NZ208156A

NZ208156A - Built single-phase liquid detergent compositions containing stabilised enzymes

Info

Publication number: NZ208156A
Application number: NZ208156A
Authority: NZ
Inventors: J T Inamorato; M C Crossin
Original assignee: Colgate Palmolive Co
Priority date: 1983-05-31
Filing date: 1984-05-14
Publication date: 1986-11-12
Also published as: NO842163L; ATA178384A; NO160451B; DE3418294A1; IE841347L; SG44890G; AU558722B2; AU2831884A; PH19081A; GB2140819A; GB2140819B; GR82007B; NL8401740A; CA1220741A; MX162796A; MY102605A; GB8413673D0; HK67490A; PT78653A; IE58061B1

Description

<div class="application article clearfix" id="description"> New Zealand Paient Spedficaiion for Paient Number £08156 208i Priority Date(s): ?/■ ST *3 ;Complete Specification Filed: ;Class: r.<?.... Z'j.vi/oj.... ;Publication Date: ;if ^ NOV ;M ;P.O. Journal. No: ;NO DRAMUS' ;i.- ;A ;■y%0 $ ;Patents Form No. 5 ;Number ;PATENTS ACT 1953 ;Dated ;■,P ;COMPLETE SPECIFICATION £M0Affl ;BUILT SINGLE-PHASE LIQUID/DETERGENT COMPOSITION CONTAINING STABILIZED ENZYMES ;flfWe COLGATE-PALMOLIVE COMPANY, a corporation organised under the laws of the State of Delaware, United States of America of 300 Park Avenue, New York, New York 10022, United States of America do hereby declare the invention for which #we pray that a Patent may be granted to E0K/us, and the method by which it is to be performed, to be particularly described in and by the following statement: ;208156 ;This invention relates t.o slab.lo, liui.ll, rnzyme-contai n i nj; liquid dricr-gent compositions suitable for laundry or pre-soak formulations. Mote parliiu-larly, Lhe invention relaLes to aqueous enzyme-conLaiiiing liquid detergent compositions which contain a non-phosphate detergent builder and which are characterized by being physically stable, clear, si ng U—phase homogeneous .I i «ju Ld compositions. ;The formulation of stabilized enzyme-containing liquid detergent compositions has been the focus of much attention in the prior art. The desirability of incorporating enzymes into detergent compositions is primarily due to the effectiveness of proteolytic and amylolytic enzymes in decomposing pro-teinaceous and starchy materials found on soiled fabrics, thereby facilitating the removal of stains, such as, gravy stains, blood stains, chocolate slains and the like during laundering. However, enzymatic materials suitable ior laundry compositions, particularly proteolytic enzymes, are relatively expensive. Indeed, they generally are the most expensive ingredient in a typical commercial liquid detergent composition, even when present in relatively minor amounts. Moreover, enzymes are known to be unstable in aqueous compositions. It is for this reason that an excess of enzymes is generally required in liquid detergent formulations to compensate for the expected loss of enzyme activity during prolonged periods of storage. Accordingly, the prior art is replete with suggestions for stabilizing enzyme-containing liquid detergent compositions, and in particular unbuilt liquid compositions by the use of various materials which are incorporated into the composition and serve as enzyme stabilizers. ;In the case of liquid detergent compositions containing a builder, the problem of enzyme instability is particularly acute. I'r.imarily this is because detergent builders have a destabilizing effect on enzymes, even in compositions containing enzyme stabilizers which are otherwise effective in unbuilt formulations. Moreover, the incorporation of a builder into a liquid deLergent compo sition poses an additional problem, namely, Lhe ab.i.L.i.ly to form a stable single-phase solution, the solubility of sodium tripolyphosphate, for example, being relatively litni. Led .in aqu.eous compositions, and es|><v. ia I ly in the prescnte ol ;208156 ;anionic and nonionic detergents. Thus, for example, in U.K. ;Patent Application G.B. 2,079,305, published January 20, 1982, ;there is disclosed an aqueous built enzyme-containing liquid detergent composition which is stablized by a mixture of a polyol and boric acid and a cross-linked polyacrylate polymer. The compositions described in the examples, however, rather than being stable, clear, single-phase solutions, are instead turbid suspensions which are susceptible to product separation