High phenyl silicone oil, and preparation method and application thereof

Abstract

The application relates to the field of lubricating oil, discloses high-phenyl silicone oil as well as a preparation method and application thereof, the phenyl content of the high-phenyl silicone oil is greater than or equal to 40 mol %, the kinematic viscosity at 25 DEG C is less than or equal to 1000 mm 2 / s based on the total amount of the high-phenyl silicone oil, and the high-phenyl silicone oil provided by the application has high phenyl content and good fluidity, and due to the increase of the phenyl content, the high-phenyl silicone oil has good radiation resistance, high-temperature resistance and the like, and can be used as an electric insulation, heat transfer and / or pressure transfer medium.

Description

Technical Field

[0001] This invention relates to the field of lubricating oils, specifically to a high-phenyl silicone oil, its preparation method, and its application. Background Technology

[0002] In high-end manufacturing, applications such as electrical insulation, heat transfer, and pressure transmission require high-performance liquid carriers to meet the demands of extreme working environments. High-performance carriers must possess excellent insulation, lubrication, damping, shock absorption, moisture resistance, dust resistance, and resistance to high and low temperatures. Among these, excellent stability, suitable viscosity, and a wide operating temperature range are key performance characteristics. Silicone oil, as a special liquid, features high safety and reliability, good gas evolution properties, excellent dielectric properties, and a wide operating temperature range. It is widely used in transformer filling oils, pressure signal transmission media, and impregnation oils for power capacitors.

[0003] Due to steric hindrance and other reasons, silicone oils with high phenyl content are difficult to synthesize. Therefore, the phenyl content in currently developed silicone oils is often low. Silicone-containing molecules with high phenyl content include silicone oils and small cyclic molecules. The small cyclic molecules exist in cyclic form and are not considered silicone oils. Silicone oils with high phenyl content often have the following problems: ① Very high kinematic viscosity at 25℃, often around 2000 mmHg. 2 / s or more; ② The oil is prone to turbidity due to uneven polymerization process. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of excessive kinematic viscosity or turbidity of silicone oils with high phenyl content at 25°C in existing technologies, and to provide a high-phenyl silicone oil, its preparation method, and its applications. The high-phenyl silicone oil provided by this invention has a phenyl content of over 40 mol% and a kinematic viscosity of no more than 1000 mmHg at 25°C. 2 / s, the oil is clear and transparent.

[0005] To achieve the above objectives, a first aspect of the present invention provides a high-phenyl silicone oil, wherein, based on the total amount of the high-phenyl silicone oil, the phenyl content of the high-phenyl silicone oil is ≥40 mol%, and the kinematic viscosity at 25°C is ≤1000 mmHg. 2 / s.

[0006] The second aspect of the present invention provides a method for preparing high-phenyl silicone oil, wherein the preparation method includes: reacting reactants in the presence of a catalyst to obtain high-phenyl silicone oil, wherein the reactants include octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane and polymethylsiloxane with a degree of polymerization of 10-14, and their mass ratio is 30-40:40-50:10-20.

[0007] A third aspect of the present invention provides a high-phenyl silicone oil prepared by the preparation method described in the second aspect of the present invention, wherein, based on the total amount of the high-phenyl silicone oil, the phenyl content of the high-phenyl silicone oil is ≥40 mol%, and the kinematic viscosity at 25°C is ≤1000 mmHg. 2 / s.

[0008] The fourth aspect of the present invention provides a high-phenyl silicone oil according to the first or third aspect of the present invention, or a high-phenyl silicone oil prepared by the preparation method according to the second aspect of the present invention, for use as electrical insulation, heat transfer and / or pressure transfer.

