CN111868217B - Functional fluids comprising low viscosity polyalphaolefin base stocks - Google Patents

Abstract

Disclosed are functional fluids, such as automotive engine transmission fluids, clutch fluids, gearbox fluids, motor fluids, and/or battery cooling fluids, comprising low viscosity, low volatility polyalphaolefin base stocks, and methods of lubricating and/or cooling an engine transmission, motor, and/or battery using such functional fluids.

Description

Functional fluids comprising low viscosity polyalphaolefin base stocks

Priority declaration

The benefits and priorities of USSN 62/632,044 filed on day 19, 2018 and EP 18167068.8 filed on day 12, 2018 are claimed and incorporated in their entirety.

Technical Field

The present disclosure relates to functional fluids such as automotive engine transmission fluids, clutch fluids, gearbox fluids, motor cooling fluids, and battery pack cooling fluids. In particular, the present disclosure relates to functional fluids comprising low viscosity, low volatility polyalphaolefin basestocks.

Background

The engine transmission fluid lubricates components in the transmission and helps cool the operating transmission. The macroscopic trends in transmission fluids tend to be lower viscosity for better fuel economy. However, as the viscosity of the basestock decreases, the volatility of the basestock tends to increase, which can cause undesirable results in lubricant performance such as fluid loss, increased wear, and the like. Likewise, gearbox fluids, clutch fluids, and other mechanical system lubrication fluids may also benefit from lower operating viscosities for higher energy efficiency.

Furthermore, the development of hybrid and electric vehicles requires transmission fluids with very low viscosity bases in order to improve fuel economy and drive excellent heat transfer performance. These transmission fluids are subjected to high temperatures due to the close contact with the motor, and therefore the base requires low volatility, good oxidative stability, and good thermal stability. The electric motors and battery packs of hybrid and electric vehicles may need to be cooled by functional fluids during operation due to the heat generated by the large discharge current. Low viscosity, low volatility, good oxidative stability, and good thermal stability are also highly desirable for such functional fluids.

Conventional low viscosity polyalphaolefins ("PAOs") made by oligomerization of alpha-olefin monomers in the presence of lewis acid catalysts are available and indeed can be used in transmission fluids and other functional fluids. However, these fluids tend to suffer from one or more of the following: inadequate viscosity-volatility balance, inadequate oxidative and/or thermal stability, or high viscosity at high temperatures and high shear.

WO 2013/055480 a1 discloses a series of low viscosity PAO binders prepared as follows: (i) oligomerizing linear alpha-olefin ("LAO") monomer(s) in the presence of a catalyst system comprising a metallocene compound, or (ii) a hybrid process (a), comprising a first step of preparing a second oligomer from the oligomerization of LAO monomer(s) in the presence of a catalyst system comprising a metallocene compound, and subsequently oligomerizing the dimer with LAO monomer in the presence of a lewis acid catalyst. This patent reference also discloses engine oils comprising such low viscosity PAO base stocks. However, there is no mention in this patent reference of using such low viscosity PAO base in transmission fluids.

Drawings

Figure 1 is a schematic showing the MTM tractive effort at 80 ℃ for fluids 1,2, 3, and 4 in table 14 of the present disclosure.

FIG. 2 is a schematic diagram showing Dexron clutch friction durability (Dexron clutch friction durability) for fluids 5, 6, and 7 in Table 16 of the disclosure.

FIG. 3 is a graph showing the traction coefficient (traction coefficient) at 80 ℃ for fluids 8 and 9 in Table 17 of this disclosure.

FIG. 4 is a graph showing the traction coefficients at 120 ℃ for fluids 8 and 9 in Table 17 of this disclosure.

Disclosure of Invention

It has been surprisingly found that a low viscosity PAO base prepared as follows has excellent properties for functional fluids such as transmission fluids, particularly high quality transmission fluids, and a good balance of low viscosity and low volatility, particularly suitable for high demand transmissions found in modern hybrid vehicles: (i) oligomerizing linear alpha-olefin ("LAO") monomer(s) in the presence of a catalyst system comprising a metallocene compound, or (ii) a hybrid process comprising a first step of preparing a second oligomer, e.g. a dimer, from the oligomerization of LAO monomer(s) in the presence of a catalyst system comprising a metallocene compound, and subsequently oligomerizing said second oligomer with LAO monomer in the presence of a lewis acid catalyst.

Accordingly, a first aspect of the present disclosure is directed to a functional fluid for a transmission and/or an electric motor and/or a battery comprising a saturated polyalphaolefin ("PAO") first base stock in a concentration range of 3 wt% to 98 wt% thereof, the PAO base stock having, based on the total weight of the functional fluid: a kinematic viscosity at 100 ℃ of 3.0 to 4.5cSt, preferably 4.0cSt or less, more preferably 3.6cSt or less, still more preferably 3.5cSt or less ("KV 100") as determined according to ASTM D445; and a Noack volatility ("NV") of not greater than 15%, preferably ≦ 12.5%, as determined according to ASTM D5800.

A second aspect of the present disclosure relates to a method for lubricating and/or cooling an engine transmission, an electric motor, and/or a battery pack, comprising: (I) providing a functional fluid comprising a saturated polyalphaolefin ("PAO") first base stock in a concentration range of 3 wt% to 98 wt% thereof, the PAO base stock having, based on the total weight of the functional fluid: a kinematic viscosity at 100 ℃ (KV 100) of 3.0 to 4.5cSt, preferably ≦ 4.0cSt, more preferably ≦ 3.6cSt, still more preferably ≦ 3.5cSt, determined according to ASTM D445; and a Noack volatility ("NV") of no greater than 15%, preferably no greater than 12.5%, as measured according to ASTM D5800; and (II) contacting the functional fluid with an engine transmission, an electric motor, and/or a battery pack.

Detailed Description

The term "alkyl" or "alkyl group" refers interchangeably to a saturated hydrocarbon group consisting of carbon and hydrogen atoms. The alkyl group may be linear, branched linear, cyclic or substituted cyclic, wherein the substituent is an alkyl group.

The term "hydrocarbyl group" or "hydrocarbyl" refers interchangeably to a group consisting of only hydrogen and carbon atoms. The hydrocarbyl groups may be saturated or unsaturated, linear or branched linear, cyclic or acyclic, aromatic or non-aromatic.

The term "Cn" group, compound or oligomer refers to a group, compound or oligomer that contains carbon atoms in its total number of n. Thus, a "Cm-Cn" group, compound or oligomer refers to a group, compound or oligomer that contains carbon atoms in its total number in the range of m-n. Thus, C28-C32 oligomers refer to oligomers containing carbon atoms in their total number in the range of 28-32.

The term "carbon backbone" refers to the longest straight carbon chain in the molecule of the compound, group or oligomer in question. "branched" refers to any non-hydrogen group attached to a carbon backbone.

The term "olefin" refers to an unsaturated hydrocarbon compound having in its structure a hydrocarbon chain containing at least one carbon-carbon double bond, wherein the carbon-carbon double bond does not form part of an aromatic ring. The olefins may be linear, branched linear or cyclic. "alkene" is intended to encompass all structural isomeric forms of the alkene, unless a single isomer is expressly referenced or a difference is clearly indicated by context.

The term "alpha-olefin" refers to an olefin having a terminal carbon-carbon double bond in its structure ((R) ¹ R ² )-C＝CH ₂ Wherein R is ¹ And R ² May independently be hydrogen or any hydrocarbyl group, preferably R ¹ Is hydrogen, R ² Is an alkyl group). "Linear alpha-olefin" is as defined in this paragraph wherein R ¹ Is hydrogen, and R ² An alpha-olefin which is hydrogen or a linear alkyl group.

The term "vinyl" refers to an olefin having the formula:

wherein R is a hydrocarbyl group, preferably a saturated hydrocarbyl group, such as an alkyl group.

The term "vinylidene" refers to an olefin having the formula:

wherein R is ¹ And R ² Each independently is a hydrocarbyl group, preferably a saturated hydrocarbyl group, such as an alkyl group.

The term "1, 2-di-substituted vinylidene" means

(i) An olefin having the formula:

or

(ii) An olefin having the formula:

or

(iii) (iii) a mixture of (i) and (ii) in any proportion thereof,

wherein R is ¹ And R ² Each occurrence, which may be the same or different, is independently a hydrocarbyl group, preferably a saturated hydrocarbyl group, such as an alkyl group.

The term "tri-substituted vinylidene" refers to an olefin having the formula:

wherein R is ¹ 、R ² And R ³ Each independently is a hydrocarbyl group, preferably a saturated hydrocarbyl group, such as an alkyl group.

The term "tetra-substituted vinylidene" refers to an olefin having the formula:

wherein R is ¹ 、R ² 、R ³ And R ⁴ Each independently is a hydrocarbyl group, preferably a saturated hydrocarbyl group, such as an alkyl group.

As used herein, "polyalphaolefin(s)" ("PAO(s)") includes any oligomer(s) and polymer(s) of one or more alpha-olefin monomer(s). PAOs are oligomeric or polymeric molecules prepared by the polymerization of alpha-olefin monomer molecules in the presence of a catalyst system, optionally with further hydrogenation to remove residual carbon-carbon double bonds therein. Thus, the PAO may be a dimer, trimer, tetramer, or any other oligomer or polymer comprising two or more structural units derived from one or more alpha-olefin monomer(s). PAO molecules can be highly regio-regular (regio-r)Regular) such that the bulk material passes through ¹³ C NMR measurements show isotacticity, or syndiotacticity. The PAO molecules may be highly regionally irregular such that the bulk material passes through ¹³ The C NMR measurement is essentially atactic. PAO materials made using metallocene-based catalyst systems are typically referred to as metallocene-PAOs ("mpaos"), and PAO materials made using traditional non-metallocene-based catalysts (e.g., lewis acids, supported chromium oxides, etc.) are typically referred to as conventional PAOs ("cpaos").

