A dynamic continuous flow production method for silicone resin

Abstract

The present invention belongs to the technical field of organic silicone resin production, and discloses a dynamic continuous flow production method of organic silicone resin. The method comprises: mixing an acid catalyst solution, a trialkoxysilane solution and a sodium silicate aqueous solution in a dynamic tubular reactor 1 for reaction, the intermediate reactant obtained and the end-capping agent solution are uniformly mixed and copolymerized through a dynamic tubular reactor 2 or a microchannel reactor, the polymerization solution obtained by the reaction is mixed with an organic solvent and then enters a balanced reactor for a balanced reaction, the reactant is allowed to stand for stratification, the upper organic layer is acid-washed, neutralized, and washed with water to obtain a resin mother liquor, which is concentrated and dried after filtration to obtain MQ silicone resin powder. The production method of the present invention uniformly mixes and reacts an acid catalyst solution, a small amount of trialkoxysilane solution and a sodium silicate aqueous solution in a dynamic mixer with a continuous stirring effect, which can well solve the problem of gel generation in the reaction, and realizes low-cost continuous large-scale production of MQ silicone resin by a water glass method.

Description

Technical Field

[0001] The invention belongs to the technical field of silicone resin production, and in particular relates to a dynamic continuous flow production method of organic silicone resin. Background Art

[0002] MQ resin is a polysiloxane with a double-layer structure consisting of monofunctional segments and tetrafunctional segments. It has excellent high and low temperature resistance, corrosion resistance, bonding performance, radiation resistance, etc., and is widely used as a surface treatment agent, reinforcing material, tackifier or other additive for polysiloxane.

[0003] MQ silicone resin has a variety of preparation methods, mainly divided into ethyl silicate method and water glass method, respectively using ethyl silicate or the polymerized state of ethyl silicate and sodium silicate as raw materials. Among them, the ethyl silicate method is widely used because of its mild reaction, easy operation, high yield, easy structure control, and narrow product molecular weight distribution. For example, patent CN 116769164 A discloses a continuous preparation method of MQ silicone resin, in which silicate, end-capping agent, and cosolvent are simultaneously pumped to a static mixer through a flow pump, and then mixed with dilute acid in a microchannel reactor to solve the uneven mass transfer and heat transfer of the hydrolysis-polycondensation reaction, and realize the continuous production of MQ silicone resin. However, the cost of using silicate raw materials is high. While using the sodium silicate method, its reaction is relatively fast, the M / Q molar ratio is difficult to control, and the prepared molecular weight distribution is wide and the yield is low.

[0004] At present, the water glass method for preparing MQ silicone resin still has the following problems: (1) gel and white precipitate are easily produced in the production process, which affects the yield and performance of the product; (2) the yield is low; (3) the structure of MQ silicone resin is complex and difficult to control; (4) the production process is complex and the equipment utilization rate is low. Although the industrial production of MQ silicone resin has been realized in China, the product quality is not very ideal. Therefore, researching and improving the process of preparing MQ silicone resin using cheap water glass as raw material, further exploring better process conditions, improving yield, reducing gelation, and simplifying the production process will become the research focus of the industrial large-scale production of MQ silicone resin prepared by water glass, which is of great significance to the silicone industry.

[0005] In our previous patent application CN116769165A, a method and device for continuous production of MQ silicone resin are disclosed. The gel time is mainly affected by adjusting the concentration of sulfuric acid, feed flow rate, and feed temperature, and the reaction time of the acid catalyst and sodium silicate can be adjusted by adjusting the length of the feed pipeline. However, since the reaction between the water glass solution and the acid catalyst is extremely fast, instantaneous, hydrolyzed and polycondensed, it will be very easy to gel if it is not stirred. Although it is possible to first feed material A and then material B to prevent material B from entering the material A pipeline and reacting with material A to cause blockage, the inevitable problem is that there will be a small amount of gel solid residue in the pipeline reactor, which leads to the occurrence of irresistible factors in the large-scale production process. The blockage causes the equipment to stop running as time goes by, causing huge losses. Summary of the invention

[0006] In view of the shortcomings and deficiencies of the above prior art, the object of the present invention is to provide a dynamic continuous flow production method for silicone resin. The production method of the present invention uniformly mixes and reacts the acid catalyst solution, the trialkoxysilane solution and the sodium silicate aqueous solution in a dynamic tubular reactor with a continuous stirring effect, which can solve the problem of reaction gel and realize low-cost continuous large-scale production of MQ silicone resin by the water glass method.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A dynamic continuous flow production method for an organosilicon resin comprises the following steps:

