JPH1171419A - Production of styrene-based polymer, initiator for polymerization of styrenic monomer and styrene-based polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to perform a living polymerization in a system under bulk radical polymerization conditions and to thereby obtain a styrene- based polymer having good heat stability by polymerizing a styrenic monomer in the presence of an initiator comprising an organoaluminum compound or comprising an organoaluminum compound and a specified alkyl alkali metal compound or an alkyl alkaline earth metal compound. SOLUTION: Styrenic monomers are polymerized at a temp. of 80-250 deg.C in the presence of a polymerization initiator comprising an organometallic compound represented by formula: (R<1> )m AlHn (wherein R<1> is a hydrocarbon compound residue; m+n=3; and 0<=n<3), an organometallic compound represented by the formula: (R<1> )m AlHn and R<2> M<1> and/or R<2> OM<1> (wherein R<2> is a hydrocarbon compound residue; and M<1> is at least one alkali metal selected among Li, Na and K) and an organometallic compound represented by the formula: (R<1> )m AlHn and (R<3> )2 M<2> and/or R<3> OM2 R<3> and/or (R<3> O)2 M<2> (wherein R<3> is a hydrocarbon compound residue; and M<2> is an alkaline earth metal such as Mg, Ca, Sr or Ba).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a styrene-based polymer, a styrene-based monomer polymerization initiator used in the production method, and a styrene-based polymer obtained by the production method. More specifically, the present invention relates to a method for producing a novel styrenic polymer capable of allowing polymerization to proceed in a living manner without causing a transfer reaction and termination reaction at the time of polymerization as compared with a conventional radical polymerization method, and a novel method used in the production method. The present invention relates to a styrene-based monomer polymerization initiator and a new styrene-based polymer obtained by a method for producing the same.

[0002]

2. Description of the Related Art Styrene polymers typified by polystyrene have been industrially produced by a radical polymerization method for a long time. However, as is well known in the radical polymerization method, since a termination reaction such as a recombination reaction of a growing radical or a transfer reaction to a solvent or a monomer occurs, it is difficult to control a polymer structure, for example, a molecular weight distribution or a polymer terminal structure. there were. In addition, block polymers and star polymers could not be produced because they were not living polymerizations.

[0003] As a method of solving these inconveniences,
There is a living anion polymerization method of a monomer represented by styrene or butadiene. For example, anionic polymerization of styrene using butyllithium, a general-purpose initiator,
Since a polymerization system without a transfer reaction and a termination reaction, so-called living polymerization, proceeds, an extremely monodispersed polymer is obtained. Further, by utilizing the reactivity of the growing terminal of the living polymer, it is possible to obtain various polymers having a controlled structure which cannot be obtained by radical polymerization, such as a block polymer with butadiene.

[0004] However, the living anionic polymerization method of styrene has not been used industrially, except for special cases, in spite of obtaining such a very attractive resin material. One of the reasons is that because the living anionic polymerization is a solution polymerization, the production yield is low,
In addition, since a large-scale solvent recovery process is required, the production cost is higher than that of the conventional radical polymerization method, and there is almost no industrial utility value. Therefore, polymers such as styrene and butadiene block polymers have had to rely on conventional solution polymerization methods.

In recent years, a living polymerization system has also been found in the radical polymerization method, and various living polymers have been obtained. For example, in the polymerization method disclosed in Japanese Patent Application Laid-Open No. 6-199916, 2,2,6,6-tetramethyl-1-piperidinitroxy free radical (TEMPO), which is a kind of nitroso radical compound, is mixed with a normal Benzoyl peroxide (BPO) which is a radical polymerization initiator
When a styrene is polymerized using the above method, a living polymer can be obtained at 150 ° C. in bulk.

[0006] However, in the invention, the polymerization system is controlled at 60 ° C to 80 ° C.
The method of stopping the polymerization reaction by cooling to ℃ has been adopted, and with this method alone, there is always an unstable nitroxy free radical at the end of the polymer, and the resulting polymer has poor thermal stability There was a problem.

