| 摘要 |
PURPOSE: A method for preparing a thermoplastic resin used as an impact resistant modifier of a PVC resin and a method for preparing its intermediate rubber latex, are provided to reduce the aggregate of an impact resistant modifier, thereby improving impact resistance without deterioration of transparency. CONSTITUTION: The rubber latex is prepared by emulsion polymerizing a monomer mixture comprising a butadiene-based monomer and a vinyl aromatic monomer, wherein a water-soluble electrolyte and an emulsifier are added before an emulsion polymerization and when a polymerization conversion rate is 60-80 %. The thermoplastic resin is prepared by adding an alkyl acrylate-based monomer and an emulsifier to the rubber latex to obtain a first graft polymer; and adding a vinyl aromatic monomer and an emulsifier to the obtained polymer to obtain a second graft polymer. Preferably the butadiene-based monomer is 1,3-butadiene; the vinyl aromatic monomer is at least one selected from the group consisting of styrene, α-methylstyrene, vinyl toluene, α-chlorostyrene, o-methylstyrene, dichlorostyrene and vinyl naphthalene; and the water-soluble electrolyte is at least one selected from the group consisting of sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, sodium phosphate, potassium phosphate, potassium carbonate and sodium carbonate.
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