GB2321462A - Process for the polymerisation and copolymerisation of olefins - Google Patents

Abstract

An improved catalytic process and catalytic system for polymerization and copolymerization of olefins having a high bulk density. A solid titanium catalyst is used in the preferred embodiment of the catalytic system, the making of the catalyst is disclosed as part of the catalytic process. The solid titanium catalyst of the preferred embodiment is made using a magnesium compound solution in a mixed solvent of cyclic ether and alcohol. The catalyst is precipitated via a reaction with a transition metal compound. The precipitate is then reacted with a transition metal compound and an internal electron donor. Polymerization is accomplished using the catalyst and a cocatalyst, an organometallic compound, along with an external electron donor in the catalytic system. The magnesium compound may be MgCl 2 ; the transition metal compound may be TiCl 4 ; the internal electron donor may be diisobutyl phthalate; the external electron donor may be cyclohexylmethyl-dimethoxysilane; and the organometallic compound may be triethylaluminium.

Description

SPECIFICATION TITLE OF THE INVENTION An improved process for polymerization and copolymerization of olefins.

FIELD OF THE INVENTION The present invention relates to a process for polymerization and copolymerization yielding olefins having a high bulk density, wherein the process uses a solid titanium complex catalyst having high polymerization activity.

BACKGROUND OF THE INVENTION Use of catalytic systems for polymerization suffers from inefficiencies in process and undesirable characteristics of the product One challenge has been to invent a simple catalyst which nonetheless can be used to produce a high quality polymer having high bulk density, excellent fluidity and high stereo regularity.

Another challenge is the need to remove the residue of the catalyst from the product.

Finally, production of the catalyst must be itself relatively quick and inexpensive.

Numerous olefin polymerization catalysts containing magnasium and based on titanium and production processes utilizing them have been reported, but without significant breakthroughs in attempting to achieve higher bulk densities.

Methods which make use of magnesium solutions are knon. For instance, a method is known to obtain a magnesium solution by reacting a megnesium compound, in the presence of a hydrocarbon solvent, with such electron donors as alcohol, cyclic ether, carboxy oxides, etc. Use of alcohol as electron donor is mentioned in USPs 4,330,649 and 5,106,870, and Japanese Patent Pub. Sho 58-83006. In USPs 4,315,874, 4,399,054, 4,071,674, and 4,439,540, methods are also reported for production of magnesium solutions. Use of a silicon compound as a constituent of the catalyst for obtainment of solid catalyst components from magnesium solutions has been described in USPs 4,071,672, 4,085,276, 4,220,554, 4,315,835, etc.

USPs 4,946,816, 4,866,022, 4,988,656, 5,013,702, and 5,124,297 are all mutually related, and the processes for producing catalysts in these patents comprise (i) making a solution containing magnesium from magnesium caboxylate or magnesium alkylcarbonate, (ii) precipitating magnesium in the presence of transition metal halide and organosilane, (iii) reprecipitating the once precipitated solid components by the use of a mixed solution containing tetrahydrofuran, and (iv) producing a catalyst of uniform granularity by reacting the reprecipitated granules with transition metal compounds and electron donor compounds. But these processes have the problems of both having too many steps in producing a catalyst, and having production processes which are themselves a little too complicated, without producing olefins of the highest quality.

The Japanese Patent Pub. Sho 63-54004 and USP 4,330,649 describe processes, in which the magnesium solution is produced by reacting a magnesium compound with more than one member of the group consisting of alcohol, organic carboxylic acid, aldehyde, and amine in the presence of organic hydrocarbon solvent, with the final catalytic component being produced by reaction of the above solution with titanium compounds and an electron donor. All of these processes however, suffer from typical problems. They are either too complex, produce polymers with undesirable characteristics, or both.

SUMMARY OF THE INVENTION The present invention improves upon the cited references by providing a new catalytic system. In the improved catalytic system, a mixed solvent of cyclic ether and alcohol is used in preparation of the solid titanium complex catalyst. The catalytic system also includes an organometallic compound and an electron donor in addition to the catalyst. The polymers produced by the means of this improved process possess high bulk density, excellent fluidity, and the degree of stereo regularity is high enough that there is no need to remove irregular polymers. The process itself has a high yield so the catalyst need not be removed after production, and the production of the catalyst is relatively easy.

