CA1271861A - Hydrocarbon compositions containing polyolefin graft polymers - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

There is provided a polymer comprising an oil-soluble, substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer which contains at least one atom of nitrogen, sulfur, or oxygen in a heterocyclic ring structure and a process for preparing the polymer. The polymers are, For example ethylene-propylene copolymers bearing units derived from phenothiazine. The polymers are useful as additives to improve the properties of lubricants.

Description

1~1861 ,_ .
HYDROCARBON COMPOSITIONS CONTAINING
POLYOLEF IN GRAFT POLYMERS
(D#78,317) FIELD OF THE INVENTION

. This invention relates to hydrocarbons including hydrocarbon lubricating oils. More particularly, it relates to hydrocarbons which contain polymers which permit attainment of improved properties.
BACXGROUND OF THE INVENTION

A~ is well known to tho~e skilled in the art, hydrocarbon lubricating oils must be formulated, as by addition of variou~ additives, to $mprove their properties.
In the ca~e of lubricating oils, typified by those employed in railway, automotive, aircraft, 0arine etc. service, ~t ~ found that they become degraded during use due inter alia to ~ormation of ~ludgo which may be g-nerated by deterioration of the oll or by introduction of undesirable components from other source~ including the fuel or the combu~tion air. In ordor to maintain and improve the properties of the lubricating oil, variou~ additives have heretofore been provided; and these have been intonded to improve the viscosity index, dispersancy, oxidativo stability, otc. It i~ an object of this invention to provide an additivo ~y-tem which permit~ attainment of improved hydrocarbon~. Other ob~ect~ will be apparent to those skilled in the art.

'~' 18~1 ,, .

STATEMENT OF THE INVENTION
In accordance with certain of its aspects, this invention is directed to a polymer comprising an oil-soluble, substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer containing at least one atom of nitrogen, sulfur, or oxygen in a heterocyclic ring structure.
According to another aspect of the present invention there is provided the process for preparing a product polymer having an oil-soluble, substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer which con-tains at least one atom of nitrogen, sulfur, or oxygen in a hetero-cyclic ring structure which comprises lntimately admixing in a reaction mixture (i) an oil-soluble, substantially linear, carbon-carbon backbone polymer, (ii) functional monomer containing at least one atom of nitrogen, sulfur, or oxygen in a heterocyclic ring structure and (iii) a free-radical initiator;
maintaining the temperature of the reaction mixture at a temperature at least as high as the decomposition temperature of said initiator thereby effecting decomposition of said initiator and bonding of said functional monomer to said backbone polymer and forming a product polymer having an oil-soluble, substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer which contains at least one atom of nitro-gen, sulfur, or oxygen in a heterocyclic ring structure; and recovering said product polymer having an oil-soluble, ~A
~ - 2 --- 2a - 288-2757 substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer which contains at least one atom of nitrogen, sulfur, or oxygen in a heterocyclic ring structure.
DESCRIPTION OF THE INVENTION
The charge polymer which may be employed in practice of the process of this invention may include an oil-soluble, substan-tially linear, carbon-carbon backbone polymer. Typical carbon-carbon backbone polymers, prepared from monomers bearing an ethyl-enically unsaturated polymerizable double bond, which may be em-ployed include homopolymers or copolymers prepared from monomer con-taining the grouping C=C including C=C-R" C=C
A A
wherein A may be a hydrogen, hydrocarbon such as alkyl, aryl (par-ticularly phenyl) etc., -OOCR typified by acetate or less preferred acyloxy (typified by -OOCR);
halide, etc. R" may be divalent hydrocarbon typified alkyl-ene, alkarylene, cycloalkylene, arylene, etc.
Illustrative of such monomers may be acrylates, methacry-lates, vinyl halides (such as vinyl chloride), styrene, olefins suchas propylene, butylene, etc.; vinyl acetate; dienes such as buta-diene, isoprene, hexadiene, ethylidene norbornene, etc. Homopoly-mers of olefins (such as polypropylene, polybutylene, etc.), dienes ~such as hydrogenated polyisoprene), or copolymers of ethylene, with e.g. butylene and higher olefins, styrene, isoprene and/or butadiene may be employed.

'Al 2a -1~7186~
, The preferred carbon-carbon backbone polymers include those selected from the group consisting of ethylene-propylene copolymers (EPM or EPR) and ethylene-propylene-diene third monomer terpolymers ~EPDM or EPT).

