WO1999025800A1

WO1999025800A1 - Antibacterial liquid dishwashing detergent compositions

Info

Publication number: WO1999025800A1
Application number: PCT/IB1998/001805
Authority: WO
Inventors: Jean-François Bodet; Michael Jakob Reynen
Original assignee: The Procter & Gamble Company
Priority date: 1997-11-17
Filing date: 1998-11-13
Publication date: 1999-05-27
Also published as: JP2001523755A; AR017410A1; EP1032630A1; EP0916720A1; AU9756998A

Abstract

Liquid dishwashing compositions are disclosed, which have antibacterial properties. The compositions comprise a surfactant, a hydrotope, an unsaturated aliphatic terpene alcohol or a derivative thereof, and an amphiphilic polymer having a hydrophobic and a hydrophilic portion.

Description

ANTIBACTERIAL LIQUID DISHWASHING DETERGENT COMPOSITIONS

Technical Field

The invention relates to liquid dishwashing detergent compositions. The compositions have antibacterial properties.

Background

Liquid dishwashing compositions are much desired by consumers and can be used neat or diluted. In diluted mode, a composition is diluted in water to foim a wash liquor in which the dishes to be cleaned are immersed. In neat mode, a composition is directly applied neat onto dishes, and in this mode a dish implement is often use. Specifically, the composition is applied onto the implement, usually a sponge or a dishcloth, which is in turn contacted with the dishes to be cleaned.

A problem arises that dish implements are left humid most of the time, and so they provide a good medium for bacterial growth. The contaminated implement which is used to clean dishes will in turn contaminate those dishes.

We have now found that certain dishwashing compositions can fulfil the further purpose of reducing or eliminating bacterial growth on dish implements.

Summary of the Invention According to a first aspect of the present invention, an aqueous liquid dishwashing composition comprises: a surfactant; a hydrotope; an unsaturated aliphatic terpene alcohol, or derivative thereof; and an amphiphilic polymer having a hydrophobic portion and a hydrophilic portion.

According to a second aspect of the present invention, a method of washing dishes comprises contacting the dishes to be washed with an effective amount of a composition as described above, the composition optionally being in diluted foim.

According to a third aspect of the present invention, the use of an amphiphilic polymer as described above, in a composition comprising a surfactant, a hydrotope and a terpene alcohol, as described above, enhances the anti-bacterial efficacy of that composition. Such polymers may also enhance the anti-bacterial efficiency of other detergent compositions.

Without wishing to be bound by theory, it is believed that the anti-bacterial efficacy of the above-described aqueous liquid dishwashing composition results from synergy between the hydrotope, the teφene alcohol and the amphiphilic polymer. Results are particularly beneficial in compositions comprising less than

25% by weight of the total composition of surfactant, or detergent-active material.

Detailed Description of the Invention

The compositions of the invention are aqueous liquid compositions. They typically comprise from 30% to 90% by weight of the total composition of water, preferably 40% to 85% by weight, more preferably 40 to 70% by weight. Such compositions typically have a viscosity of from 5 cps to 2000 cps, preferably 5 cps to 400 cps, more preferably 5 cps to 350 cps, most preferably 100 to 350 cps, as measured with a Brookfield Viscometer, with a No. 18 spindle, at 20°C. Surfactants

The compositions of the present invention comprise, as an essential ingredient, a surfactant. For instance, one or several of the following surfactants may be used: - Amine oxides according to the formula:

R,

R, - N⁺-O^"

R_*

wherein R₂ represents a straight or branched alkyl or alkenyl group having 10 to 16 carbon atoms, and R₃ and R₄ represent a C, to C₄ hydrocarbon chain, preferably a methyl group or an ethyl group. Generally, when the number of carbon atoms in R₂ is less than 10, the detergency of the composition is lowered, while if it exceeds 16, the stability of the composition at low temperatures deteriorates. Amine oxides are the preferred surfactants. - Alkyl alkoxylated sulfates of the foπnula R,O(A)_nSO₃M, wherein R, is an alkyl or alkenyl group having 9 to 15 carbon atoms, A is an alkoxy group, preferably ethoxy or propoxy, most preferably ethoxy, n represents 0.5 to 7 of real number in average, and M is an alkali metal, alkali earth metal, ammonium or alkanolammonium group. The use of alkyl alkoxylated sulfates with lower values for n, on an equal weight basis, typically when n is below 1.0, improves the performance of the composition with regard to grease removal and sudsing due to the corresponding increase in moles of anionic, but results in an increase in the total amount of unalkoxylated alkyl sulphate, and this seems to make the low temperature instability issue more acute. If different alkyl alkoxylated sulfates are used which have different n values, the resulting average n value of the alkyl alkoxylated sulfate in the composition will be the weighted molar average n value of the individual n values of the different alkyl alkoxylated sulfates used in the composition.

If the average n value is less than 0.5, the stimulus to skin increases and this is not desirable. On the other hand, if the average n value is more than 3, the detergency deteriorates.

