CA1114096A

CA1114096A - Succinimide derivatives of a copolymer of ethylene and alpha-olefin

Info

Publication number: CA1114096A
Application number: CA291,329A
Authority: CA
Inventors: James L. Spivack; Nelson W. Fox; James O. Waldbillig; Isaac D. Rubin
Original assignee: Texaco Development Corp
Current assignee: Texaco Development Corp
Priority date: 1976-12-29
Filing date: 1977-11-21
Publication date: 1981-12-08
Also published as: BE862422A; ES465415A1; ZA776945B; FR2376164A1; JPS5384095A; JPS5421392B2; DE2753569A1; GB1578049A

Abstract

Abstract of the Disclosure Succinimide derivatives of copolymers of ethylene and an alpha-olefin, such as ethylene-propylene copolymer, are useful as shear stable viscosity index (VI) improvers and dispersants in lubricating oils. Especially useful is the N-(3-dimethylaminopropyl) succinimide of the copolymer of ethylene and an alpha-olefin, such as ethylene-propylene copolymer. This succinimide is obtained by reacting ethylene-propylene copolymer in a solvent, such as chloro-benzene, with maleic anhydride and a peroxide, such as dicumylperoxide. The resulting succinic anhydride is then reacted with 3-dimethylaminopropylamine to produce the resulting dimethylaminopropyl succinimide derivatives of the ethylene-propylene copolymer. The succinimide derivatives of this invention are advantageously incorporated in minor amounts, such as in the range 0.05-10% by weight based on the overall composition, in lubricating oils, such as petroleum based automotive lubricating oils, to improve the physical properties thereof. For example, the succinimide derivatives of this invention, when added to petroleum based lubricating oils, act as shear stable VI improvers and dispersants.

Description

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This invention relates to novel compounds oradducts, and methods of preparing the same, useful as addi-tives for lubricating oils, particularly petroleum based automotive lubricating oils, to impart shear stability, im-proved viscosity index (VI) and dispersancy in lubricating oil compositions containing the same.
Various compositions and adducts are known and have been employed to improve the viscosity index and dis-persancy in lubricating oil compositions containing the same, see particularly U. S. Patents 3,179,716, 3,316,177, 3,329,658, 3,413,104, 3,449,250, 3,471,458, 3,496,249 and 3,513,095.
Ethylene-propylene copolymers have been employed in lubricating oil compositions as ashless sh~ar stable VI
improvers. These copolymers, however, do not act to any substantial degree as dispersants in lubricating oil com-positions containing the same.
It is an object of this invention to provide compounds or materials, and methods of preparing the same, useful as additives to lubricating oils.
It is another object of this invention to provide compounds and materials useful as shear stable VI improvers and dispersants when incorporated in lubricating oils, particularly petroleum based automotive lubricating oils.

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It is still another object of this inYention to provide derivatives of ethylene-propylene copolymers which are useful as lubricating oil additives.
Yet another object of this invention is to provide a method of preparing compounds or materials useful as shear stable VI improvers and dispersants, when incorporated in lubricating oils, preferably petroleum based automotive lubricating oils.
Also, another object of this invention is to provide petroleum based automotiYe lubricating oils.
Accordingly, one aspect of the invention provides a succinimiae derivative of a copolymer of ethylene and an alpha-olefin wherein the derivative contains from about 0.02% by weight nitrogen to about 1.0~ by weight nitrogen.
Thus, it has been discovered that succinimide derivatives of copolymers of ethylene and an alpha-olefin, such as ethylene-propylene copolymer, are useful as shear stable VI improvers and dispersants in lubricating oils, particularly petroleum based automotive lubricating oils. Especially useful is the N-(3-dimethylaminopropyl) succinimide of the copolymer of ethylene and an alpha-olefin, such as ethylene-propylene copoly-mer. This succinimide is obtained by reacting ethylene-alpha-olefin copolymer, such as ethylene-propylene copolymer, in a solvent with maleic anhydride in the presence of a free radical initiator, such as peroxide, e.g. benzoyl peroxide, dicumul-peroxide and the like.

