CA1037817A - Particulate silicate-hydroxyalkyl iminodiacetate built detergent compositions of improved properties - Google Patents

Abstract

ABSTRACT
A particulate heavy duty synthetic organic detergent which has improved aging properties includes a synthetic organic detergent of the anionic or nonionic type or a mixture thereof and a builder which is a hydroxy-alkyl iminodicarboxylate hydrate. In preferred compositions the iminodicar-boxylate hydrate is disodium 2-hydroxyethyl iminodiacetate hexahydrate, the detergent is a mixture of linear higher alkyl benzene sulfonate and higher fatty alcohol polyethoxylate and the detergent composition includes sodium silicate, sodium carbonate, sodium carboxymethyl cellulose, sodium sulfate and moisture. The described products are of better storage and aging propert-ies than products of similar formulas in which the iminodicarboxylate is present but not as a hydrate. Also within the invention are methods for the manufacture of the described compositions in which all the formula except the iminodicarboxylate hydrate is spray dried from an aqueous crutcher mix to globular particles which are then mixed with iminodicarboxylate hydrate part-icles of similar sizes.

Description

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10378~7 This invention relates to heavy duty synthetic organic detergent compositions and methods for their manufacture. More particularly, it is of such detergent compositions which are of reduced caking tendencies despite their contents of an iminodicarboxylate builder salt which would normally be expected to cause caking of the detergent or aging.
Synthetic organic detergent compositions, whether based on anionic or nonionic organic detergent products, usually include a builder salt to improve detergency. Various phosphates, borax compounds, carbonates and silicates have been found to have building properties and of these, the phos-phates, especially pentasodium tripolyphosphate, until recent years was ack-nowledged to be far superior. However, due to opinions that phosphates in detergents contribute to eutrophication of inland waters, causing excessive algae growths, and because of government regulations, efforts have been made to produce non-phosphate detergents including substitutes for pentasodium tripolyphosphate. One such substitute, trisodium nitrilotriacetate (NTA), is not being used in the United States because of an interpretation of certain test results as indicating that it would, under certain circumstances, be carcinogenic.
Experiments have been run using iminodicarboxylates as builders for anionic and nonionic detergents in non-phosphate compositions and while such materials allow the production of detergents which wash satisfactorily, they possess other disatvantages which have interfered with their large scale acceptance. In United States Patent No. 3,953,379 (Colgate) issued April 27th, ;
1976, entitled MANUFACTURE OF IMPROVED AQUEOUS ALKALI METAL SILICATE-ALKALI
METAL HYDROXYALKYL IMINODIACETATE COMPOSITIONS, filed by me concurrently with the present application, a method of avoiding production of gels and precipi-tates when admixing iminodicarboxylates and silicate components of detergent composition has been described. In addition to the gelation or precipitation ~
problem it has also been noted that the iminodicarboxylates tend to become ;
tacky or to cake on storage, possibly due to hydrate formation. Therefore, the product used by the consumer may be in unacceptable physical condition, ~;~
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10378~7 being caked into a solid or exhibiting a lumpy appearance. Accordingly, efforts have been made to improve the caking and flow properties of such detergents, leading to the discovery of the present solution which, sur-prisingly, allows the production of the desired phosphate-free built heavy duty detergent compositions based on iminodicarboxylate builder salts by utilization of a hydrate of such iminodicarboxylate and post addition thereof to the rest of the detergent composition.
In accordance with the present invention there is provided a parti- - -culate heavy duty synthetic organic detergent composition which comprises 5 to 30 parts of anionic detergent and/or 1 to 10 parts of nonionic detergent and, as a builder therefor, 15 to 50 parts of a water-soluble salt of a hydroxy C2-C4 alkyl iminodi C2-C4 carboxylic acid hydrated by 3 to 10 moles of water per mole of iminodicarboxylate.
In another aspect, the invention provides a method of making a free flowing, particulate heavy dùty synthetic organic detergent composition which comprises 5 to 30 parts of anionic detergent and/or 1-10 parts of nonionic ;-detergent and, as a builder therefor, 15 to 50 parts of a water-soluble salt of a hydroxy C2-C4 alkyl iminodi C2-C4 carboxylic acid hydrated by 3 to 10 moles of water per mole of iminodicarboxylate, which comprises making particles of the heavy duty synthetic organic detergent composition components exclusive of the said builder salt and admixing with them particles of said builder salt hydrate.
The detergent compositions of the present invention include as a primary detersive constituent an anionic synthetic organic detergent or a ,...

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nonionic organic detergent but preferably, these are employed in mixture.
The anionic detergent may include the various materials listed in that cate-gory, as described in McCutcheon's Detergents and Emulsifiers 1969 Annual, in which such compounds are listed by chemical formulas and trade names. They may also include those anionic detergents described in the text Surface Active Agents and Detergents, Vol. II, by Schwartz, Perry and Berch tInterscience Publishers, 1958). In short, such materials include hydrophilic and lipophilic groupings, the lipophilic portions whereof normally contain a higher hydro-carbyl chain, usually of 10 to 20 carbon atoms and the hydrophilic portions of which include a salt-forming ion, preferably an alkali metal salt. Most of such useful detergents are sulfates or sulfonates but corresponding phos-phates, phosphonates and other suitable detergent salts are also useful.
Included among the anionic detergents, for example, are the linear higher alkyl benzene sulfonates, the branched chain higher alkyl benzene sulfonates (although these are not usually sufficiently bio-degradable to be acceptable in modern detergent formulations), the higher fatty alkyl sulfates, the higher ; fatty acid monoglyceride sulfates, the higher olefin sulfonates, the higher alkyl sulfonates, tho sulfated phenoxy polyethoxyothanols, the sulfated higher fatty alcohol poly-lower alkoxy alkanols, paraffin sulfonates and the corre sponding phosphates and phosphonates. The hydrocarbyls, alkyls and higher fatty acyl groups of such compounds will generally be of 12 to 18 carbon atoms and tho salt-forming ions theroof will preferably be alkali metal, although alkanolamines and alkylamines may also be utilized. The sulfated nonionics ; are preferably those in which the alkyls are of two or three carbon atoms per unit. Specific exemplifications of such compounds include sodium linear tri-decyl benzene sulfonate; triethanolamine lauryl sulfate; potassium stoarate;
sodium phenoxy polyethoxyethanol wherein the polyethoxyethanol chain is of 15 units; sodium coconut oil fatty acits monoglyceride sulfate; and potassium tallow sulfonate. Of these materials it is highly preferred to employ the . .. . .
linear higher alkyl bonzeno sulfonates wherein the alkyls aro of 12 to 15 ~

