JP2000159817A - Production of olefin polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing an olefin polymer which can efficiently produce an olefin polymer having target properties by measuring the properties of a polymer in parallel with the polymerization of an olefin and feed backing the obtained measurement results into the polymerization conditions. SOLUTION: A process for producing an olefin polymer comprise (a) feeding an olefin, hydrogen, a transition metal catalyst component, a cocatalyst, and, if necessary, an electron donor compound to a polymerization vessel to continuously effect polymerization, (b) taking the polymer obtained in the step (a) out of the polymerization vessel, (c) drying and/or granulating the olefin polymer obtained in the step (b), (d) continuously or intermittently sampling the olefin polymer obtained in the step (c), (e) measuring the sample obtained in the step (d) by pulse nuclear magnetic resonance to obtain the measured value of the property to be controlled, and (f) comparing the measured value of the property obtained in the step (e) with the target value of the property to judge, based on the resulting comparative results, to judge whether or not the polymerization conditions capable of controlling the property should be changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an olefin polymer. More specifically, the present invention relates to a method for continuously producing an olefin polymer while controlling physical properties using a pulse nuclear magnetic resonance measurement apparatus.

[0002]

2. Description of the Related Art Polyolefins are widely used because of their excellent balance of physical properties, moldability and price. For example, homopolymers that are homopolymers of propylene, random copolymers that are copolymers of propylene and a small amount of ethylene, and block copolymers that are a reactor blend of a homopolymer of propylene and EPR are included. Are widely used according to their respective characteristics.

[0003] The physical properties of these propylene polymers vary depending on a number of factors, but one of the most important physical properties to be controlled in production is that the homopolymer has a xylene solubles content of 23 ° C contained in the polymer. The content (hereinafter sometimes referred to as CXS), the comonomer content in a random copolymer, and the rubbery polymer content in a block copolymer can be mentioned.

When controlling these physical property values in a continuous process, first, polymerization conditions that can control these physical property values are determined based on experimental data in a laboratory or a pilot plant and actual data in the process. Is common. Then, the actual operation of the process is started, and the produced polymer is sampled from the process to measure physical property values to be controlled. Here, if there is a difference between the measured value and the target value, in order to correct the difference, the polymerization conditions for controlling these physical property values are adjusted and the physical properties of the polymer are corrected so as to approach the target value.

The problem here is that it generally takes a considerable amount of time to measure the physical properties to be controlled. For example, when measuring CXS of a homopolymer, the following method is usually employed. That is, (1) dissolving a predetermined amount of the homopolymer in xylene at a high temperature, (2) cooling the obtained solution to 23 ° C.,
(3) separating the precipitated propylene polymer by filtration,
(3) The weight of the propylene polymer contained in the filtrate or the weight of the precipitated propylene polymer obtained by filtration is determined to obtain CXS. This method is a method of directly determining the CXS, but according to this method, it generally takes 3 to 4 hours, and sometimes more time to obtain the CXS.

However, considering the recent increase in the size of the process, if CXS deviates from the target value, the production loss for several hours required for the measurement cannot be overlooked. Although there are differences in the method of obtaining the measured value and the time until the measured value is obtained, the above-mentioned situation is the same for the comonomer content in the random copolymer and the rubbery polymer content in the block copolymer.

Another problem is that a desired property value may not be obtained under the assumed conditions due to some unexpected disturbance. For example, one method of controlling the CXS of a homopolymer is to control the amount of an electron donor supplied to a polymerization tank. In general, given other conditions are constant, the CXS of the homopolymer is:
It is a function of the electron donor supply. However, when an unexpected disturbance occurs in which the amount of the electron donor fluctuates due to, for example, a component contained as an impurity in the raw material propylene, CXS may cause an unexpected fluctuation. In this case, the obtained CXS value is compared with the target CXS value, and based on the difference, for example, the amount of the electron donor supplied to the polymerization tank is changed, and other conditions are also changed in some cases. Need arises. Also in this case, it is needless to say that it is important to detect the change in the physical property value due to the disturbance as soon as possible and feed it back to the polymerization conditions.

In the prior art, Japanese Patent Application Laid-Open No. 9-7160
5 discloses means for using a nuclear magnetic resonance spectrum, in particular, pulsed nuclear magnetic resonance (hereinafter sometimes referred to as pulsed NMR) (JP-A-9-7160).
5). According to the published patent, pulse NMR is used to quickly measure MI, molecular weight, softening point, monomer composition, polar group content, composition distribution, solvent-soluble component amount, inorganic content in polymer, density, etc. It shows that you can do it.

[0009] Incidentally, the patent discloses that the sample to be measured must be immediately after polymerization. Here, “immediately after polymerization” refers to a state in which the physical properties of the reaction product have not changed from the physical properties at the end of the polymerization, such as removal of the solvent or processing of the thermoplastic resin (processing refers to granulation of the thermoplastic resin). (Including the subsequent processing into pellets) is not performed.

However, according to the study of the present inventors, a sample immediately after polymerization based on the above definition is subjected to pulse N
When used for MR measurement, accurate values may not be obtained. In pulse NMR, generally, the sum of signals emitted from components having different relaxation times contained in a polymer is defined as FI
It is recorded as D, but when the removal of the solvent is insufficient,
It can be considered that a signal from a solvent having a low molecular weight and a short relaxation time adversely affects the measurement. According to our studies, such adverse effects can be avoided by drying before measuring the pulse NMR and / or by measuring the sample after granulation.

[0011] In addition, poorly dried polymers generally have poor particle fluidity as compared to sufficiently dried polymers. In order to quickly reflect the pulse NMR measurement results in the operating conditions, the pulse NMR measurement must be performed online, that is, the sample is automatically sampled from the polymer manufacturing process, and the pulse NMR measurement is automatically performed. It is preferably performed. However, if the particle fluidity of the polymer deteriorates, there are many cases where trouble occurs in this automatic sampling. Such problems can generally be avoided by drying to maintain good particle flow.

Further, in the description of the patent, polyethylene, polypropylene,
Examples thereof include polybutene, polyhexenes, poly-4-methyl-1-pentene and copolymers thereof, and the physical properties include MI, molecular weight, softening point, monomer composition, polar group content, composition distribution, and solvent soluble component amount. , Inorganic content in polymer, density and the like. However, in the examples, the resin to be measured is only polyethylene and a polyethylene copolymer, and there is no disclosure of an application example to polypropylene. Further, as physical properties to be controlled, only MI and density are described, and CXS,
There is no teaching on application to comonomer content or rubbery polymer content.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a propylene polymer, that is, a homopolymer, a random copolymer,
In the block copolymer, CXS,
An olefin polymer capable of efficiently producing an olefin polymer having desired physical properties by quickly and accurately measuring the ethylene content or the rubbery polymer content and feeding back the obtained measurement results to the polymerization conditions. It is intended to provide a manufacturing method.

