Patented Dec. 17, 1 Y 2,412,557 1 UNlTED- STATE s PATENT ornce 2,412,557 LUBRICATING OILS -. Charles M. can, Jr., Webster Groves, Mo., as» signor to Petrolite Corporation, Ltd, Wilming ton, Deb, a corporation of Delaware No Drawing. . - Original application October 16, 1944, Serial No. 558,949. Divided and this ap plicatlon April .20, 1945, Serial No. 589,463 , 8 Claims. (01. 252-515) 1 This application is a division of my pending . unsaturated primary or secondary amine, in application Serial No. 558,949, ?led October 16, . which the unsaturation is ethylenic and the eth 1944, for New chemical product and method of ' ylenic carbon atom nearest to the amino nitrogen atom is separated from said nitrogen atom by‘ manufacturing same, and relates to a new com at least four singly bonded carbon atoms. The position of matter comprising a lubricating oil nature of the reaction is not clearly understood, and a new chemical product consisting of poly and. is not readily explainable in terms of well amide. and polyamide compounds of relatively known organic reactions. However, a tentative high molecular weight. The new chemical ‘prod theory of the'reaction mechanism and of the not above referred to may be prepared by react ing an alpha-beta, unsaturated acid or anhydride' 10 structure of the products will be given below. Acidic reactants found useful in the prepara with an unsaturated amine of the'kind to be tion of the present products, are the alpha-beta, described, under conditions which cause polymer unsaturated acids and anhydrides which do not ization of the amide or imide initially formed. - The preparation of polymers of the reaction contain a vinyl group, especially those contain of multifunctional acids and multifunctional 15 ing less than 10 carbon atoms. ‘Examples of . such acids and anhydrides are crotonlc acid, amines, is an old and-well known art, exempli- maleic acid, citraconic acid, glutaconic acid, aco ?ed, for example, by the reaction between ethyl nitic acid, itaconlc acid, mesaconic acid, maleic ene diamine and adipic acid. Preferably, the anhydrida'citraconic anhydride and itaconlc an . new chemical product that forms part of my new hydride. . _‘ , 20 composition of matter, is prepared from reactants The .condensation of esters and amides of car in which polyfunctionality is not dependent on boxylic acids containing a vinyl group, such, as the presence of more than one carboxyl radical those of acrylic and methacrylic acids, is rela in the molecule,’ or more than one amino radi tively well. known and understood. The present . cal. If such plurality of carboxyl radicalsv of plurality of aminoradicals are present, it is 25 products are prepared by a reaction which ap purely, incidental. The polymers herein contem- . plated are dependent on the functionality of the unsaturated ethylene radical of the alpha-beta acid or anhydride on the one hand, and on the , polyfunctionality of the unsaturated amine on 30 the other hand, based on the presence of the amino radical, and additionally, on the function ality of the unsaturated ethylene radical which parently differs from ordinary ole?ne polymeri zation, such as is involved in’ the acrylate poly merization. Such vinyl polymers are not con templated herein. These acids may be monobasic, or polybasic, including dibasic. Because of their low cost and ‘availability in commercial quantities, maleic an hydride, fumaric acid and citraconicanhydride, are especially useful, and products obtained with may enter into reaction per se, or which may activate a hydrogen atom attached to a car 35 these reactants will be used below to illustrate‘ .the present invention. ‘ bon atom in a position alpha to, or perhaps, even ‘Suitable amines for use in preparing the new beta to the unsaturated linkage. It happens that dicarboxy, alpha-beta, ethylenic acids or their an hydrides, such as maleic anhydride, are most chemical product previously referred to are the unsaturated primary and secondary amines, in readily available,-and thus are most conveniently 40 whichthe unsaturatlon occurs in an aliphatic or cycloaliphatic residue, and in which the ethyl-' However, in combination with such enic carbon atom nearest to the amino nitrogen polyoarboxy acid compound, it is preferred that is separated from said nitrogen atom by at least the unsaturated amine contain only. one amino four singly bonded carbon atoms. Such amines radical. Monocarboxy acids may be employed, \ employed. and similarly, unsaturated polyamino compounds 45 may be aliphatic, valicyclic, mixed aliphatic-ali may be used, but such reactants are not com monly available at the present time. ' My present invention contemplates polymeric cyclic, alkylaromatic, alicyclic-aromatic, or other containing aliphatic, alicyclic and aromatic resi dues, and in which the hydrocarbon residues at tached to the amino nitrogen contain 8 or more " compounds derivable by reaction between an alpha=beta, ethylenic acid or-anhydride and an 50 and less than '32 carbon atoms.