Mixed catalyst system

It has been found that the use of at least one unsupported metallocene polymerization catalyst with at least one supported metallocene polymerization catalyst in the polymerization of olefins allows for better control of the polymerization, especially gas phase polymerization. Such a system takes advantage of the high activity of the unsupported catalyst and the stability of a supported catalyst. Additionally, the relative timing of the addition of the supported and unsupported catalysts to a reaction system can be used to control a continuous polymerization reaction by stabilizing the reactor bed with the supported catalyst prior to addition of the unsupported catalyst.

FIELD OF THE INVENTION 
The present invention relates to the use of mixed supported and unsupported 
metallocene type catalysts for the polymerization of olefins. 
BACKGROUND OF THE INVENTION 
U.S. Pat. No. 5,317,036 teaches the gas-phase polymerization of olefins 
with metallocene catalysts in liquid form. In such systems resin particle 
size can be controlled by spraying the liquid catalyst into a zone which 
is substantially free of resin as disclosed in U.S. Pat. No. 5,693,727, 
which is incorporated herein by reference. However, it is difficult to 
control the use of these catalysts because of their high activity. 
Supported metallocene catalysts are also known, but these lack high 
activity and are expensive on a polymer pound basis. Thus, it is desirable 
to avoid these problems. 
SUMMARY OF THE INVENTION 
It has been found that the use of at least one unsupported metallocene 
polymerization catalyst with at least one supported metallocene 
polymerization catalyst in the polymerization of olefins allows for better 
control of the polymerization of olefins, especially gas phase 
polymerization. Such a system takes advantage of the high activity of the 
unsupported catalyst and the stability of a supported catalyst and yields 
polymers having lower catalyst residues than polymers produced using 
catalysts that are totally supported. Additionally, the relative timing of 
the addition of the supported and unsupported catalysts to a reaction 
system can be used to control the polymerization reaction. 
DETAILED DESCRIPTION OF THE INVENTION 
At least two metallocene catalysts, present at weight ratio of 1:99 to 
99:1, can be used to provide various molecular weight distribution 
polymers with varying product properties. The use of catalysts in the 
manner taught in this invention allows the production of polymers with 
desirable properties, due to ready control of molecular weight 
distribution and to in-situ intimate mixing of polymers when making 
polymers of different types. In addition to the possibility of shaping of 
the molecular weight distribution by the use of the supported and 
unsupported catalysts, several other features of the molecular 
architecture of the polymer that can be controlled with the proper choice 
of catalysts are: 
1. type of stereoregularity 
2. degree of stereoregularity 
3. type of regioregularity 
4. degree of regioregularity 
5. comonomer content 
6. comonomer distribution statistics 
7. unsaturation 
8. long chain branching 
Catalysts can be selected to provide a targeted amount of stereo-irregular 
material to be made in order to improve processing in end use 
applications. Copolymers may be created in situ because such a catalyst 
system can produce two different types of polymers. The process can be run 
in such a fashion as to allow for in-situ intimate intermingling of the 
polymers that are made; this intermingling provides good product 
properties without the need for an expensive down stream compounding step. 
There may be more than one of each supported and unsupported catalyst, so 
long as there is at least some supported and unsupported metallocene 
catalyst in the system. 
Catalyst 
Any type of metallocene polymerization catalyst may be used in the present 
process. Accordingly, the catalyst composition may comprise any 
metallocene catalyst useful in slurry, solution, bulk, or gas phase olefin 
polymerization. One or more than one metallocene catalyst may be employed. 
For example, as described in U.S. Pat. No. 4,530,914, at least two 
metallocene catalysts may be used in a single catalyst composition to 
achieve a broadened molecular weight distribution polymer product. 
Metallocene catalysts are organometallic coordination complexes of one or 
more Tc-bonded moieties in association with a metal atom from Groups IIIB 
to VIII or the rare earth metals of the Periodic Table. 
Bridged and unbridged mono-, bis-, and tris-cycloalkadienyl/metal compounds 
are the most common metallocene catalysts, and generally are of the 
formula: 
EQU (L).sub.y R.sup.1.sub.z (L")MX.sub.(x-y-1) (I) 
wherein M is a metal from groups IIIB to VIII of the Periodic Table; L and 
L" are the same or different and are .pi.-bonded ligands coordinated to M, 
preferably cycloalkadienyl groups such as cyclopentadienyl, indenyl, or 
fluorenyl groups optionally substituted with one or more hydrocarbyl 
groups containing 1 to 20 carbon atoms; R.sup.1 is a C.sub.1 -C.sub.4 
substituted or unsubstituted alkylene radical, a dialkyl or diaryl 
germanium or silicon, or an alkyl or aryl phosphine or amine radical 
bridging L and L"; each X is independently hydrogen, an aryl, alkyl, 
alkenyl, alkylaryl, or arylalkyl radical having 1-20 carbon atoms, a 
hydrocarboxy radical having 1-20 carbon atoms, a halogen, R.sup.2 CO.sub.2 
--, or R.sup.2.sub.2 NCO.sub.2 --, wherein each R.sup.2 is a hydrocarbyl 
group containing 1 to about 20 carbon atoms; y is 0, 1, or 2; x is 1, 2, 
3, or 4 depending upon the valence state of M; z is 0 or 1 and is 0 when y 
is 0; and x-y.gtoreq.1. 
