US2355257A - Mineral oil composition - Google Patents

Description

Patented Aug. 8, 1944 MINERAL OIL COMPOSITION Darwin E. Badertscher, Woodbury, N. .L, assignor to Socony-Vacuum Oil Company, Incorporated, a corporation of New York No Drawing. Application June 11, 1943, Serial No. 490,479

(01. asa -51) 13 Claims.

This invention has to do with the stabilization of mineral oil fractions and more particularly has to do with the stabilization of such fractions by the incorporation therein of a small amount of a novel compound, or novel class of compounds, capable of inhibiting a viscous mineral oil against the deleterious efiects of oxidation.

It is well known to those familiar with the art that the deleterious effects of oxidation upon a mineral oil fraction manifests itself in various ways depending upon the source of the oil, that is, the crude from which it is derived, the refining treatment to which the 'oil has been subjected and the particular conditions under which the oil is subjected to oxidation. For example, mineral oil fractions refined for use as lubricants have a tendency to oxidize under conditions of I use with the formation of sludge or acidic oxidation products. Also, in the case of internal combustion engines, particularly those operating with high cylinder pressures, there is a'decided tendency for the ordinary lubricating oil fractions to form carbonaceous deposits which cause the pistonrings to become stuck in their slots and which fills the slots in the oil ring or rings, thus materially reducing the efficiency of the engine.

Among the numerous improving agents proposed for use in mineral oil fractions are various metal salts and metallo-organic compounds.

solubility in non-associated solvents. Further distinctions between chelate metal salts and nonchelate metal salts may be obtained by referring to Sidgwick's The Electronic Theory of Valence, Oxford University Press, 1927, chapter 14.

The oil improving agents contemplated herein,

which effectively stabilize mineral oil fractions against the deleterious eifects of oxidation, are the chelate metal salts of a salicylidene imlne which may be unsubstituted or substituted. These metal salts may be represented by the following general' formula:

wherein R is selected from the group consisting alkoxy, aroxy, halogen, nitro, nltroso and cyano;

R is selected from the group consisting of hydrogen and hydocarbon radicals such as alkyl, aryl, alkaryl and aralkyl; and M represents the hydrogen equivalent of a metal.

All metals capable of forming chelate metal salts are contemplated, fisconstituents of the metal salts described above. Illustrative of such metals are: sodium, copper, beryllium, magnesium, boron, aluminum, silicon, arsenic, antimony, chromium, iron, cobalt, nickel, palladium, platinum and iridium. Particularly preferred of such metal constituents are the metals nickel, copper and cobalt in the following formsynlckelous, cupric and'cobaltous.

While the imino hydrogen (=N-H) may be present in the metal salts contemplated herein,

it is preferred that the imino hydrogen be replaced by a hydrocarbon radical such, for exhigh vapor pressures in addition to increased ample,as an alkyl or an aryl radical. Radicals representative of these classes are butyl, dodecyl and tolyl.

quently are contemplated herein. Typical of the C-substituents are alkyl, aralkyl and alkaryi groups.

The chelate metal salts of phe-tyrsnennea Y above may be prepared by the general method described in detail by Hunter and Marriott in the Journal of the Chemical Society (London) 1937, page 2000. Illustrative of the general method and of the chelate metal salts prepared thereby are the following examples.

E'xsurnl Nickelous salicwlidene N-n-butyl imine A hot solution of 17.5 grams oi salicylaldehyde in 20 cc. of 95% ethanol was added to a hot solu- .tion of 11 grams of mono-n-butyl amine in 20 cc. of 95% ethanol, the latter solution being constantly agitated. The reaction was strongly exothermic and caused the mixture to boil vigorously. A hot solution of 18 grams of nickelous acetate, Ni(OAc):.4I-Ia0, in 100 cc. of 50% aqueous ethanol was added to the aforesaid mixture, with constant agitation. About 44.5 gramsof alcoholic potassium hydroxide containing 183% of 85% potassium hydroxide was then added. A dark green oil immediately formed and crystallized on cooling. The olive green crystals obtained by filtering the last mentioned mixture were washed on the filter with distilled water, then with 50 cc. of 95% ethanol in three portions and finally with 20 cc. of absolute ethanol. Crystallization from acetone yielded dark olive green crystals melting sharply at 139.5-140' C. (uncorrected); On analysis the following data was obtained.