- As stated above, ‘2,412,557 ‘ing reaction, a slow stream of oxygen or oxygen suitable amines must have an _ethylenic unsat uration removed by four singly bonded carbon v , ‘containing gas, such as air. ' ‘ The bene?cial effect of this operation appears atoms from the amino nitrogen; however, in ap plying this restriction, aromatic ring carbons are . ' to arise directly from the oxygen in the gas used. If nitrogen, hydrogen, or other oxygen-free gases arepassed through the mixture, the rate of p01? merization is not. appreciably increased. Eiiorts to be considered as‘ singly. bonded. "Examples, of suitable amines include oleylamine, dioleyl - amine, phenyloleylamine, oleylaniline, p-decenyl to 11nd a catalyst comparable to oxygen have so ' cyclohexylamine,dihydroabietylamine,p-l-decen ylaniline, N-p-decenylcyclohexylaniline, etc. Such ' far failed. ‘ amines may have one or. more amino groups per ,Whenemploying oxygen or air as a catalyst, 10 " the-temperatures of reaction may vary over molecule, but the preferred reactants, because of cost, are monoamines. Where a'secondary' rather wide limits, but best results are usually'ob amine isv employed, it is necessary‘that only'one, ' tained within the range of 150° C. to 220° C. of the aliphatic or cyclcaliphatic radicals at- , With reactants that boil ‘within or below this tached ‘to the amino nitrogen be unsaturated. v15 temperature range, it is ‘desirable to carry out the ' The unsaturated amine may'contain one or more - reaction under pressure, or to conduct the reac carbon-to-carbon double bonds. The preferred '_ amines are aliphatic, cycloaliphatic and alkylcy-v tion at a lower temperature until amide or imide z formation has produced an intermediate of high cloaliphatic amines which contain 8 or more car- ' . er boiling point. I The temperature may then be to a higher value.v The use of oxygen . bon atoms and less than 32 carbonatoms' in each' 20'- increased hydrocarbon residue. attached to the amino‘ nitro ‘ ‘containing gas' as a reaction catalyst leads to gen. Examples‘of preferred vimines are: l-ami- ' ' some ‘concomitant oxidation which may take no-octene-5, l-aminode‘cene-9;"oleylamine; ,lin-j ‘ ' place ,to ‘an objectionable degree, it ‘extremely ileylamine; abietylz'amine,‘ dihydroabietylamine, 2s: high temperatures. are used.‘ - . The following examples will serve to illustrate ll erucylamine, p-IédecenyIcycIohexyIamine,"~ diole-' how chemical products-or compounds or the kind ylamine, n-hexadecyl-#noctadeeenylamine, unsat- _ above described‘ may be prepared or produced.» urated secondary amines obtained as a lay-prod. uct in the manufactureof‘primary amines from .' _ ' red oil, commercialmixtures of unsaturated-pri - mary amines derived ‘from fatty oils, etc. ' ' v_ 0mm; Pnonucr - - Example 1 ' _ I - In preparing the new chemical product that _ :54 partso'f crude octadecenylamine (iodin forms part of my ew composition of matter, the No.='78) and 20 parts of maleic anhydride were choice of the relat ye number of moles of the re ,heated and stirred in a vessel equipped with a gas actants is somewhat variable. Under suitable tube, condenser and water trap. The tem conditions, at least one mole of alpha-beta, 35. ‘inlet perature was held at 190° C. for 2 hours. A slow ethylenie acid appears to be able to combine ad ditively with an amine having one carbon-to-car- __ bon double bond, while simultaneously condens ingwith the amino group to yield amide or imide' The product at this point was a red, viscous, almost rubbery oil, which was clearly soluble in alpha-beta ethylenic acid molecules may combine kerosene, additively withan amine having one double bond, , amine having two double bonds in a single ali phatic chain or cycloaliphatic ring. Withsec ondary amines containing twonnsaturated ali- ' phatic or cycloaliphatic groups, it is apparent that four or more moles of alpha-beta, ethylenic acid may combine. Usually, the preseht products tion mixture, the temperature was raised slowly to 210° C. and was held at this point for 21 hours. linkages, Actually, experiment shows thattwo while three or more moles may combine with an ' stream of air was then started through the reac . ' Cannon. Paonucr Example 2 \ 54 parts of commercial‘ n-octadecyl-n-octa decenyl amine (iodine No.