Note: Descriptions are shown in the official language in which they were submitted.
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Process for preparing high-reactivity isobutene homo- or copolymers
Description
The present invention relates to a novel process for preparing high-reactivity
isobutene
homo- or copolymers with a content of terminal vinylidene double bonds per
polyisobutene chain end of at least 50 mol%. The present invention further
relates to
novel isobutene polymers.
In contrast to so-called low-reactivity polymers, high-reactivity isobutene
homo- or
copolymers are understood to mean those polyisobutenes which comprise a high
content
of terminal ethylenic double bonds (a-double bonds), specifically in practice
usually of at
least 80 mol%, based on the individual chain ends of the polyisobutene
macromolecules.
In the context of the present application, vinylidene groups are understood to
mean those
double bonds whose position in the polyisobutene macromolecule is described by
the
general formula
polymer
i.e. the double bond is present in an a position in the polymer chain.
"Polymer" represents
the polyisobutene radical shortened by one isobutene unit. The vinylidene
groups exhibit
the highest reactivity, for example in the thermal addition onto sterically
demanding
reactants such as maleic anhydride, whereas a double bond further toward the
interior of
the macromolecules in most cases exhibits lower reactivity, if any, in
functionalization
reactions. The uses of high-reactivity polyisobutenes include use as
intermediates for
preparing additives for lubricants and fuels, as described, for example, in
DE-A 27 02 604.
Such high-reactivity polyisobutenes are obtainable, for example, by the
process of DE-A
27 02 604 by cationic polymerization of isobutene in the liquid phase in the
presence of
boron trifluoride as a catalyst. A disadvantage here is that the
polyisobutenes obtained
have a relatively high polydispersity. The polydispersity is a measure of the
molecular
weight distribution of the resulting polymer chains and corresponds to the
quotient of
weight-average molecular weight Mme, and number-average molecular weight Mn
(PDI =
Mw/Mn).
Polyisobutenes with a similarly high proportion of terminal double bonds but
with a
narrower molecular weight distribution are, for example, obtainable by the
process of EP-
A 145 235, US 5 408 018 and WO 99/64482, the polymerization being effected in
the
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presence of a deactivated catalyst, for example of a complex of boron
trifluoride with
alcohols and/or ethers.
High-reactivity polyisobutenes are also obtainable by living cationic
polymerization of
isobutene and subsequent dehydrohalogenation of the resulting polymerization
product,
for example by the process from US 5 340 881. However, such a process is
complex
since the halogen end group introduced with the living cationic polymerization
has to be
eliminated in a separate step in order to generate the double bond.
It has additionally been known for some time that the Lewis acid aluminum
trichloride can
also be used as a polymerization catalyst for isobutene, for example from High
Polymers,
volume XXIV (part 2), p. 713-733 (editor: Edward C. Leonard), J. Wiley & Sons
publishers, New York, 1971.
In the literature article "Cationic polymerization using heteropolyacid salt
catalysts" in
Topics in Catalysis Vol. 23, p. 175-181 (2003), James D. Burrington et al.
indicate that,
with aluminum trichloride as a polymerization catalyst for isobutene, only low-
reactivity
polyisobutenes with a low content of terminal vinylidene double bonds (a-
double bonds)
can be obtained. For instance, table 1 on page 178 of this literature article
cites an
example of a polyisobutene prepared with AIC13, which has a number-average
molecular
weight Mn of 1000-2000, a polydispersity M,,/Mn of 2.5-3.5 and a content of
vinylidene
isomer (a-double bond) of only 5% (in addition to 65% "tri", 5% "13" and 25%
"tetra").
In the literature article "Novel initiating system based on AIC13 etherate for
quasiliving
cationic polymerization of styrene" in Polymer Bulletin Vol. 52, p. 227-234
(2004), Sergei
V. Kostjuk et al. describe a catalyst system composed of 2-phenyl-2-propanol
and an
aluminum trichloride/di-n-butyl ether complex for polymerization of styrene.
The
polydispersities M,/Mn of the styrene polymers thus prepared are "-2.5" (see
summary)
or "-3" (see page 230).
It was an object of the present invention to provide a process for preparing
high-reactivity
isobutene homo- or copolymers with a content of terminal vinylidene double
bonds per
polyisobutene chain end of at least 80 mol% and simultaneously with a narrow
molecular
weight distribution (i.e. low polydispersities) in acceptable yields. The
catalyst system
should at the same time have sufficient activity and service life, the
handling thereof
should be unproblematic and it should not be prone to failure.
The object was achieved by a process for preparing high-reactivity isobutene
homo- or
copolymers with a content of terminal vinylidene double bonds per
polyisobutene chain
end of at least 50 mol%, which comprises polymerizing isobutene or an
isobutene-
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comprising monomer mixture in the presence of an aluminum trihalide-donor
complex
effective as a polymerization catalyst or of an alkylaluminum halide-donor
complex, said
complex comprising, as the donor, an organic compound with at least one ether
function
or a carboxylic ester function.
Isobutene homopolymers are understood in the context of the present invention
to mean
those polymers which, based on the polymer, are formed from isobutene to an
extent of
at least 98 mol%, preferably to an extent of at least 99 mol%. Accordingly,
isobutene
copolymers are understood to mean those polymers which comprise more than 2
mol%
of copolymerized monomers other than isobutene, for example linear butenes.
In the context of the present invention, the following definitions apply to
generically
defined radicals:
A C,- to C8-alkyl radical is a linear or branched alkyl radical having 1 to 8
carbon atoms.
Examples thereof are methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-butyl,
isobutyl, tert-
butyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethyl-
propyl, 1-
ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl,
2-
methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-
dimethylbutyl, 1,3-
dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-
ethylbutyl, 2-
ethylbutyl, 1,1,2-trimethyl propyl, 1,2,2-trimethyl propyl, 1 -ethyl- 1 -
methyl propyl, 1-ethyl-2-
methylpropyl, n-heptyl, n-octyl and the constitutional isomers thereof, such
as 2-
ethylhexyl. Such C,- to C8-alkyl radicals may to a small extent also comprise
heteroatoms
such as oxygen, nitrogen or halogen atoms, for example chlorine, and/or
aprotic
functional groups, for example carboxyl ester groups, cyano groups or nitro
groups.
A C,- to C2o-alkyl radical is a linear or branched alkyl radical having 1 to
20 carbon atoms.
Examples thereof are the abovementioned C,- to C8-alkyl radicals, and
additionally n-
nonyl, isononyl, n-decyl, 2-propylheptyl, n-undecyl, n-dodecyl, n-tridecyl,
isotridecyl, n-
tetradecyl, n-hexadecyl, n-octadecyl and n-eicosyl. Such C1- to C20-alkyl
radicals may to a
small extent also comprise heteroatoms such as oxygen, nitrogen or halogen
atoms, for
example chlorine, and/or aprotic functional groups, for example carboxyl ester
groups,
cyano groups or nitro groups.
A C5- to C8-cycloalkyl radical is a saturated cyclic radical which may
comprise alkyl side
chains. Examples thereof are cyclopentyl, 2- or 3-methylcyclopentyl, 2,3-, 2,4-
or 2,5-
dimethylcyclopentyl, cyclohexyl, 2-, 3- or 4-methylcyclohexyl, 2,3-, 2,4-, 2,5-
, 2,6-, 3,4-,
3,5- or 3,6-dimethylcyclohexyl, cycloheptyl, 2-, 3- or 4-methylcycloheptyl,
cyclooctyl, 2-, 3-
1 4- or 5-methylcyclooctyl. Such C5- to C8-cycloalkyl radicals may to a small
extent also
comprise heteroatoms such as oxygen, nitrogen or halogen atoms, for example
chlorine,
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and/or aprotic functional groups, for example carboxyl ester groups, cyano
groups or nitro
groups.
A C6- to C2o-aryl radical or a C6- to C12-aryl radical is preferably
optionally substituted
phenyl, optionally substituted naphthyl, optionally substituted anthracenyl or
optionally
substituted phenanthrenyl. Such aryl radicals may be a 1 to 5 aprotic
substituents or
aprotic functional groups, for example C,- to C8-alkyl, Cl- to C8-haloalkyl
such as C,- to
C8-chloroalkyl or C,- to C8-fluoroalkyl, halogens such as chlorine or
fluorine, nitro, cyano
or phenyl. Examples of such aryl radicals are phenyl, naphthyl, biphenyl,
anthracenyl,
phenanthrenyl, tolyl, nitrophenyl, chlorophenyl, dichlorophenyl,
pentafluorophenyl,
pentachlorophenyl, (trifluoromethyl)phenyl, bis(tri-fluoromethyl)phenyl,
(trichloro)methylphenyl and bis(trichIoromethyl) phenyl.
