The present invention relates to a PIB macromonomer of the formula (I) as defined below; to a copolymer comprising the PIB macromonomer of the formula (I) in polymerized form; to a lubricant comprising the copolymer; and to a method for preparing the macromonomer of the formula (I) comprising the step of reacting a PIB-alcohol of the formula (II) as defined below with a (meth)acrylic acid derivative. Combinations of preferred embodiments with other preferred embodiments are within the scope of the present invention.

Comb polymers are difficult to synthesize, e.g. using macromonomers which are difficult to incorporate. Comb polymers, such as polymethacrylate are useful for lubricants. Objects were to find improved synthesis of macromonomers and of comb polymers and improved lubricants containing the comb polymers. Further objective was to improved lubricants containing a polymer, where the lubricant has good rheological behavior, a low polymer treat rate, a high viscosity index, a good low temperature performance (e.g. in the cold crankcase simulation), a low viscosity under operating conditions (e.g. in the high temperature high shear HTHS viscosity test), a high shear stability, or a low viscosity loss after many use cycles.

The object was solved by a PIB macromonomer of the formula (I) in which R is H or methyl and PIB is a polyisobutenyl radical.

R is preferably methyl.

The phenylene residue in the formula (I) can be ortho, meta or para-substituted. Preferably, the phenylene residue in the formula (I) is para-substituted, as can be seen in the PIB macromonomer of the formula (la) in which R is H or methyl and PIB is a polyisobutenyl radical. The polyisobutenyl radical are usually polymer radicals derived from isobutene and can be understood as meaning organic radicals which are derived from linear or branched oligomers or polymers of isobutene.

The polyisobutenyl radical comprises preferably a monovalent radical by the following formulae: in which the value p+2 corresponds to the degree of polymerization and indicates the number of isobutene units in the polyisobutene radical and ^* signifies the linkage to formula (I) or (la).

The degree of polymerization p+2 is typically in the range from 5 to100, in particular in the range from 8 to 80 and specifically in the range from 15 to 65.

The polyisobutenyl radical can also comprise a divalent radical PIB’ of the the following formulae: in which the value p+2 corresponds to the degree of polymerization and indicates the number of isobutene units in the polyisobutene radical and ^* signifies the linkage to formula (I) or (la).

The polyisobutenyl radical can be a mixture of both monovalent radical and divalend radical PIB’.

The polyisobutenyl radical can comprise, polymerized therein, up to 20% by weight, preferably not more then 10% by weight, of C2-Ci2-olefins different from isobutene, such as 1 -butene, 2- butene, 2-methyl-1 -butene, 2-methylpentene-1 , 2-methylhexene-1 , 2-ethylpentene-1 , 2- ethylhexene-1 , 2-propylheptene-1.

The polyisobutenyl radical may have molecular weight of 300 to 10000 g/mol, preferably of 400 to 5000 g/mol, and in particular of 800 to 2500 g/mol.

The invention also relates to a method for preparing the macromonomer of the formula (I) comprising the step of reacting a PIB alcohol of the formula (II) in which PIB is a polyisobutenyl radical, with a (meth)acrylic acid derivative, which is preferably methacrylic anhydride.

Suitable (meth)acrylic acid derivatives are (meth)acrylic anhydride or C1-22 alkyl (meth)acrylates. The (meth)acrylic acid derivative is preferably (meth)acrylic anhydride, such as methacrylic anhydride.

The reacting of the PIB-alcohol with the (meth)acrylic acid derivative can be made without or preferably with an organic solvent. Examples of suitable organic solvents are aromatic hydrocarbons, e.g. benzene, toluene, xylenes, mesitylene, naphthalene, tert-butylbenzene, and mixtures thereof, (cyclo)aliphatic hydrocarbons, e.g. hexane, heptane, octane, isooctane, cyclohexane, cycloheptane, cyclooctane, tetralin, and mixtures thereof, halogenated hydrocarbons such as dichloromethane, 1 ,1-dichloroethane, 1 ,2-dichloroethane, 1 ,1- dichloroethene, 1 ,2-dichloroethene, chlorobenzene, dichlorobenzene, chlorotoluene and mixtures thereof, and also mixtures of the aforementioned aromatic and (cyclo)aliphatic hydrocarbons and mixtures of the aforementioned hydrocarbons with halogenated hydrocarbons.

The reacting of the PIB-alcohol with the (meth)acrylic acid derivative can be made at temperatures of 0 to 150 °C, preferably 15 to 110 °C, and in particular 40 to 95 °C.

The reacting of the PIB-alcohol with the (meth)acrylic acid derivative can be made in the presence of an antioxidant, such as butylhydroxytoluol.

The PIB-alcohol of the formula (II) is known, e.g. from US 4,354,950, and can be prepared from polyisobutenesuccinic anhydride (also called PIBSA) and an aminophenol, such as ortho-, meta- or para-aminophenol (preferably para-aminophenol).

