GB2138037A - Heavy duty fabric softening detergent - Google Patents

Abstract

A heavy duty bleaching or whitening and textile softening particulate synthetic organic detergent composition includes a combination of anionic and nonionic organic detergents, a builder or mixture of builders, an oxygen releasing bleaching agent and agglomerated essentially grit-free bentonite of certain particle sizes. Preferred compositions also include higher fatty acid soap, fluorescent brightener, water soluble builder for the anionic detergent, colourant, enzyme and perfume. In such products the agglomerated bentonite will preferably be of larger particle sizes than particles of the other detergent composition components (including particles of mixed components) and may be desirably coloured with a bluing agent. The bentonite employed will be essentially free of gritty particles of material sometimes found with bentonite, as it occurs in nature. Such particles are removable from the bentonite prior to agglomeration, by a described process.

Description

SPECIFICATION Heavy duty fabric softening detergent The present invention relates to detergent compositions. More particularly, it relates to particulate heavy duty laundering and textile softening detergent compositions intended for use in both machine and hand washing of laundry. It also relates to methods for preparing a component of such compositions (essentially grit-free agglomerated bentonite).

Heavy duty detergent compositions useful for machine washing of textiles are everyday household products, widely employed throughout the world in home laundry applications. British Patent Specifications 404,413 and 461,221 disclose that clothes-washing compositions containing bentonite, synthetic anionic detergent and builder salt "give to fabrics washed therewith a full feel and a soft handle". Bentonites have a long history of use in soap and detergent products as fillers and bodying agents and it has also been recognized that fabrics are softened by the deposition of bentonite thereon from aqueous baths; see U.S. Patent 3,594,212.Various such applications of bentonite and other suitable clays have also been described in the more recent patent art, For example, various softening uses are described in British Patent Specificatins No's. 1,404,898; 1,401,726; 1,455,873; 1,460,616; 1,572,815; U.S.

Patents 3,936,537; 4,141,847; and U.K.

Patent Application No. 2,063,289. However, some bentonites do not contain appreciable proportions of exchangeable monovalent metal ions and therefore are not good softeners, and some contain objectionable proportions of gritty material, making them unacceptable in laundry detergents. Nevertheless, by means of the present invention such bentonites can be successfully employed to make softening detergent components and detergent compositions of excellent performance characteristics can be made.

In accordance with the present invention a heavy duty bleaching and textile softening particulate detergent composition for water washing of laundry comprises 3 to 10% of a sodium salt of a synthetic organic anionic sulphonate or sulphate detergent 1 to 8% of a nonionic detergent, 0 to 10% of a water soluble alkali metal soap, 20 to 75% of a builder for the synthetic organic detergent, 5 to 35% of a bleaching agent which releases pxygen in aqueous solution at elevated temperature, and 5 to 25% of agglomerated bentonite of particle sizes in the range of No's. 10 to 100 sieve (U.S. sieve series, which have openings of 2000 microns and 149 microns respectively).In preferred embodiments of the invention the anionic detergent is a sodium linear higher alkylbenzene sulphonate, the nonionic detergent is a condensation product of a higher fatty alcohol and polyethylene oxide, a hydrogenated tallow fatty acids soap is present, the builder salt is primarily pentasodium tripoly-phosphate or NTA (nitrilotriacetic acid as a salt e.g. the sodium salt) or a mixture thereof (with a small proportion of sodium silicate also present) the bentonite is a swelling bentonite of a moisture content of at least 3%, and the bleaching agent is sodium perborate. Also within the scope of the present invention are methods for making essentially grit-free, swelling bentonite agglomerates and detergent compositions containing such bentonite.

The synthetic organic detergent(s) employed will normally be nonionic and anionic in combination, but suitable amphoteric or ampholytic detergents, such as those sold under the Miranol trademark may also be used in conjunction with nonionics and anionics in the present compositions. Cationic detergents, such as the quaternary ammonium halides, e.g. those sold under the Arosurf trademark, can also serve as supplementary fabric softeners in these products but normally will not be used, and if they are present, will not be spray dried with any anionic detergent, due to an undesirable interaction that can take place.

These classes of materials are well known and have been described repeatedly in the detergent art. Because they are not preferred components of the present compositions no further description thereof in this specification is considered to be appropriate.

Various synthetic anionic organic detergents, such as those characterised as sulphonates and sulphates, usually as alkali metal or sodium salts, may be employed, but those considered to be preferable are the linear higher alkylbenzene sulphonates, higher alkyl or fatty alcohol sulphates and higher fatty alcohol polyethoxy or polyethoxylate sulphates. Preferably, in the higher alkyl benzene sulphonates the higher alkyl group is linear and is preferably of 10 to 14 carbon atoms, more preferably 11 to 13, e.g. 12, and the sulphonate is a sodium salt. The alkyl sulphate is preferably a higher fatty alkyl or alcohol sulphate of 10 to 16 carbon atoms, more preferably 1 2 to 14 carbon atoms, e.g.

12, and is preferably also employed as the sodium salt. The higher fatty alcohol polyethoxy sulphates will preferably be of 10 to 18 carbon atoms, more preferably 1 2 to 16, e.g.

12, in the higher fatty alcohol, the ethoxy content will preferably be from 3 to 30 ethoxy groups per mol, preferably 3 or 5 to 20, and the detergent preferably will be a salt of sodium. Thus, it will be seen that the alkyl groups of the sulphonates and sulphates are preferably linear or fatty higher alkyl groups of 10 to 1 8 carbon atoms, the cation is preferably sodium, and when a polyethoxy chain is present the sulphate is preferably at the end thereof. Other useful anionic detergents in dude the higher olefin sulphonates and paraffin sulphonates, e.g. the sodium salts wherein the olefin or paraffin groups are of 10 to 1 8 carbon atoms.Specific examples of the preferred detergents are sodium dodecyl benzene sulphonate, sodium tallow alcohol polyethoxy (3 EtO) sulphate, and sodium hydrogenated tallow alcohol sulphate. In addition to the preferred anionic detergents mentioned, others of this well known group may also be present, especially in only minor proportions with respect to those previously described.

Also, mixtures thereof may be employed and in some cases such mixtures can be superior to single detergents. The various anionic detergents are well known in the art and are described at length at pages 25 to 1 38 of the text Surface Active Agents and Detergents, Vol. Il, by Schwartz, Perry and Berch, published in 1 958 by lnterscience Publishers, Inc.

Although various non ionic detergents of satisfactory physical characteristics may be utilized, including condensation products of ethylene oxide and propylene oxide with each other and with hydroxy-containing aromatic and aliphatic bases, such as nonyl phenol and Oxo-type alcohols, it is highly preferred that the nonionic detergent be a higher fatty alkoxy poly-lower alkoxy lower alkanol, which may also be described as a condensation product of ethylene oxide (and/or propylene oxide) and a higher fatty alcohol. In such products the higher fatty alkoxy or alcohol is of 10 to 1 6 carbon atoms, preferably 12 to 1 5 carbon atoms, and the nonionic detergent contains from about 3 to 20 lower alkoxy groups, preferably 5 to 15, and more preferably 9 to 13 ethylene oxide groups per mol, e.g. 11.

The builder for the synthetic organic detergent, which helps to improve the washing action of the detergent, is either a water soluble or a water insoluble builder or a mixture thereof. Of course, mixtures of water soluble builders may also be utilized, e.g.

polyphosphate and NTA (nitrilotriacetic acid salt, normally the sodium salt), but of the water insoluble builders usually only the zeolites will be present, although mixtures of such zeolites may also be found to be advantageous. While zeolites are useful components of the present compositions, generally it will be preferable to employ water soluble builder(s), and often such will be the only builder(s) present.

