Preparation method of hydrogen-containing MQ silicon resin

Abstract

The invention discloses a preparation method of hydrogen-containing MQ silicon resin, which comprises the following steps: adding ethyl silicate and 3-chloropropyltrichlorosilane into a mixed solvent, uniformly stirring, dropwise adding distilled water, carrying out low-temperature ultrasonic treatment, and standing to obtain a mixed solution; the preparation method comprises the following steps: adding methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane into diethyl ether, uniformly stirring to form a homogeneous dispersion liquid, then adding a water-containing diethyl ether liquid, and carrying out low-temperature ultrasonic treatment to obtain a precursor liquid; adding hydrochloric acid into the mixed solution to adjust the pH value, then quickly adding the precursor solution, and carrying out depressurization stirring to obtain a reaction solution; and carrying out pH neutralization and reduced pressure distillation on the reaction liquid, then adding an extraction agent for multiple times of extraction, and carrying out reduced pressure distillation on the extraction liquid to obtain the hydrogen-containing MQ silicon resin. According to the invention, the problem of less activity exposure caused by compact structure of hydrogen-containing MQ silicon resin is solved, chloropropyl of 3-chloropropyltrichlorosilane is used as an extension chain, not only can the chloropropyl be converted into hydroxyl in a water-containing environment, but also the exposure of active groups is improved due to structural gaps caused by the chain length of 3-chloropropyltrichlorosilane.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to a method for preparing hydrogen-containing MQ silicone resin. Background Art

[0002] Silicone resin is a thermosetting polysiloxane system with a highly cross-linked structure. It uses silicone as raw material and undergoes hydrolysis, polycondensation and rearrangement to obtain a resin with active groups directly linked to silicon atoms. This type of resin has good heat resistance, weather resistance, electrical insulation, chemical resistance, hydrophobicity and flame retardancy, and also has a large number of active groups that can react with other resins and has a wide range of applications.

[0003] Hydrogenated MQ silicone resin is a type of silicone resin, which has highly reactive silicon-hydrogen bonds and silicon-oxygen structures on the surface, and can form chain reactions with vinyl, hydroxyl and other groups to obtain silicone resins with various functional group activities. The current preparation method of hydrogenated MQ silicone resin is based on the co-hydrolysis and condensation of silane, but MQ resin is a numerical material of silicon-oxygen-silicon system formed based on silicon hydroxyl groups, and its own molecular structure is relatively tight, which has the problem of difficult dispersion, resulting in a decrease in the amount of silicon-hydrogen bonds on the surface of hydrogenated MQ silicone resin, which brings processing problems. Summary of the invention

[0004] In view of the problems in the prior art, the present invention provides a method for preparing a hydrogen-containing MQ silicone resin, which solves the problem that the hydrogen-containing MQ silicone resin has a compact structure resulting in less active exposure. The chloropropyl group of 3-chloropropyltrichlorosilane is used as an extension chain, which is not only converted into a hydroxyl group in an aqueous environment, but also the structural gaps brought about by the chain length itself improve the exposure of the active group.

[0005] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0006] A method for preparing hydrogen-containing MQ silicone resin comprises the following steps:

[0007] Step 1, adding ethyl silicate and 3-chloropropyltrichlorosilane to a mixed solvent and stirring evenly, then dropping distilled water and performing low-temperature ultrasound for 20-30 minutes, and standing to obtain a mixed solution, wherein the molar ratio of ethyl silicate to 3-chloropropyltrichlorosilane is 2-3:1, the mixed solvent is a mixed solvent of ether and ethanol, and the volume ratio of ether to ethanol is 1:5-6, the stirring speed for uniform stirring is 100-300r / min, the concentration of ethyl silicate in the mixed solvent is 300-400g / L, the amount of distilled water added is 1-2% of the mixed solvent, and the dropping speed is 1-2mL / min, the temperature of the low-temperature ultrasound is 5-10°C, and the ultrasound The frequency is 70-90kHz, and the standing temperature is 25-30°C; this step utilizes the solubility of ethyl silicate and 3-chloropropyltrichlorosilane in ether and ethanol to form a well-mixed homogeneous dispersion, and then during the process of dripping distilled water, the distilled water is quickly dispersed in ethanol, which can directly act on ethyl silicate and 3-chloropropyltrichlorosilane, resulting in in-situ hydrolysis of ethyl silicate and 3-chloropropyltrichlorosilane to obtain tetrahydroxysilicic acid and bis(3-hydroxypropyl)dihydroxysilane; low-temperature ultrasound and dripping can accelerate the rapid dispersion of distilled water in the mixed solvent, and the ether will be removed during standing to obtain an ethanol solution of tetrahydroxysilicic acid and bis(3-hydroxypropyl)dihydroxysilane;

