Preactivated catalyst for olefin (CO)polymer, catalyst for olefin (CO)polymerization, olefin (CO)polymer composition, and process for producing the same

An olefin (co)polymer composition comprising, as major components, (a) 0.01 to 5 parts by weight of an olefin (co)polymer having an intrinsic viscosity [.eta..sub.a ] as measured in 135.degree. C. tetralin of 15 to 100 dl/g and (b) 100 parts by weight of an olefin (co)polymer obtained by using a metallocene catalyst and having an intrinsic viscosity [.eta..sub.b ] as measured in 135.degree. C. tetralin of 0.2 to 10 dl/g. When polyethylene having a high degree of polymerization is produced before a so-called metallocene catalyst is used to polymerize, e.g., propylene in the presence of the polyethylene as a component of a catalyst composition, a polypropylene composition having a high melt tension and a high crystallization temperature is produced.

TECHNICAL FIELD 
The present invention relates to a preactivated catalyst for olefin 
(co)polymerization that can produce an olefin (co)polymer having a high 
melt tension, a high crystallization temperature and excellent heat 
stability, and a catalyst for olefin (co)polymerization. The present 
invention also relates to an olefin (co)polymer composition having a high 
melt tension, a high crystallization temperature and excellent heat 
stability, and a method for producing the same. 
BACKGROUND ART 
Olefin (co)polymers such as polypropylene and polyethylene are widely used 
in a variety of molding fields because of their excellent mechanical 
properties, chemical resistance and cost-effectiveness. Conventionally, 
the olefin (co)polymers generally have been produced by (co)polymerizing 
olefin by using a so-called Ziegler-Natta catalyst, which is obtained by 
combining titanium trichloride or titanium tetrachloride, or a transition 
metal catalyst component comprising titanium trichloride or titanium 
tetrachloride supported by a carrier such as magnesium chloride, and an 
organic aluminum compound. 
In recent years, on the other hand, a catalyst that is obtained by 
combining metallocene and aluminoxane, which is different from catalysts 
in the prior art, is used to (co)polymerize olefins to obtain olefin 
(co)polymers. The olefin (co)polymer obtained by using the 
metallocene-based catalyst has a narrow molecular weight distribution, and 
in the case of copolymers, comonomers are copolymerized uniformly. 
Therefore, it is known that more homogeneous olefin (co)polymers can be 
obtained than in the prior art. However, compared with olefin (co)polymers 
obtained by using a conventional catalyst type, the olefin (co)polymers 
obtained by using the metallocene-based catalyst have a lower melt 
tension, so that they are not suitable for some uses. 
In order to enhance the melt tension and the crystallization temperature of 
polypropylene, the following methods have been proposed: a method of 
reacting polypropylene with an organic peroxide and a crosslinking 
assistant in a molten state (Japanese Laid-Open Patent Publication 
(Tokkai-Sho) Nos. 59-93711, 61-152754); and a method for producing 
gel-free polypropylene with free-end long chain branching by reacting 
semi-crystalline polypropylene with a peroxide having a low decomposition 
temperature in the absence of oxygen (Japanese Laid-Open Patent 
Publication (Ibkkai-Hei) No.2-298536). 
Other methods for enhancing melting viscoelasticity such as melt tension 
have been proposed, such as a method of using a composition comprising 
polyethylenes or polypropylenes having different intrinsic viscosities or 
molecular weights, or producing such compositions by multistage 
polymerization. 
Examples of such a method include a method in which 2 to 30 parts by weight 
of ultra high molecular weight polypropylene are added to 100 parts by 
weight of ordinary polypropylene and extrusion is performed in a 
temperature range from a melting point to 210.degree. C. (Japanese Patent 
Publication (kko-Sho) No. 61-28694), a method using multistage 
polymerization to obtain an extrusion sheet formed of two components of 
polypropylene having different molecular weights and a limiting viscosity 
ratio of at least 2 (Japanese Patent Publication (Ibkko-Hei) No. 1-12770), 
a method of producing a polyethylene composition formed of three types of 
polyethylene having different viscosity average molecular weights 
comprising 1 to 10 wt % of high viscosity average molecular weight 
polyethylene by melting and kneading or multistage polymerization 
(Japanese Patent Publication (Ibkko-Sho) No. 62-61057), a method for 
polymerizing polyethylene in which ultra high molecular weight 
polyethylene having an intrinsic viscosity of 20 dl/g or more is 
polymerized in an amount of 0.05 or more and less than 1 wt % by 
multistage polymerization with highly active titanium vanadium solid 
catalyst component (Japanese Patent Publication (Iokko-Hei) No. 5-79683), 
and a method for polymerizing polyethylene in which 0.1 to 5 wt % of ultra 
high molecular weight polyethylene having an intrinsic viscosity of 15 
dl/g or more is polymerized by multistage polymerization in a specially 
arranged polymerization reactor by using a highly active titanium catalyst 
component preliminarily polymerized with 1-butene or 4-methyl-1-pentene 
(Japanese Patent Publication (Ibkko-Hei) No. 7-8890). 
Furthermore, Japanese Laid-Open Patent Publication (Ibkkai-Hei) No. 
5-222122 has disclosed a method for producing polypropylene having a high 
melt tension by polymerizing propylene by using a preliminarily 
polymerized catalyst obtained by preliminarily polymerizing ethylene and a 
polyene compound with a supported titanium-containing solid catalyst 
component and an organic aluminum compound catalyst component. Japanese 
Laid-Open Patent Publication (Tokkai-Hei) No. 4-55410 has disclosed a 
method for producing linear low density polyethylene (LLDPE) having a high 
melt tension by using a preliminarily polymerized catalyst containing 
polyethylene having a limiting viscosity of 20 dl/g or more obtained by 
preliminarily polymerizing ethylene alone with the same catalyst 
components as above. 
Furthermore, the following methods have been proposed in order to enhance a 
melt tension in the case where a metallocene catalyst type is used: a 
method of using a catalyst comprising a silica carrier containing at least 
1.0 wt % of water, a metallocene, methylaluminoxane and triisobutyl 
aluminum (Japanese Laid-Open Patent Publication (Tbkkai-Hei) No. 
5-140224); a method of using two types of metallocene as catalyst 
components (Japanese Laid-Open Patent Publication (Tbkkai-Hei) Nos. 
5-255436, 5-255437 and 6-206939); and a method of using montmorillonite as 
a metallocene catalyst type (Japanese Laid-Open Patent Publication 
(Ibkkai-Hei) Nos. 7-188317 and 7-188336). 
In the various proposed compositions and the production methods thereof in 
connection with the conventional catalyst types, the melt tension of the 
polyolefin is enhanced to some extent under measurement conditions at 
190.degree. C. However, other problems still remain unsolved with respect 
to the improvement of the melt tension under use conditions at 200.degree. 
C. or more, a residual odor caused by the crosslinking assistant, the 
crystallization temperature, the heat stability of properties other than 
the melt tension, or the like. 
Furthermore, although the proposed methods in connection with the 
metallocene catalyst type provide an improvement of the melt tension of 
polyolefin under measurement conditions at 190.degree. C., it is still 
desired to improve the melt tension under use conditions at 200.degree. C. 
or more. 
DISCLOSURE OF INVENTION 
As evident from the above discussion, it is an object of the present 
invention to provide a preactivated catalyst for olefin (co)polymerization 
and a catalyst for olefin (co)polymerization that can produce an olefin 
(co)polymer having a high melt tension, a high crystallization temperature 
and excellent heat stability when (co)polymerizing olefins with a 
metallocene type catalyst. It is another object to provide an olefin 
(co)polymer composition having a high melt tension, a high crystallization 
temperature and excellent heat stability, and a method for producing the 
same. 
As a result of ardent research to achieve the objects, the inventors 
discovered that an olefin (co)polymer composition having a high melt 
tension at a high temperature and a high crystallization temperature can 
be obtained by (co)polymerizing olefins with a preactivated catalyst 
obtained by preactivation in which olefins are (co)polymerized with a 
metallocene-based catalyst for olefin (co)polymerization so as to produce 
a small amount of olefin (co)polymer having a specific intrinsic viscosity 
prior to the main (co)polymerization. 
In order to achieve the above-mentioned objects, a preactivated catalyst 
for olefin (co)polymerization of the present invention is a preactivated 
catalyst (1) obtained by (co)polymerizing olefins with the following 
compounds (A) and (B) so that an olefin (co)polymer (a) having an 
intrinsic viscosity [.eta..sub.a ] measured in tetralin at 135.degree. C. 
of 15 to 100 dl/g is generated in an amount of 1 g to 500 kg per mmol of 
transition metal in a compound (A): 
compound (A): a transition metal compound having at least one .pi. electron 
conjugated ligand; and 
compound (B): at least one compound selected from the group consisting of 
(B-1) aluminoxane, (B-2) an ionic compound that reacts with the transition 
metal compound (A) so as to form an ionic complex, and (B-3) a Lewis acid. 
The preactivated catalyst for olefin (co)polymerization may further 
comprise a compound (C): an organic aluminum compound, in addition to the 
compounds (A) and (B). 
The preactivated catalyst for olefin (co)polymerization of the present 
invention is a preactivated catalyst (2) according to the preactivated 
catalyst (1) obtained by (co)polymerizing olefins so that an olefin 
(co)polymer (aa) having an intrinsic viscosity [.eta..sub.aa ] lower than 
the intrinsic viscosity [.eta..sub.a ] of the olefin (co)polymer (a) is 
generated in an amount of 1 g to 50 kg per mol of transition metal in a 
compound (A), before, or before and after, the generation of the olefin 
(co)polymer (a). 
In the preactivated catalyst for olefin (co)polymerization, the olefin 
(co)polymer (aa) is preferably a propylene homopolymer or a 
propylene-olefin copolymer comprising at least 50 wt % of propylene 
polymerization units. 
