[0001] The present invention is directed to a new method for preparing a solid catalyst
system enabling the efficient preparation of polymers. Furthermore, the present invention
is directed at a solid catalyst system obtainable, preferably obtained from the inventive
method.
[0002] In the field of catalysts since many years great efforts are undertaken to further
improve the catalyst types tailored for specific purposes. For instance in polymerisation
processes single site, like metallocene, catalyst systems are widely used having many
advantages.
[0003] At the beginning of the development of new metallocene catalyst systems only homogeneous
catalyst systems were available. Such homogeneous catalyst systems are solutions of
one or more catalyst components, e.g. a transition metal compound and optionally a
cocatalyst. Homogeneous systems are used as liquids in the polymerisation process.
Such systems have in general a satisfactory catalytic activity, but their problem
has been that the polymer thus produced has a poor morphology (e.g. the polymer obtained
is in a form of a fluff having a low bulk density). As a consequence, operation of
slurry and gas phase reactors using a homogeneous catalyst system causes problems
in practice, for instance in terms of reactor fouling.
[0004] To overcome the problems of the homogeneous catalyst systems, supported systems have
been developed. These supported systems, known as heterogeneous catalyst systems,
comprise carrier materials, such as porous organic and inorganic support materials,
like silica, aluminoxane or porous polymeric materials onto which the catalyst is
loaded or supported.
[0005] However, also supported catalyst systems cause problems. To mention only one among
many, it is difficult to get an even distribution of the catalyst components in the
porous carrier material. Further leaching of the catalyst components from the support
can occur. Such drawbacks lead to an unsatisfactory polymerisation behavior of the
catalyst, and as a result, the morphology of the polymer product thus obtained is
also poor. Further such classic heterogeneous catalyst systems show reduced catalytic
activity, which is of course detrimental, as the catalyst amount must be increased,
which in turn leads to polymer products contaminated with rather high amounts of catalyst
residues including silica residues, which might be very detrimental in some product
applications.
[0006] For this reason a new single site, like metallocene catalyst system has been developed
which significantly reduces the drawbacks of the known heterogeneous catalyst systems.
Such new catalyst systems are solid catalyst systems, but are not in need of catalytically
inert support material, and are further featured by spherical particles with low porosity.
Such new metallocene catalyst systems enable to increase the output rate of polymers,
since the bulk density of the polymerised product can be increased. For the first
time such new metallocene catalyst systems have been described in
WO 03/051934. These types of catalysts have solved many problems caused by catalysts of earlier
prior art.
[0007] Many prior art catalysts have, however, a general drawback relating to their tendency
to dissolve in the polymerisation medium, and thus causing undesired fouling in the
reactors. Thus, there remains still some work to do to improve the properties of the
catalyst, especially in view of morphology and in that the desired morphology would
remain and be effectively used, during the polymerisation, which would also decrease
fouling and sheeting problems
[0008] Moreover, nowadays the catalyst shall be not only suitable for specific processes
for producing desired polymers but there is a general tendency to find out methods,
also in catalyst preparation field, where the starting materials are safer and easier
to be used both in environmental as well handling point of view. Thus there is the
strong need to develop preparation methods of such catalyst systems based on materials
which promote sustainable preparation method as well as are easily commercially accessible
and thus well priced.
[0009] Much effort has been put into improving the methods for preparing support-free metallocene
catalyst as described in
WO 03/051934. Most research since has been focused at improving the emulsification/solidification
technology in which an emulsion is formed wherein the continuous phase, in which a
solution of the catalyst components forms the dispersed phase in the form of droplets,
is immiscible with said catalyst component solution.
[0010] WO 2011/138211 describes an improved and suitable process for preparing solid metallocene catalyst
systems with the emulsion/solidification technology, in which a liquid clathrate constitutes
the dispersed phase of the emulsion and the solvent used for the continuous phase
of the emulsion is a non-reactive fluorinated synthetic oil.
[0011] Unfortunately such catalyst systems, prepared by the emulsification/solidification
technology comprising a metallocene catalyst in combination with an aluminoxane co-catalyst,
have also some disadvantages, even when having the dispersed phase in form of a liquid
clathrate.
[0012] For example, such catalyst systems have a tendency to dissolve to some extent in
common polymerisation media. The solubility can lead to catalyst leaching, which is
further associated with reactor fouling and sheeting.
[0013] Recently it has been found that support-free catalyst systems comprising a metallocene
catalyst in combination with an aluminoxane co-catalyst can be obtained from a solution
without applying the emulsion/solidification technology.
EP 2 386 582 A1 describes a process in which a solid catalyst is obtained from preparing a liquid
clathrate from aluminoxane, organometallic compound (metallocene) and a compound being
able to form lattice with aluminoxane and metallocene, and a hydrocarbon compound,
and subsequent precipitation. The compound being able to form lattice with aluminoxane
and metallocene is said to be either M-X compound or an organosilicon compound, and
precipitation is carried out with silicon oil. From this precipitation technology,
solid catalyst particles could be obtained with improved leaching properties, however,
this approach resulted in solid catalyst particles with lower catalytic activity compared
to similar solid catalyst particles obtained by the emulsion/solidification technology.
In this respect exceptionally low catalytic activities in propylene polymerisation
could be observed, in particular when catalysts were prepared in presence of siloxanes.
[0014] Thus the object of the present invention is to find an improved and suitable process
for the manufacture of solid catalyst systems without the need of external support
materials, and which render possible to produce polymers in an efficient manner, i.e.
using solid catalyst systems which are less soluble in the polymerisation media, and
are obtained by a reliable process yielding catalyst systems with high catalytic activities
towards olefins such as propylene and ethylene, in particular towards propylene.
[0015] The finding of the present invention is that the solid catalyst system must be produced
by preparing first a liquid clathrate of activator and clathrating agent using a specific
ratio with respect to clathrating agent and activator, and after that forming a liquid
mixture of said liquid clathrate and an organometallic compound, which liquid mixture
is converted into solid form by precipitation using specified precipitation agent.
[0016] Thus the present invention is directed to a process for the preparation of a solid
catalyst system (CS) comprising the steps of
- (i) preparing a liquid clathrate (LC) comprising a mixing step of an aluminoxane (A),
an aromatic compound (AC) and an organo-silicon compound (OS), wherein the mol-ratio
between the organo-silicon compound (OS) and aluminum (Al) of the aluminoxane (A)
[(OS)/(Al)] is equal or below 0.1,
- (ii) mixing said liquid clathrate (LC) with an organometallic compound (C) obtaining
a liquid mixture (MI), wherein the liquid mixture (MI) is homogeneous,
- (iii) precipitating the solid catalyst system (CS) out of said liquid mixture (MI)
by adding a saturated aliphatic compound to said mixture (MI)
- (iv) optionally recovering particles of the solid catalyst system (CS),
wherein preferably during the process no carrier material, i.e. no external catalytically
inert support material, is added.
[0017] Surprisingly it has been found out that with the above defined process in an effective
manner solid catalyst systems (CS) can be obtained, which enables a person skilled
in the art to efficiently produce polymers having good morphology and with acceptable
activity. The process of the invention is easy to control due to the separate process
steps for producing liquid clathrate (LC) and further liquid catalyst mixture (MI)
as well due to the improved precipitation step. When applying said solid catalyst
systems (CS) in polymerisation processes, high catalytic activities could be observed
without the occurrence of reactor fouling.
[0018] The solid catalyst system (CS) obtained according to the instant process is solid
without external catalytically inert support material.
[0019] External catalytically inert support material according to this invention is any
material which is used to decrease solubility of the catalyst systems in media which
are generally used in polymerization processes. Of course such material has no catalitical
activity, especially in the polymerization process, like in a polyolefin polymerization
process, e.g. in a polyethylene or polypropylene polymerization process. Accordingly
said external catalytically inert support material is a material which effectively
decreases solubility in common polymerization media. Typical external catalytically
inert support materials are organic and inorganic support materials, like silica,
solid aluminoxane or porous polymeric materials, onto which catalyst components are
loaded. These support materials are generally used in amounts of at least 50wt.-%,
more preferably of at least 70.0 wt.-%. Accordingly in the inventive process rather
low amount of external catalytically inert support material is used (if used at all).
Preferably the amount of external catalytically inert support material used in the
process is below 10.0 wt.-%, more preferably below 5.0 wt.-%, yet more preferably
no external catalytically inert support material used. Accordingly the amount of such
external catalytically inert support material within the obtained solid catalyst system
(CS) is below 10.0 wt.%, yet more preferably below 5.0 wt.-%, yet more preferably
not detectable, like not present.
[0020] Throughout the invention the terms "external catalytically inert support material"
and "carrier material" are interchangeable.
[0021] Furthermore, it has been found that the activity decreasing effect of the clathrating
agent (OS) can be compensated when the ratio between the clathrating agent (OS) and
aluminoxane (A) is carefully controlled.
[0022] Further, using saturated hydrocarbon compound instead of silicone fluid in precipitation
step shows a clear benefit in activity of the catalyst.
[0023] The organometallic compound (C) preferably comprises a transition metal (M) of group
3 to 10 of the Periodic Table (IUPAC 2007) or of an actinide or lanthanide.
[0024] The term "an organometallic compound (C)" in accordance with the present invention
preferably includes any metallocene or non-metallocene compound of a transition metal
which bears at least one organic (coordination) ligand and exhibits the catalytic
activity alone or together with a cocatalyst. The transition metal compounds are well
known in the art and the present invention covers compounds of metals from group 3
to 10, e.g. group 3 to 7, or 3 to 6, such as group 4 to 6 of the Periodic Table, (IUPAC
2007), as well as lanthanides or actinides.
[0025] In one embodiment the organometallic compound (C) has the following formula (I):
(L)
mR
nMX
q (I)
wherein
"M" is a transition metal (M) of group 3 to 10 of the Periodic Table (IUPAC 2007),
each "X" is independently a mono anionic ligand, such as a σ-ligand,
each "L" is independently an organic ligand which coordinates to the transition metal
"M",
"R" is a bridging group linking said organic ligands (L),
"m" is 1, 2 or 3, preferably 2,
"n" is 0, 1 or 2, preferably 1,
"q" is 1, 2 or 3, preferably 2, and
m+q is equal to the valency of the transition metal (M).
[0026] "M" is preferably selected from the group consisting of zirconium (Zr), hafnium (Hf),
or titanium (Ti), more preferably selected from the group consisting of zirconium
(Zr) and hafnium (Hf).
[0027] In a more preferred definition, each organic ligand (L) is independently
- (a) a substituted or unsubstituted cyclopentadienyl or a bi- or multicyclic derivative
of a cyclopentadienyl which optionally bear further substituents and/or one or more
hetero ring atoms from a group 13 to 16 of the Periodic Table (IUPAC 2007); or
- (b) an acyclic η1- to η4- or η6-ligand composed of atoms from groups 13 to 16 of the Periodic Table, and in which
the open chain ligand may be fused with one or two, preferably two, aromatic or non-aromatic
rings and/or bear further substituents; or
- (c) a cyclic η1- to η4- or η6-, mono-, bi- or multidentate ligand composed of unsubstituted or substituted mono-,
bi- or multicyclic ring systems selected from aromatic or non-aromatic or partially
saturated ring systems, such ring systems containing optionally one or more heteroatoms
selected from groups 15 and 16 of the Periodic Table (IUPAC 2007).
