JPH02225503A - Polymerization of olefin - Google Patents

Abstract

PURPOSE:To eliminate the coagulation and stoppage occurring when a highly concentrated catalyst slurry is fed to the polymerization system by adding a polyvalent metal salt of a specified organic acid to a slurry or mud comprising a solid catalyst containing a transition metal and an inert solvent. CONSTITUTION:0.0001-1wt.% polyvalent metal salt of an organic acid selected from a polyvalent metal salt of an alkylsalicylic acid and a polyvalent metal salt of a dialkyl ester of a sulfonated aliphatic dicarboxylic acid is added to a slurry or mud comprising a solid catalyst containing a compound of Group IV-VI transition metal of the periodic table, e.g. TiCl3. This slurry or mud is supplied to a storage tank 1 equipped with an agitator, sent through a feed valve 2, and fed to the reactor 3 together with an olefin from a line 4. This olefin is polymerized in the presence of an organoaluminum compound and a polyelectrolyte fed through lines 5 and 6.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing polyolefins.

More particularly, the present invention relates to an improved method for supplying solid catalyst components.

[Conventional technology]

BACKGROUND ART A method of polymerizing olefins, such as ethylene, propylene, etc., using a solid catalyst containing a transition metal component is widely used. Polymerization methods for these olefins include slurry polymerization in an inert hydrocarbon solvent, bulk polymerization in a liquefied monomer such as liquefied propylene, and polymerization in a gas phase in the substantial absence of a liquid phase. There are gas phase polymerization methods that are carried out in

In any case, in order to effectively use a solid catalyst component in a polymerization reaction, it is necessary to stably supply the catalyst into the polymerization system and to uniformly disperse it within the reactor. Methods such as dispersing it at a relatively low concentration in an active solvent and supplying it in the form of a slurry have been adopted.

In particular, in bulk polymerization and gas phase polymerization, an inert solvent is supplied into the polymerization system, which reduces polymerization efficiency and deteriorates the powder properties of the resulting polymer, making stable operation difficult. Moreover, it is a big disadvantage in terms of manufacturing costs, such as the need for a drying process and a recovery/purification process for the inert solvent used.

For this purpose, there is a method in which the catalyst is dispersed at a fairly high concentration in an inert solvent, in the form of a slurry, or the catalyst is precipitated in an inert solvent and supplied in the form of a mud.

However, when supplying such a highly concentrated catalyst slurry or mud, agglomeration of catalyst particles and clogging in piping tend to occur, making stable supply sometimes impossible.

[Problems to be Solved by the Invention] In view of these circumstances, the present invention aims to solve the agglomeration and clogging phenomena that occur when a highly concentrated catalyst slurry is supplied into a polymerization system, and to achieve stable operation for olefin polymerization. The purpose is to provide a method.

[Means for Solving the Problems] The present inventors have solved the above-mentioned problems. It was discovered that the problem could be easily solved by adding , leading to the present invention.

That is, in the present invention, in the method of polymerizing olefin using a solid catalyst containing a transition metal component, when a slurry or mud consisting of the solid catalyst and a solvent inert thereto is supplied to a reactor, the slurry or mud is An olefin polymerization method characterized in that a polyvalent metal salt of an organic acid selected from a polyvalent metal salt of an alkyl salicylic acid and a polyvalent metal salt of a dialkyl ester of a sulfonated aliphatic dicarboxylic acid is added to the mud. be.

The present invention will be explained in detail below.

The transition metal component-containing solid catalyst component in the present invention is a transition metal component in a so-called Ziegler catalyst used for olefin polymerization, such as titanium, vanadium,
It is a solid catalyst containing one or more transition metal compounds of Groups 1 to 2 of the periodic table, such as zircon and chromium. Specifically, it is a transition metal compound supported on a carrier, or a low-valent solid that is insoluble in hydrocarbons obtained by reducing a transition metal compound. Among these, particularly preferred are solid magnesium compounds, titanium compounds, and known carrier-supported catalyst components containing halogens, and titanium trichloride obtained by reducing titanium tetrachloride with metal aluminum or organometallic compounds as the main component. etc.

As a material containing titanium trichloride as a main component, conventionally known titanium trichloride can be used. For example, titanium trichloride is activated by ball milling; titanium trichloride is further extracted with a solvent; β-type titanium trichloride is treated with a complexing agent such as an ether, and then titanium tetrachloride is used. Titanium trichloride with an atomic ratio of aluminum to titanium of 0.315 or less: In the presence of ethers, titanium tetrachloride is treated with an organoaluminum compound to form a liquid, which is further heated to form a solid to reduce the aluminum content. Examples include titanium trichloride whose atomic ratio to titanium is 0.15 or less.

Among these titanium trichlorides, particularly preferred are titanium trichlorides having an aluminum content of 0.15 or less, preferably 0.1 or less, more preferably 0.102 or less in terms of the atomic ratio of aluminum to titanium, and containing a complexing agent. It is something to do.

The organoaluminum compound used as a cocatalyst for the transition metal-containing solid catalyst component has the general formula AI R, x
It is a compound represented by s- (wherein R is a hydrocarbon group having 1 to 20 carbon atoms, X represents a halogen, and n represents a number of 3≧n>1.5).

