Views: 2 Author: Site Editor Publish Time: 2023-09-05 Origin: Site
Fluorescent whitening agent is a fluorescent dye, or white dye, and is also a complex organic compound. Its characteristics are to stimulate the radiation of the incident light to generate fluorescence, so that the infected matter can obtain the glittering effect of fluorite -like fluorite, making the substances seen by the naked eye very white.
Classification of fluorescent whitening agent
It can be divided into five categories by chemical structure:
1. The two -styrene type, for cotton fiber and certain synthetic fibers, papermaking, soap and other industries, with blue fluorescence;
2. Clycein type, has the basic structure of fragrance ketone, is used for cyanus, polyvinyl chloride plastic, etc., with strong blue fluorescence;
3. Pattlerin type, used for fiber such as wool, polyamide, acrylic, has green fluorescence;
4. Benzene oxygen nitrogen type is used for fibrous fiber and plastic plastic such as polyvinyl chloride, polystyrene, and red fluorescence;
5. Benzylide is used for polyester, acrylic, nylon and other fiber, with blue fluorescence.
2. Principles of fluorescent whitening agent
A fluorescent whitening agent is a color conditioning agent, which has a bright and white effect, and is widely used in many fields such as papermaking, textiles, and washing agents. There are about 15 basic structures of fluorescent whitening agents and nearly 400 structures. There are two types of fluorescent whitening agents that are allowed to be added to the detergent of clothing: di -styrene -based pedibin (such as CBS, etc.) and biprathide (such as 33#, etc.).
The principle of fluorescent whitening agent is to absorb ultraviolet light that is not visible in the light, and emit visible blue light. After superimposed with the yellow light from the fabric, it complements the white light to increase the white light emitted by the fabric. Bright white, this is the bright white effect. The fluorescent whitening agent can absorb the invisible ultraviolet light. The wavelength of the original incident was more visible in the range of 400-600 nm, which made the product look white, brighter and more bright.
3. Application of fluorescent whitening agent
For the first time, humans explained that the fluorescence phenomenon was in 1852, when Stokes proposed the theory of being called stokes law by later generations. In 1921, Lagorio observed that the visible fluorescent energy from fluorescent dyes was lower than the visible light energy it absorbed. To this end, he inferenceed that fluorescent dyes have the ability to convert invisible ultraviolet light to visible fluorescence. He also found that the whiteness of natural fibers can be improved by the aquatic solution of fluorescent substances. In 1929, Krais used the principle of Lagorio to prove that the yellowed artificial silk was immersed in the solution of 6,7-dihydroxylcorcosacrais. After drying, it was found that the whiteness of the artificial silk had significantly improved.
The rapid development of fluorescent whitening agents has enabled people to list this with the advent of active dyes and organic pigment DPP as the three major achievements of the dye industry in the late 20th century.
Many industries have begun to use fluorescent whitening agents, such as paper, plastic, leather, detergent. At the same time, fluorescent whitening agents are also used in many high -tech fields, such as: fluorescent detection, dye laser, anti -counterfeiting printing, etc., and even high -altitude photography for high -altitude photography to improve the sensitivity of sensor, and also use fluorescences. Black agent.
In China, fluorescent whitening agents were first divided into print -dyeing additive products, and then divided into dye products. Due to its unique nature and a large amount of dosage, it has been separated from the above two industries and has become a separate type of fine chemical products. The largest user of domestic fluorescent whitening agents is detergent, the second largest user is paper, and textiles are the third largest users.