CA1099841A - Ethylene copolymer/ethylenically unsaturated nitrogen reactant adducts useful as multifunctional v.i. improvers for lubricating oils - Google Patents

Abstract

ABSTRACT OF DISCLOSURE

An ene adduct and adduct derivatives of a C3-C24 ethylenically unsaturated nitrogen-containing reactant, e.g. acrylonitrile, and a copolymer of ethylene, at least one C3 to C50 alpha-monoolefin and at least one non-conjugated diene, said adduct containing from about 0.005 to 7% by weight nitrogen and having a number average molecular weight of from about 1000 to 500,00, in oil-soluble form have utility as a multi-functional V.I. improver for lubricating oils.

Description

1 This invention relates to nitrogen~containing

2 polymerîc adducts and to ~ubricatlng oil composi~ions con-

3 taining said adducts as multifunctional additives,

4 especially ~hose adducts derived from copolymers which have a substantially saturated hydrocarbon backbone-chain with 6 side-chain unsaturation and unsatura~edg polar, nitrogen-7 containing organic reactants~
8 The literature abounds with discussions of multi-9 functional viscosity index (V.I.) improvers containing nitrogen to enhance their dispersant activity~ Included 11 therein are polymeric nitrile-containing subs~ances as 12 lubricating oil additives with de~ergent-dispersant and 13 ot~er properties.
14 The incorpora~ion of any ni~rlle moiety in said V.I.-improving polymeric substances according to the prior 16 art was generally by conventional means including copolymer-17 ization of one or more olefins with a nitrile containing 18 monomer (U~S. Patent 3,445,387), ree radical gxafting as 19 by hydroperoxida~ion of an ethylene copolymer directly with a polar vinylidene monomer~ such as acrylonitrile (see 21 U.S. Patent 3J 404,09l), and reacting a nitrile~containing 22 compound with a reactive copolymer such as is obtained from 23 a ~ree radical grafting of maleic anhydride to polyiso-24 butylene (see U.S, Patent 3g448J049~
2s These processes which utilize ~ree radical~, 26 either generated by shearing stresses during masticatlon 27 or by hea~ing organic compounds, such as peroxldes~ to 28 prepare a polymeric adduct have certain disadvantages~
~ including irreversible crossllnking o~ the copolymer and homopolymerization of monomeric components. One o~ su~h 31 disadvantages ls shown in U.S. Patent No. 3,236J917 which 32 discloses adducts prepared by heating a mixture of ethylene/
, ~7 ~ ~9 ~

1 propylene ~opolymer and maleic anhydride in the presence 2 of an organic peroxide which ini~iates the addition 3 reactlon by the generation of free radicals. UnfortunatelyJ
4 among other reactions generated therein, a molecule of s maleic anhydride grafts into two copolymer chains thereby 6 irreversibly crosslinking the copolymer and markedly 7 decreasing its solubility in oil. One approach to 8 overcoming this disadvantage is shown in U.S. Patent 9 3,3789492 which teaches lubricating oil compositions w~lch comprise a major proportion o a lubricating oil and a 11 minor, but V.I. improving proportion of a reaction product 12 of an unsaturated hydrocarbon polymeric compound, e.g.
13 polybutadiene, with an unsaturated, polar~ nitxogen-14 containing organic compound, e.g. acrylonitrila, which is grafted onto said polymeric co~pound by a free radical 16 initiated reaction.
17 Another approach to preparing an oil-soluble 18 nitrogeneous ashless dispersant involves reacting a 19 polyolefin with acrylonitrile and chlorine or bromine at elevated temperatures9 followed by reacting the product with 21 enough aliphatic amine to replace the halogen at~ms and 22 thereafter with maleic anhydride and finally with an 23 aliphatic amine or polyamine (se~ U.S. Patent 3,9l4,203~.
24 It has now been found that multifunctional V I.
improvers of enhanced dispersancy can be obtained by 26 thermally incorporating a C3~C2~ ethylenically unsatura~ed 27 nitrogen-contalning reactant onto a carbon~to-carbon double 28 bond which is pendant ~rom a substantially saturated ~ hydrocarbon polymer backbone by a thermal ("ene") addi~ion.
The ene reaction~ as report~d in the li~erature, 31 has ~een defined as the indirec~ substituting addi~ion o~
32 ~ compound with a double bond (enophile) to an olefin with l an allylic hydrogen (ene) and involves allylic shift of 2 one double bond, tr~nsfer of ~he allylic hydrogen to the 3 enophile and bonding between the ~wo unsaturated termini.
4 (See Hofman, "The Ene Reaction", Angew. Chemie,Interna-tional Edition,Vol. 8~ 556~578 (1969)).
6 The ene adducts are readily distinguished from 7 other functionalized adducts, such as epoxide functionalized 8 adducts reported in UOS. Patent 3~84~,010, since ene 9 adducts maintain a site of ole~inic unsatura~ion and are characterized by an olefîn to olefin i.e. car~on to carbon 11 bond ~ormation.
12 In their broadest form, this novel class of 13 products of the invention can be characterized as ene 14 adducts of a C3-C24 ethylenically unsaturated nitrogen-containing reactant and a copolymer of ethyleneJ at least 16 one C3-C50 alpha-monoolefin and a~ least one C5 C24 non~
17 conjuga~ed diene, said adduct containing from about 0.005 18 to about 7% by weight nitrogen and having a number average 19 molecular weight (Mn) of from abo~t 1,000 to abou~ 500~000.
Preferably, the adducts contain about 0.005 to about 0.8 2l wt.% nitrogen, more pre~erably 0.02 to 0.5 wto% nitrogen.
22 The molecular weLght (Mn)is preferably ~rom about 1,000 to 23 10,000 or dispersant appli~ations and from about lO,000 to 24 200,000 for V.I. improver-dispersan~ applications. The 2s adducts of ~he invention are 9ui~ed fox lubrlcating oil 26 applications when they posse 8 su~icien~ oil-solubility, 27 i.e. at least about 10 wt.% at 20C. based on the total 28 weight o the lubrlcating oil composition; howe~er, when 29 oil~nsolubleJ these adducts o~ the i~vention have application as oil-resistant rubbers ln seals and gaske~s, 31 such as or a~tomobile sutomatic transmissions, 32 The lubricati~g oil compositions of ~his ~ ~ 9 ~ ~ ~

