CA2088230A1 - Detergent composition - Google Patents

Abstract

C 7296 (R) ABSTRACT

DETERGENT COMPOSITION

A chlorine bleach-free aqueous liquid machine dishwashing composition having solution pH 7-11 contains proteolytic enzyme, detergency builder, sodium silicate having SiO2:Na20 ratio of from 2.0-3.2 and organic surfactant which comprises (i) glycoside surfactant, (ii) anionic sulphate or sulphonate including a C8 to C22 alkyl or alkenyl group or (iii) ethoxylated C6 to C16 fatty alcohol with HLB of at least 10.5, or a mixture of (i), (ii) and/or (iii). If (iii) is used without (ii) it must be an ethoxylated C6 to C12 alcohol, or glycoside surfactant must also be present.
Proteolytic enzyme plus the specified surfactant gives a synergistic improvement in removal of proteinaceous soil.

Description

~g2~
1 c 7296 (P~) DETERGENT COMPOSITION

Field of the Invention 5 The present invention relates to an aqueous liquid detergent product particularly adapted for use in a machine dishwasher.

Background and Prior Art 10 Liquid automatic dishwasher detergent compositions, both aqueous and non-aqueous, have recently received much attention and the aqueous products have achieved commercial popularity.

15 The acceptance and popularity of the liquid formulations as compared to the more conventional powdered products stems from the convenience and pe.~o~l~.anc~ u~ ~n~ ul~ ~Loducts.
However the currently available and proposed liquid product formulations are based on the concept of the conventional 20 machine dishwashing powder compositions which are highly alkaline and highly built products containing a chlorine bleach (see for example EP-A-0,517,308 and EP-A-517,309).

It has now surprisingly been found that a mild and yet quite effective aqueous liquid machine dishwashing detergent composition can be formulated based on certain surfactants and proteolytic enzymes wherein there is an apparent synergistic effect between the active and the protease enzyme, especially in the removal of protein soil.
The use of glycosides in detergent compositions has been disclosed in a number of documents. WO 86/05187 (Staley) discloses laundry detergent compositions comprising glycoside surfactant and enzyme. Various enzymes are 35 mentioned.

DE 38 33 047 discloses acidic powdered dishwashing compositions containing alkyl glycoside în combination with 2~88~3~

2 C 72~6 (R) other surfactant and amylase. These compositions are acidic and have solution pH below 6.

Summary of the Invention 5 According to the invention there is provided a chlorine bleach-free aqueous liquid machine dishwashing detergent composition comprising :
(a) from 0.0002 to 0.05 Anson units per gram of the composition of a proteolytic enzyme;

(b) from 5 to 90% by weight of a detergency builder;

(c) from 1 to 40% by weight of sodium or potassium silicate having SiO2:Na2O or Sio2:K2o ratio of from about 2.0 to about 3~2.

(dj fro.n J ~0 5u~ by weight of an organic surfactant selected from the group of:

(i) glycoside surfactants;
(ii) anionic surfactants with a hydrophilic head group which is, or which contains a sulphate or sulphonate group and a hydrophobic portion which is or which contains an alkyl or alkenyl group of 8 to 22 carbon atoms;
(iii) ethoxylated fatty alcohols of formula Ro(cH2cH2o)nM
where R is an alkyl group of 6 to 16 carbon atoms and n has an average value which is at least four and is sufficiently high that the HLB value of the ethoxylated fatty alcohol is 10.5 or greater, with the proviso that if ethoxylated fatty alcohol (iii) is used without anionic surfactant (ii) the majority of its alkyl groups R contain 6 to 12 carbon atoms; and (iv) mixtures thereof;

2~8~23~

3 C 7296 (R) (e) water, said composition having a pH of 7 to 11, if added deionised water at a concentration of 2 g/l.

In a second aspect this invention provides a method of 5 washing crockery and/or glassware comprising exposing the crockery and/or glassware to a mixture of water and a detergent composition as specified above. In another aspect the invention provides use of such a composition in machine dishwashing.
Detailed Description The Proteolytic Enzyme Protease can, for example, be used in an amount ranging from 15 about the order of 0.0002 to about the order of 0.05 Anson units per gram of the detergent composition, preferably vï to ~.u25 Anson units. Expressed in other Ullit~ tlle protease can also be included in the compositions in amounts of the order of from about 0.5 to 100 GU/mg of the detergent 20 composition. Preferably, the amount ranges from 1 to 50, and particularly preferably from 2 or even 5 to 15 or 20 GU/mg of composition.

A GU is a Glycine Unit, defined as the proteolytic enzyme 25 activity which, under standard conditions, during a 15-minute incubation at 40C with N-acetyl casein as substrate, produces an amount of NH2-group equivalent to 1 micromole of glycine.

Enzyme activities are sometimes also measured in kilo Novo units (KNPU): a measurement depending on the type of protease and assay used. We have found that the KNPU/AU
ratio is in the range of about 3:1 to 5:1 for Alcalase, Esperase and Savinase and for the purpose of these formulations it is not necessary to be more precise.

Preferred examples of protease enzyme to be used in the present compositions are the subtilisin varieties sold as 2 ~ 3 ~

4 C 7296 (R) Savinase (TM of Novo-Nordisk A/S) or Maxacal (TM of Gist-Brocades/IBIS) or as Opticlean (ex MKC) or AP122 (ex Showa Denko), which has pI approximately 10. Other useful examples of proteases include Maxatase, Esperase, Alcalase (Trade 5 Marks), protinase K and subtilisin BPN'. Protinase K can also be used.