When the charge polymer is an ethylene-propylene copolymer (EPM), it may be formed by copolymerization of ethylene and propylene under known conditions~ preferably Ziegler-Natta reaction conditions. The preferred EPM
copolymers contain units derived from the ethylene in amount of 40-70 mole ~, preferably 50-60 mole %, say 55 mole %r the remainder being derived from propylene.

The molecular weight Mn of the EPM copolymers which lS may be employed may be 10,000-1,000,000, preferably 20,000-200,000 ~ay 140,000. The molecular weight distribution may be character$zed by MW/Mn of les~ than about 15, preferably 1.2-10, ~ay 1.6.

Illu~trative EPM copolymer~ which may be employed in practice of tho proce~ of thi~ invention may be those set forth in the following table, the first listed being preferred:

r t ~ TABLE
A 25 A. The Epsyn brand of EPM marketed by Copolymer Rubber and Chemical Corporation conta$ning 60 mole % of units derived from ethylone and 40 mole % of units derived from propylene, having a mol-cular w-ight Mn of 140,000 and a MW/Mn of 1.6.
B. The Epcar~505 brand of EPM marketed by B. F. Goodrich Co., contalning 50 mole % of units derived from ethylone and 50 mol~ % of unit~ derived from propylene and having a Mn f 25,000 and a polydi~per~ity index of 2.5.
C. The Esprene~ brand of EPR marketed by Sumitomo Chemical Co., containing 5S mole % of units derived from ethylene and 45 mole ~ of units derived from propylene and having a Mn of 25,000 and polydisper~ity index of 2.5t ;~ra~e mq,rk . .

~ 2 ~1 ~61 When the charge polymer is a terpolymer of ethylene-propylene-diene third monomer ~EPT or EPDM), it may be formed by copolymerization of ethylene, propylene, and diene third monomer. The third monomer is commonly a non-conjugated diene typified by dicyclopentadiene; 1,4-hexadiene: or ethylidene norbornene. Polymerization is effected under known conditions generally comparable to those employed in preparing the EPM products. The preferred terpolymers contain units derived from ethylene in amount of 40-70 mole %, preferably 50-65 mole %, ~ay 60 mole ~ and units derived from propylene in amount of 20-60 mole %, preferably 30-50 mole %, say 38 mole % and units derived from diene third monomer in amount of 0.5-15 mole %, preferably 1-10 mole %, say 2 mole ~. The molecul~r weight M~ of the terpolymers may typically be 10,000-1,000,000, preferably 20,000-200,000, say 120,000.
Molecular weight distribution of the useful polymers is preferably narrow vlz a MW/fin of typically less than 15, preferably 1.5-10, ~ay about 2.2.

Illu~trative EPT terpolymer~ which may be employed in practice of the proces~ of thi~ invention may be those set forth in the following table, the first listed being preferred:

TAB~E
A. The Ep~yn 4006 brand of EPT marketed by Copolymer ~ubber and Chemical Corp., containing 58 mole % of units derived from ethylene, 40 mole % of unit~ derived from propylene, and 2 mole ~ of units derived from ethylidene norbornene and having a MW/Mn of 2.2 and a molecular weight Mn of 120,000.

B. The Ortholeum 5655 brand of EPT marketed by DuPont containing 62 mole % of units derived fro~ ethylene, 36 mole S
of units derived from propylene, and 2 mole % of units derived from 1,4-hexadiene and having a ~n f 75,000 and a polydi~persity index MW/Mn of 2.
de rn~rk 4 ~ ~ 7~

C. ~he Ortholeum 2052 brand of EP~ marketed by DuPont con~aining 62 mole % of units derived from ethylene, 36 mole %
of units derived from propylene, and 2 mole ~ of units derived from 1,4-hexadiene and having a Mn of 35~00~ and a polydispersity index MW/Mn of 2.
D. The Royalene~brand of EPT marketed by Uniroyal containing 60 mole % of units derived from ethylene, 37 mole %
of units derived from propylene, and 3 mole % of units derived 1~ from dicyclopentadiene and having a Mn of 100,000 and a polydispersity index MW/Mn of 2.5.
E. The Epsyn 40A brand of EPT marketed by Copolymer Rubber and Chemical Corp. containing 60 mole % of units derived from ethylene, 37 mole ~ of units derived from propylene~ and 3 mole % of un$t~ der$ved from ethylidene norbornene and having a Mn ~ 140,0oo and a polydispersity index MW/Mn of 2.

