A water‐soluble, reciprocity‐law‐failing photoresist

Abstract

For the purpose of obtaining a water‐soluble, reciprocity‐law‐failing photoresist, a study was made on the photo‐crosslinking properties of various systems composed of water‐soluble polymers and bisazides. Reciprocity‐law‐failing photoresists are suitable for use in the fabrication of black matrix color picture tubes without any alteration in the shadow mask. As a result, a system containing polyvinylpyrrolidone, polyacrylamide, and 4, 4′‐diazidostilbene‐2, 2′‐disulfonic acid disodium salt was found to show a significant reciprocity‐law‐failing property in the range of light intensity used practically in black matrix fabrication. The mechanism of the photo‐cresslinking reaction of this photoresist was investigated. It is suggested that the bisazide decomposes to liberate a reactive dinitrene intermediate. This photodecomposition was found to proceed reciprocally. The nitrene reacts with polymer molecules to form a water‐insoluble three dimensional network. If, however, oxygen is present, this crosslinking reaction is inhibited by a preferential reaction between dinitrene and oxygen. By this oxygen effect, this photoresist reveals significant reciprocity‐law‐failing characteristics.

Poly(vinyl alcohol)/poly(vinyl pyrrolidone) interpenetrating polymer network: Synthesis and pervaporation properties

“…DAS is a hydrophilic, diazo photocrosslinking agent, which is suitable for water‐soluble polymers. Its crosslinking mechanism was reported in previous studies 8, 10. Under UV irradiation, DAS would lose two nitrogen molecules to become an active dinitrene compound11 whose nitrene groups are either in the state of singlets or triplets 11.…”

“…The dinitrene compound would react under the more active form of the singlet11 by insertion into two CH bonds to give interchain or intrachain crosslinks with substituted amine groups. Because the tertiary carbon is the most reactive,11 the pyrrolidone‐substituted carbon atoms of PVP would react with the DAS according to the following scheme: A second reaction can also occur, especially at high DAS concentration: coupling of two DAS molecules into a dimer, whose bronze color can be easily detected 8, 10. When the dimer formation occurs, it lowers the overall efficiency of crosslinking; thus the DAS concentration was strictly controlled in the reaction system.…”

Synthesis and characterization of Nafion/cross-linked PVP semi-interpenetrating polymer network membrane for direct methanol fuel cell

“…Before photo-crosslinking, all the operations should be carried out in the dark. The photo-cross-linking mechanism and reaction formula of PVP with DAS were previous reported [13][14][15]. After irradiating, deionized water was used to completely wash off the unreacted PVP and DAS, as well as the soluble cross-linked particles (the photo-crosslinking samples were soaked in deionized water for at least 24 h, and the water was replaced every 8 h).…”

Development of high‐definition aqueous polyvinylpyrrolidone photoresists for cathode ray tubes

“…10 However, the only commercially available diazide photoactivator was DAS, which has been used with PVP, which is water soluble. 11,12 Therefore, the synthesis of azides was investigated. Several reactions for synthesizing aryl azide compounds exist.…”