. Cal'd. ior Analysis Found CHnNNi 1722 P" 14 3 Ni k l Nigm mn 6.46 I 6.83

EXAIPLI II Cupric salicylidene N-n-butul imine To a hot solution of 8.2 grams of cupric acetate monohydrate and 6 grams of mono-butyl amine in 120 cc. of 50% aqueous ethanol was added, with shaking, a solution of 10 grams of salicylaldehyde in 10 cc. of 95% ethanol. After the mixture had cooled, the dark olive green crystals formed thereon were filtered, washed in the filter first with distilled water and then with absolute ethanol-and were finally air dried. Analysis of these crystals showed the following;

m M Cases.

Peron;8 Permit11s 4 Copper 16. Nitrogen 6.44 0.8

Exnn'm: III

Cobaltous salicyliderte N-n-butyl imine This material was prepared from 25 grams of salicylaldehyde, 15 grams of mono-butyl amine and 24.5 grams of cobaltous acetate tetrahydrate using a procedure similar to that described in Example I. The product was a crystalline, brick red solid which analyzed as follows:

Analysis Found gflg Pacing, Percento M n e 14. 3 16. 87

Exnrru: IV

Cobaltous salicylidene N-n-dodecyl imine A hot solution of 25 grams (excess) oisalicyl- I aldehyde in 30 cc. of absolute ethanol was added to a hot solution of 37 grams of 'mono-n-dodecyl amine in 70 cc. of 95% ethanol, the mixture being agitated throughout the addition. The reaction was exothermic causing the mixture to ,boil vigorously. To the resulting mixture was added a solution of grams of cobaltous acetate tetrahydrate in' a mixture of 50 cc. oi water'and 60 cc. of 95% ethanol. The light yellow imine solution immediately turned brown on additionof the cobalt salt. After heating on the hot plate at a temperature of about 60 C. for about ten minutes a with I shaking, 77-78 grams of 14% alcoholic potassium hydroxide was added. The mixture now became green due-to the separation of a dark green liquid phase. Five hundred cc. of distilled water were added to the reaction mixture and the resulting mixture was extracted thoroughly with petroleum ether until the petroleum ether extracts were no longer, colored; On evaporation of petroleum ether from the extracts, 57.5 grams of a dark green pasty residue were obtained. A small drop of this residue fused in a porcelain crucible with about 2 to 3 cc. of borax gave a brilliant blue coloration, indicating, the presence of cobalt.

To demonstrate the eflectiveness of the salts contemplated herein as oil improving agents, a blank oil and blends of typical improving agents of the type contemplated herein were subjected to an oxidation test in order to determine their relative susceptibility to oxidation. In this test a 300 gram sample of the blank oil or of the oil blend was heated at 350 F. while two liters of air per hour were blown over their respective surfaces and while stirring the samples at a constant rate with steel paddles. The oil used was a commercial, solvent-refined S. A. E. 30 motor oil. Samples were withdrawn at specified intervals (in days) and the volume per cent of sludge was determined in each case. The results are set forth below in Table 1.

In order to evaluate the relative stability of a motor oil and of blends of the same motor oil and typical improving agents of the type contemplated herein the blank oil and the blends were tested in a standard C. I". R. knock test" en ine.

The test involved operating the engine first with the oil and then with the oil blend at an approximate speedof 1200 R. P. M. with the throttle set Just below detonation using a compression ratio of 7:1 .at a fixed jacket temperature of 400' F.

cylidene imine, said At the end of 28 hours, the following inspections were made: 1. The piston:

a. Degree of ring sticking being an entirely free ring and 360 a totally stuck ring) b. Per cent of filling of oil slots 0. Deposits (grams) 2. Used oil:

a. Kinematic viscosity (K. V.) at 210 F. b. Neutralization number (N. N.)