Orqanic surfactant 10 Glycoside Surfactant This will be nonionic in character and of course includes glycoside residues. Suitably it is of the general formula :
o Il R(R')t(G)x or RCO(R'O)t(G)X

in which G is a residue Ol a pentose OL n2xose, k ~ iS an alkoxy group, x is at least unity and R is an organic hydrophobic group which is ~referably aliphatic, either saturated or unsaturated, notably straight or branched alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl. However, it may include an aryl group, for example alkyl-aryl, alkenyl-aryl and hydroxyalkyl-aryl. It is envisaged that R may be from 6 to 20 carbon atoms.
Particularly preferred is that R is alkyl or alkenyl of 7 to 14 or 16 carbon atoms, especiall,v 7 to 12.

The value of t in the general formula above is preferably zero, so that the -(R'O)t- Ullit of the general formula is absent. In that case the general formula becomes :
o Il RO(G)X or RCO(G)X
If t is non-zero, it is preferred that R'O is an ethylene oxide residue. Other possibilities are propylene oxide and glycerol residues. If the parameter t is non-zero so that 2 0 ~
C 7296 (R) R'O is present, the value of t (which may be an average value) will preferably lie in the range from 0.5 to 10.

The group G is typically derived from fructose, glucose, 5 mannose, galactose, talose, gulose, allose, altrose, idose, arabinose, xylose, lyxose and/or ribose. Preferably, the G
is provided substantially exclusively by glucose units.
Intersaccharide bonds may be from a 1-position to a 2, 3, 4 or 6-position of the adjoining saccharide. ~ydroxyl groups 10 on sugar residues may be substituted., e.g. etherified with short alkyl chains of 1 to 4 carbon atoms. Preferably a sugar residue bears no more than one such substituent.

I'he value x, which is an average, is usually termed the 15 degree of polymerization. Desirably x varies between 1 and 8. Values of x may lie between 1 and 3, especially l and 1.8.

Alkyl polyglycosides of formula RO(G)X, i.e. a formula as 20 given above in which t is zero, are available from BASF and Henkel.

Alkyl polyglycosides of particular interest have x in the narrow range from 1 or 1.2 up to 1.4 or especially 1.3. If x 25 exceeds 1.3, it preferably lies in the range from 1.3 or 1.4 to 1.8.

When x lies in the range from 1 to 1.4, it is preferred that R is C8 to C14 alkyl or alkenyl.
0-alkanoyl glucosides are described in International Patent Application WO 88/10147 (Novo Industri A/S). In particular the surfactants described therein are glucose esters with the acyl group attached in the 3- or 6-position such as 3-0-acyl-D-glucose or 6-0-acyl-D-glucose. Notable are 6-0-alkanoyl glucosides, in which the alkanoyl group incorporates an alkyl or alkenyl group having from 7 to 13 preferably 7, 9 or 11 carbon atoms. The glucose residue may 20882~

6 C 7296 (R) be alkylated in its l-position with an alkyl group having from 1 to 4 carbon atoms, such as ethyl or isopropyl.
Alkylation in the l-position enables such compounds to be prepared by regiospecific enzymatic synthesis as described 5 by Bjorkling et al. (J. Chem. Soc., Chem. Commun. 1989 p934).

While esters of glucose are contemplated especially, it is envisaged that corresponding materials based on other 10 reducing sugars, such as galactose and mannose are also suitable.

Anionic surfactant Preferred anionic surfactants are one or a mixture of:
primary alkyl sulphate of formula:
RlOS03M

where Rl is a primary alkyl group of 8 to 18 carbon atoms and M is a solubilising cation, fatty acid ester sulphonate of formula R2CHCo2R3 I

25 where R2 is an alkyl group of 6 to 16 carbon atoms, R3 is an alkyl group of 1 to 4 carbon atoms and M is a solubilising cation, alkyl benzene sulphonate of formula where R is an alkyl group of 10 to 16 carbon atoms and M is a solubilising cation, alkyl ether sulphate of formula R10 (CH2CH20) nS3M
where Rl is a primary alkyl group of 8 to 18 carbon atoms, n has an average value in the range from 1 to 6 and M is a 208~230 7 C 7296 (R) solubilising cation.

Especially preferred as surfactant is primary alkyl sulphate. In its general formula the solukilising cation may be a range of cations which are general monovalent and confer water solubility. Alkali metal, notably sodium, is especially envisaged. Other 10 possibilities are ammonium and substituted ammonium, such as trialkanolammonium.

The alkyl group Rl may have a mixture of chain lengths. It is preferred that at least two thirds of the R1 alkyl groups 15 have a chain length of 8 to 14 carbon atoms. This will be the case if Rl is coconut alkyl, for example.

If the surfactant is fatty acid ester sulphonate, alkyl benzene sulphonate or alkyl ether sulphonate the solubilising cation M may be a range OL cations as discussed above for alkyl sulphate.

In the general formula for fatty acid ester sulphonate:

the group R2 may have a mixture of chain lengths. Preferably at least two thirds of these groups have 6 to 12 carbon atoms. This will be the case when the moiety:

I

is derived from a coconut source, for instance.

The group R may be any C1 to C4 alkyl group. Straight chain alkyl may be preferred, notably methyl or ethyl.

2~8~23~
~ C 7296 (R) In the general formula formula of alkyl benzene sulphonate:

5 The group R4 may be a mixture of chain lengths. Preferred are straight chains of ll to 14 carbon atoms.

In the general formula for alkyl ether sulphate:

R10 (CH2CH20) nS3M

the group Rl is as discussed for alkyl sulphate. Preferably n has an average value of 2 to 5.

Nonionic surfactant Ethoxylated fatty alcohol may be used alone or in admixture with anionic surfactants, especially the preferred surfactants ab~e. ~ow~ L i~ is ustd alone then the fatty alcohol must be of limited chain length so that average chain lengths of the alkyl group R in the general formula:
Ro(cH2cH2o)nH

is from 6 to 12 carbon atoms. This is preferred in any event, and especially preferred if the weight of anionic surfactant is less than half the weight of ethoxulated fatty alcohol.

