JPH0713102B2 - Method for producing propylene polymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a propylene polymer.

According to the method of the present invention, a propylene polymer having extremely high stereoregularity can be industrially produced in a high yield.

Prior Art Conventionally, a catalyst system composed of a solid catalyst component in which a titanium compound is supported on magnesium halide and an organoaluminum compound has higher polymerization activity than conventional catalyst systems, and it is necessary to remove catalyst residues from the polymer. It has been said that it will disappear. However, although this carrier-type catalyst has low stereoregularity, it has been impossible to omit the atactic polymer extraction step, but in recent years, magnesium halide and titanium compounds have been used as solid catalyst components, and further electron donors, in particular A number of catalyst systems having considerably improved stereoregularity have been proposed by utilizing a carboxylic acid ester-containing compound (Japanese Patent Publication Nos. 52-36786 and 52-36913,
52-50037, etc.).

However, according to these proposals, in order to obtain a polymer having an industrially acceptable stereoregularity, in addition to the solid catalyst component and the organoaluminum compound component, an electron donor component, particularly a specific carboxyl group, is used. It was usually necessary to use acid esters. The resulting polymer has a major problem of odor due to the catalyst residue derived from the solid catalyst component and the electron donor component used during the polymerization.

It is difficult to eliminate such a cause of odor of the polymer by post-treatment, and it is disadvantageous in production.

Further, a solid catalyst component containing an electron donor such as an ester, which is used for producing a polymer having a high degree of stereoregularity in a high yield, contains a large amount of a solid catalyst component in the solid catalyst component preparation step.
A heat treatment step with TiCl ₄ is usually required. Therefore, the catalyst manufacturing apparatus and operation such as recovery and treatment of TiCl ₄ after use are complicated, and technical improvement of solid catalyst component manufacturing has been desired.

On the other hand, a method for producing a solid catalyst component for olefin polymerization which does not use an electron donor such as a carboxylic acid ester as described above has been proposed in JP-A Nos. 58-5311 and 54-78786. However, in these proposals,
In the case of the above-mentioned polymerization of α-olefin, a carboxylic acid ester is further used in addition to the solid catalyst component and the organoaluminum compound component, and the stereoregularity and activity of the obtained polymer are extremely low.

Further, in the polymerization of α-olefin having 3 or more carbon atoms,
Solid catalyst component, organoaluminum compound component and Si-
Proposals for using an organic silicon compound component having an OC bond have been made in JP-A-54-94590, JP-A-55-36203, and JP-B-58-21.
No. 921, JP-A No. 57-63310, and the like have been proposed, but each requires a large amount of heat treatment step of TiCl ₄ ,
It is in a state where improvement is desired.

Furthermore, in the polymerization of α-olefins having 3 or more carbon atoms, a solid catalyst component containing no electron donor such as carboxylic acid ester, an organoaluminum compound component, and Si-O
An example of using an organosilicon compound component having a -C bond is
Although disclosed in JP-A-56-41206 and JP-A-57-63312, none of them is sufficient from the viewpoint of stereoregularity, and the above technical problems have not been solved.

SUMMARY OF THE INVENTION The present invention provides a method for producing a propylene polymer by homopolymerizing or copolymerizing propylene in the presence of a catalyst, wherein the catalyst comprises a component (A): (i) magnesium halide, (ii) titanium A tetraalkoxide of (3) and (iii) a solid catalyst component which is a contact product of a halogen compound of silicon, component (B): an organoaluminum compound, and component (C): an organosilicon compound having a Si—O—C bond, The present invention provides a method for producing a propylene polymer characterized by being formed.

Effect of the Invention According to the method of the present invention, a propylene polymer having extremely high stereoregularity can be industrially produced in a high yield. Further, since no electron donor such as carboxylic acid ester is used as the catalyst forming component, the odor of the product polymer is remarkably improved.

In addition, the solid catalyst component according to the present invention does not require a heat treatment step with a large amount of TiCl _4, and therefore is significantly improved in industrial production of the solid catalyst.

Detailed Description of the Invention (Catalyst) The catalyst used in the method of the present invention comprises a component (A) and a component (B).
And component (C).

Component (A): Component (A) is a solid catalyst component, which is a contact product of component (i), component (ii) and component (iii).

Component (i) is a magnesium halide, preferably a magnesium dihalide such as MgCl ₂ , MgBr ₂ , MgI ₂ .

Further, as this magnesium halide, one produced during the catalyst production by the reaction of an alkoxy magnesium compound with a halogenating agent, for example, a halogen compound of silicon or a halogen compound of phosphorus of the component (iii) described later may be used. .

