Polyethylene, thermoplastic resin composition containing same, and process for preparing polyethylene

A process for preparing a polyethylene by homopolymerizing ethylene in the presence of a transition metal compound (a), a transition metal compound (b) and a compound (c) simultaneously, said transition metal compound (a) satisfying the equation:

• 0.ltoreq..DELTA.H.multidot.Tm.ltoreq.27000-21600[M].sup.0.56
• wherein [M] is a monomer charge ratio of 1-octene/(ethylene+1-octene), (.DELTA.H) is the crystallization enthalpy and (Tm) is the melting point each of an ethylene/1-octene copolymer, when ethylene and 1-octene are copolymerized in the presence of the transition metal compound (a) in a medium which, based on 400 ml of toluene, contains 0.5 mmol. of triisobutylaluminum, 10 mmol. of methylaluminoxane, 2 .mu.mol. or 0.2 .mu.mol. of the transition metal compound (a) at 70.degree. C. or 80.degree. C. for 10 minutes, and being characterized by having the following formula:
• CpM.sup.1 R.sup.1.sub.a R.sup.2.sub.b R.sup.3.sub.c (I)
• (Cp--A.sub.e --Cp)M.sup.1 R.sup.1.sub.a R.sup.2.sub.b (III) ##STR23## wherein M.sup.1 represents titanium, zirconium, hafnium, vanadium, niobium or chromium, M.sup.3 represents titanium, zirconium or hafnium;
• and Cp represents a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a tetrahydroindenyl group, a substituted tetrahydroindenyl group, a fluorenyl group or a substituted fluorenyl group;
• a part of the carbon atoms in the cyclopentadienyl group may be substituted by a hetero-atom;
• R.sup.1, R.sup.2 and R.sup.3 each independently represents a .sigma.-bond ligand or a chelate ligand, and the .sigma.-bond ligand is selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group, an alkylaryl group or an arylalkyl group each having 6 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, an allyl group, a substituted allyl group, and a substituent containing a silicon atom;
• the chelate ligand is selected from the group consisting of an acetylacetonato group and a substituted acetylacetonato group;
• A represents a cross-linkage by a covalent bond;
• a, b and c each is independently 0 or an integer of 1 to 4, wherein a+b+c=3 in formula (I) and a+b=2 in formula (III), and e is 0 or an integer of 1 to 6;
• two or more of R.sup.1, R.sup.2 and R.sup.3 may bond to each other to form a ring;
• in formula (II) and (III), the two Cps may be the same or different from each other;
• X.sup.2 represents hydrogen, halogen, C.sub.1-20 -alkyl, aryl, C.sub.6 -C.sub.20 -alkylaryl, C.sub.6 -C.sub.20 -arylalkyl or C.sub.1-20 -alkoxy;
• Z is SiR.sup.7.sub.2, CR.sup.7.sub.2, SiR.sup.7 SiR.sup.7.sub.2, CR.sup.7.sub.2 CR.sup.7.sub.2, CR.sup.7.sub.2 CR.sup.7.sub.2 CR.sup.7.sub.2, CR.sup.7 .dbd.CR.sup.7, CR.sup.7.sub.2 SiR.sup.7.sub.2 or GeR.sup.7.sub.2, wherein R.sup.7 is hydrogen, alkyl having 20 or less non-hydrogen atoms, aryl, silyl, halogenated silyl, halogenated aryl or a combination thereof;
• and Y.sup.2 is --N(R.sup.8)--, --O--, --S-- or --P(R.sup.8)--, wherein R.sup.8 is C.sub.1-10 -alkyl, C.sub.6-10 -aryl or a condensed ring with one or more R.sup.7 s such that it has at most 30 non-hydrogen atoms, w=1 or 2;
• E.sup.1 and E.sup.2 are each C.sub.1-20 -hydrocarbon and each form a bridging group between Y.sup.4 and M.sup.1, E.sup.3 and E.sup.4 are each a .sigma.-bond ligand, a chelate ligand or a Lewis base which are the same or different from each other;
• v.sup.1 and x.sup.1 are each 0 or are 1 or 2 with v.sup.1 +x.sup.1 =an integer of the valence of M.sup.1 -2, and Y.sup.4 is a C.sub.1-20 -hydrocarbon group;
• said transition metal compound (b) being capable of forming a terminal vinyl group when ethylene is homopolymerized in the presence of the transition metal compound (b) in a medium which, based on 400 ml. of toluene, contains 0.5 mmol. triisobutylaluminum, 10 mmol. of methylaluminoxane, and 0.05 mnuol or 0.01 mmol of the transition metal compound (b) at 70.degree. C. or 80.degree. C. for 30 minutes, and being:
• (i) a compound having a --OR group wherein R is an alkyl group, an aryl group, an alkylaryl group, an arylalkyl group, a cycloalkyl group, a halogenated alkyl group or a halogenated aryl group each having 1 to 20 carbon atoms,
• (ii) Cp.sub.2 M.sup.1 R.sup.1.sub.a R.sup.2.sub.b . . . (II)
• (iii) (Cp--A.sub.e --Cp)M.sup.1 R.sup.1.sub.a R.sup.2.sub.b . . . (III)
• wherein Cp, A, M.sup.1, R.sup.1, R.sup.2, a, b and e are as defined above;
• and said compound (c) being capable of forming an ionic complex with the transition metal compound (a) or (b) or their derivative.