[0028] Organometallic compounds (C), preferably used in the present invention, have at least
one organic ligand (L) belonging to the group (a) above. Such organometallic compounds
are called metallocenes.
[0029] More preferably at least one of the organic ligands (L) belonging to group (a), preferably
both organic ligands (L), is (are) selected from the group consisting of cyclopentadienyl,
indenyl, tetrahydroindenyl, fluorenyl, which can be independently substituted or unsubstituted.
Further, in case said organic ligands (L) are substituted it is preferred that at
least one organic ligand (L), preferably both organic ligands (L), comprise one or
more substituents independently selected from C
1 to C
20 hydrocarbyl or silyl groups, which optionally contain one or more heteroatoms selected
from groups 14 to 16 and/or are optionally substituted by halogen atom(s),
[0030] The term C
1 to C
20 hydrocarbyl group, whenever used in the present application, includes C
1 to C
20 alkyl, C
2 to C
20 alkenyl, C
2 to C
20 alkynyl, C
3 to C
20 cycloalkyl, C
3 to C
20 cycloalkenyl, C
6 to C
20 aryl, C
7 to C
20 alkylaryl or C
7 to C
20 arylalkyl groups or mixtures of these groups such as cycloalkyl substituted by alkyl.
[0031] Further, two substituents, which can be same or different, attached to adjacent C-atoms
of a ring of the ligands (L) can also taken together form a further mono or multicyclic
ring fused to the ring.
[0032] Preferred hydrocarbyl groups are independently selected from linear or branched C
1 to C
10 alkyl groups, optionally interrupted by one or more heteroatoms of groups 14 to 16,
like O, N or S, and substituted or unsubstituted C
6 to C
20 aryl groups.
[0033] Linear or branched C
1 to C
10 alkyl groups, optionally interrupted by one or more heteroatoms of groups 14 to 16,
are more preferably selected from methyl, ethyl, propyl, isopropyl, tertbutyl, isobutyl,
C
5-6 cycloalkyl, OR, SR, where R is C
1 to C
10 alkyl group,
[0034] C
6 to C
20 aryl groups are more preferably phenyl groups, optionally substituted with 1 or 2
C
1 to C
10 alkyl groups as defined above.
[0035] By "σ-ligand" is meant throughout the invention a group bonded to the transition
metal (M) via a sigma bond.
[0036] Further, the ligands "X" are preferably independently selected from the group consisting
of hydrogen, halogen, C
1 to C
20 alkyl, C
1 to C
20 alkoxy, C
2 to C
20 alkenyl, C
2 to C
20 alkynyl, C
3 to C
12 cycloalkyl, C
6 to C
20 aryl, C
6 to C
20 aryloxy, C
7 to C
20 arylalkyl, C
7 to C
20 arylalkenyl, -SR", -PR"
3, -SiR"
3, -OSiR"
3 and -NR"
2, wherein each R" is independently hydrogen, C
1 to C
20 alkyl, C
2 to C
20 alkenyl, C
2 to C
20 alkynyl, C
3 to C
12 cycloalkyl or C
6 to C
20 aryl.
[0037] More preferably "X" ligands are selected from halogen, C
1 to C
6 alkyl, C
5 to C
6 cycloalkyl, C
1 to C
6 alkoxy, phenyl and benzyl groups.
[0038] The bridging group "R" may be a divalent bridge, preferably selected from -R'
2C-, -R'
2C-CR'
2-, -R'
2Si-, -R'
2Si-Si R'
2-, -R'
2Ge-, wherein each R' is independently a hydrogen atom, C
1 to C
20 alkyl, C
2 to C
10 cycloalkyl, tri(C
1 to C
20 alkyl)silyl, C
6 to C
20 aryl, C
7 to C
20 arylalkyl and C
7 to C
20 to alkylaryl.
[0039] More preferably the bridging group "R" is a divalent bridge selected from -R'
2C-, -R'
2Si-, wherein each R' is independently a hydrogen atom, C
1 to C
20 alkyl, C
2 to C
10 cycloalkyl, C
6 to C
20 aryl, C
7 to C
20 arylalkyl and C
7 to C
20 alkylaryl.
[0040] Another subgroup of the organometallic compounds (C) of formula (I) is known as non-metallocenes
wherein the transition metal (M), preferably a Group 4 to 6 transition metal, suitably
Ti, Zr or Hf, has a coordination ligand other than a cyclopentadienyl ligand. The
term "non-metallocene" used herein means compounds, which bear no cyclopentadienyl
ligands or fused derivatives thereof, but one or more non-cyclopentadienyl η-, or
σ-, mono-, bi- or multidentate ligand. Such ligands can be chosen e.g. from the groups
(b) and (c) as defined above and described e.g. in
WO 01/70395,
WO 97/10248,
WO 99/41290, and
WO 99/10353), and further in
V. C. Gibson et al., in Angew. Chem. Int. Ed., engl., vol 38, 1999, pp 428 447.
[0041] However, the organometallic compound (C) of the present invention is preferably a
metallocene as defined above.
[0042] Metallocenes are described in numerous patents. In the following just a few examples
are listed;
EP 260 130,
WO 97/28170,
WO 98/46616,
WO 98/49208,
WO 98/040331,
WO 99/12981,
WO 99/19335,
WO 98/56831,
WO 00/34341,
WO00/148034,
EP 423 101,
EP 537 130,
WO2002/02576,
WO2005/105863,
WO 2006097497,
WO2007/116034,
WO2007/107448,
WO2009/027075,
WO2009/054832,
WO 2012/001052 and
EP 2532687. Further, metallocenes are described widely in academic and scientific articles.
[0043] In the following the essential features of the present invention are described in
more detail.
[0044] The present invention is directed at a process for the preparation of a solid catalyst
system (CS) comprising the steps of
- (i) preparing a liquid clathrate (LC) comprising a mixing step of an aluminoxane (A),
an aromatic compound (AC) and an organo-silicon compound (OS), wherein the mol-ratio
between the organo-silicon compound (OS) and aluminum (Al) of the aluminoxane (A)
[(OS)/(A1)] is below 0.1,
- (ii) mixing said liquid clathrate (LC) with an organometallic compound (C) obtaining
a liquid mixture (MI), said organometallic compound (C) is of formula (I)
(L)mRnMXq (I)
wherein
"M" is a transition metal (M) of group 3 to 10 of the Periodic Table (IUPAC 2007),
each "X" is independently a monoanionic ligand, such as σ-ligand,
each "L" is independently an organic ligand which coordinates to the transition metal
(M),
"R" is a bridging group linking said organic ligands (L),
"m" is 2 or 3, preferably 2,
"n" is 0, 1 or 2, preferably 1,
"q" is 1, 2 or 3, preferably 2,
m+q is equal to the valency of the transition metal (M),
- (iii) precipitating the solid catalyst system (CS) by adding a saturated aliphatic
compound to said liquid mixture (MI)
- (iv) optionally recovering particles to obtain the solid catalyst system (CS).
[0045] According to the invention first step (step (i)) is followed by the second step (step
(ii)). In other words, a liquid mixture (MI) is produced by preparing a liquid clathrate
(LC) and subsequently mixing said liquid clathrate (LC) with an organometallic compound
(C). Accordingly the liquid clathrate (LC) is not treated any further before being
mixed with an organometallic compound (C). Further it is preferred that the liquid
clathrate (LC) is a solution according to the definition of this invention. By "not
treated" is meant that no such actions are carried, which might change either the
physical or chemical composition of the liquid clathrate (LC) of step (i). However,
e.g. washing or storing, where no such changes happen is possible between the steps
(i) and (ii), if needed.
[0046] According to the invention step (ii) is followed by step (iii). In other words, in
step (ii) a liquid mixture (MI) is produced and said liquid mixture (MI) is then in
step (iii) precipitated. Accordingly the requirement that step (iii) must subsequently
follow step (ii) may allow the storage of the liquid mixture (MI), but does not encompass
embodiments in which the liquid mixture (MI) is further treated in a way that any
physical or chemical changes occur in the liquid mixture (MI). Further it is preferred
that the liquid mixture (MI) itself is homogenous, i.e. is a solution according to
the definition of the invention.
[0047] The term "mixture" throughout the present application indicates that two or more
substances are present.
[0048] The term "solution" throughout the present application indicates that two or more
substances are homogenously mixed, e.g. is not a two phase system.
[0049] An "emulsion" according to this invention is a mixture of two liquid substances.
One substance, the dispersed phase, is dispersed in the other substance, the continuous
phase, as droplets.
[0050] The term "liquid" according to this invention indicates that a compound (including
a liquid) is liquid by normal pressure (1 atm) at room temperature, e.g. 20 to 30
°C.
[0051] A "liquid clathrate" is according to this invention a liquid which comprises, preferably
consists of, a lattice (L), i.e. the reaction product of aluminoxane (A) the organo-silicon
compound (OS) and a guest (G) enclosed therein. Liquid clathrates are as such well
known and for instance described by
Atwood, Jerry L. Dep. Chem., Univ. Alabama, Tuscaloosa, AL, USA. Editor(s): Robinson,
Gregory Heagward.; Coord. Chem. Alum. (1993), p.197-32.
Publisher: VCH, New York, N. Y CODEN: 59ECAI Conference; General Review written in
English. CAN 119:117290;,
John D. Holbrey, "Liquid clathrate formation in ionic liquid-aromatic mixtures", Chem.
Commun., 2003, pages 476 to 477, and
Scott K. Spear, Encyclopedia of Supramolecular Chemistry, 2001, pages 804 to 807. Accordingly the "liquid clathrate (LC)" is preferably a liquid in which the lattice
(L) constitutes the superstructure wherein the guest (G) is embedded. Preferably the
guest (G) stabilizes said superstructure. The guest (G) according to this invention
is the aromatic compound (AC).
[0052] A benefit of the solid catalyst system (CS) of the present invention over the metallocene/MAO
based catalysts of prior art is the low solubility in solvents, including solvents
used in polymerisation. The liquid clathrate (LC) is more stable than traditional
catalyst/co-catalyst structures and thus is less soluble in common media for olefin
polymerisation.
[0053] Thus one essential aspect of the invention is that the solid catalyst system (CS)
is obtained by the use of a liquid clathrate (LC).
[0054] The liquid clathrate (LC) of the present invention comprises
- (a) a lattice (L) being the reaction product of
(a1) aluminoxane (A) and
(a2) an organo-silicon compound (OS) being effective to form with the aluminoxane
(A) the lattice (L).
[0055] The lattice (L) is formed in presence of an aromatic compound (AC).
[0056] In the following the individual reactants are defined in more detail.
[0057] As stated above for the formation of the lattice (L) of the liquid clathrate (LC)
an organo-silicon compound (OS) is necessary which reacts with the aluminoxane (A).
The lattice is formed by reacting an organo-silicon compound (OS) with aluminoxane
(A) in presence of an aromatic compound (AC). It is preferred that the organo-silicon
compound (OS) doesn't comprise halogens, in particular doesn't comprise fluorine.
