PAO-based-compositions for lubricant applications

Abstract

Lubricant compositions contain at least 50 wt. % of a low viscosity PAO and 1-20 wt. % of an additive system containing at least an anti-wear additive and a dispersant. The low viscosity PAO can contain at least 90 wt. % hydrogenated 1-dodecene dimer; or can contain at least 90 wt. % C24 alkanes; or can have a 100 ℃ kinematic viscosity of 1.8-3.6 cSt, a 40 ℃ kinematic viscosity of 7-11 cSt, and a flash point of 150-210 ℃; or can have a difference in high pressure viscosity at 826 MPa from 75 °C to 100 °C of 10-40 mPa-s; or can have a difference in high pressure viscosity at 950 MPa from 75 °C to 100 °C of 20-50 mPa-s; or can have a phase transition at 40 ℃ at a pressure from 800 to 1100 MPa in a high pressure viscosity test; or any combination of these attributes.

Description

[0001] P AO-BASED COMPOSITIONS FOR

[0002] LUBRICANT APPLICATIONS

[0003] FIELD OF THE INVENTION

[0004] The present invention relates generally to lubricant compositions for a variety of enduse applications, and more particularly relates to polyalphaolefin (PAO) based lubricant compositions for use in electric vehicle transmissions and other motor vehicle lubricant applications.

[0005] BACKGROUND OF THE INVENTION

[0006] Lubricants are used in automobile and other motor vehicle applications to prevent wear, reduce friction, provide cooling and heat dissipation, and protect against corrosion, amongst other benefits. However, lubricants with improvements in these and other areas are still needed. Accordingly, it would be beneficial to develop and utilize lubricants with improved performance properties, and it is to these ends that the present invention is generally directed.

[0007] SUMMARY OF THE INVENTION

[0008] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify required or essential features of the claimed subject matter. Nor is this summary intended to be used to limit the scope of the claimed subject matter.

[0009] Lubricant compositions are disclosed and described herein. A fluid lubricant composition in one aspect of this invention can comprise (i) at least 50 wt. % of a low viscosity PAO comprising at least 90 wt. % hydrogenated 1-dodecene dimer, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant. A lubricant composition in another aspect of this invention can comprise (i) at least 50 wl. % of a low viscosity PAO comprising at least 90 wt. % C24 alkanes, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant. A lubricant composition in another aspect of this invention can comprise (i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a 100 °C kinematic viscosity in a range from 1.8 to 3.6 cSt, a 40 °C kinematic viscosity in a range from 7 to 11 cSt, and a flash point in a range from 150 to 210 °C. and (ii) from 1 to 20 wt. % of an additive system comprising an antiwear additive and a dispersant. A lubricant composition in yet another aspect of this invention can comprise (i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a difference in high pressure viscosity at 826 MPa from 75 °C to 100 °C in a range from 10 to 40 mPa-s, or a difference in high pressure viscosity at 950 MPa from 75 °C to 100 °C in a range from 20 to 50 rnPa-s, or both, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant. A lubricant composition in still another aspect of this invention can comprise (i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a phase transition at 40 °C at a pressure in a range from 800 to 1100 MPa in a high pressure viscosity test, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

[0010] Beneficially, these and other lubricant compositions encompassed herein can have unexpectedly high transmission efficiency, which can be quantified by an end of test temperature in a PV1454 (ARKL) test that falls within a range from 90 to 98 °C, and more often, from 94 to 97 °C. These values translate to a temperature reduction (AT) versus a standard mineral oil (having an end of test temperature of 133 °C) that range from 35 to 43 °C (correlating to an advantage of 26-32% based on temperature), or more often, from 36 to 39 °C (correlating to an advantage of 27-29% based on temperature).

[0011] While not limited thereto, the lubricant compositions can be utilized in a wide variety of end-use applications, such as transmission fluids, engine oils, axle or gear oils, hydraulic fluids, greases, and the like.

[0012] Both the foregoing summary and the following detailed description provide examples and are explanatory only. Accordingly, the foregoing summary and the following detailed description should not be considered to be restrictive. Further, features or variations can be provided in addition to those set forth herein. For example, certain aspects and embodiments can be directed to various feature combinations and sub-combinations described in the detailed descnption.

[0013] BRIEF DESCRIPTION OF THE FIGURES

[0014] The following figures form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to these figures in combination with the detailed description.

[0015] FIG. 1 is a plot of the Houillon kinematic viscosity versus temperature at atmospheric pressure for the polyalphaolefins (PAOs) of Example 1 and Comparative Examples C2-C4.

[0016] FIGS. 2-5 are plots of the logarithm of viscosity versus pressure at three temperatures for the PAOs of Example 1 and Comparative Examples C2-C4, respectively. FIG. 6 is a schematic diagram of the axial deep groove ball bearing temperature adapter utilized in the PV1454 (ARKL) test.

[0017] FIG. 7 is a bar chart of the end of test temperatures for lubricant compositions containing the PAOs of Example 1 and Comparative Examples C2-C7 in a PV1454 (ARKL) test.

[0018] While the inventions disclosed herein are susceptible to various modifications and alternative forms, only a few specific aspects have been shown by way of example in the drawings and described in detail below. The figures and detailed description of specific aspects are not intended to limit the breadth or scope of the inventive concepts or the appended claims in any manner. Rather, the figures and detailed description are provided to illustrate the inventive concepts to a person of ordinary skill in the art and to enable such person to make and use the inventive concepts.

[0019] DEFINITIONS

[0020] To define more clearly the terms used herein, the following definitions are provided. Unless otherwise indicated, the following definitions are applicable to this disclosure. If a term is used in this disclosure but is not specifically defined herein, the definition from the IUPAC Compendium of Chemical Terminology7, 2ndEd (1997), can be applied, as long as that definition does not conflict with any other disclosure or definition applied herein, or render indefinite or non-enabled any claim to which that definition is applied. To the extent that any definition or usage provided by any document incorporated herein by reference conflicts with the definition or usage provided herein, the definition or usage provided herein controls.

[0021] Herein, features of the subject matter can be described such that, within particular aspects, a combination of different features can be envisioned. For each and every aspect and / or feature disclosed herein, all combinations that do not detrimentally affect the compositions, processes, and / or methods described herein are contemplated with or without explicit description of the particular combination. Additionally, unless explicitly recited otherwise, any aspect and / or feature disclosed herein can be combined to describe inventive compositions, processes, and / or methods consistent with the present disclosure.

[0022] In this disclosure, while compositions, processes, and methods are described in terms of “comprising” various components or steps, the compositions, processes, and methods also can “consist essentially of’ or “consist of’ the various components or steps, unless stated otherwise. The terms “a,” “an,” and “the” are intended to include plural alternatives, e.g., at least one, unless otherwise specified. For instance, the disclosure of "an anti-wear additive” or “a dispersant” is meant to encompass one, or combinations of more than one, anti-wear additive or dispersant, respectively, unless otherwise specified.

[0023] Generally, groups of elements are indicated using the numbering scheme indicated in the version of the periodic table of elements published in Chemical and Engineering News, 63(5), 27, 1985. In some instances, a group of elements can be indicated using a common name assigned to the group; for example, alkali metals for Group 1 elements, alkaline earth metals for Group 2 elements, transition metals for Group 3-12 elements, and halogens or halides for Group 17 elements.

[0024] For any particular compound or group disclosed herein, any name or structure (general or specific) presented is intended to encompass all conformational isomers, regioisomers, stereoisomers, and mixtures thereof that can arise from a particular set of substituents, unless otherwise specified. The name or structure (general or specific) also encompasses all enantiomers, diastereomers, and other optical isomers (if there are any) whether in enantiomeric or racemic forms, as well as mixtures of stereoisomers, as would be recognized by a skilled artisan, unless otherwise specified. For instance, a general reference to pentane includes n-pentane, 2-methyl-butane, and 2,2-dimethylpropane; and a general reference to a buty l group includes a n-butyl group, a sec-butyl group, an iso-butyl group, and a t-butyl group.

[0025] The terms “contacting” and “combining” and the like are used herein to describe compositions, processes, and methods in which the materials or components are contacted or combined together in any order, in any manner, and for any length of time, unless otherwise specified. For example, the materials or components can be blended, mixed, slurried, dissolved, reacted, treated, impregnated, compounded, or otherwise contacted or combined in some other manner or by any suitable method or technique.

[0026] The terms “oligomerization product” and “oligomer product” include all products made by the oligomerization process including the oligomers and products which are not oligomers (e g., polymer). The oligomer product generally refers to a composition prior to hydrogenation. These terms also can be used generically herein to include homo-oligomers, co-oligomers, and so forth.

[0027] A “polyalphaolefin” (PAO) is a mixture of hydrogenated (or alternatively, substantially saturated) oligomers, containing units derived from an alpha olefin monomer. Unless specified otherwise, the PAO can contain units derived from alpha olefin monomer units, which can be the same (hydrogenated or substantially saturated alpha olefin homo- oligomer) or can be different (hydrogenated or substantially saturated alpha olefin cooligomer). Generally, the alpha olefin monomer utilized to produce the polyalphaolefin can be any alpha olefin monomer described herein. One having ordinary skill in the art would recognize that the processes for producing the PAO can leave some hydrogenated monomer in the PAO (e.g., less than 1 wt. % based on the total amount of the PAO), and this quantity of hydrogenated monomer can be specified.

