GB1589314A - Saponification of organic acid esters and detergent compositions - Google Patents

Description

(54) SAPONIFICATION OF ORGANIC ACID ESTERS, AND DETERGENT COMPOSITIONS (71) We, THE PROCTER & GAMBLE COMPANY, a corporation organised under the laws of the State of Ohio, United States of America, of 301 East Sixth Street, Cincinnati, Ohio 45202, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention encompasses methods for saponifying organic acid esters, including fatty acid glyceride esters. More specifically, organic acid esters are saponified with an alkali metal hydroxide in a liquid reaction medium comprising a substantially water-free alkyl nitrile to provide unsolvated alkali metal salts of the organic acids. When fatty acid esters are used in the process, dry alkali metal soaps are secured.

The preparation of alkali metal salts of organic acids by saponifying the corresponding organic acid esters, as in traditional soap making processes, is typically carried out using an alkali metal hydroxide base, the organic acid ester, and water as the reaction medium. Heretofore, such reactions have been energy intensive for at least two reasons. First heat energy is required to initiate and sustain the saponification of the organic acid ester by the acqueous solution of the alkali metal hydroxide. Second, the organic acid salts are strongly solvated by the water from the acqueous reaction medium. Accordingly, some of the water must be removed to recover the oganic acid salts, and heat energy is needed for this solvent removal step.

This heat energy requirement is a characteristic of many processes for preparing soap products in granular, flake or bar form. It is characteristic also of processes for preparing synthetic detergents in solid, e.g., granular form, wherein an aqueous crutcher mix is dried by an energy intensive process such as spray drying, From the foregoing, it will be readily appreciated that any means whereby the high water content of wet process soaps or acqueous crutcher mixes can be adjusted to some lower level without heat input would be advantageous. However, simply absorbing the water onto inert filler ingredients is not a desirable means for securing a lower moisture level, inasmuch as filler materials add nothing to the cleaning performance of the final compositions.

Soap, in a form having a low moisture content, or substantially dry, would be an excellent material for adjusting the moisture content of wet soaps or detergent crutcher mixes. However, low moisture content soaps prepared without an energy-intensive drying step have not been available heretofore.

By the present invention, it has been discovered that substantially water-free alkyl nitriles provide a reaction medium wherein organic acid esters can be saponified with alkali metal hydroxides to provide the alkali metal salts of organic acids which precipitate from the reaction medium in the unsolved form. Accordingly, solvent removal in the present process is not as energy intensive as in the aqueous process. Moreover, the present process is exothermic and, once initiated, proceeds essentially to completion without external heating. Soap making processes carried out in the manner of the present invention using fatty glycerides as the organic acid ester provide substantially dry, unsolvated soap powder in an extremely short period of time in exceptionally high yields.

The art of preparing the alkali metal salts of organic acids, especially as it is embodied in soap making processes, is old and is the subject of a large body of literature. Anhydrous soap making processes have been disclosed heretofor, as have soap making processes which employ organic solvents as the reaction medium. The alkyl nitriles used as the reaction medium in the present process are well-known materials.

Despite the voluminous literature in this area and the long history of soap making and syntheses of fatty acid salts, the present process does not appear to have been contemplated heretofore.

Acetonitrile (methyl cyanide; cyanomethane; ethanenitrile) is a highly preferred alkyl nitrile solvent for use in the present process. As pointed out in THE MERCK INDEX, Seventh Ed., page 8, this material has been used to extract fatty acids from fish liver oils and other animal vegetable oils. This material is also known as a medium for producing reaction involving ionization, as a solvent in non-aqueous titrations, and as a non-aqueous solvent for inorganic salts.

The use of acetonitrile as an extraction solvent for separating/removing various materials from compositions containing fatty acids, sterols, and the like, is disclosed in the following references: U.S. Patents 2,681,922, Balthis, 6/22/54; 2,528,025, WlWte, 10/31/50; Chemical Abstracts 38 6180; 84 80436u; 48 6698; 5713224; 47 3660; 60 2330; 49 15266;54 5126;50 14322;and46 6468.

The use of propionitrile in various liquid phase extraction processes involving glycerides, fatty acids, and the like, is disclosed in U.S.

Patent 2,316,512, Freeman,4/13/43;2,200, 391, Freeman, 5/14/40; 2,313,636, Freeman, 3/9/43; 2,390,528. Freeman 12/11/45; and Canadian 488,250, Freeman, 11/18/52.

Processes for manufacturing modified oil products from fatty oils, for manufacturing soap compositions, and for preparing metallic salts of higher fatty acids, which are carried out under anhydrous conditions or with the use of organic solvents of various types are disclosed in the following references: U.S. Patents 1,957,437, Auer, 5/8/34; 3,376,327, Freeland 4/2/68; 2,271,406, Thurman, 1/27/42; 2,383, 630, Trent, 8/28/45. 3,476,786, Lally and Cunder, 11/4/69, Chemical Abstracts 53 20838 26 5875;52 7743;and 5320850.

Various miscellaneous references relating to the use of cyano compounds or amines of various types in the preparation of carboxylic acids and general references to the use of acetonitrile as a solvent are as follows: U.S Patents 2,042,729, Ralston and Poole, 6/2/36; 3,828,086, Kenney and Donahue, 8/6/74; 3,519,657, Olah, 7/7/70; 2,211,941, Sullivan 8/20/40; 1,833,900, Hoyt, 12/1/31; 2,402,566, Milas, 6/25/46; 2,640,823, Gloyer and Vogel, 6/2/53; 2,895,974, Case, 7/21/59; and Chemical Abstracts 53 9642.

