| 摘要 |
1332825 Bituminous composition COMPAGNIE FRANCAISE DE RAFFINAGE 17 Dec 1970 [17 Dec 1969] 60051/70 Heading C3N A method for the preparation of hydrocarbon coatings comprises mixing an aggregate of particle size greater than 80Á, a filler of particle size less than 80Á, a hydrocarbon binder and hard asphalts, the aggregate and the hydrocarbon binder being pre-heated, and the hard asphalts being in the form of non pre-heated powder the size of which does not exceed the size of the first part of the aggregate. In a modification the hard asphalts are precipitated round the filler before mixing this latter with the binder and aggregate. The precipitation of the hard asphalts may be effected by adding nhexane to a suspension of the filler in an aromatic solution of asphalts. The hard asphalts are defined as materials rich in asphaltenes of which the proportion of insolubles in carbon disulphide or cyclohexane is not more than 30% by weight and of which the asphaltene content is at least 50% by weight. The hard asphalts may be natural asphalts reduced to powdered form or the insoluble part in n-heptane, n-hexane or light petroleum of a propane.deasphaltation tar, a vacuum distillation residue, an atmospheric distillation residue of crude petroleum, or a bituminous oxide. The hydrocarbon binder is derived from coal or petroleum and may be bitumen. The filler may be sand, gravel, limestone, slag, lime, vulcanized rubber, or filler coke whilst the aggregate may be sand. |
