Optical Brightener Agent: Are They Dyes Or Auxiliaries?

What is Optical Brightener Agent?

British physicist George Gabriel Stokes first described the phenomenon of fluorescence in 1852. In 1929, Krais.P first discovered that 6,7-dihydroxycoumarin had a fluorescent whitening effect; in 1940, the German IG company developed a fluorescent whitening agent with practical value and began its commercialization process.

In 1959, the original Tianjin dye factory produced China's first Optical Brightener agent, V B L (C.I.85), which is a bistriazine aminostilbene type. In 1966, the former Ministry of Chemical Industry promulgated the chemical industry standard for this variety (Ministry-issued Standard), numbered HG 2-382-66, which is the first industry standard for optical brightener products in China. The product standard has now been upgraded to GB / T 10661-2003 "Fluorescent Whitening Agent VBL". Fluorescent brighteners were originally only used in the textile printing and dyeing industry in China. In the late 1960s, optical brightener agents began to be used in the synthetic detergent industry, and only used in the paper industry in the 1970s.

Optical Brightener Agent are used in a wide range of applications, from textiles to detergents, plastics, coatings, inks, and leather. With the rapid economic development, the uses and dosages of fluorescent whitening agents are still expanding. At present, the textile industry is not the field with the largest amount of Optical brightener agent. In different countries in the world, there are differences in the proportion of Optical brightener agent in different industries, but the order of the proportion of use is basically the same: that is, it is mainly used in detergents, followed by papermaking, textiles, and plastics and other areas in smaller amounts.

Application in Textile Field

optical brightener agent have been used in the textile industry for nearly 70 years. They are favored by dyeing and finishing industry and consumers because of their unique whitening and brightening effects on textile fibers. At present, there is no corresponding technology that can replace the role of optical brightener agent agents.

Some people think that bleaching can replace optical brightener agent agents. And some products in this area have been researched, such as chlorine bleaching and oxygen bleaching to achieve the whiteness of the fabric.

There are requirements for the application of optical brightener agent on textiles, which should meet at least the following 5 requirements:

①No damage to the fiber, and it has good knot and force;

② has better water solubility;

③ Has good chemical stability;

④ Has better uniform whitening;

⑤ Harmless to the environment.

According to the type of chemical structure, the optical brightener agent used in the textile industry mainly include six categories:

① Ditriazine amino stilbene type;

② stilbene biphenyl type;

③ bisbenzoxazole type;

④ stilbene benzene type;

⑤ Pyrazoline type;

⑥ Coumarin type.

When using a optical brightener agent agent, a suitable optical brightener agent agent must be selected according to the chemical composition and physical properties of the fiber, so as to obtain a satisfactory whitening effect.

Internationally, optical brightener agents are considered to be a white dye, and each structured optical brightener agent has its corresponding dye index number; in China, optical brightener agents are generally considered to be an important functionality Finishing aid.

optical brightener agent are used as dyes, and their safety should meet the safety standards for dyes. China has promulgated two standards:

GB 19601-2013 "Limits and determination of 23 harmful aromatic amines in dye products"

GB 20814-2014 "Limits and determination of 10 heavy metal elements in dye products"

Analysis of 23 harmful aromatic amines in dye products by gas chromatography / mass spectrometry and other analytical methods provides a reliable basis for the detection of harmful aromatic amine compounds in dye products, and further limits the content of harmful aromatic amines in dye products (≤ 150mg / kg); the determination of heavy metals in dye products by atomic absorption spectrometry provides a reliable basis for the detection of heavy metals in dye products, thereby limiting the content of heavy metals in dye products.

optical brightener agent are used as auxiliaries, and their safety should meet the safety standards of auxiliaries. In 2006, the General Administration of Quality Supervision, Inspection and Quarantine and the National Standardization Administration of the People's Republic of China promulgated GB / T 20708-2006 "Limits and Determination of Some Harmful Substances in Textile Auxiliary Products". Aromatic amines (≤30mg / kg, stricter than dye standards), limits of heavy metals and formaldehyde, test methods, inspection rules, test reports.

The application of optical brightener agent agents in the textile industry and the safety of textiles that have undergone various processing in the market are also guaranteed by mandatory safety technical specifications. China's current GB 18401-2010 "National Basic Safety Technical Specifications for Textile Products", the standard specifies the basic safety technical requirements, test methods, inspection rules and implementation of infant and toddler products, products directly in contact with skin, and products not in direct contact with skin. Supervision, including requirements for banning decomposable aromatic amine dyes, formaldehyde limits, pH, etc.

Therefore, regardless of whether the optical brightener agent agent is used as a dye or as an auxiliary, as long as the enterprise producing the optical brightener agent agent can produce, sell, and use a optical brightener agent agent that meets the standards, the use of optical brightener agent products on textiles will be Consumers are safe. It is not difficult to understand that it is also safe to add optical brightener agent agent to detergents to wash clothes and other fabrics.

However, with the development of China's economy and the improvement of living standards, the demand for optical brightener agents will also keep pace with the day, and the development of optical brightener agent agents will also be rapid. It is necessary to continuously follow up the development of technology and the revision of standards, strengthen the safety research of new varieties, and regulate the market. Regardless of the industry in which the optical brightener agent agent is applied, there must be corresponding research on safety and standards for use, so that the personal health of our consumers can be guaranteed, and various areas of the national economy can develop in a healthy and orderly manner.