Patented Oct. 21, 1952 2,615,160

UNITED STATES PATENT OFFICE ; 2,615,160 MIXED-TRIGLYCERIDEs ; Fredric J. Baur, Wyoming, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio No Drawing. Application May 28, 1949, . Serial No. 96,143 19. Claims. (CI. 260-410.8) This invention relates to mixtures of high mo : I have found that mixtures of diacetyltriglyc i.lecular diacetyl triglycerides in-aiwaxy translu ... erides the non-acetyl acyl, radicals of which are cent form-and-to-ways of making them. of high molecular weight (i. e. those offatty-acids ; : In copendings application-Serial No. 96;150. of : of 12 to 22 carbon atoms) are capable of crystals * Frank L. Jackson, bearing even date herewith, 5. lizing in Waxy translucent form, and that when synthetically prepared high-molecular triglycer- . . at least ten per cent by weight of the diacetyl sides are'. described, having in their molecular triglycerides, in such mixtures are different in structure two acetyl groups attached to adjacent composition, or structure from the remainder of s' carbon atoms, of... the glyceryl radical...and...one ... the diacetyl triglycerides, this waxy translucent 's high molecular acyl group. (i.e.: containing: 12 to 0 form is of great, thermodynamic stability, being -22-carbon atoms)., attached to the third-glyceryl capable of existing for long periods of time or carbon. These tasymmetrical diacetyl-triglycer- indefinitely without transforming into the opaque sides are capable of solidifying in waxy...translu- ... solid-form in which conventional fats-exist at -cent-form, in which form they possess novel and itemperatures below their melting point. I have ruseful properties which distinguish them-from 15 furthermore discovered an inexpensive and com previously known fats. These -diacetyl.com.- ... mercially practicable process whereby such mix :-pounds' possess limitedi stability. .in, the waxy tures of diacetyl triglycerides may be prepared st translucent form, sufficient to make them service- in a purity which makes them suitable for cook - able for some purposes but limiting their serv- ling and other purposes. riceability for others; since they eventually lose 20. In a favored variant of my process of prepar - 'their waxy, translucent properties. Further- 'ing Such mixtures of: diacetyl triglycerides, the rimore, although Jackson has proposed methods first. Step is to rearrange molecularly the acyl of preparing diacetyl fats capable of assuming ... groups. in a mixture of triacetin and a conven the waxy translucent form, no-methods prior to ...tional fat, For this purpose the mixture is con my invention have been entirely satisfactory-for 25 tacted with a .rearrangement catalyst., Many i commercial practice. For example, chemical Such catalysts are known and may be used, such synthesis involving-reaction of -acetyl-lehloride "for example as water, alone at high temperature with an unsymmetrical-high molecular mono- ... and pressure, or the Soaps of alkali metals, zinc, '...' glyceride is undesirably costly. aluminum, tin or magnesium...However, I prefer It is an object of this invention to provide fats 30 low temperature: rearrangement... catalysts, by rt which may be solidified in waxy, translucentform. which I mean catalysts which are effective below - Another object is to provide such triglycerides 3.20 C., such as alkali metals or compounds whose which are either wholly-stable in waxy-trans cation is an alkali metal or a tetrasubstituted am i-lucent form or are stable in that form for long monium radical and whose anion is: the result of periods of time. ... Another object is to previde 35 removal of acidic hydrogen from any substance such triglycerides in the alpha-3 or the subalpha less, acidic than phenol. Thus finely divided me ... 3-polymorphics forms, to obes described sherein tallic Sodium or potassium in xylene, organhy - after.' Another object is to provide-mixtures of drolls Suspension of potassium hydroxide, in un - such...triglycerides;... Said mixtures containing a is decane may be used, or alkalimetal hydrides. : ; plurality. of combined high-molecular acyl- grOlipS. 40. Also, Suitable for this purpose are various alkox -c.Another-object is to provide mixtures of symmet vides Such as sodium, potassium and lithium meth rical and unsymmetrical: high molecular diacetyl oxides, ethoxides, propoxides and butoxides, as ... triglycerides. Another object is to...provide such ... are: also the corresponding alkoxides made from is mixtures.Which are 'substantially free from mono '... alcoholic compounds in general such as lauryl al . . glycerides, diglycerides, glycerol, fatty acids, tri 45 Cohol, ethylene glycol, glycerol, oleic acid mono it... acetin, or... triglycerides , containing...not acetyl glyceride and many others. Also suitable are al ... groups. Another object is to provide a novel-kind *:koxides in which the cation is the tetrasubstitut of edible fat. Another objectiisi to provide an ed ammonium radical such as: tetramethylam '...inexpensive and commercially practicable: proc monium. methoxide and lauryl benzyl dimethyl - ess whereby mixtures of symmetrical and unsym 50 ammonium methoxide, and alkali-metal-organic ... metrical high-molecular. diacetyl triglycerides Compounds. Containing the alkali metal: atom, di nay, be prepared linSynaetrical triglycerides be rectly, bound-to a carbon atom as in Striphenyl sing in predominant amount in Said mixtures and methyl sodium or to a nitrogenatom: as in po ...said mixtures being substantially-free from mono - tassium. pyrrole. Sodium alkoxides of monohy ... glycerides, diglycerides, glycerol, fatty acids, tri 55. dric alcohols of less than 5 carbon atoms (for ex aceting or triglycerides-containing .no-acetyl ample, Sodium methoxide and sodium, ethoxide) igroups. Other objects will appear hereinafter. -- are especially Satisfactory catalysts. The amount 2,615,160 3. 4 of Such low-temperature catalyst required in crystallize readily in waxy translucent form, the creases With the inoisture content of the fat. In rearranged mixture requires purification. Tri the case of Sodium methoxide or ethoxide the acetin is especially objectionable because it low- . amount commonly ranges from about 0.05 per ers the temperature at which the product smokes cent to about 0.5 per cent, based on the weight 5 When used for cooking purposes; it also softens of the fat, about 0.3 per cent being an average the product and expands the temperature range figure according to my experience. Such cata over which it melts. I therefore remove by lysts are usually suspended in xylene or other distillation substantially all unreacted triacetin low-boiling hydrocarbon which is miscible with or other low-boiling constituents which may re fats, the amount of Suspending liquid being non G main in the rearranged mixture after inactivat critical. ing the catalyst and washing, as previously de The low temperature catalyst is added to the Scribed. In order to avoid high temperatures dried fat (usually refined and bleached pre Which might cause decomposition, I carry out viously) or to the dry triacetin or to the mix this distillation under reduced pressure, pref ture of the two. Rearrangement is allowed to erably while passing a stream of inert gas, such proceed at a temperature So high that at east for example as nitrogen or steam, through the a substantial part of the fat