JP2783527B2 - Catalyst composition and method for producing highly syndiotactic polystyrene or arylethylene polymer using the catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improved catalyst composition for producing highly syndiotactic polystyrene and the like. In particular, the present invention relates to an improved catalyst composition for producing polystyrene and the like which provides high activity and high syndiotacticity and is low in cost, and a method for producing polystyrene and the like using the same.

[0002]

BACKGROUND OF THE INVENTION Peroxides are the most commonly used catalysts in the production of polystyrene and generate free radicals to initiate the polymerization reaction. Polystyrene produced from the peroxide catalyzed process is atactic polystyrene (ap
s), which by definition does not have any stereoregularity. Atactic polystyrene, which has been widely used in numerous commercial applications for more than half a century, is an amorphous polymer. This amorphous physical property of atactic polystyrene has limited its applicability. This atactic polystyrene is mainly marketed as a relatively low value-added polymer,
This typically cannot be used in engineering plastic applications.

On the other hand, isotactic polystyrene (i
ps) from early 1955 Gee Natta
(G. Natta) using so-called Ziegler-Natta catalysts. This isotactic polystyrene is a highly crystalline polymer with a very high melting point (2
40 ° C.). These properties make isotactic polystyrene a suitable polymer for many engineering plastic applications. However, isotactic polystyrene has the disadvantage of having an undesirably low crystallization rate, which makes fabrication difficult. Unless this problem is overcome, isotactic polystyrene does not appear to have very high commercial potential.

[0004] Compared to atactic and isotactic polystyrene, syndiotactic polystyrene has emerged relatively recently. There was no syndiotactic polystyrene until 1986, when syndiotactic polystyrene was first developed by Ishihara using a metallocene catalyst composition. Typically, the production of this syndiotactic polystyrene involves:
Transition metal titanium complex and methylaluminoxane (methy
A catalyst composition containing aluminoxane) (or "MAO") is required. Syndiotactic polystyrene can be produced by the synergistic action of the titanium complex and methylaluminoxane. The description of the method for producing syndiotactic polystyrene is described, for example, in EP-A-210,615 and cyclopentadienyl trichloro using a catalyst composition containing tetra (ethoxy) titanium and methylaluminoxane for producing syndiotactic polystyrene. WO 8,810,275 reports that high syndiotactic polystyrene was produced using a catalyst composition containing titanium and methylaluminoxane.

[0005] US Patent Nos. 4,774,301 and 4,808,
No. 680 discloses the use of a catalyst composition containing a transition metal zirconium complex and methylaluminoxane to produce syndiotactic polystyrene. Compared to a catalyst composition using a titanium complex and methylaluminoxane, the catalyst composition containing this zirconium complex exhibits relatively low activity, and the polystyrene so produced has a relatively low molecular weight and a relatively low The geekiness was indicated.

[0006] All of these catalyst compositions for producing syndiotactic polystyrene contain a Group IV transition metal compound and methylaluminoxane to provide activation. It should be noted that a very high excess of methylaluminoxane is required to provide the desired activation catalyst. Due to the high cost of methylaluminoxane, these methods are very limited for commercial applications. Thus, it is highly desirable to develop metallocene-based catalyst compositions that can minimize or even eliminate the amount of methylaluminoxane required. EP-A-505,890 and WO 930,367 describe catalyst compositions containing cyclopentadienyltrialkyltitanium as catalyst for the production of high syndiotactic polystyrene, a non-coordinating Lewis acid as cocatalyst and triisobutylaluminum as scavenger. Is disclosed. However, this catalyst composition has a relatively low activity.

[0007] Within the group of titanium complexes, especially titanocenes, the catalytic activity for producing polystyrene is 2
Higher for titanocenes containing one cyclopentadienyl ligand than for titanocenes containing one cyclopentadienyl ligand. The catalytic activity of titanocene containing one cyclopentadienyl ligand is also higher than titanium complexes that do not contain cyclopentadienyl ligand (but not titanocene by definition). This relative relationship is
It is disclosed in EP-A-210,615. The catalytic activity of titanium complexes without cyclopentadienyl ligand is substantially lower than titanocene containing one cyclopentadienyl ligand, but has the advantage of being substantially less expensive. I have. Therefore, from economic considerations, we have developed a cocatalyst composition that can substantially increase the activity of the cheapest titanium complex, that is, a titanium complex that does not contain a cyclopentadienyl ligand, and have excellent catalytic activity. It is highly desirable to reduce the overall cost of the metallocene catalyst composition while providing

[0008]

SUMMARY OF THE INVENTION It is a primary object of the present invention to provide an improved catalyst composition for producing highly syndiotactic polystyrene. Furthermore, a main object of the present invention is to enable the use of more economical ingredients,
An improved catalyst composition for producing polystyrene that minimizes expensive components such as methylaluminoxane and substantially reduces the cost of the catalyst composition while providing high catalytic activity and high syndiotacticity. To provide.

