MXPA02004109A

MXPA02004109A - Interpolymers containing lubricating oil composition.

Info

Publication number: MXPA02004109A
Application number: MXPA02004109A
Authority: MX
Inventors: Michael J Covitch; Daniel E Bowen
Original assignee: Lubrizol Corp
Priority date: 1999-10-25
Filing date: 2000-10-24
Publication date: 2002-10-17
Also published as: WO2001030947A1; CA2388946A1; EP1238046A1; BR0015213A; AU1344001A; KR20020051924A; JP2003513149A

Abstract

Lubricating oil compositions comprising substantially random interpolymers comprising (1) ethylene, (2) one or more vinylic monomers selected from the group consisting of aromatic, hindered aliphatic, and cycloaliphatic vinylic monomers, and (3) one or more olefinic monomers having from 3 to about 20 carbon atoms useful as viscosity index improving agents.

Description

COMPOSITION OF LUBRICANT OIL WITH CONTENT IN INTERPOLYMERS FIELD OF THE INVENTION The present invention is framed within the field of lubricating oil compositions which include (1) ethylene-containing methyl ether polymers; (2) one or more vinyl monomers selected from the group consisting of vinyl cycloaliphatic, hindered aliphatic and aromatic monomers, and (3) one or more polymerizable C3 to C2 olefinic monomers. These polymers serve as agents to improve viscosity.

BACKGROUND OF THE INVENTION The viscosity of lubricating oils, in particular, the viscosity of lubricating oils based on mineral oil, generally depends on the temperature. As the oil temperature increases, the viscosity usually decreases. The function of an agent for improving the viscosity in lubricating oil compositions is to reduce the degree of viscosity decrease when the temperature is raised or to reduce the degree of increase in viscosity when the temperature is reduced, or both. Therefore, an agent to improve the viscosity improves the viscosity change of an oil containing it with changes in temperature. The fluid characteristics of the oil are improved. Agents for improving viscosity are usually polymeric materials and are often referred to as :?! l LI * *! ,? Á * W v tJ ^ - * ***** - **, * • agents to improve the viscosity index. Ranney (Ed.), "Lubricant Additives," Noyes Data Corp. (1973), pp. 93-145, has set forth numerous patents that refer to agents for improving viscosity. A series of hydrogenated alkenylarene conjugated diene interpolymers of the prior art are known as effective in improving the viscosity index (IV) of lubricating oils. US patents No. 3,554,911 (Schiff et al.); 3,630,905 (Sorghum); and 3,772,169 (Small and < fl. 10 cois.) refer to the use of randomized hydrogenated butadiene-styrene copolymers as agents for improving the viscosity index of lubricating oils. These copolymers are prepared by copolymerization, using conventional techniques, of butadiene and styrene in the presence of a 15 randomization agent and, subsequently, the copolymers are partially hydrogenated. • The US patent No. 2,336,195 (Sparks et al.) Refers to the improvement of the viscosity characteristics of hydrocarbon oils by the addition of normal mono-olefin polymers. The US patent No. 3,772,196 (St. Clair et al.) Describes lubricating oils for internal combustion engines that exhibit operating characteristics over a wide range of temperatures. The composition contains a combination of a 2-block copolymer including a first block of an alkenyl arene, eg, styrene, and a second block of substantially completely hydrogenated polyisoprene and certain agents for lowering the pour point in an oil of lubricant base having a viscosity index of at least 85.

Many vinyl aromatic-diene monomer copolymers of prior art are graded block copolymers. The interpolymers of the present invention are random interpolymers. The generic class of materials covered by substantially random interpolymers of alpha-olefin / hindered vinyl monomer and including materials such as ethylene / vinyl aromatic monomer interpolymers is known within the art. For example, the interpolymers of Ethylene / styrene substantially random, among which include the pseudo-random interpolymers described in EP 415815 A, offer a range of material structures and properties that make them useful for various applications, including the compatibilization of mixtures of 15 polyethylene and polystyrene, as described in US Pat. 5,460,818. In the US patent No. 5,244,996 describes random copolymers of vinyl aromatic monomer and an alpha olefin having from 4 to 12 carbon atoms. In the US patent 5,872,201 interpolymers of the The type which is currently considered useful in the lubricating oil compositions of the present invention. Other patent publications provide a generic reference limited to tere-polymers of ethylene / styrene / alpha-olefin materials. Examples of JP 07 / 278,230 f 25 are limited to the incorporation of 2 mole percent or less of styrene into ethylene / alpha-olefin copolymers. None of these references disclose the use of these polymers as additives to improve the viscosity of lubricating oil compositions.

In spite of the usefulness that they already suppose on their own, efforts continue to be made to further expand the usefulness of these generic interpolymers in lubricant applications, especially those based on alpha-olefin / 5 vinyl aromatic monomers, such as for example, ethylene / styrene interpolymers. Lubricating applications include the use of polymers as agents to improve viscosity for lubricating oils and as thickeners for lubricating greases. The improvement characteristics or superiors I? Desirable for the materials of the state of the art can include, without being limited only to them, the characteristics of behavior as they are the greater interval of temperature of application and the yield to low temperature and a better compatibility with a series of 15 lubricating viscosity oils, especially synthetic oils and base oils with high viscosity index. The F interpolymers used in the lubricating oil compositions of the present invention are less expensive compared to aromatic monomer copolymers 20 vinyl-hydrogenated diene. The interpolymers of the present invention provide an effective technology to address these needs.