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carbon atoms, most preferably about 13 carbon atoms, and in which the salt- -forming ion is alkali metal, preferably sodium. The sodium salts tend to make harder detergent products which are more freely flowing than those of the alkylamines, alkanolamines and potassium. They also tend to cake less.
Instead of the anionic detergents or in addition to them nonionic detergents may also be utilized. These include condensation products of higher fatty alcohols with polyoxy-lower alkylene glycols, such as Neodol ;~
(trademark) 45-11, Plurafac~trademark) B-26 and Alfonic(trademark) 1618-65.
.
Also useful, normally as a proportion of a nonionic detergent content, are Neodols(trademark) 25-3 and 25-7. Such compounds are hydroxy-containing linear polymers of lower (1-4 C's) alkylene oxides and are normally liquid or ;
somi-solid at room temperature. Also useful are the block copolymers of pro-pylene glycol, propylene oxide and ethylene oxide, such as the Pluronics (trademark), e.g., Pluronic(trademark) L-44 and Pluronic(trademark) F-68; and the middle alkyl phenyl polyoxyethylene ethanols, such as those sold as Igepals(trademark). Normally, the content of nonionic detergents, such as those which are condensation products of higher fatty alcohol and alkylene oxide, e.g., the Neodols(trademark) of 12 to 15 carbon atoms in the higher fatty alcohol and including from 3 to 15 moles of alkylene oxide per mole of fatty alcohol, will be less than the anionic detorgent content of the product and preferably will bo about ono-half or less of such content, e.g., 10 to 50% thoroof.
Although the anionic detergents may be employed alone and solid forms of nonionic detergents may be utilized by themselves, the nonionic detergents are normally liquid or pasty in nature and do not make as satis-factory primary detorgent constituents as the anionic compounds. Yet, they do contribute desirable cleaning properties and accordingly, are preferably employed in admixture with the anionic detergents, normally with the nonionic : component being present to a greater extent.
An important constituent of the detergents is the alkali metal sill-~ '; ,.

1037~17 cate component. Such compounds are water soluble and are useful as builders for the synthetic organic detergents. They exert alkalizing effects, help to counteract water hardness and have both an independent detersive effect and the property of improving the effect of the anionic and nonionic detergents utilized, especially when these are employed in mixture. When the particular higher fatty alcohol - poly-lower alkylene oxide nonionic detergent condens-ates of the present invention are employed with the silicates and linear higher alkyl benzene sulfonates a product can be made which is comparable to previously highly superior phosphate-built linear alkyl benzene sulfonate ~lAS) compositions. Additionally, the silicates have a corrosion inhibiting effect.
The silicates employed are water soluble. Of the inorganic sili-cates those which are water soluble are the silicates of alkali metals, e.g., sodium, potassium. Silicates of M20:SiO2 ratios are available in the range of 1:1 to 1:4 but for practical purposes those which are used for detergent compositions are generally of such ratios of 1:1.6 to 1:3, preferably 1:2 to - 1:2.4 ant most preferably about 1:2Ø In the procoding formulas M stands for alkali metal, preferably sodium or pOtasSiuQ. The sodium silicates are proferred for use in solid or particulate detergent products and the potassium silicates are generally preferred in liquid compositions, although, especially i~ whon mixtures are utilized, either may be employed in both types of composit-ions.
The various silicates describod are usually supplied as aqueous solutions although it is within the present invention to employ solid or particulate silicates too, normally after dissolving them in water. The con-contrations of the aquoous solutions will usually be those which are as high -~
as possible and at which tho solution is readily pumpable. Normally, from 20 to 50% by weight of sodium silicate will be employed, preferably from 35 ,. , to 45% by weight thereof. With respect to a preferred silicate, that of `~
Na20:SiO2 ratio of 1:2.4, tho concentration will most preferably bo from 40 .. : .

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Another detergent builder found to be highly dosirable in the non- -tacky and free flowing particulate compositions is alkali metal carbonate.
This will normally be utilized in the anhydrous form but hydrates such as washing soda may also be employed, providing that the excess moisture will be removed therefrom during the drying process. Alkali metal sesquicarbonates - -and bicarbonates may be employed as substitutes for the carbonates providing -~that the crutching and drying operations will essentially convert these to the alkali metal carbonate. Of the alkali metals, e.g., sodium, potassium, ~
it is generally preferable to employ the sodium salt. Sodium carbonate has ;
the useful effects of increasing the pH of the crutchor mix before spray drying and of giving the detergent product and the wash water desirable high pH's. It also helps to improve product flow and storage properties, serving to sorb moisture without objectionable caking.
To improve the cleaning power of the detorgent and to help to main-tain the beads in smooth, regular, globular and stable form an organic gum anti-redeposition agent such as sodium carboxymethyl collulose, polyvinyl ; alcohol, hydroxymethyl ethyl cellulose, polyvinyl pyrrolidone, polyacrylamide or hydroxypropyl ethyl collulose or mixturos theroof may be utilized. Such matorials are well known in the art ant other oquivalents neod not be de-scribod at length hore.
Also of importanco in improving flowability of detergent particles, in addition to the carbonates, are tho filler salts, which are often used.
Thoso includo primarily sodium sulfate and sodium chlorido, although other -such alkali metal sulfatoslchlorides, nitratos, borates, acetates, gluconates, citratos and many othor water solublo salts may be employed as fillers and in somo cases may havo additional functions in the dotergent, e.g., sequest-ering, solubilizing and bufforing actions. Finally, suitable adjuvants may ; also be utilized such as sanitizers, e.g., trichlorocarbanalide; coloring agents, e.g., dyes and pigments; foam improvers, e.g., lauric diethanolamide;

