Process for purification of styrenic polymer

There is disclosed a process for purifying a styrene polymer which comprises treating a highly syntiotactic styrene polymer which is produced by using a catalyst composition of (A) an aluminoxane or a specific coordination complex compound and (B) a transition metal compound with a swelling agent (e.g. ethylbenzene) and a deactivating agent (e.g. methanol, ethanol). The process is capable of efficiently purifying the styrene polymer produced by polymerizing a styrene monomer at a high concentration with a high conversion efficiency. Accordingly, the process greatly improves the industrial productivity of highly pure styrene polymer.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a process for the purification of a 
styrenic polymer. More particularly, it pertains to a process for 
efficiently purifying a styrenic polymer having a high degree of 
syndiotactic configuration in its stereochemical structure of polymer 
chain to a high level of purity. 
2. Description of the Related Arts 
Heretofore, styrenic polymers produced by the radical polymerization or the 
like have had an atactic configuration in stereostructure, have been 
molded to a variety of shapes by various molding methods such as injection 
molding, extrusion molding, blow molding, vacuum molding and cast molding 
and have been used for electrical appliances, office machines, household 
goods, packaging containers, toys, furnitures, synthetic papers and other 
industrial materials. 
Because of their atactic configuration in stereochemical structure, 
however, such styrenic polymers have suffered the disadvantage of inferior 
heat and chemical resistances. 
The group of the present inventors has previously succeeded in developing 
styrenic polymers each having a high degree of syndiotacticity and 
further, has proved that styrenic polymers having syndiotactic 
configuration are obtained by the use of a catalyst comprising a titanium 
compound and a contact product (alkylaluminoxane) of an organoaluminum 
compound with a condensing agent (refer to Japanese Patent Application 
Laid-Open No. 187708/1987). 
The above-mentioned styrenic polymers are produced by means of slurry 
polymerization, bulk polymerization or the like and preferably in a high 
concentration of styrene from the viewpoint of the catalyst activity and 
polymer productivity. In addition, it has been desired to remove the 
residual catalyst components in the obtained polymer by means of deashing 
(removal of residual catalyst). 
However, the problem still unsolved in deashing was that although the 
polymer product polymerized at a low conversion efficiency or a low 
concentration of styrene was easy to deash, the polymer with a high 
conversion efficiency, for example 60% or higher becomes difficult to 
deash and clean with increase in the conversion efficiency. 
As a means for facilitating the deashing, there is available a method in 
which a deashing agent (exemplified by a strong acid and strong base) is 
employed at the glass transition temperature (Tg) or lower of the polymer 
(Japanese Patent Application Laid-Open No. 59012/1991) or at the Tg or 
higher thereof (Japanese Patent Application Laid-Open No. 25133/1991). 
Specifically the above-mentioned method comprises the steps of 
sufficiently swelling the polymer by the use of a swelling agent in the 
presence of a deashing agent, adding a deactivating agent simultaneously 
with a swelling agent to the polymer to decompose the catalytic 
components; and then thoroughly cleaning the polymer with a cleaning 
solvent or the like. 
However, the use of an acid as the deashing agent causes the problems such 
as coloration of polymer and corrosion of a molding machine at the time of 
molding, while the use of a base brings about the problems such as 
corrosion of a molding machine at the time of molding and decomposition of 
other resins at the time of molding. As a means for solving the aforesaid 
problem, mention may be made of a method in which the polymer is cleaned 
with a large amount of a solvent. The method, however, leads to intricate, 
troublesome process and unreasonably large equipment for deashing and 
cleaning, thus causing expensive installation cost. 
Under such circumstances, intensive research and investigation were made by 
the present inventors in order to overcome the above-mentioned problem 
involved in the prior art and to develop a process wherein a styrenic 
polymer with a high conversion efficiency can be efficiently purified to a 
high level of purity. 
As the result, it has been found that the aforestated problem can be solved 
by treating the styrenic polymer to be purified with a swelling agent and 
a deactivating agent. The present invention has been accomplished on the 
basis of the foregoing finding and information. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a process for 
efficiently purifying a styrenic polymer with a high degree of 
syndiotacticity to a high level of purity. 
It is another object of the present invention to improve the productivity 
of a styrenic polymer with a high degree of syndiotacticity with enhanced 
conversion efficiency and concentration of styrenic monomer. 
Other objects of the present invention will in part be obvious and will in 
part appear hereinafter.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The process for the purification of a styrenic polymer according to the 
present invention comprises treating a styrenic polymer having a high 
degree of syndiotactic configuration which is produced by the use of a 
catalyst comprising (A) an aluminoxane or a coordination complex compound 
comprising a cation and an anion in which a plurality of radicals are 
bonded to a metal and (B) a transition metal compound with a swelling 
agent and a deactivating agent. 
The component (A) of the catalyst to be used in the present invention is, 
as mentioned above, an aluminoxane or a coordination complex compound 
comprising a cation and an anion in which a plurality of radicals are 
bonded to a metal. Here, the aluminoxane is a compound obtained by 
bringing one of various organoaluminum compounds into contact with a 
condensing agent. As the organoaluminum compound used as a starting 
material, an organoaluminum compound represented by the general formula: 
EQU AlR.sup.1.sub.3 (I) 
wherein R.sup.1 is an alkyl group having 1 to 8 carbon atoms, more 
specifically, trimethylaluminum, triethylaluminum and triisobutylaluminum 
can be mentioned, and trimethylaluminum is most desirable. 
On the other hand, a typical example of the condensing agent for said 
organoaluminum compound is water. In addition, any compounds capable of 
undergoing a condensation reaction with organoaluminum compounds including 
alkylaluminum can be used. 
As the aluminoxane of Component (A) may include chain alkylaluminoxane 
represented by the general formula: 
##STR1## 
wherein n indicates polymerization degree, and a number of 2 to 50; and 
R.sup.1 represents an alkyl group having 1 to 8 carbon atoms, 
and cycloalkylaluminoxane having the repeating unit represented by the 
general formula: 
##STR2## 
and the like. Of these alkylaluminoxanes, that wherein R.sup.1 is a methyl 
group, i.e. methylaluminoxane is particularly desirable. 
Generally, the reaction product of alkylaluminum compound such as 
trialkylaluminum and water includes the above-mentioned chain 
alkylaluminoxane and cycloalkylaluminoxane, unreacted trialkylaluminum, a 
mixture of various condensation products, and further complicatedly 
associated molecules thereof, which becomes various products according to 
the contacting conditions of the alkylaluminum compound and water. 
The reaction of the alkylaluminum compound and water is not specifically 
limited, but may be performed according to known methods; for example, (1) 
a method in which an alkylaluminum compound is dissolved in an organic 
solvent and then brought into contact with water; (2) a method in which an 
alkylaluminum compound is added at the start of polymerization, and then 
water is added; and (3) a method in which an alkylaluminium compound is 
reacted with water of crystallization as contained in metal salts and the 
like, or water absorbed in inorganic or organic compounds. The above water 
may contain ammonia, amine such as ethylamine, sulfur compound such as 
hydrogen sulfide, phosphorus compound such as phosphite and the like in 
the proportion of less than 20%, approximately. 
The aluminoxane, especially alkylaluminoxane to be used in the present 
invention is prepared by a method in which, when a hydrated compound is 
used, the resultant solid residue is filtered after the above contact 
reaction and the filtrate is heat treated under atmospheric or reduced 
pressure at a temperature of 30.degree. to 200.degree. C., preferably 
40.degree. to 150.degree. C. for from 20 minutes to 8 hours, preferably 
from 30 minutes to 5 hours while removing the solvent. The temperature for 
the heat treatment, may be determined optionally depending on various 
conditions, but usually the above range may be used. If the temperature is 
less than 30.degree. C., effects cannot be obtained, and if it exceeds 
200.degree. C., aluminoxane itself is undesirably pyrolyzed. Depending on 
the conditions of the heat treatment, the reaction product can be obtained 
as a colorless solid or solution. The product thus obtained can be used as 
a catalyst solution, if necessary, by dissolving or diluting with a 
hydrocarbon solvent. 
Suitable examples of the alkylaluminoxane are those in which the area of 
the high magnetic field component in the methyl proton signal region due 
to the aluminum-methyl group (Al-CH.sub.3) bond as observed by the proton 
nuclear magenetic resonance method is not more than 50% of the total 
signal area. That is, in a proton nuclear magnetic resonance (.sup.1 HNMR) 
spectral analysis of a solution of the alkylaluminoxane in toluene at room 
temperature, the methyl proton signal due to Al-CH.sub.3 is observed in 
the region of 1.0 to -0.5 ppm (tetramethylsilane (TMS) standard). Since 
the proton signal of TMS (0 ppm) is in the 1.0 to -0.5 ppm region of the 
methyl proton signal due to Al-CH.sub.3, the methyl proton signal due to 
Al-CH.sub.3 is measured with 2.35 ppm methyl proton signal of toluene in 
TMS standard. The methyl proton signal due to Al-CH.sub.3 is divided into 
two components: the high magnetic field component in the -0.1 to -0.5 ppm 
region and the other magnetic field component in the 1.0 to -0.1 ppm 
region. In alkylaluminoxane preferably used as component (A) of the 
catalyst in the present invention, the area of the high magnetic field 
component is not more than 50%, preferably 45 to 5% of the total signal 
area in the 1.0 to -0.5 ppm region. 
As the component (A) which constitutes the primary ingredient of the 
catalyst in the process according to the present invention, a coordination 
complex compound comprising a cation and an anion in which a plurality of 
radicals are bonded to a metal can be used in place of the aforestated 
aluminoxane. A variety of such coordination complex compounds are 
available, and those represented by the following general formulae (IV) or 
(V) are preferably employed: 
EQU (L.sup.1 -H.sup.g+).sub.h (M.sup.1 X.sup.1 X.sup.2 ---X.sup.n(n-m)-).sub.i 
(IV) 
or 
EQU (L.sup.2g+).sub.h (M.sup.2 X.sup.1 X.sup.2 ---X.sup.n(n-m)-).sub.i (V) 
wherein L.sup.2 is M.sup.3, T.sup.1 T.sup.2 M.sup.4 or T.sup.3.sub.3 C as 
hereinafter described; L.sub.1 is a Lewis base; M.sup.1 and M.sup.2 are 
each a metal selected from Groups 5 to 15 of the Periodic Table; M.sup.3 
is a metal selected from Groups 8 to 12 of the Periodic Table; M.sup.4 is 
a metal selected from Groups 8 to 10 of the Periodic Table; X.sup.1 to 
X.sup.n are each a hydrogen atom, dialkylamino group, alkoxy group, 
aryloxy group, alkyl group having 1 to 20 carbon atoms, aryl group having 
6 to 20 carbon atoms, alkylaryl group having 7 to 20 carbon atoms, 
arylalkyl group having 7 to 20 carbon atoms, substituted alkyl group, 
organometalloid group or halogen atom; T.sup.1 and T.sup.2 are each a 
cyclopentadienyl group, substituted cyclopentadienyl group, indenyl group 
or fluorenyl group; T.sup.3 is an alkyl group; m is the valency of each of 
M.sup.1 and M.sup.2 indicating an integer of 1 to 7; n is an integer of 2 
to 8; g is the ion valency of each of L.sup.1 -H and [L.sup.2 ], 
indicating an integer of 1 to 7; h is an integer of 1 or more; and 
i=hxg/(n-m). 
Specific examples of M.sup.1 and M.sup.2 include B, Al, Si, P, As, Sb, 
etc.; those of M.sup.3 include Ag, Cu, etc.; and those of M.sup.4 include 
Fe, Co, Ni, etc. Specific examples of X.sup.1 to X.sup.n include 
dialkylamino group such as dimethylamino and diethylamino; alkoxyl group 
such as methoxy, ethoxy and n-butoxy; aryloxy group such as phenoxy, 
2,6-dimethylphenoxy and naphthyloxy; alkyl group having 1 to 20 carbon 
atoms such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, n-octyl and 
2-ethylhexyl; aryl group having 6 to 20 carbon atoms, alkylaryl group or 
arylalkyl group such as phenyl, p-tolyl, benzyl, pentafluorophenyl, 
3,5-di(trifluoromethyl)phenyl, 4-tert-butylphenyl, 2,6-dimethylphenyl, 
3,5-dimethylphenyl, 2,4-dimethylphenyl and 1,2-dimethylphenyl; halogen 
such as F, Cl, Br and I; and organometalloid group such as 
pentamethylantimony group, trimethylsilyl group, trimethylgermyl group, 
diphenylarsine group, dicyclohexylantimony group and diphenylboron group. 
Specific examples of substituted cyclopentadienyl of R.sup.5 and R.sup.6 
include methylcyclopentadienyl, butylcyclopentadienyl and 
pentamethylcyclopentadienyl. 
Among the compounds represented by the above-mentioned general formula (IV) 
or (V) specific examples of preferably usable compounds include, as the 
compound of general formula (IV), triethylammonium tetraphenylborate, 
tri(n-butyl)ammonium tetraphenylborate, trimethylammonium 
tetraphenylborate, triethylammonium tetra(pentafluorophenyl)borate, 
tri(n-butyl)ammonium tetra(pentafluorophenyl)borate, triethylammonium 
hexafluoroarsenate, etc., and as the compound of general formula (V), 
pyridinium tetra(pentafluorophenyl)borate, pyrrolium 
tetra(pentafluorophenyl)borate, N,N-dimethylanilinium 
tetra(pentafluorophenyl)borate, methyldiphenylammonium 
tetra(pentafluorophenyl)borate, ferrocenium tetraphenylborate, 
dimethylferrocenium tetra(pentafluorophenyl)borate, ferrocenium 
tetra(pentafluorophenyl)borate, decamethylferrocenium 
tetra(pentafluorophenyl)borate, acetylferrocenium 
tetra(pentafluorophenyl)borate, formylferrocenium 
tetra(pentafluorophenyl)borate, cyanoferrocenium 
tetra(pentafluorophenyl)borate, silver tetraphenylborate, silver 
tetra(pentafluorophenyl)borate, trityltetraphenylborate, 
trityltetra(pentafluorophenyl)borate, silver hexafluoroarsenate, silver 
hexafluoroantimonate, silver tetrafluoroborate, triphenylcarbenium 
tetra(pentafluorophenyl)borate, etc. 
As the transition metal compound of component (B) of the catalyst used in 
the present invention, mention may be made of the compound of the metals 
in Groups 3 to 6 of the Periodic Table and lanthanum series, of which are 
preferable compounds of the metals in Group 4 (titanium zirconium hafnium, 
vanadium, etc.). Various titanium compound are available and a preferred 
example is at least one compound selected from the group consisting of 
titanium compounds and titanium chelate compounds represented by the 
general formula: 
EQU TiR.sup.2.sub.a T.sup.3.sub.b R.sup.4.sub.c R.sup.5.sub.4-(a+b+c) (VI) 
or 
EQU TiR.sup.2.sub.d R.sup.3.sub.e R.sup.4.sub.3-(d+e) (VII) 
wherein R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each a hydrogen atom, an 
alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 
carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl 
group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 
carbon atoms, an acyloxy group having 1 to 20 carbon atoms, a 
cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl 
group or a halogen atom; a, b and c are each an integer of 0 to 4; and d 
and e are each an integer of 0 to 3. 
R.sup.2, R.sup.3, R.sup.4 and R.sup.5 in the formulae (VI) and (VII) each 
represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms 
(specifically, methyl group, ethyl group, propyl group, butyl group, amyl 
group, isoamyl group, isobutyl group octyl group and 2-ethylhexyl group), 
an alkoxy group, having 1 to 20 carbon atoms (specifically, methoxy group, 
ethoxy group, propoxy group, butoxy group, amyloxy group, hexyloxy group, 
and 2-ethylhexyloxy group), an aryl group having 6 to 20 carbon atoms, an 
alkylaryl group, an arylalkyl group (specifically, phenyl group, tolyl 
group, xylyl group and benzyl group), an acyloxy group having 1 to 20 
carbon atoms (specifically, heptadecylcarbonyloxy group), a 
cyclopentadienyl group, a substituted cyclopentadienyl group 
(specifically, methylcyclopentadienyl group, 1,2-dimethylcyclopentadienyl 
group and pentamethylcyclopentadienyl group), an indenyl group or a 
halogen atom (specifically, chlorine, bromine, iodine and fluorine). These 
R.sup.2 R.sup.3, R.sup.4 and R.sup.5 may be the same as or different from 
each other. Furthermore, a, b and c each are an integer of 0 to 4, and d 
and e each are an integer of 0 to 3. 
More preferred titanium compounds include a titanium compound represented 
by the formula: 
EQU TiRXYZ (VIII) 
wherein R represents a cyclopentadienyl group, a substituted 
cyclopentadienyl group or an indenyl group; X, Y and Z are 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, an arylalkyl group having 7 to 
20 carbon atoms or a halogen atom. 
The substituted cyclopentadienyl group represented by R in the above 
formula is, for example, a cyclopentadienyl group substituted by at least 
one of an alkyl group having 1 to 6 carbon atoms, more specifically, 
methylcyclopentadienyl group, 1,2-dimethylcyclopentadienyl group and 
pentamethylcyclopentadienyl group. In addition, 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 and 2-ethylhexyl 
group), an alkoxy group having 1 to 12 carbon atoms (specifically, methoxy 
group ethoxy group, propoxy group, butoxy group, amyloxy group, hexyloxy 
group, octyloxy group and 2-ethylhexyl group), an aryl group having 6 to 
20 carbon atoms (specifically, phenyl group and naphthyl group), an 
aryloxy group having 6 to 20 carbon atoms (specifically, phenoxy group), 
an arylalkyl group having 7 to 20 carbon atoms (specifically, benzyl 
group) or a halogen atom (specifically, chlorine, bromine, iodine and 
fluorine). 
Specific examples of the titanium compound represented by the formula 
(VIII) include cyclopentadienyltrimethyltitanium, 
cyclopentadienyltriethyltitanium, cyclopentadienyltripropyltitanium, 
cyclopentadienyltributyltitanium, methylcyclopentadienyltrimethyltitanium, 
1,2-dimethylcyclopentadienyltrimethyltitanium, 
pentamethylcyclopentadienyltrimethyltitanium, 
pentamethylcyclopentadienyltriethyltitanium, 
pentamethylcyclopentadienyltripropyltitanium, 
pentamethylcyclopentadienyltributyltitanium, 
cyclopentadienylmethyltitanium dichloride, cyclopentadienylethyltitanium 
dichloride, pentamethylcyclopentadienylmethyltitanium dichloride, 
pentamethylcyclopentadienylethyltitanium dichloride, 
cyclopentadienyldimethyltitanium monochloride, 
cyclopentadienyldiethyltitanium monochloride, cyclopentadienyltitanium 
trimethoxide, cyclopentadienyltitanium triethoxide, 
cyclopentadienyltitanium tripropoxide, cyclopentadienyltitanium 
triphenoxide, pentamethylcyclopentadienyltitanium trimethoxide, 
pentamethylcyclopentadienyltitanium triethoxide, 
pentamethylcyclopentadienyltitanium tripropoxide, 
pentamethylcyclopentadienyltitanium tributoxide, 
pentamethylcyclopentadienyltitanium triphenoxide, cyclopentadienyltitanium 
trichloride, pentamethylcyclopentadienyltitanium trichloride, 
cyclopentadienylmethoxytitanium dichloride, 
cyclopentadienyldimethoxytitanium monochloride, 
pentamethylcyclopentadienylmethoxytitnaium dichloride, 
cyclopentadienyltribenzyltitanium, 
pentamethylcyclopentadienylmethyldiethoxytitanium, indenyltitanium 
trichloride, indenyltitanium trimethoxide, indenyltitanium triethoxide, 
indenyltrimethyltitanium and indenyltribenzyltitanium. 
Of these titanium compounds, a compound not containing halogen atom is 
preferred and a titanium compound having one .pi.-electron type ligand as 
mentioned above is particularly preferred. 
Furthermore, a condensed titanium compound represented by the following 
formula can be used as the titanium compound. 
##STR3## 
wherein R.sup.6 and R.sup.7 each represent a halogen atom, an alkoxy group 
having 1 to 20 carbon atoms or an acyloxy group having 1 to 20 carbon 
atoms; and k is an integer of 2 to 20. 
Furthermore, the above titanium compounds can be used in the form of a 
complex formed with an ester or an ether. 
The trivalent titanium compound represented by the formula (VII) typically 
includes a trihalogenated titanium such as titanium trichloride; and a 
cyclopentadienyltitanium compound such as cyclopentadienyltitanium 
dichloride, and also those obtained by reducing a tetravalent titanium 
compound. These trivalent titanium compounds can be used in the form of a 
complex formed with an ester or an ether. 
In addition, the zirconium compound used as the transition metal compound 
includes tetrabenzylzirconium, zirconium tetraethoxide, zirconium 
tetrabutoxide, bisindenylzirconium dichloride, triisopropoxyzirconium 
monochloride, zirconium benzyl dichloride and tributoxyzirconium 
monochloride, hafnium compound includes tetrabenzyl hafnium, tetraethoxide 
hafnium and tetrabutoxide hafnium, and vanadium compound includes vanadyl 
bisacetylacetonato, vanadyl triacetylacetonato, vanadyl triethoxide and 
vanadyl tripropoxide. Of these transition metal compounds, the titnaium 
compounds are particularly desirable. 
As the transition metal compound which constitutes the component (B) of the 
catalyst, there may be used a transition metal compound with two ligands 
having conjugated .pi. electrons, for example, at least one compound 
selected from the group consisting of the transition metal compound 
represented by the general formula: 
EQU M.sup.5 R.sup.8 R.sup.9 R.sup.10 R.sup.11 (X) 
wherein M.sup.5 is titanium, zirconium or hafnium; R.sup.8 and R.sup.9 are 
each a cyclopentadienyl group, substituted cyclopentadienyl group, indenyl 
group or fluorenyl group; and R.sup.10 and R.sup.11 are each a hydrogen 
atom, halogen, hydrocarbon radical having 1 to 20 carbon atoms, alkoxy 
group having 1 to 20 carbon atoms, amino group or thioalkoxy group having 
1 to 20 carbon atoms, but R.sup.8 and R.sup.9 may be each cross-linked by 
a hydrocarbon radical having 1 to 5 carbon atoms, alkylsilyl group having 
1 to 20 carbon atoms and 1 to 5 silicon atoms or germanium-containing 
hydrocarbon group having 1 to 20 carbon atoms and 1 to 5 germanium atoms. 
In more detail, each of R.sup.8 and R.sup.9 designates a cyclopentadienyl 
group, substituted cyclopentadienyl group, more 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-butylcyclopentadienyl group; 1,3-di(tert-butyl)cyclopentadienyl 
group; 1,2,4-tri(tert-butyl)cyclopentadienyl group or the like, indenyl 
group, substituted indenyl group, more specifically, methylindenyl group; 
dimethylindenyl group; trimethylindenyl group or the like, fluorenyl 
group, or substituted fluorenyl group such as methylfluorenyl group, and 
may be the same or different and cross-linked by an alkylidene group 
having 1 to 5 carbon atoms, more specifically, methylidyne group; 
ethylidene group; propylidene group; dimethylcarbyl group or the like, or 
an alkylsilyl group having 1 to 20 carbon atoms and 1 to 5 silicon atoms, 
more specifically, dimethylsilyl group; diethylsilyl group; dibenzylsilyl 
group or the like. Each of R.sup.10 and R.sup.11 independently indicates, 
as described above but more specifically, a hydrogen atom; an alkyl group 
having 1 to 20 carbon atoms such as methyl group, ethyl group propyl 
group, n-butyl group, isobutyl group, amyl group, isoamyl group, octyl 
group or 2-ethylhexyl group; an aryl group having 6 to 20 carbon atoms 
such as phenyl group or naphthyl group; an arylalkyl group having 7 to 20 
carbon atoms such as benzyl group; an alkoxyl group having 1 to 20 carbon 
atoms such as methoxyl group, ethoxyl group, propoxyl group, butoxyl 
group, amyloxy group, hexyloxy group octyloxy group or 2-ethylhexyloxy 
group; an aryloxy group having 6 to 20 carbon atoms such as phenoxy group; 
an amino group; or a thioalkoxyl group having 1 to 20 carbon atoms. 
Specific examples of the transition-metal compounds represented by the 
general formula (X) include bis(cyclopentadienyl)dimethyltitanium; 
bis(cyclopentadienyl) diethyltitanium; 
bis(cyclopentadienyl)dipropyltitanium; 
bis(cyclopentadienyl)dibutyltitanium; 
bis(methylcyclopentadienyl)dimethylyiysnium; 
bis(tertbutylcyclopentadienyl)dimethyltitanium; 
bis(1,3dimethylcyclopentadienyl)dimethyltitanium; 
bis(1,3-di-tert-butylcyclopentadienyl)dimethyltitanium; 
bis(1,2,4-trimethylcyclopentadienyl)dimethyltitanium; 
bis(1,2,3,4-tetramethylcyclopentadienyl)dimethyltitanium; 
bis(trimethylsilylcyclopentadienyl)dimethyltitanium; 
bis(1,3-di(trimethylsilyl)cyclopentadienyl)dimethyltitanium; 
bis(1,2,4-tri(trimethylsilyl)cyclopentadienyl)dimethyltitanium; 
bis(indenyl)dimethyltitanium; bis(fluorenyl)dimethyltitanium; 
methylenebis(cyclopentadienyl)dimethyltitanium; 
ethylidenebis(cyclopentadienyl)dimethyltitanium; 
methylenebis(2,3,4,5-tetramethylcyclopentadienyl) dimethyltitanium; 
ethylidenebis(2,3,4,5-tetramethylcyclopentadienyl)dimethyltitanium; 
dimethylsilylbis(2,3,4,5-tetramethylcyclopentadienyl)dimethyltitanium; 
methylenebisindenyldimethyltitanium; ethylidenebisindenyldimethyltitanium; 
dimethylsilylbisindenyldimethyltitanium; 
methylenebisfluorenyldimethyltitanium; 
ethylidenbisfluorenyldimethyltitanium; 
dimethylsilylbisfluorenyldimethyltitanium; 
methylene(tert-butylcyclopentadienyl)(cyclopentadienyl)dimethyltitanium; 
methylene(cyclopentadienyl)(indenyl)dimethyltitanium; 
ethylidene(cyclopentadienyl)(indenyl)dimethyltitanium; 
dimethylsilyl(cyclopentadienyl)(indenyl)dimethyltitanium; 
methylene(cyclopentadienyl)(fluorenyl)dimethyltitanium; 
ethylidene(cyclopentadienyl)(fluorenyl)dimethyltitanium; 
dimethylsilyl(cyclopentadienyl)(fluorenyl)dimethyltitanium; 
methylene(indenyl)(fluorenyl)dimethyltitanium; 
ethylidene(indenyl)(fluorenyl)dimethyltitanium; 
dimethylsilyl(indenyl)(fluorenyl)dimethyltitanium; 
bis(cyclopentadienyl)dibenzyltitanium; 
bis(tertbutylcyclopentadienyl)dibenzyltitanium; 
bis(methylcyclopentadienyl)dibenzyltitanium; 
bis(1,3-dimethylcyclopentadienyl)dibenzyltitanium; 
bis(1,2,4-trimethylcyclopentadienyl)dibenzyltitanium; 
bis(1,2,3,4-tetramethylcyclopentadienyl)dibenzyltitanium; 
bis(pentamethylcyclopentadienyl)dibenzyltitanium; 
bis(trimethylsilylcyclopentadienyl)dibenzyltitanium; bis 
1,3-di-(trimethylsilyl)cyclopentadienyl dibenzyltitanium; bis 
1,2,4-tri(trimethylsilyl)cyclopentadienyl dibenzyltitanium; 
bis(indenyl)dibenzyltitanium; bis(fluorenyl)dibenzyltitanium; 
methylenebis(cyclopentadienyl)dibenzyltitanium; 
ethylidenebis(cyclopentadienyl)dibenzyltitanium; 
methylenebis(2,3,4,5-tetramethylcyclopentadienyl)dibenzyltitanium; 
ethylidenebis(2,3,4,5-tetramethylcyclopentadienyl) dibenzyltitanium; 
dimethylsilylbis(2,3,4,5-tetramethylcyclopentadienyl)dibenzyltitanium; 
methylenebis(indenyl)dibenzyltitanium; 
ethylidenebis(indenyl)dibenzyltitanium; 
dimethylsilylbis(indenyl)dibenzyltitanium; 
methylenebis(fluorenyl)dibenzyltitanium; 
ethylidenebis(fluorenyl)dibenzyltitanium; 
dimethylsilylbis(fluorenyl)dibenzyltitanium; 
methylene(cyclopentadienyl)(indenyl)benzyltitanium; 
ethylidene(cyclopentadienyl)(indenyl)benzyltitanium; 
dimethylsilyl(cyclopentadienyl)(indenyl)dibenzyltitanium; 
methylene(cyclopentadienyl)(fluorenyl)dibenzyltitanium; 
ethylidene(cyclopentadienyl)(fluorenyl)dibenzyltitanium; 
dimethylsilyl(cyclopentadienyl)(fluorenyl)dibenzyltitanium; 
methylene(indenyl)(fluorenyl)dibenzyltitanium; 
ethylidene(indenyl)(fluorenyl)dibenzyltitanium; 
dimethylsilyl(indenyl)(fluorenyl)dibenzyltitanium; 
biscyclopentadienyltitanium dimethoxide; biscyclopentadienyltitanium 
diethoxide; biscyclopentadienyltitanium dipropoxide; 
biscyclopentadienyltitanium dibutoxide; biscyclopentadienyltitanium 
dipheoxide; bis(methylcyclopentadienyl)titanium dimethoxide; 
bis(1,3-dimethylcyclopentadienyl)titanium dimethoxide; 
bis(1,2,4-trimethylcyclopentadienyl)titanium dimethoxide; 
bis(1,2,3,4-tetramethylcyclopentadienyl)titanium dimethoxide; 
bispentamethylcyclopentadienyltitanium dimethoxide; 
bis(trimethylsilylcyclopentadienyl)titanium dimethoxide; bis 
1,3-di-(trimethylsilyl)cyclopentadienyl titanium dimethoxide; bis 
1,2,4-tri(trimethylsilyl)cyclopentadienyl titanium dimethoxide; 
bisindenyltitanium dimethoxide; bisfluorenyltitanium dimethoxide; 
methylenebiscyclopentadienyltitanium dimethoxide; 
ethylidenebiscyclopentadienyltitanium dimethoxide; 
methylenebis(2,3,4,5-tetramethylcyclopentadienyl)titanium dimethoxide; 
ethylidenebis(2,3,4,5tetramethylcyclopentadienyl)titanium dimethoxide; 
dimethylsilylbis(2,3,4,5-tetramethylcyclopentadienyl)titanium dimethoxide; 
methylenebisindenyltitanium dimethoxide; 
methylenebis(methylindenyl)titanium dimethoxide; 
ethylidenebisindenyltitanium dimethoxide; dimethylsilylbisindenyltitanium 
dimethoxide; methylenebisfluorenyltitanium dimethoxide; 
methylenebis(methylfluorenyl)titanium dimethoxide; 
ethylidenebisfluorenyltitanium dimethoxide; 
dimethylsilylbisfluorenyltitanium 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 dimethoxide; 
ethylidene(indenyl)(fluorenyl)titanium dimethoxide; 
dimethylsilyl(indenyl)(fluorenyl)titanium dimethoxide, etc. 
Examples of the transition metal compounds represented by the formula (X) 
wherein M.sup.5 is zirconium include 
ethylidenebiscyclopentadienylzirconium dimethoxide, 
dimethylsilylbiscyclopentadienylzirconium dimethoxide, etc. Examples of 
the hafnium compounds according to the general formula (X ) include 
ethylidenebiscyclopentadienylhafnium dimethoxide, 
dimethylsilylbiscyclopentadienylhafnium dimethoxide, etc. Particularly 
desirable transition-metal compounds among them are titanium compounds. 
In addition to the combinations of the above, the compound may be a 
bidentate coordination complex such as 
2,2'-thiobis(4-methyl-6-tert-butylphenyl)titanium diisopropoxide and 
2,2'-thiobis(4-methyl-6-tertbutylphenyl)titanium dimethoxide. 
In the process of the present invention, if desired, in addition to the 
above components (A) and (B), another catalytic components such as 
organoaluminum can be added. 
The organoaluminum includes and organoaluminum compound represented by the 
formula: 
EQU R.sup.12.sub.j Al(OR.sup.13).sub.x H.sub.y X'.sub.z (XI) 
wherein R.sup.12 and R.sup.13 each independently represent an alkyl group 
having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms; X' represents 
a halogen; j, x, y and z are 0&lt;O&lt;j.ltoreq.3, 0.ltoreq.x&lt;3, 0.ltoreq.y&lt;3 
and 0.ltoreq.z&lt;3, respectively, and j+x+y+z=3. The activity of the 
catalyst is further improved by adding the above compound. 
The organoaluminum compound represented by the above formula (XI) can be 
exemplified as shown below. Those corresponding to y=z=0 are represented 
by the formula: R.sup.12.sub.j Al(OR.sup.13).sub.3-j, wherein R.sup.12 and 
R.sup.13 are the same as those mentioned above and j is preferably a 
number of 1.5.ltoreq.j.ltoreq.3. Those corresponding to x=y=0 are 
represented by the formula: R.sup.12.sub.j AlX'.sub.3-j, wherein R.sup.12 
and X' are the same as those mentioned above and j is preferably a number 
of 0&lt;j&lt;3. Those corresponding to x=z=0 are represented by the formula: 
R.sup.12.sub.j AlH.sub.3-j, wherein R.sup.12 is the same as mentioned 
above and j is preferably a number of 2.ltoreq.j&lt;3. Those corresponding to 
y=0 are represented by the formula: R.sup.12.sub.j Al(OR.sup.13)X'.sub.z, 
wherein R.sup.12, R.sup.13 and X' are the same as those mentioned above 
and 0&lt;j.ltoreq.3, 0.ltoreq.x&lt;3, 0.ltoreq.z&lt;3 and j+x+z=3. 
In the organic aluminum compound represented by the formula (XI), the 
compound wherein y=z=0 and j=3 is selected from, for example, 
trialkylaluminum such as trimethylaluminum, triethylaluminum and 
tributylaluminum, or combination thereof. In the case of y=z=0 and 
1.51.ltoreq.j&lt;3, included are dialkylaluminum alkoxide such as 
diethylaluminum ethoxide and dibutylaluminum butoxide; alkylaluminum 
sesquialkoxide such as ethylaluminum sesquiethoxide and butylaluminum 
sesquibutoxide; as well as partially alkoxylated alkylaluminum having an 
average composition represented by R.sup.12.sub.2.5 Al(OR.sup.13).sub.0.5. 
Examples of the compound corresponding to the case where x=y=0 include a 
partially halogenated alkylaluminum including dialkylaluminum halogenide 
(j=2) such as diethylaluminum monochloride, dibutylaluminum monochloride 
and diethylaluminum monobromide; alkylaluminum sesquihalogenide (j=1.5) 
such as ethylaluminum sesquichloride, butylaluminum sesquichloride and 
ethylaluminum sesquibromide; and alkylaluminum dihalogenide (j=1) such as 
ethylaluminum dichloride, propylaluminum dichloride and butylaluminum 
dibromide. Examples of the compound corresponding to the case in which 
x=z=0 includes a partially hydrogenated alkylaluminum including 
dialkylaluminum hydride (j=2) such as diethylaluminum hydride and 
dibutylaluminum hydride; alkylaluminum dihydride (x= 1) such as 
ethylaluminum dihydride and propylaluminum dihydride. Examples of the 
compound corresponding to the case in which y=0 include a partially 
alkoxylated or halogenated alkylaluminum such as ethylaluminumethoxy 
chloride, butylaluminumbutoxy chloride and ethylaluminumethoxy bromide 
(j=x=z=1). Of these, triisobutylaluminum and triisobutylaluminum hydride 
are particularly suitable. 
The catalyst to be used in the present invention comprises Components (A) 
and (B) as the main components, and in addition, other catalytic 
components can be added if desired. The ratio of Components (A) and (B) in 
the catalyst varies depending on various conditions, and cannot be 
unequivocally defined, but usually it is, in terms of the molar ratio of 
the metal in Component (B) to the metal in Component (A), 1:1 to 
1:10.sup.6, preferably 1:10 to 1:10.sup.4 for aluminoxane; 0.1:1 to 1:0.1 
for the coordination complex compound in which a plurality of radicals are 
bonded to a metal; and the molar ratio of Component (B) to the 
organoaluminum is 1:0.1 to 1:10.sup.3 in the case where the organoaluminum 
compound represented by the general formula (XI) is added thereto. 
In order to produce a styrenic polymer, styrenic monomer/s are polymerized 
or copolymerized in the presence of a catalyst comprising the above 
components (A) and (B) as primary components. 
The styrenic monomer to be used in the present invention indicates styrene 
and/or styrene derivatives. 
Specific examples of the styrene derivatives include alkylstyrenes such as 
p-methylstyrene, m-methylstyrene, o-methylstyrene, 2,4-dimethylstyrene, 
2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, 
p-ethylstyrene, m-ethylstyrene and p-tertiary-butylstyrene; halogenated 
styrenes such as p-chlorostyrene, m-chlorostyrene, o-chlorostyrene, 
p-bromostyrene, m-bromostyrene, o-bromostyrene, p-fluorostyrene, 
m-fluorostyrene, o-fluorostyrene and o-methyl-p-fluorostyrene; 
alkoxystyrenes such as p-methoxystyrene, m-methoxystyrene, 
o-methoxystyrene, p-ethoxystyrene, m-ethoxystyrene, and o-ethoxystyrene; 
carboxyesterstyrenes such as p-carboxymethylstyrene, 
m-carboxymethylstyrene, and o-carboxymethylstyrene; alkyl etherstyrenes 
such as p-vinylbenzylpropylether; or mixtures of two or more kinds of 
them. 
The polymerization (or copolymerization) of styrenic monomer may be bulk 
polymerization, and may be carried out in a solvent of aliphatic 
hydrocarbon such as pentane, hexane, and heptane; alicyclic hydrocarbon 
such as cyclohexane; or aromatic hydrocarbon such as benzene, toluene and 
xylene. In view of productivity, it is preferred to polymerize styrenic 
monomer in a high concentration in the case of slurry polymerization. 
In the present invention, polymerization of styrenic monomer is effected 
desirably with a styrenic monomer concentration of 50% by volume or higher 
and more desirably 70% by volume or higher. 
Bulk polymerization is excellent in productivity and impregnancy. 
Conditions for polymerization in the present invention are not limited 
particularly, but can be performed in the conventional manner; for 
example, at a temperature of 0.degree. to 100.degree. C., preferably 
20.degree. to 80.degree. C. 
The styrenic polymer thus obtained has a high degree of syndiotactic 
configuration. 
Here, the styrenic polymer which has a high degree of the syndiotactic 
configuration means that its stereochemical structure is of high degree of 
syndiotactic configuration, i,e. the stereostructure in which phenyl 
groups or substituted phenyl groups as side chains are located alternately 
at opposite directions relative to the main chain consisting of 
carbon-carbon bonds. Tacticity is quantitatively determined by the nuclear 
magnetic resonance method (.sup.13 C-NMR method) using carbon isotope. The 
tacticity as determined by the .sup.13 C-NMR method can be indicated in 
terms of proportions of structural units continuously connected to each 
other, i.e., a diad in which two structural units are connected to each 
other, a triad in which three structural units are connected to each other 
and a pentad in which five structural units are connected to each other. 
The styrenic polymers having such a high degree of sundiotactic 
configuration as mentioned in the present invention usually means 
polystyrene, poly(alkylstyrene), poly(halogenated styrene), 
poly(alkoxystyrene), poly(vinyl benzoate), the mixture thereof, and 
copolymers containing the above polymers as main components, having such a 
syndiotacticity that the proportion of racemic diad is at least 75%, 
preferably at least 85%, or the proportion of racemic pentad is at least 
30%, preferably at least 50%. The poly(alkylstyrene) includes 
poly(methylstyrene), poly(ethylstyrene), poly(isopropylstyrene), 
poly(tert-butylstyrene). Poly(halogenated styrene) includes 
poly(chlorostyrene), poly(bromostyrene), and poly(fluorostyrene). 
Poly(alkoxystyrene) includes poly(methoxystyrene), and 
poly(ethoxystyrene). 
The most desirable styrenic polymers are polystyrene, 
poly(p-methylstyrene), poly(m-methylstyrene), poly(p-tertbutylstyrene), 
poly(p-chlorostyrene), poly(m-chlorostyrene), poly(p-fluorostyrene), and 
the copolymer of styrene and p-methylstyrene. 
In the process according to the present invention, the polymerization 
reaction is continued until the conversion to polymer reaches, for 
example, 60% and preferably 70% or higher. The conversion to polymer can 
be controlled by various polymerization conditions such as the catalyst to 
be used, polymerization temperature and polymerization time. 
According to the present invention, in the case of purifying the styrenic 
polymer having a high degree of syndiotactic configuration thus produced, 
the residual catalyst components and the like in the produced styrenic 
polymer can be effectively removed by treating the polymer by the use of a 
swelling agent and a deactivating agent. 
There are available various methods of purifying treatment, which are 
exemplified by a method wherein swelling and deactivation are carried out 
separately and a method wherein swelling is performed simultaneously with 
deactivation, of which is preferable the latter method. The former method 
complicates the treatment steps and besides, involves the possibility that 
after the swelling step, the once swollen polymer contracts in a cleaning 
solvent. 
The swelling agent to be used herein has a solubility parameter (SP value) 
of desirably 7 to 10 (cal/cm.sup.3).sup.1/2, more desirably 8 to 9.5 
(cal/cm.sup.3).sup.1/2. The swelling agent to be used is not specifically 
limited in the type and exemplified by an aromatic solvent such as 
benzene, toluene, ethylbenzene, xylene and styrene, of which are 
preferable toluene, xyelene and ethylbenzene; and an aliphatic solvent 
such as cyclohexane and methyl ethyl ketone, of which is preferable 
cyclohexane. 
The amount of such a swelling agent to be added to the polymer may be 
selected in accordance with a variety of conditions and is usually 
adjusted so as to attain a degree of swelling of the styrenic polymer in 
the range of 5 to 55%, preferably 10 to 30%. The swelling treatment is 
usually carried out at a temperature of 30.degree. to 200.degree. C., 
desirable 50.degree. to 150.degree. C., more desirably 80.degree. to 
130.degree. C. The above-mentioned degree of swelling (V.sub.c) is 
calculated by the following formula 
EQU V.sub.c =100(V-V.sub.o)/V.sub.o (% by volume) 
wherein V.sub.o is the apparent volume obtained by the steps of gently 
shaking or leaving polymer particles having a particle size of 0.7 to 1.7 
mm in a solvent at 20.degree. C. until an equilibrium state is attained, 
thereafter once floating the polymer particles and finally subjecting the 
particles to natural sedimentation; and V is the apparent volume obtained 
by the steps same as above except that polymer particles are treated at a 
prescribed temperature. 
The deactivating agent has preferably an active hydrogen and exemplified by 
an alcohol having 1 to 6 carbon atoms, an amine and water, of which is 
preferable an alcohol having 1 to 6 carbon atoms. The amount of such 
deactivating agent to be added to the polymer is not specifically limited 
but, in short, may only be adjusted to an amount sufficient to deactivate 
the catalyst, usually to an amount not smaller than the amount of the 
catalyst in mole used for the polymerization. 
In the above-mentioned purifying treatment, the aforestated swelling agent 
and deactivating agent are preferably added at the same time, as described 
hereinbefore, to the polymerization reaction system containing the 
styrenic polymer thus produced. As the swelling agent, the solvent for the 
polymerization reaction may be used as such, but in the purifying 
treatment, it is preferable to newly add to the treatment system a 
swelling agent that may be the same as or different from the solvent for 
the reaction. 
In the purifying treatment in which the swelling agent is added to the 
treatment system simultaneously with the deactivating agent, the treatment 
time is not specifically limited but preferably satisfies the following 
relation (Degree of swelling in % by volume/100).times.(treatment time 
with deactivating agent in mimute)=1 to 30, preferably 5 to 15. 
As is seen from the relation, degree of swelling is inversely proportional 
to treating time with deactivating agent and therefore, the treating time 
should be increased with a decrease in the degree of swelling. 
It is effective in the process of the present invention to carry out when 
necessary cleaning (filtration) and vacuum drying after the purifying 
treatment by the above-described procedure. The solvent to be used in 
cleaning may be the same as or different form the swelling agent. The 
cleaning temperature may be selected in the range of 0.degree. to 
150.degree. C. and not lower than the glass transition temperature of the 
styrenic polymer, but is preferably determined at a temperature not higher 
than the boiling point of the cleaning solvent after cooling. 
According to the process of the present invention, a highly pure and 
high-grade styrenic polymer can be obtained without the use of a deashing 
agent by adding the swelling agent and the deactivating agent to the 
styrenic polymer produced in the polymerization reaction system in the 
presence of a polymerization catalyst. Consequently, the process of the 
present invention is of industrially great value as the process for 
efficiently producing a highly pure styrenic polymer having a high degree 
of syndiotactic configuration. 
In the following, the present invention will be described in more detail 
with reference to the nonlimitative examples and comparative examples. 
Example 1 
By the use of the catalyst consisting of 
pentamethylcyclopentadienyltitanium trimethoxide (a), 
N,N-dimethylanilinium tetra(pentafluorophenyl)borate (b) and 
triisobutylaluminum (c) at a molar ratio, SM (styrene monomer) : c: b: 
a=350,000:240: 4: 4, SM was polymerized at 70.degree. C. for 2 hours into 
a polymer (syndiotactic polystyrne) at a conversion efficiency of 70%. A 
one (1) liter pressure vessel was charged with 100 g of the resultant 
polymer in an atmosphere of nitrogen and then with 300 ml of ethylbenzene 
and 300 ml of methanol. The mixture in the vessel was heated to 
110.degree. C. with stirring, and maintained thereat for 30 minutes, 
followed by cooling, filtering and vacuum drying. The polymer thus 
obtained as the sample was injection molded, and the resultant molding was 
tested to measure the amount of residual metal components and YI 
(yellowness index). The results obtained are given in Table 1. 
Example 2 
A one (1) liter pressure vessel was charged with 100 g of the polymer as 
obtained in Example 1 in an atmosphere of nitrogen and then with 300 ml of 
ethylbenzene. The mixture in the vessel was maintained at 80.degree. C. 
for 15 minutes with stirring, then incorporated with 300 ml of methanol, 
heated to 110.degree. C. with stirring, and maintained thereat for 30 
minutes, followed by cooling, filtering and vacuum drying. The polymer 
thus obtained as the sample was injection molded, and the resultant 
molding was tested to measure the amount of residual metal components and 
YI. The results are given in Tabel 1. 
Example 3 
The procedure in Example 1 was repeated except that ferrocenium 
tetra(pentafluorophenyl)borate and ethanol were employed in place of 
N,N-dimethylanilinium tetra(pentafluorophenyl)borate and methanol, 
respectively. The results obtained are given in Table 1. 
Example 4 
The procedure in Example 1 was repeated except that triphenylcarbenium 
tetra(pentafluorophenyl)borate was employed in place of 
N,N-dimethyl-anilinium tetra(pentafluorophenyl)borate and the 
polymerization reaction was carried out for 4.5 hours. The results 
obtained are given in Table 1. 
Example 5 
The procedure in Example 1 was repeated except that 480 ml of ethylbenzene 
and 120 ml of methanol were employed and the treatment temperature was set 
at 100.degree. C. The results obtained are given in Table 1. 
Example 5 
The procedure in Example 1 was repeated except that n-propanol was employed 
in place of methanol. The results obtained are given in Table 1. 
Comparative Example 1 
The polymer as obtained in Example 1 was vacuum dried as such. The results 
obtained are given in Table 1. 
Comparative Example 2 
The procedure in Example 1 was repeated except that 600 ml of ethylbenzene 
was employed in place of methanol and the treatment temperature was set at 
90.degree. C. The results obtained are given in Table 1. 
Comparative Example 3 
The procedure in Example 1 was repeated except that 600 ml of methanol was 
employed without the use of ethylbenzene and the treatment temperature was 
set at 100.degree. C. The results obtained are given in Table 1. 
Comparative Example 4 
The procedure in Example 4 was repeated except that the treatment 
temperature was set at 120.degree. C. When the treating liquid was cooled, 
the whole solution was solidified and thereby the subsequent treatment was 
made impossible. The results obtained are given in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Degree of 
Amount of residual metal 
Degree of 
swelling 
components (ppm by weight) 
deashing 
(% by voluem) 
before treatment 
after treatment 
(DE value) 
YI.sup.*2 
__________________________________________________________________________ 
Example 1 
25 260 45 0.83 14 
Example 2 
25 260 54 0.79 15 
Example 3 
25 260 48 0.82 15 
Example 4 
25 250 50 0.80 15 
Example 5 
22 260 55 0.79 16 
Example 6 
26 260 52 0.80 16 
Comparative 
- - 260 - 30 
Example 1 
Comparative 
27 260 250 0.03 28 
Example 2 
Comparative 
-4 260 255 0.02 20 
Example 3 
Comparative 
&gt;35 -- *3 -- -- 
Example 4 
__________________________________________________________________________ 
.sup.*1 Degree of deashing (DE value) obtained by the following formula 
DE = 1(amount of residual metal components in ppm by weight after 
treatment/amount of residual metal components in ppm by weight before 
treatment) 
.sup.*2 Yellowness Index: according to JIS K7103 
.sup.*3 Unmeasurable because part of sample was dissolved and whole 
solution was solidified.