Single use laundry detergent package

NON-AQUEOUS LIQUID CLEANING COMPOSITION AND METHOD OF USE, AND PACKAGE THEREFOR

Background of the Invention (1) Field of Invention

This invention relates to non-aqueous liquid fabric-treating compositions. More particularly, this invention relates in one aspect to nonaqueous liquid laundry detergent compositions which are rendered stable against phase separation and gelation by incorporation of organophilic clay and are easily pourable and to the use of these compo10 sitions for cleaning soiled fabrics. In another aspect, this invention relates to unitary dispenser packages for non-aqueous liquid fabric treating compositions, especially low- or no-phosphate built heavy duty liquid laundry detergent compositions.

(2) Discussion of Prior Art

Liquid non-aqueous heavy duty laundry detergent compositions are well known in the art. For instance, compositions of that type may comprise a liquid nonionic surfactant in which are 20 dispersed particles of a builder, as shown for instance in U.S. Patents Nos. 4,316,812; 3,630,929; 4,264,466; 4,615,820 and 4,661,280.

Liquid detergents are often considered to be more convenient to employ than dry powdered or 25 particulate products and, therefore, have found substantial favor with consumers. They may have one or more of the following advantages: readily measurable; speedily dissolved in the wash water; easily applied in concentrated solutions or dispersions to soiled areas on garments to be laundered; non-dusting; occupy less storage space; may incorporate heat-sensitive materials. Liquid detergents often have certain inherent disadvantages, too, for example, some such products separate out on storage and others separate out on cooling and are not readily redispersed; the product viscosity may change and become either too thick to pour or so thin as to appear watery. Some clear products become cloudy and others gel on standing.

It is known that such suspensions can be stabilized against settling by adding inorganic or organic thickening agents or dispersants, such as, for example, very high surface area inorganic materials, e.g. finely divided silica, clays, etc., organic thickeners, such as the cellulose ethers, acrylic and acrylamide polymers, polyelectrolytes, etc. However, increases in suspension viscosity are limited by the requirement that the liquid suspension be readily pourable and flowable, even at low temperature. Furthermore, these additives do not contribute to the cleaning performance of the formulation.

It is known that aqueous swelling colloidal clays, such as bentonite and montmorillonite clays, can be modified by exchange of the metallic cation groups with organic groups, thereby changing the hydrophilic clays to organophilic clays. The use of such organophilic clays as gel-forming clays has ΐ

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been described in U.S. Patent 2,531,427 to E. A. Hauser. Improvements and modifications of the organophilic gel-forming clays are described, for example, in the following U.S. Patents: 4,105,578, 4,208,218, 4,287,086, 4,434,075, 4,434,076, all assigned to NL Industries, Inc. According to these NL patents, these organophilic clay gellants are useful in lubricating greases, oil based muds, oil base packer fluids, paints, paint-varnish-lacquer removers, adhesives, sealants, inks, polyester gel coats and the like. However, use as a stabilizer in a non-aqueous liquid detergent composition for laundering fabrics has not been suggested.

The use of clays in combination with quaternary ammonium compounds (often referred to as *QA compounds) to impart fabric softening benefits to laundering compositions has also been described, for instance, British Patent Application GB 2,141,152 A, published December 12, 1984, to P. Ramachandran.

According to U.S. Patent 4,264,466 to Carleton, et al., the physical stability of a dispersion of particulate materials, such as detergent builders, in a non-aqueous liquid phase is improved by using as a primary suspending agent an impalpable chain structure type clay, including sepiolite, attapulgite, and palygorskite clays. The patentees state and the comparative examples in this patent show that other types of clays, such as montmorillonite clay, e.g. Bentolite L, hectorite clay (e.g. veegum T) and kaolinite clay (e.g., Hydrite PX), even when used in conjunction with an auxiliary suspension aid, including cationic surfactants, inclusive of qa compounds, are only poor suspending agents.

It has now been discovered, and this forms one aspect of the invention, that by adding to the non5 aqueous liquid suspension a small amount of an organophilic modified clay, an elastic network structure is provided and enhances the cohesiveness of the suspension which, together with the natural tendency of the finely divided solid suspended particles to flocculate, is effective to inhibit settling of the suspended solid fabric treating particles, e.g. detergent builder, bleaching agent, antistatic agent, etc.

Accordingly, in this aspect the present invention provides a liquid heavy duty laundry composition composed of a suspension of a detergent builder salt in a liquid nonionic surfactant wherein the composition includes an amount of organophilic clay to increase the stability of the suspension.

According to a specific embodiment of this aspect of the invention there is provided a heavy duty non-aqueous liquid nonionic laundry detergent composition which includes a non-aqueous liquid composed of a nonionic surfactant, fabric-treating solid particle suspended in the non-aqueous liquid, and an amount up to about 1% by weight of an organophilic water-swellable smectite clay modified with a cationic nitrogen containing compound including at least one long chain hydrocarbon having from about 8 to about 22 carbon atoms to form an elastic network or structure throughout the suspension to increase the yield stress of the composition to thereby increase its stability, i.e. prevent settling of suspended particles, preferably while reducing or at least without significantly increasing, the plastic viscosity (viscosity under shear conditions) of the composition.

To some extent instability or viscosity problems, particularly as they may be perceived by the consumer, may be partially or completely solved, by incorporating the detergent composition in a unitary package. By unitary package is meant a single use disposable package having therein an amount of fabric treating composition appropriate for a single full or partial (e.g. 1/4 or 1/2) load of laundry. For instance, for a unitary package separation of phases may not be so significant since the entire package and content may be added to the washing machine.

There have been many proposals for unitary packages for fabric treating compositions. Prepackaged detergent compositions provide several advantages, such as eliminating the need to measure and dispense measured quantities of bulk detergent from a large container, less dusting, less handling of potentially irritating ingredients, such as high alkalinity, bleach components, and so on.

Representative patent art relating to unitary packages for dispersing powdery, liquid or paste fabric treating or other types of compositions in aqueous media includes U.S. Patents 3,186,869; 3,277,009; 3,322,674; 3,528,925; 3,892,905; 4,115,292; 4,348,293; 4,356,099; 4,416,791;

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4,608,187; 4,610,799; 4,626,372 and Canadian Patent 1,112,534.

Clarke, et al., in U.S. Patent 4,348,293, describe a package for powdery detergent comprising an outer water-insoluble, water-permeable bag and a water-soluble or dispersible protective inner layer. The package may be in the form of a laminate or as separate sheets, properly folded to encase the powdery detergent. The protective inner layer being essentially non-porous, avoids dusting of the powder composition during the bag filling operation and during use of the package.

For liquid detergent formulations, e.g. suspensions of detergent builder particles in liquid nonionic surfactant, although dusting may not be a problem, nevertheless the liquid phase of the composition, especially for liquid formulations of relatively low viscosity, e.g. below about 10,000 centipoise, may leak through the protective inner layer or through any imperfectly formed seams or seals. The same is true, although to a lesser extent, for more viscous liquids, pastes, gels and creams.

It has now been found, according to another aspect of this invention, that a double wall bag construction may be adapted to any of these pourable low viscosity, high viscosity, paste, gel or cream non-aqueous liquid detergent compositions by proper selection of the material of the watersoluble or dispersible protective inner layer which will avoid leakage of the non-aqueous liquid phase but which will still dissolve or disperse in cold, warm or hot wash water within a reasonably short period of time to release their content into the wash water.

Therefore, according to another aspect, the invention provides a single use disposable package for dispensing a non-aqueous built liquid laundry detergent composition wherein the package comprises a multicomponent sachet including an outer bag fabricated from water-insoluble, water-permeable non-woven fabric, and an inner bag fabricated from a film of water-soluble or dispersible, liquid impermeable material which is heat-sealable at least along the outer edges.

A potential problem of the double wall bag construction is that when the outer waterinsoluble, water-permeable bag is sufficiently porous to allow rapid penetration of the wash bath water into the interior of the package to dissolve the inner water-soluble bag and release the detergent composition, if the bag is stored under high humidity conditions, or accidentally comes into contact with water, the inner water-soluble bag may be prematurely dissolved or weakened to allow leakage of the liquid contents. Therefore, in a preferred embodiment of this aspect of the invention, there is provided a third outermost removable layer or envelope of water-insoluble water-impermeable material to protect the watersoluble inner bag from exposure to or contact with moisture, including atmospheric moisture, and/or dirt or other potentially contaminating soil or debris.

As stated above, by providing the liquid detergent compositions in unitary packages, problem of phase separation, gelling and so on may not be perceived by the consumer and, therefore, may not appear to require special stabilizing systems or other precautions during manufacture. Nevertheless, product stability is an important consideration for the manufacturer since in many cases there may be substantial delays in time between the bulk formulation of the product and the packaging thereof into the unitary doses. Also, the bulk formulations may be made at one location and packaged at a second remote location. In either case, it is important to maintain the product as homogeneous as possible from the time the composition is first formulated until it is filled into the individual packages. It is also important that the physical characteristics of the detergent compositions, such as viscosity, gel formation, agglomeration of suspended solid particles, are not substantially changed or caused to occur over time, such as during storage, shipping or in the course of the filling operation. Any such changes in physical characteristics could seriously adversely impact on the filling operation and filling apparatus and could lead to over- or underfilling of the packages, clogging of the filling nozzles or similar problems.