A C7- to C2o-arylalkyl radical or a C7- to C12-arylalkyl radical is preferably
optionally
substituted C,- to C4-alkylphenyl such as benzyl, o-, m- or p-methylbenzyl, 1-
or
2-phenylethyl, 1-, 2- or 3-phenylpropyl or 1-, 2-, 3- or 4-phenylbutyl,
optionally substituted
Cl- to C4-alkylnaphthyl such as naphthylmethyl, optionally substituted C,- to
C4-
alkylanthracenyl such as anthracenylmethyl, or optionally substituted C,- to
C4-alkyl-
phenanthrenyl such as phenanthrenylmethyl. Such arylalkyl radicals may bear 1
to 5
aprotic substituents or aprotic functional groups, especially on the aryl
moiety, for
example C,- to C8-alkyl, Cl- to C8-haloalkyl such as C,- to C8-chloroalkyl or
C,- to
C8-fluoroalkyl, halogen such as chlorine or fluorine, nitro or phenyl.
A suitable aluminum trihalide is especially aluminum trifluoride, aluminum
trichloride or
aluminum tribromide. A useful alkylaluminum halide is especially a mono(C,- to
C4-alkyl)aluminum dihalide or a di(C,- to C4-alkyl)aluminum monohalide, for
example
methylaluminum dichloride, ethylaluminum dichloride, dimethylaluminum chloride
or
diethylaluminum chloride. In a preferred embodiment, isobutene or an isobutene-
comprising monomer mixture is polymerized in the presence of an aluminum
trichloride-
donor complex effective as a polymerization catalyst.
If the aluminum trihalide-donor complex or alkylaluminum halide-donor complex
effective
as a polymerization catalyst comprises, as the donor, an organic compound with
at least
one ether function, compounds with at least one ether function are also
understood to
mean acetals and hemiacetals.
In a preferred embodiment of the present invention, an aluminum trihalide-
donor complex
or an alkylaluminum halide complex, especially an aluminum trichloride-donor
complex, is
used, which comprises, as the donor, a dihydrocarbyl ether of the general
formula R1-O-
R2 in which the variables R1 and R2 are each independently C,- to C2o-alkyl
radicals,
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especially Cl- to C8 alkyl radicals, C5- to C8-cycloalkyl radicals, C6- to C2o-
aryl radicals,
especially C6- to C12 aryl radicals, or C7- to C2o-arylalkyl radicals,
especially C,- to C12-
arylalkyl radicals.
5 The dihydrocarbyl ethers mentioned may be open-chain or cyclic, where the
two variables
R1 and R2 in the case of the cyclic ethers may join to form a ring, where such
rings may
also comprise two or three ether oxygen atoms. Examples of such open-chain and
cyclic
dihydrocarbyl ethers are dimethyl ether, diethyl ether, di-n-propyl ether,
diisopropyl ether,
di-n-butyl ether, di-sec-butyl ether, diisobutyl ether, di-n-pentyl ether, di-
n-hexyl ether, di-
n-heptyl ether, di-n-octyl ether, di-(2-ethylhexyl) ether, methyl n-butyl
ether, methyl sec-
butyl ether, methyl isobutyl ether, methyl tert-butyl ether, ethyl n-butyl
ether, ethyl sec-
butyl ether, ethyl isobutyl ether, n-propyl-n-butyl ether, n-propyl sec-butyl
ether, n-propyl
isobutyl ether, n-propyl tert-butyl ether, isopropyl n-butyl ether, isopropyl
sec-butyl ether,
isopropyl isobutyl ether, isopropyl tert-butyl ether, methyl n-hexyl ether,
methyl n-octyl
ether, methyl 2-ethylhexyl ether, ethyl n-hexyl ether, ethyl n-octyl ether,
ethyl 2-ethylhexyl
ether, n-butyl n-octyl ether, n-butyl 2-ethylhexyl ether, tetrahydrofuran,
tetrahydropyran,
1,2-, 1,3- and 1,4-dioxane, dicyclohexyl ether, diphenyl ether, ditolyl ether,
dixylyl ether
and dibenzyl ether. Among the dihydrocarbyl ethers mentioned, di-n-butyl ether
and
diphenyl ether have been found to be particularly advantageous as donors for
the
aluminum trihalide-donor complexes or the alkylaluminum halide complexes,
especially
the aluminum trichloride-donor complexes.
In a further preferred embodiment of the present invention, as an alternative,
an
aluminum trihalide-donor complex or an alkylaluminum halide complex,
especially an
aluminum trichloride-donor complex, is used, which comprises, as the donor, a
hydrocarbyl carboxylate of the general formula R3-0OOR4 in which the variables
R3 and
R4 are each independently C,- to C2o-alkyl radicals, especially C,- to C8
alkyl radicals, C5-
to C8-cycloalkyl radicals, C6- to C2o-aryl radicals, especially C6- to C12
aryl radicals, or 07-
to C2o-arylalkyl radicals, especially C7- to C12-arylalkyl radicals.
Examples of the hydrocarbyl carboxylates mentioned are methyl formate, ethyl
formate,
n-propyl formate, isopropyl formate, n-butyl formate, sec-butyl formate,
isobutyl formate,
tert-butyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl
acetate, n-
butyl acetate, sec-butyl acetate, isobutyl acetate, tert-butyl acetate, methyl
propionate,
ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl
propionate, sec-butyl
propionate, isobutyl propionate, tert-butyl propionate, methyl butyrate, ethyl
butyrate, n-
propyl butyrate, isopropyl butyrate, n-butyl butyrate, sec-butyl butyrate,
isobutyl butyrate,
tert-butyl butyrate, methyl cyclohexanecarboxylate, ethyl
cyclohexanecarboxylate, n-
propyl cyclohexanecarboxylate, isopropyl cyclohexanecarboxylate, n-butyl
cyclohexanecarboxylate, sec-butyl cyclohexanecarboxylate, isobutyl
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cyclohexanecarboxylate, tert-butyl cyclohexanecarboxylate, methyl benzoate,
ethyl
benzoate, n-propyl benzoate, isopropyl benzoate, n-butyl benzoate, sec-butyl
benzoate,
isobutyl benzoate, tert-butyl benzoate, methyl phenylacetate, ethyl
phenylacetate, n-
propyl phenylacetate, isopropyl phenylacetate, n-butyl phenylacetate, sec-
butyl
phenylacetate, isobutyl phenylacetate and tert-butyl phenylacetate. Among the
hydrocarbyl carboxylates mentioned, ethyl acetate has been found to be
particularly
advantageous as a donor for the aluminum trihalide-donor complexes or the
alkylaluminum halide complexes, especially the aluminum trichloride-donor
complexes.
In addition, particularly advantageous dihydrocarbyl ethers and hydrocarbyl
carboxylates
as donors for the aluminum trihalide-donor complexes or the alkylaluminum
halide
complexes, especially the aluminum trichloride-donor complexes, have been
found to be
those in which the donor compound has a total carbon number of 3 to 16,
preferably of 4
to 16, especially of 4 to 12, in particular of 4 to 8. In the specific case of
the dihydrocarbyl
ethers, preference is given in particular to those having a total of 6 to 14
and especially 8
to 12 carbon atoms. In the specific case of the hydrocarbyl carboxylates,
preference is
given in particular to those having a total of 3 to 10 and especially 4 to 6
carbon atoms.
The molar ratio of the donor compounds mentioned to the aluminum trihalide or
to the
alkylaluminum halide, especially to the aluminum trichloride, in the donor
complex
generally varies within the range from 0.3:1 to 1.5:1, especially from 0.5:1
to 1.2:1, in
particular 0.7:1 to 1.1:1; in most cases it is 1:1. However, it is also
possible to work with a
greater excess of the donor compounds, often up to a 10-fold and especially 3-
fold molar
excess; the excess amount of donor compounds then acts additionally as a
solvent or
diluent.
Typically, the aluminum trihalide-donor complex or the alkylaluminum halide
complex,
especially the aluminum trichloride-donor complex, is prepared separately
prior to the
polymerization from the aluminum trihalide or the alkylaluminum halide,
especially from
anhydrous aluminum trichloride, and the donor compound, and is then - usually
dissolved
in an inert solvent such as a halogenated hydrocarbon, for example
dichloromethane -
added to the polymerization medium. However, the complex can also be prepared
in situ
prior to the polymerization.
In a preferred embodiment of the present invention, the polymerization is
performed with
additional use of a mono- or polyfunctional, especially mono-, di- or
trifunctional, initiator
which is selected from organic hydroxyl compounds, organic halogen compounds
and
water. It is also possible to use mixtures of the initiators mentioned, for
example mixtures
of two or more organic hydroxyl compounds, mixtures of two or more organic
halogen
compounds, mixtures of one or more organic hydroxyl compounds and one or more
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organic halogen compounds, mixtures of one or more organic hydroxyl compounds
and
water, or mixtures of one or more organic halogen compounds and water. The
initiator
may be mono-, di- or polyfunctional, i.e. one, two or more hydroxyl groups or
halogen
atoms, which start the polymerization reaction, may be present in the
initiator molecule. In
the case of di- or polyfunctional initiators, telechelic isobutene polymers
with two or more,
especially two or three, polyisobutene chain ends are typically obtained.
