A method for preparing a low viscosity, ethenyl-containing fluorinated hyperbranched silicone resin

Abstract

The application discloses a method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin and belongs to the technical field of organic polymer materials. The low-viscosity vinyl fluorine-containing hyperbranched silicone resin is prepared from a vinyl-containing siloxane monomer, an alkyl-containing siloxane monomer and a fluorine-containing siloxane monomer as raw materials through hydrolysis nucleation, condensation growth, end capping and purification treatment, wherein the vinyl content is not less than 3 wt%, the fluorine content is not less than 15 wt% and the viscosity is not higher than 1000 mPa.s. The vinyl fluorine-containing hyperbranched silicone resin has excellent properties of both a vinyl silicone resin and a fluorine-containing polymer, the existence of the vinyl group can be suitable for various reaction conditions, the existence of the fluorine-containing group makes the hydrophobic and oleophobic properties excellent, and the friction coefficient of the fluorine-containing polymer material is small, so that the vinyl fluorine-containing hyperbranched silicone resin has great application potential in the fields of oil-resistant sealing, anticorrosion coating, electronic materials, medical devices and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic polymer materials, and more particularly relates to a method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin. BACKGROUND

[0002] The main chain of the fluorine-containing silicone resin is a --Si--O-- bond structure, and after a polar fluorine atom (such as a trifluoropropyl group) is introduced on the side chain, a --CH2CH2CF3 structure is formed. Since the polarizability of the F atom is very low, the fluorine-containing polymer material is good in insulation, low in dielectric constant and good in light transmission; the bond energy of the C-F bond is as high as 485 kJ / mol, and a very high energy is required to break this chemical bond, so the polymer containing the C-F bond can withstand strong acid, strong base and be used in a high-temperature environment; since the F atom has a strong electron-withdrawing effect, and the C-F bond has a short bond length, a good shielding effect can be formed on the C-C bond. Therefore, the fluorine-containing silicone resin not only retains the high-temperature resistance, weather resistance and excellent electrical insulation performance of the silicone resin, but also further enhances its chemical corrosion resistance, low surface energy and oil resistance by introducing fluorine elements.

[0003] Chinese patent CN 118185020A discloses a fluorine-containing silicone resin and a preparation method and application thereof. The method hydrolyzes and condenses fluorine-containing silane, epoxy silane, olefin-containing silane, aromatic ring-containing silane and methyl silane under the action of a catalyst to prepare a fluorine-containing silicone resin, which can be used as a semi-permanent release agent film after curing. However, the fluorine content of the product is not high, and the advantages of the fluorine-containing silicone resin in oil-repellent and water-repellent properties cannot be fully played.

[0004] Chinese patent CN 102482362A discloses a method for manufacturing a fluorine-containing polymer. The method uses a fluorinated olefin monomer to perform water-based dispersion polymerization to synthesize a fluorine-containing polymer. However, the number of particles with surface activity is large and the particle size is small, and the synthesis method is relatively complex and requires strict control of the reaction environment and pressure.

[0005] Chinese patent CN 117209771A discloses a preparation method and application of a fluorine-containing silicone polymer. The fluorine-containing silicone polymer is prepared by reacting hydrogen-containing silicone oil and fluorine-containing monomers with carbon-carbon double bonds in the presence of a noble metal catalyst. Although the method shortens the reaction time and improves the yield, the product structure is not easy to control, and the batch stability is poor.

