U.S. patent application number 13/610439 was filed with the patent office on 2013-09-19 for two atom bridged dicarbonate compounds as internal donors in catalysts for polypropylene manufacture.
This patent application is currently assigned to Dow Global Technologies LLC. The applicant listed for this patent is Joseph N. Coalter, III, Kuanqiang Gao, Tak W. Leung, Tao Tao. Invention is credited to Joseph N. Coalter, III, Kuanqiang Gao, Tak W. Leung, Tao Tao.
Application Number | 20130245306 13/610439 |
Document ID | / |
Family ID | 43608878 |
Filed Date | 2013-09-19 |
United States Patent
Application |
20130245306 |
Kind Code |
A1 |
Coalter, III; Joseph N. ; et
al. |
September 19, 2013 |
TWO ATOM BRIDGED DICARBONATE COMPOUNDS AS INTERNAL DONORS IN
CATALYSTS FOR POLYPROPYLENE MANUFACTURE
Abstract
A compound suitable for use as an internal electron donor having
a structure: ##STR00001## wherein R.sub.1 is independently at each
occurrence, an aliphatic or aromatic hydrocarbon, or substituted
hydrocarbon group containing from 1 to 20 carbon atoms; R.sub.2 is
independently at each occurrence, a hydrogen atom or aliphatic or
aromatic hydrocarbon, or substituted hydrocarbon group containing
from 1 to 20 carbon atoms; and R3 is an aliphatic hydrocarbyl group
having 1 to 3 carbon atoms.
Inventors: |
Coalter, III; Joseph N.;
(Katy, TX) ; Leung; Tak W.; (Houston, TX) ;
Tao; Tao; (Houston, TX) ; Gao; Kuanqiang;
(Pearland, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Coalter, III; Joseph N.
Leung; Tak W.
Tao; Tao
Gao; Kuanqiang |
Katy
Houston
Houston
Pearland |
TX
TX
TX
TX |
US
US
US
US |
|
|
Assignee: |
Dow Global Technologies LLC
Midland
MI
|
Family ID: |
43608878 |
Appl. No.: |
13/610439 |
Filed: |
September 11, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12956050 |
Nov 30, 2010 |
8263520 |
|
|
13610439 |
|
|
|
|
61265931 |
Dec 2, 2009 |
|
|
|
Current U.S.
Class: |
558/268 |
Current CPC
Class: |
C08F 110/06 20130101;
B01J 31/0201 20130101; Y02P 20/52 20151101; B01J 31/0272 20130101;
C08F 210/06 20130101; B01J 27/138 20130101; B01J 27/135 20130101;
C08F 110/06 20130101; B01J 31/143 20130101; C08F 110/06 20130101;
B01J 31/26 20130101; C08F 4/651 20130101; C07C 69/96 20130101; C08F
210/16 20130101; C08F 4/6465 20130101; C08F 210/06 20130101; C08F
2500/12 20130101; B01J 31/38 20130101 |
Class at
Publication: |
558/268 |
International
Class: |
C07C 69/96 20060101
C07C069/96 |
Claims
1. A compound suitable for use as an internal electron donor having
a structure: ##STR00009## wherein R.sub.1 is independently at each
occurrence, an aliphatic or aromatic hydrocarbon, or substituted
hydrocarbon group containing from 1 to 20 carbon atoms; R.sub.2 is
independently at each occurrence, a hydrogen atom or aliphatic or
aromatic hydrocarbon, or substituted hydrocarbon group containing
from 1 to 20 carbon atoms; and R3 is an aliphatic hydrocarbyl group
having 1 to 3 carbon atoms.
2. The compound of claim 1 wherein R1 is independently at each
occurrence, an aliphatic or aromatic hydrocarbon group containing
from 1 to 6 carbon atoms; and R2 is independently at each
occurrence, a hydrogen atom or aliphatic or aromatic hydrocarbon
group containing from 1 to 6 carbon atoms; and R3 is an aliphatic
hydrocarbyl group having 1 to 3 carbon atoms.
3. The compound of claim 1 wherein R1 is independently at each
occurrence, a methyl, ethyl, isopropyl, t-butyl, or phenyl group;
and R2 is independently at each occurrence, a hydrogen atom or a
methyl, ethyl, or isopropyl group; and R3 is a methyl, ethyl, or
isopropyl group.
4. The compound of claim 1 wherein R1 is independently at each
occurrence, an ethyl, isopropyl, t-butyl, or phenyl group; and R2
is independently at each occurrence, a hydrogen atom; and R3 is a
methyl or isopropyl group.
Description
[0001] This application is a non-provisional application claiming
priority from the U.S. Provisional Patent Application No.
61/265,931, filed on Dec. 2, 2009, and also from the U.S. National
Utility application Ser. No. 12/956,050, filed on Nov. 30, 2010,
entitled "TWO ATOM BRIDGED DICARBONATE COMPOUNDS AS INTERNAL DONORS
IN CATALYSTS FOR POLYPROPYLENE MANUFACTURE," the teachings of which
are incorporated by reference herein, as if reproduced in full
hereinbelow.
[0002] This invention relates to components useful in propylene
polymerization catalysts, and particularly relates to electron
donor components used in combination with magnesium-containing
supported titanium-containing catalyst components.
BACKGROUND AND SUMMARY OF THE INVENTION
[0003] Use of solid, transition metal-based, olefin polymerization
catalyst components is well known in the art including such solid
components supported on a metal oxide, halide or other salt such as
widely-described magnesium-containing, titanium halide-based
catalyst components. Such catalyst components are commonly referred
to as "supported". Although many polymerization and
copolymerization processes and catalyst systems have been described
for polymerizing or copolymerizing alpha-olefins, it is
advantageous to tailor a process and catalyst system to obtain a
specific set of properties of a resulting polymer or copolymer
product. For example, in certain applications, a combination of
acceptably high activity, good morphology, desired particle size
distribution, acceptable bulk density, and the like are required
together with polymer characteristics such as stereospecificity,
molecular weight distribution, and the like.
[0004] Typically, supported catalyst components useful for
polymerizing propylene and higher alpha-olefins, as well as for
polymerizing propylene and higher olefins with minor amounts of
ethylene and other alpha-olefins contain an internal electron donor
component. Such internal electron donor is an integral part of the
solid supported catalyst component and is distinguished from an
external electron donor component, which together with an aluminum
alkyl component, typically comprises the catalyst system. While the
internal electron donor is an integral part of the solid supported
component, the external electron donor may be combined with the
solid supported component shortly before the combination is
contacted with an olefin monomer or in the presence of olefin
monomer. The external electron donor is commonly referred to as a
selectivity control agent (or "SCA"), and the supported catalyst
component is commonly referred to as a procatalyst.
[0005] Selection of the internal electron donor can affect catalyst
performance and the resulting polymer formed from a catalyst
system. Generally, organic electron donors have been described as
useful in preparation of the stereospecific supported catalyst
components including organic compounds containing oxygen, nitrogen,
sulfur, and/or phosphorus. Such compounds include organic acids,
organic acid anhydrides, organic acid esters, alcohols, ethers,
aldehydes, ketones, amines, amine oxides, amides, thiols, various
phosphorus acid esters and amides, and the like. Mixtures of
organic electron donors have been described as useful when
incorporated into supported catalyst components. Examples of
organic electron donors include dicarboxy esters such as alkyl
phthalate and succinate esters.
[0006] In current practice, alkyl phthalate esters are commonly
used as internal electron donors in commercial propylene
polymerization catalyst systems. However, certain environmental
questions have been raised concerning continued use of phthalate
derivatives in applications where human contact is anticipated.
[0007] Particular uses of propylene polymers depend upon the
physical properties of the polymer, such as molecular weight,
viscosity, stiffness, flexural modulus, and polydispersity index
(molecular weight distribution (Mw/Mn)). In addition, polymer or
copolymer morphology often is critical and typically depends upon
catalyst morphology. Good polymer morphology generally involves
uniformity of particle size and shape, resistance to attrition and
an acceptably high bulk density. Minimization of very small
particles (fines) typically is important especially in gas-phase
polymerizations or copolymerizations in order to avoid transfer or
recycle line pluggage.
[0008] The art presently recognizes a finite set of compounds
suitable for use as internal electron donors in supported catalyst
components. With the continued diversification and sophistication
of applications for olefin-based polymers, the art recognizes the
need for olefin-based polymers with improved and varied properties.
Desirable would be internal electron donors in supported catalyst
components that contribute to strong catalyst activity and high
hydrogen response during polymerization. Further desired are
internal electron donors in supported catalyst components that
produce propylene-based polymers with high isotacticity, commonly
expressed as a xylenes soluble fraction (XS) and/or final melting
temperatue (TMF).
[0009] The invention described relates to use of an internal
modifier (internal electron donor) in a propylene polymerization
catalyst component, which contains at least two carbonate
functionalities.
