GIESELMAN MATT D (US)
EVELAND RENEE A (US)
PIKE PHILIP (US)
PUDELSKI JOHN (US)
COVITCH MICHAEL J (US)
FRIEND CHRISTOPHER (GB)
KOLP CHRISTOPHER (US)
GIESELMAN MATT D (US)
EVELAND RENEE A (US)
PIKE PHILIP (US)
PUDELSKI JOHN (US)
COVITCH MICHAEL J (US)
FRIEND CHRISTOPHER (GB)
WO2001098387A2 | 2001-12-27 |
EP0396297A2 | 1990-11-07 | |||
US6107257A | 2000-08-22 | |||
US4904401A | 1990-02-27 |
1. | A composition comprising the reaction product of: (a) an isobutylenediene copolymer having an M∏ of about 1000 to about 150,000 and containing thereon an average of about 0.1 to 4 equivalents, per each 1000 units of Mn of the polymer, of carboxylic acid functionality or reactive equivalent thereof, derived from at least one α,βunsaturated carbox¬ ylic compound; and (b) an amine component comprising at least one aromatic amine contain ing at least one NH group capable of condensing with said carboxylic acid functionality. |
2. | The composition of claim 1 wherein the diene is selected from the group consisting of isoprene, piperylene, 1,3butadiene, and limonene. |
3. | The composition of claim 1 wherein the diene comprises isoprene. |
4. | The composition of claim 1 wherein (a) the copolymer containing carboxylic acid functionality is prepared by reacting (i) an isobutylenediene copolymer having on average about 1 to about 150 moles of reactive carbon carbon double bonds per mole of copolymer and about 0.1 to about 2 moles of said double bonds per 1000 units of Mn of the copolymer, with (ii) an α,β unsaturated carboxylic compound. (' 5. |
5. | The composition of claim 1 wherein the α,βunsaturated carboxylic compound comprises an acrylic compound, a methacrylic compound, a maleic compound, a fumaric compound, or an itaconic compound. |
6. | The composition of claim 1 wherein the α,βunsaturated carboxylic compound comprises maleic anhydride. |
7. | The composition of claim 1 wherein the amine component is selected from the group consisting of 4phenylazoaniline, 4aminodiphenylamine, 2 aminobenzimidazole, 3nitroaniline, 4(4nitrophenylazo)aniline, N(4amino5 methoxy2methylphenyl)benzamide, N(4amino2,5dimethoxyphenyl) benzamide, N(4amino2,5diethoxyphenyl)benzamide, N(4aminophenyl) benzamide, 4amino2hydroxybenzoic acid phenyl ester, and N, Ndimethyl phenylenediamine. |
8. | The composition of claim 1 wherein the amine component further comprises an amine having at least two NH groups capable of condensing with said carboxylic acid functionality . |
9. | The composition of claim 8 wherein the amine having at least two N H groups comprises ethylenediamine, 2,4diaminotoluene, or phenylenediamine. |
10. | A lubricant composition comprising a major amount of an oil of lubricating viscosity and a minor amount of the composition of claim 1. |
11. | The lubricant composition of claim 10 further comprising at least one additive selected from the group consisting of detergents, dispersants, viscosity modifiers, pour point depressants, friction modifiers, antioxidants, and an ti wear agents. |
12. | The lubricant composition prepared by admixing the components of claim 11. |
13. | The lubricant composition of claim 10 further comprising a polyiso butene succinimide dispersant having a N:CO ratio of greater than about 1. |
14. | The lubricant composition of claim 10 further comprising a hydro genated copolymer of a vinylaromatic monomer with a conjugated polyene. |
15. | A process for lubricating an internal combustion engine, comprising supplying thereto the lubricant of claim 10. |
16. | A process for improving the viscosity index of a lubricating oil composition comprising incorporating into said composition a minor, viscosity improving amount, of the composition of claim 1. |
17. | A process for reducing sootinduced viscosity increase in a lubricat¬ ing oil composition comprising incorporating into said composition a minor, viscosityimproving amount, of the composition of claim 1. |
18. | A concentrate comprising the composition of claim 1 and a concen¬ trateforming amount of an oil of lubricating viscosity. |
19. | A process for preparing a carboxylic derivative composition, com¬ prising: (a) reacting (i) an isobutylenediene copolymer having an Mn of about 1000 to about 150,000 and having on average about 0.1 to about 2 units of reactive carboncarbon double 'bonds per each 1000 units of Mn of the polymer, with (ii) an α,βunsaturated carboxylic compound having carboxylic acid functionality or reactive equivalent thereof; and (b) reacting the product of (a) with an amine component comprising at least one aromatic amine containing at least one NH group capable of condens ing with said carboxylic acid functionality. |
