US2247106A - Fatty acid salts of polyhydroxy amines - Google Patents

Description

Patented June 24,1941.

UNITED STATES PATENT OFFICE ra'rrr horn SALTS or POLYHYDROXY amass 1 Byron M. Vanderbilt, Terre Haute, lnd., assignor to Purdue Research Foundation, La Fayette.' hit, a corporation of Indiana No Drawing. Application August is, 1937,

Serial No, 158,954

6 Claims. '(cl. 260-404) My invention relates to salts of animohydroxy compounds useful as emulsifying agents, and the I like. a More particularly, it relates to higher fatty acid salts of the aminopolyhydroxy compounds useful as emulsifying agents.

these materialsyhowever, are such as to limit their general use.

I have now discovered that higher fatty acid salts of the-polyhydroxyamines areparticularly The term emulsion covers a wide variety of products of varying characters which consist essentially of particles or droplets of a liquid suspended'in another liquid. Familiar examples of emulsions ar homogeneous mixtures of oil or Such mixtures are ordinarily suspended in the water this type of emulsion is known as the oil-in-water (O/W) type. If the oil is the continuous phase of the emulsion and water droplets are suspended therein, the emul sion is the water-in-oil (W/O) type. The formertype may be readily diluted with water and the latter only with oil.

Emulsions often possess unusual and desirable properties per se. In many instances, however, they are employed as a means of obtaining suitable dilutions of various materials which may not be satisfactorily used in concentrated form.

Emulsifying agents are used commercially for the production of emulsions suitable for many pur-.

poses including. insecticides, disinfectants, or-

chard sprays, polishes, lotions, creams, inks, etc.

The selection of an emulsifying agent for a particular purpose'is determinedby such factors as stability of the. material, its tendency to affect unfavorably any of the-constituents of the dispersion, and theamounts required to give a dispersion of the desired character. It should have the property of keeping the emulsified materials in a dispersed condition for the desired period of time. Examples of emulsifying agents previously suggested for various purposes include such materials as sulfonated oils, sulfonated high molecular weight alcohols, triethanolamine salts of fattyacids, certain gums and proteins, polyhydric alcohols which have 'been incompletely esterified with high molecular weight may acids, metallic soaps, etc. .The properties of most of those produced by oil and water with the aid of some emulsifying agent. If the oil droplets are suited for use as emulsifying agents. The polyhydroxyamines which react with the fatty acids have the following general formula:

to form the emulsifying agents of my invention wherein X represents hydrogen, an alkyl or a methylol group; Y represents hydrogen or an alkyl group; and Z represents a hydrogen or, in,

case X is a hydrogen, Z may also represent an alkyl group.

These aminohydroxy compounds may be still further. defined as those aminohydroxy compounds obtainable by the catalytic reduction of the corresponding nitrohydroxy compounds which can be prepared by the action of aliphatic aldehydes on primary aliphatic nitroparaflins. The preparation of these compounds are described fully in U. S. Ser. No. 151,155 filed by B. M. Vanderbilt on June 30, 1937, and U. S.

Serial No. 151,841 filed by Kenneth Johnsonon July 3, 1937. Specific examples of aminohydroxy compounds included by this formula are 2 amino-2methylol-'1,3-propanediol, 2-amino-l,3- propanediol, 2-amino-2-methyl-1,3-propanediol, and 2-amino-2-isopropyl-1,3-propanediol.

These new emulsifying agents and emulsions containing them may be prepared in a variety of ways. If, for example, it is desired to use the salts of the-various hydroxyam'ines directly, they may be prepared by adding the amino compound to an equivalent amount of a higher fatty acid at room or elevated temperatures and in the presence or absence of an auxiliary solvent such as ethyl ether.v The salts thus prepared may be added directly to a mixture of oil and water with vigorous agitation. emulsions utilizing the salt of the aminohydroxy compound are prepared in one of the following ways: First, the amino compound and fatty acid are dissolved in a part of the oil and then the water and the rest of the oil are added alternately with good agitation. Second, a water, sov the amino compound and fatty acid in all of the oil is prepared which emulsifles spontaneously when added to water. Fourth, the emulsification Preferably, however,

is brought about instantly by stirring together two solutions, one of water and the amino compound, and the other of the oil and fatty acid.

