JP2006083382A - Improved viscosity control agent for lubricant oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an improved lubricant oil, lubricant oil composition and additives therefor, and lubricated parts and engines, and also to provide a method for lubricating movable parts. <P>SOLUTION: The lubricant oil composition comprises a lubricating viscous base oil and about 5-30 wt.% of an additive containing a shear stable olefin copolymer derived from a copolymer having a number average molecular weight of about 50,000-250,000. The shear stable olefin copolymer has about 40 or lower shear stability index, a multi-dispersibility of about 1.5 or lower, a concentration efficacy of about 1.8 or more, and it can improve a viscosity index of the composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  A lubricating oil, lubricating oil composition and lubricating oil additive, lubricated parts and engine, and method for lubricating moving parts are disclosed below.

  Lubricating oils used in the crankcases of gasoline and diesel engines include natural and / or synthetic base stocks and one or more additives to provide the properties required for the lubricating oil. In general, such additives include ashless dispersants, metal detergents, antioxidants, and antiwear agents, which can be mixed into a package type additive. Such an additive is sometimes called a DI package (detergent inhibitor package).

  Multigrade oils typically further contain one or more friction modifiers that are relatively long chain polymers. Such polymers can be multi-functionalized to provide other characteristics and are known as multi-functional friction modifiers, but have the effect of improving viscosity characteristics primarily over a range of desired operating temperatures. is there. The viscosity modifier increases the viscosity at a high temperature without excessively increasing the viscosity at a low temperature, and has an effect of further protecting the engine at a high speed. Increased viscosity at low temperatures makes it difficult to start a cold engine. Performance at high temperatures is typically measured using kinematic viscosity (kV) (ASTM D445) at 100 ° C., and performance at low temperatures is measured by cold cranking simulator (CCS) viscosity (ASTM D2602). ASTM D5293), a mini-rotary viscometer (MRV: ASTM D4684), or a scanning Brookfield or gel index (ASTM D5133).

  The viscosity classification is defined by the classification method (SAE J300) of SAE (Society of Automotive Engineers) based on the above-described measurement results by temperature. Multigrade oils meet both low and high temperature performance requirements and display both corresponding classifications.

  Shear stability is a measure of the resistance to permanent viscosity loss when the oil is subjected to a large shearing action-the better the oil's shear stability, the lower the viscosity when subjected to shearing action. Few. Polymeric viscosity modifiers significantly improve kV at 100 ° C., but are not necessarily excellent in shear stability. Such polymeric viscosity modifiers are characterized by a shear stability index (SSI).

  Oils or additives that exhibit relatively good shear stability have a relatively low SSI. In general, high molecular weight polymers used in lubricating oils have low shear stability (ie, high SSI). However, viscosity modifiers having a relatively low SSI require a high processing concentration due to their relatively low molecular weight, thus leading to an increase in total formulation cost. Multigrade oils often have low shear stability unless expensive viscosity modifiers with low SSI are used. When the shear stability is low, it is necessary to mix a plurality of oils to improve the kV at 100 ° C., but there is a possibility that the fuel consumption may be reduced by mixing the oils. Therefore, it is necessary to improve the viscosity modifier in order to obtain a viscosity modifier that is relatively excellent in shear stability and used at lower cost.

Outline of the embodiment

  In one embodiment herein, a lubricating surface is presented. Lubricating surface is an additive comprising a shear-stable olefin copolymer, derived from a base oil of lubricating viscosity and a copolymer having a number average molecular weight in the range of about 50,000-250,000, about 5-30 Coating with a thin film of a lubricating oil composition containing: The shear stable olefin copolymer has a shear stability index of less than about 40, a polydispersity of about 1.5 or less, and a thickening efficiency of greater than about 1.8.

In another embodiment, a vehicle having a moving part and containing lubricating oil for lubricating the moving part is presented. The lubricating oil is an additive comprising a shear stable olefin copolymer, derived from an oil of lubricating viscosity and a copolymer having a number average molecular weight in the range of about 50,000 to 250,000, about 5-30 wt. %. The shear stable olefin copolymer has a shear stability index of less than about 40, a polydispersity of about 1.5 or less, and a thickening efficiency of greater than about 1.8.

  In yet another embodiment, a method for lubricating a moving part is presented. The method includes contacting the moving part with a lubricating oil composition containing a lubricating oil additive. The lubricating oil additive is a shear stable olefin copolymer, from about 5 to 95, derived from a diluent or carrier oil and a copolymer having a number average molecular weight in the range of about 50,000 to 250,000. Weight percent. The shear stable olefin copolymer has a shear stability index of less than about 40, a polydispersity of about 1.5 or less, and a thickening efficiency of greater than about 1.8. The lubricating oil composition contains about 5-30% by weight of the additive with respect to the total amount of the lubricating oil composition.

  In yet another embodiment, a method for improving the viscosity index of a lubricating oil composition is disclosed. The method comprises adding about 5-30% by weight of an additive comprising a shear stable olefin copolymer, derived from a copolymer having a number average molecular weight in the range of about 50,000 to 250,000, to a lubricating oil composition. Mixing with the product. The shear stable olefin copolymer has a shear stability index of less than about 40, a polydispersity of about 1.5 or less, and a thickening efficiency of greater than about 1.8.

