Mar. 25, 2019
Toray Industries, Inc.
Toray Develops Innovative Flexible Clear Film
-Achieves ultra-high hardness and bending resistance -

 Toray Industries, Inc. (head office: Chuo-ku, Tokyo; President: Akihiro Nikkaku; hereinafter referred to as “Toray”) announced today that it had developed a clear aramid film that is as hard as glass and can withstand a bending radius of 1 mm. The developed material is expected to be applied in a wide range of fields such as optical films for flexible displays and transparent circuit boards. Toray has already established the technology on a pilot scale and will drive forward discussions aimed at mass production.  The development of foldable and rollable displays is gathering pace in recent years, which has led to requirement for films with high hardness and flexibility that can replace the glass used for the cover window, the top most layer of display.  Aramid is a super engineering plastic with excellent hardness and heat resistance and Toray’s aramid film mictron® is the only commercially available aramid film in the world. Based on this technology, the company employed its proprietary polymer design and membrane forming technology and developed the colorless and transparent aramid film with high hardness and heat resistance.  Further, it treated the surface of the clear aramid film with specially designed process to realize ultra-high hardness of 9H and bending resistance that can withstand bending of more than 1 million times at a bending radius of 1 mm. Using this film as cover window is expected to realize thin and highly designable flexible display with scratch-resistance as good as glass. The key technological points of the material are as follows:

1. Aramid polymer design technology
 While ordinary aramid is colored polymer, Toray succeeded in the development of a colorless and transparent aramid polymer by employing its proprietary polymer technology, which enabled the polymer to maintain its hardness and heat resistance.
2. Precision membrane production technology
 By deepening its solution film making technology, Toray succeeded in drawing out aramid’s characteristics to the utmost limit, realizing high hardness and heat resistance with an Young’s modulus of 10 GPa, the world’s highest for clear film, and a coefficient of thermal expansion of 5 ppm/K or lower.
3. Surface processing technology
 Toray developed a dedicated coating layer to clear aramid film. It is a hybrid of organic and inorganic layers combining high hardness nanoparticles and polymer dispersants. The ultra-high hardness was realized by high-density-packed and homogeneous array on the aramid film, which is extremely hard and not easily deformable, and bending resistance was achieved by controlling the affinity between aramid film and dispersant.
 By making full use of its core technologies such as synthetic organic chemistry, polymer chemistry, biotechnology and nanotechnology, Toray is promoting research and technology development for innovative materials that have the ability to change the society. Toray will continue to embody the Group’s corporate philosophy since its inception of “contributing to the society through the creation of new value with innovative ideas, technologies and products”.