Preparation method of low platinum removal catalyst for silicon-hydrogen structure
By delowing the platinum catalyst preparation method, small molecule silicone oil and silicone impurities in the platinum catalyst are removed, and the performance deterioration caused by traditional catalysts is solved, achieving extremely low volatility and excellent material properties.
Patent Information
- Application Number
- CN202510082887.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2025-05-02
AI Technical Summary
Traditional platinum catalysts carry small molecule silicone oil and silicone impurities during the preparation of hydrogen silicon structures, resulting in performance deterioration problems during use of the products, such as short circuits in semiconductor devices and reduced light transmittance of optical components.
The preparation method of delow platinum catalyst is adopted. By mixing the platinum catalyst stock solution with silicone oil in a specific proportion, and delowing the treatment under rotary evaporation conditions, and then mixing it with delow vinyl silicone oil to form a platinum catalyst system with low concentration zero siloxane content.
The volatile precursors such as small molecule silicone oil in the platinum catalyst are effectively removed, and the silicone content reaches 0, which significantly reduces the volatility of subsequent materials, avoids the performance deterioration caused by volatile migration, and improves the reliability and service life of the product.
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Figure CN119909707A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of catalyst preparation, and in particular to a method for preparing a de-platinum catalyst for a silicon-hydrogen structure. Background Art
[0002] In many fields such as electronics, optics and precision instruments, many products have extremely strict requirements on the volatile matter and siloxane content in silicone rubber products. For example, in products such as semiconductor packaging, optical lens coating, high-end smartphone components and medical equipment, even trace amounts of volatile matter or siloxane impurities are likely to cause serious performance problems.
[0003] The formation of silicon-hydrogen structure mainly depends on the reaction of hydrogenated silicone oil and vinyl silicone oil, and in this reaction process, platinum catalyst plays a key role. The molecular structure of hydrogenated silicone oil contains Si-H bond, and vinyl silicone oil contains vinyl (-CH=CH 2 ), when hydrogen-containing silicone oil and vinyl silicone oil are mixed together, in the absence of a catalyst, the reaction usually does not occur or the reaction rate is extremely slow. This is because there is a certain energy barrier for the reaction between the Si-H bond and the vinyl group, which requires energy or a catalyst to initiate the reaction. When a platinum catalyst is added, the two react with silyl hydrogen under the action of the catalyst to form a new Si-C bond, thereby constructing a silicon-hydrogen structure. However, traditional platinum catalysts often carry small molecule silicone oil and siloxane impurities. These impurities volatilize during the use of the product, which may cause adverse consequences such as short circuits in semiconductor devices, changes in the refractive index of optical components, failure of precision instrument sensor components, and reduced biocompatibility of medical devices.
[0004] In the prior art, the main focus is on the preparation of hydrogen-containing silicone oil itself, and low-volatile hydrogen-containing silicone oil is prepared through specific reaction steps and raw material ratios, but the platinum catalyst used is a supported chloroplatinic acid structure with platinum carbon as the carrier. Summary of the invention
[0005] In view of the above problems, the present application is proposed to provide a method for preparing a de-platinum catalyst for a silicon-hydrogen structure that overcomes the above problems or at least partially solves the above problems, comprising:
[0006] A method for preparing a platinum removal catalyst for a silicon-hydrogen structure, comprising the steps of:
[0007] The platinum catalyst stock solution and the silicone oil are mixed in a ratio of 1:0.5-2 by mass to obtain a liquid to be evaporated; wherein the platinum content of the platinum catalyst stock solution is 2.5×10 5 -4.0×10 5 ppm;
[0008] Rotary distilling the liquid to be distilled at a first temperature for a first period of time to obtain a deionized liquid;
[0009] The de-plating liquid and de-plating vinyl silicone oil are mixed in a ratio of 1:29 to obtain a de-plating platinum catalyst liquid.
[0010] Furthermore, it also includes:
[0011] The de-platinum catalyst liquid is subjected to a volatilization measurement; specifically, the de-platinum catalyst liquid is placed on a heating platform, and a watch glass is placed on the mouth of a container of the de-platinum catalyst liquid;
[0012] Raising the temperature of the heating platform to a second temperature, and baking the de-platinum catalyst liquid for a second time period;
[0013] The volatility of the de-platinum catalytic solution is determined based on the light transmittance of the watch glass.