[0028] Several types of ranges are disclosed in the present invention. When a range of any type is disclosed or claimed, the intent is to disclose or claim individually each possible number that such a range could reasonably encompass, including end points of the range as well as any sub-ranges and combinations of sub-ranges encompassed therein. For example, the relative amount of the low viscosity PAO in the lubricant composition can be in various ranges. By a disclosure that a lubricant composition contains at least 50 wt. % of the low viscosity PAO, the intent is to recite that the PAO content can be any amount in the range and, for example, can include any range or combination of ranges from 50 wt. % to less than 100 wt. % low viscosity PAO, such as at least 60 wt. %, at least 70 wt. %, at least 80 wt. %, at least 90 wt. %, from 50 to 99 wt. %, from 50 to 80 wt. %, from 70 to 95 wt. %. from 70 to 85 wt. %, from 80 to 98 wt. %, from 80 to 95 wt. %, or from 80 to 90 wt. % low viscosity PAO, and so forth. Likewise, all other ranges disclosed herein should be interpreted in a manner similar to this example.

[0029] In general, an amount, size, formulation, parameter, range, or other quantity or characteristic is “about” or “approximate” whether or not expressly stated to be such. Whether or not modified by the term “about” or “approximately,” the claims include equivalents to the quantities or characteristics.

[0030] Although any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the typical methods, devices, and materials are herein described.

[0031] All publications and patents mentioned herein are incorporated herein by reference in their entirety for the purpose of describing and disclosing, for example, the constructs and methodologies that are described in the publications and patents, which might be used in connection with the presently described invention.

[0032] DETAILED DESCRIPTION OF THE INVENTION

[0033] Lubricant compositions containing low viscosity PAOs for a variety of end-use applications, such as in electric vehicle transmissions, are disclosed herein. An objective of the present invention is to produce a lubricant composition containing a low viscosity PAO for reducing friction and reducing energy consumption. Another objective is to produce a lubricant composition having the benefits of reduced wear often associated with a higher viscosity fluid in combination with the energy efficiency benefits often associated with a low er viscosity' fluid. This may be attributable, at least in part, to the surprising high pressure viscosity properties of the low viscosity PAO described herein, for example, the liquid PAO undergoing a phase transition to a solid or semi-solid under high pressure conditions.

[0034] Another benefit is to produce a lubricant composition with improved pressure viscosity characteristics resulting in excellent efficiency properties for use as lubricating greases and also lubricating fluids in electric vehicle and conventional combustion engine vehicle lubricant applications, like transmission, gear, hydraulic and cooling systems. These and other benefits are described hereinbelow.

[0035] LUBRICANT COMPOSITIONS

[0036] A first lubricant composition encompassed herein can comprise (or consist essentially of, or consist of) (i) at least 50 wt. % of a low- viscosity polyalphaolefin (PAO) comprising at least 90 wt. % hydrogenated 1 -dodecene dimer, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant. A second lubricant composition can comprise (or consist essentially of, or consist of) (i) at least 50 wt. % of a low viscosity PAO comprising at least 90 wt. % C24 alkanes, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant. A third lubricant composition can comprise (or consist essentially of, or consist of) (i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a 100 °C kinematic viscosity in a range from 1.8 to 3.6 cSt, a 40 °C kinematic viscosity in a range from 7 to 1 1 cSt, and a flash point in a range from 150 to 210 °C, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant. A fourth lubricant composition can comprise (or consist essentially of, or consist of) (i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a difference in high pressure viscosity at 826 MPa from 75 °C to 100 °C in a range from 10 to 40 rnPa-s, or a difference in high pressure viscosity at 950 MPa from 75 °C to 100 °C in a range from 20 to 50 mPa-s, or both, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant. A fifth lubricant composition can comprise (or consist essentially of, or consist of) (i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a phase transition at 40 °C at a pressure in a range from 800 to 1100 MPa in a high pressure viscosity test, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant. These illustrative and non-limiting examples of lubricant compositions consistent with the present invention also can have any of the characteristics or properties listed below and, in any combination, unless indicated otherwise.

[0037] Referring first to the low viscosity polyalphaolefin (PAO) component of the lubricant compositions, the PAO is described as a low viscosity PAO to indicate that the 100 °C kinematic viscosity (KV100) is less than or equal to 5 cSt, and more often, less than or equal to 4 cSt or less than or equal to 3.2 cSt. In an aspect, the PAO can have a 100 °C kinematic viscosity ranging from 1.8 to 3.6 cSt. For instance, the PAO can have a minimum KV100 of 1.8, 2, 2.1. 2.2, or 2.3 cSt; additionally, or alternatively, the maximum KV100 of the PAO can be 3.2, 3, 2.8, 2.7, or 2.6 cSt. Generally, the 100 °C kinematic viscosity’ of the PAO can be in a range from any minimum KV100 disclosed herein to any maximum KV100 disclosed herein. Therefore, suitable non-limiting ranges for the 100 °C kinematic viscosity of the PAO can include the following ranges: from 1.8 to 3.2 cSt, from 2 to 3 cSt, from 2.1 to 2.8 cSt, from 2.2 to 2.7 cSt, or from 2.3 to 2.6 cSt. KV100 is determined in accordance with ASTM D7042-04 or ASTM D445.

[0038] The 40 °C kinematic viscosity (KV40) of the PAO can fall within a range from 7 to 11 cSt. For instance, the PAO can have a minimum KV40 of 7, 7.5, 7.9, or 8 cSt; additionally, or alternatively, the maximum KV40 of the PAO can be 10, 9, or 8.5 cSt. Generally, the 40 °C kinematic viscosity of the PAO can be in a range from any minimum KV40 disclosed herein to any maximum KV40 disclosed herein. Therefore, suitable nonlimiting ranges for the 40 °C kinematic viscosity of the PAO can include the following ranges: from 7 to 10 cSt, from 7 to 9 cSt. from 7.5 to 10 cSt. from 7.5 to 9 cSt, from 7.9 to 9 cSt, or from 8 to 8.5 cSt. KV40 is determined in accordance with ASTM D7042-04 or ASTM D445.

[0039] The flash point of the PAO typically ranges from 150 to 210 °C. For instance, the minimum flash point of the PAO can be 150, 155. 160, 165, or 170 °C; additionally, or alternatively, the maximum flash point can be 210. 205, 200, 195. or 190 °C. Generally, the flash point of the PAO can be in a range from any minimum flash point temperature disclosed herein to any maximum flash point temperature disclosed herein. Therefore, suitable non-limiting ranges for the flash point of the PAO can include the following ranges: from 150 to 210 °C, from 155 to 205 °C, from 155 to 200 °C, from 160 to 205 °C, from 160 to 200 °C, from 165 to 195 °C, or from 170 to 190 °C. The flash point is determined in accordance with ASTM D92.

[0040] The pour point of the PAO in the lubricant compositions typically can fall within a range from -70 to -25 °C. For instance, the minimum pour point of the PAO can be -70, -65, -60, or -55 °C; additionally, or alternatively, the maximum pour point can be -25, -35, -40, or -45 °C. Generally, the pour point of the PAO can be in a range from any minimum pour point temperature disclosed herein to any maximum pour point temperature disclosed herein. Therefore, suitable non-limiting ranges for the pour point of the PAO can include the following ranges: from -70 to -25 °C, from -65 to -35 °C, from -60 to -40 °C, from -60 to -45 °C, from -55 to -40 °C, or from -55 to -45 °C. The pour point is determined in accordance with ASTM D97 or ASTM D5950.

[0041] While not limited thereto, the PAO often has a density at 15.6 °C in a range of from 0.803 to 0.810 g / cc. In an aspect, the PAO can have a minimum density of 0.803, 0.804, 0.8045, 0.805, 0.8055, or 0806 g / cc; additionally, or alternatively, the maximum density of the PAO can be 0.810, 0.809. 0.8085, 0.808. 0.8075, or 0.807 g / cc. Generally, the 15.6 °C density of the PAO can be in a range from any minimum density disclosed herein to any maximum density disclosed herein. Therefore, suitable non-limiting ranges for the density at 15.6 °C of the PAO can include the following ranges: from 0.803 to 0.810 g / cc, from 0.804 to 0.809 g / cc, from 0.8045 to 0.8085 g / cc, from 0.805 to 0.808 g / cc, from 0.8055 to 0.8075 g / cc, from 0.806 to 0.8075 g / cc. or from 0.806 to 0.807 g / cc. Density is determined in accordance with ASTM D4052.