Organic hydroxyl compounds which have only one hydroxyl group in the molecule
and
are suitable as monofunctional initiators include especially alcohols and
phenols, in
particular those of the general formula R5-OH, in which R5 denotes Cl- to C2o-
alkyl
radicals, especially Cl- to C8-alkyl radicals, C5- to C8-cycloalkyl radicals,
C6- to C2o-aryl
radicals, especially C6- to C12-aryl radicals, or C7- to C2o-arylalkyl
radicals, especially C7-
to C12-arylalkyl radicals. In addition, the R5 radicals may also comprise
mixtures of the
abovementioned structures and/or have other functional groups than those
already
mentioned, for example a keto function, a nitroxide or a carboxyl group,
and/or
heterocyclic structural elements.
Typical examples of such organic monohydroxyl compounds are methanol, ethanol,
n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol, n-
pentanol,
n-hexanol, n-heptanol, n-octanol, 2-ethylhexanol, cyclohexanol, phenol, p-
methoxy-
phenol, o-, m- and p-cresol, benzyl alcohol, p-methoxybenzyl alcohol, 1- and 2-
phenyl-
ethanol, 1- and 2-(p-methoxyphenyl)ethanol, 1-, 2- and 3-phenyl-1-propanol, 1-
, 2- and 3-
(p-methoxyphenyl)- 1 -propanol, 1- and 2-phenyl-2-propanol, 1- and 2-(p-
methoxyphenyl)-
2-propanol, 1-, 2-, 3- and 4-phenyl-1-butanol, 1-, 2-, 3- and 4-(p-
methoxyphenyl)-1-
butanol, 1-, 2-, 3- and 4-phenyl-2-butanol, 1-, 2-, 3- and 4-(p-methoxyphenyl)-
2-butanol,
9-methyl-9H-fluoren-9-ol, 1,1-diphenylethanol, 1,1-diphenyl-2-propyn-1-ol, 1,1-
diphenylpropanol, 4-(1-hydroxy-1-phenylethyl)benzonitrile,
cyclopropyldiphenylmethanol,
1 -hydroxy-1, 1 -diphenylpropan-2-one, benzilic acid, 9-phenyl-9-fluorenol,
triphenylmethanol, diphenyl(4-pyridinyl)methanol, alpha,alpha-diphenyl-2-
pyridinemethanol, 4-methoxytrityl alcohol (especially polymer-bound as a solid
phase),
alpha-tert-butyl-4-chloro-4'-m ethylbenzhydrol, cyclohexyldiphenyl methanol,
alpha-(p-
tolyl)-benzhydrol, 1,1,2-triphenylethanol, alpha, alpha-diphenyl-2-
pyridineethanol,
alpha,alpha-4-pyridylbenzhydrol N-oxide, 2-fluorotriphenylmethanol,
triphenylpropargyl
alcohol, 4-[(diphenyl)hydroxymethyl]benzonitrile, 1-(2,6-dimethoxyphenyl)-2-
methyl- 1-
phenyl-1-propanol, 1,1,2-triphenylpropan-1-ol and p-anisaldehyde carbinol.
Organic hydroxyl compounds which have two hydroxyl groups in the molecule and
are
suitable as bifunctional initiators are especially dihydric alcohols or diols
having a total
carbon number of 2 to 30, especially of 3 to 24, in particular of 4 to 20, and
bisphenols
having a total carbon number of 6 to 30, especially of 8 to 24, in particular
of 10 to 20, for
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example ethylene glycol, 1,2- and 1,3-propylene glycol, 1,4-butylene glycol,
1,6-hexylene
glycol, 1,2-, 1,3- or 1,4-bis(1-hydroxy-1-methylethyl)benzene (o-, m- or p-
dicumyl
alcohol), bisphenol A, 9,1 0-di-hydro-9, 1 0-dimethyl-9,1 0-anthracenediol,
1,1-diphenyl butane- l,4-diol, 2-hydroxytriphenylcarbinol and 9-[2- (hyd roxym
ethyl) p henyl]-
9-fluorenol.
Organic halogen compounds which have one halogen atom in the molecule and are
suitable as monofunctional initiators are in particular compounds of the
general formula
R6-Hal in which Hal is a halogen atom selected from fluorine, iodine and
especially
chlorine and bromine, and R6 denotes C1- to C2o-alkyl radicals, especially C1-
to C8-alkyl
radicals, C5- to C8-cycloalkyl radicals or C7- to C2o-arylalkyl radicals,
especially C7- to C12-
arylalkyl radicals. In addition, the R6 radicals may also comprise mixtures of
the
abovementioned structures and/or have other functional groups than those
already
mentioned, for example a keto function, a nitroxide or a carboxyl group,
and/or
heterocyclic structural elements.
Typical examples of such monohalogen compounds are methyl chloride, methyl
bromide,
ethyl chloride, ethyl bromide, 1-chloropropane, 1-bromopropane, 2-
chloropropane, 2-
bromopropane, 1-chlorobutane, 1-bromobutane, sec-butyl chloride, sec-butyl
bromide,
isobutyl chloride, isobutyl bromide, tert-butyl chloride, tert-butyl bromide,
1-chloropentane,
1-bromopentane, 1-chlorohexane, 1-bromohexane, 1-chloroheptane, 1-
bromoheptane, 1-
chlorooctane, 1-bromooctane, 1-chloro-2-ethylhexane, 1-bromo-2-ethylhexane,
cyclohexyl chloride, cyclohexyl bromide, benzyl chloride, benzyl bromide, 1-
phenyl-1-
chloroethane, 1-phenyl-1-bromoethane, 1-phenyl-2-chloroethane, 1-phenyl-2-
bromoethane, 1-phenyl-1-chloropropane, 1-phenyl-1-bromopropane, 1-phenyl-2-
chloropropane, 1-phenyl-2-bromopropane, 2-phenyl-2-chloropropane, 2-phenyl-2-
bromopropane, 1-phenyl-3-chloropropane, 1-phenyl-3-bromopropane, 1-phenyl-1-
chlorobutane, 1-phenyl-1-bromobutane, 1-phenyl-2-chlorobutane, 1-phenyl-2-
bromobutane, 1-phenyl-3-chlorobutane, 1-phenyl-3-bromobutane, 1-phenyl-4-
chlorobutane, 1-phenyl-4-bromobutane, 2-phenyl-1-chlorobutane, 2-phenyl-1-
bromobutane, 2-phenyl-2-chlorobutane, 2-phenyl-2-bromobutane, 2-phenyl-3-
chlorobutane, 2-phenyl-3-bromobutane, 2-phenyl-4-chlorobutane and 2-phenyl-4-
bromobutane.
Organic halogen compounds which have two halogen atoms in the molecule and are
suitable as difunctional initiators are, for example, 1,3-bis(1-bromo-1-
methylethyl)-
benzene, 1,3-bis(2-chloro-2-propyl)benzene (1,3-dicumyl chloride) and 1,4-
bis(2-chloro-2-
propyl)benzene (1,4-dicumyl chloride).
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The initiator is more preferably selected from organic hydroxyl compounds in
which one
or more hydroxyl groups are each bonded to an spa-hybridized carbon atom,
organic
halogen compounds, in which one or more halogen atoms are each bonded to an
sp3-
hybridized carbon atom, and water. Among these, preference is given in
particular to an
initiator selected from organic hydroxyl compounds in which one or more
hydroxyl groups
are each bonded to an spa-hybridized carbon atom.
In the case of the organic halogen compounds as initiators, particular
preference is
further given to those in which the one or more halogen atoms are each bonded
to a
secondary or especially to a tertiary spa-hybridized carbon atom.
Preference is given in particular to initiators which may bear, on such an spa-
hydridized
carbon atom, in addition to the hydroxyl group, the R5, R6 and R7 radicals,
which are each
independently hydrogen, Cl- to C2o-alkyl, C5- to Cs-cycloalkyl, C6- to C2o-
aryl, C7- to C20-
alkylaryl or phenyl, where any aromatic ring may also bear one or more,
preferably one or
two, Cl- to C4-alkyl, Cl- to C4-alkoxy, Cl- to C4-hydroxyalkyl or C,- to C4-
haloalkyl radicals
as substituents, where not more than one of the variables R5, R6 and R7 is
hydrogen and
at least one of the variables R5, R6 and R7 is phenyl which may also bear one
or more,
preferably one or two, Cl- to C4-alkyl, Cl- to C4-alkoxy, C,- to C4-
hydroxyalkyl or C,- to C4-
haloalkyl radicals as substituents.
For the present invention, very particular preference is given to initiators
selected from
water, methanol, ethanol, 1-phenylethanol, 1-(p-methoxyphenyl)ethanol, n-
propanol,
isopropanol, 2-phenyl-2-propanol (cumene), n-butanol, isobutanol, sec.-
butanol, tert-
butanol, 1-phenyl-1-chloroethane, 2-phenyl-2-chloropropane (cumyl chloride),
tert-butyl
chloride and 1,3- or 1,4-bis(1-hydroxy-1-m ethyl ethyl) benzene. Among these,
preference
is given in particular to initiators selected from water, methanol, ethanol, 1-
phenylethanol,
1-(p-methoxyphenyl)ethanol, n-propanol, isopropanol, 2-phenyl-2-propanol
(cumene), n-
butanol, isobutanol, sec.-butanol, tert-butanol, 1-phenyl-1-chloroethane and
1,3- or 1,4-
bis(1-hydroxy-1-methylethyl)benzene.
