US3438897A - Engine lubricating compositions - Google Patents

Description

United States Patent Office 3,438,897 Patented Apr. 15, 1969 3,438,897 ENGINE LUBRICATING COMPOSITIONS Bennett M. Henderson, Edwardsville, IIl., assignor to Shell Oil Company, New York, N.Y., a corporation of Delaware No Drawing. Filed Oct. 10, 1966, Ser. No. 585,261 Int. Cl. Cm 1/34, 1/08; C08f 19/00 US. Cl. 25232.7 8 Claims ABSTRACT OF THE DISCLOSURE Mineral lubricating oil compositions containing basic alkaline earth metal petroleum sulfonates and a mixture of the copolymer of C-vinyl pyridine and an alkyl methacrylate with a succinimide of mono (polyolefin) succinic anhydride and a polyalkylene polyamine have improved stability, detergent-dispersant, antiwear and anticorrosion properties. The compositions can optionally contain a zinc dialkyl dithiophosphate.

This invention relates to novel multi-functional compositions such as lubricants, fuels, greases and the like containing a novel additive capable of imparting to said compositions detergency, wear and corrosion inhibiting properties.

The use of non-ash-forming polymeric nitrogen-containing compounds as detergents in fuels and lubricants is well known in the art. Polymers of this type include copolymers of vinyl pyridine or N-vinyl pyrrolidone and long-chain alkyl methacrylates, or mono(polyolefin)succinimides of mono(polyolefin)succinic anhydride and polyalkylene polyamine. Although polymers and copolymers of this type are excellent detergent-dispersant oil additives they lack corrosion and wear inhibiting properties and therefore require the presence of fortifying agents capable of inhibiting corrosion and wear. The use of fortifiers in conjunction with such detergents, however, presents new problems such as interaction of the additive mixture or interference with each others functions resulting in general ineffectiveness of such compounded lubricants, particularly when they are used in engines operating under stop-and-go conditions or severe temperature and pressure conditions. Where some such additive combinations in lubricants have been found to be successful, cost increase, short lubricant life and the restriction 'of their use to special types of engines has made use of such lubricants unattractive.

It has now been discovered that a multi-functional composition such as a mineral lubricating oil composition which possesses excellent detergent-dispersant properties as well as outstanding stability and wear and corrosion inhibiting properties can be obtained by addition to such a composition of from 0.1% to 10% each of (I) a mixture of two dissimilar non-ash-forming nitrogen-containing polymeric detergent-dispersants consisting of (A) a copolymer of vinyl pyridine and at least one acrylate ester in the molecular weight of from about 1500 to 2,000,000 and a nitrogen-containing polymer (B) which is an amidoamine and/or imino derivative of mono(polyolefin)succinic acid anhydride, e.g., a succinimide of a mono(polyolefin)succinic anhydride and a polyalkylene polyamine, or the salts, amides, imido or imino derivatives of polyolefin monocarboxylic acid and polyalkylene polyamine, the polyolefin group having a molecular weight of from 800 to 5,000,000 and (II) from about 0.1% to 15% of a highly basig alkaline earth metal petroleum sulfonate, the petroleum sulfonic acid portion having a molecular Weight range of from 350 to 1500, preferably between 400 and 800. The highly basic alkaline earth metal petroleum sulfonate functions synergistically with the polymeric ,non-ash-forming detergent mixture by increasing their dispersant-detergent properties and imparting corrosion and wear inhibiting properties, particularly at elevated temperatures as encountered under heavy duty engine operating conditions, without imparting the normally undesirable side effects normally produced by ash-forming additives such as sludge, metal deposits and the like.

