Low-molecular-weight polyphenyl ether preparation system
By using a modular production system with stepwise washing and gradual devolatilization processes, the problems of excessive solvent use and particle size control in the preparation of low molecular weight polyphenylene ethers have been solved, resulting in polyphenylene ether products with high purity and good processing performance.
Patent Information
- Application Number
- CN202423291986.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing technologies require the use of large amounts of unsuitable solvents when preparing low molecular weight polyphenylene ethers, leading to product loss and equipment contamination. Furthermore, it is difficult to control particle size and metal ion content, which affects product performance and processing performance.
By employing a stepwise washing and gradual devolatilization method, and through a modular production system including a reaction unit, a washing unit, a concentration unit, and a drying unit, the amount of solvent used is reduced, and the particle size and metal ion content are controlled through a continuous production process.
This technology enables controllable particle size and low metal content in low molecular weight polyphenylene ethers, improving product purity and processing performance while reducing solvent usage and equipment contamination.
Smart Images
Figure CN223490963U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of polyphenylene ether preparation apparatus, and specifically to a low molecular weight polyphenylene ether preparation system. Background Technology
[0002] With the rapid development of the information industry, higher requirements have been placed on the matrix resins used in copper clad laminates, demanding low dielectric constant, low dielectric loss, high glass transition temperature, high heat resistance, and low water absorption. Epoxy resin is the most widely used matrix resin in the copper clad laminate manufacturing industry, but it suffers from poor dimensional stability at high temperatures and an excessively high dielectric constant in the high-frequency range, failing to meet the needs of technological development.
[0003] Polyphenylene oxide (PPO) resin possesses excellent overall properties, particularly its high glass transition temperature and superior dielectric properties, making it an ideal alternative to high-performance copper-clad laminate substrates. PPO also exhibits excellent low dielectric properties, heat resistance, and dimensional stability, and can be manufactured using the same processes and equipment as traditional epoxy resin-based copper-clad laminates, demonstrating significant potential for applications in high-speed, high-frequency electronic devices.
[0004] However, due to the high molecular weight and few reactive groups of commercially available PPO, it is difficult to self-cure or composite with other resins for curing, thus preventing the full realization of PPO's performance advantages in the copper-clad laminate (CCL) field. Furthermore, the significant differences in chemical structure and properties between high molecular weight polyphenylene ether (PPO) and epoxy resin lead to poor compatibility and phase separation after curing, making the use of traditional high molecular weight PPO as a matrix resin for CCLs quite challenging.
[0005] Compared with general high molecular weight polyphenylene ether, low molecular weight dihydroxy polyphenylene ether not only retains the original excellent properties of polyphenylene ether, but also has the advantages of low viscosity, good flowability, good compatibility with many resins, and good thermal properties at the glass transition temperature. It is suitable as a matrix resin or other polymer material additive for composite materials such as high frequency circuit boards.
[0006] In the post-treatment of the reaction solution in related technologies, a large amount of undesirable solvent is often added for precipitation. This method uses a large amount of undesirable solvent, sometimes requiring ten times the amount of the reaction solution. Furthermore, the oligomer portion of the prepared low molecular weight polyphenylene ether still dissolves in the solution, leading to product loss, poor processing performance, and small particle size and low bulk density in the resulting sample, which is not conducive to downstream dissolution and use. In solvent extraction schemes, devolatilization is performed using an extruder at 200-300℃. This easily causes rearrangement or hydroxyl oxidation of the polyphenylene ether, and the friction of the equipment can easily introduce metal ions during the process, leading to thermal decomposition and placing high demands on the equipment. Utility Model Content
[0007] This invention addresses the problems of introducing large amounts of undesirable solvents and high molecular weight in the reaction apparatus of polyphenylene ether, and provides a low molecular weight polyphenylene ether preparation system. The system adopts a stepwise washing and gradual devolatilization method to reduce the amount of solvent used, reduce the oxidation of terminal hydroxyl groups, and obtain low molecular weight polyphenylene ether with controllable particle size.
