Paterated June 13, 1933 1,913,367 UNITED STATEs PATENT OFFICE TIA S. CACOTT AND wILLIAM A. Doug LAss, of PENNS GROVE, NEW JERSEY, AND HERBERT W. WALKER, OF WILMINGTON, DELAWARE, ASSIGNORS TO E. E. DO PONT OE NEORS & COMPANY., oE WILMINGTON, DELAWARE, A CORPORATION OF DEAWARE PRESERVATION of or LS, , FATTY or LS, FATTY ESTERS, FATTY ACIDS, SALTs, AND RELATED COMPOUNDS w No Drawing. Application filed December 18, 1929. Serial No. 415,04. This invention relates to the treatment of ringer in D.R.P. 308,408 discloses alkalilac auto-oxidizable substances such as oils, fats, tates as suitable stabilizers for margarine, fatty oils, fatty esters, fatty acids and salts and . Many of the compounds of fatty acids to retard deterioration and heretofore employed, however, have been 5 development of rancidification. More par open to the objection that they either dis 55 ticularly it pertains to the addition of or color the product to be preserved or form ganic compounds to such substances in compounds that have this objectionable order to accomplish these results. Specifi property. Certain compounds of the prior cally, the incorporation of diaryl or diaral art impart to the product in which they 10' kyl compounds, such as hydroxy diaryl al are incorporated a distinctive odor. Other 60 kanes into the material to be preserved is proposed preventives are actually ineffectual contemplated. or are effective only for a short time. Butter, lard, cocoanut oil and other an This invention has as an object the pres imal and vegetable fats and fatty oils, to ervation of fats, fatty oils, fatty esters, fatty 15 gether with soap, the sodium or potassium acids, fatty acid salts and the like. A fur salts of the fatty acids contained in these ther object of this invention is to insure the fats and fatty oils, tend to develop an ob retention of the original odors of these ma jectionable rancid odor and taste on ex terials for indefinite periods. Still further posure to, air under ordinary conditions. objects are to prevent or retard the auto-oxi 20 This deterioration is due to the oxidation dation of materials of this nature, to keep 70 of the fatty acid part of the or soap the materials sweet (in the sense of the odors molecule by atmospheric oxygen. The ox given off), for a long period, to maintain the ide derivatives which are first formed be original chemical and physical states for ex come decomposed or altered and produce tended periods, to prevent reaction of these 25 substances having a rancid odor and taste. substances or their constituent parts with 75 Some work has been done in the fat pres the atmosphere or its constituent parts such ervation field as shown by U.S. P. 1,542,438 as oxygen, to insure retention of the origi to Divine, wherein aniline, alpha naphthyl nal properties of these substances, without amine, para phenylene-diamine, diphenyl discoloring or imparting objectionable odors 30 amine and hexamethylenetetramine are thereto, to prevent oxygen absorption by the 80 . added to soap. In U. S. P. 1,575,529 to Boll materials to be preserved and generally man soya bean lecithin is added to edible overcome the objectionable features of the oils. Other improvements in the keeping prior art. Other objects will appear herein quality of auto-oxidizable substances are after. 35 claimed in U. S. P. 1,672,657 to Powell ac These objects are accomplished by the in 85 cording to which the condensation product vention herein disclosed which is related to of an aromatic amine and an aliphatic alde the invention of application E391706 filed hyde is added to the material to be pre September 10, 1929, by the same inventors served. The foreign patent art also dis in that it involves further work in the same 40 closes work along this line as evidenced by field. In that application the preservation 90 B. P. 181,365 to Moureu and DuFraisse who of oils, fats, etc., by the addition thereto of employ the phenols such as pyrogallol, guai diaryl compounds is disclosed and in the ex acol, and hydroquinone as stabilizers for amples set forth the aryl groups are directly auto-oxidizable substances. In B. P. 208,189 connected. It has now been found that 45 to Lever Bros. the phenols of the types preservation may also be accomplished by 95 hydroquinone, guaiacol and resorcinol are compounds containing a plurality of aryl or used to prevent deterioration of whale oil. aralkyl groups connected through or to an Rechburg, Braun and Oetermann in D. R. P. intermediary, such as, for example, an al 254,303 disclose sulfur and pyrogallol for kane, amino or oxygen . In com 50 the preservation of oils and fats. Boeh pounds of this class, those having a hydroxy, OO 2 1,918,867 ethoxy, or amino radical attached to an aryl sorbed by the soap it will be found that the . . . . group are particularly effective. treated soap absorbs oxygen at a very much According to this invention members of slower rate than an untreated sample of the the hydroxy diaryl alkane class of com same soap. An inhibition of oxidation is pounds are incorporated into the substances secured by the use of p-hydroxy diphenyl 70 to be preserved. These incorporated mate methane in the soap resulting in an improve rials act as anti-oxidants to prevent or re ment in the aging qualities of the soap, tard the decomposition and rancidification which otherwise would have shown consid and prevent combination with or absorption erable deterioration and a development of O of oxygen. The general formula of the pre rancidity. 5 : ferred compounds used is . . . . . Eacample IV HO-R-Alkyl-R'-Y Cocoanut oil treated with 0.01% di-2- naphthol methane and exposed to the air at in which R and R' are aryl or aralky nuclei room temperature remainso stable, sweet ins 5 which may be alike or different and Y is odor, and essentially, unchanged for a cont. 80 either hydrogen, hydroxy or E. The siderably longer period than untreated oil retarding agents may be incorporated in the as determined by the sense of smell and the oilample, or fat by in mixing, any suitable and at manner any time as, forfound ex Kreis test. 30 preferable as, for instance, before or during Such compounds as di-2-naphthol meth 85. . . preparation or in the natural or ordinary ane, state. By way of illustrating our invention the following selected examples are given. ; : y : : Eacample I On OO 90. One tenth of 1% of di-2-naphthol en thane was incorporated into ordinary com p : p-dihydroxy diphenylmethane, mercial lard and the sample exposed to the action of the atmosphere at room tempera 30 ture along with an untreated control sample 95 of the same lard. After 7 days the control mm'-dihyroxy triphenylmethane, sample possessed a rancid odor and aWe a BO ...... OR

