US2285422A - Emulsion - Google Patents

Description

Patented June 9, 1942 azsazz EMULSION Albert R. Epstein and Benjamin R'Harris,

Chicagm'm. I

No Drawing. Application February 12,1940,

Serial N0.'313,592

16 Claims.

sifying agents of numerous types have been uti-' lized. While the stability of these emulsions is enhanced by the addition of saidemulsifying agents, still, in many instances, the improvements have not been sufflciently marked so as to provide a completely satisfactory solution to the problems confronting those'versed in the art.

Among the numerous emulsifying agents whose use has been suggested for enhancing the stability of oleaginous-aqueous emulsions are the higher molecular weight aliphatic alcohol sulphates and sulphonates, the sulphonated oils such as Turkey-red oil, the sulphates and phosphates of higher fatty acid monoglycerides, sugars and sugar derivatives such as sugar alcohols partially esterified with higher molecular weight aliphatic and particularly fatty acids, and the like. None of these agents is fully satisfactory since, among other things. the emulsions tend'to separate on prolonged standing,

In accordance with the present invention, it

has been found that the dispersing or emulsifying properties of the partial higher aliphatic or fatty acid esters of sugars and sugar derivatives, as hereinafter described in detail, may be markedly enhanced if used in conjunction with glycerol or a polyglycerol and especially also in conjunction with a sugar or a glycerol or polyglycerol-starch or dextrin complex, produced as hereinafter described. The exact mechanism of the reaction has not been ascertained but it has been repeatedly demonstrated that the enhancement of the stabilizing action on emulsions of the partial esters of the sugars and sugar derivatives is'startling.

The following examples will make clear the manner of'practicing the present invention. It

is to be understood, however, that the examples are only illustrative and are not to be construed as limitative of the invention in any manner. Thus, for example, different oleaginous-aqueous emulsions may be treated, different partial esters of sugars and sugar derivatives may be employed, the proportions of the materials used may vary,

and other 'changes may be made without departing from the spirit and teachings of the invention herein.

Example I 161 grams of substantially dry glycerol were-- heated to 160 degrees C. and 39 grams of sucrose were added theretoywith stirring. The tempera;

ture of the mixing dropped to degrees C;

and the mass was allowed to cool to room temperature while stirring. The resulting glycerolsucrose solution was a viscbus, transparent mass. To 5 grams of corn 011 1.7 grams of the oleic acid -mono-ester of sorbitan (sorbitan mono-oleate) were added and to the resulting solution was added 43.3 grams of the glycerol-sucrose solution, the mass being triturated or otherwise thoroughly mixed. In order to obtain the best results, trituration should be employed. Colloid mills or the like may also be utilized but are not necessary. This base material emulsion containing 10% corn oil, 3.4% of the oleic acid monoester of sorbitan, about 17.3% sucrose, and the balance essentially glycerol is characterized by extraordinary stability. This emulsion may be distributed as such for subsequent dilution or dispersion with further proportions of glycerol or other non-aqueous, water-miscible liquid or with aqueous material or may initially be dispersed or emulsified or diluted with water, milk or other aqueous material and distributed in that form. The amount of aqueous material with which the so-called base material emulsionmay be treated may be varied within relatively wide limits. Thus, for examp1e,.relatively stable dispersions or emulsions have been obtained with dilutions of the order of 1 part of the base material emulsion to from 10 to 40 parts of aqueous material.-

employed such as vitamin-containing fish liver oils as, for example, salmon liver oil, codliver oil, fortified or not with irradiated ergosterol or other sources of vitamin D, or other vitamins such as vitamins A and K. Again, the oleaginous material may be corn oil or other suitable animal or vegetable oil to which has been added a desired amount of a concentrate or vitamin A and/or vitamin D. Surprisingly enough, the vitamins exert their desired effects, when taken into the human system, the presence of the sorbitan monooleate or similar esters having no adverse effect thereon, a condition not true where certain other known stabilizing or emulsifying agents have been utilized for this purpose.

Example II 80 grams of substantially anhydrous glycerol were heated to 110 degrees C. to 115 degrees C. and 20 grams of anhydrous dextrose were added thereto and stirred therein until a clear solution was obtained. The solution was allowed to cool and 85 grams thereof were triturated with a mixture of 10 grams of corn oil and 5 grams of sorbitan mono-oleate. The resulting base-material emulsion contained corn oil, 5%

sorbitan mono-oleate, 17% dextrose, and the balance glycerol. It could be stored almost indefinitely as such or diluted substantially with water and the stability of the resulting emulsion was of the order of that of Example 1.

