MXPA98002769A - Procedure to make a composition of low-density detergent by agglomeration with a salhidrat - Google Patents

Abstract

A process for preparing a low density detergent agglomerate is provided, the method comprising the steps of: agglomerating a detergent surfactant paste and a dry starting detergent material in a high speed mixer to obtain detergent agglomerates, characterized in that the detergent material dry starting includes a hydrated salt, and drying said detergent agglomerates to form the detergent composition having a density of less than about 600 g

Description

PROCEDURE TO MAKE A COMPOSITION OF LOW-DENSITY DETERGENT BY AGGLOMERATION WITH A HYDRATED SALT FIELD OF THE INVENTION The present invention generally relates to a process for producing a low density detergent composition. More particularly, the invention is directed to a process during which the low density detergent agglomerates are produced by feeding a paste of surfactant and dry starting detergent material to a high speed mixer, followed by a drying apparatus. The process produces a free-flowing low density detergent composition which can be sold commercially as a conventional non-compact detergent composition or used as an aggregate in a low dosage compact detergent product.

BACKGROUND OF THE INVENTION Within the detergent industry recently there has been considerable interest in laundry detergents that are compact and therefore have low dosage volumes. To facilitate the production of the so-called low dosage detergents, many attempts have been made to produce detergents with a high bulk density, for example, with a density of 600 g / 1 or greater. Currently, low dosage detergents are in great demand because 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 of a "compact" nature still remains to be determined. In fact, many consumers, especially in developing countries, continue to show preference for higher dosage levels in their respective laundry activities. Accordingly, there is a need in the art to produce modern detergent compositions for flexibility in the final density of the final composition. There are generally two main types of procedures by means of which detergent granules or detergent powders can be prepared. The first type of process includes spray drying a suspension of aqueous detergent in a spray-drying tower to produce porous detergent granules. In the second type of process, the various detergent components are mixed dry, after which they are agglomerated by means of a binder such as a nonionic or anionic surfactant. In both procedures, the most important factors that direct the density of the resulting detergent granules are the density, shape, porosity and surface area of the different starting materials, as well as their respective chemical composition. However, these parameters can only be varied within a limited scale. Thus, the flexibility in substantial overall density can only be achieved through the additional process steps that lead to lower densities of the detergent granules. There have been many attempts in the art to provide methods that increase the density of detergent granules or powders. Special attention has been given to the dosing of spray-dried granules through a "post-treatment" treatment. For example, an attempt includes an intermittent procedure in which granular or spray-dried detergent powders containing tripol and sodium phosphate and sodium sulfate are densified and spheronized in a Marumeri er *. This apparatus comprises a substantially horizontal rough rotary table located in the interior and base of a substantially vertical smooth wall cylinder. However, this process is essentially an intermittent process and is therefore less suitable for the production of large-scale detergent powders. Very recently, other attempts have been made to provide continuous procedures to increase the density of "post-tower" or spray-dried detergent granules. Typically, said processes require a first apparatus that pulverizes or grinds the granules and a second apparatus that increases the density of the granules sprayed by agglomeration. Although these procedures achieve the desired density increase by treating or densifying "post-tower" or spray-dried granules, they do not provide a method that has the flexibility to provide lower density granules. Moreover, all of the aforementioned methods are mainly directed to densify or otherwise process spray dried granules. Currently, the relative amounts and types of materials subjected to 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 low dose detergents more efficiently. In this way, it would be desirable to have a method by which detergent compositions could be produced without having the limitations imposed by conventional spray drying techniques. For that purpose, the technique also contains many descriptions of procedures encompassing binder detergent compositions. For example, attempts have been made to agglomerate builders by mixing zeolite and / or layered silicates in a mixer to form the free flowing agglomerates. Although such attempts suggest that the process can be used to produce detergent agglomerates, they do not provide a mechanism by which the starting detergent materials in the form of pastes, liquids and dry materials can effectively agglomerate in brittle, free-flowing detergent agglomerates. that have low densities. Accordingly, there remains a need in the art to have a process for continuously producing a low density detergent composition directly from starting detergent ingredients. There is also a need for a process that is more efficient, flexible and economical to facilitate the large-scale production of detergents of high and low dosage levels.

