JPH02302410A - Production of highly stereoregular polypropylene - Google Patents

Abstract

PURPOSE:To obtain a PP having high stereoregularity in high activity in high yield economically and advantageously by using a catalyst comprising a specific organometallic compound and alumoxane and polymerizing propylene. CONSTITUTION:Propylene is polymerized in the presence of a catalyst comprising (A) an organometallic compound (preferably compound shown by formula II) shown by formula I (R<1> is 1 to 20C hydrocarbon and when two R<1>s exist in adjoining position of cyclopentadienyl ring, two R<1>s may form carbon ring; R<2> is >=3C hydrocarbon, thioaryl and when two R<2>s exist, carbons may be mutually bonded directly or through S; M is Ti, Zr or Hf; X is hydrocarbon or halogen; (n) is 1 to 4; (m) is 0 to 4; (1) is 1 or 2) to give the objective PP.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an improvement in a method for producing highly stereoregular polypropylene. More specifically, the present invention relates to an economically advantageous method for producing polypropylene with high stereoregularity in high yield using a catalyst comprising a combination of a specific transition metal compound and an alumoxane.

Prior Art Conventionally, catalysts consisting of sterically immobilized zirconocenes, such as ethylene bis(indenyl)zirconium dichloride and methylalumoxane, have been used to provide highly active, highly stereoregular polyσ-olefins (especially 1986-
130314), high stereoregularity is generated by changing the transition metal species to hafnium or using a catalyst component containing an indenyl ring in which the ethylene chain bridging two indenyl rings is changed to an alkyl silicon chain. It is known that the molecular weight of polyolefin increases and the melting point increases (Japanese Patent Application Laid-open No. 63-295607).

However, when producing polypropylene with high stereoregularity in high yield using such a sterically fixed metallocene-alumoxane catalyst system, the alumoxane used as a cocatalyst component during polymerization must be used at an extremely high concentration. Therefore, although the catalyst system has a high activity per transition metal component, it results in a significantly low activity per alumoxane. In addition, a particularly preferred alumoxane is methylalumoxane, which is relatively expensive, but it must be used in large quantities, which is economically disadvantageous.

Problems to be Solved by the Invention The present invention overcomes the drawbacks of such conventional methods for producing polypropylene with high stereoregularity, and economically advantageously produces polypropylene with high stereoregularity in high yield. This was done for the purpose of providing a method.

Means for Solving the Problems As a result of intensive research into a method for obtaining polypropylene with high stereoregularity, the present inventors used a certain type of transition metal compound as one of the catalyst components and added alumoxane to it. The combined catalyst system unexpectedly has high activity despite relatively low loadings of alumoxane relative to the transition metal compound, and provides scales that economically advantageously provide highly stereoregular polypropylene in high yields. Based on this finding, we have completed the present invention.

That is, in the present invention, in producing highly stereoregular polypropylene by polymerizing propylene in the presence of a catalyst, (A) general formula (in the formula, R' is carbonized carbon having 1 to 20 carbon atoms) A hydrogen group,
When two R1s are present at adjacent positions on the cyclopentagenyl ring, they may be combined to form a carbocyclic ring, and R2 is a hydrocarbon group or thioaryl group having 3 or more carbon atoms, When two of these exist, the carbon atoms thereof may be bonded to each other directly or via a sulfur atom, M is titanium, zirconium, or hafnium, and X is a hydrocarbon group or a halogen atom. and
n is a number from 1 to 4, m is 0 or a number from 1 to 4, Q is l or 2
The present invention provides a method for producing highly stereoregular polypropylene, which is characterized by using an organometallic compound represented by

The present invention will be explained in detail below.

The catalyst used in the method of the present invention consists of a combination of the above-mentioned (A) component and (B) component, and the (A
) As the component, an organometallic compound represented by the general formula (I) is used.

Each cyclopentadienyl group in the general formula (I) may be substituted with 1 to 4 hydrocarbon groups having 1 to 20 carbon atoms, and specific examples of this hydrocarbon group include methyl group, ethyl group, etc. aliphatic groups such as propyl group, butyl group, isobutyl group, t-butyl group, amyl group, isoamyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, cetyl group, phenyl group, ncrohexyl group,
Mention may be made of alicyclic and aromatic hydrocarbon groups. In addition, when two R1s are present in adjacent positions of each cyclopentagenyl ring, they bond to each other to form a carbocycle, and the cyclopentagenyl ring is combined with a co-niintenyl group, a hydrogenated indenyl group, In the present invention, it is particularly preferable to use a component having such an indenyl group or a hydrogenated indenyl group as the component (A).

