AU6623600A - Granular detergent compositions having surfactant particle with reduced electrolyte concentrations - Google Patents

Description

WO 01/11005 PCT/US00/21484 GRANULAR DETERGENT COMPOSITIONS HAVING SURFACTANT PARTICLE WITH REDUCED ELECTROLYTE CONCENTRATIONS Technical Field The present invention relates to granular detergent compositions having surfactant particles with reduced electrolyte concentrations, and in particular to detergent compositions with surfactant particles of reduced carbonate levels. Background of the Invention In recent years, the popularity of liquid detergent compositions has been on the rise. This growing popularity is due in large part to superiority in dispersion and dissolution of liquid detergents in comparison to their granular counterparts. These dissolution and dispersion advantages are particularly apparent in cold water conditions, i.e. less than 30'C where traditionally, the dissolution of granular detergents has been lacking. Despite the advantages of liquid detergent compositions, granular products retain numerous advantages. These advantages include performance, formulation capability, lower-cost packaging and higher product stability. The advantages of product stability and formulation capability are derived in large part from the nature of granular admixtures where components can be individually stabilized and isolated into particles before being admixed with other particles. This physical separation in the final detergent composition allows the use of materials that are potentially unstable in a composition such as bleaches, enzymes, etc. In general, performance of granular detergent compositions depends on depends on both dispersion of the granules in the wash water and the dissolution of the individual granules. In general, there is an optimal balance between the two properties. Particles that dissolve well typically have poor dissolution while particle that disperse well are often slow to dissolve. While slow dissolution impacts cleaning performance by limiting the amount of cleaning agent available in the wash, it is poor dissolution that may have the greatest consumer noticeable impact is non soluble residues on fabrics. While not wishing to be bound by theory, it is believed that detergent residues are due in large part to the bridging of a gel-like substance between surfactant granules. This gel like residue results from the partial dissolution of surfactant to form highly viscous surfactant paste. When this gel-like substance "connects" to neighboring particles a much larger "lump" is formed. Once formed, these lump-gels are difficult to break-up, disperse and dissolve. By way of the

I

WO 01/1 1005 PCT/USOO/21484 present invention, it has been found that the interaction between electrolytes present in the surfactant particles and the class of surfactants based on alcohol sulfates is particularly problematic in a detergent composition due to lump-gel formation. On the other hand, the class of surfactants based on alkyl benzyl sulphonates have a much lower tendency to interact with electrolytes to form lump-gels. One way to minimize these electrolyte-surfactant interactions is to simply reduce the amount of electrolyte in the formulation. However, such a reduction of the typically alkaline electrolytes, for example sodium carbonate, will result in a reduction in the wash water pH and as a result a reduction in cleaning performance of the detergent composition. Therefore, it is desirable to maintain, if not increase, the level of electrolyte in the formulation. Accordingly, the need remains to improve the dissolution issues surrounding granular detergent compositions to maintain formulation flexibility over liquid detergent compositions, particularly dissolution in cold water conditions. Summary of the Invention This need is met by the present invention wherein a granular detergent composition having surfactant particles with reduced electrolyte levels is provided. In essence the present invention involves the formulation of a fully formulated detergent composition which comprises a surfactant system having an electrolyte rich surfactant zone and an electrolyte poor surfactant zone. The composition may be in the form of a single particle with separate discrete surfactant zones or may be in the form of multiple particles wherein each surfactant zone is represented by a separate particle. In highly preferred scenarios, the electrolyte poor zone is an agglomerated detergent particle and the electrolyte rich zone is a spray-dried detergent particle. The composition also includes other detergent adjunct ingredients. The electrolyte poor surfactant zone comprises less than about 20%, more preferably less than about 10%, even more preferably less than about 2% and most preferably about 0% electrolyte in conjunction with a surfactant or blend of surfactants selected from the class of alkyl sulfate surfactants. Meanwhile, the electrolyte rich surfactant zone comprises more than about 20%, more preferably more than about 35% and most preferably more than about 45% electrolyte in conjunction with a surfactant or blend of surfactants selected from an anionic surfactant which is not an alkyl sulfate surfactants, preferably alkyl benzene sulfonates. Thus, via the zone separation of the present invention wherein the electrolyte is separated from the proximity of the alkyl sulfate surfactants, the formation of lump-gel residues is minimized and/or reduced WO 01/11005 PCT/USOO/21484 resulting in both superior dissolution and dispersion profiles for the granular detergent of the present invention. Accordingly, it is an object of the present invention to provide a superior performing granular detergent composition which has the solubility profile on par with liquid detergents. In is a further object of the present invention to provide this solubility via zone separation of electrolytes and certain surfactant ingredients. It is a further object of the present invention to provide an electrolyte poor zone or particle having alkyl sulfate surfactant and an electrolyte rich zone having an anionic surfactant that is not an alkyl sulfate such as alkyl benzene sulfonate surfactants. These and other objects, features and advantages of the present invention, will be apparent to one of ordinary skill in the art from the following description and the appended claims. Detailed Description of the Preferred Embodiments Definitions As used herein, the word "particles" means the entire size range of a detergent final product or component or the entire size range of discrete particles, agglomerates, or granules in a final detergent product or component admixture. It specifically does not refer to a size fraction (i.e., representing less than 100% of the entire size range) of any of these types of particles unless the size fraction represents 100% of a discrete particle in an admixture of particles. For each type of particle component in an admixture, the entire size range of discrete particles of that type have the same or substantially similar composition regardless of whether the particles are in contact with other particles. For agglomerated components, the agglomerates themselves are considered as discrete particles and each discrete particle may be comprised of a composite of smaller primary particles and binder compositions. As used herein, the phrase "geometric mean particle diameter" means the geometric mass median diameter of a set of discrete particles as measured by any standard mass-based particle size measurement technique, preferably by dry sieving. As used herein, the phrase "geometric standard deviation" or "span" of a particle size distribution means the geometric breadth of the best-fitted log-normal function to the above-mentioned particle size data which can be accomplished by the ratio of the diameter of the 84.13 percentile divided by the diameter of the 50t" percentile of the cumulative distribution (Ds 4

.

