WO2000046333A1

WO2000046333A1 - Liquid dishwashing detergent compositions containing amylase enzymes

Info

Publication number: WO2000046333A1
Application number: PCT/US2000/003227
Authority: WO
Inventors: Peter Robert Foley; Bruce Prentiss Murch
Original assignee: The Procter & Gamble Company
Priority date: 1999-02-08
Filing date: 2000-02-08
Publication date: 2000-08-10
Also published as: EP1151070A1; KR20010089638A; AR017744A1; CN1345364A; JP2002536497A; AU2874600A; EP1151075A1; AU2874300A; BR0008066A; JP4107633B2; AU2874400A; CA2360654A1; JP2002536499A; JP2002536498A; WO2000046335A1; EP1151074A1; JP2002536500A; WO2000046331A1; TR200102231T2; CZ20012872A3

Abstract

Liquid dishwashing detergent composition containing one or more amylase enzymes and a suds booster which exhibits excellent greasy soil removal performance and are either of a high pH of greater than about 8.

Description

LIQLTD DISHWASHING DETERGENT COMPOSITIONS CONTAINING AMYLASE ENZYMES

TECHNICAL FIELD

The present invention relates to liquid dishwashing detergent compositions containing amylase enzymes and which exhibit excellent greasy soil removal performance and having a high pH of greater than about 8. BACKGROUND OF THE INVENTION

Light-duty liquid (LDL) or gel detergent compositions useful for manual dishwashing are well known in the art. Such products are generally formulated to provide a number of widely diverse performance and aesthetics properties and characteristics. First and foremost, liquid or gel dishwashing products must be formulated with types and amounts of surfactants and other cleaning adjuvants that will provide acceptable solubihzation and removal of food soils, especially grease, fat and other hydrophobic soils, from dishware being cleaned with aqueous solutions of these dishwashing products.

Heavily soiled dishware can present special problems duπng manual dishwashing operations. Kitchen articles such as plates, utensils, pots, pans, crockery and the like may be heavily soiled m the sense that relatively large amounts of food soils and residues, particularly polymerized and burnt-on greasy soils, may still be found on the dishware at the time such soiled dishware is to be manually washed. Such soil residues may be tenaciously adhered or stuck to the surfaces of the dishware to be cleaned as the result of the food soils present, the nature of the dishware surfaces involved or even the type of cooking operations to which the soiled dishware had been subjected. Starch-based soils are particularly prone to become tenaciously adhered to the side of kitchenware Thus, there is a continuing effort by formulators of liquid dishwashing compositions to incorporate additional components into LDL detergents to provide consumers with improved cleaning benefits, particularly on the difficult, baked and burnt-on soils which make cleaning kitchenware laboπous. One such component which can improve cleaning performance on tenacious soils is amylase enzymes. As a component of a liquid dishwashing detergent, amylase enzymes can be extremely effective at removing starch-based soils and residues adhered to kitchen articles such as cookware and dishware. But while amylase enzymes provide excellent cleaning benefits, it has been difficult to successfully incorporate amylases into a liquid dish ashing detergent formulation because the enzymes tend to be unstable and rapidly degrade, leaving the formulation's amylase enzyme constant at levels far too low to provide adequate cleaning benefits Thus upon prolonged storage, the formulation's starch-cleanmg performance will gradually deteriorate as the amylase enzymes degrade to levels insufficient to provide starch-cleaning benefits

Given the foregoing, there is a continuing need to formulate manual dishwashing compositions that have improved amylase enzyme stability Accordingly, it is a benefit of the present invention to provide liquid dishwashing compositions that have excellent amylase enzyme stability and thus provide excellent cleaning benefits even after prolonged storage.

SUMMARY OF THE INVENTION It has now been determined in the present invention that improved cleaning performance may be obtained when the amylase enzyme is added to a liquid dishwashing detergent composition having a relatively alkaline pH of at least 8, preferably at least 9. This improved cleaning performance is obtained whether or not the amylase enzyme-destabilizing compounds discussed above are excluded or kept to very low levels.

Thus the present invention relates to a liquid dishwashing detergent composition comprising: (a) from about 0.0001% to about 5%, of an amylase enzyme; and (b) at least about 0.5% of a suds booster; wherein the composition has a pH of greater than about 8, preferably greater than about 9 and the detergent composition has especially desirable greasy soil removal performance when used to clean heavily soiled kitchen articles.

All parts, percentages and ratios used herein are expressed as percent weight unless otherwise specified. All documents cited are, in relevant part, incorporated herein by reference. Unless otherwise noted all pH values reported for a composition are as measured as 10% aqueous solution.

DETAILED DESCRIPTION OF THE INVENTION Definitions - As used herein the term "light duty liquid detergent composition" (LDL) refers to those compositions which are employed in manual (i.e. hand) dishwashing.

By "kitchen articles" it is meant cookware, flatware, dishware, silverware and other articles commonly found in the kitchen and used for the preparation, consumption and serving of food as well as those articles used for cleaning up at the conclusion of a meal or other food preparation. ENZYMES Detergent compositions of the present invention comprise at least one amylase enzyme and (if desirable) other enzymes which provide cleaning performance benefits.