Furthermore, the alkylene group bonding two cyclopentadienyl groups has 1 to 4 carbon atoms, and examples of such groups include methylene group, ethylene group, 1.3-
Straight chain or branched alkylene groups such as propylene group, 1.2-propylene group, 1.4-butylene group, and 2.3-butylene group can be mentioned, but among these, ethylene group is particularly preferred. Further, M in the general formula (I) is titanium, zirconium or hafnium,
Among these, zirconium and hafnium are preferred;
Zirconium is particularly suitable.

R2 in the general formula (I) is a hydrocarbon group having 3 or more carbon atoms or a thioaryl group, and when this is a hydrocarbon group, for example, a propyl group, a butyl group, an amyl group,
Examples include isoamyl group, hexyl group, isobutyl group, heptyl group, octyl group, nonyl group, decyl group, cetyl group, phenyl group, and substituted phenyl group. Furthermore, when two R2's exist, the carbon atoms therein may be bonded to each other directly or via a sulfur atom.

In the method of the present invention, it is particularly preferable to use a compound in which two R2 groups are bonded together, and examples of such compounds include compounds represented by the general formula.

-R3-(S), -R3- in the general formula (II)
As an example when r is 0, for example, biphenylene group,
Biferene group, 4,4'-dimethyl-6,6'-di-L
-butyl-2,2'-methylene diphenylene group, and examples where r is l include, for example, 4
．． 4'-dimethyl-6,6'-dimethyl-butyl-2,2
Mention may be made of divalent residues such as '-thiodiphenylene groups.

X in the general formula (I) is a hydrocarbon group or a halogen atom, and specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a t-butyl group, an amyl group, an isoamyl group, hexyl group, heptyl group,
Examples include aliphatic and aromatic hydrocarbon groups such as octyl group, nonyl group, decyl group, cetyl group, and phenyl group, and halogen atoms such as chlorine, bromine, and iodine, and among these, chlorine is particularly preferred.

