Ethylene copolymer composition

Abstract

An ethylene copolymer composition comprising an ethylene/α-olefin copolymer [A-1] which has a density, a melt flow rate (MFR), an amount of a n-decane-soluble portion in the specific ranges and whose melt tension (MT) at 190° C. and MFR satisfy the relation MT>2.2×MFR −0.84 , and one (co)polymer selected from the group consisting of [B-1] a low-density polyethylene obtained by high-pressure radical polymerization, [B-2] a crystalline polyolefin and [B-3] an olefin type elastomer. Also disclosed is an ethylene copolymer composition comprising an ethylene/α-olefin copolymer composition and the low-density polyethylene [B-1] obtained by high-pressure radical polymerization, said ethylene/α-olefin copolymer composition comprising ethylene/α-olefin copolymers [A-2] and [A-3] both having physical properties similar to those of the above ethylene/α-olefin copolymer [A-1] and having intrinsic viscosities different from each other. Further disclosed is an ethylene copolymer composition comprising an ethylene/α-olefin copolymer [A-4] which has a density, a melt flow rate (MFR), a weight of a n-decane-soluble portion in the specific ranges and whose melt tension (MT) at 190° C. and MFR satisfy the relation MT≦2.2×MFR −0.84 , and one (co)polymer selected from the above group consisting of [B-1], [B-2] and [B-3] Still further disclosed is an ethylene copolymer composition comprising an ethylene/α-olefin copolymer composition and a low-density polyethylene [B-4] obtained by high-pressure radical polymerization, said ethylene/α-olefin copolymer composition comprising ethylene/α-olefin copolymers [A-5] and [A-61] both having physical properties similar to those of the above ethylene/α-olefin copolymer [A-4] and having intrinsic viscosities different from each other. The ethylene copolymer compositions of the invention are excellent in heat stability and moldability, and able to form films of high transparency, high mechanical strength and anti-blocking resistance.

What is claimed is:  
     
         1 . An ethylene copolymer composition comprising: 
 [A-1] an ethylene/α-olefin copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms having such properties that 
 (i) the density (d) is in the range of 0.880 to 0.960 g/cm 3 ,  
 (ii) the melt flow rate (MFR) at 190° C. under a load of 2.16 kg is in the range of 0.01 to 200 g/10 min,  
 (iii) the temperature (Tm (° C)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, 
 (iv) the melt tension (MT (g)) at 190° C. and the melt flow rate (MFR) satisfy the relation 
   MT> 2.2× MFR   −0.84 , 
 (v) the flow index (FI (l/sec)) defined by a shear rate which is given when a shear stress of molten copolymer at 190° C. reaches 2.4×10 6  dyne/cm 2  and the melt flow rate (MFR) satisfy the relation 
   FI> 75× MFR , and 
 (vi) the amount (W (% by weight)) of a decane-soluble portion at 23° C. and the density (d) satisfy the relation, 
 in the case of  MFR≦ 10 g/10 min, W< 80×exp(−100( d− 0.88))+0.1in the case of  MFR> 10 g/10 min, W< 80×( MFR− 9) 0.26 ×exp(−100( d− 0.88))+0.1; 
  and  
   [B-1] a high-pressure radical polymerization low-density polyethylene having such properties that 
 (i) the melt flow rate (MFR) is in the range of 0.1 to 50 g/10 min, and  
 (ii) the molecular weight distribution (Mw/Mn, Mw=weight-average molecular weight, Mn=number−average molecular weight) measured by GPC and the melt flow rate (MFR) satisfy the relation 
   Mw/Mn≧ 7.5×log( MFR )−1.2; a weight ratio ([A-1]:[B-1]) between said ethylene/α-olefin copolymer [A-1] and said high-pressure radical polymerization low-density polyethylene [B-1] being in the range of 99:1 to 60:40.    
   
