Production of olefin polymers
This application is a Continuation of application Ser. No. 07/727,857, filed on Jul. 10, 1991, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Art 
     The present invention relates to Ziegler polymerization of olefins. More particularly, the present invention is concerned with Ziegler polymerization of olefins, or α-olefins of at least 3 carbon atoms, in particular, characterized by, among others, the solid catalyst components comprising a transition metal in Ziegler catalysts and the polymerization temperature used which is no lower than 150° C. 
     Use of the solid catalyst component in accordance with the present invention in Ziegler catalysts as the transition metal component at the temperature will make it possible to produce polymers endowed with improved stereoregularity. 
     2. Background of the Invention 
     The catalysts heretofore proposed for the polymerization of olefins comprising a solid catalyst component containing titanium, magnesium and a halogen as the essential components and an organoaluminum compound (and an electron donor, if desired) have produced highly stereoregular polymers. 
     Such prior art catalysts are such that their catalyst activity may often be found at a polymerization temperature of 90° C. or lower, preferably 80° C. or lower. 
     It has been known in the art that ethylene polymerizes at such a higher temperature as 150° to 250° C. similarly at a temperature of 70° to 90° C. and that polymerization of ethylene at such a higher temperature is known to have such preferable characteristics that the polyethylenes produced have a narrower molecular weight distribution or copolymerizability of ethylene with another monomer is improved. 
     It has also been known in the art that propylene will not produce polymers endowed with acceptably high stereoregularity when it is polymerized at such a high temperature as 150° C. or higher. One possible reason therefor may be such that the solid structure comprising the titanium component capable of polymerizing propylene into polymers of high stereoregularity is destroyed at a temperature no lower than 150° C., the titanium component is aggromerated or excessively reduced by the organoaluminum component as a co-catalyst, or, when an electron donor is used during polymerization as what is called &#34;outside electron donor&#34;, it reacts so strongly with the titanium component or with the organoaluminum component at such a higher temperature that the catalyst activity is thus lowered. 
     Catalysts which are capable of producing highly stereoregular polymers at such a high temperature as no lower than 150° C. have, to the best of the present inventors, not been proposed. 
     SUMMARY OF THE INVENTION 
     The present invention is based on the discovery that the above problems can be solved by use of a specified solid catalyst component in Ziegler catalysts. 
     More particularly, the present invention presents a process for producing α-olefin polymers which comprises contacting at a temperature of 150° C. to 300° C. an olefin with a catalyst thereby to polymerize the olefin, the catalyst comprising: 
     Component (A) which is a solid catalyst component for Ziegler catalysts, which solid catalyst component is obtained by contacting the following Sub-components (i) to (iii): 
     Sub-component (i) which is a solid catalyst component for Ziegler catalysts comprising titanium, magnesium and a halogen as the essential components; 
     Sub-component (ii) which is a silicon compound represented by a formula 
     
         R.sup.1.sub.m X.sub.n Si(OR.sup.2).sub.4-m-n 
    
      wherein R 1  indicates a hydrocarbyl group of 1 to 20 carbon atoms, R 2  which may be the same as or different from R 1  indicates a hydrocarbyl group of 1 to 20 carbon atoms, X indicates a halogen atom, and m and n are each numbers satisfying equations 0≦m ≦3, 0≦n≦3 and 0≦(m+n)3; and 
     Sub-component (iii) which is an organometal compound of a metal of the Groups I to III of the Periodic Table; and 
     Component (B) which is an organoaluminum compound which is a mixture of the following Sub-component (B 1 ) and Sub-component (B 2 ): 
     Sub-component (B 1 ) which is an organoaluminum compound represented by a formula 
     
         R.sup.3.sub.3-a H.sub.a Al 
    
      wherein R 3  indicates a hydrocarbyl group of 6 to 20 carbon atoms and a is a number satisfying an equation 0≦a≦1; 
     Sub-component (B 2 ) which is an organoaluminum compound represented by a formula 
     
