Lubricants with improved low temperature, oxidation, and deposit control performance

Abstract

A method of making an anti-deposit fluid includes combining a base oil and one or more additives to form a blended fluid configured to remain flowable in a low temperature environment and resist formation of deposits in an oxidizing environment. The base oil has a viscosity index of at least 80 and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base oil includes greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and at least 1.7 total end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms.

Description

TECHNICAL FIELD

[0001] Embodiments of the present invention relate generally to fluids such as lubricants manufactured from base stocks. BACKGROUND

[0002] There is a continuing drive to improve the performance of designed fluids such as finished lubricants. Exposure to high temperatures, typically in the presence of oxygen, metals and water, can cause oxidation and degradation of the lubricant. Exposure to shear forces, as well as extreme high and low temperatures, can cause the lubricant to degrade and become ineffective in its role in the management of friction and heat transfer. The operating efficiency of machines and mechanisms using degraded lubricants is sub-optimal and there is a risk of damage. Therefore, it is preferable to drain and replace lubricants on a regular basis, typically at predetermined intervals. At such times, users of the affected machines lose productivity as the machines are taken out of service and incur costs associated with the materials, service and waste disposal aspects of replacing the lubricant. For applications where the affected equipment is difficult to access, such as turbines located at sea, these detrimental aspects are magnified. SUMMARY

[0003] In one embodiment, a method of manufacturing an anti-deposit fluid configured for use in a low temperature environment includes combining a base stock with one or more additives to form a blended fluid configured to be pumpable in a low temperature environment and resistant to forming deposits in an oxidizing environment. The base stock has a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock includes greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms.

[0004] In another embodiment, a method of manufacturing an anti-deposit fluid configured for use in a low temperature environment includes combining a base stock with one or more additives to form a blended fluid configured to be pumpable in a low temperature environment and resistant to forming deposits in an oxidizing environment. The low temperature environment includes temperatures as low as -30°C. The base stock has a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock includes greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms.

[0005] In another embodiment, a method of making an anti-deposit fluid configured for use in a low temperature environment includes combining a base stock with one or more additives to form a blended fluid configured to be pumpable in a low temperature environment and resistant to forming deposits in an oxidizing environment. The oxidizing environment includes temperatures up to 325°F (163°C). The base stock has a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock includes greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms.

[0006] In another embodiment, an anti-deposit fluid configured for use in a low temperature environment includes a base stock and one or more additives. The base stock has a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock includes greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms. The anti-deposit fluid is configured to be pumpable in a low temperature environment and resistant to forming deposits in an oxidizing environment.

[0007] In another embodiment, an anti-deposit fluid configured for use in a low temperature environment includes a base stock and one or more additives. The base stock has a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock includes greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms. The anti-deposit fluid is configured to be pumpable in a low temperature environment and resistant to forming deposits in an oxidizing environment. The low temperature environment includes temperatures as low as -30°C.

[0008] In another embodiment, an anti-deposit fluid configured for use in a low temperature environment includes a base stock and one or more additives. The base stock has a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock includes greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms. The anti-deposit fluid is configured to be pumpable in a low temperature environment and resistant to forming deposits in an oxidizing environment. The oxidizing environment includes temperatures up to 325°F (163°C).

[0009] In another embodiment, an anti-deposit fluid configured for use in a low temperature environment includes a base stock and one or more additives. The base stock has a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock includes greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms. The anti-deposit fluid is configured to be pumpable in a low temperature environment and resistant to forming deposits in an oxidizing environment. The low temperature environment includes temperatures as low as -30°C. The oxidizing environment includes temperatures up to 325°F (163°C). BRIEF DESCRIPTION OF DRAWINGS

[0010] So that the manner in which the above recited features of the present application can be understood in detail, a brief description of the application summarized above can be had by reference to embodiments. Certain aspects of some embodiments are set forth with particularity herein. It should be noted, however, that the accompanying drawings are included to provide a further understanding of example embodiments and are not intended for purposes of limitation to the scope of the present application. Embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings in which:

[0011] Figure 1 FIG. 1 is a graph illustrating comparative test results of a fluid of the present application and a lubricant blended from a high viscosity Group I base stock, measured according to the ASTM D2893 U.S. Steel Oxidation Test, according to one embodiment.

[0012] Figure 2 FIG. 1 is a graph illustrating comparative test results of a fluid of the present application and a lubricant blended from a high viscosity Group I base stock, measured according to the ASTM D2893 U.S. Steel Oxidation Test, according to one embodiment.

[0013] Figure 3FIG. 1 is a graph illustrating comparative test results of fluids of the present invention and lubricants blended from high viscosity Group I base stocks measured according to ASTM D4684 MRV Apparent Viscosity Test, according to one embodiment.

[0014] Figure 4 FIG. 1 is a graph illustrating comparative test results of fluids of the present invention and lubricants blended from high viscosity Group I base stocks measured according to ASTM D4684 MRV Apparent Viscosity Test, according to one embodiment.

[0015] Figure 5 FIG. 1 is a graph illustrating comparative test results of fluids of the present invention and lubricants blended from high viscosity Group I base stocks measured according to ASTM D4684 MRV Apparent Viscosity Test, according to one embodiment.

[0016] Figure 6 FIG. 1 is a graph illustrating comparative test results of fluids of the present invention and lubricants blended from high viscosity Group I base stocks measured according to ASTM D4684 MRV Apparent Viscosity Test, according to one embodiment.

[0017] For ease of understanding, the same reference numbers will be used in different drawings to designate the same or similar elements shared by the drawings. It can be conceived that elements and features of one embodiment can be beneficially incorporated into other embodiments without further recitation. DETAILED DESCRIPTION

[0018] Fluids used as lubricants are manufactured by blending one or more base stocks with one or more additives. The properties of such fluids, such as the viscosity of the fluid, can be controlled by selecting different base stocks and different types and / or amounts of additives. The base stocks of the present invention can be used to blend fluids having better properties than other fluids. For example, the fluids of the present invention can have improved oxidation performance and / or improved low temperature performance and / or improved deposit control and / or improved heat transfer performance compared to other fluids.

[0019] There is a need for improved designed fluids, particularly lubricants, to improve performance at extreme low and high temperatures. It would also be beneficial to increase the time interval between successive lubricant changes without sacrificing the lubricating performance of the lubricant. The present invention relates to fluids blended from base stocks comprising high viscosity Group II base stocks, particularly high viscosity Group II bright stock.

[0020] Base stocks can be used to make fluids such as automotive lubricating oils, industrial lubricants, and greases. Base stocks can also be used in process oils, white oils, metal working oils, and heat transfer fluids. Blends of base stocks can also be referred to as "base oils." Finished lubricants typically include one or more base stocks and additives. The base stock components can be the major components in these finished lubricants and can significantly influence the performance of the finished lubricants. In general, a range of finished lubricants is manufactured using some lubricating base stocks by varying the mix of individual base stocks and individual additives.

[0021] Base stocks are classified according to their saturate content (expressed as a weight percent (wt%) ), sulfur content (wt%), and viscosity index according to the American Petroleum Institute (API) classification (see Table 1). Lubricant base stocks are typically manufactured in large scale from petroleum resources. Group I, II, and III base stocks are derived from crude oils by processes such as solvent extraction, hydroprocessing, solvent or catalytic dewaxing, and hydroisomerization. Group III base stocks can also be manufactured from synthetic hydrocarbon liquids obtained from natural gas, coal, or other fossil resources; Group IV base stocks, polyalphaolefins (PAOs), are manufactured by oligomerization of alpha-olefins such as 1-decene; Group V base stocks include all materials not falling into Groups I to IV, such as naphthenic oils, polyalkylene glycols (PAGs), and esters.

[0022] Table 1

[0023]

[0024] Group II base stocks can have at least one property enhanced relative to the Group II minimum specification. The enhanced property can be, for example, a viscosity index that is significantly greater than 80 of the Group II specification. Such Group II base stocks can have a viscosity index of at least 90 or at least 95 or at least 100, at least 103 or at least 108 or at least 113.

[0025] The Group II high viscosity base stocks of the present application can have a higher viscosity than conventional Group II base stocks. The Group II high viscosity base stocks of the present application can have a kinematic viscosity at 100°C of at least 14 cSt or at least 20 cSt or at least 25 cSt or at least 30 cSt or at least 32 cSt; can contain less than 10 wt% aromatics, greater than 90 wt% saturates, and / or less than 0.03 wt% sulfur. The saturates content can be higher, for example, greater than 95 wt% or greater than 97 wt%. Such Group II base stocks are typically clear and bright. In at least one embodiment, the Group II base stocks have one or more of the following properties: a viscosity index of at least 80, an aromatics content of less than 10 wt%, a sulfur content of less than 300 wppm, a kinematic viscosity at 100°C of at least 14 cSt, a kinematic viscosity at 40°C of at least 320 cSt, a pour point of -9°C or lower, and / or a cloud point of -2°C or lower. In at least one embodiment, the Group II base stocks have a viscosity index of at least 95 and / or a kinematic viscosity at 100°C of 30 cSt to 40 cSt. The Group II base stocks of the present application can have a pour point of -10°C or lower, for example, -20°C or lower or -25°C to -30°C. The Group II base stocks of the present application can have a T10 distillation point of at least 482°C.

[0026] Group II base stocks having a kinematic viscosity at 100°C of 29 cSt to 32 cSt or more can be advantageous, for example, in certain applications where such base stocks can be used as a substitute for conventional Group I bright stock. Additionally or alternatively, Group II base stocks having a kinematic viscosity at 100°C of 29 cSt to 32 cSt or more can be advantageous in applications where Group I bright stock can not be suitable, for example, in environments where Group I bright stock has difficulty in oxidative stability performance.

[0027] The Group II high viscosity base stocks of the present application can be derived from low severity deasphalting of a residual fraction to form a deasphalted oil. The deasphalted oil can be demetallized, hydrotreated, hydrocracked, hydrodewaxed, and hydrofinished to produce a high saturates base stock having a viscosity range equivalent to conventional Group I bright stock. However, the resulting base stock can be a Group II high viscosity base stock having improved color, lower pour point, equivalent or higher viscosity index, and higher saturates content than Group I bright stock.

[0028] In at least one embodiment, the Group II base stock has a kinematic viscosity at 40°C of about 480 cSt, a kinematic viscosity at 100°C of about 33 cSt, a viscosity index of about 100, an emulsion time at 82°C of about 15 minutes, a pour point of about -21°C, and a saturates content of about 99 wt.%. Table 2 provides a comparison of properties of an example Group II base stock to typical values for a Group I bright stock.

[0029] Table 2

[0030]

[0031] Accordingly, the Group II high viscosity base stock of the present application can be suitable for use in lubricant blends as a replacement for existing Group I bright stocks.

[0032] Overview of Group II base stock

[0033] Group II lubricant base stocks, including Group II bright stocks, can be made from low severity C 4+ deasphalting under conditions that result in a high deasphalted oil yield (and / or a reduced amount of waste asphalt or residual oil), such as a deasphalted oil yield of at least 50 wt.% or at least 55 wt.% or at least 60 wt.% or at least 65 wt.% or at least 70 wt.% or at least 75 wt.% relative to the deasphalting feed. The Group I base stocks, including bright stocks, can be formed without solvent extraction of the deasphalted oil. The Group II base stocks, including bright stocks, can be formed using a combination of catalytic and solvent processing. The Group I and Group II bright stocks of the present application can be substantially haze-free upon long term storage, as compared to conventional bright stocks made from deasphalted oils formed under low severity conditions.

[0034] In various additional aspects, methods for catalytically processing C3 deasphalted oil to form Group II bright stocks are provided. Forming Group II bright stocks by catalytic processing can provide bright stocks having improved compositional properties.

[0035] Generally, crude oil is often described as comprising a variety of boiling ranges. The lower boiling range compounds in crude oil correspond to naphtha or kerosene fuels. The middle boiling range distillate compounds can be used as diesel fuel or lubricant base stocks. If any higher boiling range compounds are present in the crude oil, such compounds are considered residual or "resid" compounds, corresponding to the portion of the crude oil that remains after atmospheric and / or vacuum distillation of the crude oil.

[0036] In some processing approaches, a residue fraction can be deasphalted, with the deasphalted oil used as part of the feed to form a lubricant base stock. The deasphalted oil used as feed to form a lubricant base stock is manufactured using propane deasphalting. Such propane deasphalting corresponds to a "high severity" deasphalting, as indicated by a typical yield of deasphalted oil relative to the initial residue fraction of about 40 wt% or less, often 30 wt% or less. In a typical lubricant base stock manufacturing process, the deasphalted oil can then be subjected to solvent extraction to reduce aromatic content, and then solvent dewaxing to form a base stock. The low yield of deasphalted oil is in part due to conventional methods being unable to manufacture a lubricant base stock from a lower severity deasphalting that does not form haze over time.

[0037] In some aspects, it has been discovered that using a mixture of catalytic processing, such as hydroprocessing, and solvent processing, such as solvent dewaxing, can be used to manufacture lubricant base stocks from deasphalted oil while also manufacturing base stocks that have little or no tendency to form haze over long periods of time. The deasphalted oil can be manufactured by using a C4 solvent, a C5 solvent, a mixture of two or more C4 solvents, or a mixture of two or more C5 solvents. 6+ solvent, a mixture of two or more C 4+ solvents, or a mixture of two or more C 5+ solvents. The deasphalting process can also correspond to a deasphalted oil yield process having at least 50 wt% deasphalted oil yield, or at least 60 wt% or at least 65 wt% or at least 70 wt% or at least 75 wt% deasphalted oil yield for a vacuum residue feed having a T10 distillation point (or T5 distillation point) of at least 400°C or at least 510°C. It is believed that the reduced haze formation is in part due to a reduction or minimization of the difference between the pour point and the cloud point of the base stock and / or is in part due to the formation of a bright stock having a cloud point of -2°C or less or -5°C or less.

[0038] For production of Group II base stocks, in some aspects, the deasphalted oil can be subjected to hydroprocessing (hydrotreating and / or hydrocracking) such that the conversion at about 700°F+(370°C+) is from 10 wt% to 40 wt%. The effluent of the hydroprocessing can be fractionated to separate a lower boiling portion from a lubricant base stock boiling range portion. The lubricant boiling range portion can then be hydrocracked, dewaxed, and hydrofinished to produce a catalytically dewaxed effluent. In some embodiments, the lubricant boiling range portion can be underdewaxed such that the catalytically dewaxed heavier portion or potential bright stock portion of the effluent has a wax content of at least 6 wt% or at least 8 wt% or at least 10 wt%. This underdewaxing can also be suitable for forming a light or medium or heavy neutral lubricant base stock that does not require further solvent upgrading to form a haze-free base stock. In this discussion, the heavier portion / potential bright stock portion can correspond generally to the 538°C+ portion of the dewaxed effluent. The catalytically dewaxed heavier portion of the effluent can then be solvent treated by solvent dewaxing to form a solvent dewaxed effluent. The solvent dewaxed effluent can be separated to form a plurality of base stocks that have a reduced tendency (e.g., no tendency) to form haze over time, including at least a portion of a Group II bright stock product.

[0039] For production of Group II base stocks, in other aspects, the deasphalted oil can be subjected to hydroprocessing (hydrotreating and / or hydrocracking) such that the conversion at 370°C+ is at least 40 wt% or at least 50 wt%. The effluent of the hydroprocessing can be fractionated to separate a lower boiling portion from a lubricant base stock boiling range portion. The lubricant base stock boiling range portion can then be hydrocracked, dewaxed, and hydrofinished to produce a catalytically dewaxed effluent. The catalytically dewaxed effluent can then be solvent extracted to form a raffinate. The raffinate can be separated to form a plurality of base stocks that have a reduced tendency (e.g., no tendency) to form haze over time, including at least a portion of a Group II bright stock product. In still other aspects, the Group II bright stock product can be formed without further solvent treatment after catalytic dewaxing.

[0040] In other aspects, it has been found that catalytic treatment can be used to produce a Group II bright stock from C3, C4, C5, and / or C 5+ Production of Group II bright stock with improved compositional properties from deasphalted oil. The deasphalted oil can be hydrotreated to reduce the content of heteroatoms (e.g., sulfur and nitrogen) and then catalytically dewaxed under low sulfur conditions. In some embodiments, hydrocracking can be included as part of the acidic hydrotreating stage and / or as part of the low sulfur dewaxing stage.

[0041] In various aspects, various combinations of catalytic and / or solvent processing can be used for lubricant base stocks formed from deasphalted oil, including Group II bright stock. These combinations include, but are not limited to:

[0042] a) hydroprocessing of deasphalted oil under acidic conditions (i.e., sulfur content of at least 500 wppm); separation of the effluent of the hydroprocessing to form at least a lubricant boiling range fraction, and solvent dewaxing of the lubricant boiling range fraction. In some aspects, the hydroprocessing of the deasphalted oil can correspond to hydrotreating, hydrocracking, or a combination thereof.

[0043] b) hydroprocessing of deasphalted oil under acidic conditions (i.e., sulfur content of at least 500 wppm); separation of the effluent of the hydroprocessing to form at least a lubricant boiling range fraction; and catalytic dewaxing of the lubricant boiling range fraction under low sulfur conditions (i.e., 500 wppm or less sulfur). The catalytic dewaxing can correspond to catalytic dewaxing using a dewaxing catalyst having a pore size greater than 8.4 Angstroms. In some embodiments, the low sulfur processing conditions can further include hydrocracking, noble metal hydrotreating, and / or hydrofinishing. The optional hydrocracking, noble metal hydrotreating, and / or hydrofinishing can be performed before and / or after or after the catalytic dewaxing. For example, the sequence of catalytic processing under low sulfur processing conditions can be noble metal hydrotreating followed by hydrocracking followed by catalytic dewaxing.

[0044] c) the process of b) above followed by additional separation of at least a portion of the catalytically dewaxed effluent. The additional separation can correspond to solvent dewaxing, solvent extraction (e.g., solvent extraction with furfural or n-methyl pyrrolidone), physical separation such as ultracentrifugation, or a combination thereof.

[0045] d) the process of a) above followed by catalytic dewaxing (low sulfur conditions) of at least a portion of the solvent dewaxed product. In some embodiments, the low sulfur processing conditions can further include hydrotreating (e.g., noble metal hydrotreating), hydrocracking, and / or hydrofinishing. The additional low sulfur hydroprocessing can be performed before and / or after the catalytic dewaxing.

[0046] In the following discussion, a stage can correspond to a single reactor or multiple reactors. In some embodiments, multiple parallel reactors can be used to perform one or more processes, or multiple parallel reactors can be used for all processes in a stage. The various stages and / or reactors can contain one or more catalyst beds containing a hydroprocessing catalyst. It should be noted that a catalyst "bed" in the following discussion can refer to a partial physical catalyst bed. For example, a catalyst bed within a reactor can be partially filled with a hydrocracking catalyst and partially filled with a dewaxing catalyst. For ease of description, even though the two catalysts can be stacked together in a single catalyst bed, the hydrocracking catalyst and the dewaxing catalyst can be conceptually referred to as separate catalyst beds.

[0047] In this discussion, conditions can be provided for various types of hydroprocessing of the feed or effluent. Examples of hydroprocessing can include, but are not limited to, one or more of hydrotreating, hydrocracking, catalytic dewaxing, and hydrofining / aromatic saturation. Such hydroprocessing conditions can be controlled by using at least one controller, e.g., a plurality of controllers, to control one or more hydroprocessing conditions. The hydroprocessing conditions can be controlled such that the conditions (e.g., temperature, pressure, liquid hourly space velocity, treat gas rate) have desired values. In some aspects, for a given type of hydroprocessing, at least one controller can be associated with each type of hydroprocessing condition. In some aspects, one or more hydroprocessing conditions can be controlled by an associated controller. Examples of structures that can be controlled by a controller can include, but are not limited to, valves that control flow rate, pressure, or combinations thereof; heat exchangers and / or heaters that control temperature; and one or more flow meters and one or more associated valves that control the relative flow rates of at least two streams. Such a controller can comprise a controller feedback loop containing at least one processor, a detector for detecting the value of a control variable (e.g., temperature, pressure, flow rate), and a processor output for controlling the value of a manipulated variable (e.g., changing the position of a valve, increasing or decreasing the duty cycle, and / or the temperature of a heater). In some embodiments, at least one hydroprocessing condition for a given type of hydroprocessing can be free of an associated controller.

[0048] In the present discussion, unless otherwise indicated, a lubricant boiling range fraction corresponds to a fraction having an initial boiling point of at least about 370°C (about 700°F) or alternatively a T5 boiling point. Distillate fuel boiling range fractions, such as diesel product fractions, correspond to fractions having a boiling range of about 193°C (375°F) to about 370°C (about 700°F). As such, a distillate fuel boiling range fraction (e.g., a distillate fuel product fraction) can have an initial boiling point (or alternatively a T5 boiling point) of at least about 193°C and a final boiling point (or alternatively a T95 boiling point) of about 370°C or less. Naphtha boiling range fractions correspond to fractions having a boiling range of about 36°C (122°F) to about 193°C (375°F) to about 370°C (about 700°F). As such, a naphtha fuel product fraction can have an initial boiling point (or alternatively a T5 boiling point) of at least about 36°C and a final boiling point (or alternatively a T95 boiling point) of about 193°C or less. Notably, 36°C approximately corresponds to the boiling point of various isomers of C5alkanes. A fuel boiling range fraction can correspond to a distillate fuel boiling range fraction, a naphtha boiling range fraction, or a fraction comprising both distillate fuel boiling range and naphtha boiling range components. A light fraction is defined as a product having a boiling point below about 36°C, which includes various C1-C4compounds. When determining the boiling point or boiling range of a feed or product fraction, an appropriate ASTM test method can be used, such as the procedures described in ASTM D2887, D2892, and / or D86. ASTM D2887 should be used unless the sample is not suitable for characterization according to ASTM D2887. For example, for samples that do not elute completely from the chromatographic column, ASTM D7169 can be used.

[0049] Feedstock

[0050] In various aspects, at least a portion of the feedstock for processing as described herein can correspond to a vacuum resid fraction or another type of 950°F+ (510°C+) or 1000°F+ (538°C+) fraction. Another example of a process to form a 950°F+ (510°C+) or 1000°F+ (538°C+) fraction is to perform a high temperature flash separation. The 950°F+ (510°C+) or 1000°F+ (538°C+) fraction formed by high temperature flashing can be processed in a manner similar to vacuum resid.

[0051] The vacuum resid fraction or 950°F+ (510°C+) fraction formed by another process, such as flash distillation of oil foots or pitch fraction, can be deasphalted at low severity to form a deasphalted oil. In some embodiments, the feedstock can also include a portion of conventional feed for lubricant base stock manufacture, such as vacuum gas oil.

[0052] A vacuum resid (or other 510°C+) fraction can correspond to a fraction having a T5 distillation point of at least about 900°F (482°C) or at least 950°F (510°C) or at least 1000°F (538°C) (ASTM D2892; or ASTM D7169 if the fraction does not elute completely from the chromatographic system). Alternatively, a vacuum resid fraction can be characterized based on a T10 distillation point of at least about 900°F (482°C) or at least 950°F (510°C) or at least 1000°F (538°C) (ASTM D2892 / D7169).

[0053] The metal content of a resid (or other 510°C+) fraction can be high. For example, the total content of nickel, vanadium, and iron of a resid fraction can be high. In one aspect, a resid fraction can contain at least 0.00005 grams of Ni / V / Fe (50 wppm) or at least 0.0002 grams of Ni / V / Fe (200 wppm) per gram of resid, based on the total elements of nickel, vanadium, and iron. In other aspects, a heavy oil can contain at least 500 wppm of nickel, vanadium, and iron, for example, up to 1000 wppm or more.

[0054] Contaminants such as nitrogen and sulfur are often present in a resid (or other 510°C+) fraction, often in organically bound form. The nitrogen content can be about 50 wppm to about 10,000 wppm elemental nitrogen or more, based on the total weight of the resid fraction. The sulfur content can be 500 wppm to 100,000 wppm elemental sulfur or more, or 1000 wppm to 50,000 wppm or 1000 wppm to 30,000 wppm, based on the total weight of the resid fraction.

