| 摘要 |
<p>(I) is prepd. by cocondensing isobutylene and formaldehyde in an aq. medium by contact with a carboxylic acid catalyst; splitting the condensn. prods. into organic and aq. phases; evapg. the aq. phase to a bottom residue; mixing this residue with an aq. formaldehyde soln.; and recycling the obtd. mixt. to the condensn. stage. (I) is obtd. with a 3-5% increase in selectivity, compared with the conventional method. Salts of the catalyst are soluble in the organic phase and can be removed with it from the system, dispensing with the problem of corrosion prods. accumulating in the recirculated aq. phase. Also, gum formation is avoided at the evapn. stage. Low-alloyed steels can be used to construct the equipment.</p> |
