Patent ID: 6740528
Filing Date: 2004-05-25
Classification: G01R,Y10T

Abstract:
A method for measuring the concentration of piperidine-1-oxyl compound by electron spin resonance method in a process of producing, purifying, storing and/or transporting a radical-polymerizable compound employing the piperidine-1-oxyl stable free radical compound, comprising:a) providing a continuous system including an apparatus for producing or purifying the radical-polymerizable compound employing the piperidine-1-oxyl stable free radical compound in said apparatus; b) connecting said apparatus to a three-way valve which is connected to a fluid by-pass line of said continuous system; c) collecting, continuously or periodically, a sample from said process by said three-way electromagnetic valve; and d) transferring the sample to a measuring cell in a small-sized electron spin resonance measuring apparatus with a permanent magnet.