EP4747339A1 - Industrial gear lubricant - Google Patents

Abstract

The present technology includes the use of a pour point depressant to improve low temperature viscosity in an industrial gear lubricating composition containing a Group IV base oil. The technology provides an industrial gear lubricating composition comprising a Group IV base oil, a sulfurized olefin, a phosphorus-containing agents, and a poly(meth)acylate polymer pour point depressant.

Description

INDUSTRIAL GEAR LUBRICANT

BACKGROUND OF THE INVENTION

[0001] Industrial gearboxes see extreme operating conditions that can lead to damage, for example, wear to the internal components of the gearbox. This damage reduces the life of the industrial gearbox and can lead to costly and prolonged maintenance, repair costs, unscheduled downtime for the equipment that contains the industrial gearbox, and similar problems.

[0002] Due to the extreme conditions encountered by some industrial gearboxes, low temperature viscosity is an important property of lubricant compositions for industrial gears. However, certain additives used to improve other performance properties of the lubricants can have a negative impact on the low temperature viscosity of certain base oils. Therefore, there is a need to develop industrial gear lubricating compositions that contain additives necessary to protect gearboxes from wear and other detrimental conditions while maintaining low temperature viscosity.

SUMMARY OF THE INVENTION

[0003] The present invention provides a lubricating composition for industrial gears. The industrial gear lubricating composition comprises an additive amount of a poly(meth)acrylate polymer which comprises at least 10 mole percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms.

[0004] In one embodiment, the lubricating composition of the present invention comprises

(a) a base oil, wherein the base oil comprises at least 75 weight percent of Group IV base oil;

(b) at least one sulfurized olefin present in an amount to provide at least 1000 ppm sulfur to the composition; (c) one or more phosphorus-containing agents in an amount to provide at least 100 ppm phosphorus to the composition; and (d) a poly(meth)acylate polymer, wherein the poly(meth)acrylate polymer comprises at least 10 mol percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms.

[0005] The present invention also provides a method of lubricating an industrial gear, a method of improving the low temperature viscosity of an industrial gear lubricant, and the use of a poly(meth)acrylate polymer additive as described herein to improve the low temperature viscosity of a lubricating composition.

[0006] It has been observed that certain additives typically used in industrial gear lubricating compositions have a detrimental impact on the low temperature fluidity of the composition. However, the present invention unexpectedly provides improved low temperature fluidity over similarly additized lubricating compositions as indicated by the Brookfield Viscosity measurement at -40 °C (ASTM D2983).

DETAILED DESCRIPTION OF THE INVENTION

[0007] Various preferred features and embodiments will be described below by way of non-limiting illustration.

[0008] The present technology relates in part to a lubricating composition comprising (a) a base oil, wherein the base oil comprises at least 75 weight percent of Group IV base oil; (b) at least one sulfurized olefin present in an amount to provide at least 1000 ppm sulfur to the composition; (c) one or more phosphorus-containing agents in an amount to provide at least 100 ppm phosphorus to the composition; and (d) a poly(meth)acylate polymer, wherein the poly(meth)acrylate polymer comprises at least 10 mol percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms.

Base Oil

[0009] In the present invention, the base oil is present in a major amount, for a lubricant composition, or in a concentrate forming amount, for a concentrate and/or additive composition.

[0010] Oils of lubricating viscosity may further be defined as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. The five base oil groups are as follows: Group I (sulfur content >0.03 wt%, and/or <90 wt% saturates, viscosity index 80-120); Group II (sulfur content <0.03 wt% and >90 wt% saturates, viscosity index 80- 120); Group III (sulfur content <0.03 wt% and >90 wt% saturates, viscosity index >120); Group IV (all polyalphaolefins, or PAO, such as PAO-2, PAO-4, PAO-5, PAO-6, PAO-7 or PAO-8); and Group V (which encompasses “all others”).

[0011] In the present invention, suitable oils include synthetic and natural lubricating oils and mixtures thereof. In a fully formulated lubricant, the oil of lubricating viscosity is generally present in a major amount (i.e. an amount greater than 50 wt%). Typically, the oil of lubricating viscosity is present in an amount of 75 to 98 wt%, and often greater than 80 wt% of the overall composition.

[0012] The base oil used in the present invention of lubricating viscosity may include natural and synthetic oils, oil derived from hydrocracking, hydrogenation, and hydrofinishing, unrefined, refined and re-refined oils or mixtures thereof. Unrefined oils are those obtained directly from a natural or synthetic source generally without (or with little) 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. Purification techniques are known in the art and include solvent extraction, secondary distillation, acid or base extraction, filtration, percolation and similar processes. Re-refined oils are also known as reclaimed or reprocessed oils and are obtained by processes similar to those used to obtain refined oils. Re-refined oils often are processed by techniques directed to removal of spent additives and oil breakdown products.

[0013] Natural oils useful as the oil of lubricating viscosity include animal oils and vegetable oils (e.g., castor oil, lard oil), 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 and oils derived from coal or shale or mixtures thereof. [0014] The industrial gear lubricant of the present invention comprises a synthetic oil of lubricating viscosity. Synthetic oils may be saturated or unsatureated. Synthetic oils of lubricating viscosity include hydrocarbon oils such as polymerized and interpolymerised olefins (e.g., polybutylenes, polypropylenes, propyleneisobutylene copolymers); poly(l- hexenes), poly(l -octenes), poly(l -decenes), and mixtures thereof; alkyl-benzenes (e.g., dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes); polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls); esters and complex esters from vegetable sourced acids (e.g., diesters, mono esters, saturated polyol esters, trimethyl propane carboxylic esters, neopolyol carboxylic esters, neopentyl glycol esters, pentaerithrytol esters and the like); alkylated biphenyl ethers and alkylated biphenyl sulfides and the derivatives, analogs and homologs thereof or mixtures thereof. In some embodiments the oil of lubricating viscosity used in the invention is a synthetic oil that includes polymerized polyisobutylene, and in some embodiments the oil of lubricating viscosity used in the invention is a synthetic oil that includes polymerized polyisobutylene and a polyalphaolefin.

[0015] Another synthetic oil of lubricating viscosity includes polyol esters, dicarboxylic esters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, and the diethyl ester of decane phosphonic acid), or polymeric tetrahydro furans. Synthetic conventional oil of lubricating viscosity also includes those produced by Fischer- Tropsch reactions and typically may be hydroisomerised Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oil of lubricating viscosity may be prepared by a Fischer- Tropsch gas-to-liquid synthetic procedure as well as other gas-to-liquid oils.

[0016] The present invention includes a base oil that contains at least 75 weight percent of a Group IV base oil. In another embodiment, the base oil contains at least 85% of a Group IV base oil. In still another embodiment, the base oil consists of a Group IV base oil. The Group IV oils useful as the base oils in the present invention include polyalphaolefin base oils. In another embodiment, the base oil comprises a mixture of Group IV base oils, wherein the mixture comprises one or more polyalphaolefin base oils having a kinematic viscosity between 4 and 10 cSt at 100 °C and one or more polyalphaolefin base oils having a kinematic viscosity greater than 50 cSt at 100 °C.

[0017] Viscosity grades generally suitable for industrial gear lubricating compositions are usually ISO 68 to 1000. The viscosity of each grade is the kinematic viscosity at 40 °C +/-10% as measured by ASTM D445 or ISO 3104. As such, an ISO 46 is 46cSt at 40 °C may have a kinematic viscosity of 41.4 - 50.6 cSt at 40 °C. The ISO viscosity classification system is defined in ISO 3448. Exemplary viscosity grades are listed in the table below: [0018] Accordingly, in some embodiments, the lubricating composition of the present invention may have an ISO viscosity grade (VG) of 68 to 1000.

