Catalysts for polymerization of olefins

Abstract: A catalytic ingredient for use in the polymerization of olefins comprises a carrier comprising a magnesium compound precipitated from solution and a catalytic component supported on the carrier and which is a titanium halide, vanadyl halide or vanadium halide, the catalyst being obtained by a process which comprises the steps of: (A) mixing (a) one or more magnesium compounds with (c) a saturated or unsaturated monohydric alcohol or a polyhydric alcohol, for reaction in solution in the presence of (b) carbon dioxide in an inert hydrocarbon solvent, to obtain component (A); (B) subjecting component (A) to mixing and reaction with (d) a titanium halide and/or a vanadyl halide and/or a vanadium halide and/or a silane halide together with (e) a boron compound, thereby giving solid product (I); (C) reacting solid product (I) with (f) a cyclic ether thereby causing dissolution and re-precipitation to give solid product (II); and (D) subjecting solid product (II) to further reaction with (g) component (B) consisting of a titanium halide and/or a vanadyl halide and/or a vanadium halide as defined for (d) above, thereby to give solid product (III): followed either by further reaction with a mixture of component (B) and (h) an electron donor or by reaction of (g) with the solid product (III) obtained by the reaction between the solid product (II) and (h), thereby obtaining solid product (IV) for use as the catalytic component. In modifications, the boron compound (e) may be replaced by a silane and/or siloxane compound; and/or an alcohol or polyhydric alcohol may be used in step (C).

Description: BACKGROUND OF THE INVENTION Field of the Invention This invention relates to catalysts useful for polymerization of alpha-olefins and more particularly, to a titanium halide catalytic component supported on magnesium compounds and a catalyst system comprising such a supported catalytic component. Description of the Prior Art Catalysts on magnesium-containing carriers which have high catalytic activity and good stereospecificity have been developed and are known to be suitable for vapor phase polymerization of alpha-olefins because of their advantages that the treatment of the catalyst residue in produced polymer is easy and that removal of App components is not necessary. In order to ensure good operability, the catalysts far the vapor phase polymerization of alpha-olefins are further required to have a good shape of particles with a narrow distribution of particle size, a good shatter resistance and a high bulk density. One of techniques for obtaining a controlled shape of catalyst particles is described in Japanese Laid-open Patent Application No. 63-54,405 wherein magnesium compounds are dissolved in an alcohol in the presence of carbon dioxide and treated with a mixture of a titanium halide and an organosilane to cause precipitation, to which a cyclic ether compound is added for re-dissolution and recrystallization, thereby obtaining a carrier with a good shape, and the carrier is activated to provide a catalyst. In the vapor phase polymerization of alpha-olefins wherein secondarily produced rubber components are not extracted in solvent as is different from the suspension polymerization, there are produced a number of copolymers. For the production of adhesive polymers having high rubber contents, it is necessary to keep good fluidity of polymer powder, which in turn requires the polymer powder having a large size. Accordingly, catalytic ingredients having a large particle size are required as bringing about such a large-sized powder. In general, catalyst particles prepared from a solution by a precipitation method involve the inevitable drawback that although particles of the carrier are uniform with a sharp distribution of particle size, part of the particles is broken in a subsequent activation step. In addition, particles of a larger size are more liable to break. In Japanese Laid-open Patent Application No. 63-54,405, there is the problem that when the particle size is as large as 30 µ (1µ = 1µm), the particles are broken in large amounts during the activation treatment such as with titanium halides, so that fine powder increases in amount. In Japanese Laid-open Patent Application No. 63-54,405, there is described a method for preparing a catalytic component with a good shape wherein alkaline earth metal alcoholates are dissolved as an alcohol solution by the use of carbon dioxide and a silicone compound is used for the formation of a catalytic component, followed by complexing the alkaline earth metal such as magnesium by the use of tetrahydrofuran. Many methods using silicon compounds for the formation of catalytic components have been attempted, but use of a boron compound instead of the silicon compound has never been disclosed up to now. In Japanese Laid-open Patent Application No. 63-277,204, use of a boron compound in combination with a silicon compound is set forth but the effect of the boron compound is not explained. We have made intensive studies on an improved method for the preparation of a catalytic system of the type described before wherein the catalytic component is controlled to have small to large sizes and particularly, to have an appropriate shape and an appropriate size distribution especially in large particle size while keeping good polymerization properties such as high activity and high stereoregularity. As a result, it has been found that the breakage of the particles during the preparation process of the catalytic component is prevented thereby forming a well-shaped catalytic component having a sharp size distribution. With regard to a modification of the invention, we have already proposed a method for producing a supported catalyst wherein a boron compound is used as a shape control agent at the time of precipitation from solution by which in the preparation of a catalytic component and, particularly, a particulate catalyst with a large size, the particles suffer little or only a slight degree of degradation during the treatment with titanium halide. Further studies have been made and, as a result, it has been found that a catalyst with a large size and a better crystal form can be prepared. The present invention is based on this finding. SUMMARY OF THE INVENTION It is accordingly an object of the invention to provide a catalytic component for use in polymerization of alpha-olefins which has high catalytic activity and ensure high stereospecificity, which can be controlled in a large particle size, and wherein the shape and size distribution of the catalytic particles can be properly controlled. It is another object of the invention to provide a supported catalyst on large-size carrier particles which can be obtained while preventing breakage of particles during the production process of the catalyst and are thus narrow in size distribution and uniform in size. It is a further object of the invention of the first aspect to provide a catalytic system which is comprised of the catalytic component of the type mentioned above and an organometallic compound and is adapted for use in polymerization or copolymerization of olefins. The present invention is based on the method disclosed in Japanese Laid-open Patent Application No. 63-54,405 wherein a solid precipitate is formed from an alcohol solution of a magnesium compound by treatment with a titanium halide and is re-precipitated from a solution containing a cyclic ether. The improvement resides in that the re-precipitation is effected in the presence of a boron compound, so that the resultant precipitate of the magnesium compound is unlikely to break and can be prevented from breaking in a subsequent treatment with titanium halide with a sharp size distribution. More particularly, the above objects can be achieved, according to the invention, by a catalytic component for use in polymerization of olefins which comprises a carrier mainly composed of a magnesium compound precipitated from a solution and a catalytic component supported on the carrier and selected from titanium halides, vanadyl halides and vanadium halides, the catalyst being obtained by a procedure which comprises: (A) mixing (a) a magnesium compound of the general formula, Mg(OR¹) n (OR²) 2-n or MgR³ m (OR⁴) 2-m or a mixture of these compounds wherein R¹, R², R³ and R⁴ are independently an alkyl group having from 1 to 20 carbon atoms, an aryl group, a cycloalkyl group having from 3 to 20 carbon atoms or an aromatic group having from 5 to 20 carbon atoms, and m and n are independently a value of from 0 to 2, with (c) a saturated or unsaturated monohydric alcohol of the general formula, R⁵OH, or polyhydric alcohol and each having from 1 to 20 carbon atoms for reaction in dissolved state in the presence of (b) carbon dioxide in an inert hydrocarbon solvent to obtain component (A); (B) subjecting the component (A) to mixing and reaction with (d) a titanium halide of the general formula, TiX p (OR⁶) 4-p , wherein X represents Cl or Br, R⁶ represents an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms and p is an integer of from 1 to 4, and/or a vanadyl halide of the general formula, VO Xq (OR⁷) 3-q , and/or a vanadium halide of the general formula, VX r (OR⁸) 4-r , wherein each X represents Cl or Br, R⁷ and R⁸ are independently an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms, q is an integer of from 1 to 3 and r is an integer of from 1 to 4, and/or a silane halide of the general formula, SiX s (OR⁹) 4-s wherein X represents Cl or Br, R⁹ represents an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms, and s is an integer of from 1 to 4, and also with (e) a boron compound of the general formula, BR¹⁰ t (OR¹¹) 3-t , or a mixture of these boron