US2961409A - Process for preparing detergent compositions - Google Patents

Description

J. B. MARTIN Nov. 22, 1960 PROCESS FOR PREPARING DETERGENT COMPOSITIONS Filed April 2, 1957 ies Hydration of STP II in Aqueous Slurr lmlnpractically no STF-6H O D. IOmln. no STP-GH O E. 25 min. much STP-S H 57in. 2min. much sTP-e H2O 45min. much STP-GH F, 45 mln. much STP-GH O [area/0r Jam .fi'ruae Mari r 2,961,409 Ice Patented Nov. 22, 1960 PROCESS FOR PREPARING DETERGENT COMPOSITIONS John Bruce Martin, Wyoming, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio Filed Apr. 2, 1957, Ser. No. 650,117

7 Claims. (Cl. 252-109) This invention relates to a method for producing heat dried detergent compositions which contain sodium tripolyphosphate. More particularly, this invention relates to a process for producing heat dried detergent compositions which comprises incorporating anhydrous sodium tripolyphosphate in an aqueous detergent mixture and then heat drying the resultant slurry.

This application is a continuation-in-part of my copending application Serial No. 437,179, filed June 16, 1954, and now abandoned.

Heat dried sodium tripolyphosphate-containing detergent compositions are well known. Such compositions are commonly produced in the industry by first preparing a fluid detergent mixture, adding to this fluid mixture sodium tripolyphosphate and then heat drying the resultant slurry either by spray drying or by drying on a heated steel roll.

The sodium tripolyphosphate which is normally used in the production of such detergent compositions is known to exist in two forms-Form I, produced if the phosphate is calcined at high temperature, and Form II if the phosphate during its manufacture is calcined at lower temperature. Both of these forms of tripolyphosphate have been recognized from time to time as giving rise to certain undesirable characteristics in detergent compositions of which they comprise a substantial part. Thus, Form I sodium tripolyphosphate, in its commercially available form, when added to a fluid detergent mixture tends to hydrate very rapidly and form hard small lumps or agglomerates which persist through the entire processing and appear as hard sand-like particles in the final heat dried product. Form II sodium tripolyphosphate, on the other hand, hydrates rather slowly when added to a fluid detergent mixture and, unless the crutcher mix is aged as set forth in Hizers US. Patent 2,622,068, has the objectionable tendency of producing final heat dried compositions which are sticky in nature and which lump and cake badly under even very slight pressure.

In a conventional method for producing heat drie tripolyphosphate-containing detergent compositions a fluid detergent mixture, as hereinafter defined, and commonly referred to in the industry as a crutcher mix, is first prepared. The sodium tripolyphosphate is then added to this aqueous detergent crutcher mix with thorough agitation and the resultant slurry is spray dried. It is in connection with this tripolyphosphate-containing crutcher mix that additional difliculties are experienced in that after the addition of the sodium tripolyphosphate the resultant slurry is rather viscous in nature and may be referred to as having a high consistency. This high consistency usually gives rise to difficulties in mixing, pumping and spraying. If an effort is made to lower the consistency, as by the addition of more water to the slurry, the amount of moisture which must be removed during the spray drying process is increased and this increased evaporative load will be reflected in costly decreased production with a given amount of heat input to the spray drying tower.

Moreover, depending upon the particular mixture of anhydrous tripolyphosphates being used, variable amounts of hydration to thehexahydrate occurs in the crutcher mix and this tends to cause variations in consistency, in the sprayed particle sizes, and in fluctuating conditions generally in the spray drying tower as regards temperature, evaporative load etc., thus causing undesirable nonuniform operation of the process and non-uniformity in the physical characteristics of the spray-dried product.

It is an object of this invention to provide a method for the manufacture of detergent compositions wherein the rate of hydration of Form II sodium tripolyphosphate in aqueous fluid detergent mixtures is markedly reduced.

This slower hydration rate of the Form II tripolyphosphate promotes the formation of larger sodium tripolyphosphate hexahydrate crystals, as described more completely hereinafter, and the resultant slurry consequently has a lower and more uniform consistency.