20. | The process of claim 19 wherein the α,βcarboxylic compound is reacted with the isobutylenediene polymer via a thermal reaction in the sub¬ stantial absence of added chlorine. |
21. | The process of claim 19 wherein the α,βcarboxylic compound is reacted with the isobutylenediene polymer via a radical reaction. |
22. | The process of claim 19 wherein the amine component of (b) further comprises an amine having at least two NH groups capable of condensing with said carboxylic acid functionality. |
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and isomeric variations thereof, where R1 and R2 are independently hydrogen, alkyl groups, or alkoxy groups such as methyl, methoxy, or ethoxy. In one instance, R1 and R2 are both -OCH3 and the material is known as Fast Blue RR [CAS# 6268-05-9]. In another instance, R1 is -OCH3 and R2 is -CH3, and the material is known as Fast Violet B [99-21-8]. When both R1 and R2 are ethoxy, the material is Fast Blue BB [120-00-3]. U.S. Patent 5,744,429 discloses other aromatic amine compounds, particularly aminoalkylphenothiazines. N-aromatic substituted acid amide compounds, such as those disclosed in U.S. Patent application 2003/0030033 Al, may also be used for the purposes of this inven¬ tion. Preferred aromatic amines include those in which the amine nitrogen is a substituent on an aromatic carboxylic compound, that is, the nitrogen is not sp2 hybridized within an aromatic ring. The aromatic amine will preferably have an N-H group capable of condensing with a carboxylic acid acylating agent. [0028] Certain aromatic amines are commonly used as antioxidants. Of particular importance in that regard are alkylated diphenylamines such as nonyldiphenylamine and dinonyldiphenylamine. To the extent that these mate¬ rials will condense with the carboxylic functionality of the polymer chain, they are also suitable for use within the present invention. However, it is believed that the two aromatic groups attached to the amine nitrogen may lead to steric hindrance and reduced reactivity. Thus, preferred amines are those having a primary nitrogen atom (-NH2) or a secondary nitrogen atom in which one of the hydrocarbyl substituents is a relatively short chain alkyl group, e.g., methyl. Among preferred aromatic amines are 4-phenylazoaniline, 4-amino- diphenylamine, 2-aminobenzimidazole, 3-nitroaniline, 4-(4-nitrophenyl- azo)aniline (disperse orange 3), N-(4-amino-5-methoxy-2-methyl-phenyl)- benzamide (fast violet B), N-(4-amino-2,5-dimethoxy-phenyl)-benzamide (fast blue RR), N-(4-amino-2,5-diethoxy-phenyl)-benzamide (fast blue BB), N-(4- amino-phenyl)-benzamide, and N,N-dimethylphenylenediamine. [0029] The above-described aromatic amines can be used alone or in combi¬ nation with each other. They can also be used in combination with additional, aromatic or non-aromatic, e.g., aliphatic, amines, which, in one embodiment, comprise 1 to 8 carbon atoms. These additional amines can be included for a variety of reasons. Sometimes it may be desirable to incorporate an aliphatic amine in order to assure complete reaction of the acid functionality of the polymer, in the event that some residual acid functionality may tend to react incompletely with a relatively more bulky aromatic amine. Alternatively, an aliphatic amine may replace a portion of a more costly aromatic amine, while maintaining the majority of the performance of the aromatic amine. Aliphatic monoamines include methylamine, ethylamine, propylamine and various higher amines. Diamines or polyamines can be used for this function, provided that, in general, they have only a single reactive amino group, that is, a primary or secondary, and preferably primary, group. Suitable examples of such diamines include dimethylaminopropylamine, diethylaminopropylamine, dibutylamino- propylamine, dimethylaminoethylamine, diethylaminoethylamine, dibutylami- noethylamine, l-(2-aminoethyl)piperidine, l-(2-aminoethyl)pyrrolidone, amino- ethylmorpholine, and aminopropylmorpholine. The amount of such an amine is typically a minor amount compared with the amount of the aromatic amine, that is, less than 50% of the total amine present on a weight or molar basis, although higher amounts can be used. Exemplary amounts include 10 to 70 weight percent, or 15 to 50 weight percent, or 20 to 40 weight percent. [0030] In one embodiment of the invention, the amine component of the reaction product further comprises an amine having at least two N-H groups capable of condensing with said carboxylic acid functionality (that is, two or more reactive groups). This material is referred to hereinafter as a "linking amine" as it can be employed to link together two of the polymers containing the