U.S. patent application number 09/847932 was filed with the patent office on 2003-01-30 for catalyst for propylene polymerization.
Invention is credited to Epstein, Ronald A., Wallack, William T..
Application Number | 20030022786 09/847932 |
Document ID | / |
Family ID | 25301864 |
Filed Date | 2003-01-30 |
United States Patent
Application |
20030022786 |
Kind Code |
A1 |
Epstein, Ronald A. ; et
al. |
January 30, 2003 |
Catalyst for propylene polymerization
Abstract
A polypropylene catalyst (no more than 2 wt % titanium) contains
at least one titanium-halogen bond-containing compound, internal
donor, and activated, amorphous magnesium dihalide support,
essentially free of alkoxy functionality. It is made by combining
and heating titanium tetrachloride, magnesium halide precursor
compound, and internal electron donor, in alkylbenzene solvent, to
form an intermediate product; washing that product with an aromatic
hydrocarbon solvent at elevated temperature producing a washed
product; decantation of supernatant; treating the washed product
with titanium tetrachloride in an alkylbenzene solvent to form a
treated product and a supernatant; heating of that product and
supernatant; decantation of the supernatant; washing of the treated
product with an aromatic hydrocarbon solvent at elevated
temperature; decantation of the supernatant; washing of the treated
product with an aromatic hydrocarbon solvent; and addition of an
aliphatic hydrocarbon solvent to the treated product with
decantation of the solvent therefrom to form the catalyst.
Inventors: |
Epstein, Ronald A.; (Upper
Montclair, NJ) ; Wallack, William T.; (Ossining,
NY) |
Correspondence
Address: |
Richard P. Fennelly
Akzo Nobel Inc.
7 Livingstone Avenue
Dobbs Ferry
NY
10522-3408
US
|
Family ID: |
25301864 |
Appl. No.: |
09/847932 |
Filed: |
May 3, 2001 |
Current U.S.
Class: |
502/127 ;
502/102; 502/103; 502/118; 502/125 |
Current CPC
Class: |
C08F 110/06 20130101;
C08F 10/00 20130101; C08F 110/06 20130101; C08F 10/00 20130101;
C08F 110/06 20130101; C08F 2500/15 20130101; C08F 2500/18 20130101;
C08F 4/6548 20130101; C08F 2500/18 20130101 |
Class at
Publication: |
502/127 ;
502/118; 502/102; 502/103; 502/125 |
International
Class: |
B01J 031/00 |
Claims
We claim:
1. A process for forming a propylene polymerization catalyst which
comprises: forming a combination of titanium tetrachloride, a
magnesium-containing compound that can be converted to magnesium
dihalide and an internal electron donor in an alkylbenzene solvent,
with the proviso that, the magnesium-containing compound cannot be
a magnesium dialkoxide when the internal donor is a halo phthaloyl
derivative, and bringing that combination to elevated temperature
to form an intermediate product; washing the intermediate product
with an aromatic hydrocarbon solvent at elevated temperature to
produce a washed product and a supernatant followed by decantation
of the supernatant therefrom; treating the washed product with
titanium tetrachloride in an alkylbenzene solvent to form a treated
product and a supernatant followed by heating of the treated
product and supernatant, decantation of the supernatant therefrom,
and washing of the treated product with an aromatic hydrocarbon
solvent at elevated temperature; to produce a washed product and a
supernatant followed by decantation of the supernatant therefrom;
treating the washed product with titanium tetrachloride in an
alkylbenzene solvent, at least one more time, to form a treated
product and a supernatant followed by heating of the treated
product and supernatant, decantation of the supernatant therefrom;
and addition of an aliphatic hydrocarbon solvent to the treated
product with decantation of the solvent therefrom to form a washed
product which can be used as a propylene polymerization
catalyst.
2. A process as claimed in claim 1 wherein, after the formation of
the washed product resulting from addition of the aliphatic
hydrocarbon solvent, and addition of mineral oil is added to the
washed product forming a slurry containing the propylene
polymerization catalyst.
3. A process as claimed in claim 1 wherein the alkylbenzene solvent
is toluene.
