Note: Descriptions are shown in the official language in which they were submitted.
12Z'7~7~15
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K 45~8 CAN
OLEFIN POLYMERIZATION CATALYST COMPOSITIONS
AND POLYMERIZATION PROCESS
This invention relates to olefin polymerization catalyst
components comprising a magnesium halide and a titanium halide
and to a process for the polymerization of olefins using such
catalyst components.
Numerous proposals are known from the prior art to provide
olefin polymerization catalysts by combining a solid component
comprising magnesium, titanium and chlorine with an activating
organoaluminium compound. These may be referred to as supported
coordination catalysts or catalyst systems. The activity and
stereo specific performance of such compositions is generally
improved by incorporating an electron donor (Lewis base) in the
solid component and by employing as a third catalyst component
an electron donor which may be complexes in whole or in part
with the activating organoaluminium compound.
For convenience of reference, the solid titanium-containing
constituent of such catalysts is referred to herein as "pro-
catalyst", the organoaluminium compound, whether used separately
or partially or totally complexes with an electron donor, as
"cocatalyst", and the electron donor compound, whether used
separately or partially or totally complexes with the organ-
aluminum compound, as "selectivity control agent" (SPA).
The catalyst systems of this type which have been disclosed
in the prior art generally are able to produce olefin polymers
in high yield and, in the case of catalysts for polymerization
of propylene or higher alpha-olefins, with high selectivity to
stereo regular polymer. However, further improvements in pro-
ductility at high stereo regularity are still being sought.
~ZZ77~5
The objective of workers in this art is to provide catalyst
systems which exhibit sufficiently high activity expressed in
terms of kg polymer produced per g To (kg polliwog To), to permit
the production of polyolefins in such high yield as to obviate
the necessity of extracting residual catalyst components in a
dashing step. In the case of propylene and higher olefins, an
equally important objective is to provide catalyst systems of
sufficiently high selectivity toward isotactic or otherwise
stereo regular products to obviate the necessity of extracting
tactic polymer components.
Suitable pro catalysts have been disclosed which comprise
Ida. a composition prepared by halogenating a magnesium
compound MgR'R" (wherein R' and R" are alkyd, aureole, alkoxide.
or aryloxide groups and R" may also be a halogen) by reaction
with a halide of tetravalent titanium in the presence of an
electron donor and a halo hydrocarbon followed by contact of the
halogenated product with a tetravalent titanium compound.
This invention provides still further improvements of the
catalysts and processes of the prior art. Catalysts which
comprise the solid titanium-containing catalyst constituents of
this invention in combination with an organoaluminium cocatalyst
and a selectivity control agent or with an at least partial
reaction product of an organoaluminium compound and a
selectivity control agent are capable of producing polypropylene
of commercially desired isotacticity at very high activity.
This invention provides a process for producing an improved
olefin polymerization catalyst component. which comprises:
a) halogenating a magnesium compound of the formula MgR'R"
where R' is an alkoxide or aryloxide group an R" is an
alkoxide or aryloxide group or halogen, with a tetravalent
titanium halide in the presence of a halo hydrocarbon and an
electron donor, therein forming a halogenated product; this
halogenated product being subjected to a contacting treat-
mint selected from
A
~;~Z7~7151~
b) 1. contacting an acid halide of the formula
A C - X
where A is an alkyd, aureole, substituted alkyd, or
substituted aureole group and X is a halide at a temperature
of about 40 to about 140 C; followed by contacting
the resulting acid halide-treated product with a
tetravalent titanium halide at a temperature of from 40 to
140 C, and
2. contacting with a mixture of the alone said acid halide
and a tetravalent titanium halide at a temperature of from
40 to 140 C.
The first step in preparing the pro catalysts of the present
invention comprises halogenating a magnesium compound of the
formula MgR'R" where R' is an alkoxide or aryloxide group an R"
is an alkoxide or aryloxide group or halogen, with a tetravalent
titanium halide in the presence of a halo hydrocarbon and an
electron donor, therein forming a halogenated product.
