WO1996010072A1

WO1996010072A1 - Process for preparing non-aqueous, bleach-containing liquid detergent compositions

Info

Publication number: WO1996010072A1
Application number: PCT/US1995/011238
Authority: WO
Inventors: Josephine Ling Kong-Chan; Kathleen Brenner Hunter
Original assignee: The Procter & Gamble Company
Priority date: 1994-09-26
Filing date: 1995-09-08
Publication date: 1996-04-04
Also published as: CA2199816A1; JPH10506930A; PE18896A1; EP0784669A1; TW311932B; AU3584195A; TR199501168A2

Abstract

Disclosed is a process for preparing non-aqueous, bleach-containing liquid laundry detergent compositions, which are in the form of a suspension of particulate material, including peroxygen bleaching agent and an alkyl sulfate anionic surfactant, dispersed in a liquid phase containing an alcohol ethoxylate nonionic surfactant and a non-aqueous, low-polarity organic solvent. Such a process provides compositions that exhibit especially desirable cleaning and bleaching of fabrics laundered therewith and also exhibit especially desirable chemical and phase stability.

Description

PROCESS FOR PREPARING

NON-AQUEOUS, BLEACH-CONTAINING

LIQUID DETERGENT COMPOSITIONS

FIELD OF THE INVENTION

This invention relates to the preparation of heavy duty liquid (HDL) laundry detergent products which are nonaqueous in nature and which contain a bleaching system based on peroxygen bleaching agents.

BACKGROUND OF THE INVENTION

Liquid detergent products are often considered to be more convenient to use than are dry powdered or particulate detergent products. Liquid detergents 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 detergents 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 products.

Although liquid detergents have a number of advantages over granular detergent products, they also inherently possess several disadvantages. In particular, detergent 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 detergent products which have an acceptable degree of chemical stability.

One approach for enhancing the chemical compatibility of detergent composition components in liquid detergent products has been to formulate nonaqueous (or anhydrous) liquid detergent compositions. In such nonaqueous products, at least some of the normally solid detergent 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 11, 1992 and Sanderson et al., EP-A-565,017, Published October 13, 1993.

Even though chemical compatibility of components may be enhanced in nonaqueous liquid detergent compositions, there can still occur during the preparation of such products and thereafter some undesirable chemical interactions among the composition components. This is especially true when impurities such as water or metals, both of which, for example, tend to deactivate peroxygen bleaching agents, are inevitably introduced into the composition in minor amounts along with the desired essential composition components.

In preparing non-aqueous, bleach-containing liquid detergents in the form of dispersions of particulate materials in a liquid matrix, the physical stability of such compositions may also become a problem. This is because there is a tendency for such products to phase separate as dispersed insoluble solid particulate material drops from suspension and settles at the bottom of the container holding the liquid detergent product. As one consequence of this type of problem, there can also be difficulties associated with incorporating enough of the right types and amounts of surfactant materials into nonaqueous liquid detergent products. Surfactant materials must, of course, be selected such that they are suitable for imparting acceptable fabric cleaning performance to such compositions but utilization of such surfactant materials must not lead to an unacceptable degree of composition phase separation. Accordingly, the process used to prepare non-aqueous liquid detergents containing suitable types of surfactants and peroxygen bleaching agents must be selected so as to minimize undesirable component chemical interaction and to maximize the phase stability of the product so prepared.

Given the foregoing, there is clearly a continuing need to provide processes for preparing liquid, bleach-containing detergent compositions in the form of nonaqueous liquid products that have a high degree of chemical, e.g., bleach and enzyme, stability along with commercially acceptable phase stability and detergent composition cleaning/ bleaching performance. Accordingly, it is an object of the present invention to provide a preparation process for nonaqueous, bleach- containing liquid detergent products which have such especially desirable chemical and physical stability characteristics as well as outstanding fabric laundering/bleaching performance characteristics.

SUMMARY OF THE INVENTION The present invention provides a process for preparing physically and chemically stable, nonaqueous liquid detergent compositions containing particles of peroxygen bleaching agents suspended therein. Such a process comprises the steps of:

A) forming an agitated nonaqueous liquid matrix which is a combination of a certain type of liquid nonionic surfactant and a nonaqueous, low-polarity organic solvent component;

B) thereafter adding to this agitated nonaqueous liquid matrix particulate material which comprises a certain type of anionic surfactant and a certain type of desiccant/alkalinity source;

C) thereafter continuing agitation of this nonaqueous liquid matrix to uniformly disperse in the matrix all of the particulate material added in Step B);

D) thereafter adding to the Step C) agitated nonaqueous liquid matrix particles of a peroxygen bleaching agent; and

E) thereafter continuing agitation of the Step D) nonaqueous liquid matrix to form the desired detergent compositions in the form of a uniform dispersion of particulate materials in nonaqueous liquid, wherein this dispersion has a viscosity ranging from about 300 to 5,000 cps.

The essentially utilized liquid nonionic surfactant is an alcohol ethoxylate of the formula R*'(OC2H4)_nOH wherein R* is a C - Cig alkyl group and n is from about 1 to 80. In Step A) this nonionic surfactant is used in at least 51% of an amount sufficient to provide from about 1% to 60% by weight of this nonionic surfactant component in the detergent composition which is ultimately prepared.

