MXPA00006863A - Granular compositions having improved dissolution - Google Patents

Abstract

A detergent composition having optimally selected physical properties of various particulate detergent ingredients is disclosed. The composition includes from about 1%to about 50%, based on the total number of discrete particles in the composition, of substantially sticky particles containing mid to high weight fractions of substantially sticky surfactants. In addition, the substantially sticky particles have a specified particle size, particle size distribution and bulk density. Additionally, thecomposition includes greater than about 35%, based on the total number of discrete particles in the composition, substantially non-sticky particles having a specified particle size, particle size distribution, and bulk density. The total amount of surfactants, including both sticky and non-sticky surfactants, in the composition is at least 15%by weight of the composition.

Description

GRANULATED COMPOSITIONS THAT HAVE IMPROVED DISSOLUTION FIELD OF THE INVENTION The present invention relates to improving the dissolution of a granular detergent composition, especially in low temperature washing solutions (i.e., less than about 30 ° C). More particularly, the detergent composition contains particles having optimally selected physical properties, such as particle size, particle density and concentration of detergent ingredients, to achieve improved dissolution performance.

BACKGROUND OF THE INVENTION Recently there has been considerable interest in the detergent industry for laundry detergents that are "compact" and therefore have low dosage volumes. To facilitate the production of these so-called low dosage detergents, various attempts have been made to produce detergents with high overall density, for example, with a density of 600 g / l or more. These low dosage detergents are currently in high demand, since they conserve resources and can be sold in small packages that are more convenient for consumers. Unfortunately, such low dosage or "compact" detergent products experience dissolution problems, especially in washing solutions at low temperatures (i.e., less than about 30 ° C). More specifically, a poor solution results in the formation of "agglutinates" which appear as solid white masses that remain in the washing machine or on the washed fabrics after conventional washing cycles. These "agglomerates" are especially prevalent under washing conditions at low temperatures and / or when the order of addition to the washing machine is first the laundry detergent, then the laundry and water at the end (commonly known as the "order of addition"). reverse "or" ROOA "). Similarly, this phenomenon of agglomerate formation can contribute to an incomplete supply of detergent in washing machines equipped with receptacles for delivery or in other delivery devices, such as a granule. In this case, the unpleasant result is an undissolved detergent residue in the delivery device. It has been found that the cause of the aforementioned dissolution problem is associated with the "bridging" of a "gel-like" substance between particles containing surfactant to form the undesirable "agglutinates". The gel-like substance responsible for the undesirable "bridge" of particles in "agglomerates", originates from the partial dissolution of the surfactant in aqueous washing solutions, in which said partial dissolution causes the formation of a phase or paste of the agent highly viscous surfactant that binds or otherwise "bridges" with other surfactant-containing particles together to form "agglomerates". This undesirable phenomenon of dissolution is commonly known as "grumo-gel" formation. In addition to the "bridging" effect of the viscous surfactant, the inorganic salts have a tendency to hydrate which can also cause "bridging" of particles that are linked together by hydration. In particular, the inorganic salts are hydrated with each other to form a cage structure which exhibits a deficient solution and which eventually ends up as a "caking" after the wash cycle. Therefore, it would be desirable to have a detergent composition that does not experience the dissolution problems identified above to result in improved cleaning performance. The prior art is replete with descriptions that refer to dissolution problems associated with granular detergent compositions. For example, the prior art suggests limiting the use and form of inorganic salts that can cause agglomerates by "bridging" hydrated salts during the wash cycle. The specific ratios of selected inorganic salts are contemplated in such a way that dissolution problems are minimized. Nevertheless, said solution restricts the formulation and processing flexibility that are necessary for a normal commercialization of large-scale detergent products. Various other mechanisms have been suggested by the prior art, all of which include alteration of the formulation, and therefore reduce the flexibility thereof. As a consequence, it would then be desirable to have a detergent composition having improved dissolution without significantly inhibiting the flexibility of the formulation. Accordingly, in spite of the prior art disclosures mentioned above, it would be desirable to have a detergent composition exhibiting an improved cleaning performance. Also, it would be desirable to have a detergent composition that exhibits said improved solution without significantly inhibiting the flexibility of the formulation.