The water soluble builder or mixture thereof employed may be one or more of the conventional materials that have been used as builders or suggested for such purpose. These include inorganic and organic builders, and mixtures thereof. Among the inorganic builders those of preference are the various phosphates, preferaly polyphosphates, e.g. tripolyphosphates and pyrophosphates, such as pentasodium tripolyphosphate and tetrasodium pyrophosphate. Trisodium nitrilotriacetate (NTA), preferably employed as the monohydrate, and other nitrilotriacetates, such as disodium nitrilotriacetate, are preferred organic builders. The designation NTA, which normally stands for nitrilotriacetic acid, in this specification is employed to also refer to the various salts thereof, preferably the alkali metal salts and most preferably the trisodium salt.Sodium tripolyphosphate, sodium pyrophosphate and NTA may be utilized in hydrated forms, which are often preferred, but anhydrous forms may also be used. Of course, carbonates, such as sodium carbonate, are useful builders and may desirably be employed, alone or in conjunction with bicarbonates, such as sodium bicarbonate. When the polyphosphates are employed it may be preferred to have sodium pyrophosphate present with sodium tripolyphosphate (STP) in proportion from 1:10 to 10:1, preferably 1:5 to 5:1 with respect to STP, with the total proportion of both builders being about the same as that mentioned herein for the sodium tripolyphosphate.Other water soluble builders that are considered to be effective include the various other inorganic and organic phosphates, borates, e.g. borax, citrates, gluconates, EDTA (ethylene diamine tetracetic acid e.g. as the sodium salt) and iminodiacetates. Preferably the various builders will be in the forms of their alkali metal salts, either the sodium or potassium salts, or a mixture thereof, but sodium salts are normally more preferred. In some instances, as when neutral or slightly acidic detergent compositions are being produced, acid forms of the builders, especially of the organic builders, may be preferable but normally the salts will either be neutral or basic in nature.The silicates, preferably sodium silicate of Na20:SiO2 ratio within the range of 1:1.6 to 1:3.0, preferably 1:2 to 1:2.8, e.g. 1:2.35 or 1:2.4, also serve as builder salts but only relatively small proportions thereof will be present. When it is desired for greater proportions of silicate to be in the detergent composition it may be preferable for hydrated sodium silicate particles to be post-added to spray dried particles containing other builder(s).

The water insoluble builders, as that term is employed in the present specification, are those which help to improve the detergency of synthetic organic detergents, especially that of synthetic anionic organic detergents, and in such cases the mechanism for increasing detergency appears to be related to water softening effects of the builder, such as calcium and/or magnesium ion removal from the wash water, usually by an ion exchange mechanism. While it is within the invention to utilize water insoluble builders other than the zeolites, as a practical matter, at the present time, the zeolites are the principal such insol uble builders that are used.

The zeolites employed include crystalline, amorphous and mixed crystalline-amorphous zeolites, of both natural and synthetic origins.

Preferably, such materials are capable of reacting sufficiently rapidly with calcium ions so that, alone or in conjunction with other water softening compounds in the detergent, they soften the wash water before adverse reactions of such ions with other components of the synthetic organic detergent composition occur. The zeolites employed may be characterised as having a high exchange capacity for calcium ion, which is normally from about 200 to 400 or more milligram equivalents of calcium carbonate hardness per gram of the aluminosilicate, preferably 250 to 350 mg eq/g.

Although other ion exchanging zeolites may also be utilized, normally the finely divided synthetic zeolite builder particles employed in the practice of this invention will be of the formula (Na20),.(A1 203),.(Si02),.w w H20 wherein x is 1, y is from 0.8 to 1.2, preferably about 1, z is from 1.5 to 3.5, preferably 2 to 3 or about 2, and w is from 0 to 9, preferably 2.5 to 6. The zeolite should be a univalent cation-exchanging zeolite, i.e. it should be an aluminosilicate of a univalent cation such as sodium or potassium.

Crystalline types of zeolites utilizable as good ion exchangers in the invention, at least in part, include zeolites of the following crystal structure groups: A, X, Y, L, mordenite and erionite, of which types A, X and Y are preferred. Mixtures of such molecular sieve type zeolites can also be useful, especially when type A zeolite is present. These crystalline types of zeolites are well known in the art and are more particularly described in the text Zeolite Molecular Sieves, by Donald W. Breck, published in 1974 by John Wiley s Sons.

Typical commercially available zeolites of the aforementioned structural types are listed in Table 9.6 at pages 747-749 of the Breck text, which table is incorporated herein by reference. Also, suitable zeolites have been described in many patents in recent years for use as detergent composition builders.

Crystalline zeolites of ion exchanging and water softening properties that are preferred are those which are in hydrated or water loaded form, containing bound water in an amount from about 4% up to about 36% of the zeolite total weight, depending on the type of zeolite used, and are preferably hydrated to about 1 5 to 70% of their capacities.

Normally, water contents are in the range of about 5 to 30%, preferably about 10 or 15 to 25%, such as 17 to 22%, e.g. 20%.

Preferably the zeolite should be in a finely divided state, with the ultimate particle diameters being up to 20 microns, e.g. 0.005 to 0.01 to 20 microns, more preferably being from 0.01 to 1 5 microns, e.g. 3 to 12 microns, and especially preferably being of 0.01 to 8 microns mean particle size, e.g. 3 to 7 microns, if crystalline, and 0.01 to 0.1 micron, e.g. 0.01 to 0.05 micron, if amorphous. Although ultimate particle sizes are much lower, usually the zeolite particles will be of sizes within the range of No's. 100 to 400 sieve (U.S. sieve series, which have openings 149 microns across and 37 microns across respectively), preferably 1 40 to 325 (U.S. sieve series, which have openings 105 microns across and 44 microns across respectively).However, they may sometimes be agglomerated, separately or with spray dried detergent composition particles, to sizes like those of the particles, for example, i 10 or 25%.

Although sodium sulphate and sodium chloride and other filler salts possess no building properties they are sometimes utilized in detergent compositions for their filling characteristics, and sodium sulphate is especially useful as a processing aid. In addition to increasing the volume and weight of the product to facilitate measuring, they also sometimes improve bead stabilities and physical properties of the detergent composition beads in which they are incorporated. Nevertheless, because the present compositions are satisfactory without any fillers being present, such are often avoided entirely or any proportion thereof present may be only minor.

The softening clay that is an important component of the present detergent compositions is of the type characterised as 'bentonite". Bentonites are colloidal clays (aluminium silicates) containing montmorillonite. They are of varying compositions and are obtainable from natural deposits in many countries, including Italy, Spain, U.S.S.R., Canada and the United States (principally Wyoming, Mississippi and Texas). The bentonites which are useful in accordance with the present invention are those which have 'lubricating" and dispersing properties, which appear to be associated with swelling capacity in water. Although some bentonites, principally those which may be characterised as calcium (or magnesium) bentonites, have low or negligible swelling capacities, these may be converted or 'activated" so as to increase such swelling capacity.Such conversion may be effected by appropriate treatment with alkaline material, preferably aqueous sodium carbonate solution, in a manner known in the art, to insert a monovalent metal, such as an alkali metal, e.g. sodium (or potassium), into the clay structure in place of the divalent alkaline earth metal or magnesium. In addition to improving the swelling capacity of the bentonite, which benefits fabric softening and dispersing capabilities thereof, the alkali or alkali metal carbonate solution treatment of the nonswelling clay or poorly flowing clay replaces, for example, 5 to 100%, 10 to 90% or 15 to 50% of the exchangeable calcium and/or magnesium with sodium (or potassium), and thereby improves the exchange capacity of the clay for water hardness ions, such as those of calcium and magnesium.The resulting byproducts, calcium carbonate and magnesium carbonate, are left with the bentonite, and appear to have desirable adjuvant properties in the final products. Any excess sodium carbonate can act as a builder in the final detergent composition.

Although ion exchange capacities of bentonites have been mentioned in the patent literature as being relevant to softening capacity, it is a feature of the present invention that good textile softening is obtainable with sodium bentonites of comparatively low ion exchange capacities. Whether the swelling bentonite (also called sodium bentonite herein because in most cases the exchangeable metal will be sodium) is a naturally occurring clay or is obtained by alkali treatment of a nonswelling or poorly swelling bentonite, it may be used in the present textile softening detergent compositions. Treated Italian bentonites have been found to be especially useful and are considered most appropriate for products intended for European markets.For American markets Wyoming bentonite is often preferable and such does not have to be treated because it already contains sodium ion in the bentonite structure and has swelling properties. Analysis of a typical Italian bentonite (after alkali treatment) shows that it may contain 66.2% of Sio2, 17.9% of Al 203, 2.80% of MgO, 2.43% of Na20, 1.26% of Fe203, 1.15% of CaO, 0. 14% of TiO2 and 0. 13% of K20.A typical Wyoming or western bentonite (untreated) may contain from from 64.8 to 73.0% of SiO2, 14 to 18% of Awl203, 1.6 to 2.7% of MgO, 0.8 to 2.8% of Na2O, 2.3 to 3.4% of Fe203, 1.3 to 3.1% of CaO and 0.4 to 7.0% of K2O. Thus, it is seen that the compositions of the bentonites are quite different although both types have swelling properties.It is considered that if the Na2O content of the clay is at least about 0 5%, preferably at least 1 % and more preferably at least 2% (the equivalent proportion of K20 may also be taken into account), the clay will be satisfactorily swelling for the purposes of the present invention, with satisfactory softening and dispersing properties in aqueous suspension (the swelling of the bentonite facili- tates breakup of the bentonite agglomerate).