The molar ratio of the initiators mentioned to the isobutene monomer used in
the case of
homopolymerization of isobutene, or to the total amount of the polymerizable
monomers
used in the case of copolymerization of isobutene, based on each individual
functional
site of the initiator, is generally 0.0005:1 to 0.1:1, especially 0.001:1 to
0.075:1, in
particular 0.0025:1 to 0.05:1. When water is used as the sole initiator or in
combination
with organic hydroxyl compounds and/or organic halogen compounds as further
initiators,
the molar ratio of water to the isobutene monomer used in the case of
homopolymerization of isobutene, or to the total amount of the polymerizable
monomers
CA 02789843 2012-08-14
used in the case of copolymerization of isobutene, is especially 0.0001:1 to
0.1:1, in
particular 0.0002:1 to 0.05:1.
A proportion of the initiator molecules added as organic hydroxyl or halogen
compounds
5 is incorporated into the polymer chains. The proportion (Ieff) of polymer
chains which are
started by such an incorporated organic initiator molecule may be up to 100%,
and is
generally 5 to 90%. The remaining polymer chains arise either from water
originating from
traces of moisture as an initiator molecule, or from chain transfer reactions.
10 In a further preferred embodiment of the present invention, the
polymerization is
performed in the presence of 0.01 to 10 mmol, especially of 0.05 to 5.0 mmol,
in
particular of 0.1 to 1.0 mmol, based in each case on 1 mol of isobutene
monomer used in
the case of homopolymerization of isobutene, or on 1 mol of the total amount
of the
polymerizable monomers used in the case of copolymerization of isobutene, of a
nitrogen-containing basic compound.
Such a nitrogen-containing basic compound used may be an aliphatic,
cycloaliphatic or
aromatic amine of the general formula R7-NR8R9, or else ammonia, in which the
variables
R7, R8 and R9 are each independently hydrogen, Cl- to C2o-alkyl radicals,
especially C,- to
C8-alkyl radicals, C5- to C8-cycloalkyl radicals, C6- to C2o-aryl radicals,
especially C6- to
C12-aryl radicals, or C7- to C2o-arylalkyl radicals, especially C7- to C12-
arylalkyl radicals.
When none of these variables is hydrogen, the amine is a tertiary amine. When
one of
these variables is hydrogen, the amine is a secondary amine. When two of these
variables is hydrogen, the amine is a primary amine. When all these variables
are
hydrogen, the amine is ammonia.
Typical examples of such amines of the general formula R7-NR8R9 are
methylamine,
ethylamine, n-propylamine, isopropylamine, n-butylamine, tert-butylamine, sec-
butyl-
amine, isobutylamine, tert-amylamine, n-hexylamine, n-heptylamine, n-
octylamine,
2-ethylhexylamine, cyclopentylamine, cyclohexylamine, aniline, dimethylamine,
diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, di-tert-
butylamine, di-
sec-butylamine, diisobutylamine, di-tert-amylamine, di-n-hexylamine, di-n-
heptylamine, di-
n-octylamine, di-(2-ethylhexyl)amine, dicyclopentylamine, dicyclohexylamine,
diphenylamine, trimethylamine, triethylamine, tri-n-propylamine, tri-
isopropylamine, tri-n-
butylamine, tri-tert-butylamine, tri-sec-butylamine, tri-isobutylamine, tri-
tert-amylamine, tri-
n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-(2-ethylhexyl)amine,
tricyclopentylamine, tricyclohexylamine, triphenylamine, dimethylethylamine,
methyl-n-
butylamine, N-methyl-N-phenylamine, N,N-dimethyl-N-phenylamine, N-methyl-N,N-
diphenylamine or N-methyl-N-ethyl-N-n-butylamine.
CA 02789843 2012-08-14
11
In addition, such a nitrogen-containing basic compound used may also be a
compound
having a plurality of, especially having two or three, nitrogen atoms and
having 2 to 20
carbon atoms, where these nitrogens may each independently bear hydrogen atoms
or
aliphatic, cycloaliphatic or aromatic substituents. Examples of such
polyamines are
1,2-ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine,
diethylenetriamine, N-
methyl-l,2-ethylenediamine, N,N-dimethyl-l,2-ethylenediamine, N,N'-dimethyl-
1,2-
ethylenediamine or N,N-dimethyl-1,3-propylenediamine.
However, a suitable nitrogen-containing basic compound of this kind is
especially a
saturated, partly unsaturated or unsaturated nitrogen-containing five-membered
or six-
membered heterocyclic ring which comprises one, two or three ring nitrogen
atoms and
may have one or two further ring heteroatoms from the group of oxygen and
sulfur and/or
hydrocarbyl radicals, especially Cl- to C4-alkyl radicals and/or phenyl,
and/or functional
groups or heteroatoms as substituents, especially fluorine, chlorine, bromine,
nitro and/or
cyano, for example pyrrolidine, pyrrole, imidazole, 1,2,3- or 1,2,4-triazole,
oxazole,
thiazole, piperidine, pyrazane, pyrazole, pyridazine, pyrimidine, pyrazine,
1,2,3-, 1,2,4- or
1,2,5-triazine, 1,2,5-oxathiazine, 2H-1,3,5-thiadiazine or morpholine.
However, a very particularly suitable nitrogen-containing basic compound of
this kind is
pyridine or a derivative of pyridine (especially a mono-, di- or tri-C,- to C4-
alkyl-substituted
pyridine) such as 2-, 3-, or 4-methylpyridine (picolines), 2,3-, 2,4-, 2,5-,
2,6-, 3,4-, 3,5- or
3,6-dimethylpyridine (lutidines), 2,4,6-timethylpyridine (collidine), 2-, 3,-
or 4-tert-
butylpyridine, 2-tert-butyl-6-methylpyridine, 2,4-, 2,5-, 2,6- or 3,5-di-tert-
butylpyridine or
else 2-, 3,- or 4-phenylpyridine.
It is possible to use a single nitrogen-containing basic compound or mixtures
of such
nitrogen-containing basic compounds.
For the use of isobutene or of an isobutene-comprising monomer mixture as the
monomer to be polymerized, suitable isobutene sources are both pure isobutene
and
isobutenic C4 hydrocarbon streams, for example C4 raffinates, especially
"raffinate 1", C4
cuts from isobutane dehydrogenation, C4 cuts from steam crackers and from FCC
crackers (fluid catalyzed cracking), provided that they have been
substantially freed of
1,3-butadiene present therein. A C4 hydrocarbon stream from an FCC refinery
unit is also
known as "b/b" stream. Further suitable isobutenic C4 hydrocarbon streams are,
for
example, the product stream of a propylene-isobutane cooxidation or the
product stream
from a metathesis unit, which are generally used after customary purification
and/or
concentration. Suitable C4 hydrocarbon streams generally comprise less than
500 ppm,
preferably less than 200 ppm, of butadiene. The presence of 1-butene and of
cis- and
trans-2-butene is substantially uncritical. Typically, the isobutene
concentration in the C4
CA 02789843 2012-08-14
12
hydrocarbon streams mentioned is in the range from 40 to 60% by weight. For
instance,
raffinate I generally consists essentially of 30 to 50% by weight of
isobutene, 10 to 50%
by weight of 1-butene, 10 to 40% by weight of cis- and trans-2-butene, and 2
to 35% by
weight of butanes; in the polymerization process according to the invention,
the
unbranched butenes in the raffinate 1 generally behave virtually inertly, and
only the
isobutene is polymerized.
In a preferred embodiment, the monomer source used for the polymerization is a
technical C4 hydrocarbon stream with an isobutene content of 1 to 100% by
weight,
especially of 1 to 99% by weight, in particular of 1 to 90% by weight, more
preferably of
30 to 60% by weight, especially a raffinate 1 stream, a b/b stream from an FCC
refinery
unit, a product stream from a propylene-isobutane cooxidation or a product
stream from a
metathesis unit.
Especially when a raffinate 1 stream is used as the isobutene source, the use
of water as
the sole initiator or as a further initiator has been found to be useful, in
particular when
polymerization is effected at temperatures of -20 C to +30 C, especially of 0
C to +20 C.
At temperatures of -20 C to +30 C, especially of 0 C to +20 C, when a
raffinate 1 stream
is used as the isobutene source, it is, however, also possible to dispense
with the use of
an initiator.
The isobutenic monomer mixture mentioned may comprise small amounts of
contaminants such as water, carboxylic acids or mineral acids, without there
being any
critical yield or selectivity losses. It is appropriate to prevent enrichment
of these
impurities by removing such harmful substances from the isobutenic monomer
mixture,
for example by adsorption on solid adsorbents such as activated carbon,
molecular
sieves or ion exchangers.
It is also possible to convert monomer mixtures of isobutene or of the
isobutenic
hydrocarbon mixture with olefinically unsaturated monomers copolymerizable
with
isobutene. When monomer mixtures of isobutene are to be copolymerized with
suitable
comonomers, the monomer mixture preferably comprises at least 5% by weight,
more
preferably at least 10% by weight and especially at least 20% by weight of
isobutene, and
preferably at most 95% by weight, more preferably at most 90% by weight and
especially
at most 80% by weight of comonomers.