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4~?!~6 The resulting alkyl succinic anhydride derived by the addition of RH across the double bond of the maleic anhydride, wherein R is an ethylenè-alpha-olefin copolymer radical, such as ethylene-propylene copolymer radical, after addition of a diluent oil and removal of excess maleic anhydride and solvent is converted to the corresponding N-(3-dimethylaminopropyl) succinimide by reaction with 3-dimethylamino-1-propylamine. Upon completion of the reac-tion the excess amine is removed by distillation to yield the resulting succinimide as product.
More particularly, and in accordance with one embodiment of the practices of this invention directed to a method of preparing the succinimide derivatives of the copolymers of ethylene and an alpha-olefin, particularly ethylene-propylene copolymer, a solution containing about 10-40% by weight ethylene-propylene copolymer, particularly a narrow molecular weight distribution amorphous ethylene-propylene copolymer of the type employed as a lubricating oil additive, in a suitable solvent, such as an aromatic solvent, e.g. benzene, chlorobenzene and the like, or in a saturated, aliphatic or cycloaliphatic hydrocarbon solvent, such as cyclohexane, is prepared. The resulting solution is heated to a temperature of about 80-130C. in the presence of added excess maleic anhydride and a small amount of a free radical initiator, such as benzoyl peroxide or dicumylperoxide.
The resulting reaction product is the corresponding alkyl s~ccinic anhydride derived by the addition of RH across the double bond of the maleic anhydride, wherein R is an ethylene-propylene copolymeric radical. There is added to the resulting - . ,, , :
, : .

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reaction mixture a relatively high boiling, substantially inert, diluent oil and the excess maleic anhydride and solvent is removed by vacuum distillation. The remaining polymer succinic anhydride, i.e. the succinic anhydride grafted onto the ethylene-propylene copolymer, is converted to the corresponding N-(3-dimethylaminopropyl) succinimide by heating in the presence of an excess of the correspond-ing polyamlne, viz. 3-dimethylamino-1-propylamine. Upon completion of the reaction the excess amine is removed by distillation and the resulting reaction product fil~ered.
As indicated hereinabove, it is preferred to employ as the ethylene-alpha-olefin copolymer, ethylene-propylene copolymer. In the practices of this invention it is preferred to employ shear stable ethylene-propylene copolymer of the type suitable for incorporation into a lubricating oil as a VI improver. When shear stable ethylene-propylene copolymer is employed in the above-described reaction for the preparation of the succinimide derivative thereof the resulting reaction product of this invention is also shear stable.
In the preparation of the succinimide derivatives of a copolymer of ethylene and an alpha-olefin in accordance with this invention, it has been noted that to obtain optimum dispersant characteri~tics when incorporated in a lubricating oil, the amount of the free radical initiator, e.g. benzoyl peroxide or dicumylperoxide, employed is desirably controlled such that the final polymer succinimide product of this invention contains in the range about 0.15-0.4% by weight nitrogen to achieve optimum results when the resulting . - . . ............... . .
. .

1~ ~4~fi succinimide product is employed as a lubricating oil additive. By way of illustration, there are set forth in accompanying Table I test results with respect to the polymer succinimides prepared in accordance with this invention and having varying nitrogen content. The test results based on the Bench Sludge Test II (BSII) and the Resin Inhibition Test (RIT) indicate the minimum nitrogen content for optimum dispersancy in lubricating oil com-positions:
TABLE I

% (wt.) N in Polymer ~ (wt.) Polymer in Blend BSII RIT
0.09 1.5 2.2 30 0.11 " 1.5 27.5 0.15 " 1.7 29 0.19 " O.g 16 0.29 " o.a 13 0.19 1.0 1.0 50 0.29 " 1.5 47 0.37 " 1.4 RIT and BSII are minimized at 0.19-0.29% in the polymer.

Engine testing of the polymer succinimides of this invention with respect to the dispersancy of the polymer succinimides in lubricating oil compositions has also indicated promising results. Engine testing of multigrade petroleum based automotive lubricating oils containing ethylene-propylene copolymer dimethyl~aminopropylsuccinimide (E-P-DMAPS) as the sole VI improver therein and dispersant gave excellent results. The motor oil compositions or blends in accordance with this invention tested,in addition to . , - . - . . . . .

