US3519379A - Soaking and laundering process - Google Patents

Description

nwnsS REFERENCE 3,519,379 Patented July 7, 1970 3 519 379 of enzyme required to hydrolize 1.725 mg. casein. See also: A. Kiintzel, Gerbereichemisches Taschenbuch,

SOAKING AND LAUNDEBING PROCESS Karl F. Blomeyer, Heidelberg, Germany, and Francis J. Cracco, Brussels, Belgium, assignors to The Procter 8t gamble Company, Cincinnati, Ohio, a corporation of No Drawing. Filed Apr. 28, 1967, Ser. No. 634,489

Int. Cl. D061 3/02 US. Cl. 8-111 Claims ABSTRACT OF THE DISCLOSURE A soaking and laundering process in which a proteolytic enzyme and a peroxy compound are employed along with an organic detergent and an alkaline builder to achieve superior stain removal.

BACKGROUND OF THE INVENTION Practically all solid detergent compositions sold for household-use contain sodium perborate, which acts as an oxygen bleach compound in solution. Sodium perborate and other oxygen bleach compounds bleach out very well certain strains occuring on household laundry such as those of fruit juice, wine, tea or coffee. Other colored stains like those from eggs or aged blood are much more difficult to remove by oxygen bleaches, presumably because the protein material surrounding the coloring material will partially prevent the action of the active oxygen from the peroxy bleaching compound.

Recently proteolytic enzymes have become available commercially .which can be used successfully in solid detergent compositions. These enzymes can successfully attack protein stains, as for example egg and aged blood stains and thus increase the detergent performance of compositions containing them. Since these enzymes have normally no bleaching activity, evidently the combined action of an oxygen bleach compound and the proteolytic enzyme would be desirable. However, any effort in this direction so far failed, because investigations carried out in the past seemed to indicate. that they do not work together. The enzymatic action is; strongly inhibited by the presence of active oxygen produced by oxygen bleach compounds.

Surprisingly, it has now been found that this inhibiting action is only a temporary one and disappears practically completely after a certain time, after which the enzyme activity is again apparent. The advantages of the combined action is of course evident, particularly with the presence of colored protein stains. The enzyme prepares the way for the oxygen bleach.

SUMMARY OF INVENTION The soaking and laundering process of this invention is characterized in that the washing is carried out by:

(a) Dissolving a solid detergent composition, which, besides an organic detergent and an alkaline builder salt contains 0.5 to 4.5% available oxygen in the form of a solid peroxy compound and a proteolytic enzyme in an amount which provides from 80 to 64,000 units of proeolytic enzymatic activity (pergram of the detergent composition), and which, when dissolved in water, gives a solution with a pH of 6.5 to 10.5 and by (b) Soaking and laundering soiled laundry in this solution to act for a period of at least a quarter of an hour and preferably at least half an hour at a temperature from 1 to 60 C.

DETAILED DESCRIPTION The enzymatic proteolytic activity is expressed as the Ltiillein Volhard unit which corresponds to the amount page 85, 6th edition. Any solid detergent composition having the above-described characteristics can be used for the process of the present invention. The major components which can be incorporated therein are all commonly used organic detergents and builders, singly or in mixtures, together with oxygen bleach compounds and proteolytic enzymes.

Soiled laundry has to be soaked and laundered for a period of at least a quarter of an hour and preferably at least half an hour in order to take advantage of the combined action of oxygen bleach and proteolytic enzyme. The longer the" soaking and laundering time the better, but after a period of 8 to 16 hours (overnight soaking) hardly any additional performance can be expected anymore and no improvement is noticeable after a period of 24 hours. Soaking and laundering at room temperature is preferred, already from a practical point of view, but the combined performance is also achieved at temperatures close to 0 C. as well as at temperatures up to about 60 C. above that temperature most enzymes will be destroyed.

ENZYMES The proteolytic 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 pHIrange 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 F. 7

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

Proteolytic enzymes catalyze the addition or removal of water and degrade soil, especially of a protein type. They include hydrolyzing enzymes (hydrolases), which cleave ester linkages (carboxylic ester hydrolases, phosphoric monoester hydrolases, phosphoric diester hydrolases) or cleave glycosides (glycosidases) 0r cleave peptide linkages (a-aminopeptide amine acid hydrolases, u-carboxypeptide amino acid hydrolases). They also include hydrating enzymes (hydrases). (Hydrating enzymes can also be classed as oxiodoreductases.)