Specific examples of the compound represented by the general formula (I) include ethylenebis(indenyl)titanium dipropoxide, ethylenebis(indenyl)propoquine titanium chloride, ethylenebis(indenyl)titanium dibutoxide, ethylenebis(indenyl) Butoxytitanium chloride, ethylene bis(tetrahydroindenyl) titanium dipropoquine, ethylene his(tetrahydroindenyl) propoxy/titanium chloride, ethylene bis(tetrahydroindenyl) titanium dibutoquine, ethylene bis(tetrahydroindenyl) butoxytitanium chloride, Ethylenebis(indenyl)
Titanium-1,1'-bi-2-phenolate, ethylenebis(indenyl)titanium-1,1'-bi-2-
Naphthorate, ethylenebis(indenyl)titanium-4,4'-dimethyl-6,6'-di-t-butyl-2
, 2'-methylene diphenolate, ethylenebis(indenyl)titanium-4,4'-dimethyl-6,6'-
Di-t-butyl-2,2'-thiophenolate, ethylenebis(tetrahydroindenyl)titanium-1,1
'-bi-2-phenolate, ethylenebis(tetrahydroindenyl)titanium-1,1'-bi-2-naphtholate, ethylenebis(tetrahydroindenyl)titanium-4,4'-dimethyl-6,6'-di- t-butyl-2,2'-methylene diphenolate, ethylenebis(tetrahydroindenyl)titanium-4,4'-dimethyl-6,6'-di-t-butyl-2,2'-thiophenolate, Ethylene his(indenyl) silconium dipropoxide, ethylene bis(indenyl) propoquine zirconium chloride, ethylene bis(indenyl) zirconium dibutoxide, ethylene bis(indenyl) butquine zirconium chloride, ethylene his(tetrahydroindenyl) silconium dipropoxide ,
Ethylenebis(tetrahydroindenyl)propoxyzirconium chloride, ethylenebis(tetrahydroindenyl)zirconium dibutoxide, ethylenebis(tetrahydroindenyl)butoxyzirconium chloride, ethylenehis(indenyl)zirconium-1,1'
-B-2-phenolate, ethylene bis(indenyl)
Zirconium-1,1'-bi-2-su7trate, ethylenebis(indenyl)zirconium-4,4'-dimethyl-6,6'-di-t-butyl-2,2'-methylenediphenolate, ethylene Bis(indenyl)zirconium-4,4'-dimethyl-6,6'-di-t-butyl-2,2'-thiophenolate, ethylenebis(tetrahydroindenyl)zirconium-1,t'-hy-2
-phenolate, ethylenebis(tetrahydroindenyl)zirconium-1,1'-bi-2-naphtholate,
Ethylenebis(tetrahydroindenyl)zirconium-4,4'-dimethyl-6,6'-di-1-butyl-
2,2'-methylene diphenolate, ethylene bis(tetrahydroindenyl) zirconium-4,4'-dimethyl-6,6'-di-t-butyl-2,2'-thiophenolate, ethylene bis(indenyl) ) hafnium shift oxide, ethylene bis (indenyl) propoxy hafnium chloride, ethylene bis (indenyl) hafnium shift oxide, ethylene his (indenyl) butquine hafnium chloride, ethylene bis (tetrahydroindenyl) hafnium diproboxylate, ethylene (tetrahydroindenyl) ) Propoquine hafnium chloride, ethylenebis(tetrahydroindenyl)hafnium shift oxide, ethylenebis(tetrahydroindenyl)butquine hafnium chloride, ethylene>his(indenyl)hafnium-1,1'-bi-2-phenolate, ethylenebis (indenyl)hafnium-1,1'-bi2
-naphthorate, ethylenebis(indenyl)hafnium-4,4'-dimethyl-6,6'-di-t-butyl-2,2'-methylenediphenolate, ethylenebis(indenyl)hafnium-4,4'-dimethyl-6,6'-di-t-butyl-2,2'-methylenediphenolate,
indenyl) hafnium-4,4'-dimethyl-6,6
'-di-t-butyl-2,2'-thiophenolate, ethylene his(tetrahydroindenyl) hafnium-1
, 1'-bi-2-7-2-root, ethylenebis(tetrahydroindenyl)hafnium-1,1'-bi-2-naphtholate, ethylenebis(tetrahydroindenyl)hafnium-4,4'-dimethyl-6, 6'-di-t-butyl-2,2'-methylene diphenolate, ethylenebis(tetrahydroindenyl)hafnium-4,4'-
Examples include dimethyl-6,6'-di-t-butyl-2,2'-thiophenolate, among which ethylenebis(indenyl)zirconium-1,1'-bi-2-
Naphthlate and ethylenebis(indenyl)zirconium-4,4'-dimethyl-6,6'-di-tert-butyl-2,2'-thiophel-1. are preferred.

The above catalyst component (A) is usually obtained by reacting a sterically fixed metallocene compound having a cibaride ligand with an organic compound having at least one hydroxyl group. The sterically fixed metallocene compound having the cybaride ligand can be prepared by known methods (for example, JP-A-61-130314, JP-A-63-25140).
It can be produced according to the method described and cited in Publication No. 5).

Both reactions can be carried out at a temperature of -20 to 200°C in a polar solvent such as a hydrocarbon solvent, a halogenated hydrocarbon solvent, or tetrahydrofuran. Furthermore, an organic compound having at least one hydroxyl group may be used directly in the reaction, but since hydrogen halide is generated in the reaction system, ammonia, pyridine, alkyl amine, etc. are added to the reaction system for the purpose of capturing hydrogen halide. It is also possible to add, etc. Furthermore, an organic compound having at least one hydroxyl group can be reacted with an alkali metal such as sodium metal or an alkyl lithium to form a metal alcoholade, metal phenolate, etc., which can then be subjected to this reaction. Here, by controlling the molar ratio during the reaction in both reactions, (ORυ
A catalyst component (A) having a group can be obtained. In addition,
In the reaction with an organic compound having two hydroxyl groups, it is thought that a compound is produced in which the two hydroxyl groups of the organic compound are bonded to the same transition metal.

As the catalyst for the method of the present invention, alumoxane is used as component (B). This alumoxane has the general formula % ([[) (R in the formula is a hydrocarbon group having 1 to 4 carbon atoms, p is 1 to 40
Examples include organoaluminum compounds represented by the following formula.