positive test for rancidity with the phloro glucinol Kreis reagent. On the other hand, 35 the stabilized lard containing di-2-naph thol methane remained sweet to smell and gave no indication of rancidity by the Kreis. color reaction with phloroglucinol. For the 3 succeeding days the treatedlard remained o-hydroxy diphenylmethane, 40 stable and free from any rancid condition to 05 the extent that it was essentially unchanged after the ten day test. p-hydroxy diphenylmethane, Eacample II p-hydroxy diphenylmethane was added to 0 a sample of lard up to a concentration of 0.1% and its effect on the development of p-hydroxy diphenyl ether rancidity observed, as in Example I. While the control sample underwent deterioration with attendant rancidity after 7 days ex p:p'-diethoxy diphenylamine 15 posure as determined by odor and chemical test using the Kreis color reagent, the lard containing p-hydroxy diphenylmethane was distinctly sweet to smell and gave a negative p : p'-diamino diphenyl amine Kreis test, indicating stabilization of the 120 lard by the with protection against spoilage and the development of have been used in lard and it was found that rancidity. lard treated with these agents remained Eacample III unaltered and free from rancidification for a considerably extended period over the time 25 If 0.05% of p-hydroxy diphenylmethane required for ordinary lard containing no be incorporated in soap, for example, white anti-oxidant to become deteriorated and olive castile soap, and the soap exposed to rancid. These substances may also be used the action of atmospheric oxygen at 60° C. with the same advantages in other animal 85 in such a way as to measure the oxygen ab- fats, vegetable oils, and soap. 30 1,918,367 3 The description of the Kreis color reac The aryl groups which may be substituted tion phloroglucinol test may be found in are not limited to phenyl, naphthyl, and bi J. I. E. C. 15, 1051 (1923). Briefly it is as phenyl groups, but tolyl, xylyl, or any other follows. One tenth of a gram of fat dis aryl group may be used with effectiveness in solved in 5 cc. ether is shaken with 5 cc. con compounds of the general type. It will, of 70 centrated HCl. The mixture is then shaken course, be obvious that when the aryl groups with 5 cc. 1% ether solution of phloroglu have substituents other than hydroxy or cinol. The development of a typical red alkoxy groups that the same must be of color in the HCl is regarded as a positive such nature as not to neutralize the hydroxy 0. reaction. or alkoxy groups or nullify the inhibitive 75 It will be understood that the concentra effect of the main nucleus and furthermore tions of antioxidant agents may vary to se must be compatible with the object in view. cure protection against deterioration to a less Other members of the general class de and greater degree depending on the nature scribed in this specification which may be 5 of the fat, fatty oil or soap in question, the used effectively are listed by way of example 80 nature of the antioxidant, and the actual below: concentration of agent used. Ordinarily the sym. trip-hydroxy triphenyl methane amount of the used ranges from 0.001 to 1.% but this invention con 20 templates greater amounts if there be a 85 particular need therefor, although so far it has not been found necessary to use more than the maximum amount stated above. The listed are not harmful OB 25 so far as applicants are aware, but it is 3-benzyl-2-naphthol, 00 probably advisable to limit their use in edi ble materials to small quantities. Accord ingly the particular conditions of each case will determine the amount needed. 30 Other compositions of the type described OO.C. 95 above but which contain certain substitu 3:3'-dihydroxy diphenylmethane, tions of analogous groups in the general OH OB formula are also effective . For example, we may introduce a third aryl e group as in mm-dihydroxy triphenyl meth 2:4'-dihydroxy diphenylmethane, 00 ane, or replace the OH groups by alkoxy. grouproups as in pp'-diethoxy diphenylmethane, OB

