JP3473144B2 - Olefin polymerization catalyst and method for producing ethylene-α-olefin copolymer - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel Ziegler catalyst and a process for producing an ethylene-α-olefin copolymer using the catalyst.

[0002]

BACKGROUND OF THE INVENTION Olefin copolymers, especially ethylene-α-olefin copolymers, are used in films, laminates,
It is used in numerous applications such as wire coatings, injection molded products and special molded products. The basic physical properties of the ethylene / α-olefin copolymer are determined by the amount and distribution of the comonomer introduced into the ethylene chain. That is, the number and distribution of short chain branches have a great influence on basic properties such as crystallinity, crystallization rate, spherulite structure and melting point. Consequently, from the viewpoint of practical physical properties, it will affect many aspects such as environmental stress resistance, film strength, flexibility, and moldability. From the above, it is very important to control the number of short chain branches and the distribution thereof in the ethylene-α-olefin copolymer in order to improve practical physical properties.

As a method for producing an olefin copolymer, generally, a so-called Ziegler-Natta catalyst comprising a transition metal compound of Group IV to VI and an organometallic compound of Group I to III of the periodic table is used. Is widely known.

In recent years, a catalyst system composed of a metallocene compound of a transition metal and an aluminoxane has been proposed as a new catalyst system (for example, JP-A-58-19309). These catalysts have been attracting attention in terms of polymerization activity and the like, but they have the drawback of requiring a large amount of aluminoxane. Further, JP-A-5-65308 discloses the result of copolymerization of ethylene-α-olefin in a catalyst system composed of a zirconium compound and aluminoxane, but the copolymerizability of the catalyst system is not always satisfactory. . Further, it has been reported that increasing the α-olefin content in the ethylene-α-olefin copolymer lowers the molecular weight of the copolymer (Makr.
omol. Chem. 193, 823 (1992)),
This is a problem in producing a polymer having a good balance between the α-olefin content and the molecular weight of the copolymer. Further, a method using a catalyst composed of an ionic metallocene catalyst and an alkylaluminum, a reaction product of a halogenated metallocene compound and an organometallic compound, and a catalyst composed of a stable anion has been proposed (JP-A-3-207704, International Publication No. 3-207704). Publication WO92 / 01723). However, all of these methods use expensive zirconium compounds and hafnium compounds, and it is said that they can be used for other inexpensive transition metal compounds, but no specific method or result is shown.

Further, there has been proposed a method for producing a polyolefin by a catalyst system containing a compound that forms an ionic complex by reacting a titanium compound with a transition metal compound and an organoaluminum compound as main components (Japanese Patent Laid-Open No. HEI 5). -23
0133, JP-A-5-331228, and JP-A-6-192330). However, specific examples are those in which an alkoxy group or a cyclopentadienyl ring is used as a ligand, and the copolymerizability thereof is not always satisfactory.

On the other hand, as a method for polymerizing or copolymerizing an olefin using a catalyst system comprising a compound having a titanium-nitrogen bond and an organoaluminum compound, a method comprising using a catalyst system comprising a titanium diphenylamide compound and an organoaluminum compound. (JP0104374, JP-B-42-11646), a method using a catalyst system composed of a titanium amide compound having an aryl substituent and an organic aluminum compound (JP-B-42-22691), and further dimethylamide titanium trichloride. And the like using a catalyst system composed of a titanium amide compound having a lower alkyl group and an organic aluminum compound (J.
of Polym. Sci. Part A-1,241,
6 (1968)) and the like have been proposed. However, even if the copolymerization of ethylene and α-olefin is carried out by using the catalyst system disclosed therein, for example, EP010437
4, Japanese Patent Publication No. 42-11646, Japanese Patent Publication No. 42
-22691, and J. of Polym. S
ci. The methods disclosed in Part A-1, 241, 6 (1968) and the like are still unsatisfactory in catalytic activity and copolymerizability.

Therefore, in order to solve these problems, the present applicant first (A) formula (R1R2N) 4- (m + n) T.
iXm Yn (wherein R 1 and R 2 are saturated hydrocarbon groups having 8 to 30 carbon atoms, X is halogen, Y is alkoxy group, m
Is a number 1 ≦ m ≦ 3, and n is a number 0 ≦ n ≦ 2 (m +
n) is 1 ≦ (m + n) ≦ 3. ), A method for producing ethylene and α-olefin copolymers by using a liquid catalyst component composed of a titanium amide compound and a catalyst system composed of an organoaluminum compound has been proposed (JP-A-2-77412). . However, in the production method using the catalyst system, the catalytic activity is not sufficient in view of the object of the present application, and the copolymerizability is not yet satisfactory.