is liquid, since Solid molten fat. Under a pressure of 2 or 3 mm. of fat does not readily undergo rearrangement with mercury, triacetin steam-distills readily before triacetin. As the reaction proceeds, the acetyl a temperature of 40° C. is reached. containing fats which are formed tend to dis I next isolate a distillation fraction consisting Solve any remaining Solid fats and thus enable predominantly of high molecular diacetyl tri them to take part in the reaction. However, in glycerides. in Order to do this, the temperature order to attain more rapid rearrangement, the of the Stearin distillation or other distillation is mixture is commonly heated to above the con raised and/or the pressure is reduced until diace plete melting point of the fat or until the mix 2 tyl triglycerides distill, but conditions drastic ture is completely liquid, although temperatures enough to cause distillation of substantial above 120° C. are avoided lest the activity of the amounts of tiriglycerides containing less than 2 catalyst be impaired. Under these preferred acetyl groups are avoided as much as possible. conditions, more than one half hour is rarely The exact temperature of distillation, at a given required for substantially complete rearrange 30 preSSure, varies With the particular fat used in ment of acyl groups, although longer periods are the rearrangement and With the speed of dis not harmful. Furthermore, while a substantiai tillation which is desired. Thus in the case of degree of rearrangement should be effected, it unhydrogenated cottonseed oil, distillation has is not imperative that the reaction go to final been practiced at about 205 to 250° C. at a pres completion. Sure of about 2 mm. Imercury, while in the case The rearranged mixture is of complex conm of unhydrogenated rapeseed oil, temperatures stitution, the relative proportions of the con of about 220' to 270° C. have been required. One stituents depending upon the proportions of skilled in the art is of course guided by the shape triacetin and of fat initially used. It Will con of the distillation curve (temperature vs. amount prise triacetin, high molecular triglycerides, O distilled) in deciding which distilled fractions to monoacyl diacetins and diacyl noinoacetins, and Collect. each of these except triacetin is capable of varia The residue after distilling of the diacetyl tri tion, depending on the particular glyceryl carbon glycerides is largely a mixture of monoacetyl tri atoms to which the various acyl groups are at glycerides and of unreacted high molecular tri tached. For rearrangement to a diacetyl tri glycerides, and this mixture may if desired be glyceride, which is the objective in my process, reWorked in my process. two moles of triacetin are theoretically required The distilled fraction consisting predominantly per mole of high molecular triglyceride. In prac of diacetyl triglycerides is collected separately. tice, the optimum proportion may differ widely It is difficult to determine with certainty its from this theoretical figure and Will of course molecular composition and structure, for ex vary from time to time as market costs of triace ample the relative proportions of diacetyl tri tin and fat vary. In general, for combined cost glycerides which exist in the symmetrical and in economy and high yield of diacetyl triglycerides, the unsymmetrical form. However, the rear I usually prefer to employ the triacetin and high rangement is purely random and is governed by molecular triglyceride in a molar ratio of about the laws of chance, so that about two thirds 0.75:1 to about 3:1. 5 5 of the diacetyl triglycerides are 1-acyl-2,3-diace Rearrangement is next discontinued and its tin and about one third is 2-acyl-1,3-diacetin. resumption in subsequent steps prevented. This If the distillation cuts are not sharp, minor may be accomplished by removing the catalyst amounts of monoacetyl triglycerides and perhaps as for example by Washing with Water, or by 60 traces of triacetin and of acetyl-free triglycer inactivating it as for example by treating it. With ides may also be present; thus commonly from enough acid to react fully therewith. Phosphoric about one third to about one half by weight of and acetic acids, because of their high Solubility the product consists of monacetyl triglycerides in fats, are especially suitable for this purpose. and Symmetrical diacetyl triglycerides, although After acidification, water-soluble Salts and free the product is predominantly unsymmetrical acid may be removed by Water-Washing, or if 65 diacetyl triglycerides. desired any free acid may first be neutralized On cooling, the fraction which consists pre With alkali. In some cases, an alkali refining dominantly of unsymmetrical diacetyl triglyc step is introduced after acidifying the rearranged erides Crystallizes into a waxy form which is fat mixture. Such procedures involve separation 70 plastic, yielding, pliable, impressionable, non of aqueous layers, in which the greatei' part of brittle, non-friable, to a limited degree elastic, any unreacted triacetin is dissolved and removed, capable of being cut, scratched or deformed In order to obtain mixtures containing high Without fracturing, but lacking in stickiness or molecular diacetyl triglycerides suitable for cook tackiness, these being properties referred to ing purposes and of Such composition as to 75 herein by the term “waxy.' This waxy form 2,815,160 5 6 is also characterized by its translucency. In storage conditions begins to convert from the thin layers of only 1 or 2 millimeters it appears waxy translucent form into a non-waxy opaque wholly clear and transparent; in thicker layers form in a matter of 3 to 4 weeks. X-ray exam (5-10 mm. for example) it transmits a large ination of this cottonseed oil product will be proportion of incident light, although Some of discussed in a later paragraph. this transmitted light is diffused So that objects Eacd.imple 2-100 parts of refined and bleached viewed through the fat layer suffer blurring soybean oil were hydrogenated to practical icon of Outline. In bulk, the fathas a colorless, WaX pletion. The dried fat was then melted and like appearance. Furthermore, the products of mixed with 35 parts of dry triacetin and the this process are commonly less greasy and melt 10 acyl groups of the mixture Were molecularly re over a narrower range of temperature than do arranged under the catalytic influence of 0.5 Conventional fatS. part of sodium methylate as in Example 1. The Another outstanding and distinguishing char catalyst was inactivated With acetic acid and acteristic of the products of my invention is the acidified mixture was alkali-refined With their great stability in the Waxy translucent forral 5 14 Bé. lye. Residual unreacted triacetin was when held at temperatures slightly below their removed by steam distilling as in Example 1. melting point. The pure unsymmetrical diacetyl The mixture remaining had a complete melting triglycerides described by Jackson have only a point of 52.7° C. Diacetyl triglycerides Were limited lifetime in Waxy translucent form; on next steam distilled at 210-230°.C. under; abolt .2 standing at temperatures slightly below their 20 mm. of mercury. the yield of distillate Was 3.1% melting point for a matter of a few Weeks they by Weight of the original mixture of oil and tri begin to convert into the opaque Solid form of acetin. conventional fat. In contrast, the mixtures of On cooling, the distillate Solidified to a Waxy diacetyl triglycerides which constitute my prod translucent non-greasy form having a COn ucts have greatly improved stability as Will be paratively sharp melting point between 32:0 more specifically shown hereinafter; for ex and 32.8° C. It was stored for one year at ample, the product of Example i below showed room temperature without any apparent change no evidence of losing waxiness or translucency in Waxiness or translucency. X-ray examina even after storage for 20 months at room tem tion of this product will be discussed in a later perature. paragraph. The following examples, in Which all partS Eacample 3.