Preparation of thermocuring benzocyclobutenyl MQ silicon resin and application of thermocuring benzocyclobutenyl MQ silicon resin in preparation of glass fiber composite material

Abstract

The invention discloses preparation of thermocuring benzocyclobutenyl MQ silicon resin and application of the thermocuring benzocyclobutenyl MQ silicon resin in preparation of glass fiber composites.The preparation method comprises the steps that an organic silicon source, a solvent, a catalyst and water are stirred to react for 30-90 min at the temperature of 30-50 DEG C, and a mixed solution A is formed; uniformly mixing divinyl siloxane-dibenzocyclobutene and a solvent to form a mixed solution B, adding the mixed solution B into the mixed solution A, heating to 65-80 DEG C, and reacting for 1-3 hours; after the reaction is finished, adding an organic phase for extraction, washing with water for multiple times until the solution is neutral, performing vacuum distillation to remove the solvent, and performing vacuum drying; the thermocuring benzocyclobutenyl MQ silicon resin is obtained. Cured resin formed by thermal crosslinking of the thermocuring benzocyclobutenyl MQ silicon resin has relatively excellent dielectric properties, mechanical properties, heat resistance and chemical stability, and then the cured resin and glass fibers are used for preparing a composite material with the properties of low dielectric, high tensile strength, high bending strength, chemical stability, heat resistance and the like.

Description

Technical Field

[0001] The invention relates to the technical field of MQ silicone resins, and in particular to the preparation of a heat-cured benzocyclobutene-based MQ silicone resin and application thereof in the preparation of a glass fiber composite material. Background Art

[0002] MQ silicone resin is composed of monofunctional structural units (R3SiO 1 / 2 ) and tetrafunctional structural units (R3SiO 4 / 2 ) is a silicone resin formed by covalent bonding. As a new type of silicone polymer material, MQ silicone resin is widely used in liquid silicone rubber reinforcing fillers, LED packaging material reinforcing agents, adhesive tackifiers, electrical insulation layers and silicone pressure-sensitive adhesives. Introducing different organic groups into MQ silicone resin is an important way to obtain MQ silicone resin with better performance and better reinforcement effect; introducing different organic groups is an important way to achieve structural changes in the performance of silicone resins, and by controlling the types of organic groups, MQ silicone resins with different performance requirements can be obtained.

[0003] At present, traditional MQ silicone resins are divided into three types: methyl, vinyl and phenyl. When used as reinforcing agents, the three need to be pretreated in order to better form chemical bonds and cross-link with the matrix material. In the cross-linking process, other small molecules such as silane coupling agents, initiators, and vulcanizers need to be added. Therefore, incomplete removal of small molecules in the subsequent purification process will have a certain impact on its performance and make the process flow cumbersome.

[0004] It has been reported (US Pat. 5882836, 1999) that tetradivinylsiloxane-bisbenzocyclobutene (DVS-BCB for short) can be photo- / thermally cured and can be used for passivation films, photoresists, as insulating layers in the manufacture of electrical devices, as protective films for semiconductor components, and as interlayer dielectrics in multi-chip modules and other multi-layer electronic circuits. The ring-opening polymerization of benzocyclobutene monomers does not require the addition of catalysts and initiators, and no small molecule byproducts are generated during the reaction.

[0005] Therefore, by introducing an organic group having a thermally openable four-membered ring and a double bond, a heat-curing benzocyclobutene-based MQ silicone resin with better performance, simpler cross-linking, better reinforcement effect, and wider application range is obtained.

[0006] In the application of electrical insulation materials, there are not only technical requirements for their strength, toughness, chemical stability, and temperature resistance, but also requirements for their dielectric constant. The composite of glass fiber and traditional MQ silicone resin has deficiencies in production process and performance. Summary of the invention

[0007] The invention prepares MQ silicone resins with different molecular weights by adjusting tetradivinylsiloxane-bisbenzocyclobutene (DVS-BCB for short) as M units and methyl orthosilicate / ethyl orthosilicate as Q units in different proportions under different hydrolysis and condensation conditions to meet technical requirements in different technical fields, and prepares a composite material with low dielectric constant, high tensile strength, high bending strength, high mechanical stability and thermal stability with glass fiber.

[0008] The invention relates to the preparation of a heat-curing benzocyclobutene-based MQ silicone resin and its application in the preparation of glass fiber composite materials. On the one hand, the invention solves the problem that the current traditional MQ silicone resin types do not use the organic group and synthesis method of tetradivinylsiloxane-bisbenzocyclobutene (DVS-BCB for short); on the other hand, the invention fills the gap that heat-curing benzocyclobutene-based MQ silicone resin is rare in the current domestic market; on the other hand, the heat-curing benzocyclobutene-based MQ silicone resin and glass fiber composite materials are prepared with low dielectric constant, high strength and temperature resistance.