[0014] Furthermore, the second temperature is 90°C.
[0015] Furthermore, the second duration is 4 hours.
[0016] Furthermore, the first temperature is 85-95°C.
[0017] Furthermore, the first duration is 4-6 hours.
[0018] Furthermore, the vinyl content of the de-vinylized silicone oil is 0.2-0.6%.
[0019] Furthermore, the platinum catalyst stock solution is a Speier catalyst or a Karstedt catalyst.
[0020] Furthermore, in the step of rotary evaporating the liquid to be evaporated at a first temperature for a first period of time to obtain the desalted liquid, the rotation speed of the rotary evaporation is 10-15 r / min.
[0021] Furthermore, the viscosity of the silicone oil is 200-1000 mPa.s.
[0022] This application has the following advantages:
[0023] In the embodiments of the present application, in view of the disadvantage that the platinum catalyst in the prior art carries small molecule silicone oil and siloxane impurities, which may cause problems in subsequent semiconductor devices, the present application provides a method for preparing a platinum catalyst for a silicon hydrogen structure, comprising the steps of: mixing a platinum catalyst stock solution and silicone oil in a ratio of 1:0.5-2 by mass to obtain a liquid to be evaporated; wherein the platinum content of the platinum catalyst stock solution is 2.5×10 5 -4.0×10 5ppm; rotary evaporate the liquid to be evaporated at a first temperature for a first time to obtain a dehydrogenated liquid; mix the dehydrogenated liquid with dehydrogenated vinyl silicone oil at a ratio of 1:29 to obtain a dehydrogenated platinum catalyst liquid. Through the dehydrogenation treatment process, volatile precursors such as small molecule silicone oil in the platinum catalyst can be almost completely removed, and the siloxane content reaches 0. In the subsequent application in the preparation of various materials involving silicon-hydrogen structures, extremely low volatility can be achieved, effectively avoiding the performance degradation problem caused by the migration of volatiles to key parts of the product in the application of products sensitive to volatiles. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the description of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0025] Figure 1 It is a flow chart of the steps of a method for preparing a de-platinum catalyst for a silicon-hydrogen structure provided in one embodiment of the present application. DETAILED DESCRIPTION
[0026] In order to make the objects, features and advantages of the present application more obvious and understandable, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0027] The inventors analyzed the prior art and found that the prior art only focused on the purity of the raw materials when preparing equipment for silicon-hydrogen structures, but did not process the catalyst. The platinum catalyst is a supported chloroplatinic acid structure with platinum carbon as a carrier, which often contains volatiles or siloxane impurities, affecting the performance of the finished product.
[0028] Reference Figure 1 , showing a flow chart of steps of a method for preparing a platinum removal catalyst for a silicon-hydrogen structure provided in an embodiment of the present application:
[0029] The method comprises:
[0030] S110, mixing a platinum catalyst stock solution and silicone oil in a ratio of 1:0.5-2 by mass to obtain a liquid to be evaporated; wherein the platinum content of the platinum catalyst stock solution is 2.5×10 5 -4.0×10 5 ppm;
[0031] S120, rotary evaporating the liquid to be evaporated at a first temperature for a first period of time to obtain a desalted liquid;
[0032] S130, mixing the de-catalyzing liquid and the de-catalyzing vinyl silicone oil in a ratio of 1:29 to obtain a de-catalyzing platinum catalyst liquid.
