WO2000041468A2

WO2000041468A2 - Detergent composition

Info

Publication number: WO2000041468A2
Application number: PCT/EP1999/009056
Authority: WO
Inventors: Devadatta Shivaji Sankholkar; Pullimudaliar Sidheswaran
Original assignee: Hindustan Lever Ltd; Unilever NV
Current assignee: Hindustan Unilever Ltd; Unilever NV
Priority date: 1999-01-15
Filing date: 1999-11-24
Publication date: 2000-07-20
Anticipated expiration: 2001-07-15
Also published as: GB9900954D0; AR021519A1; WO2000041468A3; AU1653700A

Abstract

A solid hand dish wash composition comprising: a cold water soluble, branched hydrocolloid with a viscosity of less than 10,000 mPa.s in water at 1.5 % wt. at 25 °C, and 40 % wt. or less of a detergent active.

Description

DETERGENT COMPOSITION

Technical Field

The invention relates to a solid detergent composition for manual dishwashing.

Background and Prior Art

It is well known that foam volume and foam stability are often used by the consumer to gauge the cleaning efficiency. This is particularly the case when manual -cleaning dishes occurs. It is therefore commercially desirable to formulate a detergent composition with improved foaming performance.

Commercial hard surface cleaning compositions typically comprise one or more surfactants and a plurality of abrasives dispersed in. Combinations of these together with electrolytes are generally used to form a structuring system as is well known in the art.

In the past gums have been incorporated into liquid detergent formulations mainly as viscosity modifiers, as foam stabilisers and to improve product stability.

It has been found that the viscosity of liquid products can be increased by the inclusion of low levels of water-soluble polymers and that the presence of these polymers gives enhanced foaming and detergency.

The term Gum as technically employed in industry, refers to plant or microbial polysaccharides or their derivatives that are dispersible in either cold or hot water to produce viscous mixtures or solutions. In general, gums are hydrophobic or hydrophilic high molecular weight molecules, usually with colloidal properties.

EP 124367 (Unilever) discloses the use of selected polymers and Xanthum gum to enhance the foam stability and viscosity of liquid detergents based on dialkyl sulphosuccinates .

Xanthum gum is disclosed as a thickening agent in hard surface cleaners in EP 839907 (Procter and Gamble) .

The present invention provides a detergent composition that has enhanced foam production, better foam stability and improved detergency.

Description of the Invention

According to the preferred aspect of the invention there is provided a solid hand dish wash composition comprising: a) a cold water soluble, branched hydrocolloid with a viscosity of less than 10,000 mPa . s in water at 1.5%wt. at 25°C, (using the Brookfield method and; b) 40 %wt or less of the total composition of a detergent active.

According to another aspect of the invention provides a process for the preparation of the detergent composition as claimed in any of the preceding claims comprising the steps of neutralising the active detergent where possible and addition as an aqueous dispersion of the hydrocolloid to the active detergent. Detailed Description of the Invention

The present invention relates to hand dish wash composition comprising a cold water soluble branched hydrocolloid, having viscosity of less than 10,000 mPa . s in water at 1.5 %wt at 25°C and 40 %wt of a detergent active.

The composition of the invention has good cleaning properties and excellent foam volume and stability.

The term dishes as used herein means any utensils involved in food preparation or consumption which may be required to be washed to free them from food particles and other food residues, greases, proteins, starches, gums, dyes and burnt organic residues.

Gums

The hydrocolloids referred to in the composition are generally gums of plant origin and usually are plant exudates . The gums in general may be chosen from any of those described in "Industrial Gums" by Whistler R L and Be Miller J N. Published by Academic Press, Inc. (1993).

The viscosity of the hydrocolloids in water at 25°C is measured using a Brookfield viscometer using a number 4 spindle and a shear rate of 60 rpm. The preferred gums being the commonly available vegetable gums selected from gum arabic, tragacanth gum, karaya gum, almond gum and others such as Xanthan gum, gelIan gum.

Particularly preferred are plant derived natural or modified hydrocolloids, especially gum arabic.

