Method for continuously synthesizing long-chain alkyl modified silicone oil

Abstract

The invention discloses a method for continuously synthesizing long-chain alkyl modified silicone oil, which belongs to the technical field of organic synthesis, and comprises the following specific steps: quickly mixing hydrogen-containing silicone oil and long-chain olefin in a micro-mixer, carrying out hydrosilylation reaction in a packed tubular reactor, controlling the reaction residence time by using the tube length, and continuously synthesizing the long-chain alkyl modified silicone oil. Controlling the material ratio by utilizing the reaction liquid flow ratio, controlling the reaction temperature by utilizing a water bath, and obtaining a mixed solution containing modified silicone oil after the reaction is completed; and decoloring the mixed solution by using activated carbon, and then carrying out reduced pressure rotary evaporation on the decolored mixed solution to finally obtain a modified silicone oil pure product. The method realizes continuous synthesis of the modified silicone oil, and has the advantages of simple process, short reaction time and high reaction safety.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and more specifically to a method for the continuous synthesis of long-chain alkyl-modified silicone oils using a microreactor. Background Art

[0002] The synthesis of long-chain alkyl-modified silicone oils generally involves hydrosilylation reactions, which are addition reactions between organosilicon compounds containing Si-H bonds and unsaturated long-chain olefins under certain conditions. This reaction is easy to control and yields high products, thus holding an important position in the field of organosilicon chemistry.

[0003] Long-chain alkyl-modified silicone oils have a wide range of applications. In the industrial sector, they can be used in metal processing and machinery manufacturing as lubricant additives to improve equipment operating efficiency and extend service life. In the daily chemical industry, they are commonly used in skincare and cosmetic products to provide moisturizing effects, enhance product smoothness and skin affinity, and can also be used as lubricants in personal care products, such as shaving cream, to improve user comfort. In agriculture, they can be used as pesticide adjuvants to improve pesticide efficacy and reduce environmental pollution. In the liquid cooling field of data centers, olefin-modified silicone oils can be used as single-phase immersion coolants. Through direct contact and circulation with data center equipment, they remove heat, improve heat exchange efficiency, ensure server temperature stability, and reduce the PUE (Power Usage Effectiveness) of data centers. Compared with other cooling media, modified silicone oils have advantages such as relatively low cost, relatively high flash point, high stability, and strong material compatibility.

[0004] Chinese invention patent (CN117924709A) discloses a long-chain alkyl-modified polysiloxane and its preparation method. The preparation method includes: uniformly mixing hydrogen-containing silicone oil and olefin-modified silicone oil, heating; initially adding a catalyst, then dropwise adding a first olefin, and conducting a first heat-preserving reaction; subsequently adding the catalyst again, then dropwise adding a second olefin, and conducting a second heat-preserving reaction; and finally obtaining the long-chain alkyl-modified polysiloxane by vacuum distillation. The above synthesis method uses a batch-type dropwise addition process, with a reaction time exceeding 4 hours and a silicon-hydrogen conversion rate greater than 89%.

[0005] Chinese invention patent (CN117820645A) discloses a method for preparing long-chain alkylphenyl modified silicone oil. The method includes the following steps: adding hydrogen-containing silicone oil to a reaction vessel and preheating; premixing a catalyst with phenyl unsaturated olefins and long-chain alkyl unsaturated olefins; adding the two materials containing the premixed catalyst separately to the reaction vessel, maintaining the temperature, and removing low-boiling substances to obtain long-chain alkylphenyl modified silicone oil. This process also employs a batch-type dropwise addition process, and there is a significant temperature rise (approximately 10°C) during the dropwise addition of the catalyst mixture, posing a high risk. Furthermore, this process still requires a high holding temperature (140-150°C) and a long holding time (30 min), resulting in low reaction efficiency.

[0006] Chinese invention patent (CN117624212A) discloses a method for preparing octyl polymethylsiloxane via continuous reaction in a fixed-bed microreactor. Using 1,1,1,3,5,5,5-heptamethyltrisiloxane and 1-octene as raw materials, the reaction is carried out continuously in a micro-packed bed reactor filled with platinum-carbon solid particulate catalyst. This method offers shorter reaction time and higher conversion and selectivity. However, this process involves a heterogeneous solid-liquid catalytic reaction, requiring a high platinum content (0.3%~3%) in the platinum-carbon catalyst. Furthermore, the effective components of the solid catalyst are continuously lost as the reaction time increases, leading to a decrease in catalytic efficiency.