Illustrative but non-limiting examples of metallocene catalysts represented 
by formula II are dialkyl metallocenes such as 
bis(cyclopentadienyl)titanium dimethyl, bis(cyclopentadienyl)titanium 
diphenyl, bis(cyclopentadienyl)zirconium dimethyl, 
bis(cyclopentadienyl)zirconium diphenyl, bis(cyclopentadienyl)haffium 
methyl and diphenyl, bis(cyclopentadienyl)titanium di-neopentyl, 
bis(cyclopentadienyl)zirconium di-neopentyl, bis(cyclopentadienyl)titanium 
dibenzyl, bis(cyclopentadienyl)zirconiun:L dibenzyl, 
bis(cyclopentadienyl)vanadium dimethyl; mono alkyl metallocenes such as 
bis(cyclopentadienyl)titanium methyl chloride, 
bis(cyclopentadienyl)titanium ethyl chloride, 
bis(cyclopentadienyl)titanium phenyl chloride, 
bis(cyclopentadienyl)zirconium methyl chloride, 
bis(cyclopentadienyl)zirconium ethyl chloride, 
bis(cyclopentadienyl)zirconium phenyl chloride, 
bis(cyclopentadienyl)titanium methyl bromide; trialkyl metallocenes such 
as cyclopentadienyl titanium trimethyl, cyclopentadienyl zirconium 
triphenyl, and cyclopentadienyl zirconium trineopentyl, cyclopentadienyl 
zirconium trimethyl, cyclopentadienyl hafnium triphenyl, cyclopentadienyl 
hafnium trineopentyl, and cyclopentadienyl hafnium trimethyl; 
monocyclopentadienyl titanocenes such as, pentamethylcyclopentadienyl 
titanium trichloride, pentaethylcyclopentadienyl titanium trichloride; the 
carbene represented by the formula 
bis(cyclopentadienyl)titanium.dbd.CH.sub.2 and derivatives of this 
reagent; substituted bis(cyclopentadienyl)titanium (IV) compounds such as: 
bis(indenyl)titanium diphenyl or dichloride, 
bis(methylcyclopentadienyl)titanium diphenyl or dihalide; dialkyl, 
trialkyl, tetraalkyl and pentaalkyl cyclopentadienyl titanium compounds 
such as bis(1,2-dimethylcyclopentadienyl)titanium diphenyl or dichloride, 
bis(1,2-diethylcyclopentadienyl)titanium diphenyl or dichloride, 
bis(pentamethylcyclopentadienyl) titanium cdiphenyl or dichloride; 
silicon, phosphine, amine or carbon bridged cyclopentadiene complexes, 
such as dimethyl silyldicyclopentadienyl titanium diphenyl or dichloride, 
methyl phosphine dicyclopentadienyl titanium diphenyl or dichloride, 
methylenedicyclopentadienyl titanium diphenyl or dichloride and other 
dihalide complexes, and the like; as well as bridged metallocene compounds 
such as isopropyl(cyclopentadienyl)(fluorenyl)zirconium dichloride, 
isopropyl(cyclopentadienyl)(octahydrofluorenyl)zirconium dichloride, 
diisopropylmethylene(cyclopentadienyl)(fluorenyl)zirconium dichloride, 
diisobutylmethylene(cyclopentadienyl)(fluorenyl) zirconium dichloride, 
ditertbutylmethylene(cyclopentadienyl)(fluorenyl)zirconium dichloride, 
cyclohexylidene(cyclopentadienyl)(fluorenyl)zirconium dichloride, 
diisopropylmethylene(2,5-dimethylcyclopentadienyl)(fluorenyl)zirconium 
dichloride, isopropyl(cyclopentadienyl)(fluorenyl)hafniium dichloride, 
diphenylmethylene(cyclopentadienyl)(fluorenyl)hafnium dichloride, 
diisopropylmethylene(cyclopentadienyl)(fluorenyl)hafium dichloride, 
diisobutylmethylene(cyclopentadienyl)(fluorenyl)hafnium dichloride, 
ditertbutylmethylene(cyclopentadienyl)(fluorenyl)hafnium dichloride, 
cyclohexylidene(cyclopentadienyl)(fluorenyl)hafnium dichloride, 
diisopropylmethylene(2,5-dimethylcyclopentadienyl) (fluorenyl)-hafnium 
dichloride, isopropyl(cyclopentadienyl)(fluorenyl)titanium dichloride, 
diphenylmethylene(cyclopentadienyl)(fluorenyl)titanium dichloride, 
diisopropylmethylene(cyclopentadienyl)(fluorenyl)titanium dichloride, 
diisobutylmethylene(cyclopentadienyl)(fluorenyl)titanium dichloride, 
ditertbutylmethylene(cyclopentadienyl)(fluorenyl)titanium dichloride, 
cyclohexylidene(cyclopentadienyl)(fluorenyl)titanium dichloride, 
diisopropylmethylene(2,5 dimethylcyclopentadienyl fluorenyl)titanium 
dichloride, racemic-ethylene bis (1-indenyl)zirconium (W) dichloride, 
racemic-ethylene bis (4,5,6,7-tetrahydro-1-indenyl) zirconium (IV) 
dichloride, racemic-dimethylsilyl bis (1-indenyl) zirconium (IV) 
