Bimodal polyethylene resin with flame retardant property for large-caliber thick-wall low-sag pipe and preparation method of bimodal polyethylene resin

• Main Authors: WANG LU, WENG XIANGBIN, YU GUANGCAI, QU YUNCHUN, ZHONG FENG, QIAN HONGJUN, KANETOSHI
• Format: Patent
• Language: Chinese; English
• Published: 27.10.2023
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS

The invention provides a flame-retardant bimodal polyethylene resin for a large-caliber thick-wall low-sag pipe and a preparation method of the flame-retardant bimodal polyethylene resin. The resin comprises a high-molecular-weight part and a low-molecular-weight part, and the mass ratio of the low-molecular-weight part to the high-molecular-weight part is 2: 8-8: 2; the number-average molecular weight Mn is 1,500 to 10,000, the weight-average molecular weight Mw is 15,000 to 450,000, the Mw/Mn is 15 to 300, the melt flow rate MFRs is 0.1 to 1.5 g/10min, the resin density is 0.935 to 0.955 g/cm < 3 >, and the flame retardant property reaches V2 or above. The bimodal polyethylene resin provided by the invention can be prepared by a reactor formed by connecting a loop reactor and a fluidized bed reactor in series. The bimodal polyethylene resin has the advantages of favorable flame retardancy, improved mechanical properties, favorable processability, favorable strength and favorable sag resistance, and is suita