JPH06145214A - Purification of styrenic polymer - Google Patents

Abstract

PURPOSE:To effectively and highly purify a styrenic polymer (SPS) having a high degree of syndiotactic configuration. CONSTITUTION:SPS obtained by the use of a catalyst comprising (A) (1) an aluminoxane or (2) a specific coordination complex and (B) a transition metal compound is subjected to deashing treatment in a state dissolved in a solvent and, if necessary, further to a washing treatment. The productivity of the highly pure SPS can remarkably be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying a styrene-based polymer, and more specifically, a styrene-based polymer having a syndiotactic structure with a high degree of stereochemical structure of the polymer chain is efficiently and highly purified. On how to do.

[0002]

2. Description of the Related Art Styrenic polymers conventionally produced by radical polymerization or the like have a three-dimensional structure of atactic structure, and various molding methods such as injection molding, It is molded into various shapes by methods such as extrusion molding, blow molding, vacuum molding, and injection molding, and is widely used as household appliances, office equipment, household products, packaging containers, toys, furniture, synthetic paper and other industrial materials. It is used. However, such a styrene-based polymer having an atactic structure has a drawback that it is inferior in heat resistance and chemical resistance.

By the way, the present inventors' group has succeeded in developing a styrene-based polymer having a high syndiotacticity, and has further developed a contact product (alkyl compound) of a titanium compound and an organoaluminum compound with a condensing agent. It has been shown that a styrene-based polymer having a syndiotactic structure can be obtained by using a catalyst composed of aluminoxane) (JP-A-62-187708, etc.). The styrene-based polymer having such a syndiotactic structure is produced by slurry polymerization, bulk polymerization or the like, but it is advantageous to carry out the polymerization with a high concentration of styrene from the viewpoint of catalytic activity and productivity. Further, it is desired to reduce the catalyst component remaining in the obtained polymer product by deashing.

For this reason, the research group of the present inventors has previously conducted a method of deashing a styrene-based polymer having a syndiotactic structure with an alcoholic alkaline solution (Japanese Patent Laid-Open No. HEI 3).
-59011). Further, with respect to deashing, generally, a product having a low conversion rate or a polymer product obtained by polymerizing styrene at a low concentration is easily deashed,
Polymer products with high conversions, for example 60% or higher,
As the conversion rate increases, there is a problem that subsequent deashing cleaning becomes difficult. Against this problem, the research group of the present inventors has already proposed a method using an aromatic solvent and / or a styrene-based monomer as a swelling agent (JP-A-3-5901).
No. 2), a method of deashing at a temperature higher than the glass transition temperature (JP-A-4-252207), a method of using a swelling agent and a quenching agent (Japanese Patent Application No. 4-97573), and the like. ing. Although these methods have excellent effects as a method for purifying a styrene-based polymer having a syndiotactic structure, they have not been said to be sufficient. That is, the method using the swelling agent is the same as the prior art in that it is treated in the slurry state in which the polymer is dispersed in a solvent, deashing property depends on the morphology of the polymer, the particle size of the polymer is If it is large, there is a drawback that demineralization is deteriorated. Furthermore, since the slurry concentration is limited and cannot be made high, a large amount of solvent is required for transfer, or blockage during transfer, sample loss during solid / liquid separation, etc. easily occur, making safe operation difficult. For reasons such as
Due to the process, a huge amount of equipment is required for the post-treatment process, resulting in a large amount of equipment cost and utility cost. The method of deashing at a temperature above the glass transition temperature is excellent in deashing efficiency, but since the sample is processed in a swollen state, the sample may be dissolved depending on the composition or temperature of the deashing solution and may become unprocessable. .

Therefore, the inventors of the present invention have solved the above-mentioned problems of the prior art, and can more efficiently decalcify (removal of residual catalyst) a styrene-based polymer having a high conversion rate, and purify it to high purity. We have earnestly studied to develop a possible method.

[0006]

As a result, it has been found that the above problems can be solved by deashing the styrene polymer to be purified in a state of being dissolved in a solvent. The present invention has been completed based on such findings.
That is, the present invention provides a highly syndiotactic structure obtained by using (A) a coordination complex composed of an aluminoxane or cation and an anion in which a plurality of groups are bound to a metal, and (B) a catalyst composed of a transition metal compound. The present invention provides a method for purifying a styrene-based polymer, which comprises demineralizing a styrene-based polymer having the formula (1) in a state of being dissolved in a solvent. The present invention also provides a method for purifying a styrene-based polymer, characterized by further performing a washing treatment in a state of being dissolved in a solvent after the above deashing treatment.

The component (A) of the catalyst used in the present invention is
It is a coordination complex compound comprising an aluminoxane or cation and an anion in which a plurality of groups are bound to a metal. Here, the aluminoxane is obtained by contacting various organic aluminum compounds with a condensing agent. As the organoaluminum compound to react the raw material, usually formula AlR ¹ ₃ ···· (I) wherein, R ¹ represents an alkyl group having 1 to 8 carbon atoms. ] Organoaluminum compounds represented by the following, specifically, trimethylaluminum, triethylaluminum, triisobutylaluminum and the like can be mentioned, and among them, trimethylaluminum is most preferable. On the other hand, the condensing agent to be condensed with the organoaluminum compound is typically water, but any condensing agent capable of causing a condensation reaction of alkylaluminum may be used. Such an aluminoxane has the general formula (II)

[0008]

[Chemical 1]

[In the formula, n represents the degree of polymerization, is a number of 2 to 50, and R ¹ represents an alkyl group having 1 to 8 carbon atoms. ] A chain alkylaluminoxane represented by the general formula (III)

[0010]

[Chemical 2]

There is a cyclic alkylaluminoxane having a repeating unit represented by Among such alkylaluminoxanes, those in which R ¹ is a methyl group, that is, methylaluminoxane are particularly preferable. In general, a contact product of an alkylaluminum compound such as trialkylaluminum and water is, together with the above-mentioned chain alkylaluminoxane and cyclic alkylaluminoxane, unreacted trialkylaluminum, a mixture of various condensation products, and further these. Molecules are intricately associated with each other, and they are various products depending on the contact conditions of the alkylaluminum compound and water. The reaction between the alkylaluminum and water at this time is not particularly limited, and the reaction may be performed according to a known method. For example, (1) a method in which alkylaluminum is dissolved in an organic solvent and brought into contact with water, (2) a method in which alkylaluminum is initially added at the time of polymerization and then water is added, and (3) metal There is a method of reacting water of crystallization contained in salt or the like, or water adsorbed to an inorganic substance or an organic substance with alkylaluminum. The water may contain up to about 20% of ammonia, amine such as ethylamine, sulfur compound such as hydrogen sulfide, phosphorus compound such as phosphite.

