U.S. patent application number 12/974548 was filed with the patent office on 2012-06-21 for process for producing procatalyst composition with alkoxyalkyl ester internal electron donor and product.
Invention is credited to Linfeng Chen, Kelly Gonzalez, Tak W. Leung, Tao Tao.
Application Number | 20120157295 12/974548 |
Document ID | / |
Family ID | 45218934 |
Filed Date | 2012-06-21 |
United States Patent
Application |
20120157295 |
Kind Code |
A1 |
Chen; Linfeng ; et
al. |
June 21, 2012 |
Process for Producing Procatalyst Composition with Alkoxyalkyl
Ester Internal Electron Donor and Product
Abstract
Disclosed herein are processes for preparing procatalyst
compositions with an internal electron donor containing greater
than 4.5 wt % of a compounded alkoxyalkyl ester. Also disclosed are
catalyst compositions containing the procatalyst composition and
polymers, i.e., propylene-based polymers, produced therefrom. The
present procatalyst compositions improve catalyst selectivity,
catalyst activity, procatalyst morphology and polymer particle
morphology, and improve hydrogen response during olefin
polymerization.
Inventors: |
Chen; Linfeng; (Missouri
City, TX) ; Leung; Tak W.; (Houston, TX) ;
Gonzalez; Kelly; (Katy, TX) ; Tao; Tao;
(Houston, TX) |
Family ID: |
45218934 |
Appl. No.: |
12/974548 |
Filed: |
December 21, 2010 |
Current U.S.
Class: |
502/107 ;
502/104; 502/126 |
Current CPC
Class: |
C08F 10/00 20130101;
C08F 10/00 20130101; C08F 110/06 20130101; C08F 2500/12 20130101;
C08F 4/651 20130101; C08F 2500/24 20130101; C08F 2500/18 20130101;
C08F 110/06 20130101; C08F 4/6498 20130101 |
Class at
Publication: |
502/107 ;
502/104; 502/126 |
International
Class: |
B01J 37/22 20060101
B01J037/22; B01J 37/08 20060101 B01J037/08; B01J 31/14 20060101
B01J031/14 |
Claims
1. A process comprising: first contacting a procatalyst precursor
with an alkoxyalkyl ester and a halogenating agent to form a
procatalyst intermediate; second contacting the procatalyst
intermediate with an alkoxyalkyl ester that is the same or
different than the alkoxyalkyl ester in the first contacting, and a
halogenating agent; and forming a procatalyst composition
comprising a combination of a magnesium moiety, a titanium moiety
and the alkoxyalkyl ester.
2. The process of claim 1 comprising forming a procatalyst
composition comprising a combination of a magnesium moiety, a
titanium moiety and greater than 4.5 wt % of the alkoxyalkyl
ester.
3. The process of claim 1 wherein the first contacting comprises
adding a first alkoxyalkyl ester and a second alkoxyalkyl ester to
the reaction mixture.
4. The process of claim 1 wherein the second contacting comprises
adding a first alkoxyalkyl ester and a second alkoxyalkyl ester to
the procatalyst intermediate.
5. The process of claim 1 wherein the first contacting occurs in a
reaction mixture, the process comprising reacting the halogenating
agent with the procatalyst precursor in a reaction mixture having a
temperature from 30.degree. C. to 150.degree. C.; and adding the
alkoxyalkyl ester from greater than 0 minutes to about 30 minutes
after the reacting.
6. The process of claim 1 comprising third contacting the
procatalyst intermediate with an alkoxyalkyl ester and a
halogenating agent; and forming a procatalyst composition
comprising greater than 5.0 wt % alkoxyalkyl ester.
7. A process comprising: first halogenating a procatalyst precursor
to form a reaction mixture; heating the reaction mixture to a
temperature from 30.degree. C. to 150.degree. C.; first adding an
alkoxyalkyl ester to the reaction mixture from greater than 0
minutes to 30 minutes after the heating to form a procatalyst
intermediate; second halogenating the procatalyst intermediate;
second adding an alkoxyalkyl ester to the procatalyst intermediate;
and forming particles of a procatalyst composition, the particles
having a particle size distribution (PSD) span of less than
2.0.
8. The process of claim 7 comprising second heating the procatalyst
intermediate to a temperature from 30.degree. C. to 150.degree. C.
before the second adding.
9. The process of claim 7 comprising forming a procatalyst
composition comprising a combination of a magnesium moiety, a
titanium moiety and greater than 5.0 wt % of the alkoxyalkyl
ester.
10. A procatalyst composition comprising: a combination of a
magnesium moiety, a titanium moiety, and greater than 4.5 wt % of a
compounded alkoxyalkyl ester.
11. The procatalyst composition of claim 10 wherein the alkoxyalkyl
ester has the structure (I) ##STR00061## wherein R, R.sub.1 and
R.sub.2 are the same or different, each of R and R.sub.1 is
selected from the group consisting of a C.sub.1-C.sub.20 primary
alkyl group, a substituted C.sub.1-C.sub.20 primary alkyl group,
and a C.sub.2-C.sub.20 alkene group; and R.sub.2 is selected from
the group consisting of hydrogen, a C.sub.1-C.sub.20 primary alkyl
group, a substituted C.sub.1-C.sub.20 primary alkyl group, and a
C.sub.2-C.sub.20 alkene group.
12. The procatalyst composition of claim 10 wherein the alkoxyalkyl
ester is an aromatic alkoxyethyl ester with the structure (III)
##STR00062## wherein R.sub.1 and R.sub.2 are the same or different,
R.sub.1 is selected from the group consisting of a C.sub.1-C.sub.20
primary alkyl group, a substituted C.sub.1-C.sub.20 primary alkyl
group, and a C.sub.2-C.sub.20 alkene group; R.sub.2 is selected
from the group consisting of hydrogen, a C.sub.1-C.sub.20 primary
alkyl group, a substituted C.sub.1-C.sub.20 primary alkyl group,
and a C.sub.2-C.sub.20 alkene group; and R.sub.3, R.sub.4, R.sub.5
are the same or different, each of R.sub.3, R.sub.4, R.sub.5 is
selected from the group consisting of a heteroatom, a
C.sub.1-C.sub.20 hydrocarbyl group, a substituted C.sub.1-C.sub.20
hydrocarbyl group, and a C.sub.1-C.sub.20 hydrocarbyloxy group.
13. The procatalyst composition of claim 10 wherein the alkoxyalkyl
ester is 2-methoxy-1-methyethyl benzoate.
14. The procatalyst composition of claim 10 wherein the alkoxyalkyl
ester is 2-methoxyethyl benzoate.
15. A catalyst composition comprising: a procatalyst composition
comprising a combination of a magnesium moiety, a titanium moiety,
and greater than 4.5 wt % of a compounded alkoxyalkyl ester; a
cocatalyst; and optionally an external electron donor.
Description
BACKGROUND
[0001] The present disclosure provides a process for enhancing
procatalyst and catalyst properties. The present disclosure
provides formant polymers produced by these
procatalysts/catalysts.
[0002] Worldwide demand for olefin-based polymers continues to grow
as applications for these polymers become more diverse and more
sophisticated. Known are Ziegler-Natta catalyst compositions for
the production of olefin-based polymers and propylene-based
polymers in particular. Ziegler-Natta catalyst compositions
typically include a procatalyst containing a transition metal
halide (i.e., titanium, chromium, vanadium), a cocatalyst such as
an organoaluminum compound, and optionally an external electron
donor. Many conventional Ziegler-Natta catalyst compositions
include a magnesium chloride-supported titanium chloride
procatalyst with a phthalate-based internal electron donor.
[0003] The health concerns from phthalate exposure are driving the
art to find phthalate substitutes. Known are catalyst compositions
containing an alkoxyalkyl ester (AE) as an internal electron donor
for the production of propylene-based polymers. However,
conventional AE-containing catalysts are currently not viable
because their catalyst activity and/or selectivity are too low for
commercial application. Desirable would be Ziegler-Natta
procatalyst compositions containing an alkoxyalkyl ester internal
electron donor with sufficient catalyst activity/selectivity for
the commercial (i.e., large-scale) production of olefin-based
polymers.
SUMMARY
[0004] The present disclosure provides a process for producing a
Ziegler-Natta procatalyst composition containing an increased
amount of alkoxyalkyl ester as an internal electron donor. The
Applicant has discovered that multiple additions of alkoxyalkyl
ester (including alkoxyalkyl ester containing small/no
substituents) during procatalyst preparation surprisingly improve
catalyst selectivity compared to conventional AE-containing
catalysts which contain a lower amount of alkoxyalkyl ester. In
addition to improved catalyst selectivity, the present procatalyst
composition further exhibits desirable process characteristics
(high hydrogen response, high catalyst activity) and produces
olefin-based polymer, such as propylene-based polymers with low
xylene solubles, high T.sub.MF, good morphology and expanded
in-reactor melt flow range.
