JPH0680683A - New transition metal compound and production of polyolefin using the same - Google Patents

Abstract

PURPOSE:To provide a new compound capable of efficiently producing polyolefins. CONSTITUTION:The objective compound of formula CpA<1>A<2>A<3>nM (Cp is cyclopentadienyl, indenyl, etc.; A<1>-A<3> are each halogen, amide, etc., at least one of them being amide; n is 1-3; M is group IV-VI transition metal), e.g. (cyclopentadienyl) (bistrimethylsilylamido)titanium dichloride. The compound of the formula can be obtained by reaction of a monocyclopentadienyl transition metal compound such as cyclopentadienyl titanium trichloride with a metallic amide compound such as lithium bis(trimethylsilyl)amide e.g. in diethyl ether at room temperature.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel transition metal compound and a method for producing a polyolefin using the same. Specifically, it relates to a novel metallocene compound and a method for producing a polyolefin using the same.

[0002]

2. Description of the Related Art Generally, as an olefin polymerization catalyst, a catalyst system comprising a solid titanium compound containing titanium trichloride as a main component and an organoaluminum compound, a catalyst system comprising a solid catalyst comprising titanium tetrachloride and magnesium chloride and an organoaluminum compound, etc. The so-called Ziegler-Natta type catalyst is known. On the other hand, a transition metal compound having a cyclopentadienyl group, an indenyl group, a fluorenyl group, or a derivative thereof as a ligand, a so-called metallocene compound is used as a polyolefin by polymerizing an olefin using a cocatalyst such as an aluminoxane. It is known that it can be manufactured. JP-A-58-19309 and JP-A-60-35008 describe a method of polymerizing or copolymerizing an olefin in the presence of a catalyst composed of a metallocene compound and an aluminoxane.

JP-A-61-130314 and JP-A-64-66124 disclose poly-α- with high isotacticity by using a catalyst composed of a metallocene compound having a crosslinkable ligand and an aluminoxane. It is stated that olefins can be produced. JP-A-2-
No. 41303, JP-A-2-274703, and JP-A-2-274704 disclose syndiotactic compounds by using a catalyst composed of a metallocene compound having a crosslinkable ligand composed of asymmetrical ligands and an aluminoxane. It is described that tic poly-α-olefins can be produced. Japanese Patent Application Laid-Open No. 3-163088 discloses polymerization of an olefin by using a metallocene compound having a special constrained geometry (bridge structure).
It is disclosed that it is possible to copolymerize or copolymerize ethylene with styrene.

On the other hand, the active species of the so-called Kaminsky type catalyst as described above is [Cp ' ₂ MR] ⁺ (where Cp' = cyclopentadienyl derivative, M = Ti, Zr, Hf, R
= Alkyl), some catalyst systems that do not use aluminoxanes as co-catalysts have been reported since they were suggested to be transition metal cations. Taube et al.
Organometall. Chem., 347 , C9 (1988) [Cp ₂ T
Ethylene polymerization has been successful using a compound represented by iMe (THF)] ⁺ [BPh ₄ ] ^- (Me = methyl group, Ph = phenyl group). Jordan et al., J. Am. Chem. S.
oc., 109 , 4111 (1987), [Cp ₂ ZrR (L)] ⁺
It is shown that zirconium complexes such as (R = methyl group, benzyl group, L = Lewis base) polymerize ethylene. Japanese Patent Publication No. 1-501950, Japanese Patent Publication No. 1-50
No. 2036 describes a method of polymerizing an olefin using a catalyst composed of a cyclopentadienyl metal compound and an ionic compound capable of stabilizing a cyclopentadienyl metal cation. Zambelli et al. Reported in Macromolecules, 22 , 2186 (1989) that isotactic polypropylene can be produced using a catalyst that combines a trimethylaluminum and fluorodimethylaluminum with a zirconium compound having a cyclopentadiene derivative as a ligand. is doing. JP-A-3-179005 discloses an olefin polymerization catalyst comprising a) a neutral metallocene compound, b) aluminum alkyl, and c) Lewis acid. As described above, the so-called Kaminsky-type catalyst having a metallocene compound as a catalyst component may produce a polyolefin having various physical properties because the structure of the polymer produced, the copolymerization performance and the like differ depending on the type of metallocene compound used. It is possible. Therefore, further development of metallocene compounds is expected.

