The study and development of permanent hair dyeing, agent especially about the new harmless ones such as iron salt, plant extracting and Melanin hair dyeingagent are reviewed.
综述了永久性染发剂的研究开发，尤其新型无毒染发剂如铁盐染发剂，植物萃取物染发剂和黑色素类染发剂等。
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The results showed that the dyeing brightening agent can brighten and deepen direct and acid dyes, but it has no effect on metal complex dyes and its brightening effect disappears after being baked.