4. A process as claimed in claim 1 wherein the magnesium-containing
compound that can be converted to magnesium dihalide is a magnesium
chloroalkoxide that contains up to about twelve carbon atoms in its
alkyl moiety.
5. A process as claimed in claim 1 wherein the internal electron
donor is a phthalate ester that contains up to about twelve carbon
atoms in its alkyl groups.
6. A process as claimed in claim 1 wherein the alkylbenzene solvent
is toluene, the magnesium chloroalkoxide is magnesium
chloroethoxide, and the phthalate ester contains up to about twelve
carbon atoms in its alkyl groups.
7. A process as claimed in claim 2 wherein the alkylbenzene solvent
is toluene.
8. A process as claimed in claim 4 wherein the magnesium
chloroalkoxide contains up to about twelve carbon atoms in its
alkyl moiety.
9. A process as claimed in claim 5 wherein the phthalate ester
contains up to about twelve carbon atoms in its alkyl groups.
10. A process as claimed in claim 1 wherein the alkylbenzene
solvent is toluene, the magnesium-containing compound that can be
converted to magnesium dihalide is a magnesium chloroalkoxide, and
the internal electron donor is a phthalate ester that contains up
to about twelve carbon atoms in its alkyl groups.
11. A catalyst for the polymerization of propylene which comprises
a titanium compound having at least one titanium-halogen bond which
is supported on an activated, amorphous magnesium dihalide support
that is essentially free of alkoxy functionality, said catalyst
having the following physical parameters: weight percent
titanium--less than 2%; weight percent phthalate ester--from about
10% to about 25%; phthalate ester to titanium molar ratio--from
about 0.9 to about 2; weight percent magnesium--from about 14% to
about 23%; magnesium to titanium molar ratio--from about 7 to about
30; surface area--from about 250 m.sup.2/gm to about 500
m.sup.2/gm; pore volume--from about 0.2 cc/gm to about 0.5 cc/gm;
and average pore diameter--no more than about 50 Angstroms.
12. A catalyst for the polymerization of propylene which comprises
a titanium compound having at least one titanium-halogen bond which
is supported on an activated, amorphous magnesium dihalide support
that is essentially free of alkoxy functionality, said catalyst
having the following physical parameters: weight percent
titanium--from about 1% to less than 2.0%; weight percent phthalate
ester--from about 10% to about 20%; phthalate ester to titanium
molar ratio--from about 1 to about 1.9; weight percent
magnesium--from about 18% to about 21%; magnesium to titanium molar
ratio--from about 14 to about 29; surface area--from about 300
m.sup.2/gm to about 500 m.sup.2/gm; pore volume--from about 0.2
cc/gm to about 0.4 cc/gm; and average pore diameter--no more than
about 35 Angstroms.
13. A catalyst for the polymerization of propylene which comprises
a titanium compound having at least one titanium-halogen bond which
is supported on an activated, amorphous magnesium dihalide support
that is essentially free of alkoxy functionality, the titanium
metal content in the catalyst being less than 2 wt %, based on the
weight of the support, and a phthalate ester donor, the surface
area of the catalyst ranging from about 250 m.sup.2/gm to about 500
m.sup.2/gm.
14. A catalyst as claimed in claim 13 wherein the magnesium
dihalide support is derived from a magnesium chloroalkoxide that
contains up to about twelve carbon atoms in its alkyl moiety.
15. A catalyst as claimed in claim 13 wherein the phthalate ester
donor contains up to about twelve carbon atoms in its alkyl groups.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to the synthesis of a catalyst for
the polymerization of propylene. This catalyst has high activity,
and produces a polymer product having high stereospecificity and
high bulk density. The catalyst's activity is long lived and it
shows a good temperature response. All of these features are
desirable for a commercial propylene polymerization catalyst.