=45.4) and 10 parts of maleic ‘anhydride were reacted as above. The product was a dark, viscous oil when will be prepared from reactants in which the ratio 50 warm, only partly soluble'in kerosene. of moles of alpha-beta, ethylenic acid, to moles Cnnmcsr. Paonncr of unsaturated amine is within the range 0.5 to 5. To prepare said new chemical product the de Example 3 sired alpha-beta, ethylenic acid is reacted with the desired unsaturated amine at a temperature 23 parts of citraoonic anhydride were substi which may range from about 100° C. to about 250° tuted for the maleic anhydride in previous Exam C. for a period of several hours. The reaction ple 1. appears to involve both amide and imide forma Carmen. Paonncr tion, and-addition at or near a double ‘bond of the unsaturatedreactants, Amidi?cation catalysts, 60 Example 4 such as traces of alkali, may be employed. Ole ?né polymerization, atalysts, such as benzoyl 40 parts of maleic anhydride were used in place peroxide may also b; employed, but such do not, of the '20 parts in previous Example 1. Heating in general, greatly affect the rate of reaction and at 210° C., while, passing a slow air stream contribute to the formation of impurities. through the reaction mixture, was continued for To obtain the highest degree of polymerization 30 hours. in the. shortest period of time, certain reaction Cannon. Paonucr conditions have been determined to be of great ‘importance. The determination of these reac Example 5 tion conditions ‘actually constitutes an invention 70 within 'an invention, in thatit makes possible 24 parts of commercial fumaric acid were sub stituted for the maleic anhydride of previous the preparation of the most desirable products Example 1. with the minimum of time and effort. ‘In par ticular, it has been found that polymerization is The product was practically identical with that promoted by passing through the mixture, dur 75 of, Example 1. I g 2,412,“? 6 5 C. The product 0! Example 4 also contains free Cannon. Pnoirucr carboxylic acid groups. ‘ - Products containing free carboxylic acid groups maybereacted with alkalies, amines, heavy metal, oxides, etc., to yield polymeric salts which have} _ Example 6 21.4 grams of puri?ed oleyl amine (iodine No.=95.0) and 7.9 grams of pure maleic anhy useful properties in addition to those 0! the polymers alone. Salts. such as the sodium salt of the product of Example 4, may be used as dride were reacted in a vapor-heated vessel ' equipped with gas inlet tube, viscosimeter tube, thermometer, water trap and condenser. The sludge dispersers or detergents in lubricating oil. mixture was heated at 200:2“ C. by means of 10 The lead salt of the product of Example 2 may boiling m-cresol. During the ?rst part of the also be used as a thickening agent and a deter reaction a stream of dry methane was passed through the mixture. Later a slowv stream of dry air was substituted for the methane. The vis cosity of the reacting mixture was determined gent in oils. periodically by a'procedure such as that de scribed by Flory, J. A. C. S. 62, 105 (40). The following table summarizes the ob tained at various periods, and also gives 'the molecular weights of a few samples, as deter ‘ Viscosity Average a; manna) lggm units) product ' 5 __________ __ Methane..-_ l. 33 9_ _ _ _ _ _ _ _ _ _ . . _ _ _ --d0_-____ 1.40 __do ____ __ 1.49 l6___ mono-, dip, or polyhydric alcohols. Whensuch carboxyl-containing products are reacted with a long chain amine or alcohol, especially useful 20 products are obtained. which are made the sub ject of my co-pending application Serial No. 558,950, ?led October 16, 1944. The nature of the reaction which results in ' mined cryoscopically in benzene. Total hours of heating casusbemgd ' In generaLproducts of the present invention . which contain free carboxyl groups may be‘ em ployed as such, as the metal or amine salt, as‘ an amide, ‘or in some cases, as the esters of the formation of the new chemical product here 25 in described, is not clearly understood, but it is believed that the alpha-beta, unsaturated acid . reacts with the amine group of the amine, and ' ___________ -_’ also condenses, by proton transfer, with the un saturated amine at an ethylenic carbon atom of 1,760 ____________ - 27 _________________________ -_do____-- 1.55w ____________ __ 44 _________________________ --do ____ __ 1. 63 ____________ __ 30 same, or at a carbon atom near the double bond. The unsaturated amine undergoing condensation REPLACED METHANE W 1TH AIR AT THIS POINT 2. 27 2,240 6. 23 17. 20 ____________ -_ ____________ __ 3, 020 with a molecule of ethylenic acid, is probably _ linked by amide or imide formation to a di?erent molecule of ethylenic acid; so a type of linear 35 polyamide is formed. When the double bond of the unsaturated alcohol is nearer to the amino nitrogen than allowed by the conditions previ ously given, good yields of the desired products The product ‘was a clear, red, extremely viscous ?uid. ‘It was soluble in benzene and mineral ' are not obtained. It is believed that this is‘ the spirits, and partly soluble in SAE 30 Pennsyl result of the formation of stable, cyclic, inner 40 vania motor oil.