Supported cobalt catalyst, production thereof and use thereof for the polymerization of unsaturated compounds

The present invention relates to a supported cobalt catalyst consisting of PA1 (a) cobalt compounds, PA1 (b) organoaluminium compounds, PA1 (c) water or OH-acidic compounds, PA1 (d) inorganic or polymeric organic support materials and PA1 (e) modifiers selected from the group comprising tertiary phosphines, to the production thereof and to the use thereof for the polymerization of unsaturated compounds, in particular of conjugated dienes, in the gas phase. With the assistance of the catalysts according to the invention, it is possible to achieve gas phase polymerization of conjugated dienes with an elevated content of lateral double bonds in the polymers.

This invention relates to a novel supported cobalt catalyst, to the 
production thereof and to the use thereof for the polymerisation of 
unsaturated compounds, in particular of conjugated dienes, in the gas 
phase. 
The polymerisation of unsaturated compounds, for example conjugated dienes, 
in solution has the disadvantages that, during separation of the unreacted 
monomers and solvent from the resultant polymer, low molecular weight 
compounds may pass into the environment via the waste air and waste water 
and must consequently be disposed of. Moreover, large quantities of 
solvents must also be used and then separated from the resultant polymers, 
with considerable energy input, which reduces the economic viability of 
the polymerisation process. The solvents are furthermore generally 
combustible and highly flammable and thus constitute an additional 
potential hazard during polymerisation. 
In recent years, the gas phase process has proved particularly advantageous 
in particular for the production of polyethylene and polypropylene, and 
has become increasingly widely used industrially. The advantages of the 
gas phase process are in particular based on the fact that no solvents are 
used and emissions and waste water contamination may be reduced. 
Due to the advantages of the gas phase process, efforts have been made in 
recent years to use gas phase polymerisation processes with conjugated 
dienes too. Thus, for example, novel catalyst systems have been developed 
for the polymerisation of conjugated dienes, in particular butadiene, 
which have proved suitable in gas phase polymerisation (c.f. for example 
DE-A 43 34 045, EP 727 447, WO 96/31543, WO 96/31544, WO 96/04323, WO 
96/04322 and WO 97/08211). 
When used for the polymerisation of conjugated dienes in the gas phase, the 
catalysts described in the above-stated patent publications give rise to 
an elevated content of 1,4-cis double bonds in the polymers. According to 
the patent literature, the cobalt catalysts, but also to a less 
significant extent the nickel and titanium catalysts, used in gas phase 
polymerisation, unlike the rare earth metals, are used together with a 
solvent, wherein either the entire catalyst or only the co-catalyst is 
added in dissolved form in a solvent. As a result, in the case of 
continuous operation, solvent may accumulate undesirably in the 
circulating gas. The solvent must then be removed from the circulating gas 
so that it does not accumulate. Furthermore, the cobalt catalysts are not 
present in the catalyst system at a defined ratio, such that apportionment 
of the co-catalyst into the reaction chamber does not result in optimum 
utilisation of the co-catalyst, which is economically disadvantageous. The 
solvent must moreover be removed from the polymer, so complicating the 
process. 
The aim of the present invention is to provide novel supported cobalt 
catalysts for the gas phase polymerisation of conjugated dienes which, in 
addition to cis polymerisation of conjugated dienes, also allow the 
production of polymers in the gas phase having an elevated and freely 
adjustable content of 1,2 units and which catalysts may be used without 
the addition of solvents. 
This aim is achieved by using supported catalysts containing cobalt 
compounds of specific modifiers for polymerisation of conjugated dienes. 
The present invention accordingly provides supported cobalt catalysts 
consisting of 
(a) cobalt compounds, 
(b) organoaluminium compounds, 
(c) water or OH-acidic compounds, 
(d) inorganic or polymeric organic support materials and 
(e) modifiers selected from the group comprising tertiary phosphines, 
wherein the molar ratio of components (a):(b):(e) is within the range from 
1:10 to 1000:0.1 to 100, the molar ratio of components (b):(c) is within 
the range from 1:0.1 to 0.9 and 0.01 to 100 mmol of component (a) are used 
per 100 g of component (d). 
