Catalyst for .alpha.-olefin polymerization and process for producing .alpha.-olefin polymer

A catalyst for .alpha.-olefin polymerization obtained by contacting (A) a solid catalyst component containing a titanium compound which is obtained by treating a solid product obtained by contacting an organosilicon compound having an Si--O bond, an ester compound and an organomagnesium compound, with an ether compound, titanium tetrachloride and an acyl halide, and successively treating said treated solid with an mixture of an ether compound and titanium tetrachloride, or a mixture of an ether compound, titanium tetrachloride and an ester compound, (B) an organoaluminum compound and (C) an electron-donative compound, and a process for producing an .alpha.-olefin polymer with the catalyst.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to a catalyst for .alpha.-olefin
 polymerization and a process for producing an .alpha.-olefin polymer. More
 specifically, the present invention relates to a catalyst for
 .alpha.-olefin polymerization which provides an .alpha.-olefin polymer
 having a high isotacticity, containing an extremely small amount of a
 catalyst residue and an amorphous polymer and being excellent in
 mechanical properties and a processability, at an extremely high catalytic
 activity based on a solid catalyst component and on titanium atom, and a
 process for producing an .alpha.-olefin polymer
 2. Description of the Related Arts
 It has been well known as a process for producing isotactic polymers of an
 .alpha.-olefin (e.g., propylene, 1-Butene) that so-called Ziegler-Natta
 catalyst comprising a solid catalyst component obtained by using a
 transition metal compound of Groups 4 to 6 of the Periodic Table and
 specific organometallic compounds.
 When an .alpha.-olefin polymer is produced, an amorphous polymer is
 produced in addition to a highly stereoregular .alpha.-olefin polymer
 having a high value for industrial application. The amorphous polymer has
 a little value for industrial application and badly influences mechanical
 properties when the .alpha.-olefin polymer is molded to a shaped article,
 a film, a fiber or other fabricated articles to be used. Further, the
 by-production of the amorphous polymer causes a loss of a raw material
 monomer, and at the same time, equipment for removing the amorphous
 polymer is required, which causes a disadvantage from an industrial view
 point. Therefore, it is preferable that a catalyst used for producing an
 .alpha.-olefin polymer has no formation of such an amorphous polymer, or
 scarcely little even if formed.
 Further, catalyst residues of the transition metal component and the
 organometallic component remain in the .alpha.-olefin polymer obtained.
 Equipment for removing the catalyst residues is required for removal and
 deactivation of the catalyst residues, because the catalyst residues may
 cause problems in various points such as the stability and processability
 of the .alpha.-olefin polymer and the like.
 The problem can be improved by increasing the catalytic activity which is
 represented by the weight of the produced .alpha.-olefin polymer per unit
 weight of the catalyst, and the above-mentioned equipment for removing
 catalyst residues becomes unnecessary, and it can reduce the production
 cost of the .alpha.-olefin polymer.
 It is known that a Ti--Mg complex-type solid catalyst which is obtained by
 reducing a tetravalent titanium compound with an organomagnesium compound
 in the presence of an organosilicon compound to form an eutectic crystal
 of magnesium and titanium, can realize .alpha.-olefin polymerization of
 relatively high stereoregularity and high activity by being used in
 combination with an organoaluminum compound as a co-catalyst and an
 organosilicon compound as a third component to the polymerization
 (Japanese Patent Publication (Examined) Hei No.3-43283 and Japanese Patent
 Publication (Unexamined) Hei No.1-319508).
 It is disclosed that a polymerization giving higher stereoregularity and
 higher activity can be realized by the coexistence of an additional ester
 when a tetravalent titanium compound is reduced with an organomagnesium
 compound in the coexistence of an organosilicon compound, in the
 above-mentioned process (Japanese Patent Publication (Unexamined) Hei
 No.7-216017).
 Further, it is known that a highly stereoregular .alpha.-olefin polymer can
 be produced at a high polymerization activity with a solid catalyst
 synthesized by treating a reaction product of an organomagnesium compound
 with an alcohol, with titanium tetrachloride, an alkoxy titanium compound
 and phthaloyl chloride and then repeating contact treatment with titanium
 tetrachloride 3 times (Japanese Patent Publication (Unexamined) Hei
 No.8-231630).
 A process free from an extraction and deashing is at the possible level,
 but further improvement is desired. Specifically, it is desired that
 highly stereoregular polymerization is realized without sacrificing a
 particle size distribution and the like in order to make an .alpha.-olefin
 polymer of high quality. In particular, since a highly stereoregular
 polymer directly causes a quality of high rigidity in a use for an
 injection molding field in which a polymer of high rigidity is desired,
 the appearance of a catalyst having a capability for a polymerization of
 higher stereoregularity, has been desired.
 Further, when a solid catalyst such as the Ziegler-Natta catalyst is used
 for industrial application, its particle shape and particle size
 distribution are very important for controlling the bulk density of a
 polymer, particle size and flowability. With respect of improving the
 particle shape and narrowing the particle size distribution, trials to
 overcome these problems have been carried out, using a solid catalyst
 prepared by supporting a titanium-magnesium compound on a silica gel in
 the polymerization of ethylene (Japanese Patent Publication (Unexamined)
 Show No.54-148098 and Japanese Patent Publication (Unexamined) Show
 No.56-47407).
 It is disclosed in Japanese Patent Publication (Unexamined) Sho
 No.62-256802 that particle properties are markedly improved by using a
 solid catalyst obtained by impregnating a titanium-magnesium compound in
 silica gel, in the polymerization of propylene.
 Although an improvement effect on particle shape is surely recognized
 according to these processes, it is not preferable from a quality
 viewpoint that a large amount of silica gel used as the carrier remains in
 the final products, which happens to cause fish eye in film use. Further,
 polymerization activity is also low and productivity cannot be satisfied.
 Accordingly, a solid catalyst component having an excellent catalyst shape
 and narrow particle size distribution and a polymerization capability of
 high activity and high stereoregularity is seriously desired.
 SUMMARY OF THE INVENTION
 An object of the present invention is to provide a process for producing a
 highly stereoregular .alpha.-olefin polymer containing little fine powder
 and having good powder properties, and a catalyst for .alpha.-olefin
 polymerization, capable of producing said .alpha.-olefin polymer at a high
 enough catalytic activity to make the removal of catalyst residues and an
 amorphous polymer unnecessary.
 The present invention relates to a catalyst for .alpha.-olefin
 polymerization obtained by a process comprising contacting together:
 (A) a solid catalyst component containing a titanium compound, which is
 obtained by treating a solid product obtained by contacting an
 organosilicon compound having an Si--O bond, an ester compound and an
 organomagnesium compound with an ether compound, titanium tetrachloride
 and an acyl halide, and successively treating said treated solid with a
 mixture of an ether compound and titanium tetrachloride, or a mixture of
 an ether compound, titanium tetrachloride and an ester compound;
 (B) an organoaluminum compound; and
 (C) an electron-donative compound, and a process for producing an
 .alpha.-olefin polymer which comprises homopolymerizing an .alpha.-olefin,
 or copolymerizing an .alpha.-olefin with ethylene or another
 .alpha.-olefin with said catalyst.

DETAILED DESCRIPTION OF THE INVENTION
 The present invention is specifically illustrated below.
 (a) Organosilicon Compound having Si--O Bond
 As the organosilicon compound having an Si--O bond which is used in the
 synthesis of the solid catalyst component of the present invention, for
 example, those represented by the general formulae described below can be
 used:
EQU Si(OR.sup.2).sub.m R.sup.3.sub.4-m,
EQU R.sup.4 (R.sup.5.sub.2 SiO).sub.p R.sup.6.sub.3,
 or
EQU (R.sup.7.sub.2 SiO).sub.q,
 wherein R.sup.2 is a hydrocarbon group having 1 to 20 carbon atoms, each of
 R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 is a hydrocarbon group
 having 1 to 20 carbon atoms or a hydrogen atom, m is a number satisfying
 an equation of 0&lt;m.ltoreq.4, p is an integer of 1 to 1000, and q is an
 integer of 2 to 1000.
