OA10053A - Detergent composition - Google Patents

Abstract

A detergent composition in semi-solid form comprises a non-soap surface active material, a precipitating builder and a hydrotrope, and may contain an amount of water-soluble phosphate containing sequestering builder is less than 30% of that of the precipitating builder. Such compositions have improved lather characteristics. The surface active material may be fatty acyl ester sulphonate, alkyl aryl sulphonate, or primary alkyl sulphate. The builder may be sodium carbonate, and the hydrotrope is urea or glycerol.

Description

1 0053

C343S

DETERGENT COMPOSITION

This invention relates to detergent compositions in semi.-·solid form, that is to say a gel, cream or paste. Such adetergent form is sufficiently solid that it cannot; bepoured at ambient températures and it coheres together ina mass which can, however, be deformed by hand. Thus,this form is distinct from liquids, powders and shapedsolid forms, such as bars.

Semi solid detergent compositions may be used for washingfabrics. Indeed such a detergent form is already marketedin some countries.

For use in fabric washing the semi-solid composition maybe rubbed directly onto the fabric and it may, therefore,be referred to as a direct application product. In such awashing process the concentration of the composition onthe fabric is, at least temporarily, very high.

The; current practice of formulating detergent products tobe used for washing fabrics by agitation in a aqueous washliquor involves ensuring that water hardness and latherare controlled, for example by the use of sequestering 1 0053 - 2 C3439 builders such as water soluble salts of tripolyphosphateand pyrophosphate.

In contrast, for direct application products, the abilityof the product to lather during use is an important,factor.. In many cases, speed of génération and character,that. is appearance and stability, of the lather are theproperties by which the performance of such a product isjudged. Lather also acts as a lubricant for the fabricbeing washing, making rubbing thereof easier.

It has now been found that detergent compositions in serni-solid form with improved lather characteristics may befor'mulated based on the combination of one or moresurfactants, a lather boosting additive and a precipitating builder.

The présent invention accordingly provides a detergentcomposition in semi-solid form comprising: a) a non-soap surface active material; b) a precipitating builder, in an amount such that itsanhydrous weight is at least 5% by weight of thecomposition; and c.) a lather boosting additive selected from watersoluble non-micelle forming and weakly micelle-forming matériels, in an amount from 1 to 5% byweight of the composition; and in which the total amount of water soluble phosphate:containing sequestering builder is less than 30% by weiçrhtbased on the amount of precipitating builder in thecomposition. 1 0053 C3439

The surface active material is a material selected fromanionic, nonionic, amphoteric, betaine, zwitterion.rc,cationic actives and mixtures thereof. Many suitableactives are commercially available and are described in 5 the literature, for example, in "Surface Active Agents"and Détergents", Volumes I and II, by Swartz, Perry andBerch. Non-soap anionic surface active materials willgenerally be preferred in the compositions of theinvention. 10

Although soap may be included it may inhibit latherformation and, therefore, the composition of the inventionis preferably substantially free of soap. If présent, theamount of soap should be less than 2% by weight of the 15 composition.

Anionic surface active materials which are particularlysuitable for use in the composition of the inventioninclude: 20 i) alkyl benzene sulphonates of formula: SO3Na ii) primary alcohol sulphates of formula:

2 5 RO SO3 M and/or iii) fatty acyl ester sulphonate of formula 30 R CH CO, R'

I

SO3 M in which R is a primary alkyl group, preferably having 10to 18 carbon atoms; R' is a primary alkyl group preferably 35 having 1 to 4 carbon atoms; and M is a cation such that

- 4 C3439 1 0053 the surface active matériel is water soluble. Othersurface active matériel which may be used include alkanesulphonates,· secondary alcohol sulphates; olefinsulphonates; and ethoxylated alcohol sulphates. If anonionic detergent active is used, it will generally be anethoxylated alcohol.