Therefore, in accordance with a preferred embodiment of the invention, applicable to both of the above aspects, the non-aqueous heavy duty built laundry detergent composition is formulated with appropriate rheology modifiers, including one or more of viscosity modifiers, antigelling agents and physical stabilizers, in addition to the essential liquid detergent component and suspended solid particles, preferably comprising detergent builder 5 salt and other optional functional or aesthetic laundry detergent additives.

The washing power of synthetic nonionic surfactant detergents in laundry detergent compositions is increased by the addition of 10 builders. Sodium tripolyphosphate is one of the preferred builders. However, the use of polyphosphate builders in detergents does involve several disadvantages such as, for example, the tendency of the polyphosphates to hydrolyse into 15 pyro- and orthophosphates which represent less valuable builders.

In addition, the polyphosphate content of laundry detergents has been blamed for the undesirably high phosphate content of surface water 20 which is believed to contribute towards greater algae growth with the result that the biological equilibrium of the water can be adversely altered.

Thus, in accordance with another and specific aspect of this invention there is provided a 25 detergent product which comprises a double wall sachet including a water-soluble liquid impermeable inner layer surrounding a non-aqueous liquid detergent composition and a water-insoluble, waterpermeable bag surrounding the inner layer, the 30 liquid detergent composition comprising a no- or low-phosphorus non-aqueous liquid laundry detergent composition which includes a non-aqueous liquid composed of nonionic liquid surfactant, fabric treating solid particles suspended in the nonaqueous liquid, and an amount effective to reduce the product's viscosity and lower its gelling temperature of an alkylene glycol monoalkyl ether solvent, wherein at least 50% by weight of the fabric treating solid particles are comprised of a salt of hydroxy polycarboxylic acid as detergent builder.

In a preferred embodiment of this aspect the present invention provides a detergent product comprising a liquid heavy duty laundry composition composed of hydroxy polycarboxylic acid detergent builder salt stably suspended in a liquid nonionic surfactant and an alkylene glycol alkyl ether solvent in an amount to make the suspension pourable even at temperatures as low as 5°C or below, the liquid composition being packaged in a sachet comprising a closed water-insoluble, water20 permeable outer bag and an inner layer of a watersoluble liquid impermeable material separating the liquid composition from the outer bag, and, preferably surrounding the outer bag, a removable envelope of water-insoluble water-impermeable material to protect the water-soluble inner bag from exposure to or contact with moisture and dirt prior to adding the sachet to an aqueous wash bath.

Detailed Description of Invention and preferred Embodiments

The non-aqueous liquid detergent compositions according to this invention include a non-aqueous liquid phase composed of a liquid nonionic surfactant as at least the major component, and optionally, but preferably one or more viscosity modifying and gel-inhibiting organic solvents, and suspended in the liquid phase, finely divided fabric-treating or detergency-enhancing solid particles.

According to the first aspect of this invention the stability of the suspended solid particles is enhanced by incorporating in the composition an effective amount, usually up to about 1% by weight of the composition, of an organophilic clay. The organophilic clay comprises a swelling smectite clay modified with a nitrogencontaining compound including at least one longchain hydrocarbon having from about 8 to about 22 carbon atoms.

According to the second aspect of the invention the non-aqueous liquid detergent composition, with or without the organophilic clay stabilizing agent, is provided in a unitary package formed from a sachet having an outer layer of a water-permeable water-insoluble plastic film or textile fabric, an inner layer within the outer layer formed from a water-soluble polymer film forming material, the liquid fabric treating composition being sealed within the inner layer in an amount of from about 50 to 150 grams.

In the third aspect of this invention, a nonaqueous low- or no-phosphate heavy duty built liquid fabric treating composition is used in the unitary package as described above for the second aspect of the invention, and comprises, based on the total composition, on a weight basis, at least 20% of liquid nonionic surfactant, at least 20% of alkali metal hydroxypolycarboxylic acid salt having from 4 to 8 carbon atoms, and lower alkylene glycol alkyl ether solvent in amount sufficient to lower the viscosity and gelling temperature of the composition such that the composition remains pourable at temperatures at least as low as 5°C.

In accordance with the second and third aspects of the invention, and, optionally also the first aspect, a non-aqueous liquid laundry detergent, preferably one that is readily pourable, is pre-packaged in premeasured dosage forms for single use in discardable packets or sachets.

A multicomponent disposable sachet dispenser is used of the type generally disclosed in U.S. Patent 4,348,293 to Clarke, et al. Certain details relating to the bag construction, materials and fabrication, can be found in the Clark, et al. patent. Accordingly, only the preferred embodiments and unique features of the multicomponent sachets to be used in this invention are described. The sachet dispenser includes an outer pouch or bag of a waterpermeable or porous water-insoluble film or fabric and an inner pouch or bag of a water-soluble or dispersible, liquid impermeable film. The inner bag is filled with the appropriate unit dosage of the non-aqueous liquid detergent composition and is then sealed. The outer bag is sealed around the inner bag which may be free floating therein, i.e. not attached to the walls of the outer bag, or it may be sealed to one or more edges or walls thereof by any suitable means, such as adhesives, heat sealing, staples, sewing, etc. In use in the aqueous wash bath the water from the bath permeates or flows through the outer bag and contacts the inner bag which then dissolves upon exposure to the water and exposes the detergent composition to the wash water inside the pouch and allows the fabric treating detergent, detergent builder, and so on, to permeate out of the outer bag to the aqueous wash bath. In this way, the invention composition can be gradually introduced into the wash bath during the wash cycle, preferably over the course of one or more minutes, for example, within 1 to 5 minutes, such as about 2 to 3 minutes. Although the nonwater-soluble outer bag can be fabricated from a perforated water-insoluble material, e.g. resin impregnated paper, wax paper, viscose, polyolefin film, polyester film, etc. it is preferred to form the outer bag from non-woven textile fabric using fibers of natural or synthetic origins or mixtures thereof. Non-woven polyester fabrics of density ranging from about 10 to 40 grams per square meter, preferably 15 to 30 grams per square meter, especially 18 to 24 grams per square meter have proven effective in practice.

Another preferred material for the outer bag is highly porous spun-bonded non-woven polypropylene. The fabric density may be the same as described for the non-woven polyester fabrics.

Other suitable fiber materials include, for example, polyamides, polyacrylics, polyolefins, such as polyethylene, polypropylene, ethylenepropylene copolymers, etc., polyvinyl chloride, 5 polyvinylidene chlorine, rayon, cellulose and the like.

It has been found convenient for most product formulations to use from about 50 to 150 grams of the detergent composition, preferably 60 to 120 10 grams, such as 70, 80, 90, 100 or 110 grams, per wash, this amount conveniently fitting in a single sachet dispenser, measuring, for example, from about 3 to 4 or more inches per side, such as 3.5 in. or 3.75 in. or 4 in. per side.

Polyvinyl alcohol having a degree of hydrolysis of at least 60%, preferably 80 to 100%, such as 85 to 98%, e.g. 88% is preferably used as the water-soluble film or sheet for forming the water-soluble liquid impermeable inner bag of the 20 sachet. Other water-soluble films or sheets can also be used. For example, mention may be made of polyethylene oxide, methyl cellulose, gelatine, polysaccharides, polyacrylic acid and the like.

In order to make the water-soluble film material impervious to the non-aqueous liquid phase it is important that it be non-porous and such nonporous films are readily commercially available. Furthermore, the film material should have suitable thickness. Generally, depending on the nature of 30 the water-soluble film material thicknesses of at least about 4 mil (.004 inch), preferably at least 10 mil will be selected. On the other hand the film should not be so thick as to require excessively long periods for dissolution after placement in the wash bath. Therefore, thickness up to about 100 mil, preferably up to about 50 mil will be selected.

Another important factor for selection of suitable water-soluble film-forming material to obtain the required impermeability to the nonaqueous liquid phase while still having acceptable dissolution properties is the molecular weight of 10 the film. For instance, in the case of polyvinyl alcohol films a molecular weight of about 40,000 provides fast dissolution rates, even in cold water, but could be partially permeable to the nonaqueous liquid phase. Polyvinyl alcohol films with 15 molecular weight of about 80,000 are non-permeable to the non-aqueous liquid phase and require longer periods to dissolve in cold water, but rapidly dissolve in warm water (about 30°C or higher) . Therefore, for liquid detergent compositions to be 20 acceptable for use with cold wash water, polyvinyl alcohol films with molecular weights of from about 45,000 to about 75,000 are preferred although lower or higher molecular weights may be acceptable. For use under warm water conditions higher molecular 25 weights, e.g. from about 60,000 to 100,000 offer acceptable dissolution rates and good liquid impermeability.

Appropriate molecular weight ranges can be easily determined for other water-soluble film 30 forming materials and for any particular nonaqueous liquid detergent composition by routine experimentation.

