Organic silicon cooling liquid and preparation method thereof

Abstract

The invention provides organic silicon cooling liquid and a preparation method thereof. The molecular structural formula of the organic silicon cooling liquid is shown in the specification, R1 is selected from C3-7alkane, the value of a is 0-12, and the value of b is 14-20. A phenyl group and a long-chain alkyl side chain are introduced into a silicone oil main chain through an organic synthesis means, the regularity of a polysiloxane chain is destroyed, the crystallization property of the polysiloxane chain is reduced, the performance of the organic silicon cooling liquid is changed from the molecular structure, and the organic silicon cooling liquid can still flow at a low temperature (-65 DEG C). In addition, by introducing phenyl, the flash point, irradiation resistance and other properties of the immersed cooling liquid can be remarkably improved. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and more specifically to an organic silicon coolant and a preparation method thereof. Background Art

[0002] With the rapid development of artificial intelligence (AI) technology, the demand for intelligent computing power continues to rise, and the heat generation and heat flux density of chips also increase accordingly. When the chip is in a high-temperature operating state for a long time, its performance and service life will be affected, and the failure rate will also increase. Liquid cooling uses a liquid with a high specific heat capacity as a transmission medium to remove heat. It is a new method that has emerged in recent years due to the increase in the demand for heat dissipation in data centers - immersion liquid cooling technology. The core key material of this technology is immersion coolant. Currently, the most important coolant used in data centers on the market is fluorinated material, which has a low pour point and can be used in relatively cold application scenarios, such as 3M TM The lowest pour point of the Novec series can reach -135°C, but electronic fluorinated liquids have environmental regulatory risks. In order to reduce the negative impact of PFAS on the company, 3M has decided to withdraw from all PFAS production by the end of 2025. Although there are currently no relevant environmental regulations in China, it has become a potential uncertainty in the future.

[0003] Compared with fluorinated liquid, silicone coolant has more balanced performance in all aspects, has higher "plasticity", especially safety and environmental protection, and its penetration rate in the liquid cooling market is expected to gradually increase. However, the pour point of dimethyl silicone oil is as low as -50℃, which is far lower than that of electronic fluorinated liquid, limiting its application scenarios. For example, the DOWSIL TM ICL-1000 silicone coolant becomes turbid below 25°C.

[0004] Therefore, there is a need to provide a silicone coolant with a lower pour point. Summary of the invention

[0005] The purpose of the present invention is to address the problem of high pour point of single-phase immersion silicone coolant so that it can be used in relatively cold application scenarios. By introducing phenyl groups into the main chain of silicone oil and long-chain alkyl side chains through organic synthesis, the performance of the silicone coolant is changed from the molecular structure, so that it can still flow at a relatively low temperature (-65°C).

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] The present invention provides an organosilicon coolant, the molecular structure of the organosilicon coolant is as follows:

[0008]

[0009] Among them, R1 is selected from C 3～7 alkane, the value of a ranges from 0 to 12, and the value of b ranges from 14 to 20.

[0010] As an embodiment of the present invention, the values of a and b satisfy: a / b = 0 to 0.6.

[0011] As an embodiment of the present invention, R1 is selected from —C3H8, —C5H 12 or —C7H 16 .

[0012] In the second aspect of the present invention, there is provided a preparation method of the organosilicon coolant described in the first aspect of the present invention, including the following steps:

[0013] S1: α-olefin, tetramethyldisiloxane, and catalyst A are uniformly mixed in a solvent to obtain a reaction solution, and a grafting reaction is carried out to obtain modified tetramethyldisiloxane;

[0014] S2: Bis(trimethylsilyl)benzene, methylvinylsiloxane cyclic oligomers, and dimethylsiloxane cyclic oligomers are uniformly mixed, and then catalyst B is added, and a ring-opening copolymerization reaction is carried out to obtain phenylvinyl silicone oil;

[0015] S3: The modified tetramethyldisiloxane obtained in step S1, the phenylvinyl silicone oil obtained in step S2, and catalyst C are uniformly mixed in a solvent to obtain a reaction solution, and a grafting reaction is carried out to obtain the organosilicon coolant.

[0016] As an embodiment of the present invention, in step S1, the molar ratio of the α-olefin to the tetramethyldisiloxane is 1:1.

[0017] As an embodiment of the present invention, in step S1, the concentration of the α-olefin in the reaction solution is 0.1 to 2 g / mL.

