Carbon film and process for preparing the same

Abstract

(1) A carbon film derived from a polyimide film, which has a tensile strength of at least 15 Kgf/mm.sup.2, a tensile modulus of elasticity of at least 5000 Kgf/mm.sup.2 and an electric conductivity of at least 200 S/cm. (2) A process for preparing a carbon film which comprises the following steps: 1) reacting a monomer combination selected from the group consisting of a combination comprising a tetracarboxylic acid dianhydride and an aromatic diamine and a combination comprising a tetracarboxylic acid dianhydride, an aromatic diamine, and a polyamino compound having at least three amino groups to form a polyamic acid; 2) forming a film of polyamic acid; 3) imidizing the polyamic acid film to form a polyimide film having a tensile strength of at least 10 Kgf/mm.sup.2 and a tensile modulus of elasticity of at least 500 Kgf/mm.sup.2 ; and 4) carbonizing the polyimide film in an inert gas or in a vacuum until a carbon film having a tensile strength of at least 15 Kgf/mm.sup.2, a tensile modulus of elasticity of at least 5000 Kgf/mm.sup.2 and an electric conductivity of at least 200 S/cm is formed.

Dependencies are inferred from the claim text.