Method for preparing low-viscosity vinyl fluorine-containing hyperbranched organic silicon resin

Abstract

The invention discloses a method for preparing low-viscosity vinyl fluorine-containing hyperbranched organic silicon resin, and belongs to the technical field of organic polymer materials. The low-viscosity vinyl fluorine-containing hyperbranched organic silicon resin is prepared by taking 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 content of vinyl is not lower than 3 wt%, the content of fluorine is not lower than 15 wt%, and the viscosity is not higher than 1000 mPa.s. The vinyl fluorine-containing hyperbranched organic silicon resin disclosed by the invention is used as a material with excellent characteristics of both vinyl organic silicon resin and a fluorine-containing polymer, the existence of vinyl can be suitable for various reaction conditions, the existence of a fluorine-containing group enables the vinyl fluorine-containing hyperbranched organic silicon resin to have excellent hydrophobic and oleophobic properties, and meanwhile, the fluorine-containing polymer material is relatively small in friction coefficient, so that the vinyl fluorine-containing hyperbranched organic silicon resin can be applied to various reaction conditions. The method has great application potential in the fields of oil-resistant sealing, anti-corrosion coatings, electronic materials, medical apparatuses and instruments and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of organic polymer materials, and more specifically, relates to a method for preparing low-viscosity vinyl fluorine-containing hyperbranched organic silicon resin. Background Art

[0002] The main chain of fluorinated silicone resin is a -Si-O-bond structure. After the polar fluorine atom (such as trifluoropropyl) is introduced into the side chain, a -CH2CH2CF3 structure is formed. Since the polarizability of the F atom is very low, the fluorinated polymer material has good insulation, low dielectric constant and good light transmittance; the bond energy of the C-F bond reaches 485kJ / 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 and strong alkali and be used in a high temperature environment; since the F atom has a strong electron-withdrawing effect and the CF bond has a short bond length, it can form a good shielding effect on the CC bond. Therefore, the fluorinated silicone resin not only retains the high temperature resistance, weather resistance and excellent electrical insulation properties of the silicone resin, but also further enhances its chemical corrosion resistance, low surface energy and oil resistance by introducing the fluorine element.

[0003] Chinese patent CN 118185020A discloses a fluorine-containing silicone resin and its preparation method and application. In this method, fluorine-containing silane, epoxy silane, olefin-containing silane, aromatic ring-containing silane and methyl silane are hydrolyzed and condensed under the action of a catalyst to prepare the 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 terms of oleophobic and hydrophobic properties are not fully utilized.

[0004] Chinese patent CN 102482362A discloses a method for producing a fluorine-containing polymer, which uses fluoroolefin monomers for aqueous 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 complicated, requiring strict control of the reaction environment and pressure.

[0005] Chinese patent CN 117209771A discloses a method for preparing a fluorinated organosilicon polymer and its application. The fluorinated organosilicon polymer is prepared by reacting hydrogenated silicone oil and a fluorinated monomer with a carbon-carbon double bond in the presence of a noble metal catalyst. Although this method shortens the reaction time and improves the yield, the product structure is difficult to control and the batch stability is poor.

[0006] Hyperbranched silicone resin is a new type of silicone resin with a unique highly branched three-dimensional network structure. Compared with linear or slightly branched silicone resins, it has higher thermal stability and chemical stability, and has the advantages of high functionality, low viscosity, good solubility, flexible chain length and low surface free energy. At present, there is still a blank in the relevant articles and patent reports on fluorine-containing hyperbranched silicone resins, but it has broad application prospects. The vinyl fluorine-containing silicone resins synthesized by the prior art have poor reaction activity and are difficult to cure, and cannot be applied on a large scale. Therefore, how to provide a simple, fast, green and environmentally friendly method for preparing high-performance and low-viscosity vinyl fluorine-containing hyperbranched silicone resins is very critical. Summary of the invention

[0007] In view of the above problems existing in the prior art, the technical problem to be solved by the present invention is to provide a method for preparing a low-viscosity vinyl fluorine-containing hyperbranched organosilicon resin, which is prepared by a one-pot method and is simple and easy to operate. Another technical problem to be solved by the present invention is to provide a low-viscosity vinyl fluorine-containing hyperbranched organosilicon resin prepared by the above method, which has low viscosity and is liquid at room temperature, and can be further cured and formed by heating or hydrosilylation at room temperature.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing a low-viscosity vinyl fluorine-containing hyperbranched organosilicon resin comprises taking a vinyl-containing siloxane monomer, an alkyl-containing siloxane monomer and a fluorine-containing siloxane monomer as raw materials, and subjecting the monomers to hydrolysis nucleation, condensation growth, end-capping and purification treatments to prepare the low-viscosity vinyl fluorine-containing hyperbranched organosilicon resin; 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.

