass through a Tyler Standard mesh screen. Generally a major amount of particles will remain on a 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 enzye powders of the examples have particle size distributions in these ranges.

The commercial powdered enzyme products are useful and are generally dry powdered products comprised of about 2% to about 80% active enzymes in combination with an inert powdered vehicle such as sodium or calcium sulfate or sodium chloride as the remaining 98-20%. Active enzyme content of a commercial product is a result of manufacturing methods employed and is not critical herein so long as the finished granules have the desired enzymatic activity. Many of these commercial products contain the preferred proteases as the active enzyme. In most cases, a subtilisin comprises the major portion of the proteases. Some of these commercial products contain. in addition to the proteases, lipases, carbohydrases. esterases and nucleases. Other commercial products contain only lipases, carbohydrases, esterases and nucleases.

Specific examples of commercial enzyme products include: Alcalase; Maxatase; Protease B-4000 and Protease AP; CRD-Protease; Viokase; Pronase-P, Pronase-AS and Pronase-AF; Rapidase P-2000; Takamine; Bromelain 1:10; HT proteolytic enzyme 200; Enzyme L-W (derived from fungi rather than bacteria); Rhozyme P-ll concentrate; Pectinol; Lipase B; Rhozyme PF; Rhozyme J-25, Rhozyme PF and J-25 have salt and corn starch vehicles and are proteases having diastase activity; Amprozyme 200.

CRD Protease (also known as Monsanto DAl0) is a useful powdered enzyme product. CRD-Protease is reported to be obtained by mutation of a Bacillus subtilis organism. It is about 80% neutral protease and 20% alkaline protease. The neutral protease has a molecular weight of about 44,000 and contains from 1 to 2 atoms of zinc per molecule. Its particle size ranges predominantly from 0.03 mm. to 0.1 mm. The CRD-Protease can be used in an aqueous system having a pH ranging from about 5.4 to about 8.9. It can be prepared to range in active enzyme content from 20% to 75%. The presence of CaCl in the enzyme powder increases the pH range over which this enzyme can be utilized. This enzyme can be utilized in the composition of this invention with excellent results in washing solutions at temperatures ranging from about 50 F. to about 150 F. and at lower pHs suitable for prewash soaking or higher pHs for detergency purposes.

Pronase-P, 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 Srreptomyces griseus used for streptomycin manufacture. They are isolated by the successive resin column treatment. The major component of the pronase is a neutral protease named as Streptomyces griseus protease, This enzyme product contains a calcium stabilizer salt and is fairly stable over a wide pH range, e.g., 4 to 10, and is fairly stable over a temperature range of 50 F. to 150 F.

Another enzyme product preferred for use in the detergent compositions of this invention, including a number of the examples, is a proteolytic enzyme, a serine protease, sold under the trade name of Alcalase. Alcalase 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 Subtilis. The primary enzyme component of Alcalase is subtilisin. In addition to proteolytic activity, Alcalase exhibits other forms of desirable enzymatic activity. Alcalase is a fine grayish, freefiowing 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 has unusually stable properties in solution. For example, Alcalase can withstand a pH of about 9 at relatively high temperatures, i.e., 150-170 F., for a short time. At 120 F., the activity of Alcalase is virtually unchanged in a 24- hour period when held at this pH. Alcalase can be advantageously used with soap and synthetic detergent compositions of this invention. Sequestrants such as EDTA can improve the stability of Alcalase.

Organic detergents The organic detergent compounds which can be utilized in detergent compositions of this invention are the following:

(a) Water-soluble soap: Examples of suitable soaps for use in this invention are the sodium, potassium, ammonium and alkanolammonium (e.g., mono-, di-, and triethanolammonium) salts of higher fatty acids Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium and potassium tallow and coconut soaps.

(b) Anionic synthetic non-soap detergents. A preferred class can be broadly described as the water-soluble salts, particulatly the alkali metal salts, of organic, sulfuric acid reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals. (Included in the term alkyl is the alkyl portion of higher acyl radicals.) Important examples of the synthetic detergents which form a part of the preferred compositions of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C -C carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in which the alkyl group can be a straight or branched chain and contains from about 9 to about carbon atoms; sodium alkyl glyceryl ether sulfonates, especially those ethers of the higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium or potassium salts of sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and about 1 to 6 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with about 1 to about 10 units of ethylene oxide per molecule and in which the alkyl radicals contain from about 8 to about 12 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amide of a methyl tauride in which the fatty acids, for example, are derived from coconut oil; sodium and potassium salts of sulfonated C C a-olefins.

