The invention relates to a process for transitioning from a first continuous polymerization reaction in a reactor, for example a gas-phase reactor conducted in the presence of a first catalyst to a second continuous polymerization reaction in the react or conducted in the presence of a second catalyst, wherein the first and second catalysts are incompatible, the process comprising: (a) discontinuing the introduction of the first catalyst from a catalyst feeding system into a reactor and emptying the catalyst feeding system of the first catalyst; (b) introducing a first catalyst killer to the reactor to substantially deactivate the first catalyst in the reactor; (c) introducing a second catalyst killer to the catalyst feeding system to substantially deactivate the first catalyst in the catalyst feeding system; (d) introducing a second catalyst to the catalyst feeding system and (e) introducing the second catalyst to the reactor from the catalyst feeding system, wherein the second catalyst killer is the same as or different from the first catalyst killer.

[Problem to be solved] There is provided a process for producing an olefin polymer that is capable of producing an olefin polymer having high heat resistance and high molecular weight with excellent catalytic activity. [Solution to problem] The process for producing an olefin polymer includes a step of polymerizing at least one olefin selected from ethylene and -olefins having 4 to 30 carbon atoms in the presence of an olefin polymerization catalyst containing a transition metal compound represented by the general formula [I], the olefin polymer including constituent units derived from ethylene and -olefins having 4 to 30 carbon atoms in a total amount between more than 50 mol % and not more than 100 mol %, ##STR00001## [in the formula [I], R.sup.1, R.sup.3 and R.sup.5 to R.sup.16 are each independently a hydrogen atom, a hydrocarbon group or the like; R.sup.2 is a hydrocarbon group or the like; R.sup.4 is a hydrogen atom; M is a transition metal of Group IV; Q is a halogen atom or the like; and j is an integer of 1 to 4].

This invention relates to high porosity (15%) and/or low pore diameter (PD<165 m) propylene polymers and propylene polymerization processes using single site catalyst systems with supports having high surface area (SA400 m.sup.2/g), low pore volume (PV2 mL/g), a specific mean pore diameter range (PD=1-20 nm), and high average particle size (PS30 m).

An ethylene-copolymerized olefin copolymer having a high comonomer dispersion index, a preparation method therefor, an application thereof, and a composition comprising an ethylene--olefin copolymer are disclosed. The ethylene--olefin copolymer contains 70-95 mol % a structural unit derived from ethylene and 5-30 mol % a structural unit derived from -olefin. The -olefin is an olefin having 5-10 carbon atoms. The dispersion index RMD of the -olefin structural unit in the molecular chain is greater than 102%. The ethylene--olefin copolymer has a high comonomer dispersion index.

Disclosed herein are catalyst compositions containing bicyclic bridged metallocene compounds. These catalyst compositions can be used for the polymerization of olefins. For example, ethylene polymers produced using these catalyst compositions can be characterized by low molecular weights and high melt flow rates, and can be produced without the addition of hydrogen.

[Problem to be solved]

There is provided a process for producing an olefin polymer that is capable of producing an olefin polymer having high heat resistance and high molecular weight with excellent catalytic activity.

[Solution to problem]

The process for producing an olefin polymer includes a step of polymerizing at least one olefin selected from ethylene and -olefins having 4 to 30 carbon atoms in the presence of an olefin polymerization catalyst containing a transition metal compound represented by the general formula [I], the olefin polymer including constituent units derived from ethylene and -olefins having 4 to 30 carbon atoms in a total amount between more than 50 mol % and not more than 100 mol %,

##STR00001##

[in the formula [I], R.sup.1, R.sup.3 and R.sup.5 to R.sup.16 are each independently a hydrogen atom, a hydrocarbon group or the like; R.sup.2 is a hydrocarbon group or the like; R.sup.4 is a hydrogen atom; M is a transition metal of Group IV; Q is a halogen atom or the like; and j is an integer of 1 to 4].

The invention provides a specific metallocene compound and an olefin polymerization catalyst for use for a catalyst for producing an olefin polymer having a sufficiently high molecular weight while maintaining excellent copolymerizability at a polymerization temperature and under polymerization conditions industrially advantageous in polymerization of an olefin such as ethylene or the like, and provides a method for producing nan olefin polymer using the catalyst.

This invention relates to a compound represented by the formula: T.sub.yLAMX.sub.n2 wherein: A is a substituted or unsubstituted tetrahydro-as-indacenyl group bonded to M; L is substituted or unsubstituted monocyclic or polycyclic arenyl ligand or monocyclic or polycyclic heteroarenyl ligand bonded to M; M is a group 3, 4, 5, or 6 transition metal (preferably group 4); T is a bridging group bonded to L and A; y is 0 or 1, indicating the absence or presence of T; X is a leaving group, typically a univalent anionic ligand, or two Xs are joined and bound to the metal atom to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene; n is the oxidation state of M and is 3, 4, 5, or 6.

This invention relates to methods to prepare and compositions pertaining to branched ethylene-propylene copolymers that include at least 50% ethylene content by weight as determined by FTIR; a g.sub.vis of less than 0.95; a M.sub.w of 125,000 to 300,000; a methylene sequence length of 6 or greater as determined by .sup.13C NMR, wherein the percentage of sequences of the length of 6 or greater is more than 32%; and can have greater than 50% vinyl chain end functionality.

This invention relates to methods to prepare and compositions pertaining to branched ethylene-propylene copolymers that include at least 50% ethylene content by weight as determined by FTIR; a g.sub.vis of less than 0.95; a M.sub.w of 125,000 to 300,000; a methylene sequence length of 6 or greater as determined by .sup.13C NMR, wherein the percentage of sequences of the length of 6 or greater is more than 32%; and can have greater than 50% vinyl chain end functionality.