What Are Sulfur and Salicylic Acid Used to Treat?

Salicylic acid is a fat-soluble organic acid. It is a white crystalline powder. It exists in natural willow bark, white bead leaves, and sweet birch trees. It is an important fine chemical raw material and can be used in the preparation of aspirin and other drugs.

(1) Physical properties

Appearance and properties: white needle-like crystal or hair-like crystalline powder.

1. Alkali and iodometric titration standards.

1. Phenol reacts with sodium hydroxide to produce sodium phenolate. After dehydration by distillation, carboxylation reaction is carried out through carbon dioxide to obtain sodium salicylate, which is then acidified with sulfuric acid to obtain a crude product. The crude product is refined by sublimation to obtain the finished product. Raw material consumption quota: phenol (98%) 704kg / t, caustic soda (95%) 417kg / t, sulfuric acid (95%) 500kg / t, carbon dioxide (99%) 467kg / t.

2. The preparation method is obtained by carboxylation of sodium phenol salt and carbon dioxide and then acidification. Phenol and liquid caustic soda are used to make a phenol sodium salt solution, vacuum dried, and then dry carbon dioxide is slowly passed in at 100 ° C. When the pressure reaches 0.7 to 0.8 MPa, the carbon dioxide is stopped and the temperature is raised to 140 to 180 ° C. After the reaction is completed, water is added to dissolve the salicylic acid sodium salt, and then decolorized and filtered, and then acidified with sulfuric acid to precipitate salicylic acid. After filtering,

(1) Dangerous overview

Health hazard: the dust of this product

Dermatologists can perform fruit acid peels with a concentration of more than 50%. Salicylic acid peels are classified as medical treatments regardless of the concentration. It is worth noting that a few people are not suitable to use any concentration of water. Salicylic acid, so beauty salons ca nt perform it. It is legally permissible for skin peels with a concentration of less than 40% to be used in beauty salons. By comparison, fruit acid is much safer than salicylic acid. As for the effect, salicylic acid only locks in the superficial stratum corneum, only for the purpose of simple treatment and blocking, and the change of skin texture is only temporary, while the fruit acid enters the dermis layer to fundamentally change the skin texture, which can be cured. As for the acne pits formed by damaged dermis, the effect of salicylic acid seems to be powerless, so salicylic acid cannot be called "salicylic acid peeling", it can only be called "salicylic acid treatment". The safety and effectiveness of salicylic acid peels are different from those of fruit acid peels, because fruit acids are non-toxic and can be used from low to high (8% -15% -20% -30% -40% ). Salicylic acid is toxic. Excessive concentrations are not suitable for use on the face. There is a certain concentration limit. Salicylic acid at a concentration of 3% -6% can be used to exfoliate, higher than 6%. It is corrosive to the skin. 40% high concentration of salicylic acid has strong keratinous corrosive properties.