[0058] The preferred organo-silicon compound (OS) which is effective to form the lattice
(L) with the aluminoxane (A) can be selected from the group of hydrocarbyloxysilanes
of the formula R
3Si-O[-SiR
2-O]
n-SiR
3 or Si-[O-R]
4 wherein each R is, independently, a hydrocarbyl group having up to 20 carbon atoms
(e.g. linear or branched alkyl, cycloalkyl, aryl, aralkyl, alkylaryl) and n is 0 to
3; and hydrocarbylpolysiloxanes having from 2 to 8 silicon atoms in the molecule and
which are separated from each other by an oxygen atom such that there is a linear,
branched or cyclic backbone of alternating Si and oxygen atoms, with the remainder
of the four valence bonds of each of the silicon atoms individually satisfied by an
univalent hydrocarbyl group, R, as just defined. Preferably the hydrocarbyl groups,
R, are methyl, ethyl and phenyl. Examples of such organo-silicon compounds (OS) include
tetramethoxysilane, tetraethoxysilane, tetraphenoxysilane, methoxytrimethylsilane,
ethoxytrimethylsilane, hexamethyldisiloxane, hexaethyldisiloxane, hexaphenyldisiloxane,
tetramethyldiphenyldisiloxane, dimethyltetraphenyldisiloxane, hexamethylcyclotrisiloxane,
octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, octamethyltrisiloxane,
decamethyltetrasiloxane, dodecamethylpentasiloxane and tetradecamethylhexasiloxane,
1,3,3,5-tetramethyl-1,1,5,5-tetraphenyltrisiloxane, 1,1,1,5,5,5-hexamethyl3,3-diphenyltrisiloxane,
and 1,1,1,3,5,5,5-heptamethyl-3-phenyltrisiloxane.
[0059] Preferably the organo-silicon compound (OS) is selected from the group consisting
of octamethyltrisiloxane, decamethyltetrasiloxane, octamethylcyclotetrasiloxane, methoxytrimethylsilane,
tetraethoxysilane and 1,1,1,3,5,5,5-heptamethyl-3-phenyltrisiloxane. Preferably the
organo-silicon compound (OS) is octamethyltrisiloxane.
[0060] The aluminoxane (A) can be any conventional aluminoxane as is known in the art.
[0061] Aluminoxanes are commercially available or can be prepared according to prior art
literature for example by the hydrolysis of aluminium alkyls either by direct water
addition or by treatment with salt hydrates. There are a variety of methods for preparing
aluminoxane and modified aluminoxanes, examples of which are described in
US 4,665,208,
US 4,952,540,
US 5,091,352,
US 5,206,199,
US 5,204,419,
US 4,874,734,
US 4,924,018,
US 4,908,463,
US 4,968,827,
US 5,308,815,
US 5,329,032,
US 5,248,801,
US 5,235,081,
US 5,157,137,
US 5,103,031,
US 5,391,793,
US 5,391,529,
US 5,693,838,
US 5,731,253,
US 5,731,451 US 5,744,656,
EP-A-0 561 476,
EP-B1-0 279 586,
EP-A-0 594-218, and
WO 94/10180.
[0062] Aluminoxanes are also called alumoxanes.
[0063] Preferably, C
1 to C
10-alkylalumoxanes, particularly methylalumoxane or modified methylalumoxane, isobutylalumoxane,
e.g. TIBAO (tetraisobutylalumoxane) or HIBAO (hexaisobutylalumoxane) are used. More
preferably the aluminoxane (A) is methylalumoxane (MAO). MAO is commercially available
as 5 to 40 wt% solution in toluene.
[0064] A rapid catalytic activity depletion of the catalyst systems obtained by the precipitation
technology could be observed at high concentrations of organo-silicon compounds (OS).
The reason for this depletion, without being bound by theory, is the activity decreasing
effect of the organo-silicon compounds (OS) due to its Lewis-acidity. It has now surprisingly
been found that catalyst systems with high catalytic activity can be obtained in an
efficient manner when the liquid clathrate (LC) is prepared from a composition comprising
a specific ratio of aluminum (Al) from the aluminoxane (A) and the organo-silicon
compounds (OS).
[0065] Preferably the mol ratio between the organo-silicon compound (OS) and aluminum (Al)
of the aluminoxane (A) [(OS/(Al)] is equal or below 0.1, preferably in the range of
0.02 to 0.08, more preferably 0.02 to 0.07, most preferably 0.03 to 0.06, like 0.03
to 0.05. The mol-ratio is determined from the compounds provided in step (i) and relates
to the starting concentrations as provided in step (i) of the process described.
[0066] The aromatic compound (AC) can be any aromatic compound suitable as host for the
reaction of the organo-silicon compound (OS) with aluminoxane (A) from which the lattice
(L) of the liquid clathrate (LC) is formed. The aromatic compound (AC) is preferably
a liquid. Accordingly it is appreciated that the aromatic compound (AC) is an aromatic
hydrocarbon solvent, such as for example toluene, benzene, xylenes, ethylbenzene,
cumene, mesitylene or cymene. More preferably the aromatic compound (AC) is toluene.
- The liquid clathrate (LC) is obtainable by, preferably obtained by,
- (I) providing a mixture of an organo-silicon compound (OS), aluminoxane (A) and an
aromatic compound (AC)
- (II) obtaining a two phase system comprising an aromatic compound (AC) rich phase,
and a liquid clathrate (LC) rich phase,
- (III) separating the aromatic compound (AC) rich phase from the liquid clathrate (LC)
rich phase.
[0067] It is preferred that the process from which the liquid clathrate (LC) is obtainable
comprises formation of two stable immiscible organic layers, which remain intact such
that the aromatic compound (AC) rich phase can be separated from the liquid clathrate
(LC) rich phase.
[0068] The reaction is performed preferably under stirring and under inert atmosphere of
for example N
2 or Argon at temperatures between -20 to 70 °C, preferably between -10 to 60 °C, more
preferably between 0 to 50 °C, even more preferably between 10 to 40 °C, for example
20 to 30 °C. A person skilled in the art can easily determine experimentally a suitable
temperature for any of the organo-silicon compound (OS).
[0069] Preferably aluminoxane (A) in an aromatic compound (AC) is added to the organo silicon
compound (OS). However, it is appreciated that also the organo silicon compound (OS)
could be added to aluminoxane (A) in an aromatic compound (AC). Furthermore, it is
appreciated that also the organo silicon compound (OS) could be provided as a solution
in an aromatic compound (AC), in this case aluminoxane doesn't necessarily have to
be provided in an aromatic compound (AC).
[0070] In an embodiment the aromatic compound (AC) rich phase constitutes the upper layer
and the lower layer constitutes the liquid clathrate (LC) rich phase.
[0071] The upper phase is discarded and the lower liquid clathrate (LC) rich phase, i.e.
the liquid clathrate (LC) solution, is optionally washed before further use. The liquid
clathrate (LC) phase, i.e. the liquid clathrate (LC), is preferably washed once or
up to 5 times, preferably once to three times, with a (liquid) hydrocarbon compound,
preferably with the aromatic compound (AC) used for its preparation, like toluene.
[0072] The starting concentration of aluminoxane (A) in the aromatic compound (AC), like
toluene, usually ranges from 5 to 40 wt.-% solution.
[0073] Phase separation into the two phase system may occur immediately, i.e. by mixing
organo-silicon compound (OS), aluminoxane (A) and the aromatic compound (AC), or may
commence after a few hours, like 4 hours, or after one or more days, like after one
to three days. Separation can be improved if the mixture is cooled down to -20°C,
if needed. Most often the phase separation occurs immediately. E.g. by using 5 to
40 wt-% methylaluminoxane (MAO) solution in toluene separation occurs immediately.
However, phase separation time is dependent on the used aromatic compound (AC) and
aluminoxane (A) concentrations therein as well type and amount of organo-silicon compound
(OS).
[0074] Accordingly the reaction is characterized by the formation of a two phase system
comprising two stable immiscible organic layers, which remain intact such that the
upper layer, preferably the aromatic compound (AC) rich phase, can be separated from
the lower phase, preferably the liquid clathrate (LC) layer, i.e. the liquid clathrate
(LC).
[0075] For further processing the liquid clathrate (LC) phase, i.e. the liquid clathrate
(LC) solution, is separated from the upper solvent layer by conventional separation
techniques, for example by decantation, siphoning or draining.
[0076] Optionally the separated liquid clathrate (LC) phase can be washed before further
use. Preferably the liquid clathrate phase (LC) is washed once or up to 5 times, preferably
once to three times, with the aromatic compound (AC) used for its preparation.
[0077] The liquid clathrate (LC) as such is used in step (ii) and not for instance the liquid
clathrate (LC) together with the upper phase formed during the preparation of the
liquid clathrate (LC), i.e. the liquid clathrate (LC) solution.
[0078] In step (ii) the liquid clathrate (LC) is mixed with an organometallic compound (C)
and a liquid mixture (MI) is obtained, from which the solid catalyst system (CS) can
be precipitated (in step (iii)). Preferably the liquid mixture (MI) obtained is a
solution. Solution, as defined earlier in this application, indicates that two or
more substances are homogeneously mixed, e.g. it is not a two phase system.
[0079] The liquid clathrate (LC) is preferably reacted under stirring, with the organometallic
compound (C), under inert atmosphere of for example N
2 or Argon at temperatures between -20 to 70 °C, preferably between -10 to 60 °C, more
preferably between 0 to 50 °C, even more preferably between 10 to 40°C, for example
20 to 30 °C, to obtain the liquid mixture (MI) being a solution. A person skilled
in the art can easily determine experimentally a suitable temperature for any liquid
clathrate (LC) and the organometallic compound (C).
[0080] According to the present invention it has been found that not only the mol-ratio
of aluminum (Al) from the aluminoxane (A) to the organo-silicon compounds (OS) has
a strong influence on the catalytic activity of the catalyst system (CS) obtainable,
but also the mol-ratio between aluminum (Al) of the aluminoxane (A) and transition
metal (M) of the organometallic compound (C). Accordingly it is preferred that the
mol-ratio between aluminum (Al) of the aluminoxane (A) and transition metal (M) of
the organometallic compound (C) [(Al)/(M)] is ≤ 600, more preferred ≤ 500, like below
450. Furthermore, it is preferred that the mol-ratio between aluminum (Al) of the
aluminoxane (A) and transition metal (M) of the organometallic compound (C) [(Al)/(M)]
is ≥ 50 , more preferred ≥100, even more preferred ≥ 150. In other words it is preferred
that the mol-ratio between aluminum (Al) of the aluminoxane (A) and transition metal
(M) of the organometallic compound (C) [(Al)/(M)] is in a range from 50 to 600, preferably
in a range from 100 to 500, like 150 to 450.
[0081] The mol-ratio is determined from the compounds provided in steps (i) and (ii) and
relates to the starting concentrations as provided in steps (i) and (ii) of the process
described.
[0082] Furthermore, it is preferred that essentially on the same level mol-ratio determined
from the compounds provided in step (ii) is also present in the catalyst system (CS)
obtained from the inventive process.
[0083] As is commonly known the catalytic activity of the catalyst system (CS) is normally
higher with lower mol-ratio between aluminum (Al) of the aluminoxane (A) and transition
metal (M) of the organometallic compound (C) [(Al)/(M)].
[0084] In the present invention it has been found that clathrating agent has a clear impact
on catalyst activity.
