Title of Invention | "A PROCESS FOR PREPARING A SOLID TITANIUM CATALYST COMPONENT" |
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Abstract | Disclosed is a solid titanium catalyst component for olefin polymerization, which is a solid titanium catalyst component containing titanium, magnesium and halogen as its essential ingredients and has such properties that: magnesium halide constituting the catalyst component has a microcrystalline size, as calculated from peaks of the (110) face measured by X-ray diffractometry of the magnesium halide, of 3 to 100 Å; the volume of pores having a radius of not more than 0.1 µm is not more than 0.20 cm3/g; the volume of pores having a radius of 0.1 to 7.5 µm is not less than 0.30 cm3/g; and the catalyst component has a mean particle diameter, as measured by a light transmission sedimentation method, of 0.5 to 80 µm. The solid catalyst component is capable of (co)polymerizing olefin with high polymerization activity. |
Full Text | FIELD OF THE INVENTION The present invention relates to a solid titanium catalyst component used as a catalyst component for preparing olefin (co)polymers, a process for preparing the catalyst component, an olefin polymerization catalyst containing the catalyst component and an olefin polymerization process using the catalyst. BACKGROUND OF THE INVENTION Catalysts containing titanium compounds supported on active magnesium halides have hitherto been known as those used for preparing homopolymers of α-olefins or olefin copolymers such as ethylene/α-olefin copolymers. As the olefin polymerization catalysts, those comprising a solid titanium catalyst component consisting of magnesium, titanium, halogen and an electron donor and an organometallic compound catalyst component are known. It is also known that when the solid titanium catalyst component containing magnesium, titanium, halogen and an electron donor as its essential ingredients is used in the polymerization of a-olefins of 3 or more carbon atoms, polymers of high stereoregularity can be obtained in high yields. For preparing the solid titanium catalyst component, there is known, for example, a process wherein a hydrocarbon solution of a halogen-containing magnesium compound is contacted with a liquid titanium compound to form a solid product or a process wherein a hydrocarbon solution of a magnesium halide compound and a titanium compound is prepared and then a solid product is formed in the presence of an electron donor. As described above, many proposals relating to processes for preparing solid titanium catalyst components have been made, but studies of the properties of the resulting solid titanium catalyst components have been scarcely made. Under such circumstances as mentioned above, the present inventors studied to obtain a solid titanium catalyst component by the use of which olefin (co)polymers of high stereoregularity can be obtained with high polymerization activity. As a result, they have found that an olefin polymerization catalyst, which contains a solid titanium catalyst component having a specific microcrystalline size (size of microcrystals of magnesium halide constituting the solid titanium catalyst component), a specific volume of pores having a radius of not more than 0.1 µm, a specific volume of pores having a radius of 0.1 to 7.5 µm and a specific mean catalyst particle diameter, can prepare olefin (co)polymers with high polymerization activity. Moreover, they have also found that when α-olefins of 3 or more carbon atoms are polymerized in the presence of the catalyst, olefin (co)polymers of high stereoregularity can be obtained. Based on the finding, the present invention has been accomplished. OBJECT OF THE INVENTION The present invention has been made under such circumstances as described above, and it is an object of the invention to provide a solid titanium catalyst component capable of (co)polymerizing an olefin with high polymerization activity and a process for preparing the catalyst component. It is another object of the invention to provide an olefin polymerization catalyst containing the solid titanium catalyst component and an olefin polymerization process using the catalyst. SUMMARY OF THE INVENTION The solid titanium catalyst component for olefin polymerization according to the invention is a solid titanium catalyst component containing titanium, magnesium and halogen as its essential ingredients, wherein: (1) magnesium halide constituting the catalyst component has a microcrystalline size, as calculated from peak of the (110) face measured by X-ray diffractometry of the magnesium halide, of 3 to 100 A, (2) the volume of pores having a radius of not more than 0.1µm is not more than 0..20 cm3/g, (3) the volume of pores having a radius of 0.1 to 7.5 µm is not less than 0.30 cm3/g, and (4) the catalyst component has a mean particle diameter, as measured by a light transmission sedimentation method, of 0.5 to 80 µm. It is preferable that the solid titanium catalyst component for olefin polymerization according to the invention is a solid titanium catalyst component containing titanium, magnesium and halogen as its essential ingredients, wherein: (1) magnesium halide constituting the catalyst component has a microcrystalline size, as calculated from peak of the (110) face measured by X-ray diffractometry of the magnesium halide, of 10 to 40 Å, (2) the volume of pores having a radius of not more than 0.1 µm is not more than 0.01 cm3/g, (3) the volume of pores having a radius of 0.1 to 7.5 µm is not less than 0.50 cm3/g, and (4) the catalyst component has a mean particle diameter, as measured by a light transmission sedimentation method, of 0.5 to 80 µm . The solid titanium catalyst component can be prepared by contacting a magnesium compound in the liquid state with a liquid titanium compound in the presence of a diether compound having a fluorene ring, said diether compound being represented by the following formula (i): (Formula Removed) wherein Ra and Rb may be the same as or different from each other and are each an alkyl group of 1 to 6 carbon atoms, X and Y may be the same as or different from each other and are each an alkyl group of 1 to 6 carbon atoms or a halogen atom, m is a number of 0 Further, the solid titanium catalyst component for olefin polymerization can be prepared by a process comprising the steps of: contacting a magnesium compound in the liquid state with a diether compound having a fluorene ring, said diether compound being represented by the above formula (i), and then contacting the resulting solution with a liquid titanium compound. The magnesium compound in the liquid state can be prepared by, for example, contacting a magnesium compound with a compound capable of solubilizing the magnesium compound and selected from the group consisting of alcohols, esters and ethers in a hydrocarbon solvent. The olefin polymerization catalyst according to the invention comprises: (A) the above-mentioned solid titanium catalyst component, (B) an organometallic compound catalyst component containing a metal selected from Group I to Group III of the periodic table, and (C) an electron donor. The olefin polymerization catalyst according to the invention may be a prepolymerized olefin-containing catalyst. The olefin polymerization process according