US2291634A - Thickening of solutions - Google Patents

Description

Patented Aug. d, 1942 purine STATES PATENT QFFEQE f 2,291,634 THICKENING or sow'rioNs Chicago,

Chi-

cago, ill, a corporation of Illinois No Drawing; Application January 22, 1940,

Serial No. 315,028

15 Claims. -(Cl. 252-354) This invention relates to the thickening of solutions and is particularly concerned with the thickening of aqueous solutions of so-called interface modifiers.

in dealing with solutions of interface modifying agents which are known to the prior art, it frequently becomes highly desirable to increase the thickness, consistency or viscosity of said solutions. As an example, preparations have been produced in accordance with prior art teachings wherein an interface modifying agent having sudsing and detergent powers is dissolved in suitable solvent such as water or organic solvents such as alcohol or aqueous-organic solvents such as mixtures of water and alcohol. For meeting the demands of certain classes of trade, it is highly advisable to provide a product having s. relatively heavy consistency or an eninorganic acids and the salts of monoethanolhancerl thickness. While an increase in thickening may, certain cases, be accomplished by increasing the concentration of the interface modifying agent in its solvent, this becomes impracticable in most cases since the interface modifying agents are frequently soluble to only a limited extent in the particular solvent preferred to he used. In addition, the increase in the concentration of the interface modifying agents, aside from other disadvantages emanating from such practice, is usually uneconomic since the degree of enhancement of thickness 1 or increase in viscosity attainable by such method is insufificient to warrant the substantially greater cost invoived.

Solutions, ior example, aqueous solutions, containing as high as 25% or more, by weight, of

some interface modifying agents are almost as limpid as water. When poured from a bottle and handled, there is a marked tendency for loss of soiu'tion by spilling. It becomes highly advantageous in many instances to increase the thickness, consistency or viscosity of such and similar solutions to. facilitate the handling thereof and minimize the loss during pouring and the like from bottles or similar containers or receptacles. Other advantages accrue from the present invention into which it is not necessary to go into detail. I

t is, accordingly, an important object of the present inventionto increase thickness or viscosity of solutions of interface modifying agents in a relatively simple and inexpensive manner. A further object of the invention is to increase the thickness or viscosity of aqueous solutions of interface modifying agents which have high sudsing and detergent properties, which solutions may be employed for the same cleansing and washing purposes as are ordinary soaps.

Other objects and features of the invention will become apparent as the detailed description of the invention proceeds.

ethyl amine, cyclohexyl polyamines such as alkylol derivatives of ethyleneamine with water-soluble, aliphatic lower molecular weight carboxylic acids, especially monoethanolamine sulphate, monoethanolamihe phosphate, monoethanolamine citrate, monoethanolamine tartrate, monoethanolamine acetate, and monoethanolamine iormate.

In place of monoethanolamine, other organic nitrogenous bases may be employed as, for example, alcohol amines and alkylolamines, especially the monoalkylolamines, including diethanolamine, monoand di-propanolazmines, monoand dibutanolamine, monoand dipentanolamines, monoand di-hexanolamines, glycerolamines, dibutyl ethanolamine, diethanol ethanolamine, alkylol diam-ine, mono-methyl monoethanolamine, di= ethyl monoethanolamine; 1-amino-2,3-propanediol; 1,2-diamino propanol; Z-methylaminopropan-dio1-1,3; 1 phenylamino propan diol- 2,3; l-hydroxyethylamino-Z, methoxy-propano1 3; 2 N methylamino propan diol 1.3; hydroxyl-amine (NI-Iz-OH) and derivatives thereof; 2-amino-2-methyl-1,3-propanediol; trimetnylol amino methane; ,2-amino-2-n-propyl- 1,3 propanediol; 2 amino 2 isopropyl LS-propanediol; 2{amino-Z-ethyl-Lii-propanediol; 2 amino 2 methyl 1,4 butanediol; 2 amino 2 methyl 1,5 pentanediol; 2- amino 2 ethylol 1,3 propanediol; 2 amino- 2 methyl 1,6 hexanediol; alcohol amines derived from polyhydric alcohols,- including sugars and sugar alcohols such as dextrose, sucrose, sorbitol, mannitol and dulcitol; polymerized alkylolamines made, for example, by heating alkylolamines such as monoethanolamine or diethanolamine or mixtures thereof, or other alkylolamines such as described hereinabove, at elevated temperatures, preferably in the presence of a catalyst such as sodium hydroxide, the preparation of such polymerized alkylolamines being disclosed in United States Patent No. 2,178,173; alkylamines such as butylamine, dimethylamine, di-ethylene triamine, triethylene tetra-amine, mono-methyl ethylene diamine, mono-ethyl diethylene tetra-amine, aromatic and heterocyclic phates, phosphates, nitrates, formates, acetates,

chlorides, bromides, iodides, borates, benzoates, phthalates, lactates, citrates, succinates, tartrates, and the like or mixtures of any two or more thereof. The salts may be made in ways known in the art, for example, by neutralizing the base or mixtures of bases with the equivalent amount of acid or any desired mixture of two or more acids. For example, monoethanolamine acetate may be prepared by mixing equal molecular quantities of monoethanolamine and glacial acetic acid. The glacial acetic acid is' added drop by drop to the monoethanolamine while constantly stirring the latter, the flask or the like containing the monoethanolamine being surrounded by an ice bath to insure thatthe temperature does not rise too high and too rapidly. The monoethanolamine acetate is a brownish, viscous liquid. Monoethanolamine sulphate may be prepared in solution, for example, by adding a solution of 325 grams of monoethanolamine in 250 cc. of water to a solution of 2'73 grams of 96% sulphuric acid in 580 cc. of water.

