JPS588687B2 - Method for producing olefin polymerization catalyst - Google Patents

Description

Detailed Description of the Invention The present invention relates to a method for producing an olefin polymerization catalyst, and more particularly, to a method for producing a catalyst in which a Ziegler-type catalyst component is chemically or physically supported in a gas phase on an inorganic compound suitable as a catalyst carrier. .

More specifically, in the present invention, magnesium halide particles heated to a high temperature are brought into contact with a transition metal halide vapor or a mixed gas of a transition metal halide vapor and an inert gas, and The present invention relates to a simple method for producing an olefin polymerization catalyst characterized by fixing a transition metal halide or a transition metal ion, and which has significantly increased polymerization activity per catalyst component.

Regarding a low-pressure polymerization method of ethylene using a transition metal compound and an organometallic compound, K. Many improved methods have been proposed since Ziegler's invention.

In recent years, research has been actively conducted on so-called high-activity catalysts whose activity has been increased to the point where catalyst removal is unnecessary, and many catalysts have already been developed and put into practical use.

For example, a catalyst is known in which a magnesium halide carrier is used and titanium halide is supported on the surface of the carrier.

However, the methods for manufacturing this supported catalyst include supporting catalyst components such as titanium halide on a support such as magnesium halide using a solvent in a liquid phase, or mechanically combining the support and titanium halide using a ball mill or other method. During the treatment process, it is necessary to wash using a solvent such as hexane to remove free titanium halide.

In addition, currently available highly active catalysts require many treatment steps other than the titanium halide treatment in order to obtain high activity, resulting in a very complicated catalyst manufacturing method.

The present inventors have arrived at the present invention as a result of intensive studies on a method for producing a catalyst that simplifies these complicated steps and has high activity.

An object of the present invention is to produce a highly active catalyst by a simpler method without using the conventional complicated catalyst production method.

To explain the present invention in more detail, it is a method for producing a catalyst by supporting titanium halide in a gas phase on a magnesium halide carrier heated to a high temperature. No complicated operations such as pre-processing are required.

It is also an attempt to obtain a highly active catalyst using only titanium halide and magnesium halide.

The present invention provides a method for producing a supported catalyst for olefin polymerization, which is obtained by heating magnesium halide particles to a predetermined temperature and contacting the particles with a mixed gas of titanium halide vapor and an inert gas. It is something.

In the present invention, typical magnesium halides include magnesium chloride, magnesium bromide and magnesium iodide, with magnesium chloride being particularly preferred.

These magnesium halides are preferably so-called anhydrides that do not contain water of crystallization, but they may usually contain a trace amount of water.

In addition, these halides may be used as carriers even if they contain impurities such as salts and oxides other than halides such as magnesium hydroxide, carbonate, and sulfate, and halides of metals other than magnesium. do not have.

The particle size of this carrier is preferably fine, but is not particularly limited, and ranges from 0.1 μm to 500 μm.
μm is preferably in the range of 0.1 μm to 10 μm.

The fine particles may be obtained by mechanically grinding using a commonly used ball mill or the like, or by directly synthesizing fine powder.

Before contacting the halogenated titanium component with the carrier, in order to dry the carrier as thoroughly as possible, the carrier is packed into a reaction tube and the carrier is heated under reduced pressure or in a sufficiently dried inert gas.
Preferably, the heat treatment is performed at a temperature in the range of 200°C to 600°C.

After this heat treatment, the magnesium halide carrier is brought into contact with a mixed gas of titanium halide vapor and an inert gas.

This inert gas may be any gas as long as it does not react with titanium halide or magnesium halide, such as gases of group O elements of the periodic table such as helium, argon, and neon, nitrogen, and halogen gases. Examples include hydrogen chloride.

Furthermore, it is preferable to use sufficiently dried gases.

On the other hand, the titanium halide includes titanium tetrafluoride, titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, etc., and titanium tetrachloride is preferably used.

Next, in order to obtain a gas mixture of titanium halide vapor and an inert gas, the titanium halide is usually heated in a range from above its melting point to below its decomposition temperature, and an inert gas is added to the titanium halide. Infuse.

At this time, the concentration of titanium halide in the mixed gas is determined by the heating temperature of titanium halide and the flow rate of inert gas, but if the flow rate of inert gas is constant, The concentration can be controlled by the heating temperature.