over prolonged periods of storage. Consequently, the problems of enzyme stability and p'hysical product stability remain as problems yet to be overcome in formulating a commercially acceptable built enzyme-containing liquid detergent composition. ;SUMMARY OF THE INVENTION The present invention provides a stabilized aqueous, built, ;clear, single-phase, enzyme-containing liquid detergent composition comprising: ;(a) from about 8 to 20%, by weight, of one or more surface active anionic detergent compounds; ;(b) from about 5 to 25%, by weight, of a water-soluble non-phosphate detergent builder salt; ;(c) an effective amount of an enzyme or enzyme mixture selected from the group consisting of alkaline protease enzymes and alpha-amylase enzymes; ;(d) an enzyme stabilizing system containing based on the weight of the detergent composition (i) from about 12 to 25% of propylene glycol and (ii) from about 1 to 5% of a boron compound selected from the group consisting of boric acid, ;boric oxide and alkali metal borates; and ;(e) from about 25 to 75%, by weight, water. ;It will particularly be noted that, in contrast to the compositions of the abovementioned UK patent application, the compositions of the present invention do not require the presence of a cross-linked polyacrylate polymer in the stabilizing system. ;In accordance with the process of the invention, laundering of stained and/or soiled materials is effected by contacting such materials with an aqueous solution of the above-defined liquid detergent composition. Unlike the built, enzyme-containing detergent compositions known in the art, the compositions of the present invention are characteristically clear, single-phase homogeneous ;"? n . ;X : ( 'rf solutions whicli are physicully sLab.le over prolonged periods oi sLorage and over a wide range (if 1 eitiperat ure. To avoid product separat ion. lhe present compositions are preferably substantially free of a phosphate builder salt. ;Unlike the enzyme-containing built liquid anionic detergent, compositions disclosed in the art, the anionic surfactant in the present compositions is solubili.zed in the presence of a builder salt. Moreover, the present enzyme-containing compositions arc characterized by the prcscncc of an enzyme-sLabi-lizing system which in addition to providing long-term stability to tin- enzyme over a wide range of temperatures, serves to enhance the solubility of the anionic surfactant and the non-phosphate builder in the aqueous composition allowing a physically stable single-phase solution to be formed for the particular range of compositions indicated. ;DETAILED DESCRIPTION OF T1IK INVENTION ;The enzyme stabilizing system of the invention is a mixture of propylene glycol and a boron compound selected from among boric acid, boric oxide and alkali metal borate capable of reacting with propylene glycol. The aiiiounL of propylene glycol is from about 12 to 25%, preferably from about 1:> to 20%, by weight, and the amount of the boron compound may vary from abouL I lo r)%, preferably from about 1 to 3%, by weight of the composition. ;The alkaline proteolytic enzymes suitable for the present compositions include the various commercial liquid enzyme preparations which have been adapted for use in detergent compositions, enzyme preparations in powdered form being also useful although, as a general rule, less convenient for incorporation into the built liquid detergent compositions. Thus, suitable liquid enzyme preparations include "Alcalase" and "Esperase" sold by Novo Industries, Copenhagen, Denmark, and "Maxatase" and "AZ-Protcasc" sold by Gist-Brocades, Delft, The Netherlands. Esperase is particularly preferred for the present composition because of its optimized activity at the higher pH values corresponding to built detergent compositions. ;Among the suitable ef-amylase .liquid enzyme preparations are those sold by Novo Industries and Gist-Brocades under the tradenames "Termamyl" and "Maxnmyl", respective]y. ;-A- ;208|56 ;The synthetic anionic detergent employed in the practice of the invention may bo any of a wide variety of such compounds which are well known and arc* described at length in the text Surface Active Agents, Vol. II, by Schwartz, 1'crry and Bcrch, published in 1958 by Jnterscicncc Publishers, lhe disclosures