The term "pendant group" with respect to a PAO molecule refers to any group attached to the carbon backbone other than hydrogen, except those groups attached to the carbon atoms at the furthest end of the carbon backbone.

The term "length" of a pendant group is defined as the total number of carbon atoms in the longest carbon chain in the pendant group, as measured from the first carbon atom attached to the carbon backbone. The pendant group may contain a cyclic group or a portion thereof in the longest carbon chain, in which case half of the carbon atoms in the cyclic group are calculated for the length of the pendant group. Thus, by way of example, a linear C8 side group has a length of 8; the pendant groups PG-1 (cyclohexylmethylene) and PG-2 (phenylmethylene) each have a length of 4; the pendant groups PG-3 (o-heptylphenylmethylene) and PG-4 (p-heptylphenylmethylene) each have a length of 11. When a PAO molecule contains multiple pendant groups, the arithmetic mean of the lengths of all such pendant groups is calculated as the average length of all pendant groups in the PAO molecule.

Unless otherwise specified, the term "substantially all" with respect to the PAO molecule means at least 90 mol% (e.g., at least 95 mol%, at least 98 mol%, at least 99 mol%, or even 100 mol%).

Unless otherwise specified, the term "consisting essentially of …" means included at a concentration of at least 90 mol% (e.g., at least 95 mol%, at least 98 mol%, at least 99 mol%, or even 100 mol%).

Unless otherwise specified, the term "substantially free" with respect to a particular component means that the concentration of that component in the relevant composition is at most 10 mol% (e.g., at most 5 mol%, at most 3 mol%, or at most 1 mol%) based on the total amount of the relevant composition.

As used herein, "lubricant" refers to a substance that can be introduced between two or more moving surfaces and reduce the level of friction between two adjoining surfaces that move relative to each other. A lubricant "base stock" is a material used to formulate a lubricant by blending it with other components, typically a fluid at the operating temperature of the lubricant. Non-limiting examples of suitable base stocks in lubricants include API group I, group II, group III, group IV and group V base stocks. Fluids derived from the fischer-tropsch or Gas-to-Liquid ("Gas-to-Liquid, GTL") processes are examples of synthetic base stocks that may be used to make modern lubricants. GTL base stocks and methods for their manufacture can be found, for example, in WO2005/121280a1 and U.S. patent nos. 7,344,631; 6,846,778, respectively; 7,241,375, respectively; 7,053,254.

All kinematic viscosity values in this disclosure are determined according to ASTM D445. The kinematic viscosity at 100 ℃ is reported herein as KV100 and the kinematic viscosity at 40 ℃ is reported herein as KV 40. All KV100 and KV40 values are in units of cSt unless otherwise specified.

All viscosity index ("VI") values in this disclosure are determined according to ASTM D2270.

All Noack volatility ("NV") values in this disclosure are determined according to ASTM D5800, unless otherwise specified. All NV values are in wt% unless otherwise specified.

All pour points in this disclosure are determined according to ASTM D5950. All pour point values are in units of ° c unless otherwise specified.

All rotary pressure vessel oxidation test ("RPVOT") values in this disclosure are determined in accordance with ASTM D2272. All RPVOT values are in minutes unless otherwise specified.

All cold-start simulator viscosity ("CCSV") values in this disclosure are determined in accordance with ASTM D5293. All units of CCSV values are centipoise (millipascal-seconds) unless otherwise specified.

All high temperature high shear viscosity ("HTHSV") values in the present disclosure are determined according to ASTM D4683. HTHSV values are in centipoise unless otherwise specified.

All Brookfield viscosity ("Brookfield") values in this disclosure are determined according to ASTM D2983. The units of Brookfield values are in centipoise, unless otherwise specified.

All MRV apparent viscosity ("MRV") values in this disclosure are determined according to ASTM D4674. All MRV values are in centipoise unless otherwise specified.

All heat capacity values in this disclosure are determined according to ASTM E1269. The unit of the heat capacity value is J (g.K) ^-1 Unless otherwise specified.

All thermal conductivity values in this disclosure are determined in accordance with ASTM E1269. The unit of the thermal conductivity value is W (m.K) ^-1 Unless otherwise specified.

All numbers expressing "about" or "approximately" means modifying through the numerical values specified in the detailed description and claims herein, and taking into account experimental error and deviation as would be expected by one of ordinary skill in the art.

In the present disclosure, all percentages of pendant groups, terminal carbon chains, and side chain groups are calculated on a molar basis unless otherwise specified. The molar percentage is expressed as "mol%", and the weight percentage is expressed as "wt%".

In the present disclosure, all molecular weight data are in units of g.mol ^-1 . Gel Permeation Chromatography (GPC) by using a multichannel bandpass filter-based infrared detector assembly IR5(GPC-IR) to cover 2700- ^-1 The band (all saturated C-H stretching vibrations) of (a) measure the molecular weight and distribution of the oligomeric or polymeric materials (including hydrogenated and unsaturated PAO materials) in this disclosure. Reagent grade 1,2, 4-Trichlorobenzene (TCB) (from Sigma-Aldrich) containing 300ppm of the antioxidant BHT was used as the mobile phase at a nominal flow rate of 1.0mL/min and a nominal injection volume of 200 μ L. The oven maintained at 145 ℃ was charged with the entire system including transfer lines, columns and detectors. Weighing a given amount of sample and sealing it in the targetIn the quasi-vial, 10. mu.L of the flow marker (heptane) was added thereto. After loading the vial in the autosampler, the oligomer or polymer was automatically dissolved in an instrument containing 8mL of added TCB solvent with continuous shaking at 160 ℃. The sample solution concentration is 0.2-2.0mg/ml, with lower concentrations being used for higher molecular weight samples. The concentration (c) for each point in the chromatogram was calculated from the baseline-subtracted IR5 broadband signal (I) using the following equation: where α is the mass constant determined with polyethylene or polypropylene standards. The mass recovery is calculated from the ratio of the integrated area of the concentration chromatogram to the elution volume, and the injection mass is equal to the pre-determined concentration multiplied by the injection loop volume. Molecular weight was determined by combining the universal calibration relationship with the mark-hough temperature equation where the M-H parameter a/K for mPAO is 0.695/0.00012. The number average molecular weight (Mn) and weight average molecular weight (Mw) of the oligomer or polymer are obtained from the above-described method. The polydispersity index (PDI) of the material is then calculated as follows:

PDI＝Mw/Mn。

NMR spectroscopy provides key structural information related to the synthesis of polymers. Proton NMR of unsaturated PAO materials (C ¹ H-NMR) analysis gave quantitative decomposition (quaternary breaking down) of the olefinic structure types (i.e., vinyl, 1, 2-di-substituted vinylidene, tri-substituted vinylidene, and vinylidene). In the present disclosure, by using ¹ H-NMR determines the composition of olefin mixtures containing terminal olefins (vinyl and vinylidene) and internal olefins (1, 2-di-and tri-substituted vinylidene). In particular, an NMR instrument of at least 500MHz operates under the following conditions: 30 flip angle RF pulses, 120 scans with 5 second delay between pulses; the sample was dissolved in CDCl ₃ (deuterated chloroform); the signal collection temperature was 25 ℃. The concentrations of the various olefins among all the olefins were determined from the NMR spectrum by the following method. First, peaks corresponding to different types of hydrogen atoms in vinyl group (T1), vinylidene group (T2), 1, 2-di-substituted vinylidene group (T3) and tri-substituted vinylidene group (T4) were identified. Next, the area of each of the above peaks (a 1, a2, A3, and a4, respectively) was then integrated. Third, each type of olefin (Q1, Q2, Q3, and Q4, respectively) was calculated on a molar basisAmounts of (A1/2, A2/2, A3/2 and A4, respectively). Fourth, the total amount of all olefins in moles (Qt) was calculated as the total amount of all four types (Qt-Q1 + Q2+ Q3+ Q4). Finally, the molar concentration of each type of olefin (C1, C2, C3, and C4, respectively, in mol%) was then calculated, based on the total molar amount of all olefins (Ci ═ 100 × Qi/Qt in each case).

In the present disclosure, a method is described as including at least one "step". It will be understood that each step is an action or operation that can be performed one or more times in a continuous or discontinuous manner in the method. Unless stated to the contrary or the context clearly indicates otherwise, each step in the method may be performed in the order in which they are listed, with or without overlap with one or more other steps, or in any other order, as the case may be. In addition, one or more, or even all, of the steps may be performed simultaneously on the same or different batches of material. For example, in a continuous process, while the first step in the process is being carried out on the starting material that was just fed into the process, the second step may be carried out simultaneously on an intermediate product produced by treating the starting material fed into the process at an early stage in the first step. Preferably, the steps are performed in the order recited.

The indefinite articles "a" or "an" as used herein shall mean "at least one" unless specified to the contrary or the context clearly indicates otherwise. Thus, embodiments using "a given device" include embodiments in which one, two, or more such given devices are used, unless specified to the contrary or the context clearly indicates that only one such given device is used.

Unless otherwise indicated, all numbers expressing quantities in the present disclosure are to be understood as being modified in all instances by the term "about". It should also be understood that the precise numerical values used in the specification and claims constitute specific embodiments. Efforts have been made to ensure the accuracy of the data in the embodiments. However, it should be understood that any measured data inherently contains some level of error due to the limitations of the techniques and equipment used to make the measurements.

PAO first base stock

The functional fluids of the present disclosure comprise a PAO first binder as a primary or co-binder. The PAO first base is desirably a low viscosity, low volatility base, particularly suitable for use in functional fluids for engine transmissions for internal combustion engines, including automatic and manual transmissions, gas/electric hybrid engine transmissions, diesel/electric hybrid engine transmissions, electric motors and even battery packs, to lubricate and/or cool the transmission, electric motor and/or battery pack, such as those installed in modern gas or diesel powered, gas/electric powered, diesel/electric powered and electric vehicles.