[0007] WO 96/30421 discloses that a living polymer can be obtained by polymerizing styrene at 130 ° C. using a catalyst comprising a combination of phenethyl chloride, cuprous chloride and bipyridyl. However, the polymer obtained by this method has a problem that the terminal is halogen and the thermal stability is lower than that of polystyrene obtained by conventional radical polymerization.Moreover, if the catalyst residue is not sufficiently removed, coloring due to the catalyst residue may occur. And accelerated thermal decomposition of the polymer. As described above, there has been no production method for obtaining a polymer which is a living polymerization system under conventional bulk radical polymerization conditions and has excellent thermal stability.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a novel production method which enables living polymerization in a system under conventional bulk radical polymerization reaction conditions, and obtains a styrene-based material having good heat stability obtained by the production method. It is intended to provide a polymer.

[0009]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that polymerization of a styrene monomer can be carried out by using an organoaluminum compound or an organoaluminum compound and a specific alkyl metal compound. Or, using an initiator composed of an alkyl earth metal compound, it has been found, surprisingly, that living polymerization proceeds at a polymerization rate substantially similar to that of a conventional radical polymerization reaction, and based on this finding, the present invention was completed. .

Further, the obtained styrene-based polymer has no coloring at all without removing the catalyst residue and has an unstable bonding structure at the polymer terminal, as compared with a polymer obtained by conventional living radical polymerization. It was also found that the thermal stability was good without having.

That is, according to the present invention, in a method for producing a styrene polymer, a styrene monomer is polymerized at a polymerization temperature of 80.
The present invention relates to a method for producing a styrene-based polymer, characterized in that a polymerization reaction is carried out at a temperature of not lower than 250 ° C. and not higher than 250 ° C., and the kind of metal paired with the terminal of the polymerization growth is Al.

The present invention also provides (R ¹ ) _m as a polymerization initiator.
AlH _n (R ¹ represents a hydrocarbon compound residue, m + n =
The present invention relates to a method for producing a styrenic polymer, which comprises using an organometallic compound represented by 3, 0 ≦ n <3) and performing a polymerization reaction at a polymerization temperature of 80 ° C. to 250 ° C.

The present invention also provides (R ¹ ) _m as a polymerization initiator.
AlH _n (R ¹ represents a hydrocarbon compound residue, m + n =
3, 0 ≦ n <3) and R ² M ¹ and / or R ² OM
¹ (R ¹ and R ² are hydrocarbon compound residues, M ¹ is Li, N
a styrene-based polymer using an organometallic compound represented by at least one of alkali metals selected from a and K) and performing a polymerization reaction at a polymerization temperature of 80 ° C to 250 ° C. And a method for producing the same.

The present invention also provides (R ¹ ) _m as a polymerization initiator.
AlH _n (R ¹ represents a hydrocarbon compound residue, m + n =
3, 0 ≦ n <3) and (R ³ ) ₂ M ² and / or R ³ OM ²
R ³ and / or (R ³ O) ₂ M ² , wherein R ¹ and R ³ are hydrocarbon compound residues, and M ² is at least one kind of alkaline earth element selected from Mg, Ca, Sr and Ba The present invention relates to a method for producing a styrenic polymer, which comprises using an organometallic compound represented by the following formula (indicating a metal) and performing a polymerization reaction at a polymerization temperature of 80 ° C or more and 250 ° C or less.

The present invention also relates to the above-mentioned method for producing a styrenic polymer, wherein the concentration of the styrenic monomer in the polymerization solvent is substantially 100% by weight.

The present invention also provides (R ¹ ) _m AlH _n (R ¹ represents a hydrocarbon compound residue, m + n = 3, 0 ≦ n <3)
A styrene-based monomer polymerization initiator comprising:

The present invention also provides (R ¹ ) _m AlH _n (R ¹ represents a hydrocarbon compound residue, m + n = 3, 0 ≦ n <3)
And R ² M ¹ and / or R ² OM ¹ (R ¹ and R ² are hydrocarbon compound residues, and M ¹ is at least one alkali metal selected from Li, Na and K). The present invention relates to a styrene monomer polymerization initiator comprising an organometallic compound to be used.

The present invention also provides (R ¹ ) _m AlH _n (R ¹ represents a hydrocarbon compound residue, m + n = 3, 0 ≦ n <3)
And (R ³ ) ₂ M ² and / or R ³ OM ² R ³ and / or (R
³ O) ₂ M ² (R ¹ and R ³ are hydrocarbon compound residues, M ² is
(Indicating at least one kind of alkaline earth metal selected from Mg, Ca, Sr, and Ba).

The present invention also relates to a vinyl polymer obtained by the above-mentioned production method.