TECHNICAL BACKGROUND The following references are directed to densify spray-dried granules: Appel and others, Patent of F.U.A. No. 5,133,924 (Lever); Bortolotti and others, Patent of E.U.A. No. 5,160,657 (lever); Johnson and others, 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); Capeci et al., Patent of E.U.A. No. 5,366,652 (Procter &Gamble); Hollingsworh et al. Patent Application European 351,937 (Unilever); and Swatling et al., Patent of E-U.A. No. 5,205,958.

SUMMARY OF THE INVENTION The present invention satisfies the aforementioned needs in the art by providing a process that produces a low density detergent composition (less than about 600 g / 1) directly from starting ingredients. The process does not employ the conventional spray-drying towers that are currently employed and is therefore more efficient, economical and flexible with respect to the variety of detergent compositions that can be produced with the process. In addition, the procedure is more in line with environmental concerns in that it does not use dispersion drying towers, which typically emit particles and volatile organic compounds into the atmosphere. The term "agglomerates", as used herein, refers to the particles formed by agglomerating granules or detergent particles which typically have a smaller average particle size than the agglomerates formed. The phrase "at least a minor amount" of water, as used herein, means an amount sufficient to aid in agglomeration, typically in the order of 0.5% to about 10% by weight of the total amount of water contained in the mixture of all the starting components. All percentages used here are expressed as "percent by weight", unless otherwise indicated. All the viscosities described herein are measured at 70 ° C and at shear rates between about 10 to 50 sec-i, being preferable at 25 sec- *. In accordance with one aspect of the invention, there is provided a process for the preparation of low density detergent agglomerates having a density below about 500 g / 1. The method comprises the steps of: (a) agglomerating a paste of detergent surfactant and dry starting detergent material in a high speed mixer to obtain detergent agglomerates, wherein the dry starting detergent material includes a hydrated salt; and (b) drying the detergent agglomerates to form the detergent composition having a density of less than about 600 g / 1. According to another aspect of the invention, another method is provided for the preparation of low density detergent agglomerates with a density below about 500 g / 1. The method comprises the steps of: (a) agglomerating a paste of detergent surfactant and dry starting detergent material in a high speed mixer to obtain detergent agglomerates, wherein the dry starting detergent material includes a hydrated salt selected from the group consisting of citric acid, hydrated sulfates, hydrated carbonates, hydrated bicarbonates, borax pentahydrates, Afghani, Andersonite, AscroftinaY.

Carletonite, DonnayitaY, Frisurita, Franzinita, Gaylussita, Girvasita, Juravskita, ampaugita, Lepersonnita Gd, Liotita, MckelveyitaY, Sacrofanita, Schrockingeri ta, Tuscanita, Tyrolita, Vishnevita and mixtures thereof; (b) mixing the detergent agglomerates in a moderate speed mixer to subsequently agglomerate the detergent agglomerates; and (c) drying the detergent agglomerates to form the low density detergent composition having a density of less than about 500 g / 1. The low density detergent composition made by any of the embodiments of the process described herein is also provided. Therefore, an object of the invention is to provide a process for continuously producing a low density detergent composition directly from the starting detergent ingredients. Also, an object of the invention is to provide a process that is more efficient, flexible and economical to facilitate the large-scale production of detergents of low and high dosage levels. These and other objects, features and concomitant advantages of the present invention will be apparent to those skilled in the art upon reading 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 that produces low density, free-flowing detergent agglomerates with a density below 600 g / 1. The process produces low density detergent agglomerates from a highly viscous surfactant paste with a relatively high water content, typically at least about 10%. Generally speaking, the present process is used in the production of normal dosing detergents as opposed to low dosing, where the resulting detergent agglomerates can be used as a detergent or as a detergent additive. It should be understood that the method described herein may be continuous or intermittent, depending on the application desired.

