KR100724328B1 - Improved Viscosity Modifiers for Lubricant Compositions - Google Patents

Abstract

A lubricant composition method using a lubricant composition. The lubricant composition contains about 5 to about 30% by weight of 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 ranging from about 50,000 to about 250,000. The shear stability index of the shear stable olefin copolymer is less than about 40, the polydispersity is less than about 1.5, the thickening efficiency is greater than about 1.8, and impart viscosity index enhancement properties to the lubricant composition.

Viscosity modifier

Description

IMPROVED VISCOSITY MODIFIERS FOR LUBRICANT COMPOSITIONS

Further features and advantages of the embodiments are evident by reference to the following detailed description of the preferred embodiments when considered in connection with the following drawings, in which the reference numerals refer to members throughout the various views, wherein

1 is a shear stability index plot of an olefin copolymer mechanically sheared according to the disclosure;

2 is a polydispersity diagram of an olefin copolymer mechanically sheared according to the disclosure;

3 is a graphical representation of olefin copolymer viscosity mechanically sheared according to the disclosure;

FIG. 4 is a graphical representation of olefin copolymers according to initiation in a process oil illustrating viscosity changes during mechanical shear as compared to conventional olefin copolymers prepared under hot extrusion shear and direct finishing processes;

FIG. 5 is a plot of the thickening efficiency of a mechanical shear olefin copolymer according to the disclosure as compared to the thickening efficiency of conventional olefin copolymers prepared under high temperature extrusion shear and direct finishing processes.

The following disclosure relates to lubricants, lubricant compositions and additives, lubricated parts and methods of lubricating engines and moving parts.

Lubricants used in gasoline and diesel crankcases include one or more additives that impart desirable properties to natural and / or synthetic basestocks and lubricants. Such additives typically include ashless dispersants, metal detergents, antioxidants, and wear resistant components, which may sometimes be combined into a package called an antifouling agent (or DI) package.

Multigrade oils usually contain one or more viscosity modifiers which are relatively long chain polymers. The polymers are known as multifunctional viscosity modifiers and may function to provide other properties, but in principle serve to improve the viscosity properties of the oil over the required operating temperature range. Viscosity modifiers serve to further protect high speed engines by increasing the viscosity at high temperatures without increasing the viscosity at low temperatures which would otherwise make it difficult to start a low temperature engine. High temperature performance is typically measured by kinematic viscosity (kV) at 100 ° C. (ASTM D445), while low temperature performance is measured by cold cranking simulator (CCS) viscosity (ASTM D26093, a revision of ASTM D2602), mini- Mini-Rotary Viscometer (MRV; ASTM D4684), or Scanning Brookfield or Gel Index (ASTM D5133).

Viscosity grades are standardized with the SAE classification system (SAE J300) according to the previous temperature measurement. Multigrade oils meet the requirements for both low temperature and high temperature performance and are therefore referenced in both corresponding grades.

Shear safety is a measure of the ability of an oil to resist permanent loss of viscosity under high shear-when the oil is sheared, the greater the shear stability of the oil, the less the viscosity loss. The shear stability of the polymeric viscosity modifier, which contributes significantly to kV 100 ° C., is not complete. The polymeric viscosity modifier is characterized by shear stability index (SSI).

 Oils or additives that exhibit relatively high shear safety have a relatively low SSI. Typically, high molecular weight polymers used in lubricating oil applications have poor shear safety (ie, high SSI). However, relatively low SSI viscosity modifiers require high throughput due to their relatively low molecular weight and thus increase the total formulation cost. Multigrade oils often have poor shear safety unless they use expensive viscosity modifiers with low SSI. Poor shear safety requires mixing the oil with a higher kinematic viscosity than the initial kV 100 ° C, which can lead to poor fuel economy. Thus, there is a need for improved viscosity modifiers that are shear stable and more cost effective when used in lubricant compositions.

Provided are improved viscosity modifiers that are shear stable and more cost effective when used in lubricant compositions.

Implementation  summary

In one embodiment of the invention, a lubricating surface is presented. The lubricating surface contains from about 5% to about 30% by weight of an additive comprising a base oil of lubricating viscosity and a shear stable olefin copolymer derived from a copolymer having a number average molecular weight ranging from about 50,000 to about 250,000. Thin film coatings of lubricant compositions. The shear stability index of the shear stable olefin copolymer is less than about 40, the polydispersity is about 1.5 or less, and the thickening efficiency is greater than about 1.8.

In another embodiment, there is provided a vehicle having a movable portion and comprising a lubricant for lubricating the movable portion. Lubricants contain about 5 to about 30 percent by weight of an additive comprising a shear stable olefin copolymer derived from an oil of lubricating viscosity and a copolymer having a number average molecular weight ranging from about 50,000 to about 250,000. The shear stability index of the shear stable olefin copolymer is less than about 40, the polydispersity is about 1.5 or less, and the thickening efficiency is greater than about 1.8.

