JPS62959B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD This invention relates to novel lubricating oil additives and their production. More particularly, the present invention relates to improving the viscosity index of lubricating oils through the addition of a class of ethylene copolymers that provide the lubricating oil with excellent low temperature viscosity properties. Recently, ethylene/propylene copolymers have become widely used as viscosity improvers in lubricating oils due to their low processing levels and improved viscosity properties. However, the market requires different molecular weight grades with different degrees of thickening effect (commonly referred to as thickening ratio) for use with mineral oils of different viscosities. Although the production of each such copolymer grade can be accomplished by direct synthesis, the various molecular weight grades can be obtained by degradation of the ethylene-propylene copolymer to produce lower molecular weight variants. can. It is advantageous to use a reduction method. This is because large quantities of copolymers are produced in large-scale polymer plants,
It is then economical to use this as a base material and decompose it into lower molecular weight grades to meet the demands of the viscosity index improver market.
There are various means to achieve such degradation, such as heating an amorphous rubbery ethylene-propylene copolymer at 260-420°C for 30 minutes with the exclusion of air.
heating for ~30 minutes (see British Patent No. 1001455), extruding and heating the ethylene copolymer first to melt at a temperature of 150-280°C and then at a temperature of 300-500°C (see Canadian Patent No. 1001455) with exclusion of air. 991,792), as well as oxidative and mechanical degradation such as by mastication of ethylene-propylene copolymers, preferably free of other monomers such as dienes (see US Pat. No. 3,769,216). Ethylene terpolymers containing dienes such as vinylnorbornene are known to be unsuitable for mechanical degradation such as oxidation by mastication in the presence of air or oxygen. This is because this degradation technique produces excessive amounts of oil-insoluble gel particles. It has also been found that the presence of ethylene copolymer VI improvers in conventionally formulated lubricating oils often undesirably increases the cold pour point of lubricating oils containing pour point depressants. This appears to occur because these copolymer VI improvers interfere with the action of lubricating oil pour point depressants. Typical of these copolymer VI improvers, which are often incompatible with pour point depressants, are ethylene-propylene copolymers containing 60 to 80 mole percent ethylene (U.S. Pat. No. 3,697,429). reference). One solution to overcome this incompatibility problem is taught in U.S. Pat. No. 3,697,429, where the VI improver is composed of two ethylene copolymers,
A first copolymer of ethylene and _C3 - _C18 higher α-olefin with an ethylene content of 50-95 mol% (40-83% by weight) and 5-80 mol% (3-70% by weight) of ethylene. Ethylene with content C ₃ ~ C ₁₈
a second copolymer with a higher α-olefin, and the ethylene content of the first copolymer is at least 5 mole percent (4 weight percent) greater than the ethylene content of the second copolymer. These ethylene copolymers contain diolefins containing about 6 to 28 carbon atoms as the third monomer, such as 5-vinyl-
It can contain 2-norbornene. The ethylene copolymer of the mixture is selected to provide a weight average ethylene content comparable to a specific model weight percent at pour point maximum for a particular lubricating oil. Herein, in the present invention, at least about 1% by weight
The ethylene/ _C3 - _C18 α-olefin terpolymer containing a _C1 - _C21 alkyl-substituted norbornene has improved compatibility with pour point depressants and, if desired, its molecular weight is lower than that of the oil. It has been found that it can be easily degraded by oxidative and mechanical degradation without deleterious formation of insoluble gel particles. A lubricating oil composition according to the invention provides a lubricating oil composition with a number average molecular weight (Mn) of at least 5000, a weight average molecular weight (Mw) of less than 8 as measured by a log average molecular weight (Mn) ratio of at least 5000. 1.0 to 3 preferably when compared to polyisobutylene with molecular weight distribution and viscosity average molecular weight (Mv) of 20000
having a thickening ratio within the range of 1.2 to 24, and 26 to 79% by weight ( ₃₅ to 85 mol%) of at least one C3 to _C18 α-olefin such as ethylene, propylene, and ethylnorbornene. at least a viscosity index improving dose of an oil-soluble ethylene copolymer containing about 1 to 25, preferably 2 to 10% by weight _C1 - _C21 alkylnorbornene and preferably at least a pour point depressing dose of a lubricating oil pour point depressing dose. including agents. In a preferred embodiment, the ethylene copolymer is prepared at a temperature of about 95-260°C, preferably in the presence of air.