[0008] Step 2, adding methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane to ether and stirring evenly to form a homogeneous dispersion, then adding aqueous ether liquid and performing low-temperature ultrasound for 20-30 minutes to obtain a precursor solution, wherein the molar ratio of the methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane is 2-3:2-3:1, the concentration of the methylchlorosilane in ether is 200-300g / L, the stirring speed for uniform stirring is 300-500r / min, the volume ratio of the aqueous ether liquid to the ether is 2-3:1, and the ultrasonic frequency of the low-temperature ultrasound is 70-90kHz, temperature is 5-10°C; this step utilizes the solubility of methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane in ether to form a homogeneous mixed solution, and then adds the aqueous ether solution to the homogeneous dispersion, the ether in the dispersion is expanded, and at the same time, the water vapor in the aqueous ether solution directly contacts with methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane to achieve the effect of in-situ hydrolysis, methylhydroxysilane, dimethylhydroxysilane and trimethylhydroxysilane are obtained, and a homogeneous dispersion is formed in low-temperature ultrasound to achieve a uniform distribution effect;

[0009] Step 3, adding hydrochloric acid to the mixed solution to adjust the pH to 5-6, then quickly adding the precursor solution, and obtaining a reaction solution by reducing pressure and stirring; the mass concentration of the hydrochloric acid is 10-20%, and the M / Q value in the reaction solution is 0.8-0.9; the adding time of the precursor solution is 3-5min, the pressure of the reduced pressure stirring is 80-90% of the atmospheric pressure, and the temperature is 20-25°C; this step uses ethanol in the mixed solution as a dissolving liquid, which has good solubility in hydrochloric acid and forms an acidic environment, and then the ether in the precursor solution forms excellent mutual solubility with ethanol to form a homogeneous dispersion, and the ether is quickly converted into steam and removed by the synergistic effect of reduced pressure stirring and the volatility of ether, and recovered by cooling to obtain a reaction solution with ethanol water as the solvent;

[0010] Step 4, neutralize the reaction solution with pH, ​​and distill under reduced pressure for 10-20min, then add an extractant for multiple extractions, and obtain hydrogen-containing MQ silicone resin by reducing the pressure of the extract. The pH neutralization uses a sodium hydroxide solution with a pH of 9-10, the temperature of the reduced pressure distilled water is 60-70°C, and the pressure is 70-80% of the atmospheric pressure, the extractant uses a mixed solution of toluene and ether, and the volume ratio of toluene to ether is 2:2-3, the pressure of the reduced pressure is 80-90% of the atmospheric pressure, and the temperature is 40-60°C; this step uses sodium hydroxide to neutralize the hydrochloric acid in the reaction solution, and converts ethanol into steam in the reduced pressure distillation for removal, and then uses the extractant for multiple extractions to obtain an extract with toluene as a solution, and finally uses the volatility of toluene and ether themselves to form a solvent for removal, thereby obtaining a hydrogen-containing MQ silicone resin, and the ether in the extractant can be obtained by reducing pressure and stirring in step 3, and the ether is converted into steam during reduced pressure and recovered after cooling.

