GB2104531A - Process for preparing polyolefins - Google Patents

Abstract

Olefins are polymerized with a high stereospecificity by using a catalyst which comprises a combination of a solid catalyst component with a mixture or addition compound of an organometallic compound and an organic acid ester. The above solid catalyst component is obtained by supporting on a solid substance a titanium compound or an addition compound of a titanium compound and an organic acid ester. The above solid substance is obtained by contacting and reacting the following components: (1) a magnesium halide, (2) a compound represented by the general formula Si(OR)mX4-m where R is a hydrocarbon radical having 1 to 24 carbon atoms, X is a halogen atom and m is 0</=m</=4 (3) an aluminium halide and, if desired, (4) an organocarboxylic acid anhydride or an organocarboxylic acid halide.

Description

SPECIFICATION Process for preparing polyolefins The present invention relates to a process for polymerizing ar-olefins in high activity and with high stereospecificity by using a novel catalyst.

As high stereospecific polymerization catalysts for a-olefins, there have heretofore been known catalysts comprising titanium halides and organoaluminium compounds. However, although polymerizations using such known catalysts afford highly stereospecific polymers, it is necessary to remove catalyst remaining in the resulting polymer because of low catalyst activity.

Recently, various proposals have been made for improving the catalyst activity. According to those proposals, a high catalyst activity is attained when using a catalyst component which comprises an inorganic solid carrier such as, for example, MgCI2, and titanium tetrachloride supported thereon.

In the preparation of polyolefins, however, it is preferabie that the catalyst activity be as high as possible. From this standpoint, a more highly active catalyst has been desired. It is also important that the proportion of atactic portion in the resulting polymer be as small as possible.

It is the object of the present invention to provide a process for preparing highly stereospecific polyolefins in extremely high activity by using a novel catalyst.

The above-mentioned object of the present invention can be attained by performing polymerization of at least one a-olefin in the presence of a catalyst which comprises a combination of a solid catalyst component with a mixture or addition compound of an organometallic compound and an organic acid ester, the said solid catalyst component being obtained by supporting a titanium compound and/or an addition compound of a titanium compound and an organic acid ester on a solid substance, which solid substance is obtained by contacting and reacting (1) a magnesium halide, (2) a compound represented by the general formula Si(OR)mX4~m wherein R is a hydrocarbon radical having 1 to 24 carbon atoms, X is a halogen atom and m is O ~ m 6 4, (3) an aluminium halide and if desired (4) an organocarboxylic acid anhydride and/or an organocarboxylic acid halide.

According to the process of the present invention it is possible to prepare highly stereospecific polyolefins in extremely high activity.

By using the catalyst of the present invention there can be obtained various effects, for example, the partial pressure of monomer during polymerization is low and the amount of catalyst remaining in the resulting polymer after a short time polymerization is so small that the polyolefin manufacturing process can dispense with the catalyst removing step, and further the proportion of atactic portion in the resulting polymer is very low.

The method of obtaining the solid catalyst component used in the invention by contacting and reacting (1 ) a magnesium halide, (2) a compound of the general formula Si(OR)mX4~m, (3) an aluminum halide and if desired (4) an organocarboxylic acid anhydride and/or an organocarboxylic acid halide, is not specially limited. Those components may be reacted by contacting for usually 5 minutes to 20 hours under heating at a temperature ranging from 200 to 4000C, preferably from 500 to 3000C and in the presence or absence of an inert solvent, or may be reacted by co-pulverization treatment, or may be reacted by suitably combining these methods.

The order of reacting components (1) through (3) is not specially limited, either. All of them may be reacted together, or two of them may reacted followed by reaction therewith of the remaining one component.

The reaction order of components (1) through (4) is also not specially limited, either. All of them may be reacted together, or three of them may reacted followed by reaction therewith of the remaining one component, or after reacting two of them, the remaining two components may be reacted therewith, or after reacting two of them, one of the remaining two may be reacted therewith, followed by reaction therewith of the remaining one component.

Inert solvents which may be used in the reaction are not particularly limited. Usually, hydrocarbons and/or derivatives thereof not inactivating Ziegler type catalysts are employable, examples of which include various saturated aliphatic hydrocarbons, aromatic hydrocarbons and alicyclic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, benzene, toluene, xylene and cyclohexane, as well as alcohols, ethers and esters such as ethanol, diethyl ether, tetrahydrofuran, ethyl acetate and ethyl benzoate.

The solid carrier used in the invention is obtained, preferably, by co-pulverization treatment of the above components. It is desirable that the co-pulverization treatment be carried out for 0.5 to 30 hours at a temperature ranging usually from 0 to 2000C, preferably from 200 to 1 000C by using an apparatus such as a ball mill, a vibration mill, a rod mill or an impact mill.

In the present invention, component (1 ) i.e. the magnesium halide and component (2) i.e. the compound of the general formula Si(OR)mX4~m are used in a ratio ranging from 1:0.001 to 1 :10, preferably from 1:0.01 to 1 :1, in terms of molar ratio of component (1) to component (2). Component (3) i.e. the aluminium halide is used in a ratio ranging from 1:0.001 to 1 :10, preferably from 1:0.01 to 1:1, in terms of molar ratio of component (1) to component (3). In the case of using component (4) i.e.

the organocarboxylic acid anhydride and/or an organocarboxylic acid halide, it is used in a ratio ranging from 1:0.001 to 1 :10, preferably from 1 :0.01 to 1 :1, in terms of molar ratio of component (1) to component (4).

