JP2895199B2 - Olefin polymerization catalyst - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an olefin polymerization catalyst suitable for a bulk polymerization method and a gas phase polymerization method, and more specifically, a novel olefin polymerization catalyst for polymerizing an olefin at a high yield per catalyst. The present invention relates to a solid polymerization catalyst.

(Prior art)

2. Description of the Related Art There is known a method for polymerizing an olefin using a metallocene compound having a group having a conjugated π electron, particularly cyclopentadiene or a derivative thereof as a ligand, a trialkylaluminum, and methylaluminoxane obtained by a reaction with water as a catalyst. For example, JP-A-58-19303 discloses a method for polymerizing olefins using biscyclopentadienyl zirconium dichloride and methylaluminoxane as catalysts.

On the other hand, it has been reported that a cationic metallocene compound having cyclopentadiene or a derivative thereof as a ligand polymerizes an olefin without using methylaluminoxane. For example, RFJORDAN et al. J. Am. Chem.
Soc., 1986, 108: 7410, reports that a zirconium cation complex having tetraphenylborane as an anion and biscyclopentadienyl group and methyl group as ligands has ethylene polymerization activity. . Also, Tu
Rner et al., J. Am. Chem. Soc., 1989, 111: 2728 reported that an ion-pair zirconium complex also has ethylene polymerization activity. The polymerization of this catalyst system is described in Publications 1-501950 and 1-502036.

Further, Zambelli et al., Macromolecules, 1989, 22: 2186.
On page −2189, it is reported that isotactic polypropylene is polymerized by a combination of a zirconium compound having a derivative of cyclopentadiene as a ligand and trimethylaluminum and fluorodimethylaluminum.

[Problems to be solved by the invention]

The method according to the above-mentioned JP-A-58-19303 and the like is a method having a large activity per transition metal and excellent, but it requires the use of a large amount of expensive aluminoxane, so that not only the cost is high, but also after polymerization. There is a problem that it is difficult to remove the aluminoxane from the produced polymer.

On the other hand, the methods of FRJORDAN et al. And TURNER et al. Do not have the above-mentioned problem because the cationic zirconium complex polymerizes ethylene without using aluminoxane, but these catalysts have a very low polymerization activity, and propylene is polymerized. Otherwise, only those with low stereoregularity can be obtained.
Further, the method of Zambelli et al. Is a method of obtaining isotactic polypropylene using trimethylaluminum, dimethylaluminum fluoride and zirconium complex as a polymerization catalyst of propylene, but this catalyst also has a problem that polymerization activity is very small, There is a problem that the polymerization procedure is complicated because three types of catalyst components are used. In addition, since all of these catalyst systems are homogeneous, the resulting polymer particles become fine and fine powder, which is difficult to handle, has a low bulk density, and lowers productivity.
In addition, there is a problem that the polymer is adhered to all surfaces in the polymerization vessel, which makes it impossible to control the polymerization due to poor heat transfer and causes interruption of continuous polymerization, which makes it difficult to stably perform industrial production. Was.

For the purpose of solving these problems, various studies have been made on supporting a catalyst system of a transition metal metallocene compound and methylaluminoxane on a carrier. For example, JP-A-61-1086
10, JP-A-61-276805, JP-A-61-296008, JP-A-63-296805
In 199206, the solid catalyst in which the reaction product of a transition metal metallocene compound and methylaluminoxane is supported on an inorganic metal oxide such as silica reduces the amount of aluminoxane to transition metal by 1/10 or less compared to a homogeneous catalyst. However, since the polymerization activity per solid catalyst decreases, the amount of aluminoxane contained in the produced polymer cannot be reduced so much, and the problem of removing aluminoxane from the produced polymer after polymerization cannot be solved. . On the other hand, the above-mentioned ion-pair type metallocene compound has a low activity from the beginning and is easily affected by impurities, and the activity is lost due to impurities in a fine particle amount. It was very difficult to synthesize a supported catalyst.

[Means for solving the problem]

The present inventors have diligently studied a method for producing a polyolefin with high productivity with high productivity by solving the above problems, and completed the present invention.

That is, the present invention provides: a) a general formula: (Wherein A and B are the same or different aromatic hydrocarbons, R is a hydrocarbon residue having 1 to 20 carbon atoms connecting A and B, or a compound containing silicon, germanium or tin, X
Is a hydrocarbon residue having 1 to 20 carbon atoms, and M is a metal atom selected from zirconium, titanium and hafnium. B) a compound that reacts with the transition metal compound a) to form an ionic compound; c) supported on a particulate carrier; d) a compound of the general formula AlR _n X _{3 -n} (R is a hydrocarbon group, X is a halogen or alkoxy group, n is 1 to 3) and is an olefin polymerization catalyst obtained by treatment with an organoaluminum compound.