In yet another embodiment, a moving part lubrication method is provided. The method includes contacting a lubricant composition containing a lubricant additive with a movable portion. Lubricant additives include from about 5 to about 95 weight percent olefin copolymer having shear properties derived from a diluent or carrier oil and a copolymer having a number average molecular weight ranging from about 50,000 to about 250,000. The shear stability index of the shear stable olefin copolymer is less than about 40, the polydispersity is about 1.5 or less, and the thickening efficiency is greater than about 1.8. The lubricant composition contains from about 5 to about 30 weight percent of the additive, based on the total weight of the lubricant composition.

Further embodiments of the present disclosure provide a method of improving the viscosity index of a lubricant composition. The method includes mixing with a lubricant composition containing about 5 to about 30 weight percent additives including shear stable olefin copolymers derived from copolymers having a number average molecular weight in the range of about 50,000 to about 250,000. The shear stability index of the shear stable olefin copolymer is less than about 40, the polydispersity is about 1.5 or less, and the thickening efficiency is greater than about 1.8.

An advantage of shear stable copolymers as described herein is that the polymer exhibits improved thickening efficiency at low polymer loadings. Another advantage of shear stable copolymers is that they can be formed using copolymers such as amorphous lower ethylene containing copolymers having an ethylene content in the range from about 40% to about 55% by weight. In addition to the shear stable olefin copolymer, the present disclosure may also be applied to shear stable molding polymers based on styrene-isoprene chemistry.

desirable Implementation  details

As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary meaning and is well known to those skilled in the art. Specifically, it is referred to as a group having carbon atoms directly bonded to the rest of the molecule and having primarily hydrocarbon properties. Examples of hydrocarbyl groups include the following:

(1) hydrocarbon substituents, ie aliphatic (eg alkyl or alkenyl), cycloaliphatic (eg cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and cycloaliphatic-substituted aromatic substituents as well as cyclic Substituents, wherein the ring is completed through another portion of the molecule (eg, two substituents together form an alicyclic radical);

(2) substituted hydrocarbon substituents, ie, in the context of the present description, mainly hydrocarbon substituents (eg, halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and A substituent containing a non-hydrocarbon group which does not change sulfoxy);

(3) Hetero-substituents, ie substituents which have primarily hydrocarbon properties and, in the context of the present description, contain other than carbon in a ring or chain of carbon atoms. Hetero-atoms include sulfur, oxygen, nitrogen and include substituents such as pyridyl, furyl, thienyl and imidazolyl. In general, only two, preferably only one, non-hydrocarbon substituents will be present every 10 carbon atoms of the hydrocarbyl group; Typically, the hydrocarbyl group is free of non-hydrocarbon substituents.

In all embodiments of the present disclosure, certain lubricant components or additives have been provided. Such additives are generally referred to as multifunctional viscosity index modifiers. Specifically, the lubricant 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 stability index of the shear stable olefin copolymer is less than about 40 and the polydispersity is less than about 1.5. As described herein, the shear stable olefin copolymer is dissolved in a suitable solvent such as Solvent Neutral 150 to provide the additive component.

A wide variety of copolymers and trimers can be used as starting materials for preparing shear stable copolymers. Copolymers are generally considered to be olefin copolymers, but in the disclosed embodiments can also be applied to copolymers derived from styrene-isoprene. The number average molecular weight of the copolymer is typically about 15,000 to about 500,000; Preferably from about 20,000 to about 300,000, more preferably from about 100,000 to about 200,000. Shear-safe copolymers generally have a narrow molecular weight, as measured by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), hereinafter referred to as "polydispersity". The polydispersity of suitable olefin copolymers is less than 10, preferably less than 7 and more preferably 4 or less. (Mn) and (Mw / Mn) of the copolymers are measured by well known techniques such as vapor phase osmosis (VPO), membrane osmotic pressure and gel permeation chromatography. Shear-safe copolymers derived from olefin copolymers have a polydispersity of about 1.5 or less.

In general, shear stable copolymers having a narrow range of molecular weight can be obtained by mechanical shear in a relatively low temperature phase. Conventional copolymer shearing is performed at temperatures above about 100 ° C. (212 ° F.) in an extrusion shear process. In contrast, the shearing of the copolymer according to the disclosure is carried out in a homogenizer at temperatures up to about 100 ° C. (212 ° F.), typically from about 35 ° C. (95 ° F.) to about 85 ° C. (135 ° F.). Thus, the term “relatively low temperature phase” means a temperature below the temperature in a conventional extrusion shear process for shear copolymers.

The homogenizer used in the process can be of any type capable of giving a pressure of more than 500 pounds per square inch, with the product being high sheared upon receiving the pressure. Homogenizers of dairy products and homogenizers of the type commonly used in the preparation of emulsions used as gloss compounds, cosmetics, pharmaceuticals and liquid soaps are typical of homogenizers that can be used. The copolymer can be sheared using multiple passes through the homogenizer, for example from about 2 to about 10 passes through the homogenizer.