[0010] Accordingly, one embodiment of the invention is a solid,
hydrocarbon-insoluble, catalyst component useful in polymerizing
olefins, said catalyst component containing magnesium, titanium,
and halogen, and further containing an internal electron donor
comprising a compound having a structure:
[R.sub.1--O--C(O)--O--].sub.xR.sub.2
wherein R.sub.1 is independently at each occurrence, an aliphatic
or aromatic hydrocarbon, or substituted hydrocarbon group
containing from 1 to 20 carbon atoms; x is 2-4; and R.sub.2 is an
aliphatic or aromatic hydrocarbon, or substituted hydrocarbon group
containing from 1 to 20 carbon atoms, provided that there are 2
atoms in the shortest chain connecting a first
R.sub.1--O--C(O)--O-- group and a second R.sub.1--O--C(O)--O--
group.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0011] All references to the Periodic Table of the Elements herein
shall refer to the Periodic Table of the Elements, published and
copyrighted by CRC Press, Inc., 2003. Also, any references to a
Group or Groups shall be to the Groups or Groups reflected in this
Periodic Table of the Elements using the IUPAC system for numbering
groups. Unless stated to the contrary, implicit from the context,
or customary in the art, all parts and percents are based on
weight. For purposes of United States patent practice, the contents
of any patent, patent application, or publication referenced herein
are hereby incorporated by reference in their entirety (or the
equivalent US version thereof is so incorporated by reference),
especially with respect to the disclosure of synthetic techniques,
definitions (to the extent not inconsistent with any definitions
provided herein) and general knowledge in the art.
[0012] The term "comprising," and derivatives thereof, is not
intended to exclude the presence of any additional component, step
or procedure, whether or not the same is disclosed herein. In order
to avoid any doubt, all compositions claimed herein through use of
the term "comprising" may include any additional additive,
adjuvant, or compound whether polymeric or otherwise, unless stated
to the contrary. In contrast, the term, "consisting essentially of"
excludes from the scope of any succeeding recitation any other
component, step or procedure, excepting those that are not
essential to operability. The term "consisting of" excludes any
component, step or procedure not specifically delineated or listed.
The term "or", unless stated otherwise, refers to the listed
members individually as well as in any combination.
[0013] Any numerical range recited herein, includes all values from
the lower value to the upper value, in increments of one unit,
provided that there is a separation of at least 2 units between any
lower value and any higher value. As an example, if it is stated
that the amount of a component, or a value of a compositional or a
physical property, such as, for example, amount of a blend
component, softening temperature, melt index, etc., is between 1
and 100, it is intended that all individual values, such as, 1, 2,
3, etc., and all subranges, such as, 1 to 20, 55 to 70, 197 to 100,
etc., are expressly enumerated in this specification. For values
which are less than one, one unit is considered to be 0.0001,
0.001, 0.01 or 0.1, as appropriate. These are only examples of what
is specifically intended, and all possible combinations of
numerical values between the lowest value and the highest value
enumerated, are to be considered to be expressly stated in this
application. In other words, any numerical range recited herein
includes any value or subrange within the stated range. Numerical
ranges have been recited, as discussed herein, reference melt
index, melt flow rate, and other properties.
[0014] The term "composition," as used herein, includes a mixture
of materials which comprise the composition, as well as reaction
products and decomposition products formed from the materials of
the composition.
[0015] The terms "blend" or "polymer blend," as used herein, is a
blend of two or more polymers. Such a blend may or may not be
miscible (not phase separated at molecular level). Such a blend may
or may not be phase separated. Such a blend may or may not contain
one or more domain configurations, as determined from transmission
electron spectroscopy, light scattering, x-ray scattering, and
other methods known in the art.
[0016] The term "polymer" is a macromolecular compound prepared by
polymerizing monomers of the same or different type. "Polymer"
includes homopolymers, copolymers, terpolymers, interpolymers, and
so on. The term "interpolymer" means a polymer prepared by the
polymerization of at least two types of monomers or comonomers. It
includes, but is not limited to, copolymers (which usually refers
to polymers prepared from two different types of monomers or
comonomers, terpolymers, tetrapolymers, and the like.
[0017] The term "interpolymer," as used herein, refers to polymers
prepared by the polymerization of at least two different types of
monomers. The generic term interpolymer thus includes copolymers,
usually employed to refer to polymers prepared from two different
monomers, and polymers prepared from more than two different types
of monomers.
[0018] The term "olefin-based polymer" is a polymer containing, in
polymerized form, a majority weight percent of an olefin, for
example ethylene or propylene, based on the total weight of the
polymer. Nonlimiting examples of olefin-based polymers include
ethylene-based polymers and propylene-based polymers.
[0019] The term, "ethylene-based polymer," as used herein, refers
to a polymer that comprises a majority weight percent polymerized
ethylene monomer (based on the total weight of polymerizable
monomers), and optionally may comprise at least one polymerized
comonomer.
[0020] The term, "propylene-based polymer," as used herein, refers
to a polymer that comprises a majority weight percent polymerized
propylene monomer (based on the total amount of polymerizable
monomers), and optionally may comprise at least one polymerized
comonomer.
[0021] As used herein, the term "hydrocarbyl" and "hydrocarbon"
refer to substituents containing only hydrogen and carbon atoms,
including branched or unbranched, saturated or unsaturated, cyclic,
polycyclic, fused, or acyclic species, and combinations thereof.
Nonlimiting examples of hydrocarbyl groups include alkyl-,
cycloalkyl-, alkenyl-, alkadienyl-, cycloalkenyl-,
cycloalkadienyl-, aryl-, aralkyl, alkylaryl, and alkynyl- groups.
As used herein, the terms "substituted hydrocarbyl" and
"substituted hydrocarbon" refer to a hydrocarbyl group that is
substituted with one or more nonhydrocarbyl substituent groups. A
nonlimiting example of a nonhydrocarbyl substituent group is a
heteroatom. As used herein, a "heteroatom" refers to an atom other
than carbon or hydrogen. The heteroatom can be a non-carbon atom
from Groups IV, V, VI, and VII of the Periodic Table. Nonlimiting
examples of heteroatoms include: halogens (F Cl, Br, I), N, O, P,
B, S, and Si. A substituted hydrocarbyl group also includes a
halohydrocarbyl group and a silicon-containing hydrocarbyl group.
As used herein, the term "halohydrocarbyl" group refers to a
hydrocarbyl group that is substituted with one or more halogen
atoms.
[0022] The term "alkyl," as used herein, refers to a branched or
unbranched, saturated or unsaturated acyclic hydrocarbon radical.
Nonlimiting examples of suitable alkyl radicals include, for
example, methyl, ethyl, n-propyl, i-propyl, 2-propenyl (or allyl),
vinyl, n-butyl, t-butyl, i-butyl (or 2-methylpropyl), etc. The
alkyls have 1 to 20 carbon atoms.
[0023] The term "substituted alkyl," as used herein, refers to an
alkyl as just described in which one or more hydrogen atom bound to
any carbon of the alkyl is replaced by another group such as a
halogen, aryl, substituted aryl, cycloalkyl, substituted
cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl,
halogen, haloalkyl, hydroxy, amino, phosphido, alkoxy, amino, thio,
nitro, other heteroatom containing groups, and combinations
thereof. Suitable substituted alkyls include, for example, benzyl,
trifluoromethyl and the like.
[0024] The term "aryl," as used herein, refers to an aromatic
substituent which may be a single aromatic ring or multiple
aromatic rings which are fused together, linked covalently, or
linked to a common group such as a methylene or ethylene moiety.
The aromatic ring(s) may include phenyl, naphthyl, anthracenyl, and
biphenyl, among others. The aryls have 6 to 20 carbon atoms.
[0025] The term "carbonate" as used herein, refers to a functional
group within a larger molecule that contains a carbon atom bound to
three oxygen atoms, one of which is double bonded. Such compounds
are also known as organocarbonates or carbonate esters.
[0026] The supported catalyst components of this invention contain
at least one internal electron donor comprising electron donating
substituents comprising a dicarbonate. Dicarbonates are defined as
those compounds corresponding to the following structure:
[R.sub.1--O--C(O)--O--].sub.xR.sub.2
wherein R.sub.1 is independently at each occurrence, an aliphatic
or aromatic hydrocarbon, or substituted hydrocarbon group
containing from 1 to 20 carbon atoms; x is 2-4; and R.sub.2 is an
aliphatic or aromatic hydrocarbon, or substituted hydrocarbon group
containing from 1 to 20 carbon atoms, provided that there are 2
atoms in the shortest chain connecting a first
R.sub.1--O--C(O)--O-- group and a second R.sub.1--O--C(O)--O--
group.
[0027] It is preferred that x be equal to 2, and as a result, in
the broadest sense of the invention the term "dicarbonate" is used
to generically describe these compounds even though compounds with
3 or even 4 carbonate groups are contemplated.
[0028] For many applications it is preferred that the R.sub.1 group
be an aliphatic or aromatic hydrocarbon group. It is also preferred
that such aliphatic group be of relatively shorter length, for
example from 1-6 carbon atoms, and such aromatic group be
relatively compact, for example having from 6-10 carbon atoms
[0029] The R.sub.2 groups in the dicarbonates useful in the present
invention are such that there are 2 atoms in the shortest chain
between 2 carbonate groups. Preferably, these linking atoms are
carbon atoms but heteroatoms such as oxygen, nitrogen, silicon, or
phosphorous may also be used. It should be understood that the 2
linking atoms refers only to the atoms in the shortest chain
between the carbonate groups and that the R.sub.2 groups are
typically much larger, as they contain atoms which do not directly
link the carbonate groups. Preferred R.sub.2 groups include phenyls
where the linking atoms are adjacent on the ring, and naphthalenes,
where the linking atoms are adjacent on one of the fused rings.
