Additive composition

Abstract

 A release additive composition including at least one dispersant viscosity index improver present in a form chosen from a semi-solid and a solid is disclosed.

Description

Field of the Disclosure

[0001] The present disclosure relates to release additive composition comprising at least one dispersant viscosity index improver present in a form chosen from a solid and a semi-solid.

Background of the Disclosure

[0002] Internal combustion engines, in particular diesel fueled engines, generate carbonaceous soot particles. During combustion, the fuel is injected into the combustion chamber in the form of small droplets. Soot particles form from incompletely combusted fuel droplets and can be present on the cylinders and the rings. As the pistons move up and down in the chamber, the soot particles migrate into the lubricating oil system of the pistons, rings, through the cylinder and ultimately into the oil reservoir. Soot may also enter the oil from the EGR system. Accordingly, the soot in the engine oil can contribute to problems with engine lubrication.

[0003] Soot can also be a problem in modern gasoline engines with direct fuel injection systems. The fuel injection system has been designed to produce less emissions and increased power, but has increased the formation of soot in the lubricating oil of the engine. It further requires more frequent oil change intervals to prevent the concentration of soot particles in the oil from exceeding acceptable limits.

[0004] The suspended soot particles in the lubricating oil can have the effect of increasing the viscosity and creating wear particles. Accordingly, soot acts like an abrasive and induces wear in the engine parts. A lubricant composition that comprises a dispersant that is slowly released over the life of the lubricant composition can effect at least one of the following properties, such as minimizing the abrasive soot related wear on an engine, and improving the drain interval of engine oil.

SUMMARY OF THE DISCLOSURE

[0005] In accordance with the disclosure, there is provided a release additive composition comprising at least one dispersant viscosity index improver present in a form chosen from a solid and a semi-solid; a lubricant composition comprising a major amount of a base oil, and a minor amount of a release additive composition comprising at least one dispersant viscosity index improver present in a form chosen from a solid and a semi-solid; and a method for improving the drain interval of engine oil comprising adding to a lubrication system a release additive composition comprising at least one dispersant viscosity index improver present in a form chosen from a solid and a semi-solid.

[0006] Additional objects and advantages of the disclosure will be set forth in part in the description which follows, and can be learned by practice of the disclosure. The objects and advantages of the disclosure will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

[0007] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed.

DESCRIPTION OF THE EMBODIMENTS

[0008] The engines that can use the release additive composition include, but are not limited to internal combustion engines, stationary engines, generators, diesel and/or gasoline engines, on highway and/or off highway engines, two stroke and four stroke cycle engines, aviation engines, piston engines, marine engines, railroad engines, biodegradable fuel engines and the like. In one embodiment, the engine can be equipped with after-treatment devices, such as exhaust gas recirculation systems, catalytic converters, diesel particulate filters, NO_x traps, and the like.

[0009] In accordance with the present disclosure, the level and agglomeration of soot in engine oil can be decreased by using the release additive composition thereby effecting at least one of the following properties: reducing deposit formation and soot agglomeration, increasing the maintenance time interval on a vehicle, and extending the engine life. Moreover, the soot level can be reduced by contact of the lubricating composition with the release additive composition. It is believed, without being limited to any particular theory, that the use of the disclosed release additive composition can achieve at least one of the above disclosed properties because the disclosed dispersant viscosity index improver will be slowly released into the lubricating composition and will be present over the life of the lubricating composition. One of ordinary skill in the art would understand that the life of the lubricating composition is dependent upon several factors including, but not limited to, engine operation, engine type, engine service, mileage of the vehicle, quality of the base oil in the lubricating composition, etc.

[0010] The term "release" as used herein is understood to mean that the components of the additive composition are released over an extended period of time, e.g., over the life of the lubricating composition. The release rate can be moderated by several factors, such as, the location of the additive composition in the lubrication system, the additive composition formulation, the form of the composition, and/or the mode of addition of the additive composition into a lubricating composition. One of ordinary skill in the art can modify any and/or all of the above factors in order to obtain the desired release rate of the additive composition.

[0011] The release additive composition can be located anywhere within a lubrication system so long as the additive composition will be in contact with a lubricating composition. For example, the release additive composition can be located in at least one of a filter, drain pan, oil bypass loop, canister, housing, reservoir, pockets of a filter, canister in a filter, mesh in a filter, canister in a bypass system, mesh in a bypass system, and the like. In an embodiment, the lubrication system can comprise an oil filter. The oil filter can comprise the release additive composition disclosed herein.

