Poly (trialkylsilyl) substituted siloxane, preparation method thereof and application of poly (trialkylsilyl) substituted siloxane in immersion cooling liquid

Abstract

The invention relates to the technical field of organic silicon cooling liquid, and discloses poly (trialkyl silicon) substituted siloxane, a preparation method thereof and application of the poly (trialkyl silicon) substituted siloxane in immersion cooling liquid, the preparation method comprises the following steps: trialkyl silicon acetate and alkoxy silane are subjected to transesterification under the action of a catalyst, and the poly (trialkyl silicon) substituted siloxane is obtained. The poly (trialkyl silicon) substituted siloxane is obtained. The prepared poly (trialkylsilane) substituted siloxane is low in viscosity, high in boiling point, high in flash point, low in freezing point and good in stability, does not need to be compounded with a fluorinated liquid, can be independently used as an immersion cooling liquid and is applied to immersed heat dissipation of a chipset, and the preparation method is simple, efficient and suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of organosilicon coolants, and in particular to a poly(trialkylsilicon)-substituted siloxane and a preparation method thereof, and application thereof in immersion coolants. Background Art

[0002] Liquid cooling has begun to be used as an alternative to air cooling in data centers, but existing technical routes all have unavoidable defects. For example, patent CN115956110A discloses a direct single-phase immersion coolant liquid, specifically a renewable alkane composition of alkanes in the range of C16-C19, which is used for direct cooling of electronic devices. Although hydrocarbon coolants are low in cost, their flash points are usually relatively low. Hydrocarbons with high flash points have relatively large viscosities and poor heat dissipation capabilities. Secondly, the freezing point of common coolants is around minus 40 degrees, which is difficult to achieve with high flash point hydrocarbons. In addition, hydrocarbons are soluble in polyethylene, polypropylene, and polyacrylate compounds, and devices made of such compounds cannot be cooled using hydrocarbon coolants.

[0003] For example, fluorinated liquid can also be used as a liquid coolant, but its cost is high. In recent years, the main patents have focused on the reaction of compatible siloxanes with hydrofluoric acid. Patent CN113717699A discloses a composition, a silicon-containing liquid coolant, a preparation method thereof, and an immersion cooling system, which uses trifluoromethylpropyl silicone oil and fluorocarbon compounds to improve the compatibility of fluorinated coolants. Patent CN113717698A discloses a composition, a fluorinated olefin polymer liquid coolant, a preparation method thereof, and an immersion cooling system. The provided composition includes the following components: fluorocarbon compounds, tetrafluoroethylene polymers, 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, and PFPE double-terminal silane. Siloxane can react quantitatively with hydrogen fluoride to generate fluorosilane. Therefore, the use of siloxanes compatible with fluorinated liquids and adding them to fluorinated liquid immersion coolants can solve the problem of acid reflux of fluorinated liquids. However, the domestic technology level is difficult to achieve long-term stability without acid reflux, and fluorinated liquid is not environmentally friendly and is a persistent pollutant.

[0004] The organic side groups in the polysiloxane molecule can rotate freely around the Si-O main chain, with small intramolecular and intermolecular forces and good molecular flexibility, making polysiloxane the polymer with the lowest glass transition temperature in the known field of polymer science, and also a traditional high and low temperature thermal conductive medium. Polysiloxane has a high flash point, good insulation, no swelling to epoxy compounds, and good compatibility with circuit systems. Silicone immersion coolant has excellent thermal conductivity, which can achieve more efficient and economical heat dissipation, and its ultra-low global warming potential (GWP) will not damage the ozone layer. Silicone immersion coolant has obvious advantages in environmental protection, performance and operating costs. With high thermal conductivity, high specific heat, low specific gravity and relatively low viscosity, this product can solve the problems of high power density heat dissipation and thermal management; in addition, it can save pump power and improve the efficiency of power utilization. Silicone immersion coolant is specially designed for data center equipment such as servers. Its energy efficiency is significantly better than that of traditional air cooling systems, which helps to improve the comprehensive computing power of servers and reduce the floor space and energy consumption of data center infrastructure. In addition, it can be easily recycled and is environmentally friendly. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a poly(trialkylsilicon)-substituted siloxane and a preparation method thereof, and application in immersion coolant. The poly(trialkylsilicon)-substituted siloxane is a small molecule compound with low viscosity, high boiling point, high flash point, low freezing point, and good stability. It is suitable for immersion coolant and can be used for immersion heat dissipation of chipsets. The preparation method thereof is simple and efficient, and is suitable for large-scale production.

