Alkyl silicone oil for data center immersion cooling medium and method of making
By preparing alkyl silicone oil with a specific structure, the problems of turbidity and high SiH residual content at low temperatures were solved, realizing a low-energy-consumption and highly compatible immersion cooling medium for data centers, meeting the cooling needs of data centers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 江西晨光新材料股份有限公司
- Filing Date
- 2024-07-22
- Publication Date
- 2026-06-02
Smart Images
Figure CN118772409B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of cooling media, and more specifically, to an alkyl silicone oil for use as an immersion cooling medium in data centers and a method for its preparation. Background Technology
[0002] To reduce energy consumption, the Power Usage Effectiveness (PUE) of data centers needs to be lowered to a certain level. Traditional air cooling is energy-intensive and noisy. Immersion liquid cooling, which uses a fluid cooling medium in direct contact with data center equipment, can reduce the PUE to near 1, making it the most effective solution for reducing data center energy consumption. This solution requires a fluid cooling medium to transfer heat.
[0003] Existing fluid cooling media include fluorinated liquids, mineral oils, and silicone oils. Fluorinated liquids have high density and low boiling points; mineral oils, while inexpensive, have poor compatibility and aging resistance; ordinary silicone oils, although having good aging resistance, have a high dielectric constant that does not meet requirements. Therefore, modifying silicone oils to obtain cooling media with better performance is a direction of current interest to researchers. For example, patent CN 116438502A mentions a method for preparing side-chain alkyl silicone oils and also mentions the basic properties of direct cooling fluids, but the alkyl silicone oils prepared by the method mentioned in this document have a high SiH residual content. DOWSIL, commercially available... TM When the temperature is below 25°C, the silicone oil in ICL-1000 Fluid coolant becomes cloudy, limiting its application. Summary of the Invention
[0004] The primary objective of this invention is to provide an alkyl silicone oil for immersion cooling media in data centers. This alkyl silicone oil is clear and transparent at low temperatures (e.g., -30°C) while still retaining fluidity (preferably even at -40°C), which can meet a wider range of application scenarios. The process of this invention is simple, and the viscosity of the silicone oil can be flexibly adjusted according to market demands.
[0005] The alkyl silicone oil used as a cooling medium for data center immersion includes substances with the following molecular structure (I):
[0006] (CH3)3SiO[(C n H 2n+1 (CH3)SiO] m Si(CH3)3
[0007] Formula (I)
[0008] Where n is 8 or 10, and m is a positive integer not less than 4.
[0009] In a preferred embodiment of the present invention, n is 8 or 10, and m is 8 or 12.
[0010] In a preferred embodiment of the present invention, n is 8 and m is 12. Alkyl silicone oil with this structure is clear and transparent at -40°C while still retaining its fluidity, thus better meeting the requirements of immersion cooling media in data centers.
[0011] As will be known to those skilled in the art, in this invention, the value of m refers to the average value.
[0012] The alkyl silicone oil provided by this invention is clear and transparent at -30°C and still has fluidity, which can effectively meet the requirements for reducing energy consumption.
[0013] Another objective of this invention is to provide a method for preparing alkyl silicone oil, wherein the alkyl silicone oil prepared by this method has a residual SiH content of less than 1 ppm, which effectively improves the performance of the obtained alkyl silicone oil.
[0014] The preparation method of this alkyl silicone oil includes the following steps:
[0015] 1) Tetramethylcyclotetrasiloxane undergoes an addition reaction with an olefin under a platinum catalyst, followed by distillation to obtain the alkyl cyclic form;
[0016] 2) The alkyl cyclic compound obtained in step 1) and the end-capping agent are subjected to a ring-opening reaction under an acid catalyst, and the alkyl silicone oil is obtained after impurity removal.
[0017] In a specific embodiment of the present invention, the olefin can be a common olefin in the art. In a preferred embodiment of the present invention, the above preparation method can be used to prepare an alkyl silicone oil having the above structural formula (I), that is, the olefin is preferably octene or decene.
