Studies On Photosensitive System Comprising Thioacridone For Use In Direct-Making Plate Material With Photosensitive Resin

In this paper, some work has been done in the synthesis of sensitizers for use in direct-making plate material with photosensitive resin and the relevant base study as follows: l.Six kinds of novel thioacridones and eight sorts of acridones were synthesized. The structures of intermediates and objective products were confirmed by IR, MS analysis methods. 2. The photosensitivity of ten sorts of thioacridones , such as the maximum absorption wavelength, smax and photodecomposition speed constant, was researched.3.Using Xe lamp as light source, the effect of the photosensitive system consisted of different construction of thioacridone, diphenyl iodonium salt and activator on the sensitivity for photosensitive coating layer was investigated.4.The kinetic study of photopolymerization of methacrylate(MMA) was carried out by using dilatomer under Xeon lamp, wherein the initiating system comprises different thioacridone.iodonium salt or thionium salt, and activator.5.The sensitivity of the coating layer containing different thioacridone to Argon-ion was tested.The result shows that the sensitivity of four kinds of thioacridones without group on the acridone ring is better than that of six sorts of thioacridones having group in 4-position, and that the photosensitive initiating system comprising thioacridone, activator ,and onium salt can effectively initiate the photopolymerization of MMA under Xe lamp, additionally , the kinetic equation of polymerization is Rp=K[NBTA]?8[DMDPI]?d6 [TS]M[MMA]0H at 30癈, whereby NBTA referring to N- (n-butyl) thioacridone, DMDPI referring to dimethyldiphenyl iodonium salt, and TS referring to thiosalilylic acid, and that the synthetical photosensitivity of NBTA and N- (n-propyl) thioacridone(NXTA) is better than other thioacridones ,the sensitivity of the coating layer containing each of them to Argon-ion laser or Xe lamp of is higher than others.