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foam depressants, e.g., silicones; fungicides, e.g., polyhalosalicylanilides;
antioxidants, e.g., stannic chloride; stabilizers; chelating agents; optical bleaches or fluorescent brighteners; solvents; hydrotropes; and perfumes.
The materials previously described may for the most part be com-pounded together in a mixture and spray dried into homogeneous detergent beads absent any iminodicarboxylate. In some cases it may be desirable to post-add some of these materials or proportions thereof and such processing method will be described at greater length later herein.
The iminodicarboxylate compounds of this invention are water sol-uble hydroxy~lkyl iminodicarboxylates wherein the carboxyls are of 2 to 4 carbon atoms, preferably 2 to 3 carbon atoms and most preferably from acetic acid. Such materials are found to be excellent builders for synthetic organic detergents and have desirable sequestering effects against water hardness ions, such calcium and magnesium, which might otherwiso interfere with deter-sive actions of the organic detergont. The hydroxyalkyl iminodiac~tates generally employet are alkali metal salts, usually diacetates, although other solubilizing cations may also be present, at least in partial substitution for the alkali metal salts. Of the alkali metal salts the sodium and potass-ium salts are preferret, with the sodium salt being that of greater preference for solid or particulate compositions and the potassium salts being better for liquid preparations. Exemplary of other solubilizing cations are mono-, ; -ti- ant tri-alkanolammonium ant mono-, ti- and trialkylammonium, where the alkyls ant alkanols are lower, usually of 1 to 4 carbon atoms ant preferably .
of 1 to 3 carbon atoms, most preferably being of 2 carbon atoms. Examples :
of such materials are ti-triothanolammonium 2-hydroxy-ethyl iminodiacetate -ant di-monoisopropylammonium 3-hytroxypropyl-N-iminotiacetate. Di-ammonium `
iminotiacetates substitutet with the hytroxyalkyls are also used.
The hydroxyalkyl of the hydroxyalkyl iminodiacetate is hydroxy-lower alkyl wherein the lowor alkyl is of 1 to 4 carbon atoms, preforably of : . ,

2 to 3 carbon atoms and most preforably, ethanol. Although the hydroxyl needs , .. , . , : .

-1037~17 not be terminal on the ethyl, for best effects this positioning is desirable.
Although the described iminodicarboxylates are available in solut- ~ -ions and sometimes as anhydrous solids and are useful in such forms in various detergent compositions or processes, in accordance with the present invention it is important that the anhydrous form not be utilized and that the iminodi-carboxylates be present in the final detergent compositions as hydrates.
Such hydrates are usually polyhydrates, of which the most preferred is disod-ium 2-hydroxyethyl iminodiacetate hexahydrate. Generally, the various poly-hydrates will contain from 3 to 10 moles of water per mole of iminodicarboxy- ;
late.
The non-iminodiacetate portion of the detergent composition will usually comprise from 5 to 30 parts of the anionic detergent and/or 1 to 10 parts of nonionic detergent, 5 to 30 parts of alkali metal silicate, 4 to 20 parts of alkali metal carbonate, 0.3 to 3 parts of organic gum anti-redeposit-ion agent, 1 to 20 parts of moisture and 5 to 40 parts of alkali metal sulfate and/or alkali metal chloride in tho particles or spray dried beads thereof.
The proportions of adjuvants and supplementing materials present in such beads will usually not exceed 20% of the total composition (including iminodiacet-ato), normally will be loss than 10% and preferably will be less than 5%
thoreof, with nono of the constituents boing moro than 5~, preferably with each being less than 2% and most preferably, less than 1% thereof. Of course, some of tho loss stablo components of the particular detergents or those ~-- which might interfero with drying or flow properties if driod with the major ~-proportion of detergent composition, may be added after drying is comploted.
Mbst preferred proportions land materials are from 5 to 30 parts of sodium linear highor alkyl benzene sulfonate, 1 to 8 parts of higher fatty alcohol poly-lower alkoxylato dotergont, 5 to 30 parts of a sodium silicate of an Na20:SiO2 ratio in tho range of 1:2.0 to 1:2.4, 4 to 20 parts of sodium carb-onate, 0.3 to 3 parts of sodium carboxymethyl cellulose, 1 to 10 parts of moisture and 5 to 40 parts of sodium sulfate.