pertaining to such detergent being hereby incorporated by reference. The most preferred anionic detergent compounds are the higher (ID to 18 or 20 carbon atoms) alkyl benzene sulfonate salts wherein the alkyl group preferable contains 10 tc 15 carbon atoms, most preferably being a straight chain alkyl radical of 12 or 13 carbon atoms. Preferably, such an alkyl benzene sulfonate has a high content of 3- (or higher) phenyl isomers and a correspondingly low content (usually well below 50%) of 2- (or lower) phenyl isomers; in other words, the benzene ring is preferably attached in large part aL Lhe 13, 4, 5, 6 or 7 position of the alkyl group and the conLenl of isomers in which lhe benzene ring is attached at the 1 or 2 position is correspondingly low. Typical alkyl benzene sulfonate surface active agents are described in U.S Patent 3,320,174. Of course, more highly branched alkyl benzene sulfonates may also be employed but usually are not preferred, due to their lack of l> i odegrodetibiliIy. Other anionic detergents which are useful are the olefin sulfonate salts. Generally, these contain long chain alkenyl sulfonates or long chain hydroxy-alkane sulfonates (with the OH being on the carbon atom which is not directly attached to the carbon atom bearing the -SO^H group). The olefin sulfonate detergent usually comprises a mixture of such types of compounds in varying amounts, often together with long chain disulfonates or sulfate-sulfonates. Such olefin sulfonates are described in patents, such as U.S. Patent Nos. 2,061,618; 3,409,637; 3,332,880; 3,420,875; 3,428,654; 3,506,580; and British Patent No. 1,129,158. The number of carbon atoms in the olefin sulfonate is usually within Lhe range of 10 to 25, more commonly 10 to 18 or 20, e.g., a mixture principally of and having an average of about 14 carbon atoms, or a mixture principally of Cj^, Cjg and C^g having an average of about 16 carbon atoms. 208153 Another class of useful anionic detergents is that of the higher paraffin sulfonates. These may be primary paraffin sulfonates made by reacting long chain alpha-olefins and bisulfites, e.g., sodium bisulfite, or paraffin sulfonates having the sulfonate groups distributed along the paraffin chain, such as the products made by reacting a long chain paraffin with sulfur dioxide and oxygen under ultraviolet light, followed by neutralization with sodium hydroxide or other suitable base (as in U.S. Patents 2,503,280; 2,507,088; 3,260,741; and 3,372, 188). The paraffin sulfonates preferably con tain from 13 to 17 carbon atoms and will normally be the monosiilfonato but if desired, may be di-f tri- or higher sulfonates. Typically, the di- and poly-sulfonates will be employed in admixture with a corresponding monosulfonate, for example, as a mixture of mono- and disulfonates containing up to about 30% of the disulfonate. The hydrocarbon substiluent l.herc»or is pre Tim nbl y linear but if desired, branched chain paraffin sulfonates can be employed, although they are inferior with respect to biodegradnbi1ity. Other suitable anionic detergents are sulfated ethoxylatud higher fatty alcohols of the formula R0(0211^0)^802^1, wherein R is a fuLLy nlky.1 of from 10 to 18 or 20 carbon atoms, m is from 2 to 6 or 8 (preferably having a value i'rom about 1/5 to 1/2 the number of carbon atoms in R) and M is a solubiljzing salt-forming cation, such as an alkali metal, ammonium, lower alkylamino or lower alkanolamino, or a higher alkyl benzene sulfonate wherein the higher alkyl is of 10 to 15 carbon atoms. Ethylene oxide is the preferred lower alkylcne oxide of the anionic al-koxylate detergent, and the proportion thereof in the polyethoxylated higher alkanol sulfate is preferably 2 to 5 moles of ethylene oxide groups present per mole of anionic detergent, with three moles being most preferred, especially when the higher alkanol is of 11 or 12 to 15 carbon aLoms. To maintain Lhe desired hydrophile-lipophile balance, when the carbon atom content of the alkyl chain is in Lhe lower porLion of Lhe 10 to 18 carbon atom range, Lhe ethylene oxide content of the detergent may be reduced to about two moles per moLe whereas 2OS f56 when the higher alkanol is of 16 to 18 carbon atoms in Lhe higher part: of the range, the number of eLhylene oxide groups may be increased l.o A or 3 and in