[0009] (1) pumping an acid catalyst solution, a trialkoxysilane solution and a sodium silicate aqueous solution into a dynamic tubular reactor 1 having a dynamic stirring and mixing effect, respectively, and uniformly mixing and reacting them during the dynamic rotation stirring process to obtain an intermediate reactant;

[0010] (2) the intermediate reactant of step (1) enters the dynamic tubular reactor 2 or the microchannel reactor through a pipeline, and at the same time, the mixed solution of the end-capping agent and the organic solvent is pumped into the dynamic tubular reactor 2 or the microchannel reactor for uniform mixing, so that a copolymerization reaction occurs to obtain a polymerization solution;

[0011] (3) The polymerization solution in step (2) is mixed with an organic solvent and then enters into an equilibrium reaction kettle for a final equilibrium reaction;

[0012] (4) The reactant obtained in step (3) is allowed to stand for stratification, and the upper organic layer is acid-washed, neutralized, and washed with water to obtain a resin mother liquor, which is filtered, concentrated, and dried to obtain MQ silicone resin powder.

[0013] The dynamic tubular reactor of the present invention is a tubular, elongated continuous flow operation reactor, which is a novel plug flow reactor. The main structure of the dynamic tubular reactor includes an external heat exchange jacket, a reaction tube, an internal stirring shaft, a motor, a sealing transmission device, etc. The external heat exchange jacket provides heating or cooling temperature control, the reaction tube provides the temperature and pressure resistant space required for the reaction material, and the motor provides power to drive the sealing transmission device and drive the internal stirring shaft to continuously stir and mix. It is a reaction device that can be purchased on the market. Such as the continuous oscillation stirring reactor (OAR) of Shenzhen Yizheng Technology Co., Ltd., the dynamic tubular reactor of Kexin Microflow Co., Ltd., and the dynamic tubular reactor (CN 212942877 U) of Shandong Weijing Chemical Technology Co., Ltd.

[0014] Preferably, the acid catalyst solution in step (1) is an inorganic acid solution or an organic acid solution, and the inorganic acid solution includes HCl, HClO 4 , H 2 SO 4 and H 3 PO 4 The organic acid solution comprises at least one acid solution of acetic acid, formic acid, propionic acid, p-toluenesulfonic acid, etc.

[0015] Preferably, the mass concentration of the acid catalyst solution in step (1) is 5% to 100%, more preferably 20 to 50%; the mass concentration of the sodium silicate aqueous solution is 10% to 50%; and the flow ratio of the acid catalyst solution to the sodium silicate aqueous solution is 0.05 to 5:0.1 to 10.

[0016] Preferably, the trialkoxysilane solution in step (1) is methyltrimethoxysilane or methyltriethoxysilane, more preferably methyltrimethoxysilane; the amount of trialkoxysilane added is 1.5% to 4% of the mass of sodium silicate. Under the above trialkoxysilane and addition conditions, the problem of reaction gel can be better solved without affecting the molecular weight of the obtained MQ silicone resin.

[0017] Preferably, the reaction temperature of the mixing reaction in step (1) is controlled to be 0-60° C., more preferably 20-40° C. If the reaction temperature in this step is too high, the reaction between the reactants will be accelerated, heat will be released, and the reaction will be too rapid to produce solid gel and cause blockage.

[0018] Preferably, in step (1), the mixing reaction time is adjusted to 10 to 600 seconds by controlling the flow rate of the acid catalyst solution and the sodium silicate aqueous solution pumped in and the capacity of the dynamic tubular reactor, or by connecting an appropriate pipeline, and more preferably the mixing reaction time is 100 to 180 seconds. The molecular weight of the intermediate reaction product can be controlled by controlling the reaction time of the acid catalyst solution and the sodium silicate aqueous solution.

[0019] Preferably, the end-capping agent in step (2) is one or more of hexamethyldisiloxane (MM), tetramethyldivinyldisiloxane (VI-MM), tetramethyldiphenyldisiloxane (Ph-MM), 1,3-bis(aminopropyl)tetramethyldisiloxane (NH-MM), tetramethyldisiloxane (H-MM), etc.

[0020] Preferably, the organic solvent in step (2) is one or more of methanol, ethanol, isopropanol, etc.

[0021] Preferably, the reaction temperature of the copolymerization reaction in step (2) is controlled to be 20-60°C, more preferably 45-60°C; the reaction time is controlled to be 5-60min, more preferably 10-30min. When the reaction temperature in this step is higher than 60°C, the organic solvent in the reactant will evaporate and affect the reaction.