The results obtained are listed below in Table 2 where oil A is a motor oil blank, oil B is the some oil containing 0.5 per cent of ni-ckelous salicylidene N-n-butyl imine and oil C is the same oil containing 1 per cent of nickelous salicylidene N-n-dodecylimine.

The amount of improving agents which may. be used in the oil will vary more or less with the oil and with the conditions of use. While in general the desired improvement can be effected with amounts ranging from about 0.01 per cent to about 10 per cent, the preferred amounts will fall within the range of about 0.1 per cent to about 5 per cent depending on solubility.

It is to be understood that while we have described hereinabove preferred procedures for synthesizing improving agents of the type contemplated herein and have designated certain illustratlve reactants and have also shown certain preferred mineral oil fractions which may be employed, the invention is not confined to the specific detailed procedural operations, reactants or oils so described but includeswithin its scope what-' ever changes fairly come within the spirit of the appended claims.

I claim:

1. An improved mineral oil composition com-. prising a viscous mineral oil having in admixture therewith a minor proportion, sufllcient to stabllize said mineral oil against the deleterous effects of oxidation, 0! a chelate metal salt of a sailsalt being represented by the formula wherein R and R. are selected from the group consisting of hydrogen and a hydrocarbon radical and M is the hydrogen equivalent of a metal possessed of the capacity to form a chelate metal 2. An improved mineral oil composition comprising a viscous mineral oil having in admixture.

therewith a minor proportion, from about 0.01 per cent to about 10 per cent, of achelate metal salt of a salicylidene imine, said salt being represented by the formula 1 eifects of oxidation, of a chelate metal salt of a salicylidene imine, said salt being represented by the formula v wherein R and R are selected from the group consisting of hydrogen and a hydrocarbon radical and M is the hydrogen equivalent of a metal possessed of the capacity to form a chelate metal salt and is selected from the group consisting of copper, cobalt and nickel.

4. An improvedmineral oil composition comprising a viscous mineral oil having in admixture therewith a minor proportion, sufflcient to stabilize said mineral oil against the deleterious eflects of oxidation, of a chelate metal salt of a salicylidene imine, said salt being represented by the formula wherein R and R are selected from thegroup consisting of hydrogen and a hydrocarbon radical and M is the hydrogen equivalent of a metal possessed of the capacity to form a chelate metal salt and is selected from the group consisting of copper (cupric), cobalt (cobaltous) and nickel (nickelous).

5. An improved mineral oil composition com prising a viscous'mineral oil having in admixture therewith a minor proportion, suflicient to stabilize said mineral oil against the deleterious effects of oxidation, of'a chelate metal salt 'of salicylidene imine.

6. An improved mineral oil composition comprising a viscous mineral oil having in admixture therewith a. minor proportion, suificient to stabilize said mineral oil against the deleterious efi'ects of oxidation, of a chelate metal salt of an N-substituted' salicylidene imine 7. An improved mineral oil composition comprising a viscous mineral oil having in admixture therewith a minor proportion, sufiicient to stabilize said mineral oil against the deleterious eflects of oxidation, oi a chelate metal salt of an N-aryl substituted salicylidene imine.

8. An improved mineral oil composition comprising a'viscous mineral oil having in admixture therewith a minor proportion, sufllcient to stabilize said mineral oil against the deleterious eflects oi oxidation. or a chelate metal salt oi an N-alkyl substituted salicylidene imine.

9. An improved mineral oil composition comprising a viscous mineral .oil having in admixture therewith a minor proportion, suilicient to stabilize said mineral oil against the deleterious eiiects of oxidation, of a chelate metal salt of a C-substltuted salicylidene imine.

10. An improved mineral oil composition comprising a viscous mineral oil having in admixture therewith a minor proportion, sumcient to stabilize said mineral oil against the deleterious eflects of oxidation, of a chelate metal salt or an N-substituted, C-substituted salicylidene imine.

ture therewith a minor proportion, sumcient to stabilize said mineral oil against the deleterious eflects 0! oxidation, of cobaltous salicylidene N-n-butyl imine.

DARWIN E. BADERTSCHER.