PROCESS FOR MAKING A FREE-FLOWING PARTICULATE DETERGENT ADMIX CONTAINING NONIONIC SURFACTANT

Abstract: A process for making a free-flowing particulate detergent admix that contains nonionic surfactant is disclosed. The nonionic surfactant is in the form of various sorbitan esters encased in a matrix of a plastic, organic structuring agent that can be readily dissolved or dispersed in an aqueous laundry bath. The nonionic detergent admix can be incorporated in granular laundry detergent products.

Description: PROCESS FOR MAKING A FREE-FLOWING PARTICULATE DETERGENT ADMIX CONTAINING NONIONIC SURFACTANT FIELD OF THE INVENTION The present invention generally relates to a process for making a free-flowing particulate detergent admix containing nonionic surfactant More particularly, the particulate detergent admix is made by melting selected sorbitan esters with polyethylene glycol to form a molten mixture, cooling the molten mixture to form a solidified mass, and then treating the solidified mass so as to form the particulate detergent admix Mixing the detergent admix into granular detergent products avoids the manufacturing problems associated with spraymg oily nonionic surfactant directly onto detergent granules BACKGROUND OF THE INVENTION When compared to anionic surfactants, nonionic surfactants are especially useful in detergent products because they are biodegradable, they are less sensitive to water hardness and they foam less strongly in aqueous solutions In addition, nonionic surfactants exhibit excellent cleaning ability in cold water solutions and are particularly effective in removing silts and clays Thus, they are a desired ingredient in detergent compositions The physical properties of nonionic surfactants, however, make it difficult to manufacture granular detergent compositions with high levels of the surfactant Low molecular weight nonionic surfactants are typically oily mateπals that are liquid at room temperature, while higher molecular weight nonionic surfactants have a pasty to waxy consistency Because they are difficult to process, nonionic surfactants are usually incorporated into detergent compositions by spraymg the surfactant in liquid form onto die detergent granules However, the total level of nonionic surfactant in the detergent product is limited since spraying high levels of these oily liquids onto the detergent matrix will result in "caking" of the detergent product Such "caking" increases manufacturing costs because it introduces flow and handling difficulties Moreover, "caked" product is unacceptable to consumers and can lead to difficulties in scooping or otherwise removing the detergent from the box Also, spraymg large amounts of liquid nonionic surfactant on to the detergent granules tends to decrease the density of the final granular detergent product, making the detergent more bulky and cumbersome for the consumer Thus, mere has been a need in the detergent industry for a manufacturing process that provides a detergent composition having a high level of nonionic surfactant without deletenouslv affecting the granular detergent product's flow properties or the appeal of the detergent to consumers However, attempts to increase the level of nonionic surfactant using the oily spray-on method have largely failed because they do not lead to a free-flowing, high- density granular detergent Accordingly, it would be desirable to have a process for increasing the level of nonionic surfactant in detergent granules that is economical from a manufacturing viewpoint, yet still provides detergent granules with high cleaning profiles and good consumer appeal BACKGROUND ART The following references relate to detergent granules, the solubility thereof and/or the flow properties of such granules U S Patent No 4,715,979 (Moore et al , 1987), U S Patent No 5,009,804 (Clayton et al , 1991), U S Patent No 4,006, 1 10 (Kenny et al , 1977), U S Patent No 5, 149,455 (Jacobs et al , 1992) and U S Patent No 4,637,891 (Delwel et al , 1987) The following references are directed to spray-dried granules U S Patent No 5, 133,924 (Appel et al , 1992), U S Patent No 5, 160,657 (Bortolotti et al , 1992), and British Patent No 1,517,713, (Johnson et al , 1974) The following references disclose the use of vaπous sorbitan ester compounds or deπvatives to treat fabπcs Atlas Powder Company Bulletin No 9, "Industrial Emulsions with Atlas Surfactants," ( 1953), U S Patent No 2,461,043, (Eisen et al , 1955), U S Patent No 3,652,419 (Karg et al , 1972) and U S Patent No 3,827,1 14 (Crossfield et al , 1974) The following reference relates to using structuring agents in detergent formulations U S Patent No 4,652,392 (Baginski et al , 1987) SUMMARY OF THE INVENTION The present invention meets the needs identified above by providing a process for making a particulate detergent admix having high levels of nonionic surfactant that