GB2168717A - Controlling viscosity of fabric softening heavy duty liquid detergent containing bentonite - Google Patents

Abstract

A fabric softening heavy duty liquid detergent composition of controlled viscosity, which does not thicken excessively on ageing, includes surfactants such as sodium linear higher alkylbenzene sulphonate and sodium alkyl polyethoxy sulphate, water-soluble builder salt, finely divided swelling bentonite, low molecular weight polyacrylate and water. Such product is a stable pourable liquid of desired viscosity, density and pH, for use in washing machines, for hand washing of laundry and for pre-treatment of badly soiled portions of items to be laundered.

Description

SPECIFICATION Controlling viscosity of fabric softening heavy duty liquid detergent containing bentonite The present invention relates to a fabric softening heavy duty liquid detergent composition. More particularly, it relates to such a liquid detergent which comprises certain synthetic organic detergent and builder components together with a swelling bentonite and a low molecularweight polyacrylate in an aqueous medium. The product of the present invention is of an improved stable viscosity orthickness even after being stored for a month, is readily pourable and is a good laundry detergent and fabric softener.

Heavy duty liquid detergents, useful for machine washing of laundry, have been marketed and have been described in various patents and in the literature.

Bentonite has been included in particulate detergent compositions as a fabric softener and has been utilised in aqueous compositions as a thickener, which can help to maintain insoluble particulate materials, such as abrasives, suspended in a liquid medium. In U.S. patent 4,469,605 (Ramachandran and Grand) bentonite was successfully employed in the manufacture ofwhatwas then considered to be an acceptable stable fabric softening heavy duty liquid detergent in which the bentonitewasthefaabric softening component. It has now been learned thatthe detergent compositions described in that patent while stable and relatively constant in viscosity on storage when made in the laboratory and pilot plant, often thicken on storage when made with production equipment.

In accordance with the present invention a fabric softening heavy duty liquid detergent of a density in the range of 1.15 to 1.35 g/ml at room temperature, a pH inthe range of 9.5to 11, and a viscosity in the range of 1,000 to 5,000 centipoises, which does not increase to more than 5,000 or 6,000 cps on 30 days quiescent storage at room temperature, comprises 5 to 15% of alkali metal linearor branched higher alkylbenzene sulphonate wherein the higher alkyl group is of 10 to 1 6 carbon atoms, 1.5to 5% of alkalimetal alkyl polyethoxy sulphate wherein the alkyl group is of 10 to 16 carbon atoms and the polyethoxy is of 2 to 11 ethylene oxide groups, 5 to 25% of water soluble builder salt, 5 to 20% of a swelling bentonite, 0.05 to 0.5% ofwatersoluble polyacrylateofa molecular weight in the range of 1,000 to 5,000 and 40 to 75% of water. Such a liquid detergent is a commercially acceptable heavy duty laundry detergent, capable of satisfactorily cleaning laundry items containing both oily and particulate soils and simultaneously depositing on such laundry items sufficient bentonite to soften them appreciably. The described compositions may also be employed for the pre-treatment of badly soiled areas, such as collars and cuffs, of items to be laundered, in which treatment the presence of the bentonite in the liquid, which may be applied directly to the soiled areas, with some rubbing, is considered to be useful in mechanically assisting in loosening and/or removing the soil.

The synthetic anionic organic detergent mixture present in the liquid detergents of the present invention is a mixture of linear or branched (preferably linear) higher alkylbenzene sulphonate and alkyl polyethoxysulphate.Whileotherwatersolublelinear higher alkylbenzenes sulphonates may also be present in the formulas of the present invention, such as potassium salts and in some instances the ammonium and/oralkanolammoniumsalts,whereappropriate,it has been found that the sodium salt is highly preferred, which is also in the case with respect to the alkyl polyethoxy sulphate detergent component. The alkylbenzene sulphonate is onewherein the higher alkyl group is of 12to 16 carbon atoms, preferably 12 to 15, more preferably 12 to 13, and most preferably 13 carbon atoms.The alkyl polyethoxy sulphate, which also may be referred to as a sulphated polyethoxylated higher linear alcohol or the sulphate condensation product of a higherfatty alcohol and ethylene oxide or polyethylene glycol, is one wherein the alkyl group is of 10 to 16 carbon atoms, preferably 12 to 15 carbon atoms, e.g. about 13 carbon atoms; and which includes 2 to 11 ethylene oxide groups, preferably 2 to 7, more preferably 3to Sand most preferably3 or about3 ethylene oxide groups In suitable circumstances other anionic detergents, such as fatty alcohol sulphates, paraffin sulphonates, olefin sulphonates, monoglyceride sulphates, sarcosinates, sulphosuccinates and similarly functioning detergents, preferably as the alkali metal, e.g. sodium salts, can be present, sometimes in partial replacement ofthe previously mentioned synthetic organic detergents, but usually, if present, in addition to such detergents.