While it is expected that proportions of the various constituents of the swelling bentonites (which may herein be referred to as sodium bentonites, whether natural or "activated") within the ranges between the typical analyses given will result in useful components of the present compositions, it is also considered that the percentages of the components of the natural swelling bentonite may be raised or lowered about 10% thereof and typical analyses of the treated bentonites may be expanded + 10%, with the bentonites within those ranges still being useful. Additionally, other swelling bentonites may be substituted, at least in part. Generally, the useful bentonites will have swelling capacities of at least 1 or 2 millilitres per gram, more preferably at least 5 or 10 ml/g. Of course, higher swelling capacity bentonites will also be useful.Normally the range of swelling capacities will be from 5 to 30 ml/g and frequently will be in the 5 to 20 ml/g range.

The sodium bentonite or swelling bentonite preferably will be agglomerated before being blended with spray dried built detergent beads and any other adjuvants to be postadded. Such agglomeration will be carried out in known manner, as by utilizing a water or aqueous binder spray application to tumbling bentonite powder, extrusion, compaction, pan agglomeration or other technique. However, it is highly desirable that the bentonite be in finely divided powder form before agglomeration so that, when the agglomerate breaks up in the wash water, the particles of bentonite will be small enough to be effective lubricants, as deposited on the laundry. Thus, it will normally be desirable for essentially all of the bentonite powder, before agglomeration, to pass through a No. 100 sieve (U.S.Sieve Series which has openings 149 microns across), with at least 99% passing such a sieve and with over a major proportion thereof passing through a No. 200 sieve (U.S. Sieve Series, which has openings 74 microns across), preferably with less than about 30% by weight of the particles failing to pass through such a sieve and more preferably with no more than 20% resting on such sieve. Of course, the ultimate particle sizes are lower.

Also important to promote ready break-up of bentonite agglomerates and dispersion in the wash water, so that the minute particles thereof may be adhered to textile fibres to soften them, is the moisture content of the bentonite. Although it is desirable to limit the free moisture content of the bentonite utilized to about 10% or so, with moisture contents above 15% not normally being employed, it is even more important to make certain that the bentonite includes enough free moisture, much of which is considered to be present between adjacent plates of the bentonite, to facilitate quick disintegration of the bentonite and any adjacent materials in the particles when such particles or detergent compositions containing them are brought into contact with water, such as wash water. It has been found that at least about 2%, preferably at least 3% and more preferably, about 4% or more of water should be present in the bentonite (socalled "internal" moisture), and that the bentonite should not be dried so that less than such percentages of water are even temporar ily present in it. In other words, overdrying to the point where the bentonite loses its internal moisture can significantly diminish the utility of the present compositions. When the bentonite moisture content is too low the bentonite does not aid in satisfactorily swelling and disintegrating the agglomerated beads in the wash water.

Preferred swelling bentonites of the types described above are sold under the trade names Laviosa and Winkelmann, e.g. Laviosa AGB and Winkelmann G 13, both of which are treated Italian bentonites, and Mineral Colloid No. 101 (and other similar designations) corresponding to Thixo-Gels No's. 1, 2, 3 and 4 (marketed by Benton Clay Company, an affilitate of Georgia Kaolin Co.). As will be described later, the treated bentonites will also preferably be essentially free of grit, preferably having been further processed by grinding to a fine powder before agglomeration. Usually the commercial bentonite used wil have a pH in water (at 6% concentration) in the range of 8 to 9.4, a maximum free moisture content of about 8%, a specific gravity of about 2.6 and a viscosity, at 10% concentration in water, within the range of 5 to 30 centipoises, preferably 10 to 30 cp.

The water soluble soap, which is a desirable component of the present detergent compositions and which has a useful foam limiting action in the wash water, which is especially advantageous for side loading or horizontal tub washing machines, is normally a higher fatty acid soap of an alkali metal, such as sodium or potassium, with sodium soaps being highly preferred. Such soaps are well known and need not be described at length.

Suffice it to say that they may be made from natural fats and oils, such as those from animal fats and greases and from vegetable and seed oils, for example, tallow, hydrogenated tallow, coconut oil, palm kernel oil, and corresponding "natural" and synthetic fatty acids, and that they are normally of 10 to 24 carbon atoms, preferably 14 to 1 8 carbon atoms. Preferably such soaps are of hydrogenated tallow or hydrogenated tallow fatty acids, e.g. stearic acid. The water soluble soap which may be included in the present compositions will preferably be chosen so as to have a desirable balance of good detergent properties, effective foam reducing effect and other good physical properties.Specifically, among those other physical properties will be desirable hardness, good binding effect and little or no tendency to produce adhesive gels under use conditions (as in the washing machine charging compartment).

Bleaching agents are usually incorporated in all of the detergent compositions of this invention intended for use in automatic washing machines of the "European design", which utilize very hot water (near the boil), because under such conditions effective and safe bleaching occurs, leading to desirably whiter laundered items. When the wash water temperature in the automatic washing machine is high enough sodium perborate is the bleaching agent of choice because the elevated temperature, especially when it is above 80"C, e.g. 90 or 95"C, can cause decomposition of the perborate and release of bleaching oxygen from it.Thus, under such conditions the sodium perborate, which is often referred to as sodium perborate tetrahydrate or sodium borate perhydrate, and which will usually have an active oxygen content of at least about 10%, releases such oxygen without the need for employment of an activating agent or decomposition catalyst. When lower temperature automatic laundering is undertaken, or if the product is intended for use outside the washing machine, either in cold water or hot water, for example, at temperatures from 20"C to 60"C, the sodium perborate will not usually sufficiently decompose to satisfactorily bleach textiles being washed and in such circumstances an activator will be employed or another suitable bleaching agent will be used, also usually with an activator.

Many such systems have been described in the literature, most of which belong to the class of peroxygen compounds, such as persulphuric acid, peracetic acid, performic acid, perphthalic and perbenzoic acid, and salts thereof, such as the alkali metal and alkaline earth metal salts, e.g. sodium or magnesium salts. Various activators for such compositions are known which promote the controlled release of oxygen from them in hot and cold water systems. Included among such activators are heavy metal salts, such as copper salts, and various inorganic and organic compounds, which have been described in the art.

Among the lower temperature bleaches that which is preferred is magnesium dimonoperoxyphthalate. Of course, various other oxygen releasing bleaching materials, such as the hydroperoxides, may be employed and in the proper circumstances chlorine releasing bleaching materials can be incorporated in the present detergent compositions. While, in some instances, it may be considered to be unnecessary to incorporate a bleach in the detergent composition, normally such will be employed. Especially in the present compositions, including agglomerated bentonite particles, the perborate may exert a whitening effect on sometimes off-colour bentonite, which otherwise may be very noticeably off-colour, due to its larger agglomerated particle size. When the agglomerated bentonite is coloured intentionally the per-compound can help to "purify" the colour by removing the off-colour of the base.

Various adjuvants may be present in the crutcher mix from which base beads or detergent compositions may be spray dried, or such adjuvants may be post-added, with the decision as to the mode of addition often being determined by the physical propoerties of the adjuvant, its resistance to heat, its resistance to degradation in the aqueous crutcher medium, and its volatility. Among the adjuvants often employed are enzyme powders or prills, which normally are postadded to the base beads because they are heat sensitive. These may be any of a variety of commercially available products, included among which are Alcalase (Registered Trade Mark), manufactured by Novo Industri, A/S, and Maxatase (Registered Trade Mark), both of which are alkaline proteases (subtilisin).

Among specific enzyme preparations that may be employed are Novo Alcalase 2M (2 Anson units per gram) and Maxatase P 440,000.

Although the alkaline proteases are most frequently employed, amylolytic enzymes, such as alpha-amylase, may also be utilized. These enzyme compositions usually contain active enzymes in combination with an inert powdered vehicle, such as sodium or calcium sulphate, and the proportion of active enzyme may vary widely, usually being from 2 to 80% of the commercial preparation. In this specification proportions referred to are of the enzyme preparations, not the active part thereof.

Among the fluorescent brighteners those most commonly employed are the stilbene brighteners, e.g. Tinopal 5 BM, especially in extra concentrated form. Among the stilbene compounds are cotton brighteners, such as those sometimes referred to as CC/DAS brighteners, derived from the reaction product of cyanuric chloride and the disodium salt of diaminostilbene disulphonic acid, including variations thereof with respect to substituents on the triazine and aromatic rings. This class of brighteners is known in the detergent art and will most often be used when bleaching components are not present in the final product. When it is desired for the detergent composition to include a bleach, such as sodium perborate or other oxidizing bleach, bleach stable brighteners may be incorporated in the crutcher mix.Among these there may be mentioned the benzidine sulphone disulphonic acids, naphthotriazolyl stilbene sulphonic acids and benzimidazolyl derivatives.