R in the general formulas (I[[) and (mV)] includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a 5ee-butyl group,
Examples include lower alkyl groups such as t-butyl group,
Among these, methyl group is particularly preferred, and p is preferably 5 or more.

Such alumoxane is generally obtained by reacting trialkylaluminum and water, but there are no particular restrictions on the method for producing it, and any known method can be used. For example, a method in which trialkyl aluminum t-S is dissolved in a hydrocarbon solvent and this solution is brought into contact with water in an amount equivalent to the trialkyl aluminum, or copper sulfate hydrate or aluminum sulfate hydrate is dissolved in a hydrocarbon solvent. After suspending, this suspension and trialkylaluminium are brought into contact with each other at a ratio such that the crystallization water of the hydrate is 1 to 3 times the amount of trialkylaluminium, and the crystallization water is added to the trialkylaluminium. Alumoxane can be produced by a method such as mild hydrolysis of trialkylaluminium.

In the method of the present invention, the component (A) is contained in a proportion such that the concentration of the transition metal atoms is usually in the range of 10-'' to 10-' mol/Q, preferably 10-7 to IO-1 mol/Q. On the other hand, the component (B) has an aluminum atom/transition metal atomic ratio in the range of usually 1-10', preferably 1-10', relative to the component (A). Furthermore, in the present invention, the aluminum atom/transition metal atomic ratio is 1-1.
Even when the activity is as low as 0.00, polymerization can be carried out with sufficiently high activity.

The polymerization method of the present invention is not particularly limited, and methods such as slurry polymerization, solution polymerization, and gas phase polymerization can be used, for example. Moreover, there is no particular restriction on the polymerization method, and the polymerization may be performed in a batch manner or in a continuous manner.

The polymerization method of the present invention is usually carried out using a solvent, such as n-pentane, n-hexane,
Aliphatic hydrocarbons such as isobutane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, benzene,
Aromatic hydrocarbons such as toluene are used. These solvents may be used alone or in combination of two or more.

Furthermore, the polymerization temperature is usually -80 to 10,000. Preferably, the temperature is selected within the range of -20 to 80°C.

The polypropylene thus obtained has a meso-meso sequence fraction of 90% in all triat chains.
It has high stereoregularity.

Effects of the Invention When propylene is polymerized by the method of the present invention, polypropylene with high activity and stereoregularity can be obtained even if a smaller amount of alumoxane is used than in conventional methods.

Examples Next, the present invention will be explained in more detail with reference to examples.
The present invention is not limited in any way by these examples.

In addition, the stereoregularity of the produced polymer is determined by C-NMR
meso-m in all triat chains obtained in the analysis
Shown as a fraction of eso sequences. +3C-NMR analysis is
The polymer was dissolved in 0-dichlorobenzene at a temperature of 135
The test was carried out at °C using JEOL GX-2700.

In addition, the polymerization activity shown in the table is the amount of polymer produced (g)/
This is a value calculated using fk (mmol) of the alumoxane used.

Example 1 (1) (A) Production of catalyst component metallocene 0.8 g of metallic sodium was placed in a flask with an internal volume of 30011112 and equipped with a stirrer and a reflux condenser, and 1,1' dissolved in toluene 100+IIQ at room temperature was added. -Be 2-Add 2.4 mmol of naphthol and stir at 80℃
A time reaction was performed. The bed reaction metal sodium was then removed and this solution was added with 2.4 m of ethylene bis(indenyl)zirconium dichloride dissolved in 150 IlIQ of toluene.
mol was added, and the reaction was further continued for 4 hours.

The solvent was distilled off from the reaction solution, and 150 m (2
was added and allowed to stand, the supernatant liquid was removed, the precipitate was collected, washed with n-hexane, and dried. No CQ was detected from the yellowish-white solid obtained, and it was confirmed by 'H-NMR that it was the target compound, and dissolved in toluene to give 2 mmol/
It was used as an i2 solution.

Alumoxane was produced in accordance with Example 1 of JP-A-58-19309 under a nitrogen stream as follows.

Toluene 250+nm to CuSO4+ 51(2o 3
7.5g (0.15mol.

After suspending H2O (equivalent to 0.75 mol), 50 mQ (0.52 mol) of trimethylaluminum was added, and the mixture was reacted at 20°C for 24 hours with stirring. Evolution of methane gas was observed during the reaction.