BRIEF DESCRIPTION OF THE INVENTION The invention satisfies the above needs by providing a detergent composition having improved dissolution in its washing solutions, especially in solutions which are maintained at low temperatures (i.e., less than about 30 ° C). A combination of optimally selected physical properties of various particulate detergent ingredients in a detergent composition is used to achieve improved dissolution performance. Specifically, the detergent composition comprises from about 1% to about 50%, based on the total number of individual particles in the composition, of "substantially sticky particles" with certain specifications of composition, size and density. The substantially sticky particles contain at least about 15%, by weight of the sticky particles, of a "substantially tacky surfactant". In addition, the substantially sticky particles have a geometric average particle diameter size of about 300 microns to about 700 microns, with a standard geometric deviation of less than about 1.8, and an overall density of at least about 450g / 1. In addition, the composition includes at least about 35%, based on the total number of individual particles in the mixed composition, of substantially non-tacky particles having a geometric average particle diameter size of about 200 microns to about 500 microns. , with a standard geometric deviation of more than about 1.2 and an overall density of less than about 850 g / l. The substantially non-tacky particles can include inorganic fillers, builders, "substantially non-tacky surfactants" and other ingredients. Typically, the non-tacky particles will have a substantially low to no concentration (ie, less than about 10% on a weight basis) of tacky surfactants. The total amount of surfactants, including both tacky and non-tacky surfactants in the composition, is at least about 15% by weight thereof. With the optimally selected particle concentrations, particle densities, particle sizes and scale of respective particle sizes mentioned above, measured by geometric average and geometric standard deviation statistics, the composition unexpectedly exhibits a higher dispersion and dissolution in solutions of washing at low temperatures. A method for washing clothes is also provided, which comprises the steps of contacting soiled laundry with an effective amount of a detergent composition in accordance with the compositions described herein, in an aqueous wash solution.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The invention provides a detergent composition that exhibits improved dispersion and dissolution in aqueous wash solutions. It has now been found that by optimally selecting the physical properties of various particles contained in granular detergent compositions, dissolution can be improved. As previously mentioned, typical detergent formulations that dissolve in aqueous wash solutions form a highly viscous surfactant phase or paste that coats or otherwise "bridges" with other surfactant-containing particles to form "agglomerates" , finally causing a "grumo-gel" formation. As used herein, the phrase "individual particles" means particles, agglomerates or individual granules which can be identified by means of a scanning electron microscope as individual mass units. For each type of particulate component in a mixture, individual particles of that type have the same composition or a substantially similar composition regardless of whether the particles are in contact with other particles. For agglomerated components, the agglomerates themselves are considered as individual particles, and each individual particle may comprise a mixed material of smaller primary particles and binder compositions. As used herein, the phrase "average geometric particle diameter" means the average geometric mass diameter of a set of individual particles measured by any standard mass-based particle size measurement technique, such as dry sieving. As used herein, the phrase "standard geometric deviation" of a particle size distribution means the geometric space of the normal logarithmic function best suited to the aforementioned particle size data. As used herein, the phrase "builder" means any inorganic material that has a "builder" performance in the context of detergency, and specifically, an organic or inorganic material capable of removing the hardness of the water of the detergent. washing solutions. As used herein, the term "overall density" refers to the overall non-compressed powder density, measured by pouring an excess of powder sample through a funnel into a smooth metal container (e.g., a cylinder with a volume of 500 ml), removing the excess with a spatula from the top above the edge of the container, measure the remaining mass of powder, and divide the mass between the volume of the container.