The PAO first binder desirably has a KV100 of v1-v 2cSt, where v1 and v2 can be independently 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, and 4.5. Preferably, v1 is 3.0 and v2 is 4.0. More preferably, v 1-3.0 and v 2-3.6. More preferably, v1 is 3.0 and v2 is 3.5. The low viscosity of the PAO first base reduces traction losses during high speed movement of components in the transmission, thereby achieving high energy efficiency and low transmission operating temperatures. The low viscosity of the PAO first base enables the functional fluid to circulate at high speed when pumped in a loop, thereby enabling the ability to achieve high cooling efficiency if used as a cooling medium for an electric motor and/or battery pack.

The PAO first binder desirably has a low NV value as determined according to ASTM D5800 of at most 15.0 wt%, preferably at most 14.0 wt%, more preferably at most 13.0 wt%, still more preferably at most 12.5 wt%. The PAO base in the functional fluids of the present disclosure tend to have a lower NV value than conventional PAO bases commercially available at the same viscosity. The low NV value of the PAO first base contributes to consistent viscosity and performance of the functional fluids of the present disclosure over a long service life without the need for maintenance and fluid replacement.

The PAO first base may desirably have a composition of 0.11-0.16W (m.K) ^-1 Thermal conductivity of (2) at 40 ℃.

The PAO first binder is desirably a saturated alkane, substantially free of olefinic double bonds in its molecule.

The PAO first base stock may desirably have a cold cranking simulator viscosity ("CCSV") of no greater than 1,000 centipoise as measured according to ASTM at-35 ℃. Desirably, the PAO first base stock may have a CCSV at-35 ℃ of a1-a2 centipoise, where a1 and a2 may be independently 500, 550, 600, 650, 700, 750, 800, 850, 900, or 1000, as long as a1< a 2. The extremely low CCSV of the PAO first base makes it particularly useful for engine transmission fluids that sometimes operate at low temperatures in cold climates. The PAO first base may be particularly advantageous in this regard compared to commercially available conventional PAO bases.

The PAO first binder may desirably have a high temperature high shear viscosity ("HTHSV") of up to 1.4 centipoise as determined according to ASTM D4683 at 150 ℃. Desirably, the PAO first binder may have a 150 ℃ HTHSV of 1.0 to 1.4 centipoise, preferably 1.0 to 1.3 poise, more preferably 1.0 to 1.2 poise. Lower HTHSV can provide improved fuel economy for lubrication applications because lower viscosities enable reduced friction to be achieved.

The PAO first base desirably has a high oxidative stability as measured by Rotary Pressure Vessel Oxidation Test (RPVOT) time to failure in accordance with ASTM D-2272 of at least about 60 minutes, preferably at least 70 minutes, more preferably at least 80 minutes. With conventional Lewis acids such as BF ₃ Compared to conventional low viscosity PAO bases having similar KV100 values produced by oligomerization of alpha-olefins in the presence, the PAO first base may have much higher oxidative stability as indicated by much longer RPVOT times.

The PAO first base may desirably comprise C28 to C32 polyalphaolefin oligomers in a total concentration of at least 90 wt%, preferably at least 92 wt%, more preferably at least 94 wt%, still more preferably at least 95 wt%, still more preferably at least 96 wt%, still more preferably at least 97 wt%, still more preferably at least 98 wt% thereof. A narrow molecular weight distribution is achieved by this high percentage of oligomers with tight molecular weights.

In one embodiment, the PAO first binder desirably may comprise C30 polyalphaolefin oligomers in a total concentration of at least 90 wt%, preferably at least 92 wt%, more preferably at least 94 wt%, still more preferably at least 95 wt%, still more preferably at least 96 wt%, still more preferably at least 97 wt%, still more preferably at least 98 wt% thereof,based on the total weight of the first base stock. The C30 polyalphaolefin oligomer may suitably be of the formula C ₃₀ H ₆₂ Meaning that it can be a mixture of a plurality (e.g., two, three, four, or more) alkane isomers. In one example, such a PAO first binder may comprise a PAO having formula C in a total concentration of at least 50 wt%, 60 wt%, 70 wt%, 80 wt%, or even 90 wt% ₃₀ H ₆₂ Based on C ₃₀ H ₆₂ Total moles of isomers.

The PAO first base stock may comprise polyalphaolefin oligomers having the formula, based on the total weight of the first base stock, in a total concentration of at least 50 wt%, preferably at least 60 wt%, more preferably at least 70 wt%, still more preferably at least 80 wt%, still more preferably at least 90 wt%, still more preferably at least 95 wt% thereof:

wherein each R is independently n-butyl, n-hexyl, n-octyl, n-decyl, or n-dodecyl. Preferably, such PAO oligomers are C28-C32 oligomers. Preferably, the different R groups contain carbon numbers that differ by at most 2. In a preferred embodiment, all R groups are n-octyl.

The PAO first base stock desirably has high oxidation resistance, particularly at high operating temperatures within engine transmissions, especially hybrid engine transmissions. Please provide a description of the oxidation resistance of this material; explaining what causes the high oxidation resistance of this base material.

Method for producing PAO first base Material

At least a portion of the PAO first base stock may desirably be prepared by a process selected from the group consisting of:

(i) a first process comprising oligomerizing one or more C6-C14 alpha-olefins in the presence of a catalyst system comprising a metallocene compound to obtain a first oligomer mixture, separating a first unhydrogenated precursor to be the first base stock from the oligomer mixture, and then hydrogenating the first unhydrogenated precursor; and

(ii) a second method, comprising: a first step of preparing a second oligomer of one or more C6-C14 alpha-olefins in the presence of a catalyst system comprising a metallocene compound, a second step of reacting the second oligomer with one or more C6-C14 alpha-olefins in the presence of a lewis acid catalyst to obtain a third oligomer mixture, a third step of separating a second unhydrogenated precursor to be the first base stock from the third oligomer mixture, and a fourth step of subsequently hydrogenating the second unhydrogenated precursor.

Thus, all of the PAO first binder may be prepared by process (i) or process (ii) described above. Alternatively, the PAO oligomers produced by process (i) and those produced by process (ii) above may be combined together in any ratio to produce the PAO first base stock of the present disclosure.

WO 2013/055480A 1 discloses the above processes (i) and (ii), the contents of which are incorporated herein by reference in their entirety.

In process (i) or process (ii), the C6-C14 alpha-olefin is preferably a linear alpha-olefin, such as 1-hexene, 1-octene, 1-decene, 1-dodecene and 1-tetradecene. Preferred alpha-olefins for processes (i) and (ii) are 1-octene, 1-decene and 1-dodecene. The most preferred alpha-olefin is 1-decene, especially when a single alpha-olefin is used to make the PAO first base stock. If two different alpha-olefins are used in substantial concentrations (e.g. above 5 mol%, based on the total moles of alpha-olefins), it is preferred that they contain carbon numbers that differ by at most 4, still more preferably at most 2. If three different alpha-olefins are used in substantial concentrations, it is preferred that they contain carbon numbers that differ by at most 6, still more preferably at most 4. The close molecular weights of the various alpha-olefin monomers used in the process contribute to the high degree of uniformity in molecular weight among the molecules included in the first PAO base stock. In a preferred embodiment, in process (i) or (ii), a single alpha-olefin monomer is used to make the PAO first base stock. In a preferred embodiment of process (ii), in the first step, a single alpha-olefin is used to make the second oligomer. In a preferred embodiment of process (ii), in the first step, the second oligomer is a dimer of the alpha-olefin(s).

In a preferred embodiment of process (i), the first unhydrogenated precursor consists essentially of the trimer(s). Thus, when 1-decene is used as the sole alpha-olefin for making the PAO first base stock in process (i), the first unhydrogenated precursor preferably consists essentially of C ₃₀ H ₆₀ And (4) forming.

In a preferred embodiment of process (ii), the second oligomer consists essentially of dimer(s). Thus, when 1-decene is used as the single alpha-olefin to make the second oligomer, the second oligomer is preferably made substantially of C ₂₀ H ₄₀ And (4) forming. In this case, the second unhydrogenated precursor preferably consists of the trimer(s). Thus, when 1-decene is used as the single alpha-olefin to make the second oligomer and the third oligomer mixture, the second unhydrogenated precursor preferably consists essentially of C ₃₀ H ₆₀ And (4) forming.

In a preferred embodiment of process (ii), the second oligomer comprises at least 20 (or 25, 30, 35, 40, 45, 50, 55, 60) wt% tri-substituted olefin. In such embodiments, the second unhydrogenated precursor preferably comprises at least 50 (or 55, 60, 65, 70, 75, or even 80) wt% total tri-and tetra-substituted olefins, in total, based on the total moles of olefins in the second unhydrogenated precursor.

It is believed that after hydrogenation, substantially all of the C ═ C double bonds present in the olefinic oligomer molecules in the first or second unhydrogenated precursors are saturated and the alkane molecules are prepared to constitute the PAO first base stock of the present disclosure.

Functional fluids

III.1 overview

The functional fluids of the present disclosure comprise the aforementioned PAO first binder as a major component. The concentration of the PAO first binder in the functional fluid of the present disclosure may be, for example, x1-x2 wt%, where x1 and x2 may be independently 3, 4, 5, 6,7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99, as long as x1< x2, based on the total weight of the functional fluid.

As noted above, the PAO binder may be present in the functional fluid as a primary or co-binder. In particular, when the functional fluid is an automotive transmission fluid, a clutch fluid or a battery cooling fluid, the PAO first base may advantageously be present as the primary base in a concentration of, for example, at least 50 wt%, based on the total weight of the functional fluid. When the functional fluid is an industrial gearbox fluid that may comprise a high viscosity PAO base as a primary base, the low viscosity PAO primary base may be present in the functional fluid as a co-base included at a lower treat rate (treat rate), for example at a treat rate of 3 wt% to 20 wt%, based on the total weight of the functional fluid.

