GB915445A - Improvements in methods of forming solutions of elastomers and of preparing plastic bitumens - Google Patents

Abstract

A homogeneous solution of an elastomer is formed by using as the solvent, a heavy fraction of a cracking residue of petroleum hydrocarbons, the fraction distilling between 150 DEG and 300 DEG C. at a reduced pressure of 0,1 mm. of mercury. The solution may be concentrated and then incorporated in bitumen which has been heated to a liquid state. Specified elastomers are natural rubber, and butyl rubbers.ALSO:Plastic bitumens are prepared by incorporating in ordinary bitumens a homogeneous solution of natural or synthetic rubber in a heavy fraction of a cracking residue of petroleum hydrocarbons, the fraction distilling between 150 DEG and 300 DEG C., at a reduced pressure of 0,1mm. of mercury. The bitumen may be melted and the solution, preferably a concentrated one, then added. The bitumens may be obtained from petroleums of various origins and may be blown. The amount of rubber solution incorporated may be as high as 40% of the final mixture but is preferably between 10 and 30%. In examples (1) 70 parts of Venezuelan bitumen 80/100 incorporate 30 parts of butyl rubber solution at 20 DEG C. and (2) and (3) 80 parts of blown Venezuelan bitumen incorporate (2) 20 parts of a 20% recovered rubber solution and (3) 20% of a 20% synthetic rubber solution.