MXPA00000593A - Process for making a low density detergent composition by controlled agglomeration in a fluid bed dryer - Google Patents

Abstract

A process for producing a low density detergent composition is provided. The process involves:(a) agglomerating a detergent surfactant paste or precursor thereof and dry starting detergent material in a frist high speed mixer to obtain detergent agglomerates;(b) mixing the detergent agglomerates in a second high speed mixer to obtain built-up agglomerates;and (c) feeding the built-up agglomerates and a binder into a fluid bed dryer to form detergent agglomerates having a density in a range from about 300 g/l to about 550 g/l, the fluid bed dryer being operated at a Stokes Number of less than about 1, wherein Stokes Number=8&rgr;&ngr;d/9&mgr;,&rgr;is the apparent particle density of the built-up agglomerates,$(g)n is the excess velocity of the built-up agglomerates, d is the mean particle diameter of the built-up agglomerates and&mgr;is the viscosity of the binder.

Description

PROCEDURE TO MAKE A COMPOSITION OF LOW-DENSITY DETERGENT BY CONTROLLED AGGLOMERATION IN A FLAT BED DRYER FIELD OF THE INVENTION The present invention relates generally to a process for producing a low density detergent composition. More particularly, the invention is directed to a method during which produce low density detergent agglomerates, feeding a surfactant paste or a liquid acid precursor of anionic surfactant and dry starting detergent material sequentially to two high speed mixers, followed by the fluid bed dryer in which agglomeration is controlled for produce the low density detergent composition that is you want. The low density detergent composition produced by the process can be sold commercially as a conventional non-compact detergent composition or used as a mixed admixture in a "low dosage" compact detergent product.

BACKGROUND OF THE INVENTION Recently, there has been considerable interest within the detergent industry for laundry detergents that are "compact" and have ? > ^ $ k & therefore low dosage volumes. To facilitate the production of these so-called low dosage detergents, many attempts have been made to produce high density global detergents, for example a density of 600 g / l or higher. Low dosage detergents are currently in high demand, as they conserve resources and can be sold in small packages that are more convenient for consumers. However, the degree to which modern detergent products need to be "compact" in nature remains uncertain. Indeed, many consumers, especially in developing countries, continue to prefer higher dosage levels in their respective laundry operations. Accordingly, there is a need in the art to produce modern detergent compositions with flexibility in the essential density of the final composition. Generally, there are two fundamental types of processes by which granules or detergent powders are prepared. The first type of process involves the spray drying of an aqueous detergent suspension in a spray-drying tower to produce highly porous detergent granules. In the second type of process, the various detergent components are mixed dry, after which they are agglomerated with a binder such as a nonionic or anionic surfactant. In both procedures, the most important factors that govern the density of the new detergents resulting are density, porosity and surface area, the shape of the various starting materials and their respective chemical composition. However, these parameters can only be varied within a limited range. Thus, the flexibility of the substantial overall density can be achieved, only with additional process steps that lead to the lower density of the detergent granules. There have been many attempts in the art to provide 5 methods that increase the density of the detergent granules or powders. Particular attention has been paid to the densification of spray-dried granules with subsequent tower treatment. For example, an attempt involves an intermittent procedure in which spray-dried detergent powders or granulates containing tripolyphosphate from the base are densified and spheronized. sodium and sodium sulfate, in a Marumerizer®. This apparatus comprises a rough, substantially horizontal pivotable board, located within the base thereof of a smooth, substantially vertical wall cylinder. This method, however, is essentially an intermittent process and is therefore less suitable for the large-scale production of detergent powders. Plus Recently, other attempts have been made to provide continuous procedures to increase the density of the detergent granules dried "later in tower" or by spray. Typically, such procedures require a first apparatus that pulverizes or crushes the granules and a second apparatus that increases the density of the granules sprayed by agglomeration.

Although these methods achieve the desired increase in density, by treating the granules dried "later in tower" by sprinkling, they do not provide another method that has the flexibility to provide lower density granules.