When titanium tetrachloride is used as the titanium halide, the heating temperature ranges from -24°C to 150°C, preferably from 10°C to 136°C.

In the method for supporting titanium halide, a mixed gas containing titanium halide is brought into contact with a magnesium halide carrier heated to a predetermined temperature in a reaction tube.

The heating temperature of the carrier at this time is in the range of 150°C to 700°C, preferably in the range of 200°C to 400°C.

The flow rate of the mixed gas varies depending on the amount of carriers in the reaction tube, the filling state, and the inner diameter of the reaction tube, but as long as the flow rate is at a level that does not significantly affect the filling state of the carriers,
Although not particularly limited, preferably 500ml of 0.5rrLl/WuIL/crA per unit cross-sectional area of the reaction tube.
! /min·cm2.

The concentration of titanium halide in the mixed gas is 0.1
You can choose anywhere from % to 99%, but in reality it is 1%.
A concentration of up to 20% is sufficient.

After the support for supporting and the mixed gas have been in contact for a predetermined time, the reaction tube containing the support is cooled to room temperature without passing the mixed gas, and only an inert gas is passed through the reaction tube for a while to remove the liberated halogen. Remove titanium chloride.

It is sufficient to do this for 30 minutes. The effects obtained by the present invention are as follows.

1. Compared to the conventional production method of a supported catalyst using a magnesium compound carrier and a titanium halide, which are already known, the production method according to the present invention simplifies the production of a highly active supported catalyst.

2. It was possible to obtain a highly active catalyst compared to the previously known catalyst in which a magnesium compound carrier and a titanium halide were supported in a liquid phase or by contact with mechanical means.

Using the catalyst thus produced, it is also possible to produce a copolymer by supplying a small amount of propylene, butene, styrene, etc. together with ethylene during polymerization.

However, in order to obtain highly crystalline polyethylene, ethylene needs to be present at 90% or more.

Next, the present invention will be further explained using examples.6 However, the present invention is not limited to these examples.

Example 1 Commercially available anhydrous magnesium chloride was ground in a ball mill in a nitrogen atmosphere for 60 hours.

5 g of this magnesium chloride carrier was filled in a Pyrex glass tube with an inner diameter of 25 mm in a nitrogen atmosphere, and heated and dried at 300° C. for 1 hour under reduced pressure using an electric furnace.

On the other hand, titanium tetrachloride was maintained at 19°C, and high-purity argon gas was blown into the titanium tetrachloride at a flow rate of 42 ml/min. It was introduced into a magnesium carrier and brought into contact with titanium tetrachloride.

The titanium tetrachloride concentration at this time was 0.95 mol %, and contact with the mixed gas was performed for 3.5 hours.

After cooling the glass tube to 100° C. or lower, the mixed gas was replaced with argon gas, and the tube was cooled to room temperature.

The supported catalyst thus prepared supported 1.3 mg of titanium per gram of solid.

1 liter of hexane was placed as a polymerization solvent in a 2 liter autoclave, and the temperature was raised to 70°C.
and triethylaluminum 0. After adding 15 mmol, the ethylene gas pressure was continuously increased to maintain the ethylene gas pressure at 3 kg/crA for polymerization.

After polymerization for 1 hour, 142 g of white polyethylene was obtained.

The polymerization activity per gram of titanium at this time is 103,000g.
PE/g Ti, hr. The pressure was C2H4.

The physical properties of polyethylene obtained by adding hydrogen to this catalyst before starting polymerization in order to adjust the molecular weight of the polymer are as follows: I, = 4.8g/10min, density -0
．． 9583g/cc, weight average molecular weight - 100,000, yield value - 306kg/crA, breaking strength - 224kg/cm2
The elongation rate was -1240%, the particle size of the polymer particles was also very uniform, and the bulk specific gravity was 0.3.

Example 2 A mixed gas containing 12 mo1% titanium tetrachloride and argon was applied to a magnesium chloride carrier heated and dried in the same manner as in Example 1 at 200°C for 5 hours at a flow rate of 42 ml/yni.
Contact was made with yr.

This gas mixture was placed in titanium tetrachloride heated to 70°C.
Obtained by passing argon gas.

The catalyst thus obtained was 1.8 μm/11 solids.
of titanium.