Such phenyls or naphthalenes may advantageously contain alkyl
groups or other substituents.
[0030] The hydrocarbons useful in the present invention may be
substituted with atoms other than carbon or hydrogen. For example,
alkyl groups used in this invention may be substituted with
compatible groups containing heteroatoms including nitrogen,
oxygen, phosphorus, silicon, and halogens. Thus, a hydrocarbon
group used in this invention may be substituted with an ether,
amine, amide, chloro, bromo, or silyl group, for example.
Similarly, cyclic structures which may be incorporated into the
donor compounds as part of either the R.sub.1 or R.sub.2 groups may
contain hetero atoms, such as nitrogen, oxygen, silicon, and
phosphorus.
[0031] Non-limiting examples of some specific dicarbonates for use
in the present invention include the following, and their
substituted derivatives
##STR00002## ##STR00003##
[0032] The dicarbonate materials suitable for use as internal
electron donors in the present invention can be made according to
methods known in the art. One suitable method for making a true
dicarbonate (that is, where x=2) involves reacting a diol with at
least two molar equivalents of a substituted cholorformate. Thus
the reaction could be described as:
R.sub.2(OH).sub.2+2Cl--C(O)--OR.sub.1.fwdarw.[R.sub.1--O--C(O)--O--].sub-
.2R.sub.2
where R.sub.1 and R.sub.2 are as described above. A suitable base
may be present to sequester the hydrochloric acid liberated during
the reaction. A suitable variation of this method is to first react
the diol with a suitable base to effect partial or complete
deprotonation, followed by treatment with at least 2 molar
equivalents of a substituted cholorformate.
[0033] The dicarbonates of the present invention are useful as
internal electron donors in high activity supported
titanium-containing Ziegler-Natta catalysts commonly used in the
manufacture of polypropylene.
[0034] Supported titanium-containing components useful in this
invention generally are supported on hydrocarbon-insoluble,
magnesium-containing compounds in combination with an electron
donor compound. Such supported titanium-containing olefin
polymerization catalyst component typically is formed by reacting a
titanium (IV) halide, an organic electron donor compound and a
magnesium-containing compound. Optionally, such supported
titanium-containing reaction product may be further treated or
modified by further chemical treatment with additional electron
donor or Lewis acid species. The resulting supported
titanium-containing components are also referred to as "supported
catalyst components" or "procatalysts."
[0035] Suitable magnesium-containing compounds include magnesium
halides; a reaction product of a magnesium halide such as magnesium
chloride or magnesium bromide with an organic compound, such as an
alcohol or an organic acid ester, or with an organometallic
compound of metals of Groups I-III; magnesium alcoholates; mixed
magnesium/titanium halide alcoholates; or magnesium alkyls.
[0036] Examples of supported catalyst components are prepared by
reacting a magnesium chloride, alkoxy magnesium chloride or aryloxy
magnesium chloride, or mixed magnesium/titanium halide alcoholate
with a titanium halide, such as titanium tetrachloride, and further
incorporation of an electron donor compound. In a preferable
preparation, the magnesium-containing compound is dissolved, or is
in a slurry, in a compatible liquid medium, such as a hydrocarbon
or halogenated hydrocarbon to produce suitable catalyst component
particles.
[0037] The possible supported solid catalyst components listed
above are only illustrative of many possible solid,
magnesium-containing, titanium halide-based, hydrocarbon-insoluble
catalyst components useful in this invention and known to the art.
This invention is not limited to a specific supported catalyst
component.
[0038] Supported catalyst components known to the art may be used
with the internal donors described in this invention. Typically,
the internal electron donor material of this invention is
incorporated into a solid, supported catalyst component during
formation of such component. Typically, such electron donor
material is added with, or in a separate step, during treatment of
a solid magnesium-containing material with a suitable titanium
source, such as a titanium (IV) compound. Such magnesium-containing
material typically is in the form of discrete particles and may
contain other materials such as transition metals and organic
compounds. Also, a mixture of magnesium chloride, titanium
tetrachloride and the internal donor may be formed into a supported
catalyst component by ball-milling.
Magnesium Source
[0039] The magnesium source is preferably in the form of a
supported catalyst component precursor prepared in accordance with
any of the procedures described in, for example, U.S. Pat. Nos.
4,540,679; 4,612,299; 4,866,022; 4,946,816; 5,034,361; 5,066,737;
5,082,907; 5,106,806; 5,146,028; 5,151,399; 5,229,342 and
7,491,781, the disclosures of which are incorporated by reference
herein in their entirety. The magnesium source may also be a
magnesium halide, alkyl, aryl, alkaryl, alkoxide, alkaryloxide or
aryloxide, alcohol aducts thereof, carbonated derivatives thereof,
or sulfonated derivatives thereof, but preferably is an alcohol
adduct of a magnesium halide, a magnesium dialkoxide, a carbonated
magnesium dialkoxide, a carbonated magnesium diaryloxide, or a
mixed magnesium/titanium halide alcoholate. Magnesium compounds
containing one alkoxide and one aryloxide group can also be
employed, as well as magnesium compounds containing a halogen in
addition to one alkoxide, alkaryloxide, or aryloxide group. The
alkoxide groups, when present, most suitable contain from 1 to 8
carbons, preferably from 2 to 6 carbon atoms. The aryloxide groups,
when present, most suitable contain from 6 to 10 carbons. When a
halogen is present, it is preferably chlorine.
[0040] Among the magnesium dialkoxides and diaryloxides which can
be employed are those of the formula
Mg(OC(O)OR.sup.3).sub.a(OR.sup.4).sub.2-a wherein R.sup.3 and
R.sup.4 are alkyl, alkaryl, or aryl groups, and a is about 0.1 to
about 2. The most preferable magnesium compound contaning a
carbonate group is carbonated magnesium diethoxide (CMEO),
Mg(OC(O)OEt).sub.2. Optionally the magnesium may be halogenated
with an additional halogenating agent, e.g., thionyl chloride or
alkylchlorosilanes, prior to contact with the tetravalent titanium
source.
[0041] A somewhat different type of magnesium source is described
by the general formula Mg.sub.4(OR.sup.5).sub.6(R.sup.6OH).sub.10A
in which each R.sup.5 or R.sup.6 is a lower alkyl of up to 4 carbon
atoms inclusive and A is one or more anions having a total charge
of -2. The manufacturing of this magnesium source is disclosed in
U.S. Pat. No. 4,710,482 to Job which is incorporated herein by
reference.
[0042] Another particularly preferred magnesium source is one that
contains moieties magnesium and titanium and probably moieties of
at least some of halide, alkoxide, and a phenolic compound. Such
complex procatalyst precursors are produced by contacting a
magnesium alkoxide, a titanium alkoxide, a titanium halide, a
phenolic compound, and an alkanol. See U.S. Pat. No. 5,077,357 to
Job which is incorporated herein by reference.
[0043] A further useful magnesium source is a mixed
magnesium/titanium compound ("MagTi"). The "MagTi precursor" has
the formula Mg.sub.bTi(OR.sup.7).sub.cX.sup.1.sub.d wherein R.sup.7
is an aliphatic or aromatic hydrocarbon radical having 1 to 14
carbon atoms or COR.sup.8 wherein R.sup.8 is an aliphatic or
aromatic hydrocarbon radical having 1 to 14 carbon atoms; each
OR.sup.7 group is the same or different; X.sup.1 is independently
chlorine, bromine or iodine, preferably chlorine; b is 0.5 to 56,
or 2 to 4; c is 2 to 116 or 5 to 15; and d is 0.5 to 116, or 1 to
3. These precursors are prepared by controlled precipitation
through removal of an alcohol from the reaction mixture used in
their preparation. As such, a reaction medium comprises a mixture
of an aromatic liquid, especially a chlorinated aromatic compound,
most especially chlorobenzene, with an alkanol, especially ethanol.
Suitable halogenating agents include titanium tetrabromide,
titanium tetrachloride or titanium trichloride, especially titanium
tetrachloride. Removal of the alkanol from the solution used in the
halogenation, results in precipitation of the solid precursor,
having especially desirable morphology and surface area. Moreover,
the resulting precursors are particularly uniform in particle
size.
[0044] An additional useful magnesium source is a
benzoate-containing magnesium chloride material ("BenMag"). As used
herein, a "benzoate-containing magnesium chloride" ("BenMag") can
be a supported catalyst component (i.e., a halogenated supported
catalyst component precursor) which contains a benzoate internal
electron donor. The BenMag material may also include a titanium
moiety, such as a titanium halide. The benzoate internal donor is
labile and can be replaced by other electron donors during the
supported catalyst component and/or catalyst synthesis. Nonlimiting
examples of suitable benzoate groups include ethyl benzoate, methyl
benzoate, ethyl p-methoxybenzoate, methyl p-ethoxybenzoate, ethyl
p-ethoxybenzoate, ethyl p-chlorobenzoate. A preferred benzoate
group is ethyl benzoate. Nonlimiting examples of suitable BenMag
procatalyst precursors include catalysts of the trade names
SHAC.TM. 103 and SHAC.TM. 310 available from The Dow Chemical
Company, Midland, Mich. The BenMag supported catalyst component
precursor may be a product of halogenation of a supported catalyst
component precursor (e.g., a magnesium dialkoxide, a carbonated
magnesium dialkoxide, or a MagTi precursor) in the presence of a
benzoate compound.