Examples of halogen containing magnesium compounds that can
be used as starting materials for the halogenating reaction are
alkoxy and airlocks magnesium halides, such as isobutoxy
magnesium chloride, ethics magnesium bromide, phonics magnesium
iodide, cumyloxy magnesium bromide and naphtenoxy magnesium
chloride.
Preferred magnesium compounds to be halogenated are
selected from magnesium dialkoxides and magnesium diaryloxides.
In such compounds the alkoxide groups suitable have from 1 to 8
carbon atoms, and preferably from 2 to 8 carbon atoms. Examples
of these preferred groups of compounds are magnesium dyes-
prop oxide, magnesium diethoxide, magnesium dibutoxide, magnesium
diphenoxide, magnesium dinaphtenoxide and ethics magnesium
isobutoxide. Magnesium diethoxide is particularly preferred.
-~lZ~77l~
Magnesium compounds comprising one alkyd group and one
alkoxide or aryloxide group also be employed, as well as come
pounds comprising one aureole group and one alkoxide or aryloxide
group. Examples of such compounds are phenol magnesium phenol
wide, ethyl magnesium but oxide, ethyl magnesium phenoxide andnaphthyl magnesium isoamyloxide.
In the halogenation with a halide of tetravalent titanium,
the magnesium compounds are preferably reacted to form a
magnesium halide in which the atomic ratio of halogen to
magnesium it at least 1.2. Better results are obtained when the
halogenation proceeds more completely, i.e., yielding magnesium
halides in which the atomic ratio of halogen to magnesium is at
least 1.5. The most preferred reactions are those leading to
fully halogenated reaction products. Such halogenation reactions
are suitably effected by employing a molar ratio of magnesium
compound to titanium compound of 0.005:1 to 2:1, preferably
0.01:1 to 1:1. These halogenation reactions are conducted in the
additional presence of an halo hydrocarbon and an electron donor.
An inert hydrocarbon delineate or solvent may also be present.
When using an inert delineate or solvent, this should of course
not be used as a complete substitute for the halo hydrocarbon.
Suitable halides of tetravalent titanium include airlocks-
or alkoxy-di- and -trihalides, such as dihexanoxy-tltanium
dichlorides diethoxy-titanium dibromide, isopropoxy-titanium
treaded and phenoxy-titanium trichloride; titanium twitter-
halides are preferred; most preferred is titanium tetrachloride.
Suitable halo hydrocarbons are compounds such as bottle
chloride, Amy chloride and the following more preferred come
pounds. Preferred aliphatic halo hydrocarbons are halogen-
substituted hydrocarbons with 1 to 12, particularly less than Caribbean atoms per molecule, comprising at least two halogen
atoms, such as dibromomethane, trichloromethane, 1,2-dichloro-
ethanes dichlorobutane, 1,1,3-trichloroethane, trichlorocyclo-
hexane, dichlorofluoroethane, trichloropropane, trichloro-
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fluorooctane, dibromodifluorodecane, he~achloroethane andtetrachloroisooctane. Carbon tetrachloride and l,l,3-tri-
chloroethane are preferred aliphatic halo hydrocarbons. Aromatic
halo hydrocarbons may also be employed, e.g., chlorobenzene,
bromobenzene, dichlorobenzene, dichlorodibromobenzene, naphthyl
chloride, chlorotoluene, dichlorotoluenes, and the like; sheller-
Bunsen ant dichlorobenzene are preferred aromatic holder-
carbons. Chlorobenzene is the most preferred halo hydrocarbon.
The halogenation normally proceeds under formation of a
solid reaction product which may be isolated from the liquid
reaction medium by filtration, recantation or another suitable
method and may be subsequently washed with an inert hydrocarbon
delineate, such as Nixon, iso-octane or Tulane, to remove any
unrequited material, including physically absorbed holder-
carbon.
The novel and unobvious aspect of the present invention
comprises treating the above halogenated product with a
particular acid halide prior to or concurrent with treatment
with a tetravalent titanium halide.
