US 3789001 A
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3,789,001 DETERGENT CONTAINING ENZYME AND COARSE PERBORATE PARTICLES Daniele Painelli, Rome, Italy, assignor to Colgate- Palmolive Company, New York, N-Y. No Drawing. Filed Mar. 9, 1972, Ser. No. 233,311
Int. or. one 7/56 us. 01. 252-99 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a biological detergent composition containing an enzyme. More particularly, the invention relates to a biological enzyme detergent composition containing an enzyme and a water-soluble inorganic percompound in which the stability of the enzyme is substantially improved through the use of percompound of particular size.
The use ofiggylnismandsparticularly proteolytic enzymes as assistants in the laundering of clothes with detergent compositions has long been known in the art. While compositions containing water-soluble inorganic percompounds such as sodium perborate, have been suggested, the art has taught that the presence of the perborate has an inhibitory effect on the enzyme action, at least during the early period after the detergent composition is placed in water. Moreover, the inhibitory effect may remain at least in part even after the passing of considerable time, such as after soaking overnight.
It is an advantage of the instant invention that the enzyme is rendered considerably more stable in a detergent composition which also contains a percompound. Additional advantages of this invention will be apparent from the consideration of the following disclosure.
In accordance with certain of its aspects, this invention relates to a biological cleaning composition containing a water-soluble synthetic, organic surface-active agent, an enzyme and a water-soluble inorganic percompound, having a size such that at least about 50% of the particles thereof are retained on a screen having sieve openings of 0.42 mm. and less than about of the particles pass through a screen having sieve openings of 0.177 mm.
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. Generally, the enzymes are effective in a pH range of about 4-12, and are effective even at moderately high use temperatures. They are also effective at ambient temperature and temperatures above about 10 C. Particular examples of proteolytic enzymes which vmay be used in the instant invention include pepsin,
trypsin, chymotrypsin, papain, bromelin, colleginase, keratinase, carboxylase, amino peptidase, elastase, subtilisin and aspergillopepidase A and B. Preferred enzymes are subtilisin enzymes manufactured and cultured 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 subtilis.
United States Patent 0 ice 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 also of interest.
The production of various proteolytic enzyme concentrates is described in the patent literature: For example in Laid Open German specification 1,800,508 and in published Netherlands patent application 6815944.
The enzymes described in Laid Open German specification 1,800,508 are proteases of the serine type produced by culture of the genus Bacillus and show optimum proteolytic activity against hemoglobin at a pH higher than 9 (e.g. pH 10, 10.5, 11 or 12). Particularly suitable is the enzyme designated in that specification as C372 or the enzyme sold by Novo Industry A/S as SP-72. It is noteworthy, that this serine type of enzyme is highly effective with inorganic percompounds in accordance with this invention.
The enzyme preparations are generally extremely fine powders. In a typical powdered enzyme preparation the particle diameter generally ranges from 0.01 mm. to 0.15 mm., e.g., about 0.1 mm. and as much as of the material may pass through a 100 mesh (U.S. Standard) sieve. On the other hand the spray dried granules are usually of very much larger particle size, with the major portion of the granules being from about 0.2 mm. to 2.0 mm. in diameter.
The enzyme preparations are generally diluted with inorganic salts, e.g., alkali metal and alkaline earth metal salts. Typically the enzyme comprises from 1% to by weight of the enzyme preparation. For example, a typical Alcalase enzyme material analyzes (by weight) 6.5% enzyme, 4% water, 70% sodium chloride, 15.5% sodium sulfate, 3.5% calcium sulfate, and 0.5% organic impurities. Chemically they are typically stable in the pH range of 5 to 10, particularly at an alkaline pH of 8.0 to 9. Generally, they are effective against various types of soil in an aqueous medium having a temperature of about 20 C. to about 80 C. Naturally, different proteolytic enzymes have different degrees of effectiveness in aiding in the removal of specific 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 amount of enzyme product present in the detergent composition will, of course, depend to some extent on the amount of detergent composition which is to be added to the wash water. For detergent compositions which are intended for use in concentrations of about 0.15% in the wash water of an automatic home laundering machine, one suitable amount of granular enzyme product is such as to provide one Anson unit of alkaline centration may correspond to about 0.003-0.012 Anson units per liter of wash water, or in a detergent formulation designed for use at a concentration of 1.5 grams per liter of wash water, about 0002-0008 Anson units per gram of detergent formulation. Typically the enzyme amounts to about 01-10% by weight of the detergent.