Process In a first step of the process, a mixer is fed with stag detergent materials to carry out the agglomeration. To achieve the desired density below 600 g / 1, the agglomeration step is initially performed in a high speed mixer after which an optional moderate speed mixer can follow, if greater agglomeration is desired. The stag detergent materials are agglomerated in the presence of a hydrated salt, better described hereinafter as a salt that produces agglomerated pales having a density below about 600 g / 1, more preferably less than about 500 g / 1. and still more preferably from about 300 g / 1 to about 450 g / 1. the nature and composition of the incoming or stag detergent materials may vary as described below. It is preferable that the average residence time of the stag detergent materials of the high-speed mixer (eg, Lodige CB 30 Recycler or other similar equipment) be around 2 to 45 seconds, while the residence time in the optional low or moderate speed mixer (eg, Lodige KM 300 Recycler "Ploughshare" or other similar equipment) is approximately 0.5 to 15 minutes- The stag detergent materials preferably include a highly viscous surfactant paste and material dry detergent, whose components are described below in more detail. For purposes of facilitating the production of low density or "foamed" detergent agglomerates, the dry detergent material includes a hydrated salt material which has surprisingly been shown to reduce the density of the agglomerates produced in the process. It should be understood that the hydrated salt may be physically included in the surfactant paste, which is also suitable and is within the scope of the instant process invention. Although not intended to be limited to theory, it is believed that this hydrated salt intensifies the "puffing" or "puffing" of the agglomerates upon being dried in the apparatus described below. This leads to the production of agglomerates having the low density that is deaseated. For that purpose, the instant process preferably includes mixing from about 1% to about 20%, more preferably from about 3% to about 10%, of a hydrated salt material in a high speed mixer. The other essential step in the process includes drying the agglomerates leaving the high speed mixer or the moderate speed mixer, if optionally used. This can be carried out in a wide variety of apparatuses that include fluid bed dryers, but are not limited thereto. The drying step increases the free-flowing capacity of the agglomerates and boosts or initiates the "sponged" or "inflated" physical characteristics of the resulting agglomerates. Although not intended to be limited to theory, it is believed that during the drying step of the instant procedure, the hydrated salt containing the agglomerate dries extremely fast and "swells" to become a light, fluffy, low density agglomerated particle. Accordingly, sufficient drying must be given in order to produce the desired low density agglomerates. In this regard, the drying temperature employed in any of the drying apparatuses will be preferable if it is from about f.O'C to about 300 ° C, more preferably from about 80 ° C to about 250 ° C, and still being more preferably from about 100 * C to about 250 ° C. The detergent agglomerates that are produced by the process have a preferable level of surfactant of from about 20% to about 55%, more preferably from about 35% to about 55%, still more preferable from about 45% to approximately 55%. The particle porosity of the resulting detergent agglomerates, produced in accordance with the process of the invention, is preferable within a range of about 5% to about 50%, with about 25% being more preferable. In addition, an attribute of densified or dense agglomerates is the relative size of the particle. The present process typically provides detergent agglomerates having an average particle size of about 250 microns to about 1000 microns, more preferably about 400 microns to about 600 microns. The phrase "average particle size", as used herein, refers to individual agglomerates and not individual particles or detergent granules. The combination of porosity and particle size referred to above results in agglomerates having density values below 500 g / 1. Such a feature is especially useful in the production of laundry detergents having varying dosage levels, as well as other granular compositions such as dishwashing compositions.