Organism (ii) is a titanium tetraalkoxide. The titanium tetraalkoxide has the general formula Ti (OR ² ) ₄ (R
² is a hydrocarbon residue). Specifically _{Ti (O-C 2 H 5} ) 4, Ti (O-isoC 3 H 7) 4, Ti
_{(O-nC 4 H 9)} 4, Ti (O-nC 3 H 7) 4, Ti (O-isoC 4 H
_{9) 4, Ti (O-} CH 2 CH (CH 3) 2) 4, Ti (O-C (C
_{H 3) 3) 4, Ti} (O-C 5 H 11) 4, Ti (O-C 6 H 13) 4,
_{Ti (O-C 7 H 15} ) 4, Ti (O-CH (C 3 H 7) 2) 4, Ti
_{(O-C 8 H 17)} 4, Ti (O-C 10 H 21) 4, etc. can be exemplified.

The component (iii) is a halogen compound of silicon, and a compound represented by the general formula R ³ nSiX _4- n can be used (wherein each R ³ is a hydrocarbon residue, X is halogen, and n is 1 ≦ n is a number of 4).

Specific examples of such compounds include SiCl ₄ , SiBr ₄ , and CH ₃ SiC.
l ₃ , C ₂ H ₅ SiCl ₃ , C ₃ H ₇ SiCl ₃ C ₄ H ₉ SiCl ₃ , C ₆ H ₁₃ SiCl ₃ , C ₆ H
₁₁ SiCl ₃ , C ₆ H ₅ SiCl ₃ , CH ₃ C ₆ H ₄ SiCl ₃ , C ₂ H ₃ SiCl ₃ , (C ₂ H
₅ ) ₂ SiCl ₂ , (C ₆ H ₅ ) ₂ SiCl ₂ , and (CH ₃ ) ₃ SiCl can be exemplified. Of course, two or more kinds of these halogen compounds of silicon may be used in combination.

The above-mentioned respective components are brought into contact with each other to synthesize the component (A), and the amount thereof is arbitrary as long as the effect of the present invention can be recognized, but generally, the following range is preferable.

The amount of component (ii) used is in the range of about 0.01 to about 100, more preferably about 0.1 to about 50, and particularly preferably about 1 to about 10 in molar ratio with respect to the magnesium dihalide of component (i). is there.

The amount of component (iii) used is in the range of about 0.1 to about 10, and particularly preferably about 1 to about 5 in molar ratio with respect to component (ii).

The contacting method comprises contacting the components (i) to (iii) all at once or stepwise or once or a plurality of times, and can be obtained by various preparation methods. The following are some of the specific preparation methods.

The component (i) magnesium halide and the component (ii) are mixed and pulverized, and the obtained pulverized product and the component (iii) are brought into contact with each other in a liquid phase.

Component (ii) is further contacted in the liquid phase with the contact product obtained in (1).

Component (i) is contacted with component (ii) in the liquid phase and then component (iii) is contacted in the liquid phase.

Component (i) is contacted with component (ii) in a liquid phase to prepare a hydrocarbon solution containing component (i), and this solution is contacted with component (iii) or a halogenating agent such as a halogen compound of titanium. A solid is deposited and the deposited solid and the component (ii
i) and component (ii) are contacted in the liquid phase either sequentially or simultaneously.

The above-mentioned contact can be performed in the presence of a dispersion medium. Examples of the dispersion medium in that case include hydrocarbons and halogenated hydrocarbons. Specific examples of hydrocarbons include:
There are hexane, heptane, toluene, cyclohexane and the like, and specific examples of the halogenated hydrocarbon include n-butyl chloride, 1,2-dichloroethylene, carbon tetrachloride, chlorobenzene and the like.

Further, in contacting the components (i) to (iii), a halogenating agent such as a halide of titanium or aluminum can be used in any step.

Component (B): Component (B) is an organoaluminum compound. The organoaluminum compound used in the present invention has the general formula AlR ⁴ nX _3- n (wherein R ⁴ is a hydrocarbon residue having 1 to 12 carbon atoms, X is a halogen or alkoxy group, and n is 0 <n.
Each of ≦ 3).

Specific examples of such an organoaluminum compound include triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, triisohexylaluminum, trioctylaluminum. , Diethyl aluminum hydride, diisobutyl aluminum hydride, diethyl aluminum monochloride, ethyl aluminum sesquichloride and the like. Of course, two or more of these organoaluminum compounds can be used in combination.

