Process for preparing rubber-modified asphalt compositions
US5683498A · kind A · utility
Inventor
Key dates
| Filing date | Jun 12, 1996 |
| Grant date | Nov 4, 1997 |
| Priority date | — |
| Expiry date | Jun 12, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L95/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A modified asphalt composition having improved low-temperature fracture properties is obtained by devulcanizing crumb rubber, preferably ground rubber tire. The devulcanization is effected without the use of harsh oxidizing treatments or the addition of potentially hazardous solvents, by fractional distillation of a mixture of the rubber and crude oil to a temperature at which substantially complete devulcanization occurs and harmful volatiles are driven off, around 300.degree. C. The resulting compositions are relatively inexpensive and simple to produce and, not having been oxidized, may be expected to show better long-term aging and fatigue performance compared to air-blown asphalts and the like. They are also preferable, on grounds of health and safety, to prior paving asphalts containing significant proportions of volatile organic aliphatic or aromatic hydrocarbons.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.