Hereinafter, the present invention will be described in detail. The styrene-based monomer used in the present invention is a styrene-containing monomer, and preferred styrene-based monomers include styrene, α-alkyl-substituted styrene, nucleated alkyl-substituted styrene, and nucleated alkoxy-substituted styrene. Is mentioned. For example, α-methylstyrene, α-methyl-p-methylstyrene, p-methylstyrene, m-methylstyrene, o-
Methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, p-isopropylstyrene, 2,4,6-trimethylstyrene, 1,
Examples thereof include 1-diphenylethylene and t-butylstyrene.

These styrenic monomers may be used alone or in combination of two or more kinds for the purpose of obtaining a copolymer. Preferably, a combination of the monomers described above is good.

The polymerization temperature is from 80 ° C to 250 ° C, preferably from 90 ° C to 240 ° C, more preferably 100 ° C to 240 ° C.
The temperature is preferably in the range of not lower than 230 ° C. The lower limit of the polymerization temperature is
It must have a certain rate at which the polymerization is completed at least within the targeted polymerization time. Although the polymerization proceeds even at a temperature lower than 80 ° C., the polymerization proceeds extremely slowly in the polymerization system of the present invention, so that it is judged to be undesirable from the viewpoint of industrial production. When the polymerization temperature is 250 ° C. or higher, side reactions such as a transfer reaction and a termination reaction frequently occur, making it difficult to increase the molecular weight and coloring the polymer.

In the present invention, the polymerization temperature need not be constant during the polymerization reaction, and may be increased at an arbitrary rate as the polymerization reaction proceeds. Particularly, in the initial stage of the polymerization reaction in which the concentration of the monomer is high, the reaction rate is high and the amount of generated heat is large, so the polymerization reaction is advanced from a low temperature, and the temperature is gradually increased as the concentration of the monomer decreases. Good. In the region where the conversion of the styrene monomer is 0 to 70%,
The polymerization is preferably carried out in a temperature range of 80 ° C to 200 ° C.
A method in which polymerization is performed in a temperature range of 250 ° C. or lower is preferable. However, if the viscosity of the polymerization reaction system is low and the polymerization temperature is not increased more than necessary, the polymerization in the region of the polymerization rate of 70% to 100% may be performed at 200 ° C. or lower.

The concentration of the styrene monomer in the polymerization solvent is not particularly limited, but is preferably 45% by weight or more.
0 wt% or less, more preferably 50 wt% or more and 100 w
t% or less. Considering the recovery of the solvent, the higher the concentration, the better. However, depending on the type of the obtained polymer, a certain amount of the solvent may be required depending on the relationship between the temperature and the viscosity of the polymerization system. However, if the concentration becomes excessively low, not only the polymerization reaction is slowed down, but also the transfer reaction to the solvent tends to occur at a high temperature, so that the monomer concentration is preferably higher in view of living polymerization.

The concentration of the styrene monomer in the polymerization solvent of 100 wt% in the present invention means that there is no solvent to be used other than the solvent derived from the initiator solution. Polymerization at a monomer concentration of 100% by weight without using a polymerization solvent has no transfer and termination reaction to the solvent, high use efficiency of the initiator, high productivity, and solvent recovery in the process after the polymerization is stopped. This is the most ideal polymerization condition industrially because no process is required.

The polymerization solvent referred to in the present invention means a solvent which does not participate in the polymerization reaction and is compatible with the polymer, and a solvent having a low radical chain transfer is particularly preferable. Preferred solvents are aromatic hydrocarbon compounds or alicyclic hydrocarbon compounds having relatively low polarity in the transfer reaction and termination reaction.

Examples thereof include ethylbenzene, toluene, isopropylbenzene, benzene, cyclohexane, t-butylbenzene, diphenyl ether, and xylene. In addition, a small amount of an aliphatic saturated hydrocarbon compound such as pentane, n-hexane, heptane, octane, nonane, and decane may be contained in these solvents within a range not exceeding the object of the present invention.

In the polymerization initiator used in the present invention, (R ¹ ) _m AlH _n (R ¹ represents a hydrocarbon compound residue;
m + n = 3, 0 ≦ n <3) means that at least one of the compounds bonded to Al is a residue of a hydrocarbon compound, for example, a methyl group, an ethyl group, Alkyl groups (including isomers) such as propyl, isopropyl, n-butyl, t-butyl, sec-butyl, amyl, hexyl and the like represented by CH ₃ (CH ₂ ) n-, methoxy Group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, t-butoxy group, sec-butoxy group, amyloxy group, hexyloxy group, etc., an alkoxy group represented by CH ₃ (CH ₂ ) n—O— (Including isomers) are preferred.

