Silicone oil raw materials for cosmetics

1. Brief description and classification of cosmetics
The definition of cosmetics - mainly refers to any part of the human body surface, such as hair, face, neck, underarm, nails, lips and teeth, by means of painting, spraying, etc., in order to achieve cleaning, maintenance, beauty, decoration, A chemical industrial product or a fine chemical product for the purpose of changing the appearance and the like for the purpose of maintaining a good state.

There are many kinds of cosmetics, and cosmetics can be divided into the following categories according to the application parts and effects of cosmetics:
Basic cosmetics: refers to products that protect skin, hair, and skin and hair.
Cosmetics: It refers to a product that is used to modify the face, nails, etc. to make it more attractive.
Special-purpose cosmetics: refers to products that have defensive functions on the face, hair, etc., or need to undergo some special physical and chemical treatment, and also have a certain palliative treatment effect.


Second, an important raw material in cosmetics - silicone oil
Silicone has a unique silicon-oxygen bond structure, Si-O-Si, which gives a large bond angle and bond length, and has a small intermolecular force. Unlike ordinary organic molecules, it is easy to crystallize, and therefore, the gas permeability is good. The higher bond energy makes the silicone polymer have outstanding heat resistance and excellent softness; the helical structure of the molecular chain and the longitudinal direction of the methyl group make it have a very low surface tension and good water repellency. Due to the structural specificity, the organosiloxane polymer has a series of properties such as lubrication, softness, water repellency, defoaming, antibacterial and anti-mildew, and is used in personal care products.

The characteristics of silicone-containing cosmetics are mainly as follows:
(1) Good lubricating performance, can form a uniform waterproof protective film after coating the skin, but without any sticky and greasy feeling, the gloss is good.
(2) The performance against ultraviolet radiation is good, and it does not oxidize and deteriorate under ultraviolet irradiation to cause skin irritation.
(3) The antistatic performance is good. The test shows that the static electricity of the skin covered with the silicone skin cream is completely eliminated, and the dustproof effect is obvious.
(4) Good gas permeability, even if a silicone film is formed on the skin, it does not affect the sweat discharge. It has a slow release and aroma effect on flavors and fragrances, and thus has a longer fragrance period.
(5) High stability, chemically inert, no adverse effects on other components of cosmetics, especially active ingredients, and good compatibility.
(6) Non-toxic, odorless, tasteless, does not cause irritation and allergies to the skin, has high safety, and has certain curative effects on certain skin diseases, such as sweaty eczema, neurodermatitis and occupational dermatitis.
Silicone oil is generally divided into ordinary silicone oil and modified silicone oil. So far, silicone products that have been successfully developed for cosmetics include: polydimethylsiloxane, polymethylphenylsiloxane, methylhydrogen silicone oil, polyether. Modified silicone oil, long-chain alkyl modified silicone oil, cyclic polysiloxane, amino modified silicone oil, carboxyl modified silicone oil, polymethylsiloxane emulsion, silicone wax, silicone resin, silicone treated powder And so on.
 (1) Dimethyl silicone oil
Dimethicone is a fully methylated linear siloxane polymer. As the number of carbon atoms increases, the properties of dimethyl silicone oil such as heat resistance and cold resistance decrease, but organic properties such as lubricity and finish are The compatibility of organic resins is increased. Dimethicone itself is colorless, odorless, non-toxic, skin-free, and has a high affinity for the skin. It can be applied to personal care products and has a unique soft and smooth feeling, not greasy, and does not clog pores. Being a carrier gives the personal care product a better texture.

In the cosmetics industry, the excellent properties of dimethyl silicone oil make it excellent in facial and skin products, beauty cosmetics, hair care products, antiperspirants and fragrances.

(2) Polyether modified silicone oil
The molecular structure of the commonly used varieties of polyether modified silicone oil is:
Polyether polysiloxane copolymers are nonionic surfactants commonly known as water soluble silicone oils. It can be used as a plasticizer for wetting agents, emulsifiers, foam regulators, lubricants, fatliquors and hair gel resins with stable performance between pH 1-12. The polyether-modified silicone oil has a hydrophobic group and a hydrophilic group in the molecular structure, so it has the characteristics of a surfactant. It is widely used in polyurethane foam stabilizers, cosmetic raw materials plastic additives, antifogging agents, fiber oil agents, fabric finishing agents, coating additives, defoamers and other fields. It is the largest sales volume of modified silicone oil. Reactive modified silicone oil.

(3) Polymethylphenylsiloxane
Polymethylphenylsiloxane is a low-viscosity colorless transparent liquid with a slight volatility and a high refractive index. It is easily compounded with alcohols and organic components. The molecular structure of polytrimethylphenylsiloxane is:
Polymethylphenylsiloxane has good skin permeability and good skin feel after use. It can impart softness to the skin, deepen hair color and maintain natural luster. It is miscible with aliphatic and aromatic solvents and many commonly used cosmetic materials such as beeswax, lanolin, mineral oil, paraffin and isopropyl myristate. Polymethylphenylsiloxane is a commonly used additive for creams, lotions and sunscreens because it is simple to prepare. It can be used as a masking agent for film masks, hair conditioners and sunscreens. It is widely used as a matrix material for hair and cream cosmetics.

(4) Polycyclic siloxane
Polycyclic siloxane is a colorless, odorless, non-irritating volatile liquid with good gloss, water resistance, softness and dryness, and easy to emulsify (low viscosity). Polycyclic dimethylsiloxane has a suitable volatilization rate, its evaporation rate is lower than that of water and ethanol, and has good dispersibility and volatility; when it volatilizes, the skin has no cold feeling and no residue. The molecular structure of polycyclic dimethyl siloxane is:

(5) Amino modified silicone oil
The amino-modified silicone oil is an organosilicon compound in which a methyl group in polydimethylsiloxane is substituted with an aminoalkyl group, and its structural formula is:
These amino-functional silicone oils are very unique long-chain conditioning agents that improve wetting and lubricity, are compatible with cationic, nonionic emulsifiers, and have poor compatibility with anionic surfactants. They are commonly used in cosmetics for shampoos, conditioners, hair creams, etc., which increase the shine and softness of the hair, comb the hair, improve the hair-fixing effect, and are easy to wash off. Amino silicone oil is used in shampoos to prevent hair damage caused by perming and dyeing.
(6) carboxyl modified silicone oil
The structural formula of the carboxyl modified silicone oil is:
Carboxyl modified silicone oil is a light, transparent, highly viscous liquid with a special odor. It is a nonionic surfactant with extremely low surface tension.
(7) Silicone emulsion
The shampoo system is a non-emulsifying system, and it is difficult to ensure the stability of the product by directly applying the silicone oil to the shampoo formulation. Due to the hydrophobic nature of silicone oils, the difficulty of dispersion in aqueous systems is increased, making their use limited in some respects. The O/W type silicone oil emulsion is prepared by first dispersing and dispersing the silicone oil in the water phase, so that the silicone oil can be conveniently applied to the shampoo.