The process of adding additives to polycarbonate.

Abstract

The invention proposes an additive addition device and an additive process for polycarbonate, capable of solving the technical problem of increasing the melting rate of additives while ensuring the quality of polycarbonate products. The additive addition device for polycarbonate consists of a mixing tank (1), a liquid storage tank (2), a material pump (3), and a transport pipeline (4), wherein the transport pipeline (4) is used to sequentially connect the mixing tank (1), the liquid storage tank (2), and the material pump (3); the feed hopper (6) is provided at the top of the mixing tank (1); the material pump (3) is connected to the discharge of the mixing tank (1); the circulation pipeline (7) is connected between the mixing tank (1) and the material pump (3), and the ball valve of the circulation pipeline (8) is fitted to the circulation pipeline (7); The ball valve of the transport pipeline (9) is fitted into the transport pipeline (4) between the material pump (3) and the liquid storage tank (2).The equipment has a simple structure, convenient operation, and low production costs, while also improving the efficiency of mixing additives with ESO. Furthermore, according to the method of using the equipment, the maintenance temperature of ESO is limited to increase the dissolution rate of additives, thus allowing the additives to better improve the quality and performance of polycarbonate products.

Description

A polycarbonate additive adding device and adding process Technical Field

[0001] The invention relates to the technical field of polycarbonate processing, in particular to an auxiliary agent adding device and an adding process for polycarbonate. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Polycarbonate is a high-molecular-weight polymer containing carbonate groups in its molecular chain. Based on the structure of the ester groups, it can be classified into aliphatic, aromatic, and aliphatic-aromatic types. Polycarbonate plastic is a plastic primarily composed of polycarbonate. Polycarbonate is an amorphous polymer that transforms into a transparent glass-like substance after melting and cooling, exhibiting excellent optical and mechanical properties. It has a high melting point, is resistant to low temperatures, and exhibits low water absorption. It also exhibits excellent impact resistance, electrical insulation, and aging resistance, and is resistant to inorganic and organic dilute acids. Polycarbonate plastic is used in signage, instrument housings, furniture, automotive lighting, electrical components, and instrument panels. Polycarbonate exhibits excellent optical, flame retardant, and electrical properties, as well as dimensional stability.

[0004] During the processing of polycarbonate, some antioxidants, release agents, color powders and other additives are usually added during the melt extrusion process. These additives are difficult to disperse evenly when added directly into the polycarbonate melt and are prone to agglomeration, affecting product quality.

[0005] Liquid addition systems can solve the problem of additive agglomeration. However, additives generally have high melting points, requiring the use of suitable solvents that do not affect product quality. Therefore, ensuring product quality while accelerating additive melting is a pressing technical challenge in polycarbonate production.

[0006] Summary of the Invention

[0007] In order to solve the technical problem of accelerating the melting of an additive while ensuring the quality of a polycarbonate product, the present invention provides an additive adding device and an adding process for polycarbonate.

[0008] Specifically, the technical solution of the present invention is as follows:

[0009] In a first aspect, the present invention provides a polycarbonate additive addition device, comprising a mixing and preparing tank, a liquid storage tank, a feed pump, and a delivery pipe, wherein the delivery pipe sequentially connects the mixing and preparing tank, the liquid storage tank, and the feed pump; the mixing and preparing tank is provided with a steam heating jacket on the outside, a feed hopper is provided on the top of the mixing and preparing tank, and the feed pump is connected to the discharge port of the mixing and preparing tank;

[0010] A circulation pipe is connected between the mixing tank and the pumping pump, and a circulation pipe ball valve is installed on the circulation pipe. A delivery pipe ball valve is installed on the delivery pipe between the pumping pump and the liquid storage tank.

[0011] By adopting the above technical solution, during the preparation of the polycarbonate additive solution, the ball valve on the circulation pipe is opened and the ball valve on the delivery pipe is closed at the same time, which can promote the circulation of the additive solution in the mixing and preparation tank, so that the various components in the additive solution are evenly dispersed, thereby ensuring its excellent effect; after the mixing and preparation is completed, the ball valve on the circulation pipe and the ball valve on the delivery pipe are opened at the same time, and a part of the additive solution can be returned to the mixing and preparation tank under the drive of the pump, thereby increasing the flow efficiency of the additive solution to prevent the additive solvent from precipitating, condensing, etc., and at the same time, the flow rate of the additive solution can be adjusted, so that the addition amount of the additive is optimized, thereby promoting the effective modification effect of each additive on polycarbonate.