In the case of a titanium-containing solid catalyst component or a carrier-supported catalyst component containing a solid magnesium compound, it is preferable to use AIR or a mixture of AIRI and AIR,X.

In addition, when the titanium-containing solid catalyst component has titanium trichloride as the main component, it is preferable to use AIR,X,
Particularly preferred are diethylaluminum chloride, di-n-propyl aluminum chloride, diethylaluminium chloride, and di-n-octylaluminum chloride.

The titanium trichloride and organoaluminum compound shown above are generally used in a molar ratio of organoaluminium compound/titanium trichloride of 1 to 30, preferably 2 to 15.

In the present invention, the above-mentioned catalyst may be used as it is, but it is preferable to use a catalyst made of titanium trichloride and an organoaluminum compound prepolymerized with a small amount of α-olefin as a pretreatment. can.

The preliminary polymerization method is to add titanium trichloride and an organoaluminum compound to an inert solvent such as hexane or heptane, and to this add an α-olefin such as propylene, ethylene, butene-1, or a mixture thereof. It is sufficient to polymerize it. This pretreatment is generally referred to as prefiff1 polymerization, and known polymerization conditions can be used as they are. The polymerization temperature is preferably 30 to 70°C. The polymerization rate is preferably as high as possible per unit weight of titanium trichloride, but from an equipment or economic point of view, it is 0.1 to 1
The range is generally 00g7g - TlCl3. Furthermore, a molecular weight regulator such as hydrogen may be added during prepolymerization. Further, it is preferable that the pre-Ha reaction is carried out uniformly in a batch manner. This secondary polymerization is effective in improving polymer properties such as bulk density.

In the present invention, the raw material olefin to be subjected to polymerization may be a single olefin such as ethylene, propylene, butene-1,3-methylbutene-1,4-methylpentene-1,1,3-butadiene, or hexene-1. Or a mixture of two or more types can be mentioned.

The polymerization method can be carried out by known slurry polymerization, bulk polymerization carried out in a liquefied monomer, gas phase polymerization, or the like. These polymerization methods may be either batchwise or continuous, and the reaction conditions are usually 1 to 100 atmospheres and a temperature of 0 to 120°C, preferably 50 to 110°C.

In slurry polymerization, inert hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons used in normal olefin polymerization are used as polymerization media, including normal hexane, normal heptane, cyclohexane, benzene, and toluene. is preferably used. Moreover, propylene itself can also be used as a solvent.

Further, as a method for controlling the molecular weight of the produced polymer, a known molecular weight controlling agent such as hydrogen or diethylzinc can be appropriately added to the polymerization reaction.

The gist of the present invention is to cause a polyvalent metal salt of an organic acid to be present in the slurry or mud in the catalyst supply step when performing the above-mentioned olefin polymerization.

Examples of such polyvalent metal salts include polyvalent metal salts of organic acids selected from polyvalent metal salts of alkyl salicylic acids and sulfonated dialkyl esters of aliphatic dicarboxylic acids. Examples of polyvalent metals include alkaline earth metals, magnesium, copper, zinc, cadmium, aluminum, lead,
Examples include chromium, molybdenum, and manganese.

Examples of such polyvalent metal salts of organic acids include diisopropylsalicylic acid and long chain alkyl groups, e.g.
Salts of alkyl-substituted aromatic carboxylic acids, such as salts of alkylsalicylic acids, substituted with alkyl groups having 18 carbon atoms; salts of dialkyl esters of sulfonated aliphatic dicarboxylic acids, such as salts of dioctyl esters of sulfosuccinic acid; be.

Chromium salts of alkylsalicylic acids having at least one alkyl substituent having 8 or more carbon atoms of metals with atomic numbers 21 to 29, such as alkylsalicylic acids having at least one alkyl group having 14 to 18 carbon atoms. are preferred polyvalent metal salts, and also salts of the alkylsalicylic acids and salts of divalent metals and dialkyl esters of sulfodicarboxylic acids, such as the calcium salt of the dioctyl ester of sulfosuccinic acid or the calcium salt of the didecyl ester of sulfosuccinic acid. Mixtures with are particularly preferred.

These polyvalent metal salts may be used alone or as a mixture of two or more types, and in particular, polyvalent metal salts of alkyl salicylic acids and polyvalent metal salts of dialkyl esters of sulfonated aliphatic dicarboxylic acids are used as a mixture. is particularly preferable.

Historically, a preferred embodiment of the present invention is the case where it is used in combination with a polymer electrolyte. Such polymer electrolytes include polymers of unsaturated carboxylic acids or substitutes thereof, such as stearyl methacrylate/methacrylic acid copolymer or β-hydroxyethyl methacrylate/stearyl methacrylate/methacrylic acid copolymer, or ethylene. imine polymer, 2-methyl-
Polymer of 5-vinylpyridine, copolymer of 2methyl-5-vinylpyridine/mixture with lauryl methacrylate and stearyl methacrylate, lauryl methacrylate/
Stearyl methacrylate/methyl methacrylate/2
Examples include polymers of organic bases such as -methyl-5-vinylpyridine copolymers, and copolymers of these organic bases with unsaturated carboxylic acids or substituted products thereof;
A copolymer of -methyl-5 vinylpyridine and an alkyl methacrylate ester (alkyl group having 16 to 18 carbon atoms) is preferably used.

