SYNTHESIS OF DIAZORESIN AND ITS PHOTO-CROSS-LINKING REACTION

Diazoresins with different specific viscosities were prepared from dip henylamine-4-diazonium salt and paraformaldehyde in concentrated sulph uric acid with different ratios of CH2O/-N2+X-. In order to obtain a d iazoresin with a specific viscosity in a given time at 0-5 degrees C, more than a stoichiometric ratio was necessary. The photocrosslinking reaction of the diazoresins with various binder resins in solid film w as investigated. The results show that the photocrosslinking reaction took place only in a system composed of diazoresin and binder resin co ntaining -OH side-chain groups. The photodecomposition of diphenylamin e-4-diazonium salt and its diazoresin in alcohol was studied. It was d emonstrated that the diphenylamine aryl cation formed on decomposition is the dominant intermediate. The photocrosslinking mechanism between diazoresin and binder resin is discussed in a preliminary way. (C) 19 98 SCI.