The composition optionally comprises of one or more water- soluble polymer and other conventional ingredients.

Preferably the gums are added to the composition at a level of 5% or less, more preferably the gum is added to the formulation at a level from 0.2 to 3 wt% of the total composition.

Optionally other water-soluble polymers such as hydrophilically substituted polysaccharides may also be incorporated .

We have found that Guar gum is not suitable for incorporation into the composition according to the invention. Also unsuitable for use with the invention are hydrocolloids having a viscosity greater than 10,000 mPa.s at 1.5% dispersion level in water, at 25°C (shear rate 60 rpm, no. 4 spindle) .

Abrasives :

A particulate abrasive phase is a useful ingredient of compositions according to the present 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, feldspar, silicas, silicates, other carbonates, aluminas, bicarbonates, borates, sulphates and polymeric materials such as polyethylene.

Preferred abrasives for use in general purpose compositions have a Mho hardness 2-6 although higher hardness abrasives can be employed for specialist applications.

Preferred average particle sizes for the abrasive fall in the range 0.5-400 microns, with values of around 10-200 microns being preferred.

Preferred levels of abrasive range from 4-95wt % on product, more preferably in the range 20-60wt%. 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, feldspar, talc and silica. Calcite, feldspar and dolomite and mixtures thereof are particularly preferred due to their low cost, suitable hardness and colour.

Builders :

The detergency builders used in the formulation 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 ranging from 1 to 50% by wt, preferably from 1 to 30% by wt .

Detergent Actives : The composition according to the invention comprise a detergent actives chosen from anionic, nonionic, cationic, zwitterionic detergent actives or mixtures thereof.

It is preferable if the detergent active comprises an anionic surfactant. 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 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. Particularly preferred is Sodium Alkyl Benzene Sulphonate (LAS) 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 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 polyoxyethylene 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 R₃PO, 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 R₂SO 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 optionally 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 optionally 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 compound to be employed in the detergent composition of the invention will generally be from 1.5 to 25%, preferably.

Fillers :

Fillers suitable for use in the formulation include kaolin, calcium carbonate (calcite) , talc, soapstone, china clay and the like, used singly or in combination, suitably in an amount ranging from 10 to 75% by weight, preferably from 30 to 70 wt%.

Solvents

Solvents suitable in the compositions of the present invention are Alkanolamines which can be mono- or poly- functional as regards the amine and hydroxy moieties.

Preferred alkanolamines are generally of the formulation H₂N- Ri-OH where Ri is a linear or branched alkyl chain having 2-6 carbons. Particularly preferred alkanolamine specially to clean tough or aged soil is 2 -amino-2 -methyl -1-propanol (AMP) .

Other suitable solvents include saturated and unsaturated, linear or branched hydrocarbons, and/or materials of the general formula :

wherein R_x and R₂ are independently Cl-7 alkyl or H, but not both hydrogen, m and n are independently 0-5. Suitable glycol ethers include di-ethylene glycol mono n-butyl ether, mono-ethylene glycol mono n-butyl ether, propylene glycol n- butyl ether and mixtures thereof. Typical levels of solvent range from 1-15% wt .

Electrolyte base :

Suitable electrolyte bases include soluble carbonates and bicarbonates, although use of hydroxides and other alkaline salts is not excluded. Alkali metal carbonates are particularly preferred, with potassium carbonate being the most preferred. Typical levels of electrolytes range from 0.5-5%wt, with l-2.5%wt being particularly preferred. The level of the electrolyte should be such that in use the pH of the composition is raised above the pKa of the alkanolamine, and preferably to a pH at least one unit above the pKa of the alkanolamine.

The compositions according to the invention may optionally contain polymeric structuring agents to aid in providing appropriate rheological properties and in enhancing their distribution and adherence of the composition to the hard surface to be cleaned.

Preferred structuring agents include polysaccharides, such as sodium carboxymethyl cellulose and other chemically modified cellulose materials and other non- flocculating structuring agents such as biopolymer PS87 referred to in US patent No. 4 329 448. Certain polymers such as a polymer of acrylic acid cross- linked with a poly functional agent, for example CARBOPOL R, can also be used as structuring agents. The amount of such structuring agents, when employed, to be used in compositions according to the invention can be as little as 0.001%, preferably at least 0.01% by weight of the composition.