9fi containing the polymer succinLmides,also contained a pour depressant additive, an overbased calcium sulfonate detergent, a zinc dialkyldithiophosphate oxidation-corrosion inhibitor and an antifoam additive, with the balance of the blend or composition comprising solvent neutral oil.
The effectiveness of the reaction product of the invention was determined by formulating a motor oil composi-tion and t~sting it in the MS-VB Engine Test. The MS-VB
Engine Test was conducted in accordance with the detailed procedures found in ASTM SpecialTechnical Bulletin No. 315-~, "Engine Test Sequences for Evaluating Automatic Lubricants for API Service MS," published by the American Society for Testing Materials, 1916 Race Street, Philadelphia, Pa. 19103.
The MS-VB Engine Test is a low temperature, low speed cycling test designed to determine the oil's ability to pre-vent sludge drop-out and varnish formation in automobile gasoline engines equipped with closed positive crankcase ventil~tion. The test is cyclic in nature alternating between operating and "soak" periods. At test termination engine inspection according to standard procedures is con-ducted in the completely disassembled engine and the results of various lubricants compared accordingly.
The re3ults of these tests are set forth in accompanying Table II.

TABLE II
N in Polymer 0.2 0.3 % Polymer in Blend 1.4 0.9 Vis. Grade lOW-40 lOW-30 Sludge 48.5 47.7 Varnish 39.8 36.7 Piston Skirt Varnish 7.8 7.4 r~
9fi In the practices of this invention for the preparation of the polymer succinimide, various solvents have been disclosed as being useful in the initial reaction wherein the ethylene-alpha-olefin is reacted with maleic anhydride. In connection with this initial reaction it has been mentioned that it is desirable, if not necessary, to employ a large excess of maleic anhydride. An excess of the polyamine,3-dimethylaminopropylamine,is also desirable, if not necessary, in the second stage reaction wherein the polymer succinic anhydride is converted to the corresponding polymer succinimide. Excess maleic anhydride and 3-dimethyl-aminopropylamine is necessary particularly when a saturated cycloaliphatic hydrocarbon, such as cyclohexane, is employed a~ the ~olvent due to significant side reactions between the cyclohexane solvent, maleic anhydride and the polyamine.
It has been determined, however, that the excess of both maleic anhydride and the polyamine, 3-dimethylamino-propylamine,can be significantly reduced when an inert solvent, such as an aromatic solvent, such as an aromatic hydrocarbon, e.g. benzene, or chlorobenzene, is employed ag- solvent instead of a saturated cycloaliphatic hydrocarbon 301vent, such as cyc}ohexane. Indeed, by employing an inert solvent, such as ch}orobenzene or benzene, the amount of 3-dimethylaminopropyl-amine employed in the reaction for the preparation of the polymer succinimide can be substantially reduced, such as to an amount about 10% greater than the stoichiometric amount required for complete reaction with the intermediate succinic anhydride. This reduction in the amount of excess amine required results in the elimination of the amine stripping , ~ .

4~9fi step with consequent lower processing and manufacture costs for the produced additi~e, the polymer succinimide. Also, the final product, the polymer succinimide, contains a lower amount of non-polymer nitrogen-containing or nitrogenous impurities. When the polymer succinimide is prepared employ-ing cyclohexane as the solvent there is present in the result-ing product appreciable or substantial quantities of reaction products derived from side reactions involving the solvent cyclohexane, maleic anhydride and dimethylaminopropylamine.
The resulting side reaction products, when present in the final product, tend to cause excessive corrosion in the lubricating oil blends containing the product polymer succinimide as an additive, based on engine tests, such as tho CLR L-38 bearing corrosion test.
~ Illustrative o~ the advantages of the practices of this invention there is set forth in accompanying Table III
results of tests showing the reduction in amounts of maleic anhydride and 3-dimethylaminopropylamine employed in the presently preferred practices of this invention when an inert solvent, such as an inert aromatic solvent, e.g.
benzene, chlorobenzene and the like, is employed as compared wlth a reactive solvent, such as cyclohexane.