[0085] Still in a more preferred embodiment the organometallic compound (C) used in the
invention is of formula (II)
(L)
2RMX
2 (II)
wherein
"M" is zirconium (Zr) or hafnium (Hf),
each "X" is independently selected from halogen, C1 to C6 alkyl, C5 to C6 cycloalkyl, C1 to C6 alkoxy, phenyl and benzyl groups,
each "L" is independently a cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl,
which can be independently substituted or unsubstituted, preferably at least one organic
ligand (L), preferably both organic ligands (L), comprise one or more substituents
independently selected from C1 to C20 hydrocarbyl or silyl groups, which optionally contain one or more heteroatoms selected
from groups 14 to 16 (IUPAC 2007) and/or are optionally substituted by halogen atom(s),
"R" is a divalent bridge selected from -R'2C-, -R'2Si-, wherein each R' is independently a hydrogen atom, C1 to C20 alkyl, C2 to C10 cycloalkyl, C6 to C20 aryl, C7 to C20 arylalkyl or C7 to C20 alkylaryl.
[0086] In the step (iii) the solid catalyst system (CS) is precipitated by adding a saturated
aliphatic compound to the liquid mixture (MI) obtained from step (ii).
[0087] The precipitation is performed preferably under stirring and under inert atmosphere
of for example N
2 or Argon at temperatures between 10 and 40 °C, preferably between 15 and 35 °C and
more preferably between 20 and 30 °C.
[0088] Although the use of ambient temperatures is most convenient, i.e. from 10 to 30°C,
some compounds require elevated or lower temperatures. A person skilled in the art
can easily determine experimentally a suitable temperature depending on the type of
aromatic compound used in the process.
[0089] The solid catalyst system (CS) is obtainable in a convenient and sustainable manner.
The liquid mixture (MI), e.g. the liquid mixture (MI) being a solution, enables a
person skilled in the art to accomplish precipitation with solvents in step (iii),
which are convenient with respect to economic and ecologic considerations. Such solvents
include saturated aliphatic compounds.
[0090] Accordingly in the instant process precipitation in step (iii) is accomplished by
removing the aromatic compound (AC) from the liquid mixture of liquid clathrate (LC)
and organometallic compound. The removal can be effected by different techniques.
[0091] According to the invention the precipitation in step (iii) is accomplished by adding
a saturated aliphatic compound to the liquid mixture (MI) which causes a dilution
effect for the aromatic compound (AC) leading to the precipitation of the catalyst
system (CS).
[0092] It is a finding of the present invention that saturated aliphatic compounds can be
employed in the process described for precipitating the catalyst system (CS) from
the liquid mixture (MI). Preferably the aliphatic compound is selected from the group
consisting of C
1 to C
20 alkanes, C
4 to C
12 cycloalkanes and combinations thereof, preferably C
3 to C
12 alkanes, like C
5 to C
10 alkanes. More preferably the aliphatic compound is selected from the group consisting
of n-pentane, n-hexane, n-heptane, n-octane, and mixtures thereof. Even more preferably
the aliphatic compound is n-pentane.
[0093] In a preferred embodiment the aromatic compound (AC) is toluene and/or the saturated
aliphatic compound is selected from the group consisting of n-pentane, n-hexane, n-heptane,
n-octane, and mixtures thereof. It is particularly preferred that the aromatic compound
(AC) is toluene and the saturated aliphatic compound is n-pentane.
[0094] Further the saturated aliphatic compound, preferably n-pentane, is also inert in
relation to the compounds of the solid catalyst system to be produced. The term "inert
in relation to the compounds" means herein that the aliphatic compound, preferably
the n-pentane, is chemically inert, i.e. undergoes no chemical reaction with the solid
catalyst system (CS) and the compounds provided besides the aromatic compound (AC)
for preparing the catalyst system (CS), i.e. the organo-silicon compound (OS) and
the aluminoxane (A)).
[0095] The addition of the saturated aliphatic compound to the liquid mixture (MI) can be
accomplished as known in the art, for instance by pouring the saturated aliphatic
compound into the liquid mixture (MI).Typically after addition the obtained mixture
is agitated (stirred) to facilitate the formation of the solid catalyst system (CS)
particles. No specific temperature is needed. Precipitation can be accomplished in
a broad temperature range, like 2 to 80 °C. Optimal temperature is dependent on the
individual components employed. The optimal precipitating temperature can vary e.g.
from below 10 to above 50 °C. Very good results are achievable at temperatures between
10 and 40 °C, or between 15 and 35 °C, like 20 to 30 °C.
[0096] Alternatively the liquid mixture (MI) is introduced very fast into the saturated
aliphatic compound, like spray-technology. This way of forming the solid catalyst
system (CS) particles has the advantage that very spherical particles are obtained
compared to simple pouring technique.
[0097] Optionally the process of the present invention comprises a fourth step (step (iv)),
which is recovering the particles of the solid catalyst system (CS). In other words
particles of the solid catalyst system (CS) which is obtained by the precipitation
step (iii) may be separated and recovered by any procedure known in the art. For example,
the solid catalyst particles in the suspension may be filtered. Other commonly known
methods for isolating are decanting, centrifuging and flotation. The particles of
solid catalyst system (CS) may then be optionally washed and/or dried to remove any
solvent residuals present in the particles. The washing and/or drying of the catalyst
particles may be carried out in any manner conventional in the art.
[0098] Furthermore, each of the steps, i.e. steps (i) to (iv), is preferably accomplished
at a temperature in the range of 10 to 30 °C, preferably in the range of 20 to 30
°C.
[0099] The instant process leads to a solid catalyst system (CS), in particular to solid
catalyst system (CS) without any need of using external support material. In other
words a process is described wherein the solid catalyst system (CS) is unsupported,
i.e. during the process no carrier material is added.
[0100] From the process described a solid catalyst system (CS) can be obtained.
[0101] In other words the present invention is also directed at a solid catalyst system
(CS) as described in the process of the invention.
[0102] In a preferred embodiment the invention is also directed at a solid catalyst system
(CS) comprising the reaction product of
- (a) a liquid clathrate (LC) obtained by mixing an aluminoxane (A), an aromatic compound
(AC) and an organo-silicon compound (OS), wherein the mol-ratio between the organo-silicon
compound (OS) and aluminum (Al) of the aluminoxane (A) [(OS)/(Al)] is below 0.1 and
- (b) an organometallic compound (C), said organometallic compound (C) is of formula
(I)
(L)mRnMXq (I)
wherein
"M" is a transition metal (M) of Group 3 to 10 of the Periodic Table (IUPAC 2007),
each "X" is independently a monoanionic ligand, such as σ-ligand,
each "L" is independently an organic ligand which coordinates to the transition metal
(M),
"R" is a bridging group linking said organic ligands (L),
"m" is 1 or 2 or 3, preferably 2,
"n" is 0, 1 or 2, preferably 1,
"q" is 1, 2 or 3, preferably 2,
m+q is equal to the valency of the transition metal (M).
[0103] In a more preferred embodiment the invention is also directed at a solid catalyst
system (CS) comprising the reaction product of
- (a) a liquid clathrate (LC) obtained by mixing an aluminoxane (A), an aromatic compound
(AC) and an organo-silicon compound (OS), wherein the mol-ratio between the organo-silicon
compound (OS) and aluminum (Al) of the aluminoxane (A) [(OS)/(Al)] is below 0.08 and
- (b) an organometallic compound (C) of formula (II)
(L)2RMX2 (II)
wherein
"M" is zirconium (Zr) or hafnium (Hf),
each "X" is independently selected from halogen, C1 to C6 alkyl, C5 to C6 cycloalkyl, C1 to C6 alkoxy, phenyl and benzyl groups,
each "L" is independently a cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl,
which can be independently substituted or unsubstituted, preferably at least one organic
ligand (L), preferably both organic ligands (L), comprise one or more substituents
independently selected from C1 to C20 hydrocarbyl or silyl groups, which optionally contain one or more heteroatoms selected
from groups 14 to 16 and/or are optionally substituted by halogen atom(s),
"R" is a divalent bridge selected from -R'2C-, -R'2Si-, wherein each R' is independently a hydrogen atom, C1 to C20 alkyl, C2 to C10 cycloalkyl.
[0104] All preferred embodiments of reactants as disclosed above are valid to the preparation
of catalyst system as well to catalyst system as such.
[0105] Furthermore, a solid catalyst system (CS) is preferred, wherein said solid catalyst
system (CS) is obtained by mixing said liquid clathrate (LC) with the organometallic
compound (C) obtaining a liquid mixture (MI), wherein further the solid catalyst system
(CS) is precipitated from said liquid mixture (MI) by adding a saturated aliphatic
compound to said liquid mixture (MI).
[0106] In an embodiment a solid catalyst system (CS) is preferred, wherein mol-ratio between
the aluminum (Al) of the aluminoxane (A) and the transition metal (M) of the organometallic
compound (C) [(Al)/(M)] is ≤ 600, more preferred ≤ 500, even more preferred ≤ 450.
Furthermore, it is preferred that the mol-ratio between aluminum (Al) of the aluminoxane
(A) and transition metal (M) of the organometallic compound (C) [(Al)/(M)] is ≥ 50,
more preferred ≥100, even more preferred ≥ 150. In other words it is preferred that
the mol-ratio between aluminum (Al) of the aluminoxane (A) and transition metal (M)
of the organometallic compound (C) [(Al)/(M)] is in a range from 50 to 600, preferably
in a range from 100 to 600, like 120 to 500.
[0107] The present invention is also directed at a solid catalyst system (CS) prepared according
to above process, wherein the organo-silicon compound (OS) is preferably selected
from the group consisting of octamethyltrisiloxane, decamethyltetrasiloxane,
octamethylcyclotetrasiloxane, methoxytrimethylsilane, tetraethoxysilane, tetramethoxysilane,
tetraphenoxysilane, ethoxytrimethylsilane, hexamethyldisiloxane, hexaethyldisiloxane,
hexaphenyldisiloxane, tetramethyldiphenyldisiloxane, dimethyltetraphenyldisiloxane,
hexamethylcyclotrisiloxane, octaphenylcyclotetrasiloxane,, dodecamethylpentasiloxane
and tetradecamethylhexasiloxane, 1,3,3,5-tetramethyl-1,1,5,5-tetraphenyltrisiloxane,
1,1,1,5,5,5-hexamethyl3,3-diphenyltrisiloxane, 1,1,1,3,5,5,5-heptamethyl-3-phenyltrisiloxane;
and/or the aromatic compound (AC) is toluene; and/or the saturated aliphatic compound
is selected from the group consisting of n-pentane, n-hexane, n-heptane, n-octane,
and mixtures thereof.
[0108] Preferred is a solid catalyst system (CS), wherein the liquid mixture (MI) is homogeneous;
and the solid catalyst system (CS) is unsupported, i.e. during the process no carrier
material is added.
[0109] Thus, the present invention is also directed at the use of a solid catalyst system
(CS) for the preparation of a polymer, like polyethylene and /or polypropylene.
[0110] Furthermore, the present invention is also directed at the preparation of a polymer,
like a polypropylene or polyethylene, by polymerising monomer units, like propylene
and/or ethylene in the presence of a solid catalyst system (CS) as defined above.
[0111] Finally, the present invention is also directed at the preparation of a polymer,
like a polypropylene, comprising the steps of preparing a solid catalyst system (CS)
according to the process described, using said solid catalyst system (CS) in a polymerisation
process, thereby obtaining the polymer, like the polypropylene.
[0112] Polymerisation of olefins, like propylene and ethylene optionally with other comonomers,
like C
2 to C
8, e.g. ethylene, butylenes or hexene, can be carried out in one or more polymerisation
steps comprising solution, slurry/liquid and gas phase polymerisation or any combination
thereof. Polymerisation configuration can comprise one or more polymerisation reactors
or combination of reactors.