German Patentschrifts 1,254,139, May 30, 1968, discloses a process for preparing saturated fatty acids by reacting an a-olefin with a stoichiometric excess of acetonitrile, or acetate reagent, in the presence of an organic peroxide.

It is clear that the use of the alkyl nitriles as an extraction/separation medium in the manner suggested by these references does not contemplate their use as a reaction solvent in the manner of the present invention. Moreover the use of organic solvents, anhydrous conditions, or cyano compounds to prepare scaps, and the like, does not contemplate the present invention.

Attention is specifically directed to U.S.

Patent 3,133,942, Hahl, patented May 19, 1964, and U.S. Patent 2,753,364, Boner and Breed, patented July 3,1956. The '942 patent relates to the production of metal salts of organic acids and, as disclosed therein, is carried out by using an organic acid and certain metals in the form of metal powders.

Inert organic solvents, including acetonitrile, propionitrile and benzonitrile, are disclosed for use in the process. The process differs from that of the present invention in that it uses neither alkali metal hydroxides nor organic acid esters as the starting materials. Moreover, many of the solvents disclosed as being useful in the '942 patent are not contemplated for use herein.

The Boner, et al., patent, above, relates to a method for manufacturing lithium soaps (lubricating greases) using lithium carbonate and free fatty acids as the starting materials.

Acetonitrile, benzonitrile and "benzyl cyanide" are taught to be useful sovents in the process, along with many other organic solvents. It will be appreciated that this reference does not teach the use of alkali metal hydroxides, nor organic esters, especially glyceride esters, such as those used in the present invention; is almost unlimited as to the type of organic nitrogencontaining materials suggested for use as the solvent medium; and does not teach or suggest the present process which is limited to the alkyl nitriles which have now been discovered to be particularly advantageous when employed in the manner disclosed herein Attention is also directed to the review article Khim. Prom. (Moscow) 1968 44 (10) 7226 (Russ.) which, in abstract form (C.A.

70 28299Y), is said to relate to the use of MeCN as a solvent, its reactions with aldehydes, ketones, alcohols, diens and organic acids, substitution reactions and with inorganic compounds, and which cites 90 references.

Attention is also directed to the review article by E.J. Fischer,Allgem. Oel-u.

Fett-Ztg. 33,78-81(1936) which, in abstract form (C.A. 30 3539), is said to relate to methods for preparing acetonitrile and its use, principally as a solvent.

The co-pending application 44777/77 (Specification serial No. 1589315), corresponding to German offenlengungshift 2745342 discloses and claims a combination of alkyl nitriles and alkali metal hydroxides as super bases which are useful in various chemical processes.

The foregoing references do not appear to contemplate the preparation of soaps by the present process, which may conveniently be referred to as the Peterson process, nor do they suggest the use of Peterson process soaps as drying agents in the manner of this invention.

The present invention encompasses a process for saponifying organic acid esters to their alkali metal salts. The process comprises saponifying the organic ester corresponding to the organic acid salt desired using an alkali metal hydroxide in the liquid reaction medium comprising a substantially water-free liquid alkyl nitrile compound.

The reaction herein can be carried out using glyceride esters, including the mixed monodi- and tri-glyceride esters derived from animal fats and oils and/or vegetable fats and oils. Such materials typically comprise esters of C1 0-C20 fatty acids and are well known for use in soap making processes. Accordingly', the process herein can be used to prepare watersoluble soaps, which are, typically, the alkali metal salts of C1 0-C2 o organic acids.

The present process can also be carried out using lithium hydroxide and esters of C1 0C24 fatty acids thereby securing lithium "soaps" which are especially useful and known in the art as lubricating greases.

The process herein is simply and economically carried out by admixing the alkyl nitrile reaction medium, the ester, and the solid alkali metal hydroxide (typically, pulverised) in a suitable container, initiating the reaction (typically, by gentle heating) and allowing the reaction to proceed. The reaction is exothermic and, once initiated, substantially self-sustaining. Heating can optionally be used to increase yields to the range of 95%-100%.

Soaps prepared in the foregoing manner simply precipitate from the reaction medium as an unsolvated, substantially white powder.

Advantageously, much of the colored matter which is commonly present in commercial grades of animal fats and oils used as the ester starting material is retained in solution in the alkyl nitrile. Accordingly, an excellent soap product, substantially freed from color bodies, can be secured by the present process. Typical yields of soap are in the range of 90% in a matter of a few minutes.

The present invention also encompasses a process for adjusting the water content of wet soaps or wet crutcher mixes to a lower total water content by the addition of soap which has a low water content. The low water content soap used as the "drying agent" in this process is prepared in an energy-sparing manner, by the above described process, and has not been available, heretofore.

The present invention encompasses a process for preparing the alkali metal salts or organic acids which comprises saponifying the corresponding organic acid ester with an alkali metal hydroxide in a liquid reaction medium comprising a substantially water-free alkyl nitrile. The organic acid esters employed herein can be simple alkyl or aryl esters, or can be glyceride esters such as the triglycerides which typically constitute the major proportion of the materials present in fats and oil derived from animal or vegetable sources. The reaction herein can be used, for example, to prepare lubricating greases by saponifying esters of C1 o-Cz4 organic acids with lithium hydroxide. The present process can also be employed to prepare water-soluble detersive sufactants, i.e., soap, by soaponifying esters of organic acids having chain lengths in the range of about CI O -C20. The reaction does not appear to depend on the nature of the acid ester used; hence, alkali metal salts or organic acids having chain lengths shorter or longer than mentioned above, as well as branched chain and aryl organic acids, can also be prepared in the manner of this invention.