Polyamide brighteners, which also may be present, include aminocoumarin or diphenyl pyrazoline derivatives, and polyester brighteners, which can also be used, include naphthotriazolyl stilbenes. Such brighteners are normally-used as their soluble salts, e.g. sodium salts, but they may be charged as the corresponding acids. The cotton brighteners will usually comprise major proportions of the brightener systems employed.

When it is desired that the product made be entirely or partially coloured, various suitable dyes and dispersible pigments may be employed. When blue dyes, such as Acilan blue, or pigments, such as ultramarine blue, are utilized they have their dual effects of serving to colour some or all of the detergent composition particles, or particles of components of the detergent composition, and helping to give the washed laundry a desirable bluish tint. Colouring of agglomerated bentonite particles by suitable dyes or pigments may be especially desirable because natural bentonite sometimes may be off-colour, so that the agglomerates may be converted from particles that look dirty to those which are of attractive colour and appearance.

Perfumes employed, which are usually heat sensitive and may contain volatile constituents, including a solvent, such as alcohol or a suitable glycol or polyol or hydrocarbon, are normally of synthetic perfumery materials, sometimes mixed with natural components, and generally will include alcohols, aldehydes, terpenes, fixatives and/or other normal perfume components, known in the art.

In addition to the adjuvants mentioned there may also be present flow promoting agents, anti-setting materials employed to prevent premature gelation of the crutcher mix, dispersion aids, anti-redeposition agents and, in some cases, additional softening agents, e.g. cationic softeners such as the quaternary ammonium halides, e.g. dimethyldioctadecyl ammonium chloride. However, as was indicated previously, normally the cationic softening agents will not be employed and if used, they will be post-added.

Of course, water is present in the crutcher from which the spray dried component of the present composition is made, wherein it serves as a medium for dissolving or dispersing the various components of the spray dried beads. Therefore, some water, in both free and hydrate forms, is in the product. Similarly, water may be employed to agglomerate the bentonite and perborate powders. While it may be preferred to employ deionized water, so that the hardness ion contents thereof may be very low and so that metallic ions that can promote decomposition of any organic materials which may be present will be minimized, city or tap water may be utilized instead and sometimes, for economic or supply reasons, will be used exclusively. Normally the hardness content of such water will be not greater than about 300 parts per million, as calcium carbonate.

The proportions of the various components in the final product of this invention will be such as to result in it being effective as a free flowing, effectively cleaning, whitening, fabric softening detergent. The proportion of anionic detergent will normally be from 3 to 10% of the final product, preferably 3 to 7% and more preferably 4 to 6%, e.g. 5%. Usually the nonionic detergent content will be from 1 to 8%, preferably 2 to 5%, e.g. 3 or 4%. The builder content will generally be in the range of 20 to 75%, preferably 30 to 50% (and such is often preferably entirely water soluble builder salt) and more preferably 30 to 40%, e.g. about 35%. As was previously indicated, sodium tripolyphosphate and NTA are preferred water soluble builders, which may be the sole builders employed.When they are utilized in admixture the mixture will preferably contain from 10 to 90% of one of them, with the balance being the other such builder, and within such ranges preferred proportions may be 20 to 80% and 40 to 60%, and complementing percentages. Similar ranges of percentages are applicable when the builder is a mixture of water soluble builder salt and water insoluble builder, such as a zeolite.

The bentonite content of the textile softening detergent, in the form of an agglomerate of more finely divided bentonite powder particles, will be a satisfactorily softening proportion thereof, which usually will be within the range of 5 to 25%, preferably 10 to 20%, more preferably 14 to 18%, e.g. about 16%.

The proportion of bleaching agent will be within the range of 5 to 35%, preferably 1 5 to 25%, e.g. 20%. However, it will be kept in mind that such proportions are based on employment of sodium perborate and will be modified when other oxidizing agents are utilized, so as to have approximately the same bleaching effect (or active oxygen content).

When a fatty acid soap is present the proportion thereof will usually be no greater than 10%. A preferred range of soap contents is from 2 to 6%, more preferably from 2 to 4%.

The moisture content of the product, which does not include hydrate moisture which is not removable during the standard heating at 105"C for two hours, will usually be within the range of 3 to 20%, with the higher percentages thereof being permissible when a substantial proportion, at least 1/4 and preferably at least 1/2 of the moisture, is in hydrate form. A preferred moisture content is from 5 to 17% and a more preferred such content is from 10 to 15%, e.g. 10%. Any moisture not removable by the standard test mentioned above is considered to be a part of the compound in which it is present as a hydrate, e.g. a zeolite.

The total proportion of various adjuvants which may also be present in the detergent composition will usually be no more than 20%, preferably being limited to 15% and more preferably to 10%. Because water soluble sodium silicate has building properties, especially with respect to its action against magnesium ions in hard water, its proportion is included within the total builder content.

However, because it also acts as a binder the proportion thereof present will be mentioned herein, with other adjuvants for the present composition. Usually it will constitute no more than 8% of the product, with a normal range of 1 to 5%, preferably 2 to 4%, e.g. 35.

Sometimes, to improve flowability, especially when the silicate content exceeds 3 or 4%, the balance will be post-added, as a hydrous silicate. The content of filler salt, such as sodium sulphate, when it is present, will also normally be limited, to no more than 10%, and will normally constitute from 0.5 to 5%, preferably 0.5 to 2%, e.g. 1 or 1.5% of the product. The percentage of proteolytic enzyme used will normally be from 0.1 to 2%, preferably 0.2 to li, e.g. 0.3%, and the percentage of optical brightener dye will be from 0.1 to 2%, preferably 0.1 to 0.5%, e.g. about 0.2%. Perfume content will normally be from 0.05 to 2%, preferably 0.1 to 1, and more preferably 0.2 to 0.5%, e.g. about 0.3%.

Among other adjuvants it may sometimes be desirable to have present small proportions of particular sequestering agents and flow promoters. Among such materials a preferred sequestrant is diethylenetriamine pentaacetic acid, magnesium salt (magnesium DTPA) but other diethylenetriamine acetates may be substituted for it. Magnesium silicate is a preferred flow promoter, which also may serve as a carrier for the sequestrant. Commercially, a mixture of such products is available comprising 15% of the magnesium DTPA and 85% of MgSiO3 and when such is employed the proportion thereof is preferably from 0.1 to 1%, more preferably 0.1 to 0.5%, e.g. 0.2%.

Proportions of the sequestrant (or stabilizer) may be from 0.01 to 0.2%, preferably 0.02 to 0.1 %, and for the MgSiO3 concentrations are in the range of 0.1 to 0.9%, preferably 0.2 to 0.5%. Amounts of other adjuvants employed will be such as to accomplish the purpose for which the adjuvant is included in the detergent composition but normally such proportions will not be in excess of 1 to 2% and frequently will be within the range of 0.05 to 1%.

In addition to the detergent composition containing synthetic organic detergent, builder, bentonite, and bleach, and soap and adjuvants, also within the present invention are detergent compositions wherein the bentonite is one from which objectionable grit has been removed and also, preferably, it is one which had been converted to an alkali metal bentonite, such as sodium bentonite, by treatment of a bentonite containing a replaceable magnesium and/or calcium content, with an alkali, such as sodium carbonate solution. The bentonite used is characterised as essentially grit-free, which means it contains less than 1 % of gritty particles.The essentially grit-free bentonite utilized will normally contain less than 0.4% of palpable hard gritty particles, which are water insoluble and which are difficult to smash when placed on a hard surface and struck by a normal hammer blow. More preferably less than 0.1 % of such grit will be present, and such bentonite may be called grit-free. In the crude bentonite, as mined, the grit content may be as high as 15%, in some instances, although usually it will be less than 5%. Processing of the bentonite to remove the grit therefrom will be carried out in conjunction with treating it to increase the exchangeable monovalent cation content, which will preferably be raised to at least 2% (as Na2O) by such treatment.Details of the treatment method and its advantages will be given below when the process aspects of the present invention are discussed.

To make the products of this invention, known spray drying, agglomerating and mixing techniques (preferably all three) may be employed. Because such are not considered to be significant features of the invention they will be referred to only briefly herein. In the spray drying operation a crutcher mix containing various components desired to be present in the spray dried bead and sufficiently stable to withstand the crutching and spray drying operations, such as detergent, builder and suitable adjuvants, is spray dried from an aqueous crutcher mix, which normally will contain from about 40 to about 70 to 75% of solids, preferably 50 to 65% thereof, with the balance being water.The crutcher mix may contain the anionic detergent and a portion or all of the nonionic detergent, although usually no more than 5% of nonionic detergent (on the basis of the final product) will be in the crutcher (the rest, if any, being post-added).