[0009] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0010] In order to achieve these purposes and other advantages according to the present invention, a method for preparing a heat-curable benzocyclobutene-based MQ silicone resin is provided, comprising the following steps:

[0011] Step 1: Stir the organosilicon source, solvent, catalyst and water at 30-50° C. for 30-90 minutes to form a mixed solution A;

[0012] Step 2: Evenly mix divinylsiloxane-bisbenzocyclobutene and solvent to form a mixed solution B, add the mixed solution B into the mixed solution A, and heat to 65-80° C. to react for 1-3 hours;

[0013] Step 3: After the reaction is completed, an organic phase is added for extraction and washed with water several times until neutral, the solvent is removed by vacuum distillation, and vacuum drying is performed to obtain a heat-cured benzocyclobutene-based MQ silicone resin.

[0014] Preferably, the heat-curable benzocyclobutenyl MQ silicone resin prepared in step 3 is hydrolyzed and condensed again with other M units with different R groups to remove unreacted alkoxy groups or silanol groups to obtain a heat-curable benzocyclobutenyl MQ silicone resin.

[0015] Preferably, the heat-curable benzocyclobutene-based MQ silicone resin has the structural formula:

[0016]

[0017] Wherein, x=0-50, y=0-50, z=0-50; and R is one of vinyl, alkyl, phenyl, vinylbenzocyclobutenyl or silanealkyl.

[0018] Preferably, the solvents in step 1 and step 2 are polar, weakly polar or non-polar solvents; and the organosilicon source is methyl orthosilicate or ethyl orthosilicate.

[0019] Preferably, the solvent in step 1 and step 2 is one of ethanol, toluene, n-hexane, ethanol, isopropanol or tetrahydrofuran; the catalyst is one or a combination of concentrated hydrochloric acid, concentrated sulfuric acid, glacial acetic acid or fluorine-containing acid;

[0020] Preferably, the mass ratio of the organosilicon source to divinylsiloxane-bisbenzocyclobutene is 1.5-3.5:1; the mass fraction of the solvent in the mixed solution A is 10%-50%; the amount of water used is 10-35% of the total mass of the organosilicon source and divinylsiloxane-bisbenzocyclobutene; the amount of the catalyst added is 10% of the total mass of the organosilicon source and divinylsiloxane-bisbenzocyclobutene. -3 ~5×10 -2 ; The mass fraction of the solvent in the mixed solution B is 10% to 50%.

[0021] Preferably, the extractant used for the organic phase extraction is any one of ethyl acetate, toluene and dichloromethane.

[0022] Preferably, heat-curing benzocyclobutene-based MQ silicone resin and toluene are added to a reactor, ultrapure water, concentrated hydrochloric acid as a catalyst and a capping agent are added, and the mixture is reacted at a constant temperature of 60 to 80° C. for 1 to 3 hours; after the mixture is cooled to room temperature, it is washed with ultrapure water several times to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation and vacuum dried to obtain a heat-curing benzocyclobutene-based MQ silicone resin that is hydrolyzed and condensed again to remove unreacted alkoxy groups or silanol groups; the capping agent is any one of hexamethyldisiloxane, tetramethyldivinyldisiloxane, 4-(ethoxyvinyldimethylsilyl)benzocyclobutene, tetramethyldiphenyldisiloxane, and tetramethyldihydrogendisiloxane.

[0023] The present invention also provides an application of the heat-curing benzocyclobutenyl MQ silicone resin prepared by the preparation method as described above in the preparation of a glass fiber composite material. The heat-curing benzocyclobutenyl MQ silicone resin and a diluent are mixed to obtain a mixed adhesive solution of the resin, and glass fibers are immersed in the mixed adhesive solution and heat-cured to obtain a glass fiber composite material.

[0024] Preferably, based on the total mass of the glass fiber composite material being 100%, the content of the mixed glue is 25-50%, and the content of the glass fiber is 50-75%; the glass fiber is any one of short glass fiber, continuous glass fiber and glass fiber mat.

[0025] The present invention has at least the following beneficial effects:

[0026] (1) The preparation method of the present invention is simple, does not produce by-products, and has a high atomic utilization rate. The process is mature, the number of solvents used in the process is small, the product recovery is easy, and the recovery rate is high. The reaction of the present invention is carried out at 30 to 80°C, with mild conditions and low energy consumption. The present invention has few factors affecting the molecular weight of the product, and the molecular weight is easy to control. The preparation of MQ silicone resins with different molecular weights and the control of the molecular weight are achieved by adjusting the molar ratio of the M unit of divinylsiloxane-bisbenzocyclobutene (abbreviated as DVS-BCB) and the Q unit of tetraethyl orthosilicate (methyl orthosilicate). The system of the present invention has few reaction by-products, a short production cycle, high efficiency, and is fully industrializable. The product of the present invention is completely soluble in polar or weakly polar solvents.

