To obtain the subject high-performance tubular form (e.g. a belt) causing no deformation even after used for a long time under high load (at high temperatures, under pressure, under elongative force), and to provide a method for producing such a tubular form.
This heat-resistant endless tubular form is obtained by coating an imide-based heat-resistant resin on at least one side of a heat-resistant knit fabric knitted in an endless tubular fashion using part or all of polybenzobisoxazole(PBBO) fibers. Preferably, this tubular form is obtained by applying an aromatic polyamideimide on a knitted fabric made by circularly knitting wholly aromatic polyester or polyamide fibers with PBBO fibers as inserting fibers. The other objective method for producing the above tubular form comprises effectively a coating process as described above in combination with a centrifugal casting method. This tubular form is useful as an automatic belt (for power transmission through its compression or tension) or the like.
SAGO SHIGERU
TANAKA YOSHI