All of the builder or mixture of builders will normally be added in the crutcher, although this is not necessary. The bentonite powder is separately agglomerated and is post-added to the spray dried product, often as a coloured (preferably blue) bead. Aqueous silicate solution, stable fluorescent brightening dye, soap and filler salt are usually added in the crutcher, together with any stable pigment and other colourants that may be employed.

Instead of charging a neutralized detergent, the crutcher may be utilized as a neutralizing vessel, in which anionic organic detergent acid is neutralized with aqueous caustic. Such acid, for example, may be dodecylbenzene sulphonic acid containing about 45 to 50% of active ingredient, which may be neutralized with an aqueous sodium hydroxide solution, such as one containing 38% of Na2O. If the detergent acid is made by sulphonating the alkylbenzene with sulphur trioxide the active ingredient content of the acid may be as high as 99%. A higher fatty acid mixture may also be neutralized in the crutcher with the detergent acid to produce a desired higher fatty acid soap-detergent mixture.

The crutcher mix may be spray dried in a conventional spray tower, utilizing either concurrent or countercurrent flow. Normally the mix will be at a temperature in the 20 to 80"C range, preferably 40 to 70"C and will be spray dried in a tower in which the drying air is at a temperature of 200 to 400"C, to produce spray dried beads of particle sizes in the range of No's. 10 to 100 sieves (U.S.

Sieve Series). Any particles that are outside the desired range may be removed by screening and may be reprocessed. The beads thus made have a bulk density in the range of 0.3 to 0.6 g/ml, e.g. 0.5 g/ml. They are of a moisture content in a range which may be as broad as about 3 to 20% but normally will be about 10 to 15%.

After production of the spray dried portion of the compositions other components thereof may be mixed with the beads or sprayed onto them (and onto other components of the product, when desired). Generally it will be preferred for the bentonite, enzyme, bleach, and any other particulate products, such as those in powder, agglomerate or prill form which are intended to be post-added to the spray dried beads, to be mixed with them, after which any liquids to be post-added may be sprayed onto the mixture. However, orders of post-addition of components may be varied and sometimes part of the particulate material may be post-added after one or more of the liquids. Two or more of the particulate materials may be pre-mixed before post-addition and similarly, mixtures of liquids may also be made.

Solvents may be employed for various components to be applied as liquids and in some cases emulsions may be employed. In some instances it may be desirable to extend the perfume with a suitable solvent, such as a comparatively odourless alkylate (hydrocar- bon). When nonionic detergent is post-added (and it will sometimes be preferred that all of the nonionic detergent be added in the crutcher) it may be sprayed onto or otherwise satisfactorily applied to the surfaces of the spray dried beads before admixing with the other particulate components. Also, as previously indicated, the nonionic detergent, in liquid form, may be mixed with the perfume to be sprayed onto the product, in which case it may act like an emulsifier.

The apparatus for effecting the various mixings and sprayings is known in the art and accordingly will not be described in detail herein Spraying may be through conventional nozzles, usually of wide spray pattern design, but other types of spraying equipment may also be employed. The mixers may be of various designs but preferably include revolving inclined tubes or drums, inside which spraying may be effected. However, the Vshaped blenders, especially those of continuous feed design, and other commercial powder blends can also be satisfactory.

The various mixing and spraying operations will normally take place at about room temperature but operations in the range of 10 to 40"C, preferably 20 to 30"C, are preferred.

The particle sizes of the materials being mixed will usually be like those of the final product, within the No's. 10 to 100 or 200 sieve (U.S. Sieve series) range (the perborate and enzyme ranges may extend to No. 200). The agglomerated bentonite particles will be those resulting from agglomeration or compaction of more finely divided particles, such as those of which over 50% pass through a No. 200 sieve (U.S. Sieve Series, which has openings 74 microns across). Such particles will be essentially grit-ffree sodium bentonites. They may be sprayed with a suitable dye or pigment, such as Acilan Brilliant Blue FFR and various other suitable colourants may be applied. Sometimes the bentonite agglomerates may be larger than the other particles in the product, e.g. 10 to 50% greater in diameter, to accentuate their difference.Although western or Wyoming bentonites may be used to make the agglomerates, in many instances the bentonite agglomerates will preferably be of sodium carbonate treated bentonite (such treatment improves the colour of off-colour clay) and will contain magnesium carbonate and/or calcium carbonate theren, resulting from such treatment.

The sodium carbonate treatment of the crude bentonite will be undertaken when the content of exchangeable sodium in the bentonite is lower than desirable for satisfactory softening and agglomerate-dispersing action of the bentonite when the agglomerated beads thereof are added to the wash water.

For bentonite containing exchangeable calcium and/or magnesium and insufficient exchangeable sodium, e.g. less than 0.5% as sodium oxide, the crude clay, with contained grit in many cases, is ground or otherwise broken up and is treated with suitable alkali, such as aqueous sodium carbonate which can be of a concentration in the range of 5 to 20%. After contact with the clay for a suitable time, which may be from 1/2 hour to 24 hours, the mix, which still contains some free excess sodium carbonate (normally 10 to 50% excess to replace the exchangeable calcium and magnesium will be employed), is dried. Usually such dried material, often in large cakes, with a moisture content in the range of 2 to 15%, is broken up and then ground to particulate form, with the particles being of diameters in the range of 0.8 to 8 mm.In such state the bentonite may be sold commercially for those applications in which grit content is un-important. However, when the bentonite contains objectionable quantities of grit it is next further size reduced, to particles less than No. 100 sieve (U.S. Sieve Series, which has openings 149 microns across) in size and with at least 50% thereof less than 200 sieve (U.S. Seive Series, which has openings 74 microns across). These are then subjected to centrifugal separation or other density responsive separation technique, e.g. gravitational settling, but preferably a cyclone separator is employed. The grit is removed and the concentration thereof in the product is decreased to below 2%, e.g. below 0.4%.Subsequently, the bentonite, now essentially grit-free and with sufficient exchangeable sodium to be a useful component in the softening detergent products of this invention, is agglomerated to particles in the desired size range, by a suitable method, such as one previously described herein.

The products and processes of this invention possess many advantages, several of which have already been mentioned. With respect to the products, the detergent compositions resulting are excellent whitening laundry detergents and effectively soften washed laundry, as has been established by comparative tests against similar compositions which do not contain bentonite. The products are satisfactorily free flowing, non-dusting and of desired bulk density and attractive appearance. The bentonite tends to make the washed laundry feel softer to the touch but does not produce objectionable hydrophobic properties in the laundered materials. It has been shown that bentonite can sometimes even increase the moisture absorption rates of fabrics, and it acts as a builder for detergents and may contribute soil suspending properties.For example, it appears that nine parts of bentonite are the equivalent of about one part of sodium tripolyphosphate, as a builder for organic detergents. Apparently because of its plate-like structure the ultimate bentonite particles, which become held to the fibres of laundry, act to lubricate such fibres and thereby make them feel soft. Because the particles are so small in size and apparently are of desirable optical characteristics, they do not objectionably lighten or discolour the fabrics to which they are adherent, and deposits thereof do not accumulate on the fabrics to an objectionable extent despite repeated washings with bentonite-containing detergent compositions.

The bentonite agglomerates dissociate readily in the wash water, especially in very hot wash water, and this dissociation may be assisted by oxygen release from the bleaching agent, such as sodium perborate. The agglomerates can be water absorbing, with respect to the per-compound, without becoming cemented to other particles in the detergent composition, at least when only relatively small amounts of external moisture are present. In this respect the bentonite agglomerates can help to stabilize the per-compound and help to prevent caking of such materials and the spray dried beads, in which most of the other components of the product are present.While it may sometimes be desirable for the perborates and enzyme to be coated with other materials, so as to stabilize them and prevent their interaction with other detergent composition components, in the present compositions this has not been found to be neces sary. Furthermore, with the bentonite in the agglomerated particles, which do not contain the other product components, it is more available for moisture absorption, and apparently has a greater anti-caking effect than would be the case if it had been spray dried with the other detergent components. Also, when bentonite is spray dried with other detergent composition components it may lose some of its softening power, and this often makes the present invention preferable. Nevertheless, in some instances it may be desirable to utilize a portion of the bentonite, e.g.

up to half thereof, in the crutcher mix, in which case it will be present in the spray dried beads and may assist in disintegrating them rapidly in the wash water. However, it has been found that such spray dried beads which do not contain bentonite sufficiently rapidly dissociate, when they are of the particle sizes mentioned herein, so that no "internal" bentonite is required. The perborate, detergent and builder components apparently can interact with the bentonite in preparing the sites on the laundry fabric for the softening particles. Those sites are thereby physically and chemically cleaned, which can improve their holding powder for the bentonite.

Thus, it is seen that the various components of the present compositions may interact so as to improve the softening, cleaning and whitening effects thereof.