Example III A base-material emulsion-was made up in exactly the manner described in Example II with the exception that dextrose mono-oleate was substituted for the sorbitan mono-oleate. When one part of said base-material emulsion was diluted with from 10 to 40 parts of water, an-

emulsion was obtained having excellent stability over a period of several days. I

Example IV Example V A base-material was made up in exactly the manner described in Example 11 with the exception that sucrose mono-oleate was substituted for the sorbitan mono-oleate. The product was a non-aqueous emulsion of extreme stability and produced emulsions of good stability when diluted with water in various amounts. v

In place of the glycerol utilized in the above examples, it has been found that polyglycerols such as diglycerols, triglycerols and the like polymerization products of glycerol, or mixtures of polyglycerols, may be employed with good results. Furthermore, instead of using sucrose or dextrose, as described in the examples hereinabove, other crystalloidal sugars may be em ployed as well as, in certain cases, sugar alcohols such as sorbitol, mannitol, sorbitan, mannitan, dulcitol, and the like. It should be understood, in this latter connection, that, for some purposes, the sugar may be omitted so that the base composition would contain only the oil or other water-rcpellant material, the glycerol or the like, and the sorbitan mono-oleate or similer compound. However, since, in general, superior results are obtained when the sugar or the like is employed, it will be understood that this phase of the invention is regarded as being of particular value.

The sugars and sugar derivatives whose partial higher molecular weight aliphatic or fatty acid esters are employed herein as dispersing or emulsifying agents include monosaccharides, disaccharides, polysaccharides, sugar alcohols and anhydride derivatives thereof, celluloses, starches, dextrins, inulin, glucosides, glucoside derivatives, and the like. In addition to or as examples of those previously mentioned, are the following, it being understood that the list is by no means intended to be exhaustive: dextrose,

- where the essential alcohol structure is not altered. Still other sugar derivatives are the carboxylic oxidation products such as mucic acid, gulonic acid, gluconic acid, saccharic acid, mannonic acid, glucuronic acid, and the like; dextrose-glycerol glucoside, galactose-sorbital glucoside, and the like.

The sugars or sugar alcohols which are used as such, in conjunction with the glycerol or polyglycerol and the partial esters of the sugars or sugar derivatives, in the preparation of the stable oleaginous-aqueous emulsions or base-material emulsions -of water-repelling substances with water-soluble substances may be selected from a wide group including many of those previously mentioned..- Dextrose and sucrose, because of their ready water-solubility and commercial availability at low cost, are particularly preferred.

It has -been pointed out hereinabove that glycerol or a polyglycerol is employed in the preparation of the emulsions. The polyglycerols are polymerization products of glycerol and are preferably prepared, inaccordance with practices known in the art, by heating glycerol at elevated temperatures, preferably in the presence of an inert gas and an alkali catalyst. As previously stated, the polyglycerols may comprise diglycerols, triglycerols, tetraglycerols and higher polymers, as well as mixtures thereof. Polymers having a meanmolecular weight of the order of about 166, which corresponds to a diglycerol, have been found to be especially satisfactory. Condensation or polymerization products of glycerol or polyglycerob and sugars, of glycerol or polyglycerols with sugar alcohols such as those mentemperature of 160 degrees C. to 180 degrees C.

whereupon a homogeneous, viscous, jelly-like mass is obtained. Again, by way of example, 80 parts of anhydrous glycerol and 20 parts of de'xtrin, by weight, may be heated for about 1 ,4; hours at degrees C. to degrees C. and a viscous product obtained which may be used with excellent results in the practice of the present invention.