     
     
         2 . An ethylene copolymer composition comprising: 
 [A-1] an ethylene/α-olefin copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms in an amount of 60 to 99% by weight, said copolymer having such properties that 
 (i) the density (d) is in the range of 0.880 to 0.960 g/cm 3 ,  
 (ii) the melt flow rate (MFR) at 190° C. under a load of 2.16 kg is in the range of 0.01 to 200 g/10 min,  
 (iii) the temperature (Tm (° C.)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, 
 (iv) the melt tension (MT (g)) at 190° C. and the melt flow rate (MFR) satisfy the relation 
   MT> 2.2× MFR   −0.84 , 
 (v) the flow index (FI (l/sec)) defined by a shear rate which is given when a shear stress of molten copolymer at 190° C. reaches 2.4×10 6  dyne/cm 2  and the melt flow rate (MFR) satisfy the relation 
   FI> 75× MFR , and 
 (vi) the amount (W (% by weight)) of a decane-soluble portion at 23° C. and the density (d) satisfy the relation, 
 in the case of  MFR≦ 10 g/10 min, W< 80×exp(−100( d− 0.88))+0.1in the case of  MFR> 10 g/10 min, W< 80×( MFR− 9) 0.26 ×exp(−100( d− 0.88))+0.1; 
  and  
   [B-2] at least one crystalline polyolefin in an amount of 1 to 40% by weight, said crystalline polyolefin being selected from the group consisting of: 
 (B-I) an ethylene homopolymer or a copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms, prepared by using non-metallocene type catalyst, having a melt flow rate (MFR) of 0.01 to 100 g/10 min at 190° C. under a load of 2.16 kg and a density of not less than 0.900 g/cm 3 ,  
 (B-II) a propylene homopolymer or a copolymer of propylene with at least one olefin selected from ethylene and an α-olefin of 4 to 20 carbon atoms, having a melt flow rate (MFR) of 0.1 to 100 g/10 min at 230° C. under a load of 2.16 kg and a density of not less than 0.900 g/cm 3 , and  
 (B-III) a homopolymer of an α-olefin of 4 to 20 carbon atoms or a copolymer of α-olefins of 4 to 20 carbon atoms, having a melt flow rate (MFR) of 0.1 to 100 g/10 min at 230 ° C. under a load of 2.16 kg and a density of not less than 0.900 g/cm 3 .  
   
     
     
         3 . An ethylene copolymer composition comprising: 
 [A-1] an ethylene/α-olefin copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms in an amount of 60 to 99% by weight, said copolymer having such properties that 
 (i) the density (d) is in the range of 0.880 to 0.960 g/cm 3 ,  
 (ii) the melt flow rate (MER) at 190° C. under a load of 2.16 kg is in the range of 0.01 to 200 g/10 min,  
 (iii) the temperature (Tm (° C)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, 
 (iv) the melt tension (MT (g)) at 190° C. and the melt flow rate (MFR) satisfy the relation 
   MT> 2.2× MFR   −0.84 , 
 (v) the flow index (FI (l/sec)) defined by a shear rate which is given when a shear stress of molten copolymer at 190° C. reaches 2.4×10 6  dyne/cm 2  and the melt flow rate (MFR) satisfy the relation 
   FI> 75× MFR , and 
 (vi) the amount (W (% by weight)) of a decane-soluble portion at 23° C. and the density (d) satisfy the relation, 
 in the case of  MFR≦ 10 g/10 min, W< 80×exp(−100( d− 0.88))+0.1;in the case or  MFR> 10 g/10 min, W< 80×( MFR− 9) 0.26 ×exp(−100( d− 0.88))+0.1; 
  and  
   [B-3] an olefin type elastomer in an amount of 1 to 40% by weight, said elastomer having such properties that 
 (i) the density (d) is not more than 0.900 g/cm 3 , and  
 (ii) the melt flow rate (MFR) at 190° C. under a load of 2.16 kg is in the range of 0.01 to 100 g/10 men; a density ratio ([B-3]/[A-1]) of the density of said olefin type elastomer [B-3] to the density of said ethylene/α-olefin copolymer [A-1] being less than 1.  
   