The present invention will be described with reference to a method for producing an olefin polymerization catalyst and a polymerization method using the catalyst.

In the present invention, examples of the transition metal compound having a group having a conjugated π electron represented by the following general formula as a ligand include the compounds described in the above literatures. Any transition metal compound having a group having the general formula: (Where A and B are the same or different aromatic hydrocarbons, R is a hydrocarbon residue having 1 to 20 carbon atoms connecting A and B,
Alternatively, a compound containing silicon, germanium, and tin, X is a hydrocarbon group having 1 to 20 carbon atoms, and M is a metal atom selected from zirconium, titanium, and hafnium. The transition metal compound represented by ()) can be preferably used.

In the general formula, A and B are monocyclic rings having 5 to 30 carbon atoms,
Alternatively, a polycyclic aromatic compound can be exemplified. Specifically, cyclopentadienyl or a compound obtained by substituting a part or all of hydrogen with an alkyl group having 1 to 10 carbon atoms (here, the terminal of the alkyl group is again It may have a structure bonded to a cyclopentadiene ring.), A polycyclic aromatic compound such as indenyl or fluorenyl, or a compound in which part or all of hydrogen atoms are substituted with an alkyl group having 1 to 10 carbon atoms. You.

As R, a dialkyl methylene group, dialkylsilylene group, dialkyl tin based, dialkyl gel Mi alkylene group preferably include, for _{example, R '2 C, R'} 2 Si, R '2 Ge, R' 2 Sn
(Wherein R 'is hydrogen or an alkyl residue having 1 to 20 carbon atoms, which may be the same or different), and a compound represented by the formula: -CR'-CR'- A group can also be exemplified (wherein R 'is the same as described above).

Examples of X include an alkyl group such as methyl, ethyl, propyl and butyl, and an aromatic compound such as cyclopentadienyl group.

In the present invention, examples of the compound that reacts with the transition metal compound to form an ionic compound include an ionic compound formed from an ion pair of a cation and an anion, and an electrophilic compound. These compounds are generally known as Lewis acid compounds, have appropriate Lewis acidity, and have the property of reacting with a neutral metallocene compound used as a catalyst to convert them into ionic compounds. If necessary, it reacts with the transition metal compound represented by the above general formula, whereby the group represented by X is transferred to the Lewis acid compound as an electron pair to form a transition metal cation compound. It does not recombine with the transition metal cation compound formed by itself or the anion that has become an ion pair, or does not inactivate the polymerization activity due to strong coordination. Examples of the cation of the ionic compound include a carbonium cation, a tropylium cation, an oxonium cation, a sulfonium cation, a phosphonium cation, and an ammonium cation.

Examples of the anion of the ionic compound include an organic boron compound anion, an organic aluminum compound anion, an organic phosphorus compound anion, an organic arsenic compound anion, an organic antimony compound anion, and the like. Examples include metal oxides known as solid acids.

The use ratio of the compound that reacts with the transition metal compound to form an ionic compound with respect to the transition metal compound is 0.1 to 10,000 mol times, usually 0.5 to 5000 mol times.

Before carrying the transition metal compound and the compound which reacts with the transition metal compound to form an ionic compound on the carrier compound, the carrier compound may be treated with an organometallic compound in advance if necessary. Examples of the organometallic compound used herein include the first, second and first periodic table.
It is an organometallic compound of a metal belonging to Groups 2, 13, and 14, and among them, a compound of a metal selected from aluminum, zinc, and magnesium is preferably used. These organometallic compounds have residues such as halogen, oxygen, hydrogen, alkyl, alkoxy and aryl as ligands, and these ligands may be the same or different, respectively.
At least one has an alkyl group. For example, carbon number ~
An alkyl metal compound in which 1 to n 12 alkyl residues are bonded, an alkyl metal halide, an alkyl metal alkoxide and the like can be used. For example, as the alkylaluminum compound, trimethylaluminum, triethylaluminum, triisopropylaluminum, tributylaluminum, dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisopropylaluminum isopropoxide, ethylaluminum dichloride, ethylaluminum diisopropoxide, etc. No. Examples of the alkyl zinc compound include diethyl zinc, divinyl zinc and the like. Examples of the alkyl magnesium compound include alkyl magnesium halides such as methyl magnesium chloride, methyl magnesium bromide, ethyl magnesium chloride, propyl magnesium chloride, and butyl magnesium chloride, and dialkyl magnesium such as dimethyl magnesium, diethyl magnesium, and butyl ethyl magnesium. No.