Oxidatively and mechanically degraded by masticating for 0.25 to 20 hours, whereby the thickening rate is increased from a value greater than about 3, e.g. from about 4 to 1.0 to 3.0, preferably
and the oxygen content of the ethylene copolymer is about 0.005 to 6, preferably 0.05 to 3% by weight, based on the total weight of the copolymer. Mechanically degraded and oxidized copolymers can be reacted with polyamines to obtain dispersibility, thereby providing polyfunctionalization, i.e., the copolymers are Approximately 0.005~
4 Preferably contains 0.05 to 2% by weight of nitrogen. Thickening rate (TE) is the viscosity of 150SUS (37.8℃),
Solvent extracted neutral mineral lubricating oil (Solvent 150) with a viscosity index of 105 and an ASTM pour point of -17.8°C.
neutral) to 12.4 centistokes (98.9℃)
Polyisobutylene (PARATONE) by Exxon Chemical Company, New York, New York, USA, with a Schausinger molecular weight of 20,000 required to thicken to a viscosity of
It is defined as the ratio of the weight percent of a test copolymer required to thicken the same oil to the same viscosity at the same temperature. Ethylene copolymers containing ethylene, long chain α-olefins, norbornene, and alkenyl-substituted norbornene monomers are known as VI improvers. U.S. Pat. No. 3,598,738 describes comonomers such as _C3 - _C12 alpha-olefins, terminally unsaturated non-conjugated _C5 - _C8 diolefins, 2-norbornene and 5-methylene-2-norbornene, and mixtures thereof. It is taught that oil-soluble ethylene copolymers containing oil-soluble ethylene copolymers can be used as viscosity index improvers for mineral oil compositions. According to the teachings of the present invention, ethylene and _C3 - _C18
Alkylnorbornene, an essential group of monomers for copolymerization with higher α-olefins, is about 8 to 28
alkyl-substituted norbornene containing about 8 to 12 carbon atoms, preferably about 8 to 12 carbon atoms. Suitable norbornene monomers include methylnorbornene, isopropylnorbornene, butylnorbornene, pentylnorbornene, dodecylnorbornene, octadecylnorbornene, eicosylnorbornene, and preferably ethylnorbornene. Mixtures are also useful. The long chain α-olefins that can be used alone or in mixtures in preparing the ethylene copolymers used in the practice of this invention include from 3 to about 18
A monomer containing 5 carbon atoms. These α-olefins may be linear or branched if the branching occurs three or more carbon atoms away from the double bond. Although a single olefin is preferred, mixtures of _C3 to _C18 olefins can also be used. suitable
Examples of C ₃ to C ₁₃ α-olefins include propylene, 1-butene, 1-pentene, 1-hexene,
1-heptene, 1-octene, 1-nonene, 1-
Decene, 5-methyl-1-hexene, dimethyl-
Mention may be made of 1-pentene, 4-methyl-1-heptene and mixtures thereof. However, it is preferred to copolymerize ethylene monomer with propylene. Generally, the ethylene, _C3 - _C18 higher alpha-olefin and alkylnorbornene copolymers used in accordance with the present invention contain about 26-79% by weight ethylene, about 20-73% by weight C3 _- C ₁₈ α-olefin and 1 to 25 preferably 2 to 10% by weight of alkylnorbornene monomers. Preferably, the copolymer is derived from about 40-65% by weight ethylene, about 34-59% by weight _C3 - _C18 alpha-olefin, and about 2-10% by weight alkylnorbornene. The most preferred copolymer is 53% by weight ethylene, 38.3% by weight propylene and 8.7% by weight.