to the invention comprises polymerizing or copolymerizing an olefin in the presence of the above-mentioned olefin polymerization catalyst. DETAILED DESCRIPTION OF THE INVENTION The solid titanium catalyst component for olefin polymerization, the process for preparing the catalyst component, the olefin polymerization catalyst containing the catalyst component and the olefin polymerization process using the catalyst according to the invention are described in detail hereinafter. The meaning of the term "polymerization" used herein is not limited to "homopolymerization" but may comprehend "copolymerization". Also, the meaning of the term "polymer" used herein is not limited to "homopolymer" but may comprehend "copolymer". (Solid titanium catalyst component) The solid titanium catalyst component for olefin polymerization according to the invention contains titanium, magnesium and halogen as its essential ingredients. In the solid titanium catalyst component for olefin polymerization, titanium is contained in an amount of 0.3 to 10 % by weight, preferably 0.5 to 8 % by weight, more preferably 0.8 to 6 % by weight, still more preferably 1 to 5 % by weight, magnesium is contained in an amount of 5 to 35 % by weight, preferably 8 to 30 % by weight, more preferably 10 to 28 % by weight, still more preferably 12 to 25 % by weight, and halogen is contained in an amount of 30 to 75 % by weight, preferably 35 to 75 % by weight, more preferably 38 to 72 % by weight, still more preferably 40 to 70 % by weight. It is preferable that the solid titanium catalyst component of the invention further contains an electron donor in addition to the essential ingredients of titanium, magnesium and halogen. In this case, the electron donor is desirably contained in an amount of 0.5 to 30 % by weight, preferably 1 to 27 % by weight, more preferably 3 to 25 % by weight, still more preferably 5 to 23 % by weight. The electron donor is, for example, the later-described electron donor (a). Above all, a diether compound having a fluorene ring, that is represented by the formula (i) , is preferable. The composition of the solid titanium catalyst component is determined in the following manner. The solid titanium catalyst component is sufficiently washed with a large amount of hexane and dried for not shorter than 2 hours under the conditions of 0.1 to I Torr and room temperature. Then, the solid component is measured by means of ICP (atomic absorption spectrometry), GC (gas chromatography) or the like. In the solid titanium catalyst component of the invention, the microcrystalline size of magnesium halide (microcystals) constititing the catalyst component, as calculated from peak of the (110) face measured by X-ray diffractometry of the magnesium halide, is in the range of 3 to 100 Å, preferably 5 to 80 Å, more preferably 10 to 40 Å, still more preferably 10 to 30 Å. When the microcrystalline size is much smaller than 3 Å, the particle shape of the catalyst becomes worse and the apparent bulk density of the resulting olefin (co)polymer is sometimes lowered. When the microcrystalline size is much larger than 100 Å, decrease of polymerization activity or lowering of stereoregularity of the resulting olefin (co)polymer may occur. In the solid titanium catalyst component of the invention, the volume of pores having a radius of not more than 0.1 μm is not more than 0.20 cm3/g, preferably not more than 0.15 cm3/g, more preferably not more than 0.01 cm3/g, still more preferably not more than 0.005 cm3/g; and the volume of pores having a radius of 0.1 to 7.5 μm is not less than 0.30 cm3/g, preferably not less than 0.40 cm3/g, more preferably not less than 0.45 cm3/g, still more preferably not less than 0.50 cm3/g. When the volume of pores having a radius of not more than 0.1μm is much larger than 0.20 cm3/g, decrease of polymerization activity or lowering of stereoregularity of the resulting olefin (co)polymer may occur. When the volume of pores having a radius of 0.1 to 7.5 μm is much smaller than 0.30 cm3/g, decrease of polymerization activity may occur. The mean particle diameter (volume standard) of the solid titanium catalyst component of the invention, as measured by a light transmission sedimentation method, is in the range of 0.5 to 80 μm, preferably 3 to 70 μm, more preferably 3 to 35 μm. When the mean catalyst particle diameter is much smaller than 0.5 μm, the resulting olefin (co)polymer sometimes contains a fine powder. The microcrystalline size, the volume of pores and the mean catalyst particle diameter are measured in the following ways. Microcrystalline size The microcrystalline size was determined by measuring a half-value width (FWHM) of the (110) face by means of an X-ray diffractometer (RU-300 manufactured by Rigaku Denki Co.) and applying the obtained value to the known Scherrer's formula (0.9 in the formula returns to a constant K). The samples used in the measurement of the microcrystalline size were all handled in a nitrogen atmosphere. The measurement of the microcrystalline size using the Scherrer's formula is described in detail in "Elements of X-ray Diffractometry by D.B. Cullity" (translated by Gentaro Matsumura) published by Agne Co. Volume of pores About 0.3 g of a sample for measurig pore volume was accurately weighed and introduced into a measuring cell. After the cell was degassed (to about 0.7 Pa), mercury was poured into the cell, and the cell was mounted on a device to measure the pore volume. The measuring conditions are as follows. Measuring device: Porosimeter 2000, manufactured by Carloelva Co. Measuring pressure range: about 1,000 kPa to. 190 MPa Measuring mode: pressurizing process within the above pressure range Cell volume: 15 cm3 Mean catalyst particle diameter (volume standard) Measurement of the mean catalyst particle diameter was carried out by a light transmission sedimentation method. In the measurement, an automatic particle distribution measuring device of CAPA-300 model (manufactured by Horiba Co.) was used, and the main particle deameter was calculated by applying the obtained values to the known Stokes' formula as shown below. A mixed liquid of decalin and triolein (decalin/triolein = 4/1 by weight) was used as a dispersant. (Formula Removed) D: particle diameter (cm) ηo: viscosity coefficient of dispersant (p) p: density of sample (g/cm3) p0: density of dispersant (g/cm3) t: sedimentation time (sec) X1: distance from the center of rotation to the sedimentation surface X2: distance from the center of rotation to the measuring surface ω: angular velocity (rad/sec) (Preparation of solid titanium catalyst component) There is no specific limitation on the process for preparing the solid titanium catalyst component for olefin polymerization according to the invention. For example, the following processes are available. (1) A magnesium compound in the liquid state is contacted with a liquid titanium compound in the presence of an electron donor (a). (2) A magnesium compound in the liquid state is contacted with an electron donor (a). Then the resulting solution is contacted with a liquid titanium compound (titanium compound in a liquid state) and, optionally, is further contacted with an electron donor (b) and a liquid titanium compound. Next, the materials used for preparing the solid titanium catalyst