Normally such other detergents will be sulphates or sulphonated products (usually as the sodium salts) and will contain long chain (8 to 20 carbon atoms) linearorfattyalkyl groups. In additionto anysuch other or supplementing anionic synthetic organic detergents there also may be present nonionic and amphoteric materials such as the Neodols (Registered Trade Mark) sold by Shell Chemical Company, which are condensation products of ethylene oxide and higherfatty alcohols, e.g. Neodol 230-6.5, which is a condensation product of a higherfatty alcohol of about 12to 13 carbon atoms with about 6.5 mols of ethylene oxide. Illustrations of the various detergents and classes of detergents mentioned may be found in the text Surface Active Agents, Vol.II, by Schwartz, Ferry and Berch (Interscience Publishers, 1958), and in a series of annual publications entitled McCutcheon's Detergents and Emulsifiers, for example, that which was issued in 1969, the descriptions of which are incorporated herein by reference.

A builder salt combination for use in the present invention, which has been found to satisfactorily improve detergency of the mixture of synthetic anionic organic detergents, which produces the desired pH in the liquid detergent and in the wash water, and which coacts with the detergent and the bentonite in the washing and softening process, is a mixture of sodium tripolyphosphate and sodium carbonate.

Although in some instances incompletely neutralised tripolyphosphate may be used, normally the phosphate employed may be considered as being pentasodium tripolyphosphate, Na5P3O1c. Of course, in some instances, as when potassium salts of other materials are present, ion interchange in an aqueous medium may result in othersaltsthan the sodium tripolyphosphate being present, butforthe purpose ofthis specification it will be considered that sodium tripolyphosphate, as the pentasodium salt, the material which is normally charged to the mixerto makethe present liquid detergent, is the tripolyphosphate preferably employed.

Otherpreferredbuildersaltswhich may be used in place of sodium tripolyphosphate and sodium carbonate or in addition thereto include sodium citrate and potassium citrate, and sodium nitrilotriacetate (NTA).

The corresponding potassium salts may be used in partial replacements of these other builder salts, too.

Of course, various mixtures ofthe mentioned water soluble builder salts can be utilised. The tripolyphosphate-carbonate mixture described has been found to be most preferred, although the other builders, and mixtures thereof, are also operative. Still other builders may be employed as supplements, in addition to the proportions ofthe above mentioned builders, subsequently to be described herein. Thus, other phosphates, such as tetrasodium pyrophosphate ortetrapotassium pyroph osph ate, sodium bicarbonate, sodium sesquicarbonate, sodium glu- conate, borax, sodium silicate, and sodium sesquisilicate, may be employed.Also useful may be the polyacetal carboxylate builders, which are described in U.S. patent 4,144,226 and other related Monsanto Company patents, which are available underthe trade name Builder U.Amongthewaterinsolublebuilders that may be used are the zeolites, such as Zeolite A, usually in the form of its crystalline hydrate, although amorphous zeolites may also be useful. It is a feature ofthe present invention that sodium silicate is not needed to make an effective heavy duty detergentsoftener composition and therefore such silicate will usually be omitted from the presentformulas, and any undesirable properties it may possess will therefore be avoided.For example, any tendency for silicate to reactwith other components ofthe liquid detergent, such as zeolite, sodium carbonate, or other builder, to produce insoluble material which maytendto adhere tothe laundry and thereby adversely affectthe desirable brightcoloursofsuch laundry, will be avoided. The absence of silicate in the detergent medium also preventsformation of insoluble siliceous decomposition products of the silicate, which could tendto adversely affectthe appearance of the liquid detergent and the laundry if such became apparent in the liquid detergent or were deposited on the laundry.

