Polybutyleneterephthalate resin composition and method for preparing thereof

• Main Authors: JEONG KYUNG SEOK, MYEONG SEONG HYEON
• Format: Patent
• Language: English; Korean
• Published: 06.05.2022
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS

The present invention relates to a polybutylene terephthalate resin composition including 0.5-1 parts by weight of a carbodiimide-based compound based on 100 parts by weight of a high-viscosity polybutylene terephthalate resin polymerized through solid phase polymerization, and a method for preparing the same. According to the present invention, when preparing PBT by using a solid phase polymerization process, a desired level of intrinsic viscosity is ensured first, and then an optimized content of hydrolysis inhibitor is added to allow preparation of PBT having excellent hydrolysis resistance. Therefore, it is possible to ensure high intrinsic viscosity, while using solid phase polymerization including the reaction of a carboxyl group at the end of PBT. It is also possible to maintain excellent hydrolysis resistance by preventing an excessive drop of intrinsic viscosity or an excessive increase in concentration of terminal carboxyl group even under a highly accelerated stress test (HAST) condition. 본 발명은 고상중합으로 중합된 고점도 폴리부틸렌테레프탈레이트 수지 100중량부에 대하여 카보디이미드계 화합물을 0.5 내지 1중량부로 포함하는 폴리부틸렌테레프탈레이트 수지 조성물과 이의 제조방법에 관한 것으로, 본 발명에서는 고상중합 공정을 이용하여 PBT를 제조시, 원하는 고유점도를 먼저 확보한 다음 최적 함량의 가수분해억제제를 첨가함으로써 내가수분해성이 우수한 PBT 제조가 가능하고, PBT 말단의 카르복시기의 반응으로 이루어지는 고상중합을 이용하면서도 높은 고유점도를 확보할 수 있으며, 초가속 스트레스 테스트(HAST) 조건에서도 고유점도가 과도하게 떨어지거나, 말단 카르복시기 농도가 과도하게 증가하지 않는 등 우수한 내가수분해성을 유지하는 효과를 가진다.