         R.sup.4.sub.3-b AlY.sub.b 
    
      wherein R 4  indicates a hydrocarbyl group of 1 to 20 carbon atoms, Y indicates a halogen atom, and b is a number satisfying an equation 0&lt;b&lt;3, 
     the mole ratio of Sub-component (B 2 ) to Sub-component (B 1 ) being 0.01 to 100, the mole ratio in Al/Ti of Component (B) to Component (A) being 0.1 to 1000. 
     It has now been possible in accordance with the present invention that highly stereoregular olefin polymers are produced at a temperature of 150° C. or higher where it would have not been possible to prepare such polymers in yield of a level comparable to that obtained by polymerization at a lower temperature of 80° C. or lower using known Ziegler catalysts. 
     The polymer produced by the present invention is characterized by the fact that they have broader molecular weight distribution than those produced at a lower polymerization temperature of 80° C. or lower. 
     DETAILED DESCRIPTION OF THE INVENTION 
     [I] Catalyst 
     The catalyst of the present invention comprises a combination of specific components (A) and (B). Here, the wording &#34;comprises&#34; means that the components are not limited only to those mentioned (namely, A and B), and includes co-presence of other components compatible with or suited for the purpose, such as an outside electron donor which is not essential but can be used if desired. 
     Component (A) 
     The Component (A) of the catalyst of the present invention is a solid catalyst component for Ziegler catalysts obtained by contacting the Sub-components (i) to (iii) shown below. The contact product of the Sub-components (i) to (iii) is washed amply with an inert hydrocarbon solvent to form the Component (A). Here, the wording &#34;obtained by contacting&#34; means that the components are not limited only to those mentioned, namely (i) to (iii), and includes co-presence of other components suited for the purpose. 
     Sub-component (i) 
     Sub-component (i) is a solid component comprising titanium, magnesium and a halogen as the essential components. Here, the wording &#34;comprising as the essential components&#34; indicates that it can also contain other elements suited for the purpose than the three components mentioned, that these elements can exist in any desired compound suited for the purpose respectively, and also that these elements can also exist in the form mutually bonded together. Solid components containing titanium, magnesium and a halogen are known per se. For example, those as disclosed in Japanese Laid-open Patent Publications Nos. 45688/1978, 3894/1979, 31092/1979, 39483/1979, 94591/1979, 118484/1979, 131589/1979, 75411/1980, 90510/1980, 90511/1980, 127405/1980, 147507/1980, 155003/1980, 18609/1981, 70005/1981, 72001/1981, 86905/1981, 90807/1981, 155206/1981, 3803/1982, 34103/1982, 92007/1982, 121003/1982, 5309/1983, 5310/1983, 5311/1983, 8706/1983, 27732/1983, 32604/1983, 32605/1983, 67703/1983, 117206/1983, 127708/1983, 183708/1983, 183709/1983, 149905/1984 and 149906/1984 may be employed. 
     As the magnesium compound which is the magnesium source to be used in the present invention, magnesium dihalides, dialkoxymagnesiums, alkoxymagnesium halides, magnesium oxyhalides, dialkylmagnesiums, magnesium oxide, magnesium hydroxide, carboxylates of magensium, etc. are exemplified. Among these magnesium compounds, magnesium dihalides, dialkoxymagnesiums and alkoxymagnesium halides, particularly MgCl 2 , are preferred. 
     As the titanium compound which is the titanium source, compounds represented by the formula Ti(OR 5 ) 4-c  Z c  (wherein R 5  is a hydrocarbyl group, preferably having about 1 to 10 carbon atoms, Z represents a halogen atom and c is an integer of 0≦c≦4) and polymers of a titanium tetraalkoxide. Specific examples may include: 
     titanium tetrahalides such as TiCl 4 , TiBr 4  and the like; 
     alkoxytitanium halides such as 
     Ti(OC 2  H 5 )Cl 3 , 
     Ti(OC 2  H 5 ) 2  Cl 2 , 
     Ti(OC 2  H 5 ) 3  Cl, 
     Ti(O-iC 3  H 7 )Cl 3 , 
     Ti(O-nC 4  H 9 )Cl 3 , 
     Ti(O-nC 4  H 9 ) 2  Cl 2 , 
     Ti(OC 2  H 5 )Br 3 , 
     Ti(OC 2  H 5 )(OC 4  H 9 ) 2  Cl, 
     Ti(O-nC 4  H 9 ) 3  Cl, 
     Ti(O-C 6  H 5 )Cl 3 , 
     Ti(O-iC 4  H 9 ) 2  Cl 2 , 
     Ti(OC 5  H 11 )Cl 3 , 
     Ti(OC 6  H 13 )Cl 3 , and the like; 
     and titanium tetraalkoxides such as 
     Ti(OC 2  H 5 ) 4 , 
     Ti(O-iC 3  H 7 ) 4 , 
     Ti(O-nC 3  H 7 ) 4 , 
     Ti(O-nC 4  H 9 ) 4 , 
     Ti(O-iC 4  H 9 ) 4 , 
     Ti(O-nC 5  H 11 ) 4 , 
     Ti(O-nC 6  H 13 ) 4 , 
     Ti(O-nC 7  H 15 ) 4 , 
     Ti(O-nC 8  H 17 ) 4 , 
     Ti[OCH 2  CH(CH 3 ) 2  ] 4 , 
     Ti[OCH 2  CH(C 2  H 5 )C 4  H 9  ] 4 , and the like. 