  As described herein, the shear-stable copolymer is excellent in that the concentration efficiency is improved even when the addition amount is small. The shear-stable copolymer is also superior in that it can be made using a non-crystalline ethylene-containing lower copolymer such as a copolymer containing ethylene in the range of about 40 to 55% by weight. In addition to shear-stable olefin copolymers, the present invention can also be applied to shear-stable star polymers having a styrene-isoprene structure.

  Additional features and advantages of the embodiments will be apparent from the detailed description of the preferred embodiments, taken in conjunction with the following drawings. In the drawings, the reference numbers used are common among a plurality of drawings.

Detailed description of the preferred embodiment

In this specification, the terms "hydrocarbyl substituent" or "hydrocarbyl group" are used in a commonly used meaning and are well known to those skilled in the art. Specifically, it refers to a group having a carbon atom that is directly added to the rest of the molecule and that exhibits overwhelming hydrocarbon character. Examples of hydrocarbyl groups include the following:
(1) Hydrocarbon substituents, ie aliphatic (eg alkyl or alkenyl) substituents, alicyclic (eg cycloalkyl, cycloalkenyl) substituents, and aromatic, aliphatic and alicyclic substituted aromatics Substituents. In addition, cyclic substituents in which the ring is closed at another part of the molecule (eg, two substituents combine to form an alicyclic radical);
(2) Substituted hydrocarbon substituents, that is, substituents containing groups other than hydrocarbons, and in this specification, substituents that do not change the properties of groups that are predominantly hydrocarbon-like (for example, halo (Especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkyl mercapto, nitro, nitroso and sulfoxy);
(3) Hetero substituent, that is, a substituent that contains an atom other than carbon in a ring or chain consisting of carbon atoms while exhibiting overwhelming hydrocarbon properties in the present specification. Heteroatoms include sulfur, oxygen, nitrogen, and cyclic substituents such as pyridyl, furyl, thienyl and imidazolyl. Generally, there are no more than 2 and preferably no more than 1 substituent per hydrocarbon atom per 10 carbon atoms in the hydrocarbyl group, typically in the hydrocarbyl group a substituent other than hydrocarbon. Does not exist.

All embodiments of the present invention provide specific lubricating oil components, or additives. This additive is generally called a multifunctional viscosity index modifier. Specifically, the lubricating oil additive comprises a shear stable olefin copolymer derived from a copolymer having a number average molecular weight in the range of about 15,000 to about 500,000 or more. The shear stable olefin copolymer can have a shear stability index of less than about 40 and a polydispersity of about 1.5 or less. As described herein, the shear stable olefin copolymer is dissolved in a suitable solvent such as Solvent Neutral 150 to obtain the additive component.

  A wide variety of copolymers and terpolymers can be used as starting materials to form the shear stable copolymers of the present invention. The copolymers of the present invention typically refer to olefin copolymers, but the disclosed embodiments can also be applied to copolymers derived from styrene-isoprene. The copolymers of the present invention generally have a number average molecular weight of about 15,000 to 500,000, preferably about 20,000 to 300,000, more preferably about 100,000 to 200,000. The shear-stable copolymer of the present invention usually has a narrow range of molecular weight, which is determined as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (hereinafter referred to as polydispersity). . Suitable polydispersities of olefin copolymers are less than 10, preferably less than 7, and more preferably 4 or less. The Mn and Mw / Mn of the copolymer are measured by the well-known methods of vapor pressure osmometry (VPO: vapor phase osmometry), membrane osmometry, and gel permeation chromatography. The shear-stable copolymers of the present invention derived from olefin copolymers can have a polydispersity of about 1.5 or less.

  Usually, shear-stable copolymers having a narrow range of molecular weight can be obtained by mechanical shearing at relatively low temperatures. Conventional copolymer shearing processes provide extrusion shear at temperatures above about 100 ° C (212 ° F). In contrast, the copolymer shear process of the present invention is performed in a homogenizer at temperatures below about 100 ° C (212 ° F), typically from about 35 ° C (95 ° F) to 85 ° C (135 ° F). ). Thus, the expression “relatively low temperature” means a temperature that is lower than the temperature used in the extrusion shear method (conventional method) for shearing the copolymer.

The homogenizer used in this method is not limited as long as it can generate a pressure exceeding 500 pounds per square inch (35 kg / cm ² ). Within such a homogenizer, a strong shearing action will be exerted on the product when the pressure is released. Typical homogenizers that can be used are conventional homogenizers used to homogenize dairy products and to prepare emulsions used as abrasives, cosmetics, pharmaceuticals and liquid detergents. The copolymer can be sheared by treating the copolymer with a homogenizer a plurality of times (for example, about 2 to 10 times).