 Specified examples of the organosilicon compound include
 tetramethoxysilane, dimethyldimethoxysilane, tetraethoxysilane,
 triethoxyethylsilane, diethoxydiethylsilane, ethoxytriethylsilane,
 tetraisopropoxysilane, diisopropoxydiisopropylsilane, tetrapropoxysilane,
 di-n-propoxydi-n-propylsilane, tetra-n-butoxysilane,
 di-n-butoxydi-n-butylsilane, dicyclopentoxydiethylsilane,
 diethoxydiphenylsilane, cyclohexyloxytrimethylsilane,
 phenoxytrimethylsilane, tratraphenoxysilane, triethoxyphenylsilane,
 hexamethyldisiloxane, hexaethyldisiloxane, hexa-n-propyldisiloxane,
 octaethyltrisiloxane, dimethylpolysiloxane, diphenylpolysiloxane,
 methylhydropolysiloxane, phenylhydropolysiloxane and the like.
 Among these, alkoxysilanes represented by the general formula,
 Si(OR.sup.2).sub.m R.sup.3.sub.4-m, are preferable, wherein m is
 preferably a number satisfying an equation of 1.ltoreq.m.ltoreq.4 and in
 particular, tetraalkoxysilanes of which m is 4 are preferable.
 (b) Ester Compound
 As the ester compound used in the present invention, mono- and poly-valent
 carboxylic acid esters are used, and examples thereof include aliphatic
 carboxylic acid esters, alicyclic carboxylic acid esters and aromatic
 carboxylic acid esters. Specific examples include methyl acetate, ethyl
 acetate, phenyl acetate, methyl propionate, ethyl propionate, ethyl
 butyrate, ethyl valerate, methyl acrylate, ethyl acrylate, methyl
 methacrylate, ethyl benzoate, n-butyl benzoate, methyl toluate, ethyl
 toluate, ethyl anisate, diethyl succinate, di-n-butyl succinate, diethyl
 malonate, di-n-butyl malonate, dimethyl maleate, di-n-butyl maleate,
 diethyl itaconate, di-n-butyl itaconate, monoethyl phthalate, dimethyl
 phthalate, methylethyl phthalate, diethyl phthalate, di-n-propyl
 phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl
 phthalate, di-n-octyl phthalate, diphenyl phthalate and the like. Among
 these esters, unsaturated aliphatic carboxylic acid esters such as
 methacrylates, maleates and the like, and aromatic dicarboxylic acid
 diesters are preferable and in particular, phthalic acid diesters are
 preferably used.
 (c) Organomagnesium Compound
 Any type of an organomagnesium compound having an Mg-carbon bond can be
 used as the organomagnesium compound used in the present invention. In
 particular, a Grignard compound represented by the general formula,
 R.sup.8 MgX, (wherein R.sup.8 represents a hydrocarbon group having 1 to
 20 carbon atoms, and X represents a halogen atom) or a
 dihydrocarbylmagnesium compound represented by the general formula,
 R.sup.9 R.sup.10 Mg, (wherein R.sup.9 and R.sup.10 represent a hydrocarbon
 group having 1 to 20 carbon atoms) is suitably used. Wherein R.sup.8,
 R.sup.9 and R.sup.10 may be the same or different, and an alkyl group
 having 1 to 20 carbon atoms, an aryl group having up to 20 carbon atoms,
 an aralkyl group having up to 20 carbon atoms and an alkenyl group having
 up to 20 carbon atoms such as a methyl group, ethyl group, n-propyl group,
 isopropyl group, n-butyl group, sec-butyl group, n-amyl group, isoamyl
 group, n-hexyl group, n-octyl group, 2-ethyl-n-hexyl group, phenyl group,
 benzyl group and the like are exemplified.
 Specific examples of the Grignard compound include methylmagnesium
 chloride, ethylmagnesium chloride, ethylmagnesium bromide, ethylmagnesium
 iodide, n-propylmagnesium chloride, n-propylmagnesium bromide,
 n-butylmagnesium chloride, n-butylmagnesium bromide, sec-butylmagnesium
 chloride, sec-butylmagnesium bromide, tert-butylmagnesium chloride,
 tert-butylmagnesium bromide, amylmagnesium chloride, isoamylmagnesium
 chloride, n-hexylmagnesium chloride, phenylmagnesium chloride, and
 phenylmagnesium bromide and the like. Specific examples of the compound
 represented by the general formula, R.sup.9 R.sup.10 Mg, include
 dimethylmagnesium, diethylmagnesium di-n-propylmagnesium,
 diisopropylmagnesium, di-n-butylmagnesium, di-sec-butylmagnesium,
 di-tert-butylmagnesium, butyl-sec-butylmagnesium, di-n-amylmagnesium,
 di-n-hexylmagnesium, diphenylmagnesium, butylethylmagnesium and the like.
 As a solvent for the synthesis of the above-mentioned organomagnesium
 compound, an ether solvent such as diethyl ether, di-n-propyl ether,
 diisopropyl ether, di-n-butyl ether, diisobutyl ether, di-n-amyl ether,
 diisoamyl ether, di-n-hexyl ether, di-n-octyl ether, diphenyl ether,
 dibenzyl ether, phenetole, anisole, tetrahydrofuran, tetrahydropyran or
 the like is usually used. Further, a hydrocarbon solvent such as hexane,
 heptane, octane, cyclohexane, methylcyclohexane, benzene, toluene, xylene
 or the like, or a mixed solvent of the ether solvent and the hydrocarbon
 solvent is also used.
 The organomagnesium compound in the present invention is preferably used in
 the form of an ether solution. As the ether compound in this case, an
 ether compound having six or more carbon atoms in its molecule and an
 ether compound having a cyclic structure is used. Further, it is
 preferable from the viewpoint of catalytic ability that the Grignard
 compound represented by the general formula, R.sup.8 MGX, is used in the
 form of an ether solution.
 Moreover, a hydrocarbon-soluble complex of the above-mentioned
 organomagnesium compound with an organometallic compound can be also used.
 Examples of such organometallic compounds include organic compounds of Li,
 Be, B, Al or Zn.
 (d) Ether Compound
 The ether compounds used for treatment in the present invention include
 dialkyl ethers having two alkyl groups of 1 to 20 carbon atoms such as
 diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-butyl ether,
 diisobutyl ether, di-n-amyl ether, diisoamyl ether, dineopentyl ether,
 di-n-hexyl ether, di-n-octyl ether, methyl-n-butyl ether, methylsioamyl
 ether, ethylisobutyl ether and the like. Among these, di-n-butyl ether or
 diisoamyl ether is preferably used.
 (e) Acyl Halide Compound
 As the acyl halide compound, Mono- and poly-valent carboxylic acid halides
 are used. Examples thereof include aliphatic carboxyl halides, alicyclic
 carboxyl halides and aromatic carboxyl halides. Specific examples include
 acetyl chloride, propionyl chloride butyroyl chloride, valeroyl chloride,
 acryloyl chloride, methacryloyl chloride, benzoyl chloride, toluyl
 chloride, anisyl chloride, succinyl chloride, malonyl chloride, maleyl
 chloride, itaconoyl chloride, phthaloyl chloride and the like. Among these
 organic acid halide compounds, aromatic carboxylic acid chlorides such as
 benzoyl chloride, toluyl chloride, phthaloyl chloride and the like are
 preferable, aromatic dicarboxylic acid dichlorides are more preferable,
 and phthaloyl chloride is more preferably used.
 (f) Synthesis of Solid Catalyst Component
 The solid catalyst component (A) in the present invention is obtained by:
 contacting an organosilicon compound having an Si--O bond, an ester
 compound and an organomagnesium compound to obtain a solid product;
 treating said solid product with an ether compound, titanium tetrachloride
 and an acyl halide to obtain a treated solid; and successively treating
 said treated solid with a mixture of an ether compound and titanium
 tetrachloride, or a mixture of an ether compound, titanium tetrachloride
 and an ester compound. All of these synthesis reactions are carried out
 under an atmosphere of an inert gas such as nitrogen, argon or the like.