can be incorporated into granular laundry detergent products The claimed process eliminates the need to spray oily nonionic surfactants onto laundry detergent granules, thereby avoiding the handling difficulties that arise when the granules become tacky from the nonionic spray The present invention also avoids the problem of density loss in the detergent granules that can occur when excess nonionic surfactant is on the detergent matπx The claimed process is particularly useful for making granular laundry products that contain no zeolite or carbonate, mateπals which are effective absorbents for nonionic surfactant, as well as for products containing high levels of bleach In accordance with one aspect of the a process for incorporating nonionic surfactant into a free-flowing particulate detergent admix is provided Specifically, the process comprises the steps of mixing a sorbitan ester with a structuring agent having a melting point above room temperature at a temperature sufficient to form a molten mixture, and treating the molten mixture so as to form the particulate detergent admix The sorbitan ester has the formula wherein W+X+Y+Z equals from 0 to 40, R, is (C n H 2n+1 )COO, R 2 is (OH) or (C n H2 n+ ι)COO, and n is an integer of from 11 to 17 In another embodiment of the invention, the sorbitan ester is selected from the group consisting of polyethoxylated esters, nonethoxylated esters, and mixtures thereof Preferably, the polyethoxylated ester is polyethoxylated sorbitan tπstearate having 20 ethoxy groups, wherein according to the above formula R ] and R 2 are (C n H 2n +ι)COO, n is 17, and W+X+Y+Z equals 20, and the nonethoxylated ester is sorbitan monostearate, wherein according to the above formula R ] is (C n H 2n+ ι)COO, n is 17, R 2 is (OH), and W+X+Y+Z equals 0 In another embodiment of the invention, the weight ratio of polyethoxylated sorbitan ester to nonethoxylated sorbitan ester is from about 0 1 1 0 to about 5 0 1 0 In another embodiment of the invention, the structuπng agent is polyethvlene glycol, preferred is a polyethylene glycol having a molecular weight of from about 1,500 to about 100,000 Additionally, the mean particle size of the free-flowing particulate detergent admix is from about 100 microns to about 2000 microns In another embodiment of the invention, the sorbitan ester compπses from about 5% to about 80% of the particulate detergent admix The invention also encompasses a process wherein the structuπng agent compπses from about 20% to about 95% of the particulate detergent admix In addition, the melting point of the molten mixture is greater than greater than 37 8 °C The claimed invention also includes treating the molten mixture so as to form the particulate detergent admix by cooling the molten mixture to form a solidified mass and gπndmg the solidified mass so as to form the particulate detergent admix The invention also includes the step of pπlling the molten mixture of structuπng agent and sorbitan ester so as to form the particulate detergent admix Further, the present invention encompasses a process of incorporating the particulate detergent admix into granular laundry products In an especially preferred embodiment of the invention the process consists of mixing from about 40% to about 60% by weight of a mixture of sorbitan esters having the formula ^( yw (o ^ i. Vvherein said mixture compπses polyethoxylated sorbitan tπstearate, wherein R ] and R 2 are (C n H 2n+ 1 )COO, n is 17, and W+X+Y+Z equals from 0 to 40, and sorbitan monostearate, wherein R, is (C n H 2n+1 )COO, n is 17, R 2 is (OH), and W+X+Y+Z equals 0. and from about 40%) to about 60% by weight of a polyethylene glycol at a temperature sufficient to form a molten mixture, said polyethvlene glycol having a melting point above room temperature, and treating the molten mixture so as to form the particulate detergent admix Preferably, the polyethoxylated sorbitan tπstearate has 20 ethoxy groups, wherein W+X+Y+Z equals 20 Also, the weight ratio of the polyethoxvlated sorbitan tπstearate to the sorbitan monostearate is from about 0 1 1 0 to about 5 0 1 0 Accordingly, it is an object of the present invention to provide a process for making a particulate detergent admix containing high levels of nonionic surfactant that avoids the difficulties inherent in pπor art processes when the level of nonionic surfactant sprayed onto the detergent matπx is increased It is also an object of the present invention to provide a process for making a particulate detergent admix that can be mixed with detergent granules to enhance cleaning performance and consumer appeal of the total detergent product These and other objects, features and attendant advantages of the present mvention will become apparent to those skilled in the detergent art from reading the following detailed descπption of the preferred embodiment and the appended claims