The other component used to form the Step A) nonaqueous liquid matrix is a nonaqueous, low-polarity organic solvent. Such a solvent is utilized in at least 51% of an amount which is sufficient to provide from about 1% to 60% by weight of this nonaqueous, low-polarity solvent in the detergent composition which is ultimately prepared. The particulate material added in Step B) is one which is substantially insoluble in the nonaqueous liquid matrix to which it is added. Such particulate material ranges in particle size from about 0.2 to 1,000 microns. The particulate material added in Step B) must include an anionic surfactant material comprising sulfated Cg - C20 alcohols. This anionic surfactant material is added in an amount sufficient to provide from about 10% to 40% by weight of this anionic surfactant material in the detergent composition which is ultimately prepared.

The particulate material added in Step B) must also include a desiccant/alkalinity source which is selected from hydratable, water-soluble alkali metal carbonates, bicarbonates, borates, silicates and metasilicates. This desiccant/alkalinity source is added in an amount sufficient to provide from about 5% to 20% by weight of this desiccant/alkalinity source in the detergent composition which is ultimately prepared.

The peroxygen bleaching agent added in Step D) also comprises particulate material which ranges in size from about 0.2 to 1,000 microns. The peroxygen bleaching agent particles are added in an amount sufficient to provide from about 2% to 30% by weight of these peroxygen bleaching agent particles in the detergent composition which is ultimately prepared.

The detergent composition preparation process herein may optionally include the addition to the detergent composition being prepared of additional liquids and solid particulate materials including optional nonionic surfactants, activators for the peroxygen bleaching agent, detergent builders, detergent enzymes, chelating agents, suds supressors and the like.

DETAD ED DESCRIPTION OF THE INVENTION

The nonaqueous liquid detergent compositions prepared by the process of this invention comprise a nonionic surfactant- and low-polarity solvent-containing liquid phase having dispersed therein as a solid phase certain types of particulate materials. Compositions of this type are also disclosed in the concurrently filed U. S. patent application of Josephine L. Kong-Chan and Kathleen B. Hunter, which application has U. S. Serial No. ( P&G Case No. 5436).

The essential and optional components of the liquid and solid phases of the detergent compositions which are prepared by the process herein are described in greater detail as follows: All concentrations and ratios are on a weight basis unless otherwise specified. STEP A. LIQUID MATRIX FORMATION

The liquid matrix formed in the first step of the detergent composition preparation process herein essentially contains certain types of nonionic surfactants and certain types of nonaqueous, low-polarity solvents.

(1) Nonionic Surfactant

The liquid matrix formed in the detergent composition preparation process of this invention essentially comprises an ethoxylated fatty alcohol nonionic surfactant. Such a material corresponds to the general formula:

wherein R* is a C - Cjg alkyl group and n ranges from about 1 to 80. Preferably the R! alkyl group, which may be primary or secondary, contains from about 9 to 15 carbon atoms, more preferably from about 10 to 14 carbon atoms. Preferably the ethoxylated fatty alcohol will contain from about 2 to 12 ethylene oxide moieties per molecule, more preferably from about 3 to 10 ethylene oxide moieties per molecule. The ethoxylated fatty alcohol nonionic surfactant 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 10 to 15. Examples of fatty alcohol ethoxylates useful as the essential liquid nonionic surfactant in the 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 tradenames 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 \2 - \ alcohol having about 9 moles of ethylene oxide and Neodol 91- 10, an ethoxylated Co, - C\ \ 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 tradename. 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 C12- 15 fatty alcohol with an average of 7 moles of ethylene oxide per mole of fatty alcohol.

Other examples of suitable ethoxylated alcohol nonionic surfactants 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 C15 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 ethoxylate nonionics useful in the present compositions 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 14-15 carbon atoms and the number of ethylene oxide groups per mole being about 11. Such products have also been commercially marketed by Shell Chemical Company.

The alcohol ethoxylate nonionic which is essentially utilized to form part of the liquid matrix of the process herein will generally be present to the extent of ultimately providing from about 1% to 60% by weight of this material in the detergent composition eventually prepared. More preferably, the alcohol ethoxylate nonionic will be used in an amount that provides from about 5% to 35% by weight of this component in the compositions herein. Most preferably, the essentially utilized alcohol ethoxylate nonionic will be used in amounts sufficient to provide from about 8% to 25% by weight of this component in the detergent compositions herein.

(2) Nonaqueous. Low-Polaritv Organic Solvent A second essential component of the liquid matrix formed in the irst step of the process herein comprises nonaqueous, low-polarity organic solvent(s). The term "solvent" is used herein to connote the non-surface active carrier or diluent portion of the liquid phase of the composition. While some of the essential and/or optional components of the compositions prepared herein may actually dissolve in the "solvent" -containing liquid phase, other components will be present as particulate material dispersed within the "solvent "-containing liquid phase. Thus the term "solvent" is not meant to require that the solvent material be capable of actually dissolving all of the detergent composition components added thereto.