The nitrogen-containing polymers of Group IA and IB as defined can be prepared by any suitable means such as described in US. Patent 3,215,632 and can be illustrated by the following examples: Nitrogen-containing polymers of Group I-A namely copolymers of vinyl pyridine and C alkyl methacrylates, having a molecular weight range of from 1500 to 2,000,000, preferably between 200,000 and 850,000 include (1) copolymer of 25% 2-methyl-5-vinyl pyridine and stearyl methacrylate, molecular weight 200,000, (2) 30% stearyl methacrylate, 51% lauryl methacrylate, 14% methyl methacrylate and 5% Z-methyl-S-vinyl pyridine, molecular weight 600,000, (3) copolymer of 14% methyl methacrylate, 54% lauryl methacrylate, 27% stearyl methacrylate and 5% 2-methyl-5-vinyl pyridine in weight ratio of 16:49.7:28.8:5.5, molecular weight 830,000, (4) copolymer of lauryl methacrylate, stearyl methacrylate and Z-methyl-S-vinyl pyridine in weight ratio of 60:35 :5, molecular weight 810,000 and (5) a copolymer of 2- rnethyl-S-vinyl pyridine, lauryl methacrylate and stearyl methacrylate in a weight ratio of 7.5 :58:34.5, molecular weight 31,000. The polymer of Group IB can be made by the process described in US. Patents 3,215,632 or 3,215,707 or 3,202,678 or Canadian 681,235 and can be illustrated by examples (1,) succinimide of mono(polyisobutylene)succinic anhydride and tetraethylene pentamine, the polyisobutylene radical having a molecular weight of about 1000, (2 amido-amine derivative of polyisobutyl monocarboxylic acid and tetraethylene pentamine having a molecular weight of about 1000, (3 succinimide of mono(polypyropylene)succinic anhydride and diethylene triamine, the polypropylene radical having a molecular weight of 800-1500, (4 diimide of mono- (polyisobutylene)succinic' anhydride and tetraethylene pentamine, the polyisobutylene radical having a molecular weight of 800-1500.

The nitrogen-containing polymers which are preferred are the copolymers of Groups I-A are (2), (3), (4) and (5) and the nitrogen-containing compounds of Groups IB are (1 (2 (3 and (4 Particularly preferred is the mixture of the polymer (4) of Group LA and the compound (1 of Group IB. The amounts of compounds 3 of Groups I-A and I-B can vary from 10-90% to 90- 10% respectively, and the total amount of the additive mixture can vary from 0.5 to 20% by weight.

The highly basic alkaline earth metal (Ca and/r Ba) petroleum sulfonate can be made by suitable means known in the art such as described in British Patents 790,471 and 818,323 or US. Patent 2,865,956. The basic calcium petroleum s-ulfonates (M.W. 300-800) are preferred. By basic sulfonate is meant that the end product has a basicity excess of 20% and up to 1000% and preferably between 40% and 800% in excess of that normally required to neutralize the acid to produce the normal salt. Other types of sulfonic acids in the molecular weight range of 350 to 800 and derived from olefinic polymers, alkyl aromatic compounds, e.g., alkylated benzene, 0r alkylated naphthalene also can be used in forming the basic calcium and/or barium sulfonate salt, such as basic calcium diwax benzene sulfonate, basic diwax naphthalene sulfonate and the like, the basicity being in excess of about 50l80% and the molecular weight of the compound between 450 and 750.

When desired, additional improvements with respect to oxidation stability and scufiing inhibition can be imparted to the oil compositions of the invention by incorporating small amounts (0.0l%-2%, preferably 0.1%1%) of phenolic antioxidants such as alkylphenols,, e.g., 2,6-ditert.butyl-4-methyl phenol or p,p'- methylene 'bisphenols such as 4,4'-methylene bis(2,6- ditert.butyl phenol) or arylamines such as phenyl-alphanaphthylamine; dialkyl sulfides and mixtures thereof, e.g., dibenzyl disulfide, didodecyl sulfide. Anti-scuffing agents include esters or metal salts of organic phosphites, phosphates, phosphonates and their thio derivatives, such as C;, trialkyl phosphites, or phosphonates, e.g., tributyl, trioctyl, trilauryl, tristearyl, tricyclohexyl, tribenzyl, tricresyl, triphenyl phosphites or phosphates, or Ca, Zn, Pb salts of alkyl thio phosphates, e.g., as well as their thio derivatives, Zn bis(2-ethylhexyl)dithiophosphate, Zn dioctyl dithiophosphate Zn bis(alkylphenyl)dithiophosphate, P S -terpene reaction product, phosphonates such as dibutyl methane phosphate, dibutyl trichloromethane phosphonate, dibutyl monochloromethane phosphate, dibutyl chlorobenzene phosphonate, and the like. The full esters of pentavalent phosphorus acids such as triphenyl, tricresyl, trilauryl and tristearyl orthophosphates or potassium salt of P S -terpene reaction products or, zinc above, like Zn di(C alkyl)dithiophosphate, e.g., Zn bis(2-ethylhexyl)dithiophosphate, Zn bis(alkylphenyl)- dithiophosphate. Anti-foaming agents such as silicone polymers, e.g., dimethyl silicone polymer, can be used.