[0014]

Means for Solving the Problems The present invention has been made as a result of intensive studies to achieve the above object and provides a method for producing an olefin polymer including the following steps (a) to (f). Things. (A) a step of supplying an olefin, hydrogen, a transition metal catalyst component, a cocatalyst, and, if necessary, an electron-donating compound to a polymerization tank to continuously polymerize the olefin, and (b) a step obtained in the step (a). Removing the olefin polymer obtained from the polymerization tank, (c) drying and / or granulating the olefin polymer obtained in step (b), and (d) olefin obtained in step (c). (E) continuously or intermittently sampling the polymer, (e) measuring the sample obtained in step (d) using pulsed nuclear magnetic resonance to obtain measured values of physical properties to be controlled, (f) A) comparing the measured values of the physical properties determined in the step (e) with target values, and determining whether to change polymerization conditions capable of controlling the physical properties based on the obtained comparison results;

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, polymerization of an olefin is carried out continuously. (Olefin polymer) The olefin polymer produced by the production method of the present invention is an olefin polymer mainly composed of ethylene and propylene, and contains a copolymer. As the comonomer used for copolymerization, ethylene,
Including propylene, 1-butene, 1-pentene, 1-hexene, 1-octene and the like. Among them, preferred are propylene-based polymers mainly composed of propylene, and more preferred are so-called random copolymers, which are homopolymers of propylene homopolymers and copolymers of propylene and a small amount of ethylene. It is a so-called block copolymer which is a reactor blend of a propylene homopolymer and an ethylene / propylene copolymer. The MFR, the copolymerization amount, and the ethylene / propylene copolymer content of these polymers are not particularly limited.

(Polymerization Step) In the step (a) of the present invention, olefin, hydrogen, a transition metal catalyst component, an organoaluminum compound, and if necessary, an electron-donating compound are supplied to a polymerization tank to carry out polymerization of the olefin. This is a process that is performed continuously. As the polymerization tank, any conventionally known polymerization tank can be used. That is, a tank-type polymerization tank, a loop-type polymerization tank, or the like can be used. The polymerization tanks may be used alone, or in series or in parallel. further,
A polymerization tank and a classifier may be used in combination. The type of polymerization is also optional. That is, a so-called slurry polymerization using an inert solvent as a medium, a so-called bulk polymerization using a monomer itself as a medium, a so-called solution polymerization in which a generated polymer itself is melted in a medium, and a so-called polymerization performed in a gaseous medium. Gas phase polymerization is possible. In the case of performing gas phase polymerization, polymerization in a so-called supercondensed mode, in which a liquid inert hydrocarbon medium is supplied to increase the heat removal efficiency, is also possible.

Examples of the olefin to be supplied to the polymerization tank include ethylene, propylene, 1-butene, 1-pentene, hexene and octene. In addition, you may use these mixtures. Further, it may contain an inert hydrocarbon compound such as methane, ethane, and propane. The olefin is usually used after being purified by dehydration using a molecular sieve or the like before being supplied to the polymerization tank.

In the present invention, hydrogen is used to control the molecular weight of the olefin polymer. Hydrogen is also subjected to purification such as dehydration and deoxygenation before being supplied to the polymerization tank. There is no particular limitation on the supply amount of hydrogen, and it is sufficient to supply an amount of hydrogen necessary to obtain a desired molecular weight according to the properties of the catalyst described later. It is preferable to control the amount of supplied hydrogen by using both an actually measured value of the hydrogen supply rate by a flow meter and an actually measured value of the hydrogen concentration in the polymerization tank by a process gas chromatograph (hereinafter abbreviated as PGC).

The catalyst used in the present invention is formed from a transition metal catalyst component, a cocatalyst, and, if necessary, an electron donating compound. Note that “formed” does not exclude the presence of other arbitrary components, and other components can be added according to a desired purpose. As the transition metal catalyst component, TiCl ₃ , a titanium catalyst component supported on a magnesium compound, a titanium catalyst component supported on a carrier such as silica or a polymer, a metallocene, a metallocene supported on a carrier, and the like can be used. Note that a mixture of these transition metal components may be used. It is preferred that the olefin is preliminarily polymerized before supplying these catalysts to the polymerization tank. As the polymerization amount, the transition metal catalyst component 1
About 0.1 to 100 g per g is preferable.

Examples of the monomers used for the preliminary polymerization include ethylene, propylene, 1-butene, 1-pentene, hexene, octene and the like, but are not limited thereto. These monomers may be a mixture. Further, it may be the same as or different from the monomer used for the polymerization in the polymerization tank. In addition, hydrogen may be allowed to coexist during the preliminary polymerization. When supplying the transition metal catalyst component to the polymerization tank, any form can be adopted. That is, an inert hydrocarbon solution may be used, or an inert hydrocarbon slurry may be used. Further, it may be supplied to the polymerization tank in a dry and dry powder state.

As the cocatalyst, an organoaluminum compound is generally used. Specifically, a trialkylaluminum such as triethylaluminum or triisobutylaluminum, or a reaction product thereof with an alcohol can be used. When the transition metal component contains a metallocene, an aluminoxane such as methylaluminoxane or a compound capable of reacting with the metallocene to form an ion pair can be used as a cocatalyst. These cocatalysts may be supplied to the polymerization tank as a solution of an inert hydrocarbon, or may be directly supplied to the polymerization tank without using a solvent.

As the electron donating compound to be used if necessary, a compound containing a hetero atom such as an oxygen atom or a nitrogen atom can be generally mentioned. Especially preferred is
A compound containing an oxygen atom, specifically, an ether compound, an ester compound, and an alkoxide.
In particular, when a titanium catalyst component supported on TiCl ₃ or a magnesium compound is used as the transition metal catalyst component, an electron donating compound is often supplied to the polymerization tank,
Monoesters and alkylalkoxysilanes are preferably used. These electron donating compounds may be used alone or as a mixture. Further, it may be supplied to the polymerization tank as a solution of an inert hydrocarbon, or may be directly supplied to the polymerization tank without using a solvent. Further, at the time of the above-mentioned pre-polymerization, the electron-donating compound may be brought into preliminary contact with the transition metal catalyst component.

In the present invention, the polymerization temperature, polymerization pressure, average residence time and the like are not particularly limited. These can be arbitrarily set depending on the capacity of the process, the performance of the catalyst, economic reasons, and the like. As described above, the polymerization process can take various systems. For example, the apparatus shown in FIG. 1 can be used as a polymerization process of a block copolymer of propylene and ethylene.

In FIG. 1, a liquid-phase polymerization tank 1 with a stirring device is shown.
And a gas phase polymerization tank 8, a classification system including a sedimentation hydraulic classifier 4, a concentrator 3 (liquid cyclone), and a countercurrent pump 13, a double-pipe heat exchanger 5 and a flow flash A degassing system consisting of a tank 6 is incorporated.

The liquid-phase polymerization tank 1 is supplied with liquefied propylene, hydrogen, organoaluminum, a transition metal catalyst component and the like. The polymer polymerized and extracted in the liquid phase polymerization tank 1 is supplied to the upper part of the liquid classifier 4 by the slurry pump 2, and the lower part of the classifier 4 hardly contains the polymer obtained from the concentrator 3. A slurry containing a large amount of small particle size polymer is supplied from the upper portion by supplying a supernatant liquid (liquefied propylene), and a slurry containing a large amount of large particle size polymer that has settled against the upward flow of the solvent is extracted from the lower portion. It is.