Optional steps of the procedure In an optional step of the present process, the detergent agglomerates emerging from the fluid bed dryer are further conditioned by cooling the agglomerates in a fluid bed cooler or similar apparatus as is well known in the art. Another optional step of the process includes adding a coating agent to improve the flowability and / or reducing the agglomeration of the detergent composition in one or more of the following steps of the instant process: (1) the coating agent can be added directly after of the fluid bed cooler; (2) the coating agent can be added between the fluid bed dryer and the fluid bed cooler; (3) the coating agent can be added between the fluid bed dryer and the moderate speed mixer; and / or (4) the coating agent can be added directly to the moderate speed mixer and the fluid bed dryer. It is preferable to select the coating agent from the group consisting of aluminosilicates, silicates, carbonates, and mixtures thereof. The coating agent not only increases the free flowability of the resulting detergent composition desired by consumers by allowing the detergent to be easily removed during use, but also serves to control agglomeration by preventing or minimizing excessive agglomeration. , especially when added directly to the moderate speed mixer. As those skilled in the art know, excessive agglomeration can lead to very desirable flow and aesthetic properties of the final product. Optionally, the method can co-founder the step of spraying an additional binder in one or both of the fluid bed mixer or dryers. A binder is added for purposes of increasing the agglomeration by providing a "binder" or "sticky" agent for the detergent components. The binder is preferably selected from the group consisting of water, anionic surfactants, nonionic surfactants, polyethylene glycol, polyvinyl pyrrolidone polyacrylates, citric acid and mixtures thereof. Other suitable binding materials including those listed herein are described in Beerse et al., Patent of F.U.A. No. 5,108,646 (Procter &Gamble), the disclosure of which is incorporated herein by reference. Other optional steps contemplated by the present method include screening oversize detergent agglomerates in a screening apparatus that can take a variety of forms including, but not limited to, conventional screens chosen for the desired particle size of the finished detergent product. Other optional steps include conditioning the detergent agglomerates by subjecting the agglomerates to further drying in one of the aforementioned drying apparatuses. Another optional step of the present process includes finishing the resulting detergent agglomerates by a variety of processes including spraying and / or excising other conventional detergent ingredients. For example, the finishing step comprises spraying perfumes, aprilizers and enzymes onto the finished agglomerates to provide a more complete detergent composition. Such techniques and ingredients are well known in the art.

Detergent surfactant paste The detergent surfactant paste used in the process is preferably in the form of a viscous aqueous paste, although the forms are also contemplated by the invention. This so-called viscous surfactant paste has a viscosity of about 5,000 cps to about 100,000 cps, most preferably from about 10,000 cps to about 80,000 cps and contains at least about 10% water, very preferably at least about 20% of water. The viscosity is measured at 70 ° C and at shear rates of about 10 to 100 sec-i. further, the surfactant paste, if used, preferably comprises a detersive surfactant in the amounts specified above and the remainder water and other conventional detergent ingredients. The surfactant itself, in the viscous surfactant paste, is preferably selected from the anionic, nonionic, zwitterionic, ampholic and cationic classes and compatible mixtures thereof. The detergent surfactants useful herein are described in the Patent of F.U.A. 3,664,961, Norris, issued May 23, 1972 and in the Patent of F.U.A. 3,919,678 Laughlin et al., Issued December 30, 1975, both incorporated herein by reference. Useful cationic agents also include those described in the U.S. Patent. 4,222,905, Cockrell, issued September 16, 1980, and in the U.S. Patent. 4,239,659, issued December 1, 1980, both also incorporated herein by reference. Of the surfactants, the anionic and nonionic anions are preferred and the anionic ones are most preferred. Non-limiting examples of preferred anionic surfactants useful herein include the conventional Cn-Ciß alkylbenzene sulphonates ("LAS") and the C10-Q20 ("AS") alkyl sulphates ("AS") primary, branched chain and random, the alkyl sulfates (2, 3) Cio-Ciß secondaries of the formula CH3 (CH2) x (CH0S03 ~ M +) CH3 and CH3 (CH2) and (CH0S03"M +) CH2 H3 where xy (y +1) are integers of at least 7, preferably at least about 9, and M is a cation of solubilization in water, especially sodium, unsaturated sulaphthates such as oli sulfate, the alkylalcoxy sulfates of Cío-iß ("AFXS"; especifically lto etoxisu fatos FO 1-7). Optionally, other surfactants useful in the pulp of the invention include C 1 -Ci alkylalkoxycarboxylates (especially the Eto 1-5 carboxylate ethoxy), the glycolic ethers of Cι-Ciß, the alkylpolycoscosides of C ?o ~ Cie and their corresponding sulphated seals, and alphasulfonated fatty acid esters of C1-18- If desired, conventional nonionic amphoteric surfactants such as C12-18 alkyl ethoxylates ("AF") including the so-called narrow peak alkylethoxylates and the alkylphenollalkoxylates of 6-12 (especially ethoxylates and ethoxy / mixed propoxy), C12-18 betaines and their fobetaines ("sultaines"), Cyanis amine oxides, and the like can also be included in the overall compositions. N-alkyl polyhydroxyl fatty acid amides can also be used. Typical examples include N-methyl glucamines of 12-18- See WO 9,206,154. Other surfactants derived from sugar include the N-alkoxy polyhydric acid amides, such as N- (3-methoxypropyl) glucamine of io-iß- The N-propyl to N-hexy C12-C18 glucamides can be used for foaming low. Conventional C10-C20 soaps can also be used. If high foaming is desired, branched-chain C10-16 soaps can be used. Mixtures of anionic and nonionic surfactants are especially useful. Other conventional useful surfactants are listed in the normal texts.

