JPS6259126B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyolefins.

More specifically, the present invention relates to an industrially advantageous method for producing polyolefins by using a highly active catalyst system.

Conventionally, catalysts for olefin polymerization include α-type titanium trichloride obtained by reducing titanium tetrachloride with hydrogen, purple γ-type titanium trichloride obtained by reducing titanium tetrachloride with aluminum, or ball milling. δ-type titanium trichloride obtained by pulverization is known. Furthermore, as a method for modifying these catalysts, a method of mixing and pulverizing them together with various modifiers is also known.

Furthermore, a so-called supported catalyst in which magnesium chloride is treated with a titanium compound is also well known as a catalyst for olefin polymerization.

In olefin polymerization, it is industrially advantageous to be able to omit the deashing step, which is an operation for removing the catalyst remaining in the polymer, and therefore a search for a highly active catalyst is underway.

The present inventors also conducted intensive studies to obtain a highly active catalyst for this purpose, and as a result, they arrived at the present invention.

That is, in the present invention, in a system using a titanium compound and an organoaluminum compound during polymerization, magnesium dihalide is used as a titanium compound with the general formula
_CH2 =CH-CH2 _- O-R (R may contain an alkyl group having 1 to 10 carbon atoms, an ether group, or a glycidyl group) and/or the general formula
Ether compounds having an unsaturated group represented by CH ₂ =CH-O-R'(R' may be an alkyl group having 1 to 10 carbon atoms, or an ether group, a glycidyl group, or a halogen group) ( hydrogen at the α-position or β-position may be substituted with an alkyl group) and the general formula SiXn(OR″) _4-o (X is a halogen, R″ is an alkyl group, n is an integer from 0 to 4). By using a material that was mechanically brought into contact with a silicon compound and then treated with titanium tetrahalide, the polymerization activity was extremely high and this objective was achieved.

In the present invention, means for contacting the magnesium dihalogen compound with the ether compound and the silicon compound include a rotary ball mill and an impact mill.

Taking a rotary ball mill as an example, processing using these mills involves placing stainless steel balls with a diameter of 15 mm in a ball mill cylinder with an inner diameter of 110 mm and a depth of 110 mm.
It accommodates 30 to 150 pieces and crushes the material to be processed into 10 to 30 g.

At this time, the rotation speed is 70 to 200 rpm, and the processing temperature is 0.
It may be carried out at ~70°C, and can be carried out at room temperature.
Further, the contact time may be 40 hours or more.

In addition, in the preparation of this catalyst, the treatment with titanium tetrahalide after mechanical contact is carried out by suspending the contact-treated product in titanium tetrahalide or a titanium tetrahalide solution diluted with an inert solvent, and at 40°C.
to the boiling point of the solution by simple stirring for one hour or more.

Magnesium chloride, magnesium bromide, and magnesium iodide can be used as the magnesium dihalide used for preparing the present catalyst, and among these, magnesium chloride is most preferred.

The quantitative ratio of the treated compounds during the pulverization treatment is: magnesium dihalide is 1, ether compound with an unsaturated group is 0.01 to 0.5 mole, and silicon compound is 0.01.
~0.5 mole times.

By using an ether compound with an unsaturated group as the ether compound used here, a large activity increase effect was observed compared to the case of using an ether compound without an unsaturated group, and when used in the polymerization of propylene. also has the effect of improving stereoregularity.

Titanium tetrahalide is represented by the general formula TiX ₄ and includes titanium tetrachloride, titanium tetrabromide, and titanium tetraiodide, with titanium tetrachloride being the most preferred.

In this treatment with titanium tetrahalide, an inert solvent may be used as a diluent, and a hydrocarbon having 5 to 10 carbon atoms may be used.

The amount of titanium tetrahalide used in the titanium tetrahalide treatment is 1 to 10 times the mole of magnesium dihalide.

The use of the catalyst of the invention in polymerization can be carried out in the presence or absence of an inert solvent.

Hydrocarbons having 3 to 10 carbon atoms are used as the inert solvent, and hexane and heptane are generally used.

The temperature and pressure during polymerization may be the same as the conditions used for ordinary Ziegler catalysts, such as 200℃ or less, normal pressure to 50℃.
It is carried out in the range of Kg/cm ² G.

The amount of the catalyst used in the polymerization is such that the titanium compound is used in the range of 0.0001 to 1.0 mmol per titanium atom, and the organoaluminum compound is used in the molar ratio of aluminum to titanium of 1/1 to 100/1. Trialkylaluminum is the most effective organoaluminum compound in this invention.

The present invention will be explained below using specific examples, but the present invention is not limited by these examples.

Example 1 <Catalyst Preparation> 20.0 g of anhydrous magnesium chloride, 5.5 ml of isobutyl vinyl ether, and 3.0 ml of silicon tetrachloride were prepared in a diameter of 1.5 g.
The pot was placed in a stainless steel ball mill pot with an inner diameter of 110 mm and a depth of 110 mm containing 100 balls made of stainless steel (SUS32) with a temperature of 23 mm.
Leave in contact for 42 hours at ℃ and 120 rpm. The contact-treated solid is suspended in 150 ml of titanium tetrachloride and treated at 80° C. for 2 hours with stirring. The treated solid is filtered, thoroughly washed with dry n-hexane, and dried under reduced pressure.

