JPH1180218A - Gas velocity control method of vapor phase polymerization reactor and vapor phase polymerization method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas velocity control method of a vapor phase polymn. vessel which can steadily control the gas linear velocity for a long time without using a differential pressure flow meter and steadily measure the recycle gas quantity for a long time with high precision. SOLUTION: This gas phase olefin polymn. device comprises an olefin polymn. device using a fluidized bed vapor phase polymn. reactor 1 containing a solid catalyst component, a recycle device, including 8 and 11, which recycles the gas contg. a polymn. component taken out of the deceleration region 7 in the upper part of the fluidized bed vapor phase polymn. reactor as a recycle gas to the fluidized bed vapor phase polymn. reactor 1, and a supply device 9 which newly supply the olefin to the fluidized bed vapor phase polymn. reactor 1. In this case, an ultrasonic flow meter 13 is equipped on the recycle device and this ultrasonic flow meter 13 measures the recycle quantity of the polymn. component contg. gas and control the rate of the gas forming the fluidized region 3 in the fluidized bed gas phase polymn. reactor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas velocity control method and a gas phase polymerization method for a gas phase polymerization vessel, and more particularly, to performing a gas phase polymerization of an olefin in a gas phase polymerization vessel. The present invention relates to a gas velocity control method for a circulating gas to be circulated, and a gas phase polymerization method for carrying out a gas phase polymerization of an olefin using the gas velocity control method.

[0002] The terms "polymerization" and "polymer" used herein are "homopolymerization" and "copolymerization" and "homopolymer" and "copolymerization", respectively, unless otherwise specified. It is used in the sense including "coalescing".

[0003]

2. Description of the Related Art Polyethylene, linear low-density polyethylene (LL) which is a copolymer of ethylene and an α-olefin
An olefin polymer represented by DPE) is widely used, for example, as a film forming material.

[0004] Olefin polymers are produced using Ziegler-type or metallocene-type catalysts.

[0005] Recent improvements in transition metal catalysts for olefin polymerization have dramatically improved the olefin polymer production capacity per unit amount of transition metal. For this reason, the catalyst removal operation after the polymerization has been omitted.

[0006] When such a highly active catalyst is used for polymerization, a method of performing olefin polymerization in a gas phase is generally employed because the polymerization operation can be easily performed. In such a gas-phase polymerization, in order to smoothly perform the gas-phase polymerization, a fluidized-bed gas-phase polymerization reactor (hereinafter, simply referred to as a “polymerization reactor”) having therein a member called a gas dispersion plate having a large number of holes is usually used. ) Is used.

In a polymerization vessel provided with a gas dispersion plate, an olefin or an olefin-containing gas (hereinafter, collectively referred to as "olefin etc.") is generally introduced from a lower portion thereof through an introduction pipe equipped with a compressor or a blower. I do. Then, gas such as olefin entering the polymerization vessel rises in the polymerization vessel while being uniformly dispersed by the gas dispersion plate. Gas phase polymerization is performed in a polymerization vessel by flowing the raised olefin and the like in the fluidized bed region located above the gas dispersion plate while contacting the catalyst particles.

[0008] When the gas phase polymerization is carried out, an olefin polymer is formed on the surface of the catalyst particles. Therefore, solid particles composed of the catalyst particles and the olefin polymer float in the fluidized bed area. That is, the polymer is obtained in the form of particles. For this reason, a step of precipitating the particles after the polymerization or a step of separating the particles are not required, and the production process is simplified.

Further, not all of the gas such as olefin introduced into the polymerization vessel is subjected to the polymerization reaction, and a so-called unpolymerized gas which is not subjected to the polymerization reaction is produced. The unpolymerized gas is taken out from the upper part of the polymerization reactor as a polymerization component-containing gas to the outside of the polymerization reactor, cooled with cooling water, brine, or the like, and then sent again to the polymerization reactor from the lower part by a compressor or a blower. By doing this,
Reuse of unpolymerized gas, so-called cyclic use. In addition,
A circulation pipe for reusing the unpolymerized gas in the polymerization vessel is referred to as a circulation line.

[0010] In order to operate the polymerization vessel having such a structure stably and efficiently over a long period of time, the following measures are required. (1) Prevent heat spots in the fluidized bed zone, which is the polymerization zone of the gas phase polymerization. (2) Prevent fusion of the polymer particles in the fluidized bed area. (3) Prevent the generation of non-flowable or poor-flowing polymer particles.

As one of the main operating factors of the polymerization reactor for stabilizing and efficiently operating the polymerization reactor for a long period of time as described above while making these measures effective, the gas velocity in the fluidized bed zone, so-called, One example is to control the linear velocity of gas (hereinafter referred to as "gas linear velocity") well.

The gas linear velocity is obtained by dividing the volume velocity of the gas flowing in the fluidized bed area by the sectional area of the fluidized bed area. If the temperature, pressure, and cross-sectional area of the fluidized bed area are constant, the gas linear velocity is determined by the total amount of gas and circulating gas supplied from outside to the polymerization reactor.

The main purpose of supplying gas from outside the polymerization vessel is to replenish the raw materials consumed in the polymerization vessel. In addition, control of the amount of circulating gas (hereinafter referred to as “circulating gas amount”) plays an important role in controlling the gas linear velocity that stabilizes the fluidized bed region. Therefore, it is important to accurately measure the amount of circulating gas. In the prior art, when measuring the amount of circulating gas, a restrictor is provided in the piping of the circulating line, and a differential pressure type flow meter for measuring the differential pressure at both ends to determine the flow rate of the circulating gas is used.

[0014]

However, fine powdery polymer particles, which are insufficiently grown in the polymerization system, and fine powdery particles formed by the collapse of the solid catalyst component during polymerization, are necessarily mixed into the circulating gas. Therefore, the measurement of the amount of circulating gas using the differential pressure type flow meter has the following problems. When the type of the differential pressure type flow meter is an orifice type or a venturi type, since the catalyst and polymer particles contained in the circulating gas adhere to the orifice and the venturi, they are easily clogged, and therefore, the differential pressure type flow meter was used. It is difficult to measure the amount of circulating gas stably for a long time. When the type of the differential pressure type flow meter is the orifice type or the V-cone type, the differential pressure at the orifice or the V-cone portion is large, and the power loss of the blower for circulating the circulating gas tends to be large.

On the other hand, in the case of the above-mentioned orifice-type or venturi-type differential pressure-type flowmeter, if the particles are blocked due to adhesion of polymer particles or the like to the orifice or the venturi, in order to solve this, a differential pressure-type flowmeter is used. It is conceivable to provide a bypass line. In this case, a method is known in which the measurement line of the differential pressure type flow meter is normally closed, and the differential pressure type flow meter is operated by closing the bypass line while opening the measurement line of the differential pressure type flow meter only when flow rate measurement is necessary. Have been.