[0042] The low viscosity PAO in the lubricant composition has an unexpectedly high difference in viscosity (Aviscosity) over the 75 °C to 100 °C temperature range, when exposed to high pressures. In one aspect, the PAO can have a difference in high pressure viscosity at 826 MPa from 75 °C to 100 °C in a range from 10 to 40 mPa-s. In an aspect, the minimum difference in viscosity can be 10, 15, 20, or 22 mPa-s; additionally, or alternatively, the maximum difference in viscosity can be 40, 35, 30, or 28 mPa-s. Generally, the Aviscosity of the PAO can be in a range from any minimum Aviscosity at 826 MPa disclosed herein to any maximum Aviscosity at 826 MPa disclosed herein. Therefore, suitable nonlimiting ranges for the Aviscosity at 826 MPa of the PAO can include the following ranges: from 10 to 40 mPa-s, from 10 to 35 mPa-s, from 15 to 40 mPa-s, from 15 to 35 mPa-s, from 15 to 30 mPa-s, from 20 to 35 mPa-s, from 20 to 30 mPa-s, or from 22 to 28 mPa-s. The high viscosity test procedure is described in the example section below. Similarly, the PAO can have a difference in high pressure viscosity' at 950 MPa from 75 °C to 100 °C in a range from 20 to 50 mPa-s. In an aspect, the minimum difference in viscosity can be 20, 25, or 27 mPa-s; additionally, or alternatively, the maximum difference in viscosity' can be 50, 45, 40, 35, or 33 mPa-s. Generally, the Aviscosity of the PAO can be in a range from any minimum Aviscosity at 950 MPa disclosed herein to any maximum Aviscosity at 950 MPa disclosed herein. Therefore, suitable non-limiting ranges for the Aviscosity at 950 MPa of the PAO can include the following ranges: from 20 to 50 mPa-s, from 20 to 45 mPa-s, from 20 to 40 mPa-s, from 25 to 45 mPa-s, from 25 to 40 mPa-s, from 25 to 35 mPa-s, or from 27 to 33 mPa-s.

[0043] Unexpectedly, the low viscosity PAO can exhibit a phase transition in a high pressure viscosity test at 40 °C. For instance, the PAO can have a phase transition at 40 °C at a pressure in a range from 800 to 1100 MPa in a high pressure viscosity test, as described in the example section below. Under these high pressure conditions, the liquid PAO undergoes a transition to a solid or semi-solid state. In one aspect, the phase transition of the PAO at 40 °C can occur at a pressure in a range from 850 to 1100 MPa, while in another aspect, the phase transition can occur at a pressure in a range from 850 to 1050 MPa. and in yet another aspect, the phase transition can occur at a pressure in a range from 900 to 1100 MPa, and in still another aspect, the phase transition can occur at a pressure in a range from 900 to 1050 MPa.

[0044] In a particular aspect of this invention, the low viscosity’ PAO in the lubricant composition can comprise at least 90 wt. % hydrogenated 1 -dodecene dimer. While not being limited thereto, the PAO can comprise at least 92 wt. % or at least 95 wt. % of hydrogenated 1 -dodecene dimer in some aspects, while in other aspects, the PAO can comprise at least 97 wt. % or at least 98 wt. % hydrogenated 1 -dodecene dimer. Thus, for example, the PAO can comprise at least 99 wt. % (or 100 wt. %) hydrogenated 1 -dodecene dimer.

[0045] Stated another way, the low viscosity' PAO can comprise monomer units derived from 1 -dodecene. The repeating units of the PAO can be predominantly 1 -dodecene monomer units. Accordingly, the PAO in the lubricant composition can comprise at least 90 wt. %, and more often, at least 92 wt. %, at least 95 wt. %, at least 97 wt. %, or at least 98 wt. % 1- dodecene monomer units. Thus, for example, the PAO can comprise at least 99 wt. % (or 100 wt. %) 1 -dodecene monomer units. The low viscosity' PAO, in some aspects, can contain less than 8 wt. %. less than 5 wt. %, less than 3 wt. %, or less than 1 wt. % of 1 -decene monomer units. Consistent with aspects of this invention, the lubricant composition can comprise a low viscosity’ PAO that comprises at least 90 wt. % C24 alkanes. In an aspect, the low viscosity PAO can comprise at least 92 wt. % C24 alkanes, at least 95 wt. % C24 alkanes in another aspect, at least 97 wt. % C24 alkanes in another aspect, at least 98 wt. % C24 alkanes in yet another aspect, and at least 99 wt. % C24 alkanes in still another aspect. The low- viscosity PAO. in some aspects, can contain less than 8 wt. %. less than 5 wt. %, less than 3 wt. %, or less than 1 wt. % of C20 alkanes.

[0046] The main component of the lubricant composition is the low viscosity PAO. While not being limited thereto, the lubricant composition ordinarily contains at least 50 wt. % of the low viscosity PAO, and more often, the lubricant composition contains at least 60 wt. %, at least 70 wt. %, at least 80 wt. %. or at least 90 wt. % of the low viscosity PAO. For instance, the low viscosity PAO content of the lubricant composition can range from 50 to 99 wt. %; alternatively, from 50 to 80 wt. %; alternatively, from 70 to 95 wt. %; alternatively, from 70 to 85 wt. %; alternatively, from 80 to 98 wt. %; alternatively, from 80 to 95 wt. %; or alternatively, from 80 to 90 wt. %.

[0047] In addition to the low viscosity PAO. the lubricant composition comprises from 1 to 20 wt. % of an additive system, the additive system comprising an anti-wear additive and a dispersant. Other illustrative and non-limiting ranges for the amount of the additive system in the lubricant composition include from 2 to 18 wt. %, from 3 to 15 wt. %, from 3 to 10 wt. %, from 4 to 15 wt. %. from 4 to 10 wt. %, from 5 to 12 wt. %. or from 6 to 10 wt. %, and the like. The additive system, at a minimum, contains an anti-wear additive (one or more than one) and a dispersant (one or more than one).

[0048] As those skilled in the art would readily recognize, the additive system can contain other additive ingredients or materials in addition to the anti-wear additive and the dispersant, in order to impart specific properties to the lubricant composition, depending of course upon the end-use application for the lubricant composition. For instance, the additive system can further comprise a viscosity- modifier, a friction modifier / reducer, a detergent, a demulsifier, a defoamant, an antioxidant, an extreme pressure agent, a rust / corrosion inhibitor, a metal passivator, a pour point depressant, or a thickener. Any combination of two or more of these ingredients or materials also can be present, and often are present, in the additive system.

[0049] In some aspects, the low- viscosity7PAO and the additive system described herein can be combined with one or more other base oils to form the lubricant composition. Thus, in such aspects, the lubricant composition can contain (i) a low viscosity PAO, (ii) an additive system, and (iii) a base oil. One base oil can be used, or two or more different base oils can be used. Generally, when a base oil is present in the lubricant composition, but not specifically limited thereto, the amount of the base oil (or total base oils, if two or more) in the lubricant composition is in a range from 1 to 45 wt. %; alternatively, from 5 to 40 wt. %; alternatively, from 5 to 25 wt. %; or alternatively, from 10 to 30 wt. %.

[0050] In an aspect, the base oil can be a Group I Base Oil, a Group II Base Oil, a Group III Base Oil. a Group IV Base Oil, or a Group V Base Oil, as well as any combination thereof. These base oil groups are those as designated by The American Petroleum Institute (API). In another aspect, the base oil can be a second polyalphaolefin (i.e., a polyalphaolefin different from the low viscosity PAO described herein), a GTL fluid, or a combination thereof. Additional information on GTL fluids that optionally can be used in the lubricant compositions disclosed herein can be found in “GTL - an emerging route to clean fuels and products,” Hydrocarbon Asia, Nov / Dec 2003, p. 44-49; “Shell gas-to-liquid (GTL) base oil converting natural gas to base oils for lubricants,” Shell Lubricants; and “The Shell GTL Process: Towards a World Scale Project in Qatar: the Pearl Project,” DGMK-Conference, Synthesis Gas Chemistry, October 4-6, 2006, Dresden.