     Polymers of a titanium tetraalkoxide may include those represented by the following formula: ##STR1## wherein, R 6  -R 9  represent the same or different hydrocarbyl groups, preferably aliphatic hydrocarbyl group having 1 to 10 carbon atoms or aromatic hydrocarbyl groups, particularly aliphatic hydrocarbyl groups having 2 to 6 carbon atoms. n represents a number of 2 or more, particularly a number up to 20. The value of n should be desirably selected so that the polytitanate itself or as a solution can be provided in a liquid state for the contact step with other components. A suitable n selected in view of ease of handling may be about 2 to 14, preferably 2 to 10. Specific examples of such polytitanates may include n-butylpolytitanate (n=2 to 10), hexylpolytitanate (n=2 to 10), n-octylpolytitanate (n=2 to 10), and the like. Among them, n-butylpolytitanate is preferred. 
     It is also possible to use, as the titanium compound for the titanium source, a molecular compound obtained by reacting an electron donor as described below with a compound TiX&#39; 4  (where X&#39; represents a halogen). Specific examples may include: 
     TiCl 4 .CH 3  COC 2  H 5 , 
     TiCl 4 .CH 3  CO 2  C 2  H 5 , 
     TiCl 4 .C 6  H 5  NO 2 , 
     TiCl 4 .CH 3  COCl, 
     TiCl 4 .C 6  H 5  COCl, 
     TiCl 4 .C 6  H 5  CO 2  C 2  H 5 , 
     TiCl 4 .ClCOC 2  H 5 , 
     TiCl 4 .C 4  H 4  O, and the like. 
     Among these titanium compounds, TiCl 4 , Ti(OC 2  H 5 ) 4 , Ti(O-nC 4  H 9 ) 4 , and Ti(O-nC 4  H 9 )Cl 3  are prefered. Particularly, TiCl 4  and Ti(O-nC 4  H 9 ) 4  are prefered. 
     As to the halogen source, it is a common practice to supply the halogen from the halide compounds of magnesium and/or titanium as described above, but it can be also supplied from non halogenating agents such as halogen compounds of aluminum, halogen compounds of silicon, halogen compounds of phosphorus, and the like. 
     The halogen contained in the catalyst components may be fluorine, chlorine, bromine, iodine or a mixture of these, particularly preferably chlorine. 
     The solid component to be used in the present invention can also include, in addition to the above essential components: a silicon compound such as SiCl 4 , CH 3  SiCl 3 , and the like; a polymeric silicon compound having the structure represented by the following formula: ##STR2## (wherein R is a hydrocarbyl group having about 1 to 10, preferably about 1 to 6 carbon atoms) and having a viscosity of about 1 centistoke to 100 centistokes, such as methylhydrogenpolysiloxane, ethylhydrogenpolysiloxane, phenylhydrogenpolysiloxane, cyclohexylhydrogenpolysiloxane, 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5,7,9-pentamethylcyclopentasiloxane and the like; an aluminum compound such as Al(OiC 3  H 7 ) 3 , AlCl 3 , AlBr 3 , Al(OC 2  H 5 ) 3 , Al(OCH 3 ) 2  Cl; a boron compound such as B(OCH 3 ) 3 , B(OC 2  H 5 ) 3 , B(OC 6  H 5 ) 3  ; WCl 6  and MoCl 5 . These optional compounds may remain in the solid component as the components of silicon, aluminum and boron. 
     Further, in preparing the solid component, use can also be made of an electron donor as what is called &#34;an inside donor&#34;. 
     Examples of the electron donor or the inside donor which can be used for preparation of the solid component may include oxygen-containing electron donors such as alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of an organic acid or an inorganic acid, ethers, acid amides, acid anhydrides, and the like; and nitrogen-containing electron donors such as ammonia, amines, nitriles, isocyanates, and the like. 
     More specifically, there may be included: (a) alcohols having 1 to 18 carbon atoms, such as methanol, ethanol, propanol, pentanol, hexanol, octanol, dodecanol, octadecyl alcohol, benzyl alcohol, phenylethyl alcohol, isopropylbenzyl alcohol and the like; (b) phenols having 6 to 25 carbon atoms which may or may not have an alkyl group, such as phenol, cresol, xylenol, ethylphenol, propylphenol, isopropylphenol, nonylphenol, naphthol and the like; (c) ketones having 3 to 15 carbon atoms, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone and the like; (d) aldehydes having 2 to 15 carbon atoms, such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde, naphthaldehyde and the like; (e) organic acid esters having 2 to 20 carbon atoms, such as methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, ethyl stearate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethyl crotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluylate, ethyl toluylate, amyl toluylate, ethyl ethylbenzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, γ-butyrolactone, α-valerolactone, coumarine, phthalide, ethylene carbonate, cellosolve acetate, cellosolve isobutyrate and cellosolve benzoate, etc.; (f) inorganic acid esters, such as silicates such as ethyl silicate, butyl silicate, phenyltriethoxysilane, etc.; (g) acid halides having 2 to 15 carbon atoms, such as acetyl chloride, benzoyl chloride, toluyloic chloride, anisic chloride, phthaloyl chloride, phthaloyl isochloride and the like; (h) ethers having 2 to 20 carbon atoms, such as methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, tetrahydrofuran, anisole, diphenyl ether and the like; (i) acid amides, such as acetic amide, benzoic amide, toluyloic amide and the like; (j) amines, such as monomethylamine, monoethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, pyridine, picoline, tetramethylethylenediamine and the like; and (k) nitriles, such as acetonitrile, benzonitrile, tolunitrile and the like. One or more of these electron donors can be used in preparing the solid catalyst component. Among them, preferred are organic acid esters and acid halides, particularly preferably phthalic acid esters, phthalic acid halides, and cellosolve acetate. 
     The amounts of the above respective components used may be at any desired level, so long as the advantages inherent in the present invention can be attained, but, generally speaking, the following ranges are preferred. 
     The amount of the titanium compound used may be within the range of 1×10 -4  to 1000, preferably 0.01 to 10, in terms of molar ratio relative to the amount of the magnesium compound used. When a compound as the halogen source is used, its amount used may be within the range of 1×10 -2  to 1000, preferably 0.1 to 100, in terms of a molar ratio relative to magnesium used, irrespective of whether the titanium compound and/or the magnesium compound may contain a halogen or not. 
     The amount of the silicon, aluminum, boron, wolfram or molybdenum compound when used may be within the range of 1×10 -3  to 100, preferably 0.01 to 1, in terms of a molar ratio to the amount of the above magnesium compound used. 
     The amount of the electron donor compound when used may be within the range of 1×10 -3  to 10, preferably 0.01 to 5, in terms of a molar ratio relative to the amount of the above magnesium compound used. 
     The solid component for preparing the Sub-component (i) may be prepared from the titanium source, the magnesium source and the halogen source, and further optionally other components such as an electron donor according to methods mentioned below. 
     (a) A method in which a magnesium halide optionally together with an electron donor is contacted with a titanium compound. 
     (b) A method in which alumina or magnesia is treated with a phosphorus halide compound, and the product is contacted with a magnesium halide, an electron donor, a titanium halide-containing compound. 
     (c) A method in which the solid component obtained by contacting a magnesium halide with a titanium tetraalkoxide and a specific polymeric silicon compound is contacted with a titanium halide compound and/or a silicon halide compound. 
     As the polymeric silicon compound, those represented by the following formula are suitable: ##STR3## wherein R is a hydrocarbyl group having about 1 to 10 carbon atoms, n is a polymerization degree such that the viscosity of the polymeric silicon compound may be 1 to 100 centistokes. 
     Among them, methylhydrogenpolysiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5,7,9-pentamethylcyclopentacycloxane, ethylhydrogenpolysiloxane, phenylhydrogenpolysiloxane, and cyclohexylhydrogen polysiloxane are preferred. 
     (d) A method in which a magnesium compound is dissolved in a titanium tetraalkoxide and an electron donor, and the solid component precipitated from the solution upon addition thereto of a halogenating agent or a titanium halide compound is contacted with a titanium compound. Examples of halogenating agents include silicon halides, aluminium halides, and halogen compounds of phosphorus. 
     (e) A method in which an organomagnesium compound such as Grignard reagent, etc. is reacted with a halogenating agent, a reducing agent, etc., and then the reaction product is contacted with an electron donor and a titanium compound. 
     (f) A method in which an alkoxymagnesium compound is contacted with a halogenating agent and/or a titanium compound in the presence or absence of an electron donor. 
     Among these methods, method (c), (d) and (f) are preferable. 
     Sub-component (ii) 
     Sub-component (ii) for preparing the Component (A) is a silicon compound expressed by a formula 
     