Olefin copolymers sheared in a homogenizer include ethylene and cyclic, alicyclic and acyclic compounds containing 3 to 28 carbon atoms (eg 2 to 18 carbon atoms). It can be prepared from ethylenically unsaturated hydrocarbons. The ethylene copolymer can contain ethylene in an amount of about 15-90% by weight, preferably about 30-80% by weight, most preferably less than about 70% by weight. Furthermore copolymer, about 10 to 85 wt%, preferably in an amount of 20 to 70 wt%, one or more _C 3 _{-C 28,} preferably _C 3 _{-C 18,} more preferably _C 3 -C It can contain ₁₀ unsaturated hydrocarbons, preferably α-olefins.

  Most preferred is a copolymer of ethylene and propylene. However, there are other α-olefins that can form copolymers instead of propylene, or α-olefins that can be used in combination with ethylene and propylene to form terpolymers and quaternary polymers. Examples include, but are not limited to, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and the like, and 4-methyl-1-pentene, 4- Examples thereof include branched α-olefins such as methyl-1-hexene, 5-methylpentene-1,4,4-dimethyl-1-pentene, and 6-methylheptene-1, and mixtures thereof.

In this specification, the term “copolymer”, unless stated otherwise, _{consists of} ethylene and C 3 _-28 α-olefins and / or non-conjugated diolefins or mixtures of those diolefins that can be used 3. Including terpolymer, quaternary polymer, copolymer and the like. Such materials can contain some amount of other olefinic monomers as long as the basic characteristics of the olefin copolymer of the present invention are not physically altered. The amount of non-conjugated diolefin is generally in the range of about 0.5 to 20 mole percent, preferably about 1 to 7 mole percent, based on the total amount of ethylene and α-olefin present.

  Typical examples of non-conjugated dienes that can be included in the terpolymer include the following: linear acyclic such as 1,4-hexadiene, 1,5-heptadiene, 1,6-octadiene Dienes; branched acyclic dienes such as 5-methyl-1,4-hexadiene, 3,7-dimethyl-1,6-octadiene, 3,7-dimethyl-1,7-octadiene; dihydromyrcene and Dihydrocymene isomer mixture; 1,4-cyclohexadiene, 1,5-cyclooctadiene, 1,5-cyclododecadiene, 4-vinylcyclohexene, 1-allyl-4-isopropylidenecyclohexane, 3-allyl Monocyclic alicyclic dienes such as cyclopentene, 4-allylcyclohexene, 1-isopropenyl-4- (4-butenyl) cyclohexane; 4,4-disi Bimonocyclic alicyclic dienes such as lopentenyl diene and 4,4-dicyclohexenyl diene; such as tetrahydroindene, methyltetrahydroindene, dicyclopentadiene, bicyclo [2.2.1] hepta-2,5-diene Polycyclic alicyclic fused and bridged ring dienes; ethyl norbornene, 5-methylene-6-methyl-2-norbornene, 5-methylene-6,6-dimethyl-2-norbornene, 5-propenyl-2-norbornene, 5 -(3-Cyclopentenyl) -2-norbornene, 5-cyclohexylidene-2-norbornene, alkyl such as norbornadiene, alkenyl, alkylidene, cycloalkenyl and cycloalkylidene norbornene.

  Specifically, the shear stable olefin copolymer may be derived from a multi-monomer polymerization reaction product such as ethylene-propylene, ethylene-propylene-diene, styrene-neoprene, styrene-isoprene.

The ethylene-propylene or higher α-olefin copolymer is composed of about 15 to 80% by weight of ethylene and about 85 to 20% by weight of C _{3 to} C ₂₃ α-olefin. These proportions are preferably about 35 to 75% by weight of ethylene, about 65 to 25% by weight of C _{3 to} C ₂₃ α-olefin, more preferably about 50 to 70% by weight of ethylene, C _{3 to} C ₂₃ α. - olefin of about 50 to 30 wt%, and most preferably ethylene about 55 to 65 _wt%, C 3 _{-C 23} alpha-olefin is about 45 to 35 wt%.

  Furthermore, the olefin copolymers for making the shear-stable olefin copolymers described herein also include olefin copolymers that have been functionalized by free radical grafting or graft polymerization. Such graft copolymers themselves are well known to those skilled in the art.

  The graft monomer for imparting a functional group to the olefin copolymer is a derivative of an olefinic unsaturated carboxyl group-containing monomer such as maleic anhydride, acrylic acid, methacrylic acid, or an ester thereof. These are also well known to those skilled in the art. Generally, acrylic acid and methacrylic acid derivatives contain 4 to 16 carbon atoms. Particularly preferred acrylic or methacrylic graft monomers include glycidyl methacrylate, methacrylate, methyl methacrylate, ethyl methacrylate, aminopropyl methacrylate, and acrylamide.

  Vinylamines containing 2 to 25 carbon atoms (preferably heterocyclic vinylamines) are another type of grafting monomer that can be used to impart functional groups to olefin copolymers. Such amines themselves are known as functionalized graft monomers and include allylamine, N-vinyl pyridine, N-vinyl pyrrolidone, vinyl lactam, vinyl carbazole, vinyl imidazole, and vinyl thiazole, specific examples 2-vinylpyridine, N-vinylpyrrolidone, vinylcaprolactam, 1-vinylimidazole, allylamine, 4-methyl-5-vinylthiazole, and 9-vinylcarbazole. Such graft monomers are described in detail in US Pat. No. 4,340,689, which is incorporated herein by reference.