[0012] In another embodiment, the oil filter can comprise a housing, such as a sleeve or cup, that can be partitioned, for example with a non-diffusible barrier, thereby creating at least one pocket. Each pocket can comprise an identical, similar and/or a different release additive composition wherein the composition can be in an identical, similar and/or different form, such as a semi-solid or solid form. A non-limiting example of this concept includes one pocket comprising a release additive composition comprising a dispersant viscosity index improver in a solid form and an antioxidant in a semi-solid form and a second pocket comprising a release additive composition comprising a dispersant viscosity index improver in a semi-solid form. The filter can be a desirable location to place the release additive composition because the additive composition and/or spent additive composition can easily be removed and then replaced with a new and/or recycled additive composition.

[0013] In yet another embodiment, the release additive can be located anywhere within the lubrication system. For example, the release additive can be located outside of an oil filter on the "dirty" side or it can be located inside of the oil filter on the "clean" side. One of ordinary skill in the art would understand that the location of the release additive in the lubrication system is not critical so long as the release additive composition is in contact with a lubricating composition.

[0014] Moreover, the release rate of the release additive formulation can be moderated by the formulation and/or the form of the additive composition. For example, the release additive composition can comprise at least one component that selectively dissolves completely or that is poorly oil-soluble and thus remains till the end of its service life, or combinations thereof. The release rate can also be moderated by the polymer's molecular weight, the degree of graft ("DOG"), polymer content, and type of capping amine. In general, as the molecular weight, DOG or polymer content increases for the dispersant viscosity index improver, the release rate into a lubricating composition can be expected to be slow. Selection of the capping amine can also be a factor in the release rate. For example, some capping amines cross-link, hydrogen bond or have some other solubilizing affect that can serve to either increase the rate or reduce the rate at which a product can dissolve into a lubricating composition.

[0015] Further, the additive composition can be in the form of a semi-solid, solid, or combinations thereof. Non-limiting examples include an oil filter comprising a dispersant viscosity index improver in a semi-solid form, an oil filter comprising a dispersant viscosity index improver in a solid form and an antioxidant in a semi-solid form, and an oil filter comprising a dispersant viscosity index improver in a solid form and an overbased detergent in a semi-solid form. A "semi-solid" form as used herein is understood to mean one component having rigidity and viscosity intermediate between a solid and a liquid, for example the one component is not a liquid or free flowing at room temperature (23°C).

[0016] Moreover, the release rate of the additive composition can be controlled by varying the degree of solidity of the composition. For example, a semi-solid additive composition can have a faster release rate into a lubricating composition as compared to a solid additive composition. One of ordinary skill in the art can select the form of the additive composition based upon the desired release rate.

[0017] The release additive composition can be added to the lubrication system by any known method depending on the desired form of the additive composition, the desired speed of addition, the desired release rate, the desired mode of operation and/or any of the combinations of the above. In an embodiment, the additive composition can be a semi-solid and can be added to the lubrication system by means of an injector pump, or a container in an oil filter. In another embodiment, the additive composition can be a solid and can be introduced into the lubricating oil system by means of an auger. It is contemplated that the release additive composition can be released into a lubricating composition slowly over a long period of time, such as the life of the lubricating composition, or quickly over a short period of time, but remain in the lubricating composition over the life of the lubricating composition.

[0018] A lubricating composition can comprise a minor amount of the release additive composition. A "minor amount" as used herein is understood to mean less than about 50%, such as for example less than about 40%, and as a further example from less than about 30% by weight relative to the total weight in the lubricating composition.

[0019] In embodiments, the lubricating composition can also comprise a major amount of a base oil. The base oil can be selected from, for example, natural oils such as mineral oils, vegetable oils, paraffinic oils, naphthenic oils, aromatic oils, synthetic oils, derivatives thereof, and mixtures thereof. The synthetic oils can comprise at least one of an oligomer of an alpha-olefin, an ester, an oil derived from a Fischer-Tropsch process, and a gas-to-liquid stock. A "major amount" can be understood to mean greater than or equal to about 50%.

[0020] In accordance with the present disclosure, a release additive composition can comprise at least one dispersant viscosity index improver. The dispersant viscosity index improver can be a functionalized olefin copolymer. The polymer or copolymer substrate can be prepared from ethylene and propylene or it can be prepared from ethylene and at least one higher olefin within the range of C₃ to C₂₃ alpha-olefins.

[0021] Non-limiting examples of polymers for use herein include copolymers of ethylene and at least one C₃ to C₂₃ alpha-olefins. In an embodiment, copolymers of ethylene and propylene can be used. Other alpha-olefins suitable in place of propylene to form the copolymer or to be used in combination with ethylene and propylene to form a terpolymer include 1-butene, 2-butene, isobutene, 1-pentene, 1-hexene, 1-octene and styrene; α,ω.-diolefins such as 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene; branched chain alpha-olefins such as 4-methylbutene-1,5-methylpentene-1, and 6-methylheptene-1; and mixtures thereof.

