At present, the silicone oil products commonly used in cosmetics mainly include dimethyl silicone oil, methyl phenyl silicone oil, cyclic silicone oil, hydroxy silicone oil, polyether silicone oil and long-chain alkyl modified silicone oil. The outstanding properties of silicone oil used in cosmetics are mainly waterproof, lubricating, spreading, film-forming and compatibility. Silicone oil has low surface tension, which has a good lubricating effect on the skin. Combined with the appropriate viscosity, the other components of the cosmetic can be easily dispersed and form a fine and uniform skin protective film on the skin to prevent the skin from drying and wrinkling. , but also to ensure the normal breathing of the skin and to treat dermatitis and eczema. The protective film can also prolong the effect of active ingredients in cosmetics, and effectively prolong the effect of nutritional creams and medicinal creams. Silicone oil has good compatibility with most cosmetic additives. Good compatibility and compatibility make cosmetic formulations have more choices, which is convenient for the development of different types of advanced cosmetics. The detackifying properties of silicone oil enable it to be combined with petrolatum, paraffin, beeswax, lanolin, etc. to obtain non-sticky products.
Volatile silicone oil can endow cosmetics with properties such as quick drying, smoothness and antifouling; methylphenyl silicone oil has a certain effect of absorbing ultraviolet rays, and phenyl can enhance the compatibility of silicone oil with other oil compounds; long-chain alkyl modified silicone oil It has good gloss, increases the brightness and gloss of cosmetics, and has better compatibility with carbon-based compounds; hydroxy silicone oil can improve the compatibility and compatibility with other cosmetic raw materials; polyether silicone oil is suitable for water-based Cosmetics have good compatibility with hydrophilic compounds and have a certain emulsifying effect, and can be used as emulsifiers for cream products or lotions.
The following are some applications of silicone oil in cosmetics:
Antiperspirants: Cyclic siloxanes have some desirable properties that make them ideal components in antiperspirants. The most important things are volatility and low heat of vaporization, cyclic siloxanes are volatile at room temperature and even faster at skin temperature. When used as a base fluid in an antiperspirant, the active ingredient is brought to the skin as a smooth film, and then evaporates, leaving no residue, no discomfort and good antiperspirant effect, making its performance greatly improved . In aerosol antiperspirants, cyclic siloxanes can eliminate valve blockage and reduce the stickiness of antiperspirant salts without staining.
Deodorants: Typical deodorants today use up to 80% ethanol or propylene glycol, or a combination of both, and their components have many disadvantages. Ethanol is drying to the skin but can cause varying degrees of irritation. Skin irritation or irritation can also occur, especially in formulations in excess of 10 %, while liquid silicones are essentially non-toxic and do not sting on injured and worn skin. Therefore, the deodorant made of silicone oil and cyclic siloxane can overcome the above-mentioned characteristics, and at the same time improve the lubricity of the preparation, make the deodorant extra soft, and control the production of apocrine substances in the human body, thereby achieve the purpose of deodorization. Dimethicone polyol copolymers can improve the compatibility of many common deodorant raw materials with other ingredients.
Sunscreen: When the human epidermis is stimulated by ultraviolet rays, the oxidase (tyrosinase) in the pigment cells of the basal layer of the epidermis is active, and tyrosine, one of the amino acids, is oxidized and polymerized to generate melanin, which is sent to the epidermis to make the skin. Blackening, while silicone sunscreens are not irritating to the skin, they are not prone to chemical changes when exposed to heat and light, and are easily adsorbed on the skin, which can prevent pigmentation caused by sun exposure and prevent tanning. Normal sunscreen is fine. For example, sunscreens containing silicone oil will not be washed off by sea bathing and sweating, and it can prevent the harm of ultraviolet rays. It is best to add methyl phenyl silicone oil into the sunscreen agent, because phenyl has a certain ability to absorb ultraviolet rays, and its sun protection performance is better than that of methyl silicone oil. Linear alkyl silicone oils are also valuable formulations in the manufacture of sunscreens, improving their lubricity and hydrophobicity.