 As the method of contacting an organosilicon compound, an ester compound
 and an organomagnesium compound, any one of a method of adding the
 organomagnesium compound (c) to a mixture of the organosilicon compound
 (a) and the ester compound (b), or on the contrary, a method of adding a
 mixture of the organosilicon compound (a) and the ester compound (b) to
 the organomagnesium compound (c), or the like may be used. Among these,
 the method of adding the organomagnesium compound (c) to a mixture of the
 organosilicon compound (a) and the ester compound (b) is preferable from
 the viewpoint of the catalytic activity.
 It is preferable that the organosilicon compound and/or the ester compound
 are dissolved in or diluted with an appropriate solvent to be used. Such
 solvent includes an aliphatic hydrocarbon such as hexane, heptane, octane,
 decane and the like, an aromatic hydrocarbon such as toluene, xylene and
 the like, an alicyclic hydrocarbon such as cyclohexane, methylcyclohexane,
 decalin and the like, and an ether compound such as diethyl ether,
 di-n-butyl ether, diisoamyl ether, tetrahydrofuran and the like.
 The contacting temperature is usually in the range of about -50 to about
 70.degree. C., preferably in the range of about -30 to about 50.degree.
 C., and more preferably in the range of about -25 to about 35.degree. C.
 When the reaction temperature is too high, the catalytic activity
 deteriorates.
 Further, a porous substance such as an inorganic oxide, an organic polymer
 or the like may coexist in the contact, so that the solid product can be
 impregnated in the porous substance. Such porous substance has preferably
 a pore volume of about 0.3 ml/g or more in the pore radius range of 20 to
 200 nm and a mean particle diameter of 5 to 300 .mu.m.
 The porous inorganic oxides include SiO.sub.2, Al.sub.2 O.sub.3, MgO,
 TiO.sub.2, ZrO.sub.2, SiO.sub.2.Al.sub.2 O.sub.3 complex oxide,
 MgO.Al.sub.2 O.sub.3 complex oxide, MgO.SiO.sub.2.Al.sub.2 O.sub.3 complex
 oxide and the like. The porous polymers include styrene-based polymers,
 acrylate-based polymers, acrylonitrile-based polymers, vinyl
 chloride-based polymers and olefin-based polymers represented by
 polystyrene, a styrene-divinylbenzene copolymer, a styrene-n,n'-alkylene
 dimethacrylamide copolymer, a styrene-ethylene glycol methyl
 dimethacrylate copolymer, a poly(ethylacrylate), methyl
 acrylate-divinylbenzene copolymer, an ethylacrylate-divinylbenzene
 copolymer, a poly(methylmethacrylate), a methylmethacrylate-divinylbenzene
 copolymer, a poly(ethylene glycol methyldimethacrylate), a
 polyacrylonitrile, a acrylonitrile-divinylbenzene copolymer, a poly(vinyl
 chloride), a poly(vinyl pyrrolidine), a poly(vinyl pyridine), an
 ethylvinylbenzene-divinylbenzene copolymer, polyethylene, an
 ethylene-methylacrylate copolymer, polypropylene and the like. Among these
 porous substances, SiO.sub.2, Al.sub.2 O.sub.3 and a
 styrene-divinylbenzene copolymer are preferably used.
 The time of dropwise addition is not specifically restricted, but is
 usually about 30 minutes to about 12 hours. After completion of the
 addition, post-reaction may be further carried out at a temperature of
 about 20 to about 120.degree. C.
 The amount of the ester compound (b) used is generally in the range of
 (b)/Mg=0.001 to 1 in terms of a molar ratio of the ester compound to
 magnesium atom, preferably about 0.005 to about 0.6, and preferably about
 0.01 to about 0.3 in particular. The amount of the magnesium compound (c)
 used is generally in the range of Si atom/Mg atom=0.1 to 10 in terms of an
 atomic ratio of silicon atom of the organosilicon compound having an Si--O
 bond to magnesium atom, preferably about 0.2 to about 5.0, and more
 preferably about 0.5 to about 2.0.
 The solid product obtained by the reaction is usually separated from the
 solution and washed several times with an inert hydrocarbon solvent such
 as hexane, heptane or the like. The solid product thus obtained has a
 magnesium atom and a hydrocarbyloxy group, and usually shows
 non-crystallinity or extremely low crystallinity. In particular, the
 noncrystalline structure is preferable from the viewpoint of catalytic
 performance.
 In the present invention, the solid product thus obtained is treated with
 the ether compound, titanium tetrachloride and the acyl halide compound.
 Wherein use of the organic acid halide compound decreases the amount of a
 cold xylene-soluble part which is an amorphous polymer having less
 industrial value. In addition, the polymerization activity and the bulk
 density of the polymer powder are simultaneously improved, and
 productivity are also improved.
 As the method of the treatment, it is preferable to add a mixture of the
 ether compound and titanium tetrachloride to the above-mentioned solid
 product, successively add the organic acid halide compound followed by
 treating according to the present invention.
 The amount of the ether compound used is usually about 0.008 to about 80
 mmoles per 1 g of the above-mentioned solid product, preferably about 0.04
 to about 40 mmoles, and more preferably about 0.08 to about 16 mmoles. The
 amount of titanium tetrachloride used is generally about 0.10 to about 900
 mmoles per I g of the solid product, preferably about 0.3 to about 450
 mmoles, and more preferably about 0.9 to about 270 mmoles. The amount of
 titanium tetrachloride used per 1 mole of the ether compound is usually
 about 1 to about 100 moles, preferable about 1.5 to about 75 moles, and
 more preferably about 2 to about 50 moles.
 The amount of the acyl halide compound used is usually about 0.01 to about
 1.0 mole per 1 mole of magnesium atom in the solid product, and preferably
 about 0.03 to about 0.5 moles. The use of the excess amount of the acyl
 halide compound sometimes causes the degradation of particles.
 The treatment of the above-mentioned solid product with the ether compound,
 titanium tetrachloride and the organic acid halide compound can be
 conducted by any known method capable of bringing both into contact, for
 example, by a slurry method or by mechanical pulverization means such as a
 ball mill or the like. However, a slurry method capable of bringing both
 into contact in the presence of a diluent is preferable.
 Examples of the diluent include an aliphatic hydrocarbon such as pentane,
 hexane, heptane, octane and the like, an aromatic hydrocarbon such as
 benzene, toluene, xylene and the like, an alicyclic hydrocarbon such as
 cyclohexane, cyclopentane and the like, a halogenated hydrocarbon such as
 1,2-dichloroethane, monochlorobenzene and the like. Among these, in
 particular, an aromatic hydrocarbon or a halogenated hydrocarbon is
 preferable. The amount in volume of the diluent used is generally about
 0.1 ml to about 1000 ml per 1 g of the solid product and preferably about
 1 ml to about 100 ml. The treatment temperature is generally in the range
 of about -50 to about 150.degree. C., preferably about 0 to about
 120.degree. C. and more preferably about 100 to about 120.degree. C. The
 treatment time is generally 30 minutes or more, and preferably about 1 to
 about 10 hours. After completion of the treatment, the treated solid
 product is allowed to stand for solid separation from the liquid and
 washed several times with an inert hydrocarbon solvent to obtain an acyl
 halide-treated solid.
 Then, the acyl halide-treated solid obtained is treated with either a
 mixture of the ether compound and titanium tetrachloride or a mixture of
 the ether compound, titanium tetrachloride and the ester compound.
 The treatment is preferably carried out in a state of slurry. Available
 solvents for preparation of the slurry include an aliphatic hydrocarbon
 such as pentane, hexane, heptane, octane, decane and the like, an aromatic
 hydrocarbon such as toluene, xylene and the like, an alicyclic hydrocarbon
 such as cyclohexane, methylcyclohexane, decalin and the like, and a
 halogenated hydrocarbon such as dichloroethane, trichloroethylene,
 monochlorobenzene, dichlorobenzene, trichlorobenzene and the like. Among
 these solvents, the halogenated hydrocarbons or the aromatic hydrocarbons
 are preferable.
 The concentration of the slurry is usually in the range of about 0.05 to
 about 0.7 (g-solid/ml-solvent) and preferably about 0.1 to about 0.5
 (g-solid/ml-solvent). The treatment temperature is generally in the range
 of about 30 to about 150.degree. C., preferably about 45 to about
 135.degree. C., and more preferably about 60 to about 120.degree. C. The
 reaction time is not specifically limited but generally about 30 minutes
 to about 6 hours is suitable.
