Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-03-31
2002-07-23
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...
C526S141000, C526S161000, C526S172000, C526S352000, C502S155000, C556S021000, C556S028000
Reexamination Certificate
active
06423794
ABSTRACT:
FIELD OF THE INVENTION
Transition metal complexes of selected bidentate ligands containing both phosphorous and nitrogen groups which coordinate to certain early and late transition metals are active catalysts (sometimes in the presence of other compounds) for the polymerization of ethylene. Polyethylenes prepared by some of these catalysts under certain conditions are novel, being highly branched and apparently having exceptionally stiff polymer chains in solution.
TECHNICAL BACKGROUND
Polyethylenes are very important items of commerce, large quantities of various grades of these polymers being produced annually for a large number of uses, such as packaging films and moldings. There are many different methods for making such polymers, including many used commercially, such as free radical polymerization to make low density polyethylene, and many so-called coordination catalysts such as Ziegler-Natta-type and metallocene-type catalysts. Each of these catalyst systems has its advantages and disadvantages, including cost of the polymerization and the particular structure of the polyethylene produced. Due to the importance of polyethylenes, new catalyst systems which are economical and/or produce new types of polyethylenes are constantly being sought.
WO98/40420 describes the use of certain late transition metal complexes of ligands containing phosphorous and nitrogen as ingredients in polymerization systems for olefins. Many of the ligands disclosed herein are different from those disclosed in this reference.
WO97/48735 generally describes the use of certain complexes of late transition metals are polymerizations catalysts for olefins. Among the ligands in these complexes are those which contain both phosphorous and nitrogen. None of the ligands described herein are specifically described in this reference.
Linear polyethylene is reported (J. Brandrup, et al., Ed.,
Polymer Handbook
, 3
rd
Ed., John Wiley & Sons, New York, 1989, p. VII/6) to have a Mark-Houwink constant (&agr;) of about 0.6-0.7 in 1,2,4-trichlorobezene at 135° C. No mention is made of any polyethylenes with higher Mark-Houwink constants.
SUMMARY OF THE INVENTION
This invention concerns a first process for the production of polyethylene, comprising the step of contacting, at a temperature of about −100° C. to about +200° C., ethylene and a Ti, Cr, V, Zr, Hf or Ni complex of a ligand of the formula
wherein:
T is hydrocarbylene, substituted hydrocarbylene or —CR
9
R
10
—;
R
2
is hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
3
and R
4
are each independently hydrocabyl or substituted hydrocarbyl, provided that a carbon atom bound to a nitrogen atom has at least two other carbon atoms bound to it;
R
5
and R
6
are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
7
and R
8
are each independently hydrocarbyl or substituted hydrocarbyl, provided that a carbon atom bound to a phosphorous atom has at least two other carbon atoms bound to it;
R
9
and R
10
are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
11
and R
12
are each independently hydrocarbyl or substituted hydrocarbyl;
R
13
is hydrocarbyl or substituted hydrocarbyl; and provided that R
2
and R
9
taken together may form a ring.
Also disclosed herein is a second process for the production of polyethylene, comprising the step of contacting, at a temperature of about −100° C. to about +200° C., ethylene, a compound of the formula
and:
(a) a first compound W, which is a neutral Lewis acid capable of abstracting X
−
and alkyl group or a hydride group from M to form WX
−
, (WR
20
)
−
or WH
−
and which is also capable of transferring an alkyl group or a hydride to M, provided that WX
−
is a weakly coordinating anion; or
(b) a combination of second compound which is capable of transferring an alkyl or hydride group to M and a third compound which is a neutral Lewis acid which is capable of abstracting X
−
, a hydride or an alkyl group from M to form a weakly coordinating anion;
wherein:
M is Ti, Cr, V, Zr, Hf or Ni; each X is an anion;
n is an integer so that the total number of negative charges on said anion or anions is equal to the oxidation sate of M;
T is hydrocarbylene, substituted hydrocarbylene or —CR
9
R
10
—;
R
2
is hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
3
and R
4
are each independently hydrocarbyl or substituted hydrocarbyl, provided that a carbon atom bound to a nitrogen atom has at least two other carbon atoms bound to it;
R
5
and R
6
are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
7
and R
8
are each independently hydrocarbyl or substituted hydrocarbyl, provided that a carbon atom bound to a phosphorous atom has at least two other carbon atoms bound to it;
R
9
and R
10
are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
11
and R
12
are each independently hydrocarbyl or substituted hydrocarbyl;
R
13
is hydrocarbyl or substituted hydrocarbyl; and provided that R
2
and R
9
taken together may form a ring.
This invention also concerns a third process for the production of polyethylene, comprising the step of contacting, at a temperature of about −100° C. to about +200° C., ethylene and a compound of the formula
wherein:
M is Ti, Cr, V, Zr, Hf or Ni;
n is an integer so that the total number of negative charges on said anion or anions is equal to the oxidation sate of M;
T is hydrocarbylene, substituted hydrocarbylene or —CR
9
R
10
—;
R
2
is hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
3
and R
4
are each independently hydrocabyl or substituted hydrocarbyl, provided that a carbon atom bound to a nitrogen atom has at least two other carbon atoms bound to it;
R
5
and R
6
are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
7
and R
8
are each independently hydrocarbyl or substituted hydrocarbyl, provided that a carbon atom bound to a phosphorous atom has at least two other carbon atoms bound to it;
R
9
and R
10
are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
11
and R
12
are each independently hydrocarbyl or substituted hydrocarbyl;
R
13
is hydrocarbyl or substituted hydrocarbyl;
Z
1
is hydride or alkyl or any other anionic ligand into which ethylene can insert;
Y is a neutral ligand capable of being displaced by ethylene or a vacant coordination site;
Q is a relatively non-coordinating anion;
P is a divalent polyethylene group containing one or more ethylene units; and
Z
2
is an end group and provided that R
2
and R
9
taken together may form a ring.
This invention also concerns a homopolyethylene which has a Mark-Houwink constant of about 1.0 or more when measured in 1,2,4-trichlorobenzene.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A structure drawn such as (V),
simply means that the ligand in the square bracket is coordinated to the metal containing moiety, as indicated by the arrow. Nothing is implied about what atoms in the ligand are coordinated to the metal.
Herein, certain terms are used. Some of them are:
A “hydrocarbyl group” is a univalent group containing only carbon and hydrogen. If not otherwise stated, it is preferred that hydrocarbyl groups herein contain 1 to about 30 carbon atoms.
By “substituted hydrocarbyl” herein is meant a hydrocarbyl group which contains one or more substituent groups which are inert under the process conditions to which the compound containing these groups is subjected. The substituent groups also do not substantially interfere with the process. If not otherwise stated, it is preferred that substituted hydrocarbyl groups herein contain 1 to about 30 carbon atoms. Included in the meaning of “substituted” are heteroaromatic rings.
By “(inert) functional group” herein is meant a group other than hydrocarbyl or substituted hydrocarbyl which is inert under the process conditions to which the compound containing the group is subjected. The functional groups also do not substantially interfere with any process described herein that the compound
E. I. du Pont de Nemours and Company
Harlan R.
Wu David W.
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