1 invention comprise a major proportion of a lubricating oil 2 and a minor, but V.I.-lmproving proportion of said adducts.
3 Copolymers of ethylene, at least one C3 to C50 4 alpha-monoolefin, and at leas~ one non~conju~atad diene prepared by means o~ Ziegler-Natta catalysis are well 6 known. These copolymers have a subs~an~ially saturated 7 hydrocarbon backbone chain which cau~es ~he copolymer to 8 be relatively inert to ozone attack and oxidative 9 degradation and side chain unsaturation available for adduct formation by means of the ene addition.
11 Propylene is normal~y selected as the C3-C50 12 alpha-monoolefin in preparing such copolymers because of 13 its availability and for reasons of economics. Other 14 alpha-monoolefins, such as l-butene, l~pentene, l-hexene, l-decene, l-dodecene, and l hexade~ene, can be selected 16 in place of or in addition to propylene in preparing such 17 copolymars. The term ~PDM as used herein refers to the 18 copolymers of ethylene, propylene, and at l~ast one 19 non-conjugated diene useful for this invention; sald diene is usualIy a Cs-C24~ preferably C6-Cl4, diene.
21 An especially preferred class of EPDM is that in 22 which the non-conjuga~ed d~ene is monoreactive. Monoreac-23 tive non-conjugated dienes have one double bond which 24 readily en~ers the copolymerization reaction with the ethylene and ~he C3-Cso alpha-monoole~in, and a second 26 double bond w~ich does not, to any appreciable extent, i.e.
27 less than about 20 percent, enter the copolymerization 28 reaction. Copolymers of ~his clas~ have maximum pendant group unsaturation for a given diene contentJ which ~ unsa~uration is a~ailable for adduct formation.
31 Monoreactive non-conjugat0d dienes which can be 32 selected for preparing the pre~erred clas~ of oil-soluble 1 EPDM copolymers include linear aliphatic dienes of at 2 least six carbon atoms which have one terminal double bond 3 and one internal double bond~ e.g. 1,4-hexadlene, and 4 cyclic dienes wherein one or both of the carbon-to-carbon double bonds are part of a carbocyclic ring, e.g. 5-6 ethylidene-2-norbornene.
7 Other suitable non-conjugated dienes include 8 straight chain acyclic dienes such as 1,5~heptadlene, 9 1,6-octadlene; branched chain acyclic dienes such as

5 methyl-1~ 4-hexadiene3 single ring alicyclic dienes such 11 as lJ4-cyclohexadiene~ multi-single ring alicyclic dienes 12 and multi~ring alicyclic fused and bridged ring dienes 13 such as dicyclopentadiene~ 5-methylene-2-norbornene, 14 5-methylene-6-methyl-2-norbornene, 5-methylene-6J6 dimethyl-2-norbornene~ 5-propenyl-2-norborneneJ 5-(3-cyclo-16 pentenyl)-2-norbornene and 5-cyclohexylidene-2-norbornene.
17 The copolymers which are to be reac~ed with the 18 ethylenically unsaturated nitrogen-containing reactant, 19 e.g~ the nitrile monomers3 to form the ene adducts, ~ comprise about 30 to 85 mole % ethylene; about 15 to 70 21 mole % o the C3-Cso, e-g- C3 to ~189 optimally C3 ~o 22 Cg, alpha-monoolefin, and about 0.5 to 20 mole % of the 23 diene. Preerred are pol~mers consisting of ethylene, 24 said higher alpha-olein and said diene containing 40 ~o 70 mol % ethylene and 2 to 15 mol % dienes, ~he 26 remainder being propylene. On a welght basis usually at 27 least 2 or 3 w~.% o~ the polymer will be the non-conjugated 28 diene. Mixtures of monoolefins and/or mixtures of non-~ conjugated dienes can be used.
In general, the catalyst compositions used to 31 prepare these copolymers comprise a pri~c~pal cataly~t 32 cons~sting of a transition metal compound from Groups IVb, ~U~4~

1 Vb and VIb of the Periodic Table of the Elements, 2 particularly compounds o~ titanium and vanadium, e.g.
3 VOCl3, and organometallic reducing compounds from 4 Groups IIa, IIb and IIIa, particularly organo-aluminum ompounds~ e-g- (C2~s)3 A12C13. which are designa~ed as cocatalysts. Examples of suitable ca~alysts and preferred 7 reaction conditions are shown in U.S, Patent 3,551,336.
8 The copolymers may have molecular weights (Mn) 9 of about 1,000 to 500,000; preferably 10,000 to 200,000;
and usually abou~ 20,000 to 100,000. In general~ polymers 11 having a narrow range of mole ular weight, as determined 12 by the ratio o~ weight average molecular weight (Mw) to 13 number average molecular weight (Mn) are preferred.
14 Polymers having a MW/Mh of less than 10, pre~erably less lS than 7, and most pre~erably 4 or less are most desirable.
16 Polymers in this range may be obtained by a choice of 17 s~nthesis conditions, such as choice of principal catalyst 8 and ~ocatalyst com~ination~ addition of hydrogen during 19 the synthesis, or post synthesis treatment~ such as extrusion at elevated temperatures and under high shear 21 through small orifices. While these copolymers are 22 essentially amorphous in character by superficial 23 inspection, they may contain up to 25 pereent by weight of 24 crystalline segments as determined by X-ray or dlf~eren-tial scanning calor-lmetry.
26 Broadly, ~he e~hylenically unsaturated nitrogen-27 con~aining reac~an~s contemplat0d by ~he present invention 28 generally consist o carbon, hydrogen and nitrogen and 29 may al50 contain oxygen. These nitrogen-containing reactants may also contain substituent groups suc~ as 31 keto, hydroxylJ ether, mercapto~ sulfide, sulfoxide, 32 sulfonyl~ etc. Generally, these nitrogen-containing ~g8~

1 reactants will contain about 3 ~o 24 carbon a~ms and 2 must contain an electron withdrawing group in such 3 proximity to ~he unsaturation whereby the olefinic bond 4 is activated by at least one electron-attracting group.
S The terms "electron-withdrawing" and "electron-attracting"

6 are used as synonyms herein.

