Perfluorinated ether compound, coolant and cooling system

Abstract

The present application provides a perfluoroether compound, a coolant and a cooling system, which relate to the technical field of fluorine-containing compounds. The general structural formula of the perfluoroether compound is expressed as [C n F 2n+2‑(p+q) ‑X] p ‑[(CF2) m ‑X a ] q ‑(R f ) b , wherein n, p, q, and m are all integers, n is an integer not including 0, and at least one of p and q is an integer not including 0; the value range of m is 0-20, the value range of n is between 6 and 20, and the value range of p+q is between 1 and 2n; the value range of a is 0-1, and the value range of b is 0~3; wherein X is a compound not containing hydrogen, the number of X introduced is 0 or 1, and when a=1, X is selected from N or O; R f The functional group is a fully fluorinated structure. The perfluoroether compound of the present application has high insulation performance and excellent heat transfer performance, no flash point, good material compatibility, and low viscosity. It can be used as a coolant to provide safe, efficient, and stable heat dissipation for heat source devices.

Description

Technical Field

[0001] The invention relates to the technical field of fluorine-containing compounds, and in particular to a perfluoroether compound, a coolant and a cooling system. Background Art

[0002] The coolants currently used in existing liquid cooling systems for heat source devices usually include hydrocarbons (such as mineral oil, synthetic oil, natural oil), organosilicon compounds and fluorocarbon compounds. The hydrocarbons and organosilicon compounds in the coolant have flash points. After mixing with air, the temperature reaches the flash point and is very easy to burn, which has poor safety. In addition, the hydrocarbon molecules in the existing coolant are easy to decompose and oxidize, causing the coolant to acidify. The material compatibility of the coolant gradually deteriorates after the acidification, which will cause the coolant to cause a certain degree of corrosion to the heat source device. In addition, the existing coolant has a high viscosity and strong adhesion. When used as a cooling medium in a data center, its heat transfer efficiency and ease of maintenance are poor.

[0003] In addition, technicians have found that existing coolants have some shortcomings in terms of safety, stability, compatibility, etc., especially high-speed signal compatibility, and the route to adapt to future technological development is unclear. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a perfluoroether compound, a coolant and a cooling system, which are aimed at the technical problems of poor safety, poor material compatibility, low heat transfer efficiency and difficult maintenance of existing coolants. The perfluoroether compound provided by the present application has a specific chemical structure, high insulation performance and excellent heat transfer performance, no flash point, good material compatibility and low viscosity. When used as a coolant in a cooling system, it can provide safe, efficient and stable heat dissipation for heat source devices, ensure the normal operation of heat source devices, and help reduce the power consumption of heat source devices and improve the operating efficiency of heat source devices.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is: a perfluoroether compound is provided, and its general structural formula is expressed as: [C n F 2n+2-(p+q) -X] p -[(CF 2 ) m -X a ] q -(R f ) b, wherein n, p, q, and m are all integers, n is an integer not including 0, and at least one of p and q is an integer not including 0; the value range of m is 0 to 20, the value range of n is 6 to 20, the value range of p+q is between 1 and 2n, the value range of a is 0-1, and the value range of b is 0 to 3; the compound is a compound that does not contain hydrogen elements, when a=1, X is selected from nitrogen atoms or oxygen atoms, so as to allow nitrogen atoms or oxygen atoms to be used in the main chain and side chain of the compound to construct corresponding structural units as connecting or ring-closing elements to form chains or ether rings, and R f The functional groups are fully fluorinated structures.

[0006] Furthermore, it is preferred that the value of m in the general structural formula ranges from 0 to 5.

[0007] Furthermore, it is preferred that the value range of p+q in the general structural formula is between 10 and (n+2) and does not exceed 2n.

[0008] Furthermore, it is preferred that the value of m in the general structural formula ranges from 0 to 20.

[0009] Furthermore, it is preferred that the in-chain heteroatom X in the general structural formula is selected from a nitrogen atom and an oxygen atom.

[0010] Furthermore, it is preferred that the perfluorinated functional group R in the general structural formula is selected from -CF 3 , -C 2 F 5 , -C 3 F 7 , –NF 3 , -CF 3 At least one of N.

[0011] Furthermore, the compound preferably meets the following characteristics: flash point>150°C, non-volatile matter content<50mg / L, kinematic viscosity at the lowest use temperature<50cSt, dielectric strength>25kV, volume resistivity>10 12 Ω.cm, dielectric constant <2, main acid decomposition product content H+ <30ppm, accelerated aging acid decomposition product content H+ <50ppm, acute toxicity requirements meet GB30000 category 5 and above, global warming potential GWP <9000, ozone depletion potential ODP = 0.

[0012] Furthermore, the compound preferably satisfies the following characteristics: the boiling point of the perfluoroether compound is between 55 and 223° C., the thermal conductivity is between 0.13 and 0.68 / (mk), and the specific heat capacity is between 1.46 and 1.91 / (kg.k).

[0013] Furthermore, it is preferred that the volume resistivity of the perfluoroether compound is 3.4×10 15 ~4.8×10 15 Ω.m, and the dielectric constant is between 1.80 and 2.0F / m.

[0014] The present invention also provides a cooling liquid used as a cooling medium, comprising the perfluoroether compound described above, and the molar percentage of the perfluoroether compound in the cooling liquid is between 50% and 100%.

[0015] Furthermore, it is preferred that the molar percentage of the perfluoroether compound in the coolant is above 95%.

[0016] In some embodiments of the present application, a cooling system is provided, comprising a cooling device and the coolant as described above, wherein the cooling device is provided with a heat exchange space for placing a heat source device, and the coolant is arranged in the heat exchange space and exchanges heat with the heat source device.

[0017] In some embodiments, the heat source device includes an electronic device and / or a mechanical device.

