JPH06322027A - Method for operating reactor of vapor-phase olefin polymerization - Google Patents

Abstract

PURPOSE:To prevent formation of a polymer sheet in a reactor and clogging of piping and to continue the stable operation of the reactor by supplying an org. acid to the reactional system in the process for producing a polyolefin wherein a catalyst comprising a solid catalyst component contg. titanium, etc., and an organoaluminum compd. as an auxiliary catalyst is supplied to the reactor and an olefin in vapor phase is constantly (co)polymerized. CONSTITUTION:A seed polymer is charged into a fluidized bed reactor 1 comprising the upper space 2, a fluidized bed region 3, and a gas-dispersion plate 4; nitrogen gas is supplied from a supply pipe 10, and the gas in the system is recirculated with a blower 12 through the route comprising the reactor 1, gas- recirculation piping 11, and a cooler 13 to maintain the reaction temp.; an auxiliary catalyst is supplied from a supply pipe 5; hydrogen, from a supply pipe 6; an olefin, from a supply pipe 7; a solid catalyst component, from a supply pipe 8; and the reaction is started. The rate of polymer formation increases slowly, and after a while, a polymer sheet is detected at discharge valves 14 and 15. Then, an org. acid soln. is supplied through a supply pipe 9 to the recirculation system to stop formation of the polymer sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating a reactor for producing a polyolefin by a gas phase polymerization method. More specifically, it relates to a method of operating an olefin gas phase polymerization reactor which prevents the formation of a sheet polymer.

[0002]

2. Description of the Related Art In the gas phase polymerization of olefins, when the operation of the apparatus is started, a sheet-like polymer is produced, and the operation may be stopped by closing the pipe. In order to prevent this, it has been proposed to install an electrostatic voltmeter in the polymerization reactor and measure the static electricity of the polymer particles in the reactor to control it. That is, when the absolute value of the electrostatic voltage is large, the polymer particles adhere to the inner wall surface of the reactor, and the reaction proceeds at that portion to cause fusion to form a sheet-like polymer. This is because it is considered necessary to control the electrostatic voltage of the polymer particles to reduce the absolute value. The above is described in detail in the existing patent publications. For example, JP-A 1-2
According to the invention of Japanese Patent No. 30607, an electrostatic level meter is installed at a position where a sheet-shaped polymer is easily generated in a gas phase polymerization reactor, and when the electrostatic level is negative, alcohol is used as a positive charge generating chemical additive, Add oxygen or nitric oxide,
Bring the electrostatic level close to zero. When the electrostatic level is positive, on the contrary, ketone is added as a negative charge generating chemical additive to bring the electrostatic level close to zero. In this way, an additive that generates either positive or negative charge is added according to the charge of the polymer particles in the gas-phase polymerization reactor to keep the electrostatic level substantially neutral and to prevent the formation of the sheet polymer. A method of prevention is disclosed. Further, Japanese Patent Laid-Open No. 2-145608 discloses that
In order to reduce the positive electrostatic voltage of the polymer particles in the gas phase polymerization reactor, it is described that it is effective to add a trace amount of water continuously, and thus, it is possible to obtain a certain amount of water. If the electrostatic voltage is brought to zero by adding impurities,
It states that the formation of sheet polymer can be avoided. However, all of the above alcohols, oxygen, nitric oxide, water, etc. are strong catalyst poisons, and there is a problem in that the catalytic activity is lowered.

Generally, in the operation of a gas phase polymerization reactor, after the seed polymer is filled, oxygen and the like in the reaction system are removed, and then a catalyst is supplied to start the polymerization reaction, and then the polymer is gradually produced. The amount increases. But,
When several hours to several tens of hours have passed after the start of the reaction, a sheet-like polymer is produced, which may force the operation of the gas phase polymerization reactor to be stopped.

[0004]

The relationship between the formation of sheet polymer and the electrostatic phenomenon in the reaction system has not been fully clarified, and it is concluded that the sheet polymer is produced only by the cause of static electricity at present. It is not possible. It cannot be said that the above-mentioned various conventional techniques are sufficiently effective, therefore, it is desired to establish a method of operating a gas phase polymerization reactor without producing a sheet polymer.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have suppressed the production of a sheet polymer by supplying an organic acid into a gas phase polymerization reaction system. The inventors have reached the present invention by finding that they can obtain it. That is, the present invention is a method of supplying a catalyst comprising a solid catalyst component containing at least titanium and / or vanadium and magnesium and an organoaluminum compound to a reactor to constantly polymerize or copolymerize an olefin in a gas phase. In the above, there is provided a method for operating an olefin vapor phase polymerization reactor characterized by preventing the production of a sheet polymer in the reactor by supplying an organic acid into the reaction system.