7 Thus, in its broadest fonm, the ethylenically

8 unsaturated nitrogen-containing reactant may be selected

9 from a broad group of tetra-substituted ole~ins. Thus, the reactant can be represented by the ge~eral formula:
11 ~ ~l \ / R ~
12 ( / C = C \ ) Nx 13 ~ R2 R4 ~
14 wherein Rl~ R2~ R3 and R4 are independently selected from one or more electron~attracting groupsJ N represents a 16 nitrogen moiety and x ranges from l to 50. Thus, the 17 only restriction placed upon said groups is that the final 18 reactant contains at least one nitrogen atom. In this 19 manner, the ethylenically unsaturated nitrogen-containîng reactant may be represented by the above general formula 21 where R13 R2, R3 and R4 are independen~ly selected from 22 ~he groups consisting of hydrogen and Cl to C30 straight 23 and branched chain alkyl, arylalkyl, cycloalkyl, alkenyl, 24 arylalkenyl and cycloalkenyl moieties and/or one or more reactive group~ of the class consisting of alkyl 26 unsaturation, cyano, carboxyl~ epoxide, thiol3 carbonyl, 27 isocyanate, thionyl, amido, hydroxyJ iminoJ acylhalide, 28 halo, lactamo~ lactono, dicarboxylic acid anhydride, 29 thioIic anhydride, thionic anhydride~ dithionlc anhydride~
disubstituted amino, trisubstituted amino, ureido, isourea 31 and dicarboxylamic acid anhydride or oneohalf o~ cyclic 32 dicarboxylic acid an~ydrides a in malelc anhydride or 9 ~

1 one-hal of cyclic thionic anhydride or one-half of 2 cyclic dithionic anhydride or one-hal of cyclic dicar-3 boxylic amic acid anhydride or one-half of cyclic N
4 Cl-lg hydrocarbyl imides suçh as N-dodecylmaleimide and pyrrolidine.
6 The term "NX", as used in ~he above formula, is 7 designed to indicate that the nitrogen-containing group 8 or moiety is present in one or more of the "R" groups and/or 9 several nitrogen-containing groups may be present in the same "R" group; however, there must be at least one N-11 containing moiety in the reactant with a preferred range 12 of X of 1 to 10, more preferably 1 to S. Thus, in acrylo-13 nitrile, Rl~ R2 and R3 are hydrogen atoms while X~l;
14 that is, R4 is a "CN" group. Examples of these groups include alpha-chloroacrylonitrile; N,N-dibutyl acrylamide;
16 acrylamide; N-t-octyl acrylamide; thioacrylamide; N-n-17 octylacrylamide; N~acryloyl-morphiline, thioacrylamide;
18 ammonium acrylate; vinylidene cyanide; N,N-dimethylamino 19 ethyl methacrylate; t-dodecylaminoethyl acrylate;
N-octyl maleimide; N-vinyl-S-methyl-2-pyrrolidone;
21 pyrrolidinyloctyl vinyl sul~ide; N-vinylethyleneurea;
22 N-vinyl-1,2-propyleneurea; N-vinylcarbazole; butanamido-23 decyl vinyl ether; ace~amidooctadecyl vinyl ether;
24 ureidoethyl vinyl ether; and 2-vinyl-5-methylpyridine; and tetracyanoethylene.
26 One preerred type of nitrogen-containing 27 reactants, i.e. unsaturated~ polar, nitrogen-con~aining 28 enophiles~ to which the present invention is directed, ~ has the ormula H R' O R"
"
31 RC - C - C - X - tCH2~n ~ N \
3? R " ' 84~L

1 wherein X is oxygen~ or an NR group, n is a whole number 2 from 1 to 5~ preferably 2 to 5, R and R' are either 3 ~ydrogen or a Cl to C4 ~lkyl group~ R" and R " ' are each 4 Cl to C12, preferably Cl to C4, hydrocarbyl groups, e.g.
alkyl groups. The various R groups may be the same or 6 different.
7 Specific examples of compounds which may be 8 employed as the preferred nitrogen-con~aining enophlles 9 include dimethylaminoethyl methacrylate, diethylamino~
propyl methacrylamide~ di(isobutyl) aminoe~hyl methacryla~e, 11 methylisobutyl-aminopropyl acrylate, 4-vinyl pyridineJ
12 ethylene imine, N-vinyl pyrrolidone etc. Mixtures of 13 various nitrogen-containing enophiles may be used. Another 14 preferred type of nitrogen-containing enophiles, i e.
unsaturated, polar, ni~rogen-containing organic compounds, 16 to w~ich the present invention is particularly directed 17 are nitriles having the formula:

19 R-CH=C-CN or CH2=CH-CH-CN
wherein ~ is a hydrogen atom or a lower alkyl, e.g~, 2~ methyl, ethyl, and the like, X is a hydrogen atomJ a 22 halogen atom, a cyano or a lower alkyl group9 e.g. methyl, 23 ethyl, propyl, butyl and the like~ Examples of nitrile 24 monomers which are contemplated by the aforedescribed ~tructure include, acrylonitrileg methàcrylonitrile, alpha-26 bromoacrylonitrile~ alpha-chloroacryloni~rile, vinylidene 27 cyanide, allyl cyanide, and the like.
28 The thermal ene addition o the ethylenically 29 unsaturated nitrogen-containing reacbant to the saturated ethylene backbone copolymer having pendant group carbon-to-31 carbon unsaturation i8 theorized to occur by the ~ollowing 32 reaction (using a copolymer o~ ethylene, propylene and

- 10 -1 5-ethylidene-2-norbornene and acrylonitrile as the 2 thermal ene reactants) equation:
3 Polymer 4 Backb ne ~ CH3 ~ ~ H hea~
H2C=C-CN - :~

~ 0 ~R3 13 A molecule of acrylonitrile adds to the polymer 14 at the site of pendant group unsaturation and involves allylic shift of one double bond, transfer of the allylic 16 hydrogen to the acrylonitrile and thus bonding between the 17 two unsaturated groups. It is understood that the exocyclic 18 olefinJ i.e. of the 5-ethylidine-2-norbornene, can only 19 shi~t away from the bridgehead to the C5 C6 position. A
shift of the double bond toward the bridgehead, i.e.
21 C~-Cs, is for~idden by Bredt's rule.
22 Ene adducts of this invention can be prepared by 23 any process which intimately mixes the nitrogen-containing 24 reactant or reactants with the copolymer and concurrently or subsequently heats the mixture to a temperature where 26 thermal ene addition occurs without appreciable generatlon 27 o~ free radicals. Reaction temperatures will generally be 28 at least 100G. to obtain addu~t formation at acceptable 29 rates and less than about 250C. to avoid any signiflcant copolymer breakdown and/or homopolymerization o the