Conversely, the circulating gas is circulated while measuring the flow rate in the circulating line by the differential pressure type flow meter,
There has been known a method in which when a differential pressure type flowmeter becomes unstable, a bypass line is opened to stop the flow of circulating gas into a measurement line of the differential pressure type flowmeter, thereby removing a blockage.

However, according to this method, the valve switching operation for opening the bypass line is complicated, and it is necessary to open and clean the line containing combustibles. It takes a long time to open the door, and it is necessary to arrange a large number of personnel to perform the opening work, which is inefficient.

Also, the differential pressure type flowmeter tends to be expensive as the circulating gas flow rate increases. Furthermore, it is not possible to completely prevent a decrease in flow rate measurement accuracy due to adhesion of polymer particles or the like.

The present invention has been made in view of the above-mentioned circumstances, and is capable of accurately and stably measuring the amount of circulating gas for a long period of time and stably measuring the gas linear velocity for a long period of time. An object of the present invention is to provide a method for controlling the gas velocity of a gas phase polymerization reactor, and a method for polymerizing an olefin by forming a fluidized bed region in a stable state by using the gas velocity control method.

[0020]

Means for Solving the Problems In order to solve the above-mentioned problems, a gas speed control method and a gas phase polymerization method for a gas phase polymerization vessel according to the present invention are as follows. (1) An olefin polymerization facility using a fluidized-bed gas-phase polymerization device for performing gas-phase polymerization using a solid catalyst component, and polymerization taken out from a deceleration region located above the fluidized-bed gas-phase polymerization device. The component-containing gas is circulated back to the fluidized-bed gas phase polymerization vessel, and a circulation line for using the gas as a circulating gas, and an olefin newly supplied to the fluidized-bed gas phase polymerization vessel is supplied with the olefin. A supply line for supplying to a phase polymerization vessel, and in an olefin gas phase polymerization facility having an ultrasonic flow meter provided on the circulating line, and the ultrasonic gas flow meter controls the circulating gas flow rate Vc of the polymerization component-containing gas. It is characterized in that the gas velocity of a gas flow forming a fluidized bed region in the fluidized bed type gas phase polymerization reactor is controlled based on the measurement result. (2) In the above (1), a flow meter is further provided in the supply line to measure the flow rate Vi of the newly supplied olefin, and based on the value obtained by adding the flow rate to the measurement result of the circulating gas flow rate Vc. Thus, the gas velocity of the gas flow forming the fluidized bed region in the fluidized bed type gas phase polymerization vessel can be controlled. (3) In the above (2), the temperature Tp inside the fluidized bed area
And the pressure Pp, and the flow rate Vc of the circulating gas, the flow rate Vi of the newly supplied olefin, the temperature Tp, the pressure
The gas velocity inside the fluidized bed area is calculated from Pp and the cross-sectional area Af of the fluidized bed area, and the calculated gas velocity and a gas velocity allowable range (gas linear velocity) which is one of the polymerization conditions set in advance. Deviation from the permissible range), the gas velocity of the gas flow forming the fluidized bed region may be controlled based on the deviation.

Further, the temperature Tp and pressure P inside the fluidized bed area
p, the flow rate Vc of the circulating gas, the flow rate Vi of the newly supplied olefin, and the cross-sectional area Af of the fluidized bed area as parameters.
The gas linear velocity x inside the fluidized bed area is obtained by the following equation.

X = (Vi ′ + Vc) · Z · (Tp + 273) · B / (273 · (Pp + B) · Af) (1 equation) where Vi ′ = Vi · (Pp / P) ^1/2 -(T / Tp) ^1/2 P: Design value of polymerization reaction T: 〃 B: Atmospheric pressure Z: Gas compression coefficient (4) In (1), gas velocity of gas flow forming the fluidized bed area May be controlled by controlling the volume velocity of the circulating gas. (5) In the above (2) or (3), as a method of controlling the gas velocity of the gas flow forming the fluidized bed region, the volume velocity of the circulating gas may be controlled. (6) In the above (5), the method of controlling the gas velocity of the gas stream forming the fluidized bed region may further include controlling the volume velocity of the newly supplied olefin. (7) As the gas phase polymerization method, it is preferable to carry out the gas phase polymerization of the olefin using the control method of (1) to (6).

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings. (Polymerizer 1) As shown in FIG. 1, the polymerizer 1 has a straight body 1a extending downward in a test tube. A gas dispersion plate 2 is provided below the straight body 1a. The inner space of the polymerization vessel 1 is vertically divided by the gas dispersion plate 2. By doing so, a fluidized bed region 3 and a gas introduction region 4 for performing gas phase polymerization are formed in the upper part and the lower part of the polymerization vessel 1 with the gas dispersion plate 2 as a boundary.

The upper part of the fluidized bed zone 3 of the polymerization vessel 1 is a deceleration zone 7 for reducing the flow velocity of the gas entering the polymerization vessel 1 to prevent particles from escaping from the polymerization vessel 1.

In the polymerization vessel 1, a catalyst supply pipe 5 for supplying a catalyst to the polymerization vessel 1 and a produced polymer are taken out of the polymerization vessel 1 substantially at a central portion and a lower portion of a portion corresponding to the fluidized bed region 3. For taking out the produced polymer is connected. Also, at the top of the polymerization vessel 1, an outlet 11 is provided.
And a gas circulation pipe 8 for circulating gas from the polymerization vessel 1 is connected to the outlet 11.

The catalyst supply pipe 5 may be arranged so that it is located near the dispersion plate 2.

The solid catalyst and the organometallic compound catalyst component, or each compound such as an electron donor, if necessary, are supplied to the polymerization reactor 1 from outside the polymerization reactor 1 through a catalyst supply pipe 5.

The solid catalyst component is supplied to the polymerization reactor in the form of a dry solid powder or suspended in a hydrocarbon.

In the case of prepolymerizing an olefin, the polymerization is carried out using a catalyst component of an organometallic compound or, if necessary, an electron donor. These compounds are also supplied to the polymerization reactor 1 together with the pre-polymerization catalyst.

An olefin to be polymerized or, if necessary, a low-boiling non-polymerizable hydrocarbon or an inert gas is introduced into a gas introduction zone 4 at a lower portion of the polymerization vessel 1 bordered by the gas dispersion plate 2. And a gas supply pipe 9 for supplying the contained gas to the polymerization reactor 1. Therefore, the gas introduction area 4 is also called a gas chamber. A gas supply pipe 9 is provided in the gas introduction area 4.
Is introduced into the fluidized bed region 3 through the gas dispersion plate 2 and undergoes gas phase polymerization while flowing in the fluidized bed region 3. The fluidized bed zone 3 can be stirred using mechanical means (not shown). Various agitators such as an squid-type agitator, a screw-type agitator, and a ribbon-type agitator can be applied to the agitator.

