JPH04353502A - Production of olefin polymer - Google Patents

Abstract

PURPOSE:To obtain an alpha-olefin polymer in high efficiency and in an industrially stable way by using a highly active catalyst of excellent stability without the need for a large quantity of an organoaluminum compound. CONSTITUTION:An alpha-olefin is polymerized using a catalyst comprising the compounds A and B and, when needed, the compound C, described below, respectively, into the objective polymer. (A) a transition metal compound (said transition metal is selected from group IVB metals); (B) an aryl- or alkyl-substituted boron compound; and (C) an organoaluminum compound.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an olefin polymer,
More specifically, the present invention relates to a method for efficiently producing an α-olefin homopolymer or a copolymer of two or more α-olefins.

0002

BACKGROUND OF THE INVENTION Kaminsky catalysts containing transition metal compounds and aluminoxane have been known as soluble olefin polymerization catalysts. For example, in the polymerization of α-olefins, a catalyst consisting of a zirconium compound and aluminoxane shows high polymerization activity (Japanese Unexamined Patent Publication No. 19309/1982), and a compound in which two indenyl groups are bonded via an ethylene group is used. Producing stereoregular polypropylene using a catalyst consisting of a zirconium compound as a ligand and aluminoxane (JP-A-61-13
No. 0314) and the like are publicly known. According to this Kaminsky catalyst, for example, in the polymerization of propylene, it is said that any of isotactic polypropylene, atactic polypropylene, and syndiotactic polypropylene can be produced (Makromo
l. Chem. , Rapid Commun. 4,41
7-421 (1983); Angew. Chem. In
t. Ed. Engl. 24, 507-508 (1985
);J. Am. Chem. Soc. 109,6544-
6545 (1987); J. Am. Chem. Soc.
110, 6255-6256 (1988)).

In this case, transition metal compounds for producing isotactic polyolefins include transition metal compounds having ethylene bis(indenyl) ligands (JP-A-61-264010, JP-A-64-51408). , JP-A No. 64-66216), R by Yuen et al.
C5(R')4)2MeQp type metallocene compounds (JP-A-63-251405, JP-A-63-295607, JP-A-64-74202), metallocene compounds cross-linked with silicon etc. (JP-A-3-12406) No.) etc. are known. Furthermore, metallocene compounds for producing stereoblock polymers are also known (JP-A-63-142004, JP-A-63-2005).

0004

However, the above-mentioned polymerization method has the problem that sufficient activity cannot be obtained unless expensive aluminoxane is used at a high ratio of 100 to 10,000 times the amount of the transition metal compound. be. In addition, since a large amount of aluminoxane is used, a large amount of metal remains in the product after polymerization, leading to polymer deterioration and
This may cause discoloration, etc. Therefore, there are problems in terms of productivity, such as the need to thoroughly demineralize the product after polymerization. Furthermore, the production of aluminoxane requires the reaction of highly reactive trimethylaluminum with water, which is dangerous, and the reaction product is a mixture of various substances including unreacted raw materials. Since it is very difficult to isolate a single substance, it is extremely difficult to control the catalyst to obtain a product with stable physical properties.

[0005] On the other hand, α
- A method for polymerizing olefins is also shown (Special Table of Contents Hei 1-5
No. 02036). However, the catalyst used in this method has extremely low polymerization activity and is difficult to use industrially. Furthermore, the stability of the specific boron complex is not sufficient.

[0006] Furthermore, a method for polymerizing olefins in which a cation-like complex of a specific transition metal compound and a boron compound is prepared, isolated, and used as a catalyst has been reported (J. Am. Chem. Soc., 113, No. 9,
1991, 3623-3625). However, the above method requires the isolation step of the complex compound, which complicates the production process, and the isolated complex compound is unstable. Therefore, this method is not practical as an industrial method for producing olefin polymers. Poor. The present invention was made in view of the above circumstances, and α
- The purpose is to provide a production method that allows olefin polymers to be produced efficiently and industrially stably using a highly active catalyst with excellent stability without using large amounts of organoaluminum compounds. do.

[0007]

[Means and effects for solving the problem] As a result of various studies in order to solve the problems in the above-mentioned conventional methods, the present inventors have found that a method containing a transition metal selected from group IVB of the periodic table. When a transition metal compound and an aryl- or alkyl-substituted boron compound are added to the polymerization system as a catalyst, an olefin polymer can be efficiently produced without using a large amount of aluminoxane, and the transition metal compound and boron compound We have found that this method is industrially advantageous in terms of the catalyst manufacturing process and catalyst stability, compared to the case where a complex is prepared in advance and then used as a catalyst after isolation.
The present invention has been accomplished.

