US20190144776A1

US20190144776A1 - Lubricant grease compositions comprising polymeric diphenylamine antioxidants

Info

Publication number: US20190144776A1
Application number: US16/175,329
Authority: US
Inventors: Liehpao Oscar Famg; Graciela Sanchez Jimenez; Mary DERY; Paul Odorisio; Bridgett RAKESTRAW; Sai Shum; David Khoshabo; Michael L. Alessi; Rebecca Cristine Vieira; Andrew Edmund Taggi
Original assignee: Exxonmobil Research And Engineering Company
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 2017-10-31
Filing date: 2018-10-30
Publication date: 2019-05-16
Also published as: WO2019089724A1

Abstract

Disclosed in certain embodiments is a lubricating grease composition comprising an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I

wherein
R is H, C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, —C(O)C₁-C₁₈alkyl, —C(O)aryl and R₁, R₂, R₃and R₄are each independently H or a linear or branched C₁-C₁₈alkyl, C₁-C₁₈alkoxy, C₁-C₁₈alkylamino, C₁-C₁₈dialkylamino, C₁-C₁₈alkylthio, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl or C₇-C₂₁aralkyl and
wherein
the number average molecular weight (Mn) of the polymer composition is from about 350 g/mol to about 5000 g/mol.

Description

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 62/579,643, filed on Oct. 31, 2017, which is herein incorporated by reference in its entirety.

FIELD

This disclosure relates to grease compositions with improved high temperature bearing performance. In particular, this disclosure relates to greases, methods for improving high temperature performance of a lubricating grease in a bearing or other mechanical component lubricated with the lubricating grease and methods of making and using the same.

BACKGROUND

Lubricant oxidative stability is one of the key parameters controlling oil life, which translates to oil drain interval in practical terms. Additionally, deposit formation is an issue associated with the decomposition of the base stock molecules mostly propagated by oxidative chain reactions. There are several conventional approaches to improve the resistance to oxidation of a finished lubricant product, but most products are formulated using small molecules such as diphenylamine (DPA) or a phenolic antioxidant.
Improved oxidation stability is necessary to increase oil life and oil drain intervals, thus reducing the amount of used oil generated as a consequence of more frequent oil changes. Longer oil life and oil drain intervals are key benefits that are desirable to end customers. Traditional antioxidant packages provide standard protection leaving the main differentiation hinging on the quality of the base stock in the formulation.
What is needed are newly designed lubricants capable of controlling oxidation and oil thickening for longer periods of time as compared to conventional lubricants. Further, what are needed are newly designed lubricants that enable extended oil life in combination with desired deposit control and cleanliness performance.
Lubricating formulations and greases with a wide assortment of different materials are known. For example, lithium complex greases are well known and can be made from any of a wide variety of base stocks of lubricating oil viscosity, as well as mixtures of base stocks. For example, lithium complex greases that comprise a lithium complex thickener and a lubricating base oil are well known. Greases have varied levels of desirable grease characteristics, such as dropping point, penetration, mechanical stability, shear stability, oxidation resistance, high temperature resistance, etc., based on its composition, which may include the use of polymers. The above characteristics are used to describe the lubricating life of a particular grease.
The use of polymers to impart desirable properties to grease is known and widely practiced by grease manufacturers; see, for example, the description of various thickeners in Manufacture and Application of Lubricating Greases (1954), Reinhold, N.Y. 1954 and Alteration of Grease Characteristics with New Generation Polymers, G. D. Hussey, NLGI Spokesman, August 1987. Oil soluble polymers have been used, for example, to increase the structural stability of greases and to confer reduced oil separation, and increased water resistance. Although these benefits could be obtained without polymers by using lubricating oils having high viscosity base stocks, the resulting debit on low temperature mobility (i.e., pumpability) severely limits a non-polymer approach.
Currently, lithium soap based greases represent approximately 80% of the lubricating grease market and generally provide acceptable lubricating performance. However, lithium soap based greases are limited by their resistance to high-temperatures, wet environments, and shear. For example, lithium soap based grease in polyalphaolefin (PAO) based fluid maxes out at 140° C. Currently available high-temperature lithium greases are either composed of solid particles, such as polytetrafluoroethylene (PTFE), which induce wear and tear on the lubricated surface(s) (such as bearings, gears, slide plates, etc.), or polyester (POE) base oils, which are costly, are limited in certain properties and impractical for manufacture.
Polymer additives are well established for enhancing grease performance at low treatment levels as reported in NLGI Paper Benefits of Polymer Additives in Grease, Larson, et al., NLGI Spokesman, ISSN: 00276782, Vol: 73, Issue 7. As discussed in Larson, the challenges facing grease manufacturers face can be addressed with the inclusion of polymer additives in a variety of grease types. The benefits of polymer additives in Larson are shown to include improved shear stability, enhanced water resistance, and increased yield. In addition to performance enhancements, selected polymer additives may provide economic benefits through increased grease yields of up to 17%.
Polymers that have been studied as grease additives include polyisobutylene (PIB), ethylene-propylene copolymers (OCP), styrene-hydrogenated butadiene (SBR), styrene-hydrogenated isoprene (SI), radial hydrogenated polyisoprene (star), acid functionalized polymers (FP), polymethacrylate (PMA), styrene ester copolymers (SE), and styrene ethylene butylene copolymers (SEBCP). These polymers have been used as co-thickeners e.g. with a calcium soap as described in U.S. Pat. No. 5,084,193 (Waynick) or as the sole thickener as in U.S. Pat. No. 5,874,391 (Meijer).
As technology advances and throughput increases with mechanical devices, there is an increased demand for higher temperature operating conditions and lubricating compositions, such as grease The working life of grease is limited in such an environment, which results in greater wear on the equipment and longer downtimes as a result of maintenance (e.g., re-greasing the ball bearings and replacement/maintenance of warn parts of the equipment).
Thus, a need exists for lubricating greases that have enhanced/extended high temperature resistance.

SUMMARY

In certain embodiments, the present disclosure is directed to a lubricating grease composition comprising a base oil, water insoluble thickener and an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I
wherein
R is H, C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, —C(O)C₁-C₁₈alkyl, —C(O)aryl and R₁, R₂, R₃and R₄are each independently H or a linear or branched C₁-C₁₈alkyl, C₁-C₁₈alkoxy, C₁-C₁₈alkylamino, C₁-C₁₈dialkylamino, C₁-C₁₈alkylthio, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl or C₇-C₂₁aralkyl. In certain embodiments, the number average molecular weight (Mn) of the antioxidant polymer (e.g., oligomer) composition is at least about 350 g/mol or from about 350 g/mol to about 5000 g/mol.
Also disclosed in certain embodiments is a lubricating oil composition comprising an antioxidant polymer (e.g., oligomer) composition comprising ≤about 99 wt %, ≤about 90 wt %, ≤about 80 wt %, ≤about 70 wt %, ≤about 65 wt %, ≤about 60 wt %, ≤about 55 wt %, ≤about 50 wt %, ≤about 45 wt %, ≤about 40 wt %, ≤about 35 wt %, ≤about 30 wt %, ≤about 25 wt %, ≤about 20 wt %, ≤about 15 wt %, ≤about 10 wt %, ≤about 5 wt %, ≤about 1 wt %, ≤about 0.5 wt %, ≤about 0.1 wt %, ≤about 0.05 wt % or ≤about 0.01 wt % residual monomers of formula I. For example, in certain embodiments, disclosed is an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I, wherein the composition comprises from any one of about 0.01 wt %, about 0.05 wt %, about 0.1 wt %, about 0.5 wt %, about 1 wt %, about 2 wt %, about 3 wt %, about 4 wt %, about 5 wt %, about 7 wt %, about 9 wt %, ab about 70 wt % out 11 wt % or about 13 wt % to any one of about 15 wt %, about 18 wt %, about 21 wt %, about 24 wt %, about 27 about 70 wt % wt %, about 30 wt %, about 35 wt %, about 40 wt %, about 45 wt %, about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt %, about 70 wt %, about 80 wt % or about 99 wt % residual monomers of formula I, based on the total weight of the antioxidant composition.
In certain embodiments wherein the antioxidant polymer (e.g., oligomer) composition comprises residual monomers, about 90 wt %, about 91 wt %, about 92 wt %, about 93 wt %, about 94 wt % or about 95 wt % to about 96 wt %, about 97 wt %, about 98 wt %, about 99 wt % or 100 wt % of the residual monomer(s) is of formula I wherein one or both of R₁and R₄are independently C₄-C₁₈alkyl, C₄-C₁₈alkenyl or C₇-C₂₁aralkyl, based on the total weight of residual monomer(s).
Also disclosed are lubricating grease compositions comprising a base oil, water insoluble thickener and an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I. The grease composition can be used in many industrial and consumer applications such as lubricating a bearing such as a rolling element bearing, e g. a spherical roller bearing, a taper roller bearing, a cylindrical roller bearing, a needle roller bearing, a ball bearing, and may also be used to lubricate a sliding or plain bearing. The grease composition can also be used in coupling and gearing applications.

DETAILED DESCRIPTION

In certain embodiments, the present disclosure is directed to a lubricating grease composition comprising a base oil, water insoluble thickener and an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I
wherein R is H, C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, —C(O)C₁-C₁₈alkyl, —C(O)aryl; and R₁, R₂, R₃and R₄are each independently H or a linear or branched C₁-C₁₈alkyl, C₁-C₁₈alkoxy, C₁-C₁₈alkylamino, C₁-C₁₈dialkylamino, C₁-C₁₈alkylthio, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl or C₇-C₂₁aralkyl. In certain embodiments, the number average molecular weight (Mn) of the antioxidant polymer (e.g., oligomer) composition is at least about 350 g/mol or from about 350 g/mol to about 5000 g/mol.
In other embodiments, the antioxidant polymer (e.g., oligomer) compositions of the disclosure have an Mn of from about 900 g/mol or about 1000 g/mol to about 1200 g/mol or an Mn of any one of from about 400 g/mol, about 430 g/mol, about 460 g/mol, about 490 g/mol, about 520 g/mol, about 550 g/mol, about 580 g/mol, about 610 g/mol, about 640 g/mol, about 670 g/mol, about 700 g/mol or about 730 g/mol g/mol to any one of about 760 g/mol, about 790 g/mol, about 820 g/mol, about 850 g/mol, about 880 g/mol, about 910 g/mol, about 940 g/mol, about 970 g/mol, about 1000 g/mol, about 1030 g/mol, about 1060 g/mol, about 1090 g/mol, about 1120 g/mol, about 1150 g/mol, about 1180 g/mol, about 1210 g/mol, about 1240 g/mol, about 1270 g/mol, about 1300 g/mol, about 1400 g/mol, about 1500 g/mol, about 1600 g/mol, about 1700 g/mol, about 2000 g/mol, about 2100 g/mol, about 2200 g/mol, about 2300 g/mol, about 2400 g/mol, about 2500 g/mol, about 3000 g/mol, about 3500 g/mol, about 4000 g/mol or about 5000 g/mol.
The number average molecular weight can be determined, for example, by gel permeation chromatography (GPC) techniques with a polystyrene standard. GPC conditions may include testing relative to a set of polystyrene standards (EasiCal PS-1, low and high and PS162). Samples are prepared in tetrahydrofuran (THF) and duplicate injections of solutions are run. Similar conditions may also be employed.
In certain embodiments, less than about 25 percent by weight of the antioxidant composition contains molecules having a molecular weight of less than about 1000 g/mol.
In certain embodiments, the present disclosure is directed to a lubricating grease composition comprising a base oil, water insoluble thickener and an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula II
wherein R and R′ are each independently H or a linear or branched C₁-C₁₈alkyl, C₂-C₁₈alkenyl or C₇-C₂₁aralkyl. In certain embodiments, R and R′ are each independently H, tert-butyl or tert-octyl.
Linear or branched alkyl includes methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1,3-dimethylbutyl, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, tert-octyl, 2-ethylhexyl, 1,1,3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl, dodecyl, 1,1,3,3,5,5-hexamethylhexyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl. Alkyl groups mentioned herein are linear or branched.
The alkyl portion of alkoxy, alkylamine, dialkylamino and alkylthio groups are linear or branched and include the alkyl groups mentioned above.
Alkenyl is an unsaturated alkyl, for instance allyl. Alkynyl includes a triple bond.
Aralkyl includes benzyl, α-methylbenzyl, α,α-dimethylbenzyl and 2-phenylethyl.
Diphenylamine antioxidants are commercially available, for example under the trade names IRGANOX L57, IRGANOX L67 and IRGANOX L01.
In certain embodiments, the antioxidant polymer (e.g., oligomer) compositions of the disclosure can be prepared by a process comprising subjecting diphenylamine monomers of formula I
wherein R is H, C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, —C(O)C₁-C₁₈alkyl, —C(O)aryl; and R₁, R₂, R₃and R₄are each independently H or a linear or branched C₁-C₁₈alkyl, C₁-C₁₈alkoxy, C₁-C₁₈alkylamino, C₁-C₁₈dialkylamino, C₁-C₁₈alkylthio, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl or C₇-C₂₁aralkyl to dehydrocondensation conditions.
Dehydrocondensation conditions comprise exposing monomers of formula I to oxidative conditions, for example, by exposure to a compound capable of forming free radicals. Compounds capable of forming free radicals include inorganic and organic peroxides, such as di-t-butylperoxide and di-t-amylperoxide. The dehydrocondensation reaction may be performed neat, that is, without added solvent, or may be performed in the presence of a solvent. Suitable solvents include alkanes such as hexane, heptane, octane, nonane, decane, undecane or dodecane. Dehydrocondensation may be performed in the presence of a base stock (e.g., ester, mineral, synthetic, GTL or alkyl naphthalene base stocks).
In some embodiments, the dehydrocondensation conditions comprise reaction temperatures of any one of from about 40° C., about 60° C., about 80° C., about 100° C., about 120° C., about 140° C. or about 160° C. to any one of about 180° C., about 200° C., about 220° C., about 240° C. or about 250° C.
In certain embodiments, the dehydrocondensation conditions comprise a reaction time of any one of from about 0.3 hours, about 0.5 hour, about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours or about 6 hours to any one of about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours or about 12 hours. In other embodiments, the dehydrocondensation conditions may comprise a reaction time of from any one of about 12 hours, about 24 hours, about 36 hours, about 48 hours or about 60 hours to any one of about 72 hours, about 84 hours, about 96 hours, about 108 hours or about 120 hours.
The oxidative conditions remove hydrogen from the monomers, which subsequently couple through C—N, C—C or N—N bonds. When an alkane solvent is used, the solvent appears to be inert and to not be involved in the reaction. Therefore, the produced antioxidant polymer (e.g., oligomer) may contain no alkane solvent fragments.
The term “oligomer comprising repeat units of diphenylamine monomers” means the oligomers contain “reacted in” monomers, that is, radicals of monomers.
The antioxidant polymer (e.g., oligomer) compositions of the present disclosure may contain a mixture of different chain lengths. For example, the composition may contain residual unreacted monomer as well as fragments or chains having molecular weights above or below the ranges mentioned above. Residual monomer means unreacted monomer. The antioxidant polymer (e.g., oligomer) may be purified, for example by a step comprising chromatography or distillation. In one embodiment, the produced antioxidant polymer (e.g., oligomer) composition may be subject to reduced pressure to remove residual monomer.
Accordingly, the antioxidant polymer (e.g., oligomer) composition of the present disclosure may contain ≤about 99 wt %, ≤about 90 wt %, ≤about 80 wt %, ≤about 70 wt %, ≤about 65 wt %, ≤about 60 wt %, ≤about 55 wt %, ≤about 50 wt %, ≤about 45 wt %, ≤about 40 wt %, ≤about 35 wt %, ≤about 30 wt %, ≤about 25 wt %, ≤about 20 wt %, ≤about 15 wt %, ≤about 10 wt % ≤about 5 wt %, ≤about 1 wt %, ≤about 0.5 wt %, ≤about 0.1 wt %, ≤about 0.05 wt % or ≤about 0.01 wt % residual monomers of formula I, based on the weight of the composition. For example, in certain embodiments, disclosed is an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I, wherein the composition comprises from any one of about 0.01 wt %, about 0.05 wt %, about 0.1 wt %, about 0.5 wt %, about 1 wt %, about 2 wt %, about 3 wt %, about 4 wt %, about 5 wt %, about 7 wt %, about 9 wt %, about 11 wt % or about 13 wt % to any one of about 15 wt %, about 18 wt %, about 21 wt %, about 24 wt %, about 27 wt %, about 30 wt %, about 35 wt %, about 40 wt %, about 45 wt %, about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt % about 70 wt %, about 80 wt % or about 99 wt % residual monomers of formula I, based on the total weight of the antioxidant composition.
In certain embodiments, the purification steps to remove residual monomers include subjecting the antioxidant polymer (e.g., oligomer) composition to reduced pressure. In certain embodiments, the remaining monomer in the composition will include higher molecular weight monomers, e.g., di- or tri-alkyl substituted monomers. In some embodiments, wherein the antioxidant polymer (e.g., oligomer) composition contains residual monomer, any one of from about 90 wt %, about 91 wt %, about 92 wt %, about 93 wt %, about 94 wt % or about 95 wt % to any one of about 96 wt %, about 97, about 98, about 99 or 100 wt % of the residual monomer is of formula I wherein R₁and R₄are independently C₄-C₁₈alkyl, C₄-C₁₈alkenyl or C₇-C₂₁aralkyl, based on the total weight of residual monomer.
In certain embodiments, the antioxidant polymer (e.g., oligomer) composition may also be characterized by its viscosity. For example, the present antioxidant polymer (e.g., oligomer) compositions of the disclosure may have a kinematic viscosity at 100° C. of from any one of about 10 cSt to about 2,500 cSt. In other embodiments, the kinematic viscosity at 100° C. may be from any one of about 10 cSt, about 20 cSt, about 30 cSt, about 40 cSt, about 50 cSt, about 60 cSt, about 70 cSt, about 80 cSt, about 81 cSt, about 82 cSt, about 83 cSt, about 84 cSt, about 85 cSt, about 86 cSt, about 87 cSt, about 88 cSt, about 89 cSt, about 90 cSt, about 91 cSt, about 92 cSt, about 93 cSt, about 94 cSt, about 95 cSt, about 96 cSt, about 97 cSt, about 98 cSt or about 99 cSt to any one of about 100 cSt, about 101 cSt, about 102 cSt, about 103 cSt, about 104 cSt, about 105 cSt, about 106 cSt, about 107 cSt, about 108 cSt, about 109 cSt, about 110 cSt, about 111 cSt, about 112 cSt, about 113 cSt, about 114 cSt, about 115 cSt, about 116 cSt, about 117 cSt, about 118 cSt, about 119 cSt, about 120 cSt, about 500 cSt, about 1,000 cSt, about 1,500 cSt, about 2,000 cSt or about 2,500 cSt.
In certain other embodiments of the disclosure, the antioxidant polymer (e.g., oligomer) compositions may have a kinematic viscosity 100° C. of from any one of about 120 cSt, about 140 cSt, about 170 cSt, about 190 cSt, about 210 cSt, about 230 cSt, about 260 cSt, about 310 cSt or about 360 cSt to any one of about 400 cSt, about 420 cSt, about 450 cSt, about 470 cSt, about 500 cSt, about 530 cSt, about 570 cSt or about 600 cSt. In certain other embodiments, the antioxidant polymer (e.g., oligomer) compositions may be solids.
Viscosity may be determined according to ASTM D445 or equivalent or similar methods measured at 100° C.
In certain embodiments, further monomers may be included in the polymerization reaction. For example, present antioxidant polymer (e.g., oligomer)s may contain one or more monomers selected from the group consisting of other diphenylamines, phenothiazines, phenoxazines, aminodiphenylamines, methylenedianiline, toluenediamine, aminophenols, alkylphenols, thiophenols, phenylenediamines, quinolines, phenyl pyridinediamines, pyridinepyrimidinediamines, naphthylphenylamines and phenylpyrimidinediamines.
In some embodiments, present antioxidant polymer (e.g., oligomer) compositions comprise any one of from about 1 mol %, 10 mol %, about 20 mol %, about 30 mol %, about 40 mol % or about 50 mol % to any one of about 60 mol %, about 70 mol %, about 80 mol %, about 90 mol %, about 95 mol %, about 96 mol %, about 97 mol %, about 98 mol %, about 99 mol % or 100 mol % diphenylamine monomers of formula I.
In certain embodiments, the polymeric compositions disclosed herein are oligomeric compositions (i.e., dimers, trimers and tetramers).
In certain embodiments, the polymeric compositions disclosed herein comprise one or more of dimers, trimers, tetramers or higher repeating units (i.e. a antioxidant polymer of 5 or more monomers).
In certain embodiments, the polymeric compositions have an amount of dimers that are greater than the amount of higher repeating units.
In certain embodiments, the polymeric compositions have an amount of trimers that are greater than the amount of higher repeating units.
In certain embodiments, the polymeric compositions have a combined amount of dimers and trimers that are greater than the amount of higher repeating units.
In certain embodiments, the polymeric compositions have at least 75% Mn of greater than 1000. In other embodiments, the polymeric compositions have about 20% to about 80%, about 25% to about 75%, about 30% to about 70% or about 40% to about 60% Mn of greater than 1000.
In certain embodiments, the polymeric compositions have at least 75% Mn of less than 1000. In other embodiments, the polymeric compositions have about 10% to about 100%, about 20% to about 80%, about 25% to about 75%, about 30% to about 70% or about 40% to about 60% Mn of less than 1000.
In certain embodiments, the polymeric compositions have an amount of dimers of from any one of about 5%, about 10%, about 15%, about 20%, about 25% or about 30% to any one of about 40%, about 45%, about 50%, about 55%, about 60%, about 70%, about 80%, about 90% or about 100%. In certain embodiments, the dimers have a number average molecular weight (Mn) of about 300 to about 850.
In certain embodiments, the polymeric compositions have an amount of trimers of from any one of about 10%, about 15%, about 20%, about 25%, about 30% or about 40% to any one of about 50%, about 55%, about 60%, about 65%, about 70%, about 80%, about 90% or about 100%. In certain embodiments, the trimers have a number average molecular weight (Mn) of about 400 to about 1200.
In certain embodiments, the polymeric compositions have an amount of tetramers of from any one of about 15%, about 20%, about 25%, about 30%, about 40% or about 50% to any one of about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 90% or about 100%. In certain embodiments, the tetramers have a number average molecular weight (Mn) of about 500 to about 1500.
In certain embodiments, the polymeric compositions have an amount of higher repeating units of from any one of about 5%, about 10%, about 25%, about 30%, about 40% to any one of about 50%, about 60%, about 70%, about 80%, about 90% or about 100%. In certain embodiments, the higher repeating units have a number average molecular weight (Mn) of greater than about 1000 or greater than about 1174.
In certain embodiments polymeric composition have m/z ions ranging from 300 to 1000. In certain embodiments, the above m/z ions include 838 Daltons, 894 Daltons or 911 Daltons.
In certain embodiments, the polymeric compositions have an m/z ion count from about 300 to about 1,000 of greater than about 50, greater than about 75, greater than about 100, greater than about 150, greater than about 200, greater than about 250, greater than about 300 or greater than about 350. In certain embodiments, the polymeric compositions have an m/z ion count from about 800 to about 1,000 of from any one of about 50, about 75, about 100 or about 150 to any one of about 200, about 250, about 300 or about 350.
In certain embodiments, the polymeric compositions exhibit a VIT(h) of greater than about 600, greater than about 650, greater than about 700, or greater than about 850. In certain embodiments, the polymeric compositions exhibit a VIT(h) of from any one of about 600, about 650, or about 700 to any one of about 900, about 1,200 or about 1,500. A comparator monomer composition provides a VIT(h) of 472. The VIT test is performed by placing a sample of formulated oil in a glass tube with a homogeneous catalyst consisting of iron, copper and lead. Air is bubbled through the sample at a rate of 8 L/h and heated to 150° C. The kinematic viscosity (KV40) is monitored throughout the test, and the data fit to a power curve to calculate the time, in hours, it takes for the sample to reach 150% of its original KV40.
In certain embodiments, disclosed is a grease formulation that provides a value of greater than 100, greater than 110 or greater than 120 when tested according to DIN 51821 FE9 A/1500/6000 @ 140 C (B50, hours) when the grease formulation comprises 1% of the disclosed antioxidant polymer composition.
The water insoluble thickener, as discussed below, may comprise at least one of an aluminum soap, a barium soap, a calcium soap, a lithium soap, an aluminum salt/soap complex, a barium salt/soap complex, a calcium salt/soap complex, a lithium salt/soap complex, or a combination thereof. In certain embodiments, the water insoluble thickener comprises lithium soap or a lithium salt/soap complex. In a particular embodiment, the water insoluble thickener comprises an inorganic clay thickener.
A wide range of lubricating base oils is known in the art. Lubricating base oils that may be useful in the present disclosure are both natural oils, and synthetic oils, and unconventional oils (or mixtures thereof) can be used unrefined, refined, or rerefined (the latter is also known as reclaimed or reprocessed oil). Unrefined oils are those obtained directly from a natural or synthetic source and used without added purification. These include shale oil obtained directly from retorting operations, petroleum oil obtained directly from primary distillation, and ester oil obtained directly from an esterification process. Refined oils are similar to the oils discussed for unrefined oils except refined oils are subjected to one or more purification steps to improve at least one lubricating oil property. One skilled in the art is familiar with many purification processes. These processes include solvent extraction, secondary distillation, acid extraction, base extraction, filtration, and percolation. Rerefined oils are obtained by processes analogous to refined oils but using an oil that has been previously used as a feed stock.
Groups I, II, III, IV and V are broad base oil stock categories developed and defined by the American Petroleum Institute (API Publication 1509; www.API.org to create guidelines for lubricant base oils. Group I base stocks have a viscosity index of from 80 to 120 and contain greater than 0.03% sulfur and/or less than 90% saturates. Group II base stocks have a viscosity index of from 80 to 120, and contain less than or equal to 0.03% sulfur and greater than or equal to 90% saturates. Group III stocks have a viscosity index greater than 120 and contain less than or equal to 0.03% sulfur and greater than 90% saturates. Group IV includes polyalphaolefins (PAO). Group V base stock includes base stocks not included in Groups I-IV. The table below summarizes properties of each of these five groups.