In the circulation pipe 8, an ultrasonic flowmeter 13, a heat exchanger 10, and a blower 12 are arranged in this order. The circulating gas that has entered circulates through the gas supply pipe 9 to the gas introduction area 4. At least the circulation pipe 8 provided with the ultrasonic flowmeter 13 in the middle and a part of the gas supply pipe 9 constitute a circulation line.

The circulating gas from the polymerization vessel 1 passes through a gas circulation pipe 8 and is cooled in a heat exchanger 10. And
This cooling removes the heat of polymerization contained in the exhaust gas. At this time, the exhaust gas may be cooled until a condensed liquid is formed in part of the exhaust gas within a range that does not impair the stability of the fluidized bed region 3. The circulating gas after being cooled by the heat exchanger 10 is separated into a condensed liquid and a gas as needed. After this separation, the condensate is circulated using a pump (not shown), and the gas is circulated from the circulation pipe 8 via the blower 12 to the gas introduction area 4 via the gas supply pipe 9.

The circulating gas cooled by the heat exchanger 10 is supplied to the polymerization reactor 1 by a gas supply pipe 9 constituting a supply line.
Is introduced into the gas introduction zone 4 together with a new gas newly supplied from the outside to form the fluidized bed zone 3. In addition to the supply of the condensed liquid from the circulation pipe 8 to the polymerization reactor 1, the condensed liquid may be supplied from another pipe (not shown). At this time, the olefin and / or the non-polymerizable hydrocarbon having a low boiling point are usually in a gaseous state, and are supplied to the polymerization reactor 1 at a flow rate capable of maintaining the polymerization zone 3 in a fluid state. Specifically, olefins and / or low-boiling non-polymerizable hydrocarbons, when their minimum fluidization rate is Umf, are between about 3 Umf and 50 Umf.
It is preferable to set the flow rate.

Umf is represented by the gas linear velocity obtained by dividing the volume velocity of the gas passing through the fluidized bed region 3 by the cross-sectional area of the fluidized bed region 3. Then, based on the gas linear velocity of the circulating gas measured by the ultrasonic flow meter 13 or a value obtained by adding the gas linear velocity of the newly supplied olefin to the gas linear velocity of the circulating gas, Gas linear velocity of 10 cm / sec to 20
It is preferable to control within a range of 0 cm / sec. Since the fluidized line region 3 is formed stably when the gas linear velocity is in this range, the gas flow in the fluidized bed region 3 is controlled by measuring the flow rate of the circulating gas with the ultrasonic flowmeter 13 in a stable state. In addition to the above, more stable olefin polymerization can be performed.

If the temperature, pressure and cross-sectional area of the fluidized bed region 3 are constant, the gas linear velocity is the gas volume of the gas blown from the gas introduction region 4, that is, the gas flow newly supplied from the gas supply pipe 9. And the sum of the volume velocities of the gas flows circulated from the circulation pipe 8 to the polymerization reactor 1. The gas component of the gas stream newly supplied from the gas supply pipe 9 is mainly used for replenishing olefins consumed in the polymerization reactor 1. The amount of the supplied gas is smaller than the amount of the circulating gas. Therefore, it is important to control the volume velocity of the gas supplied from the circulation line to the gas introduction area 4.

However, the gas in the circulation line may contain a small amount of a powdery polymer, and it is difficult to perform a stable measurement using a flow meter such as a differential pressure type flow meter. .

In the embodiment of the present invention, the flow rate of the gas containing the powdery polymer is measured stably and accurately for a long period of time, and the circulating gas is suitably controlled based on the measurement result.

In the embodiment of the present invention, the circulating gas flow rate Vc is measured by the ultrasonic flow meter 13 installed in the circulation pipe 8 of the circulation line, and the gas velocity for forming the fluidized bed region 3 is controlled.

Further, the gas velocity for forming the fluidized bed region 3 is controlled by controlling the volume velocity of the circulating gas.

Further, the gas linear velocity of the gas-phase polymerization reactor 1 is suitably controlled by controlling the volume velocity of the newly supplied olefin.

More specifically, the ultrasonic flow meter 13
Circulating gas flow rate storage means for storing the measurement result of the circulating gas flow rate Vc as an output signal, and outputting a signal corresponding to the supply gas flow rate (olefin flow rate) Vi of the supply line 9; Gas flow rate storage means for measuring the temperature Tp in the fluidized bed area inside the fluidized bed area 3 and outputting the measurement result, and measuring the pressure Pp inside the fluidized bed area. The flow is measured by a pressure measurement output unit that outputs a measurement result and the circulating gas flow rate Vc, the supply gas flow rate Vi, the fluidized bed area temperature Tp, the fluidized bed area pressure Pp, and the cross-sectional area Af of the fluidized bed area 3. Gas linear velocity deviation detecting means for calculating a gas linear velocity inside the stratum 3 and detecting a deviation between the calculated gas linear velocity and a gas linear velocity allowable range which is one of preset polymerization conditions;
And controls the amount of circulating gas in the circulating pipe 8 by outputting the detection result of the gas line speed deviation detecting means as a signal.

In this manner, the gas supply pipe 9
Not only can the gas flow entering the fluidized bed zone 3 through the fluidized bed zone 3 be accurately corrected, but also the flow rate of the gas entering the fluidized bed zone 3 through the circulation pipe 8 can be accurately measured by the ultrasonic flow meter 13. The gas flow velocity in the fluidized bed region 3 can be accurately known by the ultrasonic flow meter 13.

Further, as a specific method of obtaining the gas linear velocity, the temperature Tp, the pressure Pp, the flow rate Vc of the circulating gas, the flow rate Vi of the newly supplied olefin, and the cutoff of the fluidized bed area are obtained. Using the area Af as a parameter,
It is good to apply to the formula.

X = (Vi ′ + Vc) · Z · (Tp + 273) · B / (273 · (Pp + B) · Af) (1 equation) where Vi ′ = Vi · (Pp / P) ^1/2・ (T / Tp) ^1/2 P: Design value of polymerization reaction T: 〃 B: Atmospheric pressure Z: Gas compression coefficient (Method of controlling gas flow velocity) To control gas linear velocity in fluidized bed zone 3 Can be controlled by controlling the flow rate of the circulating gas occupying most of the gas entering the fluidized bed region 3. For this purpose, a method of changing the rotation speed of the blower 12 provided in the circulation pipe 8, a part of the flow path, for example, the blower 12. There is a method of providing an orifice or the like (not shown) for changing the size of the cross section of the flow path near the entrance of the nozzle and adjusting the orifice, or a method of simultaneously performing the two methods. In this case, the rotation speed and the orifice of the blower may be adjusted so that the gas linear velocity obtained by the ultrasonic flow meter 13 approaches the appropriately set velocity.