Thus, the functional fluids of the present disclosure desirably have KV100 of v3-v 4cSt, where v3 and v4 can be independently 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, or 4.2, as long as v3< v 4. Preferably, v3 is 3.5 and v4 is 4.0. More preferably, v3 is 3.5 and v4 is 3.8.

The functional fluids of the present disclosure desirably have a low Noack volatility ("NV") value of 10 to 15 wt%, preferably 10 to 13 wt%, more preferably 10 to 12 wt%, still more preferably 10 to 11 wt%. A lower NV value means less loss of fluid throughout the life of the fluid and thus more consistent fluid performance throughout the fixed displacement period and/or longer life at a given fluid loss target. The low NV value of the functional fluids of the present disclosure is at least partially conferred by the low NV value of the first PAO base.

The functional fluids of the present disclosure may desirably have high heat transfer efficiency.

The functional fluids of the present disclosure may benefit from the high oxidative stability of the first PAO base and enjoy a long service life.

The functional fluid of the present disclosure may be any engine transmission fluid. Engine transmission fluid is typically disposed within a housing of a transmission unit that includes a plurality of moving parts, such as gear teeth. Transmission fluids present between hard surfaces (e.g., metal surfaces) that move relative to each other desirably form a thin film that protects the surfaces from direct contact and abrasion. The lower viscosity of the transmission fluid reduces traction losses and is therefore desirable.

The functional fluids of the present disclosure may be particularly advantageous as gasoline-electric or diesel-electric hybrid engine transmission fluids. In a hybrid engine powered vehicle, the transmission fluid typically contacts both the transmission and the electric motor, which may operate at high temperatures when high currents are passed through. The high oxidative stability of the first PAO binder is the thermal stability of the functional fluid containing it as a major component.

The functional fluid of the present disclosure may be a cooling fluid for an electric motor or battery pack. Under high current conditions, the electric motor and battery pack of an electric vehicle or hybrid vehicle may reach high temperatures if not properly cooled. The low viscosity, high oxidation stability functional fluids of the present disclosure can provide excellent cooling performance for electric motors and/or batteries.

III.2 other base stocks which can be used in lubricating oils

A wide range of lubricating oil base stocks known in the art may be used with the PAO first base stock in the functional fluids of the present disclosure, typically as a co-base stock. Such other base stocks may be derived from natural sources or from synthetic sources, including unrefined, refined, or re-refined oils. Unrefined oil bases include shale oil obtained directly from a retorting operation, petroleum oil obtained directly from primary distillation, and ester oil obtained directly from natural sources (e.g., plant matter and animal tissue) or obtained directly from a chemical esterification process. Refined oil base stocks are those unrefined base stocks that have been further subjected to one or more purification steps such as solvent extraction, secondary distillation, acid extraction, base extraction, filtration, and percolation to improve the properties of at least one lubricating oil. Rerefined oil base stocks are obtained by processes similar to those used for refining oils except that the oils that have been previously used as feedstocks are used.

API groups I, II, III, IV and V are broad categories of base stocks developed and specified by the American Petroleum Institute (API Publication 1509; www.API.org) to establish guidelines for lubricant base stocks. Group I bases generally have a viscosity index of about 80-120 and contain greater than about 0.03% sulfur and less than about 90% saturates. Group II bases generally have a viscosity index of about 80 to 120 and contain less than or equal to about 0.03% sulfur and greater than or equal to about 90% saturates. Group III basestocks generally have a viscosity index greater than about 120 and contain less than or equal to about 0.03% sulfur and greater than about 90% saturates. Group IV includes Polyalphaolefins (PAO). Group V materials include base materials not included in groups I-IV. The following table summarizes the properties of each of these five groups.

Natural oils include animal oils (e.g., lard), vegetable oils (e.g., castor oil), and mineral oils. Animal and vegetable oils with advantageous thermo-oxidative stability can be used. Among natural oils, mineral oils are preferred. Mineral oils vary widely according to their natural source, for example, according to whether they are paraffinic, naphthenic, or mixed paraffinic-naphthenic. Oils derived from coal or shale are also useful in the present disclosure. Natural oils also vary in the process used for their production and purification, such as their distillation range and whether they are straight-run or cracked, hydrofinished or extracted with a solvent.

Group II and/or group III basestocks are typically hydrotreated or hydrocracked basestocks derived from a crude oil refinery process.

Synthetic binders include polymerized and interpolymerized olefins (e.g., polybutylene, polypropylene, propylene isobutylene copolymer, ethylene-olefin copolymer, and ethylene-alpha-olefin copolymer).

Synthetic polyalphaolefin ("PAO") base stocks are placed in group IV. Advantageous group IV base stocks are those made from one or more of C6, C8, C10, C12, and C14 linear alpha-olefins ("LAO"). These binders are commercially available in a wide range of viscosities, for example KV100 in the range of 1.0 to 1,000 cSt. Additional PAO binders can be prepared by polymerizing LAO(s) in the presence of lewis acid type catalysts, or in the presence of metallocene compound based catalyst systems. A high quality group IV PAO commercial base stock includes a base stock available from Bayway Drive, Baytown, Texas 7 having the address 45007450 SpectraSyn available from ExxonMobil Chemical Company of United States ^TM And SpectraSyn Elite ^TM And (4) series.

All other synthetic binders, including but not limited to alkylaromatics and synthetic esters, are in group V.

Minor amounts of esters may be used in the functional fluids of the present disclosure. Additive solvency and seal compatibility characteristics can be imparted by utilizing esters such as esters of dibasic acids with monoalkanols and polyol esters of monocarboxylic acids. The former type of esters include, for example, esters of dicarboxylic acids such as phthalic acid, succinic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, caronic acid, alkyl caronic acids, alkenyl caronic acids, and the like with various alcohols such as butanol, hexanol, dodecanol, 2-ethylhexanol, and the like. Specific examples of these types of esters include dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, eicosyl sebacate, and the like. Useful ester group V binders include esters commercially available from ExxonMobil Chemical Company ^xTM And (4) series.

One or more of the following may also be used as binders in the functional fluids of the present disclosure: (1) one or more gas-to-liquid (GTL) materials; and (2) hydrodewaxing, hydroisomerizing, solvent dewaxing or catalytic dewaxing base stocks derived from synthetic waxes, natural waxes, waxy feedstocks, slack waxes, gas oils, waxy fuels, hydrocracker bottoms, waxy raffinates, hydrocrackers, thermal cracked products, oil bottoms, and waxy materials derived from coal liquefaction or shale oils. Such waxy feeds may be derived from mineral oil or non-mineral oil processing or may be synthetic (e.g., fischer-tropsch feedstock). Such binders preferably comprise C20 or higher, more preferably C30 or higher linear or branched hydrocarbyl compounds.

The functional fluids of the present disclosure may comprise one or more group I, II, III, IV, or V binders in addition to the CCSV lift binder. Preferably, group I binders, if any, are present in lower concentrations if high quality functional fluids are desired. Group I binders may be introduced in small amounts as diluents for the additive package. Group II and group III binders may be included in the functional fluids of the present disclosure, but preferably only those having high quality, such as those having a VI of 100-120. Group IV and group V base stocks, preferably those having high quality, may desirably be included in the functional fluids of the present disclosure as co-base stocks at lower treat rates than the PAO first base stock.

III.3 additives

The functional fluids of the present disclosure may also contain one or more conventional lubricating oil performance additives including, but not limited to, dispersants, detergents, viscosity modifiers, antiwear additives, corrosion inhibitors, rust inhibitors, metal deactivators, extreme pressure additives, anti-seizure agents, wax modifiers, viscosity modifiers, fluid loss additives, seal compatibilisers, lubricants, anti-staining agents, colourants, antifoamants, demulsifiers, thickeners, wetting agents, gelling agents, mastics, colourants, and the like. For a review of many commonly used additives and amounts used, see: (i) klamann in Lubricants and Related Products, Verlag Chemie, Deerfield Beach, FL; ISBN 0-89573-177-0; (ii) "Lunbrict Additives," M.W.Ranney, published by Noyes Data Corporation of Parkridge, NJ (1973); (iii) "Synthesis, Mineral Oils, and Bio-Based Lubricants," modified by L.R. Rudnick, CRC Taylor and Francis,2006, ISBN 1-57444-723-8; (iv) "Lubrication Fundamentals", J.G. Wills, Marcel Dekker Inc. (New York, 1980); (v) synthetic Lubricants and High-Performance Functional Fluids,2nd Ed., Rudnick and Shunkin, Marcel Dekker Inc. (New York,1999) and (vi) "polyalphaolekiness," L.R.Rudnick, Chemical Industries (Boca Raton, FL, United States) (2006),111(Synthetic, Mineral Oils, and Bio-Based Lubricants), 3-36. Reference is also made to: (a) U.S. patent nos. 7,704,930B 2; (b) U.S. Pat. No. 9,458,403B 2 at column 18, line 46 to column 39, line 68; (c) U.S. patent No. 9,422,497B 2 at column 34, line 4 to column 40, line 55; (d) U.S. patent No. 8,048,833B 2 from column 17, line 48 to column 27, line 12; (e) U.S. patent application publication No. 2014/0113847A 1, page 7 paragraph [0083] to page 15 paragraph [0215], and (f) the disclosures of which are incorporated herein by reference in their entirety. These additives are typically delivered prior to introduction into the formulated oil with varying amounts of diluent oil, which may range from 5 wt% to 50 wt%, based on the total weight of the additive package. Additives useful in the present disclosure need not be soluble in the functional fluid. Insoluble additives in oil may be dispersed in the functional fluids of the present disclosure.

When the functional fluid contains one or more of the above additives, the additive(s) are blended into the oil composition in an amount sufficient to perform their intended function.

It should be noted that many additives are shipped from additive manufacturers as concentrates that contain one or more additives along with a certain amount of base oil diluent. Accordingly, the amounts by weight in the following table, as well as other amounts referred to herein, refer to the amount of active ingredient (i.e., the non-diluent portion of the ingredient). The weight percentages (wt%) indicated below are based on the total weight of the lubricating oil formulation.