dichloride, racemic-dirmethylsilyl bis (4,5,6,7-tetrahydro-1-indenyl) 
zirconium (IV) dichloride, racemic-1,1,2,2-tetramethylsilanylene bis 
(1-indenyl) zirconium (IV) dichloride, 
racemic-1,1,2,2-tetramethylsilanylene bis (4,5,6,7-tetrahydro-1-indenyl) 
zirconium (IV) dichloride, ethylidene (1-indenyl 
tetramethylcyclopentadienyl) zirconium (IV) dichloride, 
racemic-dimethylsilyl bis (2-methyl-4-t-butyl-1-cyclopentadienyl) 
zirconium (IV) dichloride, racemic-ethylene bis (1-indenyl) hafnimn (IV) 
dichloride, racemic-ethylene bis (4,5,6,7-tetrahydro-1-indenyl) hafiium 
(IV) dichloride, racemic-dimethylsilyl bis (1-indenyl) hafaium (IV) 
dichloride, racemic-dimethylsilyl bis (4,5,6,7-tetrahydro-1-indenyl) 
hafnium (IV) dichIoride, racemic-1,1,2,2-tetramethylsilanylene bis 
(1-indenyl) hafnium (IV) dichloride, racemic-1,1,2,2-tetramethylsilanylene 
bis (4,5,6,7-tetrahydro-1-indenyl) hafaium (IV), dichloride, ethylidene 
(1-indenyl-2,3,4,5-tetramethyl-1-cyclopentadienyl) hafnium (IV) 
dichloride, racemic-ethylene bis (1-indenyl) titanium (IV) dichloride, 
racemic-ethylene bis (4,5,6,7-tetrahydro-1-indenyl) titanium (IV) 
dichloride, racemic-dimethylsilyl bis (1-indenyl) titanium (IV) 
dichloride, racemic-dimethylsilyl bis (4,5,6,7-tetrahydro-1-indenyl) 
titanium (IV) dichloride, racemic-1,1,2,2-tetramethylsilanylene bis 
(1-indenyl) titanium (IV) dichloride racemic-1,1,2,2-tetramethylsilanylene 
bis (4,5,6,7-tetrahydro-1-indenyl) titanium (IV) dichloride, and 
ethylidene (1-indenyl-2,3,4,5-tetramethyl-1-cyclopentadienyl) titanium IV) 
dichloride. Particularly preferred metallocene catalysts are 
diphenylmethylene (cyclopentadienyl)(fluorenyl)zirconium dichloride, 
racemic-dimethylsilyl bis (2-methyl-1-indenyl) zirconium (IV) dichloride, 
racemic-dimethylsilyl bis (2-methyl-4-(1-naphthyl-1-indenyl) zirconium 
(IV) dichloride, and racemic-dimethylsilyl bis 
(2-methyl-4-phenyl-1-indenyl) zirconium (IV) dichloride. 
Another type of metallocene catalyst that can be used in accordance with 
the invention has one of the following formulas (II or III): 
##STR1## 
wherein: M is a metal from groups IIIB to VIII, preferably Zr or Hf; 
L is a substituted or unsubstituted, .pi.-bonded ligand coordinated to M, 
preferably a substituted cycloalkadienyl ligand; 
each Q is independently selected from the group consisting of --O--, 
--NR.sup.3 --, --CR.sup.3.sub.2 -- and --S--, preferably oxygen; 
Y is either C or S, preferably carbon; 
Z is selected from the group consisting of --OR.sup.3, --NR.sup.3 .sub.2, 
--CR.sup.3.sub.3, --SR.sup.3, --SiR.sup.3.sub.3, --PR.sup.3.sub.2, and 
--H, with the proviso that when Q is --NR.sup.3 -- then Z is selected from 
the group consisting of --OR.sup.3, --NR.sup.3.sub.2, --SR.sup.3, 
--SiR.sup.3.sub.3, --PR.sup.3.sub.2, and --H, preferably Z is selected 
from the group consisting of --OR.sup.3, --CR.sup.3.sub.3, and 
--NR.sup.3.sub.2; 
n is 1 or 2; 
A is a univalent anionic group when n is 2 or A is a divalent anionic group 
when n is 1, preferably A is a carbamate, carboxylate or other heteroallyl 
moiety described by Q, Y and Z combination; and 
each R.sup.3 is independently a group containing carbon, silicon, nitrogen, 
oxygen, and/or phosphorus and one or more R.sup.3 groups may be attached 
to the L substituent, preferably R.sup.3 is a hydrocarbon group containing 
from 1 to 20 carbon atoms, most preferably an alkyl, cycloalkyl or an aryl 
group; 
T is a bridging group selected from the group consisting of alkylene or 
arylene groups containing from 1 to 10 carbon atoms optionally substituted 
with carbon or heteroatoms, germanium, silicone and alkyl phosphine; and 
m is 1 to 7, preferably 2 to 6, most preferably 2 or 3. 
The supportive substituent formed by Q, Y and Z is a unicharged polydentate 
ligand exerting electronic effects due to its high polarizability, similar 
to the cyclopentadienyl group. In the most preferred embodiments of this 
invention, the disubstituted carbamates, 
##STR2## 
and the carboxylates 
##STR3## 
are employed. 