If the average number of carbon atoms in R, is less than 9, the detergency tends to be insufficient, while if it is more than 16, the stability at low temperature deteriorates. The suitable alkyl alkoxylated sulfates can be straight chain or branched materials. By branched material, it is meant that R, is branched, while the position of the branching, and the length of the branched group is as determined by the position of the -CH₂OH functional group in the parent alcohol. An increase in the proportion of branched material can improve the physical stability of the composition at low temperature.

In this respect, it is important that the branched alkyl alkoxylated sulfate material should not represent more than 60%, by weight, of the total alkyl alkoxylated sulfate (branched plus linear), otherwise the sudsing performance of the product deteriorates unacceptably. At the other end of the range, there should be enough branched alkyl alkoxylated sulfate to achieve a suitable low temperature stability. This minimum value depends on the specific needs, and can be evaluated by plotting the stability of a given matrix at the desired temperature, as a function of the proportion of branched material. Generally, branched alkyl alkoxylated sulfates should be present in amounts of up to 60%, preferably from 10% to 55%, most preferably 10% to 50%.

Alkyl alkoxylated sulfates are commercially available with a variety of chain lengths, degrees of alkoxylation and degrees of branching under the trade names Empicol® ESA 70 (AE1S) or Empicol® ESB 70 (AE2S) by Albright & Wilson, with C12/14 carbon chain length distribution derived from natural alcohols and are 100% linear, Empimin® KSL68/A (AE1S) and Empimin® KSN70/LA (AE3S) by Albright & Wilson with C12/13 chain length distribution and about 60% branching, Dobanol® 23 ethoxylated sulphates from Shell with C 12/13 chain length distribution and about 18% branching, Lial® 123 ethoxylated sulphates from Condea Augusta with C12/13 chain length distribution and about 60% branching, and Isalchem® 123 alkoxylated sulphates with C 12/13 chain length distribution and about 95%) branching. Also, suitable alkyl alkoxylated sulfates can be prepared by alkoxylating and sulfating the appropriate alcohols, as described in "Surfactants in Consumer Products" by J.Falbe and "Fatty oxo-alcohols: Relation between their all yl chain st.ructure and the performance of the derived AE,AS,AES" submitted to the 4th World Surfactants, Barcelona, 3-7 VI 1996 Congress by Condea Augusta. Commercial oxo-alcohols are a mixture of primary alcohols containing several isomers and homologues. Industrial processes allow one to separate these isomers hence resulting in alcohols with linear isomer content ranging from 5-10% to up to 95%). Examples of available alcohols for alkoxylation and sulfation are Lial® alcohols by Condea Augusta (60% branched), Isalchem® alcohols by Condea Augusta (95% branched), Dobanol® alcohols by Shell (18% linear).

- Alkyl benzene sulfonates in which the alkyl group contains from 9 to 15 carbon atoms, preferably 11 to 40 carbon atoms in straight chain or branched chain configuration. An especially preferred linear alkyl benzene sulfonate contains about 12 carbon atoms. U.S. Pat. Nos. 2,220,099 and 2,477,383 describe these surfactants in detail.

- Alkyl sulfates obtained by sulfating an alcohol having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms. The alkyl sulfates have the formula

ROSO₃ ^"M⁺ where R is the C₈_₂₂ alkyl group and M is a mono- and/or divalent cation.

- Paraffin sulfonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms, in the alkyl moiety. These surfactants are commercially available as Hostapur SAS from Hoechst Celanese. - Olefin sufonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms. U.S. Pat. No. 3,332,880 contains a description of suitable olefin sulfonates.

- Alkyl glyceryl ether sulfonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms, in the alkyl moiety.

- Fatty acid ester sulfonates of the formula: R, - CH(SO₃ M⁺)CO₂R₂ wherein R, is straight or branched alkyl from about C₈ to C₁₈, preferably C_I2 to C₁₆, and R₂ is straight or branched alkyl from about C, to C₆, preferably primarily C„ and M⁺ represents a mono- or divalent cation.

- Secondary alcohol sulfates having 6 to 18, preferably 8 to 16 carbon atoms. Suitable co-surfactants for use in the compositions of the present invention are:

- Fatty acid amide surfactants having the formula:

0 R⁶ - C - N(R⁷),

wherein R⁶ is an alkyl group containing from 7 to 21, preferably from 9 to 17, carbon atoms and each R⁷ is selected from the group consisting of hydrogen, C,-C₄ alkyl, C,-C₄ hydroxyalkyl, and -(C₂H₄O)_xH where x varies from 1 to about 3.