The molar ratio of components (a):(b):(e) is preferably 1:10 to 500:0.5 to 
50, the molar ratio of component (b):(c) is 1:0.2 to 0.8 and 0.1 to 50 
mmol of component (a) are used per 100 g of component (d). 
Cobalt compounds (component (a)) which may be considered are in particular 
those selected from the group consisting of 
I .beta.-diketonates of cobalt, 
II .beta.-keto acid complexes of cobalt, 
III cobalt salts of organic acids having 6 to 15 carbon atoms, 
IV complexes of halogenated cobalt compounds of the formula CoX.sub.a 
D.sub.b, wherein X denotes a halogen atom, a means the numbers 2 or 3, D 
is an organic compound selected from the group consisting of tertiary 
amines, alcohols, tertiary phosphines, ketones and N,N-dialkylamides and b 
means a number from 0 to 6, together with 
V organometallic complexes of cobalt with .pi.-bonded anions. 
Component (b) organoaluminium compounds which may in particular be 
considered are organoaluminium compounds of the formula X.sub.c AlR.sub.d, 
wherein X denotes a halogen, R denotes an organic alkyl group having 1 to 
12 carbon atoms, c and d mean the numbers 1 to 2, wherein the sum of c and 
d is the number 3. 
Cobalt compounds (component (a)) which are soluble in inert organic 
solvents and may be used are, for example: 
(I) .beta.-diketonates of cobalt with .beta.-diketonates of the formula 
R.sup.1 --CO--CR.sup.2 --CO--R.sup.3, wherein R.sup.1 to R.sup.3 may be 
identical or different and denote hydrogen or an alkyl group having 1 to 
10 C atoms, for example Co(Me--CO--CH--CO--Me).sub.2 and 
Co(Me--CO--CH--CO--Me).sub.3 ; 
(II) .beta.-keto acid complexes of cobalt with keto acid esters of the 
formula R.sup.1 --CO--CR.sup.2 --CO--O--R.sup.3, wherein R.sup.1 to 
R.sup.3 may be identical or different and denote hydrogen or an alkyl 
group having 1 to 10 C atoms, for example Co(Me--CO--CH--CO--O--Me).sub.2, 
Co(Me--CO--CH--CO--O--Et).sub.2, Co(Me--CO--CH--CO--O--Me).sub.3 and 
Co(Me--CO--CH--CO--O--Et).sub.3 ; 
(III) cobalt salts of organic acids having 6 to 15 carbon atoms, for 
example Co(octanoate).sub.2, Co(versatate).sub.2 ; 
(IV) complexes of halogenated cobalt compounds of the formula CoX.sub.e 
D.sub.f, wherein X denotes a halogen atom, e means the numbers 2 or 3, D 
is an organic compound selected from the group consisting of tertiary 
amines, alcohols, tertiary phosphines, ketones and N,N-dialkylamides and f 
means a number from 0 to 6, for example CoCl.sub.2 -(pyridine).sub.2, 
CoBr.sub.2 -(pyridine).sub.2, CoCl.sub.2 --(PPh.sub.3).sub.2, CoBr.sub.2 
--(PPh.sub.3).sub.2, CoCl.sub.2 -(vinylimidazole).sub.4, CoCl.sub.2 
--(EtOH); 
(V) organometallic complexes having .pi.-bonded anions, for example 
tris-(.pi.-allyl)cobalt, bis-(.pi.-allyl)cobalt chloride, 
bis-(.pi.-allyl)cobalt bromide, bis-(.pi.-allyl)cobalt iodide, 
biscrylonitrile-(.pi.-allyl)cobalt, 
(1,3-butadiene)[1-(2-methyl-3-butenyl)-.pi.-allyl]cobalt, 
bis-(.pi.-1,5-cyclooctadienyl)-tert.-butyl-isonitrile)cobalt, 
(.pi.-cyclooctenyl)-(.pi.-1,5-cyclooctadienyl)cobalt, 
(.pi.-cycloheptadienyl)-(.pi.-1,5-cyclooctadienyl)cobalt, 
(bicyclo[3.3.0]-octadienyl)-(.pi.-1,5-cyclooctadienyl)cobalt. 
