What is fluorescent pigments and its application?

What is fluorescent pigments and its application?

Fluorescent pigments are divided into inorganic fluorescent pigments (such as fluorescent pigments used in fluorescent lamps and anti-counterfeiting fluorescent inks) and organic fluorescent pigments (also known as daylight fluorescent pigments): only substances with specific chemical structures can have fluorescent properties. However, these fluorescent colorants themselves often have inherent deficiencies in light resistance and solvent resistance. One way to overcome these inherent deficiencies is to fuse them into the framework of polymer materials through chemical or physical methods, and then further process them into pigments. The polymer material used for this purpose not only acts as a solvent for the fluorescent colorant, but also provides protection for the fluorescent colorant, thereby giving the fluorescent colorant better light resistance and solvent resistance.

Fluorescent dyes are compounds with special structures, and their structural features mainly include the following three points:

(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) The molecule contains auxochrome groups. 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 conjugated π bonds with a rigid planar structure. The larger the intramolecular conjugated system, the stronger the planarity, the higher the fluorescence intensity. Some factors that can improve the degree of conjugation can increase the fluorescence efficiency and shift the fluorescence wavelength to the long-wave direction.

Fluorescent pigments have excellent performance in the coloring of plastics, sols, paper products, color pastes, inks, paints, coatings, color masterbatches, chemical fibers, textiles, etc.