Title:
MANUFACTURE OF OXYMETHYLENE COPOLYMER MOLDING MATERIAL CONTAINING SMALL QUANTITY OF RESIDUAL FORMALDEHYDE
Document Type and Number:
Japanese Patent JPS5543191
Kind Code:
A
Abstract:
Oxymethylene copolymers molding compositions with low portions of residual formaldehyde are produced by heating the polymerizate melts treated with chemical stabilizers in an apparatus in which there are continuously presented new polymerizate surfaces under reduced pressure. The heating of the polymerizate melt takes place in a thin layer evaporator for highly viscous media during an average residence time of 30 to 120 seconds at an average rate of shear between 500 and 2000 s-1 and at a pressure Pabs of at most 150 mbar. The escaping gases and vapors are drawn off countercurrent to the polymerizate melt.
Inventors:
HERUBERUTO AMAN
GERUHARUTO MORUROTSUKU
HERUMUUTO TORAUTOBUAIN
GERUHARUTO MORUROTSUKU
HERUMUUTO TORAUTOBUAIN
Application Number:
JP11943779A
Publication Date:
March 26, 1980
Filing Date:
September 19, 1979
Export Citation:
Assignee:
DEGUSSA
International Classes:
C08G2/18; C08G2/00; C08G2/28; C08G2/36; C08L51/04; (IPC1-7): C08G2/08