compounds wherein R¹⁰ and R¹¹ independently represent an alkyl group having from 1 to 20 carbon atoms, an aryl group, a cycloalkyl group having from 3 to 20 carbon atoms, or an aromatic group having from 5 to 20 carbon atoms, and t is a value of from 0 to 3, thereby obtaining solid product (I); (C) reacting the solid product (I) with (f) a cyclic ether thereby causing dissolution and re-precipitation to obtain solid product (II); and (D) subjecting the solid product (II) to further reaction with (g) component (B) consisting of a titanium halide of the general formula, TiX p (OR⁶) 4-p , wherein X represents Cl or Br, R⁶ represents an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms and p is an integer of from 1 to 4, and/or a vanadyl halide of the general formula, VO Xq (OR⁷) 3-q , and/or a vanadium halide of the general formula, VX r (OR⁸) 4-r , wherein each X represents Cl or Br, R⁷ and R⁸ are independently an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms, q is an integer of from 1 to 3 and r is an integer of from 1 to 4, thereby obtaining solid product (III), followed either by further reaction with a mixture of the component (B) and (h) an electron donor or by reaction of (g) with the solid product (III) obtained by the reaction between the solid product (II) and (h), thereby obtaining solid product (IV) for use as the catalytic component. It is preferred that in the above catalytic component, the molar ratio of titanium and magnesium is in the range of from 0.5 to 10:1 and the molar ratio of the electron donor and titanium is in the range of from 0.2 to 20:1. The solid product (IV) obtained above may be further reacted with (g) the component (B) consisting of a titanium halide of the general formula, TiX p (OR⁶) 4-p , wherein X represents Cl or Br, R⁶ represents an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms and p is an integer of from 1 to 4, a vanadyl halide of the general formula, VO Xq (OR⁷) 3-q , and a vanadium halide of the general formula, VX r (OR⁸) 4-r , wherein each X represents Cl or Br, R⁷ and R⁸ are independently an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms, q is an integer of from 1 to 3 and r is an integer of from 1 to 4. The catalytic component defined above should preferably be used in combination with an organometallic compound with or without further combination with an electron donor as a third ingredient, thereby producing a catalyst system which is particularly useful for use in polymerization of alpha-olefins. In a modification of the catalytic ingredient defined above in step (C) the solid product (I) is reacted with (f) a saturated or unsaturated monohydric alcohol of the general formula, R¹²OH (in which R¹² is a C₁-C₂₀ alkyl group, allyl group, a C₃-C₂₀ cycloalkyl or C₅-C₂₀ aromatic group), or polyhydric alcohol and each having from 1 to 20 carbon atoms and (g) a cyclic ether, followed by dissolution and re-precipitation to obtain solid product (II); and in step (D) the solid product (II) is reacted with the titanium halide and/or vanadyl halide and/or vanadium halide, followed by further reaction with a mixture of the component (B) and (j) an electron donor, thereby obtaining solid product (IV) for use as the catalytic component. The alcohol used in the step (C) should preferably be a linear alkyl alcohol having 2 to 10 carbon atoms The two figures are flow charts illustrating processes for preparing catalytic ingredients according to the invention. DETAILED DESCRIPTION AND EMBODIMENTS OF THE INVENTION The present invention is now described in more detail. Initially, the step A is described. In the step A, (a) a magnesium compound of the general formula, Mg(OR¹) n (OR²) 2-n or MgR³ m (OR⁴) 2-m or a mixture of these compounds wherein R¹, R², R³ and R⁴ are independently on alkyl group having from 1 to 20 carbon atoms, an aryl group, a cycloalkyl group having from 3 to 20 carbon atoms or on aromatic group having from 5 to 20 carbon atoms, and m and n are independently a value of from 0 to 2, is mixed with (c) saturated or unsaturated monohydric alcohol of the general formula, R⁵OH, or polyhydric alcohol and each having from 1 to 20 carbon atoms for reaction in dissolved state in the presence of (b) carbon dioxide in an inert hydrocarbon solvent to obtain component (A). The magnesium alcoholate useful in the present invention includes, for example, Mg(OCH₃)₂, Mg(OC₂H₅)₂, Mg(OC₃H₇)₂, Mg(OC₄H₉)₂, Mg(OCH(CH₃)C₂H₅)₂, Mg(OC₈H₁₇)₂, Mg(OCH₂CH(C₂H₅)C₄H₉)₂, Mg(OCH₂CHCH₂)₂, Mg(OC₆H₅)₂, Mg(OC₆H₁₁)₂, Mg(OC₆H₄CH₃)₂, Mg(OC₁₀H₇)₂, Mg(OC₁₀H₆CH₃)₂, Mg(OC₁₀H₁₇)₂, Mg(OC₁₀H₁₆CH₃)₂, Mg(OCH₃)(OC₂H₅), Mg(OC₂H₅)(OC₆H₁₃), Mg(OC₂H₅)(OC₈H₁₇) or Mg(OCH₃)(OC₆H₅). Examples of the alkyl magnesium include Mg(CH₃)₂, Mg(C₂H₅)₂, Mg(C₃H₅)₂, Mg(C₄H₉)₂, Mg(C₆H₁₃)₂, Mg(C₈H₁₇)₂, Mg(CHCHC₂H₅)₂, Mg(C₆H₅)₂, Mg(C₆H₄CH₃)₂, Mg(C₆H₁₁)₂, Mg(C₁₀H₇)₂, Mg(CH₃)(C₂H₅), Mg(C₂H₅)(C₆H₁₁) and Mg(C₃H₇)(C₆H₅). These alkyl magnesium compounds may be used singly or in combination. Aside from these compounds, Mg(OC₂H₅)(C₄H₉) and Mg(OC₃H₇)(C₆H₅) may also be used. The alcohols used as the ingredient (c) may be aliphatic saturated or unsaturated alcohols. Examples of such alcohols include methanol, ethanol, propanol, isopropanol, isobutanol, t-butanol, octanol, 2-ethylhexanol, cyclohexanol, dodecanol, propenyl alcohol, butenyl alcohol, ethylene glycol and trimethylene glycol. Of these, aliphatic alcohols having from 2 to 10 carbon atoms are preferred. In the step (B), the component (A) is subjected to reaction with (d) a titanium halide of the general formula, TiX p (OR⁶) 4-p , wherein X represents Cl or Br, R⁶ represents an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms and p is an integer of from 1 to 4, and/or a vanadyl halide of the general formula, VO Xq (OR⁷) 3-q , and/or a vanadium halide of the general formula, VX r (OR⁸) 4-r , wherein each X represents Cl or Br, R⁷ and R⁸ are independently an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms, q is an integer of from 1 to 3 and r is an integer of from 1 to 4, and/or a silane halide of the general formula, SiX s (OR⁹) 4-s wherein X represents Cl or Br, R⁹ represents an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms, and s is an integer of from 1 to 4, in the presence of (e) a boron compound of the general formula, BR¹⁰ t (OR¹¹) 3-t , or a mixture of these boron compounds wherein R¹⁰ and R¹¹ independently represent on alkyl group having from 1 to 20 carbon atoms, an aryl group, a cycloalkyl group having from 3 to 20 carbon atoms, or an aromatic group having from 5 to 20 carbon atoms, and t is a value of from 0 to 3, thereby obtaining solid product (I). This reaction is preferably carried out in an aromatic or aliphatic inert hydrocarbon solvent used in appropriate amounts. Examples of the boron compound (e) include methyl borate, ethyl borate, propyl borate, isopropyl borate, butyl borate, isobutyl borate, t-butyl borate, pentyl berate, octyl borate, 4-chlorobutyl berate, aryl berate, phenyl berate, teluyl berate, diethylcyclohexyl berate, ethyldibutoxyborane, dibutylmonoethoxyborane, triisopropylborane, tributhlborane and tricyclohexylborane. The B/Mg ratio by mole in the boron compound and the component A used in the step B is generally in the range of 0.1/1 to 2.0/1, preferably 0.3/1 to 1/1. The titanium halides of the general formula, TiX p (OR⁶) 4-p , in (d) include titanium tetrachloride, titanium tetrabromide, titanium trichloromethoxide, titanium trichloroethoxide, titanium trichloropropoxide, titaniun trichlorobutoxide, titanium trichlorohexoxide, titanium trichlorooctoxide, titanium trichlorocyclohexoxide, titanium trichlorophenoxide, titanium tribromoethoxide, titanium tribromobutoxide, titanium dichlorodiethoxide, titanium dichlorodipropoxide, titanium dichlorodibutoxide, titanium dichlorodioctoxide, titanium dichlorodiphenoxide, titanium dichlorodicyclohexoxide, titanium dibromodiethoxide, titanium dibromodibutoxide, titanium chlorotrimethoxide, titanium chlorotriethoxide, titanium chlorotributoxide, titanium chlorotriphenoxide, titanium bromotriethoxide and titanium bromotriphenoxide. The titanium halides other than titanium tetrachloride and titanium tetrabromide can be prepared by reaction between titanium tetrahalides and ortho-titanic acid esters. In place of the compounds prepared by the above reaction, there may be used mixtures of titanium tetrahalides and ortho-titanic acid esters. Of these titanium halides, titanium tetrachloride is most preferable. The vanadyl halides represented by the general formula, VOX q (OR⁷) 3-q and vanadium halide of the general formula, VX r (OR⁸) 4-r , include, for example, vanadyl trichloride, vanadyl tribromide, vanadyl dichloroethoxide, vanadyl dichlorobutoxide, vanadyl dichlorophenoxide, vanadyl dibromomethoxide, vanadyl dibromopropoxide, vanadyl dibromocyclohexoxide, vanadyl chlorodimethoxide, vanadyl chlorodiethoxide, vanadyl chlorodicyclohexoxide, vanadyl bromodipropoxide, vanadyl bromodibutoxide, vanadium tetrachloride, vanadium tetrabromide, vanadium trichloromethoxide, vanadium tribromoethoxide, vanadium trichlorobutoxide, vanadium tribromocyclohexoxide, vanadium trichlorophenoxide, vanadium dichlorodiethoxide, vanadium dibromodibutoxide, vanadium dichlorophenoxide, vanadium chlorotrimethoxide, vanadium bromotriethoxide, vanadium chlorotripropoxide, vanadium bromotributoxide and vanadium chlorotriphenoxide. The silane halides (d) represented by the general formula, SiX s (OR⁹) 4-s , include silicon tetrachloride, silicon tetrabromide, silicon tribromomethoxide, silicon trichloroethoxide, silicon trichloropropoxide, silicon trichlorobutoxide, silicon trichlorocyclohexoxide, silicon dichlorodimethoxide, silicon dibromodiethoxide, silicon dichlorodipropoxide, silicon dibromodibutoxide, silicon