Useful copolymerizable monomers include: vinylaromatics such as styrene and
a-methylstyrene, Cl- to C4-a I kyl styrenes such as 2-, 3- and 4-
methylstyrene, and 4-tert-
butylstyrene, halostyrenes such as 2-, 3- or 4-chlorostyrene,
CA 02789843 2012-08-14
13
and isoolefins having 5 to 10 carbon atoms, such as 2-methylbutene-1, 2-m
ethylpentene-
1, 2-methylhexene-1, 2-ethylpentene-1, 2-ethylhexene-1 and 2-propylheptene-1.
Further
useful comonomers include olefins which have a silyl group, such as 1-tri-
methoxysilylethene, 1-(trimethoxysilyl)propene, 1-(trimethoxysilyl)-2-methyl
propene-2, 1-
[tri(methoxyethoxy)silyl]ethene, 1-[tri(methoxyethoxy)silyl]propene, and
1-[tri(methoxyethoxy)silyl]-2-methyl propene-2. In addition - depending on the
polymerization conditions - useful comonomers also include isoprene, 1-butene
and cis-
and trans-2-butene.
When the process according to the invention is to be used to prepare
copolymers, the
process can be configured so as to preferentially form random polymers or to
preferentially form block copolymers. To prepare block copolymers, for
example, the
different monomers can be supplied successively to the polymerization
reaction, in which
case the second comonomer is especially not added until the first comonomer is
already
at least partly polymerized. In this manner, diblock, triblock and higher
block copolymers
are obtainable, which, according to the sequence of monomer addition, have a
block of
one or the other comonomer as a terminal block. In some cases, however, block
copolymers also form when all comonomers are supplied to the polymerization
reaction
simultaneously, but one of them polymerizes significantly more rapidly than
the other(s).
This is the case especially when isobutene and a vinylaromatic compound,
especially
styrene, are copolymerized in the process according to the invention. This
preferably
forms block copolymers with a terminal polystyrene block. This is attributable
to the fact
that the vinylaromatic compound, especially styrene, polymerizes significantly
more
slowly than isobutene.
The polymerization can be effected either continuously or batchwise.
Continuous
processes can be performed in analogy to known prior art processes for
continuous
polymerization of isobutene in the presence of boron trifluoride-based
catalysts in the
liquid phase.
The process according to the invention is suitable either for performance at
low
temperatures, e.g. at -90 C to 0 C, or at higher temperatures, i.e. at at
least 0 C, e.g. at
0 C to +30 C or at 0 C to +50 C. The polymerization in the process according
to the
invention is, however, preferably performed at relatively low temperatures,
generally at
-70 C to -10 C, especially at -60 C to -15 C.
When the polymerization in the process according to the invention is effected
at or above
the boiling temperature of the monomer or monomer mixture to be polymerized,
it is
preferably performed in pressure vessels, for example in autoclaves or in
pressure
reactors.
CA 02789843 2012-08-14
14
The polymerization in the process according to the invention is preferably
performed in
the presence of an inert diluent. The inert diluent used should be suitable
for reducing the
increase in the viscosity of the reaction solution which generally occurs
during the
polymerization reaction to such an extent that the removal of the heat of
reaction which
evolves can be ensured. Suitable diluents are those solvents or solvent
mixtures which
are inert toward the reagents used. Suitable diluents are, for example,
aliphatic
hydrocarbons such as n-butane, n-pentane, n-hexane, n-heptane, n-octane and
isooctane, cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane,
aromatic
hydrocarbons such as benzene, toluene and the xylenes, and halogenated
hydrocarbons,
especially halogenated aliphatic hydrocarbons, such as methyl chloride,
dichloromethane
and trichloromethane (chloroform), 1,1-dichloroethane, 1,2-dichloroethane,
trichloroethane and 1-chlorobutane, and also halogenated aromatic hydrocarbons
and
alkylaromatics halogenated in the alkyl side chains, such as chlorobenzene,
monofluoromethylbenzene, difluoromethylbenzene and trifluoromethylbenzene, and
mixtures of the aforementioned diluents. The diluents used, or the
constituents used in
the solvent mixtures mentioned, are also the inert components of isobutenic C4
hydrocarbon streams.
The inventive polymerization is preferably performed in a halogenated
hydrocarbon,
especially in a halogenated aliphatic hydrocarbon, or in a mixture of
halogenated
hydrocarbons, especially of halogenated aliphatic hydrocarbons, or in a
mixture of at least
one halogenated hydrocarbon, especially a halogenated aliphatic hydrocarbon,
and at
least one aliphatic, cycloaliphatic or aromatic hydrocarbon as an inert
diluent, for example
a mixture of dichloromethane and n-hexane, typically in a volume ratio of
10:90 to 90:10,
especially of 50:50 to 85:15. Prior to use, the diluents are preferably freed
of impurities
such as water, carboxylic acids or mineral acids, for example by adsorption on
solid
adsorbents such as activated carbon, molecular sieves or ion exchangers.
In a further preferred embodiment, the inventive polymerization is performed
in halogen-
free aliphatic or especially halogen-free aromatic hydrocarbons, especially
toluene. For
this embodiment, water in combination with the organic hydroxyl compounds
mentioned
and/or the organic halogen compounds mentioned, or especially as the sole
initiator,
have been found to be particularly advantageous.
The polymerization in the process according to the invention is preferably
performed
under substantially aprotic and especially under substantially anhydrous
reaction
conditions. Substantially aprotic and substantially anhydrous reaction
conditions are
understood to mean that, respectively, the content of protic impurities and
the water
content in the reaction mixture are less than 50 ppm and especially less than
5 ppm. In
general, the feedstocks will therefore be dried before use by physical and/or
chemical
CA 02789843 2012-08-14
measures. More particularly, it has been found to be useful to admix the
aliphatic or
cycloaliphatic hydrocarbons used as solvents, after customary prepurification
and
predrying with an organometallic compound, for example an organolithium,
organomagnesium or organoaluminum compound, in an amount which is sufficient
to
5 substantially remove the water traces from the solvent. The solvent thus
treated is then
preferably condensed directly into the reaction vessel. It is also possible to
proceed in a
similar manner with the monomers to be polymerized, especially with isobutene
or with
the isobutenic mixtures. Drying with other customary desiccants such as
molecular sieves
or predried oxides such as aluminum oxide, silicon dioxide, calcium oxide or
barium oxide
10 is also suitable. The halogenated solvents for which drying with metals
such as sodium or
potassium or with metal alkyls is not an option are freed of water or water
traces with
desiccants suitable for that purpose, for example with calcium chloride,
phosphorus
pentoxide or molecular sieves. It is also possible in an analogous manner to
dry those
feedstocks for which treatment with metal alkyls is likewise not an option,
for example
15 vinylaromatic compounds. Even if some or all of the initiator used is
water, residual
moisture should preferably be very substantially or completely removed from
solvents and
monomers by drying prior to reaction, in order to be able to use the water
initiator in a
controlled, specified amount, as a result of which greater process control and
reproducibility of the results are obtained.
The polymerization of the isobutene or of the isobutenic starting material
generally
proceeds spontaneously when the aluminum trihalide-donor complex or the
alkylaluminum halide complex, especially the aluminum trichloride-donor
complex, is
contacted with the isobutene or the isobutenic monomer mixture at the desired
reaction
temperature. The procedure here may be to initially charge the monomers,
optionally in
the diluent, to bring it to reaction temperature and then to add the aluminum
trihalide-
donor complex or the alkylaluminum halide complex, especially the aluminum
trichloride-
donor complex. The procedure may also be to initially charge the aluminum
trihalide-
donor complex or the alkylaluminum halide complex, especially the aluminum
trichloride-
donor complex, optionally in the diluent, and then to add the monomers. In
that case, the
start of polymerization is considered to be that time at which all reactants
are present in
the reaction vessel.
To prepare isobutene copolymers, the procedure may be to initially charge the
monomers, optionally in the diluent, and then to add the aluminum trihalide-
donor
complex or the alkylaluminum halide complex, especially the aluminum
trichloride-donor
complex. The reaction temperature can be established before or after the
addition of the
aluminum trihalide-donor complex or the alkylaluminum halide complex,
especially of the
aluminum trichloride-donor complex. The procedure may also be first to
initially charge
only one of the monomers, optionally in the diluent, then to add the aluminum
trihalide-
CA 02789843 2012-08-14
16
donor complex or the alkylaluminum halide complex, especially the aluminum
trichloride-
donor complex, and to add the further monomer(s) only after a certain time,
for example
when at least 60%, at least 80% or at least 90% of the monomer has been
converted.
Alternatively, the aluminum trihalide-donor complex or the alkylaluminum
halide complex,
especially the aluminum trichloride-donor complex, can be initially charged,
optionally in
the diluent, then the monomers can be added simultaneously or successively,
and then
the desired reaction temperature can be established. In that case, the start
of
polymerization is considered to be that time at which the aluminum trihalide-
donor
complex or the alkylaluminum halide complex, especially the aluminum
trichloride-donor
complex, and at least one of the monomers are present in the reaction vessel.