As used herein, the term "substantially tackifying surfactants" refers to a surfactant or surfactant mixing system consisting primarily of surfactants that substantially contribute to the formation of grumo gel in low wash solutions. temperatures, including the general classes of alkyl benzene sulphonates, alkyl ethoxy sulfates and nonionic surfactants. As used herein, the phrase "substantially non-tacky surfactant" refers to a surfactant or surfactant mixing system consisting primarily of surfactants that do not substantially contribute to the formation of gel lumps in washing solutions. at low temperatures, such as straight chain alkyl sulfates with an average alkyl carbon chain length of at least 12. As used herein, all specifications of the level of the composition and the size distribution are made on an mass basis, unless otherwise indicated. In cases where the level is specified on a number basis, the calculations used to convert from a base to mass to number are contained in Example 3 described hereinafter. It has been found that "lump-gel formation" can be avoided by minimizing the "bridging" effect or the points of contact between particles that tend to be "sticky", such as particles containing surfactant systems consisting mainly of of substantially tacky surfactants. This is achieved by the present invention formulating the detergent composition with selectively decreased levels of particles containing surfactants, wherein the "level" is based on the total "fraction by number" of individual particles in the composition. Likewise, the particle size and its distribution space (i.e., scale of distribution) of the substantially sticky particles are optimally selected. An additional elimination of the "bridging" effect is achieved which causes undesired dissolution problems, increasing the level of particulate components that are typically not "sticky" and, therefore, do not easily lead to "bonding" by themselves. by bridges "particles among themselves forming agglomerates or lumps-gel. Again, the level of the non-sticky particles is based on the total number of individual particles in the detergent composition. The physical properties, such as the particle size and the distribution and density of the substantially non-tacky particles, are also optimally selected. It is to be understood that the "individual particles" containing surfactants or other ingredients such as inorganic builders may be in the form of mixed particles, spray-dried granules and / or agglomerates, depending on the general formulation desired and the density of the product. .

Although not intended to be limited by theory, it is thought that by selecting relatively large, relatively large sticky particles of relatively high density with moderate to high levels of surfactant in each individual particle, in combination with substantially non-sticky and relatively small particles, the effect "Bridging" can be greatly reduced since there are relatively few (or at least few) points of contact between so-called "sticky" particles containing surfactant. This, in turn, reduces lumping-gel formation, resulting in improved dispersion and dissolution of the detergent composition in aqueous wash solutions, especially in solutions at low temperatures. However, it should be understood that the physical properties of the detergent composition must be kept within reasonable limits to ensure that the typical attributes of the product of the detergent composition are maintained. For example, although a larger size of the sticky particle can help promote better dispersion, the particle size of the sticky particles should not be extremely large so that a non-ordinary amount of time is required before they dissolve in the aqueous wash solution. Similarly, the particle size of the substantially non-tacky particles should not be so small and have a density so low that the detergent composition is extremely "dusty". Finally, the balance between the largest substantially sticky particles and the smallest substantially non-tacky particles should be selected so as to avoid a significant segregation of the product in the box for detergent product before use.

