Editing Soap (section)

===Non-toilet soaps===
So-called [[metallic soap]]s are key components of most lubricating [[grease (lubricant)|greases]] and thickeners.<ref name=UllSoap>{{cite encyclopedia |author=Klaus Schumann |author2=Kurt Siekmann |chapter=Soaps |encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry |year=2005 |publisher=Wiley-VCH |location=Weinheim |doi=10.1002/14356007.a24_247 |isbn=978-3527306732}}</ref> A commercially important example is [[lithium stearate]]. Greases are usually [[emulsion]]s of [[calcium stearate|calcium soap]] or [[lithium soap]] and [[mineral oil]]. Many other metallic soaps are also useful, including those of [[aluminium]], [[sodium]], and mixtures thereof. Such soaps are also used as thickeners to increase the [[viscosity]] of oils. In ancient times, lubricating greases were made by the addition of [[Lime (material)|lime]] to [[olive oil]], which would produce calcium soaps.<ref>{{cite encyclopedia |author=Thorsten Bartels |display-authors=etal |chapter=Lubricants and Lubrication |encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry |year=2005 |publisher=Wiley-VCH |location=Weinheim |doi=10.1002/14356007.a15_423 |isbn=978-3527306732}}</ref> Metal soaps are also included in modern artists' [[oil paint]]s formulations as a [[rheology]] modifier.<ref>{{cite web|url=http://cool.conservation-us.org/waac/wn/wn23/wn23-3/wn23-304.html|title=A Brief History of Aluminum Stearate as a Component of Paint|last=S.|first=Tumosa, Charles|date=2001-09-01|website=cool.conservation-us.org|language=en|access-date=2017-03-17|url-status=live|archive-url=https://web.archive.org/web/20170318085239/http://cool.conservation-us.org/waac/wn/wn23/wn23-3/wn23-304.html|archive-date=2017-03-18}}</ref> Metal soaps can be prepared by neutralizing fatty acids with metal oxides:
:2 RCO<sub>2</sub>H + CaO → (RCO<sub>2</sub>)<sub>2</sub>Ca + H<sub>2</sub>O

A cation from an [[organic base]] such as [[ammonium]] can be used instead of a metal; ammonium [[nonanoic acid|nonanoate]] is an ammonium-based soap that is used as an herbicide.<ref name="ammonium">{{cite web |url=https://www3.epa.gov/pesticides/chem_search/reg_actions/registration/fs_PC-031802_01-Nov-06.pdf |title=Ammonium nonanoate (031802) Fact Sheet |website=epa.gov |date=2006-09-21 |access-date=2022-08-15 |archive-date=2022-11-16 |archive-url=https://web.archive.org/web/20221116165514/https://www3.epa.gov/pesticides/chem_search/reg_actions/registration/fs_PC-031802_01-Nov-06.pdf |url-status=live }}</ref>

Another class of non-toilet soaps are [[resin soap]]s, which are produced in the [[paper industry]] by the action of tree rosin with alkaline reagents used to separate cellulose from raw wood. A major component of such soaps is the sodium salt of [[abietic acid]]. Resin soaps are used as emulsifiers.<ref>{{cite book |doi=10.1002/14356007.a23_073 |chapter=Resins, Natural |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2000 |last1=Fiebach |first1=Klemens |last2=Grimm |first2=Dieter |isbn=3-527-30673-0 }}</ref>