All percentage, ratios, and proportions used herein are by weight unless otherwise specified All documents, including patents and publications, cited herein are incorporated by reference DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The process of the present invention compπses two essential steps First, a sorbitan ester or mixture of sorbitan esters is mixed with a structuπng agent havmg a melting point above room temperature at a temperature sufficient to form a molten mixture Second, the molten mixture is treated to form detergent admix particles The detergent admix particles are free-flowing, and can be incorporated into granular laundry detergent products The individual steps and components of the process claimed herein are descπbed in detail, below SORBITAN ESTER COMPONENT The first essential ingredient in the process for making the free-flowing particulate detergent admix is a sorbitan ester having the formula wherein W+X+Y+Z equals from 0 to 40, R j is (C n H 2n+ ι)COO, R 2 is (OH) or (C n H 2n+ ι)COO, and n is an integer of from 1 1 to 17 In preferred embodiments of the process herein, the sorbitan esters are either nonethoxylated (W+X+Y+Z equals 0) or have a degree of ethoxylation of 20 (W+X+Y+Z equals 20) One polyethoxylated sorbitan ester useful in the process herein is polyethoxylated sorbitan monostearate having a degree of ethoxvlation of twenty according to formula (I), wherein Rι is (C n H 2n+ ι)COO, n is 17, R 2 is (OH), and W+X+Y+Z equals 20, i e , C 6 H 9 0 2 (C 2 H 4 O) 20 (OH) 2 (C 17 H 35 COO) A preferred polyethoxylated sorbitan ester is polyethoxylated sorbitan tπstearate having a degree of ethoxylation of twenty according to formula (I), wherein R j and R 2 are (C n H 2n+ ι)COO, n is 17, and W+X+Y+Z equals 20, I e , having the following structure (II) (C I7 H 35 COO)(OC 2 H 4 ) χ One nonethoxylated sorbitan ester useful in the process herein is sorbitan monopalmitate according to formula (I), wherein R j is (C n H 2n+ j )COO, n is 15, R 2 is (OH), and W+X+Y+Z equals 0, I e , C 6 H 9 0 2 (OH) 2 (C , 5 H 3 , COO) A preferred nonethoxylated sorbitan ester is sorbitan monostearate according to formula (I), wherein R j is (C n H 2n+ 1 )COO, n is 17, R 2 is (OH), and W+X+Y+Z equals 0, i e , hav g the following structure The above-descπbed sorbitan ester mateπals are commercially available under several trade names, such as GLYCOSPERSE TS 20 from Lonza (polyethoxylated sorbitan tπstearate), GLYCOSPERSE S 20 from Lonza (polyethoxylated sorbitan monostearate), RADIASURF 7145 from Fina (sorbitan monostearate), RADIASURF 7135 from Fma (sorbitan monopalmitate), and ARMOTAN MP from Akzo Nobel (sorbitan monopalmitate) The process descπbed herein encompasses using a mixture of polyethoxylated and nonethoxylated sorbitan esters It has been discovered that when the process incorporates certam ratios of polyethoxylated and nonethoxylated sorbitan esters, the cleaning performance of the particulate detergent admix is enhanced Anomer benefit to varying the ratio of polyethoxylated and nonethoxylated sorbitan esters is that a target surfactant hydrophilic lipophilic balance in the granular laundry detergent product can be obtained A weight ratio of polyethoxylated sorbitan ester to nonethoxylated sorbitan ester of from about 0 1 1 0 to about 5 0 1 0 works well with the claimed process, preferably the ratio is from about 1 0 3 0 to about 3 0 1 0, most preferably from about 1 0 2 0 to about 2 0 1 0 The amount of sorbitan ester used in the claimed process will vary depending on the cleaning performance objectives for the final granular laundry detergent product Typically, the sorbitan ester will be present in the detergent admix in an amount of from about 5% to about 80%), preferably from about 25% to about 80%, most preferably from about 40% to about 60%) These ranges are equally applicable when the preferred esters of polyethoxylated sorbitan tπstearate and nonethoxylated sorbitan monostearate are used in the claimed process STRUCTURING AGENT COMPONENT The sorbitan ester must be incorporated within (I e , coated, encapsulated, covered by, internalized, or otherwise substantially contamed within) a substantially water-soluble, or water-dispersible, and nonhygroscopic structuπng agent which must be impermeable to detergents and alkalinity and which, itself, must be substantially nonsurface active By "substantially nonsurface active" it is meant that the structuπng agent itself does not interact with the sorbitan ester in such fashion that the sorbitan ester is emulsified or otherwise excessively dispersed pπor to its release in the wash water, hence reducing the cleaning effectiveness of the sorbitan ester Of course, when prepaπng the free-flowing detergent admix, it is preferable that the structuπng agent be substantially dry and nontacky at ambient temperatures Accordingly, it is preferred herein to