[0009]

SUMMARY OF THE INVENTION The catalyst composition disclosed in the present invention comprises the following three main components.

(A) Formula: TiR ′ ₁ R ′ ₂ R ′ ₃ R ′ ₄ (where R ′ ₁ , R ′ ₂ , R ′ ₃ and R ′ ₄ are independently
A titanium complex represented by an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or all halogen atoms);

[0011]

Embedded image

(Wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently an alkyl group, an aryl group, a silyl group, a germanyl group (—GeH ₃ ), a stannyl group (—SnH ₃ ), a hydrogen atom Or a halogen atom, R is an alkyl group, an aryl group, a hydrogen atom or a halogen atom, and X is one of Group IVA elements of silicon (Si), germanium (Ge) or tin (Sn). A cyclopentadienyl complex of silicon (Si), germanium (Ge) or tin (Sn) represented; (c) an activated transition metal cocatalyst; the activated transition metal cocatalyst is methylaluminoxane or a non-coordinating Lewis acid (Lewis acids are electron donors) and trialkylaluminums such as triethylaluminum or triisobutylaluminum.

[0013] In the improved catalyst composition disclosed in the present invention, the titanium complex is selected from the titanium complex described in the above (a).
Instead of the (IV) complex, a Ti (III) complex may be used. In this embodiment, the titanium complex is rather TiR ' ₁
R _'2 R' ₃ (wherein, R _'1, R' ₂ and R _'3 are each independently alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a halogen atom) by the formula Is represented.

One of the advantages of the catalyst composition disclosed in the present invention is that it is a very inexpensive chemical, namely Ti
R ′ ₁ R ′ ₂ R ′ ₃ R ′ ₄ or TiR ′ ₁ R ′ ₂ R ′ ₃ is
The aim is to have high activity in producing high syndiotactic polystyrene from styrene or other arylethylene monomers. TiR ' ₁ R' ₂ R ' ₃
R _'4 or _{TiR' 1 R '2 R'} 3 was primarily considered to have only low activity in the production of syndiotactic polystyrene. According to the present invention, the cost of the catalyst can be reduced by almost an order of magnitude compared to conventional catalysts that provide similar activity and syndiotacticity.

Another advantage of the catalyst composition disclosed in the present invention is that the catalyst composition is not sensitive to degradation by exposure to air and moisture. Most catalysts for the production of syndiotactic polystyrene contain cyclopentadienyl-coordinated titanium, such as cyclopentadienyltrichlorotitanium and cyclopentadienyltrimethoxytitanium, which are sensitive to air and moisture. Is known to be sensitive. Thus, the present invention discloses an improved catalyst composition for producing highly syndiotactic polystyrene, which exhibits excellent activity and storage stability and can be produced at substantially reduced cost.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved catalyst composition for producing high syndiotactic polystyrene and a method for the catalytic production of polystyrene with the improved catalyst composition. The improved catalyst composition disclosed in the present invention allows for the use of very economical components, whereby high activity and high syndiotacticity comparable to the best commercial products at substantially higher cost And can substantially reduce the cost of the catalyst composition.

The catalyst composition disclosed in the present invention comprises the following three main components as described above.

(A) Formula: TiR ′ ₁ R ′ ₂ R ′ ₃ R ′ ₄ (where R ′ ₁ , R ′ ₂ , R ′ ₃ and R ′ ₄ are independently
A titanium (IV) complex represented by an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a halogen atom).

Examples of the titanium (IV) complex include triisopropoxychlorotitanium, tetraethoxytitanium and the like.

[0020] In the improved catalyst composition disclosed in the present invention, the titanium complex is selected from the group consisting of Ti as described in (a) above.
Instead of the (IV) complex, a Ti (III) complex may be used. In this embodiment, the titanium complex is rather TiR ' ₁
R _'2 R' ₃ (wherein, R _'1, R' ₂ and R _'3 are each independently alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a halogen atom) by the formula Is represented.

