Abstract:
Photo-cureable coating formulations which comprise a durable and/or red-shifted hydroxyphenylbenzotriazole ultraviolet light absorber (UVA) are effectively photocured employing a combination of α-hydroxy ketone and bisacylphosphine oxide photoinitiators. The combination of the photoinitiators bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 1-hydroxycyclohexylphenylketone is especially effective for this purpose.
Abstract:
2H-Benzotriazole UV absorbers substituted at the 3-position or at the 5-position of the phenyl ring by a 1,1-diphenylalkyl moiety, particularly a 1,1-diphenylethyl group, are particularly photostable in automotive coatings, and are of low color and exhibit low volatility in thermoplastic compositions.