[0010] Preferably, the vinyl-containing siloxane monomer is selected from one or more of methylvinyldimethylsilane, vinyldimethylmethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldimethylethoxysilane, tetramethyldivinyldisiloxane, vinyltri(2-methoxyethoxy)silane and vinyltriisopropoxysilane.

[0011] Preferably, the fluorine-containing siloxane monomer is selected from one or more of 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 a low-viscosity vinyl fluorine-containing hyperbranched silicone resin specifically comprises the following steps:

[0014] 1) adding a vinyl-containing siloxane monomer, an alkyl-containing siloxane monomer, a fluorine-containing siloxane monomer and deionized water into a reactor, mixing them, and reacting them at 60-80° C. for 2-6 hours;

[0015] 2) adding vinyl-containing siloxane monomer, alkyl-containing siloxane monomer, fluorine-containing siloxane monomer, solvent and catalyst to the reaction system of step 1), and performing condensation growth reaction at 30-80° C. for 12-16 hours;

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

[0017] 4) adding the solution obtained in step 3) into the reaction system in step 2) and continuing the reaction for 2 to 3 hours; subjecting the solution after the reaction to reduced pressure distillation to obtain a low-viscosity vinyl fluorine-containing hyperbranched silicone resin.

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

[0019] Preferably, in the 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.

[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 water, and tetramethylammonium hydroxide; 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 reduced pressure distillation method is simple reduced pressure distillation or reduced pressure vacuum drying.

[0023] The method for preparing low-viscosity vinyl fluorine-containing hyperbranched organosilicon resin prepares vinyl fluorine-containing hyperbranched organosilicon resin.

[0024] The vinyl fluorine-containing hyperbranched silicone resin has the following structural formula:

[0025]

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

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

[0028] 1) The present invention adopts a "one-pot method" to synthesize vinyl fluorine-containing hyperbranched silicone resin, which is simple and easy to operate and has the conditions for scalability and engineering. It can be mass-produced as a modifier and enhancer for fluorosilicone rubber, fluoroether, and silicone rubber, has good compatibility, and can effectively improve its heat resistance and mechanical properties.

[0029] 2) The vinyl fluorine-containing hyperbranched organosilicon resin synthesized by the present invention has a hyperbranched structure with abundant vinyl functional groups, and can undergo self-polymerization with vinyl-containing polymers, and undergo hydrosilylation with silane-containing polymers. The resin has abundant functional groups, and the dendritic structure can greatly improve the reaction activity, and the curing is simple, and the applicable conditions are relatively wide.

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

[0031] 4) The vinyl fluorine-containing hyperbranched silicone resin prepared by the present invention has excellent oil resistance, solvent resistance and hydrophobic properties by introducing fluorine-containing functional groups, and the intermolecular force is relatively low due to the small radius of the fluorine atom;

[0032] 5) The vinyl fluorine-containing hyperbranched silicone resin prepared by the present invention, as a material having the excellent properties of both vinyl hyperbranched silicone resin and fluorine-containing polymer, has high thermal stability and can be used in environments with high temperature resistance requirements such as aerospace. It can now be applied to oil-resistant seals, fuel tank covers, fuel tank interlayers, etc. in space shuttles; with the continuous improvement of the synthesis process and the 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The actual picture of the vinyl fluorine-containing hyperbranched silicone resin prepared in Examples 1-7, wherein the reference numbers 1-7 are Examples 1-7 respectively;

[0034] Figure 2 This is a physical picture of the vinyl fluorine-containing hyperbranched silicone resin prepared in Example 1-2 after curing;

[0035] Figure 3 The infrared spectra of the vinyl fluorine-containing hyperbranched silicone resin prepared in Examples 1-7;

[0036] Figure 4 This is a thermogravimetric curve of the vinyl fluorine-containing hyperbranched silicone resin prepared in Example 1;

[0037] Figure 5 The DTG curve of the vinyl fluorine-containing hyperbranched silicone resin prepared in Example 1;

[0038] Figure 6 These are water contact angle test graphs of the vinyl fluorine-containing 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 DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described below in conjunction with specific embodiments. In the following examples, unless otherwise specified, the technical means used are conventional means well known to those skilled in the art. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0040] The performance testing method adopted by the present 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 testing was performed using a Tensor II FT-IR spectrometer (Bruker, Germany); liquid samples were smeared on a pressed KBr sample, and the test scanning range was 400-4000 cm -1 ;

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

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

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

[0046] 6. Fluorine content: AVANCE III 400 MHz (Bruker, Germany) was used to perform nuclear magnetic resonance testing to analyze the fluorine content.

