| 摘要 |
<p>Potassium parahydroxybenzoate production Title cpd. is made by reacting K phenolates, phenol and CO2 in an inert liquid medium which is compatible with the phenol but not with the phenolate. Pref. a mixt. of KOH, phenol and inert medium (e.g. xylene, trimethyl benzene, alpha- and beta-methylnaphthalene, diphenylnaphthalene and diphenyl deriv. diphenyl ether and halogenated aromatic cpds. such as polychlorodiphenyl) is distilled in a column to dehydrate the single phase., which is then reacted with CO2 at 220-250 degrees C/2-20 atm. Water is added to dissolve the product and the oil phase contg. the phenol is recirculated to form more starting soln. Process gives high yields (>60%) of pure product (99%). The title cpd. is used in the prodn of film forming polymers.</p> |
