WO2001011005A1

WO2001011005A1 - Granular detergent compositions having surfactant particle with reduced electrolyte concentrations

Info

Publication number: WO2001011005A1
Application number: PCT/US2000/021484
Authority: WO
Inventors: Paul R. Mort, Iii; David Scott Bohlen; Sharon Anne Graves; Lester John Hollihan
Original assignee: The Procter & Gamble Company
Priority date: 1999-08-10
Filing date: 2000-08-07
Publication date: 2001-02-15
Also published as: CA2380327A1; JP2003506564A; EP1204736A1; CN1230520C; MA25541A1; HUP0202875A3; AR025083A1; AU6623600A; KR100462265B1; CZ2002451A3; TR200200329T2; CN1370223A; BR0013082A; EG22449A; MXPA02001515A; KR20020016004A; AU777235B2; HUP0202875A2

Abstract

A granular detergent composition is provided in which from about 0.01 % to about 60 % by weight of the detergent is a surfactant system having an electrolyte rich surfactant zone and a electrolyte poor surfactant zone. The electrolyte rich zone includes an electrolyte and an anionic surfactant which is not an alkyl sulfate surfactant wherein the electrolyte comprises at least about 20 % by weight of the electrolyte rich zone. The electrolyte poor zone includes an electrolyte and an alkyl sulfate surfactant wherein the electrolyte comprises less than about 20 % by weight of the electrolyte poor zone.

Description

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 m particular to detergent compositions with surfactant particles of reduced carbonate levels

Background of the Invention

In recent yeais, the popularity of liquid detergent compositions has been on the rise This growing popularity is due m large part to superiority in dispersion and dissolution of liquid detergents 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 m 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 m 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 dissoh e. By way of the 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 m 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 m the formulation. However, such a reduction of the typically alkaline electrolytes, for example sodium carbonate, will result in a reduction the wash water pH and as a result a reduction m cleaning peiformance of the detergent composition Therefore, it is desirable to maintain, if not increase, the level of electrolyte m the formulation.

Accordingly, the need remains to improλ'e the dissolution issues surrounding granular detergent compositions to maintain formulation flexibility over liquid detergent compositions, particularly dissolution m 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 m 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 m 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 m conjunction with a surfactant or blend of surfactants selected from an anionic surfactant which is not an alkyl sulfate suifactants, 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 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 sieλ'ing. 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 50^th percentile of the cumulative distribution (D_{S .13}/D₅o); 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 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 nm 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 pieferred 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 m the electrolyte rich zone. Thus, the alkyl sulfate surfactants are concentrated m 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. In preferred embodiments, the electrolyte poor zone and the electrolyte nch zone comprise separate particles diffeπng 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 m 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 m the detergent composition and the remaining anionic surfactants which may be formulated m 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 amomc surfactant being selected from the group consisting of alkylbenzene sulfonate, alpha olefin sulfonate, paraffin sulfonates, alkyl ester sulfonates, , sarcosinates, taurmates, and mixtures thereof.

When present, amomc surfactant will be present typically m an effective amount m 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%o by weight of said composition of amomc 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 formulabihty liquid detergent formulations are water soluble salts or acids of the formula ROS03M wherein R preferably is a C10-C24 hydrocarbyl, preferably an alkyl or hydioxyalkyl having a C10-C20 alkyl component, more preferably a C12-C18 alkyl or hydroxyalkyl, and M is H or a cation, e g , an alkali (Group IA) metal cation (e.g , sodium, potassium, lithium), substituted or unsubstituted ammonium cations such as methyl-, dimethyl-, and tπmethyl ammonium and quaternary ammonium cations, e.g., tetramethyl -ammonium and dimethyl piperdimum, and cations derived from alkanolammes such as ethanolam e, diethanolamme, tπethanolamme, and mixtures thereof, and the like Typically, alkyl chains of C 12-16 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- ϊvT

CH₃(CH₂)_X(CH)CH₃ or CH₃(CH2)_y(CH)CH₂CH₃ 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 amomc surfactants are disclosed m 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 Pπeto, 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)mS03M wherein R is an unsubstituted C10-C24 alkyl or hydroxyalkyl group having a C10-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-ammomum cation. Alkyl ethoxylated sulfates as well as alkyl propoxylated sulfates are contemplated herein Specific examples of substituted ammonium cations include methyl-, dimethyl-, tπmethyl-ammomum and quaternary ammonium cations, such as tetramethyl-ammomum, dimethyl pipeπdinium and cations derived from alkanolammes, e.g monoethanolamme, diethanolamme, and tπethanolamine, and mixtures thereof Exemplary surfactants are C12-C18 alkyl polyethoxylate (1.0) sulfate, C12-C18 alkyl polyethoxylate (2.25) sulfate, C12-C18 alkyl polyethoxylate (3 0) sulfate, and C12-C18 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 Cham lengths represent average hydrocarbon distributions, including branching The amomc surfactant component may comprise 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 NEODOL™, ALFOL™, LIAL™, LUTENSOL™ 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-cham branched surfactants, preferably mid-cham branched alkyl alkoxy alcohols having the formula:

R R¹ R²

I I I

CH₃CH₂(CH₂)_wCH(CH₂)_xCH(CH₂)_yCH(CH₂)_z(EO/PO)_mOH mid-cham branched alkyl sulfates having the formula:

R R¹ R²

CH₃CH₂(CH₂)_wCH(CH₂)_xCH(CH₂)_yCH(CH₂)_zOS0₃M and mid-cham branched alkyl alkoxy sulfates having the formula-

R R¹ R²

CH₃CH₂(CH₂)_wCH(CH₂)_xCH(CH₂)_yCH(CH₂)_z(EO/PO)_mOSθ₃M wherein the total number of carbon atoms m the branched primary alkyl moiety of these formulae (including the R, R , and R^ 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 withm 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. Cj-Cβ alkyl, and mixtures thereof, preferably methyl; provided R, R , and R^ 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:

CH₃ CH₃

I I CHCH₂0 or CH₂CHO respectively, however, other alkoxy units inter aha 1,3-propyleneoxy. butoxy, and mixtures thereof are suitable as alkoxy units appended to the mid-cham branched alkyl moieties 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 withm the mixture of surfactants. As such, the index m is at least about 0.01 , preferably with the range of from about 0.1, more preferably from about 0.5, most preferably from about 1 to about 30. preferably to about 10. more preferably to about 5. When considering a mid-cham branched surfactant system which comprises only alkoxylated surfactants, the value of the index m lepresents 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-cham branched surfactants of the present invention which are suitable for use in the surfactant systems of the present invention have the formula:

CH₃

I

CH₃(CH₂)_aCH(CH₂)_bCH₂(EO/PO)_mOS0₃M or the formula:

CH₃ CH₃

I I

CH₃(CH₂)_dCH(CH₂)_eCHCH₂(EO/PO)_mOS0₃M 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-cham branched surfactants are preferably formulated m two embodiments. A first preferred embodiment comprises mid-chain branched surfactants which are formed from a feedstock which comprises 25% or less of mid-cham branched alkyl units. Therefore, prior to admixture with any other conventional surfactants, the mid-cham branched surfactant component will comprise 25% or less of surfactant molecules which are non-lmear surfactants

A second preferred embodiment comprises mid-cham branched surfactants which are formed from a feedstock which comprises from about 25% to about 70% of mid-cham branched alkyl units. Therefore, prior to admixture with any other conventional surfactants, the mid-cham branched surfactant component will comprise from about 25% to about 70% surfactant molecules which are non-lmear surfactants.

These surfactants are further described m 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, 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. 640 IP), 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:

O

3 'I 4 R³CHCOR⁴

I

SO₃M wherein R3 is a C8-C20 hydrocarbyl, preferably an alkyl, or combination thereof, R4 is a C1-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 alkanolammes, e.g. monoethanol-amine, diethanolamme, and triethanolamine. Preferably, R3 is C10-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., A1C1₃. or made using acidic silica/alumina or made from chlorinated hydrocarbons, such as C9-C20 linear alkylbenzene sulfonates, particularly sodium linear alkyl C10-C15 benzene sulfonate. These surfactants are water soluble salts or acids typically of the formula RAS03M wherein R is a branched or linear C10-C24 alkyl group, preferably a C10-C20 alkyl, more preferably C10-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 aiyl unit is a benzene ring having the formula:

wherein L is an acyclic hydrocarbyl moiety comprising from 6 to 18 carbon atoms; R¹, R², and R³ are each independently hydrogen or C C₃ alkyl, provided R¹ and R² 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. Examples of suitable amomc surfactants are given "Surface Active Agents and Detergents" (Vol. I and II by Schwartz, Perry and Berch). A variety of such surfactants are also generally disclosed m U S. Patent 3,929,678, issued December 30, 1975 to Laughlm. et al. at Column 23, line 58 through Column 29, line 23.

Other amomc 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 triethanolamme salts) of soap, C8-C22 primary or secondary alkanesulphonates, C8-C24 olefinsulphonates, sulphonated polycarboxyhc acids prepared by sulphonation of the pyrolyzed product of alkaline earth metal citrates, e.g., as described in Bntish 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 tauπde, alkyl succmamates and sulfosuccmates, monoesters of sulfosuccmate (especially saturated and unsaturated C12-C18 monoesters) diesters of sulfosuccmate (especially saturated and unsaturated C6-C14 diesters), N-acyl sarcosmates, sulfates of alkylpolysacchaπdes such as the sulfates of alkylpolyglucoside (the nomonic nonsulfated compounds being described below), branched primary alkyl sulfates, alkyl polyethoxy carboxylates such as those of the formula RO(CH2CH20)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 esteπfied with lsethiomc acid and neutralized with sodium hydroxide. Resm acids and hydrogenated resin acids are also suitable, such as rosm, hydrogenated rosm. and resin acids and hydrogenated res 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 vanety of such surfactants are also generally disclosed m U.S. Patent 3,929,678, issued December 30, 1975 to Laughlm, et al. at Column 23, line 58 through Column 29, line 23.