carboxylic acid functionality. Such products exhibit even more superior soot-handling performance. The linking amine can be either an aliphatic amine or an aromatic amine; if it is an aromatic amine, it is considered to be in addi- tion to and a distinct element from the aromatic amine described above, which need have and preferably should have only one condensable or reactive NH group, in order to avoid excessive crosslinking of the polymer chains. Exam¬ ples of such linking amines include ethylene diamine, 2,4-diaminotoluene and phenylene diamine; others include propylene diamine, hexamethylene diamine, and other α,β-polyalkylenediamines. [0031] Other specific means of linkage of an aromatic amine onto the car- boxy-containing interpolymer are also contemplated as included within the scope of the invention by the expression "the reaction product of an isobutylene- diene copolymer and an amine component." For example, amine functionality can be introduced into the polymer by including an amine-containing comono- mer in the reaction mixture when the interpolymer is grafted. The amine- containing comonomer can be the reaction or condensation product of an amine with the alpha, beta-unsaturated acylating agent described above. For instance, the condensation product of maleic anhydride and an aromatic amine such as 4- aminodiphenylamine or 4-phenylazoaniline can be employed. The latter materi¬ als is known and bears the CAS number [16201-96-0]. It is believed to have the structure
4-phenylazomaleinanil O or 1-(4-pheylazo-phenyl)-pyrrole-2,5-dione (including geometric and positional isomers thereof). Similarly, the adduct with 4-aminodiphenylamine and methods of its preparation are reported in U.S. Patent Application Publication 2004/0043909; see for instance Example 1 on page 15. [0032] In another example of such an alternative route, a hydroxyamide can be esterified with the carboxy groups on the polymer chain. Exemplary hy- droxyamides can be represented by
HO-R-CO-NH-Ar and HO-CH2-CO-NH
where the Ar is an aromatic moiety of the aromatic amine (which may contain additional nitrogen or other functionality) and R is an alkylene or hydrocarby- lene linking group. Alternatively, a hydroxyacid can be first esterified with a carboxy group on the interpolymer and thereafter reacted with an aromatic amine; in either case the hydroxyacid serves as a linking group between the polymer chain and the aromatic amine. [0033] The total amount of the amine condensed onto the carboxylic acid functionality of the polymer is preferably about 1 equivalent of reactive amine functionality per equivalent of α,β-unsaturated carboxy compound on the polymer chain as described above. If more than a stoichiometric amount is used, excess amine may remain and may need to be removed from the product. If less than a stoichiometric amount is used, residual unreacted acid or anhy- dride functionality may remain in the polymer which may likewise be undesir¬ able. If a diamine is used in addition to an aromatic monoamine, the diamine can be present in an amount of 1 mole (that is, 2 equivalents) of condensable amine functionality per 5 to 6 moles of carboxy compound on the polymer chain. Thus, the diamine can be 1 mole (2 equivalents) per 4 to 5 moles of aromatic monoamine. It is desirable that any linking amine be used in an amount such that the anhydrides (or carboxy materials) on any given polymer chain react with an amine nitrogen from only one linking amine molecule, so as to minimize the likelihood of gelling of the polymer. [0034] The carboxylic derivative compositions produced by reacting the carboxylated copolymers of the invention and the amines described above are acylated amines which include amine salts, amides, imides and imidazolines as well as mixtures thereof. To prepare the carboxylic derivative compositions from the amines, one or more of the carboxylated copolymers and one or more amines can be heated, optionally in the presence of a normally liquid, substan- tially inert organic liquid solvent/diluent, at temperatures of 80°C up to the decomposition point of any of the reactants or the product, but normally at temperatures of 100°C to 300°C, provided 300°C does not exceed the decompo¬ sition point of a reactant or the product. Temperatures of 1250C to 2500C are commonly used. If more than one amine is used, the amines can be added and reacted in either order, or simultaneously. The carboxylic composition and the amine are reacted in an amount sufficient to provide from about one-half equivalent up to two moles of amine per equivalent of the carboxylic composi¬ tion. In another embodiment, the carboxylic composition is reacted