Molecular weight control in olefin polymerization

Details Molecular weight control in olefin polymerization Molecular weight control in olefin polymerization

1999-05-24

2002-04-16

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...

C526S128000, C526S144000, C526S161000, C526S169100, C526S171000, C526S172000, C526S901000, C526S905000, C526S135000

Reexamination Certificate

active

06372869

ABSTRACT:

FIELD OF THE INVENTION
In olefin polymerizations in which late transition metal complexes of selected ligands, such as &agr;-diimines, are used as polymerization catalysts, various compounds, such as hydrogen or selected silanes, may be used as chain transfer agents to reduce polyolefin molecular weight.
TECHNICAL BACKGROUND
Polymerization of olefins using early transition metal containing catalysts such as vanadium and zirconium is a well known and commercially important technology. In many instances it is desirable to lower the molecular weight of the polyolefin that would normally be produced. For example lower molecular weight polymers are usually considered easier to melt process, since they have lower melt viscosities. While polymerization process conditions can sometimes be altered to change the molecular weight of the resulting olefin, often a chain transfer agent such as hydrogen is deliberately added to the process to lower the polyolefin molecular weight.
The polymerization of olefins using late transition metal containing catalysts such as nickel with selected bidentate ligands is known, see for instance U.S. Pat. No. 5,714,556, World Patent Application 96/23010, and U.S. patent application Ser. No. 09/006,536, filed Jan. 13, 1998, now U.S. Pat. No. 6,174,975 (World Patent Application 98/30609). However, methods for lowering the molecular weight of polyolefins produced in such processes are not well known. Since these processes often give polyolefins with unique and valuable structures, methods for controlling the polymer molecular weight are desirable.
SUMMARY OF THE INVENTION
This invention concerns, a process for the polymerization of a polymerizable olefin using as a polymerization catalyst a complex of a bidentate ligand of a metal selected from the group consisting of nickel, iron, and cobalt, wherein the improvement comprises, using as a chain transfer agent an effective amount of hydrogen, CBr
4
or a compound of the formula R
1
R
2
R
3
SiH, wherein R
1
is alkyl containing 2 or more carbon atoms, R
2
is alkyl, and R is hydrogen or alkyl.
This invention also concerns a process for the polymerization of one or more polymerizable olefins, comprising, contacting:
(a) one or more polymerizable olefins;
(b) an effective amount of a chain transfer agent selected from the group consisting of hydrogen, CBr
4
and a compound of the formula R
1
R
2
R
3
SiH, wherein R
1
is alkyl, R
2
is alkyl, and R
3
is hydrogen or alkyl;
(c) an active polymerization catalyst which contains a nickel complex of a ligand of the formula
or a compound of the formula
 wherein:
Ar
1
is an aromatic moiety with n free valencies, or diphenylmethyl;
each Q is —NR
52
R
53
or —CR
54
═NR
55
;
p is 1 or 2;
E is 2-thienyl or 2-furyl;
each R
52
is independently hydrogen, benzyl, substituted benzyl, phenyl or substituted phenyl;
each R
54
is independently hydrogen or hydrocarbyl; and
each R
55
is independently a monovalent aromatic moiety;
m is 1, 2 or 3;
R
53
is hydrogen or alkyl;
each R
16
and R
17
is independently hydrogen or acyl containing 1 to 20 carbon atoms;
each R
33
, R
34
, R
35
, and R
36
is independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
each R
31
is independently hydrocarbyl or substituted hydrocarbyl containing 2 or more carbon atoms;
each R
32
is independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
Ar
2
is an aryl moiety;
R
38
, R
39
, and R
40
are each independently hydrogen, hydrocarbyl, substituted hydrocarbyl or an inert functional group;
R
37
and R
41
are each independently hydrocarbyl, substituted hydrocarbyl or an inert functional group whose E
s
is about −0.4 or less;
Ar
3
is an aryl moiety;
R
45
and R
46
are each independently hydrogen or hydrocarbyl;
Ar
4
is an aryl moiety;
Ar
5
and Ar
6