-Refined and bleached coconut oil are by weight, illustrate ways in which I practice Was mixed with half its weight of dry triacetin the invention, but it will be understood that these and the mixture was molecularly rearranged examples are illustrative only and that the in as in Example 1. After inactivating the catalyst vention is not limited by the details thereof 35 by acidification and water-washing, remaining but only by the appended claims. triacetin was removed by steam distillation at Eacample 1-100 parts of refined, bleached and 2 mm. mercury, leaving a product With a Saponi dried cottonseed oil were mixed at roon ten fication value of 376. By more drastic steam dis perature with 50 parts of dry triacetin and with tillation a second fraction, amounting to 40% by 0.3 part of sodium methylate catalyst Suspended by Weight of the original coconut oil and tri in xylene. Random rearrangement of acyl radi acetin, was isolated. This fraction Was then cals was allowed to proceed in the mixture for hydrogenated to an iodine value of 0.1. Its One-half hour, after which time an exceSS Of saponification value was 459.7, to be compared glacial acetic acid was mixed therein in order with a calculated value of 458 for the diacetin to inactivate the catalyst. The acidified mix triglyceride of hydrogenated . coconut oil fatty ture was Water-washed until free from acid, the 2Cids. greater part of the unreacted triacetin, also be By cooling this product to about -20. C., a ing thereby removed. It was then steam dis Waxy translucent solid was obtained which tilled under a pressure of 2 to 3 mm. of nercury, melted over the range from about -19 C. to low-boiling constituents including any remain about 2°C. It was stored for 3 months at about ing unreacted triacetin being thereby removed. -18°C. to -20° C. without any apparent change The temperature of distillation Was then raised in waxiness or translucency. X-ray : examina to 205-250° C. in order to remove high molecular tion of the product will be discussed in a later diacetyl triglycerides. This distillate was col paragraph. lected separately and amounted to 32% by Eacample 4-100 parts of refined, bleached and weight of the original mixture of cottonseed 55 dried rapeseed oil (saponification value 176.9; oil and triacetin. The saponification and iodine iodine value 105.3) was mixed with 35 parts-of values of the distillate were 381.0 and 65.5 re dry triacetin and subjected to molecular rear spectively, which may be compared with calcul rangement at room temperature with 0.3 part of lated values of 382.5 and 57.7 respectively for sodium methylate catalyst in xylene. After 1 mono-oleyl diacetin. The distillate, which thus 80 hour, glacial acetic acid was added to destroy appears to be essentially monoacyl diacetin, the catalyst, and the excess acid Was removed by was next hydrogenated to an iodine value of 0.8. Water Washing. Unreacted triacetin and other On cooling to about 20° C., the product Solidi low-boiling constituents were removed by Stean fied to a waxy translucent form having a corn distillation at 2-3 mm. mercury. The resulting paratively sharp melting point, incipient at 65 29.4° C. and complete at 31.3°C., and a Saponi triacetin-free rearranged oil had a Saponification fication value of 375. In comparison, the Waxy value of 272.1, an iodine value of 86.8, incipient translucent form of unsymmetrical stearyl di melting point -25 C., and complete ... melting acetin melts sharply at 34.1° C. and has a Saponi point -5°C. fication value of 381. The product of Example 1 70 Distillation was continued, raising the tempera has been held for 20 months at room tempera. ture to 220 to 270° C. in order to separate diacetyl ture (about 25°-30° C.) without perceptible triglycerides from monoacetyl triglycerides and change in waxiness or translucency and I believe from Original unreacted oil. The yield of di it to be permanently stable under these condi acetyl triglycerides was 31%, based upon the orig tions, whereas 1-stearyl-2,3-diacetin under like 5 inal oil-triacetin Weight. The Saponification 2,615,160 7 8 value was 368.6 and iodine value was 71.2, as is found that they are too hard for satisfactory compared with calculated values at 364 and 72 use. My compounds have a great advantage respectively for the diacetyl compounds. The here, for they may be completely hydrogenated complete melting point was -7.5 C. and So rendered eSSentially immune to oxidation This material was next hydrogenated to an and rancidity, and they yet retain desirable Wax iodine value of 3.0 On cooling the melt a Waxy, like Softness. translucent Solid was obtained melting incipiently It will readily be seen that compounds which at 31 and completely at 38.3 C. It was stored When fresh possess the Waxy translucent charac for 7 months at room temperature Without any teristics of my products but which with the pas apparent change in WaxineSS or translucency. O sage of time lose them will have only limited use X-ray examination of the product will be dis fulness, the breadth of their utility being less CuSSed in a later paragraph. the shorter their lifetime in the waxy form. In The solidified products of my invention, in this respect the compounds of my invention show cluding the Specific products of Examples 1 to 4, marked Superiority over pure individual high are in marked contrast to conventional high no 5 molecular unsymmetrical diacetyl triglycerides, lecular fats. The complex mixtures of mixed tri Which latter compounds, upon storage at tem glycerides which constitute animal and vegetable peratures near their melting point, begin within oils and fats of nature (herein generically re a few Weeks to convert visibly into the conven ferred to as 'fatts') as well as their hydrogena tional opaque form commonly assumed by solid tion products commonly undergo gradual Solidi 20 fats. fication on cooling and aSSume the Soft, greasy, It Will aid in underStanding the invention to largely opaque form to Which We are accustomed. discuss the polymorphism of conventional fats, The rigidity of these so-called "Solid' fats is of Jackson's Synthetic fats and of the synthetic Commonly due to an interlocking network of fats of this invention. It is well known that con Crystals; their softness and greasiness and their 2 5 Ventional fats assume various polymorphic forms transmission of a small annount of light is due When they Solidify. The less stable forms are to their content of liquid oil which remains en capable of transforming, without melting, into meshed between the crystals. Only on further raore stable forms, the transformation being in cooling does the