Applications for Photopolymers

More applications for piiotopolymer-based products appear as technology advances. Changes are influenced hy, e.g., novel light sources (importance of near infrared radiation equipment for laser imaging), environmental considerations (avoidance of halogenated solvents), economics, and demands for improved performance. 

The choice of binders and monomers is governed by the application depending on whether the material will be used in aqueous or solvent washout systems, etc. 

Inevitably, economics play a major role in the development of formulations, and the least costly HABI and most effective chain transfer agent or coinitiator. 

An emerging application is in the field of color filters and displays. To some extent this involves modification of resist technology by incorporation of finely divided colorants that then serve to reduce transmission of certain wavelengths of light. 

Colored Resist Material Set and Color Filter. Dai Nippon Printing Co., Ltd. (May 11, 2004). Describes a set material of photoinitiators, which prevent a reduction in the light transmittance of each colored resist. The colored resist material set comprises at least colored resist materials having three colors and consisting of a red resist material, a green resist material and a blue resist 

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The advent of commercially available lasers in the late 1960 s sparked research efforts at DuPont into many new areas. In one of the early successes of this effort, E.F. Haugh in 1972 patented a unique application for photopolymers, as holographic media [1],... 

Photopolymer technology, which encompasses the action of light to form polymers and light initiated reactions in polymeric materials, is an immense topic. Previous papers in this symposium have described some of basic chemistry utilized in photopolymer technology. The primary objectives of this paper are a) to develop the connections between basic photopolymer chemistry and practical uses of the technology and b) to provide an overview of the wide variety of photopolymer applications that have been developed since the 1950 s. Every attempt has been made to make this review as inclusive as possible, but because of the extensive nature of this topic, there are many applications of photopolymer chemistry that have not been included. In addition, only limited representative references are provided since the patent and open literature for this technology are quite vast (7). 

Electronic Materials. Applications of photopolymer technology to electronic products is probably one of the largest imaging categories in terms of sales and total number of patents and publications. A wide variety of products have been developed for the production of printed wiring boards (PWB) and the manufacture of integrated circuits (IC). 

Dental Materials. One very practical application of photopolymer materials is in dental restoratives. Photopolymer chemistry has been adapted for use in composite fillings (67), surface coatings (68) and in the formation of impressions (69). 

Coatings and Surface Modifications. Probably the one application of photopolymer chemistry that has the most worldwide commercial value in terms of product sales is the use of photopolymer materials for curable coatings. Most of the wood paneling and less expensive furniture manufactured today utilize UV or electron-beam curable materials for decorative finishes (e.g. simulation of wood grain) and protective coatings. In addition, the surfaces of many commercially important materials (e.g. textile fibers and polyester films) are being modified by photopolymer processes. 

Coatings. The use of photopolymer materials for the preparation of curable coatings is highly diverse. Many of the products used at home and at work have been coated with a photopolymer material for protective and decorative applications. Just a few of the many applications of photopolymer technology include UV curable pigmented (94) and clear (95-96) protective coatings, protective furniture (97) and... 

Surface Modifications. Basic photopolymer chemistry is also being used for the surface modification of films, textiles fibers, and many other organic-based materials (104). Some of the novel applications of photopolymer technology to surface modification include the design of cell repellent treatments and in photografting of various chemical functionality onto the surface of materials to improve color retention, enhance the adhesion of antistatic chemicals or to improve staining resistance. 

Przybilla, R. Dammel, H. Rdschert, W. Spiess, and G. Pawlowski, New t hoc blocked poly mers for advanced lithographic applications, J. Photopolym. Sci. Technol. 4, 421 (1991) K. Przybilla, H. Roschert, W. Spiess, C. Eckes, S. Chatterjee, D. Khanna, G. Pawlowski, and R. Dammel, Progress in DUV resins, Proc. SPIE 1466, 174 (1991). 

Yamada S, Cho S, Lee JH et al. (2004) Design and study of silicone-based materials for bilayer resist application. J Photopolym Sci Technol 17 511-518... 

Liquid Crystal Displays (LCD). Liquid crystal displays, once limited to small devices such as calculators, are now displacing color CRT (cathode ray tube) displays in commercial quantities. The ability to fabricate these display devices at high quality and at low cost is partially due to the wider spread use of photopolymer-based materials. Photopolymer technology is being used for the alignment of liquid crystal (LC) elements (49), the orientation of ferroelectric materials (50), the synthesis of LC polymers (57) and the manufacture of color filters for liquid crystal display applications (52). 

All attempts to develop photopolymers or photothermoplasts suitable for fast and reversible recording and read-out of volume-phase holograms, however, have not gained commercial application. The most important characteristics of materials for holographic information recording are listed in Table 4 (158). 

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