| 摘要 |
PURPOSE: To obtain a sustained release agent capable of being applied to a system requiring high pressure, durability under the high pressure, extremely low abrasion, and high smoothness to contact by impregnating an active ingredient into solid elastic particles having substantially opened net structure pores lead to the outsides. CONSTITUTION: This sustained release agent is obtained by dissolving an ethylene-propylene-dienic elastomer prepolymer (preferably having a mol.wt. of 1000-30000 and an iodine value of 5-50) in a water-immiscible liquid inactive to the prepolymer, dispersing the obtained homogeneous solution in an aqueous solution, polymerizing the prepolymer in the suspension to form solid elastic polymer particles containing water-immiscible liquid seeds, recovering the particles, extracting the water-immiscible liquid seeds, and subsequently impregnating the particles with an active ingredient. The solid elastic particles has preferably an average particle diameter of 1-200μm, a total volume of 0.01-4.0cm<3> , a surface area of 1-500m<2> /g, and an average pore diameter of 0.001-3.0μm.
|