[0006] Hyperbranched silicone resins are a novel type of silicone resin with a unique, highly branched three-dimensional network structure. Compared to linear or slightly branched silicone resins, they exhibit higher thermal and chemical stability, along with advantages such as high functionality, low viscosity, good solubility, long flexible chains, and low surface free energy. Currently, there is a lack of literature and patent reports on fluorinated hyperbranched silicone resins, but they hold broad application prospects. Existing technologies synthesize vinyl fluorinated silicone resins with poor reactivity and difficult curing, hindering large-scale application. Therefore, providing a simple, rapid, environmentally friendly, high-performance, low-viscosity vinyl fluorinated hyperbranched silicone resin preparation method is crucial. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, the technical problem to be solved by this invention is to provide a method for preparing low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin. This method utilizes a one-pot process to prepare the vinyl-containing fluorinated hyperbranched organosilicon resin, which is simple and easy to operate. Another technical problem to be solved by this invention is to provide a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin obtained by the above method. This resin exhibits low viscosity, is liquid at room temperature, and can be further cured and molded by heating or room-temperature hydrosilylation.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin involves using vinyl-containing siloxane monomers, alkyl-containing siloxane monomers, and fluorinated siloxane monomers as raw materials, followed by hydrolysis nucleation, condensation growth, end-capping, and purification treatment to obtain a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin; wherein the vinyl content is not less than 3 wt%, the fluorine content is not less than 15 wt%, and the viscosity is not higher than 1000 mPa·s.

[0010] Preferably, the vinyl-containing siloxane monomer is selected from one or more of methyl vinyl dimethylsilane, vinyl dimethyl methoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane, vinyl dimethyl ethoxysilane, tetramethyl divinyl disiloxane, vinyl tri(2-methoxyethoxy)silane, and vinyl triisopropoxysilane.

[0011] Preferably, the fluorinated siloxane monomer is selected from one or more of the following: monofluorotriethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, methyl(3,3,3-trifluoropropyl)diethoxysilane, pentafluorophenylpropyltrimethoxysilane, nonafluorohexyltrimethoxysilane, dodecafluoroheptylpropylmethyldimethoxysilane, perfluorododecyltriethoxysilane, tridecafluorooctyltrimethoxysilane, perfluorohexadecyltrimethoxysilane, and perfluoroeicosyltrimethoxysilane.

[0012] The alkyl-containing siloxane monomer is selected from one or more of dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-hexyltriethoxysilane, isobutyltriethoxysilane, cyclohexyltrimethoxysilane, and 1,2-bis(trimethoxysilyl)ethane.

[0013] The method for preparing low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0014] 1) Add vinyl-containing siloxane monomers, alkyl-containing siloxane monomers, fluorine-containing siloxane monomers, and deionized water to a reactor and mix them, then react at 60-80°C for 2-6 hours.

[0015] 2) Add vinyl-containing siloxane monomers, alkyl-containing siloxane monomers, fluorine-containing siloxane monomers, solvents and catalysts to the reaction system of step 1), and perform condensation growth reaction at 30-80°C for 12-16 h.

[0016] 3) Mix the end-capping agent and catalyst, and react at 50–120°C for 2–4 hours;

[0017] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction for 2-3 hours; after the reaction is completed, distill the solution under reduced pressure to obtain a low-viscosity vinyl fluorinated hyperbranched organosilicon resin.

[0018] Preferably, in step 1), the molar ratio of vinyl-containing siloxane monomers, alkyl-containing siloxane monomers, fluorine-containing siloxane monomers to deionized water is 1:0.1-3:0.1-3:0.05-2.

[0019] Preferably, in step 2), the molar ratio of the vinyl-containing siloxane monomer, the alkyl-containing siloxane monomer, the fluorinated siloxane monomer, the solvent, and the catalyst is 1:0.1-3:0.1-3:0.1-3:0.01-1.

[0020] Preferably, in step 2), the catalyst is selected from one or more of sulfuric acid, phosphoric acid, oxalic acid, hydrochloric acid, acetic acid, benzoic acid, acetic acid, ammonium chloride, potassium hydroxide, sodium hydroxide, triethylamine, ammonia, and tetramethylammonium hydroxide; and the solvent is one or more of tetrahydrofuran, acetone, dichloromethane, ethyl acetate, toluene, methanol, ethanol, propanol, n-butanol, pentaerythritol, and N-methylpyrrolidone.

