To obtain a sealing material which hardly adheres to a mating material and has a scratch-resistant surface by forming a cured thermosetting resin layer on the surface of a sealing material produced from expandable graphite.
Graphite, such as natural graphite, contg. crystals formed therein is immersed in a strong acid, such as a sulfuric acid-nitric acid mixture, for a certain time to form a graphite interlayer compd., then is washed with water, is rapidly heated to subject the C-axis direction of graphite crystals to expansion treatment, and is calendered into a 0.1-3.0 mm-thick expanded graphite sheet. On the surface of the expanded graphite sheet, a cured thermosetting resin layer contg. 0.05-0.5 wt.% silicone-based surface-adjusting agent is formed to give the objective sealing material. A water-soluble melamine resin is pref. as the thermosetting resin, though a water-soluble phenolic resin, a water-soluble acrylic resin, etc., can also be used. Examples of the surface-adjusting agent are dimethylpolysiloxane, a methylalkylpolysiloxane, an a polyethylene oxide- modified, polyalkylene ether-modified dimethylpolysiloxane.
HASUDA HARUFUMI
SEKI TOMONORI
FUJITA ATSUSHI