The nonaqueous organic materials which are employed as solvents herein are those which are liquids of low polarity. For purposes of this invention, "low- polarity" liquids are those which have little, if any, tendency to dissolve the peroxygen bleach, e.g., sodium perborate, and optional bleach activators, e.g., sodium nonanoyloxybenzene sulfonate (NOBS), which are present in the nonaqueous compositions herein. Thus relatively polar solvents such as ethanol and propanediol should not be utilized. Suitable types of low-polarity solvents useful in the nonaqueous liquid detergent compositions herein do include 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 nonaqueous, low-polarity solvent for use herein comprises the mono-, di-, tri- or tetra- C₂ - C3 alkylene glycol mono C₂ - C_$ alkyl ethers. Specific examples of such compounds include diethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, dipropylene glycol monoethyl ether and dipropylene glycol monobutyl ether. Diethylene glycol monobutyl ether and dipropylene glycol monobutyl ether are especially preferred. Compounds of this type have been commercially marketed under the tradenames Dowanol, Carbitol and Cellosolve.

Another preferred type of nonaqueous, 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, nonaqueous solvent comprises lower molecular weight methyl esters. Such materials are those of the general formula: Rl-C(O)-OCH3 wherein Rl 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 nonaqueous, low-polarity organic solvent(s) employed should, of course, be compatible and non-reactive with other composition components, e.g., bleach and/or activators, used in the liquid detergent compositions herein. Such a solvent component will generally be utilized in the process herein in an amount sufficient to provide from about 1% to 60% by weight of this solvent component in the detergent composition ultimately prepared. More preferably, the nonaqueous, low-polarity organic solvent(s) will be used in an amount which provides from about.15% to 45% by weight of solvent in the final composition, most preferably from about 20% to 45% by weight of solvent in the final composition.

STEP B) SOLED MATERIAL

In the second step of the process herein (Step B), two different types of solid particulate materials are essentially added to the liquid matrix. These two essential types of materials are 1) alkyl sulfate anionic surfactant and 2) a desiccant/alkalinity source and are each described in detail as follows: (1) Essential Anionic Surfactant

One essential solid phase material added to the liquid matrix in the second process step herein comprises a primary or secondary alkyl sulfate anionic surfactant. Such surfactants are those produced by the sulfation of higher Cg - C₂rj fatty alcohols.

Conventional primary alkyl sulfate surfactants have the general formula

ROSO3-M+ wherein R is typically a linear Cg - C₂Q hydrocarbyl group, which may be straight chain or branched chain, and M is a water-solubilizing cation. Preferably R is a C\_Q - C14 alkyl, and M is alkali metal. Most preferably R is about Cι₂ and M is sodium. Conventional secondary alkyl sulfates may also be utilized as the essential 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(CH₂)_n(CHOSO₃-M⁺) (CH₂)_mCH₃ 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.

Especially preferred types of secondary alkyl sulfates are the (2,3) alkyl sulfate surfactants which can be represented by structures of formulas A and B

(A) CH₃(CH₂)_x(CHOSO3-M⁺) CH₃ and

(B) CH₃(CH₂)_y(CHOSθ3-M⁺) CH₂CH₃ for the 2-sulfate and 3-sulfate, respectively. In formulas A and B, x and (y+1) are, respectively, integers of at least about 6, and can range from about 7 to about 20, preferably about 10 to about 16. M is a cation, such as an alkali metal, alkaline earth metal, or the like. Sodium is typical for use as M to prepare the water-soluble (2,3) alkyl sulfates, but potassium, and the like, can also be used.

The alkyl sulfate surfactants essentially utilized herein do not generally dissolve in the liquid phase and will hence be dispersed throughout the liquid phase as discrete particles. Such particles will typically range in size from about 0.2 to 1,000 microns, more preferably from about 1 to 800 microns.

The requisite alkyl sulfate anionic surfactant should be used in relatively high concentrations in order to provide suitable soil/stain removal performance and in order to provide suspension phase stability for the nonaqueous detergent compositions as prepared herein. The alkyl sulfate surfactant will generally be used in amounts sufficient to provide from about 10% to 40% by weight of alkyl sulfate in the compositions prepared herein. More preferably, alkyl sulfate will be utilized to the extent needed to provide from about 16% to 30% by weight of alkyl sulfate in the composition. Frequently, alkyl sulfate surfactant will be employed in amounts sufficient to provide a liquid phase to alkyl sulfate anionic weight ratio of from about 1 : 1 to 5: 1, more preferably from about 1.5: 1 to 3.5: 1.

(2) Essential Desiccant/ Alkalinity Source

A second essential solid phase material added to the liquid matrix in the second (Step B) process step herein comprises a hydratable material which serves both as a desiccant and as material that renders generally alkaline in nature the aqueous washing solutions formed from the compositions prepared herein. 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 desiccant/alkalinity sources include hydratable, 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 hydratable alkali metal pyrophosphates, orthophosphates, polyphosphates and phosphonates. Of all of these desiccant/alkalinity sources, alkali metal carbonates, such as sodium carbonate, are the most preferred. The desiccant/alkalinity source will generally be added in an amount such that it comprises from about 5% to 30% by weight of the compositions ultimately prepared herein. More preferably, the desiccant/alkalinity source can be added in amounts sufficient to provide from about 5% to 20% by weight of this component in the ultimately prepared compositions. Such materials, while water-soluble, will generally be insoluble in the nonaqueous detergent compositions herein. Thus such materials will generally be dispersed in the nonaqueous liquid phase in the form of discrete particles.

