Compound efficiency of fluorescent whitening agents, dyes and pigments

In our production and life, different groups of people have different preferences for colors. For example, white, many people do not like pure white, but prefer white with a certain tone. They think that these white with tint is the most ideal white.

Europeans and Americans tend to prefer a purplish-red whiteness because their corneas are slightly green, as if they are wearing tinted glasses. In China, many customers like white with bluish light and believe that white with this color is the whitest among various "whites". Therefore, when using fluorescent whitening agent alone to whiten the whitened substrate, it often cannot meet the requirements. The hue is often not obvious enough. At this time, some dyes or pigments need to be added to adjust to improve the visual effect of this white.

Fluorescent whitening agents will only reflect fluorescent whiteness under blue-violet light, while the effects of dyes and pigments are not affected by ultraviolet light. Therefore, the whitening products compounded with dyes and pigments no matter whether the irradiation light source contains enough The ultraviolet components all give people the feeling that the "whiteness" has been enhanced.

But it should also be noted that although trace amounts of dyes and pigments increase the whiteness of whitened materials, the brightness of the materials is reduced. This is just because the human eye is more sensitive to differences in hue and light than to differences in brightness. This slight loss of brightness is simply accepted by default.

In practical applications, the amount of dye or pigment used to adjust the color is very small, usually calculated in mg/kg. Judging from the color of the dyes and pigments added, they are usually blue and purple in most cases, and sometimes red is also added.