The present invention relates to lubricating oil compositions that include a major amount of an oil of lubricating viscosity and a minor amount, to improve the viscosity, of a substantially random interpolymer that is the result of polymerization. (1) from about 19.5 to about 98.5 percent in ethylene heads; (2) from about 0.5 to 50% by weight of one or more vinyl monomers selected from the group consisting of aromatic, hindered aliphatic and vinyl cycloaliphatic monomers; and (3) from about 1 to about 80 mole percent of one or more olefinic monomers having from 3 to about 20 carbon atoms. One aspect of the present invention falls within the field of lubricating oil compositions including interpolymers containing (1) from about 19.5 to about 98.5 mole percent ethylene, (2) about 0 , 5 to about 60 mole percent of a vinyl monomer selected from the group consisting of vinyl cycloaliphatic, hindered and aromatic aliphatic monomers and (3) from about 1 to about 80 mole percent of one or more olefinic monomers of C3 to C20. In one of the embodiments, the interpolymers of the present invention can include any of the three monomers that have been mentioned; said interpolymers may include three of the polymerizable monomers listed, the third monomer (3) being an olefinic C3 to C20 monomer. The interpolymers of the present invention may be free of any component, compound or substituent not specifically listed herein. Also, the present invention may be free of any component, compound or substituent, although said compound or substituent component was originally considered as part of the invention. ^ * 5 ^ t * The interpolymers of the present invention provide an improvement of one or more of the properties, such as the viscosity index of lubricating oils and better compatibility with a wide variety of lubricating viscosity oils, especially oils with a high viscosity index and, in particular, synthetic oils.