[0022] More complex polymer substrates, often designated as interpolymers, can be prepared using a third component. The third component generally used to prepare an interpolymer substrate can be a polyene monomer selected from non-conjugated dienes and trienes. The non-conjugated diene component can be one having from 5 to 14 carbon atoms in the chain. For example, the diene monomer can be characterized by the presence of a vinyl group in its structure and can include cyclic and bicyclo compounds. Representative dienes include 1,4-hexadiene, 1,4-cyclohexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-methylene-2-norborene, 1,5-heptadiene, and 1,6-octadiene. A mixture of more than one diene can be used in the preparation of the interpolymer. In an embodiment, a non-conjugated diene for preparing a terpolymer or interpolymer substrate can be 1,4-hexadiene.

[0023] The triene component can have at least two non-conjugated double bonds, and up to about 30 carbon atoms in the chain. Typical trienes useful in preparing the interpolymer of the invention can be 1-isopropylidene-3α,4,7,7α.-tetrahydroindene, 1-isopropylidenedicyclopentadiene, dihydro-isodicyclopentadiene, and 2-(2-methylene-4-methyl-3-pentenyl)(2.2.1) bicyclo-5-heptene.

[0024] Ethylene-propylene or higher alpha-olefin copolymers can comprise from about 15 to 80 mole percent ethylene and from about 85 to 20 mole percent C₃ to C₂₃ alpha-olefin with, for example, mole ratios from about 35 to 75 mole percent ethylene and from about 65 to 25 mole percent of a C₃ to C₂₃ alpha-olefin, with for example proportions being from 50 to 70 mole percent ethylene and 50 to 30 mole percent C₃ to C₂₃ alpha-olefin, and as a further example proportions being from 55 to 65 mole percent ethylene and 45 to 35 mole percent C₃ to C₂₃ alpha-olefin.

[0025] Terpolymer variations of the foregoing polymers can comprise from about 0.1 to 10 mole percent of a non-conjugated diene or triene.

[0026] The terms polymer and copolymer can be used generically to encompass ethylene copolymers, terpolymers or interpolymers. These materials can comprise minor amounts of other olefinic monomers so long as the basic characteristics of the ethylene copolymers are not materially changed.

[0027] The polymerization reaction used to form the ethylene-olefin copolymer substrate can be generally carried out in the presence of a conventional Ziegler-Natta or metallocene catalyst system. The polymerization medium is not specific and can include solution, slurry, or gas phase processes, as known to those skilled in the art. When solution polymerization is employed, the solvent can be any suitable inert hydrocarbon solvent that is liquid under reaction conditions for polymerization of alpha-olefins. Non-limiting examples of satisfactory hydrocarbon solvents include straight chain paraffins having from about 5 to about 8 carbon atoms, such as hexane. Aromatic hydrocarbons, for example an aromatic hydrocarbon having a single benzene nucleus, such as benzene, toluene and the like; and saturated cyclic hydrocarbons having boiling point ranges approximating those of the straight chain paraffinic hydrocarbons and aromatic hydrocarbons described above, can be suitable. The solvent selected can be a mixture of at least one of the foregoing hydrocarbons. When slurry polymerization is employed, the liquid phase for polymerization can be, for example, liquid propylene. In an embodiment, the polymerization medium can be free of substances that will interfere with the catalyst components.

[0028] The number average molecular weight as determined by gel permeation chromatography, Mn, of the copolymer substrate can be from about 700 to about 500,000, and for example from about 700 to about 100,000. The molecular weight distribution, Mw/Mn, of the polymer substrate can be less than about 15, for example from about 1 to about 10.

[0029] An ethylenically unsaturated carboxylic acid material can next be grafted onto the prescribed polymer backbone to form an acylated ethylene copolymer. These carboxylic reactants which are suitable for grafting onto the ethylene copolymer contain at least one ethylenic bond and at least one, for example two, carboxylic acid or its anhydride groups or a polar group which is convertible into said carboxyl groups by oxidation or hydrolysis. For example, the carboxylic reactants can be selected from acrylic, methacrylic, cinnamic, crotonic, maleic, fumaric and itaconic reactants. As a further example, the carboxylic reactants can be selected from maleic acid, fumaric acid, maleic anhydride, and a mixture of two or more of these. Maleic anhydride or a derivative thereof can be used, for example, due to its commercial availability and ease of reaction. In the case of unsaturated ethylene copolymers or terpolymers, itaconic acid or its anhydride can be used due to its reduced tendency to form a cross-linked structure during the free-radical grafting process.

