METHOD FOR PRODUCING N-VINYL COMPOUND-BASED POLYMER

• Main Authors: KURIYAMA TOSHIAKI, INUI YASUKO
• Format: Patent
• Language: English
• Published: 23.04.2002
• Edition: 7
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

PROBLEM TO BE SOLVED: To provide a both a method for reducing a residual monomer, capable of rapidly reducing the residual monomer without a problem such as an ash increase, in removing the residual monomer from an N-vinyl compound-based polymer, and a method for producing a solution or powder of an N-vinyl compound-based polymer having adjusted pH without reduction in pH of an aqueous solution or a dried substance of the N-vinyl compound-based polymer with time. SOLUTION: An organic acid having >=140 deg.C boiling point under normal pressure is added to an N-vinyl compound-based polymer aqueous solution. The N-vinyl compound-based polymer aqueous solution having pH <7.0 is neutralized with an organic base and adjusted to a proper pH. Furthermore, these operations are carried out in <=5 vol.% oxygen concentration in a vapor phase in a reactor.