The use ratio of the organoaluminum compound component (B) and the solid catalyst component (A) used in the homopolymerization or copolymerization of propylene can be varied within a wide range, but generally, it is 1 to 1 per titanium atom contained in the solid catalyst component. Ten
The organoaluminum compound can be used in a ratio of 00, preferably 10 to 500 (molar ratio).

Component (C): The organosilicon compound component (C) having a Si—O—C bond used in the present invention is at least one Si—
It is a compound having an O—C bond, such as alkoxysilane aryloxysilane. Other examples include siloxanes having an alkoxy group, silyl esters of carboxylic acids, and the like.

More specifically, the following compounds can be exemplified. Trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, te
rt-Butylmethyldimethoxysilane, tert-butylmethyldiethoxysilane, 2-norbornanemethyldimethoxysilane, 2-norbornanediethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, ethyltrimethoxysilane, vinyltri Methoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, n-butyltriethoxysilane, tert
-Butyltriethoxysilane, phenyltriethoxysilane, chlorotriethoxysilane, 2-norbornanetriethoxysilane, 2-norbornenetriethoxysilane, 5-ethylidene-2-norbornanetriethoxysilane, 5-ethylidene-2-norbornanetrimethoxysilane Silane, tetraethoxysilane, etc.

Of these, phenyltrimethoxysilane, phenyltriethoxysilane, 2-norbornanetriethoxysilane, 2-norbornenetriethoxysilane, 5-ethylidene-2-norbornanetriethoxysilane, 5-ethylidene-2- is particularly preferable. Norbornanetrimethoxysilane, tert-butylmethyltrimethoxysilane, tert-butyltriethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane,
Particularly preferred are those having 2 to 3 alkoxy groups such as 2-norbornanemethyldimethoxysilane, 2-norbornanemethyldiethoxysilane, tert-butylmethyldimethoxysilane and tert-butylmethyldiethoxysilane.

The amount of the organosilicon compound component (C) having a Si—O—C bond used is usually 0.001 to 1 mol, preferably 0.01 to 0.5 mol, based on 1 mol of the organoaluminum compound.

The catalyst used in the present invention can be produced by contacting or mixing the above-mentioned solid catalyst component (A), organoaluminum compound component (B) and organosilicon compound component (C) having a Si—O—C bond. The order of this contacting or mixing and the number of times are not particularly limited, and a known contacting or mixing method can be adopted.

(Polymerization) Polymerization in the method of the present invention includes not only homopolymerization of propylene but also homopolymerization of propylene and α-olefins such as ethylene, 1-butene, 1-hexene, and 4-methylpentene, as well as mutual Random copolymerization and block copolymerization can be performed. Regarding copolymerization, polyunsaturated compounds such as conjugated dienes and non-conjugated dienes can also be used as the copolymerized olefin.

As the polymerization method, a so-called slurry polymerization method in which an inert hydrocarbon such as hexane or heptane is used as a solvent, a liquid phase polymerization method in which a liquefied monomer is used as a solvent, or a gas phase polymerization method in which a monomer is present as a gas phase can be used. .

The polymerization temperature is generally about 20 to 150 ° C, preferably 40 to 100 ° C.
The polymerization pressure is about atmospheric pressure to about 100 atmospheres, preferably about atmospheric pressure to about 50 atmospheres. The molecular weight of the polymer is controlled mainly by a method using hydrogen.

Examples Example 1 (Production of solid catalyst component (A)) Anhydrous MgCl ₂ 20 as component (i) under nitrogen atmosphere
g was charged into a vibrating mill pot with an internal volume of 1 liter [the pot contained approximately 800 cc (apparent volume) of stainless steel balls with a diameter of 25 mm), and titanium tetrabutoxide Ti (OBu) as component (ii) ₄ 5.0 ml [Ti (OBu) ₄ / MgCl ₂ = 0.
07 (molar ratio)] was mixed and pulverized for 6 hours and 16 hours, respectively, by a method of uniformly dividing the mixture to obtain a pulverized solid.

4.75 g of the obtained crushed solid was divided into 300 ml flasks, and 17.8 ml of SiCl ₄ was introduced as the component (iii) to disperse, and 26.2 ml of Ti (OBu) _{4 was} added dropwise while cooling the flask with water. After dripping more, contact treatment at 20 ℃ for 1 hour,
Further, contact treatment was carried out at 90 ° C. for 4 hours. After that, the supernatant liquid was removed, and the solid was washed by decanting four times with 200 ml of n-heptane to obtain a desired solid catalyst component (A) slurry (titanium was 2.68 in the solid catalyst component).
It was contained by weight%).