some cases to as high as 8 or 9. Similarly, the salt-forming cation may be altered to obtain the best solubility. It may be any suitably solubiiizing metal or radical but will most frequently be alkali metal, e.g., sodium, or ammonium. If lower alkylamine or a]kanolamine groups arc uLiJi/.ed the a Iky Is and alkanols will usually contain from 1 to 4 carbon atoms and the amines and alkanolamines may be mono-, di- and tri-substituted, as in mcnethanolamine, diisopropanolatnine and t.rimethylamine. The poly-lower alkoxy higher alkanol sulfates may be employed in combination with other preferred anionic detergents such as the higher alkyl benzene sulfonates to provide optimum detergency in the present built liquid deLergenL compositions. A preferred polyethoxylaLed alcohol sulfate detergenL is available from Shell Chemical Company and is marketed as Neodol 25-3S. Examples of the higher alcohol polyethenoxy sulfates which may be employed in the liquid detergent compositions of the invention include: mixed C^ ^ normal or primary alkyl triethenoxy sulfate, sodium salt; myristyl trieLhcnoxy sulfate, potassium salt; n-decyl diethenoxy sulfate, diethanolamine salt; lauryl diethenoxy sulfate, ammonium salt; palmityl tetraethenoxy sulfate, sodium salt; mixed normal primary alkyl mixed tri- and tetra-ethenoxy sulfate, sodjum salt; stearyl pentaethenoxy sulfate, trimethylamine salt; and mixed C,n 1tJ 1U—lo normal primary alkyl triethenoxy sulfate, potassium salt. Other useful anionic detergents include the higher acyl sarcosinates, e.g., sodium N-lauroyl sarcosinate; higher fatty alcohol sulfates, such as sodium lauryl sulfate and sodium tallow alcohol sulfate; sulfated oils; sulfates of mono- or diglycerides of higher fatty acids, e.g., stearic inonoglyceride monosuI IaLc; although, of those, the sodium higher alcohol sullatcs have been found to be inferior to the polyethoxylated sulfates in detergency; aromatic poly(lower alkenoxy) ether sulfates, such as Lhe sulfates of the condensation producLs of eLhylene oxide and nonylphenol (usually having 1 Lo 20 oxyel.hyLene -7- -7- 208?56 groups per molecule, preferably 2 Lo 12); polyethoxy higher ajcohol. sulfates and alkyl phenol polyethoxy sulfates having a lower aJkoxy (of ] to 4 carbon atoms, e.g., methoxy) substituent on a carbon close to that carrying the sulfate group, such as monomethyl ether monosulfate of a long chain vicinal glycol, e.g., mixture of vicinal alkane diols of 16 to 20 carbon atoms in a straight chain; acyl esters of isethionic acid, e.g., oleyl isethionates; acyl N-methyl taurides, e.g., potassium N-methyl lauroyl or oleyl taurides; higher nlkyi phenyl polyeLhoxy sulfonates; higher ulkyi phenyl polyethoxy sulfonates; higher alkyl phenyl disulfonates, e.g., pentadecyl phenyl disulLonate; and higher fatty acid soaps, e.g., mixed coconut oil and tallow soaps in a 1:4 rat io. Among the aforementioned types of anionic detergents, Lhe sulfates and sulfonates are generally preferred but. Lhe corresponding organic plio.spli.it r:; and phosphonates may also be employed when their contents of pliosphoui:; are not objectionable. Generally, the water soluble anionic synthetic organic detergents, (including soaps), are salts of alkali metal cations, such as potassium, lithium, and especially sodium, although salts of ammonium and substituted ammonium cations, such as those previously described, e.g., triethanol-aminc, triisopropylami no, may also be used. A nonionic detergent may optionally be employed in minor amounts Lo supplement the anionic detergent compound in the present built liquid detergent compositions. When used in such combination with an anionic detergenL, Lhe amount of nonionic detergent will generally be below about 10%, and preferably below about 5%, by weight, of the total composition. The nonionic detergents are usually poly-lower alkoxylated lipophiles wherein the desired hydrophile-lipophile balance is obtained from addition of a hydrophilic poly-lower alkoxy group to a lipophilic moieLy. For the present compositions the nonionic detergent employed is preferably a poly-lower alkoxylated higher alkanol wherein the alkanol is of 10 to 18 carbon atoms and wherein the number of moles of lower alkylene oxide (of 2 or 3 carbon atoms) is from 3 208156 to 12. Of such materials it is