' ing water on a blend of enzyme and hydratable builder salt to hydrate the salt and form granules. The binding of enzyme and detergent builder salt such as sodium tripolyphosphate may also take place by granulating an enzyme preparation and the hydratable builder salt in the presence of ice particles at a temperature below about 30 C. to produce a granule in which the hydratable builder salt is substantially completely hydrated and the thermal degradation of the enzyme is minimized.
Another alternate process for producing a granular enzyme product comprises granulating an enzyme in particulate form and a builder salt in particulate form with an aqueous solution of a nonionic organic surface-active agent using an amount of water at least sufiicient to substantially completely hydrate the builder salt.
A further highly desirable process for producing enzyme product of reduced dustiness comprises spraying a blend of molten nonionic detergent and enzyme concentrate into cool air to form tiny spherical beads.
Further techniques and process for producing granular enzyme products of reduced dustiness are known to those skilled in the art.
In accordance with this invention, the water-soluble percompound may be an alkali metal perborate such as sodium perborate tetrahydrate, sodium perborate monohydrate, lithium perborate, potassium perborate, barium perborate, calcium perborate, as well as water soluble alkali metal and alkaline earth metal percarbonates, perphosphates, and persulfates.
The preferred percompounds are sodium perborates.
A preferred range of proportions of the perborate is one which provides a concentration of percompound in the wash water equivalent to about '1 to 60 p.p.m., more preferably about 4 to 50 p.p.m., e.g., 7 to 45 p.p.m., of available oxygen; about 45 p.p.m. have thus far given best results. In sodium perborate tetrahydrate (NaBO -4H O) the available oxygen content (or peroxy oxygen content) is about 10% i.e., one atom of available oxygen per molecule'of the perborate. The proportions of perborate for use in the detergent formulation can therefore readily be calculated if one knows how much of the total formulation is to be added to the wash water. Commercial detergent formulations are often designed for use in proportions in the range of about 01-02% in the Wash water (e.g. at 0.15% concentration), a preferred detergent formulation containing sodium perborate tetrahydrate designed for use at the 0.15% concentration in the wash water will therefore contain approximately 5 to 30% of that compound, corresponding roughly to the 7 to 45 p.p.m. of available oxygen.
In accordance with this invention, the size of the particles of percompound employed is such that at least 50% of the particles are retained on a screen having sieve Openings of 0.42 mm. and less than about 5% of the particles are small enough to pass through a screen having sieve openings of 0.177 mm. The larger particles of perborate should be such that they are sufiiciently soluble to easily dissolve in water with the remainder of the detergent, and that they do not segregate from other components of the detergent mixture. Typically, substantially all the particles which pass through a screen having sieve openings of 0.84 mm. as larger particles would tend to segregate.
If the percentage of particles of percompound which pass through a screen having sieve openings of 0.177 mm. is substantially greater than 5%, some improvement in enzyme stability may be noted so long as at least half of the particles would be retained on the screen having sieve openings of 0.42 mm. Substantially improved enzyme stability is apparent when the percentage of small particles pass through a screen having sieve openings of 0.177 mm. is less than about 5% and particularly when there are ubstantially no fines at all which pass through a screen having sieve openings of 0.177 mm.
The degree of improvement of enzyme stability may also vary somewhat depending on the type of enzyme employed. Thus, the stability of enzyme as obtained commercially would differ from enzymes which are bound to builder salts by various techniques. There would be differences depending upon the particular technique also. However, regardless of the form of the enzyme, stability is. substantially improved when percompound in accordance with the invention is employed.
