Irgacure photo initiator

Initiator Concentration. The K value of the calculation ought to be linearly related to photo-initiator concentration and the simulated and measured T50 values should again be linearly related. A series of UV curable transparent varnishes were made containing range of levels of the photo-initiator Irgacure 184. The coatings were applied to aluminium foil board by an R-K automatic coater at a film thickness of 6um. 

The rate constant for the propagation reaction was determined by the pulsed laser method [31], In order to avoid interference with the excitation of the monomer, a photo-initiator, which absorbs up to ca. 410 run, was selected, among others 2-benzyl-2-dimethylamino-l-(4-morpholinophenyl)butanone-l (Irgacure 369, Ciba). Using 2,2-dimethoxy-2-phenylacetophenone as photo-initiator, the propagation rate constants were not accessible for temperatures exceeding 20 °C. 

Novikova et al., reported that some pentaaza-1,4-dienes can photo initiate polymerization. Thus, l,5-Bis(4-methoxyphenyl)-3-methyl-l,4-pentazadiene, l,5-diphenyl-3-(2-hydroxyethyl)-l,4-pentaza-diene, and 1,5-diphenyl-3-methyl-l,4-pentazadiene were used as photoinitiators of radical polymerization of hexanediol diacrylate and of methyl methacrylate. Photoinitiation abilities of these compounds were compared with those of a commercial photoinitiator, Irgacure 1700. The pentaazodienes showed a high initiation capacity. Also, the activation energy of the polymerization in the presenee of the pentaazodiene compounds was lower than that for Irgacure 1700. 

Irgacure 651 is a photo-initiator (benzyl dimethyl ketone acetal) supplied by CIBA Specialty Chemicals. 

Figure 7.3 Molecular structures of representative photo-initiators and monomers employed in TPP. Peak two-photon cross-sections and excitation wavelengths for the photo-initiators are also reported. While Irgacure 369 (a) Lucirin TPO-L (b) and ITX (c) are commercially available radical photoinitiators, the symmetric stilbene-like structure in (d) with a D-Jt-A-Jt-D motif is a custom-made...

Phenylglycine derivatives were found to act as co-synergists for the iron-arene complexes when used in conjunction with dyes and amines. It should be pointed out, however, that at this time the exact identity of the photo generated species that do the initiation is still uncertain. A commercially available photoinitiator of this type is Irgacure 261, (ri -2,4-cyclopentadienyl)-l,2,3,4,5,6--[(1-methyl ethyl)-benzene]ironhexafluorophosphate " ... 

---