component are described. Magnesium compound in the liquid state The magnesium compound in the liquid state can be prepared from magnesium compounds having reducing ability or those having no reducing ability. The magnesium compounds having reducing ability referred to above include, for example, organomagnesium compounds represented by the formula XnMgR2-n wherein n is 0 methylmagnesium chloride, propylmagnesium chloride, butylmagnesium chloride, hexylmagnesium chloride, amylmagnesium chloride, butylethoxymagnesium, ethylbutylmagnesium, octylbutylmagnesium, butylmagnesium hydride. These magnesium compounds exemplified above may be singly, or they may form complex compounds with organoaluminum compounds which will be mentioned later. These magnesium compounds used may be either a liquid or a solid. Concrete examples of the magnesium compounds having no reducing ability include; magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide and magnesium fluoride; alkoxymagnesium halides such as methoxymagnesium chloride, ethoxymagnesium chloride, isopropoxymagnesiurn chloride, butoxymagnesium chloride and octoxymagnesium chloride; aryloxymagnesium halides such as phenoxymagnesium chloride and methylphenoxymagnesium chloride; alkoxymagnesiums such as ethoxymagnesium, isopropoxy magnesium, butoxymagnesium, n-octoxymagnesium and 2-ethyIhexoxymagnesium; aryloxymagnesiums such as phenoxymagnesium and dimethyIphenoxymagnesium; magnesium carboxylates such as magnesium laurate and magnesium stearate. The magnesium compounds having no reducing ability exemplified above may be those derived from the above- mentioned magnesium compounds having reducing ability or « may be those derived at the time .of preparation of the catalyst component. The magnesium compounds having no reducing ability may be derived from the magnesium compounds having reducing ability, for example, by bringing the magnesium compounds having reducing ability into contact with a halogen containing compound or a compound having OH group or active carbon-oxygen bond such as polysiloxane compounds, halogen containing silane compounds, halogen containing aluminum compounds, esters or alcohols. Besides the above-mentioned magnesium compounds having reducing ability or having no reducing ability, the magnesium compounds used for the purposes intended may be complex compounds or double compounds with other metals or mixtures with other metals. Furthermore, the magnesium compounds used may be mixtures of two or more kinds of the above-mentioned compounds. Of these magnesium compounds, preferred are those having no reducing ability, especially those containing halogen. Of the halogen containing magnesium compounds, preferred are magnesium chloride, alkoxy magnesium chloride and aryloxy magnesium chloride, particularly magnesium chloride. The magnesium compound described above can be used as the magnesium compound in the liquid state, as they are, when they are liquid. When the magnesium compounds are solid, there can be used as the magnesium compound in the liquid state a magnesium compound solution prepared by « contacting the solid magnesium compound with a compound capable of solubilizing the solid magnesium compound in a hydrocarbon solvent. Further, the magnesium compound solution which is prepared by the above process using the liquid magnesium compound in place of the solid magnesium compound can be used as the magnesium compound in the liquid state. The compound capable of solubilizing the solid magnesium compound is at least one compound selected from the group consisting of alcohols, ethers and esters. Examples of such compounds include: alcohols of 1 to 18 carbon atoms, such as methanol, ethanol, propanol, butanol, pentanol, hexanol, 2-ethylhexanol, octanol, dodecanol, octadecyl alcohol, oleyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol, isopropyl alcohol, isopropylbenzyl alcohol and ethylene glycol; halogen-containing alcohols of 1 to 18 carbon atoms, such as trichloromethanol, trichloroethanol and trichlorohexanol; ethers of 2 to 20 carbon atoms, such as methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, tetrahydrofuran, ethyl benzyl ether, dibutyl ether, anisole and diphenyl ether; and metallic acid esters, such as tetraethoxytitanium, tetra-n-propoxytitanium, tetra-i-propoxytitanium, tetrabutoxytitanium, tetrahexoxytitanium, tetrabutoxyzirconium and tetraethoxyzirconium. Of these, preferable are alcohols, and particularly preferable is 2-ethylhexanol. The compound capable of solubilizing the magnesium compound can be used as the later-described electron donor (a) or (b) . Examples of the hydrocarbon solvents used for preparing the magnesium compound in the liquid state include aliphatic hydrocarbons, such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane and kerosine; alicyclic hydrocarbons, such as cyclopentane, cyclohexane and methylcyclopentane; aromatic hydrocarbons, such as benzene, toluene and xylene; halogenated hydrocarbons, such as ethylene chloride and chlorobenzene; and mixtures of these hydrocarbons. Of these, preferable are aliphatic hydrocarbons, and particularly preferable are decane and hexane. Electron donor (a) Examples of the electron donors (a) used for preparing the solid titanium catalyst component include the above-exemplified alcohols, ethers and metallic acid esters used as the compounds capable of solubilizing the halogen-containing magnesium compound, other alcohols (described below) than the above-mentioned ones, phenols, ketones, aldehydes, amines, pyridines, organic acid esters, aliphatic carboxylic acids, acid anhydrides, aliphatic carbonates, organosilicon compounds, organophosphorus compounds, polycarboxylic acid esters, diethers and polyethers. More specifically, there can be mentioned: alcohols other than the above-mentioned ones, e.g., aliphatic alcohols, such as ethylene glycol, methyl carbitol, 2-methylpentanol, 2-ethylbutanol, decanol, tetradecyl alcohol, undecenol and stearyl alcohol, alicyclic alcohols, such as cyclohexanol and methylcyclohexanol, aromatic alcohols, such as methylbenzyl alcohol, α-methylbenzyl alcohol and α,α-dimethylbenzyl alcohol, and alkoxy group-containing aliphatic alcohols, such as n-butyl cellosolve, 2-butoxyethanol and l-butoxy-2-propanol; phenols having 6 to 20 carbon atoms, which may have a lower alkyl group, such as phenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol, cumylphenol and naphthol; ketones having 3 to 15 carbon atoms, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl n-butyl ketone, acetophenone, benzophenone, benzoquinone and eyelohexanone; aldehydes having 2 to 15 carbon atoms, such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde and naphthaldehyde; amines, such as trimethylamine, triethylamine, tributylamine, tribenzylamine, tetramethylenediamine and hexamethylenediamine; pyridines, such as pyridine, methylpyridine, ethylpyridine, propylpyridine, dimethylpyridine, ethylmethylpyridine, trimethylpyridine, phenylpyridine, benzylpyridine and pyridine chloride; organic acid esters having 2 to 18 carbon atoms, such as methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, i-butyl acetate, t-butyl acetate, octyl acetate, cyclohexyl acetate, methyl chloroacetate, ethyl dichloroacetate, ethyl propionate, ethyl pyruvate, ethyl