Propylene polymer and composition containing the same, molded object and laminate comprising these, and processes for producing propylene polymer and composition containing the same

Technical Field

0001The present invention relates to a propylenic polymer which has an excellent melt flowability, contains a less amount of stickiness-causing components, has a low modulus and is pliable, and is capable of providing a transparent molded article, thus being useful as a substitute for a pliable vinyl chloride resin, a method for producing the same, a propylenic resin composition and a molded article made therefrom; a propylenic polymer composition which is excellent in terms of heat seal performance at a low temperature and moldability, and is capable of providing a film or a molded article which is excellent in terms of transparency and rigidity, as well as a molded article, a film or a laminated article made therefrom.

0002More particularly, the invention relates to a transition metal compound and a polymerization catalyst employed preferably in a polymerization of an olefinic resins mentioned above.

Background of the Invention

0003A vinyl chloride resin which has widely been employed as a pliable synthetic resin is known to generate a hazardous material during a combustion process, because of which a development of a substitute of a vinyl chloride resin is desired. One substitute for a pliable vinyl chloride resin is a propylenic polymer. While a propylenic polymer is produced in the presence of various catalyst, a propylenic polymer produced using a conventional catalyst system involves a disadvantageously increased amount of stickiness-causing components as a result of an attempt to impart a pliability (i.e. a low modulus). The increase in the amount of stickiness-causing atactic polypropylenes (hereinafter referred to as APP) leads to a deteriorated surface condition of a molded article obtained.

0004On the other hand, an application of a molded article in a form of a sheet or a film to a food product or a medical use may involve various problems. Accordingly, a propylenic polymer having a more satisfactorily weighed relationship between a low level of the modulus and the quantity of the stickiness-causing components is desired.

0005Since a propylenic polymer generally has a greater supercooling degree required for initiating a crystallization when compared with an ethylenic polymer, it provides a resin characterized by a lower crystallization temperature even if it has a same melting point. Accordingly, it may cause a problematically poor molding performance especially with a heat seal grade product having a low melting point. In an attempt to reduced the heat seal temperature, a method for reducing the stereoregularity index of a propylenic polymer is employed, or a copolymer with other olefins is used. Among those produced in such attempt, a conventional low stereoregular propylenic polymer obtained by using a Ziegler catalyst system has a broad stereoregularity distribution, and an attempt to obtain a pliable polymer (i.e. having a low modulus) results in an increase in the amount of stickiness-causing components, including one derived fromAPP which causes a poor physical property of a low stereoregular propylenic polymer, such as a poor surface condition of a molded article once such propylenic polymer is molded. Thus, it is desired to obtain a film, a fiber, a sheet or a molded article in which a low melting point and a very narrow stereoregularity distribution possessed by a low stereoregular polymer are still preserved and which has an excellent transparency and a low temperature heat seal performance and is highly rigid.

0006Other disadvantageous characteristics of a propylenic polymer include a high glass transition temperature Tg (about 0 °C), due to which the impact resistance at a low temperature (e.g. -30 °C) is problematically poor.

0007Recently, an olefin polymer produced by using a metallocene catalyst was also proposed, but a metallocene catalyst has a limited active center, which results in a narrow molecular weight distribution of a polymer obtained, which is suitable to a precise injection molding or an ordinary injection molding and can preferably be employed to mold a fiber, but is not always satisfactory when applied to a heat molding, an extrusion, a blow molding or a molding of a foam or a film. An LLDPE (linear low density polyethylene) obtained using a metallocene also involves the problems of poor transparency and surface condition, although it has a pliability.

0008Transition metal compounds are described in <patcit id="pcit0001" dnum="EP0818458A1"><text>EP A1 0 818 458</text></patcit>. The compounds are used for the preparation of olefinic polymers. Typical transition metal compounds according to the document are (1,2'-ethylene)(2,1'-ethylene)-bis(indenyl)zirconium dichloride and (1,2'-ethylene)(2,1'-ethylene)-bis(3-methylindenyl)zirconium dichloride.

Disclosure of the invention

0009The objective of the invention is to provide a transition metal compound, a polymerization catalyst and a method for production which are employed preferably in a polymerization of olefinic resins .

0010We made an effort and discovered that various parameters such as an isotactic pentad fraction (mmmm), molecular distribution, intrinsic viscosity [η] are related closely to various properties of a propylenic polymer, and finally established the invention. <ol id="ol0001" compact="compact"><li>1. A compound of a transition metal Group 3 to Group 10 or of lanthanoids in the periodic table represented by Formula (VIII) <chemistry id="chem0001" num="0001"><img file="EP1772467B1_D0001.tif" /></chemistry> wherein each of A³ and A⁴ denotes a crosslinking represented by the formula (IX) <chemistry id="chem0002" num="0002"><img file="EP1772467B1_D0002.tif" /></chemistry> wherein E denotes C, Si, Ge or Sn and each of R³¹ and R³² denotes a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, and each may be same to or different from each other, or both may be taken together to form a ring; X⁴ denotes a σ-binding or π-binding ligand, and when two or more X⁴ are present they may be same or different, Y⁵ is a Lewis base and when two or more Y⁵ are present they may be same or different, and each Y⁵ may be crosslinked with other Y⁵ or X⁴, q is an integer of 1 to 5 and represents [(valency of M³)-2 ]; r is an integer of 0 to 3; R²¹ and R²² each denotes a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group and a heteroatom-containing group; each of R²³ to R³⁰ denotes a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group and a heteroatom-containing group, and M³ denotes a metal element of Group 3 to Group 10 or of lanthanoids in the periodic table.</li><li>2. An olefin-polymerizing catalyst obtained by bringing (A) a transition metal element of Group 3 to Group 10 or of lanthanoids in the periodic table of above 1 into contact with (B) a compound capable of forming an ionic complex by reacting with a transition metal compound as a component (A).</li><li>3. An olefin-polymerizing catalyst obtained by bringing (A) a transition metal element of Group 3 to Group 10 or of lanthanoids in the periodic table of above 1 into contact with (B) a compound capable of forming an ionic complex by reacting with a transition metal compound as a component (A) and with (C) an organic aluminium compound.</li><li>4. A method for producing an olefinic polymer <b>characterized in that</b> an olefin is polymerized in the presence of an olefin-polymerizing catalyst of above 2 or 3.</li><li>5. The method for producing an olefinic polymer of above 4 wherein the organic aluminum compound is a trialkyl aluminum.</li><li>6. The method for producing an olefinic polymer of above 4 or 5 wherein the olefin is propylene.</li></ol>

Best mode for carrying out the invention.