The bentonite employed is a colloidal clay (aluminium silicate) containing montmorillonite. The type of bentonitewhich is most useful in making the compositions in accordance with the present invention is that which is known as sodium bentonite (orWyoming or Western bentonite), which is normally of a light to cream colour or may be tannish impalpable powder which, in water, can form a colloidal suspension having strnngi-thixotrnpic properties. In many instances a potassium bentonite or a mixed sodium potassium bentonite may be used instead.In water the swelling capacity of such clay will usually be in the range of3to 15 or20 mIIg, preferably7to 15 ml/g, and its viscosity, at 6% concentration in water, will usually be in the range of 3 to 30 centipoises, preferably 8 to 30 centipoises. Preferred swelling bentonites of thins tvpe are sold underthetrade name Mineral Colloid, as industrial bentonites, by Benton Clay Company, a principal supplier of clays to industry. These mate rials,which are the same as those formerly sold under the trade markTHIXO-JEL, are selectively mined and beneficiated bentonites, and those considered to be most useful are available as Mineral Colloid Nos. 101, 102,103 and 104 corresponding toTHIXO-JEL's Nos.

1,2,3 and 4. Such materials have pH's (6% concentration in water) in the range of 8 to 0.4, maximum free moisture contents (before addition to the liquid detergent medium) of 4% to 8% and specific gravities of about 2.6. For the pulverised grade of such materials at least about 85% will pass through a 200 mesh U.S. Sieve Series sieve (which has openings 74 microns across). Preferablyallthebentonitewill pass through a 200 mesh sieve and most preferably all of it will pass through or be aboutthe size that will just pass through a No.325 sieve (which has openings 44 microns across), so thatthe equivalent diameter of the bentonite may be considered as being less than 74 microns and more preferably about or less than 44 microns.A useful commercial source offinely divided bentonite of satisfactory colour is American Colloid Company and oftheir available bentonitesthat sold as AEG 325 bentonite is considered to be interchangeable with the previously mentioned Mineral Colloid's and THIXO-JEL's. Although beneficiated Wyoming bentonite is preferred as a component of the liquid detergent compositions ofthe present invention, other bentonites, including the synthetic bentonites (those made from bentonites having interchangeable calcium and/or magnesium, by sodium carbonate treatment) are also useful and are intended to be included in compositions ofthe present invention.

Typical chemical analyses of some bentonites that are useful for making the liquid detergent ofthe present invention showthatthey contain from 64.8 to 73.0% of SiO2, 14to 18% or ofAl2O3, 1 .6to 2.7% of MgO, 1 .3to 3.1 % of CaO, 2.3 to 3.4% of Fe2O3, 0.8 to 2.8% of Na2O and 0.4to 7.0% of K2O.

Employment of bentonite as afabricsoftening agent in the liquid detergent compositions ofthe present invention has the advantage thatthe bento- nite does not have to be dried, as in a spray dryer, and therefore the risk of losing the softening powerofthe bentonite, due to immobilisation ofthe component platesthereofbyoverdrying, is avoided. Also, it is unnecessary to havethe detergent composition of the present invention of such a formulation as to promote quick disintegration ofthe detergent beads in the wash water to release the bentonite particles because in the liquid detergent such particles are not agglomerated into hard masses which could require additional time for disintegration.

The polyacrylate employed is a low molecuar weight sodium polyacrylate, such molecularweight usually being within the range of about 1,000 to 5,000, preferably 1,000 to 3,000, and most preferably 1,500 to 2,500, e.g. about 2,000. The mean molecular weight will usually be within the range of 1,200 to 2,500, such as about 2,000. Although other polyacrylates may sometimes be substituted in partforthe described sodium polyacrylate, including other alkali metal polyacrylates, it is preferred that such substitutions, when permitted, be limited to a minor proportion of the material, and preferably the polyacrylate employed will be sodium polyacrylate. Such materials are available from Alco Chemical Corporation under the name Alcosperse.The sodium polyacrylates are available as clear amber liquids or powders, com pletely soluble in water, with the solutions being of about 25to 40% solids content, e.g. 30%, and with the pH of such solutions or of a 30% aqueous solution of the powder being in the range of about 7.0 to 9.5.

Among these products those preferred are presently sold byAlco Chemical Corp. as Alcosperses 104, 107, 107D, 109 and 149, of which Alcosperse 1 07D, a 100% solids powder, is highly preferred, although Alcosperse 107, a 30% aqueous solution, may be used instead with little difference in results. Both are sodium polyacrylates with the liquid (107) being of a pH in the 8.5 to 9.5 range and the pH ofthe powder (107D) being in the 7.0 two 8.0 range, at a 30% concentration in water.