Examples of metallocene catalysts according to formulas II and III include 
indenyl zirconium tris(diethylcarbamate), indenyl zirconium 
tris(pivalate), indenyl zirconium tris(p-toluate), indenyl zirconium 
tris(benzoate), (1-methylindenyl) zirconium tris(pivalate), 
(2-methylindenyl) zirconium tris(diethylcarbamate), 
(methylcyclopentadienyl) zirconium tris(pivalate), cyclopentadienyl 
tris(pivalate), and (pentamethylcyclopentadienyl) zirconium 
tris(benzoate). Preferred examples of these metallocene catalysts are 
indenyl zirconium tris(diethylcarbamate) and indenyl zirconium 
tris(pivalate). 
Another type of metallocene catalyst that can be used in accordance with 
the invention is a constrained geometry catalyst of the formula: 
##STR4## 
wherein: M is a metal of Group IIIB to VIII of the Periodic Table of the 
Elements: 
Cp is a cyclopentadienyl or substituted cyclopentadienyl group bound in an 
.eta..sup.5 bonded mode to M; 
Z" is a moiety comprising boron, or a member of Group IVA of the Periodic 
Table of the Elements and optionally sulfur or oxygen, the moiety having 
up to 20 non-hydrogen atoms, and optionally Cp and Z" together form a 
fused ring system; 
X" is an anionic ligand group or a neutral Lewis base ligand group having 
up to 30 non-hydrogen atoms; 
a is 0, 1, 2, 3 or 4 depending on the valance of M; and 
Y" is an anionic or non-anionic ligand group bonded to Z" and M comprising 
is nitrogen, phosphorus, oxygen or sulfur having up to 20 non-hydrogen 
atoms, and optionally Y" and Z" together form a fused ring system. 
Constrained geometry catalysts are well known to those skilled in the art 
and are disclosed in, for example, U.S. Pat. Nos. 5,026,798 and 5,055,438 
and published European Application No. 0 416 815 A2. 
Illustrative but non-limiting examples of substituents Z", Cp, Y", X" and M 
in formula IV are: 
______________________________________ 
Z" Cp Y" X" M 
______________________________________ 
dimethyl- 
cyclopenta- 
t-butylamido chloride 
titanium 
silyl dienyl 
methyl- fluorenyl phenylamido methyl zirconium 
phenylsilyl 
diphenyl- indenyl cyclohexylamido hafnium 
silyl 
tetramethyl- oxo 
ethylene 
ethylene tetramethyl- 
cyclopenta- 
dienyl 
diphenyl- 
methylene 
______________________________________ 
The invention is also useful with another class of single site catalyst 
precursors, di(imine) metal complexes, as described in PCT Application No. 
WO 96/23010, which is incorporated herein by reference. 
The activating cocatalyst is capable of activating the metallocene 
catalyst. Preferably, the activating cocatalyst is one of the following: 
(a) branched or cyclic oligomeric poly(hydrocarbyl-aluminum oxide)s which 
contain repeating units of the general formula --(Al(R*)O)--, where R* is 
hydrogen, an alkyl radical containing from 1 to about 12 carbon atoms, or 
an aryl radical such as a substituted or unsubstituted phenyl or naphthyl 
group; (b) ionic salts of the general formula [A=][BR**.sub.4 -], where A+ 
is a cationic Lewis or Bronsted acid capable of abstracting an alkyl, 
halogen, or hydrogen from the metallocene catalysts, B is boron, and R** 
is a substituted aromatic hydrocarbon, preferably a perfluorophenyl 
radical; and (c)boron alkyL; of the general formula BR**.sub.3, where R** 
is as defined above. 
Preferably, the activating cocatalyst is an aluminoxane such as 
methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), or a boron 
alkyl. Aluminoxanes are preferred and their method of preparation is well 
known in the art. Aluminoxanes may be in the form of oligomeric linear 
alkyl aluminoxanes represented by the formula: 
##STR5## 
or oligomeric cyclic alkyl aluminoxanes of the formula: 
##STR6## 
wherein s is 1-40, preferably 10-20; p is 3-40, preferably 3-20; and R*** 
is an alkyl group containing 1 to 12 carbon atoms, preferably methyl or an 
aryl radical such as a substituted or unsubstituted phenyl or naphthyl 
radical. In the case of MAO, R*** is methyl, whereas in MMAO, R*** is a 
mixture of methyl and C2 to C12 alkyl groups wherein methyl comprises 
about 20 to 80 percent by weight of the R*** group. 
The amount of activating cocatalyst and metallocene catalyst usefully 
employed in preparation of the catalyst composition, whether the catalyst 
composition is formed in situ as it is being introduced into the reaction 
zone or formed prior to introduction into the reaction zone, can vary over 
a wide range. When the cocatalyst is a branched or cyclic oligomeric 
poly(hydrocarbylaluminum oxide), the mole ratio of aluminum atoms 
contained in the poly(hydrocarbylaluminum oxide) to metal atoms contained 
in the metallocene catalyst is generally in the range of from about 2:1 to 
about 100,000:1, preferably in the range of from about 10:1 to about 
10,000:1, and most preferably in the range of from about 50:1 to about 
2,000:1. When the cocatalyst is an ionic salt of the formula [A.sup.+ 
][BR*.sub.4.sup.- ] or a boron alkyl of the formula BR*.sub.3, the mole 
ratio of boron atoms contained in the ionic salt or the boron alkyl to 
metal atoms contained in the metallocene catalyst is generally in the 
range of from about 0.5:1 to about 10:1, preferably in the range of from 
about 1:1 to about 5:1. 
