JPH0687937A - Production of styrenic block copolymer - Google Patents

Abstract

PURPOSE:To obtain a styrenic block copolymer having excellent heat-resistance and syndiotacticity and useful for molded article, etc., in high efficiency by polymerizing a styrene (derivative) using a specific catalyst and further polymerizing an olefin. CONSTITUTION:The copolymer is produced by polymerizing an olefin such as ethylene after polymerizing a styrene (derivative) using a catalyst composed of (A) a transition metal compound of formula (Cp is cyclopentadienyl, indenyl or fluorenyl; A<1> to A<3> are halogen, H, 1-10C alkyl, alkoxy, 6-20C aryl, amide, etc.; n is 1-3; M is group 4-6 transition metal of the periodic table) [e.g. (cyclopentadienyl) (bistrimethylsilylamide) titanium dichloride] and (B) a cocatalyst such as aluminoxane.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a styrene block copolymer. Specifically, it relates to a method for producing a block copolymer of a styrene polymer having a syndiotactic structure and an olefin.

[0002]

2. Description of the Related Art Syndiotactic polystyrene is expected to be used because it has higher heat resistance than conventional atactic and isotactic polystyrene.
JP-A-62-104818 and JP-A-62-187.
No. 708, JP-A-2-102206 and the like describe that syndiotactic polystyrene can be produced using a catalyst containing a titanium compound and an aluminoxane as main components. Japanese Patent Laid-Open No. 63-172707 describes that syndiotactic polystyrene can be produced using a catalyst composed of at least one titanium compound having a Ti—N bond and an aluminoxane.
However, transition metal compounds having one cyclopentadienyl derivative ligand and at least one amide group ligand as used in the present invention are not known. On the other hand, a styrene-olefin block copolymer capable of improving the physical properties of such syndiotactic polystyrene is disclosed in JP-A-4-130114.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
No. 114 discloses that a styrene-based block copolymer having relatively excellent physical properties can be produced by block-copolymerizing a styrene-based derivative and an olefin using a known transition metal compound. Copolymerization using a known transition metal compound has a problem that the polymerization activity is insufficient.

[0004]

Means for Solving the Problems The inventors of the present invention have diligently studied a method for solving the above problems and efficiently producing a styrene block copolymer, and as a result, by using a specific novel transition metal compound, They have found that a styrene block copolymer can be efficiently produced, and have completed the present invention. That is, the present invention provides a method for producing a styrene-based block copolymer by polymerizing styrene and / or a styrene-based derivative, and then further polymerizing an olefin, wherein the compound represented by the general formula CpA ¹ A ² A ³ _n M (where: Cp represents a cyclopentadienyl group, an indenyl group, a fluorenyl group or derivatives 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 used, and a catalyst comprising a transition metal compound and a co-catalyst is used, which is a method for producing a styrene block copolymer. The above general formula CpA
^{In 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 A 3-methylindenyl group,
Examples thereof include a 4,5,6,7-tetrahydroindenyl group, a fluorenyl group, a 1-methylfluorenyl group, a 2,7-di-t-butylfluorenyl group and an octahydrofluorenyl group.

A ¹ , A ² , and A ³ are a halogen atom, a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group,
An aryl group, an alkylaryl group, an arylalkyl group or an amide group having 6 to 20 carbon atoms, A ¹ ,
At least one of A ² and A ³ is an amide group. The halogen atom is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, preferably a chlorine atom. 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,
Examples thereof include a benzyl group and a phenoxy group.
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. Diphenylsilylamide group,
Examples thereof include 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.

Preferable examples of the 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 characteristics of the transition metal compound of the present invention are as follows:
It has two cyclopentadienyl derivative ligands and at least one amide group ligand. These compounds can be obtained by reacting, for example, 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 an olefin polymerization catalyst 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. As such a cocatalyst, a known aluminoxane can be preferably used, but a known cocatalyst used in combination with a so-called metallocene compound, for example, Tokukaihei 1
No. 5,501,950, Japanese Patent Publication No. 1-502036, Japanese Unexamined Patent Publication No. 3-179006, and other compounds capable of stabilizing a transition metal cation, and Japanese Unexamined Patent Publication No. 3-179005. It is also possible to use compounds which exhibit Lewis acidity as described. As the aluminoxane, the following general formula

[0008]