[0047] 7. Water contact angle: The water contact angle test was performed using an OSA60 Optical Surface Analyzer water contact angle tester.

[0048] Example 1

[0049] A method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin comprises the following steps:

[0050] 1) Add 22.46 g of vinyldimethylmethoxysilane, 15.55 g of methyltrimethoxysilane and 126.40 g of perfluorododecyltriethoxysilane into a three-necked flask equipped with a stirring and condensation reflux device, and react at 60° C. for 4 h;

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

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

[0053] 4) adding the solution obtained in step 3) to the reaction system of step 2), and continuing the reaction at 80° C. for 2 h; distilling the resin solution after the reaction under reduced pressure at -0.1 MPa and 60° C. to remove the solvent and small molecular monomers, and obtain a vinyl fluorine-containing hyperbranched silicone resin.

[0054] Example 2

[0055] A method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin comprises 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 into a three-necked flask equipped with a stirring and condensing reflux device, and react at 60° C. for 2 h;

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

[0058] 3) In another three-necked flask equipped with a stirring and condensation reflux device, add 48.34 g of methyl (3,3,3-trifluoropropyl) diethoxysilane and 5 mL of acetic acid, and react at 50 ° C for 3 h;

[0059] 4) adding the solution obtained in step 3) to the reaction system of step 2), and continuing the reaction at 80° C. for 2 h; distilling the resin solution after the reaction under reduced pressure at -0.1 MPa and 60° C. to remove the solvent and small molecular monomers, and obtain a vinyl fluorine-containing hyperbranched silicone resin.

[0060] Example 3

[0061] A method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin comprises the following steps:

[0062] 1) Add 31.24 g of vinyldimethylethoxysilane, 16.56 g of dimethyldiethoxysilane and 56.725 g of monofluorotriethoxysilane into a three-necked flask equipped with a stirring and condensation reflux device, and react at 60° C. for 5 h;

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

[0064] 3) In another three-necked flask equipped with a stirring and condensation reflux device, add 52.16 g of dodecafluoroheptylpropylmethyldimethoxysilane and 4 mL of 0.5 mol / L potassium hydroxide, and react at 50° C. for 3 h;

[0065] 4) adding the solution obtained in step 3) to the reaction system of step 2) and continuing the reaction at 80° C. for 2 h; distilling the resin solution after the reaction under reduced pressure at -0.1 MPa and 60° C. to remove the solvent and small molecule monomers to obtain a vinyl fluorine-containing hyperbranched silicone resin.

[0066] Example 4

[0067] A method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin comprises the following steps:

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

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

[0070] 3) In another three-necked flask equipped with a stirring and condensation reflux device, add 46.52 g of methyl (3,3,3-trifluoropropyl) diethoxysilane and 10 mL of ammonium chloride, and react at 60 ° C for 4 hours;

[0071] 4) adding the solution obtained in step 3) into the reaction system of step 2) and continuing the reaction at 70° C. for 3 h; removing the solvent and small molecule monomers from the resin solution after the reaction by vacuum distillation at -0.1 MPa and 60° C. to obtain a vinyl fluorine-containing hyperbranched silicone resin.

[0072] Example 5

[0073] A method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin comprises the following steps:

[0074] 1) Add 24.32 g of vinyl triethoxysilane, 16.50 g of ethyl trimethoxysilane and 76.42 g of pentafluorophenyl propyl trimethoxysilane into a three-necked flask equipped with a stirring and condensation reflux device, and react at 80° C. for 4 h;

[0075] 2) Add 12.24 g of vinyl triethoxysilane, 3.22 g of ethyl trimethoxysilane, 34.56 g of pentafluorophenyl propyl trimethoxysilane, 50 mL of methanol, and 12.5 mL of 0.5 mol / L sodium hydroxide to the reaction system of step 1), and react at 60° C. for 12 h;

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

[0077] 4) adding the solution obtained in step 3) to the reaction system of step 2), and continuing the reaction at 70° C. for 2 h; distilling the resin solution after the reaction under reduced pressure at -0.1 MPa and 60° C. to remove the solvent and small molecule monomers, and obtain a vinyl fluorine-containing hyperbranched silicone resin.