The organic surface active component of the aforementioned washing products may be an anionic, nonionic or amphoteric surface active compound or a mixture of two or more of the foregoing agents may be used.
The anionic surface active agents include those surface active or detergent compounds which contain an organic hydrophobic group and an anionic solubilizing group in their molecular structure. Typical examples of anionic solubilizing groups are sulfonate, sulfate, carboxylate, phosphonate and phosphate.
Examples of suitable anionic detergents which fall within the scope of the anionic detergent class include the water-soluble salts, e.g., the sodium, ammonium, and alkylolammonium salts, of higher fatty acids or resin acids containing about 8 to 24 carbon atoms, perferably 10 to 20 carbon atoms. Suitable fatty acids can be obtained from oils and waxes of animal or vegetable origin, e.g., tallow, grease, coconut oil, tall oil and mixtures thereof. Particularly useful are the sodium and potassium salts of the fatty acid mixtures derived from coconut oil and tallow, e.g., sodium coconut soap and potassium tallow soap.
The anionic class of detergent also includes the watersoluble sulfated and sulfonated synthetic detergents having an alkyl radical of 8 to 26, and preferably about 12 to 22 carbon atoms, in their molecular structure. (The term alkyl includes the alkyl portion of the higher acyl radicals.)
Examples of the sulfonated anionic detergents are the higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing from 10 to 16 carbon atoms in the alkyl group in a straight or branched chain, e.g., the sodium, potassium and ammonium salts of higher alkyl benzene sulfonates, higher alkyl toluene sulfonates, higher alkyl phenol sulfonates, and higher alkyl naphthalene sulfonates. A preferred sulfonate is linear alkyl benzene sulfonate having a high content of 3- (or higher) phenyl isomers and a correspondingly low content (well below 50%) of 2- (or lower) phenyl isomers, i.e., wherein 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 US. Pat. 3,320,174.
Other suitable anionic detergents are the olefin ulfonates, including long chain alkene sulfonates, long chain hydroxyalkane sulfonates or mixtures of alkenesulfonates and hydroxylalkane-sulfonates. These olefin sulfonate detergents may be prepared in a known manner by the reaction of S0 with long chain olefins containing 8 to 25, preferably 12-21, carbon atoms and having the formula RCHz-CHR where R is a higher alkyl group of 6 to 23 carbons and R is an alkyl group of 1 to 17 carbons or hydrogen to form a mixture of sultones and alkene-sulfonic acids which is then treated to convert the sultones to sulfonates. Other examples of sulfate or sulfonate detergents are paraffin sulfonates containing about 10-20, preferably about 15-20, carbon atoms, e.g., the primary paraflin sulfonates made by reacting long chain alpha olefins and bisulfites and parafiin sulfonates having the sulfonate groups distributed along the paraffin chain as shown in U.S. Pats. 2,503,280, 2,507,088; 35,260,741; 3,372,188 and German Pat. 735,096; sodium and potassium sulfates of higher alcohols containing 8 to 18 carbon atoms such as sodium lauryl sulfate and sodium tallow alcohol sulfate; sodium and potassium salts of-- sulfofatty acid esters containing about to 20 carbon atoms, e.g., methyl sulfomyristate and methyl sulfotallowate; ammonium sulfates of monoor di-glycerides of higher fatty acids, e.g., stearic monoglyceride monosulfate; sodium and alkylolammonium salts of alkyl polyethenoxy ether sulfates produced by condensing 1 to 5 moles of ethylene oxide with one mole of higher (Cg-C13) alcohol; sodium higher alkyl glyceryl ether sulfonates; and sodium or potassium alkyl phenol poly ethenoxy ether sulfates with about 1 to 6 oxyethylene groups per molecule and in which the alkyl radicals contain about 8 to about 12 carbon atoms.
The suitable anionic detergents include also the acyl sarcosinates (e.g., sodium lauroylsarcosinate), sodium and potassium salts of the reaction product of higher fatty acids containing 8 to 18 carbon atoms in the molecule esterified with isethionic acid, and sodium and potassium salts of the higher fatty acid amide of methyl taurine, e.g., sodium cocoyl methyl taurate and sodium stearoyl methyl taurate.