Dry detergent material The dry starting detergent material of the present process preferably comprises a hydrated salt. In a preferred embodiment, the hydrated salt is selected from the group consisting of citric acid, hydrated sulfates, hydrated carbonates, hydrated bicarbonates, borax pentahydrates and mixtures thereof. In another preferred embodiment, the hydrated salt is selected from the group consisting of Afghanite, Andersonite, Ashcroftina, Carletonite, Donnayita, Ferrisurita, Franzinita, Gaylussita, Girvasita, Jouravskita, Kamphaugi taY, Lepersonni aGd; Liottita, Mckel veyi taY, Sacrofanita, Schrocking ri ta, Tunisita, Tyrolita, Vishnevita and mixtures thereof. The aforementioned materials are listed below in cross reference with their respective chemical formulas. Afghan, (Na, Ca, K) ß (Si, Al) i2? 2 (SO /,, Cl, C03) 3 - (H2O); Andersonite, Na, Ca, (UO2 XCO3) 3 - (6H2O); AshcroftinaY, Ks as (Y, Ca) i2SÍ2s? 70 (0H) 2 (C0-3) ß .n (H-20), where n is 3 or 8. Carletonite, KNa-; Si-80i8 (CO3) A (0H, F). (H2O): Donnayi taY, S r3 NaCaY (C03) e -3 (H20); Ferrisurite, (Pb, Ca) 3 (C03) 2 (OH, F) (Fe. Al) 2 S O (O) 2 »n (H20). Fn where n is an integer from 1 to 20; Franzinite, (Na, Ca) 7 (Si, Al) i2? 2-i (SO .;, C03, 0H, C1 3 • (H2O); Gaylussite, Na2 a (? 3) 2 »5 (H2?); Gi rvasi ta, NaCa2Mg3 (PO?) 2 [P02 (0H) 2] (C03) (0H) 2 »4 (H20); Jouravskita, CagMn2 (SO *, C? 3) A (0H) i2» n (H2 ?). Fn where n is 24 or 26; KamphaugitaY, CaY (C03) 2 (0H) * (H0); Lepersonni taGd; Ca (Gd, Dy) 2 (U0-2) -24 (C03) -8 (S 0i2) 0I6 «60 (H20); Liottite, (Ca, Na, K) 8 (Yes, Al)? 02, (SO, C03, Cl, 0H) 4 »n (H20), where n is 1 or 2; MckelveyitaY, Ba3Na (Ca, U) Y (C0-3) 6 * 3 (H20); Sacrofani ta, (Na, Ca, K) 9 (Si, Al) i2? 2, [(0H) 2; S0-,? 3, C1-2]? »N (H2?), Where x is 3 or 4 and n is an integer from 1 to 20; Schrockingerite, NaCa3 (UO2 X O3) 3 (O4) F »10 (H20); Tunisite, K (Ca, Na) 6 (Si, Al)? O022CSO /, .CO3, (0H) 23 »(H20); Tyrolite, CaCus (AsO) 2 (CO3) (OH) -4 »6 (H2?); and Vishnevi ta (Na, a, K) ß (Si, Al)? 2 O2 (SO4, C03, Cl2) 2-4 • n (H20). Another preferred embodiment involves selecting the hydrate salt of any of the aforementioned lists. Although the hydrated salts listed herein are suitable in the present process, other hydrated salts that have not been listed may also be used provided they are organic or inorganic materials that are or have been hydrated with at least water of hydration.