Notably the group R may have chain lengths in a range from 9 to 11 carbon atoms.

An ethoxylated fatty alcohol normally is a mixture of molecules with different numbers of ethylene oxide residues.
Their average number, n, together with the alkyl chain length, determines whether the ethoxylated fatty alcohol has 35 a hydrophobic character (low HLB value) or a hydrophilic character (high HLB value). For this invention the HLB value should be 10.5 or greater. This requires the average value of n to be at least 4, and possibly higher. The numbers of 2~8~23~
g C 7296 (R) ethylene oxide residues may be a statistical distribution around the average value. However, as is known, the distribution can be affected by the manufacturing process or altered by fractionation after ethoxylation.

Particularly preferred ethoxylated fatty alcohols have a qroup R which has 9 to ll carbon atoms while n is from 5 to 8.

10 Other surfactant The above surfactant, or a mixture of two or more of them, may possibly be accompanied by some other detergent active, usually in a lesser quantity. Preferably the amount of any other detergent surfactant will be no more than one third of 15 the total weight of detergent surfactant present, or even no more than one quarter.

If other surfactant is included it may be anionic or nonionic in character, or possibly amphoteric or zwitterionic. Cationic surfactant is possible if anionic is absent, but is not preferred. Soap may optionally be included, as well as non-soap surfactants.

One significant possibility is the use of a surfactant or 25 mixture of surfactants of the above specified anionic and~or nonionic types, together with glycoside surfactants of the above specified type.

As mentioned, the amount of glycoside surfactant, anionic surfactant and/or ethoxylated fatty alcohol surfactant will be from 3 to 50% by weight of the composition. Desirably the total amount of surfactant lies in the same range. Preferred ranges, both for the specified surfactant and total surfactant are 3 to 30% by weiqht, more preferably, in the 35 range from 5 or 10% to 25% by weight.

Deterqent Builder_Materials The cleaning compositions of this invention can contain all C 7296 (R) manner of detergent builders commonly taught for use in automatic dishwashing or other cleaning compositions. The builders can include any of the conventional inorganic and organic water-soluble builder salts, also insoluble inorganic builders or mixtures thereof, and may comprise from 5 to 90% by weight of the detergent composition.

Typical of the well-known inorganic builders are the sodium and potassium salts of the following: pyrophosphate, 10 tripolyphosphate, orthophosphate, carbonate, bicarbonate, sesquicarbonate and borate. Other non-phosphorous salts including (insoluble) crystalline and amorphous aluminosilicates (e.g. zeolites) may be used as well.

15 Preferred builders can be selected from the group consisting of sodium tripolyphosphate, sodium carbonate, sodium blcarbonate and mixtures thereof. When present ln clle~
compositions, sodium tripolyphosphate concentrations will usuaIly range from 2% to 40%, preferably from 5% to 30%.
20 Sodium carbonate and bicarbonate, when present, can range from 10% to 50%, preferably from 20% to 40% by weight of the cleaning compositions. Potassium pyrophosphate is a preferred builder in gel formulations, where it may be used at from 3 to 30%, preferably from 10 to 20%.
Organic detergent builders can also be used in the present invention. They are generally sodium and potassium salts of the following: citrate, malonate or succinate substituted with a C8 to C24 alkyl group, nitrilotriacetates, phytates, 30 polyphosponates, oxydisuccinates, oxydiacetates, carboxymethyloxy succinates, tetracarboxylates, starch, oxidized heteropolymeric polysaccharides, and polymeric polycarboxylates such as polyacrylates of molecular weight of from about 5,000 to about 200,000. Polyacetal 35 carboxylates such as those described in U.S. Patent Nos.
4,144,226 and 4,146,495 may also be used.

2~8823~
11 C 7296 (R) Non-phosphate builders are particularly preferred for environmental reasons.

Sodium citrate is an especially preferred builder. When 5 present, it is preferably used in an amount from about 1% to about 75% of the total weight of the detergent composition, especially 10 to 50% by weight.

The foregoing detergent builders are meant to illustrate but 10 not limit the types of builder that can be employed in the present invention.

Silicate The compositions of this invention contain sodium or 15 potassium silicate at a level of from about 1 to about 40%
by weight of the cleaning composition, more preferably from 5 to 25%, even more preferably from / cu 2~ hlS material is employed as a cleaning ingredient, source of alkalinity, metal corrosion inhibitor and protector of glaze on china 20 tableware. The sodium or potassium silicate usuable herein will have a ratio of SiO2:Na20 or Sio2:K2o of from about 2.0 to about 3.2. Some of the silicate may be in solid form.
Useful is sodium silicate having a ratio of sio2 : Na2O of higher than 2.0, preferably at least 2.4.
If a composition contains less than ~0~ silicate, we prefer to include a zinc salt, such as zinc sulphate, especially if the composition dissolves to give an alkaline pH, e.g. pH
over 8.5. Such a zinc salt serves to protect glassware from 30 attack by an alkaline wash liquor, and may suitably be used in amounts from 0.1 to 3% by weight.

Other Optional Inqredients 35 Bleach system Compositions according to the present invention are free from chlorine bleach compounds but may contain a peroxygen bleach component. If present the amount will preferably lie 20~823~
12 C 7296 (R) in a range from 1 to 30% by weight.

A peroxygen bleach which may be employed is for example sodium perborate. This is preferably accompanied by a b~each 5 activator which allows the liberation of active oxygen species at a lower temperature. A preferred bleach activator is tetraacetyl ethylene diamine (TAED) but other activators for perborate are known and can be used. The amounts of peroxygen bleach and bleach activator in an individual 10 composition preferably do not exceed 20~ and 15% by weight respectively.

