Lg Chem, Ltd

Chang Hong Bak

Young Min Kim

Jin Hyoung Lee

Young Hwan Jeong

Jae Min Suk

Jae Won Heo

Sang Jin Kim

Yoo Vin Kim

Su Jeong Han

Joon Hee Cho

Jeong Hun Cho

Ki Yeon Jo

Hye Jin Han

Provided is a method of preparing a diene-based rubber polymer, which includes: adding each of a diene-based monomer, a molecular-weight regulator, an initiator, and an emulsifier to a reactor a first time and carrying out polymerization; adding a molecular-weight regulator to the reactor a second time when a polymerization conversion rate of 48 to 72% is reached and carrying out polymerization; adding a diene-based monomer to the reactor a second time when a polymerization conversion rate of 63 to 77% is reached and carrying out polymerization; adding each of an initiator and an emulsifier to the reactor a second time when a polymerization conversion rate of 68 to 81% is reached and carrying out polymerization; and adding each of an initiator and an emulsifier to the reactor a third time when a polymerization conversion rate of 85 to 91% is reached and carrying out polymerization.

Method of preparing diene-based rubber polymer and method of preparing graft polymer including the diene-based rubber polymer

The present invention relates to a method for preparing a conjugated diene-based polymer, which includes a step of preparing a conjugated diene-based polymer by initiating and carrying out polymerization while continuously adding conjugated diene-based monomers to a reactor, and in which an emulsifier is dividedly added before the initiation of the polymerization and when a polymerization conversion rate of 31% to 80% is reached. More particularly, the present invention relates to: a method for preparing a conjugated diene-based polymer and a method for preparing a graft copolymer including the method for preparing a conjugated diene-based polymer, by which a total usage amount of an emulsifier can be reduced.

Method for preparing conjugated diene-based polymer and method for preparing graft copolymer comprising the same

The present invention relates to a diene-based rubber latex including a polymer aggregate and having an extra large diameter, a method for preparing same and a graft copolymer with a core-shell structure, including same and having excellent impact strength and surface properties. A diene-based rubber latex of which 14 wt % to 26 wt % has diameter of 100 nm to less than 300 nm, 62 wt % to 81 wt % has a diameter of 300 nm to less than 800 nm, and 5 wt % to 14 wt % has a diameter of 800 nm to less than 1000 nm, based on 100 wt % of total rubber particles.

Diene-based rubber latex, method for preparing thereof and graft copolymer with core-shell structure comprising the same

The present invention relates to a method for producing an acrylonitrile-based fiber, the method including: providing a polymer solution including an acrylonitrile-based copolymer containing a carboxylic acid group; mixing 100 parts by weight of the polymer solution with 1 to 6 parts by weight of a hydrophilization solution containing an organic solvent and ammonia water in a weight ratio of 95:5 to 60:40 to prepare a spinning stock solution; and spinning the spinning stock solution. The method controls the viscosity of the spinning stock solution to improve the stretchability and strength of the acrylonitrile-based fiber, and suppresses the occurrence of gelation.

Method for producing acrylonitrile-based fiber

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Daejeon, South Korea

Chang Hong Bak