	saturates	sulfur	viscosity index

Group I	<90 and/or	>0.03% and	≥80 and <120
Group II	≥90 and	≤0.03% and	≥80 and <120
Group III	≥90 and	≤0.03% and	≥120

Group IV	-polyalphaolefins (PAO)-
Group V	-all other base stocks not of Groups I-IV-

Natural oils include animal oils, vegetable oils (castor oil and lard oil, for example), and mineral oils. Animal and vegetable oils possessing favorable thermal oxidative stability can be used. Of the natural oils, mineral oils are preferred. Mineral oils vary widely as to their crude source, for example, as to whether they are paraffinic, naphthenic, or mixed paraffinic-naphthenic. Oils derived from coal or shale are also useful. Natural oils vary also as to the method used for their production and purification, for example, their distillation range and whether they are straight run or cracked, hydrorefined, or solvent extracted.
Group II and/or Group III hydroprocessed or hydrocracked base stocks, including synthetic oils such as polyalphaolefins, alkyl aromatics and synthetic esters are also well known base stock oils.
Synthetic oils include hydrocarbon oil. Hydrocarbon oils include oils such as polymerized and interpolymerized olefins (polybutylenes, polypropylenes, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylene-alphaolefin copolymers, for example). Polyalphaolefin (PAO) oil base stocks are commonly used synthetic hydrocarbon oil. By way of example, PAOs derived from C₆, C₈, C₁₀, C₁₂, C₁₄olefins or mixtures thereof may be utilized. See U.S. Pat. Nos. 4,956,122; 4,827,064; and 4,827,073.
The number average molecular weights of the PAOs, which are known materials and generally available on a major commercial scale from suppliers such as ExxonMobil Chemical Company, Chevron Phillips Chemical Company, BP, and others, typically vary from 250 to 3,000, although PAO's may be made in viscosities up to 100 cSt (100° C.). The PAOs are typically comprised of relatively low molecular weight hydrogenated polymers or oligomers of alphaolefins which include, but are not limited to, C₂to C₃₂alphaolefins with the C₈to C₁₆alphaolefins, such as 1-hexene, 1-octene, 1-decene, 1-dodecene and the like, being preferred. The preferred polyalphaolefins are poly-1-hexene, poly-1-octene, poly-1-decene and poly-1-dodecene and mixtures thereof and mixed olefin-derived polyolefins. However, the dimers of higher olefins in the range of C₁₄to C₁₈may be used to provide low viscosity base stocks of acceptably low volatility. Depending on the viscosity grade and the starting polymer (e.g., oligomer), the PAOs may be predominantly trimers and tetramers of the starting olefins, with minor amounts of the higher polymers, having a viscosity range of 1.5 to 12 cSt. PAO fluids of particular use may include 3.0 cSt, 3.4 cSt, and/or 3.6 cSt and combinations thereof. Bi-modal mixtures of PAO fluids having a viscosity range of 1.5 to about 100 cSt or to about 300 cSt may be used if desired.
The PAO fluids may be conveniently made by the polymerization of an alphaolefin in the presence of a polymerization catalyst such as the Friedel-Crafts catalysts including, for example, aluminum trichloride, boron trifluoride or complexes of boron trifluoride with water, alcohols such as ethanol, propanol or butanol, carboxylic acids or esters such as ethyl acetate or ethyl propionate. For example the methods disclosed by U.S. Pat. No. 4,149,178 or 3,382,291 may be conveniently used herein. Other descriptions of PAO synthesis are found in the following U.S. Pat. Nos. 3,742,082; 3,769,363; 3,876,720; 4,239,930; 4,367,352; 4,413,156; 4,434,408; 4,910,355; 4,956,122; and 5,068,487. The dimers of the C₁₄to C₁₈olefins are described in U.S. Pat. No. 4,218,330.
Other useful lubricant oil base stocks include wax isomerate base stocks and base oils, comprising hydroisomerized waxy stocks (e.g. waxy stocks such as gas oils, slack waxes, fuels hydrocracker bottoms, etc.), hydroisomerized Fischer-Tropsch waxes, Gas-to-Liquids (GTL) base stocks and base oils, and other wax isomerate hydroisomerized base stocks and base oils, or mixtures thereof Fischer-Tropsch waxes, the high boiling point residues of Fischer-Tropsch synthesis, are highly paraffinic hydrocarbons with very low sulfur content. The hydroprocessing used for the production of such base stocks may use an amorphous hydrocracking/hydroisomerization catalyst, such as one of the specialized lube hydrocracking (LHDC) catalysts or a crystalline hydrocracking/hydroisomerization catalyst, preferably a zeolitic catalyst. For example, one useful catalyst is ZSM-48 as described in U.S. Pat. No. 5,075,269, the disclosure of which is incorporated herein by reference in its entirety. Processes for making hydrocracked/hydroisomerized distillates and hydrocracked/hydroisomerized waxes are described, for example, in U.S. Pat. Nos. 2,817,693; 4,975,177; 4,921,594 and 4,897,178 as well as in British Patent Nos. 1,429,494; 1,350,257; 1,440,230 and 1,390,359. Each of the aforementioned patents is incorporated herein in their entirety. Particularly favorable processes are described in European Patent Application Nos. 464546 and 464547, also incorporated herein by reference. Processes using Fischer-Tropsch wax feeds are described in U.S. Pat. Nos. 4,594,172 and 4,943,672, the disclosures of which are incorporated herein by reference in their entirety.
Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils, and other wax-derived hydroisomerized (wax isomerate) base oils be advantageously used in the instant disclosure, and may have useful kinematic viscosities at 100° C. of 3 cSt to 50 cSt, preferably 3 cSt to 30 cSt, more preferably 3.5 cSt to 25 cSt, as exemplified by GTL 4 with kinematic viscosity of 4.0 cSt at 100° C. and a viscosity index of 141. These Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils, and other wax-derived hydroisomerized base oils may have useful pour points of −20° C. or lower, and under some conditions may have advantageous pour points of −25° C. or lower, with useful pour points of −30° C. to −40° C. or lower. Useful compositions of Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils, and wax-derived hydroisomerized base oils are recited in U.S. Pat. Nos. 6,080,301; 6,090,989, and 6,165,949 for example, and are incorporated herein in their entirety by reference.
The hydrocarbyl aromatics can be used as base oil or base oil component and can be any hydrocarbyl molecule that contains at least 5% of its weight derived from an aromatic moiety such as a benzenoid moiety or naphthenoid moiety, or their derivatives. These hydrocarbyl aromatics include alkyl benzenes, alkyl naphthalenes, alkyl diphenyl oxides, alkyl naphthols, alkyl diphenyl sulfides, alkylated bis-phenol A, alkylated thiodiphenol, and the like. The aromatic can be mono-alkylated, dialkylated, polyalkylated, and the like. The aromatic can be mono- or poly-functionalized. The hydrocarbyl groups can also be comprised of mixtures of alkyl groups, alkenyl groups, alkynyl, cycloalkyl groups, cycloalkenyl groups and other related hydrocarbyl groups. The hydrocarbyl groups can range from C₆up to C₆₀with a range of C₈to C₂₀often being preferred. A mixture of hydrocarbyl groups is often preferred, and up to three such substituents may be present.
The hydrocarbyl group can optionally contain sulfur, oxygen, and/or nitrogen containing substituents. The aromatic group can also be derived from natural (petroleum) sources, provided at least 5% of the molecule is comprised of an above-type aromatic moiety. Viscosities at 100° C. of about 3 cSt to about 50 cSt are preferred, with viscosities of about 3.4 cSt to about 20 cSt often being more preferred for the hydrocarbyl aromatic component. In one embodiment, an alkyl naphthalene where the alkyl group is primarily comprised of 1-hexadecene is used. Other alkylates of aromatics can be advantageously used. Naphthalene or methyl naphthalene, for example, can be alkylated with olefins such as octene, decene, dodecene, tetradecene or higher, mixtures of similar olefins, and the like. Useful concentrations of hydrocarbyl aromatic in a lubricant oil composition can be 2% to 25%, preferably 4% to 20%, and more preferably 4% to 15%, depending on the application.
Alkylated aromatics such as the hydrocarbyl aromatics of the present disclosure may be produced by well-known Friedel-Crafts alkylation of aromatic compounds. See Friedel-Crafts and Related Reactions, Olah, G. A. (ed.), Inter-science Publishers, New York, 1963. For example, an aromatic compound, such as benzene or naphthalene, is alkylated by an olefin, alkyl halide or alcohol in the presence of a Friedel-Crafts catalyst. See Friedel-Crafts and Related Reactions, Vol. 2, part 1, chapters 14, 17, and 18, See Olah, G. A. (ed.), Inter-science Publishers, New York, 1964. Many homogeneous or heterogeneous, solid catalysts are known to one skilled in the art. The choice of catalyst depends on the reactivity of the starting materials and product quality requirements. For example, strong acids such as AlCl₃, BF₃, or HF may be used. In some cases, milder catalysts such as FeCl₃or SnCl₄are preferred. Newer alkylation technology uses zeolites or solid super acids.
Esters comprise a useful base stock. Additive solvency and seal compatibility characteristics may be secured by the use of esters such as the esters of dibasic acids with monoalkanols and the polyol esters of monocarboxylic acids. Esters of the former type include, for example, the esters of dicarboxylic acids such as phthalic acid, succinic acid, alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acid, alkenyl malonic acid, etc., with a variety of alcohols such as butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, etc. Specific examples of these types of esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, etc.
Particularly useful synthetic esters may be those which are obtained by reacting one or more polyhydric alcohols, preferably the hindered polyols (such as the neopentyl polyols, e.g., neopentyl glycol, trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol propane, pentaerythritol and dipentaerythritol) with alkanoic acids containing at least 4 carbon atoms, preferably C₅to C₃₀acids such as saturated straight chain fatty acids including caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachic acid, and behenic acid, or the corresponding branched chain fatty acids or unsaturated fatty acids such as oleic acid, or mixtures of any of these materials.
Suitable synthetic ester components include the esters of trimethylol propane, trimethylol butane, trimethylol ethane, pentaerythritol and/or dipentaerythritol with one or more monocarboxylic acids containing from 5 to 10 carbon atoms. These esters are widely available commercially, for example, the Mobil P-41 and P-51 esters of ExxonMobil Chemical Company.
Also useful are esters derived from renewable material such as coconut, palm, rapeseed, soy, sunflower and the like. These esters may be monoesters, di-esters, polyol esters, complex esters, or mixtures thereof. These esters are widely available commercially, for example, the Mobil P-51 ester of ExxonMobil Chemical Company.
Other useful fluids of lubricating viscosity include non-conventional or unconventional base stocks that have been processed, preferably catalytically, or synthesized to provide high performance lubrication characteristics.
Non-conventional or unconventional base stocks/base oils include one or more of a mixture of base stock(s) derived from one or more Gas-to-Liquids (GTL) materials, as well as isomerate/isodewaxate base stock(s) derived from natural wax or waxy feeds, mineral and or non-mineral oil waxy feed stocks such as slack waxes, natural waxes, and waxy stocks such as gas oils, waxy fuels hydrocracker bottoms, waxy raffinate, hydrocrackate, thermal crackates, or other mineral, mineral oil, or even non-petroleum oil derived waxy materials such as waxy materials received from coal liquefaction or shale oil, and mixtures of such base stocks.
GTL materials are materials that are derived via one or more synthesis, combination, transformation, rearrangement, and/or degradation/deconstructive processes from gaseous carbon-containing compounds, hydrogen-containing compounds and/or elements as feed stocks such as hydrogen, carbon dioxide, carbon monoxide, water, methane, ethane, ethylene, acetylene, propane, propylene, propyne, butane, butylenes, and butynes. GTL base stocks and/or base oils are GTL materials of lubricating viscosity that are generally derived from hydrocarbons; for example, waxy synthesized hydrocarbons, that are themselves derived from simpler gaseous carbon-containing compounds, hydrogen-containing compounds and/or elements as feed stocks. GTL base stock(s) and/or base oil(s) include oils boiling in the lube oil boiling range (1) separated/fractionated from synthesized GTL materials such as, for example, by distillation and subsequently subjected to a final wax processing step which involves either or both of a catalytic dewaxing process, or a solvent dewaxing process, to produce lube oils of reduced/low pour point; (2) synthesized wax isomerates, comprising, for example, hydrodewaxed or hydroisomerized cat and/or solvent dewaxed synthesized wax or waxy hydrocarbons; (3) hydrodewaxed or hydroisomerized cat and/or solvent dewaxed Fischer-Tropsch (F-T) material (i.e., hydrocarbons, waxy hydrocarbons, waxes and possible analogous oxygenates); preferably hydrodewaxed or hydroisomerized/followed by cat and/or solvent dewaxing dewaxed F-T waxy hydrocarbons, or hydrodewaxed or hydroisomerized/followed by cat (or solvent) dewaxing dewaxed, F-T waxes, or mixtures thereof.
GTL base stock(s) and/or base oil(s) derived from GTL materials, especially, hydrodewaxed or hydroisomerized/followed by cat and/or solvent dewaxed wax or waxy feed, preferably F-T material derived base stock(s) and/or base oil(s), are characterized typically as having kinematic viscosities at 100° C. of from 2 mm²/s to 50 mm²/s (ASTM D445). They are further characterized typically as having pour points of −5° C. to −40° C. or lower (ASTM D97). They are also characterized typically as having viscosity indices of 80 to 140 or greater (ASTM D2270).
In addition, the GTL base stock(s) and/or base oil(s) are typically highly paraffinic (>90% saturates), and may contain mixtures of monocycloparaffins and multicycloparaffins in combination with non-cyclic isoparaffins. The ratio of the naphthenic (i.e., cycloparaffin) content in such combinations varies with the catalyst and temperature used. Further, GTL base stock(s) and/or base oil(s) typically have very low sulfur and nitrogen content, generally containing less than 10 ppm, and more typically less than 5 ppm of each of these elements. The sulfur and nitrogen content of GTL base stock(s) and/or base oil(s) obtained from F-T material, especially F-T wax, is essentially nil. In addition, the absence of phosphorous and aromatics make this materially especially suitable for the formulation of low SAP products.
The term GTL base stock and/or base oil and/or wax isomerate base stock and/or base oil is to be understood as embracing individual fractions of such materials of wide viscosity range as recovered in the production process, mixtures of two or more of such fractions, as well as mixtures of one or two or more low viscosity fractions with one, two or more higher viscosity fractions to produce a blend wherein the blend exhibits a target kinematic viscosity.
The GTL material, from which the GTL base stock(s) and/or base oil(s) is/are derived is preferably an F-T material (i.e., hydrocarbons, waxy hydrocarbons, wax).
In addition, the GTL base stock(s) and/or base oil(s) are typically highly paraffinic (>90% saturates), and may contain mixtures of monocycloparaffins and multicycloparaffins in combination with non-cyclic isoparaffins. The ratio of the naphthenic (i.e., cycloparaffin) content in such combinations varies with the catalyst and temperature used. Further, GTL base stock(s) and/or base oil(s) and hydrodewaxed, or hydroisomerized/cat (and/or solvent) dewaxed base stock(s) and/or base oil(s) typically have very low sulfur and nitrogen content, generally containing less than 10 ppm, and more typically less than 5 ppm of each of these elements. The sulfur and nitrogen content of GTL base stock(s) and/or base oil(s) obtained from F-T material, especially F-T wax, is essentially nil. In addition, the absence of phosphorous and aromatics make this material especially suitable for the formulation of low sulfur, sulfated ash, and phosphorus (low SAP) products.
Base oils for use in the formulated lubricating greases useful in the present disclosure are any of the variety of oils corresponding to API Group I, Group II, Group III, Group IV, and Group V oils and mixtures thereof, preferably API Group II, Group III, Group IV, and Group V oils and mixtures thereof, more preferably the Group III to Group V base oils due to their exceptional volatility, stability, viscometric and cleanliness features. Minor quantities of Group I stock, such as the amount used to dilute additives for blending into formulated lube oil products, can be tolerated but should be kept to a minimum, i.e. amounts only associated with their use as diluent/carrier oil for additives used on an “as-received” basis. Even in regard to the Group II stocks, it is preferred that the Group II stock be in the higher quality range associated with that stock, i.e. a Group II stock having a viscosity index in the range 100<VI<120.
The lubricating base oil or base stock constitutes the major component of the grease lubricant composition of the present disclosure. One particularly preferred lubricating oil base stock for the inventive lubricating grease and the inventive method for improving high temperature bearing performance is a Group I base stock that is included in the formulated oil at from 75 to 95 wt %, or from 80 to 90 wt %, or from 82 to 88 wt %. Another particularly preferred lubricating oil base stock for the inventive lubricating engine oil and the inventive method for improving fuel efficiency, frictional properties and deposit control is a combination of a Group III, Group IV and Group V base stock wherein the combination is included in the formulated oil at from 75 to 95 wt %, or from 80 to 90 wt %, or from 82 to 88 wt %. In this form, the Group III base stock is included at from 30 to 35 wt % or from 32 to 33 wt %, the Group IV base stock at from 45 to 55 wt % or from 48 to 52 wt %, and the Group V base stock at from 0 to 5 wt %, or from 2 to 4 wt %.
Preferred Group III base stocks are GTL and Yubase Plus (hydroprocessed base stock). Preferred Group V base stocks include alkylated naphthalene, synthetic esters and combinations thereof.
Lubricating oils and base stocks are disclosed for example In US. Pub. Nos. 20170211007, 20150344805 and 2015322367.
Grease Thickener
The compositions of the present disclosure may include a thickener (e.g., a water-insoluble thickener) in a range from about 0.5 to about 20 wt. % (e.g., about 0.5 to about 10 wt. %. For example, the grease composition of the present disclosure may have thickener present in an amount of about 0.5 wt. % to about 20 wt. %, about 0.5 wt. % to about 17.5 wt. %, about 0.5 wt. % to about 15 wt. %, about 0.5 wt. % to about 12.5 wt. %, about 0.5 wt. % to about 10 wt. %, about 0.5 wt. % to about 7.5 wt. %, about 0.5 wt. % to about 5 wt. %, about 1 wt. % to about 20 wt. %, about 1 wt. % to about 17.5 wt. %, about 1 wt. % to about 15 wt. %, about 1 wt. % to about 12.5 wt. %, about 1 wt. % to about 10 wt. %, about 1 wt. % to about 7.5 wt. %, about 1 wt. % to about 5 wt. %, about 2.5 wt. % to about 20 wt. %, about 2.5 wt. % to about 17.5 wt. %, about 2.5 wt. % to about 15 wt. %, about 2.5 wt. % to about 12.5 wt. %, about 2.5 wt. % to about 10 wt. %, about 2.5 wt. % to about 7.5 wt. %, about 5 wt. % to about 20 wt. %, about 5 wt. % to about 17.5 wt. %, about 5 wt. % to about 15 wt. %, about 5 wt. % to about 12.5 wt. %, about 5 wt. % to about 10 wt. %, about 7.5 wt. % to about 20 wt. %, about 7.5 wt. % to about 17.5 wt. %, about 7.5 wt. % to about 15 wt. %, about 7.5 wt. % to about 12.5 wt. %, about 10 wt. % to about 20 wt. %, about 10 wt. % to about 17.5 wt. %, about 10 wt. % to about 15 wt. %, about 12.5 wt. % to about 20 wt. %, about 12.5 wt. % to about 17.5 wt. %, or about 15 wt. % to about 20 wt. %.
The grease will contain an essentially water- and oil-insoluble thickener to provide the desired grease consistency and structure (cone penetration, dropping point, etc.). Thickeners may be of the soap or non-soap types. Non-soaps are based on organic or non-organic solids such as bentonite clay, polymers such as the polyureas or silica aerogels and may be used where their particular properties so indicate. For example, thickeners for the present greases are the metal salt/soap thickeners, including the complex soap thickeners based on metals including aluminum, barium, calcium, lithium, sodium. These types of thickeners are well established and are described in numerous publications. See, for example, Boner op cit, Lubricants and Related Products, Klamann, Verlag Chemie, 1984, ISBN 3-527-26022-6, ISBN 0-89573-177-0 to which reference is made for a description of suitable thickeners and the manufacture of grease incorporating them.
Complex grease thickeners are made by combining the conventional metallic soaps with a complexing agent. The soaps may be a metal salt of a long chain fatty acid having from 8 to 24 carbon atoms such as decanoic acid, myristic acid, palmitic acid or stearic acid. The thickener may be a lithium or lithium complex thickener that incorporates a hydroxy fatty acid having from 12 to 24 (e.g., from 16 to 20) carbon atoms. For example, the hydroxy fatty acid may be an hydroxy stearic acid, e.g., 9-hydroxy or 10-hydroxy stearic acid, or 12-hydroxy stearic acid. Other hydroxyl fatty acids which may be used include ricinoleic acid (12-hydroxystearic acid unsaturated at the 9,10 position), 12-hydroxybehenic acid and 10-hydroxypalmitic acid. The complex salt/soap thickeners are made with a combination of conventional lithium soap such as lithium 12-hydroxystearate and a complexing agent which may vary with the type of thickener, e.g. calcium complex thickeners may be formulated with acetic acid and hydroxy-substituted acids; boric acid may be used with lithium soaps. Low molecular-weight organic acid, typically C₄to C₁₂dibasic acids such as glutaric, azelaic, pimelic, suberic, adipic or sebacic acids, are generally favored as the complexing agents with lithium greases. The complexes are formed by the introduction of the complexing agent or its metal salt into the lattice of the metal salt. Examples of metal salt/soap complex thickeners are described in U.S. Pat. Nos. 3,929,651; 3,940,339; 4,410,435; 4,444,669 and 5,731,274. The complexing agent may be added as the free acid, a salt e.g., the lithium salt or as an ester such as an alkyl ester, e.g. methyl glutarate or methyl adipate, which will undergo hydrolysis to the acid in the presence of the added alkali, e.g. lithium hydroxide, to form the complexing agent. PAO bases may require a higher proportion of thickener than mineral oil base stocks.
The lithium complex thickener used in the grease of the present disclosure is not particularly limited and can be any lithium complex thickener that is known or that becomes known. For example, the lithium complex thickener can comprise a lithium soap derived from a fatty acid having: (a) (i) at least one of an epoxy group, ethylenic unsaturation, or a combination thereof, and (ii) a dilithium salt derived from a straight chain dicarboxylic acid; and/or (b) a lithium salt derived from a hydroxy-substituted carboxylic acid, e.g. salicylic acid.
For example, the lithium complex thickener can comprise at least one of: a complex of a lithium soap of a C₁₂to C₂₄hydroxy fatty acid and a monolithium salt of boric acid; a lithium salt of a second hydroxy carboxylic acid, such as salicylic acid; or a combination thereof.
The lithium complex thickener can comprise a lithium soap of a C₁₂to C₂₄hydroxy fatty acid thickener antioxidant having an alkali metal salt of hydroxy benzoic acid and a diozime compound. In certain embodiments, the alkali metal salt of hydroxy benzoic acid includes dilithium salicylate.
The lithium complex thickener can be a lithium soap comprising at least one of: a dilithium salt of a C₄to C₁₂dicarboxylic acid, e.g., dilithium azelate; a lithium soap of a 9-, 10- or 12-hydroxy C₁₂to C₂₄fatty acid, e.g., lithium 12-hydroxy stearate; and a lithium salt formed in-situ in the grease from a second hydroxy carboxylic acid, wherein the —OH group is attached to a carbon atom not more than 6 carbons removed from the carboxyl group and either of those groups can be attached to aliphatic portions of the materials or aromatic portions of the materials.
In any aspect or embodiment described herein, the lithium complex thickener can comprise a complex lithium thickener and at least one of a lithium salt of a C₃to C₁₄hydroxycarboxylic acid, a thiadiazole, or a combination thereof.
In any aspect or embodiment described herein, the water insoluble thickener may include at least one of an aluminum soap, a barium soap, a calcium soap, a lithium soap, an aluminum salt/soap complex, a barium salt/soap complex, a calcium salt/soap complex, a lithium salt/soap complex, or a combination thereof.
The lubricating greases of the disclosure may contain one or more further additives. Further additives may be present, in each case, from about 0.01 wt %, about 0.1, about 0.5 or about 1 wt % to about 2 wt %, about 5, about 7, about 8, about 10, about 14, about 17, about 20, about 22 or about 25 wt %, based on the total weight of the lubricating grease formulation.
The formulated lubricating grease useful in the present disclosure may additionally contain one or more of the other commonly used lubricant performance additives including but not limited to antiwear agents, dispersants, other detergents, corrosion inhibitors, rust inhibitors, metal deactivators, extreme pressure additives, anti-seizure agents, wax modifiers, viscosity index improvers, viscosity modifiers, fluid-loss additives, seal compatibility agents, organic metallic friction modifiers, lubricity agents, anti-staining agents, chromophoric agents, defoamants, demulsifiers, emulsifiers, densifiers, wetting agents, gelling agents, tackiness agents, colorants, and others. For a review of many commonly used additives, see Klamann in Lubricants and Related Products, Verlag Chemie, Deerfield Beach, Fla.; ISBN 0-89573-177-0.
Reference is also made to “Lubricant Additives” by M. W. Ranney, published by Noyes Data Corporation of Parkridge, N J (1973); see also U.S. Pat. No. 7,704,930, the disclosure of which is incorporated herein in its entirety. These additives are commonly delivered with varying amounts of diluent oil that may range from 5 weight percent to 50 weight percent.
The types and quantities of performance additives used in combination with the instant disclosure in lubricant compositions are not limited by the examples shown herein as illustrations.