In the preactivated catalyst for olefin (co)polymerization, the olefin 
(co)polymer (a) is preferably an ethylene homopolymer or an 
ethylene-olefin copolymer comprising at least 50 wt % of ethylene 
polymerization units. 
In the preactivated catalyst for olefin (co)polymerization, most 
preferably, the olefin (co)polymer (aa) is a propylene homopolymer or a 
propylene-olefin copolymer comprising at least 50 wt % of propylene 
polymerization units, the olefin (co)polymer (a) is an ethylene 
homopolymer or an ethylene-olefin copolymer comprising at least 50 wt % of 
ethylene polymerization units, and the preactivated catalyst is a 
preactivated catalyst for propylene (co)polymerization. 
Next, a catalyst for olefin (co)polymerization of the present invention 
comprises [1] a preactivated catalyst obtained by combining the following 
compounds (A) and (B) or the following compounds (A), (B) and (C) and 
(co)polymerizing olefins with this mixture so that an olefin (co)polymer 
(a) having an intrinsic viscosity [.eta..sub.a ] measured in tetralin at 
135.degree. C. of 15 to 100 dl/g is generated in an amount of 1 g to 500 
kg per mmol of transition metal in a compound (A); and [2] at least one 
compound selected from the group consisting of the following compounds (B) 
and (C): 
compound (A): a transition metal compound having at least one .pi. electron 
conjugated ligand; 
compound (B): at least one compound selected from the group consisting of 
(B-1) aluminoxane, (B-2) an ionic compound that reacts with the transition 
metal compound (A) so as to form an ionic complex, and (B-3) a Lewis acid; 
and 
compound (C): an organic aluminum compound. 
The above-described catalyst is preferably obtained by (co)polymerizing 
olefins so that an olefin (co)polymer (aa) having an intrinsic viscosity 
[.eta..sub.aa ] lower than the intrinsic viscosity [.eta..sub.a ] of the 
olefin (co)polymer (a) is generated in an amount of 1 g to 50 kg per mmol 
of transition metal in a compound (A), before, or before and after, the 
generation of the olefin (co)polymer (a). 
In the above-described catalyst, the olefin (co)polymer (aa) is preferably 
a propylene homopolymer or a propylene-olefin copolymer comprising at 
least 50 wt % of propylene polymerization units. 
In the above-described catalyst, the olefin (co)polymer (a) is preferably 
an ethylene homopolymer or an ethylene-olefin copolymer comprising at 
least 50 wt % of ethylene polymerization units. 
In the above-described catalyst, most preferably, the olefin (co)polymer 
(aa) is a propylene homopolymer or a propylene-olefin copolymer comprising 
at least 50 wt % of propylene polymerization units, the olefin (co)polymer 
(a) is an ethylene homopolymer or an ethylene-olefin copolymer comprising 
at least 60 wt % of ethylene polymerization units, and the catalyst is a 
catalyst for propylene (co)polymerization. 
Next, an olefin (co)polymer composition of the present invention comprises 
as its main components (a) 0.01 to 5 parts by weight of an olefin 
(co)polymer having an intrinsic viscosity [.eta..sub.a ] measured in 
tetralin at 135.degree. C. of 15 to 100 dl/g; and (b) 100 parts by weight 
of an olefin (co)polymer having an intrinsic viscosity [.eta..sub.b ] 
measured in tetralin at 135.degree. C. of 0.2 to 10 dl/g, which is 
obtained by (co)polymerizing olefins with a polymerization catalyst 
comprising the following compounds (A) and (B): 
compound (A): a transition metal compound having at least one .pi. electron 
conjugated ligand; and 
compound (B): at least one compound selected from the group consisting of 
(B-1) aluminoxane, (B-2) an ionic compound that reacts with the transition 
metal compound (A) so as to form an ionic complex, and (B-3) a Lewis acid. 
In the (co)polymer composition of the present invention, the polymerization 
catalyst further comprises an organic aluminum compound as a compound (C), 
in addition to the compounds (A) and (B). 
The (co)polymer composition of the present invention preferably has a melt 
tension (MS) at 230.degree. C. and a melt flow index (MFR) measured under 
a load of 21.18N at 230.degree. C. that satisfy the following inequality: 
EQU log (MS)&gt;-1.28.times.log (MFR)+0.44. 
In the (co)polymer composition of the present invention, the olefin 
(co)polymer (a) is preferably an ethylene homopolymer or an 
ethylene-olefin copolymer comprising at least 50 wt % of ethylene 
polymerization units. 
In the (co)polymer composition of the present invention, the olefin 
(co)polymer (b) is preferably a propylene homopolymer or a 
propylene-olefin copolymer comprising at least 50 wt % of propylene 
polymerization units. 
In a first method for producing an olefin (co)polymer composition of the 
present invention, the main (co)polymerization of olefins is performed 
with a preactivated catalyst for olefin (co)polymerization obtained by 
combining the following compounds (A) and (B) or (A), (B) and (C), and 
(co)polymerizing olefins with this mixture so that an olefin (co)polymer 
(a) having an intrinsic viscosity [.eta..sub.a ] measured in tetralin at 
135.degree. C. of 15 to 100 dl/g is generated in an amount of 1 g to 500 
kg per mmol of transition metal in a compound (A): 
compound (A): a transition metal compound having at least one .pi. electron 
conjugated ligand; and 
compound (B): at least one compound selected from the group consisting of 
(B-1) aluminoxane, (B-2) an ionic compound that reacts with the transition 
metal compound (A) so as to form an ionic complex, and (B-3) a Lewis acid, 
and 
compound (C): an organic aluminum compound. 
Next, in a second method for producing an olefin (co)polymer composition of 
the present invention, the main (co)polymerization of olefins is performed 
with a catalyst for olefin (co)polymerization comprising: 
[1] a preactivated catalyst obtained by combining the following compounds 
(A) and (B) or (A), (B) and (C) and (co)polymerizing olefins with this 
mixture so that an olefin (co)polymer (a) having an intrinsic viscosity 
[.eta..sub.a ] measured in tetralin at 135.degree. C. of 15 to 100 dl/g is 
generated in an amount of 1 g to 500 kg per mmol of transition metal in a 
compound (A); and 
[2] at least one compound selected from the group consisting of the 
following compounds (B) and (C): 
compound (A): a transition metal compound having at least one .pi. electron 
conjugated ligand; 
compound (B): at least one compound selected from the group consisting of 
(B-1) aluminoxane, (B-2) an ionic compound that reacts with the transition 
metal compound (A) so as to form an ionic complex, and (B-3) a Lewis acid; 
and 
compound (C): an organic aluminum compound. 
Next, a third method for producing an olefin (co)polymer composition of the 
present invention comprises the steps of preparing a polymerization 
catalyst comprising the following compounds (A) and (B), (co)polymerizing 
olefins with the polymerization catalyst so that an olefin (co)polymer (a) 
having an intrinsic viscosity [.eta..sub.a ] measured in tetralin at 
135.degree. C. of 15 to 100 dl/g is generated in an amount of 1 g to 500 
kg per mmol of transition metal in a compound (A), thus preparing a 
preactivated catalyst, and (co)polymerizing olefins with the preactivated 
catalyst so that an olefin (co)polymer (b) having an intrinsic viscosity 
[.eta..sub.b ] measured in tetralin at 135.degree. C. of 0.2 to 10 dl/g is 
generated, thereby obtaining a polymer comprising as the main components: 
(a) 0.01 to 5 parts by weight of the olefin (co)polymer having an intrinsic 
viscosity [.eta..sub.a ] measured in tetralin at 135.degree. C. of 15 to 
100 dl/g; and 
(b) 100 parts by weight of the olefin (co)polymer having an intrinsic 
viscosity [.eta..sub.b ] measured in tetralin at 135.degree. C. of 0.2 to 
10 dl/g: 
compound (A): a transition metal compound having at least one .pi. electron 
conjugated ligand; and 
compound (B): at least one compound selected from the group consisting of 
(B-1) aluminoxane, (B-2) an ionic compound that reacts with the transition 
metal compound (A) so as to form an ionic complex, and (B-3) a Lewis acid. 
In the third method for producing an olefin (co)polymer composition of the 
present invention, the polymerization catalyst may further comprise an 
organic aluminum compound as a compound (C), in addition to the compounds 
(A) and (B). 
In the third method for producing an olefin (co)polymer composition of the 
present invention, olefins may be (co)polymerized with the preactivated 
catalyst additionally comprising at least one compound selected from the 
group consisting of the following compounds (B) and (C): 
compound (B): at least one compound selected from the group consisting of 
(B-1) aluminoxane, (B-2) an ionic compound that reacts with the transition 
metal compound (A) so as to form an ionic complex, and (B-3) a Lewis acid; 
and 
compound (C): an organic aluminum compound. 
In the first to third methods for producing an olefin (co)polymer 
composition of the present invention, the obtained olefin (co)polymer 
composition preferably has a melt tension (MS) at 230.degree. C. and a 
melt flow index (MFR) measured under a load of 21.18N at 230.degree. C. 
that satisfy the following inequality: 
EQU log (MS)&gt;-1.28.times.log (MFR)+0.44. 
In the first to third methods for producing an olefin (co)polymer 
composition of the present invention, the olefin (co)polymer (a) is 
preferably an ethylene homopolymer or an ethylene-olefin copolymer 
comprising at least 50 wt % of ethylene polymerization units. 
In the first to third methods for producing an olefin (co)polymer 
composition of the present invention, the olefin (co)polymer (b) generated 
in the main (co)polymerization is preferably a propylene homopolymer or a 
propylene-olefin copolymer comprising at least 50 wt % of propylene 
polymerization units. 
In the first to third methods for producing an olefin (co)polymer 
composition of the present invention, an additional preactivation 
treatment may be performed wherein olefins are (co)polymerized so that an 
olefin (co)polymer (aa) having an intrinsic viscosity [.eta..sub.aa ] 
lower than the intrinsic viscosity [.eta..sub.a ] of the olefin 
(co)polymer (a) generated in the preactivation treatment is generated in 
an amount of 1 g to 50 kg per mmol of transition metal in a compound (A), 
before the preactivation treatment (before the generation of the olefin 
(co)polymer (a)), or before and after that. 
