New manufacturing technology of high temperature resistant gas barrier film

The Japan Institute of Industry and Technology's film chemistry research laboratory has recently developed a soft, inorganic gas barrier film that can withstand temperatures up to 1 000 °C. The thin film can be applied to a gas sealing material and a solid electrolyte fuel cell separator used at a high temperature.

Previously, heat-resisting gas-barrier films were mainly made of engineering plastics, mixed with other materials according to specific needs, surface processed, or laminated in layers, and the commonly used temperature was generally limited to about 350°C. The Japan Institute of Industrial Science and Technology previously used a small amount of clay crystals as a main material to improve the gas barrier properties of engineering plastics. By optimizing the clay materials, additives, and manufacturing processes, a gas barrier film with a uniform pore-free thickness was successfully produced. Using a technique that accurately laminates clay crystals with a thickness of about 1 nm, a soft translucent gas barrier film can be made. Because clay crystals are very thin, they are flexible and do not absorb light. By precisely shaping it, a translucent shape that can suppress diffuse reflection of light can be achieved. The thickness of the film is similar to that of copy paper (3 to 10 um), and a thicker film can also be made by laminating the films in an overlapping manner. Processable film size is unlimited.

In addition, if the same method is used to cover the clay crystals onto the metal surface, a protective film can be formed. At room temperature, the permeability of the gas barrier film to inorganic gases such as helium, hydrogen, oxygen, and helium is below the test limit, far exceeding the previous engineering plastic material (Nylon 6 to oxygen transmission. The rate is 18), which is equivalent to that of aluminum foil (oxygen permeability 0). In addition, the performance does not decrease at high temperatures exceeding the melting point of aluminum foil of 660°C.