STEP D) PEROXYGEN BLEACHING AGENT (WITH OPTIONAL BLEACH ACTIVATORS^

After addition of the alkyl sulfate and desiccant/alkalinity source particulates in Step B), the non-aqueous liquid matrix is further subjected to shear agitation in Step C) to form a uniform dispersion of this solid particulate material in the nonaqueous liquid matrix. At this point, in process Step D) particles of peroxygen bleaching agent are added. Such peroxygen bleaching agents may be organic or inorganic in nature. Inorganic peroxygen bleaching agents are frequently utilized in combination with a bleach activator. Usefiil organic peroxygen bleaching agents include percarboxylic acid bleaching agents and salts thereof. Suitable examples of this class of agents include magnesium monoperoxyphthalate hexahydrate, the magnesium salt of metachloro perbenzoic acid, 4-nonylamino-4-oxoperoxybutyric acid and diperoxydodecanedioic acid. Such bleaching agents are disclosed in U.S. Patent 4,483,781, Hartman, Issued November 20, 1984; European Patent Application EP-A-133,354, Banks et al., Published February 20, 1985; and U.S. Patent 4,412,934, Chung et al., Issued November 1, 1983. Highly preferred bleaching agents also include 6-nonylamino-6- oxoperoxycaproic acid (NAPAA) as described in U.S. Patent 4,634,551, Issued January 6, 1987 to Burns et al.

Inorganic peroxygen bleaching agents may also be used in particulate form in the preparation of the detergent compositions herein. Inorganic bleaching agents are in fact preferred. Such inorganic peroxygen compounds include alkali metal perborate and percarbonate materials. 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.

Inorganic peroxygen bleaching agents, e.g., the perborates, the percarbonates, etc., are preferably combined with bleach activators, which lead to the in situ production in aqueous solution (i.e., during use of the compositions herein for fabric laundering bleaching) of the peroxy acid corresponding to the bleach activator. 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 and preferred. Mixtures thereof can also be used. See also the hereinbefore referenced U.S. 4,634,551 for other typical bleaches and activators useful herein.

Other useful amido-derived bleach activators are those of the formulae: RlN(R⁵)C(O)R²C(O)L or R¹C(O)N(R⁵)R²C(O)L wherein R¹ is an alkyl group containing from about 6 to about 12 carbon atoms, R² 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 " ^π "

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-nonanamidocaproyl) oxybenzenesulfonate, (6-decanamido-caproyl)oxybenzenesulfonate and mixtures thereof as described in the hereinbefore referenced U.S. Patent 4,634,551.

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 of the 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- trimethylhexanoy] 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. Still another class of useful bleach activators are those which are liquid in form at room temperature and can be added as liquids to the nonaqueous liquid phase of the detergent compositions herein. One such liquid bleach activator is acetyl triethyl citrate (ATC). Other examples include glycerol triacetate and nonanoyl valerolactam. The peroxygen bleaching agent particles, and activator particles for those activators which are solids, should have an average particle size which ranges from about 0.2 to 1,000 microns, more preferably from about 1 to 800 microns. Preferably, no more than about 10% by weight of the bleaching agent and/or activator particles will be smaller than about 1 micron and no more than about 10% by weight of such particles will be larger than about 500 microns. Both peroxygen bleaching agent, and bleach activator if a solid activator is utilized, should be in the form of particles which are substantially insoluble in the nonaqueous liquid matrix being used to form the detergent compositions herein. Peroxygen bleaching agent will generally be added to the liquid matrix in amounts sufficient to provide from about 2% to 30% by weight of peroxygen bleaching in the compositions ultimately prepared. More preferably, peroxygen bleaching agent will be added in amounts sufficient to provide from about 2% to 20% by weight of peroxygen bleach agents in the compositions herein. Most preferably, peroxygen bleaching agent will be used in amounts sufficient to provide from about 3% to 15% by weight of peroxygen bleaching agents in the compositions prepared herein. If utilized, bleach activators can be added in amounts sufficient to provide from about 2% to 10% by weight of activator component in the compositions herein. 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.

OPTIONAL COMPOSITION COMPONENTS

In addition to the essential composition liquid and solid phase components as hereinbefore described, the detergent compositions prepared by the process herein can, and preferably will, contain various optional components. Such optional components may be in either liquid or solid form. The solid form optional components may either dissolve in the liquid phase or may be dispersed within the liquid phase in fine particulate form, as part of the solid phase of the composition. Except for the optional enzyme component, optional components can generally be added at any point in the process herein, either during or after formulation of the Step A) liquid matrix. Some of the materials which may optionally be utilized in preparing the compositions herein are described in greater detail as follows:

(A) Optional Surfactants

Besides the essentially utilized alcohol ethoxylates and alkyl sulfate surfactants, the detergent compositions prepared herein may also contain other types of surfactant materials, provided such additional surfactants are compatible with other composition components and do not substantially adversely affect composition stability or performance. Optional surfactants can be of the anionic, nonionic, cationic, and/or amphoteric type. If employed, optional surfactants will generally be added so that they comprise from about 1% to 20% by weight of the compositions prepared herein, more preferably from about 5% to 10% by weight of the compositions prepared herein.

