CN205007944U - A automatic material conveying equipment for preparing polyimide resin - Google Patents

Abstract

The utility model discloses an automatic material conveying equipment for preparing polyimide resin, including solvent conveying system, 2 set at least powder conveying system, clamp shell type reation kettle, temperature sensor, viscosity on -line measuring appearance and automatic control unit, solvent conveying system includes chemical industry solution delivery pump, flowmeter, powder conveying system is including the powder storage silo, powder transport ware and the automatic material conveying device that connect gradually, the automatic material conveying device is including the hopper, weighing sensor, blender and the powder pusher that connect gradually, heating device and agitating unit are installed to the powder storage silo. The utility model discloses a polyimide resin when production automatic material conveying, automatic control, technology is succinct, the precision is high, efficient.

Description

A kind of automatic feeding equipment for preparing polyimide resin

technical field

The utility model belongs to the field of organic synthesis solution polymerization equipment, in particular to an automatic feeding equipment for preparing polyimide resin.

Background technique

Polyimide materials are widely used in wires, cables, petroleum industry, aerospace and other fields due to their excellent high/low temperature resistance, radiation resistance, weather resistance, etc. and excellent electrical properties.

There are many preparation methods for polyimide materials, but no matter which method, it is necessary to use a reactor to prepare polyimide resin first, and the current conventional method for preparing polyimide resin is in a batch reactor. The specified raw materials are continuously added manually. Although this method is easy to implement, the time interval and amount of feeding are greatly affected by human factors, and the control of its production process is difficult to achieve stability, and the fluctuation between batches is large, so it brings great trouble to subsequent processing. , thereby affecting product quality. In addition, in this way, there is a large amount of dust during feeding, and the solvent escapes into the environment, which causes certain pollution to the environment and also has a certain impact on the health of workers.

The raw materials used to prepare polyimide resins are diamines and dianhydrides, which are susceptible to moisture and agglomeration, and are easy to block the discharge port after unpacking, and are not suitable for pipeline transportation, and are not suitable for existing feeding equipment; The stricter and higher the requirements for amine resin, the greater the labor cost, and the stricter environmental protection requirements, there is an urgent need to develop a high-efficiency, high-precision, safe and environmentally friendly automatic feeding control equipment.

Contents of the invention

The purpose of this utility model is to provide an automatic feeding equipment for preparing polyimide resin, which has simple process, high precision and high efficiency, overcomes the defects of unsafe and unstable manual feeding, and has broad industrial application prospects .

For the first time, the utility model uses chemical conveying pumps, powder conveyors and other equipment to quantitatively transport raw materials into the reaction kettle or storage bin, and realizes the quantitative and regular addition of raw materials during synthesis through precise push devices; at the same time, through temperature sensors, weighing Heavy sensors, online viscosity testers, etc. continuously monitor the reaction process; ultimately ensuring the stability of product quality.

For reaching above-mentioned purpose of the invention, the technical scheme that the utility model adopts is:

An automatic feeding device for preparing polyimide resin, comprising a solvent delivery system, at least 2 sets of powder delivery systems, a jacketed reactor, a temperature sensor, an online viscosity detector and an automatic control unit; the solvent delivery The system includes a chemical melt delivery pump and a flow meter; the powder delivery system includes a powder storage bin, a powder conveyor and an automatic feeding device connected in sequence; the automatic feeding device includes a hopper connected in sequence, a weighing sensor, A mixer and a powder pusher; the powder storage bin is equipped with a heating device and a stirring device.

The various devices of the utility model are connected by pipelines, and at the same time, check valves, electric valves or electromagnetic valves are set on the pipelines. Those skilled in the art can set the types and quantities of valves according to needs, so that the valves can be opened and closed through the automatic control unit. For raw material transfer.

In the utility model, the jacketed reactor is a place for preparing polyimide resin, and all raw materials are added therein, and it includes a plurality of feeding ports, detection ports, and observation ports. Solvent, powder, and powder are independently, controllably, and automatically added to the reactor through pipelines, and flow meters and powder pushers are connected to the feed port of the reactor through pipelines. In order to filter out impurities in the solution, improve the reaction purity, and ensure product properties, the utility model also includes a filter press, which is located under the reaction kettle. In order to obtain the reaction parameters and the reaction process in real time, the utility model is also equipped with a pressure sensor and a current transformer, and the monitoring data is transmitted to the control unit.