In addition to the batchwise procedure described here, the polymerization in
the process
according to the invention can also be configured as a continuous process. In
this case,
the feedstocks, i.e. the monomer(s) to be polymerized, optionally the diluent
and
optionally the aluminum trihalide-donor complex or the alkylaluminum halide
complex,
especially the aluminum trichloride-donor complex, are supplied continuously
to the
polymerization reaction, and reaction product is withdrawn continuously, such
that more
or less steady-state polymerization conditions are established in the reactor.
The
monomer(s) to be polymerized can be supplied as such, diluted with a diluent
or solvent,
or as a monomer-containing hydrocarbon stream.
The aluminum trihalide-donor complex effective as a polymerization catalyst or
the
alkylaluminum halide complex, especially the aluminum trichloride-donor
complex, is
generally present in dissolved, dispersed or suspended form in the
polymerization
medium. Supporting of the aluminum trihalide-donor complex or of the
alkylaluminum
halide complex, especially of the aluminum trichloride-donor complex, on
customary
support materials is also possible. Suitable reactor types for the
polymerization process of
the present invention are typically stirred tank reactors, loop reactors and
tubular
reactors, but also fluidized bed reactors, stirred tank reactors with or
without solvent, fluid
bed reactors, continuous fixed bed reactors and batchwise fixed bed reactors
(batchwise
mode).
In the process according to the invention, the aluminum trihalide-donor
complex effective
as a polymerization catalyst or the alkylaluminum halide complex, especially
the
aluminum trichloride-donor complex, is generally used in such an amount that
the molar
ratio of aluminum in the aluminum trihalide-donor complex or alkylaluminum
halide
complex, especially in the aluminum trichloride-donor complex, to isobutene in
the case
of homopolymerization of isobutene, or to the total amount of the
polymerizable
monomers used in the case of copolymerization of isobutene, is in the range
from 1:5 to
CA 02789843 2012-08-14
17
1:5000, preferably from 1:10 to 1:5000, especially 1:15 to 1:1000, in
particular 1:20 to
1:250.
To stop the reaction, the reaction mixture is preferably deactivated, for
example by adding
a protic compound, especially by adding water, alcohols such as methanol,
ethanol, n-
propanol and isopropanol or mixtures thereof with water, or by adding an
aqueous base,
for example an aqueous solution of an alkali metal or alkaline earth metal
hydroxide such
as sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium
hydroxide,
an alkali metal or alkaline earth metal carbonate such as sodium, potassium,
magnesium
or calcium carbonate, or an alkali metal or alkaline earth metal
hydrogencarbonate such
as sodium, potassium, magnesium or calcium hydrogencarbonate.
The process according to the invention serves to prepare high-reactivity
isobutene homo-
or copolymers with a content of terminal vinylidene double bonds (a-double
bonds) per
polyisobutene chain end of at least 50 mol%, preferably of at least 60 mol%,
preferably of
at least 70 mol%, preferably of at least 80 mol%, preferably of at least 85
mol%, more
preferably of at least 90 mol%, more preferably of more than 91 mol% and
especially of at
least 95 mol%, for example of virtually 100 mol%. More particularly, it also
serves to
prepare high-reactivity isobutene copolymers which are formed from isobutene
and at
least one vinylaromatic monomer, especially styrene, and have a content of
terminal
vinylidene double bonds ((x-double bonds) per polyisobutene chain end of at
least
50 mol%, preferably of at least 60 mol%, preferably of at least 70 mol%,
preferably of at
least 80 mol%, preferably of at least 80 mol%, preferably of at least 85 mol%,
more
preferably of at least 90 mol%, more preferably of more than 91 mol% and
especially of at
least 95 mol%, for example of virtually 100 mol%. To prepare such copolymers
of
isobutene and at least one vinylaromatic monomer, especially styrene,
isobutene or an
isobutenic hydrocarbon cut is copolymerized with the at least one
vinylaromatic monomer
in a weight ratio of isobutene to vinylaromatic of 5:95 to 95:5, especially of
30:70 to 70:30.
The high-reactivity isobutene homo- or copolymers prepared by the process
according to
the invention and specifically the isobutene homopolymers preferably have a
polydispersity (PDI = MW/Mn) of 1.05 to less than 3.5, preferably of 1.05 to
less than 3.0,
preferably of 1.05 to less than 2.5, preferably of 1.05 to 2.3, more
preferably of 1.05 to 2.0
and especially of 1.1 to 1.85. Typical PDI values in the case of an optimal
process regime
are 1.2 to 1.7.
The high-reactivity isobutene homo- or copolymers prepared by the process
according to
the invention preferably possess a number-average molecular weight Mn
(determined by
gel permeation chromatography) of preferably 500 to 250 000, more preferably
of 500 to
100 000, even more preferably of 500 to 25 000 and especially of 500 to 5000.
Isobutene
CA 02789843 2012-08-14
18
homopolymers even more preferably possess a number-average molecular weight M,
of
500 to 10 000 and especially of 500 to 5000, for example of about 1000 or of
about 2300.
Some of the isobutene polymers which have terminal vinylidene double bonds and
also
comprise incorporated initiator molecules and occur as the predominant
proportion in the
isobutene homopolymers prepared in accordance with the invention are novel
compounds. The present invention therefore also provides isobutene polymers of
the
general formula I
R10
R11
n
R 12 (1)
in which
R10 R11 and R12 are each independently hydrogen, Cl- to C2o-alkyl, C5- to C8-
cycloalkyl,
C6- to C2o-aryl, C?- to C20-alkylaryl or phenyl, where any aromatic ring may
also bear one
or more C1- to C4-alkyl- or C1- to C4-alkoxy radicals or moieties of the
general formula II
R10
n
R12
(II)
as substituents, where not more than one of the variables R10, R11 or R12 is
hydrogen and
at least one of the variables R1o R11 or R12 is phenyl which may also bear one
or more
C1- to C4-alkyl- or C1- to C4-alkoxy radicals or moieties of the general
formula II as
substituents, and
n is a number from 9 to 4500, preferably 9 to 180, especially 9 to 100, in
particular 12 to
50.
In a preferred embodiment, R5, R6 and Ware each independently hydrogen, C1- to
C4-alkyl, especially methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,
sec.-butyl or
tert-butyl, or phenyl which may also bear one or two C1- to C4-alkyl- or Ci-
to C4-alkoxy
radicals or moieties of the general formula II as substituents, where not more
than one of
the variables R5, R6 and R7 is hydrogen and at least one of the variables R5,
R6 and R7 is
phenyl which may also bear one or two C1- to C4-alkyl or C1- to C4-alkoxy
radicals or
moieties of the general formula II as substituents, and n is a number from 9
to 4500,
preferably 9 to 180, especially 9 to 90, in particular 15 to 45.
CA 02789843 2012-08-14
19
The process according to the invention successfully polymerizes isobutene or
isobutene-
comprising monomer mixtures under cationic conditions with satisfactory to
high
conversions of generally 20 to 100%, especially 35 to 90%, in short reaction
times of
generally 5 to 120 minutes, especially 30 to 120 minutes, to give high-
reactivity isobutene
homo- or copolymers with a content of terminal vinylidene double bonds per
polyisobutene chain end of at least 80 mol% and with a narrow molecular weight
distribution.
The examples which follow are intended to illustrate the present invention in
detail without
restricting it.
Example 1: Polymerization of isobutene with AIC13=Bu20without initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
dichloromethane and 5 ml of n-hexane at -20 C with 0.62 mmol of the complex of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) within 30 minutes at a conversion of 71 % to give
a
polyisobutene with a number-average molecular weight Mn of 2095, a
polydispersity (PDI)
of 2.27 and a content of terminal vinylidene double bonds of 91 mol%.
Example 2: Polymerization of isobutene with AIC13= EtOAc without initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
dichloromethane and 5 ml of n-hexane at -20 C with 0.62 mmol of the complex of
aluminum trichloride and ethyl acetate in a molar ratio of 1:1 (in the form of
a 1 molar
solution in dichloromethane) within 30 minutes at a conversion of 17% to give
a
polyisobutene with a number-average molecular weight Mn of 1930, a
polydispersity (PDI)
of 1.45 and a content of terminal vinylidene double bonds of 88 mol%.
Example 3: Polymerization of isobutene with AIC13=Bu20with cumene as an
initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
dichloromethane and 5 ml of n-hexane at -40 C with 0.62 mmol of the complex of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.5 mmol of 2-phenyl-2-
propanol
(cumene) as an initiator within 30 minutes at a conversion of 62% to give a
polyisobutene
with a number-average molecular weight Mn of 1515, a polydispersity (PDI) of
1.45 and a
content of terminal vinylidene double bonds of 90 mol%. The proportion of
cumene-
started polymer chains (leff) was 70%.
CA 02789843 2012-08-14
Example 4: Polymerization of isobutene with AICI3=Bu20 with cumene as an
initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
5 dichloromethane and 5 ml of n-hexane at -40 C with 1.24 mmol of the complex
of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 1.0 mmol of 2-phenyl-2-
propanol
(cumene) as an initiator within 30 minutes at a conversion of 76% to give a
polyisobutene
with a number-average molecular weight Mn of 1180, a polydispersity (PDI) of
1.21 and a
10 content of terminal vinylidene double bonds of 88 mol%. The proportion of
cumene-
started polymer chains (leff) was 90%.