Component (b) organoaluminium compounds which may in particular be used are 
: 
diethylaluminium chloride, ethylaluminium sesquichloride, ethylaluminium 
dibromide, diethylaluminium bromide, ethylaluminium diiodide, 
diethylaluminium iodide, diisobutylaluminium chloride, octylaluminium 
dichloride, dioctylaluminium chloride. 
In addition to water, other OH-acidic compounds, such as for example 
alcohols and oxide support materials having OH groups on the surface of 
the support, are suitable as component (c). Support materials based on 
silicon dioxide and aluminium oxide may be mentioned by way of example. 
Support materials (component (d)) which are used are particulate, inorganic 
solids or particulate, polymeric organic solids having a specific surface 
area of &gt;10, preferably of 10 to 1000 m.sup.2 /g (BET) and a pore volume 
of 0.3 to 15, preferably of 0.5 to 12 ml/g, which are inert during the 
polymerisation reaction. 
The specific surface area (BET) is determined in the conventional manner 
[c.f. for example S. Brunauer, P. H. Emmett and Teller, J. Amer. Chem. 
Soc. 60 (2) (1938) 309], while pore volume is determined by the 
centrifugation method [M. McDaniel, J. Colloid Interface Sci. 78 (1990) 
31]. 
Suitable inorganic solids are in particular silica gels, clays, 
aluminosilicates, talcum, zeolites, carbon black, graphite, activated 
carbon, inorganic oxides, such as for example silicon dioxide, aluminium 
oxide, magnesium oxide and titanium dioxide, inorganic salts, such as for 
example aluminium fluoride, as well as silicon carbide, preferably silica 
gels, zeolites, magnesium chloride and carbon black. Organic support 
materials are also suitable, such as for example polyethylene, 
polypropylene, polystyrene or polybutadiene. 
The stated inorganic solids, which comply with the above-stated 
specification and are accordingly suitable for use are described in 
greater detail in, for example, Ullmanns Enzyklopadie der technischen 
Chemie, volume 21, pp. 439 et seq. (silica gels), volume 23, pp. 311 et 
seq. (clays), volume 14, pp. 633 et seq. (carbon blacks), volume 24, pp. 
575 et seq. and volume 17, pp. 9 et seq. (zeolites). 
The inorganic and organic polymeric solids may be used individually or 
mixed together. As already mentioned, 0.01 to 100 mmol of component (a), 
preferably 0.1 to 50 mmol of component (a) are used per 100 g of support 
material. 
It is, of course, also possible to heterogenise the catalyst onto 
non-porous, particulate solids, such as glass beads or glass rings, or 
onto the surface of the reaction vessels, such as for example glass 
bottles or flasks. 
Modifiers (component (e)) which may in particular be considered are those 
tertiary phosphines of the formula P(3-R.sup.1 -,4-R.sup.2 -,5-R.sup.3 
--C.sub.6 H.sub.2).sub.3, in which R.sup.1 to R.sup.3 are identical or 
different and denote hydrogen or an alkyl group having 1 to 6 C atoms, for 
example P(C.sub.6 H.sub.5).sub.3,P(4-Me--C.sub.6 
H.sub.4).sub.3,P(3,5-Me.sub.2 --C.sub.6 H.sub.3).sub.3. The figures 3, 4 
and 5 in the general formula for the phosphines denote the substitution 
position of the aromatic residue. 
It should be noted in this connection that the component (a) cobalt 
compounds and the component (b) organoaluminium compounds may be used both 
individually and mixed with each other. The most favourable mixture ratio 
may readily be determined by appropriate preliminary testing. 