The higher molecular weight aliphatic (including cycloaliphatic) or fatty acids which are esterlinked to the sugars and sugar derivatives contain at least eight carbon atoms and preferably from twelve to eighteen carbon atoms, illustrative examples of which are: straight chain and branched chain, saturated and unsaturated, acids including caproic acid, capric acid, mellssic acid, stearic acid, oleic acid, ricinoleic acid, ricinelaidic acid, ricinostearoliic 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, rapeseedoil, sesame oil, palm kernel oil, palm oil, olive oil, corn oil, cottonseed oil, sardine oil, tallow, soya-bean oil, peanut oil, castor oil, seal oils, while oil, shark oil and other fish oils, partially or completely hydrogenated animal and vegetable oils such-as those mentioned; naphthenic acid; hydroxy and alpha-hydroxy higher carboxylic, aliphatic and fatty acids such as i-hydroxy stearic acid, dihydroxypalmitic acid, alpha-hydroxy stearic acid, alpha-hydroxy palmitic acid, alpha-hydroxy lauric acid, alpha-hydroxy myristic acid, alphahydroxy coconut oil mixed fatty acids, alphahydroxy margaric acid, alpha-hydroxy arachidic acid, and the like. It will be understood that mixtures of any two or more of said acids may be employed if desired. If the preparation is to be used for human consumption, it is advisable to utilize the edible fatty acids derived from corn oil, sesame oil, cottonseed oil, or other edible vegetable oils or fats which are free from objectionable odors. Oieic acid is especially satisfactory.

sugar derivatives are, in general, known in the art and form no part of the present invention, a detailed description of the preparation of such esters is unnecessary. It may be stated, however, that, in general, they may be prepared by reacting a higher molecular weight fatty acid acyl halide with the sugar or sugar derivative, in proportions such as to esterify only a portion of the hydroxy groups of the sugar or sugar derivative leaving at least one and preferably a minimum of two free or unesterified hydroxy groups in the final ester molecule. The reaction is effected in the presence or a basic material such as quinoline, quinaldine, pyridine, dimethyl aniline, caustic soda, potash or the like which serves to neutralize the halogen acid which is liberated during the reaction. The final ester is then preferably purified in ways known in the art. Of especial utility are the normally liquid esters or those which are plastic at room temperatures, the unsaturated higher fatty acid esters and particularly the oleic acid esters or products comprising largely oleic acid esters being especially satisfactory. The esters contain at least one, and preferably a minimum of two free or unesterifled hydroxyl groups. In general, the higher fatty acid mono-esters or products comprising largely such esters function most efi'ectively, mannitan mono-oleate and sorbitan mono-oleate having particularly desirable properties when used in accordance with the teachings of the present invention.

The invention is of utility in connection with the preparation of emulsions or dispersions of water-repellent materials and aqueous materials or aqueous-soluble materials and especially oleaginous-aqueous emulsions whether said emulsions be of plastic or liquid character. The invention is of particular advantage in connection with the stabilization of normally liquid emulsions wherein the aqueous material constitutes the continuous phase. the emulsions may comprise any of the common animal and vegetable oils and fats such as cottonseed oil, corn oil, cocoanut oil, peanut oil,

fish oils such as cod liver-oil, halibut-liver 011,

salmon-liver oil; fish oil vitamin concentrates; carotene, irradiated ergosterol, and other sources of fat-soluble or oil-soluble vitamins such as vitamins A and D; waxes, lanolin or wool fat, mineral oils, and other materials of water-repellant or oleaginous character.

The proportions of the stabilizing agents added to or incorporated into the emulsions are subject to relatively wide variation, the amount utilized being dependent upon the potency of the particular agents selected, the specific character of the emulsion in which they are utilized, and the particular results desired. In general, the partial esters of the sugars or sugar derivatives may vary from about 10% to about 50%, based on the weight of the water-repellent or oleaginous constituent or constituents of the emulsions. These proportions will be suitable for most purposes but, if desired, the same may be increased. Since, however, good results are obtained when using the smaller percentages, it is preferred to do so, particularly in view of. economic and other considerations. From 10% to 35%, based on the weight of the oleaginous or similar constituent, will serve efiectually in most cases.

The proportions of glycerol or polyglycerol and the sugar or sugar alcoholare also subject to variation, the amounts selected depending upon the factors set out hereinabove in connection with the esters. There is, however, a relationship between the amount of the ester and the amounts of the glycerol or polyglycerol and sugar or sugar alcohol which should be observed in order to obtain the best results. As a general rule, from about 10% to about 25% of sugar or sugar alcohol and from about 60% to about 85% of the base mixture of glycerol or polyglycerol will produce satisfactory results.

The term higher," as used herein and in the claims to describe aliphatic and fatty acids will be understood to mean at least eight carbon atoms unless otherwise stated.

The term a glycerol, as used in the claims, will be understood to include glycerol or polyglycerols or mixtures thereof.

