FIELD OF THE INVENTION

This invention relates to liquid cleaning products for fabric laundering. Such products are nonaqueous in nature and are in the form of stable dispersions of particulate material that includes peroxygen bleaching agents and specific types of coated peroxygen bleach activators

BACKGROUND OF THE INVENTION

Liquid cleaning, e.g. bleaching products are often considered to be more convenient to use than are dry powdered or particulate cleaning products. Liquid cleaners have therefore found substantial favor with consumers. Such liquid detergent products are readily measurable, speedily dissolved in the wash water, capable of being easily applied in concentrated solutions or dispersions to soiled areas on garments to be laundered and are non-dusting. They also usually occupy less storage space than granular products. Additionally, liquid cleaning products may have incorporated in their formulations materials which could not withstand drying operations without deterioration, which operations are often employed in the manufacture of particulate or granular detergent or bleach products.

Although liquid cleaners have a number of advantages over granular cleaning products, they also inherently possess several disadvantages. In particular, detergent or bleach composition components which may be compatible with each other in granular products may tend to interact or react with each other in a liquid, and especially in an aqueous liquid, environment. Thus such components as enzymes, surfactants, perfumes, brighteners, solvents and especially bleaches and bleach activators can be especially difficult to incorporate into liquid cleaning products that have an acceptable degree of chemical stability.

One approach for enhancing the chemical compatibility of detergent or bleach composition components in liquid cleaning products has been to formulate nonaqueous (or anhydrous) liquid detergent compositions. In such nonaqueous products, at least some of the normally solid cleaning composition components tend

to remain insoluble in the liquid product and hence are less reactive with each other than if they had been dissolved in the liquid matrix. Nonaqueous liquid detergent compositions, including those which contain reactive materials such as peroxygen bleaching agents, have been disclosed for example, in Hepworth et al., U.S. Patent 4,615,820, Issued October 17, 1986; Schultz et al., U.S. Patent 4,929,380, Issued May 29, 1990; Schultz et al., U.S. Patent 5,008,031, Issued April 16, 1991; Elder et al., EP-A-030,096, Published June 10, 1981 ; Hall et al., WO 92/09678, Published June 1 1, 1992 and Sanderson et al., EP-A-565,017, Published October 13, 1993.

Even in non-aqueous liquid products, a problem of chemical stability can arise when peroxygen bleaching agents and peroxygen bleach activators are included. Bleach activators, in particular, tend to react with nucleophilic components such as ethoxylated alcohol nonionic surfactants that are frequently used to form the liquid phase of such non-aqueous cleaning products. Such nucleophilic materials can attack conventional bleach activators, e.g., cross-esterirying with them, and can thereby deactivate such activators before they can be delivered to aqueous washing or bleaching solution.

One approach which has historically been used to permit formulation of chemically incompatible components into a single detergent or bleach composition has been to coat or encapsulate one or more of these components. amel et al; U.S. Patent 5,230,822; Issued July 27, 1993, for example, discloses the encoding or encapsulation of certain types of peroxygen bleaching agents and bleach activators in various types of bleach-containing products. Notwithstanding the general availability of component coating as a means for enhancing cleaning composition chemical stability, there remains a continuing need to identify specific combinations of bleaching agents, bleach activators, coating technology and cleaning composition matrices that can be used to realize bleach-containing cleaning products of especially desirable cleaning performance and chemical/physical stability.

SUMMARY OF THE INVENTION

The present invention relates to a certain type of coated particulate material which contains a peroxygen bleach activator and which is especially suitable for incorporation into certain types of peroxygen bleach-containing non-aqueous liquid cleaning compositions. Such coated particulate material comprises a plurality of individual particles ranging in average particle size from about 20 to 800 microns. Each particle contains from about 20% to 95% by weight of a solid core material and from about 5% to 80% by weight of a coating material which substantially

completely encapsulates the solid core material. The solid core material comprises a normally solid bleach activator capable of reacting with a peroxygen compound in aqueous solution to thereby form in situ a peroxyacid corresponding to the bleach activator; and preferably also comprises an inert carrier material for the bleach activator. The coating material which surrounds this solid core material is selected from those citrates, sulfates, carbonates, silicates, halides and chromates, which are soluble in water, but insoluble in non-aqueous liquids.

The present invention also relates to certain types of non-aqueous liquid bleach-containing cleaning compositions which are in the form of a suspension of solid, substantially insoluble particulate material dispersed throughout a non¬ aqueous liquid phase. Such compositions comprise:

A) from about 30% to 80% by weight of one or more non-aqueous organic liquids;

B) from about 2% to 15% by weight of particles of peroxygen bleaching agent dispersed throughout these non-aqueous organic liquids; and

C) from about 2% to 20% by weight of coated particles of peroxyen bleach activator material also dispersed through the non-aqueous organic liquids.

The particles of the peroxygen bleaching agent range in average particle size from about 10 to 800 microns. The coated bleach activator particles range in average size from about 20 to 800 microns. The coated activator particles are coated with a solid salt material that is soluble in water but insoluble in the non-aqueous organic liquid component ofthe compositions herein.

DETAILED DESCRIPTION OF THE INVENTION

The coated bleach activator particles of this invention, as well as non-aqueous liquid, fabric cleaning compositions which contain these coated bleach activator particles, are described in greater detail as follows. All concentrations and ratios are on a weight basis unless otherwise specified.

COATED BLEACH ACTIVATOR PARTICLES

The bleach activator particles of this invention comprise bleach activator material, optionally coextruded, agglomerated or otherwise combined with an inert

carrier material, which has been coated with a certain type of coating material having specific solubility characteristics in non-aqueous fabric cleaning products. These particles, compositions as well as the particle and composition preparation processes, are described hereinafter.

(A) Activator Material

The bleach activators employed in this invention are those normally solid materials which are capable of reacting with a peroxygen compound in aqueous solution to form in situ a peroxyacid corresponding to the bleach activator structure. Such reacting and in situ peracid generation will generally occur during use of activator-containing products to form fabric bleaching and/or laundering solutions.

Various non-limiting examples of activators are disclosed in U.S. Patent 4,915,854, Issued April 10, 1990 to Mao et al.; and U.S. Patent 4,412,934 Issued November 1, 1983 to Chung et al. The nonanoyloxybenzene sulfonate (NOBS) and tetraacetyl ethylene diamine (TAED) activators are typical. Mixtures of these activators can also be used. Burns et al, U.S. Patent 4,634,551 ; Issued January 6, 1987 also discloses typical bleach activators useful in this invention. All of these patents are incorporated herein by reference.

Other useful amido-derived bleach activators are those ofthe formulae:

R ¹ N(R ⁵ )C(O)R ² C(O)L or RlC(O)N(R ⁵ )R ² C(O)L

wherein R s an alkyl group containing from about 6 to about 12 carbon atoms, R ² is an alkylene containing from 1 to about 6 carbon atoms, R^ is H or alkyl, aryl, or alkaryl containing from about 1 to about 10 carbon atoms, and L is any suitable leaving group. A leaving group is any group that is displaced from the bleach activator as a consequence of the nucleophilic attack on the bleach activator by the perhydrolysis anion. A preferred leaving group is phenol sulfonate.

Preferred examples of bleach activators of the above formulae include (6- octanamido-caproyl)oxybenzenesulfonate, (6-nonanamidocaproyI) oxybenzenesulfonate, (6-decanamido-caproyl)oxybenzenesuIfonate and mixtures thereof as described in the hereinbefore referenced U.S. Patent 4,634,551. Such mixtures are characterized herein as alkamido- caproy l)oxy benzenesul fonate .