In the above technical solution, the powder storage bin contains a stainless steel tank body, a heating device, a stirring device and an atmosphere protection device; the stainless steel tank has an air outlet, a material inlet, and a material outlet, and a stirring device is installed; The stirring device can be a conventional stirrer; the heating device is a flexible heater with a temperature controller; the stainless steel tank is covered with a flexible heater to effectively avoid moisture absorption and agglomeration of the raw materials; the setting of the stirring device further improves the powder The heating uniformity of the material improves the moisture-proof effect; the atmosphere protection device is composed of a gas delivery pipe and a control valve, wherein the gas delivery pipe passes through the stainless steel tank and is connected to the control valve to receive the protective gas source. The part of the tank is equipped with an air outlet, which is used to deliver protective gas to the stainless steel tank; the use of gas protection effectively reduces the oxygen content in the tank, thereby preventing the material from being slowly oxidized or damp.

In the above technical solution, all parts of the automatic feeding device that are in contact with the material are made of 316L stainless steel, including sequentially connected hoppers, load cells, mixers and powder pushers; the hoppers are made of conical stainless steel cylinders and The flexible heater is composed of a flexible heater with temperature control, which can be consistent with the heating device of the powder storage bin, and is covered on the outside of the conical cylinder; the automatic feeding device also includes a bracket to support related equipment; The weighing sensor is fixed on the bracket and located below the outlet of the hopper; the powder raw material is stored in the powder storage bin, and enters the conical stainless steel hopper through the powder conveyor during use, and is weighed from the outlet of the hopper. The sensor enters the mixer after weighing, and then enters the jacketed reactor under the action of the powder pusher.

In the utility model, the feeding amount can be accurately controlled through the weighing sensor; the mixer is equipped with a stirring device, and the material is crushed and dispersed through the mixer before the powder enters the powder pusher, so as to avoid the bulk material from entering the powder pusher device, causing clogging or uneven feeding. The automatic control unit controls the feeding rate and reaction temperature through various valves, propellers, etc. according to the analysis of reaction parameters such as temperature, viscosity, current, etc.; at the same time, the control unit continuously compares these parameters with the set end point parameters, and when the end point of the reaction is reached , to end feeding and send out a prompt of production end.

In the above technical solution, the heating device used in the hopper and the powder storage bin is a flexible heater, which has uniform heating and convenient temperature control; the automatic control unit is composed of a monitoring unit, a program controller, and an operation panel, which can The addition of raw materials is controlled; the program controller is a conventional program controller, which is commercially available.

Generally, the raw materials for the production of polyimide resin are two kinds of powders, and two sets of powder conveying systems can be used to meet the needs. When other special components need to be added, those skilled in the art can choose more than two sets of powders according to needs. material delivery system.

During production, dimethylacetamide is quantitatively injected into the reaction kettle from the solvent storage tank through the chemical solution delivery pump and flow meter, and the sealed and preserved diamine powder is added at a certain speed into the dimethylacetamide through the powder delivery system. Stir for a certain period of time to fully dissolve the diamine in the reaction kettle of acetamide; use a filter press to filter the dissolved diamine to remove raw materials and solid impurities in the system. Then use another set of powder conveying system to quantitatively add dianhydride in batches into the reaction kettle containing the diamine solution, and control the reaction parameters to react to obtain polyimide resin.

When polyimide resin is synthesized, its quality is affected by the feeding method, feeding speed, reaction temperature and reaction time, and the uniformity of dianhydride feeding is particularly important, which is directly related to the reaction rate, which in turn affects the polyimide resin. Molecular weight and molecular weight distribution, if the addition speed is fast or uneven, the polymerization reaction will be locally severe, the molecular weight will rise rapidly, the width of the molecular weight distribution will be enlarged, and the molecular activity will be reduced, thereby affecting the subsequent reaction. The current conventional feeding method cannot effectively avoid this defect, resulting in poor stability between batches of the final polyimide resin, thereby affecting the quality of the final product; at the same time, the current manual feeding is open, and a large amount of raw materials are dissipated into the air. Cause some pollution to the environment. The automatic feeding equipment of the utility model has the advantages of simple and convenient automatic feeding operation, stable quality of the synthesized resin, complete automation of the whole synthesis process and unexpected effects.

Due to the use of the above-mentioned technical solutions, the utility model has the following advantages compared with the prior art:

1. The utility model discloses for the first time an automatic feeding device that can completely transport the raw materials used in the preparation of polyimide resin in an automated manner, avoiding secondary pollution of the material, thereby facilitating the automation of the subsequent process, and ensuring the quality of the polyimide resin Stable; making it possible to automate the synthesis of polyimide resin, greatly improving production efficiency and reducing costs.