[0005]

An object of the present invention is to develop a novel metallocene component having olefin polymerization performance. In addition, for example, Japanese Patent Laid-Open No. 3-1630
In order to synthesize a metallocene compound having a special constrained geometrical shape as described in Japanese Patent Publication No. 88, an advanced synthetic technique was required.

[0006]

In view of the above problems, the inventors of the present invention have earnestly studied a metallocene compound having an olefin polymerization ability that can be easily synthesized, and as a result, found that a metallocene compound having a specific ligand is efficiently produced. They have found that the polymerization of olefins proceeds, and have completed the present invention. That is, the present invention has the general formula CpA ¹ A ² A ³ _n M (where Cp represents a cyclopentadienyl group, an indenyl group, a fluorenyl group or a derivative thereof.
A ¹ , A ² and A ³ are halogen atom, hydrogen atom, carbon number 1
Alkyl groups up to -10, alkoxy groups, C6-2
It is an aryl group up to 0, an alkylaryl group, an arylalkyl group or an amide group, and at least one of A ¹ , A ² and A ³ is an amide group. Also, A ¹ ,
A ² and A ³ may be the same as or different from each other. n is an integer from 1 to 3. M represents a transition metal of Groups 4 to 6 of the periodic table. ) Is provided, and further, the present invention is a method for producing a polyolefin, which comprises polymerizing an olefin in the presence of a catalyst comprising the above transition metal compound and a cocatalyst. .

In the above general formula CpA ¹ A ² A ³ _n M, Cp represents a cyclopentadienyl group, an indenyl group, a fluorenyl group or a derivative thereof. Specifically, cyclopentadienyl group, methylcyclopentadienyl group, dimethylcyclopentadienyl group, trimethylcyclopentadienyl group, tetramethylcyclopentadienyl group, pentamethylcyclopentadienyl group, indenyl group Three
-Methylindenyl group, 4,5,6,7-tetrahydroindenyl group, fluorenyl group, 1-methylfluorenyl group, 2,7-di-t-butylfluorenyl group, octahydrofluorenyl group, etc. Can be mentioned. A ¹ ,
A ² and A ³ are a halogen atom, a hydrogen atom, and a carbon number of 1 to 10.
Are alkyl groups, alkoxy groups, aryl groups having 6 to 20 carbon atoms, alkylaryl groups, arylalkyl groups or amide groups, and at least one of A ¹ , A ² and A ³ is an amide group. As a halogen atom,
Fluorine atom, chlorine atom, bromine atom, iodine atom,
A chlorine atom is preferred. Specific examples of the alkyl group having 1 to 10 carbon atoms, the alkoxy group, the aryl group having 6 to 20 carbon atoms, the alkylaryl group, and the arylalkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a methoxy group. , Ethoxy group, propoxy group, butoxy group, phenyl group, toluyl group, benzyl group, phenoxy group and the like. Examples of the amide group include an amide group, a methylamide, an ethylamide group, a butylamide group, an anilide group, a dimethylamide group, a diethylamide group, a trimethylsilylamide group, a trimethylsilylmethylamide group, a trimethylsilylbutylamide group, a bistrimethylsilylamide group, a trimethylsilylanilide group and a bis group. Examples thereof include a diphenylsilylamide group and a bisdimethylamide group. Of these, an amide group containing a silicon atom is preferable. M represents a transition metal of Groups 4 to 6 of the periodic table such as titanium, zirconium, hafnium, vanadium, chromium, molybdenum, and preferably titanium or zirconium. n varies depending on the valence of the transition metal M and can be an integer of 1 to 3.