The only other required component of the liquid detergent compositions in accordance with the present invention is water. Normally the hardness content of such water will be less than about 300 ppm as CaCO3, and preferably it will be less than 150 ppm.

Often it may be desirable to utilise deionised water although often city water with less than 50 or 100 ppm hardness content will be about as satisfactory. While harderwaters may be successfully employed in making the liquid detergent compositions of the present invention it is considered that soft waters have less likelihood of producing some objectionable materialswhich could adversely affectthe appearance ofthe liquid detergent or which could deposit objectionably on laundry during washing.

Various adjuvants both aesthetic and functional, may be present in the liquid detergent compositions ofthe present invention, such as fluorescent brighteners, perfumes and colourants. The fluorescent brighteners include the well known stilbene derivatives, including the cotton and nylon brighteners, such as those sold underthe trade markTinopal, e.g. 5BM. The perfumes that are employed usually include essential oils, esters, aldehydes and/or alcohols, all of which are known in the perfumery art. The colourants may include dyes and water dispersible pigments of various types, including ultramarine blue. Because of the lightening effect due to the presence ofthe bentonite in the liquid detergent, colours of the product may often be attractive pastels.Titanium dioxide may be utilised to lighten to colour ofthe productfurther orto whiten it. Inorganicfiller salts, such as sodium sulphate and sodium chloride may be present, as may be antiredeposition agents, such as sodium carboxymethylcellulose; enzymes; bleaches; bactericides; fungicides; anti-foam agents, such as silicones; antisoiling agents such as copolyesters; preservatives, such asformalin; foam stabilisers, such as lauric myristic diethanolamide; and auxiliary solvents, such as ethanol. Normally the individual proportions of such adjuvants will be less than 3%, often less than 1 % and sometimes even less than 0.5%, exceptfor anyfillers and solvents, and additional detergents and builders, forwhich the proportions may sometimes be as high as 10% .The total proportion of adjuvants, including non-designated synthetic detergents and builders, will normally be no more than 20% of the product and desirably will be less than 10% thereof, more desirably less than 5% thereof. Of course, the adjuvants employed will be non-interfering with the washing and softening actions ofthe liquid detergent and will not promote instability ofthe product on standing. Also, they will not cause the production of objectionable deposits on the laundry.

The proportions of various components in the liquid detergentcompositionsofthe present invention will be within the range of 5to 15%, preferably 6 to 12%, more preferably 8 to 10% and most preferably about 9% ofthe sodium linear higher alkylbenzene su Iphonate; 1 .Sto 5%, preferably 1.5 to 3%, more preferably 1.7 to 2.7%, and most preferably about 2% ofthe sodium alkylpolyethoxy sulphate; 5 to 25%, preferably9to 22%, and more preferably about 12to 19% of the builder salt; Sto 20%, preferably8to 15%, more preferably 10 to 14%, and most preferably about 12% ofthe swelling bentonite; and 40 to 75%, preferably 50 to 70%, more preferably 55 to 70%, and most preferably about 60% of water. Ofthe builder salts, when they are sodium tripolyphosphate and sodium carbonate, the proportions thereof will usually be 7 to 15%, preferably9to 13%, and more preferably about 11 ofthe tripolyphosphate, and 2 to 7%, preferably3 to 6%, and more preferably about 4% of sodium carbonate; with the ratio of tripolyphosphate to carbonate preferably being within the range of 2:1 to 6:1.

The liquid detergents may be made by appropriately mixing the various components thereof, preferably with the bentonite being added to a pre-mix of most of the water with tripolyphosphate, carbonate, CMC and anionic detergent. For example, the polyphosphate and carbonate, in finely divided form, normally sufficientlyfineto pass a No. 160 screen (which has openings between 88 and 105 microns across), may be admixed with and dissolved in most of the water, after which the CMC and anionic detergent may be admixed, followed by bentonite, polyacrylate and the rest oftheformula components, in any suitable order.

The portion ofthe water held out is then added to the rest ofthe liquid detergent and causes thinning ofthe thickened liquid to a desired apparent viscosity.