Another peroxygen bleach is sodium percarbonate. Yet another is sodium monopersulphate. Further peroxygen bleaches which 15 may be used are alkyl, alkenyl and aryl peroxy organic acids and their metal salts. Typical peroxy acids include (i) ~ervxi~el-zoic acid and ring-substituted peroxybenzoic acids, e.g. peroxy-~-naphthoic acid (ii) aliphatic and substituted aliphatic monoperoxy acids, e.g. peroxylauric acid and peroxystearic acid (iii)1,12-diperoxydodecanedioic acid (DPDA) (iv) 1,9-diperoxyazelaic acid (v) diperoxybrassylic acid; diperoxysebacic acid and diperoxyisophthalic acid (vi) 2-decyldiperoxybutane-1,4-dioic acid.
(vii)phthaloylamidoperoxy caproic acid (PAP).

Thickeners and Stabilizers 30 Thickeners are often desirable for liquid cleaning compositions. Thixotropic thickeners such as smectite clays including montmorillonite (bentonite), hectorite, saponite, and the like may be used to impart viscosity to liquid cleaning compositions. Silica, silica gel, and 35 aluminosilicate may also be used as thickeners. Use of clay thickeners for automatic dishwashing compositions is disclosed, for example, in U.S. Patents Nos. 4,431,559;
4,511,487; 4,740,327; 4,752,409. Use of salts of polymeric 2~23~
13 C 7296 (R) carboxylic acids is disclosed, for example, in UK Patent Application GB 2,164,350A. Commercially available bentonite clays include Korthix H and VWH ex Combustion Engineering, Inc.; Polargel T ex American Colloid Co.; and Gelwhite clays (particularly Gelwhite GP and H) ex English China Clay Co.
Polargel T is preferred as imparting a more intense white appearance to the composition than other clays.

Various polymers may be included. ~hese may in particular 10 assist in detergency building or be polymeric thickeners, which may be used alone or jointly with other types of thickeners. Notable are polymers containing carboxylic or sulphonic acid groups in acid form or wholly or partially neutralised to sodium or potassium salts, the sodium salts 15 being preferred. Preferred polymers are homopolymers and copolymers of acrylic acid and/or maleic acid or maleic alnhydr~e. ~1 especial interest are polyacrylate~, polyalphahydroxy acrylates, acrylic/maleic acid copolymers, and acrylic phosphinates. Other polymers which are 20 especially preferred for use in liquid detergent compositions are deflocculating polymers such as for example disclosed in EP 346995.

The molecular weights of homopolymers and copolymers are 25 generally 1000 to 150,000, preferably 1500 to 100,000.
Polyacylate thickeners may well have molecular weights from 300,000 up to 6 million. The amount of any polymer may lie in the range from 0.5 to 5% or even 10% by weight of the composition.
For liquid formulations with a "gel" appearance and rheology, particularly if a clear gel is desired, a chlorine-stable polymeric thickener is particularly useful.
U.S. Patent No. 4,260,528 discloses natural gums and resins for use in clear autodish detergents, which are not chlorine-stable. Crosslinked acrylic acid polymers manufactured by B.F. Goodrich and sold under the trade name "Carbopol" have been found to be effective for production of 20~8230 14 C 7296 (R) clear gels, and Carbopol g40 having a molecular weight of about 4,000,000 is particularly preferred for maintaining high viscosity with excellent chlorine stability over extended periods. Further suitable chlorine-stable polymeric 5 thickeners are described in U.S. Patent 4,867,896.

The amount of thickener employed in the composition, including any polymeric thickener, may range from 0 to 5%, preferably 1 to 3%.
Stabilizers and/or co-structurants such as long-chain calcium and sodium soaps and C12 to C18 alkyl sulphates are detailed in U.S. Patents Nos. 3,956,158 and 4,271,030 and the use of other metal salts of long-chain soaps is detailed in U.S. Patent No. 4,752,409. The amount of stabilizer which may be used in the liquid cleaning compositions is from about 0.01 to about 5% by weign~ OL ~he co,.lpositlon, preferably 0.1-2%. Such stabilizers are optional in gel formulations. Co-structurants which are found especially 20 suitable for gels include trivalent metal ions at 0.01-4~ of the composition and/or water-soluble structuring chelants at 1-60%. These co-structurants are more fully described in EP-A-323209.

25 Defoamer A significant consideration, in machine dishwashing compositions, is the need to suppress foaming. The agitation conditions in a dishwashing machine are more rigorous than those in a fabric washing machine and lead to foam formation. Some food residues, such as egg and cream, also lead to the generation of foam.

Foam, if it forms, can cause air to be drawn into the circulating pump. This can interfere with proper water 35 circulation and the supply of water to the heating element.
Excessive foam generation can eventually lead to air locking of the pump, which could wreck the machine by stopping the water supply to the heating element.

2~g~3~
C 7296 (R) A composition of the invention may further include defoamer.
Even if the cleaning composition has only low foaming surfactant, presence of a defoamer ean assist to minimize foam which food soils ean generate.

Current maehine dishwashing eompositions contain a nonionic surfaetant whieh includes ethylene oxide and propylene oxide residues. These surfaetants have eloud points below the operating temperature and they therefore form hydrophobie 10 droplets whieh exert an antifoam aetion.

Materials whieh may be utilised as defoamer in a eomposition of this invention inelude mono- and di- C8 to C22 alkyl phosphates and mineral oil/or wax. These may be used as a 15 eombination containing partieles of the insoluble alkyl phosphate together with petroleum jelly. Possible alternatives co ~he alk~l pl.ospnate lnclude ethylene distearamide, ealcium soap and finely divided siliea, espeeially hydrophobed siliea. Mineral oils and waxes whieh 20 may be used include petroleum fraetions, Fischer-Tropseh waxes, ozokerite, eeresin montan wax, beeswax, candelilla wax, camauba wax and mixtures thereof.