40 ch,0-{C)-CH-O- OCEs. 4:4'-dihydroxy 2: 2'-dinaphthyl methane 05 Further, in the type formula either R or R or both may be a biphenyl nucleus thus giving a large number of compounds which are effective for the purpose mentioned. 45 Such compounds, for example, include: COOO O p-hydroxy p'-phenyl diphenylmethane, p-hydroxyphenyl-2-naphthyl methane,

50 pp'-dihydroxy di-biphenylmethane, -(D-CO 5 By the use of these retarding agents, auto hog X-(>-ch-()-(D-on oxidation of these substances is effectively p-hydroxy biphenyl-2-naphthyl methane, retarded, delayed or prevented in such a 55 way that they remain sweet and apparently 20 unchanged for considerably long periods of time. In addition to being very good inhib itors of deterioration and development of rancidity, the class of compounds disclosed 60 p-hydroxy biphenyl-2(4-hydroxynaphthyl) herein is light-stable and gives rise to sub 125 methane stantially no discoloration of white or light color fat and soap stocks. Some fats and soaps when exposed to the action of sunlight or ultra-violet light show considerable dis 30 65 OB coloration when they contain certain organic

4. 1,918,367 compounds as, for example, diphenylamine. nucleus in which at least one of the aryl This is avoided by the use of the compounds groups is oxy-substituted. herein disclosed. 8. A composition of matter including a Of the oxy-diaryl-alkanes, the E, substance of the group fats, fatty oils, fatty diaryl-alkanes are preferred. Especially esters, fatty acids, and fatty acid salts and 70. good results have been obtained with para a compound having a plurality of aryl hydroxy-diphenyl methane. groups joined to an alkane nucleus in which In this specification and claims the term at least one of the aryl groups is a phenyl “oxy-' is used generically and includes “hy radical, and in which at least one of the aryl O droxy' and “alkoxy-”. groups is oxy-substituted. 75 By the term “auto-oxidizable' is meant the 9. A composition of matter including a capacity for spontaneous chemical combina substance of the group fats, fatty oils, fatt tion with or absorption of oxygen of the esters, fatty acids, and fatty acid salts and atmosphere under ordinary conditions. in an amount less than 1%, a compound 15 As many apparently widely different em having a plurality of aryl groups joined to 80 bodiments of this invention may be made an alkane nucleusin which at least one of the without departing from the spirit and scope thereof, it is to be understood that we do ataryl least groups one is of a phenylthe aryl radical, groups and is inhydroxy which not limit ourselves to the specific embodi substituted. 20 ments thereof except as defined in the ap 10. The method of preserving a compound 85 pended claims. tending to develop rancidity which compris We claim: es the step of adding to the compound to 1. A member of the group fats, fatty oils, be preserved an oxy-diaryl alkane in an fatty esters, fatty acids and fatty acid salts amount less than 1.%. 25 together with 0.001 to 0.1% para hydroxy 11. A composition of matter including a 90 diphenyl methane as an oxidation inhibitor substance of the group oils, fats, fatty oils, and rancidification preventative. fatty esters, fatty acids, and fatty acid salts 2. In a method of retarding rancidifica and an oxy diary alkane compound. tion and inhibiting oxidation of a member 12. A composition of matter including a 30 of the group fats, fatty oils, fatty esters, substance of the group fats, fatty oils, fatty 95 fatty acids and fatty acid salts, the step of esters, fatty acids, and fatty acid salts and adding thereto 0.001 to 0.1% para hydroxy an oxydiphenyl alkane compound. diphenyl methane. 