Unblown ethylene-vinyl acetate copolymer treated asphalt and its method of preparation
US6136898A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 15, 1999 |
| Grant date | Oct 24, 2000 |
| Priority date | — |
| Expiry date | Jun 15, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L31/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method is provided for improving high temperature performance grade properties of unblown asphalt by i) heating an asphalt cement to 200.degree. F. to 500.degree. F. (93.degree. C. to 260.degree. C.), ii) adding 0.1 wt. % to 10 wt. % ethylene-vinyl acetate copolymer based on weight of said asphalt cement to the heated asphalt cement, iii) adding 0.05 wt. % to 1.0 wt. % phosphorus-containing acid, e.g., polyphosphoric acid, based on weight of said asphalt cement and iv) mixing the resulting blend, thereby providing an unblown asphalt composition of greater useful temperature index (UTI). The invention further relates to asphalt compositions thus made and paving compositions containing these asphalt compositions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.