JP2627669B2 - Method for producing polyolefin - Google Patents

Description

The present invention relates to a method for producing a polyolefin. More specifically, the present invention relates to a method for producing a polyolefin which can polymerize an olefin with excellent polymerization activity even when the amount of aluminoxane used is reduced, has a large bulk specific gravity, and is excellent in powder properties.

[Prior art and its problems] As a homogeneous catalyst for olefin polymerization, a so-called Kaminsky catalyst is well known. It is known that this catalyst has a very high polymerization activity and, for example, in propylene polymerization, any of atactic polypropylene, isotactic polypropylene and syndiotactic polypropylene can be produced. (Ma
kromol.Chem.Rapid Commum.4,417-421 (1983), Angew.C
hem.Int.Ed.Engl.24,507-508 (1985), J.Am.Chem.Soc.1
987.109,6544-6545, J.Am.Chem.Soc. 1988.110,6255-625
6) However, the bulk specific gravity of the polymer obtained from these homogeneous catalysts was small, and it was difficult to obtain a polymer having excellent powder properties.

On the other hand, attempts have been made to carry out olefin polymerization using a catalyst in which one or both components of a transition metal compound and an aluminoxane are supported on a particulate carrier. For example, as a method of carrying out polymerization by supporting a catalyst on an inorganic oxide carrier such as silica, silica-alumina, and alumina, JP-A-61-108610, JP-A-61-276805, and
61-296008, JP-A-63-22804, JP-A-63-280703, JP-A
63-51407, JP-A-63-54403, JP-A-63-61010, JP-A-63-6
6206, JP-A-63-89505, JP-A-63-152608, JP-A-63-21
3504 and JP-A-63-248803 have been proposed.

Further, as a method using an Mg compound as a carrier, Japanese Patent Application Laid-Open
-230802, JP-A-63-168408, JP-A-63-168409, JP-A-6
3-175004, JP-A-64-6003, JP-A-64-6004, JP-A-64-6
005, JP-A-64-11104 and JP-A-64-11105 have been proposed. Further, examples of the method using a particulate polymer as a carrier include JP-A-63-92621 and JP-A-63-260903.

However, even when an olefin is polymerized using a solid catalyst component supported on these prior art particulate polymers, the polymerization activity is low, and the powder properties such as the bulk specific gravity of the produced polymer are insufficient. There was a problem that only a good result could be obtained.

The present inventors have conducted studies to solve the above problems, and as a result, by using a transition metal compound [B] as a transition metal compound component and using a particulate polymer as a carrier, the polymerization activity is high, Furthermore, they have found that a polymer having a large bulk specific gravity and excellent powder properties can be obtained, and based on this finding, the present invention has been achieved.

[Means for Solving the Problems] That is, the present invention provides (1) a particulate polymer [A], and [B] a transition metal compound represented by the general formula [I]. (However, M represents a transition metal of titanium, zirconium or hafnium, and Y represents silicon or germanium.)
R ¹ _n ▼ -C ₅ H _4-n and ▲ R ¹ _q ▼ -C ₅ H _4-q represent an unsubstituted or substituted cyclopentadienyl group, and n and q are integers of 0 to 4, At the same time, it does not take a value of 0. Each R ¹ may be the same or different from each other, and represents an element, a silyl group or a hydrocarbon group, but the position and type of R ¹ on the cyclopentadienyl ring are arranged such that no symmetry plane including M exists. Shall be taken. Each R ² may be the same or different and represents a hydrogen or hydrocarbon group. X may be the same or different and represents a hydrogen, a halogen or a hydrocarbon group. In addition, dimethylsilyl (cyclopentadienyl) (methylcyclopentadienyl) zirconium dichloride is excluded. ), [C] aluminoxane, a solid catalyst component in which either [B] or [C] or both [B] and [C] components are supported on [A]. And a method for producing a polyolefin characterized by polymerizing an olefin.

The solid catalyst component [A] used in the method of the present invention is a particulate polymer which is an organic carrier, and specifically, a particulate polyolefin such as polyethylene, polypropylene, poly-1-butene, or a polyester, Examples thereof include polyamide, polyvinyl chloride, polymethyl methacrylate, polymethyl acrylate, polystyrene, and various other natural polymers.

The properties of the carrier vary depending on its type and manufacturing method,
Particles having a particle size in the range of 5 to 2000 μm, preferably 10 to 1500 μm are used.