Titanium Source
[0045] The titanium source for the supported catalyst component
preferably is a tetravalent titanium which contains at least two
halogen atoms, and preferably contains four halogen atoms, e.g.,
Ti(OR.sup.91).sub.cX.sup.2.sub.4-e, wherein R.sup.9 is a
hydrocarbon, and X.sup.2 is a halide and e is 0 to 2. Most
preferably these halogen atoms are chlorine atoms. Titanium
compounds containing up to two alkoxy, alkaryloxy or aryloxy groups
can be employed. The alkoxy groups, when present, most suitably
contain from 1 to 8 carbon atoms, preferably 2 to 6 carbon atoms.
The aryloxy or alkaryloxy groups, when present, most suitably
contain from 6 to 12 carbon atoms, preferably from 6 to 10 carbon
atoms. Examples of suitable alkoxy- and aryloxy-titanium halides
include diethoxy titanium dibromide, isopropoxy titanium triiodide,
dihexoxy titanium dichloride, and phenoxy titanium trichloride. The
most preferable titanium source is TiCl.sub.4.
Supported Catalyst Component Manufacture
[0046] The magnesium compound preferably is reacted (i.e.,
halogenated) with the tetravalent titanium halide in the presence
of an internal electron donor and optionally a halohydrocarbon.
Optionally, an inert hydrocarbon diluent or solvent also may be
present. Various methods for preparing supported catalyst
components are known in the art. Some of these methods are
described in, for example, U.S. Pat. Nos. 4,442,276; 4,460,701;
4,547,476; 4,816,433; 4,829,037; 4,927,797; 4,990,479; 5,066,738;
5,028,671; 5,153,158; 5,247,031 and 5,247,032. Regardless of the
method of formation, the supported catalyst components of this
invention include the internal electron donor material described in
this invention.
[0047] When optionally employed, the halohydrocarbon used may be
aromatic, aliphatic, or alicyclic. Most preferably, the halogen of
the halohydrocarbon is chlorine. Aromatic halohydrocarbons are
preferred, particularly those containing from 6 to 12 carbon atoms,
preferably 6 to 10 carbon atoms. Preferably such halohydrocarbons
contain 1 or 2 halogen atoms, although more may be present if
desired. Suitable aromatic halohydrocarbons include, but are not
limited to chlorobenzene, bromobenzene, dichlorobenzene,
dichlorodibromobenzene, chlorotoluene, dichlorotoluene, and
chloronaphthalene. The aliphatic halohydrocarbons contain from 1 to
12 carbon atoms, preferably from 1 to 9 carbon atoms and at least 2
halogen atoms. Suitable aliphatic halohydrocarbons include, but are
not limited to dibromomethane, trichloromethane,
1,2-dichloroethane, trichloroethane, dichlorofluoroethane,
hexachloroethane, trichloropropane, chlorobutane, dichlorobutane,
chloropentane, trichlorofluorooctane, tetrachloroisooctane,
dibromodifluorodecane, carbon tetrachloride, and trichloroethane.
The alicyclic halohydrocarbons which can be employed contain from 3
to 12 carbon atoms, and preferably from 3 to 9 carbon atoms, and at
least 2 halogen atoms. Suitable alicyclic halohydrocarbons include
dibromocyclobutane, and trichlorocyclohexane.
[0048] The optional inert hydrocarbon diluent may be aliphatic,
aromatic or alicyclic. Some exemplary diluents are isopentane,
n-octane, isooctane, xylene, or toluene.
[0049] Halogenation of the magnesium compound with the halogenated
tetravalent titanium halide is effected employing an excess of the
titanium halide. At least 2 moles of the titanium halide should be
employed per mole of the magnesium compound. Preferably from about
4 moles to about 100 moles of the titanium halide are employed per
mole of the magnesium compound, and most preferably from about 4
moles to about 20 moles of the titanium halide are employed per
mole of the magnesium compound.
[0050] When optionally employed, the halohydrocarbon is used in an
amount sufficient to dissolve the titanium halide and the internal
electron donor, and to adequately disperse the magnesium compound.
Usually the dispersion contains from about 0.005 to about 2.0 moles
of the solid magnesium compound per mole of halohydrocarbon,
preferably from about 0.01 to about 1.0 mole of the solid magnesium
compound per mole of the halohydrocarbon. The internal electron
donor is employed in an amount sufficient to provide a molar ratio
of said compound to the titanium halide of from about 0.0005:1 to
about 2.0:1, preferably from about 0.001:1 to about 0.1:1. About
1:100 to 100:1 by volume of halohydrocarbon to optional diluent may
be used.
[0051] Halogenation can be effected at a temperature up to about
150.degree. C., preferably from about 80.degree. C. to about
140.degree. C. Usually the reaction is allowed to proceed over a
period of 0.1 to 6 hours, preferably between about 0.5 to about 3.5
hours. For convenience, halogenation is usually effected at
atmospheric pressure, although a range of pressures can be
employed, e.g., 0.5 atm (50,700 Pa) to 5 atm (507,000 Pa). The
halogenated product, like the starting magnesium compound, is a
solid material which can be isolated from the liquid reaction
medium by drying, filtration, decantation, evaporation,
distillation or any suitable method.
[0052] After separation, the halogenated product (also termed the
supported catalyst component upon halogenation) may be treated one
or more times with additional tetravalent titanium halide to remove
residual alkoxy and/or aryloxy groups and maximize catalyst
activity or other desired properties. Preferably, the halogenated
product is treated at least twice with separate portions of the
tetravalent titanium halide. Generally, the reaction conditions
employed to treat the halogenated product with the titanium halide
are the same or similar to those employed during the initial
halogenation of the magnesium compound, and the internal electron
donor may or may not be present during the treatment(s). When
optionally employed, the halohydrocarbon is typically used to
dissolve the titanium halide and disperse the solid, halogenated
product. If desired, the halogenated product may be treated with
the acid halide before or after it is treated with the titanium
compound for the second time. From 5 mmol to 200 mmol of the acid
halide generally are employed per mole of magnesium in the
halogenated product (i.e. supported catalyst component). Suitable
acid halides include benzoyl chloride, phthaloyl dichloride,
2,3-naphthalenedicarboxylic acid dichloride,
endo-5-norbornene-2,3-dicarboxylic acid dichloride, maleic acid
dichloride, citraconic acid dichloride, and the like. A useful
procedure for treatment of the halogentated product by acid halides
is described in U.S. Pat. No. 6,825,146.
[0053] After the supported catalyst component has been treated one
or more times with additional tetravalent titanium halide, it is
separated from the liquid reaction medium, and preferably washed
with an inert hydrocarbon such as isopentane, isooctane, isohexane,
hexane, pentane, heptane, or octane to remove unreacted titanium
compounds or other imporities. The supported catalyst component can
then be dried, or it may slurried in a hydrocarbon, especially a
relatively heavy hydrocarbon such as mineral oil for further
storage or use. If dried, the drying process may be by filtration,
evaporation, heating or other methods known in the art.
[0054] Not wishing to be bound by any particular theory, it is
believed that (1) further halogenation by contacting the previously
formed supported catalyst component with a titanium halide
compound, especially a solution thereof in a halohydrocarbon
diluent, and/or (2) further washing the previously formed supported
catalyst component with a halohydrocarbon at an elevated
temperature (100.degree. C. to 150.degree. C.), results in
desirable modification of the supported catalyst component,
possibly by removal of certain inactive metal compounds that are
soluble in the foregoing diluent. Accordingly, the supported
catalyst component may be contacted with a halogenating agent, such
as a mixture of a titanium halide and a halohydrocarbon diluent,
such as TiCl.sub.4 and chlorobenzene, one or more times prior to
isolation or recovery. Correspondingly, the supported catalyst
component may be washed at a temperature between 100.degree. C. to
150.degree. C. with a halohydrocarbon such as chlorobenzene or
o-chlorotoluene one or more times prior to isolation or
recovery.
[0055] The final supported catalyst component product suitably has
a titanium content of from about 0.5 percent by weight to about 6.0
percent by weight, or from about 1.0 percent by weight to about 5.0
percent by weight. The weight ratio of titanium to magnesium in the
solid supported catalyst component is suitably between about 1:3
and about 1:160, or between about 1:4 and about 1:50, or between
about 1:6 and 1:30. The internal electron donor is present in the
supported catalyst component in a molar ratio of internal electron
donor to magnesium of from about 0.001:1 to about 10.0:1, or from
about 0.01:1 to about 0.4:1. Weight percent is based on the total
weight of the supported catalyst composition.
[0056] The internal electron donor material useful in this
invention may be combined with additional internal electron donors
such as ethers, esters, amines, imines, nitriles, phosphines,
stibines, arsines, polyhydrocarbyl phosphonates, phosphinates,
dialkylphthalates, phosphates or phosphine oxides, or alkyl
aralkylphthalates, wherein the alkyl moiety contains from 1 to 10,
preferably 2 to 6, carbon atoms and the aralkyl moiety contains
from 7 to 10, preferably to 7 to 8, carbon atoms, or an alkyl ester
of an aromatic monocarboxylic acid wherein the monocarboxylic acid
moiety contains from 6 to 10 carbon atoms and the alkyl moiety
contains from 1 to 6 carbon atoms. Such combination or
incorporation of additional internal electron donors may occur in
any of the steps employing the titanium compound.