[0012] By adopting the above technical solution, the stirring device in the mixing preparation tank can accelerate the dissolution of the additive in ESO; when the stirring device is running, the driving motor drives the rotation of the stirring shaft, and the stirring shaft then drives the rotation of the stirring paddle, thereby realizing the stirring function. It has a simple structure, easy operation, low production cost, and can effectively improve the efficiency of additive mixing.

[0013] A second aspect of the present invention provides a process for mixing and adding additives to polycarbonate, comprising the following steps:

[0014] (1) Open the nitrogen pipeline ball valve on the nitrogen pipeline to protect the mixing tank with nitrogen; open the steam pipeline ball valve, steam pipeline pneumatic valve and steam condensate ball valve on the steam pipeline to increase the temperature of the mixing tank; open the heating cable of the delivery pipeline of the pumping pump to increase the temperature of the pipeline;

[0015] (2) Open the feed hopper of the mixing tank, add ESO and the additive into the mixing tank in sequence, and mix and prepare to obtain a mixed solution of the additive and ESO;

[0016] (3) heating the mixed solution obtained in step (2) while stirring;

[0017] (4) self-circulating the auxiliary agent solution obtained in step (3);

[0018] (5) Open the outlet valve of the mixing preparation tank, send the uniform mixed liquid obtained in step (4) to the liquid storage tank through the delivery pipe, start the liquid feeding mode of the extruder barrel, and accurately control the uniform mixed liquid in the liquid storage tank to be added to the polycarbonate melt in the extruder barrel.

[0019] Preferably, in step (3), the temperature of the ESO is maintained at 45-55°C;

[0020] Preferably, in step (3), the mixing time of the additive and ESO is 2.5-3 hours;

[0021] Preferably, in step (5), the mixed liquid is sampled and analyzed before being pumped into the liquid storage tank, and the pumping operation is performed when the weight percentage of the dissolved auxiliary agent is 98%-100%.

[0022] By adopting the above technical solution, if the weight percentage of dissolved additives in the mixed liquid is less than 98%, it means that a large amount of additives has not yet dissolved. If the mixed liquid is added to the liquid storage tank at this time, the additives will be unevenly mixed in the polycarbonate melt, thereby affecting the additive's modification effect on the polycarbonate. By measuring the content before drawing the material, the quality and performance of the polycarbonate product can be better guaranteed.

[0023] The beneficial effects of one or more embodiments of the present invention are:

[0024] 1) By setting up a mixing tank, a feed pump, and a liquid storage tank, the additive is first dissolved in the release agent ESO that can be used in the polycarbonate processing process, avoiding the introduction of new additive solvents and reducing the impact on the quality of the polycarbonate product;

[0025] 2) A circulation pipe is provided. Through the cooperation of the ball valve on the circulation pipe and the ball valve on the delivery pipe, a portion of the additive solution can be returned to the mixing tank under the drive of the pump, thereby increasing the flow efficiency of the additive solution to prevent the additive solvent from precipitation, condensation, etc. At the same time, the flow rate of the additive solution can be adjusted, so as to facilitate the addition amount of the additive to reach the optimal state, thereby promoting the effective modification effect of each additive on polycarbonate.

[0026] 3) By setting the ESO maintenance temperature and the mixing time of ESO and additives, and by measuring the amount of additive dissolved in the mixed liquid before extraction, the dissolution efficiency of the additive is optimized, thereby enabling the additive to better improve the quality and performance of polycarbonate products. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] FIG1 is a schematic structural diagram of a polycarbonate additive mixing and adding system;

[0029] In the figure, 1. Mixing and preparation tank; 2. Liquid storage tank; 3. Feeding pump; 4. Delivery pipe; 5. Steam heating jacket; 6. Feed hopper; 7. Circulation pipe; 8. Ball valve on circulation pipe; 9. Ball valve on delivery pipe; 10. Stirring device; 11. Nitrogen pipeline; 12. Steam pipeline; 13. Steam pipeline ball valve; 14. Steam condensate ball valve; 15. Nitrogen pipeline ball valve; 16. Safety valve root valve; 17. Delivery pipeline heating tape; 18. Insulation cotton; 19. Steam pipeline pneumatic valve; 20. Mixing and preparation tank outlet valve; 21. Liquid storage tank inlet valve; 22. Feeding pump outlet backflow valve; 23. Feeding pump inlet backflow valve; 24. Condensate outlet pressure gauge; 25. Mixing and preparation tank temperature gauge; 26. Feeding pump outlet pressure gauge; 27. Extruder barrel; 28. Condensate collection tank. DETAILED DESCRIPTION

[0030] In conjunction with specific embodiments below, it should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs.

