JP2711708B2 - Method for producing olefin polymer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an olefin polymer. More specifically, the present invention relates to a method for producing an olefin polymer in which a high stereospecific polymer is obtained in a high yield by polymerizing an olefin using a specific catalyst system.

[Prior art] An olefin polymerization catalyst comprising a solid titanium catalyst component containing titanium, magnesium and halogen as essential components and an organoaluminum compound catalyst component is used as a highly active polymerization catalyst or a highly stereoregular olefin polymerization catalyst. Well known as

[Problems to be Solved by the Invention] When such a catalyst is used to polymerize ethylene, a highly active polyethylene having an alkyl branch is produced,
It is also known that polymerization of an α-olefin represented by propylene and 1-butene produces a polyα-olefin having a steric defect even though it is a highly active and highly stereospecific polymerization catalyst. Particularly, in the polymerization of α-olefins, it is generally necessary to add various electron donors at the time of preparing a catalyst or at the time of polymerization in order to improve the yield of a highly stereoregular polymer. Such addition of an electron donor often gives the resulting polymer problems such as coloring and odor.

On the other hand, an object of the present invention is to provide a production method capable of obtaining a highly stereoregular polyolefin having extremely few steric defects in a high yield by polymerizing an olefin using a specific catalyst system.

[Means for Solving the Problems] The above object is achieved by polymerizing an olefin using a catalyst system shown below. That is, the catalyst system used is a) a solid component composed of δ-type titanium trichloride and (hereinafter abbreviated as component (a)), and b) a metallocene composed of a cyclopentadienyl ring, which is represented by the following general formula [I] Or [II]: (Cyclo-R) ₂ M (CH ₃ ) ₂ [I] [Wherein (Cyclo-R) represents a cyclopentadienyl group or a methylcyclopentadienyl group, and M represents titanium or zirconium. ] (Hereinafter, referred to as component (b)).

Here, the component (a) is described in JP-A-46-3717 and JP-A-47-34.
Modified TiCl ₃ (Solvay-type TiCl ₃ ) represented by JP-A-478, JP-A-49-59094, JP-A-55-753 and the like.
These TiCl ₃ -containing solids may be used as a mixture of two or more.

Specific examples of the cyclopentadienyl compound represented by the general formula [I] or [II] as the component (b) include the following compounds (Cp = cyclopentadienyl, Ind
= Indenyl, Me = methyl, Et = ethyl, Ph = phenyl).

Bis (cyclopentadienyl) dimethyl titanium Cp ₂ T
iMe ₂ bis (methylcyclopentadienyl) dimethyl titanium (MeCp) ₂ TiMe ₂ (μ-methylene) (μ-methyl) bis (cyclopentadienyl) (dimethylaluminum) titanium (Μ-methylene) (μ-methyl) bis (methylcyclopentadienyl) (dimethylaluminum) titanium These cyclopentadienyl compounds can be used alone or in combination of two or more.

The amount of the cyclopentadienyl compound represented by the general formula [I] or [II] is preferably in the range of 0.1 to 1000 in a molar ratio with respect to the TiCl ₃ -containing solid titanium as the component (a).

In the olefin has the general formula R-CH = CH ₂ [wherein homopolymerization or copolymerization using a catalyst system of the present invention, R is a hydrocarbon residue having 1 to 10 hydrogen atoms, or carbon atoms, the substituent May be included]. Specifically, for example, ethylene, propylene, 1-butene, 1-
There are olefins such as pentene, 1-hexene, 1-heptene, 1-octene and 4-methyl-1-pentene. Preferably, ethylene, propylene, 1-butene,
4-methyl-1-pentene. Particularly preferred are ethylene and propylene.

The operation method itself for polymerizing an olefin using the catalyst of the present invention is not particularly limited, and a known polymerization method is used. For example, a slurry polymerization method can be used. As a polymerization solvent in the case of slurry polymerization, hexane, heptane, pentane, cyclohexane, benzene,
A single or mixture of a saturated aliphatic or aromatic hydrocarbon such as toluene or a polymerized monomer is used. The polymerization temperature is selected from the range of −20 to 100 ° C., preferably 0 to 80 ° C., and the pressure is selected from the range of atmospheric pressure to 100 atm.