Performance Additives

The composition of the present disclosure may include small amounts of at least one (e.g., 1, 2, 3, 4, 5, or 6, or more) performance additive. For example, the composition of the present disclosure may include at least one of anticorrosive agent or corrosion inhibitor, an extreme pressure additive, an antiwear agent, a pour point depressants, an antioxidant or oxidation inhibitor, a rust inhibitor, a metal deactivator, a dispersant, a demulsifier, a dye or colorant/chromophoric agent, a seal compatibility agent, a friction modifier, a viscosity modifier/improver, a viscosity index improver, or combinations thereof. For example, solid lubricants such as molybdenum disulfide and graphite may be present in the composition of the present disclosure, such as from about 1 to about 5 wt. % (e.g., from about 1.5 to about 3 wt. %) for molybdenum disulfide and from about 3 to about 15.wt. % (e.g., from about 6 to about 12 wt. %) for graphite.
The amounts of individual additives will vary according to the additive and the level of functionality to be provided by it.
The presence or absence of these lubricating oil performance additives does not adversely affect the compositions of the present disclosure. For a review of many commonly used additives, see Klamann in Lubricants and Related Products, Verlag Chemie, Deerfield Beach, Fla.; ISBN 0 89573 177 0. Reference is also made to “Lubricant Additives” by M. W. Ranney, published by Noyes Data Corporation of Parkridge, N.J. (1973) and “Lubricant Additives: Chemistry and Applications” edited by L. R. Rudnick, published by CRC Press of Boca Raton, Fla. (2009). The performance additives useful in the present disclosure do not have to be soluble in the lubricating oils. Insoluble additives in oil can be dispersed in the lubricating oils of the present disclosure. The types and quantities of performance additives used in combination with the compositions of the present disclosure are not limited by the examples shown herein as illustrations.
As such, in any aspect or embodiment described herein, the composition further comprises at least one of anticorrosive agent or corrosion inhibitor, an extreme pressure additive, an antiwear agent, a pour point depressants, an antioxidant or oxidation inhibitor, a rust inhibitor, a metal deactivator, a dispersant, a demulsifier, a dye or colorant/chromophoric agent, a seal compatibility agent, a friction modifier, a viscosity modifier/improver, a viscosity index improver, or combinations thereof. In any aspect or embodiment described herein, the dispersant includes succinimide-type dispersant. Unless specified otherwise, the performance additive or performance additives listed above are present in a total amount equal to or less than about 10 wt. %, equal to or less than about 9.5 wt. %, equal to or less than about 9 wt. %, equal to or less than about 8.5 wt. %, equal to or less than about 8 wt. %, equal to or less than about 7.5 wt. %, equal to or less than about 7 wt. %, equal to or less than about 6.5 wt. %, equal to or less than about 6 wt. %, equal to or less than about 5.5 wt. %, equal to or less than about 5 wt. %, equal to or less than about 4.5 wt. %, equal to or less than about 4 wt. %, equal to or less than about 3.5 wt. %, equal to or less than about 3 wt. %, equal to or less than about 2.5 wt. %, equal to or less than about 2 wt. %, equal to or less than about 1.5 wt. %, or equal to or less than about 0.5 wt. %. For example, the performance additive or performance additives are present in a total amount of about 0.1 to about 10 wt. %, about 0.1 to about 9 wt. %, about 0.1 to about 8 wt. %, about 0.1 to about 7 wt. %, about 0.1 to about 6 wt. %, about 0.1 to about 5 wt. %, about 0.1 to about 4 wt. %, about 0.1 to about 3 wt. %, about 0.1 to about 2 wt. %, about 0.1 to about 1 wt. %, about 0.5 to about 10 wt. %, about 0.5 to about 9 wt. %, about 0.5 to about 8 wt. %, about 0.5 to about 7 wt. %, about 0.5 to about 6 wt. %, about 0.5 to about 5 wt. %, about 0.5 to about 4 wt. %, about 0.5 to about 3 wt. %, about 0.5 to about 2 wt. %, about 1 to about 10 wt. %, about 1 to about 9 wt. %, about 1 to about 8 wt. %, about 1 to about 7 wt. %, about 1 to about 6 wt. %, about 1 to about 5 wt. %, about 1 to about 4 wt. %, about 1 to about 3 wt. %, about 2 to about 10 wt. %, about 2 to about 9 wt. %, about 2 to about 8 wt. %, about 2 to about 7 wt. %, about 2 to about 6 wt. %, about 2 to about 5 wt. %, about 2 to about 4 wt. %, about 3 to about 10 wt. %, about 3 to about 9 wt. %, about 3 to about 8 wt. %, about 3 to about 7 wt. %, about 3 to about 6 wt. %, about 3 to about 5 wt. %, about 4 to about 10 wt. %, about 4 to about 9 wt. %, about 4 to about 8 wt. %, about 4 to about 7 wt. %, about 4 to about 6 wt. %, about 5 to about 10 wt. %, about 5 to about 9 wt. %, about 5 to about 8 wt. %, about 5 to about 7 wt. %, about 6 to about 10 wt. %, about 6 to about 9 wt. %, about 6 to about 8 wt. %, about 7 to about 10 wt. %, about 7 to about 9 wt. %, or about 8 to about 10 wt. %.
When the additives are described below by reference to individual components used in the formulation, they will not necessarily be present or identifiable as discrete entities in the final product but may be present as reaction products which are formed during the grease manufacture or even its use. This will depend on the respective chemistries of the ingredients, their stoichiometry, and the temperatures encountered in the grease making process or during its use. It will also depend, naturally enough, on whether or not the species are added as a pre-reacted additive package. For example, the acid amine phosphates may be added as discrete amines and acid phosphates but these may react to form a new entity in the final grease composition under the processing conditions used in the grease manufacture.
Viscosity Improver(s) or Modifier(s).
In any aspect or embodiment described herein, the composition of the present disclosure comprises at least one viscosity improver or modifier (e.g., 1, 2, 3, 4, 5, 6, or more viscosity improver or modifier). The viscosity improver, viscosity modifier, or Viscosity Index (VI) modifier increases the viscosity of the composition of the present disclosure at elevated temperatures, thereby increasing film thickness, and having limited effects on the viscosity of the composition of the present disclosure at low temperatures. In certain embodiments, the composition of the present disclosure comprises at least one viscosity improver (e.g., 1, 2, 3, 4, 5, 6, or more viscosity improver(s)). Any viscosity improver that is known or that becomes known in the art may be utilized in the composition of the present disclosure. Exemplary viscosity improvers include high molecular weight hydrocarbons, polyesters and viscosity index improver dispersants that function as both a viscosity index improver and a dispersant. The molecular weight of these polymers can range from about 1,000 to about 1,500,000 (e.g., about 20,000 to about 1,200,000 or about 50,000 to about 1,000,000). In a particular embodiment, the molecular weights of these polymers can range from about 1,000 to about 1,000,000 (e.g., about 1,200 to about 500,000 or about 1,200 to about 5,000).
In certain embodiments, the viscosity improver is at least one of linear or star-shaped polymers of methacrylate, linear or star-shaped copolymers of methacrylate, butadiene, olefins, alkylated styrenes, polyisobutylene, polymethacrylate (e.g., copolymers of various chain length alkyl methacrylates), copolymers of ethylene and propylene, hydrogenated block copolymers of styrene and isoprene, or combinations thereof. For example, the viscosity improver may include styrene-isoprene or styrene-butadiene based polymers of about 50,000 to about 200,000 molecular weight.
Olefin copolymers are commercially available from Chevron Oronite Company LLC under the trade designation “PARATONE®” (such as “PARATONE® 8921” and “PARATONE® 8941”); from Afton Chemical Corporation under the trade designation “HiTEC®” (such as “HiTEC® 5850B”); and from The Lubrizol Corporation under the trade designation “Lubrizol® 7067C”. Hydrogenated polyisoprene star polymers are commercially available from Infineum International Limited, e.g., under the trade designation “SV200” and “SV600”. Hydrogenated diene-styrene block copolymers are commercially available from Infineum International Limited, e.g., under the trade designation “SV 50”.
The polymethacrylate or polyacrylate polymers can be linear polymers which are available from Evnoik Industries under the trade designation “Viscoplex®” (e.g., Viscoplex 6-954) or star polymers which are available from Lubrizol Corporation under the trade designation Asteric™ (e.g., Lubrizol 87708 and Lubrizol 87725).
Illustrative vinyl aromatic-containing polymers useful in the present disclosure may be derived predominantly from vinyl aromatic hydrocarbon monomer. Illustrative vinyl aromatic-containing copolymers useful in the present disclosure may be represented by the following formula:
A-B,
wherein:

- A is a polymeric block derived predominantly from vinyl aromatic hydrocarbon monomer, and
- B is a polymeric block derived predominantly from conjugated diene monomer.

