Claims
- 1. A process for polymerizing ethylene to form branched low-pressure polyethylene having a main chain and side chains of different lengths, the side chains having lengths of 14-200 carbon atoms, which comprises reacting ethylene in the presence of a catalyst at a pressure of 1-1000 bar and at a temperature of 20-200 degrees C, the catalyst comprising a preformed bifunctional catalyst obtained by bonding in an inert reaction medium:
- i. a first catalyst comprising a chromium compound on a silica or aluminum oxide support, wherein the quantity of chromium compound, based on the quantity of the support, is from 0.1 to 3.5% by weight, the chromium compound being in the form of a coordinatively unsaturated chromium (II) and/or chromium (III) compound which is obtained by treating the support with an aqueous solution of a chromium (VI) compound, separating the solution from the impregnated support, drying the impregnated support and heating it at temperatures above 500.degree. C. in an oxygen stream for 1/2 to 3 hours and subsequently reducing the chromium (VI) compound with a gaseous reducing agent at 250.degree. to 500.degree. C. to yield a coordinatively unsaturated chromium (II) compound; with
- ii) a second catalyst comprising a nickel compound selected from the group consisting of:
- a) a nickel compound produced by reaction of a nickel (O) compound, or a nickel compound which can be converted into a nickel (O) compound in situ, with an adduct or a mixture of a quinoid compound and a tertiary phosphine and with a compound of the formula (I) ##STR5## in which R.sup.1, R.sup.2 and R.sup.3 , independently of one another, denote optionally halogen-, hydroxyl-, C.sub.1 -C.sub.20 -alkoxy-, nitro- or C.sub.6 -C.sub.12 -aryloxy-substituted C.sub.1 -C.sub.20 -alkyl, C.sub.2 -C.sub.20 -alkenyl, C.sub.6 -C.sub.12 -aryl or C.sub.3 -C.sub.8 -cycloalkyl, or denote C.sub.6 -C.sub.12 -aryl-C.sub.1 -C.sub.20 -alkyl, C.sub.1 -C.sub.20 -alkyl-C.sub.6 -C.sub.12 -aryl, C.sub.6 -C.sub.12 -aryl-C.sub.2 -C.sub.20 -alkenyl, C.sub.1 -C.sub.20 -alkyl-C.sub.3 -C.sub.8 -cycloalkyl and C.sub.6 -C.sub.12 -aryl-C.sub.3 -C.sub.8 -cycloalkyl, di-C.sub.1 -C.sub.4 -alkylamino, phenoxy, or alkoxy,
- X denotes 0, NR.sup.4 or ##STR6## R.sup.4, R.sup.5 and R.sup.6, independently of one another, denote hydrogen, acyl, silyl, halogen, cyano, nitrophenyl or R.sup.1 and
- n denotes zero or 1;
- and
- b) a nickel compound obtained by reacting a nickel (O) compound or a compound which can be converted into a nickel (O) compound in situ with compounds of the formulae (I) as defined above and (III) ##STR7## in which R.sup.10 -R.sup.14 represent, independently of one another, optionally halogen-, hydroxyl, C.sub.1 -C.sub.20 -alkoxy-, or C.sub.6 -C.sub.12 -aryloxy-substituted C.sub.1 -C.sub.20 -alkyl, C.sub.6 -C.sub.12 -aryl, C.sub.2 -C.sub.30 -alkenyl or C.sub.3 -C.sub.8 -cycloalkyl, C.sub.6 -C.sub.12 -aryl-C.sub.1 -C.sub.20 -alkyl, C.sub.1 -C.sub.20 -alkyl-C.sub.6 -C.sub.12 -aryl, halogen, hydroxyl, C.sub.1 -C.sub.20 -alkoxy, or C.sub.6 -C.sub.12 -aryloxy, in addition to which R.sup.13 may be hydrogen, and
- R.sup.14 may be hydrogen, acyl or sulphonate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
36 21 763.3 |
Jun 1986 |
DEX |
|
Parent Case Info
This is a divisional of Ser. No. 08/607,651, filed Feb. 27, 1996, now U.S. Pat. No. 5,616,529 which is a continuation of Ser. No. 08/357,157 filed Dec. 15, 1994, now abandoned, which is a continuation of 08/162,788 filed Dec. 6, 1993, now abandoned which is a divisional of 07/852,916 filed Mar. 13, 1992, now abandoned which is a continuation of 07/332,292 filed Mar. 31, 1989 now abandoned which is a continuation of 07/063,026 filed Jun. 17, 1987 now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (2)
Number |
Date |
Country |
594127 |
Feb 1978 |
SUX |
858945 |
Jan 1961 |
GBX |
Divisions (2)
|
Number |
Date |
Country |
Parent |
607651 |
Feb 1996 |
|
Parent |
852916 |
Mar 1992 |
|
Continuations (4)
|
Number |
Date |
Country |
Parent |
357157 |
Dec 1994 |
|
Parent |
162788 |
Dec 1993 |
|
Parent |
332292 |
Mar 1989 |
|
Parent |
63026 |
Jun 1987 |
|