Experience has shown that the desirable proportion ofwaterto hold backand admix inthe manufacturing process is normally5to 20% ofthefinal liquid detergent, e.g. about 10% thereof. During the mixing of the various components with the aqueous medium, and especially when the bentonite is added and the remaining water is admixed, it is importantto maintain the mixture in motion, as by continuing to mix orstirit. Preferably, the mixer is neverturned off and the process is continuous, normally taking about 3 to 30 minutes per batch.While the water may be warmed to promote dissolution of the various product components therein and to promote dispersion ofthe bentonite, such is not necessary and room tempera ture water, e.g. water at a temperature in the range of 1 5"to 30"C, such as 20" to 25"C, may be used.

The viscosity of the liquid detergent compositions ofthe present invention immediately after completion ofthe manufacturing procedure is normally in the range of about 1,000 to 2,000 centipoises, e.g. about 1,500 cps.The liquid detergent is intended for packaging in and dispensing from comparatively narrow necked glass or plastic bottles, from which it must be pourable initially and after normal ageing.

When the polyacrylate is omitted from the formula it has been found thatcommercially manufactured liquid detergent is initiallythicker and becomes more viscous on standing, so that after about a month of storage at room temperature its viscosity may have increased from about 3,000 cps to over 18,000 cps. At 18,000 cpsthe liquid detergent is too thick to he satisfactorily pourable and requires the consvrnerto shake it or stir it so as to thin it sufficiently so that it will be pourable from the bottle.Needless to say, such thickening characteristic is undesirable.Thepreferred viscosityforthe liquid detergent compositions ofthe present invention is about 4,000 cps + 1,000 cps, and viscosities like these are found to be those preferred by consumers. Utilising the polyacrylate component andtheformulas ofthe present invention, as will be exemplified in Example 1, it isfound thatafterabouta month's storage the viscosity has increased to about 4,000 cps (4,050 after 28 days) and further storage does not result in any significantfurther viscosity increase.The viscosities described are measured by means of a Brookfield LVTviscometer, utilising á No.2 spindleforviscosities less than 2,000 cps, and No.3 spindleforviscosities in the range of 2,000 to 9,000 cps, and a No.4spindleforviscositiesgreaterthan 9,000 cps. All viscosities are measured at 12 rpm and at25"C.

The invention may be put into practice in various ways and a number of specific embodiments will be described to illustrate the invention with reference to the accompanying examples.

Unless otherwise indicated all parts are by weight and all temperatures are in "C in this specification, including the working examples, and the claims.

EXAMPLE 1 Components Percent Sodium lineartridecylbenzenesulphonate 8.8 Sodium alkyl polyethoxysulphate (alkyl = 2.2 linearalkyl of 12to 15 carbon atoms; polyethoxy = 3 ethoxy groups Pentasodium tripolyphosphate 11.0 Sodium carbonate (anhydrous) 4.0 Sodium carboxymethyl cellulose 0.2 Sodium polyacrylate (M.W. = 2,000) 0.15 Titanium dioxide 0.5 Formalin 0.2 Bentonite (325 mesh (44 microns), American 12.0 Colloid Co. 325AEG) Fluorescent brightener (Tinopal LMS-X 0.3 [CIBA-GEIGY]) Perfume 0.4 Dye (Cl Acid Blue 9/Cl 42090) 0.0045 Pigment (Cl Pigment Blue 29/Cl 77007) 0.04 Water (deionised) 60.7055 100.0 About 84% ofthe formula amount of water is added to a suitable mixer, such as a vertical cylindrical tank equipped with heating and cooling mens and connected to a discharge pump. The formula amounts of polyphosphateand carbonate (of particle sizes that pass a No. 160 sieve) are added, with stirring (by a Lightnintype mixer),followed bytheCMC.The anionic detergents are next admixed, after which the other components are admixed in any suitable order.

The balance ofthewateris added, thinning the mix, and the perfume is then added, with mixing, and the product is ready to be pumped out ofthe mixer and into end use narrow necked bottles, which serve as dispensing containers. During the mixing operation, all ofwhich takes about nine minutes, the materials added and the final product are at a temperature of about 20 C. In some cases, to promotefasterdissolv- ing and quicker dispersion ofthe components, the temperature ofthe water and other components charged may be raised to 40into 500C, so that the final producttemperature may be about 30"C to 400C in which case the mixing time may be reduced to about 5 or6 minutes.