Example 5: Polymerization of isobutene with AICI3=Bu20 with cumene as an
initiator
15 1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml
of
dichloromethane and 5 ml of n-hexane at -60 C with 0.62 mmol of the complex of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.5 mmol of 2-phenyl-2-
propanol
(cumene) as an initiator within 31 minutes at a conversion of 91 % to give a
polyisobutene
20 with a number-average molecular weight M, of 2275, a polydispersity (PDI)
of 1.83 and a
content of terminal vinylidene double bonds of 85 mol%. The proportion of
cumene-
started polymer chains (leff) was 90%.
Example 6: Polymerization of isobutene with AICI3=Bu20 with cumene as an
initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 15 ml of
dichloromethane and 10 ml of n-hexane at -60 C with 0.36 mmol of the complex
of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.29 mmol of 2-phenyl-2-
propanol
(cumene) as an initiator within 120 minutes at a conversion of 56% to give a
polyisobutene with a number-average molecular weight M, of 2690, a
polydispersity (PDI)
of 1.91 and a content of terminal vinylidene double bonds of 89 mol%. The
proportion of
cumene-started polymer chains (leff) was 88%.
Example 7a: Polymerization of isobutene with AIC13=Bu20 with cumene as an
initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 15 ml of
dichloromethane and 10 ml of n-hexane at -60 C with 0.36 mmol of the complex
of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.09 mmol of 2-phenyl-2-
propanol
CA 02789843 2012-08-14
21
(cumene) as an initiator within 30 minutes at a conversion of 47% to give a
polyisobutene
with a number-average molecular weight Mn of 3510, a polydispersity (PDI) of
2.17 and a
content of terminal vinylidene double bonds of 95 mol%. The proportion of
cumene-
started polymer chains (leff) was 37%.
Example 7b: Polymerization of isobutene with AIC13=Bu20with cumene as an
initiator
Example 7a was repeated, except that the reaction time was quadrupled: after
120 minutes, at a conversion of 62%, a polyisobutene was obtained with a
number-
average molecular weight M, of 3360, a polydispersity (PDI) of 1.93 and a
content of
terminal vinylidene double bonds of 91 mol% polymerized. The proportion of
cumene-
started polymer chains (leff) was 23%.
Example 8: Polymerization of isobutene with AIC13=Bu20with cumene as an
initiator
2.97 g (53.0 mmol) of pure isobutene were polymerized in 66 ml of
dichloromethane at
-15 C with 2.15 mmol of the complex of aluminum trichloride and di-n-butyl
ether in
a molar ratio of 1:1 (in the form of a 1 molar solution in dichloromethane) in
the presence
of 1.0 mmol of 2-phenyl-2-propanol (cumene) as an initiator within 60 minutes
at a
conversion of 40% to give a polyisobutene with a number-average molecular
weight Mn of
1675, a polydispersity (PDI) of 1.75 and a content of terminal vinylidene
double bonds of
96 mol%.
Example 9: Polymerization of isobutene with AIC13=Bu20with cumene as an
initiator
3.09 g (55.0 mmol) of pure isobutene were polymerized in 66 ml of
dichloromethane at
-60 C with 1.80 mmol of the complex of aluminum trichloride and di-n-butyl
ether in
a molar ratio of 1:1 (in the form of a 1 molar solution in dichloromethane) in
the presence
of 1.0 mmol of 2-phenyl-2-propanol (cumene) as an initiator within 60 minutes
at a
conversion of 99% to give a polyisobutene with a number-average molecular
weight M, of
1700, a polydispersity (PDI) of 1.82 and a content of terminal vinylidene
double bonds of
96 mol%.
Example 10: Polymerization of isobutene with AIC13Ø8 Bu20with cumene as an
initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
dichloromethane and 5 ml of n-hexane at -20 C with 0.62 mmol of the complex of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:0.8 (in the
form of a 1 molar
solution in dichloromethane) in the presence of 0.5 mmol of 2-phenyl-2-
propanol
(cumene) as an initiator within 30 minutes at a conversion of 44% to give a
polyisobutene
CA 02789843 2012-08-14
22
with a number-average molecular weight Mn of 1550, a polydispersity (PDI) of
1.74 and a
content of terminal vinylidene double bonds of 87 mol%. The proportion of
cumene-
started polymer chains (leff) was 56%.
Example 11: Polymerization of "raffinate 1" with AIC13=Bu20with cumene as an
initiator
7.43 g of "raffinate 1", comprising 2.97 g (53.0 mmol) of pure isobutene, were
polymerized in 66 ml of dichloromethane at -30 C with 2.15 mmol of the complex
of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 1.0 mmol of 2-phenyl-2-
propanol
(cumene) as an initiator within 60 minutes at a conversion of 30% to give a
polyisobutene
with a number-average molecular weight Mn of 1720, a polydispersity (PDI) of
2.04 and a
content of terminal vinylidene double bonds of 93 mol%.
Example 12a: Polymerization of isobutene with AICI3=Bu20with cumene as an
initiator
2.97 g (53.0 mmol) of pure isobutene were polymerized in 66 ml of
dichloromethane at
-60 C with 1.43 mmol of the complex of aluminum trichloride and di-n-butyl
ether in
a molar ratio of 1:1 (in the form of a 1 molar solution in dichloromethane) in
the presence
of 1.0 mmol of 2-phenyl-2-propanol (cumene) as an initiator within 60 minutes
at a
conversion of 100% to give a polyisobutene with a number-average molecular
weight Mn
of 6005, a polydispersity (PDI) of 2.26 and a content of terminal vinylidene
double bonds
of 94 mol%.
Example 12b: Polymerization of isobutene with BF3=MeOH (for comparison against
inventive example 12a)
2.97 g (53.0 mmol) of pure isobutene were polymerized in 66 ml of
dichloromethane at -
60 C with 1.34 mmol of the complex of boron trifluoride and methanol in a
molar ratio of
1:1 within 60 minutes at a conversion of 43% to give a polyisobutene with a
number-
average molecular weight Mn of 4850, a polydispersity (PDI) of 4.05 and a
content of
terminal vinylidene double bonds of only 62.5 mol%.
Example 13: Polymerization of isobutene with AIC13=Bu20with 1-phenyl-1-
chloroethane
as an initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
dichloromethane and 5 ml of n-hexane at -40 C with 0.62 mmol of the complex of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.5 mmol of 1-phenyl-1-
chloroethane as
CA 02789843 2012-08-14
23
an initiator within 30 minutes at a conversion of 77% to give a polyisobutene
with a
number-average molecular weight Mn of 2170, a polydispersity (PDI) of 1.99 and
a
content of terminal vinylidene double bonds of 88 mol%. The proportion of 1-
phenyl-1-
chloroethane started polymer chains (leff) was 4%.
Example 14: Polymerization of isobutene with AIC13=Bu20 with 1-(p-
methoxyphenyl)-
ethanol as an initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
dichloromethane and 5 ml of n-hexane at -20 C with 0.62 mmol of the complex of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.5 mmol of 1-(p-
methoxyphenyl)ethanol
as an initiator within 10 minutes at a conversion of 26% to give a
polyisobutene with a
number-average molecular weight Mn of 960, a polydispersity (PDI) of 1.05 and
a content
of terminal vinylidene double bonds of 88 mol%.
Example 15a: Polymerization of isobutene with AICI3=Bu20 with cumene as an
initiator in
the presence of pyridine
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 15 ml of
dichloromethane and 10 ml of n-hexane at -60 C with 0.36 mmol of the complex
of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.09 mmol of 2-phenyl-2-
propanol
(cumene) as an initiator and 0.0125 mol of pyridine as a nitrogen-containing
basic
compound within 30 minutes at a conversion of 44% to give a polyisobutene with
a
number-average molecular weight Mn of 2580, a polydispersity (PDI) of 1.86 and
a
content of terminal vinylidene double bonds of 90 mol%. The proportion of
cumene-
started polymer chains (leff) was 36%.
Example 15b: Polymerization of isobutene with AIC13=Bu20 and with cumene as an
initiator in the presence of pyridine
Example 15a was repeated, except that the reaction time was quadrupled: after
120 minutes, at a conversion of 53%, a polyisobutene was obtained with a
number-
average molecular weight Mn of 2490, a polydispersity (PDI) of 1.84 and a
content of
terminal vinylidene double bonds of 91 mol% polymerized. The proportion of
cumene-
started polymer chains (leff) was 26%.
Example 16: Polymerization of isobutene with AIC13=Bu20 with cumene as an
initiator in
the presence of pyridine
CA 02789843 2012-08-14
24
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 15 ml of
dichloromethane and 10 ml of n-hexane at -20 C with 0.36 mmol of the complex
of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.09 mmol of 2-phenyl-2-
propanol
(cumene) as an initiator and 0.0125 mol of pyridine as a nitrogen-containing
basic
compound within 120 minutes at a conversion of 21 % to give a polyisobutene
with a
number-average molecular weight Mn of 1445, a polydispersity (PDI) of 1.69 and
a
content of terminal vinylidene double bonds of 94 mol%. The proportion of
cumene-
started polymer chains (leff) was 27%.
