"Claist": Highly Functional Thin Film Made of Clay
Sensitive to water, soft and easily torn, hardened when baked but breakable : This conventional image of clay is quite different from our high-function clay material called "Claist." Claist is produced by making ordinary clay, which is highly water-retaining, into thin and flexible films using a method similar to the traditional Japanese "kamisuki" technique of paper-making. Claist shows astounding barrier performance against gases and liquids and is now being used in various industrial fields.
Claist takes the form of a film made of extremely thin layers, only 1 nm thick, of clay crystals. Claist, which is as thin as a single sheet of paper, is composed of as many as 20,000 crystal layers and shows excellent heat resistance and gas barrier performance.
Conventional gaskets (used to seal pipe joints) for high-temperature use contain some asbestos. However, Claist is an excellent alternative to such gasket materials, and is now widely used in various fields including power plants and industrial plants. Claist is also being applied to printed circuit boards and displays.
One promising application is as a barrier material for the fuel (hydrogen) tank of fuel cell cars. Since the fuel tank needs to handle hydrogen, the tank material must have excellent gas barrier performance, as well as be lightweight to save fuel. Claist is an ideal material for this purpose.