The present invention will be described in detail below. The olefin used in the present invention usually has 2 to 8 carbon atoms,
Preferably 2 to 6 olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1,
An α-olefin such as 4-methylpentene-1 may be mentioned. These can be used for homopolymerization or copolymerization at an appropriate ratio. As the copolymerization, for example, ethylene / propylene, ethylene / butene-1, ethylene / hexene-1, ethylene / 4-methylpentene-1, etc., and a C3-C12 α-olefin, propylene and Examples thereof include copolymerization with butene-1, and copolymerization with ethylene and two or more kinds of other α-olefins. Further, copolymerization using a diene is also possible for the purpose of modifying the polyolefin. Examples of the diene used for this purpose include butadiene, 1,4-hexadiene, ethylidene norbornene and dicyclopentadiene. The olefin can be fed to the reaction system preferably with a suitable inert carrier gas such as nitrogen.

As the catalyst used for the above-mentioned olefin polymerization, a catalyst comprising a solid catalyst component containing at least titanium and / or vanadium and magnesium and an organoaluminum compound is used. As the solid catalyst component containing at least titanium and / or vanadium and magnesium, a solid catalyst component containing titanium and magnesium used in a Ziegler-based catalyst conventionally known as a catalyst for olefin polymerization, and a solid catalyst component containing vanadium and magnesium Alternatively, a solid catalyst component containing titanium, vanadium and magnesium can be used.

Examples of the solid catalyst component include metal magnesium, magnesium hydroxide, magnesium carbonate,
Magnesium oxide, magnesium chloride, etc., also silicon,
Double salts, double oxides, carbonates, chlorides or hydroxides containing an element selected from aluminum and calcium and a magnesium atom, and further inorganic solid compounds thereof are oxygen-containing compounds, sulfur-containing compounds, aromatic carbons. Examples thereof include inorganic solid compounds containing magnesium such as those treated or reacted with a substance containing hydrogen or halogen and having a titanium compound and / or a vanadium compound supported by a known method.

Examples of the oxygen-containing compound include water; polysiloxane; organic oxygen-containing compounds such as alcohols, phenols, ketones, aldehydes, carboxylic acids, esters and acid amides; metal alkoxides; inorganic compounds such as metal oxychlorides. An oxygen compound can be illustrated. Examples of the sulfur-containing compound include organic sulfur compounds such as thiol and thioether, and inorganic sulfur compounds such as sulfur dioxide, sulfur trioxide and sulfuric acid. Examples of aromatic hydrocarbons include various monocyclic or polycyclic aromatic hydrocarbons such as benzene, toluene, xylene, anthracene, and phenanthrene. Examples of the halogen-containing substance include chlorine, hydrogen chloride, metal chlorides and organic halides.

Examples of the titanium compound include titanium halides, alkoxy halides, alkoxides,
Examples thereof include halogenated oxides. Of these, a tetravalent titanium compound and a trivalent titanium compound are preferable, and the tetravalent titanium compound is specifically represented by the general formula Ti (OR) _n X _4-n (where R is a carbon atom). A hydrocarbon group such as an alkyl group, an aryl group or an aralkyl group of the formulas 1 to 20, X represents a halogen atom, and n is a number in the range of 0 ≦ n ≦ 4.), Specifically, titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, monomethoxytrichlorotitanium, dimethoxydichlorotitanium, trimethoxymonochlorotitanium, tetramethoxytitanium, monoethoxytrichlorotitanium, diethoxydichlorotitanium, triethoxymonochlorotitanium. , Tetraethoxy titanium, monoisopropoxy trichloro titanium,
Diisopropoxydichlorotitanium, triisopropoxymonochlorotitanium, tetraisopropoxytitanium, monobutoxytrichlorotitanium, dibutoxydichlorotitanium, tributoxymonochlorotitanium, tetrabutoxytitanium, monopentoxytrichlorotitanium, monophenoxytrichlorotitanium, diphenoxydichloro. Titanium, triphenoxy monochloro titanium, tetraphenoxy titanium, etc. can be mentioned. The trivalent titanium compound has a general formula of Ti (OR) _m X _4-m (wherein R is a carbon number of 1 to 1).
20 represents a hydrocarbon group such as an alkyl group, an aryl group or an aralkyl group, and X represents a halogen atom. m is 0 <
It is a number in the range of m <4. And a trivalent titanium compound obtained by reducing the tetravalent alkoxyhalogenated titanium represented by the formula (1) with hydrogen, aluminum, titanium or an organometallic compound of a metal of Group I to III of the periodic table.