2. In the automatic feeding equipment for preparing polyimide resin disclosed in this utility model, the method of heating and atmosphere protection is used for the first time when raw materials are used or stored to avoid moisture absorption and deterioration of materials, and ensure the purity and reactivity of raw materials .

3. The automatic feeding equipment for preparing polyimide resin disclosed by the utility model has high precision, and the weighing sensor, mixer, etc. can realize a more accurate feeding process, and at the same time avoid powder agglomeration, which is conducive to uniform and controllable reaction Therefore, the uniformity of the reaction in the reactor is greatly improved, and the quality uniformity of the product polyimide resin is guaranteed.

4. The automatic feeding equipment for preparing polyimide resin disclosed in this utility model is a closed system with reasonable composition, which meets the requirements and direction of contemporary green chemistry development; and can control the quality of polyimide resin with high precision; The process for preparing the product is simple, the production efficiency is high, the obtained product has good uniformity and high quality, and is suitable for automatic industrial production.

Description of drawings

Fig. 1 is the structural representation of the automatic feeding equipment that is used to prepare polyimide resin in embodiment one;

Fig. 2 is the structural representation of powder storage silo in embodiment one;

Fig. 3 is the structural representation of automatic feeding device among the embodiment one;

Among them, 1. Solvent delivery system; 11. Chemical solution delivery pump; 12. Flowmeter; 2. Diamine powder delivery system; 21. Powder storage bin; 211. Stainless steel tank; 212. Gas delivery pipe; 213 , heating device; 214, stirring device; 215, control valve; 216, air outlet; 22, powder conveyor; 23, automatic feeding device; 231, hopper; 232, flexible heater; 233, bracket; 234, weighing Sensor; 235, anti-roll block; 236, mixer; 237, powder pusher; 238, powder pusher outlet; 3, dianhydride powder conveying system; 4, filter press; 5, viscosity on-line Detector; 6. Pressure sensor; 7. Temperature sensor; 8. Current transformer; 9. Jacketed reactor;

Fig. 4 is the batch change diagram of the viscosity of the polyimide resin prepared by the equipment of the utility model and the prior art.

detailed description

Below in conjunction with accompanying drawing and embodiment the utility model is further described:

Embodiment one is used to prepare the automatic feeding equipment of polyimide resin

As shown in Figures 1 to 3, the automatic feeding equipment used to prepare polyimide resin in this embodiment includes a solvent delivery system 1, a diamine powder delivery system 2, and a dianhydride powder delivery system 3; the solvent delivery system 1 includes a chemical melt delivery pump 11 and a flow meter 12; the diamine powder delivery system 2 includes a powder storage bin 21, a powder conveyor 22 and an automatic feeding device 23 connected sequentially through pipelines; the automatic feeding device It includes a hopper 231, a load cell 234, a mixer 236, and a powder pusher 237 connected in sequence; the chemical solution delivery pump communicates with the solvent storage tank (the prior art, not shown in the figure) and the flowmeter 12; the flowmeter 12, The powder pusher 237 is respectively connected to the jacketed reactor 9 through pipelines, so that the material can be transported into the reactor; the dianhydride powder conveying system 3 includes powder storage bins, powder conveying systems connected in sequence through pipelines. Device, hopper, weighing sensor, mixer and powder pusher; the flow meter and powder pusher are respectively connected to the jacketed reactor through pipes, so that the material can be transported into the reactor. Check valves, solenoid valves and electric valves are installed on the material transmission pipeline as required to control the material transmission status and prevent material backflow. For the sake of concise reference numbers, the labeling of conventional valves is omitted. The composition and structure of the diamine powder conveying system and the dianhydride powder conveying system are the same. For the sake of brevity, the labeling of the dianhydride powder conveying system is omitted.

There is a filter press 4 under the jacketed reactor, which can effectively filter the solution impurities and ensure the purity of the reaction; there are also viscosity online detector 5, pressure sensor 6, temperature sensor 7, and current transformer 8, which can detect the reaction process in real time. The measured signal is transmitted to the automatic control unit. The automatic control unit can control the opening and closing of the valve, the switch of the chemical solution conveying pump, the powder conveyor, and the powder pusher, and can realize the automatic addition of materials according to the actual situation of the reaction.

The automatic control unit is composed of a monitoring unit, a program control system and an operation panel, which can control the addition of raw materials according to the reaction situation; the program control system is a conventional program controller, which is commercially available; those skilled in the art can set the automatic control unit according to the actual space position, For the sake of brevity of reference numerals, the drawings of this embodiment are not shown.