The slurry containing a large amount of the small particle size polymer taken out from the upper part of the classifier 4 is sent to the concentrator 3, where it is separated into a concentrated slurry and a supernatant containing less polymer. The supernatant containing less polymer is used as a classification solvent in the classifier 4.

The slurry containing a large amount of the large-diameter polymer extracted from the lower part of the hydraulic classifier 4 is fed to the fluidized flash tank 6 through the double tube heat exchanger 5. In the fluidized flash tank 6, heated propylene gas is fed from the lower part to vaporize liquefied propylene, and the obtained solid polypropylene particles are sent to a gas phase polymerization tank 8, where a rubbery polymer of propylene and ethylene is produced. Polymerization takes place. The block copolymer particles extracted from the lower part of the gas phase polymerization tank 8 are sent to a screw feeder 16 and then sent to a dryer 17 from the screw feeder to be dried.

(Step of Removing Olefin Polymer) Since the present invention is a continuous polymerization, the olefin polymer is continuously or intermittently removed from the polymerization tank at short time intervals. The method of removing the olefin polymer from the polymerization tank is not particularly limited, but generally, a method of removing the olefin polymer using a pressure difference is preferably used. That is, this is a method in which the olefin polymer is taken out by opening the valve through a valve into a vessel having a lower pressure than the polymerization tank. The removal rate of the olefin polymer per unit time can be controlled by the pressure difference between the polymerization tank and the low-pressure vessel and the frequency of opening and closing the valve.

The position at which the olefin polymer is withdrawn from the polymerization line is arbitrary, and is taken from an appropriate place depending on the polymerization process and control purpose. As shown in FIG. 1, when the homopolymerization of propylene is performed in the liquid-phase polymerization tank 1 and the rubbery content is controlled in the process of copolymerizing propylene and ethylene in the gas-phase polymerization tank 8, the rubber is extracted from the polymerization tank. Outlet 19 of dryer 17 from which dried polymer is obtained
In general, when it is desired to obtain a measured value more quickly, the sample can be collected at the outlet of the gas phase polymerization tank 8 and the measurement sample can be dried and / or granulated alone for measurement.

When controlling the CXS of the first-stage polymer, or when controlling the amount of the comonomer by copolymerization with a comonomer in the first-stage polymerization tank, the outlet of the first-stage polymerization tank is controlled. The first stage polymerization tank can be controlled independently by collecting and measuring in the above.

(Drying and / or Granulation Step) In the present invention, the olefin polymer sample to be subjected to pulse NMR is subjected to a drying and / or granulation step before measurement by pulse NMR. Through this step, the pulse N
Accurate measurement by MR becomes possible. Drying can be performed by a conventionally known method. That is, using a dryer such as a paddle dryer or a purge bin, low boiling compounds such as monomers, oligomers and solvents contained in the polymer are removed under a dry inert gas stream such as dry nitrogen. There are no particular restrictions on the drying temperature, drying time, inert gas flow rate, etc.,
Conditions may be set so as to obtain a desired drying level according to the form of the process used for the polymerization. Further, the inert gas may be used in one pass or may be circulated and reused.

The granulation is usually carried out after the above drying step.
This is done by feeding the olefin polymer to the extruder. As the extruder, various extruders such as a known single-screw extruder and a twin-screw extruder can be used. Upon granulation, various additives may be mixed. Further, the peroxide may be supplied to control the molecular weight of the olefin polymer in the extruder. Furthermore, during the granulation step in the extruder, the volatile components may be degassed by a vent line. The temperature during granulation, the residence time of the resin, and the like are not particularly limited, and may be set in consideration of the capacity of the extruder, required physical properties of the grade to be manufactured, economic reasons, and the like.

(Sampling Step) In the present invention, as shown in FIG. 2, all or part of the dried and / or granulated olefin polymer is sampled,
It is subjected to a pulse NMR measurement process. The olefin polymer sampled in this way is pulse NM
Sent to R for measurement. Although the transfer of the sample may be performed manually, in general, pneumatic transportation is used.
Nitrogen gas is preferably used as the gas used for pneumatic transportation, but air may be used if there is no danger such as ignition. The sampling frequency may be continuous or intermittent, and the sampling frequency is determined according to the purpose.

(Pulse NMR measurement step) The olefin polymer transferred to the pulse NMR is pulse NM
It is set at the measurement site of R, and the measurement is performed. When the transfer of the olefin polymer is performed by pneumatic transport, separation of the olefin polymer and the gas used for pneumatic transport is performed in a cyclone installed above the pulse NMR measurement site.

Next, the sample is irradiated with a pulse,
(Free Instruction Decay) sign
al is recorded. At the time of measurement, in order to stabilize the temperature, it is preferable that the sample is preliminarily heated before pulse irradiation, and the measurement is always performed at a constant temperature. There is no limitation on the nuclide to be measured, but proton is preferable in order to obtain a measurement result in a short time.

The pulse NMR is a device for irradiating a sample with a pulse of a radio wave and measuring the time change of the magnetic moment intensity of the sample. Generally, the CXS, comonomer content or rubbery polymer content is measured. . Hereinafter, an example of the principle of measurement of CXS by pulse NMR will be described. Note that the principle of measurement of CXS by pulse NMR is not limited to one, and any one can be used as long as it meets the purpose. The same applies to the principle of measuring the comonomer content and the rubbery polymer content.

As a method for measuring CXS by pulse NMR, for example, the following method can be used. That is,
First, the time change of the magnetic moment intensity of the sample is measured to obtain a free induction decay curve (FID). Since the CXS component is amorphous or low-crystalline, the relaxation time is long, and the time change of the magnetic moment intensity can be approximated by an exponential function.
On the other hand, the crystalline polypropylene component has a short relaxation time, and the time change of the magnetic moment intensity can be approximated by a Gaussian function. The FID obtained by pulsed NMR is
Since it is the sum of the signals emitted from the XS component and the crystalline polypropylene component, the FID can be mathematically separated into an exponential function component and a Gaussian function component. In the separation, it is not always necessary to separate the components one by one, but the components may be separated into a plurality of components. With the above operation,
The ratio of the exponential function component contained in the original FID is obtained, and this ratio is a function of the CXS contained in the original sample. Therefore, by creating a calibration curve using the ratio of the separately obtained CXS and this exponential function component, the CXS can be measured by pulse NMR.

The above principle can be applied to the measurement of comonomer content by pulsed NMR and the measurement of rubbery polymer content. For example, as the comonomer content increases, the crystallinity of the entire sample gradually decreases, and the proportion of the amorphous component tends to gradually increase. Therefore, similarly to the above-described CXS measurement, the ratio of the exponential function component is a function of the comonomer content included in the sample, and by using a separately calculated ratio of the comonomer content and the exponential function component to create a calibration curve, Measurement of comonomer content by pulsed NMR becomes possible.