Derived from % by weight of ethylnorbornene. The copolymers of the present invention can be characterized by the following properties.

[Table] Mixtures of these monomers can also be used,
That is, more than one higher α-olefin and/or more than one alkylnorbornene can be used. Other compatible components may also be present, including those that can be copolymerized to form the quaternary polymer. In no case should the diolefin content exceed 1% by weight, preferably it should be less than 0.8% by weight. This is because the ethylene copolymers of the present invention containing excessive amounts of diolefins cannot be usefully degraded in accordance with the degradation procedures of the present invention. Generally, these copolymers contain compounds of transition metals from groups b, b and b of the Periodic Table of the Elements, in particular compounds of titanium and vanadium, such as VOCl ₃
a main catalyst consisting of a main catalyst, a co-catalyst,
It can be prepared by a catalyst composition comprising an organic reducing compound from groups b and a, in particular an organoaluminum compound such as (C ₂ H ₅ ) ₃ Al ₂ Cl ₃ . Examples of suitable catalysts and preferred reaction conditions are found in U.S. Pat.
Described in No. 3551336. The polymerization is carried out using ethylene, α- _C3 to _C28 monoolefins, preferably propylene, and alkyl-substituted norbornene monomers, preferably ethylnorbornene, in a liquid inert diluent-solvent reaction medium containing catalyst and cocatalyst in catalytic amounts. and hydrogen to produce the copolymer. The non-reactive reaction medium may be an aromatic hydrocarbon such as toluene, a saturated aliphatic hydrocarbon such as heptane, pentane and hexane, or a chlorohydrocarbon such as tetrachloroethylene. All steps in this reaction should preferably be carried out in the absence of oxygen, moisture, carbon dioxide or other harmful substances. Preferably, all reactants and catalysts are pure and dry and may be surrounded by an inert gas such as nitrogen. During the polymerization, the reaction mixture is maintained at a temperature of -40 to 100°C, preferably -10 to 70°C, optimally about 30°C and 0 to 100°C.
It can be stirred and maintained at a pressure of 1000 psig, preferably 0 to 30 psig, optimally 60 psig, for a period of 1 to 300 minutes, preferably 3 to 60 minutes, optimally 15 minutes.
At the end of this period, the reaction mixture can be treated to separate the product copolymer, or the mixture can be used as is for degradation. Alternatively, the ethylene copolymers of the present invention could be prepared by hydrogenation of prior art copolymers incorporating alkenylnorbornene, such as 5-ethylidene-2-norbornene, as the third comonomer. . Hydrogenation to remove unsaturation of pendant alkenyl groups can be carried out, for example, by the method described in U.S. Pat. No. 3,795,615 (see Example 1), by dissolving the copolymer in cyclohexane, adding Raney nickel as a catalyst, and treating the metal The system is pressurized with hydrogen to approximately 3600 psi by use of a cylinder and the contents are then pumped to 250 psi.
This can be easily carried out by heating at 0.degree. C. for about 16 hours and working up the reaction mixture to recover the hydrogenated copolymer. The hydrogenated copolymer can then be used as an improver or subjected to oxidation-amination as described below. Oxidation and Mechanical Degradation of Copolymers These ethylene copolymer viscosity index improving additives of the present invention can be readily processed by mastication in air, such as with a mechanical shearer, such as a Banbury mixer. It has been found that the molecular weight can be reduced. This treatment is a shear-stable ethylene copolymer that provides "as-grade" performance when formulated into lubricating oils, which is important, if not essential, for modern high-performance engine lubrication. bring about union. This discovery that these materials could be masticated in a high shear machine was surprising. That is, 1
Commercially available terpolymers having more than 1% by weight of cyclic diolefins such as "Vistalon 2504" sold by Exxon Chemical Company of Hyuston, Texas, USA or 1% by weight.