The powder storage bin 21 includes a stainless steel tank body 211 , a heating device 213 , an atmosphere protection device and a stirring device 214 . The atmosphere protection device is composed of a gas delivery pipe 212 and a control valve 215. The gas delivery pipe is provided with an air outlet 216; the gas delivery pipe passes through the stainless steel tank and is connected to the control valve to receive the protective gas source, and the use of gas protection effectively reduces the pressure of the tank. Oxygen content in the body, so as to prevent the material from being slowly oxidized or damp. The stainless steel tank 211 has a material inlet, a dust-proof exhaust port and a material outlet; the heating device 213 is a flexible heater with a temperature controller, which is wrapped around the stainless steel tank; effectively avoiding moisture absorption and agglomeration of raw materials ; The setting of the stirring device 214 further improves the uniformity of the heating of the powder and improves the moisture-proof effect, which is a conventional agitator. Each port is equipped with a solenoid valve or an electric valve, and the conditions of discharging and feeding are controlled by the control unit.

The hopper 231, bracket 233, load cell 234, mixer 236 and powder pusher 237 constitute the automatic feeding device 23; the hopper 231 is composed of a conical stainless steel cylinder and a flexible heater 232, and the flexible heater is covered on the conical cylinder. The outside of the body; the top of the conical stainless steel cylinder has a dust-proof exhaust port and a feed port, wherein the feed port is connected to the discharge port of the powder storage bin 21 through the powder conveyor 22, which can transport raw materials; the bracket 233 Relevant equipment can be placed, space is saved, uniform, and an anti-roll block 235 is provided to prevent the automatic feeding device from tilting when vibrating. The weighing sensor 234 is located below the outlet of the hopper 231 . After the raw material enters the conical hopper, it is protected from moisture and deterioration under the protection of heating; the adding speed and amount are precisely controlled by the weighing sensor and the powder pusher, and the material enters the reaction kettle through the discharge port 238 of the powder pusher 237 . The mixer and the powder pusher are controlled separately by the same reducer (one in and two out), and the reducer is controlled by an electric motor. Due to the addition of a high-precision weighing unit and a controllable pusher, the program automatically analyzes the reaction process, so that during the synthesis, the amount added is automatically adjusted according to the synthesis situation, and finally the resin synthesis is more stable and the quality is higher.

Dimethylacetamide is quantitatively injected into the reaction kettle through the solvent delivery system, and the sealed and preserved diamine powder is added into the reaction kettle with acetamide at a certain speed through the diamine powder delivery system, and stirred for a certain period of time. The diamine is fully dissolved, and the dissolved diamine is filtered by a filter press; then the dianhydride is added in batches through the dianhydride powder conveying system, and the reaction parameters are controlled to obtain a polyimide resin.

Preparation of polyimide resin

Using the above equipment, first transport 950Kg N,N-dimethylacetamide to the reaction kettle, add 113.74kg of 4,4-diaminodiphenyl ether into the solvent through the diamine powder delivery system, and stir for 40 minutes Use a filter press to filter the dissolved diamine; then use the dianhydride powder conveying system to add pyromellitic dianhydride in batches and stages to the reaction kettle containing the diamine solution. The specific feeding process is shown in Table 1.

Table 1 Dianhydride adding process

The first stage 0-60 minutes The adding rate of dianhydride is: 60±0.5kg/h second stage 60-150 minutes The adding rate of dianhydride is: 45±0.5kg/h The third stage 150-240 minutes The adding rate of dianhydride is: 15±0.5kg/h fourth stage 240-300 minutes The adding rate of dianhydride is: 4±0.2kg/h

This reaction is an exothermic reaction. With the continuous addition of dianhydride, the temperature of the reactor gradually rises, the viscosity continues to increase, and the resistance of the stirring motor becomes larger and larger. The automatic control unit continuously analyzes the collected data, and Adjust the amount of cooling water and materials added; at the same time, compare the parameters with the end point parameters. When the specified end point conditions are reached, a prompt message will be issued, and the synthesis will end.

End point control conditions: resin viscosity 50±5Pa.s, temperature 60±1℃. At the end of the synthesis, use the NDJ-4 rotational viscometer to test the resin viscosity again. If it is 50±5Pa.s, confirm the end of the synthesis.

The viscosity of the resin reflects the molecular weight of polyimide to a certain extent, so the viscosity test, which is more convenient to test, is generally used in production to characterize the molecular weight of the resin. As shown in Figure 4, count the viscosity of the polyimide resin prepared by the existing feeding method and the automatic feeding method of the present invention, it can be seen that the polyimide resin prepared by this example has higher stability between batches , is less affected by human factors, and fully automated control, which ultimately makes the prepared polyimide resin higher in quality and more convenient in operation.

