Alkoxy fluorosilicone oil as well as preparation method and application thereof

Abstract

The invention relates to the technical field of synthesis of organic fluorosilicone materials, and particularly discloses alkoxy fluorosilicone oil as well as a preparation method and application thereof. Through the combined action of a chain link A, a chain link B and an end-capping group, when the alkoxy fluorosilicone oil disclosed by the invention is used as a structural control agent in the fluorosilicone rubber, the fluorosilicone rubber has relatively high elongation, so that the defects in related technologies can be fully overcome, and the product performance of the fluorosilicone rubber is favorably improved.

Description

Technical Field

[0001] The present application relates to the technical field of organic fluorosilicone material synthesis, and more specifically, to an alkoxy fluorosilicone oil and a preparation method and application thereof. Background Art

[0002] Fluorosilicone rubber is a high-performance synthetic rubber that combines the advantages of silicone rubber and fluororubber. This material has excellent temperature resistance, chemical corrosion resistance, ozone resistance, weather resistance and good electrical insulation properties. It is widely used in aerospace, automotive industry, medical equipment, wire and cable, seals and chemical processing equipment.

[0003] In the production of fluorosilicone rubber, in order to control the molecular interaction between fluorosilicone raw rubber and filler and extend the storage period of the rubber, it is usually necessary to add a structuring control agent during the mixing process. The structuring control agent can prevent or delay the structuring effect. Its composition is usually an organic silicon compound with an active group. The anti-structuring function is attributed to the condensation reaction between the active group of the structuring control agent and the active hydroxyl group on the surface of white carbon black, which makes it passivated or shielded to achieve the purpose of anti-structuring. The structuring control agent currently used is mainly dihydroxyl fluorosilicone oil, which has the advantages of good anti-structuring performance and transparent mixed rubber.

[0004] Regarding the above-mentioned related technologies, the inventors believe that although the double-terminated hydroxyl fluorosilicone oil can achieve good anti-structural performance, it will also lead to limited elongation of the rubber after vulcanization, making it difficult for fluorosilicone rubber to undergo large-scale tensile deformation, which will affect the product quality of fluorosilicone rubber. Summary of the invention

[0005] In the related art, the double-terminated hydroxyl fluorosilicone oil will lead to limited elongation of the rubber material after vulcanization, affecting the product quality of fluorosilicone rubber. In order to improve this defect, the present application provides an alkoxy fluorosilicone oil and a preparation method and application thereof.

[0006] In the first aspect, the present application provides an alkoxy fluorosilicone oil, which adopts the following technical solution: An alkoxy fluorosilicone oil, the alkoxy fluorosilicone oil having the following structure: R1O[SiMe(CH2CH2CF3)O] n (SiMeR2O) m (SiMeR2)OR1; R1 is an alkyl group, R2 is one of methyl, hydrogen, vinyl, and trifluoropropyl, the value of n is 2-10, the value of m is 2-5, and both m and n are integers.

[0007] By adopting the above technical scheme, the alkoxy fluorosilicone oil of the present application is alkoxy terminated, and is mainly composed of SiMe(CH2CH2CF3)O (referred to as A chain segment, the same below) and SiMeR2O (referred to as B chain segment, the same below). The CH2CH2CF3 group in the A chain segment has a lower surface energy and a larger steric hindrance, which can increase the distance between the molecular chains of fluorosilicone rubber, and enhance the flexibility of the molecular chain of fluorosilicone rubber, making it easier to slip when subjected to force; the B chain segment is combined with the A chain segment to give the alkoxy fluorosilicone oil a suitable molecular weight, and the end-capping group is an alkoxy group with a weaker polarity, thereby reducing the resistance encountered when the molecular chain slips. Through the combined action of the A chain segment, the B chain segment and the end-capping group, the alkoxy fluorosilicone oil of the present application can make the fluorosilicone rubber have a higher elongation when used as a structural control agent in fluorosilicone rubber, which can fully overcome the defects in the relevant technology and help improve the product performance of fluorosilicone rubber. In addition to being used as a structural control agent in fluorosilicone rubber, the alkoxy fluorosilicone oil of the present application also has the general properties of silicone oil and can be used as a lubricant, heat conducting medium, and insulating material, and is not limited to the field of fluorosilicone rubber synthesis.