dichlorodiphenoxide, silicon bromotrimethoxide, silicon chlorotriethoxide, silicon bromotripropoxide and silicon chlorotributoxide. These compounds may be used singly or in combination. The molar ratio of the total metals in the titanium halide, vanadyl halide, vanadium halide and/or silane halide used in the step B and Mg in the component A is generally in the range of 1/0.3 to 20/1, preferably from 1/0.5 to 5/1. In the step C, the solid product (I) is dissolved in a solvent containing a cyclic ether (f) and re-precipitated to obtain the solid product (II). By the complete dissolution and re-precipitation, the carrier (solid product (II)) having a uniform shape and size of the particles can be obtained. In the mother liquor for the precipitation in the step C, there exists the boron compound (e) in the mother liquor of the step B. The presence of the boron compound (e) at the time of the re-precipitation has been found to show a good effect of preventing the particles from shattering or crushing in a subsequent step although the reason for this is not known at the present stage. Examples of the cyclic ether (f) include tetrahydrofuran, tetrahydropyran, methyltetrahydrofuran, dimethyltetrahydropyran, tetramethyltetrahydrofuran, dioxane, dioxorane, trioxane, pyran, benzopyran and dihydrobenzofuran. Of these, tetrahydrofuran is most preferred. In the step D, the solid product (II) is reacted with (h) a mixture of (g) the component B consisting of a titanium halide of the general formula, TiX p (OR⁶) 4-p , a vanadyl halide of the general formula, VOX q (OR⁷) 3-q and/or a vanadium halide of the general formula, VX r (OR⁸) 4-r and an electron donor, to obtain solid product (III). In the above formulae, X represents Cl or Br, R⁶, R⁷ and R⁸ independently represent an alkyl group having from 1 to 20 carbon atoms, an aryl group or a cycloalkyl group having from 3 to 20 carbon atoms, q is an integer of from 1 to 3 and p and r are independently an integer of from 1 to 4. Prior to or after the above reaction, the solid product (II) or (III) should preferably be treated with (g) the component B. The component (B) can be selected from the titanium halides, vanadyl halides and vanadium halides set forth with respect to the step B. The component B may be added to the solid product (II) or (III), or the solid product (II) or (III) may be added to the component B. The electron donor suitable for use in the mixture (h) are aromatic mono and poly-valent carboxylic acid esters. Examples of the aromatic polyvalent carboxylic acid esters include benzene polyvalent carboxylic acid esters and naphthalene polyvalent carboxylic acid esters. Specific examples of the benzene polyvalent carboxylic acid esters include: mono and diesters of benzylcarboxylic acids such as monomethyl phthalate, dimethyl phthalate, monoethyl phthalate, diethyl phthalate, dipropyl phthalate, mono-n-butyl phthalate, di-n-butyl phthalate, monoisobutyl phthalate, diisobutyl phthalate, di-n-hexyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, didecyl phthalate, dibenzyl phthalate, diphenyl phthalate, diethyl isophthalate, dipropyl isophthalate, dibutyl isophthalate, di-2-ethylhexyl isophthalate, diethyl terephthalate, dipropyl terephthalate, dibutyl terephthalate, dioctyl terephthalate, dibenzyl terephthalate and diphenyl terephthalate; mono, di and triesters of benzenetricarboxylic acids such as monobutyl hemimettlitate, dibutyl hemimettlitate, tributyl hemimettlitate, monoethyl trimellitate, dipropyl trimellitate, tributyl trimellitate, diethyl trimesiate, tributyl trimesiate and tri-2-ethylhexyl trimerisiate; mono, di, tri and tetraesters of benzenetetracarboxylic acids such as monomethyl prehnitate, diethyl prehnitate, tripropyl prehnitate, tetrabutyl prehnitate, diethldibutyl prehnitate, dibutyl mellophanate, tetrabutyl pyromellitate and dimethyldipropyl pyromellitate; and mono, di, tri, tetra, penta and hexaesters of benzenepentacarboxylic acids and mellitic acid. Specific examples of naphthalene polyvalent carboxylic acid esters include mono, di, tri, tetra and pentaesters of naphthalenedicarboxylic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid and naphthalenepentacarboxylic acid. Specific examples of the aromatic monocarboxylic acid ester include benzoic acid esters with or without substituents such as methyl benzoate, ethyl benzoate, butyl benzoate, isobutyl benzoate, cyclohexyl benzoate, methyl-p-toluate, ethyl-p-toluate, methyl-p-anisate, butyl-p-anisate, ethyl chlorobenzoate and methyl bromobenzoate. The amount of the electron donor used in the step D is in the range of from about 0.0001 to 1.0 mole, preferably from 0.005 to 0.8 moles, per gram atom of titanium or vanadium. The diluents useful in the present invention include aromatic compounds such as benzene, toluene, xylene and ethylbenzene, halogenated aromatic compounds such as chlorobenzene and dibromobenzene, alkanes such as hexane, heptane, octane, nonane, decane, undecane, cyclohexane and methylcyclohexane, halogenated alkanes such as 1,2-dichloroethane, 1,1,2-trichloroethane and carbon tetrachloride, isoparaffin hydrocarbons and kerosine. As described hereinbefore, the solid product (III) is obtained by reaction between the solid product (II) and (g) the component B, which is further reacted with (h) the mixture of the component (B) and an electron donor to obtain solid product (IV) which is the catalytic component of the invention. The reactions wherein the solid product (IV) is obtained through the solid product (II) may be effected in a reverse order of the reactions set forth above wherein (h) is initially reacted with the solid product (II) to obtain the solid product (III), which is subsequently reacted with (g) to obtain the solid product (IV). The catalytic component or product of the invention is prepared in an inert gas such as nitrogen or argon or in an atmosphere of alpha-olefin in such a condition that catalyst poisons such as water and oxygen-carbon oxide are eliminated. The purification of the diluent and starting materials used is useful for removing the catalyst poisons from the preparation system of the catalyst. As a result of the preparation, there can be obtained the solid product (IV) which is appropriately used as the catalytic component. Prior to the use of the solid product (IV), it is preferred to remove unreacted starting materials from the solid product. For the removal, after separation from the diluent, an appropriate solvent such as a liquid hydrocarbon or chlorocarbon is conveniently used to wash the solid therewith within a short time after completion of the preparation reaction. Prolonged contact between the catalytic component and unreacted starting materials nay adversely influence the properties of the final catalytic component. Although not essential, the thus obtained solid product (IV) may be in contact with at least one liquid electron acceptor prior to its use in polymerization. The electron acceptors useful in the present invention should be liquid at a treating temperature and should be those having a high Lewis acidity sufficient to eliminate impurities such as unreacted starting materials and compounds not well combined from the surface of the solid product (IV). Preferable electron acceptors are halides of the metals of Groups III to V of the Periodic Table which are liquid up to temperatures not higher than about 170°C. Specific examples include BCl₃. AlBr₃, TiCl₄, TiBr₄. SiCl₄. GeCl₄. SnCl₄, PCl₃ and SbCl₅. Preferably, TiCl₄ and SiCl₄ are mentioned. These electron acceptors may be used in combination. Such an electron acceptor may be used in a miscible diluent. Although not essential as well, it is preferred that when the solid product is washed with an inert liquid hydrocarbon prior to contact with the electron acceptor, the inert liquid should be substantially removed prior to the contact of the washed solid product with the electron acceptor. The chemical structure of the catalytic component according to the invention has never been known at present and should preferably comprise from bout 1 to 6 wt% of titanium, from 10 to 25 wt% of magnesium and 45 to 65 wt% of a halogen. A preferable catalytic component or product prepared according to the invention comprises from 1.0 to 3.0 wt% of titanium, from 15 to 21 wt% of magnesium and from 55 to 65 wt% of chlorine. The titanium-containing catalytic component of the invention may be pre-polymerized with an alpha-olefin prior to use as a catalytic component for polymerization. In the pre-polymerization, the catalytic component and an organic aluminum compound co-catalyst are contacted with an alpha-olefin under polymerization condition, preferably in the presence of a modifier such as a silane and in an inert hydrocarbon such as hexane. Preferably, the ratio by weight of the polymer and the catalyst in the pre-polymerized catalytic component is in the range of from 0.1:1 to 20:1. By the pre-polymerization, a film of the polymer is formed about individual catalyst particles and can, in most case, improve the morphology, activity, stereospecificity and wear resistance of the particles. The pre-polymerization procedure which is the most useful is described, for example, in United States Patent No. 4,579,836 referred to in the afore-mentioned Japanese Laid-open Patent Application No. 63-54,405. The titanium-containing catalytic component of the invention is used in a polymerization catalyst containing a cocatalytic component including an alkyl metal of Group II or III and typically one or more modifying compounds. Useful alkyl metals of Group II or III are of the formula, MR m , wherein M is a metal of Group II or IIIA, each R represents an alkyl group having from 1 to 20 carbon atoms, and m is a valence of M. Examples of