 As the method of supplying the acyl halide-treated solid, the ether
 compound, titanium tetrachloride and an optional ester compound, any of
 either a process of adding the ether compound and titanium tetrachloride
 and the ester compound to the acyl halide-treated solid or, on the
 contrary, a process of adding the acyl halide-treated solid to a solution
 of the ether compound, titanium tetrachloride and the ester compound may
 be available.
 In the method of adding the ether compound, titanium tetrachloride and the
 optional ester compound to the acyl halide-treated solid, a method of
 adding titanium tetrachloride after addition of the ether compound and the
 ester compound, or a method of adding the ether compound, titanium
 tetrachloride and the ester compound simultaneously is preferable. In
 particular, the method of adding a mixture of the ether compound, titanium
 tetrachloride and the optional ester compound previously prepared to the
 acyl halide-treated solid, is preferable.
 Treatment of the acyl halide-treated solid with either a mixture of the
 ether compound and titanium tetrachloride or the treatment of a mixture of
 the ester compound, the ether compound and titanium tetrachloride may be
 carried out once or more repeatedly. It is preferable to repeat said
 treatment at least two times from the viewpoint of catalytic activity and
 stereoregularity.
 The amount of the ether compound used is usually about 0.1 to about 100
 moles per 1 mole of the titanium atom contained in the organic acid
 halide-treated solid, preferably about 0.5 to about 50 moles, and more
 preferable about 1 to about 20 moles. The amount of titanium tetrachloride
 used is usually about 1 to about 1000 moles per 1 mole of the titanium
 atom contained in the organic acid halide-treated solid, preferably about
 3 to about 500 moles, and more preferably about 10 to about 300 moles. The
 amount of titanium tetrachloride added per 1 mole of the ether compound is
 generally about I to about 100 moles, preferably about 1.5 to about 75
 moles, and more preferably about 2 to about 50 moles.
 When the ester compound is used, the amount of the ester compound used is
 usually 30 moles or less per 1 mole of the titanium atom contained in the
 acyl halide-treated solid, preferably 15 moles or less, and more
 preferably 5 moles or less.
 The solid catalyst component (A) obtained by the above-mentioned method is
 separated from the liquid and then washed several times with an inert
 hydrocarbon solvent such as hexane, heptane or the like to be used for
 polymerization. It is preferable from the viewpoint of the catalytic
 activity and stereoregularity to use the solid catalyst component for
 polymerization after washing the solid catalyst component separated from
 the liquid, once or more with a large amount of a halogenated hydrocarbon
 solvent such as monochlorobenzene or the like, or an aromatic hydrocarbon
 solvent such as toluene or the like, and subsequently several times with
 an aliphatic hydrocarbon solvent such as hexane or the like, at a
 temperature of 50 to 120.degree. C.
 A factor N in the particle size distribution function of Rosin-Rammler is
 usually known as an index representing the degree of particle size
 distribution of solid particles (refer to Rosin, P. and E. Rammler: J.
 Inst. Fuel, 7, p29(1933) and Handbook of Chemical Engineering, 3rd. ed.
 pp. 361-362, published by Maruzen Ltd.).
EQU R(Dp)=100 exp{-(Dp/De).sup.N }
 wherein R(Dp) represents a residual cumulative percentage distribution, and
 indicates a ratio of a cumulative amount of a particles-group larger than
 a particle diameter, Dp, to the total amount as a residual cumulative
 curve against the particle diameter, and De represents a particle diameter
 at R(Dp)=36.8%.
 The larger N tends to narrow the particle size distribution. The solid
 catalyst component of the large N has a narrow particle size distribution
 and the polymer obtained has a high bulk density and thereby, is favorable
 in industry.
 The solid catalyst component of the present invention obtained as described
 above is generally 3.0 or more in terms of the value of constant, N, in
 the particle size distribution function of Rosin-Rammler, and the particle
 size distribution is narrow. As the solid catalyst component of the
 present invention, the value of N is preferably 3.0 or more, more
 preferably about 3.2 or more, and most preferably about 3.4 or more.
 (g) Organoaluminum Compound
 The organoaluminum compound (B) used the present invention has at least one
 aluminum-carbon bond in its molecule. Typical examples thereof are
 indicated by the general formulae described below:
EQU R.sup.11.sub..gamma. AlY.sub.3-.gamma. ;
 and
EQU R.sup.12 R.sup.13 Al--O--AlR.sup.14 R.sup.15
 (wherein each of R.sup.11 to R.sup.15 represents a hydrocarbon group having
 1 to 20 carbon atoms, Y represents a halogen atom, a hydrogen atom, or an
 alkoxy group having 1 to 20 carbon atoms, and .gamma. is a number
 satisfying the equation of 2.ltoreq..gamma..ltoreq.3).
 Specific examples of the organoaluminum compound include trialkylaluminums
 such as triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum and the
 like, dialkylaluminum hydrides such as diethylaluminum hydride,
 diisobutylaluminum hydride and the like, dialkylaluminum halides such as
 diethylaluminum chloride and the like, mixtures of a trialkylaluminum and
 a dialkylaluminum halide such as a mixture of triethylaluminum and
 diethylaluminum chloride and the like, and alkylalumoxanes such as
 tetraethyldialumoxane, tetra-n-butyldialumoxane and the like.
 Among these organoaluminum compounds, a trialkylaluminum, a mixture of a
 trialkylaluminum and a dialkylaluminum halide and an alkylalumoxanes are
 preferable. In particular, triethylaluminum, triisobutylaluminum, a
 mixture of triethylaluminum and diethylaluminum chloride, and
 tetraethyldialumoxane are preferable.
 The amount of the organoaluminum compound used can be usually selected in
 the wide range of about 0.5 to about 1000 moles per 1 mole of the titanium
 atom in the solid catalyst component (A), but is preferably in the range
 of about 1 to about 600 moles in particular.
 (h) Electron-donative Compound
 Examples of the electron-donative compound (C) used during polymerization
 in the present invention include oxygen-containing electron donors such as
 alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic
 acids or inorganic acids, ethers, acid amides, acid anhydrides and the
 like, and nitrogen-containing electron donors such as ammonias, amines,
 nitrites, isocyanates and the like. Among these electron donors, esters of
 an inorganic acid and ethers are preferably used.