[0008] In a second aspect, the present application provides a method for preparing an alkoxy fluorosilicone oil, using the following technical solution: A method for preparing an alkoxy fluorosilicone oil comprises the following steps: (1) vacuum dehydration treatment of trifluoropropyl cyclotrisiloxane for standby use; (2) mixing trifluoropropyl cyclotrisiloxane, sulfonic acid resin and alkoxy end-capping agent to obtain a mixture, adding the mixture into a reaction container, and heating the mixture under normal pressure to obtain a crude product; (3) The crude product is filtered, and then dealcoholization and low-boiling-point removal are performed in sequence by water pump, and the alkoxy fluorosilicone oil is obtained after the material is cooled and discharged.

[0009] By adopting the above technical scheme, the present application uses trifluoropropyl cyclotrisiloxane as the main raw material, and causes the trifluoropropyl cyclotrisiloxane to undergo a ring-opening reaction under the catalytic action of a sulfonic acid resin, and forms an A segment, and simultaneously forms a B segment through an alkoxy end-capping agent. After the A segment and the B segment are combined during the reaction, a crude product containing alkoxy fluorosilicone oil can be obtained. Afterwards, the sulfonic acid resin is first filtered and recovered, and then the small molecular alcohols and low-boiling substances with a small molecular weight formed during the reaction are successively removed, and a relatively pure alkoxy fluorosilicone oil can be obtained.

[0010] The method of the present application adopts a synthetic route different from the conventional technology, and does not need to use chlorosilane as a raw material, thus overcoming the defect of producing acidic waste liquid of hydrochloric acid when using chlorosilane as a raw material in the conventional technology. The sulfonic acid resin selected in the present application is solid and easy to recycle after the reaction, thus overcoming the problem that the residual acid waste liquid is difficult to dispose after using an acidic solution as a catalyst in the conventional technology. The method of the present application can fully reduce the generation of acidic by-products and acidic waste liquid, significantly reduce the pollution caused to the environment by by-products and waste, and can fully meet the requirements of green environmental protection.

[0011] Preferably, the alkoxy capping agent has the following structure: MeR2Si(OR1)2; R1 is an alkyl group, and R2 is one of methyl, hydrogen, vinyl, and trifluoropropyl.

[0012] By adopting the above technical solution, the present application defines the structure of the alkoxy end-capping agent. After the alkoxy end-capping agent with the above structure reacts with trifluoropropyl cyclotrisiloxane under the catalysis of sulfonic acid resin, a structure of R1O[SiMe(CH2CH2CF3)O] can be obtained. n (SiMeR2O) m Alkoxy fluorosilicone oil of (SiMeR2)OR1.

[0013] Preferably, the weight of the alkoxy end-capping agent accounts for 25-40% of the total weight of the trifluoropropylcyclotrisiloxane.

[0014] By adopting the above technical solution, the present application optimizes the dosage of the alkoxy end-capping agent, and the preparation of alkoxy fluorosilicone oil can be achieved within the above range. In addition, the alkoxy fluorosilicone oil has a lower viscosity, which helps to fully achieve the anti-structuring effect.

[0015] Preferably, the alkoxy end-capping agent is one of diethoxydimethylsilane, dimethoxymethylhydrogensilane, dimethoxymethylvinylsilane and dimethoxymethyltrifluoropropylsilane.

[0016] By adopting the above technical scheme, any one of diethoxydimethylsilane, dimethoxymethylhydrogensilane, dimethoxymethylvinylsilane and dimethoxymethyltrifluoropropylsilane can be used as an alkoxy end-capping agent, so that the preparation of alkoxy fluorosilicone oil can be achieved.