Another class of useful bleach activators comprises the benzoxazin-type activators disclosed by Hodge et al. in U.S. Patent 4,966, 723, Issued October 30,

1990, incorporated herein by reference. A highly preferred activator of the benzoxazin-type is:

Still another class of useful bleach activators includes the acyl lactam activators, especially acyl caprolactams and acyl valerolactams ofthe formulae:

wherein R^ is H or an alkyl, aryl, alkoxyaryl, or alkaryl group containing from 1 to about 12 carbon atoms. Highly preferred lactam activators include benzoyl caprolactam, octanoyl caprolactam, 3,5,5-trimethylhexanoyl caprolactam, nonanoyl caprolactam, decanoyl caprolactam, undecenoyl caprolactam, benzoyl valerolactam, octanoyl valerolactam, decanoyl valerolactam, undecenoyl valerolactam, 3,5,5- trimethylhexanoyl valerolactam and mixtures thereof. See also U.S. Patent 4,545,784, Issued to Sanderson, October 8, 1985, incorporated herein by reference, which discloses acyl caprolactams, including benzoyl caprolactam, adsorbed into sodium perborate.

Of all the foregoing peroxygen bleach activators, the preferred ones for use in this invention are nonanoyloxybenzene sulfonate (NOBS), tetraacetyl ethylene diamine (TAED) and (Cg.jo alkamido-caproyl) oxybenzene sulfonate. Sodium NOBS is the most preferred.

(B) Inert Carrier Material

The bleach activator material may optionally be combined with an inert carrier material. An "inert" material is one which does not chemically react with the activator material.

Suitable inert carrier materials can include non-reactive nonionic surfactants, polyethylene glycols, e.g., PEG 4000, fatty acids, anionic surfactants such as Cι ø-16 linear alkyl benzene sulfonates (LAS), solid polyacrylate polymers and copolymers, solid organic acids such as citric acid, citrates, e.g., sodium citrate, and mixtures of these inert materials. Such inert materials are described in greater detail in Murphy

et al; U.S. Patent 4,486,327; Issued December 4, 1984, which patent is incorporated herein by reference.

The activator and inert carrier material can be combined by any technique which forms an intimate combination of activator and carrier. This can be, for example, via simple dry mixing or blending, co-extrusion, agglomeration, and the like.

If utilized, the inert carrier material can comprises up to about 80% by weight of the activator/carrier combination that serves as the core material for the coated activator particles herein. More preferably, the inert carrier will comprises from about 10% to 50% by weight ofthe activator/carrier combination.

(C) Activator Particle Coating Material

The activator material as hereinbefore described, optionally in combination with inert carrier material, is coated with a coating material which completely encapsulates the particles containing activator material. The coating material must be one which is insoluble in the non-aqueous solvents used to form the non-aqueous fabric cleaning compositions herein. Though insoluble in non-aqueous solvents, the coating material should be readily soluble in aqueous solutions such as the fabric laundering and/or bleaching solutions which are formed from the non-aqueous fabric cleaning products herein.

Typically the coating material will be an organic or inorganic salt. Such salts are those selected from the water soluble citrates, sulfates, carbonates, silicates, halides, chromates and the like. Alkali metal salts, e.g., sodium and potassium of these anionic moieties are preferred. Calcium and magnesium salts may also be used. The most preferred coating materials are sodium citrate and sodium sulfate.

(D) Coated Particle Preparation

Coating of the solid core material comprising bleach activator can be accomplished using any conventional coating techniques which provide a continuous, unbroken coating around the core material. However applied, the coating material must completely surround the activator-containing core and insulate the activator material therein from contact with the non-aqueous solution in the non¬ aqueous cleaning products in which such coated activator particles are employed. Coating of this type is thus distinct from agglomeration or other forms of particle preparation which would not necessarily result in complete encapsulation of the activator-containing particle with a protective coating.

Complete coating of the activator-containing core material is best accomplished by a fluidized bed coating/drying operation. In such a procedure, an aqueous solution of the particle coating material is sprayed onto the particles to be coated in a fluidized bed arrangement such as for example in a Wurster coater. The sprayed particles in the fluidized bed are then dried with dehumidified air maintained at a temperature below the melting point of the activator, e.g., below about 60°C for NOBS. In this manner, a coating which comprises from about 5% to 80% by weight of the coated particles, more preferably from about 10% to 40% by weight ofthe coated particles, can be obtained.

The coated activator particles which result will frequently range in size from about 20 to 800 microns. More preferably, the coated activator particles of from 20 to 400 microns can be realized. Very small coated particles ranging in size from about 20 to 80 microns, are especially advantageous for suspension in liquid non¬ aqueous detergent and bleach compositions in that they minimize the suspension requirement for the particles in the liquid compositions and in that they produce improved consumer aesthetics.

NON-AQUEOUS CLEANING COMPOSITIONS

The coated bleach activator particles as hereinbefore described are utilized in non-aqueous liquid fabric cleaning compositions which are formed from one or more non-aqueous organic solvents in which are suspended particles of inorganic peroxygen bleaching agent, the coated bleach activator particles and optionally a number of other types of solid insoluble particle materials. Such non-aqueous compositions will generally include one or more structurant materials, generally surfactants, which serve to enhance the ability of the compositions to keep particulate material suspended and dispersed therein and throughout. The several essential and optional components of such compositions, in addition to the coated activator particles hereinbefore described, are described in detail as follows:

(A) Non-aqueous Organic Diluents

The major component of the liquid phase of the detergent compositions herein comprises one or more non-aqueous organic diluents. The non-aqueous organic diluents used in the fabric cleaning compositions of this invention may be either surface active, i.e., surfactant, liquids or non-aqueous, non-surfactant liquids referred to herein as non-aqueous solvents. The term "solvent" is used herein to connote the non-aqueous liquid portion of the compositions herein. While some of the essential and/or optional components of the compositions herein may actually dissolve in the

"solvent"-containing liquid phase, other components will be present as particulate material dispersed within and throughout the "so!vent"-containing liquid phase. Thus the term "solvent" is not meant to require that the solvent material be capable of actually dissolving all ofthe cleaning composition components added thereto.

Preferably, the liquid phase of the compositions herein, i.e., the non-aqueous liquid diluent component, will comprise both non-aqueous liquid surfactants and non-surfactant non-aqueous solvents.

i) Non-aqueous Surfactant Liquids

Suitable types of non-aqueous surfactant liquids which can be used to form the liquid phase of the compositions herein include the alkoxylated alcohols, ethylene oxide (EO)-propylene oxide (PO) block polymers, polyhydroxy fatty acid amides, alkylpolysaccharides, and the like. Such normally liquid surfactants are those having an HLB ranging from 3 to 17. Most preferred of the surfactant liquids are the alcohol alkoxylate nonionic surfactants.

Alcohol alkoxylates are materials which correspond to the general formula:

R ¹ (C _m H _2m O) _n OH wherein R* is a Cg - C\ alkyl group, m is from 2 to 4, and n ranges from about 2 to 12. Preferably R^ is an alkyl group, which may be primary or secondary, that contains from about 9 to 15 carbon atoms, more preferably from about 10 to 14 carbon atoms. Preferably also the alkoxylated fatty alcohols will be ethoxylated materials that contain from about 2 to 12 ethylene oxide moieties per molecule, more preferably from about 3 to 10 ethylene oxide moieties per molecule.

The alkoxylated fatty alcohol materials useful in the liquid phase will frequently have a hydrophilic-lipophilic balance (HLB) which ranges from about 3 to 17. More preferably, the HLB of this material will range from about 6 to 15, most preferably from about 8 to 15.