One preferred type of optional nonionic surfactant comprises surfactants which are ethylene oxide (EO) - propylene oxide (PO) block polymers. Materials of this type are well known nonionic surfactants which have been marketed under the tradename 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 incoφorated herein by reference. These Pluronic type nonionic surfactants are believed to function as effective suspending agents for the particulate material which is dispersed in the liquid phase of the detergent compositions herein. One common type of anionic surfactant which is preferably not utilized in the preparation of the compositions herein comprises the sulfonated anionics which are alkyl benzene sulfonates. Such non-bleach activating sulfonated anionic surfactants, like linear alkylbenzene sulfonate (LAS), tend not to provide acceptable phase properties for the nonaqueous liquid detergent compositions prepared according to this invention. Accordingly, such compositions as prepared herein will preferably be substantially free of alkyl benzene sulfonate anionic surfactant materials.

(B) Optional Organic Detergent Builders

The detergent compositions as prepared herein may also optionally contain an organic 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 materials include the alkali metal, citrates, succinates, malonates, fatty acids, carboxymethyl succinates, 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 are organic phosphonate type sequestering agents such as those which have been sold by Monsanto under the Dequest tradename 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.

If utilized, optional organic builder materials will generally be added so that they comprise from about 1% to 60%, more preferably from about 3% to 50%, most preferably from about 3% to 20%, by weight of the compositions prepared herein.

(C) Optional Chelating Agents

The detergent compositions as prepared herein may also optionally contain a chelating agent which serves to chelate metal ions, e.g., iron and/or manganese, within the nonaqueous detergent compositions as prepared 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, amino phosphonates, polyfunctionally-substituted aromatic chelating agents and mixtures thereof.

Amino carboxylates useful as optional chelating agents include ethylenediaminetetraacetates, N-hydroxyethylethylenediaminetriacetates, nitrilotriacetates, ethylenediamine tetrapropionates, triethylenetetra- aminehexacetates, diethylenetriaminepentaacetates, ethylenediaminedisuccinates and ethanoldiglycines. 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) such as DEQUEST. Preferably, these amino phosphonates do not contain alkyl or alkenyl groups with more than about 6 carbon atoms.

Preferred chelating agents include 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 be added such that it comprises from about 0.1% to 4% by weight of the compositions prepared herein. More preferably, the chelating agent will be added so as to comprise from about 0.2% to 2% by weight of the detergent compositions prepared herein.

(D) Optional Enzymes The detergent compositions as prepared 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 nonaqueous liquid detergent compositions prepared herein in the form of suspensions, "marumes" or "prills". Since enzymes in particulate forms such as prills may be fairly fragile, enzymes, if used, should generally be added to the nonaqueous matrix last.

Enzymes added to the compositions prepared 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 nonaqueous liquid phase of the composition. Prills in the compositions prepared according to 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 as prepared herein 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 nonaqueous 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 nonaqueous liquid detergent compositions as prepared 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 Thickening. Viscosity Control and/or Dispersing Agents

The detergent compositions as prepared 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).

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 vinylmethyl ether, styrene, ethylene, etc. is suitable provided that such segments do not constitute more than about 40% by weight of the 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 added such that they are present in the compositions prepared herein to the extent of from about 0.1% to 4% by weight. More preferably, such materials can be added such that they comprise from about 0.5% to 2% by weight of the detergents compositions as prepared herein.

(F) Optional Brighteners. Suds Suppressors and/or Perfumes The detergent compositions as prepared herein may also optionally contain conventional brighteners, suds suppressors and/or perfume materials. Such brighteners, suds suppressors and perfumes must, of course, be compatible and non- reactive with the other composition components in a nonaqueous environment. If present, brighteners, suds suppressors and/or perfumes will typically be added such that they comprise from about 0.1% to 2% by weight of the compositions prepared herein. COMPOSITION FORM

As indicated, the nonaqueous liquid detergent compositions prepared herein are in the form of bleaching agent and other materials in particulate form as a solid phase suspended in and dispersed throughout a nonaqueous liquid phase. Generally, the nonaqueous liquid phase will comprise from about 30% to 70% by weight of the composition with the dispersed solid phase comprising from about 30% to 70% by weight of the composition. Generally, size of the solid, insoluble particulate material (other than enzyme prills) dispersed in the liquid phase will range from about 0.2 to 1,000 microns, more preferably from about 1 to 800 microns. The bleach-containing liquid detergent compositions prepared in accordance with this invention are substantially nonaqueous (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 prepared herein. More preferably, water content of the nonaqueous detergent compositions prepared herein will comprise less than about 2% by weight.

The bleach-containing nonaqueous liquid detergent compositions as prepared herein will be relatively viscous and phase stable under conditions of commercial marketing and use of such compositions. Generally viscosity of the compositions prepared 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 Brookfield Viscometer using a RV #5 spindle at 50 rpm.