Amylase - Amylases (α and/or β) can be included for removal of carbohydrate-based stains. Suitable amylases are Termamyl® (Novo Nordisk), Fungamyl® and BAN® (Novo Nordisk). The enzymes may be of any suitable origin, such as vegetable, animal, bacterial, fungal and yeast origin. Amylase enzymes are normally incorporated in the detergent composition at levels from about 0.0001% to about 2%, preferably from about 0 0001% to about 0.5%, more preferably from about 0.0005% to about 0.1%.

In one embodiment of the present invention, amylase enzymes are used at very low levels- from about 0 0001 % to about 0.05%, preferably from about 0 0002% to about 0.02% Based on experience with other enzyme species, it would seem that the use of such small amounts of amylase enzymes would not enhance cleaning efficacy; but it has been determined m the present invention that appreciable cleaning benefits are obtained even at these low levels.

When enzymes are used m a liquid dishwashing composition, at very low levels, m order to prevent such small amounts of enzyme from becoming quickly destabilized and destroyed it is preferable that certain enzyme destabilizing ingredients (discussed m greater detail below) are excluded from the liquid dishwashing composition.

Amylase enzymes also include those described in W095/26397 and m co-pending application by Novo Nordisk PCT/DK96/00056. Other specific amylase enzymes for use m the detergent compositions of the present invention therefore include :

(a) α-amylases characteπsed by having a specific activity at least 25% higher than the specific activity of Termamyl® at a temperature range of 25°C to 55°C and at a pH value in the range of 8 to 10, measured by the Phadebas® α-amylase activity assay. Such Phadebas® α-amylase activity assay is descπbed at pages 9-10, W095/26397. (b) α-amylases according (a) comprising the ammo sequence shown m the SEQ ID listings m the above cited reference, or an α-amylase being at least 80% homologous with the ammo acid sequence shown in the SEQ ID listing.

(c) α-amylases according (a) obtained from an alkalophihc Bacillus species, compnsing the following ammo sequence in the N-termmal . His-His-Asn-Gly-Thr-Asn-Gly-Thr-Met-Met-Gln- Tyr-Phe-Glu-Trp-Tyr-Leu-Pro-Asn-Asp.

A polypeptide is considered to be X% homologous to the parent amylase if a comparison of the respective ammo acid sequences, performed via algorithms, such as the one descπbed by

Lipman and Pearson Science 227, 1985, p. 1435, reveals an identity of X% (d) α-amylases according (a-c) wherein the α-amylase is obtainable from an alkalophihc Bacillus species, and in particular, from any of the strains NCEB 12289, NCIB 12512, NCD3 12513 and DSM 935

In the context of the present invention, the term "obtainable from" is intended not only to indicate an amylase produced by a Bacillus strain but also an amylase encoded by a DNA sequence isolated from such a Bacillus strain and produced in an host organism transformed w ith said DNA sequence.

(e)α-amylase showing positive lmmunological cross-reactivity with antibodies raised against an α-amylase having an amino acid sequence corresponding respectively to those α-amylases m (a- d).

(f) Variants of the following parent α-amylases which (I) have one of the ammo acid sequences shown in corresponding respectively to those α-amylases in (a-e), or (π) displays at least 80% homology with one or more of said amino acid sequences, and/or displays lmmunological cross- reactivity with an antibody raised against an α-amylase having one of said amino acid sequences, and/or is encoded by a DNA sequence which hybridizes with the same probe as a DNA sequence encoding an α-amylase having one of said amino acid sequence; in which vaπants :

1. at least one amino acid residue of said parent α-amylase has been deleted; and/or

2. at least one ammo acid residue of said parent α-amylase has been replaced by a different ammo acid residue; and/or 3. at least one ammo acid residue has been inserted relative to said parent α-amylase; said variant having an α-amylase activity and exhibiting at least one of the following properties relative to said parent α-amylase : increased thermostabihty, increased stability towards oxidation, reduced Ca ion dependency, increased stability and/or α- amylolytic activity at neutral to relatively high pH values, increased α-amylolytic activity at relatively high temperature and increase or decrease of the isoelectric point (pi) so as to better match the pi value for α-amylase variant to the pH of the medium. Said vaπants are descπbed in the patent application PCT/DK96/00056.