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The other component of the final detergent product, the iminodi-carboxylate hydrate, should usually constitute about 15 to 50 parts, prefer-ably 20 to 40 parts thereof. Such material, most preferably disodium-2-hydroxyethyl iminodiacetate hexahydrate, may be in separate pure iminodicar-boxylate particles or may have filler salts or other suitable such components of the total composition mixed with it. Generally, it is preferred that the pure iminodicarboxylate material should be utilized. In some instances some of the iminodicarboxylate may be in the major proportion of the detergent even in anhydrous or lower hydrate form but for better flow and caking prop-erties this should be only a minor proportion of tho total iminodicarboxylate builder content, e.g., less than 30%.
To avoid separation during storage and shipment, it is highly desirable that the particles of detergent composition constituents and those of iminodicarboxylate hydrate should be of about equal particle sizes. Al- -though various ranges of particle sizes utilized in the detergent industry ~ :
may be employed it has been found that it is preferable that the particles be in the 6 to 140 mesh range, U.S. Standard Sieve Series, preferably from ;~ I
6 to 100 mesh. That means that the particles will pass through the 6 or 8 mesh sieve and rest on the 100 or 140 mesh sieve. With particles of such sizos and of approximately the same particle sizo distribution little settling rosults and the finishod detergent is flowablo and of an acceptable degree of tackiness and tendoncy to cake in contrast to similar compositions in which the non-hydrated iminodicarboxylate is employed or in which an iminodicarboxy- ~-late solution is spray dried or otherwise dried with the rest of the detergent composition. I
The products of this invention are preferably made by spray drying most of the detergent compositions, except for the hydroxyalkyl iminodicarboxy-late, in a conventional spray drying apparatus so as to produce beads of the desired particle sizes, 6 to 140 and preferably 8 to 100 mesh. Such a spray operation is usually effected by crutching an aqueous mixture of the various . ' ~.: ' .
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components at an elevated temperature, e.g., 50 to 90C. for a suitable period of time, e.g., three minutes to one hour, and then forcing the crutcher mix at high pressure, e.g., 200 to 1,000 lbs./sg, in., through restricted orifices so as to result in a production of a spray of crutcher mix droplets into a spray tower in which the droplets fall while being contacted by a countercurrent hot air flow, which dries them. The crutcher mix will usually contain from 20 to 50% of water and may include some small solid particles which are pumpable through the spray orifices at the high pressure. The orifices will be of a cross-section equivalent to a circular area of 1 to 5 millimeters in diameter. The drying air entering the spray drying tower will be of an initial temperature in the range of 200 to 500C. and at exit from the tower will usually be at a temperaturo of 110 to 200C. The detergent particles removed will be of a moisture content of 1 to 20% and more often ; will be 15% or less in moisture. The drying operation will be controlled, as by drying gas temperatures and tower throughput rates, to make detergent beads of such moisture contents that togethor with the moisture in the imino-dicarboxylate hytrate the moisture of the product will be in the 1 to 20%
range, preferably 1 to 15% and most preferably about 1 to 10%. ~
The spray nozzle sizes and spraying pressures or atomizing means employed will be chosen so as to protuco particles of the desired sizes for tetorgent compositions. Oversize ant fino particlos may be removod by screon-ing or othor classification tochnique so that tho product is correctly sizod.
Such off-sizo particles may be sizo-roducot or reworkod so as to a~oid wasto.
In the crutching oporation the order of addition of the montioned compononts is not critical but it is proferrod to dissolve the anti-redoposit-ion agent gum in water or in an aqueous solution of other constituent before attition to tho main crutcher mix, to avoid lumping or the protuction of hard gel soctions in the crutcher mix. Gonerally, wator, liquid detergent, anionic detergent solution, silicate solution and carbonato may bo added in that ordor, followed by tho um solution or disporsion and various hoat stable , , .

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10378~7 adjuvants. Any components which exhibit an undesirable reaction to the hoat of the crutcher or the spray drying operation are preferably post-added.
In some cases proportions of components are crutched and the remain-ders are post-added. For example, it has been found that larger proportions of nonionic detergents, silicate and anti-redeposition gum than 2% of the detergent (Neodol(trademark) 45-11), 15% of sodium silicate and 0.5% of carb-oxymethyl cellulose, on a final product anhydrous basis, may interfore with drying, flow and non-caking properties of the product. Therefore, such -materials will be preferably limited in the crutcher mix to the amounts ment- ~ :
ionod. However, additional nonionic detergent or surface active agent and ~ ;
aqueous solution of sodium silicate may be sprayed onto particles after manu-facture and additional sodium carboxymethyl collulose or other gum, in powder-ed form, may be admixed with them. These oporations preferably take place in : :
a tumbling drum shortly after production of the detergent boads. Such tumbl-ing is preferably at room temperature but is suitably offected at tomperatures above that, e.g., 30 to 50C.
The extra operation of blending in powdered anti-redeposition agent may be avoided in the present processes by maintaining tho limit of anti~
redoposition agent at 0.5% or thoroabout. It has been noted that good anti-rodoposition effects are obtainod with such small proportion of the agent, - apparontly duo to additional anti-redeposition proportios of the iminodicar-boxylato buildor in the prosent compositions.
Tho iminodicarboxylato hydrate is preforably in globule form and of tho samo sizo distribution as the spray dried particlos of tho othor dotorgent constituonts. Particles oflthis type may bo made by drying an iminodicarboxy-lato solution or slurry in convontional spray drying oquipment and then hydrating it by troating it with wator or by subjecting it to air of a relat-ive humidity about tho same as or higher than the oquilibrium humidity for tho hydrate. For examplo, when oxposod to a humidity of from 65 to 75% at room temperature, a proforred iminodicarboxylate, disodium 2-hydroxyethyl . :~ .
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1037~7 iminodiacetate, will take up moisture until it reaches the hexahydrate stage.
At relative humidities of 80% or more, which are rarely encountored, if by itself the hydrate may absorb water but in the present compositions sorption is minimized and caking problems are not common. Considering that almost all storage is at humidities less than 80% and at temperatures of 20 to 27C, the emplcyment of a hexahydrate in the present detergent compositions substant-ially prevents caking of the iminodicarboxylate and allows the production of a free flowing product.
Instead of adding moisture to the anhydrous form by subjocting spray beads to air of higher relative humidities, controlled addition of water -thereto may also be practiced. Solutions of the iminodicarboxylate may be spray cooled to the hexahydrate form while maintaining globular particle shapes. Alternatively, granular hexahydrate may be made in manners known in the art and the granules may be size-reduced to the proper particle size range, with oversize particles and fines being removed. In a less preferred application of the invention a powdered iminodicarboxylate hydrate may be employed. Although the use of the hexahydrate in this form avoids some of the caking problems noted with the anhydrous iminodicarboxylate particles it introduces a disparity in particle sizes which may, under extrome conditions, cause sifting or settling and could make a boxed dotergent product heterogen- -~
ous, so that poor washing effects would bo obtained because product employed would not havo the propor balanco of detersive and builder components. Such balance is important because tho iminodicarboxylates improve the cleaning powor of the organic detergents and other builders and with either an excess ~ ' or deficiency of tho iminod~carboxylato less desirable cleaning results. ;-Although the preferred forms of both the detergent base particles and tho iminodicarboxylate builder particlos are globular and in the particle size ranges montioned it is within the broader ambit of this invention to utilize more finely divided or powdered components. Normally, such components do not flow as readily and have a greater tendency to cake during storage and . , , ~ . .