use as the structuπng agent a plastic, organic compound which can be conveniently melted, mixed with the sorbitan ester, and thereafter cooled to form admix particles There are a wide vaπety of such structuπng agents useful herein Since the nonionic sorbitan ester surfactant is to be releasably incorporated in the structuπng agent, such that the surfactant is released into the aqueous laundrv bath when the granular laundry detergent product containing the nonionic detergent admix is added to wash water, it is preferred that the structuπng agent be water soluble However, water-dispersible mateπals are also useful since they will also release the sorbitan ester when added to the laundry bath A wide vaπety of structuπng agents having the requisite solubilitv/dispersibility characteπstics and the essential features of being substantially nonsurface active, substantially nonhygroscopic and substantially detergent-impermeable are known However, polyethylene glycol (PEG) which has substantially no surface active characteπstics is highly preferred herein PEG, havmg molecular weights of from about 1,500 to about 100,000, preferably from about 3,000 to about 20,000, most preferably from about 5,000 to about 10,000 can be used Surpnsingly, highly ethoxylated fatt alcohols such as tallow alcohol condensed with at least about 25 molar proportions of ethylene oxide are also useful herein Other alcohol condensates containing extremely high ethoxylate proportions (about 25 and above) are also useful herein Such high ethoxylates apparently lack sufficient surface active characteπstics to interact or otherwise interfere with the desired cleaning properties of the sorbitan esters A vaπety of other mateπals useful as structuπng agents herein can also be used, e g , gelatin, agar, gum arable; and vaπous algae-deπved gels The amount of earner used to isolate the sorbitan ester from the granular detergent product is important, although not cπtical It is only necessary that enough structuπng agent be used to provide sufficient volume that substantially all the sorbitan ester can be incorporated therein Likewise, it is preferred to have enough structuπng agent to provide for sufficient strength of the resultant admix particle to resist premature breakage Generally, the structuπng agent compπses from about 20% to about 95%, by weight of the detergent admix, preferably from about 20% to about 75%, most preferably from about 40% to about 60% These amounts are equally applicable when the preferred structuπng agent, PEG, is used in the process herein FORMING THE DETERGENT ADMIX PARTICLES The claimed process encompasses the steps of combining the sorbitan ester with the structuπng agent and treating the combination so as to form the free-flowing detergent admix particles The structuπng agent and the sorbitan ester can be combined through any number of conventional methods known to those of average skill in the art The process descπbed herein utilizes the step of mixing the structuπng agent and the sorbitan ester at a temperature above the melting point of both components so as to form a molten mixture having the sorbitan ester dispersed throughout the liquefied structuπng agent In order to form a supporting matπx upon cooling, the molten mixture should have a melting/freezing point greater than 37 8 °C, preferably greater than 43 3 °C, most preferably greater than 48 9 °C It is recognized that there are numerous possible vaπations in the above-descπbed method that would accomplish the same result of dispersing the sorbitan ester throughout the structuπng agent medium However, the critical aspect of this step is that the molten mixture have a melting/freezing point above room temperature so mat the structuπng agent can form a supporting matπx for holding the nonionic surfactant sorbitan ester duπng storage of either the particulate detergent admix or a granular detergent product containing the same By "room temperature" is meant temperatures between 15 6 °C and 37 8 °C After dispersing the sorbitan ester in the structuπng agent medium, the molten mixture is treated so as to form the detergent admix particles One method of accomplishing this is to cool the mixture so that the structuπng agent solidifies into a solid-like mass containing the dispersed sorbitan ester The solidified mass is then further treated to form particles suitable for admixing into granular laundry products by any number of ways, including, but not limited to, flaking, crushing, and/or gπnding Flaking involves milling or extruding the molten mixture to form a thin sheet, cooling to solidify the structuπng agent, and breaking the sheet into particles of the πght size An alternative method can be used where thin films are formed by cooling the molten mixture of structuπng agent and sorbitan ester on, e g , a chill roll or belt cooler and then breaking the film into appropπate