[0022] Preferably, the material outlet of the dynamic tubular reactor 2 or the microchannel reactor in step (2) can be further connected to a static pipeline with a mixing effect to extend the reaction time.

[0023] Preferably, the flow ratio of the mixed solution of the end-capping agent and the organic solvent in step (2) to the sodium silicate aqueous solution in step (1) is 0.1-10:0.1-10.

[0024] Preferably, the organic solvent in step (3) is one or more of MM, toluene, xylene, cyclohexane, etc.

[0025] Preferably, the flow ratio of the organic solvent in step (3) to the sodium silicate aqueous solution in step (1) is 0.2-5:0.2-5; the conditions of the equilibrium reaction are specifically: reflux reaction at a reaction temperature of 40-80° C. for 2-8 hours.

[0026] Preferably, the drying in step (4) adopts a kettle dryer, a drum dryer, a belt dryer, a fluidized bed dryer, a mechanical stirring dryer and a spray dryer. A spray dryer with a purge device is more preferably used. When a spray dryer is used in this step, the resin solution is sprayed out through an atomizer, and after the solvent is evaporated at high temperature and turned into powder, the powder is a kind of powder with a particle size of 0.05 to 50um and is particularly light. It is easy to adhere to the tower wall and not fall into the tuyere at the bottom of the tower, which has a huge impact on the collection of powder and continuous operation. By designing a purge device, nitrogen can be circulated on the tower wall to purge the powder attached to the tower wall, thereby facilitating the continuous operation of the equipment and the collection of products.

[0027] Preferably, the acid-water layer after standing and stratifying in step (4) is neutralized with a base, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recycling.

[0028] Preferably, the weight average molecular weight of the MQ silicone resin finally obtained in step (4) is 2000 to 30000 g / mol.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The method for producing organic silicone resin in a dynamic continuous flow of the present invention adopts a dynamic tubular reactor with a dynamic stirring and mixing effect as a reaction vessel for the acid catalyst and the sodium silicate aqueous solution. As the stirring of the reactor is turned on, the acid catalyst and the sodium silicate solution enter the reactor. At the moment of contact, they can be driven to flow forward by the stirring of the stirring shaft, which can achieve a good mixing reaction effect. At the same time, by adding a small amount (1.5% to 4% of the mass of the sodium silicate) of trialkoxysilane, the problem of blockage caused by the instantaneous reaction between the two to form a gel solid is better solved, and at the same time, the molecular weight of the obtained MQ silicone resin is slightly affected.

[0031] (2) The reactor used for the copolymerization reaction in the production method of the present invention can be a dynamic tubular reactor or a microchannel reactor to realize the subsequent mixing reaction. After the feed is mixed in the dynamic tubular reactor 1, the intermediate product is a very uniform and transparent liquid without solid impurities; at this time, the microchannel reactor can be used to carry out the mixing reaction of the end-capping agent solution and the intermediate reactant.

[0032] (3) The production method of the present invention further uses a spray dryer with a purge device to dry the silicone resin, which effectively solves the problem that the resin powder is too light after molding and adheres to the tower wall and cannot come down, and can obtain a resin powder with a pure white appearance and uniform quality. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0034] Example 1

[0035] A dynamic continuous flow production method of an organosilicon resin according to the present embodiment comprises the following steps:

[0036] (1) A 37% sulfuric acid catalyst solution and a 20% sodium silicate aqueous solution are pumped into a dynamic tubular reactor 1 with a dynamic stirring and mixing effect, respectively, with the feed flow rate of the sulfuric acid catalyst solution being 0.5 L / min; the feed flow rate of the sodium silicate aqueous solution being 1.0 L / min, and the mixture is uniformly mixed and reacted during dynamic stirring (600 rpm), the reaction temperature is controlled at 25° C., and the reaction time is controlled at 120 s to obtain an intermediate reactant.

[0037] (2) The intermediate reactant of step (1) enters the dynamic tubular reactor 2 through a pipeline, and at the same time, a mixed solution of the end-capping agent MM and the isopropanol solvent (ratio of 7:20) is pumped into the dynamic tubular reactor 2 for uniform mixing, the feed flow rate of the mixed solution is 0.85 L / min, a copolymerization reaction occurs, the reaction temperature is controlled to 60° C., and the reaction time is controlled to 10 min to obtain a polymerization solution.

[0038] (3) The polymerization solution of step (2) was mixed with the organic solvent toluene (feed flow rate was 1.5 L / min) and then entered into a balanced reactor for reflux reaction at a reaction temperature of 65° C. for 2 h.