[0019] The various described oils of lubricating viscosity may be used alone or in combinations. The base oil may be used in the described industrial gear lubricants in the range of about 80 wt% to about 98 wt%, or from 80, 85, 90, 95, 97 or even 97.5 or 98 wt% oil or up to 90, 95, 97, 97.5, or even 98 wt% oil.

Sulfurized Olefins

[0020] Sulfurized olefins are well known commercial materials prepared by reacting a single reactant or a mixture of appropriate reactants with a source of sulfur. The sulfurization reaction generally is conducted at an elevated temperature, e.g., 50-350°C or 100-200°C, with efficient agitation and often in an inert atmosphere such as nitrogen, optionally in the presence of an inert solvent. The sulfurizing agents can include elemental sulfur, which is preferred, hydrogen sulfide, sulfur halide, sodium sulfide and a mixture of hydrogen sulfide and sulfur or sulfur dioxide. Usually, the amount of sulfur or sulfurizing agent employed is calculated based on the total olefinic unsaturation of the mixture. Typically, 0.5 to 3 moles of sulfur are employed per mole of olefinic bonds. One type of sulfurized olefin can be prepared in accordance with the detailed teachings of U.S. Pat. No. 4,957,651.

[0021] In the case of sulfurized olefins, the reactant can be an olefinic compound. Olefinic compounds which may be sulfurized are diverse in nature, and broadly speaking are those that contain at least one olefinic double bond, which is defined as a non-aromatic double bond; that is, a double bond connecting two aliphatic carbon atoms. In its broadest sense, the olefin may be defined by the formula R¹R²C=CR³R⁴, wherein each of R¹, R², R³ and R⁴ can be hydrogen or an organic group. In general, the R groups in the above formula which are not hydrogen may be satisfied by such groups as -C(R⁵)s, -COOR⁵, -C00M, -X, -YR⁵ or -Ar, wherein each R⁵ is independently hydrogen, alkyl, alkenyl, aryl, substituted alkyl, substituted alkenyl or substituted aryl, with the proviso that any two R⁵ groups can be alkylene or substituted alkylene whereby a ring of up to 12 carbon atoms is formed; M is one equivalent of a metal cation (preferably Group I or II, e.g., sodium, potassium, barium, calcium); X is halogen (e.g., chloro, bromo, or iodo); Y is oxygen or divalent sulfur; Ar is an aryl or substituted aryl group of up to 12 carbon atoms. Any two of R¹, R², R³ and R⁴ may also together form an alkylene or substituted alkylene group, i.e., the olefinic compound may be alicyclic.

[0022] The olefinic compound is usually one in which each R group, above, which is not hydrogen is independently alkyl, alkenyl or aryl group. Monoolefinic and diolefinic compounds, particularly the former, are preferred, and especially terminal monoolefinic hydrocarbons; that is, those compounds in which R³ and R⁴ are hydrogen and R¹ and R² are alkyl or aryl, especially alkyl (that is, the olefin is aliphatic) having 1 to 30, or 1 to 16, or 1 to 8, or 1 to 4 carbon atoms. Olefinic compounds having 3 to 30 or 3 to 16 (often fewer than 9) carbon atoms can be used.

[0023] Isobutylene, di-isobutylene, butylene, propylene and their dimers, trimers and tetramers, and mixtures thereof are useful as olefinic compounds for sulfurization, as are terpene compounds, that is, various isomeric terpene hydrocarbons having the empirical formula CioHie, as well as various synthetic and naturally occurring oxygen-containing derivatives thereof. [0024] Other sulfurized olefins include those derived from natural sources, such as sulfurized vegetable oils and sulfurized lard oil (that is, sulfurized oils of animal sources generally). Example of natural oils from which such sulfurized olefins may be derived can include, but not be limited to, coconut oil, com oil, cottonseed oil, castor oil, sunflower oil, olive oil, palm oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, tallow, lard, fatty acids, and mixtures thereof. Preferred organic portions for the sulfurized vegetable oil are those derived from sunflower oil, olive oil, and rapeseed oil.

[0025] In one embodiment, the sulfur component of the additive package of the present technology may comprise a biodegradable sulfurized olefin derived from a natural source such as sulfurized vegetable oil or sulfurized lard.

[0026] The total level of sulfur in the sulfurized olefin can be measured according to ASTM D129Q. Whether biodegradable or non-biodegradable, the sulfurized olefins can have a “high,” “nominal,” or “minimal,” level of total sulfur. A “high” level of sulfur means the sulfurized olefin contains about 30 wt% or greater sulfur. A “nominal” level of sulfur means the sulfurized olefin contains from about 10 to about 30 wt% sulfur, and a “minimal” level of sulfur means the sulfurized olefin contains less than about 10 wt% sulfur, or from about 0.01 to about 10 wt% sulfur.

[0027] In the present invention, the sulfurized olefin can be included in the fully formulated lubricant in an amount to provide at least 1000 ppm sulfur to the composition. In some embodiments, the sulfurized olefin is present in an amount to provide 1000 ppm to 3000 ppm or even 1500 ppm to 2500 ppm sulfur to the lubricant composition.

Phosphorous-Containing Agent

[0028] The industrial gear lubricant composition of the present invention also contains a phosphorous containing component, which may be a phosphorus containing antiwear and/or extreme pressure agent. Such phosphorous containing agents that are typically used in industrial gear lubricants are for the most part partially or fully esterified acids of phosphorus. Such phosphorous containing agents include, but are not limited to, acid phosphates, hydrogen phosphites, phosphites, phosphates, phosphonates, phosphinates, and phosphoroamidates. Further antiwear agents can also include mono, di and trihydro carbyl phosphites; mono, di, and trihydrocarbyl phosphates; mono, di, and trihydrocarbyl mono, di, tri, tetrathiophosphates; mono, di, trihydrocarbyl mono, di, tri, tetrathiophosphites; various hydrocarbyl phosphonates and thiophosphonates; dialkyl dithiophosphate esters and derivatives thereof, and various hydrocarbyl phosphonites and thiophosphonites, and the like. [0029] Examples of phosphites include mono-hydrocarbyl substituted phosphite, a di- hydrocarbyl substituted phosphite, or a tri -hydrocarbyl substituted phosphite, and those phosphites having at least one hydrocarbyl group with 4 or more carbon atoms as represented by the formulae: wherein at least one of R⁸, R⁶ and R⁷ may be a hydrocarbyl group containing at least 4 carbon atoms and the other may be hydrogen or a hydrocarbyl group. In one embodiment R⁸, R⁶ and R⁷ are all hydrocarbyl groups. The hydrocarbyl groups may be alkyl, cycloalkyl, aryl, acyclic or mixtures thereof. In the formula with all three groups R⁸, R⁶ and R⁷, the compound may be a tri -hydrocarbyl substituted phosphite i.e., R⁸, R⁶ and R⁷ are all hydrocarbyl groups. Alkyl groups may be linear or branched, typically linear, and saturated or unsaturated, typically saturated. Examples of alkyl groups for R⁸, R⁶ and R⁷ include octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecenyl, nonadecyl, eicosyl or mixtures thereof.