The use of a mixture of cyclic ether and alcohol in the production of the catalyst is itself an inexpensive and easy process, thus contributing further to the ease of production.

Therefore, one objective of the present invention is to provide a process for olefin polymerization and copolymerization by the use of a catalyst, which can be produced by a much easier production process than known and proposed processes.

Another objective of the present invention is to provide a process for olefin polymerization and copolymerization using a magresium-supported titanium catalyst by which a polymer having high bulk density can be produced.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a process for olefin polymerization and copolymerization using a solid titanium complex catalyst produced by a simple yet efficacious method comprising threes steps: (i) producing a solution containing magnesium (a magnesium compound solution) from a non-reductive magnesium compound; (ii) precipitating the solid components by reacting said magnesium compound solution with a transition metal compound; and (iii) reacting the precipitated solid components with a transition metal compound again and an internal electron donor. As will be detailed below, the mixed solvent of cyclic ether and alcohol is used is step (i) above. Thereafter, the solid catalyst is washed with a hydrocarbon solvent.

Examples of non-reductive magnesium compounds used in step (i) above include such magnesium halides as magnesium chloride, magnesium iodide, magnesium fluoride, and magnesium bromide; such alkylmagnesium halides as methylmagnesium halide, ethylmagnesium halide, propylmagnesium halide, butylmagnesium halide, isobutylmagnesium halide, hexylmagnesium halide, amylmagnesium halide; such alkoxymagnesium halides as methoxymagnesium halide, ethoxymagnesium halide, isopropoxymagnesium halide, butoxymagnesium halide, and octoxymagnesium halide; such aryloxymagnesium halides as phenoxymagnesium halide and methylphenoxymagnesium halide; such alkoxymagnesiums as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, and octoxymagnesium; such aryloxymagnesiums as phenoxymagnesium and dimethylphenoxymagnesium; and such magnesium carboxylates as laurylmagnesium and magnesium stearate. Such magnesium compounds can also be effective when used in the form of complex compounds with other metals.

Although the above compounds can usually be represented in simple formulae, yet on some occasions they can not, depending upon the various methods for production. For instance, such compounds can also be used in the present invention as are obtained from reaction of magnesium compounds with polysiloxane compounds, silane compounds containing halogen, ester, alcohol, etc. Such compounds as are obtained from reaction of magnesium metals with alcohol, phenol, or ether in the presence of halosilane, phosphorus pentachloride, or thionyl chloride can also be used. The preferable magnesium compounds are magnesium halides, especially magnesium chloride and alkylmagnesium chloride, in which the alkyl group preferably has from one to ten carbon atoms; alkoxymagnesium chloride, in which the alkoxy group preferably has from one to ten carbon atoms; and aryloxymagnesium chloride, in which the aryloxy group preferably has from six to twenty carbon atoms.

In step (i), the magnesium compound solution can be produced by dissolving the aforesaid magnesium compounds in a solvent of a mixture of alcohol and cyclic ether either in the presence or absence of a hydrocarbon solvent. The hydrocabon solvents used at this stage include such aliphatic hydrocarbons as pentane, hexane, heptane, octane, decane, and kerosene; such cycloaliphatic hydrocarbons as cyclobenzene, methylcyclobenzene, cyclohexane, and methylcyclohexane; such aromatic hydrocarbons as benzene, toluene, xylene, ethylbenzene, cumene, and cymene; such halogenated hydrocarbons as dichloropropane, dichloroethylene, trichloroethylene, carbon tetrachloride, and chlorobenzene.