Those skilled in the art will appreciate that other vinyl monomers described in the prior art documents as suitable for imparting functional groups to the olefin copolymer can also be used in the practice of this invention. Will. Such further vinyl compounds are vinyl silane and vinyl benzyl halide, and specific examples include vinyl trimethoxy silane, vinyl diethyl chloro silane, vinyl benzyl chloride and the like. Suitable silane grafting monomers are described in more detail in US Pat. No. 4,340,689, which is incorporated herein by reference.

The shear stable olefin copolymers described herein are conveniently incorporated into the lubricating oil composition. The shear stable olefin copolymer can be added directly to the lubricating oil composition. However, in some embodiments, a substantially inert, usually liquid, such as mineral oil, synthetic oil (eg, an ester of a dicarboxylic acid), naphtha, alkylated (eg, C ₁₀ -C ₁₃ alkyl) benzene, toluene, or xylene. The copolymer is diluted with an organic dilution of to form an additive concentrate. Shear stable olefin copolymer concentrates usually contain about 0-99% by weight diluent oil.

  In the preparation of lubricating oil formulations, it is common to introduce the additive in the form of a concentrate having from 1 to 99% by weight of the active ingredient in a hydrocarbon oil such as a mineral-based lubricating oil or other suitable solvent. It is a method. Usually, 0.05 to 10 parts by weight of lubricating oil per 1 part by weight of package type additive (additive package) is added to these concentrates to obtain a finished product of lubricating oil such as crankcase motor oil. As a matter of course, the concentrate is used for the purpose of facilitating dissolution or dispersion in the final mixture and reducing the complexity associated with handling various materials.

  Lubricating oil compositions prepared using the above shear stable olefin copolymers are used in a very wide range of applications. For compression ignition and spark ignition engines, it is preferred that the lubricating oil composition meets or exceeds the published GF-4 or API-CI-4 standards. Lubricating oil compositions based on the above GF-4 or API-CI-4 standards contain a base oil and a lubricating oil package type additive to provide a finished lubricating oil. The base oil of the lubricating oil disclosed herein is an oil of lubricating viscosity selected from natural lubricating oils, synthetic lubricating oils, and mixtures thereof. Such base oils include those conventionally used as crankcase lubricants for spark ignition and compression ignition internal combustion engines such as automotive and truck engines and marine and railroad diesel engines. Is included.

  Natural oils include animal and vegetable oils (eg, castor oil, lard oil), liquid petroleum and paraffinic, naphthenic, and mixed paraffin-naphthenic hydrorefining, solvent treatment, or acid treated mineral oils . Oils of lubricating viscosity obtained from coal or shale are also useful base oils. Synthetic lubricating oils used in the present invention include any of a number of commonly used synthetic hydrocarbon oils, including, but not limited to, poly-α-olefins, alkylated aromatics. , Alkylene oxide polymers, interpolymers, copolymers, derivatives thereof whose terminal hydroxyl groups have been modified by esterification and etherification, esters of dicarboxylic acids, and oils of silicon.

  The finished lubricants, as before, contain package-type additives, referred to herein as dispersant / inhibitor packages or DI packages, which give the required properties to the formulation. It is done. Suitable DI packages are described, for example, in US Pat. Nos. 5,204,012 and 6,034,040. Additives included in package-type additives include detergents, dispersants, friction modifiers, seal swell agents, antioxidants, antifoaming agents, lubricants, rust inhibitors, corrosion inhibitors, solutions Emulsifiers, viscosity index improvers and the like. Some of these components are well known to those skilled in the art and are desirably used in conventional amounts with the additives and compositions described herein.

For example, the ashless dispersant includes an oil-soluble polymeric hydrocarbon skeleton having a functional group capable of binding to the particles to be dispersed. Typically, such dispersants comprise an amine, alcohol, amide or ester polar moiety that is attached to the polymer backbone, often through groups that can be cross-linked. Ashless dispersants include, for example, oil-soluble salts, esters, aminoesters, amides, imides and oxazolines of long-chain hydrocarbon-substituted mono- and dicarboxylic acids or anhydrides; thiocarboxylate derivatives of long-chain hydrocarbons; polyamines Can be selected from Mannich condensation products formed by condensing long chain substituted hydrocarbons with formaldehyde and polyalkylene polyamines.

Antioxidants or antioxidants reduce degradation during use of the base stock. The degradation is observed as oxidation products such as sludge and metal surface varnish-like precipitates, as well as increased viscosity. Such antioxidants include phenols having sterically hindered groups, preferably alkaline earth metal salts of alkylphenol thioesters having C _{5 to} C ₁₂ alkyl side chains, calcium nonylphenol sulfides, ashless oil-soluble phenates and sulfides. Examples include phenates, phosphorus and sulfur, or hydrocarbons bonded with sulfur, phosphate esters, metal salts of thiocarbamic acid, and oil-soluble copper compounds described in US Pat. No. 4,867,890.