The present invention also encompasses an energy-saving process for adjusting the water content of wet soaps or wet crutcher mixed to a lower total water content by adding to said wet materials a quantity of a drying agent which comprises a soap having a low water content which is prepared by the energysparing Peterson process described herein.

By "alkali metal salts of organic acids" herein is meant compounds of the formula RCOOM, wherein the RCOO-group is an organic acid substituent, unlimited in the type of R group, and wherein M is an alkali metal.

The term "soaps" herein means a subgroup of the alkali metal salts of organic acids above wherein RC00-has a total carbon content in the range C1 o-C20 o.

By "organic acid ester" herein meant a compound of the formula RCOOR', whererin RCOO- is as above, and wherein group R' is an organic substituent group derived from an alcohol or polyol, unlimited in type.

By "alkali metal hydroxide" herein is meant lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. Sodium hydroxide and potassium hydroxide are especially useful for making water-soluble soaps for detergent use. Lithium hydroxide is especially use for for preparing lubricating greases.

By "alkyl nitrile" herein is meant a compound of the formula R"CN, wherein R" is a linear, branched chain or cyclic aliphatic substituent. Typical examples of such materials are acetonitrile and propionitrile, which are preferred for use herein. Aromatic nitriles, e.g., benzonitrile, have been found not to be useful as a reaction medium and are not encompassed by the present invention.

Acetonitrile is the most highly preferred alkyl nitrile for use herein.

By "substantially water-free" herein is meant that the water present in the reaction medium, constitutes no more, than 10% by weight of the reaction medium. For example the alkali metal hydroxides, especially LiOH, which is commercially available as the monohydrate, are somewhat hygroscopic and carry some moisture into the system.

By "glycerides" herein is meant organic acid esters of glycerol. The term glycerides encompasses mono-, di- and triglycerides, since glycerol is a trihydric alcohol which can be esterified on any, or all, of the three hydroxly groups. Triglycerides constitute the major components of naturally-occurring fats and oils which are typically used as starting materials in soap making processes.

By "animal or vegetable fats and oils" herein is meant the organic acid glyceride materials which can be secured from a wide variety of sources. Specific, non-limiting examples of such materials include lard, tallow, coconut oil, palm oil, various byproducts from animal rendering operations, oils from oleaginous seeds such as the soybean, sunflower deeds, and the like, cottonseed oil, etc. Typical listings of such materials are widely available, and all such glyceride mixtures are useful in the present process.

By "wet soaps" herein is meant tacky, viscous, water-soluble soap materials, generally characterized by a water content greater than about 14%, by weight, and wet non-soap detersive surfactants.

By "wet crutcher mix" herein is meant an aqueous slurry or solution of detersive ingredients which is characterized by a water content greater than about 14%, by weight, and which will ultimately be dried to a solid, homogeneous detergent (or soap) composition.

By "soap having a low water content" herein is meant a water-soluble, solid soap materials having a water content in the range of from about 0% to about 14%, by weight, and made by the process of the present invention. Such soaps are used as the drying agent in the practice of one aspect of the present invention.

By "wet non-soap detersive surfactant" herein is meant water-soluble, organic surface active agents other than carboxylate soaps having a water content of greater than about 14%, by weight. Such materials specifically include anionic, nonionic, zwitterionic, amphoteric and cationic detersive surfactants well known in the detergency arts. Typical examples of such materials are fully disclosed in U.S. Patents 3,723,322; 3,597,416; and 3,213,030, to F.L. Diehl. The sulfated and/or sulfonated detersive surfactants, such as the alkyl benzene sulfates and sulfonates, are preferred non-soap detersive surfactants used herein in aqueous crutcher mixed to prepare spray dried detergent granules.

By "auxiliary detersive agents" herein is meant well-known materials (other than detersive surfactants) such as water softeners, bleaches, soil suspending agents, anti-redeposition agents, and the like, commoly used in fully formulated, commercial detergent compositions. One type of preferred auxiliary detersive agent includes the detergency builder materials well known in the art.

Typical examples of detergency builders are disclosed in many U.S. Patents, including those of Diehl, above.

By the term "comprising" herein is meant that various other, compatible ingredients can be present in the reaction medium as long as the critical reactants and alkyl nitrile are present. The term "comprising" thus encompasses and includes the more restrictive terms "consisting of' and "consisting essentially of" which can be used to characterize the essential materials (ester, alkali metal hydroxide and alkyl nitrile) used herein.

All percentages herein are by weight, unless otherwise specified.

The process herein is in general carried out by simply admixing the carboxylic acid ester to be saponified with the alkyl nitrile and the alkali metal hydroxide in any suitable reaction vessel. The reaction can be initiated by gently heating the mixture, if desired. However, the saponification reaction of this invention will generally initiate spontaneously on stirring of the reactants for a few minutes. When using carboxylic acid esters which are especially easily saponified (e.g., nitrophenyl esters) the reaction is self-initiating almost immediately and proceeds to substantially 100% completion in the matter of a few minutes, or less.

It is to be understood that the alkali metal hydroxide employed herein is not particularly soluble in the alkyl nitrile reaction medium.

