A preparation process of organic silicon resin for photocurable coating

Abstract

The present application discloses a preparation process of a silicone resin for photocurable coatings, wherein the raw materials are first added to a mixing device in proportion and mixed evenly, an aeration device is provided at the bottom of the mixing device to obtain a mixed solution; the mixed solution obtained in the mixing kettle is then dripped into a hydrolysis kettle, and co-hydrolyzed with an organic solvent in the hydrolysis kettle to obtain an acidic hydrolyzate; a steam port is provided at the top of the hydrolysis kettle, and the steam port is connected to the aeration device through a reflux pipe; the acidic hydrolyzate is then transported to a water washing tower for water washing to obtain a neutral primary polycondensate; and finally, it is concentrated and polycondensed to obtain a finished product. The present application has the effect of recycling the steam generated by hydrolysis.

Description

Technical Field

[0001] The invention relates to the field of preparation of organic silicon resin, in particular to a preparation process of organic silicon resin dedicated to photocurable coatings. Background Art

[0002] Silicone resin and modified silicone resin products are widely used in defense and military industry, electrical industry, leather industry, light industrial products, rubber and plastics, food hygiene and other industries due to their excellent thermal oxidation stability, electrical insulation performance, weather resistance, waterproof, salt spray resistance, mildew resistance, biocompatibility and other characteristics, playing an irreplaceable role. In the preparation process of silicone resin, hydrolysis generates a large amount of heat, which causes the solution in the hydrolysis to evaporate, and the steam is discharged from the system for condensation and then collected for treatment, which is inconvenient to handle and causes energy waste.

[0003] With respect to the above-mentioned related technologies, the applicant believes that the following defects exist: the steam generated by hydrolysis is inconvenient to handle. Summary of the invention

[0004] In order to recycle the steam generated by hydrolysis, the present application provides a preparation process of an organosilicon resin dedicated to photocurable coatings.

[0005] The present application provides a preparation process of a silicone resin for photocurable coatings using the following technical solution:

[0006] A process for preparing a silicone resin for photocurable coatings comprises the following steps:

[0007] S1. Add the raw materials into a mixing device in proportion and mix them evenly. An aeration device is provided at the bottom of the mixing device to obtain a mixed liquid;

[0008] S2, injecting the mixed solution obtained in the mixing kettle into the hydrolysis kettle, hydrolyzing in the hydrolysis kettle to obtain an acidic hydrolyzate; the upper part of the hydrolysis kettle is provided with a steam port, and the steam port is connected to the aeration device through a reflux pipe;

[0009] S3, transporting the acidic hydrolyzate to a water washing tower for water washing to obtain a neutral primary polycondensate;

[0010] S4, conveying the concentrated polymer to a polycondensation device for polycondensation treatment to obtain a finished product.

[0011] By adopting the above technical scheme, the steam generated in the hydrolysis kettle is discharged from the steam port into the reflux pipe, then enters the aeration device through the reflux pipe, and is sprayed from the aeration device to the raw materials in the mixing equipment. The aeration disturbs the position of the mixed raw materials, so that the raw materials are mixed more evenly, and the raw materials can reduce the temperature of the steam, so that the steam is liquefied and mixed into the raw materials, and returns to the hydrolysis kettle with the raw materials again, thereby realizing the recycling of the steam generated by hydrolysis, saving resources, and facilitating the treatment of the steam generated by hydrolysis.

[0012] Preferably, the mixing equipment includes a cylinder, the aeration device is installed at the bottom of the cylinder, the aeration device includes a pipeline and multiple aeration shafts, the pipeline is fixedly connected to the cylinder, the pipeline is connected to the return pipe, and multiple aeration shafts are respectively installed on the pipeline, and an air supply hole and a plurality of aeration holes are provided in the aeration shaft, one end of the air supply hole is connected to the pipeline, and both ends of the aeration hole are respectively connected to the air supply hole and the outer wall of the aeration shaft.

[0013] By adopting the above technical solution, the steam is distributed to various places of the cylinder through pipelines and multiple aeration shafts, thereby expanding the aeration range, increasing the disturbance range of each raw material, and improving the mixing efficiency of each raw material.