(c) Nonionic synthetic detergents. One class can be utilized in the detergent granules as detergent actives in addition to their specific function of rendering the detergent granules glutinous. The nonionics can be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic ele* ments. Another class has semi-polar characteristics.

(1) A class of nonionic synthetic detergents under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility, has a molecular weight of from about 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the product is retained up to the point where the polyoxyethylene content is about 50% of the total weight of the condensation product.

(2) The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration with ethylene oxide, the said ethylene oxide being present in amounts equal to 5 to 25 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octene, or nonene, for example.

(3) Those nonionic synthetic detergents derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine. For example, compounds containing from about 40% to about polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 to 3,000 are satisfactory.

(4) The condensation product of aliphatic alcohols having from 8 to 22 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g., a coconut alcohol-ethylene oxide condensate having from 5 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms.

(5) The ammonia, monoethanol and diethanol amides of fatty acids having an acyl moiety of from about 8 to about 18 carbon atoms. These acyl moieties are normally derived from naturally occurring glycerides, e.g., coconut oil, palm oil, soybean oil and tallow, but can be derived synthetically, e.g., by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer- Tropsch process.

(6) Long chain tertiary amine oxides corresponding to the following general formula n -tonot-z's-so wherein R is an alkyl radical of from about 8 to about 24 carbon atoms, R and R are each methyl, ethyl or hydroxyethyl radicals, R is ethylene, and n equals from 0 to about 10. The arrow in the formula is a conventional representation of a semi-polar bond. Specific examples of amine oxide detergents include dimethyldodecylamine oxide and bis-(2-hydroxyethyl)dodecylamine oxide.

(7) Long chain tertiary phosphine oxides corresponding to the following general formula R-R'R"P O wherein R is an alkyl, alkenyl or monohydroxyalkyl radical ranging from 10 to 24 carbon atoms in chain length and R and R" 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 found in US. Pat. 3,304,263 which issued Feb. 14, 1967, and include: dimethyldodecylphosphine oxide and dimethyl- (2-hydroxydodecyl) phosphine oxide.

7 (8) Long chain sulfoxides having the formula T RSR wherein R is an alkyl radical containing from about to about 28 carbon atoms, from O to about 5 ether linkages and from 0 to about 2 hydroxyl substituents, at least one moiety of R being an alkyl radical containing 0 ether linkages and containing from about 10 to about 18 carbon atoms, and wherein R is an alkyl radical containing from 1 to 3 carbon atoms and from one to two hydroxyl groups. Specific examples of these sulfoxides are: dodecyl methyl sulfoxide and 3-hydroxy tridecyl methyl sulfoxide.

(d) Ampholytic synthetic detergents can be broadly described as derivatives of aliphatic secondary and tertiary amines, in which the aliphatic radical may be straight chain or branched and wherein one of the allphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfo, sulfato, phosphato, or phosphono. Examples of compounds falling within this definition are sodium-3-d0decylaminopropionate and sodium-3-dodecylaminopropane sulfonate.

(e) Zwitterionic synthetic detergents can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium and sulfonium compounds, in which the aliphatic radical may be straight chain or branched, and wherein one of the aliphatic substituents contains from about 8 to 24 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfo, sulfato, phosphato or phosphono. Examples of compounds falling within this definition are 3-(N,N dimethyl-N-hexadecylammonio) propane-l-sulfonate and 3-(N,N-dimethyl-N-hexadecylammonio) 2 hydroxy propane-l-sulfonate which are preferred for their cool water detergency characteristics. See, for example, Snoddy et al., Canadian Pat. 708,148.

These soap and non-soap anionic, nonionic, ampholytic and zwitterionic detergent compounds can be used singly or in combination. The above examples are merely illustrations of the numerous suitable detergents. Other organic detergent compounds can also be used.

Builder salts The detergent composition of this invention contains water-soluble, builder salts either of the organic or inorganic types.

Examples of suitable water-soluble, inorganic alkaline detergency builder salts are alkali metal carbonates, borates, phosphates, polyphosphates, bicarbonates, silicates and sulfates. Specific examples of such salts are sodium and potassium tetraborates, perborates, bicarbonates, carbonates, tripolyphosphates, pyrophosphates, orthophosphates and hexametaphosphates. Sodium sulfate, although not classed as an alkaline builder salt, is included in this category.

