A method for producing a diphenyl silicone oil

Abstract

The application provides a production method of diphenyl silicone oil, comprising the following steps: S100, diphenyldimethoxysilane and a first chain extender dimethylcyclosiloxane are subjected to chain extension in the presence of a first catalyst, and after the chain extension, decolorization treatment is performed by using activated carbon; the amount of the first chain extender is 30-80 wt% of the mass of the diphenyldimethoxysilane; S200, alcohol solvent and inorganic acid aqueous solution are added, and hydrolysis is performed under a condensation reflux condition, the hydrolysis product is washed with water, and the solvent is removed, so that low-viscosity hydroxyl-terminated diphenyl silicone oil is obtained; S300, the low-viscosity hydroxyl-terminated diphenyl silicone oil and a second chain extender are subjected to second chain extension in the presence of a second catalyst, so that product diphenyl silicone oil is obtained. The application does not use toxic organic solvents, the viscosity of the intermediate product is low, the product appearance is colorless and transparent, and different viscosity and different functional group-terminated diphenyl silicone oil products can be conveniently prepared.

Description

Technical Field

[0001] The invention belongs to the technical field of organic silicon, and particularly relates to a preparation method of diphenyl silicone oil. Background Art

[0002] It is well known that when preparing methylphenyl silicone oil, octaphenylcyclotetrasiloxane or tetraphenylcyclotetrasiloxane is reacted with the corresponding end-capping agent to prepare the corresponding hydroxyl-terminated methylphenyl silicone oil, M-terminated methylphenyl silicone oil, vinyl-terminated methylphenyl silicone oil, and hydrogen-terminated methylphenyl silicone oil, and the product appearance is colorless and transparent; while using diphenyldimethylsilane (diphenyldichlorosilane) or methylphenyldimethoxysilane (or methylphenyldichlorosilane) for hydrolysis, the viscosity of the product is large, and even a loop phenomenon occurs, so that part of the hydrolysis product adheres to the wall of the reactor, the position of the stirring rod, etc., which not only makes the phenyl content of the target product low, but also in this case, it is difficult to use activated carbon for decolorization. The corresponding hydroxyl-terminated methylphenyl silicone oil, M-terminated methylphenyl silicone oil, vinyl-terminated methylphenyl silicone oil, and hydrogen-terminated methylphenyl silicone oil prepared therefrom have a light yellow appearance.

[0003] It can be seen from the two patents of Jiangxi Beiteli New Materials Co., Ltd. (CN202311644215.2-A method for synthesizing diphenylsilanediol and a method for preparing octaphenylcyclotetrasiloxane) that the product of the hydrolysis of diphenyldimethoxysilane is a powdered solid of diphenylsilanediol (melting point 144-147°C) or a powdered solid of octaphenylcyclotetrasiloxane (melting point 196-198°C). Obviously, if diphenylsilanediol or octaphenylcyclotetrasiloxane is used to prepare methylphenyl silicone oil products, the cost will increase sharply.

[0004] CN201310003581.X discloses a method for preparing hydroxy-terminated polymethylphenyl silicone oil, which uses diphenyldichlorosilane and dimethyldichlorosilane for hydrolysis to prepare small-molecule hydroxydiphenyl silicone oil. Dimethyldichlorosilane is flammable and volatile (boiling point is only 70.3°C), and easily hydrolyzes to produce HCl, which is harmful to both the human body and the environment. Its vapor and liquid can cause skin burns. Inhalation is not only toxic but also irritates the throat, causing difficulty breathing and even life-threatening. The reactor must use a more expensive enamel reactor. Because dimethyldichlorosilane will produce hydroxyl groups during the subsequent hydrolysis process, the patent adopts an acetylation method and then a second hydrolysis to obtain a small-molecule hydroxy-terminated phenylmethyl silicone oil. It should be noted that the decolorization process of this patent is based on the second hydrolysis after acylation to obtain a small-molecule hydroxy-terminated phenylmethyl silicone oil with lower viscosity.