[0030] All of the amine salts that can be formed with the above-mentioned phosphorus containing agents are included. The amines can be primary, secondary, tertiary, acyclic or cyclic, mono or polyamines. They can also be heterocyclic. The preferred amines are generally aliphatic in nature. Some specific examples of amines for producing amine salts of the phosphorus containing antiwear agents include: octylamine, decylamine, CIO, C12, C14 and C16 tertiary alkyl primary amines (or combinations thereof), laurylamine, hexadecylamine, heptadecylamine, octadecylamine, decenylamine, dodecenylamine, palmitoylamine, oleylamine, linoleylamine, di-isoamylamine, di -octylamine, di-(2- ethylhexyl)amine, dilaurylamine, cyclohexylamine, 1,2-propylene amine, 1,3- propylenediamine, diethylene triamine, triethylene tetraamine, ethanolamine, triethanolamine, trioctylamine, pyridine, morpholine, 2-methylpiperazine, l,2-bis(N- piperazinyl-ethane), 1,2-diamine, tetraminooctadecene, triaminooctadecene, N-hexylaniline and the like. The amines may also be triazole or triazole derivatives.

[0031] In an embodiment, an amine salt of the phosphorus containing agent are those of the formula: where R⁹ and R¹⁰ are independently aliphatic groups containing from about 4 up to about 24 carbon atoms, R²² and R²³ are independently hydrogen or aliphatic groups containing from about 1 up to about 18 aliphatic carbon atoms, the sum of m and n is 3 and X is oxygen or sulfur. In a preferred embodiment, R⁹ contains from about 8 up to 18 carbon atoms, R¹⁰ is: wherein R¹¹ is an aliphatic group containing from about 6 up to about 12 carbon atoms, R²² and R²³ are hydrogen, m is 2, n is 1 and X is oxygen.

[0032] Specific examples of phosphorus containing agents can include tricresyl phosphate, tributylphosphite, triphenyl phosphite, 2-ethylhexyl phosphate, diisobutylhydrogen phosphite, diisopropyl dithiophosphate, diphenyl phosphate, fatty phosphites, etc. Some embodiments of phosphorus containing agents can include the dialkyl and diaryl phosphates and their amine salts. Also considered are aryl phosphates, such as the commercially available Irgalube™ 349 from Ciba and alkyl acid phosphates, including di- and/or mono-2-ethylhexyl phosphoric acid.

[0033] Phosphorous containing agents (antiwear or extreme pressure) in the present invention) may be employed in amounts sufficient to deliver 100 ppm to 1000 ppm, or 200 ppm to 500 ppm, or even 300 ppm to 450 ppm phosphorous to the lubricant composition.

Poly(meth)acrylcite Polymer Additive

[0034] The lubricating composition of the present invention also contains a poly(meth)acrylate polymer additive, which also may be referred to as a pour point depressant. Pour point depressants can be added to some lubricating oils to prevent wax crystals from forming in the lubricant at low temperatures. However, Group IV base oils are not considered to contain wax that will crystalize. Therefore, pour point depressant additives are not known to be used in lubricating oil compositions made primarily with Group IV base oils.

[0035] Pour point depressants are known in the art and include but are not limited to esters of maleic anhydride -styrene copolymers, polymethacrylates; polyacrylates; polyacrylamides; condensation products of haloparaffin waxes and aromatic compounds; vinyl carboxylate polymers; and terpolymers of dialkyl fumarates, vinyl esters of fatty acids, ethylene -vinyl acetate copolymers, alkyl phenol formaldehyde condensation resins, alkyl vinyl ethers and mixtures thereof. In one embodiment, a pour point depressant polymer is used which comprises a poly(meth)acylate polymer, wherein the poly(meth)acrylate polymer comprises at least 10 mol percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms. In one embodiment, the (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms comprises stearyl methacrylate. As used herein, the term “(meth)acrylate” means either methacrylate or acrylate, as will be readily understood.

[0036] In one embodiment, the poly(meth)acrylate polymer is prepared from a monomer mixture comprising (meth)acrylate monomers having alkyl groups of varying length. The (meth)acrylate monomers may contain alkyl groups that are straight chain or branched chain groups or aromatic groups.

[0037] In one embodiment of the present invention, a pour point depressant additive is used which comprises a poly(meth)acylate polymer, wherein the poly(meth)acrylate polymer comprises at least 10 mol percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms. In one embodiment, the poly(meth)acrylate polymer additive comprises 10 mol% to 50 mol%, or 15 mol% to 35 mol%, or even 20 mol% to 30 mol% of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms, or 16 to 20 carbon atoms, or even 16 to 18 carbon atoms. In one embodiment, the poly(meth)acrylate polymer additive comprises 10 mol% to 50 mol%, or 15 mol% to 35 mol%, or even 20 mol% to 30 mol% of stearyl methacrylate.

[0038] The poly(meth)acrylate polymer additive may also comprise at least 50 mol%, or 50 mol% to 90 mol%, or 65 mol% to 85 mol%, or even 70 mol% to 80 mol% of a (meth)acrylic acid alkyl ester monomer having an alkyl group containing 12 to 15 carbon atoms. In some embodiments, the poly(meth)acrylate polymer used in the present invention may also contain up to 10 mol% of any other monomer capable of copolymerizing with the (meth)acrylic acid alkyl ester monomer having an alkyl group containing 16 or more carbon atoms. For instance, the poly(meth)acrylate polymer additive may optionally include 0 to 10 mol% or even 0.5 mol% to 5 mol%, or even 1 mol% to 3 mol% of (meth)acrylic acid ester monomer having an alkyl group containing 1 to 10 carbon atoms, for example 4 to 8 carbon atoms. In another embodiment, the poly(meth)acrylate polymer additive may optionally include 0 to 10 mol% or even 0.5 mol% to 5 mol%, or even 1 mol% to 3 mol% of a dispersant monomer which contains a heteroatom selected from nitrogen or sulfur. In another embodiment, the poly(meth)acrylate polymer additive may optionally include 0 to 10 mol% or even 0.5 mol% to 5 mol%, or even 1 mol% to 3 mol% of an aromatic monomer, such as benzyl methacrylate, phenyl methacrylate, phenylpropyl methacrylate, or styrene.

[0039] In one embodiment, the poly(meth)acrylate polymer may include a dispersant monomer; dispersant monomers include those monomers which may copolymerize with (meth)acrylate monomers and contain one or more heteroatoms in addition to the carbonyl group of the (meth)acrylate. The dispersant monomer may contain a nitrogen-containing group, an oxygen-containing group, or mixtures thereof. For example, the dispersant monomer may include a (meth)acrylamide or a nitrogen containing (meth)acrylate monomer. Examples of a suitable nitrogen-containing compound include N,N-dimethylacrylamide, N-vinyl carbonamides such as N-vinyl-formamide, vinyl pyridine, N-vinylacetoamide, N-vinyl propionamides, N-vinyl hydroxyacetoamide, N-vinyl imidazole, N-vinyl pyrrolidinone, N-vinyl caprolactam, dimethylaminoethyl acrylate (DMAEA), dimethylaminoethyl methacrylate (DMAEMA), dimethylaminobutyl acrylamide, dimethylaminopropyl meth-acrylate (DMAPMA), dimethylaminopropyl acrylamide, dimethyl-aminopropyl methacrylamide, dimethylaminoethyl acrylamide or mixtures thereof.