~ he EPM and EPT polymers may contain minor portions ttypically le~a than about 30~) of other units derived from other copolymerlzable monomers.

It i~ a feature of the process of this invention that there may be bonded onto these oil-soluble, substantially linear, carbon-carbon, backbone polymers, units derived from a functional monomer wh$ch contains at least one of nitrogen, suliur, or oxygen in a heterocyclic ring. When the functional monomer include~ a polymerizable carbon-carbon ethylenically un~aturated double bond, (as is the case for oxample with the reaction prcduct of allyl glycidyl ether and phenothiazine) bonding may be effected as by graft polymerization under graft polymerizat$on condition~. In th$~ instance, the product may be a graft polymer.

When the functional monomer does not contain a polymerizable carbon-carbon ethylenically unsaturated double bond (as is the case for example, with the preferred e rna~fc phenothiazine), then bonding may be effected in the presence of a free-radical initiator catalyst.
It i8 believed that best anti-oxidant activity in the desired polymer product is attained by bonding heterocyclic compounds which exhibit anti-oxidant activity when present in unbonded form. Preferred of these latter is phenothiazine.

The functional monomers which may be employed may be monocyclic, or polycyclict and the nitrogen, sulfur or oxygen may be contained in the same or a different ring. In the preferred embodiment, the functional monomer may be polycyclic and the nitrogen and sulfur may be in the same heterocyclic ring.
The functional monomer can be heterocyclic/aromatic or heterocyclic compound containing ~ulfur, nitrogen or oxygen, or comblnation thereof. The compounds which may be used as the functional monomer includ-s 1) phenothlazine ~nd ring or/and N-~ub~tituted . phenothiasine. Sub~tituent~ may include hydrocarbon radical~ selected from the group con~i~ting of alkyl, alkenyl, cycloalkyl, aryl, alkaryl, or heterocyclic, including ~uch radicals when containing oxygen, nitrogen, ~ulfur, halide or combinations thereof.
$ypically, the ring-~ub~tituted phenothiazine may include alkyl or alkenyl phenothlazine~, alkoxy phenothiazlne~, hydroxy alkyl phenothiazines, aminophenothiazine~, nitrophenothiazine~, 3-formyl-10-alkyl-phenothiaz~ne,

2-amiAo-4-(2-phenthiazinyl) thiazole, alpha (2-phenothiazinyl) thioacetomorpholide, etc Typi¢al N-~ubstituted phenothiazines may include N-vinyl phenothiazine, N-acrylamidomethyl phenothiazine, beta-(N-phenothiazinyl) ethyl vinyl ether, beta-(N-phenothiazinyl) ethyl methacrylate, reaction products of allyl glycidyl ether or glycidyl methacrylate with phenothiazines etc.

2) imidazoles or benzimidazoles, such as 2-mercaptobenzimidazole, 2-mercapto toluimidazole or 2-mercapto-1-urethyl imidazole; etc.

3) thiazoles or benzothiazoles, such as

4-methyl-5-vinylthiazole, 2-amino-4-methylthiazole, 2-mercapto-4-phenylthiazole, 2-mercaptobenzothiazole; etc.

4) triazoles and benzotriazole~, such as 3-mercapto-lH-1,2,4-tr$azole, 3-Amino-S-methylthio-1~-1,2,4-triazole~ etc.

S) thiadlazolos, benzothiadiazoles, thiazolines and benzothiazolines, thiazolidine. They may include 2-mercapto-thiazolinè, 1,2,5-thiadiazoline~ etc.

6) pyrlmldlne,including 2-amino-4-methylpyrimidine, 2-morcaptopyrimidine~ etc.
7) pyridine~, such as 2-mercapto pyridine, 4-mercapto-pyridine, 2-mercaptopyridine-N-oxides etc.

8) piporidine~ and pyrroiidinonos~
9) ox~zole~ and benzoxazolos, such a~
2-morcaptobenzoxazole5 etc.

10~ merc~ptophenols, thiomorpholine, 6-mercapto-purine, 2-thiophenomethyl amino.