[0057] Prepolymerization or encapsulation of the catalyst or
supported catalyst component of this invention also may be carried
out prior to being used in the polymerization or copolymerization
of alpha olefins. A particularly useful prepolymerization procedure
is described in U.S. Pat. No. 4,579,836, which is incorporated
herein by reference.
Catalyst
[0058] The olefin polymerization catalyst (or "catalyst
composition") includes the above-described supported catalyst
component, a cocatalyst, and optionally a selectivity control agent
(also know as an "SCA", "external donor", or "external electron
donor"), and optionally an activity limiting agent (or "ALA").
Cocatalyst
[0059] The cocatalyst may be chosen from any of the known
activators of olefin polymerization catalyst systems, but
organoaluminum compounds are preferred. Such cocatalysts can be
employed individually or in combinations thereof. Suitable
organoaluminum cocatalysts have the formula
Al(R.sup.10).sub.fX.sup.3.sub.gH.sub.h wherein: X.sup.3 is F, Cl,
Br, I, or OR.sup.10, and R.sup.10 are saturated hydrocarbon
radicals containing from 1 to 14 carbon atoms, which radicals may
be the same or different, and, if desired, substituted with any
substituent which is inert under the reaction conditions employed
during polymerization, f is 1 to 3, g is 0 to 2, h is 0 or 1, and
f+g+h=3. Trialkylaluminum compounds are particularly preferred,
particularly those wherein each of the alkyl groups contains from 1
to 6 carbon atoms, e.g., Al(CH.sub.3).sub.3,
Al(C.sub.2H.sub.5).sub.3, Al(i-C.sub.4H.sub.9).sub.3, and
Al(C.sub.6H.sub.13).sub.3.
SCA Bounded by no particular theory, it is believed that provision
of one or more SCA (selectivity control agent) in the catalyst
composition can affect the following properties of the formant
polymer: level of tacticity (i.e., xylene soluble material),
molecular weight (i.e., melt flow), molecular weight distribution
(MWD), melting point, and/or oligomer level. The SCA, also known as
external donor or external electron donor, used in the invention is
typically one of those known in the art. The SCAs known in the art
include, but are not limited to, silicon compounds, esters of
carboxylic acids, (especially diesters), monoethers, diethers
(e.g., 1,3-dimethoxy propane or 2,2-diisobutyl-1,3 dimethoxy
propane), and amines (e.g., tetramethylpiperidine).
[0060] Preferably, the silicon compounds employed as SCAs contain
at least one silicon-oxygen-carbon linkage. Suitable silicon
compounds include those having the formula
R.sup.11.sub.iSiY.sub.jX.sup.4.sub.k wherein: R.sup.11 is a
hydrocarbon radical containing from 1 to 20 carbon atoms, Y is
--OR.sup.12 or --OCOR.sup.12 wherein R.sup.12 is a hydrocarbon
radical containing from 1 to 20 carbon atoms, X.sup.4 is hydrogen
or halogen, i is an integer having a value of from 0 to 3, j is an
integer having a value of from 1 to 4, k is an integer having a
value of from 0 to 1, and preferably 0, and i+j+k=4. Preferably,
R.sup.11 and R.sup.12 are alkyl, aryl or alkaryl ligands of
C.sub.1-C.sub.10. Each R.sup.11 and R.sup.12 may be the same or
different, and, if desired, substituted with any substituent which
is inert under the reaction conditions employed during
polymerization. Preferably, R.sup.12 contains from 1 to 10 carbon
atoms when it is aliphatic and may be sterically hindered or
cycloaliphatic, and from 6 to 10 carbon atoms when it is
aromatic.
[0061] Examples of R.sup.11 include cyclopentyl, t-butyl,
isopropyl, cyclohexyl or methyl cyclohexyl. Examples of R.sup.12
include methyl, ethyl, butyl, isopropyl, phenyl, benzyl and
t-butyl. Examples of X.sup.4 are Cl and H. Preferred silicon SCAs
are alkylalkoxysilanes such as diethyldiethoxysilane, diphenyl
dimethoxy silane, diisobutyldimethoxysilane,
cyclohexylmethyldimethoxysilane, n-propyltrimethoxysilane, or
dicyclopentyldimethoxysilane.
[0062] Silicon compounds in which two or more silicon atoms are
linked to each other by an oxygen atom, i.e., siloxanes or
polysiloxanes, may also be employed, provided the requisite
silicon-oxygen-carbon linkage is also present. Other preferred SCAs
are esters of aromatic monocarboxylic or dicarboxylic acids,
particularly alkyl esters, such as PEEB, DIBP, and methyl
paratoluate.
[0063] The SCA is provided in a quantity sufficient to provide from
about 0.01 mole to about 100 moles per mole of titanium in the
procatalyst. It is preferred that the SCA is provided in a quantity
sufficient to provide from about 0.5 mole to about 70 moles per
mole of titanium in the procatalyst, with about 8 moles to about 50
moles being more preferred.
[0064] Nonlimiting examples of suitable silicon compounds for the
SCA include those mentioned in U.S. Pat. No. 7,491,670,
WO2009/029486, or WO2009/029487 and any combinations thereof. The
SCA can be a mixture of at least 2 silicon compounds (i.e., a mixed
SCA, or mixed external electron donor, or "MEED"). A MEED may
comprise two or more of any of the foregoing SCA compounds. A
preferred mixture can be dicyclopentyldimethoxysilane and
methylcyclohexyldimethoxysilane, dicyclopentyldimethoxysilane and
tetraethoxysilane, or dicyclopentyldimethoxysilane and
n-propyltriethoxysilane.
ALA
[0065] The catalyst composition may include an activity limiting
agent (ALA). As used herein, an "activity limiting agent" ("ALA")
is a material that reduces catalyst activity at elevated
temperature (i.e., temperature greater than about 85.degree. C.).
An ALA inhibits or otherwise prevents polymerization reactor upset
and ensures continuity of the polymerization process. Typically,
the activity of Ziegler-Natta catalysts increases as the reactor
temperature rises. Ziegler-Natta catalysts also typically maintain
high activity near the melting point temperature of the polymer
produced. The heat generated by the exothermic polymerization
reaction may cause polymer particles to form agglomerates and may
ultimately lead to disruption of continuity for the polymer
production process. The ALA reduces catalyst activity at elevated
temperature, thereby preventing reactor upset, reducing (or
preventing) particle agglomeration, and ensuring continuity of the
polymerization process.
[0066] The ALA may or may not be a component of the SCA and/or the
MEED. The activity limiting agent may be a carboxylic acid ester, a
diether, a poly(alkene glycol), a diol ester, and combinations
thereof. The carboxylic acid ester can be an aliphatic or aromatic,
mono- or poly-carboxylic acid ester. Nonlimiting examples of
suitable monocarboxylic acid esters include ethyl and methyl
benzoate, ethyl p-methoxybenzoate, methyl p-ethoxybenzoate, ethyl
p-ethoxybenzoate, ethyl acrylate, methyl methacrylate, ethyl
acetate, ethyl p-chlorobenzoate, hexyl p-aminobenzoate, isopropyl
naphthenate, n-amyl toluate, ethyl cyclohexanoate and propyl
pivalate.
[0067] Nonlimiting examples of suitable ALAs include those
disclosed in WO2009085649, WO2009029487, WO2009029447, or
WO2005030815, and combinations thereof.
[0068] The SCA and/or ALA can be added into the reactor separately.
Alternatively, the SCA and the ALA can be mixed together in advance
and then added to the catalyst composition and/or into the reactor
as a mixture. In the mixture, more than one SCA or more than one
ALA can be used. A preferred mixture is
dicyclopentyldimethoxysilane and isopropyl myristate,
dicyclopentyldimethoxysilane and poly(ethylene glycol) laurate,
dicyclopentyldimethoxysilane and isopropyl myristate and
poly(ethylene glycol) dioleate, methylcyclohexyldimethoxysilane and
isopropyl myristate, n-propyltrimethoxysilane and isopropyl
myristate, dimethyldimethoxysilane and
methylcyclohexyldimethoxysilane and isopropyl myristate,
dicyclopentyldimethoxysilane and n-propyltriethoxysilane and
isopropyl myristate, and dicyclopentyldimethoxysilane and
tetraethoxysilane and isopropyl myristate, and combinations
thereof.
[0069] The catalyst composition may include any of the foregoing
SCAs or MEEDs in combination with any of the foregoing activity
limiting agents (or ALAs).
Preparation of the Catalyst or Catalyst Composition
[0070] The components of the olefin polymerization catalyst can be
contacted by mixing in a suitable reactor outside the system in
which olefin is to be polymerized and the catalyst thereby produced
subsequently is introduced into the polymerization reactor. The
premixed components may be dried after contact or left in the
contact solvent. Alternatively, however, the catalyst components
may be introduced separately into the polymerization reactor. As
another alternative, two or more of the components may be mixed
partially or completely with each other (e.g. premixing SCA and
cocatalyst, or premixing the SCA and ALA) prior to being introduced
into the polymerization reactor. Another alternative is to contact
the supported catalyst component with an organoaluminum compound
prior to reaction with the other catalyst components. A different
alternative is to pre-polymerize a small amount of olefin with the
catalyst components or put any of the components on a support
(e.g., silica or a non-reactive polymer).
