Industry expert Tony O’Lenick explains the difference between a fatty ester and a benzoate ester...
Traditional fatty esters are most commonly made by the reaction of a fatty alcohol and a fatty acid to make an oily material. Benzoate esters are the reaction product of a short aromatic acid (benzoic acid) and a fatty alcohol.
The benzoate ester best known is made by the reaction of a C12-C15 fatty alcohol and benzoic acid. This product was patented in 1981 (US patent 4,275,222, assigned to Scala) and remains an important cosmetic ingredient to this day.
According to Finetex, reports O'Lenick, C12-C15 benzoate is a unique nontoxic, nonirritating, nonsensitizing and noncomedogenic, water-insoluble, readily emulsifiable ester that possesses the following unexpected properties and attributes:
1. Imparts a dry lubricating feel in the presence of large amounts of mineral oil or petrolatum; i.e., "de-oils" mineral oil and "de-greases" petrolatum;
2. Acts as a superior solubilizer of lipophilic cosmetic raw materials, especially sunscreen agents and volatile silicones;
3. Provides a high positive spreading coefficient;
4. Acts as an anti-tack agent, especially in antiperspirant formulations;
5. Acts as a wetting agent and auxiliary suspending agent for water-insoluble powdered products; and
6. Is stable to hydrolysis within a pH range of approximately 2-12.
These multifunctional properties lend themselves to formulating a variety of cosmetic and personal care products, as well as sun care and OTC skin products, all possessing a dry (nongreasy), cosmetically elegant emollient feel.