[0018] As an embodiment of the present invention, in step S1, the mass of catalyst A is 5 to 10 ppm of the total mass of the α-olefin and the tetramethyldisiloxane.

[0019] As an embodiment of the present invention, in step S2, the mass of catalyst B is 0.5 to 5% of the total mass of bis(trimethylsilyl)benzene, methylvinylsiloxane cyclic oligomers, and dimethylsiloxane cyclic oligomers.

[0020] As an embodiment of the present invention, in step S3, the molar ratio of the modified tetramethyldisiloxane to the phenylvinyl silicone oil is (1.2 to 1.5):1.

[0021] As an embodiment of the present invention, in step S3, the concentration of the modified tetramethyldisiloxane in the reaction solution is 0.1 to 2 g / mL.

[0022] As an embodiment of the present invention, in step S3, the mass of the catalyst C is 20-50 ppm of the total mass of the modified tetramethyldisiloxane and phenyl vinyl silicone oil.

[0023] As an embodiment of the present invention, the solvents in steps S1 and S3 independently include at least one of petroleum ether, n-hexane, ethyl acetate, and toluene.

[0024] As an embodiment of the present invention, the catalyst A includes at least one of Karstedt catalyst and chloroplatinic acid catalyst.

[0025] As an embodiment of the present invention, the catalyst B includes at least one of concentrated sulfuric acid, trifluoromethanesulfonic acid, C 16～20 fatty acid, sulfamic acid, metal oxide, and antimony pentafluoride.

[0026] As an embodiment of the present invention, the catalyst C includes at least one of Karstedt catalyst and chloroplatinic acid catalyst.

[0027] As an embodiment of the present invention, the temperature of the reaction in step S1 is 50-120 °C, and the reaction time is 10-14 h.

[0028] As an embodiment of the present invention, the temperature of the reaction in step S2 is 50-90 °C, and the reaction time is 2-8 h.

[0029] As an embodiment of the present invention, the temperature of the reaction in step S3 is 50-120 °C, and the reaction time is 10-14 h.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] The present invention introduces phenyl groups into the silicone oil main chain and long-chain alkyl side chains through organic synthesis means, destroys the regularity of the polysiloxane chain, reduces its crystallization performance, changes the performance of the silicone coolant from the molecular structure, and can still flow at a relatively low temperature (-65 °C). In addition, by introducing phenyl groups, the flash point, radiation resistance and other properties of the immersion coolant can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the synthesis of the silicone coolant of Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] To better illustrate the objectives, technical solutions, and advantages of the present invention, the following will further illustrate the present invention in conjunction with specific embodiments. However, the embodiments do not impose any form of limitation on the present invention. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field. Unless otherwise specified, the reagents and materials used in the present invention are all commercially available.

[0034] In the present invention, among the technically characterized described in an open-ended manner, it includes a closed technical solution composed of the listed features, as well as an open technical solution including the listed features.

[0035] In the present invention, regarding the numerical range, unless otherwise specified, the above numerical range is considered continuous, and includes the minimum and maximum values of the range, as well as each value between such minimum and maximum values. Further, when the range refers to an integer, it includes each integer between the minimum and maximum values of the range. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0036] For the reagents or instruments used in the present invention that are not indicated by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0037] In the first aspect of the present invention, an embodiment provides a silicone coolant, and the molecular structural formula of the silicone coolant is as follows:

[0038]

[0039] Among them, R1 is selected from C 3～7 alkane, the value of a is 0 to 12, and the value of b is 14 to 20.

[0040] The pour point of dimethyl silicone oil is at least about -50°C, far inferior to that of electronic fluorinated liquid, which limits its application scenarios. The present invention introduces phenyl groups into the silicone main chain through organic synthesis means to change the performance of the silicone coolant from the molecular structure, and it can still flow at a lower temperature (-65°C). After introducing phenyl groups on the silicone main chain, the volume of phenyl groups is relatively large, which will increase the rigidity of the molecular chain, reduce the flexibility of the molecular chain, weaken the movement ability of the molecular chain, and thus affect its fluidity; at the same time, the introduction of phenyl groups will also change the intermolecular force, increase the van der Waals force between molecules, making the molecular chain more difficult to move; the volume and shape of phenyl groups will affect the arrangement and crystallinity of the molecular chain, and the introduction of phenyl groups will reduce the crystallinity of silicone, making it more difficult to crystallize, thereby reducing the pour point. C 3～7Alkanes with a certain length are flexible. Their introduction increases the flexibility of the molecular chain, further enhances the intermolecular force, and improves the fluidity of the silicone coolant. At the same time, it disrupts the overall regularity of the molecular chain, reduces the crystallinity of the silicone, and lowers the pour point.