When producing a magnesium compound solution, a mixture of alcohol and cyclic ether is used as a solvent. By the use of such a mixed solvent, magnesium compounds can be the more easily turned into a solution than by the use of any one single solvent. For the alcohol, such ones can be used as methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, decanol, dodecanol, octadecylalcohol, benzilalcohol, phenylalcohol, isopropylbenzilalcohol, cumyl alcohol, which are all alcohols that contain one to 20 carbon atoms, the more preferable being those containing one to 12 carbon atoms. For cyclic ethers, tetrahydrofuran, 2-methyl tetrahydrofuran, tetrahydropyran can be used, but the preferable cyclic ether is tetrahydrofuran. The total quantity of the cyclic ether and alcohol for use here is at least 0.5mol per lmol of magnesium compound, preferably about 1 20mol, more preferably about 2-10mol, while the mol ratio of the cyclic ether and the alcohol is preferably between 1: 0.05 to 1: 0.95.

The temperature for reaction of the magnesium compound and the mixture of alcohol and cyclic ether vary according to the kinds and quantity of the alcohol and cyclic ether, from - 25 C to 200 C, preferably about - 10 C to 200 C, most preferably about 0 C to 150 C. The reaction is performed for a period of time ranging from 15 minutes to five hours, preferably for about 30 minutes to three hours.

In step (ii) above, the magnesium compound solution produced in step (i) is crystallized into solid form by reacting it with a transition metal compound, e.g. a titanium compound in liquid form. This transition metal compound can be represented by a general formula: Ti(OR)aX4a (R being a hydrocarbon group, X halogen atoms, "a" the number oil14). In the preferred embodiment, R is an alkyl group having one to 10 carbon atoms. The kind of titanium compounds to satisfy the above formula may include, for example, such titanium tetrahalides as Tic4, TiBr4, Tit4; such trihalo alkoxytitanium compounds as Ti(OCH,)Cl3, Ti(OC2H5)Cl3, Ti(OC2H5)Br3, and Ti(O(i-C4Hg)Br3; such dihalo alkoxytitanium compounds as Ti(OCH3)2Cl2, Ti(OC2H5)2Cl2, Ti(O(i-C4H9)2C12, and Ti(OC2H5)2Br2; such tetraalkoxytitanium as Ti(OCH3)4, Ti(OC2H5)4, and Ti(OC4H9)4. Mixtures of these titanium compounds can also be used in the present invention. The preferable titanium compounds are titanium compounds containing halogen, and the most preferable is titanium tetrachloride.

The magnesium compound solution can also be crystallized in solid matter by the use of silicone compounds, e.g. silicone tetrahalide and silicone alkylhalide, tin compounds, e.g tin tetrahalide, tin alkylhalide, and tin hydrohalide, or their mixtures, or even mixtures of these and the titanium compounds.

The quantity of the titanium compounds, silicon compounds, tin compounds, or their mixtures used when crystallizing the magnesium compound solution is appropriately 0.1mol to 200mol to lmol of the magnesium compound, preferably 0.1mol to 100mol, and most preferably 0.2mol to SOmol. The shape and size of the crystallized solid components, as well as their granular distribution, depend upon the conditions of the reaction of the magnesium compound solution with the titanium compounds, silicon compounds, tin compounds, or with their mixtures, and thus are varied. The reaction of the magnesium compound solution with titanium compounds, silicon compounds,tin compounds, or with their mixtures is made to take place at sufficiently low temperatures that the solid matter does not form very quickly but takes time gradually crystallizing.

Preferable temperatures are - 70 C to 70 C for a contact reaction, more preferably - 50 C to 50 C. After the contact reaction, the temperature in the preferred embodiment is raised and the reaction left to continue at 50 C to 150 C for 0.5 hours to five hours.

In Step (iii), reacting the solid components with transition metal compounds such as a titanium compound in the presence of a proper internal electron donor produces a catalyst. In the preferred embodiment, this reaction proceeds in two phases: e.g., the first phase is reacting the solid components with either a titanium compound alone or a titanium compound and internal electron donor together. The second phase is separating the solid components and reacting them one more time with a titanium compound and internal electron donor, separating the solid components again, and drying them, thereby obtaining the desired catalyst. Another embodiment reacts the solid components obtained in Step (ii) and a titanium compound either in the presence or absence of hydrocarbon or halogenated hydrocarbon for a certain length of time and then adding an internal electron donor thereto afterwards.

The transition metal compounds adequate for use in Step (iii) above are titanium compounds, especially titanium halides and such haloalkoxy titanium whose alkoxy functional group has one to 20 carbon atoms, or mixtures thereof.