0011The embodiments of the invention are detailed below.

0012The invention relates to a novel transition metal compound having a double crosslinking ligand useful as an olefin polymerization catalyst, an olefin polymerization catalyst comprising a compound capable of forming an ionic complex by reacting said transition metal compound and a method for producing an olefinic polymer. An inventive transition metal compound [I], an olefin polymerization catalyst [II] comprising a compound capable of forming an ionic complex by reacting said transition metal compound, and a method for producing an olefinic polymer [III] are detailed below.

[I] Transition metal compound

0013An inventive transition metal compound is a double crosslinking compound of a transition metal of Group 3 to Group 10 or of lanthanoids in the periodic table, which has the structure represented by Formula (VIII): <chemistry id="chem0003" num="0003"><img file="EP1772467B1_D0003.tif" /></chemistry> wherein each of A³ and A⁴ denotes a crosslinking consisting of Group XIV metal (C, Si, Ge, Sn) and may be same to or different from each other, X⁴ denotes a σ-binding or π-binding ligand, and when two or more X⁴ are present they may be same or different, Y⁵ is a Lewis base and when two or more Y⁵ are present they may be same or different, and each Y⁵ may be crosslinked with other Y⁵ or X⁴, q is an integer of 1 to 5 and represents [(valency of M3)-2], r is an integer of 0 to 3, each of R²¹ to R³⁰ denotes a halogen atom, a hydrocarbon group having 1 to 20 carbon atom(s), a silicon-containing group and a heteroatom-containing group, and M³ denotes a metal element of Group 3 to Group 10 or of lanthanoids in the periodic table.

0014In Formula (VIII) shown above, each of A³ and A⁴ forms a crosslinking group consisting of Group IVX element (C, Si, Gen) and may be same to or different from each other. A³ and A⁴ each denote a crosslinking group represented by Formula (VIV): <chemistry id="chem0004" num="0004"><img file="EP1772467B1_D0004.tif" /></chemistry> wherein E denotes C, Si, Ge, Sn, each of R³¹ and R³² denotes a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atom (s) or a halogen-containing hydrocarbon group having 1 to 20 carbon atom(s), and each may be same to or different from each other, or the both may be taken together to form a ring.

0015A halogen atom in Formula (VIV) may for example be a chlorine, fluorine, bromine or iodine atom. Examples of a hydrocarbon group having 1 to 20 carbon atom(s) are an alkyl group such as methyl, ethyl, propyl, butyl, hexyl, cyclohexyl, octyl groups and the like, an alkenyl group such as vinyl, propenyl, cyclohexenyl groups and the like; an arylalkyl group such as benzyl, phenylethyl, phenylpropyl groups and the like; and an aryl group such as phenyl, tolyl, dimethylphenyl, trimethylphenyl, ethylphenyl, propylphenyl, biphenyl, naphthyl, methylnaphthyl, anthracenyl, phenanthryl groups and the like. Among those listed above, an alkyl group such as methyl, ethyl, propyl groups and the like and an aryl group such as phenyl group are preferred. A halogenated hydrocarbon having 1 to 20 carbon atom(s) may for example be one of the hydrocarbon groups listed above which is substituted with a halogen atom. Among these; those preferred are a halogenated alkyl group such as trifluoromethyl, trichloromethyl groups and the like.

0016A crosslinking group consisting of a carbon atom in Formula (VIV) may for example be methylene, dimethylmethylene group; an alkylidene group such as ethylidene, propylidene, isopropylidene, cyclohexylidene and the like; as well as 1,1-cyclohexylene and vinylidene groups. A crosslinking group consisting of a silicon atom may for example be an alkylsilylene group such as methylsilylene, dimethylsilylene, diethylsilylene, di(n-propyl)silylene, di(i-propyl)silylene, di(cyclohexyl)silylene and the like; an alkylarylsilylene group methylphenylsilylene, ethylphenylsilylene and the like; and arylsilylene group such as diphenylsilylene, di(p-tolyl)silylene, di(p-chlorophenyl)silylene and the like. A crosslinking group consisting of a germanium atom may for example be a germylene group obtained by replacing a silicon atom in a crosslinking group consisting of a silicon atom listed above with a germanium atom. A crosslinking group consisting of a tin atom may for example be a stannylene group obtained by replacing a silicon atom in a crosslinking group consisting of a silicon atom listed above with a tin atom. One preferred as A³ or A⁴ is a crosslinking group consisting of a carbon atom or a crosslinking group consisting of a silicon atom.