preferred to employ those wherein the higher alkanol is a higher fatty alcohol of 11 or 12 to 15 carbon atoms and which contain from 5 to 8 or 5 to 9 lower alkoxy groups per mole. Preferably, the lower alkoxy is ethoxy but in some instances it may be desirably mixed with propoxy, the latter, if present, usually being a minor (less than 50%) constituent. Exemplary of such compounds are those wherein the alkanol is of 12 to 15 carbon (R) atoms and which contain about 7 ethylene oxide groups per mole, e.g., Neodol 25-7 and Neodol 23-6.5, which products are made by Shell Chemical Company, Inc. The former is a condensation product of a mixture of higher faLty alcohols averaging about 12 to 15 carbon atoms, with about 7 moles of eLhylene oxide and the latter is a corresponding mixture wherein the carbon atoms content of the higher fatty alcohol is 12 to 13 and the number of ethylene oxide groups per mole averages about 6.5. The higher alcohols are primary alkanols. OlIkt ex- © amples of such detergents include Tergitol 15-S-7 and Tergitol 15-S-9, both of which are linear secondary alcohol ethoxylates made by Union Carbide Corporation. The former is a mixed ethoxylation product of an 11 to 15 carbon atom linear secondary alkanol with seven moles of ethylene oxide and the latter is a similar product but with nine moles of ethylene oxide being reacted. Also useful in the present compositions are higher molecular weight non-ionics, such as Neodol 45-11, which are similar ethylene oxide condensation products of higher fatty alcohols, with the higher faLty alcohol being of 14 to 15 carbon atoms and the number of ethylene oxide groups per mole being about 11. Such products are also made by Shell Chemical Company. Other useful non-ionics are represented by Plurafac B-26 (BASF Chemical Company), the reaction product of a higher linear alcohol and a mixture of eLhylene and propylene oxides. In the preferred poly-lower alkoxylated higher alkanols, Lhe best balance of hydrophilic and lipophilic moieties are obtained when Lhe number of lower alkoxies are from about 40% to 100% of the number of carbon atoms in the higher alcohol, preferably 40 to 60% thereof. The nonionic detergent is preferably comprised of at least 50% of the preferred ethoxylated alkanols. Higher molecular 208 f 56 weight alkanols and various other normally solid nonionic detergent compounds and surfactants may contribute to gelation of the liquid detergent composition and consequently, are normally omitted or limited in quantity in the present compositions, although minor proportions thereof may be employed for their cleaning properties, etc. With respect to both preferred and less preferred nonionic detergents, the alkyl groups present therein are preferably linear although a minor degree of slight branching may be tolerated, such as at a carbon next to or two carbons removed from the terminal carbon of the straighL chain and away from the ethoxy chain with the proviso thnL such branched alkyl is no more than three carbons in length. Normally the proportion of carbon atoms in such a branched configuration will be minor, rarely exceeding 20% of the total carbon atom content of the alkyl. Similarly, although linear alkyls which are terminally joined to the ethylene oxide chains arc hij>liiy preferred and are considered to result in the optimum combination of detergency, biodegradability and non-gelling characteristics, medial or secondary .joinder to the ethylene oxide in the chain may occur. In such instance, it is usually in only a minor proportion of such alkyls, generally less than 20% but as is in the case of the aforementioned Tergitols, may be greaLer. Also, when propylene oxide is present in the lower alkylene oxide chain, it will usually be less than 20% thereof and preferably less than 10% thereof. The non-phosphate detergent builder salts are employed in the present compositions in amounts generally of from about 5 to 25%, and preferably from about 10 to 20%, by weight. Specific examples of non-phosphorous water-soluble inorganic builders include water-soluble inorganic carbonate, bicarbonate and silicate salts. The alkali metal, for example, sodium and potassium, carbonates, bicarbonates and silicates are particularly useful herein. Water-soluble organic builders are also useful und