[0051] Unexpectedly, the disclosed lubricant compositions have excellent transmission efficiencies. For example, the disclosed compositions can have a transmission efficiency characterized by an end of test temperature in a PV1454 (ARKL) test that falls within a range from 90 to 98 °C. In one aspect, the end of test temperature can range from 93 to 98 °C, while in another aspect, the end of test temperature can range from 94 to 98 °C, and in another aspect, the end of test temperature can range from 94 to 97 °C, and in yet another aspect, the end of test temperature can range from 95 to 98 °C, and in still another aspect, the end of test temperature can range from 95 to 97 °C. Additionally, or alternatively, the surprisingly low end of test temperatures can be compared versus a standard mineral oil (having an end of test temperature of 133 °C). Thus, for the disclosed lubricant compositions, temperature reductions (AT) versus the standard mineral oil can fall within a range from 35 to 43 °C. In one aspect, the AT can range from 35 to 40 °C, while in another aspect, the AT can range from 35 to 39 °C, and in another aspect, the AT can range from 36 to 39 °C. and in yet another aspect, the AT can range from 35 to 38 °C, and in still another aspect, the AT can range from 36 to 38 °C. While not wishing to be bound by theory, it is believed that (i) a lower end of test temperature and (ii) a larger AT versus a standard mineral oil control translate to improved transmission efficiency, reduced energy requirements, and an increased range of a vehicle powered by an electric motor. Referring now to additives that can be present in the additive system of the disclosed lubricant compositions, general information on additives that can be used herein can be found in '‘Lubricants and Lubrications,” T. Mang and W. Dresel, eds., Wiley-VCH GmbH, Weinheim (2001); “Lubrication Fundamentals,” Second Edition, Revised and Expanded, ExxonMobil Lubricants and Specialties, D.M. Pirro, A. A. Wessol, CRC Press 2001; “Fuels and Lubricants Handbook: Technology’, Properties, Performance, and Testing" edited by George E. Totten, Steven R. Westbrook, Rajesh J. Shah. ASTM (2003). ISBN 0-8031-2096- 6; Chapter 9 Additives and Additive Chemistry, pp. 199-248, “Lubricants and Related Products,” Klamann, Verlag Chemie, Deerfield Beach, FL, ISBN 0-89573-177-0; “Lubricant Additives” by M. W. Ranney, published by Noyes Data Corporation of Parkridge, N.J. (1973); and “Lubricant Additives,” C. V. Smallheer and R. K. Smith, published by the Lezius-Hiles Co. of Cleveland, OH (1967).

[0052] Additive types which can be included in a lubricant composition can include, but are not limited to, viscosity index improvers / viscosity modifiers / viscosity improvers, dispersants (metallic and / or non-metallic), detergents (metallic and / or non-metallic), friction modifiers, traction improving additives, demulsifiers, defoamants, antioxidants, anti-wear additives (metallic and non-metallic, phosphorus-containing and non-phosphorus, sulfur-containing and non-sulfur types), extreme-pressure additives (metallic and non-metallic, phosphorus- containing and non-phosphorus. sulfur-containing and non-sulfur types), anti-rust additives, corrosion inhibitors, metal deactivators, anti-seizure agents, pour point depressants, wax modifiers, seal compatibility’ agents, friction modifiers, lubricity agents, anti-staining agents, chromophores (dyes), and / or haze inhibitors.

[0053] Viscosity index improvers (also known as viscosity modifiers and viscosity improvers) can provide lubricant compositions with high and low temperature operability. These additives can impart shear stability at elevated temperatures and acceptable viscosity at low temperatures. Suitable viscosity’ index improvers can include high molecular weight hydrocarbons, olefin polymers and copolymers, polyesters, and viscosity index improver dispersants that function as both a viscosity index improver and a dispersant. Viscosity index improvers can have molecular weights ranging from 10,000 Da to 1,000.000 Da. from 20.000 Da to 500,000 Da, or from 50,000 Da to 200,000 Da.

[0054] Viscosity index improvers can include polymers and copolymers of methacrylate, butadiene, olefins, or alkylated styrenes. Exemplary viscosity index improvers include, but are not limited to, polyisobutylene, copolymers of ethylene and propylene, hydrogenated block copolymers of styrene and isoprene, polyacrylates (e.g., polymers and / or copolymers of various chain length acry lates), and polymethacrylates (e.g., polymers and / or copolymers of various chain length alkyl methacrylates). Generally, the viscosity index improver can be used in an amount of from 0.01 wt. % to 6 wt. %, from 0.01 to 5 wt. %, or from 0.01 to 4 wt. %, based upon the total weight of the lubricant composition.

[0055] Dispersants are additives utilized to maintain oxidation products (produced during use of the lubricant composition) in suspension in the lubricant compositions to prevent the accumulation of debris that could score bearings, block lubricant pathways, prevent deposit formations, inhibit corrosive wear by neutralizing acidic products (e.g., combustion products), and other types of damage. Dispersants can be ash-containing or ashless in character. Dispersants can include, but are not limited to, alkenylsuccinic acid or anhydride derivatives (e.g., succinimides, succinate esters, or succinate ester amides), phenates, Mannich-Base condensates (e.g., the condensation products of alkylphenols, amines and aldehydes), hydrocarbyl substituted amines, sulfonates, sulfurized phenates, salicylates, naphthenates, stearates, carbamates, thiocarbamates, and phosphorus derivatives in metallic and non-metallic versions. Suitable dispersants can contain a polar group attached to a relatively high molecular weight hydrocarbon chain where the polar group contains at least one element of nitrogen, oxygen, or phosphorus. Patents describing dispersants which can be utilized in the lubricant compositions include, but are not limited to, U.S. Patent Nos. 3,036,003; 3,087,936; 3,172,892; 3,200,107; 3,219,666; 3,254,025,; 3.272,746; 3,275,554;

[0056] 3,322,670; 3,329,658; 3,316,177; 3,438.757; 3,341.542; 3.413,347; 3.438,757; 3,444,170;

[0057] 3,449,250; 3,454,555; 3,454,607; 3,519,565; 3,541 ,012; 3,565,804; 3,630,904; 3,632,51 1 ;

[0058] 3,652,616; 3,666,730; 3,687,849; 3,697,574; 3,702,300; 3,703,536; 3,704,308; 3,725,277;

[0059] 3,725,480; 3,726,882; 3,751,365; 3,755,433; 3,756,953; 3,787,374; 3,798,165; 3,803,039;

[0060] 3,822,209; 3,948.800; 4,100,082; 4,234,435; 4,426,305; 4,454,059; 4,767,551; and 5,705,458, among others. Generally, dispersants can be used in an amount from 0.1 wt. % to 18 wt. %, 0. 1 wt. % to 15 wt. %, or 0.1 wt. % to 8 wt. %, based upon the total weight of the lubricant composition.

[0061] Detergents are additives utilized to maintain overall cleanliness by keeping sludge, carbon and deposit precursors suspended in the lubricant compositions. Many detergents are chemically similar to dispersants. Detergents which can be utilized in the lubricant compositions can include the alkali or alkaline earth metal of sulfates, sulfonates, phenates, carboxylates, phosphates, carboxylic acids, and salicylates. For example, suitable detergents can include, but are not limited to, the sulfonated alkylaromatic hydrocarbons, alkyl phenols, sulfurized alkyl phenols treated with an alkaline earth metal hydroxide or oxide (e.g., CaO, Ca(OH)2. BaO, Ba(OH)2, MgO, or Mg(OH)2). Sulfonated alkylaromatic compounds can be prepared from sulfonic acids obtained by sulfonation of C9 to Cso (or Ce to Ceo) alkyl substituted aromatic hydrocarbons (having one or more than one alkyl groups) where the alkyl groups independently can be C3 to C70 alkyl groups and the aromatic portion can be benzene, toluene, xylene, naphthalene, or biphenyl. Alkyl phenol and / or sulfurized alkyl phenols can have one or more C4 to C30 alkyl groups. The detergents utilized in the lubricant compositions can be neutral (i.e.. produced using only enough alkali or alkaline earth compound to neutralize the sulfonated alkylaromatic compound, alkyl phenol, or sulfurized alkyl phenol) or can be overbased (i.e., produced using more alkali or alkaline earth compound than necessary to neutralize the sulfonated alkylaromatic compound, alkyl phenol, or sulfurized alkyl phenol). Generally, detergents can be used in an amount from 0.01 wt. % to 6.0 wt. %, 0.05 wt. % to 5.0 wt. %, or 0.1 to 4 wt. %, based upon the total weight of the lubricant composition.

[0062] Defoamants (or anti-foam agents) are additives utilized to retard the formation of stable foam in the lubricant compositions. Defoamants which can be utilized in the lubricant compositions can include, but are not limited to, silicone compounds (e.g.. polysiloxanes, such as silicon oil or polydimethyl siloxane, among others) and organic polymers. Defoamants can be utilized in conjunction with demulsifiers. Generally, the maximum amount of defoamants can be 1 wt. %. 0.5 wt. %, or 0.1 wt. %, based upon the total weight of the lubricant composition.

[0063] Antioxidants are additives utilized to retard the oxidative degradation of the PAOs or other base oils in the lubricant compositions. Oxidative degradation can produce deposits on metal surfaces, sludge, and / or increase the viscosity of the lubricant composition. Antioxidants which can be utilized in the lubricant compositions include, but are not limited to, hindered phenols (ashless); neutral or basic metal salts of hindered phenols; hindered phenolic carboxylic acid (e.g., propionic acid) ester derivatives; bis-hindered phenols; alkylated and non-alkylated aromatic amines; sulfurized alkyl phenols; alkali or alkaline earth metal salts of sulfurized alkyl phenols; copper dihydrocarbyl thio or dithio-phosphates; copper salts of carboxylic acids (natural or synthetic); and copper salts of dithiacarbamates, dithiocarbamates, sulphonates, phenates, acetylacetonates and alkenyl succinic acids or anhydrides (neutral, basic or acidic). Patents describing antioxidants which can be utilized in the lubricant compositions include, but are not limited to, U.S. Patent Nos. 4,798,684 and 5,084,197. Generally, the antioxidants can be used in an amount from 0.01 wt. % to 5 wt. %, from 0.01 to 2.5 wt. %, or from 0.01 wt. % to 1.5 wt. %, based upon the total weight of the lubricant composition.