[0041] In addition, using dimethylsiloxane to graft long-chain alkanes onto the side groups of the siloxane chain segments can ensure the movement sensitivity of the branched alkanes. At the same time, under the interaction of steric hindrance between the methyl groups, methylene groups on the side chains and the phenyl groups on the main chain, a specific spatial configuration is formed, which can form a certain spatial heat conduction network structure within the molecule, improve the thermal conductivity of the silicone coolant molecules, further enhance the heat dissipation performance, and ensure the high fluidity of the silicone coolant.

[0042] In some embodiments of the present invention, the values of a and b satisfy: a / b = 0 - 0.6. The smaller the value of a / b, the more the proportion of branched alkyl groups in the molecular chain of the silicone coolant, and the richer the formed spatial heat conduction network. However, when there are too many branched alkyl groups, the large branched chain system will also affect the mobility and crystallinity of the silicon-oxygen main chain of the silicone coolant, thereby affecting the thermal conductivity uniformity of the silicone coolant. Therefore, when the value of a / b is within the above appropriate range, the compatibility, fluidity at high and low temperatures, and thermal conductivity effect of the silicone coolant can be significantly improved. The value of a / b can specifically be any one of 0, 0.35, 0.5, 0.6 or the range formed by any two numerical values.

[0043] In some embodiments of the present invention, R1 is selected from —C3H8, —C5H 12 or —C7H 16 . When the number of carbon atoms of the long branched-chain alkane is within a suitable range, the steric hindrance between the phenyl group and the silicon atom can better protect the branched chain, and it will not be entangled due to the too long molecular chain, affecting the fluidity and resulting in uneven heat dissipation.

[0044] In the second aspect of the present invention, a preparation method of the silicone coolant described in the first aspect of the present invention is provided, including the following steps:

[0045] S1: α-olefin, tetramethyldisiloxane, and catalyst A are mixed evenly in a solvent to obtain a reaction solution, and a grafting reaction is carried out to obtain modified tetramethyldisiloxane;

[0046] S2: Bis(terminal phenyl)dimethylsiloxane, methyl vinyl siloxane cyclic oligomer, and dimethyl siloxane cyclic oligomer are mixed evenly, and then catalyst B is added, and a ring-opening copolymerization reaction is carried out to obtain phenyl vinyl silicone oil;

[0047] S3: Mix the modified tetramethyldisiloxane obtained in step S1, the phenylvinyl silicone oil obtained in step S2, and catalyst C evenly in a solvent to obtain a reaction solution, and carry out a graft reaction to obtain the silicone coolant.

[0048] In some embodiments of the present invention, the bis(3,3,3-trifluoropropyl)dimethylsiloxane includes diphenyltetramethyldisiloxane.

[0049] In some embodiments of the present invention, the methylvinylsiloxane cyclic bodies include at least one of tetravinyltetramethylcyclotetrasiloxane, octavinyl octamethylcyclooctasiloxane, and decavinyl decamethylcyclodecasiloxane.

[0050] In some embodiments of the present invention, the dimethylsiloxane cyclic bodies include at least one of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, and hexadecamethylcyclooctasiloxane.

[0051] It should be noted that by regulating the types and molar ratios of the methylvinylsiloxane cyclic bodies and the dimethylsiloxane cyclic bodies, the molecular chain structure of the silicone coolant can be regulated. The dosages of the bis(3,3,3-trifluoropropyl)dimethylsiloxane, the methylvinylsiloxane cyclic bodies, and the dimethylsiloxane cyclic bodies can be adjusted according to theoretical requirements.

[0052] In some embodiments of the present invention, in step S1, the molar ratio of the α-olefin to the tetramethyldisiloxane is 1:1.

[0053] In some embodiments of the present invention, in step S1, the concentration of the α-olefin in the reaction solution is 0.1 - 2 g / mL.

[0054] In some embodiments of the present invention, in step S1, the mass of catalyst A is 5 - 10 ppm of the total mass of the α-olefin and the tetramethyldisiloxane.