By supporting a titanium compound and/or an addition compound of a titanium compound and an organic acid ester on the solid carrier thus prepared, there is obtained the solid catalyst component. As the method of supporting the former on the latter, known methods may be used. For example, the solid carrier may be contacted with an excess of a titanium compound and/or an addition compound of a titanium compound and an organic acid ester under heating and in the presence or absence of an inert solvent. Preferably and conveniently, both are heated at 50-3000C, preferably 100-1 500C, in the presence of an inert solvent such as n-hexane. The reaction time is not specially limited, but usually it is not shorter than 5 minutes, and the contact treatment may be performed over a long period of time though not necessary.For example, the treating time may range from 5 minutes to 10 hours. Of course, this treatment should be conducted in an inert gas atmosphere free from oxygen and moisture. After the reaction, unreacted titanium compound and/or addition compound of a titanium compound and an organic acid ester may be removed by any suitable means. For example, the reaction product may be washed several times with a solvent which is inert to Ziegler type catalysts, followed by evaporation of the washings under reduced pressure, whereby a solid powder is obtainable.Another preferred method involves co-pulverization between the solid carrier and a required amount of a titanium compound and/or an addition compound of a titanium compound and an organic acid ester, whereby the abovementioned washing-off step can be omitted, and therefore this co-pulverization method is particularly preferred in the present invention. The co-pulverization between both components may be carried out by using a co-pulverizing apparatus, which is not specially limited, such as a ball mill, a vibration mill, a rod mill or an impact mill at a temperature ranging from 0 to 2000C, preferably from 20C to 1 000C and for a period of time ranging from 0.5 to 30 hours, whereby the solid catalyst component used in the invention can be prepared.Of course, the co-pulverizing operation should be performed in an inert gas atmosphere, and moisture should be avoided.

As the magnesium halide used in the present invention, substantially anhydrous ones are employable, examples of which include magnesium fluoride, magnesium chloride, magnesium bromide, magnesium iodide, and mixtures thereof, with magnesium chloride being particularly preferred.

By way of illustrating the compound of the general formula Si(OR)mX4~m used in the present invention, wherein R is a hydrocarbon radical such as an alkyl, aryl or aralkyl group having 1 to 24 carbon atoms, X is a halogen atom and m is O < m 4, mention may be made of the following: silicon tetrachloride, monomethoxy trichlorosilane, monoethoxy trichlorosilane, monoisopropoxy trichlorosilane, mono-n-butoxy trichlorosilane, monopentoxy trichlorosilane, monooctoxy trichlorosilane, monostearoxy trichlorosilane, monophenoxy trichlorosilane, mono-p-methylphenoxy trichlorosilane, dimethoxy dichlorosilane, diethoxy dichlorosilane, diisopropoxy dichlorosilane, di-n-butoxy dichlorosilane, dioctoxy dichlorosilane, trimethoxy monochlorosilane, triethoxy monochlorosilane, triisopropoxy mondchlorosilane, tri-n-butoxy monochlorosilane, tri-sec-butoxy monochlorosilane, tetraethoxysilane, and tetraisopropoxysilane.

Examples of the aluminium halide used in the invention include aluminium chloride, aluminium bromide and aluminium iodide with aluminium chloride being particularly preferred.

Preferred examples of the organocarboxylic acid anhydride which may be used in the invention include compounds of the following general formulae:

wherein R1, R2, R3, R4, R5, R6, R7 and Rs are each hydrogen or an alkyl, alkenyl or aryl group having -I to 24 carbon atoms and Y is hydrogen, halogen or an alkyl or alkenyi group having 1 to 24 carbon atoms, and the six-membered ring in the formula (lV) is a benzene ring or a six-membered ring comprising saturated carbon bonds or may partially contain unsaturated carbon-carbon bond.Examples of such compounds include acetic anhydride, propionic anhydride, n-butyric anhydride, isobutyric anhydride, caproic anhydride, isocaproic anhydride, caprylic anhydride, lauric anhydride, palmitic anhydride, stearic anhydride, crotonic anhydride, phenylacetic anhydride, succinic anhydride, dimethylsuccinic anhydride, glutaric anhydride, maleic anhydride, diphenylmaleic anhydride, benzoic anhydride, toluic an hydride, phthalic an hydride, naphthalic anhydride, and pyromellitic dianhydride, with benzoic anhydride and toluic anhydride being particularly preferred.

Preferred examples of the organocarboxylic acid halide which may be used in the present invention include compounds of the general formula

wherein R is a hydrocarbon radical such as an alkyl, aryl or aralkyl group having 1 to 24 carbon atoms and X is a halogen atom. Examples of such compounds include acetyl fluoride, acetyl chloride, acetyl bromide, acetyl iodide, propionyl chloride, propionyl bromide, n-butyryl chloride, sec-butyryl chloride, tbutyryl chloride, n-valeryl chloride, isovaleryl chloride, n-caproyl chloride, capryl chloride, stearcyl chloride, benzoyl chloride, benzoyl fluoride, benzoyl bromide, benzoyl iodide, toluoyl chloride, toluoyl fluoride, toluoyl bromide, and naphthoyl chloride, with benzoyl chloride and toluoyl chloride being particularly preferred.