Apparantly, some alkali metal hydroxide does dissolve in the alkyl nitrile and saponifies and equivalent amount of the organic acid ester, whereupon additional alkali metal hydroxide dissolves, etc. For this reason, it is preferred to use alkali metal hydroxides which have been ground to an appropriate particle size to aid in dissolution in the alkyl nitrile. This is not critical to the invention herein, but only makes the reaction more convenient. For general purposes, the alkali metal hydroxide can be pulverized to a particle size that passes throgh a 50 mesh sieve and used herein.

The nature of the fatty acid esters employed herein is not critical to the practice of this invention. Accordingly, the ester of any fatty acid or substituted fatty acid species with any alcohol or substituted alcohol species provides starting materials which can be used herein. It will be appreciated, of course, that some esters will react more rapidly than others. However, the present process has been found to be useful for saponifying even substantially inert esters such as the sucrose fatty octaesters, which demonstrates the exceptional efficacy of this reaction as a saponification process.

In the practice of this invention it is convenient to employ a stoichiometic amount of the alkali metal hydroxide and ester to be saponified. For most purposes, an excess of the alkali metal hydroxide is employed to ensure that the reaction is carried to completion and that no ester is wasted. The alkyl nitrile is generally used in a solvent amount, i.e., sufficient to dissolve the acid ester. In some instances, the acid ester may not be entirely soluble in the alkyl nitrile and a ternary, heterogeneous reaction mixture of alkali metal hydroxide/ alkyl nitrile/acid ester is formed. It does not appear to be necessary for the reaction mixture to be homogeneous, and excellent yields of the alkali metal salts of fatty acids are secured even under such conditions.

In an alternate mode, an excess of ester is used, and the mixture of any unreacted ester and alkyl nitrile is simply re-used with fresh alkali metal hydroxide in subsequent processes.

This avoids the need for any acid neutralization step to remove excess base during soap recovery.

It has been found that the process of this invention, when restricted to the preparation of the sodium and lithium salts of organic acids, can be carried out using a concentrated aqueous solution of the corresponding alkali metal hydroxide in a liquid reaction medium comprising an alkyl nitrile compound. The amount of water introduced into the total reaction mixture is controlled to provide filterable, solid, yet partially hydrated organic acid salts. If too much water is employed, the reaction proceeds at a much slower rate, the reaction product is converted from a solid form to a tacky, intractable mass and the overall advantages of the process are lost. The process wherein the reaction medium is "substantially water-free" is thus an essential feature of the present invention.

It will be appreciated that small amounts (usually less than about 10% of the alkyl nitrile) of extraneous organic solvents and/or water may contaminate the reaction systems used in any commercial scale soap making process. Excessive amounts of such extraneous materials may cause an undesirable dilution of the alkyl nitrile/alkali metal hydroxide base medium. Moreover, solvents which are miscible with the alkyl nitrile may solvate the alkali metal hydroxide and diminish the overall reactivity of the system Thus, the presence of excessive amounts of extraneous materials is preferably avoided herein to assure that the special advantages of the process are obtained.

The saponification reaction of this invention is conveniently carried out at weight ratio or,organic acid ester: alkali metal hydroxide: alkyl nitrile in the range of from about 1:0.1:1 to about 1:1:5,but other ratios can be used, as desired.

After recovery of the reaction product by filtration, air drying can be used to remove any entrained alkyl nitrile.

When using the anhydrous soap made by this invention as a drying agent for wet crutcher mixes, all manner detersive surfactants and auxiliary detersive agents may be incorporated in said crutcher mixes. These materials are described in detail below.

DETERSIVE SURFACTANTS Typical anionic detersive surfactants which can be employed herein include water-soluble sulfates or sulfonates of the general formula R"' X- Q+ wherein R"'is an alkyl (including unsaturated alkyl), alkyl benzene or ethoxylated alkyl group, X is sulfate or sulfonate, and wherein Q is a counterion such as H+, or a cationic moiety chosen such that the anionic surfactant is water-soluble, e.g., alkali metals, ammonium, alkanolammonium, and the like. It will be recongnized that such anionic surfactants include the typical alkyl benzene sulfates and sulfonates, alkyl sulfates and sulfonates, and ethoxylated alkyl either sulfates and sulfonates well known in the detergency arts. Such anionic surfactants are readily available from a variety of well-known commercial processes and sources.

Mixtures of the foregoing anionic surfactans can also be employed herein. The preferred anionic surfactants herein include the C1 0-C1 8 alkyl benzene sulfates; C1 0-C1 8 alkyl benzene sulfonates; Cl 0-C1 8 alkyl sulfates; C1 0-C1 8 alkyl sulfonates; ethoxylated C1 0-C1 alkyl ether sultates; and ethoxylated C1 0-C1 8 alkyl ether sulfonates.

Anionic surfactants can be employed herein in their free acid form. However, inasmuch as detergency performance in an aqueous liquor is usually substantially higher at basic PH's the anionic surfactants are generally used in the form of their water-soluble salts.

The alkyl benzene sulfate and sulfonate surfactants employed herein can be, for example, sodium dodecylbenzene suflate; potassium dodecylbenzene sulfonate; triethanolammonium tetradecylbenzene sulfonate; ammonium hexadecylbenzene sulfate; ammonium hexadecylbenzene sulfonate; and diethanolammonium octadecylbenzene sulfonate. The alkyl group can either be in straight chain or branched chain configuration.

As in the case of the alkyl benzene-based anionic surfactants, the alkyl sulfates and sulfonates are most commonly employed in the form of water-soluble salts, with the sodium salt being the most preferred. Specific examples of preferred alkyl sulfates the sulfonates include sodium tetradecyl sulfate; annonium tetradecyl sulfate; sodium hexadecly sulfate; triethanolammonium hexadecyl sulfonate; monoethanolammonium octadecyl sulfate; triethanolammonium octadecyl sulfate and sodium octadecyl sulfate.