PROCESSING CONDITIONS AND ALTERNATIVES As noted hereinbefore, in the preparation process of this invention, a liquid matrix is formed containing at least a major proportion, e.g., at least 51%, preferably at least 75%, and more preferably substantially all, of the liquid components, e.g., the essential alcohol ethoxylate nonionic surfactant and the nonaqueous, low-polarity organic solvent, with the liquid components being thoroughly admixed by imparting shear agitation to this liquid combination. For example, rapid stirring with a mechanical stirrer may be usefully employed.

While shear agitation is maintained, essentially all of the alkyl sulfate anionic surfactant, e.g., sodium lauryl sulfate, can be added in the form of particles ranging in size from about 0.2 to 1,000 microns. Either before or after addition of the alkyl sulfate particles, particles of substantially all of the desiccant/alkalinity source, e.g., sodium carbonate, can be added while continuing to maintain this admixture of composition components under shear agitation. Other solid form optional ingredients, except for the optional enzyme component, can be added to the composition at this point. 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. At this point, the particles of the requisite peroxygen bleaching agent can be added to the liquid matrix, again while the mixture is maintained under shear agitation. By adding the peroxygen bleaching agent material last, or after all or most of the other components, but especially after the alkyl sulfate and desiccant/alkalinity source particles, have been added, desirable stability benefits for the peroxygen bleach in the compositions prepared herein can be realized.

After addition of the bleaching agent particles, agitation of the mixture is continued for a period of time sufficient to form compositions having the requisite viscosity and phase stability characteristics. Frequently this will involve agitation for a period of from about 30 to 60 minutes. During this period of final agitation, the optional enzyme material, e. g., prills, may be added if desired.

In one variation of the composition preparation procedure hereinbefore described, one or more of the solid components may be added to the agitated mixture as a slurry of particles premixed with a minor portion of one or more of the liquid components. Thus a premix of a small fraction of the nonionic surfactant and/or nonaqueous, low-polarity solvent with particles of the alkyl sulfate surfactant and/or the particles of the alkalinity source and/or particles of a bleach activator may be separately formed and added as a slurry to the agitated mixture of composition components. Addition of such slurry premixes should, however, precede addition of peroxygen bleaching agent particles which may themselves be part of a premix slurry formed in analogous fashion.

COMPOSITION USE

The compositions prepared in accordance with this invention can be used to form aqueous washing 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 detergent 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 1,000 to 3,000 ppm of the detergent compositions herein will be provided in aqueous washing/bleaching solution.

EXAMPLE

The following example illustrates the detergent composition preparation process of the present invention but is not necessarily meant to limit or otherwise define the scope of the invention herein.

EXAMPLE I

A detergent composition is prepared by mixing together the ingredients listed in Table I in the proportions shown. These steps in the preparation process are described in detail folio winf Table I:

Table I

Component Wt. % G Function Form

Neodol 1-5* 14.4 71.9 Liquid Nonionic Liquid Surfactant

Dipropylene glycol 29.6 147.8 Low Polarity Organic Liquid monobutyl ether Solvent

Pluronic 10R5** 9.6 47.9 Optional Nonionic/ Liquid Suspension Aid

Sodium Lauryl Sulfate 20 99.8 Anionic Surfactant 0.2-150μ Particles

Sodium Citrate Dihydrate 4 20 Detergent Builder 0.2-300μ Particles

Diethylenetriamine- 1.6 8 Chelant 5-300μ Particles pentaacetic Acid (DTPA)

Tinopal AMS-BX*** 0.3 1.6 FWA 5-200μ Particles

Sodium Carbonate 12 59.9 Alkalinity Source 0.2-150μ Particles

Sodium Nonyloxybenzene- 5.3 26.4 Bleach Activator 0.2-150μ Particles sulfonate

Sodium Perborate 3 14.8 Hydrogen Peroxide 50-350μ Particles

Monohydrate Source

Protease prills (Blue) 0.4 2 Enzvme 300-800U Prills

Total 100 500

*C11 ethoxylated alcohol with 5 moles of ethylene oxide per mole of alcohol, from Shell Chemical Company. **Polyoxypropylene-polyoxyethylene Block Copolymer from BASF Corporation.

•••Fluorescent Whitening Agent from Ciba-Geigy Corporation.

Into a 1 -liter vessel are charged all the liquid ingredients (alcohol ethoxylates, organic solvent, Pluronic). The mixture is thoroughly mixed with a mechanical mixer (Lightnin mixer) operated at 350 rpm. With agitation continuing, the sodium citrate, DTPA and FWA particles are added next. The resulting mixture is then further processed by subjecting it to high shear dispersing in a Ultra-Turrax T50, π A-Labortechnik disperser operated at 3,000 min"*. The mixture is then returned to the Lightnin mixer and, with agitation at 500 rpm, the sodium lauryl sulfate is added. With continuous agitation, the sodium carbonate is added next, followed by the powdered bleach activator. The mixture is thoroughly mixed until all solid particles are wetted and nicely dispersed in the liquid matrix. The sodium perborate monohydrate is then added. Finally, protease prills are then added last with mixing continuing at 800 rpm.