At this time, in order to improve the calculation accuracy of the gas linear velocity, gas is sampled from the circulation pipe 8 and the gas composition is automatically or manually measured using a gas chromatograph, and the result is input to the calculation means. This operation may be performed automatically or partially automatically.

When controlling not only the circulating gas but also the newly supplied gas amount, the blower or orifice (not shown) provided in the gas supply pipe 9 may be controlled in the same manner as described above. (Ultrasonic flow meter 13) The ultrasonic flow meter 13 may be any as long as it can measure the flow rate with an error within 5%. Ultrasonic flowmeters are usually designed to measure the flow rate by the phase difference method and the propagation velocity method, but among them, the ultrasonic flowmeter employing the propagation velocity method has good measurement accuracy and is inexpensive, This will be exemplified.

The propagation speed of the ultrasonic wave is affected by the flow velocity of the fluid through which the ultrasonic wave propagates. Let C be the speed of sound in the fluid when the fluid is at rest, and assume that the propagation direction of the ultrasonic wave is along the flow of the fluid when the fluid is flowing at the flow velocity V. If this direction is referred to as a forward direction, the propagation speed in that case is C + V. If the propagation direction of the ultrasonic wave in the circulation pipe 8 is opposite to the forward direction as shown in FIG. The propagation speed is CV.

Now, it is assumed that two sets of transceivers S1, J1, S2, and J2 are installed at a fixed distance L, and that the transmitter S1 emits a sound wave in the forward direction and the transmitter S2 emits the sound wave in the reverse direction. .
In this case, if the time required for the receivers J1 and J2 corresponding to the transmitter S1 and the transmitter S2 to receive the sound waves is t1 and t2, respectively,
The required times t1 and t2 are respectively t1 = L / (C +
V) and t2 = L / (C−V).

Since the sound speed C and the distance L are constant values, V can be obtained from the difference between the required times t1 and t2. This V is the gas linear velocity, and the volume velocity of the circulating gas as a fluid can be calculated from this V and the cross-sectional area of the circulating gas line. By integrating this volume velocity in an appropriate time width, the circulating gas flow rate in that time width is obtained.

It is preferable that the ultrasonic flowmeter 13 is provided on the upstream side of the heat exchanger 10 as a cooler. This is because even if condensation occurs in the circulating gas in the heat exchanger 10 and mist is generated there, the ultrasonic flowmeter 13 is not affected by the mist. (Gas Dispersion Plate 2) The gas dispersion plate 2 used in the fluidized bed zone polymerization vessel 1 has a large number of gas passage holes (not shown) formed concentrically. Gas flows from the gas introduction region 4 to the fluidized bed region 3. (Overcap of gas dispersion plate 2) It is general to provide a so-called overcap on the gas passage hole of the gas dispersion plate 2 so as to cover the gas passage hole from above. Although the illustration of the overcap is omitted, by providing the overcap on the gas passage hole, it is possible to prevent the powdery polymer or the like falling from the fluidized bed region 3 from entering the gas passage hole.

The overcap has a shape (for example, V) that spreads toward the outflow side of the gas flow from the overcap.
And a swirling flow is formed in the same direction along the concentric circle of the gas passage hole. (Polymerization conditions) The olefin used for the gas phase polymerization of the olefin in the polymerization vessel 1 equipped with the gas dispersion plate 2 has 2 carbon atoms.
~ 18 alpha-olefins are preferred.

Such olefins include, for example,
Ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-
Heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene,
1-octadecene, isoprene, 1,4-hexadiene,
Butadiene and the like.

Further, cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, dicyclopentadiene, 5-ethylidene-2-norbornene,
Tetracyclododecene, 2-methyl 1,4,5,8-dimethano-1,
2,3,4,4a, 5,8,8a-octahydronaphthalene, styrene,
And vinylcyclohexane.

These olefins are used alone or in combination as long as the gas phase polymerization is possible.

Usually, homopolymerization of ethylene or propylene, or copolymerization of ethylene or propylene with another olefin.

In addition, hydrogen gas can be used together with the above-mentioned olefin for the purpose of adjusting the molecular weight and the like.

The polymerization conditions in the main polymerization step vary depending on the olefin to be polymerized and the flow state of the polymerization system (fluidized bed zone) 3, but usually the polymerization temperature is from 20 to 200 ° C.
And the polymerization pressure is from 1 to 100 kg / cm 2. (Polymerization catalyst) The catalyst to be used is not particularly limited, but a catalyst containing a transition metal compound catalyst component is preferable. The transition metal compound catalyst component is a compound of a transition metal such as titanium, vanadium, chromium, and zirconium, and can be used in either a liquid state or a solid state depending on use conditions. Further, these catalysts do not need to be a single compound and may be supported on another compound, may be a homogeneous mixture with another compound, and may be a complex compound with another compound or It may be a multiple compound.

The catalyst containing such a transition metal compound catalyst component includes a known Ziegler-Natta type catalyst and a metallocene catalyst.

First, the Ziegler-Natta type catalyst will be described.

The highly active titanium catalyst component (A) comprises titanium,
Contains magnesium and halogen as essential components. The titanium catalyst component includes various electron donors, metals and elements such as aluminum, silicon, tin, boron, germanium, calcium, zinc, phosphorus, vanadium, and manganese, and alkoxy groups, allyloxyl groups, and acyloxyl groups. It may further contain a functional group or the like. These are obtained by reacting a magnesium compound (or magnesium metal) and a titanium compound, for example, directly or in the presence of one or more electron donors and compounds of the other metals and elements, or It can be obtained by preliminarily treating with one or more compounds of the other metals and elements and then reacting.

The halogen / titanium atomic ratio contained in the component is preferably more than about 4, and the magnesium / titanium atomic ratio is preferably about 2 or more, especially about 3 to about 50.

In such a titanium catalyst component (A), the titanium compound is not substantially eliminated by a simple means such as hexane washing at room temperature. Although the chemical structure is unknown, it is considered that the magnesium atom and the titanium atom are tightly bonded by sharing a halogen. The titanium catalyst component may also be an organic or inorganic inert diluent such as LiCl, CaCO3, BaCl2, Na2CO3, SrCl2, B2O.
3, NaSO4, Al2O3, SiO2, NaB4O7, CO3 (PO4) 2, CaSO4, A
It may contain l2 (SO4) 3, CaCl2, ZnCl2, polyethylene, polypropylene, polystyrene and the like.