Preferred examples of the above-mentioned transition metal compound of the present invention include (cyclopentadienyl) (bistrimethylsilylamido) titanium dichloride, (methylcyclopentadienyl) (bistrimethylsilylamido) titanium dichloride, (tetramethylcyclohexyl). Pentadienyl) (bistrimethylsilylamido) titanium dichloride, (pentamethylcyclopentadienyl) (bistrimethylsilylamido) titanium dichloride, (cyclopentadienyl) (bisdimethylsilylamido) titanium dichloride, (methylcyclopentadienyl)
(Bisdimethylsilylamide) titanium dichloride,
(Tetramethylcyclopentadienyl) (bisdimethylsilylamide) titanium dichloride, (Pentamethylcyclopentadienyl) (bisdimethylsilylamide)
Titanium dichloride, (cyclopentadienyl) (trimethylsilylanilide) titanium dichloride, (methylcyclopentadienyl) (trimethylsilylanilide) titanium dichloride, (tetramethylcyclopentadienyl) (trimethylsilylanilide) titanium dichloride, (pentamethylcyclopenta) (Dienyl)
Other than (trimethylsilylanilide) titanium dichloride, similar zirconium compounds can be mentioned. The transition metal compound of the present invention is characterized by having one cyclopentadienyl derivative ligand and at least one amide group ligand. These compounds can be obtained, for example, by reacting a monocyclopentadienyl transition metal compound with a corresponding metal amide compound, as described in Examples below.

In the present invention, the transition metal compound of the present invention can be used as a catalyst for olefin polymerization by combining it with a cocatalyst. As the co-catalyst used, a known co-catalyst used in combination with a metallocene compound as a catalyst for olefin polymerization can be used. A known aluminoxane can be preferably used as such a cocatalyst, and is described, for example, in JP-A-1-501950, JP-A-1-502036, and JP-A-3-179006. It is also possible to use a compound capable of stabilizing such a transition metal cation or a compound exhibiting Lewis acidity as described in JP-A-3-179005. As the aluminoxane, the following general formula

[0010]

[Chemical 1] (Wherein R represents a hydrocarbon group having 1 to 10 carbon atoms, and n is 2 or more), and particularly methylaluminoxane in which R is a methyl group, n is 5 or more, preferably 10 The above is used. The aluminoxanes may be mixed with some alkylaluminum compounds. In addition, in addition to the above, JP-A-2-247
No. 01, JP-A-3-103407 and the like, aluminoxane having two or more kinds of alkyl groups, and the fine particle aluminoxane described in JP-A-63-198691, JP-A-2- 1673
The aluminum oxy compound obtained by contacting aluminoxane with water or an active hydrogen compound described in JP-A No. 02, JP-A-2-167305 and the like can also be suitably used.

The ratio of aluminoxane to the above transition metal compound used in the present invention is 1 to 100,000.
The molar ratio is usually 10 to 10,000 times. The transition metal compound and / or aluminoxane in the present invention may be used as it is, or may be used by supporting it on a known carrier supporting a Ziegler type catalyst such as SiO ₂ , Al ₂ O ₃ and MgCl ₂ . The transition metal compound / promoter catalyst of the present invention can be used in the presence of an organoaluminum compound, if necessary. By doing so, it is possible to produce an olefin polymer with a smaller amount of aluminoxane used.

The organoaluminum compound used is represented by the general formula R ¹ _j Al (OR ² ) _k H _l X _m (wherein R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, R ^{1 1} and R ² may be the same or different from each other, X is a halogen atom, O is an oxygen atom, H is a hydrogen atom, j is an integer from 1 to 3, and k, l and m are 0. To an integer of 2, and j + k + l + m = 3) or an organoaluminum compound represented by the formula, or a mixture thereof can be used. Specific examples include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride, diisobutyl aluminum hydride, and the like. Among them, triethylaluminum and triisobutylaluminum are preferably used.