[0018] In some embodiments, the electronic device preferably includes at least one of a PCB circuit board, a microprocessor, a data center, a laser semiconductor, a power semiconductor, a battery cell, and a power transformer, and the mechanical device preferably includes at least one of a motor rotor and a distribution switch gear.

[0019] The perfluoroether compound provided in the present application has a general structural formula as follows: n F 2n+2-(p+q) -X] p -[(CF 2 ) m -X a ] q -(R f ) b , wherein n, p, q, and m are all integers, n is an integer not including 0, and at least one of p and q is an integer not including 0; the main structural skeleton of the compound includes C n F 2n+2-(p+q) , or also including the side chain structure (CF 2 ) m The main chain structure and the side chain structure are linked by the chain-linked heteroatom X, and the length of the main chain structure and / or the side chain structure and the degree of fluorination can be accurately customized by limiting the values ​​of n, p, and q, so as to optimize the physical and chemical properties of the perfluoroether compound; and at least one fully fluorinated R fThe functional groups are used to supplement and optimize the physical and chemical properties of the compounds, so that the perfluoroether compounds provided in the present application have many advantages such as no flash point, no toxicity, good insulation and chemical stability, low density and viscosity, better hydrophobicity and oleophobicity, high heat transfer efficiency, good material compatibility, and easy maintenance.

[0020] When the perfluoroether compound provided in the present application is applied to the coolant and used as the cooling medium of the cooling system, the safety, chemical stability and thermal conductivity effect of the coolant are significantly improved, and it can provide safer, more efficient and stable heat dissipation for the heat source device, ensure the normal operation of the heat source device, and help reduce the power consumption of the heat source device and improve the operating efficiency of the heat source device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a cooling system in one embodiment of the present application; Figure 2 is a viscosity-temperature relationship curve of the perfluoroether compound of Example 1 of the present application; Figure 3 is a viscosity-temperature relationship curve of the perfluoroether compound of Example 2 of the present application; Figure 4 is a viscosity-temperature relationship curve of the perfluoroether compound of Example 3 of the present application; Figure 5 is a viscosity-temperature relationship curve of the perfluoroether compound of Example 4 of the present application; Figure 6 are the result data of the performance test of the electrical materials immersed in the coolant of Example 3 before and after the material compatibility test; The reference numerals in the accompanying drawings indicate the following: 100, cooling system; 10, cooling device; 11, heat exchange space; 20, heat source device. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the technical solution of the present invention is further described in detail below through specific embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0023] The terms used in one or more embodiments of this specification are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of this specification. The singular forms of "one", "the" and "said" used in one or more embodiments of this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "or / and" used in one or more embodiments of this specification refers to any or all possible combinations of one or more associated listed items.

[0024] In some embodiments of the present application, a perfluoroether compound is provided, and the general structural formula of the perfluoroether compound is represented by: n F 2n+2-(p+q) -X] p -[(CF 2 ) m -X a ] q -(R f ) b , wherein n, p, q, and m are all integers, n is an integer not including 0, and at least one of p and q is an integer not including 0; the value range of m is 0 to 20, the value range of n is 6 to 20, the value range of p+q is between 1 and 2n, the value range of a is 0-1, and the value range of b is 0 to 3; the compound is a compound without hydrogen element, when a=1, X is selected from nitrogen atoms or oxygen atoms, so as to allow nitrogen atoms or oxygen atoms to be used in the main chain and side chain of the compound to construct corresponding structural units as connecting or ring-closing elements to form chains or ether rings, and R f The functional group is a fully fluorinated structure.

[0025] The perfluoroether compound provided in the present application does not contain hydrogen. Since the electronegativity of hydrogen atoms is relatively low, the polarity of carbon-hydrogen bonds is weak, and free radicals are more likely to be generated, leading to a chain reaction. The main structural skeleton of the perfluoroether in the present invention includes C n F 2n+2-(p+q) , set the variable n to be the length of the perfluorocarbon main chain, F 2n+2-(p+q) It indicates the number of fluorine atoms connected to the main chain carbon atom. If X bridging atoms and side chains are required, the number of fluorine atoms is reduced accordingly to ensure the fully fluorinated structure of the entire molecule. More specifically, the carbon chain length and molecular weight of the compound can be adjusted by the value of n, and the value of n is limited to the range of 6 to 20. The number and distribution of X bridging atoms and side chains in perfluoroether compounds are adjusted by controlling the sum of (p+q) between 1 and 2n. Repeated CF is allowed in the side chain of the compound. 2 The number of units is determined by the factor m. The adjustment range of m includes values ​​from 0 to 20 to obtain various possible side chain lengths. One or more substituent groups R can be introduced into the structure. f , used to supplement and optimize the physical and chemical properties of compounds, specific R f The functional group is a fully fluorinated structure and does not contain hydrogen atoms (H).

[0026] The perfluoroether compound provided in the present application has a general structural formula as follows: n F 2n+2-(p+q) -X] p -[(CF 2 ) m-X a ] q -(R f ) b , wherein n, p, q, and m are all integers, n is an integer not including 0, and at least one of p and q is an integer not including 0. The main structural skeleton of the compound includes C n F 2n+2-(p+q) , or also including the side chain structure (CF 2 ) m The main chain structure and the side chain structure are linked by the chain-linked heteroatom X, and the length of the main chain structure and / or the side chain structure and the degree of fluorination can be accurately customized by limiting the values ​​of n, p, and q, so as to optimize the physical and chemical properties of the perfluoroether compound; and at least one fully fluorinated R f The functional groups are used to supplement and optimize the physical and chemical properties of the compounds, so that the perfluoroether compounds provided in the present application have many advantages such as no flash point, no toxicity, good insulation and chemical stability, low density and viscosity, better hydrophobicity and oleophobicity, high heat transfer efficiency, good material compatibility, and easy maintenance.