As an alternative to the use of water-soluble films for the inner protective bag layer it is possible to use perforated films of waterinsoluble materials with the perforations filled or blocked with a water-soluble substance, such as any of the water-soluble substances mentioned above. The holes, or perforations, can cover, for example, from about 20 to 80% of the total area of one or both major sides of the inner bag and may conveniently range from about 1/8 square inch to about 1/2 square inch in area. The perforations can be in any desired geometrical configuration and array, e.g. circular perforations in a square pattern, star-shaped perforations in a circular pattern, etc.

The use of a double wall sachet wherein the outer wall is formed of a sealed water-insoluble water-permeable material has several advantages. The water-insoluble outer bag can protect the water-soluble inner bag from exposure to moisture, e.g. humidity, during storage, but being waterpermeable will allow exposure of the water-soluble film and liquid detergent product to the aqueous wash bath so that the detergent and fabric treating ingredients can be dispersed to the fabrics during the wash cycle. Furthermore, because the outer bag of the sachet is and remains sealed during the washing, rinsing, and spin-dry operations of the washing machine, any residue of the water-soluble inner bag will be substantially retained within the sachet rather than being deposited on the fabric being laundered. For instance, portions of the partially hydrolyzed polyvinyl acetate may be waterinsoluble and form clumps upon dissolution of the water-soluble portions. These clumps will be substantially retained within the water-insoluble outer bag. Also, it may in some case be advantageous to render the inner bag partially water-insoluble, for example, by a wax coating, to enhance storage stability. This wax coating will also be retained within the permeable but insoluble outer bag of the 10 sachet.

However, it has been found that, in practice, effective and convenient means for protecting the water-soluble inner bag and its liquid content from premature exposure to moisture, whether water vapor 15 in humid environments, or accidental contact with water or soil during storage, shipment or during use and handling by the consumer, is simply to provide a removable protective water-insoluble waterimpermeable wrapper as the outermost layer of the 20 sachet.

Any water-insoluble water-impermeable (e.g. non-porous) film forming material can be used for this purpose. For example, mention may be made of polyolefin films, polyester films, polyvinyl 25 chloride films, polyvinylidene chloride and other polymer materials, water-resistant papers, wax papers, metal foil, e.g. aluminum foil, and the like. In this context, the water-insoluble waterimpermeable protective outermost wrapper is to be 30 distinguished from the removable water-insoluble protecting agent as used in the aforementioned U.S. Patent 4,348,293 which is applied as a coating to the water-insoluble water-permeable film and which depends on being dispersed in the wash bath for removal.

Thus, the outermost wrapper may be formed in 5 any convenient structure which permits its easy removal by the consumer. For example, baggie-type (e.g. PVDC) pouches may be used with the open end temporarily closed by a tie string, or by a lock fit, or peelable adhesion. Alternatively, the heat 10 sealable plastic materials may be heat sealed along all open edges (e.g. all four edges when two separate film sheets are used or along three edges when a single film sheet is folded on itself) and provided with a frangible score line, or notched at 15 one edge to allow easy tearing. Biaxially oriented polypropylene film is easily tearable and is highly waterproof. When metal foil is used as the outermost protective wrapper it too may be temporarily sealed by any convenient means, such as 20 by adhesive, or the metal foil may be simply securely folded upon itself according to well known means.

By virtue of the outermost protective waterproof wrapper the detergent product may be 25 stored under high humidity conditions or may be otherwise exposed to water without causing premature dissolution of the inner water-soluble bag or leaking of the liquid detergent composition.

In addition to its protective function against 30 exposure to moisture, the outermost protective wrapper also protects the water-permeable outer bag from contact with ambient dirt and dust which might adversely effect the permeability of the product. Furthermore, especially for the non-woven fabric types of outer bag material, dirt or dust particles may become entrapped in the fibrous material and render the article unacceptable to the end user.

While the outermost protective wrapper has been described as a separate, independent cover, it is also possible to laminate the outermost wrapper to the water-insoluble water-permeable outer bag using a peelable adhesive or by heat sealing along one or more edges.

In any case, it is a simple task for the consumer to remove the outermost protective wrapper before the detergent product is placed in the laundry machine.

As described in Clarke, et al. U.S. patent 4,348,293 it is also possible to provide suitable markings, e.g. printed advertisements, designs, instructions for use, etc., on either or both of the outermost waterproof protective wrapper or the outer water-permeable bag.

It is also within the scope of the invention to provide a coating on the fibers of the outer water-insoluble, water-permeable non-woven fabric bag of a fabric softening composition, such as a cationic quaternary ammonium salt, perhaps with a water-insoluble wax, such that the softening agent will not be activated (released) until the sachet is transferred, together with the washed textile fabrics, to a clothes drier. Such through the wash fabric softening materials are, per se, known in the art.

Similarly, the non-woven fabric may be impregnated with perfume or fragrance to be transferred to the washed articles.

Also, the detergent products, in any of the 5 foregoing embodiments, may be formed in a conjoined manner, for example, in a strip, with severable joints, to facilitate dosing of different numbers of bags as appropriate for different washing conditions and laundry loads.

The liquid detergent composition of the detergent product will now be described.

The liquid phase of the non-aqueous liquid detergent composition of this invention applicable to each of the different aspects is comprised of 15 liquid nonionic synthetic organic detergent and optionally, but preferably alkylene glycol monoalkyl ether, as a viscosity control and antigelling agent. A portion of the liquid phase may be composed, however, of other organic solvents 20 which may enter the composition as solvent vehicles or as carriers for one or more of the solid particulate ingredients, such as in enzyme slurries, perfumes, and the like.

The nonionic synthetic organic detergents 25 employed in the practice of the invention may be any of a wide variety of such compounds, which are well known and, for example, are described at length in the text Surface Active Agents, vol. II, by Schwartz, perry and Berch, published in 1958 by 30 Interscience Publishers, and in McCutcheon's Detergents and Emulsifiers, 1969 Annual, the relevant disclosures of which are hereby incorporated by reference. Usually, the nonionic detergents are polylower alkoxylated lipophiles wherein the desired hydrophile-lipophile balance is obtained from addition of a hydrophilic polylower alkoxy group to a lipophilic moiety. A preferred class of the nonionic detergent employed is the polylower alkoxylated higher alkanol wherein the alkanol is of 10 to 22 carbon atoms and wherein the number of mols of lower alkylene oxide (of 2 or 3 carbon atoms) is from 3 to 20. Of such materials it is preferred to employ those wherein the higher alkanol is a higher fatty alcohol of 10 to 11 or 12 to 15 carbon atoms and which contain from 5 to 18, preferably 6 to 14 lower alkoxy groups per mol. The lower alkoxy is often just ethoxy but. in some instances it may be preferably mixed with propoxy. Exemplary of such ethoxylated alcohols are those wherein the alkanol is of 12 to 15 carbon atoms and which contain about 7 ethylene oxide groups per mol, e.g., Neodol 25-7 and Neodol 23-6.5» which products are made by Shell chemical Company, Inc. The former is a condensation product of a mixture of higher fatty alcohols averaging about 12 to 15 carbon atoms, with about 7 mols of ethylene oxide, and the latter is a corresponding mixture wherein the carbon atom content of the higher fatty alcohol is 12 to 13 and the number of ethylene oxide groups present averages about 6.5. The higher alcohols are primary alkanols. Other examples of such detergents include Tergitol 15-S-7 and Tergitol ISS-9, both of which are linear secondary alcohol ethoxylates made by Union Carbide Corp. The former is mixed ethoxylation product of 11 to 15 carbon atoms linear secondary alkanol with seven mols of ethylene oxide and the latter is a similar product but with nine mols of ethylene oxide being reacted.

Also useful in the present compositions as a component of the nonionic detergent are higher molecular weight nonionics, such as Neodol 45-11, which are similar ethylene oxide condensation products of higher fatty alcohols with the higher fatty alcohol being of 14 to 15 carbon atoms and the number of ethylene oxide groups per mol being about 11. Such products are also made by Shell Chemical Company.

Another group of liquid nonionics, also available from Shell Chemical Company, Inc. under the Dobanol trademark include, for example, Dobanol 91-5, an ethoxylated Cg־C_n fatty alcohol with an average of 5 moles ethylene oxide; and Dobanol 25-7 an ethoxylated C!2^-c15 fatty alcohol with an average of 7 moles ethylene oxide; etc.

Other highly useful nonionics are represented by the commercially well-known class of nonionics which are the reaction product of a higher linear alcohol and a mixture of ethylene and propylene oxides, containing a mixed chain or blocks of ethylene oxide and propylene oxide, terminated by a hydroxyl group. Examples include the nonionics sold under the Plurafac trademark of BASF, such as a C13-C15 fatty alcohol condensed with 7 moles propylene oxide and 4 moles ethylene oxide, a ^c13”^c15 fatty alcohol condensed with 5 moles propylene oxide and 10 moles ethylene oxide, a ^c13־^c15 fatty alcohol condensed with 6 moles ethylene oxide and 3 moles propylene oxide, etc.

