JP2003286302A - Method of feeding polymerization catalyst and method of manufacturing polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a polymer capable of manufacturing a polymer without decreasing productivity using a method of feeding a polymerization catalyst which has little concern of inducing scale deposition on the inner wall of a reactor. <P>SOLUTION: In this method of polymerizing a monomer by feeding the polymerization catalyst to the liquid phase 9 in which the monomer fed to the inside of the reactor body 4 of the reactor 2 is dissolved in a solvent, the catalyst is fed under the surface 92 of the liquid phase 9. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for supplying a polymerization catalyst for polymerizing a monomer, and a method for producing a polymer using this method.

[0002]

2. Description of the Related Art The polymerization of monomers by solution polymerization is usually
It is carried out in the presence of a polymerization catalyst. Specifically, first, a monomer and a solvent in which the monomer is soluble are charged into a reactor, and then the reaction solvent is refluxed using a reflux condenser for heat removal, and a polymerization catalyst is used. Was carried out by feeding from the upper part (gas phase part) of the reactor toward the liquid surface of the liquid phase part in which the monomer was dissolved in the solvent.

However, when the polymerization is carried out by this conventional method, the monomer which should exist only in the liquid phase part floats in the gas phase part due to the condensation of the solvent vapor in the reflux condenser. This may come into contact with the residue of the polymerization catalyst present in the gas phase, deposit as scale (microgel), and adhere to the inner wall of the reactor (particularly the inner wall of the upper side part).

If this scale adheres to and accumulates on the inner wall of the reactor for each batch, it may adversely affect the polymerization reaction in the reactor and the scale may be separated from the inner wall of the reactor. When mixed in the liquid phase part, various properties of the polymer recovered from the liquid phase part (here, the reaction solution containing the polymer) may be adversely affected. For this reason, when scale adheres to the inner wall of the reactor, the polymerization reaction is temporarily stopped and the inside of the reactor must be maintained. As a result, there is a problem that the productivity of the polymer finally obtained is extremely poor.

[0005]

An object of the present invention is to provide a method for supplying a polymerization catalyst which is less likely to deposit scale on the inner wall of a reactor. Further, the present invention is
It is also an object of the present invention to provide a method for producing a polymer, which can produce a polymer without lowering productivity by using such a supply method.

[0006]

Means and Actions for Solving the Problems
As a result of earnest studies to achieve the above object, it was found that the above object can be achieved by supplying a polymerization catalyst by a specific method, and the present invention has been completed.

That is, the method for supplying a polymerization catalyst according to the present invention is characterized in that a liquid phase portion containing at least a monomer and a solvent charged in a reactor is polymerized from the lower side of the liquid surface of the liquid phase portion. It is characterized by supplying a catalyst.

According to the present invention, there is no residue of the polymerization catalyst in the gas phase part of the reactor, and a single amount from the liquid phase part is added to the gas phase part as the solvent vapor is condensed in the reflux condenser. Even if the body floats, the monomer floating in the gas phase does not come into contact with the polymerization catalyst. Therefore, the scale is effectively prevented from depositing and adhering to the inner wall of the reactor (in particular, the inner wall of the upper side portion).

In the supply method of the present invention, it is preferable to supply the polymerization catalyst by using an inner nozzle projecting inside the reactor. Further, it is preferable to use an inner nozzle having a protruding length of 100 mm or more.

The method for producing a polymer according to the present invention is characterized by polymerizing a monomer by using the above-mentioned feeding method.

According to the present invention, since there is little risk of depositing scale on the inner wall of the reactor, the polymer can be produced without lowering the productivity.

[0012] In each of the above-mentioned inventions, the reactor main body in which the stirring blades which are rotationally driven by the driving means via the rotary shaft are arranged, and the liquid surface of the liquid phase portion to be charged inside the reactor main body It can be realized by using a reactor having a lower inner nozzle for supplying a polymerization catalyst protruding inside the reactor main body.

By carrying out each of the inventions using such a reactor, a scale adhesion preventing effect can be expected.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The monomer applicable to the present invention is not particularly limited, and examples thereof include conjugated dienes or a mixture of aromatic vinyl and conjugated dienes. Examples of the polymer obtained by polymerizing such a monomer include a conjugated diene-based (co) polymer and an aromatic vinyl-conjugated diene-based copolymer. Among them, the method of the present invention is suitable when the polymer is an aromatic vinyl-conjugated diene-based copolymer, and is particularly suitable when it is SBR (styrene-butadiene rubber).