The molecular weight of these carriers is arbitrary as long as these compounds can exist as solid substances. For example, if you take polypropylene as an example, about 10,000 to 5,000,000
It is possible to use polypropylene having a weight average molecular weight in the range of

Further, these carriers may be preliminarily subjected to a preliminary contact treatment with an organoaluminum compound or a halogen-containing silane compound prior to supporting the transition metal compound or the aluminoxane.

The solid catalyst component [B] used in the method of the present invention is a transition metal compound having a bridged bis-substituted cyclopentadienyl bridge-type bidentate ligand. In the general formula [I], M is a transition metal of titanium, zirconium or hafnium, preferably zirconium. Y is silicon or germanium.
The number of substituents on the two cyclopentadienyl rings may be any from unsubstituted to four-substituted, but at least one of the cyclopentadienyl rings has a substituent.

Each R ¹ may be the same and different, and represents hydrogen, a silyl group or a hydrocarbon group (eg, an alkyl, alkenyl, aryl, alkylaryl, arylalkyl group having 1 to 20 carbon atoms), The position and the type on the cyclopentadienyl ring of ¹ are arranged so that no symmetry plane including M exists.

Examples of the silyl group include a trimethylsilyl group, a triethylsilyl group, and a triphenylsilyl group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a phenyl group, a tolyl group, a biphenyl group, and a naphthyl group. . Each R ² may be the same or different and is hydrogen or the above-mentioned hydrocarbon group. X is hydrogen, halogen such as fluorine, chlorine, bromine or arsenic, or the above-mentioned hydrocarbon group.

Non-limiting examples of the transition metal compound include dimethylsilylbis (methylcyclopentadienyl) silconium dichloride, dimethylsilylbis (t-butylcyclopentadienyl) zirconium dichloride, dimethylsilyl (cyclopentadienyl) ( t-butylcyclopentadienyl) zirconium dichloride, dimethylsilyl (methylcyclopentadienyl) (t-butylcyclopentadienyl) zirconium dichloride, dimethylgermylbis (methylcyclopentadienyl) zirconium dichloride, dimethylsilyl (methyl) Cyclopentadienyl) (2,4-dimethylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (2,3,5 Zirconium compounds such as trimethylcyclopentadienyl) zirconium dichloride and dimethylgermylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (methylcyclopentadienyl) titanium dichloride, dimethylsilylbis (2, Titanium compounds such as 4-dimethylcyclopentadienyl) titanium dichloride and dimethylsilylbis (2,3,5-trimethylcyclopentadienyl) titanium chloride, dimethylsilylbis (methylcyclopentadienyl) hafnium dichloride, dimethylsilylbis Hafnium compounds such as (2,4-dimethylcyclopentadienyl) hafnium dichloride and dimethylsilylbis (2,3,5-trimethylcyclopentadienyl) hafnium dichloride can be exemplified.

The solid catalyst component [C] used in the method of the present invention has the general formula [II] or the general formula [III], Is an organoaluminum compound represented by R ³ is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group, and a butyl group, and is preferably a methyl group or an ethyl group. m is 4 ~
It is an integer of 60, preferably 6 or more. Processes for producing compounds of this type are known. For example, trialkyl is added to a hydrocarbon medium suspension of a compound containing adsorbed water or a salt containing water of crystallization (eg, copper sulfate hydrate, aluminum sulfate hydrate). A method of reacting by adding aluminum can be exemplified.

In the present invention, the following method can be employed as a method for supplying aluminoxane [C] to the polymerization reaction system.

(1) A method in which only a transition metal compound [B] is supported on a particulate polymer [A] as a solid catalyst component, and the solid catalyst component and aluminoxane [C] are supplied to a polymerization reaction system.

(2) A method in which only the aluminoxane [C] is supported on the particulate polymer [A] as the solid catalyst component, and the solid catalyst component and the transition metal compound [B] are supplied to the polymerization reaction system.

(3) A method in which both a transition metal compound [B] and an aluminoxane [C] are supported on a particulate polymer [A] as a solid catalyst component, and the solid catalyst component is supplied to a polymerization reaction system.

(4) The solid catalyst component of the above (2) is used as the solid catalyst component, and the solid catalyst component and the transition metal compound [B] are used.
Together with aluminoxane [C] to the polymerization reaction system.

(5) As the solid catalyst component, the solid catalyst component of (3) above is used, and aluminoxane [C] is used together with the solid catalyst component.
Is supplied to the polymerization reaction system.