[0078] Example 6

[0079] A method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin comprises the following steps:

[0080] 1) Add 33.24 g of vinyl triisopropoxysilane, 13.55 g of 1,2-bis(trimethoxysilyl)ethane, and 78.94 g of perfluorohexadecyl trimethoxysilane into a three-necked flask equipped with a stirring and condensation reflux device, and react at 80° C. for 5 h;

[0081] 2) Add 16.32 g of vinyl triisopropoxysilane, 6.50 g of ethyl trimethoxysilane, 39.47 g of pentafluorophenyl propyl trimethoxysilane, 60 mL of ethanol, and 8.5 mL of hydrochloric acid to the reaction system of step 1), and react at 80° C. for 14 h;

[0082] 3) In another three-necked flask equipped with a stirring and condensation reflux device, add 34.48 g of methyl (3,3,3-trifluoropropyl) diethoxysilane and 3 mL of hydrochloric acid, and react at 120 ° C for 2 h;

[0083] 4) adding the solution obtained in step 3) to the reaction system of step 2), and continuing the reaction at 80° C. for 2 h; distilling the resin solution after the reaction under reduced pressure at -0.1 MPa and 60° C. to remove the solvent and small molecular monomers, and obtain a vinyl fluorine-containing hyperbranched silicone resin.

[0084] Example 7

[0085] A method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin comprises the following steps:

[0086] 1) Add 29.10 g of vinyl tri(2-methoxyethoxy)silane, 22.31 g of methyl triethoxysilane and 82.11 g of nonafluorohexyl trimethoxysilane into a three-necked flask equipped with a stirring and condensation reflux device, and react at 80° C. for 6 h;

[0087] 2) Add 21.32 g of vinyl tri(2-methoxyethoxy)silane, 14.25 g of isobutyl triethoxysilane, 32.15 g of dodecafluoroheptylpropylmethyldimethoxysilane, 50 mL of propanol, and 10 mL of sulfuric acid to the reaction system of step 1), and react at 70° C. for 16 h;

[0088] 3) In another three-necked flask equipped with a stirring and condensation reflux device, add 29.28 g of dodecafluoroheptylpropylmethyldimethoxysilane and 6 mL of sulfuric acid, and react at 110° C. for 3 h;

[0089] 4) adding the solution obtained in step 3) to the reaction system of step 2), and continuing the reaction at 80° C. for 2 h; distilling the resin solution after the reaction under reduced pressure at -0.1 MPa and 60° C. to remove the solvent and small molecular monomers, and obtain a vinyl fluorine-containing hyperbranched silicone resin.

[0090] Comparative Example 1

[0091] A method for preparing a vinyl fluorine-containing hyperbranched silicone resin comprises the following steps:

[0092] 1) Add 32.11 g of trifluorovinyloxyphenyltrimethoxysilane and 24.32 g of methyltriethoxysilane into a three-necked flask equipped with a stirring and condensation reflux device, and react at 60° C. for 6 h;

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

[0094] 3) In another three-necked flask equipped with a stirring and condensation reflux device, 32.21 g of dodecafluoroheptylpropylmethyldimethoxysilane and 5 mL of sulfuric acid were added, and the mixture was reacted at 110° C. for 3 h;

[0095] 4) adding the solution obtained in step 3) to the reaction system of step 2), and continuing the reaction at 80° C. for 2 h; distilling the resin solution after the reaction under reduced pressure at -0.1 MPa and 60° C. to remove the solvent and small molecular monomers, and obtain a vinyl fluorine-containing hyperbranched silicone resin.

[0096] Comparative Example 2

[0097] A method for preparing a vinyl fluorine-containing hyperbranched silicone resin comprises the following steps:

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

[0099] 2) Add 22.41 g of monomethoxydimethylsilyl chloride, 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) In another three-necked flask equipped with a stirring and condensation reflux device, add 28.42 g of dodecafluoroheptylpropylmethyldimethoxysilane and 6 mL of sulfuric acid, and react at 110° C. for 3 h;

[0101] 4) adding the solution obtained in step 3) to the reaction system of step 2), and continuing the reaction at 70° C. for 2 h; distilling the resin solution after the reaction under reduced pressure at -0.1 MPa and 60° C. to remove the solvent and small molecule monomers, and obtain a vinyl fluorine-containing hyperbranched silicone resin.

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

[0103] Table 1 Viscosity and functional group content of silicone 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 can be seen from Table 1, the vinyl fluorine-containing hyperbranched silicone resin prepared by the present invention has high vinyl content and fluorine content, high reaction activity, low viscosity and high processability.

[0106] Depend on Figure 1 It can be seen that the vinyl fluorine-containing hyperbranched silicone resin prepared in the present invention is in a transparent liquid state and has high transparency.

[0107] Depend on Figure 2 It can be seen that the vinyl fluorine-containing hyperbranched silicone resins prepared in Examples 1-2 of the present invention are poured into a polytetrafluoroethylene mold and cured at 150° C. for 2 h to obtain the following Figure 2 It can be seen that the cured product has high transparency.