include the alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycar-boxylates and polyhydroxysulfonates. Specific examples of polyacetate and 208 156 polycarboxylate builders include sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylene diaminetetracetic acid, niLrilotriacetic acid, benzene polycarboxylic (i.e. penta- and tetra-) acids, carboxymethoxy-succinic acid and citric acid. The percentage of water, the main solvent in the present compositions, will usually be from about 25 to 75%, preferably 40 Lo 60%, by weighl, of the liquid composition. The optical fluorescent brighteners or whiteners employed in the liquid detergent compositions are important constituents of modern detergent compositions which give washed laundry and materials a bright appearance so that the laundry is not only clean but also appears clean. Although it is possible to utilize a single brightener for a specific intended purpose in the present liquid detergent compositions it is generally desirable to employ mixtures of brighteners which will have good brightening effects on cotton, nylons, polyesters and blends of such materials and which are also bleach stable. A good description of such types of optical brighteners is given in the article "The Requirements of Present Day Detergent Fluorescent Whitening Agents" by A. E. Siegrist, J. Am. Oil Chemists Soc., January 1978 (Vol. 55). That article and U.S. Patent 3,812,041, issued May 21, 1974, both of which are hereby incorporated by reference contain detailed descriptions of a wide variety of suitable optical brighteners. Among the brighteners that are useful in the present liquid detergent compositions are: Calcofluor 5BM (American Cyanamid); Calcofluor White ALF (American Cyanamid); SOF A-2001 (Ciba); CDW (Hilton-Davis); Phorwite RKH, Phor-wite BBH and Phorwite BHC (Verona); CSL, powder, acid (American Cyanamid); FB 766 (Verona); Blancophor PD (GAF); UNPA (Geigy); Tinopal RBS 200 (Geigy). Adjuvants may be present in the liquid detergent compositions to provide -11- 20815k additional properties, either functional or aesthetic. Included among the useful adjuvants are soil suspending or antiredoposition agents, such as polyvinyl alcohol, sodium carboxymethyl cellulose, hydroxypropylmethyl cellulose; thickeners, e.g., gums, alginates, agar agar; foam improvers, e.g., Inuric myristic diethanolamide; foam destroyers, e.g., silicones; bactericides, e.g., tri-bromosalicylanilide, hexachlorophene; dyes; pigments (waLcr dispersiblc); preservatives; ultraviolet absorbers; fabric softeners; opacifying agents, e.g., polystyrene suspensions; and perfumes. Of course, such materials will be selected based on the properties desired in the finished product, their compatibility with the other constituents, and their solubility in the liquid composition. The present liquid compositions are efficient and easy Lo use. Compared to heavy duty laundry detergent powders, much smaller volumes of the present liquids are employed Lo obtain comparable cleaning oi soiled laundry. For example, using a typical preferred formulation of this invention, only abouL 132 grams or 1/2 cup of liquid is needed for a full tub of wash in a Lop-loading automatic washing machine in which the water volume is 15 to 18 gallons (55 to 75 liters); and even less is needed for front-loading machines. Thus, the concentration of the liquid detergent composition in the wash water is on the order of about 0.2%. Usually, Lhe proportion of the liquid coniposiLjon in Lhe wash solution will range from about 0.05 to 0.3%, preferably from 0.15 to 0.25% The proportions of the various consLiLuenLs ol." Lhe liquid compos i L i on may vaiy accordingly. Equivalent results can be obtained by using greater proportions of a more dilute formulation but the greater quanLiLy needed will require additional packaging and will generally be less convenient for consumer use. 2 08156 exam!'lis 1 Enzyme-containing built liquid detergent compositions A-E were formulated as set forth below in Table 1. The percentages shown indicate weight percent. Table 1 Sodium dodecylbenzene sulfonate Ethoxylated Cj2~^15 alc°h°l sulfate (3 mole EO/mole alcohol Brightener Sodium Nitriliotriacetate PBB(2^ Perfume Protease enzyme (3) Propylene glycol Borax A 7% 0.2 15 0.3 B 7% 15 20 c 7% 0.2 0.2 15 20 d 1% 15 20 E 7% 0.2 0.2 15 0.3 0.3 0.3 0.3 20 h2o Percent active enzyme after (a) k days at 110°F (b) 6 days at 110°F 15 -balance- 61 86 98% 88 (1) Neodol 25-3S sold by Shell Oil Company. (2) Polar Brilliant Blue - a 1% active dye solution. (3) "Esperase" sold by Novo Industries containing 5% enzyme, 75% propylene glycol, and balance 1^0 having an activity of 8.0 KNPU/gm. (Kilo Novo Protease units/gm). 