Examples of suitable organic alkaline detergency builder salts are: (1) Water-soluble aminopolycarboxylates, e.g., sodium and potassium ethylenediaminetetraacetates, nitrilotriacetates and N-(Z-hydroxyethyl)-nitrilo diacetates; (2) Water-soluble salts of phytic acid, e.g., sodium and potassium phytates-see U.S. Pat. 2,739,942; (3) Watersoluble, polyphosphonates, including specifically, sodium, potassium and lithium salts of ethane-l-hydroxy-1,1-diphosphonic acid, sodium, potassium and lithium salts of methylene diphosphonic acid, sodium, potassium and lithium salts of ethylene diphosphonic acid, and sodium, potassium and lithium salts of ethane-l,1,2-triphosphonic acid. Other examples include the alkali metal salts of ethane-E-carboxy-l,l-diphosphonic acid, hydroxymethanediphosphonic acid, carbonyldiphosphonic acid, ethane-1- hydroxy-1,l,Z-triphosphonic acid, ethane-2-hydroxy-1,l,2- triphosphonic acid, propane-1,l,3,3-tetraphosphonic acid, propane-l,1,2,3-tetraphosphonic acid, and propane-1,2,-

2,3-tetraphosphonic acid; (4) Watensoluble salts of polycarboxylate polymers and copolymers as described in the copending application of Francis L. Diehl, Ser. No. 269,359, filed Apr. 1, 1963, and now U.S. Pat. 3,308,067 issued Mar. 7, 1967. Specifically, a detergent builder material comprising a water-soluble salt of a polymeric aliphatic polycarboxylic acid having the following structural relationships as to the position of the carboxylate groups and possessing the following prescribed physical characteristics: (a) a minimum molecular weight of about 350 calculated as to the acid form; (b) an equivalent weight of about 50 to about calculated as to acid form; (c) at least 45 mole percent of the monomeric species having at least two carboxyl radicals separated from each other by not more than two carbon atoms; (d) the site of attachment to the polymer chain of any carboxyl-containing radical being separated by not more than three carbon atoms along the polymer chain from the site of attachment of the next carboxyl-containing radical. Specific examples are polymers of itaconic acid, aconitic acid, maleic acid, mesaconic acid, fumaric acid, methylene malonic acid, and citraconic acid and copolymers with themselves and other compatible monomers such as ethylene; and (5) mixtures thereof.

Mixtures of organic and/or inorganic builders can be used and are generally desirable. One such mixture of builders is disclosed in the copending application of Burton H. Gedge, Ser. No. 398,705, and now U.S. Pat. 3,392,121 issued July 9, 1968, filed Sept. 23, 1964, e.g., ternary mixtures of sodium tripolyphosphate, sodium nitrilotriacetate and trisodium ethane-l-hydroxy-l,l-diphosphonate. The above described builders can also be utilized singly in this invention. Especially preferred builders that can be used singly or in combination in this invention include sodium perborate and sodium tripolyphosphate. Sodium tripolyphosphate and sodium perborate can be used in combination in a weight ratio range of from about :5 to about 50:50.

The mild detergent compositions of this invention can be used in a broad spectrum of cleaning applications. When these mild detergent compositions are formulated by excluding anionic detergents, they are especially useful in removing large amounts of blood from fabrics and particularly in preventing discoloration of the fabric by redeposition of the blood on the fabric. A specific example of the utility of this detergent composition is in removal of menstrual blood from sanitary cloths. When these particular detergent compositions are utilized for cleaning blood-soaked fabrics, further bleaching is gen erally not required in order to obtain bright and/or white fabrics.

The anionic detergents are excluded from the abovedescribed detergent compositions to prevent haemolysis or destruction of the red blood cells. The anionic detergents apparently destroy the red blood cells much more quickly and more thoroughly than do the nonionic and zwitterionic detergents. While not wishing to be bound by any particular theory, it is believed that the contents of the red blood cells are primarily responsible for discoloration of the fabric because of redeposition of the cell contents on the fabric.