In addition, all the aforementioned processes are primarily directed to densify or otherwise treat the spray-dried granules. At present, the radioactive quantities and the types of materials subjected to the spray drying processes in the production of detergent granules have been limited. For example, it has been difficult to achieve high levels of surfactant in the resulting detergent composition, a feature that facilitates the production of detergents more efficiently. In addition, there must be a process by which detergent compositions can be produced without having the limitations imposed by conventional spray-drying techniques. To that end, the technique is also replete with procedural exposures involving binder detergent compositions. For example, attempts have been made to agglomerate builders by mixing zeolite and / or layered silicates from a mixer to form free flowing agglomerates. Although such attempts suggest that its process can be used to produce detergent agglomerates, it does not provide a mechanism by which conventional starting detergent materials can be effectively agglomerated in the form of surfactant pastes or precursors thereof, liquids and dry materials, to form agglomerated, free-flowing, brittle detergents that have low densities rather than high densities. In the past, the expectations of producing such low density agglomerates involved an unconventional detergent ingredient that is typically expensive, thus increasing the cost of the product & * K ** detergent. One such example of this involves a process for agglomerating inorganic double salts such as burkeite to produce the desired low density agglomerates. According to the above, there remains a need in the art to have a process for producing a low density detergent composition directly with starting detergent ingredients without the need for relatively expensive specialty ingredients. In addition, there remains a need for such a process that is more efficient, flexible and economical to facilitate the large-scale production of detergents with either low or high dosage levels.

PREVIOUS TECHNIQUE The following references are directed to densify the spray-dried granule 5: Appel et al., U.S. Pat. No. 5,133,924 (Lever); Bortolotti et al., Patent of E.U.A. No. 5,160,657 (Lever); Jonhson et al., British Patent No. 1, 517,713 (Unilever); and Curtis, European patent application 451, 894. The following references are directed to the production of detergents by agglomeration: Beerse et al., patent of E.U.A. No. 5,108,646 (Procter &Gamble); application of Capeci et al., patent of E. U. A. No. 5,366,652 (Procter &Gamble); Hollingsworth et al., European patent application 351, 937 (Unilever); and Swatling et al., U.S. Patent. No. 5,205,958. the following references are directed to non-organic double salts: Evans and others, patent of '^^^^^ & tí? tí ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ No 4,820,441 (Lever); Evans et al., U.S. Patent. No. 4,818,424 (Lever); Atkinson et al., Patent of E.U.A. No. 4,900,466 (Lever); France et al., Patent of E.U.A. No. 5,576,285 (Procter &Gamble); and Dhalewadika et al., PCT WO 96/04359 (Unilever).

BRIEF DESCRIPTION OF THE INVENTION The present invention meets the needs mentioned above in the art, by providing a process that produces a low density detergent composition (less than about 600g / l) directly with starting ingredients without the need for expensive specialty ingredients, such as inorganic double salts. . The process does not use the conventional spray drying towers commonly used and is therefore more efficient, economical and flexible with respect to the variety of detergent compositions that may be produced in the process. In addition, the process is more adaptable to environmental issues because it does not use spray-drying towers that typically emit particulate materials and volatile organic compounds into the atmosphere. The process essentially includes two high speed mixers, followed by a fluid bed which is operated in such a way that the Stokes number for the coalescence of the agglomerates is within the selected range. This results in the formation of the desired low density detergent composition.