The same applies to the measurement of the content of the rubbery polymer. That is, since the rubbery polymer is amorphous or low crystalline, the relaxation time is as long as that of CXS, and can be distinguished from the crystalline polypropylene component in this point. Therefore, similarly to the measurement of CXS, by preparing a calibration curve of the rubbery polymer content separately measured and the exponential function component contained in the FID, the rubbery polymer content can be measured by pulse NMR.

The frequency of pulse NMR measurement is not particularly limited, but is preferably performed once every about 10 minutes in order to perform stable measurements. When one measurement is completed, the sample is discharged from the measurement site, accepts the next sample, and starts measurement again.

(Feedback Step to Polymerization Conditions) When the pulse NMR measurement is completed, the measured value is compared with the target value as shown in FIG. And, as a result of the comparison,
If the measured value deviates from the target value, it is determined that the polymerization conditions for controlling the physical properties should be changed, and the information is fed back to the polymerization conditions, and the polymerization conditions are corrected. If there is no deviation, it is determined whether or not to continue the polymerization without modifying the polymerization conditions, and the operation policy is determined.

Various conventionally known controls are used for modifying the polymerization conditions. That is, proportional control, differential control, integral control, or any combination thereof is a typical control method. For example, in the proportional control, an output proportional to the difference between the measured value and the target value is fed back to the polymerization condition, and control is performed so that the physical properties approach the target value. Further, it is also possible to correct the polymerization conditions at the discretion of the operator without using an automatic control device.

Although the number of polymerization conditions to be corrected is not limited to one, in order to control efficiently, it is necessary to select a material which can rapidly change the physical properties to be controlled and has high control accuracy. For example, in the case of CXS control in a propylene homopolymer, controlling the supply rate of the electron donating compound to the polymerization tank provides the best control means.
In addition, in the case of the ethylene content of the random copolymer, control of the ethylene supply rate to the polymerization tank, and control of the rubbery polymer content in the block copolymer, when the control width is small, the rubber is controlled. When the polymerization pressure control of the rubbery polymer polymerization tank has a relatively large control range, the control of the supply rate of the activity control agent to the rubbery polymer polymerization tank as an optional component provides the best control means.

[0044]

The following examples are provided to further illustrate the present invention. The present invention is not limited thereby without departing from the gist thereof. In the following examples, Me, Et, Bu, and Ph represent a methyl group, an ethyl group, an n-butyl group, and a phenyl group, respectively. Further, m. r. Represents a molar ratio. DEP, TOL, TEA, and TBEDMS represent diethyl phthalate, toluene, triethylaluminum, and t-BuEtSi (OMe) ₂ , respectively. t-B
u represents a tertiary butyl group, and EPR represents an ethylene / propylene rubbery copolymer.

Example 1 (1) Production of Solid Catalyst Component (A) 10 equipped with a stirring blade, thermometer, jacket and cooling coil
In a 0 liter reactor, Mg (OEt) ₂ : 30 mol
And then Ti (OBu) ₄ and Mg
For the magnesium in (OEt) ₂ , Ti (OB)
u) _{4 /} Mg = 0.60 (mr). Further, 19.2 kg of toluene was charged, and the temperature was raised while stirring. After reacting at 139 ° C. for 3 hours, 13
The temperature was lowered to 0 ° C., and the toluene solution of MeSi (OPh) ₃ was added to the magnesium in Mg (OEt) ₂ previously charged, and MeSi (OPh) ₃ /Mg=0.67 (m.
r. ). The amount of toluene used here was 7.8 kg. 130 ° C after completion of addition
At room temperature for 2 hours, and then cooled to room temperature.
t) ₄ was added. The addition amount of Si (OEt) ₄ is based on the magnesium in Mg (OEt) ₂ previously charged.
Si (OEt) _{4 /} Mg was set to be 0.056 (mr).

Next, toluene was added to the obtained reaction mixture so that the magnesium concentration became 0.58 (mol / L · TOL). Further, diethyl phthalate was added to magnesium in Mg (OEt) ₂ previously charged so that DEP / Mg = 0.10 (mr). The resulting mixture was cooled to −10 ° C. with continued stirring, and TiCl ₄ was added dropwise over 2 hours to obtain a homogeneous solution. It should be noted that TiCl ₄ is used in place of the magnesium in Mg (OEt) ₂ previously charged with Ti.
Cl _{4 /} Mg was set to 4.0 (mr).
After completion of the TiCl ₄ addition, 0.5 ° C./min while stirring.
To 15 ° C. and kept at the same temperature for 1 hour. Next, the temperature was raised again to 50 ° C. at a rate of 0.5 ° C./min and maintained at the same temperature for 1 hour. Further, the temperature was raised to 118 ° C. at 1 ° C./min, and the treatment was performed at the same temperature for 1 hour. After processing,
After the stirring was stopped and the supernatant was removed, the solid was washed with toluene to a residual liquid ratio of 1/73 to obtain a solid slurry.

Next, toluene and TiCl ₄ were added to the obtained slurry at room temperature. Note that TiCl
₄ is TiCl ₄ / Mg (OEt) ₂ = 5.0 with respect to magnesium in Mg (OEt) ₂ previously charged.
(Mr). Toluene is T
The iCl ₄ concentration was adjusted to 2.0 (mol / L · TOL). This slurry is heated while stirring,
The reaction was performed at 118 ° C. for 1 hour. After completion of the reaction, the stirring was stopped, and the supernatant was removed.
/ 150 to obtain a slurry of the solid catalyst component (A).

(2) Production of Prepolymerized Solid Catalyst Component (B) 400 g of the solid catalyst component (A) obtained in the above Example 1 (1) was added to another having a stirring blade, a thermometer and a cooling jacket. The mixture was transferred to a reactor, and normal hexane was added to dilute the solid catalyst component (A) to a concentration of 3.0 (g / L). While stirring the obtained slurry, 2
At 0 ° C., TEA and TBEDMS were added. Note that TE
A, the amount of TBEDMS added was TEA /
(A) = 3.4 (mmol / g), TBEDMS /
(A) = 1.4 (mmol / g). After completion of the addition, the mixture was kept at 20 ° C. for 30 minutes while continuously stirring. Next, 1.2 kg of propylene gas was fed into the gas phase of the reactor at a constant speed over 72 minutes to perform prepolymerization. During the feed of propylene gas, cooling was performed so that the internal temperature of the reactor was maintained at 20 ° C. After the feed was completed, stirring was stopped to remove the supernatant, and then the resultant was washed with normal hexane to obtain a slurry of the prepolymerized solid catalyst component (B). In addition, the residual liquid ratio was set to 1/12. The obtained prepolymerized solid catalyst component (B) had 2.8 g of a propylene polymer per 1 g of the solid catalyst component (A).

(3) For preparing a calibration curve for measuring the EPR content
As shown in FIG. 1, the inner volume was 0.4 m.^ThreeLiquid with stirrer
Phase polymerization tank 1, 0.5m ^ThreeBetween the stirred gas-phase polymerization tanks 8
Sedimentation hydraulic classifier 4, concentrator 3 (liquid cyclone), and
Classification system consisting of pump and countercurrent pump 13 and double
Degassing system consisting of tubular heat exchanger 5 and fluidized flash tank
Propylene and ethylene
Continuous production of unblock copolymer was carried out.