Of the above titanium compounds, tetravalent titanium compounds are particularly preferable. Specific examples of these catalysts include, for example, MgO-RX-TiCl ₄ system (Japanese Patent Publication No. 51-
3514 _{JP), Mg-SiCl 4 -ROH-} TiCl 4 type (JP-B 50-23864 discloses), MgCl ₂ -Al (O
R) ₃ -TiCl ₄ system (Japanese Patent Publication No. 51-152, Japanese Patent Publication No. 52-15111), MgCl ₂ -SiCl ₄ -RO
H-TiCl ₄ system (JP-A-49-106581), M
_{g (OOCR) 2 -Al (OR} ) 3 -TiCl 4 system (JP-B 52-
11710 JP), Mg-POCl ₃ -TiCl ₄ system (JP-B 51-153 discloses), MgCl ₂ -AlOCl-TiCl ₄
System (Japanese Patent Publication No. 54-15316), MgCl ₂ -Al
(OR) _n X _3-n -Si (OR ') _m X _4-m -TiCl ₄ system (JP _-A- 56-95909) and other solid catalyst components (in the above formula, R and R'are organic. A preferable example is a residue in which X represents a halogen atom) in combination with an organoaluminum compound.

Examples of the vanadium compound include tetravalent vanadium compounds such as vanadium tetrachloride, vanadium tetrabromide and vanadium tetraiodide, and pentavalent vanadium compounds such as vanadium oxytrichloride and orthoalkylvanadate.
Examples thereof include trivalent vanadium compounds such as vanadium trichloride and vanadium triethoxide. The vanadium compound is used alone or in combination with the titanium compound.

Another example of the catalyst system is a catalyst system in which a reaction product of an organomagnesium compound such as a so-called Grignard compound and a titanium compound and / or a vanadium compound is used as a solid catalyst component, and an organoaluminum compound is combined therewith. Can be illustrated. Examples of the organomagnesium compound include the general formula RMgX,
Magnesium compounds represented by R ₂ Mg, RMg (OR) and the like (wherein R represents an organic residue having 1 to 20 carbon atoms, X represents a halogen atom), ether complexes thereof, or organomagnesium compounds thereof In addition, other organometallic compounds, such as organosodium, organolithium, organopotassium, organoboron, organocalcium, organozinc, and the like, which have been modified and added can be used. Specific examples of the catalyst systems, for example, RMgX-TiCl ₄ type (JP-B 50-39470 discloses), RMgX- phenol -TiCl ₄ system (JP-B 54-12953 discloses), RMg
X-halogenated phenol-TiCl ₄ system (Japanese Patent Publication No. 54-
No. 12954), RMgX—CO ₂ —TiCl ₄ system (JP-A-57-73009), and the like, and a combination of an organoaluminum compound with a solid catalyst component.