[0040] In one embodiment, the poly(meth)acrylate comprises a block copolymer or tapered block copolymer. Block copolymers are formed from a monomer mixture comprising one or more (meth)acrylate monomers, wherein, for example, a first (meth)acrylate monomer forms a discrete block of the polymer joined to a second discrete block of the polymer formed from a second (meth)acrylate monomer. While block copolymers have substantially discrete blocks formed from the monomers in the monomer mixture, a tapered block copolymer may be composed of, at one end, a relatively pure first monomer and, at the other end, a relatively pure second monomer. The middle of the tapered block copolymer is more of a gradient composition of the two monomers.

[0041] In one embodiment, the poly(meth)acrylate polymers useful in the present invention may have an architecture selected from linear, branched, hyper-branched, cross-linked, star (also referred to as “radial”), or combinations thereof. Star or radial refers to multi -armed polymers. Such polymers include (meth)acrylate -containing polymers comprising 3 or more arms or branches, which, in some embodiments, contain at least about 20, or at least 50 or 100 or 200 or 350 or 500 or 1000 carbon atoms. The arms are generally attached to a multivalent organic moiety which acts as a “core” or “coupling agent.” The multi-armed polymer may be referred to as a radial or star polymer, or even a “comb” polymer, or a polymer otherwise having multiple arms or branches as described herein.

[0042] Star polymers may be prepared by a number of known polymerization methods, including atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT) polymerization, nitroxide mediated polymerization (NMP), or anionic polymerization. A detailed discussion of ATRP is given in Chapter 11, pages 523 to 628 of the Handbook of Radical Polymerization, Edited by Krzysztof Matyjaszewski and Thomas P. Davis, John Wiley and Sons, Inc., 2002 (hereinafter referred to as “Matyjaszewski”). See in particular reaction scheme 11.1 on page 524, 11.4 on page 556, 11.7 on page 571, 11.8 on page 572, and 11.9 on page 575.

[0043] RAFT polymerization may be employed when the core portion of the polymer contains a functional group of formula (I) above wherein Y is represented by -S-C(=S)-R⁵ where R⁵ may be an alkyl radical containing 1 to 20 carbon atoms. The Y functionality may be derived from or be a portion of a chain transfer agent. In certain embodiments the core portion comprises a functional group (often from a chain transfer agent) derived from a compound comprising a thiocarbonyl thio group and a free radical leaving groups, such as those disclosed in paragraph 0146 of U.S. Application 2007/0244018.

[0044] Examples of RAFT chain transfer agents include benzyl l-(2-pyrrolidinone)- carbodithioate, benzyl (l,2-benzenedicarboximido)carbodithioate, 2 -cyanoprop -2 -yl 1- pyrrolecarbodithioate, 2-cyanobut-2-yl 1-pyrrolecarbodithioate, benzyl 1-imidazole- carbodithioate, N,N-dimethyl-S-(2-cyanoprop-2-yl)dithiocarbamate, N,N-diethyl-S-benzyl dithiocarbamate, cyanomethyl l-(2-pyrrolidone)carbodithoate, cumyl dithiobenzoate, N,N- diethyl S-(2-ethoxycarbonylprop-2-yl)dithiocarbamate, O-ethyl-S-( 1 -phenyl ethyl)xanthtate,

O-ethyl-S-(2-(ethoxycarbonyl)prop-2-yl)xanthate, O-ethyl-S-(2-cyanoprop-2-yl)xanthate, O- ethyl-S-(2-cyanoprop-2-yl)xanthate, O-ethyl-S-cyanomethyl xanthate, O-phenyl-S-benzyl xanthate, O-pentafluorophenyl-S-benzyl xanthate, 3-benzylthio-5,5-dimethylcyclohex-2-ene- 1-thione or benzyl 3,3-di(benzylthio)prop-2-enedithioate, S,S'-bis-(a,a'-disubstituted-a"- acetic acid) -trithiocarbonate, S,S'-bis-(a,a'-disubstituted-a"-acetic acid)-trithiocarbonate or S- alkyl-S'-(-(a,a'-disubstituted-a"-acetic acid)-trithiocarbonates, dithiobenzoic acid, 4- chlorodithiobenzoic acid, benzyl dithiobenzoate, 1 -phenyl ethyl dithiobenzoate, 2-phenylprop- 2-yl dithiobenzoate, 1 -acetoxyethyl dithiobenzoate, hexakis(thiobenzoylthiomethyl)benzene, l,4-bis(thiobenzoylthiomethyl)benzene, l,2,4,5-tetrakis(thiobenzoylthiomethyl)benzene, 1,4- bis-(2-(thiobenzoylthio)prop-2-yl)benzene, l-(4-methoxyphenyl)ethyl dithiobenzoate, benzyl dithioacetate, ethoxycarbonylmethyl dithioacetate, 2-(ethoxycarbonyl)prop-2-yl dithiobenzoate, 2,4,4-trimethylpent-2-yl dithiobenzoate, 2-(4-chlorophenyl)prop-2-yl dithiobenzoate, 3-vinylbenzyl dithiobenzoate, 4-vinylbenzyl dithiobenzoate, S-benzyl diethoxyphosphinyldithioformate, tert-butyl trithioperbenzoate, 2-phenylprop-2-yl 4-chloro- dithiobenzoate, 2-phenylprop-2-yl 1-dithionaphthalate, 4-cyanopentanoic acid dithiobenzoate, dibenzyl tetrathioterephthalate, dibenzyl trithiocarbonate, carboxymethyl dithiobenzoate or polyethylene oxide) with dithiobenzoate end group or mixtures thereof. RAFT polymerization is also described in greater detail in Chapter 12, pages 629 to 690 of Matyjaszewski, especially pages 664 to 665.

[0045] For example, a star polymer, may comprise (i) a core portion comprising a polyvalent (meth) acrylic monomer, oligomer or polymer thereof or a polyvalent divinyl nonacrylic monomer, oligomer or polymer thereof; and (ii) at least three arms of polymerized alkyl (meth)acrylate esters. In one embodiment, the arms of the star polymer may be random copolymers or, more preferably for this invention, block or tapered block copolymers. The core portion may comprise a functional group of formula (la): wherein E is independently another part of the core, a polymeric arm or to a monomeric species, or another structural unit as defined by formula (la); R¹ is hydrogen or a linear or branched alkyl group containing 1 to 5 carbon atoms; A is nitrogen or oxygen; and Y is a free radical leaving group selected from the group consisting of one or more atoms or groups of atoms which may be transferred by a radical mechanism under the polymerization conditions, a halogen, a nitroxide group,, or a dithio ester group. Analogous to structure (Iz), the bond shown at the left of structure (la) may typically be attached to a Z group, where Z is a polymeric group such as a crosslinked polymeric group.

[0046] Examples of the polyvalent unsaturated (meth)acrylic monomer useful for forming the polymer core include ethylene glycol diacrylate, ethylene glycol di(meth)acrylate, diethylene glycol diacrylate, diethylene glycol di(meth)acrylate, glycerol diacrylate, glycerol triacrylate, mannitol hexaacrylate, 4-cyclohexanediol diacrylate, 1,4- benzenediol di(meth)acrylate, neopentylglycol diacrylate, 1,3 -propanediol diacrylate, 1,5- pentanediol di(meth)acrylate, bis-acrylates and bis-(meth)acrylates of polyethylene glycols of molecular weight 200-4000, polycaprolactonediol diacrylate, 1,1,1 -trimethylolpropane diacrylate, 1,1,1 -trimethylolpropane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, triethylene glycol diacrylate, triethylene glycol di(meth)acrylate, 1 , 1 , 1 -trimethylolpropane tri(meth)acrylate, hexamethylenediol diacrylate or hexamethylenediol di(meth)acrylate, vinyl (meth)acrylate, allyl (meth)acrylate or an alkylene bis-(meth)acrylamide.