[0005] CN201711208626.1 discloses a method for preparing methylphenyl vinyl silicone oil, which comprises the following steps: using a mixture of diphenyldimethoxysilane, octamethylcyclotetrasiloxane, dimethylvinylethoxysilane, concentrated sulfuric acid and toluene, stirring at 30-45°C for 1h, then keeping the temperature at 35-50°C, adding deionized water dropwise within 1-2h, heating and reflux for 4h after the addition is completed for hydrolysis and condensation reaction to obtain a hydrolysis mixture, then standing and cooling the hydrolysis mixture to room temperature, separating the organic layer and washing the organic layer with deionized water until neutral, adding 0.1-1g of potassium hydroxide to the organic layer, heating and refluxing for 4h to obtain an azeotropic reflux liquid, and then stirring and neutralizing with 20-80g of cationic resin, sampling and determining the potassium ion content in the mixture while stirring, then filtering, and removing the remaining toluene and low-boiling substances in vacuum at a vacuum degree of 0.075MPa and a temperature of 200°C for 2-4h to obtain methylphenyl vinyl silicone oil. Toluene can reduce the viscosity of the system, but toluene still needs to be removed eventually. Moreover, the use of toluene is not green and environmentally friendly and is a toxic reagent.

[0006] In summary, the traditional hydrolysis process of diphenyldimethoxysilane (or diphenyldichlorosilane) generally co-hydrolyzes it with dimethyl dichloride, which not only corrodes the equipment but also poses a hidden danger of harm to the human body. In the hydrolysis process, hydroxyl groups are produced. In the acidic system, some of the hydroxyl groups will condense, resulting in a high viscosity of the hydrolyzed material after hydrolysis, which is not conducive to activated carbon decolorization and filtration, and will also cause the final product to have a light yellow appearance. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to address the shortcomings of the prior art in preparing methylphenyl silicone oil, which uses toxic organic solvents (such as toluene), resulting in high viscosity of the intermediate product, which is not conducive to decolorization and has a yellow appearance. The present invention provides a method for producing methylphenyl silicone oil, which can conveniently prepare diphenyl silicone oil products with different viscosities and different functional group end-capping, does not use toxic organic solvents such as toluene, and has a colorless and transparent product appearance, and does not cause white paste to stick to the wall during the production process.

[0008] The objectives of the present invention are achieved through the following technical solutions.

[0009] A method for producing diphenyl silicone oil comprises the following steps:

[0010] S100, diphenyldimethoxysilane and the first chain extender dimethylcyclosiloxane are chain extended in the presence of a first catalyst, and after chain extension, activated carbon is used for decolorization; the first chain extender is dimethylcyclosiloxane, and the amount of the first chain extender is 30-80wt% of the mass of diphenyldimethoxysilane;

[0011] S200, add alcohol solvent and inorganic acid aqueous solution, hydrolysis under the condition of condensation reflux, hydrolysis product water washing, remove the solvent, get low viscosity hydroxyl terminated diphenyl silicone oil;

[0012] S300, low viscosity hydroxyl terminated diphenyl silicone oil and second chain extender, in the presence of second catalyst, second chain extension, get product diphenyl silicone oil; second chain extender is selected from at least one of low viscosity α, ω-dihydroxydimethylsiloxane or low viscosity hydroxyl terminated diphenyl silicone oil, dimethylcyclosiloxane.

[0013] The application takes diphenyldimethoxysilane as starting material, the viscosity of product is low after first chain extension, at this time, decolorization treatment is convenient, the final product diphenyl silicone oil is colorless and transparent product, and the whole preparation process, especially the inner wall of the reactor after concentration, will not have white paste to affect production. Second chain extension can prepare diphenyl silicone oil with different viscosity and different functional groups by adding various end-capping agents. The amount of first chain extender is crucial in the first chain extension, preferably 30-80wt% of the mass of diphenyldimethoxysilane, too little first chain extender, white paste will be produced on the inner wall of the reactor after concentration, and there will be turbidity; too much chain extender, the viscosity after hydrolysis will be large, and the separation speed of the separatory funnel after water washing will be slow.