Preferable among these are titanium halides or halogenated alkoxytitanium in which the functional group has one to eight carbon atoms. Most preferable is titanium tetrahalide.

The internal electron donors adequate for use in step (iii) above include compounds containing oxygen, nitrogen, sulphur, and phosphorus. Examples of such compounds include organic acids, organic acid esters, alcohols, ethers, aldehydes, ketones, amines, amine oxides, amide, phosphoric acid ester, and their mixtures.

Especially preferable as internal electron donor are the aromatic esters. Benzoic acid alkyl esters and halobenzoic acid esters such as methyl benzoate, methyl bromobenzoate, ethyl benzoate, ethyl chlorobenzoate, ethylbromo benzoate, butyl benzoate, isobutyl benzoate, hexyl benzoate, and cyclohexyl benzoate; and such dialkylphthalates as diisobutylphthalate, diethylphthalate, ethylbutylphthalate, dibutylphthalate which have two to 10 carbon atoms are also usable. These internal electron donors can also be used in a mixture of two or more. Also, they are usable in the form of an additive to other compounds, or in a complex with other compounds. The quantity of these internal electron donors, in use, can vary: about 0.01 mol to 1 Omol to 1 mol of the magnesium compound, preferably 0.01 mol to Smol, and most preferably 0.05 mol to 2mol.

The solid titanium complex catalyst produced by the method described above is profitably utilized in polymerization of such olefins as ethylene and propylene. It is especially good in polymerization of a-olefins having more than three carbon atoms such as propylene, 1 -butene, 1 -pentene, 4-methyl-l-pentene, 1hexene; copolymerization between these; copolymerization of propylene and ethylene or other a-olefins of less than 20mol; and copolymerization of polyunsaturated compounds like conjugated or nonconjugated diens.

The polymerization and copolymerization of olefins according to the present invention is performed with the use of a catalyst system consisting of (a) the solid titanium complex catalyst, produced in the way given in the present invention, as main catalyst, (b) organometallic compounds as cocatalyst, and (c) organosilicon compounds, particularly dicyclopentyldimethoxysilane or diisobutyldimethoxysilane, as external electon donor.

The solid titanium complex catalyst component (a) of the present invention can also be preliminarily polymerized with an olefin, before being put to use for the reaction for polymerization of the present invention. This preliminary polymerization is performed by reacting the aforesaid catalyst component with organoaluminum compounds like triethylaluminum in the presence of a hydrocarbon such as hexane at sufficiently low temperature and pressurized by a-olefin in the presence or absence of electron donors constituted of organosilicon compounds.

Preliminary polymerization of the catalyst, by encircling the catalyst granules with polymers and thereby maintaining the shape of the catalysts, allows the production of a better-shaped polymer. Activity of the catalyst or evenness of its granules also improves. The ratio in weight of polymer to catalyst after the preliminary polymerization is generally from 0.1:1 to 20:1.

The organometallic compound (b) useful in the process of polymerization in the present invention can be represented by a general formula of MRn, wherein M represents metallic components such as belong to Group II or IIIA on the periodic table of elements (e.g. magnesium, calcium, zinc, boron, aluminum, gallium etc.), R represents an alkyl group having one to 20 carbon atoms (such as a methyl, ethyl, butyl, hexyl, octyl, or decyl group), while represents the valence of the metallic components. As the most preferable organometallic compound, a trialkyl aluminum like triethyl aluminum and triisobutyl aluminum having one to six carbon atoms or their mixtures can be used. At times, organoaluminum compounds having one or more halogen or hydride groups such as ethylaluminum dichloride, diethylaluminum chloride, ethylaluminum sesquichloride, diisobutylaluminum hydride can also be used.

In the present invention, as the external electron donors (c) such organosilicon compounds as diphenylmethoxysilane, phenyltrimethoxysilane, phenylethyldimethoxysilane, phenylmethyldimethoxysilane, isobutyltrimethoxysilane, diisobutyldimethoxysilane, diisopropyldimethoxysilane, di-t-butylmethoxysilane, t-butyltrimethoxysilane, cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, 2-norbornanetriethoxysilane, 2norbornanemethyldimethoxysilane, and a mixture thereof can be used.

