Lg Chem, Ltd

Min Jeong Kang

Joong Chul Lim

Hyun Kyou Ha

Yang Jun Jeon

Jin Hyuck Ju

Kyung Seog Youk

Hyun Min Lee

Heung Kwon Bae

Jung Rae Lee

The present disclosure provides a method for preparing a polymerization initiator composition, including (a) a step of mixing water and a water-soluble initiator to prepare an aqueous initiator solution having a concentration of 1 to 10%; and (b) a step of activating the aqueous initiator solution, wherein the step of activating is performed by (b-1) a step of heat treating the aqueous initiator solution for 0.5 to 4.5 hours at a temperature of 48 to 62° C.; and (b-2) a step of treating the aqueous initiator solution to achieve pH of 1 to 7, where the steps above are performed in no particular order.

Method for preparing polymerization initiator composition

The present disclosure provides a composition for preparing a vinyl chloride-based polymer, including a vinyl chloride-based first seed; a vinyl chloride-based second seed; an initiator composition including a water-soluble initiator and an oil-soluble initiator; a reducing agent; and a vinyl chloride-based monomer, wherein a metal catalyst is not included in the composition, and a method for preparing a vinyl chloride-based polymer using the same.

Composition for preparing vinyl chloride-based polymer and method for preparing vinyl chloride-based polymer using the same

The present invention relates to a method for preparing vinyl chloride-based polymers, which is provided to improve polymerization productivity. An initial stage polymerization temperature is raised, the temperature is then lowered at a certain cooling rate from the time when an initial target polymerization temperature until a polymerization reaction is completed, and thus, a vinyl chloride-based polymer with excellent physical properties may be prepared while reducing a polymerization time and improving polymerization productivity even without additionally installing a polymerization reactor and heat removal equipment.

Method for preparing vinyl chloride-based polymer

The present invention provides a method for preparing a vinyl chloride-based polymer and a vinyl chloride-based polymer prepared thereby, the method comprising a step for performing suspension polymerization of a monomer for preparing a vinyl chloride-based polymer in the presence of a polymerization initiator, a dispersant, and water soluble cellulose ether, wherein the dispersant includes a mixture of two or more kinds of polyvinyl alcohol having different degrees of saponification, and the mole average degree of saponification of the polyvinyl mixture is from 76 mol % to 80 mol %, and the water soluble cellulose ether has a gel point of 60&#xb0; C. to 90&#xb0; C. and is added before the initiation of polymerization or at a time in which the polymerization conversion rate is 70% or less.

Method for preparing vinyl chloride-based polymer, and vinyl chloride-based polymer prepared thereby

The present invention relates to a method of preparing a vinyl chloride-based polymer, and more specifically, to a method comprising the steps of, (S1) preparing a mixture in which a first protective colloid auxiliary agent and a chain regulator are mixed; (S2) preparing a second protective colloid auxiliary agent including the chain regulator activated by stirring the mixture prepared in step (S1); and (S3) performing polymerization by adding a vinyl chloride-based monomer and a polymerization initiator in the presence of the second protective colloid auxiliary agent prepared in step (S2).

Method of preparing vinyl chloride-based polymer

The present invention provides a method for preparing a vinyl chloride-based polymer comprising performing suspension polymerization of vinyl chloride-based monomer, wherein an aromatic hydrocarbon-based compound is added when a pressure change is 0.5 to 1.5 kg/cmwith respect to an equilibrium pressure at a polymerization temperature in a polymerization reactor after the vinyl chloride-based monomer is added to the polymerization reactor, wherein the aromatic hydrocarbon-based compound comprises a reactive functional group having an intracarbon double bond and a hydroxyl group; and a vinyl chloride-based polymer prepared by the method and having a high polymerization degree and excellent fusion processability.

Method for preparing vinyl chloride-based polymer and vinyl chloride-based polymer prepared by the same

The present invention relates to a method for preparing a vinyl chloride copolymer having good heat resistance and a vinyl chloride copolymer produced by the same. In the preparation method, by not injecting an N-substituted maleimide based compound used as a comonomer together with a vinyl chloride monomer at one time in a pre-polymerization step, but in division in a specific ratio, a copolymer with a uniform distribution of the N-substituted maleimide based compound and the vinyl chloride monomer may be easily prepared, and the vinyl chloride copolymer may have good heat resistance. Accordingly, the preparation method of a vinyl chloride copolymer and the vinyl chloride copolymer according to the present invention may be easily applied to industries requiring the copolymer, particularly industries requiring a resin having good heat resistance as well as industries using a vinyl chloride resin.

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Daejeon, South Korea

Min Jeong Kang