As used herein, the term "agglomerates" refers to particles that are formed by agglomerating granules or detergent particles that typically have a smaller average particle size than that of the agglomerates that are formed. As used herein, the phrase "average particle size" means the diameter value of the particle size and below which 50% of the particles have a larger particle size and less than 50% of the particle size. the particles have a smaller particle size. As used herein, "excess velocity" means the amount of velocity of the particles or agglomerates greater than the minimum fluidization rate of said agglomerated particles or said particles, wherein the minimum fluidizing velocity is the minimum speed that is needed to move said particles that can be calculated, for example, by means of the equation of Wen and Yu. All percentages used herein are expressed as "percent by weight" on an anhydrous basis, unless stated otherwise. They are incorporated in present all documents cited herein, by reference in their entirety. According to one aspect of the invention, a method for preparing low density detergent agglomerates is provided. The procedure comprises the steps of: (a) agglomerating a surfactant paste to detergent or precursor thereof and dry starting detergent material in a first high speed mixer to obtain agglomerates; (b) mixing the detergent agglomerates in a second high speed mixer to obtain shaped agglomerates; (c) add a second liquid acid precursor ? _ ^ n_M_w_M_M _ «_ tt _______« _ l_tf_áítt_ ^ of an anionic surfactant to the second high-speed mixer; and (d) feeding the shaped agglomerates and a binder to a fluid bed dryer to form low density detergent agglomerates having a density in the range of about 300 g / l to about 550 g / l, the fluid bed drier operating with a number of Stokes in a range from about 0.1 to about 0.5, where the number of Stokes = 8? vd / 9μ, p is apparent particle density of the shaped agglomerates, v is the excess velocity of the formed agglomerates, d is the average particle diameter of the shaped agglomerates and μ is the viscosity of the binder. Detergent products made in accordance with any of the methods of the process described herein are also provided. According to the above, it is an object of the invention to provide a process for producing a low density detergent composition directly with starting detergent ingredients, which does not include relatively expensive specialty ingredients. It is also an object of the invention to provide such a procedure that is more efficient, flexible and economical, so as to facilitate the large-scale production of detergents with both low and high dosage levels. These and other objects, features and concomitant advantages of the present invention will become more apparent to those skilled in the art with a reading of the following detailed description of the preferred embodiment and the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED MODALITY The present invention is directed to a process in which low density agglomerates are produced by selectively controlling the fluid bed dryer operation in the process as detailed hereinafter. The process forms low density, free-flowing detergent agglomerates, which they can be used alone as the detergent product or as a mixture addition with conventional spray-dried detergent granules and / or high density detergent agglomerates in a final commercial detergent product. It should be understood that the process described herein can be operated continuously or intermittently depending on the particular desired application. A major advantage of the present method is that it uses equipment that can be used differently from the present process parameters to obtain high density detergent compositions. In this way, a single commercial facility for large-scale detergent manufacture can be manufactured to produce high or low density detergent compositions, depending on the local demand of consumers and their inevitable fluctuations between compact and non-compact detergent products.

Procedure In the first step of the process, a surfactant detergent or propellant paste is introduced and agglomerated in a high-speed mixer.