     
     
         4 . An ethylene copolymer composition comprising: 
 [Ia] an ethylene/α-olefin copolymer composition which comprises [A-2] an ethylene/α-olefin copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms in an amount of 5 to 95% by weight and [A-3] an ethylene/α-olefin copolymer of ethylene with an (α-olefin of 3 to 20 carbon atoms in an amount of 5 to 95% by weight, 
 said ethylene/α-olefin copolymer [A-2] having such properties that 
 (i) the density (d) is in the range of 0.880 to 0.940 g/cm 3 ,  
 (ii) the intrinsic viscosity [η A-2 ] as measured in decalin at 135° C. is in the range of 1.0 to 10.0 dl/g,  
 (iii) the temperature (Tm (° C.)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, 
 (iv) the melt tension (MT (g)) at 190° C. and the melt flow rate (MFR) satisfy the relation 
   MT> 2.2× MFR   −0.84 , 
 (v) the flow index (FI (l/sec)) defined by a shear rate which is given when a shear stress of molten copolymer at 190° C. reaches 2.4×10 6  dyne/cm 2  and the melt flow rate (MFR) satisfy the relation 
   FI> 75× MFR , and 
 (vi) the amount (W (% by weight)) of a decane-soluble portion at room temperature and the density (d) satisfy the relation 
   W< 80×exp(−100( d− 0.88))+0.1, 
  said ethylene/α-olefin copolymer [A-3] having such properties that  
 (i) the density (d) is in the range of 0.910 to 0.960 g/cm 3 ,  
 (ii) the intrinsic viscosity [η A-3 ] as measured in decalin at 135° C. is in the range of 0.5 to 2.0 dl/g,  
 (iii) the temperature (Tm (° C.)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, and 
 (iv) the amount (W (% by weight)) of a decane-soluble portion at room temperature and the density (d) satisfy the relation, 
 in the case of  MFR≦ 10 g/10 min, W< 80×exp(−100( d− 0.88))+0.1in the case of  MFR> 10 g/10 min, W< 80×( MFR− 9) 0.26 ×exp(−100( d− 0.88))+ 0 . 1 , 
  said ethylene/α-olefin copolymer composition [Ia] having such properties that  
 (i) the density ratio ([A-2]/[A-3]) of the density of said ethylene/α-olefin copolymer [A-2] to the density of said ethylene/α-olefin copolymer [A-3] is less than 1,  
 (ii) the intrinsic viscosity ratio ([η A-2 ]/[ A-3 ]) of the intrinsic viscosity of said ethylene/α-olefin copolymer [A-2] to the intrinsic viscosity of said ethylene/α-olefin copolymer [A-3] is not less than 1,  
 (iii) the density of said composition is in the range of 0.890 to 0.955 g/cm 3 , and  
 (iv) the melt flow rate (MFR) of said composition at 190° C. under a load of 2.16 kg is in the range of of 0.1 to 100 g/10 min;  
  and  
 
   [II-a] [B-1] a high-pressure radical polymerization low-density polyethylene having such properties that 
 (i) the melt flow rate (MFR) is in the range of 0.1 to 50 g/10 min, and  
 (ii) the molecular weight distribution (Mw/Mn, Mw=weight−average molecular weight, Mn=number-average molecular weight) measured by GPC and the melt flow rate (MFR) satisfy the relation 
   Mw/Mn≧ 7.5×log( MFR )−1.2; a weight ratio ([Ia]:[IIa]) between said ethylene/α-olefin copolymer composition [Ia] and said high-pressure radical polymerization low-density polyethylene [IIa] being in the range of 99:1 to 60:40.    
   
     
     