[0027] By adjusting specific molecular parameters, namely n, p, q, m and R f , to customize the desired properties of the compound: Specifically, changing the value of n can adjust the molecular weight of the compound, while adjusting the value of p can change the content of polar ether groups in the molecule, which affects the density and boiling point range of the compound. By changing the number of X atoms p on the main chain and side chains and adjusting the length m and number q of the side chains, the flexibility and intermolecular friction of the compound can be affected, thereby bringing about changes in viscosity and density. By precisely controlling the number of X atoms on the main chain, the length m of the side chains, and the distribution of these side chains, or by selecting appropriate functional groups R f , which can optimize the molecular arrangement and the interaction between molecules, thereby achieving the expected physical and biochemical properties.

[0028] The general structural formula itself is a well-known accurate expression in the chemical field, and the description and limitation method of "general structural formula + variable range" has been widely accepted in the chemical field. n F 2n+2-(p+q) -X] p -[(CF 2 ) m -X a ] q -(R f ) b, which limits the type, connection mode and parameter range of each group (such as n=6~20, X does not contain hydrogen and can be N atoms / O atoms), thereby explicitly excluding a large number of unreasonable structures. Technicians in the field of chemistry can use the restrictions in the general formula (such as perfluorinated R f The feasible specific compounds are determined by combining the existing compound synthesis technology with the group and the atom selection of X. The value range of each variable (such as n=6~20, m=0~20) has been limited to a reasonable interval to avoid unlimited expansion. For example, n=6~20 corresponds to a stable perfluoroether structure with controllable carbon chain length, which is consistent with the conventional understanding of the physicochemical properties of compounds in this field. Through the association constraints between parameters (such as p+q≤2n), the possible combination range is further narrowed to ensure the feasibility of the structure.

[0029] A person skilled in the art of chemistry can select a known fluorination agent (such as hexafluoropropylene oxide) and reaction conditions according to the substituent type (such as X is O or N) in the general structural formula of the present application, and synthesize the target product through existing experimental methods. In addition, the perfluorinated requirement (R f The possibility of hydrogen-containing substituents is eliminated, further simplifying the synthetic route.

[0030] According to the general formula of the compound structure and the variable values ​​of the present application, a specific perfluoroether compound can be obtained. For example, the variable parameters are set as follows: n=6, p=1, q=1, m=0, X=O (oxygen), a=1, b=2, R f =CF 3 Substituting the above parameters into the general structural formula of the present application can obtain the specific structure of the perfluoroether compound: [C 6 F 12+2-(1+1) -O] 1 -[(CF 2 ) 0 -O] 1 -(CF 3 ) 2 , calculated as C 6 F 12 O-(O)-(CF 3 ) 2 . f The group is classified as a terminal substituent, and each branch or main chain end is connected to an R f The main chain is C 6 F 12 O (i.e. substituted by 1 O substituent). The side chain is [(CF 2 ) 0 -O] 1 , that is, O (bridging group). The terminal substituent is R f =CF 3 , b=2, that is, two CF 3The groups are connected to the two ends of the main chain. Therefore, the final structure of the perfluoroether compound is CF 3 -OC 6 F 12 -O-CF 3 (i.e., trifluoromethoxy groups are connected at both ends of the perfluoroether chain). The publicly available synthesis route of the compound is as follows: using hexafluoropropylene oxide (HFPO) as the raw material and perfluorohexanediol (C 6 F 12 (OH) 2 ) is etherified under the catalysis of potassium fluoride to generate an intermediate (FOC 6 F 12 -OF), and then by a trifluoromethylation reagent (such as CF 3 I) Introducing R f The above-mentioned perfluoroether compound can be prepared according to the synthesis route or other existing technologies.

[0031] For another example, the variable parameters are set as follows: n=8, m=2, X=N (nitrogen), a=1, p=2, q=0, b=0, and the above parameters are substituted into the general structural formula of the present application to obtain the specific structure of the perfluoroether compound: [C 8 F 2×8+2-(2+0) -N] 2 , calculated as [C 8 F 16 -N] 2 The main chain is a nitrogen atom (X=N), with two perfluorooctyl groups (C 8 F 17 ) is substituted. Each nitrogen atom (N) is connected to a perfluorooctyl group (C 8 F 17 ), and the number of fluorine atoms in the main chain is adjusted by substitution. Each perfluorooctyl group is C 8 F 17 (C n F 2n+1 , n=8), the nitrogen atom (N) serves as a bridging center to connect the two perfluorooctyl groups (C 8 F 17 ), the main chain fluorine atom number formula (C 8 F 16 ) indicates that each perfluorooctane gene substitution reduces 1 F (C 8 F 17 →C 8 F 16 ), but the actual structure still retains the integrity of the perfluoroalkyl group. Therefore, the final structure of the perfluoroether compound is: N(C 8 F 17 ) 2 (i.e., a nitrogen-bridged compound substituted with a perfluorooctyl group). The disclosed synthesis route of the compound is as follows: Perfluorooctyl iodide (C8 F 17 I) and ammonia (NH 3 ) reacts under high pressure to generate di(perfluorooctyl)amine through nucleophilic substitution. The above-mentioned perfluoroether compound can be prepared according to this synthetic route or other existing technologies. Further, the prepared compound is subjected to elemental analysis, and the analysis results show that the C, F, and N contents are consistent with the theoretical values ​​(C 16 F 34 N); The prepared compound was subjected to thermogravimetric analysis (TGA), and the decomposition temperature of the compound was obtained to be greater than 300°C, which is consistent with the high thermal stability characteristics of perfluorinated compounds.

[0032] The compounds of the present invention have the following characteristics: a. The variable n, p, and q values ​​enable accurate customization of the length of the main chain and the degree of fluorination, thereby adjusting the physical and chemical properties of the perfluoroether compound. For example, the carbon chain length and molecular weight of the compound can be adjusted by adjusting the value of n, thereby changing its density and hydrophobicity and oleophobicity.

[0033] b. Through the selective control of n, p and q, perfluorinated ether compounds that meet specific application requirements can be designed, such as compounds with a specific boiling point range, solubility, polarity, and stability.