^ Uü ________? of the same as discussed in more detail hereinbelow and dry starting detergent material having a selected average starting size. Unlike previous procedures in this area, the dry starting material may include only those relatively inexpensive detergent materials, which are typically used in modern granular detergent products. Such ingredients include, but are not limited to, detergency builders, fillers, dry surfactants, and flow aid materials. Preferably, the detergency builder includes aluminosilicates, crystalline layered silicates, phosphates, carbonates and mixtures thereof which is the essential dry starting detergent ingredient within the scope of the present process. Relatively expensive materials such as burqueite (Na2SO NA2C03) and the various silicas are not necessary to achieve the desired low density agglomerates produced by the process. Rather, it has been found that by judiciously controlling the formation of particles by means of operating parameters of the process equipment, agglomerates having a high degree of porosity of "nparticle" or "non-granule" or "Non-aggregated" and are therefore low density. The terms "nparticle" or "intragranule" or "intraglomerate" are used herein to refer to the porosity or empty space within the conformed shaped agglomerates that occur at any stage of the process. In the first step of the process, the average particle size of the dry detergent material is preferably in the range of about 5 microns to about 70 microns, more. The high-speed mixer can be any of a variety of commercially available mixers, such as a 5 Lódige CB 30 mixer or a similar brand mixer. These types of mixers essentially consist of a horizontal and hollow static cylinder having a centrally mounted rotating shaft around which are attached several shovel-shaped or rod-shaped blades. Preferably, the shaft rotates at a speed of about 100 rpm to about 2500 rpm, more preferably from about 300 rpm to about 1600 rpm. Preferably, the average residence time of the detergent ingredients in the high-speed mixer is preferably in the range of from about 2 seconds to about 45 seconds and most preferably from about 5 seconds to about 15 seconds. It is measured conveniently this type of average permanence, dividing the weight of the mixer in stable state between the flow of yield (kg / hr). Another suitable mixer is any of the various Flexomix models obtainable from Schugi (The Netherlands) which are vertically placed high speed mixers. This type of mixer is preferably operated at the same speeds and average dwell times as indicated above with respect to Lódige CB mixers. In a preferred embodiment of the process invention, a liquid acid precursor of an anionic surfactant is introduced with the dry starting detergent material that includes at least one neutralizing agent such as sodium carbonate. The preferred liquid acid surfactant precursor is linear alkylbenzene sulfosonate ("HLAS") surfactant of Cn-iß, although any acid precursor of anionic surfactant can be used in the process. A more preferred embodiment involves feeding a liquid acid precursor of C12-14 linear alkylbenzene sulfosonate surfactant with an alkyl-ethoxylated sulfate ("AS") surfactant C-? O-18 to the first high speed mixer, preferably at a weight ratio of about 5: 1 to about 1: 5 and most preferably in a range of about 1: 1 to about 3: 1 (HLAS: AS). The result of such mixing is a "dry neutralization" reaction between the HLAS and the sodium carbonate incorporated in the dry starting detergent material, all of which form agglomerates. In high-speed mixers, the detergent agglomerates are made by transforming the particles into lightweight or "hollow" agglomerated particles, of low density, which have a high degree of particle porosity (ie, large voids within the shaped agglomerates) . The rate of particle size growth can be controlled in a variety of ways including, but not limited to, the variation in dwell time, the temperature and speed of the mixing tool of the mixer, the control of the amount of liquid or binder introduced to the mixer. In this way, the starting detergent material of smaller particle size is gradually formed in a controlled manner, so that the agglomerates have a high degree of intraparticle porosity, thus resulting in a low density detergent. Expressed differently, the smaller detergent starting material is "gummed" or "adhered", such that there is a high degree of intraparticle porosity. In the second step of the process, the agglomerates are introduced into detergents formed in the first step to a second high speed mixer which may be the same unit of equipment used in the first step or a different type of high speed mixer. By For example, a Lódige CB mixer can be used in the first step, while a Schugi mixer can be used in the second step. In this process step, agglomerates having an average particle size as previously indicated in a controlled manner are mixed and shaped in such a way that the detergent agglomerates have a particle size. medium of about 140 microns about 350 microns, more preferably about 160 microns about 220 microns and most preferably about 170 microns about 200 microns. As the first step of the procedure, the particulate porosity of the particles is increased, "adhering", to each other particles of smaller size with high degree of porosity between the starting particles that have been formed. Optionally, a binder can be added to facilitate the formation of the glazed agglomerates in this step. Typical binders include sodium silicate ^ _ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ionic texioantive agent such as HLAS, nonionic texioantive agent, polycyclic and mixtures thereof. The next step of the process is to introduce the shaped agglomerates (those agglomerates leaving the second mixer) to a mixture of the fluid bed in which the agglomerates are dried and agglomerated in a selectively controlled manner. In this process step, the fluid bed dryer is operated with a number of Stokes that is less than about 1, more preferably in the range of about 0.1, about 0.5, more preferably even about 0.2 about 0.4. The number of stokes of the particles for the coalition of the agglomerates is a known parameter to describe the degree of mixing or agglomeration that occurs to the particles in a unit of equipment (see Ennis et al, "A microlevel-basrd characterization of granulation phenomena" , Powder Technology, 65 (1991)). The number of Stokes = 8pvd / 9μ, where p is the apparent particle density of the shaped agglomerates (calculated from the global density of the formed agglomerates assuming an interparticle porosity of 0.4), v is the excess velocity of the shaped agglomerates, d is the average particle diameter of the shaped agglomerates and μ is the viscosity of the binder. Preferred embodinents of the invention of the process: p is in a range of about 800 g / l about 1300 g / l, more preferably about 850 g / l about 1100 g / l; v. it is from a range of about 0.1 m / s to about 2 m / s, preferably from about 0.3 m / s to about 1 m / s; d is approximately 50 microns approximately 2000 microns, preferably approximately 100 microns approximately 700 microns; and μ is about 10 cps about 500 cps, preferably about 50 cps about 300 cps. The density of the agglomerates formed is approximately 300 g / l approximately 550 g / l, more preferably and approximately 500 g / l and more preferably still and approximately 400 g / l approximately 480 g / l. All these densities are generally lower than the typical detergent decompositions formed of dense agglomerates achieving very typical pressure drying. Preferably, they are maintained at the temperature of the dryer of the fluid bed in a range of about 90 ° C at about 200 ° C, so that the formation of the desired agglomerates is enhanced. As with the first and second steps of the process, the agglomerates of smaller sizes are formed into larger sized particles having a high degree of intraparticle porosity. The degree of intraparticle porosity is preferably about 20% about 40%, and most preferably about 25% about 35%. The intraparticle porosity can be measured conveniently by typical mercury porosimetry tests. Preferably, a binder as described above is added during this step, to enhance the formation of the desired agglomerates. A particularly preferred binder is liquid sodium silicate. The process may involve adding the binder to both the second high-speed mixer and the fluid bed dryer, as is actually established, at any of these locations. It is also considered advantageous to add the binder simultaneously from more than one location of 5 one more steps of the process. For example, liquid silicate can be added in two locations in the dryer of the fluid bed, in the entrance or near door and in the exit door or fence. Also, the average diameter of the binder shell is approximately 20 microns approximately 150 microns, a parameter that enhances the formation of the agglomerates that are desired.

