Molecular Formula | C40H44N12O10S2 |
Molar Mass | 916.98 |
Density | 1.598±0.06 g/cm3(Predicted) |
Melting Point | 290°C |
pKa | -1.28±0.50(Predicted) |
Storage Condition | Store at RT. |
Physical and Chemical Properties | Light yellow powder, odorless, soluble in alkanes, fats, mineral oil, paraffin and most organic solvents, the maximum spectral absorption value of 375mm (in ethanol), the maximum emission wavelength of 435nm (in ethanol). |
Use | OB is widely used for whitening PVC, PE, PP, PS, ABS and other thermoplastics, polyester fiber, paint, ink, paint, etc. Mainly used for whitening PVC, PS, PE, PP, ABS and other plastics and acetate fiber, paint, paint, ink, etc. |
Hazard Symbols | Xi - Irritant![]() |
Risk Codes | 36 - Irritating to the eyes |
Safety Description | 26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
WGK Germany | 3 |
Toxicity | 荧光增白剂会极大削弱免疫力及伤口愈合能力,一旦在人体中蓄积过量,除了对肝脏等重要器官造成严重危害之外,还会诱发细胞癌变,是潜在的致癌因素之一,一旦与人体中的蛋白质相结合,就很难通过正常代谢排出体外。一旦与食品直接接触,污染到食品上,会对食用者的健康造成严重危害。 |
Raw Materials | Sodium carbonate Aniline Cyanuric chloride Ethanolamine 4,4'-Diamino-2,2'-stilbenedisulfonic acid |
Downstream Products | Master-batches |
Fluorescent whitening agent, also known as optical whitening agent, referred to as whitening agent, is a fluorescent dye that excites fluorescence under ultraviolet light. It is mainly used in the textile printing and dyeing industry to improve the whiteness of various natural and synthetic fiber fabrics And enhance the gloss. In recent years, the application in papermaking, plastics, leather, soap, synthetic detergents and other daily necessities industry sectors has also grown rapidly. Its characteristic is that it can convert ultraviolet light into blue, blue-purple or red visible light, produce optical whitening effect, and produce fluorescence due to the excitation of the incoming light, so that the dyed substance can obtain a sparkling effect similar to fluorite. The function of fluorescent whitening agent is to significantly improve the whiteness of the paper and make it radiant and pleasing to the eye, which cannot be achieved by any chemical bleaching agent. For this reason, fluorescent whitening agent is widely used in the whitening treatment of high-grade paper.
Fluorescent whitening agents are organic substances that can improve the whiteness of fiber fabrics and paper. The whitening agent can absorb ultraviolet light with a wavelength of 330~360 nm, and the reflected blue-purple light with a wavelength of 400~440 nm, which is exactly the same as the yellow light originally reflected from the bleached fabric that is still yellowing, thus adding up to become white and making the fabric white. After whitening treatment, some ultraviolet light is also converted into visible light and reflected, and the total amount of reflection is increased compared with that without treatment, so the brightness of the treated fabric also increases, making the white fabric whiter and the colored fabric increase the vividness. Fluorescent whitening is different from chemical bleaching, it will not damage the color and strength of the fabric, but for fabrics and paper with dark background color, if they are directly treated with whitening agent without bleaching, they cannot obtain better results.
fluorescent whitening agent is a substance that can absorb ultraviolet rays in sunlight or other light sources and emit blue to purple fluorescence, so that materials can produce whitening and gloss effects. Because it is the use of optical complementary color effect, so that the dark color of the substance after fluorescence whitening, appear white, bright, so it is also called optical whitening agent. In 1929, P.Krais discovered that 6, 7-dihydroxycoumarin can emit fluorescence under ultraviolet light. After the fabric is impregnated in its aqueous solution, it has a whitening effect. The earliest commercially available fluorescent whitening agent was 4,4 & prime produced by Bayer Company of Federal Republic of Germany in 1940;-bisazinylstilbene -2,2 & prime; Derivatives of disulfonic acid. Since then, many fluorescent whitening agents have been developed, thus forming a series of dyes. It can be roughly divided into 3 types: anionic type with water solubility like sulfonic acid group, cationic type with water solubility like quaternary ammonium salt, and nonionic type that is hardly soluble in water. In recent years, the research focus is on benzo-azoles and styrene.
Fluorescent whitening agent is a complex organic compound with many types. These substances have conjugated double bonds, which can absorb ultraviolet light and reflect visible light waves with longer wavelengths. There are five main types of fluorescent brighteners according to their chemical structure.
(1) stilbene type fluorescent whitening agent is one of the largest varieties and quantities of fluorescent whitening agents. It is mainly used in cotton fiber, paper and detergent industries. For example, fluorescent whitening agent DMS (C.I. fluorescent whitening agent 260) has blue fluorescence.
(2) coumarin type: has the basic structure of coumarone, used for whitening wool, silk and nylon fabrics, and also used in the plastic industry, such as fluorescent whitening agent WS (C. I. fluorescent whitening agent 52) has blue violet fluorescence.
(3) pyrazoline type: for wool, nylon and acrylic fiber whitening, such as fluorescent whitening agent WG (C. I. fluorescent whitening agent 54) with green blue fluorescence.
(4) benzoxazole type: used in polyester, nylon and other fiber and plastic industry, such as fluorescent whitening agent DT (C.I. fluorescent whitening agent 135) has red blue fluorescence.
(5) naphthalene dimethylimide type: used for polyester, acrylic, nylon and other fibers, such as fluorescent whitening agent AT (C. I. fluorescent whitening agent 162) with blue fluorescence.