[0030] The ethylenically unsaturated carboxylic acid materials typically can provide one or two carboxylic groups per mole of reactant to the grafted polymer. That is, methyl methacrylate can provide one carboxylic group per molecule to the grafted polymer while maleic anhydride can provide two carboxylic groups per molecule to the grafted polymer.

[0031] The carboxylic reagent, such as maleic anhydride, can be grafted onto the polymer backbone in an amount from about 0.5 to about 4.0 grams of carboxylic reagent per 100 grams of polymer and can be expressed as a wt%. For example, if a 10,000 mol. wt. polymer was reacted with enough maleic anhydride to form a product that contained 1.8 grams of maleic anhydride per 100 gms of polymer backbone, then the resultant grafted product would be a 10,000 mol. wt. E-P copolymer with a DOG of 1.8 wt%. Co-incidentally, this additive would contain 1.8 molecules of maleic anhydride per polymer molecule. This maleic anhydride to polymer ratio could be described as the carboxylic reagent to olefin copolymer ratio. In a second example, if a 20,000 mol. wt E-P copolymer was reacted with 1.8 gms of maleic anhydride per 100 gms of E-P polymer, then the resultant product would be a 20,000 mol. wt. E-P copolymer with a DOG of 1.8 wt% and a carboxylic reagent to olefin copolymer ratio of 3.6. In a third example, a nominal 70,000 molecular weight E-P polymer with a DOG of 1.8 wt% would have a carboxylic reagent to olefin polymer ratio of 12.6. In an embodiment, at a minimum, one molecule of carboxylic reagent per one polymer molecule can be used.

[0032] The grafting reaction to form the acylated olefin copolymers can be generally carried out with the aid of a free-radical initiator either in solution or in bulk, as in an extruder or intensive mixing device. When the polymerization is carried out in hexane solution, it can be economically convenient to carry out the grafting reaction in hexane as described in U.S. Pat. Nos. 4,340,689, 4,670,515 and 4,948,842, the disclosures of which are hereby incorporated by reference. The resulting polymer intermediate can be characterized by having carboxylic acid acylating functionality randomly within its structure.

[0033] In the bulk process for forming the acylated olefin copolymers, the olefin copolymer can be fed to rubber or plastic processing equipment such as an extruder, intensive mixer or masticator, heated to a temperature of about 150°C to about 400°C and the ethylenically unsaturated carboxylic acid reagent and free-radical initiator can be separately co-fed to the molten polymer to effect grafting. The reaction can be carried out optionally with mixing conditions to effect shearing and grafting of the ethylene copolymers according to U.S. Pat. No. 5,075,383, incorporated herein by reference. The processing equipment can be generally purged with nitrogen to prevent oxidation of the polymer and to aid in venting unreacted reagents and byproducts of the grafting reaction. The residence time in the processing equipment can be sufficient to provide for the desired degree of acylation and to allow for purification of the acylated copolymer via venting. Mineral or synthetic lubricating oil can optionally be added to the processing equipment after the venting stage to dissolve the acylated copolymer.

[0034] The free-radical initiators which can be used to graft the ethylenically unsaturated carboxylic acid material to the polymer backbone include peroxides, hydroperoxides, peresters, and also azo compounds and, for example, those which have a boiling point greater than about 100°C and decompose thermally within the grafting temperature range to provide free radicals. Representatives of these free-radical initiators can be azobutyronitrile, dicumyl peroxide, 2,5-dimethylhexane-2,5-bis-tertiarybutyl peroxide and 2,5-dimnethylhex-3-yne-2,5-bis-tertiary-butyl peroxide. The initiator can be used in an amount from about 0.005% to about 1% by weight based on the weight of the reaction mixture.

[0035] Other methods known in the art for effecting reaction of ethylene-olefin copolymers with ethylenically unsaturated carboxylic reagents, such as halogenation reactions, thermal or "ene" reactions or mixtures thereof, can be used instead of the free-radical grafting process. Such reactions are conveniently carried out in mineral oil or bulk by heating the reactants at temperatures from about 250°C to about 400°C under an inert atmosphere to avoid the generation of free radicals and oxidation byproducts.

[0036] The acylated olefin copolymers can be reacted with coupling compounds and performance enhancing compounds. The reaction sequence can be in any order or simultaneous. In an embodiment, the performance enhancing compound can be first reacted with an oil or solvent solution of the acylated olefin copolymer followed by addition of the coupling compound. Because both reactants combine with the free carboxylic functionality of the acylated copolymers, the ratio of coupling compound to the performance enhancing compound can be adjusted as well as the ratio of coupling compound and performance enhancing compound to acylated olefin copolymer to provide for the desired balance of viscosity index improvement-dispersancy and additional performance criteria.

