| abstract |
PURPOSE: To produce the titled membrane capable of releasing a liquid active material over a long period of time, by coating a support with a soln. obtd. by dissolving a polymer and a liquid active material in a specified org. solvent, evaporating the solvent and laminating a polymer film thereon. n CONSTITUTION: At least 30wt% polymer (A) such as PS and not more than 70wt% active material (B) (e.g. naled), which is a liquid at room temp. and has a solubility of not more than 5pts.wt. per 100pts. wt. component A, are dissolved in an org. solvent (e.g. chloroform) in such a proportion as to give a concn. of 10W40wt%, said solvent being capable of dissolving components A and B and being more volatile than component B. The resulting soln. is applied to a support in a coating thickness of 10W500μ and evaporated at a temp. not higher than the b.p. of the solvent in an atmosphere having humidity of 60% or above to form a polymer layer in which component B in the form of liquid droplet is enclosed in a lot of closed-cell micropores. While the soln. is tacky, a polymer film such as PE film is laminated on the polymer layer. n COPYRIGHT: (C)1984,JPO&Japio |