The present invention also provides a process for the production of the 
supported cobalt catalysts consisting of 
(a) cobalt compounds, 
(b) organoaluminium compounds, 
(c) water or OH-acidic compounds, 
(d) inorganic or polymeric organic support materials, 
(e) modifiers selected from the group comprising tertiary phosphines, 
which process is characterised in that components (a) to (e) are reacted 
together in an inert solvent and/or diluent at temperatures of -80 to 
100.degree. C. in a molar ratio of components (a):(b):(e) within the range 
from 1:10 to 1000:0.1 to 100 a molar ratio of components (b):(c) within 
the range from 1:0.1 to 0.9 and a ratio of 0.01 to 100 mmol of component 
(a) per 100 g of component (d) and the inert solvent and/or diluent is 
subsequently removed at temperatures of -40 to 100.degree. C., optionally 
under reduced pressure. 
Components (a) to (e) are in particular reacted in the above-stated 
preferred quantity ratio. 
The individual components may be combined in any desired order in the 
process according to the invention. 
The components are preferably blended at temperatures of -50 to 80.degree. 
C., in particular at -40 to 60.degree. C. The temperature range is here 
between the melting and boiling point of the inert solvent and/or diluent 
used. 
Aliphatic and/or aromatic solvents such as butane, pentane, n-hexane, 
cyclohexane, benzene, toluene, xylene may in particular be considered as 
the inert solvent and/or diluent (S/D). 
The inert solvents and/or diluents are conventionally used in quantities of 
1 to 1000 g, relative to 100 g of support material. The quantity of inert 
solvents and/or diluents is kept as small as possible on grounds of 
economy. 
The catalysts according to the invention may be produced in various 
different ways: 
The support material may, for example, be suspended in the inert solvent 
and/or diluent and the components (a), (b), (c) and (e) then added in any 
desired order. It is also possible to produce a solution of the catalyst 
components (a), (b), (c) and (e) by adding the components in any desired 
order to an inert solvent and adding this solution to the support 
material, which is either suspended in an inert solvent and/or diluent or 
is in dry form. 
The catalyst may also be produced in the presence of a diene, wherein the 
diene may be identical to or different from the diene which is 
subsequently polymerised by gas phase polymerisation using this catalyst. 
The following order of addition of the components has proved to be a 
particularly suitable embodiment: 
The support material is suspended in the solvent and/or diluent and the 
components are added in the order (b)-(c)-(a)-(e), wherein the components 
are added either dissolved in a suitable solvent or without additional 
solvent. 
Another suitable embodiment comprises the following addition of the 
components: 
The support material is suspended in the solvent and/or diluent and the 
components are added in the order (a)-(c)-(b)-(e), wherein the components 
are added either dissolved in a suitable solvent or without additional 
solvent. 
As mentioned, the solvents and/or diluents used may be used individually or 
mixed together, this statement applying to all the components of the 
catalyst according to the invention. Once the reaction is complete, the 
solvent and/or diluent is removed by distillation, optionally under a 
vacuum, wherein the catalyst support is obtained as a free-flowing solid. 
The present invention also provides the use of the supported cobalt 
catalysts according to the invention for the polymerisation of unsaturated 
compounds, in particular for the gas phase polymerisation of conjugated 
dienes, preferably of 1,3-butadiene, isoprene, pentadiene and/or 
dimethylbutadiene. It is also possible to use the catalyst according to 
the invention for polymerisation in solution or using the slurry process. 
Polymerisation is performed using the gas phase process, for example in 
such a manner that the unsaturated compound is brought into contact with 
the catalyst according to the invention. The gaseous monomers may here be 
mixed with further gases for the purposes of dilution or dissipation of 
heat or to control molecular weight or microstructure. 
Polymerisation may be performed at pressures of 1 mbar to 50 bar, 
preferably of 1 to 20 bar. Polymerisation is generally performed at 
temperatures of -40 to 150.degree. C., preferably at -20 to 100.degree. 
