USE OF HYDROXYALKYLPHENONES AS INITIATORS FOR THE RADIATION HARDENING OF AQUEOUS PREPOLYMER DISPERSIONS

摘要

Hydroxyalkylphenones of formula I IMAGE wherein R is hydrogen, halogen, alkyl of 1 to 18 C atoms, alkoxy of 1 to 4 C atoms or IMAGE Ra is hydrogen, halogen or alkyl of 1 to 4 C atoms; R1 and R2 (a) are each alkyl of up to 14, together 4 to 16, C atoms or together are alkylene of 4 to 8 C atoms, if R is hydrogen, halogen, alkyl of 1 to 6 C atoms or alkoxy of 1 to 4 C atoms, or (b) are each alkyl of 1 to 6 C atoms or together are alkylene of 2 to 8 C atoms, if R is alkyl of 3 to 18 C atoms or IMAGE R3 and R4 are each alkyl of 1 to 6 C atoms or together are alkylene of 2 to 8 C atoms and Z is -CO-, -CH2-, -O- or -S-; are suitable as initiators for radiation curing aqueous prepolymer dispersions. They have good stability in aqueous systems and also upon removal of the water from these systems, and they have a considerably increased reactivity in their ability to initiate the curing of aqueous systems curable by radiation.