Heat transfer fluids comprising isomeric branched paraffin dimers derived from linear alpha-olefins and uses thereof

Abstract

A branched paraffin formed as a hydrogenation reaction product of one or more linear alpha-olefins (LAOs) oligomerized with a BF3 catalyst system and comprising at least about 90 wt% branched paraffin dimers can have advantageous heat transfer properties. The heat transfer fluid comprising the branched paraffin is disposed in contact with a heat-generating component, such as those found in an electrically powered vehicle, a battery system, or other system requiring thermal management. Branched paraffin dimers formed from one or more LAOs having from about 8 to about 12 carbon atoms can collectively have a Mouromtseff number of about 10,000 to about 16,000 kg / (s 2.2 .m 0.6 .K) at 80°C, a thermal conductivity of about 0.125 W / m.K or more at 80°C, and a flash point of about 140°C or more.

Description

[0001] priority

[0002] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 089,501, filed on October 8, 2020, the disclosure of which is incorporated by reference in its entirety into this application. Technical Field

[0003] The present disclosure relates to heat transfer fluids and methods of producing and using the same. Background Art

[0004] In the electric vehicle industry, many advances have been made in battery technology in recent years to facilitate greater power delivery and reduced charging frequency. One of the advances needed to further advance electric vehicle technology is the development of more efficient cooling systems for facilitating heat transfer from various electric vehicle (EV) components. Specific components of an electric vehicle that may require improved heat transfer include, for example, one or more batteries, axles, EV power electronics, and / or electric motors. Fast charging stations for electric vehicles may similarly require efficient cooling. While components of an electric vehicle can be cooled to varying degrees using conventional jacket cooling fluids and techniques (such as glycol aqueous solutions also used in combination with internal combustion engines), effectively cooling the batteries of an electric vehicle by direct cooling fluid contact represents an entirely different challenge.

[0005] All batteries generate heat when charging or discharging. The faster the charge or discharge rate becomes, the more heat is generated per unit time. For small batteries, exposure to the ambient atmosphere can effectively dissipate the released heat, eliminating the need for a separate cooling system. In electric vehicles, the large battery sizes and rapid discharge rates required to ensure satisfactory vehicle performance make heat dissipation a more significant issue. Similarly, rapid battery charging at electric vehicle recharging stations can also result in significant battery heating and present similar thermal management issues.

[0006] In addition to affecting or determining vehicle performance, battery temperatures outside of the preferred operating range, which is typically about 15°C to 35°C for lithium-ion batteries, can negatively impact battery performance. Internal temperature gradients between battery cells can similarly impact battery performance. Furthermore, in addition to poor battery or vehicle performance, using a battery outside of the preferred temperature range and / or with internal thermal gradients can increase the risk of battery failure, uncontrolled overheating, fire, and / or explosion. Consequently, effective thermal management during battery charging or discharging and vehicle operation can become a limiting factor in how much further electric vehicle performance can be improved.

[0007] Current battery cooling strategies for electric vehicles can employ one or more of phase change materials, heat sink fins, or air cooling. Each of these methods has significant limitations in the amount of heat they can dissipate directly from the battery, and / or due to their impact on vehicle performance. For example, heat sink fins result in the vehicle having to carry excess weight while the vehicle is in motion, thereby reducing the efficiency and performance of the vehicle.

[0008] Cooling systems employing heat transfer fluids are another heat dissipation strategy that can be used for batteries and other heat generating components of electric vehicles. Because fluids can exhibit higher thermal conductivity and heat capacity values than air, fluids can facilitate heat dissipation from batteries or other heat generating components more effectively than other heat dissipation strategies. In addition, fluids can be placed in direct surface contact with batteries, electric motors, or other heat generating components to facilitate optimal heat transfer, including arrangements in which the heat generating components are partially or completely submerged in the heat transfer fluid. For example, such direct immersion cooling can help reduce the risk of uncontrolled thermal runaway within a battery module where one cell is damaged due to a short circuit or physical damage. Alternatively, a suitable heat transfer fluid can be jacketed around and / or circulated through a heat generating component, such as a battery or EV power component. While submerging a heat generating component in or partially in a heat transfer fluid can provide optimal heat transfer, many heat transfer fluids that are currently in common use are not suitable for submerging batteries and / or electric motors in them due to the electrical conductivity of the fluid. Aqueous heat transfer fluids, such as glycol water solutions, can not be suitable for submerging in batteries or electric motors because the high electrical conductivity can cause short circuits and battery or motor failure, which can occur when the heat transfer fluid contacts battery leads or various electrical components in the motor. Fluorocarbon fluids can meet certain performance requirements for a suitable heat transfer fluid, including satisfactory pour point and flash point values, but the smoke from fluid combustion can cause undesirable health and environmental impacts. To date, a suitable insulating heat transfer fluid with acceptable heat transfer characteristics combined with acceptable flash point, pour point, and health / environmental features has yet to be identified.

[0009] In addition to the growing need for improved heat transfer fluids for the electric vehicle industry, there is also a significant need for effective thermal management in emerging technologies such as data centers and server farms, high power electronics, and 5G communication systems. Various application-specific needs can dictate the specific formulation requirements of the heat transfer fluids used in these and other applications. SUMMARY

[0010] In some embodiments, the present disclosure provides a heat transfer fluid comprising a plurality of isomerically branched paraffins comprising a hydrogenation reaction product of one or more linear alpha-olefins (LAOs) oligomerized with a BF3 catalyst system, the plurality of isomerically branched paraffins comprising at least about 90 wt% isomerically branched paraffin dimers. The one or more LAOs have from about 8 to about 12 carbon atoms. The plurality of isomerically branched paraffins collectively have a Mouromtseff number in the range of about 10,000 to about 16,000 kg / (s 2.2 ·m 0.6 ·K) at 80°C, a thermal conductivity of about 0.125 W / m-K or greater at 80°C, and a flash point of about 140°C or greater.

[0011] In other embodiments, the present disclosure provides a battery system comprising a heat transfer fluid. The battery system includes a battery and a heat transfer fluid in contact with the battery. The heat transfer fluid comprises a plurality of isomerically branched paraffins comprising a hydrogenation reaction product of one or more linear alpha-olefins (LAOs) oligomerized with a BF3 catalyst system, the plurality of isomerically branched paraffins comprising at least about 90 wt% isomerically branched paraffin dimers. The one or more LAOs have from about 8 to about 12 carbon atoms. The plurality of isomerically branched paraffins collectively have a Mouromtseff number in the range of about 10,000 to about 16,000 kg / (s 2.2 ·m 0.6 ·K) at 80°C, a thermal conductivity of about 0.125 W / m-K or greater at 80°C, and a flash point of about 140°C or greater.

[0012] In other embodiments, the present disclosure provides an electric vehicle comprising a heat generating component and a heat transfer fluid in contact with the heat generating component. The heat transfer fluid comprises a plurality of isomerically branched paraffins comprising a hydrogenation reaction product of one or more linear alpha-olefins (LAOs) oligomerized with a BF3 catalyst system, the plurality of isomerically branched paraffins comprising at least about 90 wt% isomerically branched paraffin dimers. The one or more LAOs have from about 8 to about 12 carbon atoms. The plurality of isomerically branched paraffins collectively have a Mouromtseff number in the range of about 10,000 to about 16,000 kg / (s 2.2 ·m 0.6 ·K) at 80°C, a thermal conductivity of about 0.125 W / m-K or greater at 80°C, and a flash point of about 140°C or greater.

[0013] In other embodiments, the present specification provides a method of thermal management utilizing a heat transfer fluid. The method includes providing a heat transfer fluid, and operating or placing a heat generating component in contact with the heat transfer fluid. The heat transfer fluid includes a plurality of isomerically branched paraffins including a hydrogenation reaction product of one or more linear alpha-olefins (LAOs) oligomerized with a BF3 catalyst system, the plurality of isomerically branched paraffins including at least about 90 wt% isomerically branched paraffin dimers. The one or more LAOs have from about 8 to about 12 carbon atoms. The plurality of isomerically branched paraffins collectively have a Mouromtseff number in the range of about 10,000 to about 16,000 kg / (s 2.2 ·m 0.6 ·K) at 80 °C, a thermal conductivity of about 0.125 W / m·K or more at 80 °C, and a flash point of about 140 °C or more. BRIEF DESCRIPTION OF DRAWINGS

[0014] The following drawings are included to illustrate certain aspects of the present specification, and should not be considered exclusive embodiments. The disclosed subject matter can be modified, changed, combined and / or equivalents substituted for other aspects, both in form and in function, as would be obvious to a skilled artisan in the art, having the benefit of the present description.

[0015] Figure 1 A plot of flash point versus Mouromtseff number is shown for various heat transfer fluids.

[0016] Figure 2 A gas chromatogram is shown for isomerically branched paraffin dimers obtained using a BF3 catalyst system. DETAILED DESCRIPTION

[0018] The present invention relates to thermal management, and more specifically, to heat transfer fluids featuring primarily isomerically branched paraffin dimers and related methods thereof. The heat transfer fluids can be used for thermal management in electric vehicles and other places where efficient heat transfer is needed.

[0019] As noted above, effective thermal management in electric vehicles can be challenging, particularly for cooling systems designed to maintain the battery or other electrical components of an electric vehicle within a desired operating temperature range, for example from about 15 °C to about 35 °C in the case of lithium-ion batteries, while also maintaining vehicle performance and high work efficiency. In the absence of effective thermal management, catastrophic failure of the battery and / or vehicle can occur. For example, at battery temperatures above about 140 °C, uncontrolled reactions can occur without effective cooling. To provide a sufficient operating safety margin, a maximum operating temperature of about 70 °C can be used in some cases, and even for short periods of time. If an uncontrolled reaction occurs due to insufficient cooling and / or cooling system failure, the battery temperature can jump to about 700 °C, resulting in a fire. Cooling systems utilizing heat transfer fluids have provided the best thermal management performance to date, but many heat transfer fluids, such as glycol water solutions, are not suitable for direct immersion of the battery or electric motor therein due to the electrical conductivity of the fluid, limiting the amount of heat transfer that can be achieved. As a result, further technological advancements in electric vehicles can be limited by the performance shortcomings of existing heat transfer fluids.