The organic detergents used in the mild detergent compositions in this particular application should be selected from the group consisting of nonionic detergents and zwitterionic detergents. The nonionic detergents generally prevent redeposition of blood better than the zwitterionic detergents and are, therefore preferred. Preferred nonionic detergents include:

(I) condensation products of one mole of a saturated or unsaturated, straight or branched chain carboxylic acid having from 10 to 18 carbon atoms with from about 3 to about 50 moles of ethylene oxide;

(2) condensation products of one mole of a saturated or unsaturated, straight or branched chain alcohol having from 10 to 24 carbon atoms with from about 3 to about 50 moles of ethylene oxide; (3) polyethylene oxide condensates of alkyl phenols; (4) long chain tertiary amine oxides; long chain tertiary phosphine oxides.

The per compounds and enzymes can be used in this detergent composition in amounts described above. Proteases are the preferred enzymes; however, other enzymes can also be utilized in combination with the proteases to obtain a detergent composition having a broader use potential. Builder salts are preferably, included in the formulation. The builder salts and organic detergents are used in the ratios defined above. This mild detergent composition having special advantages in removing large amounts of blood from fabrics and being substantially free of anionic detergents comprises:

(1) nonionic or zwitterionic detergents, (2) per compounds,

(3) enzymes,

(4) builders.

The following examples serve to illustrate the invention and when read in conjunction with the foregoing description will aid in determining the full scope of the present invention. The examples are merely illustrative, and they are not intended to restrict the invention.

In the examples, enzymatic activity is determined by the Azocoll method which is based on the release of a water-soluble dye from a water-insoluble protein-dye substrate (Azocoll) by a proteolytic enzyme. The amount of dye released under carefully controlled conditions is measured spectrophotometrically. Enzymatic activity is calculated from the amount of dye released.

EXAMPLE I Four pounds of powdered sodium perborate (NaBOy H20g) were placed in a baflled laboratory cement mixer and the cement mixer was turned on. A quantity of the condensation product of coconut alcohol having a carbon chain length distribution of 2% C 66% C 23% C and 9% C and 45 moles of ethylene oxide (CNAE was heated to 135 F. at which point the CNAE was entirely liquefied. About 0.2 pound of CNAE were sprayed onto the powdered perborate which was tumbling in the cement mixer. The CNAE made the perborate powder sufiiciently sticky or glutinous to cause the formation of preborate granules having a particle size ranging as follows: 25.4% on Tyler Standard 14 mesh screen, 56.4% on Tyler Standard 20 mesh screen; 86.4% on Tyler Standard 35 mesh screen; 95.5% on Tyler Standard 65 mesh screen and 98.9% on Tyler Standard 100 mesh screen. The density of these granules was 0.5 gm./cc.

As the outside surfaces of the granules were still tacky, no additional spray-on of nonionic detergent was required. Two pounds of Alcalase, as hereinbefore described, were added to the cement mixer. The bulk temperature inside the cement mixer was about 110 F. The mixer was left on for about ten minutes at which time the enzyme, i.e., Alcalase, was firmly attached to the outside surfaces of the detergent granules. The bulk temperature at this time was 105 F.

The granules were allowed to cool to about 80 F. and were then coated with an additional 0.1 pound of CNAE This coating was applied by placing the enzyme-containing detergent granules in the cement mixer, turning it on and then spraying the liquid CNAE at a temperature of about 135 F. onto the granules. After the nonionic solidified, a small amount of blue dye was sprayed on these granules to color them a bright blue. A mixture of 1.5 pounds of these blue granules, 23 pounds of granular sodium tripolyphosphate having a density of about 0.5 gm./cc., and 25 pounds of sodium perborate: CNAE granules (95% perborate, 5% CNAE having a density Cal of 0.5 gm./cc. was then prepared which was suitable for use as a laundry additive product. The final product was granular and free flowing. The enzyme-containing particles did not segregate in the final product.

This formulation has a density of about 0.5 gm./cc. and contains about 0.06% active enzyme, i.e., about 1% Alcalase. The recommended usage level of this product in ordinary laundry washing is one-half cup per wash. When this product was utilized in an ordinary washing cycle in addition to one cup of a commercial detergent product, i.e., Tide, naturally soiled clothes were given an enhanced whiteness and, likewise, soil removal was enhanced. It was mild to the skin.

This product was stored under various conditions for one week and then the active enzyme content of the stored product was compared with the product just after conglutination. When the product was stored at 50 F. for one week, the active enzyme content was 98% as compared with the product just after conglutination. When the product was stored at F. for one week, the active enzyme content was 97%. When the product was stored in an environment which was maintained for alternate twelve hour periods at 50 F. and F. for one week, the active enzyme content was 87%. Only minor amounts of enzyme activity were lost by the product produced by the process of this invention.