The olefin copolymer sheared in the homogenizer can be prepared from ethylenically unsaturated hydrocarbons including ethylene and cyclic, alicyclic and acyclic compounds having 3 to 28 carbon atoms, such as 2 to 18 carbon atoms. The ethylene copolymer may comprise about 15 to about 90 weight percent ethylene, preferably about 30 to about 80 weight percent ethylene and most preferably less than about 70 weight percent ethylene. The copolymer may also contain about 10 to about 85 weight percent, preferably 20 to 70 weight percent of at least one C ₃ to C ₂₈ , preferably C ₃ to C ₁₈ , more preferably C ₃ to C ₁₀ Phosphorus unsaturated hydrocarbons, preferably alpha olefins.

Most preferred are copolymers of ethylene and propylene. However, other alpha-olefins suitable in place of propylene to form copolymers or other alpha-olefins used in combination of ethylene and propylene to form trimers, tetramers, etc. include, but are not limited to: 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-dekene, and the like; Also branched chain alpha-olefins such as 4-methyl-1-pentene, 4-methyl-1-hexene, 5-methylpentene-1, 4,4-dimethyl-1-pentene, and 6-methylheptene-1, And the like, and mixtures thereof.

The term polymer, as used herein, unless otherwise indicated, trimers, tetramers, interpolymers, etc. of C _{3 -28} alpha-olefins and ethylene that can be used and / or of non-conjugated diolefins or of such diolefins Mixtures. The material may comprise small amounts of other olefin monomers as long as the basic characteristics of the small amount of olefin copolymers do not substantially change. The amount of non-conjugated diolefin will generally range from about 0.5 to 20 mole percent, preferably from about 1 to about 7 mole percent, based on the total amount of ethylene and alpha-olefin present.

Representative examples of non-conjugated dienes that may be included in the trimer include straight chain acyclic dienes such as 1,4-hexadiene; 1,5-heptadiene; 1,6-octadiene; Branched chain acyclic dienes such as 5-methyl-1,4-hexadiene; 3,7-dimethyl 1,6-octadiene; 3,7-dimethyl-1,7-octadiene; And mixed isomers of dihydro-myrcene and dihydro-cymene; Single ring alicyclic dienes such as 1,4-cyclohexadiene; 1,5-cyclooctadiene; 1,5-cyclododecadiene; 4-vinylcyclohexene; 1-allyl-4-isopropylidene cyclohexane; 3-allyl-cyclopentene; 4-allyl-cyclohexene and 1-isopropenyl-4- (4-butenyl) cyclohexane; Multi-monocyclic alicyclic dienes such as 4,4-dicyclopentenyl and 4,4-dicyclohexenyl dienes; Multi-ring alicyclic conjugated and bridged ring dienes such as tetrahydroindene; Methyl tetrahydroindene; Dicyclopentadiene; Bicyclo (2.2.1) hepta-2,5-diene; Alkyl, alkenyl, alkylidene, cycloalkenyl and cycloalkylidene norbornene such as: ethyl norbornene; 5-methylene-6-methyl-2-norbornene; 5-methylene-6,6-dimethyl-2-norbornene; 5-propenyl-2-norbornene; 5- (3-cyclopentenyl) 2-norbornene and 5-cyclohexylidene-2-norbornene; Norbornadiene; And the like.

Specifically, the shear stable olefin copolymer may be derived from polymerization of ethylene-propylene monomer, ethylene-propylene-diene monomer, styrene-neoprene monomer, styrene-isoprene monomer and the like.

The ethylene-propylene or higher alpha-olefin copolymers may contain about 15 to about 80 weight percent ethylene and about 85 to about 20 weight percent C ₃ to C ₂₃ alpha-olefins, preferably about 35 to about 75 weight percent ethylene and about 65 to about 25 weight percent C ₃ to C ₂₃ alpha-olefin, more preferably less than about 50 to about 70 weight percent ethylene and about 50 to about 30 weight percent C ₃ to C ₂₃ alpha-olefin and most preferably About 55 to about 65 weight percent ethylene and about 45 to about 35 weight percent C ₃ to C ₂₃ alpha-olefin.

In addition, the olefin copolymer for preparing a shear-safe olefin copolymer disclosed herein includes the olefin copolymer which can be functionalized using a free radical graft reaction or a graft polymerization reaction. The graft copolymers themselves are well known to those skilled in the art.

Graft monomers for functionalizing olefin copolymers are derivatives of olefinically unsaturated carboxyl monomers, such as maleic anhydride, acrylic acid or methacrylic acid, or esters thereof, as well as graft monomers known to those skilled in the art. Typically, acrylic and methacrylic acid derivatives have 4 to 16 carbon atoms. Particularly preferred among the group of acryl or methacryl graft monomers are glycidyl methacrylate, methylacrylate, methyl methacrylate, ethyl methacrylate and aminopropyl methacrylate, and acrylamide.