[0031] It should be noted that the terms used herein are for describing particular embodiments only and are not intended to limit the exemplary embodiments according to the present invention.

[0032] As mentioned in the background technology, in the process of producing polycarbonate, ensuring the quality of polycarbonate products while accelerating the melting of additives is a technical problem that urgently needs to be solved. To solve this technical problem, the present invention provides a polycarbonate additive addition device and addition process.

[0033] In one embodiment of the present invention, a device for adding additives to polycarbonate is provided, comprising a mixing and preparing tank, a liquid storage tank, a pumping pump, and a delivery pipe, wherein the delivery pipe sequentially connects the mixing and preparing tank, the liquid storage tank, and the pumping pump; a steam heating jacket is provided on the outside of the mixing and preparing tank, a feed hopper is provided on the top of the mixing and preparing tank, and the pumping pump is connected to the discharge port of the mixing and preparing tank;

[0034] A circulation pipe is connected between the mixing tank and the pumping pump, and a circulation pipe ball valve is installed on the circulation pipe. A delivery pipe ball valve is installed on the delivery pipe between the pumping pump and the liquid storage tank.

[0035] By adopting the above technical solution, during the preparation of the polycarbonate additive solution, the ball valve on the circulation pipe is opened and the ball valve on the delivery pipe is closed at the same time, which can promote the circulation of the additive solution in the mixing and preparation tank, so that the various components in the additive solution are evenly dispersed, thereby ensuring its excellent effect; after the mixing and preparation is completed, the ball valve on the circulation pipe and the ball valve on the delivery pipe are opened at the same time, and a part of the additive solution can be returned to the mixing and preparation tank under the drive of the pump, thereby increasing the flow efficiency of the additive solution to prevent the additive solvent from precipitating, condensing, etc., and at the same time, the flow rate of the additive solution can be adjusted, so that the addition amount of the additive is optimized, thereby promoting the effective modification effect of each additive on polycarbonate.

[0036] In a specific embodiment, the polycarbonate additive adding device further comprises: a nitrogen pipeline, a nitrogen pipeline ball valve, a steam pipeline, a steam pipeline ball valve, a steam pipeline pneumatic valve and a condensate collection tank;

[0037] Opening the nitrogen pipeline ball valve on the nitrogen pipeline can protect the mixing and preparing tank with nitrogen; opening the steam pipeline ball valve and the steam pipeline pneumatic valve on the steam pipeline can heat the mixing and preparing tank; the condensate collection tank is used to collect the liquid after the steam condenses.

[0038] In a specific embodiment, the polycarbonate additive adding device further comprises a conveying pipeline heating tape and thermal insulation cotton; the conveying pipeline heating tape can heat the pipeline, and the thermal insulation cotton can keep the temperature of the pipeline warm;

[0039] In a specific embodiment, the polycarbonate additive adding device further comprises an extruder barrel, the liquid feeding mode of the extruder barrel is turned on, and polycarbonate melt is placed in the extruder barrel.

[0040] In a specific embodiment, the polycarbonate additive adding device further includes a steam condensate ball valve; a safety valve root valve, a mixing tank outlet valve, a liquid storage tank inlet valve, a feed pump outlet backflow valve and a feed pump inlet backflow valve.

[0041] In a specific embodiment, the polycarbonate additive adding device further includes a condensate outlet pressure gauge, a mixing tank temperature gauge, and a feed pump outlet pressure gauge.

[0042] In one embodiment of the present invention, a process for mixing and adding additives to polycarbonate is provided. The process is simple to operate and can effectively accelerate the melting of the additives. The process is achieved by the following technical solution:

[0043] A polycarbonate additive addition process comprises the following steps:

[0044] 1. Open the nitrogen pipeline ball valve on the nitrogen pipeline to protect the ESO prefabricated tank with nitrogen; open the steam pipeline ball valve, steam pipeline pneumatic valve and steam condensate ball valve on the steam pipeline to increase the temperature of the mixing tank; open the heating cable of the delivery pipeline of the material pump to increase the temperature of the pipeline;

[0045] 2. Open the feed hopper of the mixing tank, add ESO and additives into the mixing tank one after another, and mix to obtain a mixed solution of additives and ESO;

[0046] 3. The mixed solution obtained in step 2 is heated while being stirred;

[0047] 4. The auxiliary agent solution obtained in step 3 is self-circulated;

[0048] 5. Open the outlet valve of the mixing tank, and deliver the uniform mixed liquid obtained in step 4 to the liquid storage tank through the delivery pipe. Turn on the liquid feeding mode of the extruder barrel, and precisely control the uniform mixed liquid in the liquid storage tank to add it to the polycarbonate melt in the extruder barrel.