In the first to third methods for producing an olefin (co)polymer 
composition of the present invention, the olefin (co)polymer (aa) is 
preferably a propylene homopolymer or a propylene-olefin copolymer 
comprising at least 50 wt % of propylene polymerization units.

BEST MODE FOR CARRYING OUT THE INVENTION 
The term "preactivation treatment" in the specification of the present 
invention refers to a treatment in which a small amount (generally 5 wt % 
or less, particularly 1 wt % or less of the amount for the main 
(co)polymerization) of olefins are polymerized with a catalyst for olefin 
(co)polymerization, prior to the main polymerization of olefins. The 
catalyst for olefin (co)polymerization is obtained by combining a 
transition metal compound catalyst component for olefin (co)polymerization 
and an activator for making the olefin polymerization performance explicit 
by activating the transition metal compound catalyst. By this treatment, 
in the case of a homogeneous catalyst, a mixture of a small amount of 
olefin (co)polymer and the homogeneous catalyst (or a mixed slurry in the 
case where the treatment is performed in the presence of a solvent) is 
obtained. In the case where a transition metal compound catalyst component 
is supported by a carrier, the surface of the supported transition metal 
compound catalyst component (solid) is coated with olefin (co)polymers. A 
catalyst that has been subjected to a preactivation treatment is referred 
to as a "preactivated catalyst". 
In the present invention, the following compounds (A) and (B), or (A), (B) 
and (C) are combined. 
Compound (A): a transition metal compound having at least one .pi. electron 
conjugated ligand; 
Compound (B): at least one compound selected from (B-1) aluminoxane, (B-2) 
an ionic compound that reacts with the transition metal compound (A) so as 
to form an ionic complex, and (B-3) a Lewis acid; and 
Compound (C): an organic aluminum compound. 
The transition metal compound having at least one .pi. electron conjugated 
ligand of the compound (A) used in the present invention is generally 
referred to as a "metallocene", and more specifically, refers to a 
transition metal compound expressed by the following formula 1: 
EQU MLp (formula 1) 
(where M is a transition metal selected from the group consisting of Zr, 
Ti, Hf, V, Nb, Ta and Cr, p is a valence of the transition metal) 
L is a ligand coordinated with the transition metal, and at least one L is 
a .pi. electron conjugated ligand. Specific examples of the .pi. electron 
conjugated ligand include a ligand having a 77-cyclopentadienyl structure, 
a 77-benzene structure, a 77-cycloheptatrienyl structure, or a 
77-cyclooctatetraene structure, and a most preferable example is a ligand 
having a 77-cyclopentadienyl structure. 
Examples of the ligand having a 77-cyclopentadienyl structure include a 
cyclopentadienyl group, an indenyl group, an indenyl hydride group, a 
fluorenyl group or the like. These groups may be substituted with a 
hydrocarbon group such as an alkyl group, an aryl group and an aralkyl 
group, a silicon-substituted hydrocarbon group such as a trialkylsilyl 
group, a halogen atom, an alkoxy group, an aryloxy group, a chain alkylene 
group, a cyclic alkylene group or the like. 
Furthermore, in the case where the transition metal compound expressed by 
general formula [1] comprises two or more .pi. electron conjugated 
ligands, two .pi. electron conjugated ligands can be bridged each other 
through an alkylene group, a substituted alkylene group, a cycloalkylene 
group, a substituted cycloalkylene group, a substituted alkylidene group, 
a phenylene group, a silylene group, a substituted dimethylsilylene group, 
a germyl group or the like. 
Examples of L other than the .pi. electron conjugated ligand include a 
hydrocarbon group such as an alkyl group, a cycloalkyl group, an aryl 
group, an aralkyl group, a silicon-substituted hydrocarbon group, an 
alkoxy group, an aryloxy group, a substituted sulfonato group. Moreover, a 
bivalent group such as an amidesilylene group and an amidealkylene group 
may be coupled to a .pi. electron conjugated ligand. 
Hereinafter, specific examples of the metallocene compound (A) used in the 
present invention, will be described, but it is not limited thereto. 
Examples of metallocene having one .pi. electron conjugated ligand include 
(t-butylamide) (tetramethylcyclopentadienyl)-1,2-ethylene zirconium 
dimethyl, (t-butylamide) (tetramethylcyclopentadienyl)-1,2-ethylene 
titanium dimethyl, (methylamide) 
(tetramethylcyclopentadienyl)-1,2-ethylene zirconium dibenzil, 
(methylamide) (tetramethylcyclopentadienyl)-1,2-ethylene titanium 
dimethyl, (ethylamide) (tetramethylcyclopentadienyl) methylene titanium 
dimethyl, (t-butylamide) dibenzil (tetramethylcyclopentadienyl) silylene 
zirconium dibenzil, (benzilamide) dimethyl (tetramethylcyclopentadienyl) 
silylene titanium diphenyl, (phenyl phosphido) dimethyl 
(tetramethylcyclopentadienyl) silylene zirconium dibenzil or the like. 
Examples of metallocene having two .pi. electron conjugated ligands are as 
follows. Examples of metallocene having two .pi. electron conjugated 
ligands that are not bridged each other, in the case where the transition 
metal is zirconium, include bis(cyclopentadienyl) zirconium dichloride, 
bis(cyclopentadienyl) zirconium dimethyl, bis(cyclopentadienyl) zirconium 
methylchloride, (cyclopentadienyl) (methylcyclopentadienyl) zirconium 
dichloride, (cyclopentadienyl) (methylcyclopentadienyl) zirconium 
dimethyl, (cyclopentadienyl) (ethylcyclopentadienyl) zirconium dichloride, 
(cyclopentadienyl) (ethylcyclopentadienyl) zirconium dimethyl, 
(cyclopentadienyl) (dimethylcyclopentadienyl) zirconium dichloride, 
(cyclopentadienyl) (dimethylcyclopentadienyl) zirconium dimethyl, 
bis(methylcyclopentadienyl) zirconium dichloride, 
bis(methylcyclopentadienyl) zirconium dimethyl, bis(ethylcyclopentadienyl) 
zirconium dichloride, bis(ethylcyclopentadienyl) zirconium dimethyl, 
bis(propylcyclopentadienyl) zirconium dichloride, 
bis(propylcyclopentadienyl) zirconium dimethyl, bis(butylcyclopentadienyl) 
zirconium dichloride, bis(butylcyclopentadienyl) zirconium dimethyl, 
bis(dimethylcyclopentadienyl) zirconium dichloride, 
bis(dimethylcyclopentadienyl) zirconium dimethyl, 
bis(diethylcyclopentadienyl) zirconium dichloride, 
bis(diethylcyclopentadienyl) zirconium dimethyl, 
bis(methylethylcyclopentadienyl) zirconium dichloride, 
bis(methylethylcyclopentadienyl) zirconium dimethyl, 
bis(trimethylcyclopentadienyl) zirconium dichloride, 
bis(trimethylcyclopentadienyl) zirconium dimethyl, 
bis(triethylcyclopentadienyl) zirconium dichloride, 
bis(triethylcyclopentadienyl) zirconium dimethyl or the like. In addition, 
compounds comprising titanium, hafnium, vanadium, niobium, tantalum or 
chromium substituted for zirconium in these zirconium compounds can be 
used. 
In the illustrative examples as described above, a compound with a 
cyclopentadienyl ring substituted at two positions includes 1,2-and 
1,3-substituted compounds, and a compound with a cyclopentadienyl ring 
substituted at three positions includes 1,2,3-and 1,2,4-substituted 
compounds. Furthermore, an alkyl group such as propyl, butyl or the like 
includes isomers such as n-(normal-), i-(iso-), sec-(secondary-), 
tert-(tertiary-), or the like. 