Preferred of the functional monomer~ is phenothiazine which is a three-ring compound containing the nitrogen and sulfur in the same ring. It i~ preferred to use one functional monomer although it may be possible to use more than one functional monomer, i.e., to bond them to the polymer either ~imult~n-ously or sequentially, 1 ~ 7~
In practice of the process of this invention, 100 parts of charge EPM or EPT may be added to 100-1000 parts, say 300 parts of diluent-solvent. Typical diluent-solvent may be a hydrocarbon solvent such as n-hexane, n-heptane, tetrahydrofuran, or mineral oil. Preferred solvent may be a commercial hexane containing principally hexane isomers.
Reaction mixture may then be heated to reaction conditions of 60C-180C, preferably 150C-170C, say 155C at 15-300 psig, preferably 180-220 psig, say 200 psig.
Functional monomer, typically phenothiazine, is admitted in amount of 1-40 parts, say 2 parts, as a solution in 2 - 20 part~, ~ay 8 parts of diluent-solvent-typically tetra-hytrofuran (THP). There is also added a solution in hydro-carbon of free radical initiator. Typical free radical initiator~ may include dicumyl peroxide, di-t-butyl peroxide, benzoyl peroxide, di-isopropyl peroxide, azobisi~obutyroni~rile, etc. The ~olvent is preferably the ~ame ~ that in which the EPM or EPT i9 dissolved. The ~nitiator may be atded in amount of 0.2-40 parts, ~ay 1 part in 0.8-120 part~, ~ay 3 parts of solvent hexane.

The reaction is carried out at a temperature at least as high a~ the decomposition temperature of the init$ator, typically 60C or higher.
, IReaction i~ typically carried out at 60C-180C, say 155C and 180-220 psig, say 200 psig during which time bonding of the functional monomer onto the ba~e EPM or EPT polymer occur~. o~ ~-3 1~ 60 Typically the product may by contain 0.1 - 60,~say 3 units derived from functional monomer per 1000 carbon atoms of the charge backbone polymer.
For ease of handling, the polymerization solvent may be exchanged with a heavier solvent such as SUS lOO~oil ~ ~e ~ -8-~ 7 . ~718~i~
~ typified by SN0-100~ Product polymer is typically obtained as a solution of 4-20 parts, say 8.5 parts thereof in 80-96 parts, say 91. 5 parts of solvent.

It is a feature of this invention that the so-prepared polymer may find use in lubricating oils as multifunctional additive (e.g. dispersant, viscasity index $mprovers which provide anti-oxidant properties, etc) when pre~ent in effective amount of 0.2-5 w~, preferably 0.4-3 w~, Jay 0. 9 w%.

Lubricating oils in which the multifunctional additives of this invention may find use may include automotivo, aircraft, marine, railway, etc. oil~; oils used in lS ~park lgnition or compre~ion ignitiont ~ummer or winter oils;
et¢. Typically the lubricating oil~ may be characterized by an ibp of S70F-660P, ~ay 610Ft an ep of 750F-1200F, say 1020Pt and an API gravlty of 25-31, say 29.

A typical lubricating oil in which the polymer of thi~ invention may be present may be a standard SAE 5~l-30 hydrocarbon motor oil formulation having the following compositions ~ l-r~e ~

_g_ 1;~71~
TABLE

Base Oil 82

5 -Viscosity Index Improver 9 (10 w% ethylene-propylene copolymer in 90~ inert oil) -Standard Additive Package: 9 Polyisobutenyl (Mn 1290) succinimide ~dispersant);
calcium sulfonate (detergent);
Zinc dithiopho~phate ~anti-wear);
dl-nonyl diphenyl amine ~anti-oxidant);
4,4'-methylene-bis (2,6-di-t-butyl phenol) lS (antioxidant);

Uoe of the additive of thiR invention makes it pos~ible to readily lnorea~e the viscosity index by 25-40 units, say 35 units and to obtain improved ratings on the tests mea~uring the disperJancy of the ~y~tem. The viscosity index i~ determined by A8TM Te~t D-445.