EXAMPLE II A soak detergent product was prepared which had excellent cleaning and whitening characteristics and which, in addition, substantially prevented degradation of the enzymes contained in said product. Base detergent granules were prepared by agglomerating, in a pan agglomerator, 2.16 parts of powdered, anhydrous sodium tripolyphosphate with 0.24 part of the condensation product of 1 mole of tallow fatty alcohol with 30 moles of ethylene oxide (TAE Before the TAE was added to the sodium tripolyphosphate, it was liquefied by warming it to F. The average bulk density of the base granules was about 0.5 gm./ cc. The particle size distribution of the base granules was as follows:

Tyler Standard screen size: Percent on 14 0 20 1.5 28 8.4 35 14.1 58 33.0 65 24.0 100 14.0 Through 100 5.0

Component: Parts by weight Sodium tripolyphosphate (anhydrous) 70.0 Sodium perborate agglomerates comprising:

Sodium perborate 25.0 TAE 3.5

These granules had a particle size ranging from 100% through a Tyler Standard 12 mesh screen to 97% retained on a Tyler Standard 100 mesh screen. The bulk density was about 0.5 gm./cc.

This product was packaged and stored at 80 F. and ambient humidity for seven weeks. During the entire seven weeks there was essentially no loss in enzymatic activity. In another test where Alcalase was dry-mixed with the above described detergent composition and packaged in the same manner, there was about a 30% loss in enzymatic activity in a six week period. These tests demonstrate that the enzymes are protected by utilizing the conglutination method of this invention. No segregation problems were apparent.

The product of this example was primarily designed as a soaking product. Excellent cleaning and whitening benefits are obtained with this product. It had improved mildness to the skin.

EXAMPLE III Spray-dried, granular detergent compositions were prepared, comprised of the following components:

EXAMPLE III Parts by weight Deter To each of the above detergents, A(l), A(2), B(l) and EU), 0.774 part of enzyme composition was added. The enzyme composition utilized in detergents A(1) and A(2) was Maxatase while both Alcalase and Maxatase were separately utilized on a pro rata basis in separate portions of detergents Btl) and B(2). The enzyme compositions were merely dry-mixed with the detergent compositions. Immediately after mixing, these compositions were utilized in the hand immersion tests of this example.

The tests illustrated hereinafter are designed to show the relative mildness of the detergent compositions set forth above. A 2% solution of these detergent compositions is prepared. The water is maintained at 110 F. The test subjects place one hand in the above-described solution for 30 minutes on each of four successive days. On the fifth day, the subjects hands are examined.

The concentrated solutions, long immersion times and hot water are quite exaggerated testing conditions and are utilized to produce some irritative symptoms in order to facilitate grading of relative mildness. The irritative symptoms that may be observed are:

(1) Irritable redness (all of the products utilized in this test caused some irritable redness of the wrists because of the high concentration of the detergents and the long immersion times).

(2) Slight rash (this rash consisted of very minute spots which were hardly noticeable--in most cases, the rash disappeared quickly but in a few cases, the rash persisted).

(3) Heavy rash.

The first test was run utilizing detergents AU) and At'l). The detergents were the same except for the inclusion of sodium perborate in detergent A(2). Two percent solutions of detergents AU) and A(2) were prepared with 110 F. water. Sixty-four subjects were utilized in these tests, 32 in each separate test, with each subject placing one hand in the solutions for 30 minutes on each of four successive days. On the fifth day, the test hand of each subject was graded.

No irritative symptoms, i.e., slight or heavy rash, were observed on the hands of the subjects using detergent A(2). Two of the subjects using detergent A(1) suffered from a heavy rash on their hands.

Similar tests under similar conditions were run with 12 detergents B(1) and BC!) The results of these tests are tabulated below:

Detergent B (l) Detergent B (1) In the tests utilizing detergent B(1) with Maxatase and with Alcalase, the hand immersions were stopped after the second immersion because of the high irritancy potential of this solution (X=no reading). With Alcalase, 6 of the 13 subjects suffered from a slight rash and 2 suffered from a heavy rash. With Maxatase, 2 of the 16 subjects suffered from a slight rash and 4 from a heavy rash after the second immersion. When perborate was added to the system, i.e., detergent B(2), and four successive immersions utilized, only 2 subjects out of 14 suffered from a slight rash and none from a heavy rash when Alcalase was included in the detergent composition. When Maxatase was utilized, 1 subject out of 16 suffered from a slight rash and 1 suffered from a heavy rash.

