PA6 resin continuous polymerization process

A polymerization process and resin technology, which is applied in the continuous polymerization process of PA6 resin, can solve problems such as the inability to meet the requirements of spinning grade volatile matter, and achieve the effects of reducing investment and equipment depreciation costs, simple process, and low energy consumption

Pending Publication Date: 2021-12-31
湖南世博瑞高分子新材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the use of three-stage serial thin-film evaporators for devolatilization cannot meet the requirements of spinning grade volatiles. The monomer content of PA6 functional masterbatch obtained by this method reaches 5%. In the actual production process, the monomer content of the melt ranges from 10% It is easy to go down to 5%, but it is very difficult to go from 5% to below 0.5%

Method used

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  • PA6 resin continuous polymerization process
  • PA6 resin continuous polymerization process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] (1) First, mix caprolactam, water, triphenyl phosphite and benzoic acid in a mass ratio of 5:1:1.5:1.0 in a preparation kettle at 60°C, after heating and stirring for 30min, to obtain an auxiliary solution, and into the storage tank, heated to 90 ℃ insulation;

[0045] (2) Mix caprolactam at a mass flow rate of 20kg / min and the auxiliary agent solution obtained in step (1) at a mass flow rate of 1.7kg / min and preheat it to 140°C, then pump it into the top of the polymerization tube, at 240-250°C (polymerization tube). The upper, middle, and lower temperatures were 240°C, 245°C, and 250°C, respectively) and 0.2MPa, and the catalytic ring-opening polymerization was carried out for 6 hours to obtain a PA6 melt (relative intrinsic viscosity was 1.8, and the content of caprolactam monomer was 9.6%). ;

[0046] (3) Pump the PA6 melt obtained in step (2) from the bottom of the polymerization tube into the top of the vertical film devolatilizer at a flow rate of 1300kg / h (the ...

Embodiment 2~5

[0050] Table 1 shows the difference technical parameters between Examples 2 to 5 and Example 1. The same as in Example 1.

[0051] Table 1 Technical parameter table of Examples 1 to 5

[0052]

[0053]Note: The ratio of additive components in step (1) in the table refers to the mass ratio of caprolactam, water, catalyst and molecular weight regulator; The temperature of the temperature zone at the beginning is: 260°C, 260°C, 260°C, 270°C, 270°C; in the steps (5) of Examples 4-5 in the table, the temperatures of the temperature zone of the twin-screw extruder starting from the machine head are in order For: 270°C, 270°C, 270°C, 270°C, 280°C, 280°C, 280°C, 290°C, 290°C, 290°C.

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Abstract

The invention relates to a PA6 resin continuous polymerization process, which comprises: (1) heating, stirring and mixing caprolactam, water, a catalyst and a molecular weight regulator to obtain an auxiliary agent solution, feeding a formed mixture into a storage tank, conducting heating, and carrying out thermal insulation; (2) mixing and preheating caprolactam and an auxiliary agent solution, pumping a heated mixture into the top of a polymerization tube, and carrying out catalytic ring-opening polymerization reaction; (3) pumping the reaction system into a vertical film devolatilization device, and carrying out high-vacuum devolatilization; (4) feeding the system into a single-screw or helical ribbon extruder, and carrying out high-vacuum devolatilization; and (5) feeding the material into a multi-screw extruder for screw extrusion devolatilization, and conducting cooling, pelletizing and drying to obtain PA6 resin pellets. The process provided by the invention can replace and reduce four working procedures of recovering caprolactam through water extraction, preparing deionized water, refining recovered monomers and post-polymerizing, the relative intrinsic viscosity of the product is high, the content of monomers and low-molecular substances is low, the process is close to the level of the existing hydrolytic polymerization process, the process is simple, the production period is short, the energy consumption is low, the investment is small, and the process is suitable for industrial production.

Description

technical field [0001] The invention relates to a resin continuous polymerization process, in particular to a PA6 resin continuous polymerization process. Background technique [0002] In the past ten years, my country's polyamide 6 (PA6) resin synthesis industry has developed rapidly, with a total output of more than 5 million tons per year, becoming the world's largest PA6 resin production base. It is expected that in the next five years, the output of PA6 resin will reach 10 million tons. [0003] The PA6 resin synthesis process is the continuous hydrolysis polymerization process of caprolactam, and its production process includes pre-polymerization, post-polymerization, cooling and pelletizing, water extraction, drying, packaging, extraction water distillation and recovery of monomers, and deionized water preparation. The post-polymerization viscosity-increasing process is used to increase the molecular weight of PA6, and the unreacted caprolactam monomer in PA6 resin i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G69/16C08G69/14
CPCC08G69/16C08G69/14
Inventor 邓凯桓葛乾顺
Owner 湖南世博瑞高分子新材料有限公司
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