the organometal, M, include magnesium, calcium, zinc, cadmium, aluminium and potassium. Examples of the suitable alkyl group, R, include methyl, ethyl, butyl, hexyl, decyl, tetradecyl and eicosyl. From the standpoint of the catalytic properties, preferable alkyl metals of Group II and IIIA are those of magnesium, zinc and aluminium wherein the alkyl moiety should preferably contain from 1 to 12 carbon atoms. Specific examples of the compounds include Mg(CH₃)₂, Mg(C₂H₅)₂, Mg(C₂H₅)(C₄H₉), Mg(C₄H₉)₂, Mg(C₆H₁₃)₂, Mg(C₁₂H₂₅)₂, Zn(CH₃)₂, Zn(C₂H₅)₂, Zn(C₄H₉)₂, Zn(C₄H₉)₂, Zn(C₄H₉)(C₈H₁₇), Zn(C₆H₁₃)₂, Zn(C₁₂H₂₅)₂, Al(CH₃)₃, Al(C₂H₅)₃, Al(C₃H₇)₃, Al(C₄H₉)₃, Al(C₆H₁₃)₃ and Al(C₁₂H₂₅)₃. More preferably, alkyl magnesium, zinc or aluminium whose alkyl moiety has from 1 to 6 carbon atoms are used. Best results are obtained when using trialkyl aluminium wherein each alkyl moiety has from 1 to about 6 carbon atoms, and particularly, triethyl aluminium and triisobutyl aluminium. The organoaluminium compounds are those compounds having one or more halogens or hydrides and include, for example, ethylaluminium dichloride, diethylaluminium chloride, ethylaluminium sesquichloride and diisobutylaluminium hydride. Typical catalyst compositions comprise the supported titanium-containing compound according to the invention and an alkyl aluminium compound in combination with a modifier containing an electron donor and, preferably, also with a silane compound. The atomic ratio of aluminium and titanium in this type of catalyst composition is in the range of from 10 to 500:1, preferably from 30 to 300:1. The molar ratio of the aluminium compound and the electron donor is in the range of from 5 to 40:1. Moreover, the molar ratio of the aluminium compound and the silane compound is preferably in the range of from 8 to 30:1. In order to maximize the catalytic activity and the stereospecificity in the catalyst of the invention, one or more modifiers are preferably used in combination. The modifier should be an electron donor and may be silanes, mineral acids, organometal chalcogenide derivatives of hydrogen sulfide, organic acids, organic acid esters and mixtures thereof. The organic electron donors useful as a co-catalyst modifier of the invention are organic compounds containing oxygen, silicon, nitrogen, sulfur and/or phosphorus. Such compounds include organic acids, organic acid anhydrides, organic acid esters, alcohols, ethers, aldehydes, ketones, silanes, amines, amine oxides, amides, thiols, various phosphoric acid esters and amides. If necessary, the organic electron donors may be used in combination. Preferable organic acids and esters include benzoic acid, halo-benzoic acid, phthalic acid, isophthalic acid, terephthalic acid and alkyl esters thereof whose alkyl moiety has from 1 to 6 carbon atoms, e.g. methyl benzoate, methyl bromobenzoate, ethyl benzoate, ethyl chlorobenzoate, butyl benzoate, isobutyl benzoate, methyl anisate, ethyl anisate, methyl p-toluate, hexyl benzoate, cyclohexyl benzoate, isobutyl phthalate. These compounds give good results with respect to the activity and stereospecificity and can be conveniently used. Further, aliphatic or aromatic silane modifiers are preferably mentioned as a co-catalyst for the polymerization useful in the present invention. The silanes used as the co-catalyst in the present invention should be alkyl, aryl and/or alkoxy-substituted silanes which have a hydrocarbon moiety having from 1 to 20 carbon atoms. Preferable examples are silanes of the formula, SiR₄, wherein R's independently represent R' or OR' in which R' has from 1 to 20 carbon atoms. Preferable aromatic silanes include diphenyldimethoxysilne, phenyltrimethoxysilane, and methylphenyldimethoxysilane. Preferable aliphatic silanes include isobutyltrimethoxysilane, diisobutyldimethoxysilane, diisopropyldimethoxysilane, di-t-butyl-dimethoxysilane and t-butyltrimethoxysilane are mentioned. The catalyst according to the invention is useful for use in polymerization of alpha-olefins such as ethylene and propylene and is most useful in the stereospecific polymerization of alpha-olefins having three or more carbon atoms such as, for example, propylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, and mixtures thereof with or without ethylene. When the catalytic component according to the invention is used, polyalpha-olefins having high crystallinity can be prepared by contacting at least one alpha-olefin with the catalytic component under polymerising conditions. Such conditions include polymerization temperature and time, a pressure of monomer, the manner of removing contaminants for the catalyst, the proper selection of a medium for polymerization in the slurry step, the type of additive for controlling the molecular weight of polymer and other conditions well known in the art. The polymerization may be effected by suspension, bulk and vapor phase polymerization processes. The amount of the catalyst may vary depending on the polymerization process, the size of reactor, the type of monomer to be polymerized and other factors known in the art and can be determined with reference to examples described hereinafter. Typically, the catalyst of the invention is used in an amount of from 0.2 to 0.02 mg per g of produced polymer. Irrespective of an adopted polymerization process, the polymerization is carried out at a high temperature sufficient to ensure a reasonable polymerization rate and to avoid an unduly long residence time in the reactor but at a temperature which is not so high as to bring about the production of a product with a low level of stereoirregularity caused by too high a polymerization rate. The polymerization temperature is generally in the range of from 0°C to 120°C and is preferably in the range of from 20°C to 95°C from the standpoint of good of catalytic properties and high production rates. More preferably, the polymerization is carried out at a temperature ranging from 50°C to 80°C. The polymerization of alpha-olefins according to the invention is effected at an atmospheric pressure or at a monomer pressure higher than the atmospheric pressure. In general, the pressure of monomer is in the range of about 54 KPaG (0.550 kg/cm²G) or (over). It will be noted that in the vapor phase polymerization, the monomer pressure must not be less than a vapor pressure of an alpha-olefin to be polymerized at the polymerization temperature. The polymerization time is generally in the range of from about 0.5 to several hours in a batch process. THis time corresponds to an average residence time in continuous processes, The polymerization time of from 1 hour to 4 hours is general for the reaction in an autoclave. In the slurry process, the polymerization time can be controlled as desired. The polymerization time of from 0.5 to several hours is generally in the continuous slurry process. The diluents suitable for use in the slurry polymerization process include alkanes and cycloalkanes such as pentane, hexane, heptane, n-octane, iso-octane, cyclohexane and methylcyclohexane, alkylaromatic compounds toluene, xylene, ethylbenzene, isopropylbenzene, ethyltoluene, n-propylbenzene, diethylbenzene and mono and di-alkylnaphthalenes, halogenated and hydrogenated aromatic compounds such as chlorobenzene, chloronaphthalene, ortho-dichlorobenzene, tetrahydronaphthalene and decahydronaphthalene, high molecular weight paraffins and mixtures thereof, and other known diluents. It is often desirable that prior to use, the medium for the polymerization is purified, for example, through distillation, percolation through a molecular sieve, contact with a compound capable of removing trace impurities such as an alkylaluminium compound or other means. The vapor phase polymerization process which is useful for application of the catalyst of the invention includes both an agitated bed reactor system and a fluidized bed reactor system and is described, for example, in United States Patent Nos. 3,957,448, 3,965,083, 3,971,768, 3,970,611, 4,129,701, 4,101,289, 3,652,527 and 4,003,712. These references are cited in the afore-indicated Japanese Laid-open Patent Application No. 63-54,405. A typical vapor phase olefin polymerization reaction system is comprised of a reaction vessel wherein an olefin monomer and the catalytic component are added and which includes an agitated bed for polymer particles to be formed. Typically, catalytic components are supplied at the same time or separately through one or more valve-controlled ports of the reaction vessel. The olefin monomer is typically fed into the reactor through a circulation gas system wherein the monomer withdrawn as an off-gas and a fresh starting monomer are mixed and fed into the reaction vessel. A quenching liquid which may be a liquid monomer may be added to an olefin being polymerized through the circulation gas system in order to control the temperature. Irrespective of the manner of polymerization, the polymerization should be effected under such conditions that oxygen, water and other substances capable of acting as a catalyst poison are eliminated. According to the polymerization process of the invention, the polymerization can be carried out by the use of an additive which is able to control the molecular weight of polymer. For this purpose, hydrogen may be used as is well known in the art. Although not essentially required, the catalyst may be contacted with water, an alcohol, acetone or other catalyst deactivators by a procedure known in the art at the time of completing or stopping the polymerization or at the time of deactivating the catalyst. The product prepared according to the process of the invention is usually solid in nature and is mainly composed of an isotactic polyalpha-olefin, The yield of the polymer is high