pivalate, methyl butyrate, ethyl valerate, methyl methacrylate, ethyl crotonate, ethyl eyelohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, γ-butyrolactone, δ-valerolactone, coumarin and phthalide; aliphatic carboxylic acids, such as formic acid, acetic acid, propionic acid, butyric acid and valeric acid; acid anhydrides, such as acetic anhydride, phthalic anhydride, maleic anhydride, benzoic anhydride, trimellitic anhydride and tetrahydrophthalic anhydride; alkoxy group-containing alcohols, such as butyl cellosolve and ethyl cellosolve; aliphatic carbonates, such as dimethyl carbonate, diethyl carbonate and ethylene carbonate; organosilicon compounds, such as methyl silicate, ethyl silicate and diphenyldimethoxysilane, preferably organosilicon compounds represented by the formula R1xR2ySi(OR3)z (R1 and R2 may be the same as or different from each other and are each a hydrocarbon group or halogen, R3 is a hydrocarbon group, 0 organophosphorus compounds having a P-O-C bond, such as trimethyl phosphite and triethyl phosphite. The polycarboxylic acid esters are, for example, compounds having skeletons represented by the following formulas. (Formula Removed) In the above formulas, R4 is a substituted or unsubstituted hydrocarbon group, R5, R8 and R9 are each hydrogen or a substituted or unsubstituted hydrocarbon group, R6 and R7 are each hydrogen or a substituted or unsubstituted hydrocarbon group, and at least one of R6 and R7 is preferably a substituted or unsubstituted hydrocarbon group. R6 and R7 may be linked to each other to form a cyclic structure. When the hydrocarbon groups R4 to R9 are substituted, the substituents contain hetero atoms such as N, 0 and S and have groups such as C-O-C, COOR, COOH, OH, S03H, -C-N-C- and NH2. Examples of such polycarboxylic acid esters include: adipate, diisobutyl adipate, diisopropyl sebacate, di-n-butyl sebacate, di-n-octyl sebacate and'di-2-ethylhexyl sebacate. The diether compounds are, for example, diether compounds having a fluorene ring, which are represented by the following formula (i) . (Formula Removed) In the formula (i) , Ra and Rb may be the same as or different from each other and are each an alkyl group of 1 to 6 carbon atoms, e.g., methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, pentyl or hexyl. X and Y may be the same as or different from each other and are each an alkyl group of 1 to 6 carbon atoms or a halogen atom. m is a number of 0 Examples of the diether compounds having a fluorene ring, which are represented by the formula (i) , include: 9, 9-bis(methoxymethyl)fluorene, 9, 9-bis(ethoxymethyl)fluorene, 9 -me thoxy- 9 -ethoxyme thy 1 fluorene, 9, 9-bis (methoxymethyl) -2, 7-dimethylf luorene, 9,9-bis(methoxymethyl)-2,6-diisopropylfluorene, 9,9-bis(methoxymethyl)-3,6-diisobutylfluorene, 9,9-bis(methoxymethyl)-2-isobutyl-7-isopropylfluorene, 9,9-bis(methoxymethyl)-2,7-dichlorofluorene, and 9,9-bis(methoxymethyl)-2-chloro-7-isopropylfluorene. The polyether compounds are, for example, compounds represented by the following formula: (Formula Removed) wherein n is an integer of 2 Of such compounds, preferably used are 1,3-diethers, and particularly preferably used are: 2,2-diisobutyl-l,3-dimethoxypropane, 2-isopropyl-2-isobutyl-l,3-dimethoxypropane, 2-isopropyl-2-isopentyl-l,3-dimethoxypropane, 2,2-dicyclohexyl-l,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane, 2-cyclohexyl-2-isopropyl-l,3-dimethoxypropane, 2-isopropyl-2-s-butyl-l,3-dimethoxypropane, 2,2-diphenyl-1,3-dimethoxypropane, and 2 -cyclopentyl-2-isopropyl-l., 3-dimethoxypropane. Also employable as the electron donors (a) are: acid halides having 2 to 15 carbon atoms, such as acetyl chloride, benzoyl chloride, toluyl chloride and anisoyl chloride; acid amides, such as N,N-dimethylacetamide, N,N-diethylbenzamide and N,N-dimethyltoluamide; nitriles, such as acetonitrile, benzonitrile and trinitrile,- amines other than the above-mentioned ones, such as methylamine, ethylamine, dimethylamine and diethylamine; pyrroles, such as pyrrole, methylpyrrole and dimethylpyrrole; pyrrolines; pyrrolidines ; indoles; nitrogen-containing cyclic compounds, such as piperidine, quinoline and isoquinoline; and oxygen-containing cyclic compounds, such as tetrahydrofuran, 1,4-cineol, 1,8-cineol, pinolfuran, methylfuran, dimethylfuran, diphenylfuran, benzofuran, coumaran, phthalan, tetrahydropyran, pyran and dihydropyran. Of the above compounds, preferable as the electron donors (a) are acid anhydrides, alcohols, polycarboxylic acids, polyethers and diethers having a fluorene ring. More preferable are acid anhydrides, alkoxy group- containing aliphatic alcohols, aromatic polycarboxylic acid esters, 1,3-diethers and diether.s having a fluorene ring. Particularly preferable are diethers having a fluorene ring. Electron donor (b) Examples of the electron donors (b) used for preparing the solid titanium catalyst component include the same compounds as exemplified above as the electron donors (a). Of such compounds, preferable as the electron donors (b) are acid anhydrides, alcohols, polycarboxylic acids, polyethers and diethers having a fluorene ring. More preferable are acid anhydrides, alkoxy group-containing aliphatic alcohols, aromatic polycarboxylic acid esters, 1,3-diethers and diethers having a fluorene ring. Particularly preferable are diethers having a fluorene ring. The compounds used as the electron donor (a) and the electron donor (b) may be the same as or different from each other. Liquid titanium compound The liquid titanium compound used for preparing the solid titanium catalyst component is, for example, a tetravalent halogen-containing titanium compound represented by the following formula: wherein R is a hydrocarbon group, X is a halogen atom, and 0 Examples of the halogen-containing titanium compounds include: titanium tetrahalides, such as TiCl4, TiBr4 and TiI4; alkoxytitanium trihalides, such as Ti(OCH3)Cl3, Ti(OC2H5)Cl3, Ti(On-C4H9)Cl3, Ti(OC2H5)Br3 and Ti(Oiso-C4H9)Br3; alkoxytitanium dihalides, such as Ti(OCH3)2C12, Ti(OC2H5)2Cl2, Ti(On-C4H9)2Cl2 and Ti (OC2H5) 2Br2 ; alkoxytitanium monohalides, such as Ti(OCH3)3Cl, Ti(OC2H5)3Cl, Ti(On-C4H9)3Cl and Ti (OC2H5)3Br; and tetraalkoxytitaniums, such as Ti(OCH3)4, Ti(OC2H5)4/ Ti(On-C4H9)4/ Ti(Oiso-C4H9)4 and Ti (0-2-ethylhexyl)4. Of these, preferable are titanium tetrahalides, and particularly preferable is titanium tetrachloride. These titanium compounds may be used singly or may be used in the form of a mixture. Further, these titanium compounds may be used after diluted with the above-mentioned hydrocarbon solvents. The process for preparing the solid titanium catalyst component for olefin polymerization is now described in more detail. In this process, a halogen-containing magnesium compound is used for the preparation of the magnesium compound in the liquid state (magnesium compound solution), an alcohol is used as the compound capable of solubilizing the halogen-containing magnesium compound and a diether compound having a fluorene ring is used as the electron donor (a). First of all, the halogen-containing magnesium compound is contacted with the alcohol in the hydrocarbon solvent to prepare a homogeneous solution (magnesium compound solution) in which the halogen-containing magnesium compound is dissolved in a mixed solvent of alcohol