[0009] This invention, through the optimization of raw material types and their proportions, yields a high-phenyl silicone oil with a phenyl content of not less than 40 mol%, and a kinematic viscosity of ≤1000 mmHg at 25°C. 2 It has good fluidity and the oil is clear and transparent, making up for the shortcomings of existing high-phenyl silicone oils. Detailed Implementation

[0010] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0011] The first aspect of this invention provides a high-phenyl silicone oil, wherein, based on the total amount of the high-phenyl silicone oil, the phenyl content of the high-phenyl silicone oil is ≥40 mol%, and the kinematic viscosity at 25°C is ≤1000 mmHg. 2 / s.

[0012] The high-phenyl silicone oil provided by this invention has a phenyl content ≥40 mol%, specifically ≥43 mol%, 47 mol%, 50 mol%, etc., and a kinematic viscosity ≤1000 mmHg at 25°C. 2 / s, specifically ≤900mm 2 / s, 800mm 2 / s, 700mm 2 / s, 600mm 2 / s, 500mm 2 / s or 400mm 2 / s etc.

[0013] In some embodiments, preferably, the refractive index of the high-phenyl silicone oil at 25°C is ≥1.5. The refractive index is related to the phenyl content; generally, the higher the phenyl content, the higher the refractive index. The high-phenyl silicone oil provided by this invention can have a refractive index of ≥1.5, 1.52, or 1.53 at 25°C, etc.

[0014] In some embodiments, preferably, the kinematic viscosity of the high-phenyl silicone oil at 25°C is ≤750 mmHg. 2 / s.

[0015] In some embodiments, preferably, the flash point of the high-phenyl silicone oil is ≥300°C. The flash point of the high-phenyl silicone oil can be ≥300°C or 305°C, etc.

[0016] In some embodiments, preferably, the high-phenyl silicone oil has a pour point ≤ -20°C. The pour point can be ≤ -20°C, -25°C, or 30°C, etc.

[0017] In some embodiments, preferably, the high-phenyl silicone oil does not gel after being kept at 300°C for 72 hours. The high-phenyl silicone oil provided by the present invention has good thermal stability and does not gel after being kept at 300°C for 72 hours.

[0018] The gelation test is performed as follows: Clean the stainless steel dish (inner diameter 50±1mm, inner height 11±1mm) with petroleum ether with a distillation range of 60-90℃. After cleaning and drying, place the sample into the stainless steel dish, filling it to half its volume. When the oven temperature reaches 280℃, place the stainless steel dish into a stainless steel tray and put both into the oven. When the oven temperature reaches 300℃, start timing and maintain the temperature for 72 hours. Remove the stainless steel dish and gently scratch the sample surface with an iron wire. Determine whether the oil has gelled based on the scratch. If the scratch is oily or pasty, it is considered non-gelling (qualified). If a white scratch appears and the sample surface cracks after cooling to room temperature, it is considered gelled (unqualified).

[0019] The second aspect of the present invention provides a method for preparing high-phenyl silicone oil, wherein the preparation method includes: reacting reactants in the presence of a catalyst to obtain high-phenyl silicone oil, wherein the reactants include octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane and polymethylsiloxane with a degree of polymerization of 10-14, and their mass ratio is 30-40:40-50:10-20.

[0020] The reaction formula for obtaining high-phenyl silicone oil by reacting octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane is as follows:

[0021]

[0022] The mass ratio of the three raw materials can be 30:40:10, 30:40:15, 30:40:20, 30:45:10, 30:50:10, 35:40:10, 40:40:10, 30:40:15, 30:40:20, 35:45:15, 35:50:10, 40:45:15, 40:50:20, etc., or any value between any two sets of values. The method provided by this invention does not require additional accelerators and is more suitable for mass production.

[0023] In some embodiments, preferably, the reaction temperature is 105-115°C and the reaction time is 6-8 hours. The reaction temperature can be any value between any two of 105°C, 110°C, 112°C, and 115°C, and the reaction time can be any value between any two of 6 hours, 6.5 hours, 7 hours, 7.5 hours, and 8 hours.

[0024] In some embodiments, preferably, the catalyst is tetramethylammonium hydroxide.