material become wholly Solid and fluenced by the temporal and thernal history of liquid-free, and when this is the case it becomes the material. i.he lowest melting form has com opaque, hard, brittle and non-greasy. The nonly been called “alpha' and the highest melt presence in animal and vegetable fats of such a ing form, "beta,' the former being unstable, the variety of mixed triglycerides, having a wide latter being stable. An intermediate unstable range of melting points, results in gradual soft form known as “beta prime' also frequently ening and gradual increase in greasiness When existS. In none of their polymorphic forms do such wholly solid fats are warmed. Conventional fats have the waxy translucent The breadth of their melting range and the pi'operties possessed by the solid triglycerides of consequent Softness and greasiness of conven my invention. tional fats are objectionable for a number of The polymorphic forms of a given fat may in applications, while for other uses the hardness '. Some cases be distinguished from one another and brittleness at the lower temperatures are ob by macroscopic or microscopic examination, by jectionable. My products, on the other hand, their melting points or by their dilatometric be are especially suitable for many uses by virtue of havior, but X-ray diffraction affords in general their waxy Softness, even at temperatures at the most accurate means of identification. For which they are wholly solid and liquid-free, and example, the alpha form of fats is characterized because of their narrow melting point range they by a strong Short-spacing line at about 4.1 to become greasy on warming only when their com 4.2 A., accompanying which a very weak line at plete melting point is approached. They are about 2.35 to 2.45 A. can be detected. The alpha, free from objectionable color, odor or flavor, and form of conventional fats crystallizes when the as judged by growth response and by fat utiliza fat is chilled rapidly to a temperature below the tion and digestion in nutritional studies with test 50 melting point of that form; this alpha form is animals they are nutritionally similar to con unstable, converting without melting into a ventional edible fats, hence they are especially higher-melting form, slowly on standing and Suitable for edible purposes. When chewed in more rapidly when heated nearly to its melting the mouth they are Somewhat like a gun, and point. Having once transformed into a higher their final melting is accompanied by a cooling melting form, fats cannot again transform into sensation. Those which melt above room tem the lower-melting alpha form without first pass perature but below body temperature are especial ing through the molten condition. ly Suitable for use in candy, as chocolate coatings, The individual high molecular unsymmetrical in icings and frostings, as Spray oils for crackers, diacetyl triglycerides also crystallize in the alpha, as edible "beeswax' in synthetic honey, as an 60 form when cooled slightly below (e.g. 1 or 2. C. edible chewing gun base, as protective coatings below) the melting point of the alpha form, and for products such as fruits, cheese, preserves, in that form they have the waxy translucency frozen meats and the like in order to keep out Which is characteristic of the products of my in oxygen, moisture, etc. They may be used in Vention. The Waxy translucent alpha, form of shortenings, margarins, confections, etc. They 65 these unsymmetrical diacetyl triglycerides is far are suitable for inedible uses also, as for example more stable than the alpha form of conventional in hair dressing compounds, as vaginal supposi fats, but when held for long periods of time at tories, as carrier for medicinals, and for a variety a temperature below but near its melting point of related uses. 70 it converts into the higher melting form (beta) Many Conventional fats contain Such large in which it has the properties of conventional proportions of highly unsaturated triglycerides Opatue fatS. that they Oxidize and become rancid readily, yet If, however, the alpha form of individual high When the unsaturation is decreased (as by hydro inolecular unsymmetrical diacetyl triglycerides be genation) Sufficiently to remedy this trouble, it 75 cooled to and held at a temperature considerably

2,615,160 9 O below (e.g. of the order of 20° C. below) its melt Oil.-The distilled fraction rich in diacetyl tri ing point, it undergoes a change, normally within glycerides was completely hydrogenated and 5 or 10 minutes time, which does not affect its cooled to about 20° C. The resulting waxy trans waxy translucent character, but which is evi lucent Solid was in the alpha-3 form as shown by denced by the disappearance of the Weak X-ray a strong short-spacing line at 4.09 A., a weak one Short-spacing line at about 2.4.A. and its replace at 2.42 A., and a long spacing line at 35.3. (The ment by a moderately strong line at about 3.7A., long-spacing calculated for triple-chain-length accompanied by other weaker lines. This poly. stearyldiacetin by the method of Lutton, Jour. morphic form, referred to as 'subalpha,' is in reversible Solid-to-Solid equilibrium With the O Am. Chem. Soc. 70,248 (1948), is 35.9A.) alpha, form at a transition temperature, and is On cooling to below 0° C. this product trans stable at temperatures below this transition ten formed into Waxy translucent subalpha-3, as perature. shown by a strong short-spacing line at 4.13 A., a X-ray diffraction of Solid fats also gives rise medium strong line at 3.66 A., and a long spacing to long-spacing lines which are informative as of 35.3 A. to the length of the structural units making up Product of Eacample 2, derived from hydro the crystals. This length is essentially a func genated Soybean. Oil-On cooling to slightly be tion of the acyl radicals composing a unit struc low 32 C., the fraction rich in diacetyl tri ture, since the contribution of the glycery radi glycerides Solidified in the Waxy translucent Cal to the length is small. If the length of the 20 alpha-3 form as shown by a strong short-spacing Structural unit is double the length of the acyl at 4.11 A., a very weak one at 2.35 A., and a long radical, it is Said to have a double-chain-length spacing of 37.2 A. When cooled to below 0°C., Structure, designated as “alpha-2,' 'beta-2,' the waxy translucent material had a strong short etc. This is the prevailing form among most spacing at 4.10 A., a medium strong line at 3.66 A., conventional fats whether alpha, beta, or beta, 22. 5 and a long-spacing of 37.2 A., indicating the sub prime, unless indeed there is a large difference in length between the different acyl chains pres alpha-3 form. ent in the molecule. On the other hand, if the Product of Eacample 3, derived from coconut length is thrice the length of the acyl radical, Oil.-The distilled fraction rich in diacetyl tri the structure is said to be triple-chain-length 3 O glycerides WaS completely hydrogenated and (designated as “alpha-3,' etc.), and this is the cooled to about -20° C., when it solidified in case with individual high inolecular unsymmetri Waxy translucent form. This forni was shown cal diacetyl triglycerides. The relationship be to be Subalpha, by a strong short-spacing line at tWeen long Spacings and structure is discussed by 4.13 A. and a medium strong line at 3.74 A. Long Eutton, Jour. Am. Chem. Soc., 70, 248 (1948). 