[Example] Example 1 (a) but component preparation dry hexane 120ml and under a nitrogen atmosphere of pure titanium tetrachloride 30ml of (modified TiCl _3), were introduced into a round-bottomed flask. The hexane-titanium tetrachloride solution was cooled to 0 ° C., and a solution consisting of 90 ml of hexane and 34.4 ml of diethylaluminum chloride was added over about 5 hours, taking care not to raise the temperature in the reactor. After the addition, stir for 15 minutes at a temperature of 0 ° C., then raise the temperature to 23 ° C. over 1 hour and add 65 minutes over a further 30 minutes.
C. and stirred at this temperature for 1 hour. The liquid phase and the solid were then separated by filtration, and the solid product was dried in hexane 10
Washed 5 times with 0 ml.

The obtained solid was suspended in 300 ml of dry hexane, and 48.5 ml of isoamyl ether was added thereto. 35 this suspension
Stirred at ° C. for 1 hour and the resulting treated solid was separated from the liquid phase.

This treated solid was suspended in 100 ml of hexane and 70 ml of titanium tetrachloride. The suspension was stirred at 65 ° C. for 2 hours. The liquid phase is then removed, the solid product obtained is washed four times with 100 ml of hexane at 25 ° C. and finally with 100 ml of hexane at 65 ° C.
Washed twice. Thereafter, the solid was dried under reduced pressure at room temperature to obtain modified TiCl ₃ (Solvay type TiCl ₃ ) as the component (a).

Preparation of Component (b) Bis (cyclopentadienyl) dimethyltitanium (Cp
Synthesis of ₂ TiMe ₂ ) The method of K. Clauss et al. [K. Clauss, H. Bestian, Justus Lieb
ig Ann. Chem., 654 , 8 (1962). ], Bis (cyclopentadienyl) dichlorotitanium (Cp ₂ TiCl ₂ ) was reacted with methyllithium (MeLi) to synthesize and isolate bis (cyclopentadienyl) dimethyltitanium (Cp ₂ TiMe ₂ ). . Synthesized and isolated Cp ₂ TiMe ₂ is unstable to heat and light, and in consideration of ease of use during polymerization, dilute the compound into a 0.25 mol / l solution of heptane. ,
It was stored in a dark place at -78 ° C under a nitrogen gas atmosphere.

Polymerization of propylene A 200 ml glass flask was used as a polymerization vessel.
The reaction vessel was previously placed under a nitrogen gas atmosphere, and 155 mg of the modified TiCl ₃ prepared above was introduced, and the total amount of heptane as a polymerization solvent (including the amount of the heptane solution of Cp ₂ TiMe ₂ added later was also included in the calculation) to 100 ml. I added it. Polymerization temperature 4
After stirring at 0 ° C. for 5 minutes, nitrogen gas was exhausted and propylene gas was introduced to saturate for 20 minutes. The polymerization pressure was 1 atm. Next, 8 ml of a heptane solution of Cp ₂ TiMe ₂ (0.25 mol / l)
The polymerization was started by adding. The polymerization was carried out for 15 minutes, and the polymerization was stopped by adding a hydrochloric acid-methanol solution to the polymerization system. The resulting polymer was thoroughly washed with methanol and dried under vacuum. The yield was 1.34 g.

Stereoregularity of formed polymer Stereoregularity of formed polymer (isotacticity)
Is a commonly used boiling heptane extraction method shown below and ¹³
It was evaluated by C NMR measurement.

The resulting polymer was extracted with boiling heptane for 6 hours, and the weight% of the insoluble portion was defined as an isotactic index (II). II of the polymer produced in this example
Was 99.2%. ^13C NMR measurements of the polymer produced and the insoluble part of boiling heptane were measured using JEOL JNH GX-500.
C. was performed. For the measurement, 1,2,4-trichlorobenzene / deuterated benzene (3/1 volume ratio) was used as a solvent, and hexamethyldisiloxane was used as an internal standard substance. From the ¹³ C NMR measurement results of both polymers, the mmmm (mesomesomesomeso) chain fraction of the side chain methyl carbon of propylene was calculated as J.Polym.Sc
Calculated according to the method described in i., Polym. Phys. Ed. 14 , 2083 (1976), the mmmm of the resulting polymer is 98.7
%, And the mmmm of the insoluble portion in boiling heptane was 99.5%.