As illustrative of thickeners falling within the scope of the invention may be mentioned, by way of example, in addition to those previously referred to, diethanolamine acetate; 1-amino-2,3 propanediol acetate; .l,3-diaminopropanol acetate; diethanolamine tartrate; butylamine tart'rate; diethanolamine formats; butylamine acetate, and the like.

It is convenient to prepare a solution of the thickener and add it in the desired amounts to the interface modifying agent solution although the manner of incorporation is optional and may be accomplished in various ways as, for example, in situ during the preparation of the solution of the interface modifying agent. Since, in the main, aqueous solutions of interface modifiers are employed, the thickeners utilized in such solutions will be water-soluble. It will be understood that in all cases the thickener must be soluble in the solution of the interface modifier in which it is employed.

The interface modifying agents whose solutions may be thickened by means of the compounds disclosed hereinabove are generally characterized by the presence of at least one higher molecular weight lipophile group containing preferably at least eight carbon atoms, preferably although not necessarily, aliphatic in character, and by the presence of at least one hydrophile or hydrophilic group, preferably in the form of an oxygenated sulphur, phosphorus or boron radical, particularly sulphur in the form of sulphate or sulphonic acid radicals, although, as will be seen, the hydrophilic group is not so limited.

Preferably, the lipophile and hydrophile groups are in a state of balance whereby the resulting ma mas-a compound has the property of reducing the spattering of margarine when used for frying. This concept of balance of lipophile and hydrophile groups is treated in considerable detail; in the patent to Benjamin R. Harris, No. 1,917,250, issued July 11, 1933, and need not here be elaborated upon iurther. While this "balance" may be determined empirically by means of a margarine frying test, as described in said patent,

those skilled in the art will, in most cases, readily be able to predict the existence of "balance" from merely an inspection of the molecule of the compounds themselves. As a general rule, the hydrophile and lipophile groups should preferably be, at the ends or extremities of the molecule as, for example, in the case of lauryl sodium sulphate wherein the lauryl group or, in other words, the lipophile group, is present at one end of the molecule, and the sulphate or hydrophile group is present at the other end of the molecule.

As previously indicated, the invention is particularly useful with respect to the thickening 01 solutions of those interface modifying agents which have good sudsing, foaming and detergent properties. This aspect of the invention will be come more apparent as the description proceeds. It will be understood that the term lipophile group includes groups having a definite afllnity for oils and fats and comprises, for example, alkyl, aralkyl, aryl, ether or ester groups containing preferably at least eight carbon atoms.- The lipophile group possesses predominantly hydrocarbon characteristics and, in general, is derived from triglyceride fats and oils, waxes, mineral oils, other hydrocarbons, and the like.

In contra-distinction thereto, the term hydrophile group or hydrophilic group includes groups which possess an afiinity for water and aqueous media. As examples of such groups may be mentioned the following: hydroxyl, hydroxylcarboxylic, sulphate, sulphonic, phosphate, pyrophosphate, tetraphosphate, borate, lower molecular weight sulphocarboxylic acids such as sulphoacetates, sulphopropionates, etc., and quaternary ammonium and other hydrophilic nitrogenous groups.

Among the interface modifying agents whose solutions may be thickened in accordance with the present invention are organic substances having balanced lipophile and hydrophile groups, the lipophile group containing at least eight carbon atoms and the hydrophile group comprising a radical selected from the class consisting of oxygenated sulphur, oxygenated phosphorus, and

- oxygenated boron inorganic acid radicals.

One sub-class thereof, several members of which have excellent sudsing, foaming, frothing, lathering, and detergent powers, comprises the higher molecular weight alcohol sulphates and sulphonates. The alcohols from which these sulphates and sulphonates may be prepared include the following: aliphatic straight chain and branched chain alcohols such as octyl alcohol, nonyl alcohol, dccyl alcohol, undecyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, oleyl alcohol, linoleyl alcohol, stearyl alcohol, ricinoleyl alcohol, palmitoleyl alcohol, melissyl alcohol, ceryl alcohol, carnaubyl alcohol, myricyl alcohol, branched chain octyl, dccyl, dodecyl, tetradecyl, hexadecyl and octadecyl aliphatic alcohols as, for example, 2-ethyl hexanol-l, 2-n butyl octanol-l, 2-butyl tetradeca- 1101-1, and, in general, the higher molecular weight saturated and unsaturated aliphatic straight chain and branched chain alcohols.

aeaaess Preferably, the alcohols which are utilized are those corresponding to the fatty acids occurring in triglyceride oils and fats of vegetable or animal origin, natural or hydrogenated, such as corn oil, cottonseed oil, sesame oil, toconut oil,

palm kernel oil, sunflower seed oil, lard, tallow,

soya bean oil and the like. those alcohols containing from 12 to 18 carbon atoms being preferred. Other alcohols which may be employed are the cyclo-aliphatic or all-cyclic alcohols such as the sterols, as, for example, cholesterol, iso-cholesterol, phytosterol, sitosterol, hydroaromatic alcohols such as abietol', and such unsaturated alcohols as linalool, citronellol, geraniol and the like. Also included within the class of alcohols which may be employed are such compounds as the hydroxy and alpha-hydroxy higher aliphatic and fatty acids as, for example, ricinoleic acid, alpha-hydroxy stearic acid, alpha-hydroxy lauric acid, di-hydroxy stearic acid, i-hydroxystearic acid, alpha-hydroxy palmitic acid, and the like, as well as esters of hydroxy-fatty acids, such as ethyl ricinoleate, castor oil, butyl alpha-hydroxystearate, cetyl hydroxystearate, and the like.