Specifically, trimethyl aluminum, triethyl aluminum, tripropyl aluminum, triisopropyl aluminum, tri-n-butyl aluminum, tri-iso-butyl aluminum, tri-n-
Octyl aluminum, dimethyl aluminum methoxide, diethyl aluminum ethoxide, ethyl aluminum diethoxide, diisobutyl aluminum isobutoxide, dimethyl aluminum hydride, diethyl aluminum hydride, dipropyl aluminum hydride, diisopropyl aluminum hydride, di-n-butyl aluminum hydride, di −i
So-butyl aluminum hydride, di-n-octyl aluminum hydride, methyl aluminum dihydride, ethyl aluminum dihydride, propyl aluminum dihydride, isopropyl aluminum dihydride, n-butyl aluminum dihydride, iso-butyl aluminum dihydride, n- Octyl aluminum dihydride and the like are preferred. These compounds may be used alone or in combination of two or more.

The R ² M ¹ and / or R ² used in the present invention
OM ¹ (R ¹ and R ² are hydrocarbon compound residues, M ¹ is L
The organic metal compound represented by at least one alkali metal selected from i, Na and K) is, specifically, R ² M ¹ wherein R ² is a residue of a hydrocarbon compound. ,
For example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, t-butyl group, sec-butyl group,
Alkyl groups such as amyl group and hexyl group (including isomers)
Are preferred.

Specific examples include methyllithium, n-
Butyl lithium, sec-butyl lithium, t-butyl lithium, iso-propyl lithium, n-propyl lithium, iso-propyl lithium, benzyl lithium, phenyl lithium, hexyl lithium, methoxy lithium, ethoxy lithium, butoxy lithium, phenoxy lithium, butyl There are sodium, butyl potassium, cumyl potassium and the like. These compounds may be used alone or in combination of two or more.

As R ² OM ¹ , R ² is a hydrocarbon-based compound residue, for example, methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, s
Preferred are an alkyl group (including an isomer) such as an ec-butyl group, an amyl group, and a hexyl group, a phenyl group, and an alkyl-substituted phenyl group.

Specific examples include methoxylithium,
Methoxy sodium, methoxy potassium, ethoxy lithium, ethoxy sodium, ethoxy potassium, propoxy lithium, propoxy sodium, propoxy potassium, isopropoxy lithium, isopropoxy sodium, isopropoxy potassium, n-butoxy lithium, n-butoxy sodium, n-butoxy potassium ,
sec-butoxylithium, sec-butoxysodium, sec-butoxypotassium, tert-butoxylithium, tert-butoxysodium, tert-butoxypotassium, amiloxylithium, amiloxysodium, amiloxypotassium, tert-amyloxylithium, tert- Amiloxy sodium, tert-
Potassium amiloxy, lithium hexyloxy, sodium hexyloxy, potassium hexyloxy,

Phenoxylithium, phenoxysodium, phenoxypotassium, 2,4-di-tert-butylphenoxylithium, 2,4-di-tert-butylphenoxysodium, 2,4-di-tert-butylphenoxypotassium, 6-di-tert-butylphenoxy lithium, 2,6-di-tert-butylphenoxy sodium,
2,6-di-tert-butylphenoxy potassium, 3,5
-Di-tert-butylphenoxylithium, 3,5-di-
Sodium tert-butylphenoxy, 3,5-di-tert
-Butylphenoxypotassium, 2,6-di-tert-butyl-4-methylphenoxylithium, 2,6-di-tert
-Butyl-4-methylphenoxy sodium, 2,6-
Di-tert-butyl-4-methylphenoxypotassium and the like. These compounds may be used alone or in combination of two or more. R ¹ M ¹ and R ¹ OM ¹ may be used alone or in combination.

(R ³ ) ₂ M ² and / or R ³ OM ² R ³ and / or (R ³ O) ₂ M ² used in the present invention (R ³ is a hydrocarbon compound residue, O is an oxygen atom , M ² are Mg, Ca,
And at least one kind of alkaline earth metal selected from Sr and Ba).
^In the case of ³ M ² , R ³ is a hydrocarbon-based compound residue such as methyl, ethyl, propyl, isopropyl, n-
Butyl group, t-butyl group, sec-butyl group, amyl group,
Alkyl groups (including isomers) such as hexyl groups are preferred.

