US2388059A - Lubricant - Google Patents

Description

- Patented Got. 320, 1945 zest,

LUBRICANT Q Robert D. Herlocker, Hammond, and Milton Paul Kleinholz, East Watkins, Chicago, Ill., assignors to Sinclair Refining Company, New York, N. Y., a corporation of Maine Chicago, 1116., and Franklin M.

No Drawing. Application April 24, 1943-.

Serial No. 484,471

Claims. (Cl. 252-50) This invention relates to an improved turbine oil. It relates more particularly to a lubricating oil composition consisting principally of apetroleum lubricating oil, the characteristics of the oil being modified by the addition thereto of a relatively small proportion of a, diaminomethane derivative of the class represented by the structural formula:

where R1N is a piperidino radical; R2 is either 7 hydrogen or an alkyl or an aryl radical, R3 and R4 are alkyl or aryl radicals or else NRIiRA is a second nitrogen-containing heterocyclic radical, for instance piperidino. The piperidino radical may be represented by the structural formula:

E2C\ CHz-CH: A lubricating oil composition to be used as a turbine oil, and especially in modern marine steam turbines, is subject to very exacting reeuirements. Not only must it perform the ordinary function of lubricating the turbine over pro longed periods without interruption but usually it must serve as a coolant, to lubricate the gearing mechanism, to operate oil-actuated governors or control mechanisms having very nice tolerances and lubricate other auxiliary equipment.

Many lubricating oil compositions highly satisfactory for the lubrication of other mechanisms have been found wholly unsuitable for use as a turbine oil. This is probably due primarily to the fact that in normal use turbine oils rapidly become contaminated with water. Whatever the cause, it is generally recognized that the performance of a turbine oil is not predictable from conventional tests applicable to other oil lubricants.

An essential characteristic of a satisfactory turbine oil is its ability to avoid the rusting of the metal parts within the oil system of the turbine and auxiliary apparatus under operating conditions. 1

The use of many lubricating oil compositions, otherwise satisfactory as turbine oils, has re-' sulted in the rusting of metal parts within the oil system with consequent serious interference with the operation of oil-actuatedgovernors and other parts depending upon close tolerances. The results of such rusting not only interfere with the operation of and tend to clog the deliportion of a diaminomethane derivative of the class previously identified herein. Compounds of this class found to be especially eflective in inhibitin rusting under conditions usually encountered by turbine oils are those in which each nitrogen atom is included in a piperidino radical.

- Such compounds found to be especially eflective in the preparation of'our improved turbine oils of the present invention may he exemplified by the following:

Dipipeildino-methane, which we believe to be represented by the structural formula:

Dipiperidino-ethane, which we believe to be represented by the structural formula:

And phenyl dipipeiidino-methane, which we believe to be represented by the structural formula:

' CHr-CHa CHr-CHQ mo N-on-N cm CHFCHQ 5 CHr-Ci where R2 is a phenyl radical.

It will be understood that the foregoing specific compounds are illustrative of the class and that our invention is not limited to the use of these particular compounds but contemplates the use of other members of the class in the compounding of our improved turbine oils.

Many of the compounds suitable for use in compounding our improved turbine oils are known to the art and may be readily prepared by known methods. In general they can be'produced as condensation products of amines and aldehydes.

For example, the dipiperidinomethane, referred to herein and in the appended claims, was prepared as follows: 91.5 grams of 93% piperidine (1 mole) was placed in a 250 c. c. Erlenmeyer flask. To this there was added portlonwise with In referring to dipiperidinomethane, dipipershaking over a period of minutes 44.1 grams idinoethane and phenyl dipiperidinomethane of 34% formalin (0.5 mole formaldehyde). Durherein and in the appended claims, we refer, reing this addition, considerable heat was evolved spectively, to the above-described products, aland the temperatureof the mixture increased to A? though, of course, we intend to refer by these about 1'10 F. Before the addition of the formalin terms to the same materials by whatever prowss solution was completed, two phases formed in the they maybe made. It isunderstood that ourflask, a lower aqueous phase and an upper orinvention is not predicated uponthe identificaganic phase. The lower phase was separated and tion of the addends as a matter of terminology. on salting out with potassium carbonate yielded In our co-pending application" Serial No. 2 c. 0.015 a red liquid. The upper'organic phase 484,470, filed concurrently herewith, we have dewas distilled, four cuts being taken. The condiscribed and claimed improved turbine oils in tioris under which the cuts were taken. and the which the rusting characteristics of the lubricatamounts thereof wereas follows: ing oil constituent are modified by incorporating 15 therewith a small proportion of a diamlnomethane derivative of a class of chemical comherein. In said application we have described and claimed speciflcallyturbine oils comprising compounds of the general class in which at least pholino radical. The present invention is directed to turbine oils in which the addend is The second out was found by analysis, by the a specie of the general class in which at least one one ofthe nitrogen atoms is included in a mor- Dumas Method, to contain 15% nitrogen as comof the nitrogen atoms, and advantageously eac pared with the theoretical nitrogen content of is included in a piperidino radical. 1 15.38% for pure dipiperidinomethane. At 20 C. The turbine oils to which the present applicait had a specific gravity of 0.9269 and a refraction is specifically directed possess certain adtive index of 1.4886. This second cutwals equivavantages 'over those in which the morpholino lent to 81.6% of the theoretical yield. The avercompound is incorporated particularly with reuse molecular refraction of several batches of the spect to prolonged effectiveness of the addend product thus prepared was found to be 56.57 as under conditions where considerable amounts of against a theoretical molecular refraction of water become admixed with and areseparated 56-48 for pure dipiperidinomethane. from the turbine on while in use. This advantage residue. o 1. was a viscous, dark red 5 isparticularly apparent where relatively smaller d. Y proportions of the addendare used.