DETAILED DESCRIPTION OF THE INVENTION The term "tere-polymer" as used herein, denotes a polymer in which three different monomers are polymerized to form the tere-polymer. The term "interpolymer" as used herein denotes a polymer in which three or more different monomers are polymerized to form the interpolymer. The term "substantially randomized" in a substantially random interpolymer including ethylene, one or more vinyl aromatic monomers or hindered aliphatic vinyl monomers, and one or more olefinic monomers of C3 to C0 as used herein, means that the distribution of the monomers of said interpolymer can be described according to the Bernoulli statistical model or by a Markovian statistical model of the first or second order, as described by JC Randall in POLYMER SEQUENCE DETERMINATION, Carbon-13 NMR Method, Academic Press, New York (1977), pp . 71-78. Preferably, the substantially random interpolymer contains no more than 15 percent of the total amount of vinyl aromatic monomer in vinylaromatic monomer blocks of more than 3 units. More preferably, the interpolymer is not characterized by a high degree of isotacticity or syndiotacticity. This means that in the yíifaÉ ^ .... ^ *. «.. * r ..i ^ ^ U ^^. * ¡^ iJ ^ ASM -a Carbon-NMR spectrum -13 of the substantially interstitial interpolymer, the peak zones corresponding to the methine and methylene carbons of the main chain representing the average bivalent radical sequences or the racemic bivalent radical sequences shall not exceed 75 percent of the total peak area of the methine and methylene carbons of the main chain. The numerical values indicated here include all values from the lowest value to the highest value in increments of one unit, as long as there is a separation of at least 2 units between the lower values and the higher values. For example, if it is pointed out that the amount of a component or a value of a process variable such as, for example, temperature, pressure, time and the like, is for example from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32, etc. are expressly listed in the present specification. For values that are less than one, a unit is considered to be 0.0001, 0.001, 0.01 or 0.1, as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value indicated should be considered as expressly stated in the present application in a similar manner. The interpolymers used in the lubricating oil compositions of the present invention include at least three different monomers, (1) from about 19.5 to about 98.5, preferably from about 25 to about 95, more preferably about 30. to. about 94 mole percent ethylene; (2) give from about 0.5 to about 60, preferably from about 1 to about 55, more preferably from about 1 to about 50 mole percent of one or more vinyl aromatic monomers or hindered aliphatic vinyl monomers, and (3) from about 1 to about 80, preferably from about 4 to about 65, more preferably from about 5 to about 5 mole percent of one or more olefinic C3 to C20 monomers. It should be understood that the total amount of (1), (2) and (3) is 100 mole percent. The weight average molecular weight (Mw) of the interpolymers of the present invention is usually greater than about 10,000, preferably from about 50,000 to about 700,000, more preferably from about 80,000 to about 350,000. The molecular weights of the hydrocarbon polymer are determined by applying the known methods described in the literature. Examples of methods for determining molecular weights include gel permeation chromatography (GPC) (also known as size exclusion chromatography) and vapor phase osmometry (VPO). These procedures along with others are described in numerous publications, among which are included: P.J. Flory, "Principles of Polymer Chemistry," Cornell University Press (1953), chapter VII, pp. 266-316, "Macromolecules, an Introduction to Polymer Science," F.A. Bovey and F.H. Winslow, Editors, Academic Press (1979), pp. 296-312, and »« «ME« - £ * > W. Yau, J.J. Kirkland and D.D. Bly, "Modern Size Exclusion Liquid Chromatography", John Wiley and Sons, New York, 1979. The molecular weight values referred to herein are direct molecular weights determined by the use of GPC with light scattering at various angles and refractive index for detection . Such methods are described in the literature, for example, in Barth et al., Chemical Analysis, vol. 113, "Modern Methods of Polymer Characterization", John Wiley & Sons, (1991). Other procedures that can be used include CPG with the use of polystyrene standards. It is particularly preferable that the interpolymer of the present invention is a terpolymer. Especially preferred is the polymer in which the component (2) is an aromatic vinyl monomer, more preferably styrene, and the component (3) is an alpha olefin having from 3 to about 12 carbon atoms, more preferably one or more olefinic monomers selected from the group consisting of propylene, butene-1,4-methyl-1-pentene, pentene-1, hexene-1 and octene-1. The present invention relates in particular to the following tere-polymers : ethylene / styrene / propylene; ethylene / styrene / 4-methyl-1-pentene; ethylene / styrene / hexene- 1-; ethylene / styrene / octene-1; and ethylene / styrene / 1-butene. Suitable alpha-olefins, or combinations of alpha-olefins, which can be used as olefinic monomers (3) include, for example, those containing from 3 to about 20, preferably from 3 to about 12, more preferably from 3 to about 8 carbon atoms. Suitable monomers which can be used as olefinic monomers (3) include ring-ring olefins deformed as norbornene. Particularly suitable are olefinic monomers (3) propylene, 4-methyl-1-pentene-, pentene-1, hexene-1, octene-1 and butene-1. The olefinic reagent (3) does not include cycloaliphatic and hindered aliphatic olefins as defined herein for reagent (2). 10 Among the vinyl aromatic monomers suitable for • its use as component (2) include, for example, those represented by the following formula: Ar 15 (CH2) n R1 - C = CH2 Wherein R1 is selected from the group of radicals consisting of hydrogen and hydrocarbyl groups, preferably alkyl or aryl groups, especially alkyl radicals containing from 1 to about 4 carbon atoms and, more preferably, hydrogen or methyl; and Ar is a phenyl group or a phenyl group substituted with 1 to 3 substituents selected from the group consisting of halo, C 1-4 alkyl, and C 1-4 haloalkyl; and n has a value comprised between zero and approximately 6, preferably between zero and approximately 2, more preferably zero. Between the 30 examples of monovinyl aromatic monomers are included t > ar. vinyl toluene, alpha-ethyl styrene, 4"-fc * bthyl chlorostyrene, including all the isomers, and the like Particularly useful monomers include styrene and substituted lower alkyl or halogen derivatives thereof. include styrene, alpha-methyl styrene, derivatives substituted with lower alkyl or styrene phenyl ring, such as ortho-, meta- and para-methylstyrene, halogenated ring styrenes, para-vinyl toluene or mixtures thereof and the like. Preferred monovinyl aromatic monomers are styrene .. Suitable "vinyl cycloaliphatic or hindered aliphatic monomers" suitable for use as components (2) include polymerizable vinyl monomers of addition 15 that correspond to the following formula: R¿ R1-C = CH2 wherein R1 is selected from the group of radicals consisting of hydrogen and hydrocarbyl groups, preferably alkyl or aryl groups, especially alkyl radicals containing from 1 to about 4 carbon atoms, more Preferably hydrogen or methyl; and R2 is a sterically volume aliphatic substituent of up to 20 carbon atoms; or alternatively R1 and R2 together form a ring system. The term "volume sterically" means that the monomer bearing this substituent is normally 30 incapable of an addition polymerization through a Ziegler-Natta polymerization catalyst normal at a vPilinity comparable to ethylene polymerizations. Preferred cycloaliphatic or hindered aliphatic vinyl monomers include those in which one of the carbon atoms carrying ethylenic unsaturation has tertiary or quaternary substitution. Examples of such substituents include cyclic aliphatic groups such as cyclohexyl, cyclohexenyl, cyclooctenyl or derivatives substituted with aryl or alkyl in the ring thereof, 10 tert-butyl, norbornyl and the like. Most preferred cycloaliphatic or aliphatic hindered vinyl compounds are vinyl cyclohexane and the various isomeric vinyl ring substituted derivatives of cyclohexene and substituted cyclohexanes and 5-ethylidene-2-norbornene. Is 15 especially suitable vinyl cyclohexane. The substantially random interpolymers of the The present invention can be prepared as described in EP-A-0,416,815 (Stevens et al.) Which is incorporated herein by reference in its entirety. The operating conditions Preferable for these polymerization reactions are pressures comprised between atmospheric pressure and up to 3000 atmospheres and temperatures of -30 ° C to 200 ° C. Polymerizations and removal of the unreacted monomer at temperatures above the temperature of 25 autopolymerization of the corresponding monomers may • result in the formation of certain amounts of homopolymer polymerization products as a result of the polymerization of free radicals. At the same time as the substantially random interpolymers of the With the present invention as described below, an amount of aromatics homopolymer can be formed. { iyi | ílíco: ico as a consequence of the homopolymerization of the aromatic vinyl monomer. However, NMR indicates that polystyrene may be present in the styrene monomer 5 and that it is not always generated during the polymerization reaction. Therefore, the presence of the polystyrene in the polymer can be avoided by the use of styrene monomer of suitable purity. The presence of the aromatic vinyl homopolymer General is not desirable for the purposes of this • invention, as it often results in turbid oil mixtures. The vinyl aromatic homopolymer can be separated from the interpolymer, if desired, by extraction techniques such as selective precipitation from the solution 15 with a substance that is not solvent for the interpolymer or aromatic vinyl homopolymer. For example, it • dissolves a polymer containing polystyrene in hexane and coagulates in acetone. For the purposes of the present invention, it is preferable that the copolymers of the invention are 20 substantially free of aromatic vinyl homopolymer. As used herein "substantially free" means that the copolymer does not contain any amount of aromatic vinyl homopolymer that can cause a negative turbidity or any incompatibility in the 25 lubricating oil composition. Preferably, the • copolymer is free of aromatic vinyl homopolymer. Examples of suitable catalysts and methods for preparing the substantially random interpolymers of the present invention include those described in EP-A-30 416 815; EP-A-514,828; US patent No. 5,721,185; US patent UU Nc 5 470. 993; as well as the US patents UU N ° 5,055,438; 5,057,475; 5,096,867; 5,064,802; 5,132,380; 5,189,192; 5,321,106; 5,347,024; 5,350,723; 5,374,696; 5,399,635; 5,556,928; 5,703,187 and 5,872,201, patents and 5 applications that are incorporated herein by reference. The substantially random interpolymers of the present invention can also be prepared by the methods described by Bradfute et al., In WO 95/32095; by 10 Pannell in WO 94/00500; and in Plastics Technology, p 25 (September 1992), which are incorporated herein by reference in their entirety. Other preparation methods that can be applied for the interpolymers of the present invention have been described in the literature. Longo and Grassi 15 (Makromol, Chem., Volume 191, pages 2387 to 2396