[0037] For purposes of the present disclosure, coupling compounds can be defined as those compounds containing more than one amine, thiol and/or hydroxy functional groups capable of reacting with the acylated olefin copolymer so as to link or couple two or more acylated olefin copolymers.

[0038] Coupling compounds for use herein include organo polyamines, polyalcohols, polyhydroxy or thiol amines, amide-amines and amino guanidines wherein the organo group can be aliphatic, cycloaliphatic, aromatic, heterocyclic, or combinations thereof, and wherein the organo group can have organo heteroatom containing groups such as but not limited to --O--, --N--, --S--, --Siand --P--.

[0039] Representative organo polyamines include triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, di-(1,3-propylene)triamine, tri-(1,3-propylene) tetramine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, N,N-di-(2-aminoethyl)ethylene diamine, N,N-di-(2-aminoethyl) propylene diamine, N-(oleayl amino propyl)1,3-propylene diamine, 1,4-bis(2-aminoethyl) piperazine, polyethylene amine mixtures containing 5-7 N-atoms per molecule commercially available under the trade names Polyamine H, Polyamine 400, or Dow Polyamine E-100, and aromatic diamine mixtures such as ETHACURE^® 300 (Albemarle Corporation) which is a mixture of 2,4- and 2,6-isomers of dimethylthiotoluene diamine.

[0040] Branched or star branched polyamines also known in the art as dendrimers can be used. Such dendrimers are described in, for example, U.S. Pat. Nos. 4,587,329 and 4,737,550 and PCT published applications Nos. WO93/14147 and WO95/02008, the disclosures of which are hereby incorporated by reference. A core group and repeating structural unit linked by a functional group defines the dendrimers. The repeating units can be referred to as generations. Typically, polyamine dendrimers having 1 to 4 generations linked together via amine groups and terminated by a primary amine can be particularly useful. A typical polyamine dendrimer can be prepared, for example, with 1,4-diaminobutane as the core, which can then be reacted via a Michael addition with acrylonitrile followed by hydrogenation of the cyano group to a primary amine. A second generation of alternating reactions with acrylonitrile, followed by hydrogenation will yield a polyamine with eight branches. Examples of useful core molecules include, but are not limited to, ammonia, polymethylenediamines, diethylenetriamines, diethylene tetramines, tetraethylenepentamine, linear and branched polyethylene imines, polyaminoalkylarenes, such as 1,3,5-tris-(aminomethyl) benzene, and melamine and its derivatives such as melamine tris-(hexamethylene diamine). Particularly useful as chemical compounds in forming the generations can be α, β-unsaturated carboxylic and cyano compounds, aziridines and alkylene diamines.

[0041] Other suitable organo polyamines include polyoxyalkylene polyamines such as those of the formula: NH₂ -alkylene-(--O--alkylene)_n --NH₂
where n can have a value of about 3 to about 59, for example about 10 to about 35 and the alkylene groups can be independently straight or branched chains containing about 2 to about 7, for example about 2 to about 4, carbon atoms. As well as polyoxyalkylene polyamines of the formula:

         R¹-(-alkylene-(--O--alkylene)_m --NH₂)_a

where m can have a value of about 1 to about 28 with the provision that the sum of all carbon atoms is from about 2 to about 60, from example about 2 to about 40, and R¹ can be a polyvalent saturated hydrocarbon radical of up to ten carbon atoms wherein the number of substituents on the R¹ group can be represented by the value 'a', which can be a number from 3 to 6. The alkylene groups can be independently straight or branched chains containing about 2 to about 7, for example from about 2 to about 4, carbon atoms.

[0042] The polyoxyalkylene polyamines described above can be, for example, polyoxyalkylene diamines and polyoxyalkylene triamines having an average molecular weight ranging from about 200 to about 4000, for example from about 400 to about 2000. The polyoxyalkylene polyamines include the polyoxyethylene and polyoxypropylene diamines and the polyoxyproylene triamines having average molecular weights ranging from about 200 to 2000. The polyoxyalkylene polyamines can be commercially available and can be obtained, for example, from Huntsman Chemical Company under the trade name "Jeffamines D-230, D-400, D-1000, D-2000, T-403", etc.

[0043] Another particularly suitable class of organo polyamines comprise bis(p-amino cyclohexyl) methane (PACM) and oligomers and mixtures of PACM with isomers and analogs thereof containing on average, from 2 to 6 or higher, for example 3 to 4, cyclohexyl rings per PACM oligomer molecule. The total nitrogen content of the PACM oligomers can comprise from 8 to 16 wt. %, and for example from 10 to 14 wt. %.