The preferred hydrolases catalyze the addition of water to the substrate, i.e., the substance such as soil with which they interact, and thus, generally, cause a breakdown or degradation of such a substrate. This breakdown of the substrate is particularly valuable in the ordinary washing procedures, as the substrate and the soil adhering to said substrate is loosened and thus more easily removed. For this reason, the hydrolases are the most important and most preferred class of enzymes for use in cleaning applications. Particularly preferred hydrolases are the proteases, esterases, carbohydrases and nucleases, with the proteases having the broadest range of soil degradation capability.

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 suitable for use in this invention are pepsin, trypsin, chymotrypsin, collagenase, keratinase, elastase, subtilisin, BPN', papain, bromelin, carboxy peptidase A and B, amino peptidase, aspergillopeptidase A and aspergillopeptidase B. 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 serine proteases which are procured by mammalian systems, e.g., pancreatin, are useful in acid situations.

-Esterases catalyze the hydrolysis of an ester, such as lipid soil, to an acid and an alcohol. Specific examples of the esterases are gastric lipase, pancreatic lipase, plant lipases, phospholipases, cholinesterases and phosphotases. Esterases function primarily in acid systems.

Carbonhydrases catalyze the breakdown of carbohy drate soil. Specific examples of this class of enzymes are maltase, saccharase, amylascs, cellulase, pectinase, lysozyme, e-glycosidase and p-glycosidase. They function primarily in acid to neutral systems.

The nucleases catalyze the breakdown of nucleic acids and related compounds, degrading residual cell soil such as skin flakes. Two specific examples of this subgroup are ribonuclease and desoxyribonuclease.

The enzymes described herein are generally utilized in a dry, powdered form. It is desirable that the enzymes be used in a dry form prior to use since degradation of the enzymes is minimized.

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 salts also stabilize enzymes. The combination of enzyme and inert vehicle usually comprises from about 2% to about 80% 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 particles of commercially available enzyme powders are fine enough to pass through a Tyler Standard l-mesh screen. Generally a major amount of particles will remain on a ISO-mesh screen. Thus, the powdered enzymes utilized herein usually range in size from about 1 mm. to 1 micron, most generally from 0.1 mm. to 0.01 mm. The enzyme 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. Other commercial products contain lipases, carbonhydrases, 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 bacterial), Rhozyme P-ll eoncentrate, Pectinol, Lipase B, Rhozyme PF, Rhozyme I-25 (Rhozyme PF and I-25 have salt and corn starch vehicles and are proteases having diastase activity), Amprozyme 200.

CRD Protease (also known as Monsanto DA-lO) is a useful powdered enzyme product. CRD-Protease is reported to be obtained by mutation of a Bacillus subtilis organism. It is about neutral portease 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 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 Streptomyces 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 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, free-flowing powder having a crystalline active enzyme content of about 6% and a particle size ranging from 1.2 mm. to .01 mm. and smaller, about 75% passing through a l00-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., ISO- 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 detcrgent compositions of this invention.

The particular enzyme chosen for use in the products and process of this invention depends on the conditions of final utility, including the pH of the materials incorporated into the base granules, use pH, use temperature and soil types to be degraded or altered. The enzyme can be chosen to provide optimum activity and/or stability for any given set of utility conditions.

Peroxy compounds tend to inhibit the activity of enzymes. The inhibiting action of the peroxy compounds is more pronounced in the case of those enzymes which contain sulfhydryl groups or disulfide bonds, e.g. pepsin, tripsin, papain, lipase, diastase and urease. Therefore, the preferred class of proteases for use in the detergent composition of the process of this invention are those which are free from sulfhydryl groups or disulfide bonds. These are exemplified by the subtilisin family of enzymes. Specific examples of these enzymes include Alcalase, Bakterie, Proteinase, Maxatase, and the alkaline protease portion of CRD-Protease.