The catalyst can be composed of one or more of metal compounds in 
combination with one or more co-catalysts. Alternatively, all or a portion 
of the co-catalyst can be fed separately from the metal compound(s) to the 
reactor. Promoters associated with any particularly polymerization are 
usually added to the reactor separately from the co-catalyst and/or metal 
compound(s). 
Unsupported Catalyst 
The unsupported metallocene(s) for use herein are generally in a liquid 
form. As used herein, "liquid catalyst" or "liquid form" includes, neat, 
solution, emulsion, colloids, suspension and dispersions of the transition 
metal or rare earth metal component(s) of the catalyst. 
If the metal compound and/or the co-catalyst occurs naturally in liquid 
form, it can be introduced "neat" into the reactor. More likely, the 
liquid catalyst is introduced into the reactor as a solution (single 
phase, or "true solution" using a solvent to dissolve the metal compound 
and/or co-catalyst), an emulsion (partially dissolving the catalyst 
components in a solvent), suspension, dispersion, or slurry (each having 
at least two phases). Preferably, the unsupported catalyst employed is a 
solution or an emulsion, most preferably a solution. 
The solvents which can be utilized to form liquid catalysts are inert 
solvents, preferably non-functional hydrocarbon solvents, and may include 
aliphatic hydrocarbons such as butane, isobutane, ethane, propane, 
pentane, isopentane, hexane, heptane, octane, decane, dodecane, 
hexadecane, octadecane, and the like; alicyclic hydrocarbons such as 
cyclopentane, methylcyclopentane, cyclohexane, cycloctane, norbornane, 
ethylcyclohexane and the like; aromatic hydrocarbons such as benzene, 
toluene, ethylbenzene, propylbenzene, butylbenzene, xylene, 
tetrahydrofuran and the like; petroleum fractions such as gasoline, 
kerosene, light oils, and the like; and mineral oil. Likewise, halogenated 
hydrocarbons such as methylene chloride, chlorobenzene, 
ortho-chlorotoluene and the like may also be utilized. By "inert" is meant 
that the material being referred to is non-deactivating in the 
polymerization reaction zone under the conditions of gas phase 
polymerization and is non-deactivating with the catalyst in or out of the 
reaction zone. By "non-functional", it is meant that the solvents do not 
contain groups such as strong polar groups which can deactivate the active 
catalyst metal sites. 
The concentration of the catalyst and/or co-catalyst that is in solution 
that is provided to the reactor may be as high as the saturation point of 
the particular solvent being used. Preferably, the concentration is in the 
range of from about 0.01 to about 10,000 millimoles/liter. Of course, if 
the catalyst and/or co-catalyst is being used in its neat form, i.e., in 
its liquid state with no solvent, it will be: comprised of essentially 
pure catalyst and/or co-catalyst, respectively. Liquid flowrates of 
catalyst, cocatalyst, and activators range between 5 and 250 kg/hr for 
commercial scale gas-phase reactors. 
Supporting the Catalyst 
The supported metallocene catalyst(s) may be of the type that is naturally 
supported or artificially supported. Naturally supported catalysts are 
those which employ an aluminoxane as a morphology template. Neat MAO is a 
solid at room temperature and when it is prepared with controlled 
morphology, it can be used as a natural support for a metallocene 
catalyst. Two methods by which the morphology of MAO can be controlled are 
by removing the solvent by a technique such as spray drying, as described 
by Union Carbide in EP 668295 or precipitated from solution as described 
U.S. Pat. Nos. 4,952,540 and 4,923,833. 
As to the artificially supported catalysts, said support may be any of 
those known in the art. Examples of such support systems are inorganic 
oxides (silica, alumina, mixtures thereof, mixtures thereof with Ti, Mg, 
Zr, etc.), finely divided polyolefins, and porous polymer systems, such as 
polystyrene. High surface area silica may be used. In most cases, said 
materials should be thoroughly dried before contact with the catalyst. 
Said contact is preferably done in the presence of a solvent (e.g., 
isopentane, heptane, decane, toluene, benzene, and xylene) and at room 
temperature so as not to deactivate the catalyst. The solvent is removed 
at reduced pressure. 
Supported metallocenes are disclosed in PCT WO 94/28034 published Dec. 8, 
1994 and in U.S. Pat. No. 5,332,706, which are incorporated herein by 
reference. 
Additional Catalysts 
In addition to the supported and unsupported metallocenes, other catalyst 
may be added to the system to provide for different product properties. 
Examples of suitable catalysts include: 
A. Ziegler-Natta catalysts, including titanium based catalysts such as 
those described in U.S. Pat. Nos. 4,376,062 and 4,379,758. Ziegler-Natta 
catalysts are typically are magnesium/titanium/electron donor complexes 
used in conjunction with an organoaluminum cocatalyst. 
B. Chromium based catalysts such as those described in U.S. Pat. Nos. 
3,709,853; 3,709,954; and 4,077,904. 
