What are the Common UV Absorbers?

Ingredients: phenyl o-hydroxybenzoate

Colorless, crystalline powder. It has an aromatic scent (wintergreen smell). Density: 1.250g/cm3, Melting point 43, Boiling point (1.6kPa), 173. It is soluble in chloroform, benzene, ether and ethanol. Water and glycerin are almost insoluble.

The product is used as a UV-absorbing material in plastics, but its wavelength range of absorption is limited. Acrylic resin products have been approved by the US Food and Drug Administration for food contact.

Ingredients: Reaction product of onitroaniline with p-cresol

Performance and Use: The appearance of the crystals is light yellow or colorless. It can dissolve in organic solvents like gasoline, benzene and acetone. It is extremely insoluble in water, and it does not decompose when exposed to concentrated acid or alkali. Salts can be formed by combining it with heavy metal ions. It absorbs ultraviolet rays of wavelength 270-280nm. Melting point 130~131.

This product is used primarily in polyvinylchloride, polyvinylstyrene (PVC), polyvinyl chloride (PVC), polyacrylonitrile, plexiglass and other resins. Transparent products have a better stability than colored products. The product dosage is between 0.0% and 0.5%.

Ingredients: 2,4-dihydroxybenzophenone

The product is a white powder or needle-shaped light colored crystals. Moisture content <0.5%. Ash content 0.5%. Melting point 136~149. It is soluble in acetone (methanol), ethanol, N-methylpyridone, dioxane and N-methylpyridone. However, it is insoluble in n-heptane, water and benzene. This product is very soluble in acetone, benzene, ethanol, and water (g/100ml of solvent).

This UV absorber is suitable for coatings, synthetic rubber, polyvinylchloride, polystyrene and unsaturated polyester. The wavelength range of absorption is 280-340nm and the dosage is generally 0.1%-1%. The light stabilization effects of this product are not very impressive.

Ingredients: 2-hydroxy-4-methoxybenzophenone

The product is available in a white or light yellow crystalline powder. Density 1.32g/cm3. Melting point 62-66. Boiling Point 150-160 (0.67kPa), 240 (2.4kPa). Solvable in most organic solvents, such as acetone, ketone, benzene, methanol, ethylacetate, and methyl ethylketone. Insoluble in water. This product is soluble in benzene, n-hexane, ethanol (95%), carbon tetrachloride, styrene, and DOP.

This UV absorber is suitable for plastics like polyvinylchloride, polyvinylidenechloride, polymethylmethacrylate (PMMA), unsaturated polyester resin, ABS resin, cellulose resin. It has an absorption range of 28340nm and a dosage of 0.1%1.5%. It is thermally stable and doesn’t decompose after 200. It is suitable for transparent light-colored products because it absorbs very little visible light. This product is also suitable for paints and synthetic materials.

Japan and Italy specify that the maximum dosage of this product in products that are used to contact food is 0.3%.

Ingredients: 2-hydroxy-4-n-octyloxybenzophenone

Performance and use: This product is a light yellow or white crystalline powder. Density 1.160g/cm3 (25). Melting point 48~49. Soluble in acetone, benzene, ethanol, isopropanol, slightly soluble in dichloroethane, insoluble in water. The solubility of this product in some solvents (g/100 solvent, 25) is acetone 74, benzene 72, methanol 2, ethanol (95%) 2.6, n-heptane 40, n-hexane 40.1, water 0.5.

This product is a UV absorber that can strongly absorb ultraviolet rays with a wavelength of 270~330nm. It can be used for various plastics, especially polyethylene, polypropylene, polystyrene, ABS resin, polycarbonate, polyvinyl chloride, which has good compatibility with resins and low volatility. The general dosage is 0.1%~1%. It has a good synergistic effect when used with a small amount of 4,4-thiobis(6-tert-butyl-p-cresol). This product can also be used as a light stabilizer for various coatings.

Safety precautions: This product has low toxicity. Many countries allow this product to be used in plasticized products that come into contact with food, such as the United States for polyolefins, the UK’s maximum dosage is 0.6%, Italy’s maximum dosage for polyethylene and polypropylene is 0.5%, Japan’s dosage is 0.5% polyethylene, 1% polypropylene, 0.5% AS resin and ABS resin, and 0.2% polyvinyl chloride (cannot come into contact with oily foods or foods with an ethanol content of more than 20%).

Ingredients: 2-(2′-hydroxy-3′, 5′-di-tert-phenyl)-5-chlorobenzotriazole

Performance and use: This product is a UV absorber, and its characteristics and uses are similar to UV-326. It can strongly absorb ultraviolet rays with a wavelength of 270-380nm, has good chemical stability, and extremely low volatility. Good compatibility with polyolefins. It is especially suitable for polyethylene and polypropylene. In addition, it can also be used for polyvinyl chloride, polymethyl methacrylate, polyoxymethylene, polyurethane, unsaturated polyester, ABS resin, epoxy resin and cellulose resin. This product has excellent resistance to heat sublimation, washing resistance, gas fading resistance and mechanical property retention. It has a significant synergistic effect when used in combination with antioxidants. To improve the thermal oxygen stability of products. The general dosage of this product in plastics is 1% to 3%.