The liquid detergent resulting (at room temperature) has a viscosity of about 1,550 cps and pours satisfactorily from a plastic detergent bottle with a discha rge opening of about 2.5 cm diameter. It has a pH of about 10.5. The liquid detergent is employed to wash a mixed load ofsoiled laundry, some ofwhich includes cotton swatches and polyester/cotton swatches soiled with particulate soil and with sebum soil.The liquid detergent is added to the tub of a standard washing machine with about one-half cup of the liquid detergent being employed per wash (to make the concentration of liquid detergent in wash water about 0.18% ). The temperature ofthe wash water is 21 "C (to test the "cold" waterwashing capabilities ofthe product) andthe water is of a mixed calcium and magnesium hardness of about 150 ppm asCaCO3.Afterwashing ofthe laundered items and the test swatches they are either "line dried" or machine dried (in a conventional laundry dryer).

The same operation as described above are repeated for a control detergentformulation wherein the sodium polyacrylate is omitted, being replaced by water.

Both the experimental composition (that containing sodium polyacrylate) and the control composition are excellent fabric softening detergents, but the experimental product is far superior in one important characteristic, namely maintenance of a satisfactory viscosity on storage. Thus, afterfive days the viscosity ofthe experimental product is 2,850 cps, whereas that ofthe control is 9,400 cps; after 14 days the viscosities are 3,400 and 13,500 cps respectively; after 21 days the viscositiesare3,500 and 14,500 cps, respectively; and after 28 days they are 4,050 and 18,500 cps, respectively. At 4,050 cps the product is still pourablefrom the bottle but at 18,500 cps it is not pourable and must be shaken orstirredsoasto bedispensible.Subsequent to 28 days after manufacturethe viscosity ofthe experimental formula does not increase significantly and any increase in viscosity ofthe control is not of great significance because over 18,000 cpsthe product is unmarketable anyway.

From the experiment it is evident that the presence of a very small proportion of sodium polyacrylate significantly helps to stabilise the viscosity ofthe described detergent compositions on storage, which effect was not previously recognised by the art.

The experimental liquid detergent is of an attractive light blue uniform appearance and on storage does not settle into different layers of materials.

In addition to being useful as a detergent for machine washing, the product of the present invention may be employed in hand washing of laundry and as a liquid for pre-treatment of excessively soiled areas of laundry. In hand washing of laundry, to promote maximum deposition of bentonite on the laundry and thereby to improve the softening effects thereof,thewashing solution is allowed to drain out of the washtub through a bottom drain so that it passes throughthe laundry, afterwhichthe laundry may be rinsed in normal manner. When employed as a pre-treatmentfor soiled areas of laundry the liquid detergent is preferably applied full strength (although dilutions may also be used) to soiled areas and is rubbed into them.During such application and rubbing the bentonite assists the detergent in loosening and removing the soil, whether it be oily or particulate soil, and at the same time some ofthe bentonite adheres to the fibres of the material of the laundry,thushelpingtosoften laundry materials at such location. Such softening ofthe material may contribute to lessersoiling of the area and lessersoil retention in thefuture, especially when the soiled areas are shirt cuffs or collars.

EXAMPLE 2 AliquiddetergentlikethatofExample 1 isformulated, using 9% of a lineardodecylbenzene sulphonate in place of the 8.8% of lineartridecylbenzene sulphonate, 2% of sodium alkyl polyethoxy sulphate wherethealkyl group isofl2to 13carbon atoms and the polyethoxy is of an average of 6.5 ethoxy groups, instead of the 2.2% ofthat previously employed, 0.2% of Alcosperse 107 (solids content basis) instead of Alcosperse 1 07D (used in Example 1), 11% ofthe STPP. 6% of sodium carbonate, 15% of bentonite (Mineral Colloid 101), the adjuvants previously mentioned and 55.7% of city water of 100 ppm hardness, as CaCO3.The additional sodium carbonate improves the miscibility of the various components during the manufacturing procedure and the replacementofthe detergent does not significantly adversely affect the properties of the product. The product is made in essentially the same manner as previously described.

The liquid detergent is a stable pourable liquid having the desired cleaning and softening properties described for the liquid detergent of Example 1, whether used for machine washing or hand washing of laundry or for pre-treatments thereof. The viscosity thereof does not exceed 5,000 cps after a month's storage at room temperature.

Similarly, acceptable liquid detergents are made when 3% of sodium lauryl alcohol sulphate, 2% of Neodol 23-6.5 and 0.5% of silicone antifoam oil are incorporated in the product by addition to the components of Example 1 (replacing water). Also when sodium citrate or potassium citrate is employed to replacethesodium carbonate (orwhen only partial replacements of such material, e.g. 30% replacements, are effected with such citrates ortrisodium nitrilotriacetate) useful liquid detergents will result, having desirable properties, like those ofthe compositions previously described.