Therefore, the present invention provides the following compound (A)
and (B) or the following compounds (A), (B) and (
Provided is a method for producing an olefin polymer, characterized in that α-olefin is polymerized or copolymerized using C) as a catalyst. (A) Transition metal compound containing a transition metal selected from Group IVB of the periodic table (B) Aryl or alkyl substituted boron compound (C) Organoaluminum compound

The present invention will be explained in more detail below. In the present invention, the compound (A) is I of the periodic table.
A transition metal selected from group VB, namely titanium (T
i), zirconium (Zr) or hafnium (Hf)
Any compound can be used as long as it contains the following general formula (I), (II) or (III).
A cyclopentadienyl compound represented by or a derivative thereof or a compound represented by the following general formula (IV) or a derivative thereof is preferable.

CpM1R1aR2bR3c
…(I) Cp2M
1R1dR2e
...(II) (Cp-Af-Cp)
M1R1dR2e...
(III) M1R1gR2hR3iR4j
…(IV
) [In the formulas (I) to (IV), M1 represents a Ti, Zr or Hf atom, and Cp represents a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a tetrahydroindenyl group, Indicates a substituted tetrahydroindenyl group, fluorenyl group, or substituted fluorenyl group. R1, R2, R3 and R4 are each a hydrogen atom, an oxygen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a carbon number 6 to
20 aryl group, alkylaryl group or arylalkyl group, acyloxy group having 1 to 20 carbon atoms, allyl group, substituted allyl group, acetylacetonato group, substituted acetylacetonato group, substituent containing a silicon atom, or carbonyl , an oxygen molecule, a nitrogen molecule, a Lewis base, a chain unsaturated hydrocarbon or a cyclic unsaturated hydrocarbon, and A represents a crosslinking by a covalent bond. a, b and c are each an integer of 0 to 3, and d and e are each an integer of 0 to 3.
f is an integer of 0 to 6, g, h, i and j are integers of 0 to 4, respectively. Two or more of R1, R2, R3 and R4 may be bonded to each other to form a ring. When Cp has a substituent, the substituent is preferably an alkyl group having 1 to 20 carbon atoms. (II)
In formula and formula (III), two Cp may be the same or different. ]

Examples of the substituted cyclopentadienyl group in formulas (I) to (III) above include methylcyclopentadienyl group, ethylcyclopentadienyl group, isopropylcyclopentadienyl group, 1,2-dimethyl cyclopentadienyl group, tetramethylcyclopentadienyl group, 1,3-dimethylcyclopentadienyl group,
1,2,3-trimethylcyclopentadienyl group, 1,
Examples include 2,4-trimethylcyclopentadienyl group, pentamethylcyclopentadienyl group, and trimethylsilylcyclopentadienyl group. Specific examples of R1 to R4 include, for example, F, Cl, B as a halogen atom.
r, I; methyl group as an alkyl group having 1 to 20 carbon atoms,
Ethyl group, n-propyl group, iso-propyl group, n-
Butyl group, octyl group, 2-ethylhexyl group; methoxy group, ethoxy group, propoxy group, butoxy group, phenoxy group; carbon number 6 as an alkoxy group with 1 to 20 carbon atoms
A phenyl group, tolyl group, xylyl group, benzyl group as an aryl group, alkylaryl group or arylalkyl group having ~20; heptadecylcarbonyloxy group as an acyloxy group having 1 to 20 carbon atoms; trimethylsilyl as a substituent containing a silicon atom group, (trimethylsilyl)methyl group: As a Lewis base, ethers such as dimethyl ether, diethyl ether, and tetrahydrofuran, thioethers such as tetrahydrothiophene, esters such as ethyl benzoate, nitriles such as acetonitrile and benzonitrile, trimethylamine, triethylamine, and Butylamine, N,N-dimethylaniline,
Amines such as 2,2'-bipyridine and phenanthroline, phosphines such as triethylphosphine and triphenylphosphine; chain unsaturated hydrocarbons such as ethylene, butadiene, 1-pentene, isoprene, pentadiene,
1-hexene and derivatives thereof; Examples of cyclic unsaturated hydrocarbons include benzene, toluene, xylene, cycloheptatriene, cyclooctadiene, cyclooctatriene, cyclooctatetraene, and derivatives thereof. Examples of the covalent bond crosslinking of A include methylene crosslinking, dimethylmethylene crosslinking, ethylene crosslinking,
Examples include dimethylsilylene crosslinking, dimethylgermylene crosslinking, dimethylstanylene crosslinking, and the like.