Generally, the mixed ethylene oxide-propylene oxide fatty alcohol condensation products represented by the general formula RO(C3H₆O)_p(C₂H4O)_qH, wherein R is a straight or branched, primary or secondary aliphatic hydrocarbon, preferably alkyl or alkenyl, especially preferably alkyl, of from 6 10 to 20, preferably 10 to 18, especially preferably to 18 carbon atoms, p is a number of from 2 to 8, preferably 3 to 6, and q is a number of from 2 to 12, preferably 4 to 10, can be advantageously used where low foaming characteristics are desired.

In addition, these surfactants have the advantage of low gelling temperatures. Mixtures of two or more of the mixed ethylene oxide-propylene oxide fatty alcohol condensation product can be used as can mixtures of the mixed ethylene oxide-propylene oxide condensation products with any of the above alkoxylated nonionics, or mixtures of the ethoxylated nonionics can also be used.

In view of their low gelling temperatures and low pour points, another preferred class of nonionic surfactants includes the C!2“^13 secondary fatty alcohols with relatively narrow range of contents of ethylene oxide within the range of from about 7 to 9 moles, especially about 8 moles ethylene oxide per molecule and the C9 to Cj!, especially Cjq fatty alcohols ethoxylated with about 6 moles ethylene oxide.

The compositions of this invention preferably include an organic alkylene glycol alkyl ether solvent which functions as a viscosity control and gel-inhibiting agent for the liquid nonionic surface active agent. Alkylene glycol alkyl ethers, such as the compounds sold under the trademarks, Carbopol and Carbitol which have relatively short hydrocarbon chain lengths (C2־Cg) and a low content of alkylene oxide (about 2 to 6 10 ethylene oxide and/or propylene oxide units per molecule) are especially useful viscosity control and antigelling solvents in the compositions of this invention. Suitable glycol ethers can be represented by the following general formula

R²

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R¹O(CH₂CHO)_nH where R¹ is a C^-Cg, preferably C1-C5, alkyl group, r2 is hydrogen or methyl and n is a number 20 of from about 1 to 6, preferably 1 to 4, on average.

The glycol ethers may also be considered as condensation products of Cj-Cg alcohols with ethylene oxide or propylene oxide at molar ratios 25 of alcohol to alkoxide of from 1:1 to 6:1.

Specific examples of suitable solvents include ethylene glycol monoethyl ether (C₂H5-O-CH₂CH2OH), diethylene glycol monobutyl ether (C4H9-O(CH2CH₂O)2H), tetraethylene glycol monooctyl ether 30 (CgH!7-O-(CH2CH2O)4H), tripropylene glycol methyl ether (CH3-O-(CH₂CH(CH3)O)3H), etc. Diethylene glycol monobutyl ether and tripropylene glycol monomethyl ether are preferred and tripropylene glycol methyl ether is especially preferred.

The amount of the nonionic surfactant is generally within the range of from about 20 to about 70%, such as about 30 to 60%, for example, 35% or 40% by weight of the composition. The amount of alkylene glycol ether is usually up to 20%, preferably up to 15%, for example, 0.5 to 15%, preferably 5.0 to 12.5%, such as 8%, 10% or 12%. The weight ratio of nonionic surfactant to alkylene glycol ether viscosity control and antigelling agent is in the range of from about 100:1 to 1:1, preferably from about 50:1 to about 2:1, such as 10:1, 8:1, 6:1, 4:1 or 3:1.

The invention detergent compositions also include, as an essential ingredient, at least one finely divided fabric-treating solid particulate material. Typical fabric-treating solid particles include detergent builder salts (which may be inorganic or organic in nature), bleach, bleach activator, antiredeposition and soil-suspending agents, enzymes, optical brighteners, pigments, thickening agents, and the like, and generally mixtures of two or more different classes of suspended solid particles will be present. Particularly preferred fabric-treating particles are the water-soluble and/or water-dispersible detergent builder salts of hydroxy polycarboxylic acid having from 4 to 8 carbon atoms. These builder salts may have two or three carboxylic acid groups and from 1 to 4 hydroxy groups per molecule. Preferably there are from 4 to 6 carbon atoms inclusive of the carboxyl carbon atoms per molecule. Examples of suitable acids include malic acid, HO2CCH2CH(OH)CO2Hj tartaric acid, HO2CCH(OH)CH(OH)CO2H; citric acid, HO2CCH2C(OH)(CO2H)CH2CO2Hj isocitric acid, HO2CCH2CH(CO2H)CH(OH)CO2H; tricarballylic acid (l,2-dihydroxy-l,2,3-propylenetricarboxylic acid), HO2CCH2C(OH)(CO2H)CH(OH)CO2H; trihydroxyglutaric acid, HO₂CCH(OH)CH(OH)CH(OH)CO2H; mucic acid, HO2CCH(OH)CH(OH)CH(OH)CH(OH)CH2H. Citric acid and tartaric acid are preferred.

As the cation of the salts of these acids the alkali metals, such as sodium and potassium, are preferred, particularly sodium. Furthermore, the salts may take the form of the mono-, di- or trisalt, such as monosodium, disodium or trisodium citrate, preferably the latter. However, where monosodium or disodium citrate is used it is preferred to add a supplemental alkaline builder salt, such as sodium silicate, e.g. disodium silicate, to adjust the pH to about the same level as obtained when using the trisodium citrate. Similarly, when using monosodium tartrate additional alkaline compounds can be added to increase the pH level to the desired alkaline range. Furthermore, the salts can be used in their anhydrous or hydrated form, e.g. sodium citrate, dihydrate.

The alkali metal mono- or poly-hydroxy- di- or tri-carboxylic acid salts have the advantage of their high calcium and magnesium binding capacity which enables them to inhibit formation of insoluble calcium and magnesium salts, namely the builders of this invention are superior antiencrustation agents.

In order to effectively function as antiencrustation agents, the hydroxy polycarboxylic acid builder salts are present in the composition in amounts of at least about 10%, preferably at least about 20%, and up to about 60%, preferably up to about 50%, for example, in the range of from about

15 or 20% to about 50 to 66%, especially preferably in the range of from about 25 to 45%, based on the total composition and further preferably constitute at least 50% by weight, preferably at least 75% by weight, of the total suspended solid particles present in the composition.

In addition to, or in place of, the hydroxy polycarboxylic acid salts, other conventional, preferably non-polyphosphate type, inorganic and/or organic builder salts can also be included in the composition. Typical suitable builders include, for example, those disclosed in the aforementioned U.S. Patents 4,316,812} 4,264,466; 3,630,929; 4,661,280 and many others. Water-soluble inorganic alkaline builder salts which can be used include alkali metal carbonates, borates, bicarbonates and silicates. (Ammonium or substituted ammonium salts can also be used.) Specific examples of such salts are sodium carbonate, sodium tetraborate, sodium bicarbonate, sodium sesquicarbonate, and potassium bicarbonate.

Although it is preferred that the detergent composition be free of phosphate or polyphosphate builders, in some cases small amounts of the conventional polyphosphate builder salts can be added where the local laws permit such use. Specific example of such builder salts include sodium or potassium tripolyphosphate, sodium potassium pyrophosphate, sodium hexametaphosphate, sodium mono- and diorthophosphate. Sodium tripolyphosphate (TPP), usually in amounts up to about 30% to 40%, preferably up to about 20%, such as from 5 to 15%, is especially preferred where phosphate containing ingredients are not prohibited due to environmental concerns. However, more preferably, the amount of phosphate or polyphosphate builder should not exceed 10%, for example, 0 to 6%, preferably 0 to 3%. No phosphate compositions are especially preferred.

Another class of inorganic builders which can be used are the water-insoluble aluminosilicates, both of the crystalline and amorphous type, e.g. crystalline zeolites.

Examples of organic alkaline sequestrant builder salts which can be used alone with the detergent or in admixture with other organic and inorganic builders are alkali metal, ammonium or substituted ammonium, aminopolycarboxylates, e.g. sodium and potassium ethylene diaminetretraacetate (EDTA), sodium and potassium nitrilotriacetates (NTA) and triethanolammonium N-(2-hydroxyethyl)nitrilodiacetates. Mixed salts of these polycarboxylates are also suitable.

Suitable additional builders of the organic type include carboxymethylsuccinates, tartronates and glycollates and the polyacetal carboxylates.

The total proportion of the suspended detergent builder, including the preferred hydroxy polycarboxylic acid salt or any of the other inorganic and/or organic builder salts, based on 5 the total composition, is usually in the range of from about 10 to 55 weight percent, such as about 20 to 50 weight percent, for example about 25 to 40% by weight of the composition. Above about 55% it becomes extremely difficult, even at high 10 solvent levels, to form easily flowable and pourable compositions.

It is often desirable to supplement the builder salt with an auxiliary builder such as a polymeric carboxylic acid having high calcium/15 magnesium binding capacity to further inhibit incrustation which could otherwise be caused by formation of insoluble calcium or magnesium salts. Such auxiliary builders are well known, and include for example, polyacrylic builders, such as Sokolan 20 CP5 which is a copolymer of about equal moles of methacrylic acid and maleic anhydride, completely neutralized to form the sodium salt thereof. The amount of the auxiliary builder is generally up to about 6 weight percent, preferably 1/4 to 4%, such 25 as 1%, 2% or 3%, based on the total weight of the composition.