and hydrocarbon. In this step, the alcohol is used in an amount of 1 to 40 mol, preferably 1.5 to 20 mol, based on 1 mol of the halogen-containing magnesium compound. The hydrocarbon solvent is used in an amount of 1 to 30 mol, preferably 1.5 to 15 mol, based on 1 mol of the halogen-containing magnesium compound. It is desired that the contact temperature is 65 to 300 °C, preferably 10 to 200 °C, and the contact time is 15 to 300 minutes, preferably 30 to 120 minutes. Then, the magnesium compound solution is contacted with the diether compound having a fluorene ring to prepare a homogeneous solution (magnesium-diether compound solution). In this step, the diether compound having a fluorene ring is used in an amount of 0.01 to 1.0 mol, preferably 0.1 to 0.5 mol, based on 1 mol of the halogen-containing magnesium compound in the magnesium compound solution. It is desired that the contact temperature is -20 to 300 °C, preferably 20 to 200 °C, and the contact time is 5 to 240 minutes, preferably 10 to 120 minutes. Subsequently, the magnesium-diether compound solution is contacted with the liquid titanium compound to prepare a mixed solution (magnesium-titanium solution) containing the halogen-containing magnesium compound and the liquid titanium compound. In this step, the liquid titanium compound is used in an amount of 2 to 100 g-atom, preferably 4 to 50 g-atom, based on 1 g-atom of magnesium in the magnesium-diether compound solution. It is desired that the contact temperature is -70 to 200 °C, preferably -70 to 50 °C, and the contact time is 5 to 300 minutes, preferably 30 to 180 minutes. Then, the magnesium-titanium solution obtained above is heated to a temperature of 20 to 300 °C, preferably 50 to 150 °C, to obtain a solid titanium catalyst component in a suspended state in the hydrocarbon solvent. It is desired that the heating time is 10 to 360 minutes, preferably 30 to 300 minutes. After the contact of the magnesium-diether compound solution with the liquid titanium compound, the resulting magnesium-titanium solution may be contacted with the electron donor (b). In this case, it is preferable that the magnesium-titanium solution is contacted with the electron donor (b) after the solution is heated. As the electron donor (b), the above-mentioned diether compound having a fluorene ring used in the preparation of the magnesium-diether compound solution is employable. The electron donor (b) is used in an amount of 0.01 to 5 mol, preferably 0.1 to 1 mol, based on 1 mol of the magnesium compound. The suspension obtained above is subjected to solid-liquid separation by means of filtration or the like, and the solid (solid titanium catalyst component) is recovered. The solid thus obtained may be further contacted with the liquid titanium catalyst. It is preferable that the obtained solid titanium catalyst component is washed with a hydrocarbon solvent. The solid titanium catalyst component obtained as above can be used as the olefin polymerization catalyst component after it is suspended in a hydrocarbon solvent. It is also possible that the suspension is subjected to solid-liquid separation by filtration or the like and the resulting solid is then dried and used as the olefin polymerization catalyst component. (Olefin polymerization catalyst) The olefin polymerization catalyst according to the invention is formed from: (A) the above-described solid titanium catalyst component, (B) an organometallic compound catalyst component, and (C) an electron donor. (B) Oraanometallic compound catalyst component The organometallic compound catalyst component is preferably a compound containing a metal selected from Group I to Group III of the periodic table. Examples of such compounds include organoaluminum compounds, alkyl complex compounds of Group I metals and aluminum, and organometallic compounds of Group II metals. The organoaluminum compounds are, for example, compounds represented by the following formula: RanAlX3-n wherein Ra is a hydrocarbon group of 1 to 12 carbon atoms, X is halogen or hydrogen, and n is 1 to 3. In the above formula, Ra is a hydrocarbon group of 1 to 12 carbon atoms, e.g., an alkyl group, a cycloalkyl group or an aryl group. Particular examples of these groups include methyl, ethyl, n-propyl, isopropyl, isobutyl, pentyl, hexyl, octyl, cyclopentyl, cyclohexyl, phenyl and tolyl. Examples of such organoaluminum compounds include: trialkylaluminums, such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum and tri-2-ethylhexylaluminum; alkenylaluminums, such as isoprenylaluminum; dialkylaluminum halides, such as dimethylaluminum chloride, diethy1aluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride and dimethylaluminum bromide; alkylaluminum sesquihalides, such as methylaluminum sesquichloride, ethylaluminum sesquichloride, isopropylaluminum sesquichloride, butylaluminum sesquichloride and ethylaluminum sesquibromide; alkylaluminum dihalides, such as methylaluminum dichloride, ethylaluminum dichloride, isopropylaluminum dichloride and ethylaluminum dibromide; and alkylaluminum hydrides, such as diethylaluminum hydride and diisobutylaluminum hydride. Also employable as the organoaluminum compounds are compounds represented by the following formula: RanAlY3-n wherein Ra is the same as above, Y is -ORb group, -OSiRc3 group, -OAlRd2 group, -NRe2 group, -SiRf3 group or -N(Rg)AlRh2 group, n is 1 to 2, Rb, Rc, Rd and Rh are each methyl, ethyl, isopropyl, isobutyl, cyclohexyl, phenyl or the like, Re is hydrogen, methyl, ethyl, isopropyl, phenyl, trimethylsilyl or the like, and Rf and R9 are each methyl, ethyl or the like. Examples of such organoaluminum compounds include: (i) compounds of the formula RanAl (ORb) 3-n, e.g., dimethylaluminum methoxide, diethylaluminum ethoxide and diisobutylaluminum methoxide; (ii) compounds of the formula RanAl (OSiRc)3-n, e.g., Et2Al(OSiMe3) , (iso-Bu)2Al(OSiMe3) and (iso-Bu) 2Al (OSiEt3) ; (iii) compounds of the formula RanAl (OAlRd2) 3-n, e.g., Et2AlOAlEt2 and (iso-Bu) 2A10A1(iso-Bu)2; (iv) compounds of the formula RanAl (NRe2)3-n e.g., Me2AlNEt2, Et2AlNHMe, Me2AlNHEt, Et2AlN(Me3Si) 2 and (iso-Bu) 2AlN(Me3Si) 2; (v) compounds of the formula RanAl (SiRf3) 3-n e.g., (iso-Bu)2AlSiMe3; and (vi) compounds of the formula RanAl [N(R?) -AlRh2]3-n, e.g., Et2AlN(Me)AlEt2 and (iso-Bu) 2AlN(Et) Al (iso-Bu) 2 . In the above examples, Me represents methyl, Et represents ethyl, and Bu represents butyl. Also employable are compounds analogous to the above compounds, for example, organoaluminum compounds wherein two or more aluminum atoms are linked through an oxygen atom or a nitrogen atom. Examples of such compounds include: (C2H5)2A10A1(C2H5)2, (C4H9)2A10A1(C4H9)2, and (C2H5)2A1N(C2H5)A1(C2H5)2. Aluminoxanes such as methylaluminoxane can be also exemplified as preferable oranoaluminum compounds. Of the organoaluminum compounds mentioned above, preferable are those represented by the formulas Ra3Al, RanAl (ORb)3-n and RanAl (OAlRd2) 3-n. The alkyl complex compound of a Group I metal and aluminum includes, for example, compounds represented by the following formula: M1AlRj4 wherein M1 is Li, Na or K, and Rj is a hydrocarbon group of 1 to 15 carbon atoms. Examples of such compounds include LiAl(C2H5)4 and LiAl(C7H15)4: The organometallic compounds of Group II metals are, for