SUMMARY OF THE INVENTION
[0002] The present invention relates to a process for forming a
propylene polymerization catalyst. This process, in general terms,
comprises: forming a combination of titanium tetrachloride, a
soluble or insoluble magnesium-containing compound that can be
converted to magnesium dihalide, such as a magnesium
chloroalkoxide, and an internal electron donor, such as phthalate
ester, in an alkylbenzene solvent and bringing that combination to
elevated temperature to form an intermediate product which is
separated by, for example decantation; washing the intermediate
product with an aromatic hydrocarbon solvent at elevated
temperature to produce a washed product and a supernatant followed
by decantation of the supernatant therefrom; treating the washed
product with titanium tetrachloride in an alkylbenzene solvent,
preferably two or three more times, to form a treated product and a
supernatant followed by heating of the treated product and
supernatant, decantation of the supernatant therefrom, and washing
of the treated product with an aromatic hydrocarbon solvent at
elevated temperature, as previously described, with separation of
the desired product (for example, also by decantation); and
addition of an aliphatic hydrocarbon solvent to the treated product
with decantation of the solvent therefrom to form a washed product
which can be used as a propylene polymerization catalyst,
optionally after the addition of mineral oil to the washed product
to form a slurry containing the catalyst.
[0003] The soluble or insoluble magnesium-containing compound that
can be converted to magnesium dihalide can be selected from one or
more of the following types of compound: magnesium dialkoxides
(e.g., magnesium diethoxide); chloromagnesium alkoxides (e.g.,
chloromagnesium ethoxide); magnesium dihalide electron donor
adducts (e.g., MgCl.sub.2(EtOH).sub.x and MgCl.sub.2(THF).sub.x,
where THF is tetrahydrofuran and x in both cases is .gtoreq.0.5;
alkylmagnesium halides ("Grignards", such as chlorobutylmagnesium;
and dialkylymmagnesium compounds, such as butylethylmagnesium. In
all the foregoing classes of compound, the number of carbon atoms
in the alkoxide/alkyl moiety or moieties, as appropriate, will
range from one to about twelve, preferably four. Any of such
precursors can be supported on an inert carrier, such as
silica.
[0004] The internal electron donor can be selected from the known
types of internal donor including the following classes: the
phthalates and their derivatives; the benzoates and their
derivatives; the silanes and siloxanes; and the polysilanes and
polysiloxanes.
[0005] In accordance with the present invention, the selected
magnesium dichloride source compound cannot be a magnesium
dialkoxide when the selected internal donor is a halo phthaloyl
derivative.
[0006] The process of this invention produces a polymerization
catalyst that comprises a titanium compound having at least one
titanium-halogen bond that is supported on an activated, amorphous
magnesium dihalide support that is essentially free of alkoxy
functionality, the titanium metal content in the catalyst
preferably being no more than about 2 wt %, based on the weight of
the support, and an internal donor, such as a phthalate ester
donor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] While the following description focuses upon a certain
preferred magnesium dihalide source material, namely,
chloromagnesium ethoxide and internal donor (diisobutyl phthalate),
it is to be understood that the broader possibilities for the
selection of each, just described hereinabove, can be utilized in
place of these two selections.
[0008] The catalyst of the present invention is made using a series
of multiple treatment cycles, each of which involves the reaction
of mixtures of titanium tetrachloride and an alkylbenzene solvent,
such as toluene, with a support precursor followed by treatment of
the solid with alkylbenzene solvent. These reaction steps are
carried out at elevated temperature. During the first titanium
tetrachloride/alkylbenzene solvent reaction step, an internal
phthalate ester donor, such as the preferred di-isobutylphthalate,
is added. If the ultimate polymer product that is to be produced is
to have desirable particle size and morphology characteristics, an
appropriate particle size and morphology-controlled support
precursor needs to be used. The treatment cycles then need to be
carried out in such a manner as to preserve these features in the
final catalyst so that the polymer product replicates those
features.