~ 4~ fi TA~LE I I I
- Process Solvents Step Cyclohexane Chlorobenzene Maleic anhydride charge8 g/100 g polymer 2.7 g/100 g polymer Dicumylperoxide charge 0.3 g/100 g polymer 0.43 g/100 g polymer 3-Dimethylamino-propylamine charge 8 g/100 g polymer 1.2 g/100 g palymer Final amine Excess amine No stripping after stripping stripped at 215C./ reaction with amine 20 mm ~g The following is an example of the practices of this invention.
Example 400 grams of ethylene-propylene copolymer ~molecular weight range useful as a lube oil improver) solution contain-ing 31 wt. % copolymer in hexane solution obtained from Copolymer Rubber and Chemical Corp. and 550 grams of chloro-benzene were combined. 330 grams of solvent were removed by distillation from the resulting solution. There resulted a solution containing 20 wt. % ethylene-propylene copolymer in chlorobenzene. Upon cooling to about 130C., 3.35 grams of maleic anhydride and 0.53 gram dicumylperoxide were added to the ~olution. The resulting mixture was heated and maintained at 130C. for 6 hours. Infrared examination of a sample of the polymer separated by precipitation in boiling acetone indicated that upon conversion to the succinimide the neat polymer would contain 0.~0% nitrogen. 1116 grams of a high boiling point inert, neutral diluent hydrocarbon oil were added t~ the resulting solution and the chlorobenzene solvent and exce~s unreacted maleic anhydride were remo~ed by 1~4~fi stripping to a temperature of 180C. at an absolute pressure of 0.08 mm Hg. Thereupon 0.605 gram of 3-dimethyl-amlnopropylamine was added with stirring to 500 grams of the resulting oil solution at a temperature of 125C. The resulting stirred reaction admixture was maintained at 125C.
for 2 hours. The resulting produced polymer succinimide product analyzed .033% nitrogen, the same as the theoretical nitrogen content based on the a unt of amine added. The polymer succinimide product was subjected to comparative automotive engine oil evaluation tests with a polymer succinimide prepared employing cyclohexane as the solvent instead of an inert aromatic solvent, such as benzene. The results of these tests are set forth in accompanying Table IV. The test data presented therein indicate that both productq are equivalent with regard to oil solution properties, shear stability and dispersancy.

TABLE IV
1 Chlorobenzene Cyclohexane Test Data Solvent Product Solvent Product Orig. Vis., 100F., SUS 426 397 210F., SUS 69.0 68.6 FISST ~MS-103, 20 passes) Vis., 210F., SUS 65.2 63.3 Vis., 210F., SUS 3.8 5.3 % Thickening Power Loss, 210F.2 14 20 Pour Pt., F. -45 -45 CCS QF., c.p. 1580 1600 Bench Sludge I 0.4 0.4 II 0.4 0.9 Tested at 1.$ wt. % (neat polymer basis) in above-described diluent oil.
The 210F. viscosity of the base oil (diluent oil) was assumed to be 42.3 SUS for this calculation.

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The polymer succinimide was also prepared employ-ing benzene as the inert aromatic solvent, using also dicumylperoxide as the radical initiator for the addition of the ethylene-propylene copolymer to the maleic anhydxide.
The reaction was carried out at a temperature of about 130-132~C. under autogeneous pressure and the reactant ratios were similar to those set forth hereinabove with respect to the Example wherein chlorobenzene was employed as the solvent.
It was observed that the resulting produced polymer succinimide exhibited oil solution properties, shear stabil-ity and dispersancy at least eq~ivalent to the polymer succinimide prepared with the use of chlorobenzene as the aromatic solvent.
In the preparation of the polymex succinimide in accordance with the practices of this invention it is preferred to employ as the ethylene-alpha-olefin copolymer a copolymer of ethylene-propylene. Desirably, the ethylene-propylene copolymer employed in the preparation of the polymer succinimides derived therefrom in accordance with the practices of this invention is suitable per se as an additive to petroleum based lubricating oils, such as VI improvers therefor. Suitable such ethylene-propylene copolymers are known and would have a molecular weight greater than about 2000, such as a molecular weight in the range 5,000-50,000 and higher. Alpha-olefins other than propylene are also useful in the preparation of ethylene-alpha-olefin polymers as copolymers employed in the practices of this invention.
Such alpha-olefins include bu~ene-l, pentene-l, hexene-l, 4-methyl-pentene-1 and the like. As indicated hereinabove, however, e~hylene-propylene copolymers are preferred with a .