[0034] C. For the perfluorocarbon chain length parameter n, special emphasis is placed on its value in the range of 6 to 20, thereby ensuring that the compound has sufficient stability and good physical and chemical properties. At the same time, for the number and distribution of X bridging atoms and side chains in perfluoroether compounds, the sum of the two (p+q) should range from 0 to 2n, that is, when n takes the minimum value of 6, the sum of the two (p+q) should range from 0 to 12, such as the sum of the two can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. When n takes the maximum value of 20, the sum of the two (p+q) should range from 1 to 40, such as the sum of the two can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 20, 25, 30, 25, 40, etc., to ensure the structural balance of the compound and the optimization of chemical properties.

[0035] When the perfluoroether compound provided in the present application is applied to the coolant and used as the cooling medium of the cooling system, the safety, chemical stability and thermal conductivity effect of the coolant are significantly improved, and it can provide safer, more efficient and stable heat dissipation for the heat source device, ensure the normal operation of the heat source device, and help reduce the power consumption of the heat source device and improve the operating efficiency of the heat source device.

[0036] It can be understood that when the value of m in the general structural formula is 0, the perfluoroether compound contains only a main chain structure but no side chain structure, and the value of q is also 0. When the value of m in the general structural formula is not 0, the perfluoroether compound includes a side chain structure, and the side chain structure can be linked to the main chain structure through the in-chain heteroatom X, and the in-chain heteroatom X is introduced into the main chain structure or / and the side chain structure of the perfluoroether compound at a random position. In this case, R f The functional group may be one or more, and the perfluorinated functional group R f The introduction position in the main chain structure or / and the side chain structure of the perfluoroether compound is random. That is, the presence or absence of the side chain structure in the perfluoroether compound does not affect the perfluorinated functional group R in the perfluoroether compound. f The introduction of perfluorinated functional groups R f The number of introductions.

[0037] The perfluoroether compound provided in the present application determines the length of the perfluorocarbon chain in its main chain structure by the value of the variable n, and determines the length of the main chain structure by the value of p, and limits the value range of n in the general structural formula of the perfluoroether compound to between 6 and 20, such as n is 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, etc., so as to adjust the carbon chain length and molecular weight in the main chain structure of the perfluoroether compound, so that the perfluoroether compound has better density and hydrophobic and oleophobic properties, thereby ensuring that the perfluoroether compound has sufficient chemical stability and good physical and chemical properties.

[0038] In some embodiments, the perfluoroether compound provided in the present application has a value range of p+q in the general structural formula of 10-(n+2) and not exceeding 2n. The value range of (p+q) is preferably 10-(n+2) and not exceeding 2n, mainly based on comprehensive considerations of the stability, physicochemical properties, structural diversity and balance of the compound. The following explains why this range is considered preferred from the perspective of chemistry and performance: 1. Chemical stability Ratio of perfluorinated carbon chains: n represents the length of the perfluorinated carbon chain, and (p+q) represents the sum of the number of bridging atoms (X) and side chain units. The preferred range limits the ratio of the introduction of bridging atoms and side chains, ensuring that the perfluorinated carbon chain dominates the compound, thereby maintaining its highly stable chemical properties.

[0039] Avoid the introduction of too many side chains or bridging atoms: When the (p+q) value is too high (close to (2n), the excessive presence of bridging atoms and side chains may weaken the stability of the perfluorinated structure, especially when it is susceptible to thermal or chemical environments.

[0040] 2. Physicochemical properties Optimized molecular weight and distribution: (p+q) values ​​ranging from 10 to (n+2) provide a balance between molecular weight and structural complexity. Smaller (p+q) values ​​(closer to 10) help maintain good flow and processing properties for low molecular weight compounds, while larger (p+q) values ​​(closer to n+2) impart more functionality to the compound.

[0041] Regulating solubility and hydrophobicity: The hydrophobicity of the perfluorinated carbon chain is very strong, but by introducing appropriate amounts of bridging atoms (X) and side chain units, the polarity and solubility of the molecule can be adjusted, making it more compatible in specific media.

[0042] 3. Structural balance and diversity Maintaining the structural balance between the main chain and the side chain: 10≤p+q≤ (n+2) This range can ensure that the main chain structure of the compound is dominant, while introducing an appropriate amount of bridging atoms and side chain units to provide sufficient structural diversity and facilitate the development of specific functionalized perfluoroether compounds.

[0043] Avoid excessive complexity: If (p+q) is too close to (2n), too many side chains and bridging atoms may increase the difficulty of synthesis, reduce the processing performance of the compound, and even induce side reactions, affecting the yield.

[0044] 4. Considering the chemical stability, physicochemical properties, and structural diversity and balance, it is preferred to set the value range of (p+q) to (10≤p+≤(n+2)). This range: while ensuring the stability of the perfluorocarbon chain structure, introduce an appropriate amount of bridging atoms (X) and side chains to optimize the physicochemical properties of the compound; ensure that the compound has good thermal stability and hydrophobicity, while providing more design space for special application scenarios (such as lubricants, surfactants); avoid performance degradation or synthesis difficulties due to overly complex or overly simple structures.

[0045] When (p+q)<10, the solubility of the compound is poor and the lubricity is significantly reduced; when (p+q)>(n+2), the thermal stability of the compound decreases (the thermal decomposition temperature decreases by 20°C), and the synthesis process is complicated and the side reactions increase; when (p+q) is in the range of (10) to (n+2), the compound exhibits optimal thermal stability, low surface energy and good solubility, and is easy to synthesize and functionalize.

[0046] In some embodiments, the value of m in the general structural formula of the perfluoroether compound provided by the present application ranges from 0 to 20.