Particularly preferred are organomagnesium compounds such as di-n-butylmagnesium, di-t-butylmagnesium, di-sec-butylmagnesium, and n-butylmagnesium.
Butyl, sec-butylmagnesium, n-butyl-ethylmagnesium, n-amylmagnesium and the like are preferred. These compounds may be used alone or in combination of two or more.

Next, R ³ OM ² R ³ is a compound in which one functional group bonded to M ² is an alkoxy group.
³ O) ₂ M ² is a compound in which two functional groups bonded to M ² are alkoxy groups. R ³ in the above is a residue of a hydrocarbon compound, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a t-
Preferred are an alkyl group (including isomers) such as a butyl group, a sec-butyl group, an amyl group, and a hexyl group, a phenyl group, and an alkyl-substituted phenyl group.

Specific examples include methylmethoxy magnesium, methyl methoxy calcium, methyl methoxy strontium, methyl methoxy barium, ethyl ethoxy magnesium, ethyl ethoxy calcium, ethyl ethoxy strontium, ethyl ethoxy barium, propyl propoxy magnesium, propyl propoxy calcium, propyl Propoxystrontium, propylpropoxybarium, butylbutoxymagnesium, butylbutoxycalcium, butylbutoxystrontium, butylbutoxybarium, dimethoxymagnesium, dimethoxycalcium, dimethoxystrontium, dimethoxybarium, diethoxymagnesium, diethoxycalcium, diethoxystrontium, diethoxybarium , Jiplo Alkoxy magnesium, dipropoxy calcium, dipropoxy strontium, dipropoxy barium,

Di-n-butoxymagnesium, di-n-
Butoxycalcium, di-n-butoxystrontium, di-n-butoxybarium, di-sec-butoxymagnesium, di-sec-butoxycalcium, di-sec-
Butoxystrontium, di-sec-butoxybarium, di-tert-butoxymagnesium, di-tert-butoxycalcium, di-tert-butoxystrontium,
Di-tert-butoxybarium, diamiloxymagnesium, diamiloxycalcium, diamiloxystrontium, diamiloxybarium, dihexyloxymagnesium, dihexyloxycalcium, dihexyloxystrontium, dihexyloxybarium, diphenoxymagnesium , Diphenoxy calcium, diphenoxystrontium, diphenoxy barium, and the like. These compounds may be used alone or in combination of two or more.

The method for terminating the polymerization of the present invention is not particularly limited, and a general terminating method for anionic polymerization can be used. For example, the polymerization is stopped by adding a proton acid compound such as water, alcohol, carboxylic acid, or the like, or carbon dioxide to the polymerization solution.

The terminated terminal structure of the polymer obtained by this method forms a saturated stable structure, so that the thermal stability of the polymer is superior to that of the polymer obtained by the conventional living radical polymerization method. It is thought that there is.

[0042]

Next, the present invention will be described specifically with reference to examples and comparative examples. Monomers used in the present invention, a solvent,
Was used after being purified by the following method. The following organometallic compounds and other reagents were used.

(1) Styrene (SM): manufactured by Asahi Kasei Corporation. Styrene was distilled once under reduced pressure under CaH ₂ , and after degassing, sealed under dry nitrogen. (2) p-methylstyrene (pMSt): Aldric
The solution was distilled once under reduced pressure under CaH ₂ manufactured by Company h, and after degassing, sealed under dry nitrogen. (3) Ethylbenzene (EB), cyclohexane: A special-grade reagent manufactured by Wako Pure Chemical Industries, Ltd. was distilled under reduced pressure once under CaH ₂ , deaerated, charged with molecular sieves, and sealed under dry nitrogen.

(4) n-butyllithium (nBuL)
i): manufactured by Kanto Chemical Co., Inc. of 1.6M n- hexane solution (5) Dibutyl magnesium (Bu ₂ Mg): Aldr
heptane ich Corporation 1.0 M, the n- dibutylmagnesium and sec- dibutylmagnesium 1: 1 mixed solution (6) triethylaluminum (Et ₃ Al): manufactured by Kanto Chemical Co., Inc. 0.9M of n- hexane solution

(7) Diethyl aluminum ethoxide (Et ₂ AlOEt): 0.9 M n-hexane solution manufactured by Kanto Chemical Co., Ltd. (8) Diisobutyl aluminum hydride ((iB
u) ₂ AlH): 1.5 M toluene solution manufactured by Aldrich (9) Polymerization terminator: A mixture of tetrahydrofuran (THF) and methanol (MeOH) at 90/10 (vol ratio) was used. The polymerization rate, molecular weight, and molecular weight distribution of the polymer obtained after the polymerization were measured by the following methods.