[0014] Preferably, the lower end of the aeration shaft is rotatably connected to the pipeline, and the reaction force of the gas ejected from the aeration holes drives the rotating shaft to rotate, and a plurality of stirring blades are installed on the aeration shaft.

[0015] By adopting the above technical solution, the aeration shaft is driven to rotate by steam, thereby driving the stirring blades to rotate, so that the raw materials are more fully stirred. At the same time, the rotation of the aeration shaft makes the range of gas ejected from the aeration holes wider, so that the raw materials can be more fully mixed.

[0016] Preferably, a storage bin is installed in the cylinder, the storage bin is arranged at the upper part of the cylinder and seals the upper part of the cylinder, the storage bin is divided into a plurality of storage compartments, the plurality of storage compartments respectively store a plurality of raw materials, and the storage bin is made of a material with good thermal conductivity.

[0017] By adopting the above technical solution, the storage bin is used to store various raw materials. At the same time, part of the steam passes through the raw materials in the cylinder and rises to the storage bin. The temperature of the raw materials in the storage bin is lower than that of the raw materials in the cylinder. The steam exchanges heat with the storage bin and liquefies and falls back.

[0018] Preferably, a receiving tray with a middle protrusion is installed below the storage bin, the edge of the receiving tray is fixed to the inner wall of the cylinder to form a seal, the receiving tray is provided with a plurality of air vents, a leak-proof ring is provided around the air vent, an inclined baffle is provided above the air vent, one end of the baffle is fixed to one side of the air vent, the receiving tray is connected to a drain pipe, and the drain pipe is connected to the bottom of the hydrolysis kettle.

[0019] By adopting the above technical solution, the receiving tray collects the liquid that has liquefied and fallen back in the storage bin and discharges it back into the hydrolysis kettle, and is used again for hydrolysis in the hydrolysis kettle.

[0020] Preferably, a cooling device is installed on the cylinder, and the cooling device is connected to the side wall of the storage bin via a heat conducting plate. The heat conducting plate is fixedly connected to the side wall of the storage bin and can exchange heat with the heat conducting plate. The inner wall of the storage bin is provided with a heat insulating layer.

[0021] By adopting the above technical solution, the cooling device cools the side wall of the storage bin, so that the steam rising to the storage bin is more easily condensed and liquefied, and the insulation layer can reduce the temperature loss of the side wall of the storage bin.

[0022] Preferably, the cooling device comprises a liquid nitrogen tank, a liquid nitrogen pipe and a nozzle, the nitrogen tank is filled with liquid nitrogen, the nitrogen tank is provided with a liquid nitrogen outlet, the liquid nitrogen outlet is equipped with a liquid nitrogen valve, the two ends of the liquid nitrogen pipe are respectively connected to the liquid nitrogen outlet and the nozzle, and the nozzle is fixed on the outer wall of the cylinder and faces the heat conduction plate.

[0023] By adopting the above technical solution, the storage bin is cooled by liquid nitrogen, which is easy to control, not prone to failure, has a long service life, is easy to modify, and has low cost.

[0024] Preferably, the aeration device further comprises a water pump, the water outlet of the water pump is connected to the pipeline, the water inlet of the water pump is connected to the lower part of the cylinder, and a valve is installed in the return pipe.

[0025] By adopting the above technical solution, when the amount of steam in the hydrolysis kettle is small, the valve is closed and the water pump is started. The water pump sucks the solution at the bottom of the cylinder and then sprays it out from the aeration hole. The solution sucked into the bottom of the cylinder by the water pump will disturb the raw materials in the cylinder, and the sprayed water column will also disturb the raw materials in the cylinder, while driving the stirring shaft to rotate, so that the raw materials can be stirred faster and more evenly.

[0026] In summary, the present application includes at least one of the following beneficial technical effects:

[0027] 1. The steam generated in the hydrolysis kettle is discharged from the steam port into the reflux pipe, and then enters the aeration device through the reflux pipe, and is sprayed from the aeration device to the raw materials in the mixing device. The aeration disturbs the position of the mixed raw materials, so that the raw materials are mixed more evenly, and the raw materials can reduce the temperature of the steam, so that the steam is liquefied and mixed into the raw materials, and then returns to the hydrolysis kettle with the raw materials, so as to realize the recycling of the steam generated by hydrolysis, save resources, and facilitate the treatment of the steam generated by hydrolysis;

[0028] 2. The aeration shaft is driven to rotate by steam, thereby driving the stirring blades to rotate, so that the raw materials are more fully stirred. At the same time, the rotation of the aeration shaft makes the gas ejected from the aeration holes have a wider range, so that the raw materials can be more fully mixed. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic flow chart of a process for preparing a silicone resin specially used for a photocurable coating according to an embodiment of the present application.