[0018] That is, the present invention provides a method for preparing alkyl silicone oil having the above-described structural formula, comprising the following steps:
[0019] 1) Tetramethylcyclotetrasiloxane is reacted with an olefin in the presence of a platinum catalyst, and the alkyl cyclic compound is obtained by distillation; the olefin is octene or decene;
[0020] 2) The alkyl cyclic compound obtained in step 1) and the end-capping agent are subjected to a ring-opening reaction under an acid catalyst, and the alkyl silicone oil is obtained after impurity removal.
[0021] In a preferred embodiment of the present invention, in order to reduce Si-H bond residues and improve the performance of the obtained alkyl silicone oil, in step 1), the molar ratio of the tetramethylcyclotetrasiloxane to the olefin is 1:(4-4.6).
[0022] In specific embodiments of the present invention, platinum catalysts commonly used in the art can be used, such as chloroplatinic acid-isopropanol, chloroplatinic acid-triphenylphosphine, or KARSTEDT catalysts, preferably KARSTEDT catalysts. The platinum catalyst, calculated as platinum, is preferably 5 to 20 ppm of the total mass of tetramethylcyclotetrasiloxane and olefins, more preferably 9 to 10 ppm.
[0023] In a preferred embodiment of the present invention, in step 1), the temperature of the addition reaction is 60-150°C and the time is 2-6 hours.
[0024] In a preferred embodiment of the present invention, in step 1), the olefin is first mixed with a platinum catalyst, activated under nitrogen protection, and tetramethylcyclotetrasiloxane is added dropwise. After the addition is completed, the reaction is carried out at 60-150°C for 2-6 hours.
[0025] After the addition reaction in step 1) is completed, the alkyl cyclic compound can be obtained by distillation at a reflux ratio of 10:5.
[0026] In a preferred embodiment of the present invention, in step 2), the acid catalyst can be sulfuric acid, acetic acid, a solid acid, or a cationic resin, preferably a solid superacid. Commonly used solid superacids in the art can be used in this invention, such as solid superacid HND-580.
[0027] In a preferred embodiment of the present invention, the capping agent is hexamethyldisiloxane.
[0028] In a preferred embodiment of the present invention, in step 2), the mass ratio of the alkyl cyclic compound to the end-capping agent is (5-20):1, preferably (9-15):1, and more preferably (9-10):1. The mass ratio of the acid catalyst is 1%-10% of the total mass of the alkyl cyclic compound and the end-capping agent, preferably 1.9-3%.
[0029] In one specific embodiment of the present invention, in step 2), the ring-opening reaction is carried out at a temperature of 50–120°C for 6–12 hours. More preferably, the ring-opening reaction is carried out at a temperature of 100°C for 10 hours.
[0030] In a specific embodiment of the present invention, after the ring-opening reaction in step 2) is completed, the catalyst is removed, and then low-boiling substances are removed (for example, by distillation at 200-240°C). After cooling to room temperature, the odor is removed (for example, by using an adsorbent to remove the odor), and the color is removed, thus obtaining alkyl silicone oil.
[0031] The alkyl silicone oil provided by this invention is clear and transparent at -30°C (preferably -40°C) while still retaining its fluidity, making it suitable for a wider range of applications. The alkyl silicone oil preparation method provided by this invention can control the residual SiH content to below 1 ppm (more preferably not higher than 0.1 ppm) and reduce the hydrocarbon residue content to below 0.5%. The alkyl silicone oil obtained by the preparation method provided by this invention, which can be used as an immersion cooling medium in data centers, does not contain -(CH3)2SiO- links, improving the dielectric properties of the alkyl silicone oil and its compatibility with other materials. Attached Figure Description
[0032] Figure 1 The 1H NMR spectrum of tetraoctyltetramethylcyclotetrasiloxane in Example 1;
[0033] Figure 2 The gas phase spectrum of tetraoctyltetramethylcyclotetrasiloxane in Example 1;
[0034] Figure 3 The image shows the 1H NMR spectrum of tetradecyltetramethylcyclotetrasiloxane from Example 2. Detailed Implementation
[0035] The specific embodiments of the present invention will be described in further detail below with reference to the examples. These examples are used to illustrate the present invention, but are not intended to limit the scope of the invention.