This is because products containing the above-mentioned linear diolefins, such as "Nordel 1320" sold by DuPont of Wilmington, Delaware, USA, form an oil-soluble gel when masticated in air. This gel formation is unacceptable. This is because the masticated and oxidized terpolymers are each insoluble in mineral oil and are no longer useful as viscosity modifiers. The mechanical-oxidative reduction of the ethylene copolymer can be carried out in a single piece of equipment or can be carried out in stages. It is preferred to operate in the absence of solvents or fluxing oils so that the ethylene copolymer is easily exposed to air as taught in French patent application No. 7523806. Useful equipment includes Banbury mixers and mills with adjustable gap, which may be enclosed in a jacketed container through which a heating medium such as overpressure steam or heated DOWTHERM can be passed. can. Fluxing oil can be added to the degraded ethylene copolymer when the desired level of degradation is reached, as measured by oxygen uptake and decrease in viscosity index (TE) as described above. Typically, sufficient oil is added to provide a degraded copolymer concentration within the range of about 5 to 50 weight percent, based on the weight of the total solution obtained. The resulting oil solution can then be used as a commercial product such as a lubricating oil additive or can be easily incorporated into lubricating oils. Useful temperatures for mechanical-oxidative degradation of ethylene copolymers are within the range of about 95-260°C. The time required to achieve a satisfactory result depends on the type of reduction or mastication equipment, the reduction temperature and especially the rotational speed if a blade mixer is used as the reduction or mastication equipment. In this regard, the Bramley-Betzken blade mixer has been found to be particularly useful in providing the desired degree of mastication or milling and oxidative reduction in a single piece of equipment. This mixer, which is equipped with a variable speed drive, has two rollers with peripherally arranged knives connected such that one roller rotates at half the speed of the other. The rollers are journalled in a jacketed reactor that has two hemispheres at its bottom (which correspond to the radii of the two rollers). Superheated steam or heated "DOWTHERM" can be circulated through the jacket to provide the desired temperature. If you use this mixer, the temperature will be approximately 95 to 260℃.
A satisfactory reduction in the thickening rate can be obtained in a temperature range of 0.25 to 20 hours. Instead of using fluxing oil, other inert solvents can be used to prepare the fluid solution of the ethylene copolymer; examples of such inert solvents include naphtha, hexane, cyclohexane, dodecane, and mineral oil. liquid hydrocarbons such as , biphenyl, xylene or toluene, solvent-neutral lubricating oils, white lubricating oils, chlorinated solvents such as dichlorobenzene, and the like. The amount of solvent is not critical as long as a sufficient amount is used to provide a fluid solution of the ethylene copolymer to facilitate mechanical-oxidative degradation. Such solutions, as described above, typically contain from about 50 to about 95% by weight solvent. The oil-soluble ethylene copolymer additives containing oxygen- and nitrogen-containing derivatives of the present invention are present in lubricating oil compositions, such as automotive or diesel crankcase lubricants, in at least viscosity index-enhancing doses and generally throughout the composition. about 1 to 15% by weight, preferably 2 to 7% by weight of
It is blended in a concentration within the range of % by weight. Additionally, these oil-soluble degraded ethylene copolymer polymer improvers of the present invention can be derivatized into multifunctional improvers by the addition of sludge dispersant activity. This can be easily accomplished by reaction with an amine compound or its grafting onto the ethylene copolymer material. Useful amine compounds for introducing Slutnid dispersion activity include about 2 to 60, e.g., 3 to 20, total carbon atoms and about 1 to 12, e.g., 2 to 20, total carbon atoms in the molecule.