(10) Measurement of polymerization rate: Unreacted SM was measured by gas chromatography (GC) under condition 1.
The polymerization rate (Conv.) Was determined by the following equation. Conv. (%) = ([Prepared SM concentration] − [unreacted S
M concentration]) / [prepared SM concentration] × 100 (11) Number average molecular weight (Mn), weight average molecular weight (M
Measurements of w) and Mw / Mn were performed using gel permeation chromatography (GPC).

[GC measurement conditions] Measuring instrument: Shimadzu Corporation GC14B Column: PEG20M (φ3 mm * 3 m) Carrier gas: Nitrogen, flow rate 50 ml / min Detector: FID Column temperature: Hold at 125 ° C. for 10 minutes, then 35 ° C. / m
temperature to 230 ° C in the injection and detector temperature: 230 ° C Internal standard reagent: EB

[0048] [GPC measurement conditions] Measuring equipment: Tosoh HLC-8020 (differential refractive index detector built) Column: Tosoh TSKgel-GMH _XL two Operating temperature: 38 ° C. Solvent: tetrahydrofuran (THF) Sample concentration: 0.1 wt / v% Sampling pitch: 1 / 0.4 (times / second) Molecular weight calculation: A calibration curve is created using the relationship between the molecular weight of Tosoh TSK standard polystyrene and the elution time as a cubic regression curve,
Calculated.

In the following description of the examples and comparative examples, all polymerization procedures were carried out by the following procedures unless otherwise specified. [Polymerization operation method] A glass container and a syringe heated and dried at 140 ° C, a monomer, a solvent, and a reagent were placed in a nitrogen glove. Nitrogen glove is VDB-S made by Eikosho Co., Ltd.
AQ type was used. The inside of the nitrogen glove is in an environment sufficiently replaced with nitrogen dehydrated and dried with molecular sieves. A predetermined amount of a monomer and a solvent were put into a 50 ml pressure-resistant glass bottle with a syringe, and a predetermined amount of a polymerization initiator was further added.

When the concentration of the polymerization initiator was high, it was diluted with ethylbenzene in advance and added to the monomer solution. All polymerization solutions were 10 ml. After completion of the charging, the pressure-resistant bottle was stoppered with nitrile rubber, then taken out of the nitrogen glove and stoppered with a metal crown. The pressure bottle was placed in an oil bath at a predetermined temperature, and the time for putting the bottle was 0 hour. The reaction solution was stirred by appropriately shaking the pressure bottle. After a predetermined time, the pressure bottle was taken out of the oil bath, immediately put into water and cooled to room temperature. 5 ml of stop agent to prevent air from entering after cooling
The stopper was poured in and the pressure bottle was quickly shaken to uniformly disperse the terminator. The polymerization solution is diluted with THF, and the solution is subjected to GC and G
It was used as a measurement solution for PC.

[0051]

EXAMPLES Examples 1 to 5 A mixed solution of SM and EB was charged into a pressure-resistant bottle so as to have a concentration shown in Tables 1 and 2, and then an initiator solution was added so as to have a predetermined concentration, and the polymerization solution was sufficiently improved. Shake. Three identical polymerization solutions were prepared, and when the polymerization times shown in Tables 1 and 2 were reached, a terminator was added to stop the polymerization. Table 1 shows the analysis results of each polymer.

Generally, in the case of a living polymerization system, the Mn of the polymer is determined by Conv. It increases with the rise. Tables 1 and 2
As shown in Examples 1 to 5, the polymerization systems of Examples 1 to 5 had Mn of Conv.
It is a living polymerization system that increases with the rise of Also, 1
Despite polymerization at 50 ° C. for 4 hours, no molecular weight peak derived from radical thermal polymerization was observed. The obtained polymer solution was colorless and transparent.