[0011] Among them, ether has very poor solubility in water and belongs to a slightly soluble system. Therefore, the distilled water content in aqueous ether is extremely low and difficult to quantify. Therefore, the aqueous ether here adopts saturated aqueous ether liquid, and the preparation method of the saturated aqueous ether liquid includes the following steps: a1, placing ether in a sealed heating kettle and heating it at a constant temperature to form an ether gas-liquid mixture, and the temperature of the constant temperature heating is 45-50°C; a2, using nitrogen as a purge gas to purge the heating kettle at a uniform speed, and then passing the purge gas into low-temperature distilled water, and standing to obtain a layered liquid, the temperature of the nitrogen is 40-50°C, the flow rate of the purge gas is 5-10mL / min, the temperature of the low-temperature distilled water is 5-10°C; the standing temperature is 0-5°C; this step utilizes the method of nitrogen purge The ether vapor is taken away by the formula, and a mixed gas of nitrogen and ether vapor is used as a purge tail gas to enter the low-temperature distilled water. The ether is quickly cooled in the distilled water and converted into a liquid state. The slight solubility of the ether in distilled water and the low density of the ether ensure that the ether gradually rises to the surface of the distilled water to form a layered structure. The ether here is obtained by rising from the distilled water, carrying distilled water molecules, and is located on the surface of the distilled water to form an ether liquid; therefore, distilled water is dissolved in the ether layer, and the distilled water is in a saturated state; a3, the layered liquid is allowed to stand at a low temperature for 20-30 minutes, and then the ether layer is extracted and stored at a low temperature to obtain an aqueous ether liquid; the aqueous ether liquid prepared by the above method has a relatively stable water content, which is all in a saturated state, and the method is simple and feasible without the need for large-scale equipment.

[0012] It can be seen from the above description that the present invention has the following advantages:

[0013] 1. The present invention solves the problem that the tight structure of hydrogenated MQ silicone resin leads to less active exposure. The chloropropyl group of 3-chloropropyltrichlorosilane is used as an extension chain, which is not only converted into a hydroxyl group in an aqueous environment, but also the structural gaps brought by its own chain length improve the exposure of the active group.

[0014] 2. The present invention uses ether as an auxiliary solvent, which not only has good solubility for ethyl silicate and 3-chloropropyltrichlorosilane, but also can dissolve methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane, thereby forming a multi-angle concentration change and even accelerating the extraction speed during extraction.

[0015] 3. The present invention adopts methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane as monosubstituted materials to achieve the addition of silicon-hydrogen bonds, and in-situ hydrolysis based on ether can not only achieve the dispersibility of methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane, but also the ultrasonic hydrogen chloride has an acidifying effect, thereby increasing the acid content of the entire precursor solution. DETAILED DESCRIPTION

[0016] The present invention is described in detail with reference to the embodiments, but no limitation is imposed on the claims of the present invention.

[0017] Example 1

[0018] A method for preparing hydrogen-containing MQ silicone resin comprises the following steps:

[0019] Step 1, adding ethyl silicate and 3-chloropropyltrichlorosilane to a mixed solvent and stirring evenly, then dropping distilled water and performing low-temperature ultrasound for 20 minutes, and standing to obtain a mixed solution, wherein the molar ratio of ethyl silicate to 3-chloropropyltrichlorosilane is 2:1, the mixed solvent is a mixed solvent of ether and ethanol, and the volume ratio of ether to ethanol is 1:5, the stirring speed for stirring evenly is 100 r / min, the concentration of ethyl silicate in the mixed solvent is 300 g / L, the amount of distilled water added is 1% of the mixed solvent, and the dropping speed is 1 mL / min, the temperature of the low-temperature ultrasound is 5°C, the ultrasound frequency is 70 kHz, and the standing temperature is 25°C;

[0020] Step 2, adding methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane to diethyl ether and stirring evenly to form a homogeneous dispersion, then adding aqueous diethyl ether liquid and performing low-temperature ultrasound for 20 minutes to obtain a precursor solution, wherein the molar ratio of the methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane is 2:2:1, the concentration of the methylchlorosilane in diethyl ether is 200g / L, the stirring speed for uniform stirring is 300r / min, the volume ratio of the aqueous diethyl ether liquid to the diethyl ether is 2:1, the ultrasonic frequency of the low-temperature ultrasound is 70kHz, and the temperature is 5°C;