[0030] Figure 2 It is a schematic diagram of the connection between the mixing device and the hydrolysis kettle in the embodiment of the present application.

[0031] Figure 3 It is a schematic diagram of the structure of the mixing device of an embodiment of the present application.

[0032] Figure 4 It is a schematic diagram of the structure of the aeration shaft of an embodiment of the present application.

[0033] Figure 5 It is a schematic top view of the aeration shaft of an embodiment of the present application.

[0034] Description of reference numerals:

[0035] 1. Mixing equipment; 11. Cylinder; 2. Hydrolysis kettle; 3. Aeration device; 31. Pipeline; 32. Aeration shaft; 33. Stirring blade; 34. Water pump; 35. Aeration hole; 36. Gas transmission hole; 4. Reflux pipe; 5. Drain pipe; 6. Receiving tray; 7. Leakage ring; 8. Baffle; 9. Cooling device; 91. Liquid nitrogen tank; 92. Liquid nitrogen pipe; 93. Nozzle; 94. Heat transfer plate; 10. Storage bin. DETAILED DESCRIPTION

[0036] The following is combined with Figure 1-5 This application is described in further detail.

[0037] The embodiment of the present application discloses a process for preparing a silicone resin specifically for photocurable coatings.

[0038] Reference Figure 1 and Figure 2 A process for preparing a silicone resin for a photocurable coating comprises the following steps:

[0039] S1. Add raw materials into a mixing device 1 in proportion, and add an organic solvent into the mixing device 1 so that the raw materials are evenly mixed in the organic solvent. An aeration device 3 is provided at the bottom of the mixing device 1 to obtain a mixed liquid. The raw materials include two or more organic silicon monomer materials selected from dimethyldichlorosilane, diphenyldichlorosilane, monomethyltrichlorosilane and monophenyltrichlorosilane, and one or more organic silicon monomer materials selected from methylvinyldichlorosilane, methylhydrogendichlorosilane and silane coupling agent organic silicon monomer.

[0040] S2, injecting the mixed liquid obtained in the mixing kettle into the hydrolysis kettle 2, the upper part of the hydrolysis kettle 2 is provided with a steam port, and the steam port is connected to the aeration device 3 through a reflux pipe 4. The hydrolysis kettle 2 is filled with an aqueous solution containing ether, ketone or ester. After the mixed liquid is injected, it is co-hydrolyzed with the aqueous solution in the hydrolysis kettle 2 to obtain an acidic hydrolyzate. Since a large amount of heat is generated by hydrolysis, the temperature in the hydrolysis kettle 2 rises rapidly, and a large amount of steam is generated in the hydrolysis kettle 2. The steam enters the aeration device 3 through the reflux pipe 4, and then enters the mixed liquid in the mixing device 1 from the aeration device 3.

[0041] S3, conveying the acidic hydrolyzate to a water washing tower for washing 3-5 times to obtain a neutral primary polycondensate. The primary polycondensate obtained by washing is conveyed to a concentration device for concentration to obtain a concentrated polycondensate.

[0042] S4. The concentrated polymer is transported to a polycondensation device, and a mixture of one or more monomers selected from the group consisting of methacrylic acid, acrylic acid, methyl acrylate, methyl methacrylate, hydroxypropyl acrylate, hydroxyethyl acrylate, dihydroxy acrylate, ethylene glycol acrylate, maleic anhydride and fumaric anhydride is introduced into the polycondensation device. Under the action of a catalyst, the mixture is heated and pressurized to react for polycondensation treatment. Then, under negative pressure, low molecular weight monomers and solvents are removed to obtain a finished product.