[0055] Yet another way to characterize a resid (or other 510°C+) fraction is based on the Conradson Carbon (CCR) of the feedstock. The Conradson Carbon of a resid fraction can be at least about 5 wt%, for example, at least about 10 wt% or at least about 20 wt%. Additionally or alternatively, the Conradson Carbon of a resid fraction can be about 50 wt% or less, for example, about 40 wt% or less or about 30 wt% or less.

[0056] In some aspects, a vacuum gas oil fraction can be co-processed with the deasphalted oil. The vacuum gas oil can be combined with the deasphalted oil in various amounts from 20 parts (by weight) of deasphalted oil to 1 part of vacuum gas oil (i.e., 20: 1) to 1 part of deasphalted oil to 1 part of vacuum gas oil. In some aspects, the ratio of deasphalted oil to vacuum gas oil can be at least 1 : 1 (by weight) or at least 1.5: 1 or at least 2: 1. A typical (vacuum) gas oil fraction can include a fraction having a T5 distillation point to T95 distillation point of 650 °F to 1050 °F (343 °C to 566 °C), or 650 °F to 1000 °F (343 °C to 538 °C), or 650 °F to 950 °F (343 °C to 510 °C), or 650 °F to 900 °F (343 °C to 482 °C), or about 700 °F to 1050 °F (370 °C to 566 °C), or about 700 °F to 1000 °F (370 °C to 538 °C), or about 700 °F to 950 °F (370 °C to 510 °C), or about 700 °F to 900 °F (370 °C to 482 °C), or 750 °F to 1050 °F (399 °C to 566 °C), or 750 °F to 1000 °F (399 °C to 538 °C), or 750 °F to 950 °F (399 °C to 510 °C), or 750 °F to 900 °F (399 °C to 482 °C). For example, a suitable vacuum gas oil fraction can have a T5 distillation point of at least 343 °C and a T95 distillation point of 566 °C or less; or a T10 distillation point of at least 343 °C and a T90 distillation point of 566 °C or less; or a T5 distillation point of at least 370 °C and a T95 distillation point of 566 °C or less; or a T5 distillation point of at least 343 °C and a T95 distillation point of 538 °C or less.

[0057] Solvent deasphalting

[0058] Solvent deasphalting is a solvent extraction process. In some aspects, suitable solvents for use in the processes described herein include alkanes or other carbon hydrocarbons (e.g., olefins) containing 4 to 7 carbons per molecule. Examples of suitable solvents include n-butane, isobutane, n-pentane, C 4+ alkanes, C 5+ alkanes, C 4+ hydrocarbons, and C 5+ hydrocarbons. In other aspects, suitable solvents can include C3 hydrocarbons, such as propane. In such other aspects, examples of suitable solvents include propane, n-butane, isobutane, n-pentane, C 3+ alkanes, C 4+ alkanes, C 5+ alkanes, C 3+ hydrocarbons, C 4+ hydrocarbons, and C 5+ hydrocarbons.

[0059] In this discussion, the deasphalted oil will include C nA solvent of (hydrocarbons) is defined as a solvent comprising at least 80 wt% or at least 85 wt% or at least 90 wt% or at least 95 wt% or at least 98 wt% of an alkane (hydrocarbon) having n carbon atoms. Similarly, a solvent comprising C n+ A solvent of (hydrocarbons) is defined as a solvent comprising at least 80 wt% or at least 85 wt% or at least 90 wt% or at least 95 wt% or at least 98 wt% of an alkane (hydrocarbon) having n or more carbon atoms.

[0060] In this discussion, a solvent comprising C n A solvent of (hydrocarbons) is defined as including cases where the solvent corresponds to a single alkane (hydrocarbon) containing n carbon atoms (e.g., n = 3, 4, 5, 6, 7) and cases where the solvent comprises a mixture of alkanes (hydrocarbons) containing n carbon atoms. Similarly, a solvent comprising C n+ A solvent of (hydrocarbons) is defined as including cases where the solvent corresponds to a single alkane (hydrocarbon) containing n or more carbon atoms (e.g., n = 3, 4, 5, 6, 7) and cases where the solvent corresponds to a mixture of alkanes (hydrocarbons) containing n or more carbon atoms. Thus, a solvent comprising C 4+ A solvent of alkanes can correspond to a solvent comprising n-butane; a solvent comprising n-butane and iso-butane; a solvent corresponding to a mixture of one or more butane isomers and one or more pentane isomers; or any other convenient combination of alkanes containing 4 or more carbon atoms. Similarly, a solvent comprising C 5+ A solvent of (hydrocarbons) is defined as including solvents corresponding to a single alkane (hydrocarbon) or solvents corresponding to a mixture of alkanes (hydrocarbons) containing 5 or more carbon atoms. Alternatively, other types of solvents can also be suitable, such as supercritical fluids. In various aspects, a solvent for solvent deasphalting can consist essentially of hydrocarbons, such that at least 98 wt% or at least 99 wt% of the solvent corresponds to compounds containing only carbon and hydrogen. In aspects where the deasphalting solvent corresponds to C 4+ In aspects of the deasphalting solvent, C 4+ The deasphalting solvent can comprise less than 15 wt% or less than 10 wt% or less than 5 wt% of propane and / or other C3 hydrocarbons, or C 4+ The deasphalting solvent can consist essentially of no propane and / or other C3 hydrocarbons (less than 1 wt%). In aspects where the deasphalting solvent corresponds to C 5+ In aspects of the deasphalting solvent, C 5+ The deasphalting solvent can comprise less than 15 wt% or less than 10 wt% or less than 5 wt% of propane, butane and / or other C3-C4 hydrocarbons, or C 5+The deasphalting solvent can be substantially free of propane, butane, and / or other C3-C4 hydrocarbons (less than 1 wt %). In deasphalting solvents corresponding to C 3+ The deasphalting solvent can be substantially free of propane, butane, and / or other C3-C4 hydrocarbons (less than 1 wt %). In deasphalting solvents corresponding to C 3+ The deasphalting solvent can contain less than 10 wt % or less than 5 wt % of ethane and / or other C2 hydrocarbons, or the deasphalting solvent can be substantially free of ethane and / or other C2 hydrocarbons (less than 1 wt %). 3+ The deasphalting solvent can contain less than 10 wt % or less than 5 wt % of ethane and / or other C2 hydrocarbons, or the deasphalting solvent can be substantially free of ethane and / or other C2 hydrocarbons (less than 1 wt %).

[0061] Deasphalting of heavy hydrocarbons such as vacuum residue is known in the art and practiced commercially. Deasphalting processes generally correspond to contacting a heavy hydrocarbon with an alkane solvent (propane, butane, pentane, hexane, heptane, etc. and isomers thereof) in pure form or in a mixture to produce two types of product streams. One type of product stream can be a deasphalted oil via alkane extraction, which is additionally separated to produce a deasphalted oil stream. The second type of product stream can be the residual portion of the feed that is insoluble in the solvent, often referred to as a residual oil or asphaltene fraction. The deasphalted oil fraction can be additionally processed into fuels or lubricants. The residual oil fraction can be additionally used as a blending component to make asphalt, fuel oil, and / or other products. The residual oil fraction can also be used as a feed to gasification processes such as partial oxidation, fluidized bed combustion, or coking processes. The residual oil can be transported to these processes in the form of a liquid (with or without additional components) or a solid (pellets or chunks).

[0062] During solvent deasphalting, the residue boiling range feed (optionally also including a portion of the vacuum gas oil feed) can be mixed with a solvent. The solvent-soluble portion of the feed is then extracted, leaving a residue that is nearly or not soluble in the solvent. The deasphalted feed portion that is extracted with the solvent is often referred to as deasphalted oil. Typical solvent deasphalting conditions include mixing the feedstock fraction with the solvent at a weight ratio of about 1 :2 to about 1 : 10, such as about 1 :8 or lower. Typical solvent deasphalting temperature ranges are 40 °C to 200 °C or 40 °C to 150 °C, depending on the nature of the feed and solvent. The pressure during solvent deasphalting can be about 50 psig (345 kPag) to about 500 psig (3447 kPag).

[0063] It is noted that the above solvent deasphalting conditions represent general ranges, and conditions will vary depending on the feed. For example, under typical deasphalting conditions, increasing temperature tends to increase the quality of the resulting deasphalted oil while decreasing yield. Under typical deasphalting conditions, increasing the molecular weight of the solvent tends to decrease the quality of the resulting deasphalted oil while increasing yield, as other compounds within the residual fraction can be soluble in solvents comprising higher molecular weight hydrocarbons. Under typical deasphalting conditions, increasing the amount of solvent tends to increase the yield of the resulting deasphalted oil. As understood by one skilled in the art, conditions for a particular feed can be selected based on the resulting yield of deasphalted oil from solvent deasphalting. In aspects using a C3 deasphalting solvent, the yield of solvent deasphalting can be 40 wt% or less. In some aspects, C4 deasphalting can be performed with a deasphalted oil yield of 50 wt% or less or 40 wt% or less. In various aspects, the deasphalted oil derived from solvent deasphalting with a C3 solvent can have a 950 °F+ (510 °C) portion of at least 50 wt% or at least 55 wt% or at least 60 wt% or at least 65 wt% or at least 70 wt%. 4+ The yield of deasphalted oil from solvent deasphalting relative to the weight of the deasphalted feed can be at least 50 wt% or at least 55 wt% or at least 60 wt% or at least 65 wt% or at least 70 wt%. In aspects where the deasphalted feed comprises a vacuum gas oil portion, the yield from solvent deasphalting can be characterized based on the yield of the 950 °F+ (510 °C) portion of the deasphalted oil relative to the weight of the 510 °C+ portion of the feed. In aspects using a C3 solvent for solvent deasphalting, the yield of 510 °C+ deasphalted oil from solvent deasphalting relative to the weight of the 510 °C+ portion of the deasphalted feed can be at least 40 wt% or at least 50 wt% or at least 55 wt% or at least 60 wt% or at least 65 wt% or at least 70 wt%. 4+ The yield of 510 °C+ deasphalted oil from solvent deasphalting relative to the weight of the 510 °C+ portion of the deasphalted feed can be at least 40 wt% or at least 50 wt% or at least 55 wt% or at least 60 wt% or at least 65 wt% or at least 70 wt% in aspects using a C3 solvent for solvent deasphalting. 4+ The yield of 510 °C+ deasphalted oil from solvent deasphalting relative to the weight of the 510 °C+ portion of the deasphalted feed can be at least 40 wt% or at least 50 wt% or at least 55 wt% or at least 60 wt% or at least 65 wt% or at least 70 wt% in aspects using a C3 solvent for solvent deasphalting.

[0064] Hydrotreating and hydrocracking

[0065] Following deasphalting, the deasphalted oil (and any other fractions combined with the deasphalted oil) can be subjected to additional processing to form a lubricant base stock. This can include hydroprocessing and / or hydrocracking to remove heteroatoms to a desired level, to reduce Conradson Carbon content, and / or to provide a viscosity index (VI) boost. According to the aspects, the deasphalted oil can be subjected to hydroprocessing by hydroprocessing, hydrocracking, or both hydroprocessing and hydrocracking.

[0066] The deasphalted oil can be hydrotreated and / or hydrocracked prior to and / or after deasphalting with little or no solvent extraction. As a result, the deasphalted oil feed for hydrotreating and / or hydrocracking can have a substantial aromatic compound content. In various aspects, the deasphalted oil feed can have an aromatic compound content of at least 50 wt% or at least 55 wt% or at least 60 wt% or at least 65 wt% or at least 70 wt% or at least 75 wt%, for example up to 90 wt% or more. Additionally or alternatively, the deasphalted oil feed can have a saturated compound content of 50 wt% or less or 45 wt% or less or 40 wt% or less or 35 wt% or less or 30 wt% or less or 25 wt% or less, for example as low as 10 wt% or less. In this discussion and claims, the aromatic compound content and / or saturated compound content of a fraction can be determined according to ASTM D7419.

[0067] The reaction conditions in the demetallization and / or hydrotreating and / or hydrocracking of the deasphalted oil (and optional vacuum gas oil co-feed) can be selected to produce a desired level of feed conversion. Any convenient type of reactor can be used, such as a fixed bed (e.g., trickle bed) reactor. Conversion of the feed can be defined in terms of conversion of molecules having a boiling point above a temperature threshold to molecules having a boiling point below the threshold. The conversion temperature can be any convenient temperature, such as about 700 °F (370 °C) or 1050 °F (566 °C). The amount of conversion can correspond to the total conversion of molecules in the combined hydrotreating and hydrocracking stages for the deasphalted oil. A suitable amount of conversion of molecules having a boiling point above 1050 °F (566 °C) to molecules having a boiling point below 566 °C includes 30 wt% to 90 wt%, or 30 wt% to 80 wt%, or 30 wt% to 70 wt%, or 40 wt% to 90 wt%, or 40 wt% to 80 wt%, or 40 wt% to 70 wt%, or 50 wt% to 90 wt%, or 50 wt% to 80 wt%, or 50 wt% to 70 wt% conversion relative to 566 °C. In particular, the amount of conversion relative to 566 °C can be 30 wt% to 90 wt%, or 30 wt% to 70 wt%, or 50 wt% to 90 wt%. Additionally or alternatively, a suitable amount of conversion of molecules having a boiling point above about 700 °F (370 °C) to molecules having a boiling point below 370 °C includes 10 wt% to 70 wt%, or 10 wt% to 60 wt%, or 10 wt% to 50 wt%, or 20 wt% to 70 wt%, or 20 wt% to 60 wt%, or 20 wt% to 50 wt%, or 30 wt% to 70 wt%, or 30 wt% to 60 wt%, or 30 wt% to 50 wt% conversion relative to 370 °C. In particular, the amount of conversion relative to 370 °C can be 10 wt% to 70 wt%, or 20 wt% to 50 wt%, or 30 wt% to 60 wt%.

[0068] The hydroprocessed deasphalted oil can also be characterized based on product quality. The sulfur content of the hydroprocessed deasphalted oil after hydroprocessing (hydrotreating and / or hydrocracking) can be 200 wppm or less or 100 wppm or less or 50 wppm or less (e.g., down to about 0 wppm). Additionally or alternatively, the nitrogen content of the hydroprocessed deasphalted oil can be 200 wppm or less or 100 wppm or less or 50 wppm or less (e.g., down to about 0 wppm). Additionally or alternatively, the Conradson Carbon content of the hydroprocessed deasphalted oil can be 1.5 wt% or less or 1.0 wt% or less or 0.7 wt% or less or 0.1 wt% or less or 0.02 wt% or less (e.g., down to about 0 wt%). The Conradson Carbon content can be determined according to ASTM D4530.

[0069] In various aspects, the feed can first be contacted with a demetallization catalyst prior to contacting the feed with a hydrotreating catalyst. The metal concentration (Ni + V + Fe) of the deasphalted oil can be on the order of 10 to 100 wppm. Contacting a conventional hydrotreating catalyst with a feed having a metal content of 10 wppm or more can result in the catalyst deactivating at a faster rate than can be expected in a commercial setting. Contacting a metal-containing feed with a demetallization catalyst prior to the hydrotreating catalyst can allow at least a portion of the metals to be removed by the demetallization catalyst, which can reduce or minimize deactivation of the hydrotreating catalyst and / or other subsequent catalysts in the process scheme. A commercially available demetallization catalyst can be suitable, such as a macroporous amorphous oxide catalyst, which can include Group VI and / or Group VIII non-noble metals to provide some hydrogenation activity.

[0070] In various aspects, the deasphalted oil can be contacted with a hydrotreating catalyst under effective hydrotreating conditions. The catalyst used can include a conventional hydroprocessing catalyst, such as a catalyst including at least one Group VIII non-noble metal (Columns 8 to 10 of the IUPAC Periodic Table of the Elements) such as Fe, Co, and / or Ni; and at least one Group VI metal (Column 6 of the IUPAC Periodic Table of the Elements) such as Mo and / or W. Such hydroprocessing catalysts can include transition metal sulfides impregnated or dispersed on a refractory support or carrier, such as alumina and / or silica. The support or carrier itself typically has no significant / measurable catalytic activity. Catalysts that are essentially free of a carrier or support, often referred to as bulk catalysts, typically have higher volume activities than their supported counterparts.

[0071] The catalyst can be in bulk form or supported form. In addition to alumina and / or silica, other suitable support / carrier materials can include, but are not limited to, zeolites, titania, silica-titania, and titania-alumina. Suitable alumina is porous alumina, for example, gamma or eta alumina having an average pore diameter of 50 to or 75 to a surface area of 100 to 300 m 2 / g or 150 to 250 m 2 / g and a pore volume of 0.25 to 1.0 cm 3 / g or 0.35 to 0.8 cm 3 / g. More generally, any suitable size, shape, and / or pore size distribution of catalyst suitable for hydroprocessing distillate (including lubricant base stock) boiling range feeds in a conventional manner can be used. In some embodiments, the support or carrier material is an amorphous support, for example, a refractory oxide. In some embodiments, the support or carrier material can be free or substantially free of molecular sieves, where substantially free of molecular sieves is defined as a molecular sieve content of less than about 0.01 wt. %.

[0072] The at least one Group VIII non-noble metal in oxide form can generally be present in an amount ranging from about 2 wt. % to about 40 wt. %, for example, about 4 wt. % to about 15 wt. %. The at least one Group VI metal in oxide form can generally be present in an amount ranging from about 2 wt. % to about 70 wt. %, for example, for supported catalysts, in an amount ranging from about 6 wt. % to about 40 wt. % or about 10 wt. % to about 30 wt. %. These weight percents are based on the total weight of the catalyst. Suitable metal catalysts include cobalt / molybdenum (1 to 10% Co in oxide form, 10 to 40% Mo in oxide form), nickel / molybdenum (1 to 10% Ni in oxide form, 10 to 40% Co in oxide form), or nickel / tungsten (1 to 10% Ni in oxide form, 10 to 40% W in oxide form) on alumina, silica, silica-alumina, or titania.

[0073] Hydroprocessing is conducted in the presence of hydrogen. Thus, hydrogen is fed or injected into the vessel or reaction zone or hydroprocessing zone in which the hydroprocessing catalyst resides. Hydrogen contained in a hydrogen "treatment gas" is provided to the reaction zone. The treatment gas, as referred to in the present disclosure, can be pure hydrogen or a hydrogen-containing gas, which is a stream of gas containing hydrogen in an amount sufficient to carry out the intended reactions, and can include one or more other gases (e.g., nitrogen and light hydrocarbons such as methane). The treatment gas stream introduced to the reaction stage can contain at least about 50 vol%, for example, at least about 75 vol% hydrogen. In some embodiments, the hydrogen treatment gas can be substantially free (less than 1 vol%) of impurities such as H2S and NH3, and / or such impurities can be substantially removed from the treatment gas prior to use.

[0074] Hydrogen can be supplied at a rate from about 100 SCF / B (standard cubic feet of hydrogen per barrel of feed) (17 Nm 3 / m 3 ) to about 10,000 SCF / B (1,700 Nm 3 / m 3 ). In some embodiments, the hydrogen is supplied in a range from about 200 SCF / B (34 Nm 3 / m 3 ) to about 2,500 SCF / B (420 Nm 3 / m 3 ). Hydrogen can be supplied to the hydroprocessing reactor and / or reaction zone co-currently with the input feed, or separately to the hydroprocessing zone through a separate gas conduit.

[0075] Hydroprocessing conditions can include a temperature from 200°C to 450°C or 315°C to 425°C; a pressure from 250 psig (1.8 MPag) to 5,000 psig (34.6 MPag) or 300 psig (2.1 MPag) to 3,000 psig (20.8 MPag); a liquid hourly space velocity (LHSV) from 0.1 hr -1 to 10 hr -1 ; and a hydrogen treat rate from 200 scf / B (35.6 m 3 / m 3 ) to 10,000 scf / B (1,781 m 3 / m 3 ) or 500 (89 m 3 / m 3 ) to 10,000 scf / B (1,781 m 3 / m 3 ).

[0076] In various aspects, the deasphalted oil can be contacted with a hydrocracking catalyst under effective hydrocracking conditions. The hydrocracking catalyst typically comprises a sulfided base metal on an acidic support, such as amorphous silica-alumina, a cracking zeolite such as USY, or an acidified alumina. Often these acidic supports are mixed or combined with other metal oxides such as alumina, titania, or silica. Examples of suitable acidic supports include acidic molecular sieves such as zeolites or silicoaluminophosphates. One example of a suitable zeolite is USY, for example a USY zeolite having a unit cell size of 24.30 Angstroms or less. Additionally or alternatively, the catalyst can be a low acidity molecular sieve, for example a USY zeolite having a Si to Al ratio of at least about 20, for example at least about 40 or 50. ZSM-48, for example ZSM-48 having a Si02to Al203ratio of about 110 or less, for example about 90 or less, is another example of a suitable hydrocracking catalyst. Yet another option is to use a combination of USY and ZSM-48. Still other options include one or more of zeolite beta, ZSM-5, ZSM-35, or ZSM-23, alone or in combination with a USY catalyst. Non-limiting examples of metals for the hydrocracking catalyst include a metal or a combination of metals comprising at least one Group VIII metal, for example nickel, nickel-cobalt-molybdenum, cobalt-molybdenum, nickel-tungsten, nickel-molybdenum, and / or nickel-molybdenum-tungsten. Additionally or alternatively, a hydrocracking catalyst with a noble metal can also be used. Non-limiting examples of noble metal catalysts include platinum and / or palladium based catalysts. Support materials that can be used for both noble and non-noble metal catalysts can comprise refractory oxide materials such as alumina, silica, alumina-silica, kieselguhr, diatomaceous earth, magnesia, zirconia, or combinations thereof, with alumina, silica, alumina-silica being the most common.

[0077] When only one hydrogenation metal is present on the hydrocracking catalyst, the amount of the hydrogenation metal can be at least about 0.1 wt%, for example at least about 0.5 wt% or at least about 0.6 wt%, based on the total weight of the catalyst. Additionally or alternatively, when only one hydrogenation metal is present, the amount of the hydrogenation metal can be about 5.0 wt% or less, for example about 3.5 wt% or less, about 2.5 wt% or less, about 1.5 wt% or less, about 1.0 wt% or less, about 0.9 wt% or less, about 0.75 wt% or less, or about 0.6 wt% or less, based on the total weight of the catalyst. Still additionally or alternatively, when more than one hydrogenation metal is present, the total amount of hydrogenation metals can be at least about 0.1 wt%, for example at least about 0.25 wt%, at least about 0.5 wt%, at least about 0.6 wt%, at least about 0.75 wt%, or at least about 1 wt%, based on the total weight of the catalyst. Still more additionally or alternatively, when more than one hydrogenation metal is present, the total amount of hydrogenation metals can be about 35 wt% or less, for example about 30 wt% or less, about 25 wt% or less, about 20 wt% or less, about 15 wt% or less, about 10 wt% or less, or about 5 wt% or less, based on the total weight of the catalyst. In embodiments where the supported metal comprises a noble metal, the amount of noble metal is typically less than about 2 wt%, for example less than about 1 wt%, about 0.9 wt% or less, about 0.75 wt% or less, or about 0.6 wt% or less. It is noted that hydrocracking under acidic conditions is typically performed using a base metal (or multiple base metals) as the hydrogenation metal.

[0078] In various aspects, the selected conditions for hydrocracking for lubricant base stock manufacture can depend on the desired level of conversion, the contaminant content in the input feed to the hydrocracking stage, and other factors as can be practical. For example, the hydrocracking conditions in the first and / or second stages of a single-stage or multi-stage system can be selected to achieve a desired level of conversion in the reaction system. The hydrocracking conditions can be referred to as acidic conditions or low sulfur conditions, depending on the level of sulfur and / or nitrogen present in the feed. For example, a feed having 100 wppm or less of sulfur and 50 wppm or less of nitrogen, for example less than 25 wppm of sulfur and / or less than 10 wppm of nitrogen, represents a feed that is hydrocracked under low sulfur conditions. In various aspects, a thermally cracked residuum, for example a deasphalted oil derived from a thermally cracked residuum, can be hydrocracked. In some aspects, for example aspects that use an optional hydroprocessing step prior to hydrocracking, the thermally cracked residuum can correspond to a low sulfur feed. In other aspects, the thermally cracked residuum can represent a feed that is hydrocracked under acidic conditions.