[0055] In some embodiments of the present invention, in step S2, the mass of catalyst B is 0.5 - 5% of the total mass of "bis(3,3,3-trifluoropropyl)dimethylsiloxane + methylvinylsiloxane cyclic bodies + dimethylsiloxane cyclic bodies".

[0056] In some embodiments of the present invention, in step S3, the molar ratio of the modified tetramethyldisiloxane to the phenylvinyl silicone oil is (1.2 - 1.5):1.

[0057] In some embodiments of the present invention, in step S3, the concentration of the modified tetramethyldisiloxane in the reaction solution is 0.1 - 2 g / mL. Keeping the raw material in this concentration range in the reaction system is beneficial to the rapid synthesis of the target product.

[0058] In some embodiments of the present invention, in step S3, the mass of the catalyst C is 20-50 ppm of the total mass of the modified tetramethyldisiloxane and phenyl vinyl silicone oil.

[0059] In some embodiments of the present invention, the solvents described in steps S1 and S3 independently include at least one of petroleum ether, n-hexane, ethyl acetate, and toluene. The types of solvents in steps S1 and S2 may be the same or different, as long as they can dissolve the raw materials in the corresponding reaction systems.

[0060] In some embodiments of the present invention, the catalyst A described in step S1 includes at least one of Karstedt catalyst and chloroplatinic acid catalyst.

[0061] In some embodiments of the present invention, the catalyst B described in step S2 includes at least one of concentrated sulfuric acid, trifluoromethanesulfonic acid, C 16～20 fatty acid, sulfamic acid, metal oxide, and antimony pentafluoride.

[0062] In some embodiments of the present invention, the catalyst C described in step S3 includes at least one of Karstedt catalyst and chloroplatinic acid catalyst.

[0063] It should be noted that in the embodiments of the present application, the corresponding catalyst A and catalyst C in steps S1 and S3 may be the same or different, as long as they can accelerate the reaction rate and ensure that the reaction can proceed.

[0064] In some embodiments of the present invention, the temperature of the reaction in step S1 is 50-120 °C, and the reaction time is 10-14 h.

[0065] In some embodiments of the present invention, the temperature of the reaction in step S2 is 50-90 °C, and the reaction time is 2-8 h.

[0066] In some embodiments of the present invention, the temperature of the reaction in step S3 is 50-120 °C, and the reaction time is 10-14 h.

[0067] The following are specific embodiments of the present invention.

[0068] Example 1

[0069] This example provides an organosilicon coolant, which is prepared by a method comprising the following steps:

[0070] S1: Dissolve 1 mol of hexene (84 g) and 545 μL (2.725 mg) of Karstedt catalyst in 50 mL of n - hexane, transfer it to a flask, add 1 mol of tetramethyldisiloxane (134.32 g) at a stirring speed of 300 r / min, heat up to 70 °C and react for 12 h. After the reaction is completed, filter, and carry out vacuum distillation on the filtrate to remove the solvent, then the modified tetramethyldisiloxane can be obtained;

[0071] S2: Mix 0.1 mol of diphenyltetramethyldisiloxane (28.65 g) and 0.5 mol of tetravinyltetramethylcyclotetrasiloxane (172.33 g) evenly and add them to a flask, add 10 g of concentrated sulfuric acid, heat up to 80 °C and react for 6 h. After the reaction is completed, filter, and the product is in the filtrate. Further carry out vacuum distillation on the filtrate product to remove the solvent, then the phenylvinyl silicone oil can be obtained;

[0072] S3: Take 0.1 mol of the phenylvinyl silicone oil in step S2 and 1.81 mL (9.05 mg) of Karstedt catalyst, mix them evenly in 50 mL of n - hexane, and transfer them to a flask. Then add 2.5 mol of the modified tetramethyldisiloxane in step S1, heat up to 70 °C and react for 12 h to obtain the silicone coolant. The chemical reaction route of the silicone coolant is as Figure 1 shown, and the structural formula is as shown in Formula I. In Formula I, R1 is —C3H8, a = 0, b = 20.

