Photoacid and Photobase Generators: Prospects and Their Use in the Development of Polymeric Photosensitive Systems

Abstract

This article describes the recent progress in the preparation of a set of compounds which can generate acids or bases upon irradiation of light. These compounds are called photoacid generators and photobase generators, respectively. Photoacid generators can be divided into two groups according to their characteristics; i.e., ionic- and non-ionic compounds. Photobase generators are fewer than photoacid generators. These compounds are widely used in the field of polymeric photosensitive systems such as photoinitiated polymerization, photoinduced crosslinking of polymers and oligomers, photoinduced degradation of polymers, and photoinduced transformation of functional groups in polymer chains. In particular, this article focuses on the applications of photoacid and photobase generators to promote the development of photoresist and UV curing materials.

Photo-Induced Thermal Crosslinking of Epoxy Compounds by the Use of Quaternary Ammonium Salts Having Phenacyl Groups.

“…Cobalt-amine complexes, carbamates and 0-acyloxime were reported as the photobase generators and their details are introduced in reviews [1,2].…”

Direct and Sensitized Photolysis of Cyclic Iodine Compounds as Photo-acid Generator

“…By recrystallization from dichloromethane, BIO-BF 4 as a colorless crystal (0.101 g) was obtained. 1 Preparation of BIO-OTs: BIO-Cl (1.50 g, 3.71 mmol) was added to silver p-toluenesulfonate (1.15 g, 4.14 mmol) in acetonitrile (67 mL) and the solution was stirred at r.t. for 1 h. The solution was filtrated through a Celite pad, and the solvent was removed.…”

I-Line Sensitive Photoacid and Photobase Generators and Their Use for Photocrosslinking System Based on Poly(vinylphenol) and Diepoxy Fluorene Derivatives.

“…The isosbestic points were observed at 285 nm and 315 nm. The increase in absorbance at 350 nm is due to the formation of fluorenone azine [3]. It is supposed that the cleavage of -0-N bonds of imino sulfonates and the subsequent abstraction of hydrogen atom lead to the formation of azine and ketone on irradiation at 366 nm.…”

“…Photoacid generators and photobase generators can be used as an initiator for the photoinduced crosslinking [2,3].…”

“…9-Fluorenylideneimino p-toluenesulfonate (FITS) [3] and PaAnO [5] were prepared as reported previously. Other reagents were purchased and used without further purification.…”