[0079] Hydrocracking processes under acidic conditions can be conducted at temperatures ranging from about 550°F (288°C) to about 840°F (449°C), hydrogen partial pressures ranging from about 1500 psig to about 5000 psig (10.3 MPag to 34.6 MPag), liquid hourly space velocities of 0.05 h -1 to 10 h -1 and hydrogen treat gas rates ranging from 35.6 m 3 / m 3 to 1781 m 3 / m 3 (200 SCF / B to 10,000 SCF / B). In other embodiments, the conditions can include temperatures ranging from about 600°F (343°C) to about 815°F (435°C), hydrogen partial pressures ranging from about 1500 psig to about 3000 psig (10.3 MPag to 20.9 MPag), and hydrogen treat gas rates ranging from about 213 m 3 / m 3 to about 1068 m 3 / m 3 (1200 SCF / B to 6000 SCF / B). The LHSV can range from about 0.25 h -1 to about 50 h -1 or from about 0.5 h -1 to about 20 h -1 , for example, from about 1.0 h -1 to about 4.0 h -1 .

[0080] In some aspects, a portion of the hydrocracking catalyst can be contained in a second reactor stage. In such aspects, the first reaction stage of the hydroprocessing reaction system can contain one or more hydrotreating and / or hydrocracking catalysts. The conditions in the first reaction stage can be suitable for reducing the sulfur and / or nitrogen content of the feedstock. A separator can then be used between the first and second stages of the reaction system to remove gaseous phase sulfur and nitrogen contaminants. One option for the separator is to simply perform a gas-liquid separation to remove the contaminants. Another option is to use a separator that can perform the separation at a higher temperature, such as a flash separator. Such a high temperature separator can be used, for example, to separate the feed into a portion having a boiling point below a temperature cut point, such as about 350°F (177°C) or about 400°F (204°C), and a portion having a boiling point above the temperature cut point. In this type of separation, the naphtha boiling range portion of the effluent from the first reaction stage can also be removed, thereby reducing the volume of the effluent that is processed in the second or other subsequent stages. Of course, any low boiling point contaminants in the effluent from the first stage will also be separated into the portion having a boiling point below the temperature cut point. If sufficient contaminant removal is performed in the first stage, the second stage can be operated as a "low sulfur" or low contaminant stage.

[0081] Yet another option can be to use a separator between the first and second stages of the hydroprocessing reaction system, which can also perform at least partial fractionation of the effluent from the first stage. In this type of aspect, the effluent from the first hydroprocessing stage can be separated into at least a portion boiling below the distillate (e.g., diesel) fuel range, a portion boiling within the distillate fuel range, and a portion boiling above the distillate fuel range. The distillate fuel range can be defined based on a conventional diesel boiling range, such as having a lower end cut point temperature of at least about 350°F (177°C) or at least about 400°F (204°C) to an upper end cut point temperature of about 700°F (371 °C) or lower or 650°F (343°C) or lower. In some embodiments, the distillate fuel range can be extended to include additional kerosene, for example, by selecting a lower end cut point temperature of at least about 300°F (149°C).

[0082] In aspects where an interstage separator is also used to make a distillate fuel fraction, the portion boiling below the distillate fuel fraction includes naphtha boiling range molecules, light ends, and contaminants such as H2S. These different products can be separated from one another in any convenient manner. Similarly, if desired, one or more distillate fuel fractions can be formed from the distillate boiling range fraction. The portion boiling above the distillate fuel range represents potential lubricant base stock. In these aspects, the portion boiling above the distillate fuel range is subjected to additional hydroprocessing in the second hydroprocessing stage.

[0083] The hydrocracking process under low sulfur conditions can be conducted under similar conditions as those used for the sour hydrocracking process, or the conditions can be different. In one embodiment, the conditions of the low sulfur hydrocracking stage can be milder than the hydrocracking process of the sour stage. Suitable hydrocracking conditions for the non-sour stage can include, but are not limited to, conditions similar to the first stage or the sour stage. Suitable hydrocracking conditions can include a temperature of about 500°F (260°C) to about 840°F (449°C), a hydrogen partial pressure of about 1500 psig to about 5000 psig (10.3 MPag to 34.6 MPag), a liquid hourly space velocity of 0.05 h -1 to 10 h -1 and a hydrogen treat gas rate of 35.6 m 3 / m 3 to 1781 m 3 / m 3 (200 SCF / B to 10,000 SCF / B). In other embodiments, the conditions can include a temperature in the range of about 600°F (343°C) to about 815°F (435°C), a hydrogen partial pressure of about 1500 psig to about 3000 psig (10.3 MPag to 20.9 MPag), and a hydrogen treat gas rate of about 213 m3 / m 3 to about 1068 m 3 / m 3 (1200 SCF / B to 6000 SCF / B). The LHSV can be about 0.25 h -1 to about 50 h -1 or about 0.5 h -1 to about 20 h -1 , for example about 1.0 h -1 to about 4.0 h -1 .

[0084] In yet another aspect, the same conditions can be used for the hydrotreating and hydrocracking beds or stages, for example both use hydrotreating conditions or both use hydrocracking conditions. In yet another embodiment, the pressure of the hydrotreating and hydrocracking beds or stages can be the same.

[0085] In yet another aspect, the hydroprocessing reaction system can include more than one hydrocracking stage. If there are multiple hydrocracking stages, at least one of the hydrocracking stages can have effective hydrocracking conditions as described above, including a hydrogen partial pressure of at least about 1500 psig (10.3 MPag). In such an aspect, the other hydrocracking processes can be conducted under conditions that can include a lower hydrogen partial pressure. Suitable hydrocracking conditions for the additional hydrocracking stages can include, but are not limited to, a temperature of about 500 °F (260 °C) to about 840 °F (449 °C), a hydrogen partial pressure of about 250 psig to about 5000 psig (1.8 MPag to 34.6 MPag), a liquid hourly space velocity of 0.05 h -1 to 10 h -1 and a hydrogen treat gas rate of 35.6 m 3 / m 3 to 1781 m 3 / m 3 (200 SCF / B to 10,000 SCF / B). In other embodiments, the conditions for the additional hydrocracking stages can include a temperature ranging from about 600 °F (343 °C) to about 815 °F (435 °C), a hydrogen partial pressure of about 500 psig to about 3000 psig (3.5 MPag to 20.9 MPag), and a hydrogen treat gas rate of about 213 m 3 / m 3 to about 1068 m 3 / m 3 (1200 SCF / B to 6000 SCF / B). The LHSV can be about 0.25 h -1 to about 50 h -1 or about 0.5 h -1 to about 20 h -1, for example, about 1.0 h -1 to about 4.0 h -1 .

[0086] Additional hydrogenation operations - catalytic dewaxing, hydrofinishing and optional hydrocracking

[0087] In some alternative aspects, at least a lubricant boiling range portion of the hydroprocessed deasphalted oil can be contacted with additional hydroprocessing, including catalytic dewaxing, to form Group I and / or Group II base stocks, including Group I and / or Group II bright stock. In some aspects, a first lubricant boiling range portion of the hydroprocessed deasphalted oil can be solvent dewaxed as described above, while a second lubricant boiling range portion can be contacted with additional hydroprocessing. In other aspects, only solvent dewaxing or only additional hydroprocessing can be used to treat the lubricant boiling range portion of the hydroprocessed deasphalted oil.

[0088] In some embodiments, the additional hydroprocessing of the lubricant boiling range portion of the hydroprocessed deasphalted oil can further comprise contacting hydrocracking conditions before and / or after contacting catalytic dewaxing conditions. At this point in the process, the hydrocracking can be considered "low sulfur" hydrocracking because the sulfur content of the hydroprocessed deasphalted oil can be 200 wppm or less.

[0089] Suitable hydrocracking conditions can include contacting the feed with a hydrocracking catalyst as previously described. In some embodiments, it is preferred to use a USY zeolite having a silica to alumina ratio of at least 30 and a unit cell size of less than 24.32 Angstroms as the zeolite of the hydrocracking catalyst to improve the VI boost of the hydrocracking and / or to improve the ratio of distillate fuel yield to naphtha fuel yield in the fuel boiling range products.

[0090] Suitable hydrocracking conditions can also include a temperature of about 500°F (260°C) to about 840°F (449°C), a hydrogen partial pressure of about 1500 psig to about 5000 psig (10.3 MPag to 34.6 MPag), a liquid hourly space velocity of 0.05 h -1 to 10 h -1 , and a hydrogen treat gas rate of 35.6 m 3 / m 3 to 1781 m 3 / m 3 (200 SCF / B to 10,000 SCF / B). In other embodiments, the conditions can include a temperature ranging from about 600°F (343°C) to about 815°F (435°C), a hydrogen partial pressure of about 1500 psig to about 3000 psig (10.3 MPag to 20.9 MPag), and a liquid hourly space velocity of about 213 m 3 / m 3 to about 1068 m 3 / m3 (1200 SCF / B to 6000 SCF / B) hydrogen treat gas rate. The LHSV can be about 0.25 h -1 to about 50 h -1 or about 0.5 h -1 to about 20 h -1 for example about 1.0 h -1 to about 4.0 h -1 .

[0091] For catalytic dewaxing, a suitable dewaxing catalyst can comprise a molecular sieve, such as a crystalline aluminosilicate (zeolite). In one embodiment, the molecular sieve can comprise, or consist essentially of, or be ZSM-22, ZSM-23, ZSM-48. In some embodiments, a molecular sieve that is selective for dewaxing (rather than cracking) by isomerization can be used, such as ZSM-48, ZSM-23, or combinations thereof. Additionally or alternatively, the molecular sieve can comprise, or consist essentially of, or be a 10-member ring 1-D molecular sieve, such as EU-2, EU-11, ZBM-30, ZSM-48, or ZSM-23. In some embodiments, ZSM-48 is used. Note that a zeolite having the structure of ZSM-23 and a silica to alumina ratio of about 20: 1 to about 40: 1 can sometimes be referred to as SSZ-32. In some embodiments, the dewaxing catalyst can comprise a binder for the molecular sieve, such as alumina, titania, silica, silica-alumina, zirconia, or combinations thereof, such as alumina and / or titania or silica and / or zirconia and / or titania.

[0092] In some embodiments, the dewaxing catalyst used in the process according to the present application is a catalyst having a low silica to alumina ratio. For example, for ZSM-48, the silica to alumina ratio in the zeolite can be about 100: 1 or less, such as about 90: 1 or less or about 75: 1 or less or about 70: 1 or less. Additionally or alternatively, the silica to alumina ratio in the ZSM-48 can be at least about 50: 1, such as at least about 60: 1 or at least about 65: 1.

[0093] In various embodiments, the catalyst according to the present application further comprises a metal hydrogenation component. The metal hydrogenation component is typically a Group VI and / or Group VIII metal. In some embodiments, the metal hydrogenation component can be a combination of a non-noble Group VIII metal and a Group VI metal. Suitable combinations can include Ni, Co, or Fe with Mo or W, such as Ni with Mo or W.

[0094] The metal hydrogenation component can be added to the catalyst in any convenient manner. One technique for adding the metal hydrogenation component is incipient wetness. For example, after combining the zeolite and binder, the combined zeolite and binder can be extruded into catalyst particles. These catalyst particles can then be contacted with a solution containing a suitable metal precursor. Alternatively, the metal can be added to the catalyst by ion exchange, where the metal precursor is added to the mixture of zeolite (or zeolite and binder) prior to extrusion.

[0095] The amount of metal in the catalyst can be at least 0.1 wt% or at least 0.5 wt% or at least 1.0 wt% or at least 2.5 wt% or at least 5.0 wt%, based on the catalyst. The amount of metal in the catalyst can be 20 wt% or less or 10 wt% or less or 5 wt% or less or 2.5 wt% or less or 1 wt% or less, based on the catalyst. For embodiments where the metal is a combination of a non-noble Group VIII metal and a Group VI metal, the total amount of metal can be 0.5 wt% to 20 wt% or 1 wt% to 15 wt% or 2.5 wt% to 10 wt%.

[0096] The dewaxing catalysts useful in the processes according to the present application can also include a binder. In some embodiments, the dewaxing catalysts used in the processes according to the present application are formulated using a low surface area binder, which represents a binder having a surface area of 100 m 2 / g or less or 80 m 2 / g or less or 70 m 2 / g or less. Additionally or alternatively, the binder can have a surface area of at least about 25 m 2 / g. The amount of zeolite in the catalyst formulated using a binder can be about 30 wt% zeolite to 90 wt% zeolite, relative to the total weight of the binder and zeolite. In some embodiments, the amount of zeolite is at least about 50 wt%, for example at least about 60 wt% or about 65 wt% to about 80 wt%, of the total weight of the zeolite and binder.

[0097] Without being bound by any particular theory, it is believed that the use of a low surface area binder reduces the amount of the surface area of the binder available to load hydrogenation metal on the catalyst. This results in an increase in the amount of hydrogenation metal loaded within the pores of the molecular sieve in the catalyst.

[0098] The zeolite can be combined with the binder in any convenient manner. For example, the bound catalyst can be made by starting with powders of both the zeolite and the binder, combining the powders with added water and grinding to form a mixture, and then extruding the mixture to make the bound catalyst of the desired size. An extrusion aid can also be used to modify the extrusion flow properties of the zeolite and binder mixture. The amount of skeletal alumina in the catalyst can range from 0.1 to 3.33 wt% or 0.1 to 2.7 wt% or 0.2 to 2 wt% or 0.3 to 1 wt%.

[0099] Effective conditions for catalytically dewaxing the feedstock in the presence of the dewaxing catalyst can include a temperature of 280°C to 450°C, such as 343°C to 435°C; a hydrogen partial pressure of 3.5 MPag to 34.6 MPag (500 psig to 5000 psig), such as 4.8 MPag to 20.8 MPag; and a hydrogen circulation rate of 178 m 3 / m 3 (1000 SCF / B) to 1781 m 3 / m 3 (10,000 SCF / B), such as 213 m 3 / m 3 (1200 SCF / B) to 1068 m 3 / m 3 (6000 SCF / B). The LHSV can be about 0.2 h -1 to about 10 h -1 , such as about 0.5 h -1 to about 5 h -1 and / or about 1 h -1 to about 4 h -1 .

[0100] Prior to and / or after catalytic dewaxing, the deasphalted oil (i.e., at least the lubricant boiling range portion thereof) of the hydroprocessing operation can be contacted with an aromatic saturation catalyst, which can alternatively be referred to as a hydrofinishing catalyst. Contacting with the aromatic saturation catalyst can occur prior to or after fractionation. If aromatic saturation occurs after fractionation, one or more of the fractionation products can be subjected to aromatic saturation. Alternatively, the entire effluent from the last hydrocracking or dewaxing process can be hydrofinished and / or subjected to aromatic saturation.

[0101] The hydrofmishing and / or aromatic saturation catalysts can comprise catalysts comprising Group VI metals, Group VIII metals, and mixtures thereof. In one embodiment, exemplary metals include at least one metal sulfide having strong hydrogenation function. In another embodiment, the hydrofmishing catalysts can comprise Group VIII noble metals such as Pt, Pd, or combinations thereof. Mixtures of metals can also be present as bulk metal catalysts, where the amount of metal is about 30 wt% or more based on the catalyst. For supported hydroprocessing catalysts, suitable metal oxide supports include low-acid oxides such as silica, alumina, silica-alumina, or titania, for example alumina. Exemplary hydrofmishing catalysts for aromatic saturation will comprise at least one metal having relatively strong hydrogenation function on a porous support material. Typical support materials include amorphous or crystalline oxide materials such as alumina, silica, and silica-alumina. The support material can also be modified, for example, by halogenation or, in particular, fluorination. For non-noble metals, the metal content of the catalyst is typically up to about 20 wt%. In one embodiment, the hydrofmishing catalysts can comprise crystalline materials belonging to the M41S class or series of catalysts. The M41S series of catalysts are mesoporous materials with high silica content. Examples include MCM-41, MCM-48, and MCM-50. An exemplary member of this class is MCM-41.

[0102] The hydrofmishing conditions can include a temperature of about 125°C to about 425°C, for example about 180°C to about 280°C; a hydrogen partial pressure of about 500 psig (3.4 MPa) to about 3000 psig (20.7 MPa), for example about 1500 psig (10.3 MPa) to about 2500 psig (17.2 MPa); and a liquid hourly space velocity of about 0.1 hr -1 to about 5 hr -1 LHSV, for example about 0.5 hr -1 to about 1.5 hr -1 The hydrogen treat gas rate can be about 35.6 m 3 / m 3 to about 1781 m 3 / m 3 (200 SCF / B to 10,000 SCF / B).

[0103] Solvent treatment of catalytic dewaxing effluent or catalytic dewaxing input stream

[0104] For deasphalted oil from propane deasphalting, additional hydroprocessing, including catalytic dewaxing, can be sufficient to form a lubricant base stock having low haze formation and unexpected compositional properties. For deasphalted oil from C 4+The deasphalted deasphalted oil, after the additional hydroprocessing including catalytic dewaxing, can be solvent treated to form one or more lubricant base stock products having reduced or eliminated tendency to form haze. The type of solvent treatment can depend on the nature of the initial hydroprocessing (hydrotreating and / or hydrocracking) and the nature of the additional hydroprocessing including dewaxing.

[0105] In aspects where the initial hydroprocessing is less severe, corresponding to 10 wt% to 40 wt% conversion relative to about 700°F (370°C), the subsequent solvent treatment can correspond to solvent dewaxing. Solvent dewaxing can be carried out in a manner similar to the solvent dewaxing described above. However, such solvent dewaxing can be used to make Group II lubricant base stocks. In some aspects, when the initial hydroprocessing corresponds to 10 wt% to 40 wt% conversion relative to 370°C, the catalytic dewaxing during the additional hydroprocessing can also be carried out at lower severity, such that at least 6 wt%, or at least 8 wt%, or at least 10 wt%, or at least 12 wt%, or at least 15 wt%, for example up to 20 wt%, of the wax remains in the catalytic dewaxed effluent. The solvent dewaxing can then be used to reduce the wax content in the catalytic dewaxed effluent by 2 wt% to 10 wt%. This can make a solvent dewaxed oil product having a wax content of 0.1 wt% to 12 wt%, or 0.1 wt% to 10 wt%, or 0.1 wt% to 8 wt%, or 0.1 wt% to 6 wt%, or 1 wt% to 12 wt%, or 1 wt% to 10 wt%, or 1 wt% to 8 wt%, or 4 wt% to 12 wt%, or 4 wt% to 10 wt%, or 4 wt% to 8 wt%, or 6 wt% to 12 wt%, or 6 wt% to 10 wt%. In particular, the solvent dewaxed oil can have a wax content of 0.1 wt% to 12 wt%, or 0.1 wt% to 6 wt%, or 1 wt% to 10 wt%, or 4 wt% to 12 wt%.

[0106] In various aspects, the subsequent solvent treatment can correspond to solvent extraction. Solvent extraction can be used to reduce the aromatic content and / or the amount of polar molecules. The solvent extraction process selectively dissolves the aromatic compound components to form an extract phase rich in aromatic compounds, while leaving more of the paraffinic components in a raffinate phase lean in aromatic compounds. Naphthenes are distributed between the extract and raffinate phases. Typical solvents for solvent extraction include phenol, furfural, and N-methyl pyrrolidone. By controlling the solvent to oil ratio, the extraction temperature, and the method in which the distillate to be extracted is contacted with the solvent, the degree of separation between the extract and raffinate phases can be controlled. Any convenient type of liquid-liquid extractor can be used, such as a countercurrent liquid-liquid extractor. Depending on the initial concentration of aromatic compounds in the deasphalted oil, the raffinate phase can have an aromatic content of 5 wt% to 25 wt% and / or a saturated compound content of 75 wt% to 95 wt% (or more). For a typical feed, the aromatic content can be at least 10 wt% and / or the saturated compound content can be 90 wt% or less. In various aspects, the raffinate yield from solvent extraction can be at least 40 wt%, or at least 50 wt%, or at least 60 wt%, or at least 70 wt%.

[0107] In some embodiments, the raffinate from solvent extraction can be under-extracted. In these aspects, the extraction is performed in a manner that maximizes the raffinate yield while still removing a substantial portion of the lowest quality molecules from the feed. By controlling the extraction conditions, such as by reducing the solvent to oil treatment ratio and / or reducing the extraction temperature, the raffinate yield can be maximized.

[0108] The solvent treated oil (solvent dewaxed or solvent extracted) can have a pour point of -6°C or lower or -10°C or lower or -15°C or lower or -20°C or lower, depending on the nature of the target lubricant base stock product. Additionally or alternatively, the solvent treated oil (solvent dewaxed or solvent extracted) can have a cloud point of -2°C or lower or -5°C or lower or -10°C or lower, depending on the nature of the target lubricant base stock product. The pour point and cloud point can be determined according to ASTM D97 and ASTM D2500, respectively. The resulting solvent treated oil can be suitable for forming one or more Group II base stocks. The resulting solvent dewaxed oil can have a viscosity index of at least 80 or at least 90 or at least 95 or at least 100 or at least 110 or at least 120. The viscosity index can be determined according to ASTM D2270. In some embodiments, at least 10 wt% (or at least 20 wt% or at least 30 wt%) of the resulting solvent treated oil can correspond to a Group II bright stock having a kinematic viscosity at 100°C of at least 14 cSt or at least 15 cSt or at least 20 cSt or at least 25 cSt or at least 30 cSt or at least 32 cSt, for example, up to 50 cSt or more. Additionally or alternatively, the Group II bright stock can have a kinematic viscosity at 40°C of at least 300 cSt or at least 320 cSt or at least 340 cSt or at least 350 cSt, for example, up to 500 cSt or more. The kinematic viscosity can be determined according to ASTM D445. Additionally or alternatively, the Conradson carbon content can be about 0.1 wt% or lower or about 0.02 wt% or lower. The Conradson carbon content can be determined according to ASTM D4530. Additionally or alternatively, the resulting base stock can have a haze of at least 1.5 (in combination with a cloud point below 0°C), or can have a haze of at least 2.0 and / or can have a haze of 4.0 or lower or 3.5 or lower or 3.0 or lower. In particular, the haze can be 1.5 to 4.0 or 1.5 to 3.0 or 2.0 to 4.0 or 2.0 to 3.5.

[0109] By reducing or minimizing the difference between the cloud point temperature and the pour point temperature of the lubricant base stock, the tendency of the lubricant base stock formed from the solvent treated oil to form haze can be reduced or eliminated. In various aspects, the difference between the cloud point and the pour point of the resulting solvent dewaxed oil and / or one or more Group II lubricant base stocks (including one or more bright stocks formed from the solvent treated oil) can be 22°C or lower or 20°C or lower or 15°C or lower or 10°C or lower, for example, a difference as low as about 1°C.

[0110] In some alternative aspects, the above solvent treatment can be performed prior to catalytic dewaxing.

[0111] Group II base stock product

[0112] For deasphalted oils derived from propane, butane, pentane, hexane, and higher alkanes or mixtures thereof, additional hydrotreating operations (including catalytic dewaxing) and potential solvent treatments can be sufficient to produce lubricant base oils with low (or no) haze formation and improved compositional properties. Currently manufactured conventional products with a kinematic viscosity of approximately 32 cSt at 100°C contain more than 10% by weight of aromatic compounds and / or more than 0.03% by weight of sulfur compared to the base oil.