[1990] and D'Anniello et al. (Journal of Applied Polymer Science, • volume 58, page 1701-1706

[1995]) describes the use of a catalytic system based on methylaluminoxane (MAO) and cyclopentadienyltitanium trichloride (CpTiCl3) to prepare 20 an ethylene-styrene copolymer. Xu and Lin (Polymer Preprints, Am. Chem. Soc., Div., Polym. Chem.) Volume 35, page 686-687

[1994] have described copolymerization using a TiCl 4 / NdCl 3 / Al (iBu) 3 catalyst to give random copolymers of styrene and propylene. Lu y cois. 25 (Journal of Applied Polymer Science, volume 53, pages 1453 • at 1460

[1994] have described the copolymerization of ethylene and styrene using a TiCl / NdCl3 / MgCl2 / Al (Et) 3 catalyst. Sernetz et al. (Macromol. Chem. Phys., V 197, pp. 1071-1083, 1996) have described the copolymerization of styrene with Ethylene using? 6- (C5 (CH3) 4Si (CH3) 2N (ere-C4H9)) TiCl2 / methylaluminoxane. Another suitable method includes the method described for the manufacture of alpha olefin / vinyl aromatic monomeric polymers such as, for example, propylene / styrene and butene / styrene, described in US Pat. No. 5,244,996, assigned to Mitsui Petrochemical Industries Ltd. All the aforementioned documents are incorporated herein by reference. Additives such as for example organic antioxidants (e.g. hindered phenols as by • 10 example, IRGANOX® 1010), phosphites (eg, IRGAFOS® 168), both of Ciba-Geigy, UV stabilizers and the like, in the interpolymers, additive concentrates and lubricating oil compositions of the present invention, as long as do not interfere with the improved properties discovered by 15 the authors of the request. The following examples serve to illustrate the • polymers used in the lubricating oil compositions of the invention, but should not be considered as limiting the scope of the invention in any way. All 20 temperatures are in degrees Celsius (° C).

Polymerization: In a typical polymerization system, dry hexane is pressurized (see table 1) from a holding tank of 25 stainless steel, under nitrogen in a dry 3.7 liter (1 gallon) batch reactor equipped with a magnetically driven stirring mechanism. A heptane solution of methylaluminoxane (120 g, 165.5 mL, 7% by weight Al), which contains 30% by weight of isobutyl groups, is pressurized in the heptane. 30 reactor under nitrogen. Freshly distilled styrene and alpha-olefin are added (see tables 1-2) and the homogeneous mixture is thermostabilized at the desired temperature (see table 1). Once the desired temperature is reached, the reactor is pressurized with the desired amount of ethylene (see tables 1-2). Finally, a heptane solution of methylaluminoxane (34.8 g, 47.7 mL, 7% by weight of Al) containing 30% by weight of isobutyl groups is mixed with? 6- (C5 (CH3) 4 Si (CH3) 2N (tert-C4H9) TiCl2 (9.6 mg) to form a homogeneous solution.This solution is added to the reactor under nitrogen within 5 minutes of becoming homogeneous.The polymerization reaction is terminated at the end of the reaction. a period of time (see table 1) letting ventilate the ethylene of the reactor and pressurizing the polymer cement of the reactor under nitrogen in iso-propyl alcohol (2 L), to which has been added HCl (15, 25 ML, 18M).