[0043] Reference Figure 3 , Figure 4 and Figure 5The mixing device 1 includes a cylinder 11, and an aeration device 3 is installed at the bottom of the cylinder 11. The aeration device 3 includes a pipeline 31 and a plurality of aeration shafts 32. The pipeline 31 is fixedly connected to the inner wall of the cylinder 11. One end of the reflux pipe 4 away from the hydrolysis kettle 2 is fixedly connected to the cylinder 11 and connected to the pipeline 31. The plurality of aeration shafts 32 are evenly distributed at the bottom of the cylinder 11 and arranged above the pipeline 31. The lower ends of the aeration shafts 32 are rotatably connected to the pipeline 31 through sealed bearings. The aeration shaft 32 is provided with a gas delivery hole 36 and a plurality of aeration holes 35. One end of the gas delivery hole 36 is connected to the pipeline 31. The two ends of the aeration hole 35 are respectively connected to the gas delivery hole 36 and the outer wall of the aeration shaft 32. The axis of the opening of the aeration hole 35 located on the outer wall of the aeration shaft 32 is substantially tangent to the outer wall of the aeration shaft 32 at the opening of the aeration hole 35. The reaction force of the gas ejected from the aeration hole 35 causes the rotating shaft to rotate. A plurality of stirring blades 33 are installed on the aeration shaft 32. The aeration shaft 32 drives the stirring blades 33 to rotate, so that the stirring blades 33 stir the mixed liquid, and the mixed liquid is mixed more evenly. The gas ejected from the aeration hole 35 disturbs the mixed liquid, so that the mixed liquid is mixed more evenly, realizing the energy reuse of the steam in the hydrolysis kettle 2. At the same time, the steam in the hydrolysis kettle 2 is recovered and enters the hydrolysis kettle 2 again. Since the steam is effectively recovered and reused, the mixed liquid can be quickly injected into the hydrolysis kettle 2 without using a less efficient drop-wise method to drip the mixed liquid into the hydrolysis kettle 2, thereby effectively improving the hydrolysis efficiency of the hydrolysis kettle 2.

[0044] Reference Figure 3 The aeration device 3 also includes a water pump 34, which is fixed to the outer wall of the cylinder 11. The water outlet of the water pump 34 is connected to the pipe 31, and the water inlet of the water pump 34 is connected to the lower part of the cylinder 11. The water pump 34 can suck the mixed liquid in the cylinder 11, and then spray it out from the aeration hole 35 through the pipe 31 and the aeration shaft 32, so that the mixed liquids disturb each other and mix more evenly. A valve is installed in the reflux pipe 4. When the water pump 34 is working, the valve is closed to prevent the mixed liquid from entering the hydrolysis kettle 2 through the reflux pipe 4; when the amount of steam is small and the steam cannot drive the aeration shaft 32 to rotate, the valve is closed, and the water pump 34 is used to suck the mixed liquid to drive the aeration shaft 32 to rotate.

[0045] Reference Figure 3A storage bin 10 is installed in the cylinder 11. The storage bin 10 is pot-shaped and made of steel. The storage bin 10 is arranged at the upper part of the cylinder 11 and seals the upper part of the cylinder 11. The storage bin 10 is divided into a plurality of storage compartments by partitions. The plurality of storage compartments respectively store two or more organic silicon monomer materials selected from dimethyldichlorosilane, diphenyldichlorosilane, monomethyltrichlorosilane and monophenyltrichlorosilane, and one or more organic silicon monomer materials selected from methylvinyldichlorosilane, methylhydrogendichlorosilane and silane coupling agent organic silicon monomer. A receiving tray 6 convex toward the middle is installed below the storage bin 10. The edge of the receiving tray 6 is fixed to the inner wall of the cylinder 11 and forms a seal. The receiving tray 6 is provided with three vents, which are symmetrically arranged. A convex leak-proof ring 7 is provided around the vents. The leak-proof ring 7 prevents the liquid flowing on the surface of the receiving tray 6 from entering the vents. An inclined baffle 8 is provided above the vents. The baffle 8 is larger than the vents and covers the vents vertically. One end of the baffle 8 is fixed to one side of the vents. The baffle 8 prevents the falling condensed liquid from falling through the vents to the bottom of the receiving tray 6. A drain pipe 5 is connected to one side of the receiving tray 6, and the drain pipe 5 is connected to the bottom of the hydrolysis kettle 2. Each storage compartment is connected to a feed pipe, the lower end of which is connected to the lower part of the cylinder 11 and is located below the receiving tray 6. A feed valve is installed in the feed pipe. When the raw materials need to be put into the cylinder 11 for mixing, the feed valve is opened, and the raw materials automatically fall into the cylinder 11 below the feed pipe through the feed pipe. After the feed is discharged, the feed valve is closed to separate the storage compartment from the space in the cylinder 11. Part of the steam emerges from the mixed liquid, rises, passes through the vent and enters between the receiving tray 6 and the storage bin 10, and then continues to rise and contact the storage bin 10. Since the storage bin 10 stores raw materials, the temperature of the raw materials is lower than the temperature of the steam. After rising to the storage bin 10, the steam contacts the storage bin 10 with a lower temperature and is liquefied, falling back onto the receiving tray 6. After being collected by the receiving tray 6, it is transported back to the hydrolysis kettle 2 through the discharge pipe 5 and used for hydrolysis in the hydrolysis kettle 2 again.