The polymerization can be performed by gas or bulk polymerization methods in the absence of organic solvents, or else by liquid slurry polymerization methods in the presence of an organic solvent. Polymerization is performed in the absence of oxygen, water, or other chemical compounds which may act as a catalyst poison. In the case of liquid slurry polymerization the preferable concentration of solid titanium complex catalyst (a) is, in terms of the titanium atoms in the catalyst, from 0.001mmol to Smmol per one litre of the solvent, preferably 0.001 mmol to 0.5mmol. For the solvents such alkanes as pentane, hexane, heptane, n-octane, and isooctane, cyclohexane, and methylcyclohexane, and such alkylaromatics as cycloalkane, toluene, xylene, ethylbenzene, isopropylbenzene, ethyltoluene, npropylbenzene, and diethylbenzene, and such aromatic halides as chlorobenzene, chloronaphthalene, and orthodichlorobenzene, and also their mixtures are useful.

In the case of gas polymerization, the quantity of the solid titanium complex catalyst (a) is, in terms of the titanium atoms in the catalyst, from 0.001mmol to Smmol per one litre of the object of polymerization, preferably 0.001mmol to l.Ommol, and most preferably 0.Olmmol to 0.5mmol.

The preferable concentration of the organometallic compound (b), in terms of alminum atoms, is from 1 mol to 2000mol per one mol of titanium atoms in the catalyst (a), preferably about 5mol to 500mol; while the preferable concentration of the organosilicon compound (c), in terms of silicon atoms, is from 0.001mol to 40mol per one mol of the aluminum atoms in the organometallic compound (b), preferably about 0.05mol to 30mol.

In order to secure a high rate in polymerization, the reaction is to take place at high temperatures regardless of polymerization method. Generally, temperatures between 20 C and 200 e C are adequate, preferably between 20 C and 95 C.

The monomer's pressure at the time of polymerization is appropriately between the ambient pressure and 100 atmospheres of pressure, more appropriately two to 50 atmospheres of pressure.

In the present invention additives can be used at times in order to adjust the molecular weights in the polymer produced. A usual additive is hydrogen, and use of this can be decided upon in the way generally known in the field.

The polymer produced by the process of the present invention is solid isotactic poly a-olefin, and it has several advantages: the yield of polymer is sufficiently high that there is no need for removal of the residues of the catalyst, and the stereo regularities are excellent and so spare the trouble of deliberately removing irregular polymers. The polymer produced by the process of the present invention has high bulk density and excellent fluidity alike.

The present invention is described in detail, reference being made to the examples of embodiment and the examples of comparison. Notwithstanding this, the scope of the present invention is not confined to these examples alone. Other equivalent embodiments are possible without departing the scope of the present invention. The invention has been disclosed in detail to allow enablement, but nothing in this disclosure limits or changes the scope of the claims of this invention.

[Example 1] The solid titanium complex catalyst used in the process for polymerizatin of olefin was produced through the three steps given below: Step (i) Production of the magnesium compound solution In a 1 .0L reactor equipped with a mechanical stirrer, filled with a nitrogenous atmosphere, a mixture of 15g of MgCl2 and 450ml of toluene was poured. It was stirred at 400rpm. Then 100ml of tetrahydrofuran and 26.6m1 of butanol were added thereto, the temperature was raised to 105 C, and the mixture was left to react for three hours. The resulting homogeneous solution was cooled to ambient temperature.

Step (ii) Production of the solid components The aforesaid magnesium solution was transferred to a 1.6L reactor kept at 15 C - 27 C. It was stirred at 350 rpm, and to it 20ml of TiCl4 was added, and the temperature of the reactor was raised to 90 C. During the process the solid components were formed. The reaction was allowed to continue at 90 C for an hour, then stirring was stopped and the formed solid components were left to settle down. The supernatant was separated and the remaining solid components were washed twice with 75ml of toluene each wash.