[0064] Anti-wear additives and extreme pressure additives are compounds utilized to reduce friction and wear of metal parts. Anti-wear additives and extreme pressure additives which can be utilized in the lubricant compositions include, but are not limited to, metal alkylthiophosphates (e g., a zinc alkylthiophosphonate having a Ci to Cis alkyl group), metal dialkyldithiophosphates (e.g., a zinc alkylthiophosphonate having Ci to Cis alkyl groups), sulfurized C3 to C30 aliphatic or arylaliphatic hydrocarbon olefins (acyclic or cyclic), polysulfides of thiophosphorus acids, polysulfides of thiophosphorus acid esters, phosphorothionyl disulfides, alkylthiocarbamoyl compounds (e g-, bis(dibutyl)thiocarbamoyl) in combination with a molybdenum compound (e.g., oxymolybdenum diisopropylphosphorodithioate sulfide) and a phosphorus ester (e.g., dibutyl hydrogen phosphite, for example), thiocarbamates, thiocarbamate / molybdenum complexes (e.g., moly-sulfur alkyl dithiocarbamate trimer complexes), and / or glycerol ester (e.g., mono- , di-, and tri-oleates, mono-palmitates and mono-myristates). Patents describing anti-wear additives and / or extreme pressure additives which can be utilized in the lubricant compositions include, but are not limited to, U.S. Patent Nos. 2,443,264; 2,471,115; 2,526,497; 2,591,577; 3,770,854; 4,501,678; 4,941,984; 5,034,141; 5,034,142; 5,084,197; and 5,693,598. Generally, the total amount of anti-wear additives and extreme pressure additives used in the lubricant compositions can be from 0.01 wt. % to 8 wt. %. from 0.01 to 5 wt. %, or from 0.01 wt. % to 4 wt. %, based upon the total weight of the composition. In an aspect, the anti-wear additive is in most cases phosphorus-based.

[0065] Anti-rust additives are additives that protect lubricated metal surfaces against chemical attack by water or other contaminants. Anti-rust additives can function by 1) wetting the metal surface with a film of oil, 2) absorbing water into a water-in-oil emulsion, and / or 3) adhering to the metal to form a non-reactive surface, among other potential modes of function. Anti-rust additives which can be utilized in the lubricant compositions include, but are not limited to, zinc dithiophosphates, metal phenolates, basic metal sulfonates, fatty acids, and amines. Generally, the amount of anti-rust additives used in the lubricant compositions can be from 0.01 wt. % to 5 wt. %, from 0.01 wt. % to 2.5 wt. %, or from 0.01 wt. % to 1.5 wt. %, based upon the total w eight of the composition.

[0066] Corrosion inhibitors are additives that reduce the degradation of metallic parts that are in contact with the lubricant compositions. Corrosion inhibitors which can be utilized in the lubricant compositions include, but are not limited to, thiadiazoles and triazoles. Patents describing corrosion inhibitors which can be utilized in the lubricant compositions include, but are not limited to, U.S. Patent Nos. 2.719,125; 2.719,126; and 3.087,932. Generally, the amount of corrosion inhibitors used in the lubricant compositions can be from 0.01 wt. % to 5 wt. %, from 0.01 wt. % to 2.5 wt. %, or from 0.01 wt. % to 1.5 wt. %, based upon the total weight of the composition. The corrosion inhibitors also can improve anti-wear and EP properties.

[0067] Pour point depressants are additives that reduce the minimum temperature at which the lubricant compositions will flow or can be poured. Pour point depressants which can be utilized in the lubricant compositions include, but are not limited to, polymethacrylates, polyacrylates, polyarylamides, condensation products of haloparaffm waxes and aromatic compounds, vinyl carboxylate polymers, and terpolymers of dialkylfumarates, vinyl esters of fatty acids and allyl vinyl ethers. Patents describing pour point depressants which can be utilized in the lubricant compositions include, but are not limited to, U.S. Patent Nos. 1,815,022; 2,015,748; 2,191,498; 2,387,501; 2,655,479; 2,666,746; 2,721,877; 2,721,878; and 3,250,715. Generally, the amount of the pour point depressant used in the lubricant compositions can be from 0.01 wt. % to 5 wt. %. from 0.01 wt. % to 2.5 wt. %. or from 0.01 wt. % to 1.5 wt. %, based upon the total weight of the composition.

[0068] Seal compatibility additives are compounds that swell elastomeric seals and can function by causing a chemical reaction in the fluid or a physical change in the seal elastomer. Seal compatibility additives which can be utilized in the lubricant compositions include, but are not limited to, organic phosphates, aromatic esters, aromatic hydrocarbons, esters (e.g., butylbenzyl phthalate), and polybutenyl succinic anhydride. Generally, the amount of the seal compatibility additive used in the lubricant composition can be from 0.01 wt. % to 3 wt. %, from 0.01 wt. % to 2.5 wt. %, or from 0.01 wt. % to 2 wt. %, based upon the total weight of the composition.

[0069] The lubricant compositions disclosed herein can be used in a variety' of formulations or products for a diverse range of applications and industries. While not limited thereto, the lubricant compositions can be utilized in transmission or drive train fluids, which is inclusive of fluids or lubricants for transmissions (e.g.. automobile and truck / bus manual / clutch transmissions and automatic transmissions, farm machinery transmissions), gear boxes (e.g., automobile and truck / bus gears, farm machinery gears), axle assemblies (e.g., transaxles, drive axles), differentials, as well as related hydraulic fluids (e g., for farm equipment and construction vehicles); engine oils (e.g., for internal combustion engines such as gasoline or diesel or hybrid engines) in automobiles, trucks / busses, farm equipment, aircraft, and so forth; and greases (e.g., for any vehicle application such as automobiles, trucks / busses, farm equipment, aircraft).

[0070] Thus, in one aspect, a transmission or drive train fluid formulation can comprise any of the lubricant compositions disclosed herein. Representative hydraulic fluid formulations are discussed in EP 0812902 A2, US 4,783,274, EP 3172294 Bl, and WO 01 / 04240 Al (biodegradable hydraulic fluids), and such formulations can contain from 85 to 99.5 wt. % base oil (e.g., low viscosity PAO), 0.1 to 1.5 wt. % anti-wear additive. 0.1 to 2 wt. % antioxidant and rust / corrosion inhibitor, and optionally a defoamant, although not being limited thereto. Note that hydraulic fluid formulations do not require a dispersant, therefore, these hydraulic fluid formulations can contain at least 50 wt. % of the low viscosity PAO described herein and from 1 to 20 wt. % of an additive system, in which the additive system comprises at least an anti-wear additive (but no dispersant is required to be present in the additive system).

[0071] In another aspect, an engine oil formulation can comprise any of the lubricant compositions disclosed herein. While not limited thereto, an illustrative engine oil formulation can contain 60 to 90 wt. % base oil (e.g., low viscosity PAO) and from 5 to 25 wt. % of an additive system, of which 5 to 15 wt. %, based on the total formulation, can be a viscosity7modifier. Also present in the additive system can be an ashless dispersant often at 6 to 7 wt. %, a metal detergent often at 2 to 4 wt. %, zinc dialkyldithiophosphate (ZDDP) often at 0.5 to 1.5 wt. %. and a rust / corrosion inhibitor often at 0.5 to 2 wt. %. These weight percentages are based on the total engine oil formulation. Typical engine oil formulations are disclosed in, for instance, EP 3452566 Bl, US 6,313,077 Bl, US 6,774,091 B2, US 9029304 B2, WO 2002 / 083826 Al, and CA 2158627 Al. Low SAPS (sulphated ash, phosphorus and sulfur) engine oil formulations are provided in CA 2518323, CA 2547436 C. and EP 2626405 Bl.

[0072] In yet another aspect, a grease formulation can comprise any of the lubricant compositions disclosed herein. A grease can considered herein to be a lubricant that has been thickened such that it maintains its original position and does not readily flow under gravity (e.g.. a semi-solid). Thus, the lubricant compositions disclosed herein can be used as the base for a grease formulation. Various thickener types then can be utilized to prepare the grease formulation, such as alkali metal or alkaline earth metal soaps, urea, polymers, pigments / clays, and the like. Greases can be utilized in a multitude of different end-uses in, for instance, bearings (e.g., wheel bearings), joints, locks and hinges, shock absorbers, gears, and linkages, while not limited thereto. Additional information on greases for vehicle applications can be found in “Introduction to Greases,’" NLGI basic course 2103; “Automotive Greases,” NLGI basic course 2013; “Automotive Greases,” NLGI basic grease course 2003; “Lubricating Greases: Physical and Performance Tests,” Mobil Technical Bulletin, 1988; “The Chemistry of Soap Based Greases,” 70thNLGI Annual Meeting, Hilton Head, 31stBasic Grease Education Course, 2003; and “Additives for Grease,” 70thNLGI Annual Meeting, Hilton Head, Grease Education Course, 2003.