[0007] Based on the above, it is of great significance to develop a method for the continuous synthesis of long-chain alkyl-modified silicone oils under the catalysis of platinum complexes.

[0008] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0009] The main objective of this invention is to provide a method for the continuous synthesis of long-chain alkyl-modified silicone oils. This method has a simple process, requires less catalyst, has a short reaction time, is safe to operate, and allows for more precise temperature control.

[0010] To achieve the above objectives, the present invention provides a method for the continuous synthesis of long-chain alkyl-modified silicone oil, comprising the following steps:

[0011] A method for continuous synthesis of long-chain alkyl-modified silicone oil, characterized by comprising the following steps:

[0012] (1) Take a certain amount of hydrogen-containing silicone oil as feed liquid A, and take a certain amount of long-chain olefin, isopropanol and platinum complex catalyst to mix to form feed liquid B;

[0013] (2) Pump liquid A and liquid B into micro mixer I at a set flow rate for rapid mixing. The mixed material is then transported to packed tubular reactor I for hydrosilylation reaction. The reactants are controlled by a water bath to react at a certain temperature for a period of time, and finally a mixture containing modified silicone oil is obtained.

[0014] (3) The mixture containing modified silicone oil was adsorbed and decolorized with activated carbon to obtain a clear and transparent mixed solution;

[0015] (4) The decolorized mixed solution was subjected to reduced pressure rotary evaporation to remove low-boiling-point substances, and pure olefin-modified silicone oil product was obtained.

[0016] Preferably, the hydrogen content of the hydrogen-containing silicone oil is in the range of 0.1% to 0.2%;

[0017] Preferably, the long-chain olefin is an olefin containing 7 to 12 carbons;

[0018] Preferably, the amount of isopropanol used is 10% to 20% of the total mass of the hydrogen-containing silicone oil and the long-chain olefin;

[0019] Preferably, the amount of platinum complex catalyst used ranges from 5 ppm to 10 ppm of the total mass of hydrogen-containing silicone oil and long-chain olefins;

[0020] Preferably, the flow rate of feed solution A is in the range of 1 mL / min to 4 mL / min;

[0021] Preferably, the flow rate of feed solution B is in the range of 0.5 mL / min to 4 mL / min;

[0022] Preferably, the flow rate ratio of liquid A to liquid B is in the range of 1:(0.5~1).

[0023] Preferably, the dispersion size of the micromixer I is in the range of 150 μm to 750 μm;

[0024] Preferably, the packing material inside the packed tubular reactor is a customized small spring microstructure with a porosity of 68%, an inner diameter of 3 mm, and an outer diameter of 4 mm.

[0025] Preferably, the reaction temperature in the water bath is controlled within the range of 80~95℃;

[0026] Preferably, the reaction residence time is 60s to 240s.

[0027] Preferably, the activated carbon is in powder form, and the amount used ranges from 1% to 5% of the mass of the solution to be adsorbed and decolorized.

[0028] Preferably, the temperature of the reduced pressure rotary evaporation is 120℃~150℃, and the evaporation time is 2h~6h.

[0029] The beneficial effects of this invention are:

[0030] 1. The hydrosilylation reaction of hydrogen-containing silicone oil with long-chain olefins was realized by using a micro-reaction continuous flow process, which ensured the safety of the reaction process. The reaction temperature of this method is lower than that of the batch process, no heat preservation is required after the reaction is completed, and the reaction time is shorter.

[0031] 2. The two fluids are rapidly and efficiently mixed in the micro-mixer, instantly achieving a uniform reaction environment with high reaction efficiency. Compared with the use of platinum-carbon catalyst, the amount of homogeneous platinum complex catalyst used in this method is greatly reduced.