Examples of techniques that may be employed to characterize the above-described CCSV promoted base include, but are not limited to, analytical gas chromatography, nuclear magnetic resonance, thermogravimetric analysis (TGA), inductively coupled plasma mass spectrometry, Differential Scanning Calorimetry (DSC), and volatility and viscosity measurements.

The disclosure is further illustrated by the following non-limiting examples.

Examples

Preparation of Low viscosity PAO base stock

The structure of the synthesized oligomers was determined and the composition of each structure quantified using nuclear magnetic resonance spectroscopy (NMR) enhanced by confirmation and integration of end group resonances and removal of their contribution to peak area.

Proton NMR (also commonly referred to as HNMR) spectroscopic analysis can distinguish and quantify the ethylenic unsaturation: vinylidene, 1, 2-disubstituted, trisubstituted, or vinyl types. The carbon-13 NMR (C-NMR) spectrum confirms the olefin distribution calculated from the proton spectrum. Both methods of NMR analysis are well known in the art.

Quantitative analysis of the olefinic structure distribution in pure dimer samples containing unsaturated hydrogen atoms was performed by HNMR and is described below. Since this technique detects hydrogen, any unsaturated species (tetra-substituted olefin) that does not contain olefinic hydrogen is not included in the analysis (C-NMR must be used to determine the tetra-substituted olefin). The analysis of the olefinic region is carried out by measuring the normalized integrated intensity in the identified spectral region. The relative number of olefinic structures in the sample was then calculated as follows: the respective zone intensities are divided by the number of olefinic hydrogen species in the unsaturated structure represented in the zone. Finally, the percentages of the different olefin types were determined as follows: the relative amount of each olefin type is divided by the total amount of these olefins in the sample.

C-NMR was used to confirm and quantify the olefinic structure in the fluid. The classification of unsaturated carbon types based on the number of hydrogen atoms connected is determined by comparing spectra collected using APT (Patt, s.l.; Shoolery, n., j.mag.reson.,46:535(1982)) and DEPT (Doddrell, d.m.; Pegg, d.t.; Bendall, m.r., j.mag.reson.,48:323(1982)) pulse sequences. APT data detects all carbons in the sample, while DEPT data contains signals from only hydrogen-attached carbons. Carbons having an odd number of hydrogen atoms directly attached are represented by the signals: the signal has an opposite polarity to those with two hydrogen atoms (DEPT data) or with zero or two attached hydrogens in the case of APT spectra. Thus, the presence of a carbon signal in the APT spectra that is not present in the DEPT data and has the same signal polarity as a carbon having two attached hydrogen atoms indicates a carbon without any attached hydrogen. The carbon signal showing this polarity relationship in the chemical shift between 105 and 155ppm in the spectrum is classified as carbon in the olefinic structure.

With olefinic carbons previously classified according to the number of hydrogens attached, signal intensity can be used to identify the two carbons bonded together in the unsaturated structure. The intensity used was evaluated from the C-NMR spectra collected using quantitative conditions. Since each olefinic bond consists of a pair of carbons, the signal intensity from each carbon will be similar. Thus, by matching the intensities to the above identified carbon types, the different kinds of olefinic structures present in the sample are determined.

As discussed previously, vinyl olefins are defined as containing one unsaturated carbon bonded to two hydrogens (bonded to a carbon containing one hydrogen), vinylidene olefins are identified as having a carbon with two hydrogens bonded to a carbon without any attached hydrogen, and tri-substituted olefins are identified as having two carbons containing one hydrogen atom in the unsaturated structure. Tetra-substituted olefinic carbons are unsaturated structures in which none of the carbons in the unsaturated structure have any directly bonded hydrogen.

Quantitative C-NMR spectra were collected using the following conditions: samples were incubated with 0.1M relaxant Cr (acac) ₃ A 50-75 wt% solution of (tris (acetylacetonate) -chromium (III)) in deuterated chloroform was placed in an NMR spectrometer. Using with reverse gating ¹ H decoupled 30 degree pulses collect data to suppress any nuclear magnetic euclidean effect and an observed scan width of 200 ppm.

Quantification of olefin content in the samples was calculated as follows: the normalized average intensity of carbon in the olefinic bond is multiplied by 1000 divided by the total carbon intensity attributable to the fluid sample. The percentage of each olefinic structure can be calculated as follows: all the olefinic structures identified are added and the total amount is divided into the individual structural amounts.

The composition by molecular weight of the synthesized oligomers was determined using Gas Chromatography (GC). The gas chromatograph is an HP model equipped with 15 meters of dimethylsiloxane. 1 microliter of sample was injected into the column at 40 ℃ for 2 minutes, heated to 350 ℃ with an 11 ℃/minute program and held for 5 minutes. The sample was then heated to 390 ℃ at a rate of 20 ℃/min and held for 17.8 minutes. The content of dimers, trimers and tetramers having a total carbon number of less than 50 can be quantitatively analyzed using a GC method. The composition distributions of dimers, trimers and tetramers and/or pentamers can be fitted to a Bernoullian distribution and the degree of randomness can be calculated from the difference between the GC analysis and the best fit calculation.

Example 1

1-decene, 97% pure, was fed to a stainless steel Parr reactor where it was sparged with nitrogen for 1 hour to obtain a purified feed. The purified stream of 1-decene was then fed to a stainless steel Parr reactor at a rate of 2080 g/hr for oligomerization. The oligomerization temperature was 120 ℃. The catalyst was dimethylsilyl-bis (tetrahydroindenyl) zirconium dimethyl (hereinafter referred to as "catalyst 1"). A catalyst solution comprising purified toluene, tri-N-octylaluminum (TNOA), and N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate (hereinafter referred to as "activator 1") was prepared according to the following formulation, based on 1 gram of catalyst 1:

the 1-decene and catalyst solution were fed into the reactor at a ratio of 31,200 grams 1-decene per gram of catalyst solution. Additional TNOA was also used as a scavenger to remove any polar impurities and was added to the reactor at a ratio of 0.8 grams of 0.25% TNOA in toluene per 100 grams of purified LAO. The residence time in the reactor was 2.7 hours. The reactor was operated at full liquid conditions (without any gas addition).

When the system reaches steady state, a sample is taken from the reactor effluent and the dimer fraction is separated by distillation. The mass percent of each type of olefin in the distilled intermediate PAO dimer (as determined by proton NMR) is shown in table 1. This example provides an olefinic composition characterization of the intermediate PAO dimer formed in the first step of the process of the present invention.

TABLE 1

Olefin type	Mass% of olefin in dimer mixture
		Vinylidene radical	29％
Tri-substituted vinylidene	60％
		Di-substituted vinylidene	11％

Example 2

The reactor effluent from example 1 was distilled to remove unreacted 1-decene and separate the olefin fraction. The different olefin fractions were each hydrogenated in a stainless steel Parr reactor using 0.5 wt% nickel oxide catalyst at 232 ℃ and 2413kPa (350psi) hydrogen for 2 hours. The properties of each hydrogenated fraction are shown in table 2. This example demonstrates that the intermediate PAO fraction has excellent properties in addition to the intermediate PAO dimer.

TABLE 2

The reported yield corresponds to the mass% of the reactor effluent; 6% of the reactor effluent was monomer.

Example 3

The mPAO dimer portion from the reaction using the procedure of example 1 (and thus having the properties/components listed above) and with 1-decene prior to any hydrogenation of the dimer was used with BF using butanol and butyl acetate in a stainless steel Parr reactor ₃ Complex promoted BF ₃ The catalyst is oligomerized. The intermediate PAO dimer and 1-decene monomer were supplied in a dimer to monomer mass ratio of 2: 1. The reactor temperature was 32 ℃ and BF ₃ A partial pressure of 34.47kPa (5psi) and a catalyst concentration of 30mmol catalyst per 100 grams of feed. The catalyst and feed were stopped after one hour and the reactor contents were allowed to react for one hour. Samples were then collected and analyzed by GC. Table 3 compares the conversion of intermediate PAO dimer with the conversion of 1-decene. Table 4 gives the performance and yield of the PAO codimers resulting from the reaction of LAO and intermediate PAO dimers.

The data in tables 3 and 4 demonstrate that the intermediate PAO dimer of example 1 is highly reactive in lewis acid catalyzed oligomerization and that it produces a codimer with excellent properties. Because 1-decene dimer has the same carbon number as the intermediate mPAO dimer, it is difficult to accurately determine how much intermediate mPAO dimer is converted. Table 3 lists the minimum amount of intermediate PAO dimer converted (assuming all dimers in the reactor effluent are unreacted intermediate PAO) and the estimated amount converted (calculated by assuming that only the linear portion of the dimer GC peak is unreacted intermediate PAO dimer and the other portion is formed by dimerization of 1-decene).

The codimer (C30) fraction was obtained by distilling the oligomerization mixture. The NMR spectrum of the codimer shows the following composition: 4% vinylidene, 77% tri-substituted olefin and 19% tetra-substituted olefin.

Example 4

The procedure of example 3 was followed except that the unhydrogenated intermediate PAO dimer moiety was reacted with 1-octene instead of 1-decene. The results are shown in tables 3 and 4 below. Since 1-octene dimers have a different carbon number than intermediate PAO dimers, no estimate is needed to measure the conversion of intermediate PAO dimers.

Example 5

The procedure of example 3 was followed except that the unhydrogenated intermediate PAO dimer moiety was reacted with 1-dodecene instead of 1-decene. The results are shown in tables 3 and 4 below.