with from about one-half equivalent up to one mole of amine per equivalent of the carbox- ylic composition. For the purpose of this invention, an equivalent of amine is that amount of amine corresponding to the total weight of amine divided by the total number of condensable nitrogens present having H-N< groups. Thus, octyl amine has an equivalent weight equal to its molecular weight; ethylenediamine has an equivalent weight equal to one-half its molecular weight, and amino- ethylpiperazine, with 3 nitrogen atoms but only two having at least one H-N< group, has an equivalent weight equal to one-half of its molecular weight. The Oil of Lubricating Viscosity [0035] The lubricating compositions of this invention employ an oil of lubricating viscosity, including natural or synthetic lubricating oils and mixtures thereof. Natural oils include animal oils and vegetable oils (e.g. castor oil, lard oil) as well as mineral lubricating oils such as liquid petroleum oils and solvent-treated or acid treated mineral lubricating oils of the paraffinic, naphthenic or mixed paraffinic-naphthenic types. Oils of lubricating viscosity derived from coal or shale are also useful. Synthetic lubricating oils include hydrocarbon oils and halosubstituted hydrocarbon oils such as polymerized and interpolymerized olefins and mixtures thereof, alkylbenzenes, polyphenyl, (e.g., biphenyls, terphenyls, alkylated polyphenyls), alkylated diphenyl ethers and alkylated diphenyl sulfides and the derivatives, analogs and homologues thereof. Alkylene oxide polymers and interpolymers and derivatives thereof where their terminal hydroxyl groups have been modified by esterification, etherification, etc., constitute another useful class of known synthetic lubricating oils. Another suitable class of synthetic lubricating oils comprises the esters of di- and poly- carboxylic acids and those made from C5 to C20 monocarboxylic acids and polyols and polyolethers. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids, polymeric tetrahydrofurans and the like, sili¬ con-based oils such as the polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy- siloxane oils and silicate oils. Synthetic oils also include those produced by a gas-to-liquid or Fischer-Tropsch process. [0036] ' Unrefined, refined and rerefined oils, either natural or synthetic (as well as mixtures of two or more of any of these) of the type disclosed herein- above can be used in the compositions of the present invention. Unrefined oils are those obtained directly from natural or synthetic sources without further purification treatment. Refined oils are similar to the unrefined oils except they have been further treated in one or more purification steps to improve one or more properties. Refined oils include solvent refined oils, hydrorefined oils, hydrofinished oils, hydrotreated oils, and oils obtained by hydrocracking and hydroisomerization techniques. [0037] Oils of lubricating viscosity can also be defined as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. The five base oil groups are as follows: Base Oil Category Sulfur (%) Saturates (%) Viscosity Index Group I >0.03 and/or <90 80-120 Group II <0.03 and >90 80-120 Group III <0.03 and >90 >120 Group IV All polyalphaolefins (PAOs) Group V All others not included in Groups I, II, III, or IV Groups I, II, and III are mineral oil base stocks. Group III base oils are also sometimes considered to be synthetic base oils. Other Additives [0038] The lubricating oil compositions of this invention may contain other components. The use of such additives is optional and the presence thereof in the compositions of this invention will depend on the particular use and level of performance required. Thus the other additive may be included or excluded. The compositions may comprise a metal salt, frequently a zinc salt of a dithio- phosphoric acid. Zinc salts of dithiophosphoric acids are often referred to as zinc dithiophosphates or zinc O,O'-dihydrocarbyl dithiophosphates and are sometimes referred to by the abbreviations ZDP, ZDDP, or ZDTP. One or more zinc salts of dithiophosphoric acids may be present in a minor amount to pro¬ vide additional extreme pressure, anti-wear and anti-oxidancy performance. Other metal salts of dithiophosphoric acids, such as copper, antimony, etc. salts are known and may be included in the lubricating oil compositions of this invention. [0039] Other additives that may optionally be used in the lubricating oils of this invention include detergents, dispersants, viscosity improvers, oxidation inhibiting agents (antioxidants), pour point depressing agents, extreme pressure agents, friction modifiers, anti-wear