Another type of useful anionic surfactant are the so-called diamonics. These are surfactants which have at least two amomc groups present on the surfactant molecule. Some suitable dianiomc surfactants are further described m copendmg 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 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, C. „ , „ fatty acids, polycarboxylates, and

1 - 1 o 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 diphosphomc acid, the sodium and potassium salts of ethane 1-hydroxy-l, 1 -diphosphomc acid and the sodium and potassium salts of ethane, 1 , 1 ,2-tπphosphomc acid. Other phosphorus builder compounds are disclosed m 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^ 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 diamme tetraacetic acid, nitrilotπacetic acid, oxydisuccimc acid, melhtic acid, benzene polycarboxyhc acids, and citnc acid.

Polymenc 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 carboxyhc acids such as maleic acid, ltaco c acid, mesaco c acid, fumaπc acid, acomtic acid, citracomc acid and methylenemalonic acid. Some of these materials aie useful as the water-soluble amomc polymer as hereinafter described, but only if m intimate admixture with the nonsoap amomc surfactant. 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 glyoxyhc 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 depolymeπzation m 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 monosuccmate and tartrate disuccmate described m 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 SιO,»M„0. M being an alkali metal, and having a SιO~:M~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-stabihzmg 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. Chelatmg 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 m 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 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 m any way. Abbreviations used in Examples

In the detergent compositions, the abbreviated component identifications have the following meanings:

LAS Sodium linear CI 1-13 alkyl benzene sulfonate

TAS Sodium tallow alkyl sulfate

C45AS Sodium C14 - C15 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 alummosihcate of formula

Nal2(A102Sι02)12.27H20 having a primary particle size m the range from 0 1 to 10 micrometers (weight expressed on an anhydrous basis)

NaSKS-6 Crystalline layered silicate of formula δ- Na2Sι205 Citric acid Anhydrous citnc acid Carbonate Anydrous sodium carbonate with a particle size between 200 μm and

900μm

Bicarbonate Anhydrous sodium bicarbonate with a particle size distribution between

400μm and l200μm

Silicate Amorphous sodium silicate (Sι02.Na20 = 2.0:1) Sulfate Anhydrous sodium sulfate Mg sulfate Anhydrous magnesium sulfate Citrate Tπ-sodium citrate dihydrate of activity 86.4% with a particle size distribution between 425μm and 850μm

MA/AA Copolymer of 1 :4 maleic/acryhc acid, average molecular weight about

70,000

AA Sodium polyacrylate polymer of average molecular weight 4,500 CMC Sodium carboxymethyl cellulose Protease Proteolytic enzyme, having 4% by weight of active enzyme, as described in WO 95/10591 , sold by Genencor Int. lnc

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-nonamιdocaproyl) oxybenzene sulfonate

TAED Tetraacetyl ethyl enedi amine

DTPA Diethylene tπamme pentaacetic acid

EDDS Ethylenedιamme-N,N'-dιsuccmιc acid, (S,S) isomer m the form of its sodium salt.

Photoactivated Sulfonated zinc phthlocyanme encapsulated in bleach ( 1 ) dextrin soluble polymer

Bπghtener Dιsodιum 4,4'-bιs(4-anιlιno-6-mo holmo-1.3.5-tπazm-2-yl)ammo) stιlbene-2.2'-dιsulfonate

HEDP 1 , 1 -hydroxyethane diphospho c acid PEGx Polyethylene glycol, with a molecular weight of x (typically 4,000) QEA bιs((C2H50)(C2H40)n)(CH3) -N+-C6H12-N+-(CH3) bιs((C2H50)-

(C2H4 0))n, wherein n = from 20 to 30

SRP Diethoxylated poly (1, 2 propylene terephtalate) short block polymer

Sihcone 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 Example I The following compositions are m accordance with the invention.

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, fiowability 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.

Claims

What is claimed is:

1. A granular detergent composition characterized by.

1) 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 n) 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 withm a detergent particle.

3. The detergent composition as claimed m any of Claims 1-2 wherein said electrolyte rich zone and said electrolyte poor zone are separate, discrete particles withm 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 m 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 C₁₄ Cι₅ 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.

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 m any of Claims 1-8 wherein said alkyl benzene sulfonate surfactant is selected from Cn-Cπ 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: l) 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 u) 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 Cι₄-_]5 alkyl sulfate.

14. The detergent composition as claimed in any of Claims 1-13 wherein said alkyl benzene sulfonate surfactant is selected from Cn-C₁₃ 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.