13 /Doo); See Gotoh et al, Powder Technology Handbook, pp. 6-11, Meral Dekker 1997.. As used herein, the phrase "builder" means any inorganic material having "builder" performance in the detergency context, and specifically, organic or inorganic material capable of 3 WO 01/11005 PCT/USOO/21484 removing water hardness from washing solutions. As used herein, the term "bulk density" refers to the uncompressed, untapped powder bulk density, as measured by pouring an excess of powder sample through a funnel into a smooth metal vessel (e.g., a 500 ml volume cylinder), scraping off the excess from the heap above the rim of the vessel, measuring the remaining mass of powder and dividing the mass by the volume of the vessel. The present invention involves the design of a granular detergent composition having superior solubility via the separation of selected detergent ingredients that have increased tendency to form gels of lower solubility during the dispersion and dissolution of a granular detergent when in proximity to each other. The detergent ingredients which have been identified as having the increased tendency to form lump-gel residues are alkyl sulfate surfactants and electrolytes. Electrolytes are commonly present in detergent compositions to provide such benefits as alkalinity, building etc. and are typically present as alkali metal salts such as carbonate, chloride and sulfate salts. Most typical is sodium carbonate and is the most preferred electrolyte according to the present invention. To take advantage of the present invention, the granular detergents are divided into electrolyte poor and electrolyte rich zones. The electrolyte poor zone contains lower levels of electrolyte than that present in the electrolyte rich zone. Thus, the alkyl sulfate surfactants are concentrated in the electrolyte poor zone thereby minimizing their interaction with the electrolytes prior to complete solubility of the surfactants. The electrolyte poor zone contains less than about 20% by weight of the particle of electrolyte, preferably less than about 10% by weight and most preferably less than about 2% by weight of the particle of the electrolyte with levels around 0 being the most preferred. The electrolyte poor zone also preferably includes at least about 2%, more preferably about 5% and most preferably about 10% by weight of the particle of the alkyl sulfate surfactant. The electrolyte rich zone contains higher levels of the electrolyte than that present in the electrolyte poor zone. Accordingly, anionic surfactants other than the alkyl sulfates may be formulated into this electrolyte rich zone. Preferably, the anionic surfactant in this zone is an alkyl benzene sulfonate surfactant. The electrolyte rich zone contains more than about 20% by weight of the particle of electrolyte, preferably more than about 30%, and more preferably more than about 35% by weight of the particle of electrolyte. In addition, the electrolyte rich zone contains more than about 0% by weight of the particle of anionic surfactant, more preferably more than about 2% and most preferably more than 5% by weight of the particle. 4 WO 01/11005 PCT/USOO/21484 In preferred embodiments, the electrolyte poor zone and the electrolyte rich zone comprise separate particles differing composition as formulated into the granular detergent. The particles may be selected from spray-dried, agglomeration, extrusion, pelletization, compaction and various other particle making processes as well known in the art. In preferred examples, one particle may be a spray-dried particle while the other particle is agglomerated. Preferably, the electrolyte rich zone is a spray-dried particle while the preferred electrolyte poor zone is an agglomerated particle. Of course, one of ordinary skill in the art will recognize that other forms of particles may also be advantageous employed. In an alternate embodiment, the electrolyte rich zone and the electrolyte poor zone are separate and distinct zones of the same particle. For examples, two separate sub-particles of differing composition may be agglomerated together to form single particle having the distinct zones as described herein. Detersive surfactants The anionic surfactants useful in the present invention are split into the alkyl sulfate surfactants which according to the present invention are separated from the electrolytes in the detergent composition and the remaining anionic surfactants which may be formulated in either particle. For the purposes of the present invention, the alkyl sulfates are defined as alkyl sulfates, alkyl alkoxy sulfate, alkyl sulfonates, alkyl alkoxy carboxylate, alkyl alkoxylated sulfates with the remaining anionic surfactant being selected from the group consisting of alkylbenzene sulfonate, alpha olefin sulfonate, paraffin sulfonates, alkyl ester sulfonates, , sarcosinates, taurinates, and mixtures thereof. When present, anionic surfactant will be present typically in an effective amount in the overall detergent composition. More preferably, the composition may contain at least about 0.5%, more preferably at least about 5%, even more preferably still, at least about 10% by weight of said composition of anionic surfactant. The composition will also preferably contain no more than about 90%, more preferably no more than about 50%, even more preferably, no more than about 30% by weight of said composition of anionic surfactant. Alkyl sulfate surfactants providing excellent overall cleaning ability alone and particularly when used in combination with polyhydroxy fatty acid amides (see below), including good grease/oil cleaning over a wide range of temperatures, wash concentrations, and wash times, dissolution of alkyl sulfates can be obtained, as well as improved formulability in liquid detergent formulations are water soluble salts or acids of the formula ROSO3M wherein R preferably is a Cl 0-C24 hydrocarbyl, preferably an alkyl or hydroxyalkyl having a Cl 0-C20 alkyl component, more preferably a Cl 2-C 18 alkyl or hydroxyalkyl, and M is H or a cation, e.g., an alkali (Group 5 WO 01/11005 PCTUSOO/21484 IA) metal cation (e.g., sodium, potassium, lithium), substituted or unsubstituted ammonium cations such as methyl-, dimethyl-, and trimethyl ammonium and quaternary ammonium cations, e.g., tetramethyl-ammonium and dimethyl piperdinium, and cations derived from alkanolamines such as ethanolamine, diethanolamine, triethanolamine, and mixtures thereof, and the like. Typically, alkyl chains of C12-16 are preferred for lower wash temperatures (e.g., below about 50'C) and C16-18 alkyl chains are preferred for higher wash temperatures (e.g., above about 50-C). Another suitable type of alkyl sulfate surfactant according to the present invention are the secondary (2,3) alkyl sulfates. These surfactants preferably are of the formula: OSO3- M+ OSO3~ M*