Examples of metallocene having two .pi. electron conjugated ligands that 
are bridged each other include dimethylsilylene 
(3-t-butylcyclopendadienyl) (fluorenyl) zirconium dichloride, 
dimethylsilylene (3-t-butylcyclopendadienyl) (fluorenyl) hafnium 
dichloride, rac-ethylene bis(indenyl) zirconium dimethyl, rac-ethylene 
bis(indenyl) zirconium dichloride, rac-dimethylsilylene bis(indenyl) 
zirconium dimethyl, rac-dimethylsilylene bis(indenyl) zirconium 
dichloride, rac-ethylene bis(tetrahydroindenyl) zirconium dimethyl, 
rac-ethylene bis(tetrahydroindenyl) zirconium dichloride, 
rac-dimethylsilylene -bis(tetrahydroindenyl) zirconium dimethyl, 
rac-dimethylsilylene bis(tetrahydroindenyl) zirconium dichloride, 
rac-dimethylsilylene bis(2-methyl-4,5,6,7-tetrahydroindenyl) zirconium 
dichloride, rac-dimethylsilylene bis(2-methyl-4,5,6,7-tetrahydroindenyl) 
zirconium dimethyl, rac-ethylene bis(2-methyl-4,5,6,7-tetrahydroindenyl) 
hafnium dichloride, rac-dimethylsilylene bis(2-methyl-4-phenylindenyl) 
zirconium dichloride, rac-dimethylsilylene bis(2-methyl-4-phenylindenyl) 
zirconium dimethyl, rac-dimethylsilylene bis(2-methyl-4-phenylindenyl) 
hafnium dichloride, rac-dimethylsilylene bis(2-methyl-4-naphthylindenyl) 
zirconium dichloride, rac-dimethylsilylene bis(2-methyl-4-naphthylindenyl) 
zirconium dimethyl, rac-dimethylsilylene bis(2-methyl-4-naphthylindenyl) 
hafnium dichloride, rac-dimethylsilylene bis(2-methyl-4,5-benzoindenyl) 
zirconium dichloride, rac-dimethylsilylene bis(2-methyl-4,5-benzoindenyl) 
zirconium dimethyl, rac-dimethylsilylene bis(2-methyl-4,5-benzoindenyl) 
hafnium dichloride, rac-dimethylsilylene bis(2-ethyl-4-phenylindenyl) 
zirconium dichloride, rac-dimethylsilylene bis(2-ethyl-4-phenylindenyl) 
zirconium dimethyl, rac-dimethylsilylene bis(2-ethyl-4-phenylindenyl) 
hafnium dichloride, rac-dimethylsilylene 
bis(2-methyl-4,6-diisopropylindenyl) zirconium dichloride, 
rac-dimethylsilylene bis(2-methyl-4,6-diisopropylindenyl) zirconium 
dimethyl, rac-dimethylsilylene bis(2-methyl-4,6-diisopropylindenyl) 
hafnium dichloride, dimethylsilylene (2,4-dimethylcyclopentadienyl) 
(3',5'-dimethylcyclopentadienyl) titanium dichloride, dimethylsilylene 
(2,4-dimethylcyclopentadienyl) (3',5'-dimethylcyclopentadienyl) zirconium 
dichloride, dimethylsilylene (2,4-dimethylcyclopentadienyl) 
(3',5'-dimethylcyclopentadienyl) zirconium dimethyl, dimethylsilylene 
(2,4-dimethylcyclopentadienyl) (3',5'-dimethylcyclopentadienyl) hafnium 
dichloride, dimethylsilylene (2,4-dimethylcyclopentadienyl) 
(3',5'-dimethylcyclopentadienyl) hafnium dimethyl, dimethylsilylene 
(2,3,5-trimethylcyclopentadienyl) (2',4',5'-trimethylcyclopentadienyl) 
titanium dichloride, dimethylsilylene (2,3,5-trimethylcyclopentadienyl) 
(2',4',5'-trimethylcyclopentadienyl) zirconium dichloride, 
dimethylsilylene (2,3,5-trimethylcyclopentadienyl) 
(2',4',5'-trimethylcyclopentadienyl) zirconium dimethyl, dimethylsilylene 
(2,3,5-trimethylcyclopentadienyl) (2',4',5'-trimethylcyclopentadienyl) 
hafnium dichloride, dimethylsilylene (2,3,5-trimethylcyclopentadienyl) 
(2',4',5'-trimethylcyclopentadienyl) hafnium dimethyl, or the like. 
The compound (A) can be combined with the compound (B) or the compounds (B) 
and (C) as it is so as to prepare a catalyst. Alternatively, the compound 
(A) supported by a fine particle carrier can be used. As the fine particle 
carrier, an inorganic or organic compound in the form of a granular or 
spherical fine particle solid having a particle diameter of 5 to 300 
.mu.m, preferably 10 to 200 .mu.m can be used. 
Examples of the inorganic compound used as the carrier include SiO.sub.2, 
Al.sub.2 O.sub.3, MgO, TiO.sub.2, ZnO or the like, or the mixture thereof 
such as SiO.sub.2 --Al.sub.2 O.sub.3, SiO.sub.2 --MgO, SiO.sub.2 
TiO.sub.2, SiO.sub.2 --Al.sub.2 O.sub.3 --MgO or the like. Among these, a 
compound that comprises SiO.sub.2, or Al.sub.2 O.sub.3 as the main 
component is used preferably. 
Furthermore, examples of the organic compound used as the carrier include 
an .alpha.-olefin polymer or copolymer having 2 to 12 carbons such as 
ethylene, propylene, 1-butene, 4-methyl-1-pentene or the like, or a 
polymer or a copolymer of styrene or styrene derivatives. 
The compound (B) used in the present invention is at least one compound 
selected from aluminoxane (B-1), an ionic compound that reacts with the 
transition metal compound (A) so as to form an ionic complex (B-2) and 
Lewis acids (B-3). 
Aluminoxane (B-1) refers to an organic aluminum compound expressed by 
general formula 2 or 3. 
##STR1## 
where R.sup.3 is a hydrocarbon group having 1 to 6 carbons, preferably 1 
to 4 carbons, more specifically, an alkyl group such as a methyl group, an 
ethyl group, a propyl group, a butyl group, an isobutyl group, a pentyl 
group, a hexyl group or the like, an alkenyl group such as an allyl group, 
a 2-methylallyl group, a propenyl group, an isopropenyl group, a 
2-methyl-1-propenyl group, a butenyl group or the like, a cycloalkyl group 
such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a 
cyclohexyl group or the like, and an aryl group or the like. Among these, 
an alkyl group is most preferable, and R.sup.3 may be either the same or 
different. 
Furthermore, q is an integer of 4 to 30, preferably 6 to 30, and most 
preferably 8 to 30. 
The aluminoxane can be prepared under a variety of known conditions. 
Specific examples thereof are as follows: 
(1) By reacting trialkyl aluminum directly with water by using an organic 
solvent such as toluene, ether or the like; 
(2) By reacting trialkyl aluminum with salts having crystal water, e.g., a 
copper sulfate hydrate, an aluminum sulfate hydrate; 
(3) By reacting trialkyl aluminum with water impregnated in silica gel or 
the like; 
(4) By mixing trimethyl aluminum and triisobutyl aluminum and reacting the 
mixture directly with water by using an organic solvent such as toluene, 
ether or the like; 
(5) By mixing trimethyl aluminum and triisobutyl aluminum and reacting the 
mixture with salts having crystal water, e.g., a copper sulfate hydrate, 
and an aluminum sulfate hydrate; and 
(6) By impregnating silica gel or the like with water and reacting it with 
triisobutyl aluminum and then trimethyl aluminum. 
Furthermore, as for the ionic compound (B-2) that reacts with the 
transition metal compound (A) so as to form an ionic complex (hereinafter 
also referred to as "compound (B-2)") and the Lewis acid (B-3), the ionic 
compounds and the Lewis acids that are described in Japanese Laid-Open 
Patent Publication (Tokuhyo-Hei (Published Japanese translation of PCT 
international publication for patent application)) Nos. 1-501950 and 
1-502036, (Tokkai-Hei) Nos. 3-179005, 3-179006, 3-207703, 3-207704 or the 
like can be used. 
The ionic compound (B-2) that is usable in the present invention is a salt 
of a cationic compound and an anionic compound. The anion has a function 
of cationizing the transition metal compound (A) by reacting with the 
transition metal compound (A), so as to form an ion pair, so that 
transition metal cation species can be stabilized. Examples of such anions 
include organic boron compound anion, organic aluminum compound anion, or 
the like. Furthermore, examples of the cation include metal cation, 
organic metal cation, carbonium cation, tropylium cation, oxonium cation, 
sulfonium cation, phosphonium cation, ammonium cation or the like. 
Among these, an ionic compound comprising a boron atom as the anion is 
preferable, and specific examples thereof include tetrakis 
(pentafluorophenyl) triethylammonium borate, tetrakis (pentafluorophenyl) 
tri-n-butylammonium borate, tetrakis (pentafluorophenyl) triphenylammonium 
borate, tetrakis (pentafluorophenyl) methylanilinium borate, tetrakis 
(pentafluorophenyl) dimethylanilinium borate, tetrakis (pentafluorophenyl) 
trimethylanilinium borate, or the like. 
Furthermore, as the Lewis acid (B-3), a Lewis acid containing a boron atom 
is preferable, and the compounds expressed by the following formula can be 
used. 
EQU BR.sup.4 R.sup.5 R.sup.6 
(where R.sup.4, R.sup.5, and R.sup.6 represent a phenyl group which may 
have a substituent such as a fluorine atom, a methyl group, 
trifluorophenyl group or the like, or a fluorine atom, independently.) 
Specific examples of the compound expressed by the above general formula 
include tri(n-butyl) boron, triphenyl boron, 
tris[3,5-bis(trifluoromethyl)phenyl]boron, tris[(4-fluoromethyl) phenyl] 
boron, tris(3,5-difluorophenyl) boron, tris(2,4,6-trifluorophenyl) boron, 
tris(pentafluorophenyl) boron or the like. Among these, 
tris(pentafluorophenyl) boron is most preferable. 
The transition metal compound (A) and the compound (B) are preferably used 
in the following ratio. In the case where aluminoxane (B-1) is used as the 
compound (B), the aluminum atom in the aluminoxane (B-1) is preferably in 
the range from 1 to 50,000 mols, preferably 10 to 30,000 mols, and most 
preferably 50 to 20,000 mols, per mol of the transition metal atom in the 
transition metal compound (A). 
In the case where the compound (B-2) or Lewis acid (B-3) is used as the 
compound (B), the compound (B-2) or the Lewis acid (B-3) is preferably 
used in the range from 0.01 to 2,000 mols, preferably 0.1 to 500 mols, per 
mol of the transition metal atom in the transition metal compound (A). 
The compounds (B) as described above can be used singly or in combinations 
of two or more. 
Furthermore, as for the organic aluminum compound, which is the compound 
(C) used in the present invention, a compound expressed by the following 
formula can be used. 
EQU AlR.sup.7.sub.t R.sup.8.sub.t X.sub.3-(t+t') 
(where R.sup.7 and R.sup.8 represent a hydrocarbon group such as an alkyl 
group, a cycloalkyl group and an aryl group, or an alkoxyl group having 1 
to 10 carbons; X represents a halogen atom; and t and t' represent 
arbitrary numbers satisfying the inequality 0&lt;t+t'.ltoreq.3.) 
Specific examples of the compound expressed by the above formula include 
trialkyl aluminum such as trimethyl aluminum, triethyl aluminum, 
triisopropyl aluminum, triisobutyl aluminum, tri-n-butyl aluminum or the 
like, dialkyl aluminum halide such as dimethyl aluminum chloride, dimethyl 
aluminum bromide, diethyl aluminum chloride, diisopropyl aluminum chloride 
or the like, and alkyl aluminum sesquihalide such as methyl aluminum 
sesquichloride, ethyl aluminum sesquichloride, ethyl aluminum 
sesquibromide, isopropyl aluminum sesquichloride or the like. It is 
possible to use one or more compounds. 