[0027] (2) The cured resin formed by thermal crosslinking of the heat-cured benzocyclobutene-based MQ silicone resin of the present invention has relatively excellent dielectric properties, mechanical properties, heat resistance and chemical stability, and can be prepared with glass fiber to form a composite material with low dielectric properties, high tensile strength, high flexural strength, chemical stability and heat resistance.

[0028] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the infrared FTIR spectrum of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5;

[0030] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5;

[0031] Figure 3 Thermogravimetric curve of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5 after heat curing;

[0032] Figure 4 This is the dielectric constant curve of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5 after heat curing. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0034] It should be understood that terms such as “having”, “including” and “comprising” used herein do not specify the existence or addition of one or more other elements or combinations thereof.

[0035] Embodiment 1:

[0036] In a 50mL reaction bottle, add tetrahydrofuran (13.27g, 63.8mmol), ultrapure water (2.53g, 140.3mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0037] Embodiment 2:

[0038] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (1.61g, 89.3mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0039] Embodiment 3:

[0040] In a 50mL reaction bottle, add tetrahydrofuran (6.63g, 31.9mmol), ultrapure water (1.38g, 76.5mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0041] Embodiment 4:

[0042] In a 50mL reaction bottle, add tetrahydrofuran (5.31g, 25.5mmol), ultrapure water (1.15g, 63.8mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and concentrated hydrochloric acid as a catalyst (1wt%, the percentage refers to the amount of concentrated hydrochloric acid as a catalyst is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)). React at 50°C for 1h, add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol), raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0043] Embodiment 5:

[0044] In a 50mL reaction bottle, add tetrahydrofuran (4.43g, 21.3mmol), ultrapure water (1.15g, 63.8mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed with ultrapure water for several times to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100° C. for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin;

[0045] Figure 1 This is the infrared FTIR spectrum of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5; the molecular structure is determined by the vibration peaks of the molecular absorption groups, and the stretching vibration peaks representing the methyl group and the methylene group connected to silicon are at 2958 cm -1 and 2839cm -1 At 1605cm -1 and 1578cm -1 The peak at 1088cm is caused by the C=C stretching vibration of the BCB six-membered ring. -1 The strong peak at 1254cm is caused by the stretching vibration of Si-O-Si and Si-O-CH3. -1 and 1419cm -1 The peaks at 802cm are composed of as(CH) and s(CH) of Si-CH3. -1 The absorption band at 987cm is due to the stretching vibration of Si-C. -1 and 844cm -1 The absorption band at 691 cm is the bending vibration peak of CH in CH=CH connected to Si. The absorption band of CH out-of-plane bending is located at 691 cm -1 Place.

[0046] Figure 2This is the hydrogen nuclear magnetic resonance spectrum of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5; the hydrogen chemical shift of the benzene ring is above 6.9 ppm; the hydrogen chemical shift of the vinyl group is above 5.6 ppm; the hydrogen chemical shift of the benzo four-membered ring is around 3.2 ppm; the hydrogen chemical shift of the methyl group connected to the silicon-oxygen-silicon bond is around 0.2-0.3 ppm;

[0047] Embodiment 6:

[0048] In a 50mL reaction bottle, add tetrahydrofuran (3.79g, 18.2mmol), ultrapure water (0.88g, 49.2mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0049] Embodiment 7:

[0050] In a 50mL reaction bottle, add tetrahydrofuran (3.32g, 15.9mmol), ultrapure water (0.80g, 44.6mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0051] Embodiment 8:

[0052] In a 50mL reaction bottle, add tetrahydrofuran (2.95g, 14.2mmol), ultrapure water (0.74g, 41.1mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0053] Embodiment 9:

[0054] In a 50mL reaction bottle, add tetrahydrofuran (2.65g, 12.7mmol), ultrapure water (0.69g, 38.3mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0055] Embodiment 10:

[0056] In a 50mL reaction bottle, add tetrahydrofuran (2.41g, 11.6mmol), ultrapure water (0.65g, 36mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0057] Embodiment 11:

[0058] In a 50mL reaction bottle, add tetrahydrofuran (2.21g, 10.6mmol), ultrapure water (0.61g, 34mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0059] Embodiment 12:

[0060] In a 50mL reaction bottle, add tetrahydrofuran (2.04g, 9.8mmol), ultrapure water (0.58g, 32.4mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0061] Embodiment 13:

[0062] In a 50mL reaction bottle, add tetrahydrofuran (1.89g, 9.1mmol), ultrapure water (0.56g, 31mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0063] Embodiment 14:

[0064] In a 50mL reaction bottle, add tetrahydrofuran (1.77g, 8.5mmol), ultrapure water (0.53g, 29.7mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0065] Embodiment 15:

[0066] In a 50mL reaction bottle, add tetrahydrofuran (1.65g, 7.9mmol), ultrapure water (0.51g, 28.7mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0067] Embodiment 16:

[0068] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (1.61g, 89.3mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (2wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 2wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0069] Embodiment 17:

[0070] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (1.61g, 89.3mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (0.5wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 0.5wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0071] Embodiment 18:

[0072] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (1.61g, 89.3mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (3wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 3wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0073] Embodiment 19:

[0074] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (1.61g, 89.3mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (3wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 3wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0075] Embodiment 20:

[0076] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (1.95g, 108.5mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0077] Embodiment 21:

[0078] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (2.29g, 128mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0079] Embodiment 22:

[0080] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (2.64g, 146.7mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0081] Embodiment 23:

[0082] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (2.98g, 165.8mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0083] Embodiment 24:

[0084] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (2.98g, 165.8mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0085] 0.5g of heat-curable benzocyclobutenyl MQ silicone resin and toluene (20wt%, the percentage content refers to the amount of toluene used as 20wt% of the heat-curable benzocyclobutenyl MQ silicone resin) were added to a 50mL reaction bottle, and ultrapure water (0.1g, 5.5mmol), catalyst concentrated hydrochloric acid (1wt%, the percentage content refers to the amount of catalyst concentrated hydrochloric acid used as 1wt% of the total mass of heat-curable benzocyclobutenyl MQ silicone resin and hexamethyldisiloxane) and hexamethyldisiloxane (0.2g, 1mmol) were added to react at 70°C for 2h. After the mixture was cooled to room temperature, it was washed several times with ultrapure water to remove the residual catalyst, and then the organic phase was dried with anhydrous sodium sulfate. After several hours, the sodium sulfate was filtered out, and the organic phase was concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8h to obtain a heat-curable benzocyclobutenyl MQ silicone resin with unreacted silanol and siloxane removed by hydrolysis and condensation again.

[0086] Embodiment 25:

[0087] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (2.98g, 165.8mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0088] 0.5g of heat-curable benzocyclobutenyl MQ silicone resin and toluene (20wt%, the percentage content refers to the amount of toluene used as 20wt% of the heat-curable benzocyclobutenyl MQ silicone resin) were added to a 50mL reaction bottle, and ultrapure water (0.1g, 5.5mmol), catalyst concentrated hydrochloric acid (1wt%, the percentage content refers to the amount of catalyst concentrated hydrochloric acid used as 1wt% of the total mass of heat-curable benzocyclobutenyl MQ silicone resin and hexamethyldisiloxane) and end-capping agent hexamethyldisiloxane (0.2g, 1mmol) were added to react at 70°C for 2h. After the mixture was cooled to room temperature, it was washed with ultrapure water several times to remove the residual catalyst, and then the organic phase was dried with anhydrous sodium sulfate. After several hours, the sodium sulfate was filtered out, and the organic phase was concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8h to obtain a heat-curable benzocyclobutenyl MQ silicone resin with unreacted silanol and siloxane removed by hydrolysis and condensation again.

[0089] Embodiment 26:

[0090] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (2.98g, 165.8mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and end-capping agent divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol), raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0091] 0.5g of heat-curable benzocyclobutenyl MQ silicone resin and toluene (20wt%, the percentage content refers to the amount of toluene used as 20wt% of the heat-curable benzocyclobutenyl MQ silicone resin) were added to a 50mL reaction bottle, and ultrapure water (0.1g, 5.5mmol), catalyst concentrated hydrochloric acid (1wt%, the percentage content refers to the amount of catalyst concentrated hydrochloric acid used as 1wt% of the total mass of heat-curable benzocyclobutenyl MQ silicone resin and hexamethyldisiloxane) and end-capping agent tetramethyldisiloxane (0.13g, 1mmol) were added to react at 70°C for 2h. After the mixture was cooled to room temperature, it was washed with ultrapure water several times to remove the residual catalyst, and then the organic phase was dried with anhydrous sodium sulfate. After several hours, the sodium sulfate was filtered out, and the organic phase was concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8h to obtain a heat-curable benzocyclobutenyl MQ silicone resin with unreacted silanol and siloxane removed by hydrolysis and condensation again.