Examples of fatty alcohol alkoxylates useful in or as the non-aqueous liquid phase ofthe compositions herein will include those which are made from alcohols of 12 to 15 carbon atoms and which contain about 7 moles of ethylene oxide. Such materials have been commercially marketed under the trade names Neodol 25-7 and Neodol 23-6.5 by Shell Chemical Company. Other useful Neodols include Neodol 1-5, an ethoxylated fatty alcohol averaging 1 1 carbon atoms in its alkyl chain with about 5 moles of ethylene oxide; Neodol 23-9, an ethoxylated primary C J2 - C13 alcohol having about 9 moles of ethylene oxide and Neodol 91-10, an ethoxylated Co. - Cn primary alcohol having about 10 moles of ethylene oxide. Alcohol ethoxylates of this type have also been marketed by Shell Chemical Company under

the Dobanol tradenarne. Dobanol 91-5 is an ethoxylated C9-C1 1 fatty alcohol with an average of 5 moles ethylene oxide and Dobanol 25-7 is an ethoxylated C i2-C _] 5 fatty alcohol with an average of 7 moles of ethylene oxide per mole of fatty alcohol.

Other examples of suitable ethoxylated alcohols include Tergitol 15-S-7 and Tergitol 15-S-9 both of which are linear secondary alcohol ethoxylates that have been commercially marketed by Union Carbide Corporation. The former is a mixed ethoxylation product of C\ \ to C 5 linear secondary alkanol with 7 moles of ethylene oxide and the latter is a similar product but with 9 moles of ethylene oxide being reacted.

Other types of alcohol ethoxylates useful in the present compositions are higher molecular weight nonionics, such as Neodol 45-1 1, which are similar ethylene oxide condensation products of higher fatty alcohols, with the higher fatty alcohol being of 14-15 carbon atoms and the number of ethylene oxide groups per mole being about 1 1. Such products have also been commercially marketed by Shell Chemical Company.

If alcohol alkoxylate nonionic surfactant is utilized as part of the non¬ aqueous liquid phase in the cleaning compositions herein, it will preferably be present to the extent of from about 1 % to 60% of the composition liquid phase. More preferably, the alcohol alkoxylate component will comprise about 5% to 40% of the liquid phase. Most preferably, the essentially utilized alcohol alkoxylate component will comprise from about 5% to 35% of the cleaning composition liquid phase. Utilization of alcohol alkoxylate in these concentrations in the liquid phase corresponds to an alcohol alkoxylate concentration in the total composition of from about 1 % to 60% by weight, more preferably from about 2% to 40% by weight, and most preferably from about 5% to 25% by weight, ofthe composition.

Another type of non-aqueous surfactant liquid which may be utilized in this invention are the ethylene oxide (EO) - propylene oxide (PO) block polymers. Materials of this type are well known nonionic surfactants which have been marketed under the tradenarne Pluronic. These materials are formed by adding blocks of ethylene oxide moieties to the ends of polypropylene glycol chains to adjust the surface active properties of the resulting block polymers. EO-PO block polymer nonionics of this type are described in greater detail in Davidsohn and Milwidsky; Synthetic Detergents. 7th Ed.; Longman Scientific and Technical (1987) at pp. 34-36 and pp. 189-191 and in U.S. Patents 2,674,619 and 2,677,700. All of these publications are incorporated herein by reference. These Pluronic type nonionic surfactants are also believed to function as effective suspending agents for

the particulate material which is dispersed in the liquid phase of the detergent compositions herein.

Another possible type of non-aqueous surfactant liquid useful in the compositions herein comprises polyhydroxy fatty acid amide surfactants. Materials of this type of nonionic surfactant are those which conform to the formula:

O CpH ₂ p+l II I R— C-N-Z wherein R is a C9.17 alkyl or alkenyl, p is from 1 to 6, and Z is glycityl derived from a reduced sugar or alkoxylated derivative thereof. Such materials include the Cl2"Cl8 N-methyl glucamides. Examples are N-methyl N-1-deoxyglucityl cocoamide and N-methyl N- 1 -deoxyglucityl oleamide. Processes for making polyhydroxy fatty acid, amides are know and can be found, for example, in Wilson, U.S. Patent 2,965,576 and Schwartz, U.S. Patent 2,703,798, the disclosures of which are incorporated herein by reference. The materials themselves and their preparation are also described in greater detail in Honsa, U.S. Patent 5,174,937, Issued December 26, 1992, which patent is also incorporated herein by reference.

The amount of total liquid surfactant in the non-aqueous liquid phase herein will be determined by the type and amounts of other composition components and by the desired composition properties. Generally, the liquid surfactant can comprise from about 35% to 70% of the non-aqueous liquid phase ofthe compositions herein. More preferably, the liquid surfactant will comprise from about 50% to 65% of the non-aqueous liquid phase. This corresponds to a non-aqueous liquid surfactant concentration in the total composition of from about 15% to 70% by weight, more preferably from about 20% to 50% by weight, ofthe composition.

ii) Non-surfactant Non-aqueous Organic Solvents

The liquid phase of the cleaning compositions herein may also comprise one or more non-surfactant, non-aqueous organic solvents. Such non-surfactant non¬ aqueous liquids are preferably those of low polarity. For purposes of this invention, "low-polarity" liquids are those which have little, if any, tendency to dissolve one of the essential types of particulate material used in the compositions herein, i.e., the peroxygen bleaching agents, sodium perborate or sodium percarbonate. Thus relatively polar solvents such as ethanol are preferably not utilized. Suitable types of low-polarity solvents useful in the non-aqueous liquid detergent compositions herein do include non- vicinal C4-C8 alkylene glycols, alkylene glycol mono lower alkyl

ethers, lower molecular weight polyethylene glycols. lower molecular weight methyl esters and amides, and the like.

A preferred type of non-aqueous, low-polarity solvent for use in the compositions herein comprises the non-vicinal C-j-Cg branched or straight chain alkylene glycols. Materials of this type include hexylene glycol (4-methyl-2,4- pentanediol), 1 ,6-hexanediol, 1,3-butylene glycol and 1,4-butylene glycol. Hexylene glycol is the most preferred.

Another preferred type of non-aqueous, low-polarity solvent for use herein comprises the mono-, di-, tri-, or tetra- C2-C3 alkylene glycol mono C2-Cg alkyl ethers. The specific examples of such compounds include diethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, dipropolyene glycol monoethyl ether, and dipropylene glycol monobutyl ether. Diethylene glycol monobutyl ether, dipropylene glycol monobutyl ether and butoxy-propoxy-propanol (BPP) are especially preferred. Compounds of the type have been commercially marketed under the tradenames Dowanol, Carbitol, and Cellosolve.

Another preferred type of non-aqueous, low-polarity organic solvent useful herein comprises the lower molecular weight polyethylene glycols (PEGs). Such materials are those having molecular weights of at least about 150. PEGs of molecular weight ranging from about 200 to 600 are most preferred.

Yet another preferred type of non-polar, non-aqueous solvent comprises lower molecular weight methyl esters. Such materials are those of the general formula: R ¹ -C(O)-OCH3 wherein R^ ranges from 1 to about 18. Examples of suitable lower molecular weight methyl esters include methyl acetate, methyl propionate, methyl octanoate, and methyl dodecanoate.

The non-aqueous, generally low-polarity, non-surfactant organic solvent(s) employed should, of course, be compatible and non-reactive with other composition components, e.g., bleach and/or coated activators, used in the liquid detergent compositions herein. Such a solvent component is preferably utilized in an amount of from about 1% to 70% by weight of the liquid phase. More preferably, a non¬ aqueous, low-polarity, non-surfactant solvent will comprise from about 10% to 60% by weight ofthe liquid phase, most preferably from about 20% to 50% by weight, of the liquid phase of the composition. Utilization of non-surfactant solvent in these concentrations in the liquid phase corresponds to a non-surfactant solvent concentration in the total composition of from about 1% to 50% by weight, more preferably from about 5% to 40% by weight, and most preferably from about 10% to 30% by weight, of the composition.

iii) Blends of Surfactant and Non-surfactant Solvents

In systems which employ both non-aqueous surfactant liquids and non¬ aqueous non-surfactant solvents, the ratio of surfactant to non-surfactant liquids, e.g., the ratio of alcohol alkoxylate to low polarity solvent, within the liquid phase can be used to vary the rheological properties of the detergent compositions eventually formed. Generally, the weight ratio of surfactant liquid to non-surfactant organic solvent will range about 50: 1 to 1 :50. More preferably, this ratio will range from about 3: 1 to 1 :3.

