Process for preparing polyamide 6 having a low dimer content
The present invention relates to a process for preparing polyamide 6 (PA 6) by hydrolytic polymerization of epsilon-caprolactam. In a first reaction step, a first intermediate mixture is formed by ring opening epsilon-caprolactam in the presence of water, under conditions of increased pressure and t...
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Main Authors | , |
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Format | Patent |
Language | English |
Published |
01.07.2004
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Edition | 7 |
Subjects | |
Online Access | Get full text |
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Summary: | The present invention relates to a process for preparing polyamide 6 (PA 6) by hydrolytic polymerization of epsilon-caprolactam. In a first reaction step, a first intermediate mixture is formed by ring opening epsilon-caprolactam in the presence of water, under conditions of increased pressure and temperature. The first intermediate mixture is then dehydrated to form a dehydrated intermediate having a water content of less than 0.5 wt. %. The dehydrated intermediate is subsequently polymerized to. produce a polyamide 6 product having a low dimer content (e.g., of less than 0.3 wt. %). The invention also relates to an apparatus in which the process may be performed. The apparatus includes, in sequence, a pressure reactor (23) having heat exchange surfaces (36), a dehydration device (24) that is in fluid communication with the pressure reactor (23), and a main reactor (25) that is in fluid communication with the dehydration device (24). |
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Bibliography: | Application Number: US20030701315 |