FIGURES
[0113]
- Fig. 1:
- Catalyst activity of Polymerisation examples 2, 4 and 5 (Catalyst Examples 2, 5 and
6, resp.) obtained by precipitation with pentane as a function of [(Al)/(Zr)] compared
to catalyst activity of Comparative Example 1 obtained by precipitation in silicon
oil as a function of mol ratio [(Al)/(Zr)].
- Fig. 2:
- Catalyst activity of Polymerisation examples P3, P2 and P1 (Catalyst Examples 4, 2
and 1, resp) obtained by precipitation with pentane as a function of mol ratio [(OS)/(Al)].
EXAMPLES
[0114] The following definitions of terms and determination methods apply for the above
general description of the invention as well as to the below examples, unless otherwise
defined.
1. Measuring Methods:
[0115] MFR2 (230 °C) is measured according to ISO 1133 (230 °C, 2.16 kg load) for polypropylene.
[0116] MFR2 (
190 °C) is measured according to ISO 1133 (190 °C, 2.16 kg load) for polyethylene.
ICP analysis
[0117] The elemental analysis of a catalyst was performed by taking a solid sample of mass,
M, cooling over dry ice. Samples were diluted up to a known volume, V, by dissolving
in nitric acid (HNO
3, 65 %, 5 % of V) and freshly deionised (DI) water (5 % of V). The solution was then
diluted with DI water up to the final volume, V, and left to stabilise for two hours.
[0118] The analysis was run at room temperature using a Thermo Elemental iCAP 6300 Inductively
Coupled Plasma - Optical Emmision Spectrometer (ICP-OES) which was calibrated using
a blank (a solution of 5 % HNO
3, 3 % HF in DI water), and 6 standards of 0.5 ppm, 1 ppm, 10 ppm, 50 ppm, 100 ppm
and 300 ppm of Al, with 0.5 ppm, 1 ppm, 5 ppm, 20 ppm, 50 ppm and 100 ppm of Hf and
Zr in solutions of 5 % HNO
3, 3 % HF in DI water.
[0119] Immediately before analysis the calibration is 'resloped' using the blank and 100
ppm Al, 50 ppm Hf, Zr standard, a quality control sample (20 ppm Al, 5 ppm Hf, Zr
in a solution of 5 % HNO
3, 3 % HF in DI water) is run to confirm the reslope. The QC sample is also run after
every 5
th sample and at the end of a scheduled analysis set.
[0120] The content of hafnium was monitored using the 282.022 nm and 339.980 nm lines and
the content for zirconium using 339.198 nm line. The content of aluminium was monitored
via the 167.079 nm line, when Al concentration in ICP sample was between 0-10 ppm
(calibrated only to 100 ppm) and via the 396.152 nm line for Al concentrations above
10 ppm.
[0121] The reported values are an average of three successive aliquots taken from the same
sample and are related back to the original catalyst by inputting the original mass
of sample and the dilution volume into the software.
Molecular weight averages, molecular weight distribution (Mn, Mw, Mz, MWD)
[0123] For a constant elution volume interval ΔV
i, where A
i, and M
i are the chromatographic peak slice area and polyolefin molecular weight (MW), respectively
associated with the elution volume, V
i, where N is equal to the number of data points obtained from the chromatogram between
the integration limits.
[0124] A high temperature GPC instrument, equipped with either infrared (IR) detector (IR4
or IR5 from PolymerChar (Valencia, Spain) or differential refractometer (RI) from
Agilent Technologies, equipped with 3 x Agilent-PLgel Olexis and 1x Agilent-PLgel
Olexis Guard columns was used. As the solvent and mobile phase 1,2,4-trichlorobenzene
(TCB) stabilized with 250 mg/L 2,6-Di tert butyl-4-methyl-phenol) was used. The chromatographic
system was operated at 160 °C and at a constant flow rate of 1 mL/min. 200 µL of sample
solution was injected per analysis. Data collection was performed using either Agilent
Cirrus software version 3.3 or PolymerChar GPC-IR control software.
[0125] The column set was calibrated using universal calibration (according to ISO 16014-2:2003)
with 19 narrow MWD polystyrene (PS) standards in the range of 0.5 kg/mol to 11 500
kg/mol. The PS standards were dissolved at room temperature over several hours. The
conversion of the polystyrene peak molecular weight to polyolefin molecular weights
is accomplished by using the Mark Houwink equation and the following Mark Houwink
constants:
| KPS = 19 x 10-3 mL/g, |
PS = 0.655 |
| KPE = 39 x 10-3 mL/g, |
PE = 0.725 |
| KPP = 19 x 10-3 mL/g, |
PP = 0.725 |
[0126] A third order polynomial fit was used to fit the calibration data.
[0127] All samples were prepared in the concentration range of 0.5 to 1.0 mg/ml and dissolved
at 160 °C for 2.5 hours for polypropylene or 3 hours for polyethylene under continuous
gentle shaking.
Catalyst productivity
[0128] The catalyst productivity is defined as the amount of polymer in kilograms obtained
per gram solid catalytic component used (kg polymer / g catalyst).
Catalyst activity
[0129] The catalyst activity is defined as the amount of polymer in kilograms obtained per
gram solid catalytic component and polymerisation time (kg polymer/g catalyst x time)
2. Chemicals:
Methylaluminoxane (MAO)
[0130] MAO was purchased from Chemtura as 30 wt-% solution in toluene.
[0131] Octamethyltrisiloxane (OMTS) was purchased from Aldrich (Octamethyltrisiloxane Mw 236,53 g/mol,
CAS 107-51-7) and distilled from CaH
2.
[0132] 1,3,3,5-tetramethyl-1,1,5,5-tetraphenyltrisiloxane (OS2), CAS 3982-82-9
Triisobutylaluminium (TIBA)
[0133] TIBA was purchased from Crompton (TIBA,
CAS 100-99-2).
Triethylaluminum (TEA)
[0134] TEA was purchased from Crompton. (TEA
CAS 97-93-8)
Hydrogen
[0135] Hydrogen was purchased from AGA and purified according to standard methods before
use.
Ethylene, propylene and hexene
[0136] Ethylene, propylene and hexene were provided from Borealis in polymerisation grade
and purified according to standard methods.
Pentane
[0137] Pentane was degassed by sparging argon for 30 min and stored over molecular sieves.
Toluene
[0138] Toluene was purified according to the standard purification method.
Metallocene A
[0139] rac-methyl(cyclohexyl)silanediyl-
bis[(2-methyl-4-(4-tert-butylphenyl)indenyl]zirconium dichloride (
CAS no 888227-55-2,
WO2006/060544) purchased from commercial source,

Metallocene B
3. Preparation-of the catalyst system (CS)
Example 1
[0141] All chemicals were handled and the steps were preformed under inert gas atmosphere
(N
2 or Ar gas)
Preparation of liquid clathrate
[0142] 10.3 mmol MAO (30 wt % in toluene) was added to 1.03 mmol OMTS (mol-ratio between
OMTS and aluminum (Al) of the aluminoxane (A) [OMTS/(Al)] = 0.1). The solution was
stirred for 12 h at room temperature (20 to 25 °C). Stirring was stopped and separation
of the solution into two phases was clearly seen. The upper phase (toluene) was removed
and the lower phase (clathrate). The lower phase (clathrate) was washed twice by adding
1 mL toluene for each washing step and lower phase was isolated.
Preparation of the mixture liquid (MI)
[0143] 0.041 mmol of Metallocene A was added to the clathrate phase obtained from the preparation
of the liquid clathrate. A solution with a mol-ratio between aluminum (Al) of the
aluminoxane (A) and zirconium (Zr) of the Metallocene A of [(Al)/(M)] = 250 was obtained.
The solution was stirred for 2 h at room temperature (20 to 25 °C).
Precipitation of the catalyst system
[0144] Subsequently 4.0 mL pentane was added and the solution was stirred for 12 h at room
temperature (20 to 25 °C). A solid precipitate was formed and the liquid was decanted.
The residue of the liquid was removed with a pipette. The solid precipitate was washed
twice by adding 3 mL pentane for each washing step and washing liquids were discarded.The
solid was dried in vacuum at 0.03 mbar for 30 to 40 minutes. The solid was sieved
through a 50 µm sieve to yield 400 mg of the catalyst as a pink powder.
Example 2
[0145] Example 2 was prepared as described in Example 1 but instead of 1.03 mmol OMTS only
0.515 mmol OMTS (mol-ratio between OMTS and aluminum (Al) of the aluminoxane (A) [OMTS/(Al)]
= 0.05) was added. 390 mg of product were collected in the form of pink powder. ICP
analysis showed 37.9 wt.-% Al and 0.61 wt.-% Zr content.
Example 3
[0146] Example 3 was prepared as described in Example 2 but instead of Metallocene A Metallocene
B was added. 370 mg of product were collected in the form of yellowish powder. ICP
analysis showed 35.1 wt.-% Al and 0.75 wt.-% Zr content.
Example 4
[0147] Example 4 was prepared as described in Example 1 but instead of 1.03 mmol OMTS only
0.206 mmol OMTS (mol-ratio between OMTS and aluminum (Al) of the aluminoxane (A) [OMTS/(Al)]
= 0.02 was added. 390 mg of product were collected in the form of pink powder. ICP
analysis showed 36.3 wt.-% Al and 0.91 wt.-% Zr.
Example 5
[0148] Example 5 was prepared as described in Example 2 but the amount of metallocene was
0,0205 mmol, thus the mol-ratio between aluminum (Al) of the aluminoxane (A) and zirconium
(Zr) of the Metallocene A was increased from [(Al)/(M)] = 250 to [(Al)/(M)] = 500
in the feed. 370 mg of product were collected in the form of pink powder. ICP analysis
showed 31.9 wt.-% Al and 0.32 w.-% Zr content.
Example 6
[0149] Example 6 was prepared as described in Example 2 but the amount of metallocene was
only 0,0137 mmol, thus the mol-ratio between aluminum (Al) of the aluminoxane (A)
and zirconium (Zr) of the Metallocene A was increased from [(Al)/(M)] = 250 to [(Al)/(M)]
= 750 in the feed. 280 mg of product were collected in the form of pink powder. ICP
analysis showed 37.2 wt.-% Al and 0.21 wt.-% Zr content
Example 7
[0150] Example 7 was prepared as described in Example 2 but instead of using OMTS (0.515
mmol) 0.515 mmol of 1,3,3,5-tetramethyl-1,1,5,5,-tetraphenyltrisiloxane (OS2) was
used. In other words, an alternative organosilicon compound was used. 250 mg of product
were collected in the form of pink powder. ICP analysis showed 35.4 wt.-% Al and 1.11
wt.-% Zr content.
Comparative Example 1
[0151] Comparative Example 1 is an catalyst system comprising Metallocene A, a mol-ratio
between aluminum (Al) of the aluminoxane (A) and zirconium (Zr) of the Metallocene
A of [(Al)/(M)] = 500 and a mol-ratio between OMTS and aluminum (Al) of the aluminoxane
(A) [OMTS/(Al)] = 0.05, which was prepared by the silicon oil route by the precipitation
method according to the principles and examples 1 to 2 as described in
EP 2 386 582.