Example 17: Polymerization of isobutene with AIC13=Bu20 with cumene as an
initiator in
the presence of pyridine
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
dichloromethane and 5 ml of n-hexane at -40 C with 0.62 mmol of the complex of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.5 mmol of 2-phenyl-2-
propanol
(cumene) as an initiator and 0.0125 mol of pyridine as a nitrogen-containing
basic
compound within 30 minutes at a conversion of 51 % to give a polyisobutene
with a
number-average molecular weight M, of 1270, a polydispersity (PDI) of 1.17 and
a
content of terminal vinylidene double bonds of 91 mol%. The proportion of
cumene-
started polymer chains (leff) was 48%.
Example 18: Polymerization of isobutene with AICI3=Bu20 and with 1-phenyl-1-
chioroethane as an initiator
1.43 g (2.25 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
dichloromethane and 5 ml of n-hexane at -20 C with 0.62 mmol of the complex of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.5 mmol of 1-phenyl-1-
chloroethane as
an initiator within 3 minutes at a conversion of 37% to give a polyisobutene
with a
number-average molecular weight M, of 3270, a polydispersity (PDI) of 1.76 and
a
content of terminal vinylidene double bonds of 97 mol%.
Example 19: Polymerization of isobutene with AIC13=Bu20 and with 1,4-bis(1-
hydroxy-1-
m ethyl ethyl) benzene as an initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 20 ml of
dichloromethane and 5 ml of n-hexane at -20 C with 0.62 mmol of the complex of
CA 02789843 2012-08-14
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) in the presence of 0.25 mmol of 1,4-bis(1-hydroxy-
1-
m ethyl ethyl) benzene as an initiator within 3 minutes at a conversion of 36%
to give a
polyisobutene with a number-average molecular weight Mn of 2750, a
polydispersity (PDI)
5 of 1.99 and a content of terminal vinylidene double bonds of 94 mol%.
Example 20: Polymerization of isobutene with AIC13=Bu20without initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 15 ml of
10 dichloromethane and 10 ml of n-hexane at -60 C with 0.36 mmol of the
complex of
aluminum trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form
of a 1 molar
solution in dichloromethane) within 120 minutes at a conversion of 46% to give
a
polyisobutene with a number-average molecular weight Mn of 7895, a
polydispersity (PDI)
of 2.23 and a content of terminal vinylidene double bonds of 94 mol%.
Example 21: Polymerization of isobutene with AICI3=Bu20 and with water as an
initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in 25 ml of
dichloromethane at
-20 C with 0.62 mmol of the complex of aluminum trichloride and di-n-butyl
ether in
a molar ratio of 1:1 (in the form of a 1 molar solution in dichloromethane) in
the presence
of 0.07 mmol of water as an initiator within 3 minutes at a conversion of 65%
to give a
polyisobutene with a number-average molecular weight Mn of 2500, a
polydispersity (PDI)
of 1.92 and a content of terminal vinylidene double bonds of 92 mol%.
Example 22: Polymerization of isobutene with AIC13=Bu20 and with cumene as an
initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in 25 ml of toluene at -
20 C with
0.62 mmol of the complex of aluminum trichloride and di-n-butyl ether in a
molar ratio of
1:1 (in the form of a 1 molar solution in dichloromethane) in the presence of
0.5 mmol of
2-phenyl-2-propanol (cumene) as an initiator within 10 minutes at a conversion
of 19% to
give a polyisobutene with a number-average molecular weight Mn of 1030, a
polydispersity (PDI) of 2.65 and a content of terminal vinylidene double bonds
of
89 mol%. The proportion of cumene-started polymer chains (leff) was 98%.
Example 23: Polymerization of isobutene with AIC13=Bu20 and with cumene as an
initiator
1.43 g (25.5 mmol) of pure isobutene were polymerized in a mixture of 15 ml of
toluene
and 10 ml of trifluoromethylbenzene at -20 C with 0.62 mmol of the complex of
aluminum
trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form of a 1
molar solution in
dichloromethane) in the presence of 0.5 mmol of 2-phenyl-2-propanol (cumene)
as an
CA 02789843 2012-08-14
26
initiator within 3 minutes at a conversion of 24% to give a polyisobutene with
a number-
average molecular weight M,, of 1095, a polydispersity (PDI) of 1.93 and a
content of
terminal vinylidene double bonds of 78 mol%. The proportion of cumene-started
polymer
chains (Ieff) was 94%.
Example 24: Polymerization of isobutene with AIC13=Bu20 and with cumene as an
initiator
3.00 g (53 mmol) of pure isobutene were polymerized in 50 ml of
dichloromethane at
-60 C with 187.2 mg of the complex of aluminum trichloride and di-n-butyl
ether in
a molar ratio of 1:1 (in the form of a I molar solution in dichloromethane) in
the presence
of 24.5 mg of 2-phenyl-2-propanol (cumene) as an initiator within 120 minutes
at a
conversion of 23% to give a polyisobutene with a number-average molecular
weight Mn of
3210, a polydispersity (PDI) of 1.90 and a content of terminal vinylidene
double bonds of
> 99 mol%.
Example 25: Polymerization of isobutene with AIC13=Bu20 and with cumene as an
initiator
3.00 g (53 mmol) of pure isobutene were polymerized in 50 ml of
dichloromethane at
-60 C with 1140 mg of the complex of aluminum trichloride and di-n-butyl ether
in a molar
ratio of 1:1 (in the form of a 1 molar solution in dichloromethane) in the
presence of
24.5 mg of 2-phenyl-2-propanol (cumene) as an initiator within 120 minutes at
a
conversion of 100% to give a polyisobutene with a number-average molecular
weight Mn
of 4220, a polydispersity (PDI) of 2.05 and a content of terminal vinylidene
double bonds
of > 99 moI%.
Example 26: Polymerization of "raffinate 1" with AIC13=Bu20 and with cumene as
an
initiator
7.50 g of "raffinate 1", comprising 3.00 g (53 mmol) of pure isobutene, were
polymerized
in 50 ml of dichloromethane at -60 C with 566.8 mg of the complex of aluminum
trichloride and di-n-butyl ether in a molar ratio of 1:1 (in the form of a 1
molar solution in
dichloromethane) in the presence of 24.5 mg of 2-phenyl-2-propanol (cumene) as
an
initiator within 60 minutes at a conversion of 80% to give a polyisobutene
with a number-
average molecular weight Mn of 4770, a polydispersity (PDI) of 2.67 and a
content of
terminal vinylidene double bonds of 96 mol%.
Example 27: Polymerization of "raffinate 1" with AICI3=Bu20without solvent and
with
water as an initiator
CA 02789843 2012-08-14
27
69.25 g of "raffinate I", comprising 27.7 g (494 mmol) of pure isobutene, were
polymerized in an autoclave with 6.54 g of the complex of aluminum trichloride
and di-n-
butyl ether prepared in situ in a molar ratio of 1:1, in the presence of 0.43
g (23.8 mmol)
of water as an initiator without solvent at 0 C within 60 minutes at a
conversion of 76% to
give a polyisobutene with a number-average molecular weight Mn of 965, a
polydispersity
(PDI) of 2.86 and a content of terminal vinylidene double bonds of 76 mol%.
Example 28: Polymerization of "raffinate 1" with AIC13=Bu20without solvent and
with
water as an initiator
72.75 g of "raffinate 1", comprising 29.1 g (519 mmol) of pure isobutene, were
polymerized in an autoclave with 6.79 g of the complex of aluminum trichloride
and di-n-
butyl ether prepared in situ in a molar ratio of 1:1, in the presence of 0.46
g (25.4 mmol)
of water as an initiator without solvent at +20 C within 60 minutes at a
conversion of 69%
to give a polyisobutene with a number-average molecular weight Mn of 800, a
polydispersity (PDI) of 2.69 and a content of terminal vinylidene double bonds
of
70 mol%.
Example 29: Polymerization of "raffinate 1" with AICI3=Bu20without solvent and
without
initiator
56.75 g of "raffinate 1", comprising 22.7 g (405 mmol) of pure isobutene, were
polymerized in an autoclave with 6.57 g of the complex of aluminum trichloride
and di-n-
butyl ether prepared in situ in a molar ratio of 1:1 without solvent at +20 C
within
60 minutes at a conversion of 93% to give a polyisobutene with a number-
average
molecular weight Mn of 1000, a polydispersity (PDI) of 2.90 and a content of
terminal
vinylidene double bonds of 76 mol%.
Example 30: Polymerization of "raffinate 1" with AIC13=Bu20without solvent and
without
initiator
62.25 g of "raffinate 1", comprising 24.9 g (444 mmol) of pure isobutene, were
polymerized in an autoclave with 6.56 g of the complex of aluminum trichloride
and di-n-
butyl ether prepared in situ in a molar ratio of 1:1 without solvent at 0 C
within 60 minutes
at a conversion of 88% to give a polyisobutene with a number-average molecular
weight
Mn of 1375, a polydispersity (PDI) of 2.94 and a content of terminal
vinylidene double
bonds of 69 mol%.