There are no particular restrictions on the polymerization method and polymerization conditions used in the method of the present invention, and a known method generally used in the polymerization of olefins may be used, such as a solvent polymerization method using an inert hydrocarbon medium, or a substantial method. The bulk polymerization method and the gas phase polymerization method in which an inert hydrocarbon medium does not exist can also be used,
The polymerization temperature is generally -100 to 200 ° C., and the polymerization pressure is generally atmospheric pressure to 100 kg / cm ² .
Preferably -50 to 100 ° C., normal pressure to 50 kg / cm ²
Is. Examples of the hydrocarbon medium used in the polymerization in the present invention include saturated hydrocarbons such as butane, pentane, hexane, heptane, octane, nonane, decane, cyclopentane and cyclohexane, and aromatics such as benzene, toluene and xylene. Hydrocarbons can also be used.

Further, the method of the present invention can be applied to copolymerization with a diene or aromatic vinyl compound for the purpose of modifying a polymer. The diene compound used at that time is 1,4-hexadiene, 4-
Methyl-1,4-hexadiene, ethylidene norbornene, dicyclopentadiene and the like can be mentioned. As the aromatic vinyl compound, styrene, o-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, o-chloro can be mentioned. Examples thereof include styrene, p-chlorostyrene, α-methylstyrene and the like.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 Synthesis of transition metal compound [(cyclopentadienyl) (bistrimethylsilylamido) titanium dichloride] Fully nitrogen-substituted 300
In a 4-necked flask with a volume of ³ cm ³ , 3.0 g of cyclopentadienyl titanium trichloride was added to 100 c of diethyl ether.
It was dissolved in m ³ . 20 cm ^{3 of} a diethyl ether solution containing 2.3 g of lithium bis (trimethylsilyl) amide was added dropwise to this solution at room temperature over 1 hour. After stirring overnight at room temperature, the precipitate was filtered off, the filtrate was cooled to about 30 cm ³ , and the precipitated orange solid was separated and dried to give 3.3 g of the title compound. The physical properties of this compound are shown below. ¹ H-NMR spectrum (90 MHz, CDCl ₃ solution) (ppm) 6.66 (s, 5H), 0.41 (s, 18H) propylene 0.75Dm ³ instrumentation in 1.5 dm ³ autoclave polymerization thoroughly purged with nitrogen Then, 10 mg of (cyclopentadienyl) (bistrimethylsilylamide) titanium dichloride synthesized above and 1.0 g of methylaluminoxane manufactured by Tosoh Akzo Co., Ltd. were charged, and polymerization was carried out at an internal temperature of 40 ° C. for 1 hour. It was Polymerization was stopped by introducing a small amount of methanol into the system, unreacted propylene was purged, and the obtained polymer was dried to obtain 8.2 g of atactic polypropylene.

[0016]

By utilizing the novel transition metal compound of the present invention,
By carrying out the method of the present invention, a polyolefin can be efficiently produced, which is industrially extremely valuable.

Claims (3)

[Claims] ^1. A general formula CpA ¹ A ² A ³ _n M (where Cp represents a cyclopentadienyl group, an indenyl group, a fluorenyl group or a derivative thereof).
A ¹ , A ² and A ³ are halogen atom, hydrogen atom, carbon number 1
Alkyl groups up to -10, alkoxy groups, C6-2
It is an aryl group up to 0, an alkylaryl group, an arylalkyl group or an amide group, and at least one of A ¹ , A ² and A ³ is an amide group. Also, A ¹ ,
A ² and A ³ may be the same as or different from each other. n is an integer from 1 to 3. M represents a transition metal of Groups 4 to 6 of the periodic table. ) A new transition metal compound represented by. 2. A method for producing a polyolefin, which comprises polymerizing an olefin in the presence of a catalyst comprising the transition metal compound according to claim 1 and a cocatalyst. 3. The method for producing a polyolefin according to claim 2, wherein the cocatalyst is aluminoxane.