Example 2 Synthesis of bis (methylcyclopentadienyl) dimethyltitanium [(MeCp ₂ TiMe ₂ ]] As in the case of Cp ₂ TiMe ₂ synthesized in Example 1, K. Clau
bis (methylcyclopentadienyl) by the method of SS et al.
Dichlorotitanium [(MeCp) ₂ TiCl ₂ ] was reacted with MeLi to synthesize and isolate bis (methylcyclopentadienyl) dimethyl titanium [(MeCp) ₂ TiMe ₂ ]. Also, as in Example 1, taking into account the chemical properties of (MeCp) ₂ TiMe ₂ and the ease of use during polymerization,
Diluted to a mol / l solution and stored similarly.

Polymerization of Propylene The heptane solution of Cp ₂ TiMe ₂ used in Example 1 (0.
The polymerization of propylene was carried out in the same manner as in Example 1 except that 8 ml of a (MeCp) ₂ TiMe ₂ heptane solution (0.25 mol / l) was used instead of 8 ml of (25 mol / l). The yield of the produced polymer was 1.57 g.

Stereoregularity of formed polymer Stereoregularity of formed polymer (isotacticity)
Was evaluated by the boiling heptane extraction method and ¹³ C NMR measurement in the same manner as in Example 1.

II of the produced polymer was 99.2%. The mmmm of the produced polymer and the propylene side chain methyl carbon in the insoluble portion of boiling heptane were 98.5% and 99.3%, respectively.

Example 3 (μ-methylene) (μ-methyl) bis (cyclopentadienyl) (dimethylaluminum) titanium [Cp ₂ TiC
Synthesis of H ₂ (Me) AlMe ₂ ) (FNTebbe, GWParshall, GSRe
ddy, J. Am. Chem. Soc., 11 , 3611 (1978). ], Bis (cyclopentadienyl) dimethyl titanium (Cp ₂ T
Reaction of iMe ₂ ) with trimethylaluminum (AlMe ₃ ) to synthesize (μ-methylene) (μ-methyl) bis (cyclopentadienyl) (dimethylaluminum) titanium [Cp ₂ TiCH ₂ (Me) AlMe ₂ ] did. This was stored as a 0.25 mol / l solution of heptane in a dark place at -78 ° C under a nitrogen gas atmosphere without isolation.

Polymerization of Propylene The heptane solution of Cp ₂ TiMe ₂ used in Example 1 (0.
Propylene was polymerized in the same manner as in Example 1 except that 8 ml of a Cp ₂ TiCH ₂ (Me) AlMe ₂ heptane solution (0.25 mol / l) was used instead of 8 ml of 25 mol / l). The yield of the produced polymer was 4.00 g.

Stereoregularity of formed polymer Stereoregularity of formed polymer (isotacticity)
Was evaluated by the boiling heptane extraction method and ¹³ C NMR measurement in the same manner as in Example 1.

The II of the resulting polymer was 98.2%. The mmmm of the polymer produced and the propylene side chain methyl carbon in the insoluble part of boiling heptane were 96.3% and 97.5%, respectively.

Example 4 Synthesis of (μ-methylene) (μ-methyl) bis (methylcyclopentadienyl) (dimethylaluminum) titanium [(MeCp) ₂ TiCH ₂ (Me) AlMe ₂ ] Cp ₂ TiCH synthesized in Example 3 ₂ Similarly to (Me) AlMe ₂ , bis (methylcyclopentadienyl) dimethyltitanium [(MeCp) ₂ TiMe ₂ ] was obtained by the method of FNTebbe et al.
By reaction with AlMe ₃ , (μ-methylene) (μ-methyl) bis (methylcyclopentadienyl) (dimethylaluminum) titanium [(MeCp) ₂ TiCH ₂ (Me) AlMe ₂ ] was synthesized. As in Example 3, this was carried out as a 0.25 mol / l solution of heptane without isolation under a nitrogen gas atmosphere at −7%.
Stored at 8 ° C in the dark.