[0021] Preferably, in step 3), the molar ratio of the end-capping agent to the catalyst is 1:0.005-1; the end-capping agent is methyl(3,3,3-trifluoropropyl)diethoxysilane or dodecafluoroheptylpropylmethyldimethoxysilane; and the catalyst is selected from any one of sulfuric acid, hydrochloric acid, acetic acid, ammonium chloride, potassium hydroxide, and sodium hydroxide.

[0022] The vacuum distillation method is either simple vacuum distillation or vacuum drying.

[0023] The method for preparing low-viscosity vinyl fluorinated hyperbranched organosilicon resin yields vinyl fluorinated hyperbranched organosilicon resin.

[0024] The vinyl fluorinated hyperbranched silicone resin has the following structural formula:

[0025]

[0026] Wherein, R is selected from methyl, ethyl, propyl, butyl, hexyl or cyclohexyl, and R in different positions in the structural formula may be the same or different; R' is selected from monofluoromethyl, trifluoropropyl, pentafluorophenylpropyl, nonafluorohexyl, dodecafluoroheptyl, perfluorododecyl, tridecafluorooctyl, perfluorohexadecyl or perfluoroeicosyl, and R' in different positions in the structural formula may be the same or different.

[0027] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0028] 1) This invention uses a "one-pot method" to synthesize vinyl fluorinated hyperbranched organosilicon resin. The operation is simple and easy, and it has the conditions for scale-up and engineering. It can be mass-produced as a modifier and reinforcing agent for fluorosilicone rubber, fluoroether, and silicone rubber. It has advantages such as good compatibility and effective improvement of their heat resistance and mechanical properties.

[0029] 2) The vinyl fluorinated hyperbranched organosilicon resin synthesized in this invention has a hyperbranched structure with abundant vinyl functional groups, which can undergo self-polymerization with vinyl polymers and hydrosilylation with silane polymers. The abundance of functional groups and the dendritic structure can greatly improve the reactivity. It is easy to cure and has a wide range of applicable conditions.

[0030] 3) Compared with other commercially available resins, the vinyl fluorinated hyperbranched organosilicon resin prepared by this invention has a lower viscosity, which improves processability and can increase the amount of reinforcing agent filling in the modified material itself, which is beneficial to processing and production; this invention can quantitatively control the vinyl content (3wt.%~8wt.%), fluorine content (18wt.%~25wt.%) and viscosity (300~1000mPa·s) range of the resin according to different application requirements;

[0031] 4) The vinyl fluorinated hyperbranched organosilicon resin prepared by the present invention has excellent oil resistance, solvent resistance and hydrophobic properties due to the introduction of fluorine functional groups and the low intermolecular forces caused by the small atomic radius of fluorine.

[0032] 5) The vinyl fluorinated hyperbranched organosilicon resin prepared by this invention, as a material that combines the excellent properties of vinyl hyperbranched organosilicon resin and fluoropolymer, has high thermal stability and can be used in environments with high temperature resistance requirements, such as aerospace. It can currently be applied to oil-resistant seals, fuel tank caps, fuel tank partitions, etc. in space shuttles. With the continuous improvement of the synthesis process and in-depth research on performance optimization, it will surely play an important role in more fields and provide strong support for the development of related industries. Attached Figure Description

[0033] Figure 1 The images show the vinyl-containing fluorinated hyperbranched organosilicon resins prepared in Examples 1-7, where numbers 1-7 represent Examples 1-7 respectively.

[0034] Figure 2 These are actual images of the cured vinyl-containing fluorinated hyperbranched silicone resins prepared in Examples 1-2;

[0035] Figure 3 Infrared spectra of the vinyl fluorinated hyperbranched organosilicon resins prepared in Examples 1-7;

[0036] Figure 4 Thermogravimetric curve of the vinyl fluorinated hyperbranched organosilicon resin prepared in Example 1;

[0037] Figure 5 The DTG curve of the vinyl fluorinated hyperbranched organosilicon resin prepared in Example 1;

[0038] Figure 6 The water contact angle test diagrams are for the vinyl fluorinated hyperbranched silicone resins prepared in Examples 1-3; wherein, Figure a is Example 1, Figure b is Example 2, and Figure c is Example 3. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is further described below with reference to specific embodiments. Unless otherwise specified, the technical means used in the following embodiments are all conventional means well known to those skilled in the art. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0040] The performance testing method used in this invention is as follows:

[0041] 1. Resin viscosity: The viscosity of liquid silicone resin was tested using a ROTAVIS rotary viscometer (IKA, Germany).