[0044] The PACM oligomers can be obtained, e.g., by fractionation or distillation, as a heavies by-product or bottoms from the PACM-containing product produced by high pressure catalytic hydrogenation of methylene dianiline. The hydrogenation of methylene dianiline and the separation of PACM oligomers from the resulting hydrogenation product can be accomplished by known means, including the processes disclosed in U.S. Pat. Nos. 2,511,028; 2,606,924; 2,606,925; 2,606,928; 3,914,307; 3,959,374; 4,293,687; 4,394,523; 4,448,995 and 4,754,070, the disclosures of which are incorporated herein by reference in their entirety.

[0045] Suitable polyalcohol coupling compounds useful herein include polyol compounds containing at least two reactive hydroxy groups. The polyalcohols generally comprise up to about 100 carbon atoms and from 2 to about 10, for example about 3 to about 8 hydroxy groups per molecule. These polyols can be quite diverse in structure and chemical composition. For example, they can be substituted or unsubstituted, hindered or unhindered, branched chain or straight chain, etc. as desired. Typical polyols include alkylene glycols such as ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol, and polyglycol such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, dibutylene glycol, tributylene glycol, and other alkylene glycols and polyalkylene glycols in which the alkylene radical contains from about two to about eight carbon atoms. Other useful polyalcohols include glycerol, monomethyl ether of glycerol, trimethylopropane, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2-propanediol, 1,2-butanediol, 1,4-butanediol, 2,3-hexanediol, pinacol, erythritol, arabitol, sorbitol, mannitol etc.

[0046] Cyclic poly(methylol) compounds, such as 2,2,6,6-tetramethylol cyclohexanol, tetrahydro-3,3,5,5-tetrakis-(hydroxymethyl)-4-pyranol, tetrahydro-3,3,5-tris-(hydroxymethyl)-5-methyl-4-pyranol, as well as heterocyclic polyols can also be used as coupling compounds in the present disclosure. The heterocyclic polyols and cyclic poly(methylol) compounds can be described more fully in U.S. Pat. No. 4,797,219, the disclosure of which is incorporated herein in its entirety.

[0047] Organo polyhydroxy or thiol amines particularly useful herein include 2-(2-aminoethyl)aminoethanol, N-(2-hydroxypropyl) ethylene diamine, N,N-di-(2-hydroxyethyl) 1,3-propylene diamine, hexamethylene diamine-2-propylene oxide (HMDA-2PO), hexamethylene diamine-3-propylene oxide (HMDA-3PO), hexamethylene diamine-4-propylene oxide (HMDA-4PO), dimethyl aminopropylamine-2-propylene oxide (DMAPA-2PO), and Mannich condensation products which can be formed from a hydroxyaromatic compound (e.g., phenol, alkyl substituted phenol etc.), an aldehyde (e.g., formaldehyde, formalin, clyoxal etc.), and a polyalkenyl polyamine (e.g., pentaethylene hexamine and tetraethylene pentamine). Suitable polythiol amines include aminomercaptotriazoles.

[0048] Organo amide-amines include the linear and branched products from the reaction of alkylene diamines and alkylacrylates such as ethylene diamine and methyl acrylate or 1,4-butane diamine and methyl acrylate. Amido-amine dendrimers, described in U.S. Pat. Nos. 4,587,329 and 4,737,550, are prepared by alternating reactions with alkylene diamines and alkyl acrylates or acrylamides. Amido-amine dendrimers having up to 4 generations can be used to couple the acylated olefin polymers.

[0049] Also useful are the amino guanidines such as amino guanidine bicarbonate (AGBC).

[0050] The performance enhancing compound includes a polyamine compound selected from:

(a) an N-arylphenylenediamine represented by the formula:

wherein R¹ can be hydrogen, --NH-aryl, --NH-arylalkyl, --NH-alkyl, or a branched or straight chain radical having from about 4 to about 24 carbon atoms that can be alkyl, alkenyl, alkoxyl, aralkyl, alkaryl, hydroxyalkyl or aminoalkyl; R² can be --NH₂, CH₂ --(CH₂)_n --NH₂, CH₂ -aryl-NH₂, in which n has a value from 1 to 10; and R³ can be hydrogen, alkyl, alkenyl, alkoxyl, aralkyl, alkaryl having from about 4 to about 24 carbon atoms;

(b) an aminothiazole selected from the group consisting of aminothiazole, aminobenzothiazole, aminobenzothiadiazole and aminoalkylthiazole;