Other fabric-treating solid particulate additives or adjuvants which may be present in the detergent product, usually in minor amounts, to 30 give it additional desired properties, either of functional or aesthetic nature, include soil suspending or antiredeposition agents, e.g.

polyvinyl alcohol, fatty amides, sodium carboxymethyl cellulose, hydroxy-propyl methyl cellulose, etc., usually in amounts of up to 10 weight percent for example 0.1 to 10%, preferably 1 to 5%; optical brighteners, e.g. cotton, polyamide and polyester brighteners, for example, stilbene, triazole and benzidine sulfone compositions, most preferred are stilbene brightener up to about 2 weight percent, preferably up to 1 weight percent, such as 0.1 to 0.8 weight percent, can be used.

Bluing agents such as ultramarine blue; enzymes, preferably proteolytic enzymes, such as subtilisin, bromelin, papain, trypain and pepsin, as well as amylase type enzymes, lipase type enzymes, and especially preferably mixtures of two or three different classes thereof; bactericides, e.g. tetrachlorosalicylanilide, hexachlorophene; fungicides; dyes; pigments (water-dispensable); preservatives; ultraviolet absorbers; antiyellowing agents, such as sodium carboxymethyl cellulose, pH modifiers and pH buffers; color safe bleaches, perfume, and antifoam agents or suds-suppressor, e.g. silicone compounds can also be used.

The bleaching agents are classified broadly for convenience, as chlorine bleaches and oxygen bleaches. Oxygen bleaches are preferred and are represented by percompounds which liberate hydrogen peroxide in solution. Preferred examples include sodium and potassium perborates, percarbonates, and perphosphates, and potassium monopersulfate. The perborates, particularly sodium perborate monohydrate, are especially preferred.

The peroxygen compound is preferably used in admixture with an activator therefor. Suitable activators which can lower the effective operating temperature of the peroxide bleaching agent are disclosed, for example, in U.S. Patent 4,264,466 or in column 1 of U.S. Patent 4,430,244, the relevant disclosures of which are incorporated herein by reference. Polyacylated compounds are preferred activators; among these, compounds such as tetraacetyl ethylene diamine (TAED) and pentaacetyl glucose are particularly preferred.

Other useful activators include, for example, acetylsalicylic acid derivatives, ethylidene benzoate acetate and its salts, ethylidene carboxylate acetate and its salts, alkyl and alkenyl succinic anhydride, tetraacetylglycouril (TAGU), and the derivatives of these.

It is preferred to include a sequestering agent of high complexing power to inhibit any undesired reaction between peroxyacid and hydrogen peroxide in the wash solution in the presence of metal ions. Preferred sequestering agents are able to form a complex with Cu2+ ions, such that the stability constant (pK) of the complexation is equal to or greater than 6, at 25°C, in water, of an ionic strength of 0.1 mole/liter. Suitable sequestering agents include, for example, in addition to those mentioned above, compounds, such as, for example, diethylene triamine pentaacetic acid (DETPA); diethylene triamine pentamethylene phosphoric acid (DTPMP); and ethylene diamine tetramethylene phosphoric acid (EDITEMPA).

According to the first aspect of this invention the physical stability of the suspension of the detergent builder compound or compounds or any other suspended additive, such as bleaching agent, etc., in the liquid vehicle is drastically improved by the presence of a stabilizing agent which, according to this invention, is an elastic network forming organophilic modified clay.

The organophilic modified clay can be based on any swelling clay modified to exhibit high gelling efficiency in the organic liquid vehicle. As examples of such swelling clay materials which can be used (after appropriate modification as described below) mention can be made of the smectite clays especially the bentonite, e.g. sodium and lithium bentonites; montmorillonites, e.g. sodium and calcium montmorillonites; saponites, e.g. sodium and calcium montmorilIonites; saponites, e.g. sodium saponites; and hectorites, e.g. sodium hectorites. Other representative clays include beidellite and stevensite.

The aforementioned smectite-type clays are three-layer clays characterized by the ability of the layered structure to increase its volume several-fold by swelling or expanding when in the presence of water to form a thixotropic gelatinous substance. There are two main classes of smectitetype clays: in the first class, aluminum oxide is present in the silicate crystal lattice; in the second class, magnesium oxide is present in the silicate crystal lattice. Atom substitution by iron, magnesium, sodium, potassium, calcium and the like can occur within the crystal lattice of the smectite clays. It is customary to distinguish between clays on the basis of their predominant cation. For example, a sodium clay is one in which the cation is predominantly sodium. Aluminum silicates wherein sodium is the predominant cation are preferred, such as, for example, bentonite clays. Among the bentonite clays, those from

Wyoming (generally referred to as western or Wyoming bentonite) are especially preferred.

Preferred swelling bentonite are sold under the trademark Mineral Colloid, as industrial bentonite, by Benton Clay Company, an affiliate of 15 Georgia Kaolin Co. These materials which are same as those formerly sold under the trademark THIXOJEL, are selectively mined and beneficiated bentonite, and those considered to be most useful are available as Mineral Colloid No.'s 101, etc. 20 corresponding to THIXO-JELs No's 1, 2, 3 and 4.

Such materials have pH's (6% concentration in water) in the range of 8 to 9.4, maximum free moisture contents of about 8% and specific gravities of about 2.6, and for the pulverized grade at least about 85% 25 (and preferably 100%) passes through a 200 mesh U.S.

Sieve Series sieve. More preferably, the bentonite is one wherein essentially all the particles (i.e., at lest 90% thereof, preferably over 95%) pass through a No. 325 sieve and most preferably all the 30 particles pass through such a sieve. The swelling capacity of the bentonite in water is usually in the range of 2 to 15 ml/gram, and its viscosity, at a 6% concentration in water, is usually from about 8 to 30 centipoise.

Instead of utilizing the THIXO-JEL or Mineral Colloid bentonite one may employ products, such as that sold by American Colloid Company, industrial Division, as General purpose Gentonite Powder, 325 mesh, which has a minimum of 95% thereof finer than 325 mesh or 44 microns in diameter (wet particle size) and a minimum of 96% finer than 200 mesh or 74 microns diameter (dry particle size). Such a hydrous aluminum silicate is comprised principally of montmorillonite (90% minimum), with smaller proportions of feldspar, biotite and selenite. A typical analysis on an anhydrous basis, is 63.0% silica, 21.5% alumina, 3.3% of ferric iron (as Εβ2θ3)» 0.4% of ferrous iron (as FeO), 2.7% of magnesium (as Mg)), 2.6% of sodium and potassium (as Na20). 0.7% of calcium (as CaO), 5.6% of crystal water (as H20) and 0.7% of trace elements.

Although the western bentonite are preferred it is also possible to utilize other bentonite, such as those which may be made by treating Italian or similar bentonite containing relatively small proportions of exchangeable monovalent metals (sodium and potassium) with alkaline materials, such as sodium carbonate, to increase the cation exchange capacities of such products. It is considered that the Na20 content of the bentonite should e at least about 0.5%, preferably at least 1% and more preferably at least 2% so that the clay will be satisfactory swelling. Preferred swelling bentonite of the types described above are sold under the trade names Laviosa and Winkelmann, e.g. Laviosa AGB and Winkelmann G-13. Other examples include Veegum F and Laponite SP, both sodium hectorites, Gelwhite L, a calcium montmorillonite, Gelwhite GP, a sodium montmorillonite, Barasym LIH 200, a lithium hectorite.

The smectite clay materials as described above are hydrophilic in nature, i.e. they display swelling characteristics in aqueous media. Conversely, they are organophobic in nature and do not swell in non-aqueous or predominantly nonaqueous systems.

According to this invention, the organophobic nature of the smectite clay materials is converted to an organophilic nature, for example, by exchanging the metal cation, e.g., Na, K, Li, Ca, etc. of the clay, with an organic cation, at least on the surface of the clay particles. This can be accomplished, for example, by admixing the clay, organic cation and water, together, preferably at a temperature within the range of 20° to 100°C, for a period of time sufficient for the organic cation to intercalate with the clay particles at least on the surface, followed by filtering, washing, drying and grinding. For further details reference can be made to any of the aforementioned U.S. Patents 2,531,427, 2,966,506, 4,105,578, 4,208,218, 4,287,086, 4,424,075 and 4,434,076, the disclosures of which are incorporated herein in their entireties by reference thereto.

The organic cationic material is preferably a quaternary ammonium compound, particularly one

τ. * ׳ϊ .e having surfactant properties, indicative of at least one long chain hydrocarbon group (e.g. from about 8 to about 22 carbon atoms), although surfactant properties or other fabric beneficial properties are not required, nor is it essential that the cationic modifier itself be useful as a suspension agent. However, any of the cationic surfactant compounds disclosed as useful auxiliary suspension aids in the U.S. Patent 4,264,466, at 10 columns 23-29, the disclosure of which is incorporated herein in its entirety, can be used for modifying the smectite clay material to render the latter organophilic. The organic cationic nitrogen compounds described in the U.S. Patent 2,531,427 to

Hauser, or those mentioned in any of the NL Industries patents 2,966,506; 4,105,578, and so on, the disclosures of which are incorporated herein by reference, can also be favorably used.