[0039] (4) The reactants obtained in step (3) are allowed to stand for stratification, and the upper organic layer is washed twice with concentrated sulfuric acid to remove the waste acid, and then alkali is added for neutralization, and then water is added for dissolution. After separation, the organic silicone resin mother liquor is obtained; the mother liquor is then filtered and concentrated, and sent to a spray dryer with a purge device for drying to obtain MQ silicone resin powder. The solvent evaporated by concentration and drying is condensed and recovered. The lower acid-water layer after standing for stratification is neutralized with alkali, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recycling.

[0040] The weight average molecular weight of the MQ silicone resin finally obtained in this example is 5868 g / mol.

[0041] Example 2

[0042] A dynamic continuous flow production method of an organosilicon resin according to the present embodiment comprises the following steps:

[0043] (1) A 37% sulfuric acid catalyst solution, a methyltrimethoxysilane solution and a 20% sodium silicate aqueous solution are respectively pumped into a dynamic tubular reactor 1 with a dynamic stirring and mixing effect, the feed flow rate of the sulfuric acid catalyst solution is 0.5 L / min; the feed flow rate of the methyltrimethoxysilane solution is 6 mL / min; the feed flow rate of the sodium silicate aqueous solution is 1.0 L / min, and the mixture is uniformly mixed and reacted during dynamic stirring (600 rpm), the reaction temperature is controlled at 25° C., and the reaction time is controlled at 120 s to obtain an intermediate reactant.

[0044] (2) The intermediate reactant of step (1) enters the dynamic tubular reactor 2 through a pipeline, and at the same time, a mixed solution of the end-capping agent MM and the isopropanol solvent (ratio of 7:20) is pumped into the dynamic tubular reactor 2 for uniform mixing, the feed flow rate of the mixed solution is 0.85 L / min, a copolymerization reaction occurs, the reaction temperature is controlled to 60° C., and the reaction time is controlled to 10 min to obtain a polymerization solution.

[0045] (3) The polymerization solution of step (2) and the organic solvent MM (feed flow rate is 1.5 L / min) are mixed and then enter into the equilibrium reactor, and refluxed at a reaction temperature of 65° C. for 2 h.

[0046] (4) The reactants obtained in step (3) are allowed to stand for stratification, and the upper organic layer is washed twice with concentrated sulfuric acid to remove the waste acid, and then alkali is added for neutralization, and then water is added for dissolution. After separation, the organic silicone resin mother liquor is obtained; the mother liquor is then filtered and concentrated, and sent to a spray dryer with a purge device for drying to obtain MQ silicone resin powder. The solvent evaporated by concentration and drying is condensed and recovered. The lower acid-water layer after standing for stratification is neutralized with alkali, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recycling.

[0047] The weight average molecular weight of the MQ silicone resin finally obtained in this example is 5642 g / mol.

[0048] Example 3

[0049] A dynamic continuous flow production method of an organosilicon resin according to the present embodiment comprises the following steps:

[0050] (1) The acid catalyst solution, the trialkoxysilane solution and the 20% sodium silicate aqueous solution are pumped into a dynamic tubular reactor 1 with a dynamic stirring and mixing effect, respectively, the feed flow rate of the sulfuric acid catalyst solution is 0.5 L / min; the feed flow rate of the trialkoxysilane solution is adjusted according to the amount added in Table 1; the feed flow rate of the sodium silicate aqueous solution is 1.0 L / min, and the mixture is uniformly mixed and reacted during dynamic stirring (600 rpm), the reaction temperature is controlled to 25° C., and the reaction time is controlled to 120 s to obtain an intermediate reactant.

[0051] (2) The intermediate reactant of step (1) enters the dynamic tubular reactor 2 through a pipeline, and at the same time, a mixed solution of the end-capping agent MM and the isopropanol solvent (ratio of 7:20) is pumped into the dynamic tubular reactor 2 for uniform mixing, the feed flow rate of the mixed solution is 0.85 L / min, a copolymerization reaction occurs, the reaction temperature is controlled to 45° C., and the reaction time is controlled to 10 min to obtain a polymerization solution.

[0052] (3) The polymerization solution of step (2) was mixed with the organic solvent cyclohexane (feed flow rate was 1.5 L / min) and then entered into the equilibrium reactor for reflux reaction at a reaction temperature of 65° C. for 2 h.

[0053] (4) The reactants obtained in step (3) are allowed to stand for stratification, and the upper organic layer is washed twice with concentrated sulfuric acid to remove the waste acid, and then alkali is added for neutralization, and then water is added for dissolution. After separation, the organic silicone resin mother liquor is obtained; the mother liquor is then filtered and concentrated, and sent to a spray dryer with a purge device for drying to obtain MQ silicone resin powder. The solvent evaporated by concentration and drying is condensed and recovered. The lower acid-water layer after standing for stratification is neutralized with alkali, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recycling.