         R.sup.1.sub.m X.sub.n Si(OR.sup.2).sub.4-m-n 
    
     wherein R 1  is a hydrocarbyl group of 1 to 20 carbon atoms, R 2  is a hydrocarbyl group of 1 to 20 carbon atoms which is the same as or different from R 1 , X is a halogen atom, and m and n are each numbers satisfying equations 0≦m≦3, 0≦n≦3 and 0≦(m+n)≦3. 
     R 1  and R 2  have 1 to 20, preferably 1 to 10, carbon atoms and may be in a branched or straight configuration, respectively. 
     X is preferably a chlorine atom at least from an economical point of view. 
     R 2  may be an aliphatic hydrocarbyl group, and preferably is a hydrocarbyl group of 1 to 4 carbon atoms. 
     Specific examples of the silicon compounds may include: 
     (CH 3 )Si(OCH 3 ) 3 , 
     (CH 3 )Si(OC 2  H 5 ) 3 , 
     (C 2  H 5 ) 2  Si(OCH 3 ) 2 , 
     (i-C 3  H 7 ) 2  Si(OCH 3 ) 2   
     (n-C 3  H 13 )Si(OCH 3 ) 3 , 
     (C 2  H 5 )Si(OC 2  H 5 ) 3 , 
     (n-C 10  H 21 )Si(OC 2  H 5 ) 3 , 
     (CH 2  ═CH)Si(OCH 3 ) 3 , 
     Cl(CH 2 ) 3  Si(OCH 3 ) 3 , 
     Si(OCH 3 ) 4 , 
     Si(OC 2  H 5 ) 3  Cl, 
     (C 2  H 5 ) 2  Si(OC 2  H 5 ) 2 , 
     (C 17  H 35 )Si(OCH 3 ) 3 , 
     Si(OC 2  H 5 ) 4 , 
     (C 6  H 5 )Si(OCH 3 ) 3 , 
     Si(OCH 3 ) 2  Cl 2 , 
     (C 6  H 5 ) 2  Si(OCH 3 ) 2 , 
     (C 6  H 5 )(CH 3 )Si(OCH 3 ) 2 , 
     (C 6  H 5 )Si(OC 2  H 5 ) 3 , 
     (C 6  H 5 ) 2  Si(OC 2  H 5 ) 2 , 
     NC(CH 2 ) 2  Si(OC 2  H 5 ) 3 , 
     (C 6  H 5 )(CH 3 )Si(OC 2  H 5 ) 2 , 
     (n-C 3  H 7 )Si(OC 2  H 5 ) 3 , 
     (CH 3 )Si(OC 3  H 7 ) 3 , 
     (C 6  H 5 )(CH 2 )Si(OC 2  H 5 ) 3 , ##STR4## (CH 3 ) 3  CSi(CH 3 )(OCH 3 ) 2 , (CH 3 ) 3  CSi(HC(CH 3 ) 2 )(OCH 3 ) 2 , 
     (CH 3 ) 3  CSi(CH 3 )(OC 2  H 5 ) 2 , 
     (C 2  H 5 ) 3  CSi (CH 3 ) ( OCH 3 ) 2 , 
     (CH 3 )(C 2  H 5 )CHSi(CH 3 )(OCH 3 ) 2 , 
     ((CH 3 ) 2  CHCH 2 ) 2  Si(OCH 3 ) 2 , 
     (C 2  H 5 )(CH 3 ) 2  CSi(CH 3 )(OCH 3 ) 2 , 
     (C 2  H 5 )(CH 3 ) 2  CSi(CH 3 )(OC 2  H 5 ) 2 , 
     (CH 3 ) 3  CSi(OCH 3 ) 3  , 
     (CH 3 ) 3  CSi(OC 2  H 5 ) 3 , 
     (C 2  H 5 ) 3  CSi(OC 2  H 5 ) 3 , 
     (CH 3 )(C 2  H 5 )CHSi(OCH 3 ) 3 , 
     (C 2  H 5 )(CH 3 ) 2  CSi(OCH 3 ) 3 , 
     (C 2  H 5 )(CH 3 ) 2  CSi(OC 2  H 5 ) 3 , 
     (C 2  H 5 ) 3  CSi(OC 2  H 5 ) 3 , 
     (CH 3 )(C 2  H 5 )CHSi(OCH 3 ) 3 , 
     ((CH 3 ) 3  C) 2  Si(OCH 3 ) 2 . 
     It is preferable that R 1  has a branch at the carbon atom adjacent to the silicon atom. The branch may preferably be an alkyl group, cycloalkyl group or aryl group such as phenyl or methyl-substituted phenyl group. More preferably, the carbon atom adjacent to the silicon atom, namely α-carbon atom, is a secondary or tertiary carbon atom in a branched hydrocarbyl group having 3 to 20 carbon atoms. Most preferably, the carbon atom connected with the silicon atom is a tertiary carbon atom in a branched hydrocarbyl group having 4 to 10 carbon atoms. 
     Sub-component (iii) 
     Sub-component (iii) for preparing a solid catalyst component in accordance with the present invention is an organometal compound of a metal of the Group I to III of the Periodic Table. 
     Examples of the metals include lithium, magnesium, aluminum and zinc, but aluminum is representable. 
     The compounds are organometal compounds and thus have at least one organic radical-metal bonding. The organic radical may typically be a hydrocarbyl group of 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. 
     The remaining valence of the metal in question other than those satisfied by an organic radical, if any, can be satisfied by a hydrogen atom, a halogen atom, hydrocarbyloxy group of 1 to 10, preferably 1 to 6, carbon atoms, or the metal itself with an oxygen bridge therebetween such as ##STR5## when the compounds are methylalminoxanes. 
     Specific examples of such organometal compounds may include: (a) organolithium compounds, e.g. methyllithium, n-butyllithium, sec.-butyllithium, tert.-butyllithium and the like; (b) organomagnesium compounds, e.g. diethylmagnesium, ethylbutylmagnesium, dibutylmagnesium, dihexylmagnesium, hexylethylmagnesium, ethylmagnesium chloride, ethylmagnesium bromide, butylmagnesium chloride, tert.-butylmagnesium bromide, and the like; (c) organozinc compounds, e.g. diethylzinc, dimethylzinc, dibutylzinc, and the like; (d) organoaluminum compounds, e.g. trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diethylaluminum chloride, diethylaluminum hydride, diethylaluminum ethoxide, ethylaluminum sesquichloride, ethylaluminum dichloride, methylaluminoxane, and the like. Among these, organoaluminum compounds and organozinc compounds, especially the former, are preferable. 