(B) Peroxygen Bleaching Agent Particles

The non-aqueous fabric cleaning compositions of this invention essentially comprise from about 2% to 15% by weight of the composition of particles of peroxygen bleaching agent suspended in the non-aqueous liquid phase. More preferably, particles of peroxygen bleaching agent will comprise from about 2% to 10% by weight of the composition. The peroxygen bleaching agents which are generally used in combination with the essentially present bleach activator particles are inorganic compounds.

Suitable inorganic peroxygen compounds include alkali metal perborate and percarbonate materials, most preferably the percarbonates. For example, sodium perborate (e.g. mono- or tetra-hydrate) can be used. Suitable inorganic bleaching agents can also include sodium or potassium carbonate peroxyhydrate and equivalent "percarbonate" bleaches, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide. Persulfate bleach (e.g., OXONE, manufactured commercially by DuPont) can also be used. Frequently inorganic peroxygen bleaches will be coated with silicate, borate, sulfate or water-soluble surfactants. For example, coated percarbonate particles are available from various commercial sources such as FMC, Solvay Interox, Tokai Denka and Degussa.

Peroxygen bleaching agents are suspended in the non-aqueous liquid phase of the cleaning compositions herein in the form of solid insoluble particles. Such particles generally range in average size from about 10 to 800 microns. More preferably, the dispersed and suspended particles of inorganic peroxygen bleaching agents will range in average size from about 10 to 400 microns.

(C) Coated Bleach Activator Particles

The non-aqueous cleaning compositions herein also essentially contain the coated bleach activator particles hereinbefore described. Such coated bleach activators can comprise from about 2% to 20%, more preferably from about 4% to

10%, by weight of the composition. Frequently, activators are employed such that the molar ratio of bleaching agent to activator ranges from about 1 :1 to 10: 1 , more preferably from about 1.5: 1 to 5: 1.

(D) Optional Composition Components

In addition to the hereinbefore-described essential non-aqueous solvent, peroxygen bleaching agent and coated bleach activator particles, the non-aqueous cleaning compositions of the present invention can, and preferably will, contain a wide variety of optional ingredients. Such optional components may be in either liquid or solid form. The optional components may either dissolve in the liquid phase or may be dispersed within the liquid phase in the form of fine particles or droplets. Some ofthe materials which may optionally be utilized in the compositions herein are described in greater detail as follows:

(a) Optional Surfactants

Besides the liquid non-aqueous surfactant materials hereinbefore described as possible components of the composition liquid phase, the cleaning compositions herein may also contain other types of surfactant materials. Such additional optional surfactants must, of course, be compatible with other composition components and must not substantially adversely affect composition rheology, stability or performance. Surfactants in general enhance the stain and soil remove performance of the cleaning compositions to which they are added. Surfactants can also be selected to add structure to the non-aqueous cleaning compositions herein. Optional surfactants can be of the anionic, nonionic, cationic, and or amphoteric type.

Preferred optional surfactants are the anionic surfactants such as the alkyl sulfates, the alkyl polyethoxylene sulfates and the linear alkyl benzene sulfonates. Another common type of anionic surfactant material which may be optionally added to the detergent compositions herein comprises carboxylate-type anionics. Carboxylate-type anionics include the Ciø-Ci alkyl alkoxy carboxylates (especially the EO 1 to 5 ethoxycarboxylates) and the Cio-Cj sarcosinates, especially oleoyl sarcosinate. Yet another common type of anionic surfactant material which may be optionally employed comprises other sulfonated anionic surfactants such as the Cg-Cj paraffin sulfonates and the Cg-Cj g olefin sulfonates. Anionic surfactants can optionally comprise from about 1% to 30% by weight of the compositions herein.

As indicated, one preferred type of optional anionic surfactant comprises primary or secondary alkyl sulfate anionic surfactants. Such surfactants are those produced by the sulfation of higher C -C20 fatty alcohols.

Conventional primary alkyl sulfate surfactants have the general formula

ROSO ₃ -M ⁺ wherein R is typically a linear Cg - C20 hydrocarbyl group, which may be straight chain or branched chain, and M is a water-solubilizing cation. Preferably R is a C 10 - C14 alkyl, and M is alkali metal. Most preferably R is about C12 and M is sodium.

Conventional secondary alkyl sulfates may also be utilized as an optional anionic surfactant component of the solid phase of the compositions herein. Conventional secondary alkyl sulfate surfactants are those materials which have the sulfate moiety distributed randomly along the hydrocarbyl "backbone" of the molecule. Such materials may be depicted by the structure:

CH3(CH ₂ )n(CHOSO ₃ -M ⁺ ) (CH ₂ ) _m CH ₃ wherein m and n are integers of 2 or greater and the sum of m + n is typically about 9 to 15, and M is a water-solubilizing cation.

If utilized, alkyl sulfates will generally comprise from about 1% to 30% by weight of the composition, more preferably from about 5% to 25% by weight of the composition. Non-aqueous liquid detergent compositions containing alkyl sulfates, peroxygen bleaching agents, and bleach activators are described in greater detail in Kong-Chan et al.; WO 96/10073; Publiched April 4, 1996, which application is incorporated herein by reference.

Another preferred type of anionic surfactant material which may be optionally added to the non-aqueous cleaning compositions herein comprises the alkyl polyalkoxylate sulfates. Alkyl polyalkoxylate sulfates are also known as alkoxylated alkyl sulfates or alkyl ether sulfates. Such materials are those which correspond to the formula

R2-O-(C _m H _2m O) _n -SO ₃ M

wherein R ² is a C10-C22 alkyl group, m is from 2 to 4, n is from about 1 to 15, and M is a salt- forming cation. Preferably, R ² is a C^-Cj alkyl, m is 2, n is from about 1 to 10, and M is sodium, potassium, ammonium, alkylammonium or alkanolammonium. Most preferably, R ² is a C^-Cjg, m is 2, n is from about 1 to 6, and M is sodium. Ammonium, alkylammonium and alkanolammonium

counterions are preferably avoided when used in the compositions herein because of incompatibility with the peroxygen bleaching agent.

If utilized, alkyl polyalkoxylate sulfates can also generally comprise from about 1% to 30% by weight of the composition, more preferably from about 5% to 25% by weight of the composition. Non-aqueous liquid detergent compositions containing peroxygen bleaching agents, bleach activators and alkyl polyalkoxylate sulfates, in combination with polyhydroxy fatty acid amides, are described in greater detail in Boutique et al; PCT Application No. PCT/US96/04223, which application is incorporated herein by reference.

The most preferred type of anionic surfactant for optional use in the compositions herein comprises the linear alkyl benzene sulfonate (LAS) surfactants. In particular, such LAS surfactants can be formulated into a specific type of anionic surfactant-containing powder which is especially useful for incorporation into the non-aqueous liquid cleaning compositions of the present invention. Such a powder comprises two distinct phases. One of these phases is insoluble in the non-aqueous organic liquid diluents used in the compositions herein; the other phase is soluble in the non-aqueous organic liquids. It is the insoluble phase of this anionic surfactant- containing powder which can be dispersed in the non-aqueous liquid phase of the compositions herein and which forms a network of aggregated small particles that allows the final product to stably suspend other additional solid particulate materials in the composition.