[0073] A representative and non-limiting lubricating grease formulation for drive shafts (e.g., constant velocity joints, sliding joints) can contain 60 to 90 wt. % base oil (e.g., low viscosity PAO), 7 to 17 wt. % thickener (e.g.. lithium complex, poly urea), 1.5 to 5 wt. % solid lubricants (Z.B.M0S2, carbon black, etc.) or 1 to 3 wt. % MoDTC. and 2 to 5 wt. % other additives (e.g., extreme pressure, anti-wear, friction modifier, antioxidant, and so forth). Typical lubricating grease formulations are disclosed in EP 0508115 Al and EP 0580331 Al, typical lithium complex grease formulations are disclosed in US 4,410,435, EP 0958338 Bl, and US 2011 / 0183877 Al, and typical polyurea grease formulations are disclosed in US 5,238,589 A and EP 0761806 BL

[0074] CATALYST SYSTEMS AND OLIGOMERIZATION PROCESSES

[0075] Low viscosity PAOs consistent with aspects of this invention can be produced using any suitable catalyst system. Illustrative examples of catalyst systems that can be used to produce low viscosity PAOs can contain BF3; an alkylaluminum, an alkylaluminum halide, an aluminum trihalide, or any combination thereof; a supported metal oxide; an acidic ionic liquid; a metallocene compound; a clay, an acidic clay, or an acid washed clay; or an acidic ion exchange resin. Representative catalysts are described, for instance, in US 2020 / 0207682 AL

[0076] A representative process that can be used to produce the low- viscosity’ PAO can comprise contacting an olefin feedstock comprising at least 98 wt. % C12 olefins (e.g., 94-95 wt. % 1 -dodecene) with a suitable catalyst system under oligomerization conditions to form an oligomer product, isolating a 1 -dodecene dimer product from the oligomer product using one or more separation steps, and hydrogenating the 1-dodecene dimer product to produce the low' viscosity PAO. Unreacted 1-dodecene monomer can also be isolated and recycled.

[0077] Any suitable oligomerization temperature, oligomerization reaction pressure, hydrogen partial pressure (if used), oligomerization reactor vessel (or vessels), catalyst deactivation technique, separation techniques (e.g., flashing, distillation, etc.), and hydrogenation process and catalyst can be utilized. These are exemplified in representative US patents 4,045,507 and 4,436.947.

[0078] EXAMPLES

[0079] The invention is further illustrated by the following examples, which are not to be construed in any way as imposing limitations to the scope of this invention. Various other aspects, embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to one of ordinary skill in the art without departing from the spirit of the present invention or the scope of the appended claims.

[0080] Kinematic viscosities at 100 °C and 40 °C were determined in accordance with ASTM D7042-04 (Stabinger viscometer method) or ASTM D445 (capillary tube method) at the respective temperatures, and the results are reported in centistokes (cSt). The viscosity index was determined in accordance with ASTM D2270-10el, using the tables provided therein for viscosity data determined at 100 °C and 40 °C. Pour point is a measurement of the temperature at which the sample will begin to flow under carefully controlled conditions. Pour point was determined in accordance with ASTM D97-04 or ASTM D5950 (automatic tilt method), and the results are reported in °C. The flash point was determined in accordance with ASTM D92, and the results are reported in °C. Density was determined in accordance with ASTM D4052.

[0081] Example 1 was a hydrogenated 1 -dodecene dimer containing approximately 95-98 wt. % 1 -dodecene dimer (and approximately 95-98 wt. % C24 alkanes). Example 1 was a nominal 2.5 cSt (KV100) PAO with the properties listed in Table 1.

[0082] Table 1

[0083] Comparative Example 2 (C2) was a nominal 2 cSt (KV100) PAO based on 1 -decene, Comparative Example 3 (C3) was a nominal 2.2 cSt (KV100) PAO prepared by mixing 64 wt. % PAO 2 with 36 wt. % PAO 5, and Comparative Example 4 (C4) was a nominal 4 cSt (KV100) PAO. Examples 1 and C2-C4 were analyzed using different viscosity procedures, as summarized in Table 2. Table 2

[0084] Two Houillon viscometers (1 atm pressure, 40 °C and 100 °C temperature baths) and an ultra-high-pressure viscometer were utilized for the testing in Table 2. The test procedure included three measurements per temperature on the Houillon viscometer and three measurements per temperature and pressure on the ultra-high-pressure viscometer. The Houillon viscosity values at 75 °C were estimated once the other two values were obtained via ASTM D341.

[0085] At atmospheric pressure. FIG. 1 summarizes the Houillon kinematic viscosity values as a function of temperature for the polyalphaolefins (PAOs) of Example 1 and Comparative Examples C2-C4. C4 had the highest viscosity, while C2 had the lowest viscosity. The viscosities of Example 1 and C3 had very similar viscosities at each temperature.

[0086] The ultra-high-pressure viscometer test utilized the procedure described by Bair (Bair S, Qureshi F., Accurate Measurements of Pressure-Viscosity Behavior in Lubricants, doi: 10.1080 / 10402000208982564 2008, 45, 390-6. doi: 10.1080 / 10402000208982564; and Bair S., Pressure-viscosity behavior of lubricants to 1.4 GPa and its relation to EHD traction. Tribology Transactions 2000, 43, 91-9. doi: 10.1080 / 10402000008982317). The ultra-high pressure type of viscometer employs a cylindrical sinker, which can have vanous shapes, equipped with guiding on both ends. The sinker falls within a closely fitting cylindrical bore. This viscometer operates on the principle of Stokes flow, which links the dynamic viscosity of the sample to the velocity of the sinker as it falls under the influence of gravity. The velocity of the sinker is inversely proportional to the viscosity of the sample. The velocity-viscosity relationship was established through calibration tests conducted on a standard fluid. The internationally recognized standard reference for viscosity is water, which has a viscosity of 0.001002 ± 0.0000025 Pa s at a temperature of 20 °C and pressure of 0.101325 MPa. A linear variable differential transformer (LVDT) was used to monitor the location of the sinker in the viscometer chamber. The non-magnetic cylindrical wall surrounding the sinker was plugged at one end and featured a volume-controlling piston at the other. The tube, sinker, plug, and piston together formed the viscometer cartridge, which can be removed from the vessel for the exchange of specimens and sinkers. The sinker in the ultra-high pressure viscometer had a hollow shape, which increased the falling velocity. The relationships between geometry, viscosity, density, and falling velocity were analytically determined. However, in all applications, the relationship between the falling velocity and the viscosity were corroborated through experimental calibration using reference fluids. The maximum pressure achieved was 1.2 GPa with an error of ± 20 MPa using marked divisions on a large analogue gauge in the low-pressure side.

[0087] FIGS. 2-5 illustrate the logarithm of viscosity versus pressure at three temperatures for the PAOs of Example 1 and Comparative Examples C2-C4, respectively. Likewise, Tables 3-6 summarizes the viscosity values at each temperature and pressure for the PAOs of Example 1 and Comparative Examples C2-C4, respectively. From these figures and tables, it is apparent that C2 had the lowest viscosity values and that, generally, viscosity increased with increasing pressure and with decreasing temperature. However, and unexpectedly, for Example 1, once the pressure reached 455, 800, and 1074 MPa for 40, 75 and 100 °C, respectively, the viscosity increased dramatically, suggesting that the PAO fluid of Example 1 was experiencing a transformation at the higher pressures. It was also seen that if Example 1 was left to "relax" for 3 min, the viscosity values decreased and then followed the exponential trend observed for the comparative PAOs.

[0088] From FIG. 2 and Table 3, as the pressure increased at 40 °C. it was observed that the PAO of Example 1 unexpectedly exhibited a phase transition. Further, the dramatic increase in viscosity with pressure, as shown in Table 3, resulted in a difference in high pressure viscosity at 826 MPa from 75 °C to 100 °C of over 25 mPa-s, and the difference in high pressure viscosity at 950 MPa from 75 °C to 100 °C was over 30 mPa-s. While not wishing to be bound by theory, it is believed that the pressure-viscosity behavior of Example 1, in which it acts like a liquid at low pressure and as a solid / semi-solid at high pressure, is beneficial for many lubricant applications. For instance, low viscosity liquid behavior is important for energy efficiency, while high viscosity solid / semi-solid behavior is important for wear protection, such as for intermeshing gears or for any metal surfaces that contact one another. Table 3 - Example 1

[0089] Table 4 - Comparative Example C2

[0090] Table 5 - Comparative Example C3 Table 6 - Comparative Example C4

[0091] The PV1454 (ARKL) test is designed to test the temperature development of a lubricating oil in an axial deep groove ball bearing temperature adapter. The end of test temperature (EOTT) in the PV1454 (ARKL) test is a predictor of transmission efficiency and a measure of the lubricant's ability to control energy losses (e.g., S. Yang, T. Reddyhoff and H. Spikes, ‘‘Influence of Lubricant Properties on ARKL Temperature Rise and Transmission Efficiency”, Trib. Trans. 56: 1119-1136, 2013; J. Zhang, A. Tan and H. Spikes, “Effect of Base Oil Structure on Elastohydrodynamic Friction”, Trib. Lett., 65: 13. 2017).