[0009] The initial step of the process of the present invention
involves forming a combination of titanium tetrachloride, magnesium
chloroalkoxide, for example, and phthalate ester in an alkylbenzene
solvent and bringing that combination to elevated temperature to
form an intermediate product. The preferred magnesium
chloroalkoxide will contain from one to about twelve carbon atoms
in the alkyl moiety therein. The most preferred magnesium
chloroalkoxide is magnesium chloroethoxide. Toluene has been found
to be a preferred alkylbenzene solvent, with xylene, ethylbenzene,
propylbenzene, isopropylbenzene, and trimethylbenzene also being
useful. The preferred phthalate ester may contain from one to about
twelve carbon atoms in the alkyl groups therein, with
representative compounds including dimethyl phthalate, diethyl
phthalate, di-n-propyl phthalate, di-isopropyl phthalate,
di-n-butyl phthalate, di-butyl phthalate, di-tert-butyl phthalate,
diisoamyl phthalate, di-tert-amyl phthalate, di-neopentyl
phthalate, di-2-ethylhexyl phthalate, and di-2-ethyldecyl
phthalate. The donor can be added at room temperature to the other
components and the mixture can then be brought to elevated
temperature (for example, at about 100.degree. C. to about
140.degree. C., preferably from about 110.degree. C. to about
120.degree. C.) or it can be added to the other two components
either at room temperature and heated up to about 100.degree. C. or
can be added to those components after they have been heated to a
desired temperature. The amount of titanium tetrachloride to
alkylbenzene solvent will generally range from about 40% to 80% on
a volume basis and, generally, from about three to about four
treatment steps have been found to be adequate. The volume of
titanium tetrachloride and solvent to grams of support precursor
that is employed will generally be from about 5 to about 10
milliliters of titanium tetrachloride and solvent per gram of
support precursor. The combination of components is preferably held
together for up to about ten hours, preferably from about one to
about two hours and is agitated. The intermediate solid product
from this initial reaction step is then recovered after the
supernatant is decanted.
[0010] The intermediate product from the initial step is then
washed with an aromatic hydrocarbon solvent, such as an
alkylbenzene solvent (for example, toluene), at elevated
temperature (e.g., from about 100.degree. C. up to the boiling
point of the solvent) to produce a washed product and a supernatant
phase. The washing can be practiced in up to about three separate
washing steps. The supernatant in each washing step is decanted
from the washed product. This washing serves to remove undesirable
by-products that contain titanium. The volume of alkylbenzene
solvent that is used per gram of support precursor in this step
will generally range from about 5 to about 25 milliliters per
gram.
[0011] The washed product from the preceding step is then treated
with titanium tetrachloride in an alkylbenzene solvent of the type
previously described under the previously described conditions to
form a treated product and a supernatant. This step converts
unreacted alkoxide moieties of the starting magnesium
chloroalkoxide reagent and extracts undesired titanium-containing
by-products. This combination is then heated (e.g., at from about
100.degree. C. to about 140.degree. C.) followed by decantation of
the supernatant phase that exist and washing of the treated product
with an aromatic hydrocarbon solvent, preferably in a washing cycle
of from one to two step(s) each.
[0012] After the desired number of treatment/wash cycles, the
product from the preceding step then has an aliphatic hydrocarbon
solvent, such as hexane, added to it with decantation of the
resulting supernatant phase therefrom. Washing of the catalyst with
aliphatic solvent (e.g., up to about 3-8 separate washing steps)
serves to remove free titanium tetrachloride and residual aromatic
solvent. This forms a washed product that can be used as the
catalyst.
[0013] An optional final step is the addition of mineral oil to the
washed product from the preceding step to form a mineral
oil/catalyst slurry that can be employed as the propylene
polymerization catalyst. Drying of this slurry is usually avoided
since it can result in a substantial decrease in catalyst activity
(e.g., up to as much as 50%).
[0014] The catalyst composition that can be formed from the
previously described process appears to be a novel composition of
matter in certain embodiments. It comprises a titanium compound
having at least one titanium-halogen bond which is supported on an
activated, amorphous magnesium dihalide support that is essentially
free of alkoxy functionality. In its broadest embodiment, the
catalyst composition has the following physical parameters: weight
percent titanium--from about 1% to about 4%; weight percent
phthalate ester--from about 10% to about 25%; phthalate ester to
titanium molar ratio--from about 0.9 to about 2; weight percent
magnesium--from about 14% to about 23%; magnesium to titanium molar
ratio--from about 7 to about 30; surface area--from about 250
m.sup.2/gm to about 500 m.sup.2/gm; pore volume--from about 0.2
cc/gm to about 0.5 cc/gm; and average pore diameter--no more than
about 50 Angstroms.