[0017] Preferably, in step (2) of the method, the amount of sulfonic acid resin used is 5-7% of the total weight of trifluoropropylcyclotrisiloxane.

[0018] By adopting the above technical solution, the present application optimizes the dosage range of the sulfonic acid resin and can realize the preparation of alkoxy fluorosilicone oil.

[0019] Preferably, in step (2) of the method, the amount of sulfonic acid resin used is 5% of the total weight of trifluoropropylcyclotrisiloxane.

[0020] By adopting the above technical scheme, when the amount of sulfonic acid resin catalyst is less than 4% (of the total weight of trifluoropropylcyclotrisiloxane), the yield is low, and there is a large amount of D3F that does not participate in the reaction. With the increase of the amount of sulfonic acid resin catalyst, the yield first shows an upward trend and then gradually tends to balance. With the increase of the amount of sulfonic acid resin catalyst, the ring-opening polymerization reaction rate is significantly improved, and the efficiency of the ring-opening recombination of the reactants is greatly improved, so that the reaction develops in a positive direction. When the amount of sulfonic acid resin catalyst is greater than 5%, the viscosity, yield and ethoxy content of the reaction product are not significantly improved, so from the cost consideration, the optimal amount of sulfonic acid resin is 5%.

[0021] Preferably, in step (2) of the method, the mixture is heated to react at 90-110°C.

[0022] By adopting the above technical solution, the present application optimizes the temperature range for heating the mixture to react, and can achieve the preparation of alkoxy fluorosilicone oil.

[0023] Preferably, in step (2) of the method, the mixture is heated to react at 110°C.

[0024] By adopting the above technical solution, the present application further optimizes the temperature conditions for heating the mixture to react. At 110°C, the yield of alkoxy fluorosilicone oil is relatively high, which can achieve full utilization of the raw materials.

[0025] In a third aspect, the present application provides an application of alkoxy fluorosilicone oil, adopting the following technical solution.

[0026] An application of alkoxy fluorosilicone oil comprises using the alkoxy fluorosilicone oil as a structuring control agent in fluorosilicone rubber.

[0027] By adopting the above technical solution, the addition of alkoxy fluorosilicone oil can significantly increase the elongation of fluorosilicone rubber and can fully improve the oil resistance of fluorosilicone rubber. After adding the alkoxy fluorosilicone oil of the present application, the attenuation of the physical properties of fluorosilicone rubber when immersed in an organic solvent is small, which can effectively improve the durability of fluorosilicone rubber in harsh environments.

[0028] In summary, this application has the following beneficial effects: 1. Through the combined effects of the A chain link, the B chain link and the end-capping group, the alkoxy fluorosilicone oil of the present application, when used as a structuring control agent in fluorosilicone rubber, can enable the fluorosilicone rubber to have a higher elongation, can fully overcome the defects in the relevant technology, and help improve the product performance of fluorosilicone rubber.

[0029] 2. The present application uses trifluoropropyl cyclotrisiloxane as the main raw material, and the trifluoropropyl cyclotrisiloxane undergoes a ring-opening reaction under the catalytic action of a sulfonic acid resin to form an A segment, and at the same time forms a B segment through an alkoxy end-capping agent. After the A segment and the B segment are combined during the reaction, a crude product containing alkoxy fluorosilicone oil can be obtained. Afterwards, the sulfonic acid resin is first filtered and recovered, and then the small molecular alcohols and low-boiling substances with a small molecular weight formed during the reaction are successively removed to obtain a relatively pure alkoxy fluorosilicone oil.

