POLYACRYLONITRILE-BASED POLYMER, PROCESS FOR PRODUCTION THEREOF, POLYACRYLONITRILE-BASED POLYMER SOLUTION, PROCESS FOR PRODUCTION OF PRECURSOR FIBER FOR CARBON FIBER, AND PROCESS FOR PRODUCTION OF CARBON FIBER

摘要

Disclosed is a polyacrylonitrile polymer which comprises a component (A) a average molecular weight (M_w) of which as measured by a GPC method is 1,000,000 to 15,000,000 and component (B) based on polyacrylonitrile, a average molecular weight (M_w) of which is between 150000 to 10,000,000, wherein the ratio between average molecular weights of component (A) and (B) is in the range from 2 to 45, and, in addition to that ratio of the component (A)/component (B) (mass ratio)=0.001-0.3, wherein the polymer satisfies the following requirement: Z-average molecular weight (M_z) as measured by a GPC method is between 800000 to 6000000 and the degree of polydispersion (M_z/M_w) (M_w is average molecular weight) is 3.0 to 10.0. The invention also relates to a process for production of such polymer, solution of such polymer, a process for production of precursor fiber for carbon fiber and a process for production of carbon fiber.