Korea Kumho Petrochemical Co., Ltd.

Ji Hyun Heo

Hyung J Lee

Seok Hyun Kang

Kyoung Ho Row

June Soo Park

Chang Kyo Shin

Sung Hoon Han

Hyung Jae Lee

Cheolbeom Bae

Se-Hee Jung

Disclosed is a copolymer including a first part including an aromatic vinyl-based monomer and a conjugated diene-based monomer; and a second part including an aromatic vinyl-based monomer and a conjugated diene-based monomer, wherein the content of the aromatic vinyl-based monomer is 35 to 45% by weight based on a total weight of the copolymer, and the copolymer satisfies Equation 1 below:V&#x3e;V&#x2003;&#x2003;&#x3c;Equation 1&#x3e;

Copolymer, rubber composition, and method of preparing the same

Disclosed is a method of preparing a rare-earth alkyl phosphate solution, the method including step (a) of preparing an alkyl phosphate amine salt solution by reacting an organic amine with an alkyl phosphate in a first solvent; step (b) of preparing a rare-earth metal salt solution by reacting a rare-earth metal oxide with an acid in the second solvent; and step (c) of mixing and reacting the alkyl phosphate amine salt solution with the rare-earth metal salt solution.

Method for preparing a solution of a rare-earth alkyl phosphate

A method for preparing a phenolic oligomer antioxidant with a very small residual content of butylated hydroxytoluene (BHT) is provided. Specifically, the method for preparing the phenolic oligomer antioxidant relates to a method which is capable of a BHT-free phenolic oligomer antioxidant or a phenolic oligomer antioxidant containing a trace amount of residual BHT by removing the precursor of BHT as much as possible by performing the concentration under the reduced pressure while injecting an inert gas to an intermediate product and/or removing BHT by performing the concentration under the reduced pressure while injecting an inert gas to the final product.

Preparing method of a phenolic oligomer antioxidant

Growing community of inventors

Seoul, South Korea

Ji Hyun Heo