sized flakes Another way of forming the admix particles is to pπll the molten mixture through a cooling tower, a common procedure known in the detergent industry A discussion of vaπous pπlling techniques is found in Perry's Chemical Engineers' Handbook (Sixth Ed , 1984) on pages 8-70 to 8-71, which is incorporated herein by reference One of ordinary skill in the art will recognize that there are numerous vaπations to the above-descπbed methods as well as other methods known in the detergent industry that will accomplish the objective of forming the detergent admix particles from the mixture of sorbitan ester and structuπng agent The detergent admix particles formed from the molten mixture of sorbitan ester and structuπng agent are screened to select particles of appropπate size for inclusion in granular laundry products The process descπbed herein encompasses using detergent admix particles of from about 100 microns to about 2000 microns, preferably from about 200 microns to about 1500 microns, most preferably from about 300 microns to about 1000 microns DETERGENT COMPONENTS The free-flowing particulate detergent admix containing nonionic surfactant can be incorporated into a fully formulated granular laundry detergent composition having a vaπety of common detergent ingredients including a surfactant system The surfactant system of the granular laundry detergent can include anionic, nonionic, zwitteπonic, ampholytic and cationic classes and compatible mixtures thereof Detergent surfactants are descπbed in U S Patent 3,664,961, Norπs, issued May 23, 1972, and in U S Patent 3,919,678. Laughhn et al , issued December 30, 1975, both of which are incorporated herein by reference Cationic surfactants include those descπbed in U S Patent 4,222,905, Cockrell. issued September 16, 1980, and in U S Patent 4,239,659, Murphy, issued December 16, 1980, both of which are also incorporated herein by reference Nonluniting examples of surfactant systems include the conventional C \ ι -C j g alkyl benzene sulfonates ("LAS") and pπmary, branched-chain and random C 10-C20 alkyl sulfates ("AS"), the C iQ-C i secondary (2,3) alkyl sulfates of the formula CH 3 (CH 2 ) x (CHOS0 3 " M + ) CH3 and CH3 (CH 2 )y(CHOS0 3 " M + ) CH 2 CH 3 where x and (y + 1) are integers of at least about 7, preferably at least about 9, and M is a water-solubihzing cation, especially sodium, unsaturated sulfates such as oleyl sulfate, the C iQ-C j g alkyl alkoxy sulfates ("AE^S", especially EO 1-7 ethoxy sulfates), C io-C j alkyl alkoxv carboxylates (especially the EO 1-5 ethoxycarboxylates), the C I Q- 18 g'ycerol ethers, the C [o _ C i8 alkyl polyglycosides and their corresponding sulfated polyglycosides, and C 12"C 18 alpha-sulfonated fatty acid esters If desired, the conventional nonionic and amphoteπc surfactants such as the C ^-C i g alkyl ethoxylates ("AE") including the so-called narrow peaked alkyl ethoxylates and Cg-C ^ alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), C ι 2 -C jg betames and sulfobetames ("sultaines"), C j o-C j amine oxides, and the like, can also be included in the surfactant system The C j Q-C 1 g N- alkyl polyhydroxy fatty acid amides can also be used Typical examples include the C j2 - C 1 g N-methylglucamides See WO 9,206, 154 Other sugar-deπved surfactants include the N-alkoxy polyhydroxy fatty acid amides, such as C i Q -Ci N-(3-methoxypropyl) glucamide The N-propyl through N-hexyl C ι 2 -C ι g glucamides can be used for low sudsing C κ)-C 2 o conventional soaps may also be used If high sudsing is desired, the branched-chain C 1 Q-C \ g soaps may be used Mixtures of anionic and nonionic surfactants are especially useful Other conventional useful surfactants are listed in standard texts The granular detergent composition to which d e particulate detergent admix can be added can, and preferably does, include a detergent builder Builders are generally selected from the vaπous water-soluble, alkali metal, ammonium or substituted ammonium phosphates, polyphosphates, phosphonates, polyphosphonates, carbonates, silicates, borates, polyhydroxy sulfonates, polyacetates, carboxylates, and polycarboxylates Preferred are the alkali metal, especially sodium, salts of the above Preferred for use herein are the phosphates, carbonates, silicates, C . „ . „ fattv acids, polycarboxylates, and mixtures thereof More preferred are sodium tπpolyphosphate, tetrasodium pyrophosphate, citrate, tartrate mono- and di-succinates, sodium silicate, and mixtures thereof (see below) Specific examples of inorganic phosphate builders are sodium and potassium tπpolyphosphate, pyrophosphate, polymenc metaphosphate having a degree of polymeπzation of from about 6 to 21, and orthophosphates Examples of polyphosphonate builders are the sodium and potassium salts of ethylene diphosphonic acid, the sodium and potassium salts of ethane 1-hydroxy-l , 1 -diphosphonic acid and the sodium and potassium salts of ethane, 1, 1,2-tnphosphonιc acid Other phosphorus builder compounds are disclosed in U S Patents 3, 159,581, 3,213,030, 3,422,021 , 3,422, 137, 3,400, 176 and 3,400, 148, all of which are incorporated herein by reference Examples of nonphosphorus, inorganic builders are sodium and potassium carbonate, bicarbonate, sesquicarbonate, tetraborate decahydrate, and silicates having a weight ratio of SiO- to alkali metal oxide of from about 0 5 to about 4 0, preferably from about 1 0 to about 2 4 Water-soluble, nonphosphorus organic builders useful herein include the vaπous alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates and polyhydroxy sulfonates Examples of polyacetate and polycarboxylate builders are the sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylene diamine tetraacetic acid, nitπlotπacetic acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, and citπc acid Polymenc polycarboxylate builders are set forth in U S Patent 3,308,067, Diehl, issued March 7, 1967, the disclosure of which is incorporated herein by reference Such mateπals include the water-soluble salts of homo- and copolymers of aliphatic carboxyhc acids such as maleic acid, itaconic acid, mesaconic acid, fumaπc acid, aconitic acid, citraconic acid and methylenemalonic acid Some of these mateπals are useful as the water-soluble anionic polymer as hereinafter descπbed, but only if in intimate admixture with the nonsoap anionic surfactant Other suitable polycarboxylates for use herein are the polyacetal carboxylates descπbed in U S Patent 4, 144,226, issued March 13, 1979 to Crutchfield et al , and U S Patent 4,246,495, issued March 27, 1979 to Crutchfield et al , both of which are incorporated herein by reference These polyacetal carboxylates can be prepared by bπngtng together under polymeπzation conditions an ester of glvoxvlic acid and a polymeπzation initiator The resulting polyacetal carboxylate ester is then attached to chemically stable end groups to stabilize the polyacetal carboxylate against rapid depolymeπzation in alkaline solution, converted to the corresponding salt, and added to a detergent composition Particularly preferred polycarboxylate builders are the ether carboxylate builder compositions compπsmg a combination of tartrate monosuccmate and tartrate disuccmate descπbed in U S Patent 4,663,071, Bush et al , issued May 5, 1987, the disclosure of which is incorporated herein by reference Water-soluble silicate solids represented by the formula SιO ? »M-0, M being an alkali metal, and having a SιO_ M_0 weight ratio of from about 0 5 to about 4 0, are useful salts in the detergent granules of the invention at levels of from about 2% to about 15% on an anhydrous weight basis, preferably from about 3% to about 8% Anhydrous or hvdrated particulate silicate can be utilized, as well Any number of additional ingredients can also be included as components in the granular detergent composition These include odier detergency builders, bleaches, bleach activators, suds boosters or suds suppressors, anti-tamish and anti-corrosion agents, soil suspending agents, soil release agents, germicides, pH adjusting agents, nonbuilder alkalinity sources, chelating agents, smectite clays, enzymes, enzyme-stabilizing agents and perfumes See U S Patent 3,936,537, issued February 3, 1976 to Baskerville, Jr et al , incorporated herein by reference Bleaching agents and activators are descπbed in U S Patent 4,412,934, Chung et al , issued November 1, 1983, and in U S Patent 4,483,781, Hartman, issued November 20, 1984, both of which are incorporated herein by reference Chelating agents are also descπbed in U S Patent 4,663,071, Bush et al , from Column 17, line 54 through Column 18, line 68, incorporated herein by reference Suds modifiers are also optional ingredients and are descπbed m U S Patents 3,933,672, issued January 20, 1976 to Bartoletta et al , and 4, 136,045, issued January 23, 1979 to Gault et al , both incorporated herein by reference Suitable smectite clays for use herein are descπbed in U S Patent 4,762,645, Tucker et al , issued August 9, 1988, Column 6, line 3 through Column 7, line 24, incorporated herein by reference Suitable additional detergency builders for use herein are enumerated in the Baskerville patent, Column 13, l e 54 through Column 16, line 16, and in U S Patent 4,663,071, Bush et al , issued May 5, 1987, both incorporated herein by reference Additionally, the process of the present mvention can also include a step whereby a flow aid is added to the detergent admix to further improve flow properties Typical flow aids mclude zeolite, fine carbonate, and fumed silicas When used m the process herein, flow aids may compπse from about 0 1% to about 30% by weight of me particulate detergent admix, preferably from about 5% to about 25%, most preferably from about 