In general the composition of the invention can optionally comprise from 0.1-1% of polymer.

Other Ingredients:

Other ingredients such as perfumes, colouring agents, fluoresces and enzymes can also be used in the formulation, for example, in an amount up to 10 wt%.

Product Form :

Detergent compositions of the present may formulated in different solid forms such as powders, granules and bars. It is most preferable if the composition is a bar.

The invention will now be illustrated with respect to the following non-limiting examples. Examples :

Process for preparation of the composition:

The formulations disclosed in Table 1 were prepared using conventional bar processing technology. The ingredients were mixed in a sigma mixer, extruded into bars and then cut into billets and stamped. In the Example 1, no gum was incorporated and served as Control . In the experimental Example 2, gum arabic dispersed in water was incorporated in the detergent composition.

Table 1

In use properties of the bar:

a. Tough soil cleaning:

The mobile soil that has been polymerised by heating at high temperature is known as tough soil. When the soil is smeared uniformly on a stainless steel plate and heated, it forms a polymerised film on the plate.

0.2g of the detergent bar prepared according to the invention and the corresponding control was uniformly rubbed on the soiled plate and then rinsed with water. The amount of soil removed was evaluated gravimetrically. The experiment was conducted with replicates and analysed statistically.

b. Lather Measurements:

0. lg of the detergent bar prepared according to the invention and the corresponding control were dissolved in 20 ml water taken in different graduated measuring cylinders. The cylinders were shaken 30 times and the volume of lather and the nature of lather were noted.

c. Cleaning of unpolymerised oily soil:

Uniform quantity of vegetable oil is spread on stainless steel plates and the number of such soiled plates that can be cleaned for a particular quantity of the product was assessed. In all the above evaluations 2% gum arabic dispersed in water was used for comparison, since at the corresponding level of dilution of the gum dispersion as done for the detergent bar, the lather, % cleaning of tough soil and number of plates cleaned are negligible or zero.

The data presented in Table 2 shows that the incorporation of gum into the detergent bar gave a very creamy lather and significant improvement in tough soil cleaning as well as increase in number of plates that could be cleaned. It was also found that the bar processability improved significantly by the incorporation of the gum into the bar.

Table 2

It is thus possible to obtain a synergistic detergent composition by incorporating the gum or the water swellable, branched hydrocolloids which have a viscosity < 10, 000 mPa.s at 1.5% dispersion level in water, at 25°C.

Claims

1. A solid hand dish wash composition comprising: a) a cold water soluble, branched hydrocolloid with a viscosity of less than 10,000 mPa . s in water at

1.5%wt. at 25°C, and b) 40 %wt or less of a detergent active.

2. A hand dish wash composition according to claim 1 in which the level of branched hydrocolloid a) is 5wt% or less of the total composition.

3. A hand dish wash composition according to claim 1 or claim 2 in which the composition further comprises a particulate abrasive.

4. A hand dish wash composition according to claim 3 in which the level of particulate abrasive is from 20 to 60 wt% of the total composition.

5. A hand dish wash composition according to claim 3 or claim 4 in which the particulate abrasive is selected from calcite, feldspar, dolomite or mixtures thereof.

6. A hand dish wash composition according to any preceding claim in which the detergent active is an anionic surfactant .

7. A hand dish wash composition according to any preceding claim in which the detergent active is Sodium Alkyl Benzene Sulphonate

8. A hand dish wash composition according to any preceding claim in which the total level of detergent active is from 1.5 to 25 wt%.

9. A hand dish wash composition according to any preceding claim which further comprises a detergency builder.

10. A hand dish wash composition according to any preceding claim which is a bar.

11. A process for the preparation of the detergent composition as claimed in any of the preceding claims comprising the steps of neutralising the active detergent where possible and addition as an aqueous dispersion of the hydrocolloid to the active detergent.