CH

3

(CH

2 )x(CH)CH 3 or CH 3

(CH

2 )y(CH)CH 2

CH

3 wherein x and (y + 1) are integers of at least about 7, preferably at least about 9. Preferably these surfactants contain from 10 to 18 carbon atoms. Suitable examples of these anionic surfactants are disclosed in U.S. 3,234,258 Morris, issued February 8, 1966; U.S. 5,075,041 Lutz, issued December 24, 1991; U.S. 5,349,101 Lutz et al., issued September 20, 1994; and U.S. 5,389,277 Prieto, issued February 14, 1995 each incorporated herein by reference; Another suitable type of alkyl sulfate surfactant according to the present invention are the alkyl alkoxylated sulfate. These surfactants are water soluble salts or acids typically of the formula RO(A)mSO3M wherein R is an unsubstituted C1O-C24 alkyl or hydroxyalkyl group having a C1O-C24 alkyl component, preferably a C12-C20 alkyl or hydroxyalkyl, more preferably C12-C18 alkyl or hydroxyalkyl, A is an ethoxy or propoxy unit, m is greater than zero, typically between about 0.5 and about 6, more preferably between about 0.5 and about 3, and M is H or a cation which can be, for example, a metal cation (e.g., sodium, potassium, lithium, etc.), ammonium or substituted-ammonium cation. Alkyl ethoxylated sulfates as well as alkyl propoxylated sulfates are contemplated herein. Specific examples of substituted ammonium cations include methyl-, dimethyl-, trimethyl-ammonium and quaternary ammonium cations, such as tetramethyl-ammonium, dimethyl piperidinium and cations derived from alkanolamines, e.g. monoethanolamine, diethanolamine, and triethanolamine, and mixtures thereof Exemplary surfactants are C12-C18 alkyl polyethoxylate (1.0) sulfate, C12-C18 alkyl polyethoxylate (2.25) sulfate, Cl2-C18 alkyl polyethoxylate (3.0) sulfate, and Cl2-Cl8 alkyl polyethoxylate (4.0) sulfate wherein M is conveniently selected from sodium and potassium. Surfactants for use herein can be made from natural or synthetic alcohol feedstocks. Chain lengths represent average hydrocarbon distributions, including branching. The anionic surfactant component may comprise 6 WO 01/11005 PCT/USOO/21484 alkyl sulfates and alkyl ether sulfates derived from conventional alcohol sources, e.g., natural alcohols, synthetic alcohols such as those sold under the trade name of NEODOLTM, ALFOL T M ,

LIAL

TM

, LUTENSOL T M and the like. Alkyl ether sulfates are also known as alkyl polyethoxylate sulfates. Another type of alkyl sulfate surfactant according to the present invention are one or more (preferably a mixture of two or more) mid-chain branched surfactants, preferably mid-chain branched alkyl alkoxy alcohols having the formula: R RI R2

CH

3

CH

2

(CH

2 )wCH(CH 2 )xCH(CH 2 )yCH(CH 2 )z(EO/PO)mOH mid-chain branched alkyl sulfates having the formula: R R' R 2

CH

3

CH

2

(CH

2 )wCH(CH 2 )xCH(CH 2 )yCH(CH 2 )zOSO 3 M and mid-chain branched alkyl alkoxy sulfates having the formula: R R1 R2 CH3CH 2

(CH

2 )wCH(CH 2 )xCH(CH 2 )yCH(CH 2 )z(EO/PO)mOSO 3 M wherein the total number of carbon atoms in the branched primary alkyl moiety of these formulae (including the R, RI, and R 2 branching, but not including the carbon atoms which comprise any EO/PO alkoxy moiety) is from 14 to 20, and wherein further for this surfactant mixture the average total number of carbon atoms in the branched primary alkyl moieties having the above formula is within the range of greater than 14.5 to about 17.5 (preferably from about 15 to about 17); R, RI, and R 2 are each independently selected from hydrogen, CI-C 3 alkyl, and mixtures thereof, preferably methyl; provided R, RI, and R 2 are not all hydrogen and, when z is 1, at least R or RI is not hydrogen. M is a water soluble cation and may comprises more than one type of cation, for example, a mixture of sodium and potassium. The index w is an integer from 0 to 13; x is an integer from 0 to 13; y is an integer from 0 to 13; z is an integer of at least 1; provided w + x + y + z is from 8 to 14. EO and PO represent ethyleneoxy units and propyleneoxy units having the formula:

