PHOTO-INITIATOR COMPOSITIONS

摘要

Photo-initiator blends suitable for radiation curable ink formulations are disclosed which comprise a mixture of three or more photo-initiators, the mixture being a liquid at a temperature at or below ambient; the mixture comprising: (a) a first photo-initiator comprising an optionally substituted hydroxyC1-10 alkylC6-18aryl ketone which is liquid at ambient temperature; ( b) a second photo-initiator comprising an optionally substituted hydroxy(cycloC 3- 10alkyl)C6-18aryl ketone which is solid at ambient temperature; and (c) one or more of the following photo-initiators each of which may be optionally substituted:an alpha aminoacetophenone, a C6-18aryl(((C1-10 alkyl)1-4C6- 18arylcarbonyl))1-3 phosphine oxide, a benzophenone; a benzophenone derivati ve and/or a hydrocarbo (optionally alkyl or aryl) amino benzoate; where, (i) th e first photo-initiator (a) and the second photo-initiator (b) are present in the mixture in a weight ratio of from about 0.8 to about 1.2, (ii) the first photo-initiator (a) and the second photo-initiator (b) together comprise fro m about 15 to about 85 percent by weight of the total mixture.