The world market for optical data storage media is expanding, with annual growth rates at around 10% per annum. While the potential of the conventional CD (Compact Disc) is now deemed to be exhausted, DVDs (Digital Versatile Discs), with up to 26 times the storage capacity of CDs, are set to gain further importance in future. Of the 6 to 7bn optical data storage media produced in 1998, an estimated 200m were DVDs.

Röhm GmbH (D-64293 Darmstadt) presented a new grade of PMMA at the “REPLItech Europe” specialist fair in Vienna, as a carrier material for DVDs. This is “Plexiglas DQ 501” which, according to Röhm, has an excellent transmittancy of 92% over all the wavelengths currently used by scanning lasers in DVD players. This makes it superior to polycarbonate (light transmission 89%). Norbert Wiemers, Chairman of the Röhm management, sees the “Plexiglass” DVD as a new high-volume application for PMMA.

Dow Chemical also presented a new DVD: the material used here is polycyclohexyl ethylene (PCHE). This special material should permit material-specific coding, thereby making it possible to prevent unauthorised transmission of data media contents.

Detailed information on “Plexiglas DQ” from Röhm (German): PIE-No. 43534.