Embodiment 2 is used to prepare the automatic feeding equipment of polyimide resin

The structure of the main body of the equipment in this embodiment is similar to that of Embodiment 1, including a solvent delivery system, a diamine powder delivery system, and a dianhydride powder delivery system; the hopper does not contain a heating device. Increase the power of the mixer and increase the number of times of press filtration at the same time, the operation complexity is higher than that of the equipment in Example 1, but the batch quality of the prepared polyimide product is also far better than the prior art.

Embodiment three is used for preparing the automatic feeding equipment of polyimide resin

The main structure of the equipment in this embodiment is similar to that of Embodiment 1, including a solvent delivery system, a diamine powder delivery system, and a dianhydride powder delivery system; the powder storage bin does not contain an atmosphere protection device. In practical applications, the powder If there is a little caking, it is necessary to increase the power of the mixer and increase the number of press filtrations. The operation complexity is higher than that of the equipment in Example 1, but the batch quality of the prepared polyimide product is also far better than that of the prior art.

Embodiment 4 is used to prepare the automatic feeding equipment of polyimide resin

The main structure of the equipment in this embodiment is similar to that of Embodiment 1, including a solvent delivery system, a diamine powder delivery system, and a dianhydride powder delivery system; it contains 3 sets of powder delivery systems, and in actual application, the third set of powder delivery systems The conveying system is used to add the filler modifier, which needs to increase the number of press filtration, and the batch quality of the prepared polyimide product is also far better than the existing technology; especially solves the problem of fillers in the existing filler-containing polyimide resin It is easy to gather and easily generate stress concentration points.

Embodiment five is used for preparing the automatic feeding equipment of polyimide resin

The main structure of the equipment in this embodiment is similar to that of Embodiment 1, including a solvent delivery system, a diamine powder delivery system, and a dianhydride powder delivery system; filter presses are not included, and in practical applications, it is necessary to increase the stirring device and mixing The power of the device, the operating energy consumption and the noise are higher than those of the equipment in Example 1, but the batch quality of the prepared polyimide product is also far better than that of the prior art.

Claims (10)

1. for the preparation of an automatic charging equipment for polyimide resin, it is characterized in that: the described automatic charging equipment for the preparation of polyimide resin comprises solvent delivery system, at least 2 cover powder delivery system, jacket type reactor, temperature sensor, viscosity on-line detector and automatic control units; Described solvent delivery system comprises chemical industry solution delivery pump, flowmeter; Described powder delivery system comprise connect successively powder storing storehouse, powder conveying device and automatic feeding device; Described automatic feeding device comprises the hopper, LOAD CELLS, blender and the powder pusher that connect successively; Described powder storing storehouse is provided with heater and agitating device.

2. according to claim 1 for the preparation of the automatic charging equipment of polyimide resin, it is characterized in that: described powder storing storehouse comprises stainless steel tank body, heater, agitating device and atmosphere protection device; Described atmosphere protection device is made up of air shooter and by-pass valve control; Described air shooter is provided with venthole.

3. according to claim 1 for the preparation of the automatic charging equipment of polyimide resin, it is characterized in that: described hopper comprises stainless steel cylinder, heater.

4. according to claim 2 or 3 for the preparation of the automatic charging equipment of polyimide resin, it is characterized in that: described heater is the flexible heater with temperature controller.

5. according to claim 3 for the preparation of the automatic charging equipment of polyimide resin, it is characterized in that: described stainless steel cylinder is cone-shaped stainless steel cylindrical shell.

6. according to claim 1 for the preparation of the automatic charging equipment of polyimide resin, it is characterized in that: described automatic control unit is made up of monitoring means, cyclelog, operation screen.

7. according to claim 1 for the preparation of the automatic charging equipment of polyimide resin, it is characterized in that: the described automatic charging equipment for the preparation of polyimide resin also comprises filter press.

8. according to claim 1 for the preparation of the automatic charging equipment of polyimide resin, it is characterized in that: the described automatic charging equipment for the preparation of polyimide resin also comprises pressure sensor and current transformer.

9. according to claim 1 for the preparation of the automatic charging equipment of polyimide resin, it is characterized in that: described automatic feeding device also comprises the support with anti-dumping block.

10., according to claim 1 for the preparation of the automatic charging equipment of polyimide resin, it is characterized in that: the described automatic charging equipment for the preparation of polyimide resin also comprise in magnetic valve, check (non-return) valve, motor-driven valve one or several.