As another example of the catalyst system, an inorganic oxide such as SiO ₂ , Al ₂ O ₃ and SiO ₂ .Al ₂ O ₃ and the above titanium and / or vanadium and magnesium are contained as solid catalyst components. A solid substance obtained by contacting with a solid catalyst component is used, and an organoaluminum compound in combination therewith can be exemplified. As the inorganic oxide, the above-mentioned SiO ₂ , Al ₂ O ₃ and SiO ₂ .Al can be used.
_In addition to ₂ O _3, etc., CaO, B ₂ O ₃ , SnO _2, etc. can be mentioned, and a double oxide of these oxides can also be used. As a method of bringing these various inorganic oxides into contact with a solid catalyst component containing titanium and / or vanadium and magnesium, a known method can be adopted. That is, in the presence or absence of an organic solvent such as an inert hydrocarbon, alcohols, phenols, ethers, ketones, esters, amines, nitriles, or a mixture thereof, at a temperature of 20 to 400.
5 minutes to 20 ° C., preferably 50 to 300 ° C.
Although a method of reacting for a time is used, the reaction may be carried out by a method of co-grinding treatment or a method of appropriately combining these. Specific examples of the above catalyst system include:
For example, SiO ₂ --ROH--MgCl ₂ --TiCl ₄ (JP-A-56)
-47407), SiO ₂ -ROR'-MgO-AlC.
l ₃ -TiCl ₄ (JP 57-187305 JP), Si
_{O 2 -MgCl 2 -Al (OR)} 3 -TiCl 4 -Si (OR ') 4
(Japanese Unexamined Patent Publication No. 58-21405), SiO ₂ -TiCl _{4
-R n AlCl 3-n -MgCl 2} -Al (OR ') n Cl 3-n ( _{JP-A-3-35004), SiO 2 -TiCl 4 -R} n AlX
_{3-n -MgCl 2 -Al (OR} ') n Cl 3-n -Si (OR'') n Cl
_4-n (JP-A-3-64306), SiO ₂ -MgCl
_{2 -Al (OR ') n Cl} 3-n -Ti (OR'') 4 -R n AlCl
_3-n (JP-A-3-153707), SiO ₂ -MgC
_{l 2 -Al (OR ') n} Cl 3-n -Ti (OR'') n Cl 4-n -R n Al
Cl _3-n (JP-A-3-185004), SiO ₂ -Ti
_{Cl 4 -R n AlCl 3-n} -MgCl 2 -Al (OR ') n Cl 3-n -
R '' _m Si (OR ''') _n X _{4- (m + n)} (Japanese Patent Application No. 2-41526
5 JP), SiO ₂ -R _n MgX _{2 over n -Al (OR ') n Cl} 3-n
_{-Ti (OR '') n Cl} 4-n -R '''OH-R n AlX 3-n ( Japanese Patent Application No. _{3-94983), SiO 2 -MgCl 2 -Al} (O
_{R ') n Cl 3-n} -Ti (OR'') n Cl 4-n -R''' OH-R n Al
Cl _3-n -Al (OR ') _n Cl _3-n (Japanese Patent Application No. 3-48643) (wherein R, R', R "and R"'represent a hydrocarbon residue) .) Etc. in combination with an organoaluminum compound.

In these catalyst systems, a titanium compound and / or a vanadium compound can be used as an adduct with an organic carboxylic acid ester, and the above-mentioned inorganic solid compound containing magnesium is catalytically treated with the organic carboxylic acid ester. It can be used later. Furthermore, an organoaluminum compound can also be used as an adduct with an organic carboxylic acid ester. Also, in all cases it is possible to use catalyst systems prepared in the presence of organic carboxylic acid esters. Examples of the organic carboxylic acid ester used here include various esters of aliphatic, alicyclic and aromatic carboxylic acids, and preferably an aromatic carboxylic acid ester having 7 to 12 carbon atoms is used.
Specific examples thereof include alkyl esters of benzoic acid, anisic acid, toluic acid such as methyl and ethyl.

The organoaluminum compound used in the present invention together with the solid catalyst component means an organoaluminum compound having at least one aluminum-carbon atom bond in the molecule. For example, (i) the general formula R _m Al (O
R ') _n H _p X _q (wherein R and R'are carbon atoms usually 1
A hydrocarbon group containing 1 to 15, preferably 1 to 4, for example, an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group and the like, and in the case of an alkyl group, methyl, ethyl, propyl, isopropyl, isobutyl, sec. -Butyl, tert-butyl, hexyl, octyl and the like. R and R'may be the same or different. X
Represents a halogen atom, and m, n, p and q are 0 <m ≦ 3, 0 ≦ n <3, 0 ≦ p <3 and 0 ≦ q <3, respectively.
And is a number that satisfies m + n + p + q = 3. ), And (ii) a general formula MAlR ₄ (wherein M is a metal selected from lithium, sodium or potassium and R is the same hydrocarbon group as described above). And complex alkylated products of Group I metal and aluminum in the periodic table.