Anionic phosphate surfactants in which the anionic solubilizing group attached to the hydrophobic group is an oxyacid of phosphorous are also useful in the detergent compositions. Suitable phosphate surfactants are the sodium, potassium and ammonium alkyl phosphate esters such as (R-O) PO;,M and ROPO M in which R represents an alkyl chain containing from about 8 to about 20 carbon atoms or an alkyl phenyl group having 8 to 20 carbon atoms and M represents a soluble cation. The compounds formed by including about one to 40 moles of ethylene oxide in the foregoing esters, e.g., [RO(Et0) -PO M, are also satisfactory.
The particular anionic detergent salt will be suitably selected depending upon the particular formulation and the proportions therein. Preferred salts include the ammonium, substituted ammonium (mono, diand triethanolarnmonium), 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 nonionic synthetic organic detergents are generally the condensation product of an organic aliphatic or alkyl aromatic hydrophobic compound and hydrophilic ethylene oxide groups. Practically any hydrophobic compound having a carboxyl, hydroxy, amido, or amino group with a free hydrogen attached to the nitrogen can be condensed with ethylene oxide to form a nonionic detergent. Further, the length of the polyetheneoxy chain can be adjusted to achieve the desired balance between the hydrophobic and hydrophilic elements.
The nonionic detergents include the polyethylene oxide condensate of one mole of alkyl phenol containing from about 6 to about 12 carbon atoms in a straight or branched chain configuration with about 5 to 30 moles of ethylene oxide, e.g., nonyl phenol condensed with 9 moles of ethylene oxide, dodecyl phenol condensed with 15 moles of ethylene oxide and dinonyl phenol condensed with 15 moles of ethylene oxide. Condensation products of the corresponding alkyl thiophenols with 6 to 30 moles of ethylene oxide are also suitable.
Also included in the nonionic detergent class are the condensation products of a higher alcohol containing about 8 to 22 carbon atoms in a straight or branched chain configuration condensed with about 5 to 30 moles of ethylene oxide, e.g., lauryl-myristyl alcohol condensed with about 16 moles of ethylene oxide.
Another well known class of nonionic detergents is the condensation product of ethylene oxide on a hydrophobic base formed by the condensation of propylene oxide and propylene glycol. These materials are sold under the trade name Pluronic. The molecular weight of the hydrophobe ranges from about 1,500 to 1,800 and the polyethylene oxide content may comprise up to 50% of the total weight of the condensate.
Other nonionic detergents include the ethylene oxide addends of monoesters of hexahydric alcohols and inner ethers thereof with higher fatty acids containing about 10 to 20 carbon atoms, e.g., sorbitan monolaurate, sorbitan monooleate, and mannitan monopalmitate.
The amphoteric detergents which can be used in the compositions of this invention are generally water-soluble salts of derivatives of aliphatic amines which contain at least one alkyl group of about 8 to 20 carbon atoms and an anionic water solubilizing carboxyl, sulfo or sulfate group in their molecule.
The suitable ampholytic or amphoteric detergents which can be used in the compositions of thi invention generally contain a hydrophobic alkyl group of about 8 to 18 carbon atoms, at least one anionic water-solubilizing group, e.g., carboxy, sulfo, sulfato, phosphato, or phosphono, and at least one cationic group, e.g., nonquaternary nitrogen, quaternary ammonium, or quaternary phosphonium group, in their molecular structure. The alkyl group may be straight chain or branched'and the specific cationic atom may be part of a heterocyclic ring.
