Styrene copolymer and process for production thereof

A novel styrene copolymer comprising a styrene repeating unit (a) represented by the general formula: ##STR1## (wherein R.sup.1 is a hydrogen atom or a hydrocarbon group having not more than 20 carbon atoms; n is an integer of 1 to 3 and when n is 2 or 3, R.sup.1 s may be the same or different) and olefin repeating unit (b) represented by the general formula: ##STR2## (wherein R.sup.2 is a hydrogen atom or a saturated hydrocarbon group having not more than 20 carbon atoms) or diene repeating unit, which contains 0.1 to 99.9 wt. % of said olefin repeating unit (b) or diene repeating unit (c) wherein intrinsic viscosity measured in 1,2,4-trichlorobenzene at 135.degree. C. is 0.07 to 20 dl/g and the stereoregularity of the styrene repeating unit chain is a high degree of syndiotactic configuration. This styrene copolymer is excellent in heat resistance and chemical resistance, and further it can be injection molded at low temperature, and has good compatibility with other resine and the like.

FIELD OF THE INVENTION 
The present invention relates to styrene copolymer and process for 
production thereof, more specifically it relates to copolymer having a 
specific stereostructure which comprises a styrene monomer and olefin 
monomer or diene monomer, and to an efficient process for production 
thereof. 
BACKGROUND OF THE INVENTION 
A styrene polymer produced by the radical polymerization method, etc. has 
an atactic configuration in stereostructure. It is molded into various 
shapes by various molding methods such as injection molding, extrusion 
molding, blow molding, vacuum molding and cast molding, and is widely used 
for domestic electric appliances, office equipments, domestic appliances, 
packaging containers, toys, furniture, synthetic papers and other 
industrial materials. 
However, the styrene polymer having an atactic configuration has drawbacks 
of insufficient heat resistance and chemical resistances. 
The group of the present inventors have succeeded to develop a styrene 
polymer having a high degree of syndiotacticity, and also developed a 
styrene polymer in which other components are copolymerized with the 
styrene monomer (Japanese Patent Application Laid-Open Nos. 104818/1987 
and 241009/1989). Such polymer or copolymer having a syndiotactic 
configuration has excellent heat resistance, chemical resistance and 
electric characteristic, and expected to be applied in various fields. 
However, in the above polymer, particularly, syndiotactic polystyrene, 
glass transition temperature is high, i.e., 90.degree. to 100.degree. C., 
and melting point is 270.degree. C. Accordingly, the polymer has defects 
that it cannot sufficiently show its characteristics unless injection 
molding temperature is set at high temperature. In addition, the molded 
product obtained by using a high temperature mold is required to be 
improved in impact resistance. The above polymer has disadvantages in that 
it has poor compatibility with polyolefins such as polyethylene, 
polypropylene and the like. Such polymer has insufficient compatibility 
and adhesion with other resin, inorganic fillers or the like. 
Particularly, compared with olefin polymer which is characterized in its 
flexibility, the syndiotactic polystyrene should be improved in its 
solvent resistance, heat resistance and impact resistance. 
Accordingly, the present inventors have studied intensively to decrease the 
glass transition temperature of syndiotactic polystyrene to enable 
injection molding at low temperature and further to improve impact 
resistance and compatibility and adhesion with other resins including 
polyolefin and inorganic fillers. 
As the results, it has been found that copolymerization of styrene monomer 
and olefin monomer or diene monomer in the presence of a specific catalyst 
provides a copolymer having styrene repeating unit chain with syndiotactic 
configuration copolymerized with olefin component or diene component. Such 
copolymer has excellent heat resistance and chemical resistance. Further, 
it can be injection molded at low temperature because of its reduced glass 
transition temperature. Moreover, it has good compatibility with other 
resins. Thus it has been found that the objective modification can be 
attained.. The present invention has been established based on such 
findings. 
SUMMARY OF THE INVENTION 
The present invention provides styrene copolymer which comprises a styrene 
repeating unit (a) represented by the general formula (I): 
##STR3## 
(wherein R.sup.1 is a hydrogen atom, a halogen atom or a hydrocarbon group 
having not more than 20 carbon atoms, n is an integer of 1 to 3, and when 
n is plural, R.sup.1 s may be the same or different) 
and an olefin repeating unit (b) represented by the general formula (II): 
##STR4## 
(wherein R.sup.2 is a hydrogen atom or a saturated hydrocarbon group 
having not more than 20 carbon atoms) 
or a diene repeating unit (c), which contains 0.1 to 99.9% (by weight) of 
an olefin repeating unit (b) or a diene repeating unit (c), wherein 
intrinsic viscosity (measured in 1,2,4-trichlorobenzene at 135.degree. C.) 
is 0.07 to 20 dl/g and the stereostructure of the styrene repeating unit 
chain is high degree of syndiotactic configuration. 
Further, the present invention provides a process for producing the above 
styrene copolymer which comprises copolymerizing a styrene monomer 
represented by the general formula (I'): 
##STR5## 
(wherein R.sup.1 and n are the same as defined above) and an olefin 
monomer represented by the general formula (II'): 
##STR6## 
(wherein R.sup.2 is the same as defined above) or diene monomer in the 
presence of a catalyst comprising a transition metal compound and 
alkylaluminoxane.

BEST MODE TO CONDUCT THE INVENTION 
The styrene copolymer of the present invention comprises, as mentioned 
above, a styrene repeating unit (a) represented by the general formula (I) 
and an olefin repeating unit (b) represented by the general formula (II) 
or a diene repeating unit (c), wherein the repeating unit represented by 
the general formula (I) is derived from the styrene monomer represented by 
the above general formula (I'). In the formula, R.sup.1 is a hydrogen 
atom, a halogen atom (for example, chlorine, bromine, fluorine, iodine) or 
a hydrocarbon group having not more than 20 carbon atoms, preferably, 10 
to 1 carbon atoms (for example, a saturated hydrocarbon group 
(particularly an alkyl group) such as methyl, ethyl, propyl, butyl, 
pentyl, hexyl or a unsaturated hydrocarbon group such as vinyl). The 
repeating unit represented by the general formula (I) includes an 
alkylstyrene unit such as a styrene unit, p-methylstyrene unit, 
m-methylstyrene unit, o-methylstyrene unit, 2,4-dimethylstyrene unit, 
2,5-dimethylrstyrene unit, 3,4-dimethylstyrene unit, 3,5-dimethylstyrene 
unit, p-ethylstyrene unit, m-ethylstyrene, p-tert-butylstyrene unit; a 
divinyl benzene unit such as p-divinylbenzene unit, m-divinylbenzene unit, 
trivinylbenzene unit; a halogenated styrene unit such as p-chlorostyrene 
unit, m-chlorostyrene unit, o-chlorostyrene unit, p-bromostyrene unit, 
m-bromostyrene unit, o-bromostyrene unit, p-fluorostyrene unit, 
m-fluorostyrene unit, o-fluorostyrene unit, o-methyl-p-fluorostyrene unit; 
or a mixture of two or more of them. 