[0032] 3. A novel micro-reaction continuous synthesis process was developed, which is easy to monitor and control the reaction process and easy to scale up production. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the process flow for the continuous synthesis of long-chain alkyl-modified silicone oil in a microreactor according to the embodiments of the present invention.

[0034] Figure 2 NMR spectrum of octene-modified silicone oil in the examples;

[0035] Figure 3 This is a gas chromatogram of the octene-modified silicone oil reaction solution.

[0036] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the described embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0038] This application proposes a method for the continuous synthesis of long-chain alkyl-modified silicone oil, comprising the following steps:

[0039] (1) Take a certain amount of hydrogen-containing silicone oil as feed liquid A and store it in storage tank 1 of A. Take a certain amount of long-chain olefin, isopropanol and platinum complex catalyst and mix them to form feed liquid B and store it in storage tank 2 of B.

[0040] (2) The liquid A and liquid B are pumped into the micro mixer I 5 at the set flow rate through metering pump 3 and metering pump 4 respectively. The mixed material is then transported to the packed tubular reactor I 6 for hydrosilylation reaction. The reactants are controlled by water bath to react at a certain temperature for a period of time. Finally, a mixture containing modified silicone oil is obtained and stored in the mixture storage tank 7.

[0041] (3) The mixture containing modified silicone oil was adsorbed and decolorized with activated carbon to obtain a clear and transparent mixed solution;

[0042] (4) The decolorized mixed solution was subjected to reduced pressure rotary evaporation to remove low-boiling-point substances and obtain pure olefin-modified silicone oil product.

[0043] Example 1

[0044] (1) Take 500g of hydrogen-containing silicone oil with a hydrogen content of 0.11% and store it in reagent bottle A to form reaction solution A. Take 500g of n-heptene, 100g of isopropanol and 1g of platinum complex catalyst and mix them in reagent bottle B to form solution B.

[0045] (2) Reactant solution A and reactant solution B were pumped into a micro-mixer I with a dispersion scale of 150 μm at set flow rates of 1 mL / min and 0.5 mL / min, respectively, for rapid mixing. The mixed material was then transported to a packed tubular reactor I for hydrosilylation reaction. The packing material inside the packed tubular reactor was a custom-designed small spring microstructure with a porosity of 68%, an inner diameter of 3 mm, and an outer diameter of 4 mm. The reactants were controlled to react at a temperature of 85 °C using a water bath, with a residence time of 60 s, ultimately yielding a mixture containing modified silicone oil.

[0046] (3) Add 1% by mass of powdered activated carbon to the mixture containing modified silicone oil collected in the reactor for adsorption and decolorization to obtain a clear and transparent mixed solution.

[0047] (4) The decolorized mixed solution was subjected to reduced pressure rotary evaporation at 150°C for 4 hours to remove low-boiling-point substances and obtain pure olefin-modified silicone oil product.

[0048] Gas chromatography analysis showed that the olefin conversion rate was 99.34%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0049] Example 2

[0050] The difference between this embodiment and Embodiment 1 is that the dispersion scale of the micromixer is 750 μm.

[0051] Gas chromatography analysis showed that the olefin conversion rate was 97.66%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0052] Example 3

[0053] The difference between this embodiment and Embodiment 1 is that reaction solution A and reaction solution B are fed into the microreactor at set flow rates of 4 mL / min and 4 mL / min, respectively.

[0054] Gas chromatography analysis showed that the olefin conversion rate was 95.62%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0055] Example 4

[0056] The difference between this embodiment and Example 1 is that 500g of n-heptene, 200g of isopropanol, and 1g of platinum complex catalyst are mixed in reagent bottle B to form liquid B.

[0057] Gas chromatography analysis showed that the olefin conversion rate was 99.51%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0058] Example 5

[0059] The difference between this embodiment and Example 1 is that 500g of n-heptene, 100g of isopropanol, and 2g of platinum complex catalyst are mixed in reagent bottle B to form liquid B.

[0060] Gas chromatography analysis showed that the olefin conversion rate was 99.89%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0061] Example 6

[0062] The difference between this embodiment and Embodiment 1 is that a water bath is used to control the reaction of the reactants at a temperature of 95°C.