The mineral lubricating oils used in compositions of this invention can be obtained from any paraifinic, naphthenic, asphaltic or mixed base crude, and/0r mixtures thereof. The viscosity of these oils may vary over a wide range, such as from 100 SUS at 100 F. to 100 SUS at 210 F. The hydrocarbon oils may be blended with fixed oils such as castor oil, lard oil and the like and/or with synthetic lubricants such as polymerized olefins, copolymers of alkylene glycols and the alkylene oxides, silicone polymers, e.g., dimethyl silicone polymers and the like.

Mineral lubricating oils which are particularly desirable for use in compositions of the invention can be obtained from West Texas Ellenburger crudes, East Texas crudes, Oklahoma crudes, California crudes. A useful solvent refined East Texas mineral lubricating oil had the following properties:

Pour point, F. Viscosity centistokes at 100 F 27 Viscosity index 95 percent wt-.. 4 5.0

PROPERTIES OF COMPOSITION A Method of Determination Property Value Viscosity, SSU at F Viscosity, SSU at 210 F Viscosity, cp. at 0 F., Brookfiel Gravity, API

Flash, 000, F ASTM D-92 420 Fire, COG, F ASTM D-92 455 Pour Point, F ASTM D-97 30 Stable Pour Pt, F MIL-O-2104. 0 TBN- ASTM D-664 9.3 TAN-E ASTM D-664. 2. 6 Initial pH Meter Readlng ASTM D-664 8. 7 Sultated Ash, Percent w-.. ASTM D-874 1. 38 Calcium, percent w X-ray Fluorescence 0. 32 Zinc, percent w-... ....do 0. 096 Phosphorus, percent do 0. 100 Copper Corrosion (3 hr. at 212 F.) ASTM D-l30. 1A Oil Economy Relative to SAE 30 Coon and Leather..- 87.2

ASTM Foaming ASTM D-892 Foam After 5 Min. Agitation Dimethyl silicone polymer having a viscosity of 12,500 centistokes at 25 C. p.p.m 5

Mineral lubricating oil (l0W-30) Balance Composition C:

Copolymer I(A) (2) percent wt 4.0

Succinimide compound I(B) (l do 5.0

Basic Ca petroleum sulfonate (180% basic,

M.W. of petroleum sulfonic acid 450- 550) percent wt 12.0

Zn dioctyl dithiophosphate do 1.0

Dimethyl silicone polymer having a viscosity of 12,500 centistokes at 25 C. p.p.m 5

Mineral lubricating oil (10W-30) Balance Composition D:

Copolymer I(A) (4) percent wt 4.0 Amido-amine derivative I(B) (2 do 5.0 Basic Ca petroleum sulfonate (800% basic,

M.W.-=750) percent wt.-- 12.8 Zn bis(2-ethylhexyl)dithiophosphate do 0.9

Mineral lubricating oil (SAE 30) dimethyl silicone polymer, balance p.p.m 5 Composition A was tested and performed satisfactorily in the MS Sequence Tests I-V (Petroleum, May 1961) whereas corresponding compositions containing only one of the ashless detergents, namely either the compounds of Group I-A of Group I-B failed these tests, particularly the MS Sequence V Test and omitting the sulfonate salt from Composition A resulted in failure in these tests. In all cases where one of the additives was omitted for comparative purposes, the total additive concentration was adjusted to correspond to that of Composition A. Composition A of the present invention also performed well in the CLR-L38 engine test (Petroleum, May 1961) and performed well in the Ford Falcon Rust Test described in Ghannams SAE Paper No. 650,869, presented at Tulsa,

Okla, Nov. 2-4, 1965 meeting and passed the L-l Caterpillar Test (M1L-L-2104A Specification). The results of these tests are shown in Table I.

