| abstract |
Bisacyl-bisphosphine oxides and sulphides of formula (I) are new: X, Y = O or S; R1, R2 = 4-8C tert. alkyl, or a cyclopentyl, cyclohexyl, phenyl, naphthyl or biphenyl gp., opt. substd. by halogen, 1-4C alkyl and/or 1-4C alkoxy; R3, R4 = 1-18C alkyl, or a cyclopentyl, cyclohexyl, phenyl, phenyl-(1-4C)-alkyl, naphthyl or biphenyl gp., opt. substd. by halogen, 1-12C alkyl and/or 1-12C alkoxy; or R1 + R2 and/or R3 + R4 = 5-6-membered heterocycle contg. S or N. Also claimed are: (a) the corresp. bisacylphosphine (IA), with the exception of cpds. in which R1 - R4 = phenyl or t-Bu if R1 = R2 = R3 = R4 or R1 = R2 and R3 = R4; (b) photopolymerisable compsns. contg. (I) as photoinitiator; (c) a method for photopolymerisation of ethylenically unsatd. cpds.; and (d) a substrate with hardened coating(s) of the compsn. |