Title: Process for devolatilizing molten oxymethylene polymer
Application Number: 86107755 Application Date: 1986.11.12
Publication Number: 1011970 Publication Date: 1987.07.08
Approval Pub. Date: 1991.04.10 Granted Pub. Date: 1991.04.10
International Classifi-cation: B29B7/84;C08G2/28
Applicant(s) Name: Celanese Corp. Address:
Inventor(s) Name: Douglas W. Steele;George S. Nash;John W. Dorsey
Attorney & Agent: ZHOU ZHONGQI DAI ZHENXIU
Abstract:
    A process is provided for removing volatile materials from a molten oxymethylene polymer, according to which the molten polymer is passed through a rotating disk polymer processor having at least three stages; a first devolatilization stage, then a stabilization stage and then a second devolatilization stage. The molten polymer in the first devolatilization stage is maintained at a temperature above its melting point in the temperature range of from about 160 DEG C. to about 220 DEG C. and at a vapor space pressure of from about 0.1 to about 300 Torr. The polymer in the stabilization stage is maintained in the molten state at a temperature of from 160 DEG C. to about 220 DEG C. The polymer in the second devolatilization stage is maintained in the molten state at a temperature of from about 160 DEG C. to about 190 DEG C. and at a vapor space pressure of from about 0.1 to about 100 Torr.
Time: 4