[0042] 2. Infrared Spectroscopy: Infrared measurements were performed using a Tensor II FT-IR spectrometer (Bruker, Germany); for liquid samples, the sample was applied to a pressed KBr sample plate, and the measurement scanning range was 400–4000 cm⁻¹. -1 ;

[0043] 3. Thermogravimetric analysis test: Thermogravimetric analysis was performed using a STA449F3 thermogravimetric-differential scanning calorimetry analyzer (Netzche GmbH, Germany).

[0044] 4. DTG testing: DTG analysis was performed using a STA449F3 thermogravimetric-differential scanning calorimetry analyzer (Netzche GmbH, Germany).

[0045] 5. Vinyl content: The vinyl content was analyzed by nuclear magnetic resonance testing using an AVANCE III 400MHz (Bruker, Germany).

[0046] 6. Fluorine content: The fluorine content was analyzed by nuclear magnetic resonance testing using an AVANCE III 400MHz (Bruker, Germany).

[0047] 7. Water contact angle: The water contact angle was tested using the OSA60 Optical Surface Analyzer water contact angle tester.

[0048] Example 1

[0049] A method for preparing a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0050] 1) Add 22.46g vinyldimethylmethoxysilane, 15.55g methyltrimethoxysilane, and 126.40g perfluorododecyltriethoxysilane to a three-necked flask equipped with a stirrer and a reflux condenser, and react at 60°C for 4 hours.

[0051] 2) Add 12.87g tetramethyldivinyldisiloxane, 11.22g ethyltriethoxysilane, 55.64g tridecafluorooctyltrimethoxysilane, 80mL acetone, and 12mL acetic acid to the reaction system of step 1), and react at 30℃ for 12h.

[0052] 3) Add 52.33 g of methyl(3,3,3-trifluoropropyl)diethoxysilane and 6 mL of acetic acid to another three-necked flask equipped with a stirrer and a reflux condenser, and react at 50 °C for 2 h;

[0053] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction at 80°C for 2 hours; remove the solvent and small molecule monomers by vacuum distillation at -0.1MPa and 60°C after the reaction is completed to obtain vinyl fluorinated hyperbranched organosilicon resin.

[0054] Example 2

[0055] A method for preparing a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0056] 1) Add 24.24 g of vinyltrimethoxysilane, 20.13 g of n-hexyltriethoxysilane, and 144.45 g of 3,3,3-trifluoropropyltriethoxysilane to a three-necked flask equipped with a stirrer and a reflux condenser, and react at 60 °C for 2 h.

[0057] 2) Add 12.12g vinyltrimethoxysilane, 5.61g n-hexyltriethoxysilane, 72.225g tridecafluorooctyltrimethoxysilane, 70mL dichloromethane, and 8mL acetic acid to the reaction system of step 1), and react at 50℃ for 12h.

[0058] 3) Add 48.34 g of methyl(3,3,3-trifluoropropyl)diethoxysilane and 5 mL of acetic acid to another three-necked flask equipped with a stirrer and a reflux condenser, and react at 50 °C for 3 h;

[0059] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction at 80°C for 2 hours; remove the solvent and small molecule monomers by vacuum distillation at -0.1MPa and 60°C after the reaction is completed to obtain vinyl fluorinated hyperbranched organosilicon resin.

[0060] Example 3

[0061] A method for preparing a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0062] 1) Add 31.24g vinyldimethylethoxysilane, 16.56g dimethyldiethoxysilane, and 56.725g monofluorotriethoxysilane to a three-necked flask equipped with a stirrer and a reflux condenser, and react at 60°C for 5 hours.