The carrier compound used in the present invention may be any of an organic compound, an inorganic compound, and a solid, as long as it is a fine particle polymer compound, an inorganic oxide, an inorganic halide, an inorganic hydroxide, or a carbonate. And various metal salts such as perchlorate, and a complex thereof.

The carrier compound used in the present invention is preferably an anhydride. Therefore, it is necessary to previously dry the carrier compound before treating the carrier compound with the organometallic compound, except for those obtained industrially as an anhydride. The drying method is usually
100 ° C ~ 1000 in vacuum or under dry inert gas
C., preferably 200 to 800 ° C. for a predetermined time. The size of these carrier compounds is usually from 1 μm to
Those having a thickness of about 0.1 mm can be preferably used.

In addition, there is no particular limitation on the method of contacting a compound that forms an ionic compound by reacting with a transition metal compound with a carrier compound to form a solid catalyst component, and is the same as the above-described method of treating the carrier compound with an organometallic compound. In a liquid phase or a solid phase. That is, the method of contacting these in a solvent involves suspending the carrier compound in an inert solvent such as a hydrocarbon compound and adding a solution of a compound that reacts with the transition metal compound to form an ionic compound. Stirring method and the like can be mentioned.

In addition, as a method of bringing into contact with a solid phase, a method of similarly pulverizing may be mentioned.

The present invention is characterized in that a solid catalyst component carrying a transition metal compound and a compound that reacts with the transition metal compound to form an ionic compound is further treated with an organometallic compound. In this case, the method of treating the carrier compound with the organometallic compound is not particularly limited, and both components may be brought into contact in a solvent or in a solid phase. As a method of bringing them into contact with each other in a solvent, there is a method in which a carrier compound is suspended in an inert solvent such as a hydrocarbon compound, and an organic metal compound is added and stirred. As the solvent used in the treatment, for example, propane, pentane, hexane, heptane, octane, nonane, decane, cyclopentane, benzene in addition to saturated hydrocarbon compounds such as cyclohexane,
Aromatic hydrocarbon compounds such as toluene and xylene, and ether compounds or ester compounds such as diethyl ether and tetrahydrofuran can also be used. In addition, as a method of contacting with a solid phase, a method of co-milling may be mentioned. There is no particular limitation on the method of co-milling, and a commonly used method using a ball mill, vibration mill, or the like can be employed as it is. In addition, various compounds can be used together as a grinding aid as long as the catalyst component is not decomposed under the co-grinding conditions. The organic metal compound used herein has the general formula AlR _n X _3-n (the R hydrocarbon group, X is a halogen or alkoxy group, n represents 1 to 3) is an organoaluminum compound represented by the. Specifically, trimethylaluminum, triethylaluminum, triisopropylaluminum,
Examples include tributylaluminum, dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisopropylaluminum isopropoxide, ethylaluminum dichloride, ethylaluminum diisopropoxide and the like.

The use ratio of the organometallic compound to the transition metal compound is 1 to 10,000 mole times, usually 10 to 50 mole times.

In the present invention, the olefins include ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1, tridecene-1, and the like. In addition to linear α-olefins such as tetradecene-1, pentadecene-1, hexadecene-1, and octadecene-1, branched α such as 3-methylbutene-1, 4-methylpentene-1, and 4,4-dimethylpentene-1 Olefins are exemplified;
These α-olefins can be used not only alone but also in a mixture with each other.

There is no particular limitation on the polymerization conditions in the present invention,
The solid catalyst synthesized in this manner can be used alone as an olefin assembly catalyst, so that the polymerization operation can be greatly simplified, so that a solvent polymerization method using an inert medium,
Alternatively, it can be used for a bulk polymerization method and a gas phase polymerization method in which substantially no inert medium is present. In particular, when used in a bulk polymerization method or a gas phase polymerization method, polymer particles having a large bulk specific gravity are preferably obtained.

In general, the polymerization is carried out at a temperature of -100 to 200 ° C. and at a pressure of normal pressure to 100 kg / cm ² . Preferably -1
0 to 100 ° C, normal pressure to 50 kg / cm ² .

〔Example〕

 Hereinafter, the present invention will be described with reference to Examples.