Good solid titanium catalyst components have a halogen / titanium (atomic ratio) of more than about 4, preferably about 6 to about 100, and a magnesium / titanium (atomic ratio) of about 2 or more, preferably about 3 to about In those containing about 50, an electron donor, the electron donor / titanium (molar ratio to 1 gram atom of titanium) is about 10 or less, preferably about 6 or less, for example, about 0.2 to about 6, Its specific surface area is about 40 m2 / g or more, more preferably 100 to about 800 m2 / g. Further, whether or not the X-ray spectrum of the titanium catalyst component is amorphous regardless of the starting magnesium compound,
Or, it is desirable that it is in a very amorphous state as compared with that of a general commercial product of magnesium dihalide.

The electron donor which may be contained in the titanium catalyst component includes, for example, organic acid esters, acid halides,
Examples include acid anhydrides, acid amides, tertiary amines, silicates, phosphates, phosphites, ethers and the like.

Many of these titanium catalyst components have already been proposed and widely known. Some examples of the manufacturing method are described below. (1) Pretreatment of an oxygen-containing magnesium compound or a complex compound of a magnesium compound and an electron donor with a reaction aid such as an electron donor and / or an organoaluminum compound or a halogen-containing silicon compound, or without pretreatment , A titanium halide compound forming a liquid phase under the reaction conditions,
Preferably, it is reacted with titanium tetrachloride. (2) A liquid titanium compound having no reducing ability is reacted with a liquid titanium compound in the presence or absence of an electron donor to precipitate a solid titanium catalyst component. (3) A titanium compound is further reacted with the compound obtained in the above (2). (4) An electron donor and a titanium compound are further reacted with those obtained in the above (1) and (2). (5) An electron donor, a titanium compound and an organoaluminum compound are further reacted with those obtained in the above (1) and (2).

In the embodiment of the present invention, the magnesium compound used for the preparation of the titanium catalyst component (A) includes magnesium oxide, magnesium hydroxide, hydrotalcite, magnesium carboxylate, alkoxylate manufactured by various methods. Magnesium, allyloxymagnesium, alkoxymagnesium halide, allyloxymagnesium halide, magnesium dihalide, etc.
Alternatively, a reaction product of an organomagnesium compound with silanol, siloxane, or the like can be exemplified.

The organoaluminum compound that can be used for preparing the titanium catalyst component (A) can be appropriately selected from the following organoaluminum compounds that can be used for olefin polymerization. Furthermore, examples of the halogen-containing silicon compound that can be used for the preparation of the titanium catalyst component (A) include silicon tetrahalide, silicon alkoxyhalide, silicon alkylhalide, and halopolysiloxane.

Examples of the titanium compound used for preparing the titanium catalyst component (A) include titanium tetrahalide,
Examples include alkoxytitanium halide, allyloxytitanium halide, alkoxytitanium, allyloxytitanium and the like, and particularly preferred are titanium tetrahalides, especially titanium tetrachloride.

Examples of the electron donor that can be used for producing the titanium catalyst component (A) include oxygen-containing electron donors such as alcohols, phenols, ketones, aldehydes, carboxylic acids, esters, ethers, acid amides, and acid anhydrides. And nitrogen-containing electron donors such as ammonia, amine, nitrile and isocyanate.

As the organoaluminum compound catalyst component (B), a compound having at least one Al-carbon bond in the molecule can be used, and examples thereof include the following (i) and (ii). (I) an organoaluminum compound represented by the general formula R1mAl (OR2) nHpXq, wherein R1 and R2 each usually have 1 to 15 carbon atoms,
It is preferably a hydrocarbon group containing 1 to 4 groups, which may be the same or different. X is halogen, m is 0 <m ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is 0
≤q <3, and m + n + p + q = 3. (Ii) A complex alkylated product of a Group I metal and aluminum represented by the general formula M1AlR14, wherein M1 is Li, Na, K, and R1 is the same as described above.

The following are examples of the organoaluminum compound belonging to the above formula (i). General formula R1mAl (OR2) 3-m where R1 and R2 are the same as above. m is preferably 1.5 ≦ m
≦ 3. General formula R1mAlX3-m where R1 is the same as described above. X is halogen, and m is preferably 0 <m <3. General formula R1mAlH3-m where R1 is the same as above, and m preferably satisfies 2 ≦ m <3. General formula R1mAl (OR2) nXq where R1 and R2 are the same as above, X is halogen, 0 <m
≦ 3, 0 ≦ n <3, 0 ≦ q <3, and m + n + q = 3. In the aluminum compound belonging to (i), more specifically, trialkylaluminum such as triethylaluminum and tributylaluminum; trialkenylaluminum such as triisoprenylaluminum; dialkylaluminum alkoxide such as diethylaluminum ethoxide and dibutylaluminum butoxide; In addition to alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide, alkylaluminum partially alkoxylated with an average composition represented by the general formula R12.5Al (OR2) 0.5; diethylaluminum Dialkylaluminum halides such as chloride, dibutylaluminum chloride and diethylaluminum bromide; Partially halogenated alkyl aluminum sesquihalides such as minium sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquibromide; alkyl aluminum dihalides such as ethyl aluminum dichloride, propyl aluminum dichloride, butyl aluminum dibromide Alkyl aluminum; dialkyl aluminum hydride such as diethyl aluminum hydride and dibutyl aluminum hydride; partially hydrogenated alkyl aluminum such as alkyl aluminum dihydride such as ethyl aluminum dihydride and propyl aluminum dihydride; ethyl aluminum ethoxy cyclolide Butoxycyclolide, ethyl aluminum ethoxy bromide It is a partially alkoxylated and halogenated alkylaluminum.

The compound similar to (i) may be an organic aluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom.

As such a compound, for example, (C2H
5) 2Al-O-Al- (C2H5) 2, (C4H9) 2Al-O-Al- (C4H9) 2, (C2H
5) 2AlN (C6H5) Al (C2H5) 2 can be exemplified.

As the compound belonging to the above (ii), Li
Al (C2H5) 4, LiAl (C7H15) 4 and the like can be exemplified. Among these, it is particularly preferable to use a trialkylaluminum or a mixture of a trialkylaluminum and an alkylaluminum halide.

Preferably, the highly active titanium catalyst component (A)
And the organoaluminum compound catalyst component (B) are brought into contact in a readily volatile liquid hydrocarbon. The amount of the organoaluminum compound catalyst component (B) can be appropriately selected,
The ratio of aluminum atoms is preferably about 1 to about 1000 g atoms, particularly about 5 to about 100 g atoms, per g atom of titanium in the titanium catalyst component (A). The concentration of the titanium catalyst component (A) in the volatile liquid hydrocarbon is about 0.01 to about 10 mg atom / l, particularly about 0.05 to about 1 mg atom / l in terms of titanium atom. Is advantageous. The temperature of the contact between the two is arbitrary as long as the volatile volatile liquid hydrocarbon is kept in a liquid state, but it is about -20 ° C to about 100 ° C, particularly about 60 ° C.
A range of about ° C is preferable.