relative to the amount of catalyst and can be obtained without separation of the catalytic residue. The level of a stereoregular side product is significantly low and a useful product is obtained without isolation. The polymer product prepared in the presence of the catalyst according to the invention can be processed into useful articles by extrusion molding, injection molding and other ordinary techniques. As will be apparent from the foregoing, the catalyst particles useful for polymerization of olefins are prepared under varying conditions for small and large sizes without breakage of the particles during the production process, or even if the particles are broken, the breakage can be significantly suppressed in a much smaller degree than the case using silane compounds as a shape control agent. Especially, it becomes possible to make a large-sized catalyst having a sharp size distribution. The large-sized catalyst with a sharp size distribution is kept as a replica for the polymer produced by the polymerization, so that when the polymer is formed as adhesive polymer particles, the fluidity of the polymer particles is drastically improved over the case where smaller polymer particles are produced. This is well known to one skilled in the art. This is why the catalyst of the invention is very useful in preparing copolymers having a high content of rubber component by vapor phase polymerization at high operation efficiencies. In step C of the modification, the solid product (I) is dissolved in a solvent containing (g) a cyclic ether and re-precipitated to obtain the solid product (II). By the complete dissolution and re-precipitation, the carrier (solid product (II)) having a uniform shape and size of the particles can be obtained. In the mother liquor for the precipitation in the step C, there exists the boron compound (e) in the mother liquor of the step B. The presence of the boron compound at the time of the re-precipitation has been found to show a good effect of preventing the particles from shattering or crushing in a subsequent step although the reason for this is not known at the present stage. The addition of the alcohol (f) along with the cyclic ether (g) or during the time of from the precipitation of the solid product (I) till the addition of the cyclic ether permits the formation of the carrier (solid product (II)) having a large particle size. The temperature at the time of the addition of the alcohol (f) and the cyclic ether (g) is generally in the range of from -40 to 100°C, preferably from -10 to 50°C. After the addition, the temperature is generally raised to 50 to 150°C in 1 minute to 10 hours, preferably in 5 minutes to 5 hours, at which the content is generally maintained for 1 minute to 6 hours, preferably 5 minutes to 3 hours to complete the precipitation. Examples of the cyclic ether (g) include tetrahydrofuran, tetrahydropyran, methyltetrahydrofuran, dimethyltetrahydropyran, tetramethyltetrahydrofuran, dioxane, dioxorane, trioxane, pyran, benzopyran and dihydrobenzofuran. Of these, tetrahydrofuran is most preferred. Examples of the alcohol (f) include linear alkyl alcohols such as methanol, ethanol, n-propanol, isopropanol, butanol, isobutanol, t-butanol, pentanol, hexanol, 2-ethylhexanol and octanol, cyclic alkyl alcohols such as cyclopentanol and cyclohexanol, diols such as 1,2-propanediol and 1,4-butanediol, ethylene glycol, trimethylene glycol, propenyl alcohol and butenyl alcohol. Of these, linear alkyl alcohols having from 2 to 10 carbon atoms such as ethanol, propanol, isopropanol, butanol and 2-ethylhexanol are most preferred. The present invention is more particularly described by way of examples. Comparative examples are also shown. Example 1 Step A: formation of magnesium carbonate solution 230 g of magnesium ethoxide, 415 ml of 2-ethyl-1-hexanol and 1650 ml of toluene were charged into a 3 liter autoclave equipped with an agitator, a pressure gauge and a thermometer and substituted with highly pure nitrogen. The mixture was heated at 90°C for 3 hours in an atmosphere of carbon dioxide at 196 KPaG (2 kg/cm²G) while agitating at 500 r.p.m. The resultant solution was cooled and, after purging of the carbon dioxide gas, was handled under an atmospheric pressure. The solution contained 0.1 g/ml of magnesium ethoxide. Step B: formation of solid particles 300 ml of toluene, 19 ml of TiCl₄ and 20 ml of B(OC₄H₉)₃ were charged into a 1500 ml buffled (buffling rate of 0.15) flat bottom flask equipped with an agitator, a thermometer, a condenser and a nitrogen sealing line and mixed at room temperature for 5 minutes at 300 r.p.m., followed by charging 150 ml of the solution obtained in the step A in 10 minutes. Immediately after the charging, solid particles (I) precipitated. Step C: re-precipitation of solid particles 50 ml of tetrahydrofuran (THF) was added to the precipitated solution by the use of a syringe. While agitating at 300 r.p.m., the content was heated to 60°C within 15 minutes. The precipitated particles were dissolved in the THF solution and re-precipitation started within 15 minutes and formation of solid matter completed within 10 minutes. After the agitation continued at 60°C for 45 minutes, the agitation was stopped to cause solid product (II) to be precipitated. The supernatant liquid was removed by decantation and the resultant solid product (II) was washed twice with 200 ml of toluene. Step D: treatment of titanium (IV) compound 200 ml of toluene and 100 ml of TiCl₄ were added to the solid product (II) obtained in the step C, followed by heating to 135°C in 20 minutes while agitating at 600 r.p.m., and keeping the temperature for 1 hour. The agitation was stopped to precipitate solid product (III) and the supernatant liquid was removed by decantation, 100 ml of TiCl₄, 250 ml of toluene and 2.1 ml of diisobutyl phthalate were added to the solid product (III) and the mixture was agitated at 135°C for 1.5 hours at 600 r.p.m. The supernatant liquid was removed by decantation. 200 ml of TiCl₄ was added and heated under reflux for 10 minutes while agitating at 600 r.p.m. the supernatant liquid was removed by decantation, followed by washing three times with 200 ml of toluene and four times with 200 ml of hexane. 17.4 g in total of solid product (IV) was collected, As analyzed, it contained 16.9% of magnesium, 2.4% of titanium, 55.1% of chlorine and 7.2% of di-n-butyl phthalate. Size distributions of the carrier and catalyst Part of the toluene suspension of the solid product (II) obtained in step C and part of the hexane suspension of the solid product (IV) obtained after washing with hexane in step D were sampled and subjected to measurement of a size distribution by a laser diffraction technique. The results are shown in Table 1. Vapor Phase Polymerization 2 mmols of triethylaluminum, 0.3 mmols of diphenyldimethoxysilane, 16.2 mg of the solid product (IV) and 0,8 liters of hydrogen were added to a stainless steel reactor which was substituted with nitrogen, had an inner capacity of 3 liters and was equipped with a multistage agitator, after which propylene was continuously fed and polymerised at 70°C at a total pressure of 2.16 MPaG (22 kg/cm²G) for 2 hours. Thereafter, unreacted propylene was discharged to obtain 389 g of powdery polypropylene. Most of the polypropylene particles had a cubic or inclined hexagonal crystal form. The extracting rate after extraction of the polymer with boiling n-heptane for 6 hours was 1.2 %, with a bulk density of 0.46 g/cm³. The size distribution of the polymer powder was 1.2% for >2000 µ, 45.9% for 1000 - 2000 µ, 27,7% for 710 - 1000 µ, 9.5% for 500 - 710 µ, 2.8% for 350 - 500 µ, 0,1% for 250 - 350 µ, 0% for 149 - 210%, and 0.1% for <149 µ, with an average size particle being 1084 µ. Example 2 The general procedure of Example 1 was repeated except that the solution in the step A of Example 1 was used in an amount of 114 ml, 100 ml of toluene, 100 ml of chlorobenzene and 15 ml of tri-n-butyl borate were used in step B, 60 ml of THF was used in the step C, and in the step D, 200 ml of TiCl₄ was used for the third treatment with TiCl₄ and the system was maintained at 135°C for 1 hour, thereby obtaining 13.1 g of solid product (IV). The average particle size of the solid product (IV) was 35.2 µ with particles having a size not larger than 5 µ being contained in an amount of 5.0%. Example 3 The general procedure of Example 1 was repeated except that a one liter autoclave was used for the reactions of the step B and subsequent steps, 170 ml of the solution in the step A of Example 1 was used in the step B, 200 ml of toluene and 24 ml of tri-n-butoxy borane were used in the step B, that 70 ml of THF was used in the step C and the steps of from B to C were effected while agitating at 400 r.p.m. at a pressure of carbon dioxide controlled at 294 KPaG (3 kg/cm²G), and that for the second TiCl₄ treatment in the step D, 2.1 ml of diisobutyl phthalate was used instead of the di-n-butyl phthalate. The yield of the solid product (IV) was 20.0 g and an average size of 31.8 µ with particles having a size not larger than 5 µ being 3.7%. The analytical values of the solid product were found to be 18.1% of Mg, 2.2% of Ti, 56.0% of Cl, and 8.4% of diisobutyl phthalate. Example 4 The general procedure of Example 1 was repeated except that 150 ml of the solution obtained in the step A of Example 1 was used in the step B along with 100 ml of toluene, 100 ml of chlorobenzene and 24 ml of triisopropyl borate, and that in the step C, 60 ml of THF was used. The resultant solid product (IV) had an average size of 27.2 µ and particles having a size of not larger 5 µ were 3.1% in amount. Example 5 The general procedure of Example 1 was repeated except that 114 ml of the solution obtained in the step A of Example 1 was used along with 60 ml of iso-paraffin (Isober G) and 14 ml of TiCl₄, that 27 ml of THF was used in the step C and that the TiCl₄ treatment in the step D was effected in two stages and the third washing with TiCl₄ was not effected. Example 6 The general procedure of Example 1 was repeated except that 286 g of magnesium propoxide was used in the step A in place of magnesium ethoxide along with 383 g of 2-ethyl-1-hexanol was used. Example 7 One liter of toluene, 100 ml of tri-n-butyl borate and 100 ml of TiCl₄ were charged into a 5 liter stainless steel reactor which was equipped with an agitator, a thermometer, a condenser, a nitrogen sealing line and a starting material feed line and which had a heating jacket and four flat buffles in the inside of the reactor (buffling rate of 0.15) and agitated at room temperature at 120 r.p.m. for 5 minutes, followed by charging 750 ml of the solution obtained in the step A of Example 1 in 30 minutes (step B). 