are each independently hydrocarbyl;
Ar
7
and Ar
8
are each independently an aryl moiety;
Ar
9
and Ar
10
are each independently an aryl moiety or —CO
2
R
56
, wherein R
56
is alkyl containing 1 to 20 carbon atoms;
Ar
11
is an aryl moiety;
R
50
is hydrogen or hydrocarbyl;
R
51
is hydrocarbyl or —C(O)—NR
50
—Ar
11
;
R
44
is aryl;
R
47
and R
48
are each independently phenyl groups substituted by one or more alkoxy groups, each alkoxy group containing 1 to 20 carbon atoms;
R
49
is alkyl containing 1 to 20 carbon atoms, or an aryl moiety;
R
13
and R
16
are each independently hydrocarbyl or substituted hydrocarbyl, provided that the carbon atom bound to the imino nitrogen atom has at least two carbon atoms bound to it;
R
14
and R
15
are each independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or R
14
and R
15
taken together are hydrocarbylene substituted hydrocarbylene to form a carbocyclic ring;
R
18
is hydrocarbyl or substituted hydrocarbyl, and R
20
is hydrogen, hydrocarbyl or substituted hydrocarbyl or R
18
and R
20
taken together form a ring;
R
19
is hydrocarbyl or substituted hydrocarbyl, and R
21
is hydrogen, substituted hydrocarbyl or hydrocarbyl, or R
19
and R
21
taken together form a ring;
each R
17
is independently hydrogen, substituted hydrocarbyl or hydrocarbyl, or two of R
17
taken together form a ring;
R
27
and R
30
are independently hydrocarbyl or substituted hydrocarbyl;
R
28
and R
29
are each in independently hydrogen, hydrocarbyl or substituted hydrocarbyl; and
n is 2 or 3;
Ar
12
, Ar
13
, Ar
15
, Ar
16
, Ar
22
, Ar
23
, Ar
24
, and Ar
25
are each independently aryl or substituted aryl;
R
56
and R
57
are each independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or R
57
and R
57
taken together form a ring, and R
58
is hydrogen, hydrocarbyl or substituted hydrocarbyl or R
56
, R
57
and R
58
taken together form a ring;
each R
31
is independently hydrogen, substituted hydrocarbyl or hydrocarbyl, or two of R
31
taken together form a ring;
R
22
and R
23
are each independently hydrocarbyl or substituted hydrocarbyl, provided that the carbon atom bound to the imino nitrogen atom has at least two carbon atoms bound to it;
R
24
and R
25
are each independently hydrogen, hydrocarbyl, or substituted hydrocarbyl;
A is a &pgr;-allyl or &pgr;-benzyl group;
R
63
and R
67
are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
R
62
, R
61
, R
60
, R
59
, R
66
, R
65
, R
64
, R
70
, R
69
, R
68
, R
76
, R
77
, R
78
, R
79
, R
80
, R
81
, R
88
, R
89
, R
90
, R
91
and R
92
are each independently hydrogen, hydrocarbyl, substituted hydrocarbyl, an inert functional group, and provided that any two of these groups vicinal to one another taken together may form a ring;
R
73
is hydrocarbyl, substituted hydrocarbyl, —SR
132
, —OR
132
, or —NR
133
2
, R
72
is hydrogen, a functional group, hydrocarbyl or substituted hydrocarbyl, and R
71
is hydrocarbyl or substituted hydrocarbyl, and provided that R
73
and R
72
or R
72
and R
131
taken together may form a ring;
R
82
, R
83
, R
84
and R
85
are each independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or an inert functional group;
R
86
and R
87
are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
w is 1, 2 or 3;
Ar
26
, Ar
17
, Ar
18
, Ar
19
, Ar
20
and Ar
21
are each independently hydrocarbyl or substituted hydrocarbyl;
R
132
is hydrocarbyl or substituted hydrocarbyl;
each R
133
is independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
G and L are both N or G is CR
134
and L is CR
135
;
R
135
, R
93
and R
134
are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl, or any two of R
93
, R
134
and R
135
taken together form a ring;
R
94
, R
95
, R
96
, R
97
, R
98
, R
99
, R
100
, R
101
, R
102
, R
103
and R
104
are each independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or a functional group;
R
105
, R
106
, R
107
and R
108
are each independently hydrocarbyl or substituted hydrocarbyl;
R
109
and R
110
are each independently hydrocarbyl or substituted hydrocarbyl;
R
111
, R
112
, R
113
, and R
114
are each independently hydrogen, hydrocarbyl, substituted hydrocarbyl or a functional group;
both of T are S (sulfur) or N

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