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Patent Searching and Data


Title:
METHOD FOR PRODUCING VINYL CHLORIDE POLYMER
Document Type and Number:
Japanese Patent JPH07188315
Kind Code:
A
Abstract:

PURPOSE: To obtain a polymer large in a gelling and melting rate and a bulk density and good in moldability by polymerizing vinyl chloride monomer, etc., while raising the polymerization temperature with time, and subsequently adding a chain transfer agent, when the polymerization reaches a specific polymerizatior conversion.

CONSTITUTION: Vinyl chloride monomer or a mixture containing the vinyl chloride monomer as a main monomer and further another copolymerilzable monomer (e.g. ethylene) is polymerized in the presence of the partially saponified product of polyvinyl acetate and a polymerization initiator in an aqueous medium, while the polymerization temperature is raised within a raising change width of 2-35°C with time in a period occupying ≥50% of the whole period during when the polymerization reaction proceeds. When the polymerization conversion reaches 40-70% based on the charged vinyl chloride monomer, a chain transfer agent (e.g. 2-mercaptnethanol) is added to the polymerization system to obtain the objective vinyl chloride polymer large in a gelling and melting rate and a bulk density and excellent in moldability.


Inventors:
YAMAMOTO RYOSUKE
MORIMOTO TADASHI
Application Number:
JP1993000333230
Publication Date:
July 25, 1995
Filing Date:
December 27, 1993
Export Citation:
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Assignee:
MITSUBISHI CHEM CORP
International Classes:
C08F14/06; C08F2/00; C08F2/18; C08F2/22; C08F2/24; C08F2/38; C08F14/00; (IPC1-7): C08F2/38; C08F2/00; C08F2/18; C08F2/24; C08F14/06
Attorney, Agent or Firm:
長谷川 曉司