Preferred examples of the titanium compound used in the present invention are tetravalent and trivalent titanium compounds. As tetravalent titanium compounds, those of the general formula Ti(OR)nX4~n wherein R is a hydrocarbon radical such as an alkyl, aryl or aralkyl group having 1 to 20 carbon atoms, X is a halogen atom and n is O < n < = 4, are preferred, examples of which include titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, monomethoxy trichlorotitanium, dimethoxy dichlorotitanium, trimethoxy monochlorotitanium, tetramethoxytitanium, monoethoxy trichlorotitanium, diethoxy dichlorotitanium, triethoxy monochlorotitanium, tetraethoxy titanium, monoisopropoxy trichlorotitanium, diisopropoxy dichlorotitanium, triisopropoxy monochlorotitanium, tetraisopropoxytitanium, monobutoxy trichlorotitanium, dibutoxy dichlorotitanium, monopentoxy trichlorotitanium, monophenoxy trichlorotitanium, diphenoxy dichlorotitanium, triphenoxy monochlorotitanium, and tetraphenoxytitanium. As trivalent titanium compounds there may be used, for example, titanium trihalides obtained by reducing titanium tetrahalides such as titanium tetrachloride and titanium tetrabromide with hydrogen, aluminium, titanium or an organometallic compound of a metal of Groups I-Ill in the Periodic Table, as well as trivalent titanium compounds obtained by reducing tetravalent alkoxytitanium halides of the general formula Ti(QR)mX4~m wherein R is a hydrocarbon radical such as an alkyl, aryl or araikyl group having 1 to 20 carbon atoms, X is a halogen atom and m is O < m < 4, with an organometallic compound of a metal of Groups I-Ill in the Periodic Table.

Preferred examples of the addition compound of a titanium compound and an organic acid ester are those having a molar ratio of titanium compound to organic acid ester in the range of 2:1 to 1:2.

Examples of such addition compounds include TiCI4 TICI, 2C,H,COOC,H,, TiCI, p- CH30C6H5COOC2H5, and TiCI3 C6H5COOC2H5.

The amount of the titanium compound and/or the addition compound of a titanium compound and an organic acid ester is not specially limited, but preferably it is adjusted so that the amount of titanium compound contained in the resulting solid product is in the range of 0.5 to 20%, preferably 1 to 10%, by weight.

The organometallic compound used in the present invention may be selected from organometallic compounds of Group l-IV metals in the Periodic Table, with organoaluminium compounds and organozinc compounds being preferred, examples of which include organoaluminium compounds of the general formulae R3AI, R2AIX, RAIX2, R2AIOR, RAI(OR)X and R3AI2X3 wherein R, which may be alike or different, is an alkyl or aryl group having 1 to 20 carbon atoms and X is a halogen atom, and organozinc compounds of the general formula R2Zn wherein R, which may be alike or different, is an alkyl group having 1 to 20 carbon atoms, such as triethylaluminium, triisopropylaluminium, triisobutylaluminium, tri-sec-butylaluminium, tri-tert-butylaluminium, trihexylaluminium, trioctylaluminium, diethylaluminiumchloride, diisopropylaluminiumchloride, ethylaluminiumsesquichloride, diethylzinc, and mixtures thereof.

In the present invention, the organometallic compound component is used as a mixture or addition compound of the organometallic compound as exemplified above and an organic acid ester. In the case of using it as a mixture of both, the organic acid ester is used in an amount ranging usually from 0.1 to 1 mole, preferably from 0.2 to 0.5 mole, per mole of the organometallic compound, while in the case of using it as an addition compound of both, the addition compound preferably has a molar ratio of the organometallic compound to the organic acid ester in the range of 2:1 to 1:2.

The amount of the organometallic compound used in the present invention is not specially limited, but usually it may range from 0.1 to 1,000 moles per mole of the titanium compound.

Organic acid esters which may be used in the present invention are esters of saturated or unsaturated mono- or dibasic organic carboxylic acids having 1 to 24 carbon atoms and alcohols having 1 to 30 carbon atoms. Examples thereof include methyl formate, ethyl acetate, amyl acetate, phenyl acetate, octyl acetate, methyl methacrylate, ethyl stearate, methyl benzoate, ethyl benzoate, n-propyl benzoate, iso-propyl benzoate, butyl benzoate, hexyl benzoate, cyclopentyl benzoate, cyclohexyl benzoate, phenyl benzoate, 4-tolyl-benzoate, methyl salicylate, ethyl salicylate, methyl p hydroxybenzoate, ethyl p-hydroxybenzoate, phenyl salicylate, cyclohexyl p-hydroxybenzoate, benzyl salicylate, ethyl a-resorcinate, methyl anisate, ethyl anisate, phenyl anisate, benzyl anisate, ethyl o methoxybenzoate, methyl p-ethoxybanzoate, methyl p-toluylate, ethyl p-toluylate, phenyl p-toluylate, ethyl o-toluylate, ethyl m-toluylate, methyl p-aminobenzoate, ethyl p-aminobenzoate, vinyl benzoate, allyl benzoate, benzyl benzoate, methyl naphthoate, and ethyl naphthoate. Alkyl esters, particularly methyl and ethyl esters, of benzoic acid, o- or p-toluic acid and p-anisic acid are especially preferred.