Seven other preparations were made/following Though our present invention is independent the proceduresubstantlally as described exceptof any theory as to the reasons for this beneficial ing a slight variation in the purity of the result, it'appears-to be due, in part at-l'east, to

piperidine employed. The products were found 40 diflerences in solubility of the addends in water. to be substantially uniformly eiiective in our im- For instance, dimorpholinomethane is, readily proved turbine oil. soluble in water, even at room temperature, while The dipiperidinoethane referred to herein and the dipiperidinomethane is soluble in water. only .in the appended claims was prepared as follows: to the extent of about 0.45% to 0.50% at 140 1".

1'19 grams of 95% pure piperidine (z'moies) was The l bricating oil constituent of our improved placed in a 3-neoked' flask, equipped with aturbine oil may consist of a petroleum lubricatstirrer, and there was added thereto 30 grams of ing fraction such as ordinary specified for turanhydrous potassium carbonate. To this mixbine oils. It may with advantage'be a highly retime there was added 48.4 grams (1.1 moles) of fined lubricating oil, for instance an acid-treated acetaldehyde over. a period of 2 hours, with petroleum lubricating oil fraction or one which stirring, the mixture being kept at a temperahas been subjected to solvent refining such as ature below F. during the addition, by cooling. phenol-treated fraction from East Texas crude. The reaction mixture was allowed to stand-over- Solvent reiinedils have generally been iound night and the aqueous potassium carbonate layer more resistant to slut-18 1 8 n the m' removed. The organic layer was then filtered 55 oils. For example. lubricating oils such as a and topped at a temperature of 155 R, and an 'phenol-treated-East Texas neutral (Sample 1),

. grams of the product. t

absolute pressure of 4.5 millimeters of mercury and an 'acid treated fraction from-a Mid-Conto remove any water and unreacted volatile tinent crude, (Sample H), mm the'followind materials present. It was a darir colored liquid. characteristics have been used with advantage:

The phenyl dipip'eridinomethane referrcd'to Q herein and in the appended claims was prepared Bumble! o as follows: 184.2 grams or pure piperidine (1.5 moles), was placed in a 500 c. c. Erlenmeyer v an as: flask and there was added thereto portlonwise, Fg i f; over a period of '10 minutes withshaking. 19.!) I 2 grams (one mole) of benzaldehyde. During this Wm" 22- addition the temperature of the mixturerose to Pour, 4.-. I ab u 1". The solution clouded butQbefore gmggggggg; 8. 31% permitting it tosolidify, 300 c. c. of hot ethyl 0mm residue oomlifib'iiii'rl na. M M35 alcohol was added. Upon cooling this mixture 70 M90 there was obtained 159 grams of phenyl diii'ltt'tifm ifiasa" I plperidinomethane as a white solid having a meltg flg ffgg 81%; 81 E, ing point of it'd-178 F. From the mother liquor I rdN wigtic mihdh'j. II- 0. x 1: 0.1 3.115 and wash liquors there was obtained 15 additional 1 m By incorporating a mind:- proportion of a compound of the nreviously identified class in a. suitable lubricating oil constituent, rusting or the For example, the incorporation of 0.05% of any one of the compounds specifically identified herein has been found to result in a the American society of Testing Materials and designated, respectively, A. S. T. M. Specification D-655-42-T for Turbine Oils and Proposed for Determining Oxidation Character- Turbine Oils, Section III, Technical Committee C, A. S. T. M. Committee 13-2, July 2, Iss1,

der such conditions, they are compatible with known anthoxidants, for example bis-(p-dimethyieminophenyi)masthene which may with advantage be used in conjunctiontherewith in our improved turbine oils in order to combine high oxidation resistance with the anti-rusting characteristics of our turbine oils.