CH

3 CH 3

-CHCH

2 0- or -CH 2

CHO

respectively, however, other alkoxy units inter alia 1,3-propyleneoxy, butoxy, and mixtures thereof are suitable as alkoxy units appended to the mid-chain branched alkyl moieties. 7 WO 01/11005 PCT/USOO/21484 The mid-chain branched surfactants are preferably mixtures which comprise a surfactant system. Therefore, when the surfactant system comprises an alkoxylated surfactant, the index m indicates the average degree of alkoxylation within the mixture of surfactants. As such, the index m is at least about 0.01, preferably within the range of from about 0.1, more preferably from about 0.5, most preferably from about I to about 30, preferably to about 10, more preferably to about 5. When considering a mid-chain branched surfactant system which comprises only alkoxylated surfactants, the value of the index m represents a distribution of the average degree of alkoxylation corresponding to m, or it may be a single specific chain with alkoxylation (e.g., ethoxylation and/or propoxylation) of exactly the number of units corresponding to m. The preferred mid-chain branched surfactants of the present invention which are suitable for use in the surfactant systems of the present invention have the formula:

CH

3

CH

3

(CH

2 )aCH(CH 2 )bCH 2 (EO/PO)mOSO 3 M or the formula:

CH

3

CH

3

CH

3

(CH

2 )dCH(CH 2 )eCHCH 2 (EO/PO)mOSO 3 M wherein a, b, d, and e are integers such that a + b is from 10 to 16 and d + e is from 8 to 14; M is selected from sodium, potassium, magnesium, ammonium and substituted ammonium, and mixtures thereof. The surfactant systems of the present invention which comprise mid-chain branched surfactants are preferably formulated in two embodiments. A first preferred embodiment comprises mid-chain branched surfactants which are formed from a feedstock which comprises 25% or less of mid-chain branched alkyl units. Therefore, prior to admixture with any other conventional surfactants, the mid-chain branched surfactant component will comprise 25% or less of surfactant molecules which are non-linear surfactants. A second preferred embodiment comprises mid-chain branched surfactants which are formed from a feedstock which comprises from about 25% to about 70% of mid-chain branched alkyl units. Therefore, prior to admixture with any other conventional surfactants, the mid-chain branched surfactant component will comprise from about 25% to about 70% surfactant molecules which are non-linear surfactants. These surfactants are further described in U.S. Patent Application No. 60/061,971, Attorney docket No 6881P October 14, 1997, No. 60/061,975, Attorney docket No 6882P October 14, 1997, No. 60/062,086, Attorney docket No 6883P October 14, 1997, No. 60/061,916, 8 WO 01/11005 PCT/USOO/21484 Attorney docket No 6884P October 14, 1997, No. 60/061,970, Attorney docket No 6885P October 14, 1997, No. 60/062,407, Attorney docket No 6886P October 14, 1997,. Other suitable mid-chain branched surfactants can be found in U.S. Patent applications Serial Nos. 60/032,035 (Docket No. 6401P), 60/031,845 (Docket No. 6402P), 60/031,916 (Docket No. 6403P), 60/031,917 (Docket No. 6404P), 60/031,761 (Docket No. 6405P), 60/031,762 (Docket No. 6406P) and 60/031,844 (Docket No. 6409P). Mixtures of these branched surfactants with conventional linear surfactants are also suitable for use in the present compositions. Of the anionic surfactants according to the present invention which are not included in the alkyl sulfates according to the present invention one type of anionic surfactant which can be utilized encompasses alkyl ester sulfonates. These are desirable because they can be made with renewable, non-petroleum resources. Preparation of the alkyl ester sulfonate surfactant component can be effected according to known methods disclosed in the technical literature. For instance, linear esters of C8-C20 carboxylic acids can be sulfonated with gaseous S03 according to "The Journal of the American Oil Chemists Society," 52 (1975), pp. 323-329. Suitable starting materials would include natural fatty substances as derived from tallow, palm, and coconut oils, etc. The preferred alkyl ester sulfonate surfactant, especially for laundry applications, comprises alkyl ester sulfonate surfactants of the structural formula: 0

R

3 CHCOR4

SO

3 M wherein R3 is a CS-C20 hydrocarbyl, preferably an alkyl, or combination thereof, R4 is a Cl -C6 hydrocarbyl, preferably an alkyl, or combination thereof, and M is a soluble salt-forming cation. Suitable salts include metal salts such as sodium, potassium, and lithium salts, and substituted or unsubstituted ammonium salts, such as methyl-, dimethyl, -trimethyl, and quaternary ammonium cations, e.g. tetramethyl-ammonium and dimethyl piperdinium, and cations derived from alkanolamines, e.g. monoethanol-amine, diethanolamine, and triethanolamine. Preferably, R3 is C1O-C16 alkyl, and R4 is methyl, ethyl or isopropyl. Especially preferred are the methyl ester sulfonates wherein R3 is C14-C16 alkyl. Another type of anionic surfactant which can be utilized encompasses alkylbenzenesulphonates. These include the hard (ABS, TPBS), linear types, also known as LAS, and made by known process such as various HF or solid HF e.g., DETAL@ (UOP) process, or made by using other Lewis Acid catalysts e.g., AlCl 3 . or made using acidic silica/alumina or 9 WO 01/11005 PCT/USOO/21484 made from chlorinated hydrocarbons, such as C9-C20 linear alkylbenzene sulfonates, particularly sodium linear alkyl C1O-C15 benzene sulfonate. These surfactants are water soluble salts or acids typically of the formula RASO3M wherein R is a branched or linear CIO-C24 alkyl group, preferably a C10-C20 alkyl, more preferably C 10-C18 alkyl, A is an aryl group , preferably benzene, or toluene, more preferably benzene unit, and M is H or a cation which can be, for example, a metal cation (e.g., sodium, potassium, lithium, etc.), ammonium or substituted ammonium cation. The surfactant systems of the laundry detergent compositions of the present invention can also comprise from about 0.001%, preferably from about 1%, more preferably from about 5%, most preferably from about 10% to about 100%, preferably to about 60%, more preferably to about 30% by weight, of the surfactant system, of one or more (preferably a mixture of two or more) modified alkyl arylsulfonate surfactants, or MLAS preferably surfactants wherein the aryl unit is a benzene ring having the formula: R1R2L R3 [MqI