[0020] This specification demonstrates that certain abundant products of the chemical and petroleum industries can be suitable precursors for forming heat transfer fluids that are substantially insulating and have good thermal management properties and other properties that are highly compatible with current use in conjunction with batteries for electric vehicles and for other heat transfer applications. More specifically, linear alpha-olefins (LAOs) can be used as precursors to form branched LAO oligomers in the presence of an acid catalyst system such as BF3and a suitable promoter (a BF3catalyst system), which can then be further hydrogenated to form the corresponding branched paraffins as reaction products. Other acid catalyst systems, such as those comprising AlCl3or BF3complexes and promoters, can also be effective to form LAO oligomers and isomeric branched paraffins produced therefrom for use in the present disclosure. Dimer, trimer, tetramer, and higher oligomers can be produced from the oligomerization of LAOs with a BF3catalyst system. A variety of isomeric branched paraffins of each oligomer size can be formed when LAOs are oligomerized in the presence of a BF3catalyst system, where the isomeric branched paraffins can have branches extending across the entire carbon chain, and the branches can be of various sizes. Although dimers are typically formed as less abundant reaction products (<10% of total oligomers formed) when LAOs are oligomerized in the presence of a BF3catalyst system, the isomeric branched paraffin dimers obtained after distillation and hydrogenation provide surprisingly good heat transfer properties, as further discussed herein. Thus, isomeric branched paraffin dimers can be obtained from the reaction mixture after LAOs are oligomerized with a BF3catalyst system and hydrogenated for use in heat transfer applications, and higher branched paraffin oligomers can be used for other purposes. In fact, isomeric branched paraffin dimers formed during the oligomerization of LAOs with acid catalyst systems have been observed to date as undesirable byproducts, and their formation during LAO oligomerization has been sought to be minimized. This specification demonstrates the new utility of these previously undesirable byproducts.

[0021] LAO oligomerized with a BF3 catalyst system carries hydrocarbon-based branches at any position along the dimer backbone, and can exist with variable size branches. One branch or multiple branches can exist within a given dimer molecule. LAO having from about 8 to about 12 carbon atoms can oligomerize to form isomeric branched alkane dimers having from about 16 to about 24 carbon atoms, which can provide a desirable combination of thermal management application properties, such as an acceptably high flash point, low pour point, and cooling efficiency (approximated by the Mouromtseff number at 80°C), as discussed further below. Due to the inverse relationship between flash point and Mouromtseff number, it has been difficult to identify heat transfer fluids that exhibit both a high Mouromtseff number and a suitably high flash point, particularly for heat transfer fluids that provide low electrical conductivity. The isomeric branched alkane dimers disclosed herein can be particularly advantageous in their elevated flash points, which can meet or exceed the maximum operating temperature of currently used lithium-ion batteries. The heat transfer fluids of the present specification are characterized by a flash point higher than about 140°C and a pour point lower than about -50°C. Blends of different isomeric branched alkane dimers having a total carbon number within the aforementioned range can also be readily formulated in order to provide further customization of flash point, pour point, and / or cooling efficiency in some cases. Blends of isomeric branched alkane dimers can be formed by combining different size isomeric branched alkane dimers after synthesis, or by co-oligomerizing two different LAOs, as discussed further below. Furthermore, in some cases, it can be advantageous to combine a small amount of a higher branched alkane oligomer, particularly less than 2.5 wt% of an isomeric branched alkane trimer, with an isomeric branched alkane dimer, as discussed further below. Other components can also be included in the heat transfer fluids of the present specification as needed to alter the Mouromtseff number, pour point, cooling efficiency, or other performance characteristics required for compatibility in a given application. As a further advantage, the isomeric branched alkanes formed using a BF3 catalyst system are generally high purity and can be substantially free of ions that cause corrosion (e.g., sulfur-based ions), which is desirable to limit damage to components in contact with the heat transfer fluid during thermal management applications. High thermal and chemical stability can also be achieved within the heat transfer fluids described herein.

[0022] isomer C 20 Heat transfer fluid dimers of branched alkanes (formed by C 10 LAO dimerized in the presence of a BF3 catalyst system, then hydrogenated, are particularly advantageous in their combination of high Mouromtseff number, high flash point, low pour point, and negligible electrical conductivity. Isomer C 20 The combined properties of branched alkane dimers can be particularly suitable for providing thermal management of various components in electric vehicles, particularly electric vehicle batteries. For example, by hydrogenating isomer C10 Isomer C formed from LAO dimers 20 The branched alkane dimers can have a flash point of about 155°C, which is significantly higher than the expected failure temperature of currently common lithium-ion batteries.

[0023] Isomer branched alkane dimers formed from LAO according to the disclosure herein exhibit a Mouromtseff number at 80°C that is consistent with good heat transfer efficiency under operating conditions at that temperature. Mouromtseff numbers measured at other temperatures can represent a more accurate measure of heat transfer efficiency under other operating conditions. The Mouromtseff number of a fluid at a given temperature is represented by Equation 1,

[0024]

[0025] where Mo is the Mouromtseff number, p is the fluid density, k is the thermal conductivity, c p is the specific heat, and m is the dynamic viscosity of the fluid, and a, b, d, and e are empirical values that fit the heat transfer mode of interest. In the case of internal turbulent flow applicable to electric vehicles, the Mouromtseff number can be represented by Equation 2, where the values of a, b, d, and e are empirically determined for turbulent flow conditions.

[0026]

[0027] Given the exponents in Equation 2, the units of the Mouromtseff number under turbulent conditions are W s 0.8 / (m 2.6 · K), which can equivalently be expressed as kg / (s 2.2 · m 0.6 · K) in all SI units. All Mouromtseff numbers expressed herein have these units. A relative Mouromtseff number can be calculated by dividing the Mouromtseff number by the Mouromtseff number of water. Figure 1 A plot of flash point versus Mouromtseff number is shown for various heat transfer fluids. For turbulent conditions, the Mouromtseff number was calculated using Equation 2. As shown, Isomer C 20 formed according to the disclosure herein is located in a desirable region that provides a combination of good heat transfer and flash point performance comparable to values obtained for other types of heat transfer fluids. Isomer branched alkane dimers formed from LAO having about 8 to about 12 carbon atoms can exhibit a Mouromtseff number at 80°C of about 10,000 to about 16,000 kg / (s 2.2 · m 0.6 · K).

[0028] While the isomerically branched paraffin dimers alone can provide advantageous heat transfer properties, it has been found that the presence of a small amount of isomerically branched paraffin trimer in combination with the isomerically branched paraffin dimers can provide a surprising increase in transparency, particularly at low temperatures. For example, such optical transparency can be desirable in order to verify that the heat transfer fluid has not undesirably solidified or gelled. The isomerically branched paraffin trimer can be incorporated in an amount of up to about 2.5 wt% based on the total oligomer, although benefits can be seen at lower amounts (e.g., about 0.5-2 wt%). When incorporated in such small amounts, the isomerically branched paraffin trimer does not significantly impact the Mouromtseff number, flash point, pour point, or other thermal management properties.

[0029] In addition to their advantageous flash point and Mouromtseff number, which are particularly compatible with the operating temperature range of electric vehicles, the isomerically branched paraffin dimers of the present description are substantially electrically insulating. Thus, the isomerically branched paraffin dimers disclosed herein can be particularly suitable heat transfer fluids for impregnating or partially impregnating batteries or other electrical components to facilitate more efficient heat transfer therefrom. While the heat transfer fluids disclosed herein can be advantageous when used in immersion thermal management applications, it should be recognized that the heat transfer fluids can also be used in other manners, such as jacketed and / or circulated heat transfer applications, even if such methods can be less effective for cooling. In addition, the heat transfer fluids disclosed herein can also be suitable for facilitating cooling of an electric motor or one or more electric motor components of an electric vehicle, thereby providing a simplified operation as compared to providing separate cooling systems for the batteries and electric motor of an electric vehicle. Direct cooling using the heat transfer fluids disclosed herein can also be suitable for electric vehicle fast charging stations, which in non-limiting examples can facilitate charging of batteries over a span of about 4-5 minutes. Other heat generating components in electric vehicles, such as frictional heating of vehicle axles, can also be addressed through application of the disclosure herein. In other aspects, the heat transfer fluids disclosed herein can provide advantageous benefits in applications such as server farms, data processing centers, high power electronics, and 5G communication systems. Thus, the present description addresses a number of applications in which dissipation of excess heat can otherwise be problematic.

[0030] All numerical values in the detailed description and claims herein are modified by“about” or“approximately,” with respect to the indicated value, and consider experimental error and variations that would be expected by persons of ordinary skill in the art. Unless otherwise indicated, ambient temperature (room temperature) is about 25 °C.

[0031] As used in the specification and claims, the singular forms“a,”“an,” and“the” include plural references unless the context clearly dictates otherwise.

[0032] The term "and / or" as used in the application in the phrases like "A and / or B" is intended to include both "A and B", "A or B", "A" and "B"

[0033] For the purposes of this specification, the new numbering scheme for the Periodic Table groups is used. In the numbering scheme, the groups (columns) are numbered sequentially from 1 to 18, from left to right, excluding the f-block elements (lanthanides and actinides).

[0034] The term "hydrocarbon" refers to a class of compounds containing hydrogen bonded to carbon and includes (i) saturated hydrocarbon compounds, (ii) unsaturated hydrocarbon compounds, and (iii) mixtures of hydrocarbon compounds (saturated and / or unsaturated), including mixtures of hydrocarbon compounds having different numbers of carbon atoms. The term "C n " refers to a hydrocarbon or hydrocarbyl group having n carbon atoms per molecule or group, where n is a positive integer. Such hydrocarbon compounds can be one or more of linear, branched, cyclic, acyclic, saturated, unsaturated, aliphatic, or aromatic. Optional heteroatom substitution can be present in the hydrocarbon or hydrocarbyl group.

[0035] The terms "hydrocarbyl" and "hydrocarbyl group" are used interchangeably herein. The term "hydrocarbyl group" refers to any C1-C 100 hydrocarbyl group that bears at least one unfilled valence position when removed from the parent compound. Suitable hydrocarbyl groups can be cyclic or acyclic, branched or unbranched, and / or aliphatic or aromatic.

[0036] The term "alkyl" refers to a hydrocarbyl group that contains no unsaturated carbon-carbon bonds. Unless otherwise indicated, optional heteroatom substitution or branching can be present in an alkyl group.

[0037] The term "alkenyl" refers to a hydrocarbyl group having a carbon-carbon double bond. The terms "olefinic" and "olefin" are used synonymously herein. Similarly, the terms "olefinic" and "olefinically" are used synonymously herein. Unless otherwise indicated, these terms encompass all possible geometric isomers.

[0038] The terms "linear" and "linear hydrocarbon" refer to a hydrocarbon or hydrocarbyl group having a continuous carbon chain with essentially no side chain branching.