C. Vanadium based catalysts such as vanadium oxychloride and vanadium 
acetylacetonate, such as described in U.S. Pat. No. 5,317,036. 
D. Cationic forms of metal halides, such as aluminum trihalides. 
E. Cobalt catalysts and mixtures thereof such as those described in U.S. 
Pat. Nos. 4,472,559 and 4,182,814. 
F. Nickel catalysts and mixtures thereof such as those described in U.S. 
Pat. Nos. 4,155,880 and 4,102,817. 
G. Rare Earth metal catalysts, i.e., those containing a metal having an 
atomic number in the Periodic Table of 57 to 103, such as compounds of 
cerium, lanthanum, praseodymium, gadolinium and neodymium. Especially 
useful are carboxylates, alcoholates, acetylacetonates, halides (including 
ether and alcohol complexes of neodymium trichloride), and allyl 
derivatives of such metals. Neodymium compounds, particularly neodymium 
neodecanoate, octanoate, and versatate, are the most preferred rare earth 
metal catalysts. 
Polymers 
Illustrative of the polymers which can be produced herein are the 
following: ethylene homopolymers and ethylene copolymers employing one or 
more C.sub.3 -C.sub.12 alpha olefins; propylene homopolymers and propylene 
copolymers employing one or more alpha olefins selected from the group 
C.sub.2, C.sub.4 -C.sub.12 ; propylene copolymers employing one or more 
.alpha.-.omega. diolefins selected from the group C.sub.5 -C.sub.12 (e.g., 
ethylene norbordiene); 1-butene homopolymers and 1-butene copolymers 
employing one or more alpha olefins selected from the group C.sub.2, 
C.sub.3, C.sub.5 -C.sub.12; 1 -butene copolymers employing one or more 
.alpha.-.omega. diolefins selected from the group C.sub.5 -C.sub.12 ; 
4-methyl-1-pentene homopolymers and 4-methyl-1-pentene copolymers 
employing one or more alpha olefins selected from the group C.sub.2 
-C.sub.12 ; 4-methyl-1-pentene copolymers employing one or more 
.alpha.-.omega. diolefins selected from the group C.sub.5 -C.sub.12 ; 
polyisoprene; polystyrene; polybutadiene; polymers of butadiene 
copolymerized with styrene; polymers of butadiene copolymerized with 
acrylonitrile; polymers of isobutylene copolymerized with isoprene; 
ethylene propylene rubbers and ethylene propylene diene rubbers; 
polychloroprene, and the like. 
Polymerization 
The present invention is not limited to any specific type of polymerization 
and may include gas phase, slurry, solution, bulk, and similar types of 
polymerization. Gas phase polymerization is preferable, especially one 
carried out in a stirred or fluidized bed reactor. The invention can be 
carried out in a single reactor or multiple reactors (two or more reactors 
in series), with catalysts being added to one or more of these reactors. 
However, this invention is thought to be most useful in the manufacture of 
two polymers in a single reactor. In addition to well known conventional 
gas phase polymerization processes, "condensed mode", including the 
so-called "induced condensed mode", and "liquid monomer" operation of a 
gas phase polymerization can be employed. 
A conventional fluidized bed process for producing resins is practiced by 
passing a gaseous stream containing one or more monomers continuously 
through a fluidized bed reactor under reactive conditions in the presence 
of a polymerization catalyst. Product is withdrawn from the reactor. A 
gaseous stream of unreacted monomer is withdrawn from the reactor 
continuously and recycled into the reactor along with make-up monomer 
added to the recycle stream. 
Condensed mode polymerization is disclosed in U.S. Pat. Nos. 4,543,399; 
4,588,790; 5,352,749; and 5,462,999. Condensing mode processes are 
employed to achieve higher cooling capacities and, hence, higher reactor 
productivity. In these polymerizations a recycle stream, or a portion 
thereof, can be cooled to a temperature below the dew point in a fluidized 
bed polymerization process, resulting in condensing all or a portion of 
the recycle stream. The recycle stream is returned to the reactor. The dew 
point of the recycle stream can be increased by increasing the operating 
pressure of the reaction/recycle system and/or increasing the percentage 
of condensable fluids and decreasing the percentage of non-condensable 
gases in the recycle stream. The condensable fluid may be inert to the 
catalyst, reactants and the polymer product produced; it may also include 
monomers and comonomers, including the monomer to be polymerized. The 
condensing fluid can be introduced into the reaction/recycle system at any 
point in the system. Condensable fluids include saturated or unsaturated 
hydrocarbons. In addition condensable fluids of the polymerization process 
itself other condensable fluids, inert to the polymerization can be 
introduce to "induce" condensing mode operation. Examples of suitable 
condensable fluids may be selected from liquid saturated hydrocarbons 
containing 2 to 8 carbon atoms (e.g., propane, n-butane, isobutane, 
n-pentane, isopentane, neopentane, n-hexane, isohexane, and other 
saturated C.sub.6 hydrocarbons, n-heptane, n-octane and other saturated 
C.sub.7 and C.sub.8 hydrocarbons, and mixtures thereof). Condensable 
fluids may also include polymerizable condensable monomers such as 
olefins, alpha-olefins, diolefins, diolefins containing at least one alpha 
olefin, and mixtures thereof In condensing mode, it desirable that the 
liquid entering the fluidized bed be dispersed and vaporized quickly. 