In the present invention, the method for supporting the transition metal compound [B] on the particulate polymer [A] includes the following methods (a) to (a).
The method (c) can be adopted.

(A) A method of forming a solid catalyst component by bringing a solution of a transition metal compound into contact with a particulate polymer.

(B) A method of forming a solid catalyst component by contacting a suspension of a particulate polymer dispersed in a solution of a transition metal compound with a medium insoluble or hardly soluble in the transition metal compound. A method of forming a solid catalyst component by distilling off a solvent from a suspension of a particulate polymer dispersed in a solution.

Aluminoxane [C] is added to the particulate polymer [A].
Can be carried out by the following methods (d) and (e).

(D) A method of forming a solid catalyst component by contacting a suspension of a particulate polymer dispersed in a solution of aluminoxane with a medium insoluble or hardly soluble in aluminoxane.

(E) A method of forming a solid catalyst component by removing a solvent from a suspension of a particulate polymer dispersed in a solution of aluminoxane.

In addition, the following methods (f) to (i) can be employed as a method for supporting both the transition metal compound [B] and the aluminoxane [C] on the particulate polymer [A].

(F) A suspension of the particulate polymer dispersed in a solution of aluminoxane is brought into contact with an insoluble or hardly soluble medium of aluminoxane to form an aluminoxane-supported carrier, and then a solution of the carrier and a transition metal compound Or a solvent is distilled off from a suspension of the supported carrier dispersed in a solution of a transition metal compound to form a solid catalyst component.

(G) evaporating the solvent from the suspension of the particulate polymer dispersed in the solution of the aluminoxane to form an aluminoxane-supported carrier, and then contacting the carrier with the solution of the transition metal compound; or A method of forming a solid catalyst component by removing a solvent from a suspension of the supported carrier dispersed in a solution of a transition metal compound.

(H) A transition metal compound-supported carrier is formed by contacting a transition metal compound solution with a particulate polymer, and then the suspension in which the carrier is dispersed in an aluminoxane solution and the insoluble or poorly soluble aluminoxane A method of forming a solid catalyst component by contacting with a solvent or distilling off the solvent from a suspension of the supported carrier dispersed in a solution of aluminoxane.

(I) A transition metal compound-supported carrier is formed by removing the solvent from a suspension of the particulate polymer dispersed in the solution of the transition metal compound, and then the carrier is dispersed in an aluminoxane solution. A solid catalyst component by contacting the suspension with an insoluble or sparingly soluble solvent of aluminoxane, or by distilling the solvent from the suspension of the supported carrier dispersed in a solution of aluminoxane.

As a soluble medium of the transition metal compound [B], for example,
Examples thereof include aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene, and halogen-containing hydrocarbons such as chlorobenzene and dichloroethane.

Examples of the insoluble or hardly soluble solvent of the transition metal compound [B] include pentane, hexane, decane, dodecane,
Examples thereof include aliphatic or alicyclic hydrocarbons such as cyclohexane.

As a soluble solvent of aluminoxane [C], for example,
Examples thereof include aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene.

Examples of the insoluble or poorly soluble solvent for aluminoxane [C] include pentane, hexane, decane, dodecane,
Examples thereof include aliphatic or alicyclic hydrocarbons such as cyclohexane.

The solid catalyst component prepared by the above method is a particulate polymer.
When the transition metal compound [B] is contained per 100 g, the transition metal atom concentration is 0.01 to 500 mmol, preferably 0.05 to 0.05 mmol.
Contains ~ 200 mmol. When the aluminoxane [C] is contained, the aluminum atom concentration is 1 to 1.
It contains 50,000 mmol, preferably 10 to 10,000 mmol.

Further, when the content of both the transition metal compound [B] and the aluminoxane [C] is contained, respectively, the content is within the above range, but the atomic ratio of aluminum to the transition metal (A1 / M) is preferably 1 to 2000, and more preferably 1 to 2000. Ranges from 5 to 1500.

In the method of the present invention, the olefin used in the polymerization reaction is ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-octene.
Α-olefins such as decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene, and a mixture of two or more of these can be used for polymerization.

The above α-olefins, butadiene, 1,4-hexadiene, 1,4-pentadiene, 1,7-octadiene, 1,8
-It is also effective for copolymerization with conjugated and non-conjugated dienes such as nonadiene and 1,9-decadiene, or with styrene or cyclic olefins such as cyclopropane, cyclobutene, cyclohexene, norbornene and dicyclopentadiene. .