  Rust inhibitors selected from the group consisting of nonionic polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, and anionic alkyl sulfonic acids can be used.

  A small amount of demulsifier can be used. A preferred demulsifying component is described in EP 330,522. This is obtained by reacting an alkylene oxide having an addition product obtained by reacting a bis-epoxide with a polyhydric alcohol. The demulsifier must be used at a concentration where the active ingredient does not exceed 0.1% by weight. A treatment concentration of 0.001 to 0.05 mass% active ingredient is convenient.

Pour point depressants, also known as lube oil flow improvers, have the effect of lowering the minimum temperature at which the fluid flows, i.e. the fluid can be poured. Such additives are well known. Representative examples of additives that improve the low temperature fluidity of the fluid include C _{8 to} C ₁₈ dialkyl fumarate / vinyl acetate copolymers and polyalkyl methacrylates.

  Foaming can be suppressed by many compounds including anti-foaming agents such as silicone oil or polydimethylsiloxane.

  Furthermore, for example, seal swell agents described in US Pat. Nos. 3,794,081 and 4,029,587 can be used.

  In use, each of the above additives is used in an amount that exhibits a function, and imparts desired characteristics to the lubricating oil. Thus, for example, when the additive is a corrosion inhibitor, the amount that exerts the function of the corrosion inhibitor is an amount sufficient to impart the desired corrosion prevention properties to the lubricating oil. Generally, the concentration of each of these additives is, in use, an upper limit of about 20% by weight with respect to the weight of the lubricating oil composition. With respect to the weight of the lubricating oil composition, in one embodiment about 0.001 to 20% by weight, and in another embodiment about 0.01 to 10% by weight.

Four finished lubricating oil compositions were prepared and the viscosity and shear strength of these compositions were compared. Each lubricating oil composition contained 11% by weight conventional DI package based on the lubricating oil composition. The DI package contained conventional amounts of detergents, dispersants, anti-wear additives, friction modifiers, antifoam agents, and antioxidants. In addition, these formulations contained about 0.1% by weight pour point depressant, about 58-64% by weight 150 solvent-based neutral oil, about 12-18% by weight 600 solvent-based neutral oil. From samples 1 to 3, the characteristics of an olefin copolymer commercially available as a friction modifier can be obtained. Sample 4 provides the properties of a shear stable olefin copolymer made according to the present invention.
The following abbreviations are used in the table.

VII ... viscosity index improver
KV: kinematic viscosity (kinematic viscosity)
CCS: Cold cranking simulator
MRV—Mini rotary viscometer—performed in accordance with ASTM D4684 HTHS—High temperature high shear—ASTM D-4683, D-4781, and Tested according to D-5481

  As shown in Tables 1 and 2 above, Sample 4 is a very good viscosity modifier. Compared to samples 1 to 3, sample 4 has the least amount of polymer in the lubricating oil composition (1.32 versus 1.38 to 1.69 for samples 1 to 3). Furthermore, Sample 4 had the highest shear stability index (SSI) and passed the MRV test and the CCS test. On the other hand, Sample 3 failed the MRV test and the viscosity reduction test. Overall, Sample 4 showed a viscosity and shear strength that exceeded the commercially available ethylene-based olefin copolymer product.

  Ethylene-propylene copolymer having a number average molecular weight of 179,192 and a weight average molecular weight of 332,930 measured by gas phase chromatography (GPC) to make a shear stable olefin copolymer according to the present invention 10 parts by weight of the coalescence and 90 parts by weight of working oil were mixed. This mixture of oil and copolymer was treated 1 to 10 times with a GAULIN homogenizer to obtain a shear stable olefin copolymer having a polydispersity of less than 1.5.

The characteristics of the olefin copolymer after 0 to 10 treatments with the homogenizer are shown in the following table and FIGS. 4 and 5 show the olefin copolymer after treatment 0 to 10 times, HiTEC ^(R) 5748 and LUBRIZOL 7077 (LZ 7077) (sample 6 and sample 7 respectively) with respect to the concentration efficiency and kinematic viscosity. It is the graph compared. The comparison was performed using a 1% olefin copolymer in a control oil having the viscosity shown in the table. The kinematic viscosity at 100 ° C. of the sample was evaluated by a thermogravimetric analysis (TGA) method by dissolving 1% by weight of each sample in a control oil of about 5 cSt (FIG. 4).

  As shown in the above table and FIGS. 1 to 5, the shear-stable copolymer prepared by treating the copolymer 10 times or more with a homogenizer has viscosity adjustment that satisfies the standard value (about 23) of the shear stability index. The sample (sample 5) can be used as an additive, and clearly has a higher concentration efficiency (sample 5) than the conventional olefin copolymer viscosity modifiers (samples 6 and 7). Mechanical shearing also has the advantage that a shear-stable olefin copolymer (sample 5 in FIG. 3) having a polydispersity of less than 1.5 can be obtained.

  At various places throughout this specification, reference has been made to a number of US patents. It is noted that all of these references are incorporated herein in their entirety.