The dry starting detergent material of the present process preferably comprises a detergent aluminosilicate detergent builder which is known as aluminosilicate ion and sodium carbonate exchange materials. The aluminosilicate ion exchange materials used herein as a builder preferably have a high calcium ion exchange capacity and high exchange rate. Without intending to be limited by theory, it is believed that said rate of ion exchange with high calcium content and 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 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 form of "sodium" since the potassium and hydrogen forms of the alumino silicate present do not have an exchange rate and exchange capacity as high as that provided by the sodium form . In addition, the aluminosilicate exchange material preferably is in excess dry form to facilitate the production of brittle detergent agglomerates as described herein. The aluminosilicate ion exchange materials herein used 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 an aluminosis ion exchange material as determined by conventional analytical techniques, such as microscopic determination and electron microscopy. Sweep (SFM). The preferred particle size diameter of the aluminosilicate is from about 0.1 microns to about 10 microns, most preferably from about 0.5 microns to about 9 microns. Most preferably, the diameter of particle size is from about 1 miera to about 8 micras. Preferably, the aluminosilicate ion exchange material has the formula: Naz [(A102) z (SiO2) y] xH20 where z and y are integers of at least 6, the molar ratio of zay is on the scale of about 1 to about 5, and x is an integer from about 10 to about 264. Most preferably, the aluminosilicate has the formula: Nai2C (A102) 12 (S02) 12] xH2? wherein x is from about 20 to about 30, specifically about 27. These preferred aluminosilicates are available under the designations Zeolite A, Zeolite B and Zeolite X. Alternatively, aluminosilicate ion exchange materials occur naturally or synthetically derived derivatives suitable for use herein may be made as described in Kru mel et al., Patent No. FUA 3,985,669, the disclosure of which is incorporated herein by reference. the aluminosilicates used herein are further characterized by their calcium ion exchange capacity, which is at least 200 mm water hardness equivalents of CaC 3 / g aluminosilicate, calculated on an anhydrous basis and which are generally on the scale of 300 mg eq./ga 352 mg eq./g. In addition, the aluminosilicate ion exchange materials herein are further characterized by their calcium ion exchange rate which is at least 2 grains of Ca ++ / 3.78 liters / mi nuto / (g bouquet / 3.78 liters) and very preferably from 2 grains / 3.78 liters / minute / (gram / 3.78 liters) to approximately 6 grains Ca ++ / 3.78 liters / mi nuto / 3.78 liter / mi nuto / g bouquet / 3.78 liters.

Auxiliary detergent ingredients The dry starting 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 auxiliary ingredients include other builders, bleaches, activators. bleaching, foam enhancers or suds suppressors, anti-rust and anti-corrosion agents, soil suspending agents, soil release agents, germicides, pH adjusting agents, alkalinity sources which are not detergency builders, chelating agents, smectite clays, enzymes, enzyme stabilizing agents and perfumes. See U.S. Pat. 3,936,537, issued February 3, 1976 to Baskerville, Jr., et al., Incorporated herein by reference. Other builders can generally be selected from alkali metal, ammonium or substituted ammonium phosphates, polyphosphates, polyphosphonates, carbonates, borates, polyhydroxysulphonates, polyacetates, carboxylates and polycarboxylates soluble in water. Alkali metals are preferred, especially sodium salts of the above. Phosphates, carbonates, C?-18 fatty acids, polycarboxylates and mixtures thereof are preferred for use herein. Very preferred are sodium tripolyphosphate, tetrasodium pi-phosphate, citrate, tartrate, mono- and disuccinates and mixtures thereof (see below). Compared to amorphous sodium silicates, the crystalline layered sodium silicates show a clearly increased calcium and magnesium ion exchange capacity. Furthermore, magnesium ions rather than calcium ions are preferable for the stratified sodium silicates, a necessary feature 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 feasible laundry detergent, the ratio of sodium silicates to crystalline ratites which are used should be determined judiciously. The crystalline layered sodium silicates for use herein preferably have the formula: NaMSi? 02? +? «YH2? wherein M is sodium or hydrogen, x is from about 1-9 to about 4 e, and is from about 0 to about 20. Most preferably, the crystalline layered sodium silicate has the formula: NaMSÍ2? s »H2? wherein M is sodium or hydrogen, and y is from about 0 to about 20. These and other crystalline layered sodium silicates are described in Corkill et al., Patent of F.U.A. No. 4,605,509, formerly incorporated herein by reference. Specific examples of inorganic phosphate reagent enhancers are tripolyphosphate, pyrophosphate, polymeric metaphosphate having a degree of potency of about 6 to 2, and sodium and potassium orthophosphates.