The polymerization method used in the method of the present invention can be either liquid phase polymerization or gas phase polymerization. In the liquid phase polymerization, an inert hydrocarbon may be used as a solvent, or a liquefied olefin itself such as liquefied propylene and liquefied butene-1 may be used as a solvent.

As the polymerization solvent, benzene, toluene, ethylbenzene, aromatic hydrocarbons such as xylene, butane, isobutane, pentane, hexane, octane, decane, dodecane, hexadecane, aliphatic hydrocarbons such as octadecane,
Examples thereof include alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, and cyclooctane, and petroleum fractions such as gasoline, kerosene, and light oil.

The concentration of transition metal atoms in the polymerization reaction system in the method of the present invention is not particularly limited, but is preferably in the range of 10 ^-2 to 10 ^-10 mol / l in terms of transition metal atom concentration. The amount of aluminoxane used is not particularly limited, but A1
The molar ratio of the / transition metal atom is 10 or more, preferably 20 or more.

The olefin pressure of the polymerization reaction system is not particularly limited, but is preferably in the range of normal pressure to 50 kg / cm ² G, and the polymerization temperature is not particularly limited, but is usually -50 to 230 ° C., preferably It is in the range of −30 to 100 ° C. The molecular weight at the time of polymerization can be adjusted by known means, for example, by selecting a temperature or introducing hydrogen.

In the method of the present invention, it is preferable to carry out prepolymerization of the olefin in the presence of a solid catalyst component containing a transition metal compound prior to polymerization of the olefin. The pre-polymerization is performed at 0.01 to 100 g, preferably 0.1 to 50 g, per 1 g of the solid catalyst.
This is carried out by polymerizing the olefin. Examples of the olefin used in the prepolymerization include ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene,
-Tetradecene and the like.

[Effects of the Invention] According to the present invention, even if the amount of aluminoxane used is reduced, the polymerization activity does not decrease, the bulk specific gravity is large, and a polyolefin excellent in powder properties can be produced.

[Examples] Next, the present invention will be specifically described with reference to Examples.

Example 1 [Preparation of solid catalyst component] In a 300 ml glass reaction vessel, 10 g of polypropylene powder (manufactured by Chisso Petrochemical Co., Ltd.) and 0.03 mmol of dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride were placed. 30 ml of toluene solution was added. After stirring at room temperature for 30 minutes, nitrogen was flowed for 1 hour to distill off toluene.

This includes methylaluminoxane (molecular weight 990) manufactured by Tosoh Akzo Co., Ltd., equivalent to 15 mmol of A1 atoms.
0 ml of toluene solution was added. After stirring at room temperature for 30 minutes,
A solid catalyst component was prepared by flowing nitrogen for 1 hour and distilling off toluene.

[Preliminary polymerization] To a 300 ml glass reaction vessel were added 50 ml of purified toluene and the entire amount of the solid catalyst component under a nitrogen atmosphere, and then propylene was supplied at room temperature for 4 hours. After supplying propylene, the inside of the system was replaced with nitrogen, and nitrogen was further flown at room temperature for 15 hours to distill off toluene.

Example 2 [Polymerization] 100 g of polypropylene powder (manufactured by Chisso Petrochemical Co., Ltd.) and 5 g of A1 atom corresponding to Tosoh Co., Ltd.
After adding 10 ml of a toluene solution containing methylaluminoxane (molecular weight: 990) manufactured by Akzo Co., Ltd., nitrogen was flowed for 1 hour to distill off toluene.

Then, the entire amount of the pre-polymerized solid catalyst component prepared in Example 1 was added. Total pressure of 10 kg / cm ^{2 with} propylene
G and polymerization was carried out at 50 ° C. for 2 hours. After completion of the polymerization, the total yield of the obtained polymer was 161 g, the catalytic activity was 9.1 kg / gZr · hr, and the apparent bulk specific gravity was 0.45 g / ml.

Example 3 [Preparation of solid catalyst component] In a 300 ml glass reaction vessel, 10 g of polypropylene powder (manufactured by Chisso Petrochemical Co., Ltd.) and 0.04 mmol of dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride were added. 40 ml of a toluene solution was added. After stirring at room temperature for 30 minutes, nitrogen was flowed for 2 hours to distill off toluene.