Examples of the organoaluminum compound belonging to the above (i) include, for example, R _m Al (OR ′) _{3 —m} represented by the general formula (wherein R and R ′ are the same hydrocarbon groups as above. M is preferably 1.5 ≦ m ≦ 3.), A general formula R _m AlX _{3 —m} (wherein R is the same hydrocarbon group as described above, X is a halogen atom, and m is preferably m). 0 <m <3.), R _m AlH _{3 −m} (wherein R is the same hydrocarbon group as described above, and m is preferably a number in the range of 2 ≦ m <3). And R _m Al (OR ′) _n X _q (wherein R and R ′ are the same hydrocarbon groups as described above. X is a halogen atom, and m, n and q are preferably M0 <m ≦ 3, 0 ≦ n <3, 0 ≦ q <3, respectively
And is a number that satisfies m + n + q = 3. ) And the like can be exemplified.
Specific examples of the organoaluminum compound belonging to (i) include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, tri-sec-butylaluminum, tri-aluminum.
Trialkylaluminums such as tert-butylaluminum, trihexylaluminum and trioctylaluminum; trialkenylaluminums; dialkylaluminum alkoxides such as diethylaluminum ethoxide and dibutylaluminum butoxide; alkylaluminums such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide. In addition to sesquialkoxide, partially alkoxylated alkylaluminum having an average composition represented by R _2.5 Al (OR) _0.5, etc .; Dialkylaluminum halides such as diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide; ethyl Aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquichloride Partially halogenated alkyl aluminum such as alkyl aluminum sesquihalide such as bromide; diethyl aluminum hydride, dialkyl aluminum hydride such as dibutyl aluminum hydride and ethyl aluminum dihydride, alkyl aluminum dihydride such as propyl aluminum dihydride, and the like, Partially hydrogenated alkylaluminum; partially aluminumized and halogenated alkylaluminums such as ethylaluminum ethoxy chloride, butylaluminum butoxycyclolide, ethylaluminum ethoxy bromide and the like can be exemplified. Examples of the organoaluminum compound belonging to (ii) above include LiAl (C ₂ H ₅ ) ₄ and LiAl (C ₇ H ₁₅ ).
₄ etc. Further, as the organoaluminum compound similar to (i), an organoaluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom can also be used. Examples of these compounds include (C ₂ H ₅ ) ₂ AlOAl (C ₂ H ₅ ) ₂ and (C ₄ H ₉ ) ₂ AlOAl.
(C ₄ H _{9) 2,} can be exemplified _{(C 2 H 5) 2 AlN} (C 2 H 5) Al (C 2 H 5) 2 and the like. Among these, trialkylaluminum is preferable.

The amount of the organoaluminum compound used during steady operation is not particularly limited, but normally, it can be used in an amount of 0.05 to 1000 mol with respect to 1 mol of the titanium compound.

The polymerization reaction is carried out in the same manner as the polymerization reaction of olefins using a conventional Ziegler type catalyst. That is, the reaction occurs substantially in the gas phase. As olefin polymerization conditions, the temperature is 10 to 200 ° C, preferably 40 to
The temperature is 150 ° C., and the pressure is atmospheric pressure to 70 kgf / cm ² · G, preferably ^{2 to} 60 kgf / cm ² · G. The molecular weight can be adjusted to some extent by changing the polymerization conditions such as the polymerization temperature and the molar ratio of the catalyst, but it is effectively performed by adding hydrogen to the polymerization system. Further, in the present invention, the reactor used for polymerizing or copolymerizing an olefin in a gas phase includes a fluidized bed system and a stirred bed system which are operated substantially in a gas-solid system, and includes a stirrer. It may be either with or without. During steady operation, the olefin, the solid catalyst component, and the organoaluminum compound are constantly introduced into the reaction system, while the produced polymer particles are extracted.

In the polymerization reaction of olefin in a gas phase fluidized bed, a fluidized bed reactor is filled with a resin powder called a seed polymer in advance to start fluidization, and as a raw material mixed gas, a solid catalyst component and a promoter Polymerization reaction is carried out by continuously supplying the organoaluminum compound of. If the above seed polymer is not used, a granular resin will not be generated because the supplied catalyst is difficult to disperse, and thus a fluidized bed will not be formed. used. After filling the seed polymer, nitrogen purge is performed to remove entrained oxygen and the like, and the temperature and pressure are raised to reach the temperature and gas composition of the polymerization conditions. Then, the polymerization is started by supplying the olefin gas, the solid catalyst component and the organoaluminum compound at an amount and a rate separately specified as steady operation. After the seed polymer is added, the solid catalyst component, the organoaluminum compound and the olefin can be supplied in any order. For example, a method of simultaneously supplying a solid catalyst component, an organoaluminum compound and an olefin gas appropriately diluted with an inert gas, a method of starting the supply of the organoaluminum compound first, and then starting the supply of the solid catalyst component or the like, or Any method such as first starting the supply of the solid catalyst component and then starting the supply of the organoaluminum compound and the like can be adopted.

