Improvement of the photopolymerization and bottom-curing performance of benzocarbazole oxime ester photoinitiators with red-shifted absorption

Abstract

Highly sensitive photoinitiator takes an important role in the improvement of photo-polymerization for the advanced manufacturing of microsteric structures of the color filter. In the present work, we have investigated photosensitivity of a novel oxime ester photoinitiator with benzocarbazole as a chromophore in the polymerization process. By comparing the residual thickness of polymerized films in the color resists with those obtained by other oxime ester photoinitiators, it was found that the high absorption intensity at the i-line significantly increased the bottom-curing performance with good surface curing. Moreover, it was revealed that high quantum yield of this new photoinitiator also contributed to the increase in the high photosensitivity.

Recent advances on carbazole-based oxime esters as photoinitiators of polymerization

“…In 2022, an original approach consisted in developing benzocarbazole-based oxime esters in order to redshift their absorption towards the visible range (See Figure 13). [264] Figure 13. Chemical structure of PI-3 and reference compounds OXE-01 and OXE-02.…”

“…Figure 14. UV-visible absorption spectra of OXE-01, OXE-02 and PI-3 in acetonitrile.Reproduced with permission of Ref [264]. …”

Recent Advances on Furan-Based Visible Light Photoinitiators of Polymerization

“…In fact, photoinitiators can be divided into two distinct categories differing in how the initiating radicals are produced. Thus, Type I photoinitiators consist of dyes capable to undergo, upon excitation, a homolytic "α-cleavage" to produce free-radical species (See Scheme 1) [182][183][184][185][186][187][188][189][190][191]. In this field, benzoin ether derivatives, benzyl ketals, acylphosphine oxides, acetophenones, aminoalkyl phenones, O-acyl-α-oximino ketones, acylgermanes, α-hydroxyalkyl ketones, hydroxylalkylphenones, α-aminoketones, and oxime esters have been extensively studied [192].…”

Recent Advances on Quinoxaline-Based Photoinitiators of Polymerization

“…No tably, photoinitiators can be divided into two main categories, namely, Type I and Type I photoinitiators. In the case of Type I photoinitiators, these structures can generate reactive species by homolytic cleavage of a specific bond (See Scheme 1) [149][150][151][152][153][154][155][156][157][158]. This effort is also supported by the wide range of applications using photopolymerization.…”

“…Notably, photoinitiators can be divided into two main categories, namely, Type I and Type II photoinitiators. In the case of Type I photoinitiators, these structures can generate reactive species by homolytic cleavage of a specific bond (See Scheme 1) [149][150][151][152][153][154][155][156][157][158]. In this first family, O-acyl-α-oximino ketones, acetophenones, acylgermanes, benzoin ether derivatives, α-aminoketones benzyl ketals, acylphosphine oxides, aminoalkyl phenones, α-hydroxyalkyl ketones, hydroxylalkylphenones and oxime esters can cleave homolytically, generating initiating radicals [103,151,153,[158][159][160][161].…”