SO

3 a wherein L is an acyclic hydrocarbyl moiety comprising from 6 to 18 carbon atoms; R', R 2 , and R 3 are each independently hydrogen or C 1

-C

3 alkyl, provided R' and R 2 are not attached at the terminus of the L unit; M is a water soluble cation having charge q wherein a and b are taken together to satisfy charge neutrality. These and other suitable MLAS surfactants are further described in copending U.S. Patent applications No. 60/053,319 Attorney docket No 6766P filed on July 21st, 1997, No. 60/053,318, Attorney docket No 6767P filed on July 21st, 1997, No. 60/053,321, Attorney docket No 6768P filed on July 21st, 1997, No. 60/053,209, Attorney docket No 6769P filed on July 21st, 1997, No. 60/053,328, Attorney docket No 6770P filed on July 21st, 1997, No. 60/053,186, Attorney docket No 6771P filed on July 21st, 1997, No. 60/105,017 Attorney docket No 7303P filed on October 20th, 1998, No. 60/104,962 Attorney docket No 7304P filed on October 20th, 1998, and No. 60/144,519 Attorney docket No 7663P filed on July 19th, 1999. Mixtures of these modified surfactants with conventional surfactants and/or branched surfactants, such as those described herein, are also suitable for use in the present compositions. 10 WO 01/11005 PCT/USOO/21484 Examples of suitable anionic surfactants are given in "Surface Active Agents and Detergents" (Vol. I and II by Schwartz, Perry and Berch). A variety of such surfactants are also generally disclosed in U.S. Patent 3,929,678, issued December 30, 1975 to Laughlin, et al. at Column 23, line 58 through Column 29, line 23. Other anionic surfactants useful for detersive purposes can also be included in the compositions hereof. These can include salts (including, for example, sodium, potassium, ammonium, and substituted ammonium salts such as mono-, di- and triethanolamine salts) of soap, C8-C22 primary or secondary alkanesulphonates, C8-C24 olefinsulphonates, sulphonated polycarboxylic acids prepared by sulphonation of the pyrolyzed product of alkaline earth metal citrates, e.g., as described in British patent specification No. 1,082,179, alkyl glycerol sulfonates, fatty acyl glycerol sulfonates, fatty oleyl glycerol sulfates, alkyl phenol ethylene oxide ether sulfates, paraffin sulfonates, alkyl phosphates, isothionates such as the acyl isothionates, N-acyl taurates, fatty acid amides of methyl tauride, alkyl succinamates and sulfosuccinates, monoesters of sulfosuccinate (especially saturated and unsaturated C12-C18 monoesters) diesters of sulfosuccinate (especially saturated and unsaturated C6-Cl4 diesters), N-acyl sarcosinates, sulfates of alkylpolysaccharides such as the sulfates of alkylpolyglucoside (the nonionic nonsulfated compounds being described below), branched primary alkyl sulfates, alkyl polyethoxy carboxylates such as those of the formula RO(CH2CH2O)kCH2COO-M+ wherein R is a C8-C22 alkyl, k is an integer from 0 to 10, and M is a soluble salt-forming cation, and fatty acids esterified with isethionic acid and neutralized with sodium hydroxide. Resin acids and hydrogenated resin acids are also suitable, such as rosin, hydrogenated.rosin, and resin acids and hydrogenated resin acids present in or derived from tall oil. Further examples are given in "Surface Active Agents and Detergents" (Vol. I and II by Schwartz, Perry and Berch). A variety of such surfactants are also generally disclosed in U.S. Patent 3,929,678, issued December 30, 1975 to Laughlin, et al. at Column 23, line 58 through Column 29, line 23. Another type of useful anionic surfactant are the so-called dianionics. These are surfactants which have at least two anionic groups present on the surfactant molecule. Some suitable dianionic surfactants are further described in copending U.S. Serial No. 60/020,503 (Docket No. 6160P), 60/020,772 (Docket No. 6161P), 60/020,928 (Docket No. 6158P), 60/020,832 (Docket No. 6159P) and 60/020,773 (Docket No. 6162P) all filed on June 28, 1996, and 60/023,539 (Docket No. 6192P), 60/023493 (Docket No. 6194P), 60/023,540 (Docket No. 6193P) and 60/023,527 (Docket No. 6195P) filed on August 8th, 1996, the disclosures of which are incorporated herein by reference. 