Such a preferred anionic surfactant-containing powder is formed by co-drying an aqueous slurry which essentially contains a) one of more alkali metal salts of ClO-16 line r alkyl benzene sulfonic acids; and b) one or more non-surfactant diluent salts. Such a slurry is dried to a solid material, generally in powder form, which comprises both the soluble and insoluble phases.

The linear alkyl benzene sulfonate (LAS) materials used to form the preferred anionic surfactant-containing powder are well known materials. Such surfactants and their preparation are described for example in U.S. Patents 2,220,099 and 2,477,383, incorporated herein by reference. Especially preferred are the sodium and potassium linear straight chain alkylbenzene sulfonates in which the average number of carbon atoms in the alkyl group is from about 1 1 to 14. Sodium C\ \- Ci4, e.g., Ci2- LAS is especially preferred. The alkyl benzene surfactant anionic surfactants are generally used in the powder-forming slurry in an amount from about 20 to 70% by weight of the slurry, more preferably from about 30% to 60% by weight ofthe slurry.

The powder-forming slurry also contains a non-surfactant, organic or inorganic salt component that is co-dried with the LAS to form the two-phase anionic surfactant-containing powder. Such salts can be any of the known sodium, potassium or magnesium halides, sulfates, citrates, carbonates, sulfates, borates, succinates, sulfo-succinates and the like. Sodium sulfate, which is generally a bi- product of LAS production, is the preferred non-surfactant diluent salt for use herein. Salts which function as hydrotropes such as sodium sulfo-succinate may also usefully be included. The non-surfactant salts are generally used in the aqueous slurry, along with the LAS, in amounts ranging from about 1 to 12% by weight of the slurry, more preferably from about 2% to 10% by weight ofthe slurry. Salts that act as hydrotropes can preferably comprise up to about 3% by weight ofthe slurry.

The aqueous slurry containing the LAS and diluent salt components hereinbefore described can be dried to form the anionic surfactant-containing powder preferably added to the non-aqueous solvents in order to prepare a structured liquid phase within the compositions herein. Any conventional drying technique, e.g., spray drying, drum drying, etc., or combination of drying techniques, may be employed. Drying should take place until the residual water content of the solid material which forms is within the range of from about 0.5% to 4% by weight, more preferably from about 1% to 3% by weight.

The anionic surfactant-containing powder produced by the drying operation constitutes two distinct phases, one of which is soluble in the inorganic liquid diluents used herein and one of which is insoluble in the diluents. The insoluble phase in the anionic surfactant-containing powder generally comprises from about 10% to 25% by weight of the powder, more preferably from about 15% to 25% by weight of a powder.

After it is dried to the requisite extent, the combined LAS/salt material can be converted to flakes or powder form by any known suitable milling or comminution process. Generally at the time such material is combined with the non-aqueous organic solvents to form the structured liquid phase of the compositions herein, the particle size of this powder will range from 0.1 to 2000 microns, more preferably from about 0.1 to 1000 microns.

A structured, surfactant-containing liquid phase of the preferred detergent with bleach compositions herein can be prepared by combining the non-aqueous organic diluents hereinbefore described with the anionic surfactant-containing powder as hereinbefore described. Such combination results in the formation of a structured surfactant-containing liquid phase. Conditions for making this combination of preferred structured liquid phase components are described more fully hereinafter in

the "Composition Preparation and Use" section. As previously noted, the formation of a structured, surfactant-containing liquid phase permits the stable suspension of the peroxygen bleaching agent and coated bleach activator particles as well as additional functional particulate solid materials within the preferred cleaning compositions of this invention.

(b) Optional Builder Materials

Another possible type of optionally utilized particulate material which can be suspended in the non-aqueous liquid cleaning compositions herein comprises an organic or inorganic detergent builder material which serves to counteract the effects of calcium, or other ion, water hardness encountered during laundering/bleaching use of the compositions herein. Examples of such organic materials include the alkali metal citrates (in addition to those used as activator coating or inert material), succinates, malonates, fatty acids, carboxymethylsuccinates, carboxylates, polycarboxylates and polyacetyl carboxylates. Specific examples include sodium, potassium and lithium salts of oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids and citric acid. Other examples of organic phosphonate type sequestering agents such as those which have been sold by Monsanto under the Dequest tradenarne and alkanehydroxy phosphonates. Citrate salts are highly preferred.

Other suitable organic builders include the higher molecular weight polymers and copolymers known to have builder properties. For example, such materials include appropriate polyacrylic acid, polymaleic acid, and polyacrylic/polymaleic acid copolymers and their salts, such as those sold by BASF under the Sokalan trademark.

Another suitable type of organic builder comprises the water-soluble salts of higher fatty acids, i.e., "soaps". These include alkali metal soaps such as the sodium, potassium, ammonium, and alkylolammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms, and preferably from about 12 to about 18 carbon atoms. Soaps can be made by direct saponifϊcation of fats and oils or by the neutralization of free fatty acids. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap.

The cleaning compositions herein may also optionally contain one or more types of inorganic detergent builders beyond those listed hereinafter that also function as alkalinity sources. Such optional inorganic builders can include, for

example, aluminosilicates such as zeolites. Aluminosilicate zeolites, and their use as detergent builders are more fully discussed in Corkill et al., U.S. Patent No. 4,605,509; Issued August 12, 1986, the disclosure of which is incorporated herein by reference. Also crystalline layered silicates, such as those discussed in this '509 U.S. patent, are also suitable for use in the detergent compositions herein.

If utilized as optionally added particulate material, insoluble organic or inorganic detergent builders can generally comprise from about 2% to 20% by weight of the compositions herein. More preferably, such builder material can comprise from about 4% to 15% by weight ofthe composition.

(c.Optional Inorganic Alkalinity Sources

Another possible type of optionally added particulate material which can be suspended in the non-aqueous liquid cleaning compositions herein can comprise a material which serves to render aqueous washing and bleaching solutions formed from such compositions generally alkaline in nature. Such materials may or may not also act as detergent builders, i.e., as materials which counteract the adverse effect of water hardness on detergency performance.

Examples of suitable alkalinity sources include water-soluble alkali metal carbonates, bicarbonates, borates, silicates and metasilicates. Although not preferred for ecological reasons, water-soluble phosphate salts may also be utilized as alkalinity sources. These include alkali metal pyrophosphates, orthophosphates, polyphosphates and phosphonates. Of all of these alkalinity sources, alkali metal carbonates such as sodium carbonate are the most preferred.

The alkalinity source, if in the form of a hydratable salt, may also serve as a desiccant in the non-aqueous liquid detergent compositions herein. The presence of an alkalinity source which is also a desiccant may provide benefits in terms of chemically stabilizing those composition components such as the peroxygen bleaching agent which may be susceptible to deactivation by water.

If utilized an optionally added particulate material component, the alkalinity source will generally comprise from about 1% to 25% by weight ofthe compositions herein. More preferably, the alkalinity source can comprise from about 2% to 15% by weight ofthe composition. Such materials, while water-soluble, will generally be insoluble in the non-aqueous cleaning compositions herein. Thus such materials will generally be dispersed in the non-aqueous liquid phase of the compositions herein in the form of discrete particles.

(d) Optional Enzymes

The cleaning compositions herein may also optionally contain one or more types of detergent enzymes. Such enzymes can include proteases, amylases, cellulases and upases. Such materials are known in the art and are commercially available. They may be incorporated into the non-aqueous liquid detergent compositions herein in the form of suspensions, "marumes" or "prills". Another suitable type of enzyme comprises those in the form of slurries of enzymes in nonionic surfactants, e.g., the enzymes marketed by Novo Nordisk under the tradename "SL" or the micro encapsulated enzymes marketed by Novo Nordisk under the tradename "LDP."