A process for preparing a polyethylene, which comprises:

• homopolymerizing ethylene in the presence of a transition metal compound (b) and a compound (c) simultaneously, thereby obtaining a polymerization system;
• adding a transition metal compound (a) to said polymerization system;
• and
• continuing the homopolymerization of ethylene;
• said transition metal compound (a) satisfying the equation:
• 0.ltoreq..DELTA.H.multidot.Tm.ltoreq.27000-21600[M].sup.0.56
• wherein [M] is a monomer charge ratio of 1-octene/(ethylene+1-octene), (.DELTA.H) is the crystallization enthalpy and (Tm) is the melting point each of an ethylene/1-octene copolymer, when ethylene and 1-octene are copolymerized in the presence of the transition metal compound (a) in a medium which, based on 400 ml of toluene, contains 0.5 mmol. of triisobutylaluminum, 10 mmol. of methylaluminoxane, 2 .mu.mol. or 0.2 .mu.mol. of the transition metal compound (a) at 70.degree. C. or 80.degree. C. for 10 minutes, and being characterized by having the following formula:
• CpM.sup.1 R.sup.1.sub.a R.sup.2.sub.b R.sup.3.sub.c (I)
• (Cp--A.sub.e --Cp)M.sup.1 R.sup.1.sub.a R.sup.2.sub.b (III) ##STR24## wherein M.sup.1 represents titanium, zirconium, hafnium, vanadium, niobium or chromium, M.sup.3 represents titanium, zirconium or hafnium;
• and Cp represents a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a tetrahydroindenyl group, a substituted tetrahydroindenyl group, a fluorenyl group or a substituted fluorenyl group;
• a part of the carbon atoms in the cyclopentadienyl group may be substituted by a hetero-atom;
• R.sup.1, R.sup.2 and R.sup.3 each independently represents a .sigma.-bond ligand or a chelate ligand, and the .sigma.-bond ligand is selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group, an alkylaryl group or an arylalkyl group each having 6 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, an allyl group, a substituted allyl group, and a substituent containing a silicon atom;
• the chelate ligand is selected from the group consisting of an acetylacetonato group and a substituted acetylacetonato group;
• A represents a cross-linkage by a covalent bond;
• a, b and c each is independently 0 or an integer of 1 to 4, wherein a+b+c=3 in formula (I) and a+b=2 in formula (III), and e is 0 or an integer of 1 to 6;
• two or more of R.sup.1, R.sup.2 and R.sup.3 may bond to each other to form a ring;
• in formula (II) and (III), the two Cps may be the same or different from each other;
• X.sup.2 represents hydrogen, halogen, C.sub.1-20 -alkyl, aryl, C.sub.6 -C.sub.20 -alkylaryl, C.sub.6 -C.sub.20 -arylalkyl or C.sub.1-20 -alkoxy;
• Z is SiR.sup.7.sub.2, CR.sup.7.sub.2, SiR.sup.7 SiR.sup.7.sub.2, CR.sup.7.sub.2 CR.sup.7.sub.2, CR.sup.7.sub.2 CR.sup.7.sub.2 Cr.sup.7.sub.2, CR.sup.7 .dbd.CR.sup.7, CR.sup.7.sub.2 SiR.sup.7.sub.2 or GeR.sup.7.sub.2, wherein R.sup.7 is hydrogen, alkyl having 20 or less non-hydrogen atoms, aryl, silyl, halogenated silyl, halogenated aryl or a combination thereof;
• and Y.sup.2 is --N(R.sup.8)--, --O--, --S-- or --P(R.sup.8)--, wherein R.sup.8 is C.sub.1-10 -alkyl, C.sub.6-10 -aryl or a condensed ring with one or more R.sup.7 s such that it has at most 30 non-hydrogen atoms, w=1 or 2;
• E.sup.1 and E.sup.2 are each C.sub.1-20 -hydrocarbon and each form a bridging group between Y.sup.4 and M.sup.1, E.sup.3 and E.sup.4 are each a .sigma.-bond ligand, a chelate ligand or a Lewis base which are the same or different from each other;
• v.sup.1 and x.sup.1 are each 0 or are 1 or 2 with v.sup.1 +x.sup.1 =an integer of the valence of M.sup.1 -2, and Y.sup.4 is a C.sub.1-20 -hydrocarbon group;
• said transition metal compound (b) being capable of forming a terminal vinyl group when ethylene is homopolymerized in the presence of the transition metal compound (b) in a medium which, based on 400 ml. of toluene, contains 0.5 mmol. triisobutylaluminum, 10 mmol. of methylaluminoxane, and 0.05 mmol or 0.01 mmol of the transition metal compound (b) at 70.degree. C. or 80.degree. C. for 30 minutes, and being:
• (i) a compound having a --OR group wherein R is an alkyl group, an aryl group, an alkylaryl group, an arylalkyl group, a cycloalkyl group, a halogenated alkyl group or a halogenated aryl group each having 1 to 20 carbon atoms,
• (ii) Cp.sub.2 M.sup.1 R.sup.1.sub.a R.sup.2.sub.b . . . (II)
• (iii) (Cp--A.sub.e --Cp)M.sup.1 R.sup.1.sub.a R.sup.2.sub.b . . . (III)
• wherein Cp, A, M.sup.1, R.sup.1, R.sup.2, a, b and e are as defined above;
• and said compound (c) being capable of forming an ionic complex with the transition metal compound (a) or (b) or their derivative.