[0006] The purpose of the present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a poly(trialkylsilyl)-substituted siloxane, wherein the poly(trialkylsilyl)-substituted siloxane has the structural formula: or, or, or, or, or, Among them, R1, R2, R3, R4, R5, R6, R7 and R8 may be the same as or different from each other, and are each independently phenyl, benzyl, phenethyl, nitrile ethyl, nitrile, methoxyethyl, ethoxyethyl, an alkyl group having 1 to 16 carbon atoms, or a partially fluorinated alkyl group having 1 to 16 carbon atoms.

[0007] Preferably, the alkyl group has 1 to 8 carbon atoms; and the partially fluorinated alkyl group has 1 to 8 carbon atoms.

[0008] In a second aspect, the present invention also provides a method for preparing a poly(trialkylsilyl)-substituted siloxane, comprising the following steps: using trialkylsilyl acetate and alkoxysilane in the presence of a catalyst to carry out an ester exchange reaction to obtain a poly(trialkylsilyl)-substituted siloxane.

[0009] Preferably, the mass ratio of the trialkyl silane acetate to the alkoxysilane is 1 to 15:1, more preferably 5 to 15; and the added amount of the catalyst is 0.1 to 10% relative to the mass of the trialkyl silane acetate.

[0010] Preferably, the alkoxysilane includes alkyltrialkoxysilane, tetraalkoxysilane, dialkyltetraalkoxydisiloxane, hexaalkoxydisiloxane, trialkylhexaalkoxytrisiloxane or octaalkoxytrisiloxane.

[0011] Preferably, the structural formula of the trialkyl silyl acetate is: Wherein, R is phenyl, benzyl, phenethyl, nitrileethyl, nitrile, methoxyethyl, ethoxyethyl, alkyl having 1 to 16 carbon atoms or partially fluorinated alkyl having 1 to 16 carbon atoms.

[0012] Preferably, the alkyl group has 1 to 8 carbon atoms; and the partially fluorinated alkyl group has 1 to 8 carbon atoms.

[0013] Preferably, the catalyst comprises one or more of sulfuric acid, trifluoromethanesulfonic acid, perfluoroalkylsulfonic acid, perfluoro hydrogen sulfonate resin, bis(trifluoromethylsulfonyl)amide and hydrogen sulfonate resin.

[0014] Preferably, the temperature of the transesterification reaction is 40 to 200° C. and the time is 10 to 50 hours.

[0015] Preferably, after the transesterification reaction is completed, the finished product is obtained through steps such as catalyst separation, water washing, alkali washing, water washing, drying, and filtering.

[0016] In a third aspect, the present invention also provides a use of a poly(trialkylsilyl)-substituted siloxane in an immersion coolant.

[0017] Compared with the prior art, the present invention has the following beneficial effects: the poly (trialkylsilicon) substituted siloxane prepared in the present invention has low viscosity, high boiling point, high flash point, low freezing point and good stability, does not need to be compounded with fluorinated liquid, can be used alone as an immersion coolant, and is applied to immersion heat dissipation of chipsets, and its preparation method is simple and efficient, and is suitable for large-scale production. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is described below with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0019] Example 1 The structural formula of trimethylsilyl acetate is: Wherein, R is a methyl group.

[0020] 100 kg of trimethylsilyl acetate was added to a stainless steel reactor, and 15 kg of methyl orthosilicate and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 12 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of methyl orthosilicate was completely replaced by trimethylsilyloxy. Excess trimethylsilyl acetate and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0021] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight of sodium carbonate solution with mass concentration of 0.1%. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetra(trimethylsilyl)siloxane. The product has a boiling point of 120℃, a flash point of 103℃, a viscosity of 2.8 centistokes and a freezing point of -65℃ under 5mm mercury pressure.

[0022] Example 2 The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0023] 100 kg of dimethylethyl silicic acid was added to a stainless steel reactor, and 15 kg of methyl orthosilicate and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 16 hours, and the byproduct methyl acetate was slowly evaporated. The methoxyl groups of methyl orthosilicate were completely replaced by dimethylethylsilyloxy groups. Excess dimethylethyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0024] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetra(dimethylethylsilyl)siloxane. The product has a boiling point of 126°C, a flash point of 112°C, a viscosity of 3.0 centistokes and a freezing point of -80°C at a pressure of 5 mm mercury.