After the reaction, copper sulfate was filtered off and toluene was removed from the filtrate, yielding 13.09% of methylalumoxane (44% of the theoretical value). Molecule 1 of this product had an average degree of oligomerization of 640 and an average degree of oligomerization of 11 as determined by the freezing point depression method in benzene.

(3) Polymerization of propylene After introducing 400 mQ of liquid propylene at room temperature into a 1 and 5 Q autoclave that had been thoroughly purged with nitrogen and dried under vacuum, 50 mQ of liquid propylene was introduced at room temperature.
Do not raise the temperature to °C. Continuing, Q in terms of aluminum atoms,
Alumoxane equivalent to 4 mmol and ethylenebis(indenyl)zirconium-1,1 produced in the above (1) equivalent to 0.04 mmol in terms of zirconium atoms.
'-B2-S7 tray was charged and polymerization was carried out for 1 hour. After polymerization, propylene from the bed reaction was removed, hydrochloric acid-methanol was added, the polymer was filtered and dried. The polypropylene thus obtained had a molecular weight of 1209 and a polymerization activity of 300 g polymer/mmol AQ. Also, the rRm fraction of this polymer according to +3C-NMR analysis is 9.
It was 4.0%.

Example 2 In the production of metallocene as the catalyst component (A) in (1) of Example 1, 2,2'-dihydroxy-3,3'-di-t- was used instead of 1,1'-bi-2-naphthol. The entire procedure was carried out in the same manner as in Example 1, except that butyl-5,5'-dimethyldiphenyl sulfide was used.

The results are shown in the table. Example 3 200 mQ of toluene and 200 m of e-propylene were added to a 1,5Q O-1 crepe that had been thoroughly purged with nitrogen and dried under vacuum.
After introducing Q at room temperature, do not raise the temperature to 50°C. Subsequently, Q, alumoxane corresponding to 4 mmol in terms of aluminum atoms, and ethylenebis(indenyl)zirconium-1,1'-bi-2-naphthlate produced in Example 1 (1) corresponding to 0.04 mmol in terms of zirconium atoms were charged. and polymerization was carried out for 1 hour. The polymerization results are shown in the table.

Comparative Example 1 Polymerization was carried out using the same polarity as in Example 1, except that ethylene his(indenyl) zirconium dichloride was used as the metallocene catalyst component. The polymerization results are shown in the table.

Comparative Example 2 The same procedure as in Example 1 was carried out, except that in Example 1, 0.004 mmol of ethylene bis(indenyl)zirconium dichloride was used as the metallocene catalyst component in terms of zirconium atoms, and 4 mmol of methylalumoxane was used in terms of aluminum atoms. Polymerization was carried out. The polymerization results are shown in the table.

Comparative Example 3 Polymerization was carried out in the same manner as in Example 3, except that ethylenebis(indenyl)zirconium dichloride was used as the metallocene catalyst component. The polymerization results are shown in the table.

Claims (1)

[Claims] 1 In producing highly stereoregular polypropylene by polymerizing propylene in the presence of a catalyst, (A) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula R^1 is a hydrocarbon group having 1 to 20 carbon atoms, and when two R^1's are present at adjacent positions of the cyclopentadienyl ring, they combine to form a carbocycle. Also, R^2 is a hydrocarbon group or thioaryl group having 3 or more carbon atoms, and when two of these exist, the carbon atoms thereof are bonded to each other directly or through a sulfur atom. M is titanium, zirconium or hafnium, X is a hydrocarbon group or a halogen atom, n is a number from 1 to 4, m is a number from 0 or 1 to 4, and l is 1
A method for producing highly stereoregular polypropylene, the method comprising using an organometallic compound represented by (or a number of 2) and a catalyst comprising (B) alumoxane. 2 Component (A) has a general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (R^1 in the formula is a hydrocarbon group having 1 to 20 carbon atoms, and two R^1 are cyclopentadi When present in adjacent positions of the enyl ring, they may be combined to form a carbocycle, R^3 is a divalent hydrocarbon group having 3 or more carbon atoms, M is titanium, zirconium or hafnium, n is a number from 1 to 4, m is 0 or a number from 1 to 4, and r is a number from 0 to 1.