Fluids for Extreme Pressure and Wear Applications

Abstract

Provided are compositions, additives for forming compositions, methods of operating apparatus in fluid communication with the compositions, and apparatus comprising the compositions. For example, the composition may include a polyalphaolefin component of from about 95% to about 99.5% w / w. The composition may include an additive component. The additive component may include an anti-wear agent. The anti-wear agent may be from about 0.1% to about 2% w / w. The anti-wear component may be characterized by an acid value of at least about 1 mg KOH / g. The additive component may include an aryl amine antioxidant agent, an anti-rust agent, and a metal deactivator agent. The composition may be characterized by a kinematic viscosity at 100° C. of at least about 5 centiStokes, a viscosity index of at least about 80, and an acid value in mg KOH / g of between about 0.1 and about 1.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 15 / 611,737, filed Apr. 25, 2016, which is a continuation-in-part application of U.S. patent application Ser. No. 15 / 137,799, filed Apr. 25, 2016, which is a continuation application of U.S. patent application Ser. No. 13 / 848,227, filed Mar. 21, 2013, now U.S. Pat. No. 9,321,980, which is a continuation application of U.S. patent application Ser. No. 12 / 924,984, filed Oct. 8, 2010. Each of the preceding applications is entirely incorporated herein by reference.GOVERNMENT SUPPORT[0002]This invention was made with government support under contract no. N00024-05-C-4169 awarded by the Department of Defense. The government may have certain rights in the invention.FIELD OF THE INVENTION[0003]Provided are lubricant and functional fluids suitable for high-stress applications.BACKGROUND[0004]Lubricants and functional fluids used in submarine propulsion systems may encounter chal...

AI Technical Summary

Benefits of technology

[0022]The more rigorous performance conditions demanded by newer ships may be handled by lubricating using the fluid composition of the present invention. In addition to submarines, newer surface ships with controllable pitch propeller systems have placed additional demands on the existing 2190-TEP lubricant. The improved properties of the present invention may also find advantageous use in place of existing hydraulic fluids, air compressor fluids and reducing gear fluids. Another advantage of the present invention is that a single formulation may be produced, stored and sourced for a variety of uses, which may be especially beneficial while at sea. Accordingly, applications for the present invention include lubricating and hydraulic oil, and other functional fluids for motion control, steam turbines and gears in ships and submarines, as submarine air compressor lubricating oil, and in controllable pitch propeller systems in ships and submarines. Of particular interest in many military applications are new lubricants or functional fluids that are able to provide both corrosion resistance and lubricating properties. Until now no synthetic lubricant composition has met certain stringent military requirements such as those in U.S. military specification MIL-PRF-17331 for both lubricating and anticorrosive properties.

[0023]In addition, lubricant or functional fluid additive packages and lubricants and functional fluids of the present invention may find additional commercial applications in lubricating environments involving desired low turnover and / or high gear-to-fluid volume interactions, such as may be found, for instance in wind turbine gear systems. Many of the issues faced in submarines are also presented in wind turbines, where it may be desirable to operate over long operating time intervals in remote locations, and with substantial effort and expense associated with lubricant change-over.

[0024]The invention includes, inter alia, an additive package, a lubricant or functional fluid including the additive package, apparatus containing the lubricant or functional fluid, and methods of operating apparatus using the lubricant or functional fluid.

[0025]In various embodiments, a composition is provided. The composition may include a polyalphaolefin component in a percentage, w / w of the composition, of from about 95% to about 99.5%. The composition may include an additive component. The additive component may include an anti-wear agent. The anti-wear agent may be, in a percentage, w / w of the composition, of from about 0.1% to about 2%. The anti-wear component may be characterized by an acid value of at least about 1 mg KOH / g. The additive component may include an aryl amine antioxidant agent. The additive component may include an anti-rust agent. The additive component may include a metal deactivator agent. The composition may be characterized by a kinematic viscosity at 100° C. of at least about 5 centiStokes. The composition may be characterized by a viscosity index of at least about 80. The composition may be characterized by an acid value in mg KOH / g of between about 0.1 and about 1.

[0026]In some embodiments, the polyalphaolefin component may be, in a percentage, w / w of the composition, of one of about 95, 95.5, 96, 96.5, 97, 97.5, 98, 98.5, 99, or 99.5, or a range between any two of the preceding values, for example, from about 95% to about 99.5%. The polyalphaolefin component may be any polyalphaolefin component, or a blend thereof, such as commercially available polyalphaolefin compositions and blends. Examples of commercially available polyalphaolefin compositions are typically sold according to nominal kinematic viscosity at 100° C. in centiStokes, e.g., SYNTON® PAO 40 (Chemtura Corporation, Middlebury, Conn.) has a kinematic viscosity at 100° C. of 40 centiStokes; SynBase Polyolefin 40 (Solitex, Inc., Houston, Tex.) has a kinematic viscosity at 100° C. of 41-43 centiStokes; SYNFLUID® PAO 40 (Chevron Phillips Chemical Company LP, The Woodlands, Tex.) has a kinematic viscosity at 100° C. of 39 centiStokes; and the like. In various embodiments of the composition, the polyalphaolefin component may include any such component or blend thereof with desired kinematic viscosity. For example, the kinematic viscosity of the composition at 100° C. in centiStokes may be about, or at least about, one or more of: 10, 10.25, 10.5, 10.75, 11, 11.25, 11.5, 11.75, 12, 12.25, 12.5, 12.75, 13, 13.5, 14, 14.5, 15, 17.5,20, 25, 30, 35, 40, 45, 50, 75, or 100, or a range between any two of the preceding values, for example, between about 10 and about 100. In various embodiments, the kinematic viscosity may be determined at least in part by the polyalphaolefin component. The desired kinematic viscosity of the fluid composition may be approximately selected by mixing various amounts of commercially available polyalphaolefin fractions. FIGS. 3-6 are tables that show various fluid compositions in which different amounts of PAO fractions at various kinematic viscosities at 100° C. may be combined to arrive at a fluid composition having a corresponding overall kinematic viscosity.

[0027]In some embodiments, the viscosity index of the fluid composition may be about, or at least about, one or more of 80, 85, 90, 94, 95, 100, 105, 110, 115, 120, 125, 130, 135, 137, 140, 150, 175, 200, 250, 300, 350, or 400, or a range between any two of the preceding values, for example, between about 80 and 400. The viscosity index may be determined according to that described for synthetic fluids in ASTM D4638 (American Society for Testing Materials, West Conshohocken, Pa.).

Problems solved by technology

Lubricants and functional fluids used in submarine propulsion systems may encounter challenging operating conditions in terms of pressure, wear, service life, and the like.

If a problem occurs with a submarine at sea, the chances for outside assistance may be remote.

This oil has been used in submarines for the past forty years, but the U.S. Navy has increased the severity of the operating conditions in its fleet.

The net result of these more stressful operating conditions is that the existing 2190-TEP fluid is failing more quickly leading to high oil replacement and high disposal costs.

Problems observed in conjunction with these more stressful operating conditions include (a) high depletion of antioxidants in the mineral oil based 2190-TEP fluid, (b) sharp increases in total acid number and (c) severe off-gassing events.

Degradation leads to the formation of components such as formaldehyde and carbon monoxide that can be particularly hazardous in the close operating conditions of the submarine.

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