- 11 ~3 l ethylenically unsaturated nitrogen-containing reactant~
2 Although preferred temperature ranges will vary with the 3 particular copolymer and reactant and can readily be 4 determined by one skilled in the art; optimally, it ranges from about 150C. to about 225C. J e.g. about 170C.
6 Mixing of the reactant and copolymer can ~e by blending 7 together nea~ or with a solvent in an internal mixer or 8 extruder. Preferably the blending and subsequent "ene"
9 reaction is carried out in a hydrocarbon solvent at elevated temperatures~
ll Thus in the preferred process, the ethylene

12 backbone copol~mer is dissolved in a hot solvent such as

13 benzene, heptane, cyclohexane, optimally, mineral oil, and

14 the reactant e.g~ acrylonitrile, is introduced into the solu~ion. The solution is heated at from about 150C. to 16 225C. for several hours in the substantial absence of air 17 or oxygen and, preferably under a blanket of inert gas, 18 e~g.~ nitrogen. Modest elevated pre~sures o~ the inert l~ gas can be used to maintain the reactant in solution.
Should a solvent other than mineral oil be usedg diluent 21 oil maybe added and the light solvent and unreacted 22 ethylenically unsaturated ni~rogen containing reactant 23 are then removed. The remaining residue is a solution of 24 ene adduct in diluent oil, particularly useful as an additive package for lubricating oils.
26 For said reactants which readily homopol~merize 27 under free radical conditions~ the ~ollowing method may be 28 utiliæed in order to moderate ~he generation oE ~ree ~ radicals:
Dissol~e said copol~mer, said reactant and up to 31 about 1 wt.% (based on weight of said reactant) o a free 32 radical scavenger (inhibitor such as hydroquinone to 1 eliminate homopolymerization of said reactant~ in a hot 2 solvent, such as mineral oîl, heptaneJ benzene, or cyclo~
3 hexane; andJ heat to reac~ion temperaturesJ e g. from 4 about 150C. to 225C. for several hours in the substan-tial absence of oxygen (flushed several times with nitrogen 6 prior to starting ~he reaction) and under a blanket o~
7 modestly pressurized inert gas, such as nitrogen. If the 8 solvent is not oil, then diluent oil may be added and the 9 light solvent and unreacted nitrile monomer can be readily removed. The reamining residue is a mixture of ene adduct 11 of the ethylene copolymer and said reac~ant in diluent oil.
12 The proportions in which the above-described 13 nitrogen-containing reactants are to be used may range 14 widely according to the abilîty of said ethylene copolymer and said nitrogen-containing reactant to react with each 16 other, but normally should range from about 0~1 to 400, 17 preferably about 10 to about 200 parts by weight of said 18 nitrogen-containing reactant to 100 parts by weight of said 19 ethylene backbone copolymer.
It is generally desired to form oil-soluble 21 adducts containing about 0O005 to 0 6%~ and preferably 22 about 0.02 to 0.50% by weight nitrogen (all of said % by 23 weight nitrogen values in this speci~ication determined by 24 the Kjeldahl method). Adducts containing such quantities of nitrogen have sufficient dispersancy sites for additive 26 applications, to enhance lubricatlng oil performance. To 27 achieve a desired degree o adduct ormation within a 28 reasonable tlme~ high concentrations of reactants (usually 29 a substantial excess of nitrogen-containing reactant) are helpful~ One will generally select an ethylene copolymer 31 having about thrice the amount of pendant group unsatura-32 tion as ls stoichiometrically tbased on nitrogen equivalent) ~ 8 ~

1 required for the desired amount of ni~rogen incorporation.
2 SimilarlyJ about two to ive times as much nitrogen-3 containing reactant (based on equivalent nitrogen) is 4 added as is desired in the oil-soluble adduct. ConverSiQn of about 20 to 50% of the nitrogen containing reactant 6 will result in copolymer adduct having the desired composi-7 tion. For example, if one desires to obtain an adduct 8 derived rom an ethylene/propylène/5-ethylidene-2-9 norbornene copolymer having 0.15 wt.~/o nitrogen content, he could conveniently mi~ said copolymer having 0.08 moles 11 pendant group unsaturation per kilogram of copolymer with 12 0.2 moles of acrylonitrile as s~id reactant and heat the 13 mixture for a time sufficient to convert 25% of the 14 nitrile reactant thereby obtaining the desired product~
If desired, two or more different ethylene backbone co-lb polymers and/or two or more different types of nitrogen-17 containing reactants can be reacted.
18 Ene adducts of the invention broadly will con-19 tain from 0.005% to about 7% by weight nitrog0n. As the nitrogen content increases above about 0O6 wt.%, the ene 21 adduct becomes increasingly less soluble in hydrocarbons 22 such as mineral oil w~ereby the adducts utility as a 23 hydrocarbon resistant material is increasedO ~urther, the 24 ene adduct undergoes reduced elasticity as the nitrogen content increases above about 1 wt~/o~
26 These ene adducts which include polar groups, 27 such as imides, amides, esters, anhydrides, epoxides, 28 nitriles (preferred), etc.~ ma~ also be hydrolyzed to 29 produce novel polymeric compositions which can be used per se as a dispersant and/or V.I. improver or which can 31 be used as an intermediate ~or the preparation of other 32 novel polymers are particularly useful as multifunctlonal 1 34~