In a preferred embodiment of this invention, the amount of active enzyme in a detergent composition is from about 0.005% to about 4.0% by weight of the compositio When the preferred enzyme, Alcalase, is

so utilized, the final detergent composition preferably contains from about 0.006% to about 0.12% active enzyme by weight. These figures correspond to a range of from about 0.1% to about 2.0% by weight of the final detergent composition of Alcalase.

The range of 80 to 64,000 L.V. units corresponds approximately to a detergent composition counting from 0.054% to 43.5% Alcalase which in turn is about 6% active enzyme.

The range of 0.5% to 4.5% available oxygen corresponds approximately to a detergent composition containing from about 5% to about 45% sodium perborate. (Sodium perborate per se contains about 10.4% avail able oxygen.) Sodium perborate is the preferred compound and is used preferably in an amount ranging from 8% to 25% of the composition. Other useful peroxy compounds are sodium persulfate and percarbonate.

In addition to the enzyme and the peroxy compound, the detergent compositions of this invention contain about to about 95% of the usual mixtures of organic detergent and alkaline builder salts in a ratio in the range of about 2:1 to 1:10. The builder salts and organic de= tergent compounds are more fully described hereinafter.

ORGANIC DETERGENTS The organic detergent compounds which can be utilized in the process 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 t1i= ethanolammonium) salts of higher fatty acids (C -C 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 nonsoap detergents. A preferred class can be broadly described as the water-soluble salts, particularly 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 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 elements. Another class has semipolar characteristics. These classes can be defined in greater detail as follows:

(1) A class of nonionic synthetic detergents marketed under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with a hydrophobic base formcd 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 -rnoles 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, witlr' iethylene oxide, e.g., a coconut alcohol-ethylene oxide condensate having from 5 to 30 moles of ethylene oxide Iper 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 ntaurally 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 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 9 to about 10. The arrow in the formula is a conventiona1 representation of a semi-polar bond. Specific examples of amide oxide detergents include dimethyldodecylamine oxide and bis-(Z-hydroxyethyl) dodecylamine oxide.

(7) Long chain tertiary phosphine oxides corresponding to the following general formula RR'R"P- 0 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 semipolar 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- (Z-hydroxydodecyl) phosphine oxide.

(8) Long chain sulfoxides having the formula wherein R is an alkyl radical containing from about 10 to about 28 carbon atoms, from to about 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 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 aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxyl, sulfo, sulfato, phosphate, or phosphono. Examples of compounds falling within this definition are sodium-3-dodecylaminopropionate and sodium- 3-dodecylaminopropane sulfonate.

(e) Zwitterionic synthetic detergents can be broadly described as derivatives of aliphatic quaternary ammonium, phos'phonium 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-lsulfonate which are preferred for their cool water detergency characteristics. See, for example, Snoddy et al., Canadian Pat. 708,148.

These soap and nonsoap 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 compositions of this invention also contain 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, bicarbonates, carbonates, tripolyphosphates, pyrophosphates, orthophosphates and hexametaphosphates.

'Exampels of suitable organic alkaline detergency builder salts are (1) Water-soluable aminopolycarboxylatesz, e.g., sodium and potassium ethylenediaminetetraacetates, nitrilotriacetates and N-(2-hydroxyethyl)-nitrilo diacetates; .(2) Water-soluble salts of phytic acid, e.g., sodium and potassium phytates-see US. Pat. 2,739,942; (3) watersoluble, polyphosphonates, including specifically, sodium, potassium and lithium salts of ethane-l-hydroxy-1,l-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-1,1,2-triphosphonic acid. Other examples include the alkali metal salts of ethane-2- carboxy-1,1-diphosphonic acid, hydroxymethanediphosphonic acid, carbonyldiphosphonic acid, ethane-l-hydroxy- 1 ,1 ,2-triphosphonic acid, ethane-2-hydroxy-1, l ,2-trlphosphonic acid, propane-l,1,3,3-tetraphosphonic acid, propane-l,l,2,3-tetraphosphonic acid, and propane-l,2,2,3-tetraphosphonic acid; (4) water-soluble salts of polycarboxylate polymers and copolymers as described in the patent of Francis L. Diehl, U.S.P. 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; ((1) 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 carboxylcontaining 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 Canadian Pat. 755,038 of Burton H. Gedge, e.g., ternary mixtures of sodium tripolyphosphate, sodium nitrilotriacetate and trisodium ethane-lhydroxy-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 tetra sodium pyrophosphate and sodium tripolyphosphate.