Mention may be made of mono- and polyamines with 6 nitrogen atoms, which may be hydrocarbyl amines or with other groups such as hydroxy groups,
It may be a hydrocarbyl amine containing an alkoxy group, an amide group, an imidazoline group, etc. Preferred amines are aliphatic saturated amines having the general formula

[Formula] and

[Formula] [In the above formula, R, R' and R'' are hydrogen, C ₁ - C ₂₅ straight chain or branched alkyl group, C ₁ -
selected from the group consisting of _C12 alkoxy _C2 - _C6 alkylene groups, C2 _{- C12} hydroxy or aminoalkylene groups and _C1 - _C12 alkylamino _C2 - _C6 alkylene groups, where s is preferably 2-6 and t is a number from 0 to 10, preferably from 2 to 6. Non-limiting examples of suitable amine compounds include mono-, di-, and tri-tallow amines;
1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1,
2-propylene diamine, di-(1,2-propylene) triamine, di(1,3-propylene) triamine, N,N-dimethyl-1,3-diaminopropane, N,N-di(2-aminoethyl) ―
Examples include 1,3-propylene diamine, 3-dodecyloxypropylene amine, N-dodecyl-1,3-propanediamine, trishydroxymethylmethylamine, diisopropanolamine and diethanolamine. Other useful amino compounds include cycloaliphatic diamines such as 1,4-di(aminomethyl)cyclohexane, and imidazolines and the general formula [In the above formula, Z is oxygen or NG, G is selected from the group consisting of hydrogen and Ω-aminoalkylene groups having 1 to 3 carbon atoms, and p is an integer of 1 to 4. Examples include heterocyclic nitrogen compounds such as N-aminoalkylpiperazine. Non-limiting examples of such amines include 2-pentadecyl imidazoline, N
-(2-aminoethyl)piperazine, N-(3-
aminopropyl)piperazine, N,N'-di(2
-aminoethyl)piperazine and n-propylaminomorpholine. Commercially available mixtures of amine compounds can also be used advantageously. For example, one method for producing alkylene amines is to react an alkylene dihalide (such as ethylene dichloride or propylene dichloride) with ammonia to produce a complex mixture of alkylene amines in which nitrogen pairs are linked by alkylene groups. However, this includes forming compounds such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and piperazine isomers. A low cost poly(ethylene amine) compound with a composition close to tetraethylene pentamine is commercially available under the trade name "Polyamine 400 (PA-400)" by The Fraser Chemical Company, New York, New York, USA. It is possible. Similar materials can be made by polymerization of aziridine, 2-methylaziridine and azetidine. Still other amines separated by heteroatom chains such as polyethers or sulfides can be used. Introduction of sludge dispersion activity can be achieved by various means, for example, as described in German Published Patent Application No.
Reacting an oil-soluble ethylene copolymer with an oxygen-containing gas and an amine compound at a temperature of about 130 to about 300°C while mechanically degrading the same in accordance with DOS 2605796, October 13, 1976. US Patent No.
4,051,048, forming the anion of the oxidized ethylene copolymer, reacting the ion with acrylonitrile and subsequently derivatizing the reaction product with an amine, and U.S. Pat.
Reacting the oxidized ethylene copolymer with the amine as taught in accordance with the amination procedure of No. 3,864,268. The copolymers of the present invention can be used alone in lubricant compositions, or they can be used in combination with other viscosity index improvers. If desired, the copolymer may contain other additives, such as pour point depressants such as polymethacrylates, ashless dispersants such as the reaction product of polyisobutenyl succinic anhydride and tetraethylene pentamine, calcium nonyl sulfide phenates, etc. and dispersant-type additives such as magnesium phenyl sulfonate, zinc oxidizing agents such as dialkyldithiophosphate, etc. Moreover, the polymer of the present invention is
It is contemplated that it can be mixed with other polymers to impart various desired properties. A feature of the present invention is that significant improvements in low temperature viscosity can be achieved without undesirably affecting pour point when pour point depressants are present in the formulated oil. This improvement is due to the lubricating oil being 0.1 to 1.0% by weight.
Particular attention may be paid to the inclusion of pour point depressants, preferably in an amount of 0.4% by weight. Examples of pour point depressants that may be present in the compositions of the present invention include chlorinated wax naphthalene condensates as described in U.S. Pat. No. 2,174,246; _C10 to _C18 alkyl methacrylate polymers as described, _C10
~ _C18 Alkyl Acrylate, US Patent No. 2936300
No. and G-n- as described in No. 3048479.
