The formation of amines by the photolysis of 0-acyloximes derived from acetophenone oxime, benzophenone oxime, fluorenone oxime, and 2-acetonaphthone oxime and the curing of epoxides by the resulting amines were investigated. The quantum yields of their photolysis at 366 nm in polystyrene films depend on their structures, and those for bifunctional ones bearing phenyl or naphthyl moieties were found to be very high, at 0.88 and 0.76, respectively. The yields of the resulting amines in polymer matrices were higher than those in solution. The yields for 0-acyloximes bearing a naphthyl moiety were ca. 90% and higher than for those bearing a phenyl moiety. Although the resulting amines.were efficient photo-cross-linkers for poly(g1ycidyl methacrylate), they were not effective for curing of epoxy resins (oligomers). On the other hand, polymer amines with a glass transition temperature lower than room temperature, which were obtained by the photolysis of copolymers bearing acyloxyimino groups, were found to be effective photo-cross-linkers for the epoxy resins.Key words: photo-base generator, acyloxyimino group, photo-initiated and thermal curing, poly(glycidy1 methacrylate), epoxy resin.RCsumC : On a CtudiC la formation d'amines par la photolyse d'O-acyloximes dtrivtes des oximes de l'acCtophCnone, de la benzophtnone, de la fluorhone et de I'actto-2-naphtone et la rCaction des amines qui en rCsultent avec les Cpoxydes. Les rendements quantiques de leurs photolyses h 366 nm, dans des films de polystyrkne, dependent de leurs structures; on a trouvC que ceux des composCs bifonctionnels avec des portions phCnyle ou naphtyle sont trks ClevCs, soit respectivement 0,88 et 0,76. Les rendements des amines qui en rCsultent dans les matrices de polymkre sont plus elevCs que ceux en solution. Les rendements pour les 0-acyloximes portant un groupe naphtyle sont plus Clevts (environ 90%) que ceux des acyloximes portant un groupe phCnyle. MCme si les amines qui en rCsultent sont des photorCticuleurs efficaces pour le poly(rnCthacry1ate de glycidyle), ils ne sont pas efficaces pour la cuisson des rCsines Cpoxy (oligomkres). Par ailleurs, on a trouvC que les amines polymCriques, qui se forment par photolyse de copolymkres portant des groupes acyloxyimino et qui prCsentent une temperature de transition vitreuse infkrieure i la temptrature ambiante, sont des photorCticuleurs efficaces pour les rCsines Cpoxy.Mots clks : gCnCrateur de photobase, groupe acyloxyimino, photoinitiation et cuisson thermique, poly(mCthacry1ate de glycidyle), rtsine Cpoxy. [Traduit par la rCdaction]A large number of photo-acid generators such as aromatic diazonium salts and aromatic iodonium salts have been developed and their wide use in the fields of photo-curable coatings (1)

Films of polymers bearing pendant acyloxyimino (AOI) groups become insoluble when irradiated by ultraviolet light in the presence of p-benzoquinone. Post-heating of these films after irradiation also induces further the insolubilization. In the photocrosslinking, it is deduced that p-benzoquinone serves not only as sensitizer for the decomposition of A01 groups but also as crosslinker during the photo-irradiation and heating after irradiation.

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Recently, many papers concerning photo-acid generators have been published, which include from basic research on photo-acid generators to their use in photo-resists[1]. On the other hand, although photo-base generators are very interesting compounds in UV curing, papers concerning photo-base generators are not so many compared with those of photo-acid generators. Co-amine complexes [2,3] carbamates [4,5], 0-acyloximes [6-lo] and formylated amines [ I 1 ] arc known as photo-base generators. On the way of the study of polymeric photo-base generators, we have found that 1,4benzoquinone(BQ) plays an important role in the photo-crosslinking of copolymers of 0-acryloyl acetophenone oxime (AAPO) as polymeric photo-base generators, that is, it acts not only as a crosslinker for the copolymers but also as a sensitizer for the photolysis of pendant acyloxyimino (AOl) groups [9,12]. The photo-crosslinking is deduced to occur by the reactions of polymer radicals and amino groups formed by the photolysis of A01 groups with BQ as shown in Scheme 1, because it is well known that amines react with quinones[13] and the photo-crosslinking induced Scheme I. Photo-reaction of copolymer bearing AOI Groups with BQ