The preferred modifiers are the quaternary 20 ammonium compounds of formula

[r₁R₂R3R4N]+ Xwherein Rj, r₂, R3 and R4, are each, independently, hydrogen, or a hydrophobic organic alkyl, aryl, aralkyl, alkaryl or alkenyl radical 25 containing from 1 to 30 carbon atoms, preferably 1 to 22 carbon atoms, at least two R groups preferably having from 1 to 6 carbon atoms and at \ least one R group, preferably at most two R groups, having from 8 to 22 carbon atoms; and X is an anion, 30 which may be inorganic, such as halide, e.g.

chloride or bromide, sulfate, phosphate, hydroxide, or nitrate, or organic, such as methylsulfate,

ן

ד3 ethylsulfate, or fatty acid, e.g. acetate, propionate, laureate, myristate, palmitate, oleate or stearate.

Examples of preferred organophilic modifiers are the mono-and di-long chain (e.g. Cg to C!g, especially c!q to C!g) alkyl quaternary compounds. Representative examples of the mono-long chain quaternary ammonium surfactants include stearyl trimethyl ammonium chloride, tallow trimethyl ammonium chloride, benzyl stearyl dimethyl ammonium chloride, benzyl hydrogenated tallow dimethyl ammonium chloride, benzyl cetyl dimethyl ammonium chloride and the corresponding bromides, iodides, sulfates, methosulfates, acetates, and other anions previously mentioned. Typical representative examples of the di-long chain quaternary ammonium compounds include dimethyl distearyl ammonium chloride, dimethyl dicetyl ammonium chloride, dimethyl stearyl cetyl ammonium chloride, dimethyl ditallow ammonium chloride, dimethyl myristyl cetyl ammonium chloride, and the corresponding bromides, iodides, sulfates, methosulfates, acetates and other anions previously mentioned. Other representative compounds include octadecyl ammonium chloride, hexadecyl ammonium acetate, and so on. In addition to the quaternary ammonium (QA) compounds, other quaternizable nitrogen containing organic cations can also be used to form organophilic clay particles. For instance mention can be made of imidazolinium compounds such as, for example, 1-(2-hydroxyethyl)-2-dodecyl-l-benzyl-2 imidazolinium chloride, and heterocyclic nitrogen ring containing compounds, such as long chain hydrocarbon substituted pyrrolidones, pyridenes, morpholines, and the like, such as N,N-octadecyl~ morpholinium chloride.

The amount of organic cation substitution need only be that amount sufficient to impart to the clay the requisite organophilic property to provide the enhanced stabilizing characteristic desired. Generally, depending on the nature of the organic substituent this amount can range from about 10 to 100%, preferably 20 to 100%, such as 30%, 40%, 50% or 60%, of the available base exchange capacity of the clay material. Usually, and preferably, at least sufficient of the organic compound is used to cover or coat the surface of the clay particles.

Suitable organophilic clays which can be used in this invention are commercially available, for example, the products sold under the Bentone trademark of NL Industries, New York, New York, such as Bentone 27, which is a hectorite clay (magnesium montmorillonite) modified with benzyl dimethyl hydrogenated tallow ammonium chloride, and Bentone 38, which is a hectorite clay, modified with dimethyl dioctadecyl ammonium chloride. Other sources of organophilic clays include, for example, Sud-Chemie, Munich Germany; Laviosa, Livorno, Italy; Laporte, France; and Perchem, United Kingdom.

The organophilic clays are used in only minor amount, generally less than 1.0% by weight, preferably less than 0.7% by weight, based on the total composition. Usually, amounts of at least about 0.1 weight percent, preferably 0.2 weight ³⁹percent, such as 0.25%, 0.3%, 0.35% or 0.4%, will enable production of stable, thixotropic non-aqueous liquid suspensions of finely divided detergent builder or other water-soluble or dispersible fabric treating agent.

The organophilic modified clay can be incorporated into the non-aqueous liquid dispersion of the suspended particulate ingredients either directly as a powder or after first being predispersed in a portion of the liquid vehicle of the suspension, e.g., the liquid nonionic surfactant, the latter method being preferred. Furthermore, whether added to the suspension directly as a powder or pre-gelled in a portion of the liquid vehicle, the organophilic clay may be added to the suspension before or after the suspension is ground to the required average particle size of no more than 15 microns, preferably no more than 10, especially from 1 to 10 microns, most preferably from 4 to 8 microns.

in a preferred embodiment the organophilic clay is first predispersed either in part of the liquid nonionic surfactant forming the principal liquid vehicle or in a different nonionic surfactant or in a solvent or diluent as previously described, or in any suitable mixture of surfactant(s), and/or solvent(s), and/or diluent(s). The predispersed clay suspension, if necessary, can be subjected to grinding in a high shear grinder, to form an organophilic clay pregel. Separately, the remaining solid particulate matter is suspended in the liquid nonionic surfactant and ί

optional diluent/solvent, and is also subjected to grinding. The clay pregel and the particulate matter suspension can be ground to the final desired average particle size before they are mixed with each other, or the pregel and suspension can be mixed and then subjected to further grinding, in the latter case, the suspended particulate matter can further contribute to the attrition of the organophilic clay particles.

It is also within the scope of this invention to include other suspension stabilizers, rheological additives, and antigelling agents.

Other suspension stabilizers can also be used.

For example, the aluminum salts of higher fatty 15 acids, especially aluminum stearate, as disclosed in

U.S. Patent 4,661,280, the disclosure of which is incorporated herein by reference, can be added to the composition, for example, in amount of 0 to 3% by weight, preferably 0 to 1% by weight, such as 20 0.05 to 0.8% by weight.

Another potentially useful stabilizer is an acidic organic phosphorus compound having an acidic -POH group. The acidic organic phosphorus compound, may be, for instance, a partial ester of 25 phosphoric acid and an alcohol, such as an alkanol having a lipophilic character, having, for instance, more than 5 carbon atoms, e.g. 8 to 20 carbon atoms. A specific example is a partial ester of phosphoric acid and a C!6 to Cjg alkanol.

Empiphos 5632 from Marchon is made up of about 35% monoester and 65% diester. When used, amounts of

-ί the phosphoric acid compound up to about 3%, preferably up to 1%, are sufficient.

A nonionic surfactant which has been modified to convert a free hydroxyl group to a moiety having 5 a free carboxyl group, such as a partial ester of a nonionic surfactant and a polycarboxylic acid, can be incorporated into the composition to further improve rheological properties. For instance, amounts of the acid-terminated nonionic surfactant 10 of up to 1 per part of the nonionic surfactant are sufficient.

Preferred detergent compositions of this invention are formulated using the below named ingredients in the preferred (broad), more 15 preferred (intermediate) and most preferred (narrow) proportions:

Weight

Broad Intermediate Narrow

<td> 20</td><td> Nonionic surfactant detergent</td><td> 20-50</td><td> 28-50</td><td> 30-46</td>

<td></td><td> Alkali metal hydroxy polycarboxylic acid builder salt 1/</td><td> 20-42</td><td> 22-40</td><td> 25-37</td>

<td> 25</td><td> Antiencrustation agent, e.g. copolymer of methacrylic acid and maleic anhydride, alkali metal salt</td><td> 0-5</td><td> 1-3</td><td> Γ. 5-2.5</td>

<td></td><td> Other builder salt(s) 2J</td><td> 0-30</td><td> 0-20</td><td> 0-10</td>

<td> 30</td><td> Alkylene glycol alkyl ether, viscosity reducing solvent/antigel agent</td><td> 0-20</td><td> 6-15</td><td> 8-12.5</td>

<td> Alkanol phosphoric acid ester</td><td> 0-1</td><td> 0-0.5</td><td> 0-0.2</td>

<td> Acid terminated nonionic surfactant</td><td> 0-10</td><td> 0-8</td><td> 0-4</td>

<td> Bleaching agent</td><td> 0-20</td><td> 8-15</td><td> 9-13.5</td>

<td> Bleach activator</td><td> 0-8</td><td> 3-6</td><td> 3.5-5.5</td>

<td> Alkali metal silicate corrosion inhibitors</td><td> 0-20</td><td> 0-15</td><td> 0-10</td>

<td> Sequestering agent</td><td> 0-4</td><td> 0.2-1.0</td><td> 0.4-0.6</td>

<td> Antiredeposition agent</td><td> 0-5</td><td> 0.6-1.5</td><td> 0.8-1.25</td>

<td> Optical Brightener</td><td> 0-0.8</td><td> 0.2-0.6</td><td> 0.25-0.4</td>

<td> Enzymes</td><td> 0-2</td><td> 0.1-1.3</td><td> 0.4-0.7</td>

<td> Perfume</td><td> 0-1</td><td> 0.2-1.0</td><td> 0.4-0.6</td>

<td> Dye and/or Pigment</td><td> 0-1</td><td> 0.2-0.6</td><td> 0.3-0.5</td>

<td> Antifoam agents and suds suppressors</td><td> 0-15</td><td> 0-5</td><td> 0-3</td>

<td> Organophilic clay 3/ 0.</td><td> 05-1.0</td><td> 0.1-0.7</td><td> 0.2-0.5</td>

<td colspan="2"> 1/ Ranges given for third aspect</td><td colspan="2"> .; otherwise</td>

optional ingredient.