         5 . An ethylene copolymer composition comprising: [A-4] an ethylene/α-olefin copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms having such properties that 
 (i) the density (d) is in the range of 0.880 to 0.960 g/cm 3 ,  
 (ii) the melt flow rate (MFR) at 190° C. under a load of 2.16 kg is in the range of 0.01 to 200 g/10 min,  
 (iii) the temperature (Tm (° C.)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, 
 (iv) the melt tension (MT (g)) at 190° C. and the melt flow rate (MFR) satisfy the relation 
   MT≦ 2.2 ×MFR   −0.84 , and 
 (v) the amount (W (% by weight)) of a decane-soluble portion at 23° C. and the density (d) satisfy the relation, 
 in the case of  MFR≦ 10  g/ 10 min, W < 80×exp(−100( d− 0.88))+0.1in the case of  MFR> 10 g/10 min, W< 80×( MFR− 9) 0.26 ×exp(−100( d− 0.88))+0.1; 
  and  
 [B-4] a high-pressure radical polymerization low-density polyethylene having such properties that  
 (i) the melt flow rate (MFR) is in the range of 0.1 to 50 g/10 min, and  
 (ii) the molecular weight distribution (Mw/Mn, Mw=weight−average molecular weight, Mn=number−average molecular weight) measured by GPC and the melt flow rate (MFR) satisfy the relation 
 7.5×log( MFR )−1.2≦ Mw/Mn≦ 7.5×log( MFR )+12.5; 
 a weight ratio ([A-4]:[B-4]) between said ethylene/α-olefin copolymer [A-4] and said high-pressure radical polymerization low-density polyethylene [B-4] being in the range of 99:1 to 60:40.  
 
     
     
         6 . An ethylene copolymer composition comprising: [A-4] an ethylene/α-olefin copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms in an amount of 60 to 99% by weight, said copolymer having such properties that 
 (i) the density (d) is in the range of 0.880 to 0.960 g/cm 3 ,  
 (ii) the melt flow rate (MFR) at 190° C. under a load of 2.16 kg is in the range of 0.01 to 200 g/10 min,  
 (iii) the temperature (Tm (° C.)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, 
 (iv) the melt tension (MT (g)) at 190° C. and the melt flow rate (MFR) satisfy the relation 
   MT≦ 2.2 ×MFR   −0.84 , and 
 (v) the amount (W (% by weight)) of a decane-soluble portion at 23° C. and the density (d) satisfy the relation, 
 in the case of  MFR≦ 10 g/10 min,W<80×exp(−100( d− 0.88))+0.1in the case of  MFR> 10 g/10 min,W<80×( MFR− 9) 0.26 ×exp(−100( d− 0.88))+0.1; 
  and  
 [B-2] at least one crystalline polyolefin in an amount of 1 to 40% by weight, said crystalline polyolefin being selected from the group consisting of:  
 (B-I) an ethylene homopolymer or a copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms, prepared by using non-metallocene type catalyst, having a melt flow rate (MFR) of 0.01 to 100 g/10 min at 190° C. under a load of 2.16 kg and a density of not less than 0.900 g/cm 3 ,  
 (B-II) a propylene homopolymer or a copolymer of propylene with at least one olefin selected from ethylene and an α-olefin of 4 to 20 carbon atoms, having a melt flow rate (MFR) of 0.1 to 100 g/10 min at 230° C. under a load of 2.16 kg and a density of not less than 0.90 g/cm 3 , and  
 (B-III) a homopolymer of an α-olefin of 4 to 20 carbon atoms or a copolymer of α-olefins of 4 to 20 carbon atoms, having a melt flow rate (MFR) of 0.1 to 100 g/10 min at 230 ° C. under a load of 2.16 kg and a density of not less than 0.900 g/cm 3 .  
 
     
     
         7 . An ethylene copolymer composition comprising: 
 [A-4] an ethylene/α-olefin copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms in an amount of 60 to 99% by weight, said copolymer having such properties that 
 (i) the density (d) is in the range of 0.880 to 0.960 g/cm 3 ,  
 (ii) the melt flow rate (MFR) at 190° C. under a load of 2.16 kg is in the range of 0.01 to 200 g/10 min,  
 (iii) the temperature (Tm (° C.)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, 
 (iv) the melt tension (MT (g)) at 190° C. and the melt flow rate (MFR) satisfy the relation 
   MT≦ 2.2× MFR   − 0.84, and 
 (v) the amount (W (% by weight)) of a decane-soluble portion at 23° C. and the density (d) satisfy the relation, 
 in the case of  MFR≦ 10 g/10 min, W< 80×exp(−100( d− 0.88))+0.1in the case of  MFR> 10 g/10 min,W<80×( MFR− 9) 0.26 ×exp(−100( d− 0.88))+0.1; 
  and  
   [B-3] an olefin type elastomer in an amount of 1 to 40% by weight, said elastomer having such properties that 
 (i) the density (d) is not more than 0.900 g/cm 3 , and  
 (ii) the melt flow rate (MFR) at 190° C. under a load of 2.16 kg is in the range of 0.01 to 100 g/10 min; a density ratio ([B-3]/[A-4]) of the density of said olefin type elastomer [B-3] to the density of said ethylene/α-olefin copolymer [A-4] being less than 1.  
   