In addition, in this regard, the ratio of the average diameter of the binder to the particle diameter of the shaped agglomerate (leaving the second high-speed mixer) is preferably about 0.1 about 0.6. Other optional steps contemplated by the present procedure includes sifting the detergent agglomerates of larger size in a screening apparatus which can take a variety of forms including, but not being devoted to them, they are also conventional chosen for the desired particle size of the detergent product determined. Other optional steps include the conditioning of the detergent agglomerates, by subjecting the agglomerates to further drying and / or cooling by means of the apparatus discussed previously. Another optional step of the present process entails finishing and the resulting detergent agglomerates by a variety of processes including the expression and / or addition in admixture of other conventional detergent ingredients. For example, in finishing steps it encompasses the expression of perfumes, brighteners and enzymes on the finished agglomerates to provide a more complete detergent composition. Such procedures and ingredients are well known in the art.

Detergent surfactant paste or precursor The liquid acid precursor of aionic surfactant is used in the first step of the first process and, in optional embodiments, as a liquid binder in the second and / or third and third step of the process. That precursor has been liquid will typically have a viscosity measured at 30 ° C approximately 500 cps approximately 5,000 cps. The liquid acid is a precursor for the aionic deactivating agents described in more detail subsequently not present. A detergent surfactant paste and preferably in the form of an aqueous viscous paste can also be used in the process, although other forms are also contemplated in the invention. This so-called viscous surfactant has a viscosity of about 5000 cps about 100,000 cps, more preferably about 10,000 cps, about 80,000 cps and contains at least 10% water, more preferably at least about 20% water. The viscosity is measured at 70 ° C and at cutting speeds of about 10 to 100 seconds 1. Furthermore, in the surfactant paste, if used, it preferably comprises a detersive surfactant in the amounts specified above and the water of the remainder and other ingredients conventional detergents. The surfactant itself is selected in the viscous surfactant paste, preferably between the anionic, nonionic, zwitterionic, ampholytic and cationic classes, and compatible mixtures thereof. Surfactants useful herein are described in U.S. Patent 3,664,961, Norris, issued May 23, 1972 and in U.S. Patent 3,919,678, Laughiin et al., Issued on May 30, 1972. December 1975, both of which were incorporated herein by reference. Useful cationic surfactants that are included are also those described in US Patent 4.22,905, Cockrell, issued September 16, 1980 and US Patent 4,239,659, Murphy, issued December 16, 1980, both of which are incorporated by reference in their entirety. incorporated herein by reference. Of the surfactants, anionics and nonionics are preferred and anionics are preferred above all. Some non-limiting examples of the preferred anionic surfactants useful in the surfactant paste, or from which the liquid acid precursor described herein derives, include the alkylbenzene sulfates ("LAS") of Cu-Cie, the alkyl sulfates ("AS") ), C10 -C20 branched and random chain, the secondary alkyl sulphates (2.3) of C10 C? 8 of the formula CH3 (CH2) x (CHOSO3-M +) CH3 and CH3 (CH2) and (CHOSO3"M +) CH2CH3 where xy (y + 1) are integers of at least about 7, preferably at least about 9, and M is a water solubilizing cation 510, especially sodium, sulfates and saturates such as oleyl sulfate, and the alkyl alkoxysulfates of C-io C-ia ("AEXS", especially the ethoxysulfates of EO 1-7).

