Photopolymerization Analysis by Isomerization for Oxime Derivatives

• Published in: Journal of Photopolymer Science and Technology Vol. 24; no. 6; pp. 625 - 629
• Main Authors: Shiota, Dai, Tadokoro, Yoshinori, Noda, Kunihiro, Shida, Masaru, Fujii, Masaaki
• Format: Journal Article
• Language: English
• Published: Hiratsuka The Society of Photopolymer Science and Technology(SPST) 01.01.2011; Japan Science and Technology Agency
• Subjects: Curing; EGA; geometrical isomer; Isomerization; Isomers; oxime ester; Oximes; Phenyls; photoresist; Photoresists; Polymerization; Radicals; resin black matrix
• ISSN: 0914-9244; 1349-6336
• DOI: 10.2494/photopolymer.24.625

Negative photopolymerizing photoresists can be cured in a short time, as compared to thermosetting photoresists, and have advantages in reducing the energy, cost and volatile organic compound (VOC) generated therefore. They are utilized as a curing system for large-size liquid crystal panels, of which sizes are lengths more than 2 m. Therefore, novel photo polymerization initiators, which generate radicals more efficiently, have been investigated. However, compounds which substitute phenyl group in the oxime end have promptly occurred to E/Z-isomerization around C=N bonds. This isomerization remarkably decreases quantum yield of radical production in N-O bond cleavage. The authors investigate the influence to photolithography by the isomeric structure of O-acyloxime ester compounds and the selective synthetic process of isomeric structure. Consequently, a selective isomer synthesis method for E and Z isomers has been established by controlling the reaction temperature. Furthermore, evaluations of the pattern formation using these isomers areperformed. The evaluations have revealed that patterns are formed by using the E isomer with lower energy than that required by using the Z isomer.