Polyisobutenesuccinic anhydride is understood here and below as meaning the internal anhydrides of polyisobutenesuccinic acid, i.e. substances in which the two carboxyl groups of the succinic acid radical form a 1-oxolane-2,5-dion-2-yl radical. Polyisobutenesuccinic anhydrides of this type can be described in particular by the following formulae (III) and (IV) in which PIB and PIB' have the meanings given above. Preferably, the PIBSA, based on the total weight of the anhydride, to at least 50% by weight, in particular to at least 70% by weight, the anhydride of formula (III). Preferably, the PIBSA comprises, based on the total weight of the anhydride, less than 30% by weight, in particular less than 20% by weight, of anhydride of the formula (IV). As a consequence of the preparation, the PIBSA can comprise polyisobutene. The fraction of the polyisobutene can constitute up to 50% by weight, but preferably not more than 40% by weight or not more than 30% by weight, based on the total amount of PIBSA + polyisobutene.

The relative fraction of compounds of the formula (III) and (IV) in the PIBSA usually corresponds to the saponification number of the PIBSA, determined analogously to DIN 53401 , and often depends on the molecular weight. Typically the PIBSA has a saponification number SN in the range from 20 to 240 mg KOH/g and preferably in the range from 40 to 220 mg KOH/g, determined in accordance with DIN 53401 .

The PIBSA is commercially available, e.g. from BASF SE. A nonlimiting example of a particularly suitable PIBSA is Glissopal® SA F from BASF, prepared from HFt-PIB (Mn = 1000) having a bismaleation level of 15% and a hydrolysis number of 90 mg KOH/g.

Preference is given to PIBSA which are obtainable by reacting olefinically unsaturated polyisobutenes with maleic anhydride. Particular preference is given to products which are obtained by reacting highly reactive polyisobutenes with maleic anhydride. Highly reactive polyisobutenes are understood as meaning polyisobutenes with at least 50 mol%, often with at least 60 mol% and in particular with at least 80 mol%, based on the total number of polyisobutene macromolecules, of terminally arranged double bonds. The terminally arranged double bonds may either be vinyl double bonds [-CH=C(CH ₃ )2] (D-olefin) or vinylidene double bonds [-CH-C(=CH ₂ )-CH ₃ ] (D-olefin). Preferred highly reactive polyisobutenes have predominantly vinylidene double bonds. Highly reactive polyisobutenes are commercially available, e.g. the Glissopal grades from BASF SE, thus e.g. Glissopal® 1000 and Glissopal® 1300, Glissopal® 2300. The preparation of PIBSA from polyisobutene and maleic anhydride often leads to a mixture of PIBSA and bismaleated PIBSA (BM PIBSA, please see scheme 1 below), which is generally not purified but processed further as it is. The ratio of the two components to one another can be reported as the bismaleation level (BML). The BML can be determined as described in US 5,883,196. Especially preferred is PIBSA having a bismaleation level of up to 30%, preferably up to 25% and more preferably up to 20%. In general, the bismaleation level is at least 2%, preferably at least 5% and more preferably at least 10%.

Scheme 1

The invention further relates to a copolymer comprising the PIB macromonomer of the formula (I) in polymerized form.

The copolymer may comprise at least 0.1 , 0.5, 1, 3, 5, 10, or 20 wt% of the PIB macromonomer. The copolymer may comprise up to 100, 90, 80, 70, 60 or 50 wt% of the PIB macromonomer. The copolymer may comprise 1 -90 wt%, or 3-70 wt% or 5-50 wt% of the PIB macromonomer.

The copolymer may consist only of the PIB macromonomer or it may comprise an alkyl (meth)acrylate selected from C1-22 alkyl (meth)acrylate in polymerized form. Mixtures of alkyl (meth)acrylates are also possible.

Suitable alkyl (meth)acrylate are methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert- butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, 2-propyl heptyl, nonyl, decyl, stearyl, lauryl, octadecyl, heptadecyl, nonadecyl, eicosyl, henicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl, nonacosyl, triacontyl, behenyl (meth)acrylate. Preferred alkyl (meth)acrylates are methyl, n-butyl, 2-ethylhexyl, lauryl and stearyl, or mixtures of these monomers.

Preferably, the alkyl (meth)acrylate comprises methyl (meth)acrylate and optionally a C2-22 alkyl (meth)acrylate (preferably a C4-18 alkyl (meth)acrylate). In another preferred form, the alkyl (meth)acrylate comprises methyl (meth)acrylate and a C2-22 alkyl (meth)acrylate (preferably a C4-18 alkyl (meth)acrylate).

The copolymer may comprise at least 1 , 5, 10, 20, 30, 40, 50, 60, 70, 80 or 90 wt% of the alkyl (meth)acrylates.

In another form the copolymer may comprise at least 1 , 5, 10, 20, 30, 40, 50, 60, 70, 80 or 90 wt% of the alkyl (meth)acrylates where the alkyl (meth)acrylate comprises methyl (meth)acrylate and a C2-22 alkyl (meth)acrylate (preferably a C4-18 alkyl (meth)acrylate).

The copolymer may comprise up to 99, 90, 80, 70, 60, 50, 40, 30, 20 or 10 wt% of alkyl (meth)acrylates.

In another form the copolymer may comprise up to 99, 90, 80, 70, 60, 50, 40, 30, 20 or 10 wt% of alkyl (meth)acrylates where the alkyl (meth)acrylate comprises methyl (meth)acrylate and a C2-22 alkyl (meth)acrylate (preferably a C4-18 alkyl (meth)acrylate).