agents, color stabilizers and anti-foam agents. The above-mentioned dispersants and viscosity improvers may be used in addition to the compositions of this invention. [0040] Auxiliary extreme pressure agents and corrosion and oxidation inhibiting agents which may be included in the compositions of the invention are exemplified by chlorinated aliphatic hydrocarbons, organic sulfides and polysulfides, phosphorus esters including dihydrocarbon and trihydrocarbon phosphites, molybdenum compounds, and the like. [0041] Auxiliary viscosity improvers (also sometimes referred to as viscosity index improvers or viscosity modifiers) may be included in the compositions of this invention. Viscosity improvers are usually polymers, including polyisobute- nes, polymethacrylic acid esters, diene polymers, polyalkyl styrenes, esterified styrene-maleic anhydride copolymers, alkenylarene-conjugated diene copolymers (that is, vinylarene-conjugated polyene copolymers and hydrogenated copolymers of this type, such as hydrogenated styrene-butadiene copolymers), and polyole- fins. Multifunctional viscosity improvers, other than those of the present inven¬ tion, which also have dispersant and/or antioxidancy properties are known and may optionally be used in addition to the products of this invention. [0042] Detergents are typically overbased materials. Overbased materials, otherwise referred to as overbased or superbased salts, are generally homogene¬ ous Newtonian systems characterized by a metal content in excess of that which would be present for neutralization according to the stoichiometry of the metal and the particular acidic organic compound reacted with the metal. The over¬ based materials are prepared by reacting an acidic material (typically an inor¬ ganic acid or lower carboxylic acid, preferably carbon dioxide) with a mixture comprising an acidic organic compound, a reaction medium comprising at least one inert, organic solvent (mineral oil, naphtha, toluene, xylene, etc.) for said acidic organic material, a stoichiometric excess of a metal base, and a promoter such as a phenol or alcohol. The acidic organic material will normally have a sufficient number of carbon atoms to provide a degree of solubility in oil. The amount of excess metal is commonly expressed in terms of metal ratio. The term "metal ratio" is the ratio of the total equivalents of the metal to the equiva- lents of the acidic organic compound. A neutral metal salt has a metal ratio of one. A salt having 4.5 times as much metal as present in a normal salt will have metal excess of 3.5 equivalents, or a ratio of 4.5. [0043] Such overbased materials are well known to those skilled in the art. Patents describing techniques for making basic salts of sulfonic acids, carbox- ylic acids, phenols, phosphonic acids, and mixtures of any two or more of these include U.S. Patents 2,501,731; 2,616,905; 2,616,911; 2,616,925; 2,777,874; 3,256,186; 3,384,585; 3,365,396; 3,320,162; 3,318,809; 3,488,284; and 3,629,109. [0044] Dispersants are well known in the field of lubricants and include primarily what is known as ashless-type dispersants. Ashless type dispersants are characterized by a polar group attached to a relatively high molecular weight hydrocarbon chain. Typical ashless dispersants include N-substituted long chain alkenyl succinimides, having a variety of chemical structures including typically O O R^CH-C C-CH-R1 N-[R2-NH]X-R2-N
where each R1 is * independently an alkyl g vroup (which may bear more than one succinimide group), frequently a polyisobutyl group with a molecular weight of 500-5000 (and the corresponding dispersant is thus a polyisobutene succinim¬ ide), and R2 are alkylene groups, commonly ethylene (C2H4) groups. Such molecules are commonly derived from reaction of an alkenyl acylating agent with a polyamine, and a wide variety of linkages between the two moieties is possible beside the simple imide structure shown above, including a variety of amides and quaternary ammonium salts. Succinimide dispersants are more fully described in U.S. Patents 4,234,435 and 3,172,892. Particularly useful suc¬ cinimide dispersants are those having a N:CO ratio of greater than about 1, that is, with overall excess nitrogen functionality derived from the polyamine, compared with the carbonyl functionality derived from the succinic acid groups. Such materials may also be described as high nitrogen dispersants, containing at least 1.6% or at least 2% nitrogen in the dispersant (on an active chemical, oil- free basis) and having a relatively high total base number (TBN) of at least 30, 40, or even 50 (mg equivalent KOH per gram of sample, active chemical basis). Desirable