[0015] More preferred embodiments of the catalyst composition have
the following physical parameters: weight percent titanium--less
than about 2.0%, most preferably from about 1% to about 2.5%, ;
weight percent phthalate ester--from about 10% to about 20%;
phthalate ester to titanium molar ratio--from about 1 to about 1.9;
weight percent magnesium--from about 18% to about 21%; magnesium to
titanium molar ratio--from about 14 to about 29; surface area--from
about 300 m.sup.2/gm to about 500 m.sup.2/gm; pore volume--from
about 0.2 cc/gm to about 0.4 cc/gm; and average pore-diameter--no
more than about 35 Angstroms.
[0016] The Examples that follow are provided to illustrate certain
preferred embodiments of the invention.
EXAMPLE 1
Catalyst Preparation
[0017] In a nitrogen filled dry box, 10.0 g of a mixed phase
ClMg(OEt) was charged into a 500 ml 4-neck round bottom flask. The
flask was fitted with a mechanical stirrer, nitrogen inlet adapter,
condenser with nitrogen outlet adapter, and septum, and removed
from the dry box to a Schlenk line. Then, 30 ml of dry toluene was
added, the mixture was stirred to suspend the solid, and 20 ml of
TiCl.sub.4 was added to the stirred slurry at a rate that
maintained the temperature .ltoreq.25.degree. C. The slurry was
heated to 70.degree. C. and 3.78 g of diisobutylphthalate was
added. The mixture was heated to 115.degree. C. and was held at
this temperature for two hours.
[0018] At the end of the reaction, the agitation was stopped and
the solids were allowed to settle. The supernatant was decanted,
200 ml of toluene was added, the reaction media was heated to just
below reflux, and was held for fifteen minutes at this temperature.
The solids were then allowed to settle and the supernatant was
decanted. The toluene treatment was then repeated.
[0019] Then, 30 ml of toluene and 20 ml of TiCl.sub.4 were added,
the media was heated to 115.degree. C., and was held for one hour.
After allowing the solids to settle, the liquid was decanted, and
the solids were treated twice with 200 ml of toluene as described
above. After these treatments, the sequence of the
TiCl.sub.4-toluene reaction and two toluene treatments was repeated
twice. After the last toluene decant, the solids were washed five
times with 100 ml each of hexane. The catalyst was then isolated as
a slurry.
[0020] Analysis of the solid catalyst component showed it to
contain 21 wt % Mg and 1.5 wt % Ti.
Catalyst Testing
[0021] A 4 liter autoclave equipped with an agitator was purged
with nitrogen until oxygen and water have been reduced to
acceptable levels. Then, under a N.sub.2 purge, 50 ml of purified
hexane was added to the reactor, followed by 7.0 mmole of TEAL and
0.48 mmole of dicyclopentyldimethoxy-silane. The catalyst slurry
prepared above, containing 4 to 6 mg of the solid catalyst, was
added to 45 ml of purified hexane and then was added to the
reactor. The reactor was closed and 2.5 1 of purified propylene was
added, followed by 3.6 1 (STP) of H.sub.2. The contents of the
reactor were stirred and were heated to 70.degree. C. The reaction
mixture was maintained at 70.degree. C. for one or two hours. The
reactor was then vented and cooled.
[0022] The resulting polymer was collected and dried. The polymer
was weighed and an activity, defined as kg polymer/g catalyst
charged was calculated. The polymer poured bulk density (PBD) and
total xylene insolubles (TXI) were measured. The controlled
particle size distribution and morphology of the starting support
precursor was maintained in the polymer particles. The results of
these tests were shown in Table 1. In many cases, 2-3 tests were
run on each catalyst and the average results of these tests were
reported.