[0005] The present disclosure provides a process. In an embodiment,
a process is provided and includes first contacting a procatalyst
precursor with an alkoxyalkyl ester and a halogenating agent to
form a procatalyst intermediate. The process includes second
contacting the procatalyst intermediate with an alkoxyalkyl ester
that is the same or different than the alkoxyalkyl ester in the
first contacting, and a halogenating agent. The process further
includes forming a procatalyst composition comprising a combination
of a magnesium moiety, a titanium moiety and the alkoxyalkyl
ester.
[0006] The present disclosure provides another process. In an
embodiment, a process is provided and includes first halogenating a
procatalyst precursor to form a reaction mixture, and heating the
reaction mixture to a temperature from 30.degree. C. to 150.degree.
C. The process includes first adding an alkoxyalkyl ester to the
reaction mixture from greater than 0 minutes to 30 minutes after
the heating to form a procatalyst intermediate. The process
includes second halogenating the procatalyst intermediate and
second adding an alkoxyalkyl ester to the procatalyst intermediate.
The process includes forming particles of a procatalyst
composition, the particles having a particle size distribution
(PSD) span of less than 2.0.
[0007] The present disclosure provides a composition. In an
embodiment, a procatalyst composition is provided and includes a
combination of a magnesium moiety, a titanium moiety, and greater
than 4.5 wt % of a compounded alkoxyalkyl ester.
[0008] The present disclosure provides another composition. In an
embodiment, a catalyst composition is provided and includes any
procatalyst composition disclosed herein, a cocatalyst, and
optionally an external electron donor.
[0009] An advantage of the present disclosure is the provision of
an improved procatalyst/catalyst composition.
[0010] An advantage of the present disclosure is the provision of a
procatalyst/catalyst composition with improved selectivity for the
polymerization of olefin-based polymers.
[0011] An advantage of the present disclosure is a phthalate-free
procatalyst/catalyst composition.
[0012] An advantage of the present disclosure is the provision of a
phthalate-free catalyst composition and a phthalate-free
olefin-based polymer produced therefrom.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1A is a graph showing catalyst particle size versus the
delay in alkoxyalkyl ester addition in accordance with an
embodiment of the present disclosure.
[0014] FIG. 1B is a graph showing catalyst particle size
distribution (PSD) span versus the delay in alkoxyalkyl ester
addition in accordance with an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0015] The present disclosure provides a process for producing a
procatalyst composition having an alkoxyalkyl ester as an internal
electron donor. The present process improves one or more of the
following procatalyst properties: activity, selectivity, hydrogen
response, and/or particle morphology.
[0016] In an embodiment, a process for producing a procatalyst
composition is provided. The process includes first contacting a
procatalyst precursor with an alkoxyalkyl ester and a halogenating
agent to form a procatalyst intermediate. The process further
includes second contacting the procatalyst intermediate with an
alkoxyalkyl ester and a halogenating agent. The process includes
forming a procatalyst composition comprising a combination of a
magnesium moiety, a titanium moiety and a compounded alkoxyalkyl
ester. The procatalyst composition contains greater than 4.5 wt %
of the compounded alkoxyalkyl ester. Weight percent is based on
total weight of the procatalyst composition.
Procatalyst Precursor
[0017] The procatalyst precursor contains magnesium and may be a
magnesium moiety compound (MagMo), a mixed magnesium titanium
compound (MagTi), or a benzoate-containing magnesium chloride
compound (BenMag). In an embodiment, the procatalyst precursor is a
magnesium moiety ("MagMo") precursor. The "MagMo precursor"
contains magnesium as the sole metal component. The MagMo precursor
includes a magnesium moiety. Nonlimiting examples of suitable
magnesium moieties include anhydrous magnesium chloride and/or its
alcohol adduct, magnesium alkoxide or aryloxide, mixed magnesium
alkoxy halide, and/or carbonated magnesium dialkoxide or aryloxide.
In one embodiment, the MagMo precursor is a magnesium di
(C.sub.1-4) alkoxide. In a further embodiment, the MagMo precursor
is diethoxymagnesium.
[0018] In an embodiment, the procatalyst precursor is a mixed
magnesium/titanium compound ("MagTi"). The "MagTi precursor" has
the formula Mg.sub.dTi(OR.sup.e).sub.fX.sub.g wherein R.sup.e is an
aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon
atoms or COR' wherein R' is an aliphatic or aromatic hydrocarbon
radical having 1 to 14 carbon atoms; each OR.sup.e group is the
same or different; X is independently chlorine, bromine or iodine,
preferably chlorine; d is 0.5 to 56, or 2 to 4; f is 2 to 116 or 5
to 15; and g is 0.5 to 116, or 1 to 3. The MagTi precursor is
prepared by controlled precipitation through removal of an alcohol
from the precursor reaction medium used in their preparation. In an
embodiment, a reaction medium comprises a mixture of an aromatic
liquid, such as a chlorinated aromatic compound, or 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 desirable morphology
and surface area. In a further embodiment, the resulting
procatalyst precursor is a plurality of particles that are uniform
in particle size.
[0019] In an embodiment, the procatalyst precursor is a
benzoate-containing magnesium chloride material. As used herein, a
"benzoate-containing magnesium chloride" ("BenMag") can be a
procatalyst (i.e., a halogenated procatalyst precursor) containing
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 procatalyst 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. In one embodiment, the
benzoate group is ethyl benzoate. Nonlimiting examples of suitable
BenMag procatalyst precursors include procatalysts of the trade
names SHAC.TM. 103 and SHAC.TM. 310 available from The Dow Chemical
Company, Midland, Mich. In an embodiment, the BenMag procatalyst
precursor may be a product of halogenation of any procatalyst
precursor (i.e., a MagMo precursor or a MagTi precursor) in the
presence of a benzoate compound.
[0020] In an embodiment, the procatalyst precursor is synthesized
so as to prepare procatalyst precursor particles having a D50 from
about 5 .mu.m, or about 10 .mu.m to about 100 .mu.m, or to about 50
.mu.m, or to about 25 .mu.m. The precursor preparation may also
include a procedure whereby the particles are formed into rounded,
smooth, spherical or substantially spherical (as opposed to jagged,
rough or uneven) surface morphology. Subsequent halogenation and
formation of the precursor into the procatalyst composition does
not substantially change the D50 size range for the particles.
Thus, the D50 for the procatalyst composition is also from about 5
.mu.m, or about 10 .mu.m to about 100 .mu.m, or to about 50 .mu.m,
or to about 25 .mu.m. The term "D50," as used herein, is the median
particle diameter such that 50% of the sample weight is above the
stated particle diameter.
First Contact
[0021] The present process includes first contacting the
procatalyst precursor with an alkoxyalkyl ester and a halogenating
agent to form a procatalyst intermediate. The term "contacting," or
"contact," or "contact step" in the context of procatalyst
synthesis, is the chemical reaction that occurs in a reaction
mixture (optionally heated) containing a procatalyst
precursor/intermediate, a halogenating agent (with optional
titanating agent) an alkoxyalkyl ester, and a solvent. The reaction
product of "contacting" is a procatalyst composition (or a
procatalyst intermediate) that is a combination of a magnesium
moiety, a titanium moiety, complexed with the alkoxyalkyl ester
(internal electron donor).
[0022] Halogenation (or halogenating) occurs by way of a
halogenating agent. A "halogenating agent," as used herein, is a
compound that converts the procatalyst precursor (or procatalyst
intermediate) into a halide form. A "titanating agent," as used
herein, is a compound that provides the catalytically active
titanium species. Halogenation and titanation convert the magnesium
moiety present in the procatalyst precursor into a magnesium halide
support upon which the titanium moiety (such as a titanium halide)
is deposited.
[0023] In an embodiment, the halogenating agent is a titanium
halide having the formula Ti(OR.sup.e).sub.fX.sub.h wherein R.sup.e
and X are defined as above, f is an integer from 0 to 3; h is an
integer from 1 to 4; and f+h is 4. In this way, the titanium halide
is simultaneously the halogenating agent and the titanating agent.
In a further embodiment, the titanium halide is TiCl.sub.4 and
halogenation occurs by way of chlorination of the procatalyst
precursor with the TiCl.sub.4. The chlorination (and titanation) is
conducted in the presence of a chlorinated or a non-chlorinated
aromatic or aliphatic liquid, such as dichlorobenzene,
o-chlorotoluene, chlorobenzene, benzene, toluene, xylene, octane,
or 1,1,2-trichloroethane. In yet another embodiment, the
halogenation and the titanation are conducted by use of a mixture
of halogenating agent and chlorinated aromatic liquid comprising
from 40 to 60 volume percent halogenating agent, such as
TiCl.sub.4.