[0049] By adopting the above technical solution, the present invention adds the additives to the hot ESO to promote the rapid dissolution of the additives; the obtained mixed liquid is then self-circulated to obtain a uniform additive solution, thereby reducing the impact of additive agglomeration on polycarbonate production; the additive solution is then temporarily stored in a liquid storage tank using a pump. The pump promotes the uniformity and stability of the additive solution and is also used as a flow regulating device for the additive solution during the production of polycarbonate; finally, the liquid storage tank is used to accurately control the proportion of additives added to the polycarbonate melt. Compared with adding solid powder directly to the melt, the liquid after the additives are fully dissolved can achieve a better dispersion effect, thereby ensuring that the modifying effect of each additive on the polycarbonate is effectively exerted. The entire use process is simple to operate and can achieve rapid dissolution of the additives, thereby helping to improve the production efficiency and product quality of polycarbonate.

[0050] In a specific embodiment, in step ③, the temperature of the ESO is maintained at 45-55°C.

[0051] By adopting the above technical solution, when the ESO temperature is higher than 100°C, the additives and ESO will decompose and volatilize, resulting in the addition amount of additives and ESO to the polycarbonate melt being lower than the actual feed amount, making it difficult to ensure the additive's modification effect on the polycarbonate. However, excessively high temperatures are not conducive to energy-saving production. The additives can be fully dissolved in the ESO at around 50°C. When the ESO temperature is lower than 45°C, the dissolution rate of the additives is significantly lower than that above 45°C. Therefore, setting the ESO temperature to 45-55°C can not only ensure the stability of the additives and ESO, but also save energy, while effectively increasing the dissolution rate of the additives, allowing the additives to better improve the quality and performance of polycarbonate products.

[0052] In one specific embodiment, in step (3), the mixing time of the additive and ESO is 2.5-3 hours. By adopting the above technical solution, under the same stirring conditions, when the mixing time is less than 2.5 hours, the dissolution rate of the additive decreases, thereby affecting the mixing of the additive and the polycarbonate melt. When the mixing time exceeds 3 hours, the content of the additive and ESO decreases, resulting in unnecessary waste. Therefore, setting the mixing time of the additive and ESO to 2.5-3 hours ensures that the additive dissolves quickly and effectively in the ESO, allowing the additive to effectively improve the quality and performance of the polycarbonate product.

[0053] In one specific embodiment, in step ⑤, the mixed liquid is sampled and analyzed before being pumped into the liquid storage tank. When the weight percentage of the dissolved additive in the mixed liquid is between 98% and 100%, the extraction operation is performed. By employing this technical solution, if the weight percentage of the dissolved additive in the mixed liquid is less than 98%, it indicates that a significant amount of the additive remains undissolved. Adding the mixed liquid to the liquid storage tank at this point will result in uneven mixing of the additive in the polycarbonate melt, thereby affecting the additive's modification effect on the polycarbonate. By measuring the content before extraction, the quality and performance of the polycarbonate product can be better guaranteed.

[0054] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0055] Example 1

[0056] A polycarbonate additive addition device comprises a mixing and preparation tank, a liquid storage tank, a feed pump, and a delivery pipe, all connected in sequence by a delivery pipe. The delivery pipe sequentially connects the mixing and preparation tank, the liquid storage tank, and the feed pump. The mixing and preparation tank is externally provided with a steam heating jacket, and a feed hopper for adding additives and ESO is provided at the top of the mixing and preparation tank. The feed pump is connected to the discharge port of the mixing and preparation tank, and the liquid storage tank is connected to the extruder barrel. A circulation pipe is connected between the mixing and preparation tank and the feed pump, and a circulation pipe ball valve is installed on the circulation pipe. The delivery pipe between the feed pump and the liquid storage tank is also equipped with a delivery pipe ball valve.

[0057] Example 2

[0058] A method for using a polycarbonate additive adding device comprises the following steps:

[0059] 1. Open the nitrogen pipeline ball valve on the nitrogen pipeline to protect the ESO prefabricated tank with nitrogen; open the steam pipeline ball valve, steam pipeline pneumatic valve and steam condensate ball valve on the steam pipeline to increase the temperature of the mixing tank; open the heating cable of the delivery pipeline of the material pump to increase the temperature of the pipeline;

[0060] 2. Open the feed hopper of the mixing tank, add ESO and additives into the mixing tank one after another, and mix to obtain a mixed solution of additives and ESO;

[0061] 3. The mixed solution obtained in step 2 was heated while stirring, and the heating temperature was maintained at 50°C; the mixing time of the additive and ESO was 2.5 hours;

[0062] 4. The auxiliary agent solution obtained in step 3 is self-circulated;

[0063] 5. Open the outlet valve of the mixing tank and deliver the uniform mixed liquid obtained in step 4 to the liquid storage tank through the delivery pipe. Turn on the liquid feeding mode of the extruder barrel and precisely control the uniform mixed liquid in the liquid storage tank to add it to the polycarbonate melt in the extruder barrel. The mixed liquid must be sampled and analyzed before being pumped into the liquid storage tank. When the weight percentage of the dissolved additive reaches 98%, the pumping operation is carried out.