[0063] 2) Add 23.56g vinyldimethylethoxysilane, 10.45g dimethyldiethoxysilane, 32.50g monofluorotriethoxysilane, 50mL toluene, and 10mL 0.5mol / L potassium hydroxide to the reaction system of step 1), and react at 60℃ for 12h.

[0064] 3) Add 52.16 g of dodecafluoroheptylpropylmethyldimethoxysilane and 4 mL of 0.5 mol / L potassium hydroxide to another three-necked flask equipped with a stirrer and reflux condenser, and react at 50 °C for 3 h;

[0065] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction at 80°C for 2 hours; remove the solvent and small molecule monomers by vacuum distillation at -0.1MPa and 60°C after the reaction is completed to obtain vinyl fluorinated hyperbranched organosilicon resin.

[0066] Example 4

[0067] A method for preparing a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0068] 1) Add 34.45g of methylvinyldimethoxysilane, 17.63g of dimethyldimethoxysilane, and 54.32g of methyl(3,3,3-trifluoropropyl)diethoxysilane to a three-necked flask equipped with a stirrer and a reflux condenser, and react at 80°C for 4 hours;

[0069] 2) Add 11.48g of methylvinyldimethoxysilane, 5.88g of dimethyldimethoxysilane, 18.10g of methyl(3,3,3-trifluoropropyl)diethoxysilane, 50mL of ethyl acetate, and 15mL of ammonium chloride to the reaction system of step 1), and react at 60℃ for 12h.

[0070] 3) Add 46.52 g of methyl(3,3,3-trifluoropropyl)diethoxysilane and 10 mL of ammonium chloride to another three-necked flask equipped with a stirrer and a reflux condenser, and react at 60 °C for 4 h;

[0071] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction at 70°C for 3 hours; remove the solvent and small molecule monomers by vacuum distillation at -0.1 MPa and 60°C after the reaction is completed to obtain vinyl fluorinated hyperbranched organosilicon resin.

[0072] Example 5

[0073] A method for preparing a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0074] 1) Add 24.32g vinyltriethoxysilane, 16.50g ethyltrimethoxysilane, and 76.42g pentafluorophenylpropyltrimethoxysilane to a three-necked flask equipped with a stirrer and a reflux condenser, and react at 80°C for 4 hours.

[0075] 2) Add 12.24g vinyltriethoxysilane, 3.22g ethyltrimethoxysilane, 34.56g pentafluorophenylpropyltrimethoxysilane, 50mL methanol, and 12.5mL 0.5mol / L sodium hydroxide to the reaction system of step 1), and react at 60℃ for 12h.

[0076] 3) Add 44.20 g of methyl(3,3,3-trifluoropropyl)diethoxysilane and 6 mL of 0.5 mol / L sodium hydroxide to another three-necked flask equipped with a stirrer and reflux condenser, and react at 60 °C for 4 h;

[0077] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction at 70°C for 2 hours; remove the solvent and small molecule monomers by vacuum distillation at -0.1 MPa and 60°C after the reaction is completed to obtain vinyl fluorinated hyperbranched organosilicon resin.

[0078] Example 6

[0079] A method for preparing a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0080] 1) Add 33.24 g of vinyltriisopropoxysilane, 13.55 g of 1,2-bis(trimethoxysilyl)ethane and 78.94 g of perfluorohexadecyltrimethoxysilane to a three-necked flask equipped with a stirrer and a reflux condenser, and react at 80 °C for 5 h.

[0081] 2) Add 16.32g vinyltriisopropoxysilane, 6.50g ethyltrimethoxysilane, 39.47g pentafluorophenylpropyltrimethoxysilane, 60mL ethanol, and 8.5mL hydrochloric acid to the reaction system of step 1), and react at 80℃ for 14h.

[0082] 3) Add 34.48 g of methyl(3,3,3-trifluoropropyl)diethoxysilane and 3 mL of hydrochloric acid to another three-necked flask equipped with a stirrer and a reflux condenser, and react at 120 °C for 2 h;

[0083] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction at 80°C for 2 hours; remove the solvent and small molecule monomers by vacuum distillation at -0.1MPa and 60°C after the reaction is completed to obtain vinyl fluorinated hyperbranched organosilicon resin.