[0008]

Under the present circumstances,
The problem to be solved by the present invention, that is, the object of the present invention is to provide a novel catalyst system, and by using such a novel catalyst, ethylene and α-olefin can be efficiently copolymerized to obtain a content of α-olefin. To provide a method for producing a high molecular weight ethylene-α-olefin copolymer.

[0009]

Means for Solving the Problems That is, the present invention provides a titanium amide compound (A) having a titanium-nitrogen bond, a compound (B) which reacts with a transition metal compound to form a stable anion, and an organoaluminum compound (C). And a method for producing an ethylene-α-olefin copolymer using the catalyst.

The present invention will be described in detail below. First, the titanium amide compound (A) referred to in the present invention is represented by the following general formula:
It is a titanium amide compound represented by [I]. (In the formula, R ^{1 to} R ⁴ represent a hydrocarbon group having 1 to 20 carbon atoms.
However, they may be the same or different. X is an oxygen atom
It R ⁵ and R ⁶ are hydrocarbon groups having 1 to 20 carbon atoms or halo
Represents a gen atom. )

[0011]

[0012]

[0013]

[0014]

A titanium amide compound represented by the general formula [I]
In the compound, R ^{1 to} R ⁴ are methyl group, ethyl group, propyl
Group, butyl group, pentyl group, hexyl group, heptyl group,
A hydrocarbon group having 1 to 20 carbon atoms such as an octyl group is exemplified.
Be done. Further, those represented by R ⁵ and R ⁶ are halogen.
Examples of the hydrocarbon group include chlorine, bromine, iodine, etc.
Are methyl, ethyl, propyl, butyl, 2
-Ethylhexyl group, octyl group, decyl group, dodecyl
Groups, alkyl groups such as cycloalkyl groups; phenyl groups,
Aryl groups such as ryl group and naphthyl group;
Rachel group is mentioned, Preferably it is C1-C20.
It may be a hydrocarbon group, but more preferably an aromatic ring
It is desirable to have one. Further, X is an oxygen atom.

Specific examples of such compounds include 2,
2'-oxobis (N-methylanilino) titanium dichloride, 2,2'-oxobis (N-ethylanilino) titanium dichloride, 2,2'-oxobis [N
-(N-propyl) anilino] titanium dichloride,
2,2'-oxobis (N-isopropylanilino) titanium dichloride, 2,2'-oxobis (Nn-
Butylanilino) titanium dichloride, 2,2′-oxobis (N-2-butylanilino) titanium dichloride, 2,2′-oxobis (N-isobutylanilino) titanium dichloride, 2,2′-oxobis (N
-T-butylanilino) titanium dichloride, 2,
2'-oxobis (N-pentylanilino) titanium dichloride, 2,2'-oxobis (N-hexylanilino) titanium dichloride, 2,2'-oxobis (N-octylanilino) titanium dichloride, 2,
2'-oxobis (N-methylanilino) dibenzyltitanium, 2,2'-oxobis (N-ethylanilino) dibenzyltitanium, 2,2'-oxobis [N
-(N-propyl) anilino] dibenzyltitanium,
2,2'-oxobis (N-isopropylanilino) dibenzyltitanium, 2,2'-oxobis (Nn-)
Butylanilino) dibenzyltitanium, 2,2'-oxobis (N-2-butylanilino) dibenzyltitanium, 2,2'-oxobis (N-isobutylanilino) dibenzyltitanium, 2,2'-oxobis (N
-T-butylanilino) dibenzyltitanium, 2,
2'-oxobis (N-pentylanilino) dibenzyltitanium, 2,2'-oxobis (N-hexylanilino) dibenzyltitanium, 2,2'-oxobis (N-octylanilino) dibenzyltitanium, etc. Is mentioned.

[0017]

[0018]

Examples of the method for synthesizing the titanium amide compound represented by the general formula [I] include D. C. Bradley
et al. J. Chem. Soc. (196
0), 3857. E. Benzing et al. C
hem. The methods described in Ber, 94 (1961), 2263 and the like can be used in combination.