  The above embodiment can be considerably changed in actual situations. Thus, embodiments are not limited to the specific examples described above. The above embodiments are within the spirit and scope of the present invention, including equivalents under the patent law.

  Applicants did not disclose any embodiment for general provision, and even if changes or modifications to the disclosure do not literally fall within the scope of the claims, they are And is considered to be part of the claims.

The main aspects and features of the present invention are as follows.
1. Contains a base oil of lubricating viscosity and an additive comprising a shear-stable olefin copolymer derived from a copolymer having a number average molecular weight in the range of about 50,000 to 250,000, about 5-30% by weight A lubricating surface comprising a coating of a lubricating oil composition with a thin film, wherein the shear stable olefin copolymer has a shear stability index less than about 40, a polydispersity of about 1.5 or less, and about 1. A lubricating surface having a thickening efficiency greater than 8 (where the amount of additive in the lubricating oil composition is relative to the total amount of the lubricating oil composition).
2. The lubricated surface according to 1 above, wherein the lubricated surface comprises a power transmission path of the engine.
3. The lubricating surface of claim 1, wherein the lubricating surface comprises an internal surface or component of an internal combustion engine.
4). The lubricated surface of claim 1, wherein the lubricated surface comprises an internal surface or component of a compression ignition engine.
5. A shear-stable copolymer comprising an ethylene-propylene monomer combination, an ethylene-propylene-diene monomer combination, a styrene-isoprene monomer combination, and a styrene-neoprene monomer combination The lubricating surface of claim 1, wherein the lubricating surface is derived from the group consisting of:
6). The lubricating surface of claim 1, wherein the shear-stable copolymer is derived from a copolymer that is homogenized at a relatively low temperature.
7). The lubricating surface of claim 1, wherein each monomer unit of the shear-stable copolymer each contains about 2 to 10 carbon atoms.
8). The lubricated surface of claim 1, wherein the shear-stable copolymer comprises a copolymer comprising amorphous ethylene and the ethylene content is less than about 70% of the weight of the copolymer.
9. An automobile comprising the lubricating surface according to 1 above.
10. A transportation means having a movable part and containing a lubricating oil for lubricating the movable part, wherein the lubricating oil is a base oil having a lubricating viscosity and a number average molecular weight in the range of about 50,000 to 250,000. An additive comprising a shear-stable olefin copolymer derived from a copolymer having a shear stability olefin copolymer of less than about 40, A means of transport having a polydispersity of 1.5 or less and a thickening efficiency greater than about 1.8 (where the amount of additive in the lubricating oil is relative to the total amount of lubricating oil).
11. A shear-stable copolymer comprising an ethylene-propylene monomer combination, an ethylene-propylene-diene monomer combination, a styrene-isoprene monomer combination, and a styrene-neoprene monomer combination 11. The vehicle of claim 10, wherein the vehicle is derived from a group consisting of:
12 11. A means of transportation as described in 10 above, wherein the shear stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer.
13. The vehicle of claim 10, wherein the movable part comprises a heavy duty diesel engine including an exhaust gas recirculation device and a system for lubricating the engine.
14 11. The means of transportation as described in 10 above, wherein each monomer unit of the shear-stable copolymer contains about 2 to 10 carbon atoms.
15. 11. The means of transport of claim 10, wherein the shear-stable copolymer comprises a copolymer comprising amorphous ethylene and the ethylene content is less than about 70% of the weight of the copolymer.
16. A finished lubricating oil composition comprising a base oil component of lubricating viscosity and about 5 to 30 weight percent additive, wherein the additive has a number average molecular weight in the range of about 50,000 to 250,000. A shear-stable olefin copolymer derived from the copolymer having a shear stability olefin copolymer of less than about 40, a polydispersity of about 1.5 or less, and about 1. A finished lubricating oil composition having a thickening efficiency greater than 8, wherein the amount of additive in the lubricating oil composition is relative to the total amount of the lubricating oil composition.
17. A shear-stable copolymer comprising an ethylene-propylene monomer combination, an ethylene-propylene-diene monomer combination, a styrene-isoprene monomer combination, and a styrene-neoprene monomer combination The lubricating oil composition of claim 16, derived from the group consisting of:
18. 17. The lubricating oil composition of claim 16, wherein the shear stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer.
19. 17. The lubricating oil composition as described in 16 above, wherein each monomer unit of the shear-stable copolymer contains about 2 to 10 carbon atoms.
20. The lubricating oil composition of claim 16, wherein the shear stable copolymer comprises a copolymer comprising amorphous ethylene and having an ethylene content of less than about 70% by weight.
21. A method of improving the viscosity index of a lubricating oil composition comprising the step of mixing the lubricating oil composition with about 5 to 30 weight percent additive, wherein the additive is in the range of about 50,000 to 250,000. A shear-stable olefin copolymer derived from a copolymer having a number average molecular weight, wherein the shear-stable olefin copolymer has a shear stability index of less than about 40 and a polydispersity of about 1.5 or less. A thickening efficiency greater than about 1.8 (where the amount of additive in the lubricating oil composition is relative to the total amount of the lubricating oil composition).
22. The method of claim 21, wherein the lubricating oil composition comprises a multi-viscosity lubricating oil.