 The esters of an inorganic acid include preferably silicon compounds
 represented by the general formula, R.sup.16.sub.n Si(OR.sup.17).sub.4-n
 (wherein R.sup.16 is a hydrocarbon group having 1 to 20 carbon atoms or a
 hydrogen atom, R.sup.17 is a hydrocarbon group having 1 to 20 carbon
 atoms, respective R.sup.16 and R.sup.17 may have different substituents in
 the same molecule, n is a number satisfying the equation of
 O.ltoreq.n&lt;4). Specific examples thereof include tetramethoxysilane,
 tetraethoxysilane, tetrabutoxysilane, tetraphenoxysilane,
 methyltrimethoxysilane, ethyltrimethoxysilane, n-butyltrimethoxysilane,
 isobutyltrimethoxysilane, tert-butyltrimethoxysilane,
 isopropyltrimethoxysilane, cyclohexyltrimethoxysilane,
 phenyltrimethoxysilane, vinyltrimethoxysilane, dimethyldimethoxysilane,
 diethyldimethoxysilane, di-n-propyldimethoxysilane,
 n-propylmethyldimethoxysilane, diisopropyldimethoxysilane,
 di-n-butyldimethoxysilane, diisobutyldimethoxysilane,
 di-tert-butyldimethoxysilane, n-butylmethyldimethoxysilane,
 n-butylethyldimethoxysilane, tert-butylmethyldimethoxysilane,
 isobutylisopropyldimethoxysilane, tert-butylisopropyldimethoxysilane,
 n-hexylmethyldimethoxysilane, n-hexylethyldimethoxysilane,
 n-dodecylmethyldimethoxysilane, dicyclopentyldimethoxysilane,
 cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxysilane,
 cyclopentylisopropyldimethoxysilane, cyclopentylisobutyldimethoxysilane,
 cyclopentyl-tert-butyldimethoxysilane, dicyclohexyldimethoxysilane,
 cyclohexylmethyldimethoxysilane, cyclohexylethyldimethoxysilane,
 cyclophexylisopropyldimethoxysilane, cyclohexylisobutyldimethoxysilane,
 cyclohexyl-tert-butyldimethoxysilane,
 cyclohexylcyclopentyldimethoxysilane, cyclohexylphenyldimethoxysilane,
 diphenyldimethoxysilane, phenylmethyldimethoxysilane,
 phenylisopropyldimethoxysilane, phenylisobutyldimethoxysilane,
 phenyl-tert-butyldimethoxysilane, phenylcyclopentyldimethoxysilane,
 vinylmethyldimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane,
 n-butyltriethoxysilane, isobutyltriethoxysilane,
 tert-butyltriethoxysilane, isopropyltriethoxysilane,
 cyclohexyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane,
 dimethyldiethoxysilane, diethyldiethoxysilane, di-n-propyldiethoxysilane,
 n-propylmethyldiethoxysilane, diisopropyldiethoxysilane,
 di-n-butyldiethoxysilane, diisobutyldiethoxysilane,
 di-tert-butyldiethoxysilane, n-butylmethyldiethoxysilane,
 n-butylethyldiethoxysilane, tert-butylmethyldiethoxysilane,
 n-hexylmethyldiethoxysilane, n-hexylethyldiethoxysilane,
 n-dodecylmethyldiethoxysilane, dicyclopentyldiethoxysilane,
 dicyclohexyldiethoxysilane, cyclohexylmethyldiethoxysilane,
 cyclohexylethyldiethoxysilane, diphenyldiethoxysilane,
 phenylmethyldiethoxysilane, vinylmethyldiethoxysilane,
 ethyltriisopropoxysilane, vinyltributoxysilane,
 phenyltri-tert-butoxysilane, 2-norbornanetrimethoxysilane,
 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane,
 trimethylphenoxysilane, methyltriallyloxysilane and the like.
 The ethers include preferably di-alkyl ethers or diethers represented by
 the general formula:
 ##STR1##
 (wherein each of R.sup.18 to R.sup.21 represents a linear or branched alkyl
 group having 1 to 20 carbon atoms or an alicyclic hydrocarbon, aryl or
 aralkyl group having up to 20 carbon atoms, and R.sup.18 or R.sup.19 may
 be a hydrogen atom). Specific examples of the ether include diethyl ether,
 di-n-propyl 20 ether, diisopropyl ether, di-n-butyl ether, di-n-amyl
 ether, diisoamyl ether, dineopentyl ether, di-n-hexyl ether, di-n-octyl
 ether, methyl-n-butyl ether, methylisoamyl ether, ethylisobutyl ether,
 2,2-diisobutyl-1,3-dimethoxypropane,
 2-isopropyl-2-isoamyl-1,3-dimethoxypropane,
 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane,
 2-isopropyl-2-3,7-dimethyl-n-octyl-1,3-dimethoxypropane,
 2,2-diisopropyl-1,3-dimethoxypropane,
 2-isopropyl-2-cyclohexylmethyl-1,3-dimethoxypropane,
 2,2-dicyclohexyl-1,3-dimethoxypropane,
 2-isopropyl-2-isobutyl-1,3-dimethoxypropane,
 2,2-diisopropyl-1,3-dimethoxypropane,
 2,2-di-n-propyl-1,3-dimethoxypropane,
 2-isopropyl-2-cyclohexyl-1,3-dimethoxypropane,
 2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-
 1,3-dimethoxypropane, 2- n-heptyl-2-n-amyl-1,3-dimethoxypropane and the
 like.
 Among these electron-donative compounds, organosilicon compounds
 represented by the general formula of R.sup.22 R.sup.23
 Si(OR.sup.24).sub.2 are preferably used in particular. Wherein in the
 general formula, R.sup.22 is a hydrocarbon group having 3 to 20 carbon
 atoms in which the carbon atom adjacent to Si is secondary or tertiary.
 Specific examples of R.sup.22 include branched alkyl groups such as an
 isopropyl group, sec-butyl group, tert-butyl group, tert-amyl group and
 the like, cycloalkyl groups such as a cyclopentyl group, cyclohexyl group
 and the like, cycloalkenyl groups such as cyclopentenyl group and the
 like, aryl groups such as a phenyl group, tolyl group and the like, etc.
 Further, wherein R.sup.23 is a hydrocarbon group having 1 to 20 carbon
 atoms, and specific examples of R.sup.23 include linear alkyl groups such
 as a methyl group, ethyl group, n-propyl group, n-butyl group, n-amyl
 group and the like, branched alkyl groups such as an isopropyl group,
 sec-butyl group, tert-butyl group, tert-amyl group and the like,
 cycloalkyl groups such as a cyclopentyl group, cyclohexyl group and the
 like, cycloalkenyl groups such as a cyclopentenyl group and the like, aryl
 groups such as a phenyl group, tolyl group and the like, etc. Further,
 wherein R.sup.24 is a hydrocarbon group having 1 to 20 carbon atoms and
 preferably a hydrocarbon group having 1 to 5 carbon atoms.
 Specific examples of the organosilicon compound used as such
 electron-donative compound include diisopropyldimethoxysilane,
 diisobutyldimethoxysilane, di-tert-butyldimethoxysilane,
 tert-butylmethyldimethoxysilane, tert-butylethyldimethoxysilane,
 tert-butyl-n-propyldimethoxysilane, tert-butyl-n-butyldimethoxysilane,
 tert-amylmethyldimethoxysilane, tert-amylethyldimethoxysilane,
 tert-amyl-n-propyldimethoxysilane, tert-amyl-n-butyldimethoxysilane,
 isobutylisopropyldimethoxysilane, tert-butylisopropyldimethoxysilane,
 dicyclopentyldimethoxysilane, cyclopentylisopropyldimethoxysilane,
 cyclopentyl-tert-butyldimethoxysilane,
 cyclopentyl-tert-butyldimethoxysilane, dicyclohexyldimethoxysilane,
 cyclohexylmethyldimethoxysilane, cyclohexylethyldimethoxysilane,
 cyclohexylisopropyldimethoxysilane, cyclohexylisobutyldimethoxysilane,
 cyclohexyl-tert-butyldimethoxysilane,
 cyclohexylcyclopentyldimethoxysilane, cyclohexylphenyldimethoxysilane,
 diphenyldimethoxysilane, phenylmethyldimethoxysilane,
 phenylisopropyldimethoxysilane, phenylisobutyldimethoxysilane,
 phenyl-tert-butyldimethoxysilane, phenylcyclopentyldimethoxysilane,
 diisopropyldiethoxysilane, diisobutyldiethoxysilane,
 di-tert-butyldiethoxysilane, tert-butylmethyldiethoxysilane,
 tert-butylethyldiethoxysilane, tert-butyl-n-propyldiethoxysilane,
 tert-butyl-butyldiethoxysilane, tert-amylmethyldiethoxysilane,
 tert-amylethyldiethoxysilane, tert-amyl-n-propyldiethoxysilane,
 tert-amyl-butyldiethoxysilane, dicyclopentyldiethoxysilane,
 dicyclohexyldiethoxysilane, cyclohexylmethyldiethoxysilane,
 cyclohexylethyldiethoxysilane, diphenyldiethoxysilane,
 phenylmethyldiethoxysilane, 2-norbornanmethyldimethoxysilane and the like.
 (i) Polymerization of Olefin
 .alpha.-olefins applicable for the present invention are .alpha.-olefins
 having 3 or more carbon atoms, and preferably .alpha.-olefins having 3 to
 10 carbon atoms. Specific examples thereof include linear monoolefins such
 as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene
 and the like, branched monoolefins such as 3-methyl-1-butene,
 3-methyl-1-pentene, 4-methyl-1-pentene and the like, vinylcyclohexane and
 the like. These .alpha.-olefins may be used alone or in combinations of 2
 or more kinds thereof.