13. A composition of matter including a 3. A composition of matter including a substance of the group fats, fatty oils, fatty 35 substance of the group fats, fatty oils, fatty esters, fatty acids, and fatty acid salts and 00 esters, fatty acids, and fatty acid salts to a hydroxy diphenyl alkane compound. gether with a compound adapted to inhibit 14. A composition of matter including a rancidification, said compound having a plu substance of the group fats, fatty oils, fatty rality of aryl groups joined to a nucleus esters, fatty acids, and fatty acid salts and 40 and in which at least one of the aryl groups a compound of the type 105 has a substitution radical attached thereto. 4. A composition of matter including a HO-R-Alkyl-R'-Y substance of the group fats, fatty oils, fatty esters, fatty acids, and fatty acid salts to in which R and R are aryl or aralkyl nuclei 45 gether with a compound adapted to inhibit which may be alike or different and in which 0. rancidification, said compound having a plu Y may be hydrogen, hydroxy or alkoxy. rality of aryl groups joined to a nucleus 15. A composition of matter including a other than an amino group. substance of the group fats, fatty oils, fatty 5. A composition of matter including a esters, fatty acids, and fatty acid salts and 50 substance of the group fats, fatty oils, fatty a compound of the type esters, fatty acids, and fatty acid salts and HO-R-CH-R-Y a compound having a plurality of aryl groups joined to an alkane nucleus. in which R and R are aryl nuclei which 6. A composition of matter containing a may be alike or different and in which Y 55 compound capable of rancidification and as may be hydrogen or hydroxy. 120 an oxidation inhibitor and rancidification 16. Animal fat together with a hydroxy preventative a compound of the hydroxy diaryl alkane compound. diaryl-alkane class. alkane17. Lard compound. together with a hydroxy diaryl 30 7. A composition of matter including a 18. Vegetable fat together with a hydroxy 25 Substance of the group fats, fatty oils, fatty diaryl alkane compound. esters, fatty acids, and fatty acid salts to gether with a compound adapted to inhibit 19. Cocoanut oil together with a hydroxy rancidification, said compound having a plu diaryl alkane compound. 65 20. Soap together with a hydroxy diaryl rality of aryl groups joined to an alkane alkane compound. 30

1918,867

Y 21.is alkoxy. The composition of claim 14 in which 22. The composition of claim 14 in which Y is alkoxv and in which one of R and R' 5 is naphthyl. 23. A composition of matter comprising a member of the group consisting of fats, fatty oils, fatty esters, fatty acids and fatty acid salts and 0.001 to 0.1% para-alkoxy 20 diphenyl-methane which is substantially identical with the product resulting from incorporating a para-alkoxy-diphenyl-meth ane in a member of the aforesaid group. 24. The art of retarding rancidification of 5 a member of the group consisting of fats, fatty oils, fatty esters, E.tty acids and fatty acid salts which comprises the step of incor porating an oxy-diaryl-alkane therein. - Intestimony whereof we affix our signa 20 tures. . WILLIAM. S. CALCOTT. WLLIAM A. DOUGLASS. HEREBERT W. WALKER. 25

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