The copolymer may comprise 1 -90 wt%, or 3-70 wt% or 5-50 wt% of the alkyl (meth)acrylates.

In another form the copolymer may comprise 1 -90 mol%, or 3-70 mol% or 5-50 mol% of the alkyl (meth)acrylate where the alkyl (meth)acrylate comprises methyl (meth)acrylate and a C2-22 alkyl (meth)acrylate (preferably a C4-18 alkyl (meth)acrylate).

The copolymer may comprise 5-50 wt% PIB macromonomer, 0-50 wt% of methyl (meth)acrylate and 0-70 wt% C2-22 alkyl (meth)acrylate; preferably 10-35 wt% PIB macromonomer, 20-40 wt% methyl (meth)acrylate, and 25-70 wt% C2-22 alkyl (meth)acrylate; and in particular 10-20 wt% PIB macromonomer, 30-40 wt% methyl(meth)acrylate, and 40-60 wt% C2-22 alkyl (meth)acrylate.

As further comonomers, up to 50 percent by weight, preferably up to 20 percent by weight, of the following monomers, which are listed by way of example, can be employed:

- hydroxyl-, epoxy- or amino-functional (meth)acrylates

- vinylaromatic compounds, such as styrene, alpha-methylstyrene, vinyltoluene or p-(tert- butyl) styrene;

- acrylic and methacrylic acid; - acrylamide and methacrylamide;

- maleic acid and the imides and C1 -C10 -alkyl esters thereof;

- fumaric acid and the imides and C1 -C10 -alkyl esters thereof;

- itaconic acid and the imides and C1 -C10 -alkyl esters thereof; acrylonitrile and methacrylonitrile.

The copolymers may have a weight average molecular weight ranging from about 10,000 to about 800,000. Typically, the weight average may range from about 20,000 to about 500,000. The molecular weight is determined by GPC using polystyrene standards (DIN 55672-1).

The copolymer can be prepared by conventional free-radical polymerization, such as bulk polymerization or solution polymerization, where the latter is preferred.

In the solution polymerization the reaction mixture may comprises a diluent, the monomers, a polymerization initiator and optionally a chain transfer agent and optionally a crosslinker. The diluent may be any inert hydrocarbon. The concentration of total monomers may range from about 30 to 100%. As used herein, "total monomer charge" means the combined amount of all monomers in the initial reaction mixture.

Suitable polymerization initiators include initiators which disassociate upon heating to yield a free radical, e.g., peroxide compounds such as benzoyl peroxide, t-butyl perbenzoate, t-butyl peroctoate and cumene hydroperoxide; and azo compounds such as azoisobutyronitrile and 2,2'-azobis (2-methylbutanenitrile). The mixture includes from about 0.001 wt percent to about 5.0 wt percent initiator relative to the total monomer mixture. For example, 0.02 weight percent to about 4.0 weight percent, 0.02 weight percent to about 3.5 weight percent are envisioned. Typically, about 0.02 weight percent to about 2.0 weight percent are used.

Suitable chain transfer agents include mercaptanes and alcohols. For example, tridecyl mercap- tane, dodecyl mercaptane and ethyl mercaptane, but also bifunctional mercaptanes, such hexanedithiol may be used as chain transfer agents. The selection of the amount of chain transfer agent to be used is based on the desired molecular weight of the polymer being synthesized. The chain transfer agent is often added to the reaction mixture or monomer feed in an amount of 0.001 to 3 weight percent relative to the monomer mixture.

All components may be charged to a reaction vessel that is equipped with a stirrer, a thermo meter and a reflux condenser and heated with stirring under a nitrogen blanket to a temperature from about 50 degrees centigrade to about 125 degrees centigrade for a period of about 0.5 hours to about 15 hours to carry out the polymerization reaction. The reaction may be carried out in the way that only parts of the components are charged to the reaction vessel and the rest is fed continuously.

The invention further relates to a lubricant comprising the copolymer.

Preferably, the lubricant further comprising a base oil.

The lubricant usually comprises

- a base oil selected from mineral oils, polyalphaolefins, polymerized and interpolymerized olefins, alkyl naphthalenes, alkylene oxide polymers, silicone oils, phosphate ester and carboxylic acid ester; and/or

- a lubricant additive.

In one form the lubricant further comprises a base oil selected from mineral oils, polyalpha olefins, polymerized and interpolymerized olefins, alkyl naphthalenes, alkylene oxide polymers, silicone oils, phosphate ester and carboxylic acid ester. In another form the lubricant usually further comprises a lubricant additive.

In one form the lubribant may comprise at least 10 wt%, preferably at least 30 wt% and in particular at least 60 wt% of the copolymer. In another form the lubricant may comprise 10 - 99 wt%, preferably 30 - 95 wt% and in particular at least 60 - 95 wt% of the copolymer. In another form the lubricant may comprise 1 - 90 wt%, preferably 5 - 50 wt% and in particular 20 - 50 wt% of the base oil.