Another group of graft monomers that can be used to functionalize the olefin copolymers are vinyl amines having 2 to 25 carbon atoms, and preferably heterocyclic vinyl amines. The amines are known as functionalized graft monomers and are 2-vinylpyridine, N-vinylpyrrolidone, vinyl caprolactam, 1-vinylimidazole, allylamine, 4-methyl-5-vinylthiazole and 9- Examples of vinylcarbazole include allylamine, N-vinylpyridine, N-vinylpyrrolidone, vinyl lactam, vinylcarbazole, vinylimidazole and vinylthiazole. Such graft monomers are described in detail in U.S. Patent No. 4,340,689, the disclosure of which is incorporated herein by reference.

As it is appreciated by those skilled in the art, other vinyl monomers suitable for olefin copolymer functionalization described in the prior art can likewise be used in the practice of the present invention. Examples of further such vinyl compounds are vinyl silanes and vinyl-benzyl halides, as exemplified by vinyltrimethoxysilane, vinyldiethychlorosilane, vinylbenzylchloride and the like. Further description of suitable silane graft monomers is described in U.S. Patent No. 4,340,689, the disclosure of which is incorporated herein by reference.

The shear stable olefin copolymers in the embodiments described herein are advantageously incorporated into the lubricating composition. Shear-safe olefin copolymers may be added directly to the lubricating oil composition. However, in one embodiment the copolymer is substantially inert, usually liquid organic diluents such as mineral oil, synthetic oils (eg esters of dicarboxylic acids), naphtha, alkylation (eg C ₁₀₎ C ₁₃ alkyl) diluted with benzene, toluene or xylene to form an additive concentrate. Shearsafe olefin copolymer concentrates usually comprise from about 0% to about 99% by weight diluent oil.

In the formulation of lubricating oil formulations, it is common practice to introduce additives in the form of 1 to 99% by weight active ingredient concentrate in hydrocarbon oils such as mineral oil, or other suitable solvents. Usually the concentrate may be added with 0.05 to 10 parts by weight of lubricant per part by weight of the additive package in forming the final lubricant, such as crankcase motor oil. The purpose of the concentrate is, of course, not only to facilitate the solution or dispersion of the final mixture, but also to make processing and handling of the various materials less difficult.

Lubricant compositions made from the shear stable olefin copolymers described above are widely applied. In compression ignition engines and spark ignition engines, it is desirable to exceed or meet the published GF-4 or API-CI-4 standards. Lubricant compositions according to the preceding GF-4 or API-CI-4 standards provide a fully formulated lubricant, including base oil and oil additive packages. Base oils for lubricants according to the present disclosure include oils of lubricating viscosity selected from natural lubricants, synthetic lubricants and mixtures thereof. The base oils include those used as crankcase lubricating oils for spark-ignition and compression ignition internal combustion engines, such as automobile and truck engines, ships and railway diesel engines.

Natural oils are hydrorefine, solvent-treated or acid-treated of animal and vegetable oils (e.g. castor oil, lard oil), liquid petroleum oils and paraffins, naphthenes and mixed paraffin-naphthenic types. Mineral lubricants. Oils of lubricating viscosity derived from coal or shale are also useful base oils. Synthetic lubricants used in the present invention include one of many commonly used synthetic hydrocarbon oils, including but not limited to: poly-alpha-olefins, alkylated aromatics, alkylene oxide polymers, interpolymers, copolymers And derivatives thereof, wherein the hydroxyl group ends are modified by esterification, etherification and the like, esters of dicarboxylic acids and silicon-based oils.

Fully formulated lubricants are commonly referred to herein as dispersant / inhibitor packages or DI packages and contain additive packages that will impart the properties required for formulation. Suitable DI packages are described, for example, in U.S. Patents 5,204,012 and 6,034,040. Types of additives included in the additive package include detergents, dispersants, friction modifiers, seal swell agents, antioxidants, antifoam agents, lubricants, rust inhibitors, corrosion inhibitors, anti-emulsifiers, viscosity index improvers, and the like. Some of these components are well known to those skilled in the art and are preferably used in conventional amounts with the additives and compositions described herein.

For example, ashless dispersants include fat-soluble polymeric hydrocarbon backbones with functional groups capable of binding to the particles to be dispersed. Typically, dispersants often include ester polar moieties, amines, alcohols, or amides that are bonded to the polymer backbone via a crosslinking group. Ashless dispersants include, for example, fat soluble salts, esters, amino-esters, amides, imides, and oxazolines of long chain hydrocarbon substituted mono and dicarboxylic acids or anhydrides thereof; Thiocarboxylated derivatives of long chain hydrocarbons; Long-chain aliphatic hydrocarbons having polyamines directly bonded thereto; And Mannich condensation products formed by condensing long chain substituted phenols with formaldehyde and polyalkylene polyamines.