Optionally, other exemplary surface active agents useful in the paste of the invention include the C 10 -C 18 alkylalkoxycarboxylates (especially the EO 1-5 ethoxycarboxylates), the glycerol ethers of C-io-C-is, the alkyl polyglycosides of C? 0-C? 8 and its corresponding sulfated polyglycosides, and ethers of alpha-sulfonated fatty acids of C? 2-C? S. Conventional non-ionic and amphoteric surfactants such as the alkyl ethoxylates ("AE") of C-12-C18 may also be included in all compositions. including the so-called narrow-chain alkyl ethoxylates and the C-? 2-C? A alkylphenol ethoxylates (especially mixed ethoxylates and ethoxy / propoxy), C-? 2-C-? 8 betaines and sulfobetaines ("sultaines") , C10-C18 amine oxides and the like. The amines of N-alkyl-polyhydroxy acids of C-io-C-ts can also be used. Typical examples include N-methylglucamines of C-? 2- 15 Cie. See WO 9,206,154. Other surfactants derived from sugar include the N-alkoxy polyhydroxy fatty acid amides, such as C10-C18 N- (3-methoxypropyl) glucamide. The N-propyl- to N-hexyl glucamines of C10-C18 can be used, because of their low foaming. Conventional soaps of C? 0-C2o- If high foaming is desired, can be used. using branched chain C? 0-C16 soaps. Mixtures of anionic and nonionic surfactants are especially useful. Other conventional useful surfactants are listed in typical texts. __MtetfiMiMÉM_ ^ M_Mi_lrital Fecid Detergent Material The dry detergent starting material of the present process preferably comprises a builder and other chemical detergent ingredients, such as sodium carbonate, especially when a liquid acid precursor of a surfactant is used, which is needs as a neutralizing agent in the first step of the procedure. Thus, the preferable dry starting detergent material includes sodium carbonate and a phosphate or an aluminosilicate builder which is referred to as an aluminosilicate ion exchange material. A breeder is selected Preferred detergency of the group consisting of aluminosilicate, crystalline layered silicates, phosphates, carbonates and mixtures thereof. Preferred phosphate builders include sodium tripolyphosphate, tetrasodium pyrophosphate and mixtures thereof. Some additional specific examples in the inorganic phosphate builder are tripolyphosphate, pyrophosphate, polymeric metaphosphate having a degree of polymerization of about 6 to 21, and orthophosphate, sodium and potassium. Some examples of polyphosphate builders are the sodium and potassium salts of ethylene phosphonic acid, the sodium and potassium salts of ethane-1-hydroxy-1,1-diphosphonic acid and the sodium and potassium salts of ethanoic acid. 1, 1, 2-triphosphonic. Other phosphorous builders compounds are disclosed in the U.S.A. 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. ^^^^ w ^^ and || ^^^^^ g || The aluminosilicate ion exchange materials which are used herein as builders preferably have both high calcium ion exchange capacity and high exchange rate. Without intending to be bound by theory, it is believed that such a high calcium exchange rate and capacity are a function of several interrelated factors that derive from the method by which the aluminosilicate ion exchange material is produced. In that regard, the aluminosilicate ion exchange materials that are used herein are produced, preferably according to Corkill et al, U.S. No. 4,605,509, (Procter &Gamble), the invention of which is incorporated herein by reference. Preferably, the aluminosilicate ion exchange material is in the "sodium" form, since the hydrogen potassium forms of the present aluminosilicate do not exhibit the high exchange rate and capacity as provided by the sodium form. Additionally, the aluminosilicate ion exchange material is preferably in an undissolved form, so as to facilitate the production of brittle detergent agglomerates as described herein. The aluminosilicate ion exchange materials that are 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 aluminosilicate ion exchange material, as determined by additional analytical techniques, such as microscopic determination and electron microscopy. exploration (MEE). The preferred diameter of the aluminosilicate particle size is from about 0.1 micron to about 10 micron, more preferably from about 0.5 micron to about 9 micron. More preferably, the particle size diameter of the particle size is about 1 miera 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 zay is from about 1 to about 5 and x is from about 10 to about 264. More preferably, the Aluminosilicate has the formula. Na? 2 [(AI02) i2. (SiO2) i2] xH2O wherein x is from about 20 to about 30, preferably from about 27. These preferred aluminosilicates are commercially preferred, for example, with the Zeolite A, Zeolite B and Zeolite X assignments. Alternatively, materials can be made ion exchange aluminosilicate that are present in nature or synthetically derived for use herein, as described in Krummel et al, US Patent No. 3,985,669, the mention 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 of CaCO3 hardness equivalent / grams, calculated on anhydrous basis, and which is preferably in the range of about 300 to 352 mg of CaC03 equivalent hardness / grams. Additionally, the present aluminosilicate ion exchange materials are still further characterized by their calcium ion exchange rate which is at least about 2 grains Ca ++ / 3.785 liters / minute / -gram / 3.685 liters and more preferably from a range from approximately 2 grains of Ca ++ / 3,785 liters / minute / -gram / 3,685 liters to approximately 6 grains of Ca ++ / 3,785 liters / minute / -gram / 3,685 liters.