EXAMPLE 2
[0023] A catalyst preparation was carried out using the procedure
described in Example 1, except that 25 ml of toluene and 25 ml of
TiCl.sub.4 were used in the reaction steps. Analysis of the solid
catalyst component showed it to contain 21 wt % Mg and 1.5 wt % Ti.
Testing was carried out as described in Example 1, and the results
are shown in Table 1, below.
EXAMPLE 3
[0024] A catalyst preparation was carried out using the procedure
described in Example 1, except that 20 ml of toluene and 30 ml of
TiCl.sub.4 were used in the reaction steps, and only 1.times.200 ml
toluene treatment was used after each TiCl.sub.4/toluene reaction.
Analysis of the solid catalyst component showed it to contain 19 wt
% Mg and 1.8 wt % Ti. Testing was carried out as described in
Example 1, and the results are shown in Table 1, below.
EXAMPLE 4
[0025] A catalyst preparation was carried out using the procedure
described in Example 1, except that the reactor was a 250 ml round
bottom flask, 10 ml of toluene and 40 ml of TiCl.sub.4 were used in
the reaction steps, and 2.times.100 ml toluene treatments were used
after each TiCl.sub.4/toluene reaction. Analysis of the solid
catalyst component showed it to contain 19 wt % Mg and 1.6 wt % Ti.
Testing was carried out as described in Example 1, and the results
are shown in Table 1, below.
EXAMPLE 5
[0026] A solid catalyst component was synthesized following the
procedure described in Example 1, except that the reactor was a 250
ml round bottom flask and 2.times.100 ml toluene treatments were
used after each TiCl.sub.4/toluene reaction step. Analysis of the
solid catalyst component showed it to contain 19 wt % Mg and 1.5 wt
% Ti. Testing was carried out as described in Example 1, and the
results are shown in Table 1, below.
EXAMPLE 6
[0027] The procedure described in Example 1 was used to prepare a
catalyst, except that the reactor was a 250 ml round bottom flask
and one 100 ml toluene treatment was used after each
TiCl.sub.4/toluene reaction step. Analysis of the solid catalyst
component showed it to contain 17 wt % Mg and 3.0 wt % Ti. Testing
was carried out as described in Example 1, and the results are
shown in Table 1, below.
EXAMPLE 7
[0028] A catalyst preparation was carried out using the procedure
described in Example 3, except that the reactor was a 250 ml round
bottom flask and 2.times.100 ml toluene treatments were used after
each TiCl.sub.4/toluene reaction step. Analysis of the solid
catalyst component showed it to contain 20 wt % Mg and 1.7 wt % Ti.
Testing was carried out as described in Example 1, and the results
are shown in Table 1, below.
EXAMPLE 8
[0029] A solid catalyst component was synthesized following the
procedure described in Example 3, except that the reactor was a 250
ml round bottom flask and 1.times.100 ml toluene treatment was used
after each TiCl.sub.4/toluene reaction step. Analysis of the solid
catalyst component showed it to contain 17 wt % Mg and 2.9 wt % Ti.
Testing was carried out as described in Example 1, and the results
are shown in Table 1, below.
EXAMPLE 9
[0030] A catalyst preparation was carried out using the procedure
described in Example 1, except that 40 ml of toluene and 60 ml of
TiCl.sub.4 were used in each reaction step. Analysis of the solid
catalyst component showed it to contain 20 wt % Mg and 1.2 wt % Ti.
Testing was carried out as described in Example 1, and the results
are shown in Table 1, below.
EXAMPLE 10
[0031] A catalyst preparation was carried out using the procedure
described in Example 1, except that 60 ml of toluene and 40 ml of
TiCl.sub.4 were used in each reaction step. Analysis of the solid
catalyst component showed it to contain 20 wt % Mg and 1.5 wt % Ti.
Testing was carried out as described in Example 1, and the results
are shown in Table 1, below.
EXAMPLE 11
[0032] An aliquot of the catalyst slurry prepared in Example 9 was
dried under vacuum. The test procedure described in Example 1 was
followed except that the dry catalyst is added to the 45 ml of
hexane instead of a slurry. The results are found in Table 1,
below.