materials are also relatively high molecular weight dispersants, having, for instance alkyl or hydrocarbyl (polymer) groups with Mn of greater than 1300. [0045] Another class of ashless dispersant is high molecular weight esters. These materials are similar to the above-described succinimides except that they may be seen as having been prepared by reaction of a hydrocarbyl acylating agent and a polyhydric aliphatic alcohol such as glycerol, pentaerythritol, or sorbitol. Such materials are described in more detail in U.S. Patent 3,381,022. [0046] Another class of ashless dispersant is Mannich bases. These are materials which are formed by the condensation of a higher molecular weight, alkyl substituted phenol, an alkylene polyamine, and an aldehyde such as formaldehyde. Such materials may have the general structure
CH2-NH-(R2NH)X-R2NHCH;
(including a variety of isomers and the like) and are described in more detail in U.S. Patent 3,634,515. [0047] Other dispersants include polymeric dispersant additives, which are generally hydrocarbon-based polymers which contain polar functionality to impart dispersancy characteristics to the polymer. [0048] Dispersants can also be post-treated by reaction with any of a variety of agents. Among these are urea, thiourea, dimercaptothiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted suc- cinic anhydrides, nitriles, epoxides, boron compounds, and phosphorus com¬ pounds. References detailing such treatment are listed in U.S. Patent 4,654,403. [0049] The above-illustrated additives may each be present in lubricating compositions at a concentration of as little as 0.001% by weight, usually 0.01% to 20% by weight. In most instances, they each contribute 0.1% to 10% by weight, more often up to 5% by weight. Additive Concentrates [0050] The various additives described herein can be added directly to the lubricant. Preferably, however, they are diluted with a concentrate-forming amount of a substantially inert, normally liquid organic diluent such as mineral oil or a synthetic oil such as a polyalphaolefin to form an additive concentrate. These concentrates usually comprise 0.1 to 80% by weight of the compositions of this invention and may contain, in addition, one or more other additives known in the art or described hereinabove. Concentrations such as 15%, 20%, 30% or 50% of the additives or higher may be employed. By a "concentrate forming amount" is generally mean an amount of oil or other solvent less than the amount present in a fully formulated lubricant, e.g., less than 85% or 80% or 70% or 60%. Additive concentrates can be prepared by mixing together the desired components, often at elevated temperatures, usually up to 150° C or 130° C or 115° C. Lubricating Oil Compositions [0051] The instant invention also relates to lubricating oil compositions containing the carboxylic compositions of the invention. The amount of poly¬ mer contained in a fully formulated lubricant is typically 0.1 to 10% by weight, alternatively 0.5 to 6% or 1 to 3% by weight. As noted hereinabove, the compo¬ sitions of this invention may be blended directly into an oil or lubricating viscosity or, more often, are incorporated into an additive concentrate contain- ing one or more other additives which in turn is blended into the oil. [0052] It is known that some of the materials described above may interact in the final formulation, so that the components of the final formulation may be different from those that are initially added. For instance, metal ions (of, e.g., a detergent) can migrate to other acidic or anionic sites of other molecules. The products formed thereby, including the products formed upon employing the composition of the present invention in its intended use, may not be susceptible of easy description. Nevertheless, all such modifications and reaction products are included within the scope of the present invention; the present invention encom¬ passes the composition prepared by admixing the components described above. EXAMPLES Example 1 [0053] Isobutylene, isoprene, hexane, and AlCl3 are charged to a IL continu¬ ous reactor. Solid AlCl3 is added to promote polymerization of the monomers. The reaction mixture is maintained at -3O0C by external cooling. Over seven hours, 7056 g isobutylene, 858 g isoprene, 11,780 mL hexanes, and 17.3 g AlCl3 are charged to the reaction vessel. [0054] Product leaving the reactor is quenched by dropping into a mixture of hexanes, methanol and water. The organic layer is washed with distilled water, dried with magnesium sulfate, filtered, concentrated in vacuo and stripped at 205°C at 133 Pa (1 mm Hg). The yield of copolymer is 2450 g. Mn (GPC