Comparative Example 2
[0152] Catalyst was prepared by adding metallocene B to MAO in a mol-ratio between aluminum
(Al) of the aluminoxane (A) and zirconium (Zr) [(Al)/(M)] = 250 without using any
chlatrating agent. Catalyst solution was precipitated with pentane according to the
example 3. Due to high solubility of MAO-metallocene catalyst, only a trace amount
of solid product were obtained, only 30 mg of the catalyst were isolated compared
to the yield of 370 mg in example 3 run on the same scale. Thus, it was clear that
catalyst preparation using precipitation method without any clathrating agent does
by no means make any sense.
Comparative Example 3
[0153] Catalyst was prepared according to the example 2 except for the fact that the upper
layer has not been removed upon the formation of the liquid clathrate mixture, and
metallocene A was added to a heterogeneous liquid-liquid mixture. After stirring for
12 hours, pentane was added and the work-up was carried out as in the Example 2. The
catalyst was isolated in the form of pink powder (0.4 g). ICP analysis showed 37.4
wt.-% Al and 0.44 wt.-% Zr content.
4. Preparation of polymers from the catalyst systems (CS)
Polypropylene
[0154] A 5 liter stainless steel reactor was used for propylene polymerisations. 1100 g
of liquid propylene (Borealis polymerisation grade) was fed to the reactor. 0.2 ml
triethylaluminum was fed as a scavenger and 15 mmol hydrogen as chain transfer agent.
Reactor temperature was set to 20 °C. Desired amount of catalyst (20 to 28 mg) was
flushed into to the reactor in 5 ml PFC with nitrogen overpressure. After 5 minutes
the reactor was heated to 70 °C in a period of about 15 minutes. The polymerisation
is stopped after 60 minutes by venting the reactor and flushing with nitrogen before
the polymer is collected.
[0155] The catalyst activity was calculated on the basis of the 60 minutes period according
to the following formula:

Polyethylene
[0156] Polymerisation experiments were carried out in PPR (Parallel Pressure Reactor) which
are stirred reactors each reactor having a volume of 21 mL. Reactor was conditioned
by purging it with dry nitrogen for 6 hours at 80 °C. Pre-weighed disposable glass
vials and disposable flat stirring paddles were fitted into the reactor. Reactor was
then closed and thoroughly flushed with propylene prior the experiment. 5 µmol of
freshly made TIBA solution (200 µL of 25 mM solution in heptane) was added through
a valve to all 48 reactors. Reactors were pressurised to 278 kPa (40 psi) with ethylene
to ensure that all the individual reactors were maintaining pressure. Stirring speed
was the set up to 800 rpm for all reactors and the temperature increased to 80 °C.
Once the temperature was stable the reactors were pressurised to 434 kPa (63 psi)
with ethylene. The reactor temperatures were maintained at 80 °C by computer control
during the experiment. Catalyst slurries were made by mixing catalysts with dodecane
so that concentration of the resulting slurry was 12 25 mg/mL. Vortexing of 1200 rpm
was applied to ensure formation of homogeneous slurry. Once the reactor temperature
was stabilized catalysts were added into the reactors though a valve. Pressure in
the reactors was maintained at 434 kPa (63 psi) during the experiment. Polymerisations
were continued for 60 minutes after which the reaction was terminated by addition
of CO2 (20%/80% of CO
2/N
2 was used to pressurize the reactors to 2.9 MPa). Once cooled, the reactor was degassed
and flushed repeatedly with nitrogen.
[0157] The catalyst activity was calculated on the basis of the 60 minutes period according
to the following formula: Catalyst Activity (kg/(g(cat) h)) amount of polymer produced
(kg)catalyst loading (g) polymerisation time (h)
[0158] The catalyst activity was calculated on the basis of the 60 minutes period according
to the following formula: Catalyst Activity (kg/(g(cat) h)) amount of polymer produced
(kg)catalyst loading (g) polymerisation time (h)

Polyethylene 1-Hexene Copolymer
[0159] The polymerisation was carried out in an autoclave reactor (2L) purchased from Buchi,
equipped with a paddle stirrer and a continuous ethylene supply.
[0160] The reactor was purged with N
2 and filled with propane (900 ml) and 150 g ethene (Borealis polymerisation grade)
and 25 mL 1-hexene (Borealis polymerisation grade). 1.5 ml of TIBA was fed as a scavenger
in 5 mL of dry and degassed pentane. The temperature was raised to 60 °C and then
the desired amount of catalyst was flushed into the reactor with nitrogen overpressure.
The temperature was subsequently raised to 80 °C. The polymerisation is stopped after
60 minutes by venting the reactor and flushing with nitrogen before the polymer was
collected.
[0161] The catalyst activity was calculated on the basis of the 60 minutes period according
to the following formula:

5. Determining the catalytic activity of the catalyst system (CS)
[0162]
Table 1: Polymerisation results of polypropylene
| PE |
CE |
MC |
[OMTS/(Al)] |
Catalytic activity |
MFR2 |
| |
|
|
[-] |
[kg PP/g cat*h] |
[g/10min] |
| P1 |
Ex. 1 |
A |
0.10 |
4.1 |
3.7 |
| P2 |
Ex. 2 |
A |
0.05 |
24.6 |
3.6 |
| P3 |
Ex. 4 |
A |
0.02 |
27.2 |
2.9 |
| P4 |
Ex. 5 |
A |
0.05 |
14.6 |
3.7 |
| P5 |
Ex. 6 |
A |
0.05 |
5.3 |
N/A |
| P6 |
Ex 7 |
A |
0.05* |
54.1 |
4.7 |
| CP1 |
Comp. Ex. 1 |
A |
0.05 |
0.1 |
N/A |
| CP2 |
Comp. Ex. 3 |
A |
0.05 |
1.6 |
N/A |
*OS2 used instead of OMTS
PE Polymerisation example
CE Catalyst example
MC Metallocene |
Table 2: Polymerisation results of polyethylene (homoPE), data from PPR
| PE |
CE |
MC |
[OMTS/(Al)] |
Catalytic activity |
Mw |
| |
|
|
[-] |
[kg PE/g cat*h] |
[kg/mol] |
| P7 |
Ex. 1 |
A |
0.1 |
6.0 |
572 |
| P8 |
Ex. 2 |
A |
0.05 |
6.4 |
441 |
| P9 |
Ex. 3 |
B |
0.05 |
1.3 |
231 |
PE Polymerisation example
CE Catalyst example
MC Metallocene |
Table 3: Polymerisation results of polyethylene/1-hexene copolymer
| PE |
CE |
MC |
Catalytic activity |
MFR2 |
Hexene |
| |
|
|
[kg PE/g cat*h] |
[g/10min] |
[wt.-%] |
| P10 |
Ex. 3 |
B |
11.2 |
2.2 |
1.7 |
PE Polymerisation example
CE Catalyst example
MC Metallocene |
[0163] The examples provide that the catalytic activity in polymerisation process significantly
exceeded the catalytic activity of solid unsupported catalyst systems obtained by
the precipitation technology known from the state. Further, it has been shown that
precipitation of catalyst without any chlathrating agent does not lead to a solid
catalyst in any reasonable yield.
1. Process for the preparation of a solid catalyst system (CS) comprising the steps of
(i) preparing a liquid clathrate (LC) comprising a mixing of an aluminoxane (A), an
aromatic compound (AC) and an organo-silicon compound (OS), wherein the mol-ratio
between the organo-silicon compound (OS) and aluminum (Al) of the aluminoxane (A)
[(OS)/(A1)] is equal or below 0.1,
(ii) mixing said liquid clathrate (LC) with an organometallic compound (C) obtaining
a liquid mixture (MI), wherein the liquid mixture (MI) is homogeneous,
(iii) precipitating the solid catalyst system (CS) out of said liquid mixture (MI)
by adding a saturated aliphatic compound to said liquid mixture (MI),
(iv) optionally recovering particles of the solid catalyst system (CS),
wherein during the process no carrier materiel is added.
2. Process according to claim 1, wherein said organometallic compound (C) is of formula
(I)
(L)
mR
nMX
q (I)
wherein
"M" is a transition metal (M) of group 3 to 10 of the Periodic Table (IUPAC 2007),
each "X" is independently a mono anionic ligand, like a σ-ligand,
each "L" is independently an organic ligand which coordinates to the transition metal
"M",
"R" is a bridging group linking said organic ligands (L),
"m" is 1, 2 or 3, preferably 2,
"n" is 0, 1 or 2, preferably 1,
"q" is 1, 2 or 3, preferably 2,
m+q is equal to the valency of the transition metal (M).
3. Process according to claim 1 or 2, wherein the mol-ratio between the aluminum (Al)
of the aluminoxane (A) and the transition metal (M) of the organometallic compound
(C) [(Al)/(M)] is in the range of 50 to 600.
4. Process according to any one of the preceding claims, wherein the organo-silicon compound
(OS) is selected from the group consisting of octamethyltrisiloxane, decamethyltetrasiloxane,
octamethylcyclotetrasiloxane, methoxytrimethylsilane, tetraethoxysilane and 1,1,1,3,5,5,5-heptamethyl-3-phenyltrisiloxane.
5. Process according to any one of the preceding claims, wherein
(a) the aromatic compound (AC) is toluene;
and/or
(b) the saturated aliphatic compound is selected from the group consisting of n-pentane,
n-hexane, n-heptane, n-octane, and mixtures thereof.
6. Process according to any one of the preceding claims, wherein
(a) step (i), i.e. the mixing of aluminoxane (A), an aromatic compound (AC) and an
organo-silicon compound (OS), is accomplished at a temperature in the range of -20
to 70 °C, preferably in the range of 10 to 40 °C
(b) step (ii), i.e. the mixing of the liquid clathrate (LC) with an organometallic
compound (C) is accomplished at a temperature in the range of 0 to 50 °C, preferably
in the range of 20 to 30 °C.
7. Process according to any one of the preceding claims, wherein the organometallic compound
(C) is formula (II)
(L)
2RMX
2 (II)
wherein
"M" is zirconium (Zr) or hafnium (Hf),
each "X" is independently selected from halogen, C1 to C6 alkyl, C5 to C6 cycloalkyl, C1 to C6 alkoxy, phenyl and benzyl groups,
each "L" is independently a cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl,
which can be independently substituted or unsubstituted, preferably at least one organic
ligand (L), preferably both organic ligands (L), comprise one or more substituents
independently selected from C1 to C20 hydrocarbyl or silyl groups, which optionally contain one or more heteroatoms selected
from groups 14 to 16 and/or are optionally substituted by halogen atom(s),
"R" is a divalent bridge selected from -R'2C-, -R'2Si-, wherein each R' is independently a hydrogen atom, C1 to C20 alkyl, C2 to C10 cycloalkyl.
8. Solid catalyst system (CS) comprising the reaction product of
(a) a liquid clathrate (LC) obtained by mixing an aluminoxane (A), an aromatic compound
(AC) and an organo-silicon compound (OS), wherein the mol-ratio between the organo-silicon
compound (OS) and aluminum (Al) of the aluminoxane (A) [(OS)/(Al)] is below 0.08,
and
(b) an organometallic compound (C), said organometallic compound (C) is of formula
(I)
(L)mRnMXq (I)
wherein
"M" is a transition metal (M) of Group 3 to 10 of the Periodic Table (IUPAC 2007),
each "X" is independently a σ-ligand,
each "L" is independently an organic ligand which coordinates to the transition metal
(M),
"R" is a bridging group linking said organic ligands (L),
"m" is 1, 2 or 3, preferably 2,
"n" is 0, 1 or 2, preferably 1,
"q" is 1, 2 or 3, preferably 2,
m+q is equal to the valency of the transition metal (M),
wherein said solid catalyst system (CS) is obtained by mixing said liquid clathrate
(LC) with the organometallic compound (C) obtaining a liquid mixture (MI), wherein
further the solid catalyst system (CS) is precipitated from said mixture (MI) by adding
a saturated aliphatic compound to said mixture (MI), and wherein the mixture (MI)
is homogeneous and the solid catalyst system (CS) is unsupported, i.e. during the
process no carrier material is added.
