Note: Descriptions are shown in the official language in which they were submitted.
~280~7
C-81?9 -1-
TRANSITION METAL CATALYST COMPONENT
CONTAINING MAGNESIUM ALKOXY ALKOXIDES
FI~LD OF THE INV~NTION
Thls invention i8 an improved magnesium supported
an~onic coordination cataly~t for the polymer~zation of
olefins.
BACRGROUND OF THE INVENTION
A great number of anionlc coordination catalyst
~ystem~ are based on the use of titanium based catalyst on a
ma~ne~lum chloride support.
A typical catalyst sy~tcm employing magnesium
chloride i8 disclosed ln Briti~h Patent 2,111,066 assigne~
to Mlt~ul Petrochemlcal Indu~trle~ ~td.
C-rtaln prlor art ~atent~ teach magneslum compound
su~ported Zi-gler-Natta type cataly~ts that do not directly
employ ma~neslum chlorlde ln cataly~t preparatlon. In
partlcular, U.S. Patent No, 3,644,318 d-~crlb~s a mixed
catalyst componont whlch i8 the reaction product of
magnesium alcoholates with tetravalent halo~enated titanium
compounds.
Other prior art patents using alkoxides as a
ma~nesium source for formation of an olefin polymerlzat~on
catalyst are U.S. Patent Nos. 4,144,390; 4,277,372;
4,460,701; ~,48S,186; 4, 497,905, and U.S. Rel~sue Patent
31,099.
It 18 the discovery of U.S. Patent No.
4,837,190, that highly organic solvent
soluble alcoholates of magne~ium can be prepared lf
magnesium is reacted with alkoxy alcohols. ~he re~ultant
alkoxy alcohol derivates of magnesium are readily soluble ln
~'i ~~
A
lZ80~17
C-8179 -2-
organic solvents such as hexane, heptane, toluene, xylene,
and etc.
The prior art does not recognize the advantageous use
of highly organic solvent soluble alkoxy alkoxides of
magnesium. Moreover, the prior art generally employs
halogenating agents other than the transition metal halides
which are normally part of the polymerization catalyst.
It i~ desirable to develop new anionic coordination
catalyst systems having novel sources of magnesium to serve
as support for titanium-based catalysts.
SUMMARY OF THE INVENTION
This invention is an anionic coordination catalyst
component formed from the reaction of an alkoxy alkoxide of
magnesium with titanium tetrachloride. Moreover, this
invention i~ an anlonic coordination cataly~t suitable for
the polymerlzation of oleflns, whlch catalyst 1~ prepared by
comblnlny ~) the reaction product of an alkoxy alkoxlde
magneslum compound and titanium tetrachloride with (ii) an
organoaluminum compound.
DETAILED DESCRIPTION OF THE INVENTION
The Ziegler-Natta type anionic coordination catalysts
are generally prepared by combining a transition metal
component with an aluminum co-catalyst. It is particularly
desirable to first form the titanium catalyst component and
then combine it with the aluminum co-catalyst ~ust prior to
the time of actual use. This invention enables the
formation of a first transition metal catalyst component
from the combination of titanium tetrahalide and a magnesium
alkoxy alkoxide without the presence of aluminum co-catalyst
or an extra halogenating agent ingredient.
~280~7
C-81~9 -3-
The catalyst system of the ~nvention uses a
magnesium-containing support for a titanium-containing
cataly~t component. The magnesium support is created by the
reactlon of a magneslum alkoxy alkoxlde wlth titanium
tetrachlorlde.
The magnesium alkoxyalkoxide catalyst components
suitable for use ln the process and formation of catalyst of
- thls invention are described ln U.S. Patent
No. 4,837,190. Suitable magnesium
alkoxides as those represented by the formula:
(z-(cH2)n~)-Mg-(o(cH2)m OR2)
wherein n and m are the same or different positive integers
from 1 to 12; Z is (Rlo)- or (Rl)-; and Rl and R2 are the
~ame or dlfferent hydroearbon radicals eontaining I to 20
carbon atoms. A yreferred ma~ne~ium alkoxide ha8 Rl and R2
alkyl ~roup~ of 1 to 12 earbon atoms, and intoger values of
n and ~ ~aeh lo~ than or egual to 4.
~xemplary ~agnesium alkoxy alkoxldes are as follows:
Ma~nesium bis(2-methoxyethylate)
Magne~ium bi~(2-ethoxyethylate)
Ma~nesium b~s(2-butyoxyethylate)
Magnesium bis(3-methoxypropylate)
Magneslum bi~(3-ethoxypropylate)
Magnesium bis(3-propoxypropylate)
Magnesium bis(3-methoxybutylate)
The alkoxy alkoxides of magne~lum used in the
eatalyst preparation of the invention are prepared by the
direet reaetion of metallie magnesium with one or more
alkoxy alcohol~. A eatalyst such a~ lodine or mereurie
chloride may be u~ed to promote the alkoxlde ~ormlng
reaetion. The defining eharaeter~stie of an alkoxy alkoxide
belng "organie solvent soluble" is defined herein to be a
rA~
~7
C-8179 4
solubility of at least 15 weight percent at ambient (approx.
20C) temperature in toluene or 2-methoxyethanol or 2-
butoxybutanol.
The transition metal polymerization cataly~t
component i8 formed by the reaction of (i) the magnesium
alkoxy alkoxide with, (ii) titanium tetrachloride. The
molar proportions of magnesium alkoxide (i) to titanium
halide (ii) are from 1:5 to 1:1000, with ratios of from l:10
to 1:300 being preferred, Generally, the magnesium and
titanium reactants are combined at above ambient
temperatures, typically, from about 40C to about 150C.