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.

EXAMPLE 1 A crutcher mix totalling 100 parts is made by reacting 11.38 parts of Dobane JNQ (which contains 48.8% active ingredient which is dodecylbenzene sulphonic acid) and 5.22 parts of hydrogenated fatty acids (16 to 18 carbon atoms per mol of fatty acid) with 1.47 parts of caustic soda (38% Na2O) in an aqueous medium containing a suitable proportion (to maintain the reaction) of 29.75 parts of city water (300 p.p.m. hardness, as CaCO3). The balance of such water is employed to cool the reaction mix, as desirable, and to dilute other components of the crutcher mix.Subsequently there are added to the crutcher 7.56 parts of aqueous sodium silicate solution Na2O:SiO2 = 1:2.4) at a 44.1% solids concentration, 0.23 part of fluorescent stilbene type brightener, 0.22 part of Sydex 808 (85% MgSiO3 and 15% magnesium DTPA), 39.14 parts of hydrated sodium tripolyphosphate (TPP "H"), 1.69 parts of anhydrous sodium sulphate (99.5% pure) and 33.34 parts of a nonionic detergent which may be considered as the condensation product of 11 mols of ethylene oxide with one mol of higher fatty alcohol having 12 to 1 5 carbon atoms per mol.

The crutcher mix is heated for about an hour, with stirring, so that its temperature rises to about 55"C, after which it is pumped to a spray drying tower where it is sprayed at elevated pressure through multiple spray nozzles into drying air at a temperature of about 300"C. Particles of a moisture content of about 12% result, most of which are within the No's 10 to 100 sieve range (U.S. Sieve Series, which have openings 2000 microns (2 mms) and 149 microns across respectively).

Particles outside this range are screened out.

63.1 Parts of the spray dried powder (bulk density of about 0.4 g/ml) are then blended with 0.3 part of prilled proteolytic enzyme (Alcalase, of 2 Anson units per gram, although Maxatase P 440,000 may be subtituted), 20 parts of granular sodium perborate and 16 parts of agglomerated bentonite. All such powders are of particle sizes within the particle size range for the spray dried detergent composition component but smaller particles of the enzyme and perborate may also be employed, down to about No. 200 (U.S.

Sieve Series which has openings 74 microns across). The bentonite particles are composed of 82.3 parts of anhydrous bentonite, 16.1 parts of water, 1.5 parts of sodium silicate (previously described) and 0.06 part of Acilan Brilliant Blue dye, with the dye being applied to the surface of the particles. The bentonite particles are made by agglomeration of more finely divided particles of bentonite (Laviosa AGB) with the dilute sodium silicate solution (in the water), after which they are dyed. The bentonite employed is one which has been treated with sodium carbonate to replace calcium and magnesium therein with sodium and from which a natural content of gritty material has been removed, after treatment, by centrifugal separation. Such processing methods for the bentonite will be described subsequently in this example. The moisture content of suitable agglomerated bentonite may be varied and can be as low as 3%, when mixed with other components of the present softening detergent.

Onto the mixture of spray dried beads, enzyme, perborate and coloured bentonite particles, in an inclined drum mixer, there are sprayed 0.5 part of the nonionic detergent and 0.25 part of detergent perfume. The spraying is regulated so that the sprayed liquid evenly coats the particles in the mixer or tumbling drum to produce about 100 parts of uniform product.

The final product is of particle sizes within the range of No's. 10 to 60 sieve (U.S. Sieve Series, which have openings 2000 microns and 250 microns across respectively), a bulk density of about 0.5 g/ml and a moisture content of about 12% (although on standing this may be reduced to about 8 to 10% e.g.

9%). The particulate fabric softening detergent resulting is non-dusting, free flowing and attractive in appearance, with somewhat larger (averaging 20 to 200% greater in diameter) blue agglomerated bentonite particles contrasting with the other white particles.

While the spray dried beads and the bentonite agglomerates are distinct, the perborate and enzyme, especially when particles thereof are of sizes at the low end of the range mentioned, may appear to blend with the other beads, thus improving enzyme appearance.

However, they are not agglomerated and if not separate, are readily separable from the other such particles and from each other.

When the product described is subjected to practical laundry testing it is found to be an excellent detergent with desirable fabric softening properties.

In modifications of the above procedure the anionic detergent is replaced by equal weights, respectively, of sodium lauryl sulphate, sodium hydrogenated tallow alcohol sulphate and sodium tallow alcohol polyethoxy (3EtO) sulphate. Alternatively, mixtures of such materials, e.g. equal parts of sodium dodecylbenzene sulphonate and sodium hydrogenated tallow alcohol sulphate, are employed together. In all such cases the final detergent composition resulting is one which is an excellent textile softening laundry detergent.Similar results are also obtainable when, instead of the anionic detergent being varied, the nonionic detergent is changed, being replaced by a block copolymer of propylene oxide and ethylene oxide, such as Pluronic L44 or L-62, nonyl phenol poly-oxyethylene (12 EtO) glycol or a condensation product of C12-15 fatty alcohol with 3 or 7 mols of ethylene oxide per mol, or with a mixture of two or more of such detergents, e.g. in equal parts. When half or all of the sodium tripolyphosphate is replaced by NTA the final product is also a satisfactory detergent, with softening properties.

When the soap is omitted from the formula diminished foam control results but otherwise the product is acceptable and is like those previously described. When the sodium perborate is replaced by other bleaching agents, such as sodium per-sulphate, sodium perisophthalate or magnesium di-monoperoxyphthalate, good bleaching and cleaning by the product is still obtainable. When the bleach is omitted the detergent composition obtained does not whiten laundry or remove stains as well. When known activators for oxidizing agents are present bleaching may be effected by use of the composition at lower temperatures than those near the boil (which are normally employed in the processes of this example to obtain maximum bleaching activity).When it is desired to include more silicate in the product the amount of silicate is doubled by post-adding similarly sized hydrous sodium silicate particles with the other postadded particulate solids. In a processing variation only the perfume is sprayed onto the mix, with the nonionic detergent all being incorporated in the crutcher.

The bentonite agglomerates employed in this example are substantially regular spheres consisting essentially of bentonite with a small proportion of silicate binder and with a bluing colourant on the surface thereof. To make them, an Italian clay, low in exchangeable sodium, is processed to increase the sodium content, swelling capacity and softening-effects. First, such clay, containing a minor proportion, e.g. about 3%, of hard, black gritty mineral, is crushed and size reduced so that the particles thereof pass through a No. 4 sieve (U.S. Sieve Series which has openings 4760 microns (4.76 mms) across), after which they are treated with an excess e.g.

50% excess, of sodium carbonate solution, such as one at a concentration of about 10%.

The mix is allowed to stand, with intervening periods of mixing, for a suitable time for reaction, such as about four hours, at which point sufficient ion exchange has occurred between the exchangeable calcium and magnesium of the clay so that a typical analysis thereof is that given for Italian bentonite (after alkaline treatment) earlier in this specification.

By such treatment the Na2O content of the clay has been increased significantly (about 2%) and the MgO and CaO contents have been diminished by corresponding proportions. The clay is then dried, for example to a moisture content of about 5%, after which it is size reduced to particles that are desirably less than No. 100 sieve (U.S. Sieve Series which has openings 149 microns across) (although sometimes larger sizes of particles may be present) and is subjected to centrifugal air separation in a cyclone separator (although size-separating techniques may also be employed) to remove the grit.The grit-free bentonite, containing less than 0.1 % of grit, having a swelling capacity of about 5 ml/g and being of a viscosity of about 1 5 centipoises, at 6% concentration in water, and of a moisture content of about 7%, is next agglomerated by the method described earlier herein, with the dilute sodium silicate solution being sprayed onto the surfaces of the moving particles while they are being tumbled in an inclined drum. Tumbling is continued until the particles are of the desired size range and are satisfactorily rounded. At the end of the tumbling period, which may last for up to an hour, on the average, a dilute dye solution is sprayed onto the beads to colour them, and they are ready for mixing with the other components to make a final detergent product.

EXAMPLE 2 An effective softening detergent like that of the first formula of Example 1 is made from a crutcher mix of 10.24 parts of the dodecylbenzene sulphonic acid, 2.81 parts of the hydrogenated fatty acid, 0.81 part of the caustic soda, 26.54 parts of water, 37.2 parts of pentasodium tripolyphosphate (hydrated), 6.8 parts of the sodium silicate solution, 0.21 part of fluorescent brightener, 1.46 parts of sodium sulphate and 3.0 parts of the nonionic detergent, added sequentially. This is spray dried by the method described in Example 1 to produce 62.5 parts of a product of similar bulk density and particle size.The spray dried particles are then mixed with 0.3 part of proteolytic enzyme, 20.0 parts of the sodium perborate granules, 16.0 parts of the agglomerated bentonite and 0.2 part of Sydex 808, and onto the tumbling powder mix there is sprayed a blend of 0.3 part of the detergent perfume and 0.4 part of C,0-13 linear alkylate.