In another form the lubricant may comprise at least 0.1 wt%, preferably at least 0.5 wt% and in particular at least 1 wt% of the copolymer. In another form the lubricant may comprise 0.1 - 20 wt%, preferably 0.1 - 150 wt% and in particular at least 0.1 - 10 wt% of the copolymer. In another form the lubricant may comprise 30 - 99.9 wt%, preferably 50 - 99 wt% and in particular 70 - 95 wt% of the base oil.

The lubricant may comprise up to 20 wt%, preferably up to 15 wt% and in particular up to 10 wt% of the lubricant additive.

In another form the lubricant may comprise 0.1 - 20 wt%, preferably 0.1 - 15 wt% and in particular at least 0.1 - 10 wt% of the lubricant additive.

Lubricants usually refers to composition which are capable of reducing friction between surfaces (preferably metal surfaces), such as surfaces of mechanical devices. A mechanical device may be a mechanism consisting of a device that works on mechanical principles. Suitable mechanical device are bearings, gears, joints and guidances. The mechanical device may be operated at temperatures in the range of -30 C to 80 ° C.

Lubricants are usually specifically formulated for virtually every type of machine and manufacturing process. The type and concentration of base oils and/or lubricant additives used for these lubricants may be selected based on the requirements of the machinery or process being lubricated, the quality required by the builders and the users of the machinery, and the government regulation. Typically, each lubricant has a unique set of performance requirements. In addition to proper lubrication of the machine or process, these requirements may include maintenance of the quality of the lubricant itself, as well as the effect of the lubricant’s use and disposal on energy use, the quality of the environment, and on the health of the user.

Typical lubricants are automotive lubricants (e.g. gasoline engine oils, diesel engine oils, gas engine oils, gas turbine oils, automatic transmission fluids, gear oils) and industrial lubricants (e.g. industrial gear oils, pneumatic tool lubricating oil, high temperature oil, gas compressor oil, hydraulic fluids, metalworking fluids).

Examples for lubricants are axel lubrication, medium and heavy duty engine oils, industrial engine oils, marine engine oils, automotive engine oils, crankshaft oils, compressor oils, refrigerator oils, hydrocarbon compressor oils, very low-temperature lubricating oils and fats, high temperature lubricating oils and fats, wire rope lubricants, textile machine oils, refrigerator oils, aviation and aerospace lubricants, aviation turbine oils, transmission oils, gas turbine oils, spindle oils, spin oils, traction fluids, transmission oils, plastic transmission oils, passenger car transmission oils, truck transmission oils, industrial transmission oils, industrial gear oils, insulating oils, instrument oils, brake fluids, transmission liquids, shock absorber oils, heat distribution medium oils, transformer oils, fats, chain oils, minimum quantity lubricants for metalworking operations, oil to the warm and cold working, oil for water-based metalworking liquids, oil for neat oil metalworking fluids, oil for semi-synthetic metalworking fluids, oil for synthetic metalworking fluids, drilling detergents for the soil exploration, hydraulic oils, in biodegradable lubricants or lubricating greases or waxes, chain saw oils, release agents, molding fluids, gun, pistol and rifle lubricants or watch lubricants and food grade approved lubricants.

The lubricant has usually may have a kinematic viscosity at 40°C of at least 10, 50, 100, 150, 200, 300, 400, 500, 600, 900, 1400, or 2000 mm ² /s. In another form the lubricant has usually may have a kinematic viscosity at 40°C from 200 to 30 000 mm ² /s (cSt), preferably from 500 to 10 000 mm ² /s, and in particular from 1000 to 5000 mm ² /s. The lubricant has usually may have a kinematic viscosity at 100°C of at least 2, 3, 5, 10, 20, 30, 40, or 50 mm ² /s. In another form the lubricant may have a kinematic viscosity at 100°C from 10 to 5000 mm ² /s (cSt), preferably from 30 to 3000 mm ² /s, and in particular from 50 to 2000 mm ² /s

The lubricant may have a viscosity index of at least 50, 75, 100, 120, 140, 150, 160, 170, 180, 190 or 200.

The lubricant is usually a lubricating liquid, lubricating oil or lubricating grease.

The base oil may selected from the group consisting of mineral oils (Group I, II or III oils), polyalphaolefins (Group IV oils), polymerized and interpolymerized olefins, alkyl naphthalenes, alkylene oxide polymers, silicone oils, phosphate esters and carboxylic acid esters (Group V oils). Preferably, the base oil is selected from Group I, Group II, Group III base oils according to the definition of the API, or mixtures thereof. Definitions for the base oils are the same as those found in the American Petroleum Institute (API): a) Group I base oils contain less than 90 percent saturates (ASTM D 2007) and/or greater than 0.03 percent sulfur (ASTM D 2622) and have a viscosity index (ASTM D 2270) greater than or equal to 80 and less than 120. b) Group II base oils contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have a viscosity index greater than or equal to 80 and less than 120. c) Group III base oils contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have a viscosity index greater than or equal to 120. d) Group IV base oils contain polyalphaolefins. Polyalphaolefins (PAO) include known PAO materials which typically comprise relatively low molecular weight hydrogenated polymers or oligomers of alphaolefins which include but are not limited to C2 to about C32 alphaole- fins with the C8 to about C16 alphaolefins, such as 1 -octene, 1 -decene, 1-dodecene and the like being preferred. The preferred polyalphaolefins are poly- 1-octene, poly-1 -decene, and poly-1 -dode-cene. e) Group V base oils contain any base oils not described by Groups I to IV. Examples of Group V base oils include alkyl naphthalenes, alkylene oxide polymers, silicone oils, and phosphate esters.