Liquid monomer polymerization mode is disclosed, in U.S. Pat. No. 
5,453,471, U.S. Ser. No. 510,375, now U.S. Pat. No. 5,834,571, PCT 
95/09826 (US) and PCT 95/09827 (US). When operating in the liquid monomer 
mode, liquid can be present throughout the entire polymer bed provided 
that the liquid monomer present in the bed is adsorbed on or absorbed in 
solid particulate matter present in the bed, such as polymer being 
produced or fluidization aids (e.g., carbon black) present in the bed, so 
long as there is no substantial amount of free liquid monomer present more 
than a short distance above the point of entry into the polymerization 
zone. Liquid mode makes it possible to produce polymers in a gas phase 
reactor using monomers having condensation temperatures much higher than 
the temperatures at which conventional polyolefins are produced. In 
general, liquid monomer process are conducted in a stirred bed or gas 
fluidized bed reaction vessel having a polymerization zone containing a 
bed of growing polymer particles. The process comprises continuously 
introducing a stream of one or more monomers and optionally one or more 
inert gases or liquids into the polymerization zone; continuously or 
intermittently introducing a polymerization catalyst into the 
polymerization zone; continuously or intermittently withdrawing polymer 
product from the polymerization zone; and continuously withdrawing 
unreacted gases from the zone; compressing and cooling the gases while 
maintaining the temperature within the zone below the dew point of at 
least one monomer present in the zone. If there is only one monomer 
present in the gas-liquid stream, there is also present at least one inert 
gas. Typically, the temperature within the zone and the velocity of gases 
passing through the zone are such that essentially no liquid is present in 
the polymerization zone that is not adsorbed on or absorbed in solid 
particulate matter. 
In a preferred embodiment of the present invention, the liquid catalyst in 
a carrier gas (e.g., nitrogen, argon, alkane, or mixtures thereof) is 
surrounded by at least one gas which serves to move or deflect resin 
particles of the bed out of the path of the liquid catalyst as it enters 
the fluidization zone and away from the area of catalyst entry, thereby 
providing a particle lean zone. The first or particle-deflecting gas can 
be selected from the group consisting of recycle gas, monomer gas, chain 
transfer gas (e.g., hydrogen), inert gas or mixtures thereo. Preferably 
the particle-deflecting gas is all or a portion of recycle gas and the 
tip-cleaning gas is all or a portion of a monomer (e.g., ethylene or 
propylene) employed in the process. 
Catalyst Feeding 
The supported and unsupported catalysts may be fed as a mixture to the 
reactor or separately. The catalyst may be fed in a preactivated or 
prepolymerized form. One catalyst may be prepolymerized and/or 
preactivated and the other not, as desired. 
In a preferable embodiment, especially in a continuous (non-batch) process, 
initially the supported catalyst is fed to the reactor to form a stable 
polymer bed in the reactor. Once the reactor bed has been stabilized, 
typically in about 5 to about 300 minutes, depending upon the reactor 
size, then the higher activity unsupported catalyst may be fed. This type 
of feeding, especially to a continuous gas phase reactor system, allows 
for obtaining the advantage of the activity of tile unsupported catalyst, 
but achieving the operating stability of the supported catalyst system. 
The unsupported catalyst is preferably fed to the reactor with the aid of a 
gas, either combined prior to injection or preferably with an effervescent 
or perpendicular spray nozzle. Gases for use may be any relatively inert 
to the catalyst so that there is not blockage in the catalyst nozzle. 
Exemplary gases include N.sub.2, Ar, He, CH.sub.4, C.sub.2 H.sub.6, 
C.sub.3 H.sub.8, CO.sub.2, H.sub.2, cycle gas. The gas may be under 
supercritical fluid conditions. Reactive gases (e.g., olefins) may be used 
if the catalyst is activated in the reactor, e.g., the cocatalyst is fed 
separately. The gas flow rates in the nozzle should be between about 5 and 
200 kg/hr., depending upon the reactor size and particle size control as 
discussed above. 
Other Material 
Non-catalytic liquids may also be delivered to the reactor, e.g., solvents, 
anti-fouling agents, scavengers, monomers, antistatic agent,w;, secondary 
alkyls, stabilizers or antioxidants. Some specific examples include 
methanol, veratrole, propylene oxide, glyme, 1,2 dimethoxypropane, water, 
ATMER-163 antistat agent (ICI Chemicals), hydrogen, metal alkyls of the 
general formula M.sup.3 R.sup.5 g, where M.sup.3 is a Group IA, IIA or 
IIIA metal, R.sup.5 is an alkyl or aryl, and g is 1, 2, or 3; zinc alkyls, 
CHCl.sub.3, CFCl.sub.3, CH.sub.3 CCl.sub.3, CF.sub.2 ClCCl.sub.3, 
ethyltrichloroacetate, aluminum alkyls, most preferably 
triisobutylaluminum. The gas in such situations may be the cycle gas in a 
gas phase reactor that is operating in condensing mode or may be another 
inert gas, as is used with the delivery of the catalyst. The addition of 
this liquid can be any where to the reaction system, e.g., to the bed, 
beneath the bed, above the bed or to the cycle line. The use of these 
additives is well within the skill of those skilled in the art. These 
additives may be added to the reaction zone separately or independently 
from the liquid catalyst if they are solids, or as part of the catalyst 
provided they do not interfere with the desired atomization. To be part of 
the catalyst solution, the additives should be liquids or capable of being 
dissolved in the catalyst solution. 