Equation (b):

[0022]

Embedded image

Wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently an alkyl group, an aryl group, a silyl group, a germanyl group, a stannyl group or a halogen atom, and R is an alkyl group, an aryl group , A hydrogen atom or a halogen atom, and X is one of the Group IVA elements of silicon (Si), germanium (Ge) or tin (Sn)). (Sn) cyclopentadienyl complex.

Examples of the cyclopentadienyl complex include tetramethylcyclopentadienyltrimethylsilicon, tetramethylcyclopentadienyl-tri- (n
-Butyl) tin and the like.

(C) Activated transition metal cocatalyst; this activated transition metal cocatalyst may be a methylaluminoxane or a non-coordinating Lewis acid (the Lewis acid is an electron pair donor) and a triethylaluminum or triisobutylaluminum. A mixture with a trialkylaluminum.

Non-coordinating Lewis acids include, for example, N, N
-Dimethylanilinium tetrakis (pentafluorophenyl) borate, triphenylcarbenylmtetrakis (pentafluorophenyl) borate, ferrocerium tetrakis (pentafluorophenyl) borate, trialkylammonium tetrakis (pentafluorophenyl) borate, dialkylferrocerium tetrakis (Pentafluorophenyl) borate and the like, and N, N-dimethylaniliumtetrakis (pentafluorophenyl) borate is particularly preferred.

As the trialkylaluminum,
For example, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri (n-butyl) aluminum, tri (n-propyl) aluminum, triisopropylaluminum and the like can be mentioned, with triisobutylaluminum being particularly preferred.

Preferred examples of the activated transition metal cocatalyst include N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate as the non-coordinating Lewis acid and triisobutylaluminum as the trialkylaluminum. .

The production method of the present invention comprises: (a) a step of producing a catalyst composition containing the above three main components; and (b) the catalyst composition and styrene or other arylethylene monomer in a reactor. Charging and initiating a polymerization reaction,
And (c) stopping the polymerization reaction to obtain a polymerization product.

In a preferred embodiment of the process disclosed in the present invention, nitrogen is first introduced into a polystyrene reactor maintained at 50 ° C. to purge air. 110m to this reactor
L of added methylaluminoxane toluene and an appropriate amount, followed cyclopentadienyl trimethyl silicon complex and titanium (IV) complexes _{TiR '1 R' 2 R '} 3 R' 4
Is added. The reaction mixture is stirred for 5 minutes, then the styrene monomer is added to initiate the polymerization reaction. About 1
After a time, when the polymerization reaction is complete, the reaction mixture containing the reaction product is quenched with methanol or isopropanol and the syndiotactic polystyrene (sps) is isolated by precipitation. The syndiotactic polystyrene thus obtained is extracted with methyl ethyl ketone (MEK) to remove the amorphous polystyrene.
The insoluble portion is commonly called MIP (MEK insoluble portion), which is an indicator of the ratio between syndiotactic polystyrene (sps) and atactic polystyrene (aps). As the value of aps / sps increases, the proportion of syndiotactic polystyrene decreases.

The present invention will be further described with reference to the following examples. Description of the examples, including preferred embodiments of the invention,
It should be noted that they are set forth herein for purposes of illustration and description, and are not meant to be exhaustive or to limit the invention to the precise forms disclosed. .

Example 1 450 mL Fischer equipped with an electrically driven stirrer
To a Porter (Fisher-Porter) bottle, 100 mL of toluene was added. The reaction bottle is heated until its internal temperature reaches 70 ° C. and then methylaluminoxane (6.
(Containing 6 mmol Al). Then 0.75 mL of 1.6 × 10 ^-2 M triisopropoxychlorotitanium [ClTi (O-iPr) ₃ ] in toluene and 1.6 × 10 ^-2 M tetramethylcyclopentadienyltrimethylsilicon in toluene 0.75 mL was added. Finally, 20 mL of styrene monomer was added to start the polymerization reaction. After the reaction was continued at 70 ° C. for 1 hour, the reaction was stopped by adding methanol. White syndiotactic polystyrene particles precipitated from the reaction mixture. After filtration and drying (at 80 ° C. and under reduced pressure),
1.35 g of syndiotactic polystyrene were obtained.
This is 2.0 × 10 ⁴ g sps / g Ti · hr [grams of sps generated by 1 g of Ti complex per hour]
Showed the catalytic activity of The syndiotacticity of the thus produced syndiotactic polystyrene is NM
Analyzed to be 98% using R. aps / sps
A Soxhlet extraction operation was also performed using methyl ethyl ketone to determine the ratio. MEK insoluble part (MIP)
Was determined to be 92%.

