| 摘要 |
PURPOSE:To stably and efficiently produce a polyvinyl acetal-based porous material having modified surface and no cold feeling to skin. CONSTITUTION:In reacting a reaction stock solution obtained by mixing a polyvinyl alcohol with an aldehyde, an acid and a pore forming material, the stock solution is made to react in a contact state with paper. After the reaction is completed, the aldehyde, the acid and the pare forming agent unreacted are removed and the paper is eliminated to give a polyvinyl acetal-based porous material. In the above-mentioned method, the surface of the paper is at least partially provided with a carbonate or hydrogencarbonate to evolve a carbon dioxide gas by reaction with the acid. |