Although their presence is not required to obtain the benefit of the composition of the present disclosure, viscosity modifiers may be used in an amount of less than about 10 weight percent (e.g. less than about 7 weight percent or less than about 4 weight percent). In certain embodiments, the viscosity improver is present in an amount less than 2 weight percent, less than about 1 weight percent, or less than about 0.5 weight percent, based on the total weight of the composition of the present disclosure. Viscosity modifiers are generally added as concentrates, in large amounts of diluent oil.
As used herein, the viscosity modifier concentrations are given on an “as delivered” basis. The active polymer may be delivered with a diluent oil. The “as delivered” viscosity modifier may contain from about 20 weight percent to about 75 weight percent of an active polymer for polymethacrylate or polyacrylate polymers, or from about 8 weight percent to about 20 weight percent of an active polymer for olefin copolymers, hydrogenated polyisoprene star polymers, or hydrogenated diene-styrene block copolymers, in the “as delivered” polymer concentrate.
Antioxidant(s).
In any aspect or embodiment described herein, the composition of the present disclosure comprises at least one antioxidant (e.g., 1, 2, 3, 4, 5, 6, or more antioxidant(s)). The antioxidant(s) may be added to retard the oxidative degradation of the composition in storage or during service. Such degradation may result in deposits on metal surfaces, the presence of sludge, or a viscosity increase in the lubricant. One skilled in the art knows a wide variety of oxidation inhibitors that are useful in lubricating oil compositions. See, Klamann in Lubricants and Related Products, op cite, and U.S. Pat. Nos. 4,798,684 and 5,084,197, for example. Any antioxidant that is known or that becomes known in the art may be utilized in the composition of the present disclosure.
Two general types of oxidation inhibitors are those that react with the initiators, peroxy radicals, and hydroperoxides to form inactive compounds, and those that decompose these materials to form less active compounds. Examples are hindered (alkylated) phenols, e.g. 6-di(tert-butyl)-4-methylphenol [2,6-di(tert-butyl)-p-cresol, DBPC], and aromatic amines, e.g. N-phenyl-α-naphthalamine. These oxidation inhibitors are used in turbine, circulation, and hydraulic oils that are intended for extended service.
The antioxidant or antioxidants may be present in an amount equal to or less than about 6 wt. %, equal to or less than about 5.75 wt. %, equal to or less than about 5.5 wt. %, equal to or less than about 5.25 wt. %, equal to or less than about 5 wt. %, equal to or less than about 4.75 wt. %, equal to or less than about 4.5 wt. %, equal to or less than about 4.25 wt. %, equal to or less than about 4 wt. %, equal to or less than about 3.75 wt. %, equal to or less than about 3.5 wt. %, equal to or less than about 3.25 wt. %, equal to or less than about 3 wt. %, equal to or less than about 2.75 wt. %, equal to or less than about 2.5 wt. %, equal to or less than about 2.25 wt. %, equal to or less than about 2 wt. %, equal to or less than about 1.75 wt. %, equal to or less than about 1.5 wt. %, equal to or less than about 1.25 wt. %, equal to or less than about 1 wt. %, equal to or less than about 0.75 wt. %, equal to or less than about 0.50 wt. %, or equal to or less than about 0.25 wt. % on an as-received basis. For example, the antioxidant or antioxidants may be present in an amount of about 0.1 wt. % to about 6 wt. %, about 0.1 wt. % to about 5 wt. %, about 0.1 wt. % to about 4 wt. %, about 0.1 wt. % to about 3 wt. %, about 0.1 wt. % to about 2 wt. %, about 0.1 wt. % to about 1.5 wt. %, about 0.1 wt. % to about 1 wt. %, about 0.1 wt. % to about 0.75 wt. %, about 0.1 wt. % to about 0.5 wt. %, about 0.2 wt. % to about 6 wt. %, about 0.2 wt. % to about 5 wt. %, about 0.2 wt. % to about 4 wt. %, about 0.2 wt. % to about 3 wt. %, about 0.2 wt. % to about 2 wt. %, about 0.2 wt. % to about 1.5 wt. %, about 0.2 wt. % to about 1 wt. %, about 0.2 wt. % to about 0.75 wt. %, about 0.2 wt. % to about 0.5 wt. %, about 0.3 wt. % to about 6 wt. %, about 0.3 wt. % to about 5 wt. %, about 0.3 wt. % to about 4 wt. %, about 0.3 wt. % to about 3 wt. %, about 0.3 wt. % to about 2 wt. %, about 0.3 wt. % to about 1.5 wt. %, about 0.3 wt. % to about 1 wt. %, about 0.3 wt. % to about 0.75 wt. %, about 0.3 wt. % to about 0.5 wt. %, about 0.5 wt. % to about 6 wt. %, about 0.5 wt. % to about 5 wt. %, about 0.5 wt. % to about 4 wt. %, about 0.5 wt. % to about 3 wt. %, about 0.5 wt. % to about 2 wt. % about 0.5 wt. % to about 1.5 wt. %, about 0.5 wt. % to about 1 wt. %, about 0.5 wt. % to about 0.75 wt. %, about 0.5 wt. % to about 0.5 wt. %, about 1 wt. % to about 6 wt. %, about 1 wt. % to about 5 wt. %, about 1 wt. % to about 4 wt. %, about 1 wt. % to about 3 wt. %, about 2 wt. % to about 6 wt. %, about 2 wt. % to about 5 wt. %, about 2 wt. % to about 4 wt. %, about 3 wt. % to about 6 wt. %, about 3 wt. % to about 5 wt. %, about 4 wt. % to about 6 wt. %, or about 5 wt. % to about 6 wt. % on an as-received basis.
The below discussion of phenolic antioxidants is presented only by way of example, and is not limiting on the type of phenolic antioxidants that can be utilized in the composition of the present disclosure.
Useful antioxidants include hindered phenols. These phenolic antioxidants may be ashless (metal-free) phenolic compounds or neutral or basic metal salts of certain phenolic compounds. In an embodiment, the phenolic antioxidant compounds or compounds are hindered phenolics which are the ones which contain a sterically hindered hydroxyl group, such as those that are derivatives of dihydroxy aryl compounds in which the hydroxyl groups are in the o- or p-position to each other. In certain embodiments, the phenolic antioxidant or antioxidants are hindered phenols substituted with C6+ alkyl groups 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-t-butyl-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 proprionic ester derivatives. Bis-phenolic antioxidants may also be advantageously used in combination with the composition of the present disclosure. 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).
Further examples of phenol-based antioxidants include 2-t-butylphenol, 2-t-butyl-4-methylphenol, 2-t-butyl-5-methylphenol, 2,4-di-t-butylphenol, 2,4-dimethyl-6-t-butylphenol, 2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,5-di-t-butylhydroquinone (manufactured by the Kawaguchi Kagaku Co. under trade designation “Antage DBH”), 2,6-di-t-butylphenol and 2,6-di-t-butyl-4-alkylphenols such as 2,6-di-t-butyl-4-methylphenol and 2,6-di-t-butyl-4-ethylphenol; 2,6-di-t-butyl-4-alkoxyphenols such as 2,6-di-t-butyl-4-methoxyphenol and 2,6-di-t-butyl-4-ethoxyphenol, 3,5-di-t-butyl-4-hydroxybenzylmercaptoocty-1 acetate, alkyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionates such as n-octyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate (manufactured by the Yoshitomi Seiyaku Co. under the trade designation “Yonox SS”), n-dodecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and 2′-ethylhexyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate; 2,6-di-t-butyl-alpha-dimethylamino-p-cresol, 2,2′-methylenebis(4-alkyl-6-t-butylphenol) compounds such as 2,2′-methylenebis(4-methyl-6-t-butylphenol) (manufactured by the Kawaguchi Kagaku Co. under the trade designation “Antage W-400”) and 2,2′-methylenebis(4-ethyl-6-t-butylphenol) (manufactured by the Kawaguchi Kagaku Co. under the trade designation “Antage W-500”); bisphenols such as 4,4′-butylidenebis(3-methyl-6-t-butyl-phenol) (manufactured by the Kawaguchi Kagaku Co. under the trade designation “Antage W-300”), and 4,4′-methylenebis(2,6-di-t-butylphenol) (manufactured by Laporte Performance Chemicals under the trade designation “Ionox 220AH”).
Other examples of phenol-based antioxidants include 4,4′-bis(2,6-di-t-butylphenol), 2,2-(di-p-hydroxyphenyl)propane (Bisphenol A), 2,2-bis(3,5-di-t-butyl-4-hydroxyphenyl)propane, 4,4′-cyclohexylidenebis(2,6-di-t-butylphenol), hexamethylene glycol bis[3, (3,5-di-t-butyl-4-hydroxyphenyl)propionate] (manufactured by the Ciba Specialty Chemicals Co. under the trade designation “Irganox L109”), triethylene glycol bis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate] (manufactured by the Yoshitomi Seiyaku Co. under the trade designation “Tominox 917”), 2,2′-thio[diethyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (manufactured by the Ciba Specialty Chemicals Co. under the trade designation “Irganox L115”), 3,9-bis {1,1-dimethyl-2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]ethyl}2,4,8,10-tetraoxaspiro[5,5]undecane (manufactured by the Sumitomo Kagaku Co. under the trade designation “Sumilizer GA80”) and 4,4′-thiobis(3-methyl-6-t-butylphenol) (manufactured by the Kawaguchi Kagaku Co. under the trade designation “Antage RC”), 2,2′-thiobis(4,6-di-t-butylresorcinol); polyphenols, such as tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionato]methane (manufactured by the Ciba Specialty Chemicals Co. under the trade designation “Irganox L101”), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane (manufactured by the Yoshitomi Seiyaku Co. under the trade designation “Yoshinox 930”), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene (manufactured by Ciba Specialty Chemicals under the trade designation “Irganox 330”), bis[3,3′-bis(4′-hydroxy-3′-t-butylphenyl)butyric acid] glycol ester, 2-(3′,5′-di-t-butyl-4-hydroxyphenyl)-methyl-4-(2″,4″-di-t-butyl-3″-hydroxyphenyl)methyl-6-t-butylphenol and 2,6-bis(2′-hydroxy-3′-t-butyl-5′-methylbenzyl)-4-methylphenol; and phenol/aldehyde condensates, such as the condensates of p-t-butylphenol and formaldehyde and the condensates of p-t-butylphenol and acetaldehyde.
The phenolic antioxidant or phenolic type antioxidant include sulfurized and non-sulfurized phenolic antioxidants. Phenolic antioxidants include compounds having one or more than one hydroxyl group bound to an aromatic ring which may itself be mononuclear (e.g., benzyl) or poly-nuclear (e.g., naphthyl and spiro aromatic compounds). Thus, phenol type antioxidants include phenol per se, catechol, resorcinol, hydroquinone, naphthol, etc., as well as alkyl or alkenyl and sulfurized alkyl or alkenyl derivatives thereof, and bisphenol type compounds including such bi-phenol compounds linked by alkylene bridges sulfuric bridges or oxygen bridges. Alkyl phenols may include mono- and poly-alkyl or alkenyl phenols, the alkyl or alkenyl group containing from about 3 to about 100 carbons (e.g., about 4 to about 50 carbons) and sulfurized derivatives thereof. The number of alkyl or alkenyl groups present in the aromatic ring may range from 1 up to the available unsatisfied valences of the aromatic ring remaining after counting the number of hydroxyl groups bound to the aromatic ring.
For example, the phenolic antioxidant may be represented by the following formula:
(R)_x—Ar—(OH)_y,
wherein:
Ar is selected from the group consisting of:
wherein:
R is a C₃-C₁₀₀alkyl or alkenyl group, a sulfur substituted alkyl or alkenyl group (e.g., a C₄-C₅₀alkyl or alkenyl group or sulfur substituted alkyl or alkenyl group, a C₃-C₁₀₀alkyl or sulfur substituted alkyl group, or a C₄-C₅₀alkyl group);
R^gis a C₁-C₁₀₀alkylene or sulfur substituted alkylene group (e.g., a C₂-C₅₀alkylene or sulfur substituted alkylene group or a C₂-C₂alkylene or sulfur substituted alkylene group);
y is at least 1 to up to the available valences of Ar;
x ranges from 0 to up to the available valances of Ar-y;
z ranges from 1 to 10;
n ranges from 0 to 20;
m is 0 to 4; and
p is 0 or 1.
In certain embodiments, at least one of: R is C₄-C₅₀alkyl group, R^gis a C₂-C₂₀alkylene or sulfur substituted alkylene group, y ranges from 1 to 3, x ranges from 0 to 3, z ranges from 1 to 4, n ranges from 0 to 5, p is 0, or a combination thereof.
In particular embodiments, the phenolic antioxidant include hindered phenolics and phenolic esters that contain a sterically hindered hydroxyl group. For example, the phenolic antioxidant can include derivatives of dihydroxy aryl compounds in which the hydroxyl groups are in the o- or p-position to each other. The phenolic antioxidant may include the hindered phenols substituted with C₁+ alkyl groups and the alkylene coupled derivatives of these hindered phenols, such as: 2-t-butyl-4-heptyl phenol; 2-t-butyl-4-octyl phenol; 2-t-butyl-4-dodecyl phenol; 2,6-di-t-butyl-4-heptyl phenol; 2,6-di-t-butyl-4-dodecyl phenol; 2-methyl-6-t-butyl-4-heptyl phenol; 2-methyl-6-t-butyl-4-dodecyl phenol; 2,6-di-t-butyl-4 methyl phenol; 2,6-di-t-butyl-4-ethyl phenol; 2,6-di-t-butyl 4 alkoxy phenol; and/or
In certain embodiments, the phenolic type antioxidant is at least one of Ethanox® 4710, Irganox® 1076, Irganox® L1035, Irganox® 1010, Irganox® L109, Irganox® L118, Irganox® L135, or a combination thereof.
The phenolic antioxidant or antioxidants may be present in an amount of about 0.05 wt. % to about 3 wt. %, about 0.05 wt. % to about 2.5 wt. %, about 0.05 wt. % to about 2 wt. %, about 0.05 wt. % to about 1.5 wt. %, about 0.05 wt. % to about 1 wt. %, about 0.05 wt. % to about 0.75 wt. %, about 0.05 wt. % to about 0.5 wt. %, about 0.05 wt. % to about 0.3 wt. %, about 0.1 wt. % to about 3 wt. %, about 0.1 wt. % to about 2.5 wt. %, about 0.1 wt. % to about 2 wt. %, about 0.1 wt. % to about 1.5 wt. %, about 0.1 wt. % to about 1 wt. %, about 0.1 wt. % to about 0.75 wt. %, about 0.1 wt. % to about 0.5 wt. %, about 0.1 wt. % to about 0.3 wt. %, about 0.5 wt. % to about 3 wt. %, about 0.5 wt. % to about 2.5 wt. %, about 0.5 wt. % to about 2 wt. %, about 0.5 wt. % to about 1.5 wt. %, about 0.5 wt. % to about 1 wt. %, about 1 wt. % to about 3 wt. %, about 1 wt. % to about 2.5 wt. %, about 1 wt. % to about 2 wt. %, about 1 wt. % to about 1.75 wt. %, about 1 wt. % to about 1.5 wt. %, about 1.5 wt. % to about 3 wt. %, about 1.5 wt. % to about 2.5 wt. %, about 1.5 wt. % to about 2 wt. %, about 2 wt. % to about 3 wt. %, about 2 wt. % to about 2.5 wt. %, or about 2.5 wt. % to about 3 wt. %, on an as-received basis.
Effective amounts of one or more catalytic antioxidants may be used. The catalytic antioxidants comprise an effective amount of a) one or more oil soluble polymetal organic compounds; and, effective amounts of b) one or more substituted N,N′-diaryl-o-phenylenediamine compounds or c) one or more hindered phenol compounds; or a combination of both b) and c). Catalytic antioxidants are more fully described in U.S. Pat. No. 8,048,833, which is incorporated herein by reference in its entirety.
Non-phenolic oxidation inhibitors that may be used in the composition of the present disclosure include aromatic amine antioxidants, which may be used either as such or in combination with phenolic antioxidants.
An exemplary aromatic amine antioxidant include alkylated and non-alkylated aromatic amines, such as aromatic monoamines of the formula
R¹R²R³N,
wherein:
R¹is an aliphatic, aromatic or substituted aromatic group;
R²is an aromatic or a substituted aromatic group;
R³is H, alkyl, aryl or R⁴S(O)_xR⁵;
R⁴is an alkylene, alkenylene, or aralkylene group;
R⁵is a higher alkyl group, or an alkenyl, aryl, or alkaryl group; and
x is 0, 1 or 2.
The aliphatic group R¹may contain from 1 to about 20 carbon atoms (e.g. from about 6 to 12 carbon atoms). The aliphatic group may be a saturated aliphatic group. In certain embodiments, both R¹and R²are aromatic or substituted aromatic groups, and the aromatic group may be a fused ring aromatic group such as naphthyl. Aromatic groups R¹and R²may be joined together with other groups such as S.
The aminic antioxidant may be an aromatic amine antioxidant, such as an phenyl-α-naphthyl amine (e.g., Irganox® L06) which is described by the following chemical structure:
wherein:
R^zis hydrogen or a C₁to C₁₄linear or C₃to C₁₄branched alkyl group; and
n is an integer ranging from 1 to 5 (e.g. 1).
In certain embodiments, at least one of: R^zis C₁to C₁₀linear or C₃to C₁₀branched alkyl group; n is 1; or a combination thereof,
In another embodiment, R^zis a linear or branched C₆to C₈.
In certain embodiments, the aromatic amine antioxidant can have at least 6 carbon atoms substituted with an alkyl groups. Examples of aliphatic groups include hexyl, heptyl, octyl, nonyl, and decyl. In an embodiments, the aliphatic groups will not contain more than about 14 carbon atoms. Additional amine antioxidants include diphenylamines, phenyl naphthylamines, phenothiazines, imidodibenzyls, and diphenyl phenylene diamines. In a particular embodiment, a mixture of two or more (e.g., 2, 3, 4, 5, or more) aromatic amine antioxidants are present in the composition of the present disclosure. Polymeric amine antioxidants can also be used. Particular examples of aromatic amine antioxidants useful in the composition of the present disclosure include: p,p′-dioctyldiphenylamine; t-octylphenyl-alpha-naphthylamine; phenyl-alphanaphthylamine; and p-octylphenyl-alpha-naphthylamine.
Further examples of amine-based antioxidants include dialkyldiphenylamines, such as p,p′-dioctyldiphenylamine (manufactured by the Seiko Kagaku Co. under the trade designation “Nonflex OD-3”), p,p′-di-alpha-methylbenzyl-diphenylamine and N-p-butylphenyl-N-p′-octylphenylamine; monoalkyldiphenylamines, such as mono-t-butyldiphenylamine, and monooctyldiphenylamine; bis(dialkylphenyl)amines such as di(2,4-diethylphenyl)amine and di(2-ethyl-4-nonylphenyl)amine; alkylphenyl-1-naphthylamines, such as octylphenyl-1-naphthylamine and N-t-dodecylphenyl-1-naphthylamine; arylnaphthylamines, such as 1-naphthylamine, phenyl-1-naphthylamine, phenyl-2-naphthylamine, N-hexylphenyl-2-naphthylamine and N-octylphenyl-2-naphthylamine, phenylenediamines such as N,N′-diisopropyl-p-phenylenediamine and N,N′-diphenyl-p-phenylenediamine, and phenothiazines such as phenothiazine (manufactured by the Hodogaya Kagaku Co.: Phenothiazine) and 3,7-dioctylphenothiazine.
A sulfur-containing antioxidant may be any and every antioxidant containing sulfur, for example, including dialkyl thiodipropionates such as dilauryl thiodipropionate and distearyl thiodipropionate, dialkyldithiocarbamic acid derivatives (excluding metal salts), bis(3,5-di-t-butyl-4-hydroxybenzyl)sulfide, mercaptobenzothiazole, reaction products of phosphorus pentoxide and olefins, and dicetyl sulfide. For example, the sulfur-containing antioxidant is a dialkyl thiodipropionate, such as dilauryl thiodipropionate and distearyl thiodipropionate.
Additional examples of sulphur-based antioxidants include dialkylsulphides, such as didodecylsulphide and dioctadecylsulphide; thiodipropionic acid esters, such as didodecyl thiodipropionate, dioctadecyl thiodipropionate, dimyristyl thiodipropionate and dodecyloctadecyl thiodipropionate, and 2-mercaptobenzimidazole. In an embodiment, the antioxidant is a sulfurized alkyl phenols, or an alkali or alkaline earth metal salt thereof.
In certain embodiments, the composition of the present disclosure includes at least one aminic antioxidant (e.g., 1, 2, 3, 4, 5, or more) present in an amount equal to or less than about 6 wt. %, equal to or less than about 5.75 wt. %, equal to or less than about 5.5 wt. %, equal to or less than about 5.25 wt. %, equal to or less than about 5 wt. %, equal to or less than about 4.75 wt. %, equal to or less than about 4.5 wt. %, equal to or less than about 4.25 wt. %, equal to or less than about 4 wt. %, equal to or less than about 3.75 wt. %, equal to or less than about 3.5 wt. %, equal to or less than about 3.25 wt. %, equal to or less than about 3 wt. %, equal to or less than about 2.75 wt. %, equal to or less than about 2.5 wt. %, equal to or less than about 2.25 wt. %, equal to or less than about 2 wt. %, equal to or less than about 1.75 wt. %, equal to or less than about 1.5 wt. %, equal to or less than about 1.25 wt. %, equal to or less than about 1 wt. %, equal to or less than about 0.75 wt. %, equal to or less than about 0.50 wt. %, or equal to or less than about 0.25 wt. % on an as-received basis. For example, the aminic antioxidant or antioxidants may be present in an amount of about 0.1 wt. % to about 6 wt. %, about 0.1 wt. % to about 5 wt. %, about 0.1 wt. % to about 4 wt. %, about 0.1 wt. % to about 3 wt. %, about 0.1 wt. % to about 2 wt. %, about 0.1 wt. % to about 1.5 wt. %, about 0.1 wt. % to about 1 wt. %, about 0.1 wt. % to about 0.75 wt. %, about 0.1 wt. % to about 0.5 wt. %, about 0.2 wt. % to about 6 wt. %, about 0.2 wt. % to about 5 wt. %, about 0.2 wt. % to about 4 wt. %, about 0.2 wt. % to about 3 wt. %, about 0.2 wt. % to about 2 wt. %, about 0.2 wt. % to about 1.5 wt. %, about 0.2 wt. % to about 1 wt. %, about 0.2 wt. % to about 0.75 wt. %, about 0.2 wt. % to about 0.5 wt. %, about 0.3 wt. % to about 6 wt. %, about 0.3 wt. % to about 5 wt. %, about 0.3 wt. % to about 4 wt. %, about 0.3 wt. % to about 3 wt. %, about 0.3 wt. % to about 2 wt. %, about 0.3 wt. % to about 1.5 wt. %, about 0.3 wt. % to about 1 wt. %, about 0.3 wt. % to about 0.75 wt. %, about 0.3 wt. % to about 0.5 wt. %, about 0.5 wt. % to about 6 wt. %, about 0.5 wt. % to about 5 wt. %, about 0.5 wt. % to about 4 wt. %, about 0.5 wt. % to about 3 wt. %, about 0.5 wt. % to about 2 wt. %, about 0.5 wt. % to about 1.5 wt. %, about 0.5 wt. % to about 1 wt. %, about 0.5 wt. % to about 0.75 wt. %, about 0.5 wt. % to about 0.5 wt. %, about 1 wt. % to about 6 wt. %, about 1 wt. % to about 5 wt. %, about 1 wt. % to about 4 wt. %, about 1 wt. % to about 3 wt. %, about 2 wt. % to about 6 wt. %, about 2 wt. % to about 5 wt. %, about 2 wt. % to about 4 wt. %, about 3 wt. % to about 6 wt. %, about 3 wt. % to about 5 wt. %, about 4 wt. % to about 6 wt. %, or about 5 wt. % to about 6 wt. % on an as-received basis.
Other oxidation inhibitors that have proven useful in compositions of the present disclosure are chlorinated aliphatic hydrocarbons such as chlorinated wax; organic sulfides and polysulfides such as benzyl disulfide, bis(chlorobenzyl)disulfide, dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized alkylphenol, sulfurized dipentene, and sulfurized terpene; phosphosulfurized hydrocarbons such as the reaction product of a phosphorus sulfide with turpentine or methyl oleate, phosphorus esters including principally dihydrocarbon and trihydrocarbon phosphites such as dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite, dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite, dimethyl naphthyl phosphite, oleyl 4-pentylphenyl phosphite, polypropylene (molecular weight 500)-substituted phenyl phosphite, diisobutyl-substituted phenyl phosphite; metal thiocarbamates, such as zinc dioctyldithiocarbamate, and barium heptylphenyl dithiocarbamate; Group II metal phosphorodithioates such as zinc dicyclohexylphosphorodithioate, zinc dioctylphosphorodithioate, barium di(heptylphenyl)(phosphorodithioate, cadmium dinonylphosphorodithioate, and the reaction of phosphorus pentasulfide with an equimolar mixture of isopropyl alcohol, 4-methyl-2-pentanol, and n-hexyl alcohol.
Another class of antioxidants which may be used in the lubricating oil compositions disclosed herein are oil soluble copper compounds. Any oil soluble suitable copper compound may be blended into the composition of the present disclosure. Examples of suitable copper antioxidants include copper dihydrocarbyl thio- or dithio-phosphates and copper salts of carboxylic acid (naturally occurring or synthetic). Other suitable copper salts include copper dithiacarbamates, sulphonates, phenates, and acetylacetonates. Basic, neutral, or acidic copper Cu(I) and or Cu(II) salts derived from alkenyl succinic acids or anhydrides are known to be particularly useful.
In an embodiment, the antioxidant includes hindered phenols, arylamines, or a combination thereof. These antioxidants may be used individually by type or in combination with one another.
Pour Point Depressant(s).
In any aspect or embodiment described herein, the composition of the present disclosure comprises at least one (e.g., 1, 2, 3, 4, 5, or 6, or more) pour point depressant or a lube oil flow improver. Pour point depressant may be added to lower the minimum temperature at which the fluid will flow or can be poured. Any pour point depressant or lube oil flow improved that is known or that becomes known in the art may be utilized in the composition of the present disclosure. In certain embodiments, the pour point depressant includes at least one (e.g., 1, 2, 3, or 4 or more) pour point depressant or lube oil flow improver, such as at least one of alkylated naphthalenes polymethacrylates (e.g., copolymers of various chain length alkyl methacrylates), polyacrylates, polyarylamides, condensation products of haloparaffin waxes and aromatic compounds, vinyl carboxylate polymers, terpolymers of dialkylfumarates, vinyl esters of fatty acids, allyl vinyl ethers, or combinations thereof. U.S. Pat. Nos. 1,815,022; 2,015,748; 2,191,498; 2,387,501; 2,655, 479; 2,666,746; 2,721,877; 2,721,878; and 3,250,715 describe useful pour point depressants and/or the preparation thereof. The pour point depressant or depressants may be present in an amount equal to or less than about 5 wt. %, for example about 0.01 to about 1.5 wt. %. For example, the pour point depressant or depressants may be present in an amount equal to or less than about 5 wt. %, equal to or less than about 4.75 wt. %, equal to or less than about 4.5 wt. %, equal to or less than about 4.25 wt. %, equal to or less than about 4 wt. %, equal to or less than about 3.75 wt. %, equal to or less than about 3.5 wt. %, equal to or less than about 3.25 wt. %, equal to or less than about 3 wt. %, equal to or less than about 2.75 wt. %, equal to or less than about 2.5 wt. %, equal to or less than about 2.25 wt. %, equal to or less than about 2 wt. %, equal to or less than about 1.75 wt. %, equal to or less than about 1.5 wt. %, equal to or less than about 1.25 wt. %, equal to or less than about 1 wt. %, equal to or less than about 0.75 wt. %, equal to or less than about 0.50 wt. %, or equal to or less than about 0.25 wt. % of the composition of the present disclosure. For example, the pour point depressant or depressants may be present in an amount of about 0.1 wt. % to about 5 wt. %, about 0.1 wt. % to about 4 wt. %, about 0.1 wt. % to about 3 wt. %, about 0.1 wt. % to about 2 wt. %, about 0.1 wt. % to about 1.5 wt. %, about 0.1 wt. % to about 1 wt. %, about 0.1 wt. % to about 0.75 wt. %, about 0.1 wt. % to about 0.5 wt. %, about 0.2 wt. % to about 5 wt. %, about 0.2 wt. % to about 4 wt. %, about 0.2 wt. % to about 3 wt. %, about 0.2 wt. % to about 2 wt. %, about 0.2 wt. % to about 1.5 wt. %, about 0.2 wt. % to about 1 wt. %, about 0.2 wt. % to about 0.75 wt. %, about 0.2 wt. % to about 0.5 wt. %, about 0.3 wt. % to about 5 wt. %, about 0.3 wt. % to about 4 wt. %, about 0.3 wt. % to about 3 wt. %, about 0.3 wt. % to about 2 wt. %, about 0.3 wt. % to about 1.5 wt. %, about 0.3 wt. % to about 1 wt. %, about 0.3 wt. % to about 0.75 wt. %, about 0.3 wt. % to about 0.5 wt. %, about 0.5 wt. % to about 5 wt. %, about 0.5 wt. % to about 4 wt. %, about 0.5 wt. % to about 3 wt. %, about 0.5 wt. % to about 2 wt. %, about 0.5 wt. % to about 1.5 wt. %, about 0.5 wt. % to about 1 wt. %, about 0.5 wt. % to about 0.75 wt. %, about 0.5 wt. % to about 0.5 wt. %, about 1 wt. % to about 5 wt. %, about 1 wt. % to about 4 wt. %, about 1 wt. % to about 3 wt. %, about 2 wt. % to about 5 wt. %, about 2 wt. % to about 4 wt. %, or about 3 wt. % to about 5 wt. % of the composition of the present disclosure.
Seal Compatibility Agent(s).
In other embodiments, the composition comprises of the present disclosure at least one (e.g., 1, 2, 3, 4, or more) seal compatibility agent. The seal compatibility agent(s) may be added to help swell elastomeric seals by causing a chemical reaction in the fluid or physical change in the elastomer. Any seal compatibility agent that is known or that becomes know may be utilized in the composition of the present disclosure. For example, the seal compatibility agent or agents may include at least one of organic phosphates, aromatic esters, aromatic hydrocarbons, esters (e.g. butylbenzyl phthalate), polybutenyl succinic anhydride, or sulfolane-type seal swell agents (e.g. Lubrizol 730-type seal swell additives), or combinations thereof. Although their presence is not required to obtain the benefit of the present disclosure, seal compatibility additives may be present in an amount of zero to about 3 weight percent (e.g., about 0.01 to about 2 weight percent) of the composition of the present disclosure.
Demulsifier(s).
In any aspect or embodiment described herein, the composition of the present disclosure comprises at least one (e.g., 1, 2, 3, or 4, or more) demulsifier. The demulsifier may be added to separate emulsions (e.g., water-in-oil). Any demulsifier that is known or that becomes know may be utilized in the composition of the present disclosure. An illustrative demulsifying component is described in EP-A-330,522. This exemplary demulsifying agent is obtained by reacting an alkylene oxide with an adduct obtained by reaction of a bis-epoxide with a polyhydric alcohol. Demulsifiers are commercially available and may be used in conventional minor amounts along with other additives such as antifoam agents. Although their presence is not required to obtain the benefit of the present disclosure, the emulsifier or emulsifiers may be present a combined amount less than 1 weight percent (e.g. less than 0.1 weight percent).
In certain embodiments, the demulsifying agent includes at least one of alkoxylated phenols, phenol-formaldehyde resins, synthetic alkylaryl sulfonates (such as metallic dinonylnaphthalene sulfonates), or a combination thereof. In an embodiment, a demulsifing agent is a predominant amount of a water-soluble polyoxyalkylene glycol having a pre-selected molecular weight of any value in the range of between about 450 and about 5000 or more. In an embodiment, the water soluble polyoxyalkylene glycol demulsifier may also be one produced from alkoxylation of n-butanol with a mixture of alkylene oxides to form a random alkoxylated product.
Polyoxyalkylene glycols useful in the present disclosure may be produced by a well-known process for preparing polyalkylene oxide having hydroxyl end-groups by subjecting an alcohol or a glycol ether and one or more alkylene oxide monomers, such as ethylene oxide, butylene oxide, or propylene oxide, to form block copolymers in addition polymerization, while employing a strong base, such as potassium hydroxide as a catalyst. In such a process, the polymerization is commonly carried out under a catalytic concentration of about 0.3 to about 1.0% by mole of potassium hydroxide to the monomer(s) and at high temperature of about 100° C. to about 160° C. It is well known that the catalyst potassium hydroxide is, for the most part, bonded to the chain-end of the produced polyalkylene oxide in a form of alkoxide in the polymer solution so obtained.
The soluble polyoxyalkylene glycol emulsifier(s) useful in the compositions of the present disclosure may also be one produced from alkoxylation of n-butanol with a mixture of alkylene oxides to form a random alkoxylated product.
Corrosion Inhibitor or Anti-Rust Additive.
In any aspect or embodiment, the composition of the present disclosure comprises at least one (e.g. 1, 2, 3, 4, or more) corrosion inhibitor or anti-rust additive. The corrosion inhibitor or anti-rust additive may be added to protect lubricated metal surfaces against chemical attack by water or other contaminants. A wide variety of corrosion inhibitors are commercially available, and any corrosion inhibitor or anti-rust additive that is known or that becomes know may be utilized in the composition of the present disclosure. In an embodiment, the corrosion inhibitor can be a polar compound that wets the metal surface protecting it with a film of oil. In another embodiment, the anti-rust additive may absorb water by incorporating it in a water-in-oil emulsion so that only the oil touches the surface. In yet a further embodiment, the corrosion inhibitor chemically adheres to the metal to produce a non-reactive surface. In certain embodiments, the anti-rust additive or corrosion inhibitor includes at least one zinc dithiophosphates, metal phenolates, basic metal sulfonates, a fatty acid, a fatty acid mixture, amines, or a combination thereof.