23. A shear-stable copolymer comprising an ethylene-propylene monomer combination, an ethylene-propylene-diene monomer combination, a styrene-isoprene monomer combination, and a styrene-neoprene monomer combination The method of claim 21, wherein the method is derived from a group consisting of:
24. The method of claim 21, wherein the shear-stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer.
25. The method of claim 21, wherein each monomer unit of the shear-stable copolymer each contains about 2 to 10 carbon atoms.
26. The method of claim 21, wherein the shear stable copolymer comprises a copolymer comprising amorphous ethylene and having an ethylene content of less than about 70% by weight.
27. A lubricating oil additive concentrate comprising a diluent or carrier oil and about 5 to 90% by weight additive, wherein the additive has a number average molecular weight in the range of about 50,000 to 250,000. A shear-stable olefin copolymer derived from a polymer, wherein the shear-stable olefin copolymer has a shear stability index of less than about 40, a polydispersity of about 1.5 or less, and about 1.8. Lubricating oil additive concentrate having a thickening efficiency that is greater (where the amount of additive in the additive concentrate is relative to the total amount of additive concentrate).
28. A shear-stable copolymer comprising an ethylene-propylene monomer combination, an ethylene-propylene-diene monomer combination, a styrene-isoprene monomer combination, and a styrene-neoprene monomer combination 28. The additive concentrate of claim 27, derived from the group consisting of:
29. 28. The additive concentrate of claim 27, wherein the shear stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer.
30. 28. The additive concentrate as described in 27 above, wherein each monomer unit of the shear-stable copolymer each contains about 2 to 10 carbon atoms.
31. 28. The additive concentrate of claim 27, wherein the shear stable copolymer comprises a copolymer comprising amorphous ethylene and having an ethylene content of less than about 70% by weight.
32. A lubricating oil composition comprising a base oil and the additive concentrate as described in 27 above.
33. A method of lubricating a moving part of a vehicle, wherein the method uses a lubricating oil composition containing a base oil and a lubricating oil additive as a lubricating oil for one or more moving parts of the vehicle A predetermined amount of a shear-stable olefin copolymer, wherein the lubricant additive is derived from a diluent / carrier oil and a copolymer having a number average molecular weight in the range of about 50,000 to 250,000. About 5 to 30% by weight of the shear stable olefin copolymer in the lubricating oil composition, wherein the shear stable olefin copolymer has a shear stability index of less than about 40; Transportation means having a polydispersity of about 1.5 or less and a thickening efficiency greater than about 1.8 (where the amount of additive in the lubricating oil composition is relative to the total amount of the lubricating oil composition) To lubricate the moving parts of the machine.
34. A shear-stable copolymer comprising an ethylene-propylene monomer combination, an ethylene-propylene-diene monomer combination, a styrene-isoprene monomer combination, and a styrene-neoprene monomer combination 34. The method of claim 33, derived from the group consisting of:
35. 34. The method of claim 33, wherein the shear stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer.
36. 34. The method of claim 33, wherein each monomer unit of the shear stable copolymer contains from about 2 to 10 carbon atoms.
37. 34. The method of claim 33, wherein the shear-stable copolymer comprises a copolymer comprising amorphous ethylene and having an ethylene content below about 70% by weight.
38. 34. The method of claim 33, wherein the vehicle comprises a diesel engine and the moving part comprises a moving part of the engine.
39. 34. The method of claim 33, wherein the means of transportation comprises a nautical means of transportation having an engine and the moving part comprises a moving part of the engine.
40. 34. The method of claim 33, wherein the vehicle comprises a spark ignition engine and the moving part comprises a moving part of the engine.
41. 34. The method of claim 33, wherein the transportation means includes a power transmission path and the movable part includes a movable part of the power transmission path.
42. 34. The method of claim 33, wherein the vehicle comprises an internal combustion engine having a crankcase and the lubricating oil composition comprises crankcase oil present in the crankcase of the vehicle.
43. 34. The method of claim 33, wherein the lubricating oil composition comprises a power transmission line lubricant present in an automatic power transmission path of the vehicle.
44. A method of lubricating a movable part comprising the step of contacting the movable part with a lubricating oil composition containing a lubricating oil additive, wherein the lubricating oil additive is diluted with carrier oil and about 50,000-250, A shear-stable olefin copolymer derived from a copolymer having a number average molecular weight in the range of 000, from about 5 to 95% by weight, the shear-stable olefin copolymer having a shear stability index of less than about And a polydispersity of about 1.5 or less and a thickening efficiency of greater than about 1.8 (provided that the lubricating oil composition comprises about 5 to 30% by weight additive based on the total amount of the lubricating oil composition). A method of lubricating a moving part (containing).
45. 45. A method according to 44, wherein the movable part comprises a movable part of the vehicle.
46. 45. The method of claim 44, wherein the vehicle comprises a nautical vehicle having an engine and the movable part comprises a movable part of the engine.
47. 45. The method of claim 44, wherein the vehicle comprises an internal combustion engine having a crankcase and the lubricating oil composition comprises crankcase oil present in the crankcase of the vehicle.
48. 45. The method of claim 44, wherein the lubricating oil composition comprises a power transmission line lubricating oil present in an automatic power transmission path of the vehicle.

