초록 ▼

A class of relatively high molecular weight, high density ethylene polymers (HMW-HDPE) is disclosed capable of being formed into thin films of high strength, such polymers having a density of at least about 0.925 g/cc, a flow index (I.sub.21) no highier than about 15 g/10 min., a melt flow ratio (MF

A class of relatively high molecular weight, high density ethylene polymers (HMW-HDPE) is disclosed capable of being formed into thin films of high strength, such polymers having a density of at least about 0.925 g/cc, a flow index (I.sub.21) no highier than about 15 g/10 min., a melt flow ratio (MFR) of at least about 65, and a dynamic elasticity at 0.1 rad./sec. of no higher than about 0.7 at a corresponding complex viscosity at 0.1 rad./sec. no highier than about 14E5, i.e., about 14.times.10.sup.5 poises. The ethylene polymer is a bimodal blend of relatively high molecular weight (HMW) and low molecular weight (LMW) ethylene polymers.

대표청구항 ▼

[ We claim:] [1.]1. A blend for blown film production, wherein the blend exhibits a density of about 0.940 to 0.960 g/cc, an I.sub.21 of about 4 to 12 g/10 min., a MFR of 75 to 180, and a dynamic elasticity of about 0.45 to 0.65 at a corresponding complex viscosity of about 6E5 to 14E5 poises, where

[ We claim:] [1.]1. A blend for blown film production, wherein the blend exhibits a density of about 0.940 to 0.960 g/cc, an I.sub.21 of about 4 to 12 g/10 min., a MFR of 75 to 180, and a dynamic elasticity of about 0.45 to 0.65 at a corresponding complex viscosity of about 6E5 to 14E5 poises, wherein the blend consists essentially ofat least about 0.5 weight fraction of a first component having a density of at least about 0.910 g/cc, a flow index or high load melt index (I.sub.21) of no higher than about 0.8 g/10 min., a molecular weight distribution indicated by a flow ratio (FR) no higher than about 15, and a dynamic elasticity at 0.1 rad./sec., of no higher than about 0.75 at a corresponding, complex viscosity at 0.1 rad./sec. of no higher than about 7E6; anda second component having a lower molecular weight than said first component and having a density of at least about 0.940 g/cc and a melt index (I.sub.2) of at least about 100 g/10 minwherein each of said first component and said second component is selected from the group consisting of a homopolymer of ethylene and at least one copolymer of a preponderance of ethylene with a minor amount of a 1-olefin containinig 3 to about 10 carbon atoms as comonomer, said film exhibiting a Dart Drop Impact resistance (F50, ASTM D1709) of 250 to 600 grams.