TABLE 3

Example 6

Use of BF with butanol and butyl acetate in a stainless Steel Parr reactor ₃ Complex promoted BF ₃ The catalyst oligomerizes trimers from 1-decene. The reactor temperature was 32 ℃ and BF ₃ A partial pressure of 34.47kPa (5psi) and catalyst concentration of 30mmol catalyst per 100 grams of feed. The catalyst and feed were stopped after one hour and the reactor contents were allowed to react for one hour. These are the same conditions used in the reactions of examples 3-5, except that 1-decene was supplied to the reactionReactor without any intermediate PAO dimer. A sample of the reaction effluent was then collected and analyzed by GC. Table 4 shows the properties and yields of the resulting PAO trimer. This example can be used to show a comparison between the acid-based oligomerization process with pure LAO feed (example 6) versus the same process with a mixed feed of the present invention intermediate mPAO dimer and LAO from example 1 (examples 3-5). The addition of the intermediate mPAO dimer contributes to higher trimer yield, and this trimer has improved VI and Noack volatility.

TABLE 4

Example 7

Using AlCl ₃ The catalyst the intermediate mPAO dimer from the reaction using the procedure and catalyst system of example 1 was oligomerized with 1-octene and 1-dodecene in a five liter glass reactor. The intermediate mPAO dimer moiety comprises 5 mass% of the total LAO and dimer feed streams. The reactor temperature was 36 ℃, the pressure was atmospheric, and the catalyst concentration was 2.92% of the total feed. The catalyst and feed were stopped after three hours and the reactor contents were allowed to react for one hour. Samples were then collected and analyzed. Table 5 shows the amount of dimer in the reactor effluent (i.e., the new dimer formed, and the residual intermediate dimer) as measured by GC and the molecular weight distribution of the effluent as determined by GPC.

Example 8

1-octene and 1-dodecene were fed to the reactor without any intermediate mPAO dimer, following the same conditions and catalyst used in example 7. Table 5 shows the amount of dimer in the reactor effluent and the molecular weight distribution of the effluent. Comparative examples 7 and 8 show that: the addition of the intermediate mPAO dimer with high tri-substituted vinylidene content to the acid catalyst process results in a product with similar molecular weight distribution but with less dimer present; lower dimer levels are a commercially preferred result due to the limited use of dimers as lubricant base stocks.

TABLE 5

Examples	Dimer (% by mass)	Mw/Mn	Mz/Mn
				7	0.79	1.36	1.77
8	1.08	1.36	1.76

Example 9

1-decene, 97% pure, was fed to a stainless steel Parr reactor where it was sparged with nitrogen for 1 hour to obtain a purified feed. The purified stream of 1-decene was then fed to a stainless steel Parr reactor at a rate of 2080 g/hr for oligomerization. The oligomerization temperature was 120 ℃. The catalyst was catalyst 1 prepared in a catalyst solution comprising purified toluene, tri-n-octylaluminum (TNOA), and activator 1. The formulation of the catalyst solution is provided below, based on 1 gram of catalyst 1:

the 1-decene and catalyst solution were fed into the reactor at a ratio of 31,200 grams 1-decene per gram of catalyst solution. Additional TNOA was also used as a scavenger to remove any polar impurities and added to the LAO at a ratio of 0.8 grams of 0.25% TNOA in toluene per 100 grams of purified 1-decene. The residence time in the reactor was 2.8 hours. The reactor was operated at full liquid conditions (without any gas addition). When the system reached steady state, a sample was taken from the reactor effluent and the composition of the crude polymer was determined by GC. The percent conversion of 1-decene was calculated from the GC results and is shown in table 6. The kinematic viscosity of the intermediate PAO product (after monomer removal) was measured at 100 ℃.

Example 10

The procedure of example 9 was followed except that the reactor temperature was 110 ℃.

Example 11

The procedure of example 9 was followed except that the reactor temperature was 130 ℃.

Example 12

The procedure of example 9 was followed except that the residence time in the reactor was 2 hours and the catalyst amount was increased to 23,000 grams LAO per gram of catalyst to achieve a similar conversion to the above example.

Example 13

The procedure of example 9 was followed except that the residence time in the reactor was 4 hours and the catalyst amount was reduced to 46,000 grams LAO per gram of catalyst to achieve a similar conversion to the above example.

Example 14

The procedure of example 9 was followed except that the reactor was operated in semi-batch mode (feed streams were added continuously until the desired amount was reached and then the reaction was allowed to continue without addition of a new feed stream) and the catalyst used was bis (1-butyl-3-methylcyclopentadienyl) zirconium dichloride (hereinafter "catalyst 2") which had been alkylated with octyl by TNOA. In this example, the conversion of LAO was only 44%. No kinematic viscosity at 100 ℃ is reported due to low conversion.

TABLE 6

Example 15

Dimers are formed using a similar process as described in U.S. patent No. 4,973,788. The LAO feed was 1-decene and TNOA was used as the catalyst. The contents were reacted in a stainless steel Parr reactor at 120 deg.C and 172.37kPa (25psi) for 86 hours. The dimer product fraction was thereafter separated from the reactor effluent via distillation and analyzed for composition via proton-NMR and provided in table 7.

TABLE 7

Vinylidene radical	96％
		Di-substituted olefins	4％
Tri-substituted olefins	0％

This C20 dimer fraction was then contacted with a 1-octene feedstock and a butanol/butyl acetate promoter system in a second stainless steel Parr reactor. The molar dimer to LAO feed ratio was 1:1, the molar butanol to butyl acetate feed ratio was 1:1, and the promoter was supplied at a ratio of 30mmol/100 g LAO. The reaction temperature was 32 ℃ and BF providing acid catalyst ₃ At a partial pressure of 34.47kPa (5psi), the feed time was one hour, and then the contents were allowed to react for another hour. A sample was then taken from the product stream and analyzed via GC. The compositions are provided in table 8 below. Applicants believe that the dimer formation and other feedstocks used in this example 15 are in accordance with the various examples of U.S. Pat. No. 6,548,724The dimer composition used in this was similar to the starting material.

Example 16

This example is based on the intermediate mPAO dimer resulting from the reaction using the procedure and catalyst system of example 1; the resulting intermediate mPAO dimer has the same composition as given in table 1. The intermediate mPAO dimer moiety is reacted in a second reactor under the same feed and process conditions as the second oligomerization of example 15. A sample of the PAO prepared by the second oligomerization was taken from the product stream and analyzed for its composition via GC and the analysis is provided in table 8 below (note that this example is a repeat of example 4; the analytical data is substantially similar for this second batch of the same reaction and the resulting PAO is obtained from oligomerizing predominantly tri-substituted olefins).

TABLE 8

Second reactor effluent	Example 15	Example 16
			Unreacted monomer	0.3％	0.7％
The lighter fraction	22.0％	13.2％
			C 28 Fraction(s) of	59.0％	72.5％
Heavier fraction	18.7％	13.6％

By using an intermediate dimer comprising predominantly tri-substituted olefin instead of an intermediate dimer comprising predominantly vinylidene olefin, the yield of the C28 fraction increased from 59.0% & gt to 72.5%. Thus, the use of intermediate PAO dimers comprising predominantly tri-substituted olefins is significantly superior to dimers comprising predominantly vinylidene due to the significant increase in yield of the C28 co-dimer product that is commercially valuable for low viscosity applications.

Example 17

Example 17 was prepared in the same manner as example 15 except that the LAO feedstock for the acid-based oligomerization in the second reactor was 1-decene instead of 1-octene. The applicants believe that the dimer composition and other starting materials used in example 17 are also similar to the dimer composition and starting materials used in the various examples in U.S. patent No. 6,548,724. A sample was taken from the product stream of the second reactor and analyzed via GC, and the composition is provided in table 9 below.

Example 18

Example 18 was performed the same as example 16 except that the LAO feed in the second reactor was 1-decene instead of 1-octene. A sample was taken from the product stream of the second reactor and analyzed. The overall composition of the reactor PAO product is provided in table 9 below. The C30 fraction had about 21% tetra-substituted olefins as determined by carbon-NMR prior to hydrogenation; the remaining structure is a mixture of vinylidene and tri-substituted olefins.

TABLE 9

Examples 17 and 18 show that, again, the use of a dimer intermediate comprising predominantly tri-substituted olefin increases the yield of the desired C30 product. Since the carbon numbers of the co-dimer and the C10 trimer were the same in these experiments, it was not feasible to quantify the amounts of co-dimer and C10 trimer separately. Instead, the C30 material was isolated via distillation and the product properties of examples 17 and 18 were measured.

For comparison purposes, from BF ₃ Oligomerization to obtain C10 trimer, where the trimer was obtained using the procedure described above for the second reactor of examples 17 and 18; i.e., there was no first reaction with TNOA or catalyst 1, and therefore, there was no dimer feed element in the acid catalyst oligomerization. The properties of this C10 trimer were measured and are summarised in table 10 and compared with the C30 trimer of examples 17 and 18.

TABLE 10

Table 10 demonstrates that at BF ₃ C30 material formed using tri-substituted vinylidene dimer feed element in oligomerization (example 18) vs. BF ₃ The apparent difference between the C30 materials formed using vinylidene dimer feed element in oligomerization (example 17). The C30 material obtained using the tri-substituted vinylidene dimer had a viscosity similar to that of the C30 material obtained using the vinylidene dimer under comparable process conditions with a significantly improved VI and lower Noack volatility. In addition, the C30 material obtained using vinylidene dimer has a much more similar behavior to BF compared to the C30 material obtained using tri-substituted vinylidene dimer ₃ Performance of those of the C10 trimer in the process, indicating that the greater part of the C30 yield is the C10 trimer rather than the codimer of vinylidene dimer and 1-decene.

Example 19

Example 19 was prepared using the catalyst system and process steps of example 1 except that the starting LAO feed was 97% pure 1-octene and the oligomerization temperature was 130 ℃. When the system reached steady state, a sample was taken from the reactor effluent and fractionated to obtain a C16 olefinic portion (1-octene dimer) of approximately 98% purity. This intermediate PAO dimer was analyzed by proton NMR and had a tri-substituted olefin content of greater than 50%.