[0084] Example 7

[0085] A method for preparing a low-viscosity vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0086] 1) Add 29.10g vinyltris(2-methoxyethoxy)silane, 22.31g methyltriethoxysilane, and 82.11g nonafluorohexyltrimethoxysilane to a three-necked flask equipped with a stirrer and a reflux condenser, and react at 80°C for 6 hours;

[0087] 2) Add 21.32g vinyltris(2-methoxyethoxy)silane, 14.25g isobutyltriethoxysilane, 32.15g dodecafluoroheptylpropylmethyldimethoxysilane, 50mL propanol, and 10mL sulfuric acid to the reaction system of step 1), and react at 70℃ for 16h.

[0088] 3) Add 29.28 g of dodecafluoroheptylpropylmethyldimethoxysilane and 6 mL of sulfuric acid to another three-necked flask equipped with a stirrer and reflux condenser, and react at 110 °C for 3 h;

[0089] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction at 80°C for 2 hours; remove the solvent and small molecule monomers by vacuum distillation at -0.1MPa and 60°C after the reaction is completed to obtain vinyl fluorinated hyperbranched organosilicon resin.

[0090] Comparative Example 1

[0091] A method for preparing vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0092] 1) Add 32.11 g of trifluoroethyleneoxyphenyltrimethoxysilane and 24.32 g of methyltriethoxysilane to a three-necked flask equipped with a stirrer and a reflux condenser, and react at 60 °C for 6 h.

[0093] 2) Add 12.3g of dimethyldiethoxysilane, 29.12g of dodecafluoroheptylpropylmethyldimethoxysilane, 15mL of propanol and 10mL of sulfuric acid to the reaction system of step 1), and react at 70℃ for 20h.

[0094] 3) Add 32.21 g of dodecafluoroheptylpropylmethyldimethoxysilane and 5 mL of sulfuric acid to another three-necked flask equipped with a stirrer and reflux condenser, and react at 110 °C for 3 h;

[0095] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction at 80°C for 2 hours; remove the solvent and small molecule monomers by vacuum distillation at -0.1MPa and 60°C after the reaction is completed to obtain vinyl fluorinated hyperbranched organosilicon resin.

[0096] Comparative Example 2

[0097] A method for preparing vinyl-containing fluorinated hyperbranched organosilicon resin specifically includes the following steps:

[0098] 1) Add 22.80 g of monomethoxydimethylchlorosilane, 39.21 g of vinyltriisopropoxysilane, and 32.82 g of monofluorotriethoxysilane to a three-necked flask equipped with a stirrer and a reflux condenser, and react at 60 °C for 6 h.

[0099] 2) Add 22.41 g of monomethoxydimethylchlorosilane, 29.45 g of pentafluorophenylpropyltrimethoxysilane, 15 mL of ethanol, and 10 mL of hydrochloric acid to the reaction system of step 1), and react at 70 °C for 15 h.

[0100] 3) Add 28.42 g of dodecafluoroheptylpropylmethyldimethoxysilane and 6 mL of sulfuric acid to another three-necked flask equipped with a stirrer and a reflux condenser, and react at 110 °C for 3 h;

[0101] 4) Add the solution obtained in step 3) to the reaction system in step 2) and continue the reaction at 70°C for 2 hours; remove the solvent and small molecule monomers by vacuum distillation at -0.1 MPa and 60°C after the reaction is completed to obtain vinyl fluorinated hyperbranched organosilicon resin.

[0102] The resin viscosity and vinyl and fluorine content of the samples prepared in Examples 1-7 and Comparative Examples 1-2 were tested, and the test results are shown in Table 1.

[0103] Table 1. Viscosities and functional group contents of the organosilicon resin samples prepared in Examples 1-7 and Comparative Examples 1-2.