EXAMPLE 12
[0033] A catalyst preparation was carried out using the procedure
described in Example 3, except that the reactor was a 250 ml round
bottom flask, and three series of TiCl.sub.4-toluene reactions and
1.times.100 toluene treatments are used. Analysis of the solid
catalyst component showed it to contain 15 wt % Mg and 3.8 wt % Ti.
Testing was carried out as described in Example 1, and the results
are shown in Table 1, below.
EXAMPLE 13
[0034] A catalyst preparation was carried out using the procedure
described in Example 1, except that the reactor was a 250 ml round
bottom flask, and three series of TiCl.sub.4-toluene reactions and
1.times.100 toluene treatments were used.
[0035] Analysis of the solid catalyst component showed it to
contain 15 wt % Mg and 3.8 wt % Ti. Testing was carried out as
described in Example 1, and the results are shown in Table 1,
below.
EXAMPLE 14
[0036] In this Example, 5.0 g of a mixed phase ClMg(OEt) was
charged into a 250 ml 4-neck round bottom flask as described in
Example 1. Then, 30 ml of toluene was added, the mixture was
stirred to suspend the solid, 20 ml of TiCl.sub.4 was added to the
stirred slurry, the slurry was heated to 90.degree. C., and 1.95 g
of di-isobutylphthalate was added. The mixture was heated to
115.degree. C. and was held at this temperature for two hours.
[0037] Following the procedure in Example 1, the supernatant was
decanted, and two treatments with 100 ml of toluene each were
carried out. The TiCl.sub.4+toluene reaction/toluene treatment step
were repeated three additional times. The solids were then washed
four times with 100 ml heptane each time. An additional 100 ml of
heptane was added to the flask, the slurry was transferred to a
vacuum filter apparatus, filtered and dried.
[0038] Analysis of the solid catalyst component showed it to
contain 21 wt % Mg and 1.3 wt % Ti. Testing was carried out as
described in Example 1, except that the dry catalyst was added to
the 45 ml of hexane instead of a slurry. The results are shown in
Table 1, below.
EXAMPLE 15
[0039] A slurry of a solid catalyst component was prepared in then
same manner as Example 14 with the exception that the
di-isobutylphthalate was added at room temperature after the
addition of the initial TiCl.sub.4 charge. Analysis of the solid
catalyst component showed it to contain 20 wt % Mg and 1.4 wt % Ti.
Polymerization testing results, obtained under the same conditions
as shown in Example 1, are found in Table 1, below.
EXAMPLE 16
[0040] A portion of the catalyst slurry obtained in Example 15 was
filtered and vacuum dried. Table 1 contains the polymerization test
results for this catalyst, carried out under the conditions of
Example 1, modified for the use of dry catalyst as in Example 11.
The results of this Example are not illustrated in Table 1.
EXAMPLE 17
[0041] The catalyst prepared in Example 1 was tested for
polymerization performance as in Example 1, except that the test is
run at 80.degree. C. for one hour. The averaged results of two
tests were as follows: activity, 132.6 kg/g catalyst; poured bulk
density, 0.474 g/ml; total xylene insolubles, 99.37 wt %.
[0042] Comparative Example 1
[0043] The procedure described in Example 12 was followed to
produce a solid catalyst component except that 1.43 g of phthaloyl
dichloride was substituted for diisobutyl-phthalate. The results of
polymerization testing using the procedure in Example 1, modified
for the use of dry catalyst as in Example 11, are presented in
Table 1, below.
Comparative Example 2
[0044] A catalyst preparation was carried out using the procedure
described in Example 1, except that 40 ml of toluene and 10 ml of
TiCl.sub.4 were used in the reaction steps. Analysis of the solid
catalyst component showed it to contain 22 wt % Mg and 0.69 wt %
Ti. Testing was carried out as described in Example 1, and the
results are shown in Table 1, below.