EXAMPLE 3 A liquid detergent like that of Example 1 is made but only 2% if sodium carbonate is employed in the formulation, with the water content being increased correspondingly. Although the sodium carbonate content is decreased the mix is still processable to a final product of desirable properties, which is useful as a heavy duty laundry detergentforwashing cotton and synthetic materials and softening then, and is also useful as a pre-treatmentfor such laundry. When 0.5% of sodium carboxymethyl cellulose is added to the formula in place of part of the water thereof improved whitening ofthe laundry is obtained without substantial loss of softening power due to the anti-redeposition activity of the CMC.

In other variations of the invention, when the proportions ofthe various components of the liquid detergent of Example 1 are changed + 10% or 120%, without going outside the ranges given in this specification, stable, pourable liquid detergents of useful cleaning and softening effects result. In some such products it may be desirable to include as much as 10% ofZeoliteAor upto 4% of sodium silicate of Na2O:SiO2 ratio of about 1 :2.4, although the silicate will often be avoided, and ifthe zeolite is present, to avoid depositing ofzeolite-silicate aggregates or reaction products, the silicate will normally be omitted.

As is seen from the preceding description and the working example, the fabric softening heavy duty liquid detergents ofthe present invention are stable, uniform, attractive and functional. Despite the presence of a substantial proportion of gelling agent (bentonite) in a liquid medium, they do notform objectionable gels and they remain pourable during storage. Also, despite lengthy storage, during which the suspended bentonite is subjected to intimate contactwith surface active agents and inorganic salt builders in an aqueous medium,the bentonite does not objectionably agglomerate and its softening action on laundry is not destroyed.By using the mentioned detergents and builders in an aqueous medium in which sodium polyacrylate is also present, there is produced a liquid detergent which, despite the content of a substantial proportion ofbentoniteofthe swelling type, remains liquid and pourable and retains its physical and chemical characteristics, which allow itto be deposited on the laundry and act as a lubricant for rhe fibres thereof, thereby promoting softening of such laundry. Also, as was previously mentioned, by employment ofthe liquid medium the possibility that the bentonitewould be deactivated by overheating, as in a spray drying tower, is obviated.

The present liquid detergents, in addition to being useful as products for machine and hand washing of laundry, are also good for pre-treatments of stained portions of laundry, in which treatments it is considered that the bentonite content assists in removing the stains and in softening the stained area (and the product is also subsequently employed forwashing purposes).Thus, from the foregoing recitation of the properties and advantages ofthe present invention it can be seen that it represents a significant advance in the detergent composition art because tallows convenient employment of a non-gelling liquid detergent to both clean and soften laundry (and to pre-treat it) while utilising excellent anionic syntheticorganic detergents and not having to incorporate with such anonic detergents adversely chemically reactive cationic materials, such as quaternary ammonium salts,fortheirsoftening action. Furthermore, the bentonites employed are not ecologically harmful, as the quaternary ammonium salts might be, and do not cause buildups of objectionable fatty deposits on laundry,which often cause itto look discoloured, as the quaternaries sometimes do.

While the sodium salts and sodium compounds of the various components of the present liquid detergents have been described becausetheyare especial ly satisfactory and are commercially available,the corresponding potassium compounds may besubsti- tuted forthem, at least in part, and are also within the present invention. Thus, potassium detergents, potassium builder salts, potassium bentonites and potassium adjuvant salts can be used and such are intended to be included with sodium compounds as "alkali metal" compounds in the formulas given.

The invention has been described with respect two various embodiments and working examples but is not to be limited to these because it is evident that one of skill in the art, with the present specification before him, will be able to utilise substitutes and equivalents without departing from the invention.

Claims (13)

1. Afabricsoftening heavy duty liquid detergent composition comprising watersolublesyntheticorga nicdetertentoftheanionicsulphonated and/or sulphatedtype,watersoluble builder salts, swelling bentonite and water and low molecular weight of alkali metal polyacrylateeffectiveto imparttothe composition resistance to increase in viscosity on standing, and the composition being resistantto phase separation on standing.

2. A heavy dute liquid detergent as claimed in Claim 1 in which the anionic detergent is present in an amount of 6.5 to 20% by weight

3. A heavy duty liquid detergent as claimed in Claim 1 or Claim 2 in which the builder is present in an amountof5to25% byweight.