3 3 Spacing lines were found at 37.5 A. and 28.5 A., The polymorphism of my products is in some Which correspond roughly with triple chain respects similar to that just described for the lengths of 35.9A. and 28.4 A. calculated respec individual high molecular unsymmetrical diacetyl tively for Stearyldiacetin and lauryldiacetiri. This triglycerides and in other respects dissimilar. product could not be crystallized in the alpha, My products, when cooled below their melting 40 form. point, Solidify in the waxy translucent alpha-3 Product of Eacample 4, derived from rapeseed forn, or in Some cases directly in the Waxy trans Oii.-The distilled fraction rich in diacetyl tri lucent subalpha-3 form without passing through glycerides was hydrogenated to substantial comi the alpha-3 form. Those which solidify first in pletion and was cooled to slightly below 31° C. the alpha-3 form are transformed into Sub The resulting waxy translucent solid showed the alpha-3 by Sufficient cooling, and again convert 45 strong short-spacing at 4.08A. which is character into alpha-3 upon re-Warming, melting finally istic of alpha forms of fat. It had a long spac taking place from the alpha-3 form. Those ing of 36.9A. It was therefore concluded that it Which Solidify directly in the Subalpha-3 fornia was in the alpha-3 form. cannot be converted into alpha, i.e. upon warm The length of the high molecular acyl chains ing they melt without previous change of phase. and the degree of unsaturation in my product Illustrative X-ray data on the products of affect its melting point and whether it crystal Examples 1 to 4 are given below. The diffraction lizes in the subalpha-3 form only or in both al patterns were obtained by the general technique pha-3 and Subalpha-3. In general, long chain described in George L. Clark’s “Applied X-rays,' is and Saturation go with high melting point and third (1940) edition, chapter XIII. A beam of capacity to exist in both alpha-3 and subalpha-3 X-rays from a copper target in a vacuum tube form, While short chain and unsaturation go with Operating at 40-45 kilovolts (peak on rectified low nelting point and capacity to exist in sub current) and 20 milliamperes was collimated by alpha-3 form only. By varying the chain length In eans of a pinhole system in order to render and the degree of unsaturation, I am thus able the rays essentially parallel. These rays were 60 to obtain waxy translucent products having any then passed through a thin layer of the triglyc desired melting point. While products melting eride Sample in a thin-walled glass capillary, between body temperature and the normal room and the resulting diffracted rays were recorded on temperature of temperate zones have particularly a flat photographic plate located at a measured 65 Wide variety of uses, it will be perceived that prod distance of either 5 or 10 centimeters beyond the uctS which are liquid at such temperatures may Sample. The duration of exposure of the plates yet be of high utility as waxy translucent solids Was about one hour in the former case and about at low temperatures, Such for example as in cold 4 hours in the latter. Between sample and plate storage, in winter weather or in northern lati a lickel foil was placed in order to filter out the tudes. On the other hand, products of very high Copper K-beta wave lengths. The short and 70 Irielting point may have especial applicability to long spacings were calculated in conventional use in tropical regions or under similar high manner from the resulting diffraction rings, using temperature conditions. Bragg's law. Products which contain wide variation in high Product of Eacample 1, derived from cotton Seed is molecular acyl groups with respect to either chain

- - 2,615,160 11 12 length or Saturation or both, met over a wide triglycerides have limited waxy translucent sta range of temperatures. It will be seen that in bility, the corresponding symmetrical diacetyl Such cases, where melting of Sone of the con triglycerides have even poorer stability, and yet stituents occurs while other constituents remain that on mixing these isomeric forms products are Solid, the products will lose their waxiness and obtained which are more stable in the waxy become greasy within this temperature range, translucent form than either of the isomers thus leaking liquid oil before melting is complete. alone. This behavior is illustrated in Table 1 In order partially to avoid this condition, which in Which the visual appearance of samples after is Seldon desirable, I frequently prefer to have storing at about 25° C. is recorded, this being a only saturated products. This can be accom O temperature at Which all of the samples crystal plished by using fully Saturated fats to begin with, lize in waxy translucent alpha-3 form. Such for example as tristearin or tripalinitin or completely hydrogenated animal or vegetable Table 1 fats. However, instead of hydrogenating animal or vegetable fats before molecularly rearranging 5 Days before Percent Percent appreciable them with triacetin, I may introduce a hydro ASA SAA2 conversion to genation step at any other stage in the process of opaque form preparing my products. Thus Imay hydrogenate the molecularly rearranged mixture before dis 100 O 1. 80 20 43 tilling off unreacted triacetin, or after distilling 20 70 30 98 off unreacted triacetin but before distilling the 60 40 3 >120 diacetyl triglyceride fraction, or the distilled di 40 60 3>120 acetyl triglyceride fraction only may be hydro 20 80 66 genated. O 00 20 This saturation of ethylenic double bonds by 25 ASA as symmetrical stearyldiacetin. hydrogenation serves another purpose also, in SAA = unsymmetrical stearyldiacetin. that it reduces the Susceptibility of the product 8 Observation terminated after 120 days. to oxidation and rancidity. Thus my saturated products have the combined properties of low I have further found that while 1-stearyl-2,3- oxidation susceptibility and of softness even at : diacetin and 1-palmityl-2,3-diacetin, each taken low temperature. In contrast, softness at low alone, have limited stability in the waxy trans temperatures is commonly associated with oils of lucent form, yet mixtures of these have vastly high iodine value and consequent Susceptibility increased Stability in that form. This is illus to oxidation, while slight susceptibility to oxida trated in Table 2, wherein the visual appearance tion is customarily found only in oils of low iodine 3. 5 of Samples is recorded after storing at 21° C. for value and consequent great hardness and high six months, this being a temperature at which melting point. all of the Samples crystallize in waxy translucent In order that the synthetic fat of my inven alpha-3 form. tion exist, depending upon temperature, in both Table 2 the waxy translucent alpha-3 and Subalpha-3 40 polymorphic forms, it is in general needful that Percent, Percent 50 per cent or more by weight of the combined SAA1 PAA Appearance high molecular fatty acids be Saturated and Con - - tain at least 16 carbon atoms. With more than 100 0 Opaque. 