[0113] In various aspects, the base oils produced according to the method of the present invention can have a kinematic viscosity of at least 14 cSt, at least 20 cSt, at least 25 cSt, at least 30 cSt, or at least 32 cSt at 100°C and can contain less than 10% by weight of aromatic compounds, more than 90% by weight of saturated compounds, and less than 0.03% by weight of sulfur. In some embodiments, the content of saturated compounds can be much higher, for example, more than 95% by weight or more than 97% by weight. Furthermore, detailed characterization of the "branching" (branching) of the molecules by C-NMR reveals a high degree of branching, which can be quantified by examining the absolute number of methyl branches, ethyl branches, or propyl branches, or combinations thereof, respectively. Branching can also be quantified by observing the ratio of branching points (methyl, ethyl, or propyl) to the number of internal carbons labeled as ε-carbons by C-NMR. Quantification of branching by ε-carbons can be used to determine whether the base oil will stabilize over time to prevent haze formation. For the purposes reported herein... 13 C-NMR results show that the sample can be prepared into a solution of 25 to 30 wt% acetylacetone chromium(III) in CDCl3 with 7% added as a relaxant. The analysis was performed on a JEOL ECS NMR spectrometer with a proton resonance frequency of 400 MHz. 13 ¹³C NMR experiments. Quantitative analysis was performed at 27°C using an inversely gated decoupling experiment with a 45° flip angle, 6.6 seconds between pulses, 64K data points, and 2400 scans. 13 C10 NMR experiments. Spectral reference was taken at 0 ppm using TMS. Spectra were processed with line broadening from 0.2 to 1 Hz and baseline correction was applied before manual integration. The entire spectrum was integrated to determine the mole percentage in different integration regions as follows: 170 to 190 PPM (aromatic C); 30 to 29.5 PPM (ε-carbon); 15 to 14.5 PPM (terminal and side-chain propyl groups); 14.5 to 14 PPM - terminal methyl (α-) of long chains; 12 to 10 PPM (side-chain and terminal ethyl groups). Total methyl content could be obtained by proton NMR. The methyl signal at 0 to 1.1 PPM could be integrated. The entire spectrum could be integrated to determine the mole percentage of methyl. The mole percentage of methyl could be converted to total methyl using the average carbon number obtained from gas chromatography.

[0114] It has also been found that using Fourier Transform Ion Cyclotron Resonance-Mass Spectrometry (FTICR-MS) and / or Field Desorption Mass Spectrometry (FDMS), the prevalence of smaller naphthenic ring structures of less than 6 or less than 7 or less than 8 rings can be similar, but the remaining number of larger naphthenic ring structures of 7 or more rings or 8+ rings or 9+ rings or 10+ rings is reduced in base stocks that are stable against haze formation.

[0115] For the FTICR-MS results reported herein, the results were generated according to the methods described in U.S. Patent No. 9,418,828. The methods described in U.S. Patent No. 9,418,828 generally involve the use of laser desorption with Ag ion complexation (LDI-Ag) to ionize petroleum saturates molecules, including 538°C+ molecules, without destroying the molecular ion structure. An ultra-high resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometer is applied to determine the precise elemental formula of the saturated compound-Ag cation and the corresponding abundance. The saturated compound fraction composition can be arranged by homologous series and molecular weight. U.S. Patent No. 9,418,828 is incorporated herein by reference in part for the determination of saturate ring structure content in a sample.

[0116] For the FDMS results reported herein, Field Desorption (FD) is a soft ionization method in which a high-potential electric field is applied to an emitter (a fine wire that has been formed into tiny “whiskers”) that has been coated with a dilute sample, causing gaseous molecules of the analyte to ionize. The mass spectrum produced by FD consists of molecular radical cations M + or in some cases protonated molecular ions [M + H] + prevail. Because FDMS cannot distinguish between molecules with “n” naphthenic rings and molecules with “n+7” rings, the FDMS data is “corrected” by using FTICR-MS data from the most similar sample. FDMS correction is performed by applying the resolved “n” to “n+7” ring ratio from FTICR-MS to the unresolved FDMS data for that particular class of molecules.

[0117] It has further been found that base oils of the above composition provide the advantage of being haze-free at the start of manufacture and remaining haze-free over long periods of time. This is an advantage over prior art high saturate heavy base stocks.

[0118] Additionally, it has been found that the base stocks of the present application are capable of being blended with additives to form formulated lubricants such as, but not limited to, marine oils, engine oils, greases, paper machine oils, and gear oils. These additives can include, but are not limited to, detergents, dispersants, antioxidants, viscosity modifiers, and pour point depressants. When so blended, the performance as measured by standard low temperature tests such as Mini Rotary Viscometer (MRV) and Brookfield testing has been shown to be superior to formulations blended with conventional base stocks.

[0119] It has also been found that when common additives such as, but not limited to, antifoam agents, pour point depressants, antioxidants, rust inhibitors are blended into industrial oils, the oxidation performance has been shown to be superior to that of conventional base stocks in standard oxidation tests such as the American Iron and Steel Oxidation Test.

[0120] Other performance parameters such as interfacial properties, deposit control, storage stability, and toxicity have also been examined and are similar to or better than conventional base stocks.

[0121] In addition to being blended with additives, the base stocks of the present application can be blended with other base stocks to make base oils. These other base stocks can include solvent treated base stocks, hydroprocessed base stocks, synthetic base stocks, base stocks derived from the Fisher-Tropsch process, PAOs, and naphthenic base stocks. Additionally or alternatively, the other base stocks can include Group I base stocks, Group II base stocks, Group III base stocks, Group IV base stocks, and / or Group V base stocks. Additionally or alternatively, one or more low viscosity base stocks can be combined with the high viscosity base stocks of the present application to produce an extreme bimodal blend. In some embodiments, the low viscosity base stock can be any one or more of the following: a light neutral base stock, a medium neutral base stock, a heavy neutral base stock, a Group I base stock, a Group II base stock, a Group III base stock, a Group IV base stock, a Group V base stock, or any combination thereof. The low viscosity base stock can have a kinematic viscosity at 100°C of up to 2 cSt, up to 3 cSt, up to 4 cSt, up to 5 cSt, up to 6 cSt, up to 7 cSt, up to 8 cSt, up to 9 cSt, up to 10 cSt, up to 11 cSt, or up to 12 cSt. In some embodiments, the ratio of the amount of the low viscosity base stock relative to the amount of the high viscosity base stock of the present application can be up to 1 :99, up to 5:95, up to 10:90, up to 20:80, up to 30:70, up to 40:60, up to 50:50, up to 60:40, up to 70:30, up to 80:20, up to 90:10, up to 95:5, or up to 99:1.

[0122] Additionally or alternatively, other types of base stocks for blending can also include hydrocarbon-based aromatic compounds, alkylated aromatic compounds, esters (including synthetic esters and / or renewable esters), and / or other unconventional or non-conventional base stocks. These base oil blends of the base stocks of the present application and other base stocks can also be combined with additives such as those mentioned herein to make formulated lubricants.

[0123] The formulated fluids of the present application can include one or more performance additives including, but not limited to, anti-wear additives, detergents, dispersants, viscosity modifiers, corrosion inhibitors, rust inhibitors, metal deactivators, extreme pressure additives, anti-seizure additives, wax modifiers, viscosity index improvers, fluid loss additives, seal compatibility additives, friction modifiers, lubricity additives, stain control additives, colorants, defoamers, demulsifiers, emulsifiers, densifiers, wetting agents, gelling agents, tackiness agents, colorants, and the like. Such additives are typically delivered with varying amounts of diluent oil, which can range from 5 percent by weight (wt.%) to 50 wt.%.

[0124] The additives useful in the fluids of the present application need not be soluble in the fluid. Insoluble additives such as zinc stearate in oil can be dispersed in the fluids of the present application as a suspension.

[0125] Further, it has been found that the base stocks of the present application can be used as thickening agents in formulated fluids to achieve a desired viscosity. The base stocks of the present application can be used as thickening agents in combination with other thickening agents. The base stocks of the present application can be used as thickening agents in place of other thickening agents. The use of the base stocks of the present application as thickening agents can reduce or eliminate the use of other thickening agents. For example, the amount of another thickening agent in a formulated fluid can be reduced by up to 0.1%, up to 1%, up to 5%, up to 10%, up to 20%, up to 30%, up to 40%, up to 50%, up to 60%, up to 70%, up to 80%, up to 90%, up to 95%, or up to 100%.

[0126] The formulated fluids containing the base stocks of the present application as thickening agents can exhibit similar viscosity properties as equivalent formulated fluids having one or more other thickening agents but not containing the base stocks of the present application. The formulated fluids containing the base stocks of the present application as thickening agents can exhibit enhanced performance (e.g., oxidation resistance, low temperature flow, and / or deposit control) compared to equivalent formulated fluids having one or more other thickening agents but not containing the base stocks of the present application. The formulated fluids containing the base stocks of the present application as thickening agents can be blended at a lower cost compared to equivalent formulated fluids having one or more other thickening agents but not containing the base stocks of the present application.

[0127] Examples of other thickening agents include viscosity index improvers and other high viscosity base stocks. An exemplary viscosity index improver is a polyisobutylene polymer, which can be used to thicken a formulated fluid to achieve a desired lubricant viscosity. Polyisobutylene can be present in a formulated fluid at a treat rate of 1 wt% to 20 wt%. The use of polyisobutylene can be reduced or eliminated by using the base stocks of the present application.

[0128] Further, by using the base stocks of the present application, the use of other high viscosity base stocks in a formulated fluid can be reduced or eliminated. Exemplary high viscosity base stocks include Group I bright stock and high viscosity PAO. By using the base stocks of the present application in a formulated fluid, the amount of another high viscosity base stock in the formulated fluid can be reduced by up to 0.1%, up to 1%, up to 5%, up to 10%, up to 20%, up to 30%, up to 40%, up to 50%, up to 60%, up to 70%, up to 80%, up to 90%, up to 95%, or up to 100%.

[0129] In some fluid formulations, multiple PAO components can be present, and the base stocks of the present application can reduce or replace a single PAO component, leaving other PAO components in the formulated fluid. In other embodiments, the base stocks of the present application can partially or completely replace multiple PAO components, and still leave other PAO components in the formulated lubricant.

[0130] The type and amount of performance additives used in combination with the present application in a lubricant composition is not limited by the examples shown herein.

[0131] Other additives - detergents

[0132] Exemplary detergents useful in the present application include, for example, an alkali metal detergent, an alkaline earth metal detergent, or a mixture of one or more alkali metal detergents and one or more alkaline earth metal detergents. A typical detergent is an anionic material comprising a long chain hydrophobic portion of the molecule and a smaller anionic or oleophobic hydrophilic portion of the molecule. The anionic portion of the detergent is typically derived from an organic acid such as sulfuric acid, carboxylic acid, phosphorous acid, phenol, or mixtures thereof. The counterion is typically an alkaline earth metal or an alkali metal.

[0133] Salts containing substantially stoichiometric amounts of metal are described as neutral salts and have a total base number (TBN, measured according to ASTM D2896) from 0 to 80. Many compositions are overbased, containing a large excess of metal resulting from the reaction of an excess of a metal compound (e.g., metal hydroxide or oxide) with an acidic gas (e.g., carbon dioxide). Useful detergents can be neutral, lightly overbased, or highly overbased. These detergents can be used in neutral, overbased, highly overbased calcium salicylates, sulfonates, phenates, and / or mixtures of magnesium salicylates, sulfonates, phenates. The TBN range can vary from low, medium, to high TBN products, including as low as 0 to as high as 600. Mixtures of low, medium, high TBN can be used, as well as mixtures of calcium and magnesium metal type detergents, and including sulfonates, phenates, salicylates, and carboxylates. Detergent mixtures can be used with a metal ratio of 1, as well as a detergent to metal ratio of 2, and a detergent to metal ratio as high as 5. Borated detergents can also be used.

[0134] Alkaline earth metal phenates are another class of useful detergents. These detergents can be prepared by reacting an alkaline earth metal hydroxide or oxide (e.g., CaO, Ca(OH)2, BaO, Ba(OH)2, MgO, Mg(OH)2) with an alkyl phenol or a sulfurized alkyl phenol. Useful alkyl groups include linear or branched C1-C 30 alkyl groups, such as C4-C 20 or mixtures thereof. Examples of suitable phenols include isobutyl phenol, 2- ethylhexyl phenol, nonyl phenol, dodecyl phenol, and the like. It is noted that the starting alkyl phenol can contain more than one alkyl substituent, each independently linear or branched, and can be used in an amount of 0.5 to 6 weight percent. When an un-sulfurized alkyl phenol is used, the sulfurized product can be obtained by methods well known in the art. These methods include heating a mixture of the alkyl phenol and a sulfurizing agent (including elemental sulfur, sulfur halides such as sulfur dichloride, and the like); then reacting the sulfurized phenol with an alkaline earth metal base.

[0135] Metal salts of carboxylic acids can also be used as detergents. These carboxylic acid detergents can be prepared by reacting a basic metal compound with at least one carboxylic acid and removing free water from the reaction product. These compounds can be overbased to produce the desired TBN level. Detergents made from salicylic acid are one class of detergents from carboxylic acids. Useful salicylates include long chain alkyl salicylates. One useful composition series has the formula

[0136]

[0137] where R is an alkyl group having 1 to 30 carbon atoms, n is an integer from 1 to 4, and M is an alkaline earth metal. Example R groups include at least C 11 , such as C4-C13 or more alkyl chains. R can be substituted with substituents that do not affect the function of the detergent. M can be calcium, magnesium, or barium. In some embodiments, M is calcium.

[0138] Hydrocarbyl-substituted salicylic acids can be prepared from phenol by the Kolbe reaction (see U.S. Patent No. 3,595,791). Metal salts of hydrocarbyl-substituted salicylic acids can be prepared by metathesis of the metal salt in a polar solvent such as water or an alcohol.

[0139] Alkaline earth metal phosphates are also used as detergents and are known in the art.

[0140] Detergents can be simple detergents or so-called blended or complex detergents. The latter detergents are capable of providing the properties of two detergents without the need to blend separate materials. See U.S. Patent No. 6,034,039.

[0141] Examples of detergents include calcium phenate, calcium sulfonate, calcium salicylate, magnesium phenate, magnesium sulfonate, magnesium salicylate, and other related components including boric acidized detergents, and mixtures thereof. An example mixture of detergents can include magnesium sulfonate and calcium salicylate, magnesium sulfonate and calcium sulfonate, magnesium sulfonate and calcium phenate, calcium phenate and calcium salicylate, calcium phenate and calcium sulfonate, calcium phenate and magnesium salicylate, calcium phenate and magnesium phenate.

[0142] Another series of detergents are oil-soluble ashless non-ionic detergents. Typical non-ionic detergents are polyoxyethylene, polyoxypropylene, polyoxybutylene alkyl ethers, or nonylphenol ethoxylates. For reference, see "Nonionic Surfactants: Physical Chemistry," Martin J. Schick, CRC Press; 2nd edition (March 27, 1987). These detergents are less common in engine lubricant formulations, but have many advantages, such as improved solubility in ester base stocks. Non-ionic detergents that are soluble in hydrocarbons typically have a hydrophilic-lipophilic balance (HLB) value of 10 or less.

[0143] To minimize the effects of ash deposits on engine knock and pre-ignition, including low speed pre-ignition, the detergent can be an ashless non-ionic detergent having a hydrophilic-lipophilic balance (HLB) value of 10 or less. These detergents are commercially available from, for example, Croda Inc. under the trade names "Alarmol PS11E" and "Alarmol PS15E"; and from, for example, Dow Chemical Co. under the trade names "Ecosurf EH-3", "Tergitol 15-S-3", "Tergitol L-61", "Tergitol L-62", "Tergitol NP-4", "Tergitol NP-6", "Tergitol NP-7", "Tergitol NP-8", "Tergitol NP-9", "Triton X-15", and "Triton X-35".

[0144] The concentration of the detergent in the lubricating oil of the present application can range from 0.5 to 6.0 wt.%, for example, 0.6 to 5.0 wt.% or 0.8 wt.% to 4.0 wt.%, based on the total weight of the lubricating oil.

[0145] Other additives - dispersants

[0146] During engine operation, insoluble oxidation by-products are produced. Dispersants help to keep these by-products in solution, thereby reducing their deposition on metal surfaces. The dispersants used in lubricating oil formulations can be ashless or ash-forming in nature. In some embodiments, the dispersants are ashless. So-called ashless dispersants are organic materials that do not form ash substantially upon combustion. For example, dispersants containing non-metals or boronated metals are considered to be ashless. In contrast, the metal-containing detergents discussed above form ash upon combustion.

[0147] Suitable dispersants typically contain a polar group attached to a relatively high molecular weight hydrocarbon chain. The polar group typically contains at least one element of nitrogen, oxygen, or phosphorus. Typical hydrocarbon chains contain 50 to 400 carbon atoms.

[0148] One particularly useful class of dispersants is the alkenyl succinic acid derivatives, which are typically prepared by the reaction of a long chain hydrocarbyl substituted succinic compound (typically a hydrocarbyl substituted succinic anhydride) with a polyhydroxy or polyamino compound. The long chain hydrocarbyl group, which makes up the lipophilic portion of the molecule that imparts solubility in oil, is typically a polyisobutenyl group.

[0149] Hydrocarbyl-substituted succinic acid and hydrocarbyl-substituted succinic anhydride derivatives are useful dispersants. In particular, succinimides, succinates, or succinate amides prepared by reacting a hydrocarbyl-substituted succinic acid compound having at least 50 carbon atoms in the hydrocarbyl substituent with at least one equivalent of an alkylene amine are particularly useful, although sometimes a hydrocarbyl substituent having from 20 to 50 carbon atoms can be useful.

[0150] Succinimides are formed by condensation reactions between a hydrocarbyl-substituted succinic anhydride and an amine. The molar ratio can vary depending on the polyamine. For example, the molar ratio of hydrocarbyl-substituted succinic anhydride to TEPA can vary from 1 : 1 to 5: 1.

[0151] Succinates are formed by condensation reactions between a hydrocarbyl-substituted succinic anhydride and an alcohol or polyol. The molar ratio can vary depending on the alcohol or polyol used. For example, condensation products of hydrocarbyl-substituted succinic anhydride and pentaerythritol are useful dispersants.

[0152] Succinate amides are formed by condensation reactions between a hydrocarbyl-substituted succinic anhydride and an alkanolamine. For example, suitable alkanolamines include ethoxylated polyalkyl polyamines, propoxylated polyalkyl polyamines, and polyalkenyl polyamines such as polyvinyl polyamines. One example is propoxylated hexamethylene diamine.

[0153] The molecular weight of the hydrocarbyl-substituted succinic anhydride used in the preceding paragraphs is generally in the range of between 800 and 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, boric acid esters, or highly borated dispersants to form borated dispersants having typically from 0.1 to 5 moles of boron per mole of dispersant reaction product.

[0154] Mannich base dispersants are prepared from the reaction of an alkyl phenol, formaldehyde, and an amine. See U.S. Patent No. 4,767,551. Processing aids and catalysts such as oleic acid and sulfonic acids can also be part of the reaction mixture. The molecular weight of the alkyl phenol ranges from 800 to 2,500.

[0155] Typical high molecular weight fatty acid modified Mannich condensation products useful in the present invention can be prepared from high molecular weight alkyl-substituted hydroxyaromatic compounds or reactants containing HNR2groups.

[0156] Example dispersants can include both borated and unborated succinimides, including succinimide derivatives derived from mono-succinimides, bis-succinimides, and / or mixtures of mono- and bis-succinimides, where the hydrocarbyl succinimide is derived from: a hydrocarbylene group, such as a polyisobutylene having an Mn of 500 to 5000 or 1000 to 3000 or 1000 to 2000; or a mixture of such hydrocarbylene groups, often with high terminal vinyl groups. Other dispersants include succinates and amides, alkylphenol-polyamine coupled Mannich adducts, their blocked derivatives, and other related components.

[0157] Poly methacrylate or polyacrylate derivatives are another class of dispersants. These dispersants are typically prepared by reacting a nitrogen-containing monomer with a methacrylate or acrylate ester containing 5 to 25 carbon atoms in the ester group. Representative examples are shown in U.S. Pat. Nos. 2,100,993 and 6,323,164. Poly methacrylate and polyacrylate dispersants are often used as multifunctional viscosity index improvers. Lower molecular weight versions can be used as lubricant dispersants or fuel detergents.

[0158] Among the polar esters of non-aromatic dicarboxylic acids, preferably adipates, poly methacrylate or polyacrylate dispersants can be preferred because many other conventional dispersants are less soluble. Dispersants for polyol esters in the present invention can include poly methacrylate and polyacrylate dispersants.

[0159] Such dispersants can be used in amounts of 0.1 to 20 wt%, such as 0.5 to 8 wt% or 0.5 to 4 wt%. The hydrocarbon number of the dispersant atoms can range from C 60 to C 1000 or C 70 to C 300 or C 70 to C 200 These dispersants can contain both neutral and basic nitrogen, as well as mixtures of the two. The dispersants can be blocked with borate and / or cyclic carbonate.

[0160] Still other potential dispersants can contain polyalkenyl groups, such as polyalkenyl groups having a molecular weight of at least 900 and an average of 1.3 to 1.7 functional groups per polyalkenyl moiety. Still other suitable polymers can include polymers formed by cationic polymerization of monomers such as isobutylene and / or styrene.

[0161] Other additives - anti-wear agents

[0162] Metal alkyl thiophosphates, and more particularly metal dialkyldithiophosphates or zinc dialkyldithiophosphates (ZDDP) in which the metal component is zinc, are useful components of the lubricating oils of the present application. The ZDDP can be derived from a primary alcohol, a secondary alcohol, or mixtures thereof. The ZDDP compounds generally have the formula:

[0163] Zn[SP(S)(OR 1 )(OR 2 )]2

[0164] wherein R 1 and R 2 are C1-C 18 alkyl groups, for example C2-C 12 alkyl groups. The alkyl groups can be straight or branched. The alcohol used in the ZDDP can be 2-propanol, butanol, sec-butanol, pentanol, hexanol such as 4-methyl-2-pentanol, n-hexanol, n-octanol, 2-ethylhexanol, alkylated phenols, and the like. Mixtures of secondary alcohols or mixtures of primary and secondary alcohols can be preferred. Alkylaryl groups can also be used.

[0165] Example zinc dithiophosphates that are commercially available include secondary zinc dithiophosphates such as those commercially 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".

[0166] The ZDDP is generally used in amounts of 0.4 to 1.2 weight percent, for example 0.5 to 1.0 weight percent, for example 0.6 to 0.8 weight percent, based on the total weight of the lubricating oil, although it can be used in amounts somewhat less or somewhat greater than this range, if desired. In some embodiments, the ZDDP is a secondary ZDDP and is present in an amount of 0.6 to 1.0 weight percent of the total weight of the lubricating oil.

[0167] More generally, other types of suitable anti-wear additives can include, for example, metal salts of carboxylic acids. The metal can be a transition metal or a mixture of transition metals, for example one or more metals derived from Group 10, 11, or 12 of the IUPAC Periodic Table. The carboxylic acid can be an aliphatic carboxylic acid, a cycloaliphatic carboxylic acid, an aromatic carboxylic acid, or mixtures thereof.

[0168] Low phosphorus engine oil formulations are included in the present application. For such formulations, the phosphorus content is generally less than 0.12 weight percent, for example less than 0.10 weight percent or less than 0.085 weight percent. Low phosphorus can be preferred in combination with friction modifiers.

[0169] Other additives - extreme pressure additives

[0170] Extreme pressure additives can be incorporated into the fluids of the present application. The extreme pressure additives can include organic sulfur compounds, organic phosphorus compounds, organic boron compounds, organic sulfur-phosphorus compounds, organic sulfur-phosphorus-boron compounds, organic chlorine compounds, or any combination thereof. Some examples of such organic compounds include esters, triglycerides, paraffins, and olefins. Suitable extreme pressure additives for use in the fluids of the present application include temperature dependent extreme pressure additives configured to react with metal surfaces under localized high temperature conditions that can exist in a machine where one component exerts sufficient pressure on another to cause boundary conditions of lubrication. Suitable extreme pressure additives for use in the fluids of the present application include non-temperature dependent extreme pressure additives. In some embodiments, the extreme pressure additives of the fluids of the present application can be present in an amount of about 0.1 wt% to about 30 wt% or about 0.1 wt% to about 25 wt% or about 0.1 wt% to about 20 wt%.

[0171] Other additives - viscosity index improvers

[0172] Viscosity index improvers (also known as VI improvers, viscosity modifiers, and viscosity improvers) can be included in the lubricant compositions of the present application. Viscosity index improvers provide high and low temperature operating properties to lubricants. These additives impart shear stability at high temperatures and acceptable viscosities at low temperatures.