[0108] Depend on Figure 3 It can be seen that the vinyl fluorine-containing hyperbranched silicone 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 silicone resin cured product prepared in Example 1 under a nitrogen environment is 400° C., the temperature resistance is good, and the residual weight is high.

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

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

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

[0113] High temperature resistance / ℃ 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 can be seen from Table 2, the vinyl fluorine-containing hyperbranched silicone resin prepared in the present invention is superior to the vinyl fluorine-containing hyperbranched silicone resin prepared in Comparative Examples 1-2 in terms of high temperature resistance and hydrophobicity.

[0115] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin, characterized in that: A low-viscosity vinyl-fluorine-containing hyperbranched silicone resin is prepared by using vinyl-containing siloxane monomers, alkyl-containing siloxane monomers and fluorine-containing siloxane monomers as raw materials through hydrolysis nucleation, condensation growth, end-capping and purification treatments; 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.

2. The method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin according to claim 1, characterized in that: The vinyl-containing siloxane monomer is selected from one or more of methylvinyldimethylsilane, vinyldimethylmethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldimethylethoxysilane, tetramethyldivinyldisiloxane, vinyltri(2-methoxyethoxy)silane, and vinyltriisopropoxysilane.

3. The method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin according to claim 1, characterized in that: The fluorine-containing siloxane monomer is selected from one or more of monofluorotriethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, methyl (3,3,3-trifluoropropyl) diethoxysilane, pentafluorophenylpropyltrimethoxysilane, nonafluorohexyltrimethoxysilane, dodecafluoroheptylpropylmethyldimethoxysilane, perfluorododecyltriethoxysilane, tridecafluorooctyltrimethoxysilane, perfluorohexadecyltrimethoxysilane, and perfluoroeicosyltrimethoxysilane.

4. The method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin according to claim 1, characterized in that: The specific steps include: 1) adding a vinyl-containing siloxane monomer, an alkyl-containing siloxane monomer, a fluorine-containing siloxane monomer and deionized water into a reactor, mixing, and reacting at 60-80° C. for 2-6 hours; 2) adding vinyl-containing siloxane monomer, alkyl-containing siloxane monomer, fluorine-containing siloxane monomer, solvent and catalyst to the reaction system of step 1), and performing condensation growth reaction at 30-80° C. for 12-16 hours; 3) Mix the end-capping agent and the catalyst and react at 50-120° C. for 2-4 hours; 4) adding the solution obtained in step 3) into the reaction system in step 2) and continuing the reaction for 2 to 3 hours; subjecting the solution after the reaction to reduced pressure distillation to obtain a low-viscosity vinyl fluorine-containing hyperbranched silicone resin.

5. The method for preparing a low-viscosity vinyl fluorine-containing hyperbranched organosilicon resin according to claim 4, characterized in that: In the step 1), the molar ratio of the vinyl-containing siloxane monomer, the alkyl-containing siloxane monomer, the fluorine-containing siloxane monomer and the deionized water is 1:0.1-3:0.1-3:0.05-2.

6. The method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin according to claim 4, characterized in that: In the 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.

7. The method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin according to claim 4, characterized in that: In the 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 water, and tetramethylammonium hydroxide; the solvent is one or more of tetrahydrofuran, acetone, dichloromethane, ethyl acetate, toluene, methanol, ethanol, propanol, n-butanol, pentaerythritol, and N-methylpyrrolidone.

8. The method for preparing a low-viscosity vinyl fluorine-containing hyperbranched silicone resin according to claim 4, characterized in that: 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 dodecafluoroheptylpropylmethyl dimethoxysilane; and the catalyst is selected from any one of sulfuric acid, hydrochloric acid, acetic acid, ammonium chloride, potassium hydroxide, and sodium hydroxide.

9. The method for preparing a low-viscosity vinyl fluorine-containing hyperbranched organosilicon resin according to any one of claims 1 to 8, wherein the vinyl fluorine-containing hyperbranched organosilicon resin is prepared.

10. The vinyl fluorine-containing hyperbranched silicone resin according to claim 9, characterized in that: The structural formula is as follows: Wherein, R is selected from methyl, ethyl, propyl, butyl, hexyl or cyclohexyl, and R located at different positions in the structural formula are the same or different; R' is selected from monofluoromethyl, trifluoropropyl, pentafluorophenylpropyl, nonafluorohexyl, dodecafluoroheptyl, perfluorododecyl, tridecafluorooctyl, perfluorohexadecyl or perfluoroeicosyl, and R' located at different positions in the structural formula are the same or different.

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