 Particularly, the catalyst of the present invention is preferably
 applicable to homopolymerization of propylene or 1-butene, or
 copolymerization of an olefin mixture including propylene or 1-butene as a
 main component, and more preferably to homopolymerization of propylene and
 copolymerization of an olefin mixture including propylene as a main
 component. And, a mixture of ethylene and two or more olefins selected
 from the above-mentioned .alpha.-olefins can be applied for the
 copolymerization in the present invention. Further, a compound having a
 plurality of unsaturated bond such as a conjugated diene and a
 non-conjugated diene, can be also used in the copolymerization.
 Hetero-block copolymerization, wherein polymerization is carried out in
 two or more stages, can be easily conducted.
 The charging of the respective catalyst components to a polymerization
 vessel is not particularly restricted except that they should be supplied
 under a water-free condition in an inert gas such as nitrogen, argon or
 the like.
 The solid catalyst component (A), the organoaluminum compound (B) and the
 electron-donative compound (C) may be charged independently, or
 alternatively any two of them may be mixed together prior to being
 charged.
 In the present invention, polymerization of the olefin can be carried out
 in the presence of the fore-mentioned catalyst. The preliminary
 polymerization described below may be carried out prior to such a
 polymerization (main polymerization).
 The preliminary polymerization is carried out by charging a small amount of
 an olefin in the presence of the solid catalyst component (A) and the
 organoaluminum compound (B), and is preferably carried out in the state of
 a slurry. The solvent used for preparation of the slurry includes an inert
 hydrocarbon such as propane, butane, isobutane, pentane, isopentane,
 hexane, heptane, octane, cyclohexane, benzene, toluene and the like.
 Further, a part or the whole of the inert hydrocarbon solvent used for
 preparation of a slurry may be replaced with a liquid olefin.
 The amount of the organoaluminum compound used for the preliminary
 polymerization can be usually selected in a wide range of about 0.5 to
 about 700 moles per 1 mole of the titanium atom contained in the solid
 catalyst component, preferably about 0.8 to about 500 moles and more
 preferably about 1 to about 200 moles.
 The amount of the olefin to be preliminarily polymerized is usually about
 0.01 to about 1000 g per 1 g of the solid catalyst component, preferably
 about 0.05 to about 500 g and more preferably about 0.1 to about 200 g.
 The concentration of slurry for the preliminary polymerization is
 preferably about 1 to about 500 g(solid catalyst component)/liter(solvent)
 and more preferably about 3 to about 300 g(solid catalyst
 component)/liter(solvent). The temperature of preliminary polymerization
 is preferably about -20 to about 100.degree. C. and more preferably about
 0 to about 80.degree. C. The partial pressure of the olefin in the gas
 phase during the preliminary polymerization is preferably about 0.01 to
 about 20 kg/cm.sup.2 and more preferably about 0.1 to about 10
 kg/cm.sup.2. However, this is not applied to the olefin which is liquid at
 a temperature under a pressure in the preliminary polymerization. The
 preliminary polymerization time is not specifically restricted, but is
 usually about 2 minutes to about 15 hours.
 When the preliminary polymerization is carried out, as methods for charging
 the solid catalyst component (A), the organoaluminum compound (B) and the
 olefin, either of a method in which the olefin is fed after the solid
 catalyst component (A) has been contacted with the organoaluminum compound
 (B) or a method in which the organoaluminum compound (B) is fed after the
 solid catalyst component (A) has been contacted with the olefin may be
 used.
 As a feeding method of the olefin, either a method of feeding the olefin in
 sequence while keeping the pressure so that the interior of a
 polymerization vessel becomes a predetermined pressure, or a method
 wherein the whole of the predetermined amount of the olefin is fed
 initially, may be used. A chain transfer agent such as hydrogen or the
 like, can be added in order to adjust the molecular weight of the polymer
 obtained.
 The electron-donative compound (C) may coexist, if required, when a small
 amount of the olefin is preliminarily. polymerized by the solid catalyst
 component (A) in the presence of the organoaluminum compound (B). A part
 or the whole of the electron-donative compound (C) described above may be
 used as the electron-donative compound here.
 The amount of (C) used is usually about 0.01 to about 400 moles per 1 mole
 of the titanium atom contained in the solid catalyst component (A),
 preferably about 0.02 to about 200 moles, and more preferably about 0.03
 to about 100, and is usually about 0.003 to about 5 moles per the
 organoaluminum compound (B), preferably about 0.005 to about 3 moles, and
 more preferably about 0.01 to about 2 moles. The method of feeding the
 electron-donative compound (C) for the preliminary polymerization is not
 specifically restricted. It may be separately fed from the organoaluminum
 compound (B) or may be fed after previously being contacted with the
 organoaluminum compound. Further, the olefin used in the preliminary
 polymerization may be the same as or different from the olefin to be used
 in the main polymerization.
 After carrying out the preliminary polymerization described above, or
 without the preliminary polymerization, the main polymerization of the
 .alpha.-olefin can be carried out in the presence of the catalyst for
 .alpha.-olefin polymerization composed of the fore-mentioned solid
 catalyst component (A), the organoaluminum compound (B) and the
 electron-donative compound (C).
 The amount of the organoaluminum compound used for main polymerization can
 be usually selected in a wide range of about 1 to about 1000 moles per 1
 mole of the titanium atom in the solid catalyst component (A), and
 preferably about 5 to about 600 moles in particular.
 The electron-donative compound (C) used in the main polymerization is
 usually about 0.1 to about 2000 moles per 1 mole of the titanium atom
 contained in the solid catalyst component (A), preferably about 0.3 to
 about 1000 moles, and more preferably about 0.5 to about 800 moles, and is
 usually about 0.001 to about 5 moles per the organoaluminum compound,
 preferably about 0.005 to about 3 moles, and more preferably about 0.01 to
 about 1 mole.
 The main polymerization can be usually carried out at a temperature within
 a range of about -30 to about 300.degree. C. and preferably about 20 to
 about 180.degree. C. The polymerization pressure is not specifically
 restricted, but a pressure of about normal pressure to about 100
 kg/cm.sup.2 and preferably about 2 to about 50 kg/cm.sup.2 is usually
 adopted from the industrial and economical viewpoints. The polymerization
 can be carried out batchwise or continuously. Slurry polymerization or
 solution polymerization using an inert hydrocarbon solvent such as
 propane, butane, isobutane, pentane, hexane, heptane, octane or the like,
 bulk polymerization using, as a medium, an olefin which is liquid at the
 polymerization temperature, or gas phase polymerization, is applicable.
 In the main polymerization, a chain transfer agent such as hydrogen or the
 like can be added in order to adjust the molecular weight of the polymer
 produced.
 EXAMPLE
 The present invention will be illustrated in more detail by Examples and
 Comparative Examples below, but is not particularly limited thereto.
 Evaluation methods for the various properties of polymers in the Examples
 are as follows.
 (1) Xylene-soluble Portion at 20.degree. C. (hereinafter, referred to as
 "CXS"):
 After dissolving 1 g of polymer powders in 200 ml of boiled xylene, the
 solution is cooled to 50.degree. C., further cooled in iced water with
 stirring to 20.degree. C., is allowed to stand at 20.degree. C. for 3
 hours, and a polymer precipitated is filtered out. The filtrate is
 evaporated for removal of the xylene. The residue is dried under reduced
 pressure at 60.degree. C. to recover the polymer soluble in 20.degree. C.
 xylene and weigh it. The weight percentage of the polymer soluble in
 xylene at 20.degree. C. to the whole polymer is calculated (% by weight).
 The smaller CXS indicates less amorphous polymer and higher
 stereoregularity.
 (2) Intrinsic Viscosity (hereinafter, referred to as [.eta.]):
 The Intrinsic viscosity was measured in tetralin solvent at 135.degree. C.
 with an Ubbelohde viscometer.