The organic aluminum compound, the compound (C), is preferably used in such 
a ratio that the aluminum atom in the organic aluminum compound (C) is 
preferably in the range from 0 to 10,000 mols, preferably 0 to 5,000 mols, 
and most preferably 0 to 3,000 mols, per mol of the transition metal atom 
in the transition metal compound (A). 
The preactivation treatment is performed in the following manner: 0.0001 to 
5,000 mmols, preferably 0.001 to 1,000 mmols of the thus combined 
compounds are present, on the basis of the transition metal atom in the 
catalyst component, the compound (A), per liter of olefin 
(co)polymerization volume. Then, 1 g to 1,000 kg of olefin is supplied 
thereto and (co)polymerized in the absence of a solvent, or in the 
presence of a solvent in an amount less than 1000 liters per mmol of the 
transition metal atoms, so as to generate 1 g to 500 kg of olefin 
(co)polymer (a) per mmol of the transition metal atoms in the compound 
(A). 
In the specification of the present application, the term "polymerization 
volume" refers to a volume of the liquid phase portion in a polymerization 
reactor in the case of liquid phase polymerization, and a volume of the 
gas phase portion in a polymerization reactor in the case of gas phase 
polymerization. 
The amount of the compound (A) used is preferably within the 
above-mentioned range so as to maintain an efficient and controlled 
reaction rate of the olefin (co)polymerization. Furthermore, an 
excessively small amount of the compound (B) reduces the 
(co)polymerization reaction rate, and a large amount is also not 
preferable because the (co)polymerization reaction rate is not 
correspondingly raised. Furthermore, when the solvent is used in a large 
amount, not only is a large reactor required, but also it is difficult to 
control and maintain an efficient (co)polymerization reaction rate. 
The olefin (co)polymer (a) that is generated by the preactivation treatment 
has an intrinsic viscosity [.eta..sub.a ] measured in tetralin at 
135.degree. C. of 15 to 100 dl/g as described above, and can be either an 
olefin homopolymer having 2 to 12 carbons or an olefin copolymer having 2 
to 12 carbons, preferably an ethylene homopolymer or an ethylene-olefin 
copolymer containing at least 50 wt % ethylene polymerization units, more 
preferably an ethylene homopolymer or an ethylene-olefin copolymer 
containing at least 70 wt % ethylene polymerization units, and most 
preferably an ethylene homopolymer or an ethylene-olefin copolymer 
containing at least 90 wt % ethylene polymerization units. 
The olefin used in the preactivation treatment is not particularly limited, 
but olefin having 2 to 12 carbons is used preferably, as described above. 
Specific examples thereof include ethylene, propylene, 1-butene, 
1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene and 
3-methyl-1-pentene. Most preferably, ethylene is used as the main monomer. 
These olefins can be used in combinations of two or more. 
The preactivation treatment can be performed in a liquid phase using an 
aliphatic hydrocarbon such as butane, pentane, hexane, heptane, octane, 
isooctane, decane, and dodecane, an alicyclic hydrocarbon such as 
cyclopentane, cyclohexane, and methylcyclohexane, an aromatic hydrocarbon 
such as toluene, xylene, and ethylbenzene, or an inactive solvent such as 
gasoline fraction and hydrogenated diesel oil fraction, or in a liquid 
phase in which the olefin itself is used as a solvent; or in a gas phase 
without a solvent. 
The preactivation treatment can be performed in the presence of hydrogen, 
but it is preferable not to use hydrogen in order to generate high 
molecular weight olefin (co)polymer (a) having an intrinsic viscosity 
[.eta..sub.a ] of 15 to 100 dl/g. 
The preactivation treatment can be performed under any conditions, as long 
as a predetermined amount of the high molecular weight olefin (co)polymer 
(a) having an intrinsic viscosity [.eta..sub.a ] of 15 to 100 dl/g, 
preferably 17 to 50 dl/g, is generated. Generally, the preactivation 
treatment is performed at a relatively low temperature of the order of 
-40.degree. C. to 40.degree. C., preferably -40.degree. C. to 30.degree. 
C., and more preferably -40.degree. C. to 20.degree. C.; at a pressure of 
0.1 MPa to 5 MPa, preferably 0.2 MPa to 5 MPa, most preferably 0.3 MPa to 
5 MPa; for 1 min to 24 hours, preferably 5 min to 18 hours, and most 
preferably 10 min to 12 hours. 
Furthermore, in a more preferred embodiment of the present invention, 
before the preactivation treatment or before and after the preactivation 
treatment, the additional preactivation treatment can be performed so that 
an olefin (co)polymer (aa) having an intrinsic viscosity [.eta..sub.aa ] 
lower than the intrinsic viscosity [.eta..sub.a ] of the olefin 
(co)polymer (a) is formed in an amount of 1 g to 50 kg per mmol of the 
transition metal atoms in the compound (A). 
The additional preactivation treatment is generally at a temperature of -40 
to 100.degree. C. at a pressure of 0.1 to 5 MPa for 1 minute to 24 hours. 
The same kinds of catalyst component, solvent, olefin as those used in the 
preactivation treatment can be used for the additional preactivation 
treatment. 
The intrinsic viscosity [.eta..sub.aa ] of the olefin (co)polymer (aa) 
generated in the additional preactivation treatment is smaller than the 
intrinsic viscosity [.eta..sub.a ] of the olefin (co)polymer (a), and the 
olefin (co)polymer (aa) eventually forms a part of the olefin (co)polymer 
(b) of component (b) obtained after the main (co)polymerization. 
When the preactivation treatment alone is performed, whisker-like or 
massive olefin (co)polymers (a) may be generated under some conditions. 
Such olefin (co)polymers (a) may cause production problems such as the 
adhesion of the olefin (co)polymer to the walls of the preactivation 
reactor, the difficulty of taking the olefin (co)polymer out from the 
preactivation reactor, and the generation of massive (co)polymers in the 
main (co)polymerization. Furthermore, the olefin (co)polymers (a) may not 
be dispersed in the olefin (co)polymer (b) generated in the main 
(co)polymerization sufficiently, and the melt tension of the 
finally-obtained olefin (co)polymer composition is not improved 
sufficiently. On the other hand, when the additional preactivation 
treatment is performed, the obtained catalyst slurry has a better shape 
and not only are the problems in the production solved, but also the 
olefin (co)polymer (aa) generated in the additional preactivation 
treatment is dispersed in the olefin (co)polymer (b) sufficiently, because 
the intrinsic viscosity [.eta..sub.aa ] of the olefin (co)polymer (aa) is 
smaller than the intrinsic viscosity [.eta..sub.a ] of the olefin 
(co)polymer (a) generated in the preactivation treatment. As a result, the 
melt tension of the finally-obtained olefin (co)polymer composition is 
improved sufficiently. 
Therefore, it is a more preferable embodiment that the intrinsic viscosity 
[.eta..sub.aa ] of the olefin (co)polymer (aa) is larger than the 
intrinsic viscosity [.eta..sub.b ] of the olefin (co)polymer (b) generated 
in the main (co)polymerization. 
The thus obtained preactivated catalyst or additionally preactivated 
catalyst is used to (co)polymerize olefin having 2 to 12 carbons so as to 
produce an olefin (co)polymer (b) as an olefin main (co)polymerization 
catalyst without further components or with additional component (B) 
and/or component (C). 
Furthermore, in the present invention, other than the preactivated catalyst 
or the additionally preactivated catalyst as described above, it is 
possible to use the catalyst added with a known transition metal catalyst 
component of a so-called Ziegler-Natta catalyst comprising titanium 
trichloride or titanium tetrachloride or titanium trichloride or titanium 
tetrachloride supported by magnesium chloride or the like. Hereinafter, in 
the case where a transition metal catalyst component of a known 
Ziegler-Natta catalyst is added, the expression "preactivated catalyst" 
also means a preactivated catalyst comprising the additional transition 
metal catalyst component. 
The catalyst for olefin main (co)polymerization can be used in the same 
amount range of that at the time of the preactivation treatment of the 
present invention as described above, including the additional components 
(B) and (C) that are added, if necessary, at the time of the main (co) 
polymerization. 
The compounds (B) and (C) that are added, if necessary, to the catalyst for 
olefin main (co)polymerization may be the same as those used in the 
preactivation treatment or different therefrom. 
As the catalyst for olefin main (co)polymerization, powder particles 
obtained by filtration or decantation for removing the solvent, unreacted 
olefin, the compounds (B) and (C) present in the preactivated catalyst, or 
a suspension of the powder particles added with a solvent may be combined 
with the compounds (B) and/or (C). Alternatively, powder particles 
obtained by evaporating the solvent and unreacted olefin present in the 
preactivated catalyst by vacuum distillation, inert gas stream or the 
like, or a suspension of the powder particles added with a solvent may be 
combined with the compounds (B) and/or (C), if desired. 
The olefin (co)polymer (a) constituting the component (a) of the olefin 
(co)polymer composition of the present invention has an intrinsic 
viscosity [.eta..sub.a ] measured in tetralin at 135.degree. C. of 15 to 
100 dl/g, and can be either a homopolymer or a copolymer of olefin having 
2 to 12 carbons, preferably an ethylene homopolymer or an ethylene-olefin 
copolymer containing at least 50 wt % ethylene polymerization units, more 
preferably an ethylene homopolymer or an ethylene-olefin copolymer 
containing at least 70 wt % ethylene polymerization units, and most 
preferably an ethylene homopolymer or an ethylene-olefin copolymer 
containing at least 90 wt % ethylene polymerization units. These 
(co)polymers can be used alone, or in combinations of two or more. 
