Lg Chem, Ltd

Jae Won Heo

Young Min Kim

Jin Hyoung Lee

Young Hwan Jeong

Jae Min Suk

Yoo Vin Kim

Su Jeong Han

Sun Haeng Chung

Chang Hong Bak

The present invention relates to a method for preparing a conjugated diene-based polymer, characterized in using a dimer acid saponified material as an emulsifier in a polymerization initiation step and injecting a monomer and the emulsifier in three or more installments after initiating polymerization, and the conjugated diene-based polymer prepared by the preparation method of the present invention has excellent physical properties such as impact strength and reflection haze.

Method for preparing conjugated diene-based polymer

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

Provided are a method of preparing a graft copolymer, a graft copolymer, and a thermoplastic resin molded article. The method of preparing a graft copolymer includes 1) adding a conjugated diene-based monomer and performing polymerization to prepare a conjugated diene-based polymer; and 2) adding the conjugated diene-based polymer, an aromatic vinyl monomer, and a vinyl cyan monomer and performing polymerization to prepare a graft copolymer, wherein an emulsifier having an APHA color value of 50 or less and a critical micelle concentration of 1 to 50 g/l is added, so that excellent polymerization stability, colorability, light resistance, and surface clarity are exhibited.

Method of preparing graft copolymer, graft copolymer, and thermoplastic resin molded article

The present invention relates to a method for preparing a copolymer, comprising adding a surface-modified silica nanopowder, a vinyl cyan-based monomer, and an aromatic vinyl-based monomer and polymerizing the same, wherein the surface-modified silica nanopowder is a silica nanopowder which are surface-modified with a chain transfer agent for reversible addition-fragmentation chain transfer polymerization; a copolymer prepared according to the method; and a thermoplastic resin-molded article manufactured using the copolymer. More particularly, the present invention relates to a method for preparing a copolymer having improved heat shrinkage and reflection haze; a copolymer; and a thermoplastic resin-molded article.

Method for preparing copolymer and copolymer

A method of preparing a diene-based rubber latex, a method of preparing an ABS-based graft copolymer including the same, and a method of manufacturing an ABS-based injection-molded article include preparing an in-situ bimodal rubber latex, in which a small-diameter polymer and a large-diameter polymer are formed in a desired ratio, by controlling contents, addition time points, and types of reactants when a conjugated diene based monomer, a crosslinking agent with a long linear chain end, an emulsifier including a multimeric acid of an unsaturated fatty acid or a metal salt thereof, and a molecular weight regulator are polymerized.

Method of preparing diene-based rubber latex, method of preparing ABS-based graft copolymer and method of manufacturing injection-molded article

The present invention relates to a method of preparing an ABS-based resin composition and a method of manufacturing an ABS-based injection-molded article including the same. More particularly, the present invention provides a method of preparing an ABS-based resin composition using a multimeric acid of unsaturated fatty acid or a metal salt thereof, as an emulsifier, in a diene-based rubber latex polymerization step and an ABS-based graft polymerization step. In accordance with the present invention, when an ABS-based resin composition is prepared using a multimeric acid of unsaturated fatty acid or a metal salt thereof as an emulsifier, stability of polymerization is secured and surface characteristics, such as surface gloss or sharpness, of an ABS-based injection-molded article are improved.

Method of preparing ABS-based resin composition and method of manufacturing ABS-based injection-molded article including the same

The present invention relates to a method of preparing an ABS-based graft copolymer having improved impact strength and an ABS-based injection-molded article including the same. More particularly, the present invention provides an ABS-based copolymer resin having improved impact strength by optimizing structures of large-diameter diene-based rubber latex particles and a matrix structure between ABS-based copolymer particles and a SAN resin through introduction of a multimeric acid of an unsaturated fatty acid or a metal salt thereof as an emulsifier in a large-diameter diene-based rubber latex polymerization step and an ABS graft polymerization step.

Method of preparing ABS-based graft copolymer having improved impact strength and method of manufacturing ABS-based injection-molded article including the same

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Daejeon, South Korea

Jae Won Heo