[0039] The term "linear alpha-olefin (LAO)" refers to an olefinic hydrocarbon bearing a carbon-carbon double bond on a terminal (end) carbon atom of the main carbon chain. Most frequently, no side chain branching is present in a LAO, although a small amount of branched components can occasionally be present in a given LAO sample.

[0040] The terms "branched", "branched", and "branched hydrocarbon" refer to a hydrocarbon or hydrocarbyl group having a linear main carbon chain from which a hydrocarbyl side chain extends. The term "unbranched" refers to a linear hydrocarbon or hydrocarbyl group having no side chain groups extending therefrom.

[0041] LAO can be isolated from refinery streams, which can also be referred to as terminal olefins or terminal olefins. Alternatively, LAO can be synthesized starting from low molecular weight feedstocks by several methods, such as by oligomerization of ethylene or by isolating byproducts from Fischer-Tropsch synthesis. LAO consists of a linear hydrocarbon chain, optionally with a small amount of hydrocarbyl branching (e.g., one methyl or ethyl group per LAO molecule) in a small fraction of the sample that lacks branching, and has the chemical formula C x H 2x (x is an integer greater than or equal to 3, particularly an even integer greater than or equal to 4), wherein there is a double bond between C-1 and C-2. Thus, LAO represents a versatile and inexpensive feedstock for forming LAO dimers and heat transfer fluids that contain isomerically branched paraffins, particularly isomerically branched paraffin dimers, produced according to the specification of this application.

[0042] The heat transfer fluids of the present specification, which can be suitable for cooling batteries or other components of electric vehicles or other applications requiring efficient heat transfer (including electric motors, power electronics, or motor components of electric vehicles), can comprise a plurality of isomerically branched paraffins comprising a hydrogenation reaction product of one or more linear alpha-olefins (LAO) oligomerized with a BF3 catalyst system, the plurality of isomerically branched paraffins comprising at least about 90 wt% isomerically branched paraffin dimers. The one or more LAO has about 8 to about 12 carbon atoms. The plurality of isomerically branched paraffins collectively has a Mouromtseff number in the range of about 10,000 to about 16,000 kg / (s 2.2 ·m 0.6 ·K) at 80 °C, a thermal conductivity of about 0.125 W / m·K or more at 80 °C, and a flash point of about 140 °C or more. The term “collectively” means “in combination” in the present application. Thus, the isomerically branched paraffin dimers, optionally in combination with isomerically branched paraffin trimers and / or additional components, can exhibit the Mouromtseff number, thermal conductivity, and flash point in the aforementioned ranges according to the specification of this application.

[0043] The isomerically branched paraffins can be formed by preparing one or more LAO oligomers under acid-catalyzed oligomerization conditions (e.g., using a BF3 catalyst system), hydrogenating, and separating the isomerically branched paraffin dimers from higher oligomers. Optionally, the LAO dimers can be separated from other LAO oligomers prior to hydrogenation to form the isomerically branched paraffin dimers. Homogeneous LAO oligomers can be prepared by allowing a single type of LAO (e.g., C8, C 10 or C 12LAO) are oligomerized and hydrogenated to form isomeric branched paraffin dimers (e.g., C 16 , C 20 or C 24 branched paraffin dimers), trimers, and higher oligomers. Non-uniform branched paraffin dimers can be formed by dimerizing two LAOs having different chain lengths (e.g., C8and C 10 , C8and C 12 or C 10 and C 12 LAOs to provide C 18 , C 20 or C 22 isomeric branched paraffin dimers, respectively. When two or more different chain length LAOs are dimerized simultaneously, a statistical mixture of both uniform and non-uniform LAO dimers and higher oligomers of all possible carbon atom numbers can be obtained. For example, dimerization of C8and C 10 LAOs can provide isomeric C 16 , C 18 and C 20 as a statistical mixture, as well as trimers and higher oligomers formed from each type of LAO or combinations thereof. The actual product distribution obtained can depend on the relative molar amounts of each type of LAO that is dimerized and their relative reaction rates. Subsequent hydrogenation can result in a similar statistical distribution of corresponding isomeric branched paraffins. The isomeric branched paraffins or a subset of isomeric branched paraffins obtained after hydrogenation can be isolated for use in the heat transfer fluids described in this specification. If the flash point, Mouromtseff number, or other properties of a given sample of isomeric branched paraffin dimers are insufficient for a particular application, a mixture of isomeric branched paraffin dimers and other components, including higher isomeric branched paraffin oligomers obtained from hydrogenation, can be used. As a non-limiting example, isomeric branched paraffin trimers can be present in a heat transfer fluid that primarily comprises isomeric branched paraffin dimers to provide improved transparency, as discussed further below.

[0044] C8-C 12 LAOs, hydrogenation, and isolation of a fraction comprising isomeric branched paraffin dimers. It will be appreciated that similar isomeric branched paraffin dimers within the foregoing C 16 -C 24 range can be synthesized by oligomerizing C8-C 16 -C 24 LAOs having a carbon number higher than and lower than C8-C 12A wide range of LAOs can be prepared by dimerization, but the formation of isomeric branched paraffin dimers in this way can be accompanied by the undesirable formation of heavy and light species.

[0045] The isomer branched paraffin dimer formed according to this specification is distinguishable from the corresponding branched paraffin dimer formed by other oligomerization techniques, such as metallocene-catalyzed oligomerization and subsequent hydrogenation. Metallocene-catalyzed LAO oligomerization produces one or a very limited number of branched paraffin dimers because no alkyl group migration occurs during the metallocene-catalyzed oligomerization. In addition, the commercial source of LAO can contain a small amount of branched olefins and internal olefins. When using BF3 catalyst system or similar acid catalysts, all of these materials may undergo oligomerization. On the contrary, under the conditions of metallocene-catalyzed oligomerization, if internal olefins and branched olefins react fundamentally, they may more conflict with oligomerization. Therefore, it is believed that the heat transfer fluid of this specification contains at least some isomer branched paraffin dimers that are not obtained by metallocene-catalyzed oligomerization and subsequent hydrogenation.

[0046] In more specific embodiments, the heat transfer fluids of the present disclosure may comprise at least about 90 wt% isomeric branched paraffins. As discussed herein, C 20 Isomeric branched paraffin dimers are particularly suitable for use in the heat transfer fluids of the present invention. 10 LAO obtained C 20 Isomer branched paraffin dimers may be present in certain heat transfer fluids. More specific heat transfer fluids of this specification may contain at least about 90 wt% of C 10 LAO forms isomeric branched paraffin dimers (i.e., multiple isomeric C 20 In other specific embodiments, the heat transfer fluid may comprise at least about 95 wt% of isomer C 20 Branched paraffin dimer, or at least about 98 wt% of isomer C 20 Branched paraffin dimers, and other isomers that make up the remainder of the heat transfer fluid C 16 -C 24 Branched paraffin dimers and / or other components. Multiple isomers of branched paraffins in certain heat transfer fluids primarily (e.g., >92 wt%) contain isomer C 20 Branched paraffin dimers with non-zero amounts of isomer C 16 , C 18 , C 22 and / or C 24 The isomeric branched paraffin dimers are in combination, each up to about 2 wt %. In a more specific example, the isomeric branched paraffins can be substantially composed of isomeric C 20 Branched chain alkane dimer composition.

[0047] Branching paraffins formed from LAO oligomers higher than dimers, such as trimers, tetramers, pentamers, and higher oligomers, can provide insufficient values for one or more of the Mouromtseff number, thermal conductivity, pour point, and flash point suitable for forming a suitable heat transfer fluid. Unexpectedly, the inclusion of small amounts of isomerically branched paraffin trimers formed from LAO, such as isomerically branched paraffin trimers formed from 1-decene with the promotion of a BF3 catalyst system, can have a surprising effect on the clarity of a heat transfer fluid that primarily comprises isomerically branched paraffin dimers, without unduly affecting the Mouromtseff number, thermal conductivity, pour point, or flash point. The heat transfer fluids of the present specification can comprise about 2.5 wt% or less of isomerically branched paraffin trimers, or about 2 wt% or less of isomerically branched paraffin trimers, such as about 0.5 wt% to about 2 wt% of isomerically branched paraffin trimers, as measured relative to the total oligomers present in the heat transfer fluid. In particular examples, the isomerically branched paraffin trimers are formed from C 10 Isomer C of LAO preparation 20 The branched paraffin trimers can be present in an amount of about 0.5 wt% to about 2 wt%, or about 0.7 wt% to about 2 wt%, or about 1 wt% to about 2 wt%.

[0048] In the presence of an acid catalyst system, such as AlCl3, BF3, or a BF3 complex and a suitable set of promoters, LAO can form LAO oligomers having branching at a range of positions on the oligomer carbon chain and having different oligomer sizes, as described in further detail below. The BF3 catalyst system can represent a particularly suitable acid catalyst system for preparing the branched LAO oligomers in the present specification. Dimers, trimers, tetramers, and higher LAO oligomers can form in the presence of BF3 and suitable promoters, with trimers and tetramers being produced in higher amounts than dimers, as described in U.S. Patent Application Publication No. 2006 / 0211904, which is incorporated by reference into the present application. Other suitable conditions for forming LAO oligomers in the presence of a BF3 catalyst system are disclosed in U.S. Patent Nos. 3,382,291, 5,068,487, and 6,075,174, which are also incorporated by reference in their entireties into the present application. Following hydrogenation, the corresponding isomerically branched paraffins can be produced, which can then be isolated as the minor product isomerically branched paraffin dimers for use within a heat transfer fluid according to the present disclosure.