Acid halides employed herein have the formula
C X
where A is an alkyd, aureole, substituted alkyd or substituted aureole
group and X is a halide. Preferably, A is a phenol group and X
is chloride. Accordingly, the preferred acid halide is bouncily
chloride.
The acid halide treatment results in significantly improved
selectivity or equivalently a significant increase in polymeric
ration activity, measured as kg polliwog Tip over the activity of
untreated catalyst at the same selectivity. The amount of acid
halide employed is 50 to 200 Molly per mole of My and preferably
12~
less than the total equivalent amount of residual alkoxide
contained in the halogenated magnesium compound. Suitably, the
treatment is carried out at a temperature of 40 to 140 C during
0.1 to 4 hours. Particularly preferred contacting temperatures
are from 60 to 110 C and the most preferred contacting periods
are 0.3 to 1 hour.
The product is also contacted with a tetravalent titanium
compound such as a dialkoxy-titanium dwelled, alkoxy-titanium
troweled, phenoxy-titanium troweled or titanium tetrahalide,
either simultaneously with or subsequent to the contacting with
acid halide. The most preferred titanium compounds are titanium
tetrahalides and especially titanium tetrachloride. This treat-
mint increases the content of titanium tetrachloride in the
solid catalyst component. This increase should preferably be
sufficient to achieve a final atomic ratio of tetravalent
titanium to magnesium in the solid catalyst component of from
0.005 to 3.0, particularly of from 0.02 to 1Ø To this purpose
the contacting with the tetravalent titanium compound is most
suitably carried out at a temperature of from 60 to 136 I
during 0.1-6 hours, optionally in the presence of an inert
hydrocarbon delineate. Particularly preferred contacting
temperatures are from 70 to 120 C and the most preferred
contacting periods are in between 0.5 to 3.5 hours.
At the end the catalyst component is suitably isolated from
the liquid reaction medium and washed to remove unrequited
titanium compound. The titanium content of the final, washed
catalyst constituent it suitably between about 1.5 to 3.6
percent by weight or up to about 4.5 percent.
The preferred halogen atom, possibly contained in the
3 magnesium compound to be halogenated, and contained in the
titanium compound which serves as halogenating agent and in the
tetravalent titanium compound with which the halogenated product
is contacted, is chlorine.
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Suitable electron donors, which are used in combination
with or reacted with an organoaluminium compound as selectivity
control agents and which are also used in the preparation of the
solid catalyst component are ethers, esters, kittens, phenols,
amine, asides, mines, nitrites, phosphines, phosphates,
stubbiness, arsines, phosphoramides and alcoholates. Examples of
suitable donors are those referred to in US. Patent 4J136,243
or its equivalent British Specification 1,486,194 and in British
Specification 1,554,340 or its equivalent German Offenlegungs-
shrift 2,729,126. Preferred donors are esters and dominoes,
particularly esters of aromatic carboxylic acids, such as ethyl
and methyl bonniest, p-methoxy ethyl bonniest, p-ethoxy ethyl
bonniest, ethyl acrylate, methyl methacrylate, ethyl acetate,
dim ethyl carbonate, dim ethyl adipate, dihexyl fumarate, dibutyl
Malta, ethyl isopropyl oxalate, p-chloro ethyl bonniest,
p-amino Huxley bonniest, isopropyl naphtenate, namely twilight,
ethyl cyclohexanoate, propel pivalate, N,N,N',N'-tetramethyl-
ethylene Damon, 1,2,4-trimethyl piperazine, twitter-
methyl plperidine and similar compounds. The donor used as
selectivity control agent in the catalyst may be the same as or
different from the donor used for preparing the titanium
containing constituent. Preferred electron donors for use in
preparing the titanium constituent are ethyl bonniest and
p-methyl twilight. Preferred as selectivity control agent in the
total catalyst are p-methoxy ethyl bonniest and p-ethoxyethyl-
bonniest.