[0104] Resin viscosity (mPa-s) Vinyl content (wt%) Fluorine content (wt%) Example 1 390 3.22 20.44 Example 2 520 3.25 22.43 Example 3 970 4.22 18.67 Example 4 410 4.83 21.56 Example 5 480 5.49 24.20 Example 6 530 5.60 19.60 Example 7 360 7.20 18.41 Comparative Example 1 1230 1.22 10.31 Comparative Example 2 1420 2.70 11.65

[0105] As shown in Table 1, the vinyl-containing fluorinated hyperbranched organosilicon resin prepared by this invention has a high vinyl content and fluorine content, high reactivity, low viscosity, and high processability.

[0106] Depend on Figure 1 It is known that the vinyl fluorinated hyperbranched organosilicon resin prepared by the present invention is a transparent liquid with high transparency.

[0107] Depend on Figure 2 It can be seen that by pouring the vinyl-containing fluorinated hyperbranched organosilicon resins prepared in Examples 1-2 of the present invention into polytetrafluoroethylene molds and curing them at 150°C for 2 hours, the following results can be obtained: Figure 2 The cured material shows that it has high transparency.

[0108] Depend on Figure 3 It is known that the vinyl-containing fluorinated hyperbranched organosilicon resin prepared by the present invention contains vinyl and trifluoropropyl target functional groups.

[0109] Depend on Figure 4It can be seen that the initial thermal decomposition temperature of the vinyl fluorine-containing hyperbranched organosilicon resin cured product prepared in Example 1 under nitrogen atmosphere is 400℃, which shows good temperature resistance and high residual weight.

[0110] Depend on Figure 5 It can be seen that the vinyl fluorine-containing hyperbranched organosilicon resin cured product prepared in Example 1 under nitrogen atmosphere only showed a significant weight loss at nearly 500°C.

[0111] Depend on Figure 6 It can be seen that the vinyl fluorine-containing hyperbranched organosilicon resin cured products prepared in Examples 1-3 of the present invention have good hydrophobicity, with a maximum water contact angle of 130.0°.

[0112] Table 2. Test results of the cured hyperbranched silicone resin samples prepared in Examples 1-7 and Comparative Examples 1-2.

[0113] Temperature resistance / °C Water contact angle / ° Example 1 389 128.1 Example 2 340 119.6 Example 3 385 130.0 Example 4 347 124.3 Example 5 360 122.6 Example 6 375 109.7 Example 7 382 120.4 Comparative Example 1 245 98.4 Comparative Example 2 284 101.3

[0114] As shown in Table 2, the vinyl fluorinated hyperbranched organosilicon resin prepared by the present invention has superior performance in terms of high temperature resistance and hydrophobicity compared with the vinyl fluorinated hyperbranched organosilicon resin prepared in Comparative Examples 1-2.

[0115] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing a low viscosity, ethenyl-containing fluorine-containing hyperbranched silicone resin, characterized by, A low-viscosity vinyl fluorine-containing hyperbranched silicone resin is prepared from a vinyl-containing siloxane monomer, an alkyl-containing siloxane monomer, and a fluorine-containing siloxane monomer as raw materials, through hydrolysis nucleation, condensation growth, end-capping, and purification treatment; wherein the vinyl content is not less than 3wt%, the fluorine content is not less than 15wt%, and the viscosity is not higher than 1000mPa·s; specifically comprising the following steps: 1) Mix the vinyl-containing siloxane monomer, the alkyl-containing siloxane monomer, the fluorine-containing siloxane monomer, and deionized water in a reactor and react at 60-80℃ for 2-6h; 2) Add the vinyl-containing siloxane monomer, the alkyl-containing siloxane monomer, the fluorine-containing siloxane monomer, a solvent, and a catalyst to the reaction system of step 1) and mix, and condensation growth reaction at 30-80℃ for 12-16h; 3) Mix the end-capping agent and the catalyst and react at 50-120℃ for 2-4h; 4) Add the solution obtained in step 3) to the reaction system of step 2) and continue to react for 2-3h; after the reaction is completed, the solution is distilled under reduced pressure to obtain the low-viscosity vinyl fluorine-containing hyperbranched silicone resin.