10% to about 20% The following examples illustrate the advantages of the process herein Examples I, II, and III show processes wherein sorbitan esters are employed m a detergent admix without structuπng agents The admixes of Examples I, II, and III have physical properties which make them unacceptable for incorporation into detergent products Examples IV and V show a process wherein polyethoxylated and nonethoxylated sorbitan esters are combined with a structuπng agent to make a free-flowing particulate detergent admix The admixes of Examples IV and V have excellent physical properties for inclusion in detergent products EXAMPLE I Polyoxyethylene (20) sorbitan tπstearate (GLYCOSPERSE TS-20, purchased from Lonza Inc ) was melted at a temperature greater than it's melting point to form a liquid The liquid was then spread out onto aluminum foil to form a thin sheet approximately 1 - 2 mm thick, and allowed to cool to a room temperature of 21 1 °C Upon cooling, the thin sheet of liquid sorbitan ester solidified After solidification, the thin sheet was removed from the aluminum foil and granulated in a CUISINART food processor The granulated admix particles were screened using a Tyler 10 mesh screen having screen openings of 1 70 mm The admix particles produced by the above process had unacceptable properties for inclusion in detergent products The particles were soft, slightly sticky, and remelted into a single mass after aging for 3 davs at room temperature EXAMPLE II Polyoxyethylene (20) sorbitan monostearate (GLYCOSPERSE S-20, purchased from Lonza Inc ) was melted at a temperature greater than it's melting point to form a liquid The liquid was then spread out onto aluminum foil to form a thin sheet approximately 1 - 2 mm thick, and allowed to cool to a room temperature of 21 1 °C Upon cooling, the thin sheet of liquid sorbitan ester solidified After solidification, the thin sheet was removed from the alummum foil and granulated in a CUISINART food processor The granulated admix particles were screened using a Tyler 10 mesh screen having screen openings of 1 70 mm The admix particles produced by the above process had unacceptable properties for inclusion in detergent products The particles were soft, slightly sticky, and remelted into a single mass after aging for 3 days at room temperature EXAMPLE HI Polyoxyethylene (20) sorbitan tπstearate (GLYCOSPERSE TS-20, purchased from Lonza Inc ) and sorbitan monostearate (LONZEST SMS, purchased from Lonza Inc ) were separately melted at temperatures greater than their melting points to form liquids A mixture was then formed of 75% by weight of the liquid polyoxyethylene (20) sorbitan tπstearate and 25% by weight of the liquid sorbitan monostearate The liquid mixture was then spread out onto aluminum foil to form a dim sheet approximately 1 - 2 mm thick, and allowed to cool to a room temperature of 21 1 °C Upon cooling, the thin sheet of liquid sorbitan ester mixture solidified After solidification, the thin sheet was removed from the aluminum foil and granulated in a CUISINART food processor The granulated admix particles were screened using a Tyler 10 mesh screen having screen openings of 1 70 mm The admix particles produced by the above process had unacceptable properties for inclusion in detergent products The particles were slightly sticky and showed some caking upon extended storage Further, the caking which occurred did not break-up easily The composition of the admix particles produced by the above-descπbed process is presented in Table I TABLE I Detergent Admix Component (% Weight) Polyoxyethylene (20) sorbitan tπstearate 1 75 0 Sorbitan monostearate^ 25.0 Total 100 0 Manufactured under the trade name GLYCOSPERSE TS-20 by Lonza, Inc Manufactured under the trade name LONZEST SMS by Lonza, Inc EXAMPLE IV Polyoxyethylene (20) sorbitan tπstearate (GLYCOSPERSE TS-20, purchased from Lonza Inc ), sorbitan monostearate (LONZEST SMS, purchased from Lonza Inc ), and polyethylene glycol (CARBOWAX PEG 8000, purchased from Union Carbide, Co ) were separately melted at temperatures greater than their meltmg points to form liquids A mixture was then formed of 56 25% by weight of the liquid polyoxyethylene (20) sorbitan tπstearate, 18 75%) by weight of the liquid sorbitan monostearate, and 25% by weight of the polyethylene glycol The liquid mixture was then spread out onto aluminum foil to form a thin sheet approximately 1 - 2 mm thick, and allowed to cool to a room temperature of 21.1 °C Upon cooling, the thin sheet of the mixture solidified After solidification, the thin sheet was removed from the aluminum foil and granulated in a CUISINART food processor The granulated admix particles were screened using a Tyler 10 mesh screen having screen openings of 1 70 mm The admix particles produced by the above process had acceptable properties for inclusion in detergent products The