[0024] The reaction mixture is heated to a temperature from about
30.degree. C. to about 150.degree. C. for a duration of about 2
minutes to about 100 minutes during halogenation
(chlorination).
Alkoxyalkyl Ester Addition
[0025] The first contact step includes halogenating the procatalyst
precursor in the presence of an alkoxyalkyl ester to form a
procatalyst intermediate. The alkoxyalkyl ester may include the
addition of one, two, or more different alkoxyalkyl esters. The
alkoxyalkyl ester is added before, during, or after the heating of
the reaction mixture. The alkoxyalkyl ester may be added before,
during, or after addition of the halogenating agent to the
procatalyst precursor. At least a portion of the halogenation of
the procatalyst precursor proceeds in the presence of the
alkoxyalkyl ester. The alkoxyalkyl ester is an internal electron
donor. As used herein, an "internal electron donor" (or "IED") is a
compound added or otherwise formed during formation of the
procatalyst composition that donates at least one pair of electrons
to one or more metals present in the resultant procatalyst
composition. Not wishing to be bound by any particular theory, it
is believed that during halogenation (and titanation) the internal
electron donor (1) regulates the formation of active sites and
thereby enhances catalyst stereoselectivity, (2) regulates the
position of titanium on the magnesium-based support, (3)
facilitates conversion of the magnesium and titanium moieties into
respective halides and (4) regulates the crystallite size of the
magnesium halide support during conversion. Thus, provision of the
internal electron donor yields a procatalyst composition with
enhanced stereoselectivity.
[0026] In an embodiment, the alkoxyalkyl ester (or "AE") is an
alkoxyethyl ester. The alkoxyethyl ester has the structure (I) set
forth below.
##STR00001##
[0027] R, R.sub.1 and R.sub.2 are the same or different. Each of R,
R.sub.1 and R.sub.2 is selected from hydrogen (except R.sub.1 which
is not hydrogen), a C.sub.1-C.sub.20 hydrocarbyl group, and a
substituted C.sub.1-C.sub.20 hydrocarbyl group. In an embodiment,
each of R.sub.1 and R.sub.2 is selected from a
substituted/unsubstituted C.sub.1-C.sub.20 primary alkyl group or
from a substituted/unsubstituted alkene group with the structure
(II) below.
C(H).dbd.C(R.sub.11)(R.sub.12) (II)
[0028] R.sub.11 and R.sub.12 are the same or different. Each of
R.sub.11 and R.sub.12 is selected from hydrogen and a
C.sub.1-C.sub.18 hydrocarbyl group.
[0029] As used herein, the term "hydrocarbyl" or "hydrocarbon" is a
substituent 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-, alkylaryl-, and alkynyl-groups.
[0030] As used herein, the term "substituted hydrocarbyl" or
"substituted hydrocarbon" is 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" is 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/or a silicon-containing hydrocarbyl
group. As used herein, the term "halohydrocarbyl" group is a
hydrocarbyl group that is substituted with one or more halogen
atoms.
[0031] In an embodiment, the alkoxyalkyl ester is an aromatic
alkoxyalkyl ester (or "AAE"). The aromatic alkoxyalkyl ester may be
an aromatic alkoxyethyl ester with the structure III below.
##STR00002##
[0032] R.sub.1 and R.sub.2 are the same or different. R.sub.1 is
selected from a C.sub.1-C.sub.20 primary alkyl group and a
substituted C.sub.1-C.sub.20 primary alkyl group. R.sub.2 is
selected from hydrogen, a C.sub.1-C.sub.20 primary alkyl group, and
a substituted C.sub.1-C.sub.20 primary alkyl group. In an
embodiment, each of R.sub.1 and R.sub.2 is selected from a
C.sub.1-C.sub.20 primary alkyl group or from an alkene group with
the structure (II) below.
C(H).dbd.C(R.sub.11)(R.sub.12) (II)
[0033] R.sub.11 and R.sub.12 are the same or different. Each of
R.sub.11 and R.sub.12 is selected from hydrogen and a
C.sub.1-C.sub.18 hydrocarbyl group.
[0034] R.sub.3, R.sub.4, R.sub.5 of structure (III) are the same or
different. Each of R.sub.3, R.sub.4, and R.sub.5 is selected from
hydrogen, a heteroatom, a C.sub.1-C.sub.20 hydrocarbyl group, a
substituted C.sub.1-C.sub.20 hydrocarbyl group, and a
C.sub.1-C.sub.20 hydrocarbyloxy group, and any combination
thereof.
[0035] The alkoxyalkyl ester can be any alkoxyalkyl ester as set
forth in Table 1. In an embodiment, the AAE is
2-methoxy-1-methyethyl benzoate.
[0036] In an embodiment, the AAE is 2-methoxyethyl benzoate.
[0037] In an embodiment, the alkoxyalkyl ester includes an acrylate
moiety and has the structure (IV) below.
##STR00003##
[0038] R.sub.1 and R.sub.2 are the same or different. Each of
R.sub.1 and R.sub.2 is selected from hydrogen (except R.sub.1 which
is not hydrogen), a C.sub.1-C.sub.20 hydrocarbyl group, and a
substituted C.sub.1-C.sub.20 hydrocarbyl group and combinations
thereof. In an embodiment, each of R.sub.1 and R.sub.2 is selected
from a substituted/unsubstituted C.sub.1-C.sub.20 primary alkyl
group or from an alkene group with the structure (II) below.
C(H).dbd.C(R.sub.11)(R.sub.12) (II)
[0039] R.sub.11 and R.sub.12 are the same or different. Each of
R.sub.11 and R.sub.12 is selected from hydrogen and a
C.sub.1-C.sub.18 hydrocarbyl group.
[0040] R.sub.3, R.sub.4, R.sub.5 of structure (IV) are the same or
different. Each of R.sub.3, R.sub.4, and R.sub.5 is selected from
hydrogen, a heteroatom, a C.sub.1-C.sub.20 hydrocarbyl group, and a
substituted C.sub.1-C.sub.20 hydrocarbyl group and any combination
thereof. R.sub.3, R.sub.4, and/or R.sub.5 may form one or more
rings.
[0041] In an embodiment, the first contact step occurs in a
reaction mixture. The process includes reacting the halogenating
agent with the procatalyst precursor in the reaction mixture and
adding the alkoxyalkyl ester to the reaction mixture from greater
than 0 minutes to about 30 minutes after the reacting. The reaction
mixture may be heated to a temperature from 30.degree. C. to
150.degree. C. before, during, or after the alkoxyalkyl ester
addition to the reaction mixture.
Second Contact
[0042] The first contact step forms a procatalyst intermediate. The
process includes a second contacting the procatalyst intermediate
with an alkoxyalkyl ester and a halogenating agent. In other words,
a halogenating agent and additional alkoxyalkyl ester are added to
the procatalyst intermediate to form the procatalyst composition.
The procatalyst intermediate may be isolated from the initial
reaction mixture prior to being subjected to the second contact
step. The halogenating agent used in the second contact may be the
same or different than the halogenating agent of the first contact.
The alkoxyalkyl ester used in the second contact step may be one,
two, or more different alkoxyalkyl esters.
[0043] During the second contact, the alkoxyalkyl ester may be
added before, during, or after heating of the second reaction
mixture. The alkoxyalkyl ester may be added before, during, or
after addition of the halogenating agent to the procatalyst
intermediate. The reaction mixture of the second contact is heated
to a temperature of 30.degree. C. to 150.degree. C. for a duration
of about 2 minutes to about 100 minutes.
[0044] The first contact step and the second contact step produce
or otherwise form a procatalyst composition. The procatalyst
composition includes a combination of a magnesium moiety, a
titanium moiety, and a compounded alkoxyalkyl ester containing
greater than 4.5 wt % of one or more alkoxyalkyl ester(s). In an
embodiment, the process forms a procatalyst composition with a
compounded alkoxyalkyl ester which contains greater than 5 wt %, or
greater than 7 wt %, or greater than 10 wt % to 15 wt % alkoxyalkyl
ester. Weight percent of the alkoxyalkyl ester is based on total
weight of the procatalyst composition.
[0045] A "compounded alkoxyalkyl ester" as used herein, is an
alkoxyalkyl ester compound complexed to a procatalyst component and
formed by two or more of the foregoing contact steps (i.e.,
halogenation of procatalyst precursor/intermediate in the presence
of one or more alkoxyalkyl esters) during procatalyst synthesis.
The compounded alkoxyalkyl ester is present in the resultant
procatalyst composition in an amount greater than 4.5 wt % (based
on the total weight of the procatalyst composition).