0017X⁴ is a σ-binding or π-binding ligand, and such σ-binding ligand may for example be a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxygroup having 6 to 20 carbon atoms, an amide group having 1 to 20 carbon atoms, a silicon-containing group having 1 to 20 carbon atoms, a phosphide group having 1 to 20 carbon atoms, a sulfide group having 1 to 20 carbon atoms, a sulfoxide group having 1 to 20 carbon atoms and an acyl group having 1 to 20 carbon atoms, among which a halogen atom and a hydrocarbon group having 1 to 20 carbon atoms are preferred. A halogen atom and a hydrocarbon group having 1 to 20 carbon atoms may be those described above. An alkoxy group having 1 to 20 carbon atoms may for example be an alkoxy group such as methoxy, ethoxy, propoxy, butoxy groups and the like; and an aryloxy group such as phenoxy, methyphenoxy, dimethylphenoxy, naphthoxy groups and the like. An aryloxy group having 6 to 20 carbon atoms may for example be phenylmethoxy, phenylethoxy groups and the like. An amide group having 1 to 20 carbon atoms may for example be an alkylamide group such as dimethylamide, diethylamide, dipropylamide, dibutylamide, dicyclohexylamide, methylethylamide groups and the like, an alkenylamide group such as divinylamide, dipropenylamide, dicyclohexenylamide groups and the like; an arylalkylamide group such as dibenzylamide, phenylethylamide, phenylpropylamide groups and the like; and arylamide group such as diphenylamide, dinaphtylamide groups and the like. A silicon-containing group having 1 to 20 carbon atoms may for example be a monohydrocarbon-substituted silyl group such as methylsilyl, phenylsilyl groups and the like; a dihydrocarbon-substituted silyl group such as dimethylsilyl, diphenylsilyl groups and the like; a trihydrocarbon-substituted silyl group such as trimethylsilyl, triethylsilyl, tripropylsilyl, tricyclohexylsilyl, triphenylsilyl, dimethylphenylsilyl, methylphenyldisilyl, tritolylsilyl, trinaphthylsilyl groups and the like; a silyl ether group of a hydrocarbon-substituted silyl group such as trimethylsilylether group; a silicon-substituted alkyl group such as trimethylsilylmethyl group; and a silicon-substituted aryl group such as trimethylsilylphenyl group and the like. Among those listed above, trimethylsilyl, phenethyldimethylsilyl groups are preferred. A sulfide group having 1 to 20 carbon atoms may for example be an alkylsulfide group such as methylsulfide, ethylsulfide, propylsulfide, butylsulfide, hexylsulfide, cyclohexylsulfide, octylsulfide groups and the like and an alkenylsulfide group such as vinylsulfide, propenyl sulfide, cyclohexenylsulfide groups and the like; an arylalkylsulfide group such as benzylsulfide, phenylethylsulfide, phenylpropylsulfide groups and the like; and an arylsulfide group such as phenylsulfide, tolylsulfide, dimethylsulfide, trimethylphenylsulfide, ethylphenylsulfide, propylphenylsulfide, biphenylsulfide, naphthylsulfide, methylnaphthylsulfide, anthracenylsulfide, phenanthrylsulfide groups and the like. A sulfoxide group having 1 to 20 carbon atoms may for example be an alkylsulfoxide group such as methylsulfoxide, ethylsulfoxide, propylsulfoxide, butylsulfoxide, hexylsulfoxide, cyclohexylsulfoxide, octylsulfoxide groups and the like and an alkenylsulfoxide group such as vinylsulfoxide, propenylsulfoxide, cyclohexenylsulfoxide groups and the like; an arylalkylsulfoxide group such as benzyl sulfoxide, phenylethylsulfoxide, phenylpropylsulfoxide groups and the like; and an arylsulfoxide such as phenylsulfoxide, tolylsulfoxide, dimethylphenylsulfoxide, trimethylphenylsulfoxide, ethylphenylsulfoxide, propylphenylsulfoxide, biphenylsulfoxide, naphthylsulfoxide, methylnaphthylsulfoxide, anthracenylsulfoxide, phenanthrylsulfoxide groups and the like. An acyl group having 1 to 20 carbon atoms may for example be an alkylacyl group such as formyl, acetyl, propionyl, butyryl, valeryl, palmitoyl, thearoyl, oleoyl groups and the like; an arylacyl group such as benzoyl, toluoyl, salicyloyl, cinnamoyl, naphthoyl, phthaloyl groups and the like; oxalyl, malonyl and succinyl groups derived from dicarboxylic acids such as oxalic acid, malonic acid and succinic acid, respectively, and the like.

0018A π-binding ligand may for example be a conjugated diene bond-carrying compound having 4 to 20 carbon atoms, a non-conjugated diene bond-carrying compound having 5 to 20 carbon atoms and the like. A conjugated diene bond-carrying compound having 4 to 20 carbon atoms may for example be 1,3-butadiisoprene, chloroprene, 1,3-pentadiene, 1,3-hexadiene, 1,3,5-hexatriene, 1,3-heptadiene, 1,3,6-heptatriene, 1,4-diphenylbutadiene and the like. A non-conjugated diene bond-carrying compound having 5 to 20 carbon atoms may for example be 1,4-pentadiene, 1,4-hexadiene and the like.

0019Characteristically, a σ-binding ligand in X⁴ gives an enhanced reactivity with M³. On the other hand, a π-binding ligand gives an increased activity.

0020Y⁵ is a Lewis base and when two or more Y5 are present they may be same or different. Each Y5 may be crosslinked with other Y⁵ or X⁴. Y⁵ may optionally be crosslinked with a cyclopentadienyl ring in Formula (VIII). Examples of Y⁵ are amines, ethers, phosphines, thioethers and the like. Amines may for example be an amine having 1 to 20 carbon atoms, and typically an alkylamine such as methylamine, ethylamine, propylamine, butylamine, cyclohexylamine, methylethylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dicyclohexylamine, methylethylamine and the like and an alkenylamine such as vinylamine, propenylamine, cyclohexenylamine, divinylamine, dipropenylamine, dicyclohexenylamine and the like; an arylalkylamine such as phenylamine, phenylethylamine, phenylpropylamine and the like; and arylamine such as diphenylamine, dinaphthylamine and the like. Ethers may for example be an aliphatic monoether compound such as methylether, ethylether, propylether, isopropylether; butylether, isobutylether, n-amylether, isoamylether and the like; an aliphatic mixed ether compound such as methylethylether, methylpropylether, methylisopropylether, methyl-n-amylether, methylisoamylether, ethylpropylether, ethylisopropylether, ethylbutylether, ethylisobutylether, ethyl-n-amylether, ethylisoamylether and the like; an aliphatic unsaturated ether compound such as vinylether, allylether, methylvinylether, methylallylether, ethylvinylether, ethylallylether and the like; an aromatic ether compound such as anisol, phenethol, phenylether, benzylether, phenylbenzylether, α-naphthylether, β-naphthylether and the like, as well as a cyclic ether compound such as ethylene oxide, propylene oxide, trimethylene oxide, tetrahydrofuran, tetrahydropyrane, dioxane and the like. An example of the phosphines may be a phosphine having 1 to 20 carbon atoms. Those included typically are an alkylphosphine including a monohydrocarbon-substituted phosphine such as methylphosphine, ethylphosphine, propylphosphine, butylphosphine, hexylphosphine, cyclohexylphosphine, octylphosphine and the like; a dihydrocarbon-substituted phosphine such as dimethylphosphine, diethylphosphine, dipropylphosphine, dibutylphosphine, dihexylphosphine, dicyclohexylphosphine, dioctylphosphine and the like; a trihydrocarbon-substituted phosphine such as dimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, trihexylphosphine, tricyclohexylphosphine, trioctylphosphine and the like and a monoalkenylphosphine such as vinylphosphine, propenylphosphine, cyclohexenylphosphine and the like as well as a dialkenyl phosphine whose hydrogen atoms on the phosphorus were replaced with two alkenyl groups; a trialkenyl phosphine whose hydrogen atoms on the phosphorus were replaced with three alkenyl groups; an arylalkylphosphine such as benzylphosphine, phenylethylphosphine, phenylpropylphosphine and the like; a diarylalkyl phosphine or an aryldialkylphosphine whose hydrogen atoms on the phosphorus were replaced with three aryl or alkenyl groups; phenylphosphine, tolylphosphine, dimethylphenylphosphine, trimethylphenylphosphine, ethylphenylphosphine, propylphenylphosphine, biphenylphosphine, naphthylphosphine, methylnaphthylphosphine, anthracenylphosphine, phenanthracenyl phosphine; a di(alkylaryl)phosphine whose hydrogen atoms on the phosphorus were replaced with 2 aklkylaryl groups; a tri(alkylaryl)phosphine whose hydrogen atoms on the phosphorus were replaced with 3 alkylaryl groups, and the like. An example of the thioethers may be a sulfide mentioned above.