208156 The enzyme activities of compositions A-E were tested after b days storage at 110°F, the percent activity relative to the initial value being indicated in Table 1. The activity after 4 days was measured only for composition Li. Compositions A and B were the only compositions which d.id noL contain an enzyme sLabiliz ing system in accordance with the invention, and manifested a total (composition or near total (composition B) loss of enzyme activity after 6 days. Compositions C, D and E reflect the marked improvement of enzyme stability attendant to the inclusion of propylene glycol and borax in the detergent composition. Compositions B through E were all clear, single-phase, homogeneous solutions which maintained their physical stability and clarity after 6 months of storage at both room temperature and at 110°F. Composition A which was noL in accordance with the invention was physically unstable due to the absence of propylene glycol which in addition to serving as an enzyme stabilizer (in conjunction with the aforementioned boron compound) promotes the solubility of the anionic detergents and the NTA builder in the aqueous composition. 208156 EXAMPLE 2 Enzymc-conLaining built liquid delergcnL compositions I' and (! were formulated essentially similar to compositions A-E except that sodium citrate was used as the builder salt instead of sodium NTA. The compositions are shown below in Table 2. Table 2 Sodium dodecyl benzene sulfonate Ethoxylated alcohol sulfate (3 moles EO/mole alcohol) Brightener Sodium citrate PBB(1) Perfume Protease enzyme (2) Propylene glycol Borax h2o F 7% 7 0.2 12 1 0.3 1 20 -balancc- g 7% 7 0.2 12 1 0.3 1 20 2 Percent active enzyme after 4 days at 110°F 20 95 (1) Polar Brilliant Blue - a 1% active dye solution. (2) "Esperase" sold by Novo Industries containing 5% enzyme, 75% propylene glycol, and balance 1^0 having an activity of 8.0 KNPU/gm. (Kilo Novo Protease units/gm). 2GS 15 Composition G in accordance with the invention manifested an enzyme activity after four days of 95% as compared to composition F which contained no boron compound and consequently lost more than 3/4 of its initial enzyme activity. Both compositions were clear single-phase solutions which remained physically stable after six months of storage at both room temperature and 110°F. 208f 5 example 9, Enzyme-containing builL liquid deLergenL composiLions II, 1 and J were formulated essentially similar lo compos i L i ons I1' and (J in Example 2 except llial I liey contained a mixture ol proLease and alpha-amyLase enzymes insLead uL a single proLea.se enzyme. The compositions arc shown below in Tabic 3. Table 3 Sodium dodecyl benzene sulfonate Ethoxylated alcohol sulfate (3 moles EO/mole alcohol) Brightener Sodium citrate PBB(1) Perfume (2) Protease enzyme e»£-Amylase enzyme Propylene glycol Borax h2o (3) Percent active enzyme after 4 days at 110°F o^-amylase enzyme ProLease enzyme 7% 0.2 12 0.3 0.4 20 50% 30 1 7% 0.2 12 0.3 0.4 20 67% 73 j 7% 0.2 12 0.3 0.4 20 1 . 3 -balance-: 87% 94 (1) Polar Brilliant Blue - a 1% active dye solution. (2) "Esperase" sold by Novo Industries containing 5% enzyme, 75% propylene glycol, and balance li20 having an activity of 8.0 KNPU/gm. (Kilo Novo Protease units/gm). (3) "Termamyl" sold by Novo Industries containing 5% enzyme, 18% Nacl and balance </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 20815 6 Compositions I and J in accordance with the invention demonstrated a markedly more stable enzyme activity after four days for both the protenso and amylase enzymes relative to composition H which contained no boron compound and consequently lost about 1/2 of its initial amylolytic activity and about 1/3 of its initial proteolytic activity during the period of four days. All three compositions were clear single-phase solutions which remained physically stable after six months of storage. # 308156 WHAT WE CLAIM IS;