[0014] Further, in step S100, the first chain extender dimethylcyclosiloxane is selected from at least one of octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6), such as dimethylcyclosiloxane mixed ring (DMC, wherein D4 is about 75-85%, D5 is 10%-15%, and D6 is about 5-10%); the first catalyst is selected from trifluoromethanesulfonic acid or tetramethylammonium hydroxide silanol salt, or potassium hydroxide silanol salt.

[0015] Further, when the first catalyst is trifluoromethanesulfonic acid, the reaction temperature is 40-70℃, and the reaction time is 2-6h; when the first catalyst is tetramethylammonium hydroxide silanol salt, the reaction temperature is set to 90-125℃, and the reaction time is 2-6h, and after the reaction is completed, the temperature is raised to 140-150℃, and the tetramethylammonium hydroxide catalyst is thermally decomposed and volatilized out after heat preservation for 1-2h; when the first catalyst is potassium hydroxide silanol salt, the reaction temperature is 140-160℃, and the reaction time is 3-7h.

[0016] Further, in step S100, the amount of first chain extender is 30-80wt% of the mass of diphenyldimethoxysilane, and the amount of first catalyst is 20-300ppm, preferably 30-100ppm, of the mass of diphenyldimethoxysilane.

[0017] Furthermore, in step S100, the amount of activated carbon used is 0.5-3wt% of the mass of diphenyldimethoxysilane, preferably 1-2wt%. The specific surface area of ​​the activated carbon is 900-1500m 2 / g.

[0018] Furthermore, in step S200, the alcohol solvent is selected from at least one of methanol, ethanol, and isopropanol, and the amount of the alcohol solvent added is 20-80wt% of the mass of the diphenyldimethoxysilane in step S100, preferably 20-55wt%; the inorganic acid aqueous solution is dilute sulfuric acid with a pH of 1-4, or dilute hydrochloric acid with a pH of 1-4; the amount of the inorganic acid aqueous solution used is 20-30wt% of the mass of the diphenyldimethoxysilane in step S100.

[0019] Furthermore, in step S200, the hydrolysis reaction temperature is 50-70°C, the reaction time is 4-7 hours, and the alcohol solvent is removed at 50-90°C and a vacuum degree of -0.07 to -0.1 MPa.

[0020] In step S200, the viscosity of the obtained intermediate product, low-viscosity hydroxyl-terminated diphenyl silicone oil, is 400-1000 mm 2 / s.

[0021] Furthermore, in step 300, the definition of dimethylcyclosiloxane is the same as that in step S100, that is, at least one selected from octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6); the viscosity of the low-viscosity α,ω-dihydroxy polydimethylsiloxane is 50 to 140 mPa.s, and the viscosity of the low-viscosity hydroxyl-terminated diphenyl silicone oil is 300 to 600 mm 2 / s; further, the amount of the second chain extender is 100-200wt% of the mass of the low-viscosity hydroxyl-terminated diphenyl silicone oil in step S200.

[0022] Furthermore, in step 300, a capping agent is also added; when it is necessary to prepare trimethylsilyl-terminated (M-terminated) diphenyl silicone oil, the capping agent is selected from hexamethyldisiloxane (MM), or a viscosity of 5-40mm 2 / s dimethyl silicone oil; when it is necessary to prepare alkenyl-terminated diphenyl silicone oil, the end-capping agent is selected from tetramethyl divinyl silane, or a viscosity of 5-40mm 2 / s vinyl silicone oil; when it is necessary to prepare active hydrogen-terminated diphenyl silicone oil, the end-capping agent is selected from tetramethyldihydrosilane, or a viscosity of 5-40mm 2hydrogen-containing silicone oil. The amount of end-capping agent is 5-15 wt% of the mass of the low viscosity hydroxyl-terminated diphenyl silicone oil described in step S200, preferably 8-11 wt%; the second catalyst is selected from trifluoromethanesulfonic acid or tetramethylammonium hydroxide silanolate, or potassium hydroxide silanolate or phosphonium chloride. The second catalyst is selected from the same range as the first catalyst, and the reaction temperature and reaction time are as described above.

