UV absorber-928

Химические свойства

light yellow crystalline powder

прикладной

UV absorber-928(Tinuvin 928) is a UV absorber of the hydroxyphenyl benzotriazole class developed specially for high performance coating applications. Its characteristic broadband absorption provides efficient protection to coatings and light sensitive substrates. Its excellent solubility and high thermal and environmental permanence makes it particularly suitable for coatings exposed to high temperature curing processes, such as powder and coil coatings, or high environmental stress. Tinuvin 928 is recommended for applications such as:
automotive coatings
powder and coil coatings
hot melt adhesives
exterior construction coatings (roofing, etc.)
construction adhesives and sealants

прикладной

UV-928 has broad absorption properties which can effectively protect coating and other photosensitive materials.The product has high solubility, high temperature resistant and good environmental durability and so on..It is suitable for high performance coatings, especially suitable for powder coating and industrial and automotive coatings. UV-928 can be enhanced when used in combination with a HALS stabilizer such as UV-292 or UV-123.

Синтез

In a dry argon atmosphere 0.150 g of oxime 5, 0.070 g of 1,2-phenylene diamine 1 and 0.150 ml triethyl-borate are dissolved in 4 ml dry THF and heated for 24 h at 60°C. After a TLC shows consumption of starting oxime the mixture is evaporated to dryness and the resulting residue purified by column chromatography (eluent: hexane - ethyl acetate: 10-1 vol/vol) to give 0.171 g (92 %) of the diazo-amine intermediate 6. Replacing the B(OEt)3 by 2.5 g of basic AI2O3 and the THF by 2 ml of xylene and heating this mixture to 140°C for 48 h gives after the usual work-up 0.089 mg of diazo compound 6 and 0.300 g of starting oxime 5. According the procedure given for the preparation of compound 4 in example 1, triazole 7 is obtained from 0.007 g (0.016 mmol) of intermediate amine 6 and 0.020 g (0.122 mmol) CuSO4 in 100% (0.007 g). In this comparative example, 7.73 equivalents of copper salt are used.