[0049] The BF3 catalyst system suitable for oligomerization of LAO can comprise BF3 and at least two different promoters, in particular at least one alcohol promoter and at least one ester promoter. Without being limited by theory or mechanism, it is believed that at least one ester promoter promotes chain termination during oligomerization. The BF3 gas is preferably introduced into the reactor simultaneously with the at least two different promoters and the olefin feed. The at least two different promoters and / or the reaction mixture can be saturated with BF3: such that the BF3 is maintained at a pressure of about 2 psig to about 50 psig, preferably about 2 psig to about 10 psig in the headspace of the reactor. The alcohol promoter can be selected from the group consisting of C1 to C6 alcohols. The alcohol can be a straight or branched chain alcohol, for example methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, or any combination thereof. The ester promoter used in combination with the alcohol promoter can be selected from the reaction product of an alcohol and an acid. Suitable alcohols for forming the ester promoter can include those suitable for the alcohol promoter (i.e., C1 to C6 alcohols), as described above. The alcohol portion of the alcohol promoter and the ester promoter can comprise the same alcohol or different alcohols. The acid portion of the ester promoter can be a monocarboxylic acid such as formic acid, acetic acid, propionic acid, and the like, with acetic acid being particularly desirable. The ratio of alcohol promoter to ester promoter can range from about 0.2:1 to about 15:1 on a molar basis, or about 0.5:1 to about 7:1 on a molar basis. More preferably, the ratio of alcohol promoter to ester promoter can be about 1 : 1 to about 1 :3 on a molar basis, most preferably about 1.7: 1 to about 2.3: 1 on a molar basis. The BF3 is a gas and is typically fed in excess, for example at a pressure of about 5 psig. 10 The alcohol or C1 to C6 alcohol. The alcohol can be a straight or branched chain alcohol, for example methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, or any combination thereof. The ester promoter used in combination with the alcohol promoter can be selected from the reaction product of an alcohol and an acid. Suitable alcohols for forming the ester promoter can include those suitable for the alcohol promoter (i.e., C1 to C 10 The alcohol or C1 to C6 alcohol. The alcohol can be a straight or branched chain alcohol, for example methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, or any combination thereof. The ester promoter used in combination with the alcohol promoter can be selected from the reaction product of an alcohol and an acid. Suitable alcohols for forming the ester promoter can include those suitable for the alcohol promoter (i.e., C1 to C

[0050] Suitable temperatures for forming LAO oligomers using the BF3 catalyst system can be about 0 °C to about 50 °C, or about 15 °C to about 35 °C, or about 20 °C to about 30 °C, or about 20 °C to about 24 °C.

[0051] Schemes 1-3 below provide reaction schemes and illustrative structures for branched LAO dimers and branched paraffin dimers made therefrom in accordance with the description of the present application. Since the oligomerization reactions disclosed herein can occur with double bond migration, it will be recognized that the branching location and size of the branches can differ from those explicitly disclosed in the schemes (e.g., at a deeper position within the hydrocarbyl chain). By way of non-limiting example and without being bound by any particular theory, the dimer in Scheme 1 can arise by formation of a carbocation at the allylic position followed by addition of the terminal olefinic carbon of a second LAO molecule to the allylic carbocation. In Scheme 2, dimerization can occur similarly by way of formation of a secondary carbocation, again resulting in a single branched dimer at a different position in the carbon chain. In Scheme 3, the benzyl carbonium ion can react at C-2 of a second LAO molecule to provide a di-branched paraffin dimer.

[0052]

[0053]

[0054] Hydrogenation of the LAO dimers to provide isomeric branched paraffin dimers can be carried out using various Ni, Pt, or Pd hydrogenation catalysts in a slurry or fixed bed reactor system. The Ni catalysts can optionally be sulfided. Suitable hydrogenation conditions, hydrogenation catalysts, reactors, etc. are familiar to one of ordinary skill in the art. In non-limiting embodiments, the hydrogenation can be carried out at a pressure of about 100 psi to about 300 psi and a temperature of about 200 °C to about 300 °C.

[0055] The heat transfer fluids described herein can be particularly suitable for incorporation into electric vehicles. Accordingly, the electric vehicles disclosed herein can include a heat generating component and a heat transfer fluid in contact with the heat generating component. Any of the heat transfer fluids defined above can be present in the electric vehicles defined herein. The heat transfer fluids defined above can also be present in battery systems and thermal management systems and can be incorporated into thermal management methods, as further defined herein.

[0056] Other components can be included in the heat transfer fluids disclosed herein. Additional components that can be present in the heat transfer fluids to address specific application-specific needs include, for example, base oils, aromatic hydrocarbons, polyalphaolefins, paraffins, esters, ethers, gas-to-liquid base oils, Fischer-Tropsch wax derived base oils, wax derived hydroisomerization base oils, silicone oils, antioxidants, corrosion inhibitors, antifoams, anti-wear agents, dispersants, detergents, viscosity improvers, and any combination thereof. Suitable examples of additional components that can be present are discussed below.

[0057] A variety of heat transfer fluid base oils are known in the art. Heat transfer fluid base oils useful in the present specification include natural oils, mineral oils, and synthetic oils, as well as unconventional oils (or mixtures thereof), any of which can be used unrefined, refined, or rerefined, the latter also known as reclaimed or reprocessed oils. Unrefined oils include those obtained directly from a natural or synthetic source without further purification, except removal of water and / or heat. These include shale oils obtained directly from retorting operations, petroleum oils obtained directly from primary distillation, and ester oils obtained directly from esterification processes. Refined oils are similar to the oils discussed above for unrefined oils, except that refined oils have been subjected to one or more purification steps to improve at least one heat transfer fluid base oil property. Those of skill in the art will be familiar with a number of purification methods. Such purification methods can include solvent extraction, secondary distillation, acid extraction, base extraction, filtration, percolation, and any combination thereof. Rerefined oils are obtained by processes similar to refined oils, but using oil that has previously been used as feedstock.

[0058] Classes I, II, III, IV, and V are broad base stock categories developed and defined by the American Petroleum Institute (API Publication 1509; www.api.org) to create a guide for heat transfer fluid base stocks. Class I base stocks have a viscosity index of about 80-120 and contain greater than about 0.03% sulfur and / or less than about 90% saturates. Class II base stocks have a viscosity index between about 80 and 120, and contain less than or equal to about 0.03% sulfur and greater than or equal to about 90% saturates. Class III base stocks 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. Class IV base stocks include polyalphaolefins (PAO). Class V base stocks include base stocks not included in Classes I-IV. Table 1 below summarizes the properties of each of the five classes.

[0059] Table 1

[0060]

[0061] Natural oils include animal oils, vegetable oils (e.g., castor oil and lard oil), and mineral oils. Animal and vegetable oils possessing favorable thermal oxidative stability can be used. Of the natural oils, mineral oils are preferred. Mineral oils vary widely in their

[0062] Class II and / or III hydrotreated or hydrocracked base stocks, including synthetic oils such as alkyl aromatics and synthetic esters are also well known base stock oils useful in the present specification.

[0063] Synthetic oils include hydrocarbon oils. Hydrocarbon oils include oils such as polymeric and interpolymerized olefins (e.g., polybutenes, polypropenes, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylene-alpha-olefin copolymers). Polyalphaolefin (PAO) oil base stocks are commonly used synthetic hydrocarbon oils. For example, PAOs derived from C8, C 10 , C 12 or C 14 olefins or mixtures thereof can be used, such as U.S. Pat. Nos. 4,956,122; 4,827,064; and 4,827,073, each of which is incorporated herein by reference.

[0064] Other useful heat transfer fluid oil base stocks include wax isomerate base stocks and base oils, including hydroisomerized wax stocks (e.g., wax stocks such as gas oil, slack wax, fuel hydrocracker bottoms, etc.), hydroisomerized Fischer-Tropsch waxes, gas-to-liquid (GTL) base stocks and base oils, and other wax isomerate hydroisomerized base stocks and base oils, or mixtures thereof. Fischer-Tropsch waxes, high boiling point residues of Fischer-Tropsch synthesis, are highly paraffinic with very low sulfur content. The hydroprocessing used to produce such base stocks can use an amorphous hydrocracking / hydroisomerization catalyst, such as one of a specialty lube hydrocracking (LHDC) catalyst or a crystalline hydrocracking / hydroisomerization catalyst, preferably a zeolite catalyst.

[0065] Gas-to-liquid (GTL) base oils, Fischer-Tropsch wax derived base oils, and other wax derived hydroisomerized (wax isomerate) base oils can be advantageously used in the present specification, and can have a useful kinematic viscosity at 100°C of about 3 cSt to about 50 cSt, preferably about 3 cSt to about 30 cSt, more preferably about 3.5 cSt to about 25 cSt, as exemplified by GTL 4 which has a kinematic viscosity at 100°C of about 4.0 cSt and a viscosity index of about 141. These gas-to-liquid (GTL) base oils, Fischer-Tropsch wax derived base oils, and other wax derived hydroisomerized base oils can have a useful pour point of about -20°C or lower, and in some cases can have a useful pour point of about -25°C or lower, with useful pour points of about -30°C to about -40°C or lower. Useful compositions of gas-to-liquid (GTL) base oils, Fischer-Tropsch wax derived base oils, and wax derived hydroisomerized base oils are set forth in U.S. Patent Nos. 6,080,301; 6,090,989; and 6,165,949, and the entire contents of which are incorporated herein by reference.

[0066] Esters can constitute useful base stocks. Additive solvency and seal compatibility characteristics can be ensured by the use of esters such as esters of dibasic acids with monoalkanols and polyhydric alcohol esters of monocarboxylic acids. The former type of ester includes, for example, esters of dicarboxylic acids such as phthalic acid, succinic acid, alkyl succinic acids, alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonic acids, and the like, with various alcohols such as butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, 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, dieicosyl sebacate, and the like.

[0067] Base oils suitable for use in the heat transfer fluids useful in the present description can include any of the various oils corresponding to API Group I, Group II, Group III, Group IV, and Group V oils and mixtures thereof, preferably API Group II, Group III, Group IV, and Group V oils and mixtures thereof, more preferably Group III, Group IV, and Group V base oils and mixtures thereof. The use of premium paraffinic base oils is advantageous for the heat transfer fluids used in the present description. Small amounts of Group I base stocks can also be used, for example, in amounts used to dilute additives for blending into formulated lubricating oil products. Even for Group II stocks, it is preferred that the Group II stock be in the higher quality range for that stock, such as Group II base stocks having a viscosity index in the range of 100 < VI < 120.

[0068] The base oil can constitute a minor or major component of the heat transfer fluids of the present description and can be present in an amount of about 50 to about 99 wt%, preferably about 70 to about 95 wt%, more preferably about 85 to about 95 wt%, based on the total weight of the composition, or the base oil can be present in an amount of about 10 wt% or less. The base oil conveniently has a kinematic viscosity at 100°C of about 2.5 cSt to about 12 cSt (or mm 2 / s) according to ASTM standards, preferably a kinematic viscosity at 100°C of about 2.5 cSt to about 9 cSt (or mm 2 / s). If desired, mixtures of synthetic and natural base oils can be used. If desired, bimodal mixtures of Group I, II, III, IV, and / or V base stocks can be used.

