摘要 |
<p>A naphtha fraction boiling at 93-260 degrees C obtained by cracking in the pressure of up to 95 mol. % steam at 593-845 degrees C is distilled to separate a bottom fraction boiling at 210 degrees C and a top fraction boiling at 210 degrees C. The top fraction is further distilled to give a bottom fraction boiling at 143-210 degrees C and a top fraction boiling at 143 degrees C, this top fraction being further distilled to give a top fraction containing C5 and C6 hydrocarbons and a bottom fraction containing C7 hydrocarbons. The second bottom fraction boiling at 171-210 degrees C and a top fraction boiling at 143-171 degrees C. The resulting fractions are then separately polymerised using Friedel Crafts catalysts to give colourless resins of high softening point.</p> |