 (3) N in Rosin-Rammler Function:
 The particle size distribution was measured with an ultra centrifugal-type
 automatic particle size distribution analyzer CAPA-700 (manufactured by
 Horiba Ltd.). Then, the data obtained were applied to the Rosin-Rammler
 function (refer to P. Rosin and E. Rammler: J. Inst. Fuel, 7, p29(1933)
 and Handbook of Chemical Engineering, 3rd. ed. pp. 361-362, published by
 Maruzen Ltd.) described below, to determine the particle size
 distribution:
EQU R(Dp)=100exp{-(Dp/De).sup.N }
 wherein R(Dp) is a distribution of residual ratio and is shown as a
 residual ratio curve, which shows the ratio of the total weight of larger
 particles than a predetermined particle diameter Dp to the whole weight
 plotted against the particle diameter, and De represents a particle
 diameter at R(Dp)=36.8%. A larger N tends to narrow the distribution. A
 solid catalyst component having a large N has a narrow particle size
 distribution, and a polymer obtained has a high bulk density and is
 preferable in industry.
 Example 1
 (a) Synthesis of Solid Product
 The atmosphere in a 500 ml-flask equipped with a stirrer and a dropping
 funnel was replaced with nitrogen, and 270 ml of hexane, 2.5 ml (2.5 g:
 7.34 mmol) of diisobutyl phthalate, and 73.5 ml (68.6 g: 329 mmol) of
 tetraethoxysilane were charged in the flask to obtain a homogeneous
 solution. Then, 170 ml of a di-n-butyl ether solution of n-butylmagnesium
 chloride (manufactured by Yukigosei Yakuhin K.K., concentration of
 n-butylmagnesium chloride: 2.1 mmol/ml) was slowly added dropwise from the
 dropping funnel over 3 hours, while the temperature in the flask was kept
 at 5.degree. C. After the dropwise addition, the solution was further
 stirred at 5.degree. C. for one hour and at room temperature for an
 additional one hour. Then, the resulted mixture was subjected to
 solid-liquid separation to obtain a solid. The solid was washed three
 times with 185 ml of toluene to obtain a solid product. Then, 205 ml of
 toluene was added to the solid product to prepare a slurry having a
 concentration of 0.142 g/ml. A part of the slurry was sampled, and the
 solid product in the slurry was subjected to composition analysis. No
 phthalic acid ester was detected, and the solid product contained 33.4% by
 weight of ethoxy group and 0.54% by weight of butoxy group.
 (b) Synthesis of Solid Catalyst Component
 The atmosphere in a 100 ml-flask equipped with a stirrer, a dropping funnel
 and a thermometer was replaced with nitrogen. After 55.1 ml of the slurry
 containing the solid product obtained in the above-mentioned (a) was
 charged, the slurry was dried. 19.6 ml of toluene was added, a mixture of
 0.78 ml (6.3 mmol) of di-n-butyl ether and 15.7 ml (0.143 mole) of
 titanium tetrachloride was added, and subsequently 1.57 ml (10.9 mmol:
 0.20 ml/lg of solid product) of phthaloyl chloride was added to the
 slurry. The slurry was heated to 115.degree. C. and stirred for three
 hours. After completion, the reaction mixture was subjected to
 solid-liquid separation at the same temperature to obtain a solid. The
 obtained solid was washed twice with 39 ml of toluene at the same
 temperature. Then, a mixture of 9.8 ml of toluene, 0.44 ml (1.64 mmol) of
 diisobutyl phthalate, 0.78 ml (6.3 mmol) of di-n-butyl ether and 7.8 ml
 (0.071 mole) of titanium tetrachloride was added to the solid for
 treatment, and the solid was treated for one hour at 115.degree. C. After
 completion of the treatment, the resulted mixture was subjected to
 solid-liquid separation at the same temperature to obtain a first treated
 solid. The treated solid was washed twice with 39 ml of toluene at the
 same temperature. Then, a mixture of 9.8 ml of toluene, 0.78 ml (6.3 mmol)
 of di-n-butyl ether and 7.8 ml (0.071 mole) of titanium tetrachloride was
 added to the first treated solid, and the solid was treated for one-hour
 at 115.degree. C. Then, the resulting mixture was subjected to
 solid-liquid separation at the same temperature to obtain a second treated
 solid, That was separated from the slurry at the same temperature. The
 second treated solid was washed twice with 39 ml of toluene at the same
 temperature. Then, a mixture of 9.8 ml of toluene, 0.78 ml (6.3 mmol) of
 di-n-butyl ether and 7.8 ml (0.071 mole) of titanium tetrachloride was
 added to the second treated solid, and the resulted mixture was treated
 for one-hour at 115.degree. C. After completion of the treatment, the
 resulted mixture was subjected to solid-liquid separation at the same
 temperature to obtain a third treated solid. The third treated solid was
 washed three times with 39 ml of toluene at the same temperature, washed
 three times with 39 ml of hexane, and further dried under reduced pressure
 to obtain 6.90 g of a solid catalyst component.
 The solid catalyst component contained 1.58% by weight of titanium atom,
 8.81% by weight of phthalate, 0.1% by weight of ethoxy group and 0.1% by
 weight of butoxy group.
 (c) Polymerization of Propylene
 The atmosphere of a stirring-type stainless steel autoclave of 3 liter was
 replaced with argon, 2.6 mmol of triethylaluminum, 0.26 mmol of
 cyclohexylethyldimethoxysilane and 6.6 mg of the solid catalyst component
 synthesized in (b) were charged into the autoclave, and hydrogen
 corresponding to a partial pressure of 0.33 kg/cm.sup.2 was introduced
 thereto. Then, after charging 780 g of liquid propylene, the autoclave was
 heated to a temperature of 80.degree. C. and polymerization was carried
 out at 80.degree. C. for one hour. After completion of the polymerization,
 the unreacted monomer was purged out. The obtained polymer was dried under
 reduced pressure at 60.degree. C. for two hours, so as to obtain 407 g of
 polypropylene powders.
 The yield (hereinafter, referred to as PP/Cat) of polypropylene(g) per 1 g
 of the solid catalyst component was 61700 (g/g). The ratio of a 20.degree.
 C. xylene-soluble component contained in the whole polymer (CXS) was
 0.37(% by weight), the intrinsic viscosity of the polymer [.eta.] was
 2.10, and the bulk density was 0.385 g/ml. Conditions and results of
 polymerization are shown in Table 1.
 Comparative Example 1
 (a) Synthesis of Reduced Solid Product
 The reaction was carried out in the same manner as in (a) of Example 1
 except that the amounts of reagents used were 2.5 ml (2.6 g: 9.3 mmol) of
 diisobutyl phthalate, 78.0 ml (72.9 g: 349.7 mmol) of tetraethoxysilane,
 and 181 ml of the solution of n-butylmagnesium chloride. The solid product
 obtained separated from the solution was washed three times with 300 ml of
 toluene, and 155 ml of toluene was then added to the washed solid product
 to form a slurry of a concentration of 0.172 g/ml.
 A part of the solid product slurry was sampled, and composition analysis of
 the solid product was carried out. No phthalic acid ester was detected and
 the solid product contained 32.6% by weight of ethoxy group and 0.42% by
 weight of butoxy group.
 (b) Synthesis of Solid Catalyst Component
 After the atmosphere in a 200 ml-flask equipped with a stirrer, a dropping
 funnel and a thermometer, was replaced with argon, 29 ml of the solid
 product-containing slurry obtained in the above-mentioned (a) was charged
 into the flask, 3.35 ml (12.5 mmol) of diisobutyl phthalate was added, and
 the reaction was carried out at 105.degree. C. for 30 minutes. After the
 reaction, a reaction mixture was subjected to solid-liquid separation to
 obtain a ester-treated solid, and the ester-treated solid was washed twice
 with 25 ml of toluene.
