Blow molding ethylene resin composition and blow molded article therefrom

Abstract

A blow molding ethylene resin composition satisfies the following requirements [a], [b], [c] and [d] at the same time: [a] the melt flow rate (MFR) at a temperature of 190° C. under a load of 21.6 kg is in the range of 1.0 to 15 g/10 min; [b] the density is in the range of 955 to 970 kg/m 3 ; [c] the number of methyl branches per 1000 carbon atoms is less than 0.1 according to 13 C-NMR; [d] the tensile impact strength measured at −40° C. in accordance with JIS K 7160 is not less than 270 kJ/m 2 .

1 .- 9 . (canceled) 
     
     
         10 . A blow molding ethylene resin composition satisfying the following requirements [a], [b], [c] and [d] at the same time:
 [a] the melt flow rate (MFR) at a temperature of 190° C. under a load of 21.6 kg is in the range of 1.0 to 15 g/10 min;   [b] the density is in the range of 955 to 970 kg/m 3 ;   [c] the number of methyl branches per 1000 carbon atoms is less than 0.1 according to  13 C-NMR;   [d] the tensile impact strength measured at −40° C. in accordance with JIS K 7160 is not less than 270 kJ/m 2 .   
     
     
         11 . The blow molding ethylene resin composition according to  claim 10 , which further satisfies the following requirement [e]:
 [e] the flexural modulus measured in accordance with JIS K 7171 is in the range of 1,100 to 1,700 MPa.   
     
     
         12 . The blow molding ethylene resin composition according to  claim 10 , which further satisfies the following requirement [f]:
 [f] in a full-notch tensile fatigue test (FNFT, testing temperature: 80° C., testing speed: 0.5 Hz) in accordance with JIS K 6774, the actual stress is in the range of 5 to 12 MPa when the number of cycles to fracture is 10,000 and the actual stress is in the range of 4 to 8 MPa when the number of cycles to fracture is 100,000.   
     
     
         13 . The blow molding ethylene resin composition according to  claim 11 , which further satisfies the following requirement [f]:
 [f] in a full-notch tensile fatigue test (FNFT, testing temperature: 80° C., testing speed: 0.5 Hz) in accordance with JIS K 6774, the actual stress is in the range of 5 to 12 MPa when the number of cycles to fracture is 10,000 and the actual stress is in the range of 4 to 8 MPa when the number of cycles to fracture is 100,000.   
     
     
         14 . The blow molding ethylene resin composition according to  claim 10 , which further satisfies the following requirement [g]:
 [g] in a tensile creep test (testing temperature: 80° C.) in accordance with JIS K 7115, the creep strain at a test stress of 6 MPa after 100 hours is not more than 10%.   
     
     
         15 . The blow molding ethylene resin composition according to  claim 11 , which further satisfies the following requirement [g]:
 [g] in a tensile creep test (testing temperature: 80° C.) in accordance with JIS K 7115, the creep strain at a test stress of 6 MPa after 100 hours is not more than 10%.   
     
     
         16 . The blow molding ethylene resin composition according to  claim 12 , which further satisfies the following requirement [g];
 [g] in a tensile creep test (testing temperature: 80° C.) in accordance with JIS K 7115, the creep strain at a test stress of 6 MPa after 100 hours is not more than 10%.   
     
     
         17 . The blow molding ethylene resin composition according to  claim 13 , which further satisfies the following requirement [g]:
 [g] in a tensile creep test (testing temperature: 80° C.) in accordance with JIS K 7115, the creep strain at a test stress of 6 MPa after 100 hours is not more than 10%.   
     
     
         18 . A blow molded article that comprises a layer comprising the blow molding ethylene resin composition of any one of  claims 10  to  17 . 
     
     
         19 . A fuel tank comprising the blow molded article of  claim 18 . 
     
     
         20 . A fuel tank that is a blow molded article comprising a laminate structure having a polyethylene layer (I) comprising the blow molding ethylene resin composition of any one of  claims 10  to  17 , a barrier layer (II), a recycled layer (III) and an adhesive layer (IV). 
     
     
         21 . The fuel tank according to  claim 20 , wherein the polyethylene layer (I) and the barrier layer (II) are laminated together through the adhesive layer (IV). 
     
     
         22 . The fuel tank according to  claim 20 , wherein the barrier layer (II) comprises an ethylene/vinyl alcohol copolymer. 
     
     
         23 . The fuel tank according to  claim 21 , wherein the barrier layer (II) comprises an ethylene/vinyl alcohol copolymer.