Other amylases suitable herein include, for example, α-amylases descπbed in GB 1,296,839 to Novo; RAPID ASE®, International Bio-Synthetics, Inc. and TERMAMYL®. Novo FUNGAMYL® from Novo is especially useful. Engineering of enzymes for improved stability, e.g., oxidative stability, is known. See, for example J. Biological Chem., Vol. 260, No. 11, June 1985, pp. 6518-6521. Certain preferred embodiments of the present compositions can make use of amylases having improved stability m detergents such as automatic dishwashing types. especially improved oxidative stability as measured against a reference-point of TERMAMYL® m commercial use in 1993 These preferred amylases herein share the characteristic of being "stability-enhanced" amylases, characterized, at a minimum, by a measurable improvement in one or more of oxidative stability, e g , to hydrogen peroxide/tetraacetylethylenediamine in buffered solution at pH 9-10, thermal stability, e.g , at common wash temperatures such as about 60°C, or alkaline stability, e.g., at a pH from about 8 to about 1 1, measured versus the above-identified reference-point amylase. Stability can be measured using any of the art-disclosed technical tests See, for example, references disclosed in WO 9402597 Stability-enhanced amylases can be obtained from Novo or from Genencor International One class of highly preferred amylases herein have the commonality of being derived using site-directed mutagenesis from one or more of the Bacillus amylases, especially the Bacillus α-amylases, regardless of whether one, two or multiple amylase strains are the immediate precursors Oxidative stability-enhanced amylases vs. the above-identified reference amylase are preferred for use, especially in bleaching, more preferably oxygen bleaching, as distinct from chlorine bleaching, detergent compositions herein. Such preferred amylases include (a) an amylase according to the hereinbefore incorporated WO 9402597, Novo, Feb. 3, 1994, as further illustrated by a mutant in which substitution is made, using alamne or threonme, preferably threonine, of the methiomne residue located in position 197 of the B. licheniformis alpha-amylase, known as TERMAMYL®, or the homologous position variation of a similar parent amylase, such as B. amylohquefaciens, B. subtihs, or B. stearothermophilus; (b) stability-enhanced amylases as descπbed by Genencor International in a paper entitled "Oxidatively Resistant alpha-Amylases" presented at the 207th American Chemical Society National Meeting, March 13-17 1994, by C. Mitchinson. Therein it was noted that bleaches in automatic dishwashing detergents inactivate alpha-amylases but that improved oxidative stability amylases have been made by Genencor from B. licheniformis NCD38061. Methiomne (Met) was identified as the most likely residue to be modified. Met was substituted, one at a time, in positions 8, 15, 197, 256, 304, 366 and 438 leading to specific mutants, particularly important being M197L and M197T with the M197T variant being the most stable expressed variant. Stability was measured in CASCADE® and SUNLIGHT®; (c) particularly preferred amylases herein include amylase vaπants having additional modification in the immediate parent as descπbed in WO 9510603 A and are available from the assignee, Novo, as DURAMYL®. Other particularly preferred oxidative stability enhanced amylase include those described in WO 9418314 to Genencor International and WO 9402597 to Novo Any other oxidative stability-enhanced amylase can be used, for example as deπved by site-directed mutagenesis from known chimeπc, hybrid or simple mutant parent forms of available amylases. Other preferred enzyme modifications are accessible See WO 9509909 A to Novo.

Other Enzymes - Although amylase enzymes provide excellent cleaning benefits when included in a detergent composition, it is preferred that they be used as one part of a cocktail of conventional applicable enzymes like protease, amylase, hpase, cutinase and/or cellulase.

Enzymes when present in the compositions, at from about 0 0001% to about 5% of active enzyme by weight of the detergent composition Other enzymes suitable for use in the present invention include cellulases, hemicellulases, peroxidases, proteases, hpases, cutinases, pectinases, xylanases, reductases, oxidases, phenoloxidases. hpoxygenases, hgninases, pullulanases, tannases, pentosanases, malanases, β-glucanases, arabinosidases or mixtures thereof. Preferred proteolytic enzymes, then, are selected from the group consisting of Alcalase ® (Novo Industπ A/S), BPN', Protease A and Protease B (Genencor), and mixtures thereof Protease B is most preferred.

Further non-limiting examples of suitable and preferred enzymes are disclosed in U. S. Pat. No. 5,990,065, to Vmson et al, issued Nov. 23, 1999, which is hereby incorporated by reference. COMPOSITION pH

As measured as 10% aqueous solution, the compositions of the present invention will have a pH of at least about 8, preferably at least about 9, more preferably at least about 9.5. Preferably the pH of the present detergent compositions will be less than about 12, more preferably less than about 1 1. Amylase enzymes are especially effective as part of a high pH detergent composition. Without intending to be limited by theory it is believed that the increased efficacy of amylases at high pH is because amylase enzymes are effective only against hydrated soils and the increased alkalinity of the detergent composition increases the hydration of the tenacious, baked-on starch soils thereby increasing the catalysis of starch hydrolysis. Furthermore, high pH detergent compositions improves overall dish cleaning performance, regardless of the presence of amylase enzymes, because the higher pH environment increases elimination of soil mateπals by hydrolysis Those hydrolyzed soils which are not completely eliminated are typically loosened and softened to such a degree that amylase enzymes, as well as other cleaning adjuvants, can more readily work to eliminate them.

The benefits of a more alkaline detergent composition to enhance the effectiveness of amylase enzyme on eliminating starch soils are obtained with or without the reduced levels of amylase enzyme-destabilizing compounds (l e. amme oxide, hydrogen peroxide, citric acid and citrates etc.) as discussed elsewhere m this invention. But dishwashing compositions of the invention will be subjected to acidic stresses created by food soils when put to use, 1 e , diluted and applied to soiled dishes, so if a composition with a pH greater than 8 or 9 is to be more effective, it preferably should contain a buffeπng agent capable of providing a generally more alkaline pH in the composition and in dilute solutions. Dishwashing compositions of the present invention will thus contain from about 0.1% to 15%, preferably from about 1% to 10%, most preferably from about 2% to 8%, by weight, of a buffering agent. The pKa value of this buffering agent should be about 0.5 to 1 0 pH units below the desired pH value of the composition ( with the pKa value determined as described above) Under these conditions the buffering agent most effectively controls the pH while using the least amount thereof.