[0023] Compared with the prior art, the present application has the following advantages:

[0024] Firstly, the present application uses dimethylcyclosiloxane, which does not produce additional hydroxyl groups, so the viscosity of the product after the first chain extension is less than 10 mm 2 / s, at this time, the use of activated carbon for decolorization treatment is more convenient than after hydrolysis. Moreover, the product after the first chain extension has low viscosity, which is beneficial to decolorization. The hydrolysis is carried out in an alcohol solvent, and the hydrolysis product is obtained by washing with water. The separation speed after each water washing is fast, which can be completed within 20 minutes. The hydrolysis product can be further chain-extended to prepare products such as hydroxyl-terminated diphenyl silicone oil, methyl-terminated diphenyl silicone oil, vinyl-terminated diphenyl silicone oil, and hydrogen-terminated diphenyl silicone oil with different viscosities.

[0025] Secondly, in the entire process of the present application, there is no white (paste-like) solid attached to the wall of the reactor or the stirring rod. After scale-up production, the product can be smoothly transferred in the pipeline, which is suitable for large-scale production.

[0026] Thirdly, the present application uses diphenyldimethoxysilane and dimethylcyclosiloxane to prepare various types of functional group-terminated diphenyl silicone oil. The raw materials used do not involve diphenyldichlorosilane, which is corrosive to production equipment. Moreover, during the production process, no HCl gas, which is harmful to the human body, is produced. In the first chain extension of the present application, tetramethylammonium hydroxide silanolate or potassium hydroxide silanolate can be used, and the reaction kettle can not be a enamel kettle.

[0027] Fourthly, the present application involves a hydrolysis process, which uses an alcohol solvent as the organic solvent, rather than a toxic reagent such as toluene. Moreover, the viscosity of the diphenyldimethoxysilane and dimethylcyclosiloxane after chain extension, decolorization, hydrolysis, and removal of the solvent is within 1000 mm 2 / s, preferably 500 mm 2 / s in the preferred embodiment. The viscosity does not need to be reduced by toluene, and the product can be further reacted with chain extender 2 and the corresponding end-capping agent to prepare hydroxyl-terminated diphenyl silicone oil, methyl-terminated diphenyl silicone oil, vinyl-terminated diphenyl silicone oil, and hydrogen-terminated diphenyl silicone oil with different viscosities. Compared with the use of diphenylsilanediol or octaphenylcyclotetrasiloxane, the present application has a significant cost advantage. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further explained below with reference to specific embodiments.

[0029] Diphenyldimethoxysilane was purchased from Jiangxi Hongbai New Materials Co., Ltd.;

[0030] D4 and DMC (D4 about 75%, D5 15%, D6 about 10%) were purchased from Jiangxi Lanxing Xinghuo Silicone Co., Ltd.;

[0031] Example 1

[0032] (S100) Add 150 g of diphenyldimethoxysilane and 45 g of octamethylcyclotetrasiloxane (D4) to a reactor, raise the temperature to 50° C., -0.1 MPa, dehydrate for 1 h, then switch to condensation reflux, raise the temperature to 150° C., add 0.0394 g of 15% potassium hydroxide silicon alkoxide, and react for 4 h; cool to 30° C., add 2 g of activated carbon for decolorization for 1 h, and filter;

[0033] (S200) 50 g of isopropanol and 30 g of hydrochloric acid solution with a pH of 2 were added to the filtrate, and the mixture was condensed and refluxed at 60° C. for 5 h; the product was transferred to a separatory funnel and washed with water twice; the material was transferred to a reactor, the temperature was set at 60° C., the vacuum degree was -0.1 MPa, and the solvent was removed to obtain a viscosity of 402 mm 2 / s low viscosity hydroxyl-terminated diphenyl silicone oil, no solid particles remain on the wall of the reactor.