[0033] In the embodiments of the present application, in view of the disadvantage that the platinum catalyst in the prior art carries small molecule silicone oil and siloxane impurities, which may cause problems in subsequent semiconductor devices, the present application provides a method for preparing a platinum catalyst for a silicon hydrogen structure, comprising the steps of: mixing a platinum catalyst stock solution and silicone oil in a ratio of 1:0.5-2 by mass to obtain a liquid to be evaporated; wherein the platinum content of the platinum catalyst stock solution is 2.5×10 5 -4.0×10 5 ppm; rotary evaporate the liquid to be evaporated at a first temperature for a first time to obtain a dehydrogenated liquid; mix the dehydrogenated liquid with dehydrogenated vinyl silicone oil at a ratio of 1:29 to obtain a dehydrogenated platinum catalyst liquid. Through the dehydrogenation treatment process, volatile precursors such as small molecule silicone oil in the platinum catalyst can be almost completely removed, and the siloxane content reaches 0. In the subsequent application in the preparation of various materials involving silicon-hydrogen structures, extremely low volatility can be achieved, effectively avoiding the performance degradation problem caused by the migration of volatiles to key parts of the product in the application of products sensitive to volatiles.
[0034] Compared with the traditional platinum catalyst, the present invention can almost completely remove the volatile precursors such as small molecule silicone oil in the platinum catalyst through a unique rotary evaporator degassing process, and the siloxane content reaches 0. When it is subsequently applied to the preparation of various materials involving silicon-hydrogen structures, according to a specific volatile test method, whether it is a separate test of the degassing platinum catalyst (such as 30g is placed in a conical bottle with a watch glass and placed on a heating platform at 90°C for 4 hours, there is no visible volatile condensate on the surface of the watch glass, and the transmittance is △<0.5% tested by a haze meter) or a test of a finished product made using the catalyst (such as placed in a conical bottle with a glass cover and placed on a heating platform at 150°C for 24 hours, there is no visible volatile condensate on the surface of the watch glass, and the transmittance is △<0.5% tested by a haze meter), both show extremely low volatile levels. This effectively avoids performance degradation problems caused by the migration of volatiles to key parts of products (such as security camera lenses, inside semiconductor devices, optical lens surfaces, precision components of smartphones, etc.) in product applications that are sensitive to volatiles, such as camera fogging, semiconductor short circuits, reduced light transmittance of optical components, corrosion of mobile phone components, etc., greatly improving the reliability and service life of the products.
[0035] Next, a method for preparing a de-platinum catalyst for a silicon-hydrogen structure in this exemplary embodiment will be further described.
[0036] As described in step S110, the platinum catalyst stock solution and the silicone oil are mixed in a ratio of 1:0.5-2 by mass to obtain a liquid to be evaporated; wherein the platinum content of the platinum catalyst stock solution is 2.5×
[0037] 10 5 -4.0×10 5 ppm.
[0038] It should be noted that the optimal ratio of the platinum catalyst stock solution to the silicone oil is 1:1, and the silicone oil can be de-vinylized silicone oil, which is convenient for the subsequent configuration of the finished de-platinum catalyst through vinyl silicone oil.
[0039] In one embodiment of the present invention, the platinum catalyst stock solution is a Speier catalyst or a Karstedt catalyst.
[0040] In one embodiment of the present invention, the viscosity of the silicone oil is 200-1000 mPa.s.
[0041] As described in step S120, the liquid to be evaporated is subjected to rotary evaporation at a first temperature for a first period of time to obtain a desalted liquid.
[0042] It should be noted that the rotary evaporation can be set to reduced pressure distillation, which is convenient for controlling the heating temperature and improving the distillation efficiency.
[0043] In one embodiment of the present invention, the first temperature is 85-95°C.
[0044] In one embodiment of the present invention, the first duration is 4-6 hours.
[0045] In one embodiment of the present invention, the rotation speed of the rotary evaporator is 10-15 r / min.
[0046] It should be noted that the small molecule silicone oil in the platinum catalyst can be removed through negative pressure rotary evaporation, and the siloxane content is almost zero, effectively removing volatile substances in the platinum catalyst system that have a negative impact on subsequent reactions.
[0047] As described in step S130, the de-plating liquid and the de-plating vinyl silicone oil are mixed in a ratio of 1:29 to obtain the de-plating platinum catalyst liquid.
[0048] In one embodiment of the present invention, the vinyl content of the de-vinylized silicone oil is 0.2-0.6%.