Examples of suitable ampholytic detergents include the alkyl betaaminopropionates, RN(H)C H COOM; the alkyl betaiminodipropionates, RN(C H COOM) and the long chain imidazole'derivatives having the following formula:
CH N CH: W R- i J I I4:COOM 1" wherein R is an alkyl group of about 8 to 18 carbon atoms, W is selected from the group of R OH, R OM and R OR COOM, Y is selected from the group consisting of OH, R SO and R OSO R is an alkylene or hydroxyalkylene group containing 1 to 4 carbon atoms, R is selected from the group consisting of alkyl, alkyl aryl and fatty acyl glyceride groups having 6 to 18 carbon atoms in the alkyl or an acyl group, and M is a water-soluble action, e.g., alkali metal, ammonium or alkylolammonium. Preferred detergents are sodium N- lauryl betaaminopropionate, disodium N-lauryl iminodipropionate, and the disodium salt of 2-laurylcycloimidium-l-hydroxyl, l-ethoxyethanoic acid, l-ethanoic acid. Other imidazole detergents are described in U.S. 2,773,068; U.S. 2,781,354 and U.S. 2,781,357.
Other suitable amphoteric detergents are the sultaine and betaine types having the following general structure:
wherein R is an alkyl group containing about 8 to 18 carbon atoms, R 'and R are lower alkyl groups containing 1 to 3 carbon atoms, R, is an alkylene or hydroxyalkylene group containing about 1 to 4 carbon atoms, and
X is an anion selected from the group consisting of SO =(sultaine) and COO=(betaine). Preferred compounds are l-(myristyl dimethylammonio) acetate and 1- (myristyl dimethylammonio) 2-hydroxypropane-3-sulfonate.
Another class of suitable amphoteric detergents is the amphoteric imidazoline having the following structure:
wherein R is a higher acyclic group of 7 to 17 carbon atoms. The acyclic groups may be derived from coconut oil fatty acids (a mixture of fatty acids containing 8 to 18 carbon atoms), lauric fatty acid, and oleic fatty acid and the preferred groups are C -C alkyl groups.
The surface active agent is typically present in amount of about -95% by weight, preferably about -25%.
Various other materials may be present in the washing 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 2-3 carbons in each alkanol group attached to a fatty acyl radical containing 10-18 carbons (preferably 10-14 carbons), such as lauric or myristic monoethanolamides, diethanolamides and isopropanolamides.
Other suitable foam builders are the tertiary amine oxides of the general formula R R R N 0 wherein R is an alkyl radical of about 10 to 18 carbon atoms, R and R are alkyl or hydroxyalkyl groups containing 1 to 3 carbon atoms, and the arrow represents a semipolar bond. Included among the satisfactory amine oxides are lauryl dimethyl amine oxide and myristyl dimethyl amine oxide.
In addition to the materials described above, the additional builders for the detergent include the water-soluble inorganic builder salts commonly known in the art, or it may be a water-soluble organic sequestering agent such as sodium nitrilotriacetate, or mixtures thereof. Sodium citrate may be used.
The water-soluble inorganic builder salts may be suitable alkali metal, alkaline earth metal, or heavy metal salt or combinations thereof. Ammonium or an ethanolammonium salt in a suitable amount may be added also, but, generally the sodium and potassium salts are preferred. Examples are the water-soluble sodium and potassium phosphates, silicates, carbonates, bicarbonates, borates, sulfates and chlorides. Particularly preferred builder salts are the alkaline builder salts such as polyphosphates, silicates, borates, carbonates, etc.
In the water-soluble inorganic builder salt mixtures used in the detergent compositions, it is often preferred to have present a mixture of sodium tripolyphosphate and sodium or potassium bicarbonate, such as a combination or mixture of salts wherein the bicarbonate to tripolyphosphate ratio is selected from the range of about 1:1 to about 3: 1.
Both Phase I and Phase II sodium tripolyphosphate and mixtures thereof may be successfully used in the compositions. The usual commercial tripolyphosphate consists mainly of the Phase H material. The commercial tripolyphosphate material is usually essentially tripolyphosphate, e.g., 87-95%, with small amounts, e.g., 4-13% of other phosphates, e.g., pyrophosphate and orthophosphate. Sodium tripolyphosphate in its hydrated form may be used also. Trisodium orthophosphate may be used in the amounts indicated.
The sodium or potassium bicarbonate is an eflective pH buffer. The bicarbonate may be incorporated directly as anhydrous bicarbonate or in the form of sesquicarbonate a hydrate containing both bicarbonate and carbonate.