[0025] In some embodiments, preferably, the amount of catalyst is 0.4-1 wt% based on the total amount of reactants. The amount of catalyst can be any value between any two of the following: 0.4 wt%, 0.6 wt%, 0.8 wt%, and 1 wt%.

[0026] When the reaction temperature is above 120℃, the catalyst decomposes, resulting in an incomplete reaction. Most of the product is in an oligomer state, and the obtained product is turbid and does not meet the requirements. When the reaction temperature is below 95℃, or the amount of catalyst is below 0.2wt%, the reaction time will be far beyond the reasonable range if a completely reacted product is to be obtained, which is not suitable for large-scale production.

[0027] In some embodiments, preferably, the preparation method further includes: decomposing the catalyst at 135-160°C for 1-1.5 hours after the reaction is completed. The temperature for decomposing the catalyst can be any value between any two of 135°C, 145°C, 155°C, and 160°C, and the decomposition time can be any value between any two of 1 hour, 1.2 hours, and 1.5 hours.

[0028] In some embodiments, preferably, the preparation method further includes: after the catalyst is decomposed, adding a filter aid and filtering, wherein the filter aid is preferably activated clay and / or diatomaceous earth. Removing the decomposed catalyst by filtration helps to further improve the quality of the obtained oil.

[0029] In some embodiments, preferably, the preparation method further includes distillation after filtration.

[0030] In some embodiments, preferably, the distillation temperature is 280℃-300℃, the time is 1.5-2.5h, and the pressure is -0.097MPa to -0.099MPa. The purpose of distillation is to remove some light fractions and further improve the quality of the oil. The distillation temperature can be any value between any two of 280℃, 290℃, and 300℃, the time can be any value between any two of 1.5h, 2h, and 205h, and the pressure can be any value between any two of -0.097MPa, -0.098MPa, and -0.099MPa.

[0031] A third aspect of the present invention provides a high-phenyl silicone oil prepared by the preparation method described in the second aspect of the present invention, wherein, based on the total amount of the high-phenyl silicone oil, the phenyl content of the high-phenyl silicone oil is ≥40 mol%, and the kinematic viscosity at 25°C is ≤1000 mmHg. 2 / s.

[0032] In some embodiments, preferably, the kinematic viscosity at 25°C is ≤750 mmHg. 2 / s.

[0033] In some embodiments, preferably, the refractive index of the high-phenyl silicone oil at 25°C is ≥1.5.

[0034] In some embodiments, preferably, the flash point of the high-phenyl silicone oil is ≥300°C.

[0035] In some embodiments, preferably, the high-phenyl silicone oil has a pour point ≤ -20°C.

[0036] In some embodiments, preferably, the high-phenyl silicone oil does not gel after being kept at 300°C for 72 hours.

[0037] The fourth aspect of the present invention provides a high-phenyl silicone oil according to the first or third aspect of the present invention, or a high-phenyl silicone oil prepared by the preparation method according to the second aspect of the present invention, for use as electrical insulation, heat transfer and / or pressure transfer.

[0038] The high-phenyl silicone oil provided by this invention has a high phenyl content, good fluidity, and due to the increased phenyl content, it has good radiation resistance, oxidation resistance, and high temperature resistance, and can be used as an electrical insulation, heat transfer and / or pressure transfer medium.

[0039] According to a particularly preferred embodiment of the present invention, the mass ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane is 35-40:43-45:10-11, wherein the degree of polymerization of polymethylsiloxane is 11-13 and the proportion of tetramethylammonium hydroxide is 0.7-0.9 wt%. The resulting high-phenyl silicone oil can improve both its refractive index and phenyl content, resulting in better performance.

[0040] The present invention will be described in detail below through embodiments.

[0041] Unless otherwise specified, all raw materials used in the following examples and comparative examples are commercially available.