     The most preferable are organoaluminum compounds and further examples of organoaluminum compounds may be found in the examples of organoaluminum compounds as the Component (B) which will be given hereinbelow, but include: 
     Al(C 2  H 5 ) 3 , 
     Al(iC 4  H 9 ) 3 , 
     Al(nC 4  H 9 ) 3 , 
     Al(C 5  H 11 ) 3 , 
     Al(nC 6  H 13 ) 3 , 
     Al(C 8  H 17 ) 3 , 
     Al(C 10  H 21 ) 3 , 
     Al(C 2  H 5 ) 2  Cl, 
     Al(iC 4  H 9 ) 2  Cl, 
     Al(C 2  H 5 ) 2  H, 
     Al(iC 4  H 9 ) 2  H, 
     Al(C 2  H 5 ) 2  (OC 2  H 5 ). 
     Preparation of the Component (A) 
     The contacting method and conditions for the Sub-components (i) to (iii) can be as desired, so long as the advantages inherent in the present invention can be attained, but generally the following conditions are preferred. The contact temperature may be about -50° to 200° C., preferably 0° to 100° C. As the contacting method, there may be employed the mechanical method wherein a rotating ball mill, a vibrating ball mill, a jet mill, a medium stirring pulverizer or the like is used and the method in which contact is effected with stirring under the presence of an inert diluent. As the inert diluent to be used, aliphatic or aromatic hydrocarbons and halohydrocarbons, polysiloxane, etc. may be exemplified. 
     The contacting order and the contacting time of the Sub-components (i) to (iii) in preparing the component (A) of the present invention may be any desired one, so long as the advantages inherent in the present invention are attained. 
     Specific orders of such contact may include those as shown below, where the symbol &#34;+&#34; indicates a contact between the components flanking the symbol, and a washing or rinsing processing can be interposed between the contacts. 
     (a) {Sub-component (i)+Sub-component (ii)}+Sub-component (iii); 
     (b) {Sub-component (i)+Sub-component (iii)}+Sub-component (ii); 
     (c) Sub-component (i)+{Sub-component (ii)+{Sub-component (iii)}+{Sub-component (ii)+Sub-component (iii); 
     (d) {Sub-component (ii)+Sub-component (iii)}+Sub-component (i); 
     (e) Sub-component (i)+Sub-component (ii)+Sub-component (iii). 
     The quantitative ratio of the Sub-components (i) to (iii) can be any desired one, so long as the advantages inherent in the present invention can be attained, but generally preferred to be within the following ranges. 
     The quantitative ratio of the Sub-component (ii) to (i) may be within the range of 0.01 to 1000, preferably 10.1 to 100, in terms of the atomic ratio (silicon/titanium) of the silicon of the Sub-component (ii) to the titanium component constituting the Subcomponent (i). 
     The Sub-component (iii) is used in an amount within the range of 0.01 to 100, preferably 0.1 to 30, in terms of the atomic ratio of the metals {(Sub-component (iii)/titanium(Sub-component (i)}. 
     Modification of the Component (A) can be applied provided that the advantages inherent in the present invention may not be impaired. 
     One of the modification comprises use of another component other than Sub-components (i) to (iii) during the process for preparing Component (A), such as methylhydrogenpolysiloxane, ethyl borate, aluminum triisopropoxide, aluminum trichloride, silicon tetrachloride, a tetra-valent titanium compound of a formula: Ti(OR) 4-n  X n  where R is a hydrocarbyl group preferably of 1 to 6 carbon atoms, X is a halogen atom, and n is 0≦n≦4, a tri-valent titanium compound, wolfram hexachloride, molybdenum pentachloride and the like. 
     The contact product of the Sub-components (i) to (iii) is washed amply with an inert hydrocarbon solvent to form the Component (A). Particular examples of the inert hydrocarbon solvent include those conventionally used in preparing the transition metal components for Ziegler catalysts such as, for example, hexane, heptane, octane, decane, cyclohexane and toluene. 
     Component (B) 
     The component (B) is an organoaluminum compound which is a mixture of the following Sub-component (B 1 ) and Sub-component (B 2 ): 
     Sub-component (B 1 ) which is an organoaluminum compound represented by a formula 
     