The concentration of emulsifying agent to be used will vary widely depending upon the emulsifying agent employed, the emulsion to be prepared, the desired characteristics of the resulting emulsion, etc. I have found that fairly stable emulsions of naphtha and 90% water may be prepared by using as little as 175% of a salt of an aminohydroxy compound such as 2- amino-2-methylol-1,3-propanediol oleate or 2- amino-2-methyl-1,3-propanediol oleate, although for most purposes I prefer to use approximately 3.0% of the salt. Suitable concentrations of emulsifying agents for various emulsions may then diluted with 200 cc. of water, agitated vigorously for 3 minutes and allowed to stand at readily be determined by simple experimentawhile those containing fewer carbon atoms such as 2-amino-2-methyl-1,3-propanediol form the oil-in-water type emulsions. It will be readily recognized from the general structural formula given in the above that there are a lar e number of aminohydroxy compounds that may be employed as higher fatty acid salts according to the teaching of my invention. The choice of compound will depend to some extent upon the .type of emulsion to be prepared and the materials to be emulsified. Those higher aminohydroxy compounds which are insoluble in water, or nearly so, will, in general, not be so satisfactory as the lower ones of greatersolubility. The solubility of these compounds will depend upon the molecular weight, the number of hydroxyl groups present and the presence or absence of branched chains in the molecule.

In general, stoichiometric quantities of the room temperature.

The oleate of 2-amino-2-methyl-L3-propanediol gave a good O/W type emulsion'when used as indicated above which became slightly curdy in 3 days. If a 5% excess oleic acid was used when preparing the emulsion, two layers formed at once, and if 5% excess of the base was used, the 'O/W emulsion was stable for six days. When the stear'ate was used, layer separation occurred in a few hours. Similarly, the oleateof 2-amino-2-methylol-1,3-propanediol gave a good O/W type emulsion stable after six days, and the oleate of 2-amino-2-isopropyl--1,3-propanediol gave a very stable. emulsion of the W/O type.

It is to be understood that any of the higher fatty acids or mixtures thereof may be used for preparing the emulsifying agents of my invention.. For example, any of the fatty acids or mixtures thereof obtained .by. the saponiflcation vegetable or mineral .waxes, fats, oils, greases,

etc. The aqueous emulsions of these various oily materials are referred to in the appended claims aminohydroxy compound and fatty acid are -.used

to give the emulsifying agents of my invention in order to impart desirable properties to the emulsions produced but an excess of either material may be used without departing from the scope of my invention. In fact, a slight excess of one or the other constituent in certain cases gives more stable emulsions than when equivalent quantities of base and acid are used. Thus, in general, it may be stated that an excess of higher fatty acid used in the emulsifying agent will tend to increase the stability of a water-inoil emulsion, and, conversely, an excess of aminohydroxy compound will tend to lend more stability to an oil-in-water emulsion.

The following example will illustrate the method of producing my new emulsifying agents and their use in emulsions, but it is to be understood that the invention is not to be limited thereby: To 0.02 mole of the amino compound dissolved in 31 cc. of water there was added to 0.02 mole of oleic acid dissolved in 38 cc. of petroleum naphtha boiling at 160-175" C. The mixture was as oil-water emulsions, irrespective of whether they are oil-in-water emulsions or water-in-oil emulsions.

What I claim is:

1. A higher fatty acid salt of an aminohydroxy compound of the following general structural formula:

H x H r 1 wherein X represents a member of the class consisting of hydrogen, methylol and alkyl groups,

Y and Z represent members of the class consisting of hydrogen and alkyl groups, and wherein at least one of the constituents, X and Z, represents hydrogen.

2. A higher fatty acid salt of 2-amino-2- 6. The stearic acid salt of '2-amino-2-methyl- 1,3-propanediol.

' BYRON M. VANDERBILT.