Copolymer of alkyl fumarate and vinyl acetate,
Ethylene-vinyl acetate copolymer, styrene and α-
Examples include copolymers with olefins and copolymers with styrene and maleic anhydride. In the following examples, all parts are by weight unless otherwise noted. Ethylene Copolymers Containing Alkylnorbornene A series of alkylnorbornene-containing ethylene-propylene copolymers with varying ethylene and/or alkylnorbornene or ethylnorbornene contents were prepared. These copolymers (of which there are six examples) are hereinafter referred to as EPEN-1 to 6. These EPEN copolymers are prepared from ethylene, propylene and ethylnorbornene by varying the feed ratio of these three components in a polymerization process conducted essentially as follows (EPEN-5 copolymers). Combines are manufactured under these specific conditions; all parts are by weight).
That is, 3.2 parts of ethylene, 4.7 parts of propylene, 0.82 parts of ethylnorbornene and
235×(10 ⁻⁷ ) parts of hydrogen were introduced into the reactor. The catalyst composition was characterized by a molar ratio of Al/V=5. The residence time was approximately 20 minutes. The polymerization temperature was 28°C and the pressure was 60 psig. The solvent-free ethylene copolymers of the present invention were produced by steam distillation. Copolymers EPEN1-4 and 6 are
Produced by appropriate variation of feedstock ratios. The specific composition is shown below.

Table: Ethylene Propylene Copolymers For comparison purposes, a series of ethylene-propylene copolymers with varying ethylene contents were used.
These four commercially available copolymers, made generally in accordance with U.S. Pat. No. 3,697,429, have the following compositions and are hereinafter referred to as EPC-1-4.

[Table] Example 1 In this example, an oil blend exhibiting the characteristics of a reference oil containing a copolymer of the present invention, ie EPEN16, was compared with a prior art ethylene-propylene copolymer, ie EPC-1.
-4. The reference oil is a mixture of 300N and 150N base oils mixed with approximately 0.25% by weight active ingredient (AI) commercially available alkyl fumarate/vinyl acetate copolymer pour point depressant. Table 1 illustrates the effect of both types of ethylene copolymers on a blend exhibiting the characteristics of the reference oil when enough copolymer is added to give a 98.9°C viscosity of approximately 124 centistokes. do.

[Table] Comparison of pour points for oil blends G-J shows that when the pour point is maximum, there is a characteristic model ethylene content weight percent of the ethylene copolymer improver (about 57.5 weight percent ethylene for this reference oil). (in %)
The teachings of US Pat. No. 3,697,429 are illustrated.
This result is believed to occur at least in part because the ethylene-propylene copolymer improver interferes with the action of conventional lubricating oil pour point depressants.
In contrast, the pour points of oil blends A-F illustrate the benefits of the ethylene copolymers of the present invention over prior art ethylene-propylene copolymer improvers. Ethylene copolymer i.e. EPEN1~6
It is clear that none of the above interactions cause an increase in pour point as a function of the ethylene content; in fact, a comparison between EPEN-6 and EPC-1 (both containing approximately 58% by weight) (with ethylene content) exhibits a pour point improvement of approximately 35〓. Example 2 This example again compares the effects of the inventive copolymer and a prior art ethylene-propylene copolymer on a blend exhibiting the characteristics of other base stocks containing the pour point depressant of Example 1. For this purpose, the reference oil of Example 1 was replaced with a Solvent 150N high pour point base stock.

【table】

[Table] Table 2 again shows that the ethylene-propylene copolymer improver improves the pour point of nominally pour point depressed base stocks (comparing oil blend-G' to oil blend-K''). In contrast, the ethylene copolymers of the present invention generally (with the exception of EPEN-G) do not interfere with the action of conventional lubricating oil pour point depressants. By comparison (both with improvers containing 53% by weight ethylene), the ethylene-propylene copolymer adversely affects the pour point of the blend by increasing it by at least 30%, but this EXAMPLE 3 In this example, the ethylene copolymers of the present invention are shown to have no interference (with a blend pour point benefit of at least 30% for the same ethylene content copolymers when practicing the present invention). 0.15% by weight pour point depressant and 9% by weight
+15 detergent inhibitor package mixed with
Figure 2 illustrates the commercial utility of the present invention in a commercially available base stock corresponding to a Pennsylvania oil having a pour point. The resulting 10W/40 multigrade blend was prepared by adding enough improver to give a 98.9°C viscosity of about 15 centistokes. The results are shown in Table 3.