Antioxidants or antioxidants reduce the tendency of base accumulation to reduce usability, which can be demonstrated by increased viscosity and oxidized products such as sludge and varnish on metal surfaces. Such antioxidants are alkaline earth metal salts of hindered phenols, preferably alkylphenol thioesters with C ₅ to C ₁₂ alkyl side chains, calcium nonylphenol sulfides, ashless fat-soluble phenates, as described in US Pat. No. 4,867,890. And sulfurized phenates, phosphorus sulfide or sulfide hydrocarbons, phosphorus esters, metal thiocarbamates and fat soluble copper compounds.

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

Small amounts of anti emulsifying components can be used. Preferred anti-emulsifying components are described in EP 330,522. It can be obtained by reacting alkylene oxide with an accessory obtained by reacting bis-epoxy and polyhydric alcohol. Demulsifiers should be used at levels not exceeding 0.1 mass% active ingredient. The throughput of 0.001 to 0.05 mass% active ingredient is convenient.

Pour point depressants, otherwise known as lubricant flow enhancers, lower the minimum temperature at which a fluid can flow or flow. Such additives are well known. Typical of such additives which improve low temperature fluidity of the fluid are C ₈ to C ₁₈ dialkyl fumarate / vinyl acetate copolymers, polyalkylmethacrylates and the like.

Bubble control can be provided by many compounds, including antifoams of the polysiloxane type, such as silicone oil or polydimethyl siloxane.

Rubber swelling agents may also be used, as described, for example, in U.S. Patent Nos. 3,974,081 and 4,029,587.

When using each of the aforementioned additives, each is used in an amount that is functionally effective to give the lubricant the desired properties. Thus, for example, if the additive is a corrosion inhibitor, a functionally effective amount of the corrosion inhibitor will be an amount sufficient to impart the desired corrosion inhibiting feature to the lubricant. Generally, in use, the concentration of each of the additives ranges from about 20% by weight or less based on the weight of the lubricant composition, in one embodiment from about 0.001 to about 20% by weight, and in one embodiment based on the weight of the lubricant composition. About 0.01 to about 10% by weight.

Example

Four fully formulated lubricant compositions were prepared and the viscosity and shear force characteristics of the compositions were compared. Each of the lubricant compositions typically contained a DI package providing 11% by weight lubricant composition. The DI package contained conventional amounts of detergents, dispersants, antiwear additives, friction modifiers, foam inhibitors, and antioxidants. The formulation also contained about 0.1 wt% pour point depressant, about 58 to 64 wt% 150 Solvent Neutral oil, about 12 to 18 wt% 600 Solvent Neutral oil. Samples 1-3 characterize commercially available olefin copolymers as viscosity modifiers. Sample 4 characterizes the shear stable olefin copolymer according to the present disclosure.

In the table, the following abbreviations are used:

VII-Viscosity Index Enhancers

KV-dynamic viscosity

CCS-Cold Cranking Simulator

MRV-Mini Rotary Viscometer-Tested to ASTM D4684

HTHS-High Temperature High Shear-Tested in accordance with ASTM D-4683, D-4781, and D-5481.

sample # One 2 3 4 Viscosity grade 15 W 50 15 W 50 15 W 50 15 W 50 ingredient weight% weight% weight% weight% HiTEC ^® 9386 ¹ 11.00 11.00 11.00 11.00 HiTEC ^® 672 ² 0.10 0.10 0.10 0.10 ESSO 150 Solvent Neutral 63.60 63.00 58.20 63.50 ESSO 600 Solvent Neutral 12.40 13.50 17.30 12.00 Viscosity Index Modifier HiTEC ^® 5748 ³ 12.90 0.00 0.00 0.00 LUBRIZOL 7077 ⁴ 0.00 12.40 0.00 0.00 PARATONE 8006 ⁵ 0.00 0.00 13.40 0.00 Shear safe ethylene / propylene copolymer (50 wt% ethylene) 0.00 0.00 0.00 13.40 Sum 100.00 100.00 100.00 100.00

sample # One 2 3 4 Grease Characteristics Polymer content (% by weight) in VII 13.12 12.61 10.27 9.88 Polymer loads in grams 1.69 1.56 1.38 1.32 KV (cSt) at 100 ℃ 18.98 19.06 19.02 18.96 KV (cSt) at 40 ℃ 144.80 146.2 144.4 146.6 Viscosity index 149 149 150 147 CCS (cP) at -20 ° C (7000 cP max) 6776 6897 6653 6840 MRV TP-1 @ -25 ℃, cP 44900 47300 0 40800 MRV yield stress <35 <35 <140 <35 Noack evaporation rate,% 11.4 10.6 10.1 10.4 HTHS (cP) at 150 ° C 4.89 4.95 4.63 4.79 KV at 100 ℃ after 30 cycles Bosch shear 16.29 16.55 16.03 16.16 KV% viscosity loss at 100 ° C (15% maximum) 14.17 13.14 15.72 14.77 Shear Safety Index (SSI,%) 23.60 20.60 24.20 24.90

¹ HiTEC ^® 9386 is a commercially available DI package available from Afton Chemical Corporation of Richmond, Virginia.