The intrinsic viscosity [.eta..sub.a ] of the olefin (co)polymer (a) is 
suitably in the range from 15 to 100 dl/g, preferably 17 to 50 dl/g, so 
that the melt tension and the crystallization temperature of the 
finally-obtained olefin (co)polymer composition can be improved, the 
olefin (co)polymer (a) can be dispersed in the olefin (co)polymer (b) 
generated in the main (co)polymerization sufficiently, and the production 
efficiency can be raised. 
The olefin constituting the component of the olefin (co)polymer (a) is not 
particularly limited, but an olefin having 2 to 12 carbons is preferably 
used, as described above. Specific examples thereof include ethylene, 
propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 
4-methyl-1-pentene, and 3-methyl-1-pentene. Most preferably, ethylene is 
used as the main monomer. These olefins can be used alone or in 
combinations of two or more. 
The density of the olefin (co)polymer (a) is not particularly limited, but 
specifically, about 880 to 980 g/l is preferable. 
The olefin (co)polymer (b) of the component (b) constituting the olefin 
(co)polymer composition of the present invention is an olefin (co)polymer 
having an intrinsic viscosity [.eta..sub.b ] measured in tetralin at 
135.degree. C. of 0.2 to 10 dl/g, and can be either a homopolymer or a 
copolymer of an olefin having 2 to 12 carbons, but preferably a propylene 
homopolymer, or a propylene-olefin random copolymer or a propylene-olefin 
block copolymer containing at least 50 wt % propylene polymerization 
units, more preferably a propylene homopolymer, or a propylene-olefin 
random copolymer containing at least 90 wt % propylene polymerization 
units, or an propylene-olefin block copolymer containing at least 70 wt % 
propylene polymerization units. These (co)polymers can be used alone, or 
in combinations of two or more. 
The intrinsic viscosity [.eta..sub.b ] of the olefin (co)polymer (b) is in 
the range from 0.2 to 10 dl/g, preferably 0.5 to 8 dl/g, in terms of the 
mechanical characteristics and formability of the finally-obtained olefin 
(co)polymer composition. The olefins constituting the olefin (co)polymer 
(b) are not particularly limited, but an olefin having 2 to 12 carbons is 
used preferably, as described above. Specific examples thereof include 
ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 
4-methyl-1-pentene, and 3-methyl-1-pentene. Most preferably, propylene is 
used as the main monomer. These olefins can be used alone or in 
combinations of two or more. 
Furthermore, the olefin (co)polymer (b) of the component (b) of the present 
invention is obtained by (co)polymerizing olefins with a catalyst 
comprising the components (A) and (B) or the components (A), (B) and (C), 
as described above. 
A specific catalyst comprising the thus combined components (A) and (B) or 
components (A), (B) and (C) is used to (co)polymerize olefins so as to 
obtain the olefin (co)polymer (b) used in the composition of the present 
invention. The olefin (co)polymerization can be effected in a known olefin 
(co)polymerization process, for example, a slurry polymerization method in 
which olefin is (co)polymerized in an aliphatic hydrocarbon such as 
butane, pentane, hexane, heptane, and isooctane, an alicyclic hydrocarbon 
such as cyclopentane, cyclohexane and methylcyclohexane, an aromatic 
hydrocarbon such as toluene, xylene and ethylbenzene, or an inactive 
solvent such as gasoline fraction and hydrogenated diesel oil fraction; 
bulk polymerization in which the olefin itself is used as a solvent; and a 
gas phase polymerization method in which olefin (co)polymerization is 
effected in the gas phase; and solution polymerization in which polyolefin 
generated in the (co)polymerization is in the form of liquid. Two or more 
of the above-mentioned polymerization processes can be combined. 
In polymerizing olefin, for the specific catalyst, the compounds (A) and 
(B), or (A), (B) and (C) may be previously mixed in an inactive solvent, 
and then the mixture may be supplied to a polymerization reaction system. 
Alternatively, the compounds (A) and (B), or (A), (B) and (C) may be 
supplied to a polymerization reaction system separately. Furthermore, the 
following process is effective to obtain an olefin (co)polymer (b) having 
satisfactorily shaped particles: Prior to the main polymerization of 
olefin, a preactivation treatment is performed in which a small amount of 
olefin, more specifically, about 1 g to 500 kg of olefin per mmol of the 
transition metal in the compound (A), is reacted for polymerization with a 
catalyst comprising the compounds (A) and (B) or (A), (B) and (C) in an 
inactive solvent, so as to prepare a preactivated catalyst. Then, the main 
polymerization of olefin is performed. This is also in the scope of the 
present invention. 
A preferable olefin that can be used in the preactivation treatment is 
.alpha.-olefin having 2 to 12 carbons. Specific examples thereof include 
ethylene, propylene, butene, pentene, hexene, octene and 
4-methyl-1-pentene. Among these, ethylene, propylene and 
4-methyl-1-pentene can be used preferably. 
The thus prepared specific catalyst or the preactivated specific catalyst 
used in the present invention is used for the polymerization of olefin by 
the above-mentioned polymerization methods. As for the polymerization 
conditions in the propylene polymerization, the same polymerization 
conditions as in the olefin (co)polymerization with a known Ziegler-Natta 
catalyst are adopted. More specifically, the polymerization is performed 
at a temperature of -50 to 150.degree. C., preferably -10 to 100.degree. 
C.; at a pressure from the atmospheric pressure to 7 MPa, preferably 0.2 
MPa to 5 MPa; generally for 1 min to 20 hours in the presence of hydrogen 
acting as a molecular weight modifier so that the intrinsic viscosity 
[.eta..sub.b ] measured in tetralin at 135.degree. C. of the obtained 
olefin (co)polymer (b) is 0.2 to 10 dl/g. 
After the (co)polymerization of olefin is complete, known post-treatment 
processes such as a catalyst deactivating treatment process, a catalyst 
residue removing process and a drying process are performed, if necessary. 
Therefore, an olefin (co)polymer (b) having an intrinsic viscosity 
[.eta..sub.b ] measured in tetralin at 135.degree. C. of 0.2 to 10 dl/g 
can be obtained for use in the present invention. 
The olefin (co)polymer composition of the present invention comprises 0.01 
to 5 parts by weight, preferably 0.02 to 2 parts by weight, and most 
preferably 0.05 to 1 part by weight, of the olefin (co)polymer (a) of the 
component (a) and 100 parts by weight of the olefin (co)polymer (b) of the 
component (b). 
The amount of the olefin (co)polymer (a) of the component (a) is preferably 
in the above-mentioned range in view of the improvement of the melt 
tension and the crystallization temperature of the obtained olefin 
(co)polymer composition and the homogeneity of the composition. 
The olefin (co)polymer composition of the present invention preferably has 
a melt tension (MS) at 230.degree. C. and a melt flow index (MFR) measured 
under a load of 21.18N at 230.degree. C. that satisfy the following 
inequality: 
EQU log (MS)&gt;-1.28.times.log (MFR)+0.44. 
Although the upper limit is not particularly limited, it is preferably such 
that the following inequality is satisfied: 
-1.28.times.log (MFR)+2.06&gt;log (MS)&gt;-1.28.times.log (MFR)+0.44, more 
preferably, 
-1.28.times.log (MFR)+2.06&gt;log (MS)&gt;-1.28.times.log (MFR)+0.54, most 
preferably, 
-1.28.times.log (MFR)+1.76&gt;log (MS)&gt;-1.28.times.log (MFR)+0.66, because an 
excessively high melt tension deteriorates the formability of the 
composition. 
The melt tension at 230.degree. C. is a value (unit: cN) obtained by using 
the MELT TENSION II (manufactured by TOYO SEIKI SEISAKU-SHO, Ltd), heating 
the polypropylene composition to 230.degree. C. in the equipment, 
extruding the molten polypropylene composition through a nozzle of a 
diameter of 2.095 mm at a rate of 20 mm/min to the air of 23.degree. C. so 
as to make a strand, and measuring the tension of a thread like 
polypropylene composition when taking up the strand at a rate of 3.14 
m/min. 
Any methods can be used for producing the polypropylene composition of the 
present invention, even if the melt tension of the composition is a high 
value as shown in the above-mentioned range. However, the composition is 
more easily produced by the following method: A preactivation treatment is 
performed to (co)polymerize olefins with a metallocene based-catalyst for 
olefin (co)polymerization so as that a small amount of olefin (co)polymer 
(a) having a specific intrinsic viscosity is generated, prior to the main 
(co)polymerization. Thus, a preactivated catalyst is prepared. The main 
(co)polymerization of olefins is performed with the preactivated catalyst 
so as to produce the olefin (co)polymer (b), and thus a final olefin 
(co)polymer is obtained. 
In a method for producing the olefin (co)polymer composition of the present 
invention, the preactivated catalyst is used in an amount of 0.0001 to 
5,000 mmols, preferably 0.001 to 1000 mmols per liter of the 
polymerization volume, on the basis of the transition metal atom in the 
preactivated catalyst. The transition metal compound catalyst component is 
used in the above-mentioned amount, so that an efficient and controlled 
reaction rate of the olefin (co)polymerization can be maintained. 
The main (co)polymerization of olefins with the preactivated catalyst in 
the present invention can be effected in the known olefin 
(co)polymerization processes and the polymerization conditions described 
when producing the olefin (co)polymer (b). 
In the method for producing the olefin (co)polymer composition of the 
present invention, the polymerization conditions are selected so that the 
olefin (co)polymer (a) derived from the preactivated catalyst used is 
produced in an amount of 0.01 to 5 parts by weight on the basis of 100 
parts by weight of the olefin (co)polymer (b) generated in the main 
(co)polymerization. 
After the main (co)polymerization is complete, known post-treatment 
processes such as a catalyst deactivating treatment process, a catalyst 
residue removing process, a drying process or the like are performed, if 
necessary. Thus, a targeted olefin (co)polymer composition having a high 
melt tension and a high crystallization temperature can be obtained as a 
final product. 