C., particularly preferably at 0 to 80.degree. C. 
Gas phase polymerisation may be performed in any apparatus suitable for gas 
phase polymerisation. 
It is thus possible, for example, to use a rotary reactor or a fluidised 
bed reactor or a combination of these reactor types. Gas phase 
polymerisation may also be performed with the addition of inert dusting 
agents, such as silica gel or carbon black. 
In gas phase polymerisation, the catalyst according to the invention is 
transferred into an apparatus which is capable of maintaining the 
pulverulent catalyst in motion. This may be achieved, for example, by 
stirring, rotation and/or by a stream of gas. The inert gas, for example 
argon, initially present in the gas space is then replaced by the gaseous 
monomers. Polymerisation then begins immediately and the temperature 
rises. The monomer, optionally diluted with an inert gas, is added to the 
reactor at a rate such that the desired reaction temperature is not 
exceeded. The reaction temperature may also be established in the 
conventional manner by heating or cooling. Heat may also be dissipated by 
introducing liquid substances which vaporise at the reaction temperature. 
Polymerisation is terminated by shutting off the monomer feed. The polymer 
may be further treated in such a manner that the catalyst is deactivated 
and the polymer is treated with conventional quantities of for example, 
known antioxidants, such as sterically hindered phenols or aromatic 
amines. 
The advantages achieved in the gas phase polymerisation of in particular 
conjugated dienes with the assistance of the cobalt catalyst according to 
the invention are in particular that it is possible with the assistance of 
the cobalt catalyst according to the invention to produce polymers having 
an elevated content of lateral double bonds, for example polybutadiene 
having an elevated content of 1,2 double bonds, wherein the content of 
1,2-polybutadiene may readily be controlled by appropriate variation of 
the catalyst. It is furthermore surprising that it is possible by using 
the catalyst according to the invention to operate without solvent. 
Solvents have in fact always been required when using prior art cobalt 
catalysts.

EXAMPLES 
In the stated Examples, the supported catalysts were prepared and the gas 
phase polymerisations performed in an atmosphere of purified argon. The 
microstructure of the polybutadienes was determined by IR spectroscopy [E. 
O. Schmalz, W. Kimmer, Z. anal Chem., 181 (1961) 229]. 
Example 1 
4.35 ml of a 1.15 molar solution of DEAC (=5 mmol diethylaluminium 
chloride) in n-hexane were added at -40.degree. C. to a solution of 45 ml 
of water (=2.5 mmol) in 5 ml of toluene under argon in a 1 liter glass 
flask, the solution was heated to 20.degree. C. within 30 minutes while 
being stirred with a magnetic stirrer and 0.25 ml of a 0.2 molar solution 
of Co(oct).sub.2 (=0.05 mmol of cobalt(II) octanoate) in toluene and 262 
mg of PPh.sub.3 (1 mmol) were then added. The solvent was then completely 
removed by vacuum distillation at room temperature and the resultant 
catalyst uniformly distributed over the entire wall of the glassware by 
tilting. 
Gas phase polymerisation was performed by completely evacuating the flask 
and then filling it with gaseous butadiene. The reaction temperature was 
maintained by a water bath adjusted to 40.degree. C. Butadiene pressure 
was maintained between 650 and 1050 mbar during polymerisation. The course 
of polymerisation was determined by means of the pressure profile over 
time. After 60 minutes, 8.9 g of polybutadiene were obtained. 93% of the 
polybutadiene could be dissolved in THF and determination of the 
microstructure revealed a content of 80% 1,2-, 18% 1,4-cis and 2% 
1,4-trans-polybutadiene. 
Examples 2 to 9 
The catalysts were prepared and the gas phase polymerisation performed in 
accordance with Example 1. Table 1 summarises the batch sizes used for 
catalyst production, polymerisation conditions and results of the gas 
phase polymerisation. 
