BIAXIALLY-STRETCHED FILM AND ETHYLENE POLYMER COMPOSITION

摘要

Provided is a biaxially-stretched film wherein the biaxial stretching is possible in a broader temperature range and which is excellent in thickness accuracy, and an ethylene polymer composition serving as a raw material of the film. The biaxially-stretched film of the present invention is obtained from an ethylene polymer composition (E) including a specific ethylene polymer component (A) containing 20 to 100 wt % of an ethylene polymer (a) being a copolymer of ethylene and a C4-10 α-olefin and having specific melt flow rate and density, and an ethylene polymer component (B) being another copolymer of ethylene and a C4-10 α-olefin, wherein a weight fraction [WA] of the ethylene polymer component (A) is 0.50 or more and 0.92 or less, and a weight fraction [WB] of the ethylene polymer component (B) is 0.08 or more and 0.50 or less provided that WA and WB total 1.0.

主权项

1. A biaxially-stretched film obtained from an ethylene polymer composition (E) comprising an ethylene polymer component (A) fulfilling requirements described below and an ethylene polymer component (B) fulfilling requirements described below,
wherein a weight fraction [WA] of the ethylene polymer component (A) is 0.50 or more and 0.92 or less, and a weight fraction [WB] of the ethylene polymer component (B) is 0.08 or more and 0.50 or less provided that WA and WB total 1.0, wherein the ethylene polymer component (A) comprises an ethylene polymer (a) described below at 20% by weight or more and 100% by weight or less and fulfills requirements (A-1) to (A-3) described below: (A-1) Melt flow rate (MFRA) at 190° C. under a load of 2.16 kg is not less than 0.01 g/10 min and not more than 10 g/10 min; (A-2) Density (DA) is 890 kg/m3 or more and 940 kg/m3 or less; and (A-3) Ratio [η]/Mw0.776 of intrinsic viscosity measured in decalin at 135° C. [[η](dl/g)] to weight average molecular weight measured by GPC-viscometry (GPC-VISCO) to the power 0.776 (Mw0.776) is not less than 1.90×10−4 and not more than 2.80×10−4, and wherein the ethylene polymer component (B) is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms and fulfills requirements (B-1) to (B-5) described below: (B-1) Melt flow rate (MFRB) at 190° C. under a load of 2.16 kg is not less than 0.01 g/10 min and not more than 30 g/10 min; (B-2) Density (DB) is 900 kg/m3 or more and 939 kg/m3 or less; (B-3) Sum of the number of methyl branches [Me(/1000C)] and the number of ethyl branches [Et(/1000C)] per 1000 carbon atoms in 13C-NMR analysis [(Me+Et)(/1000C)] is not more than 1.80; (B-4) Ratio η0/Mw6.8 of zero shear viscosity at 200° C. [η0(P)] to weight average molecular weight measured by GPC-viscometry (GPC-VISCO) to the power 6.8 (Mw6.8) is not less than 0.03×10−30 and not more than 7.5×10−30; and (B-5) Ratio [η]/Mw0.776 of intrinsic viscosity measured in decalin at 135° C. [[η](dl/g)] to weight average molecular weight measured by GPC-viscometry (GPC-VISCO) to the power 0.776 (Mw0.776) is not less than 0.90×10−4 and not more than 1.65×10−4, wherein the ethylene polymer (a) is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms and fulfills requirements (a-1) to (a-3) described below: (a-1) Melt flow rate (MFRa) at 190° C. under a load of 2.16 kg is not less than 0.01 g/10 min and not more than 5.0 g/10 min; (a-2) Density (Da) is 890 kg/m3 or more and 928 kg/m3 or less; and (a-3) (DB−Da)1 kg/m3.