[0046] Applicant has surprisingly discovered that the procatalyst
composition with the compounded alkoxyalkyl ester unexpectedly
produces a procatalyst composition with improved selectivity,
improved catalyst activity, improved hydrogen response, and/or
improved polymer melting point when compared to conventional
alkoxyalkyl ester-containing procatalysts. Conventional alkoxyalkyl
ester-containing procatalysts are single-addition alkoxyalkyl ester
procatalysts and do not contain compounded alkoxyalkyl ester. The
present procatalyst composition, with the compounded alkoxyalkyl
ester (and greater than 4.5 wt % alkoxyalkyl ester), advantageously
contains more alkoxyalkyl ester than conventional alkoxyalkyl
ester-containing procatalysts. The present procatalyst composition
is phthalate-free yet exhibits the same, or improved, selectivity
and/or catalyst activity, hydrogen response, and/or polymer melting
point when compared to phthalate-containing procatalyst
compositions. These improvements make the present procatalyst
composition suitable for commercial polymer production (i.e.,
greater than 10 ton/hr).
[0047] The advantages and improvements of the present procatalyst
composition are unexpected. It is very difficult, if not
impossible, to predict whether a compounded alkoxyalkyl ester will
improve the overall performance of the resultant procatalyst
composition. For example, Applicant observed that for some heavily
substituted alkoxyalkyl ester compounds, such as
1-methoxypropan-1-phenylethyl benzoate and 1-methoxy-2-methylpropan
2-yl benzoate, multiple internal donor additions slightly increase
internal electron donor content in the procatalyst, but do not
improve catalyst selectivity. Bounded by no particular theory, this
may be due to the insufficient binding strength between the
internal electron donor and procatalyst. Other examples include
3-methoxypropyl pivalate, which exhibits higher internal electron
donor content in the procatalyst upon multiple internal electron
donor additions, but has lower selectivity.
[0048] In an embodiment, the present process includes third
contacting the procatalyst intermediate with an alkoxyalkyl ester
and a halogenating agent and subsequently forming a procatalyst
composition containing a combination of a magnesium moiety, a
titanium moiety and a compounded internal electron donor with
greater than 5.0 wt % of the alkoxyalkyl ester. The alkoxyalkyl
ester(s) of the third contact step may be the same or different
than the first AE addition and/or the second AE addition. The
reaction mixture may be the same or different than the reaction
mixture of the first contact and/or the second contact. The
reaction mixture during the third contact step may be heated to a
temperature of 30.degree. C. to 150.degree. C. for a duration of
about 2 minutes to about 100 minutes. In the third contact step,
the alkoxyalkyl ester may be added before, during, or after
heating. The process may include four, five, or more contact
steps.
[0049] In an embodiment, the process includes one or more
halogenation step(s) before or after one or more of the following:
the first contact, the second contact, and the third contact.
[0050] The present disclosure provides another process. In an
embodiment, a process is provided and includes first halogenating a
procatalyst precursor to form a reaction mixture. The process
includes heating the reaction mixture to a temperature from
30.degree. C. to 150.degree. C., and first adding an alkoxyalkyl
ester to the reaction mixture. The first alkoxyalkyl ester addition
occurs from greater than 0 minutes to 30 minutes after the heating.
This forms a procatalyst intermediate. The process further includes
second halogenating the procatalyst intermediate and second adding
an alkoxyalkyl ester to the procatalyst intermediate. The process
further includes forming particles of the procatalyst composition
having a span of less 2.0.
[0051] In an embodiment, the particle span is from 0, or 0.1 to
less than 2.0. In an embodiment, the particle span is from less
than 1.5, or less than 1.0. The term "span," as used herein, is the
width of the distribution of the procatalyst particles based on the
10%, 50% and 90% quantile. Span is calculated by way of the
following equation.
Span = D [ v , 0.9 ] - D [ v , 0.1 ] D [ v , 0.5 ] ##EQU00001##
[0052] The volume median diameter D(v,0.5) is the diameter where
50% of the distribution is above and 50% is below a stated value.
D(v,0.9), is the diameter where 90% of the volume distribution is
below a stated value. D(v,0.1), is the diameter where 10% of the
volume distribution is below a stated value.
[0053] In an embodiment, the process includes halogenating the
procatalyst precursor for about one minute, or about two minutes,
or about three minutes to 30 minutes and subsequently first adding
the alkoxyalkyl ester to the reaction mixture to form the
procatalyst intermediate.
[0054] In an embodiment, the process includes second heating the
procatalyst intermediate to a temperature from 30.degree. C. to
150.degree. C. before the second alkoxyalkyl ester addition.
[0055] In another embodiment, the delayed addition of the
alkoxyalkyl ester (after either the first halogenation and/or the
second halogenation) takes place at a lower temperature, from about
-60.degree. C. to about 30.degree. C.
[0056] Applicant unexpectedly discovered that delayed addition of
the alkoxyalkyl ester improves the procatalyst composition particle
morphology by reducing or eliminating particle agglomeration. In
other words, the process includes initiating a heating profile for
the reaction mixture and waiting a time period after the heat
initiation to first add the alkoxyalkyl ester and form the
procatalyst intermediate. The process includes heating the reaction
mixture and delaying the alkoxyalkyl ester addition after heat
initiation to improve particle size distribution. It is observed
that use of alkoxyalkyl ester as internal electron donor,
especially at high level, has a proclivity toward procatalyst
particle agglomeration. The delayed AE addition after heating the
reaction mixture disclosed herein advantageously eliminates (wholly
or partially) procatalyst particle agglomeration.
[0057] In an embodiment, the process further includes forming
particles of a procatalyst composition that is a combination of a
magnesium moiety, a titanium moiety, and a compounded alkoxyalkyl
ester, the procatalyst composition includes greater than 4.5 wt %,
or greater than 5.0 wt % of the alkoxyalkyl ester.
[0058] Ethoxide content in the procatalyst composition indicates
the completeness of conversion of precursor metal ethoxide into a
metal halide. The multiple halogenation, the multiple contact
steps, and/or delay of AE addition promote conversion of ethoxide
into halide during halogenation. In an embodiment, the process
includes forming a procatalyst composition having from about 0.01
wt %, or 0.05 wt % to about 1.0 wt %, or about 0.7 wt % ethoxide.
Weight percent is based on the total weight of the procatalyst
composition.
[0059] In any of the foregoing processes, the procatalyst
composition may be rinsed or washed with a liquid diluent to remove
unreacted TiCl.sub.4 and may be dried to remove residual liquid,
after or between halogenation steps. Typically the resultant solid
procatalyst composition is washed one or more times with a "wash
liquid," which is a liquid hydrocarbon such as an aliphatic
hydrocarbon such as isopentane, isooctane, isohexane, hexane,
pentane, or octane. Not wishing to be bound by any particular
theory, it is believed that (1) further halogenation and/or (2)
further washing results in desirable modification of the
procatalyst composition, possibly by removal of certain undesired
metal compounds that are soluble in the foregoing diluent.
[0060] The resulting procatalyst composition from any of the
foregoing processes has a titanium content of from about 1.0 wt %,
or about 1.5 wt %, or about 2.0 wt %, to about 6.0 wt %, or about
5.5 wt %, or about 5.0 wt %. The weight ratio of titanium to
magnesium in the solid procatalyst composition 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 compounded alkoxyalkyl ester may be
present in the procatalyst composition in a molar ratio of
compounded alkoxyalkyl ester to magnesium of from about 0.005:1 to
about 1:1, or from about 0.01:1 to about 0.4:1. Weight percent is
based on the total weight of the procatalyst composition.
[0061] Any of the foregoing processes may comprise two or more
embodiments disclosed herein.
Procatalyst Composition
[0062] The present disclosure provides a procatalyst composition
produced by any of the foregoing processes. In an embodiment, a
procatalyst composition is provided and includes a combination of a
magnesium moiety, a titanium moiety, and a compounded alkoxyalkyl
ester. The compounded alkoxyalkyl ester may contain one, two or
more alkoxyalkyl esters. The procatalyst composition contains
greater than 4.5 wt % compounded alkoxyalkyl ester. Weight percent
is based on total weight of the procatalyst composition. In a
further embodiment, the procatalyst composition includes greater
than 5 wt %, or greater than 7 wt %, or greater than 10 wt % to
about 15 wt % of the compounded alkoxyalkyl ester.
[0063] In an embodiment, the magnesium moiety is a magnesium
chloride. The titanium moiety is a titanium chloride.
[0064] In an embodiment, the alkoxyalkyl ester is an alkoxyethyl
ester with the structure (I).