Safety precautions: This product has low toxicity. Japan, the United States, France, and Italy allow this product to be used in polyolefin plastics that come into contact with food, with a maximum dosage of 0.5%. For other plastics that come into contact with food, the maximum dosage specified in Italy is 0.2%, and Japan and France are 0.5%.

Ingredients: Monobenzoic acid resorcinol ester

Performance and use: This product is a white crystalline powder. Melting point 132-135, boiling point 140 (20Pa). Bulk density 0.68g/cm3 (20%). Soluble in acetone and ethanol, slightly soluble in benzene, water, n-heptane, etc.

This product is a UV light stabilizer, and its performance is similar to that of benzophenone light stabilizers. It is mainly used for polyvinyl chloride, cellulose resin, polystyrene, and the general dosage is 1% to 2%.

Ingredients: 2,2′-Thiobis (4-tert-octylphenoloxy) nickel

Performance and use: This product is a green powder. The absorption peak in the ultraviolet region is 290nm (in chloroform), which is suitable for polyolefin plastics such as polyethylene and polypropylene. It has a particularly good light stabilization effect on film and fiber products, and can improve processing performance. This product has a good synergistic effect when used in combination with ultraviolet absorbers, or further improves the light stabilization efficiency. Its main disadvantage is that the color is darker, which makes the product colored. At the same time, it assists in antioxidant action with thioesters at high temperatures, making the product gray-black.

Safety precautions: This product is toxic and should be used with caution.

Ingredients: tris (1,2,2,6,6-pentamethylpiperidinyl) phosphite

The product is white, crystalline powder. Melting point 122 ~ 124 . It is soluble in acetone and chloroform but difficult to dissolve in water.

This product is an inhibited light stabiliser. It does not absorb ultraviolet rays but can decompose and transfer energy from excited molecules. The light stabilization is 24 times greater than that of ordinary ultraviolet absorbers. This product can be used with plastics like polyethylene and polyethylene. It is low-toxic, has a good processing performance and good compatibility with polymers. It has a good thermal oxidation resistance, as well as a mild stabilizing effect. This product is not suitable for use with hot water mediums over a long period of time due to its poor heat resistance. This product is also processed and used below 270 degrees Fahrenheit. Weight loss becomes more severe when this temperature is exceeded.

Ingredients: 4-benzoyloxy-2,2,6,6-tetramethylpiperidine

Performance and usage: This is a white powder. Melting point 95 to 98 degrees, decomposition temperatures above 280. It is soluble in acetone (acetone), ethanol, toluene and ethyl-acetate.

This product is an inhibited light stabiliser. This product has almost no capacity to absorb ultraviolet light, but can capture the free radicals that are generated when polymer materials are exposed to ultraviolet rays. It is therefore able exert the effect of light stabilization. This product can be used with a wide range of plastics, including polypropylene and polyethylene. It is also suitable for polyurethane and polyamide. This product has a light resistance that is many times greater than the average ultraviolet absorber. It has excellent heat resistance, processing properties, and is non-coloring and non-polluting. When combined with antioxidants or ultraviolet absorbers, it has excellent synergistic properties.

Ingredients: 2,4,6-tris (2′-butoxyphenyl) -1,3,5-triazine

The product has a yellowish powder. Melting point 156~165. It is soluble when heated in hexamethylphosphorictriamide.

This UV absorber can absorb ultraviolet radiation with a wavelength between 300380nm. This product is suitable for many plastics, including polyvinylchloride, polyoxymethylene and chlorinated polyether. It is not recommended to use more than 1%. This product’s light stabilization is superior to UV-9 and UV-531. However, it has colorant properties that can turn the product light yellow. Its compatibility with resin also is poor.

Ingredients: Hexamethylphosphoric triamide

Performance and Use: This product has a clear, colorless liquid. It is transparent with a slight fishy smell. The density of the liquid is 1.02531.0257g/cm3 (20), boiling point 116117 (1.48kPa), and refractive index 1,45821.4589 (22). It can be dissolved in both polar and nonpolar solvents.

This product is a good light stabilizer. This product can be used to give polyvinyl a great anti-aging effect outdoors. It is also known as an effective weathering agent. This product can be added to polyvinyl film in quantities of 2-5 parts. It will not only improve the weather resistance and cold resistance but also lower the processing temperature. This product is also an excellent solvent for polymer materials like polyamide, polyurethane and urea-formaldehyde.