Among the compounds of formulas (I) to (III), particularly preferred are at least two of R1 to R3 in the compound of formula (I), and R1 in the compounds of formulas (II) and (III). , R2 has 1 to 1 carbon atoms.
It is an alkyl group having 20 carbon atoms or an aryl group having 6 to 20 carbon atoms. Examples of such compounds include the following and compounds in which zirconium in these compounds is replaced with titanium or hafnium. Compounds of formula (I) (pentamethylcyclopentadienyl)trimethylzirconium, (pentamethylcyclopentadienyl)triphenylzirconium, (pentamethylcyclopentadienyl)tribenzylzirconium, (cyclopentadienyl)trimethylzirconium, (Cyclopentadienyl)triphenylzirconium, (cyclopentadienyl)tribenzylzirconium, (methylcyclopentadienyl)trimethylzirconium, (methylcyclopentadienyl)triphenylzirconium, (methylcyclopentadienyl)tribenzyl zirconium,(
(tetramethylcyclopentadienyl)trimethylzirconium, (dimethylcyclopentadienyl)trimethylzirconium, (trimethylcyclopentadienyl)trimethylzirconium, (trimethylsilylcyclopentadienyl)trimethylzirconium, (cyclopentadienyl)dimethyl (methoxy) Zirconium, (methylcyclopentadienyl)dimethyl(methoxy)zirconium,

(II) compound bis(cyclopentadienyl)dimethylzirconium of formula;
Bis(cyclopentadienyl)diphenylzirconium, bis(cyclopentadienyl)diethylzirconium, bis(cyclopentadienyl)dibenzylzirconium, bis(cyclopentadienyl)dimethoxyzirconium, bis(cyclopentadienyl)dichlorozirconium , bis(methylcyclopentadienyl)dimethylzirconium, bis(pentamethylcyclopentadienyl)dimethylzirconium, bis(methylcyclopentadienyl)dibenzylzirconium, bis(pentamethylcyclopentadienyl)dibenzylzirconium, bis (pentamethylcyclopentadienyl) chloromethylzirconium, bis(pentamethylcyclopentadienyl)hydridomethylzirconium,

Compounds of formula (III) ethylenebis(indenyl)dimethylzirconium, ethylenebis(tetrahydroindenyl)dimethylzirconium, dimethylsilylenebis(cyclopentadienyl)dimethylzirconium, isopropylidene(9-fluorenyl)(cyclopentadienyl) enyl)dimethylzirconium, [methyl(phenyl)methylene](9-fluorenyl)(cyclopentadienyl)dimethylzirconium, (diphenylmethylene)(9-fluorenyl)(cyclopentadienyl)dimethylzirconium, ethylidene(9-fluorenyl) (cyclopentadienyl)dimethylzirconium, (cyclohexyl)(9-fluorenyl)(cyclopentadienyl)dimethylzirconium,
(cyclopentyl) (9-fluorenyl) (cyclopentadienyl) dimethylzirconium, (cyclobutyl)
(9-fluorenyl)(cyclopentadienyl)dimethylzirconium, (dimethylsilylene)(9-fluorenyl)(cyclopentadienyl)dimethylzirconium,

[0015] Furthermore, the above general formulas (I), (II), (I
Compounds other than the cyclopentadienyl compound represented by II) do not impair the effects of the present invention. Examples of such compounds include the compound of formula (IV) above,
Examples include titanium compounds, zirconium compounds, and hafnium compounds having an alkyl group and/or alkoxy group, such as tetrabenzylzirconium and bis(2,5-di-t-butylphenoxy)dimethylzirconium.

Furthermore, in the present invention, compound (A)
is a polydentate group in which two substituted or unsubstituted conjugated cycloalkadienyl groups (at least one of which is a substituted cycloalkadienyl group) are bonded to each other via an element selected from group IVA of the periodic table. A group IVB transition metal compound having a coordination compound as a ligand can be suitably used, and thereby an isotactic polyolefin having high isotacticity, high molecular weight, and high melting point can be obtained. Such compounds include, for example,
Compounds represented by the following general formula (V) or derivatives thereof can be mentioned.

