Polypropylene Resin for Insulating Power Cables

• Main Authors: LEE YOUNGJOO, CHUN YONGSUNG, KIM BONGSEOCK, CHOI YOUNGWOOK
• Format: Patent
• Language: English; Korean
• Published: 11.06.2019
• Subjects: BASIC ELECTRIC ELEMENTS; CABLES; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; CONDUCTORS; ELECTRICITY; INSULATORS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES; THEIR PREPARATION OR CHEMICAL WORKING-UP

The present invention relates to an ethylene-propylene block copolymer resin which is suitable for an insulating layer of power cables by having excellent flexibility, heat distortion properties and brittleness temperature properties and good dielectric breakdown strength and, more specifically, to an ethylene-propylene block copolymer resin which is excellent in production stability during polymerization by having excellent flowability of a polypropylene powder although the ethylene-propylene block copolymer resin has a high rubber polymer content. According to an aspect of the present invention, the ethylene-propylene block copolymer resin is produced by polymerizing a propylene single polymer or an ethylene-propylene random copolymer and an ethylene-propylene rubber copolymer in stages within a reactor in the presence of a Ziegler-Natta catalyst obtained by using two types of internal electron donors, one of the two types of internal electron donors is a compound including an ester group and an alkoxy group, the ethylene-propylene random copolymer has a melting temperature of 150 to 160°C, a solvent extract extracted at room temperature by xylene has a content of 30 to 50 wt%, and the solvent extract has an intrinsic viscosity of 1.5 to 3.0 dL/g. 본 발명은 가요성, 가열변형 및 내한타격 특성이 우수하고 절연 파괴 강도가 양호하여, 전력 케이블의 절연층에 적합한 에틸렌-프로필렌 블록 공중합체 수지에 관한 것으로, 고무 중합체 함량이 높지만 폴리프로필렌 파우더의 흐름성이 우수하여 중합 시 생산 안정성이 우수한 에틸렌-프로필렌 블록 공중합체 수지에 관한 것이다. 더욱 상세하게는, 본 발명의 일 양태에 따른 에틸렌-프로필렌 블록 공중합체 수지는 2종류의 내부전자공여체를 사용하여 얻어지는 지글러-나타(Ziegler-Natta) 촉매의 존재 하에서 프로필렌 단독 중합체 또는 에틸렌-프로필렌 랜덤 공중합체와 에틸렌-프로필렌 고무 공중합체가 반응기 내에서 단계적으로 중합되어 제조되며, 2종류의 내부전자공여체 중 하나가 에스테르기와 알콕시기를 포함하는 화합물이고, 에틸렌-프로필렌 랜덤 공중합체의 용융온도가 150~160℃이며, 자일렌으로 상온에서 추출되는 용제 추출물의 함량이 30~50 중량%이고, 용제 추출물의 고유점도가 1.5~3.0 ㎗/g이다.