[0030] 3. The method of the present application overcomes the defect of producing acidic waste liquid of hydrochloric acid when using chlorosilane as raw material in the traditional technology. In addition, the sulfonic acid resin selected in the present application is solid and easy to recover after the reaction, which overcomes the problem of difficult disposal of the remaining acid waste liquid after using acid solution as catalyst in the traditional technology. Therefore, it can reduce the generation of acidic by-products and acidic waste liquid, significantly reduce the pollution of the environment caused by by-products and waste, and fully meet the requirements of green environmental protection. 4. The present application applies alkoxy fluorosilicone oil to fluorosilicone rubber. The addition of alkoxy fluorosilicone oil can significantly improve the elongation of fluorosilicone rubber. At the same time, the addition of alkoxy fluorosilicone oil can also fully improve the oil resistance of fluorosilicone rubber. After immersion in organic solvents, neither the tensile strength nor the elongation is easy to show obvious attenuation, which can effectively improve the durability of fluorosilicone rubber in harsh environments. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in combination with the embodiments, preparation examples and comparative examples. The raw materials involved in the present application can be obtained commercially, and the sources of raw materials are as follows: trifluoropropyl cyclotrisiloxane (D3F): purity ≧99.5%, Zhejiang Huanxin Fluoro Material Technology Co., Ltd., diethoxydimethylsilane: purity ≧99.5%, Jiuding Chemical, sulfonic acid resin (ball): Kairui Environmental Protection Technology Co., Ltd., fluorosilicone raw rubber, Shenzhen Guanheng New Material Technology Co., Ltd., butanol, AR, Sinopharm Chemical Reagent Co., Ltd., potassium hydroxide, AR Sinopharm Chemical Reagent Co., Ltd. Example

[0032] Examples 1-5 The following description is given by taking Example 1 as an example.

[0033] Example 1 This embodiment provides an alkoxy fluorosilicone oil having the following structure: R1O[SiMe(CH2CH2CF3)O] n (SiMeR2O) m (SiMeR2)OR1.

[0034] The above silicone oil is a mixture of multiple silicone oil molecules with different numbers of repetitions of A chain segments and B chain segments, wherein R1 is ethyl, R2 is methyl, the value of n is 2-10 (i.e., the maximum number of repetitions of A chain segment in a single alkoxy fluorosilicone oil molecule is 10, and the minimum number is 2), the value of m is 2-5 (i.e., the maximum number of repetitions of B chain segment in a single alkoxy fluorosilicone oil molecule is 5, and the minimum number is 2), and m and n are both integers.

[0035] This embodiment also provides a method for preparing an alkoxy fluorosilicone oil, comprising the following steps: (1) 300 g of trifluoropropylcyclotrisiloxane was added to a 500 mL four-necked flask, dehydrated under vacuum at 50° C. for 1 h, and then heated to 60° C. for later use; (2) trifluoropropyl cyclotrisiloxane, sulfonic acid resin and alkoxy end-capping agent are mixed to obtain a mixture, the mixture is added to a reaction container, and heated at 60° C. for 6 hours under normal pressure to obtain a crude product; in this step, diethoxydimethylsilane is selected as the alkyl end-capping agent; the amount of sulfonic acid resin is 5% of the total weight of trifluoropropyl cyclotrisiloxane, and the weight ratio of trifluoropropyl cyclotrisiloxane to the alkyl end-capping agent is 3:1 (when converted in percentage, the relative amount of alkyl end-capping agent is 25%); (3) the crude product is filtered to remove the sulfonic acid resin, and then water pump dealcoholization is carried out at 100° C. and -100 kPa for 1 hour, and low boiling point removal is carried out at 130° C. and -100 kPa for 3 hours, and the material is discharged after cooling to 50° C. to obtain alkoxy fluorosilicone oil.

[0036] As shown in Table 1, the main difference between Examples 1-5 is that the mixture is heated and reacted under different temperature conditions.