The buffering agent may be an active detergent in its own right, or it may be a low molecular weight, organic or inorganic material that is used m this composition solely for maintaining an alkaline pH. Preferred buffeπng agents for compositions of this invention are nitrogen-containing mateπals. Some examples are amino acids such as lysme or lower alcohol amines like mono-, di-, and tπ-ethanolamine. The diammes, described m detail above, also act as buffeπng agents and are preferred buffering agents Preferred inorganic buffers/alkalinity sources include the alkali metal carbonates, alkali metal hydroxides and alkali metal phosphates, e.g., sodium carbonate, sodium hydroxide, sodium polyphosphate. Preferred buffeπng system for use in the present detergent compositions include a combination of 0.5 % diamme and 2.5 % citrate and a combination of 0.5 % diamine, 0.75 % potassium carbonate and 1 75 % sodium carbonate. Other preferred nitrogen-containing buffeπng agents are Tπ(hydroxymethyl)amιno methane (HOCH₂)₃CNH₃ (TRIS), 2-ammo-2 -ethyl- 1,3- propanediol, 2-amιno-2-methyl-propanol, 2-ammo-2-methyl-l,3-propanol, disodium glutamate, N-methyl diethanolamide, 1,3-dιammo-propanol N,N'-tetra-methyl-l,3-dιamιno-2-propanol, N,N- bιs(2-hydroxyethyl)glycme (bicme) and N-tπs (hydroxymethyl)methyl glycme (tπcine). Mixtures of any of the above are also acceptable For additional buffers see McCutcheon's EMULSEFIERS AND DETERGENTS, North American Edition, 1997, McCutcheon Division, MC Publishing Company Kirk and WO 95/07971 both of which are incorporated herein by reference.

SURFACTANTS

The compositions of this invention comprise from about 5 % to about 90 %, more preferably from about 25 % to about 70 % by weight surfactant.

Aniomc Surfactants - The anionic surfactants useful in the present invention are preferably selected from the group consisting of linear alkylbenzene sulfonate, alpha olefin sulfonate, paraffin sulfonates, alkyl ester sulfonates, alkyl sulfates, alkyl alkoxy sulfate. alkyl sulfonates, alkyl alkoxy carboxylate, alkyl alkoxylated sulfates, sarcosinates, taunnates, and mixtures thereof. An effective amount, typically from about 0.5% to about 90%, preferably about 5% to about 50%, more preferably from about 10 to about 30%, by weight of anionic detersive surfactant can be used in the present invention.

Suitable examples of anionic surfactants may be found in copendmg provisional patent application of Chandπka Kastuπ et al., entitled "Liquid Detergent Compositions Compπsing Polymeric Suds Enhancers", having P & G Case No. 6938P, serial no. 60/066,344 and filed on November 21, 1997, which is hereby incorporated by reference. Further examples of suitable anionic surfactants are given in "Surface Active Agents and Detergents" (Vol. I and LI by

Schwartz, Perry and Berch). A variety of such surfactants are also generally disclosed in U.S. Patent 3,929,678, issued December 30, 1975 to Laughhn, et al at Column 23, line 58 through Column 29, line 23. Suitable anionic surfactants may further be found in U.S. Pat. No. 5,415,814 issued 16 May 1995, to Ofosu-Asante et al., all of which are hereby incorporated by reference. Amphoteπc surfactants - The amphoteπc surfactants useful m the present invention are preferably selected from amine oxide surfactants. Amine oxides are semi-polar nomonic surfactants and include water-soluble amme oxides containing one alkyl moiety of from about 10 to about 18 carbon atoms and 2 moieties selected from the group consisting of alkyl groups and hydroxyalkyl groups containing from about 1 to about 3 carbon atoms; water-soluble phosphine oxides containing one alkyl moiety of from about 10 to about 18 carbon atoms and 2 moieties selected from the group consisting of alkyl groups and hydroxyalkyl groups containing from about 1 to about 3 carbon atoms; and water-soluble sulfoxides containing one alkyl moiety of from about 10 to about 18 carbon atoms and a moiety selected from the group consisting of alkyl and hydroxyalkyl moieties of from about 1 to about 3 carbon atoms. Semi-polar amphoteπc detergent surfactants including amine oxide surfactants are discussed in greater detail in U.S. Pat. No. 5,167,872, issued December 1, 1992, to Pancheπ et al. These amme oxide surfactants in particular include Ci o-Cjg alkyl dimethyl amine oxides and

Cg-Ci 2 alkoxy ethyl dihydroxy ethyl amme oxides.

Also suitable are amine oxides such as propyl amme oxides, represented by the formula.

wherein R, is an alkyl. 2 -hydroxyalkyl, 3-hydroxyalkyl, or 3-alkoxy-2-hydroxypropyl radical in which the alkyl and alkoxy, respectively, contain from about 8 to about 18 carbon atoms, R₂ and R₃ are each methyl, ethyl, propyl, isopropyl, 2-hydroxyethyl, 2-hydroxypropyl, or 3- hydroxypropyl and n is from 0 to about 10.

Other suitable, non-limiting examples of amphoteπc detergent surfactants that are useful in the present invention include amido propyl betaines and derivatives of aliphatic or heterocyclic secondary and ternary amines in which the aliphatic moiety can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 24 carbon atoms and at least one aliphatic substituent contains an anionic water-solubihzing group.

Further examples of suitable amphoteπc surfactants are given in "Surface Active Agents and Detergents" (Vol. I and II by Schwartz, Perry and Berch), hereby incorporated by reference.

