Acrylic or methacrylic esters - by continuous esterification of acrylic or methacrylic acid with methanol or ethanol
摘要
<p>Continuous prepn. of acrylic or methacrylic acid esters comprises (A) reacting the acid with methanol or ethanol in a molar ratio 1:1.2-5.0 in the liquid phase in the presence of an acid catalyst (e.g. an acidic ion-exchange resin) at 40-100 degrees C (pref. 50-90 degrees C) (B) heating the prod. in an evaporating still to distil off theacrylic or methacrylic acid ester, water and alcohol, the conc. of the acrylic or methacrylic acid of the bottom liquid in the still being kept at 10-40 wt.% and (C) recycling the bottom liquid from the still to the reaction zone in an amt. >=0.4 time the total wt. of acrylic or methacrylic acid and alcohol fed to the reaction zone.</p>