The organic acid used in the present invention has 7 carbon atoms.
The following monovalent carboxylic acids may be mentioned. Specific examples thereof include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid and enanthic acid. In particular, an organic acid that vaporizes before being introduced into a gas phase polymerization reactor is preferable, and those satisfying this condition are formic acid (boiling point 101 ° C), acetic acid (boiling point 119 ° C), propionic acid (boiling point 141 ° C). Etc. In addition to the above, a halogen-substituted product or a hydroxyl-substituted product of a carboxylic acid such as α-chloropropionic acid can also be used.

The organic acid is continuously supplied by any of the following methods. (1) The organic acid itself is supplied while controlling its flow rate. (2) An organic acid is dissolved in a solvent and supplied. As the solvent, for example, a saturated hydrocarbon such as butane, pentane, hexane, and heptane, which does not inhibit the polymerization reaction, is desirable. (3) Nitrogen or the like is blown into the organic acid storage tank, and the gas is supplied in a state of being saturated with nitrogen. At this time, it is necessary to keep the temperature of the storage tank constant. The position of supplying the organic acid may be any position as long as it is within the gas phase polymerization reaction system. In particular, a gas circulation system, for example, between the cooler and the gas phase polymerization reactor is desirable.

The amount of the organic acid supplied is usually in the range of 0.01 to 100 ppm (mol, hereinafter the same) with respect to the supplied olefin gas (the total of ethylene and α-olefin), and preferably 0.1. 10 to 10 ppm. 0.01
When it is less than ppm, the effect of preventing the formation of the sheet polymer is low. On the other hand, if it is more than 100 ppm, the activity-reducing action on the catalyst becomes remarkable and the polymerization activity is reduced, which is not practical. Further, when the supply amount is excessive, the polymer of the product may be odorous, and further, the apparatus may be corroded by the organic acid. Therefore, it is preferable to keep the supply amount to the minimum. For example, during the steady operation, when the production of the sheet-shaped polymer is not observed due to the addition of the organic acid, the supply of the organic acid can be stopped once. In addition,
Since a part of the organic acid reacts with the organoaluminum compound supplied as the cocatalyst and is consumed, the effect cannot be maintained unless a constant amount of the organic acid is supplied when necessary.

[0024]

EXAMPLES The present invention will be specifically described below based on Examples and Comparative Examples, but the present invention is not limited thereto.

<Preparation example of solid catalyst component> 600 in a 500 ml three-necked flask equipped with a stirrer and a reflux condenser.
Add 50 g of SiO ₂ baked at ℃, and add dehydrated hexane 1
60 ml and titanium tetrachloride 2.2 ml were added, and the mixture was reacted under reflux of hexane for 3 hours. After cooling, a hexane solution of diethylaluminum chloride (1 mmol / cc) was added to 30 m.
l was added, and the mixture was reacted again under reflux of hexane for 2 hours and dried under reduced pressure at 120 ° C. to remove hexane. The obtained reaction product is referred to as component (I). Separately, diameter 1 /
Commercially available anhydrous magnesium chloride (10 g) and aluminum triethoxide (4.2 g) were placed in a stainless steel pot with an internal volume of 400 ml containing 25 2-inch stainless steel balls, and ball milling was performed for 16 hours at room temperature under a nitrogen atmosphere. The reaction product was obtained. This is designated as component (II). 5.4 of the above component (II)
g was dissolved in 160 ml of dehydrated ethanol, the total amount of the solution was added to a three-necked flask containing component (I), and the mixture was reacted under reflux of ethanol for 3 hours and dried under reduced pressure at 150 ° C for 6 hours to give a solid. A catalyst component was obtained. The content of titanium in 1 g of the obtained solid catalyst component was 15 mg.