##STR00004##
[0065] R, R.sub.1, and R.sub.2 are the same or different. Each of
R, R.sub.1, and R.sub.2 is selected from hydrogen (except R.sub.1
which is not hydrogen), a C.sub.1-C.sub.20 hydrocarbyl group, a
substituted C.sub.1-C.sub.20 hydrocarbyl group, a
substituted/unsubstituted C.sub.2-C.sub.20 alkene group, and
combinations thereof. In an embodiment, R is an aliphatic
C.sub.1-C.sub.20 hydrocarbyl group, optionally containing one or
more halogen atoms and/or one or more silicon atoms.
[0066] In an embodiment, R.sub.1 and R.sub.2 are the same or
different. Each of R.sub.1 and R.sub.2 is selected from a
C.sub.1-C.sub.20 hydrocarbyl group, a substituted C.sub.1-C.sub.20
hydrocarbyl group. In an embodiment, each of R.sub.1 and R.sub.2 is
selected from a substituted/unsubstituted C.sub.1-C.sub.20 primary
alkyl group or from a substituted/unsubstituted C.sub.2-C.sub.20
alkene group with the structure (II) below.
C(H).dbd.C(R.sub.11)(R.sub.12) (II)
[0067] R.sub.11 and R.sub.12 are the same or different. Each of
R.sub.11 and R.sub.12 is selected from hydrogen and a
C.sub.1-C.sub.18 hydrocarbyl group.
[0068] In an embodiment, the alkoxyalkyl ester is an aromatic
alkoxyalkyl ester (AAE). The aromatic alkoxy ester may be an
aromatic alkoxyethyl ester with the structure (III) below.
##STR00005##
[0069] R.sub.1 and R.sub.2 are the same or different. R.sub.1 is
selected from a C.sub.1-C.sub.20 primary alkyl group and a
substituted C.sub.1-C.sub.20 primary alkyl group. R.sub.2 is
selected from hydrogen, a C.sub.1-C.sub.20 primary alkyl group, and
a substituted C.sub.1-C.sub.20 primary alkyl group. In an
embodiment, each of R.sub.1 and R.sub.2 is selected from a
substituted/unsubstituted C.sub.1-C.sub.20 primary alkyl group or
from a substituted/unsubstituted alkene group with the structure
(II) below.
C(H).dbd.C(R.sub.11)(R.sub.12) (II)
[0070] R.sub.11 and R.sub.12 are the same or different. Each of
R.sub.11 and R.sub.12 is selected from hydrogen and a
C.sub.1-C.sub.18 hydrocarbyl group.
[0071] R.sub.3, R.sub.4, R.sub.5 of structure (III) are the same or
different. Each of R.sub.3, R.sub.4, and R.sub.5 is selected from
hydrogen, a heteroatom, a C.sub.1-C.sub.20 hydrocarbyl group, a
substituted C.sub.1-C.sub.20 hydrocarbyl group, and a
C.sub.1-C.sub.20 hydrocarbyloxy group, and any combination
thereof.
[0072] Nonlimiting examples of suitable alkoxyalkyl esters are
provided in Table 1 below. In an embodiment, the AAE is
2-methoxy-1-methyethyl benzoate.
[0073] In an embodiment, the AAE is 2-ethoxy-1-methyethyl
benzoate.
[0074] In an embodiment, the AAE is 2-methoxyethyl benzoate.
[0075] In an embodiment, the AAE is 2-ethoxyethyl benzoate.
[0076] In an embodiment, the procatalyst composition contains
greater than 5 wt %, or greater than 5 wt % to 15 wt % of a
halo-substituted alkoxyethyl benzoate.
[0077] In an embodiment, the procatalyst composition contains
greater than 10 wt %, or greater than 10 wt % to 15 wt % of an
unsubstituted alkoxyethyl benzoate.
[0078] In an embodiment, the alkoxyalkyl ester includes an acrylate
moiety and has the structure (IV) below.
##STR00006##
[0079] R.sub.1 and R.sub.2 are the same or different. Each of
R.sub.1 and R.sub.2 is selected from hydrogen (except R.sub.1 which
is not hydrogen), a C.sub.1-C.sub.20 hydrocarbyl group, and a
substituted C.sub.1-C.sub.20 hydrocarbyl group. In an embodiment,
each of R.sub.1 and R.sub.2 is selected from a
substituted/unsubstituted C.sub.1-C.sub.20 primary alkyl group or
from substituted/unsubstituted alkene group with the structure (II)
below.
C(H).dbd.C(R.sub.11)(R.sub.12) (II)
[0080] R.sub.11 and R.sub.12 are the same or different. Each of
R.sub.11 and R.sub.12 is selected from hydrogen and a
C.sub.1-C.sub.18 hydrocarbyl group.
[0081] R.sub.3, R.sub.4, R.sub.5 of structure (IV) are the same or
different. Each of R.sub.3, R.sub.4, and R.sub.5 is selected from
hydrogen, a heteroatom, a C.sub.1-C.sub.20 hydrocarbyl group, and a
substituted C.sub.1-C.sub.20 hydrocarbyl group and any combination
thereof. R.sub.3, R.sub.4, and/or R.sub.5 may form one or more
rings.
[0082] The procatalyst composition may comprise two or more
embodiments disclosed herein.
Catalyst Composition
[0083] The present disclosure provides a catalyst composition. In
an embodiment, the catalyst composition includes a procatalyst
composition with a compounded alkoxyalkyl ester containing greater
than 4.5 wt % of an alkoxyalkyl ester (internal electron donor).
The catalyst composition also includes a cocatalyst, and optionally
an external electron donor. The procatalyst composition may be any
of the foregoing procatalyst compositions.
[0084] As used herein, a "cocatalyst" is a substance capable of
converting the procatalyst to an active polymerization catalyst.
The cocatalyst may include hydrides, alkyls, or aryls of aluminum,
lithium, zinc, tin, cadmium, beryllium, magnesium, and combinations
thereof. In an embodiment, the cocatalyst is a hydrocarbyl aluminum
compound represented by the formula RnAlX.sub.3, wherein n=1 2, or
3, R is an alkyl, and X is a halide or alkoxide. In an embodiment,
the cocatalyst is selected from trimethylaluminum,
triethylaluminum, triisobutylaluminum, and tri-n-hexylaluminum.
[0085] Nonlimiting examples of suitable hydrocarbyl aluminum
compounds are as follows: methylaluminoxane, isobutylaluminoxane,
diethylaluminum ethoxide, diisobutylaluminum chloride,
tetraethyldialuminoxane, tetraisobutyldialuminoxane,
diethylaluminum chloride, ethylaluminum dichloride, methylaluminum
dichloride, dimethylaluminum chloride, triisobutylaluminum,
tri-n-hexylaluminum, diisobutylaluminum hydride, di-n-hexylaluminum
hydride, isobutylaluminum dihydride, n-hexylaluminum dihydride,
diisobutylhexylaluminum, isobutyldihexylaluminum,
trimethylaluminum, triethylaluminum, tri-n-propylaluminum,
triisopropylaluminum, tri-n-butylaluminum, tri-n-octylaluminum,
tri-n-decylaluminum, tri-n-dodecylaluminum, diisobutylaluminum
hydride, and di-n-hexylaluminum hydride.
[0086] In an embodiment, the cocatalyst is triethylaluminum. The
molar ratio of aluminum to titanium is from about 5:1 to about
500:1, or from about 10:1 to about 200:1, or from about 15:1 to
about 150:1, or from about 20:1 to about 100:1. In another
embodiment, the molar ratio of aluminum to titanium is about
45:1.
[0087] As used herein, an "external electron donor" (or "EED") is a
compound added independent of procatalyst formation and includes at
least one functional group that is capable of donating a pair of
electrons to a metal atom. Bounded by no particular theory, it is
believed that provision of one or more external electron donors in
the catalyst composition affects 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), and melting point.
[0088] In an embodiment, the EED is a silicon compound having the
general formula (V):
SiR.sub.m(OR').sub.4-m (V)
[0089] wherein R independently each occurrence is hydrogen or a
hydrocarbyl or an amino group, optionally substituted with one or
more substituents containing one or more Group 14, 15, 16, or 17
heteroatoms. R contains up to 20 atoms not counting hydrogen and
halogen. R' is a C.sub.1-20 alkyl group, and m is 0, 1, 2, or 3. In
an embodiment, R is C.sub.6-12 aryl, alkyl or alkylaryl, C.sub.3-12
cycloalkyl, C.sub.3-12 branched alkyl, or C.sub.2-12 cyclic amino
group, R' is C.sub.1-4 alkyl, and m is 1 or 2.
[0090] In an embodiment, the silicon compound is
dicyclopentyldimethoxysilane (DCPDMS),
methylcyclohexyldimethoxysilane (MChDMS), or
n-propyltrimethoxysilane (NPTMS), and any combination thereof.