[0069] The heat transfer fluids useful in the present description can additionally contain one or more of the commonly used heat transfer fluid performance additives including, but not limited to, antioxidants, corrosion inhibitors, antifoams, and the like. These additives are typically shipped with varying amounts of diluent oil, which can range from 5 wt% to 50 wt% of the heat transfer fluid, or about 10 wt% or less of the heat transfer fluid. The additives useful in the present description need not be soluble in the heat transfer fluid. The type and amount of performance additives used in the heat transfer fluids of the present description are not limited by the examples shown as illustrations in the present application.

[0070] The heat transfer fluid can include at least one antioxidant. Antioxidants retard the oxidative degradation of the fluid during use. Such degradation can result in the presence of deposits, sludges on metal surfaces, or an increase in the viscosity of the heat transfer fluid. Those of ordinary skill in the art will appreciate that a wide variety of oxidation inhibitors can be used in heat transfer fluids. See, for example, Klamann in Lubricants and Related Products, Verlag Chemie, Deerfield Beach, FL; ISBN 0-89573-177-0 and U.S. Patents 4,798,684 and 5,084,197. A particular example of a heat transfer fluid can include at least two different antioxidants, preferably at least one phenolic-based antioxidant and at least one amine-based antioxidant. The presence of both types of antioxidants in combination can provide lower viscosity values and better oxidation performance than either type of antioxidant alone, thereby providing more stable heat transfer performance over a longer period of time. The amount of at least one phenolic-based antioxidant can be about 0.25 wt% or more, or about 0.5 wt% or more, preferably in the range of about 0.25 wt% to about 5 wt%, or about 0.5 wt% to about 4 wt%, or about 0.75 wt% to about 3 wt%, or about 1 wt% to about 2.5 wt%, or about 0.75 wt% to about 2.25 wt%. The amount of at least one amine-based antioxidant can be about 0.1 wt% or more or about 0.2 wt% or more, preferably in the range of about 0.1 wt% to about 1 wt%, or about 0.2 wt% to about 0.9 wt%, or about 0.25 wt% to about 0.75 wt%. In a non-limiting example, at least one phenolic-based oxidant can be present in an excess weight percentage relative to at least one amine-based oxidant, preferably at least about a 2: 1 excess of at least one phenolic-based oxidant. A particular example of a suitable heat transfer fluid can include at least about 0.25 wt% of at least one phenolic-based antioxidant and at least about 0.1 wt% of at least one amine-based antioxidant, or at least about 0.5 wt% of at least one phenolic-based antioxidant and at least about 0.2 wt% of at least one amine-based antioxidant.

[0071] The heat transfer fluid can include at least one corrosion inhibitor. Corrosion inhibitors are used to reduce the degradation of metal components in contact with the heat transfer fluid. Corrosion inhibitors are additives that protect metal surfaces from chemical attack by water or other contaminants. A wide variety of corrosion inhibitors are commercially available. As used herein, corrosion inhibitors include rust-preventive additives and metal deactivators. Suitable corrosion inhibitors also include arylthiazines, alkyl-substituted dimercaptothiadiazoles, alkyl-substituted dimercaptothiadiazoles, and mixtures thereof.

[0072] One type of suitable corrosion inhibitor is a polar compound that preferentially wets the metal surface, protecting it with a film of oil. Another type of corrosion inhibitor absorbs water by incorporating it into a water-in-oil emulsion, so that only oil contacts the metal surface. Still another type of corrosion inhibitor chemically adheres to the metal to produce a non-reactive surface. Examples of suitable additives include zinc dithiophosphates, metal phenates, basic metal sulfonates, fatty acids, and amines. Such additives can be used in amounts of about 0.01 wt% to 5 wt%, preferably about 0.01 to 1.5 wt%, more preferably 0.01 to 0.2 wt%, still more preferably 0.01 to 0.1 wt% (as received at the time of receipt) based on the total weight of the heat transfer fluid.

[0073] Antifoam agents can be advantageously added to the heat transfer fluid. These agents retard the formation of stable foams. Silicones and organic polymers are typical antifoam agents. For example, polysiloxanes, such as silicone oil or polydimethylsiloxane, provide antifoam properties. Antifoam agents are commercially available and can be used in conventional small amounts along with other additives such as demulsifiers; typically the combined amount of these additives is less than 1 wt%, often less than 0.1 wt%. In one embodiment, such additives can be used in amounts of about 0.01 to 5 wt%, preferably 0.1 to 3 wt%, more preferably about 0.5 to 1.5 wt%.

[0074] The heat transfer fluid can include at least one anti-wear agent. Examples of suitable anti-wear agents include oil-soluble amine salts of phosphorus compounds, sulfurized olefins, metal dihydrocarbyl dithiophosphates (such as zinc dialkyldithiophosphate), thioaminoformic acid containing compounds such as thioaminoformic acid esters, thioaminoformic acid amides, thioaminoformic acid ethers, alkylene-coupled thioaminoformic acid esters, and bis(S-alkyldithioaminoformyl) disulfides.

[0075] The anti-wear agents used in the heat transfer fluid can be ashless or ash-forming in nature. Preferably, the anti-wear agents are ashless. Ashless anti-wear agents are materials that do not substantially form ash upon combustion. For example, anti-wear agents that do not contain metals are considered to be ashless.

[0076] The heat transfer fluids of the present description can additionally contain one or more other commonly used heat transfer fluid performance additives including, but not limited to, dispersants, detergents, viscosity improvers, metal deactivators, ionic liquids, extreme pressure additives, anti-seizure agents, wax modifiers, fluid loss additives, seal compatibility agents, lubricity agents, stain prevention agents, chromophores, antifoams, demulsifiers, emulsifiers, thickening agents, wetting agents, gelling agents, tackifiers, colorants, and the like. For a review of many commonly used additives, see Klamann in Lubricants and Related Products, Verlag Chemie, Deerfield Beach, FL; ISBN 0-89573-177-0; see also U.S. Patent No. 7,704,930, the disclosure of which is incorporated by reference in its entirety into the present application. These additives are often shipped with varying amounts of diluent oil, which is in the range of 5 wt% to 50 wt%.

[0077] The heat transfer fluid can include at least one dispersant. During operation of electrical equipment components, oil insoluble oxidation by-products are generated. Dispersants help to keep these by-products in solution, thereby reducing their deposition on metal surfaces. The dispersants used in the formulation of the heat transfer fluid can be ashless or ash-forming in nature. Preferably, the dispersants are ashless. So-called ashless dispersants are organic materials that do not form substantial amounts of ash upon burning. For example, dispersants that do not contain metals or borated metals are considered to be ashless.

[0078] Suitable dispersants typically contain a polar group attached to a relatively high molecular weight hydrocarbon chain. The polar group typically contains at least one element of nitrogen, oxygen, or phosphorus. Typical hydrocarbon chains contain 50 to 400 carbon atoms.

[0079] The heat transfer fluid can include at least one detergent. Illustrative detergents useful in the present description include, for example, alkali metal detergents, alkaline earth metal detergents, and alkaline earth metal detergents, or a mixture of one or more alkali metal detergents and one or more alkaline earth metal detergents. Typical detergents are anionic materials that contain a long-chain hydrophobic portion of the molecule and a smaller anionic or oleophobic hydrophilic portion of the molecule. The anionic portion of the detergent is typically derived from an organic acid such as sulfuric acid, carboxylic acid (e.g., salicylic acid), phosphorous acid, phenol, or mixtures thereof. The counterion is typically an alkaline earth metal or an alkali metal.

[0080] Viscosity improvers (also known as viscosity index improvers (VI improvers) and viscosity modifiers) can be included in the heat transfer fluids of the present description. Viscosity improvers provide high and low temperature operability to the heat transfer fluids. These additives impart shear stability at high temperatures and acceptable viscosity at low temperatures. Suitable viscosity improvers include high molecular weight hydrocarbons, polyesters, and viscosity improver dispersants that serve as both viscosity improvers and dispersants. These polymers typically have a molecular weight of about 10,000 to 1,500,000, more typically about 20,000 to 1,200,000, and even more typically about 50,000 to 1,000,000.

[0081] Examples of suitable viscosity improvers include linear or star polymers and copolymers of methyl acrylate, butadiene, olefins, or alkylated styrene. Polyisobutylenes are commonly used viscosity improvers. Another suitable viscosity improver is polymethacrylate (e.g., copolymers of various chain length alkyl methacrylates), some formulations of which are also used as pour point depressants. Other suitable viscosity improvers include copolymers of ethylene and propylene, hydrogenated block copolymers of styrene and isoprene, and polyacrylates (e.g., copolymers of various chain length acrylates). Specific examples include styrene-isoprene or styrene-butadiene based polymers having a molecular weight of 50,000 to 200,000.

[0082] The heat transfer fluids can include at least one metal deactivator. Metal deactivators / passivators include, for example, benzotriazole, tolyltriazole, 2-mercaptobenzothiazole, dialkyl-2,5-dimercapto-l,3,4-thiadiazole; N,N'-disalicylideneethylenediamine, N,N'-disalicylidene- propylenediamine; zinc dialkyldithiophosphates, and zinc dialkyldithiocarbamates. The concentration of metal deactivator in the heat transfer fluids of the present description can range from about 0.01 wt% to about 5.0 wt%, preferably from about 0.01 wt% to 3.0 wt%, and more preferably from about 0.01 wt% to about 1.5 wt%, based on the total weight of the heat transfer fluid.

[0083] Ionic liquids are so-called salt melts, which are preferably liquid at room temperature and / or have a melting point below 100°C by definition. They have almost no vapor pressure and therefore no cavitation characteristics. Furthermore, by choosing the cation and anion in the ionic liquid, the lifetime of the heat transfer fluid can be increased and by adjusting the electrical conductivity, these liquids can be used in devices where charge accumulation exists, such as electrically powered vehicle components. Suitable cations for ionic liquids include quaternary ammonium cations, phosphonium cations, imidazolium cations, pyridinium cations, pyrazolium cations, oxazolium cations, pyrrolidinium cations, piperidinium cations, thiazolium cations, guanidinium cations, morpholinium cations, trialkylsulfonium cations, or triazolium cations.

[0084] Static electricity is generated in electrical equipment components, particularly when heat transfer fluids are used. To reduce this hazard, electrically conductive antistatic additives can be added to and distributed throughout the heat transfer fluid. The heat transfer fluid will thus avoid performance reduction associated with localized breakdown of the base stock and safety problems from static buildup.

[0085] A class of products known as "antistatic fluids" or "antistatic additives," which are also petroleum distillates, can be added to adjust the conductivity of the heat transfer fluid to a safe level, for example, equal to or greater than 100 picosiemens / meter conductivity. Very small amounts of these antistatic fluids are needed to increase the conductivity to the desired level, for example, 10 to 30 milliliters per 1,000 gallons of hydrocarbon.