As the aluminoxane used in the present invention, particularly the alkylaluminoxane, when a water-containing compound or the like is used after the above-mentioned catalytic reaction, the solid residue is filtered off, and the filtrate is subjected to 30 to 200 under normal pressure or reduced pressure. What was heat-treated while distilling off the solvent at a temperature of 40 ° C., preferably 40 ° C. to 150 ° C. for 20 minutes to 8 hours, preferably 30 minutes to 5 hours is preferable. In this heat treatment, the temperature may be appropriately determined depending on various situations, but it is usually within the above range. Generally, if the temperature is lower than 30 ° C., no effect is exhibited, and if the temperature exceeds 200 ° C., thermal decomposition of the aluminoxane itself occurs, which is not preferable. The reaction product may be obtained in the form of a colorless solid or solution depending on the treatment conditions of the heat treatment. The product thus obtained can be used as a catalyst solution after being dissolved or diluted with a hydrocarbon solvent, if necessary.

A preferred example of such an alkylaluminoxane is that the high magnetic field component in the methyl proton signal region based on the aluminum-methyl group (Al-CH ₃ ) bond observed by the proton nuclear magnetic resonance absorption method is 50% or less. It is a thing. That is, when the proton nuclear magnetic resonance ( ¹ H-NMR) spectrum of the above contact product was observed in a toluene solvent at room temperature, the methyl proton signal based on Al—CH ₃ was found to be tetramethylsilane (TMS) standard. In the range of 1.0 to -0.5 ppm. Because TMS proton signals (0 ppm) is in the methyl protons observation area based on the Al-CH _3, methyl proton signal based on the Al-CH _3, measured with respect to the methyl proton signal 2.35ppm toluene in TMS standard However, high magnetic field components (that is, -0.1 to -0.5 pp
m) and other magnetic field components (that is, 1.0 to -0.1 ppm), the high magnetic field component is 50% or less, preferably 45 to 5%, of the alkyl of the present invention. It can be suitably used as an aluminoxane.

In the method of the present invention, as the component (A) of the catalyst, a coordination complex compound comprising a cation and an anion in which a plurality of groups are bound to a metal can be used instead of the aluminoxane. There are various kinds of such coordination complex compounds, and for example, compounds represented by the following general formula (IV) or (V) can be preferably used. ([L ¹ -H] ^g +) _h ^{([M 1 X 1 X 2 ··· X} n ] _{^{(nm) -) i ··· (}} IV) or ([L ^{2] g} +) _h ([M ² X ¹ X ² ... X ⁿ ] ^(nm)- ) _i ... (V) (where L ² is M ³ , T ¹ T ² M ⁴ or T ³ ₃ C described later)
Is. ) [In the formulas (IV) and (V), L ¹ is a Lewis base,
M ¹ and M ² are metals selected from groups 5 to 15 of the periodic table, M ³ is a metal selected from groups 8 to 12 of the periodic table, and M ⁴ is group 8 to 10 of the periodic table. A metal selected from, X ^{1 to} X ⁿ are each a hydrogen atom, a dialkylamino group, an alkoxy group, an aryloxy group, and a carbon number of 1 to 20.
Represents an alkyl group, an aryl group having 6 to 20 carbon atoms, an alkylaryl group, an arylalkyl group, a substituted alkyl group, an organic metalloid group or a halogen atom, and is represented by T ¹ and T ²
Represents a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group or a fluorenyl group, and T ³ represents an alkyl group. m is an valence of M ¹ and M ² and is an integer of 1 to 7, n is an integer of 2 to 8, g is an ionic valence of L ¹ -H and L ² and is an integer of 1 to 7, and h is 1 or more. Integer, i = h × g /
(Nm). ] Specific examples of M ¹ and M ² include B, Al, Si, P and A.
Specific examples of M ³ , such as s and Sb, include Ag and Cu, and M ^4.
Specific examples of Fe, Co, Ni, and the like are given. X
Specific examples of ^{1 to} X ⁿ include, for example, dimethylamino group, diethylamino group as dialkylamino group, methoxy group, ethoxy group, n-butoxy group as alkoxy group, phenoxy group as aryloxy group, and 2,6-dimethylphenoxy group. Group, naphthyloxy group, carbon number 1-2
As an alkyl group of 0, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an n-octyl group, a 2-ethylhexyl group, an aryl group having 6 to 20 carbon atoms, an alkylaryl group or an aryl group. As an alkyl group, a phenyl group, a p-tolyl group, a benzyl group, a pentafluorophenyl group, a 3,5-di (trifluoromethyl) phenyl group, a 4-tert-butylphenyl group,
2,6-Dimethylphenyl group, 3,5-dimethylphenyl group, 2,4-dimethylphenyl group, 1,2-dimethylphenyl group, F, Cl, Br, I as halogen, pentamethylantimony group as organic metalloid group , Trimethylsilyl group, trimethylgermyl group, diphenylarsine group, dicyclohexylantimony group, diphenylboron group. Specific examples of the substituted cyclopentadienyl group for R ⁵ and R ⁶ include a methylcyclopentadienyl group, a butylcyclopentadienyl group, and a pentamethylcyclopentadienyl group.

Of the compounds of the general formulas (IV) and (V), the following compounds can be used particularly preferably. For example, as the compound of the general formula (IV), triethylammonium tetraphenylborate and tri (n-tetraphenylborate) can be used.
Butyl) ammonium, trimethylammonium tetraphenylborate, triethylammonium tetra (pentafluorophenyl) borate, tri (n-butyl) ammonium tetra (pentafluorophenyl) borate, triethylammonium hexafluoroarsenate, and the like.
Further, for example, as the compound of the general formula (V), pyridinium tetra (pentafluorophenyl) borate, pyrrolinium tetra (pentafluorophenyl) borate, N, N-dimethylanilinium tetra (pentafluorophenyl) borate, tetra (pentafluoro) Phenyl) borate methyldiphenylammonium, tetraphenylferrocenium borate, dimethylferrocenium tetra (pentafluorophenyl) borate, ferrocenium tetra (pentafluorophenyl) borate, decamethylferrocenium tetra (pentafluorophenyl) borate, tetra (pentafluoro) Phenyl) acetylferrocenium borate, formylferrocenium tetra (pentafluorophenyl) borate, cyanoferrocenium tetra (pentafluorophenyl) borate, tetra Eniru borate silver tetra (pentafluorophenyl) borate silver tetraphenylborate trityl tetra (pentafluorophenyl) borate trityl,
Examples thereof include silver hexafluoroarsenate, silver hexafluoroantimonate, silver tetrafluoroborate and the like.

