Background and overview[1][2]
Due to the destruction of the ozone layer, the intensity of ultraviolet radiation radiated to the ground continues to increase, resulting in a sharp increase in the incidence of human skin cancer. Therefore, ultraviolet protection technology is attracting increasing attention. Increasing the UV resistance of textiles is an effective way to reduce UV damage to skin. Although the textile itself has a certain effect in blocking ultraviolet rays, it varies greatly depending on the type of fiber and the structure of the fabric. Research shows that among various fibers, cotton has the lowest UV absorption performance. The thinner the fabric and the greater the void content, the easier it is for UV rays to pass through. In the summer when ultraviolet radiation is the strongest, people often choose light and thin fabrics that cannot effectively resist the invasion of ultraviolet rays, especially cotton fabrics, for which anti-ultraviolet finishing is particularly important. Ultraviolet absorber UV-9 is a benzophenone organic compound that can effectively absorb ultraviolet light of 280 ~ nm that is most harmful to the human body. It is widely used in paints, plastics and other polymer materials.
Apply[3]
UV absorber UV-9 is used in plastics, chemical fibers, paints and petroleum products. It is especially suitable for light-colored transparent products. It can be used in paints and various plastic products. It is suitable for polyvinyl chloride, polyester, acrylic, resin, Polystyrene and light-colored transparent furniture are particularly effective, and they are also good cosmetic additives. Benzophenone ultraviolet absorbers are excellent stabilizers for synthetic plastics such as polyethylene. The dosage is 0.5 to 1.5%. They can also be used in paints, pigments, coating industries, refined wax and daily cosmetics. It is a broad-spectrum ultraviolet absorber with high absorption rate, non-toxic, non-teratogenic effect, good light and thermal stability, etc. It can absorb both UV-A and UV-B. It is a Class I approved by the US FDA. Sunscreen-like agents are frequently used in the United States and Europe and are widely used in sunscreen cosmetics such as sunscreen ointments, creams, honeys, lotions, and oils. They can also be used as anti-discoloration agents for products that change color due to photosensitivity.
PreparationAlcohols[1,2,4]
Method 1: Ultraviolet absorber UV-9 Synthetic route: Resorcinol and dimethyl sulfate undergo methylation reaction to generate resorcinol dimethyl ether, which is then reacted with benzoyl chloride under the catalysis of aluminum trichloride Carry out Freund-Greek reaction, and the reaction product is hydrolyzed to obtain the product:
Specific steps: Dissolve resorcinol in NaOH solution, add excess dimethyl sulfate dropwise at 26 to 30°C while stirring, and keep the reaction for 4 hours. After the reaction is completed, add hydrochloric acid to neutralize, let it stand, and separate the aqueous layer. The oil layer is washed and then distilled under reduced pressure to remove water and excess dimethyl sulfate (recovery) to obtain resorcinol dimethyl ether. Add AlCl3 to resorcinol dimethyl ether at 0 ℃, stir and dissolve, add chlorobenzene, and drip in benzoyl chloride while stirring, keeping the temperature at 0 ℃ em>left and right. After the reaction is completed, add an appropriate amount of water to carry out the hydrolysis reaction. The hydrolyzed product is distilled under reduced pressure to evaporate chlorobenzene and remaining benzoyl chloride (recovered). The remaining liquid is cooled to 60～70℃��Add ethanol and activated carbon for decolorization and crystallization to obtain the product UV absorber UV-9.
Method 2: A synthesis method of ultraviolet absorber UV-9, including a condensation step and a methylation step. The innovation is that the condensation step is to first prepare raw materials and reagents, and the molar ratio of raw materials to reagents It is: Resorcinol: Trichlorotoluene: Catalyst: Solvent = 1:1～1.2:0.1～0.3:5～10, first add the solvent and resorcinol according to the proportion, heat it up until it is completely dissolved, and then add the catalyst. Then add trichlorotoluene dropwise, and control the temperature to maintain 45 to 55°C during the dropwise addition. After the dropwise addition, the reaction is carried out, and the reaction temperature is controlled to be 55 to 70°C. The time is 5.5 to 6.5 hours. After the reaction is completed, the temperature is raised to 70 to 75°C and kept for 1 to 1.5 hours to obtain 2,4-dihydroxybenzophenone. The methanone solution is cooled to below 20℃ and then filtered. Finally, wash the filtrate with hot water of 50～60℃ until neutral, 80～85℃ em>Drying, the drying time is 6~6.5h.