[0092] The PV1454 method is used to determine the steady-state temperature of lubricating oils in a Shell four-ball apparatus in the axial deep groove ball bearing (ARKL) in accordance with DIN 51350-1. In general, the lubricating oil is tested in an axial deep groove ball bearing (number 51208) which is driven by the Shell four-ball apparatus in accordance with DIN 51350-1. The axial deep groove ball bearing runs according to the splash lubrication method in 38 mL of the lubricating oil to be tested at a constant speed of 4,000 min'1and a constant load of 5,000 N for 120 min in a housing made of a material with low thermal conductivity. The steady-state temperature (often referred to as the end of test temperature, EOTT) in the oil sump is evaluated in relation to an ambient temperature of 30 °C.

[0093] FIG. 6 illustrates the design of the axial deep groove ball bearing temperature adapter utilized in the PV1454 (ARKL) test. In FIG. 6, the components are Spindle insert 1, Holder 2, Insert 3, Clamping nut 4 (polyether ether ketone, PEEK), Base body 5, Lower part 6 (PEEK), Tip 8, Key 9 (not shown), Tip 10, ARKL 11, Screw plug 13, O-ring 14, Sealing ring 15, Cone washer 16, Countersunk screw 17, Cheese head screw 18, Cheese head screw 19, Spring washer 20, Compression fitting 22, and Temperature sensor 23.

[0094] Before starting the test, the axial deep groove ball bearing temperature adapter and the axial deep groove ball bearing were cleaned with a suitable solvent and then dried. The axial deep groove ball bearing temperature adapter was set to 23 °C (+ / - 5 °C) before starting the test. The lower housing washer 11 with the cage 11 and the holder 2 with the upper housing washer 11 of the axial deep groove ball bearing were inserted into the cleaned base body 5 and screwed hand-tight with the clamping nut 4. The density of the lubricating oil was determined at room temperature of the test chamber. The lubricating oil to be tested was filled into the prepared axial deep groove ball bearing temperature adapter through the filling opening and sealed with the screw plug 13. The axial deep groove ball bearing temperature adapter prepared in this way was inserted into the Shell four-ball apparatus using the spindle insert 1 in accordance with DIN 51350-1 and the load of 5,000 N was applied. A thermocouple was connected. The test conditions were a motor speed of 4,000 (+ / - 20) min’1, a lubricating oil quantity of 38 mL (+ / - 0.01 g). a load of 5,000 (+ / - 5) N, and a test duration of 120 (+ / - 1) min. The engine was started, and the test was performed for 120 min. The temperature development in the oil sump of the axial deep groove ball bearing temperature adapter was calculated according to Tsteady = 30 °C - Tambient + TSumP, plotted over test time, and the steady-state temperature (EOTT) was read off.

[0095] Each sample was tested at least 5 times. The resulting steady -state temperatures (EOTTs) were averaged, and any outliers were eliminated. A measurement was defined as an outlier if it deviated by more than 1.5% from the mean value of the measurement series. Outlier measurements were repeated. A reference oil (FVA reference oil no. 2, which is a mineral oil with a KV100 of 5.5 cSt, with 4 wt. % Anglamol 99) also was tested (see DIN 51750-1 and DIN 51750-2). The reference mineral oil had an EOTT of 133 °C.

[0096] FIG. 7 is a bar chart summarizing the end of test temperatures for lubricant compositions containing Example 1 and Comparative Examples C2-C7 in a PV1454 (ARKL) test. Comparative Example 5 (C5) was a nominal 5 cSt (KV100) PAO, Comparative Example 6 (C6) was a nominal 6 cSt (KV100) PAO based on 1 -decene, and Comparative Example 7 (C7) was a nominal 6 cSt (KV100) PAO with a high viscosity index based on 1- dodecene.

[0097] Lubricant compositions contained 91.2 wt. % of the PAOs of Example 1 and Comparative Examples C2-C7 and 8.8 wt. % of an additive system. As shown in FIG. 7, and unexpectedly, the lubricant composition of Example 1 exhibited the lowest EOTT of 96 °C. and surprisingly, the EOTT for this lubricant composition was 3 °C lower than the similar lubricant compositions containing the PAOs of C2-C3, which both had lower KV100 values than that of Example 1. Likewise, the AT versus the 5.5 cSt mineral oil standard having an EOTT of 133 °C for the lubricant composition of Example 1 was 37 °C. the largest of any lubricant compositions. While not wishing to be bound by theory, it is believed that a lower EOTT and a higher AT (versus the mineral oil standard) translate to improved transmission efficiency, reduced energy requirements, and an increased range of a vehicle powered by an electric motor.

[0098] The invention is described above with reference to numerous aspects and embodiments, and specific examples. Many variations will suggest themselves to those skilled in the art in light of the above detailed description. All such obvious variations are within the full intended scope of the appended claims. Other aspects of the invention can include, but are not limited to, the following (aspects are described as “comprising” but alternatively, can “consist essentially of’ or “consist of’):

[0099] Aspect 1. A lubricant composition comprising (i) at least 50 wt. % of a low viscosity PAO comprising at least 90 wt. % hydrogenated 1 -dodecene dimer, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

[0100] Aspect 2. A lubricant composition comprising (i) at least 50 wt. % of a low viscosity PAO comprising at least 90 wt. % C24 alkanes, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

[0101] Aspect 3. A lubricant composition comprising (i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a 100 °C kinematic viscosity in a range from 1.8 to 3.6 cSt, a 40 °C kinematic viscosity in a range from 7 to 11 cSt, and a flash point in a range from 150 to 210 °C, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

[0102] Aspect 4. A lubricant composition comprising (i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a difference in high pressure viscosity at 826 MPa from 75 °C to 100 °C in a range from 10 to 40 mPa-s, or a difference in high pressure viscosity at 950 MPa from 75 °C to 100 °C in a range from 20 to 50 mPa-s, or both, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

[0103] Aspect 5. A lubricant composition comprising (i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a phase transition at 40 °C at a pressure in a range from 800 to 1100 MPa in a high pressure viscosity test, and (ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

[0104] Aspect 6. The composition defined in any one of the preceding aspects, wherein the additive system further comprises a viscosity' modifier, a friction modifier / reducer, a detergent, a demulsifier, a defoamant, an antioxidant, an extreme pressure agent, a rust / corrosion inhibitor, a metal passivator, a pour point depressant, a thickener, or any combination thereof. Aspect 7. The composition defined in any one of the preceding aspects, wherein the composition further comprise any amount disclosed herein, e.g., from 1 to 45 wt. %, from 5 to 40 wt. %, from 5 to 25 wt. %, or from 10 to 30 wt. %, of (iii) a base oil.

[0105] Aspect 8. The composition defined in aspect 7, wherein the base oil comprises a Group I Base Oil, a Group II Base Oil, a Group III Base Oil, a Group IV Base Oil, a Group V Base Oil. or any combination thereof.

[0106] Aspect 9. The composition defined in aspect 7 or 8, wherein the base oil comprises a second polyalphaolefin, a GTL fluid, or a combination thereof.

[0107] Aspect 10. The composition defined in any one of the preceding aspects, wherein the composition has a transmission efficiency characterized by an end of test temperature in a PV1454 (ARKL) test in any range of temperatures disclosed herein, e.g.. from 90 to 98 °C, from 93 to 98 °C, from 94 to 98 °C, from 94 to 97 °C, from 95 to 98 °C, or from 95 to 97 °C, and / or characterized by an end of test temperature that is from 35 to 43 °C, from 35 to 40 °C, from 35 to 39 °C, from 36 to 39 °C, from 35 to 38 °C, or from 36 to 38 °C less (AT) than that of a standard mineral oil control (correlating to an advantage in the range of 26-32% based on temperature).

[0108] Aspect 11. The composition defined in any one of the preceding aspects, wherein the composition comprises any amount of the PAO disclosed herein, e.g., at least 70 wt. %, at least 80 wt. %, at least 90 wt. %, from 50 to 99 wt. %, from 50 to 80 wt. %, from 70 to 95 wt. %, from 70 to 85 wt. %, from 80 to 98 wt. %, from 80 to 95 wt. %, or from 80 to 90 wt. %.

[0109] Aspect 12. The composition defined in any one of the preceding aspects, wherein the composition comprises any amount of the additive system disclosed herein, e.g., from 2 to 18 wt. %, from 3 to 15 wt. %, from 3 to 10 wt. %, from 4 to 15 wt. %, from 4 to 10 wt. %, from 5 to 12 wt. %, or from 6 to 10 wt. %.

[0110] Aspect 13. The composition defined in any one of the preceding aspects, wherein the PAO comprises any amount of hydrogenated 1 -dodecene dimer disclosed herein, e.g., at least 92 wt. %, at least 95 wt. %, at least 97 wt. %, at least 98 wt. %, or at least 99 wt. %.

[0111] Aspect 14. The composition defined in any one of the preceding aspects, wherein the PAO comprises any amount of C24 alkanes disclosed herein, e.g.. at least 92 wt. %, at least 95 wt. %, at least 97 wt. %, at least 98 wt. %, or at least 99 wt. %.