As indicated above, the present invention provides an optimum selection of different physical properties to provide the desired improvement in dissolution performance. For that purpose, the geometric diameter of average particle size based on mass of the substantially sticky particles, is preferably from about 300 microns to about 700 microns, with a standard geometric deviation of less than about 1.8, more preferably of about 350 microns. at about 650 microns, with a standard geometric deviation of less than about 1.7, and more preferably from about 400 microns to about 600 microns, with a standard geometric deviation of less than about 1.6. Preferred compositions include substantially tacky particles having at least about 15%, more preferably about at least about 35%, and most preferably at least about 45%, by weight of the sticky particles, a substantially tacky surfactant. Although a wide variety of tacky surfactants is suitable for use in the detergent compositions of the invention, an especially preferred substantially tacky surfactant is a potassium salt of a surfactant selected from the group consisting of linear alkyl benzenes, alkyl ethoxy sulphates, and mixtures thereof. The average overall density of substantially sticky particles is preferably at least about 450 g / l, more preferably at least about 550 g / l, and most preferably at least about 650 g / l, preferably the geometric diameter of the average particle size of the substantially non-tacky particles, is preferably from about 200 microns to about 500 microns with a geometric standard deviation greater than about 1.2, more preferably from about 250 microns to about 450 microns with a larger geometric standard deviation of about 1.4, most preferably from about 300 microns to about 400 microns with a geometric standard deviation greater than about 1.6. Preferred compositions include inorganic particles containing builder having less than about 10%, more preferably less than about 5%, and most preferably less than about 1%, by weight of the non-tacky particles, of a substantially tacky surfactant . The average overall density of the non-tacky particles is preferably less than about 850 g / l, more preferably less than about 650 g / l, and most preferably less than about 500 g / l. Although a wide variety of inorganic builders are suitable for use in the substantially non-tacky particles of the invention, the especially preferred non-tacky particles comprise sodium or potassium salts selected from the group consisting of sodium chloride, sodium carbonate , sodium sulfate, tetrasodium pyrophosphate, trisodium pyrophosphate, disodium pyrophosphate, monosodium pyrophosphate, potassium chloride, potassium carbonate, potassium sulfate, tetrapotassium pyrophosphate, tripotassium pyrophosphate, dipotassium pyrophosphate, monopotassium pyrophosphate, and mixtures thereof. Additional dissolution increments are achieved when the composition comprises about 0. 05% to about 50% by weight of potassium, preferably from about 0.5% to about 30%, more preferably from about 1% to about 20% by weight, of potassium ions, regardless of the source from which the ions potassium derived. However, typically, the potassium ions useful herein are derived from potassium salts. Some of the non-limiting examples of the potassium salts useful herein are potassium salts of alkaline builders (e.g., potassium salt of carbonates, potassium salt of silicates), potassium salt of branched surfactants in the middle region of its chain, and mixtures thereof. Of the potassium salts, inorganic potassium salts are preferred, and are more preferably selected from the group consisting of potassium chloride (KCI), potassium carbonate (K2CO3), potassium sulfate (K SO), and mixtures thereof. . These are commercially available. Potassium carbonate is more preferred. Inorganic potassium salts can include tetrapotassium pyrophosphate dehydrated (preferably) or hydrated (K4P2? 7 is preferred), tripotassium pyrophosphate (HK3P207), dipotassium pyrophosphate (H2K2P2O7) and monopotassium pyrophosphate (H3KP2O7). Of the hydrates, those which are stable at about 48.9 ° C are preferred. Other potassium salts for use herein are pentapotassium tripolyphosphate dehydrated (preferably) or hydrated (K5P3O10), tetrapotassium tripolyphosphate (K5P3O10), tetrapotassium tripolyphosphate (HF PsO-io), tripotassium tripolyphosphate (H2K3P3O10), dipotassium tripolyphosphate (H3K2P3O10) and monopotassium tripolyphosphate (H KP3O10); potassium hydroxide (KOH); potassium silicate; and potassium neutralized surfactant, such as compounds of branched surfactant in the middle region of its chain and longer chain of potassium alkyl, linear potassium alkylbenzenesulfonate, potassium alkyl sulfate, and / or potassium alkyl polyethoxylate. Also suitable for use herein are the film forming polymer salts, as described in the U.S.A. No. 4,379,080, Murphy, issued April 5, 1983, column 8, line 44 to column 10, line 37, incorporated herein by reference, which are partially or fully neutralized with potassium. Particularly preferred are the potassium salts of acrylamide and acrylate copolymers having a molecular weight between about 4,000 and 20,000. In addition, the combination of both types of the particles mentioned above, must yield a general particle size distribution that is less than about 5% fine particles, and less than about 5% abnormally sized particles, where the fine boundary it is defined at 150 microns and the limit of abnormal size is defined at 1180 microns.