Examples of the aromatic vinyl include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, pt-butylstyrene, 1,3-dimethylstyrene, vinylnaphthalene and vinylanthracene. Of these, styrene is preferable. These aromatic vinyls may be used alone or in combination of two or more.

As the conjugated diene, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene,
2,4-hexadiene and the like can be mentioned. Above all 1,3
-Butadiene and isoprene are preferred, and 1,3-butadiene is particularly preferred. These conjugated dienes may be used alone or in combination of two or more.

When a mixture of aromatic vinyl and a conjugated diene is used as the monomer, the content ratio of the aromatic vinyl and the conjugated diene in the mixture is 5:95 by weight, respectively.
It is in the range of 95: 5, preferably 20:80 to 80:20.

Examples of the solvent used for the polymerization include aliphatic hydrocarbons (n-pentane, n-hexane, isooctane, etc.), alicyclic hydrocarbons (cyclopentane, cyclohexane, etc.), aromatic hydrocarbons (benzene, toluene). Etc.), hydrocarbon solvents such as ethers (tetrahydrofuran, dioxane, etc.), or water.

The solvent is usually used in an amount ratio such that the monomer concentration is about 1 to 30% by weight.

The method of polymerization in the present invention is not particularly limited, but solution polymerization or emulsion polymerization is preferable, and solution polymerization is particularly preferable.

The polymerization catalyst used for solution polymerization is
Examples of the catalyst include a catalyst in which a metal compound and an organometallic compound such as organoaluminum are combined, an organometallic complex, and an organic alkali metal.

Examples of the metal compound include acetylacetone salts, naphthenates, cyclopentadienyl compounds, cyclopentadienyldichloro compounds, etc. of respective metals such as nickel, cobalt, titanium and iron.

Examples of the organic aluminum include alkyl aluminum (triethyl aluminum, triisobutyl aluminum, etc.), halogenated alkyl aluminum (diethyl aluminum chloride, ethyl aluminum dichloride, etc.), hydrogenated alkyl aluminum (diisobutyl aluminum hydride, etc.) and the like.

Examples of the organometallic complex include γ-dichloro-π-benzene complex of each metal such as rhodium, palladium, ruthenium and rhenium, dichloro-tris (triphenylphosphine) complex, hydrido-chloro-tris (triphenylphosphine). Examples thereof include complexes.

As the organic alkali metal, n-butyllithium (n-BuLi), sec-butyllithium, t
-Monolithium compounds such as butyllithium, hexyllithium, phenyllithium and stilbenelithium; dilithiomethane, 1,4-dilithiobutane, 1,4
-Dilithio-2-ethylcyclohexane, 1,3,5-
Multifunctional organolithium compounds such as trilithiobenzene; JP-A-7-2916 and JP-A-7-53616.
Examples include tertiary amino group-containing organolithium compounds disclosed in Japanese Patent Publication No. JP-A No. 2003-242242; sodium naphthalene, potassium naphthalene, and the like. Among them, organic lithium compounds are preferable,
Monoorganolithium compounds are particularly preferred. These organic alkali metals may be used alone or in combination of two or more.

The amount of the polymerization catalyst used is usually about 0.000001 to 0.01 times the molar ratio of the monomer.

A polar compound may be used together in the solution polymerization. As the polar compound, an ether compound; a tertiary amine compound such as tetramethylethylenediamine (TMEDA), trimethylamine, triethylamine, pyridine, quinuclidine; potassium-t-amyl oxide,
Examples thereof include alkali metal alkoxide compounds such as potassium-t-butyl oxide; phosphine compounds such as triphenylphosphine. These polar compounds are
Each may be used alone or in combination of two or more.

The amount of the polar compound used is equimolar or more, preferably 1 to 20 times the molar amount of the polymerization catalyst.

The polymerization catalyst used in emulsion polymerization is
Inorganic peroxides such as hydrogen peroxide or potassium persulfate, or organic peroxides such as cumene hydroperoxide, diisopropyl benzene hydroperoxide or patamentane hydroperoxide,
Examples thereof include a redox-based catalyst in which a reducing agent such as a divalent iron salt or tetraethylene pentaamine is combined.