0021Each of R²¹ to R³⁰ denotes a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group and a heteroatom-containing group, and a halogen atom may for example be chlorine, fluorine, bromine, iodine atoms. A hydrocarbon group having 1 to 20 carbon atoms may for example be an alkyl group such as methyl, ethyl, propyl, butyl, hexyl, cyclohexyl, octyl groups and the like and an aryl group such as phenyl, naphthyl groups and the like; an arylalkyl group such as benzyl, phenylethyl, phenylpropyl groups and the like; an alkylaryl group such as tolyl, xylyl groups and the like. A silicon-containing group may for example be a silicon-containing group having 1 to 20 carbon atoms, typical examples of which are trimethylsilyl, trimethylsilylmethyl, triphenylsilyl groups and the like. A heteroatom-containing group may for example be a heteroatom-containing group having 1 to 20 carbon atoms, typical examples of which are a nitrogen-containing group such as dimethylamino, diethylamino, diphenylamino groups and the like, a sulfur-containing group such as phenylsulfide, methylsulfide groups and the like; a phosphorus-containing group such as dimethylphosphino, diphenylphosphino groups and the like; an oxygen-containing group such as methoxy, ethoxy, phenoxy groups and the like. Those employed preferably as R²¹ to R³⁰ are a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

0022M3 denotes a metal element of Group 3 to Group 10 or of lanthanoids in the periodic table, and is typically titanium, zirconium, hafnium, vanadium, chromium, manganese, nickel, cobalt, palladium and lanthanoid metals. A metal element of Group IV in the periodic table is preferable as M³ since it gives a higher activity.

0023A preferred representative of a transition metal compound represented by Formula (VIII) shown above is one wherein A³ and A⁴ denotes a crosslinking group consisting of a carbon atom or a silicon atom which may be same to or different from each other; X⁴ denotes a σ-binding or π-binding ligand, and when two or more X⁴ are present they may be same or different; Y⁵ is a Lewis base and when two or more Y⁵ are present they may be same or different; each Y⁵ may be crosslinked with other Y⁵ or X⁴; q is an integer of 1 to 5 and represents [(valency of M³)-2], r is an integer of 0 to 3, each of R²¹ to R³⁰ denotes a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms; and M³ denotes a metal element of Group IV in the periodic table. A transition metal compound represented by Formula (VIII) shown above, when those of Group IV in the periodic table are exemplified, includes (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)bis(indenyl)zirconium dichloride,, (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)bis(3-methylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)bis(3-ethylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)bis(3-isopropylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)bis(3-trimethylsilylmethylindenyl)zirconium dichloride,, (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)bis(3-butylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)bis(4-methylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)bis(4,7-dimethylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)bis(5,6-dimethylindenyl)zirconium dichloride, (1,2'-phenylmethylsilylene)(2,1'-phenylmethylsilylene)bis(indenyl)zirconium dichloride,, (1,2'-phenylmethylsilylene)(2,1'-phenylmethylsilylene)bis(3-methylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-isopropylidene)bis (indenyl) zirconium dichloride,, (1,2'-dimethylsilylene)(2,1'-isopropylidene)bis(3-methylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-isopropylidene)bis(3-isopropylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-isopropylidene)bis(3-n-butylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-isopropylidene)bis(3-trimethylsilylmethylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,11-isopropylidene)bis(3-trimethylsilylindenyl)zinconium dichloride, (1,2'-dimethylsilylene)(2,1'-isopropylidene)bis(3-phenylindenyl) zirconium dichloride, (1,2'- dimethylsilylene)(2,1'-methylene)bis(indenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-methylene)bis(3-methylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-methylene)bis(3-isopropylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-methylene)bis(3-n-butylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-methylene)bis(3-trimethylsilylmethylindenyl)zirconium dichloride, (1,2'-dimethylsilylene)(2,1'-methylene)bis(3-trimethylsilylindenyl)zirconium dichloride, (1,2'-diphenylsilylene) (2,1'-methylene)bis(indenyl)zirconium dichloride, (1,2'-diphenylsilylene) (2,1'-methylene)bis(3-methylindenyl)zirconium dichloride, (1,2'-diphenylsilylene)(2,1'-methylene)bis(3-n-butylindenyl)zirconium dichloride, (1,2'-diphenylsilylene)(2,1'-methylene)bis(3-trimethylsilylmethylindenyl)zirconium dichloride, (1,2'-diphenylsilylene)(2,1'-methylene)bis(3-trimethylsilylindenyl)zirconium dichloride as well as the compounds obtained by replacing zirconium in the compounds listed above with titanium or hafnium, while they are not limiting. An analogous compound of a metal element of Groups other than Group IV or of lanthanoids. Preferably, a compound of a transition metal of Group IV in the periodic table, especially of zirconium is employed.

[II] Olefin polymerization catalyst

0024An inventive olefin polymerization catalyst consists of (A) a transition metal element of Group 3 to Group 10 or of lanthanoids in the periodic table represented by Formula (VIII) and (B) a compound capable of forming an ionic complex by reacting with a transition metal compound as a component (A), optionally with (C) an organic aluminium compound.

0025In an inventive polymerization catalyst, a component (A) and a compound capable of forming an ionic complex by reacting with a transition metal compound as a component (A).

