The role of the attachment of chemical dyes is to help chemical dyes develop their colors, improve the compatibility of chemical dyes and downstream resins, and protect the performance of chemical dyes. Usually the carrier resin is a strong polar resin, on the one hand, it can help color and increase the fluorescence efficiency; on the other hand, it has good compatibility with chemical dyes.

Structural characteristics of chemical dyes:

1. The molecule contains a fluorescent-emitting group, such as a carbonyl group, a nitrogen-nitrogen double bond, a carbon-nitrogen double bond, etc.

2. Contains auxochrome groups in the molecule. The auxochrome group makes the spectrum red shift and increases the fluorescence efficiency, such as primary amino group, secondary amino group, hydroxyl group, ether bond, amide group and so on.

3. The molecule contains a rigid planar structure of conjugated π bonds. The larger the intramolecular conjugated system, the stronger the planarity, the higher the fluorescence intensity.

Chemical dyes refer to substances that absorb light waves of a certain wavelength and emit light waves of another wavelength greater than that of the absorbed light. Most of them contain benzene ring or heterocyclic ring and have conjugated double bond compound.