On the other hand, examples of the transition metal compound, which is the component (B) of the catalyst used in the present invention, include compounds of metals of Groups 3 to 6 of the periodic table and compounds of lanthanum-based metals, of which the Group 4 metals are included. Compounds of (titanium, zirconium, hafnium, vanadium, etc.) are preferred. There are various titanium compounds, for example, the general formula (VI) Ti R ² _a R ³ _b R ⁴ _c R ⁵ _{4- (a + b + c)} (VI) or the general formula (VII ) Ti R ² _d R ³ _e R ⁴ _{3- (d + e)} ... (VII) [wherein R ² , R ³ , R ⁴ and R ⁵ are each a hydrogen atom or an alkyl group having 1 to 20 carbon atoms]. Group, C1-C20 alkoxy group, C6-C20 aryl group, alkylaryl group, arylalkyl group, C1-C20 acyloxy group, cyclopentadienyl group, substituted cyclopentadienyl group, Indicates an indenyl group or halogen atom. a, b, and c each represent an integer of 0 to 4, and d and e
Each represents an integer of 0 to 3. ] At least one compound selected from the group consisting of titanium compounds and titanium chelate compounds.

R ² , R in the general formula (VI) or (VII)
³ , R ⁴ and R ⁵ are each a hydrogen atom and have 1 to 20 carbon atoms.
Alkyl groups (specifically, methyl group, ethyl group, propyl group, butyl group, amyl group, isoamyl group, isobutyl group, octyl group, 2-ethylhexyl group, etc.), alkoxy groups having 1 to 20 carbon atoms (specifically Are methoxy group, ethoxy group, propoxy group, butoxy group, amyloxy group,
Hexyloxy group, 2-ethylhexyloxy group, etc.), aryl group having 6 to 20 carbon atoms, alkylaryl group, arylalkyl group (specifically, phenyl group, tolyl group, xylyl group, benzyl group, etc.), carbon number 1 ~ 20
Acyloxy group (specifically, heptadecylcarbonyloxy group, etc.), cyclopentadienyl group, substituted cyclopentadienyl group (specifically, methylcyclopentadienyl group, 1,2-dimethylcyclopentadienyl group) , Pentamethylcyclopentadienyl group), an indenyl group or a halogen atom (specifically chlorine, bromine, iodine, fluorine). These R ² , R ³ , R ⁴ and R ⁵ may be the same or different. Further, a, b and c each represent an integer of 0 to 4, and d,
e shows the integer of 0-3, respectively.

More preferred titanium compounds are those represented by the general formula (VIII) Ti RXYZ .. (VIII) [wherein R represents a cyclopentadienyl group, a substituted cyclopentadienyl group or an indenyl group, and X, Y and Z is each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, and 6 to 20 carbon atoms. Represents an arylalkyl group or a halogen atom. ] There is a titanium compound represented by. R in this formula
The substituted cyclopentadienyl group represented by is, for example, a cyclopentadienyl group substituted with one or more alkyl groups having 1 to 6 carbon atoms, specifically, methylcyclopentadienyl group, 1,2-dimethylcyclo Examples thereof include a pentadienyl group and a pentamethylcyclopentadienyl group. Also, X, Y
And Z are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms (specifically, methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, amyl group, isoamyl group, octyl group, 2- An ethylhexyl group), an alkoxy group having 1 to 12 carbon atoms (specifically, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an amyloxy group,
Hexyloxy group, octyloxy group, 2-ethylhexyloxy group, etc.), aryl group having 6 to 20 carbon atoms (specifically, phenyl group, naphthyl group, etc.), aryloxy group having 6 to 20 carbon atoms (specifically, Represents a phenoxy group, etc.), an arylalkyl group having 6 to 20 carbon atoms (specifically a benzyl group) or a halogen atom (specifically chlorine, bromine, iodine or fluorine).

Specific examples of the titanium compound represented by the general formula (VIII) include cyclopentadienyltrimethyl titanium, cyclopentadienyl triethyl titanium, cyclopentadienyl tripropyl titanium, and cyclopentadienyl tributyl titanium. , Methylcyclopentadienyl trimethyl titanium, 1,2-dimethyl cyclopentadienyl trimethyl titanium, pentamethyl cyclopentadienyl trimethyl titanium, pentamethyl cyclopentadienyl triethyl titanium, pentamethyl cyclopentadienyl tripropyl titanium, penta Methyl cyclopentadienyl tributyl titanium, cyclopentadienyl methyl titanium dichloride, cyclopentadienyl ethyl titanium dichloride, pentamethyl cyclopentadienyl methyl titanium dichloride Lolide, pentamethylcyclopentadienylethyl titanium dichloride, cyclopentadienyl dimethyl titanium monochloride, cyclopentadienyl diethyl titanium monochloride, cyclopentadienyl titanium trimethoxide, cyclopentadienyl titanium triethoxide, cyclopenta Dienyl titanium tripropoxide, cyclopentadienyl titanium triphenoxide,
Pentamethylcyclopentadienyl titanium trimethoxide, pentamethylcyclopentadienyl titanium triethoxide, pentamethylcyclopentadienyl titanium tripropoxide, pentamethylcyclopentadienyl titanium tributoxide, pentamethylcyclopentadienyl titanium Triphenoxide, cyclopentadienyl titanium trichloride, pentamethylcyclopentadienyl titanium trichloride, cyclopentadienyl methoxy titanium dichloride, cyclopentadienyl dimethoxy titanium chloride, pentamethyl cyclopentadienyl methoxy titanium dichloride, cyclopentadi Enyltribenzyl titanium, pentamethylcyclopentadienylmethyldiethoxy titanium, indenyl titanium trichloride, indenyl titanium trimetho Sid, indenyl titanium triethoxide, indenyl trimethyl titanium, indenyl tribenzyl titanium and the like. Of these titanium compounds, compounds containing no halogen atom are preferable, and titanium compounds having one π-electron ligand as described above are particularly preferable. Further, as the titanium compound, the general formula (IX)

[0020]

[Chemical 3]

[In the formula, R ⁶ and R ⁷ represent a halogen atom, an alkoxy group having 1 to 20 carbon atoms and an acyloxy group, respectively, and k represents 2 to 20. ] A condensed titanium compound represented by the following may be used. Further, the titanium compound may be used in the form of a complex with an ester or ether.