² HiTEC ^® 672 is a commercially available pour point depressant available from Afton Chemical Corporation.

³ HiTEC ^® 5748 is an olefin copolymer produced by an extrusion shear process and available from Afton Chemical Corporation.

⁴ LUBRIZOL 7077 is an olefin copolymer having an ethylene content of about 50% by weight and is available from Lubrizol Corporation of Wickliffe, Ohio. (Table results are two batch averages of LUBRIZOL 7077)

⁵ PARATONE 8006 is an olefin copolymer having an ethylene content of about 70% by weight and is available from Chevron Oronite Company LLC of Houston, Texas.

As shown in Tables 1 and 2 above, Sample 4 provides a very efficient viscosity modifier. Compared to Samples 1-3, Sample 4 had the lowest polymer load in the lubricant composition (samples 1-3 are 1.38-1.69 for 1.32). Sample 4 also showed the highest shear safety index (SSI) and passed the MRV test and CCS test, while sample 3 did not pass the MRV test and the viscosity loss test. As a result, Sample 4 showed improved viscosity and shear strength properties over commercially available ethylenic olefin copolymer products.

To prepare the shear stable olefin copolymer according to the disclosure, 10 parts by weight of ethylene / propylene copolymer having a number average molecular weight of 179,192 and a weight average molecular weight of 332,930 as measured by gas phase chromatography (GPC) was processed. Mixed with parts by weight. The oil and copolymer mixtures were circulated through a 1 to 10 GAULIN homogenizer to provide shear stable olefin copolymers with polydispersities of less than 1.5.

The properties of the olefin copolymer after passing 0-10 homogenizers are provided in the table below and FIGS. 1-3. 4-5 show a visual comparison of thickening efficiency and dynamic viscosity of olefin copolymers after 0 to 10 passes with the same properties of HiTEC ^® 5748 and LUBRIZOL 7077 (LZ 7077) (Samples 6 and 7, respectively). Compared with 1% olefin copolymer in reference oil with viscosity as shown in the table. The dynamic viscosity of the sample at 100 ° C. was estimated by thermogravimetric analysis (TGA) by dissolving 1 wt% of each sample in about 5 centistokes of reference oil (FIG. 4).

Sample No. One 2 3 4 5 6 7 Number of passes through the homogenizer 0 4 6 8 10 ---- ---- KV (cSt) at 100 ℃ 5422 1685 1299 1176 1048 1010 1212 KV (cSt) at 40 ° C 78489 21084 17234 14878 13109 13290 15153 VI 385.9 332.8 321.0 309.3 303.4 295.4 313.0 % Crystallinity 2.47 2.32 2.63 2.79 2.59 2.30 2.68 TGA / N2 (wt% polymer) 9.635 9.638 9.668 9.568 9.627 12.97 12.80 % By weight of processed oil 89.77 89.77 89.59 89.38 89.43 86.49 86.59 Mn 179192 163277 152061 153749 139436 72972 93130 Mw 332930 231655 209057 202834 183335 147926 147853 Pd 1.86 1.42 1.37 1.32 1.31 2.03 1.59

Sample No. One 2 3 4 5 6 7 Number of passes through the homogenizer 0 4 6 8 10 ---- ---- KV at 100 ° C. in reference oil (measured by TGA) 13.784 11.305 10.822 10.614 10.501 8.79 9.05 Thickening force (measured by TGA) 8.81 6.33 5.85 5.64 5.53 3.82 4.07 Thickening efficiency (measured by TGA) 2.941 2.369 2.243 2.187 2.156 1.717 1.713 KV at 100 ° C of pre-shear reference oil 11.06 10.92 10.47 10.31 10.11 ----- 10.86 KV at 100 ° C of reference oil after shearing 7.99 9.00 8.95 8.94 8.91 ------ 9.72 KV at 100 ° C of reference oil 4.89 4.95 4.95 4.95 4.95 ------ 4.95 % Viscosity loss 26.76 17.58 14.52 13.29 11.87 ------ 10.5 SSI% 49.76 32.16 27.54 25.56 23.26 24 19.29

As shown in the previous table and FIGS. 1-5, the shear stable copolymer made by passing the copolymer through the homogenizer 10 times or more meets the shear stability index (SSI) requirement of about 23 (Sample 5). It can be tailored to provide a viscosity modifier with significantly higher thickening efficiency (sample 5) compared to conventional olefin copolymer viscosity modifiers (samples 6 and 7). The mechanical shearing of the olefin copolymer adds the advantage of providing a shear stable olefin copolymer with polydispersity of less than 1.5 (Sample 5, Table 3).