[0049] It should be noted that the low-concentration platinum catalyst system with zero siloxane content formed by mixing the de-depleted liquid with the de-depleted vinyl silicone oil in a ratio of 1:29 can play a more accurate catalytic role in the silicon-hydrogen structure reaction of hydrogen-containing silicone oil and vinyl silicone oil. It has high catalytic activity and can effectively promote the reaction at a relatively low temperature (room temperature to about 100°C), greatly accelerate the reaction rate, and enable the reaction to reach a higher conversion rate in a shorter time; it has good selectivity, mainly catalyzes the target silicon-hydrogen addition reaction, inhibits side reactions such as double bond self-polymerization, and ensures product quality and performance; the reaction conditions are mild, and harsh conditions such as high temperature and high pressure are not required, which is conducive to industrial production and laboratory operations. When preparing silicon-hydrogen structural materials, it can effectively promote the uniform progress and full conversion of the reaction, so that the prepared materials have better performance. For example, in thermally conductive silicone used for semiconductor packaging, the optimization of its silicon-hydrogen structure helps to stabilize the thermal conductivity to 3.5-4.5W / (m·K), and the volume resistivity is greater than 1.0×1015Ω·cm, providing good protection for the heat dissipation and insulation of semiconductor devices; in protective coatings for optical lenses, the transmittance can reach more than 98% in the visible light range and the transmittance change rate after aging is less than 0.5%, effectively protecting the optical properties of optical lenses; in high-end smartphone waterproof sealants, the waterproof grade reaches IP68 and the volatile content is less than 0.05%, ensuring the waterproof seal of the mobile phone in complex environments and the stability of internal components; in silicone components for medical equipment, it meets strict biocompatibility standards, and the performance remains stable after high-temperature steam sterilization cycles without volatile release, ensuring the safety and effectiveness of medical equipment use.
[0050] In one embodiment of the present invention, the steps are further included:
[0051] The de-platinum catalyst liquid is subjected to a volatilization measurement; specifically, the de-platinum catalyst liquid is placed on a heating platform, and a watch glass is placed on the mouth of a container of the de-platinum catalyst liquid;
[0052] Raising the temperature of the heating platform to a second temperature, and baking the de-platinum catalyst liquid for a second time period;
[0053] The volatility of the de-platinum catalytic solution is determined based on the light transmittance of the watch glass.
[0054] In one embodiment of the present invention, the second temperature is 90°C.
[0055] In an embodiment of the present invention, the second duration is 4 hours.
[0056] It should be noted that the siloxane content in the de-platinum catalyst liquid can be first detected by a precision analytical instrument to determine whether the siloxane content is 0, and then a volatility test can be performed. By comparing the transmittance of the surface dish before and after, it can be determined whether the de-platinum catalyst contains volatile substances at the second temperature, and the transmittance difference before and after the haze meter test meets the standard, which is generally a transmittance <0.5%.
[0057] The method for preparing a platinum-free catalyst of the present invention only requires placing the platinum catalyst in a rotary evaporator and treating it under specific temperature (85-95°C) and time (4-6 hours). The process steps are concise and clear, and easy to operate and control. In addition, in the process of processing raw materials of different batches, it has been verified by multiple experiments that a platinum-free catalyst with a siloxane content of 0 can be stably obtained, and when it is subsequently mixed with vinyl silicone oil and applied to material preparation, it exhibits consistent low volatile properties and good material performance improvement effects. This shows that the preparation process of the present invention has strong repeatability, which is conducive to ensuring the stability and consistency of product quality in the actual production process, reducing the product quality risk caused by process fluctuations, and further enhancing the competitiveness of the present invention in industrial applications.
[0058] In a specific implementation, the preparation of the platinum removal catalyst and the volatile condensate test:
[0059] A certain amount of high-concentration platinum catalyst and de-silicone oil were placed in a rotary evaporator, the temperature was set to 95°C, the rotary evaporation program was started and maintained for 6 hours to obtain a de-silicone liquid, and the de-silicone liquid was slowly mixed with the pre-de-silicone treated vinyl silicone oil in a ratio of 1:29 under inert gas protection to obtain a low-concentration platinum catalyst mixed system with zero siloxane content.