Preferably the amphoteπc surfactant is present in the composition in an effective amount, more preferably from about 0.1% to about 20%, even more preferably about 0.1% to about 15%, even more preferably still from about 0.5% to about 10%,by weight.

Noniomc Surfactants - Examples of nomonic detergent surfactants that are useful in the present invention are generally disclosed in U.S. Pat. No. 3,929,678, Laugh n et al., issued Dec 30, 1975, at column 13, line 14 through column 16, line 6, incorporated herein by reference. These include: (I) the polyethylene, polypropylene, and polybutylene oxide condensates of alkyl phenols.;

(n) alcohol ethoxylates which are the condensation products of aliphatic alcohols with from about 1 to about 25 moles of ethylene oxide. They are represented by the general formula: R(OCH₂CH₂)_nOH .

(in) another type of noniomc co-surfactant suitable for use in combination with the polyhydroxy fatty acid amides in the noniomc surfactant component herein comprises the ethylene oxide-propylene oxide block co-polymers that function as polymeric surfactants (these are also discussed separately under the solvents heading); (IV) the condensation products of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol; and (v) alkylpolysacchaπdes disclosed in U.S. Pat. No 4,565,647, Llenado, issued Jan. 21 , 1986, having a hydrophobic group containing from about 6 to about 30 carbon atoms, preferably from about 10 to about 16 carbon atoms and a polysacchaπde.

Secondary Surfactants - Secondary detersive surfactant can be selected from the group consisting of cationics, ampholytics, zwitterionics, and mixtures thereof By selecting the type and amount of detersive surfactant, along with other adjunct ingredients disclosed herein, the present detergent compositions can be formulated to be used in the context of laundry cleaning or in other different cleaning applications, particularly including dishwashing. The particular surfactants used can therefore vary widely depending upon the particular end-use envisioned. Suitable secondary surfactants are described in detail in the copending provisional patent application of Chandπka Kastuπ et al., entitled "Liquid Detergent Compositions Compπsmg Polymeric Suds Enhancers", having P & G Case No. 6938P, application seπal no. 60/066,344, incorporated above.

Diam es - Diamines used herein in detergent compositions in combination with detersive surfactants at levels and ratios (discussed in further detail below) which are effective for achieving at least a directional improvement in cleaning performance. In the context of a hand dishwashing composition, such "usage levels" can vary depending not only on the type and seventy of the soils and stains, but also on the wash water temperature, the volume of wash water and the length of time the dishware is contacted with the wash water. Since the habits and practices of the users of detergent compositions show considerable variation, the composition will preferably contain at least about 0.1%, more preferably at least about 0.2%, even more preferably, at least about 0.25%, even more preferably still, at least about 0.5% by weight of said composition of diamine. The composition will also preferably contain no more than about 15%, more preferably no more than about 10%, even more preferably, no more than about 6%, even more preferably, no more than about 5%, even more preferably still, no more than about 1.5% by weight of said composition of diamine.

In one of its several aspects, this invention provides a means for enhancing the removal of greasy/oily soils by combining the specific diammes of this invention with surfactants. Greasy/oily "everyday" soils are a mixture of tπglyceπdes, hpids, complex polysacchaπdes, fatty acids, inorganic salts and protemaceous matter.

Thus diamines, in combination with amphoteπc and anionic surfactants in the specific ratios discussed below, offer the benefit of improved grease and tough food cleaning which allows the elimination or reduction in the amount of divalent ions in the preferred embodiments of the present formula. This improved cleaning is a result of diamines' proclivity as a buffering agent to increase the alkalinity of the dishwashing composition.

It is preferred that the diamines used in the present invention are substantially free from impurities. That is, by "substantially free" it is meant that the diamines are over 95% pure, i.e., preferably 97%, more preferably 99%, still more preferably 99 5%, free of impuπties. Examples of impurities which may be present in commercially supplied diamines include 2 -Methyl- 1,3- diaminobutane and alkylhydropyπmidine. Further, it is believed that the diammes should be free of oxidation reactants to avoid diamine degradation and ammonia formation.

As is discussed in greater detail below, making the compositions free of hydrogen peroxide is important when the compositions contain an enzyme. Even small amounts of hydrogen peroxide can cause problems with enzyme containing formulations. However, the diamine can react with any peroxide present and act as an enzyme stabilizer and prevent the hydrogen peroxide from reacting with the enzyme. The only draw back of this stabilization of the enzymes by the diamine is that the nitrogen compounds produced are believed to cause the malodors which can be present m diamine containing compositions. Having the diamme act as an enzyme stabilizer also prevents the diamme from providing the benefits to the composition for which it was oπginally put m to perform, namely, grease cleaning, sudsing, dissolution and low temperature stability. Therefore, it is preferred to minimize the amount of hydrogen peroxide present as an lmpuπty m the inventive compositions either by using components which are substantially free of as an enzyme stabilizer, because of the possible generation of hydrogen peroxide and/or by using non-diamme antioxidants even though the diamine can act malodorous compounds and the reduction m the amount of diamine available present to perform its primary role.