Polymer purification: The coagulated polymer is collected and rinsed with fresh iso-propyl alcohol (1 L). The process is repeated 2 to 3 times. The coagulated polymer is air dried for 24 to 48 h and then dried at a constant weight at 50 ° C in a vacuum oven. All the inorganic material of residual aluminum is separated by exclusive centrifugation of a solution of tetrahydrofuran (0.1 to 0.15 g / mL) of the polymer, in which it is insoluble in inorganic aluminum material. The polymer is decanted from the insoluble material, coagulated in fresh iso-propyl alcohol, dried in the air for 24 to 48 hours and then dried at a constant weight, at 50 ° C in a vacuum oven. The process is repeated 2 to 3 times. The homopolystyrene that may be present in the polymer is separated by coagulation of a solution in tetrahydrofuran (0.1-0.15 g / m *) -of the polymer in acetone (approximately 1.5 to 2 L). The coagulated polymer is then collected by decantation, air dried for 24 to 48 hours, and then dried at a constant weight at 50 ° C in a vacuum oven. You can repeat this process also when necessary. If the polymer contains polystyrene homopolymer, it can be dissolved, if desired, the polymer in hexane and coagulated in acetone, effectively removing the polystyrene. The interpolymer is free of impurities if a homogeneous solution is formed when a 10% by weight solution of the polymer is formed with mineral oil.

Table 1 (g) - grams (h) - hours (L) - milliliters (psig) - pound per square inch, gauge = 6,895 kPa (hex) - hexene (oct) - octene • Results: Tables 3-4 show the results • Table 3 * (kg / moles Ti / h) Table 4 shows the compositions of the copolymers of examples 1-9 (% moles, measured by 1H NMR) and molecular weights (GPC, (light scattering at various angles and refractive index for detection).