A further category of materials whieh may be used are 25 ketones of formula R7CoR8 wherein R7 and R8 are botn alkyl or alkenyl groups eontaining 8 to 24 earbon atoms and sueh that the ketone eontains 25 to 49 carbon atoms. Ketones of this type and their use as antifoam agents in (other) maehine dishwashing compositions, are diselosed in EP-A-324339.

Another eategory of material whieh can be used as a defoameris soap or fatty acid whieh beeomes neutralised to soap in use of the composition. Such soap or fatty aeid should have an aeyl group of 12 to 22 earbon atoms, espeeially 14 to 18 earbon atoms. If soap or fatty acid is used as defoamer some ealeium salt may deliberately be included in the composition, thereby ensuring the presence of calcium ions 2~2~
16 C 7296 (R) to form a calcium soap which exerts the antifoaming action.

If present, the composition may include 0.1 to 30% by weight of defoamer, preferably other than nonionic surfactant. Non-soap defoamer may be used at levels towards the lower end ofthis range, e.g. 0.1 to 10%, preferably 0.5 to 2% or 5%.
Soap or fatty acid can be used as defoamer, and if present may be used in amounts from 0.1 to 30% by weight, especially 0.5 to 10%.

If the surfactant is alkyl sulphate alone, it may be desirable to use a said ketone (in branched chain alcohol), soap or fatty acid as the defoamer and to avoid alkyl phosphates or mineral oil.
Minor amounts of various other components may be present in the cleanlng com~osition. These include anti~scalant~, corrosion-inhibitors anti-redeposition agents, anti-tarnish agents, other enzymes (especially amylase and/or lipase at 0.05-2% by weight, preferably 0.5-1.5%) and other functional additives and perfume.

As revealed above the compositions of this invention may take the form of a liquid or a gel.
The composition is preferably formulated to give a pH in the range 7 to ~1, even better 8 to ll if added to deionized water at a concentration of 2.0 gramsllitre. A particularly preferred pH is 9.0 to 9.5.
The following examples will more fully illustrate the embodiments of the invention. All parts, percenta~es and proportions referred to herein and in the appended claims are by weight unless otherwise indicated.

2~8~230 17 C 7296 (R) Example_l This example demonstrates action of removing soil from glass slides.

5 New glass slides, 5cm x 5cm were machine washed, repeatedly rinsed with demineralised water and soiled with about 55mg baked on egg-yolk per slide.

All washing solutions contained, in 1 litre of 16 French 10 hardness water:

Sodium citrate dihydrate 0.445g Acrylic-maleic copolymer (Sokolan CP5) O.lllg 15 Sodium disilicate monohydrate* 0.445g Potassium coconut soap O.lOOg Sodium sulphate dihydrate 0.950g Calcium sulphate 0.03g * SiO2:Na20 > 2.0 These materials were added to the water and stirred at 45C
for 15 minutes. Some solutions then received:-30mg Savinase 6.OCM (sold as having 1500 GU/mg, analysed as1544 GU/mg) and/or 0.5g alkyl polyglycoside of formula RO(G)x where R = C12-C14 alkyl, G denotes a glucose residue and x has an average value of 1.3.
I'he solutions were maintained at 45C.

After one minute slides were placed in the solution. Slides were removed after varying periods of time, dried and 35 weighed to determine stain removal. The quantity removed was expressed as a percentage of the original stain.

Results were as follows:-2~8~23~
18 C 7296 (R) % Egg-yolk removal Wash TimeNo enzyme Enzyme APGAPG+Enzyme (minutes) No APG only only % % %
5 1 1.7 1.5 0.8 1.2 1.5 ~.0 O.g 1.7 1.9 3.1 0.4 4.4 2.0 4.4 -0.2 15.2 2.4 5.8 0.2 22.4 10 40 2.6 8.1 -0.6 31.3 2.5 12.8 -1.1 48.1 2.6 20.1 -1.4 70.6 These results show synergistic enhancement of stain removal 15 through the use of APG jointly with the proteolytic enzyme, with washing periods of 10 minutes or longer.

Example 2 The procedure was similar to Example 1. All solutions 20 contained, per litre of water:-Sodium citrate dihydrate 0.60g Acrylic maleic copolymer 0.15g Sodium disilicate monohydrate 0.60g Some solutions received 0.5g of alkyl polyglycoside and/or 3Omg of Savinase (both as used in Example 1). Further solutions received 0.5g of C13 to C15 alcohol 3EO
(Synperonic A3) and/or 30mg Savinase. Slides were maintained in the solution at 45C for 60 minutes.

Results were:-Solution contained wt% egg-yolk removal Savinase only 24.3 + 4.5 APG only 0.7 + 0.6 Synperonic A3 only 3.0 + 1.1 APG + Savinase 53.0 + 8.0 40 Synp.A3 + Savinase 26.3 + 14.5 Clearly synergy with APG exceeded synergy (if any~ with Synperonic A3.

20~823~
19 c 7296 (R) Example 3 The procedure was the same as in Example 2. All solutions contained in 1 litre water:-Sodium tripolyphosphate 1.16g Sodium carbonate 0.27g Sodium disilicate hydrate 0.32g Some solutions received 0.5g of alkyl polyglycoside and/or 30mg of Savinase (both as used in Example 1). Furthersolutions received 0.5g of C13 to C15 alcohol 3EO
(Synperonic A3) and/or 30mg Savinase. Slides were maintained in the solution at 45C for 60 minutes.

15 Results were:-Solution contained Egg-yolk removal (wt%) Sa-vi.as~ 15.8 + 6.3 20 APG 3.6 + 1.6 Synperonic A3 5.3 + 2.0 AP5 + Savinase 42.5 + 15.1 A3 + Savinase 14.4 + 1.6 25 Again, APG plus Savinase gave the best soil removal.