Preferably the precipitating builder will be a materialwhich forms a calcium sait which is substantiallyinsoluble in water. Preferred materials include watersoluble alkali métal carbonates, for example sodium orpotassium carbonates or a mixture thereof.

Water soluble phosphate containing sequestering builderswhich should preferably be excluded from the compositioninclude alkali métal orthophosphate, pyrophosphate andtripolyphosphate.

Without. being bound by theory, it is believed the latherboosting additive functions by increasing the tolérance ofthe surface active material to précipitation by electrolytes.

By "weakly micelle forming material" is meant a materialwhich has little tendency to form aggregates of moléculesin dilute aqueous solution.

Preferred lather boosting additives include urea, substituted ureas, short chain alkyl benzene sulphonatessuch. as sodium toluene sulphonate and mixtures thereof.Urea is the more preferred additive.

The detergent composition of the invention preferablycontains, based on the total weight of the composition,from 15 to 45% by weight of a non-soap surface active 10053 - 5 - C3439 material; a precipitating builder in an amount such thatits anhydrous weight is 5 to 40%; more preferably at least10% by weight, most preferably 15 to 25%; and 1 to 5% byweight of a lather boosting additive.

The composition of the invention may also contain conventional detergent additives in amounts normallyprésent in such detergent compositions. Such additivesinclude antiredeposition agents such as sodium carboxymethyl cellulose; inorganic salts such as sodiumsulphate and sodium bicarbonate; fillers such as talc andkaolin; colouring materials; fluorescers; photobleachessilicates such as alkaline sodium silicate germicicles;enzymes; opacifiers; humectants such as glycerol; perfurnesand bleaches. Also included amongst these optionaladditives are structuring agents such as aluminosilicate,amorphous aluminosilicate; and crystalline zeolites alsocommonly used as detergency builders. The aluminosilicateis desirably formed in situ in the composition byincorporating a soluble aluminium sait such as aluminiumsulphate in the composition and also sodium silicate, asdescribed in British Patent Spécification 2 099 012.incorporated herein by reference.

Particularly preferred additives are humectants and, inparticular, glycerol, added to reduce efflorescence; andpartial, inorganic salts, such as sodium bicarbonate, addedto ameliorate any harshness to the skin of the user of thecompositions of the invention.

Compositions of the invention may conveniently be prepaxedby adding the non-soap surface active material,precipitating builder, lather boosting additive and anyother optional conventional detergent additives to waterand mixing the resulting mixture. - 6 C3439 1 0053 A suitable procedure is to heat the water and dissolve init builder and other solid electrolyte (if used) whilemixing under conditions of high shear. When thesecomponents hâve dissolved, the surface active material isadded, followed by the additives required for structuring(if used). Thereafter, and if used, the filler,humectant, brightener and any other remaining conventionaladditives, with the exception of the bleach and enzyme,are added. Finally the lather boosting additive, and, ifused, bleach and enzymes are added.

The surface active material should be fully neutralisedbefore the lather boosting additive is added, to avoiddécomposition of the latter during manufacture.

The invention is further illustrated by the following non-limiting Examples, in which the percentages are by weightof the composition.

In use, fabrics to be washed are contacted with a composition according to the invention or with a liquorformed by dilution of the composition and then rinsed.

Example A number of detergent creams were prepared by the procedure described above using raw materials carefullysieved to exclude particles larger than 100 microns.

Their formulations are set out. in the following table:- - 7 C3439 1 0053

Table 1

Formulation 1 2 3 4 Component Branched alkyl (C12) 22 22 - - benzene sulphonate Primary alcohol - - 22 22 (coconut) sulphate Sodium carbonate 20 5 15 5 Sodium pyrophosphate (STP) - 6 - 6 Urea 1 1 1 1 Glycerol - - 1 1 Water/minors --- — to 100

Assessment of the stability of lather was determined bythe following procedure: A 1 gm sample of a cream was dissolved in 1 litre ofdemineralised water. Commercially available kaolin claywas added to the water to give a soil concentration of 1gm/litre. The température of the resulting solution was25°C. It was agitated by hand for 30 secs and thenallowed to stand for 20 minutes. During this time thevolume (measured in litres) of lather generated andremaining on the surface of the wash solution was measuredperiodically.