[0173] Suitable viscosity index improvers include high molecular weight hydrocarbons, polyesters, and viscosity index improver dispersants that also function as dispersants. Typical molecular weights of these polymers are about 10,000 to 1,500,000, more typically about 20,000 to 1,200,000, and still more typically about 50,000 to 1,000,000. Typical molecular weights of polymethacrylate or polyacrylate viscosity index improvers are less than about 50,000.

[0174] Examples of suitable viscosity index improvers are linear or star-shaped polymers, and copolymers of methacrylate, butadiene, olefins, or alkylated styrene. Polyisobutylene is a commonly used viscosity index improver. Another suitable viscosity index improver is polymethacrylate (e.g., copolymers of various chain lengths of alkyl methacrylate), some formulations of which are also used as pour point depressants. Other suitable viscosity index improvers include copolymers of ethylene and propylene, hydrogenated block copolymers of styrene and isoprene, and polyacrylates (e.g., copolymers of various chain lengths of acrylate). Specific examples include styrene-isoprene or styrene-butadiene type polymers of 50,000 to 200,000 molecular weight.

[0175] The olefin copolymer was purchased from Chevron Oronite Company LLC, under the trade name [not specified]. (For example" 8921 and " 8941”); Afton Chemical Corporation, product name (For example" 5850B”; and The Lubrizol Corporation, whose product name is “ 7067C". Hydrogenated polyisoprene star polymers are available from, for example, Infineum International Limited, under the trade names "SV200" and "SV600". Hydrogenated diene-styrene block copolymers are available from, for example, Infineum International Limited, under the trade name "SV 50".

[0176] In one embodiment of the invention, the amount of viscosity index improver used may be from 1.0 to 20% by weight, for example, from 5 to 15% by weight or from 8.0 to 12% by weight, based on the total weight of the formulated oil or lubricating engine oil.

[0177] Other additives - antioxidants

[0178] Antioxidants delay the oxidative degradation of base oils during use. This degradation can lead to deposits, sludge formation, or increased lubricant viscosity on metal surfaces. Those skilled in the art are aware of a variety of oxidation inhibitors that can be used in lubricant compositions.

[0179] Useful antioxidants include hindered phenols. These phenolic antioxidants can be ashless (metal-free) phenolic compounds or neutral or basic metal salts of specific phenolic compounds. Typical phenolic antioxidant compounds are sterically hindered phenolic compounds, which are compounds containing sterically hindered hydroxyl groups, and these compounds include those derivatives of dihydroxyaryl compounds in which the hydroxyl groups are located at ortho- or para-positions to each other. Typical phenolic antioxidants include those... 6+Alkyl group-substituted hindered phenols and alkylidene coupled derivatives of these hindered phenols. Examples of such phenolic materials are 2-tert-butyl-4- heptylphenol, 2-tert-butyl-4-octylphenol, 2-tert-butyl-4-dodecylphenol, 2,6-di-tert- butyl-4-heptylphenol, 2,6-di-tert-butyl-4-dodecylphenol, 2-methyl-6-tert-butyl-4- heptylphenol, and 2-methyl-6-tert-butyl-4-dodecylphenol. Other useful hindered monophenolic antioxidants can include, for example, hindered 2,6-dialkylphenol propionic acid ester derivatives. Bisphenolic antioxidants can also be advantageously used in combination with the present application. Examples of ortho-coupled phenols include: 2,2'-bis(4- heptyl-6-tert-butyl-phenol), 2,2'-bis(4-octyl-6-tert-butylphenol), and 2,2'-bis(4-dodecyl-6- tert-butylphenol). Para-coupled bisphenols include, for example, 4,4'-bis(2,6-di-tert- butylphenol) and 4,4'-methylenebis(2,6-di-tert-butylphenol).

[0180] An effective amount of one or more catalytic antioxidants can also be used. Catalytic antioxidants include: an effective amount of a) one or more oil-soluble polymeric metal organic compounds; and an effective amount of b) one or more substituted N,N'-diaryl-para- phenylenediamine compounds or c) one or more hindered phenol compounds; or a combination of both b) and c).

[0181] Non-phenolic oxidation inhibitors that can be used include aromatic amine antioxidants, and these can be used alone or in combination with phenolic compounds. Typical examples of non-phenolic antioxidants include: alkylated and non-alkylated aromatic amines, such as aromatic monoamines of the formula R 8 R 9 R 10 N, where R 8 is an aliphatic, aromatic, or substituted aromatic group, R 9 is an aromatic or substituted aromatic group, and R 10 is H, alkyl, aryl, or R 11 S(O)xR 12 , where R 11 is an alkylene, alkenylene, or aralkylene group, R 12 is a higher alkyl group or alkenyl, aryl, or alkaryl group, and x is 0, 1, or 2. The aliphatic group R 8 may contain from 1 to 20 carbon atoms, such as from 6 to 12 carbon atoms. The aliphatic group is an aliphatic group. In some embodiments, R 8 and R 9 are both aromatic or substituted aromatic groups, and the aromatic groups can be fused ring aromatic groups, such as naphthyl groups. The aromatic groups R 8 and R 9 may be linked together with other groups, such as S.

[0182] Typical aromatic amine antioxidants have alkyl substituents of at least 6 carbon atoms. Examples of aliphatic groups include hexyl, heptyl, octyl, nonyl, and decyl. Generally, the aliphatic group will contain no more than 14 carbon atoms. General classes of amine antioxidants useful in the present composition include diphenylamine, phenyl naphthylamine, phenothiazine, aminyl dibenzyl, and diphenyl phenylenediamine. Mixtures of two or more aromatic amines are also useful. Polymeric amine antioxidants can also be used. Specific examples of aromatic amine antioxidants useful in the present invention include: p,p'-dioctyl diphenylamine, t-octyl phenyl-alpha-naphthylamine, phenyl-alpha-naphthylamine, and p-octyl phenyl-alpha-naphthylamine.

[0183] Example amine antioxidants in the present invention include polymeric or oligomeric amines which are the polymerization reaction products of: one or more substituted or hydrocarbyl-substituted diphenylamines; one or more unsubstituted or hydrocarbyl-substituted phenyl naphthylamines; or one or more unsubstituted or hydrocarbyl-substituted diphenylamines and one or more unsubstituted or hydrocarbyl-substituted phenyl naphthylamines.

[0184] Polymeric or oligomeric amines are commercially available from Nyco S.A. under the trade name Nycoperf AO337. The polymeric or oligomeric amine antioxidant is present in an amount ranging from 0.5 to 10 wt% (active ingredient), for example 2 to 5 wt% (active ingredient), of the polymeric amine antioxidant, excluding any un-polymerized aryl amines that can be present or any added antioxidants. Sulfurized alkyl phenols and their alkali or alkaline earth metal salts are also useful antioxidants.

[0185] Example antioxidants also include hindered phenols, aryl amines. These antioxidants can be used alone or in combination with each other. Such additives can be used in amounts of 0.01 to 5 wt%, for example 0.01 to 1.5 wt%, 0.01 to 1.0 wt%, or 0.01 to 0.5 wt%.

[0186] Other additives - pour point depressants (PPD)

[0187] One or more pour point depressants (also known as lubricant flow improvers) can be added to the compositions of the present application, if desired. Pour point depressants can be added to the lubricating compositions of the present application to lower the minimum temperature at which the fluid will flow or be able to be poured. Examples of suitable pour point depressants include polymethacrylic alkyl esters, polymethacrylates, polyacrylates, polyaryl amides, acrylate-styrene copolymers, esterified olefin copolymers, alkylated polystyrenes, vinyl acetate-fumarate ester copolymers, condensation products of halogenated paraffins and aromatic compounds, vinyl ester carboxylic acid polymers, and terpolymers of dialkyl fumarate, vinyl ester of a fatty acid, and allyl vinyl ether. Such additives can be used in amounts of about 0.01 to 5 wt.%, for example, about 0.01 to 1.5 wt.%.

[0188] Other additives - seal compatibility agents

[0189] Seal compatibility agents help swell elastomeric seals by causing a chemical reaction in the fluid or a physical change in the elastomer. Suitable seal compatibility agents for lubricating oils include organic phosphate esters, aromatic esters, aromatic hydrocarbons, esters (e.g., butyl benzyl phthalate), and polybutenyl succinic anhydride. Such additives can be used in amounts of about 0.01 to 3 wt.%, for example, about 0.01 to 2 wt.%.

[0190] Other additives - antifoam agents

[0191] Antifoam agents can be advantageously added to lubricant compositions. These agents hinder the formation of stable froth. Silicones and organic polymers are typical antifoam agents. For example, polysiloxanes such as silicone oil or polydimethylsiloxane provide antifoam properties. Antifoam agents are commercially available and can be used in conventional small amounts with other additives such as demulsifiers, typically in a combined amount of less than 1 wt.% and often less than 0.1 wt.%.

[0192] Other additives - inhibitors and rust inhibitors

[0193] Rust-preventive additives (or corrosion inhibitors) are additives that protect lubricated metal surfaces from chemical attack by water or other contaminants. A variety of these additives are commercially available.

[0194] One type of rust-preventive additive is a polar compound that preferentially wets the metal surface to protect it with a film of oil. Another type of rust-preventive additive absorbs moisture by incorporating it into a water-in-oil emulsion so that only oil contacts the metal surface. Yet another type of rust-preventive additive chemically adheres to the metal to produce a non-reactive surface. Examples of suitable additives include zinc dithiophosphates, metal phenolates, basic metal sulfonates, fatty acids, and amines. Such additives can be used in amounts of about 0.01 to 5 wt.%, for example, about 0.01 to 1.5 wt.%.

[0195] Other additives - friction modifiers

[0196] A friction modifier is any material or materials that are capable of altering the coefficient of friction of a surface lubricated by any lubricant or fluid containing such material. If desired, friction modifiers, also known as friction reducers, or lubricants or oiliness agents, and other such agents that alter the ability of a base stock, formulated lubricant composition, or functional fluid to alter the coefficient of friction of a lubricated surface can be effectively combined for use with a base stock or lubricant composition of the present invention. Friction modifiers that reduce the coefficient of friction are particularly advantageous in combination with base stocks and lubricant compositions of the present invention.

[0197] Exemplary friction modifiers can include, for example, organometallic compounds or materials or mixtures thereof. Exemplary organometallic friction modifiers useful in lubricating engine oil formulations of the present invention include, for example, molybdenum amines, molybdenum diamines, organotungstate salts, molybdenum dithiocarbamates, molybdenum dithiophosphates, molybdenum amine complexes, molybdenum carboxylates, and the like, and mixtures thereof. Similar tungsten-based compounds can be preferred.

[0198] Other exemplary friction modifiers useful in lubricating engine oil formulations of the present invention include, for example, alkoxylated fatty acid esters, alkanolamides, polyol fatty acid esters, borated glycerol fatty acid esters, fatty alcohol ethers, and mixtures thereof.

[0199] Exemplary alkoxylated fatty acid esters include, for example, polyoxyethylene stearates, polyglycol fatty acid esters, and the like. These materials can include polyoxypropylene stearates, polyoxybutylene stearates, polyoxyethylene isostearates, polyoxypropylene isostearates, polyoxyethylene palmitates, and the like.

[0200] Exemplary alkanolamides include, for example, lauric acid diethyl alkanolamide, palmitic acid diethyl alkanolamide, and the like. These materials can include oleic acid diethyl alkanolamide, stearic acid diethyl alkanolamide, oleic acid diethyl alkanolamide, polyethoxylated hydrocarbyl amides, polypropoxylated hydrocarbyl amides, and the like.

[0201] Exemplary polyol fatty acid esters include, for example, glycerol monooleate; saturated mono-, di-, and tri-glycerides; glycerol monostearate; and the like. These materials can include polyol esters, hydroxyl-containing polyol esters, and the like.

[0202] Exemplary borated glycerol fatty acid esters include, for example: borated glycerol monooleate; borated saturated mono-, di-, and tri-glycerides; borated glycerol monostearate; and the like. In addition to glycerol polyols, these materials can also include trimethylolpropane, pentaerythritol, sorbitan, and the like. The esters can be mono-, di-, and sometimes tri-carboxylic acid esters of polyols. Examples can be: glycerol monooleate, glycerol dioleate, glycerol trioleate, glycerol monostearate, glycerol distearate, and glycerol tristearate; and the corresponding glycerol monopalmitate, glycerol dipalmitate, and glycerol tripalmitate; and the corresponding isostearate, linoleate, and the like. Sometimes, glycerol esters and mixtures containing any of these materials can be preferred. Ethoxylated, propoxylated, butoxylated fatty acid esters of polyols, especially using glycerol as the underlying polyol, can be preferred. Exemplary fatty alcohol ethers include, for example, stearyl ether, myristyl ether, and the like. Alcohols, including alcohols having a carbon number from C3 to C5, can be ethoxylated, propoxylated, or butoxylated to form the corresponding fatty alkyl ethers. The underlying alcohol moiety can be a stearyl, myristyl, C 11 -C 13 hydrocarbons, oil-based, isooctadecyl, and the like.

[0203] Useful concentrations of friction modifiers can range from 0.01 wt % to 5 wt %, or from about 0.1 wt % to about 2.5 wt %, or from about 0.1 wt % to about 1.5 wt %, or from about 0.1 wt % to about 1 wt %. Concentrations of molybdenum-containing materials are typically described in terms of molybdenum metal concentration. Advantageous concentrations of Mo can range from 25 ppm to 2000 ppm or more, sometimes ranging from 50 to 1500 ppm. All types of friction modifiers can be used alone or in mixtures with the materials of the present invention. Mixtures of two or more friction modifiers or mixtures of friction modifiers with alternative surface active materials are also desirable.

[0204] When the fluid composition includes one or more additives, the various additives are blended into the composition in amounts sufficient for them to perform their intended function in the application. The additives are typically present in the finished lubricant composition as minor components, typically in amounts of less than 50 wt %, such as less than about 30 wt %, and such as less than about 15 wt %, based on the total weight of the composition. The various additives are typically present in the finished lubricant composition in amounts of at least 0.01 wt %, such as at least 1 wt %, such as at least 5 wt %. Some additives, such as the detergent package, can be present in the finished lubricant composition in amounts of at least 10 wt %. The amounts of the additives useful in the finished lubricants of the present invention are shown in Table 3 below.

[0205] Many additives are shipped from the additive manufacturer as concentrates containing one or more additives along with an amount of base oil diluent. Thus, the weights in Table 3 below, and other amounts referred to herein, are amounts for active ingredients (i.e., the non-diluent portion of the ingredient). The weight percentages (wt%) shown below are based on the total weight of the finished lubricant composition.

[0206] Table 3

[0207]

[0208] The foregoing additives are generally available as commercially available materials. These additives can be added individually, but are typically incorporated in packages available from lubricant additive suppliers. Additive packages can be provided having a variety of ingredients, proportions, and characteristics; the necessary use of the final composition will be considered to select the appropriate package.

[0209] Because many types of lubricant additives are typically provided in pre-packaged mixtures, adjusting the relative amount of one additive in a finished engine oil lubricant often involves making similar adjustments to all other additives in a given additive package. Such adjustments can not be beneficial to the effectiveness of at least some other additives. For example, a reduction in the amount of antioxidant can result in a corresponding reduction in the amount of anti-wear additive, with the result that the fluid has a lower capacity for wear protection than before. However, it is expected that the performance advantages provided by formulating a fluid with the new Group II high viscosity base stock of the present invention in place of an existing Group I bright stock provides an opportunity to reformulate additive packages so that individual additives can be provided in different relative amounts in these reformulated packages than in current additive packages. Thus, it is expected that additive packages can be provided that enable the above-described adjustments to the relative amounts of individual additives without sacrificing other properties of the fluid.

[0210] Example finished fluids

[0211] The new Group II high viscosity base stock of the present invention is well suited as a lubricant base stock without blending restrictions, and in addition, is compatible with lubricant additives used in lubricant formulations. The lubricant base stock of the present invention can be blended with other lubricant base stocks to form a finished lubricant. Useful co-base lubricant base stocks include Group I, II, III, IV, and V base stocks and natural gas synthetic (GTL) oils. One or more co-base stocks can be blended into a lubricant composition that contains from 0.1 to 50 wt%, or from 0.5 to 40 wt%, 1 to 35 wt%, or from 2 to 30 wt%, or from 5 to 25 wt%, or from 10 to 20 wt% of the new Group II high viscosity base stock of the present invention based on the total finished lubricant composition.

[0212] Examples of the Class II high viscosity base stocks and fluid compositions of the present application can be used in a variety of lubricant-related end uses, such as in lubricating oils or greases for devices or equipment requiring lubrication of moving and / or interacting mechanical parts, components, or surfaces. Useful equipment includes engines and machines. The new Class II high viscosity base stocks of the present application can be suitable for formulating automotive crankcase lubricants, automotive gear oils, transmission oils, marine cylinder oils, marine trunk piston engine oils, passenger car engine oils, commercial vehicle engine oils, blended hybrid vehicle lubricants, plugged-in blended hybrid vehicle lubricants, battery electric vehicle lubricants, automotive greases, and many industrial lubricants, including but not limited to circulating lubricants, industrial gear lubricants, onshore wind turbine lubricants, offshore wind turbine lubricants, paper machine oils, industrial greases, compressor oils, pump oils, refrigeration lubricants, hydraulic lubricants, and metalworking fluids.

[0213] Four properties that are desirable for lubricants for applications such as those listed above are oxidation stability, good deposit control, high viscosity index, and fluid rheology that helps to pump the fluid at low temperatures.

[0214] Oxidation involves a chemical reaction between the lubricant and oxygen, resulting in the formation of sludge and varnish deposits that cause mechanical fouling. In addition, oxidation can undesirably increase the viscosity of the lubricant. As such, lubricants with good oxidation stability have a longer useful life than lubricants with poor oxidation stability, which allows for longer oil change intervals, thereby reducing downtime costs. While specific additives can enhance the oxidation stability of a lubricant, the additives are consumed over the course of the lubricant’s operation, whereby the effectiveness of the lubricant only continues as long as sufficient additives remain in the lubricant. Therefore, it can be desirable to formulate lubricants whose oxidation stability at least partially derives from the inherent properties of the lubricant base stocks.

[0215] Deposition control properties relate to the ability of a fluid to prevent the undesirable deposition of oxidation products and other contaminants on the surfaces of components. Oxidation products include the products of reactions between oxygen and some fluid additives, such as anti-wear chemicals. Undesirable material deposition can lead to fouling of components, so it is preferred that a fluid prevent such deposition. Although a fluid can have good oxidation stability, this does not mean that such a fluid will also have good deposition control. Oxidation relates to reactions between fluid constituents and oxygen, while deposition relates to what happens to the products of these reactions. On one hand, deposition control can involve maintaining reaction products and other solid contaminants suspended in the fluid, which is typically accomplished through the use of additives such as dispersants. Generally, dispersants work by attaching to solid contaminant particles, such that the dispersant molecules essentially surround each solid contaminant particle, thereby preventing agglomeration of the solid contaminant particles. As such, dispersants remain effective only as long as unused dispersant molecules remain in the fluid. On the other hand, deposition control can involve the dissolution of reaction products and other solid contaminants in the fluid. Generally, fluids containing a larger proportion of aromatic hydrocarbons can be more effective at dissolving some reaction products and other solid contaminants than fluids containing a smaller proportion of aromatic hydrocarbons. From both aspects of deposition control, it can be desirable to formulate a lubricant whose ability to dissolve and / or prevent agglomeration and deposition of solid contaminants derives at least in part from the inherent properties of the lubricant base stock.

[0216] The viscosity index of a lubricant provides an indication of how much the viscosity of the lubricant changes with temperature. Lubricants with high viscosity indices have less change in viscosity with temperature than lubricants with low viscosity indices. Thus, lubricants for use in equipment operating under a wide range of environmental conditions, such as extreme high and low temperature conditions, should have high viscosity indices. Although high viscosity indices can be achieved by adding viscosity index improvers to the lubricant formulation, it is not always beneficial to use such additives. For example, advances in engine, machine, and pump technology have resulted in smaller engines producing more power, machines operating at faster speeds, and smaller pumps producing higher pressures than their predecessors. Operating improvements like these place higher demands on lubricants, which must effectively operate under higher temperatures, higher pressures, and more severe shear conditions. For example, reduction gearboxes can operate with rapidly rotating components, which can result in deleterious shear of viscosity index improvers in the lubricating oil. Once a viscosity index improver molecule is sheared, it is no longer effective, whereby the viscosity profile and efficacy of the lubricant deteriorate, ultimately impairing the equipment. Thus, it can be desirable to formulate a lubricant with a high viscosity index that derives at least in part from the inherent properties of the lubricant base stock.

[0217] Fluid rheology at low temperatures can be thought of in terms of "flowability" or "pumpability" - a measure of the ease (or difficulty) of pumping a fluid at low temperatures. Low temperature rheological performance is most critical for mechanical devices such as machines and vehicles that operate in cold environments, particularly when such mechanical devices are started from rest. When at rest, the mechanical device can not have lubricant effectively distributed to its moving parts, so the contacting surfaces can experience a greater level of friction and wear upon start-up of the mechanical device than would be experienced during normal operation. This greater level of friction and wear can be detrimental to the operating efficiency and life of the mechanical device. The ability of the lubricant to resist such wear can be compromised at low temperatures. First, the viscosity of the lubricant tends to increase as the temperature decreases, thereby making it difficult to effectively distribute the lubricant at low temperatures. Second, the lubricant can begin to crystallize at low temperatures, which can exacerbate the effective distribution problem. Third, both of these effects hinder the migration of additive chemistry through the lubricant. Many anti-wear and extreme pressure additives that are intended to mitigate metal-on-metal wear function by reacting with the metal surfaces. Thus, the effectiveness of the additives depends at least in part on the additive being in contact with the metal surface. Hinderance of the migration of the additives within the fluid inhibits the contact of the additives with the metal surface, so the additives can not be as effective as when operating at higher temperatures.

[0218] To combat the above effects, the lubricant can be formulated so that it is relatively easy to pump upon start-up of the mechanical device, so that the lubricant and necessary additives can be effectively distributed to the moving parts in a short time interval. A typical measure of rheology of a lubricant is its viscosity at low temperatures. Generally, the lower the viscosity at a given low temperature, the more effectively the lubricant is distributed upon start-up of the mechanical device, and the less detrimental the cold start-up is to the equipment. For machines such as automotive vehicle engines that rely on battery electrical power to start, a problem can arise in that the energy required to start at low temperatures is compounded by the energy required to pump a high viscosity lubricant fluid, but the power output of the battery itself is reduced at low temperatures. Thus, a lubricant having a lower viscosity at low temperatures can at least partially compensate for the reduced power output of the battery at low temperatures.

[0219] While various additives can be used to enhance the low temperature rheology of a lubricant, such use can have adverse effects on other performance attributes of the lubricant, such as viscosity index or oxidation performance. In addition, the more additives that are used tend to increase the cost of the lubricant. Thus, it can be desirable to formulate a lubricant having improved low temperature rheology performance that is derived at least in part from the inherent properties of the lubricant base stock.

[0220] The various tests documented in the following examples provide side-by-side performance comparisons between lubricant fluids blended with Group II high viscosity base stocks of the present invention and equivalent fluids blended with Group I high viscosity base stocks. The performance comparisons include tests indicative of at least one of oxidative stability, deposit control, and low temperature rheology. Various side-by-side comparisons are made, with the only apparent difference between the test fluids of each example pair being the type of high viscosity base stock used in the blend. For some side-by-side comparisons, slight variations in the common blended base stocks as a minor component are necessary to achieve equivalent viscosity properties of the side-by-side test samples. In each side-by-side comparison, the same additive in the same amount by weight percent is blended into each fluid of the example pair of comparison fluids. Thus, for each pair of comparison test samples, the total weight percent of base stock is the same, and the only apparent difference between the two fluids of each pair is the use of a Group II high viscosity base stock of the present invention in one fluid and a Group I high viscosity base stock in the other.