[0037] Table 1 Heating temperature of the mixture sample Heating temperature / ℃ Example 1 60 Example 2 70 Example 3 80 Example 4 90 Example 5 100 Example 6 110 Example 7 120 Example 8 In this embodiment, the weight ratio of trifluoropropyl cyclotrisiloxane to the alkyl capping agent is 3:1, the reaction time is 6 hours, and the reaction temperature is 110° C. The difference between this embodiment and Example 6 is that the percentage of the sulfonic acid resin used in the total weight of trifluoropropyl cyclotrisiloxane (referred to as the sulfonic acid resin percentage) is 3%.

[0038] As shown in Table 2, the difference between Examples 8-12 is that the proportions of sulfonic acid resin are different.

[0039] Table 2 Proportion of sulfonic acid resin sample Sulfonic acid resin ratio / % Example 8 3 Example 9 4 Example 10 5 Embodiment 11 6 Example 12 7 Example 13 The difference between this embodiment and embodiment 6 is that the percentage of the amount of the alkyl end-capping agent used in the total weight of the trifluoropropylcyclotrisiloxane (referred to as the alkyl end-capping agent percentage, accurate to 0.1%, the same below) is 3.2%.

[0040] As shown in Table 3, the difference between Examples 13-19 is that the proportion of the alkyl capping agent is different.

[0041] Table 3 Alkyl end-capping agent ratio sample Alkyl capping agent ratio / % Example 13 3.2 Embodiment 14 6.3 Embodiment 15 14.3 Example 16 21.1 Embodiment 17 25.0 Embodiment 18 33.3 Embodiment 19 40.0 Embodiment 20 The difference between this embodiment and embodiment 13 is that dimethoxymethylvinylsilane is used as the alkyl end-capping agent.

[0042] As shown in Table 4, the difference between Examples 20-26 is that the proportions of the alkyl capping agent are different.

[0043] Table 4 Alkyl end-capping agent ratio Embodiment 27 The difference between this embodiment and embodiment 13 is that dimethoxymethylsilane is used as the alkyl end-capping agent.

[0044] As shown in Table 5, the difference between Examples 27-33 is that the proportion of the alkyl capping agent is different.

[0045] Table 5 Alkyl end-capping agent ratio sample Alkyl capping agent ratio / % Embodiment 27 3.2 Embodiment 28 6.3 Embodiment 29 14.3 Embodiment 30 21.1 Embodiment 31 25.0 Embodiment 32 33.3 Embodiment 33 40.0 Embodiment 34 The difference between this embodiment and embodiment 31 is that dimethoxymethyltrifluoropropylsilane is used as the alkyl end-capping agent.

[0046] Embodiment 35 This embodiment provides an application of an alkoxy fluorosilicone oil, and the alkoxy fluorosilicone oil of Example 17 is used as a structuring control agent in fluorosilicone rubber.

[0047] In this embodiment, the fluorosilicone rubber (mixed rubber) includes the following components: 100g of fluorosilicone raw rubber, 40g of white carbon black, 15g of structural control agent, 0.8g of vulcanizing agent, and 2g of heat-resistant agent. The molecular weight of the fluorosilicone raw rubber is 800000, and the vinyl content is 0.5%; the vulcanizing agent is 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane; and the heat-resistant agent is cerium dioxide.

[0048] The processing flow of fluorosilicone rubber (compound rubber) is as follows: First, 100g of fluorosilicone raw rubber is passed through a double-roll open mill to make the raw rubber uniform, and then 40g of white carbon black and 15g of a structuring control agent are added, and then the materials are passed through the double-roll open mill for 8 times to mix the materials evenly, and then the distance between the two rolls of the double-roll open mill is adjusted to make the thickness of the rubber sheet 2.5mm, and then the rubber is placed in an oven for heat treatment at 190°C for 1.5 hours; after the heat treatment, the rubber is cooled to below 50°C, 2g of a heat-resistant agent and 0.8g of a vulcanizing agent are added, and then the materials are passed through a double-roll open mill for 8 times to mix the materials evenly, and then the rubber sheet is rolled and placed for 12 hours, and then passed through the double-roll open mill for 8 times for re-refining. After the re-refining is completed, it is vulcanized at 175°C for 15 minutes through a flat vulcanizer to obtain fluorosilicone rubber.

