Patent ID: 8485385

Claim:
A fuel tank welded by a welding material comprising a modified polyethylene resin composition (Z) comprising from 0.5 to 95 wt % of modified polyethylene resin (X) and from 5 to 99.5 wt % of unmodified polyethylene resin (Y), the modified polyethylene resin composition (Z) having a density of from 0.938 to 0.965 g/cm 3 and a melt flow rate (temperature: 190° C., load: 2.16 kg) of from 0.05 to 1.0 g/10 min, wherein the modified polyethylene resin (X) is a modified polyethylene resin having at least one monomer selected from the group consisting of an unsaturated carboxylic acid and derivatives thereof, grafted to a polyethylene resin (A) having a density of from 0.910 to 0.965 g/cm 3 and a melt flow rate (temperature: 190° C., load: 2.16 kg) of from 0.1 to 5.0 g/10 min, wherein a grafted amount of the at least one monomer selected from the group consisting of an unsaturated carboxylic acid and derivatives thereof is within a range of from 0.001 to 5.0 wt %; the unmodified polyethylene resin (Y) is a polyethylene resin having a density of from 0.930 to 0.965 g/cm 3 , a melt flow rate (temperature: 190° C., load: 2.16 kg) of from 0.01 to 5.0 g/10 min and a melt flow rate ratio (high load melt flow rate HL-MFR (temperature: 190° C., load: 21.6 kg)/melt flow rate MFR (temperature: 190° C., load: 2.16 kg)) of from 40 to 270; and the modified polyethylene resin composition (Z) has a gasoline permeation rate through a sheet of 1 mm in thickness as measured at 65° C. of at most 50 mg/cm 2 ·24 hr, and a full notch creep rupture time under 5.5 MPa as measured at 80° C. of at least 50 hours.