[0073]

[0074] Example 2

[0075] This example provides a silicone coolant, and the preparation method includes the following steps:

[0076] S1: Mix 1 mol of octene, 50 mL of n - hexane and 585 μL of Karstedt catalyst and add them to a flask, add 1 mol of tetramethyldisiloxane at a stirring speed of 300 r / min for reaction, heat up to 70 °C and react for 12 h. After the reaction is completed, filter, and carry out vacuum distillation on the filtrate to remove the solvent;

[0077] S2. Mix 0.1 mol of diphenyltetramethyldisiloxane and 0.5 mol of tetravinyltetramethylcyclotetrasiloxane evenly and add them to a flask, add 10 g of concentrated sulfuric acid, heat up to 80 °C and react for 6 h; after the reaction is completed, filter and carry out vacuum distillation;

[0078] S3. Mix 0.1 mol of the phenylvinyl silicone oil obtained in step S2 above, 50 mL of n-hexane, and 1.96 mL of Karstedt catalyst evenly and add them to a flask. Then add 2.5 mol of the octyltetramethyldisiloxane obtained in step S1 and carry out the reaction. Heat up to 70 °C and react for 12 h to obtain the silicone coolant. The structural formula is as shown in Formula I. In Formula I, R1 is —C5H 10 , a = 0, b = 20.

[0079] Example 3

[0080] This example provides a silicone coolant, and the preparation method includes the following steps:

[0081] S1: Mix 1 mol of decene, 50 mL of n-hexane, and 675 μL of Karstedt catalyst and add them to a flask. Add 1 mol of tetramethyldisiloxane at a stirring speed of 300 r / min and carry out the reaction. Heat up to 70 °C and react for 12 h; after the reaction is completed, filter, and carry out vacuum distillation on the filtrate to remove the solvent;

[0082] S2: Mix 0.1 mol of diphenyltetramethyldisiloxane and 0.5 mol of tetravinyltetramethylcyclotetrasiloxane evenly and add them to a flask. Add 10 g of concentrated sulfuric acid and heat up to 80 °C and react for 6 h; after the reaction is completed, filter and carry out vacuum distillation;

[0083] S3: Mix 0.1 mol of the phenylvinyl silicone oil obtained in step S2 above, 50 mL of n-hexane, and 2.12 mL of Karstedt catalyst evenly and add them to a flask. Add 2.5 mol of the decyltetramethyldisiloxane obtained in step S1, heat up to 70 °C and react for 12 h to obtain the silicone coolant. The structural formula is as shown in Formula I. In Formula I, R1 is —C7H 16 , a = 0, b = 20.

[0084] Example 4

[0085] This example provides a silicone coolant, and the preparation method includes the following steps:

[0086] S1: Mix 1 mol of hexene, 50 mL of n-hexane, and 545 μL of Karstedt catalyst and add them to a flask. Add 1 mol of tetramethyldisiloxane at a stirring speed of 300 r / min and carry out the reaction. Heat up to 70 °C and react for 12 h; after the reaction is completed, filter, and carry out vacuum distillation on the filtrate to remove the solvent;

[0087] S2: Mix 0.1 mol of diphenyltetramethyldisiloxane, 0.425 mol of tetravinyltetramethylcyclotetrasiloxane, and 0.15 mol of octamethylcyclotetrasiloxane evenly and add them to a flask. Then add 10.9 g of concentrated sulfuric acid and heat up to 60 °C for reaction for 8 h. After the reaction is completed, filter and perform vacuum distillation.

[0088] S3: Mix 0.1 mol of the phenylvinyl silicone oil obtained in step S2 above, 50 mL of n-hexane, and 1.86 mL of Karstedt catalyst evenly and add them to a flask. Then add 2.125 mol of the hexyltetramethyldisiloxane obtained in step S1, heat up to 70 °C and react for 12 h to obtain the silicone coolant. The structural formula is as shown in Formula I. In Formula I, R1 is —C3H8, a = 6, and b = 17.

[0089] Example 5

[0090] This example provides a silicone coolant, and the preparation method includes the following steps:

[0091] S1: Mix 1 mol of octene, 50 mL of n-hexane, and 585 μL of Karstedt catalyst and add them to a flask. React by adding 1 mol of tetramethyldisiloxane at a stirring speed of 300 r / min, heat up to 70 °C and react for 12 h. After the reaction is completed, filter and perform vacuum distillation on the filtrate to remove the solvent.