[0063] Gas chromatography analysis showed that the olefin conversion rate was 96.45%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0064] Example 7

[0065] The difference between this embodiment and Embodiment 1 is that 3% by mass of powdered activated carbon is added to the mixture containing modified silicone oil collected in the reactor for adsorption and decolorization.

[0066] Gas chromatography analysis showed that the olefin conversion rate was 99.34%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0067] Example 8

[0068] The difference between this embodiment and Embodiment 1 is that the decolorized mixed solution is subjected to reduced pressure rotary evaporation at 120°C for 4 hours to remove low-boiling-point substances.

[0069] Gas chromatography analysis showed that the olefin conversion rate was 99.34%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0070] Example 9

[0071] The difference between this embodiment and Embodiment 1 is that the decolorized mixed solution is subjected to reduced pressure rotary evaporation at 150°C for 6 hours to remove low-boiling-point substances.

[0072] Gas chromatography analysis showed that the olefin conversion rate was 99.34%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0073] Example 10

[0074] The difference between this embodiment and Example 1 is that 500g of n-octene, 100g of isopropanol, and 1g of platinum complex catalyst are mixed in reagent bottle B to form liquid B.

[0075] Gas chromatography analysis showed that the olefin conversion rate was 99.65%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

[0076] Example 11

[0077] The difference between this embodiment and Example 1 is that 500g of 1-dodecene, 100g of isopropanol, and 1g of platinum complex catalyst are mixed in reagent bottle B to form liquid B.

[0078] Gas chromatography analysis showed that the olefin conversion rate was 95.23%, and the final product contained no long-chain olefins or isopropanol residues. Quantitative NMR analysis showed that the Si-H bond conversion rate of the hydrogen-containing silicone oil was 100%. Visual inspection revealed that the reaction solution was clear and transparent.

Claims

1. A method for the continuous synthesis of long-chain alkyl-modified silicone oil, characterized in that, Includes the following steps: (1) Take a certain amount of hydrogen-containing silicone oil as feed liquid A, and take a certain amount of long-chain olefin, isopropanol and platinum complex catalyst to mix to form feed liquid B; (2) Pump liquid A and liquid B into micro mixer I at a set flow rate for rapid mixing. The mixed material is then transported to packed tubular reactor I for hydrosilylation reaction. The reaction material is controlled by a water bath at a certain temperature to finally obtain a mixture containing modified silicone oil. (3) The mixture containing modified silicone oil was adsorbed and decolorized with activated carbon to obtain a clear and transparent mixed solution; (4) The decolorized mixed solution was subjected to reduced pressure rotary evaporation to remove low-boiling-point substances and obtain pure olefin-modified silicone oil product.

2. The method according to claim 1, characterized in that, The hydrogen content of the hydrogen-containing silicone oil in step (1) ranges from 0.1% to 0.2%; the long-chain olefin is an olefin containing 7 to 12 carbons; the amount of isopropanol used ranges from 10% to 20% of the total mass of the hydrogen-containing silicone oil and the long-chain olefin; and the amount of platinum complex catalyst used ranges from 5 ppm to 10 ppm of the total mass of the hydrogen-containing silicone oil and the long-chain olefin.

3. The method according to claim 1, characterized in that, In step 2, the flow rate of liquid A is in the range of 1 mL / min to 4 mL / min, the flow rate of liquid B is in the range of 0.5 mL / min to 4 mL / min, and the flow rate ratio of liquid A to liquid B is in the range of 1:(0.5~1).

4. The method according to claim 1, characterized in that, The dispersion size range of the micro-mixer I in step (2) is 150μm~750μm; the packing material inside the packed tubular reactor is a customized small spring microstructure with a porosity of 68%, an inner diameter of 3mm, and an outer diameter of 4mm; the water bath controls the reaction temperature range of 80~95℃ and the reaction residence time is 60s~240s.

5. The method according to claim 1, characterized in that, The activated carbon in step (3) is in powder form, and the amount used is 1% to 5% of the mass of the decolorizing solution to be adsorbed.

6. The method according to claim 1, characterized in that, The temperature of the reduced pressure rotary evaporation in step (4) is 120℃~150℃, and the evaporation time is 2h~6h.

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