[0060] After the treatment, the siloxane content was tested using a precision analytical instrument, and the result showed that the siloxane content was 0;
[0061] Subsequently, 30 g of the de-deoxidized platinum catalyst was placed in a conical flask with a glass cover, placed on a heating platform, and baked at 90° C. for 4 hours. After baking, the surface of the glass cover was observed, and no volatile condensate was visible. The transmittance was tested by a haze meter and was less than 0.5%, indicating that the volatile content of the de-deoxidized platinum catalyst itself was extremely low and met the requirements.
[0062] Preparation of low-volatile thermally conductive silicone gaskets by removing the platinum catalyst and performance testing:
[0063] The proportions of the raw materials are shown in Table 1:
[0064] Example 1 Example 2 Example 3 Example 4 Vinyl silicone oil 375 375 375 375 Hydrogen silicone oil 40 38 36 33 Thermal Conductive Powder 580 580 580 580 Inhibitors 1 1 1 1 Platinum Catalyst 4 3.8 3.6 3.5
[0065] Table 1
[0066] Prepare 4 sets of thermally conductive silicone gaskets. According to the above ratio, mix the de-platinum catalyst with hydrogen-containing silicone oil, high thermal conductive filler (such as boron nitride powder, aluminum oxide, zinc oxide) and an appropriate amount of inhibitor (acetylene cyclohexanol, used to control the reaction rate) in a vacuum planetary mixer, and then inject them into the semiconductor packaging mold and cure them at a temperature of 150-180°C.
[0067] The performance of the prepared thermally conductive silicone was tested, and its thermal conductivity reached 3.5-4.5W / (m·K).
[0068] For the test of volatile content, take an appropriate amount of the prepared thermal conductive silicone finished product into a conical bottle with a glass cover, place it on a heating platform and bake it at 180℃ for 36 hours. After the end, observe the surface of the glass cover and there is no visible volatile condensate. The haze meter test shows that the transmittance is △<0.5%, which fully proves that the prepared thermal conductive silicone for semiconductor packaging has very few volatiles in a high temperature environment and meets the requirements for strict control of material volatiles in the semiconductor packaging field. The thermal conductive silicone is applied to the semiconductor packaging process. After long-term high-temperature aging tests and electrical performance tests, the semiconductor devices do not have short circuits or performance degradation caused by volatiles.
[0069] The experimental data of the test of 4 groups of thermal conductive silicone gaskets are shown in Table 2:
[0070]
[0071] Table 2
[0072] Among them, the thermal conductivity is tested according to ISO22007-2;
[0073] Among them, the volatile condensate uses a constant temperature heating table + a conical flask with a watch glass, 150℃&24H;
[0074] Among them, the light transmittance is tested according to ASTM D1003.
[0075] Volatile condensate test method:
[0076] Sampling: Take samples with a diameter of 53mm for thermally conductive silicone gaskets, and the thickness must be more than 2.0mm;
[0077] Testing instruments and equipment: temperature control heating plate with an accuracy of ±1°C, clean conical flask, watch glass.
[0078] Take a 53mm diameter round sample and put it into a clean round bottle with a thickness of more than 2.0mm. Then put it on a high-precision digital constant temperature heating table, set the temperature to 150℃, cover it with a clean and transparent watch glass, heat it for 16 hours, turn off the temperature control heating plate switch, cool it to room temperature, and regularly observe and touch the watch glass with your fingers to see if there is any volatile condensate.
[0079] Light transmittance test method:
[0080] Calibration: Open the test protection cover and measure the air standard for calibration;
[0081] Place the sample before testing on the center of the test bench and place a clean and transparent watch glass on it, measure the standard sample data, and record the initial data of the sample before testing;
[0082] After the "volatile condensate test" in the previous step, the sample is the tested sample. Place the sample in the center of the measuring table for testing and record the data after the test.
[0083] The test result is the data after the test minus the data before the test.
[0084] In a specific implementation, the optical lens protective coating material is prepared by the de-platinum catalyst and the performance is tested:
[0085] A certain amount of high-concentration platinum catalyst and de-silicone oil were placed in a rotary evaporator, the temperature was set to 95°C, the rotary evaporation program was started and maintained for 6 hours to obtain a de-silicone liquid, and the de-silicone liquid was slowly mixed with the pre-de-silicone treated vinyl silicone oil in a ratio of 1:29 under inert gas protection to obtain a low-concentration platinum catalyst mixed system with zero siloxane content.