250 ml of THF was further charged and agitated at an elevated agitation rate of 180 r.p.m., followed by heating up to 60°C in 15 minutes and keeping at that temperature for 45 minutes (step C). The slurry after the reaction was transferred under nitrogen sealing conditions to a 5 liter filter equipped with an agitator, a condenser, a thermometer and a nitrogen sealing line and having a heating jacket and a filter unit at the bottom thereof, and subjected to filtration, followed by washing twice with 500 ml of toluene. 500 ml of TiCl₄ and 500 ml of toluene were added to the solid product (II) in the filter and maintained at 135°C for 1 hour at 180 r.p.m. This was filtered, to which 500 ml of TiCl₄, 10.5 ml of di-n-butyl phthalate and 1000 ml of toluene were added, followed by keeping at 135°C at 180 r.p.m. for 1.5 hours and filtration (step D). 1000 ml of TiCl₄ was further added to the resultant solid product (IV) and heated under reflux for 10 minutes, followed by filtration and washing three times with 500 ml of toluene and four times with 500 ml of hexane. The solid product (IV) left in the filter was dried in a stream of hot nitrogen at approximately 60°C to obtain 81.6 g of a catalyst. The analysis of the solid product (IV) revealed 18.6% of Mg, 2.1% of Ti, and 6.6% of di-n-butyl phthalate. The average particle size of the solid product (IV) was 42.1 µ and the content of the particles having a size not larger than 5 µ was 2.2%. Comparative Example 1 The general procedure of Example 1 was repeated except that in the step B, the boron compound was not used, thereby obtaining 14.3 g of solid product (IV). In this case, a long time was required for precipitation by decantation from the step C to the step D, thus part of fine particles being lost. As shown in Table 1, fine powder was contained in very large amounts in the solid product (IV). Comparative Example 2 The general procedure of Example 1 was repeated except that 20 ml of tetraethoxysialne was used instead of the boron compound in the step B, thereby obtaining 17.1 g of solid product (IV). The size distribution of the resultant solid product is shown in Table 1. Comparative Example 3 The general procedure of Example 4 was repeated except that in the step B of Example4, 20 ml of trimethylchlorosilane was used instead of the boron compound. Evaluation on the vapor phase polymerization The solid products (IV) obtained in Examples 2 to 7 and Comparative Examples 1 to 3 were used for carrying out the vapor phase polymerization in the same manner as in Example 1. The results are shown in Table 2. Example 8 The general procedure of Example 1 was repeated except that 2 ml of tri-n-borane was used along with 18 ml of tri-n-butyl borate was used, thereby obtaining 17.3 g of solid product (IV). The solid product had an average particle size of 33 µ and the content of the particles having a size not larger than 5 µ was 5.1%. Example 9 The general procedure of Example 1 was repeated except that 60 ml of tetrahydropyran was used instead of 50 ml of THF in the step C of Example 1, thereby obtaining 17.3 g of solid product (IV). The solid product had an average particle size of 25.1 µ and the content of the particles having a size not larger than 5 µ was 7.2%. Example 10 The general procedure of Example 1 was repeated except that 24 ml of isobutyl borate was used instead of 20 ml of n-butyl borate and 60 ml of 2-methyltetrahydrofuran was used instead of 50 ml of THF in the step C of Example 1, thereby obtaining 17.5 g of solid product (IV). The solid product had an average particle size of 28.4 µ and the content of the particles having a size not larger than 5 µ was 5.9%. Comparative Example 4 The general procedure of Example 9 was repeated except that 20 ml of tetraethoxysilane was used instead of the boron compound, thereby obtaining 16.3 g of solid product (IV). The solid product contained a large amount of fine powder and the content of the particles having a size not larger than 5 µ was >25%. Comparative Example 5 The general procedure of Example 10 was repeated except that 20 ml of trimethylethoxysilane was used instead of the boron compound in the step B of Example 10, thereby obtaining 16.4 g of solid product (IV). The solid product had an average particle size of 16.4 µ and the content of the particles having a size not larger than 5 µ was 13%. Evaluation on slurry polymerization The catalysts (solid products (IV)) obtained in Examples 8 to 10 and Comparative Examples 4 to 5 were used for carrying out hexane slurry polymerization of propylene. 1000 ml of hexane was charged into a 1.5 liter autoclave, to which 2 mmols of TEA, 0.2 mmols of diphenyldimethoxysilane and from 15 mg to 17 mg of each catalyst were added, followed by introduction of 60 ml of hydrogen, keeping the pressure at 686 KPaG (7 kg/cm²G) by the addition of propylene and polymerization propylene at 70°C for 2 hours. After completion of the polymerization reaction, the monomer gas was purged and 50 g of methanol was added to the reaction system, which was subsequently agitated at 70°C for 10 minutes and subjected to filtration. The resultant polymer was dried and the yield of the polymer based on the amount of the catalyst used was calculated. The polymer dissolved in the hexane was collected from the filtrate. The results are shown in Table 3. Example 11 The catalyst obtained in Example 2 was used to carry out bulk polymerization. 2 mmols of TEA, 0.3 mmols of phenyltriethoxysilane, 10 mg of the catalyst and 300 ml of hydrogen were charged into a 1 liter bulk polymerization vessel along with 500 g of propylene, followed by polymerization at 70°C under a pressure of 3.43 MPa (35 kg/cm²) for 30 minutes. Unreacted propylene monomer was purged to obtain 170 g of a dry powder. The yield of the polymer per g of the catalyst was 17,000 g and the extracting rate after extraction with n-heptane reflux for 6 hours was 1.2% with an apparent bulk density of the polymer of 0.50 g/cm³. Example 12 10 mg of the catalyst obtained in Example 7 was used to carry out the bulk polymerization for 20 minutes in the same manner as in Example 11, after which unreacted propylene was purged and a mixed gas of propylene/ethylene = 2/1 and 150 ml of hydrogen gas were fed for vapor phase polymerization at 70°C at 1.77 MPaG (18 kg/cm²G) for 30 minutes. The yield of the polymer was 180 g and the content of ethylene in the polymer was 10.3%. Example 13 16.5 mg of the catalyst obtained in Example 7, 2 mmols of TEA, 0.2 mmols of diphenyldimethoxysilane and 150 ml of hydrogen were charged into a polymerization vessel as used in Example 1 along with propylene monomer, followed by feeding a mixed gas of propylene/ethylene = 4/1 for copolymerization at 70°C at 2.16 MPaG (22 kg/cm²G) for 1 hour. The yield of the polymer was 190 g and the content of the ethylene in the polymer was 50%. Solid Product (II) (IV) by Vapor phase polymerization Example, etc. No. Example 1 Comp. example 1 Comp. example 2 Solid Product (II) (IV) (II) (IV) (II) (IV) Diameter % % % % % % 0.9 µ 0.0 0.0 5.1 12.8 0.7 0.9 1.4 µ 0.0 0.0 6.5 11.8 0.9 1.5 1.9 µ 0.4 0.5 10.1 16.2 2.2 4.3 2.8 µ 1.1 2.5 9.6 9.9 1.2 1.4 3.9 µ 0.5 1.3 5.8 5.6 0.8 0.7 5.5 µ 0.6 0.6 2.5 4.1 0.7 0.8 7.8 µ 1.2 1.1 3.1 5.4 2.3 3.0 11.0 µ 2.1 1.7 6.6 9.0 7.1 8.5 16.0 µ 3.0 5.7 9.7 11.4 10.9 14.4 22.0 µ 9.6 13.5 20.5 10.7 21.1 25.6 31.0 µ 27.6 30.1 16.4 3.1 33.5 29.7 44.0 µ 35.9 31.5 4.2 0.0 15.2 9.2 62.0 µ 15.6 10.5 0.3 0.0 3.4 0.0 88.0 µ 2.4 1.0 0.0 0.0 0.0 0.0 Average diameter (µ) 33.4 29.0 12.8 6.7 22.6 19.3 Example Comp. example No. Result of Vapor phase Polymerization Polymer yield (g) Catalyst activity (g-pp/g-Cat.) C₆ Extructi on rate (%) Polymer apparent Bulk density (g/cm³) Example 1 389 24000 1.2 0.46 2 326 21000 1.1 0.48 3 371 24700 1.7 0.48 4 359 22000 1.4 0.45 5 213 13500 3.5 0.42 6 329 19800 1.5 0.45 7 363 23700 1.1 0.47 Comp. example 1 286 17000 2.4 0.41 2 392 24500 1.2 0.47 3 269 16300 3.1 0.42 Example Comp. example No. Result of Slurry Polymerization Polymer yield (g) Catalyst activity (g-pp/g-Cat.) C₆ Dissolution matrial C₆ Extruction residue rate Polymer apparent Bulk density (g/cm³) Example 8 126 7400 0.35 0.51 0.41 9 161 10400 2.8 5.23 0.44 10 210 13100 0.36 0.59 0.47 Comp. example 4 82 5100 0.31 0.65 0.36 5 183 10500 3.30 6.08 0.38 Example 14 Step A: formation of magnesium carbonate solution 230 g of magnesium ethoxide, 415 ml of 2-ethyl-1-hexanol and 1650 ml of toluene were charged into a 3 liter autoclave equipped with an agitator, a pressure gauge and a thermometer and substituted with highly pure nitrogen. The mixture was heated at 90°C for 3 hours in an atmosphere of carbon dioxide at 294 KPaG (3 kg/cm²G) while agitating at 500 r.p.m. The resultant solution was cooled and, after purging of the carbon dioxide gas, was handled