As with the alkyl benzene-based anionic surfactants, mixtures of the alkyl sulfates and sulfonates can also be employed herein.

A third type of typical detersive anionic surfactant useful in the present invention encompasses the ethoxylated alkyl ether sulfates and sulfonates. Typically, such materials comprise a C1 0-C1 alkyl group which is ethoxylated with from 1 to about 20, more preferably 3 to about 10, ethoxyl groups, which are subsequently sulfated or sulfonated at the terminal position of the molecule. As with the alkyl sulfates, such ethoxylated materials can be mixtures resulting from the use of mixed alkyl feedstocks such as the coconut alcohols or tallow-based alcohols.

Nonionic detersive surfactants employed in the present invention are, typically, condensation products of relatively long-chain ethylene oxide moieties with primary alcohols, secondary alcohols, or alkyl phenols. Such nonionic surfactants are well known in the detergency art.

More specifically, nonionic detersive surfactants of the formula R"' (E0) x' wherein: R"' is a straight- or branched-chain hydrocarbyl moiety derived from a primary or secondary alcohol containing from about 8 to about 20, more preferably from about 10 to about 18, carbon atoms, or an alkyl phenol-based moiety wherein the alkyl chain is straight or branched and contains from about 6 to about 12 carbon atoms; EO is the standard abbreviation for the ethylene oxide moiety; and wherein subscript x denotes the degree of polymerization of the ethylene oxide moiety and is an integer in the range from about 1 to about 20, preferably 3 to about 9, can be used herein.

Specific, non-limiting examples of such nonionic surfacants include the following: n-C10 (EO)3, n-Clz (EO)9,n-C 14(EO)12, n-C10 (EO 15,n-C12 (EO)20,n-C12 (EO)3, sec-Clo (EO)9, sec-C12 (EO)12, sec-C14 (EO)20, sec-Cz0 (EO)3, decyl benzene (EO)9, dodecyl benzene (EO)15, tetradecyl benzene (EO)20, and the like.

The foregoing pure nonionic detersive surfactants, and mixtures thereof, are all useful herein.

Examples of commercial nonionic detersive surfactants herein include: "Dobanol" (Trade Mark) 91-8; "Dobanol" 9112: Neodol 01 El 2 (C10-11 alcohol avg. 12 EO groups), and the <RT and polyvalent metal ions such as calcium, magnesium and iron; and a crystallization seed (0.001-20 micron diameter) which comprises a material which will not completely dissolve in water within 120 seconds at 25 C.

Specific examples of materials capable of forming the water-insoluble reaction product include the water-soluble salts of carbonates, bicarbonates, sesquicarbonates, silicates, aluminates and oxalates. The alkali metal, especially sodium, salts of the foregoing materials are preferred for convenience and economy.

The crystallization seed employed in such seeded builders is preferably selected from the group consisting of calcium carbonate; calcium and magnesium oxalates;barium sulfate; calcium, magnesium and aluminum silicates; calcium and magnesium oxides; calcium and magnesium salts of fatty acids having 12 to 22 carbon atoms; calcium and magnesium hydroxides; calcium fluoride; and barium carbonate.

The complex aluminosilicates, i.e., zeolitetype materials, are another useful type of detergency builder in the present process and compositions, since these materials readily soften water, i.e., remove Ca hardness. Both the naturally-occurring and synthetic "zeolites", especially the zeolite A and hydrated zeolitie A materials, are useful for this builder/softener purpose. A description of zeolite A materials and a method of preparation appears in U.S. Patent 2,882,243, entitled MOLECULAR SIEVE ADSORBENTS, issued April 14, 1959.

The aqueous crutcher mixes used in the present process can also contain all manner of detergency adjunct materials and carriers commonly found in laundering and cleaning compositions. For example, various perfumes, optical bleaches, fillers, anti-caking agents, fabric softeners and the like can be present to provide the usual benefits occasioned by the use of such materials in detergent compositions.

Perborate bleaches commonly employed in European detergent compositions can also be present as a component of detergent compositions prepared in the present manner, and are thereto as dry admixes.

Enzymes, especially the thermally stable proteolytic and lipolytic enzymes used in laundry detergents, can be dry-mixed in the compositions prepared herein.

As can be seen from the foregoing, soap and non-soap detergent compositions prepared in the manner of this invention can contain all manner of commonly-used ingredients typically employed in fully-formulated, free-flowing, powdered flaked and granular cleansing compositions and toilet bars.

Compositions which contain any of the phosphatebased, nitrilotriacetate-based or zeolite-based builders are especially preferred for detergency use and are readily prepared in the manner of this invention. The Peterson process drying agent soaps can be used to adjust the moisture content of such compositions to any desired level, depending on the intended end use of the finished product.

The process of the drying aspect of this invention may be carried out by preparing an aqueous crutcher mix comprising water, a wet soap or non-soap synthetic detersive surfactant, optional builders and auxiliary agents, etc., according to the desires of the formulator. The mixture is slurried until homogenous. The Peterson process drying agent soap is added to the mix in a quantity sufficient to adjust the total moisture content to the desired level. It will be appreciated that the process herein can be carried out using conventional apparatus used in the detergent industry.

The following examples illustrate the practice of this invention, but are not intended to be limiting thereof.