General formula[I]Titanium amide compound represented by
According to these methods, for example (i)General formula R ⁷
NHR ⁸ XR ⁹ NHR ^Ten (However,R ⁷ ~ R ^Ten Has 1 carbon
~ 30 hydrocarbon groups, which may be the same or different.
Yes.X is an oxygen atom. ) Secondary amine compound represented by
Things and (ii)(R ¹¹ R ¹² N) _Four Ti(However,R ¹¹ And R
¹² Represents a hydrocarbon group having 1 to 30 carbon atoms, which may be the same or different.
You may ) With a titanium amide compound represented by
React, then (iii) general formula TiZ ¹ _Four(However,Z ¹
Represents a halogen atom such as chlorine, bromine or iodine, and is preferably
IsZ ¹ Is a chlorine atom. ) Titanium tetrahalide represented by
And (iv)General formula R ¹³ CH ₂ MgZ
² (However,Z ² Is a halogen atom such as chlorine, bromine or iodine
Represent, preferablyZ ² Is a chlorine atom. ) With
Can be synthesized.

Further, as an example of the compound (B) which reacts with the transition metal compound used in the present invention to form an ionic complex, a complex compound composed of an anion in which a plurality of groups are bound to boron and a cation is mentioned. be able to.
Specific examples of such complex compounds include triethylammonium tetraphenylborate, dimethylanilinium tetraphenylborate, trimethylsulfonium triethylammonium tetraphenylborate, triethylammonium tetra (pentafluorophenyl) borate, and tetra (pentafluorophenyl) dimethylanilinium. Trimethylsulfonium tetra (pentafluorophenyl) borate, trityl tetra (pentafluorophenyl) borate,
Ferrocenium tetraphenylborate, ferrocenium tetra (pentafluorophenyl) borate, tetraphenylborate (tetraphenylporphyrin manganese), lithium tetraphenylborate, sodium tetraphenylborate, potassium tetraphenylborate, magnesium tetraphenylborate, tetra (pentafluorophenyl) Examples thereof include lithium borate, sodium tetra (pentafluorophenyl) borate, potassium tetra (pentafluorophenyl) borate, magnesium tetra (pentafluorophenyl) borate, and their ether complexes and tetrahydrofuran complexes.

In the present invention, a known organoaluminum compound can be used as the organoaluminum compound (C). Examples of the organic aluminum compound include those represented by the general formula
An organoaluminum compound represented by R ¹⁴ _a AlZ ³ _3-a is preferably used.

AboveR ¹⁴ Is a hydrocarbon group having 1 to 20 carbon atoms,
It is preferably a hydrocarbon group having 1 to 10 carbon atoms.Z ³  Is
A hydrogen atom and / or an alkoxy group having 1 to 20 carbon atoms
It Also, a is a number 0 <a ≦ 3. General formulaR ¹⁴ _a
AlZ ³ _3-a Of the organoaluminum compound (C)
Specific examples include trimethylaluminum and triethyl.
Aluminum, tripropyl aluminum, triisobu
Chill aluminum, trihexyl aluminum, trio
Tributyl aluminum, tridecyl aluminum, etc.
Alkyl aluminum, dimethyl aluminum hydra
Id, diethyl aluminum hydride, dipropyl
Aluminum hydride, diisobutyl aluminum
Hydride, dihexyl aluminum hydride,
Dioctyl Aluminum Hydride, Didecyl Aluminum
Dialkylaluminum hydride such as nium hydride
Ride, methoxymethylaluminum hydride,
Toxyethyl aluminum hydride, methoxyiso
Butyl aluminum hydride, ethoxyhexyl ure
Luminium hydride, ethoxyoctylaluminium
Mu hydride, ethoxydecyl aluminum hydra
Alkoxyalkyl aluminum hydride such as id
, Dimethyl aluminum methoxide, methyl aluminum
Umdimethoxide, diethylaluminum methoxide,
Ethyl aluminum dimethoxide, diisobutyl aluminum
Aluminum methoxide, isobutyl aluminum dimethoxy
De, dihexyl aluminum methoxide, hexyl al
Minium dimethoxide, dimethyl aluminum ethoxy
, Methyl aluminum diethoxide, diethyl aluminum
Aluminum ethoxide, ethyl aluminum diethoxide,
Diisobutyl aluminum ethoxide, isobutyl al
Alkyl aluminum alcohol such as minium diethoxide
Examples include quid.

