WO2000034423A1

WO2000034423A1 - Detergent compositions

Info

Publication number: WO2000034423A1
Application number: PCT/EP1999/009181
Authority: WO
Inventors: Winston Anthony Pereira; Meena Rajan
Original assignee: Unilever Plc; Unilever Nv; Hindustan Lever Limited
Priority date: 1998-12-10
Filing date: 1999-11-24
Publication date: 2000-06-15
Also published as: AU1557200A; AR021598A1

Abstract

In detergent compositions suitable for cleaning fabrics or hard surfaces, containing a cationic disinfectant compound, the antimicrobial activity of the cationic disinfectant compound is maintained in the presence of anionic surfactant if an anionic polymer is also present. Preferred polymers are anionic cellulosic polymers such as sodium carboxymethyl cellulose, or acrylic/maleic copolymers. Preferred cationic disinfectants are quaternary ammonium compounds such as benzalkonium chloride.

Description

DETERGENT COMPOSITIONS

TECHNICAL FIELD

The invention relates to a synergistic detergent composition for cleaning fabric or hard surfaces, which provides excellent detergency and superior hygiene benefits.

BACKGROUND AND PRIOR ART

Fabric washing detergent compositions contain, as a principal constituent, a surfactant system whose role is to assist in removal of soil from the fabric and its suspension in the wash liquor. The surface active agents used in detergent compositions are generally chosen from anionic, non-ionic, cationic, amphoteric or zwitterionic compounds. Other important components of the detergent formulation are builders, electrolytes, structurants, fillers and minor ingredients like optical brighteners, bleaches, enzymes, speciality polymers, colour and perfume.

Commercial hard surface cleaning detergent compositions typically comprise, one or more surfactants and certain types of such detergent compositions also comprise an abrasive dispersed in. Combinations of these together with electrolytes are generally used to form a suspending system as is well known in the art. Detergent compositions for both fabric and hard surface cleaning are formulated in different forms such as powders, bars, liquids, pastes and gels.

Certain cationic disinfectants have also been incorporated into detergent formulations for use in cleaning fabric or hard surfaces to give a hygiene benefit to the surface in addition to cleaning. However when an anionic surfactant and a cationic compound are present together in the formulation, they would interact to form a complex and hence reduce the antibacterial effect . Prior art discloses various attempts made to prevent such interactions where the cationic material is coated with a high molecular weight nonionic surfactant or a pH sensitive polymer or loading the cationic compound in excess. The coating process has not been considered suitable as it reduces the efficacy of the compound and overdosing is not opted for obvious economic reasons .

US 5 739 168 (Kao) discloses that the presence of a metal chelating compound in the detergent formulation prevents the interaction of the cationic disinfectant with the anionic surfactant .

It has now been found that incorporating an anionic polymer to the detergent formulation comprising an anionic surfactant and a cationic disinfectant enables the cationic component to be active even in presence of the anionic surfactant. This ensures superior soil removal and hygiene benefits to the substrate washed in such compositions. Further, it has been now found that during the manufacture of the detergent, by incorporating the cationic disinfectant after blending the anionic surfactant with the builder and other components, it is possible to obtain a detergent formulation where the activity of the cationic is not affected by the anionic surfactant.

DEFINITION OF THE INVENTION

According to the present invention there is provided a synergistic detergent composition comprising:

(i) from 0.01 to 2 wt% of a cationic disinfectant compound,

(ii) from 5 to 40 wt% of surfactant of which at least 10% is anionic,

(iii) from 0.1 to 5 wt% of an anionic polymer,

and other conventional ingredients to 100 wt%.

DETAILED DESCRIPTION OF THE INVENTION

In the context of the present invention the composition relates to products in the form of powder or granules, tablets, bars, liquids, pastes or gels. Cationic Disinfectant Compounds

Examples of cationic disinfectants useful in the present invention include quaternary ammonium compounds of the general formula

R₄

where Ri and R₂ are linear or branched alkyl, alkenyl or hydroxyalkyl chains having from 8 to 12 carbon atoms, R₃ and R₄ are lower alkyl groups containing from 1 to 4 carbon atoms, wherein R₂ or R₄ can optionally be an aryl or aralkyl group substituted with a halogen atom or alkyl group, and and X is a monovalent anion, preferably a halide ion.