[0086] After the treatment, the siloxane content was tested using a precision analytical instrument, and the result showed that the siloxane content was 0;
[0087] Subsequently, 30 g of the de-deoxidized platinum catalyst was placed in a conical flask with a glass cover, placed on a heating platform, and baked at 90° C. for 4 hours. After baking, the surface of the glass cover was observed, and no volatile condensate was visible. The transmittance was tested by a haze meter and was less than 0.5%, indicating that the volatile content of the de-deoxidized platinum catalyst itself was extremely low and met the requirements.
[0088] The platinum removal catalyst and other raw materials are mixed in proportion, and a proper amount of photocuring initiator is added. The prepared coating material is applied to the surface of the optical lens and cured by ultraviolet light.
[0089] The transmittance of the tested coating is as high as over 98% in the visible light range, and after a long period of wet heat aging test, the transmittance changes very little, with the transmittance change rate being less than 0.5%.
[0090] For the volatile content test, an appropriate amount of the finished coating material was put into a conical flask with a glass cover and baked on a heating platform at 180°C for 36 hours. No volatile condensate was visible on the surface of the glass cover, indicating that the optical lens protective coating material will not be atomized or otherwise affect optical properties due to volatiles at high temperatures, demonstrating the effectiveness of the de-platinum catalyst of the present invention in the preparation of optical lens protective coatings.
[0091] From the test results, it can be seen that the platinum-removal catalyst for the silicon-hydrogen structure of the present invention can adjust the mixing ratio of the platinum catalyst and the silicon oil removal according to application requirements to adjust the concentration PPM of platinum, and the preparation process is simple, and it has broad application prospects.
[0092] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.
[0093] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.
[0094] The above is a detailed introduction to the preparation method of a de-platinum catalyst for a silicon-hydrogen structure provided in the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for a person skilled in the art, according to the idea of the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.
Claims
1. A method for preparing a platinum removal catalyst for a silicon-hydrogen structure, characterized in that: Includes steps: The platinum catalyst stock solution and the silicone oil are mixed in a ratio of 1:0.5-2 by mass to obtain a liquid to be evaporated; wherein the platinum content of the platinum catalyst stock solution is 2.5×10 5 -4.0×10 5 ppm; Rotary distilling the liquid to be distilled at a first temperature for a first period of time to obtain a deionized liquid; The de-plating liquid and de-plating vinyl silicone oil are mixed in a ratio of 1:29 to obtain a de-plating platinum catalyst liquid.
2. The preparation method according to claim 1, characterized in that: Also includes: The de-platinum catalyst liquid is subjected to a volatilization measurement; specifically, the de-platinum catalyst liquid is placed on a heating platform, and a watch glass is placed on the mouth of a container of the de-platinum catalyst liquid; Raising the temperature of the heating platform to a second temperature, and baking the de-platinum catalyst liquid for a second time period; The volatility of the de-platinum catalytic solution is determined based on the light transmittance of the watch glass.
3. The preparation method according to claim 2, characterized in that: The second temperature is 90°C.
4. The preparation method according to claim 2, characterized in that: The second duration is 4 hours.
5. The preparation method according to claim 1, characterized in that: The first temperature is 85-95°C.
6. The preparation method according to claim 1, characterized in that: The first duration is 4-6 hours.
7. The preparation method according to claim 1, characterized in that: The vinyl content of the vinyl-free silicone oil is 0.2% to 0.6%.
8. The preparation method according to claim 1, characterized in that: The platinum catalyst stock solution is a Speier catalyst or a Karstedt catalyst.
9. The preparation method according to claim 1, characterized in that: In the step of rotary evaporating the liquid to be evaporated at a first temperature for a first period of time to obtain the desalted liquid, the rotation speed of the rotary evaporator is 10-15 r / min.
10. The preparation method according to claim 1, characterized in that: The viscosity of the silicone oil is 200-1000 mPa.s.