Polymerization
[0091] Any of the foregoing catalyst compositions may be used in a
polymerization process. In an embodiment, a polymerization process
is provided and includes contacting, under polymerization
conditions, the catalyst composition composed of the procatalyst
composition containing greater than 4.5 wt % of the compounded
alkoxyalkyl ester, a cocatalyst, optionally an external electron
donor with propylene and optionally one or more olefins. The
polymerization forms a propylene-based polymer having less than 6
wt %, or less than 4 wt %, or less than 2.5 wt %, or less than 2 wt
%, or from 0.1 wt % to less than 6 wt % xylene solubles (XS).
Weight percent XS is based on the total weight of the polymer.
[0092] 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.
[0093] The polymerization reaction forms a propylene homopolymer or
a propylene copolymer. Optionally, one or more olefin monomers can
be introduced into a polymerization reactor along with the
propylene to react with the procatalyst, cocatalyst, and EED and to
form a polymer, or a fluidized bed of polymer particles.
Nonlimiting examples of suitable olefin monomers include ethylene,
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.
[0094] In an embodiment, the polymerization process may include a
pre-polymerization step and/or a pre-activation step.
[0095] In an embodiment, the process includes mixing the external
electron donor with the procatalyst composition. The external
electron donor can be complexed with the cocatalyst and mixed with
the procatalyst composition (pre-mixed) prior to contact between
the catalyst composition and the olefin. In another embodiment, the
external electron donor can be added independently to the
polymerization reactor.
[0096] In an embodiment, the process includes forming a
propylene-based polymer (propylene homopolymer or propylene
copolymer) containing an alkoxyalkyl ester. The alkoxyalkyl ester
may be one or more alkoxyalkyl esters in Table 1. The
propylene-based polymer has one or more of the following
properties: [0097] 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; and/or
[0098] a xylene solubles content from about 0.5% to about 10%, or
from about 1.0% to about 8%, or from about 1.0% to about 6%, or
from 0.1% to less than 5%; and/or [0099] a polydispersity index
(PDI) from about 3.0 to about 8.0, and/or [0100] particles thereof
with a bulk density greater than 0.28 g/cc to about 0.50 g/cc.
[0101] The propylene-based polymer may comprise two or more
embodiments disclosed herein.
[0102] In an embodiment, the procatalyst composition the catalyst
composition, and/or the polymer produced therefrom are/is
phthalate-free or are/is otherwise void or devoid of phthalate and
derivatives thereof.
DEFINITIONS
[0103] 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.
[0104] 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.
[0105] 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, n-butyl, t-butyl,
i-butyl (or 2-methylpropyl), etc. The alkyls have 1 and 20 carbon
atoms.
[0106] 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 1 and 20 carbon atoms.
[0107] 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.
[0108] The term, "bulk density," (or "BD") as used herein, is the
density of the polymer produced. Bulk density is determined by
pouring the polymer resin through a standard powder funnel into a
stainless standard cylinder and determining the weight of the resin
for the given volume of the filled cylinder in accordance with ASTM
D 1895B or equivalent.
[0109] 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.
[0110] 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.
[0111] 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.
[0112] 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.
[0113] 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.
[0114] 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 (which usually refers to polymers prepared
from three different types of monomers or comonomers),
tetrapolymers (which usually refers to polymers prepared from four
different types of monomers or comonomers), and the like.
[0115] A "primary alkyl group" has the structure --CH.sub.2R.sub.1
wherein R.sub.1 is hydrogen or a substituted/unsubstituted
hydrocarbyl group.
[0116] 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.
[0117] A "secondary alkyl group" has the structure
--CHR.sub.1R.sub.2 wherein each of R.sub.1 and R.sub.2 is a
substituted/unsubstituted hydrocarbyl group.
[0118] 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, and combinations thereof. Suitable substituted alkyls
include, for example, benzyl, trifluoromethyl and the like.
[0119] A "tertiary alkyl group" has the structure
--CR.sub.1R.sub.2R.sub.3 wherein each of R.sub.1, R.sub.2, and
R.sub.3 is a substituted/unsubstituted hydrocarbyl group.
[0120] Test Methods
[0121] Final melting point T.sub.MF 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 was
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.
[0122] Testing Procedure: [0123] (1) Calibrate instrument with high
purity indium as standard. [0124] (2) Purge the instrument
head/cell with a constant 50 ml/min flow rate of nitrogen
constantly. [0125] (3) Sample preparation: [0126] Compression mold
1.5 g of powder sample using a 30-G302H-18-CX Wabash [0127]
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. [0128] (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. [0129] (5)
Measurements: [0130] (i) Data storage: off [0131] (ii) Ramp
80.00.degree. C./min to 240.00.degree. C. [0132] (iii) Isothermal
for 1.00 min [0133] (iv) Ramp 80.00.degree. C./min to 0.00.degree.
C. [0134] (v) Isothermal for 1.00 min [0135] (vi) Ramp
80.00.degree. C./min to 150.00.degree. C. [0136] (vii) Isothermal
for 5.00 min [0137] (viii) Data storage: on [0138] (ix) Ramp
1.25.degree. C./min to 180.00.degree. C. [0139] (x) End of method
[0140] (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.
[0141] Melt flow rate (MFR) 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.
[0142] 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 2.sup.nd World Congress of Chemical Eng., Montreal, Canada.
An ETC oven is used to control the temperature at 180.degree.
C..+-.0.1.degree. C. Nitrogen is used to purge the inside the oven
to keep the 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 then 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:I); (2) Diameter: 25 mm; (3) Truncation gap: 149
micron. The geometry of the bottom plate is 25 mm cylinder.
[0143] Testing Procedure: [0144] (1) 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. [0145] (2)
Cone is raised to 2.5 mm and sample loaded unto the top of the
bottom plate. [0146] (3) Start timing for 2 minutes. [0147] (4) The
upper cone is immediately lowered to slightly rest on top of the
sample by observing the normal force. [0148] (5) After two minutes
the sample is squeezed down to 165 micron gap by lower the upper
cone. [0149] (6) The normal force is observed. When the normal
force is down to <0.05 Newton the excess sample is removed from
the edge of the cone and plate sample holder by a spatula. [0150]
(7) The upper cone is lowered again to the truncation gap which is
149 micron. [0151] (8) An Oscillatory Frequency Sweep test is
performed under these conditions: [0152] Test delayed at
180.degree. C. for 5 minutes. [0153] Frequencies: 628.3r/s to 0.1
r/s. [0154] Data acquisition rate: 5 point/decade. [0155] Strain:
10% [0156] (9) When the test is completed the crossover modulus
(Gc) is detected by the Rheology Advantage Data Analysis program
furnished by TA Instruments. [0157] (10) PDI=100,000/Gc (in Pa
units).
[0158] PSD (Particle Size Distribution) span is measured according
to Method No. A 8 d (Particle Size Distribution by Laser (Malvern))
provided by GEA Niro
(www.niro.dk/niro/cmsdoc.nsf/WebDoc/ndkw6u9by4). The span is the
width of the distribution based on the 10%, 50% and 90% quantile
and is determined by way of the equation below.
Span = D [ v , 0.9 ] - D [ v , 0.1 ] D [ v , 0.5 ] ##EQU00002##
[0159] The volume median diameter D(v,0.5) is the diameter where
50% of the distribution is above and 50% a stated value. D(v,0.9),
is the diameter where 90% of the volume distribution is below a
stated value. D(v,0.1), is the diameter where 10% of the volume
distribution is below a stated value.
[0160] Xylene Solubles (XS) is measured using a .sup.1H NMR method
as described in U.S. Pat. No. 5,539,309, the entire content of
which is incorporated herein by reference.
[0161] By way of example and not by limitation, examples of the
present disclosure will now be provided.
EXAMPLES
1. Procatalyst Precursor
[0162] MagTi-1 is used as a procatalyst precursor. MagTi-1 is a
mixed Mg/Ti precursor with composition of
Mg.sub.3Ti(OEt).sub.8Cl.sub.2 (prepared according to example 1 in
U.S. Pat. No. 6,825,146). Titanium content for each of the
resultant procatalyst compositions is listed in Table 1. The peaks
for internal donors are assigned according to retention time from
GC analysis.
[0163] A. First Contact
[0164] 3.00 g of MagTi-1 is charged into a flask equipped with
mechanical stirring and with bottom filtration. 60 ml of a mixed
solvent of TiCl.sub.4 and chlorobenzene (1/1 by volume) is
introduced into the flask followed immediately by addition of 2.52
mmol of alkoxyalkyl ester or DiBP. The mixture is heated to
115.degree. C. in 15 minutes and remains at 115.degree. C. for 60
minutes with stirring at 250 rpm before filtering off the
liquid.