Enzymes added to the compositions herein in the form of conventional enzyme prills are especially preferred for use herein. Such prills will generally range in size from about 100 to 1,000 microns, more preferably from about 200 to 800 microns and will be suspended throughout the non-aqueous liquid phase of the composition. Prills in the compositions of the present invention have been found, in comparison with other enzyme forms, to exhibit especially desirable enzyme stability in terms of retention of enzymatic activity over time. Thus, compositions which utilize enzyme prills need not contain conventional enzyme stabilizing such as must frequently be used when enzymes are incorporated into aqueous liquid detergents.

If employed, enzymes will normally be incorporated into the non-aqueous liquid compositions herein at levels sufficient to provide up to about 10 mg by weight, more typically from about 0.01 mg to about 5 mg, of active enzyme per gram of the composition. Stated otherwise, the non-aqueous liquid cleaning compositions herein will typically comprise from about 0.001% to 5%, preferably from about 0.01% to 1% by weight, of a commercial enzyme preparation. Protease enzymes, for example, are usually present in such commercial preparations at levels sufficient to provide from 0.005 to 0.1 Anson units (AU) of activity per gram of composition.

(e) Optional Chelating Agents

The cleaning compositions herein may also optionally contain a chelating agent which serves to chelate metal ions, e.g., iron and/or manganese, within the non-aqueous detergent compositions herein. Such chelating agents thus serve to form complexes with metal impurities in the composition which would otherwise tend to deactivate composition components such as the peroxygen bleaching agent. Useful chelating agents can include amino carboxylates, phosphonates, amino phosphonates, polyfunctionally-substituted aromatic chelating agents and mixtures thereof.

Amino carboxylates useful as optional chelating agents include ethylenediaminetetraacetates, N-hydroxyethyl-ethylenediaminetriacetates, nitrilotriacetates, ethylene-diamine tetrapropionates, triethylenetetraaminehexacetates, diethylenetriaminepentaacetates, ethylenediaminedisuccinates and ethanol diglycines. The alkali metal salts of these materials are preferred.

Amino phosphonates are also suitable for use as chelating agents in the compositions of this invention when at least low levels of total phosphorus are permitted in detergent compositions, and include ethylenediaminetetrakis (methylene-phosphonates) as DEQUEST. Preferably, these amino phosphonates do not contain alkyl or alkenyl groups with more than about 6 carbon atoms.

Preferred chelating agents include hydroxy-ethyldiphosphonic acid (HEDP), diethylene triamine penta acetic acid (DTPA), ethylenediamine disuccinic acid (EDDS) and dipicolinic acid (DPA) and salts thereof. The chelating agent may, of course, also act as a detergent builder during use of the compositions herein for fabric laundering/bleaching. The chelating agent, if employed, can comprise from about 0.1% to 4% by weight of the compositions herein. More preferably, the chelating agent will comprise from about 0.2% to 2% by weight of the cleaning compositions herein.

(f) Optional Thickening, Viscosity Control and/or Dispersing Agents

The non-aqueous cleaning compositions herein may also optionally contain a polymeric material which serves to enhance the ability of the composition to maintain its solid particulate components in suspension. Such materials may thus act as thickeners, viscosity control agents and/or dispersing agents. Such materials are frequently polymeric polycarboxylates but can include other polymeric materials such as polyvinylpyrrolidone (PVP). Insoluble materials like fumed silica and titanium dioxide may also be used to enhance the elasticity of any structured liquid phase that is present.

Polymeric polycarboxylate materials can be prepared by polymerizing or copolymerizing suitable unsaturated monomers, preferably in their acid form. Unsaturated monomeric acids that can be polymerized to form suitable polymeric polycarboxylates include acrylic acid, maleic acid (or maleic anhydride), fumaric acid, itaconic acid, aconitic acid, mesaconic acid, citraconic acid and methylenemalonic acid. The presence in the polymeric polycarboxylates herein of monomeric segments, containing no carboxylate radicals such as vinyl methyl ether,

styrene, ethylene, etc. is suitable provided that such segments do not constitute more than about 40% by weight ofthe polymer.

Particularly suitable polymeric polycarboxylates can be derived from acrylic acid. Such acrylic acid-based polymers which are useful herein are the water- soluble salts of polymerized acrylic acid. The average molecular weight of such polymers in the acid form preferably ranges from about 2,000 to 10,000, more preferably from about 4,000 to 7,000, and most preferably from about 4,000 to 5,000. Water-soluble salts of such acrylic acid polymers can include, for example, the alkali metal, salts. Soluble polymers of this type are known materials. Use of polyacrylates of this type in detergent compositions has been disclosed, for example, Diehl, U.S. Patent 3,308,067, issued March 7, 1967. Such materials may also perform a builder function.

If utilized, the optional thickening, viscosity control and/or dispersing agents should be present in the compositions herein to the extent of from about 0.1% to 4% by weight. More preferably, such materials can comprise from about 0.5% to 2% by weight ofthe cleaning compositions herein.

(g) Optional Clay Soil Removal/Anti-redeposition Agents The compositions of the present invention can also optionally contain water- soluble ethoxylated amines having clay soil removal and anti-redeposition properties. If used, soil materials can contain from about 0.01% to about 5% by weight ofthe compositions herein.

The most preferred soil release and anti-redeposition agent is ethoxylated tetraethylenepentamine. Exemplary ethoxylated amines are further described in U.S. Patent 4,597,898, VanderMeer, issued July 1, 1986. Another group of preferred clay soil removal-anti-redeposition agents are the cationic compounds disclosed in European Patent Application 1 11,965, Oh and Gosselink, published June 27, 1984. Other clay soil removal/anti-redeposition agents which can be used include the ethoxylated amine polymers disclosed in European Patent Application 1 1 1 ,984, Gosselink, published June 27, 1984; the zwitterionic polymers disclosed in European Patent Application 112,592, Gosselink, published July 4, 1984; and the amine oxides disclosed in U.S. Patent 4,548,744, Connor, issued October 22, 1985. Other clay soil removal and/or anti-redeposition agents known in the art can also be utilized in the compositions herein. Another type of preferred anti-redeposition agent includes the carboxy methyl cellulose (CMC) materials. These materials are well known in the art.

(h) Optional Liquid Bleach Activators

The cleaning compositions herein may also optionally contain bleach activators which are liquid in form at room temperature and which can be added as liquids to the non-aqueous liquid phase of the cleaning compositions herein. One such liquid bleach activator is acetyl triethyl citrate (ATC). Other examples include glycerol triacetate and nonanoyl valerolactam. Liquid bleach activators can be dissolved in the non-aqueous liquid phase ofthe compositions herein.

(i) Optional Brighteners, Suds Suppressors, Dyes and/or Perfumes The cleaning compositions herein may also optionally contain conventional brighteners, suds suppressors, bleach catalysts, dyes and/or perfume materials. Such brighteners, suds suppressors, silicone oils, bleach catalysts, dyes and perfumes must, of course, be compatible and non-reactive with the other composition components in a non-aqueous environment. If present, brighteners suds suppressors, dyes and/or perf mes will typically comprise from about 0.0001% to 2% by weight of the compositions herein. Suitable bleach catalysts include the manganese based complexes disclosed in US 5,246,621, US 5,244,594, US 5,114,606 and US 5,1 14,611.

NON-AQUEOUS COMPOSITION FORM

As indicated, the non-aqueous liquid cleaning compositions herein are in the form of bleaching agent, coated bleach activator and possibly other materials in particulate form as a solid phase suspended in and dispersed throughout a preferably surfactant-containing, non-aqueous liquid phase. Generally, the structured non¬ aqueous liquid phase will comprise from about 45% to 95%, more preferably from about 50% to 90%, by weight of the composition with the dispersed additional solid materials comprising from about 5% to 55%, more preferably from about 10% to 50%, by weight ofthe composition.