A comparison of the test results using detergents EU) and 8(2) shows that the combination of enzymes and sodium perborate in detergent compositions is strikingly more mild than enzymes alone in detergent compositions. It further shows a synergistic mildness combination of sodium perborate and enzymes.

EXAMPLE IV Detergent compositions, A and B, were prepared. In both cases, all the components, except the enzymes, were mixed together in an aqueous slurry and then spray-dried. The enzymes were dry-mixed with the spray-dried granules.

Parts by weight Separate detergent solutions were prepared, each day of this test, utilizing detergents A and B. The detergents were used in concentrations of 2% in water which was maintained at F. This product concentration is coniderably higher than that used for most cleaning jobs.

To determine the relative mildness of these two detergent compositions, six subjects immersed their hands, one in each solution, for one-half hour per day on successive days. The subjects hands were graded on a scale from 1 to 10. A score of 10 indicated no reaction to the solutions. A score of l was a very violent reaction. All tests were stopped when one hand reached a grade of about 7 which indicates a moderate reaction, i.e., redness and, in some cases, a slight rash. Both hands were graded at this time and, if one hand was significantly better (one grade point in this test is a significant difference) than the hand graded as 7, that hand was reimmersed until a grade of 7 was obtained.

The following table shows the average grade of hands immersed in solutions of detergents A and B and the average number of immersions required to reach a grade of 7.

Detergent Average immersions required to reach about grade 7 (immersions equal one-half hour) 2. 8

Average grade of both hands when one hand reaches about grade 7 EXAMPLE V A granular spray-dried detergent composition having a particle size ranging from about 6% retained on a Tyler Standard 14 mesh screen to about 1.8% through a Tyler Standard 100 mesh screen and having a bulk density of 0.35 gm./cc. is prepared from the following ingredients:

Percent by weight A mixture of 55% sodium tallow alkyl sulfate and 45% sodium linear alkyl benzene sulfonate wherein the alkyl chain distribution is 16% C 27% This detergent composition is separated into four separate portions and sodium perborate and enzymes are added as shown below:

Additions by weight of detergent composition A B C D Sodium perborate, percent 10 Alcalase, percent ..0.8 0.8

Detergents B and C are considerably less mild than the control, Detergent A, while detergent D containing the combination of Alcalase and sodium perborate is as mild as the control. This test shows, again, the synergistic mildness combination of sodium perborate and enzymes, specifically, Alcalase.

EXAMPLE VI Results substantially similar to those in Examples 1H, IV and V are obtained when other per compounds are substituted, either wholly or in part, for sodium perborate in that the resulting product is surprisingly mild. The per compounds that can be substituted for sodium perborate include the sodium, potassium, lithium and ammonium persulfates, percarbonates and perborates.

EXAMPLE VII A menstrual blood solution was prepared by soaking several used sanitary napkins in water at room temperature (80 F.) for two hours. 0.4% of detergent composition by weight of the menstrual blood solution was added. The detergent composition comprised:

Percent Organic detergent (as shown below) 22 Sodium tripolyphosphate 55 Sodium perborate 22 Alcalase 1 Clean, white muslin swatches were soaked in the blood/ detergent composition solution for about 16 hours. The swatches were then rinsed with clear water, dried and measured for color on an EEL Reflectometer. The EEL units in the following table indicate the amount of redeposition with 0 units indicating a cloth with no redeposition. A difierence of 2 EEL units is noticeable to the unpracticed eye.

The EEL Reflectometer used herein is comprised of a spectrophotometer head using a No. 602 filter coupled with a Unigalvo type 20 meter. The refiectometer is built by Evans Electroselenium Ltd., Sussex, England.

TABLE I.-BLOOD REDEPOSITION USING NONIONIC AND ANIONIC DETERGENT COMPOSITIONS Percent Percent condensation sodium product of one mole linear alkyl of tallow alcohol and (Cu), benzene 11 moles of ethylene Cloth color, sulfonate(LAS) oxide (TAEH) EEL reading Units darker than original muslin cloth.

As can be seen from the above table, redeposition of blood on the fabric is significantly increased by using an anionic detergent. When TAE a nonionic detergent, was the only organic detergent present in the detergent composition, the EEL reading was 16. An EEL reading of 34 was obtained when 50% of the TAB was replaced with LAS, an anionic detergent. The difference of 18 EEL units between the cloths represents a significant color differential.