[0021] Step 3, adding hydrochloric acid to the mixed solution to adjust the pH to 5, then quickly adding the precursor solution, and obtaining a reaction solution by reducing pressure and stirring; the mass concentration of the hydrochloric acid is 10%, and the M / Q value in the reaction solution is 0.8; the adding time of the precursor solution is 3 minutes, the pressure of the reduced pressure stirring is 80% of the atmospheric pressure, and the temperature is 20°C;

[0022] Step 4, neutralize the reaction solution with pH, ​​and distill under reduced pressure for 10 minutes, then add an extractant for multiple extractions, and reduce the pressure of the extract to obtain a hydrogen-containing MQ silicone resin. The pH neutralization uses a sodium hydroxide solution with a pH of 9, the temperature of the reduced pressure distilled water is 60° C., and the pressure is 70% of the atmospheric pressure. The extractant uses a mixed solution of toluene and ether, and the volume ratio of toluene to ether is 1:1. The pressure of the reduced pressure is 80% of the atmospheric pressure and the temperature is 40° C. The ether in the extractant can be recovered by the reduced pressure stirring in step 3, and the ether is converted into steam during the reduced pressure and recovered after cooling.

[0023] The aqueous ether adopts a saturated aqueous ether liquid, and the preparation method of the saturated aqueous ether liquid comprises the following steps: a1, placing the ether in a sealed heating kettle and heating it at a constant temperature to form an ether gas-liquid mixture, and the temperature of the constant temperature heating is 45°C; a2, using nitrogen as a purge gas to purge the heating kettle at a uniform speed, and then passing the purge gas into low-temperature distilled water, and letting it stand to obtain a layered liquid, the temperature of the nitrogen is 40°C, the flow rate of the purge gas is 5mL / min, and the temperature of the low-temperature distilled water is 5°C; the standing temperature is 0°C; a3, letting the layered liquid stand at a low temperature for 20 minutes, and then extracting the ether layer and storing it at a low temperature to obtain an aqueous ether liquid.

[0024] Example 2

[0025] A method for preparing hydrogen-containing MQ silicone resin comprises the following steps:

[0026] Step 1, adding ethyl silicate and 3-chloropropyltrichlorosilane to a mixed solvent and stirring evenly, then dropping distilled water and performing low-temperature ultrasound for 30 minutes, and standing to obtain a mixed solution, wherein the molar ratio of ethyl silicate to 3-chloropropyltrichlorosilane is 3:1, the mixed solvent is a mixed solvent of ether and ethanol, and the volume ratio of ether to ethanol is 1:6, the stirring speed for stirring evenly is 300r / min, the concentration of ethyl silicate in the mixed solvent is 400g / L, the amount of distilled water added is 2% of the mixed solvent, and the dropping speed is 2mL / min, the temperature of the low-temperature ultrasound is 10°C, the ultrasound frequency is 90kHz, and the standing temperature is 30°C;

[0027] Step 2, adding methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane to diethyl ether and stirring evenly to form a homogeneous dispersion, then adding aqueous diethyl ether liquid and performing low-temperature ultrasound for 30 minutes to obtain a precursor solution, wherein the molar ratio of the methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane is 3:3:1, the concentration of the methylchlorosilane in diethyl ether is 300g / L, the stirring speed for uniform stirring is 500r / min, the volume ratio of the aqueous diethyl ether liquid to the diethyl ether is 3:1, the ultrasonic frequency of the low-temperature ultrasound is 90kHz, and the temperature is 10°C;

[0028] Step 3, adding hydrochloric acid to the mixed solution to adjust the pH to 6, then quickly adding the precursor solution, and obtaining a reaction solution by reducing pressure and stirring; the mass concentration of the hydrochloric acid is 20%, and the M / Q value in the reaction solution is 0.9; the adding time of the precursor solution is 5 minutes, the pressure of the reduced pressure stirring is 90% of the atmospheric pressure, and the temperature is 25°C;

[0029] Step 4, neutralize the reaction solution with pH, ​​and distill under reduced pressure for 20 minutes, then add an extractant for multiple extractions, and reduce the pressure of the extract to obtain a hydrogen-containing MQ silicone resin. The pH neutralization uses a sodium hydroxide solution with a pH of 10, the temperature of the reduced pressure distilled water is 70°C, and the pressure is 80% of the atmospheric pressure. The extractant uses a mixed solution of toluene and ether, and the volume ratio of toluene to ether is 2:3. The pressure of the reduced pressure is 90% of the atmospheric pressure and the temperature is 60°C. The ether in the extractant can be recovered by the reduced pressure stirring in step 3, and the ether is converted into steam during the reduced pressure and recovered after cooling.