A further object of this invention is to utilize processing advantages stemming from the lower and more uni-j form consistency of the phosphate-containing crutcher mixes prepared with this more slowly hydrating Form II sodium tripolyphosphate. I

I have found that these objects may be achieved by taking steps to make sure that Form II sodium tripolyphosphate added to the aqueous detergent crutcher mix during manufacture of the detergent compositions contains less than 0.1% water, and preferably less than 0.05% water, other than water of constitution, as contrasted with the much higher contents normally found in supposedly anhydrous tripolyphosphates of commerce.

Wherever herein moisture content values are given for specific samples of tripolyphosphate, the moisture was determined by the loss on ignition method. Although this method of determining moisture would include any water of constitution in the phosphate, i.e. water that is chemically combined, such as in the sodium hydrogen phosphates, it is to be understood that the water of constitution has a negligible effect on the consistency of phosphatecontaining crutcher mixes.

In the accompanying illustrations: Figures 1A through" 1C are photomierographs of the hexahydrate crystal structure derived from slightly hydrous Form II sodium tripolyphosphate after hydration and crystallization had been allowed to proceed for varying lengths of time; and

Figures 1D through 1F are photomicrographs of the.

hexahydrate crystal structure derived from substantially completely anhydrous Form II sodium tripolyphosphate after hydration and crystallization had been allowed to proceed for varying lengths of time.

It is to be understood that the sodium tripolyphosphate referred to herein and in the claims is the normal salt,

oil, babassu oil, soybean oil, castor oil, tallow, whale.

and fish oils, grease and lard, and mixtures thereof) .or of synthetically produced fatty acids (e.g. by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer-Tropsch process), of resin acid (e.g. rosin and those resin acids in tall oil) and/or of naphthenic acids. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by? the neutralization of the free fatty acids which are pre paredin a separate manufacturing process.

(2) Synthetic organic detergents characterized by their high solubility in water, their resistance to precipitation by the constituents of hard water and their surface active and effective detergent properties, including:

(a) Anionic synthetic detergents (excluding true soaps): This class of synthetic detergentsca'n be broadly described as' thewater-soluble salts, particularly the 'alkali'metal salts, of organic sulfuric reaction products having in the molecular structure an alkyl radical containing from-about 8toabo1it 22 carbon atoms and a'radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals. Important examples of the synthetic detergents which form a part of the preferred compositions of the present invention are the sodium or potassiumalkyl sulfates, especially those obtained by sulfating the higher alcohols produced by reducing theglycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in which the alkyl group contains from about 9 to about 15 carbon atoms, especially those of the types described in United States Letters Patent Numbers 2,220,099 and 2,477,383; sodium alkyl glyceryl ether sulfonates, especially those'ethers of the higher alcohols derived from tallow andcoconut oil; sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium or potassium salts of sulfuric acid esters'of the reaction product of one mole of a higher fatty alcohol (e .g. tallow or coconut oil alcohols) and about three moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with four units of ethylene oxide per'molecule and in which the alkyl radicals contain about 9carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; sodium or potassium metal salts of fatty acid amide of a methyl taurine in which the fatty acids, for example, are derived from coconut oil; and others known in the art, a number being specifically set forth in United States Letters Patent Numbers 2,486,921, 2,486,922 and 2,396,278.

(b) Nonionic synthetic detergents: This class of,syn-

thetic detergents may be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in natpre. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a watersoluble compound having the desired degree of balance between hydrophilic and hydrophobic elements,

For example, a well known class of nonionic synthetic detergents is made available on the market under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility has a molecular weight o f-from about 1500.to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the products is retained up to the point where polyoxyethylene content is about 50% of the total weight of the condensation product.

"Other suitable nonionic synthetic detergents include: (i) The polyethylene oxide condensates of alkyl phenols, e.g. the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12.

carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 10 to 25 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octane, or nonane, for example.

(ii) Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine-products which may be varied in composition depending upon the balance between hydrophobic and hydrophilic elements which is desired. For example, compounds containing from about 40% to about polyoxyethylene by weight and having a molecular weight of from about 5000 to about 11,000, resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of2500 to 3000, are satisfactory.