The speed of génération of lather during hand washing wasdetermined by the following procedure: A 0.9 gm sample of a cream was applied evenly to apolyester/cotton test cloth soiled with a mixture of clay - 8 - C3439 1 00 5 3 and synthetic sébum. The test cloth was washed by handrubbing (for various lengths of time) the cream onto thetest cloth, which was laid across a corrugated wash board.The maximum wash time was 60 seconds. Thereafter thelather generated was collected in a measuring cylinder andthe height of lather measured in mm.

Example 1

In this example the lather stability of a cream accordingto the invention (Product 1) was compared with aconventional cream formulation containing a high level ofsodium pyrophosphate (Product 2). The results in table 2demonstrate the product according to the invention hasimproved lather stability compared to the conventionalproduct.

Table 2 Lather Volume (litres) Standing Time (mins) Product 1 Product 2 0 75 72 2 49 45 5 40 24 10 28 8 15 20 4 20 14 2

Example 2

In this example the speed of génération of lather of aformulation according to the invention (Product 1) wascompared to a conventional cream formulation (Product 2).The results in table 3 demonstrate that the speed of - 9 C3439 1 0053 génération of the lather is faster for a product accordingto the invention than for a conventional product. Table 3 Lather Height (mm) Washing Time (secs) Product 1 Product 2 20 106 70 40 135 119 60 242 205

Example 3

This example demonstrates the improvement in latherstability of a composition according to the invention(Product 3) compared to a conventional cream composition(Product 4) is maintained when the branched chain alkylbenzene sulphonate is replaced by a primary alcoholsulphate (EMAL 10, a commercial coconut based PAS suppliedby Kao).

Table 4

Standing Time (mins) 0 2 5 10 15 20

Example 4

In this example the effect onthe ratio of sodium carbonateformulation 2 was examined.

Lather Volume (litres)

Product 3 Product 4 74 70 52 48 47 42 42 38 38 36 34 29 lather stability of alteringto sodium pyrophosphate in t» - 10 10053 C3439

Table 5 % ProportionSodium Carbonate 5 100948371450

STPP 0 6 17 29 55 100

Lather Volume (litres)after a standing time of 2 minutes414040392618 10

Claims (8)

1. -Il - C3439 1 0053 CLAIMS

   1. A detergent composition in semi-solid formcomprising: a) a non-soap surface active material; b) a precipitating builder, in an amount such thatits anhydrous weight is at least 5% by weight ofthe composition; and c) a lather boosting additive selected from watersoluble non-micelle forming and weakly micelle-forming materials, in an amount from 1 to 5% tyweight of the composition; and in which the total amount of water solublephosphate containing sequestering builder is lessthan 30% by weight based on the amount ofprecipitating builder in the composition.
2. 2. A detergent composition according to claim 1comprising 15 to 45% by weight of a non-soap surfaceactive material.
3. 3. A detergent composition according to claim 1 whereinthe builder is a material which forms a calcium saitwhich is substantially insoluble in water.
4. 4. A detergent composition according to claim 3 whereinthe builder is a water-soluble alkali métalcarbonate. i î 0 053 - 12 - C3439
5. 5. A detergent composition according to claim 1 whereinthe lather boosting additive is selected from urea,substituted dérivatives of urea, short Chain alkylbenzene sulphonates and mixtures thereof. 5
6. 6. A detergent composition according to claim 1 furthercomprising aluminosilicate.
7. 7. A detergent composition according to claim 1 further 10 comprising a humectant.
8. 8. A method of washing fabrics comprising contacting thefabric with a composition according to any one of thepreceding daims, or a liquor formed by dilution ofthe composition followed by rinsing the fabric. 15