         R.sup.3.sub.3-a H.sub.a Al 
    
     wherein R 3  indicates a hydrocarbyl group of 6 to 20 carbon atoms and a is a number satisfying an equation 0≦a≦1; 
     Sub-component (B 2 ) which is an organoaluminum compound represented by a formula 
     
         R.sup.4.sub.3-b AlY.sub.b 
    
     wherein R 4  indicates a hydrocarbyl group of 1 to 20 carbon atoms, Y indicates a halogen atom, and b is a number satisfying an equation 0&lt;b&lt;3. 
     Sub-component (B 1 ) 
     Sub-component (B 1 ) preferably has the substituent R 3  which has 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms. 
     Examples of the Sub-component (B 1 ) include tri-n-hexylaluminum, tri-n-octylaluminum, tri-n-decylaluminum, di-n-hexylaluminum hydride, and di-n-octylaluminum hydride. 
     Sub-component (B 2 ) 
     Sub-component (B 2 ) preferably has the substituent R 4  which has 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and the substituent Y which is a chlorine atom. 
     Examples of the Sub-component (B 2 ) include dimethylaluminum chloride, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, di-n-propylaluminum chloride, diisopropylaluminum chloride, di-n-butylaluminum chloride, iso-butylaluminum dichloride, di-n-hexylaluminum chloride, di-n-decylaluminum chloride, di-n-dodecylaluminum chloride, di-n-undecylaluminum chloride, and diethylaluminum bromide. 
     The amount of the Sub-component (B 2 ) is 0.01 to 100 moles, preferably 0.1 to 10 moles, per mole of the Subcomponent (B 1 ). 
     Making up of a catalyst 
     The catalysts in accordance with the present invention may be made up by contacting Components (A) and (B) or (A), (B) and an optional component each other at once, or step-wisely or portion-wisely, within or outside a polymerization vessel in the absence or presence of an α-olefin to be polymerized. 
     The amount of the Component (B) used may be 0.1 to 1000, preferably 1 to 100, in terms of mole ratio of Al/Ti of the Component (B)/Component (A). 
     The Components (A) and (B) can be introduced to the place where they are contacted in any suitable way, but it may be preferred to bring it into contact each in a dispersion in an aliphatic hydrocarbon such as hexane or heptane before or after they are introduced into a polymerization vessel. 
     [II] Polymerization of olefins 
     The polymerization of olefins in accordance with the present invention is characterized by, inter alia, the temperature used, which is 150° C. or higher. 
     The upper limit of the polymerization temperature may be around 300° C. The preferable temperature range may be 150° to 250° C. 
     Not only are the catalysts of the present invention applicable to ordinary slurry polymerization but they may also be used for liquid-phase, solventless polymerization wherein substantially no solvent is used, solution polymerization and vapor-phase polymerization, in a continuous or a batch-wise fashion. The catalysts in accordance with the present invention can be used not only in continuous polymerization and batchwise polymerization but also in the polymerization wherein a preliminary polymerization is conducted in which a small amount of an α-olefin is polymerized by the catalyst. In the case of slurry polymerization, aliphatic or aromatic hydrocarbons such as hexane, heptane, pentane, cyclohexane, benzene, toluene and kerosene are used alone or in combination as the polymerization solvent. The polymerization may be practiced under any pressure, preferably under a pressure of atmospheric to 1000 kg/cm 2  G, preferably atmospheric to 150 kg/cm 2 , and hydrogen can be used additionally as the molecular-weight regulator. 
     The olefins to be polymerized with the catalyst systems of the present invention are represented by the general formula: 
     
         R--CH═CH.sub.2 
    
     wherein R is a hydrocarbyl group which has 1 to 10, preferably 1 to 6, carbon atoms and may be in a linear or branch structure. 
     Specific examples of such olefins may include propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1 and 1,4-methylpentene. Preference is given to propylene, 3-methylbutene-1 and 4-methyl pentene-1, propylene being more preferable. 
    
