Polymerisation process
AssigneeBP Chemicals Limited
InventorJohn Norman Reid Samson
Life of this patent
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Abstract
A process for transitioning between two catalysts is disclosed, comprising the steps of a) discontinuing the feed of the first catalyst into the polymerization reactor, and then b) introducing the second catalyst into the reactor, wherein one of the catalysts comprises a late transition metal catalyst and the other is a catalyst which is incompatible therewith. It is preferred that the late transition metal catalyst is a 2,6-diacetyl pyridine iron catalyst.
Claims13
Process for the polymerisation or copolymerisation of 1-olefins in which a transition is made from polymerisation using a first catalyst to polymerisation using a second catalyst, comprising the steps of
- a) discontinuing the feed of the first catalyst into the polymerisation reactor in which polymerisation with said first catalyst has been occurring, and then
- b) introducing the second catalyst into the reactor,
- wherein one of the catalysts comprises a late transition metal catalyst and the other is a catalyst which is incompatible therewith.
Process according to any preceding claim, wherein the transition is effected by introducing the second catalyst without first eliminating all activity of the first catalyst and/or without first removing all traces of the first catalyst.
Process according to any preceding claim, wherein the late transition metal catalyst comprises a complex of the formula
- 4
- wherein
- M is Fe[II], Fe[III], Co[II], Co[III], Ni[II], Rh[II], Rh[III], Ru[II], Ru[III], Ru[IV] or Pd[Il];
- X represents an atom or group covalently or ionically bonded to the transition metal M;
- T is the oxidation state of the transition metal M and b is the valency of the atom or group X;
- L is a group datively bound to M, and n is from 0 to 5;
- A1 to A3 are each independently N or P or CR, with the proviso that at least one is CR;
- and R4 to R7 are each independently selected from hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substituted heterohydrocarbyl or SiR′3 where each R′ is independently selected from hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl and substituted heterohydrocarbyl.
Compound according to any preceding claim wherein the non late transition metal catalyst comprises a Phillips type (chromium) catalyst.
Process according to any preceding claim, wherein the conditions are slurry phase or gas phase.
Dependencies are inferred from the claim text.