In many places throughout this specification, reference has been made to a number of U.S. patents. All documents cited are expressly incorporated into this disclosure as if fully set forth herein.

The aforementioned embodiments are subject to considerable change in its practice. Accordingly, this embodiment is not intended to be limited to the specific illustration set forth herein. Rather, the foregoing embodiments include those which are legally available and equivalent and are within the spirit and scope of the appended claims.

The patent owner is not intended to provide any disclosed embodiment to the public, and any disclosed modifications or variations are not intended to be literally within the scope of the claims, which are to be considered part of this application on an equivalent basis.

Provided are improved viscosity modifiers that are shear stable and more cost effective when used in lubricant compositions.

Claims (48)

Thin film coatings of lubricant compositions containing from about 5 to about 30 percent by weight of 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 ranging from about 50,000 to about 250,000. A lubricating surface comprising, the shear stability index of the shear stable olefin copolymer is less than about 40, the polydispersity is less than about 1.5, the thickening efficiency is greater than about 1.8, and the amount of additives in the lubricant composition is the total amount of the lubricant composition. A lubricating surface based on weight and having a shear temperature of 35 to 100 ° C. of the copolymer. The lubricating surface of claim 1, comprising an engine drive. The lubricating surface of claim 1, comprising an internal surface or a component of an internal combustion engine. The lubricating surface of claim 1, wherein the lubricating surface comprises an interior surface or components of a compression ignition engine. The lubricating surface of claim 1, wherein the shear stable copolymer is derived from the group consisting of ethylene-propylene monomers, ethylene-propylene-diene monomers, styrene-isoprene and styrene-neoprene monomers. delete The lubricating surface of claim 1, wherein the monomer number of each monomer unit of the shear stable copolymer is from about 2 to about 10 carbon atoms. The lubricating surface of claim 1, wherein the shear stable copolymer has an ethylene content of less than about 70% by weight of the copolymer. An automobile vehicle comprising the lubricating surface of claim 1. A vehicle having a movable part and comprising a lubricant for moving part lubrication, the lubricant comprising an oil of lubricating viscosity and a shear stable olefin copolymer derived from a copolymer having a number average molecular weight in the range of about 50,000 to about 250,000. To about 30% by weight of an additive, wherein the shear stable olefin copolymer has a shear safety index of less than about 40, polydispersity of about 1.5 or less, thickening efficiency of greater than about 1.8, and the amount of additive in the lubricant A vehicle based on the total weight of lubricant, wherein the shear temperature of the copolymer is from 35 to 100 ° C. The vehicle of claim 10 wherein the shear stable copolymer is derived from the group consisting of ethylene-propylene monomers, ethylene-propylene-diene monomers, styrene-isoprene and styrene-neoprene monomers. The vehicle of claim 10 wherein the shear stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer. 11. The vehicle of claim 10, wherein the movable portion comprises a heavy duty diesel engine comprising an exhaust gas recirculation and lubrication system for the engine. 11. The vehicle of claim 10, wherein each monomer unit of the shear stable copolymer has from about 2 to about 10 carbon atoms. The vehicle of claim 10, wherein the shear stable copolymer comprises an amorphous ethylene containing copolymer having an ethylene content of less than about 70% by weight of the copolymer. A fully formulated lubricant composition containing from about 5 to 30% by weight of an additive comprising a base oil component of lubricating viscosity and a shear stable copolymer derived from a copolymer having a number average molecular weight in the range of about 50,000 to about 250,000. The shear stability index of the shear stable olefin copolymer is less than about 40, the polydispersity is less than about 1.5, the thickening efficiency is greater than about 1.8, the amount of additives in the lubricant is based on the total amount of the lubricant composition, The lubricant composition has a shear temperature of 35 to 100 ° C. 17. The lubricant composition of claim 16 wherein the shear stable copolymer is derived from the group consisting of ethylene-propylene monomers, ethylene-propylene-diene monomers, styrene-isoprene and styrene-neoprene monomers. 18. The lubricant composition of claim 16 wherein the shear stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer. The lubricant composition of claim 16 wherein each monomer unit of the shear stable copolymer has from about 2 to about 10 carbon atoms. The lubricant composition of claim 16, wherein the shear stable copolymer has an ethylene content of less than about 70% by weight. Viscosity of lubricant composition comprising mixing with lubricant composition containing about 5 to about 30% by weight of an additive comprising a shear stable olefin copolymer derived from a copolymer having a number average molecular weight ranging from about 50,000 to about 250,000 As a method of improving the index, the shear stable olefin copolymer has a shear safety index of less than about 40, a polydispersity of about 1.5 or less, a thickening efficiency of more than about 1.8, and a shear stable olefin air in the lubricant composition. The amount of coalescing is based on the total weight of the lubricant composition and the shear temperature of the copolymer is from 35 to 100 ° C. The method of claim 21, wherein the lubricant composition comprises a multi-viscosity lubricant. 