| 摘要 |
PROBLEM TO BE SOLVED: To obtain a saponified ethylene-vinyl acetate copolymer compsn. which is excellent in long-run properties in melt molding and gives a molded item free from fish eyes or streaks and excellent in physical properties such as transparency by compounding a saponified ethylene-vinyl acetate copolymer (A) with a boron compd. (B), sodium acetate (C) and magnesium acetate (D) in a specified ratio. SOLUTION: Ingredient A has an ethylene content of 20-60 mol.% and a degree of saponification of vinyl acetate units of 90 mol.% or higher. Boric acid and borax are suitable as ingredient B. 100 pts.wt. ingredient A washed with water in advance is immersed in or treated under stirring with 200 pts.wt. aq. soln. contg. 0.0001-1.5 wt.% (in terms of boron) ingredient B, 0.001-0.1 wt.% (in terms of metal) ingredient C and 0.0005-0.1 wt.% (in terms of metal) ingredient D for 2-10 hr at 10-50 deg.C, filtered, and dried with a dryer at 90-120 deg.C for 5-48 hr, thus giving a compsn. A. Pref., the wt. ratio of B/Na in the compsn. is adjusted to 0.5-10.0 by adjusting the contents of ingredients B and C. |