[0046] Reference Figure 3In another embodiment, in order to make the steam easier to liquefy, a cooling device 9 is installed on the cylinder 11. The cooling device 9 is connected to the storage bin 10 through a heat conducting plate 94. The heat conducting plate 94 has good thermal conductivity. The cooling device 9 and the storage bin 10 exchange heat through the heat conducting plate 94 to reduce the temperature of the storage bin 10. The inner wall of the storage bin 10 is provided with a heat insulating layer. The heat insulating layer disconnects the heat transfer between the side wall of the storage bin 10 and the raw materials, reducing the temperature loss of the side wall of the storage bin 10. The cooling device 9 includes a liquid nitrogen tank 91, a liquid nitrogen pipe 92 and a nozzle 93. One end of the heat conducting plate 94 is fixedly connected to the side wall of the storage bin 10 and can exchange heat with the heat conducting plate 94. The nitrogen tank is filled with liquid nitrogen, and the nitrogen tank is provided with a liquid nitrogen outlet, and a liquid nitrogen valve is installed at the liquid nitrogen outlet, and a liquid nitrogen pipe 92 is connected to the liquid nitrogen pipe 92, and one end of the liquid nitrogen pipe 92 away from the liquid nitrogen tank 91 is connected to a nozzle 93, and the nozzle 93 is fixed on the outer wall of the cylinder 11 and faces the heat conduction plate 94. When the liquid nitrogen valve is opened, the liquid nitrogen passes through the liquid nitrogen pipe 92 and is sprayed from the nozzle 93, sprayed onto the heat conduction plate 94, and performs heat exchange with the heat conduction plate 94, so that the heat conduction plate 94 is cooled down, and the heat conduction plate 94 performs heat exchange with the storage bin 10, and the temperature of the storage bin 10 is reduced.

[0047] The implementation principle of the preparation process of a silicone resin for photocurable coatings in the embodiment of the present application is as follows: the steam generated in the hydrolysis kettle 2 is discharged from the steam port into the reflux pipe 4, then enters the aeration device 3 through the reflux pipe 4, and is sprayed from the aeration device 3 into the mixed liquid in the mixing device 1. The aeration disturbs the mixed liquid so that the components in the mixed liquid are mixed more evenly, and the mixed liquid can reduce the temperature of the steam, so that part of the steam is liquefied and mixed into the mixed liquid, and then returns to the hydrolysis kettle 2 with the mixed liquid. The steam that has not been liquefied continues to rise to the storage bin 10, is liquefied after heat exchange with the storage bin 10, falls back to the receiving tray 6, and then returns to the hydrolysis kettle 2 through the discharge pipe 5. The steam generated by hydrolysis is recycled, resources are saved, and the steam generated by hydrolysis is easy to handle, so that the mixed liquid can quickly enter the hydrolysis kettle 2, instead of entering the hydrolysis kettle 2 by dripping a small amount, thereby improving the efficiency of the hydrolysis process section.