example, compounds represented by the following formula: RkRlM2 wherein Rk and R1 are each a hydrocarbon group of 1 to 15 carbon atoms or a halogen, they may be the same as or different from each other except that each of them is halogen, and M2 is Mg, Zn or Cd. Examples of such compounds include diethylzinc, diethylmagnesium, butylethylmagnesium, ethylmagnesium chloride and butylmagnesium chloride. The compounds mentioned above may be used in combination of two or more kinds. (C) Electron donor The electron donor (C) employable in the invention is, for example, an organosilicon compound represented by the following formula: RnSi(OR')4-n wherein R and R' may be the same as or different from each other and are each a hydrocarbon group, and 0 Examples of the organosilicon compounds represented by the above formula include: trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, bis-p-tolyldiethoxysilane, bisethylphenyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexy Ime thy Idime thoxys i lane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-proyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, n-butyltriethoxysilane, iso-butyltriethoxysilane, phenyltriethoxysilane, γ-amynopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane, 2- norbornanemethyldimethoxysilane, ethyl silicate, butyl silicate, trimethyIphenoxysilane, methyltriallyloxysilane, vinyltris(p-methoxyethoxysilane), vinyltriacetoxysilane, dimethyltetraethoxydisiloxane, cyclopentyltrimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethylcyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, dicyclopentyldimethoxysilane, bis(2-methylcyclopentyl)dimethoxysilane, bis (2,3-dimethyleyelopentyl)dimethoxysilane, dicyclopentyldiethoxysilane, p-tolylmethyldimethoxysilane, di-1-butyldimethoxys ilane, tricyclopentylmethoxysilane, tricyclopentylethoxysilane, dicyclopentylmethyImethoxysilane, dicyclopentylethylmethoxysilane, hexenyltrimethoxysilane, dicyclopentylmethylethoxysilane, cyclopentyldimethylmethoxysilane, cyclopentyldiethyImethoxysilane and cyclopentyldimethylethoxysilane. Of these, preferably used are ethyltriethoxysilane, n-propyltriethoxysilane, t-butyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, bis-p-tolyldimethoxysilane, p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, ccyclohexyIme thyIdime thoxysi1ane, 2 -norbornanetriethoxysilane, 2-norbornanernethyIdimethoxysilane, dicyclopentyldimethoxysilane, hexenyltrimethoxysilane, cyclopentyltriethoxysilane, tricyclopentylmethoxysilane, di-t-butyldimethoxysilane and cyclopentyldimethylmethoxysilane. In the present invention, also employable as the electron donors (C) are: nitrogen-containing electron donors, e.g., 2,6-substituted piperidines, 2,5-substituted piperidines, substituted methylenediamines, such as N,N,N',N'-tetramethylmethylenediamine and N,N,N',N'-tetraethylmethylenediamine, and substituted imidazolidines, such as 1,3-dibenzylimidazolidine and 1,3-dibenzyl-2-phenylimidazolidine; phosphorus-containing electron donors, e.g., phosphites, such as triethyl phosphite, tri-n-propyl phosphite, triisopropyl phosphite, tri-n-butyl phosphite, triisobutyl phosphite, diethyl-n-butyl phosphite and diethylphenyl phosphite; and oxygen-containing electron donors, such as 2,6-substituted tetrahydropyrans and 2,5-substituted tetrahydropyrans. These electron donors (C) may be used in combination of two or more kinds. The olefin polymerization catalyst according to the invention may contain other components useful for the olefin polymerization, in addition to the above-mentioned components. The olefin polymerization catalyst of the invention may be a prepolymerized olefin-containg catalyst. The prepolymerized olefin-containing catalyst can be obtained by pre(co)polymerizing olefin(s) used in the later-described polymerization and optionally polyene compounds, in the presence of the solid titanium catalyst component (A) , the organometallic compound catalyst component (B), and optionally, the electron donor (C). (Olefin polymerization process) In the olefin polymerization process according to the invention, olefin(s) is polymerized or copolymerized in the presence of the olefin polymerization catalyst comprising the solid titanium catalyst component (A), the organometallic compound catalyst component (B) and the electron donor (C) or in the presence of the olefin polymerization catalyst further containing a prepolymer (prepolymerized olefin). Examples of the olefins polymerized in the invention include α-olefins of 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-l-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 4-methyl-l-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-l-hexene, 3-ethyl-l-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1- hexadecene, 1-octadecene and 1-eicosene. These α-olefins may be used singly or in combination of two or more kinds. Of these, preferably used are ethylene, propylene, 1-butene, 3-methyl-1-butene, 3-methyl-l-pentene and 4-methy1- 1-pentene. Together with the α-olefins, there can be optionally used: aromatic vinyl compounds, such as styrene, substituted styrenes, allylbenzene, substituted allylbenzenes, vinylnaphthalenes, substituted vinylnaphthalenes, allylnaphthalenes and substituted allylnaphthalenes; alicyclic vinyl compounds, such as vinylcyclopentane, substituted vinylcyclopentanes, vinylcyclohexane, substituted vinylcyclohexanes, vinylcycloheptane, substituted vinylcycloheptanes and allylnorbornane; cycloolefins, such as cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene and 2-methyl-l,4,5,8-dimethano-l,2, 3,4,4a,5,8,8a-octahydronaphthalene; silane unsaturated compounds, such as allyltrimethylsilane, allyltriethylsilane, 4-trimethylsilyl-1-butene, 6-trimethylsilyl-1-hexene, 8-trimethylsilyl-1-octene and 10-trimethylsilyl-l-decene; and polyene compounds. In the present invention, the polymerization can be carried out as any of liquid phase polymerization, e.g., solution polymerization or suspension polymerization, and gas phase polymerization . When the polymerization is carried out as slurry polymerization, a hydrocarbon which is inert to the reaction can be used as a solvent, or an olefin which is liquid at the reaction temperature can be used as a solvent. Of the hydrocarbon solvents, aliphatic hydrocarbon solvents are preferably employed. In the polymerization process of the invention, the solid titanium catalyst component (A) or the prepolymerized olefin-containing catalyst is used in an amount of usually about 0.001 to 100 mmol, preferably about 0.005 to 20 mmol, in terms of titanium atom, based on 1 liter of the polymerization volume. The organometallic compound catalyst component (B) is used in such an amount that the amount of the metal atom in the catalyst component (B) becomes usually about 1 to 2,000 mol, preferably about 2 to 500 mol, based on 1 mol of the titanium atom contained in the solid titanium catalyst component (A) in the polymerization system. The electron donor (C) is used in an amount of usually about 0.001 to 10 mol, preferably 0.01 to 5 mol, based on 1 mol of the metal atom in the catalyst component (B). If hydrogen is used in the polymerization process, the molecular weight of the resulting polymer can be adjusted, and a polymer having a high melt flow rate can be obtained. The polymerization