The finished product is an opaque, white, creamy liquid with suspended solids. The blue enzyme prills are visible and give the product a speckled appearance. The viscosity is 620 cps when measured on a Brookfield RV viscometer with a RV #5 spindle at 50 rpm. After 1 week at ambient temperature, the viscosity of the product reaches 1000 cps and remains relatively constant afterwards. Approximately 5% separation (clear phase on top layer) is observed after 3 days at ambient temperature. The separated phases are dispersed readily, and the dispensing properties of the product are good. Chemical stability of this product is excellent. After 4 weeks at 100°F, >85% of the original Available Oxygen is still retained.

Claims

WHAT IS CLAIMED IS:

1. A process for preparing a physically and chemically stable non-aqueous liquid detergent composition containing particles of peroxygen bleaching agent suspended therein, which process is characterized in that it comprises the steps of:

A) forming an agitated, nonaqueous liquid matrix comprising a combination of i) one or more liquid alcohol ethoxylate nonionic surfactant(s) of the formula R¹(OC2H4)_nOH wherein R¹ is a CQ - C- Q alkyl group and n is from 1 to 80; said nonionic surfactant(s) being utilized in at least 51% of an amount sufficient to provide from 1 % to 60% , preferably 5% to 35% by weight of said nonionic surfactant(s) in the detergent composition which is ultimately prepared, and ii) one or more nonaqueous, low-polarity organic solvent(s), said solvent(s) being utilized in at least 51% of an amount sufficient to provide from 1% to 60%, preferably 15% to 45% by weight of said nonaqueous, low-polarity solvent(s) in the detergent composition which is ultimately prepared; and thereafter;

B) adding to the agitated, nonaqueous liquid matrix of Step A) particulate material which is substantially insoluble in said nonaqueous liquid matrix, which is of particle size ranging from 0.2 to 1 ,000 microns and which comprises both i) anionic surfactant material comprising sulfated Cβ to C20 alcohols, said anionic surfactant material being added in an amount sufficient to provide from 10% to 40%, preferably 16% to 30%, by weight of said anionic surfactant material in the detergent composition which is ultimately prepared; and ii) a desiccant/alkalinity source selected from hydratable, water- soluble alkali material carbonates, preferably sodium carbonate; bicarbonates; borates; silicates and metasilicates, said desiccant/alkalinity source being added in an amount sufficient to provide from 5% to 30% by weight of said desiccant/alkalinity source in the detergent composition which is ultimately prepared; and thereafter C) continuing agitation of said nonaqueous liquid matrix until all of the particulate material added in Step B) is substantially uniformly dispersed in said nonaqueous liquid matrix; and thereafter

D) adding to the agitated nonaqueous liquid matrix of Step C) particles of peroxygen bleaching agent, wherein said peroxygen bleaching agent particles range in size from 0 2 to 1 ,000 microns, preferably 1 to 800 microns, and are used in an amount sufficient to provide from 2% to 30%, preferably 2% to 20%, by weight of said peroxygen bleaching agent particles in the detergent composition which is ultimately prepared, and thereafter

E) continuing agitation of the nonaqueous liquid matrix of Step D) to provide said detergent composition in the form of a uniform dispersion of particles within a nonaqueous liquid, which dispersion has a viscosity ranging from 300 to 5,000 cps

A process according to Claim 1 wherein a) the nonionic surfactant used in Step A) comprises matenals selected from ethoxylates containing from 9 to 15 carbon atoms and having from 2 to 12 ethylene oxide moieties per molecule; b) the nonaqueous, low-polarity organic solvent used in Step B) is selected from i) mono, di, tn, and tetra C2 - C3 alkylene glycol mono C2 - OQ alkyl ethers; ii) polyethylene glycols ranging in molecular weight of from 200 to

600; and iii) methyl esters of the formula R¹-C(O)-OCH3 wherein R¹ is an alkyl group containing from 1 to 18 carbon atoms; c) said anionic surfactant materials added in Step B) compnses materials selected from C-JQ - C14 primary alkyl sulfates; and d) said peroxygen bleaching agent added in Step D) is selected from percarboxylic acids and salts thereof and alkali metal perborates and percarbonates.

A process according to Claim 1 or Claim 2 wherein a) said Step D) peroxygen bleaching agent is selected from alkali metal perborates and percarbonates; and b) said process further comprises the step of adding at any point after Step A) particles of a bleach activator which can react with said peroxygen bleaching agent to form a peroxy acid, said bleach activator particles ranging in size from 0.2 to 1 ,000 microns and said bleach activator particles being added in an amount sufficient to provide from 2% to 10% by weight of said activator particles in the ultimately prepared composition.

4. A process according to any of Claims 1 to 3 which further comprises the step of adding at any point during or after Step A) an additional nonionic surfactant comprising ethylene oxide-propylene oxide block polymers, said additional nonionic surfactant being added in an amount sufficient to provide from 1% to 20% by weight of said additional nonionic surfactant in the detergent composition which is ultimately prepared.