[0049] Embodiment 36 The difference between this embodiment and embodiment 35 is that the alkoxy fluorosilicone oil of embodiment 24 is selected as the structuring control agent in the fluorosilicone rubber.

[0050] Embodiment 37 The difference between this embodiment and embodiment 35 is that the alkoxy fluorosilicone oil of embodiment 31 is selected as the structuring control agent in the fluorosilicone rubber.

[0051] Embodiment 38 The difference between this embodiment and embodiment 35 is that the alkoxy fluorosilicone oil of embodiment 34 is selected as the structuring control agent in the fluorosilicone rubber.

[0052] Comparative Example Comparative Example 1 This comparative example provides a hydroxy fluorosilicone oil, which is end-capped with double-terminal hydroxyl groups, has a fluorine-containing group of trifluoropropyl, a viscosity of 120 mPa·s, a pH value of 6.3, a refractive index of 1.3800, and a flash point of ≥260°C.

[0053] Comparative Example 2 The difference between this comparative example and Example 35 is that the structuring control agent is the hydroxy fluorosilicone oil of comparative example 1.

[0054] Comparative Example 3 The difference between this comparative example and comparative example 2 is that the structured control agent is methoxy silicone oil, the viscosity of the methoxy silicone oil is 80 mPa·s, the pH value is 7.6, and the flash point is ≥73°C.

[0055] Performance testing methods 1. Basic properties of hydroxy fluorosilicone oil Test object: Alkoxy fluorosilicone oil of Examples 1-34.

[0056] The test items are as follows: (1) Yield The theoretical yield of alkoxy fluorosilicone oil is calculated according to the following reaction formula (m and n are converted to average values ​​based on measured data): MeR2Si(OR1)2+D3F→R1O[SiMe(CH2CH2CF3)O] n (SiMeR2O) m (SiMeR2)OR1; wherein R1 is an alkyl group, and R2 is one of methyl, hydrogen, vinyl, and trifluoropropyl.

[0057] The total weight of the reaction product remaining after the reaction system was de-low-boiling treated was recorded as the actual yield. The ratio of the actual yield to the theoretical yield was calculated and recorded as the yield. The results are shown in Table 6.

[0058] (2) Viscosity The test method refers to GB / T 6408-2008, and the results are shown in Table 6.

[0059] (3) Refractive index The test method refers to the rotation method in GB / T 10247-1988. The results are shown in Table 6.

[0060] (4) Alkoxy content Potassium hydroxide and butanol are added to the alkoxy fluorosilicone oil sample, and ester exchange is carried out under the action of potassium hydroxide to generate new alkyl alcohols. The alkoxy content can be calculated by gas chromatography (GC) testing (the alkyl group in the alkoxy group here is the alkyl type corresponding to R1 and does not represent any alkyl group). The results are shown in Table 6.

[0061] 2. Testing of conventional properties and oil resistance of fluorosilicone rubber Test objects: fluorosilicone rubber of Examples 35-38, Comparative Examples 2-3, and commercially available fluorosilicone rubber (compared with Example 36, in which the structuring control agent is hydroxy fluorosilicone oil).

[0062] Test method: When testing conventional performance, directly follow the following (1)-(3); when testing oil resistance, refer to the test method in GB / T 1690-2010. After immersing the fluorosilicone rubber in standard simulated liquid C (i.e. fuel C) for 72 hours, perform performance tests on the fluorosilicone rubber according to the following (1)-(3).

[0063] The test items are as follows: (1) Hardness The test method refers to the Shaw A hardness tester in GB / T 531.1-2008. Test methods and test results of conventional properties are shown in Table 7, and test results of oil resistance are shown in Table 8.

[0064] (2) Tensile strength The test method refers to the dumbbell specimen test method in GB / T 528-2009. The test results of conventional properties are shown in Table 7, and the test results of oil resistance are shown in Table 8.