The whitening effect of fluorescent whitening agent is to use the principle of optical color supplement to whiten the yellowing substance, so it is also called optical whitening agent. After being treated with fluorescent whitening agent, the yellowing substance can not only reflect visible light, but also absorb ultraviolet light (wavelength 300 ~ 400nm) other than visible light and convert it into visible light with purple blue (wavelength 400 ~ 500nm) and reflect it. Yellow and blue complement each other, thus offsetting the original yellow of the substance and increasing the intensity of reflected light, making the treated substance white and pleasing to the eye.
(1) Significant effects can be obtained by adding a small amount of whitening agent to the bleached pulp used for paper with high whiteness requirements, or adding a small amount of whitening agent to the bleached pulp before dyeing the colored paper.
(2) The appropriate amount for whitening of a certain paper should be determined through production tests (small tests can be made first) according to the factors and conditions in the production process.
(3) If the whitening agent is added to a certain amount or is no longer whitening, this is the limit of the dosage. If it is used more, it may cause side effects, turn yellow in color and cause waste.
(4) The higher the whiteness of the pulp before the whitening agent is added, the more obvious the whitening effect is. For example, if the whiteness of the same bleaching pulp is less than 5 degrees, the amount of whitening agent will be twice as different.
(5) It is generally believed that if the dosage of whitening agent exceeds 0.12%, the whiteness of pulp will no longer increase significantly, that is, the limit quantity of whitening agent applied in pulp is 0.12 ~ 0.16%.
(6) The whitening agent has no whitening effect on unbleached pulp with whiteness lower than 60% or 65%. This is because the unbleached pulp contains pigment, and the use of whitening agent only plays a role in improving color light. According to the test, if the amount of whitening agent is increased for the unbleached pulp, the phenomenon of turning the pulp red will also occur.
(1) Significant effects can be obtained by adding a small amount of whitening agent to the bleached pulp used for paper with high whiteness requirements, or adding a small amount of whitening agent to the bleached pulp before dyeing the colored paper.
(2) The appropriate amount for whitening of a certain paper should be determined through production tests (small tests can be made first) according to the factors and conditions in the production process.
(3) If the whitening agent is added to a certain amount or is no longer whitening, this is the limit of the dosage. If it is used more, it may cause side effects, turn yellow in color and cause waste.
(4) The higher the whiteness of the pulp before the whitening agent is added, the more obvious the whitening effect is. For example, if the whiteness of the same bleaching pulp is less than 5 degrees, the amount of whitening agent will be twice as different.
(5) It is generally believed that if the dosage of whitening agent exceeds 0.12%, the whiteness of pulp will no longer increase significantly, that is, the limit quantity of whitening agent applied in pulp is 0.12 ~ 0.16%.
(6) The whitening agent has no whitening effect on unbleached pulp with whiteness lower than 60% or 65%. This is because the unbleached pulp contains pigment, and the use of whitening agent only plays a role in improving color light. According to the test, if the amount of whitening agent is increased for the unbleached pulp, the phenomenon of turning the pulp red will also occur.
Toxic fluorescent whitening agents will greatly weaken immunity and wound healing ability. Once they accumulate in the human body, in addition to causing serious harm to important organs such as the liver, they will also induce cell carcinogenesis, which is a potential carcinogenic factor. One, once combined with proteins in the human body, it is difficult to excrete through normal metabolism. Once in direct contact with food, the contamination of food will cause serious harm to the health of consumers.
The safety of fluorescent whitening agent Regarding the safety of fluorescent whitening agent, when expressed in acute LD50, its value is very high, and it belongs to a type of dye with high safety. Regarding chronic carcinogenicity, the results of DAST studies with large production volume show that there is no carcinogenicity and toxicity. In addition, regarding the impact on the environment, it is believed that the washing powder with fluorescent whitening agent is put into the river with a very thin concentration of whitening agent, and most of the activated sludge can be degraded in about 1 month. It will not accumulate in rivers and marine deposits.
Fluorescent whitening agents are used in the following areas:
(1) directly added to the paper material.
(2) Used for surface sizing, I .e. added to the glue solution for surface sizing.
(3) for the coating of processing paper, I .e. added to the coating liquid of processing paper.
The first method is directly added to the paper material to whiten the most widely used.
The use method of fluorescent whitening agent is as follows:
(1) The whitening agent solution should be prepared as it is used and avoided, because it is sensitive to ultraviolet rays. After being irradiated by sunlight, ultraviolet rays in sunlight can destroy its whitening effect.
(2) In use, the whitening agent can be dissolved in warm water at 50~60 ℃, and about 20 parts of water can be used for 1 part of the whitening agent.
(3) After the whitening agent is fully dissolved, dilute it with cold water to a concentration of 0.3~3.0g/L, and then add it to the paper material.
(4) The dyeing characteristics of fluorescent whitening agent are similar to direct dyes. After adding paper material, it can be fixed with fibers in a short time. For this reason, in order to make the whitening agent well mixed with the fiber and good retention, its solution should be slowly added to the paper stock.
⑤ When adding, the appropriate pH value of the paper material should be close to neutral or slightly alkaline (pH 7~8).
⑥ If a liquid whitening agent solution is used, it should be stored in a dark glass bottle or ceramic container, and must not be exposed to sunlight.
No matter what kind of fluorescent whitening agent is only an optical brightening complementary color, and cannot replace chemical bleaching. Therefore, the colored fibers are treated directly with fluorescent whitening agents without bleaching, and the whitening effect cannot be obtained fundamentally. Attention should be paid when using.