[0025] Example 3 The structural formula of dimethylpropyl silicic acid ester is: Wherein, R is propyl.

[0026] 100 kg of dimethylpropyl silicic acid was added to a stainless steel reactor, and 15 kg of ethyl orthosilicate and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 18 hours, and the byproduct ethyl acetate was slowly evaporated. The ethoxy group of ethyl orthosilicate was completely replaced by dimethylpropyl siloxy. Excess dimethylpropyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0027] Wash the crude product three times with an equal weight of water, collect the upper oil and wash it once with an equal weight of 0.1% sodium carbonate solution. Then wash it three times with an equal weight of water. Dehydrate and dry under reduced pressure, filter accurately, and obtain the finished product tetra(dimethylpropylsilyl)siloxane. The product has a boiling point of 135°C, a flash point of 140°C, a viscosity of 3.3 centistokes, and a freezing point of -82°C at a pressure of 5 mm mercury.

[0028] Example 4 The structural formula of dimethyl trifluoropropyl silicic acid ester is: Wherein, R is trifluoropropyl.

[0029] 100 kg of dimethyl trifluoropropyl silicic acid was added to a stainless steel reactor, and 15 kg of ethyl orthosilicate and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 24 hours, and the byproduct ethyl acetate was slowly evaporated. The ethoxy group of ethyl orthosilicate was completely replaced by dimethyl trifluoropropyl silyl. Excess dimethyl trifluoropropyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0030] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetrakis(dimethyltrifluoropropylsilyl)siloxane. The product has a boiling point of 142°C, a flash point of 162°C, a viscosity of 5.2 centistokes and a freezing point of -82°C at a pressure of 5 mm mercury.

[0031] Example 5 The structural formula of dimethyl perfluoroethyl silane acetate is: Wherein, R is a perfluoroethyl group.

[0032] 200 kg of dimethyl perfluoroethyl silicic acid was added to a stainless steel reactor, and 15 kg of ethyl orthosilicate and 0.4 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 48 hours, and the byproduct ethyl acetate was slowly evaporated. The ethoxy group of ethyl orthosilicate was completely replaced by dimethyl perfluoroethylsilyl. Excess dimethyl perfluoroethyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0033] The crude product was washed three times with water of equal weight, and the upper oil was collected and washed once with sodium carbonate solution of equal weight and mass concentration of 0.1%. Then it was washed three times with water of equal weight. Dehydrated and dried under reduced pressure, and finely filtered to obtain the finished product tetrakis(dimethylperfluoroalkylethylsilane)siloxane. Nonlinear pentasiloxane with perfluoroalkylethyl side chains was obtained. The product had a boiling point of 180°C, a flash point of 250°C, a viscosity of 6 centistokes, and a freezing point of -30°C at a pressure of 5 mm mercury.

[0034] Example 6 The structural formula of dimethylphenyl silane acetate is: Wherein, R is phenyl.

[0035] 100 kg of dimethylphenyl silicic acid acetate was added to a stainless steel reactor, and 15 kg of ethyl orthosilicate and 0.4 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 18 hours, and the byproduct ethyl acetate was slowly evaporated. The ethoxy group of methyl orthosilicate was completely replaced by dimethylphenylsilyl oxygen. Excess dimethylphenyl silicic acid acetate and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0036] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetrakis(dimethylphenylsilyl)siloxane. The product has a boiling point of 175℃, a flash point of 176℃, a viscosity of 11.5 centistokes and a freezing point of -40℃ under 5mm mercury pressure.

[0037] Example 7 The structural formula of dimethylphenethyl silicic acid ester is: Wherein, R is phenethyl.

[0038] 100 kg of dimethylphenethyl silicic acid was added to a stainless steel reactor, and 15 kg of ethyl orthosilicate and 0.1 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 100°C for 12 hours, and the byproduct ethyl acetate was slowly evaporated. The ethoxy group of methyl orthosilicate was completely replaced by dimethylphenethyl silyl oxygen. Excess dimethylphenethyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0039] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetra(dimethylphenylethylsilyl)siloxane. The product has a boiling point of 182°C at 5 mm mercury pressure, a flash point of 182°C, a viscosity of 16.5 centistokes, and a freezing point of -30°C.