1 V.I. improvers for mineral oil lubricantsO When used ~s 2 intermediates, these hydrolyzed ene adducts of the 3 invention can be tailored ~o provide varying functional 4 groups requisite for a given application. For example, as in the case of an adduct produced with acrylonitrile, 6 the resultant ene adduct can be readily hydrolyzed to 7 provide sites for reaction with alkylene polyamines to 8 provide enhanced lube oil dispersancy.
9 The hydrolysis of these ene adducts of the lo invention is readily carried out under alkaline (base 11 hydrolysis) or acidic (acid hydrolysis) condit~ons.
12 Suitable bases include alkali metal and alkaline ear~h 13 metal bases such as sodium hydroxide, potassium hydro~ide, 14 calcium hydroxideS barium hydroxide and the like. Suitable acids are mineral acids such as sulfuric acid~ nitric acid, 16 hydrochloric acid and the like~ Both the base and acid hydrolysis can be carried out at a temperature ranging 18 ~rom about 0CO to about 225C., prefcrably from about 20C.
19 to about 125 C. The hydrolysls is usefully carried out at relatively mild conditionsg i-0O only a catalytic amount 21 of the hydrolyzing agent is employed.
22 The corresponding carboxyl ~ontaining adducts 23 either in their original solution or aft2r isolation and 24 redissolving in suitable hydrocarbon solvents o the ~ype mentioned are contacted with approximately equimolar 26 amounts of nucleophilic reagents to convert the carboxyl 27 derivatives into the new nucleophilic derivatives.
28 Examples of suitable ~unctional nucleophilic reagent~ include water, Cl to Cl3 alcohols, Cl to Cl8 pre~erably C2 to Cl2 monobasic acids, Cl to Cl8 amines, 31 C2 ~o Cl8 amidesg phenol, thiophenol, alkyl phenols or 32 thiophenol wi~h l to 4 alkyl groups of l to 12 carbons

- 15 -~g~

1 each, Cl to Cl~ alkyl mercaptans, dialkylaminophenolsJ
2 N3N-dialkylamlnoarylene diamines, alkyl imidazolines~ aryl 3 ether alcohols, alkyl ether alkylene amines and the like.
4 Further descriptions of preferred ~orms of some of these functional agents follow:
6 The Cl to C13 alcohols can be branched or 7 unbranched saturated, alipha~icJ àromatic, primary, 8 secondary~ or tertiary alcohols, preferably monohydric 9 alcohols, but including other alcohols. Particularly lo preferred are polyhydric alcohols of 2 tv 6 hydroxy groups 11 as well as amino alcoholsO Examples include methanol, 12 isopropanol3 C8 Oxo alcohol, lauryl alcohol, benzyl 13 alcohol, ethylene glycol, monododecyl ether o triethylene 14 glycolJ glycerol, pentaerythritolJ glucose, dipentaery-thritol, sorbitol, Cellosolve~ Carbitol~ diethanolamine,

16 etc.

17 The Cl to C18, preferably C2 to C12 monobasic

18 acids, can be branched or unbranched9 saturated, aliphatic,

19 monocarboxylic acids, preferably the saturated fatty acids such as acetic acid, butyric acid, caproic acid, lauric 21 acid, etc.
22 T~e Cl to C18 amines can be branched or unbranched 23 saturatedJ aliphatic, primary or secondary amines, contain~
24 ing 1 to 8 nitrogens, preferably mono- or dlamines, such as ethylamine~ butylamine, sec. butylamine, diethylamine, etc., 26 but ineluding higher polyamines such as alkylene poly-27 amines/ wherein pairs of nitrogen atoms are joined by 28 alkylene groups of 2 to 4 carbon atoms. ThusJ polyæmines ~ of the formula:
NH2(cH2)n-[NH(~2)n]m-~H2 31 are lncluded where n is 2 to 4 and m is 0 to 6. Examples 32 of such polyamines ~nclude tetraethylene pentamine, 1 tripropylene tetramine, N-aminoalkyl piperazines, e.g., 2 M-(2-aminoethyl) piperazine, N~N'-di(2-aminoethyl) 3 piperazine~ etc. Particularly preferred are the C4 to Cl3 4 N,N-dialkylamino alkylene diamines such as N,N-dimethyl-l,3-propylene-diamine, etc Also, preferred is tetrae~hylene 6 pentamlne, as well as corresponding commercial mixtures B 7 suc~ as "Polyamine HJ ~I and "Polyamine 500~"
8 The alkyl phenols or thiophenols are those with 9 l to 4 alkyl groups, preferably averaging l to 2 alkyl groups, wherein the alkyl groups each contain l to l2 11 carbon atoms which can be straight chain or branched chain12 such as cresol, n-octyl phenol, di-n-octyl phenol, 13 monoisobutyl thiophenol~ etc.
14 The above-discussed reactions with the hydrolyzed adduct can be carried by procedures well known in the art.
16 For the preferred amine functionalization the amination of 17 the carboxylate groups is usefully carried out in a 18 solution by reaction with the hydroly2ed ene adduct 19 dissolved in a solvent such as mineral oil. The formation of the amide dispersants in high yield can be effected by 21 adding from about O.l to l, preerably about 0.7 to l~ molar 22 proportions of alkylene polyamine per molar proportion o~
23 carboxylate groups per kilogram of the hydrolyzed adduct to 24 said solution and heating the mixture at 140C. to 165C.
untll the appropriate amount of water o~ reaction is 26 evolved.
27 In some applications, it is useful to modify 28 the aminated hydrolyzed ene adduct dispersant by su~sequent ~ boration as generally taugh~ in U.S. Paten~s 3,087~936 and 3,254,025. This is readily accomplished by treating said 31 aminated ene adduct with a ~oron compound selected from 32 the class consi~ting of boron oxide, boron halides, boron 1 acids and esters of boron acids in an am~unt to provide 2 from abou~ 0.3 ~o 0.9 wt.% boron, based on the total 3 weight of said borated, aminatedg hydrolyzed ene adduct.
4 The nitrile ene adduct can also be converted to the corresponding imine or amine or mixtures of both through 6 reductive procedures well known to one skilled in the art.
7 Although the preferred method of reduction may be accom-8 plished with hydrogenation catalysts such as copper, g rhodium, palladium or nickel at elevated temperatures and pressures, li~hium aluminum hydride, sodium borohydride, 11 may also be used. Another suitable method of converting 12 said nitrile to an amine is ~hrough the use of Grignard 13 reagents.
14 It is understood that the placement of a nitrile such as described above onto said chain now provides a 16 site for further reactions such as chlorination, bromina-17 tion~ alkylation, or the like. Once halogenated, this 18 position may be reacted with various nucleophiles as 19 described above to produce a new type of ~unctionality.
For example, the haloger~ may be displaced with an amine9 21 to provide additional functionality.
22 Generallyg the number average molecular weights 23 of the final polymeric adduc~s of ~he present invention, 24 employed as lubricant additives, will be in the ran~se of about lO00 to about 50a,000 and pre~erably will be in the 26 ran~e of about l0,000 to 200,000. However, it will be 27 understood that higher or lower molecular weight products 28 may l:~e prepared, if desired. All molecular we:Lght values -29 se~ forth in this specification are number average molecular welghts ~n) as determined by vapor phase osmometry (VPl)) 31 and membrane osmometry.
32 When the adduct additives of the present invention 1 are employed in lubricating oils3 they are preferably added 2 in proportions o~ about 0.01 to about 20.0% or more~ prefer-3 ably about 0.1 to 10.0%, and more preferably about O.S to S.0 4 percent by weight. The proportions giving the best results will vary somewha~ according to the nature of the adduct ad-ditive, the nature of the lubricating oil base stock to which 7 it is added and the specific purpose which the lubricant is 8 to serve in a given case. For commercial purposes9 it is 9 convenient to prepare concentrated oil solutions in which the lo amount of adduct additive in the composition ranges from 10 11 to about 49% by weight~ and to transport and store them in 12 such form. In preparlng a lubricating oil composition for 13 use as a crankcase lubricant the adduct additive concentrate 14 is merely blended with the base oil in the required amount.
The products of the present invention may be 16 employed not only in ordinary hydrocarbon lubricating oils 17 but also in the "heavy duty" type of lubricating oils which 8 have been compounded wlth such detergent ~ype additives as 19 metal soaps, metal petroleum sulfonates, metal phenates, metal alcoholates and metal alkyl phenol sulfides.
21 The lubricating oil base stocks used in the 22 compositions of this invention may be straight mineral 23 lubricating oils or distillates derived ~rom paraffinic, 24 naphthenic, asphaltic, or mixed base crudes~ or, i desired~
2s various blended oils may be employed as well as residuals, 26 particularly those ~rom which asphaltic consti~uents have 27 been careully removed. Hydrogenated oils~ white oils, or 28 shale oil may be employed as well as synthetic oils 29 prepared, or example~ by the polymerizatlon o~ olefins or by the reaction of oxides of carbon with hydrogen or 31 by the hydrogenation of coal or its products or one may 32 use es~ers of mono-ordibasic acids, es~ers o glycols) or ~ ~ 9 ~ ~ ~