Sticky Detersive Surfactants Non-limiting examples of the preferred substantially tackifying surfactants include anionic surfactants which include the conventional CHC-IS alkylbenzenesulfonates, branched chain random C10-C20 alkyl sulphates, the secondary alkyl sulfates (2.3) of C10 -C18 of the formulas CH3 (CH2)? (CHOS? 3"M +) CH3 and CH3 (CH2)? (CHOS? 3" M +) CH2CH3, where x and (y + 1) are integers of at least about 7, preferably at least about 9, and M is a cation of solubilization in water, especially sodium or potassium, unsaturated sulfates such as oleyl sulfate and the alkyl alkoxysulfates of C- | 0-C? s ("AExS"; especially EO ethoxysulfates) 1-7). Optionally, other examples of useful surfactants include C 1 io-C-is alkyl alkoxycarboxylate (especially the EO 1-5 ethoxycarboxylates), the C 1 or C 8 glycerol ethers, the C 10 -C 18 alkyl polyglycosides and their polyglucosides. sulfates, and alpha-sulfonated fatty acid esters of C12-C? s. If desired, conventional non-ionic and amphoteric surfactants, such as C? 2-C? 8 alkyl ethoxylates, including the so-called alkylphenol, C alco-C-12 alkoxylates and alkyl ethoxylates, may also be included in the general compositions. narrow peak (especially mixed ethoxylates and ethoxy / propoxy), C2-C8 betaines and sulfobetaines ("sultaines"), C10-C18 amine oxides, and the like. N-alkyl polyhydroxylic acid amides of C 10 -C 18 can also be used. Typical examples include the C12-C18 N-methylglucamides. See WO 9,206,154. Other surfactants derived from sugar include the fatty acid amides N-alkoxy polyhydric oxides, such as C10-C18 N- (3-methoxypropyl) glucamide.

The N-propyl to N-exyl glucamides of C? 2-C-| 8 can be used for low foaming. You can also use conventional soaps C? O-C2o- If high foaming is desired, branched-chain C10-C16 soaps can be used. Mixtures of anionic and nonionic surfactants are especially useful. Other conventional useful surfactants are cited in standard texts.

Inorganic builders A variety of inorganic builders are suitable for use herein, and include aluminosilicates, stratified crystalline silicates, MAP zeolites, citrates, amorphous silicates, sodium carbonates, and mixtures thereof. The aluminosilicate ion exchange materials used herein as a builder preferably have a high calcium ion exchange capacity and a high exchange rate. Without wishing it to be limited by theory, it is thought that said high calcium ion exchange rate and said high exchange capacity are a function of several interrelated factors that derive from the method by which the aluminosilicate ion exchange material is produced. . In this regard, the aluminosilicate ion exchange materials used herein are preferably produced in accordance with Corkill et al, U.S. Pat. No. 4,605,509 (Procter &Gamble), the disclosure of which is incorporated herein by reference. Preferably, the aluminosilicate ion exchange material is in the "sodium" form, since the potassium and hydrogen forms of the present aluminosilicate do not exhibit the high ion exchange capacity and the high exchange capacity provided by the sodium form . In addition, the aluminosilicate ion exchange material is preferably in excess dried form to facilitate the production of crisp detergent agglomerates as described herein. The aluminosilicate ion exchange materials used herein preferably have particle size diameters that optimize their effectiveness as builders. The term "particle size diameter", as used herein, represents the average particle size diameter of a given aluminosate ion exchange material determined by conventional analytical techniques, such as microscopic determination and with scanning electron microscopy (SEM). The preferred particle size diameter of the aluminosate is from about 0.1 microns to about 10 microns, more preferably from about 0.5 microns to about 9 microns.