75 25 Waxy and translu about 50 per cent of combined unsaturated fatty cent. acids and fatty acids of less than 16 carbon atoms, 50 50 Do. there are indications that only the Subalpha-3 25 75 Do. form exists. From a practical viewpoint it is of O 00 Opaque. little importance whether the products are al pha-3 or subalpha-3, since most physical prop SAA =l-stealyldiacetin, alpha-3 melting point 34.1° C. erties are essentially the same in both cases. For PAA = 1-palmityldiacetin, alpha-3 melting point 22.4°C. example, a pliable coating of one of my diacetyl X-ray examination of the samples of Table 2 triglyceride mixtures may exist at one tempera showed that the mixtures were entirely in the ture in one of these forms and at another tem alpha form when the experiments were termi perature in the other form, and yet appear the nated at the end of six months, whereas during same and perform its function equally well in the first month's storage SAA underwent a 40%, both. Conversion into beta form and PAA underwent a Especially useful properties are possessed by 5 to 10% conversion into a beta prime or related mixed diacetyl triglycerides derived predomi form. nantly from palmitic and stearic acids, since Such 60 Noticeably improved stability in the waxy triglycerides crystallize in Waxy translucent form translucent form is in general found in mixtures of high stability and have relatively sharp melt of high molecular diacetyl triglycerides in which ing points, and these melting points are not far at least 10% by weight of the high molecular below the temperature of the human body. They acyl groups are different from the remainder of hence melt readily in the mouth, and yet they 65 the Said acyl groups, and especially when this do not become soft or greasy or leak liquid oil percentage figure exceeds 20%. Likewise, notice until heated nearly to their melting point. ably improved stability in the waxy translucent While I have determined the fact that mixed form is in general found in mixtures of high symmetrical and unsymmetrical diacetyl trigly molecular Symmetrical and unsymmetrical di cerides which I have described are greatly Su 70 acetyl triglycerides in which at least 10% by perior to individual unsymmetrical diacetyl tri Weight of Said triglycerides differ from the re glycerides in stability in waxy translucent form, maining triglycerides in structure or composition I have not been able to determine the cause for Or both, and especially when this percentage their improved stability. I have found, however, figure exceeds 20%. that although individual unsymmetrical diacetyl 75 Structurally, my invention covers mixtures 2,615,160 ) 13 4 containing (a) from 10% to 90% by weight of excess of these non-glyceride esters which re mains in the reaction mixture may be readily triglycerides of the formula Separated therefrom by fractional distillation or R Co.. O (H, otherwise. In the case of non-glyceride acetic CEC o ogh esters, there is the further limitation that these be esters of alcohols which, when reesterified with CH3CO. OCH, the high molecular fatty acids in question form and inversely from 90% to 10% by weight of therewith esters which differ substantially in boil triglycerides of the formula ing point from the diacetyl triglycerides. Thus RC orch, 0. if non-glyceride esters are present in the rear rangement reaction mixture, they should be only Chico-CE those which have boiling points enough higher CHCO.0 CE, than or enough lower than the diacetyl triglyc wherein RCO represents acyl radicals of the erides to permit Separation therefron by frac group consisting of either saturated or unsatu 5 tional distillation. rated high molecular fatty acids and R'CO Interesterification processes whereby high mo represents any other acyl radicals from the Saline lecular diacetyl triglycerides are formed are also group, (b) corresponding mixtures containing the practicable, using incomplete or partial esters. Symmetrica isoners of the above compounds, For example, coconut oil monoglyceride or di and (c) mixtures containing from 10% to 90% 20 glyceride or mixtures thereof can be catalytically by Weight of triglycerides of the formula, rearranged With triacetin to give a mixture com Chico-op H, prising diacetyl triglycerides of coconut oil fatty RCO. O. CH acids, and conversely, coconut oil can be rear ranged. With mono- or diacetin or mixtures there CH co-och, 25 of to give like products. and inversely from 90% to 10% by weight of tri Interesterification acetylations lead to mixtures glycerides of the formula, comprising diacetyl triglyceride isomers, whether the original esters consisted of mixtures of Rco-op H, isoners or Whether only one isomeric form was Chico-ogi. 30 Originally present. CH3CO. O CH2 Non-interesterification acetylations of high Wherein. RCC- has the same neaning as above, molecular monoglycerides are practicable where whether these acyl radicals be the same or in the nonoglycerides, either melted or dissolved different. in a Solvent, are for example heated with acetic Complete thermodynamic stability in Waxy anhydride in the presence of sodium acetate, or translucent format, temperatures below the melt with acetic acid in the presence of a desiccating ing point appears to be poSSessed by fatty mix agent and a catalyst, Or with acetyl chloride in tures, which consist essentially of high molecular the presence of sodium carbonate, pyridine or diacetyl triglycerides from A to 2% by weight other tertiary amine as an acid acceptor, or by whereof being unsymmetrical diacetyl triglycer 40 Other means. Such acetylations result in mixed ides, the high molecular acyl groups of which are isoners (such as 1-Stearyl-2,3-diacetin and 2 those of substantially saturated fatty acids of 16 Stearyl-1,3-diacetin) when the original mono to 22 carbon atoms, at least 6 by weight of these glycerides Were likewise mixed isomers. Mono high molecular acyl groups differing from the glycerides may be selected, however, which are of remainder of said groups and at least /3 of Said Only One is Omeric form but which are derived triglycerides being isomers of the remaining por from a plurality of high molecular fatty acids, in tion of Said triglycerides. An example of Such a which case the acetylated product will comprise fatty mixture is a mixture of diacetyl triglycerides a mixture of diacetyl triglycerides of only one in which the non-acetyl acyls are palmityl and isoneric form, such as a mixture of 1-stearyl-2,3- steary in equimolar amounts and in which 4 of diacetin and 1-palmityl-2,3-diacetin. More com the diacetyl triglycerides are symmetrical and 2% In Only the monoglycerides comprise both mixed of then are unsymmetrical. isoners and mixed fatty acids, so that the di Mixtures of high molecular diacetyl triglycer acetyl triglycerides obtained are highly complex ides which upon cooling solidify in waxy trans mixtures, various individuals of which vary from lucent form of improved Stability may be pre 5 One another both isomerically and with respect pared in a variety of ways. One of these ways to the high molecular acyl group. involves interesterification or random molecular it is obvious that the individual monoglycerides rearrangement of esters, in which process there may be acetylated separately and the acetylated is interchange of acyl groups between acetic. esters products be thereafter mixed with one another, and esters of high molecular fatty acids. Molecur 60 and that the individual monoglycerides may be lar rearrangensent of triacetin and conventional isoneric esters of the same fatty acid or one fats has been described hereinbefore. It is ob isomeric form of esters