| 摘要 |
PURPOSE:To readily and surely obtain the subject fine powder without impairing a polymer structure by vibrating gel-like precipitation of a metallic ion crosslinking-type polymer to form sol-like ultrafine particle precipitation and then atomizing and drying the precipitation. CONSTITUTION:A polymer raw material capable of crosslinking by reacting with a metallic ion in an aqueous solution of hydroxide of alkali metal and/or alkaline earth metal (e.g. polyacrylic acid) is made to react with a metallic ion (preferably Na<+> or K<+>), preferably in a ratio of 0.1-20 equivalent metallic ion based on 1 equivalent carboxylic group of polymer raw material to deposit and precipitate a metallic ion-crosslinked type polymer. Then, the gel-like precipitation of the polymer is vibrated to form sol-like ultrafine particle precipitation and this ultrafine particle precipitation is atomized and dried by a method comprising drawing up the precipitation by pump, etc., and then spraying into hot air stream. Furthermore, as a vibration condition, vibration by ultrasonic wave having 20-50KHz frequency is preferable. |