The component (C) can be used in a wide range such as 1 to 10,000 mol per 1 mol of titanium atom of the component (A), but is preferably 1 to 1,000 mol, more preferably 1 to 500 mol. Used in the molar range.

In the present invention, a catalyst comprising a combination of (1), (A) component, (B) component and (C) component may be used as the polymerization catalyst, or (2), (A).
A reaction product obtained by previously contacting the component, the component (B) and the component (C) may be used.

Regarding the amount of each catalyst component used in the above method (1), the component (A) is 0.0001 to 5 mmol / liter, preferably 0.001 to 1 mmol / liter, and the component (B) is 0.1. 0001 to 5 mmol / liter, preferably 0.001 to 1 mmol / liter, and the component (C) is in the range of 0.01 to 500 mmol / liter, preferably 0.05 to 100 mmol / liter in terms of Al atom. And the component (B) component / (A) component molar ratio is 0.01 to 100, preferably 0.5 to 10 and the component (C) component / (A) component molar ratio is 0.1 to 2000, preferably 5 to It is desirable to use each component so that it is in the range of 1000.

On the other hand, in the method (2), the components (A), (B) and (C) are brought into contact with each other in an inert solvent in an inert gas atmosphere.
The component (A) is 0.01 to 100 mmol / liter,
It is preferable to use each component so that the component (B) is in the range of 0.01 to 100 mmol / liter and the component (C) is in the range of 0.1 to 1000 mmol / liter in terms of Al atom.

As a method for supplying each catalyst component to the polymerization tank, there are no particular conditions to be restricted except that the catalyst components are supplied in an inert gas such as nitrogen or argon in a water-free state. The polymerization in the present invention is 0 to 200 ° C, preferably 20 ° C to 10 ° C.
The temperature and the pressure at 0 ° C. are 0 to 100 kg / cm ² , preferably 0 to 50 kg / cm ² , and the polymerization method may be either batch type or continuous type.

In the polymerization by the solution method using the catalyst system of the present invention, the solution is generally selected from hexane, cyclohexane, heptane, kerosene components, hydrocarbon solvents such as toluene and the like.

The α-olefin used in the present invention is an α-olefin having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms. Examples thereof include propylene, butene-1, 4-methylpentene-1, hexene-1, octene-1, vinylcyclohexane and the like. It is also possible to add a chain transfer agent such as hydrogen to adjust the molecular weight of the polymer.

[0031]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. The properties of the polymers in the examples were measured by the following methods. (1) The α-olefin content was measured with ethylene and α using an infrared spectrophotometer (manufactured by JASCO Corporation) JASCO-302.
-Determined by characteristic absorption of olefin. (2) The intrinsic viscosity [η] is measured using an Ubbelohde viscometer,
It was measured in a tetralin solution at 135 ° C.

[0032]

[0033]

Example 1 (1) Synthesis of Titanium Amide Compound After replacing a 100 ml flask equipped with a stirrer, a dropping funnel and a thermometer with argon, 2.00 g of N, N-dimethylanilinoether and tetrakisdimethylamide were used. 1.97 g of titanium and 30 ml of toluene were charged. 80
After stirring at ℃ for 1 hour, after reacting at room temperature for 5 hours,
The solvent was removed by vacuum drying to obtain the product. Subsequently, a 1 L flask equipped with a stirrer and a thermometer was purged with argon, and the obtained product was transferred into toluene 300 m.
1 was added and cooled to -78 ° C. After replacing another 200 ml flask with argon, titanium titanium tetrachloride 0.9
6 ml and 50 ml of toluene were charged and cooled to -78 ° C. This titanium titanium tetrachloride toluene solution was transferred to the solution of the above 1 L flask with a canister and stirred overnight,
The temperature was gradually raised to room temperature. The supernatant was removed, and the precipitate was washed with 60 ml of toluene and dried under reduced pressure to obtain 2.1 g of a titanium amide compound ( A-1 ) represented by the composition formula [O (C ₁₄ H ₁₄ N ₂ )] TiCl _2. Obtained. After replacing a 100 ml flask equipped with a stirrer and a thermometer with argon, 0.12 g of the titanium amide compound ( A-1 ) and 10 ml of toluene were charged, and the mixture was cooled to -78 ° C. Next, a solution of benzyl Grignard reagent in diethyl ether 10.84
ml (0.84 mmol) was added. The reaction was carried out at −78 ° C. for 15 minutes, and then at room temperature for 30 minutes. After removing the generated solid, the solvent was removed by drying under reduced pressure, and the composition formula [O (C ₁₄ H ₁₄ N ₂ )] Ti [CH ₂ (C ₆ H
₅ )] The titanium amide compound represented by ₂ ( A-2 ) 0.
13 g were obtained.