To the liquid phase polymerization tank 1, liquefied propylene, hydrogen, TEA, and TBEDMS were continuously fed. The feed amounts of liquefied propylene, TEA, and TBEDMS were 130 kg / hr and 14.3 g / h, respectively.
r, 1.5 g / hr, total pressure of hydrogen is 36.8 k
gf / cm ² . Further, the prepolymerized solid catalyst component (B) obtained in Example 1 (2) was
As the solid catalyst component (A) contained in (B), 0.7
g / hr. Further, the liquid phase polymerization tank 1 was cooled so that the polymerization temperature was 75 ° C.

The slurry polymerized in this polymerization tank was fed to the hydraulic classifier 4 using the slurry pump 2 at a volume flow rate of about 12 m ³ / hr. From the lower part of the hydraulic classifier 4,
A slurry containing a relatively large amount of large-diameter particles was extracted, and the remaining slurry was extracted from the upper part of the hydraulic classifier 4 and supplied to the concentrator 3. From the upper part of the concentrator 3, a supernatant liquid containing almost no solid particles was taken out, and supplied to the lower part of the hydraulic classifier using the pump 13 as a countercurrent. on the other hand,
The slurry containing a relatively large amount of small-diameter particles extracted from the lower part of the concentrator 3 was circulated to the liquid-phase polymerization tank 1. The extraction rate of the slurry extracted from the lower part of the hydraulic classifier 4 is as follows:
As the polypropylene particles contained in the slurry, about 2
It was adjusted to 5 kg / hr. The average residence time of the polypropylene particles in the liquid phase polymerization tank 1 and the slurry circulation line was 1.3 hours.

The above-mentioned slurry extracted from the lower part of the hydraulic classifier 4 was fed to the fluidized flash tank 6 through the double tube heat exchanger 5. In the fluidized flash tank 6, the temperature inside the tank was maintained at 70 ° C. while feeding heated propylene gas from below. The solid polypropylene particles obtained here were sent to a gas-phase polymerization tank 8, where EPR polymerization comprising propylene and ethylene was performed.

In order to enhance the mixing effect, a mixed gas of ethylene, propylene and hydrogen was circulated by a blower 7 in a gas phase polymerization tank 8 provided with an auxiliary stirring blade. The sum of the partial pressures of ethylene and propylene is 14.0 kgf /
cm ² , and the mole fraction of propylene is 55 mol%
Was fed to the gas phase polymerization tank 8. Hydrogen was fed so that the molar fraction of hydrogen was 2.0 mol%. Further, ethanol was fed from the lower part of the gas phase polymerization tank 8. The feed amount of ethanol was adjusted to be 1.4 mol per 1 mol of aluminum in the organoaluminum compound supplied to the gas-phase polymerization tank 8 accompanying the solid polypropylene particles. The polymerization temperature was adjusted to 80 ° C., and the average residence time in the gas phase polymerization tank 8 was adjusted to 1.0 hour.

The block copolymer particles extracted from the lower part of the gas phase polymerization tank 8 are sent to a screw feeder 16, and then from the screw feeder, a dryer 17.
And dried at a temperature of 90 ° C. with an average residence time of 0.5 hours. Note that nitrogen was used for drying. The dried block copolymer particles are sent to a hopper 18, and finally, the block copolymer is taken out from the hopper and subjected to EPR.
It was used as a sample for content measurement.

Similarly, the average residence time in the liquid-phase polymerization tank 1, the average residence time in the gas-phase polymerization tank 8, the amount of ethanol fed to the gas-phase polymerization tank 8, the partial pressure of ethylene and propylene in the gas-phase polymerization tank 8 By changing the mole fraction of propylene and the mole fraction of hydrogen, a total of 75 kinds of various block copolymers were produced.

(4) Measurement of EPR content by cross fractionation method The block weight obtained in Example 1 (3) was measured by a cross fractionation method using a "CFC-T-102L" heated elution fractionation apparatus manufactured by Mitsubishi Chemical Corporation. The EPR content in the combined was measured. In addition,
The measurement conditions are shown in Table 1. The EPR content is 40
It was defined as the weight fraction of the eluted components below ° C.

[0057]

[Table 1]

(5) Preparation of Calibration Curve for EPR Content by Pulse NMR Method Using the pulse NMR “IMR-2000” manufactured by Auburn, the EPR content of the block copolymer obtained in Example 1 (3) was determined at 60 ° C. Was measured. The calibration curve was prepared using the EPR content obtained in Example 1 (4). FIG. 3 shows the relationship between the rubber content ([EPR] _NMR ) obtained by pulse NMR obtained based on the obtained calibration curve and the rubber content ([EPR] _CFC ) obtained by the cross fractionation method. R ² was 0.94.

(6) Production of block copolymer using pulse NMR In the same manner as in Example 1 (3), a block copolymer having an EPR content of 24% by weight was produced. First, as initial conditions, the average residence time in the liquid phase polymerization tank 1 was set to 1.0 hour, and the average residence time in the gas phase polymerization tank 8 was set to 1.7 hours. Further, the gas phase composition in the gas phase polymerization tank 8 was set to 75 mol% of propylene and 1.0 mol% of hydrogen. Further, the sum of the partial pressures of propylene and ethylene in the gas phase polymerization tank 8 was set to 16.0 kgf / cm ² . Other conditions were the same as in Example 1 (3).

After starting the operation, the dried block copolymer was taken out from the hopper 18 every hour, and
The EPR content was measured by pulse NMR in the same manner as in (5). After the whole system reached steady state, in the first measurement, the target was not reached at the EPR content by pulse NMR of 18.4% by weight, so the conditions were changed based on this information. That is, under the initial conditions, the amount of ethanol feed in the gas phase polymerization vessel 8 is 1.4 mol per 1 mol of aluminum in the organoaluminum compound supplied to the gas phase polymerization vessel 8 accompanying the solid polypropylene particles.
1 was set to 1.3 mo
The condition was changed to be 1.

As a result of this condition change, the EPR content gradually increased, and pulse NMR measurement 6 hours after the condition change showed that:
An EPR content of 24.7% by weight close to the target value was obtained. Therefore, hereafter, this operating condition is continued. The operation was continued while measuring the EPR content by pulse NMR every 0.5 hour. During the operation, the EPR content was finely adjusted by controlling the pressure of the gas phase polymerization tank 8 based on the results of pulse NMR measurement. As a result, EP
With good controllability of 24 ± 1.5% by weight as R content,
A two-day stable operation was achieved. Also, during two days of driving,
The rubber content of the arbitrarily sampled block copolymer was measured by a cross fractionation method, and the pulse NMR method was validated. EPR content and pulse N by cross fractionation
The EPR content by the MR method was in good agreement within the range of 1.5% by weight. FIG. 4 shows the measurement results of the EPR content (indicated by [EPR] _NMR ) by pulsed NMR. In addition,
Time (hr) on the horizontal axis indicates the elapsed time after the start of the polymerization.