The particulate-containing liquid cleaning compositions of this invention are substantially non-aqueous (or anhydrous) in character. While very small amounts of water may be incorporated into such compositions as an impurity in the essential or optional components, the amount of water should in no event exceed about 5% by weight of the compositions herein. More preferably, water content of the non¬ aqueous cleaning compositions herein will comprise less than about 1% by weight.

The particulate-containing non-aqueous liquid cleaning compositions herein will be relatively viscous and phase stable under conditions of commercial

marketing and use of such compositions. Frequently the viscosity of the compositions herein will range from about 300 to 5,000 cps, more preferably from about 500 to 3,000 cps. For purposes of this invention, viscosity is measured with a Carrimed CSL2 Rheometer at a shear rate of 20 sec'l .

COMPOSITION PREPARATION AND USE

The non-aqueous liquid cleaning compositions herein can be prepared by first forming a non-aqueous liquid phase which is preferably structured and surfactant- containing and by thereafter adding to this structured phase the additional particulate components in any convenient order and by mixing, e.g., agitating, the resulting component combination to form the phase stable compositions herein. In a typical process for preparing compositions, essential and certain preferred optional components will be combined in a particular order and under certain conditions.

In a first step of a preferred preparation process, an anionic surfactant- containing powder used to form a structured, surfactant-containing liquid phase is prepared. This pre-preparation step involves the formation of an aqueous slurry containing from about 30% to 60% of one or more alkali metal salts of linear C I Q. 6 alkyl benzene sulfonic acid and from about 2% to 10% of one or more diluent non-surfactant salts. In a subsequent step, this slurry is dried to the extent necessary to form a solid material containing less than about 4% by weight of residual water.

After preparation of this solid anionic surfactant-containing material, this material can be combined with one or more of the non-aqueous organic diluents to form a structured, surfactant-containing liquid phase of the cleaning compositions herein. This is done by reducing the anionic surfactant-containing material formed in the previously described pre-preparation step to powdered form and by combining such powdered material with an agitated liquid medium comprising one or more of the non-aqueous organic diluents, either surfactant or non-surfactant or both, as hereinbefore described. This combination is carried out under agitation conditions which are sufficient to form a thoroughly mixed dispersion of particles of the insoluble fraction of the co-dried LAS/salt material throughout a non-aqueous organic liquid diluent.

In a subsequent processing step, the non-aqueous liquid dispersion so prepared can then be subjected to milling or high shear agitation under conditions which are sufficient to provide a structured, surfactant-containing liquid phase of the detergent compositions herein. Such milling or high shear agitation conditions will generally include maintenance of a temperature between about 10°C and 90°C, preferably between about 20°C and 60°C; and a processing time that is sufficient to form a

network of aggregated small particles of the insoluble fraction of the anionic surfactant-containing powdered material. Suitable equipment for this purpose includes: stirred ball mills, co-ball mills (Fryma), colloid mills, high pressure honogenizers, high shear mixers, and the like. The colloid mill and high shear mixers are preferred for their high throughput and low capital and maintenance costs. The small particles produced in such equipment will generally range in size from about 0.4 to 2 microns. Milling and high shear agitation of the liquid/solids combination will generally provide an increase in the yield value of the structured liquid phase to within the range of from about 1 Pa to 8 Pa, preferably from about 1 Pa to 4 Pa.

After formation of the dispersion of LAS/salt co-dried material in the non¬ aqueous liquid, either before or after such dispersion is milled or agitated to increase its yield value, any optionally added particulate material to be used in the cleaning compositions herein can be added. Such components which can be added under high shear agitation include any optional surfactant particles, particles of substantially all of an organic builder, e.g., citrate and/or fatty acid, and/or an alkalinity source, e.g., sodium carbonate, can be added while continuing to maintain this admixture of composition components under shear agitation. Agitation of the mixture is continued, and if necessary, can be increased at this point to form a uniform dispersion of insoluble solid phase particulates within the liquid phase.

After some or all of the foregoing solid materials have been added to this agitated mixture, the particles of the peroxygen bleaching agent with coated bleach activator particles can be added to the composition, again while the mixture is maintained under shear agitation. By adding the peroxygen bleaching agent material and coated activator particles last, or after all or most of the other components, and especially after alkalinity source particles, have been added, desirable stability benefits for the peroxygen bleach can be realized. If enzyme prills are incorporated, they are preferably added to the non-aqueous liquid matrix last.

As a final process step, after addition of all ofthe particulate material, agitation of the mixture is continued for a period of time sufficient to form compositions having the requisite viscosity, yield value and phase stability characteristics. Frequently this will involve agitation for a period of from about 1 to 30 minutes.

In adding solid components to non-aqueous liquids in accordance with the foregoing procedure, it is advantageous to maintain the free, unbound moisture content of these solid materials below certain limits. Free moisture in such solid materials is frequently present at levels of 0.8% or greater. By reducing free moisture content, e.g., by fluid bed drying, of solid particulate materials to a free

moisture level of 0.5% or lower prior to their incorporation into the cleaning composition matrix, significant stability advantages for the resulting composition can be realized.

The compositions of this invention, prepared as hereinbefore described, can be used to form aqueous washing and/or bleaching solutions for use in the laundering and bleaching of fabrics. Generally, an effective amount of such compositions is added to water, preferably in a conventional fabric laundering automatic washing machine, to form such aqueous laundering/bleaching solutions. The aqueous washing/bleaching solution so formed is then contacted, preferably under agitation, with the fabrics to be laundered and bleached therewith.

An effective amount of the liquid cleaning compositions herein added to water to form aqueous laundering/bleaching solutions can comprise amounts sufficient to form from about 500 to 7,000 ppm of composition in aqueous solution. More preferably, from about 800 to 3,000 ppm of the detergent compositions herein will be provided in aqueous washing/bleaching solution.

The following examples illustrate the preparation and performance advantages of non-aqueous liquid cleaning compositions of the instant invention. Such examples, however, are not necessarily meant to limit or otherwise define the scope of he invention herein.

EXAMPLE I

Preparation of Citrate-Coated Bleach Activator Particles

Citrate coated powdered sodium nonanoyloxybenzene sulfonate (NOBS) is produced by discretely coating NOBS powder (p.s. 3-100 microns) using a Wurster fluid bed coating apparatus (Wurster HS 18" bottom spray coating unit). NOBS powder is charged to the fluid bed coating apparatus. The fluidizing air is actuated to fluidize the NOBS powder within the Wurster apparatus. Thereafter, a solution of sodium citrate dihydrate (40% by weight) is applied to the NOBS powder through a two-fluid nozzle as it recirculates in the fluidized bed. Once the target level of coating is applied, the nozzle is switched off and the product is dried in the fluidized bed for 5 minutes. Eight batches of 54.5 kg. (120 lb.) each are produced and used in the preparation of a non-aqueous liquid detergent product as hereinafter described in Example III.

EXAMPLE II

Preparation of LAS Powder

Sodium C12 linear alkyl benzene sulfonate (NaLAS) is processed into a powder containing two phases. One of these phases is soluble in the non-aqueous liquid phase of the detergent composition hereinafter described in Example III and the other phase is insoluble. It is the insoluble fraction which serves to add structure and particle suspending capability to the non-aqueous phase of the Example III composition.

NaLAS powder is produced by taking a slurry of NaLAS in water (approximately 40-50% active) combined with dissolved sodium sulfate (3-15%) and a hydrotrope, sodium sulfosuccinate (1-3%). The hydrotrope and sulfate are used to improve the characteristics of the dry powder. A drum dryer is used to dry the slurry into a flake. When the NaLAS is dried with the sodium sulfate, two distinct phases are created within the flake. The insoluble phase creates a network structure of aggregate small particles (0.4-2 um) which allows the finished non¬ aqueous detergent product to stably suspend solids.