Further, the methylation step involves first preparing materials and reagents. The molar ratio of materials and reagents is 2,4-dihydroxybenzophenone:methide:sodium hydroxide:water=1: 1 Anti-aging agent rd.2～1.5:1～1.3:25～30, first dissolve sodium hydroxide in water, cool to 5～8℃ and then add 2,4-dihydroxydiphenyl Ketone, cool down to below 0℃, add methylate dropwise for reaction, control the reaction temperature to be 0～2℃, the reaction time is 6～6.5h, after the reaction is completed Remove the solvent under vacuum, then distill under reduced pressure to collect the 160°C/5mmHg fraction, and finally filter or recrystallize to obtain the product.
Method 3: A production method of ultraviolet absorber ultraviolet absorber UV-9 (BP-3). The production process mainly includes: crude BP-3: crude BP-1 and dimethyl sulfate are reacted with dimethyl sulfate in n-hexane solution using sodium carbonate as the neutralizing agent to generate BP-3; crude BP-3 is produced by heating and distillation; BP-3 refining: BP-3 crude product is heated, cooled, crystallized and filtered in methanol solution to obtain BP-3 refined product, which is dried to obtain the finished product with product content ≥99.9%. The production method of ultraviolet absorber UV-9 (BP-3) provided by the invention reduces solvent residues, there is no longer toluene residue in the product, and the safety of the product is improved. Furthermore, the production process is reduced, which reduces the production cost.
Method 4: The synthesis reaction is carried out in two steps. The first step involves a methylation reaction between resorcinol and dimethyl sulfate to generate resorcinol dimethyl ether. The second step of the reaction is a Friedel-Crafts reaction between resorcinol dimethyl ether and benzoyl chloride in the presence of anhydrous aluminum trichloride catalyst. The reactants are hydrolyzed, crystallized, and dried to obtain the final product. 2-Hydroxy-4-methoxy-benzophenone. Use dichloroethane as the solvent, hydrochloric acid hydrolysis, activated clay decolorization, and finally recrystallization with methanol to obtain the product. The process flow chart is as shown in the attached figure:
The specific steps are as follows:
Step 1: Synthesis of resorcinol dimethyl ether. Put 110g of resorcinol and 298g of dimethyl sulfate into a 2000ml four-necked flask. Under stirring, add a certain amount of 40% sodium hydroxide dropwise. After the dropwise addition is completed, keep at 40 ~ 45 ℃React for 1 hour, stand for separation, and obtain 131.1g of product after distillation, with a purity of 98% and a yield of 95%.
Step 2: Synthesis of 2-hydroxy-4-methoxy-benzophenone. Add 80g of resorcinol dimethyl ether, aluminum trichloride and dichloroethane into a 2000ml four-necked flask. At a certain temperature, add 85.6g of benzoyl chloride dropwise while stirring. After the addition is completed, heat up and react for several hours. Then add hydrochloric acid solution for hydrolysis, then wash with water, and after standing for separation, add 4.8g of activated clay for reflux and decolorization for 0.5h, filter and distill, and then add a certain amount of methanol to recrystallize to obtain a light yellow needle-shaped solid, with an average yield of 78.10 %.
Main reference materials
[1] Synthesis and application of ultraviolet absorber UV-9
[2] Improvement of the synthesis process of ultraviolet absorber UV-9
[3] CN201410215535.0 A synthesis method of ultraviolet absorber UV-9
[4] CN200810048661.6 Ultraviolet absorber UV-9 production method
