Copolymers for optical data storage

#The invention relates to mixed polymers and the use of the latter for optical data storage.

#Photoaddressable polymers are known (Polymers as electrooptical and fotooptical active media, V. P. Shibaev (ed.), Springer Verlag, New York 1995). Particularly suitable for this purpose are side-group polymers, of which the group of the copolymers is distinguished by very wide possibilities in the variation of the properties. Their special peculiarity is that their optical properties such as absorption, emission, reflection, birefringence, scatter may be changed reversibly by light induction. Polymers of this kind have a particular comb-like structure: on a linear spine sit—connected by molecule parts acting as spacers—side groups which may absorb electromagnetic radiation. Examples of this kind are dye molecules, in particular the side-group polymers containing azobenzene groups according to U.S. Pat. No. 5,173,381. Said substances are characterised by the capacity to form a directional birefringence when irradiated with polarised light. The inscribed birefringence patterns may be made visible in the polarised light.

#It is furthermore known that there may be inscribed in layers of said polymers at any point with polarised light a locally limited birefringence whose main axis moves in sympathy on the rotation of the polarising direction (K. Anderle, R. Birenheide, M. Eich, J. H. Wendorff, Makromol. Chem., Rapid Commun. 10, 477-483 (1989), J. Stumpe et al., 20th Freiburg Working Conference on Liquid Crystals 1991).

#16

#To a solution of 125 g of 4-(2-methacryloyloxy)-ethoxy-benzoic acid chloride in 200 ml dioxane are added 85.9 g of 3-aminodiphenyl ether in 200 ml dioxane, the whole is stirred for 2 h and the product is precipitated by pouring of the solution into 2 l of water. The precipitate is drawn off, dried and purified by twice repeated recrystallisation out of isopropanol. The yield amounts to 40% of theoretical. M.p.=111° C.

#Ultimate analysis: C25H23NO5 (417.47)