[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0009] A low molecular weight polyphenylene ether preparation system includes a reaction unit A, a washing unit B, a concentration unit C, and a drying unit D connected in sequence by pipes.
[0010] The washing unit B includes a washing extraction tower B1 and a washing extraction tower B2. The inlet of the washing extraction tower B1 is connected to the outlet of the reaction unit A, the outlet of the washing extraction tower B1 is connected to the inlet of the washing extraction tower B2, and the outlet pipe of the washing extraction tower B2 is connected to the concentration unit C.
[0011] The concentration unit C includes a falling film evaporator C1, a falling film evaporator C2, and a scraped evaporator C3; the inlet of the falling film evaporator C1 is connected to the washing extraction tower B2 and the outlet is connected to the inlet of the falling film evaporator C2; the outlet pipe of the falling film evaporator C2 is connected to the scraped evaporator C3; and the outlet pipe of the scraped evaporator C3 is connected to the product drying unit D.
[0012] The drying unit D includes a belt dryer D1, a product pulverizer D2, and a spiral continuous dryer D3; the inlet pipe of the belt dryer D1 is connected to the scraper evaporator C3 and the outlet is connected to the product pulverizer D2, and the outlet of the product pulverizer D2 is connected to the spiral continuous dryer D3.
[0013] Preferably, the reaction unit includes a reaction vessel A1 and a reaction liquid buffer vessel A2, the outlet of the reaction vessel A1 is connected to the reaction liquid buffer vessel A2, and the outlet of the reaction liquid buffer vessel A2 is connected to the washing unit B.
[0014] Preferably, the reaction vessel A1 is equipped with a raw material feeding metering device and an oxygen distributor; the reaction liquid buffer vessel A2 has a cooling function.
[0015] Preferably, the reaction unit A is an intermittent operation, and the unit consists of a washing unit B, a concentration unit C, and a drying unit D.
[0016] Preferably, the exhaust gas outlets of the concentration unit C and the drying unit D are connected to a falling film evaporator E2 for recovering the reaction solvent; the gas phase outlet pipe of the falling film evaporator E2 is connected to a vacuum pump.
[0017] Preferably, the waste liquid from the washing unit B2 is connected to the high gravity distillation recovery unit E1 for recovering the washing solvent;
[0018] Preferably, a packaging unit is provided after the drying unit D for packaging the products.
[0019] Preferably, the product crusher D2 outlet is equipped with a screen.
[0020] Compared with the prior art, the present invention has the following beneficial effects:
[0021] This invention utilizes modular production and a continuous post-processing technology to avoid the use of precipitants and reduce solvent usage. Products produced using this system have a narrow polyphenylene ether distribution, low metal content, and controllable particle size. Attached Figure Description
[0022] Figure 1 A schematic diagram of the low molecular weight polyphenylene ether preparation system of this invention.
[0023] Figure 2 The image shows the GPC diagram of the low molecular weight polyphenylene ether prepared in Example 1. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this utility model, without departing from the spirit and scope of the technical solutions of this utility model, should all be covered within the protection scope of this utility model.
[0025] Example 1
[0026] Adopting such Figure 1 The apparatus shown is used to prepare low molecular weight polyphenylene ether, specifically including the following steps:
[0027] (1) Addition of reaction raw materials: 14300g of 2,6-xylenol monomer and 3167g of tetramethylbisphenol A (TMBPA) were added to reactor A1 through the silo by loss-in-weight weighing. 42000g of toluene was delivered to reactor A1 under flow control. 167g of copper catalyst prepared on site was added to reactor A1 by weighing and metering. Oxygen was delivered from outside the boundary to the workshop through pipeline and sent to reactor A1 under a certain flow control.