[0048] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A process for preparing a silicone resin for photocurable coatings, characterized in that: The steps include: S1, adding raw materials into a mixing device (1) in proportion and mixing them evenly, an aeration device (3) is provided at the bottom of the mixing device (1), to obtain a mixed liquid; S2, injecting the mixed liquid obtained in the mixing kettle into the hydrolysis kettle (2), hydrolyzing in the hydrolysis kettle (2) to obtain an acidic hydrolyzate; the upper part of the hydrolysis kettle (2) is provided with a steam port, and the steam port is connected to the aeration device (3) through a reflux pipe (4); S3, transporting the acidic hydrolyzate to a water washing tower for water washing to obtain a neutral primary polycondensate; S4, transporting the concentrated polymer to a polycondensation device for polycondensation treatment to obtain a finished product; The mixing device (1) comprises a cylinder (11), the aeration device (3) is installed at the bottom of the cylinder (11), the aeration device (3) comprises a pipeline (31) and a plurality of aeration shafts (32), the pipeline (31) is fixedly connected to the cylinder (11), the pipeline (31) is connected to the return pipe (4), the plurality of aeration shafts (32) are respectively installed on the pipeline (31), an air delivery hole (36) and a plurality of aeration holes (35) are provided in the aeration shaft (32), one end of the air delivery hole (36) is connected to the pipeline (31), and the two ends of the aeration hole (35) are respectively connected to the air delivery hole (36) and the outer wall of the aeration shaft (32); The lower end of the aeration shaft (32) is rotatably connected to the pipeline (31), and the two ends of the aeration hole (35) are respectively connected to the gas transmission hole (36) and the outer wall of the aeration shaft (32), and the axis of the opening of the aeration hole (35) located on the outer wall of the aeration shaft (32) is substantially tangent to the outer wall of the aeration shaft (32) at the opening of the aeration hole (35), and the reaction force of the gas ejected from the aeration hole (35) drives the aeration shaft (32) to rotate, and a plurality of stirring blades (33) are installed on the aeration shaft (32).

2. The process for preparing a silicone resin for photocurable coatings according to claim 1, characterized in that: A storage bin (10) is installed in the cylinder (11). The storage bin (10) is arranged at the upper part of the cylinder (11) and seals the upper part of the cylinder (11). The storage bin (10) is divided into a plurality of storage compartments, and the plurality of storage compartments respectively store a plurality of raw materials. The storage bin (10) is made of a material with good thermal conductivity.

3. The process for preparing a silicone resin for photocurable coatings according to claim 2, characterized in that: A receiving tray (6) with a central protrusion is installed below the storage bin (10), the edge of the receiving tray (6) is fixed to the inner wall of the cylinder (11) to form a seal, the receiving tray (6) is provided with a plurality of vents, a leak-proof ring (7) is provided around the vents, an inclined baffle (8) is provided above the vents, one end of the baffle (8) is fixed to one side of the vents, the receiving tray (6) is connected to a drain pipe (5), and the drain pipe (5) is connected to the bottom of the hydrolysis kettle (2).

4. The process for preparing a silicone resin for photocurable coatings according to claim 2, characterized in that: A cooling device (9) is installed on the cylinder (11); the cooling device (9) is connected to the side wall of the storage bin (10) via a heat conducting plate (94); the heat conducting plate (94) is fixedly connected to the side wall of the storage bin (10) and is capable of heat exchange with the heat conducting plate (94); and the inner wall of the storage bin (10) is provided with a heat insulating layer.

5. The process for preparing a silicone resin for photocurable coatings according to claim 4, characterized in that: The cooling device (9) comprises a liquid nitrogen tank (91), a liquid nitrogen pipe (92) and a nozzle (93); the liquid nitrogen tank (91) is filled with liquid nitrogen; the liquid nitrogen tank (91) is provided with a liquid nitrogen outlet; the liquid nitrogen outlet is provided with a liquid nitrogen valve; two ends of the liquid nitrogen pipe (92) are respectively connected to the liquid nitrogen outlet and the nozzle (93); the nozzle (93) is fixed on the outer wall of the cylinder (11) and faces the heat conducting plate (94).

6. The process for preparing a silicone resin for photocurable coatings according to claim 1, characterized in that: The aeration device (3) further comprises a water pump (34), the water outlet of the water pump (34) being connected to the pipeline (31), the water inlet of the water pump (34) being connected to the lower part of the cylinder (11), and a valve being installed in the return pipe (4).

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