Storage photopolymers

Photopolymers and photothermoplasts are mentioned only in connection with holographic data storage (see Holography). The classical method of optical data storage in silver haUde films (photographic film, microfiche technique) is not discussed (see Photography). 

Materials. For holographic information storage, materials are required which alter their index of refraction locally by spotwise illumination with light. Suitable are photorefractive inorganic crystals, eg, LiNbO, BaTiO, LiTaO, and Bq2 i02Q. Also suitable are photorefractive ferroelectric polymers like poly(vinyhdene fluoride-i o-trifluorethylene) (PVDF/TFE). Preferably transparent polymers are used which contain approximately 10% of monomeric material (so-called photopolymers, photothermoplasts). These polymers additionally contain different initiators, photoinitiators, and photosensitizers. 

Dark Stability. The examples cited have demonstrated that dye sensitized photopolymerization is potentially rapid in solution, but that substantial speed losses result when polymeric binder compositions are used in an imaging fashion. Our work has shown that TBBS activated compositions sensitized by MB can exhibit absolute photospeeds to red light that are comparable to those of commerical photopolymer systems that are sensitive only to ultraviolet wavelengths (65). These systems can offer features not now available in UV-only sensitive systems. The major failure of all such systems, however, is a pronounced lack of stability on dark storage for the lengths of time required by industry standards. 

Dumont, M., Hosotte, S., Froc, G., and Sekkat, Z. (1994). Orientational manipulation of chromophores through photoisomerization. In Photopolymers and Applications in Holography, Optical Data Storage, Optical Sensors, and Interconnects. (R. A. Lessard, cd.), Proc. SPIE 2042,2-13. 

We found that when 4.4 -diazidodiphenylamine in novolak was irradiated by UV light, novolak was in-solubilized in alkali aqueous solution and colored in blacki But it is impossible to use it as photopolymer for plate-making because 4.4 -diazidodiphenylamine is very dangerous causing explosion during storage. 

M.L. Schilling, V. L. Colvin, I. Dhar, A. L. Harris, F.C. Schilling, H.E. Katz, T. Wy-socki, A. L. Hale, L. L. Blyer, C. Boyd, Acrylate Oligomer-Based Photopolymers for Optical Storage Applications, Chem. Mater. 11 (1999) 247. 

Use Level 0.3-10% (photopolymers for imaging or info storage appiics.) 0.5-5% (other appiics.)... 

CAS 5205-93-6 EINECS/ELINCS 226-002-3 Uses Adhesion promoter, mfg. of quats, improves dyeability of textile fibers, photopolymer plates, photoresists, paint resins and emulsions, oil additives, electro dipcoats, rubber modifiers, dental compds. Properties Pt-Co 50 max. clear liq. ester-like odor m.w. 170 sp.gr. 0.94 vise. 28 cps (20 C) b.p. 134 C flash pt. 140 C ref. index 1.478 (20 C) 98.5% min. purity 0.1% water content Toxicology TSCA listed Storage 3 mos shelf life 30 C max. 

Fernandez E., Garcia C., Pascual L, Ortuno M., Gallego S. Belendez A. (2006). Optimization of a thick polyvinil alcohol-acrylamide photopolymer for data storage using a combination of angular and peristrophic holographic multiplexing. Applied optics, Vol. 45, No. 29, 7661-7666. 

Yu, D., et al. (2010). Holographic storage stability in PQ-PMMA bulk photopolymer. Optics Communications, 283, pp. 4219-4223... 

Adding fluorescent molecules to photopolymers also provides a method for optical data storage. In such a system, the fluorescent molecules bond to the polymer matrix and become more concentrated in the polymerized regions causing the required refractive index pattern (194). 

Dhar, I., Schnoes, M.G., Katz, H.E., Hale, A., Schilling, M.T., and Harris, A.L. (2000) Photopolymers for digital holographic data storage, in Holografic Data Storage (eds H. 

Boyd, C. (1999) Acrylate oligomer-based photopolymers for optical storage applications. Chem. Mater., 11, 247. 

Figure 9.11 Fabrication strategy employed by researchers at Toshiba, (a) 6.25 cm (2.5 inch) HDD glass plate used for information storage. Circular lines originate from interference colors of embossed lines, (b) SEM micrograph of CoCrPt dots formed from copolymer template in substrate grooves. Bar = 50 nm. (Reproduced from K. Asakawa et al. J. Photo-polym. Set Technol, 15, 465 (2002) copyright (2002) with permission from J. Photopolym. Sci. Technol).

Containers Photopolymers Bulk data storage (archives, etc.)... 

Characterization of the DuPont Photopolymer for Three-Dimensional Holographic Storage. 

Photopolymers are used today to make holograms. In the near future, volume holograms in multilayer materials will lead to optical data storage of unprecedented storage capacity. 

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