Isobutyl stearate

Isobutyl stearate (CAS 646-13-9) is a fatty acid ester produced by reacting stearic acid with isobutanol. It is sold under trade names including Estol 1476 and Emerest 2324, and is also identified as isobutyl octadecanoate. No E-code applies to this ingredient.

In personal care formulations, isobutyl stearate functions as an emollient and skin-conditioning carrier, reducing drag in leave-on products by forming a non-occlusive lipid layer. In plastics processing, it acts as a plasticizer and internal lubricant, improving polymer flow during extrusion. Metalworking lubricant formulators use it as a base carrier for active additives due to its film-forming properties.

Isobutyl stearate is subject to REACH registration requirements for EU supply. Procurement teams should confirm supplier documentation including Safety Data Sheets and certificates of analysis specifying acid value, iodine value, and ester content. It is typically available in drums and IBC containers.