When, instead of employing an agglomerated sodium carbonate-treated Italian bentonite from which grit has been removed, as in Example 1, a competitive grit-free swelling clay product (Winkelmann agglomerate) or a Wyoming type bentonite, such as that sold under the trade name Mineral Colloid No.

101 (formerly Thixogel No. 1) is employed, similar final products are obtained which are good softening detergents. When the Acilan Blue dye, used to colour the bentonite agglomerates, is replaced by ultramarine blue, good colouring and bluing effects are also obtained.

EXAMPLE 3 When the proportions of the various components in the preceding Examples are modified i 10%, i 20% and + 30%, maintaining them within the ranges previously given and keeping the ratios of anionic detergent to nonionic detergent within the range of about 1:1 to 3:1, the ratio of total detergent content to builder content within the range of about 1:3 to 1:8 and the ratio of sodium bentonite to total detergent within the range of about 1:1 to 2:1, products of properties similar to those described in Example 1 are obtained.

Such is also the case when the water soluble builder salt(s) of Example 1 are replaced with zeolite A (20% hydrated) and when any of a variety of synthetic anionic and nonionic detergents is employed in admixture, optionally with an amphoteric detergent, such as one of the Miranol type. Also, the bentonite agglomerate detergent composition and its components may be of different densities (0.2 to 0.9 g/ml) and sizes (No. 10-40 sieve (U.S. Sieve Series, 10 mesh having openings 2000 microns across and 40 mesh openings 420 microns across).

Claims (51)

1. A heavy duty bleaching and textile softening particulate detergent composition for water washing of laundry which comprises 3 to 10% of a sodium salt of a synthetic organic anionic detergent which is a sulphonate or sulphate detergent or a mixture thereof, 1 to 8% of a nonionic detergent, 0 to 10% of a water soluble alkali metal soap, 20 to 75% of a builder for the synthetic organic detergent, 5 to 35% of a bleaching agent which releases oxygen in aqueous solution at elevated temperature, and 5 to 25% of agglomerated bentonite of particle sizes in the range of No's. 10 to 100 sieve (U.S. Sieve Series which have openings 2000 microns (2 mms) across and 149 microns across respectively).

2. A detergent composition as claimed in Claim 1 in which the sodium salt of the anionic detergent is a sodium linear higher alkylbenzene sulphonate in which the higher alkyl group is of 10 to 14 carbon atoms, a sodium higher fatty alcohol sulphate in which the higher fatty alcohol is of 10 to 16 carbon atoms, or a sodium higher fatty alcohol polyethoxy sulphate wherein the higher fatty alcohol is of 10 to 18 carbon atoms and which contains from 3 to 20 ethoxy groups per mol, or a mixture thereof.

3. A detergent composition as claimed in Claim 1 or Claim 2 which comprises from 3 to 7% of sodium linear higher alkylbenzene sulphonate in which the higher alkyl group is of 11 to 1 3 carbon atoms.

4. A detergent composition as claimed in Claim 1, 2 or 3 in which the higher alkyl group of the sodium linear higher alkyl benzene sulphonate is a dodecyl group.

5. A detergent composition as claimed in Claim 1, 2, 3 or 4 comprising about 5% of sodium linear dodecyl benzene sulphonate.

6. A detergent composition as claimed in any one of Claims 1 to 5 in which the nonionic detergent is a higher fatty alkoxy poly-lower alkoxy lower alkanol wherein the higher fatty alkoxy group is of 10 to 16 carbon atoms and the lower alkoxy and lower alkanol groups are of 2 to 3 carbon atoms and which contains from 3 to 20 lower alkoxy groups per mol.

7. A detergent composition as claimed in any one of Claims 1 to 6 in which the nonionic detergent comprises 2 to 5% of a higher fatty alkoxy poly-lower alkoxy lower alkanol wherein the higher fatty alkoxy group is of 12 to 1 5 carbon atoms, the lower alkoxy and lower alkanol groups are of 2 carbon atoms, and the molar ratio of higher fatty alkoxy to lower alkoxy is from 1:5 to 1:15.

8. A detergent composition as claimed in any one of Claims 1 to 7 in which the nonionic detergent is a condensation product of a higher fatty alcohol of 12 to 1 5 carbon atoms and 9 to 13 mols of ethylene oxide per mol of higher fatty alcohol.

9. A detergent composition as claimed in any one of Claims 1 to 8 in which the nonionic detergent is about 3% of higher fatty alkoxy poly-lower alkoxy lower alkanol no nionic detergent wherein the higher fatty alkoxy group is of 12 to 1 5 carbon atoms, the lower alkoxy and lower alkanol groups are of 2 carbon atoms and the molar ratio of higher fatty alkoxy to lower alkoxy is about 1:11.

10. A detergent composition as claimed in any one of Claims 1 to 9 in which the soap is a soap of higher fatty acids of 10 to 24 carbon atoms per mol.

11. A detergent composition as claimed in any one of Claims 1 to 10 in which there is 2 to 6% of sodium soap of higher fatty acids of 14 to 18 carbon atoms per mol.

12. A detergent composition as claimed in Claim 11 in which the soap is a sodium soap of hydrogenated tallow fatty acids.

1 3. A detergent composition as claimed in Claim 12 in which the soap is about 5% of sodium soap of hydrogenated tallow fatty acids.

14. A detergent composition as claimed in any one of Claims 1 to 1 3 in which the builder-is a water soluble or a water insoluble builder or a mixture thereof.

1 5. A detergent composition as claimed in any one of Claims 1 to 14 in which the builder is 30 to 50% of water soluble builder salt.

16. A detergent composition as claimed in any one of Claims 1 to 1 5 in which the builder salt is primarily of pentasodium tripolyphosphate.

1 7. A detergent composition as claimed in Claim 1 6 in which the builder is about 35% of hydrated pentasodium tripolyphosphate.

1 8. A detergent composition as claimed in any one of Claims 1 to 1 7 in which the bleaching agent is sodium perborate.

1 9. A detergent composition as claimed in Claim 18 in which the bleaching agent is 1 5 to 25% of sodium perborate.

20. A detergent composition as claimed in Claim 1 9 in which the bleaching agent is about 20% of sodium perborate.

21. A detergent composition as claimed in any one of Claims 1 to 20 in which the bentonite particles are in the form of agglomerated particles produced after sodium carbonate treatment of bentonite containing magnesium and/or calcium to replace such magnesium and/or calcium with sodium, with resulting magnesium carbonate and/or calcium carbonate present with the bentonite in the particles.

22. A detergent composition as claimed in any one of Claims 1 to 21 in which the pentonite is an agglomerate of smaller particles of ground sodium bentonite from which accompanying grit has been removed after grinding and before agglomeration.

23. A detergent composition as claimed in any one of Claims 1 to 22 in which the bentonite swells in water, having a swelling capacity of at least 1 ml/g.

24. A detergent composition as claimed in any one of Claims 1 to 23 in which the bentonite is of a swelling capacity in the range of 5 to 30 ml/g.

25. A detergent composition as claimed in any one of Claims 1 to 24 in which the bentonite has a viscosity, in 10% dispersion in water, of 5 to 30 centipoises.

26. A detergent composition as claimed in any one of Claims 1 to 25 in which the bentonite is of a moisture content of at least 3%.

27. A detergent composition as claimed in any one of Claims 1 to 26 in which the bentonite is sodium bentonite.

28. A detergent composition as claimed in any one of Claims 1 to 27 in which 10 to 20% of bentonite is present in the composition.

29. A detergent composition as claimed in Claim 28 in which 16% of bentonite is present in the composition.

30. A detergent composition as claimed in any one of Claims 1 to 29 in which the particles are of sizes within the range of No.lO to No. 100, U.S. Sieve Series (which have openings 2000 microns and 149 microns across respectively).

31. A detergent composition as claimed in any one of Claims 1 to 30 in which the sodium higher alkyl benzene sulphonate, soap and builder salt are together in substantially homogeneous particles spray dried from the same crutcher mix, the sodium perborate is in separate or separable particles and the bentonite is in separate particles.

32. A detergent composition as claimed in any one of Claims 1 to 31 in which the agglomerated bentonite particles are of average particle sizes greater than the average particle sizes of the spray dried particles and the perborate particles.

33. A detergent composition as claimed in any one of Claims 1 to 32 in which the bentonite particles are differently coloured from the detergent particles and from the perborate particles so that they are readily identifiable in the detergent composition.