(Comparative Example 1) (1) Production of block copolymer without using pulse NMR Example 1 (6) except that pulse NMR was not used.
In the same manner as in the above, a block copolymer was produced. In the production, in order to control the operation of the EPR content, 72
The absorbance at 0 cm ^-1 was measured and multiplied by a factor to calculate the EPR content. The measurement was performed as follows.

First, the block copolymer was heated at a temperature of 200
At a pressure of 50 kgf / cm ² and a thickness of about 100
A pressed film of μ was prepared. Next, JASCO A-
The IR spectrum of the film was measured with a type 202 infrared spectrophotometer, and the ethylene content [E] _B defined by the following equation was determined.

[0064]

(Equation 1)

Here, ΔA ₇₂₀ represents the absorbance at ₇₂₀ cm ⁻¹ , and t represents the thickness (mm) of the film. Then, the EPR content was defined by the following equation.

[0066]

[EPR] = f · [E] _B

Here, [EPR] represents the EPR content and f
Represents a constant mainly determined by the propylene fraction in the gas-phase polymerization tank 8. The measurement result of the EPR content by the cross fractionation method which was separately measured, and [E] _B by the above IR
By comparison with the measurement results of
f at 1% was determined to be about 7.0.

Thereafter, once an hour, E is calculated based on IR.
PR was measured and the operation was performed for 2 days. During the operation, the EPR content was controlled by controlling the ethanol feed amount and / or the sum of the partial pressures of ethylene and propylene in the gas-phase polymerization tank 8 as in Example 1 (6). After the operation was completed, the EPR content of the obtained block copolymer was measured again by the cross fractionation method.
It fluctuated between 7% by weight, and the operation stability was poor. FIG. 5 shows EPs revealed by the cross fractionation method.
The actual transition of the R content (denoted as [EPR] _CFC ) is shown.
The time on the horizontal axis indicates the elapsed time after the start of the polymerization.

Comparative Example 2 (1) Production of Block Copolymer Using Cross Fractionation A block copolymer was prepared in the same manner as in Example 1 (6) except that a pulse fractionation method was used without using pulse NMR. A copolymer was produced. Since the measurement of the EPR content by the cross fractionation method takes 4 hours to measure one point, the EPR content could be known only once every 4 hours during operation. For this reason, the operation stability was poor, and the EPR content was measured again after the end of the operation, and found to vary between 17 and 25% by weight. FIG. 6 shows EP measured by the cross fractionation method.
The transition of R content (referred to as [EPR] _CFC ) is shown. In addition,
The time on the horizontal axis indicates the elapsed time after the start of the polymerization.

Example 2 (1) Production of Prepolymerized Solid Catalyst Component (B) Four of the solid catalyst component (A) obtained in Example 1 (1)
00 g was transferred to another reactor having a stirring blade, a thermometer, and a cooling jacket, and normal hexane was added to dilute the solid catalyst component (A) to a concentration of 5.0 (g / L). . 15 ° C. while stirring the obtained slurry.
With trimethylvinylsilane, TEA and TBMDE
S was added. Here, TBMDES indicates t-butylmethyldiethoxysilane, and t-butyl indicates a tertiary butyl group. The amounts of TEA and TBMDES added were respectively TEA / (A) = 3.1 (mmol)
/ G), trimethylvinylsilane / (A) = 0.2 (m
L / g), TBMDES / (A) = 0.2 (mL / g)
It was made to become. After completion of the addition, the mixture was maintained at 15 ° C. for 1 hour with continued stirring, further heated to 30 ° C., and stirred at the same temperature for 2 hours. Next, the temperature was lowered again to 15 ° C., and while maintaining the same temperature, 1.2 g
kg of propylene gas was fed at a constant speed over 72 minutes to perform prepolymerization. After the feed was completed, stirring was stopped to remove the supernatant, and then the resultant was washed with normal hexane to obtain a slurry of the prepolymerized solid catalyst component (B). In addition, the residual liquid ratio was set to 1/12. The obtained pre-polymerized solid catalyst component (B) was mixed with the solid catalyst component (A):
It had 2.8 g of propylene polymer.

[0071] (2) As shown in CXS measurement calibration sample preparation Figure 1 for the creation, stirred gas phase stirred apparatus with liquid phase polymerization vessel 1,0.5M ³ having an inner volume of 0.4 m ³ Between the polymerization tanks 8, a sedimentation liquid classifier 4, a concentrator 3 (liquid cyclone),
And a classification system comprising a countercurrent pump 13 and
By a process incorporating a degassing system consisting of a double tube heat exchanger 5 and a fluidized flash tank 6, propylene
Continuous production of a homopolymer was performed.

To the liquid phase polymerization tank 1, liquefied propylene, hydrogen, TEA, and TBEDMS were continuously fed. The feed amounts of liquefied propylene, TEA, and TBEDMS were 130 kg / hr and 12.7 g / h, respectively.
r, 0.8 g / hr, total pressure of hydrogen is 31.5 k
gf / cm ² . Furthermore, the prepolymerized solid catalyst component (B) obtained in Example 2 (1) was
As the solid catalyst component (A) contained in (B), 0.4
Feeding was carried out at 6 g / hr. Further, the liquid phase polymerization tank 1 was cooled so that the polymerization temperature was 75 ° C.

The slurry polymerized in this polymerization tank was fed to the hydraulic classifier 4 using the slurry pump 2 at a volume flow rate of about 12 m ³ / hr. From the lower part of the hydraulic classifier 4,
A slurry containing a relatively large amount of large-diameter particles was extracted, and the remaining slurry was supplied to the concentrator 3 from above the hydraulic classifier 4. From the upper part of the concentrator 3, a supernatant liquid containing almost no solid particles was taken out, and supplied to the lower part of the hydraulic classifier using the pump 13 as a countercurrent. On the other hand, the slurry containing a relatively large amount of small-diameter particles extracted from the lower part of the concentrator 3 was circulated to the liquid-phase polymerization tank 1. The withdrawal rate of the slurry withdrawn from the lower part of the hydraulic classifier 4 is about 25 kPa as the polypropylene particles contained in the slurry.
g / hr. The average residence time of the polypropylene particles in the liquid phase polymerization tank 1 and the circulation line was 1.0 hour.

The above-mentioned slurry extracted from the lower part of the hydraulic classifier 4 was fed to the fluidized flash tank 6 through the double tube heat exchanger 5. In the fluidized flash tank 6, the temperature inside the tank was maintained at 70 ° C. while feeding heated propylene gas from below. The solid polypropylene particles obtained here were sent to the gas phase polymerization tank 8.

In order to enhance the mixing effect, CO was fed to the gas-phase polymerization tank 8 provided with an auxiliary stirring blade to deactivate the catalyst. Then, the polypropylene polymer is
It was withdrawn from the lower part of the gas phase polymerization tank 8, sent to a fluidized drier 17 through a screw feeder 16, and dried at a temperature of 90 ° C. for an average residence time of 0.5 hours. Note that nitrogen was used for drying. The dried polypropylene polymer particles were sent to a hopper 18. Finally, the propylene homopolymer was taken out of the hopper and used as a sample for CXS measurement. Similarly, a total of 39 kinds of various homopolymers were produced by changing the amount of TBEDMS fed to the liquid phase polymerization tank 1.