Antirust additives may include (short-chain) alkenyl succinic acids, partial esters thereof and nitrogen-containing derivatives thereof; and synthetic alkarylsulfonates, such as metal dinonylnaphthalene sulfonates. Antirust agents include, for example, monocarboxylic acids which have from 8 to 30 carbon atoms, alkyl or alkenyl succinates or partial esters thereof, hydroxy-fatty acids, which have from 12 to 30 carbon atoms and derivatives thereof, sarcosines which have from 8 to 24 carbon atoms and derivatives thereof, amino acids and derivatives thereof, naphthenic acid and derivatives thereof, lanolin fatty acid, mercapto-fatty acids, and/or paraffin oxides.
Examples of monocarboxylic acids (C8-C30), include, for example, caprylic acid, pelargonic acid, decanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachic acid, behenic acid, cerotic acid, montanic acid, melissic acid, oleic acid, docosanic acid, erucic acid, eicosenic acid, beef tallow fatty acid, soy bean fatty acid, coconut oil fatty acid, linolic acid, linoleic acid, tall oil fatty acid, 12-hydroxystearic acid, laurylsarcosinic acid, myritsylsarcosinic acid, palmitylsarcosinic acid, stearylsarcosinic acid, oleylsarcosinic acid, alkylated (C8-C20) phenoxyacetic acids, lanolin fatty acid, and C8-C24 mercapto-fatty acids.
Examples of polybasic carboxylic acids include, for example, the alkenyl (C10-C100) succinic acids indicated in CAS No. 27859-58-1 and ester derivatives thereof, dimer acid, N-acyl-N-alkyloxyalkyl aspartic acid esters (U.S. Pat. No. 5,275,749).
Examples of the alkylamines that function as antirust additives or as reaction products with the above carboxylates to give amides and the like are represented by primary amines, such as laurylamine, coconut-amine, n-tridecylamine, myristylamine, n-pentadecylamine, palmitylamine, n-heptadecylamine, stearylamine, n-nonadecylamine, n-eicosylamine, n-heneicosylamine, n-docosylamine, n-tricosylamine, n-pentacosylamine, oleylamine, beef tallow-amine, hydrogenated beef tallow-amine and soy bean-amine. Examples of the secondary amines include dilaurylamine, di-coconut-amine, di-n-tridecylamine, dimyristylamine, di-n-pentadecylamine, dipalmitylamine, di-n-pentadecylamine, distearylamine, di-n-nonadecylamine, di-n-eicosylamine, di-n-heneicosylamine, di-n-docosylamine, di-n-tricosylamine, di-n-pentacosyl-amine, dioleylamine, di-beef tallow-amine, di-hydrogenated beef tallow-amine and di-soy bean-amine.
Examples of the aforementioned N-alkylpolyalkyenediamines include: ethylenediamines, such as laurylethylenediamine, coconut ethylenediamine, n-tridecylethylenediamine-, myristylethylenediamine, n-pentadecylethylenediamine, palmitylethylenediamine, n-heptadecylethylenediamine, stearylethylenediamine, n-nonadecylethylenediamine, n-eicosylethylenediamine, n-heneicosylethylenediamine, n-docosylethylendiamine, n-tricosylethylenediamine, n-pentacosylethylenediamine, oleylethylenediamine, beef tallow-ethylenediamine, hydrogenated beef tallow-ethylenediamine and soy bean-ethylenediamine; propylenediamines such as laurylpropylenediamine, coconut propylenediamine, n-tridecylpropylenediamine, myristylpropylenediamine, n-pentadecylpropylenediamine, palmitylpropylenediamine, n-heptadecylpropylenediamine, stearylpropylenediamine, n-nonadecylpropylenediamine, n-eicosylpropylenediamine, n-heneicosylpropylenediamine, n-docosylpropylendiamine, n-tricosylpropylenediamine, n-pentacosylpropylenediamine, diethylene triamine (DETA) or triethylene tetramine (TETA), oleylpropylenediamine, beef tallow-propylenediamine, hydrogenated beef tallow-propylenediamine and soy bean-propylenediamine; butylenediamines such as laurylbutylenediamine, coconut butylenediamine, n-tridecylbutylenediamine-, myristylbutylenediamine, n-pentadecylbutylenediamine, stearylbutylenediamine, n-eicosylbutylenediamine, n-heneicosylbutylenediamine, n-docosylbutylendiamine, n-tricosylbutylenediamine, n-pentacosylbutylenediamine, oleylbutylenediamine, beef tallow-butylenediamine, hydrogenated beef tallow-butylenediamine and soy bean butylenediamine; and pentylenediamines such as laurylpentylenediamine, coconut pentylenediamine, myristylpentylenediamine, palmitylpentylenediamine, stearylpentylenediamine, oleyl-pentylenediamine, beef tallow-pentylenediamine, hydrogenated beef tallow-pentylenediamine and soy bean pentylenediamine.
The corrosion inhibitor or anti-rust additive may be present in an amount equal to or less than about 5 wt. %, for example about 0.01 to 5 wt. %, on an as-received basis. For example, the corrosion inhibitor may be present in an amount equal to or less than 4 wt. %, equal or less than 3 wt. %, equal to or less than 2 wt. %, or equal to or less than 1 wt. % on an as-received basis. By way of further example, the corrosion inhibitor may be present in an amount of about 0.01 to about 5 wt. %, about 0.01 to about 4 wt. %, about 0.01 to about 3 wt. %, about 0.01 to about 2 wt. %, about 0.05 to about 5 wt. %, about 0.05 to about 4 wt. %, about 0.05 to about 3 wt. %, about 0.05 to about 2 wt. %, about 0.1 to about 5 wt. %, about 0.1 to about 4 wt. %, about 0.1 to about 3 wt. %, about 0.1 to about 2 wt. %, about 1 to about 5 wt. %, about 1 to about 4 wt. %, about 1 to about 3 wt. %, about 2 to about 5 wt. %, about 2 to about 4 wt. %, or about 3 to about 5 wt. %, on an as-received basis.
Metal Passivator(s), Deactivator(s) and Corrosion Inhibitor(s).
In any aspect or embodiment, the composition of the present disclosure comprises at least one (e.g. 1, 2, 3, 4, 5, or 6, or more) metal passivator, deactivator, or corrosion inhibitor. This type of component includes 2,5-dimercapto-1,3,4-thiadiazoles and derivatives thereof, mercaptobenzothiazoles, alkyltriazoles and benzotriazoles. Examples of dibasic acids useful as anti-corrosion agents, other than sebacic acids, which may be used in the present disclosure, are adipic acid, azelaic acid, dodecanedioic acid, 3-methyladipic acid, 3-nitrophthalic acid, 1,10-decanedicarboxylic acid, and fumaric acid. The anti-corrosion combination is a straight or branch-chained, saturated or unsaturated monocarboxylic acid or ester thereof which may optionally be sulphurized in an amount up to 35% by weight. In an embodiment, the acid is a C4 to C22 straight chain unsaturated monocarboxylic acid. The monocarboxylic acid may be a sulphurized oleic acid. However, other suitable materials are oleic acid itself, valeric acid and erucic acid. A component of the anti-corrosion combination is a triazole as previously defined. In an embodiment, the triazole is tolylotriazole, which may be included in the compositions of the disclosure include triazoles, thiazoles and certain diamine compounds which are useful as metal deactivators or metal passivators. Examples include triazole, benzotriazole and substituted benzotriazoles, such as alkyl substituted derivatives. The alkyl substituent may contain up to 1.5 carbon atoms, e.g. up to 8 carbon atoms. The triazoles may contain other substituents on the aromatic ring such as halogens, nitro, amino, mercapto, etc. Examples of suitable compounds are benzotriazole and the tolyltriazoles, ethylbenzotriazoles, hexylbenzotriazoles, octylbenzotriazoles, chlorobenzotriazoles and nitrobenzotriazoles. In a particular embodiment, the compound is benzotriazole and/or tolyltriazole.
Illustrative substituents include, for example, alkyl that is straight or branched chain, for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl or n-eicosyl; alkenyl that is straight or branched chain, for example, prop-2-enyl, but-2-enyl, 2-methyl-prop-2-enyl, pent-2-enyl, hexa-2,4-dienyl, dec-10-enyl or eicos-2-enyl; cycloalkyl that is, for example, cyclopentyl, cyclohexyl, cyclooctyl, cyclodecyl, adamantyl or cyclododecyl; aralkyl that is, for example, benzyl, 2-phenylethyl, benzhydryl or naphthylmethyl; aryl that is, for example, phenyl or naphthyl; heterocyclic group that is, for example, a morpholine, pyrrolidine, piperidine or a perhydroazepine ring; alkylene moieties that include, for example, methylene, ethylene, 1:2- or 1:3-propylene, 1:4-butylene, 1:6-hexylene, 1:8-octylene, 1:10-decylene and 1:12-dodecylene.
Illustrative arylene moieties include, for example, phenylene and naphthylene. 1-(or 4)-(dimethylaminomethyl) triazole, 1-(or 4)-(diethylaminomethyl) triazole, 1-(or 4)-(di-isopropylaminomethyl) triazole, 1-(or 4)-(di-n-butylaminomethyl) triazole, 1-(or 4)-(di-n-hexylaminomethyl) triazole, 1-(or 4)-(di-isooctylaminomethyl) triazole, 1-(or 4)-(di-(2-ethylhexyl)aminomethyl) triazole, 1-(or 4)-(di-n-decylaminomethyl) triazole, 1-(or 4)-(di-n-dodecylaminomethyl) triazole, 1-(or 4)-(di-n-octadecylaminomethyl) triazole, 1-(or 4)-(di-n-eicosylaminomethyl) triazole, 1-(or 4)-[di-(prop-2′-enyl)aminomethyl] triazole, 1-(or 4)-[di-(but-2′-enyl)aminomethyl] triazole, 1-(or 4)-[di-(eicos-2′-enyl)aminomethyl] triazole, 1-(or 4)-(di-cyclohexylaminomethyl) triazole, 1-(or 4)-(di-benzylaminomethyl) triazole, 1-(or 4)-(di-phenylaminomethyl) triazole, 1-(or 4)-(4′-morpholinomethyl) triazole, 1-(or 4)-(1′-pyrrolidinomethyl) triazole, 1-(or 4)-(1′-piperidinomethyl) triazole, 1-(or 4)-(1′-perhydoroazepinomethyl) triazole, 1-(or 4)-(2′,2″-dihydroxyethyl)aminomethyl]triazole, 1-(or 4)-(dibutoxypropyl-aminomethyl) triazole, 1-(or 4)-(dibutylthiopropyl-aminomethyl) triazole, 1-(or 4)-(di-butylaminopropyl-aminomethyl) triazole, 1-(or-4)-(1-methanomine)-N,N-bis(2-ethylhexyl)-methyl benzotriazole, N,N-bis-(1- or 4-triazolylmethyl) laurylamine, N,N-bis-(1- or 4-triazolylmethyl) oleylamine, N,N-bis-(1- or 4-triazolylmethyl) ethanolamine and N,N,N′,N′-tetra(1- or 4-triazolylmethyl) ethylene diamine.
The metal deactivating agents which can be used in the composition of the present disclosure includes, for example, benzotriazole and the 4-alkylbenzotriazoles such as 4-methylbenzotriazole and 4-ethylbenzotriazole; 5-alkylbenzotriazoles such as 5-methylbenzotriazole, 5-ethylbenzotriazole; 1-alkylbenzotriazoles such as 1-dioctylauainomethyl-2,3-benzotriazole; benzotriazole derivatives such as the 1-alkyltolutriazoles, for example, 1-dioctylaminomethyl-2,3-t-olutriazole; benzimidazole and benzimidazole derivatives such as 2-(alkyldithio)-benzimidazoles, for example, such as 2-(octyldithio)-benzimidazole, 2-(decyldithio)benzimidazole and 2-(dodecyldithio)-benzimidazole; 2-(alkyldithio)-toluimidazoles such as 2-(octyldithio)-toluimidazole, 2-(decyldithio)-toluimidazole and 2-(dodecyldithio)-toluimidazole; indazole and indazole derivatives of toluimidazoles such as 4-alkylindazole, 5-alkylindazole; benzothiazole, 2-mercaptobenzothiazole derivatives (manufactured by the Chiyoda Kagaku Co. under the trade designation “Thiolite B-3100”) and 2-(alkyldithio)benzothiazoles such as 2-(hexyldithio)benzothiazole and 2-(octyldithio)benzothiazole; 2-(alkyl-dithio)toluthiazoles such as 2-(benzyldithio)toluthiazole and 2-(octyldithio)toluthiazole, 2-(N,N-dialkyldithiocarbamyl)benzothiazoles such as 2-(N,N-diethyldithiocarbamyl)benzothiazole, 2-(N,N-dibutyldithiocarbamyl)-benzotriazole and 2-N,N-dihexyl-dithiocarbamyl)benzotriazole; benzothiazole derivatives of 2-(N,N-dialkyldithiocarbamyl)toluthiazoles such as 2-(N,N-diethyldithiocarbamyl)toluthiazole, 2-(N,N-dibutyldithiocarbamyl)toluthiazole, 2-(N,N-dihexyl-dithiocarbamyl)-toluthiazole; 2-(alkyldithio)benzoxazoles such as 2-(octyldithio)benzoxazole, 2-(decyldithio)-benzoxazole and 2-(dodecyldithio)benzoxazole; benzoxazole derivatives of 2-(alkyldithio)toluoxazoles such as 2-(octyldithio)toluoxazole, 2-(decyldithio)toluoxazole, 2-(dodecyldithio)toluoxazole; 2,5-bis(alkyldithio)-1,3,4-thiadiazoles such as 2,5-bis(heptyldithio)-1,3,4-thiadiazole, 2,5-bis-(nonyldithio)-1,-3,4-thiadiazole, 2,5-bis(dodecyldithio)-1,3,4-thiadiazole and 2,5-bis-(octadecyldithio)-1,3,4-thiadiazole; 2,5-bis(N,N-dialkyl-dithiocarbamyl)-1,3,4-thiadiazoles such as 2,5-bis(N,N-diethyldithiocarbamyl)-1,3,-4-thiadiazole, 2,5-bis(N,N-dibutyldithiocarbamyl)-1,3,4-thiadiazole and 2,5-bis(N,N-dioctyldithiocarbamyl) 1,3,4-thiadiazole; thiadiazole derivatives of 2-N,N-dialkyldithiocarbamyl-5-mercapto-1,3,4-thiadiazoles such as 2-N,N-dibutyldithiocarbamyl-5-mercapto-1,3,4-thiadiazole and 2-N,N-dioctyl-dithiocarbamyl-5-mercapto-1,3,4-thiadiazole, and triazole derivatives of 1-alkyl-2,4-triazoles such as 1-dioctylaminomethyl-2,4-triazole; or concentrates and/or mixtures thereof.
Although their presence is not required to obtain the benefit of the present disclosure, the metal deactivator(s) and corrosion inhibitor(s) may be present from zero to about 1% by weight (e.g. from 0.01% to about 0.5% by weight) of the total composition of the present disclosure.
Antiwear Additive(s) or Inhibitor(s).
In any aspect or embodiment described herein, the composition of the present disclosure comprises at least one (e.g., 1, 2, 3, 4, 5, or 6, or more) antiwear additive or wear inhibitor. Any antiwear additive that is known or that becomes known may be utilized in the lubricating of the present disclosure. The antiwear additive may be an alkyldithiophosphate(s), aryl phosphate(s) and/or phosphite(s). The antiwear additive(s) may be essentially free of metals, or they may contain metal salts.
In certain embodiments, the antiwear additive is a phosphate ester or salt thereof. A phosphate ester or salt may be a monohydrocarbyl, dihydrocarbyl or a trihydrocarbyl phosphate, wherein each hydrocarbyl group is saturated. In an embodiment, each hydrocarbyl group independently contains from about 8 to about 30, or from about 12 up to about 28, or from about 14 up to about 24, or from about 14 up to about 18 carbons atoms. In an embodiment, the hydrocarbyl groups are alkyl groups. Examples of hydrocarbyl groups include at least one of tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl groups, and mixtures thereof.
A phosphate ester or salt is a phosphorus acid ester prepared by reacting at least one (e.g., 1, 2, 3, 4, or more) phosphorus acid or anhydride with a saturated alcohol. The phosphorus acid or anhydride cam be an inorganic phosphorus reagent, such as phosphorus pentoxide, phosphorus trioxide, phosphorus tetroxide, phosphorous acid, phosphoric acid, phosphorus halide, lower phosphorus esters, or a phosphorus sulfide, including phosphorus pentasulfide, and the like. Lower phosphorus acid esters may contain from 1 to about 7 carbon atoms in each ester group. Alcohols used to prepare the phosphorus acid esters or salts. Examples of commercially available alcohols and alcohol mixtures include Alfol 1218 (a mixture of synthetic, primary, straight-chain alcohols containing 12 to 18 carbon atoms); Alfol 20+ alcohols (mixtures of C18-C28 primary alcohols having mostly C20 alcohols as determined by GLC (gas-liquid-chromatography)); and Alfol22+ alcohols (C18-C28 primary alcohols containing primarily C22 alcohols). Alfol alcohols are available from, e.g., Continental Oil Company. Another example of a commercially available alcohol mixture is Adol 60 (about 75% by weight of a straight chain C22 primary alcohol, about 15% of a C20 primary alcohol, and about 8% of C18 and C24 alcohols). The Adol alcohols are marketed by Ashland Chemical.
The antiwear additive may include at least one (e.g., a mixture of) monohydric fatty alcohol. For example, a mixture of monohydric fatty alcohols derived from naturally occurring triglycerides and ranging in chain length from C8 to C18 may be utilized as an antiwear additive. A variety of monohydric fatty alcohol mixtures are available from Procter & Gamble Company. These mixtures contain various amounts of fatty alcohols containing 12, 14, 16, or 18 carbon atoms. For example, CO-1214 is a fatty alcohol mixture containing 0.5% of C10 alcohol, 66.0% of C12 alcohol, 26.0% of C14 alcohol and 6.5% of C16 alcohol.
Another group of commercially available alcohol mixtures include the “Neodol” products available from Shell Chemical Co. For example, Neodol 23 is a mixture of C12 and C13 alcohols; Neodol 25 is a mixture of C12 to C15 alcohols; and Neodol 45 is a mixture of C14 to C15 linear alcohols. The phosphate contains from about 14 to about 18 carbon atoms in each hydrocarbyl group. The hydrocarbyl groups of the phosphate may be derived from a mixture of fatty alcohols having from about 14 up to about 18 carbon atoms. The hydrocarbyl phosphate may also be derived from a fatty vicinal diol. Fatty vicinal diols include, but not limited to, those available from Ashland Oil under the general trade designation Adol 114 and Adol 158. The former is derived from a straight chain alpha olefin fraction of C11-C14, and the latter is derived from a C15-C18 fraction.
Phosphate salts may be prepared by reacting an acidic phosphate ester with an amine compound or a metallic base to form an amine or a metal salt. The amines may be monoamines or polyamines. Useful amines include those amines disclosed in U.S. Pat. No. 4,234,435.
Illustrative monoamines may contain a hydrocarbyl group, which contains from 1 to about 30 carbon atoms, or from 1 to about 12, or from 1 to about 6. Examples of primary monoamines useful in the present disclosure include methylamine, ethylamine, propylamine, butylamine, cyclopentylamine, cyclohexylamine, octylamine, dodecylamine, allylamine, cocoamine, stearylamine, and laurylamine. Examples of secondary monoamines include dimethylamine, diethylamine, dipropylamine, dibutylamine, dicyclopentylamine, dicyclohexylamine, methylbutylamine, ethylhexylamine, etc.
An amine may be a fatty (C8-C30) amine which includes n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine, oleyamine, etc. Also useful fatty amines include commercially available fatty amines, such as “Armeen” amines (products available from Akzo Chemicals, Chicago, Ill.), e.g. Armeen C, Armeen O, Armeen OL, Armeen T, Armeen HT, Armeen S and Armeen SD, wherein the letter designation relates to the fatty group, such as coco, oleyl, tallow, or stearyl groups.
Other useful amines include primary ether amines, such as those represented by the formula:
R″(OR′)xNH₂,
wherein:
R′ is a divalent alkylene group having about 2 to about 6 carbon atoms;
x is a number from one to about 150, or from about one to about five, or one; and
R″ is a hydrocarbyl group of about 5 to about 150 carbon atoms.
An exemplary or illustrative ether amine is available under the name SURFAM® amines produced and marketed by Mars Chemical Company, Atlanta, Ga. Additional exemplary ether amines include those identified as SURFAM P14B (decyloxypropylamine), SURFAM P16A (linear C16), and SURFAM P17B (tridecyloxypropylamine). The carbon chain lengths (i.e., C14, etc.) of the SURFAM ether amines described above and used hereinafter are approximate and include the oxygen ether linkage.
A further illustrative amine is a tertiary-aliphatic primary amine. For example, the aliphatic group, such as an alkyl group, contains from about 4 to about 30, or from about 6 to about 24, or from about 8 to about 22 carbon atoms. Usually the tertiary alkyl primary amines are monoamines the alkyl group is a hydrocarbyl group containing from one to about 27 carbon atoms. Such amines are illustrated by tert-butylamine, tert-hexylamine, 1-methyl-1-amino-cyclohexane, tert-octylamine, tert-decylamine, tert-dodecylamine, tert-tetradecylamine, tert-hexadecylamine, tert-octadecylamine, tert-tetracosanylamine, tert-octacosanylamine, and combinations thereof. Mixtures of tertiary aliphatic amines may also be used in preparing the phosphate salt. Illustrative of amine mixtures of this type are “Primene 81R”, which is a mixture of C11-C14 tertiary alkyl primary amines, and “Primene JMT”, which is a similar mixture of C18-C22 tertiary alkyl primary amines (both are available from Rohm and Haas Company). The tertiary aliphatic primary amines and methods for their preparation are known to those of ordinary skill in the art.
Another illustrative amine is a heterocyclic polyamine. The heterocyclic polyamines include aziridines, azetidines, azolidines, tetra- and dihydropyridines, pyrroles, indoles, piperidines, imidazoles, di- and tetra-hydroimidazoles, piperazines, isoindoles, purines, morpholines, thiomorpholines, N-aminoalkylmorpholines, N-aminoalkylthiomorpholines, N-aminoalkyl-piperazines, N,N′-diaminoalkylpiperazines, azepines, azocines, azonines, azecines and tetra-, di- and perhydro derivatives of each of the above, and mixtures of two or more (e.g., 2, 3, 4, 5, 6, or more) of these heterocyclic amines. In certain embodiments, the heterocyclic amines are saturated 5- and 6-membered heterocyclic amines containing only nitrogen, oxygen and/or sulfur in the hetero ring, especially the piperidines, piperazines, thiomorpholines, morpholines, pyrrolidines, and the like. Piperidine, aminoalkyl substituted piperidines, piperazine, aminoalkyl substituted piperazines, morpholine, aminoalkyl substituted morpholines, pyrrolidine, and aminoalkyl-substituted pyrrolidines, are especially preferred. Usually the aminoalkyl substituents are substituted on a nitrogen atom forming part of the hetero ring. Specific examples of such heterocyclic amines include N-aminopropylmorpholine, N-aminoethylpiperazine, and N,N′-diaminoethylpiperazine. Hydroxy heterocyclic polyamines are also useful. Examples include N-(2-hydroxyethyl)cyclohexylamine, 3-hydroxycyclopentylamine, parahydroxyaniline, N-hydroxyethylpiperazine, and the like.
The metal salts of the phosphorus acid esters may be prepared by the reaction of a metal base with the acidic phosphorus ester. The metal base may be any metal compound capable of forming a metal salt. Examples of metal bases include metal oxides, hydroxides, carbonates, sulfates, borates, or the like. The metals of the metal base include Group IA, IIA, IB through VIIB, and VIII metals (CAS version of the Periodic Table of the Elements). These metals include the alkali metals, alkaline earth metals and transition metals. In an embodiment, the metal is a Group IIA metal, such as calcium or magnesium, Group IIB metal, such as zinc, or a Group VIIB metal, such as manganese. In particular embodiments, the metal is magnesium, calcium, manganese or zinc. Examples of metal compounds which may be reacted with the phosphorus acid include zinc hydroxide, zinc oxide, copper hydroxide, copper oxide, etc.
The composition of the present disclosure also may include a fatty imidazoline or a reaction product of a fatty carboxylic acid and at least one polyamine. The fatty imidazoline has fatty substituents containing from 8 to about 30, or from about 12 to about 24 carbon atoms. The substituent may be saturated or unsaturated, for example, heptadeceneyl derived olyel groups. In a particular embodiment, the substituents are saturated. In one aspect, the fatty imidazoline may be prepared by reacting a fatty carboxylic acid with a polyalkylenepolyamine. The fatty carboxylic acids are can be mixtures of straight and branched chain fatty carboxylic acids containing about 8 to about 30 carbon atoms, or from about 12 to about 24, or from about 16 to about 18. Carboxylic acids include the polycarboxylic acids or carboxylic acids or anhydrides having from 2 to about 4 carbonyl groups, (e.g. 2 carbonyl groups). The polycarboxylic acids include succinic acids and anhydrides and Diels-Alder reaction products of unsaturated monocarboxylic acids with unsaturated carboxylic acids (such as acrylic, methacrylic, maleic, fumaric, crotonic and itaconic acids). In particular embodiments, the fatty carboxylic acids are fatty monocarboxylic acids, having from about 8 to about 30, (e.g. about 12 to about 24 carbon atoms), such as octanoic, oleic, stearic, linoleic, dodecanoic, and tall oil acids. In an embodiment, the fatty carboxylic acid is stearic acid. The fatty carboxylic acid or acids are reacted with at least one polyamine. The polyamines may be aliphatic, cycloaliphatic, heterocyclic or aromatic. Examples of the polyamines include alkylene polyamines and heterocyclic polyamines.
The antiwear additive according to the present disclosure has very high effectiveness when used in low concentrations and is free of chlorine. For the neutralization of the phosphoric esters, the latter are taken and the corresponding amine slowly added with stirring. The resulting heat of neutralization is removed by cooling. The antiwear additive according to the present disclosure can be incorporated into the respective base liquid with the aid of fatty substances (e.g., tall oil fatty acid, oleic acid, etc.) as solubilizers. The base liquids used are napthenic or paraffinic base oils, synthetic oils (e.g., polyglycols, mixed polyglycols), polyolefins, carboxylic esters, etc.
In further embodiments, the compositions of the present disclosure can contain at least one phosphorus containing antiwear additive. Examples of such additives are amine phosphate antiwear additives such as that known under the trade name IRGALUBE 349 and/or triphenyl phosphorothionate antiwear additives, such as that known under the trade name IRGALUBE TPPT. Such amine phosphates may be present in an amount of from about 0.01 to about 2% (e.g. about 0.2 to about 1.5%) by weight of the lubricant composition, while such phosphorothionates are suitably present in an amount of from about 0.01 to about 3% (e.g., about 0.5 to about 1.5%) by weight of the composition of the present disclosure. A mixture of an amine phosphate and phosphorothionate may be employed.
Neutral organic phosphates may be present in an amount from zero to about 4% (e.g., about 0.1 to about 2.5%) by weight of the composition of the present disclosure. The above amine phosphates can be mixed together to form a single component capable of delivering antiwear performance. The neutral organic phosphate is also a conventional ingredient of lubricating oils.
Phosphates for use in the present disclosure include phosphates, acid phosphates, phosphites, and acid phosphites. The phosphates include triaryl phosphates, trialkyl phosphates, trialkylaryl phosphates, triarylalkyl phosphates, trialkenyl phosphates, or combinations thereof. As specific examples of these, referred to are triphenyl phosphate, tricresyl phosphate, benzyldiphenyl phosphate, ethyldiphenyl phosphate, tributyl phosphate, ethyldibutyl phosphate, cresyldiphenyl phosphate, dicresylphenyl phosphate, ethylphenyldiphenyl phosphate, diethylphenylphenyl phosphate, propylphenyldiphenyl phosphate, dipropylphenylphenyl phosphate, triethylphenyl phosphate, tripropylphenyl phosphate, butylphenyldiphenyl phosphate, dibutylphenylphenyl phosphate, tributylphenyl phosphate, trihexyl phosphate, tri(2-ethylhexyl) phosphate, tridecyl phosphate, trilauryl phosphate, trimyristyl phosphate, tripalmityl phosphate, tristearyl phosphate, trioleyl phosphate, or combinations thereof.
The acid phosphates include, for example, 2-ethylhexyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, isodecyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, stearyl acid phosphate, isostearyl acid phosphate, or combinations thereof.
The phosphites include, for example, triethyl phosphite, tributyl phosphite, triphenyl phosphite, tricresyl phosphite, tri(nonylphenyl) phosphite, tri(2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite, triisooctyl phosphite, diphenylisodecyl phosphite, tristearyl phosphite, trioleyl phosphite, or combinations thereof.
The acid phosphites include, for example, dibutyl hydrogenphosphite, dilauryl hydrogenphosphite, dioleyl hydrogenphosphite, distearyl hydrogenphosphite, diphenyl hydrogenphosphite, or combinations thereof.
Amines that form amine salts with such phosphates include, for example, mono-substituted amines, di-substituted amines and tri-substituted amines. Examples of the mono-substituted amines include butylamine, pentylamine, hexylamine, cyclohexylamine, octylamine, laurylamine, stearylamine, oleylamine and benzylamine; and those of the di-substituted amines include dibutylamine, dipentylamine, dihexylamine, dicyclohexylamine, dioctylamine, dilaurylamine, distearylamine, dioleylamine, dibenzylamine, stearyl monoethanolamine, decyl monoethanolamine, hexyl monopropanolamine, benzyl monoethanolamine, phenyl monoethanolamine, and tolyl monopropanolamine. Examples of tri-substituted amines include tributylamine, tripentylamine, trihexylamine, tricyclohexylamine, trioctylamine, trilaurylamine, tristearylamine, trioleylamine, tribenzylamine, dioleyl monoethanolamine, dilauryl monopropanolamine, dioctyl monoethanolamine, dihexyl monopropanolamine, dibutyl monopropanolamine, oleyl diethanolamine, stearyl dipropanolamine, lauryl diethanolamine, octyl dipropanolamine, butyl diethanolamine, benzyl diethanolamine, phenyl diethanolamine, tolyl dipropanolamine, xylyl diethanolamine, triethanolamine, and tripropanolamine. Phosphates or their amine salts are added to the base oil in an amount from zero to about 5% by weight, (e.g. from about 0.1 to about 2% by weight) relative to the total weight of the composition of the present disclosure.
Illustrative carboxylic acids to be reacted with amines include, for example, aliphatic carboxylic acids, dicarboxylic acids (dibasic acids), aromatic carboxylic acids, or combinations thereof. The aliphatic carboxylic acids have from 8 to 30 carbon atoms, and may be saturated or unsaturated, and linear or branched. Specific examples of the aliphatic carboxylic acids include pelargonic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, isostearic acid, eicosanoic acid, behenic acid, triacontanoic acid, caproleic acid, undecylenic acid, oleic acid, linolenic acid, erucic acid, linoleic acid, or combinations thereof. Specific examples of the dicarboxylic acids include octadecylsuccinic acid, octadecenylsuccinic acid, adipic acid, azelaic acid, sebacic acid, or combinations thereof. One example of the aromatic carboxylic acids is salicylic acid. Illustrative amines to be reacted with carboxylic acids include, for example, polyalkylene-polyamines, such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine, dipropylenetriamine, tetrapropylenepentamine, hexabutyleneheptamine, or combinations thereof; and alkanolamines, such as monoethanolamine and diethanolamine. Of these, preferred are a combination of isostearic acid, tetraethylenepentamine, or combinations thereof; and a combination of oleic acid and diethanolamine. Reaction products of carboxylic acids and amines may be added to the base oil in an amount of from zero to about 5% by weight (e.g. from about 0.03 to about 3% by weight) relative to the total weight of the composition of the present disclosure.
Other illustrative antiwear additives include phosphites, thiophosphites, phosphates, and thiophosphates, including mixed materials having, for instance, one or two sulfur atoms, i.e., monothio- or dithio compounds. 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 primarily composed of carbon and hydrogen atoms and is attached to the remainder of the molecule through a carbon atom and does not exclude the presence of other atoms or groups in a proportion insufficient to detract from the molecule having a predominantly hydrocarbon character. In general, no more than two, preferably no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; typically, there will be no non-hydrocarbon substituents in the hydrocarbyl group. A more detailed definition of the terms “hydrocarbyl substituent” or “hydrocarbyl group,” is described in U.S. Pat. No. 6,583,092.