- Polyhydroxy fatty acid amide surfactants having the formula:

O R¹

R² C N In the above formula, R¹ is H, C,-C₄ hydrocarbyl, 2-hydroxyethyl, 2-hydroxypropyl, or a mixture thereof, preferably C,-C₄ alkyl, e.g. methyl, ethyl, propyl, isoproppyl, and butyl, more preferably C, or C₂ alkyl, most preferably C, alkyl (i.e., methyl). R² is a C₅-C₃₁ hydrocarbyl, preferably straight chain C₇-C,₉ alkyl or alkenyl, more preferably straight chain C₉-C₁₇ alkyl or alkenyl, most preferably straight chain C,,-C₁₇ alkyl or alkenyl, or mixtures thereof. For instance, R²-CO-N< can be, for example, cocamide, stearamide, oleamide, lauramide, myristamide, capricamide, palmitamide, tallowamide, etc. Z is a polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least 3 hydroxyls directly connected to the chain, or an alkoxylated (preferably exhoxylated or propoxylated) derivative thereof. Z is preferably derived from a reducing sugar that has been subject to a reductive amination reaction. Suitable reducing sugars include glucose, fructose, maltose, lactose, galactose, mannose, and xylose. More preferably Z is selected from the group consisting of -CH₂(CHOH)_n. CH₂0H, -CH(CH₂0H)(CHOH)_n., CH₂0H, -CH₂(CHOH)₂(CHOR')-(CHOH)CH₂OH, where n is an integer from 3 to 5, inclusive, and R' is H or a cyclic or aliphatic monosaccharide, or an alkoxylated derivative thereof. Most preferably Z is a glycityl. For instance, Z can be 1-deoxyglucityl, 2-deoxyfructityl, 1-deoxymaltityl, 1-deoxylactityl, 1-deoxygalactityl, 1-deoxymannityl, 1-deoxymaltotriotityl, etc. It is especially preferred that Z is a glycityl having n is 4, particularly - CH₂(CHOH)₄CH₂OH.

- Betaine detergent surfactants having the general formula:

R - W R^l)₂ - R²COO^" wherein R is a hydrophobic group selected from the group consisting of alkyl groups containing from 10 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, alkyl aryl and aryl alkyl groups containing a similar number of carbon atoms with a benzene ring being treated as equivalent to about 2 carbon atoms, and similar structures interrupted by amide or ether linkages; each R¹ is an alkyl group containing from 1 to about 3 carbon atoms; and R² is an alkylene group containing from 1 to about 6 carbon atoms.

- Ethylene oxide condensates, which can be broadly defined as compounds produced by the condensation of ethylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which can be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired balance between hydrophilic and hydrophobic elements.

Examples of such ethylene oxide condensates suitable as suds stabilizers are the condensation products of aliphatic alcohols with ethylene oxide. The alkyl chain of the aliphatic alcohol can either be straight or branched and generally contains from about 8 to about 18, preferably from about 8 to about 14, carbon atoms for best performance as suds stabilizers, the ethylene oxide being present in amounts from about 8 moles to about 30, preferably from about 8 to about 14 moles of ethylene oxide per mole of alcohol.

- Cationic quaternary ammonium surfactants of the formula:

[R'(OR²)J[R³(OR²)J₂R⁴N⁺X

- .Amine surfactants of the formula:

[R'(OR²)_y][R³(OR)_y]R⁴N

wherein R¹ is an alkyl or alkyl benzyl group having from about 6 to about 16 carbon atoms in the alkyl chain; each R² is selected from the group consisting of -CH₂CH₂-, -CH₂CH(CH₃)-, -CH₂CH(CH₂OH)-, -CH₂CH₂CH₂-, and mixtures thereof; each R³ is selected from the group consisting of C C₄ alkyl, C,-C₄ hydroxyalkyl, benzyl, and hydrogen when y is not 0; R⁴ is the same as R³ or is an alkyl chain wherein the total number of carbon atoms of R¹ plus R⁴ is from about 8 to about 16, each y is from about 0 to about 10, and the sum of the y values is from about 0 to about 15; and X is any compatible anion. The compositions of the present invention typically comprise from 10% to

60%) by weight of the total composition of a surfactant, or mixtures thereof, preferably from 10% to 55% by weight, most preferably from 20% to 55% by weight. Hvdrotropes

As a second essential ingredient, the compositions of the present invention comprise a hydrotrope. Suitable hydrotopes include those selected from salts of cumene sulfonate, toluene sulfonate, xylene sulfonate, and benzene sulfonate, and mixtures thereof. Preferred salts are ammonium and sodium salts, especially salts of cumene sulfonate, with sodium cumene sulfonate being most preferred. Other suitable hydrotopes are di-acids, such as glutaric acid, succinic acid, adipic acid, and commercially available di-acids, for instance as supplied by Westvaco, and mixtures thereof.

The compositions of the present invention typically comprise from 1 % to

15%) by weight of the total composition of a hydrotrope, preferably 1% to 10% by weight, preferably 2% to 8% by weight, most preferably 4 to 7% by weight.