[0064] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A device for adding additives to polycarbonate, characterized in that: The mixing tank comprises a mixing and preparing tank, a liquid storage tank, a material pump, and a delivery pipe, wherein the delivery pipe sequentially connects the mixing and preparing tank, the liquid storage tank, and the material pump; a steam heating jacket is provided on the outside of the mixing and preparing tank, a feed hopper is provided on the top of the mixing and preparing tank, and the material pump is connected to the discharge port of the mixing and preparing tank; A circulation pipe is connected between the mixing tank and the pumping pump, and a circulation pipe ball valve is installed on the circulation pipe. A delivery pipe ball valve is installed on the delivery pipe between the pumping pump and the liquid storage tank.

2. The device for adding additives to polycarbonate according to claim 1, characterized in that: The mixing tank is provided with a stirring device, and the outer wall of the mixing tank is provided with a steam heating jacket; Preferably, the polycarbonate additive adding device further comprises a conveying pipeline heating tape and thermal insulation cotton; Preferably, the polycarbonate additive adding device further comprises an extruder barrel.

3. The device for adding additives to polycarbonate according to claim 1, characterized in that: The polycarbonate additive adding device further comprises: a nitrogen pipeline and a steam pipeline, wherein the nitrogen pipeline is provided with a nitrogen pipeline ball valve; the steam pipeline is provided with a steam pipeline ball valve and a steam pipeline pneumatic valve; Preferably, the polycarbonate additive adding device further comprises a steam condensate ball valve; a safety valve root valve, a mixing tank outlet valve, a liquid storage tank inlet valve, a pump outlet backflow valve and a pump inlet backflow valve; Preferably, the polycarbonate additive adding device further comprises a condensate outlet pressure gauge, a mixing tank temperature gauge and a feed pump outlet pressure gauge.

4. The method for using the device for adding additives to polycarbonate according to any one of claims 1 to 3, characterized in that: 1) Slightly open the nitrogen pipeline ball valve on the nitrogen pipeline to provide nitrogen protection for the ESO prefabricated tank; open the steam pipeline ball valve, steam pipeline pneumatic valve and bottom steam condensate ball valve on the steam pipeline, open the ball valve at the root of the safety valve to increase the temperature of the mixing tank; open the heating cable of the feed pump delivery pipeline to increase the temperature of the pipeline; 2) Open the feed hopper of the mixing tank, add ESO and the additive into the mixing tank in sequence, and mix to obtain a mixed solution of the additive and ESO; 3) heating the mixed solution obtained in step 2) while stirring; 4) self-circulating the auxiliary agent solution obtained in step 3); 5) Open the outlet valve of the mixing tank, deliver the uniform mixed liquid obtained in step 4) to the liquid storage tank through the delivery pipe, start the liquid feeding mode of the extruder barrel, and accurately control the uniform mixed liquid in the liquid storage tank to be added to the polycarbonate melt in the extruder barrel.

5. The method for using the polycarbonate additive adding device according to claim 4, characterized in that: In step 3), the temperature of the ESO is maintained at 45-55°C.

6. The method for using the polycarbonate additive adding device according to claim 5, characterized in that: In step 3), the temperature of the ESO was maintained at 50°C.

7. The method for using the polycarbonate additive adding device according to claim 4, characterized in that: In step 3), the mixing time of the additive and ESO is 2.5-3 hours.

8. The method for using the polycarbonate additive adding device according to claim 7, characterized in that: In step 3), the mixing time of the additive and ESO is 2.5 h.

9. The method for using the polycarbonate auxiliary liquid system according to claim 4, characterized in that: In step 4), the self-circulation time of the additive and ESO is 0.5-1 h.

10. The method for using the polycarbonate auxiliary liquid system according to claim 4, characterized in that: In step 4), the mixed liquid is sampled and analyzed before being added to the liquid storage tank. When the weight percentage of the dissolved auxiliary agent is 98%-100%, it is added to the liquid storage tank.

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