Preparation and structure of mesophase pitch-based thin carbon tape

A mesophase pitch of 100 vol % anisotropy prepared from methylnaphthalene using HF/BF₃ was spun through a slit-shaped nozzle, stabilized in air under strain and carbonized at 1300°C into a very thin slit-shaped carbon tape 1.6 μm thick and 14 μm wide. Better crystalline orientation of the carbon tape always provided a Bacon anisotropic factor higher by 2% than that of the circular carbon fibre prepared from the same pitch. Excellent mechanical properties of the present carbon tape were obtained. Factors influencing the shape and orientation of the carbon tape were examined in terms of properties of mesophase pitches, spinning temperature, and the extent and strain of stabilization.