| 摘要 |
PROBLEM TO BE SOLVED: To obtain a casing made of an unmodified cellulose having improved resistance to adhesion by including an olefinic oxide polymer having high molecular weight. SOLUTION: A sufficient amount of a poly(ethylene oxide)(PEO) having a molecular weight of <6,000,000 is included in a casing to improve the resistance to adhesion and decrease the tendency of sticking or fusing the inner faces of the casing in the case of expanding the casing from a flat state. Preferably, a PEO solution, cellulose pulp, water and N-methyl-morpholine-N-oxide(NMMO) cellulose solvent are put into a mixing vessel 14 to form a premix composed of about 10-15 wt.% cellulose, 60-70 wt.% NMMO, 20-25 wt.% water and 0.4-2.0 wt.% PEO and the premix is passed through a heating vessel 16 and a die 20, extruded in the form of a tube 22, passed through a regeneration tank 24 and a glycerol solution 30 and dried with a drier 32 while inflating the tube to obtain a tubular film 34.
|