Unsaturated Aliphatic Teφene Alcohol or Derivative Thereof As a third essential ingredient, the compositions of the present invention comprise an unsaturated aliphatic teφene alcohol or a derivate thereof (i.e unsaturated aliphatic teφene alcohols where the alcohol group is functionalized, e.g. into acetate, formate, propionate, or the like), or mixtures thereof. Suitable alcohols include geraniol, nerol, citronellol, linalool, citronellyl acetate, geranyl acetate, linalyl acetate, citronellyl foimate, geranyl foπnate, linalyl formate, citronellyl propionate, geranyl propionate, linalyl propionate, and mixtures thereof. Geraniol is preferred.

The compositions of the present invention typically comprise from 0.1% to 3% by weight of the total composition of an unsaturated aliphatic teφene alcohol, preferably 0.2% to 2.5% by weight, more preferably 0.3% to 2% by weight, most preferably 0.4 to 1% by weight.

Amphiphilic Polymer

As a fourth essential ingredient, the compositions of the present invention comprise an amphiphilic polymer, i.e. a polymer comprising both a hydrophobic portion, or group, and a hydrophilic portion, or group. The polymer may be a naturally-occurring polymer; a hydrophobically-modified polymer, by which we mean a polymer which has been modified by incoφoration thereinto of a hydrophobic group; a polymer which has been made by free radical polymerisation; a polymer which has been made by condensation reaction, i.e. a polycondensate; and mixtures thereof.

The polymer may be non-ionic or ionic in nature, and is preferably non-ionic or anionic.

The polymer is preferably water-soluble or water-dispersible, so that it is compatible with the surfactant systems used in the compositions of the present invention. However, polymers which swell in water, for instance due to cross- linking, may also be used. The nature of the hydrophobic portion, or group, included in the amphiphilic polymer will depend upon the nature of the polymer, and the nature of the hydrophilic portion, or group, thereof. Typically, however, the hydrophobic portion, or group, comprises from 1 to 30 carbon atoms, preferably 2 to 30 carbon atoms and more preferably 2 to 20 carbon atoms. Furthermore, typically, the hydrophobic group is selected from straight or branched chain alkyl groups, aryl groups, alkaryl groups, aralkyl groups, and mixtures thereof which are optionally substituted. Preferably, the hydrophobic group is an alkyl group.

Examples of naturally-derived polymers suitable for use in the present invention include cellulose ethers comprising hydrophobic groups, which are typically alkyl groups comprising 1 to 20 carbon atoms, preferably 2 to 10 carbon atoms. Especially preferred polymers are the hydroxyalkyl alkylcelluloses, such as hydroxyethyl methylcellulose (HEMC), hydroxypropyl methylcellulose (HPMC), hydroxybutyl methylcellulose (HBMC), and the corresponding ethyl- and propylcelluloses. Other cellulose derivatives which may be useful in the compositions of the present invention include:

- Quaterized cationic celluloses modified with hydrophobic groups, typically alkyl, alkaryl or aralkyl groups comprising 1 to 30 carbon atoms, preferably 8 to 30 carbons atoms, more preferably 8 to 22 carbon atoms. - Quaterized alkylhydroxy ethylcelluloses.

- Galactomannans comprising hydrophobic groups, for instance as described in EP-A-0281360. - Pullulans modified with hydrophobic groups, for instance cholesterol groups.

- Gelatins modified with hydrophobic groups, for instance C₆-18 alkyl groups. - Mucopolysaccharides, for instance comprising glycosaminoglycan and hyaluronic acid.

The preferred polymers of the free radical-type are vinyl or acrylic polymers and copolymers. Particularly preferred are anionic, acrylic polymers and copolymers, typically provided in aqueous dispersion form and referred to as HASE (hydrophobically-modified alkali-soluble or swellable emulsions). The polymers may be partially cross-linked.

Typically, such polymers are teφolymers formed from a monomer comprising a carboxylic acid group, e.g. acrylic or methacrylic acid, a relatively water-insoluble monomer such as C_M acrylate or methacrylate, and a monomer comprising a hydrophobic group, optionally attached through an ether, ester, polyethoxy, amide, carbamate or urea linkage. Examples of polymers of this type are described in Shay, Surface Coatings International (1993) JJ:446-453, US-A- 4384096, US-A-4421902, US-A-4423199 and US-A-4663385. Suitable commercially-available materials are those of the Acusol (trade mark) range, for instance Acusol 820 and 823, and those of the Acrysol (trade mark) range, both of which are supplied by Rohm & Haas.

Other polymers of the free radical-type that may be useful in the compositions of the present invention include:

- Acrylic acid or methacrylic acid copolymers with N-alkylacrylamides, and in particular copolymers of acrylic acid and N-alkylacrylamides having a C, to C₂₀ alkyl group, such as those described by Magny et al., Double Liaison, (1993) 451 : 52-55.

- Copolymers formed from a monomer comprising a carboxylic acid group, e.g. (meth)acrylic acid, and (meth)acrylate esters or amides comprising hydrophobic groups e.g. cycloaliphatic or aromatic groups, such as isobornyl or adamantyl groups.

- Copolymers formed from perfluoro monomers, e.g. copolymers with perfluorohexyl (meth)acrylate.