[0040] Example 8 The structural formula of dimethyl perfluorooxamidopropyl silicic acid ester is: Wherein, R is a perfluorooxapropyl group.

[0041] 200 kg of dimethyl perfluorooxypropyl silicic acid was added to a stainless steel reactor, and 15 kg of ethyl orthosilicate and 0.1 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 150°C for 12 hours, and the byproduct ethyl acetate was slowly evaporated. The methoxy group of methyl orthosilicate was completely replaced by dimethyl perfluorooxypropyl siloxy. Excess dimethyl perfluorooxypropyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0042] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetrakis(dimethylperfluorooxypropylsilyl)siloxane. Nonlinear pentasiloxane with fluoroether side chains is obtained. The product has a boiling point of 152°C at 5 mm mercury pressure, no flash point, a viscosity of 11.5 centistokes, and a freezing point of -80°C.

[0043] Example 9 The structural formula of dimethylbutyl silicic acid ester is: Wherein, R is a butyl group.

[0044] 120 kg of dimethylbutyl silicic acid was added to a stainless steel reactor, and 15 kg of methyl orthosilicate and 0.4 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 24 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of methyl orthosilicate was completely replaced by dimethylbutyl siloxy. Excess dimethylbutyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0045] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetra(dimethylbutylsilyl)siloxane. Nonlinear pentasiloxane with butyl side chains is obtained. The product has a boiling point of 155°C, a flash point of 182°C, a viscosity of 10.5 centistokes and a freezing point of -75°C at a pressure of 5 mm mercury.

[0046] Example 10 The structural formula of dimethyl isopropyl silicic acid ester is: Wherein, R is isopropyl.

[0047] 120 kg of dimethyl isopropyl silicic acid was added to a stainless steel reactor, and 15 kg of methyl orthosilicate and 0.4 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 80°C for 18 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of methyl orthosilicate was completely replaced by dimethyl isopropyl siloxy. Excess dimethyl isopropyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0048] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetra(dimethylisopropylsilyl)siloxane. Nonlinear pentasiloxane with isopropyl side chain is obtained. The product has a boiling point of 152°C, a flash point of 176°C, a viscosity of 7.5 centistokes and a freezing point of -80°C at a pressure of 5 mm mercury.

[0049] Embodiment 11 The structural formula of triethyl silicic acid ester is: Wherein, R is ethyl.

[0050] 120 kg of triethyl silicic acid was added to a stainless steel reactor, followed by 15 kg of methyl orthosilicate and 0.4 kg of trifluoromethanesulfonic acid. The reaction was carried out at 80°C for 18 hours, and the byproduct methyl acetate was slowly evaporated. The methoxyl group of methyl orthosilicate was completely replaced by triethylsiloxy. Excess triethyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0051] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetra(triethylsilyl)siloxane. The product has a boiling point of 162°C, a flash point of 178°C, a viscosity of 6.5 centistokes and a freezing point of -85°C at a pressure of 5 mm mercury.

[0052] Example 12 The structural formula of triisopropyl silicic acid ester is: Wherein, R is isopropyl.

[0053] 120 kg of triisopropyl silicic acid acetate was added to a stainless steel reactor, and 15 kg of methyl orthosilicate and 0.4 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 80°C for 24 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of methyl orthosilicate was completely replaced by triisopropyl siloxy. Excess triisopropyl silicic acid acetate and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0054] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetra(triisopropylsilyl)siloxane. The product has a boiling point of 195℃, a flash point of 262℃, a viscosity of 11.5 centistokes and a freezing point of -78℃ under 5mm mercury pressure.

[0055] Embodiment 13 The structural formula of methyl diphenyl silane acetate is: Wherein, R is phenyl.

[0056] 150 kg of methyl diphenyl silicic acid was added to a stainless steel reactor, and 15 kg of methyl orthosilicate and 0.4 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 80°C for 48 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of methyl orthosilicate was completely replaced by methyl diphenyl siloxy. Excess methyl diphenyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0057] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tetra(methyldiphenylsilane)siloxane. The product has a boiling point of 225℃, a flash point of 302℃, a viscosity of 31.5 centistokes and a freezing point of -30℃ under 5mm mercury pressure.

[0058] Embodiment 14 The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0059] 100 kg of dimethylethyl silicic acid was added to a stainless steel reactor, and 15 kg of methyltrimethoxysilane and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 80°C for 12 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of methyltrimethoxysilane was completely replaced by dimethylethylsiloxy. Excess dimethylethyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0060] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product methyl tri (dimethylethyl silicon) siloxane. The product has a boiling point of 132°C, a flash point of 122°C, a viscosity of 4.5 centistokes and a freezing point of -82°C at a pressure of 5 mm mercury.