Attached Detergent Ingredients The starting dry detergent material in the present process may include additional detergent ingredients and / or any number of additional ingredients may be incorporated into the detergent composition during the subsequent steps of the present process. These adjunct ingredients include other builders, bleaches, activators bleaching, foam promoters or foam suppressors, anti-rust and anti-corrosion agents, dirt suspending agents, soil release agents, germicides, pH adjusting agents, alkalinity sources not detergent builders, chelating agents, smectite, enzymes, enzyme stabilizing agents and perfumes. See the patent of E.U.A. 3,936,537, issued February 3, 1976 to Baskerville, Jr, et al, incorporated herein by reference. Other detergency builders can be pre-selected among various borates, polyhydrosulfonates, polyacetates, carboxylates, citrates, tartrate, mono- and di-succinates, and mixtures thereof. Alkali metal salts, especially sodium salts, are preferred. In incorporation with the amorphous sodium silicates, the crystalline layered sodium silicates exhibit a clearly unscrewed calcium and magnesium ion exchange capacity. In addition, stratified sodium silicates prefer magnesium ions to calcium ions, a characteristic necessary to ensure that substantially all of the "hardness" of the wash water is removed. These crystalline layered sodium silicates, however, are generally more expensive than amorphous silicates as well as other detergency builders. According to the above, in order to provide an economically viable 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 NaMSix? 2? -.?. And H 2 O wherein M is sodium or hydrogen, x is from about 1.9 to about 4 and is about 0 about 20. More preferably, the crystalline layered sodium silicate has the formula NaMSi2O5.yH2O wherein M is sodium or hydrogen and is from about 0 to about 20. These and other crystalline layered sodium silicates are discussed in Corkill et al, US Pat. No. 4,605,509, previously incorporated herein by reference.

Some examples of non-phosphorus inorganic builders, are tetraborate decahydrate and silicates having a weight ratio of SiO2 to alkali metal acid of about 0.5 to about 4.0, preferably about 1.0 to about 2.4. The water soluble, non-phosphorous organic detergent builders, useful herein, include the various polyacetates, carboxylates, polycarboxylates and polyhydroxysulfonates of alkali metals, ammonium and substituted ammonium. Some examples of polyacetate and polycarboxylate builders are the sodium, potassium, lithium, ammonium salts, and ammonium substituted ethylenediaminetetraacetic acid, nitriloacetic acid, oxidisucinic acid, melitic acid, benzene polycarboxylic acids and citric acid. Polymeric polycarboxylate detergent builders are discussed in the U.S.A. 3,308,067, Diehl, issued March 7, 1967, the mention 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 described hereinafter, butO. only if they are intimately mixed with the anionic surfactant other than soap. Other polycarboxylates suitable for use herein are the carboxylates described in U.S. Patent 4,144,226, issued March 13. í * á? sa_. from 1979 to Crutchfield et al, and "front of E.U.A. 4,246,495, issued March 27, 1979 to Crutchfield et al, both of which are incorporated herein by reference. These polyacetalcarboxylates can be prepared by joining a glyoxylic acid ester and a polymerization initiator under polymerization conditions. The resulting polyacetal carboxylate ester is then attached to the 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 monosucinate and tartrate disucinate described in the U.S.A. 4,663,071 ,, Bush et al., Issued May 5, 1987, the mention of which is incorporated herein by reference. Bleaches and activators are described in the U.S.A. 4,412,934, Chung et al., Issued November 1, 1983, and the patent of E.U.A. 4,483,781, Hartman, issued November 20, 1984, both incorporated herein by reference. Chelating agents are also described in the U.S.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.

The smectite clays suitable for use herein are described in the U.S. patent. 4,762,645, Tucker et al, issued August 9, 1988, column 6 line 3 to column 7, line 24, incorporated herein by reference. Suitable additional detergency builders are listed for use herein, in U.S. Patent No. 4,663,071, Bush et al, issued May 5, 1987, both incorporated herein by reference. In order to make the present invention more easily understood, reference is made to the following example, which is intended to be illustrative only and is not intended to be scope limiting.