The titanium content in the titanium compound thus obtained is 3.0 wt%. Using this product, an olefin polymerization reaction is carried out by the method shown below.

<Ethylene polymerization> In a well-dried and nitrogen-substituted autoclave with an internal volume of 2, add 1 hexane from which oxygen and moisture have been sufficiently removed.
0.1 ml of triethylaluminum and 45.3 mg of the above catalyst were added. Next, add hydrogen at 1.5Kg/cm ²
G was added, and ethylene was introduced at 70°C to start polymerization. Polymerization was carried out at an internal pressure of 3.0 Kg/cm ² G for 2 hours.
After stopping, the solid components were filtered to obtain 123 g of white powdered polyethylene. The activity of this catalyst is 45300g
It was PE/gTi・hr.

<Propylene polymerization> In a well-dried, nitrogen-substituted autoclave with an internal volume of 2, add 1 part of hexane with sufficient oxygen and moisture removed, and add 0.1 part of triethylaluminum.
87.5 mg of the above catalyst was charged. Polymerization was started by introducing propylene while stirring at 70°C. Polymerization was carried out for 2 hours while adjusting the internal pressure to 7 kg/cm ² G.
After stopping, isopropanol was added to the contents and the solid was filtered. The total amount of polymer produced (including the polymer in the filtrate) was 390 g. Therefore, the activity of this catalyst is 10600gPP/gTi・hr・propylene pressure (Kg/
cm ² ), and the percentage of boiling heptane insoluble matter ( ) was 73%.

Comparative Example 1 <Catalyst Preparation> A catalyst was prepared in the same manner as in Example 1 except that silicon tetrachloride was not added during pulverization. The Ti content in the produced catalyst component was 2.4% by weight.

<Ethylene polymerization> Polymerization was carried out in the same manner as in Example 1, except that 110.2 mg of the above catalyst was used, and 96 g of polyethylene was obtained.
I got it. The activity of this catalyst was 18100 gPE/gTi·hr.

Comparative Example 2 <Catalyst Preparation> A catalyst was prepared in the same manner as in Example 1 except that 7.0 ml of di-n-butyl ether was used instead of 5.5 ml of isobutyl vinyl ether. The Ti content in the produced catalyst component was 1.8% by weight.

<Ethylene polymerization> Polymerization was carried out in the same manner as in Example 1 except that 105.2 mg of the above catalyst was used, and polyethylene 60
I got g. The activity of this catalyst is 15900gE/gTi・hr
It was hot.

<Propylene polymerization> Polymerization was carried out in the same manner as in Example 1 except that 140.3 mg of the above catalyst was used, and polypropylene 161
I got g. The polymerization activity was 4600 gPP/gTi·hr·propylene pressure (Kg/cm ² ), and the proportion ( ) of boiling heptane insoluble matter was 59%.

Example 2 <Catalyst Preparation> 12.0 g of anhydrous magnesium chloride, 3.0 ml of allyl glycidyl ether, and 1.8 ml of silicon tetrachloride were prepared in a diameter of 15 mm.
The pot was placed in a stainless steel ball mill pot with an inner diameter of 110 mm and a depth of 110 mm containing 34 balls made of stainless steel (SUS32) with a temperature of 23 mm.
℃ and 120 rpm for 42 hours. The contact-treated solid is suspended in 90 ml of titanium tetrachloride and treated at 80° C. for 2 hours with stirring. The treated solid is filtered, thoroughly washed with dry n-hexane, and dried under reduced pressure.
The titanium content in the titanium compound thus obtained was 2.1% by weight.

<Ethylene Polymerization> A polymerization reaction was carried out in the same manner as in Example 1 except that 60 mg of the above catalyst was used to obtain 75 g of polyethylene.
The activity of this catalyst was 29,800 gPE/gTi·hr.

Example 3 <Catalyst Preparation> In Example 2, allyl glycidyl ether
A catalyst component was prepared in the same manner as in Example 2, except that 2.4 ml of ethyl vinyl ether was added instead of 3.0 ml for pulverization. Ti in the obtained catalyst
The content was 2.0% by weight.

<Propylene Polymerization> Polymerization was carried out in the same manner as in Example 1 using 98.4 mg of the above catalyst. Polymerization activity is 6300g/g
The Ti·hr·propylene pressure (Kg/cm ² ) and the proportion of boiling heptane insolubles () were 65%.

[Brief explanation of the drawing]

FIG. 1 shows a catalyst preparation diagram (flow chart).

Claims (1)

[Claims] 1. When producing a polyolefin using a titanium compound and an organoaluminum compound, a magnesium dihalide is used as the titanium compound according to the general formula CH ₂ =CH-CH ₂ -O-R (R is a carbon number of 1 to Ten
or an alkyl group containing an ether group or a glycidyl group) and/or a general formula CH ₂ =CH-O-R'(R' is an alkyl group having 1 to 10 carbon atoms, an ether group, or a glycidyl group). ether compounds with an unsaturated group (the hydrogens at the α- and β-positions may be substituted with an alkyl group) and the general formula SiXn (OR″) _{4 -o} (X is a halogen, R'' is an alkyl group, n is an integer of 0 to 4) mechanically contacted with a silicon compound, and then treated with titanium tetrahalide, using a fine particulate solid. A method for producing polyolefin. 2. The method according to claim 1, wherein the organoaluminum compound is trialkylaluminum.