In emulsion polymerization, the solvent is usually
Water is used.

In the present invention, at least the monomer and the solvent are charged inside the reactor to form a liquid phase portion, and the polymerization catalyst is supplied from below the liquid surface of the liquid phase portion. In order to realize such a method of the present invention, for example, FIG.
The reactor 2 shown in can be used. FIG. 1 is a schematic sectional view showing a reactor that can be used in the method of the present invention.

As shown in FIG. 1, the reactor 2 used in this embodiment has a reactor body 4 in which a polymerization reaction is carried out.
Inside the reactor body 4, a rotary shaft 6 which is rotatable and driven is arranged, and the rotary shaft 6 is connected to a driving means (not shown) such as a motor. A stirring blade 8 is attached to the rotating shaft 6. As the stirring blade 8, for example,
Inclined paddle blades, full zone blades, Maxblend blades, helical ribbon blades, etc. can be used. By rotating the rotary shaft 6, the liquid phase portion 9 charged inside the reactor body 4 is stirred and mixed.

In the present embodiment, an inner nozzle 42 is provided on the inner wall surface 4a of the lower side portion of the reactor body 4 so as to project inside the reactor body 4. The arrangement position of the inner nozzle 42 is the inner wall surface 4a of the lower side portion of the reactor body 4.
However, the lower bottom inner wall surface 4b may be used. Also,
The number of the inner nozzles 42 arranged is not limited to one, and may be two or more. When a plurality of inner nozzles 42 are arranged, the protrusion lengths L may be the same or different. The shape of the inner nozzle 42 may be cylindrical or prismatic. When the nozzle shape is cylindrical, the diameter of the nozzle cross section is usually about 15 to 20 mmφ. The protruding length L of the inner nozzle 42 is not particularly limited, but is preferably 100 mm or more. Projection length L
When the thickness is 100 mm or more, the polymerization catalyst can be supplied from the central portion of the liquid phase portion 9, and the polymerization catalyst can be uniformly introduced into the liquid phase portion 9.

Then, at least the monomer and the solvent are charged into the interior of the reactor body 4 to form the liquid phase portion 9, and the polymerization is performed through the inner nozzle 42 while adjusting the temperature in the reaction system to a predetermined temperature. Supply catalyst. At this time, since the reaction heat is removed by the reflux condenser (not shown), the solvent (gas) evaporated from the liquid surface 92 moves toward the condenser. At this time, the monomer, which should be present only in the liquid phase portion 9, easily floats in the gas phase portion. Therefore, the present invention is particularly preferably used when the reaction heat is removed by the reflux condenser. To be During the polymerization reaction, the rotary shaft 6 is usually driven to rotate, and the stirring blades 8 attached to the rotary shaft 6 continue to stir the liquid phase portion 9 charged inside the reactor body 4.

By supplying the polymerization catalyst through the inner nozzle 42, the polymerization catalyst is supplied to the liquid phase portion 9 from below the liquid surface 92 of the liquid phase portion 9 in the reactor body 4. As a result, there is no residue of the polymerization catalyst in the gas phase part 5 of the reactor body 4, and the liquid phase part in the gas phase part 5 is accompanied by the condensation of the solvent vapor in the reflux condenser (not shown). Even if the monomer floats from 9, the monomer floating in the gas phase part 5 does not come into contact with the polymerization catalyst. For this reason,
The scale is effectively prevented from depositing and adhering to the upper side inner wall 4c of the reactor body 4.

Generally, at the outlet of the reflux condenser, the pressure is often lower than that in the vapor phase portion 5 by a pressure reducing means such as a compressor. In that case, the pressure from the liquid phase portion 9 is reduced. Since the amount of the suspended particles of the monomer increases, the effect of preventing scale adhesion according to the present invention becomes more remarkable.

The polymerization catalyst supplied to the liquid phase part 9 may be a solution of a solvent, and specifically, a solution of about 15 to 20% by weight is preferable.

The supply time of the polymerization catalyst is preferably 0.0
It is about 5 to 0.13 hours.

The temperature in the reaction system when the polymerization catalyst is supplied is
It is preferably about 40 to 50 ° C.