Table 4 differential refractive index Other additives The additive concentrates and lubricating oil compositions of the present invention may contain other additives. The use of such additives is optional and their presence in the compositions of the present invention will depend on the particular use and the level of performance required. Therefore, other additives can be included or excluded. The additive concentrates of the present invention typically constitute from about 0.1% to about 30% by weight of the interpolymer and from about 70% to about 99.9% by weight of a substantially liquid, substantially inert organic diluent. Lubricating oil compositions often include zinc salts of a dithiophosphoric acid, generally called zinc dithiophosphates, zinc O-dihydrocarbyl dithiophosphates and other commonly used names. Sometimes they are called with the abbreviation ZDP. One or more zinc salts of dithiophosphoric acids may be present in a minor amount to provide additional extreme pressure, anti-wear and antioxidant behavior. Optionally, other additives may be used in the lubricating oils of the present invention, among which are included for example detergents, dispersants, supplementary viscosity-improving agents, agents for inhibiting oxidation, agents for inhibiting corrosion, agents for reducing the pour point, extreme pressure agents, anti-wear agents, color stabilizers, friction modifiers and antifoaming agents. Examples of extreme pressure agents and corrosion and oxidation inhibiting agents that can be included in the compositions of the present invention include chlorinated aliphatic hydrocarbons, organic sulfides and polysulfides, phosphorous esters including dihydrocarbon and trihydrocarbon phosphites, compounds of molybdenum and the like. Other examples of oxidation inhibiting agents include materials such as, for example, alkylated diphenyl amines, hindered phenols, especially those having i? i i ii? líí? ' iii itiiii rr m iTiimii t? i ?? i l? lr? rn? l [? r ??? ii? i? Iii tertiary alkyl groups such as, for example, tertiary butyl groups in the ortho position of the phenolic -OH group, and others. Said materials are known among the specialists in this field. Auxiliary viscosity improving agents (also referred to as viscosity indexing agents or viscosity modifiers) may also be included in the compositions of the present invention. Agents for improving viscosity are usually polymers, including polyisobutenes, polymethacrylic acid esters, hydrogenated diene polymers, polyalkyl esters, esterified styrene-maleic anhydride copolymers, hydrogenated conjugated alkenylarene-conjugated diene copolymers and polyolefins. Multifunctional viscosity improving agents, which also have dispersing and / or antioxidant properties are known and may optionally be used in addition to the products of the present invention. These products are described in numerous publications, including those mentioned in the Background of the Invention section. Each of said publications is expressly incorporated herein by reference. Agents to reduce the pour point can be included in the additive concentrates and lubricating oils described herein. Those that can be used are described in the bibliography and are well known among specialists in this field; see for example page 8 of "Lubricant Additives" by C.V. Smalheer and R. Kennedy Smith (Lezius-Hiles Company Publisher, Cleveland, Ohio, 1967). The agents for reducing the pour point useful for For the purposes of the present invention, the techniques for their preparation and their use are described in US Pat. No. 2,387,501; 2,015,748; 2,655,479; 1,815,022; 2,191,498; 2,666,748; 2,721,877; 2,721,878; 3,250,715; and 5,707,943 5 are expressly incorporated herein by reference as to their corresponding descriptions. Anti-foaming agents used to reduce or prevent the formation of stable foam include silicones and organic polymers. In "Foam Control Agents" of 10 Examples of these and other additional defoaming compositions are described by Henry T. Kerner (Noyes Data Corporation, 1976), pages 125-162. Detergents and dispersants can be of the type that produce ash or of the type that has no ash. Between the Examples of ash-producing detergents include neutral and basic oil-soluble salts of alkali and alkaline-earth metals with sulfonic acids, carboxylic acids, phenols or organic phosphorous acids characterized by having at least one direct carbon-to-phosphorus bond. The term "basic salt" is used to designate the metal salts in which the metal is present in stoichiometrically greater amounts than the organic acid radical. The relative amount of metal present in the "basic salts" is often indicated by the expression 25"metal ratio" (abbreviated RM), which is defined as the number of metal equivalents present compared to the "normal" stoichiometric amount. Therefore, for example, a basic salt containing twice the amount of metal compared to the stoichiometric amount, 30 has a metal ratio (RM) of 2. Basic salts and The techniques for their preparation and use are well known among those skilled in the art and, therefore, it is not necessary to describe them here in detail. Ashless detergents and dispersants are so named despite the fact that, depending on their constitution, the detergent or dispersant can produce, after combustion, a non-volatile residue such as, for example, boric oxide or phosphorus pentoxide; however, it usually does not contain metal and therefore does not produce an ash with metallic content in the combustion. Many types are known within the art, any of them being suitable for use in the lubricants of the present invention. The following are set forth by way of illustration: (1) Reaction products of carboxylic acids (or derivatives thereof) containing at least about 34, preferably at least about 54 carbon atoms with nitrogen containing compounds such as amine, organic hydroxy compounds such as phenols and alcohols, and / or basic inorganic materials. British Patent Nos. 1,306,529 and numerous US patents, including those listed below, are examples of these "carboxylic dispersants": 3. 16,603 3,399,141 3,574,101 3.18,474 3,415,750 3,576,743 3,215,707 3,433,7,630,904 3,219,666 3.44,170 3,632,510 3,271,310 3,448,048 3,632,511 3,272,746 3,448. 049 3,697,428 3,281,357 3,451,933 3,725.4 1 3,306,908 3,454,607 4,194,886 3,311,558 3,467,668 4,234,435 3,316,177 3,501,405 4,491,527 3,340,281 3,522,179 5,696,060 3,341,542 3,541,012 5,696,067 3,346,493 3,541,678 5,779,742 3,351,552 3,542,680 RE 26,433 3,381,022 3,567,637 (2) Relatively high molecular weight reaction products of aliphatic or alicyclic halides with amines, preferably polyalkylene polyamines. They can be characterized as "amine dispersants", and examples of them can be found in the following patents, for example: 3. 275,554 3,454,555 3,438,757 3,565,804 (3) Reaction products of alkyl phenols in which the alkyl groups contain at least about 30 carbon atoms, with aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines), which can be characterized as "Mannich dispersants" . Illustratively, the materials described in the following US patents can be mentioned: i l.l iilmÜÉi ilillMittiaiÉilfltll 3,697,574 3,726,882 3,725,277 (4) Products obtained by post-treatment of carboxyl amine or Mannich dispersants with reagents such as urea, thiourea, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, nitriles, epoxides, boron compounds, 10 phosphorus compounds or similar. In the US patents which are indicated below are examples of materials of this type. 3. 036,003 3,282,955 3,493,520 3,639,242 3,087,936 3,312,619 3,502,677 3,649,229 3,200,107 3,366,569 3,513,093 3,694 659 3,216,936 3,367,943 3,533,945 3,658,836 3,254,025 3,373,111 3,539. 633 3,697,574 # 3,256,185 3,403,102 3,573,010 3,702, 757 3,278,550 3,442,808 3,579,450 3,703,536 3,280,234 3,455,831 3,591,598 3,704,308 3,281,428 3,455,832 3,600,372 3,708,522 4,234,435 15 (5) Polymers and copolymers of oleosolubilizing monomers such as decyl methacrylate, vinyl decyl ether and high molecular weight olefins with monomers containing polar substituents, e.g., acrylates or • aminoalkyl methacrylates, acrylamides and acrylates 20 substituted with poly- (oxyethylene). These can be characterized as "polymeric dispersants"; in US Patents which are indicated below, examples of them are presented. 3. 329,658 3,666,730 3,449,250 3,687,849 3,519,565 3,702,300 The mentioned patents are incorporated herein by reference as to their descriptions of ashless dispersants. The aforementioned additives, as well as others, may be present in the lubricant compositions in a concentration of only 0.001% by weight, usually in a concentration comprised between 0.01% and approximately 20% by weight. In most cases, they contribute between about 0.1% and about 10% by weight, more often with up to about 5% by weight.

Additive Concentrates The various additive compositions of the present invention described herein can be added directly to the oil of lubricating viscosity. However, it is preferable to dilute them with a normally liquid, substantially inert organic diluent, such as mineral oil, or a synthetic oil such as polyalphaolefin, naphtha, benzene, toluene or xylene, to form an additive concentrate. These concentrates usually constitute between about 0.1 and about 30% by weight, frequently between about 1% and about 20% by weight, more frequently between about 5% and about 15% by weight, of the interpolymers of the present invention and can further contain one or more additives known in the art, or those described herein. additive concentrates are prepared by mixing the desired components, often at elevated temperatures, usually less than about 150 ° C, often no more than about 130 ° C. C, frequently no more than about 115 ° C.