The organoaluminium compound to be employed as cocatalyst
may be chosen from any of the known activators in olefin polyp
merization catalyst systems comprising a titanium halide but is
most suitably free of halogens. While aluminum trialkyl come
pounds, dialkylaluminium halides and dialkylaluminium alkoxides
may be used, aluminiumtrialkyl compounds are preferred,
particularly those wherein each of the alkyd groups has 2 to 6
carbon atoms, e.g., aluminiumtriethyl, aluminiumtri-n-propyl,
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aluminiumtri-isobutyl, aluminiumtri-isopropyl and aluminum-
dibutyl-n-amyl.
Preferred proportions of selectivity control agent,
employed separately, in combination with, or reacted with an
organoaluminium compound, calculated as mow per mow aluminum
compound, are in the range from 0.1 to 1.5, particularly from
0.2 to 0.5.
Proportions of electron donor contained in the solid
catalyst component, calculated as mow per mow of magnesium, are
suitably in the range of from 0.01 to 10, e.g., from 0.05 to 10
and from 0.1 to 5.0 and especially from 0.8 to 2.2.
To prepare the final polymerization catalyst composition,
pro catalyst, cocatalyst and selectivity control agent, if used
separately, may be simply combined, most suitably employing a
molar ratio to produce in the final catalyst an atomic ratio of
aluminum to titanium of from 1 to 150, and suitably from about
10 to about 150. The catalysts of this invention tend to exhibit
very good activity at much lower Alto ratios, e.g., below 80:1
and even below 50:1, than prior art catalysts of the same type.
It may, however, be advantageous under some conditions to employ
them at higher Alto ratios. In general, Alto ratios in the
range of 30:1 to 100:1 and especially of about 50:1 to 80:1 will
be found advantageous.
Improved pro catalysts prepared according to this invention
are useful in the same types of polymerization of alpha-mono-
olefins in which the unimproved pro catalysts are useful. The
catalysts may be employed in the polymerization or Capella-
merization of alpha-monoolefins of 2 to 8 carbon atoms per
molecule, conducted at conditions known for the polymerization
of the respective olefins when using McCoy supported keyword-
nation catalysts.
Polymerization of propylene as sole olefin feed or in
combination with small amounts, e.g., from l to 20 mole percent,
of ethylene, button or other alpha olefin comonomer, may be
conducted with the catalysts of the invention, in a liquid
31 ~Z~5
g
system with an inert delineate such as a paraffinic liquid of 3 to
15 carbon atoms per molecule, or in a liquid system containing
propylene as sole delineate or together with a small amount of
propane, or in vapor phase. Propylene polymerization in liquid
phase is conducted at temperatures of 50 to 80 C and at a
pressure sufficient to maintain liquid conditions.
In propylene polymerization, the reaction mixture is
typically maintained at conditions at which the polymer is
produced as a slurry of powder in the reaction mixture. The
catalyst systems of this invention are extremely active and
highly stereo selective in propylene polymerization, so that no
removal of catalyst components or of tactic polymer from the
polymer product is required.
Olefin polymerization may also be conducted as a solution
process in which the polymer is produced as a solution in
monomer or delineate. Such a process is preferred in the polyp
merization of button as described, for example, in US. Patent
3,362,940.
The polymerization activity of the pro catalyst is
determined as kg polymer/g To in a standard one hour batch
reaction
The selectivity to isotactic polypropylene is determined by
measuring the amount of zillion soluble polymer (US), in
accordance with regulations of the US. Food and Drug
Administration. The US test is carried out as follows:
The sample is completely dissolved in zillion in a stirred flask
by heating under reflex at 120 C. The flask is then immersed in
a water bath at 25 C without stirring for one hour, during
which the insoluble portion precipitates. The precipitate is
3 filtered off and the solubles present in the filtrate are
determined by evaporating a 20 ml Alcott of the filtrate,
drying the residue under vacuum, and weighting the residue. The
xylene-solubles consist of amorphous material with some low
molecular weight crystalline material. (FDA regulations 121.2501
and 121.2510, 1971.)