The term alcohols as employed herein, is

intended to include alcohols which may or may not contain other groups such as carboxylic, halogen, sulphonic, sulphate, or other radicals. The alcohols obtainable by substituting alkyl or acyl radicals, preferably of high molecular weight, in place of the hydrogen of one or more hydroxy groups of polyhydroxy substances or polyhydric alcohols, it being understood that at least one hydroxy group attached to the nucleus of the polyhydroxy substance or polyhydric alcohol remains, are also within the scope of the alcohols from which the sulphates and sulphonates may be produced. As examples of such alcohols may be mentioned partially esterlfied or partially etherified sugars and sugar alcohols such as monolauric acid ester of sucrose, monostearic acid ester of dextrose, monopalmitic acid ester of mannitol, dicaproic acid ester of maltose, monooctyl ether 01' sorbitol, monolauryl ether of pentaerythritol, monolauric acid ester of pentaerythritol, and the like; the monoglycerides and diglycerides, preferably of the higher fatty acids, as, for example, monolaurin, monomyristi n, monostearin, distearin, diolein, di-

caproin, mono-lauryl ether of glycerol, di-cetyl ether of glycerol, monostearic acid ester of diethylene glydol, monolauric acid ester of ethylene glycol, and the like.

It is, of course, obvious that the alcohols from which the sulphates and sulphonates may be produced may be prepared in accordance with any desired method. For example, many of these alcohols may be prepared by the so-called Bouveault and Blane method or, alternatively, by the reduction or catalytic reduction with hydrogen of natural or hydrogenated animal or vegetable fats and oils, or mixtures thereof, in accordance with well known practices. Again the alcohols may be derived from synthetic processes such as by the oxidation of hydrocarbons or may be prepared by saponification of waxes and the like. Alternatively, they may be prepared by reduction of aldehydes or by the Grignard reaction.

It is likewise apparent that mixtures of the -foregoing or other alcohols may be utilized in the preparation of the sulphates and sulphonates as, for example, the mixture of alcohols result-v ing from the hydrogenation of coconut oil or the free fatty acids of coconut oil., Lauryl alcohol comprises about 45% of the total alcohol mixture, the remaining alcoholsrunning from Co to Cu. Again, mixtures of alcohols such as are present in the so-called sperm oil alcohols, as well as those present in wool-fat, may equally emcaciously be utilized. Indeed, these higher molecular weight alcohols are generally offered on the market in the form of mixtures of different alcohols. If desired, for any specific purpose, special fractions which predominate in a certain particular higher molecular weight alcohol may be utilized or, if so desired, the products may be prepared from a single, substantially pure alcohol.

These sulphates and sulphonates, described hereinabove, may, in general, be represented by the formula wherein R is a radical containing a hydrocarbon chain of at least eight carbon atoms, X is a sulphuric or sulphonic group present at or near an extremity of the radical represented by R, Y is a cation or the radical of a salt forming compound, and n is a small whole number, at

least one. v

In a still more specific aspect of this subclass of compounds, the sulphates may be represented by the formula wherein R represents the residue of a normal primary alcohol containing from 8 to 18 carbon atoms, Y represents a cation or the residue of a salt forming compound such as sodium, triethanolamine or the like, and n is a small whole number, at least one. v

The sulphates and sulphonates described are preferably utilized in the form of salts and, in their preparation, the acid sulphuric ester or sulphonic acid may be neutralized, in whole or in part, with suitable anti-acid materials. In this connection, considerable latitude and modification may be exercised. In general, inorganic as well as organic anti-acid agents may be employed. Examples of such agents which may be used satisfactorily are bicarbonates of the alkali metals, potassium hydroxide, sodium oxide, sodium carbonate, ammonium hydroxide, ammonia gas, potassium stearate, sodium stearate, magnesium oxide, magnesium carbonate, organic anti-acid nitrogenous materials including amines and alkylolamines such as, for example, mono-, di, and triethanolamine and mixtures. thereof, propanolamines, butanolamines, polynitrogenous amines such as ethylene diamine, ethylene triamine and the like, pyridine, piperidine, quaternary ammonium bases such as tetra-ethyl ammonium hydroxide, tetra-methyl ammonium hydroxide, and in general, primary, secondary and tertiary amines substituted or not with other radicals such as hydroxy groups, and the like. It will be understood that by the term cation, as used throughout the specification and claims, is meant hydrogen and such other elements as are mentioned herein, and, in general, atoms or radicals which are regarded as bearing a positive charge or capable of replacing acidic hydrogen. The reaction products may be neutralizedto methyl orange, litmus or phenolphthalein. As a general rule, if the salts of the reaction products are employed, it is preferred to use the sodium, potassium, ammonium, triethanolamine, quaternary ammonium, or other relatively highly soluble salts.

The sulphates and sulphonates disclosed hereinabove are described, among other places, in the following United States patents: 1,897,741; 1,968,793; 1,968,794; 1,968,796; 1,968,797; 2,006, 309; 2,023,387; 2,052,027; and 2,077,005.