Examples of the above cationic disinfectant compounds are benzalkonium chloride, didecyl methyl benzyl ammonium chloride, didecyl dimethyl ammonium chloride, didecyl methyl propyl ammonium chloride and numerous other such compounds. The cationic compounds can be used either singly or in combination with one another.

Anionic polymers

Anionic polymers useful in this invention include the following: alkali metal, preferably sodium, salts of substituted cellulose compounds, for example, sodium carboxymethylcellulose; or

- homo- and copolymers of unsaturated carboxylic acids, for example, acrylic acid, maleic acid and copolymers thereof, especially acrylic/maleic copolymers.

The polymers can be used either singly or in combination with one another.

Surfactants

The composition according to the invention comprise detergent actives which are generally chosen from anionic, nonionic, cationic, amphoteric and zwitterionic detergent actives or mixtures thereof. In compositions according to the invention 10% of the total surfactant is essentially selected from anionic surfactants.

Suitable anionic detergent active compounds are water soluble salts of organic sulphuric reaction products having in the molecular structure an alkyl radical containing from 8 to 22 carbon atoms, and a radical chosen from sulphonic acid or sulphur acid ester radicals and mixtures thereof.

Examples of suitable anionic detergents are sodium and potassium alcohol sulphates, especially those obtained by sulphating the higher alcohols produced by reducing the glycerides of tallow or coconut oil; sodium and potassium alkyl benzene sulphonates such as those in which the alkyl group contains from 9 to 15 carbon atoms ; sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow and coconut oil ; sodium coconut oil fatty acid monoglyceride sulphates ; sodium and potassium salts of sulphuric acid esters of the reaction product of one mole of a higher fatty alcohol and from 1 to 6 moles of ethylene oxide ; sodium and potassium salts of alkyl phenol ethylene oxide ether sulphate with from 1 to 8 units of ethylene oxide per molecule and in which the alkyl radicals contain from 4 to 14 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralised with sodium hydroxide where, for example, the fatty acids are derived from coconut oil and mixtures thereof.

The preferred water-soluble synthetic anionic detergent active compounds are the alkali metal (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium) salts of higher alkyl -benzene sulphonates and mixtures with olefin sulphonates and higher alkyl sulphates, and the higher fatty acid monoglyceride sulphates . The most preferred anionic detergent active compounds are higher alkyl aromatic sulphonates such as higher alkyl -benzene sulphonates containing from 6 to 20 carbon atoms in the alkyl group in a straight or branched chain, particular examples of which are sodium salts of higher alkyl- benzene sulphonates or of higher-alkyl -toluene, xylene or phenol sulphonates, alkyl-naphthalene sulphonates, ammonium diamyl- naphthalene sulphonate, and sodium dinonyl -naphthalene sulphonate . Suitable nonionic detergent active compounds can be broadly described as compounds produced by the condensation of alkylene oxide groups, which are hydrophilic in nature, with an organic hydrophobic compound which may 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 degree of balance between hydrophilic and hydrophobic elements.

Particular examples include the condensation product of aliphatic alcohols having from 8 to 22 carbon atoms in either straight or branched chain configuration with ethylene oxide, such as a coconut oil fatty alcohol ethylene oxide condensate having from 2 to 15 moles of ethylene oxide per mole of coconut alcohol; condensates of alkylphenols whose alkyl group contains from 6 to 12 carbon atoms with 5 to 25 moles of ethylene oxide per mole of alkylphenol ; condensates of the reaction product of ethylenediamine and propylene oxide with ethylene oxide, the condensate containing from 40 to 80% of polyethyleneoxy radicals by weight and having a molecular weight of from 5,000 to 11,000; tertiary amine oxides of structure R₃N0, where one group R is an alkyl group of 8 to 18 carbon atoms and the others are each methyl, ethyl or hydroxyethyl groups, for instance dimethyldodecylamine oxide; tertiary phosphine oxides of structure R₃P0, where one group R is an alkyl group of from 10 to 18 carbon atoms, and the others are each alkyl or hydroxyalkyl groups of 1 to 3 carbon atoms, for instance dimethyldodecylphosphine oxide; and dialkyl sulphoxides of structure R₂S0 where the group R is an alkyl group of from 10 to 18 carbon atoms and the other is methyl or ethyl, for instance methyltetradecyl sulphoxide; fatty acid alkylolamides ; alkylene oxide condensates of fatty acid alkylolamides and alkyl mercaptans .