[0034] Example 2

[0035] (S100) 150 g of diphenyldimethoxysilane and 80 g of DMC were added to a reactor, the temperature was raised to 60° C., -0.09 MPa, dehydrated for 1 hour, then switched to condensation reflux, and the temperature was raised to 110° C. 0.7666 g of 3% tetramethylammonium hydroxide silicon alkoxide was added, the reaction was continued for 3.5 hours, the temperature was raised to 150° C., and the temperature was kept for 1 hour to break the catalyst; after cooling to 30° C., 2 g of activated carbon was added for decolorization for 1 hour, and the mixture was filtered;

[0036] (S200) 70 g of n-butanol and 35 g of hydrochloric acid solution with a pH of 2 were added to the filtrate, and the mixture was condensed and refluxed at 60° C. for 5 h; the product was transferred to a separatory funnel and washed with water three times; the material was transferred to a reactor, the temperature was set at 60° C., the vacuum degree was -0.1 MPa, and the solvent was removed to obtain a viscosity of 458 mm 2 / s low viscosity hydroxyl-terminated diphenyl silicone oil, no solid particles remain on the wall of the reactor.

[0037] Example 3

[0038] (S100) To the reactor, 150 g of diphenyldimethoxysilane, 120 g of DMC were added, and the temperature was raised to 60 °C, -0.09 MPa, and dehydrated for 1 h, then changed to condensation reflux, and the temperature was raised to 75 °C, 0.405 g of 2% toluene solution of trifluoromethanesulfonic acid was added, and the reaction was carried out for 3.5 h; after cooling to 30 °C, 2 g of activated carbon was added for decolorization for 1 h, and then filtered;

[0039] (S200) To the filtrate, 80 g of ethanol, 35 g of pH = 2 hydrochloric acid solution were added, and the condensation reflux was carried out at 60 °C for 5 h; the product was transferred to a separatory funnel, and washed with water 3 times; the material was transferred to a reaction kettle, the temperature was set to 60 °C, and the vacuum degree was -0.1 MPa, and the solvent was removed to obtain a low viscosity hydroxyl-terminated diphenyl silicone oil with a viscosity of 675 mm 2 / s, and no solid particles were left on the kettle wall of the reaction kettle.

[0040] Comparative Example 1

[0041] The other conditions were the same as in Example 1, except that in step (S100), the amount of D4 added was 40 g.

[0042] Comparative Example 2

[0043] The other conditions were the same as in Example 1, except that in step (S100), the amount of D4 added was 30 g.

[0044] Comparative Example 3

[0045] To the reactor, 150 g of diphenyldimethoxysilane, 80 g of ethanol, 35 g of pH = 2 hydrochloric acid solution were added, and the condensation reflux was carried out at 60 °C for 5 h; the product was transferred to a separatory funnel, and the lower oil layer flowed with difficulty.

[0046] Comparative Example 4

[0047] The other conditions were the same as in Example 1, except that in step (S100), the amount of D4 added was 150 g.

[0048] The products of the above examples and comparative examples were characterized as shown in Table 1 below.

[0049] Table 1 Characterization of low viscosity hydroxyl-terminated diphenyl silicone oil

[0050]

[0051] The product of Example 1 was further used to prepare diphenyl silicone oils terminated with different functionalities:

[0052] Application Example 1: Preparation of hydroxyl-terminated diphenyl silicone oil

[0053] 140 g of the low-viscosity hydroxyl-terminated diphenyl silicone oil of Example 1 was placed in a reactor, heated to 75° C., 0.014 g of 1% trifluoromethanesulfonic acid catalyst (toluene as solvent) was added, reacted for 2 h, 0.016 g of 1% NaHCO3 aqueous solution was added, neutralized for 1 h, and then heated to 170° C. and degassed for 2 h to obtain a product with a viscosity of 24500 mm 2 / s of hydroxyl-terminated diphenyl silicone oil.