[0047] Examples of the polyvalent or divalent unsaturated non-acrylic monomer useful for forming the polymer core include divinylbenzene, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, poly(ethylene glycol) divinyl ether, butanediol divinyl ether, bicyclo[2.2.1]hepta-2,5-diene.

[0048] The amount of core portion or coupling agent may be an amount suitable to provide coupling of previously prepared polymeric arms onto the core in monomeric, oligomeric, or polymeric form, to provide a star polymer. As described above, suitable amounts may be determined readily by the person skilled in the art with minimal experimentation, even though several variables may be involved. For example, if an excessive amount of coupling agent is employed, or if excessive unreacted monomer from the formation of the polymeric arms remains in the system, crosslinking rather than star formation may occur. Typically the mole ratio of polymer arms to coupling agent may be 50: 1 to 1.5: 1 (or 1: 1), or 30: 1 to 2: 1, or 10: 1 to 3: 1, or 7: 1 to 4: 1, or 4: 1 to 1: 1. In other embodiments the mole ratio of polymer arms to coupling agent may be 50: 1 to 0.5: 1, or 30: 1 to 1: 1, or 7: 1 to 2: 1. The desired ratio may also be adjusted to take into account the length of the arms, longer arms sometimes tolerating or requiring more coupling agent than shorter arms.

[0049] The arms of the star polymer may themselves be (meth)acrylate-containing polymer or oligomer moieties, comprising (meth)acrylic moieties condensed with alcohol moieties to provide alkyl groups. The arms of the star polymer as described herein may be block or tapered block copolymers as described above. In one embodiment the star polymer comprises at least 3 arms, in another embodiment at least 5 arms, in another embodiment at least 7 arms, in another embodiment at least 10 arms, for instance 12 to 100, 14 to 50, or 16 to 40 arms. In one embodiment the star polymer may have 120 arms or less, in another embodiment 80 arms or less, in another embodiment 60 arms or less. In certain embodiments there may be 3 to 20, 5 to 20, or 6 to 15, or 7 to 8 arms per star. Such multi-armed polymers and their preparation are described in greater detail in WO2015/142482, September 24, 2015, see in particular paragraphs 0017 through 0064.

[0050] The molecular weight of the poly(meth)acrylate polymers may be determined using known methods, such as Gel Permeation Chromatography (“GPC” analysis using polystyrene standards. Methods for determining molecular weights of polymers are well known. The methods are described for instance: (i) P. J. Flory, "Principles of Polymer Chemistry", Cornell University Press 91953), Chapter VII, pp 266-315; or (ii) "Macromolecules, an Introduction to Polymer Science", F. A. Bovey and F. H. Winslow, Editors, Academic Press (1979), pp 296-312.

[0051] Linear poly(meth)acrylates of the invention as described herein, random, block or otherwise, may have weight average molecular weight (M_w) of 1000 to 400,000 Daltons, or 5,000 to 50,000 Daltons, or even 5,000 to 200,000 Daltons, or even 5000 to 150,000 Daltons, or even 8,000 to 100,000, or 10,000 to 80,000 Daltons.

[0052] Radial, cross-linked or star copolymers of the invention may be derived from linear random or di-block copolymers with molecular weights as described above. A star polymer of the invention may have a weight average molecular weight of 10,000 to 1,500,000 Daltons, or 40,000 to 1,000,000 Daltons, or 300,000 to 850,000 Daltons.

[0053] In one embodiment, the poly(meth)acrylate polymer used in the present invention comprises or consists of a linear poly(meth)acrylate polymer.

Other Additives

[0054] The industrial gear lubricant can contain further additive components suitable for industrial gear lubricants. Any combination of conventional additive components suitable for use in industrial gear applications may be used.

[0055] The further additive components which may be present in the industrial gear additive package in addition to the sulfurized olefins, phosphorous containing agent, and poly(meth)acrylate polymer described above include, but are not limited to, foam inhibitors, demulsifiers, antioxidants, dispersants, metal deactivators (such as copper deactivators), phosphorus containing antiwear agents, viscosity modifiers, detergents, or some mixture thereof. The other additive components may each be present in the range from 50, 75, 100 or even 150 ppm up to 10, 9, 8, 7, 6, 5, 4, 3, 2 or even 1.5 wt%, or from 75 ppm to 0.5 wt%, from 100 ppm to 0.4 wt%, or from 150 ppm to 0.3 wt%, where the wt% values are with regards to an individual component in respect of a fully formulated industrial gear lubricant. However, it is noted that some additives, including viscosity modifying polymers, which may alternatively be considered as part of the oil of lubricating viscosity, may be present in higher amounts including up to 30, 40, or even 50% by weight when considered separate from the oil of lubricating viscosity. The additives may be used alone or as mixtures thereof. [0056] In one embodiment, the lubricating composition contains a branched hydrocarbyl alcohol. The branched hydrocarbyl group of the alcohol may be -branched and may contain 8 to 60, or 8 to 30, or 8 to 16 carbon atoms. Examples of branched alcohols include, but are not limited to 2-ethylhexanol, 2-butyloctanol, 2-hexyldecanol, 2-octyldodecanol, 2- decyltetradecanol, or mixtures thereof. Commercially available branched alcohols, which may be useful in the present invention, include the Isofol® branched Guerbet alcohols available from Sasol.

[0057] Antifoams, also known as foam inhibitors, are known in the art and include but are not limited to organic silicones and non-silicon foam inhibitors. Examples of organic silicones include dimethyl silicone and polysiloxanes. Examples of non-silicon foam inhibitors include but are not limited to polyethers, polyacrylates and mixtures thereof as well as copolymers of ethyl acrylate, 2-ethylhexylacrylate, and optionally vinyl acetate. In some embodiments the antifoam is a polyacrylate. Antifoams may be present in the composition from 0.001 to 0.012 or 0.004 wt% or even 0.001 to 0.003 wt%.

[0058] Demulsifiers are known in the art and include but are not limited to derivatives of propylene oxide, ethylene oxide, polyoxyalkylene alcohols, alkyl amines, amino alcohols, diamines or polyamines reacted sequentially with ethylene oxide or substituted ethylene oxides or mixtures thereof. Examples of demulsifiers include polyethylene glycols, polyethylene oxides, polypropylene oxides, (ethylene oxide-propylene oxide) polymers and mixtures thereof. In some embodiments the demulsifiers are polyethers. Demulsifiers may be present in the composition from 0.002 to 0.2 wt%.

[0059] The compositions of the present technology may also include a rust inhibitor. Suitable rust inhibitors include hydrocarbyl amine salts of dialkyldithiophosphoric acid, hydrocarbyl amine salts of hydrocarbyl arenesulphonic acid and fatty carboxylic acids or esters thereof, an ester of a nitrogen-containing carboxylic acid, an ammonium sulfonate, an imidazoline, mono-thio phosphate salts or esters, or any combination thereof, or mixtures thereof.

[0060] Examples of hydrocarbyl amine salts of dialkyldithiophosphoric acid of the technology include but are not limited to the reaction product(s) of diheptyl or dioctyl or dinonyl dithiophosphoric acids with ethylenediamine, morpholine or Primene™ 81R or mixtures thereof.

