Preparation method of polyamide 6 and polyamide 6

A polyamide and amide exchange technology, applied in the polyamide field, can solve the problems of long preparation process time, unstable product quality, and low production efficiency, and achieve stable control of process parameters, small product batch differences, and high production efficiency Effect

Inactive Publication Date: 2021-09-03
CHINESE TEXTILE ACAD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, to provide a preparation method and polyamide 6 with a uniform distribution while increasing the molecular weight of polyamide 6, and to solve the problem that the preparation process of high molecular weight polyamide 6 takes a long time. , unstable product quality, low production efficiency, and high energy consumption

Method used

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  • Preparation method of polyamide 6 and polyamide 6
  • Preparation method of polyamide 6 and polyamide 6
  • Preparation method of polyamide 6 and polyamide 6

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] In this embodiment, polyamide 6 is prepared by the following method:

[0046] a. 540kg of fresh molten caprolactam, 10.8kg of desalted water, and 0.008% mol phosphoric acid (relative to the amount of the total substance of caprolactam) are continuously added into the mixed liquid tank every hour to obtain a mixture.

[0047] b. Mix the mixture continuously in the pipeline mixer, and then enter the prepolymerization reactor to polymerize to form a prepolymer. The pressure of the prepolymerization reactor is 15 barg, the temperature is 262°C, and the residence time is 3h.

[0048] c. The prepolymer in the prepolymerization reactor is continuously sent to the first amide exchanger, the temperature of the first amide exchanger is 260° C., the residence time is 0.5 h, and the pressure drops from 15 barg to 4 barg.

[0049] d. The material of the first amide exchanger is continuously sent to the first post-reactor, the temperature of the first post-reactor is 260°C, the react...

Embodiment 46

[0057] In this example, polyamide 6 was prepared by the following method:

[0058] a. 3500kg fresh molten caprolactam, 1350kg caprolactam concentrated solution (concentration is wt.69%), 0.06% mol phenyl hypophosphite (relative to the amount of the total substance of caprolactam) are continuously added in the mixed liquid tank per hour to obtain a mixture.

[0059] b. Continuously mix the mixture in a static mixer, and then enter a prepolymerization reactor to polymerize to form a prepolymer. The pressure of the prepolymerization reactor is 25 barg, the temperature is 263°C, and the residence time is 2h.

[0060] c. Send the prepolymer in the prepolymerization reactor to the first amide exchanger, the temperature of the first amide exchanger is 270° C., the residence time is 1.5 h, and the pressure drops from 25 barg to 5 barg.

[0061] d. Send the material of the first amide exchanger to the first post-reactor, the temperature of the first post-reactor is 258° C., the reactio...

Embodiment 55

[0066] In this example, the attached figure 2 The shown route prepares polyamide 6:

[0067] a. 540kg of fresh molten caprolactam, 10.8kg of desalted water, and 0.008% mol phosphoric acid (relative to the amount of the total substance of caprolactam) are continuously added into the mixed liquid tank every hour to obtain a mixture.

[0068] b. Mix the mixture in the pipeline mixer, and then enter the prepolymerization reactor to polymerize to form a prepolymer. The pressure of the prepolymerization reactor is 10 barg, the temperature is 262°C, and the residence time is 3h.

[0069] c. The prepolymer in the prepolymerization reactor is continuously sent to the first amide exchanger, the temperature of the first amide exchanger is 260° C., the residence time is 0.5 h, and the pressure drops from 10 barg to 4 barg.

[0070] d. Send the material of the first amide exchanger to the first post-reactor, the temperature of the first post-reactor is 240° C., the reaction pressure drop...

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Abstract

The invention discloses a preparation method of polyamide 6, at least caprolactam is used as a raw material to prepare polyamide 6 through a continuous process, and a catalyst is added in any link of material mixing, amide exchange reaction in a polymerization stage, extraction and drying in the preparation process; and the polymerization stage comprises a pre-polymerization reaction and at least one section of amide exchange reaction which are carried out in sequence, and melt generated by any section of amide exchange reaction can be subjected to pelletizing, extraction and drying to prepare a polyamide 6 slice finished product. The polyamide 6 prepared by the method has the characteristics of high production efficiency, high process operability, low energy consumption and the like. The prepared polyamide 6 is stable in quality, uniform in molecular weight distribution and excellent in performance.

Description

technical field [0001] The invention belongs to the technical field of polyamides, and in particular relates to a preparation method of polyamide 6 and polyamide 6. Background technique [0002] Polyamide is one of the polymers used in large-scale preparations worldwide, in addition to being mainly used in engineering plastics, films, fibers, etc., it is also used in many other end uses. Among the polyamides, polyamide 6 (polycaprolactam), with a proportion of about 57%, is the most commonly produced polymer. Polyamide 6 with a relative molecular mass of over 30,000 has higher melt strength, and its finished products have higher mechanical properties and barrier properties. It is an excellent raw material for engineering plastics, composite films, high-strength industrial yarns, and industrial filter felts. [0003] The dynamic viscosity of polyamide 6 melt increases rapidly with the increase of molecular weight. Higher operating temperature is required to improve fluidity ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G69/14C08G69/16C08G69/46
CPCC08G69/14C08G69/16C08G69/46
Inventor 李鑫姜锋于春晓黄玉民邱志成胡志宇王雪
Owner CHINESE TEXTILE ACAD
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