Practice of the process of this invention will be apparent to tho~e skilled in the art from the following examples wher-in, as elsewhere in this specification, all parts are part~ by weight unle~ otherwise ~et forth. Control examples are d-~ignated by an ast-risk.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLE I

In thi~ example which de~cribos the best mode presently known, the charge EPM polymer i~ the Epsyn brand of polymer of molecular weight Mn f 140,000, of MW/Mn ratio of 1.6, and containing 60 mole % of units derived from ethylene and 40 mole ~ of unit~ derived from propylene. 100 parts of 1~71~
\
this polymer are dissolved in 300 parts of commercial hexane and added to a reaction vessel.

The reaction vessel is purged with nitrogen and heated to 155C at 200 psig. Phenothiazine (2 parts) dissolved in 8 parts of tetrahydrofuran is added followed by a solution of 1 part of dicumyl peroxide initiator in 3 parts of commercial hexane. The mixture is stirred at 155C and 200 p~ig for 1 hour. Solvent Neutral Oil SNO-100 (SUS 100) ~1076 parts) i~ then added~ and the hexane is distilled off at 90-120C. The re~ulting solution contains about 8.s w~
polymer, The proce~ of Example I may be carried out using the following charge polymer~ of Examples II - IV:
EXAMPLE II

The Epsyn 4006 brand of EPT marketed by Copolymer containing 58 mole % of units derived from ethylene, 40 mole 4 of unit~ derived from propylene, and 2 mole % of unit~ deriv-d from ethylidene norbornene and having a ~ln f 120,000 and a MW/Mn of 2.2.

EXAMPLE III
The Ortholeum 2052 brand of EPT marketed by DuPont containing 62 mole % of units derived from ethylene, 36 mole ~ of unitJ derived from propylene, and 2 mole % of units derived from 1,4-hexadiene and having a MW/Mn of 2 and a mol~cul~r weight Mn f 75~000.

1~:71861 EXAMPLE IV
The Royalene brand of EPT marketed by Uniroyal contain-ing 60 mole % of units derived from ethylene, 37 mole ~ of units derived from propylene, and 3 mole ~ of units derived from di-cyclopentadiene and having a Mn of lO0,000 and a MW/Mn of 2.5.
_XAMPLE V*
In this control Example, 100 parts of the same charge EPM copolymer as used in Example I is mixed with 1076 parts of SN0-lO0 oil at 80-90C and the mixture i8 agitated under nitrogen for 24 hours. There is then added phenothiazine (2 parts) dis-eolved in 8 parts of tetrahydrofuran; and the mixture is maintain-ed at 80C-90C for one hour.
EXAMPLE VI*
In this control Example, the procedure of Example V* is followed except that the phenothiazine in tetrahydrofuran is not added.
EXAMPLE VII
In this experimental example, the procedure of Example I
iB followed except that the polymer i9 EPDM containing 64 mole %
of units derived from ethylene, 35 mole ~ of units derived from propylene, and l mole % of units derived from 1,4-hexadiene and having a Mn of 75,000 and a MW/Mn of 2.

X

r 1~ 71~

EXAMPLE VIII

In this control example, the procedure of Example VI
i8 followed except that the polymer employed is the same polymer as employed in Example VII.

EXAMPLE IX
In this experimental example, the procedure of Example I is followed except that the functional monomer is ~inJtead of phenothiazine) a monomer prepared by heating for ono hour a 100C-120C, ~ mixture of eguimolar amounts of allyl glycidyl ether and phenothiazine.

Tho products of Examples I and V-VIII are subjected to tho Bonch Oxidatlon Te~t ~BOT) to determine whether the ~dditive is a ~atisfactory anti-oxidant. In the test, an 8.5w~
~olution o~ the te~t polymer in SNO-100 oil is diluted with ~NO-130 oil to give a 1.5w~ ~olution of the test polymer. This solution i8 heated with stirring and air agitation.
8amples sre withdrawn periodically and analyzed by ~i) Differential Infrared Absorption (DIR) to observe changes in the inten~ity of th- carbonyl vibration band at 1710 cm 1, (ii) the Vl~ual Clarity Te~t and (iii) the Lumetron Turbidity Test.

The Oxidation Index is reported as the Carbonyl Group Ab~orbance in the Diferential Infrared Spectra after 144 hours o~ oxid~tion. The Oxidation Index may range from 0 up to 100 and a low rating is desired. The re w lts below 4 are con~idered excellent.