The change of the shear stability index at the time of mechanically shearing the olefin copolymer of the present invention is shown. The change of polydispersity when the olefin copolymer of the present invention is mechanically sheared is shown. It is a graph which shows the change of the viscosity at the time of carrying out mechanical shearing of the olefin copolymer of this invention. A graph comparing the viscosity change when the olefin copolymer of the present invention is mechanically sheared in working oil with the viscosity change when the conventional olefin copolymer is sheared and directly finished at high temperature by an extruder. is there. Comparison of change in concentration efficiency when the olefin copolymer of the present invention is mechanically sheared with change in concentration efficiency when the conventional olefin copolymer is sheared and directly finished at high temperature by an extruder. It is a graph.

Claims (7)

  Contains a base oil of lubricating viscosity and an additive comprising a shear-stable olefin copolymer derived from a copolymer having a number average molecular weight in the range of about 50,000 to 250,000, about 5-30% by weight A lubricating surface comprising a coating of a lubricating oil composition with a thin film, wherein the shear stable olefin copolymer has a shear stability index less than about 40, a polydispersity of about 1.5 or less, and about 1. A lubricating surface having a thickening efficiency greater than 8 (where the amount of additive in the lubricating oil composition is relative to the total amount of the lubricating oil composition).   A transportation means having a movable part and containing a lubricating oil for lubricating the movable part, wherein the lubricating oil is a base oil having a lubricating viscosity and a number average molecular weight in the range of about 50,000 to 250,000. An additive comprising a shear-stable olefin copolymer derived from a copolymer having a shear stability olefin copolymer of less than about 40, A means of transport having a polydispersity of 1.5 or less and a thickening efficiency greater than about 1.8 (where the amount of additive in the lubricating oil is relative to the total amount of lubricating oil).   A finished lubricating oil composition comprising a base oil component of lubricating viscosity and about 5 to 30 weight percent additive, wherein the additive has a number average molecular weight in the range of about 50,000 to 250,000. A shear-stable olefin copolymer derived from the copolymer having a shear stability olefin copolymer of less than about 40, a polydispersity of about 1.5 or less, and about 1. A finished lubricating oil composition having a thickening efficiency greater than 8, wherein the amount of additive in the lubricating oil composition is relative to the total amount of the lubricating oil composition.   A method of improving the viscosity index of a lubricating oil composition comprising the step of mixing the lubricating oil composition with about 5 to 30 weight percent additive, wherein the additive is in the range of about 50,000 to 250,000. A shear-stable olefin copolymer derived from a copolymer having a number average molecular weight, wherein the shear-stable olefin copolymer has a shear stability index of less than about 40 and a polydispersity of about 1.5 or less. A thickening efficiency greater than about 1.8 (where the amount of additive in the lubricating oil composition is relative to the total amount of the lubricating oil composition).   A lubricating oil additive concentrate comprising a diluent or carrier oil and about 5 to 90% by weight additive, wherein the additive has a number average molecular weight in the range of about 50,000 to 250,000. A shear-stable olefin copolymer derived from a polymer, wherein the shear-stable olefin copolymer has a shear stability index of less than about 40, a polydispersity of about 1.5 or less, and about 1.8. Lubricating oil additive concentrate having a thickening efficiency that is greater (where the amount of additive in the additive concentrate is relative to the total amount of the additive concentrate).   A method of lubricating a moving part of a vehicle, wherein the method uses a lubricating oil composition containing a base oil and a lubricating oil additive as a lubricating oil for one or more moving parts of the vehicle A predetermined amount of a shear-stable olefin copolymer, wherein the lubricant additive is derived from a diluent / carrier oil and a copolymer having a number average molecular weight in the range of about 50,000 to 250,000. About 5 to 30% by weight of the shear stable olefin copolymer in the lubricating oil composition, wherein the shear stable olefin copolymer has a shear stability index of less than about 40; Transportation means having a polydispersity of about 1.5 or less and a thickening efficiency greater than about 1.8 (where the amount of additive in the lubricating oil composition is relative to the total amount of the lubricating oil composition) To lubricate moving parts. A method of lubricating a movable part comprising the step of contacting the movable part with a lubricating oil composition containing a lubricating oil additive, wherein the lubricating oil additive is diluted with carrier oil and about 50,000-250, A shear-stable olefin copolymer derived from a copolymer having a number average molecular weight in the range of 000, from about 5 to 95% by weight, the shear-stable olefin copolymer having a shear stability index of less than about 40 And a polydispersity of about 1.5 or less and a thickening efficiency of greater than about 1.8 (provided that the lubricating oil composition comprises about 5 to 30% by weight additive based on the total amount of the lubricating oil composition). A method of lubricating a moving part (containing).

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