In the practice of this invention, it is especially preferred to use anhydrous and incompletely hydrated builder salts as described above in order to bind any free water which may come in contact with the finished granules and, thus, protect the enzymes from contact with solutions of concentrated alkaline products.

The enzyme and peroxy compound can be incorporated into the detergent composition by any of several different techniques including simple mechanical mixing.

A preferred way to incorporate the enzymes in washmg compositions is that the enzyme is first absorbed on a hydratable builder salt which is not completely hydrated and has a pH range in aqueous solution of 8 to 12 and a vapor pressure of the partly hydrated salt of less than that corresponding to 75% relative humidity, as disclosed in US. patent application Ser. No. 620,603 of Mar. 6, 1967, Roald et a1, now abandoned.

The enzymes are preferably absorbed or adsorbed on an morganic alkaline detergency builder which possesses in its parn'ally hydrated form the advantage of being a valuable enzyme carrier besides the known detergent properties. Sodium-tripolyphosphate and tetrasodium pyrophosphate are preferred compounds. The compositions can also be made according to the technique described in copendmg application of McCarty, Ser. No. 620,608, filed Mar. 6, 1967, now abandoned.

Particularly useful for the purpose of the present inyention are those compounds wherein the active oxygen 15 bound as hydrogen peroxide and which product active oxygen for bleaching in the above indicated amounts under the conditions as defined for the process of this invention.

The detergent compositions utilized in this invention may, if desired, also contain one or more materials which make the product more attractive and/or more effective. Examples of these are: soil redeposition agents such as sodium carboxymethylcellulose, colors, perfumes, and other commonly used additives and diluents such as sodium sulfate and moisture.

The surprising cleaning power obtained as a result of The following detergent compositions were prepared:

I Components percent percent dodecyl benzene sulfonate 27. 19. 0 trlpolyphosphate 27. 0 28.0 carboxymet ylcelluloe 1. 0 1.0 silicate 5. 0 5.0 perborete 0-25 0-25 Enzyme (Alcalese expressed in Liihlein-Volhard Units/gr. detergent:

Formula A: witha content of 0 to 960 LV unlts.. 0-0. 6 Formula B. 0 to 48,000 LV units 0-30 510, NBzBO4 brtghteners, perfumes"... (*l

and are immediately afterwards passed twice through a handwringer to remove excess of soil solution. They are then dried at a temperature of about 65 C. until they are completely dry. A further step consists in treating the dried swatches in water at 70 C. for 2 minutes, whereafter they are ironed with a flat iron on both sides.

The carrot stain swatches are prepared by dyeing terry cloth with carrot juice, wringing the cloth and allowing them to dry at room temperature.

The stain removal of the difierent type of swatches after soaking is measured with an EEL Spectrophotometer (Evans Electroselium Ltd. IK) whereby filter number 603 is used for blood stains and filter number 602 for carrot stains. The light reflectance is measured on the swatches before (X) and after (Y) treatment and the percent stain removal (R) is calculated along the following formula:

Alcalase: proteolytic enzyme obtained from Nova Industri AIS Y-X Denmark. 20 R 100 1 Balance to 100%. 100 X TABLE 1 Percent Perborate Soail ng Enzyme (LV units) Stain type Detergent hours 960 0 +l8.00

2 12.9 7.5 40 3.5 7.1 4.2 0.3.. llood ..11 4 23.9 11.0 7.5 13.0 15.4 9.5 0.0 s 36.2 213.0 23:4 23.5 19.0 10.4 1.1 10 30.9 29.0 28.3 29.2 25.4 23.5 1.2 2 13.5 11.8 12.5 11.3 12.0 9.3 0. Carrot 4 21.0 15.5 13.5 14.0 13.5 14.0 s 23.5 24.3 25.3 23.3 21.0 21.3 0 10 434 43.5 45.1 43.4 39.4 42.7 2 9.0 1.9 2.0. 2.3 2.1 2.1 Blood B 4 21.5 10.0 11.9 12.2 7.0 7.9 a 31.5 24.9 20.5 21.5 21.2 20.0 10 32.2 32.9 $.18 29.3 32.0 31.5 2 17.3 13.3 12.0. 12.3 11.0 10.3 Carrot B 4 19.0 15.0 11.5 11.3 12.0 11.3 s 23.3 18.5 15.0 14.0 13.0 13.0 15 35.4 30.5 38.9, 34.4 33.5 32.5