[0092] S2. Mix 0.1 mol of diphenyltetramethyldisiloxane, 0.425 mol of tetravinyltetramethylcyclotetrasiloxane, and 0.15 mol of octamethylcyclotetrasiloxane evenly and add them to a flask. Then add 10.9 g of concentrated sulfuric acid and heat up to 60 °C for reaction for 8 h. After the reaction is completed, filter and perform vacuum distillation.

[0093] S3. Mix 0.1 mol of the phenylvinyl silicone oil obtained in step S2 above, 50 mL of n-hexane, and 2.01 mL of Karstedt catalyst evenly and add them to a flask. Then add 2.125 mol of the octyltetramethyldisiloxane obtained in step S1 and react. Heat up to 70 °C and react for 12 h to obtain the silicone coolant. The structural formula is as shown in Formula I. In Formula I, R1 is —C5H 10 , a = 6, and b = 17.

[0094] Example 6

[0095] This example provides a silicone coolant, and the preparation method includes the following steps:

[0096] S1: Mix 1 mol of decene, 50 mL of n - hexane, and 675 μL of Karstedt catalyst in a flask. Add 1 mol of tetramethyldisiloxane under a stirring speed of 300 r / min for reaction. Heat up to 70 °C and react for 12 h. After the reaction is completed, filter and perform vacuum distillation on the filtrate to remove the solvent.

[0097] S2: Mix 0.1 mol of diphenyltetramethyldisiloxane, 0.425 mol of tetravinyltetramethylcyclotetrasiloxane, and 0.15 mol of octamethylcyclotetrasiloxane evenly in a flask. Add 8.8 g of concentrated sulfuric acid and heat up to 60 °C for reaction for 8 h. After the reaction is completed, filter and perform vacuum distillation.

[0098] S3: Mix 0.1 mol of the phenylvinyl silicone oil obtained in step S2 above, 50 mL of n - hexane, and 2.17 mL of Karstedt catalyst evenly in a flask. Add 2.125 mol of the decyltetramethyldisiloxane obtained in step S1, heat up to 70 °C and react for 12 h to obtain the silicone coolant, and the structural formula is as shown in Formula I. In Formula I, R1 is —C7H 16 , a = 6, b = 17.

[0099] Example 7

[0100] This example provides a silicone coolant, and the preparation method includes the following steps:

[0101] S1: Mix 1 mol of hexene, 50 mL of n - hexane, and 545 μL of Karstedt catalyst in a flask. Add 1 mol of tetramethyldisiloxane under a stirring speed of 300 r / min for reaction. Heat up to 70 °C and react for 12 h. After the reaction is completed, filter and perform vacuum distillation on the filtrate to remove the solvent.

[0102] S2: Mix 0.1 mol of diphenyltetramethyldisiloxane, 0.45 mol of tetravinyltetramethylcyclotetrasiloxane, and 0.15 mol of octamethylcyclotetrasiloxane evenly in a flask. Add 8.8 g of concentrated sulfuric acid and heat up to 80 °C for reaction for 6 h. After the reaction is completed, filter and perform vacuum distillation.

[0103] S3: Mix 0.1 mol of the phenylvinyl silicone oil obtained in step S2 above, 50 mL of n - hexane, and 1.75 mL of Karstedt catalyst evenly in a flask. Add 2.25 mol of the hexyltetramethyldisiloxane obtained in step S1, heat up to 70 °C and react for 12 h to obtain the silicone coolant, and the structural formula is as shown in Formula I. In Formula I, R1 is —C3H8, a = 6, b = 18.

[0104] Examples 8 - 9

[0105] It was prepared according to the method of Example 7. By adjusting the molar ratio of raw materials, reaction temperature and time in step S2, silicone coolants with different values of a and b were obtained. See Table 1 for details.

[0106] Comparative Example 1

[0107] This comparative example provides a silicone coolant. The preparation method includes the following steps:

[0108] S1: 1 mol of hexene, 50 mL of n - hexane, and 545 μL of Karstedt catalyst were mixed and added into a flask. 1 mol of tetramethyldisiloxane was added for reaction under a stirring speed of 300 r / min, and the temperature was raised to 70 °C for reaction for 12 h; after the reaction was completed, filtration was carried out, and the solvent was removed by vacuum distillation of the filtrate;

[0109] S2: 0.1 mol of hexamethyldisiloxane and 0.5 mol of tetravinyltetramethylcyclotetrasiloxane were mixed evenly and added into a flask, 10 g of concentrated sulfuric acid was added, and the temperature was raised to 80 °C for reaction for 6 h; after the reaction was completed, filtration and vacuum distillation were carried out;

[0110] S3: 0.1 mol of the phenylvinyl silicone oil obtained in step S2 above, 50 mL of n - hexane, and 1.81 mL of Karstedt catalyst were mixed evenly and added into a flask, 2.5 mol of the hexyltetramethyldisiloxane obtained in step S1 was added, and the temperature was raised to 70 °C for reaction for 12 h to obtain the silicone coolant. Compared with Example 1 in terms of the structural formula, the difference is that the molecular chain does not contain phenyl.