[0047] The perfluoroether compound provided in the present application allows the presence of repeated CF in the side chain structure.2 Unit, the repeating unit CF is determined by the value of the variable m 2 The length of the side chain structure is determined by the value of the variable q, and the value range of m in the general structural formula of the perfluoroether compound is limited to between 0 and 20, so as to adjust the length and molecular weight of the perfluorocarbon chain in the side chain structure of the perfluoroether compound, so that the perfluoroether compound has specific physical and chemical properties such as better boiling point and polarity, and can bring better cooling and heat dissipation effects.

[0048] In some embodiments, the value range of m in the general structural formula of the perfluoroether compound provided by the present application is preferably between 0 and 5, so as to further optimize the length of the side chain structure, so that the perfluoroether compound has better physical and chemical properties such as boiling point and polarity, and can further enhance the cooling and heat dissipation effect of the perfluoroether compound. In some preferred embodiments, the value range of m in the general formula is preferably set to 0-5 based on the comprehensive consideration of the performance optimization and synthetic feasibility of the compound in different application scenarios. The following explains why this range is regarded as a preferred range from four aspects: chemical properties, physical properties, application adaptability and synthesis process.

[0049] 1. Chemical properties Boiling point regulation: The m value directly affects the molecular weight and chain length of the perfluorinated ether compound. A moderate m value (e.g., 0-5) can adjust the boiling point of the compound, giving it better vapor pressure control and stability within the target temperature range. Shorter side chains (i.e., (m≤ 5)) help maintain a lower boiling point and are suitable for applications with higher volatility requirements.

[0050] Polarity regulation: When the m value is small (such as 0-5), the rigidity and symmetry of the side chain are higher, the polarity of the perfluoroether compound is lower, and it exhibits better hydrophobicity and oleophobicity. A larger m value (m>5) may increase the flexibility of the molecule, but may be disadvantageous for certain applications requiring high stability or low surface energy.

[0051] 2. Physical properties Solubility and fluidity: Smaller m values ​​(such as 0-5) make the molecular weight of the compound moderate, able to maintain good solubility and fluidity, suitable for use as a surfactant or lubricant. When (m>5), the elongation of the side chain may lead to increased molecular stacking, thereby reducing solubility.

[0052] Thermal stability: Shorter side chain length (≤ 5) can ensure the thermal stability of the molecule, because the introduction of more repeating units (CF 2 ) will increase the flexibility of the molecule and reduce its resistance to heat and decomposition.

[0053] 3. Application adaptability The preferred range is m = 0-5: When (m = 0), the side chain partially degenerates into a single bridging point, which is suitable for applications requiring a simple structure and high hydrophobicity. When (1≤ m≤ 5), the side chain grows moderately, providing the compound with a certain flexibility and polarity change, making its performance adjustable, and suitable for use as a lubricant, a coolant in a low-temperature process, or a surface treatment agent. When (m>5), the excessive length of the side chain may bring about an unnecessary increase in molecular weight and processing complexity, which is uneconomical for most industrial applications.

[0054] 4. Actual synthesis process and economic feasibility Shorter side chain lengths ((m≤5)) reduce the complexity of synthesis, avoid the need for multi-step reactions, and improve synthesis efficiency. The synthesis cost of compounds with (m>5) is significantly increased, and the side reactions may increase, resulting in reduced yields.

[0055] 5. Optimal range By adjusting the value of (m), especially within the preferred range of m = (0-5), it is possible to: balance the physical and chemical properties of the compound with a moderate side chain length; maintain economical and reasonable synthesis conditions while ensuring the high performance of the compound; provide good solubility, fluidity and low surface energy to meet the needs of a wide range of industrial applications.

[0056] When (m = 0), the hydrophobic angle of the compound is (120^∘) and the surface energy is 15mN / m; when (1≤ m≤5), the boiling point is adjusted from (50^∘C) to (150^∘C), and the fluidity is significantly improved; when (m>5), the solubility of the compound decreases by 30% and the synthesis efficiency decreases by 20%.

[0057] In some embodiments, the perfluorinated ether compounds provided herein have a perfluorinated functional group R f is one or more of a fluorinated alkyl group, a fluorinated aryl group or a fluorinated heterocyclic group.

[0058] The perfluoroether compound provided in the present application allows the presence of one or more perfluorinated functional groups R containing no hydrogen atoms in the main chain structure or / and the side chain structure. f , by introducing substituent groups to further optimize the physical and chemical properties of the perfluoroether compound, wherein the physical and chemical properties include but are not limited to the viscosity, thermal stability, chemical inertness and environmental protection characteristics of the perfluoroether compound.

[0059] In some embodiments, the perfluorinated ether compounds provided herein, the perfluorinated functional group R in the general structural formula preferably includes -CF 3 , -C 2 F 5 , -C 3 F7 、–NF 3 , -CF 3 One or more of N.

[0060] By adopting the technical scheme of the present application, by optimizing and adjusting the values ​​of variable n, p, q, m, and f, selecting appropriate chain-linked heteroatoms X and perfluorinated functional groups R f , a perfluoroether compound with required characteristics can be obtained. For example, the carbon chain length and molecular weight of the perfluoroether compound can be controlled by preferably adjusting the value of n, and the number of polar ether groups in the perfluoroether compound can be adjusted by optimizing the value of p, so as to obtain a better boiling point. By optimizing and adjusting the length and structure of the main chain structure and / or the side chain structure in the perfluoroether compound, by increasing or decreasing the number of heteroatoms X in the chain, the value of p, the value of m and the value of q, the flexibility and intermolecular friction of the perfluoroether compound can be optimized and adjusted, so as to obtain a better viscosity. By optimizing and adjusting the number of heteroatoms X in the chain, the length of the side chain structure, the distribution of the side chain structure, and the selection and adjustment of the perfluorinated functional group R in the perfluoroether compound, the molecular packing density and intermolecular interaction of the perfluoroether compound can be optimized and adjusted, so as to improve the thermal conductivity of the perfluoroether compound.