Suitable amphoteric detergent active compounds that can be employed are derivatives of aliphatic secondary and tertiary amines containing an alkyl group of 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilizing group, for instance sodium 3- dodecylamino-propionate, sodium 3-dodecylaminopropane sulphonate and sodium N-2-hydroxydodecyl-N-methyltaurate .

Suitable cationic detergent active compounds are quaternary ammonium salts having an aliphatic radical of from 8 to 18 carbon atoms, for instance cetyltrimethyl ammonium bromide.

Suitable zwitterionic detergent active compounds that can be employed are derivatives of aliphatic quaternary ammonium, sulphonium and phosphonium compounds having an aliphatic radical of from 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilising group, for instance 3- (N-N-dimethyl-N-hexadecylammonium) propane-1- sulphonate betaine, 3- (dodecylmethyl sulphonium) propane-1- sulphonate betaine and 3- (cetylmethylphosphonium) ethane sulphonate betaine.

Further examples of suitable detergent active compounds are compounds commonly used as surface-active agents given in the well-known textbooks "Surface Active Agents", Volume I by Schwartz and Perry and "Surface Active Agents and Detergents", Volume II by Schwartz, Perry and Berch.

The total amount of detergent active comprises at least 10% by weight of anionic detergent active. Preferably the anionic detergent active consists primarily or entirely of the sulphate or sulphonate salts discussed above, although a smaller amount of other anionics may be present as well. If so desired, the total amount of detergent active may consist entirely of anionic surfactant.

Builders

The compositions according to the invention preferably comprise a detergency builder. Detergency builders used in the composition are preferably inorganic, and suitable builders include, for example, alkali metal aluminosilicates (zeolites) , sodium carbonate, sodium tripolyphosphate (STPP) , tetrasodium pyrophosphate (TSPP), and combinations of these. Builders are suitably used in an amount of up to 60 wt%, preferably from 1 to 50 wt%, more preferably from 1 to 40 wt%.

Accordingly a preferred aspect of the invention is a synergistic detergent composition comprising:

(i) 0.01 to 2 wt% of a quaternary ammonium compound,

(ii) from 5 to 40 wt% of surfactant of which at least 10% is anionic, (iii) from 0.1 to 5 wt% of anionic polymer,

(iv) from 0 to 60wt% of a calcium binding builder.

Abrasives

A particulate abrasive phase is an ingredient of many hard surface cleaning compositions and may suitably be incorporated in the compositions of the invention.

Preferably, the particulate phase comprises a particulate abrasive which is insoluble in water. In the alternative, the abrasive may be soluble and present in such excess to any water present in the composition that the solubility of the abrasive in the aqueous phase is exceeded and consequently solid abrasive exists in the composition.

Suitable abrasives can be selected from particulate zeolites, calcites, dolomites, feldspars, silicas, silicates, other carbonates, aluminas, bicarbonates, borates, sulphates and polymeric materials such as polyethylene .

Preferred levels of abrasive range from 4 to 95 wt% on product, preferably in the range of from 20 to 40 wt%. The physical form of the product will be influenced by the level of abrasive present.

The most preferred abrasives are calcium carbonate (as Calcite) , mixtures of calcium and magnesium carbonates (as dolomite) , sodium hydrogen carbonate, potassium sulphate, zeolite, alumina, hydrated alumina, feldspars, talc and silica.

Calcite, feldspar and dolomite and mixtures thereof are particularly preferred due to their low cost, suitable hardness and colour.

Other Ingredients

Other ingredients such as solvents, perfumes, colouring agents, fluorescers, enzymes can also be used in the compositions according to the invention, for example, in a total amount of up to 10 wt%.