(iii) The condensation product of aliphatic alcohols having from 8 to 18 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g. a coconut alcohol ethylene oxide condensate having from 10 to 30 moles of ethylene oxide per mole of coconut alchol, the coconut alcohol fraction having from 10 to 14 carbon. atoms.

It is to be understood. that the term detergent mixture and/or detergent mix asused herein includes, in addition to one or more of the above detergents, alkaline build ers or detergent improving agents such as the sodium and other alkaline carbonates, silicates, phosphates and borates and/or such compounds as the perborates, persulfates and percarbonates; also organic builders and perfumes, coloring matter, preservatives and other substances commonly found in detergent compositions.

Commercially availableform I and Form II sodium tripolyphosphates, or mixtures thereof, as a rule average above 0.2% in moisture content as received, and furthermore tend to be variable in moisture from outside to inside the mass. It is to be understood of course that this moisture content is not inherent in the sodium tripoly phosphate as manufactured and that as obtained from the calcining kiln thetripolyhosphate is completely anhydrous. The moisture content is picked up, usually from. the atmosphere, during subsequent handling of the anhydrous product. It is to be appreciated that, depending upon the manner by which the moisture in the tripolyphosphate product is picked up, the sodium tripolyphosphates available on the market vary widely as to the amount of moisture which they contain and moisture contents as high as, 1% or greater are not unusual.

Itflis the presence of this water in excess of 0.1% which imparts to the sodium tripolyphosphate hydration properties which give rise tothe aforementioned undesirable characteristics in detergent compositions preparedwith them. I have made the totally unexpected discovery that if this water is removed, or if its pickup by the triployphosphate is prevented, the hydration characteristics of the tripolyphosphate are radically changed.

The difference in hydration characteristics between a slightly, hydrous sample ofForm II sodium tripolyphosphate (about 0.15% water) and a substantially completely anhydrous Form II sample (0.02% water) is evident from a'comparison of Figures 1A to 1C, photomicrographs, at various time intervals, of the slightly hydrous F ormII sodium tripolyphosphate hydrating and crystallizing as the ,hexahydrate, and Figures 1D to 1F, photomierographs, at variou s] time intervals, of the substantially completely anhydrous Form II sodium tripolyphosphate hydrating and cry'stallizing as the hexahydrate.

The technique used in obtaining these photomicrographs .Was as follows:

A small sample of the dry..sodium tripolyphosphate powder was: placed'betweena microscope slide and cover glass. Theflayerfwas thinfenough so that some of the individual particles could'be seen in the dry form, but not 'softhin that all of the sample dissolved when a drop oflwafter was allowed to flow under the cover glass by capillary action. "Agitation ofthe slurry was carefully avoided. Microscopic examination was made at a magnification of 8 5 diameters with crossed nicols.

As can be seen from Figures 1A to 1?, with the,

slightly hydrous Form II sodium tripolyphosphate, prachexahydrate crystals present had further increased. In contrast, with the substantially completely anhydrous -Form II sodium tripolyphosphate, no hexahydrate crystals were in evidence less than 10 minutes after the addition of the water (Fig. 1D). however, much hexahydrate was in evidence but was in After 25 and 45 minutes,

"the form of a few large spherulites rather than in the form of the very small hexahydrate crystals obtained with slightly hydrous Form II sodium tripolyphosphate.

The consistency of the sodium tripolyphosphate-containing crutcher mix slurry is believed to be dependent upon the size of the tripolyphosphate hexahydrate crystals present in the slurry and the larger the size of these crystals the lower the consistency of the slurry. Thus, the use of the substantially anhydrous tripolyphosphate which results in the formation of larger hexahydrate crystals as hereinbefore described, gives a lower tripolyphosphate-containing crutcher mix consistency and the mixing, pumping, and spraying advantages which would be inherent in such a more fluid slurry.

An additional advantage is realized from the use of substantially completely anhydrous Form II sodium tripolyphosphate in accordance with my invention. The sodium tripolyphosphates have a tendency to undergo a hydrolysis or an intramolecular absorption of water from the hexahydrate with resultant formation of somewhat less alkaline salts of pyroand/ or ortho-phosphoric acid, commonly referred to as reversion. This reversion in general occurs only when the tripolyphosphates are in water solution or slurries at high temperatures and/or during dehydration of their hydrates, the latter occurring quite commonly during the heat drying process. Since,

-with the use of substantially completely anhydrous Form II sodium tripolyphosphate less hydration of the tripolyphosphate takes place in the crutcher mix, the potential for reversion of the tripolyphosphate (during drying) to the less desirable phosphates is reduced.