under an atmospheric pressure. The solution contained 0.1 g/ml of magnesium ethoxide. Step B: formation of solid particles 300 ml of toluene, 19 ml of TiCl₄ and 15 ml of B(OC₄H₉)₃ were charged into a buffled (buffling rate of 0.15) flat bottom flask equipped with an agitator, a thermometer, a condenser and a nitrogen sealing line and mixed at room temperature for 5 minutes at 300 r.p.m., followed by charging 150 ml of the solution obtained in the step A in 10 minutes. Immediately after the charging, solid particles (I) precipitated. Step C: re-precipitation of solid particles 4 ml of ethanol and 50 ml of tetrahydrofuran (THF) were successively added to the precipitated solution by the use of separate syringes, While agitating at 300 r.p.m., the content was heated to 60°C within 15 minutes. The precipitated particles were dissolved in the THF solution and re-precipitation started within 15 minutes and formation of solid matter completed within 10 minutes. After the agitation continued at 60°C for 45 minutes, the agitation was stopped to cause solid product (II) to be precipitated. The supernatant liquid was removed by decantation and the resultant solid product (II) was washed twice with 200 ml of toluene. Step D: treatment of titanium (IV) compound 200 ml of toluene and 100 ml of TiCl₄ were added to the solid product (II) obtained in the step C, followed by heating to 135°C in 20 minutes while agitating at 600 r.p.m., and keeping the temperature for 1 hour. The agitation was stopped to precipitate solid product (III) and the supernatant liquid was removed by decantation. 100 ml of TiCl₄, 250 ml of toluene and 2.1 ml of diisobutyl phthalate were added to the solid product (III) and the mixture was agitated at 135°C for 1.5 hours at 600 r.p.m. The supernatant liquid was removed by decantation. 200 ml of TiCl₄ was added and heated under reflux for 10 minutes while agitating at 600 r.p.m. The supernatant liquid was removed by decantation, followed by washing three times with 200 ml of toluene and four times with 200 ml of hexane. 8.5 g in total of solid product (IV) was collected. The average particle size of the solid product (IV) was 45 µ with the content of particles having a size not larger than 5 µ being 0.1%. As analyzed, it contained 17.1% of magnesium, 2.4% of titanium, 55.3% of chlorine and 6.8% of di-n-butyl phthalate. Vapor Phase Polymerization 2 mmols of triethylaluminum, 0.3 mmols of diphenyldimethoxysilane, 16.0 mg of the solid product (IV) and 0.8 liters of hydrogen were added to stainless steel reactor which was substituted with nitrogen, had an inner capacity of 3 liters and was equipped with a multistage agitator, after which propylene was continuously fed and polymerized at 70°C at a total pressure of 2.16 MPaG (22 kg/cm²G) for 2 hours. Thereafter, unreacted propylene was discharged to obtain 384 g of powdery polypropylene. Most of the polypropylene particles had a cubic or inclined hexagonal crystal form. The remaining rate after extraction of the polymer with boiling n-heptane for 6 hours was 98.8%, with an MFR value of 3.9 and an apparent bulk density of 0.47 g/cm³. The size distribution of the polymer powder is shown in Table 5. Example 15 The general procedure of Example 14 was repeated except that the solution in the step A of Example 14 was used in an amount of 150 ml, the hydrocarbon solvent used in the step B was a mixture of 100 ml of toluene and 100 ml of chlorobenzene, 3 ml of ethanol was used along with 40 ml of THF in the step C instead of the isopropanol, and in the step D, the solid products (II) and (III) were, respectively, treated at 105°C wherein for the third treatment with TiCl₄, TiCl₄ was used as the solvent and was maintained at 105°C for 1 hour, thereby obtaining 9.3 g of solid product (IV). The average particle size of the solid product (IV) was 40.2 µ with particles having a size not larger than 5 µ being contained in an amount of 0.2%. Example 16 The general procedure of Example 14 was repeated except that 114 ml of the solution in the step A of Example 14 was used, 24 ml of tributoxy borane was used in the step B, and a mixture of 50 ml of THF and 4 ml of isobutanol was added in the step C in 1 hour, thereby obtaining 8.2 g of solid product (IV) having an average particle size of 42.3 µ. The content of particles having a size not larger than 5 µ was 0.5%. Example 17 The general procedure of Example 15 was repeated except that 7 ml of cyclohexanol was used in the step C of Example 15 along with 40 ml of THF, the temperature prior to heating during the course of from the step B to the step C was kept at a temperature -5 to 0°C, the temperature rise in the step C was gradual at 1°C/minute, and for the dilution of TiCl₄ in the step D, 100 ml of 1,2-dichloroethane was used instead of 200 to 250 ml of toluene and 2.1 ml of di-n-butyl phthalate was used instead of diisobutyl phthalate. The resultant solid product (IV) had an average particle size of 38.4 µ and the content of the particles having a size not larger than 5 µ was 0.3%. Example 18 The general procedure of Example 14 was repeated except that 170 ml of the solution in the step A of Example 14 was used, 140 ml of toluene, 60 ml of iso-paraffin (Isober G) and 24 ml of TiCl₄ were used, 10 ml of isopropanol was used along with 27 ml of THF in the step C, and the treatment with TiCl₄ in the step D was in two stages with the third washing with TiCl₄ being not carried out. The resultant solid product (IV) had an average particle size of 35.1 µ and the content of the particles having a size not larger than 5 µ was 0.8%. Example 19 The general procedure of Example 14 was repeated except that 286 g of magnesium propoxide was used in the step A in place of magnesium ethoxide, to which 457 ml of 2-ethyl-1-hexanol and 1550 ml of toluene were added and the mixture was kept at 40°C for 8 hours while agitating at 500 r.p.m. in an atmosphere of carbon dioxide at 98 KPaG (1 kg/cm²G) to make a uniform solution, after which the carbon dioxide gas was purged and the uniform solution was used as an Mg solution and that in the step C, 12 ml of 2-ethyl-1-hexanol was used instead of isopropanol. The resultant solid product had an average particle size of 40.7 µ and the content of the particles having a size not larger than 5 µ was 0.4%. Example 20 One liter of toluene, 100 ml of tri-n-butyl borate and 100 ml of TiCl₄ were charged into a 5 liter stainless steel reactor which was equipped with an agitator, a thermometer, a condenser, a nitrogen sealing line and a starting material feed line and which had a heating jacket and four flat buffles in the inside of the reactor (buffling rate of 0.15) and agitated at room temperature at 120 r.p.m. for 5 minutes, followed by charging 750 ml of the solution obtained in the step A of Example 14 in 30 minutes. 250 ml of THF and 20 ml of isopropanol were further charged into the mixture and agitated at an elevated agitation rate of 180 r.p.m., followed by heating up to 60°C in 15 minutes and keeping at that temperature for 45 minutes. The slurry after the reaction was transferred under nitrogen sealing conditions to a 5 liter filter equipped with an agitator, a condenser, a thermometer and a nitrogen sealing line and having a heating jacket and a filter unit at the bottom thereof, and subjected to filtration, followed by washing twice with 500 ml of toluene. 500 ml of TiCl₄ and 500 ml of toluene were added to the solid product (II) in the filter and maintained at 135°C for 1 hour at 180 r.p.m. This was filtered, to which 500 ml of TiCl₄, 10.5 ml of di-n-butyl phthalate and 1000 ml of toluene were added, followed by keeping at 135°C at 180 r.p.m. for 1.5 hours and filtration. 1000 ml of TiCl₄ was further added to the resultant solid product (IV) and heated under reflux for 10 minutes, followed by filtration and washing three times with 500 ml of toluene and four times with 500 ml of hexane. The solid product (IV) left in the filter was dried in a stream of hot nitrogen at approximately 60°C to obtain 51.0 g of a catalyst. The analysis of the solid product (IV) revealed 18.5% of Mg, 2.35 of Ti, 56.6% of Cl and 7.1% of di-n-butyl phthalate. The average particle size of the solid product (IV) was 45.2 µ and the content of the particles having a size not larger than 5 µ was 0.2%. Comparative Example 6 The general procedure of Example 14 was repeated except that in the step C, isopropanol was not used, thereby obtaining 16.9 g of solid product (IV). The average size of the solid product (IV) was 32.8 µ and the content of the particles having a size not larger than 5 µ was 2.1%. Comparative Example 7 The general procedure of Example 14 was repeated except that 20 ml of tetraethoxysialne was used instead of the boron compound in the step B, thereby obtaining 16.8 g of solid product (IV). The average size of the solid product was 22.4 µ and the content of the particles having 5 µ was 5.6%. Evaluation on the vapor phase polymerization The solid products (IV) obtained in Examples 15 to 20 and Comparative Examples 6 and 7 were used for carrying out the vapor phase polymerization in the same manner as in Example 14. The results are shown in Table 4. The size distribution of polymers obtained in Example 14 and with respect to Comparative Examples 6 and 7 are shown in Table 5. Example 21 The general procedure of Example 14 was repeated except that 15 ml of TiCl₄ and 5 ml of SiCl₄ were used as a precipitating agent in the step B of Example 15 and a mixed alcohol of 2 ml of isopropanol and 2 ml of ethanol was used, thereby obtaining 7.3 g of solid product (IV). The solid product had an average particle size of 36.5 µ and the content of the particles having a size not larger than 5 µ was 0.7%. Example 22 The general procedure of Example 14 was repeated