[0053]

[Table 1]

[0054]

[Table 2]

Examples 6 to 10 Polymerization was carried out in the same manner as in Examples 1 to 5. The results are shown in Tables 3 and 4. In each case, the polymerization proceeded without runaway reaction, and Mn was found in Conv. Increased with the rise.
No molecular weight peak due to radical thermal polymerization was observed in this polymerization system. The obtained polymer solution was colorless and transparent. The polymers obtained in Examples 1 to 10 were treated with NM
As a result of structural analysis by R, no unsaturated bond structure was observed at any of the polymer chain terminals.

[0056]

[Table 3]

[0057]

[Table 4]

Comparative Example 1 Polymerization was carried out using an nBuLi solution instead of Et ₃ Al. The polymerization conditions were such that the SM concentration was 50 vol%. The amount added is 4.3 mM. The pressure bottle containing the initiator was placed in liquid nitrogen to prevent polymerization from starting. After being taken out of the nitrogen glove, it was placed in a 120 ° C. oil bath.
Within a few minutes, the polymerization solution was bumped and the polymerization was completed (runaway reaction). A polymerization terminator was added to completely dissolve the polymer.
The solution had a light brown color.

Comparative Example 2 A polymerization solution having the same composition as in Example 1 was placed in a water bath at 25 ° C. and taken out after 24 hours. Polymerization did not proceed at all.

[0060]

According to the present invention, compared with the conventional bulk radical polymerization method, polymerization can proceed in a living manner without causing a transfer reaction and termination reaction during polymerization, and the method does not cause coloring, and A styrenic polymer having a saturated polymer chain terminal could be provided.

Claims (9)

[Claims] 1. A method for producing a styrene-based polymer, wherein a styrene-based monomer is subjected to a polymerization reaction at a polymerization temperature of 80 ° C. to 250 ° C., and the kind of metal paired with the polymerization growth terminal is Al. A method for producing a styrene-based polymer, characterized in that: 2. A polymerization initiator comprising (R ¹ ) _m AlH _n (R ¹
Represents a hydrocarbon compound residue, m + n = 3, 0 ≦ n <
A method for producing a styrenic polymer, wherein the polymerization reaction is carried out at a polymerization temperature of 80 ° C or more and 250 ° C or less using the organometallic compound represented by 3). 3. A polymerization initiator comprising (R ¹ ) _m AlH _n (R ¹
Represents a hydrocarbon compound residue, m + n = 3, 0 ≦ n <
3) and R ² M ¹ and / or R ² OM ¹ (R ¹ and R ² are hydrocarbon-based compound residues, and M ¹ represents at least one alkali metal selected from Li, Na and K) And a polymerization temperature of 80 ° C. or higher and 250
A method for producing a styrenic polymer, wherein a polymerization reaction is carried out at a temperature of not more than ° C. 4. A polymerization initiator comprising (R ¹ ) _m AlH _n (R ¹
Represents a hydrocarbon compound residue, m + n = 3, 0 ≦ n <
3) and (R ³ ) ₂ M ² and / or R ³ OM ² R ³ and / or (R ³ O) ₂ M ² , wherein (R ¹ and R ³ are hydrocarbon compound residues,
M ² represents at least one kind of alkaline earth metal selected from Mg, Ca, Sr and Ba), and the polymerization reaction is carried out at a polymerization temperature of 80 ° C. or more and 250 ° C. or less. A method for producing a styrenic polymer. 5. The method for producing a styrenic polymer according to claim 1, wherein the concentration of the styrenic monomer in the polymerization solvent is substantially 100% by weight. 6. A styrene monomer polymerization initiator comprising (R ¹ ) _m AlH _n (R ¹ represents a hydrocarbon compound residue, m + n = 3, 0 ≦ n <3). 7. (R ¹ ) _m AlH _n (R ¹ represents a hydrocarbon compound residue) and R ² M ¹ and / or R ² OM ¹ (R ¹ ,
R ² is a hydrocarbon-based compound residue, and M ¹ is an initiator for styrene-based monomer polymerization comprising an organometallic compound represented by the formula: M ¹ is at least one kind of alkali metal selected from Li, Na and K). 8. (R ¹ ) _m AlH _n (R ¹ represents a hydrocarbon compound residue) and (R ³ ) ₂ M ² and / or R ³ OM ² R ³
And / or (R ³ O) ₂ M ² (R ¹ and R ³ are hydrocarbon-based compound residues, and M ² is at least one kind of alkaline earth metal selected from Mg, Ca, Sr and Ba) ) An initiator for polymerizing a styrenic monomer comprising an organometallic compound represented by the formula: 9. A styrene-based polymer obtained by the production method according to claim 1.