When the following nonionic detergents are substituted for TAE the results are similar to those tabulated above in that there is less redeposition of blood on the fabric when nonionic detergents are the sole organic detergent in the detergent composition than when anionic detergents are utilized in the detergent composition: dimethyl dodecyl phosphine oxide; dimethyl dodecyl amine oxide; the condensation product of one mole of tallow alcohol and 30 moles of ethylene oxide; the condensation product of one mole of coconut alcohol with 5.5 moles of ethylene oxide.

When the following anionic detergents are substituted for LAS, substantially the same results are obtained as tabulated above:

Sodium branched chain alkyl (C benzene sulfonate 20% sodium coconut soap, sodium tallow soap Coconut alkyl sulfate Tallow alkyl sulfate The foregoing description of the invention has been presented describing certain operable and preferred embodiments. It is not intended that the invention should be so limited since variations and modifications thereof will be obvious to those skilled in the art, all of which are within the spirit and scope of this invention.

What is claimed is:

1. A mild detergent composition consisting essentially of, by weight of said composition;

(1) from about 0.005% to about 4% of proteases having optimum activity in the alkaline range which do not contain sulfhydryl groups or disulfide bonds;

(2) from about 5% to about 30% of peroxy compounds selected from the group consisting of sodium, potassium, lithium and ammonium perborate, percarbonate and persulfate; and

(3) from about 70% to of a mixture of builder salts and organic detergents selected from the group consisting of soap, non-soap anionic detergents, nonionic detergents, ampholytic detergents and zwitterionic detergents in a ratio of builder salts to organic detergents of from about 1:4 to about 30:1.

2. The detergent composition of claim 1 wherein the proteases comprise from 0.006% to 0.12%; wherein the per compound is sodium perborate and comprises from 8% to 25%; and wherein the ratio of builder salts to organic detergents is from about 0.4:1 to about 15:1.

3. The mild detergent composition of claim 5 wherein the organic detergent is a nonionic detergent and is selected from the group consisting of:

(l) the condensation products of one mole of a saturated or unsaturated, straight or branched chain carboxylic acid having from 10 to 18 carbon atoms with from about 3 to about 50 moles of ethylene oxide;

(2) the condensation products of one mole of a saturated or unsaturated, straight or branched chain, alcohol having from 10 to 24 carbon atoms with from about 3 to about 50 moles of ethylene oxide;

(3) the condensation products of one mole of alkyl phenol wherein the alkyl group contains from 6 to 12 carbon atoms with from 5 to 25 moles of ethylene oxide;

(4) long chain tertiary amine oxides corresponding to the following general formula wherein R is an alkyl radical of from about 8 to about 24 carbon atoms, R and R are each methyl, ethyl or hydroxyethyl radicals, R is ethylene, and n equals from to about 10;

(5) long chain tertiary phosphine oxides corresponding to the following general formula RRR"P O wherein R is an alkyl, alkenyl or monohydroxyalkyl radical ranging from to 24 carbon atoms in chain length and R and R are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms.

4. The mild detergent composition of claim 2 wherein the protease is subtilisin from Bacillus subszirlis.

5. A mild detergent composition having special advantages in removing large amounts of blood from fabrics and being substantially free of anionic detergents consisting essentially of:

(1) from about to of a mixture of builder salts and organic detergents selected from the group consisting of nonionic detergents and zwitterionic detergents in a ratio of builder salts to organic detergents of from about 1:4 to about 30:1;

(2) from about 5% to about 30% of peroxy compounds selected from the group consisting of sodium, potassium, lithium and ammonium perborate, percarbonate and persulfate; and

(3) from about 0.005 to about 4% of proteases having optimum activity in the alkaline range which do not contain sulfhydryl groups or disulfide bonds.

6. The mild detergent composition of claim 5 wherein the protease is subtilisin from Bacillus sublilis.

References Cited UNITED STATES PATENTS 2,152,520 3/1939 Lind 252-89 FOREIGN PATENTS 282,588 12/1927 Great Britain 25295 604,990 7/1948 Great Britain 25295 1,044,766 11/1953 France 25295 234,081 12/1944 Switzerland 25295 LEON D. ROSDOL, Primary Examiner W. SCHULZ, Assistant Examiner US. Cl. X.R. 25289