As has been pointed out in my co-pending application,

{Serial No. 650,190, filed currently herewith, the amount of Form I tripolyphosphate present in the mixture of Form I and Form II of sodium tripolyphosphates added to the crutcher mix has a profound effect upon characteristics of the crutcher mix. Thus, as little as 5% Form I is detectable in the crutcher mix by the behavior characteristics of the tripolyphosphate, while at Form I, the ascendency of the Form I behavior characteristics is quite evident, and at about 25% or more Form I the behavior characteristics associated with Form I tripolyphosphate dominate.

Consequently, in order to realize fully the advantages particular to the use of substantially completely anhydrous Form II tripolyphosphate in accordance with the present invention, and not identified with the use of substantially completely anhydrous Form I sodium tripolyphosphate, I desire to include within the scope of my invention only those mixtures of sodium tripolyphosphates containing from about 90 to 100% Form II tripolyphosphate, and, more preferably, sodium tripolyphosphate mixtures containing greater than about 95% Form II tripolyphosphate.

It is to be noted that the percentage of Form I and Form II tripolyphosphate wherever they appear herein or in the claims are expressed on the basis of the sodium tripolyphosphates present in the mixture of phosphates employed, commercial sodium tripolyphosphates containing small percentages of other phosphates, such as orthoor pyro-phosphate, which are incident to the sodium tripolyphosphate manufacturing process.

' In the following example all consistency measurements '6 given are expressed in arbitrary units as determined with a commercially available instrument called the Brabender Plastograph which records continuously the torsion moment required to rotate a pair of agitators in the viscous mixture being examined.

It is to be appreciated in connection with the example, and with the described detergent manufacturing process in general, that when the sodium tripolyphosphate is added rapidly to an aqueous detergent crutcher mix there is a rapid and large increase in the consistency of the mix because of the then poor distribution of the phosphate in the mix. The high consistency incident to the tripolyphosphate addition is only temporary however and the consistency drops oif as the tripolyphosphate is evenly distributed throughout the crutcher mix. Furthermore, it is common practice when making a tripolyphosphate-containing detergent to add sodium silicate to the crutcher mix for several beneficial purposes including inhibition of aluminum corrosion by the finished detergent product. This silicate is normally added, because of pH considerations and for convenience, shortly after the tripolyphosphate has been added to the detergent crutcher mix and the addition therefore frequently occurs when the consistency of the crutcher mix slurry is at a maximum level as a result of the tripolyphosphate addition. For these reasons I have chosen to use the silicate addition as a time base and in the following example the consistency for any given crutcher mix slurry is expressed for minutes after the addition of the silicate.

It is to be understood, however, that the above described mode of expression is merely for convenience in presenting the examples and that some other time basis could just as well have been chosen, the addition of silicate with the process of my invention being optional.

The following specific example is to be considered as illustrative only and changes and modifications therein as would normally occur to those skilled in the art are contemplated.

Example 1.Two samples of Form II sodium tripolyphosphate, Sample A containing 0.15% water, and Sample B containing 0.00% moisture (prepared by igniting a portion of Sample A at 400 C. for two hours), were used to prepare crutcher mix slurries with an aqueous detergent mixture containing 9.1% sodium alkyl benzene sulfonate detergent (the alkyl radical averaging about 12 carbon atoms and being derived from polypropylene), 15.1% sodium alkyl sulfate detergent (the alkyl groups being derived from higher alcohols produced by the reduction of tallow and being about 65% C 33% C and 2% C 59.1% water and 15.5% sodium sulfate, the remainder of the mixture comprising unsulfated material. The tripolyphosphate samples were added in the amount of 371 parts, by weight, to 535 parts, by weight, of the detergent mix. V

93 parts of sodium silicate was added to each of the above mixtures and the consistency of the resulting slurries was determined with the Brabender Plastograph with the following results. The percent hydration of the UL polyphosphate in the sample is also given.