Specific examples of some phosphites and thiophosphites within the scope of the disclosure include phosphorous acid, mono-, di- or tri-thiophosphorous acid, mono-, di- or tri-propyl phosphite or mono-, di- or tri-thiophosphite; mono-, di- or tri-butyl phosphite or mono-, di- or tri-thiophosphite; mono-, di- or tri-amyl phosphite or mono-, di- or tri-thiophosphite; mono-, di- or tri-hexyl phosphite; or mono-, di- or tri-thiophosphite; mono-, di- or tri-phenyl phosphite; or mono-, di- or tri-thiophosphite; mono-, di- or tri-tolyl phosphite; or mono-, di- or tri-thiophosphite; mono-, di- or tri-cresyl phosphite; or mono-, di- or tri-thiophosphite; dibutyl phenyl phosphite; or mono-, di- or tri-phosphite; amyl dicresyl phosphite; or mono-, di- or tri-thiophosphite, and any of the above with substituted groups, such as chlorophenyl or chlorobutyl.
Specific examples of the phosphates and thiophosphates within the scope of the disclosure include phosphoric acid, mono-, di-, or tri-thiophosphoric acid, mono-, di-, or tri-propyl phosphate or mono-, di-, or tri-thiophosphate; mono-, di-, or tri-butyl phosphate or mono-, di-, or tri-thiophosphate; mono-, di-, or tri-amyl phosphate or mono-, di-, or tri-thiophosphate; mono-, di-, or tri-hexyl phosphate or mono-, di-, or tri-thiophosphate; mono-, di-, or tri-phenyl phosphate or mono-, di-, or tri-thiophosphate; mono-, di-, or tritolyl phosphate or mono-, di-, or trithiophosphate; mono-, di-, or tri-cresyl phosphate or mono-, di-, or tri-thiophosphate; dibutyl phenyl phosphate or mono-, di-, or tri-phosphate, amyl dicresyl phosphate or mono-, di-, or tri-thiophosphate, and any of the above with substituted groups, such as chlorophenyl or chlorobutyl.
These phosphorus compounds may be prepared by well-known reactions. For example, the reaction of an alcohol or a phenol with phosphorus trichloride or by a transesterification reaction. Alcohols and phenols can be reacted with phosphorus pentoxide to provide a mixture of an alkyl or aryl phosphoric acid and a dialkyl or diaryl phosphoric acid. Alkyl phosphates can also be prepared by the oxidation of the corresponding phosphites. Thiophosphates can be prepared by the reaction of phosphites with elemental sulfur. In any case, the reaction can be conducted with moderate heating. Moreover, various phosphorus esters can be prepared by reaction using other phosphorus esters as starting materials. Thus, medium chain (C9 to C22) phosphorus esters have been prepared by reaction of dimethylphosphite with a mixture of medium-chain alcohols by means of a thermal transesterification or an acid- or base-catalyzed transesterification. See, for example, U.S. Pat. No. 4,652,416. Most such materials are also commercially available; for instance, triphenyl phosphite is available from Albright and Wilson as Duraphos TPP™; di-n-butyl hydrogen phosphite from Albright and Wilson as Duraphos DBHP™; and triphenylthiophosphate from Ciba Specialty Chemicals as Irgalube TPPT™.
Examples of esters of the dialkylphosphorodithioic acids include esters obtained by reaction of the dialkyl phosphorodithioic acid with an alpha, beta-unsaturated carboxylic acid (e.g., methyl acrylate) and, optionally an alkylene oxide such as propylene oxide.
One or more of the above-identified metal dithiophosphates may be used from about zero to about 2% by weight (e.g., from about 0.1 to about 1% by weight) based on the weight of the total composition.
The hydrocarbyl in the dithiophosphate may be alkyl, cycloalkyl, aralkyl or alkaryl groups, or a substantially hydrocarbon group of similar structure. Illustrative alkyl groups include isopropyl, isobutyl, n-butyl, sec-butyl, the various amyl groups, n-hexyl, methylisobutyl, heptyl, 2-ethylhexyl, diisobutyl, isooctyl, nonyl, behenyl, decyl, dodecyl, tridecyl, etc. Illustrative lower alkylphenyl groups include butylphenyl, amylphenyl, heptylphenyl, etc. Cycloalkyl groups likewise are useful and these include chiefly cyclohexyl and the lower alkyl-cyclohexyl radicals. Many substituted hydrocarbon groups may also be used, e.g., chloropentyl, dichlorophenyl, and dichlorodecyl.
The phosphorodithioic acids from which the metal salts useful in this disclosure are prepared are well known. Examples of dihydrocarbylphosphorodithioic acids and metal salts, and processes for preparing such acids and salts are found in, for example U.S. Pat. Nos. 4,263,150; 4,289,635; 4,308,154; and 4,417,990. These patents are hereby incorporated by reference.
The phosphorodithioic acids may be prepared by the reaction of a phosphorus sulfide with an alcohol or phenol or mixtures of alcohols. An exemplary reaction involves four moles of the alcohol or phenol and one mole of phosphorus pentasulfide, and may be carried out within the temperature range from about 50° C. to about 200° C. Thus, the preparation of O,O-di-n-hexyl phosphorodithioic acid involves the reaction of a mole of phosphorus pentasulfide with four moles of n-hexyl alcohol at about 100° C. for about two hours. Hydrogen sulfide is liberated and the residue is the desired acid. The preparation of the metal salts of these acids may be effected by reaction with metal compounds as well known in the art.
The metal salts of dihydrocarbyldithiophosphates, which are useful in the present disclosure, include those salts containing Group I metals, Group II metals, aluminum, lead, tin, molybdenum, manganese, cobalt, and nickel. The Group II metals, aluminum, tin, iron, cobalt, lead, molybdenum, manganese, nickel and copper are among the preferred metals. Zinc and copper are especially useful metals. Examples of metal compounds which may be reacted with the acid include lithium oxide, lithium hydroxide, sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, silver oxide, magnesium oxide, magnesium hydroxide, calcium oxide, zinc hydroxide, strontium hydroxide, cadmium oxide, cadmium hydroxide, barium oxide, aluminum oxide, iron carbonate, copper hydroxide, lead hydroxide, tin butylate, cobalt hydroxide, nickel hydroxide, nickel carbonate, and the like.
In some instances, the incorporation of certain ingredients such as small amounts of the metal acetate or acetic acid in conjunction with the metal reactant will facilitate the reaction and result in an improved product. For example, the use of up to about 5% of zinc acetate in combination with the required amount of zinc oxide facilitates the formation of a zinc phosphorodithioate with potentially improved performance properties.
Especially useful metal phosphorodithloates can be prepared from phosphorodithloic acids, which in turn are prepared by the reaction of phosphorus pentasulfide with mixtures of alcohols. In addition, the use of such mixtures enables the utilization of less expensive alcohols, which individually may not yield oil-soluble phosphorodithioic acids. Thus, a mixture of isopropyl and hexylalcohols can be used to produce a very effective, oil-soluble metal phosphorodithioate. For the same reason mixtures of phosphorodithioic acids can be reacted with the metal compounds to form less expensive, oil-soluble salts.
The mixtures of alcohols may be mixtures of different primary alcohols, mixtures of different secondary alcohols, or mixtures of primary and secondary alcohols. Examples of useful mixtures include: n-butanol and n-octanol; n-pentanol and 2-ethyl-1-hexanol; isobutanol and n-hexanol; isobutanol and isoamyl alcohol; isopropanol and 2-methyl-4-pentanol; isopropanol and sec-butyl alcohol; isopropanol and isooctyl alcohol; and the like.
Organic triesters of phosphorus acids are also employed in lubricants. Exemplary esters include triarylphosphates, trialkyl phosphates, neutral alkylaryl phosphates, alkoxyalkyl phosphates, triaryl phosphite, trialkylphosphite, neutral alkyl aryl phosphites, neutral phosphonate esters and neutral phosphine oxide esters. In one embodiment, the long chain dialkyl phosphonate esters are used. For example, the dimethyl-, diethyl-, and/or dipropyl-oleyl phosphonates can be used. Neutral acids of phosphorus acids are the triesters rather than an acid (HO-P) or a salt of an acid.
Any C4 to C8 alkyl or higher phosphate ester may be employed in the disclosure. For example, tributyl phosphate (TBP) and tri isooctal phosphate (TOF) can be used. The specific triphosphate ester or combination of esters can easily be selected by one skilled in the art to adjust the density, viscosity, etc., of the formulated fluid. Mixed esters, such as dibutyl octyl phosphate or the like may be employed rather than a mixture of two or more trialkyl phosphates.
A trialkyl phosphate is often useful to adjust the specific gravity of the formulation, but it is desirable that the specific trialkyl phosphate be a liquid at low temperatures. Consequently, a mixed ester containing at least one partially alkylated with a C3 to C4 alkyl group is very desirable, for example, 4-isopropylphenyl diphenyl phosphate or 3-butylphenyl diphenyl phosphate. Even more desirable is a triaryl phosphate produced by partially alkylating phenol with butylene or propylene to form a mixed phenol which is then reacted with phosphorus oxychloride as taught in U.S. Pat. No. 3,576,923.
Any mixed triaryl phosphate (TAP) esters may be used as cresyl diphenyl phosphate, tricresyl phosphate, mixed xylyl cresyl phosphates, lower alkylphenyl/phenyl phosphates, such as mixed isopropylphenyl/phenyl phosphates, t-butylphenyl phenyl phosphates. These esters are used extensively as plasticizers, functional fluids, gasoline additives, flame-retardant additives and the like.
A metal alkylthiophosphate and more particularly a metal dialkyl dithio phosphate in which the metal constituent is zinc, or zinc dialkyl dithio phosphate (ZDDP) can be a useful component of the lubricating oils of this disclosure. ZDDP can be derived from primary alcohols, secondary alcohols or mixtures thereof. ZDDP compounds are of the formula:
Zn[SP(S)(OR1)(OR2)]₂,
wherein R1 and R2 are C1-C18 alkyl groups (e.g. C2-C12 alkyl groups).
These alkyl groups may be straight chain or branched. Alcohols used in the ZDDP can be propanol, 2-propanol, butanol, secondary butanol, pentanols, hexanols such as 4-methyl-2-pentanol, n-hexanol, n-octanol, 2-ethyl hexanol, alkylated phenols, and the like. Mixtures of secondary alcohols or of primary and secondary alcohol can be utilized. Alkyl aryl groups may also be used.
Exemplary zinc dithiophosphates that are commercially available include secondary zinc dithiophosphates, such as those available from for example, The Lubrizol Corporation under the trade designations “LZ 677A”, “LZ 1095” and “LZ 1371”, from for example Chevron Oronite under the trade designation “OLOA 262”, and from for example Afton Chemical under the trade designation “HITEC 7169”.
ZDDP may be used in amounts of from about zero to about 3 weight percent (e.g. from about 0.05 weight percent to about 2 weight percent, from about 0.1 weight percent to about 1.5 weight percent, or from about 0.1 weight percent to about 1 weight percent) based on the total weight of the composition for the present disclosure, although more or less can often be used advantageously. A secondary ZDDP may be present in an amount of from zero to about 1 weight percent of the total weight of the composition for the present disclosure.
Extreme Pressure Agent(s).
In any aspect or embodiment described herein, the composition of the present disclosure comprises at least one (e.g., 1, 2, 3, or 4, or more) extreme pressure agent. Any extreme pressure agent that is known or that becomes know may be utilized in the composition of the present disclosure.
The extreme pressure agents can be at least one sulfur-based extreme pressure agents, such as sulfides, sulfoxides, sulfones, thiophosphinates, thiocarbonates, sulfurized fats and oils, sulfurized olefins, the like, or combinations thereof; at least one phosphorus-based extreme pressure agents, such as phosphoric acid esters (e.g., tricresyl phosphate (TCP) and the like), phosphorous acid esters, phosphoric acid ester amine salts, phosphorous acid ester amine salts, the like, or combinations thereof; halogen-based extreme pressure agents, such as chlorinated hydrocarbons, the like, or combinations thereof; organometallic extreme pressure agents, such as thiophosphoric acid salts (e.g., zinc dithiophosphate (ZnDTP) and the like), thiocarbamic acid salts, or combinations thereof; and the like.
The phosphoric acid ester, thiophosphoric acid ester, and amine salts thereof functions to enhance the lubricating performances, and can be selected from known compounds conventionally employed as extreme pressure agents. For example, phosphoric acid esters, a thiophosphoric acid ester, or an amine salt thereof which has an alkyl group, an alkenyl group, an alkylaryl group, or an aralkyl group, any of which contains approximately 3 to 30 carbon atoms, may be employed.
Examples of the phosphoric acid esters include aliphatic phosphoric acid esters such as triisopropyl phosphate, tributyl phosphate, ethyl dibutyl phosphate, trihexyl phosphate, tri-2-ethylhexyl phosphate, trilauryl phosphate, tristearyl phosphate, and trioleyl phosphate; and aromatic phosphoric acid esters such as benzyl phenyl phosphate, allyl diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, ethyl diphenyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, ethylphenyl diphenyl phosphate, diethylphenyl phenyl phosphate, propylphenyl diphenyl phosphate, dipropylphenyl phenyl phosphate, triethylphenyl phosphate, tripropylphenyl phosphate, butylphenyl diphenyl phosphate, dibutylphenyl phenyl phosphate, and tributylphenyl phosphate. In an embodiment, the phosphoric acid ester is a trialkylphenyl phosphate.
Examples of the thiophosphoric acid esters include aliphatic thiophosphoric acid esters such as triisopropyl thiophosphate, tributyl thiophosphate, ethyl dibutyl thiophosphate, trihexyl thiophosphate, tri-2-ethylhexyl thiophosphate, trilauryl thiophosphate, tristearyl thiophosphate, and trioleyl thiophosphate; and aromatic thiophosphoric acid esters such as benzyl phenyl thiophosphate, allyl diphenyl thiophosphate, triphenyl thiophosphate, tricresyl thiophosphate, ethyl diphenyl thiophosphate, cresyl diphenyl thiophosphate, dicresyl phenyl thiophosphate, ethylphenyl diphenyl thiophosphate, diethylphenyl phenyl thiophosphate, propylphenyl diphenyl thiophosphate, dipropylphenyl phenyl thiophosphate, triethylphenyl thiophosphate, tripropylphenyl thiophosphate, butylphenyl diphenyl thiophosphate, dibutylphenyl phenyl thiophosphate, and tributylphenyl thiophosphate. In an embodiment, the thiophosphoric acid ester is a trialkylphenyl thiophosphate.
Also employable are amine salts of the above-mentioned phosphates and thiophosphates. Amine salts of acidic alkyl or aryl esters of the phosphoric acid and thiophosphoric acid are also employable. In an embodiment, the amine salt is an amine salt of trialkylphenyl phosphate or an amine salt of alkyl phosphate.
One or any combination of the compounds selected from the group consisting of a phosphoric acid ester, a thiophosphoric acid ester, and an amine salt thereof may be used.
The phosphorus acid ester and/or its amine salt function to enhance the lubricating performance of the composition, and can be selected from known compounds conventionally employed as extreme pressure agents. For example, the extreme pressure agent can be a phosphorus acid ester or an amine salt thereof, which has an alkyl group, an alkenyl group, an alkylaryl group, or an aralkyl group, any of which contains approximately 3 to 30 carbon atoms.
Examples of phosphorus acid esters that may be used includes aliphatic phosphorus acid esters, such as triisopropyl phosphite, tributyl phosphite, ethyl dibutyl phosphite, trihexyl phosphite, tri-2-ethylhexylphosphite, trilauryl phosphite, tristearyl phosphite, and trioleyl phosphite; and aromatic phosphorus acid esters such as benzyl phenyl phosphite, allyl diphenylphosphite, triphenyl phosphite, tricresyl phosphite, ethyl diphenyl phosphite, tributyl phosphite, ethyl dibutyl phosphite, cresyl diphenyl phosphite, dicresyl phenyl phosphite, ethylphenyl diphenyl phosphite, diethylphenyl phenyl phosphite, propylphenyl diphenyl phosphite, dipropylphenyl phenyl phosphite, triethylphenyl phosphite, tripropylphenyl phosphite, butylphenyl diphenyl phosphite, dibutylphenyl phenyl phosphite, and tributylphenyl phosphite. Also favorably employed are dilauryl phosphite, dioleyl phosphite, dialkyl phosphites, and diphenyl phosphite. In certain embodiments, the phosphorus acid ester is a dialkyl phosphite or a trialkyl phosphite.
The phosphate salt may be derived from a polyamine, such as alkoxylated diamines, fatty polyamine diamines, alkylenepolyamines, hydroxy containing polyamines, condensed polyamines arylpolyamines, and heterocyclic polyamines. Examples of these amines include Ethoduomeen T/13 and T/20, which are ethylene oxide condensation products of N-tallowtrimethylenediamine containing 3 and 10 moles of ethylene oxide per mole of diamine, respectively.
In another embodiment, the polyamine is a fatty diamine. The fatty diamine may include mono- or dialkyl, symmetrical or asymmetrical ethylene diamines, propane diamines (1,2 or 1,3), and polyamine analogs of the above. Suitable commercial fatty polyamines are Duomeen C (N-coco-1,3-diaminopropane), Duomeen S (N-soya-1,3-diaminopropane), Duomeen T (N-tallow-1,3-diaminopropane), and Duomeen O (N-oleyl-1,3-diaminopropane). “Duomeens” are commercially available from Armak Chemical Co., Chicago, Ill.
Such alkylenepolyamines include methylenepolyamines, ethylenepolyamines, butylenepolyamines, propylenepolyamines, pentylenepolyamines, etc. The higher homologs and related heterocyclic amines, such as piperazines and N-amino alkyl-substituted piperazines, are also included. Specific examples of such polyamines are ethylenediamine, triethylenetetramine, tris-(2-aminoethyl)amine, propylenediamine, trimethylenediamine, tripropylenetetramine, tetraethylenepentamine, hexaethyleneheptamine, pentaethylenehexamine, etc. Higher homologs obtained by condensing two or more of the above-noted alkyleneamines are similarly useful as are mixtures of two or more of the aforedescribed polyamines.
In one embodiment the polyamine is an ethylenepolyamine. Such polyamines are described in detail under the heading Ethylene Amines in Kirk Othmer's “Encyclopedia of Chemical Technology”, 2nd Edition, Vol. 7, pages 22-37, Interscience Publishers, New York (1965). Ethylenepolyamines can be a complex mixture of polyalkylenepolyamines, including cyclic condensation products.
Other useful types of polyamine mixtures are those resulting from stripping of the above-described polyamine mixtures to leave, as residue, what is often termed “polyamine bottoms”. The alkylenepolyamine bottoms can be characterized as having less than 2%, usually less than 1% (by weight) material boiling below about 200° C. An exemplary sample of such ethylene polyamine bottoms obtained from the Dow Chemical Company of Freeport, Tex. designated “E-100”. These alkylenepolyamine bottoms include cyclic condensation products, such as piperazine, and higher analogs of diethylenetriamine, triethylenetetramine and the like. These alkylenepolyamine bottoms can be reacted solely with the acylating agent or they can be used with other amines, polyamines, or mixtures thereof. Another useful polyamine is a condensation reaction between at least one hydroxy compound with at least one polyamine reactant containing at least one primary or secondary amino group. In an embodiment, the hydroxy compounds are alcohols and amines. The polyhydric alcohols are described below. In one embodiment, the hydroxy compounds are polyhydric amines. Polyhydric amines include any of the above-described monoamines reacted with an alkylene oxide (e.g., ethylene oxide, propylene oxide, butylene oxide, etc.) having from two to about 20 carbon atoms, or from two to about four. Examples of polyhydric amines include tri-(hydroxypropyl)amine, tris-(hydroxymethyl)amino methane, 2-amino-2-methyl-1,3-propanediol, N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine, and N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine. IN an embodiment, the polyhydric amin is tris(hydroxymethyl)aminomethane (THAM).
Polyamines which react with the polyhydric alcohol or amine to form the condensation products or condensed amines, are described above. In an embodiment, the polyamine include at least one of triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and mixtures of polyamines, such as the above-described “amine bottoms”.
In some embodiments, the extreme pressure additive or additives includes sulphur-based extreme pressure additives, such as dialkyl sulphides, dibenzyl sulphide, dialkyl polysulphides, dibenzyl disulphide, alkyl mercaptans, dibenzothiophene, 2,2′-dithiobis(benzothiazole), or combinations thereof; phosphorus-based extreme pressure additives, such as trialkyl phosphates, triaryl phosphates, trialkyl phosphonates, trialkyl phosphites, triaryl phosphites, dialkylhydrozine phosphites, or combinations thereof; and/or phosphorus- and sulphur-based extreme pressure additives, such as zinc dialkyldithiophosphates, dialkylthiophosphoric acid, trialkyl thiophosphate esters, acidic thiophosphate esters, trialkyl trithiophosphates, or combinations thereof. Extreme pressure additives can be used individually or in the form of mixtures, conveniently in an amount within the range from zero to about 2% by weight of the composition of the present disclosure.
Dispersant(s).
In other embodiments, the composition of the present disclosure comprises at least one (e.g., 1, 2, 3, or 4, or more) dispersant. During machine operation, oil-insoluble oxidation byproducts are produced. The dispersant may be added to help keep these byproducts in solution, thus diminishing their deposition on metal surfaces. Any dispersant that is known or that becomes know may be utilized in the composition of the present disclosure. The dispersant may be present in an amount of ≤about 1.5 wt. %, ≤about 1.25 wt. %, or ≤about 1 wt. %. For example, the dispersant may be present in an amount of about 0.1 to about 1.5 wt. %, about 0.1 to about 1.25 wt. %, about 0.1 to about 1 wt. %, about 0.1 to about 0.5 wt. %, about 0.25 to about 1.5 wt. %, about 0.25 to about 1.25 wt. %, about 0.5 to about 1 wt. %, about 0.5 to about 1.5 wt. %, about 0.5 to about 1.25 wt. %, about 0.5 to about 1 wt. %, about 0.75 to about 1.5 wt. %, about 0.75 to about 1.25 wt. %, or about 1 to about 1.5 wt. %.
In some embodiments, the dispersants is ashless or ash-forming in nature. In an embodiment, the dispersant is an ashless. So called ashless are organic materials that form substantially no ash upon combustion. For example, non-metal-containing or borated metal-free dispersants are considered ashless. In contrast, metal-containing detergents form ash upon combustion.
Suitable dispersants may contain a polar group attached to a relatively high molecular weight hydrocarbon chain (e.g., about 50 to about 400 carbon atoms). In certain embodiments, the polar group contains at least one element of nitrogen, oxygen, or phosphorus.
A particularly useful class of dispersants are the (poly)alkenylsuccinic derivatives, which may be produced by the reaction of a long chain hydrocarbyl substituted succinic compound, e.g. a hydrocarbyl substituted succinic anhydride, with a polyhydroxy or polyamino compound. The long chain hydrocarbyl group constituting the oleophilic portion of the molecule, which confers solubility in the oil, is normally a polyisobutylene group. Many examples of this type of dispersant are well known commercially and in the literature. Exemplary U.S. patents describing such dispersants are U.S. Pat. Nos. 3,172,892; 3,2145,707; 3,219,666; 3,316,177; 3,341,542; 3,444,170; 3,454,607; 3,541,012; 3,630,904; 3,632,511; 3,787,374 and 4,234,435. Other types of dispersant are described in U.S. Pat. Nos. 3,036,003; 3,200,107; 3,254,025; 3,275,554; 3,438,757; 3,454,555; 3,565,804; 3,413,347; 3,697,574; 3,725,277; 3,725,480; 3,726,882; 4,454,059; 3,329,658; 3,449,250; 3,519,565; 3,666,730; 3,687,849; 3,702,300; 4,100,082; 5,705,458. A further description of dispersants may be found, for example, in European Patent Application No. 471 071, to which reference is made for this purpose.
Hydrocarbyl-substituted succinic acid and hydrocarbyl-substituted succinic anhydride derivatives are useful dispersants. In particular, succinimide, succinate esters, or succinate ester amides prepared by the reaction of a hydrocarbon-substituted succinic acid compound (e.g., a hydrocarbon-substituted succinic acid compound having at least 50 carbon atoms in the hydrocarbon substituent) with at least one equivalent of an alkylene amine are particularly useful.
Succinimides are formed by the condensation reaction between hydrocarbyl substituted succinic anhydrides and amines. Molar ratios can vary depending on the polyamine. For example, the molar ratio of hydrocarbyl substituted succinic anhydride to TEPA can vary from about 1:1 to about 5:1. Representative examples are shown in U.S. Pat. Nos. 3,087,936; 3,172,892; 3,219,666; 3,272,746; 3,322,670; and 3,652,616, 3,948,800; and Canada Patent No. 1,094,044.
Succinate esters may be formed by the condensation reaction between hydrocarbyl substituted succinic anhydrides and alcohols or polyols. Molar ratios can vary depending on the alcohol or polyol used. For example, the condensation product of a hydrocarbyl substituted succinic anhydride and pentaerythritol is a useful dispersant.
Succinate ester amides may be formed by condensation reaction between hydrocarbyl substituted succinic anhydrides and alkanol amines. For example, suitable alkanol amines include ethoxylated polyalkylpolyamines, propoxylated polyalkylpolyamines and polyalkenylpolyamines, such as polyethylene polyamines. One example is propoxylated hexamethylenediamine. Representative examples are shown in U.S. Pat. No. 4,426,305.
The molecular weight of the hydrocarbyl substituted succinic anhydrides used in the preceding paragraphs can range between about 800 and about 2,500 or more. The above products can be post-reacted with various reagents such as sulfur, oxygen, formaldehyde, carboxylic acids, such as oleic acid. The above products can also be post reacted with boron compounds, such as boric acid, borate esters or highly borated dispersants, to form borated dispersants, which may have from about 0.1 to about 5 moles of boron per mole of dispersant reaction product.
Mannich base dispersants are made from the reaction of alkylphenols, formaldehyde, and amines. See U.S. Pat. No. 4,767,551, which is incorporated herein by reference. Process aids and catalysts, such as oleic acid and sulfonic acids, can also be part of the reaction mixture. Molecular weights of the alkylphenols may range from about 800 to about 2,500. Representative examples are shown in U.S. Pat. Nos. 3,697,574; 3,703,536; 3,704,308; 3,751,365; 3,756,953; 3,798,165; and 3,803,039.
High molecular weight aliphatic acid modified Mannich condensation products useful in this disclosure can be prepared from high molecular weight alkyl-substituted hydroxyaromatics or HNR₂group-containing reactants, wherein each R is independently selected from hydrogen, C1-C18 alkyl, aryl, alkenyl, alkaryl group.
Hydrocarbyl substituted amine ashless dispersant additives are well known to one skilled in the art; see, for example, U.S. Pat. Nos. 3,275,554; 3,438,757; 3,565,804; 3,755,433, 3,822,209, and 5,084,197.
In certain embodiments, the dispersants include borated and/or non-borated succinimides, including those derivatives from mono-succinimides, bis-succinimides, and/or mixtures of mono- and bis-succinimides, wherein the hydrocarbyl succinimide is derived from a hydrocarbylene group such as polyisobutylene having a Mn of from about 500 to about 5000, or from about 1000 to about 3000, or about 1000 to about 2000, or a mixture of such hydrocarbylene groups, often with high terminal vinylic groups. Other dispersants include succinic acid-esters and amides, alkylphenol-polyamine-coupled Mannich adducts, their capped derivatives, and other related components.
Polymethacrylate or polyacrylate derivatives are another class of dispersants. These dispersants may be prepared by reacting a nitrogen containing monomer and a methacrylic or acrylic acid esters containing about 5 to about 25 carbon atoms in the ester group. Representative examples are shown in U.S. Pat. Nos. 2,100,993, and 6,323,164. Polymethacrylate and polyacrylate dispersants may be used as multifunctional viscosity modifiers. The lower molecular weight versions can be used as lubricant dispersants or fuel detergents.
Illustrative dispersants useful in this disclosure include those derived from polyalkenyl-substituted mono- or dicarboxylic acid, anhydride or ester, wherein the polyalkenyl moiety has an average molecular weight of at least about 900 and from greater than 1.3 to 1.7 (e.g. from greater than 1.3 to 1.6 or from greater than 1.3 to 1.5) functional groups (mono- or dicarboxylic acid producing moieties) per polyalkenyl moiety (a medium functionality dispersant). Functionality (F) can be determined according to the following formula:
F=(SAP×Mn)/((112,200×A.I.)−(SAP×98)),
wherein:
SAP is the saponification number (i.e., the number of milligrams of KOH consumed in the complete neutralization of the acid groups in one gram of the succinic-containing reaction product, as determined according to ASTM D94);
Mn is the number average molecular weight of the starting olefin polymer; and
A.I. is the percent active ingredient of the succinic-containing reaction product (the remainder being unreacted olefin polymer, succinic anhydride and diluent).
The polyalkenyl moiety of the dispersant may have a number average molecular weight of at least about 900 or suitably at least about 1500, such as between about 1800 and about 3000 (e.g. between about 2000 and about 2800, from about 2100 to about 2500, or from about 2200 to about 2400). The molecular weight of a dispersant is generally expressed in terms of the molecular weight of the polyalkenyl moiety. This is because the precise molecular weight range of the dispersant depends on numerous parameters including the type of polymer used to derive the dispersant, the number of functional groups, and the type of nucleophilic group employed.
Polymer molecular weight, specifically Mn, can be determined by various known techniques. One convenient method is gel permeation chromatography (GPC), which additionally provides molecular weight distribution information (see W. W. Yau, J. J. Kirkland and D. D. Bly, “Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, New York, 1979). Another useful method for determining molecular weight, particularly for lower molecular weight polymers, is vapor pressure osmometry (e.g., ASTM D3592).
In an embodiment, the polyalkenyl moiety in a dispersant has a narrow molecular weight distribution (MWD), also referred to as polydispersity, as determined by the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn). Polymers having a Mw/Mn of less than 2.2 (e.g. less than 2.0) are most desirable. Suitable polymers have a polydispersity of from about 1.5 to 2.1 (e.g. from about 1.6 to about 1.8).
Suitable polyalkenes employed in the formation of the dispersants include homopolymers, interpolymers or lower molecular weight hydrocarbons. One family of such polymers comprise polymers of ethylene and/or at least one C3 to C26 alpha-olefin having the formula:
H₂C═CHR⁶,
wherein R⁶is a straight or branched chain alkyl radical comprising 1 to 26 carbon atoms and wherein the polymer contains carbon-to-carbon unsaturation, and a high degree of terminal ethenylidene unsaturation. In an embodiment, such polymers comprise interpolymers of ethylene and at least one alpha-olefin of the above formula, wherein R⁶is alkyl of from 1 to 18 carbon atoms (e.g. from 1 to 8 carbon atoms or from 1 to 2 carbon atoms).
