Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-10-13
2002-11-26
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S118000, C526S124200, C526S124300, C526S124900, C502S104000, C502S110000, C502S111000, C502S115000, C502S126000, C502S129000, C502S133000
Reexamination Certificate
active
06486274
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to catalysts, to methods of making catalysts, to methods of using catalysts, to methods of polymerizing, and to polymers made with such catalysts. In another aspect, the present invention relates to polyolefin catalysts, to methods of making such catalysts, to methods of using such catalysts, to polyolefin polymerization, and to polyolefins. In even another aspect, the present invention relates to Ziegler-Natta catalysts, to methods of making such catalysts, to methods of using such catalysts, to polyolefin polymerization, and to polyolefins.
2. Description of the Related Art
Having been around since the early 1950's, Ziegler-type polyolefin catalysts, their general methods of making, and subsequent use, are well known in the polymerization art.
However, while much is known about Ziegler-type catalysts, there is a constant search for improvements in their polymer yield, catalyst life, catalyst activity, and in their ability to produce polyolefins having certain properties.
U.S. Pat. No. 4,255,544, issued Mar. 10, 1981 to Kimura et al., discloses a process for polymerization of ethylene utilizing a catalyst comprising (A) the reaction product of a magnesium compound and titanium halide, and (B) an organic aluminum compound, wherein Component A is prepared by reacting magnesium dialkoxide with a hologen-containing silicon compound and an alcohol to provide a solid material and then reacting the solid material with titanium halide in the presence of an alkoxy-containing silicon compound.
U.S. Pat. No. 4,914,069, issued Apr. 3, 1990 to Job et al., discloses the preparation of an olefin polymerization catalyst component having improved activity and selectivity, which are prepared by (a) halogenating a magnesium compound containing at least one aryloxy, alkyl or carbonate or alkloxy group with a first halide of tetravalent titanium and a first electron donor; (b) contacting the resulting product with a second halide of tetravalent titanium; and (c) washing a resulting treated halogenated product with an inert hydrocarbon liquid. In the process, a second electron donor is used in step (a) or (b), and that the product of step (b) is contacted in a step (b2) with a third halide of tetravalent titanium at a temperature of 40° C. to 140° C. and thereafter the treated product is washed in step (c).
U.S. Pat. No. 5,155,187, issued Oct. 13, 1992 to Shelly, discloses a polymerization method utilizing a catalyst which is the reaction product generally of a silicon-containing compound, a magnesiumdialkyl, an alcohol, a halide-containing metal compound, an aluminum alkoxide, and a second halide-containing metal compound.
U.S. Pat. No. 5,610,246, issued Mar. 11, 1997 to Buehler et al., discloses a process for polymerizing propylene using a silica-supported catalyst. The catalyst comprises the product obtained by contacting silica, in random order, with (1) at least one hydrocarbon soluble magnesium-containing compound; and (2) a first modifying compound selected from the group consisting of silicon halides, boron halides, aluminum halides and mixtures thereof followed by a second specified modifying compound.
U.S. Pat. No. 5,631,334, issued May 20, 1997 to Zandona, disclose a process for the manufacture of a catalytic solid for the (co)polymerization of at least one olefin, comprising the coprecipitate magnesium and of at least one transition metal.
However, in spite of these advancements in the prior art, none of these prior art references disclose or suggest that the nature of R in a mixture of TiCl
4
/Ti(O
i
R)
4
will provide a catalyst having improved hydrogen response which can provide polyolefins having narrower molecular weight distribution (“MWD”).
Thus, there is a need in the art for a polyolefin catalyst.
There is another need in the art for a method of making a polyolefin catalyst.
There is even another need in the art for a method of polymerizing olefins.
There is still another need in the art for polyolefins of narrower MWD.
There is yet another need in the art for a catalyst having improved hydrogen response.
There is even still another need in the art for a method of making a polyolefin catalyst that provides polymers having a narrow molecular weight distribution wherein the method comprises using a mixture of TiCl
4
/Ti(O
i
Pr)
4
.
There is even yet another need in the art for a method of making polyolefins of narrower MWD.
These and other needs in the art will become apparent to those of skill in the art upon review of this specification, including its claims.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide for a polyolefin catalyst.
It is another object of the present invention to provide for a method of making a polyolefin catalyst.
It is even another object of the present invention to provide for a method of polymerizing olefins.
It is still another object of the present invention to provide for polyolefins of narrower MWD.
It is yet another object of the present invention to provide a catalyst having improved hydrogen response.
It is even still another object of the present invention to provide for a method of making a polyolefin catalyst that provides polymers having a narrow molecular weight distribution wherein the method comprises using a mixture of TiCl
4
/Ti(O
i
Pr)
4
.
It is even yet another object of the present invention to provide a method of making polyolefins of narrower MWD.
One embodiment of the present invention provides a catalyst component produced by a process generally comprising: a) contacting a soluble magnesium dialkoxide compound of the general formula Mg(OR″)
2
with a halogenating agent capable of exchanging one halogen for one alkoxide to form a reaction product A, where R″ is a hydrocarbyl or substituted hydrocarbyl having from 1 to 20 carbon atoms; b) contacting reaction product A with a first halogenating/titanating agent to form reaction product B; and c) contacting reaction product B with a second halogenating/titanating agent to form a catalyst component. Preferably, the first halogenating/titanating is a blend of Ti(OPr)
4
/TiCl
4
. The soluble magnesium dialkoxide compound is a reaction product of a reaction comprising an alkyl magnesium compound of the general formula MgRR′, wherein R and R′ are alkyl groups of 1-10 carbon atoms and may be the same or different, and an alcohol of the general formula R″OH wherein the alcohol is linear or branched and wherein R″ is an alkyl group of 4-20 carbon atoms.
Another embodiment of the present invention provides a catalyst. Generally, the catalyst is produced by a process comprising contacting a catalyst component of the invention together with an organoaluminum preactivating agent. The catalyst component is generally produced by a process comprising, i) contacting a magnesium dialkoxide compound of the general formula Mg(OR″)
2
with a halogenating agent capable of exchanging one halogen for one alkoxide to form a reaction product A, where R″ is a hydrocarbyl or substituted hydrocarbyl having from 1 to 20 carbon atoms; ii) contacting reaction product A with a first halogenating/titanating agent to form reaction product B; and iii) contacting reaction product B with a second halogenating/titanating agent. Preferably the first halogenating/titanating agent is a blend of Ti(OPr)
4
/TiCl
4
. The catalyst of the present invention has an improved hydrogen response and is useful in producing a polymer of a desired molecular weight distribution.
Even another embodiment of the present invention provides a polymer produced by a process comprising a) contacting one or more &agr;-olefin monomers together in the presence of a catalyst of the invention under polymerization conditions. Preferably the catalyst is used to polymerize polyethylene monomers to produce polyethylene polymers. The catalyst is generally produced by a process comprising: i) contacting a soluble magnesium dialkoxide compound of the general formula Mg(OR)
2
with a halogenating
Coffy Tim J.
Gray Steven D.
Fina Technology, Inc.
Gilbreth & Associates
Rabago R.
Wu David W.
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