Preferred organic diammes are those in which pKl and pK2 are in the range of about 8.0 to about 11.5, preferably m the range of about 8.4 to about 11, even more preferably from about 8.6 to about 10.75. Preferred mateπals for performance and supply considerations are 1,3- bιs(methylamme)-cyclohexane (pKa=10 to 10.5), 1,3 propane diamine (pKl=10.5; pK2=8.8), 1,6 hexane diamine (pKl=l 1; pK2=10), 1,3 pentane diamme (Dytek EP) (pKl=10.5; pK2=8.9), 2-methyl 1,5 pentane diamine (Dytek A) (pKl=l 1.2; pK2=10.0). Other preferred mateπals are the primary/primary diammes with alkylene spacers ranging from C4 to C8. In general, it is believed that primary diammes are preferred over secondary and tertiary diammes.

Definition of pKl and K2 - As used herein, "pKal " and "pKa2" are quantities of a type collectively known to those skilled m the art as "pKa" pKa is used herein m the same manner as is commonly known to people skilled in the art of chemistry. Values referenced herein can be obtained from literature, such as from "Critical Stability Constants. Volume 2, Amines" by Smith and Mattel, Plenum Press, NY and London, 1975 Additional information on pKa's can be obtained from relevant company literature, such as information supplied by Dupont, a supplier of diamines As a working definition herein, the pKa of the diammes is specified in an all-aqueous solution at 25°C and for an ionic strength between 0.1 to 0.5 M The pKa is an equihbπum constant which can change with temperature and ionic strength; thus, values reported m the literature are sometimes not in agreement depending on the measurement method and conditions To eliminate ambiguity, the relevant conditions and/or references used for pKa's of this invention are as defined herein or in "Critical Stability Constants Volume 2, Ammes" One typical method of measurement is the potentiometπc titration of the acid with sodium hydroxide and determination of the pKa by suitable methods as described and referenced in "The Chemist's Ready Reference Handbook" by Shugar and Dean, McGraw Hill, NY, 1990.

It has been determined that substituents and structural modifications that lower pKl and pK2 to below about 8.0 are undesirable and cause losses m performance. This can include substitutions that lead to ethoxylated diammes, hydroxy ethyl substituted diammes, diamines with oxygen in the beta (and less so gamma) position to the nitrogen m the spacer group (e.g., Jeffamme EDR 148). In addition, mateπals based on ethylene diamme are unsuitable. The diammes useful herein can be defined by the following structure:

^R2- -C_Xv C_v .R4

N A N

R₃ ^S R₅ . wherein R2.5 are independently selected from H, methyl, -CH3CH2, and ethylene oxides; C_x and C_v are independently selected from methylene groups or branched alkyl groups where x+y is from about 3 to about 6; and A is optionally present and is selected from electron donating or withdrawing moieties chosen to adjust the diamme pKa's to the desired range. If A is present, then x and y must both be 1 or greater.

Specific diammes suitable for use in the present invention are discussed in greater detail in U. S. Pat. No. 5,990,065, to Vinson et al., issued Nov. 23, 1999, which is hereby incorporated by reference. Ratio of anionic to amphotenc to diamme - In a preferred embodiment of the present invention, the LDL compositions contain anionic surfactant, amphoteπc surfactants, and diamme m a ratio of anionic: amphotenc: diamme from about 100 40: 1 to about 9:0.5: 1, by mole. preferably the ratio of the anionic: amphotenc diamine is from about 27:8- 1 to about 11 :3: 1, by mole. It has been found that detergent compositions containing anionic surfactant, amphotenc surfactant and diamme in this specific ratio range provide improved low temperature stability, deliver better grease removal and tough food cleaning benefits as well as improved hard water cleaning.

Calcium Or Magnesium Ions - The presence of calcium and/or magnesium (divalent) ions improves the cleaning of greasy soils for various compositions, i.e. compositions containing alkyl ethoxy carboxylates and/or polyhydroxy fatty acid amide. This is especially true when the compositions are used in softened water that contains few divalent ions. It is believed that calcium and/or magnesium ions increase the packing of the surfactants at the oil/water interface, thereby reducing mterfacial tension and improving grease cleaning.

Compositions of the invention hereof containing magnesium and/or calcium ions exhibit good grease removal, manifest mildness to the skin, and provide good storage stability.

Preferably, the magnesium or calcium ions are added as a hydroxide, chloride, acetate, formate, oxide or nitrate salt to the compositions of the present invention.

The amount of calcium or magnesium ions present in compositions of the invention will be dependent upon the amount of total surfactant present therein, including the amount of alkyl ethoxy carboxylates and polyhydroxy fatty acid amide. When calcium ions are present in the compositions of this invention, the molar ratio of calcium ions to total anionic surfactant is from about 0.25: 1 to about 2:1 for compositions of the invention.

Formulating such divalent ion-containing compositions in alkaline pH matrices may be difficult due to the incompatibility of the divalent ions, particularly magnesium, with hydroxide ions. When both divalent ions and alkaline pH are combined with the surfactant mixture of this invention, grease cleaning is achieved that is superior to that obtained by either alkaline pH or divalent ions alone. Yet, duπng storage, the stability of these compositions becomes poor due to the formation of hydroxide precipitates. Therefore, chelatmg agents discussed herein below may also be necessary.

The ions are present in the compositions hereof at an active level of from about 0.1% to 4%, preferably from about 0.3% to 3.5%, more preferably from about 0.5% to 1%, by weight. Although either species of divalent ion provides benefits when included in a detergent composition, preferably the detergent compositions of the present invention contain no calcium ions.