(Polymerization of Propylene) A 1-liter stainless steel autoclave with a stirring and temperature control device was repeatedly vacuum-propylene substituted several times and then thoroughly dehydrated and deoxygenated.
-500 ml heptane, 107 m phenyltriethoxysilane
g, triethylaluminum 250 mg, and 0.5 mg in terms of Ti atom from the above solid catalyst component slurry were introduced in this order under a propylene atmosphere, and 80 ml of hydrogen was added to initiate polymerization. Polymerization was carried out at a propylene pressure of 7 kg / cm ² G and 70 ° C. for 3 hours. After the completion of the polymerization, residual monomers were purged, the polymer slurry was separated, and the amount of each polymer produced was determined by drying the powder polymer and concentrating the liquid.

Stereoregularity of this powder polymer (hereinafter referred to as product II)
Was determined by a boiling n-heptane extraction test. Also, all
II (ratio of boiling n-heptane-insoluble polymer amount to total produced polymer amount) is total II = powder polymer amount x product II
It was determined by the relational expression: / (amount of powder polymer + amount of liquid concentrated polymer). The results are shown in Table 1.

Example 2 30 ml of dehydrated and deoxygenated n-heptane was introduced into a 300 ml flask which had been sufficiently replaced with nitrogen, and then 2.85 of MgCl ₂ was added.
After introducing 51 ml of g, (TiOBu) _{4, the} mixture was reacted at 90 ° C. for 2 hours to prepare a hydrocarbon solution of MgCl ₂ . Then -20 ℃
When the temperature was lowered to 25.8 ml of SiCl ₄ and the temperature was gradually raised, a solid was precipitated at 30 ° C. The temperature was further raised to 50 ° C. and the reaction was carried out for 4 hours. This solid was added to n-heptane at 50 ° C.
It wash | cleaned 4 times by the decantation method in 200 ml.
The obtained off-white solid [solid catalyst component (A)] contained 3.71% by weight of titanium.

Polymerization of propylene was carried out in exactly the same manner as in Example 1 except that this solid catalyst component (A) was used. The results are shown in Table-1.

Examples 3 to 4 In the production of the catalyst component of Example 2, Ti (OBu) ₄ and SiC
A solid catalyst component was produced in exactly the same manner as in Example 2 except that the amount of l ₄ shown in Table 1 was used. Polymerization of propylene was carried out in the same manner as in Example 2 except that the obtained solid catalyst component (A) was used. The results are shown in Table-1.

Comparative Example 1 A solid catalyst component (A) was produced in exactly the same manner as in Example 2 except that 0.64 ml of ethyl benzoate was used together with SiCl ₄ in the production of the catalyst component of Example 2. Polymerization of propylene was carried out in exactly the same manner as in Example 2 except that this solid catalyst component (A) was used. The results are shown in Table-1.

Comparative Example 2 Using the same solid catalyst component used in Example 4, 78.4 mg of ethyl benzoate was used instead of phenyltriethoxysilane.
Propylene was polymerized exactly as in Example 2 except that it was used. The results are shown in Table-1.

Example 5 10 g of diethoxymagnesium and 33.4 ml of SiCl ₄ were introduced into a 300 ml flask equipped with a stirrer that had been sufficiently replaced with nitrogen, and Ti (OBu) ₄ 34.6 m was added while cooling the flask with water.
l was added over 30 minutes. Then, after reacting at 80 ° C. for 4 hours, the mixture was allowed to stand and the supernatant was extracted. Furthermore, the temperature is 20 ℃.
After that, 33.4 ml of SiCl _{4 and} 49.5 ml of Ti (OBu) ₄ were introduced, and the mixture was reacted at 80 ° C. for 4 hours. The resulting solid at 50 ° C
It was washed 4 times by decantation with 200 ml of n-heptane. Thus, the obtained solid catalyst component (A) contains
It contained 1.72% by weight of titanium.

Polymerization of propylene was carried out by replacing phenyltriethoxysilane in Example 1 with tert-butylmethyldimethoxysilane.
The procedure of Example 1 was repeated except that 142 mg was used. The results are shown in Table-1.

[Brief description of drawings]

FIG. 1 is intended to help the understanding of the technical content of the present invention regarding the Ziegler catalyst.

Claims (1)

[Claims] 1. A method for producing a propylene polymer by homopolymerizing or copolymerizing propylene in the presence of a catalyst, wherein the catalyst comprises component (A): (i) magnesium halide, (ii) titanium tetraalkoxide. And (iii) a solid catalyst component which is a contact product of a halogen compound of silicon, component (B): an organoaluminum compound, and organism (C): an organosilicon compound having a Si—O—C bond. What is claimed is: 1. A method for producing a propylene polymer, characterized in that