Acid dyes refer to the acid group in the dye molecules, also known as anion dye, which can be combined with amino groups in protein fiber molecules. Acid dyes are water -soluble dyes with acid groups on a type of structure. The initial stage of development is mainly dyed under acidic conditions, so it is used to call it acid dye.
The combination of electro -electrostatic gravitation in the process of acid dyes plays an important role in the upper dyeing process. The dye structure is relatively simple. The dye molecules lack a long -term double -key system.
Acid dyes are suitable for acidic, weak acid or neutral conditions. Mainly nitrogen and ， structures, a few are aromatum methane structures. Dyes generally have color and can make other substances clear and firm color in molecular or decentralized state.
Acid dyes are often used for dyeing of wool, silk and nylon products
Conditions of wool dyeing on acid dyes:
Wool has a scale layer structure, which is resistant to strong acid, and can be dyed under strong acid conditions.
Conditions of silk dyeing on acid dyes:
Silk is not resistant to strong acid, and can only be stained under weak acid or neutral conditions.
Conditions of sirming on acid dyes:
Nylon is a synthetic polyamide fiber; nylon fiber macromolecules are mainly composed of three parts, namely hydrophobicyls, amin and carboxyls with hydrophilicamine and chain; nylon dyeing Perform with neutral conditions.
The structure, physical and chemical performance of the fiber, and the possible combination of dyes determine that the dyes used in their dyes need to meet certain conditions.
As far as the three fibers of wool, silk, and nylon are concerned, the dyes used must meet the following requirements:
1. Contains anionic groups such as sulfonic acid groups, which gives dyes water -soluble, and combine with amino groups with ionization on the fiber;
2. Contains hydrophobic groups that can form a non -polar Van Dehua force with fiber;
3. Contains groups that contain amino, hydroxyl or amide, etc. that can form hydrogen bonds with fibers;
4. There is a good acid resistance, and the amino groups in dyes are often germinated.