More preferably, the particle size diameter is from about 1 micron to about 8 microns. Preferably, the aluminosilicate ion exchange material has the formula Naz [(AIO2) z- (SiO2) y] xH2O where z and e are integers of at least 6, the molar ratio of z: y is about 1 to about 5, and x is from about 10 to about 264. More preferably, the aluminosilicate has the formula Na 12 [(Al 2) i 2 - (SiO 2) 12] xH 2 O wherein x is from about 20 to about 30, preferably Approximately 27. These preferred aluminosilicates are commercially available, for example, under the designations of Zeolite A, Zeolite B and Zeolite X. Alternatively, naturally occurring or synthetically derived aluminosilicate ion exchange materials suitable for use in the present, can be obtained as described in Krummel et al, US patent No. 3,985,669, the disclosure of which is incorporated herein by reference. The aluminosilicates used herein are further characterized by their ion exchange capacity which is at least about 200 mg hardness equivalent of CaCO3 / g, calculated on an anhydrous basis, and which is preferably on a scale of about 300 to 352 mg hardness equivalents of CaCO3 / g. Additionally, the present aluminosilicate ion exchange materials are further characterized by their calcium ion exchange capacity which is at least about 129.58 mg.

Ca ++ / 3,785 l / minute / g / 3,785 I, and more preferably on a scale of approximately 129.58 mg of Ca ++ / 3,785 l / minute / g / 3,785 I to approximately 388.74 mg of Ca ++ / 3,785 l / minute / g / 3,785 I Compared with amorphous sodium silicates, the crystalline layered sodium silicates exhibit a clearly increased calcium and magnesium ion exchange capacity.

In addition, stratified sodium silicates prefer magnesium ions over calcium ions, a feature necessary to ensure that substantially all of the "hardness" is removed from the wash water. However, these crystalline layered sodium silicates are generally more expensive than amorphous silicates, as well as other detergency builders. Accordingly, in order to provide an economically convenient laundry detergent, the proportion of crystalline layered sodium silicates must be judiciously determined. The crystalline layered sodium silicates suitable for use herein have preferably the formula NaMS.sub.x0.sub.2 x + y- and H 2 O wherein M is sodium or hydrogen, x is from about 1.9 to about 4, and is from about 0 to about 20. More preferably, the crystalline layered sodium silicate has the formula NaMSi 2 O 5 and H 2 O wherein M is sodium or hydrogen, and is about 0 . These and other crystalline layered sodium silicates are described in Corkill et al, patent of E.U.A. No. 4,605,509, previously incorporated herein by reference. Attached ingredients include other detergency builders, bleaches, bleach activators, foam enhancers, or foam suppressors, anti-corrosion and anti-rust agents, soil suspending agents, soil release agents, germicides, pH adjusting agents , alkalinity sources without detergency builder, chelating agents, smectite clays, enzymes, enzyme stabilization agents and perfumes. See the patent of E.U.A. 3,936,537, issued on February 3, 1976 to Baskerville. Jr. et al., Incorporated herein by reference. Water-soluble phosphorus-free organic builder builders useful herein include the various alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates and polyhydroxysulfonates. Examples of polyacetate and polycarboxylate builders are sodium salts, potassium, lithium, ammonium and substituted ammonium of ethylenediaminetetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid, melific acid, benzene polycarboxylic acids and citric acid. Polycarboxylate polymer detergent builders are described in the U.S. 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 alipc carboxylic acids such as maleic acid, taconic 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 described below, but only if they are in intimate admixture with the non-soap anionic surfactant. Other polycarboxylates suitable for use herein are the polyacetal carboxylates described in the U.S.A. 4,144,226, issued March 13, 1979 to Crutchfield et al, and the patent of E.U.A. 4,246,495, issued March 27, 1979 to Crutchfield et al, which are incorporated herein by reference. These polyacetal carboxylates can be prepared by bringing together under polymerization conditions, a glyoxylic acid ester and a polymerization initiator. The resulting ester of polyacetal carboxylate 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 ether carboxylate builder compositions comprising a combination of tartrate monosuccinate and tartrate disuccinate described in the U.S.A. 4,663,071, Bush et al., Issued May 5, 1987, the disclosure of which is incorporated herein by reference.