- Copolymers formed from a monomer bearing a sulphonic acid group, e.g. 2-acrylamido-2-methyl-2-propanesulphonic acid, styrenesulphonic acid, and an alkyl (meth)acrylamide possessing at least 8 carbons. - Non-ionic acrylic copolymers, and in particular copolymers of acrylamide and N-alkylacrylamides, such as those described by Goodwin et al, Adv. Chem. 223, Am. Chem. Soc, Washington DC, (1989) p.365.

- Copolymers of maleic anhydride and of monomers containing at least one fatty (e.g. C₈.₃₀) alkyl chain, such as N-octadecyl vinyl ether/maleic anhydride copolymers,

- Copolymers of crotonic acid and of monomers containing at least one fatty (e.g. C₈.₃₀) chain, such as vinyl acetate/crotonic acid/vinyl neodecanoate teφolymers, or vinyl acetate/crotonic acid/allyl stearate teφolymers.

- (Meth)acrylic acid polymers modified with groups containing at least one fatty (e.g. C₈.₃₀) chain or copolymers of (meth)acrylic acid and of monomers containing at least one fatty (e.g. C₈.₃₀) chain. Examples include cross-linked copolymers of acrylic acid/C,₀-C₃₀ alkyl acrylate; (meth)acrylic acid/ethyl acrylate/alkyl acrylate copolymers; acrylic acid/vinyl isodecanoate cross-linked copolymers; acrylic acid/vinylpyrrolidone and lauryl methacrylate teφolymers; acrylic acid/lauryl (meth)acrylate copolymers; (meth)acrylic acid allcyl acrylate/polyethoxylated alkyl allyl ether teφolymers; methacrylic acid/ethyl acrylate/poly-ethoxylated stearyl allyl ether teφolymers; methacrylic acid ethyl acrylate/polyoxyethylenated lauryl acrylate teφolymers; methacrylic acid/ethyl acrylate/polyoxy-ethylenated stearyl methacrylate teφolymers; methacrylic acid/ethyl acrylate/polyoxyethylenated nonlyphenyl acrylate copolymers; acrylic acid/polyoxyethylenated stearyl monoitaconate copolymers or acrylic acid/polyoxy- ethylenated cetyl monoitaconate copolymers; methacrylic acid/butyl acrylate/hydrophobic monomer copolymers containing a fatty chain; acrylic acid/C₁₅ alkyl acrylate/polyethylene glycol acrylate teφolymers; salts of a partial fatty acid ester of an acrylic acid dimethylethanolamine copolymer; copolymers of acrylic acid/acrylate/amphiphilic monomer containing a fatty chain with urethane groups; and acrylic polymers modified with hydrophobic groups containing a fatty chain. Suitable polycondensates which may be used in the compositions of the present invention include, for instance, associative polymers, and in particular associative polyurethanes. Such polymers are typically non-ionic, and include sequences of a hydrophilic nature, typically of polyoxyethylene, and sequences of a hydrophobic nature, which may include aliphatic and/or aromatic units. Specific examples of such polymers are described by Zeying Ma, J. Appl. Polymer Sci.,

(1993) 49: 1509-27.

Commercially-available polymers of the types described above are listed in

EP-A-0770380, the contents of which are incoφorated herein by way of reference. The compositions of the present invention typically comprise 0J to 10% by weight, preferably 0.2 to 5% by weight, more preferably 0.5 to 3% by weight, most preferably 0.5 to 2% by weight, of the total composition, of an amphiphilic polymer.

Optional Ingredients The compositions of the present invention can comprise a number of other, optional ingredients, as follows:

Phenolic Compound

A first optional, but preferred, ingredient is a phenolic compound having the formula:

wherein R, R„ R₂, R₃, R₄ are independently H; a linear or branched, saturated or unsaturated hydrocarbon group having from 1 to 20 carbon atoms, preferably from 1 to 10, more preferably from 1 to 4, an alkoxylated hydrocarbon chain according to the formula R_a(A)_n wherein I- , is a linear or branched, saturated or unsaturated hydrocarbon chain having from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, more preferably from 1 to 4 carbon atoms; A is butoxy, propoxy and/or ethoxy, or an aryl chain having from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, more preferably from 1 to 4 carbon atoms, or mixtures thereof; and n is an integer of 1 to 4, preferably from 1 to 3. Highly preferred from that class of ingredients are eugenol and thymol, and mixtures thereof.

The compositions of the present invention can comprise from 0.1% to 4%, preferably from 0.2% to 1.5% by weight of the total composition of such a phenolic compound, or mixtures thereof. Maanesium ions

.Another optional component comprises magnesium ions, which may be added to the liquid detergent compositions of the invention for improved product stability, as well as improved sudsing and skin mildness.

The compositions of the present invention typically comprise from 0% to 2.0%, preferably 0.1% to 1.5%, most preferably from 0.2% to 1%, by weight of the composition, of magnesium ions.