except that 60 ml of tetrahydropyran was used instead of 50 ml of THF in the step C of Example 14, thereby obtaining 9.3 g of solid product (IV). The solid product had an average particle size of 35.8 µ and the content of the particles having a size not larger than 5 µ was 0.8%. Example 23 The general procedure of Example 14 was repeated except that 24 ml of isobutyl borate was used instead of 20 ml of n-butyl borate and 60 ml of 2-methyltetrahydrofuran was used instead of 50 ml of THF in the step C of Example 27, thereby obtaining 8.5 g of solid product (IV). The solid product had an average particle size of 36.1 µ and the content of the particles having a size not larger than 5 µ was 0.7%. Comparative Example 8 The general procedure of Example 22 was repeated except that there was not used the alcohol in the step C of Example 22, thereby obtaining 17.3 g of solid product (IV). The solid product had an average particle size of 25.1 µ and the content of the particles having a size not larger than 5 µ was 7.2%. Comparative Example 9 The general procedure of Example 23 was repeated except that there was not used the alcohol in the step C of Example 22, thereby obtaining 16.7 g of solid product (IV). The solid product had an average particle size of 27.1 µ and the content of the particles having a size not larger than 5 µ was 6.2%. Evaluation on slurry polymerization The catalysts (solid products (IV)) obtained in Examples 21 to 23 and Comparative Examples 8 to 9 were used for carrying out hexane slurry polymerization of propylene. 1000 ml of hexane was charged into a 1.5 liter autoclave, to which 2 mmols of TEA, 0.2 mmols of diphenyldimethoxysilane and from 15 mg to 17 mg of each catalyst were added, followed by introduction of 60 ml of hydrogen, keeping the pressure at 686 KPaG (7 kg/cm²G) by the addition of propylene and polymerizing propylene at 70°C for 2 hours. After completion of the polymerization reaction, the monomer gas was purged and 50 g of methanol was added to the reaction system, which was subsequently agitated at 70°C for 10 minutes and subjected to filtration. The resultant polymer was dried and the yield of the polymer based on the amount of the catalyst used was calculated. The polymer dissolved in the hexane was collected from the filtrate. The results are shown in Table 6. Example 24 The catalyst obtained in Example 14 was used to carry out bulk polymerization. 2 mmols of TEA, 0.3 mmols of phenyltriethoxysilane, 10 mg of the catalyst and 300 ml of hydrogen were charged into a 1 liter bulk polymerization vessel along with 500 g of propylene, followed by polymerization at 70°C under a pressure of 3.43 MPaG (35 kg/cm²G) for 30 minutes. Unreacted propylene monomer was purged to obtain 170 g of a dry powder. The yield of the polymer per g of the catalyst was 28,000 g and the remaining rate after extraction with n-heptane reflux for 6 hours was 98.5% with an MFR value of 7.8 and an apparent bulk density of the polymer of 0.50 g/cm³. Example 25 10 mg of the catalyst obtained in Example 20 was used to carry out the bulk polymerization for 20 minutes in the same manner as in Example 24, after which unreacted propylene was purged and a mixed gas of propylene/ethylene = 2/1 and 150 ml of hydrogen gas were fed for vapor phase polymerization at 70°C at 1.77 MPaG (18 kg/cm²G) for 30 minutes. The yield of the polymer was 192 g with a T-MFR value of 1.4, and the content of ethylene in the polymer was 10.3%. Example 26 16.5 mg of the catalyst obtained in Example 20, 2 mmols of TEA, 0.2 mmols of diphenyldimethoxysilane and 150 ml of hydrogen were charged into a polymerization vessel as used in Example 14 along with propylene monomer, followed by feeding a mixed gas of propylene/ethylene = 4/1 for copolymerization at 70°C at 2.16 MPaG (22 kg/cm²G) for 1 hour. The yield of the polymer was 217 g and the content of the ethylene in the polymer was 50%. Example Comp. example No. Result of Vapor phase Polymerization Catalyst activity (g-pp/g-Cat.) C₇Extruction residue rate (%) MFR (g/10min) Polymer apparent Bulk density (g/cm³) Example 15 23700 98.9 2.8 0.48 16 21000 98.5 3.6 0.46 17 22100 98.7 3.0 0.45 18 19500 97.9 4.1 0.44 19 23900 99.0 3.7 0.47 20 24700 98.9 3.1 0.48 Comp. example 6 24000 98.8 2.6 0.46 7 17500 97.6 6.1 0.41 Polymer Particle size distribution obtained by Vapor phase polimerization Example 14 Comp. example 6 Comp. example 7 Powder diameter (%) (%) (%) 2000 µ< 8.3 0.0 0.0 1400-2000 µ 50.1 3.7 0.6 1000-1400 µ 37.9 41.5 7.5 710-1000 µ 2.6 33.2 39.2 500- 710 µ 0.6 17.3 34.7 355- 500 µ 0.3 2.6 12.5 250- 355 µ 0.1 0.7 2.3 180- 250 µ 0.1 0.6 0.9 106- 180 µ 0 0.3 1.3 < 106 µ 0 0.1 1.0 Average diameter (µ) 1490 µ 952 µ 691 µ

Claims: A catalytic ingredient for use in the polymerization of olefins which comprises a carrier comprising a magnesium compound precipitated from solution and a catalytic component supported on the carrier and which is a titanium halide, vanadyl halide or vanadium halide, the catalyst being obtained by a process which comprises the steps of: (A) mixing (a) one or more magnesium compounds of the formulae Mg(OR¹) n (OR²) 2-n and/or MgR 3 / m(OR⁴) 2-m (in which R¹, R², R³ and R⁴ are the same or are different and each is a C₁-C₂₀ alkyl group, an allyl group, a C₃-C₂₀ cycloalkyl group or a C₅-C₂₀ aromatic group; and m and n are the same or are different and each has a value of from 0 to 2), with (c) a saturated or unsaturated monohydric alcohol of the general formula, R⁵OH (in which R⁵ is a C₁-C₂₀ alkyl group, allyl group, a C₃-C₂₀ cycloalkyl group, or a C₅-C₂₀ aromatic group), or a polyhydric alcohol having from 1 to 20 carbon atoms, for reaction in solution in the presence of (b) carbon dioxide in an inert hydrocarbon solvent, to obtain component (A); (B) subjecting component (A) to mixing and reaction with (d) a titanium halide of the formula TiX p (OR⁶) 4-p and/or a vanadyl halide of the formula VOX q (OR⁷) 3-q and/or a vanadium halide of the formula VX r (OR⁸) 4-r and/or a silane halide of the formula SiX s (OR⁹) 4-s (in which X is Cl or Br; each of R⁶, R⁷, R⁸ and R⁹ is a C₁-C₂₀ alkyl group, an allyl group or C₃-C₂₀ cycloalkyl group; each of p, r and s is an integer of from 1 to 4; and q is an integer of from 1 to 3); together with (e) a boron compound of the formula BR 10 / t (OR¹¹) 3-t (in which R¹⁰ and R¹¹ are each a C₁-C₂₀ alkyl group, or allyl group, a C₃-C₂₀ cycloalkyl group or a C₅-C₂₀ aromatic group; and t has a value of from 0 to 3), thereby giving solid product (I); (C) reacting solid product (I) with (f) a cyclic ether thereby causing dissolution and re-precipitation to give solid product (II); and (D) subjecting solid product (II) to further reaction with (g) component (B) consisting of a titanium halide and/or a vanadyl halide and/or a vanadium halide as defined for (d) above, thereby to give solid product (III): followed either by further reaction with a mixture of component (B) and (h) an electron donor or by reaction of (g) with the solid product (III) obtained by the reaction between the solid product (II) and (h), thereby obtaining solid product (IV) for use as the catalytic component. A catalytic ingredient according to claim 1 wherein the molar ratio of titanium to magnesium is from 0.5:1 to 10:1 and the molar ratio of the electron donor to titanium is from 0.2:1 to 20:1. A catalytic ingredient according to claim 1, wherein the solid product (IV) is further reacted with (g) the component (B) consisting of a titanium halide and/or vanadyl halide and/or vanadium halide as defined under (d) in claim 1. A modification of the catalytic ingredient claimed in claim 1 in which; (i) in step (C) the solid product (I) is reacted with a saturated or unsaturated monohydric alcohol of the general formula, R¹²OH, (in which R¹² is a C₁-C₂₀ alkyl group, allyl group, a C₃-C₂₀ cycloalkyl or C₅-C₂₀ aromatic group) or a polyhydric alcohol having up to 20 carbon atoms, and (g) a cyclic ether, followed by dissolution and re-precipitation to give a solid product (II); and (ii) in step (D) solid product (II) is reacted with the titanium halide and/or vanadyl halide and/or vanadium halide, followed by further reaction with a mixture of the component (B) and an electron donor, thereby obtaining solid product (IV) for use as the catalytic component. A catalytic ingredient according to claim 4 wherein the molar ratio of B in the boron compound used in step B to Mg in component A is from 0.1/1 to 2.0/1. A catalytic ingredient according to claim 5 wherein the molar ratio of total metals in the titanium halide, vanadyl halide, vanadium halide and/or silane halide to Mg in component A is from 1/0.3 to 20/1. A catalytic ingredient according to any one of claims 4-6 in which the alcohol used in Step C is a C₂-C₂₀ linear alcohol. A catalytic ingredient according to any one of the preceding claims wherein the cyclic ether used in step (C) is tetrahydrofuran. The catalytic ingredient according to any one of the preceding claims wherein the electron donor is an aromatic mono or polycarboxylic acid ester. A catalytic ingredient according to any one of the preceding claims wherein the electron donor material is used in an amount of about 0.0001 to 1.0 mole per gram atom of titanium or vanadium contained in solid product (III). A catalyst for the polymerisation of olefins comprising a catalytic component as claimed in any one of the preceding claims together with an organometallic compound. A catalyst as claimed in claim 11 further comprising an electron donor.

Inventors: HAYASIDA TERUAKI, MATUKAWA TETUYA, TACHIBANA MASAMI, UWAI TOSHIHIRO, HAYASIDA, TERUAKI, MATUKAWA, TETUYA, TACHIBANA, MASAMI, UWAI, TOSHIHIRO
Applicants: CHISSO CORP, CHISSO CORPORATION
Application year: 1990
Main classification: C08F4
IPC codes: C08F4, C08F10