GB743886A - Improvements in or relating to process for preparing petroleum resins - Google Patents

Abstract

Resinous polymers are produced by maintaining a steam-cracked petroleum fraction, boiling from 20 DEG to 170 DEG C., at a temperature between 40 DEG and 140 DEG C. for a time sufficient to dimerise C5 to C9 cyclic diolefines, such as cyclopentadiene and methyl cyclopentadiene, separating the dimers, and polymerizing the remainder in the presence of a Friedel-Crafts catalyst at a temperature between -50 DEG and 70 DEG C. The fractions may be obtained from naphtha and gas oil cracked at 538 DEG to 815 DEG C. at relatively low pressures in the presence of steam, and contain olefines and diolefines in the C5 to C14 range. The dimers are separated by fractional distillation and the steam-cracked fraction is ten fractionated to remove at least half of the isoprene-containing fraction, boiling below 38 DEG C. The resin is of vacuum stripped to free it from monomers. The polymerization process may be carried out batchwise or continuously in the liquid phase using a fixed bed catalyst or with a fluidized catalyst dissolved or slurried in a solvent and added batchwise or continuously. Examples describe with flow diagrams the use of gaseous boron fluoride, of aluminium chloride as a solid, in ethyl chloride solution or n-hexane slurry, and aluminium bromide in n-hexane as catalysts at various temperatures and concentrations and their removal from the resins by methods such as methyl alcohol precipitation, filtration and washing with alcohol, caustic solution and water.