[0086] Conventional pour point depressants, also known as lube oil flow improvers, can be added to the heat transfer fluids of the present description. Pour point depressants can be added to the heat transfer fluids of the present description to lower the minimum temperature at which the fluid will flow or can be poured. Examples of suitable pour point depressants include polymethacrylates, polyacrylates, polyaryl amides, condensation products of halogenated paraffins and aromatic compounds, carboxylic acid vinyl ester polymers, and terpolymers of fumaric acid dialkyl ester, fatty acid vinyl ester, and allyl vinyl ether. U.S. Pat. Nos. 1,815,022; 2,015,748; 2,191,498; 2,387,501; 2,655,479; 2,666,746; 2,721,877; 2,721,878; and 3,250,715, each incorporated herein by reference, disclose useful pour point depressants and / or their preparation. Such additives can be used in amounts of about 0.01 to 5 wt.%, preferably 0.1 to 3 wt.%, more preferably about 0.5 to 1.5 wt.%.

[0087] The heat transfer fluid can include at least one seal compatibility agent. Seal compatibility agents help to swell elastomeric seals by causing a chemical reaction in the fluid or a physical change in the elastomer. Suitable seal compatibility agents for use in heat transfer fluids include organophosphates, aromatic esters, aromatic hydrocarbons, esters (e.g., butyl benzyl phthalate), and polybutenyl succinic anhydride. Such additives can be used in amounts of about 0.01-5 wt.%, preferably 0.1-3 wt.%, more preferably about 0.5-1.5 wt.%.

[0088] The heat transfer fluid can include at least one friction modifier. A friction modifier is any material or materials that can change the coefficient of friction of a surface. If desired, friction modifiers (also known as friction reducers or lubricity agents or oiliness agents) and other such agents that change the ability of a base oil, formulated heat transfer fluid, or functional fluid to change the coefficient of friction of a surface can be effectively used in combination with the base oils or heat transfer fluids of the present description. Friction modifiers that reduce the coefficient of friction are particularly advantageous in combination with the base oils and heat transfer fluids of the present description.

[0089] Exemplary friction modifiers can include, for example, organometallic compounds or materials, or mixtures thereof. Exemplary organometallic friction modifiers useful in the heat transfer fluids of the present description include, for example, molybdenum amines, molybdenum diamines, organotungstate salts, molybdenum dithiocarbamates, molybdenum dithiophosphates, molybdenum amine complexes, molybdenum carboxylates, and the like, and mixtures thereof. Similar tungsten-based compounds are preferred.

[0090] Other exemplary friction modifiers useful in the heat transfer fluids of the present description include, for example, alkoxylated fatty acid esters, alkanolamides, polyol fatty acid esters, borated glycerol fatty acid esters, fatty alcohol ethers, and mixtures thereof.

[0091] The heat transfer fluid can include at least one extreme pressure agent (EP). EP agents soluble in oil include sulfur-containing and chlorine-sulfur-containing EP agents, chlorinated hydrocarbon EP agents, and phosphorus EP agents. Examples of such EP agents include chlorinated waxes; sulfurized olefins (such as sulfurized isobutylene), organosulfides and polysulfides such as dibenzyl disulfide, bis-(chlorobenzyl) disulfide, dibutyl tetrasulfide, sulfurized methyl oleate, sulfurized alkyl phenol, sulfurized dipentene, sulfurized terpenes, and sulfurized Diels-Alder adducts; phosphorus sulfurized hydrocarbons such as the reaction product of sulfurized phosphorus with turpentine or methyl oleate; phosphorus esters such as dihydrocarbyl phosphites and trihydrocarbyl phosphites, including dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentyl phenyl phosphite; dipentyl phenyl phosphite, tridecyl phosphite, distearyl phosphite, and polypropylene-substituted phenol phosphite; metal thiocarbamates such as zinc dioctyldithiocarbamate and barium heptylphenol diacidate; amine salts or derivatives of alkyl and dialkyl phosphoric acids; and mixtures thereof (as described in U.S. Patent 3,197,405, which is incorporated herein by reference).

[0092] The extreme pressure agent can be used in an amount of about 0.01 to 5 wt%, preferably 0.01 to 1.5 wt%, more preferably 0.01 to 0.2 wt%, still more preferably 0.01 to 0.1 wt% (as received at the time of receipt) based on the total weight of the heat transfer fluid.

[0093] When the heat transfer fluid contains one or more of the above additives, the additives are blended into the heat transfer fluid in an amount sufficient for the heat transfer fluid and the additives to perform their intended functions. Typical amounts of such additives useful herein are shown in Table 2 below.

[0094] It should be noted that many additives are shipped from additive manufacturers as concentrates containing one or more additives and a certain amount of base oil diluent. Therefore, the weights in Table 2 below and other amounts mentioned herein refer to the amount of active ingredient (i.e., the non-diluent portion of the ingredient). The wt% values ​​shown below are based on the total weight of the heat transfer fluid.

[0095] Table 2

[0096] Compound Approximate Wt% (useful) Approximate Wt% (preferred) Antioxidant 0.01-5 0.1-1.5 Corrosion Inhibitor 0.01-5 0.1-2 Defoamer 0-3 0.001-0.15 Metal deactivator 0.01-5 0.01-1.5 Pour Point Depressant 0.01-5 0.5-1.5 Seal Compatibility Agent 0.01-5 0.5-1.5 Extreme Pressure Agent 0.01-5 0.01-0.1

[0097] The above-mentioned additives are all commercially available materials. These additives can be added individually or pre-combined in packages that can be obtained from suppliers of heat transfer fluid additives. Additive packages with various compositions, proportions, and properties are available, and the selection of an appropriate package will take into account the desired use of the final heat transfer fluid.

[0098] The electric vehicle of the present specification may include any heat transfer fluid further described herein. As described above, in a particular embodiment the heat transfer fluid may contain at least about 90 wt% of an isomer branched paraffin dimer. In another particular embodiment, at least isomer C 20 Branched paraffin dimers may be present in the heat transfer fluid. In yet another specific embodiment, the heat transfer fluid may comprise at least about 90 wt% of isomer C 20 Branched paraffin dimer or at least about 95 wt% of isomer C 20 Branched paraffin dimer. The heat transfer fluid may further comprise about 2.5 wt% or less of an isomeric branched paraffin trimer, e.g., about 2 wt% or less, or about 1 wt% or less, based on the total oligomers present. Optionally, as described above, other branched paraffin dimers or other suitable components may also be present in the heat transfer fluid.

[0099] The heat transfer fluid can be in contact with an outer surface of the heat generating component, including jacketed and immersion configurations. Jacketed configurations include any configuration in which the heat transfer fluid does not directly contact the cell components or other heat generating components of the battery. In contrast, immersion configurations include any configuration in which one or more cell components or other heat generating components of the battery are directly in contact with the heat transfer fluid. That is, an immersion configuration does not necessarily mean that the battery or other heat generating component is completely submerged in the heat transfer fluid, although it can be. Certain immersion configurations can include those in which the battery cells are enclosed in a suitable container and the heat transfer fluid is circulated between the walls of the container and the battery cells. In more particular embodiments, the heat generating component can be at least partially submerged in the heat transfer fluid. In some embodiments, the heat generating component can be completely submerged in the heat transfer fluid. When in contact with the outer surface of the heat generating component, the heat transfer fluid can be in an open or closed system. For example, a closed system can be configured to circulate the heat transfer fluid between the heat generating component and a heat sink, heat spreader, or similar structure capable of removing excess heat from the heat transfer fluid.

[0100] In other embodiments, the heat generating component can include internal passageways configured for circulation of the heat transfer fluid. Thus, the heat transfer fluid can also contact additional surfaces of the heat generating component in addition to the outer surface. The engineering design of a particular heat generating component, such as an electric motor or battery of an electric vehicle, can determine whether internal passageways can be appropriately present. Emerging motor designs, for example, motors mounted directly to each shaft, can require different cooling methods than those conventionally incorporated within the body of the vehicle. When internal passageways can be appropriately present, in some embodiments, the heat transfer fluid can be circulated within the internal passageways in addition to contacting the outer surface of the heat generating component. When the heat transfer fluid contacts the outer surface of the heat generating component and is also circulated within internal passageways of the heat generating component, two different sources of heat transfer fluid can be used. For example, in particular embodiments, the heat transfer fluid contacting the outer surface and the heat transfer fluid circulated within the internal passageways can be isolated from one another (e.g., by being present in separate reservoirs) such that the heat transfer fluids do not mix. Further, the heat transfer fluid contacting the outer surface and the heat transfer fluid circulated within the internal passageways can be the same or different according to various embodiments of the present description.

[0101] In some or other embodiments, the electric vehicle of the present description can also include a heat sink structure in fluid communication with the heat transfer fluid. In illustrative embodiments, the heat sink structure can include conventional heat sinks, for example, heat spreaders, heat fins, or similar air cooling structures. Unconventional and emerging heat sink structures can also be used in various instances. In more particular embodiments, the heat transfer fluid can be configured to circulate between the heat generating component and the heat sink structure. Any type of pump can assist in circulating the heat transfer fluid from the heat generating component to the heat sink structure.

[0102] In still more particular embodiments, the heat generating components within the electric vehicle described herein can be a battery, an electric motor, multiple electric motors, a power component, an engine component, a shaft, an electronic device, or any combination thereof. The power component can include, for example, a DC / AC inverter, a DC / DC converter, or an AC / DC converter. High power fast charging stations for electric vehicles can also use the heat transfer fluids disclosed herein for cooling. In some embodiments, the heat transfer fluids described herein can contact at least the outer surface of a battery used to power the electric vehicle, including immersing or partially immersing the battery in the heat transfer fluid. The engine or engine components of the electric vehicle can be thermally regulated by the heat transfer fluids of the present description or by conventional heat transfer fluids, such as glycol water solutions. However, in more particular embodiments, both the battery and the engine or engine components of the electric vehicle can be in fluid communication with one or more of the heat transfer fluids described herein. The heat transfer fluids in fluid communication with the battery and the engine or engine components can originate from a common source, or the heat transfer fluids in fluid communication with the battery and the heat transfer fluids in fluid communication with the engine or engine components can originate from different sources. Accordingly, the cooling systems suitable for thermally regulating the battery and electric motor of the electric vehicle can be the same or different in the disclosure herein.