On the other hand, the olefin repeating unit (b) represented by the general 
formula (II) is derived from the olefin monomer represented by the above 
general formula (II'). In the formula, R.sup.2 is a hydrogen atom or 
olefins having not more than 20 carbon atoms, preferably a hydrogen atom 
or olefins having 10 to I carbon atoms, for example, an olefin such as 
ethylene, propylene, 1-butene, 1-pentene, 3-methyl-butene-1, 1-hexene, 
3-methyl-pentene-1, 4-methylpentene-1, 1-octene, 1-decene or the like may 
be used. Among them, ethylene, propylene, 1-butene, 1-hexene or a mixture 
thereof may be preferred. More preferably, ethylene, propylene or a 
mixture thereof. 
The diene repeating unit (c) is derived from various kinds of diene 
monomers. The diene monomers herein used are not particularly limited, and 
they are roughly divided into conjugated straight chain diene monomer, 
unconjugated straight chain diene monomer, conjugated cyclic diene monomer 
and unconjugated cyclic diene monomer. Among them, conjugated straight 
chain diene monomer includes compounds represented by the general formula: 
##STR7## 
(wherein R.sup.a and R.sup.b each are a hydrogen atom, an alkyl group, an 
aryl group or a halogen atom, R.sup.c is a hydrogen atom or a saturated 
hydrocarbon group having not more than 6 carbon atoms), for example, 
1,3-butadiene or alkyl-substituted butadienes such as isoprene, 
1,3-pentadiene; aryl-substituted butadienes such as 1- or 
2-aryl-1,3-butadiene, 1- or 2-phenyl-1,3-butadiene, 
2-phenyl-3-methyl-1,3-butadiene; halo-substituted butadiene such as 
2-chloro-1,3-butadiene, 2-fluoro-1,3-butadiene. Unconjugated straight 
chain diene monomer includes 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene. 
Conjugated cyclic diene monomer includes, for example, 1,3-cyclohexadiene, 
1,3-cyclooctadiene. 
Unconjugated cyclic diene monomer includes, for example, norbornadiene, 
1,5-cyclooctadiene, 5-vinylnorbornene and the like. 
Among them, unconjugated straight chain diene monomer and unconjugated 
cyclic diene monomer are desirably used. 
In the copolymer of the present invention, diene repeating unit (c) is 
composed of the above diene monomers which are polymerized, and when said 
diene repeating unit (c) consists of the conjugated straight chain diene 
monomers of the above general formula (III), it is classified into 
1,2-polymerized type represented by the general formula: 
##STR8## 
and 1,4-polymerized type represented by the general formula: 
##STR9## 
By polymerization, 1,2-polymerized type provides diene repeating units 
having any one of syndiotactic configuration, isotactic configuration, 
atactic configuration and a mixture thereof, and 1,4-polymerized type 
provides diene repeating units having cis- or trans-configuration. 
Polymerization of unconjugated cyclic monomer provides diene repeating 
units having trans annular configuration. In the present invention, 
however, diene repeating unit (c) with any configuration may be 
sufficiently used so long as it gives no effect on syndiotacticity of the 
styrene chain. 
In the copolymer of the present invention, the styrene repeating unit (a) 
may be composed of two or more components, which applies to olefin 
repeating unit (b) or diene repeating unit (c). Thus, bi-, ter-, or tetra- 
copolymer can be synthesized. The content of the above olefin repeating 
unit (b) or diene repeating unit (c) is generally 0.1 to 99.9 wt. %, 
preferably 1 to 99 wt. %, more preferably 5 to 95 wt. % of the copolymer. 
When the content of the olefin repeating unit (b) or the diene repeating 
unit (c) is less than 0.1 wt. %, the objective improvement of the present 
invention such as decrease of glass transition temperature or improvement 
of impact resistance can not be sufficiently attained. On the other hand, 
when it is over 99.9 wt. %, the characteristic of the styrene polymer 
having syndiotactic configuration, that is, heat resistance may not be 
developed. 
As for the molecular weight of this copolymer, intrinsic viscosity measured 
in 1,2,4-trichlorobenzene solution (135.degree. C.) is generally 0.07 to 
20 dl/g, preferably, 0.3 to 10 dl/g. When intrinsic viscosity is less than 
0.07 dl/g, the copolymer can not be put into practical use because of its 
poor dynamic properties. Those having intrinsic viscosity of over 20 dl/g 
are not suitable for the conventional melt molding. 
In the present invention, the third component can be added so long as it 
cannot markedly degrade the properties of the resulting copolymers or the 
syndiotactic configuration of the styrene repeating unit (a) chain. Such 
third component includes dienes, vinylsiloxanes, unsaturated carboxylic 
acid esters, acrylonitriles for copolymers consisting of styrene repeating 
unit (a) and olefin repeating unit (b); and vinylsiloxanes, 
.alpha.-olefins, unsaturated carboxylic acid esters, acrylonitriles, 
N-substituted maleimides for copolymers consisting of styrene repeating 
unit (a) and diene repeating unit (c). 
The styrene copolymer of the present invention has a styrene repeating unit 
(a) chain having a high degree of syndiotactic configuration. Here, a high 
degree of syndiotactic configuration in the styrene polymers means that 
stereochemical structure is a high degree of syndiotactic configuration, 
that is, the stereostructure in which phenyl groups or substituted phenyl 
groups as side chains are located alternately in 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 measured 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. In the styrene 
copolymer having a high degree of syndiotactic configuration in the 
present invention, the proportion of racemic diad is at least 75%, 
preferably at least 85%, or proportions of racemic pentad is at least 30% 
and preferably at least 50%. However, the degree of syndiotacticity may 
somewhat vary depending on the types of the substituent or content of the 
olefin repeating unit (b) or diene repeating unit (c). 
The copolymer of the present invention described above with the desired 
configuration and reactive substituents can be produced by 
copolymerization of the monomers corresponding to the repeating units (a), 
(b) and (c), and fractionation, blend or application of other technique of 
organic synthesis using the resulting copolymer as a starting material. 
Among them, the above-described process of the present invention more 
efficiently provides the styrene copolymer of high quality. 
The starting monomer used in the process for production of the present 
invention is styrene monomer represented by the general formula (I') and 
olefin monomer represented by the general formula (II') or diene monomer. 
The styrene monomer and olefin monomer or diene monomer are copolymerized 
to constitute the corresponding repeating units. Accordingly, examples of 
the styrene monomer, olefin monomer or diene monomer include the compounds 
corresponding to the examples described for the above styrene repeating 
unit (a), olefin repeating unit (b) and diene repeating unit (c). 
In the process of the present invention, these styrene monomers and olefin 
monomers or diene monomers are used as starting materials and 
copolymerized in the presence of a catalyst which contains transition 
metal compound (A) and aluminoxane (B) as main components. 
In this case, component (A), i.e., the transition metal compound includes 
various compounds, preferably at least one compound selected from 
transition metal compounds represented by the general formula: 
##STR10## 
(wherein R.sup.3 to R.sup.14 each are a hydrogen atom, a halogen 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 arylalkyl 
group having 7 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon 
atoms, an acyloxy group having 1 to 20 carbon atoms, an acetylacetonyl 
group, a cyclopentadienyl group, a substituted cyclopentadienyl group or 
an indenyl group, and a, b and c represent integers (not less than 0) of 
0.ltoreq.a+b+c.ltoreq.4, d and e indicate integers (not less than 0) of 
0.ltoreq.d+e.ltoreq.3 f is an integer of 0.ltoreq.f.ltoreq.2, h and k are 
integers (not less than 0) of 0.ltoreq.h+k.ltoreq.3, M.sup.1 and M.sup.2 
are titanium, zirconium, hafnium, or vanadium, M.sup.3 and M.sup.4 
indicate vanadium). Among these transition metal compounds, those 
represented by the above general formula (.alpha.) wherein M.sup.1 is 
titanium or zirconium are preferably used. 
Those represented by R.sup.3 to R.sup.14 in the above formula include 
halogen, for example, chlorine, bromine, iodine or fluorine. Substituted 
cyclopentadienyl group includes cyclopentadienyl group which is 
substituted by at least one alkly group having 1 to 6 carbon atoms, for 
example, methylcyclopentadienyl, 1,2-dimethylcyclopentadienyl, 
1,3-dimethylcyclopentadienyl, 1,3,4-trimethylcyclopentadienyl, and 
pentamethylcyclopentedienyl. 
R.sup.3 to R.sup.14 in the above formula independently represent a hydrogen 
atom, an alkyl group having 1 to 20 carbon atoms (e.g., methyl, ethyl, 
propyl, n-butyl, isobutyl, amyl, isoamyl, octyl, 2-ethylhexyl), an alkoxy 
group having 1 to 20 carbon atoms (e.g., methoxy, ethoxy, propoxy, butoxy, 
hexyloxy, octyloxy, 2-ethylhexyloxy), an aryl group having 6 to 20 carbon 
atoms (e.g., phenyl, naphthyl), an arylalkyl group having 7 to 20 carbon 
atoms (e.g., benzyl, phenetyl, 9-anthrylmethyl), an acyloxy group having 1 
to 20 carbon atoms (e.g., acetyloxy, stearoyloxy). These R.sup.3 to 
R.sup.14 may be the same or different so long as they satisfy the above 
requirements. They may be monodentate ligands, or ligands may bond to each 
other to give multidentate ligand. 
The more preferable example is a titanium compound represented by the 
general formula: 
EQU TiRXYZ (.xi.) 
(wherein R is a cyclopentadienyl group, a substituted cyclopentadienyl 
group or an indenyl group, and X, Y and Z are independently a hydrogen 
atom, an alkly 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 6 to 20 
carbon atoms or a halogen atom). The substituted cyclopentadienyl group 
represented by R in the above formula is a cyclopentadienyl group 
substituted by one or more alkyl groups having 1 to 6 carbon atoms, 
specifically a methylcyclopentadienyl group, a 
1,2-dimethylcyclopentadienyl group, a 1,3-dimetylcyclopentadienyl group, a 
1,3,4-trimethylcyclopentadienyl group, a pentamethylcyclopentadienyl group 
or the like. X, Y and Z are independently a hydrogen atom, an alkyl group 
having 1 to 12 carbon atoms (specifically, methyl, ethyl, propyl, n-butyl, 
isobutyl, amyl, isoamyl, octyl, 2-ethylhexyl group, etc.), an alkoxy group 
having 1 to 12 carbon atoms (specifically, methoxy, ethoxy, propoxy, 
butoxy, amyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, etc.), an aryl group 
having 6 to 20 carbon atoms (specifically, phenyl, naphthyl, etc.), an 
aryloxy group having 6 to 20 carbon atoms (specifically, phenoxy, etc.), 
an arylalkyl group having 6 to 20 carbon atoms (specifically, benzyl, 
etc.), or a halogen atom (specifically, chlorine, bromine, iodine or 
fluorine). 
Specific examples-of the titanium compound represented by the general 
formula (.xi.) are cyclopentadienyltitanium trimethyl, 
cyclopentadienyltitanium triethyl, cyclopentadienyltitanium tripropyl, 
cyclopentadienyltitanium tributyl, mentylcyclopentadienyltitanium 
trimethyl, 1,2-dimethylcyclopentadienyltitanium trimehtyl, 
pentamethylcyclopentadienyltitanium trimethyl, 
pentamethylcyclopentadienyltitanium triethyl, 
pentamethylcyclopentadienyltitanium tripropyl, 
pentamethylcyclopentadienyltitanium tributyl, cyclopentadienyltitanium 
methyldichloride, cyclopentadienyltitanium ethyldichloride, 
pentamethylcyclopentadienyltitanium methyldichloride, 
pentamethylcyclopentadienyltitanium ethyldichloride, 
cyclopentadienyltitanium dimethylmonochloride, cyclopentadienyltitanium 
diethylmonochloride, cyclopentadienyltitanium trimethoxide, 
cyclopentadienyltitanium triethoxide, cyclopentadienyltitanium 
tripropoxide, cyclopentadienyltitanium triphenoxide, 
pentamethylcyclopentadienyltitanium trimethoxide, 
pentamethylcyclopentadienyltitanium triethoxide, 
pentamethylcyclopentadienyltitaniuin tripropoxide, 
pentamethylcyclopentadienyltitanium tributoxide, 
pentamethylcyclopentadienyltitanium triplienoxide, 
cyclopentadienyltitanium trichloride, pentamethylcyclopentadienyltitanium 
trichloride, cyclopentadienyltitanium methoxydichloride, 
cyclopentadienyltitanium dimethoxychloride, 
pentamethylcyclopentadienyltitanium methoxydichloride, 
cyclopentadienyltitanium tribenzyl, 
pentamethylcyclopentadienylmethyltitanium diethoxy, indenyltitanium 
trichloride, indenyltitanium trimethoxide, indenyltitanium triethoxide, 
indenyltitanium trimethyl, indenyltitanium tribenzyl and the like. 
As the component (B) constituting the main component of the catalyst in 
combination with the above titanium compound component (A), 
alkylaluminoxane is used. For example, alkylaluminoxane represented by the 
general formula: 
##STR11## 
(wherein R.sup.15 is an alkyl group having 1 to 8 carbon atoms, and r is a 
number of 2 to 50). These alkylaluminoxanes can be prepared by various 
methods. For example, (1) the method in which alkylaluminum is dissolved 
in an organic solvent and the resulting solution is contacted with water, 
(2) the method in which alkylaluminum is first added at the time of 
polymerization, and then water is added thereto, and (3) the method in 
which water of crystallization contained in a metal salt and the like, or 
water adsorbed in an inorganic material or an organic material is reacted 
with alkylaluminum. The above water may contain ammonia, amine such as 
ethylamine and the like, a sulfur compound such as hydrogen sulfide and 
the like and a phosphorus compound such as phosphite and the like in an 
amount up to 20%. 
Suitable examples of alkylaluminoxane used as the component (B) are 
methylaluminoxane 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 magnetic resonance 
method is not more than 50%. That is, in a proton nuclear magnetic 
resonance (.sup.1 H--NMR) spectral analysis of the above contact product 
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 region in which the methyl proton due to Al--CH.sub.3 is 
observed, this methyl proton signal due to Al--CH.sub.3 is measured based 
on the methyl proton signal of toluene (2.35 ppm) based on TMS standard, 
and when divided into the high magnetic field components (i.e. -0.1 to 
-0.5 ppm) and other magnetic field components (i.e. 1.0 to -0.1 ppm), 
alkylaluminoxane in which high magnetic field component is not more than 
50%, preferably 45 to 5% of the total signal area is used as the component 
(B) of the catalyst of the method of the present invention. 
The catalyst to be used in the process of the present invention contains 
the above components (A) and (B) as main components. If desired, other 
catalyst components, for example, trialkylaluminum represented by the 
general formula: 
EQU AlR.sup.16.sub.3 
(wherein R.sup.16 is an alkyl group having 1 to 8 carbon atoms), or other 
organometallic compounds can be added. Further, organic compounds 
represented by the general formula: 
EQU W--R.sup.17 --(Q).sub.m P--R.sup.18 --W' (.theta.) 
(wherein R.sup.17 and R.sup.18 are a hydrocarbon group having 1 to 20 
carbon atoms, a substituted aromatic hydrocarbon group having 7 to 30 
carbon atoms or a substituted aromatic hydrocarbon group having 
substituents containing hetero atoms such as oxygen, nitrogen, sulfur and 
the like and having 6 to 40 carbon atoms, Q is a hydrocarbon group having 
1 to 20 carbon atoms, 
##STR12## 
(wherein R.sup.19 is a hydrocarbon group having 1 to 6 carbon atom), W and 
W' are a hydroxyl group, an aldehyde group, a carboxyl group, and m is an 
integer of 0 to 5), can be added so long as the stereoregularity is not 
damaged. The examples of the organic compound represented by the general 
formula (.theta.) include, for example, 
2,2'-dihydroxy-3,3'-di-t-butyl-5,5'-dimethyldiphenylsulfide, 
2,2'-dihydroxy-3,3'-di-t-butyl-5,5'-dimethyldiphenylether and the like. 
The ratio of the component (A) to the component (B) in the catalyst varies 
with the type of each catalyst component, the type of each styrene monomer 
represented by the general formula (I') and olefin monomer represented by 
the general formula (II') or diene monomer as the starting materials, and 
other conditions, and thus cannot be determined unconditionally. Usually, 
the ratio of aluminum contained in component (B) to titanium contained in 
component (A), i.e. aluminum/titanium (molar ratio) is 1 to 10.sup.6, 
preferably 10 to 10.sup.4. 
In accordance with the process of the present invention, the styrene 
monomers represented by the above general formula (I') and olefin monomers 
represented by the general formula (II') or diene monomers are 
copolymerized in the presence of a catalyst containing components (A) and 
(B) as the main components. This copolymerization may be carried out in 
various methods such as bulk copolymerization, solution copolymerization 
or suspension copolymerization. Solvents which may be used for 
copolymerization include aliphatic hydrocarbons such as pentane, hexane, 
heptane, decane and the like, alicyclic hydrocarbons such as cyclohexane 
and the like, or aromatic hydrocarbons such as benzene, toluene, xylene 
and the like. The polymerization temperature is not particularly limited, 
but generally, 0.degree. to 100.degree. C., preferably, 10.degree. to 
70.degree. C. The polymerization period of time is 5 minutes to 24 hours, 
preferably not less than one hour. Further, it is effective to conduct 
copolymerization in the presence of hydrogen to control the molecular 
weight of the resulting styrene copolymers. 
The styrene copolymers obtained by the process of the present invention 
have a high degree of syndiotacticity of the styrene repeating unit chain. 
After polymerization, the copolymers may be delimed with a washing 
solution containing hydrochloric acid or the like, if necessary, and after 
washing, drying under reduced pressure, the solubles may be removed by 
washing with a solvent such as methyl ethyl ketone or the like to obtain 
styrene copolymer of high purity having an extremely high degree of 
syndiotacticity. 
The present invention will be described in more detail with reference to 
examples. 
EXAMPLE 1 
(1) Preparation of Methylaluminoxane 
In a 500-milliliter glass vessel which had been purged with argon were 
placed 200 ml of toluene, 17.8 g (71 mmol) of copper sulfate pentahydrate 
(CuSO.sub.4.5H.sub.2 O) and 24 ml (250 mmol) of trimethylaluminum, which 
were then reacted at 40.degree. C. for 8 hours. Then, solids were 
separated from the reaction mixture, and the toluene was distilled away 
from the solution as obtained above under reduced pressure at room 
temperature to obtain 6.7 grams of a contact product (methylaluminoxane). 
The molecular weight of the contact product as determined by the freezing 
point depression method was 610. As for the high magnetic field component 
as determined by the above .sup.1 H-NMR method, methyl proton signal due 
to (Al--CH.sub.3) bond as observed by the proton nuclear magnetic 
resonance spectrum in a toluene solution at room temperature was found in 
the region from 1.0 to -0.5 ppm (tetramethylsilane standard). Since the 
proton signal-of tetramethylsilane (0 ppm) was found in the observation 
region due to methyl proton due to (Al--CH.sub.3) bond, this methyl proton 
signal due to (Al--CH.sub.3) bond was determined based on the methyl 
proton signal of toluene (2.35 ppm) (tetramethylsilane standard) and 
divided into high magnetic field component (i.e., -0.1 to -0.5 ppm) and 
other magnetic field component (i.e., 1.0 to -0.1 ppm). The high magnetic 
field component was 43%. 
(2) Production of Styrene-Ethylene Copolymer 
In a 1.0 liter reactor equipped with a stirrer were placed 20 ml of 
toluene, 180 ml of styrene and 10.0 mmol as aluminum atom of 
methylaluminoxane obtained in (1) above, and stirred at the polymerization 
temperature of 70.degree. C. for 30 minutes. Then, 0.05 mmol as titanium 
atom of pentamethylcyclopendadienyltitanium trimethoxide was added. 
Further, ethylene monomer was introduced in the reactor through an 
exclusive line, the pressure in the reactor was increased to 8.0 
kg/cm.sup.2 G. Subsequently, polymerization was performed at 70.degree. C. 
for 4 hours. After the polymerization, the unreacted gas was removed, 
methanol was poured to cease the reaction. Further, a mixture of methanol 
and hydrochloric acid was added to decompose the catalyst components. The 
yield of thus obtained styrene-ethylene copolymer was 12.2 g. Intrinsic 
viscosity measured in 1,2,4-trichlorobenzene solution at 135.degree. C. 
was 1.30 dl/g. 
The fact that the styrene chain of this styrene-ethylene copolymer has 
syndiotactic configuration was confirmed by the results of differential 
scanning caloriemeter (DSC) and the nuclear magnetic resonance spectrum 
using carbon isotope (.sup.13 C-NMR). 
(a) Determination by DSC 
After the styrene copolymer obtained in Example 1 was sufficiently dried, 
then 10 mg portion was charged in a vessel for DSC. The temperature was 
increased from 50.degree. C. to 300.degree. C. at a rate of 20.degree. 
C./min, then kept at 300.degree. C. for 5 minutes, and decreased from 
300.degree. C. to 50.degree. C. at a rate of 20.degree. C./min. This 
sample was heated again from 50.degree. C. to 300.degree. C. at a rate of 
20.degree. C./min, and the endo- and exothermic pattern was observed. The 
apparatus used was DSC-II manufactured by Perkin-Elmer. 
As the result, the glass transition temperature and the melt temperature of 
this copolymer was 80.degree. C. and 262.degree. C., respectively. 
The facts that the conventional atactic polystyrenes have no melt 
temperature, the melt temperature of isotactic polystyrene is 230.degree. 
C. and the melt temperature of the copolymer never exceeds the higher melt 
temperature of the homopolymers shows that the styrene chain of this 
copolymer has syndiotactic configuration and the copolymer is crystalline 
substance. 
On the other hand, the glass transition temperature and melt temperature of 
ethylene homopolymer, which were determined for reference, were 
-90.degree. C. and 126.degree. C., respectively. The glass transition 
temperature of syndiotactic polystyrene was 96.degree. C. 
Accordingly, the glass transition temperature of the resulting copolymer 
was between those of each homopolymers, and it is supposed to be a 
copolymer. 
(b) Determination by .sup.13 C-NMR 
The above styrene copolymer was analyzed in 1,2,4-trichlorobenzene solution 
at 135.degree. C. As the result, the aromatic signals were observed at 
145.1 ppm and 145.9 ppm. Accordingly, the styrene chain was confirmed to 
have syndiotactic configuration. Further, it has a signal at 29.5 ppm due 
to ethylene chain. The content of the ethylene chain in the copolymer was 
4.0 wt. %. The apparatus used was FX-200 manufactured by Nippon Denshi 
Co. 
(c) Morphology of the molded products 
The copolymers were injection molded at melt temperature of 300.degree. C. 
and at mold temperature of 100.degree. C. The cross section of the 
injection molded product was observed. As the result, it showed good 
dispersion state with very small domains dispersed therein, which can not 
be observed in the general incompatible mixture. Izod impact strength of 
the molded product was measured according to JIS-K7110. 
The scanning electron micrograph (SEM) of the copolymers obtained above is 
shown in FIG. 1. FIG. 1 shows that both styrene and ethylene structural 
units are highly dispersed. 
These facts show that the copolymer is a crystalline styrene-ethylene 
copolymer which contains styrene chain having syndiotactic configuration. 
EXAMPLES 2 TO 7 AND COMATIVE EXAMPLES 1 AND 2 
The procedure of Example 1 was repeated using starting materials, catalysts 
and polymerization conditions shown in Table 1, to obtain styrene-ethylene 
copolymers. The characteristics of the resulting copolymers as well as the 
result of Example 1 are shown in Table 1. 
The copolymer samples obtained in Examples 3 to 5, and, as comparative 
samples, syndiotactic polystyrene (SPS) sample, polyethylene (HDPE) sample 
and a blend sample which was prepared by completely dissolving 20 wt. % of 
syndiotactic polystyrene and 80 wt. % of polyethylene in 
1,2,4-trichlorobenzene at 180.degree. C., precipitating in methanol 
(tightly interblended state) were prepared by press molding to be used as 
test samples for measurement of dynamic viscoelasticity. Subsequently, 
these six samples of four types were measured for dynamic viscoelasticity 
using Rheovibron DDV-II-EA type apparatus (frequency, 110 Hz; Linear Rise, 
2.0) manufactured by Orientek Co. The results are shown in FIG. 2. In the 
figure, the ordinate shows a range of the measuring temperature (.degree. 
C.), the abscissa shows storage elastic modulus (E) (dyne/cm.sup.2). The 
results of the measurement of the samples of Examples 3 to 5 show that the 
value (E) thereof decreased in the range from lower temperature to 
95.degree. to 96.degree. C. which corresponds to glass transition 
temperature of syndiotactic polystyrene, as compared with an artificial 
tightly interblended syndiotactic polystyrene and polyethylene. Thus, 
flexibility is supposed to be imparted to the above copolymer. 
Originally, syndiotactic polystyrene and polyethylene are incompatible. 
Therefore, the operation to induce tightly interblended state results in 
phase separation and exfoliation during injection molding so long as it is 
a blend. The copolymer according to the present invention, however, has 
highly dispersed structure as shown in FIG. 1, exfoliation during molding 
is prevented and, as is obvious from the measurement of dynamic 
viscoelasticity, the molded products provided with flexibility can be more 
readily obtained compared with syndiotactic polystyrene. 
EXAMPLES 8 AND 9 
In the same manner as that of the process for production of 
styrene-ethylene copolymer in the above Example 1, 
p-methylstyrene-ethylene copolymer was produced. The results are shown in 
Table 1. 
The resulting p-methylstyrene-ethylene copolymer was extracted with 
methylethylketone or the like, and the DSC analysis for the extraction 
residue was carried out under the same conditions as those in Example 1 to 
find only melting point due to ethylene skeleton (121.degree. to 
122.degree. C.). However, the extraction residue was analyzed by .sup.13 
C-NMR using, 1,2,4-trichlorobenzene as a solvent. As the result, pointed 
singlet peak was observed at 142.3 to 142.5 ppm. This result is identical 
to that described in Japanese Patent Application Laid-Open No. 187708/1987 
and suggests that p-methylstyrene unit has syndiotactic configuration. 
Further, peaks due to ethylene skeleton were observed at 29.4 to 29.6 ppm 
as Example 1, which shows that the product is a copolymer. 
The above results show that the copolymer is a crystalline 
p-methylstyrene-ethylene copolymer with syndiotactic configuration 
containing p-methylstyrene chain. 
EXAMPLE 10 
In a 1.0-liter reactor equipped with a stirrer which had been purged with 
argon were placed 400 ml of toluene, 2.5 ml (5.0 mmol) of tri-isobutyl 
aluminum and 5.0 mmol as aluminum atom of methylaluminoxane obtained in 
the above Example 1 and 50.0 .mu.mol as titanium atom of 
pentamethylcyclopentadienyltitanium trimethoxide, and the resultant was 
maintained at 50.degree. C. 
Subsequently, propylene monomer was introduced into the reactor through an 
exclusive line, the content of the reactor was sufficiently replaced with 
propylene monomer, then pressure in the reactor was increased to 4.5 
kg/cm.sup.2 G. 
Then, an exclusive line for propylene monomer is blocked while the pressure 
in the reactor was maintained at 4.5 kg/cm.sup.2 G, and ethylene monomer 
was introduced into the reactor through an exclusive line and the pressure 
was increased to 9.0 kg/cm.sup.2 G. 
The resultant was stirred at the polymerization temperature of 50.degree. 
C. for 20 minutes, then 70 ml of styrene monomer was introduced through an 
exclusive line. Then, polymerization was carried out at 50.degree. C. for 
4 hours with stirring. After the polymerization, the unreacted gas was 
removed, a mixture of methanol and hydrochloric acid was poured to 
decompose the catalytic components. 
The yield of thus obtained styrene polymer was 4.32 grams. For separation 
of atactic polystyrene from the resulting styrene polymer, the polymer was 
washed for 8 hours using Soxhlet extractor and methlylethylketone as a 
solvent. 
Further, for separation of ethylene-propylene copolymer, washing was 
carried out for 8 hours using n-heptane as a solvent. The composition of 
thus extracted ethylene-propylene copolymer calculated from .sup.1 H-NMR 
was 53.7 mol. % of ethylene unit and 46.3 mol. % of propylene unit. 
Melting point was 100.degree. C. 
Further, for separation of polyethylene from the polymer which is insoluble 
in methylethylketone and n-heptane, extraction was carried out for 8 hours 
using methylene chloride as a solvent. As the result, the objective 
styrene polymer, that i.e., polymer soluble in methylene chloride was 25.4 
wt. %. 
The yield of styrene polymer soluble in methylene chloride after separation 
of atactic polystyrene, ethylene-propylene copolymer and polyethylene was 
0.55 gram, and intrinsic viscosity measured in 1,2,4-trichlorobenzene at 
135.degree. C. was 2.06 dl/g. 
According to the result of measurement of infrared absorption spectrum, 
absorptions due to ethylene, propylene structure were found at 720, 1,150 
and 1,378 cm.sup.-1. The composition calculated from .sup.1 H-NMR spectrum 
was 67.8 mol. % of styrene unit, 16.7 mol. % of ethylene unit and 15.4 
mol. % of propylene unit. 
The composition of ethylene-propylene component contained therein was 
within the composition range of ethylene-propylene copolymer soluble in 
n-heptane, thus it was confirmed that ethylene-propylene copolymer does 
not exist in the polymer. 
Further, according to the analysis by .sup.13 C-NMR spectrum 
(1,2,4-trichlorobenzene as a solvent), absorption due to syndiotactic 
configuration of styrene chain was found at 145.15 ppm. Syndiotacticity in 
racemic pentad calculated from peak area was 85%. According to the 
measurement by DSC, melting point was found only at 233.9.degree. C. 
The styrene polymer was injection molded at melt temperature of 300.degree. 
C. and mold temperature of 100.degree. C. The cross section of this 
injection molded product was observed by electron microscope. As the 
result, fine domain structure with extremely good dispersion was found, 
which can not be observed in the general incompatible mixture. 
The above facts show that this styrene polymer soluble in methylene 
chloride is a crystalline polymer consisting of styrene chain having 
syndiotactic configuration and ethylene-propylene configuration. 
EXAMPLE 11 
In a 1.0-liter reactor equipped with a stirrer which had been purged with 
argon were placed 400 ml of toluene, 700 ml of styrene monomer, 2.5 ml 
(5.0 mmol) of tri-isobutyl aluminum and 5.0 mmol as aluminum atom of 
methylaluminoxane obtained in the above Example 1, and the resultant was 
stirred at the polymerization temperature of 50.degree. C. for 30 minutes. 
Subsequently, 50.0 .mu.mol as titanium atom of 
pentamethylcyclopentadienyltitanium trimethoxide was added. Further, 
propylene monomer was introduced through an exclusive line into the 
reactor, the content of the reactor was sufficiently replaced with 
propylene monomer, pressure in the reactor was increased to 4.5 
kg/cm.sup.2 G. Then, an exclusive line for propylene monomer was blocked 
and ethylene monomer was introduced into the reactor through an exclusive 
line and the pressure was increased to 9.0 kg/cm.sup.2 G. Then, 
polymerization was carried out with stirring at 50.degree. C. for 4 hours. 
Other operations in Example 10 were repeated to obtain styrene polymer. The 
yield of thus obtained styrene polymer was 1.01 g. After the same 
treatment as that in Example 10, the yield of the component soluble in 
methylene chloride was 0.03 g. 
The intrinsic viscosity measured in 1,2,4-trichlorobenzene solution at 
135.degree. C. was 0.95 dl/g. Melting point obtained by DSC measurement 
was 246.0.degree. C. and the composition calculated from .sup.1 H-NMR 
spectrum was 10.8 mol. % of styrene unit, 47.6 mol. % of ethylene unit and 
41.6 mol. % of propylene unit. 
EXAMPLE 12 
In the same manner as that in Example 10, except that 
cyclopentadienyltitanium trichloride was used instead of 
pentamethylcyclopentadienyltitanium trimethoxide, styrene polymer was 
obtained. The yield of the resulting styrene polymer was 5.50 g. After the 
same treatment as that in Example 10, the yield of the component soluble 
in methylene chloride was 0.16 g. 
Melting point of the styrene polymer soluble in methylene chloride was 
232.8.degree. C.. Intrinsic viscosity measured in 1,2,4-trichlorobenzene 
at 135.degree. C. was 1.08 dl/g. The composition calculated from .sup.1 
H-NMR spectrum was 38.7 mol. % of styrene unit, 33.9 mol. % of ethylene 
unit and 27.4 mol. % of propylene unit. 
TABLE 1 
__________________________________________________________________________ 
Styrene Olefin 
MAO.sup.a) 
Monomer Monomer 
Titanium 
Concentration Amount Amount 
Example No. 
Compound 
(mmol) Type (mol) 
Type (kg/cm.sup.2 .multidot. G) 
__________________________________________________________________________ 
Example 1 
Cp*Ti(OCH.sub.3).sub.3.sup.f) 
10 Styrene 
1.73 Ethylene 
8.0 
Example 2 
Cp*Ti(OCH.sub.3).sub.3.sup.f) 
10 Styrene 
1.73 Ethylene 
8.0 
Example 3 
Cp*Ti(OCH.sub.3).sub.3.sup.f) 
10 Styrene 
1.73 Ethylene 
8.0 
Example 4 
Cp*Ti(OCH.sub.3).sub.3.sup.f) 
10 Styrene 
1.30 Ethylene 
8.0 
Example 5 
Cp*Ti(OCH.sub.3).sub.3.sup.f) 
10 Styrene 
1.30 Ethylene 
8.0 
Example 6 
CpTiCl.sub.3.sup.j) 
30 Styrene 
0.65 Ethylene 
8.0 
Example 7 
TET.sup.k) 
5 Styrene 
0.45 Ethylene 
8.0 
Example 8 
Cp*Ti(OCH.sub.3).sub.3.sup.f) 
10 p-Methyl- 
0.76 Ethylene 
8.0 
Styrene 
Example 9 
Cp*Ti(OCH.sub.3).sub.3.sup.f) 
10 p-Methyl- 
0.76 Ethylene 
8.0 
Styrene 
Comparative 
TET.sup.k) 
5 Styrene 
0.50 -- -- 
Example 1 
Comparative 
CpTiCl.sub.3.sup.j) 
30 -- -- Ethylene 
8.0 
Example 2 
__________________________________________________________________________ 
Properties of Copolymer 
Izod 
Polymerization 
Intrinsic 
Content of 
Transition 
Impact 
Temperature 
Yield 
Viscosity.sup.b) 
Olefin Unit 
Temperature (.degree.C.) 
Value.sup.e) 
Example No. 
(.degree.C.) 
(g) (dl/g) 
(wt %) 
Tg.sup.c) 
Tm.sup.d) 
(kgcm/cm) 
__________________________________________________________________________ 
Example 1 
70 12.2 
1.30 4.0 80 262 2.8 
Example 2 
20 45.5 
5.01 50.0 **.sup.h) 
268/126 
4.5 
Example 3 
20 37.4 
3.08 32.0 **.sup.h) 
266/125 
3.5 
Example 4 
60 29.4 
8.70 53.5 **.sup.h) 
261/126 
3.6 
Example 5 
60 50.3 
4.73 78.0 **.sup.h) 
260/126 
4.6 
Example 6 
50 6.3 0.40 0.5 88 260 2.6 
Example 7 
50 2.0 0.87 0.7 87 265 2.7 
Example 8 
60 31.2 
7.78 38.0 **.sup.h) 
***.sup.i) /122 
2.2 
Example 9 
60 63.1 
0.73 52.2 **.sup.h) 
***.sup.i) /121 
2.7 
Comparative 
50 18.7 
1.32 -- 96 267 2.0 
Example 1 
Comparative 
50 3.4 1.50 100.0 -90 126 5.6 
Example 2 
__________________________________________________________________________ 
.sup.a) Methylaluminoxane 
.sup.b) Measured in 1,2,4trichlorobenzene solution at 135.degree. C. 
.sup.c) Glass transition temperature 
.sup.d) Melt temperature (Melting point) 
.sup.e) Measured according to JISK7110 
.sup.f) Pentamethylcyclopentadienyltitanium trimethoxide 
.sup.h) The peak cannot be observed because it overlaps with melting poin 
peak of polyethylene 
.sup.i) Stereostructure of pmethylstyrene chain had been confirmed by 
.sup.13 CNMR 
.sup.j) Cyclopentadienyltitanium trichloride 
.sup.k) Tetraethoxytitanium 
EXAMPLE 13 
(1) Preparation of styrene-1,3-Butadiene Copolymer 
In a 1.0-liter reactor equipped with a stirrer were placed 100 ml of 
styrene and 6.0 mmol as aluminum atom of methylaluminoxane obtained in the 
above Example 1 (1), and the resultant was stirred at the polymerization 
temperature of 30.degree. C. for 30 minutes. Subsequently, 56.3 g of 
1,3-butadiene was charged in a stainless steel catalyst-input tube which 
had been sufficiently replaced with nitrogen, and added to the reaction 
system, and, at the same time, 0.03 mmol as titanium atom of 
pentamethylcyclopentadienyltitanium trimethoxide was added. And 
polymerization was carried out at 40.degree. C. for 5 hours with stirring. 
After reaction was over, methanol was poured to stop the reaction. 
Further, a mixture of methanol-hydrochloric acid was added to decompose 
the catalyst components. Then, washing with methanol was repeated three 
times. The yield of thus obtained styrene-1,3-butadiene copolymer was 41.4 
g. Intrinsic viscosity measured in 1,2,4-trichlorobenzene at 135.degree. 
C. was 1.63 dl/g. 
The fact that styrene chain of this styrene-1,3-butadiene copolymer has 
syndiotactic configuration was certified by the result of analysis by 
differential scanning calorimeter (DSC) and nuclear magnetic resonance 
spectrum (NMR). 
(a) Determination by DSC 
After the styrene copolymer obtained in Example 13 was completely dried, 10 
mg portion was charged in a vessel for DSC. The temperature was increased 
from 50.degree. C. to 300.degree. C. at a rate of 20.degree. C./min, then 
kept at 300.degree. C. for 5 minutes, and decreased from 300.degree. C. to 
50.degree. C. at a rate of 20.degree. C./min. This sample was heated again 
from 50.degree. C. to 300.degree. C. at a rate of 20.degree. C./min, and 
the endo- and exothermic pattern was observed. The apparatus used was 
DSC-II manufactured by Perkin-Elmer Co. 
As the result, the glass transition temperature (Tg) and the melt 
temperature (melting point) (Tm) of this copolymer was 82.degree. C. and 
269.degree. C., respectively. 
The facts that the conventional atactic polystyrenes do not have melt 
temperature, the melt temperature of isotactic polystyrene is 230.degree. 
C. and the melt temperature of copolymer never exceeds the higher melt 
temperature of homopolymers show that the styrene chain of this copolymer 
has syndiotactic configuration and the copolymer is crystalline substance. 
(b) Determination by .sup.13 C-NMR 
The above styrene copolymer was analyzed in 1,2,4-trichlorobenzene solution 
at 135.degree. C. As the result, the aromatic signals were observed at 
145.1 ppm and 145.9 ppm. Accordingly, the styrene chain was confirmed to 
have syndiotactic configuration. Further, signals due to butadiene chain 
were found at 22.3 ppm and 27.5 ppm. The content of 1,3-butadiene chain in 
the copolymer was 8.0 wt. %. The apparatus used was FX-200 manufactured by 
Nippon Denshi Co. 
(c) Morphology of the products 
The copolymer was injection molded at melt temperature of 300.degree. C. 
and at mold temperature of 100.degree. C. The cross section of the 
injection molded product was observed. As the result, it showed good 
dispersion state with only very small domains dispersed therein, which can 
not be observed in the general incompatible mixture. Izod impact value of 
the molded product was measured according to JIS-K7110. 
The results are shown in Table 2. Further, gloss was observed with the 
naked eye to find that gloss of the product was improved by 
copolymerization. 
The above facts show that the copolymer is a crystalline styrene-butadiene 
copolymer which contains styrene chain having syndiotactic configuration. 
Further, moldability was improved by decreasing Tg, and flexibility was 
imparted to improve impact resistance. Moreover, gloss was improved. 
EXAMPLES 14 TO 16 AND COMATIVE EXAMPLES 3 TO 5 
The procedure to Example 13 was repeated using starting materials, 
catalysts and polymerization conditions shown in the following Table 2, 
and styrene-butadiene copolymers or styrene-isoprene copolymers were 
obtained. The characteristics of the resulting copolymers as well as the 
result of Example 13 are shown in Table 2. 
TABLE 2 
__________________________________________________________________________ 
Catalyst Monomer 
Titanium Compound Styrene Monomer 
Comonomer Polymerization 
Amount 
MAO Amount Amount 
Temperature 
Example No. 
Type (mmol) 
(mmol) 
Type (mmol) 
Type (mmol) 
(.degree.C.) 
__________________________________________________________________________ 
Example 13 
Cp*Ti(OCH.sub.3).sub.3.sup.m) 
0.03 6 Styrene 
1.30 1,3-Butadiene 
1.04 30 
Example 14 
Cp*Ti(OCH.sub.3).sub.3.sup.m) 
0.03 6 Styrene 
1.30 Isoprene 
1.50 30 
Example 15 
CpTiCl.sub.3.sup.n) 
0.03 30 Styrene 
1.25 1,3-Butadiene 
0.25 20 
Example 16 
CpTiCl.sub.3.sup.n) 
0.03 30 Styrene 
0.25 Isoprene 
0.25 50 
Comparative 
CpTiCl.sub.3.sup.n) 
0.03 30 Styrene 
0.50 -- -- 50 
Example 3 
Comparative 
CpTiCl.sub.3.sup.n) 
0.03 30 -- -- 1,3-Butadiene 
8.0 50 
Example 4 
Comparative 
CpTiCl.sub.3.sup.n) 
0.03 30 -- -- Isoprene 
8.0 50 
Example 5 
__________________________________________________________________________ 
Copolymer 
Glass 
Intrinsic 
Content of 
Transition 
Melting 
Yield 
Viscosity.sup.q) 
Diene Temperature 
Temperature 
Izod Impact Value 
Example No. 
(g) (dl/g) 
(wt %) 
(.degree.C.) 
(.degree.C.) 
(kgcm/cm) 
Gloss.sup.r) 
__________________________________________________________________________ 
Example 13 
41.4 
1.63 8.0 82.0 269 3.7 .smallcircle. 
Example 14 
34.9 
0.86 10.0 82.0 270 4.3 .circleincircle. 
Example 15 
14.3 
0.62 0.9 90.0 259 1.5 .smallcircle. 
Example 16 
2.9 0.35 0.5 91.0 264 1.4 .DELTA. 
Comparative 
16.2 
1.12 -- 97.0 268 1.0 .DELTA. 
Example 3 
Comparative 
11.6 
0.74 100 -102.0 87 *.sup.s) 
*.sup.s) 
Example 4 
Comparative 
2.0 0.80 100 -73.0 6 *.sup.s) 
*.sup.s) 
Example 5 
__________________________________________________________________________ 
.sup.m) Pentamethylcyclopentadienyltitanium trimethoxide 
.sup.n) Cyclopentadienyltitanium trichloride 
.sup.p) Methylaluminoxane 
.sup.q) Meausred in 1,2,4trichlorobenzene at 135.degree. C. 
.sup.r) Estimated by visual observation 
.circleincircle.: very good 
.smallcircle.: good 
.DELTA.: bad 
.sup.s) Molding by Injection molding was difficult. 
INDUSTRIAL APPLICABILITY 
The styrene copolymer of the present invention possesses heat resistance 
and chemical resistance of syndiotactic polystyrene, and can be injection 
molded at low temperature because of its reduced glass transition 
temperature. Further, gloss and flexibility are greatly improved. 
Particularly, styrene copolymer consisting of styrene monomer (a) and 
olefin monomer (b) is excellent in compatibility with polyolefin. 
Accordingly, the styrene copolymer of the present invention is useful as 
various kinds of structural materials and compatibilizing agent. Such 
copolymer can be efficiently produced according to the process of the 
present invention.