[0028] (2) Polymerization stage: Start the stirring in reactor A1 at a speed of 100 rpm. Introduce 90°C hot water into the jacket of reactor A1 to raise the internal temperature to 40°C. Once the reaction temperature is reached, continuously add oxygen using a gas flow meter. Remove the heat generated by the reaction by circulating cooling water. The reaction time is 5 hours. To ensure safe venting of the reactor, nitrogen is used to dilute the vent gas.
[0029] After the reaction is completed, the reaction liquid in reactor A1 is transferred to reaction liquid buffer vessel A2. Circulating cooling water is introduced into the jacket of reaction liquid buffer vessel A2 to maintain the temperature inside the vessel below 30°C, and reactor A1 can restart the batch reaction process of (1) and (2).
[0030] (3) Washing stage: The prepared aqueous solution containing 10% NTA (terminating agent) is added to the extraction tower from the upper part of the washing extraction tower B1 using a metering pump. The reaction liquid in the reaction buffer tank A2 is added to the extraction tower from the lower part of the washing extraction tower B1 through a flow meter. The residence time of the reaction liquid in the washing extraction tower B1 is about 60 minutes. The light phase contains a mixed solution of low molecular weight PPO, unreacted phenol and toluene, and the heavy phase contains a mixture of water and catalyst chelate and some free amine. The light phase is sent to the washing extraction tower B2, and the heavy phase is sent to the wastewater treatment unit for further treatment.
[0031] A prepared aqueous solution containing 40% methanol is added to the extraction tower from the upper part of the washing and extraction tower B2 using a metering pump. The reaction solution from the washing and extraction tower B1 is added to the extraction tower from the lower part of the washing and extraction tower B2 using a flow meter. The residence time of the reaction solution in the washing and extraction tower B2 is approximately 60 minutes. The light phase contains a mixed solution of low molecular weight PPO and toluene, and the heavy phase contains a mixture of water, methanol, and phenol. The light phase is sent to the falling film evaporator C1, and the heavy phase is sent to the ultragravity distillation unit E1 for solvent recovery.
[0032] (4) Product concentration: The reaction liquid from the washing and extraction tower B2 enters the falling film evaporator C1 and then enters the evaporator separation tank. The solution in the evaporator separation tank is circulated to the evaporator preheater by a pump and heated by steam. After heating, flash evaporation continues in the tank. The temperature of the falling film evaporator is 85℃ and the pressure is -70kPa. The polymer solution that reaches a suitable concentration enters the falling film evaporator C2 for further concentration. The evaporated toluene is condensed and then sent to the toluene storage tank for further processing in the falling film evaporator E2.
[0033] The polymer solution from falling film evaporator C1 enters falling film evaporator C2 for further concentration; the temperature of falling film evaporator C2 is 95℃ and the pressure is -80kPa; when the polymer solution reaches a suitable concentration, it enters scraped film evaporator C3 for further concentration, and the evaporated toluene is sent to toluene storage tank for further processing in falling film evaporator E2 after condensation.
[0034] The polymer solution from the falling film evaporator C2 enters the scraped film evaporator C3. The main circulating liquid flow merges and enters the scraped film evaporator C3, where it is heated and then subjected to devolatilization. The temperature of the scraped film evaporator C3 is 110℃ and the pressure is -90kPa. After the polymer solution reaches a suitable concentration, it enters the belt dryer D1 for foaming and drying. The evaporated toluene is condensed and then sent to the toluene storage tank for further processing in the falling film evaporator E2.
[0035] (5) Product Drying: The high-concentration polymer solution from the scraped film evaporator C3 is pumped into the belt dryer D1 via a screw pump for foaming and devolatilization drying. The temperature of the belt dryer D1 is controlled at 120℃, the pressure is <-99kPa, and the residence time of the material in the belt dryer D1 is 1.5h. After foaming and devolatilization drying in the belt dryer D1, the polymer is in the form of sheet-like solids, and the residual polymer solvent content is <5%.