[0036] Example 1
[0037] 1) Tetraoctyltetramethylcyclotetrasiloxane ([(C8H) 17 Preparation of (CH3)SiO4)
[0038] 246.4 g of octene and 0.73 g of 5000 ppm KARSTEDT catalyst were added to a three-necked flask, nitrogen gas was introduced, and the mixture was activated at 50 °C for 1 h. Then, 120 g of tetramethylcyclotetrasiloxane was added dropwise through a dropping funnel, and the temperature was controlled to avoid overheating. After the addition was completed, the mixture was kept at 100 °C for 2 h, and then distilled under reduced pressure at -0.098 MPa at a reflux ratio of 10:5. After the top temperature stabilized at 245 °C, the product was collected by middle distillation to obtain tetraoctyltetramethylcyclotetrasiloxane.
[0039] The product is colorless and transparent, and no SiH bonds were detected in its 1H NMR spectrum. Figure 1 The gas phase elution peaks are typical of the four isomers of a tetracyclic system. Figure 2 And in the gas phase spectrum Figure 3 The absence of a characteristic peak for octene at 0.2 min indicates that the content of hydrocarbon residues is less than the sensitivity of the machine.
[0040] 2) Octyl silicone oil ((CH3)3SiO[(C8H) 17(CH3)SiO] 12 Preparation of Si(CH3)3
[0041] 106.2g of tetraoctyltetramethylcyclotetrasiloxane, 8.1g of hexamethyldisiloxane and 2.3g of solid superacid HND-580 were mixed and reacted at 100℃ for 10h. After the reaction was completed, the catalyst was separated and low-boiling substances were removed under high vacuum at 240℃. After cooling to room temperature, activated carbon was added to remove odor and color, and finally colorless and transparent octyl silicone oil was obtained. The properties of octyl silicone oil are shown in Table 1.
[0042] Example 2
[0043] 1) Tetradecyltetramethylcyclotetrasiloxane ([(C 10 H 21 Preparation of (CH3)SiO4)
[0044] 308 g of decene and 0.856 g of KARSTEDT catalyst (5000 ppm) were added to a three-necked flask, and the mixture was activated at 50 °C for 1 h under nitrogen purging. Then, 120 g of tetramethylcyclotetrasiloxane was added dropwise through a dropping funnel, with temperature controlled to avoid overheating. After the addition was complete, the mixture was kept at 100 °C for 2 h, followed by vacuum distillation at -0.098 MPa with a reflux ratio of 10:5. Once the top temperature stabilized, the product was collected by medium distillation at 265 °C to obtain tetradecyltetramethylcyclotetrasiloxane. The product was colorless and transparent; its 1H NMR spectrum is shown below. Figure 3 After integration calculation, the hydrogen content of the SiH bond in the product is 0.1 ppm.
[0045] 2) Decyl silicone oil ((CH3)3SiO[(C 10 H 21 Preparation of (CH3)SiO]8Si(CH3)3
[0046] 160g of tetradecyltetramethylcyclotetrasiloxane, 16.2g of hexamethyldisiloxane and 3.5g of solid superacid HND-580 were mixed and reacted at 100℃ for 10h. After the reaction was completed, the catalyst was separated, and the low boiling point was removed under high vacuum at 240℃. After cooling to room temperature, activated carbon was added to remove odor and color, and finally colorless and transparent decyl silicone oil was obtained. The properties of decyl silicone oil are shown in Table 1.
[0047] The testing methods for each performance and parameter in this invention are as follows:
[0048] The viscosity was determined at 40°C using an NDJ-79 viscometer.
[0049] The density was determined at 20°C using a 50ml standard specific gravity cup and an analytical balance, referring to standard GB / T 4472-2011.