so are not preferred but by using the process of this invention, with post-addition of the ~minodicarboxylate hydrate, improvements,in flow properties are obtained and there is le~s of a tendency toward caking. The "base"
powder is preferably produced by drying a mix of all the detergent components ~- -except the iminodicarboxylate but the use of individual powdered materials is also within the broad invention of improving flowability and caking properties by post-addition of the iminodicarboxylate hydrate. Of course, where components are liquid, they may either be mixed with powdered carriers ~
initially or may be blended with the powdered product at a later stage in the ~ -production. In some manufacturing processes a proportion, usually a minor proportion, generally less than 30%, of the iminodicarboxylate may be mixed in with the other detergent components before drying but there is generally little advantage in following such a procedure and it is highly preferred that the detergent "base" beads be free of iminodicarboxylate since such material can hydrate during storage and cause caking and poor flow. In fact, ~
post-adding of the iminodicarboxylate avoids a manufacturing problem for -which another solution is described in the aforementioned U.S. Patent No. 3,953,379. In short, the gelation or precipitation often noted when iminodicarboxylate and silicate are admixed is avoided by initially raising ~ 20 the pH of the iminodicarboxylate solution to above 12, preferably to 12.5 to ; 13.5.
The admixing of the detergent base beads or particles and the hydrated iminodicarboxylate may be effected by any convenient means, the most preferable of which is an inclined tumbling drum or a twin shell blender.
The main consideration is t~at the mixing apparatus should not unduly fragment ; the particles. In the mixing apparatus, as was previously indicated, other ,, .
components of the detergent composition may be added in liquid, droplet, powder or other form and additional quantities of components may be added.
In such cases it would be desirable to utilize materials of the same particle . ., 1 . ,, ,: . .

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'':' ' . :: .. - ' ' . : : ' sizes, whenever possible. Materials such as sodium carboxymethyl cellulose may be agglomerated to particles of the correct size, although it has been found acceptable to utilize this material, in the small proportion in which it is present, as a finely divided powder having particles in the range of 100 to 200 mesh. Preferably, all mixing, spraying and other forms of treat-ments in the mixer will be at about room temperature.
The iminodicarboxylate particles made are added to the base part-icles before or after addition of post-addition materials. The post-addition ~ ~ -substances may be added to either the iminodicarboxylate or the base composit-ion particles first and then the other component particles may be admixed.
In some instances, as where starting materials inclute fines or are of part-icle sizes smaller than desired, partial agglomeration may take place in the tumbling drum, aided by the application of solutions of gums or silicates, or nonionic detergents or surface active agents. In any such cases, care will be taken to maintain the particles in the tesired range of sizes and to prevent any dehydration of the iminodicarboxylate hydrate. ~ -After protuction of tho final detergent product it may be stored -prior to filling into cartons or may be directly filled. The cartons used may be of moisture barrier or non-barrier types and it has been found that in the ordinary, non-barrior cardboard cartons, storet at room temperature, tetergent compositions containing the post-atted hexahydrate are of a lesser tendency to cake on storage than similar protucts in which anhydrous imino-tiacetate is present (mate from a spray triet crutcher mix).
In use it is fount that the protucts are excellent tetergents, effectively washing out soills of the various types normally encounteret, such as particulate tclay) soils, sebum soils, greasy ant carbonaceous soils, from cotton and synthetic organic fiber-based materials and articles made from them. The iminoticarboxylate buildors function better in this respect than all of the builder substitutes for pentasodium tripolyphosphate and trisodium nitrilotriacetate that have been tried and the detersive, soil-suspending and .- , ~ . :
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whitening effects of the present detergent compositions are comparable to those obtained with phosphate-based formulations, evon at much higher levels of the phosphate (with compensating lower levels of synthetic organic deter-gent content). The products are competitive in price with other commercial detergent formulations. Additionally, they do not contain excessive quantit-ies of potentially toxic or harmful constituents.
The following examples illustrate the invention but do not limit it. Unless otherwise indicated, all parts are by weight and all temperatures are in C. ;
EXAMPL~ 1 Parts by weight * Highcr fatty alcohol poly-lower alkoxylate 5 nonionic surface active agent -** Higher fatty alcohol poly-lower alkoxylate 3 detergent Linear tridecyl benzene sulfonate, sodium salt 15 ~ -(90% active ingredient) Aqueous sodium silicate solution (Na O:SiO = 36 1:2.35; solids content = 244%) Sodium carbonate, anhydrous 13 Sodium carboxymethyl collulose 0.7 (85% active ingredient) Sodium sulfato 20 j --Water 7 * Neotol 25-3S, a trademark for a highor fatty alcohol polyisopropoxylate -mado by Sholl Chemical Company, whorein the higher fatty alcohol is of 12 to 15 carbon atoms and thoro are prosent throe moles of propylone oxide per mole of highor fatty alcohol. I
** Neodol 45-11, a tradomark for a highor fatty alcohol polyethoxylate made by Sholl Chomical Company, whoroin tho higher fatty alcohol is of 14 to 15 --carbon atoms and thore are presont olevon moles of othyleno oxido per mole of higher fatty alcohol.
About four parts of the water aro addet to a dotorgent composition .. ~ .