Examples of polyphosphonate builders are the sodium and potassium salts of ethylenediphosphonic acid, the sodium and potassium salts of ethan-1-hydroxy-1, -diphosphonic acid and the sodium and potassium salts of ethanolic acid. , 1, 2-t rifosphonic. Other phosphorus builder compounds are described in U.S. Patent Nos. 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 non-phosphorus inorganic builders are ruthen-decahydrate and silicates having a weight ratio of SiO 2 to alkali metal oxide of about 0.5 to about 4.0, preferably about 1.0 to about 2.4. Non-phosphorus, water-soluble 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 ethylenediaminetetraacetic acid, nitrilotriacetic acid, succinic acid, mellitic acid, benzene carboxylic acids and citric acid. Polymeric carboxy-polymer builders are disclosed in the U.S. Patent. 3,308,067, issued March 7, 1967, the description 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 below, but only if it is in intimate admixture with the anionic surfactant which is not soap. Other polycarboxylates suitable for use herein are the polyacetalcarboxylates described in the U.S. Patent. No. 4,144,226, issued March 13, 1979 to Crutchfield et al., And the Patent of F.U.A. No. 4,246,495, issued March 27, 1979 to Crutchfield and others, both incorporated herein by reference. These polyacetalcarboxylates can be repaired under polymerization conditions by a glyoxylic acid ester and a polymerization initiator. The resulting polyacetal carboxylate ester is then fixed 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 poly-carboxylate builders are ether carboxylate builder compositions which comprise a combination of the monosuccinate and tartrate-disuccinate moiety described in U.S. Pat. No. 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. No. 4,412,934, Chung et al., Issued November 1, 1983 and in the U.S. Patent. No. 4,483,781, Hartman, issued November 0, 1984, both incorporated herein by reference. Chelating agents are also described in the Patent of F.U.A. No. 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 U.S. Pat. No. 3,933,672, issued January 20, 1976 to Bartoletta et al. And 4,136,045, issued January 23, 1979 to Gault and others, both incorporated herein by reference. Smectite clays suitable for use herein are described in U.S. Patent No. 4,762,645, Tucker et al., Issued August 9, 1988, Column 6, Line 3 to Column 7, Line 24 and incorporated herein by reference. Additional builders suitable for use herein are listed in U.S.A., Baskerville, 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. In order to make the present invention more easily understood, reference is made to the following examples, which are intended to be illustrative only and not limiting in how much to reach.

EXAMPLE I This example illustrates an intermittent mode of the present method. A low density agglomerated detergent composition is prepared using a Cuisenart ™ food processor which is a high speed mixer. The mixer is first charged with a mixture of dry detergent powders, namely sodium carbonate (average particle size of 5 to 30 microns through an air-rated mill (Air Classified Mili), light-weight sodium tripolyphosphate ( supplied by FMC Corporation) and non-blown borax pentahydrate (supplied by USBORAX) A surfactant paste comprising 70% by weight of sodium alkyl sulfate derived from coconut oil (CnAS) and 30% water is then added above the powder mix while the mixer is being operated for 15 seconds at high speed.The formula Cn S is CxHx0S03 a where x = 12, 14 and 16 ey = 2x + 1- The surfactant paste is added until that discrete agglomerates or granules are formed in the mixer The wet agglomerates are then transferred to a Niro ™ fluid bed dryer The agglomerates are dried in a bed at a temperature of 200 ° C with an air flow of 0-98 m / s have So that an escape temperature of 158 ° C is reached. The composition of the agglomerates is given later in Table I.

TABLE I (% by weight) Component T CnAS 34.0 Carbonate laughs fine sodium 20.6 STPP 24.8 Borax pentahydrate ("not inflated") * 20.6 Volumetric density before drying (g / 1) 627 Volumetric density after drying (g / 1) 363 * The "not inflated" aspect of the pentahydrate indicates that it is not dry, but is in its hydrated state. The resultant agglomerates unexpectedly had a volumetric density after drying of 363 g / 1 and cake formation and flowability showed good resistance.