4. A heavy duty liquid detergent as claimed in Claim 1,2 or3 in which the bentonite is present in an amountof5to 20% by weight.

5. A heavy duty liquid detergent as claimed in Claim 1,2,3 or4 in which the polyacrylate is present in an amount of 0.05 to 0.5% by weight.

6. A heavy duty liquid detergent as claimed in any oneofClaims 1 to 5 in which the molecularweightof the polyacrylate is in the range of 1,000 to 5,000.

7. Afabric softening heavy duty liquid detergent composition of a density in the range of 1.15to 1.35 g/ml at room temperature, a pH in the range of 9.5 to 11, and a viscosity in the range of 1,000 to 5,000 centipoises, which does not icrease to more than 6,000 centipoises on 30 days quiescent storage at room temperature, which comprises 6.5 to 20% of water soluble synthetic organic detergent or the anionicsulphonatedand/orsulphatedtype,5to25% of water soluble buildersaltforthe detergent(s), 5 to 20% ofswelling bentonite, 0.05 to 0.5% of of sodium polyacrylate of molecular weight in the range of 1,000 to 5,000 and 40 to 75% of water.

8. Afabricsoftening heavyduty liquid detergent having a density in the range of 1.15to 1.35 g/ml at room temperature, a pH in the range of 9.5 to 11, and a viscosity in the range of 1,000 to 5,000 centipoises, which doesnotincreaseto morethan6,000 centipoises on 30 days quiescent storage at room temperature, which comprises 5 to 15% ofalkylimetal linear or branched higher alkylbenzene sulphonate wherein the higheralkyl group is 10to 16 carbon atoms,1.5 to 5% of alkali metal polyethoxy sulphate wherein the alkyl group is of 10 to 16 carbon atoms and the polyethoxy is of2 to 11 ethylene oxide groups, 5 to 25% of water soluble bu ilder salt,5 to 20% of a swelling bentonite, 0.05 to 0.5% of a water soluble polyacrylate of molecular weight in the range of 1,000 to 5,000 and 40 to 75% of water.

9. A heavy duty liquid detergent as claimed in Claim 8,the viscosity of which does not increase to more than 5,000 centipoises on 30 days quiescent storage at room temperature,which comprises 6to 12% of sodium linear higher alkylbenzene sulphonate wherein the higher alkyl group is of 12 to 15 carbon atoms, 1.5 to 3% of sodium alkyl polyothoxysulphate wherein the alkyl group is of 12 to 16 carbon atoms and the polyethoxy is of 2 to 7 ethylene oxide groups, 7to 15% of finely divided bentonite, 0.1 to 0.3% of sodium polyacrylate of molecular weight in the range of 1,000 to 3,000 and 50 to 70%.

10. A liquid detergent as claimed in Claim 9 which comprises 8 to 10% of sodium linearhigheralkylben- zenesulphonate of 12 to 13 carbon atoms in the alkyl group, 1.7 to 2.7% of sodium alkyl polyethoxy sulphate wherein the alkyl group is of 12 to 15 carbon atoms and the polyethoxy is of 3 to 5 ethylene oxide groups, 9 to 13% of sodium tripolyphosphate, 3 to 6% of sodium carbonate, 10to 14% offinelydivided bentonite, of dry and unswelled particle size of about No.325, U.S. Sieve Series (which has openings 44 microns across), 0.1 to 1.2% of sodium polyacrylate of molecularweight in the range of 1.500 to 2,500, and 55 to 70% of water.

11. A liquid detergent as claimed in Claim 10 which comprises about 9% of sodium lineartridecylbenzene sulphonate,about2% of sodium alkyl polyethoxy sulphate wherein the alkyl group is of 12to 15 carbon atoms and the polyethoxy is of about 3 ethylene oxide groups, about 11% of sodium tripolyphosphate, about 4% of sodium carbonate, about 12% of bentonite, about 0.15% of sodium polyacrylate of molecular weight of about 2,000, and about 60% of water.

12. A liquid detergent as claimed in any one of Claims 1 to 11 which comprises about 0.2% of sodium carboxymethyl cellulose and about 0.2% offormalin, and in which the water is deionised water, the density is about 1.25 g/ml and the pH is about 10.5.

13. Afabric softening composition as claimed in Claim 1, substantially as specifically described herein with reference to the examples.