Synthetic base oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as pol ymerized and interpolymerized olefins (e.g., polypropylenes, propylene-isobutylene copolymers, chlorinated polybutylenes, poly(1 -hexenes), poly(l -octenes), poly(l-decenes)); alkylbenzenes (e.g., dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di(2-ethylhexyl)benzenes); poly- phenyls (e.g., biphenyls, terphenyls, alkylated polyphenols); and alkylated diphenyl ethers and alkylated diphenyl sulfides and derivative, analogs and homologs thereof.

Alkylene oxide polymers and interpolymers and derivatives thereof where the terminal hydroxyl groups have been modified by esterification, etherification, etc., constitute another class of known synthetic base oils. These are exemplified by polyoxyalkylene polymers prepared by polymeriza-tion of ethylene oxide or propylene oxide, and the alkyl and aryl ethers of polyoxyalkylene poly-mers (e.g., methyl-polyiso-propylene glycol ether having a molecular weight of 1000 or diphenyl ether of polyethylene glycol having a molecular weight of 1000 to 1500); and mono- and polycar-boxylic esters thereof, for example, the acetic acid esters, mixed C3-C8 fatty acid esters and C13 oxo acid diester of tetraethylene glycol.

Silicon-based oils such as the polyalkyl-, polyaryl-, polyalkoxy- or polyaryloxysilicone oils and sili-cate oils comprise another useful class of synthetic base oils; such base oils include tetraethyl silicate, tetraisopropyl silicate, tetra-(2- ethylhexyl)silicate, tetra-(4-methyl-2-ethylhe- xyl) silicate, tetra-(p-tert-butyl-phenyl) silicate, hexa-(4-methyl-2-ethylhexyl)disiloxane, poly(methyl) siloxanes and poly(methylphenyl)siloxanes. Other synthetic base oils include liquid esters of phosphorous-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decylphosphonic acid) and polymeric tetrahydrofurans.

Suitable lubricant additives may be selected from viscosity index improvers, polymeric thickeners, antioxidants, corrosion inhibitors, detergents, dispersants, anti-foam agents, dyes, wear protection additives, extreme pressure additives (EP additives), anti-wear additives (AW additives), friction modifiers, metal deactivators, pour point depressants.

The viscosity index improvers include high molecular weight polymers that increase the relative viscosity of an oil at high temperatures more than they do at low temperatures. Viscosity index improvers include polyacrylates, polymethacrylates, alkylmethacrylates, vinylpyrrolidone/me-thacrylate copolymers, poly vinylpyrrolidones, polybutenes, olefin copolymers such as an ethylene-propylene copolymer or a styrene-butadiene copolymer or polyalkene such as PIB, styrene/acrylate copolymers and polyethers, and combinations thereof. The most common VI improvers are methacrylate polymers and copolymers, acrylate polymers, olefin polymers and copolymers, and styrenebutadiene copolymers. Other examples of the viscosity index improver include polymethacrylate, polyisobutylene, alpha-olefin polymers, alpha-olefin copolymers (e.g., an ethylenepropylene copolymer), polyalkylstyrene, phenol condensates, naphthalene condensates, a styrenebutadiene copolymer and the like. Of these, polymethacrylate having a number average molecular weight of 10000 to 300000, and alpha- olefin polymers or alpha-olefin copolymers having a number average molecular weight of 1000 to 30000, particularly ethylene- alpha-olefin copolymers having a number average molecular weight of 1000 to 10000 are preferred. The viscosity index increasing agents can be added and used individually or in the form of mixtures, conveniently in an amount within the range of from ³ 0.05 to < 20.0 % by weight, in relation to the weight of the base stock.

Suitable (polymeric) thickeners include, but are not limited to, polyisobutenes (PIB), oligomeric co-polymers (OCPs), polymethacrylates (PMAs), copolymers of styrene and butadiene, or high viscosity esters (complex esters).

Antioxidants include phenolic antioxidants such as hindered phenolic antioxidants or non- phenolic oxidation inhibitors.

Useful phenolic antioxidants include hindered phenols. These phenolic antioxidants may be ashless (metal-free) phenolic compounds or neutral or basic metal salts of certain phenolic compounds. Typical phenolic antioxidant compounds are the hindered phenolics which are the ones which contain a sterically hindered hydroxyl group, and these include those derivatives of dihydroxy aryl compounds in which the hydroxyl groups are in the o- or p-position to each other. Typical phenolic antioxidants include the hindered phenols substituted with alkyl groups having 6 carbon atoms or more and the alkylene coupled derivatives of these hindered phenols. Examples of phenolic materials of this type 2-t-butyl-4-heptyl phenol; 2-t-butyl-4-octyl phenol; 2- t-butyl-4-dodecyl phenol; 2,6-di-tbutyl-4-heptyl phenol; 2,6-di-t-butyl-4-dodecyl phenol; 2-methyl- 6-t-butyl-4-heptyl phenol; and 2-methyl-6-t-butyl-4-dodecyl phenol. Other useful hindered mono- phenolic antioxidants may include for example hindered 2,6-di-alkyl phenolic propionic ester derivatives. Bis-phenolic antioxidants may also be used in combination with the present invention. Examples of ortho-coupled phenols include: 2,2'-bis(4-heptyl-6-t-butyl-phenol); 2,2'- bis(4- octyl-6-t-butyl-phenol); and 2,2'-bis(4-dodecyl-6-t-butyl-phenol). Para-coupled bisphenols include for example 4,4'-bis(2,6-di-t-butyl phenol) and 4,4' methylene-bis(2,6-di-t-butyl phenol).