fi molecular make-up such that the ethylene-propylene copolymers contain in the range about 10-90 mol % ethylene and 90-10 mol % propylene, preferably in the range 30-70 mol ~ and 70-30 mol % propylene.
An amorphous ethylene-propylene copolymer which serves as a viscosity index improvement additive in lubricating oils and which is particularly useful in accordance with the practices of this invention may be prepared as described in U.S. Patent 3,522,180. Therein it is disclosed that.the copolymer is prepared in a hydrogen-moderated reaction at moderate temperatures and pressures in the presence of a solvent soluble Ziegler-Natta catalyst.
Gaseous mixtures of propylene and ethylene together with hydrogen are introduced into a reactor containing a solvent which does not deactivate the catalyst, such as carbon tetrachloride, hexane, n-heptane, benzene or cyclohexane.
Reaction temperatures in the range -40F. to about 250F.
and a pressure in the range 0 - 300 psi~ may be satisfactorily employed. The two component Ziegler-Natta catalyst employed comprises as the first component a hydrocarbyl vanadate, a hydrocarboxy vanadyl halide or a vanadyltrihalide and as the second component an alkyl al.uminum halide. Preferred catalyst ~ystems include tri-n-butyl orthovanadate as ~he ~irst component and ethyl aluminum dichloride, diethylaluminum chloride or ethyl aluminum ses~uichloride as the second component.
The above-described Ziegler-Natta catalyst promoted hydrogen moderated polymerization reaction i5 used to produce ethylene-propylene copolymers having an amorphous structure, - .. . . -: . . .

fi by infrared analysis, a propylene content of 20 to 70 mol percent, a number average molecular weight between about 10,000 and about 100,000 and a narrow molecular weight distribution, measured by gel permeation chromo-tography (GPC), of less than about 5. Not only do these copolymers increase the viscosity index of lubricating when added thereto but they exhibit a substantially high resistance to the high shearing forces experienced in lubricating service, which shearing forces often mechanically degrade a long chain polymer.
Although in the practices of this invention it is preferred to employ as the polyamine the compound 3-dimethyl-amino-l-propylamine, other polyamines are useful.
Other useful polyamine~ in accordance with the practices of this invention are identified by any of the following structural formulae:

Rl .: (A) ~N - R3 - NH
: R2 ~ (B) Xl N and : ~ ~R;~NH2 , ~ .
: / 6~
(C~ X2 N - R3 - NH

wherein Rl and R2 are the same or different and are an alkyl radical having 1 to 4 carbon atoms, R3, R6 and R7 are the : : same or different and are a methylene radical having 1 to 4 : carbon atoms, R4 and R5 are the same or different and are a fi methylene or a methine radical having 1 to 4 carbon atoms, Xl is O, N, S, CH2 if R4 and R5 are methylene radicals or CH if R4 and R5 are methine radicals, and X2 is o, N, N-Rl, S or CH2.
Examples of polyamines of formula A are:
3-dimethylamino-1-propylamine; 2-dimethylamino-1-ethylamine, 4-dimethylamino-1-butylamine and 3-dimethyl-1-isopropylamine.
Examples of polyamines of formula B are: 2-aminopyridine and aminopyrazine. Examples of polyamines of formula C are:
N-(3-aminopropyl) morpholine, N-(3-aminopropyl) imidazole and N-(2-aminoethyl) pyrrolidine. Suitable other polyamines are also identified in U.S. Patents 3,329,658 and 3,449,250. In the case of formula B those skilled in the art will appreciate that in some instances one of the bonds on the Xl and/or the N will be a double bond depending on the nature of Xl, R4 and/or R5, viz. if X is N or if R4 and/or R5 are methine radicals.
As indicated hereinabove, the reaction between the ethylene-alpha-olefin copolymers, such as ethylene-propylene copolymer, in the presence of a solvent and in the presence of maleic anhydride and a fxee radical initiator is carried out at a temperature in the range 80-130C., more or less.
Higher or lower temperatures, however, may be employed, if desired. Moreover, free radical initiators other than benzoyl peroxide and dicumylperoxide are also usefully employed. Similarly, the reaction of the polyamine with the resulting produced succinic anhydride may also be carried out at a suitable elevated temperature, such as about 80-130F., more or less, as desired. These reactions are carried out to .. . . . . . . .
.

