UV-absorbing coating system, comprises a first and a second layer comprising UV-absorbing organic materials exhibit different absorption edges at specified wavelength, and an inorganic layer comprising titanium oxide or zinc oxide

摘要

The UV-absorbing coating system (4) comprises a first layer (1) comprising a first UV-absorbing organic material that exhibits an absorption edge at a wavelength of lambda 1, a second layer (2) following the first layer, comprising a second UV-absorbing organic material that exhibits an absorption edge at a wavelength of lambda 2, and an inorganic layer (5) comprising titanium oxide or zinc oxide, where lambda 1is greater than lambda 2. The lambda 1is 380-420 nm, lambda 2is 370-390 nm and delta lambda (calculated by subtracting lambda 1from lambda 2) is = 10 nm. The coating system is applied on a plastic substrate (3). The UV-absorbing coating system (4) comprises a first layer (1) comprising a first UV-absorbing organic material that exhibits an absorption edge at a wavelength of lambda 1, a second layer (2) following the first layer, comprising a second UV-absorbing organic material that exhibits an absorption edge at a wavelength of lambda 2, and an inorganic layer (5) comprising titanium oxide or zinc oxide, where lambda 1is greater than lambda 2. The lambda 1is 380-420 nm, lambda 2is 370-390 nm and delta lambda (calculated by subtracting lambda 1from lambda 2) is = 10 nm. The coating system is applied on a plastic substrate (3), which comprises a polycarbonate. The first layer comprises N,N'-di(naphth-1-yl)-N,N'-diphenyl-benzidine, tetra-N-phenylbenzidine, N,N'-bis-(3-methylphenyl)-N,N'-diphenylbenzidine, 1,3-bis-(4-(4-diphenylamino)-phenyl-1,3,4-oxidiazol-2-yl)-benzene, 4,4',4''-tris(N,N-diphenylamino)-triphenylamine or 4-(2,2-bisphenyl-ethen-1-yl)-triphenylamine. The second layer comprises 2-hydroxy benzophenone, cinnamic acid ester, benzylidene malonate, oxalanilide, 2-hydroxyphenyl benzotriazole, hydroxy phenyl triazine, 2,2'-methylenebis(6-(2H-benzotriazol-2-yl)-4-1,1,3,3-tetramethylbutyl)phenol or 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxy-phenol. The first and second layers are embedded in the inorganic material. An independent claim is included for preparing an UV absorbing coating system.