process of the invention is carried out under the following conditions, though the conditions vary depending on the olefin used. The polymerization temperature is in the range of usually about 20 to 300 °C, preferably about 50 to 150 °C, and the polymerization pressure is in the range of atmospheric pressure to 100 kg/cm2, preferably about 2 to 50 kg/cm2. In the present invention, the polymerization can be carried out either batchwise, semi-continuously or continuously. Further, the polymerization can be conducted in two or more stages under different conditions. In the process of the invention, a homopolymer of an olefin may be prepared, or a random copolymer or a block copolymer may be prepared from two or more kinds of olefins. When the olefin polymerization process is carried out using the olefin polymerization catalyst as described above, an olefin polymer can be prepared with extremely high polymerization activity. Moreover, when an olefin of 3 or more carbon atoms is polymerized, an olefin polymer of high stereoregularity can be prepared. When propylene is polymerized in accordance with the olefin polymerization process of the invention, high-stereoregular polypropylene having isotactic stereospecificity (stereoregularity) I.I. of 94.5 to 98.5 % can be obtained. The olefin polymer obtained by the process of the invention has a melt flow rate (MFR, ASTM D 1238E) of usually not more than 5,000 g/10 min, preferably 0.01 to 3,000 g/10 min, more preferably 0.02 to 2,000 g/10 min, particularly preferably 0.05 to 1,000 g/10 min. The intrinsic viscosity [Tl] of the olefin polymer, as measured in decalin at 135 °C, is in the range of usually 0.05 to 20 dl/g, preferably 0.1 to 15 dl/g, particularly preferably 0.2 to 13 dl/g. The olefin polymer obtained by the present invention can be blended with various additives such as heat stabilizer, weathering stabilizer, antistatic agent, anti¬blocking agent, lubricant, pigment, dye, and inorganic or organic filler. EFFECT OF THE INVENTION The solid titanium catalyst component for olefin polymerization according to the invention has a specific microcrystalline size, a specific volume of pores having a radius of not more than 0.1 |M, a specific volume of pores having a radius of 0.1 to 7.5 ^m and a specific mean catalyst particle diameter. By the use of the catalyst component, therefore, olefins can be polymerized with high polymerization activity. Moreover, when α-olefins of 3 or more carbon atoms are polymerized, olefin (co)polymers of high stereoregularity can be obtained. The use of the process for preparing a solid titanium catalyst component for olefin polymerization according to the invention can povide a catalyst component having the above-mentioned excellent properties. By the use of the olefin polymerization catalyst and the olefin polymerization process according to the invention, olefins can be polymerized with high polymerization activity. Moreover, when α-olefins of 3 or more carbon atoms are polymerized, olefin (co)polymers of high stereoregularity can be obtained. EXAMPLE The present invention will be further described with reference to the following examples, but it should be construed that the invention is in no way limited to those examples. Example 1 Preparation of solid titanium catalyst component (A) 47.7 g of anhydrous magnesium chloride, 235 ml of purified toluene and 195.3 g of 2-ethylhexyl alcohol were heated at 120 °C under reflux for 3 hours to give a homogeneous solution. To the solution was added 19.1 g of 9,9-bis(methoxymethyl)fluorene having the below-described structure, and they were mixed by stirring at 120 °C under reflux for 1 hour to completely dissolve the 9,9-bis(methoxymethyl)fluorene in the solution. (Formula Removed) The resulting homogeneous solution was cooled to room temperature. Then, to 80 ml of titanium tetrachloride maintained at -20 °C, 30 ml of the homogeneous solution was dropwise added over a period of 20 minutes. After the addition was completed, the temperature of the mixed solution was raised to 110 °C over a period of 4 hours and then stirred at this temperature for 2 hours. After the 2-hour reaction was completed, the resulting solid was recovered by hot filtration and resuspended in 110 ml of titanium tetrachloride. The suspension was again heated up to 110 °C with stirring, and thermal reaction was run for 2 hours. After the reaction was completed, the resulting solid was again recovered by hot filtration. The solid was washed with decane at 110 °C and then further washed sufficiently with hexane at room temperature until any titanium compound liberated in the washing liquid was not detected. The solid titanium catalyst component (A) obtained by the above process was stored as a decane slurry, while a part of the slurry was dried to examine the catalyst composition. With respect to the solid titanium catalyst component (A), the microcrystalline size was 26 A, the volume of pores having a radius of not more than 0.1 µm was 0.002 cm3/g, the volume of pores having a radius of 0.1 to 7.5 µm was 0.560 cm3/g, and the mean catalyst particle diameter, as measured by a light transmission sedimentation method, was 11.2µm. In the solid titanium catalyst component (A), 4.7 % by weight of titanium, 54 % by weight of chlorine, 15 % by weight of magnesium and 16.2 % by weight of 9,9-bis(methoxymethyl)fluorene were contained. Polymerization Into a 1-liter autoclave, 400 ml of purified n-heptane was introduced. Then, 0.4 mmol of triethylaluminum, 0.04 mmol of cyclohexylmethyldimethoxysilane and 0.004 mmol (in terms of titanium atom) of the solid titanium catalyst component (A) were fed to the autoclave at 6 °C in a propylene atmosphere. Further, 75 ml of hydrogen was fed at 60 °C. The temperature of the system was raised to 70 °C and maintained at this temperature for 1 hour to preform polymerization of propylene. The pressure during the polymerization was kept at 5 kg/cm2-G. After the polymerization was completed, the slurry containing a solid produced was filtered to separate the slurry into a white powder and a liquid phase portion. The yield of the white powder polymer after dried was 90.5 g, and the boiling heptane extraction residue of this polymer (I.I.) was 98.74 %. Further, the polymer had MFR of 3.5 g/10 min and an apparent bulk density of 0.41 g/cm3. On the other hand, concentration of the liquid phase portion resulted in 0.2 g of a solvent-soluble polymer. Therefore, the activity was 22,700 g-PP/mmol-Ti, and it was 21,700 g-PP/g-catalyst. The boiling heptane extraction residue of the whole polymer obtained (t-I.I.) was 98.5 %. Example 2 Preparation of solid titanium catalyst component (B) 95.3 g of anhydrous magnesium chloride, 485 ml of decane and 390.6 g of 2-ethylhexyl alcohol were heated at 140 °C for 3 hours to give a homogeneous solution. To the solution was added 22.2 g of phthalic anhydride, and they were mixed by stirring at 130 °C for 1 hour to dissolve the phthalic anhydride in the solution. The resulting homogeneous solution was cooled to room temperature. Then, to 80 ml of titanium tetrachloride maintained at -20 °C, 30 ml of the homogeneous solution was dropwise added over a period of 20 minutes. After the addition was completed, the temperature of the mixed solution was raised to 110 °C over a period of 