[0111] Comparative Example 2

[0112] This comparative example provides a silicone coolant. The preparation method includes the following steps:

[0113] S1: 1 mol of hexene, 50 mL of n - hexane, and 545 μL of Karstedt catalyst were mixed and added into a flask. 1 mol of tetramethyldisiloxane was added for reaction under a stirring speed of 300 r / min, and the temperature was raised to 70 °C for reaction for 12 h; after the reaction was completed, filtration was carried out, and the solvent was removed by vacuum distillation of the filtrate;

[0114] S2: 0.1 mol of diphenyltetramethyldisiloxane, 0.4 mol of tetravinyltetramethylcyclotetrasiloxane, and 0.4 mol of octamethylcyclotetrasiloxane were mixed evenly and added into a flask, 14.2 g of concentrated sulfuric acid was added, and the temperature was raised to 80 °C for reaction for 6 h; after the reaction was completed, filtration and vacuum distillation were carried out;

[0115] S3: Mix 0.1 mol of the phenylvinyl silicone oil obtained in step S2 above, 50 mL of n - hexane, and 2.02 mL of Karstedt catalyst uniformly, add them to a flask, add 2.0 mol of the hexyltetramethyldisiloxane obtained in step S1, heat up to 70 °C and react for 12 h to obtain the silicone coolant. The structural formula is as shown in Formula I. In Formula I, R1 is —C3H8, a = 16, and b = 16.

[0116] Comparative Example 3

[0117] This comparative example provides a silicone coolant, and the preparation method includes the following steps:

[0118] S1: Mix 1 mol of hexene, 50 mL of n - hexane, and 545 μL of Karstedt catalyst and add them to a flask. Add 1 mol of tetramethyldisiloxane under a stirring speed of 300 r / min for reaction, heat up to 70 °C and react for 12 h; after the reaction is completed, filter, and perform vacuum distillation on the filtrate to remove the solvent;

[0119] S2: Mix 0.1 mol of diphenyltetramethyldisiloxane and 0.25 mol of tetravinyltetramethylcyclotetrasiloxane uniformly, add them to a flask, add 5.74 g of concentrated sulfuric acid, heat up to 80 °C and react for 6 h; after the reaction is completed, filter and perform vacuum distillation;

[0120] S3: Mix 0.1 mol of the phenylvinyl silicone oil obtained in step S2 above, 50 mL of n - hexane, and 1.67 mL of Karstedt catalyst uniformly, add them to a flask, add 1.25 mol of the hexyltetramethyldisiloxane obtained in step S1, heat up to 70 °C and react for 12 h to obtain the silicone coolant. The structural formula is as shown in Formula I. In Formula I, R1 is —C3H8, a = 0, and b = 10.

[0121] Comparative Example 4

[0122] This comparative example provides a silicone coolant, which is prepared by referring to the preparation method of Example 1. The difference from Example 1 is that in step S3, the modified tetramethyldisiloxane in step S1 is not added. That is, in the molecular chain of the silicone coolant, there is no branched - chain alkane including R1.

[0123] Comparative Example 5

[0124] This comparative example provides a silicone coolant, which is prepared by referring to the preparation method of Example 1. The difference from Example 1 is that in step S1, hexene is replaced by an equimolar amount of α - hexadecene.

[0125] Comparative Example 6

[0126] This comparative example provides a silicone coolant, which is prepared by referring to the preparation method of Example 1. The difference from Example 1 is that in step S2, diphenyltetramethyldisiloxane is replaced with an equimolar amount of dinaphthyltetramethyldisiloxane.