Another sub-class of interface modifying agents whose solutions may be thickened are those compounds which correspond to the higher molecular weight alcohol, sulphates and sulphonates described hereinabove but wherein the hydrophile group comprises oxygenated phosphorus instead of oxygenated sulphur. Among these compounds may be mentioned lauryl pyrophos- 'phate, palmityl orthophosphate, sodium lauryl tetraphosphate, stearyl triethanolamine ortho-' phosphate, oleyl monoethanolamine pyrophosphate. monolauric acid ester of diethylene glycol tetraphosphate, monoethanolamine salt, and the like. As in the case of the sulphates and sulphonates described previously, it is generally prererred to employ the oxygenated phosphorus derivatives in the form of their alkali, ammonium, or nitrogenous base or alkylolamine salts. These compounds are disclosed, among other places, in the following United States patents: 2,026,785; 2,052,029; 2,053,653; 2,128,946; and 2,177,650.

Again, in place of either the oxygenated phosphorus or oxygenated sulphur compounds, similar as well as corresponding oxygenated boron compounds may be employed. These include boric acid esters of higher molecular weight alcohols such as lauryl borate, cetyl borate, and boric acid esters of monoglycerides of higher fatty acids such as monostearin borate. For a more complete description of such or similar compounds, reference may be made to United States Patent No. 2,052,192.

Another class of interface modifying agents whose solutions may be thickened in accordance with the principles of the present invention are the lower molecular weight sulphocarboxylic acid esters of higher molecular weight alcohols such as those described hereinabove. Among these compounds may be mentioned octyl sulphoacetate, lauryl sulphoacetate monoethanolamine or triethanolamine salt or other organic nitrogenous base salts such as those described hereinabove, cetyl potassium sulphoacetate, and the like. For a more complete description of such compounds, reference may be had to the following United States Patents Nos. 1,917,250; 2,166,141; 2,166,142; 2,166,143;- and 2,185,455; and British Patent No. 377,249.

Another class of interface modifying agents whose solutions may be effectively thickened in accordance with the teachings of the present invention are the salts, such as the alkali metal salts, of the sulphoacetates of halogenated lauryi alcohol, as disclosed in the application of Benjamin R. Harris et al., Serial No. 308,578, filed December 11, 1939, now Patent No. 2,251,932.

Still another class of interface modifying agents whose solutions may be thickened in accordance with the teachings of the present invention are the compounds which correspond to the general formulae 1. R co-NX..(YM

wherein R is an aliphatic hydrocarbon radical containing at least 7 carbon atoms and preferably between 11 and 17 carbon atoms, X is hydrogen, n is either zero or one, Y is a lower aacresc molecular weight hydrocarbon radical such as *C2H4--, -CsHe- -C4Hs or the like, M is an oxygenatedsulphur-containing inorganic acid radical such as 0S0;Na

SOaN8 CHLOE -0SO3'N-C:H|OH

CJHIOH ,SO:NC:HOH

H canon 0 or the like, and w is a small whole number. As

illustrative of these compounds may be men tioned the following: 7

These compounds and others of similar nature are disclosed in the following United States patents: 1,981,792; 1,931,540; 1,932,177; and 1,932,180.

, It will be understood that the radical R in the above general formulae may be derived from higher aliphatic, fatty, cycloaliphatic, aromatic, and hydroaromatic acids such as the following: caproic acid, capric acid, saturated and unsaturated higher molecular weight aliphatic acids such as the higher fatty acids containing at least eight carbon atoms and including melissic acid, stearic acid, oleic acid, ricinoleic acid, linoleic acid, linolenic acid, lauric acid, myristic acid, palmitic acid, mixtures of any two or more of the above mentioned acids or other acids, mixed higher fatty acids derived from animal or vegetable sources, for example, lard, coconut oil, sesame oil, corn oil, cottonseed oil, sardine oil, tallow, partially or completely hydrogenated animal and vegetable oils such as those mentioned; hydroxy and alpha-hydroxy higher aliphatic and fatty acids such as i-hydroxy stearic acid, dihydroxystearic acid, alpha-hydroxy stearic acid, alpha-hydroxy palmitic acid, alpha-hydroxy lauric acid, alpha-hydroxy coconut oil mixed fatty acids, and the like; aliphatic acids derived from various waxes such as beeswax, spermaceti, montan wax, and carnauba wax and higher molecular weight carboxylic acids derived, by oxidation and other methods, from petroleum, hydroaromatic acids such as abietic acid; aromatic acids such as naphthoic acid, hydroxy aromatic acids such as hydroxy naphthoic acids, and the like.

Still another class of interface modifiers whose 7 disclosed therein may wherein R1 represents an aliphatic radical, such as hydrocarbon radical or the radical of a poiy= hydric alcohol linked to an alml or acyi group in the form of an ester or an ether, in each case said aliphatic radical containing at least eight carbon atoms, R2, R3, and R4 are hydrogen or hydrocarbon groups which of a heterocyclic ring, and X represents halogen or other anions such as OH-g 'I-ISOr, R604, CsHsSOs, borate, phosphate, nitrate, acetate, etc. Among the specific substances falling within this general class are cetyl trimethyl ammonium bromide or chloride, lauryl pyridinium bromide or iodide, cetyl pyridinium iodide, lauryl trimethyl ammonium chloride or iodide, monooleic acid ester of diethylene glycol pyridinium chloride, octadecyl pyridinium bromide, octyl pyridinium chloride; i dodecyl, Nmethy1- quinaldinium-methylsulphate, N-ethyl triethanolamin mono-oleate-bromide, salts of higher molecular weight bctaine esters, etc.

