Positive-working photoresists containing tetrahydropyranyl group as an acid-labile polymer for rainbow holograms

Various molecular weights of acid-labile polymers of tetrahydropyranyl meth acrylate/3(4)-methylstyrene were evaluated as visible light sensitive posit ive-type photoresists for their application on rainbow holograms. The exper imental results show that diffraction efficiency, S/N ratio and contrast of a reconstructed image from a rainbow hologram were influenced by the avera ge molecular weight (Mn); the copolymer with Mn = 5 - 8 x 10(4) gave better results and with a minimum exposure energy of 3.2 mJ/cm(2) using 488 nm la ser light. It is possible to be applied to the production of the stamper fo r embossed holograms by means of using this copolymer.