[0092] Embodiment 27:

[0093] In a 50mL reaction bottle, add tetrahydrofuran (7.96g, 38.3mmol), ultrapure water (2.98g, 165.8mmol), tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of tetrahydrofuran) and catalyst concentrated hydrochloric acid (1wt%, the percentage refers to the amount of catalyst concentrated hydrochloric acid is 1wt% of the amount of tetrahydrofuran and divinylsiloxane-bisbenzocyclobutene (DVS-BCB)) and react at 50°C for 1h. Add tetrahydrofuran (10wt%, the percentage refers to the amount of tetrahydrofuran is 10wt% of the amount of divinylsiloxane-bisbenzocyclobutene) and divinylsiloxane-bisbenzocyclobutene (DVS-BCB) (5g, 12.7mmol) and raise the temperature to 75°C and react at this temperature for 2h. After the mixture is cooled to room temperature, an organic phase is added for extraction and washed several times with ultrapure water to remove the residual catalyst, and then the organic phase is dried with anhydrous sodium sulfate. After several hours, the sodium sulfate is filtered out, and the organic phase is concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8 hours to obtain a thermally cured benzocyclobutene-based MQ silicone resin.

[0094] 0.5g of heat-curable benzocyclobutenyl MQ silicone resin and toluene (20wt%, the percentage content refers to the amount of toluene used as 20wt% of the heat-curable benzocyclobutenyl MQ silicone resin) were added to a 50mL reaction bottle, and ultrapure water (0.1g, 5.5mmol), catalyst concentrated hydrochloric acid (1wt%, the percentage content refers to the amount of catalyst concentrated hydrochloric acid used as 1wt% of the total mass of heat-curable benzocyclobutenyl MQ silicone resin and hexamethyldisiloxane) and end-capping agent dimethylphenylethoxysiloxane (0.18g, 1mmol) were added to react at 70°C for 2h. After the mixture was cooled to room temperature, it was washed with ultrapure water several times to remove the residual catalyst, and then the organic phase was dried with anhydrous sodium sulfate. After several hours, the sodium sulfate was filtered out, and the organic phase was concentrated by rotary evaporation, and finally dried in a vacuum oven at 100°C for 8h to obtain a heat-curable benzocyclobutenyl MQ silicone resin with unreacted silanol and siloxane removed by hydrolysis and condensation again.

[0095] Embodiment 28:

[0096] Use an electronic balance to weigh 10g of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5 and a diluent (80% of the mass of the heat-cured benzocyclobutene-based MQ silicone resin) and mix them evenly to form a glue solution. Spray the release agent on the steel plate and the mold. After spraying, let it stand for 15 minutes and repeat the same method 3 times. Then weigh 30g of chopped glass fibers and spread them on the steel plate coated with the release agent. Then, use a glass rod to drain and impregnate the fiber fabric with the epoxy resin adhesive (i.e., the glue solution formed by the heat-cured benzocyclobutene-based MQ silicone resin and the diluent) so that the resin is evenly covered on the fiber to obtain a glass fiber prepreg. Finally, the prepreg is placed at room temperature for 30 minutes. The mold is placed in an oven and set to 180°C to preheat the mold. After the preheating is completed, the steel plate with the glass fiber prepreg is placed in the mold, and another steel plate of the same size is placed on the glass fiber prepreg. Then close the mold and press gently to fit the two ends of the mold. ) The mold is placed in a hot press. First, without applying pressure, the composite laminate is heated from room temperature (25°C) to 180°C at a heating rate of 2°C / min. After reaching the desired temperature, a pressure of 0.1MPa is applied to the mold, and once the pressure reaches the predetermined value, the temperature and pressure are maintained for 1.5h. To ensure complete curing of the resin, the mold is then heated to 250°C at a rate of 2°C / min and maintained at this temperature for another 2h. Finally, the mold is gradually cooled to room temperature at a cooling rate of 2.5°C / min. The tensile and flexural properties of the composite material were tested to have a tensile strength of 30MPa and a flexural strength of 80MPa.

[0097] Embodiment 29:

[0098] Use an electronic balance to weigh 10g of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5 and a diluent (80% of the mass of the heat-cured benzocyclobutene-based MQ silicone resin) and mix them evenly to form a glue solution. Spray the release agent on the steel plate and the mold. After spraying, let it stand for 15 minutes, and repeat the same method 3 times. Then weigh 23.34g of chopped glass fibers and spread them on the steel plate coated with the release agent. Then, use a glass rod to drain and impregnate the fiber fabric with the epoxy resin adhesive (i.e., the glue solution formed by the heat-cured benzocyclobutene-based MQ silicone resin and the diluent) so that the resin is evenly covered on the fiber to obtain a glass fiber prepreg. Finally, the prepreg is placed at room temperature for 30 minutes. The mold is placed in an oven and set to 180°C to preheat the mold. After the preheating is completed, the steel plate with the glass fiber prepreg is placed in the mold, and another steel plate of the same size is placed on the glass fiber prepreg. Then close the mold and press gently to fit the two ends of the mold. ) The mold is placed in a hot press. First, the composite laminate is heated from room temperature (25°C) to 180°C at a heating rate of 2°C / min without applying pressure. After reaching the desired temperature, a pressure of 0.1MPa is applied to the mold. Once the pressure reaches the predetermined value, both the temperature and pressure are maintained for 1.5h. To ensure complete curing of the resin, the mold is then heated to 250°C at a rate of 2°C / min and maintained at this temperature for another 2h. Finally, the mold is gradually cooled to room temperature at a cooling rate of 2.5°C / min. The tensile and flexural properties of the composite material were tested to have a tensile strength of 40MPa and a flexural strength of 95MPa.

