Chimassorb 81 Methanone 2 hydroxy 4 octyloxy phenyl 1843-05-6 Ciba Light stabilizer / UV-absorber >> Benzophenone Architectural / Decorative >> Interior Architectural / Decorative >> Exterior CHIMASSORB 81 is a solid UV-absorber of the 2-hydroxy-benzophenone class. Methanone, 2-hydroxy-4-(octyloxy)-phenyl Molecular weight: 326.4 CAS No. 1843-05-6 CHIMASSORB 81 significantly improves the resistance of clear coatings to failures upon exposure to sunlight such as discoloration, cracking, loss of gloss and loss of adhesion. Its performance in outdoor applications can be improved further by use in synergistic combination with a hindered amine light stabilizer (HALS) such as TINUVINÒ 292 or TINUVIN 123. Use of CHIMASSORB 81 should be reserved for applications where expectations of the final coating’s durability are moderate since the light stability of 2-hydroxy-benzophenone derivatives is known to be limited. For better long-term performance use of UV-absorbers of the benzotriazole class e.g. TINUVIN 1130 or TINUVIN 384 is recommended. The amount of CHIMASSORB 81 required for optimum performance should be determined in trials covering a concentration range. Solid UV-absorber of the 2-hydroxy-benzophenone class. Improves the resistance of clear coatings to failures upon exposure to sunlight such as discoloration, cracking, loss of gloss and loss of adhesion. Its performance in outdoor applications can be improved further by use in synergistic combination with a hindered amine light stabilizer (HALS). Should be reserved for applications where expectations of the final coating’s durability are moderate since the light Stability of 2-hydroxy-benzophenone derivatives is known to be limited. Recommended usage level: for interior clear coating, 1.0-3.0%; for exterior clear coating 1.0-3.0% + 0.5-2.0% (HALS), concentrations are based on weight percent binder solids.