Method for tagging petroleum products
US5525516A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1994 |
| Grant date | Jun 11, 1996 |
| Priority date | — |
| Expiry date | Sep 30, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/13
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention provides a method for imparting invisible markings for identification purposes to petroleum hydrocarbons by incorporating one or more infrared fluorescing compounds therein. Certain infrared fluorophores from the classes of squaraines (derived from squaric acid), phthalocyanines and naphthalocyanines are useful in providing invisibly marked petroleum hydrocarbons such as crude oil, lubricating oils, waxes, gas oil (furnace oil), diesel oil, kerosene and in particular gasoline. The near infrared fluorophores are added to the hydrocarbons at extremely low levels and are detected by exposing the marked hydrocarbon compositions to near infrared radiation having a wavelength in the 670-850 nm range and then detecting the emitted fluorescent light via near infrared light detection means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.