Comparative Example 1 The method in Comparative Example 1 was the same as that in Example 1 except that the reaction mixture did not contain tetramethylcyclopentadienyltrimethylsilicon. In this comparative example, the catalyst composition contained 6.6 mmol aluminoxane (measured on the basis of Al content) and 1.6 × 10 ⁻² M [ClTi (O-iPr) ₃ ] in toluene.
Only 0.75 mL was contained. After the steps of polymerization reaction, precipitation with methanol, filtration and drying, 0.4
2 g sps, which is 8.5 × 10 ² g sps /
g Ti · hr showed catalytic activity.

Example 2 450 mL Fisher equipped with an electric drive stirrer
100 mL of toluene was added to the porter bottle.
The reaction bottle is heated until its internal temperature reaches 70 ° C., then methylaluminoxane (6.6 mmol of A
l). Then, 1.
6 × 10 ^-2 M triisopropoxychlorotitanium [ClT
i (O-iPr) ₃ ] and 0.75 mL of 1.6 × 10 ^-2 M tetramethylcyclopentadienyl- in toluene
0.75 mL of tri (n-butyl) tin was added. Finally, 20 mL of styrene monomer was added to start the polymerization reaction. After the reaction was continued at 70 ° C. for 1 hour, the reaction was stopped by adding methanol. White syndiotactic polystyrene particles precipitated from the reaction mixture. After filtration and drying (at 80 ° C. and under reduced pressure), 3.42 g of syndiotactic polystyrene were obtained. This is 6.0x
The catalyst activity at 10 ³ g sps / g Ti · h was shown.

Example 3 450 mL Fisher equipped with an electric drive stirrer
100 mL of toluene was added to the porter bottle.
The reaction bottle is heated until its internal temperature reaches 70 ° C., and then 1.21 mL (4.8 × 10 ⁻³ mol) of triisobutylaluminum (trialkylaluminum)
And a mixture containing 0.012 g (14 × 10 ⁻⁵ mol) of N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate (a non-coordinating Lewis acid) was added. This was followed by 1.6 × 10 ^-2 M in toluene.
Tetraethoxy titanium [Ti (OEt) ₄ ] 0.75 m
0.75 mL of L × 1.6 × 10 ⁻² M tetramethylcyclopentadienyltrimethylsilicon in toluene was added. Finally, 20 mL of styrene monomer was added to start the polymerization reaction. After the reaction was continued at 70 ° C. for 1 hour, the reaction was stopped by adding methanol. White syndiotactic polystyrene particles precipitated from the reaction mixture. After filtration and drying (at 80 ° C. and under reduced pressure)
7.24 g of syndiotactic polystyrene were obtained.
This showed a catalytic activity of 1.3 × 10 ⁴ g sps / g Ti · hr.

The foregoing description of a preferred embodiment of the present invention has been presented for purposes of illustration and description. Obvious modifications or variations are possible in light of the above teachings. It is intended to provide a best illustration of the principles of the invention and its practical application, so that those skilled in the art can utilize the invention in various aspects and modifications to suit the particular application intended. In order to do so, embodiments were selected and described. All such modifications and variations are within the scope of the present invention, as determined by the following claims, as interpreted by the breadth given fairly, legally and equitably.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-187708 (JP, A) JP-A-4-296306 (JP, A) JP-A-6-263815 (JP, A) JP-A-3- 119006 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C08F 4/60-4/70

Claims (18)