l complex esters~ etc. Mixtures of any of the above or 2 wi~ mineral, animal or vegetable oils in any proportions 3 may al~o be usedO
4 E~AMPLE 1 6.75 grams o~ an ethylene copolymer consisting 6 of about 50 wt.% (63 mol %) e~hyleneg 41 wt,% (34 mol %) 7 propylene and 9 wt.% (3 mol %) of 5-ethylidene-2-nor-8 bornene having a Mn of about 60,000, was dissolved in 83.25 9 grams of Solvent-150 Neutral (S150N) mineral oil was placed in a 500 ml. reaction vessel suppor~ed on an electrio ll heater so that the temperature of the reactants could be 12 controlled. 2.7 grams (0O05 moles) of acrylonitrile 13 was introduced into the reaction vessel ater which the 14 vessel was flushed with nitrogen and subjeoted to a nitrogen pressure of about two inches of mercury which l6 elevated pressure was maintained during the entire reaction 17 period. The reaction was carried out by heating the 18 ingredients with agitation at a temperature o~ about 150C.
19 for about 6 hours. T~e reaction vessel was thereafter cooled to room temperature and the adduct product was 21 freed of other ma~erials by dialysis against a semiper-22 meable rubber membrane overnight with boiling he~ane. The 23 dialyzed residue was ~hen dried for about 12 hours in a 24 vacuum o~en maintained a~ about 60C. and 120 ~m Hg pressure whereby 4.15 gram~ of product adcluct w~s obta-lned 26 which contained 0.074 weight /O nitrogen.

28 The procedure of Example 1 was followed with ~ the following variations:
The ethylene copol~mer contains about 50 wt~/o 31 (61 mol %) ethylene~ ~5 wt.% (37 mol /O) propylene and 32 5 wt.% (2 mol %) 5-ethylidene-2-norbornene with a Mn o

- 20 -1 about 45,000; 5 gxams of said polymer was dissolved in 2 60 grams of said mineral oil; 1 gram (0.006 moles~ of 3 N,N-dimethylamino ethyl methacrylate replaced the 4 acrylonitrile; and the reaction was carried out at a temperature ranging from 190 to 210C~ ~or 7 hours;
6 3.0 grams of an adduct product ~ontaining 0.03 wt.%
7 nitrogen was obtained.

9 The process of Exa~ple 1 was followed however the ingredients and conditions was varied in the following ll manner:
12 The ethylene copolymer contained about 50 wt.a/o 13 (60 mol %) ethyleneg 46 wt~% (38 mol %) propylene and 14 4 wt.% (2 mol %) 1,4~hexadiene wit~ a Mn of about 50,000.
(This ethylene copolymer iæ available as Nordel 1320 from 16 E.I. duPont de Nemours & Co.) 2.25 gram~ of said polymer 17 was dissolved in 67.75 grams of Solvent 150 N mineral oil;
18 the amount of acrylonitrile was 20 grams ~10 grams added 19 after 5 hours); the reaction conditions were 150 to 160G~
for 12 hours; and the product yield was 2.1 grams of the

21 adduct product containing 0.20 wt.% nitrogen.

22 EXAMPLE 4

23 In this example the general procedure of Example 1

24 was ~ollowedJ however, the polymerization vessel was replaced with a 3-liter rocker bomb lnto which 200 grams 26 of the ethylene copol~mer o~ Exa~ple 1, 2200 ml of heptane, 27 25 grams (0.47 moles) of acrylonitrlle and 2 grams of 28 hydroquinone were introduced and the vessel sealed. The atmosphere in the vessel was replaced wi~h ni~rogen and then pressuxized with nitrvgen to about 500 psi at room 31 temperature. The bomb was rocked at a temperature from 32 about 171 to 179Co for 19 hours. The product was separated by precipitation from me~hanol and yielded 105 2 grams of recovered adduct conkaining about 0.084 wt.~/o 3 nitrogenO

The 3-liter rocker bomb described above was used 6 in t~is example. 200 grams of the ethylene copolymer of 7 Example 2, 2200 ml o heptane~ 11 grams tO.21 moles~ of 8 acrylonitrile and 1 gram of hydroquinone were introduced 9 and the bomb sealed. The contained air was replaced with nitrogen and then the reactor was pressurized with nitrogen ll to about 500 psi at room temperature. The bomb was seal~d l2 and rocked at a ~emperature o 150 for 10 hours then 200 l3 for 2 hours. The reactor was next cooled, 200 ~c of l4 sample taken) then 100 grams (1.88 moles) of additional acrylonitrile added, and the above procedure repeated at 16 a temperature o 150 or 12 hours. The reactor was cooled 17 and the pro &ct recov~red by precipitation from me~hanol 18 to yield 143 g. of adduct which contained 00092 wt~%
19 nitrogen.
~X~ _ 9 21 The following examples are all set forth in 22 tabular form in Table I.