2. The method of producing a low viscosity, ethenyl-containing fluorinated hyperbranched silicone resin according to claim 1, characterized by, The vinyl-containing siloxane monomer is selected from one or more of methyl vinyl dimethyl silane, vinyl dimethyl methoxy silane, vinyl tri-methoxy silane, vinyl tri-ethoxy silane, vinyl dimethyl ethoxy silane, tetramethyl divinyl disiloxane, vinyl tri-(2-methoxyethoxy) silane, and vinyl tri-isopropoxy silane.

3. The method of producing a low viscosity, ethenyl-containing fluorinated hyperbranched silicone resin according to claim 1, characterized by, The fluorine-containing siloxane monomer is selected from one or more of monofluoro tri-ethoxy silane, 3,3,3-trifluoropropyl tri-ethoxy silane, methyl (3,3,3-trifluoropropyl) di-ethoxy silane, pentafluorophenyl propyl trimethoxy silane, nonafluoro hexyl trimethoxy silane, dodecafluoro heptyl propyl methyl dimethoxy silane, perfluorododecyl tri-ethoxy silane, tridecafluorooctyl trimethoxy silane, perfluorohexadecyl trimethoxy silane, and perfluoroeicosyl trimethoxy silane.

4. The method of producing a low viscosity, ethenyl-containing fluorinated hyperbranched silicone resin according to claim 1, characterized by, In step 1), the molar ratio of the vinyl-containing siloxane monomer, the alkyl-containing siloxane monomer, the fluorine-containing siloxane monomer, and deionized water is 1:0.1-3:0.1-3:0.05-2.

5. The method of producing a low viscosity, ethenyl-containing fluorinated hyperbranched silicone resin according to claim 1, characterized by, In step 2), the molar ratio of the vinyl-containing siloxane monomer, the alkyl-containing siloxane monomer, the fluorine-containing siloxane monomer, the solvent, and the catalyst is 1:0.1-3:0.1-3:0.1-3:0.01-1.

6. The method of producing a low viscosity, ethenyl-containing fluorinated hyperbranched silicone resin according to claim 1, characterized by, In step 2), the catalyst is selected from one or more of sulfuric acid, phosphoric acid, oxalic acid, hydrochloric acid, acetic acid, benzoic acid, acetic acid, ammonium chloride, potassium hydroxide, sodium hydroxide, triethylamine, ammonia, and tetramethylammonium hydroxide; and the solvent is one or more of tetrahydrofuran, acetone, dichloromethane, ethyl acetate, toluene, methanol, ethanol, propanol, n-butanol, pentaerythritol, and N-methyl pyrrolidone.

7. The method of producing a low viscosity, ethenyl-containing fluorinated hyperbranched silicone resin according to claim 1, characterized by, In the step 3), the molar ratio of the end-capping agent to the catalyst is 1:0.005-1; the end-capping agent is methyl(3,3,3-trifluoropropyl)diethoxysilane or dodecafluoroheptylpropylmethyldimethoxysilane; and the catalyst is selected from any one of sulfuric acid, hydrochloric acid, acetic acid, ammonium chloride, potassium hydroxide and sodium hydroxide.

8. The ethylene-based fluorine-containing hyperbranched silicone resin prepared by the method of any one of claims 1-7.

9. The ethylene-based fluorinated hyperbranched silicone resin according to claim 8, characterized in that, The structural formula is as follows: ； wherein R is selected from methyl, ethyl, propyl, butyl, hexyl or cyclohexyl, and R in different positions in the structural formula is the same or different; R' is selected from monofluoromethyl, trifluoropropyl, pentafluorophenylpropyl, nonafluorohexyl, dodecafluoroheptyl, perfluorododecyl, tridecafluorooctyl, perfluorohexadecyl or perfluoroeicosyl, and R' in different positions in the structural formula is the same or different.

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