Step (iii) Production of the catalyst To the previously produced solid components 92ml of toluene and 87ml of Tics4 were added, and the temperature of the reactor was adjusted to 70 C. At this tempreature, 1.7ml of diisophthalate was added, the temperature of the reactor raised to 100 C, and the mixture was heated for one hour while stirring. At the end of the hour, stirring was stopped, the solid components left to settle down, and the supernatant separated. To the solid components 92ml of toluene and 87ml of TiCl4 were added, and at 70 C 1.0ml of diisophthalate was added thereto. After the temperature of the reactor was raised to 105 o C, stirring was continued for a further one hour. Stirring was stopped, the supernatant separated, 92ml of toluene added, the temperature of the reactor lowered to 70 C, stirring continued for another half an hour. After reaction, the stirring was ceased, the supernatant separated, 87ml of TiCl4 added, stirring resumed and continued at 70 C for a final half an hour. The catalyst produced this way was washed five times with 75ml of refined hexane each wash. The catalyst then was dried in a nitrogen atmosphere and stored away.

Polymerization A two-litre reactor was dried in an oven and assembled in a heated condition, and a vial containing 38mg of the catalyst was set in the reactor. The inside of the reactor was filled with a nitrogen atmosphere by application alternately of nitrogen and vacuum three times. Then 1,000ml of n-hexane was put in the reactor, and afterwards 1 Ommol of triethylaluminum and, as external electron donor, 1 Ommol of cyclohexylmethyldimethoxysilane. After applying 20psi of propylene pressure, and breaking the vial of the catalyst with the agitator, polymerization was performed at ambient temperature for five minutes, stirring continuing at 630 rpm.

100ml of hydrogen was added, the temperature of the reactor raised to 70 C, and the pressure of the propylene was adjusted to 100psi, while polymerization was continued for an hour. After the polymerization was finished, the temperature of the reactor was lowered to ambient temperature, and ethanol solution by an amount in excess was added. The polymer thus produced was collected separately, and dried in a vacuum oven at 50 C for six hours, to obtain polypropylene in the form of white powder.

The polymerization activity (kg of polypropylene to g of catalyst) was calculated in terms of the weight (kg) of the yield of polymer in proportion to the weight (g) of the catalyst used therein, the stereoregularity (%) of the polymer calculated in terms of the weight (g) of the polymer which was not extracted during boiling in n-heptane for six hours.

[Example 2] For production of the magnesium compound solution in Step (i) in Example 1, 150ml of tetrahydrofuran was used; for production of the solid components in Step (ii) 30ml of TiCl4 was used; otherwise the process was the same as in Example 1. The results thereof are given in Table I.

[Example 3] For production of the magnesium compound solution in Step (i) in Example 1, 30ml of tetrahydrofuran and 29ml of butanol were used; for production of the solid components in Step (ii) 14.4ml of TiCl4 was used; otherwise the process was the same as in Example 1. The results thereof are given in Table I.

[Example 4] For production of the magnesium compound solution in Step (i) in Example 1, 30ml of tetrahydrofuran and 15.4ml of ethanol were used; for production of the solid components in Step (ii) 14.4ml of TiCl4 was used; otherwise the process was the same as in Example 1. The results thereof are given in Table I.

[Example 5] For production of the magnesium compound solution in Step (i) in Example 1 100ml of tetrahydrofuran and 31.7ml of 3-methyl-l-butanol were used; for production of the solid components in Step (ii) 20ml of TiCl4 was used; otherwise the process was the same as in Example 1. The results thereof are given in Table I.

[Example 6] For production of the magnesium compound solution in Step (i) in Example 1, 100ml of tetrahydrofuran and 68.1 ml of 2-ethyl-l-hexanol were used; for production of the solid components in Step (ii) 20ml of TiCl4 was used; otherwise the process was the same as in Example 1. The results thereof are given in Table I.

[Example 7] For production of the magnesium compound solution in Step (i) in Example 1, 57ml of tetrahydrofuran and 34.4ml of butanol were used; for production of the solid components in Step (ii) 14.4ml of TICS4 and 24ml of SICK4 were used; otherwise the process was the same as in Example 1. The results thereof are given in Table I.