7 Percent Hydration Consistency of Slurry Minutes After Silieate Addition HA7) BU AH B STP =sodium tripolyphosphate.

It may be seen from the above data that the anhydrous Form II sodium tripolyphosphate hydrates at a much slower rate than the slightly hydrous Form 11 sodium'tripolyphosphate; Also, the ability of the anhydrous Form IIEsodium tripolyphosphate to form and maintain crutcher mix slurries of thin consistency is evident.

In the preceding example detergents of each of the various types enumerated hereinbefore can be substituted for the detergents specifically mentioned in the example with comparable results, it being understood that the operation can be readily adjusted to accommodate any minor changes in crutcher mix consistency resulting from the use of different detergents. Also, it is to be appreciated that tripolyphosphates of potassium and other alkali metals may be used in conjunction with the sodium tripolyphosphates specifically mentioned, and that the sodium tripolyphosphate-containing detergent compositions produced in accordance with my process may be in flake, thread, powder to spray dried granular or powdery form.

Following are some additional examples of the practice of my invention in which parts shown are by weight.

Example 2.50 parts of completely anhydrous 100% Form II sodium tripolyphosphate is added to 50 parts of an aqueous detergent mix containing about 40% sodium alkyl sulfate detergent (the alkyl groups being derived from the higher alcohols obtained by the reduction of coconut oil), 50% water and 10% sodium sulfate. The resultant mixture, after spray drying, is an excellent a1lpurpose detergent.

If desired, the alkyl sulfate detergents in the foregoing example are replaceable by like amounts of other detergent agents with comparable results. Thus, sodium alkyl glyceryl ether sulfonate (the alkyl groups of which are derived from a middle cut coconut fatty alcohol mixture having the composition: 10 carbon atoms2%; 12 carbon atoms-66%; 14 carbon atoms-23%; and 16 carbon atoms-9%), the sodium salt of sulfated monoglyceride of hydrogenated coconut oil fatty acids, the sodium salt of the sulfuric acid esters of the reaction product of one mole of the higher fatty alcohols derived from the reduction of coconut oil and three moles of ethylene oxide, the reaction product of coconut oil fatty acids esterified with isethionic acid and neutralized with sodium hydroxide and the sodium salt of oleic acid amide of N-methyl taurine, all find ready application in the foregoing formulation and provide excellent general-purpose detergents.

Example 3.40 parts of completely anhydrous Form II sodium tripolyphosphate is added to 60 parts of an aqueous detergent mix containing as a detergent about 25% Pluronic F 68 (the condensation product of ethylene oxide with a polyoxypropylene base, the said polyoxypropylene base having a molecular weight of about 1500 to about 1800, and the said condensation product having a molecular weight of about 8000), 15% sodium sulfate, sodium silicate and 55% water. The resultant mixture, after spray drying is an excellent detergent agent, particularly in uses where excessive sudsing is not desirable.

Other nonionic synthetic detergents, such as, Igepal CO-720 (a nonyl phenol ethylene oxide condensate having on the average 15 moles of ethylene oxide per mole of nonyl phenoyl), the alkyl ethylene oxide condensate wherein the alkyl radical is derived from alcohols produced by the reduction of coconut oil fatty acids having from 10 to 14 carbon atoms, the said condensate having an average molecular weight of about 800, and Tetronic 707 (a commercially available nonionic condensation product identified by a molecular weight of about 11,000 and obtained from the condensation of ethylene oxide with a hydrophobic base derived from the condensation of propylene oxide with ethylene diamine, said base having a molecular weight of the order of 2500 to 3000), are readily substituted for the Pluronic P68 in the foregoing example in like amounts with comparable results.

Example 4.-33 parts of completely anhydrous Form II sodium tripolyphosphate is added to 67 parts of an aqueous detergent mixture containing about 15% sodium alkyl benzene sulfonate detergent (the alkyl radical averaging about 12 carbon atoms and being derived from polypropylene), about 37% of a sodium soap. obtained by the saponification of tallow, about 5% sodium sulfate and about 43% water. The resultant mixture is spray dried and gives an excellent detergent agent having a relatively low sudsing level.

