Study on Photobase Generation from .ALPHA.-Aminoketones: Photocrosslinking of Epoxides with Carboxylic Acids.

Abstract

In the conformations, the bulky benzoyl group of the aminoketone shields the amino nitrogen from acidic species present in the composition. By irradiation, the benzoyl part is cleaved and the active tertiary amine base with small substituents is eventually liberated. The investigation using model amines supported the explanation. The compositions used for this study can be utilized in the base-catalyzed imaging applications.

Simultaneous sol–gel and anionic photopolymerization of 3-(glycidyloxypropyl)trimethoxysilane via photobase catalysis

“…However, the absence of radically reactive monomers favours the disproportion and H-abstraction of the primary radicals, leading to the formation of benzaldehyde and tertiary amines. 19 In our case, the latter photolatent base was found to be relatively efficient in catalyzing the ''twin'' photopolymerization of epoxy-trimethoxysilane hybrid monomers.…”

“…In a majority of cases, however, the photolatent base systems relied on photolabile blocking groups affording weakly basic amines upon UV irradiation, with usually the requirement of a subsequent thermal treatment. 16 The photogenerated amine can act as a true photocatalyst, as reported for example in the anionic polymerization of oxirane monomers 17,18 or in various condensation reactions: epoxycarboxylic acid, 19 thiol-isocyanate, 20 hydroxyl-isocyanate, 18 acetonate/acrylate. 21,22 Alternatively, photochemically created primary amines can be directly involved in a ring-opening addition to the pending epoxide groups of a functional acrylate oligomer, leading eventually to their incorporation into the polymer network.…”

Preparation and Photo- and Thermal-Curing Properties of Copolymers Applied in Negative-Type Photoresists

“…Properties of acrylic copolymers such as their photosensitivity [5], thermal stability [6][7][8][9][10][11][12], pattern resolution [9,13], glass transition temperature [14], nanosilica-modified characteristics [8] and physical characteristics [15] have been investigated in negative-type photoresists. Properties and models of epoxy group-carboxylic acid reaction [16][17][18] have also been investigated. However, the preparation and photo-and thermal-curing properties of copolymers applied in negative-type photoresists have not been studied sufficiently.…”

UV‐activated silicone oligomer cross‐linking through photoacid and photobase organocatalysts

“…The interest in iodonium salts is mainly due to their very useful reactivity, combined with benign environmental character and commercial availability. Onium salts photoacid generators (PAG) such as 1 have been widely reported in lithography and cationic photopolymerization, while the α‐aminoketone photobase generator (PBG) 2 has found particular use in sol–gel reaction and epoxy‐carboxylic acid nucleophilic addition . Our UV‐driven approach is significantly different from previous photocuring methods based on addition photopolymerization of acrylate‐, epoxy‐based PDMS or using thiol‐ene reaction .…”