Example 1 10 g of anhydrous magnesium chloride and triethylaluminum
1.9 ml of a toluene solution containing 0.38 g was mixed, put in a vibration mill (1000 ml of inner volume of a pot, and 2 kg of SUS balls having a diameter of 12.7 mm) and ground together for 17 hours. Further, 2.2 g of triphenylmethanetetrakis (pentafluorophenyl) boron and isopropylcyclopentadienyl-1-fluorene synthesized according to a conventional method as a transition metal catalyst component are lithiated and reacted with zirconium tetrachloride. Propylene (cyclopentadienyl-1-fluorenyl)
0.95 g of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dimethyl obtained by dimethylating zirconium dichloride with methyllithium was put in a vibration mill and ground for 4 hours.

200 mg of the co-ground product was suspended in 100 ml of hexane,
0.46 g of triethylaluminum was added, and the mixture was stirred at room temperature for 17 hours. The supernatant was removed and further washed with 100 ml of hexane.

100 mg of the solid catalyst synthesized in this way was
Put 1.5 kg of propylene in an autoclave at 50 ℃
For 2 hours. Unreacted propylene was purged and the polymer was removed and dried to give 311 g of polymer (equivalent to 1559 g polypropylene / g solid catalyst per hour of polymerization). According to ¹³ C-NMR, the syndiotactic pentad fraction was 0.80, and the intrinsic viscosity (hereinafter referred to as η) measured with a tetralin solution at 135 ° C. was 0.75, 1,2,4.
-The ratio of the weight average molecular weight to the number average molecular weight (hereinafter referred to as MW / MN) measured by gel permeation chromatography using trichlorobenzene as a solvent was 2.3. The bulk specific gravity was 0.36 g / ml, and the amount of the polymer adhered to the wall of the polymerization machine was small.

Example 2 A solid catalyst was synthesized in the same manner as in Example 1 except that 2.4 g of tris (pentafluorophenyl) boron was used instead of triphenylmethanetetrakis (pentafluorophenyl) boron.

When propylene was polymerized using 100 mg of the solid catalyst, 36.2 g of a polymer was obtained. Η of polymer
Was 0.79, the syndiotactic pentad fraction was 0.78, and the MW / MN was 2.2. In addition, the bulk specific gravity was 0.28 g / ml, and the adhesion of the polymer to the polymerization machine was small.

Example 3 Ethylenebis (tetrahydroindenyl) zirconium dichloride obtained by lithiating ethylenebistetrahydroindenyl synthesized according to a conventional method as a transition metal catalyst component and reacting with zirconium tetrachloride was obtained by dimethylation with methyllithium. 0.95 g of ethylenebis (tetrahydroindenyl) zirconium dimethyl
Was used in place of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dimethyl to synthesize a solid catalyst in the same manner as in Example 1. This solid catalyst
When propylene was polymerized using 50 mg, 198 g of a polymer was obtained. The η of the polymer was 1.09, the isotactic pentad fraction was 0.90, and the MW / MN was 2.6. The bulk specific gravity was 0.34 g / ml, and the amount of the polymer adhered to the wall of the polymerization machine was small.

Example 4 Propylene was polymerized in the same manner as in Example 1 except that trioctyl aluminum was used instead of triethyl aluminum, to obtain 300 g of a polymer. The η of the polymer is 0.82 and the syndiotactic pentad fraction is
It was 0.80. MW / MN was 2.4. The bulk specific gravity is 0.35
g / ml, and the adhesion of the polymer to the wall of the polymerization machine was small.

〔The invention's effect〕

By carrying out the process of the present invention, a polyolefin having a high bulk specific gravity and a high activity per catalyst can be obtained, which is extremely valuable industrially.

[Brief description of the drawings]

FIG. 1 is a flowchart for helping the understanding of the present invention.

Continuation of front page (56) References JP-A-3-234709 (JP, A) JP-A-3-203914 (JP, A) JP-A-3-179005 (JP, A) JP-A-3-207704 (JP) , A) Special Table Hei 5-505838 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C08F 4/60-4/70

Claims (1)

(57) [Claims] 1. A) General formula: (Wherein A and B are the same or different aromatic hydrocarbons, R is a hydrocarbon residue having 1 to 20 carbon atoms connecting A and B, or a compound containing silicon, germanium or tin, X
Is a hydrocarbon residue having 1 to 20 carbon atoms, and M is a metal atom selected from zirconium, titanium and hafnium. B) a compound that reacts with the transition metal compound a) to form an ionic compound; c) supported on a particulate carrier; d) a compound of the general formula AlR _n X _{3 An} olefin polymerization catalyst obtained by treating with an organoaluminum compound represented by _-n (R is a hydrocarbon group, X is a halogen or alkoxy group, and n is 1 to 3).