2/ Ranges given for third aspect; otherwise ~ amounts can be 10-50, 20-45 and 22-40 wt. % for broad, intermediate and narrow ranges, respectively.

3/ Ranges given for first aspect; otherwise optional ingredient.

In a preferred form of the invention, applicable to all aspects thereof, the mixture of liquid nonionic surfactant and solid ingredients is ׳s subjected to grinding, for example, by a sand mill or ball mill. Especially useful are the attrition types of mill, such as those sold by WienerAmsterdam or Netzsch-Germany, for example, in which the particle sizes of the solid ingredients are reduced to less than about 15 microns, e.g. to an average particle size of 2 to 10 microns or even lower (e.g. 1 micron). Preferably, less than about 10%, especially less than about 5% of all the suspended particles have particle sizes greater than 15 microns, preferably 10 microns. Since the hygroscopicity of the ground particles, especially when present, generally increases as particles size decreases it is often preferred that the average particle size be at least 3 microns, especially about 4 microns. Compositions whose dispersed particles are of such small size have improved stability against separation or settling on storage. Other types of grinding mills, such as toothmill, peg mill and the like, may also be used.

In the grinding operation, it is preferred that the proportion of solid ingredients be high enough (e.g. at least about 40%, such as about 50%) that the solid particles are in contact with each other and are not substantially shielded from one another by the nonionic surfactant liquid. Mills which employ grinding balls (ball mills) or similar mobile grinding elements have given very good results. Thus, one may use a laboratory batch attritor having 8 mm diameter steatite grinding balls. For larger scale work a continuously operating mill in which there are 1 mm or 1.5 mm diameter grinding balls working in a very small gap between a stator and a rotor operating at a relatively high speed (e.g. a CoBall mill) may be employed; when using such a mill, it is desirable to 5 pass the blend of nonionic surfactant and solids first through a mill which does not effect such fine grinding (e.g. a colloid mill) to reduce the particle size to less than 100 microns (e.g. to about 40 microns) prior to the step of grinding to 10 an average particle diameter below about 15 microns in the continuous ball mill.

Alternatively, the powdery solid particles may be finely ground to the desired size before blending with the liquid matrix, for instance, in a 15 jet-mill.

The compositions of this invention, according to the first aspect thereof, i.e. with the organophilic clay, are gel-like liquid suspensions, generally exhibiting non-Newtonian flow character20 istics, especially thixotropy, namely reduced viscosity under applied stress or shear, and behave, theologically, substantially according to the Casson equation. The compositions are characterized by a yield stress between about 2.5 25 and 45 pascals, more usually between 10 and 55 pascals, such as 15, 20 or 25 pascals. When shaken or subjected to stress, such as being squeezed through a narrow opening in a squeeze tube bottle, for example, the product is readily flowable.

The compositions of this invention may also be, and preferably are, especially in the embodiments of the second and third aspects, formulated as easily pourable liquid suspensions, having viscosities ranging from about 50 to 8,000 m

Pa-sec (50 to 8,000 centipoise), usually from about to 6,000 m Pa.sec, such as 160, 200 or 240 m

Pa.sec on the low end or 2,000, 2,500, 3,000, 4,000 or 5,000 m Pa-sec on the high end, such that the product is readily flowable even at temperatures as low as 5°C or below. In order to achieve the preferred viscosity range and easy pourability, the solids loading of the suspension, including builders, bleach, and the like, should generally, depending on such factors as particle size, liquid phase ingredients, types of suspended particles, and the like, be maintained at a total amount of less than about 55%, especially less than 50%, based on the weight of the composition. Thickening agents and stabilizers, such as the organophilic clays, used in the embodiments of the first aspect, aluminum stearate, and the like, should then be avoided or used at very low levels, for example, 0.01 to 0.2% of the organophilic clay, and 0.01 to 0.1% of aluminum stearate or other mono- or polyvalent metal salt of a C!2 ^{to c}22 aliphatic fatty acid.

The non-aqueous liquid detergent compositions of this invention may, in addition to the unitary packages described above, also be packaged in ordinary vessels, such as glass or plastic, rigid or flexible bottles, jars of other containers.

Since they are generally readily flowable at temperatures as low as 5°C they are easily pourable and can be dispensed directly from the container into the aqueous wash bath, such as in an automatic washing machine, in usual amounts, such as 1/4 to 1 1/2 cups, for example, 1/2 cup, per laundry load (of approximately 3 to 15 pounds, for example), for each load of laundry, usually in 8 to 18 gallons of water. The preferred compositions will also remain stable (no more than 1 or 2 mm liquid phase separation) when left to stand for periods of 3 months or longer.

It in also possible, especially where thickeners are added to the composition, to transfer (some shaking or shear force may be necessary or helpful) the thickened (e.g. thixotropic or gel-like) composition into a perforated dispenser (referred to as a doserette), such as a plastic (water-insoluble) ball, having an inner volume preferably just sufficient to hold up to 1 1/2 cups, or other appropriate amount corresponding to the maximum recommended dosage for a large load of laundry. For this purpose the ball is provided with a closable wide fill opening through which the composition can be poured and then closed, for example, a screw cap, friction cap or the like. The perforations will be sufficiently small, for example, 1/64-inch to 1/8-inch, preferably 1/64 to 1/16 inch, in diameter, to prevent the thickened composition from freely flowing out of the perforations in the doserette. However, the perforations are sufficiently large to allow the water of the aqueous wash bath to freely flow into the doserette and to sufficiently dilute the thickened suspension so as to allow the composition to be washed out of the doserette into the aqueous wash bath over the first several minutes of the wash cycle, for example in about 1 to 3 minutes. In this way, the consumer can readily fill the doserette to the appropriate level for the amount and type of laundry being washed and place the filled doserette (after sealing the fill opening) directly into the washing machine with the load of laundry. Preferably, the doserette is formed of sufficiently strong plastic, such as polystyrene, polyethylene, polypropylene, polyvinyl chloride, etc. to be able to withstand repeated usage.

In the preferred embodiment wherein the nonaqueous liquid detergent composition is provided in the form of a unitary package as described above, it may not be as critical to formulate the composition with ingredients which inhibit phase separation since there is less problem of using the proper proportion of ingredients, since the entire package will normally be added to the wash bath. Similarly, when single dose packages are provided to the consumer, pourability is not, per se, such an essential criteria, and the compositions may be more viscous, e.g. up to about 50,000 cps or more, or gel-like or thixotropic.

However, here too, readily pourable compositions, especially in the viscosity range of from about 1000 to 8000 cps, preferably 2000 to 6000 cps are preferred. Within the preferred viscosity raiige the package filling operation is often facilitated. In addition, with these still flowable and pourable compositions, the solution rate of the composition

8־ into the wash bath may often be higher, as compared to a similar but more viscous or thickened product which may have a greater tendency to settle to the bottom of the wash bath or remain as a coherent mass. In other words, the less viscous pourable compositions preferred herein and which have high dissolution rates in the wash bath can begin to exert their cleaning performance throughout the wash bath more rapidly and will not provide unnecessarily 10 and often undesireably high local concentrations of detergent or other functionally active ingredients. In this regard, the detergent products of this invention are considered to be advantageous over previously proposed unitary packages filled with highly viscous, gel-like or paste formulations.

It is understood that the foregoing detailed description is given merely by way of illustration and that variations may be made therein without departing from the spirit of the invention.

It should also be understood that as used in the specification and in the appended claims the term non-aqueous'* means absence of water, however, small amounts of water, for example up to about 5%, preferably up to about 2%, may be tolerated in the 25 compositions, and therefore, non-aqueous compositions can include such small amounts of water, whether added directly or as a carrier or solvent for one of the other ingredients in the composition, or crystallization water (e.g. sodium citrate dihydrate).

The invention will now be described by way of the following non-limiting examples in which all proportions and percentages are by weight, unless otherwise indicated. Also, atmospheric pressure is used unless otherwise indicated.