[0221] With respect to oxidative stability, the test results cited below demonstrate that fluids blended with Group II high viscosity base stocks of the present invention exhibit better oxidative stability than comparison fluids blended with Group I high viscosity base stocks. For Group I base stocks, aromatic content can lead to poorer oxidative performance, but sulfur content can contribute to better oxidative performance. The presence of sufficient antioxidant additive in finished lubricants blended with Group I base stocks provides acceptable oxidative stability. Although Group II high viscosity base stocks of the present invention lack the aromatic content of Group I base stocks, it is expected that blends of Group II high viscosity base stocks of the present invention containing a substantial amount of Group I base stock will exhibit equivalent or slightly improved oxidative stability than comparison fluids blended with Group I base stocks alone having the same antioxidant content. However, the magnitude of the improvement in oxidative stability of fluids blended with Group II high viscosity base stocks of the present invention has been found to be significant.

[0222] With respect to deposit control, the test results cited below demonstrate that fluids blended with Group II high viscosity base stocks of the present invention exhibit similar deposit control capability as comparison fluids blended with Group I high viscosity base stocks. Group I base stocks contain substantially more aromatic hydrocarbons than Group II base stocks, and particularly Group II high viscosity base stocks of the present invention. For comparison pairs of fluids containing the same additives in the same proportions, it can be expected that the fluid containing more aromatic hydrocarbons will exhibit better deposit control. Despite the lack of aromatic hydrocarbons in Group II high viscosity base stocks of the present invention, it has been found that fluids blended with Group II high viscosity base stocks of the present invention can have equivalent or better deposit control capability.

[0223] With respect to low temperature rheology, the test results cited below show that fluids blended with the Class II high viscosity base stock of the present application exhibit much superior low temperature rheology than comparative fluids blended with a Class I high viscosity base stock. Although the Class I base stock can contain more wax than the Class II high viscosity base stock of the present application, it is expected that the additives used in the comparative tests will offset the effect of the wax present in the fluids blended with the Class I base stock. For a comparison of fluids containing the same additives in the same proportions, it can be expected that wax crystallization is controlled by the additives, so that the fluids blended with the Class I high viscosity base stock will exhibit similar (or only slightly inferior) low temperature rheology performance compared to the fluids blended with the Class II high viscosity base stock of the present application. Despite the presence of an equivalent amount of wax control additive in the comparative fluids blended with the Class I high viscosity base stock, it has been found that the fluids blended with the Class II high viscosity base stock of the present application can have superior, particularly significantly superior, low temperature rheology performance.

[0224] The Class II high viscosity base stock of the present application can be used to formulate fluids to help meet the needs for oxidation stability, deposit control, high viscosity index, and appropriate low temperature fluid rheology described above. For example, a finished lubricant formulation containing the Class II high viscosity base stock of the present application can have improved oxidation performance compared to existing comparative formulations, benefiting the end user with longer oil change intervals, thereby reducing equipment downtime and reducing operating expenses associated with lubricant disposal and replacement. Additionally or alternatively, a finished lubricant formulation containing the Class II high viscosity base stock of the present application and having a lower concentration of one or more additives than an existing comparative formulation can achieve at least comparable performance to the existing comparative formulation. Replacing a conventional Class I bright stock in a finished lubricant with the Class II high viscosity base stock of the present application can give the end user at least equivalent operating performance while also meeting applicable health, safety, and / or environmental regulations.

[0225] Other benefits of finished lubricant formulations having the Group II high viscosity base stock of the present disclosure can be realized where the lubricant is in a hotter environment or subjected to more severe operating conditions. Finished lubricant formulations having the Group II high viscosity base stock of the present disclosure can effectively reduce the amount of viscosity index improver compared to existing comparative lubricant formulations. Finished lubricant formulations having the Group II high viscosity base stock of the present disclosure can effectively reduce the amount of antioxidant compared to existing comparative lubricant formulations. In addition, the improved low temperature performance of finished lubricant formulations having the Group II high viscosity base stock of the present disclosure can enable a reduction or even elimination of the pour point depressant treat rate compared to existing comparative formulations blended with Group I bright stock. For example, while SAE grade 80W-90 automotive gear oil formulated with Group I bright stock can typically contain 1.0 to 2.0 wt% pour point depressant, an equivalent formulation having the Group II high viscosity base stock of the present disclosure instead of at least some of the Group I bright stock can only require 0.1 to 0.5 wt% pour point depressant to achieve comparable low temperature performance. For some high viscosity automotive gear oils (e.g., SAE grade 85W-140) formulated with the Group II high viscosity base stock of the present disclosure, the pour point depressant can be reduced to less than 0.1 wt%, less than 0.05 wt%, or eliminated. In addition, because of the performance benefits of finished lubricants having the Group II high viscosity base stock of the present disclosure, these finished lubricants can be more cost effective compared to lubricants formulated with more expensive Group III, Group IV, and Group V base stocks.

[0226] In keeping with the above, a method for improving the oxidative performance of a fluid can involve blending the fluid using the Group II high viscosity base stock of the present disclosure with one or more additives. The Group II high viscosity base stock can have any one or more of a viscosity index of at least 80, an aromatic content of less than 10 wt%, a sulfur content of less than 300 wppm, a kinematic viscosity at 100°C of at least 14 cSt, a kinematic viscosity at 40°C of at least 320 cSt, a pour point of -9°C or less, a cloud point of -2°C or less, and combinations thereof. The Group II high viscosity base stock can have an emulsion time at 82°C of about 15 minutes according to ASTM D1401. The sum of terminal / side propyl groups and terminal / side ethyl groups of the Group II high viscosity base stock can be at least 1.7 per 100 carbon atoms. The Group II high viscosity base stock can have an aromatic content of less than 8 wt%, less than 6 wt%, less than 4 wt%, or less than 2 wt%. The Group II high viscosity base stock can have a kinematic viscosity at 40°C of at least 350 cSt, at least 400 cSt, at least 450 cSt, at least 500 cSt, or at least 550 cSt. The Group II high viscosity base stock can have a T10 distillation point of at least 482°C.

[0227] The fluid can contain 20 wt.% or more, 30 wt.% or more, 40 wt.% or more, 50 wt.% or more, 60 wt.% or more, 70 wt.% or more, 75 wt.% or more, 80 wt.% or more, 85 wt.% or more, 90 wt.% or more, 93 wt.% or more, 95 wt.% or more, 97 wt.% or 99 wt.% or more of Group II high viscosity base stock. The fluid can have a saturated compound content of at least 60 wt.%, at least 70 wt.%, 80 wt.%, at least 85 wt.%, at least 90 wt.%, at least 95 wt.% or at least 98 wt.%. The fluid can have a KV100 increase of 6% or less, 5% or less, 4% or less, 3% or less or about 2% as measured according to ASTM D2893. The fluid can have an oxidation performance as represented by an increase in kinematic viscosity at 100°C (KV100) as measured according to L-60-1 test bench test (ASTM D5704) of 30% or less, 25% or less, 20% or less or about 5% to 15%.

[0228] Additionally or alternatively, the fluid can exhibit excellent deposit control performance. The fluid can have an average carbon / sludge rating of 8 to 10 as measured according to ASTM D5704, where 10 is the maximum rating under the test. The fluid can have an average sludge rating of 8 to 10 as measured according to ASTM D5704, where 10 is the maximum rating under the test. The fluid can have an average sludge rating of 9 to 10 as measured according to ASTM D5704.

[0229] Additionally or alternatively, the fluid can have an antioxidant additive content of 5 wt.% or less, 2 wt.% or less or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the above fluid can have a viscosity index improver additive content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the above fluid can have a polyalphaolefin content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid can have a pour point depressant additive content of 5 wt.% or less, 3 wt.% or less or 0.01 wt.% to 1 wt.%. In one embodiment, the above fluid can be suitable for use as an automotive gear oil.

[0230] A method of improving the low temperature rheological properties of a fluid can involve blending a fluid using a Group II high viscosity base stock of the present application with one or more additives. The Group II high viscosity base stock can have any one or more of a viscosity index of at least 80, an aromatic content of less than 10 wt%, a sulfur content of less than 300 wppm, a kinematic viscosity at 100°C of at least 14 cSt, a kinematic viscosity at 40°C of at least 320 cSt, a pour point of -9°C or less, a cloud point of -2°C or less, and combinations thereof. The Group II high viscosity base stock can have an emulsion time at 82°C of about 15 minutes according to ASTM D1401. The sum of terminal / side propyl groups and terminal / side ethyl groups of the Group II high viscosity base stock can be at least 1.7 per 100 carbon atoms. The Group II high viscosity base stock can have an aromatic content of less than 8 wt%, less than 6 wt%, less than 4 wt%, or less than 2 wt%. The Group II high viscosity base stock can have a kinematic viscosity at 40°C of at least 350 cSt, at least 400 cSt, at least 450 cSt, at least 500 cSt, or at least 550 cSt. The Group II high viscosity base stock can have a T10 distillation point of at least 482°C.

[0231] The fluid can contain 20 wt% or more, 30 wt% or more, 40 wt% or more, 50 wt% or more, 60 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more, 90 wt% or more, 93 wt% or more, 95 wt% or more, 97 wt% or 99 wt% or more of the Group II high viscosity base stock. The fluid can have a saturated compound content of at least 60 wt%, at least 70 wt%, 80 wt%, at least 85 wt%, at least 90 wt%, at least 95 wt%, or at least 98 wt%.

[0232] The fluid can have a Brookfield viscosity at -12°C of 70,000 mPa-s or less, 60,000 mPa-s or less, 50,000 mPa-s or less, 40,000 mPa-s or less, or 30,000 mPa-s to 40,000 mPa-s, measured according to ASTM D2983.

[0233] Additionally or alternatively, the fluid can have a Brookfield viscosity at -26°C of 150,000 mPa-s or less, 140,000 mPa-s or less, 130,000 mPa-s or less, 120,000 mPa-s or less, 110,000 mPa-s or less, 100,000 mPa-s or less, 90,000 mPa-s or less, 80,000 mPa-s or less, or 70,000 mPa-s to 80,000 mPa-s, measured according to ASTM D2983.

[0234] Additionally or alternatively, the fluid can have a MRV apparent viscosity at -15°C of 17,000 mPa-s or less, 16,000 mPa-s or less, 15,000 mPa-s or less, or 14,000 mPa-s to 15,000 mPa-s, measured according to ASTM D4684.

[0235] Additionally or alternatively, the fluid can have an antioxidant additive content of 5 wt% or less, 2 wt% or less, or 0.01 wt% to 1 wt%. Additionally or alternatively, the fluid can have a viscosity index improver additive content of 10 wt% or less, 5 wt% or less, 2 wt% or less, or 0.01 wt% to 1 wt%. Additionally or alternatively, the fluid can have a polyalphaolefin content of 10 wt% or less, 5 wt% or less, 2 wt% or less, or 0.01 wt% to 1 wt%. Additionally or alternatively, the fluid can have a pour point depressant additive content of 5 wt% or less, 3 wt% or less, or 0.01 wt% to 1 wt%. In one embodiment, the fluid can be suitable for use as an automotive gear oil. In one embodiment, the fluid can be suitable for use as an engine oil.

[0236] The Group II high viscosity base stock of the present application can be used to formulate fluids having any combination of two or more properties related to oxidative stability, high viscosity index, and fluid rheology that facilitates pumping of the fluid at low temperatures.

[0237] Thus, a method of improving the life and performance of a fluid can involve blending a fluid using a Group II high viscosity base stock of the present application with one or more additives. The Group II high viscosity base stock can have any one or more of a viscosity index of at least 80, an aromatic content of less than 10 wt%, a sulfur content of less than 300 wppm, a kinematic viscosity at 100°C of at least 14 cSt, a kinematic viscosity at 40°C of at least 320 cSt, a pour point of -9°C or less, a cloud point of -2°C or less, and combinations thereof. The Group II high viscosity base stock can have an emulsion time at 82°C of about 15 minutes according to ASTM D1401. The sum of terminal / side propyl groups and terminal / side ethyl groups of the Group II high viscosity base stock can be at least 1.7 per 100 carbon atoms. The Group II high viscosity base stock can have an aromatic content of less than 8 wt%, less than 6 wt%, less than 4 wt%, or less than 2 wt%. The Group II high viscosity base stock can have a kinematic viscosity at 40°C of at least 350 cSt, at least 400 cSt, at least 450 cSt, at least 500 cSt, or at least 550 cSt. The Group II high viscosity base stock can have a T10 distillation point of at least 482°C.

[0238] The fluid can contain 20 wt% or more, 30 wt% or more, 40 wt% or more, 50 wt% or more, 60 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more, 90 wt% or more, 93 wt% or more, 95 wt% or more, 97 wt% or 99 wt% or more of the Group II high viscosity base stock. The fluid can have a saturated compound content of at least 60 wt%, at least 70 wt%, 80 wt%, at least 85 wt%, at least 90 wt%, at least 95 wt%, or at least 98 wt%. The fluid can have a KV100 increase of 6% or less, 5% or less, 4% or less, 3% or less, or about 2% as measured according to ASTM D2893. The fluid can have a KV100 increase of 30% or less, 25% or less, 20% or less, or about 5% to 15% as measured according to L-60-1 test stand test (ASTM D5704).

[0239] Additionally or alternatively, the fluid can exhibit excellent deposit control performance. The fluid can have an average carbon / oil sludge rating of 8 to 10 as measured according to ASTM D5704, where 10 is the maximum rating under the test. The fluid can have an average sludge rating of 8 to 10 as measured according to ASTM D5704, where 10 is the maximum rating under the test. The fluid can have an average sludge rating of 9 to 10 as measured according to ASTM D5704.

[0240] Additionally or alternatively, the fluid can have a Brookfield viscosity at -12°C of 70,000 mPa-s or less, 60,000 mPa-s or less, 50,000 mPa-s or less, 40,000 mPa-s or less, or 30,000 mPa-s to 40,000 mPa-s, measured according to ASTM D2983.

[0241] Additionally or alternatively, the fluid can have a Brookfield viscosity at -26°C of 150,000 mPa-s or less, 140,000 mPa-s or less, 130,000 mPa-s or less, 120,000 mPa-s or less, 110,000 mPa-s or less, 100,000 mPa-s or less, 90,000 mPa-s or less, 80,000 mPa-s or less, or 70,000 mPa-s to 80,000 mPa-s, measured according to ASTM D2983.

[0242] Additionally or alternatively, the fluid can have an MRV apparent viscosity at -15°C of 17,000 mPa-s or less, 16,000 mPa-s or less, 15,000 mPa-s or less, or 14,000 mPa-s to 15,000 mPa-s, measured according to ASTM D4684.

[0243] Additionally or alternatively, the fluid can have an antioxidant additive content of 5 wt% or less, 2 wt% or less, or 0.01 wt% to 1 wt%. Additionally or alternatively, the fluid can have a viscosity index improver additive content of 10 wt% or less, 5 wt% or less, 2 wt% or less, or 0.01 wt% to 1 wt%. Additionally or alternatively, the fluid can have a polyalphaolefin content of 10 wt% or less, 5 wt% or less, 2 wt% or less, or 0.01 wt% to 1 wt%. Additionally or alternatively, the fluid can have a pour point depressant additive content of 5 wt% or less, 3 wt% or less, or 0.01 wt% to 1 wt%. In one embodiment, the fluid can be suitable for use as an automotive gear oil. In one embodiment, the fluid can be suitable for use as an engine oil.

[0244] The fluids of the present disclosure suitable for use as industrial lubricants can contain about 90 wt% of a Group II high viscosity base stock of the present disclosure, where the base stock has a saturates content of about 90 wt% (i.e., such that the fluid itself has a saturates content of at least 80 wt%). The Group II high viscosity base stock can have any one or more of: a viscosity index of at least 80, an aromatics content of less than 10 wt%, a sulfur content of less than 300 wppm, a kinematic viscosity at 100°C of at least 14 cSt, a kinematic viscosity at 40°C of at least 320 cSt, a pour point of -9°C or less, a cloud point of -2°C or less, and combinations thereof. The Group II high viscosity base stock can have an emulsion time at 82°C of about 15 minutes according to ASTM D1401. The sum of terminal / side propyl groups and terminal / side ethyl groups of the Group II high viscosity base stock can be at least 1.7 per 100 carbon atoms. The Group II high viscosity base stock can have an aromatics content of less than 8 wt%, less than 6 wt%, less than 4 wt%, or less than 2 wt%. The Group II high viscosity base stock can have a kinematic viscosity at 40°C of at least 350 cSt, at least 400 cSt, at least 450 cSt, at least 500 cSt, or at least 550 cSt. The Group II high viscosity base stock can have a T10 distillation point of at least 482°C.

[0245] The fluid can contain 20 wt% or more, 30 wt% or more, 40 wt% or more, 50 wt% or more, 60 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more, 90 wt% or more, 93 wt% or more, 95 wt% or more, 97 wt% or 99 wt% or more of the Group II high viscosity base stock. The fluid can have a saturates content of at least 85 wt%, at least 90 wt%, at least 95 wt%, or at least 98 wt%. The fluid can have a KV100 increase of 6% or less, 5% or less, 4% or less, 3% or less, or about 2% as measured according to ASTM D2893.

[0246] Additionally or alternatively, the fluid can have an antioxidant additive content of 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid described above can have a viscosity index improver additive content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid described above can have a polyalphaolefin content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid can have a pour point depressant additive content of 5 wt.% or less, 3 wt.% or less, or 0.01 wt.% to 1 wt.%. In an embodiment, the fluid described above can be suitable for use as an automotive gear oil. In an embodiment, the fluid described above can be suitable for use as an industrial gear oil. In an embodiment, the fluid described above can be suitable for use as an industrial gear oil of the paper machine oil type.

[0247] A fluid of the present disclosure suitable for use as an automotive gear oil can contain 20 wt.% or more, 30 wt.% or more, 40 wt.% or more, 50 wt.% or more, 60 wt.% or more, 70 wt.% or more, 75 wt.% or more, 80 wt.% or more, 85 wt.% or more, 90 wt.% or more, 93 wt.% or more, 95 wt.% or more, 97 wt.% or 99 wt.% or more of a Group II high viscosity base stock. For example, a fluid of the present disclosure can contain about 70 wt.% of a Group II high viscosity base stock of the present disclosure, where the base stock has a saturates content of about 90 wt.% (i.e., such that the fluid itself has a saturates content of at least 60 wt.%). The Group II high viscosity base stock can have any one or more of a viscosity index of at least 80, an aromatics content of less than 10 wt.%, a sulfur content of less than 300 wppm, a kinematic viscosity at 100°C of at least 14 cSt, a kinematic viscosity at 40°C of at least 320 cSt, a pour point of -9°C or less, a cloud point of -2°C or less, and combinations thereof. The Group II high viscosity base stock can have an emulsion time at 82°C of about 15 minutes according to ASTM D1401. The sum of terminal / side propyl groups and terminal / side ethyl groups of the Group II high viscosity base stock can be at least 1.7 per 100 carbon atoms. The Group II high viscosity base stock can have an aromatics content of less than 8 wt.%, less than 6 wt.%, less than 4 wt.%, or less than 2 wt.%. The Group II high viscosity base stock can have a kinematic viscosity at 40°C of at least 350 cSt, at least 400 cSt, at least 450 cSt, at least 500 cSt, or at least 550 cSt. The Group II high viscosity base stock can have a T10 distillation point of at least 482°C.

[0248] The fluid can contain about 80 wt.% or more, 85 wt.% or more, 90 wt.% or more, or 95 wt.% or more of Group II high viscosity base stock. The fluid can have a saturated compound content of at least 70 wt.%, at least 80 wt.%, at least 85 wt.%, at least 90 wt.%, or at least 95 wt.%. The fluid can have a Brookfield viscosity of 70,000 mPa-s or less, 60,000 mPa-s or less, 50,000 mPa-s or less, 40,000 mPa-s or less, or 30,000 mPa-s to 40,000 mPa-s at -12°C measured according to ASTM D2983.

[0249] Additionally or alternatively, the above fluid can have a Brookfield viscosity of 150,000 mPa-s or less, 140,000 mPa-s or less, 130,000 mPa-s or less, 120,000 mPa-s or less, 110,000 mPa-s or less, 100,000 mPa-s or less, 90,000 mPa-s or less, 80,000 mPa-s or less, or 70,000 mPa-s to 80,000 mPa-s at -26°C measured according to ASTM D2983.

[0250] Additionally or alternatively, the fluid can have an antioxidant additive content of 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the above fluid can have a viscosity index improver additive content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the above fluid can have a polyalphaolefin content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid can have a pour point depressant additive content of 5 wt.% or less, 3 wt.% or less, or 0.01 wt.% to 1 wt.%. In one embodiment, the above fluid can be suitable for use as an automotive gear oil.

[0251] The fluids of the present application can be suitable for use as engine oils. Engine oils are intended for use in gasoline and diesel engines and generally contain base stock and additives. Generally, the base stock is the major component in these fluids and therefore has a large impact on the performance of the engine oil. Typically, today's wide variety of engine oils contain a blend of a small number of individual lubricant base stocks and individual additives. Engine oils generally contain 80 wt% or more of base stock, with the remainder being various additives. The engine oil can contain 85 wt% or more of base oil, 90 wt% or more of base oil, or 95 wt% or more of base oil. A base stock or two or more base stocks can comprise the base oil. Generally, a higher proportion of Group II high viscosity base stock will be used in higher viscosity engine oils. However, because the base oil can comprise a plurality of base stocks, Group II high viscosity base stock can also be blended into relatively lighter viscosity engine oil products. In this case, an extreme bimodal blend can be obtained, where Group II high viscosity base stock is blended with a light base stock to obtain a blended base oil within a desired viscosity range.

[0252] The fluids of the present application can contain 20 wt% or more, 30 wt% or more, or 40 wt% or more of the Group II high viscosity base stock of the present application. The Group II high viscosity base stock can have a saturates content of about 90 wt% or more. The Group II high viscosity base stock can have any one or more of the following: a viscosity index of at least 80, an aromatic compound content of less than 10 wt%, a sulfur content of less than 300 wppm, a kinematic viscosity at 100°C of at least 14 cSt, a kinematic viscosity at 40°C of at least 320 cSt, a pour point of -9°C or less, a cloud point of -2°C or less, and combinations thereof. The Group II high viscosity base stock can have an emulsion time at 82°C of about 15 minutes according to ASTM D 1401. The sum of terminal / side propyl groups and terminal / side ethyl groups of the Group II high viscosity base stock can be at least 1.7 per 100 carbon atoms. The Group II high viscosity base stock can have an aromatic compound content of less than 8 wt%, less than 6 wt%, less than 4 wt%, or less than 2 wt%. The Group II high viscosity base stock can have a kinematic viscosity at 40°C of at least 350 cSt, at least 400 cSt, at least 450 cSt, at least 500 cSt, or at least 550 cSt. The Group II high viscosity base stock can have a T10 distillation point of at least 482°C.

[0253] The fluid can contain about 50 wt.% or more, 60 wt.% or more, or 70 wt.% or more of the Group II high viscosity base stock. The fluid can have a saturates content of at least 80 wt.%, at least 85 wt.%, or at least 90 wt.%. The fluid can have an MRV apparent viscosity at -15°C of 17,000 mPa-s or less, 16,000 mPa-s or less, 15,000 mPa-s or less, or 14,000 mPa-s to 15,000 mPa-s, measured according to ASTM D4684.

[0254] Additionally or alternatively, the fluid can have an antioxidant additive content of 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid can have a viscosity index improver additive content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid can have a polyalphaolefin content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid can have a pour point depressant additive content of 5 wt.% or less, 3 wt.% or less, or 0.01 wt.% to 1 wt.%. In one embodiment, the fluid can be suitable for use as an engine oil.