.

. - . .. , . :
., . -: - , .~ . , O O O 0 ~0 _ C`J O0~ 5 ~1 ~ ~ ~1 ~ O
~ ~ ~ ~ ~ I ~

~7 O ~ O
o I~ C~l O
. ~ ~ .
O O O O ~O
u~
q~
.~ 4_~
.~ a~ oo 00 00 g ~

~1 r 9 c ~ ~ . o r~
c) .,~ ~ ~ ~ ~ ~ o ¢ ~ :~
- , ~., ~0 æ~ o ,~ ~

a oP
~ ~ o ~ ~ ~
~, ~ o C~
~ o I :~

;~
E~ 4 O O

.

__ 2 200 grams of the copolymer of Example 2 (reac~ed 3 as a 10 wt.% solution in hexane) was processed similar to 4 the procedure of Example 5 with the following variations:
the pressure was 400 psi; the bomb rocked at 170C. for 6 15 hours; the reactor contents were filtered prior to 7 precipitation; and, the resulting yield of product after 8 drying ~n a ~acuum oven was 130.7 grams of an ene adduct 9 which con~ained 0.075 wt.% nitrogen~

.
ll (A) The following illustrates hydrolysis of an 12 ene add~ct. Into a dry flaskg under a nitrogen atmosphere l3 was carefully placed a sample of the ene adduct of Example 14 10 (5 g. of adduct) in toluene ~100 ml) and refluxed wlth 3 g. potassium hydroxide dissolved in 15 cc distilled water.
16 The refluxing took place at 90~94C ~or 6.0 hours. The 17 solution was cooled to amblent tempera~ure and the hydrolyzed 18 copolymer recovered by precipi~ation from methanol (2 liter).
19 The resulting copolymer was washed with me~hanol (500 ml) then dried in a vacuum oven at 100C for about 15 hours~
21 after which 4.05 g o copolymer was recovered. The nitrogen 22 level of the resulting copolymer was 0.03 wt.%.
23 ~B) The following illustra~es amînation of a 24 hydrolyzed ene adduct. 2 g. of the copolymer o Example 2S ll(A3 above was dissolved in toluene (100 ml3 ~hen care-26 ully re1uxed (110C) under a ni~rogen atmosphere with a 27 solution of 0.5 g diethylene triamine for 5 hrs. The 28 ~olu~ion was cooled to ambient temperature and ~he amina~ed 29 copolymer recovered by precipita~ion from me~hanol ~o yield 1.9 g of product (95% yield). The nitrogen level o the 31 resulting product wa~ 0~09 wt~%.

- 2~ -~ ~9 ~ 8 2 In thîs example the ef~icacy o~ the adducts of 3 this invention, particularly with regard to their unusual 4 dispersancy properties in lubricating oil applications, is illustrated by comparison with a commercially available B 6 multifunctional V.I. impro~er, sold as Lz 3702 by Lubrizol 7 Corporation of Cleveland, Ohio7 in a Sludge Inhibition 8 Bench Test (hereinafter designated SIB). The SIB test has 9 been found, after a large numbPr of evaluations~ to be an excellent test for assessing the dispersing power o 11 lubricating oil dispersant additives.
12 The mediu~ chosen ~or the SIB test was a used 13 crankcase mineral lubricating oil compositlon having an 14 original viscosity of about 325 SUS at 38C~ that had been used in a taxicab that was driven generally for short trips 16 only, thereby causlng a buildup of a high concen~ration of 17 sludge precursors. The oil t~at was usPd contained only a 18 refined base mineral lubrlca~ing oil, a viscosi~y index 19 improver, a pour point depressan~ and æinc dialkyldlthio-phosphate antiwear additive. The oil contained no sludge 21 dispersant. A quantity of such used oil was acquired by 22 draining and refilling the taxicab crankcase at l000 2000 23 mile intervals.
24 The Sludge Inhibition Bench Tes~ is conduc~ed in the following manner. The aforesaid used crankcase oil~
26 which is milky brown in color~ is ~reed of sludge by 27 c~ntriuging for l hour at about 39,000 gravitles (gs.~.
28 The resulting clear bright red supernatan~ oil is then ~ decanted from the insolublP sludge particles ~hereby separated out. However, the supernatant oil still contains 31 oil-soluble sludge precursors which on heating under the 32 conditions employed by this test will tend to form additional /t ~a f,/rD ~Y~ 4 - 25 , - -.~ ' ' .

4~

l oil-insoluble deposits of sludge. The sludge inhibiting 2 properties of the additives being tested are dstermined by 3 adding to portions of the supernatant used oil, a small 4 amount, such as 0.5, 1 or 2 weight percent~ on an active ingredient basis, of the particular additive being tested.
6 Ten grams of each blend being tested is placed in a stain-7 less steel centrifuge tube and is heated at 280F. for 8 16 hours in the presence of air. Following the heating~ the 9 tube containing t~e oil being tested is cooled and then centrifuged for 30 minutes at about 399 000 gs. Any 11 deposits of new sludge that form in this step are 2 separated from the oil by decanting ~he supernatant oil and then carefully washing the sludge deposits wlth 25 ml. of pentane to remove all remaining oil ~rom the sludge. Then the weight of the new solid sludge that has been formed in 16 the test, in milligrams, is determined by drying the 17 residue and weighing it. The results are reported as %
18 of sludge dispersed by comparison wlth a blank not 19 containing any additional additive. The less new sludge formed, the larger the value of percent sludge dispersant, 21 and the more effective is the additive as a sludge 22 dispersant. In other words, if the additive is effective, 23 it will hold at least a portlon of the new sludge that forms 24 on heating and oxidation~ stably suspended in ~he oil 50 it does not precipitate down d~ring ~he centrifuging. Using 26 the above~desoribed testJ the dispersant action o~ the 27 several adducts prepared in accordance with this invention 28 were compared with the dispersing power of a dialyzed ~ product obtained rom dialysis of a commercial dispersan~
previously referred to as Lz 3702. Sufficient dialyzed 31 residue which analyzed about 0.~ wt.% nitrogen, was 32 dissolved in S-l~ON mineral oil ~o provide a 10% active ~ 9~