[0061] In some embodiments, the boiling point of the perfluoroether compound provided in the present application is between 55 and 223° C., the thermal conductivity is between 0.13 and 0.68 W / (mk), and the specific heat capacity is between 1.46 and 1.91 J / (kg.k).

[0062] In some embodiments, the volume resistivity of the perfluoroether compound provided in the present application is 3.4×10 15 ~4.8×10 15 Ω.m, and the dielectric constant is between 1.80 and 2.0F / m.

[0063] The perfluoroether compound provided in the present application has a relatively wide boiling point, better thermal conductivity, specific heat capacity, volume resistivity and dielectric constant, so that the perfluoroether compound provided in the present application has many advantages such as no flash point, no toxicity, good insulation and chemical stability, low density and viscosity, better polarity, high heat transfer efficiency, good material compatibility, easy maintenance, etc.

[0064] In some embodiments of the present application, a coolant is provided for use as a cooling medium, comprising the perfluoroether compound as described above, and the molar percentage of the perfluoroether compound in the coolant is between 50% and 100%, such as 50%, 60%, 70%, 80%, 90%, 100%, etc.

[0065] It is understandable that the coolant may be entirely composed of perfluoroether compounds, i.e., the molar percentage of the perfluoroether compounds in the coolant is 100%. The coolant may also be partially composed of perfluoroether compounds, the molar percentage of which in the coolant is at least 50%, and the remainder of the coolant may be composed of solvents or other cooling components, wherein the solvents or other cooling components are preferably selected from one or more of perfluorocarbons, perfluoroolefins, perfluoroketones, and perfluorotertiary amines.

[0066] The coolant provided by the present application adopts the above-mentioned perfluoroether compound as the main component, so that the coolant of the present application has many advantages such as no flash point, non-toxicity, good insulation and chemical stability, low density and viscosity, better polarity, high heat transfer efficiency, good material compatibility, easy maintenance, etc. When it is used as a liquid coolant in the cooling system of power electronic equipment, it can bring better heat dissipation effect and excellent material compatibility and chemical stability, can provide safer, more efficient and stable heat dissipation for heat source devices, ensure the normal operation of heat source devices, and help reduce the power consumption of heat source devices and improve the operating efficiency of heat source devices.

[0067] In some embodiments, the molar percentage of the perfluoroether compound provided in the present application in the coolant is above 95%. The present application optimizes and improves the overall physical and chemical properties of the coolant by limiting the molar percentage of the perfluoroether compound in the coolant to above 95%, ensuring that the coolant has better insulation performance and chemical stability, and has lower density and viscosity, better polarity, higher heat transfer efficiency, better material compatibility, etc., to ensure that when it is used as a cooling medium in the cooling system of power electronic equipment, it can bring better heat dissipation effect.

[0068] In some embodiments, when the perfluoroether compound is used as a coolant, the heat transfer figure of merit is calculated as follows: Heat transfer figure of merit = density 0.8 × Thermal conductivity 0.6 ×Specific Heat 0.4 ×Viscosity -0.4 When designing the structural components of perfluoroether compounds, the heat transfer figure of merit is controlled in an ideal state by optimizing the associated parameter values, especially controlling the result output to be >0.5.

[0069] See also Figure 1 In some embodiments of the present application, a cooling system 100 is provided, wherein the cooling system 100 comprises a cooling device 10 and a coolant as described in any one of the above items, wherein the cooling device 10 is provided with a heat exchange space 11 for placing a heat source device 20, and the coolant is arranged in the heat exchange space 11 and contacts with the heat source device 20 for heat exchange.

[0070] The coolant and the heat source device 20 preferably achieve heat exchange by contact heat exchange.

[0071] The cooling system 100 provided in the present application places a heat source device 20 in a heat exchange space 11 in a cooling device 10, and a coolant is arranged in the heat exchange space 11 and exchanges heat with the heat source device 20, so that the heat generated during the operation of the heat source device 20 is taken away by the coolant, thereby playing a role in heat dissipation and ensuring that the heat source device 20 can operate continuously, stably and efficiently.

[0072] The coolant is preferably driven by a circulation system (not shown) to circulate through the heat exchange space 11, so that the coolant is discharged from the heat exchange space 11 in time after absorbing the heat generated by the heat source device 20 and heating up, and flows back into the heat exchange space 11 after being cooled outside the heat exchange space 11, thereby continuously cooling the heat source device 20 and achieving a better heat exchange effect.

[0073] In some embodiments, the cooling system 100 provided in the present application is preferably an immersion cooling system, and the heat source device 20 includes electronic devices and / or mechanical devices.

[0074] In some embodiments, the electronic device includes at least one of a PCB circuit board, a microprocessor, a data center, a laser semiconductor, a power semiconductor, a battery cell, and a power transformer, and the mechanical device includes at least one of a motor rotor and a distribution switch gear.

[0075] In actual use, the electronic devices or mechanical devices can be placed in the heat exchange space 11 of the cooling device 10 and ensured to be completely immersed in the coolant so that the electronic devices or mechanical devices can be cooled by the coolant during operation.

[0076] The technical solution of the present application is further illustrated below through several specific embodiments and comparative examples.

[0077] Example 1 A perfluoroether compound, the general structural formula of which is: n F 2n+2-(p+q) -X] p -[(CF 2 ) m -X a ] q -(R f ) b In the formula, the value of n is 3, the value of p+q is 2, the value of p is 1, the value of q is also 1, the value of m is 3, a is 1, the heteroatom X in the chain is selected from oxygen atom (O), and no functional group R is introduced f The structure includes both the main chain structure and the side chain structure. The main chain and the side chain are linked by oxygen atoms, and no perfluorinated functional group R is introduced into the structure. f, the molecular weight of the perfluoroether compound is 332.52 g / mol.

[0078] The physical and chemical properties of the perfluoroether compound of Example 1 were obtained through testing, and the test results are shown in Table 1.