[Chemical 1](Here, R represents a hydrocarbon group having 1 to 10 carbon atoms, and n is
It is 2 or more. ) Is a compound represented by
A methylaluminoxane that is a chill group, where n is 5 or more,
Preferably, 10 or more are used. Aluminoxa mentioned above
Some alkyl aluminum compounds are mixed in
It doesn't matter. In addition, in addition to this, Japanese Patent Laid-Open No. 2-24
701, JP-A-3-103407, etc.
Alumino with two or more types of alkyl groups listed
Described in Xanthan and JP-A-63-198691.
Aluminoxane in the form of particles, JP-A-2-167
No. 302, JP-A-2-167305, etc.
Contact the listed aluminoxane with water or active hydrogen compounds.
Aluminum oxy compounds etc. obtained by touching are also suitable
Can be used for. In addition, the aluminoxane
In addition, it is described in JP-A-3-197514.
Tetraalkyldialuminoxane should also be preferably used
You can With respect to the above transition metal compound in the present invention
The usage ratio of aluminoxane is 1 to 100,000
The amount is usually 10 to 10000 mol times. In the present invention
The transition metal compound and / or co-catalyst
Also SiO ₂, Al₂O₃, MgCl₂Ziegler
Even if it is used by supporting it on a known carrier that supports a -type catalyst.
Good. In addition, the transition metal compound / promoter in the present invention
The catalyst consisting of
It can be used in the field. By doing so
Made of olefin polymer using less aluminoxane
It is also possible to build.

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 the polymerization conditions used in the method of the present invention, and a solvent polymerization method using an inert hydrocarbon medium or a bulk polymerization method substantially free of an inert hydrocarbon medium is also used. The polymerization temperature for polymerizing styrene or its derivative is -100 to 20.
0 ° C., preferably −50 to 100 ° C. As polymerization conditions for polymerizing an olefin, a polymerization temperature is −100 to 20.
It is general to carry out at 0 ° C. and a polymerization pressure of atmospheric pressure to 100 kg / cm ² . The pressure is preferably −50 to 100 ° C. and atmospheric pressure to 50 kg / cm ² . 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. Examples of the styrene derivative used as a monomer in the present invention include styrene, o-methylstyrene, p-methylstyrene, o, p.
-Dimethylstyrene, o-chlorostyrene, p-chlorostyrene, α-methylstyrene and the like can be mentioned. Further, as the olefin used as a comonomer, ethylene, propylene, 1-butene, 4-methyl-
Examples thereof include 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and other olefins having about 2 to 25 carbon atoms, and ethylene is particularly preferable. preferable.
The polymerization ratio of the styrene or its derivative and the olefin of the present invention is determined by the physical properties of the target block copolymer, but usually 0.01 to 100 parts by weight of the olefin is generally added to 1 part by weight of the styrene or its derivative. Target.

[0011]

[(Cyclopentadienyl) (bistrimethylsilylamido) titanium dichloride]

3.0 g of cyclopentadienyl titanium trichloride was dissolved in 100 cm ³ of diethyl ether in a 300 cm ³ four-necked flask that had been sufficiently replaced with nitrogen. 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, C
DCl ₃ solution) (ppm) 6.66 (s, 5H), 0.41 (s, 18H) polymerization thoroughly purged with nitrogen 200 cm ³ of toluene 30 cm ³ glass flask, synthesized above (cyclopentadienyl) ( 5 mg of (bistrimethylsilylamido) titanium dichloride and 0.1 g of methylaluminoxane manufactured by Tosoh Akzo Co. were charged, 20 cm ³ of styrene was subsequently added, and styrene was prepolymerized for 3 minutes at an internal temperature of 20 ° C. Then, ethylene was introduced into the system and polymerization was carried out at 40 ° C. for 30 minutes. After the polymerization was stopped by adding a small amount of methanol to the system, the polymer produced was precipitated by introducing the polymerization slurry into a large amount of methanol / hydrochloric acid. 9.1g by drying the obtained polymer
A styrene-ethylene copolymer of was obtained. Of this polymer
^The styrene content measured by ¹ H-NMR spectrum was 35.4 mol%. As a result of the infrared absorption spectrum of the produced polymer as shown in FIG.
Styrene similar to that described in Japanese Patent No. 114
It was found to be an ethylene block copolymer.

Comparative Example 1 Styrene was polymerized in the same manner as in Example 2 except that 5 mg of cyclopentadienyltitanium trichloride was used as the transition metal compound. The obtained styrene-ethylene block copolymer was 1.2 g.

[0014]

The syndiotactic styrene polymer can be efficiently produced by carrying out the method of the present invention,
It is extremely valuable industrially.

[Brief description of drawings]

FIG. 1 shows an IR absorption spectrum of a styrene-ethylene block copolymer obtained in Example 1 of the present application.

Claims (2)

[Claims] ^1. A method for producing a styrenic block copolymer by polymerizing styrene and / or a styrene derivative and then further polymerizing an olefin, wherein a compound represented by the general formula CpA ¹ A ² A ³ _n M (where CpA ¹ A ² A ³ _n M 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 transition metal compound represented by the formula (1) and a catalyst comprising a co-catalyst are used to produce a styrene block copolymer. 2. The method for producing a styrene block copolymer according to claim 1, wherein the cocatalyst is aluminoxane.