Non-phenolic oxidation inhibitors which may be used include aromatic amine antioxidants and these may be used either as such or in combination with phenolics. Typical examples of non- phenolic antioxidants include: alkylated and non-alkylated aromatic amines such as aromatic monoamines of the formula R ⁸ R ⁹ R ¹⁰ N, where R ⁸ is an aliphatic, aromatic or substituted aromatic group, R ⁹ is an aromatic or a substituted aromatic group, and R ¹⁰ is H, alkyl, aryl or R ¹¹ S(0) _x R ¹² , where R ¹¹ is an alkylene, alkenylene, or aralkylene group, R ¹² is a higher alkyl group, or an alkenyl, aryl, or alkaryl group, and x is 0, 1 or 2. The aliphatic group R ⁸ may contain from 1 to about 20 carbon atoms, and preferably contains from about 6 to 12 carbon atoms. The aliphatic group is a saturated aliphatic group. Preferably, both R ⁸ and R ⁹ are aromatic or substituted aromatic groups, and the aromatic group may be a fused ring aromatic group such as naphthyl. Aromatic groups R ⁸ and R ⁹ may be joined together with other groups such as S.

Typical aromatic amines antioxidants have alkyl substituent groups of at least about 6 carbon atoms. Examples of aliphatic groups include hexyl, heptyl, octyl, nonyl, and decyl. Generally, the aliphatic groups will not contain more than about 14 carbon atoms. The general types of amine antioxidants useful in the present compositions include diphenylamines, phenyl naphthylamines, phenothiazines, imidodibenzyls and diphenyl phenylene diamines. Mixtures of two or more aromatic amines are also useful. Polymeric amine antioxidants can also be used. Particular examples of aromatic amine antioxidants useful in the present invention include: r,r'-dioctyldiphenylamine; t-octylphenyl-alpha naphthylamine; phenyl-alphanaphthylamine; and p-octylphenyl-alphanaphthylamine. Sulfurized alkyl phenols and alkali or alkaline earth metal salts thereof also are useful antioxidants.

Corrosion inhibitors may include various oxygen-, nitrogen-, sulfur-, and phosphorus- containing materials, and may include metal-containing compounds (salts, organometallics, etc.) and nonmetal-containing or ashless materials. Corrosion inhibitors may include, but are not limited to, additive types such as, for example, hydrocarbyl-, aryl-, alkyl-, arylalkyl-, and alkylaryl versions of detergents (neutral, overbased), sulfonates, phenates, salicylates, alcoholates, carboxylates, salixarates, phosphites, phosphates, thiophosphates, amines, amine salts, amine phosphoric acid salts, amine sulfonic acid salts, alkoxylated amines, etheramines, polyether-amines, amides, imides, azoles, diazoles, triazoles, benzotriazoles, benzothiadoles, mercapto-benzothiazoles, tolyltriazoles (TTZ-type), heterocyclic amines, heterocyclic sulfides, thiazoles, thiadiazoles, mercaptothiadiazoles, dimercaptothiadiazoles (DMTD-type), imidazoles, benzimidazoles, dithiobenzimidazoles, imidazolines, oxazolines, Mannich reactions products, glycidyl ethers, anhydrides, carbamates, thiocarbamates, dithiocarbamates, polyglycols, etc., or mixtures thereof.

Detergents include cleaning agents that adhere to dirt particles, preventing them from attaching to critical surfaces. Detergents may also adhere to the metal surface itself to keep it clean and prevent corrosion from occurring. Detergents include calcium alkylsalicylates, calcium alkylphe- nates and calcium alkarylsulfonates with alternate metal ions used such as magnesium, barium, or sodium. Examples of the cleaning and dispersing agents which can be used include metal- based detergents such as the neutral and basic alkaline earth metal sulphonates, alkaline earth metal phenates and alkaline earth metal salicylates alkenylsuccinimide and alkenylsuccinimide esters and their borohydrides, phenates, salienius complex detergents and ashless dispersing agents which have been modified with sulphur compounds. These agents can be added and used individually or in the form of mixtures, conveniently in an amount within the range of from ³ 0.01 to < 1.0 % by weight in relation to the weight of the base stock; these can also be high total base number (TBN), low TBN, or mixtures of high/low TBN.