[0103] In view of the foregoing, the present description also describes a battery system comprising the heat transfer fluids of the present invention. The battery systems described herein can include a battery, such as a lithium ion battery, and a heat transfer fluid in contact with the battery. Any of the heat transfer fluids specified herein can be present in the battery system.

[0104] According to particular embodiments of the present invention, the heat transfer fluid can be in contact with the outer surface of the battery, including jacketed and immersion configurations. In more particular embodiments, the battery can be at least partially submerged in the heat transfer fluid. In some embodiments, the battery can be fully submerged in the heat transfer fluid, including submerging the leads of the battery within the heat transfer fluid. The heat transfer fluid in contact with the outer surface of the battery can be in an open or closed system. In some or other embodiments, the battery can include a plurality of internal channels configured for circulating the heat transfer fluid, such as between the battery and a heat sink structure.

[0105] In particular embodiments of the present description, the battery systems disclosed herein can also include a heat sink structure in fluid communication with the heat transfer fluid. In particular embodiments, the battery system can also be configured to circulate the heat transfer fluid between the heat generating component and the heat sink structure. Suitable heat sink structures can include, for example, a heat sink, a heat spreader, or similar structures capable of removing excess heat from the heat transfer fluid.

[0106] In some or other embodiments of the description, the description also describes methods of providing thermal regulation for a heat-generating component. Such methods can include providing a heat transfer fluid, and operating or placing the heat-generating component in contact with the heat transfer fluid such that the temperature is maintained within a predetermined range. Any of the heat transfer fluids specified in the present application can be used. Operation of the heat-generating component can include any action that causes the heat-generating component to generate heat. For example, for a battery, as discussed in the present application, charging or discharging the battery can facilitate the generation of excess heat. For example, the disclosure of the present application can also be used to address thermal management of other heat-generating components, such as computer processors and other high-power electronic components within a server farm. The disclosure of the present application can also be used to address fast-charging stations for electric vehicles.

[0107] The method can also include contacting the heat transfer fluid with a surface of the heat-generating component. Particular configurations can include disposing the heat transfer fluid in contact with an outer surface of the heat-generating component, including submerging or partially submerging the heat-generating component in the heat transfer fluid. Jacketed configurations of the heat transfer fluid are also within the scope of the disclosure of the present application.

[0108] As described in the present application, the methods of the present description can also include circulating the heat transfer fluid, particularly between the heat-generating component and a suitable heat-dissipating structure.

[0109] Embodiments disclosed in the present application include:

[0110] A. Heat transfer fluid. The heat transfer fluid comprises: a plurality of isomerically branched paraffins comprising a hydrogenation reaction product of one or more linear alpha-olefins (LAOs) oligomerized with a BF3 catalyst system, the plurality of isomerically branched paraffins comprising at least about 90 wt% isomerically branched paraffin dimers; wherein the one or more LAOs have from about 8 to about 12 carbon atoms; and wherein the plurality of isomerically branched paraffins collectively have a Mouromtseff number of from about 10,000 to about 16,000 kg / (s 2.2 ·m 0.6 ·K) at 80 °C, a thermal conductivity of about 0.125 W / m·K or more at 80 °C, and a flash point of about 140 °C or more.

[0111] B. Battery system. The battery system comprises: a battery; and a heat transfer fluid A in contact with the battery.

[0112] C. Electric vehicle. The electric vehicle comprises: a heat-generating component; and a heat transfer fluid A in contact with the heat-generating component.

[0113] D. Thermal management system comprising the heat transfer fluid A, wherein the thermal management system is configured to circulate the heat transfer fluid between a heat-generating component and a heat-dissipating component.

[0114] E. A method of transferring excess heat. The method comprises: providing a heat transfer fluid A; and operating or placing a heat generating component in contact with the heat transfer fluid.

[0115] Embodiments A-E can employ any combination of one or more of the following additional elements:

[0116] Element 1 : wherein the heat transfer fluid comprises at least about 90 wt% isomerically branched paraffins.

[0117] Element 2: wherein the heat transfer fluid comprises a plurality of isomerically branched paraffin dimers formed from C 10 LAO.

[0118] Element 3: wherein the heat transfer fluid comprises at least about 90 wt% isomerically branched paraffin dimers formed from C 10 LAO.

[0119] Element 4: wherein the heat transfer fluid further comprises a plurality of isomerically branched paraffin trimers formed from one or more LAO oligomers using a BF3 catalyst system.

[0120] Element 5: wherein the heat transfer fluid comprises a plurality of isomerically branched paraffin trimers formed from C 10 LAO.

[0121] Element 6: wherein there is about 0.5 wt% to about 2 wt% isomerically branched paraffin trimers.

[0122] Element 7: wherein the heat transfer fluid further comprises at least one fluid selected from the group consisting of Group I base oils, Group II base oils, Group III base oils, Group IV base oils, Group V base oils, and any combination thereof.

[0123] Element 8: wherein the heat transfer fluid further comprises at least one fluid selected from the group consisting of aromatic hydrocarbons, polyalphaolefins, paraffins, isoparaffins, esters, ethers, gas-to-liquid (GTL) base oils, Fischer-Tropsch wax derived base oils, wax derived hydroisomerized base oils, silicone oils, and any combination thereof.

[0124] Element 9: wherein the heat transfer fluid further comprises one or more additives selected from the group consisting of antioxidants, corrosion inhibitors, antifoam agents, antiwear additives, dispersants, detergents, viscosity improvers, and any combination thereof.

[0125] Element 9A: wherein corrosion-causing ions are substantially absent from the plurality of isomerically branched paraffins.

[0126] Element 9B: wherein the heat transfer fluid further comprises at least one phenol-based antioxidant and at least one amine-based antioxidant, preferably wherein the heat transfer fluid comprises at least about 0.25 wt% of at least one phenol-based antioxidant and at least about 0.1 wt% of at least one amine-based antioxidant, or at least about 0.5 wt% of at least one phenol-based antioxidant and at least about 0.2 wt% of at least one amine-based antioxidant.

[0127] Element 10: wherein the heat transfer fluid is in contact with an outer surface of the battery.

[0128] Element 11 : wherein the battery is at least partially submerged in the heat transfer fluid.

[0129] Element 12: wherein the battery comprises a plurality of internal channels configured for circulation of the heat transfer fluid.

[0130] Element 13: wherein the battery system further comprises a heat sink structure in fluid communication with the heat transfer fluid.

[0131] Element 14: wherein the battery system is configured to circulate the heat transfer fluid between the battery and the heat sink structure.

[0132] Element 15: wherein the battery is a lithium-ion battery.

[0133] Element 16: wherein the heat transfer fluid is in contact with an outer surface of the heat-generating component.

[0134] Element 17: wherein the heat-generating component is at least partially submerged in the heat transfer fluid.

[0135] Element 18: wherein the heat-generating component comprises a plurality of internal channels configured for circulation of the heat transfer fluid.

[0136] Element 19: wherein the electric vehicle further comprises a heat sink structure in fluid communication with the heat transfer fluid.

[0137] Element 20: wherein the heat transfer fluid is configured to circulate between the heat-generating component and the heat sink structure.

[0138] Element 21 : wherein the heat-generating component is a battery, a power component, an engine, an engine component, an electronic device, or any combination thereof.

[0139] Element 22: wherein the method further comprises circulating the heat transfer fluid between the heat-generating component and the heat sink structure.

[0140] Element 23: wherein the battery, the power component, the engine, the engine component, or the electronic device is present in an electric vehicle.

[0141] As non-limiting examples, exemplary combinations suitable for A-E include, but are not limited to, 1 and 2; 1 and 3; 1 and 4; 1, 4 and 5; 1, 4 and 6; 1 and 4-6; 1 and 7, 8 and / or 9 or 9B; 2 and 3; 2 and 4; 2-4; 2, 4 and 5; 2, 4 and 6; 2 and 7, 8 and / or 9 or 9B; 2, 3 and 7, 8 and / or 9 or 9B; 2, 4 and 7, 8 and / or 9 or 9B; 2-4 and 7, 8 and / or 9 or 9B; 2-5 and 7, 8 and / or 9 or 9B; 2-4, 6 and 7, 8 and / or 9 or 9B; 2-6 and 7, 8 and / or 9 or 9B; 3 and 4; 3, 4 and 5; 3, 4 and 6; 3 and 4-6; 3 and 7, 8 and / or 9 or 9B; 3, 4 and 7, 8 and / or 9 or 9B; 3, 4, 5 and 7, 8 and / or 9 or 9B; 3, 6 and 7, 8 and / or 9 or 9B; 3, 4, 6 and 7, 8 and / or 9 or 9B; 3-6 and 7, 8 and / or 9 or 9B; 4 and 5; 4 and 6; 4-6; 4, 5 and 7, 8 and / or 9 or 9B; 4, 6 and 7, 8 and / or 9 or 9B; 4-6 and 7, 8 and / or 9 or 9B; 7 and 8; 7 and 9 or 9B; 7-9; and 8 and 9 or 9B. Additional exemplary non-limiting embodiments suitable for B include any of the foregoing suitable for A-E further in combination with 10, 11, 12, 13 and / or 14; any of 1-9 or 9A or 9B further in combination with 10, 11, 12, 13 and / or 14; 10 and 11; 10 and 12; 10 and 13; 10 and 14; 10 and 15; 11 and 13; 11 and 14; 11 and 15; 12 and 13; 12 and 14; 12 and 15; 13 and 14; 13 and 15; and 14 and 15. Additional exemplary non-limiting embodiments suitable for C include any of the foregoing suitable for A-E further in combination with 16, 17, 18, 19, 20 and / or 21; any of 1-9 or 9A or 9B further in combination with 16, 17, 18, 19, 20 and / or 21; 16 and 17; 16 and 18; 16 and 19; 16 and 20; 16 and 21; 17 and 18; 17 and 19; 17 and 20; 17 and 21; 18 and 19; 18 and 20; 18 and 21; 19 and 20; 19 and 21; 20 and 21; 16 or 17 and 19; 16 or 17 and 20; 16 or 17 and 19-21. Additional exemplary non-limiting embodiments suitable for D include any of the foregoing suitable for A-E further in combination with 16, 17, 18, 19, 20 and / or 21; any of 1-9 or 9A or 9B further in combination with 16, 17, 18, 19, 20 and / or 21; and 16 and 17.Additional exemplary non-limiting embodiments applicable to E include any of the foregoing applicable to any of A-E further incorporating 16, 17, 18, 19, 20, 21, 22, and / or 23; any of 1-9 or 9A or 9B further incorporating 16, 17, 18, 19, 20, 21, 22, and / or 23; 16 and 17; 16 and 18; 16 and 19; 16 and 20; 16 and 21; 16 and 22; 16 and 23; 17 and 18; 17 and 19; 17 and 20; 17 and 21; 17 and 22; 17 and 23; 18 and 19; 18 and 20; 18 and 21; 18 and 22; 18 and 23; 19 and 20; 19 and 21; 19 and 22; 19 and 23; 20 and 21; 20 and 22; 21 and 22; 21 and 23; 22 and 23; 16 or 17 and 19; 16 or 17 and 20; 16 or 17 and 19 and 20; 16 or 17 and 19-21; 16 or 17 and 22; and 16 or 17 and 23.