It is preferred that the magnesium ions are introduced by neutralization of the acid form of alkylethoxy surfactants with a magnesium oxide or magnesium hydroxide slurry in water. Normally, this method is limited by the amount of anionic surfactant in the composition. An alternative method is to use MgCl₂, MgSO₄ or other inorganic Mg salts. These materials are less desirable because they can cause corrosivity problems (chloride salts), decrease the solubility of the compositions, or cause formulatibility/stability problems in the compositions. It is desirable for these reasons to limit the addition of inorganic salts to less than 2%, preferably less than 1%, by weight of the anionic inorganic counterion. Anti-qelling polymer .Another optional component comprises an anti-gelling polymer, which improves the compositions' resistance to gelling. Suitable polymers for this puφose have a molecular weight of at least 500, preferably from 500 to 20000, more preferably 1000 to 5000, most preferably 1000 to 3000.

The required amount of anti-gelling polymer can easily be determined by trial and error, but generally, the compositions of the present invention comprise from 0.5%) to 6% by weight of the total composition of an anti-gelling polymer, or mixtures thereof, preferably 0.5% to 4% by weight, most preferably 1.5% to 3% by weight.

Examples of suitable polymers include:

- Polyalkylene glycols, preferably polyethylene glycol and polypropylene glycol - Polyamines, particularly alkoxylated or polyalkoxylated polyamines. Such materials can conveniently be represented as molecules of the empirical structures with repeating units: [N R] n .Amine form

(alkoxy)y and

Rl

[N⁺ R] n nX^" Quatemized form

(alkoxy)y

wherein R is a hydrocarbyl group, usually of 2-6 carbon atoms; R¹ is a C,-C₂₀ hydrocarbon; the alkoxy groups are ethoxy, propoxy, and the like, and y is 2-30, most preferably from 10-20; n is an integer of at least 2, preferably from 2-20, most preferably 3-5; and X^" is an anion such as halide or methylsulfate, resulting from the quaternization reaction.

The most preferred polyamines for use herein are the so-called ethoxylated polyethylene amines, i.e., the polymerized reaction product of ethylene oxide with ethyleneimine, having the general formula:

(EtO) [N CH2 CH2 1 n N (EtO)y

(EtO)y (EtO)y

wherein y = 2-30. Particularly preferred for use herein is an ethoxylated polyethylene amine, in particular ethoxylated tetraethylenepentamme, and quatemized ethoxylated hexamethylene diamine. - Terephthalate-based polymers, particularly those having the formula:

O O O O

X - (OCH₂CH₂)_n — [(-OC-R¹ -CO-R-^-OC-R¹ -CO-R3-)_v — ]

O O

II II

- OC - R - CO - (CH₂CH₂O)_n - X

wherein each R¹ is a 1 ,4-phenylene moiety; R² is a 1 ,2-propylene moiety; R³ is a polyoxyethylene moiety of the formula (CH₂H₂O)_qCH₂CH,-; each X is ethyl or preferably methyl; each n is from about 12 to about 45; q is from about 12 to about

90; the average value of u is from about 5 to about 20; the average value of v is from about 1 to about 10; the average value of u+v is from about 6 to about 30; the ratio u to v is from about 1 to about 6.

Preferred polymers for use herein are polymers of the formula:

O O || II

X -(OCH₂CH₂)_n - (O - C - R¹ - C - OR²)-_u

O O

II II -(O - C - R¹ - C - O)- -(CH₂CH₂O)-_n X

in which X can be any suitable capping group, with each X being selected from the group consisting of H, and alkyl or acyl groups containing from 1 to about 4 carbon atoms, preferably 1 to 2 carbon atoms, most preferably alkyl. Furthermore, the alkyl group may contain anionic, cationic or nonionic substituents such as sulfonate, sulfate, ammonium, hydroxy groups, etc n is selected for water solubility, and has a range of values which generally averages from about 10 to about 50, preferably from about 10 to about 25. There should preferably be very little material, preferably less than about 10 mol %, more preferably less than 5 mol %, most preferably less than 1 mol %, in which u is greater than 5. Furthermore there should preferably be at least 20 mol %, preferably at least 40 mol %, of material in which u ranges from 3 to 5.

The R¹ moieties are essentially 1 ,4-phenylene moieties. As used herein, the term "the R¹ moieties are essentially 1 ,4-phenylene moieties" refers to compounds where the R¹ moieties consist entirely of 1 ,4-phenylene moieties, or are partially substituted with other arylene or alkarylene moieties, alkylene moieties, alkenylene moieties, or mixtures thereof. .Arylene and alkarylene moieties which can be partially substituted for 1 ,4-phenylene include 1,3-phenylene, 1 ,2-phenylene, 1,8-naphthylene, 1 ,4-naphthylene, 2,2-biphenylene, 4,4'-biphenylene and mixtures thereof. Alkylene and alkenylene moieties which can be partially substituted include ethylene, 1,2-propylene, 1 ,4-butylene, 1,5-pentylene, 1 ,6-hexamethylene, 1,7-heptamethylene, 1,8-octamethylene, 1,4-cyclohexylene, and mixtures thereof.

