TOKYO, May 14, 2015 _ Ube Industries, Ltd. announced today that it has succeeded in synthesizing the world's first high-dispersion strontium carbonate nano particles for optical applications.
Retardation films*1 used today for optical film applications such as LCDs and organic electroluminescent (EL) displays are made from multiple layers of resin films. The drawback to these films is their complex manufacturing process and high cost.
To address these issues, single-layer retardation films are being developed using resins formulated with inorganic filler additives. Strontium carbonate is a promising inorganic filler, due to its controllable optical properties. However, synthesizing nano-size particles was difficult until now using existing techniques, as was achieving adequate dispersion in solvents.
Ube Industries has developed a proprietary gas-liquid reaction method*2 that enables the synthesis of nano-size (20-30 nm) acicular strontium carbonate particles. In addition, Ube Industries has achieved a high dispersity with greater than 90% transmittance in organic solvents by applying a new surface treatment process.
Resins formulated with the newly developed strontium carbonate nano particles enable manufacturing of ultra-high transparency films with less than one percent haze.
Application of strontium carbonate nano particles for optical films used in LCDs and organic EL displays will improve performance, by delivering wider viewing angles and enhanced image clarity.
Ube Industries is currently studying surface treatment processes that are suited for different resin formulations containing strontium carbonate nano particles, advancing the development of inorganic fillers with properties that are tailored to customer requirements.
Moving forward, Ube Industries will broadly provide evaluation samples in the optical materials sector for retardation film applications, in an effort to facilitate adoption in the display market. The company will also study applications besides films, namely the use of strontium carbonate nano particles in condensers and LED phosphors.
High-dispersion strontium carbonate nano particles viewed under a scanning electron microscope