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Production method of caprolactam polymer with low cyclic oligomer content

A cyclic oligomer, caprolactam technology, applied in the direction of single-component polyamide rayon, etc., can solve problems such as low production efficiency and long reaction time

Inactive Publication Date: 2013-08-07
肖文华
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage is that the heat treatment equipment requires high temperature and high pressure resistance; after polymerization, the reaction time is still long and the production efficiency is low.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0018] Melt 90 parts of caprolactam at 110°C, put in 4.7 parts of terephthalic acid, 3.3 parts of hexamethylenediamine and 2 parts of deionized water, heat up to 260°C, pressurize to 0.5MPa, and continue the reaction for 3 hours; then depressurize to 1 kg, kept for 4 hours; then, vacuumed for 30 minutes, filled with nitrogen, and discharged. Gained polyamide 6 chip test results are as follows:

[0019] Relative viscosity (96% sulfuric acid): 2.8, conversion rate of caprolactam 91.6%, oligomer content: 0.62%

example 2

[0021] Melt 90 parts of caprolactam at 110°C, add 7 parts of AH salt and 2 parts of deionized water, heat up to 240°C, pressurize to 0.5MPa, and continue the reaction for 3 hours; then reduce the pressure to 1 kg and keep for 4 hours; then , heated up to 290°C, vacuumed for 90 minutes, filled with nitrogen, and discharged. Vacuum drum drying for 5 hours at a drying temperature of 100°C. Gained polyamide 6 chip test results are as follows:

[0022] Relative viscosity (96% sulfuric acid): 3.2, caprolactam conversion: 90.6%, oligomer content: 1.05%

example 3

[0024] 90 parts of caprolactam were melted at 110°C, and 7 parts of ω-aminocaproic acid and 2 parts of deionized water, 0.2 parts of terephthalic acid, 0.1 part of benzoic acid, 0.2 parts of hexamethylenediamine and 0.2 parts of 4-amino-2 were put in, 2,6,6-tetraalkyl-piperidine, and 0.3 parts of titanium dioxide. Heat up to 260°C, pressurize to 0.5MPa, and continue to react for 3 hours; then depressurize to 1 kg, and keep for 5 hours; then, fill with nitrogen, and dry the material in a vacuum drum for 5 hours at a drying temperature of 100°C. Gained polyamide 6 chip test results are as follows:

[0025] Relative viscosity (96% sulfuric acid): 2.4, caprolactam conversion 92.6%, oligomer content: 0.55%.

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PUM

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Abstract

The invention relates to the field of polyamide production, in particular to a production method of caprolactam polymer with low cyclic oligomer content, which is characterized by comprising the following steps of: melting caprolactam at 90-120 DEG C, then adding an initiator, a molecular weight regulator, an additive and deionized water and reacting for 0.5-6h at the temperature of 180-280 DEG Cand the pressure intensity of 0-3.5MPa; putting the reacted materials into a two-segment polymerizer and reacting for 0.5-12h at the temperature of 200-300 DEG C and the pressure intensity of -0.1-0MPa; and carrying out strip casting, dicing and drying on the generated caprolactam polymer, and then packaging or carrying out melt spinning directly; or carrying out strip casting and dicing on the generated caprolactam polymer and then extracting for 0-6h by using 100-DEG C boiling water. Compared with the prior art, the caprolactam content in a polyamide polymer is less than 8 percent, and the cyclic oligomer content is less than 1 percent, and the two contents are both lower than the current technical level.

Description

[technical field] [0001] The invention relates to the field of polyamide production, in particular to a caprolactam polymerization production method of less cyclic oligomers. [Background technique] [0002] As one of the important organic chemical raw materials, caprolactam is mainly used to form polyamide chips (usually called nylon-6 chips, also known as nylon-6 chips) through polymerization, which can be further processed into nylon fibers, engineering plastics, and plastic films. [0003] At present, the global caprolactam polymerization production methods mainly include hydrolytic ring-opening polymerization and anionic polymerization, among which hydrolytic ring-opening polymerization accounts for the vast majority of caprolactam polymerization production. Hydrolytic ring-opening polymerization caprolactam reaction is incomplete, only about 90%, there are still about 10% of small molecules and cyclic oligomers in the polymerization product, so the polymer needs to be e...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G69/36C08G69/16C08K3/22C08L77/10D01F6/90
Inventor 肖文华
Owner 肖文华