[0036] The polymer, after foaming and devolatilization drying in belt dryer D1, is conveyed by a screw conveyor to product pulverizer D2. After being crushed into particles of suitable size in product pulverizer D2, the particles pass through a sieve plate and enter belt continuous dryer D3 for further drying. The temperature in belt continuous dryer D3 is 120℃, the pressure is <-99kPa, and the material residence time in belt dryer D1 is 6-8 hours. The polymer solvent residue is <0.1%. The dried polymer particles are then sent to a product packaging machine for packaging. Figure 2 As shown, the molecular weight of the polymer product was 2952 as determined by GPC, achieving the preparation of low molecular weight polyphenylene ether with uniform particle size, iron ion content of 3.3 ppm, copper ion content of 4 ppm, low impurities, and high purity.
[0037] (6) Solvent recovery: The solvent returned from product drying and product concentration is recycled to reactor A1 for reuse after the high waste brought into the system is removed by falling film evaporator E2.
[0038] The methanol-containing aqueous solution in the self-washing extraction tower B2 is recycled to the washing extraction tower B2 after being purified by gravity distillation to increase the methanol concentration to 80%. The wastewater in the tower bottom is sent to the wastewater treatment plant.
Claims
1. A low molecular weight polyphenylene ether preparation system, characterized in that, It includes reaction unit A, washing unit B, concentration unit C, and drying unit D connected in sequence by pipelines; The washing unit B includes a washing extraction tower B1 and a washing extraction tower B2. The inlet of the washing extraction tower B1 is connected to the outlet of the reaction unit A, the outlet of the washing extraction tower B1 is connected to the inlet of the washing extraction tower B2, and the outlet pipe of the washing extraction tower B2 is connected to the concentration unit C. The concentration unit C includes a falling film evaporator C1, a falling film evaporator C2, and a scraped evaporator C3; the inlet of the falling film evaporator C1 is connected to the washing extraction tower B2 and the outlet is connected to the inlet of the falling film evaporator C2; the outlet pipe of the falling film evaporator C2 is connected to the scraped evaporator C3; and the outlet pipe of the scraped evaporator C3 is connected to the product drying unit D. The drying unit D includes a belt dryer D1, a product pulverizer D2, and a spiral continuous dryer D3; the inlet pipe of the belt dryer D1 is connected to the scraper evaporator C3 and the outlet is connected to the product pulverizer D2, and the outlet of the product pulverizer D2 is connected to the spiral continuous dryer D3.
2. The low molecular weight polyphenylene ether preparation system according to claim 1, characterized in that, The reaction unit includes a reaction vessel A1 and a reaction liquid buffer vessel A2. The outlet of the reaction vessel A1 is connected to the reaction liquid buffer vessel A2, and the outlet of the reaction liquid buffer vessel A2 is connected to the washing unit B.
3. The low molecular weight polyphenylene ether preparation system according to claim 2, characterized in that, The reactor A1 is equipped with a raw material feeding metering device and an oxygen distributor; the reaction liquid buffer reactor A2 has a cooling function.
4. The low molecular weight polyphenylene ether preparation system according to claim 1, characterized in that, The reaction unit A is an intermittent operation, while the washing unit B, concentration unit C, and drying unit D are continuous operations.
5. The low molecular weight polyphenylene ether preparation system according to claim 1, characterized in that, The exhaust gas outlets of the concentration unit C and the drying unit D are connected to the falling film evaporator E2 for recovering the reaction solvent; the gas phase outlet pipe of the falling film evaporator E2 is connected to a vacuum pump.
6. The low molecular weight polyphenylene ether preparation system according to claim 1, characterized in that, The waste liquid from the washing unit B2 is connected to the high gravity distillation recovery unit E1 for recovering the washing solvent.
7. The low molecular weight polyphenylene ether preparation system according to claim 1, characterized in that, A packaging unit is provided after the drying unit D for packaging products.
8. The low molecular weight polyphenylene ether preparation system according to claim 1, characterized in that, The product crusher D2 outlet is equipped with a screen.