(c) an aminocarbazole represented by the formula:

wherein R and R¹ can be the same or different, and can be hydrogen, an alkyl, alkenyl, or alkoxy radical having from about 1 to about 14 carbon atoms; (d) an aminoindole represented by the formula:

wherein R can be hydrogen or an alkyl radical having from about 1 to about 14 carbon atoms;

(e) an aminopyrrole represented by the formula:

wherein R can be a divalent alkylene radical having from about 2 to about 6 carbon atoms and R¹ can be hydrogen or an alkyl radical having from about 1 to about 14 carbon atoms;

(f) an amino-indazolinone represented by the formula:

wherein R can be hydrogen or an alkyl radical having from about 1 to about 14 carbon atoms;

(g) an aminomercaptotriazole represented by the formula:

wherein R can be absent or can be a C₁-C₁₀ linear or branched hydrocarbon selected from the group consisting of alkyl, alkenyl, arylalkyl, and aryl;

(h) an aminoperimidine represented by the formula:

wherein R can be hydrogen, an alkyl, or alkoxyl radical having from about 1 to about 14 carbon atoms;

(i) aminoalkyl imidazoles, such as 1-(2-aminoethyl) imidazole, 1-(3-aminopropyl) imidazole; and

(j) aminoalkyl morpholines, such as 4-(3-aminopropyl) morpholine.

[0051] In one aspect of the disclosure, the polyamines for use herein can be the N-arylphenylenediamines, for example the N-phenylphenylenediamines, and as a further example, N-phenyl-1,4-phenylenediamine, N-phenyl-1,3-phenylendiamine, and N-phenyl-1,2-phenylenediamine.

[0052] The polyamines can contain only one primary amine group so as to avoid coupling and/or gelling of the olefin copolymers.

[0053] The reaction between the acylated olefin polymer and the coupling compound and/or performance enhancing compound, such as the polyamine, can be conveniently carried out in natural or synthetic lubricating oil under inert conditions. In an embodiment, a surfactant is not used. The ingredients can be agitated at a temperature from about 120° to 200°C, for example 140° to 180°C with a purge of inert gas to remove water and/or other low molecular weight byproducts. The reaction time can vary from about 30 minutes to about 16 hours.

[0054] The composition can also include other additives such as dispersants, non-dispersant viscosity index improver, overbased detergents, antioxidants, detergents, graphite, molybdenum disulfide, magnesium carbonate, silica, alumina, titania, magnesium oxide, calcium carbonate, lime, clay, zeolites, extreme pressure (EP) agents, wear reduction agents, anti-foaming agents, friction reducing agents, anti-misting agents, cloud-point depressants, pour-point depressants, mineral and/or synthetic oils mixtures thereof and combination thereof. These additives can be used alone or in combination. These additives can be used alone or in combination, such as in an optional additional additive package.

[0055] Lubricant compositions, such as modern motor oils, can be made by combining a pre-formed additive package with a refined or synthetic base oil stock. A lubricant composition can comprise various different lubricant additive packages. Because lubricant additives can be easier to handle and measure in liquid form those additives which are normally solid can be dissolved in small amounts of base oil stock.

[0056] In one embodiment, there is disclosed a method for improving the drain interval of an engine oil comprising adding to a lubrication system the disclosed release additive composition.

EXAMPLES

Example 1 - Nominal 66,000 Mol. Wt. Ethylene-Propylene Polymer

[0057] Into a round bottom flask equipped with a mechanical stirrer, air inlet tube, thermocouple and condenser was added 300 gms of a ethylene-propylene copolymer with a degree of graft of 1.99 wt% maleic anhydride, PA-1275 manufactured by DSM for Afton Chemical. The reactant was blanketed with nitrogen gas and heated to 160°C. With vigorous stirring, the capping amine, n-phenyl-phenylene diamine (1.4 gms) was added to the reaction. The reaction was stirred for one hour at 160°C. Analytical data: %N = 0.088 wt%. The product solidified upon cooling.

Example 2 - Nominal 20,000 Mol. Wt. Ethylene-Propylene Polymer

[0058] Into a round bottom flask equipped with a mechanical stirrer, air inlet tube, thermocouple and condenser was added 600 gms of a 20,000 mol. wt. ethylene-propylene copolymer with a degree of graft of 2.1 wt% maleic anhydride. The reactant was blanketed with nitrogen gas and heated to 160°C. With vigorous stirring, the capping amine, n-phenyl-phenylene diamine (4.7 gms) was added to the reaction. The reaction was stirred for two hours at 160°C. Analytical data: %N = 0.14 wt%. The product solidified upon cooling.

