To provide a manufacturing method of substantially pure methacrylic acid containing at least 99 wt% of methacrylic acid, at most 0.05 wt% of water and other impurities in a constant and reduced amount compared with methacrylic acid of other grades.
A process for manufacturing in a high yield high purity methacrylic acid (HPMAA) which is substantially pure, particularly that which has a purity of at least 99% and a water content of at most 0.05% and contains a minor amount of other impurities including HIBA (2-hydroxyisobutyric acid), acrylic acid, MOMPA (3-methacryloyloxy-2-methylpropionic acid), methacrolein and the like is provided. The improved process comprises feeding a crude methacrylic acid stream and purifying the crude MAA stream in a series of successive distillation steps including two distillation columns. The process permits the manufacture of a high purity methacrylic acid product particularly suitable for the manufacture of a specialty MAA polymer.
ELDER JAMES EDWARD
JOHN JULIETTE JAMIE JERRICK
Hisashi Tsuji
Koji Hashimoto