In the method for producing the olefin (co)polymer composition of the 
present invention, the olefin (co)polymer (a) having a high intrinsic 
viscosity is generated by the preactivation treatment process, and is 
dispersed in the finally-obtained olefin (co)polymer composition 
uniformly. Therefore, it is possible to prepare a necessary amount of the 
preactivated catalyst in a large amount. Moreover, since regular olefin 
(co)polymerization by using a known process can be used for the main 
(co)polymerization of olefin, the production amount is equivalent to that 
in regular olefin (co)polymer production using a metallocene catalyst. 
By using the method for producing the olefin (co)polymer composition 
employing the preactivated catalyst of the present invention, it is 
possible to obtain easily an olefin (co)polymer composition that satisfies 
the above-mentioned relationship between the melt tension (MS) at 
230.degree. C. and the melt low index (MFR) at 230.degree. C. under a load 
of 21.18N. 
The obtained olefin (co)polymer composition can be mixed with a variety of 
additives such as an antioxidant, an ultraviolet absorber, an antistatic 
agent, a nucleating agent, a lubricant, a flame retardant, an 
anti-blocking agent, a coloring agent, an inorganic or organic filler, or 
a variety of synthetic resins, if necessary. Then, the composition is 
generally heated, melted and kneaded, and then cut into granular pellets 
for formation in a variety of molds. 
Hereinafter, the present invention will be more specifically described by 
way of examples and comparative examples. 
The definition of terms and measurement methods used in the Examples and 
Comparative Examples are as follows. 
(1) Intrinsic viscosity [.eta.] a value (unit: dl/g) as a result of 
measurement by an Ostwald's viscometer (manufactured by Mitsui Toatsu 
Chemicals, Inc.) of an intrinsic viscosity measured in tetralin at 
135.degree. C. 
(2) Melt flow rate (MFR): a value (unit: g/10 min.) as a result of 
measurement under the condition 14 (under a load of 21.18 N at 230.degree. 
C.) of Table 1 according to JIS K7210. 
(3) Melt tension (MS): a value (unit: cN) as a result of measurement by 
using MELT TENSION II (manufactured by TOYO SEIKI SEISAKU-SHO, Ltd). 
(4) Crystallization temperature (Tc): a temperature (unit:.degree. C.) at a 
peak of crystallization obtained by using a differential scanning 
calorimeter VII (manufactured by PERKIN-ELMER Ltd.), warming the olefin 
(co)polymer composition from room temperature to 230.degree. C. at 
30.degree. C/min, allowing it to stand at 230.degree. C. for 10 min., 
cooling it to -20.degree. C. at -20.degree. C/min., allowing it to stand 
at -20.degree. C. for 10 min., warming it to 230.degree. C. at 20.degree. 
C/min, allowing it to stand at 230.degree. C. for 10 min., cooling it to 
150.degree. C. at -80.degree. C/min, and further cooling it from 
150.degree. C. at -5.degree. C/min to reach the maximum peak of 
crystallization. 
(5) Heat stability: 0.1 parts by weight of 2,6-di-t-butyl-p-cresol and 0.1 
parts by weight of calcium stearate are mixed with 100 parts by weight of 
the olefin (co)polymer composition. The mixture is melted, kneaded and 
pelletized by an extruder with a screw having a diameter of 40 mm at 
230.degree. C., and thus pellets of the olefin (co)polymer composition are 
prepared. 
Heat stability is calculated as follows: The obtained pellets and the 
pellets finally obtained as a result of further repeating melting and 
kneading, and pelletizing the obtained pellets by the extruder twice are 
measured according to the condition 14 of Table 1 of JIS K7210, so that a 
difference between the MFR of the finally-obtained pellets and MFR of the 
firstly-obtained pellets (the finally-obtained pellet MFR--the 
firstly-obtained pellet MFR=.DELTA.MFR) was calculated. 
A smaller difference (.DELTA.MFR) indicates better heat stability. 
EXAMPLE 1 
(1) Production of Preactivated Catalyst 
The air in a stainless steel reactor provided with an inclined turbine 
agitator having an inner volume of 20 dm.sup.3 was replaced with a 
nitrogen gas. Then, 10 dm.sup.3 of toluene, 12.0 mol (on the basis of Al 
atom) of a toluene solution of methylaluminoxane (product name: MMAO 
manufactured by TOSOH AKZO CORPORATION, a concentration of 2 mol/dm.sup.3) 
and a mixture as metallocene of 5.92 mmol of chiral dimethylsilylene 
(2,3,5-trimethylcyclopentadienyl) (2',4',5'-trimethylcyclopentadienyl) 
hafnium dichloride and 0.20 mmol of dimethylsilylene 
(2,3,5-trimethylcyclopentadienyl) (2',3',5'-trimethylcyclopentadienyl) 
hafium dichloride of a meso compound together with 1 dm.sup.3 of toluene 
were introduced into the reactor at 20.degree. C. Then, after the 
temperature in the reactor is lowered to 0.degree. C., 14 g of propylene 
was supplied to the reactor so as to perform an additional preactivation 
treatment at 0.degree. C. for 20 minutes. 
When polymers generated by an additional preactivation treatment under the 
same conditions separately were analyzed, it was found that polypropylene 
(aa) having an intrinsic viscosity [.eta..sub.aa ] of 4.7 dl/g measured in 
tetralin at 135.degree. C. was generated in an amount of 8 g. 
After the reaction time passed, unreacted propylene was discharged from the 
reactor, and the gas phase in the reactor was replaced with nitrogen once. 
Then, ethylene was supplied to the reactor continuously for one hour while 
maintaining the temperature in the reactor at -20.degree. C. and the 
pressure n the reactor at 0.59 MPa, so as to perform a preactivation 
treatment. 
Separately, an additional preactivation treatment and a preactivation 
treatment were performed under the same conditions, and the generated 
polymers were analyzed. As a result, it was found that polymers having an 
intrinsic viscosity [.eta..sub.T ] of 27.0 dl/g when measured in tetralin 
at 135.degree. C. were generated in an amount of 80 g. 
The amount (W.sub.a) of the polyethylene (a) generated by the preactivation 
treatment with ethylene can be obtained by the following equation as a 
difference between the amount (W.sub.T) of the polymer generated after the 
treatment comprising the additional preactivation treatment and the 
preactivation treatment and the amount (W.sub.aa) of the polypropylene 
(aa) after the additional preactivation treatment. 
EQU W.sub.a =W.sub.T -W.sub.aa 
The intrinsic viscosity [.eta..sub.a ] of the polyethylene (a) generated by 
the preactivation treatment with ethylene can be obtained from the 
intrinsic viscosity [.eta..sub.aa ] of the polypropylene (aa) generated by 
the additional preactivation treatment and the intrinsic viscosity 
[.eta..sub.T ] of the polymers generated after the treatment comprising 
the additional preactivation treatment and the preactivation treatment by 
the following equation. 
EQU [.eta..sub.a ]=([.eta..sub.T ].times.W.sub.T -[.eta..sub.aa 
].times.W.sub.aa)/(W.sub.T -W.sub.aa) 
According to the above equation, the amount of the polyethylene (a) 
generated by the preactivation treatment with ethylene was 72 g, and the 
intrinsic viscosity [.eta..sub.a ] thereof was 29.5 dl/g. After the 
reaction time passed, unreacted ethylene was discharged out of the 
reactor, and the gas phase in the reactor was replaced with nitrogen once, 
thus producing a preactivated catalyst slurry for the main 
(co)polymerization. 
(2) Production of Olefin (co)polymer composition (Main (co)polymerization 
of propylene) 
The air in a stainless steel reactor with an agitator having an inner 
volume of 100 dm.sup.3 was replaced with a nitrogen gas. Then, 50 dm.sup.3 
of toluene, 8.0 mol (on the basis of Al atom) of a toluene solution of 
methylaluminoxane (product name: MMAO manufactured by TOSOH AKZO 
CORPORATION, a concentration of 2 mol/dm.sup.3) and a fourth of the amount 
of the preactivated catalyst slurry obtained in the above section (1) were 
introduced into the polymerization reactor. After the temperature in the 
polymerization reactor became 30.degree. C., propylene was supplied to the 
polymerization reactor continuously for four hours at a temperature of 
30.degree. C. while maintaining the pressure in the gas phase portion in 
the polymerization reactor at 0.4 MPa, so as to perform the main 
polymerization of propylene. 
After the polymerization was complete, unreacted propylene was discharged 
out of the polymerization reactor. Thereafter, 3 dm.sup.3 of 2-propanol 
was introduced to the polymerization reactor, so as to deactivate the 
catalyst while stirring at 30.degree. C. for 10 min. Then, 0.2 dm.sup.3 of 
an aqueous solution of hydrogen chloride (concentration: 12 mol/dm.sup.3) 
and 8 dm.sup.3 of methanol were added, and treated at 60.degree. C. for 30 
min. Thereafter, stirring was stopped, and the water phase portion was 
removed from the lower part of the polymerization reactor, the same amount 
of aqueous solution of hydrogen chloride and methanol were added and the 
same operation was repeated. Then, 0.02 dm.sup.3 of an aqueous solution of 
sodium hydroxide (concentration: 5 mol/dm.sup.3), 2 dm.sup.3 of water and 
2 dm.sup.3 of methanol were added, and stirred at 30.degree. C. for 10 
min. Thereafter, stirring was stopped, and the water phase portion was 
removed from the lower part of the polymerization reactor, and 8 dm.sup.3 
of water was further added and stirred at 30.degree. C. for 10 min, and 
the water phase portion was removed. This operation was repeated twice. 
Thereafter, a polymerized slurry was extracted from the polymerization 
reactor, and filtered and dried. Thus, a polypropylene composition of the 
olefin (co)polymer composition of the present invention having an 
intrinsic viscosity [.eta..sub.TT ] of 1.93 dl/g was obtained in an amount 
of 3.6 kg. 