The olefin polymerizing reaction using the catalyst of the present invention is carried out in the same way as in the conventional olefin polymerizing reaction using a Ziegler type catalyst. That is, the reaction is conducted in vapor phase in a substantially oxygen- and water-free condition and in the presence of an inert solvent or by utilizing monomer per se as solvent. Olefin polymerizing conditions involve temperatures ranging from 200 to 3000 C, preferably from 400 to 1 800C, and pressures from atmospheric pressure to 70 kg/cm2 G, preferably 2 to 60 kg/cm2 G.Adjustment of the molecular weight can be made to some extent by changing polymerization conditions such as the polymerization temperature and the catalyst mole ratio, but the addition of hydrogen into the polymerization system is more effective for this purpose. Of course, using the catalyst of the invention there may be performed, without any trouble, two or more multiple stage polymerization reaction involving different polymerization conditions such as different hydrogen concentrations and different polymerization temperatures.

The process of the present invention is applicable to the polymerization of all olefins that are polymerizable with Ziegler type catalyst. For example, it is suitably applied to the homopolymerization of cr-olefins such as ethylene, propylene, 1-butene and 4-methylpentene-1, as well as to random and block copolymerizations of ethylene and propylene, ethylene and 1-butene, propylene and 1-butene.

Copolymerization with dienes for the purpose of modification of polyolefins, for example, copolymerization of ethylene and butadiene, ethylene and 1 ,4-hexadiene, is also preferable.

The process of the present invention is particularly effective in polymerizing or copolymerizing, with high stereospecificity, o'-olefins having 3 to 8 carbon atoms.

The following examples are given to further illustrate the present invention, but it is to be understood that the invention is not limited thereto.

EXAMPLE 1 (a) Preparation of Catalyst Component 10 g. of anhydrous magnesium chloride and 6 ml. of tetraethoxy silane were placed in a stainless steel pot having a content volume of 400 ml. and containing 25 stainless steel balls each 1/2 inch in diameter, and ball-milled for 1 6 hours at room temperature in a nitrogen atmosphere, then 6 g. of anhydrous aluminium trichloride was added followed by further ball milling for 16 hours at room temperature in a nitrogen atmosphere, thereafter 2 ml. of titanium tetrachloride was added and again ball milling was made for 1 6 hours at room temperature in a nitrogen atmosphere, to give a solid powder containing 35 mg. of titanium per gram thereof.

(b) Polymerization A stainless steel 2 liter autoclave equipped with an induction stirrer was purged with nitrogen and charged with 1,000 ml. of hexane, then 5 mmol of triethylaluminium, 1.4 mmol of ethyl benzoate and 100 mg. of the solid powder obtained above were added and the temperature was raised to 500C with stirring. The system was pressurized to 0.5 kg/cm2.G oz G due to the vapor pressure of hexane, then propylene was introduced continuously to a total pressure of 7 kg/cm2G and polymerization was allowed to take place for 1 hour.

Thereafter, excess propylene was discharged, followed by cooling, and the contents were taken out and dried to obtain 1 65 g. of a white polypropylene corresponding to the total amount of product including amorphous polymer.

The catalyst activity was 250 g. polypropylene/g. soli oz solid.hr.C3H6 pressure, 7,300 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solvent- soluble polymer after extraction with boiling n-heptane was 90.2%.

COMPARATIVE EXAMPLE 1 Preparation of a catalyst component and polymerization were made in the same way as in Example 1 except that an hydros aluminium trichloride was not used. As a result, there was obtained only 16 g. of polypropylene.

COMPARATIVE EXAMPLE 2 Preparation of a catalyst component and polymerization were made in the same way as in Example 1 except that tetraethoxy silane was not used. As a result, 80 g. of polypropylene was obtained.

The catalyst activity was 120 g. polypropylene/g. solid hr C3H6 pressure, and the percentage residue of all polymer including solvent-soluble polymer after extraction with boiling n-heptane was 81.3%.

EXAMPLE 2 A solid powder was prepared in the same way as in Example 1 except that 3.6 g. of a 1:1 ,(mol ratio) adduct of titanium tetrachloride and ethyl benzoate was used in place of titanium tetrachloride. It contained 20 mg. of titanium per gram thereof.

Polymerization of propylene was carried out in the same manner as in Example 1 except that 100 mg. of the solid powder just prepared above was used, to yield 104 g. of a white polypropylene.

The catalyst activity was 160 g. polypropylene/g. solid hr. C3H6 pressure, 8,000 g.

polypropylene/g. Ti hr- C3H6 pressure, and the percentage residue of all polymer including solvent- soluble polymer after extraction with boiling n-heptane was 92.5%.

EXAMPLE 3 A solid powder was prepared in the same way as in Example 1 except that 9 ml. of tetraethoxy silane was used. It contained 31 mg. of titanium per gram thereof.

Polymerization of propylene was carried out in the same way as in Example 1 except that 100 mg.

of the solid powder just prepared above was used, to yield 140 g. of a white polypropylene.