The polymerization catalyst can be supplied by, for example, pump feeding or pressure feeding with an inert gas.

After the completion of the polymerization reaction, alcohols such as methanol and isopropanol as a reaction terminator are added by a conventional method to terminate the polymerization reaction, and an antioxidant (stabilizer) and a crumbing agent are added. After that, the solvent is removed by a method of heating the solution to dry the solvent or a method such as steam stripping, and the produced polymer can be recovered.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments and can be implemented in various modes without departing from the scope of the present invention. Of course.

[0043]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. Unless otherwise stated, parts and% are based on weight.

Example 1 In this example, one cylindrical inner nozzle (projection length L100 mm, cross-sectional diameter 20 mmφ) 42 projects on the inner wall surface 4a of the lower side of the reactor body 4 into the reactor body 4. The reactor 2 shown in FIG. 1 having the configuration as described above was used.

Inside the reactor body 4 of the reactor 2 as described above, 10 monomers (23 parts of styrene and 77 parts of butadiene) were added.
After forming 0 parts and 1170 parts of solvent (cyclohexane) to form the liquid phase part 9, while maintaining the internal temperature at 60 ° C. and condensing the solvent vapor by the reflux condenser, the polymerization catalyst ( n-BuL
0.0015 parts of a 20% cyclohexane solution of i) was supplied by pump feed. That is, the polymerization catalyst was supplied from below the liquid surface 92 of the liquid phase portion 9 to carry out the polymerization reaction. During the polymerization reaction, the rotary shaft 6 was driven to rotate, and the stirring of the liquid phase portion 9 was continued by the stirring blade 8 attached to the rotary shaft 6. After 3 hours, methanol was added to deactivate the catalyst to terminate the polymerization reaction (polymerization conversion ratio 100
%), And the adhesion of scale (microgel) to the inner wall 4c of the upper side of the reactor body 4 was visually evaluated. As a result, almost no scale adhered. Therefore, it was confirmed that it is not necessary to regularly maintain the inside of the reactor body 4 and the productivity of the polymer is not reduced.

COMPARATIVE EXAMPLE 1 In this example, the inner nozzle 42 was not provided and the reactor body 4
Using a reactor provided with a catalyst inlet at the upper part of the reactor, the polymerization catalyst was supplied from the catalyst inlet provided at the upper part of the reactor main body 4 through the gas phase part 5 toward the liquid surface 92 of the liquid phase part 9. .
Other than these, the polymerization reaction was carried out in the same manner as in Example 1,
The scale adhesion to the inner wall of the upper side of the reactor body 4 was visually evaluated. As a result, it was confirmed that a scale having a thickness of 10 cm and a width of 1 m was attached. Therefore, it is necessary to regularly maintain the inside of the reactor main body 4, and it seems that the productivity of the polymer is lowered.

[0047]

As described above, according to the present invention, there is provided a method for supplying a polymerization catalyst which is less likely to deposit scale on the inner wall of the reactor. Further, according to the present invention, there is provided a method for producing a polymer, which is capable of producing a polymer without lowering productivity by using such a supplying method.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a reactor that can be used in the method of the present invention.

[Explanation of symbols]

2 ... Reactor 4 ... Reactor body 42 ... Inner nozzle 5 ... Gas phase 6 ... Rotation axis 8 ... Stirrer 9 ... Liquid phase part 92 ... Liquid level

Claims (5)

[Claims] 1. A polymerization catalyst, characterized in that a polymerization catalyst is supplied to a liquid phase portion containing at least a monomer and a solvent charged inside a reactor from below a liquid surface of the liquid phase portion. Supply method. 2. The method for supplying a polymerization catalyst according to claim 1, wherein the polymerization catalyst is supplied by using an inner nozzle protruding inside the reactor. 3. The method for supplying a polymerization catalyst according to claim 2, wherein an inner nozzle having a protruding length of 100 mm or more is used. 4. A method for producing a polymer, in which a monomer is polymerized by using the feeding method according to any one of claims 1 to 3. 5. A reactor main body in which a stirring blade rotationally driven by a driving means via a rotary shaft is arranged, and below a liquid surface of a liquid phase portion to be charged inside the reactor main body. And a inner nozzle for supplying a polymerization catalyst protruding inside the reactor body.