The cl~ity of the products of Example I and V-IX
i~ al~o reported visuslly and by the Lumetron Turbidity Test after 144 hours of oxidation. In the Lumetron Turbidity Test, the turbidity of tho product is determined by a Lumetron ~ '~ 7~ 8 Photoelectric Colorimeter.

The Lumetron Turbidity is reported on a scale of S 0-100. A rating of below about 20 is satisfactory; higher ratings are less satisfactory.

The product of Example I is also subjected to the standard CEC MWM-B Diesel Engine Test (DIN 51361 Parts I, II, and IV).

~ 71 ~61 The following table notes the results - including a series of tests on a typical commercial formulation.

TA~LE
-ClaritY at 144 hours Oxidation LumetronMWM-B
Example Index VisualTurbidity Merits Commercial 9.5 Turbid 60 53 I 1.1 Clear 14 67 1,0 V 1.8 Turbid 100 V~ 15 Turbid 100 VII 1.3 Clear 12 VIII 16 Turb~d 100 $X 2.1 Clear 16 lS
From the abovo Table, it is apparent that the experimental ~xample~ I, VII, and IX are characterized by a de~irably low Oxidatlon Index ~i.e. freedom from oxidation), by a vi~ually cl-ar readinq, and by a deoirably low Lumetron Turbidity rating. Control Exampl-~ VI and VIII which fall out~ido the ~cope of this invention aro characterized by unde~irably higher Oxidation Indices, by a visually turbid reading, and by unde~irably high Lumetron Turbidity ratings.
Control Example V iJ un~ati~factory by the latter two criteria.

Experimental Example I ~howod better deposit protectlon (higher merit~ in the MMM-~ test) than currently manufactured commercial di~per~ant olefin copolymer (DOCP) v~co~ity ind-x improver.

-i -15-~718~
EXAMPLES X-XI

In Example X, the product of Example I, containing the functionalized EPM, is tested as a viscosity index improver in a conventional mineral lubricating oil at concentration of 11 5 w% (corresponding to 1 w% of grafted EPt~); and in control Example XI , a formulation containing 11 5 w% of commercial non-dispersant VI improver (corresponding to 1 w~ active ingredient) in the same system i~ tested TABLE
Example Kinematic Visco~ity_(cSt) Thickening TP/W%
40C 100C Power el00C Polvmer X~ 62 5 10 53 5 60 0 66 Thickening Pow r (TP) is calculated by subtracting the vi~co~ity o~ the ~ase ~lond (4 8 cSt e 100C) from that of the te~t ~pecimen measured at 100C This number (e g 9,89-4,8 or 5 09 in the ca~e of Example X) is the Thickening Power at 100C

Although this invontion ha~ been illustrated by ref-r-nce to ~peciflc embodiments, it will be apparent to those sklll-d in tho art that variou~ changes and modifications may be made which cloarly fall within the w Ope of thi~ invention

Claims (26)

WHAT IS CLAIMED IS:

1. A polymer comprising an oil-soluble, substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer which contains at least one atom of nitrogen, sulfur, or oxygen in a heterocyclic ring structure.

2. A polymer comprising an oil-soluble, substantially linear, carbon-carbon backbone polymer as claimed in claim 1 wherein said functional monomer contain one atom of nitrogen in a heterocyclic ring structure.

3. A polymer comprising an oil-soluble, substantially linear, carbon-carbon backbone polymer as claimed in claim 1 wherein said functional monomer contains one atom of nitrogen and one atom of sulfur in a heterocyclic ring structure.

4. A polymer as claimed in claim 1 wherein the molecular weight ?n of said polymer is 10,000 - 1,000,000.

5. A polymer as claimed in claim 1 wherein the molecular weight ?n of said polymer is 20,000 - 200,000.

6. A polymer as claimed in claim 1 wherein said functional monomer is phenothiazine.

7. A polymer as claimed in claim 1 wherein said functional monomer is the reaction product of phenothiazine and allyl glycidyl ether.

8. A polymer as claimed in claim 1 wherein said polymer contains, per 1000 carbon atoms of polymer backbone, 0.3-60 units derived from said functional monomer.

9. A polymer comprising an oil-soluble, substantially linear, carbon-carbon backbone polymer of molecular weight ?n of 20,000 - 200,000 bearing units therein derived from phenothiazine in amount, per 1000 carbon atoms of polymer backbone, of 0 1-60 units derived from phenothiazine.