[0099] Embodiment 30:

[0100] Use an electronic balance to weigh 10g of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5 and a diluent (80% of the mass of the heat-cured benzocyclobutene-based MQ silicone resin) and mix them evenly to form a glue solution. Spray the release agent on the steel plate and the mold. After spraying, let it stand for 15 minutes, and repeat the same method 3 times. Then weigh 18.58g of chopped glass fibers and spread them on the steel plate coated with the release agent. Then, use a glass rod to drain and impregnate the fiber fabric with the epoxy resin adhesive (i.e., the glue solution formed by the heat-cured benzocyclobutene-based MQ silicone resin and the diluent) so that the resin is evenly covered on the fiber to obtain a glass fiber prepreg. Finally, the prepreg is placed at room temperature for 30 minutes. The mold is placed in an oven and set to 180°C to preheat the mold. After the preheating is completed, the steel plate with the glass fiber prepreg is placed in the mold, and another steel plate of the same size is placed on the glass fiber prepreg. Then close the mold and press gently to fit the two ends of the mold. ) The mold is placed in a hot press. First, without applying pressure, the composite laminate is heated from room temperature (25°C) to 180°C at a heating rate of 2°C / min. After reaching the desired temperature, a pressure of 0.1MPa is applied to the mold, and once the pressure reaches the predetermined value, the temperature and pressure are maintained for 1.5h. To ensure complete curing of the resin, the mold is then heated to 250°C at a rate of 2°C / min and maintained at this temperature for another 2h. Finally, the mold is gradually cooled to room temperature at a cooling rate of 2.5°C / min. The tensile and flexural properties of the composite material were tested to have a tensile strength of 45MPa and a flexural strength of 110MPa.

[0101] Embodiment 31:

[0102] Use an electronic balance to weigh 10g of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5 and a diluent (80% of the mass of the heat-cured benzocyclobutene-based MQ silicone resin) and mix them evenly to form a glue solution. Spray the release agent on the steel plate and the mold. After spraying, let it stand for 15 minutes, and repeat the same method 3 times. Then weigh 15g of chopped glass fiber and spread it on the steel plate coated with the release agent. Then, use a glass rod to drain the epoxy resin adhesive (i.e., the glue solution formed by the heat-cured benzocyclobutene-based MQ silicone resin and the diluent) and impregnate the fiber fabric so that the resin is evenly covered on the fiber to obtain a glass fiber prepreg. Finally, the prepreg is placed at room temperature for 30 minutes. The mold is placed in an oven and set to 180°C to preheat the mold. After the preheating is completed, the steel plate with the glass fiber prepreg is placed in the mold, and another steel plate of the same size is placed on the glass fiber prepreg. Then close the mold and press gently to fit the two ends of the mold. ) The mold is placed in a hot press. First, the composite laminate is heated from room temperature (25°C) to 180°C at a heating rate of 2°C / min without applying pressure. After reaching the desired temperature, a pressure of 0.1MPa is applied to the mold, and once the pressure reaches the predetermined value, both the temperature and pressure are maintained for 1.5h. To ensure complete curing of the resin, the mold is then heated to 250°C at a rate of 2°C / min and maintained at this temperature for another 2h. Finally, the mold is gradually cooled to room temperature at a cooling rate of 2.5°C / min. The tensile and flexural properties of the composite material were tested to have a tensile strength of 25MPa and a flexural strength of 70MPa.

[0103] Embodiment 32:

[0104] Use an electronic balance to weigh 10g of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5 and a diluent (80% of the mass of the heat-cured benzocyclobutene-based MQ silicone resin) and mix them evenly to form a glue solution. Spray the release agent on the steel plate and the mold. After spraying, let it stand for 15 minutes, and repeat the same method 3 times. Then weigh 12.22g of chopped glass fibers and spread them on the steel plate coated with the release agent. Then, use a glass rod to drain and impregnate the fiber fabric with the epoxy resin adhesive (i.e., the glue solution formed by the heat-cured benzocyclobutene-based MQ silicone resin and the diluent) so that the resin is evenly covered on the fiber to obtain a glass fiber prepreg. Finally, the prepreg is placed at room temperature for 30 minutes. The mold is placed in an oven and set to 180°C to preheat the mold. After the preheating is completed, the steel plate with the glass fiber prepreg is placed in the mold, and another steel plate of the same size is placed on the glass fiber prepreg. Then close the mold and press gently to fit the two ends of the mold. ) The mold is placed in a hot press. First, without applying pressure, the composite laminate is heated from room temperature (25°C) to 180°C at a heating rate of 2°C / min. After reaching the desired temperature, a pressure of 0.1MPa is applied to the mold, and once the pressure reaches the predetermined value, the temperature and pressure are maintained for 1.5h. To ensure complete curing of the resin, the mold is then heated to 250°C at a rate of 2°C / min and maintained at this temperature for another 2h. Finally, the mold is gradually cooled to room temperature at a cooling rate of 2.5°C / min. The tensile and flexural properties of the composite material were tested to have a tensile strength of 35MPa and a flexural strength of 85MPa.