[0054] In order to verify the influence of the trialkoxysilane and the addition amount of the present invention on the gelation in the production process and the molecular weight of the finally obtained MQ silicone resin, the acid catalyst and trialkoxysilane described in Table 1 (the addition amount is calculated as the mass percentage relative to sodium silicate) are respectively used to test the gelation time (accelerated simulation test under the same stirring speed conditions and 45°C conditions with one-time feeding (with a beaker as a reactor)) and the weight average molecular weight of the finally obtained product MQ silicone resin (produced according to the actual process conditions of this embodiment), and the results are shown in Table 1 below.

[0055] Table 1

[0056] Acid Catalyst Trialkoxysilane Gel time MQ Silicone Resin Molecular Weight <![CDATA[37%H 2 SO 4 ]]> 0 1min50s 6052g / mol <![CDATA[37%H 2 SO 4 ]]> 1% Methyltrimethoxysilane 2min30s 5880g / mol <![CDATA[37%H 2 SO 4 ]]> 1.5% Methyltrimethoxysilane 5min10s 5795g / mol <![CDATA[37%H 2 SO 4 ]]> 1.5% Methyltriethoxysilane 6min20s 5570g / mol <![CDATA[37%H 2 SO 4 ]]> 2.5% Methyltrimethoxysilane 8min40s 5638g / mol <![CDATA[37%H 2 SO 4 ]]> 2.5% Methyltriethoxysilane 15min30s 4565g / mol <![CDATA[37%H 2 SO 4 ]]> 3% Methyltrimethoxysilane 10min30s 5460g / mol <![CDATA[37%H 2 SO 4 ]]> 3% Methyltriethoxysilane 18min25s 4269g / mol <![CDATA[37%H 2 SO 4 ]]> 4% Methyltrimethoxysilane 15min40s 5216g / mol <![CDATA[37%H 2 SO 4 ]]> 4% Methyltriethoxysilane 24min20s 4096g / mol <![CDATA[37%H 2 SO 4 ]]> 5% Methyltrimethoxysilane >30min 3250g / mol 37% HCl 3% Methyltrimethoxysilane 10min20s 5482g / mol <![CDATA[37%CH 3 COOH]]> 3% Methyltrimethoxysilane 12min30s 5437g / mol

[0057] It can be seen from the results in Table 1 that the present invention can significantly prolong the gel time by adding a certain amount of trialkoxysilane during the mixed reaction of the acid catalyst solution and the sodium silicate aqueous solution. When the amount of trialkoxysilane added is in the range of 1.5% to 4% by mass of the sodium silicate, the effect of slowing down the gel is significant, and the effect on the molecular weight of the MQ silicone resin is small. In addition, methyltrimethoxysilane has a better comprehensive improvement effect than methyltriethoxysilane.

[0058] Example 4

[0059] A dynamic continuous flow production method of an organosilicon resin according to the present embodiment comprises the following steps:

[0060] (1) A 37% sulfuric acid catalyst solution, a methyltrimethoxysilane solution and a 20% sodium silicate aqueous solution are respectively pumped into a dynamic tubular reactor 1 with a dynamic stirring and mixing effect, the feed flow rate of the sulfuric acid catalyst solution is 0.5 L / min; the feed flow rate of the methyltrimethoxysilane solution is 6 mL / min; the feed flow rate of the sodium silicate aqueous solution is 1.0 L / min, and the mixture is uniformly mixed and reacted during dynamic stirring (600 rpm), the reaction temperature is controlled at 25° C., and the reaction time is controlled at 120 s to obtain an intermediate reactant.

[0061] (2) The intermediate reactant of step (1) enters the dynamic tubular reactor 2 through a pipeline, and at the same time, a mixed solution of the end-capping agent VI-MM and the isopropanol solvent (ratio of 7:20) is pumped into the dynamic tubular reactor 2 for uniform mixing, the feed flow rate of the mixed solution is 0.85 L / min, a copolymerization reaction occurs, the reaction temperature is controlled to 45° C., and the reaction time is controlled to 5 min to obtain a polymerization solution.

[0062] (3) The polymerization solution of step (2) was mixed with the organic solvent toluene (feed flow rate was 1.5 L / min) and then entered into a balanced reactor for reflux reaction at a reaction temperature of 65° C. for 2 h.