Another useful class of polymers is polymers prepared by cationic polymerization of monomers such as isobutene and styrene. For example, the polymer(s) can be polyisobutenes obtained by polymerization of a C4 refinery stream having a butene content of 35 to 75% by wt., and an isobutene content of 30 to 60% by wt. Petroleum feestreams, such as Raffinate II, can be a source of monomer for making poly-n-butenes. These feedstocks are disclosed in the art such as in U.S. Pat. No. 4,952,739. Certain embodiments utilize polyisobutylene prepared from a pure isobutylene stream or a Raffinate I stream to prepare reactive isobutylene polymers with terminal vinylidene olefins. Polyisobutene polymers that may be employed may be based on a polymer chain of from about 1500 to about 3000.
In yet further embodiments, the dispersant(s) are non-polymeric (e.g., mono- or bis-succinimides). Such dispersants can be prepared by conventional processes, such as those disclosed in U.S. Patent Application Publication No. 2008/0020950, the disclosure of which is incorporated herein by reference.
The dispersant(s) can be borated by conventional means, as generally disclosed in U.S. Pat. Nos. 3,087,936, 3,254,025 and 5,430,105.
Dispersants may be used in an amount of zero to about 10 weight percent or about 0.01 to about 8 weight percent (e.g. about 0.1 to about 5 weight percent or about 0.5 to about 3 weight percent). Or such dispersants may be used in an amount of zero to about 8 weight percent (e.g. about 0.01 to about 5 weight percent or about 0.1 to about 3 weight percent). On an active ingredient basis, such additives may be used in an amount of zero to about 10 weight percent (e.g. about 0.3 to about 3 weight percent). The hydrocarbon portion of the dispersant atoms can range from about C60 to about C1000, or from about C70 to about C300, or from about C70 to about C200. These dispersants may contain both neutral and basic nitrogen, and mixtures thereof. Dispersants can be end-capped by borates and/or cyclic carbonates. Nitrogen content in the finished oil can vary from about zero to about 2000 ppm by weight (e.g. from about 100 ppm by weight to about 1200 ppm by weight). Basic nitrogen can vary from about zero to about 1000 ppm by weight (e.g. from about 100 ppm by weight to about 600 ppm by weight).
Dispersants as described herein are beneficially useful with the compositions of the present disclosure. Further, in one embodiment, preparation of the compositions of the present disclosure using one or more (e.g. 1, 2, 3, 4, or more) dispersants is achieved by combining ingredients of the present disclosure, plus optional base stocks and lubricant additives, in a mixture at a temperature above the melting point of such ingredients, particularly that of the one or more M-carboxylates (M=H, metal, two or more metals, mixtures thereof).
As used herein, the dispersant concentrations are given on an “as delivered” basis. The active dispersant may be delivered with a process oil. The “as delivered” dispersant may contain from about 20 weight percent to about 80 weight percent, or from about 40 weight percent to about 60 weight percent, of active dispersant in the “as delivered” dispersant product.
Friction Modifier(s).
In any aspect or embodiment described herein, the composition of the present disclosure comprises at least one (e.g., 1, 2, 3, or 4, or more) friction modifier. A friction modifier is any material or materials that can alter the coefficient of friction of a surface lubricated by any lubricant or fluid containing such material(s). Friction modifiers, also known as friction reducers, or lubricity agents or oiliness agents, and other such agents that change the ability of base oils, formulated lubricant compositions, or functional fluids, to modify the coefficient of friction of a lubricated surface may be effectively used in combination with the base oils or lubricant compositions of the present disclosure if desired. Friction modifiers that lower the coefficient of friction are particularly advantageous in combination with the base oils and lube compositions of this disclosure. Any friction modifier that is known or that becomes know may be utilized in the composition of the present disclosure.
Friction modifiers may include, for example, organometallic compounds or materials, or mixtures thereof. Illustrative organometallic friction modifiers useful in the lubricating turbine oil formulations of this disclosure include, for example, molybdenum amine, molybdenum diamine, an organotungstenate, a molybdenum dithiocarbamate, molybdenum dithiophosphates, molybdenum amine complexes, molybdenum carboxylates, and the like, and mixtures thereof. In an embodiment, tungsten-based compounds are utilized.
Other illustrative friction modifiers useful in the lubricating formulations of the present disclosure include, for example, alkoxylated fatty acid esters, alkanolamides, polyol fatty acid esters, borated glycerol fatty acid esters, fatty alcohol ethers, and mixtures thereof.
Illustrative alkoxylated fatty acid esters include, for example, polyoxyethylene stearate, fatty acid polyglycol ester, and the like. These can include polyoxypropylene stearate, polyoxybutylene stearate, polyoxyethylene isosterate, polyoxypropylene isostearate, polyoxyethylene palmitate, and the like.
Illustrative alkanolamides include, for example, lauric acid diethylalkanolamide, palmic acid diethylalkanolamide, and the like. These can include oleic acid diethyalkanolamide, stearic acid diethylalkanolamide, oleic acid diethylalkanolamide, polyethoxylated hydrocarbylamides, polypropoxylated hydrocarbylamides, and the like.
Illustrative polyol fatty acid esters include, for example, glycerol mono-oleate, saturated mono-, di-, and tri-glyceride esters, glycerol mono-stearate, and the like. These can include polyol esters, hydroxyl-containing polyol esters, and the like.
Illustrative borated glycerol fatty acid esters include, for example, borated glycerol mono-oleate, borated saturated mono-, di-, and tri-glyceride esters, borated glycerol monosterate, and the like. In addition to glycerol polyols, these can include trimethylolpropane, pentaerythritol, sorbitan, and the like. These esters can be polyol monocarboxylate esters, polyol dicarboxylate esters, and on occasion polyoltricarboxylate esters. In certain embodiments, the friction modifier is glycerol mono-oleates, glycerol dioleates, glycerol trioleates, glycerol monostearates, glycerol distearates, and glycerol tristearates and the corresponding glycerol monopalmitates, glycerol dipalmitates, glycerol tripalmitates, or the respective isostearates, linoleates, and the like, or combinations thereof. In an embodiment, the friction modifier is a glycerol esters or mixtures containing any of these. Ethoxylated, propoxylated, butoxylated fatty acid esters of polyols, especially using glycerol as underlying polyol can be utilized.
Illustrative fatty alcohol ethers include, for example, stearyl ether, myristyl ether, and the like. Alcohols, including those that have carbon numbers from C3 to C50, can be ethoxylated, propoxylated, or butoxylated to form the corresponding fatty alkyl ethers. The underlying alcohol portion can be, e.g., stearyl, myristyl, C11-C13 hydrocarbon, oleyl, isosteryl, and the like.
Other friction modifiers could be optionally included in addition to the fatty phosphites and fatty imidazolines. A useful list of such other friction modifier additives is included in U.S. Pat. No. 4,792,410. U.S. Pat. No. 5,110,488 discloses metal salts of fatty acids and especially zinc salts, useful as friction modifiers. Fatty acids are also useful friction modifiers. A list of other suitable friction modifiers includes at least one of: (i) fatty phosphonates; (ii) fatty acid amides; (iii) fatty epoxides; (iv) borated fatty epoxides; (v) fatty amines; (vi) glycerol esters; (vii) borated glycerol esters; (viii) alkoxylated fatty amines; (ix) borated alkoxylated fatty amines; (x) metal salts of fatty acids; (xi) sulfurized olefins; (xii) condensation products of carboxylic acids or equivalents and polyalkylene-polyamines; (xiii) metal salts of alkyl salicylates; (xiv) amine salts of alkylphosphoric acids; (xv) fatty esters; (xvi) condensation products of carboxylic acids; or equivalents with polyols and mixtures thereof.
Representatives of each of these types of friction modifiers are known and are commercially available. For instance, (i) includes components of the formulas:
(RO)2PHO,
(RO)(HO)PHO, and
P(OR)(OR)(OR),
wherein, in these structures, the each “R” is conventionally referred to as an alkyl group, but may also be hydrogen. It is, of course, possible that the alkyl group is actually alkenyl and thus the terms “alkyl” and “alkylated,” as used herein, will embrace other than saturated alkyl groups within the component. The component should have sufficient hydrocarbyl groups to render it substantially oleophilic. In some embodiments, the hydrocarbyl groups are substantially un-branched. Many suitable such components are available commercially and may be synthesized as described in U.S. Pat. No. 4,752,416. In some embodiments, the component contains 8 to 24 carbon atoms in each of the R groups. In other embodiments, the component may be a fatty phosphite containing 12 to 22 carbon atoms in each of the fatty radicals, or 16 to 20 carbon atoms. In one embodiment the fatty phosphite can be formed from oleyl groups, thus having 18 carbon atoms in each fatty radical.
The (iv) borated fatty epoxides are known from Canadian Patent No. 1,188,704.
These oil-soluble boron-containing compositions are prepared by reacting, at a temperature from 80° C. to 250° C., boric acid or boron trioxide with at least one fatty epoxide having the formula:
wherein each of R⁷, R⁸, R⁹and R¹⁰is independently hydrogen or an aliphatic radical, or any two thereof together with the epoxy carbon atom or atoms to which they are attached, form a cyclic radical. In an embodiment, the fatty epoxide contains at least 8 carbon atoms.
The borated fatty epoxides can be characterized by the method for their preparation which involves the reaction of two materials. Reagent A can be boron trioxide or any of the various forms of boric acid including metaboric acid (HBO₂), orthoboric acid (H₃BO₃) and tetraboric acid (H₂B₄0₇). In an embodiment, Reagent A is boric acid, such as orthoboric acid. Reagent B can be at least one fatty epoxide having the above formula. In the formula, each of the R groups is most often hydrogen or an aliphatic radical with at least one being a hydrocarbyl or aliphatic radical containing at least 6 carbon atoms. The molar ratio of reagent A to reagent B may be about 1:0.25 to about 1:4 (e.g. about 1:1 to about 1:3 or about 1:2). The borated fatty epoxides can be prepared by merely blending the two reagents and heating them at temperature of about 80° C. to about 250° C., such as about 100° C. to about 200° C., for a period of time sufficient for reaction to take place. If desired, the reaction may be effected in the presence of a substantially inert, normally liquid organic diluent. During the reaction, water is evolved and may be removed by distillation.
The (iii) non-borated fatty epoxides, corresponding to Reagent B above, are also useful as friction modifiers.
Borated amines are generally known from U.S. Pat. No. 4,622,158. Borated amine friction modifiers (including (ix) borated alkoxylated fatty amines) can be prepared by the reaction of a boron compounds, as described above, with the corresponding amines. The amine can be a simple fatty amine or hydroxy containing tertiary amines. The borated amines can be prepared by adding the boron reactant, as described above, to an amine reactant and heating the resulting mixture at about 50° C. to about 300° C. (e.g. about 100° C. to about 250° C. or about 130° C. to about 180° C.) with stirring. The reaction is continued until by-product water ceases to evolve from the reaction mixture indicating completion of the reaction.
Among the amines useful in preparing the borated amines are commercial alkoxylated fatty amines known by the trademark “ETHOMEEN” and available from Akzo Nobel. Representative examples of these ETHOMEEN™ materials is ETHOMEEN™ C/12 (bis[2-hydroxyethyl]-coco-amine); ETHOMEEN™ C/20 (polyoxyethylene-[10]cocoamine); ETHOMEEN™ S/12 (bis[2-hydroxyethyl]¬soyamine); ETHOMEEN™ T/12 (bis[2-hydroxyethyl]-tallow-amine); ETHOMEEN™ T/15 (polyoxyethylene-[5]tallowamine); ETHOMEEN™ 0/12 (bis[2-hydroxyethyl]oleyl-amine); ETHOMEEN™ 18/12 (bis[2-hydroxyethyl]-octadecylamine); and ETHOMEEN™ 18/25 (polyoxyethylene[15]-octadecylamine). Fatty amines and ethoxylated fatty amines are also described in U.S. Pat. No. 4,741,848. Dihydroxyethyl tallowamine (commercially sold as ENT-12™) is included in these types of amines.
The (viii) alkoxylated fatty amines, and (v) fatty amines themselves (such as oleylamine and dihydroxyethyl tallowamine) may be useful as friction modifiers in this disclosure. Such amines are commercially available.
Both borated and unborated fatty acid esters of glycerol can be used as friction modifiers. The (vii) borated fatty acid esters of glycerol are prepared by borating a fatty acid ester of glycerol with boric acid with removal of the water of reaction. In an embodiment, there is sufficient boron present such that each boron will react with from 1.5 to 2.5 hydroxyl groups present in the reaction mixture. The reaction may be carried out at a temperature in the range of about 60° C. to about 135° C., in the absence or presence of any suitable organic solvent, such as methanol, benzene, xylenes, toluene, or oil.
The (vi) fatty acid esters of glycerol themselves can be prepared by a variety of methods well known in the art. Many of these esters, such as glycerol monooleate and glycerol tallowate, are manufactured on a commercial scale. In a particular embodiment, the esters are oil-soluble and prepared from C8 to C22 fatty acids or mixtures thereof, such as are found in natural products and as are described in greater detail below. In an embodiment, fatty acid monoesters of glycerol used, although, mixtures of mono- and diesters may be used. For example, commercial glycerol monooleate may contain a mixture of 45% to 55% by weight monoester and 55% to 45% diester.
Fatty acids can be used in preparing the above glycerol esters; they can also be used in preparing their (x) metal salts, (ii) amides, and (xii) imidazolines, any of which can also be used as friction modifiers. In an embodiment, the fatty acids are those containing 10 to 24 carbon atoms, such as those containing 12 to 18 carbon atoms. The acids can be branched or straight-chain, saturated or unsaturated. In some embodiments, the acids are straight-chain acids. In other embodiments, the acids are branched. Suitable acids include decanoic, oleic, stearic, isostearic, palmitic, myristic, palmitoleic, linoleic, lauric, and linolenic acids, and the acids from the natural products tallow, palm oil, olive oil, peanut oil, corn oil, coconut oil and Neat's foot oil. In certain embodiments, the acid is oleic acid. In other embodiments, the metal salts include zinc and calcium salts. Examples are overbased calcium salts and basic oleic acid-zinc salt complexes, such as zinc oleate, which can be represented by the formula Zn₄Oleate₆O₁. In an embodiment, the amides are those prepared by condensation with ammonia or with primary or secondary amines such as ethylamine and diethanolamine. Fatty imidazolines are the cyclic condensation product of an acid with a diamine or polyamine, such as a polyethylenepolyamine. The imidazolines may be represented by the structure:
wherein: R is an alkyl group; and R′ is hydrogen or a hydrocarbyl group or a substituted hydrocarbyl group, including —(CH₂CH₂NH)_n— groups, wherein n is an integer from 1 to 4. In an embodiment, the friction modifier is the condensation product of a C10 to C24 fatty acid with a polyalkylene polyamine, and in particular, the product of isostearic acid with tetraethylenepentamine.
The condensation products of carboxylic acids and polyalkyleneamines (xiii) may be imidazolines or amides. They may be derived from any of the carboxylic acids described above and any of the polyamines described herein.
Sulfurized olefins (xi) are well known commercial materials used as friction modifiers. A particularly sulfurized olefin utilized herein is one which is prepared in accordance with the detailed teachings of U.S. Pat. Nos. 4,957,651 and 4,959,168. Described therein is a co-sulfurized mixture of 2 or more reactants selected from the group consisting of (1) at least one fatty acid ester of a polyhydric alcohol, (2) at least one fatty acid, (3) at least one olefin, and (4) at least one fatty acid ester of a monohydric alcohol. Reactant (3), the olefin component, comprises at least one olefin. This olefin is may be an aliphatic olefin, which usually will contain 4 to 40 carbon atoms, e.g. from 8 to 36 carbon atoms. For example, terminal olefins, or alpha-olefins, including those having from 12 to 20 carbon atoms, may be utilized. Mixtures of these olefins are commercially available, and such mixtures are contemplated for use in this disclosure. The co-sulfurized mixture of two or more of the reactants, is prepared by reacting the mixture of appropriate reactants with a source of sulfur. The mixture to be sulfurized can contain about 10 to about 90 parts of Reactant (1), or about 0.1 to about 15 parts by weight of Reactant (2); or about 10 to about 90 parts (e.g. about 15 to about 60 parts or about 25 to about 35 parts) by weight of Reactant (3), or about 10 to about 90 parts by weight of reactant (4). The mixture, in the present disclosure, includes Reactant (3) and at least one other member of the group of reactants identified as Reactants (1), (2) and (4). The sulfurization reaction may be effected at an elevated temperature with agitation and optionally in an inert atmosphere and in the presence of an inert solvent. The sulfurizing agents useful in the process of the present disclosure include elemental sulfur, which maybe hydrogen sulfide, sulfur halide plus sodium sulfide, and a mixture of hydrogen sulfide and sulfur or sulfur dioxide. For example, about 0.5 to about 3 moles of sulfur are employed per mole of olefinic bonds. Sulfurized olefins may also include sulfurized oils, such as vegetable oil, lard oil, oleic acid and olefin mixtures.
Metal salts of alkyl salicylates (xiii) include calcium and other salts of long chain (e.g. C12 to C16) alkyl-substituted salicylic acids.
Amine salts of alkylphosphoric acids (xiv) include salts of oleyl and other long chain esters of phosphoric acid, with amines as described below. Useful amines in this regard are tertiary-aliphatic primary amines, sold under the tradename Primene™.
In some embodiments, the friction modifier is a fatty acid or fatty oil, a metal salt of a fatty acid, a fatty amide, a sulfurized fatty oil or fatty acid, an alkyl phosphate, an alkyl phosphate amine salt; a condensation product of a carboxylic acid and a polyamine, a borated fatty epoxide, a fatty imidazoline, or combinations thereof.
In other embodiments, the friction modifier may be the condensation product of isostearic acid and tetraethylene pentamine, the condensation product of isostearic acid and 1-[tris(hydroxymethyl)]methylamine, borated polytetradecyloxirane, zinc oleate, hydroxylethyl-2-heptadecenyl imidazoline, dioleyl hydrogen phosphate, C14-C18 alkyl phosphate or the amine salt thereof, sulfurized vegetable oil, sulfurized lard oil, sulfurized oleic acid, sulfurized olefins, oleyl amide, glycerol monooleate, soybean oil, or mixtures thereof.
In still other embodiments, the friction modifier may be glycerol monooleate, oleylamide, the reaction product of isostearic acid and 2-amino-2-hydroxymethyl-1,3-propanediol, sorbitan monooleate, 9-octadecenoic acid, isostearyl amide, isostearyl monooleate or combinations thereof.
Although their presence is not required to obtain the benefit of the present disclosure, friction modifiers may be present in an amount from zero to about 2 wt. % (e.g., about 0.01 wt. % to about 1.5 wt. %) of the composition of the present disclosure. These ranges may apply to the amounts of individual friction modifier present in the composition or to the total friction modifier component in the compositions, which may include a mixture of two or more friction modifiers.
Many friction modifiers tend to also act as emulsifiers. This is often due to the fact that friction modifiers often have non-polar fatty tails and polar head groups.
The composition of the present disclosure exhibit desired properties, e.g., wear control, in the presence or absence of a friction modifier.
Although their presence is not required to obtain the benefit of this disclosure, the friction modifier or friction modifiers may be present in an amount of about 0.01 weight percent to about 5 weight percent (e.g. about 0.1 weight percent to about 2.5 weight percent, or about 0.1 weight percent to about 1.5 weight percent, or about 0.1 weight percent to about 1 weight percent). Concentrations of molybdenum-containing materials are often described in terms of Mo metal concentration. Advantageous concentrations of Mo may range from about 25 ppm to about 700 ppm or more (e.g. about 50 to about 200 ppm). Friction modifiers of all types may be used alone or in mixtures with the materials of this disclosure. Often mixtures of two or more friction modifiers, or mixtures of friction modifier(s) with alternate surface active material(s), are also desirable.
Molybdenum-Containing Compounds (Friction Reducers).
Illustrative molybdenum-containing friction reducers useful in the disclosure include, for example, an oil-soluble decomposable organo molybdenum compound, such as Molyvan™ 855 which is an oil soluble secondary diarylamine defined as substantially free of active phosphorus and active sulfur. The Molyvan™ 855 is described in Vanderbilt's Material Data and Safety Sheet as a organomolybdenum compound having a density of 1.04 and viscosity at 100° C. of 47.12 cSt. The organo molybdenum compounds may be useful because of their superior solubility and effectiveness.
Another illustrative molybdenum-containing compound is Molyvan™ L, which is sulfonated oxymolybdenum dialkyldithiophosphate described in U.S. Pat. No. 5,055,174 hereby incorporated by reference.
Molyvan™ A made by R. T. Vanderbilt Company, Inc., New York, N.Y., USA, is also an illustrative molybdenum-containing compound, which contains about 28.8 wt. % Mo, 31.6 wt. % C, 5.4 wt. % H., and 25.9 wt. % S. Also useful are Molyvan™ 855, Molyvan™ 822, Molyvan™ 856, and Molyvan™ 807.
Also useful is Sakura Lube™ 500, which is more soluble Mo dithiocarbamate containing lubricant additive obtained from Asahi Denki Corporation and comprised of about 20.2 wt. % Mo, 43.8 wt. % C, 7.4 wt. % H, and 22.4 wt. % S. Sakura Lube™ 300, a low sulfur molybdenum dithiophosphate having a molybdenum to sulfur ratio of 1:1.07, is a molybdenum-containing compound useful in this disclosure.
Also useful is Molyvan™ 807, a mixture of about 50 wt. % molybdenum ditridecyldithyocarbonate, and about 50 wt. % of an aromatic oil having a specific gravity of about 38.4 SUS and containing about 4.6 wt. % molybdenum, also manufactured by R. T. Vanderbilt and marketed as an antioxidant and antiwear additive.
Other sources are molybdenum Mo(Co)₆, and molybdenum octoate, MoO(C₇H₁₅CO₂)₂containing about 8 wt-% Mo marketed by Aldrich Chemical Company, Milwaukee, Wis. and molybdenum naphthenethioctoate marketed by Shephard Chemical Company, Cincinnati, Ohio.
Inorganic molybdenum compounds, such as molybdenum sulfide and molybdenum oxide, are substantially less preferred than the organic compounds as described in Molyvan™ 855, Molyvan™ 822, Molyvan™ 856, and Molyvan™ 807.
Illustrative molybdenum-containing compounds useful in this disclosure are disclosed, for example, in U.S. Patent Application Publication No. 2003/0119682, which is incorporated herein by reference.
Organo molybdenum-nitrogen complexes may also be included in the formulations of the present disclosure. The term “organo molybdenum nitrogen complexes” embraces the organo molybdenum nitrogen complexes described in U.S. Pat. No. 4,889,647. The complexes are reaction products of a fatty oil, dithanolamine and a molybdenum source. Specific chemical structures have not been assigned to the complexes. U.S. Pat. No. 4,889,647 reports an infrared spectrum for an exemplary reaction product of that disclosure; the spectrum identifies an ester carbonyl band at 1740 cm 1 and an amide carbonyl band at 1620 cm 1. The fatty oils are glyceryl esters of higher fatty acids containing at least 12 carbon atoms up to 22 carbon atoms or more. The molybdenum source is an oxygen-containing compound such as ammonium molybdates, molybdenum oxides and mixtures.
Other organo molybdenum complexes which can be used in the present disclosure are tri nuclear molybdenum sulfur compounds described in EP 1 040 115 and WO 99/31113, and the molybdenum complexes described in U.S. Pat. No. 4,978,464.
Although their presence is not required to obtain the benefit of the present disclosure, molybdenum-containing additives may be used in an amount of from zero to about 5.0 (e.g., ≤about 5, ≤about 4, ≤about 3, ≤about 2, or ≤about 1) percent by mass of the composition of the present disclosure. For example, the dosage may be up to about 3,000 ppm by mass, such as from about about 100 ppm to about about 2,500 ppm by mass, from about 300 to about 2,000 ppm by mass, or from about 300 to about 1,500 ppm by mass of molybdenum.
Borated Ester Compounds.
In any aspect or embodiment described herein, the composition of the present disclosure comprises at least one (e.g., 1, 2, 3, or 4, or more) borated-ester compound. Illustrative boron-containing compounds useful in the disclosure include, for example, a borate ester, a boric acid, other boron compounds, such as a boron oxide. The boron compound is hydrolytically stable and is utilized for improved antiwear, and performs as a rust and corrosion inhibitor for copper bearings and other metal engine components. The borated ester compound acts as an inhibitor for corrosion of metal to prevent corrosion of either ferrous or non-ferrous metals (e.g. copper, bronze, brass, titanium, aluminum and the like) or both, present in concentrations in which they are effective in inhibiting corrosion.
Patents describing techniques for making basic salts of sulfonic, carboxylic acids and mixtures thereof include U.S. Pat. Nos. 5,354,485; 2,501,731; 2,616,911; 2,777,874; 3,384,585; 3,320,162; 3,488,284; and 3,629,109. The disclosures of these patents are incorporated herein by reference. Methods of preparing borated overbased compositions are found in U.S. Pat. Nos. 4,744,920; 4,792,410; and PCT publication WO 88/03144. The disclosures of these references are incorporated herein by reference. The oil-soluble neutral or basic salts of alkali or alkaline earth metals salts may also be reacted with a boron compound.
An illustrative borate ester utilized in this disclosure is manufactured by Exxon-Mobil USA under the product designation of (“MCP 1286”) and MOBIL ADC700. Test data show the viscosity at 100° C. using the D-445 method is 2.9 cSt; the viscosity at 40° C. using the D-445 method is 11.9; the flash point using the D-93 method is 146; the pour point using the D-97 method is −69; and the percent boron as determined by the ICP method is 5.3%. The borated ester (Vanlube™ 289), which is marketed as an antiwear/antiscuff additive and friction reducer, is an exemplary borate ester useful in the disclosure.
An illustrative borate ester useful in this disclosure is the reaction product obtained by reacting about 1 mole fatty oil, about 1.0 to 2.5 moles diethanolamine followed by subsequent reaction with boric acid to yield about 0.1 to 3 percent boron by mass. It is believed that the reaction products may include one or both of the following two primary components, with the further listed components being possible components when the reaction is pushed toward full hydration:
where R₁═H or C_xH_ywhere x=1 to 60, and y=3 to 121
wherein Y represents a fatty oil residue. In an embodiment, the fatty oils are glyceryl esters of higher fatty acids containing at least 12 carbon atoms (e.g. 22 carbon atoms or more). Such esters are commonly known as vegetable and animal oils. Vegetable oils that may be used include oils derived from coconut, corn, cottonseed, linseed, peanut, soybean and sunflower seed. Similarly, animal fatty oils such as tallow may be used.
The source of boron is boric acid or materials that afford boron and are capable of reacting with the intermediate reaction product of fatty oil and diethanolamine to form a borate ester composition.
While the above organoborate ester composition is specifically discussed above, it should be understood that other organoborate ester compositions should also function with similar effect in the present disclosure, such as those set forth in U.S. Patent Application Publication No. 2003/0119682, which is incorporated herein by reference. In addition, dispersions of borate salts, such as potassium borate, may also be useful.
Other illustrative organoborate compositions useful in this disclosure are disclosed, for example, in U.S. Patent Application Publication No. 2008/0261838, which is incorporated herein by reference.
In addition, other illustrative oranoborate compositions useful in this disclosure are disclosed, for example, U.S. Pat. Nos. 4,478,732, 4,406,802, 4,568,472 on borated mixed hydroxyl esters, alkoxylated amides, and amines; U.S. Pat. No. 4,298,486 on borated hydroxyethyl imidazolines; U.S. Pat. No. 4,328,113 on borated alkyl amines and alkyl diamines; U.S. Pat. No. 4,370,248 on borated hydroxyl-containing esters, including GMO; U.S. Pat. No. 4,374,032 on borated hydroxyl-containing hydrocarbyl oxazolines; U.S. Pat. No. 4,376,712 on borated sorbitan esters; U.S. Pat. No. 4,382,006 on borated ethoxylated amines; U.S. Pat. No. 4,389,322 on ethoxylated amides and their borates; U.S. Pat. No. 4,472,289 on hydrocarbyl vicinal diols and alcohols and ester mixtures and their borates; U.S. Pat. No. 4,522,734 on borates of hydrolyzed hydrocarbyl epoxides; U.S. Pat. No. 4,537,692 on etherdiamine borates; U.S. Pat. No. 4,541,941 on mixtures containing vicinal diols and hydroxyl substituted esters and their borates; U.S. Pat. No. 4,594,171 on borated mixtures of various hydroxyl and/or nitrogen containing borates; and U.S. Pat. No. 4,692,257 on various borated alcohols/diols, all of which are incorporated herein by reference.
Although their presence is not required to obtain the benefit of this disclosure, boron-containing compounds may be present in an amount of from zero to about 10.0% percent (e.g. from about 0.01% to about 5% or from about 0.1% to about 3.0%) by weight of the composition of the present disclosure. An effective elemental boron range of up to about 1000 ppm or less than about 1% elemental boron. Thus, in an embodiment, a concentration of elemental boron is from about 100 to about 1000 ppm (e.g. from about 100 to about 300 ppm).
When the grease composition of the present disclosure includes one or more of the additives discussed herein, the additive(s) are blended into the composition in an amount sufficient for it to perform its intended function.
The weight percent (wt. %) indicated throughout the present Application is based on the total weight of the composition of the present disclosure. It is noted that many of the additives are shipped from the additive manufacturer as a concentrate, containing one or more additives together, with a certain amount of base oil diluents. Accordingly, the weight amounts mentioned herein are directed to the amount of active ingredient (that is the non-diluent portion of the ingredient).