[0127] Performance Test

[0128] Refer to the method in the standard of "Technical Specifications and Test Methods for Single-Phase Coolants in Data Center Immersion Liquid Cooling Systems" (T / SHSIC 0202-2023) to test the performance of the silicone coolants prepared in the above examples and comparative examples. The test results are shown in Table 1:

[0129] Table 1

[0130]

[0131]

[0132] The above results show that:

[0133] The flash points of the silicone coolants that meet the structural formula of the present invention are all above 190°C, the pour points are all below -60°C, and the thermal conductivities are all above 1.450 W / m·k (40°C). The thermal conductivity, appearance, and odor all meet the standards of data center immersion liquid cooling.

[0134] The comparison between the above examples and comparative examples further shows that the phenyl groups in the organic coolant molecule chain, the proportion of different molecular chain segments, and the interaction between side chains jointly reduce the flash point of the silicone coolant, enabling it to maintain fluidity at a lower temperature (-65°C), and the pour point can be as low as -69°C; at the same time, it can further improve the thermal conductivity and flash point of the silicone coolant.

[0135] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A silicone coolant, characterized in that, The molecular structural formula of the silicone coolant is as follows: Among them, R1 is selected from C 3～7 alkanes, the value of a ranges from 0 to 12, and the value of b ranges from 14 to 20.

2. The silicone coolant according to claim 1, wherein The values of a and b satisfy: a / b = 0 to 0.

6.

3. The silicone coolant according to claim 1, wherein R1 is selected from —C3H8, —C5H 12 or —C7H 16 .

4. The preparation method of the silicone coolant according to claim 1, characterized in that, It includes the following steps: S1: An α-olefin, tetramethyldisiloxane, and catalyst A are mixed evenly in a solvent to obtain a reaction solution, and a graft reaction is carried out to obtain modified tetramethyldisiloxane; S2: Bis(phenyl)dimethylsiloxane, methylvinylsiloxane cyclics, and dimethylsiloxane cyclics are mixed evenly, and then catalyst B is added, and a ring-opening copolymerization reaction is carried out to obtain phenylvinyl silicone oil; S3: The modified tetramethyldisiloxane obtained in step S1, the phenylvinyl silicone oil obtained in step S2, and catalyst C are mixed evenly in a solvent to obtain a reaction solution, and a graft reaction is carried out to obtain the silicone coolant.

5. The preparation method of the silicone coolant according to claim 4, characterized in that, In step S1, the molar ratio of the α-olefin to tetramethyldisiloxane is 1:1; the concentration of the α-olefin in the reaction solution is 0.1 to 2 g / mL; the mass of catalyst A is 5 to 10 ppm of the total mass of the α-olefin and tetramethyldisiloxane.

6. The preparation method of the silicone coolant according to claim 4, wherein The mass of catalyst B is 0.5 to 5% of the total mass of bis(phenyl)dimethylsiloxane, methylvinylsiloxane cyclics, and dimethylsiloxane cyclics.

7. The preparation method of the silicone coolant according to claim 4, characterized in that, In step S3, the molar ratio of the modified tetramethyldisiloxane to phenylvinyl silicone oil is (1.2 to 1.5):1; the concentration of the modified tetramethyldisiloxane in the reaction solution is 0.1 to 2 g / mL; the mass of catalyst C is 20 to 50 ppm of the total mass of the modified tetramethyldisiloxane and phenylvinyl silicone oil.

8. The preparation method of the silicone coolant according to claim 4, characterized in that, The solvents described in step S1 and step S3 independently include at least one of petroleum ether, n-hexane, ethyl acetate, and toluene.

9. The preparation method of the silicone coolant according to claim 4, characterized in that, Satisfy at least one of the following characteristics: (1) Catalyst A includes at least one of Karstedt catalyst and chloroplatinic acid catalyst; (2) The catalyst B includes at least one of concentrated sulfuric acid, trifluoromethanesulfonic acid, C 16～20 fatty acid, sulfamic acid, metal oxide, antimony pentafluoride; (3) Catalyst C includes at least one of Karstedt catalyst and chloroplatinic acid catalyst.

10. The preparation method of the silicone coolant according to claim 4, characterized in that, Satisfy at least one of the following characteristics: (1) The temperature of the reaction in step S1 is 50 to 120 °C, and the reaction time is 10 to 14 h; (2) The temperature of the reaction in step S2 is 50 to 90 °C, and the reaction time is 2 to 8 h; (3) The temperature of the reaction in step S3 is 50 to 120 °C, and the reaction time is 10 to 14 h.

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