11 WO 01/11005 PCT/USOO/21484 DETERGENT COMPONENTS The detergent composition can, and preferably does, include a detergent builder. Builders are generally selected from the various water-soluble, alkali metal, ammonium or substituted ammonium phosphates, polyphosphates, phosphonates, polyphosphonates, carbonates, silicates, borates, polyhydroxy sulfonates, polyacetates, carboxylates, and polycarboxylates. Preferred are the alkali metal, especially sodium, salts of the above. Preferred for use herein are the phosphates, carbonates, silicates, C10-1 8 fatty acids, polycarboxylates, and mixtures thereof. More preferred are sodium tripolyphosphate, tetrasodium pyrophosphate, citrate, tartrate mono- and di-succinates, sodium silicate, and mixtures thereof (see below). Specific examples of inorganic phosphate builders are sodium and potassium tripolyphosphate, pyrophosphate, polymeric metaphosphate having a degree of polymerization of from about 6 to 21, and orthophosphates. Examples of polyphosphonate builders are the sodium and potassium salts of ethylene diphosphonic acid, the sodium and potassium salts of ethane 1-hydroxy-1, 1-diphosphonic acid and the sodium and potassium salts of ethane, 1,1,2-triphosphonic acid. Other phosphorus builder compounds are disclosed in U.S. Patents 3,159,581; 3,213,030; 3,422,021; 3,422,137; 3,400,176 and 3,400,148, all of which are incorporated herein by reference. Examples of nonphosphorus, inorganic builders are sodium and potassium carbonate, bicarbonate, sesquicarbonate, tetraborate decahydrate, and silicates having a weight ratio of SiO 2 to alkali metal oxide of from about 0.5 to about 4.0, preferably from about 1.0 to about 2.4. Water-soluble, nonphosphorus organic builders useful herein include the various alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates and polyhydroxy sulfonates. Examples of polyacetate and polycarboxylate builders are the sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylene diamine tetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, and citric acid. Polymeric polycarboxylate builders are set forth in U.S. Patent 3,308,067, Diehl, issued March 7, 1967, the disclosure of which is incorporated herein by reference. Such materials include the water-soluble salts of homo- and copolymers of aliphatic carboxylic acids such as maleic acid, itaconic acid, mesaconic acid, fumaric acid, aconitic acid, citraconic acid and methylenemalonic acid. Some of these materials are useful as the water-soluble anionic polymer as hereinafter described, but only if in intimate admixture with the nonsoap anionic surfactant. 12 WO 01/11005 PCTUSOO/21484 Other suitable polycarboxylates for use herein are the polyacetal carboxylates described in U.S. Patent 4,144,226, issued March 13, 1979 to Crutchfield et al., and U.S. Patent 4,246,495, issued March 27, 1979 to Crutchfield et al., both of which are incorporated herein by reference. These polyacetal carboxylates can be prepared by bringing together under polymerization conditions an ester of glyoxylic acid and a polymerization initiator. The resulting polyacetal carboxylate ester is then attached to chemically stable end groups to stabilize the polyacetal carboxylate against rapid depolymerization in alkaline solution, converted to the corresponding salt, and added to a detergent composition. Particularly preferred polycarboxylate builders are the ether carboxylate builder compositions comprising a combination of tartrate monosuccinate and tartrate disuccinate described in U.S. Patent 4,663,071, Bush et al., issued May 5, 1987, the disclosure of which is incorporated herein by reference. Water-soluble silicate solids represented by the formula SiO 2eM 0 M being an alkali metal, and having a SiO 2