[0017]

[Formula (V), Y is carbon, silicon, germanium or tin atom, R5t-C5H4-t and R5u-C5H4-u
each represents a substituted cyclopentadienyl group, and t and u represent an integer of 1 to 4. Here, R5 represents a hydrogen atom, a silyl group, or a hydrocarbon group, and may be the same or different. Furthermore, in at least one cyclopentadienyl ring, R5 is present on at least one carbon adjacent to the carbon bonded to Y. R6 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, alkylaryl group, or arylalkyl group having 6 to 20 carbon atoms. M2 is a Ti, Zr or Hf atom; Indicates the group. X may be the same or different, and R6 may be the same or different.

Examples of the substituted cyclopentadienyl group in the above formula (V) include methylcyclopentadienyl group, ethylcyclopentadienyl group, isopropylcyclopentadienyl group, and 1,2-dimethylcyclopentadienyl group. group, 1,3-dimethylcyclopentadienyl group, 1,2,3-trimethylcyclopentadienyl group, 1
, 2,4-trimethylcyclopentadienyl group, and the like. Specific examples of X include F, Cl, Br, I as a halogen atom; methyl group, ethyl group, n-propyl group, iso
-propyl group, n-butyl group, octyl group, 2-ethylhexyl group; methoxy group, ethoxy group, propoxy group, butoxy group, phenoxy group as an alkoxy group having 1 to 20 carbon atoms; aryl group having 6 to 20 carbon atoms, phenyl group as alkylaryl group or arylalkyl group,
Examples include tolyl group, xylyl group, and benzyl group. R
Specific examples of 6 include a methyl group, an ethyl group, a phenyl group, a tolyl group, a xylyl group, a benzyl group, and the like.

Examples of such compounds of formula (V) include the following and compounds in which zirconium in these compounds is replaced with titanium or hafnium. Compound of formula (V) Dimethylsilylbis(2,3,5-trimethylcyclopentadienyl)zirconium dichloride, Dimethylsilylbis(2,3,5-trimethylcyclopentadienyl)hafnium dichloride

In the present invention, the compound (B) is not particularly limited as long as it is a boron compound in which an aryl group or an alkyl group is bonded as a substituent to boron, and any compound can be used. Here, the aryl substituent includes a halogen-substituted aryl group and an alkyl-substituted aryl group, and the alkyl substituent includes a halogen-substituted alkyl group. Further, the number of aryl or alkyl substituents is 1 to 3, but when the number of aryl or alkyl substituents is 2 to 3, these may be the same or different from each other. Furthermore, when there are 1 to 2 aryl or alkyl substitutions, there are no limitations on the types of other atoms or groups bonded to boron, and they may be arbitrary atoms such as hydrogen atoms and halogen atoms. However, the aryl- or alkyl-substituted boron compound preferably has a Lewis acid strength between that of boron trichloride and boron trifluoride.

Specific examples of boron compounds used as compound (B) include triphenylboron, tri(pentafluorophenyl)boron, tri[3,5-di(trifluoromethyl)phenyl]boron, tri[( 4-fluoromethyl)phenyl]boron, trimethylboron, triethylboron, tri(n-butyl)boron, tri(trifluoromethyl)boron, tri(pentafluoroethyl)boron, tri(nonafluorobutyl)boron, tri(2) ,4,6-trifluorophenyl)boron, tri(3,5-difluorophenyl)boron, di(pentafluorophenyl)fluoroboron, diphenylfluoroboron, di(pentafluorophenyl)chloroboron, dimethylfluoroboron, diethylfluoroboron Boron, di(n-butyl)fluoroboron, (pentafluorophenyl)difluoroboron, phenyldifluoroboron, (pentafluorophenyl)dichloroboron,
Methyldifluoroboron, ethyldifluoroboron, (n-
butyl) difluoroboron. Among these, tri(pentafluorophenyl)boron is particularly preferred.