4 hours. When the temperature reached 110 °C, 1.91 g of 9,9-bis(methoxymethyl)fluorene previously dissolved in toluene was added to the mixed solution, and then they were reacted at this temperature for 2 hours with stirring. After the 2-hour reaction was completed, the resulting solid was recovered by hot filtration and resuspended in 110 ml of titanium tetrachloride. The suspension was again heated up to 110 °C with stirring, and thermal reaction was run for 2 hours. After the reaction was completed, the resulting solid was again recovered by hot filtration. The solid was sufficiently washed with decane at 110 °C and then with hexane until any titanium compound liberated in the washing liquid was not detected. The solid titanium catalyst component (B) obtained by the above process was stored as a decane slurry, while a part of slurry was dried to examine the catalyst composition. With respect to the solid titanium catalyst component (B), the microcrystalline size was 46 A, the volume of pores having a radius of not more than 0.1µm was 0.128 cm3/g, the volume of pores having a radius of 0.1 to 7.5µm. was 0.431 cm3/g, and the mean catalyst particle diameter, as measured by a light transmission sedimentation method, was 12.1µm. In the solid titanium catalyst component (B) , 2.5 % by weight of titanium, 60 % by weight of chlorine, 18 % by weight of magnesium and 8.6 % by weight of 9,9-bis(methoxymethyl)fluorene were contained. Polymerization Polymerization of propylene was carried out in the same manner as in Example 1, except that the solid titanium catalyst component (B) was used in place of the solid titanium catalyst component (A). The yield of the white powder polymer after dried was 89.3 g, and the boiling heptane extraction residue of this polymer (I.I.) was 98.33 %. Further, the polymer had MFR of 5.1 g/10 min and an apparent bulk density of 0.38 g/cm3. On the other hand, concentration of the liquid phase portion resulted in 1.0 g of a solvent-soluble polymer. Therefore, the activity was 22,600 g-PP/mmol-Ti, and it was 11,800 g-PP/g-catalyst. The boiling heptane extraction residue of the whole polymer obtained (t-I.I.) was 97.3 %. Comparative Example 3 Preparation of solid titanium catalyst component (C) 95.3 g of anhydrous magnesium chloride, 485 ml of decane and 390.6 "g of 2-ethylhexyl alcohol were heated at 140 °C for 2 hours to give a homogeneous solution. To the solution was added 34.6 ml of 2-isopropyl-2-isobutyl-l,3-dimethoxypropane having the below-described structure, and they were mixed by stirring at 130 °C for 1 hour. (Formula Removed) The resulting homogeneous solution was cooled to room temperature. Then, to 80 ml of titanium tetrachloride maintained at -20 °C, 30 ml of the homogeneous solution was dropwise added over a period of 20 minutes. After the addition was completed, to the solution was further added 7.5 ml of methyl hydrogenpolysiloxane. Then, the temperature of the mixed solution was raised to 110 °C over a period of 4 hours and stirred at this temperature for 2 hours. After the 2-hour reaction was completed, the resulting solid was recovered by hot filtration and resuspended in 110 ml of titanium tetrachloride. The suspension was again heated up to 110 °C with stirring, and thermal reaction was run for 2 hours. After the reaction was completed, the resulting solid was again recovered by hot filtration. The solid was washed with decane at 110 °C and then further washed sufficiently with hexane at room temperature until any titanium compound liberated in the washing liquid was not detected. The solid titanium catalyst component (C) obtained by the above process was stored as a decane slurry, while a part of the slurry was dried to examine the catalyst composition. With respect to the solid titanium catalyst component (C), the microcrystalline size was 153 A, the volume of pores having a radius of not more than 0.1 pm was 0.179 cm3/g, the volume of pores having a radius of 0.1 to 7.5 fim was 0.383 cm3/g, and the mean catalyst particle diameter, as measured by a light transmission sedimentation method, was 13.6 µm. In the solid titanium catalyst component (C) , 19.0 % by weight of titanium, 53 % by weight of chlorine, 6 % by weight of magnesium and 5.8 % by weight of 2-isopropyl-2-isobutyl-l,3-dimethoxypropane were contained. Polymerization Polymerization of propylene was carried out in the same manner as in Example 1, except that the solid titanium catalyst component (C) was used in place of the solid titanium catalyst component (A). After the polymerization was completed, the slurry containing a solid produced was filtered to separate the slurry into a white powder and a liquid phase portion. The yield of the white powder polymer after dried was 3.2 g, and the boiling heptane extraction residue of this polymer (I.I.) was 96.23 %. Further, the polymer had a melt flow rate (MFR) of 7.8 g/10 min and an apparent bulk density of 0.26 g/cm3. On the other hand, concentration of the liquid phase portion resulted in 0.1 g of a solvent-soluble polymer. Therefore, the activity was 800 g-PP/mmol-Ti, and it was 3,300 g-PP/g-catalyst. The boiling heptane extraction residue of the whole polymer obtained (t-I.I.) was 93.3 %. The results are set forth in Tables 1 and 2. Table 1 (Table Removed) *1: 9,9-bis(methoxymethyl)fluorene *2: pore radius: not more than 0.1 µm *3: pore radius: 0.1 to 7.5µm Table 2 (Table Removed) We Claim: 1. A process for preparing a solid titanium catalyst component for olefin polymerization which process comprises the steps of contacting a halogen containing magnesium compound in a liquid state to contact with of a diether compound having a fluorene ring represented by the following formula (i), and allowing the resulting solution to contact with a liquid titanium compound;(Compound Removed) wherein Ra and Rb may be the same as or different from each other and are each, an alkyl group of selected from methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, pentyl and hexyl; X and Y may be-the same as or different from each other and are each methyl, iso-propyl, iso-butyl or chlorine atom, m is a number of 0 > m > 4, and n is a number of 0 3 A process for preparing a solid titanium catalyst component substantially as herein described with reference to the foregoing examples. |
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1516-del-1997-correspondence-others.pdf
1516-del-1997-correspondence-po.pdf
1516-DEL-1997-Description (Complete).pdf
1516-del-1997-petition-138.pdf
Patent Number | 215045 | |||||||||||||||
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Indian Patent Application Number | 1516/DEL/1997 | |||||||||||||||
PG Journal Number | 10/2008 | |||||||||||||||
Publication Date | 07-Mar-2008 | |||||||||||||||
Grant Date | 20-Feb-2008 | |||||||||||||||
Date of Filing | 06-Jun-1997 | |||||||||||||||
Name of Patentee | MITSUI CHEMICALS, INC. | |||||||||||||||
Applicant Address | 5-2 HIGASHI-SHIMBASHI 1-CHOME, MINATO-KU, TOKYO, JAPAN. | |||||||||||||||
Inventors:
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PCT International Classification Number | C08F 4/16 | |||||||||||||||
PCT International Application Number | N/A | |||||||||||||||
PCT International Filing date | ||||||||||||||||
PCT Conventions:
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