Example 3 - Nominal 10,000 Mol. Wt. Ethylene-Propylene Polymer

[0059] Into a round bottom flask equipped with a mechanical stirrer, air inlet tube, thermocouple and condenser was added 600 gms of a 10,000 mol. wt. ethylene-propylene copolymer with a degree of graft of 1.76 wt.% maleic anhydride. The reactant was blanketed with nitrogen gas and heated to 160°C. With vigorous stirring, the capping amine, n-phenyl-phenylene diamine (6.5 gms) was added to the reaction. The reaction was stirred for two hours at 160°C. Analytical data: %N = 0.19 wt%. The product solidified upon cooling.

Example 4 - Nominal 20,000 Mol. Wt. Ethylene-Propylene Polymer

[0060] Into a round bottom flask equipped with a mechanical stirrer, air inlet tube, thermocouple and condenser was added 600 gms of a 20,000 mol. wt. ethylene-propylene copolymer with a degree of graft of 2.1 wt% maleic anhydride. The reactant was blanketed with nitrogen gas and heated to 160°C. With vigorous stirring, the capping amine, amino guanidine bicarbonate, (3.5 gms) was added to the reaction. The reaction was stirred for two hours at 160°C or until the product was too thick to stir. Analytical data: %N = 0.267 wt%. The product solidified upon cooling.

Example 5 - Nominal 20,000 Mol. Wt. Ethylene-Propylene Polymer

[0061] Into a round bottom flask equipped with a mechanical stirrer, air inlet tube, thermocouple and condenser was added 600 gms of a 20,000 mol. wt. ethylene-propylene copolymer with a degree of graft of 2.1 wt% maleic anhydride. The reactant was blanketed with nitrogen gas and heated to 160°C. With vigorous stirring, the capping amine, n-phenyl-phenylenediamine, 3.5 gms, was slowly added to the reaction. The reaction was stirred for 1 hour at 160°C. Amino guanidine bicarbonate, 0.87 gms, was slowly added to the reaction. The reaction was stirred for 1 hour at 160°C. Analytical data: %N = 0.216 wt%. The product solidified upon cooling.

[0062] For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0063] It is noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the," include plural referents unless expressly and unequivocally limited to one referent. Thus, for example, reference to "an antioxidant" includes two or more different antioxidants. As used herein, the term "include" and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.

[0064] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or can be presently unforeseen can arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they can be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.

Claims

1. A release additive composition comprising at least one dispersant viscosity index improver present in a form chosen from a solid and a semi-solid.

2. A composition according to claim 1, wherein the at least one dispersant viscosity index improver is a solid.

3. A composition according to claim 1, wherein the at least one dispersant viscosity index improver is a semi-solid.

4. A composition according to any one of claims 1 to 3, wherein the at least one dispersant viscosity index improver has a number average molecular weight from about 700 to about 500,000.

5. A composition according to claim 4, wherein the at least one dispersant viscosity index improver has a number average molecular weight from about 700 to about 100,000.

6. A composition according to any one of claims 1 to 5, wherein the at least one dispersant viscosity index improver has a degree of graft ranging from about 1.0 to about 3.0.

7. A composition according to any one of claims 1 to 6, wherein the at least one dispersant viscosity index improver comprises an amine chosen from N-phenyl-phenylene diamine and amino guanidine bicarbonate.

8. A composition according to any one of claims 1 to 7, further comprising an antioxidant.

9. A composition according to claim 8, wherein the antioxidant is a semi-solid.

10. A composition according to either claim 8 or claim 9, wherein the antioxidant is an alkyl-substituted phenol.

11. A lubricant composition comprising:

a major amount of a base oil; and

a minor amount of a release additive composition according to any one of claims 1 to 10.

12. A lubricant composition according to claim 11, wherein the base oil is selected from the group consisting of mineral oils, vegetable oils, paraffinic oils, naphthenic oils, aromatic oils, synthetic oils, derivatives thereof, and mixtures thereof.

13. A lubrication system comprising at least one release additive composition according to any one of claims 1 to 10 located in at least one of a filter, drain pan, oil bypass loop, canister, housing, reservoir, pockets of a filter, canister in a filter, mesh in a filter, canister in a bypass system and mesh in a bypass system.

14. A system according to claim 13, wherein the release additive composition is located in the filter.

15. A system according to either claim 13 or claim 14, wherein the filter comprises at least one pocket, and wherein each of the at least one pocket comprises the at least one release additive composition.

16. A system according to claim 15, wherein each of the at least one pocket comprises a different at least one release additive composition.

17. Use of a release additive composition according to any one of claims 1 to 10 for improving the drain interval of engine oil.