Method for preparing polyamide resin

• Main Authors: LEE MYUNG OCK, KIM JI HYUN, PARK JAE YUN, HWANG YONG TAEK
• Format: Patent
• Language: English; Korean
• Published: 03.06.2020
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; MAKING GRANULES OR PREFORMS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

Disclosed in the present invention is a method for preparing a straight chain aliphatic polyamide resin, which reduces annular by-products generated during polymerization and reduces color discoloration caused at a high temperature and a high pressure by using a novel method without a need for a flash process when preparing a straight chain aliphatic polyamide resin comprising cadaverine. The present invention provides a method for preparing a straight chain aliphatic polyamide resin, comprising the steps of: (a) preparing a pre-polymer by preliminarily polymerizing dicarboxylic acid and diamine in a first reactor; (b) discharging and pelletizing the preliminarily polymerized pre-polymer while maintaining a temperature of the first reactor higher than a melting point of the preliminarily pre-polymer; and (c) inputting the pelletized pre-polymer into a second reactor to polymerize the same at a solid state at a temperature of less than 200°C. 카다베린를 포함하는 직쇄형 지방족 폴리아미드 수지를 제조함에 있어 중합 시 발생하는 환형 부산물을 저감시키고, 고온 및 고압 하에서 발생하는 색상 변색을 저감시키면서도, 플래쉬 공정 채용이 필요 없는 새로운 방식의 직쇄형 지방족 폴리아미드 수지 제조방법이 개시된다. 본 발명은 (a) 제1 반응기에 디카르복실산 및 디아민을 예비중합하여 프리폴리머를 제조하는 단계; (b) 상기 제1 반응기의 온도를 상기 예비중합된 프리폴리머의 융점보다 높게 유지하면서 상기 예비중합된 프리폴리머를 토출 및 펠렛타이징하는 단계; (c) 상기 펠렛타이징된 프리폴리머를 제2 반응기에 투입하여 200℃ 미만의 온도에서 고상중합하는 단계;를 포함하는 직쇄형 지방족 폴리아미드 수지 제조방법을 제공한다.