[0061] Embodiment 15 The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0062] 100 kg of dimethylethyl silicic acid was added to a stainless steel reactor, and 15 kg of phenyltrimethoxysilane and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 80°C for 12 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of phenyltrimethoxysilane was completely replaced by dimethylethylsiloxy. Excess dimethylethyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0063] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product phenyl tris (dimethylethylsilane). The product has a boiling point of 142°C at 5 mm mercury pressure, a flash point of 129°C, a viscosity of 5.5 centistokes, and a freezing point of -80°C.

[0064] Example 16 The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0065] 100 kg of dimethylethyl silicic acid was added to a stainless steel reactor, and 15 kg of isopropyl trimethoxysilane and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 80°C for 12 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of phenyl trimethoxysilane was completely replaced by dimethylethyl siloxy. Excess dimethylethyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0066] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product isopropyl tri(dimethylethylsilyl)siloxane. The product has a boiling point of 137°C at 5 mm mercury pressure, a flash point of 125°C, a viscosity of 4.8 centistokes, and a freezing point of -82°C.

[0067] Embodiment 17 The structural formula of dimethyl perfluorooxamidopropyl silicic acid ester is: Wherein, R is a perfluorooxapropyl group.

[0068] 200 kg of dimethyl perfluorooxypropyl silyl acetate was added to a stainless steel reactor, and 15 kg of methyl trimethoxysilane and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 70°C for 12 hours and at 150°C for 12 hours. The byproduct methyl acetate was slowly evaporated, and the methoxy group of methyl trimethoxysilane was completely replaced by dimethyl perfluorooxypropyl silyloxy. Excess dimethyl perfluorooxypropyl silyl acetate and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0069] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product methyl tris (dimethyl dimethyl perfluorooxypropylsilicon) siloxane. The product has a boiling point of 142°C at 5 mm mercury pressure, no flash point, a viscosity of 9.5 centistokes, and a freezing point of -80°C.

[0070] Embodiment 18 The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0071] 100 kg of dimethylethyl silicic acid was added to a stainless steel reactor, and 15 kg of dimethyltetramethoxydisiloxane and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 90°C for 12 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of dimethyltetramethoxydisiloxane was completely replaced by dimethylethylsiloxy. Excess dimethylethyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0072] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product dimethyltetra(dimethylethylsilyl)disiloxane. The product has a boiling point of 112°C, a flash point of 123°C, a viscosity of 3.9 centistokes and a freezing point of -72°C at a pressure of 5 mm mercury.

[0073] Embodiment 19 The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0074] 100 kg of dimethylethyl silicic acid was added to a stainless steel reactor, and 15 kg of hexamethoxydisiloxane and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 48 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of hexamethoxydisiloxane was completely replaced by dimethylethylsiloxy. Excess dimethylethyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0075] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product hexa(dimethylethylsilyl)disiloxane. The product has a boiling point of 162°C, a flash point of 173°C, a viscosity of 9.2 centistokes and a freezing point of -72°C at a pressure of 5 mm mercury.

[0076] Embodiment 20 The structural formula of dimethyl trifluoropropyl silicic acid ester is: Wherein, R is trifluoropropyl.

[0077] 100 kg of dimethyl trifluoropropyl silicic acid was added to a stainless steel reactor, and 15 kg of hexamethoxydisiloxane and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 24 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of hexamethoxydisiloxane was completely replaced by dimethyl trifluoropropyl siloxy. Excess dimethyl trifluoropropyl silicic acid and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0078] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product hexa(dimethyltrifluoropropylsilyl)disiloxane. The product has a boiling point of 152°C at 5 mm mercury pressure, a flash point of 252°C, a viscosity of 12.5 centistokes, and a freezing point of -75°C.

[0079] Embodiment 21 The structural formula of dimethyl trifluoropropyl silicic acid ester is: Wherein, R is trifluoropropyl.