The catalyst activity was 220 g. polypropylene/g. solid. hr.C3H6 pressure, 6,900 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 89.5%.

EXAMPLE 4 A solid powder was prepared in the same way as in Example 1 except that 9 g. of anhydrous aluminium chloride was used. It contained 31 mg. of titanium per gram thereof.

Polymerization of propylene was carried out in the same manner as in Example 1 except that 100 mg. of the solid powder just prepared above was used, to yield 1 69 g. of a white polypropylene.

The catalyst activity was 260 g. polypropylene/g. solid.hr.C3H6 pressure, 8,400 g.

polypropylene/g. Ti hr- C3H6 pressure, and the percentage residue of all polymer including solvent- sofuble polymer after extraction with boiling n-heptane was 86.5%.

EXAMPLE 5 A solid powder was prepared in the same way as in Example 1 except that 12 g. of anhydrous aluminium tribromide was used in place of anhydrous aluminium trichloride. It contained 28 mg. of titanium per gram thereof.

Polymerization of propylene was carried out in the same manner as in Example 1 except that 100 mg. of the solid powder just prepared above was used, to yield 121 g. of a white polypropylene.

The catalyst activity was 190 g. polypropylene/g. solid hr C3H6 pressure, 6,600 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 87.6%.

EXAMPLE 6 A solid powder was prepared in the same way as in Example 1 except that 4 ml. of monoethoxy trichlorosilane was used in place of tetraethoxy silane. It contained 36 mg. of titanium per gram thereof.

Polymerization of propylene was carried out in the same manner as in Example 1 except that 100 mg. of the solid powder just prepared above was used, to yield 1 83 g. of a white polypropylene.

The catalyst activity was 280 g. polypropylene/g. solid.hr.C3H6 pressure, 7,800 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including soiventsoluble polymer after extraction with boiling n-heptane was 88.1%.

EXAMPLE 7 A solid powder was prepared in the same way as in Example 1 except that 5 ml. of triethoxy monochlorosilane was used in place of tetraethoxy silane. It contained 35 mg. of titanium per gram thereof.

Polymerization of propylene was carried out in the same manner as in Example 1 except that 1 00 mg. of the solid powder just prepared above was used, to yield 1 74 g. of a white polypropylene.

The catalyst activity was 270 g. polypropylene/g. solid.hr.C3H6 pressure, 7,600 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 89.5%.

EXAMPLE 8 Polymerization of propylene was carried out in the same way as in Example 1 except that 1.4 mmol of ethyl p-anisate and 5.0 mmol of triisobutylaluminium were used in place of ethyl benzoate and triethylaluminium, to yield 160 g. of a white polypropylene.

The catalyst activity was 250 g. polypropylene/g. solid hr C3H6 pressure, 7,000 g.

polypropylene/g. Ti hr- .hr.C3H6 pressure, and the percentage residue of all polymer including solvent- soluble polymer after extraction with boiling n-heptane was 91.3%.

EXAMPLE 9 10 g. of anhydrous magnesium chloride and 6 ml. of tetraethoxy silane were placed in a stainless steel pot having a content volume of 400 ml. and containing 25 stainless steel balls each 1/2 inch in diameter, and ball-milled for 16 hours at room temperature in a nitrogen atmosphere, then 6 g. of anhydrous aluminium trichloride was added followed by further ball milling for 1 6 hours at room temperature in a nitrogen atmosphere. The resultant pulverized product was put into a 300 ml. round bottom flask, then 50 ml. of titanium tetrachloride and 100 ml. of n-heptane were added, followed by stirring for 2 hours at 1 000C. Then, after removing unreacted titanium tetrachloride by washing with nine 100 ml. portions of n-hexane, the reaction product was vacuum-dried to obtain a solid powder containing 43 mg. of titanium per gram thereof.

Polymerization of propylene was carried out in the same way as in Example 1 except that 100 mg.

of the solid powder just prepared above was used, to yield 200 g. of a white polypropylene.

The catalyst activity was 300 g. polypropylene/g. solid hr- C3H6 pressure, 7,200 g. polypropylene/ g. Ti.hr.C3H6 pressure, and the percentage residue of all polymer including solvent-soluble polymer after extraction with boiling n-heptane was 90.5%.

EXAMPLE 10 10 g. of anhydrous magnesium chloride, 6 ml. of tetraethoxy silane and 6 g. of anhydrous aluminium trichloride were placed in a 300 ml. round bottom flask, then 100 ml. of n-heptane was added followed by stirring for 2 hours at 100 C. Thereafter, 50 ml. of titanium tetrachloride was added and stirring was made for 2 hours at 100 C. Then, after removing unreacted titanium tetrachloride by washing with nine 100 ml. portions of n-hexane, the reaction product was vacuum-dried to obtain a solid powder containing 37 mg. of titanium per gram thereof.

Polymerization of propylene was carried out in the same way as in Example 1 except that 100 mg.

of the solid powder just prepared above was used, to yield 1 3 g. of a white polypropylene.

The catalyst activity was 170 g. polypropylene/g. solid hr. C3H6 pressure, 4,600 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 88.9%.