22. The method of claim 21, wherein the shear stable copolymer is derived from the group consisting of ethylene-propylene monomers, ethylene-propylene-diene monomers, styrene-isoprene and styrene-neoprene monomers. 22. The method of claim 21, wherein the shear stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer. 22. The method of claim 21, wherein each monomer unit of the shear stable copolymer has from about 2 to about 10 carbon atoms. The method of claim 21, wherein the shear stable copolymer comprises an amorphous ethylene containing copolymer having an ethylene content of less than about 70% by weight of the copolymer. A lubricant additive concentrate containing from about 5 to about 90 weight percent of an additive comprising a diluent or carrier oil and a shear stable olefin copolymer derived from a copolymer having a number average molecular weight ranging from about 50,000 to about 250,000, The shear stability index of the shear stable olefin copolymer is less than about 40, the polydispersity is less than about 1.5, the thickening efficiency is greater than about 1.8, and the amount of shear stable olefin copolymer in the lubricant composition is the total weight of the additive concentrate. Additive concentrate having a shear temperature of from 35 to 100 ° C. The additive concentrate of claim 27 wherein the shear stable copolymer is derived from the group consisting of ethylene-propylene monomers, ethylene-propylene-diene monomers, styrene-isoprene and styrene-neoprene monomers. 28. The additive concentrate of claim 27 wherein the shear stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer. 28. The additive concentrate of claim 27 wherein each monomer unit of the shear stable copolymer has from about 2 to about 10 carbon atoms. The additive concentrate of claim 27, wherein the shear stable copolymer has an ethylene content of less than about 70% by weight of the copolymer. A lubricant composition comprising a base oil and the additive concentrate of claim 27. A vehicle moving part lubrication method, the method comprising using a lubricant composition containing a base oil and a lubricant additive as lubricant for one or more moving parts of a vehicle, the additive being shear stable in the diluent or carrier oil, and the lubricant composition. A shear stable olefin copolymer derived from a copolymer having a number average molecular weight in the range of about 50,000 to about 250,000 in an amount sufficient to provide about 5 to about 30 weight percent of the olefin copolymer; The shear stability index of the olefin copolymer is less than about 40, the polydispersity is less than about 1.5, the thickening efficiency is greater than about 1.8, and the amount of shear stable olefin copolymer in the lubricant composition is based on the total weight of the lubricant composition. The shear temperature of the copolymer is 35 to 100 ℃. 34. The method of claim 33, wherein the shear stable copolymer is derived from the group consisting of ethylene-propylene monomers, ethylene-propylene-diene monomers, styrene-isoprene and styrene-neoprene monomers. 34. The method of claim 33, wherein the shear stable copolymer comprises an olefin copolymer mechanically sheared in a homogenizer. 34. The method of claim 33, wherein each monomer unit of the shear stable copolymer has from about 2 to about 10 carbon atoms. 34. The method of claim 33, wherein the shear stable copolymer comprises an amorphous ethylene containing copolymer having an ethylene content of less than about 70% by weight of the copolymer. 34. The method of claim 33 wherein the vehicle comprises a diesel engine and the movable portion comprises a movable portion of the engine. 34. The method of claim 33 wherein the vehicle comprises a vessel having an engine and the movable portion comprises a movable portion of the engine. 34. The method of claim 33 wherein the vehicle comprises a spark ignition engine and the movable portion comprises a movable portion of an engine. 34. The method of claim 33 wherein the vehicle comprises a drive and the movable portion comprises a movable portion of the drive. 34. The method of claim 33, wherein the vehicle comprises an internal combustion engine having a crankcase and the lubricant composition contains crankcase oil present in the crankcase of the vehicle. 34. The method of claim 33, wherein the lubricant composition comprises a drive lubricant present in an automobile drive of a vehicle. A moving part lubrication method comprising contacting a movable part with a lubricant composition containing a lubricant additive, wherein the lubricant additive is shear stable derived from a diluent or carrier oil and a copolymer having a number average molecular weight in the range of about 50,000 to about 250,000. Comprising about 5 to about 95 weight percent of an olefin copolymer, wherein the shear stable olefin copolymer has a shear safety index of less than about 40, a polydispersity of about 1.5 or less, a thickening efficiency of more than about 1.8, and a lubricant The composition contains from about 5 to about 30 weight percent of the additive based on the total weight of the lubricant composition and the shear temperature of the copolymer is from 35 to 100 ° C. 45. The method of claim 44, wherein the movable portion comprises a movable portion of the vehicle. 45. The method of claim 44 wherein the vehicle is a vessel with an engine and the movable portion comprises a movable portion of the engine. 45. The method of claim 44, wherein the movable portion comprises an internal combustion engine having a crankcase, and wherein the lubricant composition comprises crankcase oil present in the crankcase of the vehicle. 45. The method of claim 44, wherein the lubricant composition comprises a drive lubricant present in an automotive drive of a vehicle.

Images