Polymerization of Propylene The heptane solution of Cp ₂ TiMe ₂ used in Example 1 (0.
Propylene was polymerized in the same manner as in Example 1 except that 8 ml of (MeCp) ₂ TiCH ₂ (Me) AlMe ₂ was used in place of 8 ml of a heptane solution (0.25 mol / l) instead of 8 ml. Was. The yield of the produced polymer was 4.68 g.

Stereoregularity of formed polymer Stereoregularity of formed polymer (isotacticity)
Was evaluated by the boiling heptane extraction method and ¹³ C NMR measurement in the same manner as in Example 1.

II of the resulting polymer was 97.3%. The mmmm of the produced polymer and the propylene side chain methyl carbon in the insoluble portion of boiling heptane were 95.0% and 96.5%, respectively.

Comparative Example 1 Solid titanium catalyst (TiCl ₄ / n-BP / MgC) corresponding to component (a)
l under reduced pressure of anhydrous magnesium chloride prepared 10.5g (110.5mmol) of ₂ catalyst) was 3 hours drying at a temperature of 300 ° C.. Then, the dried magnesium chloride MgCl ₂ 7.9m was placed in an 80ml steel grinding ball containing 50g of steel balls of various diameters (4,6,8,12mm).
mol of di-n-butyl phthalate (n-BP) were added and co-ground for 24 hours at room temperature under a nitrogen atmosphere. The above ball has frequency
It was linked to an 8Hz vibration ball mill. The co-ground product was reacted with 120 ml of titanium tetrachloride (TiCl ₄ ) at 120 ° C. for 2 hours. The reaction was washed 10 times with 200 ml of toluene at 60 ° C. and dried at room temperature under reduced pressure. The obtained solid catalyst was found to contain 2.0% by weight of titanium by colorimetry.

Polymerization of propylene TiCl ₄ / n-BP / M prepared above as component (a) during polymerization
The same method as in Example 1 was used except that 8 ml of a heptane solution of triethylaluminum (0.25 mol / l) and 4 ml of a heptane solution of phenyltriethoxysilane (0.05 mol / l) were used as components of 50 mg of gCl ₂ catalyst (b). Propylene was polymerized. The yield of the produced polymer was 3.58 g.

Stereoregularity of formed polymer Stereoregularity of formed polymer (isotacticity)
Was evaluated by the boiling heptane extraction method and ¹³ C NMR measurement in the same manner as in Example 1.

II of the resulting polymer was 95.4%. The mmmm of the produced polymer and the propylene side chain methyl carbon in the insoluble part of boiling heptane were 89.4% and 93.1%, respectively.

Example 5 Polymerization of 1-butene A 200 ml glass flask was used as a polymerization vessel.
The reaction vessel was previously placed under a nitrogen atmosphere, and 155 mg of the modified TiCl ₃ prepared above was introduced, and the total amount of heptane as a polymerization solvent (including the amount of the heptane solution of Cp ₂ TiMe ₂ added later was also included in the calculation) to 100 ml. I added it. Polymerization temperature 40
After stirring at 5 ° C. for 5 minutes, nitrogen gas was exhausted, and 1-butene gas was introduced to saturate for 20 minutes. The polymerization pressure was 1 atm. The polymerization was then started by adding 8 ml of a heptane solution of Cp ₂ TiMe ₂ (0.25 mol / l). The polymerization was carried out for 15 minutes, and the polymerization was stopped by adding a hydrochloric acid-methanol solution to the polymerization system. The resulting polymer was thoroughly washed with methanol and dried under vacuum. The yield was 3.15 g.

Stereoregularity of formed polymer Stereoregularity of formed polymer (isotacticity)
Was evaluated by the following decane extraction method and ¹³ C NMR measurement.