[0022] Next, the organoaluminum compound as component (C) used to further increase the catalytic activity is as follows:
Examples include those represented by the following general formula (VI), (VII) or (VIII). R7rAlQ3-r
...(VI)(R
7 represents a hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms, such as an alkyl group, an alkenyl group, an aryl group, an aralkyl group, and Q represents a hydrogen atom or a halogen atom. r is in the range of 1≦r≦3. ) Specifically, they include trimethylaluminum, triethylaluminum, triisobutylaluminum, dimethylaluminum chloride, diethylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, and the like.

[0023]

A chain aluminoxane represented by [Chemical formula 2]. (R7 is the formula (VI)
shows the same thing as. s represents the degree of polymerization, usually 3 to 50
It is. )

[0024]

A cyclic alkylaluminoxane having a repeating unit represented by the following formula. (R7 represents the same as formula (VI). Also, s represents the degree of polymerization, and the preferred number of repeating units is 3 to
It is 50. ) Among the compounds of formulas (VI) to (VIII), the compound of formula (VI) is preferred, and the compound of formula (VI) is particularly preferred.
Compounds of formula VI) in which r=3, especially trialkylaluminums such as trimethylaluminum, triethylaluminum, triisobutylaluminum.

[0025] Examples of the method for producing the aluminoxane include a method of bringing an alkyl aluminum into contact with a condensing agent such as water, but the method is not particularly limited, and the reaction may be carried out according to a known method. For example, ■ a method in which an organoaluminum compound is dissolved in an organic solvent and then brought into contact with water; ■ a method in which an organoaluminum compound is added initially during polymerization and then water is added; There are methods such as reacting crystallized water that exists in organic materials and water adsorbed on inorganic or organic materials with organoaluminum compounds.

The catalyst used in the present invention is the above compound (A)
and compound (B) as the main components, and preferably further contains an organoaluminum compound (C). Here, the conditions for using compound (A) and compound (B) are not particularly limited, but the ratio (molar ratio) of compound (A):compound (B) is 1:0.1 to 1:10, particularly 1: 0.5～
The ratio is preferably 1:5. Operating temperature is -50 to 25
The temperature is preferably in the range of 0°C, and the pressure and time can be set arbitrarily. Further, the amount of the organoaluminum compound (C) used is usually 0 to 100 mol per 1 mol of the compound (A). Organoaluminum compound (C
) can significantly improve polymerization activity, but if too much is used, the organoaluminum compound will be wasted. In addition, in the present invention, the compounds (A) and (B) or the compounds (A), (B), and (C) may be used in contact with each other in advance, or may be used in contact with each other within the polymerization system. Good too. However, isolating the complex obtained by contacting compounds (A) and (B) as crystals poses a problem in terms of the stability of the catalyst. Therefore, the present invention does not use the above-mentioned isolated complex as a catalyst. do not have.

In the present invention, homopolymerization of an α-olefin or copolymerization of two or more α-olefins is carried out in the above polymerization system. In this case, the type of α-olefin is not particularly limited, but those having 2 to 20 carbon atoms are preferred. Specifically, ethylene, propylene, 1-butene, 3-
Methyl-1-butene, 1-hexene, 4-methyl-1-
Pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, etc. can be preferably used. In the present invention, when copolymerizing two or more types of α-olefins, the above monomers can be arbitrarily combined, but it is particularly preferable to copolymerize ethylene and an α-olefin having 3 to 10 carbon atoms. In the present invention, in addition to the above α-olefin, a small amount of other unsaturated compounds such as vinyl aromatic compounds such as styrene, p-methylstyrene, isopropylstyrene, and t-butylstyrene can be used for copolymerization. Usually, the amount of the vinyl aromatic compound is 20 mol% or less based on the α-olefin. In this case, one or more α-olefins can be preferably used.

In the present invention, the polymerization method is not limited, and any method such as bulk polymerization, solution polymerization, suspension polymerization, etc. may be used. Regarding polymerization conditions, the polymerization temperature is -50 to 250
The temperature is preferably 20 to 100°C. Also,
The ratio of the catalyst to the reaction raw material is preferably 1 to 108, particularly 100 to 105, for raw material monomer/transition metal (mole ratio) and raw material monomer/boron compound (molar ratio). Further, the polymerization time is usually 5 minutes to 10 hours, and the reaction pressure is normal pressure to 100 kg/cm2G, preferably normal pressure to 30 kg/cm2G.

When using a polymerization solvent, for example, aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene, alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclohexane, and fatty acids such as pentane, hexane, heptane, and octane. Group hydrocarbons, chloroform, halogenated hydrocarbons such as dichloromethane, etc. can be used. These solvents may be used alone or in combination of two or more. Furthermore, monomers such as α-olefins may be used as the solvent.