The detergent compositions A and B are prepared by TABLE 2 conventionally spray-drymg a mixture of all ingredients except the perborate which is mixed in afterwards and the enzyme which is sprayed onto sodium tripolyphos- 5 Initial 0 5 10 15 20 25 h n stain soaking, p ate and 1s also rruxed 1n afterwards. These detergent Detergent type 3 WIN units) compositions are used to prepare soaking solutions of a 30 4 M a 35. .2 33.2 32.5 32.0 31. 0.5% composition concentrat1on and a water hardness B m 3112 330 m9 2H 26.0 of 18 grams/US. gellon. Laundering can follow the soak- 35.0 31.0 23.5 25.5 22.3 20.3 mg and can be efi ected merely by removing the soaking 30 3M 3M 3 3M 3M 3M solution and I'lllSlllg the fabric. Test swatches stained B Carrot-.- 40 314 34.2 33.8 32.9 31.3 30.3 with standardized blood and carrot staining solutions as hereafter described are used for the comparative stain removal testing. The soil solutions are prepared as indicated (a) Blood staining solurion.-Add 10 gr. of sodium or ammonium citrate to 1 liter of fresh ox blood.

Prepare a mixture of: 10 parts (1 liter) of ox blood; 10 parts (1 liter) of milk; 10 parts (1 liter) of water; 3 parts (300 ml.) of drawing ink which is used as an indicator of protein stain removal.

This solution is maintained at 35 staining operation;

(b) Carrot staining soIution.--Consists of natural ju'ice which is filtered before use.

The blood stain test swatches are prepared from brightener free cotton which has been washed prior to use to desize the cotton. Batches of 10 swatches each (18 x 12 cm.) are soaked in 3.3 liters of blood soil solution for 2 minutes, taken out of the soil solution C. during the whole initial soaking temperature within the Table 1 shows the stain removal (R) results obtained on difierent kinds of protein stains whereby the enzyme level and the perborate level have been varied as indicated. The initial soaking temperature was 20' C. These results .show that under extended soaking times, the mixtures of enzymes and perborate has a proteolytic activity which is close tothat given by enzymes alone.

Table 2 indicates that the proteolytic stain removal efficiency remains essentially unchanged upon changing the normal temperature used for soaking as previously described. The initial soaking temperature is not maintained and the soaking solution is left overnight at ambient temperature and thus cools gradually down to 20 C.

Comparable results are obtained by replacing Alcalase by any of the following enzyme preparations:

Trade name Manufacturer Maxatase 40,000 Koninklijke Nederlandse Maxatase 200,000 Gis't. en spiritusfabriek Maxatase 300,000 N.V.--Netherlands.

Protease B 400 Protease B 4,000 Schweizerische Ferment Protease AP AG-Switzerland.

Protease AP 2,100

ATP 40 AT 120 ETS Rapidase, Seclin,

ATP 160 France.

Bakterie Protcinase Novo lndustri A/S.

EXAMPLE 2 The following detergent composition is prepared, as described for the detergent compositions under Example 1.

Composition: Percent Sodium-Linear dodecyl benzene sulfonate 11.0 Sodium Tallow/Coconut (80/20) soap 2.5

Coconut fatty alcohol-ethylene oxide condensate with 6 moles of ethylene oxide 2.0 Sodium tripolyphosphate 36.0 Sodium silicate 7.0

Sodium carboxymethylcellulose L 1.0 Sodium perborate to 12.5 Proteolytic Enzyme (content corresponding to 960 LV units=0.6% (Alcalase) 0 to 0.6 H 0, brightener, perfume Balance to 100 Na SO water Performance tests are carried out under the following conditions:

Prewash and main wash-A 4 kg. drum washing machine is used for a one-lye process. The water used has a hardness of 18 grains/US. gallon. The washing machine is loaded with 4 kg. of the soiled household clothes to be tested which are first prewashed (rinsed) for 6 minutes with cold water without product. Then" 180 gr. of the detergent product is added and the main wash is started by increasing gradually the temperature from 15 C. to 60 C. over a 30-minute period and from 60 to 100 C. over a further 30-minute period.