Specific Uses 
Examples of the use of this invention would be as follows: 
Catalyst "A" (unsupported) and Catalyst "A" (supported) wherry both 
catalysts are the same. This combination will give the narrow molecular 
weight distribution (MWD) of Mw/Mn (weight average molecular weight to 
number average molecular weight) of about 2 to about 4 and the molecular 
homogeneity expected from metallocene catalysts, but with better control 
of the polymerization process. 
Catalyst "B" (unsupported) and catalyst "C" (supported), where high melt 
flow polymer is made by catalyst "C" and low melt flow polymer is made by 
catalyst "B". The use of unsupported catalyst to polymerize the low melt 
flow polymer leads to good dispersion of the low melt flow polymer in the 
nascent powder. This allows ready manufacture of broad MWD (Mw/Mn of about 
5 to about 100) polymer without the use of a high shear downstream 
compounding step to mix polymers having widely different melt flows. 
Catalyst "D" (unsupported) and catalyst "E" (supported), where the polymer 
made by catalyst "E" contains some amount of stereo-irregular material. 
The intermingling of the molecules made by catalyst "D" and by catalyst 
"E" reduces the stickiness (as defined in U.S. Pat. No. 4,994,534, which 
is incorporated herein by reference) of the resulting powder. 
Catalyst "F" (unsupported) and catalyst "G" (supported), where the 
copolymer made by catalyst "G" has less random distribution of comonomer 
units than does the copolymer made by catalyst "F". This provides, in the 
case of low comonomer content random copolymers, enhanced physical 
properties coupled with good heat sealing performance. 
Catalyst "H" (unsupported) and catalyst "I" (supported), in a series of 
reactors in which a homopolymer phase is made in a first reactor and an 
ethylene-propylene rubber in the second reactor wherein the rubber has two 
different ethylene-propylene polymers with different xylene solubles. The 
copolymer made by catalyst "H" has less random distribution of comonomer 
units than does the copolymer made by catalyst "I". This provides, in the 
case of "impact" copolymers, superior impact stiffness balance, similar to 
those obtained by the more expensive process of using blends of EPR and PE 
as the rubber phase of an impact copolymer. The intimate mixing of 
catalyst sites that takes place in the first reactor provides advantages 
for the in-situ dispersion of rubber that takes place in the "rubber" 
reactor.

EXAMPLES 
Mixed catalyst systems of a supported catalyst and a solution catalyst were 
fed to a slurry phase autoclave and used to polymerize ethylene with a 
minor amount of hexene. The examples are set forth in Table 1 below. The 
fourth column is the molar ratio between the two catalysts. The fifth 
column is a molar ratio. MAO is methyl alumoxane. The activity is measured 
in gm PE/per millimole Zr per hour per hundred psi of ethylene. The Mw and 
PDI (polydispersity index) were measured by Size Exclusion Chromatography 
at 140.degree. C., Method A, using a cross-linked polystyrene column set 
provides for Mw separation covering a daltons range of 200 to 10,000,000 
with 1,2,4-trichlorobenzene as carrier solvent. 
The liquid catalyst was BuCpZ (bis(n-butyl cyclopentdienyl) zirconium 
dichloride) or SIZR-2 (dimethyl silyl bis(2-methyl indenyl) zirconium 
dichloride). These catalysts were used in a hydrocarbon solution. 
SIZR-2/BuCpZ was a physical mixture of the two catalysts. The supported 
catalysts were S-1 (BuCpZ supported on a silica carrier) and S-2 (SIZR-2 
supported on a silica carrier). The MAO was on the support with the 
catalyst (about 0.6 mmol/gm silica). The silica was Davison 955-600. 
The results show some of the benefits of the present invention. As compared 
to the unsupported BuCpZ, higher molecular weight polymer could be made 
with the present invention (runs 3 and 4), but at a higher activity than 
supported BuCpZ. These runs show how to control catalyst activity as well. 
The second four runs show that the present invention (runs 7 and 8) may be 
used to control PDI and Mw of polymers. 
TABLE 1 
__________________________________________________________________________ 
Run 
Unsupported 
Supported 
Soln/ 
Cocat/ 
H.sub.2 
C.sub.6 
No. Catalyst Catalyst Supt Zr (ml) (ml) Activity Mw PDI 
__________________________________________________________________________ 
1 BuCpZ 0 20 44302 
108519 
2.1 
2 BuCpZ 750 0 20 71358 26956 2.7 
3 BuCpZ BuCpZ 0.5 750 0 20 59327 39780 2.5 
4 BuCpZ BuCpZ 1 750 0 20 66867 28111 2.1 
5 SIZR-2/BuCpZ 120 20 46139 66061 2.7 
6 SIZR-2/BuCpZ 1500 120 20 56277 86905 8.5 
7 SIZR-2 BuCpZ 1 400 120 20 56326 53750 3.7 
8 BuCpZ SIZR-2 1 400 120 20 53271 59162 6.4 
__________________________________________________________________________