Example 1 Antioxidant Polymer Preparation

An antioxidant diphenyl amine monomer mixture containing N,N-diphenylamine, N,N-di-(p-tert-butylphenyl)amine, N,N-di-(p-tert-octylphenyl)amine, N-(p-tert-butylphenyl)-N-phenylamine, N-(p-tert-octylphenyl)-N-phenylamine and N-(p-tert-butylphenyl)-N-(p-tert-octylphenyl)amine is charged together with n-decane to a 3 L glass reactor connected to a Dean-Stark head with a reflux condenser. The mixture is heated to 135° C. and t-butylperoxide is added dropwise with stirring. The temperature is maintained at 135° C. to 140° C. with stirring and t-butanol is distilled off. Samples are removed and tested for viscosity. Upon reaching a desired viscosity, unreacted peroxide is removed under reduced pressure, then the mixture is heated under reduced pressure to remove remaining volatiles. The diphenyl amine monomer mixture is CAS number 68411-46-1; N-phenyl-benzenamine reaction products with 2,4,4-trimethylpentene.
The monomer mixture exhibits a viscosity of 9.1 cSt (monomer). Polymers or oligomers are prepared having viscosities of 21 cSt (inventive sample 1), 81 cSt (inventive sample 2) and 100 cSt (inventive sample 3). Viscosity is kinematic viscosity at 100° C. determined according to ASTM D445.
The viscosity and Mn of the samples can be controlled by, e.g., the length of the reaction or the feed of the peroxide.

Example 2

It is demonstrated that m/z ions in the isolated polymers and oligomers show a correlation to increased performance in a VIT test.
The table below shows that the m/z ion counts at 838, 984 and 911 Daltons are significantly higher than the #4 residue which has a lower VIT result. The higher the VIT value, the better the antioxidant


Sample	VIT (h to pvisc 150)	838	894	911

Reference	470	0	0	0
Sample 1	830	296	225	65
Sample 2	797	386	179	65
Sample 3	533	49	65	8

FIG. 1 shows a trend that VIT performance is better when there is a greater amount of dimers and trimers as compared to the amount of higher polymers (4+) in conjunction with the LC/MS data that yields the 838 and 894 (which corresponds to 837 and 893 Daltons)

Example 3

A polymeric composition of the present disclosure is included as a component in a grease formulation as shown below.


	Formulation Details (wt %)

Base Stocks	71.5-73%	71.5-73%	71.5-73%
Thickener	7-8.5	7-8.5	7-8.5
Additives	13.37	13.37	13.37
(Standard) IRGANOX L57	1.00	2.00	0.00
Inventive 3	0.00	0.00	1.00
Total	100	100	100

Testing Results

ASTM D445-Kinematic	220.0	220.0	220.0
Viscosity at 40° C. (cSt)
ASTM D217-Penetration,	287.0	287.0	294.0
Worked (0.1 mm)
ASTM D5483 PDSC of Greases	23	N/A	17.3
(Isothermal at 210 C.)
ASTM D942-Pressure Vessel	1.1	N/A	2.4
Oxidation Test @ 100 hrs
(psi drop)
ASTM D942-Pressure Vessel	8	N/A	10.4
Oxidation Test @ 100 hrs
(psi drop)
DIN 51821 FAG FE9 A/1500/	84.0		135.0
6000 @ 140 C. (B50, hours)

All of the formulations in the above Table are Lithium complex (thickener type) greases, with ISO Viscosity grades of 220 and an NLGI consistency grade of 2. Common grease thickener types are simple lithium soap, lithium complex soap, polyurea, calcium sulfonate, aluminum soap, calcium soap, mixed aluminum/calcium, clay and polymer thickened. Greases contain, e.g., 70-80% basestock, 0.1-20% thickener, and 0-20% additives. The data demonstrates that the inventive example treated at 1% has the same oxidative performance as the commercial example treated at 1% in grease bench oxidation tests (ASTM D5483 and D942). However, when the same greases were tested in the DIN 51821 FAG FE9 test (rig test—high temperature bearing performance of a grease) the grease with the inventive example demonstrated superior performance compare to the grease that contained 1% commercial example and the grease that contained 2% of the commercial example. This is unexpected given the equivalent performance in the bench oxidation testing. According to the above data, the inventive antioxidant polymercomposition can be utilized in the preparation of a grease to improve high temperature bearing performance.

Claims

1. A lubricating grease composition comprising a base oil;

a thickener; and

from about 0.01 wt % to about 20 wt %, based on the total weight of the lubricating grease composition, of an antioxidant polymer composition comprising repeat units of diphenylamine monomers of formula I

wherein

R is H, C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, —C(O)C₁-C₁₈alkyl, —C(O)aryl and R₁, R₂, R₃and R₄are each independently H or a linear or branched C₁-C₁₈alkyl, C₁-C₁₈alkoxy, C₁-C₁₈alkylamino, C₁-C₁₈dialkylamino, C₁-C₁₈alkylthio, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl or C₇-C₂₁aralkyl and

wherein

the number average molecular weight (Mn) of the polymer composition is from about 350 g/mol to about 5000 g/mol.

2. The lubricating grease composition according to claim 1, wherein the thickener is selected from the group consisting of simple lithium soap, lithium complex soap, polyurea, calcium sulfonate, aluminum soap, calcium soap, mixed aluminum/calcium, clay, polymer and a combination thereof.

3. The lubricating grease composition according to claim 2, wherein the thickener comprises a lithium complex soap.

4. The lubricating grease composition according to claim 1, comprising one or more components selected from the group consisting of other antioxidants, antiwear additives, polymers, detergents, dispersants, pour point depressants, corrosion inhibitors, metal deactivators, complexing agents, antifoam agents, inhibitors, antirust additives, and friction modifiers.

5. The grease composition of claim 1, wherein the base oil comprises at least one of a Group I oil, a Group II oil, a Group III oil, a Group IV oil, a Group V oil, a gas-to-liquid oil, or combinations thereof.

6. The lubricating grease composition according to claim 1, having an ISO Viscosity grades of about 100 to about 680.

7. The lubricating grease composition according to claim 1, having an NLGI consistency grade of 000 to 6.

8. The lubricating grease composition according to claim 1, wherein the Mn of the antioxidant antioxidant polymer composition is from about 400 g/mol to about 5000 g/mol.

9. The lubricating grease composition according to claim 1, wherein R₁, R₂, R₃and R₄are each independently H or a linear or branched C₄-C₁₀alkyl.

10. The lubricating grease composition according to claim 1, wherein R is H.

11. The lubricating grease composition of claim 1, wherein the antioxidant polymer composition is an oligomer composition.

12. A lubricating grease composition comprising a base oil;

a water insoluble thickener; and

from about 0.01 wt % to about 20 wt %, based on the total weight of the lubricating grease composition, of a polymer composition comprising repeat units of diphenylamine monomers of formula I

wherein

R is H, C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl, —C(O)C₁-C₁₈alkyl, —C(O)aryl and R₁, R₂, R₃and R₄are each independently H or a linear or branched C₁-C₁₈alkyl, C₁-C₁₈alkoxy, C₁-C₁₈alkylamino, C₁-C₁₈dialkylamino, C₁-C₁₈alkylthio, C₂-C₁₈alkenyl, C₂-C₁₈alkynyl or C₇-C₂₁aralkyl, and

wherein the polymer composition comprises ≤70 wt % residual monomers of formula I.

13. A lubricating grease composition comprising

a base oil; and

wherein

14. A method of improving the high temperature performance of a bearing comprising adding to the bearing the lubricating grease composition of claim 1.