Process for the preparation of a solid metallocene catalyst system and its use in polymerisation of olefins

Abstract

A process for the preparation of a solid olefin polymerisation catalyst system, comprising an organometallic compound of a transition metal of Group 3 to 10 of the Periodic Table (IUPAC 2007) in the form of solid particles comprising the steps of I) generating an emulsion by dispersing a liquid clathrate in a solvent (S) wherein (i) the solvent (S) constitutes the continuous phase of the emulsion and comprises a nonreactive fluorinated synthetic oil having a viscosity at 20 DEG C according to ASTM D445 of at least 10 cSt up to 2000 cSt, (ii) the liquid clathrate constitutes in form of droplets the dispersed phase of the emulsion, II) solidifying said dispersed phase to convert said droplets to solid particles and III) optionally recovering said particles to obtain said catalyst system, wherein the liquid clathrate comprises (a) a lattice being the reaction product of a1); a transition metal compound of formula (I) LmRnTXq wherein T is a transition metal of anyone of the groups 3 to 10 of the periodic table (IUPAC2007), preferably a transition metal of anyone of the groups 4 to 6 of the periodic table (IUPAC2007), more preferably titanium (Ti), zirconium (Zr) or hafnium (Hf), i.e. zirconium (Zr) or hafnium (Hf), each X is independently a monovalent sigma-ligand, each L is independently an organic ligand which coordinates to the transition metal (T), R is a bridging group linking said organic ligands (L), m is 2 or 3, preferably 2, n is 0, 1 or 2, preferably 1, q is 1, 2 or 3, preferably 2, m+q is equal to the valency of the transition metal (T), a2) a cocatalyst comprising aluminoxane a3) a compound being effective to form the lattice with the transition metal compound and / or the aluminoxaneand b) a hydrocarbon solvent (HS).

Description

technical field [0001] The invention relates to an improved method for preparing a solid metallocene catalyst system by emulsification / solidification technology, and the application of the catalyst system in olefin polymerization. [0002] In particular, the present invention describes the use of emulsification / solidification techniques for the preparation of solid metallocene catalyst systems in which the liquid clathrate constitutes the dispersed phase of the emulsion and has a viscosity at 20°C according to ASTM D445 of at least A non-reactive fluorinated synthetic oil of 10 cSt (centistokes) was used as the continuous phase. Background technique [0003] Many catalysts and processes are known for preparing olefin polymers. For example, Ziegler-Natta (ZN) catalyst compositions and chromium oxide compounds have been found useful in the preparation of polyolefins. [0004] Further, the use of metallocene catalysts in olefin polymerization has been known for many years and...

AI Technical Summary

Problems solved by technology

[0019] Also, the use of these highly reactive fluorinated compounds is considered problematic in terms of HS&E (Health, Safety and Environment), so the future availability of these compounds cannot be ensured

[0020] Many prior art catalyst systems have the disadvantage that in slurry reactors they tend to dissolve to some extent in the desired polymerization medium, thus degrading the morphology of the catalyst system, which in turn causes condensation in the reactor. Scale and flakes

Besides being a sensitive step, prepolymerization adds cost on an industrial scale

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