A somewhat similar class of quaternar ammonium compounds, which are interface modify-, ing agents and whos solutions may be thickened in accordance with the teachings of this invention, is that disclosed in the patent to Benjamin R. Harris, No. 2,023,075. Among the compounds be mentioned, for example, dodecyl ester of betaine chloride, cetyl ester of betaine chloride, octyl ester of betaine bromide, and cholesteryl ester of betaine bromide.

Still another class of interface modifying agents whose solutions may be thickened by means of the thickening agents disclosed herein comprises the sulphonium and phosphonium compounds corresponding, in general, to th quaternary ammonium compounds previously disclosed. Among these compounds may be men= tioned dodecyl dimethyl sulphonium bromide, methyl butyl ,octadecyl sulphonium chloride, hexadecyl triethyl phosphonium bromide, and dodecyl trimethyl more complete disclosure of this type of compound, reference may be had to United States Patent No. 2,061,621.

Other sulphonium compounds falling into the category of interface modifying agents whose solutions may be thickened are those compounds corresponding to the general formula phosphonium bromide. For a.

wherein R1 is an aliphatic lipophile radical linked to the sulphur through a member of the group consisting of aliphatic ester and ether derivatives ofaliphatic polyhydroxy substances, R2 and R: are radicals or the group consisting or alkyl, aryl, aralkyl, cyclic, heterocyclic, and alkylol, X is an anion, and a is a small whole number. As illustrative or such compoun, the following are may be components listed:

0 0 Cl OKs-C 9 R--O-CHi-CHOH-CHs-O-A-Cfir 0 CHr-Cs E I (R- -istheecylradicaloiccconut ilmixdi .aci prising predominately lam-is acid) 0 6 any as i CuHza( J-OCEs-'JEH Che-CH3 HOCEiC K (3) CE,-CEOH-CH 0H O CuHas--O-CHz-CHOH-CHr-CHa-CHOH-CHAXEI c Compounds of this class are disclosed in the patent to Benj Harris, No. 2,193,963.

Another class oi sulphur-containing interface modifying agents the thickening of whose solu tions may be efiected in teachings of the present invention comprises those compounds which correspond, in general,

to the formula zr-o-X -s-x -Y wherein X and X represent members selected from the class consisting of alkylene and substituted alkylene groups, Z represents a lipophilic group, and Y represents a hydrophilic group such as hydroxyl, sulphate, sulphonic, phosphate, phosphonic, and the like. Illustrative of such compounds are the following:

ta o-$01110 other compounds of this class are disclosed in the copending application of Benjamin B. Harris, Serial No. 157,949, ent No. 2,201,535.

A further class of interface modifying agents whose solutions may be thickened by means of the thickening agents of the present invention comprises higher molecular weight carboxylic acids and derivatives thereof wherein at least one hydrogen attached to the carbon atom adjacent to the carboxyl group of said carboxylic acids is replaced by a radical having strong hydrophilic properties, particularly hydrophilic radicals comprising orqrgenated sulphur and oxyaccordance with the filed August '1; 1937, now Patgenated phosphorus. pounds are as follows: (1 CH3-(CH2)H CH-COONB CHy-(CHz)lsCH-COOK CHa-(CHflu-CHf-COONB V SOaNa k Qther compounds falling into this category are disclosed in United States Patent No. 2,185,541.

Again, the thickening agents of the present invention may be employed for thickening interface modifying agentswhich fall into the category of sulphonated triglyceride .oils, the best known of which are the so-called Turkey-red oils. The products are so well known as to require no further discussioneor' description.

Still another class of interface modifying agents whose solutions may be thickened in accordance with the teachings of the present invention comprises compounds of the type disclosed in the United States patent to Benjamin E. Harris, No. 2,025,984. These comprise esters of aliphatic lipophile carboxylic acids with aliphatic hydroxycarboxylic acids, the esters containing at least one unesterified carboxyl group in the hydroxy carboxylic acid radical. Examples of such compounds are monostearic acid ester of citric acid, monolauric acid ester of Examples of such com- 'malic acid, and monopalmitic acid ester of mucic acid.

Another group of compounds whose salts and particularly whose organic nitrogenous base salts may be thickened in accordance with the present invention are those disclosed in United States Patent No. 2,184,770, At least most of the compounds disclosed in said patent correspond to the following general formula:

wherein R is an organic radical containing at least four carbon atoms, alk and Z are each members selected from the class consisting of I hydrocarbon radicals and substitution products thereof, Y is a member selected from the group consisting of hydrogen, alkyl, cycloalkyl, alkoxyl, aralkyl, aryl, and alkylol, m and w are whole numbers, and X is a sulphonic radical. A more specific aspect of said compounds is represented by the general formula I Rc0-e1k.-Ncz X wherein 0 ll nc is an aliphatic acyl radical containing at least eight carbon atoms, alk is hydrocarbon, Y is a member selected from the group consisting of hydrogen, alkyl, cycloalkyl, alkoxyl, aralkyl, aryl, and alkylol, Z is a hydrocarbon residue, and X is a sulphonic group.