Lubricating oil compositions The interpolymers of the present invention are useful as agents for improving viscosity. They are used in amounts to improve the viscosity, typically in minor amounts, ie less than 50% by weight of the lubricating oil composition, with a larger amount of an oil of lubricating viscosity, i.e. oil of lubricating viscosity constitutes more than 50% by weight of the lubricating oil composition. Preferably, they are used in amounts of between about 0.1 and about 5% by weight, more often between about 0.3 and about 2.5% by weight of the total weight of the lubricating oil composition.

Lubricating viscosity oil The lubricating compositions of the present invention employ an oil of lubricating viscosity, including natural or synthetic lubricating oils and mixtures thereof. Frequently, mixtures of mineral oils and synthetic oils are used, in particular, polyalphaolefin oils and polyester oils. Natural oils include animal oils and vegetable oils (e.g., castor oil, bacon oil and other vegetable oil esters) as well as oils mineral lubricants such as, for example, liquid petroleum oils and mineral lubricating oils treated with j * < > solvent or treated with mixed paraffinic, naphthenic or paraffinic naphthenic acid. Hydrotreated or hydrocracked oils fall within the scope of useful lubricating viscosity oils. Lubricating viscosity oils derived from coal or shale are also useful. Synthetic lubricating oils include hydrocarbon oils and 10 halo-substituted hydrocarbon oils, such as, for example, polymerized and interpolymerized olefins, etc. and mixtures thereof, alkylbenzenes, polyphenyl (e.g., biphenyls, terphenyls, alkylated polyphenyls, etc.), alkylated diphenyl esters and alkylated diphenyl sulfides and their 15 derivatives, analogs and homologs thereof, and the like. The polymers and interpolymers of alkylene oxide and its derivatives, as well as those in which the terminal hydroxyl groups have been modified by esterification, etherification, etc., constitute another class of oils 20 known synthetic lubricants that can be used. Another suitable class of synthetic lubricating oils that can be used is constituted by esters of dicarboxylic acids and those which are composed of monocarboxylic acids from C5 to Ci2 and polyalcohols and polyether 25 polyalcohols. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids, polymeric tetrahydrofurans, alkylated diphenyl oxides and the like. You can use unrefined, refined oils and 30 doubly refined, whether natural or synthetic (as well áfe. -like mixtures of two or more of them) of the type that has been previously described, in the compositions of the present invention. Unrefined oils are those obtained directly from a natural or synthetic source without further purification treatment. Refined oils are similar to unrefined oils with the exception that they have been subsequently treated in one or more purification steps to improve one or more of their properties. Double-refined oils are obtained through processes similar to those used to obtain refined oils applied to refined oils that have been used in service. Said double-refined oils are further treated through techniques directed to eliminate the spent additives and the decomposed products of the oil. Specific examples of lubricating viscosity oils that have been described include those set forth in U.S. Pat. 4,326,972 Chamberlin III, and European Patent Publication 107,282, which are incorporated herein by reference in their relevant descriptions. In an article by D.V. Brock, "Lubrication Engineering", volume 43 page 184-5, March, 1987, which is incorporated herein by reference in its relevant descriptions, sets forth a brief and basic description of lubricating base oils. The following examples serve to illustrate the lubricating oil compositions of the present invention. All parts are by weight. The quantities are based on the material without oil or diluent, with the exception of zv íi. products of the examples set forth herein, which are prepared including diluent, if any.

Examples AB A concentrate of master additive is prepared by combining 1.34 parts of alkylbenzene sulphonic acid overbased with claice (RM 20), 0.62 parts of alkyl benzene sulphonic acid over alkalinized with calcium (RM 2,8), 1.54 parts of alkyl benzene sulfonic acid overbased with magnesium (RM 14.7), 16.60 parts of the reaction product of succinic anhydride-ethylene polyamine substituted with polyisobutylene (Mn ~ 1750), 7.61 parts of isopropyl phosphorodithioate methyl amyl mixed with Zn, 2.78 parts of sulfurized alkyl phenol over alkalinized with calcium (RM 3, 5), 3.19 parts of Diels-Alder adduct of sulfur-containing butyl-butadiene acrylate, 0.08 parts of a commercial silicone anti-foam foam solution, 1 part of succinic acid substituted with polyisobutylene (Mn) - 1000) over alkalinized with sodium (RM 16). 6.85 parts of the reaction product of succinic anhydride-pentaerythritol-ethylene polyamine substituted with polyisobutylene (Mn ~ 1000), 4.84 parts of alkylated diphenyl amine and sufficient mineral oil to bring the total weight of the additive concentrate to 100 parts. The engine oil compositions are prepared by combining 11 parts of the master concentrate, 0.02 parts by weight of a hydrogenated styrene butenediene copolymer and the indicated amount of the indicated example product in a sufficient mineral oil base oil (Petro-Canada SAE 5W-30) to prepare 100 parts by weight of a composition of ff ^ ¿T-j-JH- ^ A- ^ am ^^ iitofea I * oil. In the table below, the details are exposed. (ppp) - parts by weight 5 It is known that some of the described materials can interact in the final formulation, so that the components of the final formulation may be different from those initially added. For example, metal ions 10 (e.g., from a detergent) can move to other acid sites of other molecules. Products formed in this way, including the products formed by employing the composition of the present invention in its intended use, may not be susceptible to easy description. However, all such modifications and reaction products are included within the scope of the present invention; the present invention encompasses the composition prepared by mixing the described components. Each of the documents to which reference has been made is incorporated herein by reference. Except in the examples, or when indicated ^^ $ ^? ^ explicit form, all the numerical quantities of the present description to specify quantities of materials, reaction conditions, molecular weights, numbers of carbon atoms and the like, should be understood as modified by the word "approximately", Unless otherwise indicated, the chemical substances or compositions to which reference is made shall be construed as commercial materials that may contain the isomers, by-products, derivatives and other similar materials, as understood, they are usually present in commercial type materials. However, the amount of each chemical component is present excluding solvents or extender oils that may be present in the usual commercial material, unless otherwise indicated. It should be understood that the range of lower and upper amounts, and the limits of the ratio can be combined independently. As used herein, the expression "consisting essentially of" allows the inclusion of substances that do not materially affect the basic and novel characteristics of the composition under consideration. Although the invention has been explained in relation to the preferable embodiments, it should be understood that various modifications thereof are possible that will be apparent to the person skilled in the art with reading the specification. Therefore, it should be understood that the invention covers such modifications that fall within the scope of the appended claims. i¿ ?? ^^ UM