Dispersants are lubricant additives that help to prevent sludge, varnish and other deposits from forming on critical surfaces. The dispersant may be a succinimide dispersant (for example N-substituted long chain alkenyl succinimides), a Mannich dispersant, an ester-containing dispersant, a condensation product of a fatty hydrocarbyl monocarboxylic acylating agent with an amine or ammonia, an alkyl amino phenol dispersant, a hydrocarbyl-amine dispersant, a polyether dispersant or a polyetheramine dispersant. In one embodiment, the succinimide dispersant includes a polyisobutylene-substituted succinimide, wherein the polyisobutylene from which the dispersant is derived may have a number average molecular weight of about 400 to about 5000, or of about 950 to about 1600. In one embodiment, the dispersant includes a borated dispersant. Typically, the borated dispersant includes a succinimide dispersant including a polyisobutylene succinimide, wherein the polyisobutylene from which the dispersant is derived may have a number average molecular weight of about 400 to about 5000. Borated dispersants are described in more detail above within the extreme pressure agent description.

Anti-foam agents may be selected from silicones, polyacrylates, and the like. The amount of anti-foam agent in the lubricant compositions described herein may range from ³ 0.001 wt.-% to< 0.1 wt.-% based on the total weight of the formulation. As a further example, an anti-foam agent may be present in an amount from about 0.004 wt.-% to about 0.008 wt.-%.

Suitable extreme pressure agent is a sulfurcontaining compound. In one embodiment, the sulfur-containing compound may be a sulfurised olefin, a polysulfide, or mixtures thereof. Examples of the sulfurised olefin include a sulfurised olefin derived from propylene, iso butylene, pentene; an organic sulfide and/or polysulfide including benzyldisulfide; bis- (chlorobenzyl) disulfide; dibutyl tetrasulfide; di-tertiary butyl polysulfide; and sulfurised methyl ester of oleic acid, a sulfurised alkylphenol, a sulfurised dipentene, a sulfurised terpene, a sulfurised Diels-Alder adduct, an alkyl sulphenyl N'N dialkyl dithiocarbamates; or mixtures thereof. In one embodiment, the sulfurised olefin includes a sulfurised olefin derived from propylene, isobutylene, pentene or mixtures thereof. In one embodiment the extreme pressure additive sulfur-containing compound includes a dimercaptothiadiazole or derivative, or mixtures thereof. Examples of the dimercaptothiadiazole include compounds such as 2,5-dimercapto- 1 ,3,4-thiadiazole or a hydrocarbyl-substituted 2,5-dimercapto-1 ,3,4-thiadiazole, or oligomers thereof. The oligomers of hydrocarbyl-substituted 2, 5-dimercapto-1 ,3,4-thiadiazole typically form by forming a sulfur-sulfur bond between 2,5-dimercapto-1 ,3,4-thiadiazole units to form derivatives or oligomers of two or more of said thiadiazole units. Suitable 2, 5-dimercapto-1 ,3,4- thiadiazole derived compounds include for example 2, 5-bis(tert-nonyldithio)-1 ,3,4-thiadiazole or 2-tert-nonyldithio-5-mercapto-1 ,3,4-thiadiazole. The number of carbon atoms on the hydrocar- byl substituents of the hydrocarbyl-substituted 2,5-dimercapto-1 ,3,4-thiadiazole typically include 1 to 30, or 2 to 20, or 3 to 16. Extreme pressure additives include compounds containing boron and/or sulfur and/or phosphorus. The extreme pressure agent may be present in the lubricant compositions at 0 wt.-% to about 20 wt.-%, or at about 0.05 wt.-% to about 10.0 wt.-%, or at about 0.1 wt.-% to about 8 wt.-% of the lubricant composition.

Examples of anti-wear additives include organo borates, organo phosphites such as didodecyl phosphite, organic sulfur-containing compounds such as sulfurized sperm oil or sulfurized terpenes, zinc dialkyl dithiophosphates, zinc diaryl dithiophosphates, phosphosulfurized hydrocarbons and any combinations thereof.

Friction modifiers may include metal-containing compounds or materials as well as ashless compounds or materials, or mixtures thereof. Metal-containing friction modifiers include metal salts or metalligand complexes where the metals may include alkali, alkaline earth, or transition group metals. Such metal-containing friction modifiers may also have lowash characteristics. Transition metals may include Mo, Sb, Sn, Fe, Cu, Zn, and others. Ligands may include hydrocarbyl derivative of alcohols, polyols, glycerols, partial ester glycerols, thiols, carboxy- lates, carbamates, thiocarbamates, dithiocarbamates, phosphates, thiophosphates, dithiophosphates, amides, imides, amines, thiazoles, thiadiazoles, dithiazoles, diazoles, triazoles, and other polar molecular functional groups containing effective amounts of O, N, S, or P, individually or in combination. In particular, Mo-containing compounds can be particularly effective such as for example Mo-dithiocarbamates, Mo(DTC), Mo-dithiophosphates, Mo(DTP), Mo-amines, Mo (Am), Mo-alcoholates, Mo alcohol-amides, and the like.