TABLE 1 
__________________________________________________________________________ 
Co(oct).sub.2 
DEAC 
H.sub.2 O in 
PPh.sub.3 in 
COD in 
T in 
t in 
PB in 
1,2 in 
cis in 
trans 
No. in mmol in mmol mmol mmol mmol .degree. C. min g % % in % 
__________________________________________________________________________ 
2 0.05 5.0 2.5 0.51 
-- 0 100 
18.5 
87 11 2 
3 0.05 5.0 2.5 0.5 0.5 25 68 8.1 81 16 3 
4 0.05 5.0 2.5 0.5 0.25 25 69 10.1 82 15 3 
5 0.05 5.0 2.5 0.25 0.5 25 64 17.7 69 27 4 
6 0.42 5.0 1.0 0.42 -- 25 60 13.6 14 73 13 
7 0.42 5.0 1.0 -- -- 25 70 39.0 5 76 19 
8 0.05 5.0 2.5 -- -- 40 60 16.0 5 84 11 
9 0.05 5.0 2.5 -- -- 40 85 31.1 nd nd nd 
__________________________________________________________________________ 
nd = not determined 
Example 10 
1.9 g of a microporous polypropylene support (Accurel EP100, Akzo Nobel) 
were suspended in 24 ml of toluene with 0.4 mmol of water at 20.degree. C. 
in a 250 ml glass flask. 0.095 ml of a 1.78 molar solution of 
Co(oct).sub.2 in hexane (0.17 mmol), 1.74 ml of a 1.15 molar solution of 
DEAC in hexane (2.0 mmol) and 10.5 mg of PPh.sub.3 (0.04 mmol) were 
stirred in in succession. After 2 hours, the solvent was removed by vacuum 
distillation and the supported catalyst obtained as a free-flowing solid. 
Gas phase polymerisation was performed by transferring the supported 
catalyst into a 1 liter glass flask. The flask was completely evacuated 
and then filled with gaseous butadiene. The reaction temperature was 
maintained by a water bath adjusted to 50.degree. C. Butadiene pressure 
was maintained between 650 and 1050 mbar during polymerisation. The course 
of polymerisation was determined by means of the pressure profile over 
time. After 30 minutes, 1.0 g of polybutadiene was obtained having a 
content of 43% 1,2-, 41% 1,4-cis and 16% 1,4-trans-polybutadiene. 
Examples 11-15 
The catalysts were prepared and the gas phase polymerisation performed in 
accordance with Example 10, the catalysts being produced without addition 
of a modifier. Table 2 summarises the batch sizes and reaction conditions 
used for catalyst production, polymerisation conditions and results of the 
gas phase polymerisation. 
TABLE 2 
__________________________________________________________________________ 
Catalyst production Gas phase polymerisation 
Toluene 
H.sub.2 O in 
DEAC 
Co(oct).sub.2 
T in 
t in 
T in 
t in 
PB in 
1,2 
cis 
trans 
No. Support in ml mmol in mmol in mmol .degree. C. min .degree. C. min 
g in % in % in % 
__________________________________________________________________________ 
11 1.2 g 
24 0.4 2.0 0.17 20 20 40 60 6.5 
9 74 17 
PP.sup.a) 
12 3.2 g 35 1.5 3.8 0.32 -30 15 25 30 5.9 7 81 12 
PP.sup.a) 
13 5.8 g 10 1.0 5.0 0.42 -40 60 25 78 21.0 5 80 15 
MgCl.sub.2 
14 16.9 g 50 -- 92 0.92 25 40 25 50 11.0 nd nd nd 
SiO.sub.2.sup.b) 
15 9.7 g 45 -- 11.5 0.82 25 30 25 70 16.0 nd nd nd 
SiO.sub.2.sup.c) 
__________________________________________________________________________ 
.sup.a) PP = Accurel EP100; Akzo Nobel 
.sup.b) SiO.sub.2 = Sylopol 3325N; Grace; dried for 24 h at 250.degree. C 
.sup.c) SiO.sub.2 = Sylopol 3325N; Grace; dried for 24 h at 800.degree. C