Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2001-05-16
2004-02-17
Lu, Caixia (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C556S053000, C556S011000, C585S010000, C502S103000, C502S152000, C526S134000, C526S160000, C526S170000, C526S351000, C526S943000
Reexamination Certificate
active
06693156
ABSTRACT:
The present invention relates to new methylene-bridged metallocenes, to the corresponding ligands, to a new process for their preparation and to the use of said metallocenes as catalytic components in the polymerization of olefins.
PRIOR ART DISCLOSURE
Stereorigid chiral metallocene compounds possessing two bridged cyclopentadienyl groups condensed to a C
5
-C
7
ring are well known in the state of the art and are mainly used as catalytic components in olefin polymerization processes; in particular, metallocene compounds possessing two bridged indenyl groups are widely used in the preparation of stereoregular polyolefins.
The numbering of the substituents on the indenyl group, to which reference is made in the present application, in accordance with the IUPAC nomenclature, is the following:
In the bridged indenyl metallocene compounds known in the state of the art, the indenyl groups are linked together by divalent radicals containing one or more carbon atoms and/or heteroatoms; the divalent bridging groups are generally linked to the 1 position of said indenyl groups, and therefore, the common indenyl metallocenes are 1-indenyl compounds. For example, the European patent application EP 0 485 823 describes a class of bridged bis(1-indenyl) metallocenes, wherein the indenyl groups have a substituent other than hydrogen in the 2 position and are bridged in the 1 position by means of a bridge containing 1 or more carbon atoms (e.g. an ethylene or isopropylidene group) or containing heteroatoms (e.g. a dimethyl-silyl or a diphenyl-silyl group).
The European patent application EP 0 372 414 describes a very broad class of bridged or unbridged metallocenes; among the many metallocenes exemplified, two specific bis-indenyl metallocene compounds are reported, wherein the ethylene group bridging the indenyl groups is linked to the 1 position of one indenyl group and to the 2 position of the other indenyl group (formulae II-1 and II-2, on page 5 of said application).
The International patent application WO 94/11406 describes a very broad class of metallocene compounds of formula R′ Ind-M—(Cp)Q
k
, wherein: Ind is an indenyl group; R′ is a substituent, other than hydrogen, linked in the 2 position of said indenyl group; Cp is a cyclopentadienyl group; M is a transition metal belonging to group 3, 4, 5 or 6 of the Periodic Table of Elements; and Q is a sigma-ligand of the metal M, k being an integer linked to the valence of M. Among the huge plethora of embodiments envisaged in the reported general formula, R′ can form a bridge between the 2 position of the Ind group and the Cp group of the above formula; therefore, the class of bridged bis(2-indenyl) compounds is generically described. The definition of the bridging group R′ is very broad too, the preferred bridges linking the two indenyl residues being hydrocarbon groups (preferably alkenyl or arylalkenyl groups) or groups containing at least one heteroatom belonging to Group 14, 15 or 16 of the Periodic Table of the Elements. In particular, working example XIV of this application describes the synthesis of methylene-bis(2-indenyl)zirconium dichloride, comprising numerous and laborious process steps. Said bis-indenyl zirconocenes have been tested in ethylene (co)polymerization (Examples XV-XIX) and give ethylene homopolymers in very low yield and ethylene/propylene copolymers having very low molecular weights and in low yields too. Furthermore, the same Applicant has demonstrated that methylene-bis(2-indenyl)zirconium dichloride is totally inactive in propylene polymerization, as will be described in the following. The European patent application EP 0 722 949 describes a process for preparing bis-cyclopentadienyl compounds bridged by a divalent CR
I
R
II
group, wherein R
I
is hydrogen or an alkyl radical, and R
II
is an alkyl or aryl radical. This process comprises the reactionlof a ketone or an aldehyde of formula R
I
R
II
CO, having the desired R
I
and R
II
groups, with a cyclopentadienyl compound, in the presence of a base and of an oxygen-containing solvent having an atomic ratio carbon/oxygen not higher than 3. However, the class of bis-cyclopentadienyl compounds obtainable with this process does not encompass compounds bridged with a methylene group; moreover, when R
I
R
II
CO is reacted with :an indenyl compound in the presence of a base, according to the above-mentioned process conditions, only bridged bis(1-indenyl) derivatives are obtained.
