The present invention relates to a method for preparing a vinyl chloride-based polymer, including: bulk polymerizing a vinyl chloride-based monomer in a polymerization reactor to prepare a vinyl chloride-based polymer; and adding water and vapor to the polymerization reactor, and heating to remove an unreacted vinyl chloride-based monomer, wherein an addition amount of the water is 0.500 to 5.000 parts by weight based on 100 parts by weight of the vinyl chloride-based polymer.

The present invention relates to a method for preparing a vinyl chloride-based polymer, including: bulk polymerizing a vinyl chloride-based monomer in a polymerization reactor to prepare a vinyl chloride-based polymer; and adding water and vapor to the polymerization reactor, and heating to remove an unreacted vinyl chloride-based monomer, wherein an addition amount of the water is 0.500 to 5.000 parts by weight based on 100 parts by weight of the vinyl chloride-based polymer.

The present invention relates to a process for removing hydrocarbons comprising the steps of: (A) passing a stream of a solution into a separator wherein a liquid phase comprising polymer and a vapour phase coexist; (B) withdrawing a vapour stream and a concentrated solution stream from the separator; (C) passing at least a part of the vapour stream into a first fractionator; (D) withdrawing a first overhead stream and a first bottom stream from the first fractionator; (E) passing the first overhead stream to a second fractionator; (F) withdrawing a second overhead stream and a second bottom stream from the second fractionator; (G) passing the second overhead stream to a third fractionator; (H) withdrawing a third overhead stream and a third bottom stream from the third fractionator;
characterised in that at least a part of the third bottom stream is withdrawn as a purge stream.

Process for the removal of volatile compounds from a tackifier comprising a resin with repeating units of formula I wherein R.sup.1 is a linear or branched alkylen group with 1 to 10 carbon atoms and R.sup.2 is a linear or branched, saturated or unsaturated N aliphatic hydrocarbon group with up to 20 carbon atoms, and optionally a plasticizer, wherein the tackifier is passed through at least one evaporator as film and the volatile compounds are removed from the film. ##STR00001##

The method produces hollow particles which have a high void ratio, which can reduce the residual amount of a sparingly water-soluble solvent used in the production process, and which are less likely to collapse. The method for producing hollow particles which comprise a shell and a hollow portion and which have a void ratio of 50% or more and 90% or less, wherein a suspension treatment of a mixture liquid containing a polymerizable monomer for shell, a polar resin, a hydrocarbon solvent, a sparingly water-soluble inorganic metal salt as a dispersant, and an aqueous medium is carried out to prepare a suspension in which droplets of a monomer composition containing the polymerizable monomer for shell, the polar resin and the hydrocarbon solvent are dispersed in the aqueous medium; a polymerization reaction of the suspension is carried out; and the hydrocarbon solvent is removed from the obtained hollow particles.

The method produces hollow particles which have a high void ratio, which can reduce the residual amount of a sparingly water-soluble solvent used in the production process, and which are less likely to collapse. The method for producing hollow particles which comprise a shell and a hollow portion and which have a void ratio of 50% or more and 90% or less, wherein a suspension treatment of a mixture liquid containing a polymerizable monomer for shell, a polar resin, a hydrocarbon solvent, a sparingly water-soluble inorganic metal salt as a dispersant, and an aqueous medium is carried out to prepare a suspension in which droplets of a monomer composition containing the polymerizable monomer for shell, the polar resin and the hydrocarbon solvent are dispersed in the aqueous medium; a polymerization reaction of the suspension is carried out; and the hydrocarbon solvent is removed from the obtained hollow particles.

Provided are a method of purifying an alpha-olefin and a composition for purifying an alpha-olefin therefor. More specifically, a method of purifying an alpha-olefin having an excellent effect of removing impurities in the alpha-olefin and a composition for purifying an alpha-olefin therefor are provided.

Provided are a method of purifying an alpha-olefin and a composition for purifying an alpha-olefin therefor. More specifically, a method of purifying an alpha-olefin having an excellent effect of removing impurities in the alpha-olefin and a composition for purifying an alpha-olefin therefor are provided.

Provided is a new method that effectively reduces odor components that are present in a hydrogenated petroleum resin, and adjusts a softening point to an appropriate range for exhibiting an adhesive performance. A method for deodorizing a hydrogenated petroleum resin, includes stripping a hydrogenated petroleum resin at a gas flow rate of 1 to 45 VVM.

Provided is a new method that effectively reduces odor components that are present in a hydrogenated petroleum resin, and adjusts a softening point to an appropriate range for exhibiting an adhesive performance. A method for deodorizing a hydrogenated petroleum resin, includes stripping a hydrogenated petroleum resin at a gas flow rate of 1 to 45 VVM.