Bleaching agents and bleach activators are described in the U.S. patent. 4,412,934, Chung et al., Issued November 1, 1983, and in the U.S. patent. 4,483,781, Hartman, issued November 20, 1984, which are incorporated herein by reference. Chelating agents are also described in the patent of E.U.A. 4,663,071, Bush et al., From column 17, line 54 to column 18, line 68, incorporated herein by reference. Foam modifiers are also optional ingredients, and are described in the 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. Smectite clays suitable for use herein are described in the US patent. 4,762,645, Tucker et al, issued August 9, 1988, column 6, line 3 to column 7, line 24, incorporated herein by reference. Other detergency builders suitable for use herein are listed in the Baskerville patent, column 13, line 54 to column 16, line 16, and in the U.S. patent. 4,663,071, Bush et al, issued May 5, 1987, both incorporated herein by reference. To make the present invention better understood, reference is made to the following examples, which are intended to be illustrative only and not limiting of the scope thereof.

EXAMPLES l-ll The following examples illustrate detergent compositions within the scope of the invention, as well as a control example for illustrating a composition outside the scope thereof. The relative proportions and specific detergent ingredients are shown below, wherein "LAS" means linear C12-14 alkylbenzene sulfonate surfactant, "AS" means Cu-15 alkyl sulfate surfactant, "AES" means a surfactant of alkyl ethoxy sulfate (EO = 3) of C-14-15, and "65/25/10" is a percentage of the weight ratio.

The spray-dried granules are prepared using a standard spray-drying process in which the ingredients are mixed to form a suspension which is then sprinkled in a spray-drying tower to form spray-dried granules. The detergent agglomerates are prepared by combining the surfactant paste and other ingredients in one or more mixers, until agglomerates of detergent are formed. The mixed components are simply added to the granules and agglomerates if it is a dry ingredient, and they are sprinkled if they are in liquid form. The different physical properties of the compositions are shown below: The control composition is a typical detergent composition having approximately 90% substantially tackified particles (more agglomerated spray dried granules) based on the total number of particles in the composition. As a result, the control composition has a high number of contact points of the sticky particles which make it susceptible to "bridging" effects., finally causing the formation of lumps-gel. In contrast, the compositions of Examples I and II contain only tacky surfactants in the higher density agglomerates and, therefore, have approximately 30% or less of sticky particles, based on the total number of particles in the composition. Unexpectedly, examples I and II have a degree of ROOA ("reverse addition order") much better, and experience less residual mass in the washer and in the garments subsequent to standard washing operations.