Example 4 The procedure was similar to Example 1. Several types of 30 alkyl polyglyc:oside were employed. All solutions contained, per litre of water:-Sodium citrate dihydrate 0.60g Acrylic maleic copolymer 0.15g 35 Sodium disilicate monohydrate 0.60g Alcalase 2.OT 30mg (giving activity 46 GU/ml of solution).
All solutions received 0.5g of alkyl polyglycoside of general formula RO(G)x where G denotes a glucose residue and 40 R is an alkyl chain. The alkyl polyglycoside displayedvarious alkyl chain lengths R and various values of x, the degree of polymerisation.

2~8~30 C 7296 (X) Slides were maintained in the solutions at 45C for 40 minutes. The alkyl polyglycoside eharacteristics and the results obtained were:-5 No of carbon atoms Degree ofwt% egg-yolk in alkyl ehain ~ polymerisation removal 9-11 1.4 86.6 + 4.6 9-11 1.8 79.7 ~ 9.2 12-13 1.8 54.1 + 4.6 14 1.4 43.3 + 5.4 12-14 * 1.3 *58.0 + 5.2 10-12 1.3 86.0 * 4.5 * Same as used in Examples 1 to 3.

15 Example 5 Again the proeedure was similar to Example 1. The detergent active used was ethyl 6-O-decanoyl glucoside whieh has the formula o 9H19C ~o O~l All solutions eontained, per litre of water:-35 Sodium eitrate dihydrate 0.60g Aerylie maleie eopolymer 0.15g Sodium disilicate monohydrate 0.60g Some solutions also contained:-30mg Alcalase 2.0T (giving an activity of 46 GU/ml) and/or 0.5g ethyl 6-O-decanoyl glucoside The solutions were used to wash glass slides stained with 45 egg-yolk as in Example 1, or stainless steel slides stained with egg-yolk in the same way.

2~8~23~
21 C 7296 (R) Slides were maintained in the solutions at 45C, removed after varying periods of time, dried and weighed to assess stain removal, as in Example 1.

5 Results were as follows:-% Egg yolk removal from glass Wash time enzyme only Glucoside Enzyme (minutes) only + glucoside 10 10 4 + l - 2 + 1 4 + 1 9 + O O + 1 17 + 8 15 + 1 1 + 1 34 ~ 11 27 + 3 1 ~ 1 53 + 17 % Egg yolk removal from stainless steel Wash time enzyme onlyGlucoside Enzyme (minutes) only + glucoside 4 + 0 2 + 0 4 + O
20 20 8 + 1 _ ~ L ~
16 + 1 2 + 1 34 -~ 7 25 -~ 4 2 + 0 54 + 11 The use of enzyme and glucoside together is thus seen to 25 give a synergistic enhancement of stain removal.

Exam~le 6 A machine dishwashing formulation was a mixture containing:
Amount by Percent by weight wei~ht Na-citrate dihydrate 2.67g 18.5%
Acrylic-maleic copolymer (Sokolan CP5) 0.67g 4.6%
Na-disilicate monohydrate 2.67g 18.5%
35 Oleic acid 3.44g 23.8%
Ca-stearate 0.30g 2.1%
Petroleum j211y 1. 20g 8.3%
APG 3.00g 20.7%
Savinase 6.OCM (1544 GU/mg) 0.30g 2.1%
40 Termamyl 60T (4.8MU/mg)0.20g 1.4%
The alkyl polyglycoside was of the formula RO(G)x where G
denotes glucose, R is a C12-C14 alkyl chain and x averages 1.8. This formulation was used to wash various stained glass 45 slides using a ~osch S510 automatic dishwasher on its standard program and without salt added to the machine. The ~$~3~
22 C 7296 (R) main wash temperature was 55C, the final rinse temperature was 65C. The water used tap water of 16 French Hardness.

The glass slides were stained with potato, a custard pudding or egg yolk. The potato and custard pudding stains were aged at 30C and 60~ relative humidity for 16-24 hours. The egg yolk stain was baked-on at 120C for two hours. Removal of the stain was determined as loss in weight.

10 The extent of stain removal was:
Potato 99-7 Custard pudding 92.1 Egg yolk 54.0 Example 7 This example demonstrates synergistic action in removing soil Lrom glass Sll~tS.

20 New glass slides, 5cm x 5cm were machine washed, repeatedly rinsed with demineralised water and soiled with about 55mg baked on egg-yolk per slide.

All washing solutions contained, in 1 litre of 16 French 25 hardness water:-Sodium citrate dihydrate 0.6 g Acrylic-maleic copolymer (Sokolan CP5) 0.15 g 30 Sodium disilicate monohydrate 0.6 g These materials were added to the water and stirred at 45C
for 15 minutes. The solutions then received:-20mg Alcalase 2.OT (providing 30GU/ml in solution)and/or 0.25g sodium dodecyl sulphate (SDS).

208~
23 C 7296 (R) The solutions were maintained at 45C.

After one minute slides were placed in the solution. Slides were removed after varying periods of time, dried and 5 weighed to determine stain removal. The quantity removed was expressed as a percentage of the original stain. In this Example only, when a slide was removed from the washing solution it was replaced with a similarly soiled slide which had received identical treatment in a second, identical wash solution.

Results were as follows:-wt% Egg-yolk removal 15 Wash Time Enzyme SDS SDS+Enzyme (minutes) only only % % %
1.3 -1.1 0.0 2.3 -1.0 6.5 20 30 2.1 -1.2 13.5 3.0 -3.3 23.8 These results show synergistic enhancement of stain removal through the use of SDS -jointly with the proteolytic enzyme, 25 with washing periods of 20 minutes or longer.