[0042] In the following examples and comparative examples, the appearance was measured visually; kinematic viscosity was measured according to GB / T 265; flash point was measured according to GB / T 3536; pour point was measured according to GB / T 510; acid value was measured according to GB / T 264; refractive index was measured according to GB / T 614; evaporation rate was measured according to SH / T 0337; corrosion was measured according to SH / T 0195; benzene content was measured according to GB / T 43314; and phenyl content was calculated according to the following formula:

[0043] Phenyl content (mol%) = number of moles of phenyl groups bonded to silicon / number of moles of organic groups and hydrogen atoms bonded to silicon;

[0044] Radiation resistance was tested according to the T / CIET 610-2024 method (the viscosity change of the silicone oil during the test shall not exceed 5%).

[0045] The gelation test was conducted using the following method:

[0046] Clean the stainless steel dish (inner diameter 50±1mm, inner height 11±1mm) with petroleum ether with a distillation range of 60-90℃. After cleaning, let it dry. Put the sample into the stainless steel dish, filling it to half its volume. When the oven temperature reaches 280℃, place the stainless steel dish on a stainless steel tray and put both into the oven (without forced air). When the oven temperature reaches 300℃ (allowable temperature deviation within ±2℃), start timing and maintain the temperature for 72 hours. Remove the stainless steel dish and lightly scratch the sample surface with an iron wire. Determine whether the oil has gelled based on the scratch. If the scratch is oily or pasty, it is not gelled (qualified). If a white scratch appears and the sample surface cracks after cooling to room temperature, it is gelled (unqualified).

[0047] Example 1

[0048] The reactants, octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane with a degree of polymerization of 12, were added to a reactor in a ratio of 35:45:10. Then, 0.8 wt% (based on the total amount of reactants) of tetramethylammonium hydroxide catalyst was slowly added. After reacting at 110°C for 7 hours, the temperature was raised to 150°C to decompose the catalyst for 1 hour. Then, 10 wt% of filter aid (based on the total amount of reactants, the filter aid was a 1:1 mixture of activated clay and diatomaceous earth) was added and the residual catalyst was filtered out.

[0049] Then, distillation was carried out for 2 hours under a negative pressure of -0.099 MPa and a temperature of 290°C to remove light fractions, and the finished product, high-phenyl silicone oil, was obtained.

[0050] Example 2

[0051] The procedure was carried out as in Example 1, except that the ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane was 40:45:10.

[0052] Example 3

[0053] The procedure was carried out as in Example 1, except that the ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane was 40:45:20.

[0054] Example 4

[0055] The reaction was carried out in accordance with Example 1, except that the ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane and polymethylsiloxane was 30:50:15, the degree of polymerization of polymethylsiloxane was 10, the amount of catalyst was 0.4 wt%, the reaction temperature was 115°C, and the reaction time was 6 h.

[0056] Example 5

[0057] The reaction was carried out in accordance with Example 1, except that the ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane and polymethylsiloxane was 35:40:15, the degree of polymerization of polymethylsiloxane was 14, the amount of catalyst was 1wt%, the reaction temperature was 105°C, and the reaction time was 8h.

[0058] Comparative Example 1

[0059] The procedure was carried out according to Example 1, except that the mass ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane was 10:45:10.

[0060] Comparative Example 2

[0061] The procedure was carried out according to Example 1, except that the mass ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane was 55:45:15.

[0062] Comparative Example 3

[0063] The method of Example 1 was followed, except that the mass ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane was 35:30:10.

[0064] Comparative Example 4

[0065] The procedure was carried out according to Example 1, except that the mass ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane was 35:65:10.

[0066] Comparative Example 5

[0067] The procedure was carried out according to Example 1, except that the mass ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane was 35:45:5.

[0068] Comparative Example 6

[0069] The method of Example 1 was followed, except that the mass ratio of octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane, and polymethylsiloxane was 35:45:30.

[0070] Comparative Example 7

[0071] The method of Example 1 was followed, except that the degree of polymerization of polymethylsiloxane was 5.

[0072] Comparative Example 8

[0073] The method of Example 1 was followed, except that the degree of polymerization of polymethylsiloxane was 20.