vs. polyisobutylene standards) is 6900. By 1H NMR, 1 isoprene-derived monomer unit is present in 1000 molecular weight units of the polymer. •Example 2 [0055] A copolymer is prepared analogously to the polymer in example 1. Over ten hours, 10,080 g isobutylene, 915 g isoprene, 16,420 mL hexanes, and 13 g AlCl3 are charged to the reaction vessel. The yield of copolymer is 3429 g. Mn (GPC vs. polyisobutylene standards) is 8200. By 1H NMR, 1 isoprene- derived monomer unit is present in 1300 molecular weight units of the polymer. Examples 3-6 [0056] Four copolymers are prepared analogously using different catalysts and different temperatures. Example 3 Example 4 • Example 5 Example 6 Isobutylene, g 7056 3024 7056 8064 Isoprene, g 643 274 643 733 Hexane, g 7700 3300 7700 9600 Catalyst, g 7 3 7 10 Identity of catalyst EtAlCl2 EtAlCl2 AlCl3 AlCl3 Reaction temp., °C -30 -50 -50 -32 Reaction time, hr 7 3 7 8 Yield of copolymer, g 1500 587 1500 2742 Mn of copolymer 11,400 13,800 14,000 12,750 Molecular Wt. per 1500 1153 1074 1784 isoprene-derived monomer unit
Example 7 [0057]' The copolymer from example 1 (2450 g) and maleic anhydride (88 g) are heated at 203 °C for 24 hours with stirring under a blanket of N2 and are blown with N2 for 30 minutes at 14 L/hr (0.5 SCFH). The resulting hydrocar- byl-substituted acylating agent has a Total Acid Number (TAN) of 38 and 0.7 wt.% unreacted maleic anhydride. Examples 8-10 [0058] Three hydrocarbyl-substituted acylating agents are prepared accord- ing to the procedure of Example 7 using copolymer of Example 2. Example 8 Example 9 Example 10 Copolymer, g 725 2048 650 Maleic anhydride, g 16 57 29 TAN 24 29 40 Unreacted maleic anhydride, wt % 0.07 0.08 0.16
Examples 11-12 [0059] Two hydrocarbyl-substituted acylating agents are prepared according to the procedure of Example 7 using the copolymers of Examples 3-4. Example 11 Example 12 Identity of copolymer Example 3 Example 4 Copolymer, g 1600 586 Maleic anhydride, g 63 25 TAN 39 40 TAN after oil dilution (50%) 21 22 Unreacted maleic anhydride, wt% 0.19 0.2
Example 13 [0060] The copolymer from example 6 (403 g) and maleic anhydride (22 g) are heated to 160°C with stirring under a blanket of N2 14 L/hr (0.5 SCFH). T- butyl peroxide (4 g) is charged to a dropping funnel and added drop-wise over 2.5 hr. The preparation is stirred for an additional 30 min at 16O0C, and the sample is purged with N2 57 L/hr (2.0 SCFH) at 19O0C. The resulting hydrocar- byl-substituted acylating agent has a Total Acid Number (TAN) of 46 and 0.2 wt. % unreacted maleic anhydride. Example-14 [0061] A dispersant viscosity modifier is prepared by diluting 175 g of the hydrocarbyl-substituted acylating agent of Example 7 with 393 g diluent oil. Then H g 4-aminodiphenylamine is added at 110°C over 30 minutes followed by heating at 160°C for 4 hours. The product is obtained by filtration through a pad of diatomaceous earth. Yield is 548 g. Percent nitrogen is 0.29. Kinematic viscosity at 100°C = 98 (KVlOO, ASTM D445_100). Examples 15-17 [0062] Three dispersant viscosity modifiers are prepared by the method of Example 14 using the hydrocarbyl-substituted acylating agents of Examples 8- 10. Example 15 Example 16 Example 17 Acylating agent: source Example 8 Example 9 Example 10 amount, g 680 • 990 618 Oil, g 1497 2195 1390 Aminodiphenylamine, g 27 48 40 Yield 2105 3074 1963 % nitrogen 0.17 0.19 0.33 KV lOO 94 96 124 Example 18 [0063] A dispersant viscosity modifier is prepared by diluting 1026 g of acylating agent of Example 9 with 2241 g of diluent oil. To this mixture at 50°C is added 3 g of ethylenediamine dropwise over the course of two hours. The resulting mixture is warmed to HO0C and 30 g 4-aminodiphenylamine is added portion- wise over ten minutes. The resulting mixture is stirred at 110°C for one hour and then at 1600C for nine hours. The product is filtered using diatomaceous earth. Yield is 3119 g. Percent nitrogen is 0.22. KV 100 is 177. Example 19 [0064] A dispersant viscosity modifier is prepared by diluting 374 g of the acylating agent from Example 13 with 852 g of diluent oil. To this mixture at HO0C is added 28 g of 4-aminodiphenylamine over the course of 30 min. The resulting mixture is warmed to 1600C and stirred for 5 hr. The product is filtered using diatomaceous earth. Yield is 1205 g. Percent nitrogen is 0.29. KV 100 is 159. [0065] A soot screen test is performed on several of the experimental sam¬ ples prepared above. In this test, the candidate chemistry is added to an oil sample from the end of a test drain from a Mack™ T-I l engine. The sample is subjected to oscillation and the ability of the candidate to reduce the buildup of associations between