Then use BF ₃ The catalyst and butanol/butyl acetate promoter system oligomerizes this intermediate mPAO dimer moiety with 1-dodecene in the second reactor. The intermediate mPAO dimer was fed at a 1:1 molar ratio to 1-dodecene and the catalyst concentration was 30mmol catalyst per 100 grams of feed. The reactor temperature was 32 ℃. After one hour the catalyst and feed were stopped and the reactor contents allowed to react for an additional hour. Samples were then collected, analyzed by GC (see table 12), and fractionated to obtain a C28 fraction of approximately 97% purity. Partially hydrogenating the C28 olefin and analyzing its properties; the results are shown in Table 11.

Example 20

Similar to example 19, except that the prepared intermediate mPAO C16 dimer moiety was oligomerized with 1-tetradecene, but not 1-dodecene. A sample was collected from the second reactor and analyzed for fraction content by GC (see table 12). The C30 olefin portion of the effluent was obtained via conventional distillation means and the trimer was hydrogenated and analyzed for properties; the results are shown in Table 11.

Example 21

Similar to example 19, except that the intermediate mPAO C16 dimer moiety prepared was oligomerized with 1-hexadecene instead of 1-dodecene in the subsequent step of preparing the C32 trimer. Samples were collected from the second reactor and analyzed for fraction content by GC (see table 12). The C32 olefin portion of the effluent was obtained via conventional distillation means and the trimer was hydrogenated and analyzed for properties; the results are shown in Table 11.

Example 22

Example 22 was prepared using the catalyst system and process steps of example 1 except that the LAO feed was 97% pure 1-dodecene and the oligomerization temperature was 130 ℃. When the system reached steady state, a sample was taken from the reactor effluent and fractionated to obtain a C24 olefin (1-dodecene dimer) fraction of approximately 98% purity. This intermediate mPAO dimer was analyzed by proton NMR and had a tri-substituted olefin content of greater than 50%.

Then use BF ₃ Catalyst and butanol/butyl acetate promoter systemThe C24 intermediate mPAO dimer moiety was oligomerized with 1-hexene in two reactors. The C24 intermediate PAO dimer was fed in a 1:1 molar ratio to 1-hexene and the catalyst concentration was 30mmol catalyst per 100 grams of feed. The reactor temperature was 32 ℃. After one hour the catalyst and feed were stopped and the reactor contents allowed to react for an additional hour. A sample was then collected, analyzed by GC (see table 12), and fractionated to obtain a C30 olefin fraction of approximately 97% purity. The C30 olefins were partially hydrogenated and analyzed for properties, the results are shown in table 11.

Example 23

Similar to example 22, except that the intermediate mPAO dimer moiety prepared in the first reaction was then oligomerized with 1-octene, rather than 1-hexene, in a subsequent acid-based oligomerization step to produce C32 olefins. The results are shown in Table 11.

Example 24

Example 24 was prepared using the same procedure and catalyst system as example 1, except that the first oligomerization temperature was 130 ℃. When the system reached steady state, a sample was taken from the reactor effluent and fractionated to obtain the C20 intermediate mPAO dimer moiety of approximately 98% purity. The distilled dimer was analyzed by proton NMR and had a tri-substituted olefin content of greater than 50%.

Then use BF ₃ The catalyst and butanol/butyl acetate promoter system oligomerizes the C20 intermediate mPAO dimer moiety with 1-decene in a second reactor. The intermediate mPAO dimer was fed at a 1:1 molar ratio to 1-decene and the catalyst concentration was 30mmol catalyst per 100 grams of feed. The reactor temperature was 32 ℃. After one hour the catalyst and feed were stopped and the reactor contents allowed to react for an additional hour. A sample was then collected, analyzed by GC (see table 12), and then fractionated to obtain a C30 olefin fraction with a purity of approximately 97%. Partially hydrogenating the C30 olefin and analyzing; the results are shown in Table 11. The applicant notes that this example 24 is similar to example 3, the only difference being the first reaction temperature. A comparison of the data in table 4 and table 11 shows that for the higher first reaction temperature of example 24, the kinematic viscosity and VI are comparable and the pour point decreases with a slight increase in Noack volatility.

Example 25

Similar to example 24, except that the intermediate mPAO dimer moiety prepared was oligomerized with 1-octene, rather than 1-decene, in a subsequent reaction step to prepare C28 olefin. The results are shown in Table 11. This data is comparable to example 4 with substantially similar product results, even though the temperature in the first reactor was increased for example 25.

Example 26

Similar to example 24, except that the intermediate PAO dimer fraction prepared was oligomerized with 1-dodecene, not 1-decene, in a subsequent reaction step to prepare C32 olefins. The results are shown in Table 11. This data is comparable to example 5 with substantially similar product results, even though the temperature in the first reactor was increased for example 26.

TABLE 11

TABLE 12

Additional advantages to the present invention are apparent in comparing the performance and yield of each example. For example, comparing examples 19-21 to their carbon number equivalents in examples 24-26 shows that molecules with equal carbon numbers in each example have similar properties. However, the processes of examples 19-21 resulted in yields of the desired product that were approximately 20% higher than the processes of examples 24-26. Furthermore, comparing examples 22 and 23 with their carbon number equivalents in examples 24 and 26 shows that the products of the invention show higher Vis at similar kinematic viscosities.

Functional fluid examples

Various functional fluids were prepared and tested for performance using a low viscosity binder. The low viscosity base stocks are listed in table 13 below, and the functional fluids formulated as transmission fluids are listed in table 14 below. In Table 13, "PAO-3.4" is a low viscosity PAO binder having a KV100 of 3.4cSt prepared by the method described in example 9 above; "PAO-3.5" is a low viscosity PAO binder having a KV100 of 3.5cSt prepared by the method described in example 18 above; PAO-4 is a commercial PAO binder having a KV100 of 4.0cSt made by oligomerizing linear alpha-olefins in the presence of a Lewis acid catalyst, available from ExxonMobil chemical company, located at 4500Bayway Drive, Baytown, TX 77450; and GTL-4 is a commercial GTL base stock available from Shell Oil Company with a KV100 of about 4.0 cSt. Group III base stock is Yubase4, a commercial base stock available from SK Lubricants Co., Ltd. address 26, Jongro, Jongro-Gu, Seoul 03188, Korea. Group III + base stock is Yubase 4+, a commercial feedstock also available from SK Lubricants co.

Watch 13

As can be seen from Table 13, the PAO-3.4 and PAO-3.5 base stocks had CCSV at-30 ℃ and-35 ℃, and HTHSV values significantly lower than those of PAO-4 and GTL-4. In addition, the PAO-3.4 and PAO-3.5 base stocks have a much higher RPVOT value than the PAO-4 and GTL-4 base stocks. The PAO-3.5 and PAO-3.4 base stocks had NV values comparable to PAO-4. All of these exceptional properties of the PAO-3.4 and PAO-3.5 bases make them high grade bases for transmission fluids, particularly hybrid engine transmission fluids where the transmission fluid is exposed to high temperature electric motors. In addition, the PAO-3.4, PAO-3.5, and PAO-4 base stocks all have pour points well below GTL-4. In summary, the PAO-3.4 base made from the metallocene catalyzed process, and the PAO-3.5 base made from the hybrid process comprising a metallocene catalyzed oligomerization step to make dimers, followed by a lewis acid catalyzed oligomerization between the dimers and LAO monomers, are much better bases for high quality transmission fluids and other functional fluids than commercial GTL and conventional PAO bases having similar KV 100.

Transmission fluids 1,2, 3 and 4

Functional fluids contemplated as transmission fluids were formulated and tested from PAO-3.4, PAO-3.5, PAO-4, and GTL-4 base stocks. The compositions and properties are provided in table 14 below. In this table, HiTec 3419D is a commercial additive package available from Afton Chemical Corporation, located at 500Spring Street, Richmond, VA 23219, u.s.a.

TABLE 14

As can be seen from Table 14 above, fluids 1 and 2 formulated with PAO-3.4 and PAO-3.5 base stocks, respectively, exhibit much superior low temperature properties, i.e., much lower Brookfield viscosities, CCSV at-25 ℃, -30 ℃ and-35 ℃, and much lower MRV apparent viscosity values at-30 ℃ and-35 ℃, compared to fluids 3 and 4 formulated with commercial PAO-4 and GTL-4 base stocks, respectively. Additionally, fluids 1 and 2 exhibit a much lower 150 ℃ HTHSV than fluids 3 and 4, indicating superiority and lower viscosity at high temperatures and high shear in the transmission.

The functional fluids in table 14 above were then tested for low traction performance under the following micro traction machine ("MTM") test conditions: loading: 30 newtons; speed: 2m/s, and a slide roll ratio ("SRR"): 0 to 70 percent. The test results are shown in fig. 1. As can be seen, fluids 1 and 2 based on PAO-3.4 and PA-3.5 base stocks, respectively, exhibit superior low traction performance relative to fluids 3 and 4 based on conventional PAO-4 and GTL-4, respectively, which can result in higher energy efficiency and better fuel economy.

The above fluids 1-4 were then tested for oxidative stability at 170 ℃ for 192/384 hours according to CEL L48. The test results are reported in table 15 below. In this table, "PDSC" refers to a pressure differential scanning calorimeter and "Δ KV" refers to the change in kinematic viscosity at the end of the test period.

Watch 15

As can be seen from the test data in table 15 above, fluids 1 and 2 exhibit superior oxidative stability in many respects over fluids 3 and 4. In particular, fluids 1 and 2 showed much longer PDSC times than fluids 3 and 4. Fluids 1 and 2 showed much lower Δ KV at 40 ℃ and 100 ℃ after 384 hours compared to fluids 3 and 4. Fluids 1 and 2 showed much lower Δ KV at 40 ℃ and 100 ℃ after 192 hours compared to fluid 3. Fluids 1 and 2 showed much lower oxidation by FT-IR after 384 hours compared to fluids 3 and 4.