fi completion. The high boiling point, substantially inert or neutral diluent oil employed in the reactions, particularly to aid in stripping the aromatic solvent, such as chlorobenzene, and any excess maleic anhydride or any remaining polyamine from the reaction mixture, is ad~antageously a petroleum based oil of lubricating oil quality so that the desired product, the polymer succinimide, cantained therein in the resulting reaction product can be readily incorporated as an additive in lubricating oils.
As indicated and demonstrated inert solvents, prefer-ably inert aromatic solvents, are preferred in the preparation of the polymer succinimides. Cyclohexanes and other cycloali-phatic solvents, e.g. cyclopentane and methylcyclohexane are too reactive. The relatively inert solvents are preferred, such as the halogenated hydrocarbons, e.g. halogenated aromatic hydro-carbons, such as chlorobenzene.
It is inaicated hereinabove that the polymer succinimide in accordance with this invention is incorporated in minor amounts as an additi~e in petroleum based automotive lubricating oils, such as an amount in the range 0.05-10% by weight, more or less. Amounts of the polymer succinimide in the range 0.5-

2.5% by weight up to about 3-4% by weight in lubricating oil co~positions ~ould be conYentionally employed to impart shear stability, improved VI and dispersancy to the resulting oil compositions. As indicated above, the polymer succinimide in-corporated in lubricating oils as an additive therein has a %
by weight nitrogen content in the range from about 0.02 to about .0, preferably from about 0.05 to 0.5, more preferably in the range 0.2-0.3. -:

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11 ~4~9fi To facilitate the introduction of the copolymer derivative as an additive into a final lubricating oil blend, the copolymer derivative as an additive may be prepared as a concentrate with a solvent, such as a light lubricating oil having a viscosity of between about 75 and about 300 SUS at 100F.,to form an additive concentrate containing in the range from about 5 to about 3o%rpreferably about 10-15%,by weight of the copolymer derivative additive.

As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations, substitutions and modifications are possible in the practices of this invention without departing from the spirit or scope thereof.

- ~ . . .

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A succinimide derivative of a copolymer of ethylene and an alpha-olefin wherein the derivative contains from about 0.02 by weight nitrogen to about 1.0% by weight nitrogen.

2. A succinimide derivative in accordance with claim 1 wherein the nitrogen content is from 0.05 to 0.5% by weight.

3. A succinimide derivative in accordance with claim 1 wherein said alpha-olefin is propylene.

4. A succinimide derivative in accordance with claim 1 wherein the derivative is the dimethylaminopropyl-succinimide derivative.

5. A succinimide derivative in accordance with claim 1 wherein the derivative is the dimethylaminopropyl-succinimide derivative of ethylene-propylene copolymer.

6. A succinimide derivative in accordance with claim 5 wherein the derivative contains from about 0.2% by weight nitrogen to about 0.3% by weight nitrogen.

7. A succinimide derivative of a copolymer of ethylene and an alpha-olefin wherein the derivative is a polyamine succinimide derivative, the polyamine being selected from the group of polyamines having the formula:

(A) (B) and (C) wherein Rl and R2 are the same or different and are an alkyl radical having 1 to 4 carbon atoms, R3, R6 and R7 are the same or different and are a methylene radical having 1 to 4 carbon atoms, R4 and R5 are the same or different and are a methylene or a methine radical having 1 to 4 carbon atoms, Xl is 0, N, S, CH2 if R4 and R5 are methylene radicals or CH if R4 and R5 are methine radicals and X2 is 0, N, N-Rl, S or CH2 and Rl has the value given above.

8. A lubricating oil composition comprising a minor amount of the succinimide derivative in accordance with claim 3.

9. A lubricating oil composition comprising a minor amount of the succinimide derivative in accordance with claim 4.

10. A lubricating oil composition comprising about 0.05 -10% by weight of the succinimide derivative in accordance with claim 1.

11. A lubricating oil composition comprising about 0.05-10% by weight of the succinimide derivative in accordance with claim 3.

12. A lubricating oil composition comprising about 0.05-10% by weight of the succinimide derivative in accordance with claim 4.

13. A lubricating oil composition comprising about 0.5-2.50% by weight of the succinimide derivative in accordance with claim 5.

14. A lubricating oil composition in accordance with claim 8, 9 or 10 wherein said lubricating oil is a petroleum based lubricating oil.