[0061] Suitable hydrocarbyl amine salts of hydrocarbyl arenesulphonic acids used in the rust inhibitor package of the technology are represented by the formula: wherein Cy is a benzene or naphthalene ring. R¹² is a hydrocarbyl group with about 4 to about 30, preferably about 6 to about 25, more preferably about 8 to about 20 carbon atoms, z is independently 1, 2, 3, or 4 and most preferably z is 1 or 2. R¹³, R¹⁴ and R¹⁵ are independently hydrogen, alkyl branched or linear alkyl chains, and in some embodiments at least one, or even two of R¹³, R¹⁴ and R¹⁵ are hydrogen, and further where at least one of R¹³, R¹⁴ and R¹⁵ is a hydrocarbyl group containing at least 8 carbon atoms. Examples of alkyl groups suitable for R¹³, R¹⁴ and R¹⁵ include but are not limited to butyl, sec butyl, isobutyl, tert-butyl, pentyl, n-hexyl, sec-hexyl, n-octyl, 2-ethyl, hexyl, ethyl-hexyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecenyl, nonadecyl, eicosyl or mixtures thereof. Examples of hydrocarbyl amine salts of hydrocarbyl arene sulphonic acid of the technology include but are not limited to the ethylenediamine salt of dinonylnaphthalene sulfonic acid. Examples of suitable fatty carboxylic acids or esters thereof include glycerol monooleate and oleic acid.

[0062] An example of a suitable ester of a nitrogen-containing carboxylic acid includes oleyl sarcosine. The rust inhibitors may be present in the range from 0.02 to 0.2, from 0.03 to 0.15, from 0.04 to 0.12, or from 0.05 to 0.1 wt% of the industrial gear lubricant. The rust inhibitors of the present technology may be used alone or in mixtures thereof.

[0063] The compositions of the present technology may also include a metal deactivator. Metal deactivators are used to neutralise the catalytic effect of metal for promoting oxidation in the industrial gear lubricant. Suitable metal deactivators include but are not limited to triazoles, tolyltriazoles, a thiadiazole, or combinations thereof, as well as derivatives thereof. Examples include derivatives of benzotriazoles, benzimidazole, 2- alkyldithiobenzimidazoles, 2-alkyldithiobenzothiazoles, 2-(N,N’-dialkyldithio- carbamoyl)benzothiazoles, 2,5-bis(alkyl-dithio)-l,3,4-thiadiazoles, 2,5-bis(N,N’- dialkyldithiocarbamoyl)-l,3,4-thiadiazoles, 2-alkyldithio-5-mercapto thiadiazoles or mixtures thereof. These additives may be used from 0.01 to 0.25 wt% in the overall composition. In some embodiments the metal deactivator is a hydrocarbyl substituted benzotriazole compound. The benzotriazole compounds with hydrocarbyl substitutions include at least one of the following ring positions 1- or 2- or 4- or 5- or 6- or 7- benzotriazoles. The hydrocarbyl groups contain about 1 to about 30, preferably about 1 to about 15, more preferably about 1 to about 7 carbon atoms, and most preferably the metal deactivator is 5 -methylbenzotriazole used alone or mixtures thereof. The metal deactivators may be present in the range from 0.001 to 0.5, from 0.01 to 0.04 or from 0.015 to 0.03 wt% of the industrial gear lubricant. Metal deactivators may also be present in the composition from 0.002 or 0.004 to 0.02 wt%. The metal deactivator may be used alone or mixtures thereof.

[0064] Antioxidants may also be present including (i) an alkylated diphenylamine, and (ii) a substituted hydrocarbyl mono-sulfide. In some embodiments the alkylated diphenylamines of the technology are bis-nonylated diphenylamine and bis-octylated diphenylamine. In some embodiments the substituted hydrocarbyl monosulfides include n- dodecyl-2-hydroxyethyl sulfide, l-(tert-dodecylthio)-2-propanol, or combinations thereof. In some embodiments the substituted hydrocarbyl monosulfide is l-(tert-dodecylthio)-2- propanol. The antioxidant package may also include sterically hindered phenols. Examples of suitable hydrocarbyl groups for the sterically hindered phenols include but are not limited to 2-ethylhexyl or n-butyl ester, dodecyl or mixtures thereof. Examples of methylene- bridged sterically hindered phenols include but are not limited to 4,4'-methylene-bis(6-tert- butyl o-cresol), 4,4 -methylene-bis(2-tert-amyl-o-cresol), 2,2 -methylene-bis(4-methyl-6- tert-butylphenol), 4,4 -methylene-bis(2,6-di-tertbutylphenol) or mixtures thereof. The antioxidants may be present in the composition from 0.01 wt% to 6.0 wt%, or from 0.02 wt% to 1 wt%. The additive may be present in the composition at 1 wt%, 0.5 wt%, or less.

[0065] In some embodiments the industrial gear lubricant additive package of the present technology includes a nitrogen-containing dispersant, for example a hydrocarbyl substituted nitrogen containing additive. Suitable hydrocarbyl substituted nitrogen containing additives include ashless dispersants and polymeric dispersants. Ashless dispersants are so-named because, as supplied, they do not contain metal and thus do not normally contribute to sulfated ash when added to a lubricant. However, they may, of course, interact with ambient metals once they are added to a lubricant which includes metal -containing species. Likewise, some derivatives of ashless dispersants may be derivatized and contain ash forming molecules, such as, for example, borated derivatives. Ashless dispersants are characterized by a polar group attached to a relatively high molecular weight hydrocarbon chain. Examples of such materials include succinimide dispersants, Mannich dispersants, and borated derivatives thereof.

[0066] In one embodiment, the lubricating composition of the present invention may contain a detergent. In some embodiments, the detergent may be a metal-containing detergent. In some embodiments, the metal -containing detergent may be a calcium or magnesium detergent. In one embodiment, the metal-containing detergent may also be an overbased detergent with total base number ranges from 30 to 500 mg KOH/g equivalents. In another embodiment, the metalcontaining detergent may be a neutral detergent having a total base number of 0 to 30, or even 0 to 10, or even 30 or lower, or even 10 or lower mg KOH/g equivalents. Detergents may be chosen from non-sulfur containing phenates, sulfur containing phenates, sulfonates, salixarates, salicylates, and mixtures thereof, or borated equivalents thereof. Detergents may be borated with a borating agent such as boric acid such as a borated overbased calcium or magnesium sulfonate detergent, or mixtures thereof. The detergent may be present at 0 wt % to 5 wt %, or 0.001 wt % to 1.5 wt %, or 0.005 wt % to 1 wt %, or 0.01 wt % to 0.5 wt % of the hydraulic composition. In some embodiments, the lubriating compsoition of the present invention is substantially free of free of metal -containing detergents.

[0067] In some embodiments the industrial gear additive packages, or the resulting industrial gear lubricant compositions, include a demulsifier, a corrosion inhibitor, a friction modifier, or combination of two or more thereof. In some embodiments the corrosion inhibitor includes a tolyltriazole. In still other embodiments the industrial gear additive packages, or the resulting industrial gear lubricant compositions, include one or more polysulfides; one or more phosphorus amine salts; one or more thiophosphate esters, one or more thiadiazoles, tolyltriazoles, polyethers, and/or alkenyl amines; one or more ester copolymers; one or more carboxylic esters; one or more succinimide dispersants, or any combination thereof.