The substitution, in like amounts, of a sodium soap obtained by the saponificatiou of coconut oil for the sodium soap obtained by the saponification of tallow in the above example results in a detergent composition having comparable performance characteristics. Also, with any of the foregoing compositions drying is readily accomplished on a heated steel roll with comparable results.

Example 5.-25 parts of completely anhydrous Form 11 sodium tripolyphosphate is added to parts of an aqueous solution of 50% soap (normal sodium kettle soap obtained from the saponification of a mixture of tallow and 20% coconut oil), 45% water and 5% sodium silicate. The mixture, after spray drying, is an excellent detergent having balanced sudsing and cleansing properties.

In the above example, the substitution, in like amounts, of the normal sodium kettle soap obtained from the saponification of a mixture of 60% palm oil, 20% babassu oil and 20% hydrogenated marine oils, for the normal sodium kettle soap specified gives comparable results. The substitution of normal potassium kettle soap for the sodium kettle soap in any of the foregoing compositions of this example is also readily accomplished and results in detergent compositions having comparable performance characteristics.

The utility of the invention is particularly attractive in the manufacture of detergent compositions wherein the ratio of sodium tripolyphosphate to organic detergent ranges from about 1:1 to 5:1 and the weight of water used in making the fluid mixture to be spray dried does not exceed the weight of tripolyphosphate used.

It is to be pointed out that in the manufacture of detergents in particulate form which contain substantial amounts of sodium tripolyphosphates, little of the tripolyphosphate is in solution during the processing of the crutcher mix, most of it being suspended as a slurry. Consequently, in order to insure the desired rapid solution of the final detergent product in water, the particle size of the sodium tripolyphosphate should be regulated and should, in general, be no larger than that desired in the final product.

Having thus described my invention, I claim:

1. In the process of producing a heat dried detergent composition containing substantial amounts of sodium tripol 'phosphate, the step of incorporating a substantially completely anhydrous sodium tripolyphosphate containing from about to of Form 11 sod.um tripolyphosphate and containing not more than 0.1% water, other than water of constitution, in a fluid detergent mixture, containing essentially (a) an organic detergent selected from the group consisting of sodium and potassium salts of higher molecular weight carboxylic acids, water soluble salts of organic sulfuric reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals, and water soluble nonionic synthetic detergent condensation products of alkylene oxide groups which are hydrophilic in nature with an organic hydrophobic compound selected from the group consisting of aliphatic compounds and alkyl, aromatic compounds, the ratio of sodium tripolyphosphate to organic detergent ranging from about 1:1 to 5:1, and (b) more than sufficient water to hydrate the sodium tripolyphosphate added and sufficient to provide and maintain a fluid detergent mixture, whereby the rate of hydration of the Form 11 sodium tripolyphosphate to the hexahydrate is decreased and the fluid detergent mixture remains fluid.

2. The process of claim 1 wherein the sodium tripolyphosphate contains not more than 6.05% water, other than water of constitution.

3. The process of claim l wherein the sodium tripolyphosphate added contains greater than about 95% Form II sodium tripolyphosphate.

4. The process of claim 1 wherein the sodium tripolyphosphate is wholly anhydrous Form I1 tripolyphosphate.

5. The process of claim 1 wherein the weight of the water used in making the fluid mixture does not exceed the weight of said tripolyphosphate.

6. In the process of producing a heat dried detergent composition containing substantial amounts of sodium tripolyphosphate, the steps which comprise, (1) drying a commercially available sodium tripolyphosphate containing from about 90% to 100% Form II sodium tripolyphosphate to a uniformly substantially completely anhydrous condition wherein not more than 0.1% water, other than water of constitution, is present, and (2) incorporating the thus dried tripolyphosphate in a fluid detergent mixture containing essentially (a) an organic detergent selected from the group consisting of sodium and potassium salts of higher molecular weight carboxylIc acids, water soluble salts of organic sulfuric reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals, and water soluble nonionic synthetic detergent condensation products of alkylene oxide groups which are hydrophilic in nature with an organic hydrophobic compound selected from the group consisting of aliphatic compounds and alkyl aromatic compounds, the ratio of sodium tripolyphosphate to organic detergent ranging from about 1:1 to :1, and (b) more than sufficient water to hydrate the tripolyphosphate added and sufficient to provide and maintain a fiuid detergent mixture, whereby the rate of hydration of the Form II sodium tripolyphosphate to the hexahydrate is decreased and the fluid detergent mixture remains fluid.