EXAMPLE This example illustrates the invention of the process in which a low density agglomerated detergent composition is prepared. A Lódige CB 30 high speed mixer is charged with a mixture of powders, namely sodium carborate (average particle size 15 microns) and sodium tripolyphosphate ("STPP") with an average particle size of 25 microns. A liquid acid precursor of sodium alkylbenzenesulfonate surfactant (C12H25-C6H4-SO3H or "HLAS" as indicated below) and a surfactant surfactant sulfate-ethoxylated paste of active aqueous C10-18 70% (EO) are also introduced. = 3, "AES") to a Lódige CB 30 mixer, where the HLAS is first added. The mixer is operated at 1600 rpm and transformed site £ Ü & The solid carbonate of STPP, HLAS and AES in agglomerates having an average particle size of approximately 110 microns after an average dwell time in the mixer Lódige CB 30 approximately 5 seconds. The agglomerates are then fed to a Schugi high-speed mixer (Model # FX160) operated at 2800 rpm with an average dwell time of about 2 seconds. An HLAS binder is introduced to the Schugi mixer (Model # FX160) during this step which results in forming shaped agglomerates having an average particle size of about 180 microns. Then, the formed agglomerates are passed through the dryer of the fluid bed which is operated with a Stokes number of 0.29, where p is 1035 g / l (apparent particle density of the formed agglomerates leaving the Schugi mixer). ), v is 0.44 m / s (speed in excess of the formed agglomerates that enter the fluid bed assuming a minimum feed rate of 0.3 m / s), d is 178 microns (average particle diameter of the conformed agglomerates that enter the fluid bed) and μ is the viscosity of 250 cps sodium silicate binder. The average droplet diameter of the sodium silicate binder is 40 microns, as measured with a Malvern particle size analyzer. The inlet air temperature of the fluid bed is maintained at approximately 125 ° C. At each end of the fluid bed dryer, liquid sodium silicate binder is fed to the fluid bed dryer resulting in agglomerates of finished detergents having a density of about 485 g / l.

Qgjá &gjgíj ^ j ^ g ^ g and an average particle size of approximately 360 micras. Unexpectedly, the finished agglomerates have excellent physical properties because they are free-flowing, as they exhibit their higher cake strengths. It is given below that in table I the composition of the agglomerates.

TABLE I (% by weight) Component I LAS (Na) 15.8 AES (EO = 3) 4.7 Sodium carbonate 48.0 STPP 22.7 Sodium silicate 5.5 Water 3.3 100.0 The agglomerates incorporate approximately 14% fine powders (less than 150 microns) which are recirculated from the fluid bed back to the CB 30 Codex which enhances the production of the agglomerates produced by this process. Having described the invention in detail, it will be apparent to those skilled in the art that various changes can 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 (10)

NOVELTY OF THE INVENTION CLAIMS

1. - A process for preparing a low density detergent composition, characterized by the steps of: (a) agglomerating a surfactant detergent paste or precursor thereof and dry starting detergent material in a first high speed mixer to obtain agglomerates; (b) mixing said detergent agglomerates in a second high speed mixer to obtain shaped agglomerates; and (c) feeding said shaped agglomerates and a binder to a fluid bed dryer to form low density detergent agglomerates having a density in a range of about 300 g / l to about 550 g / l, said fluid bed drier operating with a Stokes number of less than 1, where the Stokes Number = 8pvd / 9μ p is the apparent particle density of said shaped agglomerates, v is the excess velocity of said shaped agglomerates, d is mean particle diameter of said shaped agglomerates and μ is the viscosity of said binder.

2. The method according to claim 1, further characterized in that said number of Stokes is in a range of 0.1 to 0.5.

3. - The method according to claim 1, further characterized in that said binder has a mean droplet diameter of 20 microns at 100 microns.

4. The method according to claim 1, further comprising the step of adding a second binder to said high speed mixer in said step (b).

5. The process according to claim 1, further characterized in that said binder is sodium silicate.

6. The process according to claim 1, further characterized in that said number of Stokes is in a range of 0.1 to 0.5, said p is of a range of 800 g / l to 1400 g / l, said v is in a range from 0.1 m / s to 5 m / s, said d is in a range of 50 microns to 2000 microns and said μ is in a range of 10 cps to approximately 500 cps.

7. The process according to claim 1, further characterized in that said step (a) includes agglomerating a liquid acid precursor of linear alkylbenzenesulfonate surfactant of Cn-is and an alkyl-ethoxylated sulfate surfactant of C-io-

8. The method according to claim 1, further characterized in that said (c) includes maintaining the temperature of said fluid bed dryer so that it is in a range of 90 ° C to 200 ° C.

9. The process according to claim 1, further characterized in that said dry starting material comprises a builder which is selected from the group consisting of aluminosilicates, crystalline layered silicates, phosphates, carbonates and mixtures thereof.

10. A detergent composition made in accordance with the method of claim 1.