TABLE I.-ENGINE PERFORMANCE COMPOSITION A MS Sequence I-II-HI (Oldsmobile):

Piston Lacquer I l 9. 8 Over-all Lacquer 9. 8 Over-all Sludge I 9. 8 Lilter Rust I 9. Over-all Rust I 9. 1 Avg. Comb Cam and Litter Wear, In 0. 0024 Max. Comb Cam and Litter Wear, In 0. 0033 Rumble Rating, L1B. 80 MS Sequence IV (Chrysler);

Tappet Ratings 16 No. 1 Cam Lobe Ratings .c 16 No 1 At 192 Hr. At 384 Hr.

MS Sequence V (Lincoln):

Piston Lacquer 9. 6 8. 7 Over-all Lacquer 44. 9 40. 6 Oil Screen Clogging I 10. 0 (O) 9. 9 (I) Over-all Sludge 45. 7 44. Oil Ring Clogging, Percent 0 0 Ring Sticking None None 011 Comsumption at 15. 10

CRC L-38 Test (Labeco):

Cu-Pb Bearing Weight Loss, mg at 40 hrs 16 Cu-Pb Bearing Weight Loss, mg at 100 hrs Besls 10 =perfect.

Basis 50=per!ect.

'lhc test conditions and procedure of this test are published in the Federal Test Metl 0d 7918 (Method No. 3407-1).

Compositions of this invention can be used as turbine oils, gear oils, and in various other applications where detergency and wear inhibition are essential.

I claim as my invention:

1. A mineral lubricating oil composition comprising a major amount of a mineral lubricating oil and (1) a mixture of two dissimilarnitrogen-containing compounds consisting of from 0.1% to about 10% each of (a) a copolymer of C-vinyl pyridine and at least one C alkyl methacrylate ester having a molecular weight range from about 1500 to abou t, 2,000,000 and (b) a succinimide of mono(polyolefin) succin'ic anhydride, said mono(polyolefin) having a molecular weight range of about 800 to about 5,000,000 and a polyalkylene polyamine and (2) 0.1% to about 15% of a basic alkaline earth metal petroleum sulfonate, the acid portion of which has a molecular weight of from about 350 to 1500.

2. A composition as defined in claim 1 which contains from 0.01% to about 2% of a zinc dialkyl dithiophosphate.

3. A composition as defined in claim 1 wherein the copolymer is a copolymer of vinyl pyridine, dissimilar C1248 alkyl methacrylate esters and methyl methacry-late.

4. A composition as defined in claim 1 wherein the c0- polymer is a copolymer of vinyl pyridine and dissimilar C alkyl methacrylate esters.

5. A composition as defined in claim 4 wherein the esters are lauryl methacrylate and stearyl methacrylate, the succinimide is the succinimide of mono(polyisobutylene)succinic anhydride and tetraethylene pentamine, and the sulfonate is a calcium petroleum sulfonate.

6. A composition as defined in claim 4 wherein the sulfonate has a basicity of l-800% and the molecular weight of the acid portion of the salt is 400-800.

7. A composition as defined in claim 4 which contains from 0.01% to about 2% of a zinc dialkyl dith'iophosphate.

8. A composition as defined in claim 7 wherein the dithiophosphate is Zinc bis(2-ethylhexyl)dithiophosphate.

References Cited UNITED STATES PATENTS 2,839,512 6/1958 Barnum et a1. 252-51.5 XR 3,018,247 1/ 1962 Anderson et a1. 3,202,678 8/ 1965 Stuart et al. 25251.5 XR 3,215,632 11/1965 Hughes et al. 3,272,743 9/1966 Nor-man et a1. 252-515 XR PATRICK P. GARVIN, Primary Examiner.

US. Cl. X.R. 252-33.4