crutcher, followed by the silicate solution, sodium carbonate, anionic deter-gent, nonionic surface active agent, nonionic detergent, and sodium chloride and the contents are mixed over a period of about five minutes. The sodium carboxymethyl cellulose is dissolved and dispersed in the remaining water and the aqueous solution-dispersion is admixed with the rest of the crutcher mix.
After continuing mixing for an additional five minutes after all the materials are present in the crutcher the mix is pumped by a Triplex(trademark) pump at a pressure of 600 lbs./sq. in. through a plurality of spray noz~les, each of which has an orifice of about 1.5 millimeter diameter, into the top of a countercurrent spray drying tower wherein the falling troplets of detergent composition base are dried in heated drying air which passes upwardly through the tower. The drying air has an initial temperature of about 400C. and a final temperature of 130C. The dried beads have a moisture content of about

3%. The resulting product, in the form of spray dried globules, is screened and sized so the particles thereof pass through a No. 8 sieve, U.S. Standard Sieve Series, and rest on a No. 100 mesh sieve.
After removal from the spray tower and cooling to a temperature of about 40C., 100 parts of the spray driod tetergent base beads are added to a tumbling drum and 23 parts of disodium 2-hydroxyothyl iminodiacetate hexa-hydrato, in granular form of particle sizos in the 8 to 100 mesh range, are mixed with tumbling so as to evonly distribute them throughout the particulate msss. Noxt, 0.15% of porfumo is sprayot onto the particles and mixing is continuod until tho perfume is completely distributed, which takes about an additional minute beyond the fivo minutos oarlior mixing time.
In uso it is foun,d that the above composition is comparable in dotergoncy with high phosphate compositions basod on 10 to 25% of active . anionic totorgont and 30 to 45% of pontasodium tripolyphosphate. Yot, the r~
product is non-outrophying and doos not contain any phosphatos nor does it contain unusual quantitios of surfaco active agonts, detergonts, builders or anti-redeposition agents. Utilizing standard concentrations of dotergonts in .. .. . , . ,. - : - ~
- ' automatic washing machines, 0.15~ o~ the particulate detergent, the product is tested and found to be acceptable, good or superior in washing ability in ~i~
both hot and cold water, in both hard and soft water, and when tosted against varying types of soils, including clay soils, carbon soils, greasy soils, and phospholipid or sebum soils, as compared to phosphate-containing commercial detergents.
Compared to formulations in which the anhydrous disodium 2-hydroxy-ethyl iminotiacetate is employed instead of the hexahydrate (with the proport- -ions thereof being diminished to allow for the extra water content of the hexahydrate), the present products are of roduced caking tendency in non-barrier boxes or cartons when subjected to normal use and aging conditions.
They flow more freely than "control" compositions based on the anhydrous ~, iminodicarboxylate, after storage in ordinary non-barrier boxes at room temp-erature (20-27C.) and ordinary humidities (30-60%).
Variations in the formula to increaso or decrease the various com-ponents within the ranges previously given result in the productions of satisfactory tetergent compositions, which are of improved flowability and ;-- :-, -anti-caking properties, compared to control dotergents. Similarly, changes O
in the processing whereby an additional 15 parts of sodium silicate solution -;-aro sprayed onto the tumbling dotorgent boads and an additional 0.5% of ,;~
sodium carboxymethyl colluloso powdor, in finely divided form (100 to 200 mosh) is blondod in with tho product after application of the sodium silicate solution, also rosult in a product of improvod flowability and anti-caking prop~rtios, compared to tho control. In such co~positions the moisture con-~, ...
tont of tho base detorgentlbeads may bo roduced to 0.5 to 1~ initially, to componsato for tho additional moisture post-addod with the silicato solution.
When, in atdition to tho procossing changes described, tho Neodol 25-3S is omitted from the crutchor mix and tho samo proportion of Neodol 45-11, in liquid form, at an elovated temperaturo, is sprayod onto tho dotorgent and iminodicarboxylato beads aftor application of tho silicate, an equivalont , .
,; ,. , product is made. Such product avoids the problem of pluming from the spray tower of some of the nonionic surface active and detergent materials when higher nonionic content formulations (greater than 2%) are spray dried.
Replacement of the sodium sulfate with potassium sulfate or mixtures of sodium and potassium sulfates also makes a good product but it may tend to cake slightly more. Use of sodium chloride instead of sodium sulfate is acceptable when corrosion of metal equipment is no problem. The products are also satis-factory detergents against the various mentioned soils on the different types ~-of fabric substrates. , EXAMPLE 2 ~ -Parts Neodol 25-3S 4 Neotol 45-11 6 2 2 Sotium linear tridecyl 11 11 11 bonzene sulfonate Aqueous sotium silicate 15 12 12 solits (appliot as a solution with Na O:SiO =
1:2, solits contont = 244%) :,, Sotium carbonate, anhytrous 10 10 10 Moisture 4 4 4 Disotium 2-hydroxyethyl 15 12 25 iminotiacotate hoxahydrate Atjuvants (0.5 psrt sodium 2.3 2.3 2.3 carboxymothyl colluloso, 0.5 part calcinot alu~inum silicato flow-improving agont, 1.0~ fluorescont brightener mixture, 0.2%
perfume and 0.1% stabilizor) Sotium sulfato, anhytrous 36.7 42.7 33.7 Ropoatet exporimontation inticatos that the best concentrations for the sotium linear tritocyl benzone sulfonate, sodium silicate, sotium car-bonate, moisture ant atjuvants contents are about 11%, 12-15%, 10%, 4~ and 2-3%, respectivoly, with nonionic tetergent contents in 2 to 6% range and - - , ~ ' ~
. ~ -- . , ,., .- ~:
.-: - . . , - , ~:
,. - , .
;: --~037817 other anionic organic detergent contents of about O to 4%. Concentrations of iminodiacetate hexahydrate in the product are preferably in the 10 to 30%
range, preferably 12 to 25%.
The detergent compositions described above are made substantially as related in Example 1, with the spray drying of the intermediate products being effected after the described pre-mixing and with no more than 2% of -the Neodol(trademark) 45-11 being incorporated in the product during spray drying operations. The hexahydrate is post-added also, following the proced-ure of Example 1 and producing products of about the same size. In some experiments the nonionic detergent is completoly post-sprayed onto tho other particles, optionally with sodium carboxymethyl cellulose (or with it boing pre-mixed with the intermediate), and the calcined aluminum silicate is -dusted onto the product afterward. In other experiments a proportion of the nonionic detergent is post-sprayed and another proportion, up to 2% thereof, .. . .. .
- is spray dried with the balance of the dotergent composition formula. Con- ,~ :
trol runs are also made, using the iminodiacetate in the final product, hold-ing the final product moisture content essontially the same (except for hydrato moisturo). The iminodiacetate may be employed in any suitable form but usually will be the alkali metal salt (or as ions from such a salt) in the complotod crutcher mix.
Tho products msdo are compared for tackiness and caking. It is obsorvod that whon storod in normal containors, without barriors, under normal storage conditions (not oxcessively high temporatures), there is a noticoable improvoment in characteristics of tho final product. Control products, not utilizing thol hoxahydrate, cake significantly worse and are -much moro difficult to pour out of cartons. On the other hand, the composit-ions to which the hoxahydrate is post-adted, whother with post-addition of -nonionic dotergent or not, aro of improved aging characteristics. Although -thoy can somotimos produco noticoable lumping, they will flow much moro free-ly than tho "controls", after storago.