0026One exemplified preferably as a component (B) is (B-1) an ionic compound capable of forming an ionic complex by reacting with a transition metal compound as a component (A), (B-2) an aluminoxane, or (B-3) a Lewis acid, because of its high polymerization activity and low catalyst cost.

0027A component (B-1) described above may be any ionic compound capable of forming an ionic complex by reacting with a transition metal compound as a component (A), and may for example be one exemplified as a component (B-1) in the first invention.

0028An ionic compound, which is a component (B-1), capable of forming an ionic complex by reacting with a transition metal compound as a component (A) may be employed alone or in a combination with one or more.

0029An aluminoxane as a component (B-2) may be any substance such as those described in the first invention as a component (B-2). Such aluminoxane may be employed alone or in a combination with one or more.

0030A Lewis acid as a component (B-3) is not particularly limited, and may be an organic compound or a solid inorganic compound. An organic compound employed preferably is a boron compound, an aluminium compound and the like, while an inorganic compound employed preferably is a magnesium compound, an aluminium compound and the like, because of their ability of forming an active center efficiently. Such aluminium compound may for example be bis(2,6-di-t-butyl-4-methylphenoxy)aluminium methyl, (1,1-bi-2-naphthoxy)aluminium methyl and the like, while a magnesium compound may for example be magnesium chloride, diethoxymagnesium and the like, and an aluminium compound may for example be aluminium oxide, aluminium chloride and the like, and a boron compound may for example be triphenylboron, tris(pentafluorophenyl)boron, tris[3,5-bis(trifluoromethyl)phenyl]boron, tris[(4-fluoromethyl)phenyl]boron, trimethylboron, triethylboron, tri-n-butylboron, tris(fluoromethyl)boron, tris(pentafluoroethyl)boron, tris(nonafluorobutyl)boron, tris(2,4,6-trifluorophenyl)boron, tris(3,5-difluoro)boron, tris[3,5-bis(trifluoromethyl)phenyl]boron, bis(pentafluorophenyl)fluoroboron, diphenylfluoroboron, bis(pentafluorophenyl)chloroboron, dimethylfluoroboron, diethylfluoroboron, di-n-butylfluoroboron, pentafluorophenyldifluoroboron, phenyldifluoroboron, pentafluorophenyldichloroboron, methyldifluoroboron, ethyldifluoroboron, n-butyldifluoroboron and the like.

0031Such Lewis acid may be employed alone or in a combination with one or more.

0032The molar ratio of a catalyst component (A) to a catalyst component (B) when employing a compound (B-1) as a catalyst component (B) is preferably 10:1 to 1:100, more preferably 2:1 to 1:10, and a ratio departing from this range is not advantageous industrially because of an increased catalyst cost per unit weight of a polymer. When a compound (B-2) is employed, the molar ratio is preferably 1:1 to 1:1000000, more preferably 1:10 to 1:10000. A ratio departing from this range is not advantageous industrially because of an increased catalyst cost per unit weight of a polymer.

0033The molar ratio of a catalyst component (A) to a catalyst component (B-3) is preferably 10:1 to 1:2000, more preferably 5:1 to 1:1000, particularly 2:1 to 1: 500, and a ratio departing from this range is not advantageous industrially because of an increased catalyst cost per unit weight of a polymer. As a component (B), any one of, or, a combination of two or more of components (B-1), (B-2) and (B-3) may be employed.

0034A polymerization catalyst according to the invention may comprise as main components a component (A) and a component (B) described above, or may comprise as main components a component (A), a component (B) and an organic aluminium compound (C).

0035As an organic aluminum compound as a component C may be a compound represented by Formula (VII):         R¹⁵_VALJ_3-V     (VII) Wherein R15 denotes an alkyl group having 1 to 10 carbon atoms, J denotes a hydrogen atom, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a halogen atom, and v is an integer of 1 to 3.

0036Examples of a compound represented by Formula (VII) shown above are trimethylaluminium, triethylaluminium, triisopropylaluminium, triisobutylaluminium, dimethylaluminium chloride, diethylaluminium chloride, methylaluminium dichloride, ethylaluminium dichloride, dimethylaluminium fluoride, diisobutylaluminium hydride, diethylaluminium hydride, ethylaluminium sesquichloride and the like. Among those listed above, trimethylaluminium, triethylaluminium and triisobutylaluminium are preferred, and triisobutylaluminium is more preferred.

0037Only one organic aluminum compound listed above may be employed or a combination of two or more such compound may be employed.

0038The molar ratio of a catalyst component (A) to a catalyst component (C) is preferably 1:1 to 1:10000, more preferably 1:5 to 1:2000, particularly 1:10 to 1:1000. By employing a catalyst component (C), the polymerization activity per unit weight of a transition metal can be increased, but a too excessive amount, especially one departing from the range specified above, is of no use, and results in a large amount of residue remaining in a polymer, while a too small amount may fail to obtain a sufficient catalyst activity.

0039Upon contact or after contact between components in this invention, a polymer such as polyethylene, polypropylene and the like, or an inorganic oxide such as silica, alumina and the like, is allowed to exist simultaneously or to be in contact. A support on a carrier may be effected preferably as a support on a polymer, and such polymeric carrier has a particle size of 1 to 300 µm, preferably 10 to 200 µm, more preferably 20 to 100 µm. A particle size smaller than 1 µm results in increased microparticles in a polymer, while one exceeding 300 µm results in increased coarse particles in a polymer, which leads to a problematic reduction in the bulk density and a plugging of a hopper in a manufacturing process. The specific surface area of a carrier when employed as discussed above is 1 to 1,000 m²/g, preferably 50 to 500 m²/gm, and a micropore void volume is 0.1 to 5 m³/g, preferably 0.3 to 3 m³/g.

0040A contact may be effected in an atmosphere of an inert gas such as nitrogen, and in a hydrocarbon such as pentane, hexane, heptane, toluene, xylene and the like. While an addition or a contact of each component may of course be effected at a polymerization temperature, a temperature of -30 °C to a boiling point of a solvent, especially room temperature to a boiling point of a solvent is preferred.

