Methods for simultaneously determining the concentrations of transition metal compounds in solutions containing two or more transition metal compounds are described. Polymerization reactor systems providing real-time monitoring and control of the concentrations of the transition metal components of a multicomponent catalyst system are disclosed, as well as methods for operating such polymerization reactor systems, and for improving methods of preparing the multicomponent catalyst system.

Methods for simultaneously determining the concentrations of transition metal compounds in solutions containing two or more transition metal compounds are described. Polymerization reactor systems providing real-time monitoring and control of the concentrations of the transition metal components of a multicomponent catalyst system are disclosed, as well as methods for operating such polymerization reactor systems, and for improving methods of preparing the multicomponent catalyst system.

Provided is a method for preparing a chlorinated polyvinyl chloride resin, and more particularly, a method for preparing a chlorinated polyvinyl chloride resin including a neutralization process for neutralizing to pH of 2 to 5 using metal hydroxide as a first neutralizing agent a), and completing neutralization using a carbonate-based compound as a second neutralizing agent b), wherein residual hydrochloric acid in pores of the chlorinated polyvinyl chloride resin obtained by chlorination of a polyvinyl chloride or a vinyl chloride-based copolymer may be efficiently removed, and thermal stability and extrusion appearance of processed articles may be improved.

The present invention provides a method for preparing a butene oligomer including a step of oligomerizing a polymerization solution including a halogenated hydrocarbon solvent, a nonpolar hydrocarbon solvent and an isobutene monomer in the presence of an organometal catalyst.

The present invention provides a method for preparing a butene oligomer including a step of oligomerizing a polymerization solution including a halogenated hydrocarbon solvent, a nonpolar hydrocarbon solvent and an isobutene monomer in the presence of an organometal catalyst.

The present invention provides a method for preparing a butene oligomer including a step of oligomerizing a polymerization solution including a halogenated hydrocarbon solvent, a nonpolar hydrocarbon solvent and an isobutene monomer in the presence of an organometal catalyst.

The present invention relates to a catalyst composition including an oxonium ion-based catalyst represented by the following Formula 1, and an additive, and a method for preparing polyisobutene using the same:

##STR00001## wherein R, R.sub.1 to R.sub.4, and o, p, q and r are described herein.

The present invention relates to a catalyst composition including an oxonium ion-based catalyst represented by the following Formula 1, and an additive, and a method for preparing polyisobutene using the same:

##STR00001## wherein R, R.sub.1 to R.sub.4, and o, p, q and r are described herein.

Provided is a method of preparing a graft polymer, which includes: polymerizing a monomer mixture comprising a carboxylic acid monomer and methyl acrylate, wherein the carboxylic acid monomer is included at 1.5 to 2.5 wt %, and thus preparing an acrylic coagulant having an average particle diameter of 60 to 70 nm; polymerizing diene-based monomers in the presence of an emulsifier containing a salt of a compound and thus preparing a first diene-based rubber polymer; enlarging the first diene-based rubber polymer using the acrylic coagulant and thus preparing a second diene-based rubber polymer; and graft-polymerizing an aromatic vinyl-based monomer and a vinyl cyanide-based monomer to the second diene-based rubber polymer and thus preparing a graft polymer.

Provided is a method of preparing a graft polymer, which includes: polymerizing a monomer mixture comprising a carboxylic acid monomer and methyl acrylate, wherein the carboxylic acid monomer is included at 1.5 to 2.5 wt %, and thus preparing an acrylic coagulant having an average particle diameter of 60 to 70 nm; polymerizing diene-based monomers in the presence of an emulsifier containing a salt of a compound and thus preparing a first diene-based rubber polymer; enlarging the first diene-based rubber polymer using the acrylic coagulant and thus preparing a second diene-based rubber polymer; and graft-polymerizing an aromatic vinyl-based monomer and a vinyl cyanide-based monomer to the second diene-based rubber polymer and thus preparing a graft polymer.