-19- ''' ' :

10.37817 When the formulations given above are changed, substituting the corresponding iminodipropionate or hydroxypropyl iminodiacetate, useful detergents are obtained for which the hydrated iminodialkanoates are of improved non-caking and subsequent flow properties. This is also the case when the previously named anionic detergents are substituted for the sum of ~ -the Neodol~trademark) 25-3S and sodium linear tridecyl benzene sulfonate and when proportions of these spocific detergents are halved and/or doubled.
Similarly, when Neodol(trademark) 45-11 is roplaced by Neodol~trademark) 25-7, in minor part or is partially or completely replaced by Plurafac(trademark) B-26, Alfonic(trademark) or Conoco(trademark) 1618-65, a mixture of Pluronics (trademark) L-44 and F-68 or other suitable nonionic detergent, essentially the same type of result is obtained. This is also true when in the various experiments described the proportion of carbonate is increased to 15% and when 5% of bicarbonate is added to the 10% of carbonato. Of course, changing of the silicates to Na20:SiO2 ratios of 1:2.35 and 1:2.2 yields essentially the same types of products, too.
Instead of the sodium salts, a minor proportion of the total of builder, dotergent and filler salts may bo replaced by the corresponding potassium salts without harm to the production of an acceptable product.
Although tho product obtainod is better than corresponding non-phosphate built detergents that are allowed to be marketed in the United States, with respoct to cleaning and brightening abilities, as shown in com-parativo tostings against controls containing no iminoalkanoate, and although thoro is a decited improvomont in subsequent flow and aging properties in non-barrier boxes on ordinajry storage, offorts are being made to improve the aging charactoristics of tho dotorgent further, to which end starch or other additional flow improving agont may bo utilized and, in some cases, tho iminodialkanoate, eithor as a hydrate or as a mixture thereof with the corre-sponding anhydrous form, may bo at loast partially oncapsulated to further diminish any tendency toward caking or lazy flow after packaging.

The formulation of Example 2-3 is followed with the exception that .
the proportion of sulfate is diminished 5% and that of the hydroxyethyl imino-diacetate hexahydrate is increased 5% and the iminodiacetate and nonionic detergent are post-sprayed onto and post-mixed with the rest of the previously spray dried detergent constituents. In similar experiments, the entire mix- ~
ture is blended together, without intermediate spray drying. Products made ~-are compared to controls in which the entire compositions are spray dried.
Subsequently, the products are stored in open jars for three and seven days ;
at 100C. and 80% humidity, after which time they are observed for caking characteristics. It is found that the control products are very heavily caked and in essence, are brick-like, whereas the "experimental" products flow but contain some medium sized lumps. Utilizing plant production equipment, lower initial moisture content, encapsulating means, favorable carton designs and -improved storage conditions, the proportion of such caking is diminished further.
From this experiment, the various modifications of the processes thoreof which may be carried out in accordance with the teaching of the pre-vious specification and the rosults thereof it is evident that the use in ~ ;
those detergent compositions of hytrated iminodialkanoates improves storage and subsoquont flow charactoristics of the dotorgents. It doos so without harming tho washing abilities or othorwiso affocting the products and those rosulting are suporior in washing powor to other permissible non-phosphate -detergents and sometimes are superior to comparable heavy duty built deter- ~ -gonts basod on pontasodium tripolyphosphato.
Tho invontion has been described with respect to examples and illus-trations of embodiments thereof but is not to be considered as limited to them, since it will be clear to one of skill in the art how to substitute equivalents and modify the operations without doparting from tho spirit of the invention.