Other representative compounds, some 01 which are disclosed in Patents Nos. 2,176,896 and 2,178,139, whose salts, and especially whose organic nitrogenous base salts, may be thickened in accordance with the process of the present invention, comprise the following:

\ accuses 1 a) cnn -i-nn-ctmr-nn-fi-om-rf t Y It will, of course, be appreciated that the various thickening agents vary in their potency. The amount to be employed will accordingly be deo 1. not only by thisfact but also will be dependent upon the specific character and concentration of the interface modifying agent in the solution thereot, and. the particular results desired. As illustrative, while, as indicated, the ratio of potency of specific thickeners may vary with the specific system Lute which such thickeners are introduced, in general the monoethanolamine salts are of the order of at least several times the potency of the corresponding dieoline salts in their thickening power and. many more times the potency of the corresponding triethanolamine salts.

e, as stated and as is obvious, the amount of. thickener which may be employed. is variable within relatively wide ranges of proportions, in order to indicate the rlzable and unusual aspects of this phase of the invention, the following facts should be understood. Aqueous solutions of the thicken agenhi, or substantially all of the same, which are disclosed herein, even in concentrations as high as 50%, are ot a very lirnpid character with viscosity practically identical with or not much greater than that of ordinary water. Nevertheless, the addition of relatlvely small proportions of such limpid solutions to interiac'e modifying agent solutions results in an entirely unexpected increase in thickness and viscosity of said latter solutions; That this happens in the lace oi and notwithstan the mutual dilution which ultaneously occurs is all the more remarkable. The following table illustrates the nature of the results which have been elated:

Interface modifier solution Addition agent Results 10 cc. of a 10% aqueous solution 01 trietlianolemine salt 0! lauiryl sulphoecetete.

10 cc. oi

lauryl sulphate.

. lourylsul hate 10 cc. of a 40% aqueous suzliphonate, sodium salt.

10 cc. of s 40% aqueous solution of isopzopylnaphthalene suliphonato, sodium salt.

10 cc. of a 25% aqueous solution 0! luuryl sulphate, triethanolamine 10 cc. of a 15% aqueous solution of CnHnC ONHCH;-CH SO;Na

10 cc. of an aqueous solution of rather low viscosity containing 2}% of the triethanolamine salt of leuryl-sulplio acetate and 136% of triethanolamme phosphate.

10 cc. of a 25% aqueous solution of sodium octylsulphate 5 cc. of a 14% aqueous solution of monoethanolamine salt of lauryls'ulphoacetate. 5 cc. of a 25% aqueous solution of tnethanolamine salt of lauryl sulphate. 5 cc. of a 15% aqueous solution of CnHorC 0-NH-CHr-CH:S oiNu 10 cc. of a 15% aqueous solution of fiESE 1 gram monoethanolamlne acetate Considerable increase in viscosity.

grams monoethanolamlne sulphate 2 Small amount of monoethanolamine aoetate.

Small amount of diethanolamine acetate Small amount of trletlmnolamine acetate Small amount of 1-amlno-2, S-propanediol acetate. Small amount of 1,2-dlamiuopropsnol acetate- Small amount of monoethanolamine acetate 1 Do. Appreciuble thickeng Do. Do. Do.

Do. Do.

Do. Do. Do.

Small amount 0! diethanolamine acetate Small amount of triethanolamlne acetate Small amount of 1-umino2, 3-propanediol acetate. Small amount of 1,2-diaminopropauol hate. 10 cc. of a aqueous solution of amouetheuol- Very viscous solution.

amine phosphate (neutral to litmus).

Several drops of a 50% aqueous solution of Considerable thickenetlianolamine phosphate. mg. 5 cc. of a 50% aqueous solution of ethylene- Appreciable thicken- :liamine sulphate. ing. Mo cc. of a 50% aqueous solution of butylamlne Considerable thickenacetate. ing. 340 cc. (go 50% aqueous solution of butylamme Do. Do.

aceta $40 cc. of e 50% aqueous solution of butylamine acetate.

8 cc. of a 509',1 aqueous solution of ethylene- Clear, thick solution.

diomine sul ate.

g oneness Interface modifier solution Addition agent Results I 10 e. 11 us solution of laur l idinium iodide... 5 cc. oi a 507 aqueous solution of monethanol- Appreciable increase 5 cc of a q 60 y pw amine phosphate. in viscosity. 25 5 cc. of a 15% aqueous solution of 5 cc. of a 50% aqueous solution of monethanol- Do.

amino phosphate. a C1|Hm OCHQ-CHsOCH:CHr-O=O Ne 27 cc. of a 32% aqueous solution of a tetra-phosphate ol 5 cc. of c. 50% aqueous solution of moueothanol- Do.

amine pnosphete. CllH23 JJ O cH3'TCH3 O CH.T CH2 oH Monoethauolamine salt t la 12 a ueous solution of I 5 cc. of a aqueous solution or monoethanol- Considerable increase 23 cc 0 q amine .lil 'fim. in viscosity.

C]1H2.," C|o CHPCH2 0 C CH2 =O NHz KEHPCHZOH 2o cc. of a 12% aqueous solution of monoethanolemine salt of 1 cc. of u 50% aqueous solution of monoethanol- Do.

lauryl sulphoaoetete. ammo citrate. do 1 cc. of a 58% aqueous solution or diethnnol- Slight thickening.

amine citrate. ice. of a 50% aqueous solution of monoethanol- Considerable increase amine tnrtrete. in viscosity 1 cc. of 50% aqueous solution oi diethanol- Slight thickening.

amine tartrate.