The term emulsion, as used in the claims, will be understood to include both emulsions as well as dispersions of organic water-repellent substances with aqueous media as well as nonaqueous media immiscible with the water-repel lant substances.

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

l. A composition of matter, in the form of an emulsion of an organic water-repellent material and aqueous material, including a proportion of a glycerol, a member of the group consisting of sugars and sugar alcohols, and a member selected from the group consisting of sugars and sugar derivatives only partially esterified with an aliphatic acid containing at least eight carbon atoms.

The oleaginous phase of 2. A composition of matter, in the form of a liquid emulsion of triglyceride oleaginous material and aqueous material, including a proportion of aglycerol, a crystalloidal sugar, and a member selected from the group consisting of sugars and sugar derivatives only partially esterifled with fatty acids containing from twelve to eighteen carbon atoms.

3. A composition of matter, in the form of a liquid emulsion of triglyceride oleaginous material and aqueous material, including a proportion of glycerol, a crystalloidal sugar, and a member selected from the group consisting of sugars and sugar derivatives only partially esterified with oleic acid, the aqueous material constituting the continuous phase.

4. A composition of matter, in the form of a liquid emulsion of a vegetable triglyceride oil and aqueous material, including a proportion of glycerol, sucrose, and the oleic'acid mono-ester of sorbitan, the aqueous material constituting the continuous phase.

5. A composition of matter, adapted to be admixed with aqueous material to form an emulsion, comprising an organic water-repellant material, a proportion of a glycerol, a member'of the group consisting of sugars and sugar alcohols and a member selected from the group consisting of sugars and sugar derivatives only partially esterified with an aliphatic acid containing at least eight carbon atoms. w

6. A composition of matter, adapted to be/admixed with aqueous material to form an emulsion, comprising liquid triglyceride oleaginous material, a proportion ofa glycerol, 2. crystalloidal sugar, and a member selected from the group consisting of sugars and sugar derivatives only partially esterified with an unsaturated fatty acid containing from twelve to eighteen carbon atoms.

'7. An emulsion of oleaginous and aqueous materials including a proportion of a glycerol, sucrose, and a saccharide only partially esterifled with a fatty acid containing at least eight carbon atoms.

8. An emulsion of oleaginous and ayueous materials including a proportion-of a polyglycerol, sucrose, and a saccharide only partially esterified with fatty acid containing at least eight carwith a fatty acid containing at least eight carbon atoms.

-. 10. A composition of matter,'adapted to be admixed with aqueous material to form an emuln, comprising an oleaginous material, a prolortion bf a glycerol, sucrose, and a member acted from the group consisting of sugars and sugar derivatives only partially esterified with fatty acids Containing at least eight carbon atoms.

' 11. A composition of matter, adapted to be admixed with aqueous material to form an emulsion, comprising a triglyceride oil, a polyglycerol, a crystalloidal sugar, and a member selected from the group consisting of sugars and sugar derivatives only partially ester'fied with oleic acid. 12. A composition of matter, adapted to be admixed with aqueous material to form an emulsion, comprising a triglyceride oil, a glycerol, a crystalloidal sugar, and an oleic acid mono-ester of a member selected from the group consisting of sugars and sugar derivatives, said ester containing at least two free hydroxy groups.

13. A base for the preparation of emulsions of oleaginous and aqueous materials, comprising a triglyceride oil, a proportion of a polyglycerol, sucrose, and a member selected from the group consisting of sugars and sugar derivatives only partially esterified with normally liquid higher molecular weight fatty acids. I

14. A method of enhancing the stability of emulsions of oleaginous and aqueous materials which comprises including therein a proportion of a glycerol, a crystalloidal sugar, and'a member selected from the group consisting of sugars and sugar derivatives only partially esterlfled with fatty acids containing at least eight carbon atoms.

15. A method or enhancing the stability of liquid emulsions .of triglyceride oil and aqueous materials which comprises including therein a proportion of glycerol, sucrose, and oleic acid mono-esters of a member selected from the group consistingof sugars and sugar derivatives, said esters containing at least two free hydroxy groups.

16. A base for the preparation of emulsions of oleaginous and aqueous materials, comprising an oleaginous material, a member selected from the group consisting of condensation products of a glycerol with a member of the group consisting of starches and dextrins, and a member selected from the group consisting of sugars and sugar derivatives only partially esterified with an allphatic acid containing at least eight carbon atoms.

ALBERT K. EPSTEIN. BENJAMIN R. HARRIS.