METHOD FOR RECOVERING ε-CAPROLACTAM AND POLYAMIDE 6 OLIGOMER, AND METHOD FOR PRODUCING POLYAMIDE 6

WIPO Patent Application WO/2023/074437

A1

The present invention provides a recovery method with less energy consumption, the recovery method being capable of recovering ε-caprolactam and a polyamide 6 oligomer with high yield by depolymerization with use of a little water and solid-liquid separation only. The present invention provides a method for recovering ε-caprolactam and a polyamide 6 oligomer, the method being characterized by a process in which: a resin composition (A) that contains at least a polyamide 6 is added with at least one of water (B) that is heated to a temperature of 290°C to 350°C and an aqueous polyamide 6 oligomer solution (B1) that is heated to a temperature of 290°C to 350°C so as to be in contact with each other, thereby obtaining a reaction mixture (C) that contains at least ε-caprolactam, the polyamide 6 oligomer and water; and subsequently, the reaction mixture (C) is subjected to solid-liquid separation (I) in a temperature range that is not more than the boiling point of water at the operating pressure, thereby separating and recovering the polyamide 6 oligomer in a solid phase and ε-caprolactam in a liquid phase.

YAMASHITA KOHEI (JP)
TAKAHASHI AKIHIRO (JP)
KATO MASASHI (JP)
NISHIMURA MIHOKO (JP)
KATO KOYA (JP)

PCT/JP2022/038586

May 04, 2023

October 17, 2022

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TORAY INDUSTRIES (JP)

C08G69/46; C07D201/12; C07D201/16; C07D223/10; C08J11/16; C08J11/22

JPH11152266A	1999-06-08
CN102352034A	2012-02-15
JP2011088943A	2011-05-06
JP2002003472A	2002-01-09
JPH0841021A	1996-02-13
JPS4624035B1	1971-07-09
JP2019533041A	2019-11-14
JPH08217746A	1996-08-27
JPH10510280A	1998-10-06
JPH10510282A	1998-10-06

SAKAI INTERNATIONAL PATENT OFFICE (JP)

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