Example 1 Similar to that shown in FIG.
A fluidized bed reactor 1 with a diameter of 25 cm was used. Average particle size 7
12 kg of 50 μm linear low density polyethylene was charged into the reactor as a seed polymer. Next, the pressure in the reaction system was increased to 5 kgf / cm 2 · G with nitrogen gas, and the flow rate of the gas in the system was set using the blower 12 through the fluidized bed reactor 1, the gas circulation pipe 11, the blower 12 and the cooler 13. 88m ³
It circulates at a rate of 85 / hr and the temperature of the circulating gas is adjusted to 85 ° C.
Held in. Adjust the amount of each gas so that the hydrogen / ethylene / butene-1 ratio in the gas phase (molar ratio, the same below) = 0.09 / 1 / 0.41 and the nitrogen concentration 25 mol%, and adjust the total pressure. Was maintained at 20 kgf / cm ² · G. Next, triethylaluminum was supplied as a hexane solution at a rate of 10 g / hr from the cocatalyst supply pipe 5 for 2 hours. The feed rate of triethylaluminum was lowered to 0.8 g / hr, and after 1 hour, the solid catalyst component containing Ti and Mg obtained in the preparation example of the solid catalyst component was fed at a rate of 0.8 g / hr to the catalyst feed pipe 8 To start the polymerization reaction. After the initiation of the polymerization reaction, the rate of polymer formation gradually increased, and after 12 hours, 4 kg / hr.
Reached However, a sheet polymer was formed 5 hours after the initiation of polymerization. The ethylene supply during this period was 8
kg / hr, butene-1 supply amount was 5 kg / hr. Therefore,
A 0.5 wt% hexane solution of glacial acetic acid was supplied to the gas circulation system through the organic acid supply pipe 9 at a rate of 70 ml / hr. After 40 minutes from the start of the feeding, the amount of the sheet polymer discharged was reduced, and after 16 hours, no sheet polymer was found in the discharged particles. The operation continued as it was, and the production rate of the ethylene / butene-1 copolymer discharged through the polymer particle discharge valves 14 and 15 was 4.1 kg / hr. Moreover, the property is M
The FR was 0.91 g / 10 min, the density was 0.9210 g / cm ³ , the appearance was white, and the particles were fine particles having an average particle size of 800 μm. Stable operation was continued even after 48 hours had passed since the start of the catalyst supply. Even after the supply of glacial acetic acid was stopped, stable operation continued after that.

<Second Embodiment> Similar to that shown in FIG.
A fluidized bed reactor with a diameter of 25 cm was used. Average particle size 80
12 kg of 0 μm linear low density polyethylene was charged into the reactor as a seed polymer. Next, the pressure in the reaction system was increased to 5 kgf / cm 2 · G with nitrogen gas, and the gas in the system was fed to the fluidized bed reactor 1, gas circulation pipe 11, blower 1 using the blower 12.
Flow rate of 88 m ³ / h through the route consisting of 2 and cooler 13.
It was circulated at r and the temperature was kept at 85 ° C by adjusting the temperature of the circulating gas. Adjust the amount of each gas so that the hydrogen / ethylene / butene-1 ratio in the gas phase (molar ratio, the same applies below) = 0.10 / 1 / 0.40 and the nitrogen concentration 25 mol%, and adjust the total pressure. Was maintained at 20 kgf / cm ² · G. Next, triethylaluminum was supplied as a hexane solution at a rate of 10 g / hr from the cocatalyst supply pipe 5 for 4 hours. The feed rate of triethylaluminum was reduced to 1.0 g / hr, and after 1 hour, the solid catalyst component containing Ti and Mg obtained in the preparation example of the solid catalyst component was fed at a rate of 0.8 g / hr to the catalyst feed pipe 8 To start the polymerization reaction. Two hours after the initiation of the polymerization reaction, the sheet polymer was discharged. Therefore, a 0.6 wt% hexane solution of propionic acid was supplied to the gas circulation system through the organic acid supply pipe 9 at a rate of 70 ml / hr. The discharge amount of the sheet-shaped polymer decreased 20 minutes after the start of the supply, and the discharge of the sheet-shaped polymer was not observed after the lapse of 16 hours. The operation was continued as it was, and the production rate of the ethylene / butene-1 copolymer discharged through the polymer particle discharge valves 14 and 15 was 4.2 kg / hr. Its properties are MFR 0.81g / 10min and density 0.9225g / cm ³ , its appearance is white and its average particle size is 79
The particles were clean particles of 0 μm.