Typical examples of the trivalent titanium compound represented by the general formula (VII) include titanium trihalides such as titanium trichloride and cyclopentadienyl titanium compounds such as cyclopentadienyl titanium dichloride. In addition to these, those obtained by reducing a tetravalent titanium compound may be mentioned. These trivalent titanium compounds may be used in the form of a complex with an ester or ether.

The zirconium compound as the transition metal compound is tetrabenzyl zirconium, zirconium tetraethoxide, zirconium tetrabutoxide,
There are bisindenyl zirconium dichloride, triisopropoxy zirconium chloride, zirconium benzyl dichloride, tributoxy zirconium chloride, etc., and hafnium compounds include tetrabenzyl hafnium,
There are hafnium tetraethoxide, hafnium tetrabutoxide, and the like. Further, vanadium compounds include vanadyl bisacetylacetonate, vanadyltriacetylacetonate, triethoxyvanadyl, and tripropoxyvanadyl. Among these transition metal compounds, titanium compounds are particularly suitable.

Regarding the transition metal compound which is the other component (B), a transition metal compound having two ligands having a conjugated π electron, for example, the general formula (X) M ⁵ R ⁸ R ⁹ R ¹⁰ R ¹¹ .. (X) [wherein, M ⁵ represents titanium, zirconium, or hafnium, R ⁸ and R ⁹ represent a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, or a fluorenyl group, and R ¹⁰ And R ¹¹ are hydrogen, halogen, a hydrocarbon group having 1 to 20 carbon atoms, and 1 carbon atom, respectively.
~ 20 alkoxy groups, amino groups or 1 to 2 carbon atoms
The thioalkoxy group of 0 is shown. However, R ⁸ and R ⁹ are hydrocarbon groups having 1 to 5 carbon atoms, alkylsilyl groups having 1 to 20 carbon atoms and 1 to 5 silicon atoms, or germanium-containing hydrocarbons having 1 to 20 carbon atoms and 1 to 5 germanium atoms. It may be crosslinked by a group. ] There is at least one compound selected from the group consisting of transition metal compounds.

R ⁸ and R ⁹ in the general formula (X) are cyclopentadienyl group and substituted cyclopentadienyl group (specifically, methylcyclopentadienyl group; 1,3-dimethylcyclopentadienyl group). 1,2,4-trimethylcyclopentadienyl group; 1,2,3,4-tetramethylcyclopentadienyl group; pentamethylcyclopentadienyl group; trimethylsilylcyclopentadienyl group;
1,3-di (trimethylsilyl) cyclopentadienyl group; 1,2,4-tri (trimethylsilyl) cyclopentadienyl group; tert-butyl cyclopentadienyl group; 1,3-di (tert-butyl) cyclo Pentadienyl group; 1,2,4-tri (tertiarybutyl)
Cyclopentadienyl group, etc.), indenyl group, substituted indenyl group (specifically, methylindenyl group; dimethylindenyl group; trimethylindenyl group, etc.), fluorenyl group or substituted fluorenyl group (eg, methylfluorenyl group) R ⁸ and R ⁹ may be the same or different, and R ⁸ and R ⁹ may be an alkylidene group having 1 to 5 carbon atoms (specifically, methine group, ethylidene group, propylidene group, dimethylcarbyl group). Etc.) or an alkylsilyl group having 1 to 20 carbon atoms and 1 to 5 silicon atoms (specifically, a dimethylsilyl group, a diethylsilyl group, a dibenzylsilyl group, etc.). on the other hand,
R ¹⁰ and R ¹¹ are as described above, but more specifically, each independently, hydrogen, an alkyl group having 1 to 20 carbon atoms (methyl group, ethyl group, propyl group, n-butyl group, isobutyl group, Amyl group, isoamyl group, octyl group, 2-ethylhexyl group, etc.), aryl group having 6 to 20 carbon atoms (specifically, phenyl group, naphthyl group, etc.), 7 to 2 carbon atoms
0 arylalkyl group (specifically, benzyl group, etc.), alkoxy group having 1 to 20 carbon atoms (specifically, methoxy group, ethoxy group, propoxy group, butoxy group, amyloxy group, hexyloxy group, octyl group) Oxy group,
2-ethylhexyloxy group and the like), an aryloxy group having 6 to 20 carbon atoms (specifically, a phenoxy group and the like), and further an amino group and a thioalkoxy group having 1 to 20 carbon atoms.

Specific examples of the transition metal compound represented by the general formula (X) include biscyclopentadienyl titanium dimethyl; biscyclopentadienyl titanium diethyl; biscyclopentadienyl titanium dipropyl;
Bis (cyclopentadienyl) titanium dibutyl; Bis (methylcyclopentadienyl) titanium dimethyl; Bis (tert-butyl cyclopentadienyl) titanium dimethyl; Bis (1,3-dimethylcyclopentadienyl) titanium dimethyl; Bis (1 , 3-Ditertiarybutylcyclopentadienyl) titanium dimethyl; bis (1,2,2
4-trimethylcyclopentadienyl) titanium dimethyl; bis (1,2,3,4-tetramethylcyclopentadienyl) titanium dimethyl; biscyclopentadienyl titanium dimethyl; bis (trimethylsilylcyclopentadienyl) titanium dimethyl; Bis (1,3-di (trimethylsilyl) cyclopentadienyl) titanium dimethyl;
Bis (1,2,4-tri ((trimethylsilyl) cyclopentadienyl) titanium dimethyl; bisindenyl titanium dimethyl; bisfluorenyl titanium dimethyl; methylene biscyclopentadienyl titanium dimethyl; ethylidene biscyclopentadienyl titanium Dimethyl; methylenebis (2,3,4,5-tetramethylcyclopentadienyl) titanium dimethyl; ethylidenebis (2,3,4
5-tetramethylcyclopentadienyl) titanium dimethyl; dimethylsilylbis (2,3,4,5-tetramethylcyclopentadienyl) titanium dimethyl; methylenebisindenyltitanium dimethyl; ethylidenebisindenyltitaniumdimethyl; dimethylsilyl Bisindenyl titanium dimethyl; methylene bis fluorenyl titanium dimethyl; ethylidene bis fluorenyl titanium dimethyl; dimethyl silyl bis fluorenyl titanium dimethyl; methylene (tertiary butyl cyclopentadienyl) (cyclopentadienyl) titanium dimethyl; Methylene (cyclopentadienyl) (indenyl) titanium dimethyl; ethylidene (cyclopentadienyl) (indenyl) titanium dimethyl; dimethylsilyl (cyclopentadienyl) (indenyl) titanium di Chill; methylene (cyclopentadienyl) (fluorenyl) titanium dimethyl; ethylidene (cyclopentadienyl) (fluorenyl) titanium dimethyl; dimethylsilyl (cyclopentadienyl) (fluorenyl) titanium dimethyl; methylene (indenyl)
(Fluorenyl) titanium dimethyl; ethylidene (indenyl) (fluorenyl) titanium dimethyl; dimethylsilyl (indenyl) (fluorenyl) titanium dimethyl; biscyclopentadienyl titanium dibenzyl; bis (tert-butyl cyclopentadienyl) titanium dibenzyl; Bis (methylcyclopentadienyl) titanium dibenzyl; bis (1,3-dimethylcyclopentadienyl)
Titanium dibenzyl; bis (1,2,4-trimethylcyclopentadienyl) titanium dibenzyl; bis (1,2,
3,4-tetramethylcyclopentadienyl) titanium dibenzyl; bispentamethylcyclopentadienyl titanium dibenzyl; bis (trimethylsilylcyclopentadienyl) titanium dibenzyl; bis (1,3-di- (trimethylsilyl) cyclo Pentadienyl) titanium dibenzyl; bis (1,2,4-tri (trimethylsilyl) cyclopentadienyl) titanium dibenzyl; bisindenyl titanium dibenzyl; bisfluorenyl titanium dibenzyl; methylenebiscyclopentadienyl Titanium dibenzyl; ethylidene biscyclopentadienyl titanium dibenzyl; methylene bis (2,3,4,5-tetramethylcyclopentadienyl) titanium dibenzyl; ethylidene bis (2,3,4,5-tetramethylcyclopenta) Dienyl) titanium dibenzi ; Dimethylsilyl bis (2,3,
4,5-Tetramethylcyclopentadienyl) titanium dibenzyl; methylenebisindenyl titanium dibenzyl;
Ethylidene bisindenyl titanium dibenzyl; dimethylsilyl bis indenyl titanium dibenzyl; methylene bis fluorenyl titanium dibenzyl; ethylidene bis fluorenyl titanium dibenzyl; dimethyl silyl bis fluorenyl titanium dibenzyl; methylene (cyclopentadi Ethenyl) (indenyl) titanium dibenzyl; ethylidene (cyclopentadienyl) (indenyl) titanium dibenzyl; dimethylsilyl (cyclopentadienyl) (indenyl) titanium dibenzyl; methylene (cyclopentadienyl) (fluorenyl) titanium dibenzyl Benzyl; ethylidene (cyclopentadienyl) (fluorenyl) titanium dibenzyl; dimethylsilyl (cyclopentadienyl) (fluorenyl) titanium dibenzyl; methylene (indenyl) (fluorenyl) Tanji benzyl; ethylidene (indenyl) (fluorenyl) titanium dibenzyl; dimethylsilyl (indenyl) (fluorenyl) titanium dibenzyl, bis cyclopentadienyl titanium di methoxide; biscyclopentadienyl titanium diethoxide;
Biscyclopentadienyl titanium dipropoxide; Biscyclopentadienyl titanium dibutoxide; Biscyclopentadienyl titanium diphenoxide; Bis (methylcyclopentadienyl) titanium dimethoxide; Bis (1,3-dimethyl Cyclopentadienyl) titanium dimethoxide; bis (1,2,4-trimethylcyclopentadienyl) titanium dimethoxide; bis (1,2,
3,4-Taylamethylcyclopentadienyl) titanium dimethoxide; bispentamethylcyclopentadienyl titanium dimethoxide; bis (trimethylsilylcyclopentadienyl) titanium dimethoxide; bis (1,3
-Di (trimethylsilyl) cyclopentadienyl) titanium dimethoxide; bis (1,2,4-tri (trimethylsilyl) cyclopentadienyl) titanium dimethoxide; bisindenyl titanium dimethoxide; bisfluorenyl titanium Dimethoxide; methylenebiscyclopentadienyl titanium dimethoxide; ethylidene biscyclopentadienyl titanium dimethoxide; methylenebis (2,3,4,5-tetramethylcyclopentadienyl) titanium dimethoxide; ethylidene bis (2, 3,
4,5-Tetramethylcyclopentadienyl) titanium dimethoxide; dimethylsilylbis (2,3,4,5-
Tetramethylcyclopentadienyl) titanium dimethoxide; methylenebisindenyl titanium dimethoxide;
Methylenebis (methylindenyl) titanium dimethoxide; ethylidene bisindenyl titanium dimethoxide;
Dimethylsilylbisindenyl titanium dimethoxide;
Methylene bis fluorenyl titanium dimethoxide; methylene bis (methyl fluorenyl) titanium dimethoxide; ethylidene bis fluorenyl titanium dimethoxide; dimethylsilyl bis fluorenyl titanium dimethoxide; methylene (cyclopentadienyl) (Indenyl) titanium dimethoxide; ethylidene (cyclopentadienyl) (indenyl) titanium dimethoxide; dimethylsilyl (cyclopentadienyl) (indenyl) titanium dimethoxide; methylene (cyclopentadienyl) (fluorenyl) titanium Dimethoxide; ethylidene (cyclopentadienyl) (fluorenyl) titanium dimethoxide; dimethylsilyl (cyclopentadienyl) (fluorenyl) titanium dimethoxide; methylene (indenyl) (fluorenyl ) Titanium di methoxide; ethylidene (indenyl) (fluorenyl) titanium di methoxide; dimethylsilyl (indenyl) (fluorenyl) titanium di methoxide and the like.

The zirconium compounds include ethylidene biscyclopentadienyl zirconium dimethoxide and dimethylsilylbiscyclopentadienyl zirconium dimethoxide, and the hafnium compounds include ethylidene biscyclopentadienyl hafnium dimethoxide. Examples include methoxide and dimethylsilylbiscyclopentadienyl hafnium dimethoxide. Among these, titanium compounds are particularly preferable. Furthermore, in addition to these combinations, 2,2'-thiobis (4-methyl-
6-t-butylphenyl) titanium diisopropoxide;
It may be a bidentate complex such as 2,2′-thiobis (4-methyl-6-t-butylphenyl) titanium dimethoxide.

In the method of the present invention, in addition to the above-mentioned components (A) and (B), other catalyst components such as organoaluminum may be added, if desired. This organoaluminum has the general formula (X
_{^{I) R 12 j Al (OR}} 13) x H y X 'z ··· (XI) wherein, R ¹² and R ¹³ 1 to 8 carbon atoms are each independently,
Preferably, it represents an alkyl group having 1 to 4 carbon atoms, X ′ represents halogen, j is 0 <j ≦ 3, x is 0 ≦ x <3, y is 0 ≦ y <3, and z is 0 ≦ z <. 3 and j + x +
y + z = 3], and the activity is further improved by adding this. Examples of the organoaluminum compound represented by the general formula (XI) include the following. y
= Z = 0 corresponds to the general formula R ¹² _j Al (OR ¹³ ) _3-j [wherein R ¹² and R ¹³ are the same as defined above, and j is preferably 1.5 ≦ j ≦ 3]. x = y =
The case corresponding to 0 is represented by the general formula R ¹² _j AlX ′ _3-j [wherein R ¹² and X ^′ are as defined above, and j is preferably 0 <j <3]. . Those corresponding to the case of x = z = 0 are represented by the general formula R ¹² _j AlH _3-j [wherein R ¹² is the same as above, and j is preferably 2 ≦
j <3]. The case corresponding to y = 0 is represented by the general formula R ¹² _j Al (OR ¹³ ) _x X ′ _z [wherein R ¹² , R ¹³ and X ′ are the same as described above, and 0 <
j ≦ 3, 0 ≦ x <3, 0 ≦ z <3, and j + x + z = 3]. In the organoaluminum compound represented by the general formula (XI), y = z = 0 and j =
The compound of 3 is selected from, for example, trialkylaluminum such as trimethylaluminum, triethylaluminum and tributylaluminum, or a combination thereof. In the case of y = z = 0 and 1.5 ≦ j <3, other than dialkyl aluminum alkoxide such as diethyl aluminum ethoxide and dibutyl aluminum butoxide, alkyl aluminum sesqui alkoxide such as ethyl aluminum sesquiethoxide and butyl aluminum sesquibutoxide. Examples thereof include partially alkoxylated alkylaluminum having an average composition represented by R ¹² _2.5 Al (OR ¹³ ) _0.5 . Examples of compounds corresponding to the case of x = y = 0 are dialkylaluminum halides (j = 2) such as diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide, etc., ethylaluminum sesquichloride,
Alkyl aluminum sesquihalogenides such as butyl aluminum sesquichloride, ethyl aluminum sesquibromide (j = 1.5), alkyl aluminum dihalogenides such as ethyl aluminum dichloride, propyl aluminum dichloride, butyl aluminum dibromide (j = 1) ) And the like, which are partially halogenated alkyl aluminums. Examples of compounds corresponding to the case of x = z = 0 are dialkyl aluminum hydrides (j = 2) such as diethyl aluminum hydride and dibutyl aluminum hydride, alkyl aluminum dihydrides (x such as ethyl aluminum dihydride and propyl aluminum dihydride (x = J) and other partially hydrogenated alkylaluminums. Examples of compounds corresponding to the case where y = 0 are partially aluminumized and halogenated alkyl aluminums such as ethyl aluminum ethoxy chloride, butyl aluminum butoxy cyclolide, ethyl aluminum ethoxy bromide (j = x = z = 1). Is. Among these, particularly preferred are triisobutylaluminum and triisobutylaluminum hydride.

The catalyst used in the present invention contains the above-mentioned components (A) and (B) as main components, and in addition to the above components, other catalyst components can be added if desired. The blending ratios of the component (A) and the component (B) in this catalyst are different depending on various conditions and are not uniquely determined, but usually, the metal in the component (B) and the metal in the component (A) are usually used. When the ratio (molar ratio) to aluminoxane is 1: 1 to 1:10 ⁶ ,
It is preferably 1:10 to 1:10 ⁴ , and in the case of a coordination complex composed of a cation and an anion in which a plurality of groups are bound to a metal, 0.1: 1 to 1: 0.1, and further a compound represented by the general formula (XI ) When adding organoaluminum represented by
It is 1:10 ³ .

To produce a styrene-based polymer, a styrene-based monomer is polymerized (or copolymerized) in the presence of a catalyst containing the above-mentioned components (A) and (B) as a main component. Here, the styrene-based monomer refers to styrene and / or a styrene derivative. Specific examples of the styrene derivative include:
p-methylstyrene; m-methylstyrene; o-methylstyrene; 2,4-dimethylstyrene; 2,5-dimethylstyrene; 3,4-dimethylstyrene; 3,5-dimethylstyrene; p-ethylstyrene; m- Ethyl styrene; alkyl styrenes such as p-tert-butyl styrene; p-chlorostyrene; m-chlorostyrene; o-
Chlorostyrene; p-bromostyrene; m-bromostyrene; o-bromostyrene; p-fluorostyrene; m
-Fluorostyrene; o-fluorostyrene; halogenated styrene such as o-methyl-p-fluorostyrene,
p-methoxystyrene; m-methoxystyrene; o-methoxystyrene; p-ethoxystyrene; m-ethoxystyrene; alkoxystyrene such as o-ethoxystyrene; p-carboxymethylstyrene; m-carboxymethylstyrene; o-carboxymethyl Examples thereof include carboxyester styrene such as styrene, alkyl ether styrene such as p-vinylbenzyl propyl ether, and the like, or a mixture of two or more thereof. Polymerization (or copolymerization) of the styrene-based monomer may be in a lump form, an aliphatic hydrocarbon such as pentane, hexane, heptane, an alicyclic hydrocarbon such as cyclohexane, or an aromatic hydrocarbon such as benzene, toluene, xylene. You may perform in a solvent. In the slurry polymerization, it is preferable to polymerize the styrene-based monomer at a high concentration in terms of productivity. In the present invention, the styrene-based monomer concentration is 50
It is preferable to carry out the polymerization at a volume ratio of at least 70%
It is more preferable to carry out the polymerization as described above. In the slurry polymerization, a polymer having a high bulk density and good impregnability and deashability with respect to the aromatic solvent polymer can be obtained. Further, the bulk polymerization is excellent in productivity and the above-mentioned impregnating property. The polymerization temperature is not particularly limited, but generally 0 to
The temperature is 100 ° C, preferably 20 to 80 ° C. Further, in order to control the molecular weight of the obtained styrene polymer, it is effective to carry out the polymerization reaction in the presence of hydrogen.

The styrene polymer thus obtained has a high syndiotactic structure. Here, the high syndiotactic structure in the styrene-based polymer is a syndiotactic structure having a high stereochemical structure, that is, a phenyl group or a substitution which is a side chain to a main chain formed from a carbon-carbon bond. Means that the phenyl groups have a three-dimensional structure that is alternately located in the opposite direction,
The tacticity is quantified by a nuclear magnetic resonance method ( ¹³ C-NMR method) using isotope carbon. ^The tacticity measured by the ¹³ C-NMR method can be indicated by the abundance ratio of a plurality of continuous structural units, for example, diad in the case of 2, triad in the case of 3 and pentad in the case of 5. However, the "styrene-based polymer having a highly syndiotactic structure" referred to in the present invention is usually 75% or more, preferably 85% or more in racemic dyad, or 30% or more in racemic pentad,
Preferably polystyrene having a syndiotacticity of 50% or more, poly (alkylstyrene), poly (halogenated styrene), poly (alkoxystyrene), poly (vinylbenzoic acid ester) and mixtures thereof, or a main component thereof. Means a copolymer. Here, as poly (alkylstyrene),
There are poly (methyl styrene), poly (ethyl styrene), poly (isopropyl styrene), poly (tertiary butyl styrene), etc., and as poly (halogenated styrene), poly (chlorostyrene), poly (bromostyrene), There are poly (fluorostyrene) and the like. Examples of poly (alkoxystyrene) include poly (methoxystyrene) and poly (ethoxystyrene). Of these, particularly preferable styrene polymers include polystyrene, poly (p-methylstyrene), poly (m-methylstyrene), poly (p-tertiarybutylstyrene), poly (p-chlorostyrene), poly ( Examples thereof include m-chlorostyrene), poly (p-fluorostyrene), and a copolymer of styrene and p-methylstyrene. In the method of the present invention, the conversion of the polymerization as described above is, for example, 60% or more, preferably 70%.
Continue until the above. The conversion rate can be adjusted by the polymerization conditions such as the catalyst used, the polymerization temperature, and the time.

In the method of the present invention, in purifying the styrene-based polymer having a high syndiotactic structure produced as described above, deashing treatment is carried out in a state in which the styrene-based polymer is dissolved in a solvent. By doing so, the catalyst component and the like remaining in the styrene polymer can be efficiently removed. Here, the solvent used for dissolving the styrene-based polymer is not particularly limited as long as it can dissolve the target styrene-based polymer, and the solvent for the polymerization reaction, the same or different styrene-based monomer as the raw material monomer. A monomer or the like can be used, but the one having a solubility parameter (SP value) of 7 to 10 (cal / cm ³ ) ^1/2 is preferable, and the SP value is more preferably 8 to 9.5 (cal / c).
m ³ ) ^1/2 is used. If the SP value is less than 7 or more than 10, the solubility of the styrene polymer decreases,
It becomes necessary to melt at high temperature. Specific examples of preferred solvents include benzene; alkylbenzenes such as toluene, xylene and ethylbenzene; and ketones such as diethyl ketone and methyl ethyl ketone. Of these, ethylbenzene is particularly preferred. Further, these solvents may be used in combination of two or more kinds. The amount of the solvent used is not particularly limited as long as it can dissolve the target styrene polymer. The melting temperature depends on the polymer composition of the target styrene-based polymer and the S of the solvent used.
Although it changes depending on the P value, etc., in the case of ethylbenzene,
The temperature is preferably 100 ° C or higher, more preferably 120 ° C or higher. As described above, the present invention performs deashing treatment in a state of being dissolved in a solvent, but the state of being dissolved in a solvent here is not limited to a completely dissolved state unless it is against the object of the present invention. Rather, it includes an incompletely dissolved state in which the styrene-based polymer exists in a partially undissolved state such as solid or dispersed.

There are various deashing agents used in this deashing treatment, and examples thereof include acidic agents such as hydrochloric acid and sulfuric acid, and basic agents such as potassium hydroxide, sodium hydroxide and ammonia. These deashing agents are in a state of phase separation with the above-mentioned dissolved styrene polymer (for example,
It is used in a liquid state that can be separated as a liquid phase immiscible with the dissolved styrene-based polymer or a solid state that can be separated as a solid phase), but it is generally used in a liquid state. Here, since the SP value of the solvent used for dissolving the styrene-based polymer is relatively determined in the relationship between the target styrene-based polymer and the solvent used, from this SP value Although it is not possible to immediately determine the proper use state of the deashing agent, when the SP value is 7 to 10, the deashing agent is usually used in an amount of 3 times mol or more of the residual metal amount in the styrene polymer. , Preferably 3 to 10 times mol, and used in a state of being dissolved in water or the like. The amount of the deashing agent used can be appropriately adjusted according to the amount of residual metal in the target styrene-based polymer, but it is preferably 3 times or more the molar amount of the above residual metal. If the amount is less than 3 times the molar amount, the demineralization property may deteriorate rapidly. On the other hand, if the amount used is extremely large, a large amount of the deashing agent remains in the styrene-based polymer after the deashing treatment, and it is necessary to remove the deashing agent.

The refining operation (deashing treatment) can be carried out by various methods. For example, (1) after adding a deashing agent to a solvent that dissolves the target styrene-based polymer, further adding styrene-based heavy Add coalescence, heat up and dissolve, and stir it, then phase-separate, or (2) add the target styrene-based polymer to the solvent to heat up and dissolve, then add a deashing agent And stirring to separate the phases. Here, when the deashing agent is used in a liquid state, a solution in which the deashing agent is dissolved in advance can be added, or a deashing agent and a liquid in which the deashing agent is dissolved can be added separately. The treatment time depends on the dispersion state or the stirring state of the styrene polymer solution, but it may be appropriately selected in the range of generally 15 minutes to 5 hours, preferably 30 minutes to 2 hours. Incidentally, when the temperature during the above dissolution operation and purification operation (deashing treatment) is high, if a styrene-based monomer is used as a solvent, a styrene-based polymer having an atactic structure is easily generated by thermal polymerization, It is preferable to use another solvent. For the same reason, when unreacted raw material monomer remains in the target styrene-based polymer, it is preferable to remove it before dissolution or add an antioxidant.