(2) Polymerization of ethylene and α-olefin An autoclave with an internal volume of 400 ml equipped with a stirrer was vacuum dried and replaced with argon, and then toluene 92 was used as a solvent.
20 ml of butene-1 as an α-olefin was charged and the reactor was heated to 60 ° C. After the temperature was raised, ethylene pressure was adjusted to 6 kg / cm ² and hydrogen pressure was adjusted to 1 kg / cm ² for feeding, and after the system was stabilized, triisobutylaluminum (TIBA) 0. 5 mmol was added, and subsequently, the catalyst component ( A-2 ) 0.01 mmo prepared in (1) above.
l, and then (Ph ₃ C) [B (C ₆ F ₅ ) ₄ ].
0.02 mmol was added. Polymerization was performed for 1 hour while controlling the temperature at 60 ° C. to obtain a copolymer. The results are shown in Table 1. The degree of methyl branching of the obtained copolymer is high,
Moreover, the intrinsic viscosity was also high.

Example 2 In the ethylene-α-olefin copolymerization in Example 1 , 0.5 mmol of trihexylaluminum (THA) manufactured by Tosoh Akzo Co. was used as an organoaluminum compound.
Polymerization was performed in the same manner as in Example 1 except that was used. The results are shown in Table 1. The copolymer obtained in the same manner as in Example 1 had a high degree of methyl branching and a high intrinsic viscosity.

Example 3 ( A-1 ) 0.01 mm as a titanium amide compound in the ethylene-α-olefin copolymerization in Example 1 .
Polymerization was performed in the same manner as in Example 1 except that ol was used. The results are shown in Table 1. The copolymers obtained in the same manner as in Examples 1 and 2 had a high degree of methyl branching and a high intrinsic viscosity.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that 0.7 μmol of biscyclopentadienyl zirconium dichloride was used instead of the titanium amide compound in the ethylene-α-olefin copolymerization. The results are shown in Table 1. Unlike the previous examples, the degree of methyl branching of the copolymer is low, ie α
-Low olefin content and low intrinsic viscosity, i.e. low molecular weight.

[0039]

[Table 1]

[0040]

INDUSTRIAL APPLICABILITY With the catalyst system of the present invention, it is possible to efficiently produce a high molecular weight ethylene-α-olefin copolymer having a high α-olefin content in the copolymerization of ethylene and α-olefin. Become.

[Brief description of drawings]

FIG. 1 is a flow chart diagram to assist in understanding the present invention. This flowchart is a representative example of the embodiment of the present invention, and the present invention is not limited to this.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akio Imai 1-5 Anezaki Kaigan, Ichihara City, Chiba Sumitomo Chemical Co., Ltd. (56) Reference JP-A-6-216010 (JP, A) JP-A-2- 77412 (JP, A) JP 8-157533 (JP, A) JP 5-331236 (JP, A) JP 4-285607 (JP, A) JP 7-18019 (JP, A) JP-A-7-316217 (JP, A) International publication 94/029356 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08F 4/64-4/658 CA (STN)

Claims (3)

(57) [Claims] 1. A titanium amide compound (A) represented by the following general formula [I], a compound (B) which reacts with a transition metal compound to form a stable anion, and an organoaluminum compound (C).
An olefin polymerization catalyst comprising: (In the formula, R ^{1 to} R ⁴ represent a hydrocarbon group having 1 to 20 carbon atoms.
However, they may be the same or different. X is an oxygen atom
It R ⁵ and R ⁶ are hydrocarbon groups having 1 to 20 carbon atoms or halo
Represents a gen atom. ) 2. R ⁵ and R ⁶ have an aromatic ring and have 1 to 2 carbon atoms.
The olefin polymerization catalyst according to claim 1, which has 0 hydrocarbon group or a halogen atom . 3. A method for producing an ethylene-α-olefin copolymer, which comprises polymerizing ethylene and an α-olefin using the olefin polymerization catalyst according to claim 1 or 2.