Generally, when present the builder salt is employed in amount in the range of about 20-90%, preferably at least 25% (e.g., 35 to 80%) of the detergent composition.
Fatty alcohols of 10-18 carbon atoms such as lauryl or coconut fatty alcohols, or cetyl alcohol are suitable additives also. A hydrotropic material such as the lower alkyl aryl sulfonates, e.g., sodium toluene or oxylene sulfonates, can assist processing also. In general, these materials and the foregoing foam builders are added in minor amounts, usually from about /2 to 10%, preferably 1 to 6%, based on the total solids.
If desired, the product of the invention may also include an activator for the precompound, such as perborate activator.
The perborate activators are a well known class of materials. Those of greatest importance which may be used in the practice of this invention are compounds which are percarboxylic acid precursors. Such compounds include esters and anhydrides and acyl amides. 'Examples of suitable activators 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-napthoyl succinimide N-benzoyl glutarimide N-p-chlorobenzoyl succinimide N-benzoyl succinimide N-p-chlorobenzoyl-5,5-dimethyl hydantoin N-o-chlorobenzoyl succinimide N-p-chlorobenzoyl phthalimide.
Further examples of suitable activator compounds or the imide type, both cyclic and aliphatic, have the following structural formula:
0 Rr-(ii-OR wherein R represents alkyl and preferably lower alkyl of l to 4 carbon atoms or aryl such as phenyl and R represents an N-bonded imide radical. Thus, included within the foregoing structural formula are the following:
N-methoxycarbonyl saccharide N-methoxycarbonyl phthalimide N-ethoxycarbonyl phthalimide N-methoxycarbonyl-S,S-dimethyl hydantoin N-methoxycarbonyl succinimide N-phenoxycarbonyl succinimide N,N-di-(methoxycarbouyl) acetamide N-methoxycarbonyl glutarimide 1,3-di- (N-methoxycarbonyl -hydantoin 1,3-di-(N-methoxycarbonyl)-5,5-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 heterocyclic 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-iidimethyl hydantoin N-m-chlorobenzoylsuccinimide.
Another group of activator compounds comprises N-sulfonated cyclic imides including those of the following structural formula:
wherein R represents lower alkyl of from 1 to 4 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 A further class of activator compounds comprises alkyl and aryl chloroformate derivatives, including for example:
Methylchloroformate Ethylchloroformate Phenylchloroformate 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 percompound being used. For reactive aromatic monoacyl compounds such as metachlorobenzoyldimethylhydantoin and metachlorobenzoylsuccinimide, 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 percompound. By increase of the mol ratio of available oxygen to activator, milder bleaching is obtained particularly when the ratio is greater than 2:1. For reactive aliphatic polyacylated compounds such as tetra-acetyl ethylenediamine, tetra-acetyl hydrazine, triacetyl cyanurate, the mole ratio of available oxygen to activator is preferably 2:1, although higher (e.g., 6: 1) or lower (e.g., less than 1: 1) mol ratios may be employed.
The mixtures may also contain optical brightening agents or fluorescent dyes (e.g., amounts in the range of about V to 35%); germicidal ingredients such as halogenated carbanilides, e.g., trichlorocarbanilide, halogenated salicylanilide, e.g., tribromosalicylanilide, halogenated bisphenols, e.g., hexachlorophene, halogenated trifluoromethyldiphenyl urea, zinc salt of 1-hydroxy-2- pyridinethione and the like (e.g., in amounts in the range of about to 2%); soil-suspending agents such as sodium carboxymethyl cellulose or polyvinyl alcohol, preferably both, or other soluble polymeric materials, such as methyl cellulose (the amount of suspending agent being in the range of about to 2%); antioxidants such as 2,6-di-tert-butylphenol or other phenolic antioxidant materials (e.g., in amounts in the range of about 0.001 to 0.1%); coloring agents; bleaching agents; and other additives.
