| 摘要 |
PROBLEM TO BE SOLVED: To obtain a saponified ethylene-vinyl acetate copolymer (EVOH) soln. excellent in solubility and low-temp. stability by dissolving EVOH having a specific water content in a solvent. SOLUTION: This soln. is prepd. by dissolving a water-contg. EVOH, prepd. by causing EVOH having an ethylene content of 60 mol.% or lower and a degree of saponification of 90 mol.% or higher to absorb water to a water content of 10 wt.% or higher, in a solvent contg. at least 20 wt.% 4C or lower alcohol, pref. in a mixed solvent comprising 75-20 wt.% water and 25-80 wt.% alcohol. Based on 100 pts.wt. EVOH, 0.1-20 pts.wt. boric acid compd. [e.g. boric acid or sodium borate (such as sodium metaborate, sodium diborate, sodium tetraborate, or sodium pentaborate)] is added to the soln. in order to further improve its stability. The soln. with a concn. of 1-50 wt.% is applied to a susbtrate having a thickness of 10-1,000μm to form thereon a coating film having a thickness of 0.5-500μm, thus imparting gas barrier properties to the substrate.
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