Photoimageable material

Another noted and prolific Japanese author in the field of functional dyes, Masaru Matsuoka of the Laboratory of Materials Science, Kyoto Women s University, has written the second chapter, dealing with leuco-quinone dyes. These are the traditional redox leuco systems employed for so many years in the vat dyeing industry, and this chapter is an invaluable review of the chemistry of these systems, drawing on recent mechanistic and structural investigations. Applications considered include not only textile dyeing, but also other more specialized areas, such as hair dyeing, color formers, and photoimaging materials. 

A different vesicular photoimaging material consists of an assembly of lipid vesicles sensitized with rhodopsin. In one system the vesicles can be filled with a solution containing Co2+, and the solution outside the vesicles can be free of metal ions but contain a chelating indicator dye such as xylenol orange (101). The whole assembly can be coated, and when exposed to actinic radiation the vesicles are disrupted in exposed areas and release Co2+ ions, which are complexed by the dye indicator, thereby forming an image.253... 

Direct-positive photoimaging material for electrographic master preparation. 

Photoresist A photoimaging material, generally applied as a thin film, whose local solubility properties can be altered photochemically. A subsequent development step produces an image which is useful for the fabrication of microelectronic devices (e.g., integrated circuits). 

Yako, Y. Photoimaging materials, patterning thereof, and solvent-resistant colorless patterns with good profile therefrom. Jpn. Kokai Tokkyo Koho JP 2004139070, 2004 Chem. Abstr. 2004,140, 397363. 

Earlier material systems were screened epoxies, but both laminatable dry-film and Hquid uv photoimageable coatings are finding wide acceptance. These radiation-cured coatings offer high resolution and registration accuracy, and can be either epoxies or epoxy acrylates. 

The third chapter deals with leuco derivatives of the oxazine, thiazine, and phenazine dyes, and is written by Tran Van Thien, who has had many years experience in photoimaging at the 3M Research Center, Harlow. His industrial experience in leuco dyes has enabled him to produce a collation of material impossible to find elsewhere in a single review, and again recipes for the synthesis of representative examples abound. Consideration is also given to the numerous applications of these molecules in thermal and photo-imaging systems. 

Included among these would be photobarrier processing, which involves in-situ generation of flow barriers during material application, and photoimaging to allow wafer stage application of permanent, protective coatings. 

---