COMPARATIVE EXAMPLES II-III These examples are prepared by the procedure described in Example T, but do not contain a hydrated salt and are therefore presented here for comparison purposes. The following compositions were made as shown in table IT.

TABLE II (% by weight) Component II TTT CnAS 39 33.8 Sodium carbonate fine 30.5 20.6 STPP 30.5 25.0 Pentahydrate laughs borax ("inflated") * - 20.6 Volumetric density before drying (g / 1) 565 572 Density after drying (g / l) 363 561 588 * The "inflated" aspect of this pentahydrate indicates that it has dried before being used in the procedure. The resulting agglomerates have a bulk density which is considerably higher since the particles do not "swell" upon drying at a lower density since a hydrated salt is not used in the process. The TT example uses a dry or "inflated" borax pentahydrate that is not hydrated. Having thus described the invention in detail, it will be clear to those skilled in the art that various changes can be made without departing from the scope of the invention and the invention should not be considered limited to what is described in the specification.

Claims (4)

NOVELTY OF THE INVENTION CLAIMS

1. - A process for preparing a low density detergent composition comprising the steps of: (a) agglomerating a detergent surfactant paste and a dry starting detergent material in a high speed mixer to obtain said agglomerates, characterized the detergent material of dry batch includes a hydrated salt; and (b) drying said detergent agglomerates to form the detergent composition having a density of less than 600 g / i.

2. A method according to claim 1, further characterized in that the density of the detergent compositions is less than 500 g / 1.

3. A process according to claims 1-2, further characterized in that said dry starting material is characterized by a builder selected from the group consisting of aluminosilicates, crystalline layered silicates, anhydrous sodium carbonate and mixtures thereof. the same.

4. A process according to claims 1-3, further characterized in that said hydrated salt is selected from the group consisting of citric acid, hydrated sulfates, hydrated carbonates, hydrated bicrabonate, borax pentahydrates and mixtures thereof. 5 - A method according to claims 1-3, further characterized in that said hydrated salt is selected from the group consisting of Afghanite, Andersonite, AscroftinaY, Carletonita, DonnayitaY, Ferrisurita, Franzinita, Gaylussita, Girvasita, Juravskita, KampaugitaY, Lepersonnita Gd, Liottita, Mckelveyi taY, Sacrofanita, Schrockingeri a, Tuscanita, Tyrolita, Vishnevita and mixtures thereof. 6. A method according to claims 1-5, further characterized in that the average residence time of said detergent agglomerates in the high-speed mixer is in the range of 2 seconds to 45 seconds. 7. A process according to claims 1-6, further characterized in that said surfactant paste has a viscosity of 5,000 cps. at 100,000 cps. 8. A process according to claims 1-7, further characterized in that said surfactant paste is characterized by water and a surfactant selected from anionic, nonionic, zwitterionic, ampholytic and cationic surfactants and mixtures thereof. 9. A process according to claims 1-8, further characterized by the step of mixing detergent agglomerates in a speed-to-air mixer after the agglomeration step and before the drying step to agglomerate further detergent agglomerates. 10. A process for preparing a low density detergent composition comprising the steps of: (a) agglomerating a detergent surfactant paste and a dry starting detergent material in a high speed mixer to obtain said agglomerates, wherein the Dry starting detergent material includes a hydrated salt selected from the group consisting of citric acid, hydrated sulfates, hydrated carbonates, hydrated bicrabonate, phorahydrate, borax, Afghanite, Andersonite, Ascroftina, Carletonite, Donna, Y, Y, Frisurite, Franzinite, Gaylussita, Girvasite. , Juravskita, KampaugitaY, Lepersonnita Gd, Liottita, Mckelveyi taY, Sacrofanita, Senrockingerita, Tuscanita, Tyrolita, Vishnevita and mixtures thereof; (b) mixing said detergent agglomerates in a blended speed mixer to further agglomerate the detergent agglomerates; and (c) drying said detergent agglomerates to form the low density detergent composition having a density of less than 500 g /.