.-.

Claims (14)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A particulate heavy duty synthetic organic detergent composition which comprises 5 to 30 parts of anionic detergent and/or 1 to 10 parts of nonionic detergent and, as a builder therefor, 15 to 50 parts of a water-soluble salt of a hydroxy C2-C4 alkyl iminodi C2-C4 carboxylic acid hydrated by 3 to 10 moles of water per mole of iminodicarboxylate.

2. A heavy duty detergent composition according to claim 1 wherein the builder salt is a dialkali metal iminodiacetate polyhydrate.

3. A detergent composition according to claim 2 wherein the iminodi-acetate polyhydrate is disodium 2-hydroxyethyl iminodiacetate hexahydrate.

4. A detergent composition according to claim 3 wherein the particles of synthetic organic detergent are in the form of spray dried beads.

5. A detergent composition according to claim 1 which comprises from 5 to 30 parts of anionic detergent and/or 1 to 10 parts of nonionic detergent, 5 to 30 parts of alkali metal silicate, 4 to 20 parts of alkali metal carbon-ate, 0.3 to 3 parts of organic gum anti-redeposition agent, 1 to 20 parts of moisture, 5 to 40 parts of alkali metal sulfate and 15 to 50 parts of builder salt hydrate.

6. A detergent composition according to claim 4 which comprises from 5 to 30 parts of anionic detergent, 1 to 8 parts of nonionic detergent, 5 to 30 parts of alkali metal silicate, 4 to 20 parts of alkali metal carbonate, 0.3 to 3 parts of organic gum anti-redeposition agent, 1 to 20 parts of moisture, 5 to 40 parts of alkali metal sulfate in the beads and 15 to 50 parts of disodium 2-hydroxyethyl iminodiacetate hexahydrate.

7. A phosphate-free and NTA-free detergent composition according to claim 6 which comprises from 5 to 30 parts of sodium linear alkyl benzene sulfonate, 1 to 8 parts of higher fatty alcohol poly-lower alkoxylate deter-gent, 5 to 15 parts of sodium silicate of an Na2O:- SiO2 ratio in the range of 1:2.0 to 1:2.4, 4 to 20 parts of sodium carbonate, 0.3 to 3 parts of sodium carboxymethyl cellulose, 1 to 15 parts of moisture and 5 to 40 parts of sodium sulfate in the beads and 15 to 30 parts of disodium 2-hydroxyethyl iminodiacetate hexahydrate, with the particles being within the range of 6 to 100 mesh.

8. A method of making a free flowing, particulate heavy duty synthetic organic detergent composition which comprises 5 to 30 parts of anionic deter-gent and/or 1-10 parts of nonionic detergent and, as a builder therefor, 15 to 50 parts of a water-soluble salt of a hydroxy C2-C4 alkyl iminodi C2-C4 carboxylic acid hydrated by 3 to 10 moles of water per mole of iminodicarboxy-late, which comprises making particles of the heavy duty synthetic organic detergent composition components exclusive of the said builder salt and ad-mixing with them particles of said builder salt hydrate.

9. A method according to claim 8 wherein the builder salt is a di-alkali metal iminodiacetate polyhydrate.

10. A method according to claim 9 wherein the builder salt is 2-hydroxy-ethyl iminodiacetate hexahydrate.

11. A method according to claim 10 wherein the organic detergent is spray dried and after spray drying the particles of 2-hydroxyethyl iminodi-acetate hexahydrate are post-added and mixed with such particles.

12. A method according to claim 11 wherein the spray dried particles of the detergent comprise from 5 to 30 parts of anionic detergent and/or 1 to 10 parts of nonionic detergent, 5 to 30 parts of alkali metal silicate, 4 to 20 parts of alkali metal carbonate, 0.3 to 3 parts of organic gum anti-redeposition agent, 1 to 10 parts of moisture and 5 to 40 parts of alkali metal sulfate and/or alkali metal chloride, to which are post-added particles of about the same size of 2-hydroxyethyl iminodiacetate hexahydrate, after which addition the particles are mixed.

13. A method according to claim 12 wherein an aqueous detergent com-position crutcher mix is spray dried to detergent beads of particle sizes in the 6 to 100 mesh range, which beads comprise from 5 to 30 parts sodium linear higher alkyl benzene sulfonate, 1 to 8 parts of higher fatty alcohol poly-lower alkoxylated detergent, 5 to 15 parts of sodium silicate of an Na2O:-SiO2 ratio in the range of 1:2.0 to 1:2.4, 4 to 20 parts of sodium carbonate, 0.3 to 1 part of sodium carboxymethyl cellulose, 1 to 10 parts of moisture and 5 to 40 parts of sodium sulfate and such spray dried beads resulting are admixed with 15 to 30 parts of disodium 2-hydroxyethyl iminodiacetate hexa-hydrate of particle sizes in the 6 to 100 mesh range.

14. A method according to claim 13 in which additional nonionic deter-gent, sodium silicate and sodium carboxymethyl cellulose are post-added to the spray dried product, the silicate as an aqueous solution and thereafter nonionic detergent being sprayed onto the product surfaces in liquid droplet form and the sodium carboxymethyl cellulose being admixed therewith as a finely divided powder, with particles in the range of 100 to 200 mesh, during tumbling of the beads, the proportions of silicate, detergent and sodium carboxymethyl cellulose added being such that the total proportions thereof in the product are 1 to 8 parts of higher alcohol poly-lower alkoxylate, 5 to 30 parts sodium silicate and 0.3 to 3 parts of sodium carboxymethyl cellulose.