EXAMPLE I: Reaction of Triglycerides with Anhydrous sodium Hydroxid To a mixture of 50g. (0.067 mole) of a 50:50 mixture of tallow and coconut fats in 250 mls. of acetonitrile at a temperature of 75"C, was added 8.15 g. (0.20 mole) of finely powdered 98% sodium hydroxide. The reaction was exothermic and refluxed vigorously, without extraneous heating, about two minutes after the addition of the sodium hydroxide.

The reaction mixture was stirred at reflux temperature for a total of five minutes. During this time, a layer of fine, white solid powdered material formed in the reaction vessel.

The solid material was collected by filtration and air dried overnight to give a yield of 46 g.

(88%) of the sodium carboxylates (soaps) corresponding to the fatty acids in the starting material triglycerides.

In the process of Example 1 the acetonitrile is replaced by an equivalent amount of benzonitrile (C6 H5 CN) and no apparent reaction occurs.

In the process of Example I the fats are reacted with less than a stoichiometric amount of sodium hydroxide to provide "super-fatted" soap.

The sodium soap prepared in this manner is substantially anhydrous and is suitable for use as a drying agent in the practice of the drying aspect of this invention.

In the process of Example I, the solid NaOH is replaced by an equivalent amount of powdered LiOH. H2 O, KOH, RbOH and CsOH, respectively, and substantially dry soaps are secured. These dry soaps are also suitable for use as a drying agent in the practice of the drying agent aspect of this invention.

EXAMPLE II Reaction of Tallow and Coconut Triglycerides with Sodium Hydroxide To a stirred mixture of 100 g. (0.125 mole) of 80% tallow-20% coconut triglycerides and 500 mls. of acetonitrile at 600C was added 16.3 g. (0.40 mole) of finely powdered 98% sodium hydroxide. The reaction mixture was stirred for three hours. Intermittent heating was used to maintain a reflux temperature (80 C-820C).

The foregoing reaction mixture was filtered hot and the filter cake washed twice with 100 ml. portions of acetonitrile. The resulting white solids were air dried overnight to give 100 g. (97%) of the sodium salts of the fatty acids from the mixed triglycerides.

The acetonitrile solution was evaporated to a residue of 14 g. From this residue, 5.9 g.

(51%) of glycerine was recovered by vacuum distillation.

As can be seen from the foregoing, the soap making process of the present invention gives yields on the order of 90%, or, if external heating is used in addition to the heat generated by the reaction process, yields on the order of 97% can be secured.

EXAMPLE III: Preparation of Potassium Myristate To a solution 12.2 g. (0.05 mole) of methyl myristate in 120 mls. of acetonitrile was added 3.3 g. (0.05 mole) of finely pulverized 859 potassium hydroxide. The reaction mixture was stirred at substantially room temperature and monitored by following the rate of disappearance of methyl myristate by gas phase chromotographic analysis. After six hours, methyl myristate was no longer detectable. The precipitated sodium myristate was isolated by vacuum filtration and air dried overnight. A yield of 12.8 g. (96%) of solid potassium myristate product was secured.

In the process of Example ill, the KOII is replaced by an equivalent amount of LOLL, NaOM, RbOH and CsOll, respectively, and the respective alkali metal soaps are secured.

The process of Example III is carried out with the acetonitrile being replaced by an equivalent amount of propionitrile, butyronitrile, n-pentylinitrile and cyclohexylnitrile, respectively, and equivalent results are secured. Saponification reactions carried out using the higher alkyl nitriles (greater than about C6 alkyl) are much slower than with the preferred lower alkyl nitriles.

EXAMPLE IV: Preparation of Lithium Carboxylare To a suspension of 50 g. (0.054 mole) of hydrogenated caster oil in 250 mls. of acetonitrile at 700C was added 6.8 g.

(0.162 mole) of lithium hydroxide monohydrated. The reaction mixture was stirred for 21 hours at reflux (81"C). The product which precipated from solution was isolated by vacuum filtration of the hot reaction mixture and was dried in a vaccum desiccator. Product yield was 49 g. (98%) of the corresponding lithium carboxylate, predominately 12hydroxystearate, lithium salt.

EXAMPLE V Preparation ofBar Soap The substantially anhydrous soap prepared in the manner of Example I herein is in a phase which is useful, once hydrated, to form bar soaps in the ordinary manner, as follows.

Ingredient wt. % Soap (Na form)* 79.0 Coconut Oil Fatty Acids 7.0 Sodium Chloride 1.0 TiO2 0.25 Water 10.75 Minors** Balance * Prepared in the manner of Example I ** Perfume, coloring, perfume stabilizer A composition of the foregoing type is extruded through a standard soap making extruder and formed into bars, using commercial bar soap processing techniques.

An excellent soap bar product which compares favourably with commercially available soaps and comprising about 10% by weight water is secured.

The anhydrous soaps prepared in the manner of this invention are in a convenient granular form and are particularly adapted for use in mechanical dispensers, such as those found in public lavatories.

EXAMPLE VI: Saponification ofDimethylAdipate 17.4 g. (0.1 mole) of dimethyl adipate were dissolved in 100 mls. of acetonitrile and heated to 700C 8.2. g. (0.2 mole) of 97% pure sodium hydroxide were added to the reaction mixture as a fine powder (50 mesh). The reaction mixture was stirred at reflux temperature for 18 hours. The resulting solution was filtered hot and the solids were air dried to yield disodium adipate as the reaction procuct.

The foregoing illustrates that the process herein is useful for saponifying diacid esters.

EXAMPLE VII: Preparation ofBar Soap A bar soap composition is prepared in the manner of this invention, as follows.