EXAMPLE 11 (a) Preparation of Catalyst Component 10 g. of anhydrous magnesium chloride, 6 ml. of tetraethoxy silane and 4.5 g. of benzoic anhydride were placed in a stainless steel pot having a content volume of 400 ml. and containing 25 stainless steel balls each 1/2 inch in diameter, and ball-milled for 16 hours at room temperature in a nitrogen atmosphere, then 6 g. of anhydrous aluminium trichloride was added followed by further ball milling for 1 6 hours at room temperature in a nitrogen atmosphere, thereafter 2 ml. of titanium tetrachloride was added and again ball milling was made for 16 hours at room temperature in a nitrogen atmosphere to obtain a solid powder containing 30 mg. of titanium per gram thereof.

(b) Polymerization A stainless steel 2 liter autoclave equipped with an induction stirrer was purged with nitrogen and charged with 1 ,000 ml. of hexane, then 5 mmol of triethylaluminium, 1.4 mmol of ethyl benzoate and 100 mg. of the solid powder prepared above were added and the temperature was raised to 500C with stirring. The system was pressurized to 0.5 kg/cm2. G due to the vapor pressure of hexane, then propylene was introduced continuously to a total pressure of 7 kg/cm2G and polymerization was allowed to take place for 1 hour.

Thereafter, excess propylene was discharged, followed by cooling, and the contents were withdrawn and dried to obtain 11 7 g. of a white polypropylene corresponding to the total amount of product including amorphous polymer.

The catalyst activity was 180 g. polypropylene/g. solid hr- C3H6 pressure, 6,000 g.

polypropylene/g. Ti hr- C3H6 pressure, and the percentage residue of all polymer including solvent- soluble polymer after extraction with boiling n-heptane was 93.5%.

COMPARATIVE EXAMPLE 3 A catalyst component was prepared in the same way as in Example 11 except that tetraethoxy silane was not used. The resulting solid powder proved to contain 36 mg. of titanium per gram thereof.

Polymerization of propylene was conducted in the same manner as in Example 11 except that 100 mg. of the solid powder just prepared above was used, to yield 73 g. of a white polypropylene.

The catalyst activity was 110 g. polypropylene/g. solid.hr.C3H6 pressure, 3,100 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 83.4%.

COMPARATIVE EXAMPLE 4 A catalyst component was prepared in the same way as in Example 11 except that anhydrous aluminium trichloride was not used. The resulting solid powder proved to contain 37 mg. of titanium per gram thereof.

Polymerization of propylene was conducted in the same manner as in Example 11 except that 100 mg. of the solid powder just prepared above was used, to afford 34 g. of a white polypropylene.

The catalyst activity was 53 g. polypropylene/g. solid hr- C3H6 pressure, 1,400 g. polypropylene/g.

Ti hr- C3H6 pressure, and the percentage residue of all polymer including solvent-soluble polymer after extraction with boiling n-heptane was 85.1%.

EXAMPLE 12 A catalyst component was prepared in the same way as in Example 11 except that 6 g. of 1:1 (mol ratio) adduct of titanium tetrachloride and ethyl benzoate was used in place of titanium tetrachloride.

The resulting solid powder proved to contain 26 mg. of titanium per gram thereof.

Polymerization of propylene was conducted in the same manner as in Example 11 except that 100 mg. of the solid powder just prepared above was used, to afford 99 g. of a white polypropylene.

The catalyst activity was 150 g. polypropylene/g. solid hr C3He pressure, 5,900 g.

polypropylene/g. Ti hr. C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 94.4%.

EXAMPLES 13-17 Catalyst components were prepared in the same way as in Example 11 except that components (1) through (4) as shown in Table 1 below were used, and polymerization of propylene was conducted in the same manner as in Example 11, the results of which are as set out in the same table.

TABLE 1

Catalyst Activity Percentage residue g. polypropylene Amount of Amount of Amount of Amount of Amount of of all polymer Component Component Component Component Ti supported # # after extraction with Example (1) (2) (3) (4) (mg/g. solid) g.solid.hr.C3H6 pressure boiling n-heptane (%) 13 MgCl2 Si(OC2H5)4 AlCl3 (C6H5CO)2O 27 150 92.7 10 g. 9 ml. 6 g. 4.5 g 14 MgCl2 Si(OC2H5)4 AlCl3 (C6H5CO)2O 27 190 91.6 10 g. 6 ml. 9 g. 4.5 g.

15 MgCl2 Si(OC2H5)4 AlCl3 (C6H5CO)2O 27 150 94.0 10 g. 6 ml. 6 g. 6.8 g.

16 MgCl2 Si(OC2H5)4 AlBr3 (C6H5CO)2O 25 130 93.0 10 g. 6 ml. 12 g. 4.5 g.

17 MgCl2 Si(OC2H5)3Cl AlCl3 (CH3CO)2O 34 190 92.1 10 g. 5 ml. 6 g. 0.7 ml.

EXAMPLE 18 Polymerization of propylene was conducted in the same way as in Example 11 except that 1.4 mmol of ethyl p-anisate and 5.0 mmol of triisobutylaluminium were used in place of ethyl benzoate and triethylaluminium, to afford 11 5 g. of a white polypropylene.

The catalyst activity was 180 g. polypropylene/g. solid hr. C3H6 pressure, 5,900 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 93.8%.