When the amount of the organoaluminum compound catalyst component (B) is excessively large with respect to the amount of the titanium catalyst component (A), for example, when Al / Ti (atomic ratio) exceeds 10. If the two components are mixed at once, the catalyst components may be adversely affected. First, a part of the organoaluminum compound catalyst component (B) and the titanium catalyst component (A) are mixed, for example, with an Al / Ti (atomic ratio). ) Is mixed at a ratio of 10 or less, and then the remaining organoaluminum compound catalyst component (B) is mixed, and a multistage mixing method is preferably employed. In this case, in order to prevent the catalyst from deteriorating with time, it is desirable that, after mixing all the organoaluminum compound catalyst components (B), the volatile volatile hydrocarbon is immediately vaporized and subjected to polymerization. .

When the catalyst components (A) and (B) are brought into contact with each other, a small amount of the catalyst component may be added at any time after the catalyst process and before the vaporization of the volatile hydrocarbon in the process. Preliminary polymerization of the small amount of olefins may be carried out in the presence of olefins. The olefins may be the same or different from those used for polymerization.

The amount to be prepolymerized is about 1000 g or less, particularly about 1 to about 200 g, per milligram atom of titanium, and is about 1/10 or less, particularly about 1 / l of the amount to be polymerized by gas phase polymerization. It is better to keep it below 50.

The readily volatile liquid hydrocarbons are easily vaporized by heating, and for example, hydrocarbons having 3 or 4 carbon atoms such as propane and butane are most preferable. However, hydrocarbons having about 5 to 6 carbon atoms can also be used. These can be used alone or in combination of two or more.

Next, the metallocene type catalyst will be described.

The solid group IVB metallocene catalyst used in the present invention comprises [A] a group IVB transition metal compound containing a ligand having a cyclopentadienyl skeleton, [B] an organoaluminum oxy compound, C] particulate carrier. [A] Group IVB transition metal compound containing a ligand having a cyclopentadienyl skeleton used in the present invention (hereinafter sometimes referred to as metallocene compound [A]).
Is represented by the following formula [I]. MLx ... [I] [wherein M is a group IVB transition metal atom, specifically, zirconium, titanium or hafnium;
Is a ligand that coordinates to the transition metal atom, and at least one
L is a ligand containing a ligand having a cyclopentadienyl skeleton, and L other than a ligand containing a ligand having a cyclopentadienyl skeleton is a hydrocarbon having 1 to 12 carbon atoms Group, alkoxy group, aryloxy group, trialkylsilyl group, SO3R3 group (where R3 is a hydrocarbon group having 1 to 8 carbon atoms which may have a substituent such as halogen), a halogen atom or a hydrogen atom, x is the valence of the transition metal atom. Examples of the ligand including a ligand having a cyclopentadienyl skeleton include cyclopentadienyl group, methylcyclopentadienyl group, dimethylcyclopentadienyl group, trimethylcyclopentadienyl group, and tetramethyl Cyclopentadienyl group, pentamethylcyclopentadienyl group, ethylcyclopentadienyl group, methylethylcyclopentadienyl group, propylcyclopentadienyl group, methylpropylcyclopentadienyl group, butylcyclopentadienyl group And alkyl-substituted cyclopentadienyl groups such as methylbutylcyclopentadienyl group and hexylcyclopentadienyl group, indenyl group, 4,5,6,7-tetrahydroindenyl group, fluorenyl group and the like. . These groups may be substituted with a halogen atom, a trialkylsilyl group or the like.

Among the ligands which coordinate to these transition metal atoms, an alkyl-substituted cyclopentadienyl group is particularly preferred.

When the compound represented by the above general formula [I] contains two or more groups having a cyclopentadienyl skeleton, two of the groups having a cyclopentadienyl skeleton are ethylene, propylene Alkylene groups such as
The bond may be formed via a substituted alkylene group such as isopropylidene or diphenylmethylene, or a substituted silylene group such as a silylene group or a dimethylsilylene group, a diphenylsilylene group, or a methylphenylsilylene group.

Specific examples of the ligand L other than the ligand having a cyclopentadienyl skeleton include the following.

Examples of the hydrocarbon group having 1 to 12 carbon atoms include an alkyl group, a cycloalkyl group, an aryl group and an aralkyl group. More specifically, the alkyl group includes a methyl group, an ethyl group and a propyl group. Group, isopropyl group, butyl group and the like. Examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group. Examples of the aryl group include a phenyl group and a tolyl group, and examples of the aralkyl group include a benzyl group and a neophyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group and a butoxy group, and examples of the aryloxy group include a phenoxy group. Examples of the halogen include fluorine, chlorine, bromine, and iodine.

Examples of the ligand represented by SO 3 R 3 include a p-toluenesulfonato group, a methanesulfonato group and a trifluoromethanesulfonato group.

The metallocene compound [A] containing such a ligand having a cyclopentadienyl skeleton has, for example, the case where the valence of the transition metal atom is 4, more specifically the following formula [I ']. Is shown. R4aR5bR6cR7dM [I '] In the formula [I'], M is the same transition metal atom as in the formula [I], R4 is a group (ligand) having a cyclopentadienyl skeleton, and R5, R6 and R7 Is a group having a cyclopentadienyl skeleton, an alkyl group, a cycloalkyl group,
Aryl, aralkyl, alkoxy, aryloxy, trialkylsilyl, SO3R3, halogen or hydrogen. A is an integer of 1 or more, and a + b + c + d = 4.

In the above formula [I '], R4, R5, R6
And at least two of R7, for example R4 and R7
Metallocene compounds in which 5 is a group (ligand) having a cyclopentadienyl skeleton are preferably used.

These groups having a cyclopentadienyl skeleton include alkylene groups such as ethylene and propylene, substituted alkylene groups such as isopropylidene and diphenylmethylene, and silylene groups or substituted groups such as dimethylsilylene, diphenylsilylene and methylphenylsilylene groups. They may be bonded via a silylene group or the like.

R6 and R7 are a group having a cyclopentadienyl skeleton, an alkyl group, a cycloalkyl group,
Aryl, aralkyl, alkoxy, aryloxy, trialkylsilyl, SO3R3, halogen or hydrogen.

Hereinafter, a plurality of specific examples of metallocene compounds in which M is zirconium will be described.

