| 摘要 |
PROBLEM TO BE SOLVED: To obtain a gel having many micropores by applying an aqueous dispersion of fine particles on a support to form a layer of the dispersion, agglomerating the fine particles by destabilizing the dispersion before the water is completely evaporated, and drying the layer. SOLUTION: Water and a specified amount of a nonionic emulsifier are fed into a reactor and heated. To the mixture is added, about 25wt.% monomer mixture containing methyl methacrylate, butyl acrylate, styrene or the like is under agitation. Next, a polymerization initiator (e.g. ammonium persulfate) is added to the mixture, and the residual monomer mixture is added thereto. The resulting mixture is agitated for a specified time to prepare an aqueous resin dispersion containing dispersed polymer particles. A thermosensible gelling agent (e.g. ammonium sulfate zinc complex) is added to the dispersion under agitation to prepare an aqueous dispersion for coating. This dispersion is applied to a PET film coated with a primer layer and dried at about 10-98 deg.C to cause gelation of the polymer particles in the dispersion, and the film is dried to obtain a porous filmy gel having many pores having a mean diameter of 500nm or below. |