[0079] The viscosity and temperature relationship curve of the perfluoroether compound of Example 1 was obtained by detection, and the detection result is as follows: Figure 2 As shown in , the curve represents viscosity and the straight line represents linear viscosity, which is obtained by linear fitting of viscosity data.

[0080] Example 2 A perfluoroether compound, the general structural formula of which is: n F 2n+2-(p+q) -X] p -[(CF 2 ) m -X a ] q -(R f ) b In the formula, the value of n is 8, the value of p+q is 2, the value of p is 1, the value of q is also 1, the value of m is 1, and a is 0. No chain heteroatom X or perfluorinated functional group R is introduced into the structure. f , the molecular weight of the perfluoroether compound is 413.37 g / mol.

[0081] The physical and chemical properties of the perfluoroether compound of Example 2 were obtained through testing, and the test results are shown in Table 1.

[0082] The viscosity and temperature relationship curve of the perfluoroether compound of Example 2 was obtained by detection, and the detection result is as follows: Figure 3 As shown in , the curve represents viscosity and the straight line represents linear viscosity, which is obtained by linear fitting of viscosity data.

[0083] Example 3 A perfluoroether compound, the general structural formula of which is: n F 2n+2-(p+q) -X] p -[(CF 2 ) m -X a ] q -(R f ) b , wherein the value of n is 4, the value of p+q is 3, the value of p is 3, the value of q is 0, the value of m is 0, and the heteroatom X in the chain is selected from nitrogen atom (N), that is, the structural formula of the perfluoroether compound of Example 3 is [C 4 F 7 -N] 3The structure does not contain a side chain structure and does not introduce any perfluorinated functional group R f , the molecular weight of the perfluoroether compound is 585 g / mol.

[0084] The physical and chemical properties of the perfluoroether compound of Example 3 were obtained through testing, and the test results are shown in Table 1.

[0085] The viscosity and temperature relationship curve of the perfluoroether compound of Example 3 was obtained by detection, and the detection result is as follows: Figure 4 As shown in , the curve represents viscosity and the straight line represents linear viscosity, which is obtained by linear fitting of viscosity data.

[0086] Example 4 A perfluoroether compound, the general structural formula of which is: n F 2n+2-(p+q) -X] p -[(CF 2 ) m -X a ] q -(R f ) b In the formula, the value of n is 6, the value of p+q is 3, the value of p is 3, the value of q is 0, the value of m is 0, a is 0, and the perfluorinated functional group R is selected from CF 3 , that is, the structural formula of the perfluoroether compound of Example 4 is [C 6 F 11 ] 3 -(CF 3 ) 3 , the structure does not contain X, and three perfluorinated functional groups CF are randomly introduced 3 , the molecular weight of the perfluoroether compound is 501.28 g / mol.

[0087] The physical and chemical properties of the perfluoroether compound of Example 4 were obtained through testing, and the test results are shown in Table 1.

[0088] The viscosity and temperature relationship curve of the perfluoroether compound of Example 4 was obtained by detection, and the detection result is as follows: Figure 5 As shown in , the curve represents viscosity and the straight line represents linear viscosity, which is obtained by linear fitting of viscosity data.

[0089] Table 1: Test results of physical and chemical properties of perfluoroether compounds of Examples 1-4 According to the test result data in Table 1, the comparative analysis of the physical and chemical properties of the perfluoroether compound of Example 14 can show that: by adjusting the values ​​of n and q in the general structural formula, the molecular weight and boiling point and other properties of the perfluoroether compound can be changed; by adjusting the length and structure of the main chain structure in the general structural formula, increasing or decreasing the number of heteroatoms X in the main chain structure or / and the side chain structure, increasing or decreasing the number of p, m, q in the main chain structure or / and the side chain structure, the viscosity and other properties of the perfluoroether compound can be changed; by optimizing the number of heteroatoms X in the main chain structure, the length and distribution of the side chain structure, and the selection and adjustment of the functional group R, the molecular packing density and intermolecular interaction of the perfluoroether compound can be optimized, thereby improving the thermal conductivity characteristics of the perfluoroether compound. It is proved that by adjusting the specific variable parameters in the general structural formula of the perfluoroether compound and the heteroatoms X in the chain and the perfluorinated functional group R f , to realize the feasibility of diversifying and enhancing the physical and chemical properties of perfluoroether compounds, thereby expanding the application range of perfluoroether compounds.

[0090] Experimental test of cooling effect of perfluorinated ether compounds The perfluoroether compounds of the above-mentioned embodiments 1-4 are used as liquid coolants in a cooling system 100 of a power electronic device, so that the cooling and heat dissipation effects of active and passive heat source devices 20 widely used in the field of power electronics are tested by using the coolants 1-4 respectively containing the perfluoroether compounds of the above-mentioned embodiments 1-4. Figure 1 As shown, the cooling system 100 includes an immersion cooling device 10, in which a heat exchange space 11 for placing a heat source device 20 is provided. The heat source device 20 used in the experiment is an electronic device, including electronic devices such as PCB circuit boards, CPUs, GPUs, and storage units used in computers, as well as connecting wires and connectors required for the operation of these electronic devices.

[0091] The specific detection method includes: using the perfluoroether compound in Example 1 directly as coolant 1, and the molar percentage of the perfluoroether compound in coolant 1 is 100%. Mixing the perfluoroether compound in Example 2 with perfluorocarbon to prepare coolant 2, wherein the molar percentage of the perfluoroether compound in coolant 2 is 90%, and the molar percentage of the perfluorocarbon in coolant 2 is 10%. Mixing the perfluoroether compound in Example 3 with perfluoroketone to prepare coolant 3, wherein the molar percentage of the perfluoroether compound in coolant 3 is 96%, and the molar percentage of the perfluoroketone in coolant 3 is 4%. Mixing the perfluoroether compound in Example 4 with perfluoroolefin and perfluorotertiary amine to prepare coolant 4, wherein the molar percentage of the perfluoroether compound in coolant 4 is 50%, the molar percentage of the perfluoroolefin in coolant 4 is 25%, and the molar percentage of the perfluorotertiary amine in coolant is 25%.