Example 1

A non-aqueous built liquid detergent composition according to the invention is prepared by mixing and finely grinding to about 4 microns the following ingredients in the following approximate amounts (ground base A) and thereafter adding to the resulting dispersion, with stirring, the components B;

Amount

Ground Base A Weight% (Based on A + B)

Nonionic Surfactant 1/ 32%

Diethylene glycol monobutyl ether 10.5%

Sodium tripolyphosphate (hydrated) 30%

Sokolan HC 9786 2/ 2%

Carboxymethyl cellulose 1%

Sodium perborate monohydrate 11%

Tetraacetylethylenediamine 4.5%

DEQUEST 2066 3/ 1%

Tinopal ATS-X^-(optical brightener) 0.3%

TiOo (Rutile) 0.4%

Bentone 27 4/ 0.45%

Post Addition B

Enzyme slurries 5/ 0.55%

Nonionic surfactant 1/ 3%

1/ Purchased from BASF, a mixed propylene oxide (4 moles) - ethylene oxide (7 moles) condensate of a fatty alcohol having from 13 to 15 carbon atoms

2/ Copolymer of methacrylic acid and maleic anhydride

3/ Diethylene triamine pentamethylene phosphoric ~ acid

4/ Hectorite clay, modified with dimethyl benzyl ~ hydrogenated tallow ammonium chloride, 35% cation exchanged, from NL Industries

5/ Mixture of Alcalase 2.5 L (0.25%), Savinase

8SL (0.2%), Termamyl 300 SL (0.1%) enzyme slurries (in nonionic surfactant) (products of

NOVO)

The composition, after standing for one day, had yield stress of 20 Pa and a plastic viscosity of 160 m pa.sec. The above composition and a comparison composition without the organophilic clay stabilizer are each filled into three 1 liter glass containers and allowed to stand for 3 months at 4°C, room temperature (approximately 22°C), and 35°C and the amount of free liquid on the top of each sample is measured. The results are shown in the following table.

PHYSICAL STABILITY AFTER 3 MONTHS

Liquid Separation (millimeters) _________Temperature___________ 4°C 22°C 35״C

Example (with 1 (1) 1 (1) 1 (1)

Bentone) Comparison (without Bentone) 9 (3) 14 (5) 18 (8)

In the above table, the numbers in parentheses represent the results when the above test is repeated except that the bottles are vigorously shaken by hand for about 15 seconds once every two weeks.

Thus, it can be seen that the addition of small amounts of organophilic clay substantially improve the physical stability of the non-aqueous suspensions. Although not wishing to be bound by any theory, it appears that the organophilic clay adds sufficient body to the composition, forming a structure analogous to an elastic network of particles, which can maintain the physical stability and configuration of the formulation even when it is subjected to sufficient shaking or shearing to result in breakage of the flocculated 5 network of the suspended builder and/or other fabric treating particles.

If the above example is repeated except that in place of Bentone 27, Bentone 38 (hectorite clay modified with dimethyldioctadecyl ammonium chloride) is used, similar results will be obtained. Similarly, replacing the nonionic surfactant with other mixed ethylene oxide/propylene oxide alcohol condensates, such as C13-C15 fatty alcohol condensed with 5 moles propylene oxide and

10 moles ethylene oxide, or C13-C15 fatty alcohol condensed with 7 moles propylene oxide and 4 moles ethylene oxide, or Dobanol 25-7 or Neodol 23-6.5, will provide similar results.

Example 2

A non-aqueous built liquid detergent composition according to the invention is prepared by mixing and finely grinding to about 4 microns the following ingredients in the following approximate amounts:

Weight %

Nonionic Surfactant 1/13.5

Nonionic surfactant 2/10.0

Nonionic surfactant 3/10.0

Acid terminated nonionic surfactant £/5.0

Trisodium citrate29.6

Copolymer of methacrylic acid and maleic4.0 anhydride, sodium salt

Diethylene glycol monobutylether10.0

Alkanol phosphoric acid ester0.3

Sodium perborate monohydrate9.0

Tetraacetylethylene diamine4.5

Diethylene triamine pentamethylene phosphoric 1.0 acid sodium salt

Carboxymethyl cellulose, Na salt/methyl1.0 cellulose (2:1 mixture)

Optical brightener0.5

Esperase SL8 (Protease enzyme)1.0

Perfume 0.5925

Dye 0.0075

100.000

1/ An equal mixture of C13-C15 fatty alcohol condensed with 7 moles of propylene oxide and 4 moles ethylene oxide and C13-C15 fatty alcohol condensed with 5 moles propylene oxide and 10 moles ethylene oxide.

2/ Secondary C!3 fatty alcohol ethoxylated with 7 moles ethylene oxide (narrow distribution).

3/ Secondary Cjj fatty alcohol ethoxylated with 9 moles ethylene oxide (narrow distribution).

£/ Half ester of Cq-Cn fatty alcohol ethoxylated with 5 moles ethylene oxide and succinic acid anhydride.

Example 3

The following non-aqueous liquid laundry detergent composition is prepared:

Weight %

C13-C15 fatty alcohol condensed with 737.9 moles ethylene oxide and 4 moles 10 propylene oxide

Tripropylene glycol methyl ether10.3

Sodium citrate-dihydrate30.5

Sodium perborate, monohydrate11.3

Tetraacetyl ethylene diamine4.6

Sodium carboxymethyl cellulose1.0

Ethylene diamine tetraacetic acid,0.51 sodium salt

Enzymes

Alcalase 2.5 SL0.26

Savinase 8.0 SL0.20

Termamyl 300 SL0.10

TiOj (Rutile)0.41

Optical Brightener (Tinopal ATS-X)0.31

Copolymer of methacrylic acid and maleic2.1 anhydride, sodium salt

Perfume0.51

100.00

The composition has a viscosity at 25°C of about 5000 cps.

Example 4

This example relates to a double wall sachet unitary package according to this invention. Two polyvinyl alcohol films measuring approximately 3.35 inches wide by 3.75 inches long are heat sealed to each other along both longitudinal edges and along a line spaced about 0.2 inches from the bottom edge. The polyvinyl alcohol films used were obtained from Nedi Co. of France, under the tradename NEDOL 210EF (about 85% hydrolyzed polyvinyl alcohol). The PVA pouch is then filled with about 100 grams of the composition described in Example 3 through the opening in the top portion of the pouch. Thereafter the top portion is also heat sealed along a line spaced about 0.2 inches from the top edge. The heat sealing is carried out at a sealing pressure of about 2.0 Kg/cm2 for about 1 second using sealing bars heated to a temperature in the range of about 35°C to 70°C, depending on the relative humidity. For instance, at a relative humidity of 40%, a sealing temperature of from about 55-60°C is satisfactory, while at 70% R. H. a temperature of from 43-49°C is recommended; and at 80% R. H. a temperature of from 38’c to 43°C is recommended.

The outer pouch is formed from a non-woven polyester containing about 40% of binder fiber, having a fabric density of 24 grams per square meter and available from Kendall Co. of Boston, Massachusetts. Two sheets of the non-woven fabric each measuring about 3.75 inches wide by about 4 inches long are placed on either side of the polyvinyl alcohol inner bag such that the side edges of the polyester fabric are equally spaced from the side edges of the inner bag while the bottom and top edges of the inner and outer bags are aligned. The polyester fabric sheets are then heat sealed along the four outer edges thereof to form the outer bag. Furthermore, the outer bag is heat sealed to the inner bag along lines approximately 0.1 inch from the top and bottom edges of the pouch.

When the sachet is placed in a conventional laundry automatic washing machine all of the liquid detergent will be dispensed during the first few minutes of the wash cycle. Clumps of undissolved residual polyvinyl alcohol remaining from the inner bag substantially remain within the sachet at the conclusion of the wash cycle - including the rinse and spin dry cycles.

Example 5

Example 4 is repeated except that the composition of Example 1 or Example 2 is filled in the PVA pouch. Similar results are obtained.

Example 6

Example 4 is repeated except that in place of the non-woven polyester fabric, the outer pouch is formed from spun-bonded polypropylene having a fabric density of about 20 gm/sq. meter. Results similar to Example 4 are obtained.

Example 7

In order to demonstrate the effect on encrustation of the substitution of sodium tripolyphosphate by an equivalent detergent builder amount of trisodium citrate, the detergent composition formulation of Example 2 containing 29.6% by weight of trisodium citrate was compared for a single wash cycle in an automatic laundry washing machine with the same composition in which the trisodium citrate is replaced with 29*61 by weight of sodium tripolyphosphate. Separate wash 5 cycles were carried out with the trisodium citrate and sodium tripolyphosphate detergent compositions at laundry wash water concentrations of each of the detergent compositions of 1, 2, 3.5, 5, 7 and 9 gm/liter.

After each detergent composition was used in a washing machine the amount of encrustation that resulted, i.e. the percent ash deposited, was measured. The percent ash deposited measurement is determined by calcination of washed swatches.

The results observed are reported in the graph illustrated in the Figure 1 drawing and show that at detergent composition concentrations of 1 to 5 g/1 of wash water the trisodium citrate is substantially better than sodium tripolyphosphate in preventing encrustation or ash deposit. At detergent composition concentrations of about 5 to 9 g/1 of wash water the behavior of trisodium citrate and sodium tripolyphosphate detergent builder salts are about the same in their antiencrustation properties.

Example 8

The effect of encrustation buildup in repeated laundry washing machine wash cycles was tested with the same compositions used in Example 7.

The repeated wash cycles were carried out at 5 g/1 wash water concentrations of each of the detergent compositions for twelve washing cycles. The encrustation buildup, i.e. percent ash buildup was measured in each washing machine after 3, 6, 9 and 12 washings.

The results of encrustation buildup obtained is reported in the graph illustrated in the Figure 2 drawing. As far as the encrustation buildup is concerned, no buildup was observed with the sodium tripolyphosphate detergent builder salt.

It is understood that the foregoing detailed description is given merely by way of illustration and that variations may be made therein without departing from the spirit of the invention.