9. Solid catalyst system (CS) according to claim 8, wherein the mol-ratio between the
aluminum (Al) of the aluminoxane (A) and the transition metal (M) of the organometallic
compound (C) [(Al)/(M)] is equal or below 600, preferably in the range of 100 to equal
or below 600.
10. Solid catalyst system (CS) according to claim 8 or 9, wherein
(a) the organo-silicon compound (OS) is selected from the group consisting of octamethyltrisiloxane,
decamethyltetrasiloxane, octamethylcyclotetrasiloxane, methoxytrimethylsilane and
tetraethoxysilane. and/or
(b) the aromatic compound (AC) is toluene;
and/or
(c) the saturated aliphatic compound is selected from the group consisting of n-pentane,
n-hexane, n-heptane, n-octane, and mixtures thereof.
11. Solid catalyst system (CS) according to any one of the preceding claims 8 to 10, wherein
the organometallic compound (C) is formula (II)
(L)
2RMX
2 (II)
wherein
"M" is zirconium (Zr) or hafnium (Hf),
each "X" is independently selected from halogen, C1 to C6 alkyl, C5 to C6 cycloalkyl, C1 to C6 alkoxy, phenyl and benzyl groups,
each "L" is independently a cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl,
which can be independently substituted or unsubstituted, preferably at least one organic
ligand (L), preferably both organic ligands (L), comprise one or more substituents
independently selected from C1 to C20 hydrocarbyl or silyl groups, which optionally contain one or more heteroatoms selected
from groups 14 to 16 and/or are optionally substituted by halogen atom(s),
"R" is a divalent bridge selected from -R'2C-, -R'2Si-, wherein each R' is independently a hydrogen atom, C1 to C20 alkyl, C2 to C10 cycloalkyl.
12. Use of a solid catalyst system (CS) as defined in any one of the claims 8 to 11 or
a solid catalyst system (CS) obtained according to any one of the claims 1 to 7 for
the preparation of a polymer, like a polypropylene or polyethylene or any copolymers
thereof.
13. Process for the preparation of a polymer, like a polypropylene or polyethylene, by
polymerising monomer units in the presence of a solid catalyst system (CS) as defined
in any one of the claims 8 to 11.
14. Process according to claim 13, comprising the steps of
(A) preparing a solid catalyst system (CS) according to the claims 1 to 7,
(B) using said solid catalyst system (CS) in a polymerisation process thereby obtaining
the polymer, like the polypropylene or polyethylene.
1. Verfahren zur Herstellung eines festen Katalysator-Systems (CS), umfassend die Schritte
von
(i) Herstellen eines flüssigen Clathrats (LC), umfassend eine Mischung von einem Aluminoxan
(A), einer aromatischen Verbindung (AC) und einer Organo-Silizium-Verbindung (OS),
wobei das Mol-Verhältnis zwischen der Organo-Silizium-Verbindung (OS) und Aluminium
(Al) des Aluminoxans (A) [(OS)/(A1)] gleich oder unter 0,1 ist,
(ii) Vermischen des flüssigen Clathrats (LC) mit einer organo-metallischen Verbindung
(C) unter Gewinnen eines Flüssigkeits-Gemisches (MI), wobei das Flüssigkeits-Gemisch
(MI) homogen ist,
(iii) Ausfällen des festen Katalysator-Systems (CS) aus dem Flüssigkeits-Gemisch (MI)
durch Zusetzen einer gesättigten aliphatischen Verbindung zu dem Flüssigkeits-Gemisch
(MI),
(iv) gegebenenfalls Gewinnen der Teilchen des festen Katalysator-Systems (CS),
wobei während des Verfahrens kein Träger-Material zugesetzt wird.
2. Verfahren nach Anspruch 1, wobei die organo-metallische Verbindung (C) die Formel
(I) aufweist
(L)
mR
nMX
q (I)
wobei
"M" ein Übergangs-Metall (M) der Gruppe 3 bis 10 des Perioden-Systems (IUPAC 2007)
ist,
jedes "X" unabhängig ein mono-anionischer Ligand, wie ein σ-Ligand, ist,
jedes "L" unabhängig ein organischer Ligand ist, der an das Übergangs-Metall "M" koordiniert,
"R" eine Brücken-Gruppe ist, die die organischen Liganden (L) verbindet,
"m" 1, 2 oder 3, vorzugsweise 2, ist,
"n" 0, 1 oder 2, vorzugsweise 1, ist,
"q" 1, 2 oder 3, vorzugsweise 2, ist,
m+q gleich der Wertigkeit des Übergangs-Metalls (M) ist.
3. Verfahren nach Anspruch 1 oder 2, wobei das Mol-Verhältnis zwischen dem Aluminium
(Al) des Aluminoxans (A) und dem Übergangs-Metall (M) der organo-metallischen Verbindung
(C) [(Al)/(M)] in dem Bereich von 50 bis 600 liegt.
4. Verfahren nach einem der vorangehenden Ansprüche, wobei die Organo-Silizium-Verbindung
(OS) ausgewählt ist aus der Gruppe, bestehend aus Octamethyltrisiloxan, Decamethyltetrasiloxan,
Octamethylcyclotetrasiloxan, Methoxytrimethylsilan, Tetraethoxysilan und 1,1,1,3,5,5,5-Heptamethyl-3-phenyltrisiloxan.
5. Verfahren nach einem der vorangehenden Ansprüche, wobei
(a) die aromatische Verbindung (AC) Toluol ist; und/oder
(b) die gesättigte aliphatische Verbindung ausgewählt ist aus der Gruppe, bestehend
aus n-Pentan, n-Hexan, n-Heptan, n-Octan und Gemischen davon.
6. Verfahren nach einem der vorangehenden Ansprüche, wobei
(a) Schritt (i), d.h. das Vermischen von Aluminoxan (A), einer aromatischen Verbindung
(AC) und einer Organo-Silizium-Verbindung (OS), bei einer Temperatur in dem Bereich
von -20 bis 70°C, vorzugsweise in dem Bereich von 10 bis 40°C ausgeführt wird,
(b) Schritt (ii), d.h. das Vermischen des flüssigen Clathrats (LC) mit einer organo-metallischen
Verbindung (C) bei einer Temperatur in dem Bereich von 0 bis 50°C, vorzugsweise in
dem Bereich von 20 bis 30°C, ausgeführt wird.
7. Verfahren nach einem der vorangehenden Ansprüche, wobei die organo-metallische Verbindung
(C) die Formel (II) aufweist
(L)
2RMX
2 (II)
wobei
"M" Zirkonium (Zr) oder Hafnium (Hf) ist,
jedes "X" unabhängig ausgewählt ist aus Halogen, C1 bis C6 Alkyl-, C5 bis C6 Cycloalkyl-, C1 bis C6 Alkoxy-, Phenyl- und Benzyl-Gruppen,
jedes "L" unabhängig ein Cyclopentadienyl, Indenyl, Tetrahydroindenyl, Fluorenyl ist,
welches unabhängig substituiert oder unsubstituiert sein kann, vorzugsweise mindestens
ein organischer Ligand (L), vorzugsweise beide organische Liganden (L), einen oder
mehrere Substituenten umfassen, unabhängig ausgewählt aus C1 bis C20 Kohlenwasserstoff- oder Silyl-Gruppen,
welche gegebenenfalls ein oder mehrere Heteroatome enthalten, ausgewählt aus Gruppen
14 bis 16 und/oder gegebenenfalls mit Halogen-Atom(en) substituiert ist / sind, "R"
eine zweiwertige Brücke ist, ausgewählt aus -R'2C-, -R'2Si-, wobei jedes R' unabhängig ein Wasserstoff-Atom, C1 bis C20 Alkyl, C2 bis C10 Cycloalkyl ist.
8. Festes Katalysator-System (CS), umfassend das ReaktionsProdukt von
(a) einem flüssigen Clathrat (LC), erhalten durch Vermischen eines Aluminoxans (A),
einer aromatischen Verbindung (AC) und einer Organo-Silizium-Verbindung (OS), wobei
das Mol-Verhältnis zwischen der Organo-Silizium-Verbindung (OS) und Aluminium (Al)
des Aluminoxans (A) [(OS)/(Al)] unter 0,08 ist, und
(b) einer organo-metallischen Verbindung (C), wobei die organo-metallische Verbindung
(C) die Formel (I) aufweist
(L)mRnMXq (I)
wobei
"M" ein Übergangs-Metall (M) der Gruppe 3 bis 10 des Perioden-Systems (IUPAC 2007)
ist,
jedes "X" unabhängig ein σ-Ligand ist,
jedes "L" unabhängig ein organischer Ligand ist, der an das Übergangs-Metall (M) koordiniert,
"R" eine Brücken-Gruppe ist, die die organischen Liganden (L) verbindet,
"m" 1, 2 oder 3, vorzugsweise 2, ist,
"n" 0, 1 oder 2, vorzugsweise 1, ist,
"q" 1, 2 oder 3, vorzugsweise 2, ist,
m+q gleich der Wertigkeit des Übergangs-Metalls (M) ist,
wobei das feste Katalysator-System (CS) durch Vermischen des flüssigen Clathrats (LC)
mit der organo-metallischen Verbindung (C) unter Gewinnen eines Flüssigkeits-Gemisches
(MI) erhalten wird, wobei weiterhin das feste Katalysator-System (CS) aus dem Gemisch
(MI) durch Zusetzen einer gesättigten aliphatischen Verbindung zu dem Gemisch (MI)
ausgefällt wird, und wobei das Gemisch (MI) homogen ist und das feste Katalysator-System
(CS) ungetragen ist, d.h. während des Verfahrens kein Träger-Material zugesetzt wird.
9. Festes Katalysator-System (CS) nach Anspruch 8, wobei das Mol-Verhältnis zwischen
dem Aluminium (Al) des Aluminoxans (A) und dem Übergangs-Metall (M) der organo-metallischen
Verbindung (C) [(Al)/(M)] gleich oder unter 600, vorzugsweise in dem Bereich von 100
bis gleich oder unter 600, liegt.
10. Festes Katalysator-System (CS) nach Anspruch 8 oder 9, wobei
(a) die Organo-Silizium-Verbindung (OS) ausgewählt ist aus der Gruppe, bestehend aus
Octamethyltrisiloxan, Decamethyltetrasiloxan, Octamethylcyclotetrasiloxan, Methoxytrimethylsilan
und Tetraethoxysilan
und/oder
(b) die aromatische Verbindung (AC) Toluol ist;
und/oder
(c) die gesättigte aliphatische Verbindung ausgewählt ist aus der Gruppe, bestehend
aus n-Pentan, n-Hexan, n-Heptan, n-Octan und Gemischen davon.