A process for preparing a polyethylene by homopolymerizing ethylene in the presence of a catalyst comprising a transition metal compound (a), a transition metal compound (b) and a compound (c), said transition metal compound (a) satisfying the equation:

• 0.ltoreq..DELTA.H.multidot.Tm.ltoreq.27000-21600[M].sup.0.56
• wherein [M] is a monomer charge ratio of 1-octene/(ethylene+1-octene), (.DELTA.H) is the crystallization enthalpy and (Tm) is the melting point each of an ethylene/1-octene copolymer, when ethylene and 1-octene are copolymerized in the presence of the transition metal compound (a) in a medium which, based on 400 ml of toluene, contains 0.5 mmol. of triisobutylaluminum, 10 mmol. of methylaluminoxane, 2 .mu.mol. or 0.2 .mu.mol. of the transition metal compound (a) at 70.degree. C. or 80.degree. C. for 10 minutes, and being characterized by having the following formula:
• (Cp--A.sub.e --Cp)M.sup.1 R.sup.1.sub.a R.sup.2.sub.b (III)
• or ##STR25## wherein Cp in both formulas is a cyclic unsaturated hydrocarbon group or a chain unsaturated hydrocarbon group;
• A is a bridging group, M.sup.1 is titanium, zirconium, hafnium, vanadium, niobium or chromium, R.sup.1 and R.sup.2 are each independently a .sigma.-bond ligand or a chelating ligand, a and b each independently are zero or an integer of 1 to 4 and e is zero or an integer of 1 to 6;
• M.sup.3 is titanium, zirconium or hafnium, X.sup.2 is hydrogen, halogen, C.sub.1-20 alkyl, aryl, alkylaryl or C.sub.6 -C.sub.20 -arylalkyl or C.sub.1-20 -alkoxy, Z is SiR.sup.7.sub.2, CR.sup.7.sub.2, SiR.sup.7.sub.2 SiR.sup.7.sub.2, CR.sup.7.sub.2 CR.sup.7.sub.2, CR.sup.7.sub.2 CR.sup.7.sub.2 CR.sup.7.sub.2, CR.sup.7 .dbd.CR.sup.7, CR.sup.7.sub.2 SiR.sup.7.sub.2 or GeR.sup.7.sub.2, and Y.sup.2 is --N(R.sup.8)--, --O--, --S-- or --P(R.sup.8)--, wherein R.sup.7 is no more than 20 non-hydrogen atoms, aryl, silyl, halogenated alkyl, halogenated aryl or a combination thereof and R.sup.8 is C.sub.1-10 -alkyl or a C.sub.6-10 -aryl group, R.sup.8 is a condensed ring of one or more groups R.sup.7 and containing 30 or less non-hydrogen atoms and w is one or two;
• said transition metal compound (b) being capable of forming a terminal vinyl group when ethylene is homopolymerized in the presence of the transition metal compound (b) in a medium which, based on 400 ml. of toluene, contains 0.5 mmol. triisobutylaluminum, 10 mmol. of methylaluminoxane, and 0.05 mmol or 0.01 mmol of the transition metal compound (b) at 70.degree. C. or 80.degree. C. for 30 minutes, and being:
• (i) a compound having a --OR group wherein R is an alkyl group, an aryl group, an alkylaryl group, an arylalkyl group, a cycloalkyl group, a halogenated alkyl group or a halogenated aryl group each having 1 to 20 carbon atoms,
• (ii) Cp.sub.2 M.sup.1 R.sup.1.sub.a R.sup.2.sub.b . . . (II)
• (iii) (Cp--A.sub.e --Cp)M.sup.1 R.sup.1.sub.a R.sup.2.sub.b . . . (III)
• wherein Cp, A, M.sup.1, R.sup.1, R.sup.2, a, b and e are as defined above;
• and said compound (c) being capable of forming an ionic complex with the transition metal compound (a) or (b) or their derivative.

A polyethylene derived from an ethylene monomer in which (1) a quaternary carbon atom is not present in a polymeric main chain;

• (2) the activation energy (Ea) of the melt flow is in the range of 8 to 20 kcal/mol;
• (3) a Huggins coefficient (k) and an intrinsic viscosity (.eta.) which are decided by the relation between a polymer concentration and a reduced viscosity measured at a temperature of 135.degree. C. in a decalin solvent meet the relationship of the equation
• k.gtoreq.0.2+0.0743.times.(.eta.);
• (4) in the measurement of a loss elastic modulus, a .beta.-relaxation peak is present in the range of 0 to -100.degree. C.;
• and (5) the density (D) is within the range of 0.86 to 0.95 g/cm.sup.3, and a crystallization enthalpy (.DELTA.H) and a melting point (Tm) measured by differential scanning calorimetry (DSC) satisfies the equation
• 0.ltoreq..DELTA.H.ltoreq.250
• and the equation
• 0.02.times..DELTA.H+116<Tm<0.02.times..DELTA.H+126.

A polyethylene which is derived from an ethylene monomer and in which (1) the polymer exhibits no absorption at 8.15 ppm in its .sup.13 C-NMR spectrum;

• (2) the activation energy (Ea) of the melt flow is in the range of 8-20 kcal/mol.;
• (3) a Huggins coefficient (k) and an intrinsic viscosity (.eta.) which are decided by the relation between a polymer concentration and a reduced viscosity measured at a temperature of 135 .degree. C. in a decalin solvent meet the relationship of the equation:
• k.gtoreq.0.2+0.0743.times.(.eta.);
• and (4) in the measurement of a loss elastic modulus, a .beta.-relaxation peak is present in the range of 0 to -100.degree. C.