 Then, a mixture of 7.0 ml of toluene, 0.28 ml (1.1 mmol) of diisobutyl
 phthalate, 0.5 ml (4.0 mmol) of di-n-butyl ether and 8.0 ml (73.0 mmol) of
 titanium tetrachloride was added in the flask and the mixture was treated
 at 105.degree. C. for 3 hours. After completion of the treatment, the
 resulting mixture was subjected to solid-liquid separation to obtain a
 treated solid. The treated solid was washed twice with 25 ml of toluene at
 the same temperature. Then, a mixture of 7.0 ml of toluene, 0.5 ml (4.0
 mmol) of di-n-butyl ether, and 4.0 ml (36.5 mmol) of titanium
 tetrachloride was added to the treated solid, and the resulting mixture
 was treated at 105.degree. C. for 1 hour. After completion of the
 treatment, the resulting mixture was subjected to solid-liquid separation
 to obtain a second treated solid. The second treated solid was washed 3
 times with 25 ml of toluene at the same temperature, successively three
 times with 25 ml of hexane, and dried under reduced pressure to obtain 4.6
 g of a solid catalyst component. The solid catalyst component contained
 1.67% by weight of titanium atom, 9.10% by weight of a phthalic acid
 ester, 0.65% by weight of ethoxy group, and 0.14% by weight of butoxy
 group.
 (c) Polymerization of Propylene
 Propylene was polymerized in the same manner as in the polymerization of
 propylene in (c) of Example 1, except that 4.0 mg of the solid catalyst
 component obtained in the above-mentioned (b) was used.
 As the results of polymerization, the PP/Cat was lower being 42200 (g/g),
 than that in Example 1, and the stereoregularity of the polymer obtained
 was lower being 0.74% by weight in terms of CXS than that of Example 1.
 The bulk density was 0.395 g/ml, and [.eta.] was 1.82 (dl/g). Conditions
 and results of polymerization are shown in Table 1.
 Comparative Example 2
 (a) Synthesis of Solid Catalyst Component
 After the atmosphere in a 100 ml flask equipped with a stirrer, a dropping
 funnel and a thermometer was replaced with argon, 50 ml of the solid
 product-containing slurry prepared in (a) of Example 1 was charged
 therein, 8.8 ml of the supernatant liquid was taken from the slurry, and
 1.42 ml (9.86 mmol) of phthaloyl chloride was added, and the reaction was
 carried out at 110.degree. C. for 30 minutes. After the reaction, the
 resulted mixture was subjected to solid-liquid separation to obtain a
 treated solid, and the treated solid was washed twice with 36 ml of
 toluene. Then, a mixture of 9.0 ml of toluene, 0.40 ml (1.5 mmol) of
 diisobutyl phthalate, 0.71 ml (5.7 mmol) of di-n-butyl ether and 14.2 ml
 (0.129 mol) of titanium tetrachloride was added to the flask, and the
 reaction was carried out at 115.degree. C. for three hours. After
 completion of the reaction, the resulting mixture of solids was subjected
 to solid-liquid separation at the same temperature to obtain a first
 treated solid, and the first treated solid was washed twice with 36 ml of
 toluene at the same temperature. Then, a mixture of 9 ml of toluene, 0.71
 ml (5.7 mmol) of di-n-butyl ether and 7.1 ml (0.065 mol) of titanium
 tetrachloride was added to the first treated solid and the reaction was
 carried out at 115.degree. C. for one hour. After completion of the
 reaction, the reaction mixture was subjected to solid-liquid separation at
 the same temperature. The separated solid was washed three times with 36
 ml of toluene at the same temperature, subsequently three times with 36 ml
 of hexane, and further dried under reduced pressure to obtain 5.74 g of a
 solid catalyst component.
 The solid catalyst component contained 0.99% by weight of titanium atom,
 7.30% by weight of a phthalic acid ester, 1.95% by weight of ethoxy group,
 and 0.20% by weight of butoxy group.
 (b) Polymerization of Propylene
 Propylene was polymerized in the same manner as in the polymerization of
 propylene in (c) of Example 1, except that 4.9 mg of the solid catalyst
 component obtained in the above-mentioned (a) was used.
 The results of polymerization shows a low polymerization activity of PP/Cat
 of 5820 (g/g) and a low stereoregularity of 1.2% by weight in terms of
 CXS. Further, the bulk density was 0.362 g/ml, and [.eta.] was 1.72
 (dl/g). The conditions and results of the polymerization are shown in
 Table 1.
 Comparative Example 3
 (a) Synthesis of Solid Component
 The atmosphere in a 500 ml flask equipped with a stirrer and a dropping
 funnel was replaced with nitrogen, and 130 ml of di-n-butyl ether, 70.7 ml
 of a di-n-butyl ether solution of n-butylmagnesium chloride (manufactured
 by Yukigosei Yakuhin K.K., concentration of n-butylmagnesium chloride: 2.1
 mmol/ml) were charged therein to obtain a homogeneous solution. Then, a
 mixed solution of 60 ml of a di-n-butyl ether solution and 8.7 ml of
 ethanol was slowly added dropwise from the dropping funnel over 1.25
 hours, while the temperature in the flask was kept at 5.degree. C. After
 completion of the dropwise addition, the solution was further stirred at
 5.degree. C. for 30 minutes, successively heated to 75.degree. C., and
 stirred at the same temperature for 30 minutes. Then, the resulted mixture
 was left alone, a produced solid was separated from the mixture, washed
 twice with 200 ml of hexane, and then dried under vacuum to obtain 17.35 g
 of a solid product.
 (b) Synthesis of Solid Catalyst Component
 The atmosphere in a 300 ml flask equipped with a stirrer, a dropping funnel
 and a thermometer was replaced with nitrogen. After 10.32 g of the solid
 product obtained in the above-mentioned (a) was charged, 62.0 ml of
 toluene and 41.3 ml (0.380 mol) of titanium tetrachloride were charged and
 the mixture was heated to 70.degree. C. Then, 1.55 ml (4.55 mmol) of
 tetra-n-butoxy titanium and 2.06 ml (14.3 mmol: 0.20 ml/1 g of solid
 product) of phthaloyl chloride were added, and the mixture was heated to
 115.degree. C. and stirred for 2 hours as it was. After completion of the
 reaction, the supernatant liquid was taken out at the same temperature by
 a decantation method, and then the residue was washed twice with 200 ml of
 toluene at the same temperature by the same method. Then, a mixture of
 62.0 ml of toluene and 41.3 ml (0.377 mol) of titanium tetrachloride was
 added, and the mixture was treated at 115.degree. C. for two hours. After
 completion of the reaction, the supernatant liquid was taken out at the
 same temperature by a decantation method, and the residue was washed twice
 with 200 ml of toluene at the same temperature by the same method. Then,
 62.0 ml of toluene and 41.3 ml (0.377 mol) of titanium tetrachloride were
 added, and the mixture was treated at 115.degree. C. for two hours. After
 completion of the reaction, the supernatant liquid was taken out at the
 same temperature by a decantation method, the residue was washed twice
 with 200 ml of toluene at the same temperature by the same method, washed
 ten times with 200 ml of hexane and dried under reduced pressure to obtain
 8.19 g of a solid catalyst component.
 The solid catalyst component contained 1.32% by weight of titanium atom,
 4.19% by weight of a phthalic acid ester, and 0.1% by weight of ethoxy
 group.
 (c) Polymerization of Propylene
 Propylene was polymerized in the same manner as in the polymerization of
 propylene in (c) of Example 1, except that the solid catalyst component
 obtained in the above-mentioned (b) was used.
 As the result of polymerization, the PP/Cat was low, being 46600 (g/g). The
 CXS of the polymer was 0.87 (% by weight), the bulk density was 0.314
 g/ml, and [.eta.] was 2.14(dl/g). Conditions and results of polymerization
 are shown in Table 1.
 TABLE 1
 Polymerization results
 Electron Bulk
 donative PP/Cat CXS [.eta.] Density
 N compound (g/g) (wt %) (dl/g) (g/ml)
 Example 1 3.54 cHEDMS 61700 0.37 2.10 0.385
 Comparative 2.20 cHEDMS 42200 0.74 1.82 0.395
 Example 1
 Comparative 4.64 cHEDMS 5820 1.2 1.72 0.362
 Example 2
 Comparative 1.51 cHEDMS 46600 0.87 2.14 0.314
 Example 3
 cHEDMS: cyclohexylethyldimethoxysilane
 According to the present invention, a catalyst for .alpha.-olefin
 polymerization which is excellent in particle size distribution and has a
 high catalytic activity, which is enough to make the removal of catalyst
 residues and an amorphous polymer unnecessary, and stereoregularity, and a
 process for producing a highly stereoregular .alpha.-olefin polymer of
 high quality are provided.