This disclosure describes polymerization processes and processes for quenching polymerization reactions using reactive particulates, such as amorphous silica, as quenching agents, typically in solution or bulk polymerization processes.

The present invention relates to the polymerisation of one or more monomers in a gas phase reactor, and in particular provides a process for from the polymerisation of one or more monomers in a horizontal stirred bed gas phase reactor, wherein the process comprises: a. Polymerising a mixture comprising one or more monomers and hydrogen in the reactor to produce the polymer, b. Withdrawing from the reactor a gaseous stream, c. Passing the gaseous stream to a condenser in which it is partly condensed to produce a liquid phase and a remaining vapour phase, d. Passing the mixture of liquid phase and remaining vapour from the condenser to a separator in which there is maintained a liquid phase and a vapour phase, the volume of the liquid phase in the separator being a percentage, X, which is between 10 and 80% of the total volume of the separator, e. And recycling both liquid and vapour from the separator to the reactor, the mass rate of liquid returning to the reactor being L and the mass rate of vapour returning to the reactor being V, the two defining a ratio V/L,
characterised in that the hydrogen concentration in the reactor is changed and the change is effected at least in part by changing the V/L ratio by at least 10% and/or by changing the volume, X.

Catalyst deactivating agents and compositions containing catalyst deactivating agents are disclosed. These catalyst deactivating agents can be used in methods of controlling polymerization reactions, methods of terminating polymerization reactions, methods of operating polymerization reactors, and methods of transitioning between catalyst systems.

This disclosure describes polymerization processes and processes for quenching polymerization reactions using reactive particulates, such as amorphous silica, as quenching agents, typically in solution or bulk polymerization processes.

A process for the offline deactivation of at least one single site catalyst comprising contacting said catalyst with a deactivating agent selected from an aprotic low molecular weight carbonyl group containing organic compound or an aprotic low molecular weight orthoester or an aprotic low molecular weight acetal compound.

The invention relates to a process for transitioning from a first continuous polymerization in a gas phase reactor conducted in the presence of a metallocene catalyst to a second polymerization conducted in the presence of a Ziegler-Natta catalyst in the gas phase reactor wherein the metallocene catalyst and the Ziegler-Natta catalysts are incompatible, the process comprising: (a) discontinuing the introduction of the metallocene catalyst into the gas phase reactor; (b) introducing an effective amount of cyclohexylamine into the reactor to at least partially deactivate the metallocene catalyst; (c) introducing an organometallic compound into the reactor and reacting the organometallic compound with cyclohexylamine; (d) degas the gas composition of the reactor and build up a new composition inside the reactor for the second polymerization with the Ziegler-Natta catalyst (e) introducing the Ziegler-Natta catalyst into the reactor.

A continuous solution polymerization process is disclosed wherein at least two catalyst formulations are employed. A first homogeneous catalyst formulation is employed in a first reactor to produce a first ethylene interpolymer and a first heterogeneous catalyst formulation is employed in a second reactor to produce a second ethylene interpolymer. Optionally a third ethylene interpolymer is formed in a third reactor. The resulting ethylene interpolymer products possess desirable properties in a variety of end use applications, for example in film applications. A means for increasing the molecular weight of the first ethylene interpolymer is disclosed and/or a means for increasing the temperature of the first reactor, relative to a third homogeneous catalyst formulation. A means for reducing the (-olefin/ethylene) weight ratio in the first reactor is disclosed and/or reducing the density of the first ethylene interpolymer, relative to a third homogeneous catalyst formulation.

The invention relates to a process for transitioning from a first continuous polymerization in a gas phase reactor conducted in the presence of a metallocene catalyst to a second polymerization conducted in the presence of a Ziegler-Natta catalyst in the gas phase reactor wherein the metallocene catalyst and the Ziegler-Natta catalysts are incompatible, the process comprising: (a) discontinuing the introduction of the metallocene catalyst into the gas phase reactor; (b) introducing an effective amount of cyclohexylamine into the reactor to at least partially deactivate the metallocene catalyst; (c) introducing an organometallic compound into the reactor and reacting the organometallic compound with cyclohexylamine; (d) degas the gas composition of the reactor and build up a new composition inside the reactor for the second polymerization with the Ziegler-Natta catalyst (e) introducing the Ziegler-Natta catalyst into the reactor.

Catalyst deactivating agents and compositions containing catalyst deactivating agents are disclosed. These catalyst deactivating agents can be used in methods of controlling polymerization reactions, methods of terminating polymerization reactions, methods of operating polymerization reactors, and methods of transitioning between catalyst systems.

Catalyst deactivating agents and compositions containing catalyst deactivating agents are disclosed. These catalyst deactivating agents can be used in methods of controlling polymerization reactions, methods of terminating polymerization reactions, methods of operating polymerization reactors, and methods of transitioning between catalyst systems.