7. In the process of producing a heat-dried detergent composition containing substantial amounts of sodium tripolyphosphate, the steps which comprise, (1) maintaining sodium tripolyphosphate containing from about to Form 11 sodium tripolyphosphate substantially in its initial completely anhydrous state wherein not more than 0.1% water, other than the water of constitution, is present, and (2) incorporating the said tripolyphosphate in a fluid detergent mixture containing essentially (a) an organic detergent selected from the group consisting of sodium and potassium salts of higher molecular weight carboxyl.c acids, water soluble salts of organic sulfuric reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals, and water soluble nonionic synthetic detergent condensation products of alkylene oxide groups which are hydrophilic in nature with an organic hydrophobic compound selected from the group consisting of aliphatic compounds and alkyl aromatic compounds, the ratio of sodium tripolyphosphate to organic detergent ranging from about 1:1 to 5:1 and (b) more than sufficient water to hydrate the tripolyphosphate added and suflicient to provide and maintain a fluid detergent mixture, whereby the rate of hydration of the Form 11 sodium tripolyphosphate to the hexahydrate is decreased and the fluid detergent mixture remains fluid.

References Cited in the file of this patent UNITED STATES PATENTS 2,396,278 Lind Mar. 12, 1946 2,486,922 Strain Nov. 1, 1949 2,622,068 Hizer Dec. 16, 1952 2,773,833 Lewis et a1. Dec. 11, 1956 FOREIGN PATENTS 680,346 Great Britain Oct. 4, 1952

Claims (1)

1. IN THE PROCESS OF PRODUCING A HEAT DRIED DETERGENT COMPOSITION CONTAINING SUBSTANTIAL AMOUNTS OF SODIUM TRIPOLYPHOSPHATE, THE STEP OF INCORPORATING A SUBSTANTIALLY COMPLETELY ANHYDROUS SODIUM TRIPOLYPHOSPHATE CONTAINING FROM ABOUT 90% TO 100% OF FORM 11 SODIUM TRIPOLYPHOSPHATE AND CONTAINING NOT MORE THAN 0.1% WATER, OTHER THAN WATER OF CONSTITUTION, IN A FLUID DETERGENT MIXTURE, CONTAINING ESSENTIALLY (A) AN ORGANIC DETERGENT SELECTED FORM THE GROUP CONSISTING OF SODIUM AND POTASSIUM SALTS OF HIGHER MOLECULAR WEIGHT CARBOXYLIC ACIDS, WATER SOLUBLE SALTS OF ORGANIC SULFURIC REACTION PRODUCTS HAVING IN THEIR MOLECULAR STRUCTURE AN ALKYL RADICAL CONTAINING FROM ABOUT 8 TO ABOUT 22 CARBON ATOMS AND A RADICAL SELECTED FROM THE GROUP CONSISTING OF SULFONIC ACID AND SULFURIC ACID ESTER RADICALS, AND WATER SOLUBLE NONIONIC SYNTHETIC DETERGENT CONDENSATION PRODUCTS OF ALKYLENE OXIDE GROUPS WHICH ARE HYDROPHILIC IN NATURE WITH AN ORGANIC HYDROPHOBIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC COMPOUNDS AND ALKYL AROMATIC COMPOUNDS, THE RATIO OF SODIUM TRIPOLYPHOSPHATE TO ORGANIC DETERGENT RANGING FROM ABOUT 1:1 TO 5:1, AND (B) MORE THAN SUFFICIENT WATER TO HYDRATE THE SODIUM TRIPOLYPHOSPHATE ADDED AND SUFFICIENT TO PROVIDE AND MAINTAIN A FLUID DETERGENT MIXTURE, WHEREBY THE RATE OF HYDRATION OF THE FORM 11 SODIUM TRIPOLYPHOSPHATE TO THE HEXAHYDRATE IS DECREASED AND THE FLUID DETERGENT MIXTURE REMAINS FLUID.

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