Polymerization
[0071] One or more olefin monomers can be introduced into a
polymerization reactor to react with the catalyst and to form a
polymer, or a fluidized bed of polymer particles. Nonlimiting
examples of suitable olefin monomers include ethylene, propylene,
C.sub.4-20 .alpha.-olefins, such as 1-butene, 1-pentene, 1-hexene,
4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene and
the like; C.sub.4-20 diolefins, such as 1,3-butadiene,
1,3-pentadiene, norbornadiene, 5-ethylidene-2-norbornene (ENB), and
dicyclopentadiene; C.sub.8-40 vinyl aromatic compounds including
styrene, o-, m-, and p-methylstyrene, divinylbenzene,
vinylbiphenyl, vinylnapthalene; and halogen-substituted C.sub.8-40
vinyl aromatic compounds such as chlorostyrene and
fluorostyrene.
[0072] As used herein, "polymerization conditions" are temperature
and pressure parameters within a polymerization reactor suitable
for promoting polymerization between the catalyst composition and
an olefin to form the desired polymer. The polymerization process
may be a gas phase, a slurry, or a bulk polymerization process,
operating in one, or more than one, polymerization reactor.
Accordingly, the polymerization reactor may be a gas phase
polymerization reactor, a liquid-phase polymerization reactor, or a
combination thereof.
[0073] It is understood that provision of hydrogen in the
polymerization reactor is a component of the polymerization
conditions. During polymerization, hydrogen is a chain transfer
agent and affects the molecular weight (and correspondingly the
melt flow rate) of the resultant polymer.
[0074] Polymerization may occur by way of gas phase polymerization.
As used herein, "gas phase polymerization" is the passage of an
ascending fluidizing medium, the fluidizing medium containing one
or more monomers, in the presence of a catalyst through a fluidized
bed of polymer particles maintained in a fluidized state by the
fluidizing medium. "Fluidization," "fluidized," or "fluidizing" is
a gas-solid contacting process in which a bed of finely divided
polymer particles is lifted and agitated by a rising stream of gas.
Fluidization occurs in a bed of particulates when an upward flow of
fluid through the interstices of the bed of particles attains a
pressure differential and frictional resistance increment exceeding
particulate weight. Thus, a "fluidized bed" is a plurality of
polymer particles suspended in a fluidized state by a stream of a
fluidizing medium. A "fluidizing medium" is one or more olefin
gases, optionally a carrier gas (such as H.sub.2 or N.sub.2) and
optionally a liquid (such as a hydrocarbon) which ascends through
the gas-phase reactor.
[0075] A typical gas-phase polymerization reactor (or gas phase
reactor) includes a vessel (i.e., the reactor), the fluidized bed,
a distribution plate, inlet and outlet piping, a compressor, a
cycle gas cooler or heat exchanger, and a product discharge system.
The vessel includes a reaction zone and a velocity reduction zone,
each of which is located above the distribution plate. The bed is
located in the reaction zone. In an embodiment, the fluidizing
medium includes propylene gas and at least one other gas such as an
olefin and/or a carrier gas such as hydrogen or nitrogen.
[0076] Contacting of the catalyst and the olefin occurs by way of
feeding the catalyst composition into a polymerization reactor and
introducing the olefin into the polymerization reactor. The
cocatalyst can be mixed with the supported catalyst component
(pre-mix) prior to the introduction of the supported catalyst
component into the polymerization reactor. The cocatalyst may also
be added to the polymerization reactor independently of the
supported catalyst component. The independent introduction of the
cocatalyst into the polymerization reactor can occur
simultaneously, or substantially simultaneously, with the supported
catalyst component feed.
[0077] The polymerization process may include a pre-polymerization
step. Pre-polymerization includes contacting a small amount of the
olefin with the procatalyst composition after the supported
catalyst component has been contacted with the co-catalyst and the
SCA and/or the activity limiting agent. Then, the resulting
preactivated catalyst stream is introduced into the polymerization
reaction zone and contacted with the remainder of the olefin
monomer to be polymerized, and optionally one or more of the SCA
components and/or activity limiting agent components.
Pre-polymerization results in the supported catalyst component
being combined with the cocatalyst and the SCA and/or the activity
limiting agent, the combination being dispersed in a matrix of the
formant polymer. Optionally, additional quantities of the SCA
and/or the activity limiting agent may be added.
[0078] The polymerization process may include a pre-activation
step. Pre-activation includes contacting the supported catalyst
component with the co-catalyst and the SCA and/or the activity
limiting agent. The resulting preactivated catalyst stream is
subsequently introduced into the polymerization reaction zone and
contacted with the olefin monomer to be polymerized, and optionally
one or more of the SCA components. Pre-activation results in the
supported catalyst component being combined with the cocatalyst and
the SCA and/or the activity limiting agent. Optionally, additional
quantities of the SCA and/or the activity limiting agent may be
added.
[0079] The process may include mixing the SCA (and optionally the
activity limiting agent) with the supported catalyst component. The
SCA can be complexed with the cocatalyst and mixed with the
supported catalyst component (pre-mix) prior to contact between the
catalyst composition and the olefin. The SCA and/or the activity
limiting agent can be added independently to the polymerization
reactor. Preferred SCAs include dicyclopentyldimethoxysilane or
n-propyltrimethoxysilane.
[0080] A preferred catalyst composition includes an SCA such as
dicyclopentyldimethoxysilane and/or n-propyltrimethoxysilane and/or
methylcyclohexyldimethoxysilane, and an activity limiting agent
such as isopropyl myristate.
[0081] The olefin may be propylene wherein the process includes
forming a propylene-based polymer having a melt flow rate (MFR)
from about 0.01 g/10 min to about 800 g/10 min, or from about 0.1
g/10 min to about 200 g/10 min, or from about 0.5 g/10 min to about
150 g/10 min. Further, the propylene-based polymer is a
polypropylene homopolymer.
[0082] The olefin may be propylene wherein the process includes
forming a propylene-based polymer having a xylene solubles content
from about 0.5% to about 10%, or from about 1% to about 8%, or from
about 1% to about 4%. Further, the propylene-based polymer is a
polypropylene homopolymer.
[0083] The present disclosure provides another process for
producing an olefin-based polymer. The olefin may be propylene and
a mixture of at least one other suitable olefin comonomer wherein
the process includes forming a propylene-based interpolymer. The
preferred comonomer is ethylene and/or 1-butene and the formant
interpolymer has a melt flow rate (MFR) from about 0.01 g/10 min to
about 200 g/10 min, or from about 0.1 g/10 min to about 100 g/10
min, or from about 0.5 g/10 min to about 70 g/10 min. Further, the
preferred propylene-based interpolymer is a random copolymer.
[0084] The olefin may be propylene and a mixture of at least one
other suitable olefin comonomer wherein the process includes
forming a propylene-based interpolymer. The preferred comonomer is
ethylene and/or 1-butene and the formant interpolymer has a xylene
solubles content from about 0.5% to about 40%, or from about 1% to
about 30%, or from about 1% to about 20%. Further, the preferred
propylene-based interpolymer is a random copolymer.
[0085] The olefin may be propylene and a mixture of at least one
other suitable olefin comonomer wherein the process includes
forming a propylene-based interpolymer. The preferred comonomer is
ethylene and/or 1-butene and the formant interpolymer has a weight
percent comonomer content relative to propylene of from about
0.001% to about 20%, or from about 0.01% to about 15%, or from
about 0.1% to about 10%. Further, the preferred propylene-based
interpolymer is a random copolymer.
[0086] The present disclosure provides another process for
producing an olefin-based polymer. A process for producing an
olefin-based polymer is provided which includes contacting
propylene with a catalyst composition comprising a dicarbonate to
form a propylene-based polymer. The contact between the propylene
and the catalyst composition occurs in a first polymerization
reaction under polymerization conditions. The process further
includes contacting ethylene and optionally at least one other
olefin in the presence of the propylene-based polymer. The contact
between the ethylene, the olefin(s), and the propylene-based
polymer occurs in a second polymerization reactor under
polymerization conditions and forms a propylene impact
copolymer.
[0087] The first reactor and the second reactor may operate in
series whereby the effluent of the first reactor (i.e., the
propylene-based polymer) is charged to the second reactor.
Additional olefin monomer is added to the second polymerization
reactor to continue polymerization. Additional catalyst composition
(and/or any combination of individual catalyst components--i.e.,
supported catalyst component, cocatalyst, EED or MEED, ALA) may be
added to the second polymerization reactor. The additional catalyst
composition/components added to the second reactor may be the same
or different than the catalyst composition/components introduced in
the first reactor.
[0088] The propylene-based polymer produced in the first reactor is
a propylene homopolymer. The propylene homopolymer is charged to
the second reactor where ethylene and propylene are contacted with
each other in the presence of the propylene homopolymer. This forms
a propylene impact copolymer having a propylene homopolymer
continuous (or matrix) phase and a discontinuous phase (or rubber
phase) selected from a propylene-based copolymer (i.e., a
propylene/ethylene copolymer) or an ethylene-based copolymer (i.e.,
an ethylene/propylene copolymer). The discontinuous phase is
dispersed in the continuous phase.