EXAMPLE III Calculation of the percentage of the number of particles based on the total number of individual particles in a detergent composition This example illustrates one of the many ways by which the percentage of the number of particles of sticky particles and / or non-tacky particles can be determined with respect to the total number of individual particles in the composition. The variables describe the physical characteristics of each component of the mixture within it: w weight of component i in the composition; d) average geometric particle size on mass basis; s the geometric standard deviation of the particle size distribution on a mass basis; p¡ global density. To quantify the potential to form bridges between particles, it is desired to consider the distribution of particles in number in the mixture. On the other hand, it is recognized that virtually all bulk powder manufacturing operations operate on a mass basis. Therefore, it is desired to use the fractions of particulate components in mass as a basis for defining the mixture, and converting from mass to base in number. First, the fraction by weight of each component of the mixture, Wj, is converted to the total volume fraction of the mixture, Vj. This is done using an intermediate volume, v, and the component global density, p (equation A1). The component volumes are normalized to total fractions of the volume of the mixture (equation A2). Wl Vi = -; weight to volume conversion (A1) pi VÍF = V -; volume fraction of component i in the mixture (A2) and vl A numerical method is used to convert the mass-based distribution to a base in number. For each component (i), consider a scale of class values of size n (j), xy, where: log (x¡?) = Log (d¡) -3xlog (s¡); Fine limit (A3) log (x¡n) = log (d¡) + 3xlog (if); Thick limit (A4) and the intermediate values (j = 2 to n-1) are distributed at equal intervals of? log (x), where? log (x) = [log (x¡n) -log (x¡?)] / 30 . The normal-logarithmic distribution describes a differential mass fraction by logarithm (size), yj, as follows (equation A5). and "logarithms of the normal distribution function (A5) To convert mass from population to number, we calculate a population by number, zj, of particles (i) associated with each defined mass fraction (equation A6) and a normalized population, Zy (equation A7) ZÜ = y¡j * \ xij) 3 > population of particles i in size classes p) j (A6) The number density, n, of the component particles i is defined as the population of component particles (i) per unit volume of mixture; this is the product of the volume fraction and the sum of the populations (i) over all the size classes, j (equation A7). The fraction in number, N, of each component is calculated by normalizing the population in number over all the components in the mixture (equation A8). The percentage in number, is simply the fraction in number times 100. n¡ = V¡ •? z¡J.; density in number, or population of the particle i per unit volume of mixture, summed over all size classes, j (A7) N: fraction in number of particles of component i in the complete mixture (A8) Having thus described the invention in detail, it will be obvious to those skilled in the art that various changes can be made without departing from the scope of the invention, therefore the invention should not be considered to be limited to what is described in specification.

Claims (10)

NOVELTY OF THE INVENTION CLAIMS

1. - A detergent composition, characterized in that it comprises: (a) from about 1% to about 50%, based on the total number of individual particles in said composition, of substantially tacky particles containing at least about 15%, by weight of said sticky particles, of a substantially tacky surfactant, wherein said sticky particles have an average geometric particle size of about 300 microns to about 700 microns, with a geometric standard deviation of less than about 1.8, and an overall density of at least about 450g / l; and (b) more than about 35%, based on the total number of individual particles in said composition, of substantially non-tacky particles having an average geometric particle size of about 200 microns to about 500 microns, with one standard deviation geometric greater than about 1.2 and an overall density less than about 850g / l; wherein the total amount of detersive surfactant in said composition is at least about 15%, by weight of said composition.

2. The detergent composition according to claim 1, further characterized in that said sticky particles contain at least about 35%, by weight of said sticky particles, of said tacky surfactant.

3. The detergent composition according to claim 1, further characterized in that said sticky particles contain at least about 45%, by weight said sticky particles, of said tacky surfactant.

4. The detergent composition according to claim 1, further characterized in that said composition comprises from about 0.05% to about 50% by weight of potassium ions.

5. The detergent composition according to claim 1, further characterized in that the overall density of said sticky particles is at least about 550g / l, and the overall density of said non-tacky particles is less than about 650g / l.

6. The detergent composition according to claim 1, further characterized in that the overall density of said sticky particles is at least about 650g / l, and the overall density of said non-tacky particles is less than about 500g / l.

7. The detergent composition according to claim 1, further characterized in that said non-tacky particles comprise a potassium salt selected from the group consisting of potassium chloride, potassium carbonate, potassium sulfate, tetrapotassium pyrophosphate, tripotassium pyrophosphate, pyrophosphate dipotassium, monopotassium pyrophosphate, and mixtures thereof.

8. The detergent composition according to claim 1, further characterized in that said sticky particles have an average geometric particle size of about 350 microns to about 650 microns, with a geometric standard deviation of less than about 1.7.

9. The detergent composition according to claim 1, further characterized in that said non-tacky particles have an average geometric particle size of about 250 microns to about 450 microns, with a geometric standard deviation greater than about 1.4.

10. A method for washing clothes, characterized in that it comprises the steps of contacting said clothes with an effective amount of a detergent composition according to claim 1, in an aqueous washing solution.