| 摘要 |
PURPOSE:To enhance rust-resistance by a method wherein, after a synthetic resin coupling type magnet is brought into contact with a solution having pH of the specific value or higher, a wet plating or an electrodeposition coating is conducted thereon. CONSTITUTION:After a molded body, mainly composed of magnetic powder indicated by R-T-B (R indicates Nd or a part of which is substituted with a rare-earth element, T indicates Fe or a part of which is substituted with transition metal) and synthetic resin which is a bonding agent, has been brought into contact with a solution containing pH of 6.0% or more, a wet plating or an electrodeposition coating is conducted. Phenol resin, epoxy resin, melamin resin and the like are enumerated as the thermosetting resin used for bonding agent, and also polyamide such an nylon 6, nylon 12, polyolefin such as polyethylene, polypropylene, polyvinyl chloride, polyester, polyphenylene sulpfide and the like are named as thermoplastic resin. There are water, sodium hydroxide, potassium hydroxide and the like as a solution containing pH of 6.0% or more, and the solution containing a corrosion-preventing agent is more preferable. Alkali silicate solution and the like is named as the corrosion-preventing agent. |