(3) Measurement of CXS with xylene About 1 g of the sample of the polypropylene homopolymer obtained in Example 2 (2) was precisely weighed in an eggplant-shaped flask, and 200 mL of xylene was added thereto. Boil and dissolve completely. Then, this was quenched in a water bath at 25 ° C,
A solid precipitated. The precipitated solid portion was filtered, 50 mL of the filtrate was evaporated to dryness in a platinum dish, and further dried under reduced pressure and weighed. CXS is polypropylene
It was calculated as a xylene-soluble component at 25 ° C. in the homopolymer.

(4) Preparation of CXS Calibration Curve by Pulsed NMR Method The CXS of the propylene homopolymer obtained in Example 2 (2) was subjected to CXS at 60 ° C. using a pulsed NMR [IMR-2000] manufactured by Auburn. It was measured. Note that CXS obtained in Example 2 (3) was used to create a calibration curve. C by pulse NMR determined based on the obtained calibration curve
XS (CXS _NMR ) and CX obtained using xylene
FIG. 7 shows the relationship of S (CXS _XYL ). R ² is 0.94
Met.

(5) Production of propylene homopolymer using pulse NMR In the same manner as in Example 2 (2), a propylene homopolymer having a target of 3.7% by weight of CXS was produced. Next, the target value of CXS was adjusted to 5.5% by weight and 6.7%.
The operation was changed to the weight%. First, as initial conditions,
Assuming that the average residence time of the liquid phase polymerization tank 1 is 1.0 hour, TB
The feed amount of EDMS was 15.3 mg / hr.
Other conditions were the same as in Example 2 (2).

After starting the operation, the dryer 17 is moved from the hopper 18
Example 2 (4): A sample of the dried propylene homopolymer was sampled about every 10 minutes from the middle of the pipe leading to Example 2.
In the same manner as in the above, CXS was measured by pulse NMR. After the whole system reaches steady state, CX by pulse NMR
Since S was 3.9%, which was almost the target, the operation was continued without any change in conditions. Subsequently, the operation was continued while measuring CXS about every 10 minutes by pulse NMR. As a result, stable operation for about 9 hours was achieved.

Next, in order to change the CXS target value to 5.5% by weight, the feed amount of TBEDMS was set to 5.4 mg.
/ Hr. Subsequently, by pulse NMR, about 10
Changes in CXS were monitored while measuring CXS every minute. After about 15 hours, the CXS value by pulsed NMR had reached a steady state, indicating that the system had reached a new steady state. At this time, CXS was about 5.5% and almost reached the target value. Therefore, the operation was continued for about 5 hours without changing the conditions.

Subsequently, in order to change the CXS target value to 6.7% by weight, the feed amount of TBEDMS was set to 2.5 m.
g / hr. As before, pulsed NMR
The change in CXS was monitored while measuring CXS about every 10 minutes. After about 10 hours, the CXS value by pulsed NMR had reached a steady state, indicating that the system had reached a new steady state. At this time, CXS was about 6.6%, which had almost reached the target value. Therefore, the operation was continued for about 5 hours without changing the conditions. Finally, a smooth grade change was obtained in about two days of operation.

During this operation, the arbitrarily selected sample was measured for CXS by the method shown in Example 2 (3) and compared with the method measured by pulsed NMR. Good agreement was shown within a value of 0.3% or less.
FIG. 8 shows CXS (CXS) measured by pulsed NMR.
S _NMR ). The time (hr) on the horizontal axis
Indicates the elapsed time since the polymerization system reached the first steady state.

Comparative Example 3 (1) Production of Propylene Homopolymer Using Pulsed NMR Example 2 was repeated except that a sample for pulsed NMR was sampled from the fluidized flash tank 6 without drying. A propylene homopolymer was produced in the same manner as in 5). In addition, the target value of CXS was set to 4.0%. Pulsed NMR despite constant operating conditions
The CXS obtained by the above has a slightly large fluctuation,
Obtained between 5.1%. CXS of a part of the obtained sample was measured by the method described in Example 2 (3), and it was CXS = 4.0 ± 0.3%. That is, when the sample obtained from the fluidized flash tank 6 was measured by pulse NMR, a value higher than the true value tended to be obtained, and accurate measurement was not possible.

Example 3 (1) Production of Sample for Creating Calibration Curve for Measuring Ethylene Content As shown in FIG. 1, a liquid phase polymerization tank 1 having an internal volume of 0.4 m ^{3 and} a stirring device, 0.5 m ³ , a sedimentation hydrostatic classifier 4, a concentrator 3 (liquid cyclone),
Continuous production of a propylene / ethylene / random copolymer was carried out by a process incorporating a classification system including the countercurrent pump 13 and a degassing system including the double-pipe heat exchanger 5 and the fluidized flash tank 6.

The liquid-phase polymerization tank 1 was continuously fed with liquefied propylene, ethylene gas, hydrogen, TEA, and TBEDMS. In addition, liquefied propylene, ethylene, TEA,
The feed amount of TBEDMS was 130 kg /
hr, 0.5 kg / hr, 12.7 g / hr, 1.5 g
/ Hr, and hydrogen was fed so that H ₂ / PPY in the gas phase became 0.1. Where H ₂ / PP
Y represents the ratio of the mole fraction of H ₂ and propylene in the gas phase. Further, the pre-polymerized solid catalyst component (B) obtained in Example 1 (2) was fed as the solid catalyst component (A) contained in (B) at a rate of 0.37 g / hr. Further, the liquid phase polymerization tank 1 was cooled so that the polymerization temperature was 75 ° C.

The slurry polymerized in the polymerization tank was fed to the hydraulic classifier 4 using the slurry pump 2 at a volume flow rate of about 12 m ³ / hr. From the lower part of the hydraulic classifier 4,
A slurry containing a relatively large amount of large-diameter particles was extracted, and the remaining slurry was supplied to the concentrator 3 from above the hydraulic classifier 4. From the upper part of the concentrator 3, a supernatant liquid containing almost no solid particles was taken out, and supplied to the lower part of the hydraulic classifier using the pump 13 as a countercurrent. On the other hand, the slurry containing a relatively large amount of small-diameter particles extracted from the lower part of the concentrator 3 was circulated to the liquid-phase polymerization tank 1. The extraction rate of the slurry extracted from the lower part of the hydraulic classifier 4 was adjusted to be about 25 kg / hr as propylene / ethylene / random copolymer particles contained in the slurry. The average residence time of the propylene / ethylene / random copolymer particles in the liquid phase polymerization tank 1 and the circulation line was 1.0 hour.

The above-mentioned slurry extracted from the lower part of the hydraulic classifier 4 was fed to the fluidized flash tank 6 through the double tube heat exchanger 5. In the fluidized flash tank 6, the temperature inside the tank was maintained at 70 ° C. while feeding heated propylene gas from below. The solid propylene / ethylene / random copolymer particles obtained here are
It was sent to the gas phase polymerization tank 8.

