| 摘要 |
PROBLEM TO BE SOLVED: To obtain a moistureproof polyvinyl chloride sheet excellent in persistence of heat resistance during sheet processing and free of deterioration of initial discoloration by forming (B) a vinylidene chloride resin layer on at least one surface of (A) a vinyl chloride resin layer comprising (a) a vinyl chloride resin, (b) a calcium compd., (c) a zinc compd. and (d) hydrotalcite. SOLUTION: (B) A vinylidene chloride resin layer is formed on at least one surface of (A) a vinyl chloride resin layer having a thickness of 0.02 to 1mm and a softening temp. of 50 to 80 deg.C, and made of a compsn. comprising (a) 100 pts.wt. vinyl chloride resin of 500 to 1,000 in average degree of polymn., (b) 0.01-2 pts.wt. calcium compd. (e.g. calcium stearate), (c) 0.01-2 pts.wt. zinc compd. (e.g. zinc stearate) and (d) 0.01-5 pts.wt. hydrotalcite of the formula I (wherein W, X, Y and Z satisfy 2W+3X= Y+2Z, provided that 2<=W<=6 and 2<=m<=4). The vinylidene chloride compsn. used for the resin layer (B), the thickness of which is 1 to 500μm, may be a vinylidene chloride resin alone though not particularly limited in so far as the desired moistureproofing properties can be secured.
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