EXAMPLE 4 In this example, an ethylene copolymer of the invention was oxidatively and mechanically degraded by mastication in air without gel formation. In contrast, mastication of Vistalon 2504 and Nordel 1320 in air under similar conditions resulted in gel formation as seen in Table 4.

[Table] Example 5 As an illustration of the process for producing the aminated derivatives of oxidized ethylene copolymers of the present invention, the air masticated ethylene-propylene-ethylnorbornene copolymer of Example 4 was dissolved in solvent 100N oil. It was possible to dissolve up to 7% by weight. 0.7 g of this oil solution while stripping with nitrogen.
g of tetraethylenepentamine at 160° C. for 2 hours. The product copolymer had not only improved properties but also sludge dispersion activity.

Claims (1)

[Claims] 1. A large amount of lubricating oil with an ethylene content of about 26-79% by weight, about 1.0-25% by weight of _C1 - _C21 alkylnorbornel, and the remainder at least one C3 _- C. ₁₈ α―
A viscosity index-enhancing dose of an oil-soluble, oxidatively and mechanically degraded ethylene copolymer having an olefin having a number average molecular weight of at least 5000 (
n), 8 as measured by the ratio of weight average molecular weight (w) to log average molecular weight (w/n).
0.005 to 6 weight based on the total weight of the copolymer and a thickening ratio in the range of 1.0 to 3 when compared to polyisobutylene having a viscosity average molecular weight (v) of 20,000. A lubricating oil composition comprising: an ethylene copolymer having an oxygen content of %. 2 Ethylene copolymer is smaller than 6 (w/
2. The lubricating oil composition of claim 1, wherein the lubricating oil composition has an (n) ratio of about 1.2 to 2.4, an (n) of about 10,000 to 70,000, and an oxygen content of about 0.05 to 3% by weight. 3. The higher α-olefin is propylene, the alkylnorbornene is ethylnorbornene, and the composition contains at least a pour point depressing dose of a lubricating oil pour point depressant. The lubricating oil composition according to any one of the above. 4 Claims 1 to 3 in which the copolymer is reacted with an amount of an amine compound selected from the group consisting of nitrogen compounds having the following general formula:
The composition according to any of paragraphs. [Formula] [Formula] and [Formula] In the above formulas, R, R' and R'' are respectively hydrogen, a C ₁ to C ₂₅ straight or branched alkyl group,
_C1 - _C12 alkoxy _C2 - _C6 alkylene group, _C2-
selected from the group consisting of _C12 hydroxyalkylene group, _C2 - _C12 aminoalkylene group, _{C1 - C12} alkylaminoC2- _C6 alkylene group, and Z is O or
NG, G is from the group consisting of hydrogen and Ω aminoalkylene groups of 1 to 3 carbon atoms, s is a base of 2 to 6, t is a base of 0 to 10, and p is an integer from 1 to 4 sufficient to provide a copolymer nitrogen content of about 0.01 to 0.5% by weight. 5. The composition of claim 4, wherein the amine compound is an alkylene polyamine containing 2 to 6 nitrogens per molecule. 6. The ethylene copolymer has an ethylene content of about 26-79% by weight, a _C3 - _C18 alpha-olefin of about 20-79% by weight, and an alkylnorbornene of about 1-25% by weight, and a thickening ratio of greater than 3.0. The composition according to any one of claims 1 to 5, which is a reaction product obtained by masticating an ethylene copolymer having an ethylene copolymer in air.