Abstract: A photopo1ymerisation process for the production of mouldings from methacrylate casting resins wherein 1) a methacrylate casting resin formulation containing (A1)>50% methyl methacrylate and/or a prepolymerisate containing a high proportion of methyl methacrylate, (A2) 0 to 40% other monomers than can be copolymerised with methyl methacrylate, (B) 0.1 to 10% at least one mono- or bis-acyiphosphine oxide photoinitiator, C) 0 to 10% other photoinitiators, D) 0 to 5% thermal initiators and E) optionally further customary additives is cast in a mould and 2) is fully cured by irradiation with a light source in the range of from 200 to 800 nm to form a mechanically stable moulding.

Abstract: Photoinitiator combinations comprising at least one compound of formula (I)  wherein R1 is C1-C4alkyl, C1-C4alkoxy or halogen; R2 is hydrogen, C1-C4alkyl, C1-C4alkoxy or halogen; R3 is, for example, C1-C20alkyl, cyclopentyl, cyclohexyl, phenyl-C1-C4alkyl, naphthyl or biphenylyl or an O-, S- or N-containing 5- or 6-membered heterocyclic ring; and at least one compound of formula (II)  wherein R1 and R2 are as defined above; R9 is, for example, C1-C20alkyl, cyclopentyl, cyclohexyl, phenyl-C1-C4alkyl, naphthyl, biphenylyl or an O-, S- or N-containing 5- or 6-membered heterocyclic ring; and R10 is, for example, C1-C20alkyl, C2-C20alkyl interrupted by one or more O atoms, cyclopentyl, cyclohexyl, phenyl-C1-C4alkyl, naphthyl, biphenylyl or an O-, S- or N-containing 5- or 6-membered heterocyclic ring; are reactive photohardeners causing only a low degree of yellowing in the cured substrates.

Abstract: Photoinitiator combinations comprising

Abstract: Photoinitiator combinations comprising at least one compound of formula (I) R1 is C1-C4alkyl, C1-C4alkoxy or halogen; R2 is hydrogen, C1-C4alkyl, C1-C4alkoxy or halogen; R3 is, for example, C1-C20alkyl, cyclopentyl, cyclohexyl, phenyl-C1-C4alkyl, naphthyl or biphenylyl or an O—, S— or N-containing 5- or 6-membered heterocyclic ring; and at least one compound of formula (II) R1 and R2 are as defined above; R9 is, for example, C1-C20alkyl, cyclopentyl, cyclohexyl, phenyl-C1-C4alkyl, naphthyl, biphenylyl or an O—, S— or N-containing 5- or 6-membered heterocyclic ring; and R10 is, for example, C1-C20alkyl, C2-C20alkyl interrupted by one or more O atoms, cyclopentyl, cyclohexyl, phenyl-C1-C4alkyl, naphthyl, biphenylyl or an O—, S— or N-containing 5- or 6-membered heterocyclic ring; are reactive photo hardeners causing only a low degree of yellowing in the cured substrates.