In this paper the pK values of both commonly commercial UV-absorbers-2- hydroxy-4-methoxy-benzophenone (UV-9) and 2,4-dihydroxy-benzophenone (UV-0) at ground and excited states have been determined.
The four color screen UV inks are made by changing the types and quantities of 9 types of photo-initiators and 11 types of pigments under the same conditions.