[0054] Application Example 2: Preparation of M-terminated diphenyl silicone oil

[0055] 47g of the low-viscosity hydroxyl-terminated diphenyl silicone oil of Example 1, 87.5g of DMC, 5g of a viscosity of 20mm 2 / s dimethyl silicone oil was placed in a reactor, heated to 50 ° C, dehydrated at -0.1 MPa for 1 hour, and then heated to 160 ° C, 0.028 g of 15% KOH silicon alkoxide was added, reacted for 5 hours, 0.0558 g of 15% silicon-based phosphate was added, neutralized for 1 hour, and then heated to 220 ° C, dehydrated for 2 hours to obtain a viscosity of 623mm 2 / s of M-terminated diphenyl silicone oil.

[0056] Application Example 3: Preparation of vinyl-terminated diphenyl silicone oil

[0057] 47g of the product of Example 1, 87.5g of D4, 5g of a viscosity of 24mm 2 / s of vinyl-terminated silicone oil was placed in a reactor, heated to 50 ° C, dehydrated at -0.1 MPa for 1 hour, then heated to 110 ° C, added with 1.4 g of 3% tetramethylammonium hydroxide silicon alkoxide, reacted for 5 hours, heated to 150 ° C, broken for 1 hour, then heated to 220 ° C, dehydrated for 2 hours, and the viscosity of the obtained product was 710 mm 2 / s vinyl terminated diphenyl silicone oil.

[0058] Application Example 4: Preparation of Hydrogen-Terminated Diphenyl Silicone Oil

[0059] 83 g of the product of Example 1 and 83 g of a viscosity of 90 mm 2 / s of α,ω-dihydroxypolydimethylsiloxane, 7g of viscosity is 7mm 2 / s of hydrogen-terminated silicone oil was placed in a reactor, heated to 55 ° C, dehydrated at -0.1 MPa for 1 hour, added with 0.0035g of phosphine chloride, reacted for 3 hours, added with 0.007g of triamylamine, neutralized for 1 hour, heated to 205 ° C, dehydrated for 2 hours, and obtained a viscosity of 150mm 2 / s of hydrogen-terminated diphenyl silicone oil.

[0060] Application Characterization:

[0061]

Claims

1. A method for producing diphenyl silicone oil, characterized in that, The following steps are involved: S100, diphenyldimethoxysilane and the first chain extender dimethylcyclosiloxane are chain extended in the presence of a first catalyst, and after chain extension, activated carbon is used for decolorization; the first chain extender is dimethylcyclosiloxane, and the amount of the first chain extender is 30-80wt% of the mass of diphenyldimethoxysilane; S200, adding an alcohol solvent and an inorganic acid aqueous solution, hydrolyzing under condensation reflux conditions, washing the hydrolyzate with water, and removing the solvent to obtain a low-viscosity hydroxyl-terminated diphenyl silicone oil; S300, low viscosity hydroxyl-terminated diphenyl silicone oil and a second chain extender, in the presence of a second catalyst, perform a second chain extension to obtain product diphenyl silicone oil; the second chain extender is selected from at least one of low viscosity α, ω-dihydroxy polydimethylsiloxane or low viscosity hydroxyl-terminated diphenyl silicone oil and dimethylcyclosiloxane.

2. The production method according to claim 1, characterized in that In step S100, the dimethylcyclosiloxane is selected from at least one of octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6); and the first catalyst is selected from trifluoromethanesulfonic acid, tetramethylammonium hydroxide siliconate or potassium hydroxide siliconate.