Ingredient Wt. % Sodium soap* 48 Sodium soap** 48 Stearic acid 1.5 TiO2 (opacifier) 0.5 Perfume and minors Balance * Wet process soap comprising ca. 22% by weight water ** Anhydrous sodium soap prepared in the manner of Example I, herein The foregoing ingredients are admixed thoroughly in a standard soap-maker's plodder extruded through a soap-maker's extruder and fashioned into toilet bars using standard equipment.

A toilet bar prepared in the foregoing manner is not "smeary" or tacky and is suitable for use without further drying.

In the composition of Example VII, the anhydrous sodium soap drying agent is replaced by an equivalent amout of the potassium myristate prepared in the manner of Example III, herein, and an excellent bar soap is secured without further drying.

EXAMPLE VIII Laundry Detergent Composition A laundry detergent composition is prepared in the manner of this invention of this invention, as follows.

A mixture comprising: 1 part by weight C12-13 (avg.) alkyl benzene sulfonate, sodium salt; 1 part by weight sodium tripholyphosphate; 1 part by weight sodium sulfate; 0.1 part by weight minors; and 5 parts by weight water is mixed thoroughly in a soap catcher. After a homogeneous slurry is secured, the substantially anhydrous sodium soap drying agent (prepared in the manner of Example I, herein) is added to the crutcher mix in powder from (ca. 500-1500 micron) and blended thoroughly there with. Sufficient anhydrous soap is added to adjust the water content to ca. 10%-i 2% by weight of the total crutcher mix. The soap absorbs the water in the crutcher mix to provide a mass having a substantially dry "feel" and appearance. The mass is granulated with conventional equipment to a homogeneous detergent composition which is suitable for use in fabric laundering operations without further drying.

In example above the C1 2-1 3 (avg.) alkyl benzene sulfonate, soldium salt is replaced by C1 18 LAS, sodium salt; sodium tripolyphosphate is replaced by an equivalent amount of sodium nitrilotriacetate or hydrated Zeolite A (1-10 micron particle size range); and 0.5 parts of Kyro EOB (commercial nonionic surfactant) is added to the crutcher mix. Water content is adjusted to ca. 6%8% of the total crutcher mix by the addition of the anhydrous soap for Example I. Equivalent results are obtained.

WHAT WE CLAIM IS: 1. A process for preparing the alkali metal salts of organic acids which comprises saponifying the corresponding organic acid ester with an alkali metal hydroxide in a liquid reaction medium comprising a substantially water-free alkyl nitrile.

2. A process accoring to Claim 1 wherein the organic acid ester is a glyceride ester.

3. A process according to Claim 2 wherein the glyceride ester is a triglyceride.

4. A process according to Claim 1 wherein the alkali metal hydroxide is a member selected from the group consisting of lithium hydroxide, sodium hydroxide, and potassium hydroxide.

5. A process according to Claim 1 wherein the alkyl nitrile is a member selected from the group consisting of acetonitrile and propionitrile.

6. A process according to Claim 1 for preparing lubricating greases comprising saponifying an ester of a C10- C24 organic acid with lithium hydroxide in a substantially water-free alkyl nitrile reaction medium.

7. A process according to Claim 6 wherein the organic acid ester is a glyceride ester.

8. Process according to claim 7 wherein the glyceride ester is a triglyceride.

9. A process according to Claim 6 wherein the alkyl nitrile is a member selected from the group consisting of acetonitrile and propionitrile.

10. A process according to Claim 6 wherein the alkyl nitrile is acetonitrile and wherein the ester comprises the mixed glyceride esters derived from animal fats and oils or vegetable fats and oils.

11. A process according to Claim 1 for making soap comprising saponifying an ester of a Cl 0-C20 organic acid with sodium hydroxide or potassium hydroxide in a liquid reaction medium comprising a substantially water-free alkyl nitrile.

12. A process according to Claim 11 wherein the organic acid ester is a glyceride ester.

13. A process according to Claim 12 wherein the glyceride ester is triglyceride.

14. A process according to Claim 11 wherein the alkyl nitrile is a member selected from the group consisting of acetonitrile and propionitrile.

15. A process according to Claim 11 wherein the alkyl is acetonitrile and wherein the ester comprises the mixed glyceride esters derived from animal fats and oils or vegetable fats and oils.

16. A process according to Claim 15 wherein the alkyl nitrile is acetonitrile and wherein the alkali metal hydroxide is sodium hydroxide.

17. An energy-saving process for adjusting the water-content of wet soaps or wet crutcher mixes to a lower total content by adding thereto a quantity of a drying agent which comprises a soap having a low water content which is prepared by saponifying carboxylic acid essters with alkali metal hydroxides in a liquid reaction medium which comprises a substantially water-free alkyl nitrile.

18. A process according to Claim 17 wherein the drying agent is prepared by saponifying glyceride or otherester of a C1 0-C2 o fatty acid, or mixture thereof, with an alkali metal hydroxide which is a member selected from the group consisting of lithium hydroxide, sodium hydroxide, and potassium hydroxide.

19. A process according to Claim 18 wherein the glyceride comprises the mixed glyceride esters derived from animal fats and oils or vegetable fats and oils.

