Hair coloring has become a fashion choice for people. According to CCTV International Network Survey, more than 90% of the more than 2,600 people surveyed have dyed their hair, and about half of them started dyeing their hair before the age of 30. Hair dye processing manufacturer Guangzhou Youji Daily Chemical Co., Ltd. today will give you three types of science popularization: hair dyes can be divided into three types according to the length of action: temporary hair dyes, semi-permanent hair dyes, permanent hair dyes Agent 1. Temporary hair dye Temporary hair dye is a hair dye that can remove the color on the hair with just one wash with shampoo.
Because the particles of these hair dyes are very large, they cannot enter the hair through the cuticle to dry, but can only be deposited on the surface of the hair to form a colored layer. In this way, the interaction between the dye and the hair is not strong and can be easily washed away by shampoo. 2. Semi-permanent hair dyes Semi-permanent hair dyes usually mean that they only fade after 6-12 shampoos.
Semi-permanent hair dyes are applied to the hair, left for 20-30 minutes, and then rinsed with water to change the color of the hair. The principle of action is that the relatively small molecular weight dye molecules penetrate the hair cuticle, partly into the cortex, making it more resistant to shampooing than temporary hair dyes. Since it does not require hydrogen peroxide and does not damage the hair, it has become more popular in recent years.
3. Permanent hair dye There are three types of permanent hair dye: plant permanent hair dye, metal permanent, and permanent oxidation. 3.1 Plant Permanent The substance extracted from the stems and leaves of plants is used for dyeing, which is expensive and rarely used in China. 3.2. Metal is permanently dyed with metal materials, the dyeing is mainly deposited on the dry surface of the hair, and the color has a darker metallic appearance, which makes the hair brittle and the perm efficiency is low.
3.3. Mainstream products in the oxidation permanent market do not contain dyes, but contain dye intermediates and coupling agents. After these dye intermediates and coupling agents penetrate into the hair cortex, oxidation reactions will occur. Coupling and shrinkage reactions form a larger dye molecule, which is enclosed in the hair fiber. Due to the different types of dye intermediates and couplers, the reaction products with different hues will be produced due to the different content and ratio.
Various shade products are combined into different shades to dye hair in different colors. Because the dye macromolecule is produced by the reaction of the dye intermediate and the small molecule of the coupling agent in the hair fiber. Therefore, during the cleaning process, the dye macromolecules are not easy to clean through the pores of the wool fiber.