Bis (indenyl) zirconium dichloride, bis (indenyl) zirconium dibromide, bis (indenyl) zirconiumbis (p-toluenesulfonato) bis (4,5,6,7-tetrahydroindenyl) zirconium dichloride, bis ( Fluorenyl) zirconium dichloride, ethylene bis (indenyl) zirconium dichloride, ethylene bis (indenyl) zirconium dibromide, ethylene bis (indenyl) dimethyl zirconium, ethylene bis (indenyl) diphenyl zirconium, ethylene bis (indenyl) methyl zirconium monochloride, ethylene bis (Indenyl) zirconium bis (methanesulfonato), ethylenebis (indenyl) zirconiumbis (p-toluenesulfonato), ethylenebis (indenyl) ) Zirconium bis (trifluoromethanesulfonato), ethylenebis (4,5,6,7-tetrahydroindenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-fluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-methyl) (Cyclopentadienyl) zirconium dichloride, dimethylsilylenebis (cyclopentadienyl) zirconium dichloride, dimethylsilylenebis (methylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (dimethylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis ( Trimethylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (indenyl) zirconium dichloride, dimethylsilylenebis (a (Denyl) zirconium bis (trifluoromethanesulfonato), dimethylsilylenebis (4,5,6,7-tetrahydroindenyl) zirconium dichloride, dimethylsilylene (cyclopentadienyl-fluorenyl) zirconium dichloride, diphenylsilylenebis (indenyl) zirconium Dichloride, methylphenylsilylene bis (indenyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dibromide, bis (cyclopentadienyl) methylzirconium monochloride, bis (cyclopentadiene) (Enyl) ethyl zirconium monochloride, bis (cyclopentadienyl) cyclohexyl zirconium monochloride, bis (cyclopentadienyl) phenyldi Conium monochloride, bis (cyclopentadienyl) benzylzirconium monochloride, bis (cyclopentadienyl) zirconium monochloride monohydride, bis (cyclopentadienyl) methylzirconium monohydride, bis (cyclopentadienyl) dimethyl Zirconium, bis (cyclopentadienyl) diphenylzirconium, bis (cyclopentadienyl) dibenzylzirconium, bis (cyclopentadienyl) zirconium methoxychloride, bis (cyclopentadienyl) zirconium ethoxycyclolide, bis (cyclopentadiene Enyl) zirconium bis (methanesulfonato), bis (cyclopentadienyl) zirconium bis (p-toluenesulfonato),
Bis (cyclopentadienyl) zirconium bis (trifluoromethanesulfonato), bis (methylcyclopentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium dichloride, bis (dimethylcyclopentadienyl) zirconium ethoxycyclolide Bis (dimethylcyclopentadienyl) zirconium bis (trifluoromethanesulfonato), bis (ethylcyclopentadienyl) zirconium dichloride, bis (methylethylcyclopentadienyl) zirconium dichloride, bis (propylcyclopentadienyl) zirconium dichloride , Bis (methylpropylcyclopentadienyl) zirconium dichloride, bis (butylcyclopentadienyl) zirconium dichloride, bis (methyl Tylcyclopentadienyl) zirconium dichloride, bis (methylbutylcyclopentadienyl) zirconium bis (methanesulfonato), bis (trimethylcyclopentadienyl) zirconium dichloride, bis (tetramethylcyclopentadienyl) zirconium dichloride, bis (Pentamethylcyclopentadienyl) zirconium dichloride, bis (hexylcyclopentadienyl) zirconium dichloride, bis (trimethylsilylcyclopentadienyl) zirconium dichloride.

In the above examples, disubstituted cyclopentadienyl ring includes 1,2- and 1,3-substituted, and trisubstituted 1,2-, 3- and 1,2,4- Including substitutions. Alkyl groups such as propyl and butyl are n-, i-, sec-, tert-
And isomers.

As the metallocene compound [A], a compound in which zirconium in the above zirconium compound is replaced with titanium or hafnium can also be used.

These compounds may be used alone,
Two or more kinds may be used in combination. It may be used after being diluted with a hydrocarbon or a halogenated hydrocarbon.
In the embodiment of the present invention, a zirconocene compound in which the central metal atom is zirconium and which has a ligand having at least two cyclopentadienyl skeletons is preferably used as the metallocene compound [A].

Specific examples of the organic aluminum oxy compound [B] include conventionally known aluminoxanes and benzene-insoluble aluminum oxy compounds as disclosed in JP-A-2-276807.

Such a conventionally known aluminoxane can be produced from the [B-2] organoaluminum compound described later, for example, by the following method. (1) Compounds containing water of adsorption or salts containing water of crystallization such as hydrated magnesium chloride, hydrated copper sulfate, hydrated aluminum sulfate, hydrated nickel sulfate, hydrated cerous chloride In a suspended hydrocarbon medium,
A method in which an organoaluminum compound such as trialkylaluminum is added and reacted to recover as a hydrocarbon solution. (2) A method in which water (ice or water vapor other than water) is directly applied to an organoaluminum compound such as trialkylaluminum in a medium such as benzene, toluene, ethyl ether, or tetrahydrofuran to recover a solution of the medium. (3) A method of reacting an organoaluminum compound such as trialkylaluminum with an organotin oxide such as dimethyltin oxide or dibutyltin oxide in a medium such as decane, benzene or toluene.

The solvent or the unreacted organoaluminum compound may be removed from the recovered aluminoxane solution by distillation, and then redissolved in the solvent.

[B] The organoaluminum oxy compound is
A small amount of metal components other than aluminum may be contained.

The above [B] organoaluminum oxy compound is generally used in an amount of 5 to 1000 mol, preferably 10 to 400 mol, per 1 mol of the solid metallocene catalyst (in terms of transition metal atom). It is desirable.

Specific examples of the particulate carrier [C] include S
iO2, Al2O3, B2O3, MgO, ZrO2, CaO, Ti
Inorganic carriers such as O2, ZnO, Zn2O, SnO2, BaO, and ThO, and resins such as polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, and styrene-divinylbenzene copolymer can be used. . Of these resins, SiO2 is preferred. Further, these resins can be used in combination of two or more kinds.

The solid group IVB metallocene catalyst is formed by loading the above-mentioned [A] metallocene compound and [B] organoaluminum oxy compound on the [C] particulate carrier by a conventionally known method.

The solid group IVB metallocene catalyst is
Along with [A] a metallocene compound and [B] an organoaluminum oxy compound, the following [B-2] organoaluminum compound may be supported on a [C] particulate carrier.

In preparing the solid group IVB metallocene catalyst, the metallocene compound (A) (in terms of transition metal atom) is usually added in an amount of 0.001 to 1 g of the particulate carrier (C).
The amount of the organoaluminum oxy compound [B] is usually 0.1 to 100 mmol, preferably 0.5 to 20 mmol, in an amount of 1.0 mmol, preferably 0.01 to 0.5 mmol.

The solid metallocene catalyst particles used have a particle size of 1 to 300 μm, preferably 10 to 100 μm.
m is desirable.