A particularly suitable composition, for use as a granular detergent material contains builder salt such as sodium tripolyphosphate and a mixture of a linear alkylbenzenesulfonate, as previously described, soap and a nonionic detergent, with the soap and nonionic detergent being present in minor proportions. About 50 to 1000 parts by weight of builder salt are employed per 100 parts by weight of the mixture of linear alkylbenzenesulfonate, soap and nonionic detergent. The ratios of the amounts of (A) soap, and (B) nonionic detergent, to (C) the total amount of the synthetic anionic sulfonate detergent in the mixture are preferably as follows: AzC, about 1:10 to 1:2; preferably about 1:4 to 1:6, on an anhydrous basis; BzC, about 1:10 to 1:3, e.g., about 1:4 to 1:6, on an anhydrous basis. The component (C) is preferably solely a linear alkylbenzenesulfonate although it may comprise a blend of the linear alkylbenzenesulfonate detergent with other anionic synthetic sulfate or sulfonate detergents (e.g., olefin sulfonates, parafiin sulfonates having the sulfonate groups distributed along the parafiin chain, or alkyl sulfates) with the alkylbenzenesulfonate constituting, say /3, /2 or 36 of this blend.
The following examples are given to illustrate this invention further. In these examples, all proportions are by weight unless otherwise specified.
EXAMPLE 1 The following detergents are prepared:
The enzymatic granules are prepared from a blend of 3.455 parts of sodium tripolyphosphate and 0.345 part of the subtilisin enzyme Alcalase (1.5 AU/ g.) which is mixed in an air mixer unit and brought into contact with a spray 0.130 part of the condensation product of 1 mole of nonyl phenol and 9 moles of ethylene oxide in solution in 1.020 parts of water in a Grun spray-mixer. The thus formed granules are aged to permit hydration of the sodium tripolyphosphates.
The proteolytic enzyme preparation used has a maximum proteolytic activity at a pH of 8-9. This activity as measured at pH 7.5 on the commercial enzyme preparation available from Novo Industri A/ S, Copenhagen, Denmark, is about 1.5 Anson units per gram of the enzyme. The commercial enzyme preparation is a raw extract of Bacillus subtilis culture and contains about 6% of pure crystallized proteolytic material. The preparation is extremely fine and contains about 6% 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% or even 75% of the material may be below 0.15 mm. The preparation contains about 70% of sodium chloride and about 15-18% of sodium sulfate and has an organic content of about 11%.
The sodium perborate fractions used in each of the two detergents, above, are prepared in Koson unit continuous screen device and are dry blended in an amalgamator.
Each of the detergents are packaged and aged at 43 C. for four weeks and at room temperature.
No enzymatic loss is detected with either of the deterwhile the loss in enzyme activity with Detergent A containing the coarser perborate is only 17.1%.
EXAMPLE 2 Two additional detergents are prepared identical to those of Example 1 except that sodium perborate tetrahydrate of the particle size distributions indicated below are dry blended in an amalgamator and employed:
Detergent Diameter of perborate particles D% Greater than 1.68 mm Nil Nil 0.84-1.68 mm 0. 1 Nil 0.42-0.84 mm- 60. 6 52. 3 0.25-0.42 mm 28.3 28.4 0.177-0.25 mm- 9. 2 9. 3 0149-0177 mm 1.2 1.7 0074-0149 mm 0. 6 6. l 0.044-0074 mm Nil 2. 0 Less than 0.044 m Nil 1. 1
Detergent D in which the amount of fine particles having a diameter of less than 0.177 mm. exceeds suffers an enzyme activity loss of 29.6% after packaging and storing for four weeks at room temperature and of 46.89% at 43 C., while Detergent C, having less content of fines has its enzyme activity decreased by only 6.0% after packaging and storing for four weeks at room temperature and 20.0% at 43 C. 7
EXAMPLE 3 The following detergents are prepared:
Parts Component E F G Sodium dodecylbenzene sulfonate 0.92 0. 92 0. 94 Sodium tallow soap 1. 54 1. 54 1. 51 Sodium silicate (NazO/ZSiOr) 1. 54 1.54 1. 56 Sodium tripolyphosphate 12.80 12. 80 12.59 Sodium carboxymethyl cellulose 0. l5 0. 15 0.15 Ethoxylated ell-C15 alcohol (11:1 E0)- 0.66 0.66 0. 64 Moistur 2. 04 2. 04 2. 05 Enzyme granules (1.6 AU/g., 2% moisture) 0.25-0.42 m 0. 18 0. 18 0. 18 Ethoxylated C r-C15 fatty alcohol (50:1 150)..-. 0.96 0.96 0.96
Sodium perborate tetrahydrate. as indicated below.
