| 摘要 |
<p>PURPOSE:To allow a water-absorptive layer to become loose from a substrate to fill slots in order not to permit passage of water by providing on one side of the substrate a water-absorptive swelling layer which contains a mixture of a fusible resin and a highly water-absorptive resin both in powder form. CONSTITUTION:A powder mixture 52 obtained by mixing a fusible resin and a highly water-absorptive resin both in powder form is applied to a substrate 51 by thermocompression bonding. Thermocompression bonding causes the fusible powder resin to melt and adhere to the substrate. The water-absorptive layer thus formed should preferably have a thickness in the range of 0.1-0.5 mm. The ratio in which the fusible powder resin is mixed with the highly water- absorptive powder resin should preferably be in the range of 1/1 to 1/2. The preferable temperature for the thermocompression bonding is in the range of 100 to 200 deg.C. If this temperature is lower than 100 deg.C, there is possibility of blocking occurring during storage, since a fusible resin with a melting point below 100 deg.C needs to be selected. If the bonding temperature is above 200 deg.C, it becomes possible that the fusible powder resin adheres to the substrate 51 so firmly as not to easily allow the highly water-absorptive resin to come off in the face of water.</p> |
