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

A vulcanizable composition comprising rubber component, a filler, and a curing agent, where the rubber component includes a block copolymer of polybutadiene and polyisoprene, and where the block copolymer has a cis content of at least 90%.

The present disclosure provides a preparation method of a homogeneous rare earth catalyst. In the present disclosure, a depolymerizing agent is introduced into the homogeneous rare earth catalyst to promote complete depolymerization of an alkyl aluminum trimer into monomolecular alkyl aluminum. As a result, there is an increase in the number of the alkyl aluminum which serves as an effective chain transfer agent, resulting in a greatly improved chain transfer rate, such that a polymerization system has completed the chain transfer in an early stage of the reaction. Accordingly, an aluminum terminal molecular chain has an increased concentration, leading to an accelerated exchange with an active center propagating chain and a decreased influence caused by an increased viscosity of the system, maintaining living polymerization of the system.

The compatibility between silica fillers and synthetic rubbers which are synthesized utilizing lanthanide-based catalyst systems, such as neodymium catalyst systems can be improved by terminating the polymerization with a vinyl silane terminating agent. In doing so the vinyl silane is allowed to react with the polymer chain ends of the neodymium rubber to functionalize the chain ends of the polymer chains with silicon containing groups. This results in the rubber having better characteristics for utilization in tire rubber formulations, such a tire tread formulations, that exhibit improved wear characteristics and lower rolling resistance. The process for the synthesis of such functionalized polydiene rubber comprises (1) polymerizing a diene monomer in the presence of a lanthanide-based catalyst system, and (2) terminating the polymerization with a vinyl silane terminator. The functionalized polydiene rubber composition made by this method is comprised of a polydiene rubber which is functionalized at its chain ends with a silicon containing group.

A method for preparing a modified conjugated diene-based polymer is provided. The method is characterized in adding a polyoxyethylene phosphate ester-based compound having a specific structure together with sulfur chloride modifier during modification, by which modification reproducibility may be markedly improved, stable process may be performed, the changing degree of the physical properties, specifically a Mooney viscosity increasing ratio and the degree of branching of a modified conjugated diene-based polymer according to modification conditions may be anticipated, and the changing degree of a Mooney viscosity increasing ratio and the degree of branching may be easily controlled by controlling modification conditions.

A method for preparing a modified conjugated diene-based polymer having excellent compounding properties and improved processability is disclosed herein. According to the method, a first polymer including a functional group is prepared using a modifier represented by Formula 1, and the first polymer is mixed with a sulfur halide. A modified conjugated diene-based polymer having excellent affinity with a filler, excellent compounding properties such as tensile properties and viscoelasticity properties, and excellent compounding processability, may be prepared.

A method for preparing a modified conjugated diene-based polymer having excellent compounding properties and improved processability is disclosed herein. According to the method, a first polymer including a functional group is prepared using a modifier represented by Formula 1, and the first polymer is mixed with a sulfur halide. A modified conjugated diene-based polymer having excellent affinity with a filler, excellent compounding properties such as tensile properties and viscoelasticity properties, and excellent compounding processability, may be prepared.

A vulcanizable composition comprising rubber component, a filler, and a curing agent, where the rubber component includes a block copolymer of polybutadiene and polyisoprene, and where the block copolymer has a cis content of at least 90%.

A method for preparing a catalyst for use in polymerizing a conjugated diene-based monomer, the catalyst, and a method for preparing a conjugated diene-based polymer using the same are disclosed herein. In an embodiment, a method of preparing a catalyst comprises mixing a lanthanide rare earth element-containing compound, an alkylating agent compound and a halogen compound in the presence of a solvent to prepare a catalyst composition, adding a conjugated diene-based monomer to the catalyst composition to form a preformed catalyst composition, and aging the preformed catalyst composition at a temperature of −1° C. to −15° C. for 3 hours to 98 hours to prepare the catalyst. The catalyst has excellent catalyst activity and polymerization reactivity and is useful for preparing a conjugated diene-based polymer which has an excellent modification ratio and improved compounding properties.

Described are lanthanide-containing metal coordination complexes which may be used as precursors in thin film depositions, e.g., atomic layer deposition processes. More specifically, described are homoleptic lanthanide-aminoalkoxide metal coordination complexes, lanthanide-carbohydrazide metal coordination complexes, and lanthanide-diazadiene metal coordination complexes. Additionally, methods for depositing lanthanide-containing films through an atomic layer deposition process are described.