[0080] 50 kg of dimethyl trifluoropropyl silicic acid ester and 50 kg of dimethyl ethyl silicic acid ester were added to a stainless steel reactor, and 15 kg of hexamethoxy disiloxane and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 100°C for 24 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of hexamethoxy disiloxane was completely replaced by dimethyl trifluoropropyl silicyloxy group and dimethyl ethyl silicyloxy group. Excess dimethyl trifluoropropyl silicic acid ester, dimethyl ethyl silicic acid ester and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0081] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product tris(dimethylethylsilyl)tris(dimethyltrifluoropropylsilyl)disiloxane. The product has a boiling point of 142℃ and a flash point of 155℃ under 5mm mercury pressure, a viscosity of 9.5 centistokes, and a freezing point of -80℃.

[0082] Embodiment 21 The structural formula of dimethyl trifluoropropyl silicic acid ester is: Wherein, R is trifluoropropyl.

[0083] The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0084] 80 kg of dimethyl trifluoropropyl silicic acid ester and 20 kg of dimethyl ethyl silicic acid ester were added to a stainless steel reactor, and 15 kg of methyl trimethoxysilane and 0.2 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 60°C for 24 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of methyl trimethoxysiloxane was completely replaced by dimethyl trifluoropropyl siloxy and dimethyl ethyl siloxy. Excess dimethyl trifluoropropyl silicic acid ester, dimethyl ethyl silicic acid ester and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0085] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product. The product has a boiling point of 162°C at 5 mm mercury pressure, a flash point of 173°C, a viscosity of 9.2 centistokes, and a freezing point of -72°C.

[0086] Embodiment 22 The structural formula of dimethyl trifluoropropyl silicic acid ester is: Wherein, R is trifluoropropyl.

[0087] The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0088] 80 kg of dimethyl trifluoropropyl silicic acid ester and 20 kg of dimethyl ethyl silicic acid ester were added to a stainless steel reactor, and 15 kg of diphenyl tetramethoxysilane and 1 kg of trifluoromethanesulfonic acid were added. The reaction was carried out at 40°C for 24 hours, and the by-product methyl acetate was slowly evaporated under reduced pressure. The methoxy group of diphenyl tetramethoxysilane was completely replaced by dimethyl trifluoropropyl silicic acid group and dimethyl ethyl silicic acid group. Excess dimethyl trifluoropropyl silicic acid ester, dimethyl ethyl silicic acid ester and trifluoromethanesulfonic acid were removed under reduced pressure to obtain a crude product.

[0089] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product. The product has a boiling point of 158°C at 5 mm mercury pressure, a flash point of 182°C, a viscosity of 8.7 centistokes, and a freezing point of -82°C.

[0090] Embodiment 23 The structural formula of dimethyl trifluoropropyl silicic acid ester is: Wherein, R is trifluoropropyl.

[0091] The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0092] 80 kg of dimethyl trifluoropropyl silicic acid ester and 20 kg of dimethyl ethyl silicic acid ester were added to a stainless steel reactor, and 15 kg of diphenyl tetramethoxysilane and 0.2 kg of perfluorosulfonic acid hydrogen resin were added. The reaction was carried out at 90°C for 24 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of diphenyl tetramethoxysilane was completely replaced by dimethyl trifluoropropyl siloxy and dimethyl ethyl siloxy. The resin was filtered, and the excess dimethyl trifluoropropyl silicic acid ester and dimethyl ethyl silicic acid ester were removed by decompression of the clear liquid to obtain a crude product.

[0093] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product. The product has a boiling point of 158°C at 5 mm mercury pressure, a flash point of 182°C, a viscosity of 8.7 centistokes, and a freezing point of -82°C.

[0094] Embodiment 24 The structural formula of dimethyl trifluoropropyl silicic acid ester is: Wherein, R is trifluoropropyl.

[0095] The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0096] 80 kg of dimethyl trifluoropropyl silicic acid ester and 20 kg of dimethyl ethyl silicic acid ester were added to a stainless steel reactor, and 15 kg of diphenyl tetramethoxysilane and 0.2 kg of di(trifluoromethanesulfonyl)amide were added. The reaction was carried out at 70°C for 12 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of diphenyl tetramethoxysilane was completely replaced by dimethyl trifluoropropyl silicic acid group and dimethyl ethyl silicic acid group. The resin was filtered, and the clear liquid was decompressed to remove the excess dimethyl trifluoropropyl silicic acid ester, dimethyl ethyl silicic acid ester and trifluoromethanesulfonic acid to obtain a crude product.

[0097] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product. The product has a boiling point of 158°C at 5 mm mercury pressure, a flash point of 182°C, a viscosity of 8.7 centistokes, and a freezing point of -82°C.