[0165] B. Second Contact/Halogenation
[0166] 60 ml of mixed solvent and optionally 2.52 mmol of
alkoxyalkyl ester are added again and the reaction is allowed to
continue at the same desired temperature for 30 minutes with
stirring followed by filtration.
[0167] C. Third Contact/Halogenation
[0168] Same as second halogenation.
[0169] The final procatalyst composition is rinsed three times at
room temperature with 70 ml of isooctane and dried under nitrogen
flow for 2 hours.
[0170] Procatalyst properties are set forth in Table 1 below.
Weight percent is based on total weight of the procatalyst
composition. The data in Table 1 are based on MagTi-1 as the
procatalyst precursor. Abbreviations in Table 1 indicate the
following: EtO--Ethoxide, IED--Internal Electron Donor (complexed
form of AE or DiBP in procatalyst), EB--Ethyl Benzoate,
DiBP--Diisobutyl Phthalate, NM=not measured.
TABLE-US-00001 TABLE 1 1.sup.st AE 2.sup.nd AE 3.sup.rd AE Addition
Addition Addition Ti EtO AE EB Ref # AE Name (mmol) (mmol) (mmol)
(%) (%) (%) (%) DiBP (comparative) ##STR00007## Diisobutyl
phthalate 2.52 2.92 0.53 11.91 1 ##STR00008## 2-methoxyethyl
benzoate 2.52 2.52 2.52 4.87 3.39 0.43 0.40 8.57 11.74 2.04 0.17 2
##STR00009## 2-isopropoxyethyl benzoate 2.52 2.52 2.52 2.52 2.52
2.52 3.63 3.22 2.85 0.42 0.36 0.27 5.69 7.79 12.92 1.12 0.49 0.19 3
##STR00010## 1-methoxypropan-2-yl benzoate 2.52 2.52 2.52 3.48 2.46
0.56 0.49 7.58 12.70 5.55 1.17 4 ##STR00011## 1-methoxypropan-2-yl
benzoate 2.52 2.52 2.52 4.54 2.47 0.85 0.40 7.51 12.96 5.41 1.52 5
##STR00012## 1-methoxypropan-1- phenylethyl benzoate 2.52 2.52 2.52
4.12 3.65 0.90 0.65 2.46 4.89 5.84 3.44 6 ##STR00013##
1-methoxy-3,3- dimethlbutan-2-yl benzoate 2.52 2.52 2.52 2.99 1.98
0.25 0.18 11.64 15.58 0.99 0.65 7 ##STR00014## 1-methoxy-2-
methylpropan 2-yl benzoate 2.52 2.52 2.52 4.11 3.33 NM 0.53 2.17
4.59 4.29 1.98 8 ##STR00015## 3-(methoxymethyl) pentan-3-yl
benzoate 2.52 2.52 2.52 3.75 3.51 0.55 0.62 2.76 4.61 2.41 2.26 9
##STR00016## 1-methoxypropan-2-yl 4-ethylbenzoate 2.52 2.52 2.52
3.20 2.32 0.52 0.39 4.58 10.85 0.06 4.48 11 ##STR00017##
2-methoxyethyl 2,4,6- trichlorobenzoate 2.52 3.19 0.69 5.34 12
##STR00018## 2-methoxyethyl 4-ethoxybenzoate 2.52 2.52 2.52 2.88
2.57 0.28 0.43 2.57 5.97 13 ##STR00019## 1-methoxypropan-2-yl
4-ethoxybenzoate 2.52 2.52 2.52 3.41 1.96 0.65 0.49 5.92 4.20 14
##STR00020## 1-methoxy-3,3- dimethylbutan-2-yl 1-naphthoate 2.52
2.52 2.52 3.00 2.78 0.30 0.33 0.15 1.36 15 ##STR00021##
2-methoxyethyl 3-methylbutanoate 2.52 2.52 2.52 3.87 2.46 0.98 0.40
1.45 20.50 16 ##STR00022## 2-methoxyethyl isobutyrate 2.52 2.52
2.52 3.72 2.11 0.71 0.33 Trace 5.25 17 ##STR00023## 2-methoxyethyl
cyclohexanecarboxylate 2.52 2.52 2.52 3.58 2.42 0.86 0.45 4.50 8.43
18 ##STR00024## 2-methoxyethyl pivalate 2.52 2.52 2.52 3.82 2.53
1.02 0.49 0.92 3.70 19 ##STR00025## 2-ethoxyethyl
2,2,2-trichloroacetate 2.52 2.52 2.52 NM NM 0.98 0.45 trace 1.33 20
##STR00026## 2-methoxyethyl methacrylate 2.52 2.52 2.52 NM NM 0.39
0.35 0.72 5.91 21 ##STR00027## 2-ethoxyethyl methacrylate 2.52 2.52
2.52 3.97 2.39 0.50 0.21 1.72 4.68 22 ##STR00028## 1-methoxypropan-
2-yl acetate 2.52 2.52 2.52 NM NM 1.05 0.47 2.69 4.57 23
##STR00029## 1-methoxypropan-2-yl 3-methylbutanoate 2.52 2.52 2.52
3.91 3.04 0.70 0.37 1.97 8.26 24 ##STR00030## 1-methoxypropan- 2-yl
isobutyrate 2.52 2.52 2.52 3.84 2.84 1.31 0.55 1.57 6.02 25
##STR00031## 1-methoxypropan- 2-yl pivalate 2.52 2.52 2.52 4.67
3.32 0.21 0.41 NM NM 26 ##STR00032## 1-methoxy-3,3-
dimethylbutan-2-yl acetate 2.52 2.52 2.52 4.18 2.97 0.84 0.57 trace
0.11 27 ##STR00033## 1-methoxy-3,3- dimethylbutan-2-yl isobutyrate
2.52 2.52 2.52 3.85 2.71 0.80 0.25 4.69 6.18 28 ##STR00034##
1-methoxy-3,3- dimethylbutan-2-yl cyclohexanecarboxylate 2.52 2.52
2.52 5.24 4.04 0.48 0.38 3.56 5.53 29 ##STR00035##
1-methoxy-2,3-dihydro- 1H-inden-2-yl acetate 2.52 2.52 2.97 0.59
trace
2. Polymerization
[0171] Polymerization is performed in liquid propylene in a
1-gallon autoclave. After conditioning, the reactor is charged with
1375 g of propylene and a targeted amount of hydrogen and brought
to 62.degree. C. 0.25 mmol of dicyclopentyldimethoxysilane is added
to a 0.27 M triethylaluminum solution in isooctane, followed by
addition of a 5.0 wt % procatalyst slurry in mineral oil (actual
solid weight is indicated in Table 2 below). The mixture is
premixed at ambient temperature for 20 minutes before being
injected into the reactor to initiate the polymerization. The
premixed catalyst components are flushed into the reactor with
isooctane using a high pressure catalyst injection pump. After the
exotherm, the temperature is maintained at 67.degree. C. Total
polymerization time was 1 hour.
[0172] Polymer samples are tested for melt flow rate (MFR), xylene
solubles (XS), polydispersity index (PDI), and final melting point
(T.sub.MF). XS is measured using .sup.1H NMR method.