[Example 8] For production of the magnesium compound solution in Step (i) in Example 1, 57ml of tetrahydrofuran and 34.4ml of butanol were used; for production of the solid components in Step (ii) 14.4ml of TiCl4 and 14ml of SiCl4 were used; otherwise the process was the same as in Example 1. The results thereof are given in Table I.

[Example 9] For production of the magnesium compound solution in Step (i) in Example 1, 57ml of tetrahydrofuran and 34.4ml of butanol were used; for production of the solid components in Step (ii) 14.4ml of TICS4 and 7.6ml of SiCl4 were used; otherwise the process was the same as in Example 1. The results thereof are given in Table I.

[Example 10] For production of the magnesium compound solution in Step (i) in Example 1, 57ml of tetrahydrofuran and 34.4ml of butanol were used; for production of t 1, 67.7m1 of tetrahydrofuran and 40.5ml of butanol were used; for production of the solid components in Step (ii) 14ml of TiCl4 and 7.3 ml of SICK4 were used; otherwise the process was the same as in Example 1. The results thereof are given in Table I.

The results of the polymerization are given in Table I below in terms of the bulk density (g/ml), melt index (g/lOmin.), and the molecular weight distribution (Mw/Mn).

[Comparative Example 1] Step (i) Production of magnesium compound solution Into a 1 .0L reactor equipped with a mechanical stirrer, and filled with a nitrogen atmosphere, a mixture of 1 5g of MgCl2 and 150ml of n-dekane was put, and the mixture was stirred at 400 rpm, after which 75ml of 2-ethyl-l-hexanol was added to it. After the temperature was raised to 120 C and the reaction was allowed to continue for two hours, 6ml of diisobutylphthalate was put in and the reaction was allowed to continue for another hour. The homogeneous solution obtained after the reaction was cooled to ambient temperature.

Step (ii) Production of solid components The above-said magnesium compound solution was transferred to a 1.6L reactor kept at 15 C to 27 C. The solution was stirred at 350 rpm, 30ml of TiC 14 was added to it, and the temperature of the reactor was raised to 90 C. At 90 C reaction was allowed to continue for an hour, stirring was stopped, and the solid components thus produced were allowed to settle down. The supernatant was separated and the solid components were washed twice with 75ml of hexane each wash.

Step (iii) Production of catalyst 150ml of heptane and 120ml of TiCl4 were added to the solid components produced above, and the temperature of the reactor was raised to 80 C. While the reactor was at that temperature 5.61 ml of diisophthalate was added to it, then the temperature of the reactor was raised to 100 C, and it was kept heated at 100 C for two hours. Stirring was stopped, the solid components allowed to settle down, the supernatant was separated, and the solid components were washed five times with 100ml of refined hexane each time. The catalyst was dried in a nitrogen atmosphere and stored away.

Polymerization A polymerization process was performed in the same way as in Example 1 and also using the same quantity as in Example 1 (quantity measured on the basis of the atoms of titanium in the solid complex catalyst). The results thereof are given in Table I.

[Comparative Example 2] Step (i) Production of magnesium compound solution Into a 1 .0L reactor equipped with a mechanical stirrer, and filled with a nitrogen atmosphere, 5g of MgCl2 and 400ml of tetrahydrofuran were placed, and this mixture was stirred at 400 rpm until mixed. Its temperature was raised to the boiling point of tetrahydrofuran so as to completely dissolve the MgCI2, and 2ml of diisobutylphthalate was added afterwards for further reaction lasting one hour. The homogeneous solution obtained after the reaction was cooled to ambient temperature.

Step (ii) Production of solid components Into the 1.6L reactor, kept at 15 C - 27 C, the magnesium solution was transferred. The reactor was stirred at 350 rpm, 30ml of TiCl4 was added thereto, and the temperature of the reactor was raised to 90 C. Reaction was allowed to continue at 90 C for one hour, then the stirring was stopped to let the solid components settle down. The supernatant was separated, and the solid components were washed twice with 75ml of hexane each wash.

Step (iii) Production of catalyst After 150mi of heptane and 120ml of TiCl4 were put in, the temperature of the reactor was raised to 80 C. At this temperature 1.87ml of diisophthalate was added, the temperature of the reactor was raised to 100 C, and it was kept heated for two hours. Stirring was stopped, the solid components were allowed to settle down, the suprenatant was separated, the solid components were washed five times with 100ml of refined hexane each wash. The resultant catalyst was dried in a nitrogen atmosphere and stored away.