EXAMPLE 19 10 g. of anhydrous magnesium chloride, 6 ml. of tetraethoxy silane, 6 g. of anhydrous aluminium trichloride and 4.5 g. of anhydrous benzoic acid were placed in a 300 ml. round bottom flask, then 100 ml. of n-heptane was added followed by stirring for 2 hours at 100 C. Thereafter, 50 ml. of titanium tetrachloride was added and stirring was made for 2 hours at 100 C. Then, after removing unreacted titanium tetrachloride by washing with nine 100 ml. portions of n-hexane, the reaction product was vacuum-dried to obtain a solid powder containing 38 mg. of titanium per gram thereof.

Polymerization of propylene was conducted in the same way as in Example 11 except that 1 00 mg. of the solid powder just prepared above was used, to afford 151 g. of a white polypropylene.

The catalyst activity was 230 g. polypropylene/g. solid hr C3H6 pressure, 6,100 g.

polypropylene/g. Ti hr C,H, C3H6 pressure, and the percentage residue of all polymer including solvent- soluble polymer after extraction with boiling n-heptane was 94.2%.

EXAMPLE 20 (a) Preparation of Catalyst Component 10 g. of anhydrous magnesium chloride, 6 ml. of tetraethoxy silane and 1.5 ml. of benzoyl chloride were placed in a stainless steel pot having a content volume of 400 ml. and containing 25 stainless steel balls each 1/2 inch in diameter, and ball-milled for 16 hours at room temperature in a nitrogen atmosphere, then 6 g. of anhydrous aluminium trichloride was added followed by further ball milling for 16 hours at room temperature in a nitrogen atmosphere, thereafter 2 ml. of titanium tetrachloride was added and again ball milling was made for 16 hours at room temperature in a nitrogen atmosphere, to give a solid powder containing 32 mg. of titanium per gram thereof.

(b) Polymerization A stainless steel 2 liter autoclave equipped with an induction stirrer was purged with nitrogen and charged with 1,000 ml. of hexane, then 5 mmol of triethylaluminium, 1.4 mmol of ethyl benzoate and 100 mg. of the solid powder prepared above were added and the temperature was raised to 500C with stirring. The system was pressurized to 0.5 kg/cm2.G due to the vapor pressure of hexane, then propylene was introduced continuously to a total pressure of 7 kg/cm2.G and polymerization was allowed to take place for 1 hour.

Thereafter, excess propylene was discharged, followed by cooling, and the contents were withdrawn and dried to obtain 132 g. of a white polypropylene corresponding to the total amount of product including amorphous polymer.

The catalyst activity was 200 g. polypropylene/g.solid.hr.C3H6 pressure, 6,300 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 93.0%.

COMPARATIVE EXAMPLE 5 A catalyst component was prepared in the sarne way as in Example 20 except that anhydrous aluminium trichloride was not used. The resulting solid powder proved to contain 42 mg. of titanium per gram thereof.

Polymerization of propylene was conducted in the same manner as in Example 20 except that 100 mg. of the solid powder just prepared above was used, to afford 53 g. of a white polypropylene.

The catalyst activity was 82 g. polypropylene/g. solid hr. C3H6 pressure, 1,900 g. polypropylene/g.

Ti hr C3H6 pressure, and the percentage residue of all polymer including solvent-soluble polymer after extraction with boiling n-heptane was 85.8%.

COMPARATIVE EXAMPLE 6 A catalyst component was prepared in the same way as in Example 20 except that tetraethoxy silane was not used. The resulting solid powder proved to contain 41 mg. of titanium per gram thereof.

Polymerization of propylene was conducted in the same manner as in Example 20 except that 100 mg. of the solid powder just prepared above was used, to afford 93 g. of a white polypropylene.

The catalyst activity was 140 g. polypropylene/g.solid.hr.C3H6 pressure, 3,500 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 83.1%.

EXAMPLE 21 A catalyst component was prepared in the same way as in Example 20 except that 4.0 g. of a 1: (mol ratio) adduct of titanium tetrachloride and ethyl benzoate was used in place of titanium tetrachloride. The resulting solid powder proved to contain 21 mg. of titanium per gram thereof.

Polymerization of propylene was conducted in the same manner as in Example 20 except that 100 mg. of the solid powder just prepared above was used, to afford 87 g. of a white polypropylene.

The catalyst activity was 130 g. polypropylene/g. solid hr C3H6 pressure, 6,400 g.

polypropylene/g. Ti hr- C3H6 pressure, and the percentage residue of all polymer including solvent- soluble polymer after extraction with boiling n-heptane was 94.1%.

EXAMPLES 22-27 Catalyst components were prepared in the same way as in Example 20 except that components (1) through (4) shown in Table 2 belo N were used, and polymerization of propylene was conducted in the same manner as in Example 20, the results of which are as set out in the same table.

TABLE 2

Catalyst Activity Percentage residue g. polypropylene Amount of Amount of Amount of Amount of Amount of of all polymer Component Component Component Component Ti supported # # after extraction with Example (1) (2) (3) (4) (mg/g.solid) g.solid.hr.C3H6 pressure boiling n-heptane (%) 22 MgCl2 Si(OC2H5)4 AlCl3 C6H5COCl 29 210 91.1 10 g. 6 ml. 9 g. 1.5 ml.

