4.4-Diaminediphenylamine-2-Sulfonic Acid

Dihydroxybenzophenone-2-sulfonic acid, its main use is quite extensive.
In the field of daily chemical industry, it is often used as a key ingredient in sunscreen. Ultraviolet rays in sunlight are very harmful to human skin. This substance can effectively absorb ultraviolet rays and convert light energy into heat energy through molecular structure changes, so as to resist ultraviolet rays and protect the skin. It is widely used in sunscreen, sunscreen lotions and other products.
In the plastics industry, it can be used as a light stabilizer. Plastic products are prone to aging, discoloration, and mechanical properties decline after long-term light exposure. Dihydroxybenzophenone-2-sulfonic acid can absorb ultraviolet rays, prevent performance deterioration of plastics due to photodegradation, and prolong the service life of plastic products. This substance is often added in the production of plastic products such as polyethylene and polypropylene.
In the coating industry, it is also an important light stabilizer. Coatings are easily powdered and faded when exposed to sunlight. Adding this substance can enhance the weather resistance of coatings and ensure that the coating maintains color and performance for a long time. It is widely used in outdoor architectural coatings, automotive coatings and other fields.
In the textile industry, it can be used for UV-resistant finishing of fabrics. The fabric treated by it can improve the anti-ultraviolet ability, so that when the wearer wears the clothes made of such fabrics, the skin is less damaged by ultraviolet rays, and the added value of textiles is increased.

Dihydroxybenzophenone is an important organic compound with many unique physical properties.
First of all, its properties are mostly white to light yellow crystalline powder under normal conditions, which is conducive to storage and subsequent processing. Its powder is fine and smooth to the touch.
Looking at its solubility, the substance is slightly soluble in water. Water is a common solvent, and dihydroxybenzophenone has low solubility in this solvent. Although it contains hydroxyl groups in its molecular structure, it can form hydrogen bonds with water, but hydrophobic groups such as benzene rings account for a large proportion, resulting in poor overall hydrophilicity. However, it has good solubility in organic solvents, such as ethanol, acetone, ether and other common organic solvents, which can dissolve dihydroxybenzophenone well. This characteristic is used in organic synthesis, coatings, inks and other fields to facilitate its uniform mixing with other organic components to exert its due effect.
As for its melting point, dihydroxybenzophenone usually has a specific melting point range, which is between 137 ° C and 141 ° C. The melting point is an important physical constant of a substance, and this melting point range indicates that it will change from solid to liquid in this temperature range. The determination of the melting point, its purification, identification and temperature control in a specific process to ensure the stability of its morphology and properties are of great significance.
In addition, dihydroxybenzophenone has a certain thermal stability. In the moderate temperature range, its chemical structure and properties can be maintained stable, and it is not easy to decompose rapidly or undergo chemical changes due to temperature fluctuations. However, when the temperature is too high, it may also trigger reactions such as decomposition, which affect its performance and application effect. This thermal stability property makes it applicable in some production processes or application scenarios that require certain temperature conditions.

Amino-diphenylsulfone-2-sulfonic acid is an organic compound, which has the following chemical properties:
First, acidic. This substance contains a sulfonic acid group (-SO-H), which is easily dissociated by hydrogen atoms, making the compound acidic. In aqueous solution, the sulfonic acid group can partially ionize hydrogen ions (H-H), showing the generality of acids and can neutralize with bases. If it reacts with sodium hydroxide (NaOH), the hydrogen ion in the sulfonic acid group combines with the hydroxide ion (OH) to form water, and the corresponding sulfonate and water are formed. The reaction equation is: R-SO-H + NaOH → R-SO-Na + H 2O O (R represents amino dioxide diphenylsulfone-2-sulfonic acid to remove the rest of the sulfonic acid group).
Second, nucleophilic substitution reaction. In its molecular structure, some positions on the benzene ring are affected by the electronic effects of groups such as amino groups and sulfonic acid groups, and have a certain nucleophilic substitution activity. If it encounters a nucleophilic reagent, the nucleophilic reagent will attack the carbon atom on the benzene ring with a relatively low electron cloud density, and then a nucleophilic substitution reaction occurs For example, when a suitable nucleophilic reagent is available, the halogen atom on the benzene ring (if present) can be replaced by a nucleophilic reagent.
Third, redox properties. Amino groups (-NH2O) have certain reductivity. When encountering strong oxidants, the amino group is easily oxidized, and the nitrogen atom in the amino group increases its valence, resulting in oxidation products such as nitro (-NO ³). Sulfonic acids are relatively stable and difficult to be oxidized under normal oxidation conditions, but when encountering extremely strong oxidants, the sulfur atom's valence may also change, resulting in oxidation reactions.
Fourth, coordination properties. The nitrogen atom in the amino group contains lone pairs of electrons, which can form coordination bonds with certain metal ions as ligands to form complexes. This coordination ability makes amino diphenylsulfone dioxide-2-sulfonic acid play a role in some metal catalytic reactions or metal ion separation and detection.