20. A process according to any of Claims 17 to 19 wherein the alkyl nitrile is acetonitrile.

21. A process according to any of Claims 17 to 20 wherein the wet soap is non-soap detersive anionic surfactant.

22. A process according to Claim 21 wherein the non-soap anionic detersive surfac

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (28)

**WARNING** start of CLMS field may overlap end of DESC **. myristate prepared in the manner of Example III, herein, and an excellent bar soap is secured without further drying. EXAMPLE VIII Laundry Detergent Composition A laundry detergent composition is prepared in the manner of this invention of this invention, as follows. A mixture comprising: 1 part by weight C12-13 (avg.) alkyl benzene sulfonate, sodium salt; 1 part by weight sodium tripholyphosphate; 1 part by weight sodium sulfate; 0.1 part by weight minors; and 5 parts by weight water is mixed thoroughly in a soap catcher. After a homogeneous slurry is secured, the substantially anhydrous sodium soap drying agent (prepared in the manner of Example I, herein) is added to the crutcher mix in powder from (ca. 500-1500 micron) and blended thoroughly there with. Sufficient anhydrous soap is added to adjust the water content to ca. 10%-i 2% by weight of the total crutcher mix. The soap absorbs the water in the crutcher mix to provide a mass having a substantially dry "feel" and appearance. The mass is granulated with conventional equipment to a homogeneous detergent composition which is suitable for use in fabric laundering operations without further drying. In example above the C1 2-1 3 (avg.) alkyl benzene sulfonate, soldium salt is replaced by C1 18 LAS, sodium salt; sodium tripolyphosphate is replaced by an equivalent amount of sodium nitrilotriacetate or hydrated Zeolite A (1-10 micron particle size range); and 0.5 parts of Kyro EOB (commercial nonionic surfactant) is added to the crutcher mix. Water content is adjusted to ca. 6%8% of the total crutcher mix by the addition of the anhydrous soap for Example I. Equivalent results are obtained. WHAT WE CLAIM IS:

1. A process for preparing the alkali metal salts of organic acids which comprises saponifying the corresponding organic acid ester with an alkali metal hydroxide in a liquid reaction medium comprising a substantially water-free alkyl nitrile.

2. A process accoring to Claim 1 wherein the organic acid ester is a glyceride ester.

3. A process according to Claim 2 wherein the glyceride ester is a triglyceride.

4. A process according to Claim 1 wherein the alkali metal hydroxide is a member selected from the group consisting of lithium hydroxide, sodium hydroxide, and potassium hydroxide.

5. A process according to Claim 1 wherein the alkyl nitrile is a member selected from the group consisting of acetonitrile and propionitrile.

6. A process according to Claim 1 for preparing lubricating greases comprising saponifying an ester of a C10- C24 organic acid with lithium hydroxide in a substantially water-free alkyl nitrile reaction medium.

7. A process according to Claim 6 wherein the organic acid ester is a glyceride ester.

8. Process according to claim 7 wherein the glyceride ester is a triglyceride.

9. A process according to Claim 6 wherein the alkyl nitrile is a member selected from the group consisting of acetonitrile and propionitrile.

10. A process according to Claim 6 wherein the alkyl nitrile is acetonitrile and wherein the ester comprises the mixed glyceride esters derived from animal fats and oils or vegetable fats and oils.

11. A process according to Claim 1 for making soap comprising saponifying an ester of a Cl 0-C20 organic acid with sodium hydroxide or potassium hydroxide in a liquid reaction medium comprising a substantially water-free alkyl nitrile.

12. A process according to Claim 11 wherein the organic acid ester is a glyceride ester.

13. A process according to Claim 12 wherein the glyceride ester is triglyceride.

14. A process according to Claim 11 wherein the alkyl nitrile is a member selected from the group consisting of acetonitrile and propionitrile.

15. A process according to Claim 11 wherein the alkyl is acetonitrile and wherein the ester comprises the mixed glyceride esters derived from animal fats and oils or vegetable fats and oils.

16. A process according to Claim 15 wherein the alkyl nitrile is acetonitrile and wherein the alkali metal hydroxide is sodium hydroxide.

17. An energy-saving process for adjusting the water-content of wet soaps or wet crutcher mixes to a lower total content by adding thereto a quantity of a drying agent which comprises a soap having a low water content which is prepared by saponifying carboxylic acid essters with alkali metal hydroxides in a liquid reaction medium which comprises a substantially water-free alkyl nitrile.

18. A process according to Claim 17 wherein the drying agent is prepared by saponifying glyceride or otherester of a C1 0-C2 o fatty acid, or mixture thereof, with an alkali metal hydroxide which is a member selected from the group consisting of lithium hydroxide, sodium hydroxide, and potassium hydroxide.

19. A process according to Claim 18 wherein the glyceride comprises the mixed glyceride esters derived from animal fats and oils or vegetable fats and oils.

20. A process according to any of Claims 17 to 19 wherein the alkyl nitrile is acetonitrile.

21. A process according to any of Claims 17 to 20 wherein the wet soap is non-soap detersive anionic surfactant.

22. A process according to Claim 21 wherein the non-soap anionic detersive surfac

tant is a water-soluble alkyl benzene sulfate or sulfonate.

23. A process according to any of Claims 17 to 22 wherein the wet crutcher mix comprises a wet soap or a wet non-soap detersive surfactant and auxiliary detersive agents.

24. A process according to Claim 23 wherein the auxiliary detersive agents are detergency builders.

25. A process according to Claim 24 wherein the builders are selected from phosphate-based builders, nitrilo-triacetatebased builders and zeolite-based builders.

26. A process according to Claim 1 or 17, when carried out substantially as described in any one of the Examples.

27. An alkali metal salt of an organic acid.

when prepared by the process of any of Claims 1 to 16 and 26.

28. A composition of matter when prepared by the process of any of claim 17 to 26.