[0030] The aqueous ether adopts a saturated aqueous ether liquid, and the preparation method of the saturated aqueous ether liquid comprises the following steps: a1, placing the ether in a sealed heating kettle and heating it at a constant temperature to form an ether gas-liquid mixture, and the temperature of the constant temperature heating is 50°C; a2, using nitrogen as a purge gas to purge the heating kettle at a uniform speed, and then passing the purge gas into low-temperature distilled water, and letting it stand to obtain a layered liquid, the temperature of the nitrogen is 50°C, the flow rate of the purge gas is 10mL / min, and the temperature of the low-temperature distilled water is 10°C; the standing temperature is 5°C; a3, letting the layered liquid stand at a low temperature for 30 minutes, and then extracting the ether layer and storing it at a low temperature to obtain an aqueous ether liquid.

[0031] Example 3

[0032] A method for preparing hydrogen-containing MQ silicone resin comprises the following steps:

[0033] Step 1, adding ethyl silicate and 3-chloropropyltrichlorosilane to a mixed solvent and stirring evenly, then dropping distilled water and performing low-temperature ultrasound for 25 minutes, and standing to obtain a mixed solution, wherein the molar ratio of ethyl silicate to 3-chloropropyltrichlorosilane is 3:1, the mixed solvent is a mixed solvent of ether and ethanol, and the volume ratio of ether to ethanol is 1:5, the stirring speed for stirring evenly is 200r / min, the concentration of ethyl silicate in the mixed solvent is 350g / L, the amount of distilled water added is 2% of the mixed solvent, and the dropping speed is 1mL / min, the temperature of the low-temperature ultrasound is 8°C, the ultrasound frequency is 80kHz, and the standing temperature is 28°C;

[0034] Step 2, adding methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane to diethyl ether and stirring evenly to form a homogeneous dispersion, then adding aqueous diethyl ether liquid and performing low-temperature ultrasound for 25 minutes to obtain a precursor solution, wherein the molar ratio of the methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane is 3:2:1, the concentration of the methylchlorosilane in diethyl ether is 250g / L, the stirring speed for uniform stirring is 400r / min, the volume ratio of the aqueous diethyl ether liquid to the diethyl ether is 2:1, the ultrasonic frequency of the low-temperature ultrasound is 80kHz, and the temperature is 8°C;

[0035] Step 3, adding hydrochloric acid to the mixed solution to adjust the pH to 5, then quickly adding the precursor solution, and obtaining a reaction solution by reducing pressure and stirring; the mass concentration of the hydrochloric acid is 15%, and the M / Q value in the reaction solution is 0.9; the adding time of the precursor solution is 4 minutes, the pressure of the reduced pressure stirring is 85% of the atmospheric pressure, and the temperature is 20°C;

[0036] Step 4, neutralize the reaction solution with pH, ​​and distill under reduced pressure for 15 minutes, then add an extractant for multiple extractions, and reduce the pressure of the extract to obtain a hydrogen-containing MQ silicone resin. The pH neutralization uses a sodium hydroxide solution with a pH of 9, the temperature of the reduced pressure distilled water is 65°C, and the pressure is 75% of the atmospheric pressure. The extractant uses a mixed solution of toluene and ether, and the volume ratio of toluene to ether is 2:3. The pressure of the reduced pressure is 85% of the atmospheric pressure and the temperature is 50°C. The ether in the extractant can be recovered by the reduced pressure stirring in step 3, and the ether is converted into steam during the reduced pressure and recovered after cooling.