Fillers

If the composition according to the invention has the form of a detergent bar it will preferably contain some insoluble filler. Fillers suitable for use in a bar composition include kaolin, calcium carbonate (calcite) , talc, soapstone, china clay, calcite, dolomite and the like, used singly or in combination, suitably in an amount ranging from 10 to 75 wt%, preferably from 30 to 70 wt%.

In the case of detergent powders, fillers may also be present, but are predominantly soluble materials like sodium chloride and sodium sulphate . Rheology and Structuring Agents

As described above the compositions of the invention can also be in the form of liquids, pastes or gels. Suitable rheological control agents can be present especially when the compositions contain significant amounts of water or low viscosity surfactants.

The invention will now be illustrated with reference to the following non-limiting Examples, in which parts and percentages are by weight unless otherwise stated.

EXAMPLES

Detergent compositions

Table 1 shows two detergent powder compositions. Example A is a control, while Example 1 is a composition according to the invention wherein a cationic disinfectant is active, even in presence of an anionic surfactant .

Table 1

*Sodium carboxymethylcellulose

** Acrylic/maleic copolymer Sokalan (Trade Mark) CP5 ex BASF

The compositions were subjected to a microbiological test as described below. Microbiological Test

Desized cotton fabric swatches were first loaded with a specified concentration of micro-organisms commonly found on soiled fabric (overnight cultures of S . aeureus, E. coli , P. aeruginosa and B . cereus spores) . The swatches were then subjected to a soak and wash protocol at ambient temperature (~30°C) using the control and detergent formulation according to the invention. In both cases the detergent concentration was 4g/L. The washed swatches were subjected to vigorous agitation in a maceration process in order to mechanically remove the residual microbes from the fabric into the macerate liquor. A quenching agent was added to the macerate liquor to quench any residual antibacterial activity. The macerate liquor was then processed for bacterial counts .

Table 2

The data presented in Table 2 show that the cationic disinfectant reduced significantly the level of the microorganisms present on the fabric after washing even in presence of the anionic surfactant.

Claims

1 A detergent composition comprising:

(i) from 0.01 to 2 wt% of a cationic disinfectant compound,

(ii) from 5 to 40 wt% of surfactant of which at least 10% is anionic,

(iii) from 0.1 to 5 wt% of an anionic polymer,

and other conventional ingredients to 100 wt%.

2 A detergent composition as claimed in claim 1, characterised in that the cationic disinfectant compound is a quaternary ammonium compound.

3 A detergent composition as claimed in claim 2, characterised in that the cationic disinfectant compound is a quaternary ammonium compound of the general formula

where Ri and R₂ are linear or branched alkyl, alkenyl or hydroxyalkyl chains having from 8 to 12 carbon atoms, R₃ and R₄ are lower alkyl groups containing from 1 to 4 carbon atoms, and X is a halide, characterised in that R₂ or R₄ can optionally be an aryl or aralkyl group substituted with a halogen atom or alkyl group.

4 A detergent composition as claimed in claim 3, characterised in that the cationic disinfectant compound is selected from benzalkonium chloride, didecyl methyl benzyl ammonium chloride, didecyl dimethyl ammonium chloride and didecyl methyl propyl ammonium chloride.

5 A detergent composition as claimed in any preceding claim, characterised in that the anionic polymer is an alkali metal salt of a substituted cellulose compound. 6 A detergent composition as claimed in claim 5, characterised in that the polymer is sodium carboxymethylcellulose .

7 A detergent composition as claimed in any one of claims 1 to 4 , characterised in that the polymer is a homo- or copolymer of an unsaturated carboxylic acid.

8 A detergent composition as claimed in claim 7, wherien the polymer is a homo- or copolymer of acrylic or maleic acid.

9 A detergent composition as claimed in any preceding claim, which further comprises from 0 to 60 wt%, preferably from 1 to 50 wt%, more preferably from 1 to 40 wt%, of detergency builder.

10 A detergent composition as claimed in any preceding claim, in the form of a powder, a tablet, a bar, a liquid or a gel.