Ability of Naphthoquinondiazide Photoresists to Exothermic Decomposition

Abstract

The article considers two intermediate products of positive photoresists (1,2-naphthoquinonediazide-(2)-5-sulfonic acid of monosodium salt — Dye M and 1,2-naphthoquinonediazide-(2)-5-sulfochloride — Dye N2) from the standpoint of the tendency to explosive transformation. The experimental values of flash points determined on the OTP setup were 130 °C for Dye M and 95 °C for Dye N2. These values are close to the temperatures of the beginning of intensive exothermic decomposition (132 and 111 °C, respectively) obtained by thermogravimetric analysis. In addition, this analysis showed the presence of exothermic peaks in the studied samples both in the air and in an inert atmosphere of helium, which is a necessary condition for the manifestation of a tendency to explosive transformation. To confirm the possibility of explosive transformation, the flash points of substances were also determined by the calculation method according to the formula, which is a consequence of the problem of thermal explosion during convective heat exchange with the environment, and gave a result close to the experimental one (the values were 138 and 105 °C, respectively). For this calculation the following was used: the kinetic parameters determined by the Kissinger method, the values of the density of substances determined on an automatic pycnometer, as well as the values of the heat of explosive transformation obtained with the help of the Real computer thermodynamic program. The research results confirming the tendency of the investigated compounds to explosive transformation, as well as the critical temperatures, exceeding which is unacceptable, were transferred to the production of FGUP GNTs NIOPIK to create a safe technological process, safe storage and transportation conditions. Considering the accuracy of the measuring devices, the process temperature should not exceed 125 °C for Dye M and 90 °C for Dye N2. The conducted studies and calculations show that the computational and experimental approaches have good convergence, give values in a close temperature range, and increase the reliability of the obtained results.