[0142] In order to facilitate a better understanding of the embodiments addressed by the present application, examples of various representative embodiments are set forth. The following examples are in no way to be understood as limiting or defining the scope of the present application. Example

[0143] Example 1: Isomer C formed with BF3 catalyst system 20 Isomer C formed with BF3 catalyst system 10 The commercial feed comprising ~94% C

[0144] Table 3

[0145] Promoter Concentration (mmol / 100 lbs feed) 20 Residence Time (hrs) ～1.7 / 0.7 Pressure (psig) ～5 Temperature (°F) ～73 Conversion (%) ～90

[0146] Once the reaction is complete, the effluent is quenched with an alcohol and filtered through celite to remove the catalyst system and other particulates. The resulting mixture of olefin containing LAO oligomers is further purified by distillation to remove unconverted monomers and obtain LAO dimers of up to about 99.8% purity. Figure 2 An exemplary gas chromatogram of LAO dimers formed with the BF3 catalyst system is shown. About 1.5 wt% of LAO trimers are retained with the LAO dimers to improve clarity after hydrogenation.

[0147] The LAO dimer was further hydrogenated using slurry hydrogenation in the presence of a D-49 Ni / Ni monoxide powder catalyst supported on silica to obtain the corresponding branched paraffin dimer combined with a small amount of branched paraffin trimer. The hydrogenation reaction was carried out at about 230°C and about 650 psi for about 1 hour. The catalyst loading was about 0.5 wt%. The sample contained about 98.3 wt% branched paraffin dimer, about 1.5 wt% branched paraffin trimer, and about 0.3 wt% hydrogenated C 10 The LAO monomer (i.e., decane) was determined by gas chromatography to be about 99.9 wt% as shown. The properties of the sample are listed in Table 4 below. Figure 2

[0148] Table 4

[0149] Kinematic Viscosity (100°C, ASTM D445) 1.7 cSt Kinematic Viscosity (80°C, ASTM D445) 2.3 cSt Kinematic Viscosity (40°C, ASTM D445) 5.1 cSt Kinematic Viscosity (0°C, ASTM D445) 22.1 cSt Kinematic Viscosity (-40°C, ASTM D445) 249 cSt Specific Gravity (15.6 / 15.6°C, ASTM D4052) 0.798 Appearance (-40°C, visual) Transparent and Bright Pour Point (ASTM D5059) -87℃ Flash Point (ASTM D92 - Cleveland Open Cup) 155℃ Density (15.6°C) 0.76 g / cm 3 ]]> Density (80°C) 0.798 g / cm 3 ]]> Specific Heat (20°C) 2.14 kJ / kg-K Thermal Conductivity (80°C) 0.145 W / m-K Dielectric Constant (1 kHz, 25°C) 2.1 Breakdown Voltage (25°C) > 29 kV Electrical Conductivity (25°C) <50 pS / m Volume Resistivity (25°C, 250 V) >2.7x10 14 GΩ·m]]>

[0150] Elemental analysis of the sample by ICP is shown in Table 5 below, which indicates that a high purity paraffin product was obtained. Notably, there is essentially no presence of potentially corrosive ions.

[0151] Table 5

[0152]

[0153]

[0154] Example 2: Formulating Heat Transfer Fluids. The branched paraffin sample from Example 1 was formulated with various additives for additional performance testing. The heat transfer fluid formulations are detailed in Table 6 below. Viscosity performance is expressed as a percentage increase in viscosity performance at room temperature. Data was also collected according to the DKA oxidation test (CEC L-48-00, "Oxidation Stability of Lubricating Oils Use in Automotive Transmissions by Artificial Aging, 160°C, 192 hours"), a commonly used industry standard test.

[0155] Table 6

[0156]

[0157] As shown, the combination of antioxidants provided significantly better performance than either antioxidant alone.

[0158] ​All documents described herein are incorporated by reference herein for all purposes to the same extent as if each individual document was specifically and individually indicated to be incorporated by reference for its entirety. From the foregoing it will be appreciated that, although specific embodiments of the disclosure have been described herein for purposes of illustration, various modifications can be made without deviating from the spirit and scope of the disclosure. Accordingly, it is not intended that the disclosure be limited as illustrated and described herein. For example, the compositions described herein can be devoid of any component or composition not specifically recited or disclosed herein. Any method can lack any step not specifically recited or disclosed herein. Similarly, the term “comprising” is to be read as synonymous with the term “including”. Whenever a method, composition, element or group of elements is preceded by the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0159] One or more exemplary embodiments in connection with one or more inventive aspects are set forth herein. For purposes of summarizing the disclosure, certain aspects, advantages, and novel features of the applications have been described herein. This summary is made for purposes of complying with 37 C.F.R. § 1.73 and is not intended to limit the scope of the disclosure, which is defined solely by the claims. The description set forth herein is a description of exemplary embodiments of the present disclosure and is not intended to represent that the present disclosure will necessarily be constructed as described herein. Numerous specific details are described herein in order to provide a thorough and complete description of the present disclosure. Descriptions of well-known methods, procedures, components and the like are not provided herein in order to not unnecessarily obscure the present disclosure. Well-known methods, procedures and components can have been used to construct and test the present disclosure and by no means will limit the scope of the present disclosure. Furthermore, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes and can not have been selected to expressly convey the scientific and technical meanings of terms used.

[0160] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used herein are to be understood as being modified in all instances by the term "about." Accordingly, unless otherwise indicated, the numerical parameters set forth in the following specification and attached claims are approximations. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical indication is deemed to contain its normal range of experimental error, typically ± 1% or ± 5% of the indicated value. Unless otherwise indicated, all percentages are by weight.

[0161] Whenever a numerical range is disclosed herein such range is inclusive of the numbers and includes any intervening range or intervening whole number. Particular ranges are disclosed herein specifically. Specifically, each numerical range disclosed herein (in the form "about a to about b", or equivalently "about a to b", or equivalently "about a-b") is understood to recite every number and range contained within the broadest range. Also, the terms in the claims have their plain ordinary meaning. Also, the indefinite articles "a" or "an" as used in the claims are defined herein to mean one or more than one of the elements. The application can also include other aspects such as:

[0162] Accordingly, the specification and figures are to be regarded in an illustrative manner and applications implementing those described uses will although not explicitly described benefit from the teachings of this application. Nothing herein is to be construed as limiting the application shown in the claims in any way. It will be readily apparent to those skilled in the art that varying substitutions and modifications can be made to the application disclosed herein, and further applications embodied by the principles of the application might be made without departing from the spirit of the application. Accordingly, it is intended that all such conceivable variations and modifications be included within the scope of the application as described in the following claims.

Claims

1. A method of selecting a heat transfer fluid for use in an electric vehicle, comprising the steps of: determining a Mouromtseff number for a turbulent state of one or more heat transfer fluids and selecting a heat transfer fluid based on the determined Mouromtseff number, wherein the heat transfer fluid comprises: A plurality of isomeric branched paraffins comprising the hydrogenation reaction product of one or more linear alpha-olefins (LAO) oligomerized using a BF3 catalyst system, the plurality of isomeric branched paraffins comprising at least 90 wt% isomeric branched paraffin dimers; wherein the one or more LAOs have 8 to 12 carbon atoms; and wherein the plurality of isomer branched paraffins have a combined mass fraction of 10,000 to 16,000 kg / (s) at 80°C. 2.2 ·m 0.6 ·K), a thermal conductivity of 0.125 W / m·K or higher at 80°C, and a flash point of 140°C or higher.

2. The process of claim 1 wherein the heat transfer fluid comprises at least 90 wt% isomerically branched paraffins.

3. The method according to claim 1, wherein the heat transfer fluid comprises C 10 LAO forms various isomeric branched paraffin dimers.

4. The method according to claim 1, wherein the heat transfer fluid comprises at least 90 wt% of C 10 LAO forms isomeric branched paraffin dimers.

5. The method of claim 1 , wherein the heat transfer fluid further comprises: Multiple isomeric branched paraffin trimers are formed by the oligomerization of one or more LAOs using a BF3 catalyst system.

6. The method according to claim 5, wherein the heat transfer fluid comprises C 10 LAO forms various isomeric branched paraffin trimers.

7. The process of claim 5 wherein 0.5 wt% to 2 wt% of the isomerically branched paraffin trimer is present.

8. The method of claim 1 , wherein the heat transfer fluid further comprises: At least one fluid selected from the group consisting of Group I base oils, Group II base oils, Group III base oils, Group IV base oils, Group V base oils, and any combination thereof.

9. The method of claim 1 , wherein the heat transfer fluid further comprises: At least one fluid selected from aromatic hydrocarbons, polyalphaolefins, paraffins, isoparaffins, esters, ethers, gas-to-liquid (GTL) base oils, Fischer-Tropsch wax derived base oils, wax derived hydroisomerized base oils, silicone oils, and any combination thereof.

10. The method of claim 1, wherein the heat transfer fluid further comprises: One or more additives selected from antioxidants, corrosion inhibitors, defoamers, anti-wear additives, dispersants, detergents, viscosity modifiers, and any combination thereof.

11. The method of claim 1, wherein the plurality of isomeric branched paraffins are free of corrosion-inducing ions.

12. The method of claim 1 , wherein the heat transfer fluid further comprises: at least 0.25 wt% of at least one phenolic-based antioxidant, and At least 0.1 wt% of at least one amine-based antioxidant.

13. The method of claim 1 , wherein the heat transfer fluid further comprises: at least 0.5 wt% of at least one phenolic-based antioxidant, and At least 0.2 wt% of at least one amine-based antioxidant.

14. The method according to any one of claims 1 to 13, wherein the Mouromtseff number Mo is represented by the following formula, where ρ is the fluid density, k is the thermal conductivity, c p is the specific heat, and μ is the dynamic viscosity of the fluid.

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