This includes methylaluminoxane (molecular weight 990) manufactured by Tosoh Akzo Co., Ltd., which corresponds to 10 mmol of A1 atoms.
0 ml of toluene solution was added. After stirring at room temperature for 30 minutes,
A solid catalyst component was prepared by flowing nitrogen for 1 hour and distilling off toluene.

Example 4 [Polymerization] 100 g of polypropylene powder (manufactured by Chisso Petrochemical Co., Ltd.) and 10 g of Tosoh Co., Ltd.
After adding 20 ml of a toluene solution containing methylaluminoxane (molecular weight: 990) manufactured by Akzo Co., Ltd., nitrogen was flowed for 1 hour to distill off toluene.

Next, the entire amount of the solid catalyst component prepared in Example 3 was added. The total pressure was adjusted to 10 kg / cm ² G with propylene, and polymerization was carried out at 50 ° C. for 2 hours. After completion of the polymerization, the total yield of the obtained polymer was 170 g, and the catalytic activity was 8.2 kg / gZ.
r · hr and apparent bulk specific gravity were 0.44 g / ml.

Example 5 [Preparation of solid catalyst component] In a 300 ml glass reaction vessel, 10 g of polypropylene powder (manufactured by Chisso Petrochemical Co., Ltd.) and 0.02 mmol of dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride were added. 20 ml of toluene solution was added. After stirring at room temperature for 30 minutes, the solid catalyst component was prepared by flowing nitrogen for 1 hour and distilling off toluene.

Example 6 [Polymerization] 100 g of polypropylene powder (manufactured by Chisso Petrochemical Co., Ltd.) and 20 g of A1 atom equivalent to 20 mmol of A1 atom were placed in a 1 L SUS gas-phase autoclave sufficiently purged with nitrogen.
After adding 40 ml of a toluene solution containing methylaluminoxane (molecular weight: 990) manufactured by Akzo Co., Ltd., nitrogen was flown for 2 hours to distill off toluene.

Then, the entire amount of the solid catalyst component prepared in Example 5 was added. The total pressure was adjusted to 10 kg / cm ² G with propylene, and polymerization was carried out at 50 ° C. for 2 hours. After the completion of the polymerization, the total yield of the obtained polymer was 145 g, and the catalytic activity was 9.6 kg / gZ.
r · hr and apparent bulk specific gravity were 0.44 g / ml.

Comparative Example 1 100 g of polypropylene powder (manufactured by Chisso Petrochemical Co., Ltd.) and 0.02 mmol of dimethylsilylbis (2,4
-Dimethylcyclopentadienyl) zirconium dichloride in 20 ml of toluene solution and Tosoh Akzo Co., Ltd. methylaluminoxane (molecular weight 990) corresponding to 20 mmol of A1 atoms in 40 ml of toluene solution were added successively. Was flowed for 3 hours, and toluene was distilled off. The total pressure was adjusted to 10 kg / cm ² G with propylene, and polymerization was carried out at 50 ° C. for 2 hours. After completion of the polymerization, the total yield of the obtained polymer was 115 g, the catalytic activity was 4.1 kg / gZr · hr, and the apparent bulk specific gravity was 0.35 g / ml.

[Brief description of the drawings]

1 to 3 are manufacturing process diagrams (flow sheets) for explaining the method of the present invention.

Claims (1)

(57) [Claims] [1] A particulate polymer, [B] a transition metal compound represented by the general formula [I], (However, M represents a transition metal of titanium, zirconium or hafnium, and Y represents silicon or germanium.)
R ¹ _n ▼ -C ₅ H _4-n and ▲ R ¹ _q ▼ -C ₅ H _4-q represent an unsubstituted or substituted cyclopentadienyl group, and n and q are integers of 0 to 4, At the same time, it does not take a value of 0. Each R ¹ may be the same or different from each other, and represents an element, a silyl group or a hydrocarbon group, but the position and type of R ¹ on the cyclopentadienyl ring are arranged such that no symmetry plane including M exists. Shall be taken. Each R ² may be the same or different and represents a hydrogen or hydrocarbon group. X may be the same or different and represents a hydrogen, a halogen or a hydrocarbon group. In addition, dimethylsilyl (cyclopentadienyl) (methylcyclopentadienyl) zirconium dichloride is excluded. ), [C] aluminoxane, a solid catalyst component in which either [B] or [C] or both [B] and [C] components are supported on [A]. And polymerizing the olefin.