The NaLAS powder prepared according to this example has the following makeup shown in Table I.

TABLE I

LAS Powder

Component Wt. %

NaLAS 85%

Sulfate 1 1%

Sulfosuccinate 2%

Water 2.5%

Unreacted, etc. balance to 100%

% insoluble LAS 17%

# of phase (via X-ray diffraction) 2

EXAMPLE III

Preparation of Non-Aqueous Liquid Detergent Composition

1) Butoxy-propoxy-propanol (BPP) and a Cu-,i5EO(5) ethoxylated alcohol nonionic surfactant (Neodol 1-5) are mixed for a short time (1-2 minutes) using a pitched blade turbine impeller in a mix tank into a single phase.

2) NaLAS powder as prepared in Example II is added to the BPP/Neodol solution in the mix tank to partially dissolve the NaLAS. Mix time is approximately one hour. The tank is blanketed with nitrogen to prevent moisture pickup from the air. The soluble phase of NaLAS powder dissolves, while the insoluble NaLAS aggregates and forms a network structure within the BPP/Neodol solution.

3) Liquid base (LAS/BPP/NI) is pumped out into drums. Molecular sieves (type 3 A, 4-8 mesh) are added to each drum at 10% of the net weight of the liquid base. The molecular sieves are mixed into the liquid base using both single blade turbine mixers and drum rolling techniques. The mixing is done under nitrogen blanket to prevent moisture pickup from the air. Total mix time is 2 hours, after which 0.1-0.4% ofthe moisture in the liquid base is removed.

4) Molecular sieves are removed by passing the liquid base through a 20-30 mesh screen. Liquid base is returned to the mix tank.

5) Additional solid ingredients are prepared for addition to the composition. Such solid ingredients include the following:

Sodium carbonate (particle size 10-40 microns)

Sodium citrate dihydrate

Maleic-acrylic copolymer (BASF Sokalan CP5 moisture content 4.1-5.0%)

Brightener

Diethyl triamine pentaacetic acid (DTPA)

Titanium dioxide particles (1-5 microns)

These solid materials, which are all millable, are added to the mix tank through a 20-30 mesh screen and mixed with the liquid base until smooth. This approximately 1 hour after addition of the last powder. The tank is blanketed with nitrogen after addition ofthe powders. No particular order of addition for these powders is critical.

6) The batch is pumped once through a Fryma colloid mill, which is a simple rotor-stator configuration in which a high-speed rotor spins inside a stator which creates a zone of high shear. This serves to disperse the insoluble NaLAS aggregates and partially reduce the particle size of all of the solids. This leads to an increase in yield value (i.e. structure). The batch is then recharged to the mix tank.

7) Still additional solid materials which should not be milled or subjected to high shear agitation are then prepared. These include the following/

Sodium nonanoyloxybenzene sulfonate (NOBS) coated with

Sodium citrate dihydrate as prepared in Example I. Such material is

NOBS 60%

Citrate 40%

Sodium perborate (20-40 microns)

Protease and amylase enzyme prills ( 100- 1000 microns)

These non-millable solid materials are then added to the mix tank followed by liquid ingredients (perfume and silicone-based suds suppressor). The batch is then mixed for one hour (under nitrogen blanket). The resulting composition has the formula set forth in Table II.

TABLE II Non-Aqueous Liquid Detergent Composition with Bleach

Component Wt % Active

LAS Powder 20.26

C12-14E0=5 alcohol ethoxylate 18.82

BPP 18.82

Sodium citrate dihydrate 4.32

Citrate Coated NOBS 8.49

Sodium Carbonate 11.58

Maleic-acrylic copolymer 11.58

DTPA 0.77

Protease Prills 0.77 Amylase Prills 0.39 Sodium Perborate 2.86 Suds Suppressor 0.03 Perfume 0.46

Titanium Dioxide 0.54 Brightener 0.31 100.00%

The resulting Table II composition is a stable, anhydrous heavy-duty liquid laundry detergent which provides excellent stain and soil removal performance when used in normal fabric laundering operations.

EXAMPLE IV Non-aqueous Liquid Detergents with Coated Bleach Activators

Several non-aqueous liquid detergent compositions are prepared containing sodium perborate bleach and sodium nonanoyloxybenzene sulfonate (NOBS) bleach activator. Comparative formulas use uncoated NOBS powder. Similar formulas are then prepared wherein the NOBS is coated in accordance with this invention with sodium citrate or sodium sulfate. The formulas so prepared are then evaluated for percent of peracid retained after two weeks of aging at 100°F (38°C).

Formulas and test results are set forth in Table III.

TABLE III

Formula No. fWt. %) Component A B C D E F

NOBS Form uncoated citrate sulfate uncoated citrate sulfate powder coated coated powder coated coated

C ₁₂ -1 ₅ AE3S 22.9 21.8 21.9

^C I2-14 ^AS 28.5 28.1 27.5

C12 Glucose 10.0 9.5 9.6 Amide

1 ,2-Propandiol 31.6 31.2 30.6

C12-13 E05 21.4 20.5 20.5 17.1 16.9 16.5

BPP 24.3 23.2 23.3

Sodium 14.3 13.6 13.7 9.0 8.8 8.7 Carbonate

NOBS powder 7.1 5.6

Coated NOBS 6.8 6.8 5.6 5.4

Sodium Citrate 2.9 2.3 (as coating)

Sodium Sulfate 2.7 2.2 (as coating)

NOBS particle 1.6 1.4 1.4 1.1 material

Sodium Citrate 4.3 1.9 4.3

Sodium 3.2 3.1 3.1 Perborate

DTPA 0.4 0.4 0.4

Brightener 03 03 03

100% 100% 100% 100% 100% 100%

% Peracid 0% 65% 52% 0% 20% 20% retained after 2 wks. at 100°F.

The Table III data illustrate the importance of bleach activator coating in terms of retention of activator effectiveness upon product storage.

EXAMPLE V

Non-Aqueous Liquid Detergents with Small Coated Activator Particles

Two additional non-aqueous liquid detergents are prepared containing a peroxygen bleaching agent and a sodium nonanoyloxybenzene sulfonate (NOBS) bleach activator. One product uses uncoated NOBS powder (3-100 microns), the other product uses a sodium citrate-coated NOBS powder (20-150 microns).

The products prepared are evaluated for percent of peracid retained after four weeks of aging at 100°F (38°C). These products are also observed and evaluated for rheology changes, i.e, thickening, upon storage. Product formulas and tests results are set forth in Table IV.

TABLE IV

Formula No. (Wt. %)

Component A B

NaLAS 22.0 22.0

Neodol 1-5 22.0 22.0

Butoxy-propoxy propanol 18.8 18.8

Sodium Citrate dihydrate 5.8 5.8

Sodium Carbonate 17.3 17.3

DTPA 0.8 0.8

Brightener 0.5 0.5

Sodium Percarbonate 5.2 5.2 (Degussa Q20)

NOBS powder* 7.6 0

Coated NOBS powder 0 12.7 100% 100%

Percent Peracid Retained at 4 78% 90% weeks of 100%

Rheology Solid after 4 Liquid after 4 weeks at 100°F weeks at 100°F or 8 weeks at 80°F

* The coated NOBS powder is 40% active NOBS, 60% sodium citrate. Therefore, dosing it at 12.7% results in 7.6% active NOBS.

The Table IV data indicate that the use of small particle, citrate-coated NOBS can provide both bleach stability and physical stability benefits in non-aqueous liquid detergent products.