[0063] (4) The reactants obtained in step (3) are allowed to stand for stratification, and the upper organic layer is washed twice with concentrated sulfuric acid to remove the waste acid, and then alkali is added for neutralization, and then water is added for dissolution. After separation, the organic silicone resin mother liquor is obtained; the mother liquor is then filtered and concentrated, and sent to a spray dryer with a purge device for drying to obtain VMQ silicone resin powder. The solvent evaporated by concentration and drying is condensed and recovered. The lower acid-water layer after standing for stratification is neutralized with alkali, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recycling.

[0064] The weight average molecular weight of the VMQ silicone resin finally obtained in this example is 5442 g / mol; and the vinyl content is 2.09%.

[0065] Example 5

[0066] A dynamic continuous flow production method of an organosilicon resin according to the present embodiment comprises the following steps:

[0067] (1) A 37% sulfuric acid catalyst solution, a methyltrimethoxysilane solution and a 20% sodium silicate aqueous solution are respectively pumped into a dynamic tubular reactor 1 with a dynamic stirring and mixing effect, the feed flow rate of the sulfuric acid catalyst solution is 0.5 L / min; the feed flow rate of the methyltrimethoxysilane solution is 6 mL / min; the feed flow rate of the sodium silicate aqueous solution is 1.0 L / min, and the mixture is uniformly mixed and reacted during dynamic stirring (600 rpm), the reaction temperature is controlled at 25° C., and the reaction time is controlled at 120 s to obtain an intermediate reactant.

[0068] (2) The intermediate reactant of step (1) enters the dynamic tubular reactor 2 through a pipeline, and at the same time, a mixed solution of the end-capping agent VI-MM and the isopropanol solvent (ratio of 7:20) is pumped into the dynamic tubular reactor 2 for uniform mixing, the feed flow rate of the mixed solution is 0.85 L / min, a copolymerization reaction occurs, the reaction temperature is controlled to 60° C., and the reaction time is controlled to 5 min to obtain a polymerization solution.

[0069] (3) The polymerization solution of step (2) was mixed with the organic solvent xylene (feed flow rate was 1.5 L / min) and then entered into the equilibrium reactor for reflux reaction at a reaction temperature of 65° C. for 2 h.

[0070] (4) The reactants obtained in step (3) are allowed to stand for stratification, and the upper organic layer is washed twice with concentrated sulfuric acid to remove the waste acid, and then alkali is added for neutralization, and then water is added for dissolution. After separation, the organic silicone resin mother liquor is obtained; the mother liquor is then filtered and concentrated, and sent to a spray dryer with a purge device for drying to obtain VMQ silicone resin powder. The solvent evaporated by concentration and drying is condensed and recovered. The lower acid-water layer after standing for stratification is neutralized with alkali, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recycling.

[0071] The weight average molecular weight of the VMQ silicone resin finally obtained in this example is 5356 g / mol; the vinyl content is 2.42%.

[0072] Example 6

[0073] A dynamic continuous flow production method of an organosilicon resin according to the present embodiment comprises the following steps:

[0074] (1) A 37% sulfuric acid catalyst solution, a methyltrimethoxysilane solution and a 20% sodium silicate aqueous solution are respectively pumped into a dynamic tubular reactor 1 with a dynamic stirring and mixing effect, the feed flow rate of the sulfuric acid catalyst solution is 0.5 L / min; the feed flow rate of the methyltrimethoxysilane solution is 6 mL / min; the feed flow rate of the sodium silicate aqueous solution is 1.0 L / min, and the mixture is uniformly mixed and reacted during dynamic stirring (600 rpm), the reaction temperature is controlled at 25° C., and the reaction time is controlled at 120 s to obtain an intermediate reactant.

[0075] (2) The intermediate reactant of step (1) enters the dynamic tubular reactor 2 through a pipeline, and at the same time, a mixed solution of the end-capping agent VI-MM and the isopropanol solvent (ratio of 7:20) is pumped into the dynamic tubular reactor 2 for uniform mixing, the feed flow rate of the mixed solution is 0.85 L / min, a copolymerization reaction occurs, the reaction temperature is controlled to 60° C., and the reaction time is controlled to 10 min to obtain a polymerization solution.

[0076] (3) The polymerization solution of step (2) and the organic solvent MM (feed flow rate is 1.5 L / min) are mixed and then enter into the equilibrium reactor, and refluxed at a reaction temperature of 65° C. for 2 h.

[0077] (4) The reactants obtained in step (3) are allowed to stand for stratification, and the upper organic layer is washed twice with concentrated sulfuric acid to remove the waste acid, and then alkali is added for neutralization, and then water is added for dissolution. After separation, the organic silicone resin mother liquor is obtained; the mother liquor is then filtered and concentrated, and sent to a spray dryer with a purge device for drying to obtain VMQ silicone resin powder. The solvent evaporated by concentration and drying is condensed and recovered. The lower acid-water layer after standing for stratification is neutralized with alkali, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recycling.