Preferably, the R¹ moieties consist entirely of (i.e., comprise 100%) 1,4- phenylene moieties, i.e. each R¹ moiety is 1 ,4-phenylene.

For the R² moieties, suitable ethylene or substituted ethylene moieties include ethylene, 1,2-propylene, 1,2-butylene, 1 ,2-hexylene,

3-methoxy-l,2-propylene and mixtures thereof. Preferably, the R² moieties are essentially ethylene moieties, or, preferably, 1,2-propylene moieties or mixtures thereof.

Preferably, from about 75% to about 100%, more preferably from about 90% to about 100% of the R² moieties are 1 ,2-proρylene moieties.

The value for n averages at least about 10, but a distribution of n values is present. The value of each n usually ranges from about 10 to about 50. Preferably, the value for each n averages in the range of from about 10 to about 25.

The most preferred polymers are those having the formula:

O O

II II X -(OCH₂CH₂)_n - (O - C - R¹ - C - OR²)-_u

O O -(O - C - R¹ - C - O)- -(CH₂CH₂O)-_n X

wherein X is methyl, n is 16, R¹ is 1,4-phenylene moiety, R² is 1 ,2-propylene moiety and u is essentially between 3 and 5. Solvent

As another optional component, the compositions of the invention can comprise a solvent in an effective amount so as to reach the desired viscosity.

Suitable solvents for use herein include low molecular weight alcohols such as C,-C₁₀, preferably C,-C₄ mono- and dihydric alcohols, preferably ethyl alcohol, isopropyl alcohol, propylene glycol and hexylene glycol.

The compositions of the invention typically comprise from 3% to 20% by weight of the total composition of an alcohol, or mixtures thereof, preferably 3% to 15% by weight, most preferably 5% to 10% by weight.

Preferably, the compositions of the invention are formulated as clear liquid. compositions. By"clear" it is meant isotropic, stable and transparent. In order to achieve isotropic compositions, the use of solvents and hydrotropes is well known to those familiar with the art of dishwashing formulations. Those clear compositions are preferably packaged in transparent containers, which can typically be made out of plastic or glass. In addition to the optional ingredients described hereinbefore, the compositions can contain other optional components suitable for use in liquid dishwashing compositions such as anti-oxidants, perfumes, dyes, pacifiers, enzymes, builders and chelants, and pH buffering means so that the compositions herein generally have a pH of from 5 to 11, preferably 6.0 to 10.0, most preferably 7 to 9, measured at a 10%> solution in water.

Method

In the method aspect of this invention, soiled dishes are contacted with an effective amount, typically from about 0.5 ml. to about 20 ml. (per 25 dishes being treated), preferably from about 3 ml. to about 10 ml, of a detergent composition of the present invention. The actual amount of liquid detergent composition used will be based on the judgement of user, and will typically depend upon factors such as the particular product formulation of the composition, including the concentration of active ingredients in the composition, the number of soiled dishes to be cleaned, the degree of soiling on the dishes, and the like.

The particular product formulation, in turn, will depend upon a number of factors, such as the intended market i.e., U.S., Europe, Japan, etc. In the method herein, the soiled dishes are preferably immersed into a water bath with or without a liquid dishwashing detergent as described herein. A dish implement, i.e. a device suitable for accepting, typically for absorbing, a liquid dishwashing detergent such as a sponge or a dishcloth, is placed directly onto or contacted with a separate quantity of undiluted liquid dishwashing composition as described herein for a period of time typically ranging from about 3 to about 10 seconds. The dish implement, and consequently the undiluted liquid dishwashing composition, is then contacted with the surface of each of the soiled dishes to remove said soiling. The dish implement is typically contacted with each dish surface for a period of time ranging from about 5 to about 30 seconds, although the actual time of application will be dependent upon factors such as the degree of soiling of the dish. The contacting of the dish implement to the dish surface is preferably accompanied by concurrent scrubbing.

After all the soiled dishes have been cleaned, the dish implement is preferably contacted, e.g. soaked, with neat product and left to dry. There is little or no bacterial growth on or in dish implements used with the compositions of the invention, even over extended usage Furthermore, contaminated dish implements (i.e dish implements contaminated by previous uses with other compositions) also recover after one or several uses with the compositions of the present invention. The present invention is now illustrated by way of the following Example: Example

Two aqueous liquid dishwashing compositions were prepared having the following formulations:

Composition 1 Composition 2

Na AE0.6S 12.52 12.52 Amide Oxide 0.83 0.83 Betaine 0.83 0.83 Glucose Amide 0.65 0.65 Nonionic (C10E8) 2.18 2J8

Citric Acid 0.125 0J25

Glutaraldehyde 0.03 0.03

Sodium Cumene

Sulfonate 6 6

Geraniol 0.6 0.6

Acusol 820 1.25 -

Hydroxypropyl methyl- 0.44 cellulose (HPMC)

Sodium Chloride - -

Magnesium Sulphate - -

Sparkle 0.32 0.32

Butylated Hydroxy

Toluene 0.02 0.02

0.5% FD&C Blue No. 1 0.18 0.18

Water to 100% to 100%

Viscosity (cps) 200 200 pH (10% solution) 7.1 7.8

The anti-bacterial activity of the above two compositions was measured using a quantitative suspension test in accordance with European Standard CEN 1276 with 2 minute contact time, utilising the Gram-Negative species Escherichia coli and Pseudomonas aeruginosa. The results obtained were compared with those obtained from a Control composition having the same base formulation as Compositions 1 and 2, but containing neither Acusol 820 nor HPMC. The results are given in Table 1 below, as averages over 12 repetitions done on each composition.

