Graft modified ethylene/.alpha.-olefin copolymer

A moldable graft modified ethylene/.alpha.-olefin copolymer composition obtained by graft copolymerizing an ethylene/.alpha.-olefin copolymer composition with a polar monomer, wherein the ethylene/.alpha.-olefin copolymer composition comprises:

• (A1) an ethylene/.alpha.-olefin copolymer in an amount of 20 to 90% by weight, which is obtained by copolymerizing ethylene with an .alpha.-olefin of 3 to 20 carbon atoms in the presence of a catalyst for olefin polymerization comprising (a) an organoaluminum oxy-compound and (b) at least one kind of a transition metal compound represented by the following formula ›b-I!:
• ML.sup.1.sub.x ›b-I!
• wherein M is a transition metal atom selected from Group IVB of the periodic table, L.sup.1 is a ligand coordinating to the transition metal atom M, at least two of L.sup.1 are groups selected from a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group and a substituted cyclopentadienyl group having at least one substituent group selected from a hydrocarbon group of 3 to 10 carbon atoms, L.sup.1 other than the (substituted) cyclopentadienyl group is a hydrocarbon group of 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom, and X is a valence of the transition metal atom M, and
• at least one kind of a transition metal compound represented by the following formula ›b-II!:
• ML.sup.2.sub.x ›b-II!
• wherein M is a transition metal atom selected from Group IVB of the periodic table, L.sup.2 is a ligand coordinating to the transition metal atom, at least two of L.sup.2 are substituted cyclopentadienyl groups having 2-5 substituent groups selected from a methyl group and an ethyl group, L.sup.2 other than the substituted cyclopentadienyl group is a hydrocarbon group of 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom, and x is a valence of the transition metal atom M and which has such properties that:
• (A-i) the density is in the range of 0.850 to 0.980 g/cm.sup.3,
• (A-ii) the intrinsic viscosity (.eta.) as measured in decalin at 135.degree. C. is in the range of 0.4 to 8 dl/g;
• and
• (A-iii) the melt tension (MT (g)) at 190.degree. C. and the melt flow rate (MFR) satisfy the relation
• MT>2.2.times.MFR.sup.-0.84,
• and
• (B1) an ethylene/.alpha.-olefin copolymer in an amount of 10 to 80% by weight, which has a density and MFR different from the ethylene/.alpha.-olefin copolymer (A1) and is obtained by copolymerizing ethylene with an .alpha.-olefin of 3 to 20 carbon atoms in the presence of a catalyst for olefin polymerization comprising (a) an organoaluminum oxy-compound and (b') a compound of Group IV transition metal of the periodic table containing a ligand having a cyclopentadienyl skeleton, and which has such properties that:
• (B-i) the density is in the range of 0.850 to 0.980 g/cm.sup.3, and
• (B-ii) the intrinsic viscosity (.eta.) as measured in decalin at 135.degree. C. is in the range of 0.4 to 8 dl/g.