| 摘要 |
PURPOSE:In preparing the titled compound by reacting acrylic acid, etc. with an alkylene oxide in the presence of a catalyst, to prevent polymerization, etc. and to improve yield, by carrying out the reaction in such a way that wavelength to show the maximum absorbance at >=500nm in visible light absorption in made >= a specific wavelength. CONSTITUTION:(Meth)acrylic acid of raw material is reacted with an alkylene oxide by the use of a trivalent chromium compound as a catalyst at 60-120 deg.C, preferably at 70-100 deg.C. Absorption spectrum of the reaction solution is measred. When the reaction is completely finished, a wavelength (lambdamax) to show maximum absorbance of absorption spectrum is 570-575nm, but it is 580-600nm at the beginning of the reaction. The reaction is carried out in such a way that lambdamax is a wavelength >=575nm, the reaction is finished before it becomes 575nm, and the reaction solution is distilled to give the titled compound. An amount of the catalyst used is preferably 0.1-1.0wt% based on (meth)acrylic acid. |