sty
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The following examples illustrate the invention:
Examples 1-5
1. Magnesium ethoxide (5.72 g, 50 Molly) was stirred at room
temperature with ethyl bonniest (2.4 ml, 16.7 Molly) and 75 ml of
chlorobenzene as titanium tetrachloride (75 ml, 680 Molly) was
added over the course of 10 min. The mixture was brought to
110 C and stirred for 60 min. then filtered hot. The resulting
solid ("S") was slurries in chlorobenzene (60 ml) containing
bouncily chloride (0.31 ml, 2.7 Molly) and held at 110 C for 20
mix then filtered hot. The resulting solid was washed for 10
minutes each with two 60 ml portions of Tokyo at 110 C and
filtered hot. The resulting solid was washed at room temperature
with six 150 ml portions of isopentane then dried under moving
nitrogen at 40 C. Yield 5.77 g of pro catalyst "A".
2. Pro catalyst "B" was prepared by essentially the same
procedure except that the bouncily chloride treatment was carried
out for 60 min. at 110 C and that the two succeeding 110 C
TlC14 washes were with only 40 ml of titanium tetrachloride.
Yield 6.5 g.
3. Magnesium ethoxide (5.72 g, 50 Molly) was stirred at room
temperature with bouncily chloride ~1.8 ml, 15.6 Molly) and 75 ml
of chlorobenzene as titanium tetrachloride (75 ml, 680 Molly)
was added over the course of 10 min. The mixture was brought to
100 C and stirred for 180 min. when filtered hot. The
resulting solid was slurries in 40 ml of chlorobenzene and held
at 100 C for 120 min. then filtered hot. The resulting solid
was slurries in titanium tetrachloride (40 ml) containing
bouncily chloride (0.6 ml, 5.2 Molly) and held at 100 C for 120
min. then filtered hot. The resulting solid was washed at room
temperature with seven 150 my portions of isopentane then dried
under moving nitrogen at 40 C for 100 min. Yield 5.82 g of
pro catalyst "C".
4. Solid "S", as prepared in example 1, was slurries in 40 ml
of titanium tetrachloride and held at 110 C for 60 mix then
~2Z~785
filtered hot. The resulting solid was slurries in 40 ml of
titanium tetrachloride containing bouncily chloride (0.4 ml, 3.5
Molly) and held at 110 C for 60 mix then filtered hot. The
resulting solid was washed, at room temperature, with six 150 ml
portions of isopentane then dried under moving nitrogen at
40 C. Yield 6.2 g of pro catalyst "D".
5. (Control) Solid "S", as prepared in example l, was treated
three times with 40 ml of Tickle held at 110 C for lo mix each
and filtered hot. The resulting solid was washed, at room
temperature, with six 150 ml portions of isopentane then dried
under moving nitrogen at 40 C for 100 mix Yield 6.32 g of
pro catalyst "E".
All pro catalysts were subjected to a one-hour standard
propylene polymerization-test, which was conducted as follows:
About 1400 g of liquid propylene and 132 Molly of hydrogen
in a one gallon (about 4 liter) autoclave equipped with an
agitator, was heated to 60 C under sufficient pressure to
maintain it in liquid phase. A predetermined amount (Oily
Molly) of p-ethyl ethylbenzoate and 2.5 ml (0.7 Molly) of triethyl
aluminum as a 5% wit solution in C7-C8 paraffin delineate were
then succeccively added to the propylene. To the agitated
mixture there was added a sufficient amount of the slurry of
pro catalyst in mineral oil to provide 0.01 mealtimes of
titanium.
The mixture was agitated and maintained at 67 C.
The pressure was then released and powdered polypropylene
recovered.
For the five examples listed in Table 2 (examples 6-10) the
zillion solubles were analyzed to be from 3.8 to 4.8%. For
convenience of comparison the measured polymerization activities
were corrected to equivalent productivities at 4% zillion
solubles.
~l2'~7S2~
- 12 -
Activity
ProcatalystKg polliwog To
A 976
B 950
C 1040
D 994
Eye (control)
.
.