23 MgCl2 Si(OC2H5)4 AlCl3 C6H5COCl 30 170 93.5 10 g. 6 ml. 9g. 3 ml.

24 MgCl2 Si(OC2H5)4 AlCl3 C6H5COCl 29 180 92.4 10 g. 9 ml. 6 g. 1.5 ml.

25 MgCl2 Si(OC2H5)4 AlBr3 C6H5COCl 27 150 92.1 10 g. 6 ml. 12 g. 1.5 ml.

26 MgCl2 Si(OC2H5)4 AlCl3 C6H5COCl 33 230 91.8 10 g. 5 ml. 6 g. 1.5 ml.

27 MgCl2 Si(OC2H5)4 AlCl3 CH3COCl 34 190 91.4 10 g. 6 ml. 6 g. 0.7 ml.

EXAMPLE 28 Polymerization of propylene was conducted in the same way as in Example 20 except that 1.4 mmol of ethyl p-anisate and 5.0 mmol of triisobutylaluminium were used in place of ethyl benzoate and triethylaluminium, to afford 130 g. of a white polypropylene.

The catalyst activity was 200 g. polypropylene/g. solid hr C3H6 pressure, 6,300 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 93.8%.

EXAMPLE 29 10 g. of anhydrous magnesium chloride, 6 ml. of tetraethoxy silane, 6 g. of anhydrous aluminium trichloride and 1.5 ml. of benzoyl chloride were placed in a 300 ml. round bottom flask, then 100 ml. of n-heptane was added followed by stirring for 2 hours at 100 C. Thereafter, 50 ml. of titanium tetrachloride was added and stirring was made for 2 hours at 100 C. Then, after removing unreacted titanium tetrachloride by washing with nine 100 ml. portions of n-hexane, the reaction product was vacuum-dried to obtain a solid powder containing 35 mg. of titanium per gram thereof.

Polymerization of propylene was conducted in the same way as in Example 20 except that 100 mg. of the solid powder just prepared above was used, to afford 108 g. of a white polypropylene.

The catalyst activity was 170 g. polypropylene/g. solid hr. C3H6 pressure, 4,700 g.

polypropylene/g. Ti hr C3H6 pressure, and the percentage residue of all polymer including solventsoluble polymer after extraction with boiling n-heptane was 92.6%.

Claims (14)

1. A process for preparing a polyolefin, characterized by polymerizing at least one olefin in the presence of a catalyst, said catalyst comprising a combination of a solid catalyst component with a mixture or addition compound of an organometallic compound and an organic acid ester, said catalyst component being obtained by supporting on a solid substance a titanium compound and/or an addition compound of a titanium compound and an organic acid ester, said solid substance being obtained by contacting and reacting the following components: (1) a magnesium halide, (2) a compound represented by the general formula Si(OR)mX4~m wherein R is a hydrocarbon radical having 1 to 24 carbon atoms, X is a halogen atom and m is O < m < = 4, and (3) an aluminium halide.

2. A process for preparing a polyolefin, characterized by polymerizing at least one olefin in the presence of a catalyst, said catalyst comprising a combination of a solid catalyst component with a mixture or addition compound of an organometallic compound and an organic acid ester, said catalyst component being obtained by supporting on a solid substance a titanium compound and/or an addition compound of a titanium compound and an organic acid ester, said solid substance being obtained by contacting and reacting the following components: (1) a magnesium halide, (2) a compound represented by the general formula Si(OR)mX4~m wherein R is a hydrocarbon radical having 1 to 24 carbon atoms, X is a halogen atom and m is O < m < = 4, (3) an aluminium halide and (4) an organocarboxylic acid anhydride and/or an organocarboxylic acid halide.

3. A process according to claim 2, wherein the ratio of said component (1) to said component (4) is in the range of 1:0.001 to 1:10 in terms of molar ratio.

4. A process according to claim 1,2 or 3, wherein the ratio of said component (1) to said component (2) is in the range of 1:0.001 to 1:10 in terms of molar ratio.

5. A process according to any one of claims 1 to 4, wherein the ratio of said component (1) to said component (3) is in the range of 1:0.001 to 1:10 in terms of molar ratio.

6. A process according to any one of claims 1 to 5, wherein said organometallic compound is an organoaluminium compound or an organozinc compound.

7. A process according to any one of claims 1 to 6, wherein said olefin is an st-olefin having 3 to 8 carbon atoms.

8. A process according to any one of claims 1 to 7, wherein the polymerization reaction is carried out at a temperature in the range of 200 to 3000C and at a pressure in the range of atmospheric pressure to 70 kg/cm2 G.

9. A process as claimed in claim 1, substantially as hereinbefore described with particular reference to the Examples.

10. A process as claimed in claim 1, substantially as illustrated in any one of the Examples.

11. An olefin polymerization catalyst as defined in any one of claims 1 to 6.

12. An olefin polymerization catalyst substantially as hereinbefore described with particular reference to the Examples.

1 3. An olefin polymerization catalyst, substantially as illustrated in any one of the Examples.

14. An olefin polymer when prepared by the process claimed in any one of claims 1 to 10.