In the compounding of our improved turbine oil, a small amount of an addend of the aboveiurther to improve our turbine oil were used.

our present invention further to improve the properties thereof in various respects. The previously noted bis-(p-dimethylaminophenyl)- methane has been used with special advantage .with respect to its oxidation characteristics.

The following examples of turbine oils, and their characteristics with respect to rusting, will Clean specimen, 1. e. no rust.

B++ Only trace of rust.

B+ Up to 5% of surface rusted.

.B 5% to 25% of surface rusted. c. C 25% to 50% of surface rusted. D 50% to-% of surface rusted. E 75% to of surface rusted.

The rusting characteristics of our improved turbine oils, having the indicated composition and in which the mineral oil constituent was that previously identified as Sample I, were found to be cs follows: J Addend Rusting Addend oonocntmcharactert n istio i i "'idfiTYfi "6135' 132+ p per ome one.

Do 0. 10 A Do 0. 20 A Do 0. 50 A Dipiperidinoethanm 0. 02 0 Do 0. 05 A Do L 0. 30 A Phenyl dipiperldinomethsnm 0. 02 B Do. 0. 05 A Do 0 20 A As appears from the resultsoi these tests.

tection agninst rusting and, only a very small amount of where even smeller proportions of the addend The oxidation induction period of the oil desigmeted flample I was hours. @270 of bis-(p-dime'thylmninophenyl) -methane in our improved turbine oil cont ng 0.1% and 0.3%, respectively, of dipiperidinomethcne has resulted in increasing the oxidation induction.

period of the turbine oil to as high as 825 hours and 850 hours. By this inclusion, the rusting that, by the "use of relatively small proportions of bis- (p-dimethylaminophenyl) -methane in conjunction with one of the diaminomethane derivatives previously identified,

The inclusion of test repeated until where smaller dino compounds upon conditions'oi use.

I about 0.01% portions even in excess of 1% may the rusting complete protection portion of the same oil after oxidation hours did not give com lete protection against rusting. Portions or the same Sample I, containing 0.2% dipiperidinomethane, were oxidized for '12. and 192 hours, subjected respectively, and then to the a s. T. M. me test. These pre-oxidired against rusting. Another the test, they seemed to have or the etching of the test specimen.

A further notable characteristic of our int-'- proved turbin oil is its ability to withstand cone tamination'bs water without material separation 01! the addend from the oil or substantial detenoration o! the addend itself.

As previously noted herein, our improved turbine oil oi! our present invention has been found to be'especially resistant to extraction or the addend from the oil by water. This is illustrated by results of Thereafter, the water is again removed and the rusting of in this manner our turbine oil comprising 0.1% or dipiperldinomethane,-rusting was repeated seven times while, or dimorpholinomethane, peared on the third best. Using 0.2% of either or these addends, the rusting inhibition was maintained throughout eight successive tests but,

proportions oi the respective adused, the characteristic of the piperia trace of dends. were traction by water tage.

As we have previously stated herein,

is frequently a. distinct advandependin the addend may with ad- "be used in proportions ranging from to 1% by weight or the oil. Provantage such larger-proportions round necessary. Though proportions less than 0.01% maybe used, such smaller proportions are usually not suiilciently eilective. Accordin8- tests in which the prescribed rusting- 9 mm the class the test specimen I rusting apof increased resistance to exbut 1y, proportions ranei s from about 0.01% to ab ut 1% are generally recommended;

We claim:

1. An improved turbine oil petroleum lubricating tion,'enective to retard rusting, or a diaminO methane derivative of the class represented by the structural formula which comprises a /R hat-ca! 1 l R: where BIN is a piperidino radical, Re is selected from the class consisting of hydrogen, alkyl and aryl radicalsand NRaRs is a radical selected from the class consisting of nitrogen-containinll heterocyclic radicals and nitrogen-contain! radicals wherein R3 and R4 are either alkyl or a ry r 2. Animproved turbine oil which comprises a petroleum lubricating oil containing from about 0.01% to about 1% of a diaminomethane derivative of the class represented by the structural formula V mN-cn-u 1!: Bl

where RiN is a piperidino radical, R2 is selected 0.05% to about 1% methane. v

ROBERT .no 211;! MILTON PA mom. WATER oil containing a propor-