     
     
         8 . An ethylene copolymer composition comprising: 
 [Ib] an ethylene/α-olefin copolymer composition which comprises [A-5] an ethylene/α-olefin copolymer of ethylene with an (α-olefin of 3 to 20 carbon atoms in an amount of 5 to 95% by weight and [A-6] an ethylene/α-olefin copolymer of ethylene with an α-olefin of 3 to 20 carbon atoms in an amount of 5 to 95% by weight,     said ethylene/α-olefin copolymer [A-5] having such properties that 
 (i) the density (d) is in the range of 0.880 to 0.940 g/cm 3 ,  
 (ii) the intrinsic viscosity [η A-5 ] as measured in decalin at 135° C. is in the range of 1.0 to 10.0 dl/g,  
 (iii) the temperature (Tm (° C.)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, 
 (iv) the melt tension (MT (g)) at 190° C. and the melt flow rate (MFR) satisfy the relation 
   MT< 2.2×MFR −0.84 , and 
 (v) the amount (W (% by weight)) of a decane-soluble portion at room temperature and the density (d) satisfy the relation 
   W< 80×exp(−100( d− 0.88))+0.1, 
  said ethylene/α-olefin copolymer [A-6] having such properties that 
 (i) the density (d) is in the range of 0.910 to 0.960 g/cm 3 ,  
 (ii) the intrinsic viscosity [η A-6 ] as measured in decalin at 135° C. is in the range of 0.5 to 2.0 dl/g,  
 (iii) the temperature (Tm (° C.)) at which the endothermic curve of said copolymer measured by a differential scanning calorimeter (DSC) shows the maximum peak and the density (d) satisfy the relation 
   Tm< 400× d− 250, and 
 (iv) the amount (W (% by weight)) of a decane-soluble portion at room temperature and the density (d) satisfy the relation, 
 in the case of  MFR≦ 10 g/10 min, W< 80×exp(−100( d− 0.88))+0.1in the case of  MFR> 10 g/10 min, W< 80×( MFR− 9) 0.26 ×exp(−100( d− 0.88))+0.1, 
  said ethylene/α-olefin copolymer composition [Ib] having such properties that 
 (i) the density ratio ([A-5]/[A-6]) of the density of said ethylene/α-olefin copolymer [A-5 ] to the density of said ethylene/α-olefin copolymer [A-6] is less than 1,  
 (ii) the intrinsic viscosity ratio ([η A-5 ]/[η A-6 ]) of the intrinsic viscosity of said ethylene/α-olefin copolymer [A-5] to the intrinsic viscosity of said ethylene/α-olefin copolymer [A-6] is not less than 1,  
 (iii) the density of said composition is in the range of 0.890 to 0.955 g/cm 3 , and  
 (iv) the melt flow rate (MFR) of said composition at 190° C. under a load of 2.16 kg is in the range of 0.1 to 50 g/10 min;  
  and  
 
 
   [IIb] [B-4] a high-pressure radical polymerization low-density polyethylene having such properties that 
 (i) the melt flow rate (MFR) is in the range of 0.1 to 50 g/10 min, and  
 (ii) the molecular weight distribution (Mw/Mn, Mw=weight−average molecular weight, Mn=number−average molecular weight) measured by GPC and the melt flow rate (MFR) satisfy the relation 
 7.5×log( MFR )−1.2≦ Mw/Mn≦ 7.5×log( MFR )+12.5; 
  a weight ratio ([Ib]:[IIb]) between said ethylene/α-olefin copolymer composition [Ib] and said high-pressure radical polymerization low-density polyethylene [IIb] being in the range of 99:1 to 60:40.