Liquid esters are of interest in the formulation of personal care products for use as emollients, moisturizers, conditioners and aesthetic modifiers. The ability to control melting point is very useful in formulating skin care products. The options to make liquid products in the past were principally accomplished by (1) incorporation of unsaturation or (2) branching into the molecule. One particular branch type, the Guerbet branch is very effective for liquidity, but very expensive. Other less expensive branched materials and propoxylated linear esters were evaluated to determine their effectiveness in lowering melting point.
Background and Introduction
The ability to manufacture liquid, dry, cost effective esters for use in personal care products has long been a goal for manufacturers of cosmetic ingredients. This need has increased dramatically with the increased regulation on D5 in cosmetic products.
A great deal of work has been done in recent times to prepare liquid esters that provide benefit to hair and skin.
One very important benefit of such a product depending upon the exact structure is providing moisturization for the skin.
One mechanism for emolliency is to deposit of an oil on the skin that acts as a barrier to minimize transepidermal water loss. The process of transepidermal water loss is shown graphically in Figure 1. In this case liquid esters are of interest since they can easily form a thin oily film on the skin.
Esters based upon wax technology generally are neither effective nor have a desirable skin feel. There have been a number of approaches used to obtain liquid esters for use as moisturization agents.
One approach to getting functional liquid products has been the use of unsaturated hydrophobes. These materia ...