Tokai Carbon Co. Ltd. (TYO:5301) has posted its full-year business results for 2021, revealing a significant improvement from the previous year. Company-wide sales reached 258.87 billion yen ($2.24 billion), up 28.4 percent year-on-year; operating income was 24.65 billion yen, up 213.6 percent; ordinary income was 24.77 billion yen, up 295.5 percent; and net income was 16.11 billion yen, up from…