Example 8 Example 7 was repeated, using a larger amount of enzyme and a larger amount of a different anionic surfactant. When 2~882~
24 C 7296 (R) slides were removed from the wash solution they were replaced with a clean slide. In consequence the washing solutions received:

30mg Alcalase 2.0T (providing 45 GU/ml in solution) and/or 0.5g of Texin ES68 which is a fatty acid ester sulphonate of formula S03Na in which R2 is derived from tallow and so is predominantly C16 and C18 alkyl and R3 is methyl.

The results were:
wt% Egg-yolk removal Wash TimeEnzyme FAES FAES+Enzyme (minutes) only only The synergistic improvement when using FAES and enzyme together is apparent.

When this experiment was repeated using stainless steel slides the results were almost identical.

Example 9 30 The procedure of Example 7 was repeated using SDS, and ~o~3~
c 7296 (R) mixtures of SDS with equal weights of other surfactants. For each test the same total amount of surfactant (250mg/l) was used, and 2Omg/l of Alcalase 2.OT was present.

5 The results, expressed as wt% egg-yolk removal after 30 minutes were:

Surfactant wt% egg-yolk removal SDS 66 + 13 10 SDS + Dobanol 91-6 69 + 11 SDS + Synperonic A7 53 + 9 SDS + APG 300 59 + 15 Dobanol 91-6 is an ethoxylated fatty alcohol where the fatty 15 alcohol has chain length 9 to 11 carbon atoms and the average degree of ethoxylation is 6. It has an HLB value of 12.5 Synperonic A7 is an ethoxylated fatty alcohol where the fatty alcohol has chain length 13 to 15 carbon atoms and the average number of ethylene oxide residues is 7. It has an HLB value of 12.2.

APG 300 is an alkyl polyglycoside of formula R50(G)~
where R5 is alkyl of 9 to 11 carbon atoms and x has average value of 1.4.

26 C 7296 (R) Example 10 Example 7 was repeated using each of three nonionic surfactants in place of SDS. The results, expressed as wt%
egg-yol~ removal after 30 minutes, were:

wt% egg-yolk removal Synperonic A3 + enzyme 15 + 3 Synperonic A7 + enzyme 33 + 6 Dobanol 91-6 + enzyme 53 + lO

Synperonic A3 is C13-C15 fatty alcohol ethoxylated with an average of 3 ethylene oxide residues. It has HLB value 7.9.
Synperonlc A~ lS, as mentioned in the last example, C13-C15 alcohol with an average of 7 ethylene oxide residues. HLB
15 value is 12.2.
Dobanol 91-6 is a Cg-Cll alcohol with an average of 6 ethylene oxide residues. HLB value is 12.5.

It can be seen that this nonionic, used alone, was much 20 superior to Synperonic A7, used alone.

Example 11 Example 7 was repeated twice using a larger amount of enzyme (as in Example 8) and two ethoxylated nonionic surfactants.
In consequence the washing solutions received:

30mg A].calase 2.0T (providing 45 GU/ml in solution) and/or 0.4g of either Synperonic A7 or Dobanol 91-6.

2~23~

27 C 7296 (R) Results, expressed as wt% egg-yolk removal after 30 minutes, were:

wt% egg-yolk removal 5 Synperonic A7 Dobanol 91-6 enzyme only18.9 + 6.0 17.1 + 4.1 surfactant only8.4 + 2.7 7.4 + 5.2 surfactant + enzyme46.5 + 7.3 70.5 + 7.5 10 This confirms the greater synergy wlth Dobanol 91-6.

Example 12 Example 7 was repeated using a larger amount o~ enzyl~le ~a~
in Examples 8 and 11~ and two anionic surfactants. In consequence the washing solutions received:

30mg Alcalase 2.0T (providing ~5 GU/ml in solution) and/or 250mg of either Empicol LX or 250 mg/litre of either sodium lauryl ether s,ulphate (LES) with average 3 ethylene oxide 20 residues, or middle cut coconut alkyl sulphate (Empicol LX).

Results, expressed as wt% egg-yolk removal after 30 minutes, were:
wt% egg-yolk removal 25 enzyme only 3 7 + 0.4 Empicol LX only-2.0 + 0.2 Empicol LX -~ enzyme35.2 + 2.5 LES only 0.1 + 0.7 LES + enzyme31.2 + 2.6 2~8~23~

28 C 7296 (R) ,Example 13 Several machine dishwashing formulations were prepared. Each was a mixture containing:

Amount by weight Na-citrate dihydrate 3.0g Acrylic-maleic copolymer (Sokolan CP5) 0.75g Na-disilicate monohydrate 3.0g 10 Sodium perborate monohydrate 1.16g TAED granules (80% active) 0.72g Oleic acid 0.20g Alcalase 2.0T (23GU/m~! n.o75g Termamyl 6.0 CM 0.20g Termamyl is an amylase.

The formulations contained sodium dodecyl sulphate in amounts which were 0.75g, 1.5g and 3.0g.

Each formulat:ion was used to wash various stained glass slides using a Bosch S510 automatic dishwasher on its standard program and without salt added to the machine. The main wash temperature was 55C, the final rinse temperature 25 was 65C. The water used was tap water of 16 French Hardness.

The materials from which the various slides were made, the stains on them and the extent of removal are set out in the 2Q~8230 29 C 7296 (R) following table. In most instances the extent of removal was determined by weight loss. In a few instances the extent of removal was determined by visual inspection of the area which remains covered by the stain.

In addition the pressure delivered by the pump of the machine was monitored. This is a measure of the effectiveness of the defoamer, in that foaming leads to loss of pump pressure.

The results are set out in the following table. All of the wash solutions formed in the machine had a pH of 9.5.