[0068] In an industrial gear lubricating composition of the present invention, the oil of lubricating viscosity, may be present from 80%, 85%, 90%, 95%, 97% or even 97.5% or 98% by weight oil up to 90%, 95%, 97%, 97.5%, or even 98% by weight; the sulfurized olefin in amounts of about 0.1% to about 0.9%, or about 0.2% to about 0.8%, or about 0.4% to about 0.6% by weight, and the zinc dialkyl dithiophosphate in amounts of about 0.05% to about 0.8%, or about 0.1% to about 0.6%, or about 0.15% to about 0.5%, or even about 0.2% to about 0.4% by weight. Preferably, the industrial gear lubricating composition contains a maximum of about 6000 ppm sulfur, no more than about 3000 ppm of which is delivered by the sulfurized olefin.

[0069] The industrial gear lubricant of the present technology can meet the performance requirements required of an industrial gear lubricant, as well as standards set for environmental friendliness.

[0070] Industrial gear oils (IGOs) must maintain a specified level of performance in the typical bench tests that have been part of well-known industrial gear approvals like USS 224, AGMA 9005-D94, recently replaced by AGMA 9005-E02, DIN 51517-3:2009-06, Fives Cincinnati, etc. With respect to extreme pressure performance, the bench tests include, for example, Four Ball EP (ASTM D2783), Timken (ASTM D2782). Other tests include Four Ball Wear (ASTM D4172), FZG Scuffing (DIN ISO 14635-1), Copper Corrosion Protection (ASTM D130, ISO 2160), Oxidation Control (ASTM D2893, DIN EN ISO 4263- 4, S-200), Rust Prevention (ASTM D665, ISO 7120), Static Seal Compatibility (DIN EN ISO 1817), Demulsibility (ASTM D2711, ASTM D1401, ISO 6614), Foam Control (ASTM D892, ISO 6247), etc.

[0071] The invention includes methods of making the industrial gear lubricants and/or the industrial gear additive concentrates described above. Such methods include mixing the described components together. No particular order or means of addition is believed to significantly impact the results.

[0072] The invention also includes a method adding one of the industrial gear lubricants described herein to an industrial gearbox and then operating that industrial gearbox. [0073] As used herein, the term “condensation product” is intended to encompass esters, amides, imides and other such materials that may be prepared by a condensation reaction of an acid or a reactive equivalent of an acid (e.g., an acid halide, anhydride, or ester) with an alcohol or amine, irrespective of whether a condensation reaction is actually performed to lead directly to the product. Thus, for example, a particular ester may be prepared by a transesterification reaction rather than directly by a condensation reaction. The resulting product is still considered a condensation product.

[0074] The amount of each chemical component described is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, that is, on an active chemical basis, unless otherwise indicated. However, 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, derivatives, and other such materials which are normally understood to be present in the commercial grade.

[0075] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include: hydrocarbon substituents, including aliphatic, alicyclic, and aromatic substituents; substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this technology, do not alter the predominantly hydrocarbon nature of the substituent; and hetero substituents, that is, substituents which similarly have a predominantly hydrocarbon character but contain other than carbon in a ring or chain. A more detailed definition of the term "hydrocarbyl substituent" or "hydrocarbyl group" is found in paragraphs [0137] to [0141] of published application US 2010-0197536.

[0076] 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 technology 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 technology; the present technology encompasses the composition prepared by admixing the components described above.

EXAMPLES

[0077] A series of lubricants are prepared as shown in Table 1. Table 1 - Lubricant Formulations¹

¹ All treat rates are oil free unless otherwise indicated

² Top treated with foam inhibitor (4 ppm)

³ Polyalphaolefin base oil having a kinematic viscosity at 100°C (KV100) of 5.8cSt ⁴ Polyalphaolefin base oil having a kinematic viscosity at 100°C (KV100) of 158 cSt

⁵ Other additives include foam inhibitor, corrosion inhibitors, and polyether compatibilizers

⁶ Group II diluent oil contained in additives [0078] Advantages of the lubricating composition of the present invention may also be show by evaluation of the lubricating composition according to various tests including but not limited to 4-ball wear (ASTM D4172), 4-ball EP (ASTM D2783), Oxidation (ASTM D2893 at 121C), Oxidation (ASTM D2893 at 95C), Steel corrosion (ASTM D665B), Copper corrosion (ASTM D130, 3h, 100C), Demulse (ASTM D2711B), Foam (ASTM D892), FZG scuffing A/8.3/90 (ASTM D5182), FE-8 (DIN 51819-3).

[0079] Particular aspects of the present invention are more fully set out in the following clauses. [0080] Clause 1: An industrial gear lubricating composition comprising: (a) a base oil, wherein the base oil comprises at least 75 weight percent of Group IV base oil; (b) at least one sulfurized olefin present in an amount to provide at least 1000 ppm sulfur to the composition; (c) one or more phosphorus-containing agents in an amount to provide at least 100 ppm phosphorus to the composition; and (d) a poly(meth)acylate polymer, wherein the poly(meth)acrylate polymer comprises at least 10 mol percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms.

[0081] Clause 2: The composition of clause 1, wherein the sulfurized olefin is present in an amount to provide 1000 ppm to 3000 ppm sulfur to the composition.

[0082] Clause 3: The composition of any preceding clause, wherein the sulfurized olefin is present in an amount to provide 1500 ppm to 2500 ppm sulfur to the composition.

[0083] Clause 4: The composition of any preceding clause, wherein the one or more phosphorus containing agents is present in an amount to provide 100 ppm to 1000 ppm phosphorus to the composition.

[0084] Clause 5: The composition of any preceding clause, wherein the one or more phosphorus containing agent s is present in an amount to provide 200 ppm to 500 ppm phosphorus to the composition.

[0085] Clause 6: The composition of any preceding clause, wherein the one or more phosphorus containing agent s is present in an amount to provide 300 ppm to 450 ppm phosphorus to the composition.

[0086] Clause 7: The composition of any preceding clause, wherein the polymethacrylate polymer comprises 10 mol percent to 50 mol percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms.

[0087] Clause 8: The composition of any preceding clause, wherein the polymethacrylate polymer comprises 15 mol percent to 35 mol percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms.

[0088] Clause 9: The composition of any preceding clause, wherein the polymethacrylate polymer comprises 20 mol percent to 30 mol percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms.

[0089] Clause 10: The composition of any preceding clause, wherein the (meth)acrylic acid alkyl ester monomer comprises or consists of stearyl methacrylate.

[0090] Clause 11 : The composition of any preceding clause, wherein the poly(meth)acrylate polymer comprises 50 mol percent to 90 mol percent of (meth)acrylic acid alkyl ester monomers containing 8 to 15 carbon atoms. [0091] Clause 12: The composition of any preceding clause, wherein the poly(meth)acrylate polymer comprises 65 mol percent to 85 mol percent of (meth)acrylic acid alkyl ester monomers containing 8 to 15 carbon atoms.

[0092] Clause 13 : The composition of any preceding clause, wherein the poly(meth)acrylate polymer comprises 70 mol percent to 80 mol percent of (meth)acrylic acid alkyl ester monomers containing 8 to 15 carbon atoms.

[0093] Clause 14: The composition of any of clauses 11 to 13, wherein the (meth)acrylic acid alkyl ester monomer containing 8 to 15 carbon atoms comprises or consists of lauryl methacrylate.

[0094] Clause 15 : The composition of any preceding clause, wherein the poly(meth)acrylate polymer optionally contains another monomer that can copolymerize with the (meth)acrylic acid alkyl ester monomer.