<Embodiment 3> Similar to that shown in FIG.
A fluidized bed reactor with a diameter of 25 cm was used. The gas in the system was circulated at a flow rate of 88 m ³ / hr through a path composed of the fluidized bed reactor 1, the gas circulation pipe 11, the blower 12 and the cooler 13, and the temperature was kept at 85 ° C. by adjusting the temperature of the circulating gas. Hydrogen / ethylene / butene-1 ratio in gas phase (molar ratio,
The same applies hereinafter) = 0.10 / 1 / 0.40, and nitrogen concentration 2
Adjust the amount of each gas so that the total pressure is 2 mol%.
It was maintained at 0 kgf / cm ² · G. The solid catalyst component containing Ti and Mg obtained in the preparation example of the solid catalyst component was supplied through the catalyst supply pipe 8 at a rate of 0.8 g / hr, and triethylaluminum was prepared as a hexane solution at a rate of 1.0 g / hr. It was supplied from the co-catalyst supply pipe 5, and the polymerization was carried out constantly. The production rate of the ethylene / butene-1 copolymer discharged through the polymer particle discharge valves 14 and 15 was about 4 kg / hr. The polymerization operation was smoothly continued for 14 consecutive days from the initiation of polymerization without the production of a sheet polymer. afterwards,
The ethylene booster (ethylene gas booster, not shown) that had been used up to that point became sick, so I switched to a backup booster, but the reactor operation continued. Immediately after switching the booster, the production rate of the copolymer was reduced to about 1/2, and the production of the sheet polymer was observed. Therefore, a 0.5 wt% hexane solution of glacial acetic acid was supplied to the gas circulation system through the organic acid supply pipe 9 at a rate of 20 ml / hr. After 30 minutes from the start of the supply of glacial acetic acid, the amount of the sheet-shaped polymer discharged decreased and the production rate of the copolymer gradually recovered. After 22 hours from the start of feeding, no sheet-shaped polymer was found in the discharged polymer particles. After that, the operation similarly continued smoothly, and the production rate of the ethylene / butene-1 copolymer discharged through the polymer particle discharge valves 14 and 15 was 3.9 kg / hr. Moreover, the property is MFR.
It was 0.88 g / 10 min, the density was 0.920 g / cm ³ , the appearance was white, and the particles were fine particles having an average particle size of 780 μm. Stable operation was continued even 60 hours after the start of the supply of glacial acetic acid. After that, the supply of glacial acetic acid was stopped, but the stable operation was continued.

Comparative Example 1 The same procedure as in Example 1 was carried out except that glacial acetic acid was not supplied. 36 hours after the catalyst supply was started, the operation was stopped because the pipe for extracting polymer particles from the fluidized bed reactor was clogged due to the production of the sheet polymer.

[0030]

In the operation of the gas phase polymerization reactor for olefins, the following effects can be obtained by adding a trace amount of organic acid to the reaction system. (1) It is possible to prevent the production of a sheet-shaped polymer in the reactor. (2) As a result, the polymer particle extraction pipe is not clogged, and stable operation can be continued.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a gas phase polymerization reaction device.

[Explanation of symbols]

 1 fluidized bed reactor 2 upper space area 3 fluidized bed area 4 gas dispersion plate 5 co-catalyst supply pipe 6 hydrogen supply pipe 7 olefin supply pipe 8 catalyst supply pipe 9 organic acid supply pipe 10 nitrogen supply pipe 11 gas circulation pipe 12 blower 13 Cooler 14, 15 Polymer particle discharge valve

Claims (2)

[Claims] 1. A method of supplying a catalyst comprising a solid catalyst component containing at least titanium and / or vanadium and magnesium and an organoaluminum compound to a reactor to constantly polymerize or copolymerize an olefin in a gas phase. , A method for operating an olefin vapor phase polymerization reactor characterized by preventing the formation of a sheet polymer in the reactor by supplying an organic acid into the reaction system. 2. The method for operating an olefin vapor phase polymerization reactor according to claim 1, wherein the organic acid is a carboxylic acid having 7 or less carbon atoms.