    
     [EXPERIMENTAL EXAMPLES] 
     Example-1 
     [Preparation of Component (A)) 
     Into a flask purged with nitrogen was introduced 200 ml of dehydrated and deoxygenated n-heptane, and subsequently 0.4 mol of MgCl 2  and 0.8 mol of Ti(O-nC 4  H 9 ) 4  and the reaction was carried out at 95° C. for 2 hours. After completion of the reaction, the temperature was lowered to 40° C., followed by addition of 48 ml of methylhydrogenpolysiloxane (of 20 centistokes) and the reaction was carried out for 3 hours. The solid component formed was washed with n-heptane. 
     Into a flask purged with nitrogen was introduced 50 ml of n-heptane purified similarly as described above, and the solid component synthesized above was introduced in an amount of 0.24 mol as calculated on Mg atom. Then, a mixture of 25 ml of n-heptane with 0.8 mol of SiCl 4  was introduced into the flask at 30° C. over 30 minutes, and the reaction was carried out at 90° C. for 1 hour. After completion of the reaction, the product was washed with n-heptane. 
     Into a flask purged with nitrogen was introduced 50 ml of amply purified n-heptane, and then 5 g of the solid component obtained above, Sub-component (i), was introduced. Next, 1.2 ml of (CH 3 ) 3  CSi(CH 3 )(OCH 3 ) 2  as the silicon compound of the Sub-component (ii), and 3.0 g of triethylaluminum of the Sub-component (iii) were respectively introduced and contacted at 30° C. for 2 hours. Then, 5.8 ml of SiCl 4  as an optional component ad further 1.6 ml of the above silicon compound as the Sub-component (ii) and further 3.0 g of the above triethylaluminum as the Sub-component (iii) were introduced, followed by reaction/contact at 30° C. for 2 hours. 
     The solid product obtained was amply washed with n-heptane to provide the Component (A), which was found upon analysis on its portion to contain 3.87% by weight of titanium. 
     [Polymerization of propylene] 
     Into a polymerization vessel with a stirring and a temperature control means of 1.5 liter capacity were introduced 500 ml of amply dehydrated and deoxygenated n-paraffin, 15 mg of tri-n-hexylaluminum as Sub-component (B 1 ) and 15 mg of diethylaluminum chloride as Subcomponent (B 2 ) and 100 mg of the above synthesized Component (A). Polymerization of propylene was conducted at a temperature of 170° C. and under a pressure of 9 Kg/cm 2  G for 2 hours, after which the polymer solution obtained was subjected to treatment with methanol to separate the polymer from the n-paraffin and the polymer obtained was dried. 
     A polymer in a yield of 74.5 g was obtained. 
     The polymer had an MFR of 145 g/10 min., and the content of the fraction soluble in xylene at 20° C., which is hereinbelow referred to as CXS, was 2.66% by weight. 
     The polymer had a molecular weight distribution such that the Q-value upon the gel permeation chromatography was 8.7. 
     Example-2 
     [Preparation of Component (A)) 
     Into a flask purged with nitrogen was introduced 200 ml of dehydrated and deoxygenated n-heptane, and subsequently 0.4 mol of MgCl 2  and 0.8 mol of Ti(O-nC 4  H 9 ) 4  and the reaction was carried at 95° C. for 2 hours. After completion of the reaction, the temperature was lowered to 40° C., followed by addition of 48 ml of methylhydrogenpolysiloxane (of 20 centistokes) and the reaction was carried out for 3 hours. The solid component formed was washed with n-heptane. 
     Into a flask purged with nitrogen was introduced 50 ml of n-heptane purified similarly as described above, and the solid component synthesized above was introduced in an amount of 0.24 mol as calculated on Mg atom. Then, a mixture of 25 ml of n-heptane with 0.4 mol of SiCl 4  was introduced into the flask at 30° C. over 30 minutes, and the reaction was carried out at 70° C. for 3 hours. After completion of the reaction, the product was washed with n-heptane. 
     Then, 0.024 mole of phthaloyl chloride in 25 ml of n-heptane was introduced into the flask at 70° C. for 30 minutes and the reaction was conducted at 90° C. for 1 hour. The product was then washed with n-heptane. 20 ml of SiCl 4  was then introduced and reacted at 80° C. for 6 hours, after which the product was washed with n-heptane. The solid product produced was found to contain 1.21% of titanium. 
     Into a flask purged with nitrogen was introduced 50 ml of amply purified n-heptane, and then 5 g of the solid component obtained above, Sub-component (i), was introduced. Next, 4.8 ml of (CH 3 ) 3  CSi(CH 3 )(OCH 3 ) 2  as the silicon compound of the Sub-component (ii), 0.5 g of WCl 6  as an optional component and 4.5 g of triethylaluminum of the Sub-component (iii) were respectively introduced and contacted at 30° C. for 2 hours. After completion of the contact, the product was amply washed with n-heptane to provide a component (A), which was found to contain 1.11% by weight of titanium. 
     [Polymerization of propylene] 
     Polymerization of propylene was conducted as in Example-1 except for the use of 22 mg of tri-n-octylaluminum as Sub-component (B 1 ), 16 mg of diethylaluminum chloride as Sub-component (B 2 ) and 50 mg of the Component (A). The polymer obtained was in an amount of 49.7 g and had the CXS of 2.04% by weight, and the Q-value of 9.7. 
     Examples 3 to 5 
     Polymerization of propylene was conducted as in Example-2 except for the use of the Component (B) which is set forth in Table-1. 
     The results obtained are set forth in Table-1. 
     
                                           TABLE 1                                 
__________________________________________________________________________
Example                                                                   
     Component (B) and amount used                                        
                         Polymer                                          
                              CXS (% by                                   
                                    Q-value                               
No.  Sub-component (B.sub.1)                                              
               Sub-component (B.sub.2)                                    
                         yield (g)                                        
                              wt.)  (-)                                   
__________________________________________________________________________
3    (n-C.sub.10 H.sub.21).sub.3 Al                                       
               (C.sub.2 H.sub.5).sub.3 Al.sub.2 Cl.sub.3                  
                         47.6 1.99  9.6                                   
     (30 mg)   (24 mg)                                                    
4    (n-C.sub.8 H.sub.17).sub.3 Al                                        
               (n-C.sub.4 H.sub.9).sub.2 AlCl                             
                         44.3 2.14  9.3                                   
     (23 mg)   (38 mg)                                                    
5    (C.sub.12 H.sub.25).sub.3 Al                                         
               (n-C.sub.3 H.sub.7).sub.2 AlCl                             
                         39.6 1.95  9.4                                   
     (45 mg)   (16 mg)                                                    
__________________________________________________________________________
 
    
     Example-6 
     Polymerization of propylene was conducted as in Example-2 except for the polymerization temperature of 190° C. and for the use of 26 mg of (C 12  H 25 ) 3  Al as the Sub-component (B 1 ) and 17 mg of (n-C 4  H 9 ) 2  AlCl as the Sub-component (B 2 ). 
     The polymer obtained was in an amount of 48.7 g and had the CXS of 2.78% by weight and the Q-value of 7.9.