Toray Develops Hydrophilic Coating Material That Enhances Water Wettability of Silicone Materials by Over 20 Times

Toray Industries, Inc. (headquartered in Chuo-ku, Tokyo; President and CEO: Mitsuwo Oya; hereinafter "Toray") has developed a hydrophilic coating material that enhances the water wettability of silicone materials by over 20 times. This innovation enables durable hydrophilicity to be imparted to silicone materials, with broad applications anticipated in medical devices such as contact lenses.

Silicone materials are widely used in medical devices including contact lenses and catheters due to their flexibility and biocompatibility. However, their inherent hydrophobicity presents challenges in applications requiring water wettability and lubricity. For example, contact lenses may cause dryness or foreign body sensation, while catheters may suffer from reduced operability or occlusion risks. Although surface modification and material reformulation have been explored to improve hydrophilicity, these approaches often complicate manufacturing processes and have struggled to achieve sufficient hydrophilicity and durability for clinical use.

Leveraging its proprietary polymer molecular design and precision polymerization technologies, Toray has created a novel hydrophilic polymer with high affinity for silicone materials. By utilizing the self-organizing properties of this polymer, a highly durable, nanometer-thin hydrophilic coating layer can be easily formed on silicone surfaces. Due to its ultra-thin nature, the coating imparts hydrophilicity without compromising the inherent physical properties of the silicone material. For instance, by simply applying the hydrophilic polymer to the surface of commercially available silicone hydrogel and heating it, a hydrophilic coating layer of approximately 20 nm is formed. Compared to uncoated materials, water wettability improves by over 20 times, and the coefficient of friction is reduced by about 90%. Furthermore, these effects persist even after abrasive washing, demonstrating exceptional durability.

Application of this hydrophilic coating to contact lenses is expected to enhance comfort during extended wear. Additionally, since the coating has demonstrated suppression of biological component adhesion on silicone elastomers, its use in stents and catheters could reduce occlusion risks and improve operability through enhanced lubricity. Toray will now actively promote this coating material and expand its application to a wide range of medical device materials.

Going forward, Toray will continue striving to create healthcare products that support healthy, independent living by developing advanced materials and innovative technologies, aiming to realize a world where everyone can lead a healthy and hygienic life.