The testing data are:

TABLE 4 Detergent used Perborate reent Enzyme (1.. units) whiteness The results represent the sum of the gradings given by a panel of 4 independent judges, who are experts in cleaning evaluations, by grading the pairs (ac) and (be). Each pair of towels is graded on 9 replicates and each pair of shirts on 6 replicates. A standard scale of -3, 2, -1, 0, l, 2 and 3 is used wherein 0 means that the cloths are equal, 1 means there is a slight difierence, 2 means there is a moderate difference and 3 means there is a large difference. The minus (plus) value indicates that the chosen standard is better (worse) than the test swatch. The results show the surprising and uniform cleaning power of the composition containing both, enzymes and available oxygen over what is achieved with compositions containing only one of these.

12 EXAMPLE 3 A detergent composition according to formula A of Example 1 is prepared. The perborate and the enzyme are added afterwards in amounts as indicated in Table 5. These are then used for comparative performance tests.

The test conditions are:

Saak.1.5 kg. of soiled laundry clothes are soaked overnight (18 hours) in 10 liters of water (12 grains/ U.S. gallon) with a 0.5 weight-percent detergent concentration.

Wash-4.5 kg. of soiled household clothes, which have been soaked previously is washed during 4 minutes at 50 C. in a top loading agitator washing machine containing 38 liters of a detergent solution with a 0.5 weightpercent detergent concentration and a water hardness of 12 grains/US. gallon.

TABLE 6 Detergent used.-. Formula A, example 1, except Perborate, sercentn 12. 5 0 12. 5 Enzyme L uni 0 960 960 Terrgltogielsz ea ng 0 6 21 whiteness. 0 5 $18 glletggfn towe 11g 0 +12 1 whiteness 0 -9 i1 Shirtsfileaning:

Co ars 0 +3 +6 Cufis 0 +10 +8 whiteness 0 -11 The grading is carried out as described for the results mentioned in Example 2, Table 4, whereby (a) is taken as reference and three replicate gradings are taken into consideration for each pair. The superior cleaning of detergents containing both enzymes and perborate becomes readily understandable by comparing (c) with (a) and (b).

What is claimed is:

1. A soaking and laundering process comprising the steps of:

(a) dissolving a solid detergent composition which consists essentially of a water-soluble organic detergent selected from the group consisting of soap, nonsoap anionic detergent, nonionic detergents, ampholytic detergents and zwitterionic detergents; a water-soluble builder salt selected from the group consisting of inorganic alkaline builder salts and organic alkaline builder salts; from 0.5% to 4.5% available oxygen in the form of a solid inorganic peroxy compound; and proteolytic enzyme in an amount which provides from to 64,000 units of proteolytic enzymatic activity per gram of detergent composition; and which, when dissolved in water, gives a solution with a pH of 6.5 to 10.5; and

(b) soaking and laundering soiled laundry in this solution for a period of at least a quarter of an hour at a temperature from 1 C. to 60 C.

2. The process of claim 1, the period in step (b) is at least a half an hour.

3. The process of claim 1 wherein the peroxy compound is sodium perborate.

4. The process of claim 3 wherein the proteolytic enzyme is a subtilisin from Bacillus subtilis.

5. The process of claim 3 wherein the alkaline builder salt is sodium uipolyphosphate.

References Cited UNITED STATES PATENTS n,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 519 379 July 7 1970 Karl F. Blomeyer et a1.

s in the above identified It is certified that error appear rrected as shown below:

after line 7 the printed specification,

In the heading to application Germany, Aug. 24

insert Claims priority,

Signed and sealed this 23rd day of March 1971.

[SEAL] Attest:

EDWARD M. FLETCHER,JR. WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Attesting Officer