[0105] Embodiment 33:

[0106] Use an electronic balance to weigh 10g of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5 and a diluent (80% of the mass of the heat-cured benzocyclobutene-based MQ silicone resin) and mix them evenly to form a glue solution. Spray the release agent on the steel plate and the mold. After spraying, let it stand for 15 minutes and repeat the same method 3 times. Then weigh 10g of chopped glass fiber and spread it on the steel plate coated with the release agent. Then, use a glass rod to drain the epoxy resin adhesive (i.e., the glue solution formed by the heat-cured benzocyclobutene-based MQ silicone resin and the diluent) and impregnate the fiber fabric so that the resin is evenly covered on the fiber to obtain a glass fiber prepreg. Finally, the prepreg is placed at room temperature for 30 minutes. The mold is placed in an oven and set to 180°C to preheat the mold. After the preheating is completed, the steel plate with the glass fiber prepreg is placed in the mold, and another steel plate of the same size is placed on the glass fiber prepreg. Then close the mold and press gently to fit the two ends of the mold. ) The mold is placed in a hot press. First, the composite laminate is heated from room temperature (25°C) to 180°C at a heating rate of 2°C / min without applying pressure. After reaching the desired temperature, a pressure of 0.1MPa is applied to the mold. Once the pressure reaches the predetermined value, both the temperature and pressure are maintained for 1.5h. To ensure complete curing of the resin, the mold is then heated to 250°C at a rate of 2°C / min and maintained at this temperature for another 2h. Finally, the mold is gradually cooled to room temperature at a cooling rate of 2.5°C / min. The tensile and flexural properties of the composite material are tested to have a tensile strength of 50MPa and a flexural strength of 100MPa.

[0107] Embodiment 34:

[0108] Weigh 0.5 g of the heat-curing benzocyclobutenyl MQ silicone resin prepared in Example 5 and put it into a glass tube with a diameter of 3 mm, and put it into a vacuum heat curing box for a programmed temperature rising process, the temperature rising process is 160°C for 1 h, 180°C for 1 h, 200°C for 2 h, 215°C for 2 h, 230°C for 2 h, 215°C for 1 h, 200°C for 1 h, 180°C for 1 h, 160°C for 1 h, and natural cooling to obtain a cured cylindrical resin with a high cross-linking density.

[0109] Figure 3 This is a thermogravimetric curve of the heat-cured benzocyclobutene-based MQ silicone resin prepared in Example 5 after heat curing; it can be seen that the decomposition temperature of the heat-cured polymer at a weight loss of 5% (T5%) is above 450°C, and it has high thermal stability;

[0110] Figure 4 This is the dielectric constant curve of the thermally cured benzocyclobutene-based MQ silicone resin prepared in Example 5 after thermal curing; it can be seen that the dielectric constant of the thermally cured polymer at 10 MHz is 2.75.

[0111] The catalyst in the above examples 1-27 can be replaced by concentrated sulfuric acid, glacial acetic acid, or fluorine-containing acid, and ethyl orthosilicate can be replaced by methyl orthosilicate.

[0112] The end-capping agent in the above examples 25-27 can be replaced by an alkoxy silicon compound containing an alkyl, phenyl, vinyl, silane, benzocyclobutene or other groups.

[0113] The reaction mechanism of the present invention is:

[0114] Ethyl orthosilicate (methyl orthosilicate) hydrolyzes under acidic conditions to form silanol groups, which condense themselves to form polymers of a certain molecular weight. Divinylsiloxane-bisbenzocyclobutene (DVS-BCB) hydrolyzes under acidic conditions to form silanol groups, which react with silanol groups or siloxanes produced by ethyl orthosilicate to cap and introduce organic groups to form branched benzocyclobutene MQ silicone resins with a certain molecular weight. By adjusting the molar ratio of divinylsiloxane-bisbenzocyclobutene (DVS-BCB) to ethyl orthosilicate (methyl orthosilicate), catalyst content, water consumption, temperature, etc., the molecular weight and condensation degree can be changed to obtain excellent MQ silicone resins.