[0050] The resistance was determined using a ZC36 high insulation resistance meter at a voltage of 250V.
[0051] The flash point was determined using a Cleveland open-cup flash point tester.
[0052] The dielectric constant was determined using a microwave network analyzer and an AC capacitance tester at 1000 Hz and 23°C, with reference to standard GB / T 5654-2007.
[0053] The moisture content was determined using an SFY-01A micro moisture analyzer.
[0054] The 1H spectrum was measured using a Bruker Avance NEO 600 nuclear magnetic resonance spectrometer with deuterated chloroform as the solvent. The peak position of SiH in the spectrum was 4.65-4.78 ppm. The SiH content was calculated by converting the integral area of SiH and the integral area of SiCH3 (near 0 ppm).
[0055] Gas chromatography was used to test residual hydrocarbons using the internal standard method with octene and decene as standards.
[0056] Compatibility test: Commercially available A56 hardness, semi-transparent electronic special silicone rubber (model SH-8160, hereinafter referred to as silicone rubber) and A71 hardness ethylene propylene rubber (purchased from Haiba Rubber) were cut into 5cm*0.5cm*0.2cm pieces respectively. After recording the initial data, they were soaked in modified silicone oil at 50℃ for 4 months. After wiping clean, the data were measured. Finally, the change rate was used for evaluation. A change rate of less than 15% was considered qualified.
[0057] Table 1 Performance of Alkyl Silicone Oils
[0058]
[0059]
[0060] Finally, the method of this invention is merely a preferred embodiment and is not intended to limit the scope of protection of this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.
Claims
1. A method for preparing an alkyl silicone oil for use as an immersion cooling medium in data centers, characterized in that, Includes the following steps: 1) Tetramethylcyclotetrasiloxane is reacted with an olefin in the presence of a platinum catalyst, and the alkyl cyclic compound is obtained by distillation; the olefin is octene or decene; 2) The alkyl cyclic compound obtained in step 1) and the end-capping agent are subjected to a ring-opening reaction under an acid catalyst, and the alkyl silicone oil is obtained after impurity removal; The alkyl silicone oil includes substances with the following molecular structure (I): ； Formula (I), Where n is 8 and m is 12; or n is 10 and m is 8.
2. The preparation method according to claim 1, characterized in that, The value of n is 8, and the value of m is 12.
3. The preparation method according to claim 1 or 2, characterized in that, In step 1), the molar ratio of tetramethylcyclotetrasiloxane to olefin is 1:(4~4.6); the platinum catalyst is 5~20 ppm of the total mass of tetramethylcyclotetrasiloxane and olefin, calculated as platinum.
4. The preparation method according to claim 3, characterized in that, In step 1), the platinum catalyst is 9-10 ppm of the total mass of tetramethylcyclotetrasiloxane and olefins, calculated as platinum.
5. The preparation method according to claim 1 or 2, characterized in that, In step 1), the temperature of the addition reaction is 60-150°C and the time is 2-6 hours.
6. The preparation method according to claim 1 or 2, characterized in that, In step 2), the acid catalyst is a solid superacid; And / or, the capping agent is hexamethyldisiloxane.
7. The preparation method according to claim 1 or 2, characterized in that, In step 2), the mass ratio of the alkyl cyclic compound to the capping agent is (5~20):1; And / or, the acid catalyst is 1% to 10% of the total mass of the alkyl cyclic compound and the end-capping agent.
8. The preparation method according to claim 7, characterized in that, In step 2), the mass ratio of the alkyl cyclic compound to the end-capping agent is (9~15):
1.
9. The preparation method according to claim 7, characterized in that, In step 2), the acid catalyst is 1.9% to 3% of the total mass of the alkyl cyclic compound and the end-capping agent.
10. The preparation method according to claim 1 or 2, characterized in that, In step 2), the ring-opening reaction is carried out at a temperature of 50–120°C for 6–12 hours.