1 cc. of 50% aqueous solution of butylamine Substantial increase in tartrate ckness.

1 cc. of 50% a ueous solution of monoethanol- Very considerable inamine ecete crease in thickness. 1 cc. of 50% aqueous solution of diethanolnmine Apprcciable increase in acetate. thickness. 1 cc. of 50% aqueous solution of monoethanol- Very considerable inemine formate. crease in thickness. 1 cc. of 50% aqueous solution of diethanolamine Appreciable increase in formate. thickness. 38 10 cc. i s 108% aqueous solution of monoethanolamiue salt of 1 cc. of 50% aqueous solution of butylamine Considerable increase SUJLSJOZMZGHC acid amide 0i lauric acid ester oi monoethanoltartrete. Lil viscosity. amino.

0 O 0 g [5 ll CuH2a -0-C2H4NH -CH2S =0 HOCsH4NH2.H

39 10 cc. of a 20% aqueous solution oi lauryl sodium sulphate 1 cc. of 50% aqueous solution of monoethanol- Substantial increase in aznme acetate. thickness. 40 do l0 oc. of 60% aqueous solution of monoethanol- Considerable increase amine fcrmate. in thickness.

As further indicative of the character of the trate in conjunction with the 12% aqueous soluthickening which may result from. the practice tion of the monoethanolamine salt of lauryl sulof the invention, reference may be made to the phoacetate, the thickness measured 67.4 secabove list of examples. With a, given capillary ends; and using the same thickener with a. 19.8% tube, it required 3.2 seconds for a. given volume aqueous solution of the monoethanolamine salt of water to pass therethrough. The same vol- I of the sulphoacetic acid amide of the lnuric acid ume of a 12% aqueous solution 'ofthe monoester of monoethanolamine, the thickness of said ethanolamine salt of lauryl sulphoacetate reletter solution was increased from 4 seconds to quired 5.2 seconds to pass through said capillary 532 seconds. In all or the cases described in tube. A 50% aqueous solution of monoethanolthis and the immediately preceding paragraph,

amine acetate was substantially as limpid as only 1 cc. of a 50% aqueous solution of the thickwater. Yet the addition of only 1 cc. of the monener was added to 10 cc. of the solution of the oethanolamine acetate to 10 cc. of the 12% interface modifying agents and, as pointed out aqueous solution of the monoethanolamine' salt previously, the thickener solution was substanof lauryl sulphoacetate increased the thickness tially as limpid as water.

or viscosity of the latter solution to such an ex- It will be seen that, by the selection of certain tent that it required 1422 seconds for the given thickeners and certain interface modifiers, and volume to pass through the same capillary tube. by varying the proportions or concentrations Using diethanolamine acetate as the thickener, thereof, the increase in thickness or viscosity can the viscosity or thickness, measured in seconds be readily controlled to any desired value. In as described, was 22. Using monoethanolamine general, it is preferred to increase the thi k iormate as the thickener, the time was 2960 or viscosity of the interface modifying agent soseconds whereas, with diethanolamine formate, a5 lutions by at least several fold, preferably a minthe time was 25 seconds. imum of five-fold and usually at least ten-fold In the case of a 20% aqueous solution of the to fifty-fold.

interface modifying agent, lauryl sodium sul- While it is preferred to carry out the invenphate, the time was 3.5 seconds. The addition ticn with respect to the thickening of aqueous of monoethanolamine acetate, as described heresolutions of the interface modifying agents, it inabove, increased the thickness to 169.2 seconds must not be inferred that the invention is so and the use of monoethanolamine formate inlimited. Alcohols or other organic solvents may creased the thickness to 761.6 seconds. 0n the be employed, as well as aqueous-organic solvent other hand, butylamine tartrate increased the mixtures, but for economic and other obvious thickness to 28 seconds. Using butylamine tar- 76 reasons water is preferred.

ably herein and are intended m Qa-fl-L' r .l one term solution cs herein an the eopendai claims er 1 1 interface modifier and interface are employed interchangeto embrace sub-1 stances which comprise lipophile and hydropln'le groups and which are capable of reducing surface and interiacial tension, other than soaps or salts such as alkali metal salts of higher fatty acids.

While the thickening efiect increases with increasing concentrations of interface modifying agents and while it commences to become appreciable, in most cases, at concentrationsoi the order of magnitude of several percent or five to ten percent, nevertheless the invention is 'applicable, as well, at concentrations of interiace modifiers substantially below and beyond the above-mentioned range. Indeed, the invention is applicable to the treatment of solutions oi interface modifiers of as high as 25% or 30% strength, or even higher.

What we claim as new and desire to cover by Letters Patent of the United States is:

1 An aqueous solution of at least several per cent of an interface modifier having a lipophile group with at least eight carbon atoms and a hydrophile group, having good sudslng and detergent properties, containing a proportion of a salt of an organic acid with an organic nitroge= nous base, which salt is soluble in said solution, suficient to appreciably thicken the same, said salt being of a character such that strong aque= ous solutions thereof are not substantially less limpid than water.

2, A solution of at least 5% cl an interface modifier having a lipophlie group with at least eight carbon atoms and a hydrophile group, talning a proportion oi a salt oi an aliphatic acid with an organic nitrogenous base, which salt is soluble in said solution, sufficient to appreciably thicken the same, said salt being oi a character such that strong aqueous solutions thereof are not substantially less limpid than wamr.