Solvents - The present liquid detergent compositions contain either diols or polymenc glycols or a mixture of both diols and polymenc glycols (polymenc glycols are composed of ethylene oxide (EO) and propylene oxide (PO) groups). In addition to diols and polymenc glycols, a variety of other water-miscible liquids such as lower alkanols, diols. other polyols, ethers, ammes, and the like may be used in the present invention Particularly preferred are the C1-C4 alkanols Suitable solvents are discussed in greater detail in the provisional patent application of Clarke et al, entitled "Diols and Polymeric Glycols for Improved Dishwashing Detergent Compositions", having P & G Case No. 7408 provisional serial no. 60/1 19,044, filed on February 8, 1999, which is hereby incorporated by reference.

When present the composition will preferably contain at least about 0.01%, more preferably at least about 0.5%, even more preferably still, at least about 1% by weight of the composition of solvent. The composition will also preferably contain no more than about 20%, more preferably no more than about 10%, even more preferably, no more than about 8% by weight of the composition of solvent.

Suds Booster - Another component which may be included in the composition of this invention is a suds stabilizing surfactant (suds booster) at a level of at least about 0.5%, preferably at least about 2%, more preferably at least about 5%. The composition will also contain no more than about 20%, preferably no more than about 15%, more preferably, no more than about 10% of said suds booster.

Suds stabilizing surfactants operable in the instant composition are: sultanas, complex betames, betames, ethylene oxide condensates, fatty acid amides, amme oxide semi-polar noniomcs, and catiomc surfactants. Also suitable as suds boosters are the polymeric suds stabilizers disclosed in the provisional application of Clarke et al., entitled "Diols and Polymenc Glycols for Improved Dishwashing Detergent Compositions", having P & G Case No. 7408 provisional seπal no. 60/119,044, filed on February 8, 1999, which is hereby incorporated by reference. Builder (Chelants) - The compositions according to the present invention may further compnse builders. A general descπption of builder materials is contained m U. S. Pat. No. 5,990,065, to Vinson et al., issued Nov. 23, 1999, which is hereby incorporated by reference. If detergency builder salts are included, they will be included in amounts of from 0.5 % to 50 % by weight of the composition preferably from 5% to 30% and most usually from 5% to 25% by weight.

Other Ingredients - The detergent compositions will further preferably compnse one or more detersive adjuncts selected from the following: soil release polymers, polymenc dispersants, polysacchaπdes, abrasives, bactencides and other antimicrobials, tarnish inhibitors, builders, enzymes, dyes, buffers, antifungal or mildew control agents, insect repellents, perfumes, hydrotropes, thickeners, processing aids, bπghteners, anti-corrosive aids, stabilizers antioxidants and chelants A wide variety of other ingredients useful in detergent compositions can be included in the compositions herein, including other active ingredients, carriers, hydrotropes, antioxidants, processing aids, dyes or pigments, solvents for liquid formulations, solid fillers for bar compositions, etc If high sudsmg is desired, suds boosters such as the C I Q-C I 6 alkanolamides can be incorporated into the compositions, typically at 1%-10% levels The C J Q-

C14 monoethanol and diethanol amides illustrate a typical class of such suds boosters. Use of such suds boosters with high sudsing adjunct surfactants such as the amme oxides, betames and sultanas noted above is also advantageous. COMPOSITION FORM AND METHOD OF USAGE

Composition Form - The present liquid dishwashing detergent compositions may optionally be in the form of either a microemulsion or a bicontmuous microemulsion. By "microemulsion," or "conventional microemulsion" it is meant a thermodynamically stable mixture of oil and water in which a discontinuous domain is suspended in a continuous domain. The discontmous domain is in the form of spherical droplets having radii of between 100 and 1000 A. When the discontinuous domain is oil and the continuous domain is water, it is an oil- m-water microemulsion. When the discontinuous domain is water and the continuous domain is oil, it is a water-m-oil microemulsion. See Surfactant Science Series, Volume 6 Emulsions and Emulsion Technology Part 1 (edited by Kenneth J. Lissant), p. 127 Marcel Dekker, New York (1974); Surfactant Science Series, Volume 66 Industrial Applications of Emulsions (edited by Conxita Solans et al.), p. 2. Marcel Dekker, New York (1997).

By "bicontmuous microemulsion" it is meant a thermodynamically stable mixture of oil and water wherein two continuous, interconnecting and separate domains, separated by a surfactant interface, are present rather than there being both a continuous and a discontinuous domain. A bicontmuous microemulsion is classified as a Wmsor Type III microemulsion. P. A Wmsor, Chem. Rev 68, p. 3-6 (1968); Surfactant Science Series, Volume 6 Emulsions and Emulsion Technology Part 1 (edited by Kenneth J. Lissant), p. 191-92 Marcel Dekker, New York (1997). Surfactant Science Series, Volume 66 Industrial Applications of Emulsions (edited by Conxita Solans et al.), p. 158, Marcel Dekker, New York (1997). When the detergent compositions are present in the form of a microemulsion or bicontmuous microemulsion, they will compnse (in addition to a selection of the ingredients described above): (a) a microemulsion-formmg solvent, (b) a liquid hydrocarbon component; and (c) an aqueous liquid carrier. Suitable examples of each of these components as well as overwell formulation directions are discussed m the provisional patent application of Mark L. Kacher et al , entitled "Light Duty Liquid Dishwashing Compositions in the Form of Microemulsions", filed on April 8, 1999, having serial no. 60/128,351 and P&G Case No 7504P, which is hereby incorporated by reference. Method of Usage - The compositions of this invention can be used to form aqueous washing solutions for use hand dishwashing. Generally, an effective amount of such compositions is added to water to form such aqueous cleaning or soaking solutions. The aqueous solution so formed is then contacted with the dishware, tableware, and cooking utensils.