[0037] The aqueous ether adopts a saturated aqueous ether liquid, and the preparation method of the saturated aqueous ether liquid comprises the following steps: a1, placing the ether in a sealed heating kettle and heating it at a constant temperature to form an ether gas-liquid mixture, and the temperature of the constant temperature heating is 47°C; a2, using nitrogen as a purge gas to purge the heating kettle at a uniform speed, and then passing the purge gas into low-temperature distilled water, and letting it stand to obtain a layered liquid, the temperature of the nitrogen is 45°C, the flow rate of the purge gas is 8mL / min, and the temperature of the low-temperature distilled water is 8°C; the standing temperature is 2°C; a3, letting the layered liquid stand at a low temperature for 25 minutes, and then extracting the ether layer and storing it at a low temperature to obtain an aqueous ether liquid.

[0038] Comparative Example 1

[0039] A method for preparing hydrogen-containing MQ silicone resin comprises the following steps:

[0040] Step 1, adding ethyl silicate to a mixed solvent and stirring evenly, then dropping distilled water and performing low-temperature ultrasound for 25 minutes, and standing to obtain a mixed solution, wherein the mixed solvent is a mixed solvent of ether and ethanol, and the volume ratio of ether to ethanol is 1:5, the stirring speed for stirring evenly is 200r / min, the concentration of ethyl silicate in the mixed solvent is 470g / L, the amount of distilled water added is 2% of the mixed solvent, and the dropping speed is 1mL / min, the temperature of the low-temperature ultrasound is 8°C, the ultrasound frequency is 80kHz, and the standing temperature is 28°C;

[0041] Step 2, adding methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane to diethyl ether and stirring evenly to form a homogeneous dispersion, then adding aqueous diethyl ether liquid and performing low-temperature ultrasound for 25 minutes to obtain a precursor solution, wherein the molar ratio of the methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane is 3:2:1, the concentration of the methylchlorosilane in diethyl ether is 250g / L, the stirring speed for uniform stirring is 400r / min, the volume ratio of the aqueous diethyl ether liquid to the diethyl ether is 2:1, the ultrasonic frequency of the low-temperature ultrasound is 80kHz, and the temperature is 8°C;

[0042] Step 3, adding hydrochloric acid to the mixed solution to adjust the pH to 5, then quickly adding the precursor solution, and obtaining a reaction solution by reducing pressure and stirring; the mass concentration of the hydrochloric acid is 15%, and the M / Q value in the reaction solution is 0.9; the adding time of the precursor solution is 4 minutes, the pressure of the reduced pressure stirring is 85% of the atmospheric pressure, and the temperature is 20°C;

[0043] Step 4, neutralize the reaction solution with pH, ​​and distill under reduced pressure for 15 minutes, then add an extractant for multiple extractions, and reduce the pressure of the extract to obtain a hydrogen-containing MQ silicone resin. The pH neutralization uses a sodium hydroxide solution with a pH of 9, the temperature of the reduced pressure distilled water is 65°C, and the pressure is 75% of the atmospheric pressure. The extractant uses a mixed solution of toluene and ether, and the volume ratio of toluene to ether is 2:3. The pressure of the reduced pressure is 85% of the atmospheric pressure and the temperature is 50°C. The ether in the extractant can be recovered by the reduced pressure stirring in step 3, and the ether is converted into steam during the reduced pressure and recovered after cooling.

[0044] The aqueous ether adopts a saturated aqueous ether liquid, and the preparation method of the saturated aqueous ether liquid comprises the following steps: a1, placing the ether in a sealed heating kettle and heating it at a constant temperature to form an ether gas-liquid mixture, and the temperature of the constant temperature heating is 47°C; a2, using nitrogen as a purge gas to purge the heating kettle at a uniform speed, and then passing the purge gas into low-temperature distilled water, and letting it stand to obtain a layered liquid, the temperature of the nitrogen is 45°C, the flow rate of the purge gas is 8mL / min, and the temperature of the low-temperature distilled water is 8°C; the standing temperature is 2°C; a3, letting the layered liquid stand at a low temperature for 25 minutes, and then extracting the ether layer and storing it at a low temperature to obtain an aqueous ether liquid.

[0045] Comparative Example 2

[0046] Comparative Example 2 uses commercially available hydrogen-containing MQ silicone resin, specifically RQO-HMQ103 from Shandong Baiqian Chemical Co., Ltd.

