To obtain an acrylonitrile-based polymer which exhibits, when made into a carbon fiber, a high strength and modulus of elasticity, and also to pro vide a precursor fiber for carbon fiber using the same.
This acrylonitrile-based polymer, serving as a stock for precursor fibers for carbon fibers, is produced under the polymerization conditions to give 3 types of polymers having copolymerization extents M of (1) 0.5±0.2, (2) 1.5±0.2 and (3) 2.5±0.2, respectively, and slope (dV/dM) in the V-M curve of 0.1 or more for each polymer having the above compositional range, wherein M (mol%) is copolymerization extent of a monomer unit having carboxylate group, V (min-1) is reciprocal of time before an exothermic peak appears in an isothermal exothermic curve, measured by differential scanning colorimetry effected at 230°C in a flow of air, and the slope is determined by the least square method.
KAKITA HIDETO
HOSAKO YOSHIHIKO
YAMADA TERUYUKI
| JPH05320266A | 1993-12-03 |
Next Patent: N-ISOPROPYL(METH)ACRYLAMIDE POLYMER AND ITS PRODUCTION