34. A detergent composition as claimed in any one of Claims 1 to 33 containing 1 to 5% of sodium sulphate, 0.1 to 2% of optical brightener dye and 0.1 to 1 % of proteolytic enzyme.

35. A detergent composition as claimed in any one of Claims 1 to 34 containing about 3% of sodium silicate, about 0.3% of proteolytic enzyme, about 0.6% of perfume, about 0.2% of optical brightener and about 9% of moisture.

36. A detergent composition as claimed in Claim 1 in which the sodium salt of the anionic detergent is a sodium linear higher alkylbenzene sulphonate in which the higher alkyl group is of 10 to 14 carbon atoms, a sodium higher fatty alcohol sulphate in which the higher fatty alcohol is of 10 to 16 carbon atoms, or a sodium higher fatty alcohol polyethoxy sulphate wherein the higher fatty alcohol is of 10 to 18 carbon atoms and which contains from 3 to 20 ethoxy groups per mol, or a mixture thereof, the nonionic detergent is a higher fatty alkoxy poly-lower alkoxy lower alkanol wherein the higher fatty alkoxy group is of 10 to 16 carbon atoms and the lower alkoxy and lower alkanol groups are of 2 to 3 carbon atoms and which contains from 3 to 20 lower alkoxy groups per mol, the soap is a soap of higher fatty acids of 10 to 24 carbon atoms per mol, the builder is a water soluble or a water insoluble builder or a mixture thereof, the bleaching agent is sodium perborate and the bentonite is of a moisture content of at least 3% and swells in water, having a swelling capacity of at least 1 ml/g.

37. A detergent composition as claimed in Claim 36 which comprises from 3 to 7% of sodium linear higher alkylbenzene sulphonate in which the higher alkyl group is of 11 to 1 3 carbon atoms, 2 to 5% of a higher fatty alkoxy poly-lower alkoxy lower alkanol wherein the higher fatty alkoxy group is of 1 2 to 1 5 carbon atoms, the lower alkoxy and lower alkanol groups are of 2 carbon atoms, and the molar ratio of higher fatty alkoxy to lower alkoxy is from 1:5 to 1:15, 2 to 6% of sodium soap of higher fatty acids of 14 to 18 carbon atoms per mol, 30 to 50% of water soluble builder salt, 15 to 25% of sodium perborate and 10 to 20% of sodium bentonite.

38. A detergent composition as claimed in Claim 37 in which the particles are of sizes within the range of No. 10 to No. 100, U.S.

Sieve Series (which have openings 2000 microns and 149 microns across respectively), the sodium higher alkyl benzene sulphonate, soap and builder salt are together in substantially homogeneous particles spray dried from the same crutcher mix, the sodium perborate is in separate or separable particles and the bentonite is in separate particles.

39. A detergent composition as claimed in Claim 38 in which the higher alkyl group of the sodium linear higher alkyl benzene sulphate is a dodecyl group, the nonionic detergent is a condensation product of a higher fatty alcohol of 1 2 to 1 5 carbon atoms and 9 to 1 3 mols of ethylene oxide per mol of higher fatty alcohol, the soap is a sodium soap of hydrogenated tallow fatty acids, the builder salt is primarily of pentasodium tripolyphosphate and the bentonite particles are in the forms of agglomerates produced after sodium carbonate treatment of bentonite containing magnesium and/or calcium to produce sodium bentonite, with resulting magnesium carbonate and/or calcium carbonate present with the bentonite in the particles.

40. A detergent composition as claimed in Claim 39 which comprises 1 to 5% of sodium sulphate, 0.1 to 2% of optical brightener dye and 0.1 to 1 % of proteolytic enzyme, in which the agglomerated bentonite particles are of average particle sizes greater than the average particle sizes of the spray dried particles and the perborate particles, and are differently coloured so that they are readily identifiable in the detergent composition.

41. A detergent composition as claimed in Claim 40 in which the sodium bentonite is of a swelling capacity in the range of 5 to 30 ml/g and of a viscosity, in 10% dispersion in water, of 5 to 30 centipoises, and is an agglomerate of smaller particles of ground sodium bentonite from which accompanying grit has been removed after grinding and before agglomeration.

42. A detergent composition as claimed in Claim 41 comprising about 5% of sodium linear dodecyl benzene sulphonate, about 3% of higher fatty alkoxy poly-lower alkoxy lower alkanol anionic detergent wherein the higher fatty alkoxy group is of 12 to 1 5 carbon atoms, the lower alkoxy and lower alkanol groups are of 2 carbon atoms and the molar ratio of higher fatty alkoxy to lower alkoxy is about 1:11, about 5% of sodium soap of hydrogenated tallow fatty acids, about 20% of sodium perborate, about 16% of sodium bentonite, about 3596 of hydrated pentasodium tripolyphosphate, about 3% of sodium silicate, about 0.3% of proteolytic enzyme, about 0.6% of perfume, about 0.2% of optical brightener and about 9% of moisture.

43. A detergent composition as claimed in Claim 1 in which the bentonite particles are in the form of agglomerated particles produced after sodium carbonate treatment of bentonite containing magnesium and/or calcium to replace such magnesium and/or calcium with sodium, with resulting magnesium carbonate and/or calcium carbonate present with the bentonite in the particles.

44. A detergent composition as claimed in Claim 43 in which the sodium bentonite agglomerate is of a swelling capacity in the range of 5 to 30 ml/g and of a viscosity, in 6% dispersion in water, of 5 to 30 centipoises, and is an agglomerate of smaller particles of ground sodium bentonite from which accompanying grit has been removed after grinding and before agglomeration.

45. A detergent composition as claimed in Claim 1 substantially as specifically described herein with reference to the examples.

46. A method of making a heavy duty bleaching and textile softening particulate detergent composition for water washing of laundry, containing 3 to 10% of the sodium salt of a synthetic organic anionic detergent or mixture selected from the group consisting of sulphonates and sulphates, 1 to 8% of a nonionic detergent, 0 to 105 of a water soluble alkali metal soap, 20 to 75% of a builder for the synthetic organic anionic detergent, 5 to 35% of a bleaching agent which releases oxygen in aqueous solution at elevated temperature, and 5 to 25% of agglomerated bentonite, which comprises A) treating a bentonite clay containing magnesium and/ or calcium and grit with sodium carbonate to convert at least some of the calcium and/or magnesium present therein to sodium, with magnesium carbonate and/or calcium carbonate resulting therefrom accompanying the sodium bentonite produced, size reducing the resulting product, removing grit therefrom, agglomerating the grit-less product, B) spray drying a crutcher mix comprising the sodium salt of synthetic organic anionic detergent, soap, if present, and builder, and C) mixing the bleaching agent in particulate form and the agglomerated bentonite with the spray dried particles resulting from step B, steps A and B being carried out in any order or at the same time.

47. A method as claimed in Claim 46 in which the agglomerated bentonite particles are larger than the spray dried detergent composition particles, and the agglomerated bentonite particles are coloured blue so as to be distinguishable from the detergent and bleaching agent particles and so as to have a bluing effect on laundry washed with the detergent composition.

48. A method of making a heavy duty textile softening particulate detergent composition for water washing of laundry, containing a detersive proportion of synthetic organic detergent selected from the group consisting of anionic and nonionic detergents, a building proportion of a builder for the synthetic organic anionic detergent, and a fabric softening proportion of agglomerated bentonite, which comprises size reducing bentonite with accompanying grit, separating the size reduced bentonite from the grit by a size or density dependent separation process, agglomerating the separated grit-free bentonite to particle sizes in the range of No's. 10 to 100 (U.S.

Standard Sieves which have openings 2000 microns across and 1 49 microns across respectively) and mixing the bentonite particles with spray dried particles which include the synthetic detergent and builder and which are of sizes about in the same range as that for the agglomerated bentonite.

49. A method of making agglomerated bentonite particles suitable for mixing with spray dried particles containing a synthetic organic detergent selected from the group consisting of anionic and nonionic detergents, and a builder for the anionic detergent, to make textile softening detergent compositions, which comprises size reducing naturally occurring bentonite containing an exchangeable divalent metal selected from the group consisting of calcium and magnesium, and mixtures thereof, reacting it with an alkali to replace at least some of such divalent metal with a monovalent metal selected from the group consisting of sodium and potassium, drying the resultant bentonite, size reducing it, with the gritty material therein, subsequently separating the bentonite from the gritty material and agglomerating the bentonite to a particle size in the range of No's. 10 to 100 (U.S.

Standard Sieve which has openings 2000 microns and 149 microns across respectively).

50. A method as claimed in Claim 48 substantially as specifically described herein with reference to the Examples.

51. A method as claimed in Claim 49 substantially as specifically described herein with reference to the Examples.