The production method of dihydroxybenzophenone-2-sulfonic acid is an important matter related to chemical technology. According to the legacy of "Tiangong Kaiwu", it is stated in ancient Ya Chinese as follows:
To obtain dihydroxybenzophenone-2-sulfonic acid, it is first necessary to clarify its raw materials and steps. Often specific organic compounds are used as starting materials and are formed through a series of delicate chemical reactions.
Initially, select the appropriate benzophenone derivative, which is the base. Place it in a suitable reaction vessel, which must be clean and suitable for the reaction conditions. Then, introduce an appropriate amount of sulfonating agent, which is the key to promoting the introduction of sulfonic acid groups. The amount of sulfonating reagent and the temperature and duration of the reaction need to be carefully controlled.
When reacting, the temperature should be stable, or fine-tuned in a specific range. If the temperature is too high, it may cause side reactions to occur, and the product is impure; if the temperature is too low, the reaction will be slow and take a long time. The time also needs to be accurately measured. If it is too short, the reaction will not be completed, and if it is too long, there may be a risk of overreaction.
During the reaction process, it is necessary to pay close attention to the changes in the reaction system and observe the changes in its color and state. When the reaction is approaching the expected degree, the product will be precipitated by an appropriate method of separation and purification. By means of filtration, crystallization, distillation and other means, impurities can be removed to obtain pure dihydroxybenzophenone-2-sulfonic acid.
Although this production method is simple, each link requires fine operation, and a slight error will affect the quality and quantity of the product. It is the exquisite technology of chemical industry, which requires careful study and repeated practice by practitioners to obtain its essentials and produce high-quality products.

Dihydroxybenzophenone is a commonly used sunscreen, and there are many things to pay attention to during use.
One is related to safety. Although this substance has been widely studied and approved by regulatory authorities for use in cosmetics, some individuals may have allergic reactions to it. Therefore, when users apply products containing this ingredient for the first time, they should try it on a small area of skin, such as behind the ear or inside the wrist, to observe whether there is redness, swelling, itching, tingling and other discomfort, and to ensure that there is no allergy before using it in a large area.
The second is about light stability. Although dihydroxybenzophenone has the ability to absorb ultraviolet rays, it may undergo structural changes under light, which will reduce the protective effect and even generate potentially harmful products. Therefore, sunscreen products containing this ingredient should be properly stored, stored in a cool place away from light, and should also be reapplied in a timely manner when using to maintain the sunscreen effect.
Third, it involves its interaction with other ingredients. In cosmetic formulations, dihydroxybenzophenone may interact with other additives and active ingredients. For example, it may chemically react with certain preservatives and fragrances to change the stability, texture or efficacy of the product. Therefore, when consumers choose products, they should pay attention to the ingredient list. If they are in doubt about the combination of ingredients, they can consult a professional.
Fourth, from the perspective of environmental impact. Dihydroxybenzophenone is discharged into the environment after use or with domestic wastewater, which may be potentially harmful to aquatic organisms and other ecosystems. Therefore, users should enhance environmental awareness and try to choose environmentally friendly sunscreen products. If using those containing this ingredient, avoid applying a large amount of it in the near water area to prevent excessive pressure on the water ecology.