‘ amides, rather than linear ,polyamides. The data clearly shows the e?ect- of air in in Various possible reactions which are believed creasing the rate of polymerization. However, might occur in the preparation of the new chemi it is also clear that a considerable amount of cal product that forms part of my new composi polymerization is obtained in the absence of tion of matter, are- as iollows, employing an 45 oxygen. The average molecular weight of the 9 unsaturated aliphatic primary amine and an hour sample corresponds to that. of a molecule containing about 5 monomer units. alpha-beta, ethylenic, monocarboxy, aliphatic acid: Crimean Pnonucr 50 Example 7 100 parts or inaleic anhydride and 270 parts of ' commercial oleyl amine were heated at 200° C. until re?uxing ceased. The temperature was then raised to 240° C. and held for 4 hours. A ' product sample at this point had a cryoscopic molecular weight of 2,400. - ~ ' - ' ‘ nR.cH,.cH=0H~cH,-cntnncrimiirl-nnwcmcmcoon n[a.cm.c=cn.cn,.om.n'.charm-1011 n".cn.cni'co- . + (ii-DEC . or I Carmen. PnonUc-r Example 8 56 parts of commercial dihydroabietyl amine were substituted for the 54 parts of octadecenyl amine employed in Example 1. ‘ The product had practically no acid value and was a very viscous oil, soluble in lubricating oil. It will now be noted that one of the above prod ucts, that of Example 2, was prepared from one molal proportion of a dibasic acid and one molal proportion of a monobasic secondary amine. Such products contain some free carboxyl groups. Analysis of the product of Example 2 indicates that somewhat less than the theoretical number of carboxylic acid groups remains. It is believed that this result may arise from some decarbox ylation at the temperature of reaction, i. e., 210° H R. 0 H2. CH. CHLCHLCHLRQCHLNH- 0H [ - R". CH: H. C 0- . 1 q +. (7l—1)HzO Where a dicarboxylic/ alpha-beta ethylenic acid, such. as maleic anhydride, is reacted with - . ‘9,419,557 ical Product, Example 1, less reagent is required a primary, unsaturated amine, it is believed that reactions analogous to the above take place with - for a desired improvement in viscosity index._ In the formation of polyimides. In this case the general, the percentages of such products which - reaction analogous to the ?rst one above would be: will be employed, varies from as little as 0.025% to as much as 5%, or even more, depending upon the use to which the oil is to be put. Thus, one object of my invention is the preparation of such 'improved lubricating oils, or lubricating oil com positions, by adding not less than about 0.025%. 10 or more than‘. about 5% of the hereindescribed chemical products or compounds, to lubricating 0 0 l I oils, such as are used in internal combustion 1' engines. . Such a product would be a substituted poly? ' succinimide. > ' . 15 Where more than'one mole of alpha-beta, eth ylenic acid is reacted with a. mole of unsaturated amine,.similar reactions probably occur, with the attachment of. two or more moles of ethylenlc acid at points in the unsaturated chain of the amine 20 at or. near the double bond. ' not remove all of the ole?nic groups of the un may be hydrogenated to remove ole?nic double bonds. Other chemical reactions maybe em ployed to modify the properties. of the polymers. For example, they may be treated with sulfur at ' elevated temperatures to form 'sulfurized poly an imide both p; the original amino hydrogen “atoms have been removed by reaction with a mers - useful as antioxidants‘ ‘and ?lm strength improves for petroleum or_fatty oils, or they may For this reason, the term be chlorinated, or. they may 'be both sulfurized and chlorinated to yield useful additives for heavy . “amide” will bé'used in the‘ claims in its broad ‘sense to include groups or linkages of either the , saturated reactants. 'If.desi'red,‘lthese products An imide may be looked upon as a special type of amide, or as a kind of double amide, since in carboxyl' group. , The hereindescribed new chemical products that form parts of my new 'compositionof mat ter, are, in general, unsaturated, as reaction does . duty oils. . . ' I conventional monoamide or imide type. Chemical products of the type herein contem In the above formula, R and R" represent alkyl 30 plated are referred ‘to as' addition-condensation slfoups which contain one or more carbon atoms, polymers. This is in conformity with nomen 'and R’ is an alkylene 'group which may contain clature in Organic Chemistry, Gilman, 2nd edi one or more carbon atoms. 