PROCESS FOR DEGASSING AND BUFFERING POLYOLEFIN PARTICLES OBTAINED BY OLEFIN POLYMERIZATION

• Main Authors: PENZO GIUSEPPE, MEI GABRIELE, MEI GIULIA, BAITA PIETRO, DE LUCIA ANTONIO
• Format: Patent
• Language: English; Korean
• Published: 03.08.2015
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

폴리올레핀 중합체를 제조하는 방법에 있어서, a) 중합반응기 내에서 중합촉매계의 존재 하에 1종 이상의 올레핀을 중합함으로써 미립자상 폴리올레핀 중합체를 형성하는 단계, b) 상기 형성한 폴리올레핀 입자를 상기 중합반응기로부터 배출하는 단계, c) 적어도 탈기용기 내에서 상기 폴리올레핀 입자를 질소 스트림과 접촉하는 최종 단계로 이루어진 방법에 의해 상기 폴리올레핀 입자를 탈기하는 단계, d) 상기 폴리올레핀 입자가 완충 장치를 통과하지 않고도, 해당 폴리올레핀 입자가 상기 질소 스트림과 접촉하는 상기 용기로부터, 해당 폴리올레핀 입자가 용해 및 혼합 후 펠렛화(pelletized)하는 용융혼합장치에 이송되는 단계를 포함하고, 상기 탈기용기는 일부만이 폴리올레핀 입자로 채워지며, 해당 용기의 빈 공간은, 단계 d)에서 상기 탈기용기로부터 상기 용융혼합장치로의 폴리올레핀 입자 이송이 중지되고, 단계 b)에 따른 상기 중합반응기로부터의 폴리올레핀 입자의 배출이 일정한 속도를 유지하며 연속적으로 실시될 경우, 적어도 3시간 동안 폴리올레핀 입자를 추가적으로 도입하기에 충분한 용적인, 폴리올레핀 중합체 제조방법을 제공한다. Process for preparing a polyolefin polymer comprising the steps of a) forming a particulate polyolefin polymer by polymerizing one or more olefins in the presence of a polymerization catalyst system in a polymerization reactor; b) discharging the formed polyolefin particles from the polymerization reactor; c) degassing the polyolefin particles by a process comprising at least a final step of contacting the polyolefin particles with a nitrogen stream in a degassing vessel; and d) transferring the polyolefin particles from the vessel, in which the contacting of the polyolefin particles with the nitrogen stream is carried out, to a melt mixing device, in which the polyolefin particles are melted, mixed and thereafter pelletized, without passing the particles through a buffering device, wherein the degassing vessel is only partly filled with polyolefin particles and the empty volume within the degassing vessel is sufficient to take up additional polyolefin particles for at least 3 hours if the transfer of polyolefin particles of step d) from the degassing vessel to the melt mixing device is discontinued and the discharge of polyolefin particles from the polymerization reactor according to step b) is continued with unchanged rate.