:M

2 0 weight ratio of from about 0.5 to about 4.0, are useful salts in the detergent granules of the invention at levels of from about 2% to about 15% on an anhydrous weight basis, preferably from about 3% to about 8%. Anhydrous or hydrated particulate silicate can be utilized, as well. Any number of additional ingredients can also be included as components in the granular detergent composition. These include other detergency builders, bleaches, bleach activators, suds boosters or suds suppressors, anti-tarnish and anti-corrosion agents, soil suspending agents, soil release agents, germicides, pH adjusting agents, nonbuilder alkalinity sources, chelating agents, smectite clays, enzymes, enzyme-stabilizing agents and perfumes. See U.S. Patent 3,936,537, issued February 3, 1976 to Baskerville, Jr. et al., incorporated herein by reference. Bleaching agents and activators are described in U.S. Patent 4,412,934, Chung et al., issued November 1, 1983, and in U.S. Patent 4,483,781, Hartman, issued November 20, 1984, both of which are incorporated herein by reference. Chelating agents are also described in U.S. Patent 4,663,071, Bush et al., from Column 17, line 54 through Column 18, line 68, incorporated herein by reference. Suds modifiers are also optional ingredients and are described in U.S. Patents 3,933,672, issued January 20, 1976 to Bartoletta et al., and 4,136,045, issued January 23, 1979 to Gault et al., both incorporated herein by reference. Suitable smectite clays for use herein are described in U.S. Patent 4,762,645, Tucker et al., issued August 9, 1988, Column 6, line 3 through Column 7, line 24, incorporated herein by reference. Suitable additional detergency builders for use herein are enumerated in the 13 WO 01/11005 PCT/US00/21484 Baskerville patent, Column 13, line 54 through Column 16, line 16, and in U.S. Patent 4,663,071, Bush et al., issued May 5, 1987, both incorporated herein by reference. The following examples are presented for illustrative purposes only and are not to be construed as limiting the scope of the appended claims in any way. Abbreviations used in Examples In the detergent compositions, the abbreviated component identifications have the following meanings: LAS : Sodium linear C 11-13 alkyl benzene sulfonate TAS : Sodium tallow alkyl sulfate C45AS : Sodium C14 - Cl5 alkyl sulfate C45E3S : Sodium C14-C15 alkyl sulfate condensed with 3 moles of ethylene oxide QAS : R2.N+(CH3)2(C2H40H) with R2 = C12 - C14 Soap : Sodium linear alkyl carboxylate derived from an 80/20 mixture of tallow and coconut fatty acids Zeolite A : Hydrated sodium aluminosilicate of formula Nal2(AlO2SiO2)12.27H20 having a primary particle size in the range from 0.1 to 10 micrometers (weight expressed on an anhydrous basis) NaSKS-6 : Crystalline layered silicate of formula 6- Na2Si205 Citric acid : Anhydrous citric acid Carbonate : Anydrous sodium carbonate with a particle size between 200ptm and 900pm Bicarbonate : Anhydrous sodium bicarbonate with a particle size distribution between 400pm and 1200pm Silicate : Amorphous sodium silicate (Si02:Na2O = 2.0:1) Sulfate : Anhydrous sodium sulfate Mg sulfate : Anhydrous magnesium sulfate Citrate : Tri-sodium citrate dihydrate of activity 86.4% with a particle size distribution between 425pm and 850pm MA/AA : Copolymer of 1:4 maleic/acrylic acid, average molecular weight about 70,000 AA : Sodium polyacrylate polymer of average molecular weight 4,500 14 WO 01/1 1005 PCT/USOO/21484 CMC : Sodium carboxymethyl cellulose Protease Proteolytic enzyme, having 4% by weight of active enzyme, as described in WO 95/10591, sold by Genencor Int. Inc. Cellulase Cellulytic enzyme, having 0.23% by weight of active enzyme, sold by NOVO Industries A/S under the tradename Carezyme Amylase : Amylolytic enzyme, having 1.6% by weight of active enzyme, sold by NOVO Industries A/S under the tradename Termamyl 120T Lipase : Lipolytic enzyme, having 2.0% by weight of active enzyme, sold by NOVO Industries A/S under the tradename Lipolase Perborate : Sodium perborate Percarbonate : Sodium percarbonate NOBS Nonanoyloxybenzene sulfonate in the form of the sodium salt NAC-OBS (6-nonamidocaproyl) oxybenzene sulfonate TAED : Tetraacetylethylenediamine DTPA Diethylene triamine pentaacetic acid EDDS Ethylenediamine-N,N'-disuccinic acid, (S,S) isomer in the form of its sodium salt. Photoactivated : Sulfonated zinc phthlocyanine encapsulated in bleach (1) dextrin soluble polymer Brightener : Disodium 4,4'-bis(4-anilino-6-morpholino-1.3.5-triazin-2-yl)amino) stilbene-2:2'-disulfonate HEDP 1,1-hydroxyethane diphosphonic acid PEGx : Polyethylene glycol, with a molecular weight of x (typically 4,000) QEA bis((C2H5O)(C2H40)n)(CH3) -N+-C6H12-N+-(CH3) bis((C2H50) (C21-14 O))n, wherein n = from 20 to 30 SRP Diethoxylated poly (1, 2 propylene terephtalate) short block polymer Silicone antifoam : Polydimethylsiloxane foam controller with siloxane-oxyalkylene copolymer as dispersing agent with a ratio of said foam controller to said dispersing agent of 10:1 to 100:1 In the following examples all levels are quoted as % by weight of the composition: 15 WO 01/11005 PCT/USOO/21484 Example I The following compositions are in accordance with the invention. A B C D E F G H I Spray-dried Granules LAS 10.0 10.0 15.0 5.0 5.0 10.0 QAS 1.0 1.0 - - DTPA, HEDP and/or 0.3 0.3 0.5 0.3 EDDS MgSO4 0.5 0.5 0.1 - - - Sodium citrate - - - 3.0 5.0 - - Sodium carbonate 10.0 10 15 10 7 10 - - Sodium sulphate 5.0 5.0 - - 5.0 3.0 - - Sodium silicate 1.6R - - - - 2.0 - - Zeolite A 16.0 18.0 20.0 20.0 - - - - SKS-6 - - - 3.0 5.0 - - - MA/AA or AA 1.0 2.0 11.0 - - 2.0 - - PEG 4000 - 2.0 - 1.0 - 1.0 - - QEA 1.0 - - - 1.0 - - - Brightener 0.05 0.05 0.05 - 0.05 - - - Silicone oil 0.01 0.01 0.01 - - 0.01 - - Agglomerate LAS - - - - 0.2 0.2 0.01