11. Festes Katalysator-System (CS) nach einem der vorangehenden Ansprüche 8 bis 10, wobei
die organo-metallische Verbindung (C) die Formel (II) aufweist
(L)
2RMX
2 (II)
wobei
"M" Zirkonium (Zr) oder Hafnium (Hf) ist,
jedes "X" unabhängig ausgewählt ist aus Halogen, C1 bis C6 Alkyl-, C5 bis C6 Cycloalkyl-, C1 bis C6 Alkoxy-, Phenyl- und Benzyl-Gruppen,
jedes "L" unabhängig ein Cyclopentadienyl, Indenyl, Tetrahydroindenyl, Fluorenyl ist,
welches unabhängig substituiert oder unsubstituiert sein kann, vorzugsweise mindestens
ein organischer Ligand (L), vorzugsweise beide organische Liganden (L), einen oder
mehrere Substituenten umfassen, unabhängig ausgewählt aus C1 bis C20 Kohlenwasserstoff- oder Silyl-Gruppen, welche gegebenenfalls ein oder mehrere Heteroatome
enthalten, ausgewählt aus Gruppen 14 bis 16 und/oder gegebenenfalls mit Halogen-Atom
(en) substituiert sind,
"R" eine zweiwertige Brücke ist, ausgewählt aus -R'2C-, -R'2Si-, wobei jedes R' unabhängig ein Wasserstoff-Atom, C1 bis C20 Alkyl, C2 bis C20 Cycloalkyl ist.
12. Verwendung eines festen Katalysator-Systems (CS), wie in einem der Ansprüche 8 bis
11 definiert, oder eines festen Katalysator-Systems (CS), erhalten nach einem der
Ansprüche 1 bis 7, zur Herstellung eines Polymers, wie ein Polypropylen oder Polyethylen
oder beliebige Copolymere davon.
13. Verfahren zur Herstellung eines Polymers, wie ein Polypropylen oder Polyethylen, durch
Polymerisieren von Monomer-Einheiten in Gegenwart eines festen Katalysator-Systems
(CS), wie in einem der Ansprüche 8 bis 11 definiert.
14. Verfahren nach Anspruch 13, umfassend die Schritte von
(A) Herstellen eines festen Katalysator-Systems (CS) nach den Ansprüchen 1 bis 7,
(B) Verwendung des festen Katalysator-Systems (CS) in einem Polymerisations-Verfahren,
wodurch das Polymer, wie das Polypropylen oder Polyethylen, erhalten wird.
1. Procédé pour la préparation d'un système de catalyseur solide (CS) comprenant les
étapes consistant à
(i) préparer un clathrate liquide (LC) comprenant un mélange d'un aluminoxane (A),
d'un composé aromatique (AC) et d'un composé organique du silicium (OS), dans lequel
le rapport molaire entre le composé organique du silicium (OS) et l'aluminium (Al)
de l'aluminoxane (A) [(OS)/(Al)] est égal ou inférieur à 0,1,
(ii) mélanger ledit clathrate liquide (LC) avec un composé organométallique (C), ce
qui donne un mélange liquide (MI), lequel mélange liquide (MI) est homogène,
(iii) précipiter le système de catalyseur solide (CS) hors dudit mélange liquide (MI)
par addition d'un composé aliphatique saturé audit mélange liquide (MI),
(iv) éventuellement récupérer des particules du système de catalyseur solide (CS),
dans lequel, durant le procédé, aucun matériau de support n'est ajouté.
2. Procédé selon la revendication 1, dans lequel ledit composé organométallique (C) répond
à la formule (I)
(L)
mR
nMX
q (I)
dans laquelle
"M" est un métal de transition (M) des Groupes 3 à 10 du Tableau Périodique (IUPAC
2007),
chaque "X" est indépendamment un ligand monoanionique, tel qu'un ligand σ,
chaque "L" est indépendamment un ligand organique qui se coordonne au métal de transition
"M",
"R" est un groupe pontant liant lesdits ligands organiques (L),
"m" vaut 1, 2 ou 3, de préférence 2,
"n" vaut 0, 1 ou 2, de préférence 1,
"q" vaut 1, 2 ou 3, de préférence 2,
la somme m+q est égale à la valence du métal de transition (M).
3. Procédé selon la revendication 1 ou 2, dans lequel le rapport molaire entre l'aluminium
(Al) de l'aluminoxane (A) et le métal de transition (M) du composé organométallique
(C) [(Al/(M)] est situé dans la plage allant de 50 à 600.
4. Procédé selon l'une quelconque des revendications précédentes, dans lequel le composé
organique du silicium (OS) est choisi dans l'ensemble constitué par l'octaméthyltrisiloxane,
le décaméthyltétrasiloxane, l'octaméthylcyclotétrasiloxane, le méthoxytriméthylsilane,
le tétraéthoxysilane et le 1,1,1,3,5,5,5-heptaméthyl-3-phényltrisiloxane.
5. Procédé selon l'une quelconque des revendications précédentes, dans lequel
(a) le composé aromatique (AC) est le toluène ;
et/ou
(b) le composé aliphatique saturé est choisi dans l'ensemble constitué par le n-pentane,
le n-hexane, le n-heptane, le n-octane, et leurs mélanges.
6. Procédé selon l'une quelconque des revendications précédentes, dans lequel
(a) l'étape (i), c'est-à-dire le mélange d'aluminoxane (A), d'un composé aromatique
(AC) et d'un composé organique du silicium (OS), est effectuée à une température située
dans la plage allant de -20 à 70°C, de préférence dans la plage allant de 10 à 40°C
;
(b) l'étape (ii), c'est-à-dire le mélange du clathrate liquide (LC) avec un composé
organométallique (C), est effectuée à une température située dans la plage allant
de 0 à 50°C, de préférence dans la plage allant de 20 à 30°C.
7. Procédé selon l'une quelconque des revendications précédentes, dans lequel le composé
organométallique (C) répond à la formule (II)
(L)
2RMX
2 (II)
dans laquelle
"M" est le zirconium (Zr) ou le hafnium (Hf),
chaque "X" est indépendamment choisi parmi les halogènes et les groupes alkyle en
C1 à C6, cycloalkyle en C5 à C6, alcoxy en C1 à C6, phényle et benzyle,
chaque "L" est indépendamment un cyclopentadiényle, indényle, tétrahydroindényle,
fluorényle, qui peut être indépendamment substitué ou non substitué, de préférence
au moins un ligand organique (L), de préférence les deux ligands organiques (L), comprennent
un ou plusieurs substituant(s) indépendamment choisi(s) parmi les groupes silyle et
hydrocarbyle en C1 à C20, contenant éventuellement un ou plusieurs hétéroatome(s) choisi(s) parmi les Groupes
14 à 16, et/ou sont éventuellement substitués par un ou plusieurs atome(s) d'halogène,
"R" est un pont divalent choisi parmi -R'2C-, -R'2-Si-, où chaque R' est indépendamment un atome d'hydrogène, un alkyle en C1 à C20, un cycloalkyle en C2 à C10.
8. Système de catalyseur solide (CS) comprenant le produit de la réaction de
(a) un clathrate liquide (LC) obtenu par mélange d'un aluminoxane (A), d'un composé
aromatique (AC) et d'un composé organique du silicium (OS), dans lequel le rapport
molaire entre le composé organique du silicium (OS) et l'aluminium (Al) de l'aluminoxane
(A) [(OS)/(Al)] est inférieur à 0,08, et
(b) un composé organométallique (C), lequel composé organométallique (C) répond à
la formule (I)
(L)mRnMXq (I)
dans laquelle
"M" est un métal de transition (M) des Groupes 3 à 10 du Tableau Périodique (IUPAC
2007),
chaque "X" est indépendamment un ligand σ,
chaque "L" est indépendamment un ligand organique qui se coordonne au métal de transition
"M",
"R" est un groupe pontant liant lesdits ligands organiques (L),
"m" vaut 1, 2 ou 3, de préférence 2,
"n" vaut 0, 1 ou 2, de préférence 1,
"q" vaut 1, 2 ou 3, de préférence 2,
la somme m+q est égale à la valence du métal de transition (M),
lequel système de catalyseur solide (CS) est obtenu par mélange dudit clathrate liquide
(LC) avec le composé organométallique (C), ce qui donne un mélange liquide (MI), et
lequel système de catalyseur solide (CS) est en outre précipité à partir dudit mélange
(MI) par addition d'un composé aliphatique saturé audit mélange (MI),
dans lequel le mélange (MI) est homogène et le système de catalyseur solide (CS) est
non supporté, c'est-à-dire que, durant le procédé, aucun matériau de support n'est
ajouté.
9. Système de catalyseur solide (CS) selon la revendication 8, dans lequel le rapport
molaire entre l'aluminium (Al) de l'aluminoxane (A) et le métal de transition (M)
du composé organométallique (C) [(Al/(M)] est égal ou inférieur à 600, de préférence
situé dans la plage allant de 100 à 600 ou moins.
10. Système de catalyseur solide (CS) selon la revendication 8 ou 9, dans lequel
(a) le composé organique du silicium (OS) est choisi dans l'ensemble constitué par
l'octaméthyltrisiloxane, le décaméthyltétrasiloxane, l'octaméthylcyclotétrasiloxane,
le méthoxytriméthylsilane et le tétraéthoxysilane,
et/ou
(b) le composé aromatique (AC) est le toluène ;
et/ou
(c) le composé aliphatique saturé est choisi dans l'ensemble constitué par le n-pentane,
le n-hexane, le n-heptane, le n-octane, et leurs mélanges.
11. Système de catalyseur solide (CS) selon l'une quelconque des revendications 8 à 10,
dans lequel le composé organométallique (C) répond à la formule (II)
(L)
2RMX
2 (II)
dans laquelle
"M" est le zirconium (Zr) ou le hafnium (Hf),
chaque "X" est indépendamment choisi parmi les halogènes et les groupes alkyle en
C1 à C6, cycloalkyle en C5 à C6, alcoxy en C1 à C6, phényle et benzyle,
chaque "L" est indépendamment un cyclopentadiényle, indényle, tétrahydroindényle,
fluorényle, qui peut être indépendamment substitué ou non substitué, de préférence
au moins un ligand organique (L), de préférence les deux ligands organiques (L), comprennent
un ou plusieurs substituant(s) indépendamment choisi(s) parmi les groupes silyle et
hydrocarbyle en C1 à C20, contenant éventuellement un ou plusieurs hétéroatome(s) choisi(s) parmi les Groupes
14 à 16, et/ou sont éventuellement substitués par un ou plusieurs atome(s) d'halogène,
"R" est un pont divalent choisi parmi -R'2C-, -R'2-Si-, où chaque R' est indépendamment un atome d'hydrogène, un alkyle en C1 à C20, un cycloalkyle en C2 à C10.
12. Utilisation d'un système de catalyseur solide (CS) tel que défini dans l'une quelconque
des revendications 8 à 11 ou d'un système de catalyseur solide (CS) obtenu conformément
à l'une quelconque des revendications 1 à 7 pour la préparation d'un polymère, tel
qu'un polypropylène ou polyéthylène ou n'importe quels copolymères de ceux-ci.
13. Procédé pour la préparation d'un polymère, tel qu'un polypropylène ou polyéthylène,
par polymérisation de motifs monomères en présence d'un système de catalyseur solide
(CS) tel que défini dans l'une quelconque des revendications 8 à 11.
14. Procédé selon la revendication 13, comprenant les étapes consistant à
(A) préparer un système de catalyseur solide (CS) selon les revendications 1 à 7,
(B) utiliser ledit système de catalyseur solide (CS) dans un procédé de polymérisation,
ce qui donne ainsi le polymère, tel que le polypropylène ou polyéthylène.