3. A solution of at least 5% of a salt of an organic nitrogenous base salt of a sulphuric acid ester of an aliphatic alcohol having from eight to eighteen carbon atoms and containing a proportion of a salt of an organic nitrogenous base with a water-soluble. aliphatic acid, which latter salt is soluble in said solution, sufficient to appreciably thicken the same, said salt being of a character such that strong aqueous solutions thereof are not substantially less limpid than water.

l. A solution oi at least 5% of an alkylolamme salt of a sulphuric acid ester of a straight chain aliphatic alcohol having from eight to eighteen carbon atoms and containing a proportion of a salt oi an aliphatic organic nitrogenous base lil ill

oon-

with a water=soluble aliphatic acid, which latto: salt is soluble in said solution, suficlent appreciably thicken the some said salt being of a character such that strong aqueous solutions iiiereoi are not substantially less iimpid than 5. An aqueous solution or" at least 5% oi an al= kylolamine salt of the sulphuric acid ester of a mixture of alcohols derived from cocoanut oil and comprising predominantly lauryl alcohol, and containing a roportion oi a salt of mono ethanolamine with a water-soluble aliphatic acid, which latter salt is soluble in said solution, sufficient to a preciably thicken the same,

6. An aqueous solution of at least 5% of an ethanolalm'ne salt of the sulphuric acid esters of a mixture of higher aliphatic alcohols derived. from triglyceride oils or fats, and containing a pro ortion of a salt of an alkylolaniine with a water-soluble aliphatic acid, which latter salt is soluble in said solution, sufiiclent to appreciably thicken the same.

7. A solution of at least 5% of an interface modifying agent falling into the category or clients selected from the group of general formu- R-CO-NXc-(YMM wherein R is an aliphatic hydrocarbon radical containing at least 7 carbon atoms and preferably between 11 and 17 carbon atoms, X is hydrogen, n is zero or one, if is a lower molecular weight hydrocarbon radical, M is an oxygenated sulphur-containing inorganic acid radical, and 'w is a small whole number, and containing a proportion of a salt oi an organic nitrogenous base with a water-soluble aliphatic acid, which latter salt is soluble in said solution, sufficient to appreciably thicken the same.

8. An aqueous solution of at least 5% of an interface modifying agent having the general formula wherein n-i is the acyl radical of a higher iattlr acid containing 12 to 13 carbon atoms, and Z is a cation, and containing a proportion oi a salt of an organic nitrogenous base v 'th a water-soluble aliphatic acid, which latter salt is soluble in said solution, suficient to appreciably thicken the same.

9. An aqueous solution of at least 5% of an interface modifier having a lipophile group with at least eight carbon atoms and a hydrophile group, having good sudsing and detergent properties, and containing a proportion of a water-soluble salt of an alkylolamine with a water-soluble aliphatic acid, suficient to appreciably thicken the same.

10. An aqueous solution of at least 5% of an interface modifier having good sudsing and detergent properties and comprising an oxygenated sulphur derivative of a lipophile material having at least eight carbon atoms, and containing a proportion of a salt of an organic nitrogenous base with a water-soluble-aliphatic acid, which salt is soluble in said solution, suficlent the same.

to appreciably thicken the same, said salt being of'a character such that strong aqueous solutions thereof are not substantially less lim'pid than water.

11. An aqueous solution of at least of an containing a proportion of an acetic acid salt of an organic nitrogenous base which is soluble in said solution, sufficient to appreciably thicken 12. An aqueous solution organic nitrogenous base salt of an interface modifier having a Ilipophile group with at least eight carbon atoms anda' hydrophile group, said 7 solution containing a proportion of a salt of an organic nitrogenous base with a water-soluble 'rliphatic acid, 'whichsalt'is solublein said solution, sufiicient toappreciably 'thickenthe same,

said salt being of a character such that strong aqueous. solutions thereof are not substantially.

less limpid than water.

' 13'. An aqueous solution of at least 5% of an alkylolamine salt of an interface modifier having a lipophile group withat least eight carbon a water-soluble salt of a primary amine with a water-solublealiphatic acid, which latter salt is soluble said solution, sufifiicient to appreciably thicken the same, said salt being of a character such that strong aqueous solutions thereof are t I not substantially less limpid than water.

of at least 5% of an atoms and an oxygenated sulphur hydrophile -'group,. said solution containing a proportion of v alproportion of a salt 14. An aqueous solution of at least 5% of a salt ofa chemical compound corresponding to the general formula wherein R is an organic radical containing at least eight carbon atoms, all: and Z are each I members selected from,

the class consisting of hydrocarbon radicals and substitution products thereof, Y is a member selected from the group consisting of hydrogen, alkyla nd alkylol, m andw are whole numbers; and X is a. sulphonic radical the hydrogen of which is replaced. by an organic nitrogenous base; said solution containing phatic acid with a water-soluble organic nitrogenous base, which latter salt is soluble insaid solution, .suflicient to appreciably thicken the same. I g g I 15. An aqueous'solution of at least 5% of a monoethanolamine salt of the sulphoacetic acid amide of the lauric acid ester of monoethanoh' amine, and containing a proportion of a'salt of monoeth'anolamine with a'water-soluble' allphatic acid, whichlatter salt is soluble in said I solution, sufficient to appreciably thicken the a v r same.

- MORRIS 1B. KATZMAN. FRANK J. CAHN.

of a. water-soluble ali-