| abstract |
PROBLEM TO BE SOLVED: To provide a polymerization inhibitor which is effective for preventing polymerization of a vinyl monomer and does not discolor the product during distillation. SOLUTION: General formula (I) Wherein n represents 1 or 2, and when n is 1, R is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, and n is In the case of 2, R represents an alkylene group having 1 to 10 carbon atoms, etc.], a vinyl monomer polymerization inhibitor containing an N-oxyl compound represented by the formula: |