Stain Slide wt% egq-yolk removal 0.75g SDS1.50g SDS3.00~ SDS

egg-yolk stainless steel 92 + 9100 + 1 99 + 2 egg-yolk porcelain 92 + 10 95 + 0100 ~ 0 custard pudding stainless steel 60 + 2633 + 10 38 + 16 custard pudding porcelain82 + 13 73 + 1278 + 14 potato stainless steel * 97 + 4 100 + 1 100 + 0 potato porcelain * 85 + 11 86 + 1093 + 10 25 spinach porcelain * 100 + 0100 + 0100 + 0 Average pump pressure 90% 79% 70%

* denotes visual score 2~230 ~ 7296 (R) Example 14 A composition containing Dehypon KE 2429 foam inhibitor (believed to be a mixture of branched chain alcohol and ketone according to EP-A-324,339) was used to wash a stainless steel plate 20cm x 6cm with almost 0.8g baked-on egg-yolk, in a Bosch 5510 machine. The wash conditions were the same as for Example 12. The composition contained:

Sodium citrate dihydrate 5.0g Sodium dodecyl sulphate 1.25g Alcalase 2.0T 0.20g Dehypon KE2429 0.50g Removal of soil, determined as loss in weight, was 83%.
15 Average pump pressure was 73~ of pressure achieved with water only and no load in the machine.

Example 15 Example 14 was repeated while also including 0.50g oleic 20 acid in the composition.

Removal of soil, determined as loss in weight, was 91%.
Average pump pressure was 100% of the pressure achieved with water only and no load in the machine.

Exam~le 16 Several machine dishwashing formulations were prepared. Each was a mixture containing:

208~3~
31 C 7296 (R) Amount by weight Na-citrate dihydrate 3.0g Acrylic-maleic copolymer (Sokolan CP5) 0.75g 5 Na-disilicate monohydrate 3.0g Sodium dodecyl sulphate 2.5g Oleic acid 0.17g Ca-stearate/wax mixture 0.08g Termamyl 6.OCM 0.20g Various proteases were includes in these formulations which were then used to wash porcelain and stainless steel slides stained with baked-on egg-yolk. The r~clllts, which are determined by loss in weight, are set out in the following 15 table.

Activity in Proteasesolution wt% egg-yolk removal steel porcelaln 20 Savinase 6.OCM 45GU/ml 68~ 8 66+ 9 Esperase 2.0T 40GU/ml 70+11 74+15 Alcalase CMl.5 45GU/ml 90+ 6 91+ 6 All of the active/protease combinations are compatible with amylases.

Claims (15)

1. A chlorine bleach-free aqueous liquid machine dishwashing detergent composition comprising:

(a) from 0.0002 to 0.05 Anson units per gram of the composition of a proteolytic enzyme;

(b) from 5 to 90% by weight of a detergency builder.

(c) from 1 to 40% by weight of sodium or potassium silicate having SiO2:Na2O or SiO2:K2O ratio of from about 2.0 to about 3.2.

(d) from 3 to 50% by weight of an organic surfactant selected from the group of:

(i) glycoside surfactants;
(ii) anionic surfactants with a hydrophilic head group which is, or which contains a sulphate or sulphonate group and a hydrophobic portion which is or which contains an alkyl or alkenyl group of 8 to 22 carbon atoms;
(iii) ethoxylated fatty alcohols of formula RO(cH2cH2O)nM
where R is an alkyl group of 6 to 16 carbon atoms and n has an average value which is at least four and is sufficiently high that the HLB value of the ethoxylated fatty alcohol is C 7296 (R) 10.5 or greater, with the proviso that if ethoxylated fatty alcohol (iii) is used without anionic surfactant (ii) the majority of its alkyl groups R contain 6 to 12 carbon atoms; and (IV) mixtures thereof.

(e) water, said composition having pH of 7-11, if added to deionised water at a concentration of 2 g/l.

2. A composition according to claim 1 wherein the glycoside surfactant is of general formula in which G is a residue of a pentose or hexose, R'O is an alkoxy group, x is at least unity and R is an organic hydrophobic group containing from 6 to 20 carbon atoms.

3. A composition according to claim 2, wherein R is alkyl or alkenyl of 7 to 16 carbon atoms and x has a value in the range from 1 to 1.8.

4. A composition according to claim 1 wherein the anionic surfactant is selected from:
primary alkyl sulphate of formula R1OSO3,M

C 7296 (R) where R1 is a primary alkyl group of 8 to 18 carbon atoms and M is a solubilising cation, fatty acid ester sulphonate of formula where R2 is an alkyl group of 6 to 16 carbon atoms, R3 is an alkyl group of 1 to 4 carbon atoms and M is a solubilising cation, alkyl benzene sulphonate of formula where R4 is an alkyl group of 10 to 16 carbon atoms and M is a solubilising cation, alkyl ether sulphate of formula R1O(CH2CH2O)nSO3M
where R1 is a primary alkyl group of 8 to 18 carbon atoms, n has an average value in the range from 1 to 6 and M is a solubilising cation.

5. A composition according to claim 1, which comprises from 5-25% by weight of an said sodium or potassium silicate.

6. A composition according to claim 1, which comprises sodium silicate having SiO2:Na2O ratio of at least 2.4.

7. A composition according to claim 1, wherein the total C 7296 (R) quantity of surfactant is from 5 to 25% by weight.

8. A composition according to claim 1, further including a peroxygen bleach.

9. A composition according to claim 1, further including a defoamer other than a nonionic surfactant.

10. A composition according to claim 1, further including amylase and/or lipase.

11. A composition according to claim 1, having a pH of from 9.0 to 9.5

12. A composition according to claim 1, wherein said detergency builder is a non-phosphate builder.

13. A method of washing crockery and/or glassware comprising exposing the crockery and/or glassware to a mixture of water and a detergent composition according to any one of the preceding claims.

14. Use of 3 to 50% by weight of the composition of an organic surfactant as defined in claim 1 as booster for protein soil removal in a machine dishwashing composition containing a proteolytic enzyme and a detergency builder.

15. A composition as claimed in claim 1 and substantially as described herein.