[0255] In another embodiment, the fluid of the present application can contain 20 wt.% or more, 30 wt.% or more, 40 wt.% or more of the Group II high viscosity base stock of the present application. The Group II high viscosity base stock can have a saturates content of about 90 wt.% or more. The Group II high viscosity base stock can have any one or more of the following: a viscosity index of at least 80, an aromatic compound content of less than 10 wt.%, a sulfur content of less than 300 wppm, a kinematic viscosity at 100°C of at least 14 cSt, a kinematic viscosity at 40°C of at least 320 cSt, a pour point of -9°C or less, a cloud point of -2°C or less, and combinations thereof. The Group II high viscosity base stock can have an emulsion time at 82°C of about 15 minutes according to ASTM D1401. The sum of the terminal / side propyl groups and the terminal / side ethyl groups of the Group II high viscosity base stock can be at least 1.7 per 100 carbon atoms. The Group II high viscosity base stock can have an aromatic compound content of less than 8 wt.%, less than 6 wt.%, less than 4 wt.%, or less than 2 wt.%. The Group II high viscosity base stock can have a kinematic viscosity at 40°C of at least 350 cSt, at least 400 cSt, at least 450 cSt, at least 500 cSt, or at least 550 cSt. The Group II high viscosity base stock can have a T10 distillation point of at least 482°C.

[0256] The fluid can contain about 50 wt.% or more, 60 wt.% or more, 70 wt.% or more, 75 wt.% or more, 80 wt.% or more, 85 wt.% or more, 90 wt.% or more, or 95 wt.% or more of Group II high viscosity base stock. The fluid can have a saturates content of at least 70 wt.%, at least 80 wt.%, at least 85 wt.%, at least 90 wt.%, or at least 95 wt.%. The fluid can have a KV100 increase of 30% or less, 25% or less, 20% or less, or about 5% to 15% as measured by the L-60-1 Rig Test (ASTM D5704).

[0257] Additionally or alternatively, the fluid can have a carbon deposit / sludge rating of 10 or less as measured by the L-60-1 Rig Test (ASTM D5704). Additionally or alternatively, the fluid described above can have a carbon deposit / sludge rating of about 8 to about 9 as measured by the L-60-1 Rig Test (ASTM D5704). Additionally or alternatively, the fluid described above can have a sludge rating of 10 or less by the L-60-1 Rig Test (ASTM D5704).

[0258] Additionally or alternatively, the fluid can have an antioxidant additive content of 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid described above can have a viscosity index improver additive content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid described above can have a polyalphaolefin content of 10 wt.% or less, 5 wt.% or less, 2 wt.% or less, or 0.01 wt.% to 1 wt.%. Additionally or alternatively, the fluid can have a pour point depressant additive content of 5 wt.% or less, 3 wt.% or less, or 0.01 wt.% to 1 wt.%. In one embodiment, the fluid described above can be suitable for use as an automotive gear oil.

[0259] In another embodiment, a method of making a deposit-resistant fluid can include combining a base stock with one or more additives to form a blended fluid configured to resist the formation of deposits in an oxidizing environment. The base stock can have a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock can include greater than or equal to about 90 wt.% saturated compounds, less than or equal to about 10 wt.% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms.

[0260] Additionally or alternatively, the base stock can have a T10 distillation point of at least 482 °C. Additionally or alternatively, the base stock can have a pour point of -9 °C or less and / or a cloud point of -2 °C or less.

[0261] The blended fluid can be selected from the group consisting of base oils, lubricants, process fluids, hydraulic fluids, industrial fluids, automotive fluids, and combinations thereof. The blended fluid can be configured to resist oxidation in an oxidizing environment. The oxidizing environment can include temperatures up to 250 °F (121 °C) or up to 302 °F (150 °C) or up to 325 °F (163 °C). The oxidizing environment can include air. The oxidizing environment can include water. The blended fluid can be configured to resist the formation of deposits in the presence of a metal agent for at least 50 hours at temperatures up to 325 °F (163 °C). The metal agent can be any one of copper, steel, iron, and combinations thereof.

[0262] The blended fluid can be configured to maintain fluidity in a low temperature environment. The blended fluid can have a MRV apparent viscosity at -15 °C of 17,000 mPa-s or less, 16,000 mPa-s or less, 15,000 mPa-s or less, or 14,000 mPa-s to 15,000 mPa-s, measured according to ASTM D4684. Additionally or alternatively, the blended fluid can have a Brookfield viscosity at -12 °C of 70,000 mPa-s or less, 60,000 mPa-s or less, 50,000 mPa-s or less, 40,000 mPa-s or less, or 30,000 mPa-s to 40,000 mPa-s, measured according to ASTM D2983. Additionally or alternatively, the blended fluid can have a Brookfield viscosity at -26 °C of 150,000 mPa-s or less, 140,000 mPa-s or less, 130,000 mPa-s or less, 120,000 mPa-s or less, 110,000 mPa-s or less, 100,000 mPa-s or less, 90,000 mPa-s or less, 80,000 mPa-s or less, or 70,000 mPa-s to 80,000 mPa-s, measured according to ASTM D2983.

[0263] In another embodiment, a method for reducing deposit formation can include introducing a base stock into a blended fluid. The base stock can have a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock can include greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and at least 1.7 total end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms. The addition of the base stock to the blended fluid can improve the ability of the blended fluid to resist deposit formation in an oxidizing environment.

[0264] Additionally or alternatively, the base stock can have a T10 distillation point of at least 482°C. Additionally or alternatively, the base stock can have a pour point of -9°C or less and / or a cloud point of -2°C or less.

[0265] The blended fluid can be selected from the group consisting of base oils, lubricants, process fluids, hydraulic fluids, industrial fluids, automotive fluids, and combinations thereof. The blended fluid can be configured to resist oxidation in an oxidizing environment after the introduction of the base stock. The oxidizing environment can include temperatures of up to 250°F (121°C) or up to 302°F (150°C) or up to 325°F (163°C). The oxidizing environment can include air. The oxidizing environment can include water. The blended fluid can be configured to resist deposit formation in the presence of a metal agent at temperatures of up to 325°F (163°C) for at least 50 hours. The metal agent can be any one of copper, steel, iron, and combinations thereof.

[0266] In another embodiment, a method for mitigating deposit formation in equipment can include introducing a blended fluid to a metal component of the equipment. The blended fluid can include a base stock and one or more additives. The base stock can have a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock can include greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and at least 1.7 total end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms. The blended fluid can be configured to resist deposit formation in an oxidizing environment.

[0267] Additionally or alternatively, the base stock can have a T10 distillation point of at least 482°C. Additionally or alternatively, the base stock can have a pour point of -9°C or less and / or a cloud point of -2°C or less.

[0268] The blended fluid can be selected from the group consisting of base oils, lubricants, process fluids, hydraulic fluids, industrial fluids, automotive fluids, and combinations thereof. The blended fluid can be configured to resist oxidation in an oxidizing environment. The oxidizing environment can include temperatures up to 250°F (121°C) or up to 302°F (150°C) or up to 325°F (163°C). The oxidizing environment can include air. The oxidizing environment can include water. The blended fluid can be configured to resist the formation of deposits in the presence of a metal agent at temperatures up to 325°F (163°C) for at least 50 hours. The metal agent can be any one of copper, steel, iron, and combinations thereof.

[0269] In another embodiment, the anti-deposit fluid can include a base stock and one or more additives. The base stock can have a viscosity index of at least 80 and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt. The base stock can include greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms. The anti-deposit fluid can be configured to maintain flowability in a low temperature environment and resist the formation of deposits in an oxidizing environment.

[0270] Additionally or alternatively, the base stock can have a T10 distillation point of at least 482°C. Additionally or alternatively, the base stock can have a pour point of -9°C or less and / or a cloud point of -2°C or less.

[0271] The anti-deposit fluid can be selected from the group consisting of base oils, lubricants, process fluids, hydraulic fluids, industrial fluids, automotive fluids, and combinations thereof. The anti-deposit fluid can be configured to resist oxidation in an oxidizing environment. The oxidizing environment can include temperatures up to 250°F (121°C) or up to 302°F (150°C) or up to 325°F (163°C). The oxidizing environment can include air. The oxidizing environment can include water. The anti-deposit fluid can be configured to resist the formation of deposits in the presence of a metal agent at temperatures up to 325°F (163°C) for at least 50 hours. The metal agent can be any one of copper, steel, iron, and combinations thereof.

[0272] The anti-deposit fluid can be configured to remain flowable in low temperature environments. The anti-deposit fluid can have a MRV apparent viscosity of 17,000 mPa-s or less, 16,000 mPa-s or less, 15,000 mPa-s or less, or 14,000 mPa-s to 15,000 mPa-s at -15 °C, measured according to ASTM D4684. Additionally or alternatively, the anti-deposit fluid can have a Brookfield viscosity of 70,000 mPa-s or less, 60,000 mPa-s or less, 50,000 mPa-s or less, 40,000 mPa-s or less, or 30,000 mPa-s to 40,000 mPa-s at -12 °C, measured according to ASTM D2983. Additionally or alternatively, the anti-deposit fluid can have a Brookfield viscosity of 150,000 mPa-s or less, 140,000 mPa-s or less, 130,000 mPa-s or less, 120,000 mPa-s or less, 110,000 mPa-s or less, 100,000 mPa-s or less, 90,000 mPa-s or less, 80,000 mPa-s or less, or 70,000 mPa-s to 80,000 mPa-s at -26 °C, measured according to ASTM D2983.

[0273] Examples

[0274] The above benefits and other benefits of using Group II high viscosity base stocks to formulate fluids in place of Group I base stocks are demonstrated in the following examples. A wide range of industry standard bench and test rig tests were used to test the performance of exemplary fluids blended with Group II base stocks of the present application. Many performance advantages were observed in the formulated fluids containing the new Group II high viscosity base stocks compared to blends containing Group I base stocks. In addition, other performance attributes were observed to be at least comparable, and often better, than blends containing Group I base stocks.

[0275] For the following examples, the Group II high viscosity base stocks were derived from low severity deasphalting of a resid fraction to form a deasphalted oil. The deasphalted oil was subjected to demetallization, hydrotreating, hydrocracking, hydrodewaxing, and hydrofinishing to make a high saturates base stock having the same viscosity range as a conventional Group I bright stock.

[0276] Example 1 : Paper Machine Oil; U.S. Steel Oxidation Test

[0277] In this example, a paper machine oil corresponding to ISO 320 specification formulated with a Group I bright stock (Sample 1) was tested to compare with an equivalent paper machine oil corresponding to ISO 320 specification formulated with a Group II high viscosity base stock of the present application (Sample 2). In this example, the formulation of Sample 2 was very similar to that of Sample 1 except that the Group II high viscosity base stock of the present application was used in Sample 2 in place of the Group I bright stock of Sample 1. The amount of Group I heavy neutral base stock was fine-tuned to match the viscosity in the two formulated blends. As such, Samples 1 and 2 contained the same additives in the same proportions as the corresponding base stock blend. The sample compositions are provided in Table 4.

[0278] Table 4

[0279]

[0280] The samples were observed for oxidative stability benefits by ASTM D2893 (American Steel Oxidation) test. This test demonstrates the oxidation resistance of industrial lubricating oils in the presence of high temperature and oxygen. The oil is subjected to 95 to 121 °C for 312 hours. The kinematic viscosity at 100 °C (KV100) of the oil is measured before and after the test; an increase in viscosity indicates the oxidation resistance of the oil. Figure 1 The KV100 increase values for the two samples in this example are illustrated. Sample 1 (a fluid blended from a Group I bright stock base) experienced a 7% KV100 increase, while Sample 2 (a fluid blended from a Group II high viscosity base stock of the present application) experienced only a 4% KV100 increase. The KV100 increase in this test is caused by the oxidation of the lubricant being tested. Thus, the greater the observed KV100 increase, the lower the oxidation resistance of the lubricant being tested. Therefore, it would be expected that a lubricant subjected to this test would exhibit a lower KV100 increase value. Here, Sample 2 experienced a KV100 increase far less than that experienced by Sample 1, and thus, it was judged that Sample 2 had superior oxidation stability. Given that the only difference between the formulations of Sample 1 and Sample 2 was the type of base stock, it can be concluded that the improved oxidation stability performance of Sample 2 was due to the use of a Group II high viscosity base stock of the present application in its formulation.

[0281] Example 2: Industrial Gear Oil; American Steel Oxidation Test

[0282] In this example, a commercial gear oil corresponding to ISO 460 specification formulated with a Group I bright stock oil (Sample 3) was tested for comparison with the same commercial gear oil formulated with a Group II high viscosity base stock of the present application (Sample 4). In this example, the formulation of Sample 4 was very similar to that of Sample 3 except that a Group II high viscosity base stock of the present application was used in Sample 4 in place of the Group I bright stock oil of Sample 3. The amount of Group I heavy neutral base stock was fine-tuned to match the viscosities in the two formulated blends. As such, Samples 3 and 4 contained the same additives in the same proportions as the corresponding base stock blend. The sample compositions are provided in Table 5.

[0283] Table 5

[0284]

[0285] The samples were observed for oxidative stability benefits by ASTM D2893 (American Petroleum Institute Oxidation). The test conditions were the same as those of Example 1. Figure 1 The KV100 increase values for the two samples in this example are illustrated. Sample 3 (a fluid blended from a Group I bright stock base stock) experienced a 6% KV100 increase, while Sample 4 (a fluid blended from a Group II high viscosity base stock of the present application) experienced only a 2% KV100 increase. As such, Sample 4 experienced a much smaller KV100 increase than Sample 3, and therefore was judged to have superior oxidative stability. Since the only difference between the formulations of Sample 3 and Sample 4 was the type of base stock, it can be concluded that the improved oxidative stability performance of Sample 4 was due to the use of a Group II high viscosity base stock of the present application in its formulation.

[0286] Example 3: Automotive Gear Oil; Brookfield Viscosity Test

[0287] In this example, a sample 5 corresponding to an automotive gear oil formulated with a Group I bright stock oil of 85W-140 grade was tested for comparison with a sample 6 corresponding to an equivalent automotive gear oil of 85W-140 grade formulated with a Group II high viscosity base stock of the present application. In this example, the formulation of sample 6 was very similar to that of sample 5 except that the Group II high viscosity base stock of the present application was used in sample 6 in place of the Group I bright stock oil of sample 5. The amount of Group I low viscosity base stock was fine-tuned to match the viscosity in the two formulated blends. As such, the fluids of samples 5 and 6 contained the same additives in the same proportions as the respective blended base stocks. In addition, in this example, a sample 7 corresponding to an automotive gear oil formulated with a Group I bright stock oil of 80W-90 grade was tested for comparison with a sample 8 corresponding to an equivalent automotive gear oil of 85W-140 grade formulated with a Group II high viscosity base stock of the present application. In this example, the formulation of sample 8 was very similar to that of sample 7 except that the Group II high viscosity base stock of the present application was used in sample 8 in place of the Group I bright stock oil of sample 7. The amount of Group I low viscosity base stock was fine-tuned to match the viscosity in the two formulated blends. As such, the fluids of samples 7 and 8 contained the same additives in the same proportions as the respective blended base stocks. The sample compositions are provided in Table 6.

[0288] Table 6

[0289]

[0290] The low temperature test for automotive gear oils, automatic transmission fluids, torque and tractor fluids, and industrial and automotive hydraulic oils is the ASTM D2983 Brookfield Viscosity Test. In this test, the sample is preheated and then allowed to come to room temperature. The sample is then cooled to the specified test temperature and then analyzed (along with a reference fluid) by a rotational viscometer. The test determines the low shear rate viscosity of the sample at the specified test temperature. In this example, samples 5 and 6 were tested at -12°C and samples 7 and 8 were tested at -26°C.

[0291] Figure 2 The Brookfield viscosity values for the four samples of this example are illustrated. Sample 5 (a fluid blended from a Group I bright stock base stock) had a Brookfield viscosity of 83,600 mPa-s, while sample 6 (a fluid blended from a Group II high viscosity base stock of the present application) had a Brookfield viscosity of 31,800 mPa-s. Thus, the Brookfield viscosity of sample 6 was much less than that of sample 5, and so sample 6 was judged to have superior low temperature performance. Given that the only difference between the formulations of sample 5 and sample 6 was the type of base stock, it can be concluded that the improved low temperature performance of sample 6 was due to the use of a Group II high viscosity base stock of the present application in its formulation.

[0292] Still referring to Figure 2 Sample 7 (fluid blended from a Group I bright stock) had a Brookfield viscosity of 203,200 mPa-s, while Sample 8 (fluid blended from a Group II high viscosity base stock of the present application) had a Brookfield viscosity of 74,400 mPa-s. Thus, the Brookfield viscosity of Sample 8 was much less than that of Sample 7, and it was judged that Sample 8 had superior low temperature performance. In view of the fact that the only difference between the formulations of Sample 7 and Sample 8 was the type of base stock, it can be concluded that the low temperature performance improvement of Sample 8 was due to the use of a Group II high viscosity base stock of the present application in its formulation.

[0293] Example 4: Automotive engine oil; MRV apparent viscosity test

[0294] In this example, an engine oil corresponding to a 25W-50 grade formulated with a Group I bright stock (Sample 9) was tested for comparison with an equivalent engine oil corresponding to a 25W-50 grade formulated with a Group II high viscosity base stock of the present application (Sample 10). In this example, the formulation of Sample 10 was very similar to that of Sample 9, except that a Group II high viscosity base stock of the present application was used in Sample 10 in place of the Group I bright stock of Sample 9. The amount of Group I low viscosity base stock was fine-tuned to match the viscosity in the two formulated blends. As a result, the fluids of Samples 9 and 10 contained the same additives in the same proportions as the respective base stocks. The sample compositions are provided in Table 7.

[0295] Table 7

[0296]

[0297] The low temperature test for engine oil is the ASTM D4684 Mini Rotary Viscometer (MRV) apparent viscosity test. This is a key test for automotive engine oils as it helps determine the viscosity grade and the ability to pump oil at low temperatures. This test is a low temperature, low shear test in which the oil is slowly cooled and then subjected to a low shear viscosity test. Samples 9 and 10 were cooled at a rate of 0.3 °C / hour in the range of -8 to -20 °C, which is the temperature range in which most wax formation occurs. According to the SAE J300 engine oil classification standard, the test temperature for this 25W engine oil is -15 °C, and a maximum MRV apparent viscosity of 60,000 mPa-s is the pass standard.

[0298] Figure 3The MRV apparent viscosity values for two samples exemplifying this example are shown. Sample 9 (a fluid blended from a Group I bright stock base stock) had an MRV apparent viscosity of 20,500 mPa-s at a test temperature of -15°C, while Sample 10 (a fluid blended from a Group II high viscosity base stock of the present application) had an MRV viscosity of 14,000 mPa-s at a test temperature of -15°C. Thus, Sample 10 had a much lower MRV apparent viscosity than Sample 9, and therefore was judged to have superior low temperature performance. In view of the fact that the only difference between the formulations of Sample 9 and Sample 10 was the type of base stock, it can be concluded that the improved low temperature performance of Sample 10 was due to the use of a Group II high viscosity base stock of the present application in its formulation.

[0299] Example 5: Automotive Gear Oil; L-60-1 Test Stand Testing

[0300] In this example, an automotive gear oil corresponding to a 85W-140 grade formulated with a Group I bright stock (Sample 11) was tested for comparison to an equivalent automotive gear oil corresponding to a 85W-140 grade formulated with a Group II high viscosity base stock of the present application (Sample 12). In this example, the formulation of Sample 12 was very similar to that of Sample 11 except that a Group II high viscosity base stock of the present application was used in Sample 12 in place of the Group I bright stock of Sample 11. The amount of Group I low viscosity base stock was fine-tuned to match the viscosities in the two formulated blends. As such, the fluids of Samples 11 and 12 contained the same additives in the same proportions as the respective base stocks. In addition, in this example, another automotive gear oil corresponding to a 85W-140 grade formulated with a Group I bright stock (Sample 13) was tested for comparison to another equivalent automotive gear oil corresponding to a 85W-140 grade formulated with a Group II high viscosity base stock of the present application (Sample 14). In this example, the formulation of Sample 14 was identical to that of Sample 13 except that a Group II high viscosity base stock of the present application was used in Sample 14 in place of the Group I bright stock of Sample 13. As such, the fluids of Samples 13 and 14 contained the same additives in the same proportions as the respective blended base stocks. The sample compositions are provided in Table 8.

[0301] Table 8

[0302]

[0303] Samples 11, 12, 13, and 14 were subjected to L-60-1 test stand testing (ASTM D5704), which tests the thermal and oxidative stability of automotive gear oils. The results of this test indicate the deposit control ability of an automotive gear oil formulation. In this test, the sample oil and catalyst are supplied to a gear case, which is then heated to 325°F (163°C) and run for 50 hours with the gears engaged. The kinematic viscosity at 100°C (KV100) of the sample oil is measured before and after the test; an increase in viscosity indicates the oil's resistance to oxidation. Figure 4 The KV100 increase values for the four samples of this example are illustrated. Sample 11, a fluid blended from a Group I bright stock base stock, experienced a 48% KV100 increase, while Sample 12, a fluid blended from a Group II high viscosity base stock of the present application, experienced only an 11% KV100 increase. The KV100 increase in this test is caused by oxidation of the test lubricant. Thus, the greater the observed KV100 increase, the lower the resistance to oxidation of the test lubricant. Therefore, it is desirable for a lubricant subjected to this test to exhibit a low KV100 increase value. Here, Sample 12 experienced a KV100 increase far less than that experienced by Sample 11, thus it is judged that Sample 12 has superior oxidative stability. Given that the only difference between the formulations of Sample 11 and Sample 12 is the type of base stock, it can be concluded that the improved oxidative stability of Sample 12 is due to the use of a Group II high viscosity base stock of the present application in its formulation.

[0304] Figure 4 The KV100 increase values for Samples 13 and 14 are also illustrated. Sample 13, a fluid blended from a Group I bright stock base stock, experienced a 35% KV100 increase, while Sample 14, a fluid blended from a Group II high viscosity base stock of the present application, experienced only a 14% KV100 increase. Sample 14 experienced a KV100 increase far less than that experienced by Sample 11, thus it is judged that Sample 14 has superior oxidative stability. Given that the only difference between the formulations of Sample 13 and Sample 14 is the type of base stock, it can be concluded that the improved oxidative stability of Sample 14 is due to the use of a Group II high viscosity base stock of the present application in its formulation.

[0305] The results also provide some insight into the potential expected variation between lubricants formulated from different batches of their components. For example, although both Sample 11 and Sample 13 were formulated from Group I bright stock and exhibited properties consistent with the 85W-140 category, the L-60-1 test results indicated that Sample 11 experienced greater degradation than Sample 13. Similarly, Sample 12 and Sample 14, both formulated from fresh Group II high viscosity base stock, experienced different degrees of degradation, although the difference here was less than the difference exhibited between Sample 11 and 13. Without being bound by any one particular theory, it is believed that this difference between ostensibly similar samples can be explained by differences in any one or more of the different additive chemistries within the additive package, different concentrations of the additive package, and / or detailed compositional differences between the base stocks.

[0306] Despite the above discussion, the results are consistent in that similar substitution of Group II high viscosity base stock for Group I bright stock resulted in fluids with higher oxidative stability.

[0307] The L-60-1 test bench test also has two key deposit test parameters: carbon / oil sludge rating and sludge rating. Sample 11 (a fluid blended from a Group I bright stock base) and 12 (a fluid blended from a Group II high viscosity base stock of the present invention) were compared in both ratings. Because Sample 11 contains a greater proportion of aromatic compounds due to the Group I bright stock base of Sample 11 than Sample 12, it can be expected that Sample 11 would exhibit better carbon / oil sludge and sludge ratings. Without being bound by any one particular theory, it is believed that the aromatic compounds found in Group I base stocks provide solubilization capacity for early oxidation products and sludge, and thus the dearth of aromatic compounds in a fresh Group II high viscosity base stock base is expected to result in poorer deposit control. Nonetheless, as shown in Tables 3 and 4, respectively, Figure 5 and 6 Sample 11 and 12 exhibited nearly identical carbon / oil sludge and sludge ratings. These results collectively indicate that lubricants formulated with Group II high viscosity base stocks of the present invention in place of Group I bright stock bases have higher oxidative stability without any loss in deposit control. Thus, lubricants formulated with Group II high viscosity base stocks of the present invention bases have higher thermal stability than equivalent lubricants formulated with Group I bright stocks.

[0308] Other embodiments

[0309] The present invention also provides the following embodiments, each of which can be considered to optionally include any alternative embodiment.