3. The production method according to claim 2, characterized in that When the first catalyst is trifluoromethanesulfonic acid, the reaction temperature is 40-70°C and the reaction time is 2-6 h; when the first catalyst is tetramethylammonium hydroxide siliconate, the reaction temperature is set to 90-125°C and the reaction time is 2-6 h. After the reaction is completed, the temperature is raised to 140-150°C and the catalyst is kept warm for 1-2 h. When the first catalyst is potassium hydroxide siliconate, the reaction temperature is 140-160°C and the reaction time is 3-7 h.

4. The production method according to claim 1, characterized in that In step S100, the amount of the first chain extender is 30-80 wt% of the mass of diphenyldimethoxysilane, and the amount of the first catalyst is 20-300 ppm of the mass of diphenyldimethoxysilane.

5. The production method according to claim 4, characterized in that In step S100, the amount of the first catalyst used is 30-100 ppm based on the mass of diphenyldimethoxysilane.

6. The production method according to claim 1, characterized in that In step S100, the amount of activated carbon used is 0.5-3 wt% of the mass of diphenyldimethoxysilane; the specific surface area of ​​the activated carbon is 900-1500 m 2 / g.

7. The production method according to claim 6, characterized in that In step S100, the amount of activated carbon used is 1-2 wt% of the mass of diphenyldimethoxysilane.

8. The production method according to claim 1, characterized in that In step S200, the alcohol solvent is selected from at least one of methanol, ethanol, and isopropanol, and the amount of the alcohol solvent added is 20-80wt% of the mass of the diphenyldimethoxysilane in step S100; the inorganic acid aqueous solution is dilute sulfuric acid with a pH of 1-4, or dilute hydrochloric acid with a pH of 1-4; the amount of the inorganic acid aqueous solution used is 20-30wt% of the mass of the diphenyldimethoxysilane in step S100.

9. The production method according to claim 8, characterized in that The amount of the alcohol solvent added is 20-55 wt % of the mass of the diphenyldimethoxysilane in step S100.

10. The production method according to claim 1, characterized in that In step S200, the hydrolysis reaction temperature is 50-70°C and the reaction time is 4-7 hours; the removal of the alcohol solvent is carried out at 50-90°C and a vacuum degree of -0.07 to -0.1 MPa.

11. The production method according to claim 1, characterized in that In step S200, the viscosity of the obtained intermediate product, low-viscosity hydroxyl-terminated diphenyl silicone oil, is 400-1000 mm 2 / s.

12. The production method according to claim 1, characterized in that In step 300, the viscosity of the low-viscosity α,ω-dihydroxy polydimethylsiloxane is 50-140 mPa.s, and the viscosity of the low-viscosity hydroxyl-terminated diphenyl silicone oil is 300-600 mm 2 / s; The amount of the second chain extender used is 100-200 wt % of the mass of the low-viscosity hydroxyl-terminated diphenyl silicone oil in step S200.

13. The production method according to claim 1, characterized in that In step 300, a capping agent is also added; when it is necessary to prepare trimethylsilyl-terminated diphenyl silicone oil, the capping agent is selected from hexamethyldisiloxane (MM) or a viscosity of 5-40 mm 2 / s dimethyl silicone oil; when it is necessary to prepare alkenyl-terminated diphenyl silicone oil, the end-capping agent is selected from tetramethyl divinyl silane or a viscosity of 5-40 mm 2 / s vinyl silicone oil; when it is necessary to prepare active hydrogen-terminated diphenyl silicone oil, the end-capping agent is selected from tetramethyldihydrosilane or a viscosity of 5-40 mm 2 / s of hydrogenated silicone oil; the amount of the end-capping agent is 5-15wt% of the mass of the low-viscosity hydroxyl-terminated diphenyl silicone oil in step S200; and / or The second catalyst is selected from trifluoromethanesulfonic acid, tetramethylammonium hydroxide siliconate, potassium hydroxide siliconate or phosphonitrile chloride.

14. The production method according to claim 13, characterized in that In step 300, the amount of the end-capping agent used is 8-11 wt% of the mass of the low-viscosity hydroxyl-terminated diphenyl silicone oil in step S200.

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