[0173] Catalyst performance and polymer properties are provided in
Table 2 below. [0174] NM=Not measured [0175] N/A=Not available
TABLE-US-00002 [0175] TABLE 2 Number Of Pro- MFR AE catalyst Al/
H.sub.2 (g/10 XS Activity T.sub.MF Ref # AE Additions (mg) EED
(mmol) min) (%) (kg/g-hr) PDI (.degree. C.) DiBP ##STR00036## 1
11.0 6.8 55.8 1.6 2.9 30.5 4.50 172.00 1 ##STR00037## 1 2 17.4 17.4
8.0 8.0 83.5 83.5 5.4 1.7 4.3 3.1 24.4 27.4 2 ##STR00038## 1 2 3
16.7 16.7 16.7 6.8 6.8 6.8 67.0 67.0 67.0 5.5 4.3 5.7 8.1 9.1 8.1
16.5 14.4 10.3 3 ##STR00039## 1 2 16.7 16.7 6.8 6.8 83.5 83.5 5.8
3.4 6.7 3.1 29.6 18.0 4.92 4.48 171.70 4 ##STR00040## 1 2 16.7 16.7
6.8 6.8 83.5 83.5 5.6 3.3 7.1 4.0 31.9 17.8 4.57 4.61 171.63 5
##STR00041## 1 2 16.7 16.7 6.8 6.8 83.5 83.5 5.9 6.7 7.8 7.9 16.2
12.8 4.79 3.95 6 ##STR00042## 1 2 16.7 16.7 8.0 8.0 67.0 67.0 5.4
4.1 8.8 8.1 28.9 26.6 7 ##STR00043## 1 2 16.7 16.7 6.8 6.8 83.5
83.5 7.1 8.3 7.9 8.6 13.9 11.7 4.90 5.08 8 ##STR00044## 1 2 16.7
16.7 6.8 6.8 67.0 44.6 5.9 6.4 9.1 8.7 15.7 14.1 9 ##STR00045## 1 2
16.7 16.7 8.0 8.0 67.0 67.0 9.7 1.5 7.1 4.1 29.1 35.1 4.45 171.26
11 ##STR00046## 1 16.7 6.8 67.0 5.2 8.7 18.8 12 ##STR00047## 1 2
16.7 16.7 8.0 8.0 67.0 67.0 10.2 4.6 10.1 5.8 19.5 16.7 4.83 170.75
13 ##STR00048## 1 2 16.7 16.7 8.0 8.0 67.0 67.0 7.5 4.2 8.7 5.1
26.5 30.4 4.39 171.09 14 ##STR00049## 1 2 17.4 17.4 4.0 4.0 67.0
67.0 12.8 8.6 12.6 11.1 8.5 9.1 16 ##STR00050## 1 2 16.7 16.7 6.8
6.8 67.0 67.0 7.2 6.0 8.6 6.9 16.6 11.0 5.12 20 ##STR00051## 1 2 3
16.7 16.7 16.7 6.8 6.8 6.8 67.0 67.0 67.0 4.0 1.5 1.5 7.0 2.6 2.1
13.5 8.0 3.7 5.03 4.56 4.42 172.32 21 ##STR00052## 1 2 3 16.7 16.7
16.7 6.8 6.8 6.8 67.0 67.0 67.0 5.6 1.7 2.5 6.3 2.3 3.5 12.6 12.9
3.6 4.96 4.53 4.71 172.10 22 ##STR00053## 1 2 3 16.7 16.7 16.7 6.8
6.8 6.8 67.0 67.0 67.0 4.9 3.1 2.7 7.3 4.4 2.5 19.0 15.0 8.8 4.71
4.58 4.48 171.81 23 ##STR00054## 1 2 3 16.7 16.7 16.7 6.8 6.8 6.8
67.0 67.0 67.0 6.7 4.6 2.8 7.1 5.1 3.1 20.3 19.3 16.3 4.82 4.54
4.46 171.80 24 ##STR00055## 1 2 3 16.7 16.7 16.7 6.8 6.8 6.8 67.0
67.0 67.0 6.2 4.0 2.5 7.2 5.6 3.8 19.8 19.5 14.9 4.84 4.86 4.67
171.75 25 ##STR00056## 1 2 3 16.7 16.7 16.7 6.8 6.8 6.8 67.0 67.0
67.0 5.6 3.8 3.0 8.1 6.4 5.2 16.3 16.9 15.0 4.86 4.78 171.12 26
##STR00057## 1 2 17.4 17.4 4.0 4.0 67.0 67.0 3.7 3.0 7.1 6.6 20.1
20.6 27 ##STR00058## 1 2 17.4 17.4 4.0 4.0 67.0 67.0 5.4 4.3 7.7
6.8 34.3 25.9 28 ##STR00059## 1 2 17.4 17.4 4.0 4.0 67.0 67.0 4.6
2.9 8.9 7.0 32.5 23.0 29 ##STR00060## 1 2 16.7 16.7 6.8 6.8 40.2
40.2 4.4 5.9 10.7 10.5 12.3 7.7
[0176] Results
[0177] (1) For compounds without bulky substituent(s), multiple AE
addition leads to significant improvement in polymer isotacticity
as shown in Ref. numbers 1, 3, 4, 9, 12, 13, and 15-25.
[0178] (2) Introduction of a small alkyl group, such as methyl, to
the ethylene moiety of the AE linker increased catalyst activity as
shown in Ref. numbers 4, 9, and 13.
[0179] (3) Presence of bulky group(s) in the AE molecule results in
high XS as shown in Ref. numbers 2, 5-8, 11, 14, and 26-29.
[0180] (4) Bulky group on the ethylene moiety of the AE lowers
catalyst activity in addition to increasing XS as shown in Ref.
numbers 5, 7, 8, 14, and 29.
[0181] (5) Higher AE content in catalyst corresponds to lower XS as
shown in Ref. numbers 1, 3, 4, 9, 12, 13, and 15-24.
[0182] (6) Lower XS and high T.sub.MF are achieved by multiple AE
additions during procatalyst formation as shown in Ref. numbers 1,
3, 4, 9, 12, 13, and 15-25.
[0183] (7) Multiple donor addition of AE with a bulky ending alkoxy
group does not result in XS improvement as shown in Ref. number
2.
3. Delayed Addition of Alkoxyalkyl Ester
[0184] A series of catalysts are made in which the first addition
of alkoxyalkyl ester is delayed from 0 to 5 minutes after heating
the reaction mixture. Table 3 and FIGS. 1A and 1B show that the
agglomeration which occurs with the high AE loading diminishes as
the AE addition delay is increased.
[0185] The procatalyst preparation comprises three TiCl.sub.4
halogenations. The first contact step includes addition of 3.63
mmol of 2-methoxy-1-methylethyl benzoate (AAE) to a suspension of
3.00 g of 50 .mu.m MagTi-1 in 60 ml of a mixed solvent (50%
TiCl.sub.4/chlorobenzene (vol/vol)). The mixture is heated from
ambient temperature to 115.degree. C. in 15 minutes and then held
at this temperature for 60 minutes. For the initial designed set of
experiments, the AE is added to the mixture immediately after
equilibrating the solvent below the frit and before initiating the
temperature ramp. In all remaining experiments, the AE is added
after initiating the temperature ramp.
[0186] The second contact step again utilizes 2.42 mmol of AAE and
60 ml of mixed solvent. The reaction mixture is heated to
115.degree. C. in 15 minutes and maintained at this temperature
with stirring for 30 minutes. The third step, halogenation,
utilizes 60 ml of mixed solvent, but no AE. Again, the reaction is
heated to 115.degree. C. in 15 minutes and then maintained at this
temperature for 30 minutes. The final procatalyst is rinsed three
times in room temperature isooctane and dried under nitrogen flow
for 2 hours.
[0187] Mixed solvent is added to the MagTi-1 precursor (0.5 min)
and the solvent is equilibrated below the frit (3 min). The
addition time delay clock is started when the heat ramp is
initiated. With 0 minutes on the time delay clock, the span is high
(1.3-1.7) and D50 and D90 average 71 .mu.m and 145 .mu.m,
respectively, with notable variation in the contributing data
points. With a 3-minute delay, the particle size distribution span
lined out near 0.5 and D50 and D90 reached 47.5 .mu.m and 62.1
.mu.m, respectively. Delayed addition of the internal electron
donor improves morphology significantly. The best balance in the
catalyst set occurred with the 3-minute delay, where agglomeration
is eliminated and XS increases only slightly.
[0188] Polymerization: Polymerization is performed in liquid
propylene in a 1-gallon autoclave. After conditioning, the reactor
is charged with 1375 g of propylene and 67 mmol of hydrogen and
brought to 62.degree. C. 0.25 mmol of dicyclopentyldimethoxysilane
is added to 7.2 ml of a 0.27 M triethylaluminum solution in
isooctane, followed by addition 0.18 ml of a 5.0 wt % procatalyst
slurry in mineral oil. The mixture is premixed at ambient
temperature for 20 minutes before being injected into the reactor
to initiate the polymerization. The premixed catalyst components
are flushed into the reactor with isooctane using a high pressure
catalyst injection pump. After the exotherm, the temperature is
maintained at 67.degree. C. Total polymerization time is 1
hour.
TABLE-US-00003 TABLE 3 Donor Addition Ti OEt EB Activity (kg PP/g
MFR (10 XS Run # Delay (min.) (%) (%) AAE (%) (%) catalyst/h)
g/min) (%) D50 (.mu.m) D90 (.mu.m) Span A 0 2.18 0.24 12.1 1.10
16.5 3.1 4.3 78.7 170.4 1.7 64.3 121.0 1.3 B 1 2.29 0.21 11.5 0.92
18.7 3.4 4.7 60.4 99.3 1.0 55.1 76.0 0.7 C 3 2.38 0.26 9.2 1.35
18.7 2.8 4.5 47.6 63.6 0.5 47.3 60.6 0.5 D 5 2.17 0.34 8.9 0.95
22.6 3.0 5.0 46.7 59.5 0.5 46.5 58.8 0.4
[0189] It is specifically intended that the present invention not
be limited to the embodiments and illustrations contained herein,
but include modified forms of those embodiments including portions
of the embodiments and combinations of elements of different
embodiments as come within the scope of the following claims.
* * * * *