The resulting polymer was extracted by decane extraction at room temperature as described in Polym. Bull., 11 , 485 (1984).
Was defined as an isotactic index (II). II of the polymer produced in this example was 98.3%. ^13C NMR measurement of polymer produced and decane-insoluble part by JEOL JEOL
Performed at 120 ° C. using JNH GX-500. As solvent for measurement
Hexamethyldisiloxane was used as an internal standard with 1,2,4-trichlorobenzene deuterated benzene (3/1 volume ratio). From the ¹³ C NMR measurement results of both polymers, the mmmm (mesomesomesomeso) chain fraction of the methylene carbon of the side chain ethyl group of 1-butene was calculated according to the method described in Polym. J., 16 , 895 (1984). Then, mm of the produced polymer
mm was 98.2%, and mmmm of the decane-insoluble portion was 98.8%.

Comparative Example 2 Polymerization of 1-butene TiCl ₄ prepared in Comparative Example 1 as component (a) during polymerization
Example 5 except that 50 mg of n-BP / MgCl ₂ catalyst, 8 ml of triethylaluminum in heptane (0.25 mol / l) and 4 ml of phenyltriethoxysilane in heptane (0.05 mol / l) were used as the component (b). Polymerization of 1-butene was carried out in the same manner as described above. The yield of the produced polymer was 8.17 g.

Stereoregularity of formed polymer Stereoregularity of formed polymer (isotacticity)
Was evaluated by the decane extraction method and ¹³ C NMR measurement in the same manner as in Example 5.

II of the resulting polymer was 91.1%. The mmmm of the 1-butene side chain ethyl group methylene carbon in the resulting polymer and the decane-insoluble portion were 81.0% and 84.5%, respectively.

Example 6 Polymerization of 4-methyl-1-pentene A 200 ml glass flask was used as a polymerization vessel.
The reaction vessel was previously placed under a nitrogen atmosphere, and 155 mg of the modified TiCl ₃ prepared in Example 1, 20 ml of 4-methyl-1-pentene, and the entire amount of heptane as a polymerization solvent [Cp ₂ TiMe _{2 was} added to a heptane solution of heptane to be added later. 100ml)
It was added to become. After stirring at a polymerization temperature of 40 ° C for 5 minutes, Cp ₂ T
The polymerization was initiated by adding 8 ml of a solution of iMe ₂ in heptane (0.25 mol / l). The polymerization was carried out for 15 minutes, and the polymerization was stopped by adding a hydrochloric acid-methanol solution to the polymerization system.
The resulting polymer was thoroughly washed with methanol and dried under vacuum. The yield was 1.87 g.

Stereoregularity of formed polymer Stereoregularity of formed polymer (isotacticity)
Was evaluated by the following decane extraction method.

The resulting polymer was obtained by extraction with decane at room temperature as described in Polym. Bull., 11,485 (1984).
Was defined as an isotactic index (II). The II of the polymer produced in this example was 99.2%.

Comparative Example 3 Polymerization of 4-methyl-1-pentene The TiCl ₄ prepared in Comparative Example 1 was used as the component (a) during polymerization.
Example 6 except that 50 ml of n-BP / MgCl ₂ catalyst (b), 8 ml of a solution of triethylaluminum in heptane (0.25 mol / l) and 4 ml of a solution of phenyltriethoxysilane in heptane (0.05 mol / l) were used. In a similar manner, 4-methyl-1-
The pentene was polymerized. The yield of the produced polymer was 5.01 g.

Stereoregularity of formed polymer Stereoregularity of formed polymer (isotacticity)
Was evaluated by the decane extraction method in the same manner as in Example 6.

 The resulting polymer had an I.I. of 89.1%.

[Effect of the Invention] According to the production method of the present invention, a highly stereoregular polyolefin having extremely few steric defects can be obtained with a high yield.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method for preparing a catalyst system used in the present invention.

Claims (1)

(57) [Claims] 1. A metal component comprising a) a solid component comprising δ-type titanium trichloride; and b) a metallocene comprising a cyclopentadienyl ring, which is represented by the following general formula [I] or [II] (Cyclo-R) ₂ M (CH ₃ ) ₂ [I] [Wherein (Cyclo-R) represents a cyclopentadienyl group or a methylcyclopentadienyl group, and M represents titanium or zirconium. A method for producing an olefin polymer, comprising using a catalyst system containing at least one of the compounds represented by the formula: