Process for producing unsaturated group-terminated isobutylene polymer

The present invention provides a novel halogen-free solvent system which can produce a good isobutylene polymer and can be easily reused. A novel process for the production of an isobutylene polymer is provided which comprises using a hydrocarbon solvent having a boiling point of not lower than 105.degree. C. and a melting point of not higher than -90.degree. C. Heretofore, a solvent system containing a halogenated hydrocarbon such as methylene chloride has been used for the production of an isobutylene polymer. However, such a solvent system has a great adverse effect on the environment. Therefore, a non-halogenated solvent is desirable. The present invention is characterized by the use of a hydrocarbon solvent as a reaction solvent. The resulting polymer has good properties. Further, compounds which are produced as by-products during the reaction can be easily removed, enabling the recycling of the solvent used. Thus, the production cost can be reduced.

FIELD OF THE INVENTION 
The present invention relates to a process for producing an isobutylene 
polymer having a functional group. More particularly, the present 
invention relates to a solvent for use in the polymerization reaction. 
BACKGROUND OF THE INVENTION 
A terminal functional polymer (e.g., a polymer having a vinyl group at both 
terminals thereof) is useful as materials for producing photo-setting 
resins, UV-setting resins, electron radiation-curing resins, sealing 
compounds for electronics, adhesives, modifiers, coating materials, 
constructional sealings, sealing compounds for laminating glasses, 
gaskets, medical adhesives or sealings, insulation, etc. 
It is known that an isobutylene polymer having, for example, a chlorine 
atom bonded to a tertiary carbon, as a terminal functional polymer can be 
prepared by an inifer method which comprises the cationic polymerization 
of isobutylene with the use of 1,4-bis(.alpha.-chloroisopropyl)benzene 
(hereinafter, simply referred to as "p-DCC") or 
1,3,5-tris(.alpha.-chloroisopropyl)benzene (hereinafter, simply referred 
to as "TCC") as an initiator and boron trichloride as a catalyst (cf. U.S. 
Pat. No. 4,276,394). 
Furthermore, many reports have been made by Kennedy et al. that when the 
foregoing cationic polymerization reaction is effected in a solvent 
containing a halogenated hydrocarbon such as methyl chloride and methylene 
chloride in the presence of an electron donor, an isobutylene polymer 
having a small Mw/Mn as determined by GPC (i.e., a polymer having a 
regular molecular weight) can be obtained (J. Macromol. Sci. Chem., A18 
(1), 25 (1982), Polym. Bull., 20, 413 (1988), Polym. Bull., 26, 305 (1991) 
and JP-A-1-318014 (corresponding to U.S. Pat. No. 5,169,914) (The term 
"JP-A" as used herein means an "unexamined published Japanese patent 
application")). 
As mentioned above, a halogenated hydrocarbon gives a proper dielectric 
constant to stabilize the growth terminal. Thus, such a halogenated 
hydrocarbon is widely used as a solvent for cationic polymerization. 
However, a halogenated hydrocarbon is disadvantageous in that it is 
difficult to handle and it needs much care to prevent environmental 
pollution. 
In other words, methyl chloride has a boiling point as low as -23.7.degree. 
C. and a high toxicity. Legally speaking, methyl chloride is designated as 
a high pressure gas as well as a toxic gas, and thus is a substance which 
is extremely difficult to handle. 
On the other hand, methyl chloride has a water-solubility as high as 2.0% 
(20.degree. C.). Further, it is difficult to make methylene chloride 
dissolved in water harmless. Thus, it has been desired to use a safer 
solvent as a substitute for such a halogenated hydrocarbon. 
One of the objects of the present invention is to provide a novel 
non-halogenated hydrocarbon solvent component which can give a good 
isobutylene polymer. 
The synthesis of an isobutylene polymer by the inifer process is mainly 
characterized by easy introduction of an olefinically functional group 
into the ends of the polymer. As the method for the introduction of olefin 
into the ends of an isobutylene polymer, there has been known a method 
which comprises allowing an allyltrimethylsilane to act on the chlorine 
group end of the isobutylene polymer in the presence of a Lewis acid to 
introduce an allyl group into the isobutylene polymer (JP-A-63-105005 and 
U.S. Pat. No. 4,758,631). This reaction also produces 
trimethylchlorosilane. After this reaction, the deactivation of the Lewis 
acid is effected by the use of water. Accordingly, trimethylchlorosilane 
produced by the allylation reaction at the ends of the isobutylene polymer 
is decomposed to give hexamethyldisiloxane. 
Hexamethyldisiloxane thus produced in the reaction system inhibits the 
polymerization reaction for the preparation of an isobutylene polymer. In 
other words, when the polymerization reaction is effected in a solvent 
system containing hexamethyldisiloxane, the resulting polymer 
disadvantageously has a great dispersion (Mw/Mn). Thus, the polymerization 
reaction is preferably effected in a solvent system substantially free of 
hexamethyldisiloxane. 
Accordingly, it is necessary that hexamethyldisiloxane is removed from a 
reaction solvent in consideration of its reuse in the production of an 
isobutylene polymer. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide a novel 
halogen-free solvent component which can produce a good isobutylene 
polymer and a solvent system which can be easily reused. 
It is another object of the present invention to provide a hydrocarbon 
solvent component from which hexamethyldisiloxane can be easily removed by 
distillation. 
These and other objects of the present invention will become more apparent 
from the following detailed description and examples. 
The present inventors have conducted extensive investigation to find out a 
solvent substituting for the halogenated hydrocarbon. As a result, the 
present invention has been accomplished based on the findings. 
In the present invention, it is necessary that hexamethyldisiloxane 
produced after reaction be removed. 
Since this compound has a boiling point of 100.degree. C., any solvent 
having a lower or higher boiling point than this compound may be employed. 
In other words, hexamethyldisiloxane can be removed from such a solvent by 
distillation after reaction in principle. 
After the completion of reaction, the solvent contains hexamethyldisiloxane 
in an amount of not more than 2% by weight based on the weight of the 
reaction solution assuming that hexamethyldisiloxane is quantitatively 
produced from the allylsilane used. In the distillation process for the 
removal of hexamethyldisiloxane, hexamethyldisiloxane can be 
advantageously removed as a forerun by selecting a solvent having a higher 
boiling point than that of hexamethyldisiloxane from the standpoint of the 
thermal efficiency of distillation or the cost of the still. Therefore, 
the boiling point of the solvent to be used is preferably higher than that 
of hexamethyldisiloxane. The inventors made studies of a solvent system 
which can meet these requirements to provide a good isobutylene polymer. 
As a result, an effective solvent system has been found. 
The constitution of the present invention is as follows: 
1. A process for producing an isobutylene polymer, which comprises 
performing a reaction in a hydrocarbon solvent having a boiling point of 
not lower than 105.degree. C. and a melting point of not higher than 
-90.degree. C. 
2. A process for producing an isobutylene polymer, which comprises mixing 
the following components (1) to (6) at a temperature of from -100.degree. 
C. to 0.degree. C.: 
(1) a cation polymerizable monomer containing isobutylene; 
(2) a compound represented by formula (I): 
##STR1## 
wherein R.sup.1 represents an aromatic ring group, or a substituted or 
unsubstituted aliphatic hydrocarbon group; R.sup.2 and R.sup.3 may be the 
same or different and each represents a hydrogen atom, or substituted or 
unsubstituted monovalent hydrocarbon group, with the proviso that when 
R.sup.1 is an aliphatic hydrocarbon group, a R.sup.2 and R.sup.3 are not a 
hydrogen atom at the same time; X represents a halogen atom, a R.sup.4 
COO-- group (in which R.sup.4 represents a hydrogen atom or a C.sub.1-5 
alkyl group) or a R.sup.5 O-- group (in which R.sup.5 represents a 
hydrogen atom or a C.sub.1-5 alkyl group); and n represents an integer of 
from 1 to 8; 
(3) a Lewis acid; 
(4) an electron donating component, in which a donor number defined as a 
parameter indicating the intensity of a various compound as an electron 
donor is from 15 to 50; 
(5) a hydrocarbon solvent having a boiling point of not lower than 
105.degree. C. and a melting point of not higher than -90.degree. C.; and 
(6) an allyltrimethylsilane. 
3. The process for the production of an isobutylene polymer according to 
the above 1 or 2, wherein the reaction system does not substantially 
contain hexamethyldisiloxane from the hydrocarbon solvent having a boiling 
point of not lower than 105.degree. C. and a melting point of not higher 
than -90.degree. C. when the reaction is effected in the hydrocarbon 
solvent. 
4. The process for the production of an isobutylene polymer according to 
any one of the above 1 to 3, wherein the hydrocarbon solvent having a 
boiling point of not lower than 105.degree. C. and a melting point of not 
higher than -90.degree. C. is selected from the group consisting of 
toluene, ethylcyclohexane, 2,2,3-trimethylpentane and 
2,2,5-trimethylhexane. 
5. The process for the production of an isobutylene polymer according to 
the above 4, wherein the hydrocarbon solvent having a boiling point of not 
lower than 105.degree. C. and a melting point of not higher than 
-90.degree. C. is a mixture of toluene and ethylcyclohexane. 
6. The process for the production of an isobutylene polymer according to 
the above 5, wherein the mixing ratio of toluene and ethylcyclohexane by 
volume is from 8:2 to 7:3. 
7. The process for the production of an isobutylene polymer according to 
any one of the above 2 to 6, wherein the Lewis acid component is selected 
from the group consisting of boron trichloride, titanium tetrachloride and 
tin tetrachloride. 
8. The process for the production of an isobutylene polymer according to 
any one of the above 2 to 7, wherein the electron donating component is 
selected from the group consisting of pyridines, amines, amides and 
sulfoxides. 
9. The process for the production of an isobutylene polymer according to 
the above 2, wherein the amount of the components (1) to (4) and (6) are 
each regulated to the level as defined below: 
(1) the concentration of a cation polymerizable monomer containing 
isobutylene ranges from 0.1 to 10 mol/l; 
(2) the amount of the compound represented by the formula (1) ranges from 
0.01 to 20% by weight based on the weight of the cation polymerizable 
monomer containing isobutylene; 
(3) the amount of a Lewis acid is from 0.1 to 100 times by mol as much as 
the compound represented by the formula (1); 
(4) the amount of an electron donating component is from 0.01 to 10 times 
by mol as much as the compound represented by the formula (I); and 
(6) the amount of the allyltrimethylsilane is from 0.75 to 1.5 times by mol 
as much as the terminal functional group in the compound represented by 
the formula (I). 
10. An isobutylene polymer produced by mixing the following components (1) 
to (6) at a temperature of from -100.degree. C. to 0.degree. C.: 
(1) a cation polymerizable monomer containing isobutylene; 
(2) a compound represented by formula (I): 
##STR2## 
wherein R.sup.1 represents an aromatic ring group, or a substituted or 
unsubstituted aliphatic hydrocarbon group; R.sup.2 and R.sup.3 may be the 
same or different and each represents a hydrogen atom, or substituted or 
unsubstituted monovalent hydrocarbon group, with the proviso that when 
R.sup.1 is an aliphatic hydrocarbon group, a R.sup.2 and R.sup.3 are not a 
hydrogen atom at the same time; X represents a halogen atom, a R.sup.4 
COO-- group (in which R.sup.4 represents a hydrogen atom or a C.sub.1-5 
alkyl group) or a R.sup.5 O-- group (in which R.sup.5 represents a 
hydrogen atom or a C.sub.1-5 alkyl group); and n represents an integer of 
from 1 to 8; 
(3) a Lewis acid; 
(4) an electron donating component, in which a donor number defined as a 
parameter indicating the intensity of a various compound as an electron 
donor is from 15 to 50; 
(5) a hydrocarbon solvent having a boiling point of not lower than 
105.degree. C. and a melting point of not higher than -90.degree. C.; and 
(6) an allyltrimethylsilane. 
11. The production of an isobutylene polymer according to the above 10, 
wherein the amount of the components (1) to (4) and (6) are each regulated 
to the level as defined below: 
(1) the concentration of a cation polymerizable monomer containing 
isobutylene ranges from 0.1 to 10 mol/l; 
(2) the amount of the compound represented by the formula (1) ranges from 
0.01 to 20% by weight based on the weight of the cation polymerizable 
monomer containing isobutylene; 
(3) the amount of a Lewis acid is from 0.1 to 100 times by mol as much as 
the compound represented by the formula (1); 
(4) the amount of an electron donating component is from 0.01 to 10 times 
by mol as much as the compound represented by the formula (I); and 
(6) the amount-of the allyltrimethylsilane is from 0.75 to 1.5 times by mol 
as much as the terminal functional group in the compound represented by 
the formula (I). 
DETAILED DESCRIPTION OF THE INVENTION 
In the present invention, the number-average molecular weight (Mn) and 
Mw/Mn value (Mw: weight-average molecular weight) of the isobutylene 
polymer having unsaturated group is determined by GPC using a polystyrene 
gel column (Shodex K-804, available from Showa Denko K.K.; mobile phase: 
chloroform) as calculated in terms of polystyrene. 
In the present invention, the number-average molecular weight (Mn) of the 
isobutylene polymer determined by GPC usually ranges from 500 to 300,000, 
preferably from 1,000 to 50,000. An isobutylene polymer having Mn of lower 
than 500 has no excellent properties inherent to isobutylene polymer. On 
the contrary, an isobutylene polymer having Mn of more than 300,000 
becomes so solid that it is extremely difficult to work. 
In the present invention, the cation polymerizable monomer containing 
isobutylene is not limited to a monomer comprising isobutylene alone. It 
means a monomer having nor more than 50 mol % (hereinafter, simply 
referred to as "%") of isobutylene substituted by a cation polymerizable 
monomer copolymerizable with isobutylene. 
Examples of the cation polymerizable monomer copolymerizable with 
isobutylene include C.sub.3-12 olefins, conjugated dienes, vinyl ethers, 
aromatic vinyl compounds, norbornenes, and vinylsilanes. Preferred among 
these compounds are C.sub.3-12 olefins and aromatic vinyl compounds. 
Specific examples of the cation polymerizable monomer copolymerizable with 
isobutylene as described above usually include propene, 1-butene, 
2-butene, 2-methyl-1-butene, 3-methyl-1-butene, pentene, hexene, 
cyclohexene, vinylcyclohexane, 5-ethylidenenorbornene, 
5-propylidenenorbornene, butadiene, isoprene, cyclopentadiene, methyl 
vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, vinylcarbazole, 
methoxystyrene, ethoxystyrene, t-butoxystyrene, hexenyloxystyrene, 
styrene, .alpha.-methylstyrehe, methylstyrene, dimethylstyrene, 
chloromethylstyrene, chlorostyrene, indene, .beta.-pinene, 
vinyltrichlorosilane, vinylmethyldichlorosilane, 
vinyldimethylchlorosilane, vinyldimethylmethoxysilane, 
vinyltrimethylsilane, divinyldichlorosilane, divinyldimethoxysilane, 
divinyldimethylsilane, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 
trivinylmethylsilane, .gamma.-methacryloyloxypropyltrimethoxysilane, and 
.gamma.-methacryloyloxypropylmethyldimethoxysilane. 
Preferred among these compounds are propene, 1-butene, 2-butene, 
cyclopentadiene, 5-ethylidenenorbornene, isobutyl vinyl ether, 
methoxystyrene and styrene. These cation polymerizable monomers 
copolymerizable with isobutylene may be used individually or in 
combination of two or more thereof. In the present invention, the 
concentration of the cation polymerizable monomer containing isobutylene 
to be used, for example, in a batch process, is usually from 0.1 to 10 
mol/l, preferably from 0.5 to 6 mol/l. 
Examples of the compound represented by the formula (I) to be used herein 
include a compound represented by the following formula (II): 
EQU AY.sub.n (II) 
wherein A represents a group having from 1 to 4 aromatic rings; Y 
represents a group, which is bonded to an aromatic ring, represented by 
the following formula (III): 
##STR3## 
wherein R.sup.6 and R.sup.7 may be the same or different and each 
represents a hydrogen atom or a C.sub.1-20 monovalent hydrocarbon group; X 
represents a halogen atom, a R.sup.4 COO-- group (in which R.sup.4 
represents a hydrogen atom or a C.sub.1-5 alkyl group) or a R.sup.5 O-- 
group (in which R.sup.5 represents a hydrogen atom or a C.sub.1-5 alkyl 
group); and n represents an integer of from 1 to 8; a compound represented 
by the following formula (IV): 
EQU BZ.sub.m (IV) 
wherein B represents a C.sub.4-40 (preferably C.sub.9-20) substituted or 
unsubstituted hydrocarbon group; Z represents a halogen atom bonded to the 
tertiary carbon atom, a R.sup.8 COO-- group (in which R.sup.8 represents a 
hydrogen atom or a C.sub.1-5 alkyl group) or a R.sup.9 O-- group (in which 
R.sup.9 represents a hydrogen atom or a C.sub.1-5 alkyl group); and m 
represents an integer of from 1 to 4; and oligomers having an 
.alpha.-halostyrene unit. However, the present invention is not limited to 
these compounds. These compounds may be used individually or in 
combination. 
The group A having 1 to 4 aromatic rings in the compound represented by the 
formula (II) may be either a product of condensation reaction or one of 
the uncondensed type. Examples of such a group having aromatic rings 
include phenyl, biphenyl, naphthyl, anthracene, phenanthrenyl, pyrenyl and 
Ph-(CH.sub.2).sub.L -Ph (Ph represents a phenyl group, and L represents an 
integer of from 1 to 10) groups having a valence of from 1 to 6. These 
groups having aromatic rings may be substituted by a C.sub.1-20 
straight-chain and/or branched aliphatic hydrocarbon group or a group 
having a functional group such as a hydroxyl group, an ether group and a 
vinyl group. 
Examples of the compound represented by the formula (IV) to be used herein 
include compounds having a functional group other than Z, such as a vinyl 
group and a silyl group. 
Examples of the oligomer having .alpha.-halostyrene unit, which can be used 
as an initiator/chain transfer agent, include .alpha.-chlorostyrene 
oligomer and oligomers obtained by the copolymerization of 
.alpha.-chlorostyrene with a monomer copolymerizable therewith. 
In the present invention, if, among the compounds represented by the 
formula (I), a compound having a two or more halogen atoms, R.sup.4 COO-- 
groups (in which R.sup.4 represents a hydrogen atom or a C.sub.1-5 alkyl 
group) or R.sup.5 O-- groups (in which R.sup.5 represents a hydrogen atom 
or a C.sub.1-5 alkyl group), or a compound having a halogen atom, a 
R.sup.4 COO-- group or a R.sup.5 O-- group together with other reactive 
functional group(s) is used as an initiator/chain transfer agent, the 
resulting polymer can be rendered more functional to advantage. 
Specific examples of the compound represented by the formula (I) to be used 
herein include: 
##STR4## 
wherein X represents a halogen atom, a R.sup.4 COO-- group (in which 
R.sup.4 represents a hydrogen atom or a C.sub.1-5 alkyl group) or R.sup.5 
O-- group (in which R.sup.5 represents a hydrogen atom or C.sub.1-5 alkyl 
group); and .alpha.-chlorostyrene oligomer. However, the present invention 
is not limited to these compounds. Among these compounds, the following 
compounds are preferred: 
##STR5## 
those having a CH.sub.3 COO-- group such as: 
##STR6## 
and those having a CH.sub.3 O-- group such as: 
##STR7## 
These compounds are used as an initiator. In the present invention, these 
compounds may be used individually or in combination. By properly 
controlling the amount of these compounds used, the number-average 
molecular weight of the resulting isobutylene polymer can be arbitrarily 
determined. 
In the present invention, the amount of the compound represented by the 
formula (I) to be used is usually from 0.01 to 20% by weight, preferably 
from 0.1 to 10% by weight based on the weight of the cation polymerizable 
monomer containing isobutylene. 
Examples of the Lewis acid to be used herein usually include metal halides 
such as AlCl.sub.3, SnCl.sub.4, TiCl.sub.4, VCl.sub.5, FeCl.sub.3, 
BCl.sub.3 and BF.sub.3, and organic aluminum compounds such as Et.sub.2 
AlCl and EtAlCl.sub.2. However, the present invention is not limited to 
these compounds. Preferred among these compounds are SnCl.sub.4, 
TiCl.sub.4, and BCl.sub.3. 
In the present invention, the Lewis acid is usually used in an amount of 
from 0.1 to 100 times by mol, preferably from 0.3 to 30 times by mol, as 
much as the compound represented by the formula (I). 
In the present invention, the electron donating component to be used herein 
may be selected from a broad range of the publicly known compounds, so 
long as the donor number thereof is 15 to 50. Preferred examples of the 
electron donating component include pyridines, amines, amides and 
sulfoxides. However, the present invention is not limited to these 
compounds. 
Specific examples of the electron donating component to be used in the 
present invention, in which a donor number defined as a parameter 
indicating the intensity of an electron donor of various compounds is from 
15 to 50 (the various donor numbers are disclosed, for example, in V. 
Gutman, Donor and Acceptor, (translated by Otaki and Okada) Gakkai Shuppan 
Center (1983)) generally include 2,6-di-t-butylpyridine, 
2-t-butylpyridine, 2,4,6-trimethylpyridine, 2,6-dimethylpyridine, 
2-methylpyridine, pyridine, diethylamine, trimethylamine, triethylamine, 
tributylamine, diethylamine, N,N-dimethylaniline, aniline, 
N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, 
dimethyl sulfoxide, diethyl ether, methyl acetate, ethyl acetate, 
trimethyl phosphate, tributyl phosphate and triamide hexamethylphosphate. 
Preferred among these electron donors are 2,6-di-t-butylpyridine, 
2,6-dimethylpyridine, 2-methylpyridine, pyridine, diethylamine, 
trimethylamine, triethylamine, N,N-dimethylformamide, 
N,N-dimethylacetamide, and dimethyl sulfoxide, more preferably picolines. 
Particularly preferred among these electron donors is 2-methylpyridine, 
which can exert a remarkable effect when added regardless of its 
relatively small donor number contained therein. 
In the present invention, the electron donating component is usually used 
in an amount of from 0.01 to 10 times by mol, preferably from 0.2 to 2 
times by mol, as much as the compound represented by the formula (I). 
As the solvent which can be used in the present invention, there may be 
normally used a compound having a boiling point of not lower than 
105.degree. C. and a melting point of not higher than -90.degree. C. as 
determined in the form of single solvent. Alternatively, hydrocarbon 
compounds, which do not solidify at the reaction temperature, may be used 
as a mixed solvent in the reaction. 
Example of the hydrocarbon solvent having a boiling point of not lower that 
105.degree. C. and a melting point of not higher than -90.degree. C. may 
be selected from various solvents. One of the measures for the selection 
of the solvents is preferably to elect such a solvent that does not 
precipitate the desired isobutylene polymer in the course of the 
polymerization reaction. If the isobutylene polymer is precipitated during 
the polymerization reaction, the properties of the resulting polymer are 
deteriorated. Also, even in case of the solvent which does not precipitate 
the desired isobutylene polymer during the polymerization reaction, it is 
preferred from the viewpoint of the commercial production to select a 
solvent having a solubility of 15% by weight or more (15 g; the total 
amount of the isobutylene polymer dissolved in 100 g of the solvent at 
-70.degree. C.), more preferably 19% by weight or more, most preferably 
22% by weight or more. However, it is not limited so long as the desired 
isobutylene polymer is dissolved without precipitating during the 
polymerization reaction. Further, the hydrocarbon solvent having a boiling 
point of not lower than 105.degree. C. and a melting point of not higher 
than -90.degree. C. may be used together with a halogenated hydrocarbon 
solvent, so long as the combined use does not suffer from defects such 
that it is difficult to handle the solvents, it is difficult to operate 
the polymerization and it needs much care to present environmental 
pollution. 
Among hydrocarbon solvents having a boiling point of not lower than 
105.degree. C. and a melting point of not higher than -90.degree. C., 
toluene, ethyl cyclohexane, 2,3,3-trimethylpentane and 
2,2,5-trimethylhexane are preferably selected. A particularly preferred 
example of such a hydrocarbon solvent is a mixture of toluene and ethyl 
cyclohexane. 
As the terminal functionalizer which can be used in the present invention, 
an allyltrimethylsilane is used. The allyltrimethylsilane is normally used 
in an amount of from 0.75 to 1.5 equivalents, preferably from 1 to 1.5 
equivalents to the number of functional groups in the polyfunctional 
initiator. For example, if a bifunctional initiator such as p-DCC is used, 
the allyltrimethylsilane is normally used in an amount of from 2 to 3 
times by mol as much as the initiator used. When the reaction is effected 
in the presence of an allyltrimethylsilane in an amount of 2 times by mol 
as much as the initiator, the functionalization can proceed 
quantitatively. Therefore, the allyltrimethylsilane is preferably used in 
an amount of 2 times by mol as much as the as initiator. The reaction time 
is usually from 10 to 200 minutes, preferably from 30 to 180 minutes, more 
preferably 90 to 180 minutes. The allyltrimethylsilane can be reacted with 
an isobutylene polymer at the same temperature as in the polymerization 
reaction to obtain a vinyl group-terminated isobutylene polymer. 
In the reaction system of the present invention, the reaction is followed 
by the deactivation of the catalyst with water after the completion of the 
reaction. The deactivation process is accompanied by the reaction of 
trimethylchlorosilane produced when an olefin has been introduced into the 
ends of the polymer in the presence of water resulting in the production 
of hexamethyldisiloxane. If the production of an isobutylene polymer is 
effected in a solvent system containing hexamethyldisilbxane, the 
resulting polymer has an increased dispersion (Mw/Mn), resulting in an 
increase in the viscosity thereof. Therefore, the polymerization reaction 
is preferably effected in a solvent system substantially free of 
hexamethyldisiloxane. 
The viscosity of an isobutylene polymer depends on the molecular weight 
thereof. The more the molecular weight of the isobutylene polymer is, the 
less is the polymer apt to the effect of hexamethyldisiloxane. In a 
polymer having a number-average molecular weight of from 7,000 to 10,000 
as determined by GPC, the viscosity of an isobutylene polymer shows no big 
change if the hexamethyldisiloxane content in the solvent used is not more 
than 1 to 2% by weight. Similarly, in a polymer having a number-average 
molecular weight of from 17,000to 25,000 as determined by GPC, the 
viscosity of an isobutylene polymer shows no big change if the 
hexamethyldisiloxane content in the solvent used is not more than 3% by 
weight. Therefore, it can be considered that substantially no 
hexamethyldisiloxane is contained in the solvent. It is more preferred 
that the polymerization system for the production of an isobutylene 
polymer is free of hexamethyldisiloxane. 
Studies were made of the removal by distillation of hexamethyldisiloxane 
obtained in the solvent by the polymerization reaction. As a result, it 
was found that the hexamethyldisiloxane content in the solvent thus 
obtained is not more than 50 ppm. In this manner, the recycling of the 
solvent is made possible. 
The present invention will be further described in the following Examples, 
but the present invention should not be construed as being limited 
thereto. The molecular weight as used hereinafter is determined by GPC and 
NMR. 
GPC Analysis 
System: analytical system manufactured by Waters Co., Ltd. 
(pump 600E; differential refractometer 401). 
Column: Shodex K-804, manufactured by Showa Denko K.K. 
(polystyrene gel). 
Mobile phase: chloroform 
(Number-average molecular weight, etc. are determined as calculated in 
terms of polystyrene). .sup.1 H-NMR spectrum (300 Hz): Gemini-300, 
manufactured by Valian Corp. 
Fn (vinyl) represents the number of vinyl groups per initiator in the 
isobutylene polymer and can be calculated based on the NMR spectrum data. 
Fn (vinyl)* represents the number of vinyl groups per molecule of the 
isobutylene polymer and can be calculated based on the NMR spectrum and 
GPC data. Fn (vinyl)* can be determined as follows: 
(1) The integral value of the peak attirubutable to H atoms contained in 
each functional group in NMR is determined. 
(2) The integral value obtained in the step (1) is divided by the number of 
H atoms in the respective functional group. (referred to as (1)) 
(3) The value (1) corresponding to the respective functional group is 
divided by the value (1) corresponding to the initiator to give the number 
of functional groups per molecule of oligomer (Fn). 
(4) The molecular weight Mn (GPC) determined by GPC is divided by 56, which 
is the molecular weight of isobutylene group, to determine the number of 
isobutylene groups contained per molecule of oligomer (n*). 
(5) The value (1) corresponding to isobutylene group is divided by n*. 
(referred to as (2)) 
(6) The value (1) corresponding to each functional group is divided by the 
value (2) to determine the number of functional groups per-molecule of 
oligomer (Fn*). 
The viscosity of the isobutylene polymer was measured by means of an E type 
viscometer (VISCONIC EHD, manufactured by Tokyo Keiki K.K.) at a 
temperature of 50.degree. C.

EXAMPLE 1 
A three-way cock was attached to a 500-ml pressure glass container. The air 
in the container was then replaced by nitrogen. Into the container were 
then charged 54 ml of ethyl cyclohexane (which had been dried by allowing 
to stand with a molecular sieve 3A overnight or longer), 126 ml of toluene 
(which had been dried by allowing to stand with a molecular sieve 3A 
overnight or longer) and 1.16 g (5.02 mmol) of p-DCC through a hypodermic 
syringe. Subsequently, to the three-way cock was connected a pressure 
glass tube for collecting a liquefied gas with a needle valve containing 
56 ml of an isobutylene monomer. The polymerization container was cooled 
by immersing in a dry ice/ethanol bath at -70.degree. C. Then, the 
pressure in the container was reduced by means of a vacuum pump. The 
needle valve was then opened to introduce the isobutylene monomer into the 
polymerization container through the liquefied gas collecting tube. 
Nitrogen was then introduced into the polymerization container through one 
of the ways of the three-way cock so that the pressure in the container 
was returned to normal value. Subsequently, 0.093 g (1.0 mmol) of 
2-methylpyridine was added thereto. Further, 1.65 ml (15.1 mmol) of 
titanium tetrachloride was added to the polymerization system to initiate 
polymerization. After 70 minutes of reaction, 1.22 g (10.8 mmol) of an 
allyltrimethylsilane was added to the reaction system so that allyl group 
was introduced into the ends of the polymer. After 120 minutes of 
reaction, the reaction solution was washed with four portions of 200 ml of 
water. The solvent was then evaporated to give an isobutylene polymer. The 
results are shown in Table 1. 
EXAMPLE 2 
The procedure of Example 1 was followed to produce an isobutylene polymer 
except that 0.022% by weight (0.045 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 1. The 
results are shown in Table 1. 
EXAMPLE 3 
The procedure of Example 1 was followed to produce an isobutylene polymer 
except that 0.05% by weight (0.090 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 1. The 
results are shown in Table 1. 
EXAMPLE 4 
The procedure of Example 1 was followed to produce an isobutylene polymer 
except that 0.1% by weight (0.18 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 1. The 
results are shown in Table 1. 
EXAMPLE 5 
The procedure of Example 1 was followed to produce an isobutylene polymer 
except that 0.5% by weight (0.9 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 1. The 
results are shown in Table 1. 
EXAMPLE 6 
The procedure of Example 1 was followed to produce an isobutylene polymer 
except that 1.0% by weight (1.8 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 1. The 
results are shown in Table 1. 
EXAMPLE 7 
The procedure of Example 1 was followed to produce an isobutylene polymer 
except that 2.5% by weight (4.5 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 1. The 
results are shown in Table 1. 
EXAMPLE 8 
The procedure of Example 1 was followed to produce an isobutylene polymer 
except that 5.0% by weight (9.0 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 1. The 
results are shown in Table 1. 
EXAMPLE 9 
The procedure of Example 1 was followed to produce an isobutylene polymer 
except that 10.0% by weight (18.0 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 1. The 
results are shown in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Synthesis (1) of allyl-terminated polyisobutylene in the presence of 
hexamethyldisiloxane (ethylcyclohexane/toluene = 3/7; predetermined 
molecular weight: 10,000) 
Hexamethyl- 
Example 
disiloxane 
GPC NMR Viscosity 
No. (wt %)* 
Mn Mw/Mn 
Mn Fn (vinyl) 
Fn (vinyl)* 
(poise) 
__________________________________________________________________________ 
1 0.0 7,660 
1.36 
8,710 
2.09 1.84 1,638 
2 0.022 8,728 
1.34 
9,689 
2.11 1.90 -- 
3 0.045 8,045 
1.38 
9,520 
2.10 1.77 -- 
4 0.085 7,730 
1.43 
9,010 
2.16 1.85 1,650 
5 0.42 8,057 
1.48 
9,118 
2.09 1.85 -- 
6 0.85 7,649 
1.50 
9,156 
2.12 1.77 1,730 
7 2.25 7,631 
1.52 
8,837 
1.94 1.68 1,690 
8 4.28 7,485 
1.75 
8,906 
2.14 1.80 2,175 
9 9.10 7,208 
2.80 
9,709 
2.26 1.68 4,550 
__________________________________________________________________________ 
*: The amount(wt %) of hexamethyldisiloxane = hexamethyldisiloxane 
(g)/(hexamethyldisiloxane(g) + tolyene (g) + ethylcyclohexane(g)). 
EXAMPLE 10 
A three-way cock was attached to a 500-ml pressure glass container. The air 
in the container was then replaced by nitrogen. Into the container were 
then charged 36 ml of ethyl cyclohexane (which had been dried by allowing 
to stand with a molecular sieve 3A overnight or longer), 144 ml of toluene 
(which had been dried by allowing to stand with a molecular sieve 3A 
overnight or longer) and 447 mg (1.93 mmol) of p-DCC through a hypodermic 
syringe. Subsequently, to the three-way cock was connected a pressure 
glass tube for collecting a liquefied gas with a needle valve containing 
58 ml of an isobutylene monomer. The polymerization container was cooled 
by immersing a dry ice/ethanol bath at -70.degree. C. Then, the pressure 
in the container was reduced by means of a vacuum pump. The needle valve 
was then opened to introduce the isobutylene monomer into the 
polymerization container through the liquefied gas collecting tube. 
Nitrogen was then introduced into the polymerization container through one 
of the ways of the three-way cock so that the pressure in the container 
was returned to normal value. Subsequently, 0.072 g (0.772 mmol) of 
2-methylpyridine was added thereto. Further, 1.67 ml (15.2 mmol) of 
titanium tetrachloride was added to the polymerization system to initiate 
polymerization. After 100 minutes of reaction, 461 mg (4.03 mmol) of an 
allyltrimethylsilane was added to the reaction system so that allyl group 
was introduced into the terminals of the polymer. After 120 minutes of 
reaction, the reaction solution was washed with four portions of 200 ml of 
water. The solvent was then evaporated to give an isobutylene polymer. The 
results are shown in Table 2. 
EXAMPLE 11 
The procedure of Example 10 was followed to produce an isobutylene polymer 
except that 0.89% by weight (1.8 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 10. The 
results are shown in Table 2. 
EXAMPLE 12 
The procedure of Example 10 was followed to produce an isobutylene polymer 
except that 2.2% by weight (4.5 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 10. The 
results are shown in Table 2. 
EXAMPLE 13 
The procedure of Example 10 was followed to produce an isobutylene polymer 
except that 4.5% by weight (9.0 ml) of hexamethyldisiloxane was 
incorporated in the solvent to be added. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 10. The 
results are shown in Table 2. 
TABLE 2 
__________________________________________________________________________ 
Synthesis (1) of allyl-terminated polyisobutylene in the presence of 
hexamethyldisiloxane (ethylcyclohexane/toluene = 2/8; predetermined 
molecular weight: 20,000) 
Hexamethyl- 
Example 
disiloxane 
GPC NMR Viscosity 
No. (wt %) 
Mn Mw/Mn 
Mn Fn (vinyl) 
Fn (vinyl)* 
(poise) 
__________________________________________________________________________ 
10 0.0 22,913 
1.17 
28,858 
2.03 1.61 9,100 
11 0.89 22,003 
1.19 
24,159 
1.96 1.79 9,700 
12 2.22 21,814 
1.20 
25,435 
2.18 1.87 9,720 
13 4.46 20,722 
1.27 
22,155 
2.04 1.87 9,950 
__________________________________________________________________________ 
*: The amount(wt %) of hexamethyldisiloxane = hexamethyldisiloxane 
(g)/(hexamethyldisiloxane(g) + tolyene (g) + ethylcyclohexane(g)). 
The results of these examinations show a phenomenon that a polymer obtained 
from a reaction system containing hexamethyldisiloxane has an increased 
dispersion. It was also found that the dispersion value increases with the 
rise in the amount of hexamethyldisiloxane added. 
EXAMPLE 14 
A three-way cock was attached to a 500-ml pressure glass container. The air 
in the container was then replaced by nitrogen. Into the container were 
then charged 36 ml of ethyl cyclohexane (which had been dried by allowing 
to stand with a molecular sieve 3A overnight or longer), 144 ml of toluene 
(which had been dried by allowing to stand with a molecular sieve 3A 
overnight or longer) and 1.98 g (8.56 mmol) of p-DCC through a hypodermic 
syringe. Subsequently, to the three-way cock was connected a pressure 
glass tube for collecting a liquefied gas with a needle valve containing 
58 ml of an isobutylene monomer. The polymerization container was cooled 
by immersing in a dry ice/ethanol bath at -70.degree. C. Then, the 
pressure in the container was reduced by means of a vacuum pump. The 
needle valve was then opened to introduce the isobutylene monomer into the 
polymerization container through the liquefied gas collecting tube. 
Nitrogen was then introduced into the polymerization container through one 
of the ways of the three-way cock so that the pressure in the container 
was returned to normal value. Subsequently, 0.072 g (0.772 mmol) of 
2-methylpyridine was added thereto. Further, 1.67 ml (15.2 mmol) of 
titanium tetrachloride was added to the polymerization system to initiate 
polymerization. After 40 minutes of reaction, 2.41 g (21.1 mmol, toluene 
solution) of an allyltrimethylsilane was added to the reaction system so 
that allyl group was introduced into the ends of the polymer. After 120 
minutes of reaction, the reaction solution was washed with four portions 
of 200 ml of water. The solvent was then evaporated to give an isobutylene 
polymer. The results are shown in Table 3. 
EXAMPLE 15 
The procedure of Example 14 was followed to produce an isobutylene polymer 
except that the amounts of the isobutylene monomer and p-DCC added were 
changed to 45 ml and 1.55 g (6.7 mmol), respectively. The isobutylene 
polymer thus produced was then evaluated in the same manner as in Example 
14. The results are shown in Table 3. 
TABLE 3 
______________________________________ 
Synthesis of allyl-terminated polyisobutylene in ethylcyclohexane/toluene 
solvent (ethylcyclohexane/toluene = 2/8; predetermined 
molecular weight: 20,000) 
Ex- 
am- Monomer 
ple concentration 
GPC NMR 
No. (wt %) Mn Mw/Mn Mn Fn (vinyl) 
Fn (vinyl)* 
______________________________________ 
14 20 4,937 1.46 6,658 
2.22 1.65 
15 16 4,631 1.52 5,635 
1.87 1.54 
______________________________________ 
The "monomer concentration(wt %)" was calculated from the monomer content 
in the solution, i.e., monomer content/(monomer content + solvent 
content). 
EXAMPLE 16 
A three-way cock was attached to a 300-ml pressure glass container. The air 
in the container was then replaced by nitrogen. Into the container were 
then charged 17.5 ml of ethyl cyclohexane (which had been dried by 
allowing to stand with a molecular sieve 3A overnight or longer), 70.2 ml 
of toluene (which had been dried by allowing to stand with a molecular 
sieve 3A overnight or longer) and 0.58 g (2.5 mmol) of p-DCC through a 
hypodermic syringe. Subsequently, to the three-way cock was connected a 
pressure glass tube for collecting a liquefied gas with a needle valve 
containing 28 ml of an isobutylene monomer. The polymerization container 
was cooled by immersing in a dry ice/ethanol bath at -70.degree. C. Then, 
the pressure in the container was reduced by means of a vacuum pump. The 
needle valve was then opened to introduce the isobutylene monomer into the 
polymerization container through the liquefied gas collecting tube. 
Nitrogen was then introduced into the polymerization container through one 
of the ways of the three-way cock so that the pressure in the container 
was returned to normal value. Subsequently, 0.047 g (0.50 mmol) of 
2-methylpyridine was added thereto. Further, 0.83 ml (7.6 mmol) of 
titanium tetrachloride was added to the polymerization system to initiate 
polymerization. After 60 minutes of reaction, the reaction solution was 
washed with four portions of 100 ml of water. The solvent was then 
evaporated to give an isobutylene polymer. The results are shown in Table 
4. 
EXAMPLE 17 
The procedure of Example 16 was followed to produce an isobutylene polymer 
except that the amounts of ethyl cyclohexane and toluene added were 
changed to 26.8 ml and 62.4 ml, respectively. The isobutylene polymer thus 
produced was then evaluated in the same manner as in Example 16. The 
results are shown in Table 4. 
EXAMPLE 18 
The procedure of Example 16 was followed to produce an isobutylene polymer 
except that the amounts of ethyl cyclohexane and toluene added were 
changed to 35.8 ml and 53.7 ml, respectively, and no allyltrimethylsilane 
was added. The isobutylene polymer thus produced was then evaluated in the 
same manner as in Example 16. The results are shown in Table 4. 
TABLE 4 
______________________________________ 
Synthesis of allyl-terminated polyisobutylene in ethylcyclohexane/toluene 
solvent 
Ex- 
am- 
ple EtCy/Toluene 
GPC NMR 
No. (solvent ratio) 
Mn Mw/Mn Mn Fn (vinyl) 
Fn (vinyl)* 
______________________________________ 
16 2/8 6,700 1.40 7,700 
2.17 1.86 
17 3/7 7,700 1.36 8,700 
2.09 1.84 
18 4/6 6,700 1.45 7,875 
-- -- 
______________________________________ 
EtCy = ethylcyclohexane 
The results set forth in Tables 3 and 4 show that the reaction for the 
production of an isobutylene polymer requires a proper solution 
concentration and mixing solvent ratio. 
EXAMPLE 19 
A three-way cock was attached to a 300-ml pressure glass container. The air 
in the container was then replaced by nitrogen. Into the container were 
then charged 17.5 ml of n-octane (which had been dried by allowing to 
stand with a molecular sieve 3A overnight or longer), 70.2 ml of toluene 
(which had been dried by allowing to stand with a molecular sieve 3A 
overnight or longer) and 0.58 g (2.5 mmol) of p-DCC through a hypodermic 
syringe. Subsequently, to the three-way cock was connected a pressure 
glass tube for collecting a liquefied gas with a needle valve containing 
28 ml of an isobutylene monomer. The polymerization container was cooled 
by immersing in a dry ice/ethanol bath at -70.degree. C. Then, the 
pressure in the container was reduced by means of a vacuum pump. The 
needle valve was then opened to introduce the isobutylene monomer into the 
polymerization container through the liquefied gas collecting tube. 
Nitrogen was then introduced into the polymerization container through one 
of the ways of the three-way cock so that the pressure in the container 
was returned to normal value. Subsequently, 0.047 g (0.50 mmol) of 
2-methylpyridine was added thereto. Further, 0.83 ml (7.6 mmol) of 
titanium tetrachloride was added to the polymerization system to initiate 
polymerization. After 100 minutes of reaction, the reaction solution was 
washed with four portions of 100 ml of water. The solvent was then 
evaporated to give an isobutylene polymer. The results are shown in Table 
5. 
EXAMPLE 20 
The procedure of Example 19 was followed to produce an isobutylene polymer 
except that the amounts of n-octane and toluene added were changed to 26.3 
ml and 61.4 ml, respectively. The isobutylene polymer thus produced was 
then evaluated in the same manner as in Example 19. The results are shown 
in Table 5. 
TABLE 5 
______________________________________ 
Synthesis of polyisobutylene in n-octane/toluene solvent 
Example Octane/Toluene 
GPC NMR 
No. (solvent ratio) 
Mn Mw/Mn Mn 
______________________________________ 
19 2/8 6,600 1.41 7,900 
20 3/7 8,300 1.41 9,800 
______________________________________ 
In accordance with the present invention, it is made possible to produce an 
unsaturated group-terminated isobutylene polymer having a narrow 
distribution of molecular weight in a hydrocarbon solvent free of halogen 
compound at a high percent functionalization. Further, the solvent used 
for the reaction can be easily purified and thus can be recycled, 
realizing the reduction of the production cost. 
While the invention has been described in detail and with reference to 
specific embodiments thereof, it will be apparent to one skilled in the 
art that various changes and modifications can be made therein without 
departing from the spirit and scope thereof.