[0112] Aspect 15. The composition defined in any one of the preceding aspects, wherein the PAO has a 100 °C kinematic viscosity in any range of 100 °C kinematic viscosities disclosed herein, e.g., from 2 to 3 cSt, from 2. 1 to 2.8 cSt. from 2.2 to 2.7 cSt, or from 2.3 to 2.6 cSt. Aspect 16. The composition defined in any one of the preceding aspects, wherein the PAO has a 40 °C kinematic viscosity in any range of 40 °C kinematic viscosities disclosed herein, e.g., from 7 to 9 cSt, from 7.5 to 10 cSt, from 7.5 to 9 cSt, from 7.9 to 9 cSt, or from 8 to 8.5 cSt.

[0113] Aspect 17. The composition defined in any one of the preceding aspects, wherein the PAO has a flash point in any range of flash points disclosed herein, e.g., from 155 to 205 °C, from 155 to 200 °C. from 160 to 205 °C. from 160 to 200 °C, from 165 to 195 °C, or from 170 to 190 °C.

[0114] Aspect 18. The composition defined in any one of the preceding aspects, wherein the PAO has a pour point in any range of pour points disclosed herein, e.g., from -70 to -25 °C, from -65 to -35 °C, from -60 to -40 °C, from -60 to -45 °C, from -55 to -40 °C. or from -55 to -45 °C.

[0115] Aspect 19. The composition defined in any one of the preceding aspects, wherein the PAO has a density at 15.6 °C in any range of densities disclosed herein, e.g., from 0.803 to 0.810 g / cc. from 0.804 to 0.809 g / cc, from 0.8045 to 0.8085 g / cc, from 0.805 to 0.808 g / cc, from 0.8055 to 0.8075 g / cc, from 0.806 to 0.8075 g / cc, or from 0.806 to 0.807 g / cc.

[0116] Aspect 20. The composition defined in any one of the preceding aspects, wherein the PAO is characterized by a difference in high pressure viscosity at 826 MPa from 75 °C to 100 °C in any range of viscosity differences disclosed herein, e.g., from 10 to 35 mPa-s, from 15 to 40 mPa-s, from 15 to 35 mPa-s. from 15 to 30 rnPa-s, from 20 to 35 mPa-s. from 20 to 30 mPa-s, or from 22 to 28 mPa-s.

[0117] Aspect 21. The composition defined in any one of the preceding aspects, wherein the PAO is characterized by a difference in high pressure viscosity at 950 MPa from 75 °C to 100 °C in any range of viscosity differences disclosed herein, e.g., from 20 to 45 mPa-s, from 20 to 40 mPa-s, from 25 to 45 mPa-s, from 25 to 40 mPa-s, from 25 to 35 mPa-s, or from 27 to 33 mPa-s.

[0118] Aspect 22. The composition defined in any one of the preceding aspects, wherein the PAO is characterized by a phase transition at 40 °C at a pressure in any range of pressures disclosed herein, e.g., from 850 to 1100 MPa. from 850 to 1050 MPa, from 900 to 1100 MPa. or from 900 to 1050 MPa, in a high pressure viscosity’ test.

[0119] Aspect 23. A method of reducing wear, the method comprising lubricating a transmission system or drive train system with the lubricant composition defined in any one of aspects 1-22. Aspect 24. Use of the lubricant composition defined in any one of aspects 1-22 in a transmission or drive train system (e.g., of an electric vehicle).

[0120] Aspect 25. Use of the lubricant composition defined in any one of aspects 1-22 in an engine of a motorized vehicle. Aspect 26. A transmission or drive train formulation comprising the lubricant composition defined in any one of aspects 1-22.

[0121] Aspect 27. An engine oil formulation comprising the lubricant composition defined in any one of aspects 1-22.

[0122] Aspect 28. A grease formulation comprising the lubricant composition defined in any one of aspects 1-22.

[0123] Aspect 29. An electric vehicle comprising a transmission system, and the lubricant composition defined in any one of aspects 1-22.

Claims

CLAIMSWe claim:

1. A lubricant composition comprising:(i) at least 50 wt. % of a low viscosity PAO comprising at least 90 wt. % hydrogenated 1 -dodecene dimer; and(ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

2. A lubricant composition comprising:(i) at least 50 wt. % of a low viscosity PAO comprising at least 90 wt. % C24 alkanes; and(ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

3. A lubricant composition comprising:(i) at least 50 wt. % of a low viscosity PAO having (or characterized by): a 100 °C kinematic viscosity in a range from 1.8 to 3.6 cSt; a 40 °C kinematic viscosity' in a range from 7 to 11 cSt; and a flash point in a range from 150 to 210 °C; and(ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

4. A lubricant composition comprising:(i) at least 50 wt. % of a low viscosity PAO having (or characterized by): a difference in high pressure viscosity at 826 MPa from 75 °C to 100°C in a range from 10 to 40 mPa-s; or a difference in high pressure viscosity at 950 MPa from 75 °C to 100°C in a range from 20 to 50 rnPa-s; or both; and(ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

5. A lubricant composition comprising:(i) at least 50 wt. % of a low viscosity PAO having (or characterized by) a phase transition at 40 °C at a pressure in a range from 800 to 1100 MPa in a high pressure viscosity test; and(ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive and a dispersant.

6. A lubricant composition comprising:(i) at least 50 wt. % of the low viscosity PAO of any one of claims 1-5; and(ii) from 1 to 20 wt. % of an additive system comprising an anti-wear additive.

7. The composition of any one of the preceding claims, wherein the additive system further comprises a viscosity' modifier, a friction modifier / reducer, a detergent, a demulsifier, a defoamant, an antioxidant, an extreme pressure agent, a rust / corrosion inhibitor, a metal passivator, a pour point depressant, a thickener, or any combination thereof.

8. The composition of any one of the preceding claims, wherein the composition further comprise from 1 to 45 wt. % or from 10 to 30 wt. % of (iii) a base oil.

9. The composition of claim 8, wherein the base oil comprises: a Group I Base Oil, a Group 11 Base Oil, a Group III Base Oil, a Group IV Base Oil, a Group V Base Oil, or any combination thereof; and / or a second polyalphaolefin, a GTL fluid, or a combination thereof.

10. The composition of any one of the preceding claims, wherein the composition has a transmission efficiency characterized by: an end of test temperature in a PV1454 (ARKL) test in a range of from 90 to 98 °C or from 95 to 97 °C; and / or a AT versus a standard mineral oil control in a PV 1454 (ARKL) test in a range from 35 to 43 °C or from 36 to 38 °C.

11. The composition of any one of the preceding claims, wherein the composition comprises from 50 to 99 wt. % or from 80 to 90 wt. % of the PAO.

12. The composition of any one of the preceding claims, wherein the composition comprises from 2 to 18 wt. % or from 6 to 10 wt. % of the additive system.

13. The composition of any one of the preceding claims, wherein the PAO comprises at least 92 wt. % or at least 99 wt. % of hydrogenated 1 -dodecene dimer.

14. The composition of any one of the preceding claims, wherein the PAO comprises at least 92 wt. % or at least 99 wt. % of C24 alkanes.

15. The composition of any one of the preceding claims, wherein the PAO has a 100 °C kinematic viscosity from 2 to 3 cSt or from 2.3 to 2.6 cSt.1 . The composition of any one of the preceding claims, wherein the PAO has a 40 °C kinematic viscosity from 7 to 9 cSt or from 8 to 8.5 cSt.

17. The composition of any one of the preceding claims, wherein the PAO has a flash point from 155 to 205 °C or from 170 to 190 °C.

18. The composition of any one of the preceding claims, wherein the PAO has a pour point from -70 to -25 °C or from -55 to -45 °C.

19. The composition of any one of the preceding claims, wherein the PAO has a density at 15.6 °C from 0.803 to 0.810 g / cc or from 0.806 to 0.807 g / cc.

20. The composition of any one of the preceding claims, wherein the PAO is characterized by a difference in high pressure viscosity at 826 MPa from 75 °C to 100 °C in a range from 10 to 35 mPa-s or from 22 to 28 mPa-s.

21. The composition of any one of the preceding claims, wherein the PAO is characterized by a difference in high pressure viscosity at 950 MPa from 75 °C to 100 °C in a range from 20 to 45 mPa-s or from 27 to 33 mPa-s.

22. The composition of any one of the preceding claims, wherein the PAO is characterized by a phase transition at 40 °C at a pressure in a range from 850 to 1100 MPa or from 900 to 1050 MPa in a high pressure viscosity test.

23. A method of reducing wear, the method comprising lubricating a transmission system or drive train system with the lubricant composition of any one of claims 1-22.

24. Use of the lubricant composition of any one of claims 1-22 in a transmission or drive train system, such as in an electric vehicle.

25. A transmission or drive train formulation comprising the lubricant composition of any one of claims 1-22.

26. An electric vehicle comprising a transmission system and the lubricant composition of any one of claims 1 -22.

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