Patent ID: 7338997

Claim:
A process for production of a carbon fiber precursor polymer which yields a carbon fiber precursor polymer composed of a polymer comprising 50 wt % or greater of an acrylonitrile component, wherein the isotactic triad proportion of the acrylonitrile structural chain composed of the acrylonitrile component is 35 mole percent or greater based on the total triad proportion of the acrylonitrile structural chain composed of the acrylonitrile component, by using an unsaturated copolymerizing component composed mainly of acrylonitrile as a template compound, absorbing it into a crystalline metal compound to form a complex, wherein said crystalline metal compound is a hexagonal and/or trigonal metal compound and has a layer structure of at least one compound selected from the group consisting of cadmium iodide, cadmium chloride and cadmium sulfide, and subjecting the complex to solid-phase polymerization reaction for high molecularization.