| 摘要 |
PROBLEM TO BE SOLVED: To obtain a packaging material for a planographic printing plate excellent in fog resistance and gum removability for a planographic printing plate, and useful for productivity, chip resistance and storage property while maintaining recycling suitability, by preparing the material substantially containing no aluminum but satisfying specified conditions according to JIS-Z-0208. SOLUTION: This packaging material does not substantially contain aluminum and has <=10 g/m2.24 h permeability of water vapor and <=0.3% light shielding property at 200 to 800 nm wavelength specified by JIS-A-0208. The material does not substantially contain aluminum means that the material has no aluminum foil layer or is not treated by aluminum vapor deposition or the like. The material may contain a minute amt. of aluminum as far as it can be recycled. The material preferably has >=100 g shear strength specified by JIS-P-8116, and its weight per unit area is preferably <=80 g/m2 so as to obtain proper physical strength and rigidity. Moreover, the pH of the innermost layer of the packaging material is almost neutral. |