(57) [Claims] 1. A (a) _{formula: TiR '1 R' 2 R} '3 R' 4 or _{TiR '1 R' 2 R '} 3 ( _{wherein, R' 1 R '2 R} ' 3 and R _'4 of Each of which is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a halogen atom), which does not have a cyclopentadienyl ligand;
I) a complex; (b) a formula: (Wherein, R ₁ , R ₂ , R ₃ and R ₄ are each independently an alkyl group, an aryl group, a silyl group, a germanyl group, a stannyl group or a halogen atom, and R is an alkyl group, an aryl group, A hydrogen atom or a halogen atom, and X is selected from the group consisting of group IVA elements of silicon, germanium and tin); cyclopentadienyl complex of silicon, germanium or tin; and (c) methylaluminoxane or A catalyst composition for the production of highly syndiotactic polystyrene or other arylethylene polymers, comprising an activated transition metal cocatalyst that is a mixture containing a non-coordinating Lewis acid and a trialkylaluminum. 2. The method according to claim 1, wherein the titanium complex is a titanium (IV) complex and has the formula TiR ′ ₁ R ′ ₂ R ′ ₃ R ′ ₄ (where R ′ ₁ ,
R _'2, R' each ₃ and R _'4 are independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, the catalyst composition according to claim 1, wherein represented by amino group or a halogen atom) . 3. The trialkylaluminum contained in the activated transition metal cocatalyst is trimethylaluminum, triethylaluminum, triisobutylaluminum, tri (n-butyl) aluminum, tri (n-aluminum).
The catalyst composition according to claim 1, wherein the catalyst composition is selected from the group consisting of propyl) aluminum and triisopropylaluminum. 4. The catalyst composition according to claim 1, wherein said trialkylaluminum is triisobutylaluminum. 5. The non-coordinating Lewis acid contained in the activated transition metal cocatalyst is N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate or triphenylcarbenium tetrakis (pentafluorophenyl) borate. The catalyst composition according to claim 1, wherein the catalyst composition is selected from the group consisting of and ferrocerium tetrakis (pentafluorophenyl) borate. 6. The non-coordinating Lewis acid contained in the activated transition metal cocatalyst is selected from the group consisting of trialkylammonium tetrakis (pentafluorophenyl) borate and dialkylferrocerium tetrakis (pentafluorophenyl) borate. The catalyst composition according to claim 1, wherein 7. The catalyst composition according to claim 1, wherein the non-coordinating Lewis acid contained in the activated transition metal cocatalyst is N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate. 8. The catalyst composition according to claim 1, wherein the non-coordinating Lewis acid contained in the activated transition metal cocatalyst is triphenylcarbenium tetrakis (pentafluorophenyl) borate. 9. The catalyst composition according to claim 1, wherein the non-coordinating Lewis acid contained in the activated transition metal cocatalyst is ferrocerium tetrakis (pentafluorophenyl) borate. 10. The catalyst composition according to claim 1, wherein the non-coordinating Lewis acid contained in the activated transition metal cocatalyst is a trialkylammonium tetrakis (pentafluorophenyl) borate. 11. The catalyst composition according to claim 1, wherein the non-coordinating Lewis acid contained in the activated transition metal cocatalyst is dialkylferrocerium tetrakis (pentafluorophenyl) borate. 12. The activated transition metal co-catalyst comprises N, N
Non-coordinating Lewis acid which is -dimethylanilinium tetrakis (pentafluorophenyl) borate and trimethylaluminum, triethylaluminum, triisobutylaluminum, tri (n-butyl) aluminum, tri (n-propyl) aluminum and triisopropylaluminum The catalyst composition according to claim 1, comprising a trialkylaluminum selected from the group. 13. An activated transition metal co-catalyst comprising N, N
The catalyst composition according to claim 1, comprising a non-coordinating Lewis acid which is -dimethylanilinium tetrakis (pentafluorophenyl) borate and a trialkylaluminum which is triisobutylaluminum. 14. The catalyst composition according to claim 1, wherein the cyclopentadienyl complex is tetramethylcyclopentadienyltrimethylsilicon. 15. The catalyst composition according to claim 1, wherein the cyclopentadienyl complex is tetramethylcyclopentadienyl-tri (n-butyl) tin. 16. The catalyst composition according to claim 1, wherein the titanium complex is triisopropoxychlorotitanium. 17. The catalyst composition according to claim 1, wherein said titanium complex is tetraethoxytitanium. 18. (a) (i) Formula TiR ′ ₁ R ′ ₂ R ′ ₃
R ′ ₄ or TiR ′ ₁ R ′ ₂ R ′ ₃ (wherein R ′ ₁ ,
Each of R ′ ₂ , R ′ ₃ and R ′ ₄ independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a halogen atom) Without titanium (I
V) or a titanium (III) complex; (ii) a formula: (Wherein, R ₁ , R ₂ , R ₃ and R ₄ are each independently an alkyl group, an aryl group, a silyl group, a germanyl group, a stannyl group or a halogen atom, and R is an alkyl group, an aryl group, A hydrogen atom or a halogen atom, and X is selected from the group consisting of silicon, germanium and tin Group IVA elements), cyclopentadienyl complex of silicon, germanium or tin; and (iii) methylaluminoxane or Producing a catalyst composition comprising an activated transition metal cocatalyst which is a mixture containing a non-coordinating Lewis acid and a trialkylaluminum; (b) reacting the catalyst composition and styrene or other arylethylene monomer in a reactor (C) stopping the polymerization reaction and removing the polymerization product. A method for producing a high syndiotactic polystyrene or arylethylene polymer in contact.