Claims

1. A lubricating oil composition that includes a major amount of an oil of lubricating viscosity and a minor amount to improve the viscosity of a substantially random interpolymer resulting from the polymerization of (1) from about 19.5 to about 98.5 percent in moles of ethylene; (2) from about 0.5 to about 60 mole percent of one or more vinyl monomers selected from the group consisting of vinyl aromatic, hindered aliphatic and cycloaliphatic monomers; and (3) from about 1 to about 80 mole percent of one or more olefinic monomers having from 3 to about 20 carbon atoms.

2. The lubricating oil composition of claim 1 wherein the component (1) comprises from about 25 to about 95 mole percent of ethylene; component (2) comprises from about 1 to about 55 mole percent of one or more aromatic vinyl monomers or hindered aliphatic or cycloaliphatic vinyl monomers; and component (3) comprises from about 4 to about 65 mole percent of one or more olefinic monomers having from 3 to about 20 carbon atoms.

3. The lubricating oil composition of claim 2, wherein the component (1) comprises from about 30 to about 94 mole percent ethylene; component (2) comprises from about 1 to about 50 mole percent of one or more monomers. aromatic vinyl; and component (3) comprises from about 5 to about 50 mole percent of one or more olefinic monomers having from 3 to about 20 carbon atoms.

4. The lubricating oil composition of claim 1 wherein the interpolymer has a MW of between about 10,000 and about 700,000.

5. The lubricating oil composition of claim 1, wherein the interpolymer is a tere- polymer; component (2) is a vinyl monomer • aromatic; and component (3) is an alpha olefin having from 3 to about 12 carbon atoms.

6. The lubricating oil composition of claim 1, wherein the component (2) is styrene: and the component (3) is one or more olefinic monomers selected from the group consisting of propylene, butene, 1-4. methyl-l-pentene, pentene-1, hexene-1 and octene-1.

7. The lubricating oil composition of claim 2 wherein the interpolymer is a tere- polymer, the component (2) is an aromatic vinyl monomer; and component (3) is an olefinic monomer having from 3 to about 12 carbon atoms. . ^ jAt, »..

8. The lubricating oil composition of claim 1, wherein the interpolymer is a thermal polymer; component (2) is styrene; and the component (3 r is selected from the group consisting of propylene, butenes, hexene-1 and octene-1.

9. The lubricating oil composition of claim 7, wherein the component (2) is styrene; and component (3) is an alpha olefin having from 3 to about 8 carbon atoms.

10. The lubricating oil composition of claim 7, wherein the component (2) is styrene; and component (3) is propylene, butene-1,4-methyl-1-pentene, pentene-1, hexene-1, octene-1 or norbornene.

11. The lubricating oil composition of claim 10, wherein the component (3) is propylene.

12. The lubricating oil composition of claim 10, wherein the component (3) is butene-1.

13. The lubricating oil composition of claim 10, wherein component (3) is hexene-1.

14. The lubricating oil composition of claim 10 wherein component (3) is octene-1.

15. The additive concentrate including from about 0.1% to about 30% by weight of a substantially random interpolymer resulting from the polymerization of 5 (1) from about 19.5 to about 98.5 mole percent of ethylene; (2) from about 0.5 to about 60"'mole percent of one or more vinyl monomers selected from the group consisting of vinyl monomers 10 aromatics, hindered aliphatics and cycloaliphatics; and • (3) from about 1 to about 80 mole percent of one or more olefinic monomers having from 3 to about 20 carbon atoms; and from about 70% to about 99.9% by weight 15 of an organic, normally liquid, substantially inert diluent.

16. The additive concentrate according to claim 15 further including at least one reducing agent of the 20 pour point.

17. The additive concentrate of claim 15, further including at least one organic antioxidant. • t ^ ^ zb »***.! *** ... ** ****! ***! *,