| 摘要 |
PURPOSE:To enhance the dimensional accuracy and stability of a seamless belt to enable normal transmission and rotation to be always maintained, by forming the seamless belt in such a centrifugal resin having an specific structure is rotated in a cylinder and is heated and hardened. CONSTITUTION:Polyimide resin having a specific structure as indicated by the equation after being hardened is selected as a thermohardenable resin, and is adjusted in its viscosity with the use of a suitable solvent which is preferably polyimide varnish such as N-methyl-2-pyrolidon, dimethyl acetamide or the like that does not affect badly to polyimide resin and may volatilize during the molding process. Such a thermohardenable resin solution is filled in a cylindrical mold, and is subjected to a centrifugal molding process while it is heated. Thereafter, a seamless belt-like product from which the solvent is removed off, is parted from the cylindrical mold, and is fitted onto a stainless drum for heating and hardening thereof to form a thermohardenable resin seamless belt. Accordingly, during heating and hardening of the belt-like product, the contraction of the product is very small, and therefore, it is possible to obtain a seamless belt with a high degree of dimensional accuracy an a stable and strong resin structure. |