particles were free-flowing and showed little caking upon extended storage Further, what caking that did occur after extended storage was easily broken by minor disturbance of the admix The composition of the admix particles produced by the above-descπbed process is presented in Table II TABLE II Detergent Admix Component (% Weight) Polyoxyethylene sorbitan tπstearate 56 25 Sorbitan monostearate^ 18 75 Polyethylene glyco 25.0 Total 100.0 Manufactured under the trade name GLYCOSPERSE TS-20 by Lonza. Inc. • Manufactured under the trade name LONZEST SMS by Lonza, Inc. Manufactured under the trade name CARBOWAX 8000 by Union Carbide, Co. EXAMPLE V Polyoxyethylene (20) sorbitan tristearate (GLYCOSPERSE TS-20, purchased from Lonza Inc.), sorbitan monostearate (LONZEST SMS, purchased from Lonza Inc.), and polyethylene glycol (CARBOWAX PEG 8000, purchased from Union Carbide, Co.) were separately melted at temperatures greater than their melting points to form liquids. A mixture was then formed of 25% by weight of the liquid polyoxyethylene (20) sorbitan tπstearate, 25% by weight of the liquid sorbitan monostearate, and 50% by weight of the polyethylene glycol. The liquid mixture was then spread out onto aluminum foil to form a thin sheet approximately 1 - 2 mm thick, and allowed to cool to a room temperature of 21.1 °C. Upon cooling, the thin sheet of the mixture solidified. After solidification, the tiiin sheet was removed from the aluminum foil and granulated in a CUISINART food processor. The granulated admix particles were screened using a Tyler 10 mesh screen having screen openings of 1.70 mm. The. admix particles produced by the above process had excellent properties for inclusion in detergent products. The particles were free-flowing and showed extremely little caking upon extended storage. Further, what little caking that did occur after extended storage was easily broken by minor disturbance of the admix. The composition of the admix particles produced by the above-described process is presented in Table III: TABLE III Detergent Admix Component (% Weight) Polyoxyediylene sorbitan tristearate I 25.0 Sorbitan monostearate^ 25.0 Polyethylene glyco 50.0 Total 100.0 Manufactured under the trade name GLYCOSPERSE TS-20 by Lonza, Inc. Manufactured under the trade name LONZEST SMS by Lonza, Inc. 3 Manufactured under the trade name CARBOWAX 8000 by Union Carbide, Co. Having thus described the process in detail, it will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the process is not to be considered limited to what is described in the specification.

Claims: WHAT IS CLAIMED IS: 1. A process for making a free-flowing particulate detergent admix for inclusion in a granular detergent composition characterized by the steps of: a) mixing a sorbitan ester with a structuring agent having a meltmg point above room temperature at a temperature sufficient to form a molten mixture, said sorbitan ester having the formula: wherein W+X+Y+Z equals from 0 to 40, R! is (C n H 2n+1 )COO, R 2 is (OH) or (C n H2 n +ι)COO, and n is an integer of from 11 to 17; and b) treating the molten mixture so as to form the particulate detergent admix. 2. A process according to claim 1, wherein the sorbitan ester is selected from the group consisting of polyethoxylated esters, nonethoxylated esters, and mixtures thereof. 3. A process according to claim 2, wherein the polyethoxylated ester is polyethoxylated sorbitan tristearate having a degree of ethoxylation of twenty, wherein R [ and R 2 are (C n H 2n +ι)COO, n is 17, and W+X+Y+Z equals 20, and d e nonethoxylated ester is sorbitan monostearate, wherein R j is (C n H 2n+ ι)COO, n is 17, R 2 is (OH), and W+X+Y+Z equals 0. 4. A process according to claim 2, wherein the weight ratio of the polyethoxylated ester to the nonethoxylated ester is from 0.1 : 1.0 to 5.0: 1.0. 5. A process according to any of claims 1-4, wherein the structuring agent is polyethylene glycol. 6. A process according to any of claims 1-5, wherein die molecular weight of the polyethylene glycol is from 1,500 to 100,000. 7. A process according to any of claims 1-6, wherein the mean particle size of the particulate detergent admix is from 100 microns to 2000 microns. 8. A process according to any of claims 1-7, wherein the sorbitan ester is characterized by from 5% to 80%) by weight of die particulate detergent admix. 9. A process according to any of claims 1-8, wherein the structuring agent is characterized by from 20%) to 95%o by weight of the particulate detergent admix. 10. A process according to any of claims 1-9, wherein the melting point of the molten mixture is greater than 37.8 °C.

Inventors: BOWMAN JOHN PATRICK, JOLICOEUR JOHN MICHAEL, BOWMAN, JOHN, PATRICK, JOLICOEUR, JOHN, MICHAEL
Applicants: PROCTER & GAMBLE, THE PROCTER & GAMBLE COMPANY
Application year: 1998
Main classification: C11D17
IPC codes: C11D1, C11D11, C11D17