[0065] (3) Elongation The test method refers to GB / T 528-2009. The test results of conventional performance are shown in Table 7, and the test results of oil resistance performance are shown in Table 8.

[0066] Table 6 Yield, viscosity, refractive index and alkoxy content Table 7 Conventional performance test of fluorosilicone rubber sample Shore hardness / degree Tensile strength / MPa Elongation / % Embodiment 35 48 11.3 466 Embodiment 37 48 11.5 471 Embodiment 38 48 11.4 474 Comparative Example 2 48 11.0 400 Comparative Example 3 48 10.2 465 Embodiment 36 59 11.2 364 Commercially available fluorosilicone rubber 59 11.1 302 Table 8 Fluorosilicone rubber oil resistance test sample Shore hardness / degree Tensile strength / MPa Elongation / % Embodiment 35 42 6.8 265 Embodiment 37 41 7.1 269 Embodiment 38 42 7.4 271 Comparative Example 2 41 6.5 260 Comparative Example 3 39 2.7 223 Embodiment 36 52 6.7 221 Commercially available fluorosilicone rubber 50 6.6 209 Combining Examples 35-38 with Comparative Examples 2-3 and Table 7, it can be seen that the elongation of the fluorosilicone rubber of Examples 35, 37, and 38 is significantly higher than that of the fluorosilicone rubber of Comparative Example 2; although Example 36 changes the hardness and elongation to a certain extent due to the participation of vinyl in vulcanization, compared with commercially available fluorosilicone rubber, Example 36 can still have a higher elongation at a similar hardness level. After immersion in fuel C for 72 hours, the residual elongation and tensile strength of the fluorosilicone rubber of Examples 35, 37, and 38 are significantly higher than those of the fluorosilicone rubber of Comparative Example 3, and the elongation measured in Example 36 after immersion in fuel C is also significantly higher than that of commercially available fluorosilicone rubber. The above results show that, when the initial hardness is similar, the fluorosilicone rubber to which the alkoxy fluorosilicone oil of the present application is added as a structuring control agent has relatively good elongation and tensile strength before and after immersion in fuel C, which can effectively improve the application effect of fluorosilicone rubber in harsh environments and fully overcome the defects in the relevant technology.

[0067] It can be seen from Examples 1-7 and Table 6 that as the reaction temperature increases, the yield first shows an upward trend and then suddenly decreases. This may be due to the fact that as the temperature increases, the rate of the ring-opening polymerization reaction is significantly improved, and the end-capping efficiency of diethoxydimethylsilane is greatly improved. This result is supported by the changes in the viscosity and ethoxy content of the product. In addition, when the temperature reaches 120°C, it has exceeded the boiling point of the end-capping agent diethoxydimethylsilane, resulting in a large amount of diethoxydimethylsilane volatilization, resulting in low yield, increased viscosity, and decreased ethoxy content. On the whole, a higher yield of alkoxy fluorosilicone oil can be obtained at a temperature between 90-110°C, and the yield of alkoxy fluorosilicone oil at 110°C is the highest in Examples 1-7, indicating that 110°C is a more suitable temperature.

[0068] It can be seen from Examples 8-12 and Table 6 that when the amount of sulfonic acid resin catalyst is 3%, the yield is low. As the amount of sulfonic acid resin catalyst increases, the yield first shows an upward trend and then gradually tends to balance. This may be due to: as the amount of sulfonic acid resin catalyst increases, the rate of ring-opening polymerization is significantly improved, and the efficiency of ring-opening recombination of reactants is greatly improved, so that the reaction develops in a positive direction. This result is supported by the yield, viscosity change and ethoxy content change of the product. After comprehensively considering the viscosity, yield, ethoxy content and production cost, the optimal amount of sulfonic acid resin catalyst for this reaction is 5%.