molecules of soot is measured as a modulus, by a method described in SAE Paper 2001-01-1967, "Understanding Soot Mediated Oil Thickening: Rotational Rheology Techniques to Determine Viscosity and Soot Structure- in Peugot XUD-Il BTE Drain Oils," M. Parry, H. George, and J. Edgar, presented at International Spring Fuels & Lubricants Meeting & Exhibi- tion, Orlando, Florida, May 7-9, 2001. The calculated parameter is referred to as G' . The G' of the sample treated with the experimental chemistry is compared to the G' of the drain oil without the additive, the latter of which is defined as 1.00. Values of G' less than 1.00 indicate increasing effectiveness at soot dispersion. [0066] G' Table Ex. 20 Ex. 21 Ex. 22 Ex. 23 Ex. 24 Ex. 25 Dispersant Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ex. 19 ID 1% disp. 0.33 0.55 0.47 0.16 0.25 0.16 2% disp. ■ 0.17 0.34 0.31 0.09 0.11 0.04 Examples 26-28 [0067] Three lubricant formulations are prepared and are subjected to the Mack™ T-I l test. In this test a sample of lubricant is run in a Mack™ T-Il for up to 252 hours. Over time, as soot is accumulated in the oil, samples are withdrawn and their kinematic viscosity is measured at 100°C. Results are reported as viscosity increase in mm2/s (cSt). [0068] Example 26 (reference) is a baseline contains oil and a commercial composition including an olefin copolymer viscosity modifier, detergent(s), overbased calcium detergent(s), phenolic antioxidant(s), a corrosion inhibitor, and other conventional components. Example 27 (reference) is substantially the same formulation but contains 2.6% of a succinimide dispersant with a polyiso- butylene/isoprene substituent (not corrected for diluent oil; 1.17% active chemi¬ cal in the lubricant). Example 28 is substantially the same formulation but containing 3.1% of the dispersant viscosity modifier of the present invention, (as in Example 27, not corrected; providing 1.0% active chemical in the lubri¬ cant), and the amount of conventional viscosity modifier reduced by a compara¬ ble amount. [0069] The viscosity increase for each of the samples, as a function of time and soot buildup, is shown in the following table:
Example 26 (ref) Example 27 (ref) Example 28 Baseline Baseline + IOB/IP Baseline + IOB/IP dispersant dispersant/VM time, hr. Wt % Viscosity Wt % Viscosity Wt % Viscosity Soot increase, Soot increase, Soot increase, mm2/s (cSt) mm2/s (cSt) mm2/s (cSt) 0 0.16 0.00 0.21 0.00 0.15 1.92 12 0.44 0.00 0.61 0.00 0.59 1.51 24 0.67 0.00 0.80 0.00 0.80 1.41 36 0.98 0.00 1.09 0.00 1.02 1.42 48 1.35 0.02 1.53 0.08 1.32 1.40 60 1.66 0.06 1.79 0.11 1.59 1.50 72 1.95 0.30 2.11 0.15 1.92 1.60 84 2.36 0.45 2.44 0.37 2.26 1.84 96 2.75 0.72 2.79 0.55 2.55 2.02 108 3.10 1.12 3.06 0.77 2.89 2.27 120 3.47 1.64 3.46 1.11 3.37 2.72 132 3.83 2.20 3.80 1.61 3.70 2.99 144 4.17 3.13 4.17 2.15 3.99 3.45 156 4.52 4.72 4.47 2.71 4.27 4.17 168 4.84 7.82 4.78 3.54 4.59 4.61 180 5.21 16.55 5.03 5.00 4.84 5.44 192 5.69 35.66 5.43 7.54 5.17 6.33 204 6.14 53.12 5.76 17.30 5.48 7.11 216 6.21 139.66 5.92 28.92 5.88 9.88 228 6.66 6.26 43.35 6.28 14.24 240 7.09 6.54 47.21 6.53 29.43 252 7.58 6.96 71.46 6.84 50.29
[0070] The results in the table show that the baseline material exhibits a significant rise in viscosity beginning at about a 4% soot level (144 hours). The baseline + dispersant material of Example 27 exhibits a gradual increase and a significant upward break at around 5.5% soot level (192 hours). The inventive material of Example 28 also exhibits gradual increase and a significant upward break at around 6% soot level (216 hours). (The non-zero values for viscosity increase for Example 28 at low soot levels are considered to be of no signifi¬ cance and may be subtracted from the subsequent values in this table.) The results show that the materials of the present invention are effective at dispers¬ ing soot in this diesel engine test. [0071] Each of the documents referred to above is incorporated herein by reference. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reac- tion conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about." Unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, by-products, deriva¬ tives, and other such materials which are normally understood to be present in the commercial grade. However, the amount of each chemical component is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, unless otherwise indicated. It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements. As used herein, the expression "consisting essentially of" permits the inclusion of substances that do not materially affect the basic and novel characteristics of the composition under consideration.