IMPROVED POLYETHYLENE RESIN COMPOSITIONS HAVING LOW MI AND HIGH MELT STRENGTH

• Main Authors: OSWALD THOMAS, COSTEUX STEPHANE, CHUM PAK WING S, SWOGGER KURT
• Format: Patent
• Language: English
• Published: 28.12.2007
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; GENERAL PROCESSES OF COMPOUNDING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

Ethylene polymer compositions comprising a high molecular weight high density polyethylene resin and a low density polyethylene resin are disclosed, where the polymer composition has a comparatively high melt strength for a given melt index. The compositions comprise from 25 to 99 percent by weight of the composition of a linear or substantially linear polyethylene polymer having a density of at least about 0.90 g/cc, and an I21 of less than about 20; and from 1 to 25 percent by weight of the composition of a high pressure low density type polyethylene resin having a melt index (I2) less than about 5, a molecular weight distribution greater than about 10, a Mw_abs/Mw_gpc ratio ("Gr") of at least 2.7, and a melt strength at 190°C greater than 19.0-12.6*log10(Mi). The compositions of the present invention are particularly well suited for blown film and thermoforming applications.