Stearic acid and its derivatives
Stearic acid, octadecyl acid, melting point 69.6 ° C, boiling point 376.1 ° C, relative density 0.9408, slightly soluble in water. Industrial products are generally white or yellowish granules or chunks, a mixture of stearic acid and palmitic acid, and contain a small amount of oleic acid, a slightly fatty odor.


The saponified product of stearic acid emulsifies in the cream, making it a stable white cream. Stearic acid is also the main raw material for the manufacture of emulsions. Stearic acid soap esters are more widely used in the cosmetic industry.


Cetyl alcohol


Cetyl alcohol is also known as hexadecanol or palmitol. It was originally prepared by saponification of cetyl wax. White crystals. The density is 0.811. 49 ° C melting point. The boiling point of 344 ° C.


Cetyl alcohol is insoluble in water, soluble in ethanol, chloroform, and ether, but has a certain water absorption. It can be used as an emulsion-type matrix to mix with an oily matrix (such as petrolatum) to increase its water absorption and contact with water or aqueous liquid. At the time, the W/O type emulsion base was formed after water absorption under sufficient stirring. Stabilizes and thickens in the O/W emulsion base oil phase.


Palmitate


Commonly used are isopropyl palmitate (IPP) and isooctyl palmitate, which is one of the raw materials widely used in cosmetics in China since the 1980s. Both are colorless, odorless and odorless oily liquids, soluble in ethanol, ether, chloroform, and the like. These raw materials have good mutual solubility to oils and fats, low viscosity, good lubricity and spreadability.


Polysiloxane
Polysiloxane is an abbreviation for polyorganosiloxane. It is a kind of polymer with repeating Si-O bond as the main chain and direct connection of organic groups on silicon atom. Its general formula is [RnSi4-n/2] m, wherein R represents an organic group such as a methyl group, a phenyl group or the like; n is the number of organic groups attached to the silicon atom (between 1 and 3); m is a degree of polymerization (m is not less than 2). Polysiloxane refers to polydimethylsiloxane and a series of derivatives thereof, and is an odorless, tasteless and non-irritating oily raw material. Polysiloxane has good lubricity, gas permeability and stability, and also has certain antistatic and anti-ultraviolet effects.


The common silicone component of cosmetics is polydimethylsiloxane, also known as dimethyl silicone oil. It is a linear polymer with siloxane as the skeleton. It is a non-oily synthetic oil. A transparent liquid or viscous liquid with different viscosities depending on the degree of polymerization. It is basically odorless, insoluble in water and ethanol, and soluble in organic solvents such as carbon tetrachloride, benzene, chloroform, diethyl ether and toluene. Dimethicone has good thixotropy, is easy to spread on the skin, and forms a hydrophobic film after application, thereby increasing the water resistance of the cream without causing greasy feeling. It also has good compatibility with the skin, odorless, tasteless, non-irritating and safe. In addition, it is often used as a defoaming agent in the production of cosmetics.