The analysis results of the obtained polypropylene composition and the 
calculation results of the amount and the intrinsic viscosity [.eta.] of 
the polyethylene (a) generated in the above-described preactivation 
treatment make it possible to calculate the total amount (W.sub.b) of the 
polypropylene (b) with the following equation, because the polypropylene 
(aa) generated in the additional preactivation treatment can be regarded 
as part of the polypropylene (b). 
EQU W.sub.b =W.sub.TT -W.sub.a 
where W.sub.a represents the total amount (72 g.times.1/4=18 g) of the 
polyethylene (a) in the final polypropylene composition, and WT represents 
the whole amount (3600 g) of the polypropylene composition. Therefore, 
when the amount (W.sub.b) of the polypropylene (b) is 100 parts by weight, 
the parts by weight (W.sub.Ra) of the polyethylene (a) can be calculated 
with the following equation: 
EQU W.sub.Ra =W.sub.a .times.100/W.sub.b 
The intrinsic viscosity [.eta..sub.b ] of the polypropylene (b) can be 
calculated with the following equation. 
EQU [.eta..sub.b ]=([.eta..sub.TT ].times.W.sub.TT -[.eta..sub.a 
].times.W.sub.a)/(W.sub.TT -W.sub.a) 
where [.eta..sub.TT ] represents the intrinsic viscosity [.eta.] of the 
entire polypropylene composition, and [.eta..sub.a ] represents the 
intrinsic viscosity [.eta.] of the polyethylene (a) generated in the 
above-described preactivated treatment. W.sub.TT and W.sub.b are the same 
as above. 
According to the above equation, the parts by weight of the polyethylene 
(a) was 0.50 parts by weight, and the intrinsic viscosity [.eta.] of the 
polypropylene (b) was 1.79 dl/g. 
0.1 parts by weight of 2,6-di-t-butyl-p-cresol and 0.1 parts by weight of 
calcium stearate were mixed with 100 parts by weight of the obtained 
polypropylene composition, and the mixture was pelletized by an extruder 
with a screw having a diameter of 40 mm at 230.degree. C. so that pellets 
were produced. When various properties of the pellets were evaluated, the 
results were such that the MFR was 2.8 g/10 min, the crystallization 
temperature was 124.3.degree. C. and the melt tension (MS) was 1.8 cN. 
Other properties are shown in Table 1. 
COMATIVE EXAMPLE 1 
Polypropylene was produced under the same conditions as in Example 1, 
except that the preactivation treatment with ethylene was not performed. 
An evaluation sample for Comparative Example 1 was prepared from the 
obtained polypropylene. The properties of the obtained polypropylene 
composition are shown in Table 1. 
EXAMPLES 2 AND 3, AND COMATIVE EXAMPLE 2 
A polypropylene composition was produced under the same conditions as in 
Example 1, except that the conditions for the preactivation treatment with 
ethylene were changed to change the intrinsic viscosity [.eta.] of 
polyethylene (a) and the amount of polyethylene (a) to be generated. Thus, 
evaluation samples for Examples 2 and 3 and Comparative Example 2 were 
prepared. The properties of the obtained polypropylene composition are 
shown in Table 1. 
COMATIVE EXAMPLE 3 
The air in a reactor provided with an inclined turbine agitator was 
replaced with nitrogen gas. Then, 10 kg of propylene homopolymer powder 
having an intrinsic viscosity [.eta.] of 1.67 dl/g and an average particle 
diameter of 150 .mu.m was placed therein. The propylene homopolymer powder 
was obtained by slurry polymerization of propylene in n-hexane with a 
catalyst comprising a titanium-containing catalyst component comprising a 
titanium trichloride composition, diethylaluminum chloride and a third 
component, diethyleneglycoldimethylether. Then, the reactor was evacuated 
and the operation of supplying a nitrogen gas until reaching the 
atmospheric pressure was repeated 10 times. Thereafter, 0.35 mol of 70 wt 
% di-2-ethylhexyl peroxy dicarbonate (modifier) in a toluene solution was 
added and mixed therewith at 25.degree. C. Then, the temperature in the 
reactor was raised to 120.degree. C., and the mixture was reacted at that 
temperature for 30 minutes. After the reaction time passed, the 
temperature in the reactor was raised to 135.degree. C., and a post 
treatment was performed at that temperature for 30 minutes. After the post 
treatment, the reactor was cooled to room temperature and the reactor was 
opened so as to obtain polypropylene. 
0.1 parts by weight of 2,6-di-t-butyl-p-cresol and 0.1 parts by weight of 
calcium stearate were mixed with 100 parts by weight of the obtained 
polypropylene, and the mixture was pelletized by an extruder with a screw 
having a diameter of 40 mm at 230.degree. C. so that pellets were 
produced. Thus, an evaluation sample for Comparative Example 3 was 
prepared. Then, various properties of the obtained pellets were evaluated. 
The results are shown in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Example and Comparative 
Com. 
Com. Com. 
Example .No. Ex. 1 
Ex. 1 
Ex. 2 
Ex. 2 
Ex. 3 
Ex. 3 
__________________________________________________________________________ 
PO*.sup.1) (a) 
Intrinsic viscosity[.eta.] (dl/g) 
29.5 
-- 9.2 29.5 
21.2 
-- 
Parts by weight 
0.50 
-- 0.11 
0.10 
0.69 
-- 
PO*.sup.2) (b) 
Intrinsic viscosity[.eta.] (dl/g) 
1.79 
1.79 
1.79 
1.79 
1.79 
-- 
Parts by weight 
100 100 100 100 100 -- 
Olefin 
Intrinsic viscosity[.eta.] (dl/g) 
1.93 
1.79 
1.80 
1.82 
1.93 
1.68 
(co)polymer 
composition 
Melt tension (MS) (cN) 
1.8 0.4 0.4 1.1 1.2 7.2 
Crystallization 
124.3 
118.0 
118.8 
123.5 
122.4 
129.4 
Temperature (Tc) (.degree. C.) 
First pellet MFR (g/10 min) 
2.8 4.0 3.9 3.7 2.8 9.2 
Final pellet MFR (g/10 min) 
3.0 4.3 4.2 3.9 3.0 17.5 
.increment.MFR (g/10 min) 
0.2 0.3 0.3 0.2 0.2 8.3 
__________________________________________________________________________ 
Note: *.sup.1 represents olefln (co)polymer (a). 
*.sup.2 represents olefin (co)polymer (b). 
EXAMPLE 4 
A polypropylene composition was produced under the same conditions as in 
Example 1, except that in place of propylene, a mixed gas of 1 mol % of 
ethylene and 99 mol % of propylene was supplied to the polymerization 
reactor in the main polymerization of propylene, so that 
ethylene-propylene copolymerization was effected. Thus, an evaluation 
sample for Example 4 was prepared. The properties of the obtained 
polypropylene composition are shown in Table 2. 
EXAMPLE 5 
A polypropylene composition was produced under the same conditions as in 
Example 1, except that 0.15 mol of hydrogen also was supplied to the 
polymerization reactor immediately before the main polymerization of 
propylene. Thus, an evaluation sample for Example 5 was prepared. The 
properties of the obtained polypropylene composition are shown in Table 2. 
COMATIVE EXAMPLE 4 
A polypropylene composition was produced under the same conditions as in 
Comparative Example 1, except that 0.15 mol of hydrogen also was supplied 
to the polymerization reactor immediately before the main polymerization 
of propylene. Thus, evaluation samples for Comparative Examples 4 were 
prepared. The properties of the obtained polypropylene compositions are 
shown in Table 2. 
TABLE 2 
______________________________________ 
Com. 
Example and Comparative Example .No. 
Ex. 4 Ex. 5 Ex. 4 
______________________________________ 
PO*.sup.1) 
Intrinsic viscosity[.eta.] (dl/g) 
29.5 29.5 -- 
(a) Parts by weight 0.42 0.51 -- 
PO*.sup.2) 
Intrinsic viscosity[.eta.] (dl/g) 
1.81 1.51 1.51 
(b) Parts by weight 100 100 100 
Olefin Intrinsic viscosity[.eta.] (dl/g) 
1.93 1.65 1.51 
(co)polymer 
Melt tension (MS) (cN) 
1.7 1.5 0.1 
composition 
Crystallization 123.1 124.6 118.2 
Temperature (Tc) (.degree. C.) 
First pellet MFR (g/10 min) 
2.8 5.8 8.9 
Final pellet MFR (g/10 min) 
3.0 6.1 9.3 
.increment.MFR (g/10 min) 
0.2 0.3 0.4 
______________________________________ 
Note: *.sup.1 represents olefin (co)polymer (a). 
*.sup.2 represents olefin (co)polymer (b). 
Industrial Applicability 
As described above, according to the present invention, an olefin 
(co)polymer having a high melt tension, a high crystallization temperature 
and excellent heat stability can be produced by combining (A) a transition 
metal compound having at least one .pi. electron conjugated ligand; and 
(B) at least one compound selected from aluminoxane, an ionic compound 
that reacts with the transition metal compound (A) so as to form an ionic 
complex, and a Lewis acid; or by combining the compounds (A) and (B), and 
(C) an organic aluminum compound, and (co)polymerizing olefin so that an 
olefin (co)polymer (a) having an intrinsic viscosity [.eta..sub.a ] 
measured in tetralin at 135.degree. C. of 15 to 100 dl/g was produced in 
an amount of 1 g to 500 kg per mmol of transition metal in the compound 
(A). This is especially useful for main polymerization of propylene. 
Furthermore, the polypropylene composition of the present invention is 
excellent in formability because the melt tension and the crystallization 
temperature are high, as shown in the Examples, and is also excellent in 
heat stability, so that the productivity in the forming process is high. 
In addition, the composition is formed into a molded product, and after 
use, the molded product can be melted and reused in a further molding 
process. Moreover, the composition can be subjected to blow molding, foam 
molding, extrusion molding, injection molding, T-die molding, 
thermoforming or the like so as to produce various container such as a 
hollow container, or various molds such as a film, a sheet, a pipe and a 
fiber. Thus, the field of utilization for polypropylene can be expanded 
significantly.