The invention relates to an efficient process for the preparation of isoolefin polymers such as polyisobutene or butyl rubber by polymerization of isobutene and optionally further monomers in the presence of an initiator system prepared by continuously contacting at least one boron or aluminium compound and at least one initiator.

A method for producing a nitrile group-containing copolymer rubber including copolymerizing a monomer mixture containing an α,β-ethylenically unsaturated nitrile monomer and a conjugated diene monomer, in which the copolymer has a Mooney viscosity (ML1+4, 100° C.) in a range of 30 to 60 at a time point when a polymerization conversion rate is 60%, the copolymerization is carried out until the polymerization conversion rate reaches 85% or more, and the obtained nitrile group-containing copolymer rubber has a Mooney viscosity (ML1+4, 100° C.) of 85 to 150.

A method for producing a nitrile group-containing copolymer rubber including copolymerizing a monomer mixture containing an α,β-ethylenically unsaturated nitrile monomer and a conjugated diene monomer, in which the copolymer has a Mooney viscosity (ML1+4, 100° C.) in a range of 30 to 60 at a time point when a polymerization conversion rate is 60%, the copolymerization is carried out until the polymerization conversion rate reaches 85% or more, and the obtained nitrile group-containing copolymer rubber has a Mooney viscosity (ML1+4, 100° C.) of 85 to 150.

The invention relates to an efficient process for the preparation and isolation of rubber particles formed in aqueous media and highly pure rubbers obtained thereby. The invention further relates to copolymer products comprising the same or derived therefrom.

The invention relates to an efficient process for the preparation and isolation of rubber particles formed in aqueous media and highly pure rubbers obtained thereby. The invention further relates to copolymer products comprising the same or derived therefrom.

The invention relates to an efficient process for the preparation and isolation of rubber particles formed in aqueous media and highly pure rubbers obtained thereby. The invention further relates to copolymer products comprising the same or derived therefrom.

The present invention relates to a catalyst composition including an imidazolinium ion-based catalyst and an aluminum-based cocatalyst, and a method for preparing an isobutene-isoprene copolymer using the same.

The present invention relates to a catalyst composition including an imidazolinium ion-based catalyst and an aluminum-based cocatalyst, and a method for preparing an isobutene-isoprene copolymer using the same.

The present invention relates to a catalyst composition including an imidazolinium ion-based catalyst and an aluminum-based cocatalyst, and a method for preparing an isobutene-isoprene copolymer using the same.

The present invention relates to a method for halogenating an isobutene-isoprene copolymer by using an organic hypochlorite. By using the method of the present invention, a hydrogen halide byproduct may be rapidly recycled into a halogenating agent and reused. As a result, a halogenated isobutene-isoprene copolymer having the high content of secondary allyl halogen functional groups may be prepared by increasing the participation ratio of the halogenating agent in reaction and suppressing the rearrangement of the secondary allyl halogen functional groups. The halogenated isobutene-isoprene copolymer prepared according to the present invention may be effectively used in the crosslinking reaction with other rubber, and is industrially useful.