15. A lubricating oil composition comprising a minor amount of the succinimide derivative in accordance with claim 7.

16. A succinimide derivative of a copolymer of ethylene and an alpha-olefin prepared by reacting said ethylene-alpha-olefin copolymer with maleic anhydride in the presence of a free radical initiator and a solvent for the reaction mixture to produce a resulting alkyl succinic anhydride derivative of said ethylene-alpha-olefin copolymer, adding an inert liquid diluent to the resulting reaction mixture containing said alkyl succinic anhydride derivative, removing remaining maleic anhyd-ride and solvent from the resulting reaction mixture, reacting the alkyl succinic anhydride derivative therein with a polyamine selected from the group of polyamines having the formula:

(A) , (B) and (C) wherein R1 and R2 are the same or different and are an alkyl radical having 1 to 4 carbon atoms, R3, R6 and R7 are the same or different and are a methylene radical having 1 to 4 carbon atoms, R4 and R5 are the same or different and are a methylene or a methine radical having 1 to 4 carbon atoms, X1 is O, N, S, CH2 if R4 and R5 are methylene radicals or CH if R4 and R5 are methine radicals and X2 is 0, N, N-R1, S or CH2 and R1 has the value given above, to produce the corresponding succinimide derivative of said ethylene-alpha-olefin copolymer containing from about 0.02 to about 1.0% by weight nitrogen.

17. A succinimide derivative according to claim 16 wherein the nitrogen content is from about 0.05 to 0.5% by weight.

18. A lubricating oil composition comprising therein the succinimide derivative of claim 16 or 17 in an amount in the range 0.05-10% by weight based on said composition.

19. A method of preparing a succinic derivative of a co-polymer of ethylene and an alpha-olefin comprising reacting said ethylene-alpha-olefin copolymer with maleic anhydride in the presence of a free radical initiator and a solvent at a temper-ature in the range of 80-130°C for the reaction mixture to pro-duce a resulting alkyl succinic anhydride derivative of said ethylene-alpha-olefin copolymer, adding an inert liquid diluent to the resulting reaction mixture containing said alkyl succinic anhydride derivative, removing remaining maleic anhydride and solvent from the resulting reaction mixture and reacting the alkyl succinic anhydride derivative therein with a polyamine selected from the group of polyamines having the formula:

(A) (B) and (C) wherein R1 and R2 are the same or different and are an alkyl radical having 1 to 4 carbon atoms, R3, R6 and R7 are the same or different and are a methylene radical having 1 to 4 carbon atoms, R4 and R5 are the same or different and are a methylene or methine radical having 1 to 4 carbon atoms, Xl is 0, N, S, CH2 if R4 and R5 are methylene radicals or CH if R4 and R5 are methine radicals and X2 is 0, N, N-Rl, S or CH2 and Rl has the value given above to produce the corresponding succinimide de-rivative of said ethylene-alpha-olefin copolymer.

20. A method in accordance with claim 19 wherein said alpha-olefin is propylene.

21. A method in accordance with claim 19 wherein said sol-vent is an aromatic solvent.

22. A method in accordance with claim 19 wherein said sol-vent is benzene.

23. A method in accordance with claim 19 wherein said sol-vent is chlorobenzene.

24. A method in accordance with claim 19 wherein said free radical initiator is benzoyl peroxide.

25. A method in accordance with claim 19 wherein said free radical initiator is peroxide.

26. A method in accordance with claim 19 wherein said free radical initiator is dicumylperoxide.

27. A method in accordance with claim 19 wherein said diluent is a high boiling point petroleum based oil.

28. A method in accordance with claim 19 wherein said poly-amine is 3-dimethylamino-1-propylamine.

29. A method in accordance with claim 19 wherein said poly-amine is 2-aminopyridine.

30. A method in accordance with claim 19 wherein said poly-amine is N-(3-aminopropyl) morpholine.

31. An oil additive concentrate comprising a hydrocarbon solvent and about 5-30% by weight based on the solvent of the succinimide derivative of claim 1.

32. An oil additive concentrate comprising a hydrocarbon solvent of lubricating oil quality and about 5-10% by weight based on the solvent of the succinimide derivative in accordance with claim 7.

33. An oil additive concentrate in accordance with claim 31, wherein the succinimide derivative is present in the range about 10-15% by weight.