Table 1

The results illustrate that while a combination of sodium cumene sulfonate and geraniol provides significant anti-bacterial activity, this is enhanced by the further addition of a hydrophobically-modified polymer, such as Acusol 820 or HPMC. Preferred variations on Compositions 1 and 2 above are those which include sodium cumene sulfonate in an amount of 5 to 6% by weight, geraniol in an amount of 0.4 to 0.6% by weight, Acusol 820 in an amount of 1 to 1.25% by weight or HPMC in an amount of 0.4 to 0.6%> by weight, and each of sodium chloride and magnesium sulfate in an amount of 0 to 2% by weight, based on the weight of the total composition.

Claims

WHAT IS CLAIMED IS:

1. An aqueous liquid dishwashing composition comprising: a surfactant; a hydrotope; an unsaturated aliphatic te╧åene alcohol, or derivative thereof; and an amphiphilic polymer having a hydrophobic portion and a hydrophilic portion

2. A composition according to claim 1, wherein the polymer is water-soluble, water-dispersible or water-swellable.

3. A composition according to any preceding claim, wherein the polymer is selected from hydrophobically-modified cellulose ethers and derivatives thereof; hydrophobically-modified galactomannans, pullulans and gelatins; mucopolysaccharides; acrylic polymers and copolymers made by free radical polymerisation; vinyl polymers and copolymers made by free radical polymerisation; associative polyurethanes; and mixtures thereof.

4. A composition according to claim 3, wherein the polymer is a hydroxyalkyl alkylcellulose, e.g. hydroxypropyl methylcellulose and hydroxybutyl methyl cellulose.

5. A composition according to claim 3, wherein the polymer is an acrylic polymer or copolymer, e.g. Acusol 820.

6. A composition according to any preceding claim, which comprises 10 to 60%) by weight of the total composition of a surfactant, from 1 to 15% by weight of the total composition of a hydrotope, from 0J to 3% of the total composition of a te╧åene alcohol or derivative thereof, and 0J to 10% by weight of a hydrophobically-modified polymer.

7. A composition according to claim 6, which comprises less than 25% by weight of the total composition of a surfactant.

8. A composition according to any preceding claim, wherein the hydrotope is selected from salts of cumene sulfonate, toluene sulfonate, xylene sulfonate, and benzene sulfonate, and mixtures thereof, preferably an ammonium or a sodium salt, more preferably sodium cumene sulfonate.

9. A composition according to any of claims 1 to 8, wherein the hydrotope is a di-acid.

10. A composition according to any preceding claim, wherein the te╧åene alcohol is geraniol.

11. A composition according to any preceding claim, which further comprises a phenolic compound having the formula

wherein R, RΓÇ₧ R₂, R₃ and R₄ are independently H; a linear or branched, saturated or unsaturated hydrocarbon group having from 1 to 20 carbon atoms, preferably from 1 to 10, more preferably from 1 to 4, an alkoxylated hydrocarbon chain according to the formula R_a(A)_n wherein ^ is a linear or branched, saturated or unsaturated hydrocarbon chain having from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, more preferably from 1 to 4 carbon atoms, A is butoxy, propoxy and/or ethoxy, or an aryl chain having from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, more preferably from 1 to 4 carbon atoms, or mixtures thereof; and n is an integer of 1 to 4, preferably from 1 to 3.

12. A composition according to claim 11, wherein the phenolic compound is selected from eugenol, thymol, and mixtures thereof.

13. A composition according to claim 11 or claim 12, which comprises 0.1% to 4 by weight of the total composition of a phenolic compound.

14. A composition according to any preceding claim, wherein the surfactant comprises an amine oxide.

15. A method of washing dishes comprising contacting the dishes to be washed with an effective amount of a composition as defined in any preceding claim, the composition optionally being in diluted form.

16. A method according to claim 15, which comprises applying the composition to a dishwashing implement, and contacting the dishes to be washed with the implement.

17. Use of a polymer as defined in any of claims 1 to 5, to enhance anti-bacterial efficacy of an aqueous liquid dishwashing composition comprising a surfactant, a hydrotope, and an unsaturated aliphatic te╧åene alcohol or a derivative thereof.

18. Use according to claim 17, wherein the aqueous liquid dishwashing composition comprises less than 25% by weight of the total composition of a surfactant.