[0078] The weight average molecular weight of the VMQ silicone resin finally obtained in this example is 5267 g / mol; the vinyl content is 2.97%.

[0079] Analysis: Examples 4-6 show that for the synthesis and production of VMQ, after the end-capping agent VI-MM is added, appropriately increasing the reaction temperature can promote the end-capping reaction and increase the -VI content. At the same time, appropriately extending the reaction time allows the end-capping agent VI-MM to have sufficient time to react, ensuring sufficient access to the -VI chain segments in the synthesized VMQ resin, and preventing insufficient end-capping from affecting product performance and causing waste of raw materials.

[0080] Example 7

[0081] A dynamic continuous flow production method of an organosilicon resin according to the present embodiment comprises the following steps:

[0082] (1) A 37% hydrochloric acid catalyst solution, a methyltrimethoxysilane solution and a 20% sodium silicate aqueous solution are respectively pumped into a dynamic tubular reactor 1 with a dynamic stirring and mixing effect, the feed flow rate of the hydrochloric acid catalyst solution is 0.65 L / min; the feed flow rate of the methyltrimethoxysilane solution is 6 mL / min; the feed flow rate of the sodium silicate aqueous solution is 1.0 L / min, and the mixture is uniformly mixed and reacted during dynamic stirring (600 rpm), the reaction temperature is controlled at 25° C., and the reaction time is controlled at 120 s to obtain an intermediate reactant.

[0083] (2) The intermediate reactant of step (1) enters the dynamic tubular reactor 2 through a pipeline, and at the same time, a mixed solution of the end-capping agent MM and the isopropanol solvent (ratio of 7:20) is pumped into the dynamic tubular reactor 2 for uniform mixing, the feed flow rate of the mixed solution is 0.85 L / min, a copolymerization reaction occurs, the reaction temperature is controlled to 60° C., and the reaction time is controlled to 10 min to obtain a polymerization solution.

[0084] (3) The polymerization solution of step (2) was mixed with the organic solvent cyclohexane (feed flow rate was 1.5 L / min) and then entered into the equilibrium reactor for reflux reaction at a reaction temperature of 65° C. for 2 h.

[0085] (4) The reactants obtained in step (3) are allowed to stand for stratification, and the upper organic layer is washed twice with concentrated sulfuric acid to remove the waste acid, and then alkali is added for neutralization, and then water is added for dissolution. After separation, the organic silicone resin mother liquor is obtained; the mother liquor is then filtered and concentrated, and sent to a spray dryer with a purge device for drying to obtain MQ silicone resin powder. The solvent evaporated by concentration and drying is condensed and recovered. The lower acid-water layer after standing for stratification is neutralized with alkali, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recycling.

[0086] The weight average molecular weight of the MQ silicone resin finally obtained in this example is 5289 g / mol.

[0087] Example 8

[0088] A dynamic continuous flow production method of an organosilicon resin according to the present embodiment comprises the following steps:

[0089] (1) A 99.8% acetic acid catalyst solution, a methyltrimethoxysilane solution and a 20% sodium silicate aqueous solution are pumped into a dynamic tubular reactor 1 with a dynamic stirring and mixing effect, respectively, the feed flow rate of the acetic acid catalyst solution is 0.6 L / min; the feed flow rate of the methyltrimethoxysilane solution is 6 mL / min; the feed flow rate of the sodium silicate aqueous solution is 1.0 L / min, and the mixture is uniformly mixed and reacted during dynamic stirring (600 rpm), the reaction temperature is controlled at 25° C., and the reaction time is controlled at 120 s to obtain an intermediate reactant.

[0090] (2) The intermediate reactant of step (1) enters the dynamic tubular reactor 2 through a pipeline, and at the same time, a mixed solution of the end-capping agent MM and the isopropanol solvent (ratio of 7:20) is pumped into the dynamic tubular reactor 2 for uniform mixing, the feed flow rate of the mixed solution is 0.85 L / min, a copolymerization reaction occurs, the reaction temperature is controlled to 60° C., and the reaction time is controlled to 10 min to obtain a polymerization solution.

[0091] (3) The polymerization solution of step (2) and the organic solvent MM (feed flow rate is 1.5 L / min) are mixed and then enter into the equilibrium reactor, and refluxed at a reaction temperature of 65° C. for 2 h.