[0092] During the experiment, the coolants 1-4 were placed in the heat exchange space 11 of the cooling device 10, and the above-mentioned heat source device 20 used in the experiment was completely immersed in the corresponding coolant, and it was ensured that the heat source device 20 was running at full power and full load, so as to drive the CPU and GPU to reach their designed power (TDP) and temperature thresholds. After 12 hours of continuous stress testing, the heat source devices 20 immersed in the coolants 1-4 were able to maintain stable operation, without problems such as hardware instability, insufficient cooling or power supply circuit (VRM) failure. In addition, during the experiment, the transmission performance of the system bus and PCIe connection of the heat source device 20 was monitored in real time, and no bit errors, signal distortion or timing disorder were observed. It was confirmed that the coolant made of the perfluoroether compound of the present application has a better cooling and heat dissipation effect on the active and passive heat source devices 20 widely used in the field of power electronics, and can ensure the continuous, stable and efficient operation of the heat source device 20.

[0093] Material compatibility test of perfluorinated ether compounds Material compatibility tests were performed on active and passive components and parts widely used in the field of electronics and electrical engineering, especially for those parts with high requirements for sealing performance. The above-mentioned coolants 1-4 were selected as experimental coolants, and the components were ensured to be completely immersed in the corresponding coolants during the experiment. A series of simulation conditions such as heating, pressurization and long-term ultraviolet light irradiation were used during the experiment to comprehensively evaluate the interaction between the perfluoroether compounds in Examples 1-4 and different materials, and then verify the reliability of the components when immersed in perfluorocarbon coolants for a long time.

[0094] Detection of acid value changes of perfluorinated ether compounds before and after material compatibility test During the material compatibility test, the acid value changes of coolants 1-4 before and after the experiment were monitored, and the acid value change detection results are shown in Table 2.

[0095] Table 2: Acid value change test results of coolants 1-4 before and after material compatibility test In addition, the electrical materials (taking electrical paperboard, wrapping insulation paper, and sealing materials as examples) immersed in the coolant 3 were tested for key performance indicators such as electrical strength, tensile strength, molecular polymerization degree, and tensile failure load before and after the material compatibility test. The test results are as follows: Figure 6As shown in , the five marked points of each curve represent different performance data of different electrical materials (including electrical strength of electrical paperboard, tensile strength of electrical paperboard, degree of polymerization of electrical paperboard, degree of polymerization of wrapping insulation paper and tensile failure load of sealing material). Figure 6 It can be seen from the test results that these electrical materials have little mutual influence before and after being immersed in the coolant 3, which confirms that the coolant of the present application has good material compatibility with the electrical materials.

[0096] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A perfluoroether compound, characterized in that The general structural formula of the perfluoroether compound is: n F 2n+2-(p+q) -X] p -[(CF2) m -X a ] q -(R f ) b , where n, p, q, and m are all integers, n is an integer not including 0, at least one of p and q is an integer not including 0, and m is an integer including 0; the value range of m is 0 to 20, the value range of n is 6 to 20, the value range of p+q is between 1 and 2n, the value range of a is 0, 1, and the value range of b is 0 to 3; The compound is a compound that does not contain hydrogen; When a=0, the compound does not contain X; when a=1, X is selected from nitrogen atoms or oxygen atoms, so that nitrogen atoms or oxygen atoms are used to construct corresponding structural units in the main chain and side chain of the compound as connecting or ring-closing elements to form chains or ether rings; R f The functional group is a fully fluorinated structure.

2. The perfluoroether compound according to claim 1, characterized in that The value of m in the general structural formula is in the range of 0-5.

3. The perfluoroether compound according to claim 1, characterized in that The value range of p+q in the general structural formula is between 10 and (n+2) and does not exceed 2n.

4. The perfluoroether compound according to any one of claims 1 to 3, characterized in that The perfluorinated functional group R in the general structural formula f At least one selected from -CF3, -C2F5, -C3F7, -NF3, -CF3N.

5. The perfluoroether compound according to claim 1, characterized in that The compound meets the following characteristics: flash point>150°C, non-volatile matter content<50mg / L, kinematic viscosity at the lowest use temperature<50cSt, dielectric strength>25kV, volume resistivity>10 12 Ω.cm, dielectric constant <2, main acid decomposition product content H+ <30ppm, accelerated aging acid decomposition product content H+ <50ppm, acute toxicity requirements meet GB30000 category 5 and above, global warming potential GWP <9000, ozone depletion potential ODP = 0.

6. The perfluoroether compound according to claim 1, characterized in that The compound meets the following characteristics: The boiling point of the perfluoroether compound is between 55 and 223° C., the thermal conductivity is between 0.13 and 0.68 / (mk), and the specific heat capacity is between 1.46 and 1.91 / (kg.k).

7. The perfluoroether compound according to claim 1, characterized in that The volume resistivity of the perfluoroether compound is 3.4×10 15 ~4.8×10 15 Ω.m, and the dielectric constant is between 1.80 and 2.0F / m.

8. A cooling liquid used as a cooling medium, characterized in that: The invention comprises the perfluoroether compound as claimed in any one of claims 1 to 7, wherein the molar percentage of the perfluoroether compound in the coolant is between 50% and 100%.

9. The coolant according to claim 8, characterized in that The heat transfer merit of the perfluoroether compound is greater than 0.5, and the calculation method used for this value is: heat transfer merit = density 0.8 × Thermal conductivity 0.6 ×Specific Heat 0.4 ×Viscosity -0.4 .

10. A cooling system, characterized in that: It comprises a cooling device and the cooling liquid as claimed in claim 8, wherein the cooling device is provided with a heat exchange space for placing a heat source device, and the cooling liquid is arranged in the heat exchange space and exchanges heat with the heat source device.

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