The European patent application EP 0 832 866 describes a process for preparing methylene-bridged bis-cyclopentadienyl compounds by reacting, in a two- or more-phases system, one or two cyclopentadienyl compounds with formaldehyde in the presence of a base and of a phase-transfer catalyst. Nevertheless, this application does not disclose any compounds wherein the two indenyl groups are linked in position 2; in fact, as evident from working example 1, this process leads to bis-(1-indenyl) derivatives and does not allow bridged bis(2-indenyl) compounds to be obtained.
WO 98/43931 (app. no. PCT/EP 98/01930), in the name of the same Applicant, describes a process for preparing methylene-bridged bis-cyclopentadienyl compounds, comprising the reaction of formaldehyde with a suitable cyclopentadienyl compound, in the presence of a base and a solvent having a dielectric constant, measured at 25° C., higher than 7. Also in this case, the process allows only bis-indenyl compounds to be obtained, wherein the two indenyl moieties are bridged in position 1.
The Prins reaction (i.e., the acid-catalyzed condensation of carbonyl compounds and olefins) on indene has been described several times in the state of the art; as reported by Carleton W. Roberts (
Friedel
-
Crafts and related reactions
, vol., Part 2, page. 1192-1193, 1964, Interscience N.Y.), the reaction of indene with formaldehyde in the presence of acids does not give bis-indenyl products, but leads to the dioxane 1-hydroxy-2-hydroxymethylindan methylene ether as the major product. The same reaction was carried out by A. E. Gol'dovskii et al. (laslo-Zhir. Prom-st., 1987(8): 31; Chemical Abstracts 108:167399), who obtained said dioxane from indene and CH
2
O, in the presence of H
2
SO
4
.
From what reported above, it would be highly desirable to provide methylene-bridged bis(2-indenyl) derivatives, obtainable by means of an easy and advantageous route for the preparation thereof.
SUMMARY OF THE INVENTION
The Applicant has now unexpectedly found a new class of metallocenes, particularly active as catalyst components for the polymerization of olefins; said metallocenes are characterized by the presence of two indenyl groups bridged in the 2 position by means of a methylene group.
Therefore, an object of the present invention is a methylene-bridged metallocene of formula (I):
wherein:
M is a transition metal belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups of the Periodic Table of the Elements (new IUPAC notation);
the substituents X, the same or different from each other, are monoanionic sigma ligands selected from the group consisting of hydrogen, halogen, —R, —OR, —OSO
2
CF
3
, —OCOR, —SR, —NR
2
and —PR
2
groups, wherein the R substituents are linear or branched, C
1
-C
20
, aliphatic hydrocarbon. C
3
-C
20
cycloalkyl, C
6
-C
20
aryl, C
7
-C
20
alkylaryl or C
7
-C
20
arylalkyl radicals optionally containing one or more atoms belonging to groups 13-17 of the Periodic Table of the Elements (new IUPAC notation), such as B, N, P, Al, Si, Ge, O, S and F atoms, and two R substituents may form a 5-7-membered ring; preferably, the substituents X are the same;
the substituents R
1
and R
2
, the same or different from each other, are selected from the group consisting of linear or branched, C
1
-C
20
, aliphatic hydrocarbon, C
3
-C
20
cycloalkyl, C
6
-C
20
aryl, C
7
-C
20
alkylaryl and C
7
-C
20
arylalkyl radicals, optionally containing one or more atoms belonging to groups 13-17 of the Periodic Table of the Elements (new IUPAC notation; such as B, N, P, Al, Si, Ge, O, S and F atoms), —OR,
Basell Polyolefine GmbH
Lu Caixia
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