Ashless friction modifiers may also include lubricant materials that contain effective amounts of polar groups, for example, hydroxyl-containing hydrocarbyl base oils, glycerides, partial glycerides, glyceride derivatives, and the like. Polar groups in friction modifiers may include hydrocarbyl groups containing effective amounts of O, N, S, or P, individually or in combination. Other friction modifiers that may be particularly effective include, for example, salts (both ash- containing and ashless derivatives) of fatty acids, fatty alcohols, fatty amides, fatty esters, hydroxyl-containing carboxylates, and comparable synthetic long-chain hydrocarbyl acids, alcohols, amides, esters, hydroxy carboxylates, and the like. In some instances, fatty organic acids, fatty amines, and sulfurized fatty acids may be used as suitable friction modifiers. Examples of friction modifiers include fatty acid esters and amides, organo molybdenum compounds, molybdenum dialkylthiocarbamates and molybdenum dialkyl dithiophosphates. Suitable metal deactivators include benzotriazoles and derivatives thereof, for example 4- or 5-alkylbenzotriazoles (e.g. triazole) and derivatives thereof, 4,5,6,7-tetrahydrobenzotriazole and 5,5'-methylenebisbenzotriazole; Mannich bases of benzotriazole or triazole, e.g. 1-[bis(2-ethyl- hexyl) aminomethyl) triazole and 1-[bis(2- ethylhexyl) aminomethyl)benzotriazole; and alkoxyal- kylbenzotriazoles such as 1-(nonyloxymethyl)benzotriazole, 1-(1-butoxyethyl) benzotriazole and 1-(1-cyclohexyloxybutyl) triazole, and combinations thereof. Additional non-limiting examples of the one or more metal deactivators include 1 ,2,4-triazoles and derivatives thereof, for example 3-alkyl(or aryl)-1 , 2,4-triazoles, and Mannich bases of 1 ,2,4-triazoles, such as 1-[bis(2- ethylhexyl) aminomethyl -1 , 2,4-triazole; alkoxyalky1-1 , 2,4-triazoles such as 1-(1-bu-toxyethyl)- 1 , 2,4-triazole; and acylated 3-amino-1 , 2,4-triazoles, imidazole derivatives, for example 4,4'- methylenebis(2-undecyl-5-methylimidazole) and bis[(N-methyl)imidazol-2-yl]car-binol octyl ether, and combinations thereof. Further non-limiting examples of the one or more metal deactivators include sulfur-containing heterocyclic compounds, for example 2-mercapto- benzothiazole, 2,5-dimercapto-1 , 3,4-thia-diazole and derivatives thereof; and 3,5-bis[di(2- ethylhexyl) aminomethyl]-1 , 3,4-thiadiazolin-2-one, and combinations thereof. Even further non limiting examples of the one or more metal deactivators include amino compounds, for example salicylidenepropylenediamine, salicylami-noguanidine and salts thereof, and combinations thereof. The one or more metal deactivators are not particularly limited in amount in the composition but are typically present in an amount of from about 0.01 to about 0.1 , from about 0.05 to about 0.01 , or from about 0.07 to about 0.1 , wt.-% based on the weight of the composition. Alternatively, the one or more metal deactivators may be present in amounts of less than about 0.1 , of less than about 0.7, or less than about 0.5, wt.-% based on the weight of the composition.

Pour point depressants (PPD) include polymethacrylates, alkylated naphthalene derivatives, and combinations thereof. Commonly used additives such as alkylaromatic polymers and polymethacrylates are also useful for this purpose. Typically, the treat rates range from ³

0.001 wt.-% to < 1.0 wt.-%, in relation to the weight of the base stock.

Demulsifiers include trialkyl phosphates, and various polymers and copolymers of ethylene glycol, ethylene oxide, propylene oxide, or mixtures thereof.

Example 1 - Synthesis of PIB alcohol

513g polyisobutylene succinic anhydride (0,4 mol; saponification number of 87.5 mg; Mn 1280 g/mol based on saponification number) was dissolved in 500g toluene under nitrogen resulting in a yellow, clear solution. The solution was heated to 102°C and 43,59g 4-aminophenol (0,4 mol) was added in 2 min. The temperature was increased and kept at 114-118°C for 4h and water continuously separated with a Dean-Stark apparatus in which 4,4ml water was collected. The solvent was then removed at 170°C and 2mbar. Small amount of residual 4-aminophenol crystallized at the neck of the flask.

The yield was 548, 6g.

The analytical data of the product were as follows:

1 H-NMR (CD2CI2): phenyl hydrogens: 6,89 ppm (d), 7,11 ppm (d) Phenyl hydrogens in 4-aminophenol as reference: 6,57 ppm (d), 6,63 ppm (d)

FTIR spectrum of the product shows the significant imide stretching.

OH number: 41 mg KOH/g Acid number: <2 mg KOH/g Example 2 - Synthesis of Macromonomer

A 70% solution of PIB alcohol from Example 1 in a hydrocarbon solvent (576.7g) was stirred and heated to 80°C. Butylhydroxytoluol (0.18 g) and methacrylic anhydride (57.8g) were added and temperature was raised to 90°C. After 1 4h, a 50% solution of NaOH (0.48g) was added. Conversion was controlled by TAI NMR. After 4h, water (121 g) was added. Air (1 L/h) was introduced into the mixture and stirred for 14h. Air was raised to 2L/h. Vacuum was applied and decreased slowly to avoid foaming. Water and methacrylic acid were distilled off untill NMR shows only traces of residual methacrylic acid. Final vacuum was 4 mbar. 592.1 g of a highly viscous oil were obtained. TAI NMR showed full conversion.