[III] Method for producing olefin polymer

0041An inventive method for producing an olefin polymer is a method for producing a polymer wherein

0042An olefin is homopolymerized or copolymerized in the presence of an olefin-polymerizing catalyst obtained by bringing (A) a transition metal element of Group 3 to Group 10 or of lanthanoids in the periodic table represented by Formula (VIII) into contact with (B) a compound capable of forming an ionic complex by reacting with a transition metal compound as a component (A) optionally together with (C) an organic aluminium compound. As an organic aluminium compound (C), a compound represented by Formula (VII) shown above is employed, and is preferably a trialkylaluminium compound. Those particularly preferred are trimethylaluminium and triisobutylaluminium. In an inventive method for producing an olefin polymer, an organic aluminium compound (C) may be employed as being brought into contact preliminarily with a component (A) and/or a component (B), or may be introduced first into a reactor and then brought into contact with a component (A) and a component (B). The amount of a component (C) employed is similar to that described above in the section of the olefin polymerization catalyst. According to an inventive method for producing an olefin polymer, a polymerization catalyst described above is used preferably to effect a homopolymerization of an olefin or a copolymerization of an olefin with other olefins and/or other monomers (a copolymerization between different olefins, a copolymerization between olefins and other monomers, or a copolymerization between different olefins together with other monomers).

0043While such olefin is not particularly limited, an α-olefin having 2 to 20 carbon atoms is preferred. Such α-olefin may for example be α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 4-phenyl-1-butene, 6-phenyl-1-hexene, 3-methyl-1-butene, 4-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-hexene, 5-methyl-1-hexene, 3,4-dimethyl-1-pentene, 3,4-dimethyl-1-pentene, 4,4-dimethyl-1-pentene, vinylcyclohexane and the like, diens such as 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, and the like, a halogenated α-olefin such as hexafluoropropene, tetrafluoroethylene, 2-fluoropropene, fluoroethylene, 1,1-difluoroethylene, 3-fluoropropene, trifluoroethylene, 3,4-dichloro-1-butene and the like, cyclic olefins such as cyclopentene, cyclohexene, norbornene, 5-methylnorbornene, 5-ethylnorbornene, 5-propylnorbornene, 5,6-dimethylnorbornene, 5-benzylnorbornene and the like, styrenic substances including alkylstyrenes such as styrene, p-methylstyrene, p-ethylstyrene, p-propylstyrene, p-isopropylstyrene, p-butylstyrene, p-tert-butylstyrene, p-phenylstyrene, o-methylstyrene, o-ethylstyrene, o-propylstyrene, o-isopropylstyrene, m-methylstyrene, m-ethylstyrene, m-isopropylstyrene, m-butylstyrene, mesitylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,5-dimethylstyrene and the like, alkoxystyrenes such as p-methoxystyrene, o-methoxystyrene, m-methoxystyrene and the like, halogenated styrenes such as p-chlorostyrene, m-chlorostyrene, o-chlorostyrene, p-bromostyrene, m-bromostyrene, o-bromostyrene, p-fluorostyrene, m-fluorostyrene, o-fluorostyrene, o-methyl-p-fluorostyrene and the like, as well as trimethylsilylstyrene, vinyl benzoate, divinylbenzene and the like. Other olefins described above may appropriately be selected from the olefins listed above.

0044In this invention, any one of, or a combination of two or more of the olefins listed above may be employed. When two or more olefins are copolymerized, any combination of the olefins listed above may be employed.

0045Also in this invention, the olefins listed above may be copolymerized with other monomers, and such monomers are linear diolefins such as butadiene, isoprene, 1,4-pentadiene, 1,5-hexadiene and the like, polycyclic olefins such as norbornene, 1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-norbornene and the like, cyclic olefins such as norbornadiene, 5-ethylidenenorbornene, 5-vinylnorbornene, dicyclopentadiene and the like, unsaturated esters such as ethyl acrylate, methyl methacrylate and the like.

0046In this invention, one preferred particularly as such olefin is propylene.

0047A method for polymerizing olefins is not particularly limited, and may be a slurry polymerization, a solution polymerization, a vapor phase polymerization, a bulk polymerization, a suspension polymerization.

0048When a polymerization solvent is employed, such solvent may for example be a hydrocarbon and a halogenated hydrocarbon such as benzene, toluene, xylene, n-hexane, n-heptane, cyclohexane, methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene and the like. Any one of, or a combination of two or more of those listed above may be employed. A certain monomer subjected to a polymerization may be used also as a solvent.

0049The amount of a catalyst employed in a polymerization reaction is selected so that a component [A] is within the range usually of 0.5 to 100 micromoles, preferably 2 to 25 micromoles per 1 liter of a solvent, for the purpose of advantageous polymerization activity and reactor efficiency.

0050A polymerization condition involves a polymerization pressure usually of atmospheric pressure to 2000 kg/cm²G. The reaction temperature is usually -50 to 250 °C. The molecular weight of a polymer may be adjusted by appropriately selecting the types and amounts of respective catalyst components, and the polymerization temperature, or by introducing hydrogen.

0051Also in a polymerization process of an olefin according to the invention, a catalyst described above is used to effect a preliminary polymerization. Such preliminary polymerization can be effected by bringing a solid catalyst component into contact with a small amount of an olefin, at a reaction temperature of -20 to 100 °C, preferably -10 to 70 °C, particularly 0 to 50 °C. While an inert hydrocarbon, an aliphatic hydrocarbon, an aromatic hydrocarbon or a monomer is employed as a solvent for this preliminary polymerization, an aliphatic hydrocarbon is particularly preferred. This preliminary polymerization may be effected also in the absence of a solvent. In a preferably adjusted condition, a preliminary polymerization product has an intrinsic viscosity [η] (at 135 °C in decalin) of 0.2 dl/g, preferably 0.5 dl/g, and an amount of a preliminary polymerization product per 1 millimole of a transition metal component in a catalyst is 1 to 10,000 g, preferably 10 to 1,000 g.

0052The present invention is further described in the following the examples which is not intended to restrict the invention.

0053The present invention is discussed specifically in the following examples.

(Production example 1) Synthesis of (dimethylsilylene) 2 (indene) 2

0054Under nitrogen flow, a 1L three-necked flask receives 50 mL of THF and 2.5 g (41 mmol) of Mg. To this 0.1 mL of 1,2-dibromoethane is added and the mixture is stirred to activate Mg. After stirring for 30 minutes, the solvent is removed and 50 mL of THF is newly added. To this, a solution of 5.0 g (25.6 mmol) of 2-bromoindene in THF (200 mL) is added dropwise over 2 hours. After completion of the addition followed by stirring at room temperature for 2 hours followed by cooling to -78°C, a solution of 3.1 mL (25.6 mmol) of dichlorodimethylsilane in THF (100 mL) is added dropwise over 1 hour. After stirring for 15 hours, the solvent is evaporated off. The residue was extracted with 200 mL of hexane and the solvent was distilled off to obtain 6.6 g (24.2 mmol) of 2-chloromethylsilylindene (yield: 94%).