In the method of the present invention, it is also effective to perform deashing treatment by the above-mentioned method, and then, if necessary, perform washing and vacuum drying. In particular, the cleaning treatment is performed in the state where the target styrene-based polymer is dissolved in a solvent, like the deashing treatment, so that the catalyst components, the deashing agent, etc., which could not be completely removed by the deashing treatment, are efficiently treated. Can be removed well. The liquid used as the cleaning agent here may be the same as or different from the one in which the deashing agent is dissolved. Whether or not the cleaning agent is properly phase-separated can be considered in the same manner as the deashing agent described above. For example, when the SP value of the solvent that dissolves the target styrene-based polymer is 7 to 10, water or the like can usually be used as a detergent. The washing temperature needs to be higher than the temperature at which the dissolved polymer solidifies, and depends on the SP value of the solvent, but generally 80 to 150.
The temperature may be selected in the range of ° C, and the temperature may be the same as the temperature of the deashing treatment, but it is desirable to set the temperature below the boiling point of the detergent after cooling.

[0036]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. Example 1 Polymerization of styrene (SM) (SM: C: B: A) using a catalyst composed of pentamethylcyclopentadienyl titanium trimethoxide (A), methylaluminoxane (B) and triisobutylaluminum (C). = 350,000: 4
Polymerization at 00: 300: 3 (molar ratio) at 70 ° C for 3 hours)
Syndiotactic polystyrene (conversion rate 66%, catalyst residue amount: Al = 790 pp)
Purification was carried out by the following procedure using m) as a sample. 300m ethylbenzene in a 1 liter polymerization tank
1, NaOH 1 g (Na / Al ratio = 13), water 1 ml,
100 g of the above sample was charged under a nitrogen atmosphere. 15
After the temperature was raised to 0 ° C. to completely dissolve the polymer, 300 ml of water purged with nitrogen was added, and the mixture was stirred for 15 minutes, allowed to stand and separated, and the lower phase water was extracted. Add 300 ml of water again,
Washed for 15 minutes. This washing operation was repeated once more, then cooled, and the organic phase (solid) was pulverized and then dried. The residual metal content of the polymer (syndiotactic polystyrene) obtained by performing such a purification treatment was Al = 40 ppm as a result of metal analysis.

Example 2 300 ml of ethylbenzene was added to 100 g of the sample used in Example 1 and dissolved at 150 ° C., followed by water 3
1 g of NaOH in 00 ml (Na / Al ratio = 1
Example 1 except that a solution in which 3) was dissolved was added and deashing treatment was performed.
The same operation was performed. The residual metal amount of the purified polymer (syndiotactic polystyrene) was Al = 45 ppm.

Example 3 Using a catalyst composed of pentamethylcyclopentadienyl titanium trimethyl (A), N, N-dimethylanilinium tetra (pentafluorophenyl) borate (B) and triisobutylaluminum (C), Styrene (S
Polymerization of M) (SM: C: B: A = 350,000: 24)
Syndiotactic polystyrene (conversion 70%, amount of catalyst residue: Al = 260 ppm) obtained by carrying out 0: 4: 4 (molar ratio), 70 ° C., 2 hours polymerization) 1
00g was used as a sample and 0.5g of NaOH (Na
The same operation as in Example 1 was carried out except that the / Al ratio = 19). The residual metal amount of the purified polymer (syndiotactic polystyrene) was Al = 38 ppm.

Example 4 A copolymer (p) obtained by copolymerizing styrene and p-methylstyrene under the same polymerization conditions and using the same catalyst as in Example 1
-Methylstyrene content 12 mol /%, conversion 71%, catalyst residue amount: Al = 740 ppm) was used as a sample and operated in the same manner as in Example 1 (Na / Al ratio = 1).
3). The residual metal amount of the purified copolymer (syndiotactic polystyrene) was Al = 35 ppm.

Example 5 Using 100 g of the sample used in Example 3, Na
The same operation as in Example 3 was carried out except that 6.3 ml of 2N hydrochloric acid (HCl / Al ratio = 13) was added instead of OH. The residual metal amount of the purified polymer (syndiotactic polystyrene) was Al = 28 ppm.

Comparative Example 1 The same operation as in Example 1 was carried out except that NaOH was not added. The residual metal amount of the polymer (syndiotactic polystyrene) obtained by performing such treatment is Al = 5
It was 30 ppm.

Comparative Example 2 The procedure of Example 1 was repeated except that the amount of NaOH added was 0.15 g (Na / Al ratio = 1.9). The residual metal amount of the polymer (syndiotactic polystyrene) obtained by performing such treatment was Al = 450 ppm.

[0043]

According to the present invention, a styrene-based polymer obtained by polymerizing a styrene-based monomer at a high concentration and a high conversion rate is prepared.
Since it can be efficiently deashed and washed without being affected by its particle size and shape, a high-purity styrene polymer can be obtained,
The productivity of the high-purity styrene polymer can be remarkably improved. Further, according to the present invention, since the styrene-based polymer is handled in a solution state, troubles in the transfer and separation steps can be eliminated, and the processing can be stabilized and the processing equipment can be simplified. Therefore, the present invention has an extremely high industrial value as a method for efficiently producing a styrene-based polymer having a highly syndiotactic structure with high purity.

Claims (6)

[Claims] 1. A highly syndiotactic structure obtained by using a catalyst comprising (A) an aluminoxane or cation and an anion in which a plurality of groups are bound to a metal and (B) a transition metal compound. A method for purifying a styrene-based polymer, which comprises deashing a styrene-based polymer having the above in a state of being dissolved in a solvent. 2. The method for purifying a styrene-based polymer according to claim 1, wherein the solubility parameter (SP value) of the solvent is 7 to 10 (cal / cm ³ ) ^1/2 . 3. When performing deashing treatment, an acidic reagent or a basic reagent is used as a deashing agent, and the amount used is
The amount of residual metal in the styrene-based polymer having a high syndiotactic structure obtained by using the catalyst composed of the components (A) and (B) is 3 times or more moles of the residual metal.
A method for purifying a styrene-based polymer as described. 4. The SP value is 7 to 10 (cal / cm ³ ).
^The method for purifying a styrenic polymer according to claim 2, wherein the deashing agent is used in a state capable of phase separation with the solvent which is ^1/2 . 5. A method for purifying a styrene-based polymer, which comprises further carrying out a washing treatment in a state of being dissolved in a solvent after the deashing treatment according to claim 1. 6. The SP value is 7 when performing the cleaning process.
The method for purifying a styrene-based polymer according to claim 5, wherein a detergent capable of phase separation with the solvent having a concentration of 10 to 10 (cal / cm ³ ) ^1/2 is used.