In order to enhance the mixing effect, CO was fed to the gas-phase polymerization tank 8 provided with an auxiliary stirring blade to deactivate the catalyst. Next, the propylene / ethylene / random copolymer is withdrawn from the lower part of the gas phase polymerization tank 8 and is passed through a screw feeder 16 to a fluid dryer 17.
And dried at a temperature of 90 ° C. with an average residence time of 0.5 hours. Note that nitrogen was used for drying. The dried propylene / ethylene / random copolymer particles were sent to the hopper 18. Finally, propylene
The ethylene random copolymer was taken out and used as a sample for measuring the ethylene content. Similarly, a total of 23 kinds of various propylene / ethylene / random copolymers were produced by changing the amount of ethylene gas fed to the liquid phase polymerization tank 1.

(2) Measurement of ethylene content by IR The propylene / ethylene / random copolymer obtained in Example 3 (1) was subjected to a temperature of 200 ° C. and a pressure of 50 kgf / cm.
Pressing was performed at ² to produce a pressed film having a thickness of about 100 μ. Next, the IR spectrum of the film was measured with a JASCO A-202 type infrared spectrophotometer, and the ethylene content [E] _R defined by the following equation was determined.

[0090]

(Equation 3)

Here, ΔA ₇₃₀ represents the absorbance at ₇₃₀ cm ⁻¹ , and t represents the thickness (mm) of the film.

(3) Preparation of a calibration curve for ethylene content by pulse NMR Using the NMR [IMR-2000] manufactured by Auburn, the propylene-ethylene-propylene obtained in Example 3 (1) was used.
The ethylene content in the random copolymer was measured at 60 ° C. The calibration curve was prepared using the ethylene content obtained in Example 2 (2). FIG. 9 shows the relationship between [E] _{R (NMR)} by pulse NMR determined based on the calibration curve and the ethylene content [E] _{R (IR)} determined by _IR . R ² was 0.98.

(4) Production of propylene / ethylene / random copolymer using pulsed NMR In the same manner as in Example 3 (1), propylene / ethylene / random copolymer having a target ethylene content of 2.1% by weight was prepared. A polymer was produced. First, as an initial condition, the feed rate of ethylene gas was 0.5 kg / hr. Other conditions were the same as in Example 3 (1).

After the start of the operation, the propylene / ethylene / random copolymer removed from the hopper 18 was pelletized at a temperature of 220 ° C. and a screw rotation speed of 100 rpm using a 40 mmφ extruder manufactured by Osaka Seiki Co., Ltd. The obtained pellets were sampled every 0.5 hour,
In the same manner as in (3), the ethylene content [E] _R was measured by pulse NMR. After the entire system reached a steady state, the [E] _R by pulse NMR was 1.7% and did not reach the target.
kg / hr. Continued by pulse NMR,
When [E] _R was measured every 0.5 hour, [E] _R
As a result, a target of 2.1% by weight was obtained. FIG.
[E] measured by pulsed NMR
The transition of _R ([E] _{R (NMR)} ) is shown. The time on the horizontal axis indicates the time elapsed from the start of polymerization.

(Comparative Example 4) (1) Propylene ethylene ethylene using pulsed NMR
Production of random copolymer Sample for pulse NMR,
A propylene / ethylene / random copolymer was produced in the same manner as in Example 3 (4) except that the sample was sampled from the fluidized flash tank 6 without drying. The supply of ethylene gas to the liquid-phase polymerization tank 1 was 0.6 k
g / hr. The sample obtained from the fluidizing flash tank 6 had a large fluctuation in particle fluidity. Then, despite maintaining the operating conditions constant, the ethylene content determined by pulsed NMR fluctuates greatly, and [E] _R =
Values of 2.1-2.6 wt% were obtained. On the other hand, Example 3
Similarly to (4), when the [E] _R of the sample that had entered the hopper 18 via the dryer 17 was measured by pulse NMR, 1.9 to 2.1 wt% was obtained. That is, in the case of the sample obtained from the fluidized flash tank 6,
[E] _R higher than the true value tended to be obtained, and accurate measurement was not possible.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of an apparatus for implementing the present invention.

FIG. 2 is a flowchart showing a control system of the present invention.

FIG. 3 is a graph showing the relationship between the rubber content measured by pulse NMR measured in Example 1 and the rubber content measured by cross fractionation.

FIG. 4 is a graph showing the change over time in the rubber content in Example 1.

FIG. 5 is a graph showing the change over time in rubber content in Comparative Example 1.

FIG. 6 is a graph showing the change with time of the rubber content in Comparative Example 2.

FIG. 7 is a graph showing the relationship between CXS measured by pulse NMR measured in Example 2 and CXS measured using xylene.

FIG. 8 is a graph showing the change over time of CXS in Example 2.

FIG. 9 is a graph showing the relationship between the ethylene content measured by pulse NMR and the ethylene content measured by IR measured in Example 3.

FIG. 10 shows the change over time of the rubber content in Example 3.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid-phase polymerization tank 2 Slurry pump 3 Concentrator 4 Hydraulic classifier 5 Double tube heat exchanger 6 Fluid flash tank 7 Gas blower 8 Gas-phase polymerization tank 9 Circulating gas cooler 10 Gas blower 11 Heat exchanger 12 Cyclone 13 Countercurrent Pump 14 Cyclone 15 Hopper 16 Screw feeder 17 Dryer 18 Hopper 19 Sampling line for pulsed NMR

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 3/12 CES C08J 3/12 CESSZ F term (Reference) 4F070 AA12 AA15 DC06 4J011 AA05 AB01 AB11 AC03 4J026 HA04 HA27 HA32 HA38 HB03 HB04 HB27 HB35 HB45 HB46 HB48 HE06 4J100 AA02Q AA03P CA01 CA04 FA01

Claims (4)

[Claims] 1. A method for producing an olefin polymer, comprising the following steps (a) to (f). (A) a step of supplying an olefin, hydrogen, a transition metal catalyst component, a cocatalyst, and, if necessary, an electron-donating compound to a polymerization tank to continuously polymerize the olefin, and (b) a step obtained in the step (a). Removing the olefin polymer obtained from the polymerization tank, (c) drying and / or granulating the olefin polymer obtained in step (b), and (d) olefin obtained in step (c). (E) continuously or intermittently sampling the polymer, (e) measuring the sample obtained in step (d) using pulsed nuclear magnetic resonance to obtain measured values of physical properties to be controlled, (f) A) comparing the measured values of the physical properties determined in the step (e) with target values, and determining whether to change polymerization conditions capable of controlling the physical properties based on the obtained comparison results; 2. The method for producing an olefin polymer according to claim 1, wherein the olefin polymer is a homopolymer of propylene or a copolymer of propylene and an α-olefin other than propylene. 3. The method for producing an olefin polymer according to claim 1, wherein the physical properties to be controlled are a xylene-soluble content, a comonomer content, or a rubbery polymer content at 23 ° C. 4. The olefin polymer is a block copolymer of propylene and ethylene, and the physical property to be controlled is 23 ° C.
The method for producing an olefin polymer according to claim 1 or 2, wherein the content is a xylene-soluble content, an ethylene content, and / or a rubbery ethylene-propylene-random copolymer content.