10. A polymer as claimed in claim 9 wherein said backbone polymer is a copolymer of ethylene-propylene-diene third monomer.

11. The process for preparing a product polymer having an oil-soluble, substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer which contains at least one atom of nitrogen, sulfur, or oxygen in a heterocyclic ring structure which comprises intimately admixing in a reaction mixture (i) an oil-soluble, substantially linear, carbon-carbon backbone polymer, (ii) functional monomer containing at least one atom of nitrogen, sulfur, or oxygen in a heterocyclic ring structure and (ii) a free-radical initiators maintaining the temperature of the reaction mixture at a temperature at least as high as the decomposition temperature of said initiator thereby effecting decomposition of said initiator and bonding of said functional monomer to said backbone polymer and forming a product polymer having an oil-soluble, substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer which contains at least one atom of nitrogen, sulfur, or oxygen in a heterocyclic ring structure; and recovering said product polymer having an oil-soluble, substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer which contains at least one atoms of nitrogen, sulfur, or oxygen in a heterocyclic ring structure.

12. The process for preparing a product polymer as claimed in claim 11 wherein said backbone polymer is a copolymer of ethylene-propylene or a terpolymer of ethylene-propylene-diene third monomer.

13. The process for preparing a product polymer as claimed in claim 11 wherein the molecular weight ?n of said backbone polymer is 10,000 - 1,000,000.

14. The process for preparing a product polymer as claimed in claim 11 wherein the molecular weight fin of said backbone polymer is 20,000 - 200,000.

15. The process for preparing a product polymer as claimed in claim 11 wherein said functional monomer is phenothiazine

16. The process for preparing a product polymer as claimed in claim 11 wherein said functional monomer is the reaction product of allyl glycidyl ether and phenothiazine

17. The process for preparing a product polymer as claimed in claim 11 wherein said product polymer contains, per 1000 carbon atoms of polymer backbone, 0.3-60 units derived from said functional monomer

18. The process for preparing a product polymer having an oil-soluble, substantially linear, carbon-carbon backbone polymer having units thereon derived from phenothiazine which comprises intimately admixing in a reaction mixture (i) an oil-soluble, substantially linear, carbon-carbon backbone polymer of molecular weight ?n of 10,000 - 1,000,000, derived from ethylene-propylene or ethylene-propylene-diene third monomer backbone polymer, (ii) phenothiazine and (iii) a free-radical initiator;
maintaining the temperature of said reaction mixture at 60° C-1800° C thereby effecting bonding of said phenothazine and said backbone polymer to form a product polymer having an oil-soluble, substantially linear, carbon-carbon backbone polymer having units thereon derived from phenothiazine; and recovering said product polymer having an oil-soluble, substantially linear, carbon-carbon backbone polymer having units thereon derived from phenothiazine

19. A lubricating oil composition containing a major portion of a lubricating oil and a minor effective amount of a polymer comprising an oil-soluble, substantially linear, carbon-carbon backbone polymer bearing units thereon derived from a functional monomer containing at least one atom of nitrogen, sulfur, or oxygen in a heterocyclic ring structure.

20. A lubricating oil composition as claimed in claim 19 wherein said backbone polymer is a copolymer of ethylene-propylene or of ethylene-propylene diene third monomer.

21. A lubricating oil composition as claimed in claim 19 wherein the molecular weight ?n of said backbone polymer is 10,000 - 1,000,000.

22. A lubricating oil composition as claimed in claim 19 wherein said molecular weight ?n of said backbone polymer is 20,000 - 200,000.

23. A lubricating oil composition as claimed in claim 19 wherein said functional monomer is phenothiazine.

24. A lubricating oil composition as claimed in claim 22 wherein said functional monomer is the reaction product of phenothiazine and allyl glycidyl ether.

25. A lubricating oil composition as claimed in claim 19 wherein said polymer contains, per 1000 carbon atoms of backbone polymer, 0.1 - 60 units of functional monomer.

26. A lubricating oil composition comprising a major portion of a lubricating oil and a minor effective amount of 0.2-5 w% of a polymer comprising an oil-soluble, substantially linear, carbon-carbon backbone polymer of molecular weight ?n of 10,000 - 1,000,000, derived from ethylene-propylene or ethylene-propylene-diene third monomer backbone polymers, said backbone polymer having bonded thereto units derived from phenothiazine.