An effective amount of the detergent compositions herein added to water to form aqueous cleaning solutions can compnse amounts sufficient to form from about 500 to 20,000 ppm of composition in aqueous solution. More preferably, from about 800 to 5,000 ppm of the detergent compositions herein will be provided in aqueous cleaning liquor.

The following examples are illustrative of the present invention, but are not meant to limit or otherwise define its scope. All parts, percentages and ratios used herein are expressed as percent weight unless otherwise specified.

The following examples are illustrative of the present invention, but are not meant to limit or otherwise define its scope. All parts, percentages and ratios used herein are expressed as percent weight of the composition unless otherwise specified. TABLE I

A light-duty liquid dishwashing detergent formula having the following composition is prepared:

Example 1 Example 2 Example 3 Example 4 Example 5

AES¹ 27.0 26.0 20.0 26.0 20

Amme oxide² 6.5 7.0 4.0 - 6.0

Noniomc³ 2.4 3.0 2.0 3.5 3.0

Diamine⁴ 0.6 1.0 0.5 - -

Suds boosting 0.8 1.0 0.5 — 0.7 polymer⁵

Polypropylene 1.4 1.5 1.0 — 10.0 glycol

Ethanol 6.0 5.8 2.0 5.6

Amylase 0.002 0.005 0.0005 0.002 0.001 NaOH topH8.5 topH9.5 to pH 9.0 to pH 9.0 topH8.5

Limonene . . . . go

Water and Balance Balance Balance Balance Balance

Misc.

1: C₁₂-₁₃ alkyl ethoxy sulfonate containing an average of 0.6 ethoxy groups. 2: C_]2-Cι₄ Amine oxide.

3: Noniomc may be either C_π Alkyl ethoxylated surfactant containing 9 ethoxy groups or Cio Alkyl ethoxylated surfactant containing 8 ethoxy groups.

4: 1,3 bιs(methylamιne)-cyclohexane

5: Polymer is (N,N-dιmethylamιno)ethyl methacrylate homopolymer

Claims

WHAT IS CLAIMED IS :

1 A liquid dishwashing detergent composition characterized by

(a) from 0.0001% to 5%, of an amylase enzyme; and

(b) at least 0.5% of a suds booster; wherein the composition has a pH of greater than 8 and the detergent composition has especially desirable greasy soil removal performance when used to clean heavily soiled kitchen articles

2. A liquid dishwashing detergent composition according to Claim 1 is further characterized by an enzyme selected from the group consisting of cellulases, hemicellulases, peroxidases, proteases, gluco-amylases, hpases, cutinases, pectinases, xylanases, reductases, oxidases, phenoloxidases, hpoxygenases, hgnmases, pullulanases, tannases, pentosanases, malanases, β-glucanases, arabinosidases and mixtures thereof.

3. A liquid dishwashing detergent composition according to any of claims 1-2 wherein the amylase enzyme has a specific activity at least 25% higher than the specific activity of Termamyla at a temperature range of 25°C to 55°C and at a pH value in the range of 8 to 10, measured by the Phadebasa a-amylase activity assay.

4. A liquid dishwashing detergent composition according to any of claims 1-3 further charactenzed by a low molecular weight organic diamme having a pKl and a pK2, wherein the pKl and the pK2 of said diamme are both in the range of from 8.0 to 11.5;

5. A liquid dishwashing detergent composition according to any of claims 1-4 wherein said diamme is selected from the group consisting of:

^S- .^Xs . „C_V R4

N A N

R₃ ^NR₅ wherein R2.5 are independently selected from H, methyl, ethyl, and ethylene oxides; C_x and C_v are independently selected from methylene groups or branched alkyl groups where x+v is from 3 to 6; and A is optionally present and is selected from electron donating or withdrawing moieties chosen to adjust the diamine pKa's to the desired range; wherein if A is present, then both x and y must be 2 or greater.

6. A liquid dishwashing detergent composition according to any of claims 1-5 further characterized by a buffering agent and wherein the composition has a pH of from 10 to 11.5.

7 A liquid dishwashing detergent composition according to any of claims 1-6 wherein said diam e is selected from the group consisting of dimethyl aminopropyl amine, 1,6-hexane diamine, 1,3 propane diamine, 2-methyl 1,5 pentane diamine, 1,3-Pentanedιamme, 1- methyl-diaminopropane, Jeffam e EDR 148, Isophorone diamine, l,3-bιs(methylamιne)- cyclohexane and mixtures thereof.

8. A liquid dishwashing detergent composition according to any of claims 1-7 further characterized by an anionic surfactant and an amphotenc surfactant and wherein the mole ratio of said anionic surfactant to said amine oxide to said diamme is from 100-40: 1 to 9:0.5: 1.

9 A method for cleaning a substrate in a manual dishwashing operation charactenzed by the steps of:

(a) contacting the substrate with a liquid dishwashing detergent composition prepared according to any of claims 1-8; and

(b) allowing the detergent composition to remain in contact with the substrate for a sufficient time to provide effective cleaning benefits to the substrate.