[0030]

[Examples] Next, the present invention will be specifically illustrated by examples, but the present invention is not limited to the following examples. Example 1: Polymerization of ethylene 400 ml of toluene, 0.005 mmol of tri(pentafluorophenyl)boron and 0.005 mmol of biscyclopentadienyldimethylzirconium are added to a 500 ml autoclave which has been dried and purged with nitrogen. Next, ethylene was continuously supplied to the autoclave at 80°C so that the pressure inside the system was 7 kg/cm2,
Polymerization was carried out for 10 minutes to obtain 24.2 g of polyethylene. Example 2: Polymerization of ethylene Polymerization was carried out in the same manner as in Example 1 except that 0.2 mmol of triisobutylaluminum was further added to obtain 56.0 g of polyethylene.

Example 3: Polymerization of ethylene Same as Example 2 except that biscyclopentadienyldichlorozirconium was used instead of biscyclopentadienyldimethylzirconium and the polymerization time was 60 minutes. Polymerization was carried out to obtain 18.7 g of polyethylene. Example 4: Polymerization of ethylene In a 500 ml autoclave that had been dried and purged with nitrogen, 400 ml of toluene and 1 ml of triisobutylaluminum were added.
mmol, tetrabenzylzirconium 0.05mmol
l, tri(pentafluorophenyl) boron 0.05mm
ol was added to the autoclave, and ethylene was continuously supplied to the autoclave at 80° C. so that the pressure within the system was 7 kg/cm 2 , and polymerization was carried out for 1 hour to obtain polyethylene.

Example 5: Polymerization of propylene In a 500 ml autoclave that had been dried and purged with nitrogen, 4 toluene was added.
00ml, triisobutylaluminum 0.2mmol
, ethylenebis(indenyl)dimethylzirconium0
．． 0.005 mmol and 0.005 mmol of tri(pentafluorophenyl)boron are added. Next, propylene was continuously supplied to the autoclave at 30°C so that the pressure in the system was 7 kg/cm2, and polymerization was carried out for 1 hour.
8.9 g of polypropylene was obtained. This polypropylene was confirmed to be isotactic polypropylene by IR and 13C-NMR.

Example 6: Polymerization of propylene Polymerization was carried out in the same manner as in Example 5, except that cyclopentadienyl (isopropyl) fluorenyl dimethyl zirconium was used in place of ethylenebis(indenyl)dimethylzirconium. , 7.7 g of polypropylene was obtained. This polypropylene was confirmed to be syndiotactic polypropylene by IR and 13C-NMR.

Comparative Example First, 5 mmol of biscyclopentadienyldimethylzirconium and tri(pentafluorophenyl)boron were reacted, and the resulting biscyclopentadienylmethylzirconium tri(pentafluorophenyl)methylborate complex was isolated. did. Add 400 ml of toluene and 0.005 mmol of the above isolated complex to a 500 ml autoclave that has been dried and purged with nitrogen, and then continuously supply ethylene to the autoclave at 80°C so that the pressure in the system becomes 7 kg/cm2. When polymerization was carried out for 10 minutes, 5.3 g of polyethylene was obtained. The catalyst used in this comparative example had significantly lower catalytic activity than the catalyst used in Example 1.

[0035]

Effects of the Invention As explained above, according to the method for producing olefin polymers of the present invention, olefins can be produced efficiently and stably using a highly active catalyst with excellent stability without using a large amount of organoaluminum compounds. based polymers can be produced. In addition, the process of preparing and isolating a complex is not required, which simplifies the process of producing the catalyst, and there is no problem in terms of stability of the catalyst. Therefore, the production method of the present invention is industrially extremely advantageous in terms of productivity and the like as a method for producing olefin polymers.

[0036]

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the manufacturing method of the present invention.

Claims (1)

[Claims] [Claim 1] The following compound (A) and compound (B)
1. A method for producing an olefin polymer, which comprises polymerizing an α-olefin using as a catalyst. (A) A transition metal compound containing a transition metal selected from group IVB of the periodic table. (B) An aryl- or alkyl-substituted boron compound.Claim 2: The compound (A) and the compound (B) according to claim 1.
) and an organoaluminum compound (C) as a catalyst to polymerize an α-olefin.