[0115] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for preparing a heat-curable benzocyclobutene-based MQ silicone resin, characterized in that: The following steps are involved: Step 1: Stir the organosilicon source, solvent, catalyst and water at 30-50° C. for 30-90 minutes to form a mixed solution A; Step 2: Evenly mix divinylsiloxane-bisbenzocyclobutene and solvent to form a mixed solution B, add the mixed solution B into the mixed solution A, and heat to 65-80° C. to react for 1-3 hours; Step 3: After the reaction is completed, an organic phase is added for extraction and washed with water several times until neutral, the solvent is removed by vacuum distillation, and vacuum drying is performed to obtain a heat-cured benzocyclobutene-based MQ silicone resin.

2. The method for preparing the heat-curable benzocyclobutene-based MQ silicone resin according to claim 1, characterized in that: The heat-curable benzocyclobutenyl MQ silicone resin prepared in step 3 is hydrolyzed and condensed again with other M units with different R groups to remove unreacted alkoxy groups or silanol groups, thereby obtaining a heat-curable benzocyclobutenyl MQ silicone resin.

3. The method for preparing the heat-curable benzocyclobutene-based MQ silicone resin according to claim 2, characterized in that: The structural formula of the heat-curable benzocyclobutene-based MQ silicone resin is: Wherein, x=0-50, y=0-50, z=0-50; and R is one of vinyl, alkyl, phenyl, vinylbenzocyclobutenyl or silanealkyl.

4. The method for preparing the heat-curable benzocyclobutene-based MQ silicone resin according to claim 1, characterized in that: The solvents in step 1 and step 2 are polar, weakly polar or non-polar solvents; the organic silicon source is methyl orthosilicate or ethyl orthosilicate.

5. The method for preparing the heat-curable benzocyclobutene-based MQ silicone resin according to claim 1, characterized in that: The solvents in step 1 and step 2 are one of ethanol, toluene, n-hexane, ethanol, isopropanol or tetrahydrofuran; the catalyst is one of concentrated hydrochloric acid, concentrated sulfuric acid, glacial acetic acid or fluorine-containing acid or a combination of several thereof.

6. The method for preparing the heat-curable benzocyclobutene-based MQ silicone resin according to claim 1, characterized in that: The mass ratio of the organosilicon source to divinylsiloxane-bisbenzocyclobutene is 1.5-3.5:1; the mass fraction of the solvent in the mixed solution A is 10%-50%; the amount of water used is 10-35% of the total mass of the organosilicon source and divinylsiloxane-bisbenzocyclobutene; the amount of the catalyst added is 10% of the total mass of the organosilicon source and divinylsiloxane-bisbenzocyclobutene. -3 ~5×10 -2 ; The mass fraction of the solvent in the mixed solution B is 10% to 50%.

7. The method for preparing the heat-curable benzocyclobutene-based MQ silicone resin according to claim 1, characterized in that: The extractant used for the organic phase extraction is any one of ethyl acetate, toluene and dichloromethane.

8. The method for preparing the heat-curable benzocyclobutene-based MQ silicone resin according to claim 2, characterized in that: Add heat-curing benzocyclobutene-based MQ silicone resin and toluene into a reactor, add ultrapure water, catalyst concentrated hydrochloric acid and a capping agent, and react at a constant temperature of 60-80°C for 1-3 hours; after the mixture is cooled to room temperature, wash it with ultrapure water several times to remove the residual catalyst, and then dry the organic phase with anhydrous sodium sulfate. After several hours, filter out the sodium sulfate, concentrate the organic phase by rotary evaporation, and vacuum dry it to obtain a heat-curing benzocyclobutene-based MQ silicone resin that is hydrolyzed and condensed again to remove unreacted alkoxy groups or silanol groups; the capping agent is any one of hexamethyldisiloxane, tetramethyldivinyldisiloxane, 4-(ethoxyvinyldimethylsilyl)benzocyclobutene, tetramethyldiphenyldisiloxane, and tetramethyldihydrodisiloxane.

9. Use of a heat-cured benzocyclobutene-based MQ silicone resin prepared by the preparation method according to any one of claims 1 to 8 in the preparation of glass fiber composite materials, characterized in that: The heat-curable benzocyclobutene-based MQ silicone resin and a diluent are mixed to obtain a mixed adhesive solution of resins, the glass fiber is immersed in the mixed adhesive solution, and heat-cured to obtain a glass fiber composite material.

10. The use according to claim 9, characterized in that Taking the total mass of the glass fiber composite material as 100%, the content of the mixed glue is 25-50%, and the content of the glass fiber is 50-75%; the glass fiber is any one of short glass fiber, continuous glass fiber and glass fiber felt cloth.

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