[0069] It can be seen from Examples 13-19 and Table 6 that with the increase in the amount of diethoxydimethylsilane, the reaction yield does not change significantly. By adjusting the amount of end-capping agent diethoxydimethylsilane, the viscosity and ethoxy content of the alkoxy fluorosilicone oil can be regulated. Within the range selected in this application, the higher the amount of end-capping agent, the lower the viscosity of the reaction product, and the higher the content of ethoxy in the alkoxy fluorosilicone oil.

[0070] It can be seen from Examples 13-19, 20-26, 27-33 and Table 6 that when the weight of the alkoxy end-capping agent accounts for 25-40% of the total weight of trifluoropropylcyclotrisiloxane, not only can the preparation of alkoxy fluorosilicone oil be achieved, but the alkoxy fluorosilicone oil also has a lower viscosity, which helps to fully achieve the anti-structuring effect. Considering the product performance and yield, it is an ideal choice to select an alkoxy end-capping agent that accounts for 25% of the total weight of trifluoropropylcyclotrisiloxane.

[0071] The above embodiments are merely explanations of the present application and are not limitations of the present application. After reading this specification, those skilled in the art may make modifications to the embodiments of the present application without any creative contribution as needed. However, as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An alkoxy fluorosilicone oil, characterized in that: The alkoxy fluorosilicone oil has the following structure: R1O[SiMe(CH2CH2CF3)O] n (SiMeR2O) m (SiMeR2)OR1; R1 is an alkyl group, R2 is one of methyl, hydrogen, vinyl, and trifluoropropyl, the value of n is 2-10, the value of m is 2-5, and both m and n are integers.

2. The method for preparing an alkoxy fluorosilicone oil according to claim 1, characterized in that: The following steps are involved: (1) performing vacuum dehydration treatment on trifluoropropylcyclotrisiloxane for standby use; (2) mixing trifluoropropyl cyclotrisiloxane, sulfonic acid resin and alkoxy end-capping agent to obtain a mixture, adding the mixture into a reaction container, and heating the mixture under normal pressure to obtain a crude product; (3) The crude product is filtered, and then dealcoholization and low-boiling-point removal are performed in sequence by water pump, and the alkoxy fluorosilicone oil is obtained after cooling and discharging.

3. The method for preparing the alkoxy fluorosilicone oil according to claim 2, characterized in that: The alkoxy end-capping agent has the following structure: MeR2Si(OR1)2; R1 is an alkyl group, and R2 is one of methyl, hydrogen, vinyl, and trifluoropropyl.

4. The method for preparing the alkoxy fluorosilicone oil according to claim 3, characterized in that: The weight of the alkoxy end-capping agent accounts for 25-40% of the total weight of the trifluoropropylcyclotrisiloxane.

5. The method for preparing the alkoxy fluorosilicone oil according to claim 4, characterized in that: The alkoxy end-capping agent is selected from one of diethoxydimethylsilane, dimethoxymethylhydrogensilane, dimethoxymethylvinylsilane and dimethoxymethyltrifluoropropylsilane.

6. The method for preparing the alkoxy fluorosilicone oil according to claim 5, characterized in that: In step (2) of the method, the amount of sulfonic acid resin used is 5-7% of the total weight of trifluoropropylcyclotrisiloxane.

7. The method for preparing the alkoxy fluorosilicone oil according to claim 6, characterized in that: In step (2) of the method, the amount of sulfonic acid resin used is 5% of the total weight of trifluoropropylcyclotrisiloxane.

8. The method for preparing the alkoxy fluorosilicone oil according to claim 2, characterized in that: In step (2) of the method, the mixture is heated to react at 90-110°C.

9. The method for preparing the alkoxy fluorosilicone oil according to claim 8, characterized in that: In step (2) of the method, the mixture is heated to react at 110°C.

10. The use of the alkoxy fluorosilicone oil according to claim 1, characterized in that: The invention comprises using the alkoxy fluorosilicone oil as a structuring control agent in fluorosilicone rubber.

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