0055Under nitrogen flow, a 1L three-necked flask receives 400 mL of THF and 8 g of 2-chloromethylsilylindene and the mixture is cooled to -78°C. To this, 38.5 mL (38.5 mmol) of a solution (1.0M) of LiN(trimethylsilylene)2 in THF is added dropwise. After stirring at room temperature for 15 hours, the solvent is distilled off and the residue is extracted with 300 mL of hexane. The solvent was distilled off to obtain 2.2 g (6.4 mmol) of (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)(indene) 2 (yield:33.4 %). The results of ¹H-NMR analysis (90MHz, CDCl3) are as follows: δ-0.69, 0.73 (12H, dimethylsilylene), 3.66 (4H, -CH2-), 7.17 (8H, Ar-H).

[Example 1] Synthesis of (dimethylsilylene) 2 (indenyl) 2 zirconium dichloride

0056A Schlenk's bottle receives 22.2 g (6.4 mmol) of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene)(indene) 2 obtained above and 10 mL of ether. After cooling to -78°C and adding 9.6 mL (15.4 mmol) of n-BuLi (1.6 M solution in hexane), the mixture is stirred for 12 hours at room temperature. The solvent is distilled off to obtain a solid which is washed with 20 mL of hexane to obtain a lithium salt quantitatively. This lithium salt is dissolved in 100 mL of toluene. A separate Schlenk's bottle receives 1.5 g (6.4 mmol) of zirconium tetrachloride and 100 mL of toluene. A 500 mL three-necked flask receives 100 mL of toluene, which is cooled to 0°C. To this, the lithium salt and zirconium tetrachloride in equal amounts are added dropwise using a cannula over 1 hour. After completion of the addition, the mixture is stirred at room temperature overnight. The solution is filtered, and the solvent in the filtrate is distilled off. The solid thus obtained was recrystallized from dichloromethane to give 1.2 g (2.4 mmol) of (1,2'-dimethylsilylene)(indenyl)2 zirconium dichloride (yield: 37 %).

0057The results of ¹H-NMR analysis (90MHz, CDCl3) are as follows:δ 0.85, 1.08 (12H, dimethylsilylene), 7.18 (2H, -CH-), 7.2-7.4, 7.6-7.7 (8H, Ar-H).

[Example 2] Synthesis of (dimethylsilylene)2(3-methylindenyl)2 zirconium dichloride

0058A Schlenk's bottle receives 2.2 g (6.4 mmol) of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene)(indene)2 obtained above and 100 mL of ether. After cooling to -78°C and adding 9.6 mL (15.4 mmol) of n-BuLi (1.6 M solution in hexane), the mixture is stirred at room temperature for 12 hours. The solvent is distilled off to obtain a solid, which is washed with 20 mL of hexane to obtain a lithium salt quantitatively. This lithium salt is dissolved in 100 mL of THF and cooled to -78°C. 7.4 g (52.0 mmol) of methyl iodide is added dropwise slowly and the mixture is stirred at room temperature for 12 hours. After distilling the solvent off followed by extraction with 50 mL of hexane, the solvent is removed to obtain 4.5 g (12 mmol) of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene)(3-methylindene)2 (yield:94 %).

0059Subsequently, a Schlenk's bottle receives under nitrogen flow 2.0 g (5.4 mmol) of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (3-methylindene)2 obtained above and 100 mL of ether. After cooling to -78°C and adding 13. 5 mL (21.6 mmol) of n-BuLi (1. 6 M solution in hexane), the mixture is stirred at room temperature for 12 hours. The solvent is distilled off to obtain a solid which was washed with hexane to obtain 1.1 g (2.9 mmol) of a lithium salt. This lithium salt is dissolved under nitrogen flow in 100 mL of toluene. The mixture is cooled to -78°C and treated dropwise with a suspension of 0.7 g (3.0 mmol) of zirconium tetrachloride in toluene (100 mL) which has previously been cooled to -78°C. After completion of the addition, the mixture is stirred at room temperature for 6 hours. Thereafter, the mixture is filtered to obtain a filtrate, whose solvent is distilled off. Recrystallization from dichloromethane gave 0.5 g (0.94 mmol) of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (3-methylindenyl) 2 zirconium dichloride (yield:32 %). The results of 1H-NMR analysis (90MHz, CDCl3) are as follows: δ 0.90, 1.00 (12H, dimethylsilylene), 2.89 (6H, CH3), 7.2-7.7 (8H, Ar-H).

[Example 3] Synthesis of (dimethylsilylene) 2 )3-n-butylindenyl) 2 zirconium dichloride

0060A Schlenk's bottle receives 0.83 g (2.4 mmol) of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (indene)2 and 50 mL of ether. After cooling to -78°C and adding 3.1 mL (5.0 mmol) of n-BuLi (1.6 M solution in hexane), the mixture is stirred at room temperature for 12 hours. The solvent is distilled off to obtain a solid, which is washed with 20 mL of hexane to obtain 1.1 g (2.3 mmol) of a lithium salt as an ether adduct. This lithium salt is dissolved in 50 mL of THF and cooled to -78°C. 0.57 mL (5.3 mmol) of n-butylbromide is added dropwise slowly and the mixture is stirred at room temperature for 12 hours. After distilling the solvent off followed by extraction with 50 mL of hexane, the solvent was removed to obtain 0.81 g (1.77 mmol) of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (3-n-butylindene)2 (yield:74 %).

0061Subsequently, a Schlenk's bottle receives under nitrogen flow 0.81 g (1.77 mmol) of (1,2'-dimethylsilylene)(2,1'-dimethylsilylene)(3-n-butylindene)2 obtained above and 100 mL of ether. After cooling to -78°C and adding 2.7 mL (4.15 mmol) of n-BuLi (1.54 M solution in hexane), the mixture is stirred at room temperature for 12 hours. The solvent is distilled off to obtain a solid which was washed with hexane to obtain 0.28 g (1.43 mmol) of a lithium salt as an ether adduct.