[0310] Embodiment 1. A method comprising: blending a base stock and one or more additives to form a lubricating fluid, wherein: the base stock has a T10 distillation point of at least 482°C, a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt; and comprises: greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and at least 1.7 total end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms; the lubricating fluid has an oxidation performance, as represented by an increase in kinematic viscosity at 100°C (KV100) measured according to ASTM D5704, of 30% or less; and the lubricating fluid has an average carbon deposit / sludge rating measured according to ASTM D5704 of 8 to 10 or an average sludge rating measured according to ASTM D5704 of 8 to 10.

[0311] Embodiment 2. The method of any of the preceding embodiments, wherein the lubricating fluid has an oxidation performance, as represented by an increase in kinematic viscosity at 100°C (KV100) measured according to ASTM D5704, of 20% or less.

[0312] Embodiment 3. The method of any of the preceding embodiments, wherein the lubricating fluid has an oxidation performance, as represented by an increase in kinematic viscosity at 100°C (KV100) measured according to ASTM D5704, of 15% or less.

[0313] Embodiment 4. The method of any of the preceding embodiments, wherein the lubricating fluid has an average sludge rating measured according to ASTM D5704 of 8 to 10.

[0314] Embodiment 5. The method of any of the preceding embodiments, wherein the lubricating fluid has an average sludge rating measured according to ASTM D5704 of 9 to 10.

[0315] Embodiment 6. The method of any of the preceding embodiments, wherein the lubricating fluid has a Brookfield viscosity measured according to ASTM D2983 of 70,000 mPa-s or less at -12°C.

[0316] Embodiment 7. The method of any of the preceding embodiments, wherein the lubricating fluid has a Brookfield viscosity measured according to ASTM D2983 of 30,000 mPa-s to 40,000 mPa-s at -12°C.

[0317] Embodiment 8. The method of any of the preceding embodiments, wherein the lubricating fluid has a Brookfield viscosity measured according to ASTM D2983 of 150,000 mPa-s or less at -26°C.

[0318] Embodiment 9. The method of any of the preceding embodiments, wherein the lubricating fluid has a Brookfield viscosity measured according to ASTM D2983 of 70,000 mPa-s to 100,000 mPa-s at -26°C.

[0319] Embodiment 10. The method of any of the preceding embodiments, wherein the lubricating fluid has a pour point depressant additive content of 0.7 wt% or less.

[0320] Embodiment 11. The method of any of the preceding embodiments, wherein the lubricating fluid has a pour point depressant additive content of 0.3 wt% or less.

[0321] Embodiment 12. The method of any of the preceding embodiments, wherein the lubricating fluid has a polyalphaolefin content of 10 wt% or less.

[0322] Embodiment 13. The method of any of the preceding embodiments, wherein the lubricating fluid has a polyalphaolefin content of 5 wt% or less.

[0323] Embodiment 14. The method of any of the preceding embodiments, wherein the lubricating fluid has a polyalphaolefin content of 0.01 wt% to 1 wt%.

[0324] Embodiment 15. The method of any of the preceding embodiments, wherein the base stock has a viscosity index of 80 to 120.

[0325] Embodiment 16. The method of any of the preceding embodiments, wherein the lubricating fluid has a viscosity index improver additive content of 5 wt% or less.

[0326] Embodiment 17. The method of any of the preceding embodiments, wherein the lubricating fluid has a viscosity index improver additive content of 0.01 wt% to 1 wt%.

[0327] Embodiment 18. The method of any of the preceding embodiments, wherein the lubricating fluid has a viscosity index improver selected from the group consisting of: polymers of polyacrylate, polymers of methacrylate, polymers of butadiene, polymers of olefin, polymers of alkylated styrene, copolymers of methacrylate, copolymers of butadiene, copolymers of olefin, copolymers of alkylated styrene, copolymers of ethylene, copolymers of propylene, block copolymers of hydrogenated styrene, block copolymers of hydrogenated isoprene, and combinations thereof.

[0328] Embodiment 19. The method of any of the preceding embodiments, wherein the lubricating fluid has a saturates content of at least 70 wt.%.

[0329] Embodiment 20. The method of any of the preceding embodiments, wherein the lubricating fluid has a saturates content of at least 80 wt.%.

[0330] Embodiment 21. The method of any of the preceding embodiments, wherein the lubricating fluid has an antioxidant additive content of 0.1 wt.% or less.

[0331] Embodiment 22. The method of any of the preceding embodiments, wherein the lubricating fluid has an antioxidant additive content of 0.01 wt.% to 0.05 wt.%.

[0332] Embodiment 23. The method of any of the preceding embodiments, wherein the lubricating fluid is an automotive gear oil.

[0333] Embodiment 24. A lubricating fluid comprising: a base stock and one or more additives, wherein: the base stock has a T10 distillation point of at least 482°C, a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt; and comprises: greater than or equal to about 90 wt.% saturates, less than or equal to about 10 wt.% aromatics, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms; the lubricating fluid has an oxidation performance, as represented by an increase in kinematic viscosity at 100°C (KV100) measured according to ASTM D5704, of 30% or less; and the lubricating fluid has an average carbon deposit / sludge rating measured according to ASTM D5704 of 8 to 10 or an average sludge rating measured according to ASTM D5704 of 8 to 10.

[0334] Embodiment 25. The lubricating fluid of embodiment 24, wherein the lubricating fluid has an oxidation performance, as represented by an increase in kinematic viscosity at 100°C (KV100) measured according to ASTM D5704, of 20% or less.

[0335] Embodiment 26. The lubricating fluid of any one of embodiments 24 to 25, wherein the lubricating fluid has an oxidation performance, as represented by an increase in kinematic viscosity at 100°C (KV100) measured according to ASTM D5704, of 15% or less.

[0336] Embodiment 27. The lubricating fluid of any one of embodiments 24 to 26, wherein the lubricating fluid has an average sludge rating, measured according to ASTM D5704, of 8 to 10.

[0337] Embodiment 28. The lubricating fluid of any one of embodiments 24 to 27, wherein the lubricating fluid has an average sludge rating, measured according to ASTM D5704, of 9 to 10.

[0338] Embodiment 29. The lubricating fluid of any one of embodiments 24 to 28, wherein the lubricating fluid has a Brookfield viscosity, measured according to ASTM D2983, of 70,000 mPa-s or less at -12°C.

[0339] Embodiment 30. The lubricating fluid of any one of embodiments 24 to 29, wherein the lubricating fluid has a Brookfield viscosity, measured according to ASTM D2983, of 30,000 mPa-s to 40,000 mPa-s at -12°C.

[0340] Embodiment 31. The lubricating fluid of any one of embodiments 24 to 30, wherein the lubricating fluid has a Brookfield viscosity, measured according to ASTM D2983, of 150,000 mPa-s or less at -26°C.

[0341] Embodiment 32. The lubricating fluid of any one of embodiments 24 to 31, wherein the lubricating fluid has a Brookfield viscosity, measured according to ASTM D2983, of 70,000 mPa-s to 100,000 mPa-s at -26°C.

[0342] Embodiment 33. The lubricating fluid of any one of embodiments 24 to 32, wherein the lubricating fluid has a pour point depressant additive content of 0.7 wt% or less.

[0343] Embodiment 34. The lubricating fluid of any of embodiments 24-33, wherein the lubricating fluid has a pour point depressant additive content of 0.3 wt.% or less.

[0344] Embodiment 35. The lubricating fluid of any of embodiments 24-34, wherein the lubricating fluid has a poly-alpha-olefin content of 10 wt.% or less.

[0345] Embodiment 36. The lubricating fluid of any of embodiments 24-35, wherein the lubricating fluid has a poly-alpha-olefin content of 5 wt.% or less.

[0346] Embodiment 37. The lubricating fluid of any of embodiments 24-36, wherein the lubricating fluid has a poly-alpha-olefin content of 0.01 wt.% to 1 wt.%.

[0347] Embodiment 38. The lubricating fluid of any of embodiments 24-37, wherein the base stock has a viscosity index of 80 to 120.

[0348] Embodiment 39. The lubricating fluid of any of embodiments 24-38, wherein the lubricating fluid has a viscosity index improver additive content of 5 wt.% or less.

[0349] Embodiment 40. The lubricating fluid of any of embodiments 24-39, wherein the lubricating fluid has a viscosity index improver additive content of 0.01 wt.% to 1 wt.%.

[0350] Embodiment 41. The lubricating fluid of any of embodiments 24-40, wherein the lubricating fluid has a viscosity index improver selected from the group consisting of a polyacrylate, a polymer of methacrylate, a polymer of butadiene, a polymer of an olefin, a polymer of an alkylated styrene, a copolymer of methacrylate, a copolymer of butadiene, a copolymer of an olefin, a copolymer of an alkylated styrene, a copolymer of ethylene, a copolymer of propylene, a block copolymer of hydrogenated styrene, a block copolymer of hydrogenated isoprene, and combinations thereof.

[0351] Embodiment 42. The lubricating fluid of any of embodiments 24-41, wherein the lubricating fluid has a saturated compound content of at least 70 wt.%.

[0352] Embodiment 43. The lubricating fluid of any of embodiments 24-42, wherein the lubricating fluid has a saturated compound content of at least 80 wt.%.

[0353] Embodiment 44. The lubricating fluid of any one of embodiments 24-43, wherein the lubricating fluid has an antioxidant additive content of 0.1 wt% or less.

[0354] Embodiment 45. The lubricating fluid of any one of embodiments 24-44, wherein the lubricating fluid has an antioxidant additive content of 0.01 wt% to 0.05 wt%.

[0355] Embodiment 46. The lubricating fluid of any one of embodiments 24-45, wherein the lubricating fluid is an automotive gear oil.

[0356] Embodiment 47. A method of making a deposit-resistant fluid, the method comprising: combining a base stock and one or more additives to form a blended fluid, the blended fluid configured to remain flowable in a low temperature environment and resist formation of deposits in an oxidizing environment; wherein the base stock has a viscosity index of at least 80 and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt; and wherein the base stock comprises: greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and at least 1.7 total end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms.

[0357] Embodiment 48. The method of embodiment 47, wherein the oxidizing environment comprises a temperature of up to 325°F (163°C); and the blended fluid is an automotive fluid configured to resist oxidation in the oxidizing environment and configured to resist formation of deposits in the oxidizing environment for at least 50 hours.

[0358] Embodiment 49. The method of any one of embodiments 47 and 48, wherein the blended fluid has an average carbon deposit / sludge rating measured according to ASTM D5704 of 8 to 10.

[0359] Embodiment 50. The method of any one of embodiments 47-49, wherein the blended fluid has an average sludge rating measured according to ASTM D5704 of 8 to 10.

[0360] Embodiment 51. The method of any one of embodiments 47-50, wherein the blended fluid has an average sludge rating measured according to ASTM D5704 of 9 to 10.

[0361] Embodiment 52. The method of any one of embodiments 47-51, wherein the blended fluid is an automotive gear oil and the low temperature environment comprises a temperature as low as -26°C.

[0362] Embodiment 53. The method of any one of embodiments 47-51, wherein the blended fluid is an automotive engine oil, and the low temperature environment comprises a temperature as low as -30°C.

[0363] Embodiment 54. The method of any one of embodiments 47-52, wherein the blended fluid has a Brookfield viscosity measured according to ASTM D2983 of 70,000 mPa-s or less at -12°C.

[0364] Embodiment 55. The method of any one of embodiments 47-52 and 54, wherein the blended fluid has a Brookfield viscosity measured according to ASTM D2983 of 50,000 mPa-s or less at -12°C.

[0365] Embodiment 56. The method of any one of embodiments 47-52, 54, and 55, wherein the blended fluid has a Brookfield viscosity measured according to ASTM D2983 of 30,000 mPa-s to 40,000 mPa-s at -12°C.

[0366] Embodiment 57. The method of any one of embodiments 47-52, wherein the blended fluid has a Brookfield viscosity measured according to ASTM D2983 of 150,000 mPa-s or less at -26°C.

[0367] Embodiment 58. The method of any one of embodiments 47-52 and 57, wherein the blended fluid has a Brookfield viscosity measured according to ASTM D2983 of 120,000 mPa-s or less at -26°C.

[0368] Embodiment 59. The method of any one of embodiments 47-52 and 57-58, wherein the blended fluid has a Brookfield viscosity measured according to ASTM D2983 of 70,000 mPa-s to 100,000 mPa-s at -26°C.

[0369] Embodiment 60. The method of any one of embodiments 47-51 and 53, wherein the blended fluid has an MRV viscosity measured according to ASTM D4684 of 18,000 mPa-s or less at -15°C.

[0370] Embodiment 61. The method of any one of embodiments 47-51, 53, and 60, wherein the blended fluid has an MRV viscosity measured according to ASTM D4684 of 17,000 mPa-s or less at -15°C.

[0371] Embodiment 62. The method of any of embodiments 47-51, 53, and 60-61, wherein the blended fluid has an MRV viscosity measured according to ASTM D4684 of 16,000 mPa-s or less at -15 °C.

[0372] Embodiment 63. The method of any of embodiments 47-51, 53, and 60-62, wherein the blended fluid has an MRV viscosity measured according to ASTM D4684 of 14,000 mPa-s to 15,000 mPa-s at -15 °C.

[0373] Embodiment 64. An anti-deposit fluid comprising: a base stock and one or more additives, wherein: the base stock has a viscosity index of at least 80, and a kinematic viscosity of at least 320 cSt at 40 °C or a kinematic viscosity of at least 14 cSt at 100 °C; the base stock comprises: greater than or equal to about 90 wt% saturated compounds, less than or equal to about 10 wt% aromatic compounds, and at least 1.7 total end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms; the anti-deposit fluid is configured to remain flowable in a low temperature environment and is configured to resist forming deposits in an oxidizing environment.

[0374] Embodiment 65. The anti-deposit fluid of embodiment 64, wherein the oxidizing environment comprises a temperature of up to 325 °F (163 °C); and the anti-deposit fluid is an automotive fluid configured to resist forming deposits for at least 50 hours in the oxidizing environment.

[0375] Embodiment 66. The anti-deposit fluid of any of embodiments 64 and 65, wherein the anti-deposit fluid has an average carbon deposit / sludge rating measured according to ASTM D5704 of 8 to 10.

[0376] Embodiment 67. The anti-deposit fluid of any of embodiments 64-66, wherein the anti-deposit fluid has an average sludge rating measured according to ASTM D5704 of 8 to 10.

[0377] Embodiment 68. The anti-deposit fluid of any of embodiments 64-67, wherein the anti-deposit fluid has an average sludge rating measured according to ASTM D5704 of 9 to 10.

[0378] Embodiment 69. The anti-deposit fluid of any of embodiments 64-68, wherein the anti-deposit fluid is an automotive gear oil, and the low temperature environment comprises a temperature as low as -26 °C.

[0379] Embodiment 70. The anti-deposition fluid of any one of embodiments 64-68, wherein the anti-deposition fluid is an automotive engine oil, and the low temperature environment comprises temperatures as low as -30 °C.

[0380] Embodiment 71. The anti-deposition fluid of any one of embodiments 64-69, wherein the anti-deposition fluid has a Brookfield viscosity measured according to ASTM D2983 of 70,000 mPa-s or less at -12 °C.

[0381] Embodiment 72. The anti-deposition fluid of any one of embodiments 64-69 and 71, wherein the anti-deposition fluid has a Brookfield viscosity measured according to ASTM D2983 of 50,000 mPa-s or less at -12 °C.

[0382] Embodiment 73. The anti-deposition fluid of any one of embodiments 64-69, 71, and 72, wherein the anti-deposition fluid has a Brookfield viscosity measured according to ASTM D2983 of 30,000 mPa-s to 40,000 mPa-s at -12 °C.

[0383] Embodiment 74. The anti-deposition fluid of any one of embodiments 64-69, wherein the anti-deposition fluid has a Brookfield viscosity measured according to ASTM D2983 of 150,000 mPa-s or less at -26 °C.

[0384] Embodiment 75. The anti-deposition fluid of any one of embodiments 64-69 and 74, wherein the anti-deposition fluid has a Brookfield viscosity measured according to ASTM D2983 of 120,000 mPa-s or less at -26 °C.

[0385] Embodiment 76. The anti-deposition fluid of any one of embodiments 64-69 and 74-75, wherein the anti-deposition fluid has a Brookfield viscosity measured according to ASTM D2983 of 70,000 mPa-s to 100,000 mPa-s at -26 °C.

[0386] Embodiment 77. The method of any one of embodiments 64-68 and 70, wherein the anti-deposition fluid has an MRV viscosity measured according to ASTM D4684 of 18,000 mPa-s or less at -15 °C.

[0387] Embodiment 78. The anti-deposition fluid of any one of embodiments 64-68, 70, and 77, wherein the anti-deposition fluid has an MRV viscosity measured according to ASTM D4684 of 17,000 mPa-s or less at -15 °C.

[0388] Embodiment 79. The anti-deposit fluid of any one of embodiments 64-68, 70, and 77-78, wherein the anti-deposit fluid has an MRV viscosity measured according to ASTM D4684 of 16,000 mPa-s or less at -15 °C.

[0389] Embodiment 80. The anti-deposit fluid of any one of embodiments 64-68, 70, and 77-79, wherein the blended fluid has an MRV viscosity measured according to ASTM D4684 of 14,000 mPa-s to 15,000 mPa-s at -15 °C.

[0390] Embodiment 81. The anti-deposit fluid of any one of embodiments 64-80, wherein the anti-deposit fluid is configured to resist oxidation in the oxidizing environment.

[0391] Embodiment 82. The anti-deposit fluid of any one of embodiments 64-81, wherein the anti-deposit fluid has an increase in kinematic viscosity at 100 °C (KV100) measured according to ASTM D5704 of 30% or less.

[0392] Embodiment 83. The anti-deposit fluid of any one of embodiments 64-82, wherein the anti-deposit fluid has an increase in kinematic viscosity at 100 °C (KV100) measured according to ASTM D5704 of 20% or less.

[0393] Embodiment 84. The anti-deposit fluid of any one of embodiments 64-83, wherein the anti-deposit fluid has an increase in kinematic viscosity at 100 °C (KV100) measured according to ASTM D5704 of 15% or less.

[0394] All numerical values within the specific embodiments and claims herein can be modified by “about” or “approximately,” and consideration is given to experimental error and variations in the measurements.

[0395] When numerical lower limits and numerical upper limits are listed separately herein, ranges from any lower limit to any upper limit are contemplated. While the exemplary embodiments of the application have been described in detail, it should be apparent that various modifications can be made thereto without departing from the spirit and scope of the application. Accordingly, the scope of the claims should not be limited to the examples and descriptions described herein, but should be given the full scope of the patent to which the claims are entitled including all equivalents of the features of the application to which the claims are entitled as well as all equivalents of the features described herein as they would be treated by those skilled in the art as equivalents.

[0396] While the foregoing is directed to implementations of the present application, other and further implementations of the application can be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims.

Claims

1. A method comprising: blending a base stock with at least one other base stock and one or more additives to form a lubricating fluid, the base stock having a T10 distillation point of at least 482°C, a viscosity index of at least 80, and a kinematic viscosity at 40°C of at least 320 cSt or a kinematic viscosity at 100°C of at least 14 cSt; and comprising greater than or equal to 90 wt% saturated compounds, less than or equal to 10 wt% aromatic compounds, and at least 1.7 total end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms, wherein the at least one other base stock comprises a Group I base stock having a kinematic viscosity at 100°C of 12 cSt or less, wherein the lubricating fluid has a saturated compound content of at least 70 wt% and less than 90 wt% and has an oxidation performance represented by an increase in kinematic viscosity at 100°C (KV100) measured according to ASTM D5704 of 15% or less; and the lubricating fluid also has an average carbon deposit / sludge rating measured according to ASTM D5704 of 8 to 10 or an average sludge rating measured according to ASTM D5704 of 8 to 10.

2. The method of claim 1, wherein the lubricating fluid has an average sludge rating measured according to ASTM D5704 of 8 to 10.

3. The method of claim 1, wherein the lubricating fluid has an average sludge rating measured according to ASTM D5704 of 9 to 10.

4. The method of claim 1, wherein the lubricating fluid has a Brookfield viscosity measured according to ASTM D2983 of 70,000 mPa-s or less at -12°C.

5. The method of claim 1, wherein the lubricating fluid has a Brookfield viscosity measured according to ASTM D2983 of 30,000 mPa-s to 40,000 mPa-s at -12°C.

6. The method of claim 1, wherein the lubricating fluid has a Brookfield viscosity measured according to ASTM D2983 of 150,000 mPa-s or less at -26°C.

7. The method of claim 1, wherein the lubricating fluid has a Brookfield viscosity measured according to ASTM D2983 of 70,000 mPa-s to 100,000 mPa-s at -26°C.

8. The method of claim 1, wherein the lubricating fluid has a pour point depressant additive content of 0.7 wt% or less.

9. The method of claim 1, wherein the lubricating fluid has a pour point depressant additive content of 0.3 wt% or less.

10. The method of claim 1, wherein the lubricating fluid has a polyalphaolefin content of 10 wt% or less.

11. The method of claim 1, wherein the lubricating fluid has a polyalphaolefin content of 5 wt% or less.

12. The method of claim 1, wherein the lubricating fluid has a polyalphaolefin content of 0.01 wt% to 1 wt%.

13. The method of claim 1, wherein the base stock has a viscosity index of 80 to 120.

14. The method of claim 1, wherein the lubricating fluid has a viscosity index improver additive content of 5 wt% or less.

15. The method of claim 1, wherein the lubricating fluid has a viscosity index improver additive content of 0.01 wt% to 1 wt%.

16. The method of claim 1, wherein the lubricating fluid has a saturated compound content of at least 80 wt%.

17. A method of making a deposit-resistant fluid, the method comprising: combining a base stock with at least one other base stock and one or more additives to form a blended fluid, the blended fluid configured to remain flowable in a low temperature environment and to resist forming deposits in an oxidizing environment; wherein the base stock has a viscosity index of at least 80 and a kinematic viscosity of at least 320 cSt at 40°C or a kinematic viscosity of at least 14 cSt at 100°C; and wherein the base stock comprises: greater than or equal to 90 wt% saturated compounds, less than or equal to 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms, wherein the at least one other base stock comprises a Group I base stock having a kinematic viscosity of 12 cSt or less at 100°C, and wherein the deposit-resistant fluid comprises a saturated compound content of at least 70 wt% and less than 90 wt% and wherein the blended fluid has an average carbon deposit / sludge rating of 8 to 10 measured according to ASTM D5704.

18. The method of claim 17, wherein the oxidizing environment comprises a temperature of up to 325°F (163°C); and the blended fluid is an automotive fluid configured to resist oxidation in the oxidizing environment and configured to resist forming deposits in the oxidizing environment for at least 50 hours.

19. The method of claim 17, wherein the deposit-resistant fluid has an MRV apparent viscosity of 17,000 mPa-s or less at -15°C measured according to ASTM D4684.

20. A deposit-resistant fluid comprising: a base stock with at least one other base stock and one or more additives, wherein: the base stock has a viscosity index of at least 80 and a kinematic viscosity of at least 320 cSt at 40°C or a kinematic viscosity of at least 14 cSt at 100°C; the base stock comprises: greater than or equal to 90 wt% saturated compounds, less than or equal to 10 wt% aromatic compounds, and a total of at least 1.7 end group / side group propyl groups and end group / side group ethyl groups per 100 carbon atoms; and the deposit-resistant fluid is configured to remain flowable in a low temperature environment and configured to resist forming deposits in an oxidizing environment, wherein the at least one other base stock comprises a Group I base stock having a kinematic viscosity at 100°C of 12 cSt or less, and wherein the anti-deposit fluid comprises at least 70 wt% and less than 90 wt% saturated compound content and wherein the anti-deposit fluid has an average carbon deposit / sludge rating of 8 to 10 as measured according to ASTM D5704.

21. The anti-deposit fluid of claim 20, wherein the oxidizing environment comprises a temperature of up to 325°F (163°C); and the anti-deposit fluid is an automotive fluid configured to resist the formation of deposits for at least 50 hours in the oxidizing environment.

Images