12 is a whole number. tion, volume 1, page 702. In addition to the above reactions, several Sald products are addition polymers in the others are conceivably possible. However, it is 35 sense that some intermolecular reaction occurs understood that the exact reactions are a matter without the elimination of any atoms or groups, of speculation ,or conjecture, and may vary, de such reaction being that involved during the cou pending, in part, on the particular reactants se pling of the alpha-beta, ethylenic acid to the un lected. , Such reactions are not to be construed saturated hydrocarbon group of the amine. Fur as a limitation in' any respect, but are submitted‘ 40 ther, condensation occurs through the reaction of in order to show the diverse nature of the pos sible or probable reactions involved, and addi tionally, to indicate the inability adequately to portray the invention in terms of conventional chemical formulae. , - My invention consists in using the chemical products above described as lubricating oil ad ditives for increasing the viscosity index of such. oils. As speci?c examples of my present inven tion, the following examples are given of a new composition of matter, consisting of a mixture of mineral oil and the polyamides or polyimides previously described. Courosrnon or MATTER Example 1 2% by weight of the product of previous Ex ample 7, above, was added to a lubricating oil having a viscosity index of 60, and a viscosity at 210° F. of 46 seconds. ' The resulting clear oil so lution had a viscosity index of 95 and a viscosity of 53 seconds at 210° F. Comrosrrron or Mar-ran the carboxylic acid group with the amino group, yielding water as a product. In general, poly merization of the reactants employed will be pos sible only when both addition and‘condensation occur. Having thus 'described my invention, what I claim as new and desire to secure by Letters Pat ent is: 1. A. lubricating composition, comprising a lu bricating oil and an unsaturated amine-alpha beta, unsaturated carboxylic acid‘addition-con densation polymer; said amine containing at least' one ethylenic unsaturation and having at least 4 singly bonded carbon atoms between the eth ylenic double bond and the nearest amine nitro gen atom, said amine having at least one hy drogen atom directly linked to an amino nitrogen atom, and containing less than 32 carbon atoms per nitrogen-attached hydrocarbon group; said ‘acid containing less than 10 carbon atoms and free from vinyl radicals; said polymer being mixed with said lubricating oil in an amount within the range of .025% tdabout 5%. , 2. A composition of matter, as de?ned in claim Example 2 . 1, wherein all radicals attached to the amine ni 2% by weight of the product of previous Ex trogen atom are aliphatic radicals. ample 3, above, was added to a lubricating oil hav-. 3. A composition of matter, as de?ned in claim ing a viscosity index of 70 and a viscosity of 210° 1, wherein all radicals attached to the amino nitrogen atom are straight chain aliphatic radi F. of 44.9 seconds. The resulting oil had a vis cosity index of 90.0 and a viscosity at_210° F. of 70 cals. , ' 48.5 seconds. 4. A composition of matter, as de?ned in claim Greater or lesser e?ects on viscosity index than 1, wherein the amine contains a single amino 1 those illustrated above may be obtained by add nitrogen atom and all radicals attached to said ing more or less reagent. Using a product of amino nitrogen atom are straight chain aliphatic higher intrinsic viscosity, such as that of Chem 76 radicals. - 2,412,557 . 5. A composition of matter, as de?ned in claim ' 1, wherein the amine contains a single amino ni trogen atom; all radicals attached to said amino nitrogen atom are straight chain aliphatic rad icals, and the alpha-beta, monoethylenic acid is l0 1, wherein the amine contains a single amino nitrogen atom; all radicals attached to said amino nitrogen atom are straight chain aliphatic radi cals, and the alpha-beta, monoethylenic carboxy acid is fumaric acid. 8. A composition of matter, as de?ned in claim 1, ‘wherein the amine contains a single amino 6. .A composition of matter, as de?ned in claim. nitrogen atom; all radicals attached to said amino 1, wherein the amine contains a single amino nitrogen atom are straight chain aliphatic radi nitrogen atom; all radicals attached to said amino nitrogen atom are straight chain aliphatic radi l0 cals, and the alpha-beta,- monoethylenic carboxy dicarboxy. I cals, and the alpha-beta, monoethylenic carboxy ~ acid is maleic acid. 7. A composition of matter, as de?ned in claim ‘acid is citraconic acid. CHARLES M. BLAIR, JR.