0062The lithium salt obtained above is dissolved under nitrogen flow in 50 mL of toluene. The mixture is cooled to -78°C and treated dropwise with a suspension of 0.33 g (1.42 mmol) of zirconium tetrachloride in toluene (50 mL) which has previously been cooled to -78°C. After completion of the addition, the mixture is stirred at room temperature for 6 hours. Thereafter, the mixture is filtered to obtain a filtrate, whose solvent is distilled off. Recrystallization from dichloromethane gave 0.2 g (0.32 mmol) of (1,2'-dimethylsilylene)(2,1'-dimethylsilylene) (3-n-butylindenyl) 2 zirconium dichloride (yield:22 %).

0063The results of ¹H-NMR analysis (90MHz, CDCl3) are as follows: δ 0.88, 0.99 (12H, dimethylsilylene), 0.7-1.0, 1.1-1.5 (18H, n-Bu), 7.0-7.6 (8H, Ar-H).

[Example 4] Synthesis of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene)bis(indenyl) 2 zirconium (diphenylbutadiene)

00640.2 g (0.40 mmol) of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (indenyl) 2 zirconium dichloride and 0.09 g (0.42 mmol) of 1,4-diphenylbutadiene are combined with 20 mL of toluene. To this solution, 0.5 mL of n-BuLi (1.6 M solution in hexane) is added dropwise at -78°C. After completion of the addition, the solution is extracted with 50 mL of dichloromethane. The extract is concentrated to 10 mL, and cooled to 0°C whereby obtaining 0.1 g of the desired product as a dark red solid (yield: 40 %).

[Example 5]

0065A 1L autoclave, which had been dried by heating, was charged under nitrogen flow at room temperature with 400 mL of toluene and 3 mmol of a methyl aluminoxane. After heating to 60°C with stirring, 3 µmol of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (3-methylindenyl)2 zirconium dichloride obtained in Example 2 was added. Subsequently, the pressure was kept at 7 kg/cm² G with propylene to effect polymerization for 1 hour. After completion of the polymerization, the reaction product was poured into methanol-hydrochloric acid solution, stirred thoroughly and filtered, and then washed thoroughly with methanol, dried to obtain 35.0 g of an isotactic polypropylene. The polymer thus obtained had the melting point of 76.4°C, the intrinsic viscosity of 2.45 d1/g, the weight mean molecular weight Mw of 342,000, the molecular weight distribution Mw/Mn of 1.80 and the % meso-pentad [mmmm] of 40.7 %.

0066A % meso-pentad was determined as a % area occupied by the signal at 21.8 ppm assigned to the pentad-meso based on the total area of the 9 signals appearing within the range from 19 to 22 ppm in 13C-NMR of the polymer.

0067A melting point was determined using the following device under the following conditions. <ul id="ul0001" list-style="none" compact="compact"><li>Instrument: DSC of Perkin Elmer 7 Series</li><li>Temperature raising rate: 10°C/min</li><li>Temperature range: -50°C to 150°C</li></ul>

0068An intrinsic viscosity [η] was determined at 135°C in decalin.

0069A molecular weight and a molecular weight distribution were determined by a gel permeation chromatography (GPC) and represented as polystyrene. <ul id="ul0002" list-style="none" compact="compact"><li>Instrument: WATERS ALC/GPC150C</li><li>Column: TOSO, TSK HM + GMH6 x 2</li><li>Solvent: 1,2,4-trichlorobenzene</li><li>Flow rate: 1 mL/min</li></ul>

[Example 6]

0070A 1L autoclave, which had been dried by heating, was charged under nitrogen flow at room temperature with 400 mL of toluene, 0. 5 mmol of TIBA and 1 mmol of a methyl aluminoxane. After heating to 50°C with stirring, 1 µmol of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (3-n-butylindenyl)2 zirconium dichloride obtained in Example 3 was added. Subsequently, the pressure was kept at 7 kg/cm² with propylene to effect polymerization for 1 hour. After completion of the polymerization, the reaction product was poured into methanol-hydrochloric acid solution, stirred thoroughly and filtered, and then washed thoroughly with methanol, dried to obtain 19.5 g of an isotactic polypropylene. The polymer thus obtained had the melting point of 71.5°C, the intrinsic viscosity of 3.18 dl/g, the weight mean molecular weight Mw of 499,000, the molecular weight distribution Mw/Mn of 1.97 and the % meso-pentad [mmmm] of 44.5 %.

[Example 7]

0071The procedure similar to that in Example 6 was followed except for setting the polymerization temperature at 40°C to obtain 20.1 g of an isotactic polypropylene. The polymer thus obtained had the melting point of 69.9°C, the intrinsic viscosity of 6.05 dl/g, the weight mean molecular weight Mw of 914,000, the molecular weight distribution Mw/Mn of 1.95 and the % meso-pentad [mmmm] of 48.0 %.

[Example 8]

0072The procedure similar to that in Example 3 was followed except for using (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (indenyl)2 zirconium dichloride instead of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (3-methylindenyl)2 zirconium dichloride to obtain 30.0 g of an isotactic polypropylene. The polymer thus obtained had the melting point of 111.8°C, the intrinsic viscosity of 0. 83 dl/g, the weight mean molecular weight Mw of 90,000, the molecular weight distribution Mw/Mn of 1.74 and the % meso-pentad [mmmm] of 66.1 %.

[Comparative Example 1]

0073The procedure similar to that in Example 3 was followed except for using (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (tetrahydroindenyl)2 zirconium dichloride instead of (1,2'-dimethylsilylene)(2,1'-dimethylsilylene) (3-n-butylindenyl) 2 zirconium dichloride to obtain 15.6 g of an isotactic polypropylene. The polymer thus obtained had the melting point of 116.0°C, the intrinsic viscosity of 0.17 dl/g, the weight mean molecular weight Mw of 15,000, the molecular weight distribution Mw/Mn of 1.7 and the % meso-pentad [mmmm] of 75.7 %.

[Industrial applicability]

0074A propylenic polymer which has an excellent melt flowability, contains a less amount of stickiness-causing components, has a low modulus and is pliable, and is capable of providing a transparent molded article, thus being useful as a substitute for a pliable vinyl chloride resin and a composition thereof are prepared using transition metal compounds.