5. A process according to any of Claims 1 to 4 which further comprises the step of adding at any point after Step A) an organic detergent builder selected from alkali metal citrates, preferably sodium citrate; succinates; malonates; carboxymethylsuccina.es; carboxylates; polycarboxylates and polyacetylcarboxylates, said organic detergent builder being added in an amount sufficient to provide from 1% to 60% by weight of said builder in the detergent composition which is ultimately prepared.

6. A process according to any of Claims 1 to 5 which further comprises the step of adding at any point after Step A) a chelating agent selected from amino carboxylates, amino phosphonates, polyfunctional substituted aromatic chelating agents and combinations of these chelating agents, said chelating agent being added in an amount sufficient to provide from 0.1% to 4% by weight of said chelating agent in the detergent composition which is ultimately prepared.

7. A process according to Claim 6 wherein said chelating agent is selected from diethylene triamine pentaacetic acid, ethylene diamine disuccinic acid and dipicolinic acid and the salts of these chelating agents.

8. A process according to any of Claims 1 to 7 which further comprises the step of adding during Step E) enzyme prills wherein said prills range in size from 100 to 1,000 microns, wherein said enzyme is selected from proteases, amylases, cellulases and lipases, and wherein said prills are added in an amount sufficient to provide from 0.001% to 5% by weight of said prills in the detergent composition which is ultimately prepared.

9. A process according to any of Claims 1 to 8 which further comprises the step of adding at any point after Step A) i) a thickening, viscosity control and/or dispersing agent selected from acrylic acid-based polymers having a molecular weight ranging from 2,000 to 10,000, said thickening, viscosity control and/or dispersing agent being added in an amount sufficient to provide from 0.1% to 4% by weight of said agent in the detergent composition which is ultimately prepared; and/or ii) a compatible brightener, suds suppressor and/or perfume, added in an amount sufficient to provide from 0.1% to 2% by weight of said brightener, suds suppressor and/or perfume in the detergent composition which is ultimately prepared.

10. A process for preparing a physically and chemically stable, nonaqueous liquid detergent composition containing particles of peroxygen bleaching agent suspended therein, which process is characterized in that it comprises the steps of:

(I) forming an agitated, nonaqueous liquid matrix comprising a combination of a) one or more ethoxylated alcohol liquid nonionic surfactants which contain from 10 to 14 carbon atoms and from 3 to 10 moles of ethylene oxide, said nonionic surfactant(s) being utilized in at least 51% of an amount sufficient to provide from 8% to 25% by weight of said nonionic surfactant(s) in the detergent composition which is ultimately prepared. b) one or more nonaqueous, low-polarity organic solvents selected from diethylene glycol monobutyl ether and dipropylene glycol monobutyl ether, said solvent(s) being utilized in at least 51% of an amount sufficient to provide from 20% to 45% by weight of said nonaqueous, low-polarity solvent(s) in the detergent composition which is ultimately prepared; and thereafter;

(II) adding to the agitated nonaqueous liquid matrix of Step (I) particulate material which is substantially insoluble in said nonaqueous liquid matrix, which is of particle size ranging from 1 to 800 microns and which comprises a) C-]Q to C-_]4 alkyl sulfate anionic surfactant added in an amount sufficient to provide from 16% to 30% by weight of said anionic surfactant in the detergent composition which is ultimately prepared; and b) a sodium carbonate desiccant/alkalinity source added in an amount sufficient to provide from 5% to 20% by weight of said desiccant/alkalinity source in the detergent composition which is ultimately prepared; and c) a peroxygen bleaching agent selected from sodium and potassium perborates and percarbonates, said peroxygen bleaching agent being added in an amount sufficient to provide from 3% to 15% by weight of such peroxygen bleaching agent in the detergent composition which is ultimately prepared; and d) a bleach activator selected from nonanoyloxybenzene sulfonate and tetraacetyl ethylene diamine, said bleach activator being added in an amount sufficient to provide from 2% to 10% by weight of said bleach activator in the detergent composition which is ultimately prepared; with the provision that the particles of said peroxygen bleaching agent are added to said agitated nonaqueous liquid matrix after the particles of said sodium carbonate desiccant/alkalinity source have been added and thoroughly dispersed within said nonaqueous liquid matrix; and thereafter

(III) continuing agitation of the nonaqueous liquid matrix of Step (II) to provide said detergent composition in the form of a uniform dispersion of particles within a nonaqueous liquid, which dispersion has a viscosity ranging from 500 to 3,000 cps.; and thereafter

(IV) dispersing within the agitated nonaqueous liquid matrix of Step (III) enzyme prills comprising an enzyme selected from proteases, amylases, cellulases and lipases, with said enzyme prills being added in an amount sufficient to provide from 0.01% to 1% by weight of said enzyme prills in the detergent composition which is ultimately prepared.

11. A process according to any of Claims 1 to 10 wherein the composition prepared thereby has from 30% to 70% by weight of the composition of a liquid phase and from 30% to 70% by weight of the composition of a solid particulate phase.

12. A process according to any of Claims 1 to 11 wherein one or more of the particulate components is added to said agitated nonaqueous liquid matrix in the form of a premixed slurry formed by combining said particulate component with a minor fraction of one or more of said nonionic surfactant and/or nonaqueous, low- polarity solvent components.