Detergent Diameter of perborate particles E% F% (3% Greater than 1.68 mm Nil 0.84-1.68 mm.. 0.1 0.42-0.84 mm- 13. 9 0.25-0.42 mm- 66. 5 0.177-0.25 mm 19. 5 0.1490.177 mm- Nil 0074-0149 mm. Nil 0.044-0074 mm- Nil Less than 0.044 mm Nil After packaging and aging for four weeks at room temperature none of Detergents E, F and G reveal loss of enzyme activity. After packaging and aging for four weeks under accelerated aging conditions at 43 C., Detergent F, which has a large proportion of fine particles suifers an enzyme activity loss of 50.6%; Detergent E which contains a large proportion of coarse particles but also contains more than 5% of very fine particles reveals an enzyme activity loss of 42.1%; Detergent G which contains a large proportion of coarse particles and substantially no files has a loss in enzyme activity of only 30.9%.
In the above examples when enzyme is employed in ungranulated form or is granulated by means other than those described, improvement in retention of enzyme activity is also obtained when coarse particles of percompound in accordance with this invention are employed.
Further, in the above examples sodium perborate tetrahydrate when replaced by sodium perborate monohydrate as well as water-soluble alkali metal percarbonates, perphosphates and persulfates also improve retention of enzyme activity when the percompound has a particle size in accordance with this invention.
Further, activators for the percompounds may also be employed in the formulations of the above examples.
It will be apparent to those skilled in the art that variations and modifications of this invention can be made and that equivalents can be substituted therefor.
1. A biological cleaning composition consisting essentially of about 5-95% by weight of a water-soluble synthetic, organic surface-active agent selected from the group consisting of anionic, nonionic, ampholytic and amphoteric surface-active agents and mixtures thereof, about 0.1-10% by weight of a proteolytic enzyme effective in a pH range of about 412 and at temperatures above about 10 C. and about 5-30% by weight of a water-soluble inorganic percompound selected from the group consisting of alkali and alkaline earth metal perborates, percarbonates, perphosphates and persulfates, said percompound having a size such that at least about 50% of the particles thereof are retained on a screen having sieve openings of 0.42 mm. and less than about 5% of the particles pass through a screen having sieve openings of 0.177 mm.
2. The biological cleaning composition claimed in claim 1 wherein said enzyme is a proteolytic subtilisin enzyme.
3. The biological cleaning composition claimed in claim 1 wherein said percompound is sodium perborate.
4. The biological cleaning composition claimed in claim 1 wherein said percompound is substantially free of particles which pass through a screen having sieve openings of 0.177 mm.
5. The biological cleaning composition claimed in claim 1 wherein an activator of the percompound having the structural formula 0 Rt--OR wherein R is selected from the group consisting of lower alkyl and phenyl and R is an N-bonded imide radical is present in the composition in a mole ratio of available oxygen from the percompound to activator of about 1:1 to about 6:1.
6. The biological cleaning composition claimed in claim 1 wherein said enzyme is in a granule and is bound to sodium tripolyphosphate detergent builder salt.
7. The biological cleaning composition claimed in claim 3 wherein said sodium perborate is sodium perborate tetrahydrate.
References Cited UNITED STATES PATENTS 3,519,379 7/l970 Blomeyer et al. 252-99 X 3,637,339 1/ 1972 Gray 252-99 X 3,664,961 5/1972 Norris --252-99 MAYER WEINBLA'IT, Primary Examiner U.S. c1. X.R. 252Dig. 12