[0092] (4) The reactants obtained in step (3) are allowed to stand for stratification, and the upper organic layer is washed twice with concentrated sulfuric acid to remove the waste acid, and then alkali is added for neutralization, and then water is added for dissolution. After separation, the organic silicone resin mother liquor is obtained; the mother liquor is then filtered and concentrated, and sent to a spray dryer with a purge device for drying to obtain MQ silicone resin powder. The solvent evaporated by concentration and drying is condensed and recovered. The lower acid-water layer after standing for stratification is neutralized with alkali, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recycling.

[0093] The weight average molecular weight of the MQ silicone resin finally obtained in this example is 5234 g / mol.

[0094] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A dynamic continuous flow production method for silicone resin, characterized in that: The steps include: (1) The acid catalyst solution, the trialkoxysilane solution and the sodium silicate aqueous solution are respectively pumped into a dynamic tubular reactor 1 having a dynamic stirring and mixing effect, and are uniformly mixed and reacted during the dynamic rotation stirring process to obtain an intermediate reactant; (2) The intermediate reactant of step (1) enters the dynamic tubular reactor 2 or the microchannel reactor through a pipeline, and at the same time, the mixed solution of the end-capping agent and the organic solvent is pumped into the dynamic tubular reactor 2 or the microchannel reactor for uniform mixing, so that a copolymerization reaction occurs to obtain a polymerization solution; (3) The polymerization solution and the organic solvent in step (2) are mixed and then enter into an equilibrium reactor for the final equilibrium reaction; (4) The reactant obtained in step (3) was allowed to stand for stratification, and the upper organic layer was acid-washed, neutralized, and washed with water to obtain a resin mother liquor, which was filtered, concentrated, and dried to obtain MQ silicone resin powder; The mass concentration of the acid catalyst solution in step (1) is 5% to 100%; the mass concentration of the sodium silicate aqueous solution is 10% to 50%; the flow ratio of the acid catalyst solution to the sodium silicate aqueous solution is 0.05 to 5:0.1 to 10; the amount of trialkoxysilane added is 1.5% to 4% of the mass of the sodium silicate; the reaction temperature of the mixed reaction is controlled to be 0 to 60° C.; and the reaction time is 10 to 600 seconds; The reaction temperature of the copolymerization reaction in step (2) is controlled to be 0-60°C, and the reaction time is controlled to be 5-60min; The weight average molecular weight of the MQ silicone resin finally obtained in step (4) is 2000-30000 g / mol.

2. The dynamic continuous flow production method of a silicone resin according to claim 1, characterized in that: The acid catalyst solution in step (1) is an inorganic acid solution or an organic acid solution, wherein the inorganic acid solution includes at least one of HCl, HClO4, H2SO4 and H3PO4; and the organic acid solution includes at least one of acetic acid, formic acid, propionic acid and p-toluenesulfonic acid.

3. The dynamic continuous flow production method of a silicone resin according to claim 1, characterized in that: The trialkoxysilane solution in step (1) refers to one of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane or phenyltrimethoxysilane.

4. The dynamic continuous flow production method of a silicone resin according to claim 1, characterized in that: The end-capping agent in step (2) is at least one of hexamethyldisiloxane, tetramethyldivinyldisiloxane, tetramethyldiphenyldisiloxane, 1,3-bis(aminopropyl)tetramethyldisiloxane, and tetramethyldisiloxane; the organic solvent in step (2) is at least one of methanol, ethanol, and isopropanol; and the flow ratio of the mixed solution of the end-capping agent and the organic solvent in step (2) to the sodium silicate aqueous solution in step (1) is 0.1-10:0.1-10.

5. The dynamic continuous flow production method of a silicone resin according to claim 1, characterized in that: The organic solvent in step (3) is at least one of MM, toluene, xylene and cyclohexane, and the flow ratio of the organic solvent to the sodium silicate aqueous solution in step (1) is 0.2-5:0.2-5; the conditions of the equilibrium reaction are specifically: reflux reaction at a reaction temperature of 40-80°C for 2-8h.

6. The dynamic continuous flow production method of a silicone resin according to claim 1, characterized in that: The drying in step (4) is carried out using a kettle dryer, a drum dryer, a belt dryer, a fluidized bed dryer, a mechanical stirring dryer and a spray dryer.

7. The dynamic continuous flow production method of a silicone resin according to claim 1, characterized in that: The drying in step (4) is carried out using a spray dryer with a purge device.

8. The dynamic continuous flow production method of a silicone resin according to claim 1, characterized in that: The acid-water layer after standing and stratification in step (4) is neutralized with alkali, and then distilled to recover the organic solvent and water; the remaining saturated salt solution is concentrated and dried for recovery.