1. A stabilized aqueous, built, clear, single-phase, enzyme-containing liquid detergent composition comprising: (a) from 8 to 20%, by weight, of one or more surface active anionic detergent compounds; (b) from 5 to 25%, by weight, of a water-soluble non-phosphate detergent builder salt; (c) an effective amount of an enzyme or enzyme mixture selected from the group consisting of alkaline protease enzymes and alpha-amylase enzymes; (d) an enzyme stabilizing system containing, based on the weight of the detergent composition, (i) from 12 to 25% of propylene glycol and (ii) from 1 to 5% of a boron compound selected from the group consisting of boric acid, boric oxide and alkali metal borates; and (e) from 25 to 75%, by weight, water.

2. A detergent composition according to claim 1 wherein said builder salt is sodium citrate.

3. A detergent composition according to claim 1 wherein said builder salt is sodium nitrilotriacetate.

4. A detergent composition according to any one of the preceding claims, which is substantially free of a phosphate detergent builder salt.

5. A detergent composition according to any one of the preceding claims, which is substantially free of cross-linked polyacrylate polymers.

6. A detergent composition according to any one of the preceding claims in which the composition contains from 15 to 20%, by weight, of said propylene glycol and -19- 208156 from 1 to 3%, by weight, of said boron compound.

7. A detergent composition in accordance with any one of the preceding claims wherein said boron compound is borax.

8. A detergent composition in accordance with any one of the preceding claims wherein said builder salt is present in an amount of from 10 to* 20%, by weight.

9. A detergent composition according to any one of the preceding claims wherein the anionic detergent is a mixture of a CiQ~Ci8 alkyl benzene sulfonate salt and a polyethoxylated Ciq-Cis alcohol sulfate salt.

10. A stabilized liquid detergent composition substantially as herein described with reference to the Examples.

11. A method of laundering comprising contacting the stained and/or soiled fabrics to be laundered with an enzyme-containing, built, clear, single-phase liquid detergent composition comprising: (a) from 8 to 20%, by weight, of one or more surface active anionic detergent compounds; (b) from 5 to 25%, by weight, of a water-soluble non-phosphate detergent builder salt; (c) an effective amount of an enzyme or enzyme mixture selected from the group consisting of alkaline protease enzymes and alpha-amylase enzymes; (d) an enzyme stabilizing system containing, based on the weight of the detergent composition (i) from 12 to 25% of propylene glycol and (ii) from 1 to 5% of a boron compound selected from the group consisting of boric acid, boric oxide and alkali metal borates; and (e) from 25 to 75%, by weight, water.

12. A method according to claim 11 wherein said builder salt is sodium citrate.

13. A method according to claim 11 wherein said builder salt is sodium nitrilotriacetate.

14. A method according to any one of claims 11 to 13 wherein said detergent composition is substantially free of a phosphate detergent builder salt.

15. A method according to any one of claims 11 to 14 wherein said detergent composition is substantially free of cross-linked polyacrylate polymers.

16. A method according to any one of claims 11 to 15 wherein the composition contains i:rom 15 to 20%, by weight, of said propylene glycol and from 1 to 3%, by weight, of borax as said boron compound.

17. A method according to any one of claims 11 to 16 wherein said detergent composition contains from 10 to 20% of a non-phosphate builder salt.

18. A method according to any one of claims 11 to 17 wherein said detergent composition contains a mixture of a Ciq-c18 alkyl benzene sulfonate salt and a polyethoxylated Cio~Cig alcohol sulfate salt.

19. A method of laundering substantially as herein described with reference to the Examples. WEST-WALKLR, McCABt -21- </div>