Further, the solid metallocene-based catalyst may contain other components useful for olefin polymerization, such as an electron donor and a reaction aid, if necessary, in addition to the above-mentioned catalyst components.

The solid metallocene catalyst may be such that an olefin is prepolymerized on the solid metallocene catalyst as described above.

The solid group IVB metallocene catalyst can (co) polymerize an olefin with excellent polymerization activity.

The olefin is polymerized using the solid metallocene catalyst as described above. At the time of polymerization, the following [B-2] organoaluminum compound is used together with the solid IVB metallocene catalyst. It can also be used.

[B-2] The organoaluminum compound used as an organoaluminum compound, and also used in producing the above-mentioned [B] aluminoxane solution, specifically includes trimethylaluminum, Triethylaluminum, tripropylaluminum, triisopropylaluminum, trin-butylaluminum, triisobutylaluminum, trisec-butylaluminum, tritert-butylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, tridecylaluminum Trialkyl aluminum such as cyclohexyl aluminum and tricyclooctyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, diethyl aluminum bromide Dialkylaluminum halides such as diisobutylaluminum chloride; dialkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride; dialkylaluminum alkoxides such as dimethylaluminum methoxide and diethylaluminum ethoxide; and dialkylaluminum aryloxides such as diethylaluminum phenoxide. Can be

Of these, preferred are trialkylaluminums, and particularly preferred are triethylaluminum and triisobutylaluminum.

As the organoaluminum compound, isoprenylaluminum represented by the following general formula can also be used. (i-C4H9) wAly (C5H10) z where w, y, and z are positive numbers and z ≧ 2w.

These listed organoaluminum compounds may be used in combination of two or more.

[B-2] The organoaluminum compound may contain a small amount of a metal component other than aluminum.

When the above [B-2] organoaluminum compound is separately supplied to the reaction system from the solid metallocene catalyst, it is usually added to 1 mol of the solid metallocene catalyst (in terms of transition metal atom). It is desirable to use it in an amount of 1 to 1000 mol, preferably 2 to 300 mol.

When the organic aluminum compound [B-2] is supported on the particulate support [C] together with the metallocene compound [A] and the organic aluminum oxy compound [B], a solid metallocene catalyst (transition metal atom) is used. It is used in an amount of usually 1 to 200 mol, preferably 2 to 300 mol, per 1 mol of (conversion).

[0118]

According to the gas velocity control method of the present invention, the circulation gas flow rate is measured using an ultrasonic flowmeter, and the velocity of the circulation gas discharged from the gas phase polymerization reactor is controlled based on the measurement result. Thereby, the effect of controlling with a simple and inexpensive device is exhibited. In addition, the gas containing fine particles, particularly the particles are active, and the gas containing the particles themselves is a compound that reacts with the particles. It is possible to effectively control while.

Further, since the measurement is performed by using ultrasonic waves, the volume velocity of the gas can be directly measured.

Further, it is possible to omit a calculation step required for controlling the amount of circulating gas, and control can be performed more simply and accurately.

Furthermore, by using an ultrasonic flowmeter, even if fine particles such as polymer particles are present, they are not clogged in the flow rate measuring section. Accurate and long-term stable measurement is possible.

Since almost no differential pressure is generated, the power does not need to be increased. Further, even if the pipe diameter becomes large, the above-described effects can be obtained without increasing the size and cost of the flow rate measuring device.

In the gas phase polymerization method according to the present invention, a fluidized bed region in a stable state can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a gas phase polymerization apparatus according to an embodiment.

Fig. 2 Diagram of ultrasonic flow meter measurement principle

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polymerizer 1a Straight body part 2 Gas dispersion plate 3 Fluidized bed area 4 Gas introduction area 5 Catalyst supply pipe 6 Pipe for taking out produced polymer 7 Reduction area 8 Gas circulation pipe 9 Gas supply pipe 10 Heat exchanger 11 Outlet 12 Blower 13 Ultrasonic flow meter S1 Forward ultrasonic transmitter S2 Reverse ultrasonic transmitter J1 Forward ultrasonic receiver J2 Reverse ultrasonic receiver V Fluid flow direction

Continued on the front page (72) Inventor Ryoichi Yamamoto 3 Chigusa Coast, Ichihara City, Chiba Prefecture Mitsui Chemicals Co., Ltd. (72) Inventor Kenji Doi 3 Chigusa Coast, Ichihara City, Chiba Prefecture Mitsui Chemicals Inc.

Claims (7)

[Claims] 1. An olefin polymerization equipment using a fluidized-bed gas-phase polymerization reactor for performing a gas-phase polymerization using a solid catalyst component, and an olefin polymerization equipment taken out of a reduction zone located above the fluidized-bed gas-phase polymerization reactor. Of the polymerization component-containing gas into the fluidized-bed gas-phase polymerization reactor 1
And a circulation line for supplying the olefin to the fluidized-bed gas-phase polymerization reactor. An ultrasonic flowmeter is provided on the circulation line, and a flow rate of the circulating gas of the polymerization component-containing gas is measured by the ultrasonic flowmeter. Controlling the gas velocity of the gas stream forming the gas flow. 2. A flowmeter is further provided in the supply line to measure a flow rate of newly supplied olefin, and based on a value obtained by adding the flow rate to the measurement result of the circulating gas flow rate, the fluidized bed is provided. 2. The method according to claim 1, further comprising controlling a gas velocity of a gas stream forming a fluidized bed in the gas-phase polymerization reactor. 3. The temperature and pressure inside the fluidized bed area are measured, and the flow rate of the circulating gas, the flow rate of the newly supplied olefin, the temperature, the pressure, and the fluidized bed measured by an ultrasonic flowmeter. The gas velocity inside the fluidized bed area is calculated based on the sectional area of the fluidized bed area, and a deviation from the calculated gas velocity and a gas velocity allowable range, which is one of preset polymerization conditions, is determined. 3. The method according to claim 2, wherein the gas velocity of the gas flow forming the layer zone is controlled. 4. The gas velocity of a gas phase polymerization reactor according to claim 1, wherein the method of controlling the gas velocity of the gas flow forming the fluidized bed zone comprises controlling the volume velocity of the circulating gas. Control method. 5. The gas phase polymerization according to claim 2, wherein a volume velocity of the circulating gas is controlled as a method of controlling a gas velocity of a gas flow forming the fluidized bed region. Method of controlling the gas velocity of the vessel. 6. The gas phase polymerization according to claim 5, wherein the method of controlling the gas velocity of the gas stream forming the fluidized bed zone further comprises controlling the volume velocity of the newly supplied olefin. Method of controlling the gas velocity of the vessel. 7. A gas-phase polymerization method comprising performing gas-phase polymerization of an olefin using the control method according to claim 1, 2, 3, 4, 5, or 6.