[0098] Embodiment 25 The structural formula of dimethyl trifluoropropyl silicic acid ester is: Wherein, R is trifluoropropyl.

[0099] The structural formula of dimethyl ethyl silicic acid ester is: Wherein, R is ethyl.

[0100] 80 kg of dimethyl perfluorooxapropyl silicic acid ester and 60 kg of dimethyl ethyl silicic acid ester were added to a stainless steel reactor, and 15 kg of diphenyltetramethoxysilane and 0.2 kg of di(trifluoromethanesulfonyl)amide were added. The reaction was carried out at 80°C for 8 hours, and the byproduct methyl acetate was slowly evaporated. The methoxy group of diphenyltetramethoxysilane was completely replaced by dimethyltrifluoropropylsilyloxy and dimethylethylsilyloxy. The resin was filtered, and the clear liquid was decompressed to remove the excess dimethyltrifluoropropyl silicic acid ester, dimethylethyl silicic acid ester and trifluoromethanesulfonic acid to obtain a crude product.

[0101] Wash the crude product three times with equal weight of water, collect the upper oil and wash it once with equal weight and mass concentration of 0.1% sodium carbonate solution. Then wash it three times with equal weight of water. Dehydrate and dry under reduced pressure, filter accurately to obtain the finished product. The product has a boiling point of 158°C at 5 mm mercury pressure, a flash point of 182°C, a viscosity of 8.7 centistokes, and a freezing point of -82°C.

[0102] Table 1 The above are only preferred 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 specification of the present invention, 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 poly(trialkylsilyl)-substituted siloxane, characterized in that: The structural formula of the poly(trialkylsilyl)-substituted siloxane is: Among them, R1, R2, R3, R4, R5, R6, R7 and R8 may be the same as or different from each other, and are each independently phenyl, benzyl, phenethyl, nitrile ethyl, nitrile, methoxyethyl, ethoxyethyl, an alkyl group having 1 to 16 carbon atoms, or a partially fluorinated alkyl group having 1 to 16 carbon atoms.

2. The poly(trialkylsilyl)-substituted siloxane according to claim 1, characterized in that: The carbon number of the alkyl group is 1 to 8; the carbon number of the partially fluorinated alkyl group is 1 to 8.

3. A method for preparing the poly(trialkylsilyl)-substituted siloxane according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: using trialkyl silyl acetate and alkoxy silane to carry out ester exchange reaction under the action of a catalyst to obtain poly (trialkyl silicon) substituted siloxane.

4. The preparation method according to claim 3, characterized in that: The alkoxysilane includes alkyltrialkoxysilane, tetraalkoxysilane, dialkyltetraalkoxydisiloxane, hexaalkoxydisiloxane, trialkylhexaalkoxytrisiloxane or octaalkoxytrisiloxane.

5. The preparation method according to claim 3, characterized in that: The structural formula of the trialkyl silyl acetate is: Wherein, R is phenyl, benzyl, phenethyl, nitrileethyl, nitrile, methoxyethyl, ethoxyethyl, alkyl having 1 to 16 carbon atoms or partially fluorinated alkyl having 1 to 16 carbon atoms.

6. The preparation method according to claim 3, characterized in that: The mass ratio of the trialkyl silane acetate to the alkoxysilane is 1-15:1; and the added amount of the catalyst is 0.1-10% relative to the mass of the trialkyl silane acetate.

7. The preparation method according to any one of claims 3 to 6, characterized in that: The catalyst includes one or more of sulfuric acid, trifluoromethanesulfonic acid, perfluoroalkylsulfonic acid, perfluoro hydrogen sulfonic acid resin, bis(trifluoromethylsulfonyl)amide and hydrogen sulfonic acid resin.

8. The preparation method according to any one of claims 3 to 6, characterized in that: The temperature of the transesterification reaction is 40 to 200° C., and the time is 10 to 50 hours.

9. The preparation method according to any one of claims 3 to 6, characterized in that: After the ester exchange reaction is completed, the finished product is obtained through processes such as catalyst separation, water washing, alkali washing, water washing, drying, and filtering.

10. Use of the poly(trialkylsilicon)-substituted siloxane according to any one of claims 1 to 2 or the poly(trialkylsilicon)-substituted siloxane prepared by the preparation method according to any one of claims 3 to 9 in immersion cooling liquid.

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