1 ingredient concen~rateO The dialyzed residue and adduct 2 products of the inven~ion were approprlately diluted in 3 mineral oil ~o furnish the 0.0125~ 0.025, 0.05 and .1 wt.%
4 of added additive test samples~ The test results are S given in Table II.
6 ~
7 Concn. gms.
8 polymer/10 gms. % sludge 9 E a~ple Poly~ r of Used Oil dispersed 12-A Example 1 .1 96 ll .05 88.4 1~ .025 37.5 13 12-B Example 2 .1 82 1~ .05 53 12-C Example 3 .1 52~5 16 .Q5 37.6 17 12-D Example 4 ~1 79 r 9 19 12-~ Example 5 .1 91~S
.0~ 80l1 21 .025 62.0 22 .0125 36~7 23 12-F Example 6 ~1 96 24 .05 73 12-G Example 7 .1 79,3 26 .05 72.4 27 12-H Example 8 .1 95.0 2~ .05 g0.3 29 .~25 32.0 12-I Example 9 .1 82.7 31 ~05 71.6 32 12-J Lz 3702 .1 88.7 33 .Q5 73~3 34 .025 30.5 .0125 4.8 36 12-K Example 11 0.1 78 37 0~05 79 38 The e~e adducts o ~xamples 1~11 are derlved 39 from copolymers which have viscosity index improving properties for lubricating oils. The data of Table II

41 thereore shows that the multifunctional V.I., ene adducts l and ene adduct derivatives o~ the invention possess 2 superior dispersancy to a commercially available multi-3 functional V.I, additive. The superior dispersancy is 4 obtained at a much lower nitrogen content, e.g. the nitrogen of Example 1 is 0.074 wt.% whereas that of 6 Lz 3702 is 0.4 wt.%. It is also apparent from Table II
7 that an adduct prepared from a polymer containing a cyclic 8 nonconjugated diene is superior in dispersancy to one 9 obtained from a polymer containing a linear nonconjugated diene (compare Example 12-A with Example 12-G).
1 1 ~:~
12 The nitrogen-containing adduct of the ethylene 13 copolymer prepared in Example 9 was tested as a viscosity B 14 index improver in ENJ 102~ a blended mineral lubeloil containin~ O.S wt.% of a polymeric pour depressant. The 6 blend was of two para~finic, solvent refined neutral oils, 17 one of which had a viscosi~y o about 150 SUS at 100F.
18 and constituted 25.75 weight percent of the blend; and, 19 the other had a viscosity of about 300 SUS at 100F~ and constituted 73.75 weight percent of the blend. ~he 21 comparative resul~s of the adduct-modified ENJ 102 22 (Example 13-A) and the ENJ 102 (Example 13-B) are 23 summarized in Table III

K.V. (Cs) Vis. (P) Pour Pt. % sonic 26 Example @99C. ~-18C. _ _ breakdown 27 13-A 12.21 23.5 -37 29 23 13-B 6.26 19.2 37 0 The data of Table III shows that an adduct of this invention has V.I. improYing charact~ristics while exhibiting 31 no d0trimental loss in pour point depression and suitable 32 shear stab~lity as reprssented by sonlc breakdown.
~ ~J~ 8 -

Claims (8)

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

1. Hydrolyzed oil-soluble ene adduct or its oil-soluble amide derivative, said adduct being of a C3 to C24 ethylenically unsaturated nitrogen-containing reactant having at least one electron withdrawing group and a copolymer of ethylene, at least one C3 to C50 alpha-monoolefin and at least one C5 to C24 non-conjugated diene, said hydrolyzed ene adduct containing carboxylate groups in molar concentration ranging up to about the molar con-centration of said reactant and having a number average molecular weight of from about 1,000 to about 500,000.

2. Hydrolyzed oil-soluble ene adduct of a C3 to C24 ethylenically unsaturated nitrogen-containing reactant having at least one electron with-drawing group and a copolymer of ethylene, at least one C3 to C50 alpha-mono-olefin and at least one C5 to C24 non-conjugated diene, said hydrolyzed ene adduct containing carboxylate groups in molar concentration ranging up to about the molar concentration of said reactant and having a number average molecular weight of from about 1,000 to about 500,000.

3. The hydrolyzed ene adduct of claim 2, wherein said nitrogen-containing reactant is acrylonitrile.

4. An oil-soluble amide,suitable as a lubricating oil sludge dispersing additive, of a hydrolyzed ene adduct of a C3 to C24 ethylenically unsaturated nitrogen-containing reactant having at least one electron with-drawing group and a copolymer of ethylene, at least one C3 to C50 alpha-mono-olefin and at least one C5 to C24 non-conjugated diene, said amide containing from about 0.005 to about 0.8% by weight nitrogen and having a number average molecular weight of from about 1,000 to about 200,000.

5. An oil-soluble amide of claim 4, wherein said C3 to C24 ethylen-ically unsaturated nitrogen-containing reactant is acrylonitrile; wherein said copolymer comprises about 30 to 85 mole % ethylene, about 15 to 70 mole %
C3 to C8 alpha-monoolefin and about 2 to 15 mole % C5 to C24 non conjugated diene, said copolymer having a molecular weight in the range of about 10,000 to about 200,000; and wherein said amide is formed by reacting said hydrolyzed ene adduct with a C1 to C18 amine.

6. An oil-soluble amide according to claim 5, wherein said amine is an alkylene polyamine.

7. A lubricating oil composition comprising a major proportion of lubricating oil and in the range of about 0.1 to 10 wt. % of the oil-soluble amide of claim 5.

8. A lubricating oil composition comprising a major proportion of lubricating oil and in the range of about 0.1 to 10 wt. % of the oil-soluble amide of claim 6.