of a plurality of fatty vious that instead of using triacetin in this proc acids. ess, other non-glyceride esters of acetic acid may The monoglycerides to which reference has be used as acetylating agentS, Such for example as 65 been made may be prepared in various ways. A ninethyl acetate. Conversely, instead of triglyc convenient method is to rearrange molecularly a erides of high molecular fatty acids, other non mixture of glycerin and a fatty acid ester, such glyceride esters of these fatty acids, such for ex for example as an edible fat triglyceride or di ample as methyl palmitate, may be interesteri glyceride (or alternatively the fatty acids them fied with (i. e. acetylated by) triacetin. In using 70 Selves), in randon manner under the influence esters (whether of acetic acid or of high molecu of a low-teaperature rearrangement catalyst. lar fatty acids) of alcohols. Other than glycerin, Conditions may be substantially those described those should be selected which have boiling points in Example 1. See article by Feuge and Bailey which differ substantially from those of the high in "Oil and Soap,” vol. 23, page 359, for an expo. molecular diacetyltriglycerides, in order that any 75 sition of the relationship between initial and final 2,615,160 15 16 proportions of constituents in random rearrange triglycerides and in waxy translucent form of Inent of glycerin-fat mixtures. great stability. The resulting rearranged mixture comprises 3. A mixture of high molecular diacetyl tri rearranged triglycerides, free glycerin, and mono glycerides in which at least 10 per cent by Weight and diglycerides, and can be acetylated in any of the combined high molecular acyl groups differ conventional manner. The acetylated mixture from the remainder of the combined high molec will thus comprise rearranged high molecular tri ular acyl groups, the said mixture being substan glycerides, triacetin (from glycerin), diacetyl tri tially free from triacetin and acetyl-free tri glycerides (from monoglycerides), monoacetyl glycerides and in waxy translucent form of great triglycerides (from diglycerides), and commonly O stability. acetic acid as well (from excess acetylating 4. A triglyceride mixture consisting predomi agent). Low boiling impurities, i. e. those boil Inantly of unsymmetrical diacetyl triglycerides ing below diacetyl triglycerides, such as acetic containing high molecular combined fatty acids, acid and triacetin, are first renoved, as previously at least one-third by Weight of said mixture con described, by steam distillation or otherwise. A 5 sisting of other triglycerides containing both fraction consisting predominantly of mixed iso acetyl and high molecular fatty acid groups, the ners of diacetyl triglycerides is next distilled, the Said mixture being Substantially free of triacetin distillation being discontinued before substantial and of triglycerides solely of high molecular fatty amounts of high boiling components, such as acids, and being in a waxy, translucent poly monoacetyl triglycerides and non-acetyl triglyc 20 morphic form of great stability. erides, are distilled. The resulting fraction may 5. The triglyceride mixture of claim 4 predomi then be chilled to form a waxy translucent solid. nantly in a waxy translucent, subalpha-3 poly It will be understood, however, that my invention morphic form. also contemplates separations by means other 6. A fatty mixture consisting predominantly than distillation, as for example crystallization of high molecular 1-acyl-2,3-diacetyl triglycer processes or fractional separations by solvents, ides at least one-half of the high molecular acyl and my invention is thus not restricted to any groups of which are those of saturated fatty acids one physical means of separating and isolating of at least 16 carbon atoms and at least one the diacetyl triglycerides. third of Said mixture consisting of other tri When I use the term “acetylating' herein and 30 glycerides containing both acetyl and high molec in the appended claims I mean thereby any proc ular fatty acyl groups, the said mixture being ess which introduces acetyl groups into a chemi Substantially free of triacetin and of triglycerides cal compound to form acetic acid esters, re Solely of high molecular fatty acids and being in arrangement of high molecular triglycerides With a highly stable waxy translucent alpha-3 poly 3 5 morphic form. triacetin and reaction of acetyl chloride or acetic 7. A fatty mixture consisting predominantly anhydride with monoglycerides being among the of high molecular 1-acyl-2,3-diacetyl triglycer examples of acetylation which I have given. ides the high molecular acyl groups of which In the foregoing discussion of the various Ways are those of palmitic and stearic acids, from of making the products claimed herein the Word O One-third to one-half of said fatty mixture con 'nay' is used to indicate that one has a choice sisting of other triglycerides containing both between two or more entirely practicable alter acetyl and high molecular fatty acyl groupS, Said natives; it denotes ability, not mere possibility. mixture being Substantially free of triacetin and All of the foregoing methods result in Satisfactory of triglycerides solely of high molecular fatty preparation of the novel products of the inven acids and being in a highly stable waxy trans. tion. 45 lucent Solid form which melts sharply below body Having thus described my invention, What I temperature. claim and desire to secure by Letters Patent is: 8. A fatty mixture in waxy translucent form 1. A fatty composition consisting essentially of Which is highly stable in that form at tempera diacetyl triglycerides, the non-acetyl, acyl radi tures below its melting point, and which consists cals of which are those of a fatty acid of 12 to 22 essentially of high molecular diacetyl triglycer carbon atoms, each 100 parts of the said mixture ides from one half to two thirds by weight of containing from about 10 to about 90 parts by Said triglycerides being unsymmetrical diacetyl Weight of diacetyl triglycerides selected from the triglycerides the high molecular acyl groups of group consisting of Symmetrical and unsyn which are those of substantially saturated fatty metrical diacetyl triglycerides and inversely from 5 5 acids of 16 to 22 carbon atoms, at least one fifth about 90 to about 10 parts by Weight of triglyc by Weight of these high molecular acyl groups differing from the remainder of said groupS and erides Selected from the group consisting of, at least one fifth of said triglycerides being iso (d) diacetyl triglycerides differing from the As of the remaining portion of said triglycer aforennentioned diacetyl triglycerides only in iso 60 CeS. meltic form, (b) diacetyl triglycerides differing 9. A process of preparing a waxy translucent Only in chain length of the high molecular fatty form of diacetyl triglycerides of high molecular acid acyl radical from the said aforementioned fatty acids which comprises (a) prepairing a mix diacetyl triglycerides, and (c) mixtures of (a) ture comprising a plurality of diacetyl triglycer and (b), the total mixture of triglycerides being ides of high molecular fatty acids, substantially Substantially free of triacetin and of triglycerides free of non-glyceride esters having essentially Solely of high molecular fatty acids and being in the same boiling point range as