| 摘要 |
<p>PURPOSE:To obtain a multi-layer sheet with one side which does not allow water infiltration and the other side which allows water solution or dispersion if permitted to come in contact with water by using a film or a sheet which becomes swollen or allows water dispersion or solution as a base and applying a fluorine or silicon water repellent to the one side of the base. CONSTITUTION:This multi-layer sheet consists of a film or a sheet which becomes swollen in water or allows water dispersion of solution as a base. A fluorine or a silicon water repellent is coated on one side of the base. The recommended materials used for the base are such as not suffering from a change of properties to water insolubility due to drying and thermal treatment after coating. For example, polyvinyl pyrolidone, polyacrylamide, poly(metha) acrylic acid and its salts, maleic anhydride copolymer and its salts are cited. The fluorine water repellent is such as tetrafluoroethylene emulsified polymer or perfluorovinylether polymer. The silicon water repellent is a reactive silicon compound.</p> |