Polymerization A polymerization was performed with the use of the same quantity as in Example 1 (quantity measured on the basis of the atoms of titanium in the solid complex catalyst), and in the same way as in Example 1. The results of the polymerization are given in Table I.

Table I Polymerization Condltlons Polvmerization Results External Electron Hydrogen Activity Stereoreg Melt Bulk Mw/Mn Donor Amount (kg-pp/g -ularity Index Density (ml) -cat. hr.) (%) (g/lOmin.) (ginil) Exmp./ Kind Amount Comp. (mmol) Exmp.

Exmp.l CMDS 1.00 100 6.2 97.8 10.5 0.41 5.8 Exmp. 2 CMDS 1.00 100 3.3 97.2 9.50 0.37 5.9 Exmp. 3 CMDS 1.00 100 3.5 97.5 11.0 0.39 5.7 Exmp. 4 CMDS 1.00 100 5.4 96.8 8.90 0.34 6.1 Exmp. 5 CMDS 1.00 100 4.5 96.2 10.1 0.36 6.3 Exmp. 6 CMDS 1.00 100 4.2 96.9 8.80 0.38 6.0 Exmp. 7 CMDS 1.00 100 4.7 95.9 9.70 0.37 5.4 Exmp. 8 CMDS 1.00 100 3.6 95.2 10.7 0.39 5.9 Exmp. 9 CMDS 1.00 100 3.7 96.4 9.70 0.40 6.1 Exmp. 10 CMDS 1.00 100 4.8 96.6 11.2 0.38 5.7 Exmp. 11 CMDS 1.00 100 4.1 95.8 10.8 0.36 5.9 Comp.

Exmp. 1 CMDS 1.00 100 3.7 95.2 9.60 0.22 6.2 Comp.

Exmp. 2 CMDS 1.00 100 4.3 93.7 10.5 0.24 5.7 Note) CMDS: Cyclohexylmethyldimethoxysilane

Claims (8)

WHAT IS CLAIMED IS:

1. An improved process for polymerization or copolymerization of olefins, wherein the improvement consists of use of a catalytic system comprising: a) a solid titanium complex catalyst produced by the steps of: 1) preparing a magnesium compound solution by dissolving a magnesium compound in a mixed solvent of cyclic ether and alcohol, 2) precipitating solid components by reacting said magnesium compound solution with a transition metal compound, and 3) reacting said solid components with a transition metal compound and an internal electron donor, b) an organometallic compound and, c) an organosilicon compound as external electron donor.

2. A process according to Claim 1, wherein said magnesium compound in said step 1) is selected from the group consisting of alkylmagnesium halide, alkoxymagnesium halide, aryloxymagnesium halide, alkoxymagnesium, aryloxymagnesium, magnesium carboxylates and mixtures thereof.

3. A process according to Claim 1, wherein in said step 2), said transition metal compound is titanium tetrachloride or silicon tetrachloride; and said transition metal compound in said step 3) is titanium tetrachloride.

4. A process according to Claim 1, wherein in said step 1), said mixed solvent of cyclic ether and alcohol is used in an amount of at least 0.5mol per Imol of said magnesium compound.

5. A process according to Claim 1, wherein in said step 1), said cyclic ether is used in a molar ratio of from 1:0.05 to 1:0.95 of said alcohol.

6. A process according to Claim 1, wherein in said step 3), said internal electron donor is an aromatic ester.

7. A process according to Claim 1, wherein said organometallic compound is an organoaluminum compound.

8. A process according to Claim 1, wherein said organosilicon compound is selected from the group consisting of diphenylmethoxysilane, phenyltrimethoxysilane, phenylethyldimethoxysilane, phenylmethyldimethoxysilane, isobutyltrimethoxysilane, diisobutyldimethoxysilane, diisopropyldimethoxysilane, di-t-butylmethoxysilane, t-butyltrimethoxysilane, cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, and a mixture thereof.