[0095] Clause 16: The composition of any preceding clause, wherein the wherein the poly(meth)acrylate polymer contains up to 10 mol percent or up to 5 mol percent of another monomer that can copolymerize with the (meth)acrylic acid alkyl ester monomer.

[0096] Clause 17 : The composition of any preceding clause, wherein the poly(meth) acrylate polymer optionally includes a monomer having 1 to 10 or 4 to 8 carbon atoms.

[0097] Clause 18: The composition of clause 17, wherein the poly(meth)acrylate polymer contains 0 to 10 mol percent of a monomer containing 1 to 10 or 4 to 8 carbon atoms.

[0098] Clause 19: The composition of clause 18, wherein the poly(meth)acrylate polymer contains up to 1 mol percent to 5 mol percent of a monomer containing 1 to 10 or 4 to 8 carbon atoms.

[0099] Clause 20: The composition of any preceding clause, wherein the poly(meth)acrylate polymer is present in an amount of 0.05 to 0.5 weight percent of the composition.

[00100] Clause 21 : The composition of any preceding clause, wherein the poly(meth)acrylate polymer is present in an amount of 0.1 to 0.4 weight percent of the composition.

[00101] Clause 22: The composition of any preceding clause, further comprising a branched hydrocarbyl alcohol containing 10 or more carbon atoms.

[00102] Clause 23 : The composition of clause 22, wherein the branched hydrocarbyl alcohol comprises a beta-branched alcohol containing 12 or more carbon atoms.

[00103] Clause 24: The composition of any preceding clause, wherein the base oil comprises at least 85 weight percent of Group IV base oil.

[00104] Clause 25 : The composition of any preceding clause, wherein the base oil is a mixture of Group IV base oils, wherein the mixture comprises one or more polyalphaolefin base oils having a kinematic viscosity between 4 and 10 cSt at 100 °C and one or more polyalphaolefin base oils having a kinematic viscosity greater than 50 cSt at 100 °C.

[00105] Clause 26: The composition of any preceding clause, wherein the phosphorus- containing agent comprises hydrocarbyl phosphite, hydrocarbyl phosphonate, hydrocarbyl phosphate ester, hydrocarbyl amine salt of di-, or tri-hydrocarbylphosphoric acid, or any combination thereof.

[00106] Clause 27: The composition of any preceding clause, wherein the phosphorus containing agent comprises dioleyl phosphite.

[00107] Clause 28: The composition of any preceding clause, wherein the phosphorous containing agent comprises (2-ethylhexyl)amine salt of iso-octyl phosphate.

[00108] Clause 29: The composition of any preceding clause, wherein the sulfurized olefin comprises an olefin containing 4 to 12 carbon atoms.

[00109] Clause 30: The composition of any preceding clause, wherein the sulfurized olefin comprises sulfurized isobutylene.

[00110] Clause 31 : The composition of any preceding clause, wherein the composition has a kinematic viscosity at 40 °C of at least 150 cSt.

[00111] Clause 32: A method of lubricating an industrial gear comprising supplying to the gear a lubricating composition of any preceding clause.

[00112] Clause 33: A method of improving the low temperature viscosity of an industrial gear lubricant, comprising supplying to the gear a lubricating composition of any of clauses 1 to 31.

[00113] Clause 34: The use of a poly(meth)acrylate polymer additive to improve the low temperature viscosity of an industrial gear lubricating composition, wherein the industrial gear lubricating composition has the composition of any of clauses 1 to 31.

[00114] Each of the documents referred to above is incorporated herein by reference, including any prior applications, whether or not specifically listed above, from which priority is claimed. The mention of any document is not an admission that such document qualifies as prior art or constitutes the general knowledge of the skilled person in any jurisdiction. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about." 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 technology can be used together with ranges or amounts for any of the other elements.

[00115] As used herein, “substantially free” means that the amount of the material in question is less than an amount that will affect the relevant performance of the fluid in a measurable way. “Substantially free” may also mean that the material in question is not intentionally added to the composition but does not exclude the presence of such material as contaminants. “Substantially free” may also mean that the material in question may be present in amounts lower than the detection limit of standard test methods now known to those skilled in the art or hereafter developed. In some embodiments, “substantially free” may mean less than 10 ppm by weight or even less than 5 ppm by weight.

[00116] As used herein, the transitional term “comprising,” which is synonymous with “including,” “containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, un-recited elements or method steps. However, in each recitation of “comprising” herein, it is intended that the term also encompass, as alternative embodiments, the phrases “consisting essentially of’ and “consisting of,” where “consisting of’ excludes any element or step not specified and “consisting essentially of’ permits the inclusion of additional un-recited elements or steps that do not materially affect the essential or basic and novel characteristics of the composition or method under consideration.

[00117] While certain representative embodiments and details have been shown for the purpose of illustrating the subject technology, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject technology. In this regard, the scope of the technology is to be limited only by the following claims.

Claims

CLAIMS What is claimed is:

1. An industrial gear lubricating composition comprising:

(a) a base oil, wherein the base oil comprises at least 75 weight percent of Group IV base oil;

(b) at least one sulfurized olefin present in an amount to provide at least 1000 ppm sulfur to the composition;

(c) one or more phosphorus-containing agents in an amount to provide at least 100 ppm phosphorus to the composition; and

(d) a poly(meth)acylate polymer, wherein the poly(meth)acrylate polymer comprises at least 10 mol percent of one or more (meth)acrylic acid alkyl ester monomers having an alkyl group containing 16 or more carbon atoms.

2. The composition of claim 1, wherein the poly(meth)acrylate polymer comprises 50 to 90 mol percent of (meth)acrylic acid alkyl ester monomers containing 8 to 15 carbon atoms.

3. The composition of any preceding claim, wherein the poly(meth)acrylate polymer is present in an amount 0.05 to 0.5 weight percent of the composition.

4. The composition of any preceding claim, further comprising a branched hydrocarbyl alcohol containing 10 or more carbon atoms.

5. The composition of claim 4, wherein the branched hydrocarbyl alcohol comprises a betabranched alcohol containing 12 or more carbon atoms.

6. The composition of any preceding claim, wherein the base oil comprises at least 85 weight percent of Group IV base oil.

7. The composition of any preceding claim, wherein the base oil is a mixture of Group IV base oils, wherein the mixture comprises one or more polyalphaolefin base oils having a kinematic viscosity between 4 and 10 cSt at 100 °C and one or more polyalphaolefin base oils having a kinematic viscosity greater than 50 cSt at 100 °C.

8. The composition of any preceding claim, wherein the phosphorus-containing agent comprises hydrocarbyl phosphite, hydrocarbyl phosphonate, hydrocarbyl phosphate ester, hydrocarbyl amine salt of di-, or tri-hydrocarbylphosphoric acid, or any combination thereof.

9. The composition of any preceding claim, wherein the sulfurized olefin comprises an olefin containing 4 to 12 carbon atoms.

10. The composition of any preceding claim, wherein the sulfurized olefin comprises sulfurized isobutylene.

11. The composition of any preceding claim, wherein the composition has a kinematic viscosity at 40 °C of at least 150 cSt.

12. A method of lubricating an industrial gear comprising supplying to the gear a lubricating composition of any preceding claim.

13. A method of improving the low temperature viscosity of an industrial gear lubricant, comprising supplying to the gear a lubricating composition of any of claims 1 to 11.

14. The use of a poly(meth)acrylate polymer additive to improve the low temperature viscosity of an industrial gear lubricating composition, wherein the industrial gear lubricating composition has the composition of any of claims 1 to 11.