that of the said Waxy translucent form of great stability. diacetyl triglycerides; (b) isolating said diacetyl 2. A mixture of diacetyl triglycerides the non triglycerides from materials which differ Sub acetyl radicals of which are those of fatty acids 70 of 12 to 22 carbon atoms, at least 10 per cent Stantially therefrom in boiling point; and (c) by weight of the diacetyl triglycerides being dif chilling the thus purified diacetyl triglycerides ferent isonerically from the remainder of the to below their minimum melting point thereby diacetyl triglycerides, and the Said mixture being greatSolidifying stability. them in waxy translucent form of Substantially free from triacetin and acetyl-free 75 10. In the process of preparing high molecular 2,615,160 17 8 diacetyl triglycerides in waxy translucent form triacetin and high molecular triglycerides at a of great stability, the steps which comprise: (a) temperature below 120° C. With a catalyst which acetylating glycerides of high molecular fatty is an alkali metal alkoxide of an aliphatic monor acids to form a reaction mixture a substantial hydric alcohol having less than 5 carbon atoms proportion of which consists of a plurality of to effect molecular rearrangement of acyl diacetyl triglycerides of high molecular fatty groups in Said mixture, the molar ratio of tri acids; (b) isolating from the reaction mixture acetin; high molecular triglycerides being from a fraction which consists predominantly of a about 0.75:1 to about 3:1; acidifying the reac mixture of said diacetyl triglycerides; and (c) tion, mixture to inactivate the catalyst; remov chilling said diacetyl triglyceride fraction to 0 ing acidic material and unreacted triacetin from Solidify it in Waxy translucent form. the mixture; isolating a fraction consisting pre ll. In the process of preparing high molecular dominantly of unsymmetrical diacetyl triglycer diacetyl triglycerides in waxy translucent form ides and being substantially free of triglycerides of great stability, the steps which comprise containing less than two acetyl groups; and acetylating a mixture of monoglycerides of high 5 chilling said diacetyl triglycerides to below their molecular fatty acids to form a reaction mix minimum melting point thereby solidifying then ture which contains a substantial proportion of in waxy translucent form of great stability. a plurality of diacetyl triglycerides of said fatty 18. In the process of preparing high molecular acids, isolating said diacetyl triglycerides and diacetyl triglycerides in waxy translucent form, chilling them to Solidify them in waxy trans 20 the Steps which comprise contacting a liquid lucent form. mixture of triacetin and high molecular triglyc 12. In the process of prepairing high molecular erides With a low-temperature rearrangement diacetyl triglycerides in Waxy translucent form, Catalyst to effect a substantial degree of molec the steps which comprise acetylating a mixture ular rearrangement of acyl groups thereira; comprising glycerol and mixed monoglycerides acidifying the mixture to check the rearrange of high molecular fatty acids, thereby to form ment reaction; Steam distilling the mixture un a mixture comprising triacetin and triglycer der reduced pressure to remove therefron mate ides Which contain in their molecular structure rials of boiling point lower than diacetyl triglyc both acetyl and high molecular fatty acyl erides of high molecular fatty acids; steam dis groups; removing triacetin from the product; 30 tilling the residue under more drastic condi and isolating a fraction consisting predomi tions to remove a fraction consisting predomi nantly of mixed symmetrical and unSynnetri nantly of diacetyl triglycerides of high molecu cal diacetyl triglycerides and being substantially lar fatty acids; terminating the distillation be free of triglycerides containing less than two fore substantial amounts of material of higher acetyl groups; and chilling said diacetyl tri boiling point than the said diacetyl triglycerides glycerides to below their minimum melting distill; and chilling the fraction consisting pre point thereby solidifying them in waxy trans dominantly of diacetyl triglycerides to below its lucent form of great stability. mininnum melting point to solidify it in waxy 13. In the process of preparing high molecular translucent form. diacetyl triglycerides in waxy translucent form, 19. In the process of preparing saturated high the steps which comprise contacting a liquid molecular diacetyl triglycerides in waxy trans mixture of triacetin and high molecular triglyc lucent form, the steps which comprise contact erides with a rearrangement catalyst to effect ing triacetin and high molecular triglycerides molecular rearrangement of acyl groups there in molar proportions of about 0.75:1 to about in; discontinuing the rearrangement reaction; 3:1 with a low temperature catalyst for molec removing unreacted triacetin from the product; ular rearrangement of glycerides at a temper and isolating a fraction consisting predomi ature below 120° C. but above the melting point nantly of unsymmetrical diacetyl triglycerides of said mixture until substantial molecular re and being substantially free of triglycerides con arrangement of acyl groups therein has taken taining less than two acetyl groups; and chilling place; adding acid to the rearranged mixture said diacetyl triglycerides to below their mini 50 to inactivate the catalyst; fractionally distill mum melting point thereby solidifying them in ing the rearranged mixture under reduced pres waxy translucent form of great stability. Sure to remove unreacted triacetin therefrom; 14. The process of claim 13 wherein the high distilling from the substantially triacetin-free molecular triglycerides which are mixed with product under more drastic conditions a frac triacetin are substantially saturated fatS. tion which is predominantly unsymmetrical di 15. The process of claim 13 wherein the high acetyl triglycerides and which contains only molecular triglycerides which are mixed with minor amounts of triglycerides having less than triacetin contain unsaturated constituents and two acetyl groups, and at any stage in the proc wherein at any stage in the process substantially eSS, catalytically hydrogenating substantially all all ethylenic double bonds which are present at 60 ethylenic double bonds which are present; and that stage are saturated by catalytic hydrogena chilling said diacetyl triglycerides to below their tion. minimum melting point thereby solidifying them 16. The process of claim 13 wherein unreact in Waxy translucent form of great stability. ed triacetin is removed from the rearranged miX FREDRIC. J. BAUR. ture by fractional distillation under reduced 65 pressure subsequent to discontinuing the rear REFERENCES CTED rangement reaction, and wherein the fraction The following references are of record in the consisting predominantly of unsymmetrical di file of this patent: acetyl triglycerides is isolated by fractional dis 70 tillation under reduced pressure subsequent to UNITED STATES PATENTS removal of triacetin. Number Name Date -17. A process of preparing high molecular di 1,558,299 Schwartz. ------Oct. 20, 1925 acetyl- triglycerides in waxy translucent form 2,091,988 Hubbuch ------Sept. 7, 1937 which comprises contacting a liquid mixture of 75 2,442,532 Eckey ------June 1, 1948 --- N--