[0047] Performance Testing

[0048] The products of Examples 1-3 and Comparative Examples 1-2 were used as test samples to perform performance tests, and the results are as follows:

[0049] Table 1 Performance test data

[0050]

[0051] As can be seen from Table 1, the technical solution uses chloropropyltrichlorosilane as a dopant, which can effectively reduce the molecular compactness, thereby increasing the surface exposure of the active group and improving the activity of the hydrogenated MQ silicone resin.

[0052] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A method for preparing a hydrogenated MQ silicone resin, characterized in that: The steps include: Step 1, adding ethyl silicate and 3-chloropropyltrichlorosilane to a mixed solvent and stirring evenly, then dropping distilled water and performing low-temperature ultrasonic treatment for 20-30 minutes, and standing to obtain a mixed solution; Step 2, adding methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane to diethyl ether and stirring evenly to form a homogeneous dispersion, then adding aqueous diethyl ether solution and performing low-temperature ultrasound for 20-30 minutes to obtain a precursor solution; Step 3, adding hydrochloric acid to the mixed solution to adjust the pH to 5-6, then quickly adding the precursor solution, and stirring after reducing the pressure to obtain a reaction solution; Step 4, neutralizing the pH of the reaction solution, and distilling under reduced pressure for 10-20 minutes, then adding an extractant for multiple extractions, and reducing the pressure of the extract to obtain a hydrogen-containing MQ silicone resin.

2. The method for preparing the hydrogenated MQ silicone resin according to claim 1, characterized in that: The molar ratio of ethyl silicate to 3-chloropropyltrichlorosilane in step 1 is 2-3:1, the mixed solvent is a mixed solvent of ether and ethanol, and the volume ratio of ether to ethanol is 1:5-6, the stirring speed for uniform stirring is 100-300r / min, and the concentration of ethyl silicate in the mixed solvent is 300-400g / L.

3. The method for preparing the hydrogenated MQ silicone resin according to claim 1, characterized in that: The amount of distilled water added in step 1 is 1-2% of the mixed solvent, and the dropping speed is 1-2 mL / min. The temperature of the low-temperature ultrasound is 5-10° C., the ultrasound frequency is 70-90 kHz, and the standing temperature is 25-30° C.

4. The method for preparing the hydrogenated MQ silicone resin according to claim 1, characterized in that: The molar ratio of methylchlorosilane, dimethylchlorosilane and trimethylchlorosilane in step 2 is 2-3:2-3:1, the concentration of methylchlorosilane in diethyl ether is 200-300 g / L, and the stirring speed for uniform stirring is 300-500 r / min.

5. The method for preparing the hydrogenated MQ silicone resin according to claim 1, characterized in that: The volume ratio of the aqueous ether liquid to ether in step 2 is 2-3:1, the ultrasonic frequency of the low-temperature ultrasound is 70-90 kHz, and the temperature is 5-10°C.

6. The method for preparing the hydrogenated MQ silicone resin according to claim 1, characterized in that: The mass concentration of hydrochloric acid in step 3 is 10-20%, and the M / Q value in the reaction solution is 0.8-0.9; the addition time of the precursor solution is 3-5 minutes, the pressure of the reduced pressure stirring is 80-90% of the atmospheric pressure, and the temperature is 20-25°C.

7. The method for preparing the hydrogenated MQ silicone resin according to claim 1, characterized in that: The pH neutralization in step 4 uses a sodium hydroxide solution with a pH of 9-10, the temperature of the reduced pressure distilled water is 60-70° C., and the pressure is 70-80% of the atmospheric pressure.

8. The method for preparing the hydrogenated MQ silicone resin according to claim 1, characterized in that: The extractant in step 4 is a mixture of toluene and ether, and the volume ratio of toluene to ether is 2:2-3. The pressure of the reduced pressure is 80-90% of the atmospheric pressure, and the temperature is 40-60°C.

9. The method for preparing the hydrogenated MQ silicone resin according to claim 1, characterized in that: The ether in the extractant in step 4 can be recovered by reducing pressure and stirring in step 3, and the ether is converted into steam under reduced pressure and recovered after cooling.

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