C

4 5 AS - - - 2.0 - 1.0 AE3 - - - - - 1.0 0.5 Carbonate - - 4.0 1.0 1.0 1.0 Sodium citrate - - - - - - 5.0 CFAA - - Citric acid - - - 4.0 - 1.0 1.0 QEA - - - 2.0 2.0 1.0 SRP - - - 1.0 1.0 0.2 16 WO 01/11005 PCT/USOO/21484 Zeolite A - - - 15.0 26.0 15.0 16.0 Sodium silicate -- - - PEG - - - .0 - Builder Agglomerates SKS-6 6.0 - - - 6.0 3.0 - 7.0 10.0 LAS 4.0 5.0 - - 5.0 3.0 - 10.0 12.0 Dry-add particulate components Malic 8.0 - 10.0 4.0 - 8.0 - - 4.0 acid/carbonate/bicarbonat e (40:20:40) QEA - - - 0.2 0.5 - - - NACAOBS 3.0 - - 1.5 - - - 2.5 NOBS - 3.0 3.0 - - - - - 5.0 TAED 2.5 - - 1.5 2.5 6.5 - 1.5 LAS (flake) 10.0 10.0 - - - - - 8.0 Spray-on Brightener 0.2 0.2 0.3 0.1 0.2 0.1 - 0.6 Dye - - - 0.3 0.05 0.1 - - AE7 - - - - - 0.5 - 0.7 Perfume - - - 0.8 - 0.5 - .5 Dry-add Citrate - - 20.0 4.0 - 5.0 15.0 - 5.0 Percarbonate 15.0 3.0 6.0 10.0 - - - 18.0 5.0 Perborate - - - - 6.0 18.0 - - Photobleach 0.02 0.02 0.02 0.1 0.05 - 0.3 - 0.03 17 WO 01/11005 PCT/USOO/21484 Enzymes (cellulase, 1.3 0.3 0.5 0.5 0.8 2.0 0.5 0.16 0.2 amylase, protease, lipase) Carbonate 0.0 10.0 - - - 5.0 8.0 10.0 5.0 Perfume (encapsulated) 0.6 0.5 0.5 - 0.3 0.5 0.2 0.1 0.6 Suds suppressor 1.0 0.6 0.3 - 0.10 0.5 1.0 0.3 1.2 Soap 0.5 0.2 0.3 3.0 0.5 - - 0.3 Citric acid - - - 6.0 6.0 - - - 5.0 Dyed carbonate (blue, 0.5 0.5 1.0 2.0 - 0.5 0.5 0.5 1.0 green) SKS-6 - - - 4.0 - - - 6.0 Fillers up to 100% The compositions exemplified above have at least 90% by weight of particles having a geometric mean particle diameter of from about 850 microns with a geometric standard deviation of from about 1.2. Unexpectedly, the compositions have improved aesthetics, flowability and solubility. Having thus described the invention in detail, it will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is described in the specification. 18

Claims (16)

1. A granular detergent composition characterized by: i) from 0.01% to 60% by weight of said composition of a surfactant system having an electrolyte rich surfactant zone and a electrolyte poor surfactant zone, said electrolyte rich zone characterized by an electrolyte and an anionic surfactant which is not an alkyl sulfate surfactant wherein said electrolyte is characterized by at least 20% by weight of said electrolyte rich zone and said electrolyte poor zone characterized by an electrolyte and an alkyl sulfate surfactant wherein said electrolyte is characterized by less than 20% by weight of said electrolyte poor zone; and ii) the balance characterized by detergent adjunct ingredients.

2. The detergent composition as claimed in Claim 1 wherein said electrolyte rich zone and said electrolyte poor zone are discrete zones within a detergent particle.

3. The detergent composition as claimed in any of Claims 1-2 wherein said electrolyte rich zone and said electrolyte poor zone are separate, discrete particles within said detergent composition.

4. The detergent composition as claimed in any of Claims 1-3 wherein said electrolyte in said electrolyte rich zone is characterized by at least 35% by weight of said zone.

5. The detergent composition as claimed in any of Claims 1-4 wherein said electrolyte in said electrolyte poor zone is characterized by less than 10% by weight of said zone, preferably less than 2% by weight of said zone.

6. The detergent composition as claimed in any of Claims 1-5 wherein said alkyl sulfate surfactant is selected from C 14 CI 5 alkyl sulfate blends.

7. The detergent composition as claimed in any of Claims 1-6 wherein said electrolyte rich zone is characterized by at least 2% by weight of an alkyl benzene sulfonate surfactant. 19 WO 01/11005 PCT/USOO/21484

8. The detergent composition as claimed in any of Claims 1-7 wherein said electrolyte poor zone is characterized by at least 2% by weight of an alkyl sulfate surfactant.

9. The detergent composition as claimed in any of Claims 1-8 wherein said alkyl benzene sulfonate surfactant is selected from C 1 -C 1 3 alkyl benzene sulfonate surfactant.

10. The detergent composition as claimed in any of Claims 1-9 wherein said electrolyte is an alkali metal salt.

11. The detergent composition as claimed in any of Claims 1-10 wherein said electrolyte is an alkali metal carbonate.

12. A granular detergent composition having an average bulk density of at least 450 g/L characterized by: i) a spray-dried surfactant particle wherein said particle wherein particle is characterized by at least 2% by weight of the particle of an alkyl benzene sulfonate surfactant and at least 20% by weight of said particle of an electrolyte; and ii) an agglomerated surfactant particle wherein said particle is characterized by at least 2% by weight of the particle of an alkyl sulfate surfactant and less than 10% by weight of said particle of an electrolyte.

13. The detergent composition as claimed in any of Claims 1-12 wherein said alkyl sulfate surfactant is selected from C 14 - 15 alkyl sulfate.

14. The detergent composition as claimed in any of Claims 1-13 wherein said alkyl benzene sulfonate surfactant is selected from C 1 -C 13 alkyl benzene sulfonate surfactant.

15. The detergent composition as claimed in any of Claims 1-14 wherein said electrolyte is an alkali metal salt.

16. The detergent composition as claimed in any of Claims 1-15 wherein said electrolyte is an alkali metal carbonate. 20