1TABLE 1 Catalyst Performance Results yield # Tests time of kg/g
PBD TXI Example # averaged run, hr cat g/ml wt % 1 3 1 85.5 0.468
98.82 1 1 2 120.6 0.473 98.93 2 2 1 74.3 0.458 98.96 3 2 1 76.4
0.479 98.86 4 2 1 66.9 0.487 98.95 5 2 1 80.9 0.472 98.96 6 2 1
77.5 0.467 98.99 7 3 1 69.1 0.483 98.96 8 3 1 69.5 0.470 98.88 9 3
1 69.1 0.470 99.03 9 1 2 100.2 0.478 98.95 10 2 1 60.7 0.453 98.78
11 2 1 46.3 0.410 98.88 12 2 1 53.5 0.472 98.49 13 2 1 65.0 0.457
99.00 14 3 1 48.6 0.428 99.04 15 1 1 87.9 0.424 98.80 16 2 1 66.0
0.359 98.67 Comp. 1 1 1 20.7 0.460 99.33 Comp. 2 2 1 35.9 0.407
99.37
EXAMPLE 18
[0045] In this Example, 5.0 g of a pure phase ClMg(OEt), as
described in U.S. Pat. No. 5,262,573, was slurried with 30 ml of
toluene and 20 ml of TiCl.sub.4. The slurry was heated to
90.degree. C. and 1.94 g of di-isobutylphthalate was added. The
remainder of the process was then carried out as described in
Example 1, using 100 ml of toluene for the treatment steps and 30
ml of toluene and 20 ml of TiCl.sub.4 for the reaction steps. The
product was washed with heptane and isolated by vacuum drying.
[0046] Testing was carried out as described in Example 1, and the
results are shown in the following Table:
2 # Tests time of yield PBD TXI averaged run, hr kg/g cat g/ml wt %
3 1 68.5 0.386 98.62
[0047] The foregoing Examples illustrate the following features and
performance characteristics of the catalyst. Examples 1-8 describe
modes for preparing the catalyst along with the effects of varying
the TiCl.sub.4/toluene ratio and number and volume of toluene
treatments. Example 1 versus Example 9, and Example 3 and 7 versus
Example 10 show the benefit of reducing the volume of the
TiCl.sub.4/toluene reaction mixture from 10 ml/g support precursor
(Examples 9 and 10) to 5 ml/g support precursor (Examples 1, 3, and
7).
[0048] Example 9 versus Example 11 illustrates the improvement in
catalyst performance when the catalyst is not dried and is isolated
as a slurry versus isolation as a dry powder. Example 3 versus 12
and Example 6 versus 13 exhibit the difference found for carrying
out four versus three treatment cycles. Example 9 versus Example 15
compares the effects of the temperature of addition of the
diisobutylphthalate (DIBP) internal donor, 70.degree. C. versus
room temperature, for catalysts isolated as slurries (room
temperature, higher activity).
[0049] Examples 14, 11, and 16 show the effect of the temperature
of addition of the DIBP internal donor, 90.degree. C. versus
70.degree. C. versus room temperature, for catalysts isolated as
dry powders (room temperature, higher activity).
[0050] Example 17 shows the increase in activity achieved when the
polymerization test is run at 80.degree. C. instead of 70.degree.
C.
[0051] Example 18, which is best compared to Example 11 that used a
mixed phase ClMg(OEt) support precursor, shows the present
invention using, as a starting reagent, a pure phase ClMg(OEt)
material. The activity of the catalyst was almost 50% greater than
that for the mixed phase support material.
[0052] Example 14 versus Comparative Example 1 shows the use of a
phthalate ester, DIBP in this case, gives a superior catalyst to
the use of the corresponding acid chloride, phthaloyl dichloride,
when ClMg(OEt) is the support precursor (dry catalyst).
[0053] Comparative Example 2 versus Examples 1-4, shows that
reducing the volume % of TiCl.sub.4 in the TiCl.sub.4/toluene
reaction mixture from 40% to 20% causes a large loss in activity,
not evident from the trend found in the 80%-40% range.
[0054] The foregoing Examples, since they are being provided to
merely illustrate certain embodiments of the present invention,
should not be construed in a limiting fashion. The scope of
protection sought is set forth in the claims that follow.
* * * * *