Clutch fluids 5, 6 and 7

A series of clutch fluids (fluids 5, 6 and 7) were formulated from the above-described PAO-3.4 base stock, and/or commercial group II, II +, III and III + base stocks, and tested. Fluid 5 is the same as fluid 1. The compositions and test data are provided in table 16 below. Clearly, fluid 5 made from the PAO-3.4 basestocks exhibited much lower pour point and Brookfield viscosity at-40 deg.C, as well as Noack volatility at 200 deg.C and 250 deg.C, as compared to fluids 6 and 7 made from group II, II +, III and III + basestocks, which is highly desirable for clutch fluids.

TABLE 16

Fluids 5, 6 and 7 were then tested for Dexron clutch wear life. The test results are provided in fig. 2. As is evident from FIG. 2, fluid 5 exhibited much superior clutch life performance compared to fluids 6 and 7, indicating the superiority of the PAO-3.4 base stock over the group II, II +, III, and III + base stocks in formulating clutch fluids. The high performance of fluid 5 achieved by the PAO-3.4 base may help deliver smoother torque transfer, driver comfort, and higher clutch system life compared to fluids 6 and 7 formulated from group II, II +, III, and III + bases.

Industrial gear oil fluids 8 and 9

From a high viscosity PAO base, namely SpectraSyn Elite ^TM 150 ("mPAO-150"), a PAO base stock available from ExxonMobil Chemical Company having a KV100 of about 150cSt, an ester base stock, Esterex A51 (also available from Exxo)Obtained from nMobil Chemical Company) and the PAO-3.4 base described above or a conventional PAO base having a KV100 of about 6cSt were formulated into two industrial gear oil fluids (fluids 8 and 9). The compositions of streams 8 and 9 are provided in table 17 below. The two fluids were then tested for traction coefficients at 80 ℃ and 120 ℃ and the test results are provided in fig. 3 and 4. As is evident, fluid 9, which contains PAO-3.4, exhibits lower tractive effort at these two temperatures than fluid 8. Thus, fluid 9 will exhibit higher energy efficiency as an industrial gear oil than fluid 8. Thus, the PAO-3.4 base stock helps to improve traction and therefore energy efficiency and fuel economy when formulated with a high viscosity base stock into an industrial gear oil fluid at low treat rates as compared to conventional low viscosity PAO base stocks.

TABLE 17

Claims (29)

1. A functional fluid for a clutch, gearbox, transmission, motor or battery, comprising a saturated polyalphaolefin ("PAO") first base stock in a concentration range of 3 wt% to 98 wt% thereof, the first base stock having, based on the total weight of the functional fluid:

kinematic viscosity at 100 ℃ (KV 100) of 3.0-3.6cSt, determined according to ASTM D445;

a Noack volatility ("NV") of no greater than 15% as determined according to ASTM D5800;

0.11-0.16 watt-meter ^-1 ·K ^-1 Thermal conductivity at 40 ℃; and

a high temperature high shear viscosity ("HTHSV") of at most 1.4 centipoise as measured according to ASTM at 150 ℃.

2. The functional fluid of claim 1 wherein the first binder has a kinematic viscosity at 100 ℃ ("KV 100") of 3.5cSt or less as determined by ASTM D445.

3. The functional fluid of claim 1 wherein the first binder has a Noack volatility ("NV") of 12.5% or less as determined in accordance with ASTM D5800.

4. The functional fluid of claim 1 or claim 2 or claim 3 comprising the first binder in a concentration range of 50 wt% to 98 wt% thereof, based on the total weight of the functional fluid.

5. The functional fluid of claim 1 or claim 2 or claim 3 wherein the first base stock comprises C28-C32 polyalphaolefin oligomer at a concentration of at least 95 weight percent, based on the total weight of the first base stock.

6. The functional fluid of claim 5 wherein the first binder comprises C30 polyalphaolefin oligomer at a concentration of at least 95 weight percent, based on the total weight of the first binder.

7. The functional fluid of claim 1 or claim 2 or claim 3 wherein the first base stock comprises, in a total concentration of at least 80 wt% thereof, polyalphaolefin oligomers having the formula:

wherein each R is independently n-butyl, n-hexyl, n-octyl, n-decyl, or n-dodecyl.

8. The functional fluid of claim 1 or claim 2 or claim 3 wherein the first binder has a cold start simulator viscosity ("CCSV") of no greater than 1,000 centipoise measured at-35 ℃ according to ASTM D4683.

9. The functional fluid of claim 1 or claim 2 or claim 3 further comprising a second binder of group I, II, III, IV, or V in a concentration range of from 0 to 97 weight percent, based on the total weight of the functional fluid, and one or more additives in a total concentration range of from 0 to 20 weight percent, based on the total weight of the functional fluid.

10. The functional fluid of claim 1 or claim 2 or claim 3 having a KV100 of from 3.5 to 4.2cSt, and a Noack volatility of from 10 to 13 wt%.

11. The functional fluid of claim 1 or claim 2 or claim 3 which is a hybrid vehicle transmission fluid and/or an electric motor cooling fluid and/or a battery pack cooling fluid.

12. The functional fluid of claim 1 or claim 2 or claim 3 wherein at least a portion of the first binder is prepared by a method selected from the group consisting of:

(i) a first process comprising oligomerizing one or more C6-C14 alpha-olefins in the presence of a catalyst system comprising a metallocene compound to obtain a first oligomer mixture, separating a first unhydrogenated precursor to be the first base stock from the oligomer mixture, and then hydrogenating the first unhydrogenated precursor; and

(ii) a second process comprising preparing a second oligomer of one or more C6-C14 alpha-olefins in the presence of a catalyst system comprising a metallocene compound, reacting the second oligomer with one or more C6-C14 alpha-olefins in the presence of a lewis acid catalyst to obtain a third oligomer mixture, separating from the third oligomer mixture a second unhydrogenated precursor to be the first base stock, and then hydrogenating the second unhydrogenated precursor.

13. The functional fluid of claim 12 where in method (ii) the second oligomer consists essentially of dimers of one or more α -olefins.

14. The functional fluid of claim 13 wherein said first binder is prepared by process (ii), wherein said dimer comprises at least 20 weight percent of one or more tri-substituted olefins, based on the total weight of said dimer.

15. The functional fluid of claim 14 wherein said dimer comprises >40 weight percent of one or more tri-substituted olefins, based on the total weight of said dimer.

16. The functional fluid of claim 14 wherein said dimer comprises >50 weight percent of one or more tri-substituted olefins, based on the total weight of said dimer.

17. The functional fluid of claim 12 wherein the first binder is prepared from monomers consisting essentially of 1-decene.

18. The functional fluid of claim 13 wherein the first binder is prepared by process (ii), wherein the second unhydrogenated precursor comprises at least 50 weight percent of one or more tetra-substituted olefins or tri-substituted olefins, based on the total weight of the separated precursors.

19. The functional fluid of claim 18 wherein the second unhydrogenated precursor comprises at least 80 weight percent of one or more tetra-substituted olefins or tri-substituted olefins, based on the total weight of the separated precursors.

20. A method for lubricating and/or cooling an engine transmission, gearbox, clutch, electric motor or battery pack, comprising:

(I) providing a functional fluid comprising a saturated polyalphaolefin ("PAO") first base stock in a concentration range of 3 wt% to 98 wt% thereof, the first base stock having, based on the total weight of the functional fluid:

kinematic viscosity at 100 ℃ (KV 100) of 3.0-3.6cSt, determined according to ASTM D445;

a Noack volatility ("NV") of no greater than 15% as determined according to ASTM D5800;

0.11-0.16 watt-meter ^-1 ·K ^-1 Thermal conductivity at 40 ℃;

a high temperature high shear viscosity ("HTHSV") of at most 1.4 centipoise as measured according to ASTM at 150 ℃; and

(II) contacting the functional fluid with the engine transmission, the gearbox, the clutch, the electric motor, or the battery pack.

21. The method of claim 20, wherein the first binder has a kinematic viscosity at 100 ℃ ("KV 100") of ≦ 3.5cSt determined according to ASTM D445.

22. The method of claim 20, wherein the first binder has a Noack volatility ("NV") of 12.5% or less as determined by ASTM D5800.

23. The method of claim 20 or claim 21 or claim 22, wherein step (II) comprises contacting the functional fluid with both an engine transmission and an electric motor in a hybrid vehicle.

24. The process of claim 20 or claim 21 or claim 22, wherein step (I) comprises one or both of the following methods:

(i) oligomerizing one or more C6-C14 alpha-olefins in the presence of a catalyst system comprising a metallocene compound to obtain a first oligomer mixture, separating a first unhydrogenated precursor to be the first base stock from the oligomer mixture, and then hydrogenating the first unhydrogenated precursor; and

(ii) preparing a second oligomer of one or more C6-C14 alpha-olefins in the presence of a catalyst system comprising a metallocene compound, reacting the second oligomer with one or more C6-C14 alpha-olefins in the presence of a lewis acid catalyst to obtain a third oligomer mixture, separating a second unhydrogenated precursor to be the first base stock from the third oligomer mixture, and then hydrogenating the second unhydrogenated precursor.

25. The process of claim 24, wherein the one or more C6-C14 α -olefins consist essentially of 1-decene.

26. The process of claim 20 or claim 21 or claim 22, wherein the first base stock comprises C28-C32 polyalphaolefin oligomer at a concentration of at least 95 weight percent, based on the total weight of the first base stock.

27. The process of claim 20 or claim 21 or claim 22, wherein the first base stock comprises, in a total concentration of at least 80 wt% thereof, polyalphaolefin oligomers having the formula:

wherein each R is independently n-hexyl, n-octyl, or n-decyl.

28. The method of claim 20 or claim 21 or claim 22, wherein the first base stock has a cold start simulator viscosity ("CCS") of no greater than 1,000 centipoise measured according to ASTM D4683 at-35 ℃.

29. The method of claim 20 or claim 21 or claim 22, wherein the functional fluid has a KV100 of from 3.5 to 4.2cSt and an NV of from 10 to 13 wt%.

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