C.I. Direct Black 9Disodium 8-Amino-5-[(E)-{4-[(2Z)-2-{7-[(E)-(2,4-Diaminophenyl)Diazenyl]-1-Oxo-3-Sulfonatonaphthalen-2(1H)-Ylidene}Hydrazinyl]Phenyl}Diazenyl]Naphthalene-2-Sulfonate

C.I. Direct Black 9 is widely used in the field of printing and dyeing. It is one of the direct dyes, often applied to cellulose fiber fabrics, such as cotton and linen. Cotton fabrics, if you want to get a deep black color, rely on this dye. It can be used in neutral or weakly alkaline dyeing baths to dye fibers directly, and it is easy to operate, and everyone is happy to use it.
In the paper industry, C.I. Direct Black 9 also has its uses. When making paper, if you want to give paper a black luster, this dye can play its role. It can add a solemn color to the paper, and dye it with paper products such as wrapping paper and writing paper to make the paper pure and dark.
The industry of leather dyeing, see also the figure of C.I. Direct Black 9. Leather wants to be black and bright, this dye can help it. After its dyeing, leather has a uniform color and a certain degree of firmness, which can increase the beauty and quality of leather.
The genus of fabric printing, C.I. Direct Black 9 is also commonly used. It can print clear black lines on the fabric, making it an important color for printing patterns. The printed pattern is black and eye-catching, adding a bit of charm to the fabric.
In summary, C.I. Direct Black 9 is used in many fields such as printing and dyeing, papermaking, leather, fabric printing, etc. It is used for its convenient dyeing, deep color and other advantages, and occupies a place in industrial dyeing.

C.I. Direct Black 9 is a commonly used direct dye with many unique chemical properties.
This dye has good solubility and can be easily dispersed and dissolved in water, which is conducive to uniform penetration into the fiber during the dyeing process, making the dyeing more uniform. And it has a good affinity for cellulose fibers such as cotton and hemp, and can be tightly combined with it, so that the dyed fabric has good color fastness and is not easy to fade during daily wear and washing.
Furthermore, the chemical stability of C.I. Direct Black 9 is quite considerable. Under normal dyeing conditions, it is not easily affected by factors such as temperature and pH, which can ensure stable dyeing quality. However, it also has some limitations, such as the light resistance is sometimes slightly insufficient, and the color of dyed fabrics may become slightly lighter after long-term light exposure. In addition, in some special environments, its washing fastness may also need to be further improved by specific post-treatment processes. Overall, C.I. Direct Black 9 is widely used in the field of cellulose fiber dyeing due to its outstanding solubility and affinity. However, its light resistance and other characteristics need to be specially considered and dealt with in some occasions where color fastness requirements are strict.

C.I. Direct Black 9 is also one of the chemical pigments. In terms of its safety, it should be viewed from multiple aspects.
First, its chemical structure and composition, this pigment contains specific chemical groups and substances. However, there may be potentially harmful components. Past studies have shown that some pigments containing similar structures may be toxic.
On the side of human health, if people are exposed to it for a long time, through skin absorption, respiratory ingestion or accidental ingestion, or adverse effects. Or irritate the skin, causing itching, redness and swelling; if it enters the respiratory tract, or damages the respiratory system, causing cough, asthma and other diseases. As for ingestion, it may harm the digestive system, and there is a risk of abdominal pain and vomiting.
And look at its impact on the environment. If this substance flows into the nature, in terms of water ecology, it may cause water pollution and harm aquatic organisms. In the soil, or change the chemical properties of the soil, hindering plant growth. And it may be difficult to degrade in the environment, and it will persist for a long time, accumulating and causing harm.
Although there may be regulations to control its use at present, when people use it, they still need to be cautious and carefully observe its scope of application and protection methods to prevent it from endangering health and the environment.

C.I. Direct Black 9 is one of the direct dyes. Compared with other similar dyes, it has its own extraordinary advantages.
It is easy to operate when dyeing and finishing fabrics. No complicated steps are required, and only a simple process can make the fabric colored. Like the ancient dyers, it can be colored on cloth with a simple method. This dye is just like the convenience of that time, saving the dye shop a lot of trouble. No special additives are required to help when dyeing. Under normal conditions, it can be affectionate with fabrics, just like old friends meeting, natural harmony.
Furthermore, the color fastness of this dye is quite commendable. The fabric dyed by it is not easy to fade when it is illuminated and washed with water. Just like the ancient Danqing, after years, the color can still be retained, unlike the mundane color, which loses its brilliance after a little wind and rain. In daily wear and use, it can keep the color bright for a long time, making the fabric last for a long time.
C.I. Direct Black 9's even dyeing is also excellent. The dye is evenly distributed on the fabric, and there is no danger of different shades. Just like a skilled craftsman's painting, the pen is delicate, and the color is natural. The dyed fabric has the same overall tone and no mottled state. It is pleasing to the eye and shows the excellent quality.
And the dye has a wide range of applications. Whether it is cotton and linen of natural fibers or polyester of chemical fibers, it can be adapted to it. Just like a good doctor, it can treat a variety of diseases, not limited to one. In this way, in the field of textile printing and dyeing, it is widely used and gives unique colors to many fabrics, which is indispensable.

C.I. Direct Black 9 is one of the dyes, and its production process is exquisite and complicated, involving many processes.
At the beginning, the raw materials need to be carefully prepared. Select the appropriate aromatic amine compounds, such as p-nitroaniline, as the cornerstone of the construction of dye molecules. This raw material needs to be strictly screened to ensure that the quality is pure and flawless, so as to pave the way for subsequent reactions.
Then, the diazotization reaction is carried out. The selected aromatic amine compounds are cleverly reacted with sodium nitrite in a low temperature and strong acid environment. This process is like a microscopic chemical dance. Sodium nitrite is turned into a smart dancer, accurately embedded in aromatic amine molecules, and successfully generates diazonium salts. This step is very strict in controlling the reaction conditions. A slight deviation in temperature and a slight imbalance in pH can cause the reaction to be disordered, and the amount of diazonium salt generated is insufficient or the quality is poor.
Then, the coupling reaction is carried out. The diazonium salt and specific coupling components, such as naphthalene phenols, blend with each other under suitable pH and temperature conditions. The two are like tenon and tenon joints that fit closely, and gradually build the basic structure of the dye molecule. The key to this reaction lies in the delicate balance between pH and temperature. A little carelessness can easily cause the coupling check point deviation, and the color and performance of the dye are affected.
When the molecular structure is initially formed, it needs to go through a series of post-processing processes. Including refining and purification, by means of filtration, washing, crystallization, etc., to remove impurities and improve the purity of the dye. After drying treatment, excess moisture is removed to make the dye appear in a stable solid state. Finally, after grinding and other operations, the particle size of the dye is adjusted to optimize its dispersion performance, making it more suitable for practical applications.
Such a set of carefully carved production processes can produce high-quality C.I. direct black 9 dyes, which shine in the fields of textile printing and dyeing.