Triarylalkyl Borate Salts as Coinitiators in NIR Photopolymer Compositions

A photopolymer composition comprising

• a) matrix polymers,
• b) writing monomers,
• c) at least one photoinitiator system,
• d) optionally, at least one non-photopolymerizable component,
• e) optionally, catalysts, radical stabilizers, solvents, additives and other auxiliaries and/or adjuvants,
• wherein the at least one photoinitiator system c) consists of at least one dye and at least one coinitiator, wherein
• at least one of the dyes has a structure according to formula (II)
• in which
• R205 stands for hydrogen, halogen, C1 to C4 alkyl, C1 to C4 alkoxy or NR210R211,
• R206 stands for hydrogen, halogen, C1 to C4 alkyl, C1 to C4 alkoxy or NR212R213,
• R201 to R204 and R210 to R213 each stand independently of each other for hydrogen, C1 to C16 alkyl, C4 to C7 cycloalkyl, C7 to C16 aralkyl, C6 to C10 aryl or a heterocyclic radical,
• NR201R202, NR203R204, NR210R211 and NR212R213 stand independently of each other for a five- or six-membered saturated ring attached via N, which may additionally contain an N or O and/or may be substituted by nonionic radicals,
• R207 to R209 stand independently of each other for hydrogen, C1 to C16 alkyl, C4 to C7 cycloalkyl, C7 to C16 aralkyl, C6 to C10 aryl, halogen or cyano,
• the two optional bridge groups X1 and X2 stand independently of each other for SiR214R215, CR216R217 or O, and
• R214 to R217 stand independently of each other for hydrogen or C1 to C4 alkyl and
• An− stands for an anion selected from halide, perchlorate, tetrafluoroborate, hexafluorophosphate, hexafluoroantimonate, tetraarylborate, triarylalkylborate, nitrate, cyanide, tosylate, trifluoromethylsulfonate, bis(trifluoromethyl)sulfonimide, azide, methylsulfonate, phosphate, hydrogen phosphate, dihydrogen phosphate, sulfate, hydrogensulfate, an arbitrarily substituted carboxylate, an arbitrarily substituted organic mono- or di-sulfonate, or an arbitrarily substituted organic mono- or di-carboxylate,
• and the at least one coinitiator has a calculated oxidation potential Eoxcalculated, determined according to the formula (1) below by the quantum mechanical calculation of the Gibbs energies at 298 K of the ground state and the oxidized state of the triarylalkylborate after geometry optimization, consisting of conformer energy minimization by means of the AM1 force field followed by ab initio conformer energy calculation based on the previously determined molecular geometry coordinates, in the solvent acetonitrile under solvent field correction according to the PCM method, in the range from 1.01 V to 1.31 V against the saturated calomel electrode (SCE) in acetonitrile
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• 23.061
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