The amount of the polyvalent metal salt of the organic acid added is 1% by weight or less, preferably 0.0% by weight, based on the catalyst slurry or mud.
001-1% by weight, 1 more preferably 0.001-o
, i% by weight, and this amount of addition sufficiently exhibits its effect, and generally no influence on polymerization performance is observed.

[Example] The present invention will be described below with reference to Examples.
It is not limited to this unless it departs from the gist.

(^) Preparation of solid titanium trichloride 5.155 I of purified toluene was placed in an autoclave with a volume of 109 that was sufficiently purged with nitrogen at room temperature, and while stirring,
-butyl ether 651 g (5 mol), titanium tetrachloride 9
49g (5 moles), diethylaluminum chloride 2
g[ig (2.4 mol) was added to obtain a brown homogeneous solution.

Next, the temperature was raised to 40°C, and after 30 minutes, precipitation of purple fine particles was observed, but the temperature remained unchanged for 2 hours.
The temperature was maintained at 0°C.

Next, 315 g of titanium tetrachloride was added, and the temperature was raised to 98°C. After being held at 98° C. for about 1 hour, the granular purple solid was separated and washed with n-hexane to yield about 800 g of solid titanium trichloride.

([3) Production of propylene polymer-containing titanium trichloride (pretreatment) ``Pour purified n-hexane 5Q into a 1051 autoclave that was sufficiently purged with nitrogen, and add 195 g of diethylaluminium chloride and the solid trichloride obtained in (^) above. After charging 250g of titanium chloride (Ti1l), the temperature was set at 40°C.
While stirring, 250 g of propylene gas was blown into the gas phase for about 60 minutes for contact treatment.

The solid component was then allowed to settle, and the supernatant liquid was removed by decantation and washed several times with rhohexane to obtain a propylene polymer-containing solid titanium trichloride.

(C) Polymerization of propylene In the presence of the catalyst component obtained in (B) above, an internal volume of 1. ．．
Bulk polymerization of liquefied propylene was carried out continuously in a 6 m3 polymerization tank.

Polymerization temperature was 60°C, pressure 24-25 kg/cII'
-With GF, the gas phase hydrogen a degree in the tank is 2.5 mol% during polymerization
It was prepared as follows.

The titanium trichloride type catalyst obtained in (B) above was made into a 20% by weight slurry in n-hexane, and added to
20% by weight of chromium salt of alkyl salicylic acid with 18 alkyl groups, 10% by weight of calcium salt of sulfo:/'% phosphoric acid di-2-ethylhexyl ester, polyelectrolyte (carbon of 2-methyl-5 vinylpyridine and methacrylic acid) Copolymer with alkyl ester of number 17) 45m11
Additives consisting of 1% i and 25% by weight of xylene were added to the catalyst slurry at a weight of 0.0030%.

This slurry is stored with a stirrer at +511 as shown in Figure 1.
Introduced to J 1, passed through mud flood valve 2, and connected to line 4.
3.0 g/hr of catalyst as TlCl 3 was fed to reactor 3 along with propylene from.

On the other hand, from another line 5.6, cocatalyst diethyl aluminum monochloride 20g/hr, methyl methacrylate 0
．． 6 g/hr was supplied continuously. The polymerization rate of polypropylene in this drying process was 45 kg/hr.

MFI was -5g/LOmin.

The above continuous operation was continued for 72 hours, but the catalyst slurry was constantly supplied, and the temperature, pressure, and production amount of the reactor were stable.

Furthermore, after the operation was completed, the equipment and piping were opened and inspected, but no catalyst adhesion or deposits were found.

Although titanium trichloride, which is a particularly preferred form of the present invention, has been described above as a solid catalyst component, the same applies to the case where other transition metal component gold-platinum solid catalyst components are used.

Comparative Example Regarding the supply of solid catalyst components, propylene polymerization was carried out in the same manner as in the example except that the polyvalent metal salt additive of an organic acid was not added.

However, after about 10 hours after the start of operation, steady supply of catalyst became impossible, and the catalyst mud supply valve eventually became clogged.

[Effects of the Invention] As explained above, the method of the present invention does not cause unstable flow or blockage in the solid catalyst supply channel or the metering pump, which was conventionally seen in the slurry method and the mud method. This makes it possible to drive with ease.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating an example of a polymerization apparatus used in the present invention,

Claims (1)

[Claims] (1) In a method of polymerizing olefin using a solid catalyst containing a transition metal component, when a slurry or mud consisting of the solid catalyst and an inert solvent is supplied to the reactor, the slurry or mud is On the other hand, an olefin polymerization method characterized in that a polyvalent metal salt of an organic acid selected from a polyvalent metal salt of an alkyl salicylic acid and a polyvalent metal salt of a dialkyl ester of a sulfonated aliphatic dicarboxylic acid is added.