noun
metallic soap; soap scum
Technical term for a metal salt of a fatty acid, used in lubricants, stabilizers, etc. Also refers to the insoluble residue (soap scum) formed when soap reacts with hard water minerals.
金属石鹸はプラスチックの安定剤として使われる。
Metallic soaps are used as stabilizers in plastics.
硬水では石鹸が
In hard water, soap turns into metallic soap and precipitates.