[0074] The silicone oils prepared in Examples 1-5 and Comparative Examples 1-8 were used as samples, and their performance was tested respectively. The results are shown in Table 1.

[0075] Table 1 Test Results

[0076]

[0077] Table 1 (continued)

[0078]

[0079]

[0080] As can be seen from the results in Table 1, the high-phenyl silicone oil prepared by this invention has high phenyl content and refractive index, and its kinematic viscosity at 25°C is less than 1000 mmHg. 2 It does not gel at 300℃ for 72 hours, has a high flash point and a low freezing point, and also has good radiation resistance.

[0081] In addition, the corrosion of the samples in Examples 1-5 of the present invention (T3 copper sheet, 100℃, 3h) was qualified, and the acid value did not exceed 0.01mgKOH / g, and was about 0.05-0.01mgKOH / g.

[0082] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A high-phenyl silicone oil, characterized in that, Based on the total amount of the high-phenyl silicone oil, the phenyl content of the high-phenyl silicone oil is ≥40 mol%, and the kinematic viscosity at 25°C is ≤1000 mmHg. 2 / s.

2. The high-phenyl silicone oil according to claim 1, wherein, The high-phenyl silicone oil has a refractive index of ≥1.5 at 25°C; And / or, the kinematic viscosity of the high-phenyl silicone oil at 25°C is ≤750 mmHg. 2 / s; And / or, the flash point of the high-phenyl silicone oil is ≥300℃; And / or, the pour point of the high-phenyl silicone oil is ≤-20℃; And / or, the high-phenyl silicone oil does not gel after being kept at 300°C for 72 hours.

3. A method for preparing a high-phenyl silicone oil, characterized in that, The preparation method includes: reacting the reactants in the presence of a catalyst to obtain high-phenyl silicone oil, wherein the reactants include octaphenylcyclotetrasiloxane, methylphenyldiethoxysilane and polymethylsiloxane with a degree of polymerization of 10-14, and their mass ratio is 30-40:40-50:10-20.

4. The preparation method according to claim 3, wherein, The reaction is carried out at a temperature of 105-115℃ for 6-8 hours.

5. The preparation method according to claim 3 or 4, wherein, The catalyst is tetramethylammonium hydroxide; And / or, based on the total amount of the reactants, the amount of the catalyst is 0.4-1 wt%.

6. The preparation method according to any one of claims 3-5, wherein, The preparation method further includes: after the reaction is completed, decomposing the catalyst at 135-160℃ for 1-1.5h.

7. The preparation method according to claim 6, wherein, The preparation method further includes: after the catalyst is decomposed, adding a filter aid and filtering, wherein the filter aid is preferably activated clay and / or diatomaceous earth.

8. The preparation method according to claim 7, wherein, The preparation method further includes: distillation after filtration; Preferably, the distillation temperature is 280℃-300℃, the time is 1.5-2.5h, and the pressure is -0.097MPa to -0.099MPa.

9. A high-phenyl silicone oil prepared by the preparation method according to any one of claims 3-8, characterized in that, Based on the total amount of the high-phenyl silicone oil, the phenyl content of the high-phenyl silicone oil is ≥40 mol%, and the kinematic viscosity at 25°C is ≤1000 mmHg. 2 The kinematic viscosity at 25℃ is preferably ≤750 mm² / s. 2 / s; Preferably, the refractive index of the high-phenyl silicone oil at 25°C is ≥1.5; Preferably, the flash point of the high-phenyl silicone oil is ≥300℃; Preferably, the high-phenyl silicone oil has a pour point ≤ -20℃; Preferably, the high-phenyl silicone oil does not gel after being kept at 300°C for 72 hours.

10. The use of a high-phenyl silicone oil according to claim 1, 2 or 9, or a high-phenyl silicone oil prepared by the preparation method according to any one of claims 3-8, for electrical insulation, heat transfer and / or pressure transfer.

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