189m9 of this catalyst and 0.2m of triethylaluminum.
In the same manner as in Example I using 2 mmol, the ethylene pressure was 3. Polymerization was carried out at 70° C. for 1 hour to obtain 81 g of polyethylene.

The polymerization activity of Titanium 11 at this time was 79,000 g polyethylene/g Ti, hr, C2H4 pressure.

In addition, in order to adjust the molecular weight, the physical properties of polyethylene obtained by adding hydrogen before the start of polymerization are as follows: I. -28P/1
0mm, density -0.95 93g/cc, yield value -2
9 7kg/cm2, breaking strength = 29.0kg/cm2
, the elongation rate was -1327%.

Example 3 A magnesium chloride support heated and dried in the same manner as in Example 1 was brought into contact with the same gas mixture of titanium tetrachloride and argon as in Example 2 at 300° C. for 5 hours at a flow rate of 26 ml/min.

The catalyst thus obtained was 3.2 μg/g of solid.
of titanium.

170mg of this catalyst and 0.19g of triethylaluminum
Using mmol, polymerization was carried out in the same manner as in Example 1 at an ethylene pressure of 3.0 kg/cw2 at 70° C. for 1 hour to obtain 76 g of polyethylene.

The polymerization activity per gram of titanium at this time was 46,700 g polyethylene/g Ti, hr, C2H.

Furthermore, in order to adjust the molecular weight, the physical properties of polyethylene obtained by adding hydrogen before the start of polymerization are as follows: I. =2.5f
/10min, density -0.9573g/cc, yield value=
295kg/cm2, breaking strength -308kg/cm2,
The elongation rate was -1376%.

Example 4 A mixed gas containing 7.7 mo1% titanium tetrachloride and argon was applied to a magnesium chloride carrier heated and dried in the same manner as in Example 1 at 400°C for 6 hours at a flow rate of 42 ml/mi.
Contact was made at n.

This gas mixture was obtained by passing argon gas through titanium tetrachloride heated to 60°C.

The catalyst obtained in this way has a mass of 3.1 to 11 solids.
of titanium.

This catalyst 286 ~ and triethyl aluminum 0.2 2
mmol, and in the same manner as in Example 1, the ethylene pressure was 3. Polymerization was carried out at 70° C. for 1 hour at 0 kg/cm 2 to obtain 50 g of polyethylene.

The polymerization activity per gram of titanium at this time was 18,500 g polyethylene/g Ti, hr, C2H4 pressure.

In addition, in order to adjust the molecular weight, the physical properties of polyethylene obtained by adding hydrogen before the start of polymerization are: C, M, I. =1.3g
/10min, density -0.9604g/cc, yield value =
292 kg/ca, breaking strength -306 kg/cm2, and elongation rate = 1115%.

Example 5 In this example, sufficiently dried nitrogen gas was used to obtain a mixed gas containing titanium tetrachloride.

Using this gas mixture, a flow rate of 42 m
Contact was carried out for 5 hours at l/min.

The titanium tetrachloride concentration of this mixed gas was 12 mo1%.

The catalyst thus obtained contained 20 m9 of titanium per 12 solids.

This catalyst 180■ and triethylaluminum 0.20
Using mrnol, polymerization was carried out in the same manner as in the previous example at an ethylene pressure of 3.0 kg/cm 2 at 70° C. for 1 hour to obtain 101 g of polyethylene.

The polymerization activity per titanium 11 at this time was 93,500 g polyethylene/PTi, hr, C2H4 pressure.

Claims (1)

[Scope of Claims] 1. A method for producing an olefin polymerization catalyst, which comprises supporting titanium halide on magnesium halide in a vapor phase in an inert gas stream. 2. The method according to claim 1, wherein the temperature during supporting is 150 to 700°C. 3. The method according to claim 2, wherein the temperature during supporting is 200 to 400°C. 4. The method according to claim 1 or 2, wherein the inert gas is nitrogen, an element of group O of the periodic table, or hydrogen halide. 5 Titanium halide concentration in inert gas is 0.1 to 9
5. The method according to claim 1, 2 or 4, wherein the mixture is 9mol%. 6. The method according to claim 1, 2, 4 or 5, wherein the magnesium halide is magnesium chloride. 7. The method according to claim 1, 2, 4, 5 or 6, wherein the titanium halide is titanium tetrachloride.