Reaction time is not critical, but often requires several
hours. The product of the first ~tep catalyst component
format$on has the appearance of a dark powder, and typically
contains from 0.5 to 10% titanium.
The firqt step tltanium catalyst product may be
stored under inert condltion~ before comblnation wlth lts
co-catalyst ingrodlent.
A suitable aluminum co-catalyst lngredlent is
~elected from alumlnum alkyls, aluminum halides and/or
alumlnum organo halides. The aluminum component may be
represented by the formula:
( )(3-n)AlXn
wherein R 18 an organo group and X is a halogen selected
from chlorine, bromine, or iodine and n is zero or an
integer from 1 to 2. The mole ratio of titanium tetrahalide
to alumlnum component in the combined catalyst ~ystem is
from about 1:5 to about 1:500. The transition metal
catalyst component and the aluminum co-catalyst component
are comblned slmply by mixing, although the components may
be milled together if desired.
A wide variety of catalyst addition agents, including
activators and electron donors, may be used together with
~2801i7
C-81~9 -5-
the essential magnesium alkoxy alkoxide, titanium
tetrachlorlde, and aluminum catalyst components.
It i8 prefera~le to add the aluminum co-catalyst
component to the titanium component ~ust prior to the use of
the catalyst for polymerization.
Catalyst adjuvants such as electron donors are useful
in increasing the efficiency of the catalyst of the
invention. Typical electron donors are selected from the
group consisting of monocarboxylic acid esters, aliphatic
carboxylic acids, carboxylic acid anhydrides, ketones,
aliphatic ethers and organo silicon compounds. Illustrative
electron donors are phthalic anhydride, diisobutylphthalate,
phenyltriethoxysilane and diphenyldimethoxysilane. In
particular, aromatic polycarboxylic acid esters such as:
monoethyl phthalate, dimethyl phthalate, methylethyl
phthalate, monoisobutyl phthalate, diethyl phthalate, ethyl
isobutylphthalate, di-n-propyl phthalate, diisopropyl
phthalate, dl-n-butyl phthalate, diisobutyl phthalate, di-n-
heptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl
phthalate, dineopentyl phthalate, didecyl phthalate, benzyl
butyl phthalate, diphenyl phthalate, diethyl
naphthalenedicarboxylate and dibutyl
naphthalenedicarboxylate are useful as ad~uvants.
Polymerization of olefins is accomplished by
contacting the olefin with the polymerization catalyst of
the invention in a liquid reaction medium. The liquid
reaction medium is typically selected from liquid propylene,
heptane, hexane, benzene, toluene, or mixtures thereof. The
polymerization conditions are not generally critical, The
polymerizatlon is conducted in liquid phase (solution or
suspension) at temperatures from about 0C to the boiling
point of the liquid phase. Generally, temperatures ln the
range of 15C to 150C are suitable. The pressure may be
subatmospheric, ambient, or superatmospheric. In addition,
hydrogen gas may be used at moderate pressure~ to control
the molecular weight of the reaction products.
C-8179 -6-
The catalyst of the invention is useful for the
polymerization of ethylene, alpha olefins or mixtures
thereof. The polymerization of propylene is particularly
desirable using the cataly~t of the invention.
The practlce of the invention i8 illustrated by but
not limited to the following Example:
~zao~l7
C-8179 -7-
EXAMPLE
_
,Part A - Pre~aration of dit2-butoxYethoxY)maanesium (DBEM)
125 milllliters of 2-butoxyethanol and 250 grams of
heptane were placed in a flask, and brought to reflux.
Magnesium metal (12.9 grams) was added in ~mall ali~uots to
control the vigorous evolution of hydrogen. The mixture was
refluxed for 1 hour after the addition of the final aliquot
of magnesium. The colorless mixture was filtered to remove
a small amount of a black precipitate, yielding 313 grams of
magnesium alkoxide solution.
Part B - Pre~aration of catalYst
29.4 grams of the solution of Part A were used having
a total content of 10.3 grams of DBEM. 35 ml. of decane and
2.1 grams of phthalic anhydride were added to the DBEM
solution, Thl~ solut~on wa~ added dropwlse to 200 ml. of
titanium tetrachlorlde ma~nta~ned at -20C. The dropwise
addition wa~ conducted for 45 minute~ then when complete the
reaction mlxture was heated to 110C over a period of 3
hours. Upon reaching a temperature of 110C, 2.9 grams of
di-isobutylphthalate were added. The mlxture wa~ maintained
at 110C and stirred at 350 rpm for 2.5 hourn. The mixture
was filtered at 110C to yield a solid powder.
The solid resulting from the reaction was mixed with
2~5 ml. of titanium tetrachloride and heated at 110C for 2
hours. Then 200 ml. of toluene were added and the mixture
heated to 110C for 40 minutes. The mixture was filtered at
110C and the solids washed three times with hexane and
vacuum dried. Yield was 6.2 grams of gray-black powder
containing 6.55% titanium.
Part C - Pol~merization of ~ro~Ylene
The catalyst prepared in Part B was tested in a
propylene polymerization test. 150 mg. of catalyst, 10
C-8179 -8-
millimoles of triethyl aluminum, and 0.5 millimoles diphenyl
dimethoxy silane were added to a 4.5 liter autoclave
containing 2 liter~ of hexane. Hydrogen gas at 2 psig.
(13790 pascal) was added, and the reactor pressurized to 100
psig. (689500 pascal) with propylene and maintained at 70C
while stirring at 400 rpm. After 2 hours, the contents were
discharged. The yield was 1360 grams of polypropylene per
gram of catalyst. The polymer had an isotactic index of
94.8%.