[0089] The propylene impact copolymer may have an Fc value from
about 1 wt % to about 50 wt %, or from about 10 wt % to about 40 wt
%, or from about 20 wt % to about 30 wt %. As used herein,
"fraction copolymer" ("Fc") is the weight percent of the
discontinuous phase present in the heterophasic copolymer. The Fc
value is based on the total weight of the propylene impact
copolymer.
[0090] The propylene impact copolymer may have an Ec value from
about 1 wt % to about 100 wt %, or from about 20 wt % to about 90
wt %, or from about 30 wt % to about 80 wt %, or from about 40 wt %
about 60 wt %. As used herein, "ethylene content" ("Ec") is the
weight percent of ethylene present in the discontinuous phase of
the propylene impact copolymer. The Ec value is based on the total
weight of the discontinuous (or rubber) phase.
Test Methods
[0091] Polydispersity Index (PDI) is measured by an AR-G2 rheometer
which is a stress control dynamic spectrometer manufactured by TA
Instruments using a method according to Zeichner G. R., Patel P. D.
(1981) "A comprehensive Study of Polypropylene Melt Rheology" Proc.
of the 2nd World Congress of Chemical Eng., Montreal, Canada. An
ETC oven is used to control the temperature at 180.degree.
C..+-.0.1.degree. C. Plant nitrogen purged inside the oven to keep
sample from degradation by oxygen and moisture. A pair of 25 mm in
diameter cone and plate sample holder is used. Samples are compress
molded into 50 mm.times.100 mm.times.2 mm plaque. Samples are cut
into 19 mm square and loaded on the center of the bottom plate. The
geometries of upper cone is (1) Cone angle: 5:42:20 (deg:min:sec);
(2) Diameter: 25 mm; (3) Truncation gap: 149 micron. The geometry
of the bottom plate is 25 mm cylinder. Testing procedure: [0092]
(i) The cone & plate sample holder are heated in the ETC oven
at 180.degree. C. for 2 hours. Then the gap is zeroed under blanket
of nitrogen gas. [0093] (ii) Cone is raised to 2.5 mm and sample
loaded unto the top of the bottom plate. [0094] (iii) Start timing
for 2 minutes. [0095] (iv) The upper cone is immediately lowered to
slightly rest on top of the sample by observing the normal force.
[0096] (v) After two minutes the sample is squeezed down to 165
micron gap by lower the upper cone. [0097] (vi) The normal force is
observed when the normal force down to <0.05 Newton the excess
sample is removed from the edge of the cone and plate sample holder
by a spatula. [0098] (vii) The upper cone is lowered again to the
truncation gap which is 149 micron. [0099] (viii) An Oscillatory
Frequency Sweep test is performed under these conditions: [0100]
Test delayed at 180.degree. C. for 5 minutes. [0101] Frequencies:
628.3 r/s to 0.1 r/s. [0102] Data acquisition rate: 5 point/decade.
[0103] Strain: 10% [0104] (ix) When the test is completed the
crossover modulus (Gc) is detected by the Rheology Advantage Data
Analysis program furnished by TA Instruments. [0105] (x)
PDI=100,000/Gc (in Pa units).
[0106] Melt flow rate (MFR) or "Melt flow" is measured in
accordance with ASTM D 1238-01 test method at 230.degree. C. with a
2.16 kg weight for propylene-based polymers.
[0107] Xylene Solubles (XS) is measured according to the following
procedure. A total of 0.4 g of polymer is dissolved in 20 ml of
xylenes with stirring at 130.degree. C. for 30 minutes. The
solution is then cooled to 25.degree. C., and after 30 minutes the
insoluble polymer fraction is filtered off. The resulting filtrate
is analyzed by Flow Injection Polymer Analysis using a Viscotek
ViscoGEL H-100-3078 column with THF mobile phase flowing at 1.0
ml/min. The column is coupled to a Viscotek Model 302 Triple
Detector Array, with light scattering, viscometer and refractometer
detectors operating at 45.degree. C. Instrument calibration was
maintained with Viscotek PolyCAL.TM. polystyrene standards.
[0108] Final melting point, T.sub.MF or ("TMF"), is the temperature
to melt the most perfect crystal in the sample and is regarded as a
measure for isotacticity and inherent polymer crystallizability.
The test is conducted using a TA Q100 Differential Scanning
calorimeter. A sample is heated from 0.degree. C. to 240.degree. C.
at a rate of 80.degree. C./min, cooled at the same rate to
0.degree. C., then heated again at the same rate up to 150.degree.
C., held at 150.degree. C. for 5 minutes and the heated from
150.degree. C. to 180.degree. C. at 1.25.degree. C./min. The
T.sub.MF is determined from this last cycle by calculating the
onset of the baseline at the end of the heating curve. Testing
Procedure for TMF: [0109] ((1) Calibrate instrument with high
purity indium as standard. [0110] (2) Purge the instrument
head/cell with a constant 50 ml/min flow rate of nitrogen
constantly. [0111] (3) Sample preparation: Compression mold 1.5 g
of powder sample using a 30-G302H-18-CX Wabash Compression Molder
(30 ton): (a) heat mixture at 230.degree. C. for 2 minutes at
contact; (b) compress the sample at the same temperature with 20
ton pressure for 1 minute; (c) cool the sample to 45.degree. F. and
hold for 2 minutes with 20 ton pressure; (d) cut the plaque into 4
of about the same size, stack them together, and repeat steps
(a)-(c) in order to homogenize sample. [0112] (4) Weigh a piece of
sample (preferably between 5 to 8 mg) from the sample plaque and
seal it in a standard aluminum sample pan. Place the sealed pan
containing the sample on the sample side of the instrument
head/cell and place an empty sealed pan in the reference side. If
using the auto sampler, weigh out several different sample
specimens and set up the machine for a sequence. [0113] (5)
Measurements: [0114] (i) Data storage: off [0115] (ii) Ramp
80.00.degree. C./min to 240.00.degree. C. [0116] (iii) Isothermal
for 1.00 min [0117] (iv) Ramp 80.00.degree. C./min to 0.00.degree.
C. [0118] (v) Isothermal for 1.00 min [0119] (vi) Ramp
80.00.degree. C./min to 150.00.degree. C. [0120] (vii) Isothermal
for 5.00 min [0121] (viii) Data storage: on [0122] (ix) Ramp
1.25.degree. C./min to 180.00.degree. C. [0123] (x) End of method
[0124] (6) Calculation: T.sub.MF is determined by the interception
of two lines. Draw one line from the base-line of high temperature.
Draw another line from through the deflection of the curve close to
the end of the curve at high temperature side.
[0125] The following Examples are meant to help illustrate the
present invention but are not intended to limit the scope of the
invention as defined by the claims.
EXAMPLES
[0126] General preparation for the preparation of
5-tert-butyl-3-methyl-1,2-phenylene diethyl dicarbonate (ID-1),
5-tert-butyl-3-methyl-1,2-phenylene diphenyl dicarbonate (ID-2),
and 3,5-diisopropyl-1,2-phenylene diethyl dicarbonate (ID-3): To a
round-bottom flask was charged the appropriate catechol (30 mmol),
pyridine (4.8 g, 60 mmol, 2.0 equiv.), and anhydrous methylene
chloride (60 ml). The flask was immersed in an ice-water bath, and
the appropriate chloroformate (60 mmol, 2.0 equiv.) was added
dropwise. The mixture was raised to room temperature and stirred
overnight. The precipitate was filtered off and washed with
additional methylene chloride. The combined filtrate was washed
with water, saturated NH.sub.4Cl or 1N HCl solutions (aqueous),
water, saturated sodium bicarbonate, and brine consequently, and
dried over magnesium sulfate. After filtration, the filtrate was
concentrated, and the residue was purified by recrystallization or
by flash column chromatography on silica gel.
[0127] 5-tert-butyl-3-methyl-1,2-phenylene diethyl dicarbonate
(ID-1): Prepared from 5-tert-butyl-3-methylbenzene-1,2-diol and
ethyl chloroformate; purified by flash column chromatography on
silica gel to yield a sticky colorless oil (81.4%); .sup.1H NMR
(500 MHz, CDCl.sub.3, ppm) .delta. 7.09-7.11 (m, 2H), 4.32 (q, 2H,
J=9.0 Hz), 4.31 (q, 2H, J=9.0 Hz), 2.25 (s, 3H), 1.38 (t, 3H, J=9.0
Hz), 1.37 (t, 3H, J=9.0 Hz), 1.29 (s, 9H);
[0128] 5-tert-butyl-3-methyl-1,2-phenylene diphenyl dicarbonate
(ID-2): Prepared from 5-tert-butyl-3-methylbenzene-1,2-diol and
phenyl chloroformate; purified by recrystallization from ethanol to
yield a while solid (75.2%); .sup.1H NMR (500 MHz, CDCl.sub.3,
ppm): .delta. 7.35-7.38 (m, 4H), 7.23-7.28 (m, 7H), 7.16-7.17 (m,
1H), 2.36 (s, 3H), 1.32 (s, 9H).
[0129] 3,5-diisopropyl-1,2-phenylene diethyl dicarbonate (ID-3):
Prepared from 3,5-diisopropylbenzene-1,2-diol and ethyl
chloroformate; purified by flash column chromatography on silica
gel to yield a yellow oil (59.1%); .sup.1H NMR (500 MHz,
CDCl.sub.3, ppm) .delta. 7.02 (s, 1H), 6.98 (s, 1H), 4.32 (q, 2H,
J=7.0 Hz), 4.31 (q, 2H, J=7.0 Hz), 3.11 (heptat, 1H, J=7.3 Hz),
2.89 (heptat, 1H, J=7.0 Hz), 1.38 (t, 3H, J=7.3 Hz), 1.37 (t, 3H,
J=7.0 Hz), 1.24 (d, 6H, J=7.0 Hz), 1.22 (d, 6H, J=7.5 Hz).
[0130] Structures of the internal donors which were obtained
commercially (diisobutyl phthalate and diethyl carbonate), or
prepared as described herein, are shown in Table 1.
TABLE-US-00001 TABLE 1 Structure of the Internal Donors used in
Examples: Chemical Name Donor Identity Structure diisobutyl
phthalate (CAS # 84-69-5) DIBP (comparative) ##STR00004## diethyl
carbonate (CAS # 105-58-8) DEC (comparative) ##STR00005##
5-tert-butyl-3-methyl-1,2- phenylene diethyl dicarbonate ID-1
##STR00006## 5-tert-butyl-3-methyl-1,2- phenylene diphenyl
dicarbonate ID-2 ##STR00007## 3,5-diisopropyl-1,2-phenylene diethyl
dicarbonate ID-3 ##STR00008##
Preparation of Supported Catalyst Components
[0131] Under nitrogen, 3.0 g of MagTi (mixed magnesium/titanium
halide alcoholate; CAS #173994-66-6, see U.S. Pat. No. 5,077,357),
the amount of internal electron donor indicated in Table 2 below,
and 60 mL of a 50/50 (vol/vol) mixture of titanium tetrachloride
and chlorobenzene is charged to a vessel equipped with an integral
filter. After heating to 115.degree. C. for 60 minutes with
stirring, the mixture is filtered. The solids are treated with an
additional 60 mL of fresh 50/50 (vol/vol) mixed titanium
tetrachloride/chlorobenzene, and optionally (as indicated in table
2 below), a second charge of internal electron donor, at
115.degree. C. for 30 minutes with stirring. The mixture is
filtered. The solids are again treated with 60 mL of fresh 50/50
(vol/vol) mixed titanium tetrachloride/chlorobenzene at 115.degree.
C. for 30 minutes with stirring. The mixture is filtered. At
ambient temperature, the solids are washed three times with 70 mL
of isooctane, then dried under a stream of nitrogen. The solid
catalyst components are collected as powders and a portion is mixed
with mineral oil to produce a 5.4 wt % slurry. The identity of
internal electron donor used, their amounts, and timing of addition
are detailed below (Table 2).
TABLE-US-00002 TABLE 2 Amounts of Internal Donors Used for
Supported Catalyst Components Solid Catalyst Internal mmol donor
mmol donor Designation Electron Donor (1st hot addition) (2nd hot
addition) Comp 1a DIBP 2.42 0.0 Comp 1b DIBP 2.42 0.0 Comp 2 DEC
2.42 0.0 Cat 1-1 ID-1 2.42 0.0 Cat 1-2 ID-1 2.42 2.42 Cat 2 ID-2
2.42 0.00 Cat 3 ID-3 2.42 0.0
Generation of Active Polymerization Catalyst
[0132] In an inert atmosphere glovebox the active catalyst mixture
is prepared by premixing the quantities indicated in Tables 3-4 of
external donor (if present), triethylaluminum (as a 0.28 M
solution), supported catalyst component (as a 5.4% mineral oil
slurry), and 5-10 mL isooctane diluent (optional) for 20 minutes.
After preparation, and without exposure to air, the active catalyst
mixture is injected into the polymerization reactor as described
below.
Batch Reactor Propylene Polymerization (Homopolymer):
[0133] Polymerizations are conducted in a stirred, 3.8 L stainless
steel autoclave.
[0134] Temperature control is maintained by heating or cooling an
integrated reactor jacket using circulated water. The top of the
reactor is unbolted after each run so that the contents can be
emptied after venting the volatiles. All chemicals used for
polymerization or catalyst preparation are run through purification
columns to remove impurities. Propylene and solvents are passed
through 2 columns, the first containing alumina, the second
containing a purifying reactant (Q5.TM. available from Engelhard
Corporation). Nitrogen and hydrogen gases are passed through a
single column containing Q5.TM. reactant.
[0135] After attaching the reactor head to the body, the reactor is
purged with nitrogen while being heated to 140.degree. C. and then
while cooling to approximately 30.degree. C. The reactor is then
filled with a solution of diethylaluminum chloride in isooctane (1
wt %) and agitated for 15 minutes. This scavenging solution is then
flushed to a recovery tank and the reactor is filled with
.about.1375 g of propylene. The appropriate amount of hydrogen is
added using a mass flow meter (see Tables 3-4) and the reactor is
brought to 62.degree. C. The active catalyst mixture is injected as
a slurry in oil or light hydrocarbon and the injector is flushed
with isooctane three times to ensure complete delivery. After
injection of catalyst, the reactor temperature is ramped to
67.degree. C. over 5 minutes, or maintained at 67.degree. C. via
cooling in the case of large exotherms. After a run time of 1 hour,
the reactor is cooled to ambient temperature, vented, and the
contents are emptied. Polymer weights are measured after drying
overnight or to constant weight in a ventilated fume hood.
TABLE-US-00003 TABLE 3 Polymerization Results at 0.41 mol %
(H.sub.2/C.sub.3) Conditions: 200 mg catalyst slurry; 0.15 mmol
external donor; 1.5 mmol Al Example Solid Catalyst Internal
External Yield Melt Flow TMF Eff (kg # Designation Donor Donor PP
(g) (g/10 min) XS (.degree. C.) PDI PP/g cat) 1c Comp 1a* DIBP
NPTMS 258 21.8 2.8 169.9 4.08 24 2c Comp 2* DEC NPTMS 180 48.9 10.9
-- -- 17 3 Cat 1-1 ID-1 NPTMS 146 16.5 2.3 169.9 4.40 14 4 Cat 1-2
ID-1 NPTMS 184 20.7 2.2 170.9 3.88 17 5c Comp 1a* DIBP DCPDMS 341
7.5 2.9 171.7 4.69 32 6c Comp 2* DEC DCPDMS 367 35.0 11.4 -- -- 34
7 Cat 1-1 ID-1 DCPDMS 326 14.0 2.6 170.1 4.80 31 8 Cat 1-2 ID-1
DCPDMS 389 21.1 3.6 170.8 4.84 36 9 Cat 2 ID-2 DCPDMS 438 9.8 5.5
169.9 4.61 41 10 Cat 3 ID-3 DCPDMS 392 21.9 3.4 -- -- 37 *=
comparative; not an example of the invention "--" = not
determined
Analysis of the data in Table 3 reveals the following: [0136] A.
The XS of polymer from catalysts employing any of the inventive
dicarbonate donors is much lower than when using the monocarbonate
comparative catalyst (Comp 2). [0137] B. When using NPTMS as an
external donor, the TMF of polymer from the catalyst employing
inventive donor (ID-1; Cat 1-2) is higher than when using the
comparative catalyst (Comp 1a). [0138] C. When using NPTMS as an
external donor, the XS of polymer from both catalysts employing
inventive donors (ID-1) is lower than when using the comparative
catalyst (Comp 1a or Comp 2). [0139] D. When using DCPDMS as an
external donor, the MF of polymer from catalysts employing any of
the inventive donors is higher than when using the comparative
catalyst (Comp 1a). [0140] E. Efficiency of the inventive catalysts
is strong (>14 kg PP/g catalyst). [0141] F. Efficiency of the
inventive catalyst employing inventive donor (ID-2 or ID-3) is
higher than when using the comparative catalysts (Comp 1a or Comp
2).
TABLE-US-00004 [0141] TABLE 4 Polymerization Results at 0.82 mol %
(H.sub.2/C.sub.3) Conditions: 200 mg catalyst slurry; 0.15 mmol
external donor; 1.5 mmol Al Example Solid Catalyst Internal
External Yield Melt Flow TMF Eff (kg # Designation Donor Donor PP
(g) (g/10 min) XS (.degree. C.) PDI PP/g cat) 11c Comp 1b* DIBP
DCPDMS 447 19.7 2.7 171.3 4.94 42 12 Cat 1-1 ID-1 DCPDMS 322 87.3
2.7 170.8 4.09 30 13 Cat 1-2 ID-1 DCPDMS 308 86.6 2.3 170.4 hmf 29
*= comparative; not an example of the invention hmf = polymer is
"high melt flow" and yields a PDI measurement which must be
extrapolated
Analysis of the data in Table 4 reveals the following: [0142] A.
The XS of polymer from the catalyst employing inventive donor
(ID-1; Cat 1-2) is lower than when using the comparative catalyst.
[0143] B. The PDI of polymer from catalysts employing inventive
donor (ID-1) is narrower than when using the comparative catalyst.
[0144] C. The MF increase of polymer from catalysts employing any
of the inventive donors is substantial relative to when the
comparative catalyst is used. Therefore, higher MF polymer resin
can be made without cracking. [0145] D. Efficiency of the inventive
catalysts is very strong (>29 kg PP/g catalyst).
* * * * *